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Background : Around 20% - 30% of depressed individuals experience a chronic form of depression lasting two or more years. This naturalistic study investigates the characteristics and the course of chronic depressed patients (CD) during standard antidepressant treatment in comparison to not chronically depressed (NCD) patients. Methods : Data of 954 patients were drawn from the prospective naturalistic, multicenter study of the German research network on depression, CD was met as classifier by 113 patients (11.8%), whereas 841 patients (88.2%) had non-chronic courses (NCD). Results : CD was significantly associated with a low age at onset, use of benzodiazepines, psychotherapy at baseline, substance abuse, a depressive personality disorder and a low degree of extraversion. CD patients showed a longer hospital stay, lower remission rates, increased rates of suicidal ideation as well as higher depression scores at discharge. In addition, individuals with chronic depression continued to obtain higher neuroticism scores and lower extraversion scores at discharge. Limitation : Results were assessed by a post-hoc analysis, based on prospectively collected data. Conclusion : CD patients have an inferior outcome in clinical measures as well as personality dimensions (i.e. low extraversion) compared to non-CD patients. These findings support the notion that CD patients entering a setting of standard psychiatric inpatient care will show less benefit compared to non-CD patients, and that this difference as such may be used as a stratifying marker for providing specialized psychiatric treatment with optimized pharmacological and psychotherapeutic protocols.

Highlights • Elongated fault structures are conduits for focused fluid flow. • Gas migration occurs only along a sub-set of faults across Opouawe bank. • Stress state deduced from 3D fault structures appears partially stratigraphically controlled. Abstract High-resolution 2D and 3D seismic data from Opouawe Bank, an accretionary ridge on the Hikurangi subduction margin off New Zealand, show evidence for exceptional gas migration pathways linked to the stress regime of the ridge. Although the ridge has formed by thrusting and folding in response to a sub-horizontal principal compressive stress (σ1), it is clear that local stress conditions related to uplift and extension around the apex of folding (i.e. sub-vertical σ1) are controlling shallow fluid flow. The most conspicuous structural features are parallel and horizontally-elongated extensional fractures that are perpendicular to the ridge axis. At shallower depth near the seafloor, extensional fractures evolve into more concentric structures which ultimately reach the seafloor where they terminate at gas seeps. In addition to the ridge-perpendicular extensional fractures, we also observe both ridge-perpendicular and ridge-parallel normal faults. This indicates that both longitudinal- and ridge-perpendicular extension have occurred in the past. The deepest stratigraphic unit that we image has undergone significant folding and is affected by both sets of normal faults. Shallower stratigraphic units are less deformed and only host the ridge-parallel normal faults, indicating that longitudinal extension was limited to an older phase of ridge evolution. Present-day gas migration has exploited the fabric from longitudinal extension at depth. As the gas ascends to shallower units it ‘self-generates’ its flow pathways through the more concentric structures near the seafloor. This shows that gas migration can evolve from being dependent on inherited tectonic structures at depth, to becoming self-propagating closer to the seafloor.

High-resolution marine seismic data acquisition and subsequent analyses are highly influenced by sea conditions, directly affecting data quality and interpretation. Traditional swell effect correction methods are effective in improving reflector continuity; however, they are less useful for enhancing travel time consistency at intersection points of crossing lines. To develop a robust swell-removal technique for a set of crossing lines multi-beam echo sounder (MBES) data and Chirp sub-bottom profiler (SBP) data were acquired. After generation of a time structure map of the sea-bottom converted from the final processed multi-beam data, a moving average was used to improve the event continuity of the sea-bottom reflection of the Chirp SBP data. Using the position of the Chirp SBP data, the difference between the travel time of the sea-bottom from the smoothed map and the original travel time of the sea-bottom is calculated as a static correction. The static correction method based on the MBES data was compared and verified using three different cases: (i) simple 2D swell effect correction on a line-by-line basis, (ii) comparing the swell corrections at the crossing positions of 2D lines acquired from different dates, and (iii) comparison of ties of intersection points between 2D lines after new swell correction applied. Although a simple 2D swell correction showed great enhancement of reflector continuity, only the full static correction using the newly proposed method using MBES data produced completely corrected reflection events especially at the crossing points of 2D lines.

Highlights • Dual-vergence structure is observed for the first time on the northern Cascadia margin. • Around central Vancouver Island, vergence switches from seaward in the south to landward in the north. • First OBS migration study imaging the top of the igneous oceanic crust using only a small airgun source (120 in.3). • OBS migration indicates that an OBS, in water depths up to 2.5 km, can image up to 5 km on either side of its seafloor position. Abstract The detailed structure of the northern Cascadia basin and frontal ridge region was obtained using data from several widely spaced ocean bottom seismometers (OBSs). Mirror imaging was used in which the downgoing multiples (mirror signal) are migrated as they provide information about a much larger area than imaging with primary signal alone. Specifically, Kirchhoff time migration was applied to hydrophone and vertical geophone data. Our results indicate remarkable structures that were not observed on the northern Cascadia margin in previous single-channel or multi-channel seismic (MCS) data. Results show that, in these water depths (2.0–2.5 km), an OBS can image up to 5 km on either side of its position on the seafloor and hence an OBS spacing of 5 km is sufficient to provide a two-fold migration stack. Results also show the top of the igneous oceanic crust at 5–6 km beneath the seafloor using only a small airgun source (120 in.3). Specifically, OBS migration results clearly show the continuity of reflectors which enabled the identification of frontal thrusts and a main thrust fault. These faults indicate, for the first time on this margin, the presence of a dual-vergence structure. These kinds of structures have so far been observed in < 0.5% of modern convergent margins and could be related to horizontal compression associated with subduction and low basal shear stress resulting from over-pressure. Reanalysis of previous MCS data from this region augmented the OBS migration results and further suggests that the vergence switches from seaward to landward around central Vancouver Island. Furthermore, fault geometry analyses indicate that the total amount of shortening accommodated due to faulting and folding is about 3 km, which suggest that thrusting would have started at least ∼ 65 ky ago.

Highlights • Multiple submarine landslide scars occur on the Beaufort Continental Slope. • Scars are left by large-scale Late Holocene retrogressive slope failures. • Scars coalesce downslope to form basin wide feature at ≥1200 m depths. • Failure planes are at 30–75 depths within rapidly deposited glaciomarine sediments. • Widespread brackish water infusion into failure zone preconditions slope for failure. Exploration of the continental slope of the Canadian Beaufort Sea has revealed a remarkable coalescence of slide scars with headwalls between 130 and 1100 m water depth (mwd). With increased depth, the scars widen and merge into one gigantic regional slide scar that is more than 100 km wide below ~1100 mwd. To understand the development of these features, five sites were investigated with an Autonomous Underwater Vehicle, which provided 1-m bathymetric grids and Chirp profiles, and surveyed with a Remotely Operated Vehicle. The morphologies are consistent with retrograde failures that occurred on failure planes located between 30 and 75 m below the modern seafloor. At issue is whether the continental slope in this area is preconditioned for failure. While rapid sedimentation during glacial periods, and the presence of shallow gas cannot be ruled out, given the geological environment, it is unclear that they are primary preconditioning factors. Evidence of widespread flushing of the slope with brackish waters, and observed flows of brackish water within slide scars, suggest fluid venting and overpressure may play a role in the development of the extensive slope failures seen along this margin. The impact of pore water salinity changes at the depth of the failure plane on slope stability has not been considered in marine settings previously.

Summary Genome editing in induced pluripotent stem cells is currently hampered by the laborious and expensive nature of identifying homology-directed repair (HDR)-modified cells. We present an approach where isolation of cells bearing a selectable, HDR-mediated editing event at one locus enriches for HDR-mediated edits at additional loci. This strategy, called co-targeting with selection, improves the probability of isolating cells bearing HDR-mediated variants and accelerates the production of disease models., Graphical Abstract, Highlights • Increases the efficiency of genome editing in human iPSCs • Enhances detectability of variants of interest derived by homology-directed repair • Is a simple, scalable, and adaptable strategy for knocking in variants of interest, The potential of CRISPR/Cas9-based genome editing in iPSCs is currently hampered by the laborious nature of identifying cells modified by the lesser-used homology-directed repair (HDR) pathway. Geurts, McDermott-Roe, and colleagues present a straightforward approach, co-targeting with selection, based on co-modification that enriches for cells undergoing HDR thereby improving targeting efficiencies.

The presence of a wedge of offshore permafrost on the shelf of the Canadian Beaufort Sea has been previously recognized and the consequence of a prolonged occurrence of such permafrost is the possibility of an underlying gas hydrate regime. We present the first evidence for wide-spread occurrences of gas hydrates across the shelf in water depths of 60–100 m using 3D and 2D multichannel seismic (MCS) data. A reflection with a polarity opposite to the seafloor was identified ∼1000 m below the seafloor that mimics some of the bottom-simulating reflections (BSRs) in marine gas hydrate regimes. However, the reflection is not truly bottom-simulating, as its depth is controlled by offshore permafrost. The depth of the reflection decreases with increasing water depth, as predicted from thermal modeling of the late Wisconsin transgression. The reflection crosscuts strata and defines a zone of enhanced reflectivity beneath it, which originates from free gas accumulated at the phase boundary over time as permafrost and associated gas hydrate stability zones thin in response to the transgression. The wide-spread gas hydrate occurrence beneath permafrost has implications on the region including drilling hazards associated with the presence of free gas, possible overpressure, lateral migration of fluids and expulsion at the seafloor. In contrast to the permafrost-associated gas hydrates, a deep-water marine BSR was also identified on MCS profiles. The MCS data show a polarity-reversed seismic reflection associated with a low-velocity zone beneath it. The seismic data coverage in the southern Beaufort Sea shows that the deep-water marine BSR is not uniformly present across the entire region. The regional discrepancy of the BSR occurrence between the US Alaska portion and the Mackenzie Delta region may be a result of high sedimentation rates expected for the central Mackenzie delta and high abundance of mass-transport deposits that prohibit gas to accumulate within and beneath the gas hydrate stability zone.

A pseudo 3-D Chirp sub-bottom profiler (SBP) survey was conducted to define the extension of a fault that was previously identified on low-resolution 2-D seismic data with an emphasis on the shallow sedimentary layers and to determine if the fault extends to the seafloor. The geophysical survey was conducted as part of an environmental impact assessment for a proposed gas hydrate production test in the Ulleung Basin, East Sea. The Chirp SBP raw data were acquired over an area of 1 km × 1 km with an average line spacing of 20 m. To produce a 3-D Chirp SBP volume, we developed an optimal processing sequence that was divided into two steps. The first phase of 2-D data processing included a sweep signature estimation, correlation, deconvolution, swell effect correction, and migration. The second phase of 3-D data processing was composed of a bin design, bin gathering of the final processed 2-D data set, amplitude normalization, and residual statics correction. The 3-D Chirp SBP volume provides enhanced imaging especially due to the residual static processing using a moving average method and shows better continuity of the sedimentary layers and consistency of the reflection events than the individual 2-D lines. Deformation of the seafloor as a result of the fault was detected, and the fault offset increases in the deeper sedimentary layers. We also determined that the fault strikes northwest-southeast. However, the shallow sub-seafloor sediments have high porosities and therefore do not exhibit brittle fault-behavior but rather deform continuously due to fault movement.

Highlights • First chronology of post glacial mass transport deposits in Canadian Beaufort Sea. • Chrono-stratigraphy based on 14C dating of foraminifera and shells. • Type-section seismo-stratigraphy from sub-bottom profiler data was established. • Average recurrence rate of 1 failure event per 1000 yrs., but events are clustered. • Highest number of failure events just prior to the Younger Dryas. Abstract Extent and chronology of 24 buried and seabed-exposed mass transport deposits (MTDs) on the continental slope of the Canadian Beaufort Sea were compiled towards a regional geo-hazard assessment of the Beaufort region. A total of 2220 lines of 3.5 kHz sub-bottom profiler (SBP) data (~40,000-line kilometres) covering an area of 9740 km2 were analyzed to allow a new understanding of slope instability in the region. Several sediment cores acquired across the region allow dating of the sediment cover. A regionally representative seismic-stratigraphy (type section, ca. 60 m thick) of the stratified sediments mantling the slope was defined. The MTDs all occur above a marked change in sedimentation style from a deeper-situated slope fan that varies substantially laterally to the above-lying stratified layers that host the MTDs. The type section comprises three sedimentary units bound by two prominent markers. Relative ages for the MTDs were defined by measuring the thickness of sediments overlying each MTD and linking that sediment package to the type section. Two 3-D seismic data volumes across the study region verified interpretations from 2D data by imaging internal deposit character and down-slope continuity of the MTDs. Seismic amplitude and similarity attributes enabled identification of further MTD events, incompletely imaged by the SBP data. A composite chronostratigraphy based on 14C dating of foraminifera and shells was assembled despite the fact that the type section is far thicker than sediment coring limits. Sub-unit thickness varies up- and down-slope such that a selection of cores across the study region enabled its compilation. The marked change in sedimentation style at the base of the type section required substantial extrapolation to date. Simple (quadratic function) age models project that the base of the type section signals the end of the last glacial maximum (Wisconsinan, or marine isotope stage 2 glaciation) and initiation of pro-glacial plume sedimentation (the deglacial), and finally post-glacial (marine) ultimately from the Mackenzie River. The MTD abundance above this contact defines an average theoretical recurrence rate of one MTD per ~1000 yrs.; however, MTDs are clustered temporally with the highest number of events occurring just prior to the onset of the Younger Dryas at around 13 ka BP (cal.).

Highlights • MeBo drilling in Danube fan down to 147 m recovered limnic to marine deposits. • Molecular and stable isotope characterization of light hydrocarbons, CO2, and H2O. • H and O isotopic compositions of pore water reflect paleoclimate variations. • Isotope relations prove microbial carbonate reduction as major methanogenic pathway. • Control of δ2H–CH4 by δ2H–H2O may lead to misinterpretation of methanogenic paths. Abstract We report on the geochemistry of light hydrocarbons and pore water in sediments down to 147 m below seafloor (mbsf), at two sites within the gas hydrate stability field of the Danube deep-sea fan, Black Sea. Sediments were drilled with MARUM-MeBo200 and comprise the transition from limnic to the recent marine stage. Stable C/N ratios (mean 5.1 and 5.6) and δ13C-Corg values (mean −25.8‰ V-PDB) suggest relatively uniform bulk organic matter compositions. In contrast, pore water δ2H and δ18O values varied considerably from approx. −120‰ to −30‰ V-SMOW and from −15‰ to −3‰ V-SMOW, respectively. These data pairs plot close to the ‘Global Meteoric Water Line’ and indicate paleo temperature variations. Depletions of pore water in 2H and 18O below 40 mbsf indicate low temperatures and likely reflect conditions during (the) last glacial period(s). Methane was much more abundant than the only other hydrocarbons found in notable concentrations, ethane and propane ((C1/(C2+C3) ≥20,000). Relatively constant δ13C–CH4 (~−70‰ V-PDB) and δ13C–C2H6 (~−52‰ V-PDB) values with depth indicate that methane and ethane are predominantly of microbial origin and that their formation was not limited by carbon availability. In contrast, δ2H–CH4 values varied in a large range (approx. −310 to −240‰ V-SMOW) with depth and positively correlated with trends observed for δ2H–H2O. Isotope separations (Δδ13C(CH4–CO2), Δδ2H(CH4–H2O)) substantiate that microbial carbonate reduction (CR) is the prevalent methanogenic pathway throughout the sediments irrespective of their geochemical history. Remarkably, in δ13C–CH4 – δ2H–CH4 diagrams widely used, samples characterized by δ2H–CH4 values more negative than approx. −250‰ plot out of the field assigned for pure CR. We conclude that assignments of microbial methanogenic pathways based on classical interpretations of δ13C–CH4 – δ2H–CH4 pairs can lead to misinterpretations, as severe 2H-depletions of methane formed through microbial CR can result from 2H-depletions of the pore water generated during low-temperature climatic periods.

Highlights • Hypocenters within the subducted Explorer plate indicate slab deformation. • The oceanic slab is bending downward toward the northwest. • A complex sequence of focal mechanisms also indicates plate deformation. • Decreased seismic activity in the overriding plate indicates decoupling to the NW. • Deformation and decoupling could limit megathrust rupture propagation. Abstract At the northernmost extent of the Cascadia subduction zone, the Explorer plate subducts at approximately 2 cm/yr, less than half the rate of the Juan de Fuca plate to the south. The boundary between these two plates is known as the Nootka fault zone, which is one of the focuses of the Seafloor Earthquake Array Japan-Canada Cascadia Experiment (SeaJade). During this survey, an 6.4 earthquake occurred on 24 April 2014. This event and the subsequent aftershocks (referred to as the Nootka Sequence) reveal an approximately 40-km-long subducted fault within the Explorer Plate to the north of the Nootka fault zone. We infer that the fault is a subducted conjugate fault because of its nearly identical orientation to those seaward of the subduction front within the Nootka fault zone. The depth distribution and focal mechanisms of the aftershocks indicate significant margin-parallel deformation of the subducting plate. The subduction interface at the Nootka Sequence fault has been deflected downward to the northwest from a depth of approximately 15 – 25 km over a distance of 25 km. We propose two possible scenarios that are modified from previously suggested slab-tear model with induced margin-parallel mantle flow to explain the significant deformation of the young, warm subducting Explorer plate. To the northwest of this change in slab geometry, a lack of seismic activity above the plate interface indicates that the Explorer plate has partially decoupled from the overriding North America plate. We conclude that the geometric variation separating the southern Explorer plate from the north, along with decoupling and a possible intraslab tear, may be a significant combination to resist the propagation of a megathrust rupture across this boundary.

Mutations of HSPB5 (also known as CRYAB or αB-crystallin), a bona fide heat shock protein and molecular chaperone encoded by the HSPB5 (crystallin, alpha B) gene, are linked to various multisystem disorders featuring variable combinations of cataracts, cardiomyopathy, and skeletal myopathy. This study aims at investigating the pathological mechanisms involved in an early onset myofibrillar myopathy manifesting in a child harboring a homozygous recessive mutation in HSPB5, 343delT. To study HSPB5 343delT protein dynamics, we utilize model cell culture systems including induced pluripotent stem cells (iPSCs) derived from the 343delT patient (343delT/343delT) along with isogenic, heterozygous, gene-corrected control cells (WT KI/343delT), and BHK21 cells, a cell line lacking endogenous HSPB5 expression. 343delT/343delT and WT KI/343delT iPSC-derived skeletal myotubes (iSKMs) and cardiomyocytes (iCMs) did not express detectable levels of 343delT protein, contributable to extreme insolubility of the mutant protein. Overexpression of HSPB5 343delT resulted in insoluble mutant protein aggregates and induction of a cellular stress response. Co-expression of 343delT with WT prevented visible aggregation of 343delT and improved its solubility. Additionally, in vitro refolding of 343delT in the presence of WT rescued its solubility. We demonstrate an interaction between WT and 343delT both in vitro and within cells. These data support a loss of function model for the myopathy observed in the patient, as the insoluble mutant would be unavailable to perform normal functions of HSPB5, though additional gain-of-function effects of the mutant protein cannot be excluded. Additionally, our data highlights the solubilization of 343delT by WT, concordant with the recessive inheritance of the disease and absence of symptoms in carrier individuals.

Background After a first episode in schizophrenia guidelines recommend antipsychotic maintenance treatment (MT) for at least 1 year. Recent RCTs on subsequent targeted intermittent treatment (IT) after stepwise drug discontinuation yielded noticeably higher relapse rates than during MT also in first-episode patients. Nevertheless, about 50% of patients remain stable under IT. Given the potential adverse effects of antipsychotics and the preference of many patients to discontinue drugs, valid predictors for the feasibility of IT are urgently needed to support decision making. Methods Based on a one-year RCT phase comparing MT with IT in first-episode patients after 1 year of MT, conducted within the German Research Network on Schizophrenia (GRNS), predictors for deterioration under IT in 19 feasible patients were identified by logistic regression analysis. Results Deterioration occurred in 10 patients (52.6%). Univariate analyses indicated a lower PANSS positive score after acute treatment as well as after one year of MT as significant predictors; in multivariate logistic regression, in addition to the lower PANSS positive score after acute treatment, reaching enduring remission and having had a deterioration both during MT evolved as significant predictors and indicate a higher risk for deterioration. Conclusions Although limited by the small sample size, our findings suggest that patients who show a favorable response and full and enduring symptom remission during antipsychotic treatment, as well as those with marked deterioration despite MT should rather be recommended to remain on treatment because they are at higher risk for symptom re-exacerbation after (stepwise) drug discontinuation.

Highlights • Sediment influence on hydrate dissolution was studied in the field and lab • In the field, CH4(aq) concentrations were at or below theoretical saturation • Dissolution of natural hydrate blanketed by 15 cm thick sediment was measured • This covered hydrate dissolved at a slower rate than nearby exposed hydrates • In the lab, exposed hydrate dissolved faster than covered hydrate Abstract Dissolution rates of naturally occurring gas hydrates vary by orders of magnitude across studies suggesting that environmental factors may influence hydrate dissolution. To determine the role that sediment cover plays in hydrate dissolution, we used a mini-pore fluid array sampler (mPFA) to continuously collect sediment porewater adjacent to a hydrate outcrop and maintain it at in situ pressure for later analysis. This allowed us to measure in situ dissolved hydrocarbon concentrations in the porewater over time without sample loss due to degassing. We deployed the mPFA at a hydrate outcrop at Barkley Canyon on the Cascadia Margin for nine months. This novel approach yielded concentration data that were used to determine the steady-state dissolution rate of the hydrate outcrop and test predictions of the diffusion-control model for dissolution in the field. In the lab, we conducted a series of experiments with artificial hydrate to directly compare dissolution rates between exposed and sediment-covered hydrate. The dissolution rate of the natural hydrate outcrop covered with sediment was 0.06 cm y− 1. The laboratory experiments of sediment-covered hydrate yielded dissolution rates of 0.6 ± 0.5 cm y− 1 (n = 5). In both laboratory and field observations, the dissolution rate of hydrates exposed directly to bulk water (3.9 ± 1.7 cm y− 1 and 3.5 cm y− 1 respectively) was at least an order of magnitude faster than the dissolution rate of sediment covered hydrate. These results are consistent with expectations of diffusion-control and support this model of hydrate dissolution. In nature, sediment may account for the persistence of hydrate in otherwise methane-depleted environments by increasing the diffusive boundary layer and slowing the rate of molecular diffusion via porosity/tortuosity effects. We provide a number of “Lessons Learned” for improving the instrument design and for consideration during future studies.

To assess daytime cognitive performance, sedation and treatment satisfaction in patients with schizophrenia receiving quetiapine extended release (XR) versus quetiapine immediate release (IR).Phase IV prospective, double-blind, crossover study (NCT01213836). Patients (N=66) with stable schizophrenia, treated with XR or IR before study start, were randomised (1:1) to treatment with XR followed by IR, or IR followed by XR, at the dose received before enrolment (400-750mg). After 10-16days on formulation 1, patients switched to formulation 2. Assessments from three post-dose visits (≥5days following treatment on each formulation) were analysed. Cognitive performance was measured by CogState Cognition testing. Sedation, treatment satisfaction and safety were also assessed.65 patients received treatment (69.2% male; mean age 37.8years). Daytime cognitive functioning was similar for both groups; adjusted mean difference in Attentional Composite Score in XR and IR patients was 0.005 (p=0.907). Patients receiving XR were less sedated than those receiving IR, (Bond-Lader visual analogue scale score, mean [SD]: 23.5 [19.0] vs 28.6 [21.4]); estimated overall treatment difference: 5.2 (95% CI: 2.3, 8.2; p0.0009). Patients receiving XR reported feeling less sedated than those on IR (Stanford Sleepiness Scale, mean [SD]: 2.4 [0.9] vs 2.6 [1.0]); estimated overall treatment difference: 0.28 (95% CI: 0.12, 0.43; p0.0008). Patients reported improved overall treatment satisfaction (p=0.0417) and milder side effects (p=0.0035) with XR. Safety profile was similar in both groups.Daytime cognitive performance was similar for both groups. XR was associated with less daytime sedation and improved patient satisfaction than IR.

Gas hydrate resource assessments that indicate enormous global volumes of gas present within hydrate accumulations have been one of the primary driving forces behind the growing interest in gas hydrates. Gas hydrate volumetric estimates in recent years have focused on documenting the geologic parameters in the “gas hydrate petroleum system” that control the occurrence of gas hydrates in nature. The primary goals of this report are to review our present understanding of the geologic controls on the occurrence of gas hydrate in the offshore of India and to document the application of the petroleum system approach to the study of gas hydrates. National Gas Hydrate Program of India executed the National Gas Hydrate Program Expedition 01 (NGHP-01) in 2006 in four areas located on the eastern and western margins of the Indian Peninsula and in the Andaman Sea. These areas have experienced very different tectonic and depositional histories. The peninsular margins are passive continental margins resulting from a series of rifting episodes during the breakup and dispersion of Gondwanaland to form the present Indian Ocean. The Andaman Sea is bounded on its western side by a convergent margin where the Indian plate lithosphere is being subducted beneath southeast Asia. NGHP-01 drilled, logged, and/or cored 15 sites (31 holes) in the Krishna–Godavari Basin, 4 sites (5 holes) in the Mahanadi Basin, 1 site (2 holes) in the Andaman Sea, and 1 site (1 hole) in the Kerala–Konkan Basin. Holes were drilled using standard drilling methods for the purpose of logging-while-drilling and dedicated wireline logging; as well as through the use of a variety of standard coring systems and specialized pressure coring systems. NGHP-01 yielded evidence of gas hydrate from downhole log and core data obtained from all the sites in the Krishna–Godavari Basin, the Mahanadi Basin, and in the Andaman Sea. The site drilled in the Kerala–Konkan Basin during NGHP-01 did not yield any evidence of gas hydrate. Most of the downhole log-inferred gas hydrate and core-recovered gas hydrate were characterized as either fracture-filling in clay-dominated sediments or as pore-filling or grain-displacement particles disseminated in both fine- and coarse-grained sediments. Geochemical analyses of gases obtained from sediment cores recovered during NGHP-01 indicated that the gas in most all of the hydrates in the offshore of India is derived from microbial sources; only one site in the Andaman Sea exhibited limited evidence of a thermogenic gas source. The gas hydrate petroleum system concept has been used to effectively characterize the geologic controls on the occurrence of gas hydrates in the offshore of India.

Shear wave velocity data have been acquired at several marine gas hydrate drilling expeditions, including the India National Gas Hydrate Program Expedition 1 (NGHP-01), the Ocean Drilling Program (ODP) Leg 204, and Integrated Ocean Drilling Program (IODP) Expedition 311 (X311). In this study we use data from these marine drilling expeditions to develop an understanding of general grain-size control on the P- and S-wave properties of sediments. A clear difference in the downhole trends of P-wave (Vp) and S-wave (Vs) velocity and the Vp/Vs ratio from all three marine regions was observed: the northern Cascadia margin (IODP X311) shows the highest P-wave and S-wave velocity values overall and those from the India margin (Expedition NGHP-01) are the lowest. The southern Cascadia margin (ODP Leg 204) appears to have similar low P-wave and S-wave velocity values as seen off India. S-wave velocity values increase relative to the sites off India, but they are not as high as those seen on the northern Cascadia margin. Such regional differences can be explained by the amount of silt/sand (or lack thereof) occurring at these sites, with northern Cascadia being the region of the highest silt/sand occurrences. This grain-size control on P-wave and S-wave velocity and associated mineral composition differences is amplified when compared to the Arctic permafrost environments, where gas hydrate predominantly occurs in sand- and silt-dominated formations. Using a cross-plot of gamma ray values versus the Vp/Vs ratio, we compare the marine gas hydrate occurrences in these regions: offshore eastern India margin, offshore Cascadia margin, the Ignik-Sikumi site in Alaska, and the Mallik 5L-38 site in the Mackenzie Delta. The log-data from the Arctic permafrost regions show a strongly linear Vp–Vs relationship, similar to the previously defined empirical relationships by Greenberg and Castagna (1992). P- and S-wave velocity data from the India margin and ODP Leg 204 deviate strongly from these linear trends, whereas data from IODP X311 plot closer to the trend of the Arctic data sets and previously published relationships. Three new linear relationships for different grain size marine sediment hosts are suggested: a) mud-dominated (Mahanadi Basin, ODP Leg 204 & NGHP-01-17): Vs = 1.5854 × Vp − 2.1649 b) silty-mud (KG Basin): Vs = 0.8105 × Vp − 1.0223 c) silty-sand (IODP X311): Vs = 0.5316 × Vp − 0.4916 We investigate the relationship of gas hydrate saturation determined from electrical resistivity on the Vp/Vs ratio and found that the sand-dominated Arctic hosts show a clearly decreasing trend of Vp/Vs ratio with gas hydrate saturation. Though limited due to lower overall GH saturations, a similar trend is seen for sites from IODP X311 and at the ash-dominated NGHP-01-17 sediment in the Andaman Sea. Gas hydrate that occurs predominantly in fractured clay hosts show a different trend where the Vp/Vs ratio is much higher than at sand-dominated sites and remains constant or increases slightly with increasing gas hydrate saturation. This trend may be the result of anisotropy in fracture-dominated systems, where P- and S-wave velocities appear higher and Archie-based saturations of gas hydrate are overestimated. Gas hydrate concentrations were also estimated in these three marine settings and at Arctic sites using an effective medium model, combining P- and S-wave velocities as equally weighted constraints on the calculation. The effective medium approach generally overestimates S-wave velocity in high-porosity, clay-dominated sediments, but can be accurately used in sand-rich formations.

Gas hydrate was recovered in the Mahanadi Basin along the eastern continental margin of India during the India National Gas Hydrate Program (NGHP) Expedition-01 in 2006. Infrared imaging of recovered core confirmed gas hydrate occurs predominantly in discrete layers. Pore-water chemistry, electrical resistivity and acoustic velocity down-hole logs were used to estimate gas hydrate saturations at three of the sites in the Mahanadi Basin: Sites NGHP-01-08, -09, and -19. Gas hydrate saturation estimated from pore-water chloride concentrations shows values up to ∼10% of the pore space at ∼200 m below seafloor just above the base of the gas hydrate stability zone (BGHSZ). Gas hydrate saturations estimated from electrical resistivity and acoustic velocity logs using standard relations and modeling approaches are comparable to each other and saturations are ∼10–15% of the pore space. Seismic reflection data were also analyzed for the evidence of gas hydrate, and a bottom-simulating reflector (BSR) was imaged along the seismic profiles in the study area. The depth of the BSR is varying from ∼200 m to ∼300 m below seafloor depending on water depth in the Mahanadi Basin. The occurrence of gas hydrate was observed to be associated with deep-water channel and levee complexes (especially at Site NGHP-01-19) based on the regional seismic data. But the cored/logged section at each site lacked any significant sand fraction, which does not allow for higher gas hydrate saturations. As identified from seismic time-slice data, all sites drilled in the Mahanadi Basin are within the steeper slope region of the channel system and any sand bypassed this region. Significant sand deposition would occur further down slope where typical fan-type deposits can be inferred from the seismic data and thus higher accumulations of gas hydrate would be expected.

Wide-spread bottom simulating reflectors (BSRs) are observed along available multichannel seismic profiles covering an area of about 290 km 2 in the Andaman Sea. The seismic data shows that the BSR occurs at places where water depth exceeds 1000 m, and is identified by cross-cutting relationships with the dipping reflectors. The BSR that represents the base of gas hydrate stability field can be used to infer the gas hydrate stability thickness, which ranges between ∼518 m to ∼861 m depending on water depths. In situ measurement at site 17 during the Indian National Gas Hydrate Program (NGHP) Expedition-01 shows very low geothermal gradient 19 ± 2 °C/km. A conductive model was used to determine geothermal gradients from BSRs, which is calculated and varying between 10 °C/km to 40 °C/km. The low geothermal gradient is responsible for the deepest BSR or gas hydrate stability zone (GHSZ) in the Andaman region and in the world. The geothermal modeling shows a close match of the predicted base of the gas hydrate stability zone with the observed BSR depths.

Logging-while-drilling (LWD) and wire-line (WL) velocity data from the second Korean Ulleung Basin Gas Hydrate Drilling Expedition in 2010 (UBGH2) were used to predict gas hydrate saturations using the effective medium theory (EMT) at four representative sites: We used Sites UBGH2-10 and UBGH2-6 where gas hydrate occurs mostly within strata-bound sandy turbidite layers. Sites UBGH2-2_1 and UBGH2-2_2 are used to investigate a typical cold vent setting and fracture-dominated systems. We first use a new technique to correct the LWD velocity data within the shallower portions of the borehole (typically upper 60–100 m below seafloor, mbsf) where the nature of soft sediments often results in erroneous low velocity readings of the LWD tool around values between 1350 m/s and 1400 m/s. Using the Vertical Seismic Profile (VSP) data, a smooth background velocity trend is defined, onto which the LWD data is projected. After this correction, the LWD velocity data of all four sites were used to estimate gas hydrate saturation values using the EMT for a 2-phase mineral-assemblage of 90% clay and 10% quartz only, as well as a detailed mineralogy based on the core XRD data. Both these estimates are then compared to the estimates from the electrical resistivity data using an empirical Archie-analysis. The results from EMT and Archie are on average the same, when gas hydrate occurs as a pore-filling medium within thick sediment layers of homogenous nature, such as that encountered at Site UBGH2-10 where saturations are about 60% of the pore space in an interval of 124–128 mbsf. If gas hydrate occurs in thin sand layers where the thickness of the layer is at or smaller than the vertical resolution of the velocity logging tool, Archie-based results are higher than the EMT-based results due to the higher resolution of the resistivity logging-tool. In cold vent settings with fracture-dominated gas hydrate settings (such as that investigated at Sites UBGH2-2_1 and 2-2_2). Archie-based results are non-reliable and strongly over-estimated due to the anisotropic effect of near-vertical hydrate-filled fractures. In such cold vent settings, velocity-based techniques using the EMT are the preferred method to estimate the gas hydrate saturations. At Site UBGH2-2_1, hydrate saturations are on average 5–10% of the pore-space and even lower at Site UBGH2-2_2 (less than 5% on average).

Authigenic carbonate precipitation occurs within marine sediments where sulfate-dependent anaerobic methane oxidation occurs. Geochemical and isotopic analyses of authigenic carbonates are commonly used as indicators of carbon sources and environmental conditions present during carbonate formation, but burial diagenesis and recrystallization can overprint these signals. Plane polarized light (PPL) and cathodoluminescent (CL) petrography allows for detailed characterization of carbonate phases and their subsequent alteration. Petrographic, isotopic, and geochemical characteristics of modern offshore authigenic carbonates from central and northern Cascadia are compared with Oligocene–Pliocene fossil seep carbonates uplifted on the Olympic Peninsula. Coupled analyses show the value and complexity of separating primary vs. secondary signals with relevance to understanding fluid-burial history in methane seep provinces on tectonically active convergent margins. The modern, offshore, near-seafloor diagenetic environment (S. Hydrate Ridge and Barkley Canyon) is dominated by acicular and microcrystalline aragonite and high-Mg calcite (HMC, > 12 mol % Mg). PPL and CL data illustrate that aragonite and HMC phases recrystallize to intermediate-Mg calcite (IMC, 5–12 mol% Mg) during burial and diagenesis and eventually to low-Mg calcite (LMC

During the Second Gas Hydrate Drilling Expedition in the Ulleung Basin (UBGH2), pore fluids were collected from sites that sampled sediments from the continental slope to the basin center, and included locations within and outside seismic identified chimney like features. At five non-chimney sites established during the UBGH2, discrete excursions to low Cl− concentrations within the gas hydrate occurrence zone (GHOZ) are associated with water enriched in δD and δ18O, as expected from gas hydrate dissociation during core recovery. Estimates of gas hydrate saturation values (Sh) based on Cl− and δD values are in good agreement, and show that when gas hydrate occurs in discrete horizons or within strata-bound fractures throughout the GHOZ, it occupies 5–65% of the pore space. Fluids recovered from three sites characterized by seismic inferred chimneys show massive hydrate accumulation near the seafloor, accompanied by the formation of shallow Cl− rich brines with δD and δ18O values lower than seawater. Chemical and isotopic data from fluids sampled at all drilled sites reveal significant fluid freshening below the gas hydrate stability zone (GHSZ). The distribution of Cl−, K+ and δD indicate that the observed freshening is predominantly caused by clay mineral dehydration (illitization). Previously reported heat flow values in the center of the basin indicate that the sediments deeper than 800 mbsf (meter below seafloor) are warm enough to expect clay diagenesis with the onset of smectite-to-illite transformation. Source fluid temperatures >70 °C are confirmed through the use of Na+–Li+ and Mg2+–Li+ geothermometry. Based on these observations we propose the following scenario for the evolution of formation fluids in the Ulleung Basin where high formation temperatures and rapid sedimentation at the basin center, led to sediment compaction and clay dehydration reactions that result in fluid overpressures and associated fracturing of the formation. Sediment fractures and fluid (possible gas) migration in the chimney features, imaged in seismic records, are consistent with our postulated upward transport of fluids from >800 m depth though the GHSZ and to the seafloor.

During drilling in 2010 in the Ulleung Basin, East Sea, Logging-While-Drilling (LWD) was conducted for thirteen sites. LWD data shows various characteristics indicating presence of gas hydrate-bearing sediments. In particular, a series seismic chimney sites are characterized by anomalous log data (i.e. high resistivity and velocity values), compared to surrounding marine sediments. At chimney sites, the resistivity and velocity log values are over 200 Ω-m and 3000 m/s, respectively. Moreover, log values of low density (less than 1.1 g/cm3) indicating the presence of massive hydrates also correlate with intervals with the highest resistivity and velocity. Gas hydrates at the seismic inferred chimney sites occurred within inclined fractures in the mud dominated sediments. These gas hydrate-filled fractures were identified on LWD resistivity images and X-ray images of pressure cores. The gas hydrate-filled fracture intervals coincide with high measured resistivity intervals at three sites (Sites UBGH2-3, UBGH2-7, UBGH2-11). In most cases, high measured resistivity translated into high hydrate saturations via Archie's relationship; but the high saturations derived from the Archie's relationship appear to overestimate gas hydrate saturations when compared to pressure core samples and acoustic log measurements. Also, in intervals with inclined gas hydrate-filled fractures (e.g., UBGH2-3), there is notable separation between phase-shift and attenuation resistivity logs, with 2 MHz resistivity measurements being significantly higher than 400 kHz resistivity measurements. In this study, the analysis of fractures with dip angles greater than 30° on the resistivity log-images show dip angles between 43 and 63° in average for the three sites examined. The dip azimuth of the fractures at Sites UBGH2-3 and UBGH2-7 dominate westerly to southwestern direction, while the fractures at Site UBGH2-11 are characterized by no preferred orientation. This fracture pattern indicates that maximum horizontal stress direction at the time of fracture formation was not constant. In addition, the differential compaction of the sediments after deposited may be contributed to the development of fracture.

The identification of areas of natural gas hydrate occurrence, defining its concentration and regional distribution, as well as understanding the processes that control gas hydrate formation is a crucial component of regional gas hydrate assessments. In this study, we incorporate an additional element into a regional assessment strategy by including the depositional environment defined through seismic facies classes. The seismic facies classification is attempted using regional 2D seismic data and a 3D seismic volume, as well as core and log-data from two gas hydrate drilling expeditions carried out in the Ulleung Basin, East Sea, to conduct a fully integrated gas hydrate assessment. The facies classification described in this study is part of a procedure to conduct an assessment including: (1) Lithologic description of the recovered core and describe the deposition character of the sediment facies identified; (2) seismic facies classification using 2D and 3D seismic data and their derived various seismic attributes; (3) Linking seismic facies classes to core-derived sedimentological descriptions to define the host-strata most favourable for gas hydrate occurrences; (4) Defining reservoir physical properties and linking these to seismic facies classes for reservoir property description; (5) Calculating regional elements of the gas hydrate petroleum system (top of gas hydrate occurrence and base of gas hydrate stability); (6) Merging seismic facies and reservoir properties, definition of the top and base of the gas hydrate stability zone, to calculate gas hydrate saturations in each seismic facies and the total volume of gas hydrate present in the study area; (7) Defining probabilistic elements of the predicted volume of gas hydrate by combining statistical information of the individual input parameters through exhaustive Monte Carlo simulations. The seismic facies classification algorithm used in this study is based on identifying clusters (classes) that show similar properties in the seismic data and derived attribute characteristics. Our classification scheme uses seven seismic attributes (amplitude, instantaneous frequency and amplitude (also referred to as envelope), sweetness, acoustic impedance, thin-bed- and parallel-bedding indicator) and incorporates the use of principle component analysis for data reduction. The achieved classifications are overall robust and yield identical facies classes for the co-located 2D and 3D data. Linking the seismic facies classes to the recovered core and sedimentological descriptions results in a sedimentological interpretation of the seismic facies. Cross-plots of individual components as well as analysing the Eigen-vectors and -values from the principle component analysis (PCA) helps understand the physical meaning of these seismic facies classes and their seismic character. The five facies classes assigned to the 3D volume and 2D seismic line after PCA represent the mass transport deposit (MTD) units (class #1), hemipelagic mud with some sandy turbidite (class #2), hemipelagic mud with many sandy turbidites (class #3), as well as water-bearing mud with few sand layers and occurring mostly at shallow depth near the seafloor or beneath the base of the gas hydrate stability zone (classes #4 and #5). Within the study area and seismic data sets used, gas hydrate occurrences are only linked to facies classes #2 and #3.

A new strategy to assess occurrences of marine gas hydrate has been implemented for the study area of the Ulleung Basin, East Sea, where two comprehensive gas hydrate drilling programs completed logging and coring at 18 sites. In this study we introduce multi-attribute analyses using five drill sites along a regional 2D seismic line to predict physical properties of P-wave velocity, density, and porosity required for gas hydrate saturation calculations. The five well-sites allow a reasonable cross-validation of the final multi-attribute-based prediction and to derive statistical parameters used in a Monte Carlo simulation of total gas hydrate volume in the study area. A similar analysis was completed for a 3D seismic volume around Site UBGH1-4. The crucial boundaries of the top of gas hydrate occurrence zone (TGHOZ) and base of the gas hydrate stability zone (BGHSZ) that are part of the gas hydrate petroleum system were calculated using constraints on geothermal gradient, pore-fluid salinity, type of hydrocarbon gases present, sedimentation rates, and total organic carbon content based on results from the two drilling expeditions carried out in the Ulleung Basin as well as other regional studies. Gas hydrate saturations were determined following the effective medium theory and using the sedimentological data obtained at the drill sites to define required mineral compositions. Seismic facies classification allowed the definition of occurrence of certain sediment types along the seismic data used in this study, and physical properties from the multi-attribute analyses and mineral compositions were assigned to each facies class. Statistical parameters of mean and standard deviation were estimated for each input parameter (P-wave velocity, bulk density, mineral compositions, grain density, density-porosity, TGHOZ, BGHSZ) in the gas hydrate saturation calculations based on individual uncertainties in the measurements. In the final step, a Monte Carlo simulation is used to calculate the total amount of gas hydrate (in m3) present in the study region for the two example data set of a 2D seismic line and one 3D seismic volume. The Monte Carlo simulation draws on the various statistical distributions of the input parameters and we have implemented 150,000 simulation runs in this study. The final histogram distributions of total volume of gas hydrate (in m3) allow determination of the mean, median, and mode values, as well as the 95% and 5% probability thresholds for gas hydrate volumes being present in the two study regions, though they are not meant as estimates of possible commercial amounts of gas associated with gas hydrates in the Ulleung Basin.

Gas hydrate saturation estimates were obtained from an Archie-analysis of the Logging-While-Drilling(LWD) electrical resistivity logs under consideration of the regional geological framework of sediment deposition in the Ulleung Basin, East Sea, of Korea. Porosity was determined from the LWD bulk density log and core-derived values of grain density. In situ measurements of pore-fluid salinity as well as for-mation temperature define a background trend for pore-fluid resistivity at each drill site. The LWD data were used to define sets of empirical Archie-constants for different depth-intervals of the logged borehole at all sites drilled during the second Ulleung Basin Gas Hydrate Drilling Expedition (UBGH2). A clustering of data with distinctly different trend-lines is evident in the cross-plot of porosity and formation factor for all sites drilled during UBGH2. The reason for the clustering is related to the difference between hemipelagic sediments (mostly covering the top w 100 mbsf) and mass-transport deposits (MTD) and/or the occurrence of biogenic opal. For sites located in the north-eastern portion of the Ulleung Basin a set of individual Archie-parameters for a shallow depth interval (hemipelagic) and a deeper MTD zone was achieved. The deeper zone shows typically higher resistivities for the same range of porosities seen in the upper zone, reflecting a shift in sediment properties. The presence of large amounts of biogenic opal (up to and often over 50% as defined by XRD data) was especially observed at Sites UBGH2-2_1 and UBGH2-2_2 (as well as UBGH1-9 from a previous drilling expedition in 2007). The boundary between these two zones can also easily be identified in gamma-ray logs, which also show unusually low readings in the opal-rich interval. Only by incorporating different Archie-parameters for the different zones a reasonable estimate of gas hydrate saturation was achieved that also matches re- sults from other techniques such as pore- fluid freshening, velocity-based calculations, and pressure-core degassing experiments. Seismically, individual boundaries between zones were determined using a grid of regional 2D seismic data. Zoning from the Archie-analysis for sites in the south-western portion of the Ulleung Basin was also observed, but at these sites it is linked to individually stacked MTDs only and does not reflect a mineralogical occurrence of biogenic opal or hemipelagic sedimentation. The individual MTD events represent differently compacted material often associated with a strong decrease in porosity(and increase in density), warranting a separate set of empirical Archie-parameters.

The Second Ulleung Basin Gas Hydrate Drilling Expedition (UBGH2) recovered various forms of gas-hydrate bearing sediments from 10 drill sites in the lower slope and basin floor of the Ulleung Basin. To characterize the gas-hydrate occurrences and the properties of the host sediments, whole-round core samples were taken from portions of recovered cores determined to be hydrate-bearing based on infrared (IR) scanning. These samples were further characterized by a variety of shipboard experiments such as imaging of the sediments with hand-held IR and visual cameras, measurements of pore water chlorinity within and around IR inferred cold regions in the core and grain-size analysis of pore-water squeeze cakes. Sediment compositions of selected samples were further characterized by X-ray diffraction and scanning electron microscopes during post-cruise analysis. The shipboard and post-cruise analysis results collectively indicate that the recovered gas hydrates mainly occur as 1) “pore-filling” type bounded by discrete silty sand to sandy silt layers, 2) “fracture-filling” veins and nodules, or 3) “disseminated” type in silt. In addition, minor but significant variation in gas hydrate concentrations were observed in diatomaceous silt where gas hydrates occur as “pore-filling” material in layers dominated by intact diatom frustules. Gas hydrate accumulations of “fracture-filling” type occur predominantly in regions where acoustic blanking features in the seismic record suggest gas migration from below the gas hydrate stability zone. Results from the UBGH2 core studies along with the analysis of similar samples from other expeditions, including those executed by the Ocean Drilling Program, the Integrated Ocean Drilling Program, and the First Ulleung Basin Gas Hydrate Drilling Expedition, greatly improved our understanding of lithologic controls on marine gas hydrate occurrences.

Multi-channel seismic reflection and well-log data from the Ulleung Basin, East Sea reveal several seismic signatures indicative of gas-hydrate occurrence in the Ulleung Basin that are associated with vertically and/or laterally stacked mass-transport complexes. The seismic indicators include (a) a bottom simulating reflector (BSR), (b) a seismic chimney, (c) high amplitude reflections within the gas hydrate stability zone (GHSZ), (d) acoustic blanking, (e) enhanced reflections below the BSR, and (f) seafloor gas-escape features. The BSR, associated with enhanced reflections below, is most commonly found over much of the basin indicating a physiochemical boundary of gas hydrates overlying free gas. Seismic chimneys are characterized by velocity pull-up and reduced reflectivity on the seismic sections, which appear to be caused by active migration of fluid gas vertically into the GHSZ. The logging data retrieved from the seismic chimneys showed elevated electrical resistivity (>80 Ohm-m) and P-wave velocity (>2000 m/s), indicating the presence of gas hydrate. Another seismic characteristic observed in gas hydrate bearing sediments is the strong amplitude reflections, defined by the relatively high reflectivity within the GHSZ. Acoustic blanking is likely to be the result of hydrate accumulation in the sediments causing a significant reduction of acoustic impedance contrast between sedimentary layers. Where the upward migrating gas seeps into the deep water column, seafloor pockmarks and mud mounds may be formed. Gas hydrate was recovered from the Ulleung Basin, East Sea in 2010 during the Second Ulleung Basin Gas Hydrate Drilling Expedition (UBGH2) under the Korean National Gas Hydrate Program. Based on the results, gas-fluids migrate into the GHSZ through two distinct pathways: (1) structural conduits which include fault and fracture systems associated with seismic chimneys and (2) stratigraphic conduits associated with inclined turbidite/hemipelagic layers. Two types of gas-hydrate occurrence were identified in the basin: (1) a stratally-bound type (pore filling) within turbidite sand layers and (2) a locally concentrated type (massive, nodule or fracture filling) within upward-growing chimneys associated with near vertical faults. Relatively high concentrations of gas hydrate, however, tend to occur in localized seismic chimneys, rather than in the strata-related features. The successful recovery indicates that the Ulleung Basin provides favorable conditions for gas-hydrate formation.

As a part of Korean National Gas Hydrate Program, the Second Ulleung Basin Gas Hydrate Drilling Expedition (UBGH2) was conducted from 9 July to 30 September, 2010 in the Ulleung Basin, East Sea, offshore Korea using the D/V Fugro Synergy. The UBGH2 was performed to understand the distribution of gas hydrates as required for a resource assessment and to find potential candidate sites suitable for a future offshore production test, especially targeting gas hydrate-bearing sand bodies in the basin. The UBGH2 sites were distributed across most of the basin and were selected to target mainly sand-rich turbidite deposits. The 84-day long expedition consisted of two phases. The first phase included logging-while-drilling/measurements-while-drilling (LWD/MWD) operations at 13 sites. During the second phase, sediment cores were collected from 18 holes at 10 of the 13 LWD/MWD sites. Wireline logging (WL) and vertical seismic profile (VSP) data were also acquired after coring operations at two of these 10 sites. In addition, seafloor visual observation, methane sensing, as well as push-coring and sampling using a Remotely Operated Vehicle (ROV) were conducted during both phases of the expedition. Recovered gas hydrates occurred either as pore-filling medium associated with discrete turbidite sand layers, or as fracture-filling veins and nodules in muddy sediments. Gas analyses indicated that the methane within the sampled gas hydrates is primarily of biogenic origin. This paper provides a summary of the operational and scientific results of the UBGH2 expedition as described in 24 papers that make up this special issue of the Journal of Marine and Petroleum Geology.

Schizophrenia patients have deficits in cognitive control as well as in a number of emotional domains. The antisaccade task is a measure of cognitive control that requires the inhibition of a reflex-like eye movement to a peripheral stimulus. Antisaccade performance has been shown to be modulated by the emotional content of the peripheral stimuli, with emotional stimuli leading to higher error rates than neutral stimuli, reflecting an implicit emotion processing effect. The aim of the present study was to investigate the impact on antisaccade performance of threat-related emotional facial stimuli in schizophrenia patients, first-degree relatives of schizophrenia patients and healthy controls. Fifteen patients, 22 relatives and 26 controls, matched for gender, age and verbal intelligence, carried out an antisaccade task with pictures of faces displaying disgusted, fearful and neutral expressions as peripheral stimuli. We observed higher antisaccade error rates in schizophrenia patients compared to first-degree relatives and controls. Relatives and controls did not differ significantly from each other. Antisaccade error rate was influenced by the emotional nature of the stimuli: participants had higher antisaccade error rates in response to fearful faces compared to neutral and disgusted faces. As this emotional influence on cognitive control did not differ between groups we conclude that implicit processing of emotional faces is intact in patients with schizophrenia and those at risk for the illness.

Several theoretical accounts assume that interference control deficits belong to the core symptoms of adult ADHD. However, findings of increased interference effects in adult ADHD patients compared with healthy adults may be confounded with the simultaneous finding of generally slower responses in the patient group. The current study compared the magnitude of the interference effect in the Stroop task between a group of adults with ADHD and a healthy adult control group in a procedure that accounted for differences in overall response speed by using delta plots. The amount of interference did not differ between patient and control group at comparable reaction time levels. These results challenge the conclusions of the previous studies, in that they indicate that interference control is not impaired in adult ADHD.

Gas hydrate was recovered in the Andaman Sea along the eastern coast of the Andaman Islands during the India National Gas Hydrate Program (NGHP) Expedition-01 at Site NGHP-01-17. Coring confirmed gas hydrate occurs predominantly in discrete volcanic ash layers. Pore water chemistry, electrical resistivity and P-wave velocity logs are used to estimate gas hydrate saturations at Site NGHP-01-17. Gas hydrate saturation estimated from chloride concentrations shows values up to ∼85% of the pore space for distinct ash layers from ∼270 m below seafloor to the base of gas hydrate stability zone (BGHSZ). Gas hydrate saturations estimated from the electrical resistivity and acoustic velocity logs using standard empirical relations and modeling approaches are comparable to each other, but saturations are only ∼20% of the pore space on average. This much lower gas hydrate saturation estimate from the log data is a result of overall reduced resolution of the logging tools relative to the typically 20–30 cm thick hydrate-bearing ash layers. Available 2D multi-channel seismic data were also analyzed and a bottom-simulating reflector (BSR) was imaged along several seismic profiles. The depth of the BSR is more than 600 m along the seismic line crossing Site NGHP-01-17, which makes this one of the deepest BSRs observed worldwide. To understand the unusual depth of the BSR, we mapped its depth and estimated heat flow from the BSR depth using a simple conductive model. BSR-derived heat flow values range from ∼12 to ∼41.5 mW/m2 from the study area and follow the bathymetry trend of dominant North–South ridges and can be explained with the east-ward trending increase in heat-flow toward the current seafloor spreading center. We also modeled the BGHSZ to analyze the linkage between gas hydrate occurrences in the Andaman Sea and its relation to the tectonic activity. Our analysis suggests an extensively variable BGHSZ in the Andaman Sea controlled mainly by overall low geothermal gradients. Consistent local minor variations were observed with lower heat flow values over prominent topographic highs and higher values in valleys/troughs due to focusing and defocusing effects of the topography.

Sulfate-dependent anaerobic oxidation of methane (AOM) is the key sedimentary microbial process limiting methane emissions from marine sediments and methane seeps. In this study, we investigate how the presence of low-organic content sediment influences the capacity and efficiency of AOM at Bullseye vent, a gas hydrate-bearing cold seep offshore of Vancouver Island, Canada. The upper 8 m of sediment contains

Impulsivity characterises various psychiatric disorders, particularly attention-deficit/hyperactivity disorder (ADHD). Evidence shows that ADHD symptoms are associated with dopamine dysfunction and alleviated with methylphenidate, a drug that reduces dopamine transporter availability. ADHD-like symptoms and impulsive traits are continuously distributed across the general population. Here, we aimed to investigate the dopaminergic basis of impulsivity and other ADHD-related traits in healthy individuals by studying the association of these traits with striatal dopamine transporter availability. Single-photon emission computed tomography with [(123)I] FP-CIT was performed on 38 healthy males. Impulsivity was measured using the Barratt Impulsiveness Scale (BIS) and hyperactivity-impulsivity and inattention using the Adult ADHD Self-Report Scale (ASRS). We found that greater dopamine transporter availability was associated with higher BIS impulsivity but not with ADHD-related traits. The association with BIS was significant after accounting for individual differences in age and neuroticism. These results suggest that individual differences in the dopamine system may be a neural correlate of trait impulsivity in healthy individuals.

Most authigenic carbonates previously recovered from the Cascadia slope have 87 Sr/ 86 Sr signatures that reflect shallow precipitation in equilibrium with coeval seawater. There is also evidence for carbonate formation supported by fluids that have been modified by reactions with the incoming Juan de Fuca plate ( 87 Sr/ 86 Sr = 0.7071; Teichert et al., 2005) or with terrigenous turbidites ( 87 Sr/ 86 Sr = 0.70975 to 0.71279; Sample et al., 1993). We report on the strontium isotopic composition of carbonates and fluids from IODP Site U1329 and nearby Barkley Canyon (offshore Vancouver Island), which have strontium isotope ratios as low as 0.70539. Whereas the strontium and oxygen isotopic compositions of carbonates from paleoseeps in the uplifted Coast Range forearc indicate formation in ambient bottom seawater, several samples from the Pysht/Sooke Fm. show a 87 Sr-depleted signal ( 87 Sr/ 86 Sr = 0.70494 and 0.70511) similar to that of the anomalous Site U1329 and Barkley Canyon carbonates. Our data, when analyzed in the context of published elemental and isotopic composition of these carbonates (Joseph et al., 2012), point to two formation mechanisms: 1) shallow precipitation driven by the anaerobic oxidation of methane (AOM) with δ 13 C values as low as − 50‰ and contemporaneous 87 Sr/ 86 Sr seawater ratios, and 2) carbonate precipitation driven by fluids that have circulated through the oceanic crust, which are depleted in 87 Sr. Carbonates formed from the second mechanism precipitate both at depth and at sites of deep-sourced fluid seepage on the seafloor. The 87 Sr-depleted carbonates and pore fluids found at Barkley Canyon represent migration of a deep, exotic fluid similar to that found in high permeability conglomerate layers at 188 mbsf of Site U1329, and which may have fed paleoseeps in the Pysht/Sooke Fm. These exotic fluids likely reflect interaction with the 52–57 Ma igneous Crescent Terrane, which supplies fluids with high calcium, manganese and strontium enriched in the non-radiogenic nucleide. Tectonic compression and dehydration reactions then force these fluids updip, where they pick up the thermogenic hydrocarbons and 13 C-enriched dissolved inorganic carbon that are manifested in fluids and carbonates sampled at Barkley Canyon and at Site U1329. The Crescent Terrane may have sourced cold seeps in this margin since at least the late Oligocene.

Executive dysfunctions (regarding behavioural inhibition, decision making, flexibility or voluntary selection) rank among the core symptoms of attention deficit/hyperactivity disorder. Several studies demonstrated functional variations in patients with ADHD especially during response inhibition and flexibility. However, information about functional correlates of other aspects of executive functions such as voluntary selection processes is limited. A group of thirty adult patients with attention deficit/hyperactivity disorder (ADHD) and 30 healthy controls, matched for age and education, participated in the present study. Electrophysiological responses (event-related potentials, gamma oscillations) and behavioural data were acquired during the voluntary selection between various response alternatives. ADHD patients demonstrated increased responses in the gamma frequency band especially in frontal and fronto-central brain areas during voluntary response selection processes compared to healthy subjects. In addition, the error rate was increased in patients. Given that gamma-band responses have been related to GABAergic and glutamatergic responses these results may indicate accordant dysfunction in patients with ADHD.

Gas hydrate saturations were calculated based on Archie's relation and rock-physics modeling utilizing log measurements of electrical resistivity and P-wave velocity through the gas hydrate stability zone (GHSZ) at two sites in the Krishna Godavari (KG) basin off the East Coast of India. Acoustic impedance inversion was then performed around the well sites for regional extrapolation of the borehole data. Well-log based gas hydrate concentration estimates and core data are in general agreement with the seismic impedance inversion results at the individual well sites. However, the correlation with seismic data and thus the confidence in the extrapolation decreases with distance from the well site. To address the general problem of unknown regional confidence limits in the extrapolation and aid in regional gas hydrate assessment analyses, a new approach is introduced by calculating the running-sum of the seismic similarity attribute across the gas hydrate stability zone. The running-sum of the similarity attribute can be used locally on a 2D seismic line or 3D seismic volume for defining the limit of well-data extrapolation around a given well site. By normalizing the running-sum of the similarity attribute from all available 2D seismic data in the KG basin, a regional map was generated yielding effective confidence limits for extrapolation of well-log data. Such maps of regional confidence limits can be used strategically in basin-wide gas hydrate assessments as they provide a measure of probability to find a given gas hydrate concentration, and may also offer a guide for defining a minimum regional spacing between well-sites to address the overall structural complexity of the basin (which is reflected in the similarity of the seismic data).

Mass-transport-deposits (MTDs) and hemipelagic mud interbedded with sandy turbidites are the main sedimentary facies in the Ulleung Basin, East Sea, offshore Korea. The MTDs show similar seismic reflection characteristics to gas-hydrate-bearing sediments such as regional seismic blanking (absence of internal reflectivity) and a polarity reversed base-reflection identical to the bottom-simulating reflector (BSR). Drilling in 2007 in the Ulleung Basin recovered sediments within the MTDs that exhibit elevated electrical resistivity and P-wave velocity, similar to gas hydrate-bearing sediments. In contrast, hemipelagic mud intercalated with sandy turbidites has much higher porosity and correspondingly lower electrical resistivity and P-wave velocity. At drill-site UBGH1-4 the bottom half of one prominent MTD unit shows two bands of parallel fractures on the resistivity log-images indicating a common dip-azimuth direction of about ∼230° (strike of ∼140°). This strike-direction is perpendicular to the seismically defined flow-path of the MTD to the north-east. At Site UBGH1-14, the log-data suggest two zones with preferred fracture orientations (top: ∼250°, bottom: ∼130°), indicating flow-directions to the north-east for the top zone, and north-west for the bottom zone. The fracture patterns may indicate post-depositional sedimentation that gave rise to a preferred fracturing possibly linked to dewatering pathways. Alternatively, fractures may be related to the formation of pressure-ridges common within MTD units. For the interval of observed MTD units, the resistivity and P-wave velocity log-data yield gas hydrate concentrations up to ∼10% at Site UBGH1-4 and ∼25% at Site UBGH1-14 calculated using traditional isotropic theories such as Archie's law or effective medium modeling. However, accounting for anisotropic effects in the calculation to honor observed fracture patterns, the gas hydrate concentration is overall reduced to less than 5%. In contrast, gas hydrate was recovered at Site UBGH1-4 near the base of gas hydrate stability zone (GHSZ). Log-data predict gas hydrate concentrations of 10–15% over an interval of 25 m above the base of GHSZ. The sediments of this interval are comprised of the hemipelagic mud and interbedded thin sandy turbidites, which did contain pore-filling gas hydrate as identified from pore-water freshening and core infra-red imaging. Seismically, this unit reveals a coherent parallel bedding character but has overall faint reflection amplitude. This gas-hydrate-bearing interval can be best mapped using a combination of regular seismic amplitude and seismic attributes such as Shale indicator, Parallel-bedding indicator, and Thin-bed indicator.

Seismic coherency measures, such as similarity and dip of maximum similarity, were used to characterize mass transport deposits (MTDs) in the Ulleung Basin, East Sea, offshore Korea. Using 2-D and 3-D seismic data several slope failure masses have been identified near drill site UBGH1-4. The MTDs have a distinct seismic character and exhibit physical properties similar to gas hydrate bearing sediment: elevated electrical resistivity and P-wave velocity. Sediments recovered from within the MTDs show a reworked nature with chaotic assemblage of mud-clasts. Additionally, the reflection at the base of MTDs is polarity reversed relative to the seafloor, similarly to the bottom-simulating reflector commonly used to infer the presence of gas hydrates. The MTDs further show regional seismic blanking (absence of internal reflectivity), which is yet another signature often attributed to gas hydrate bearing sediments. At the drill site UBGH1-4, no gas hydrate was recovered in sediment-cores from inside a prominent MTD unit. Instead, pore-filling gas hydrate was recovered only within thin turbidite sand layers near the base of the gas hydrate stability zone. With the analysis of seismic attributes, the seismic character of the prominent MTD (Unit 3) was investigated. The base of the MTD unit exhibits deep grooves interpreted as gliding tracks from either outrunner blocks or large clasts that were dragged along the paleo-seafloor. Similar seismic features were identified on the seafloor although the length of the gliding tracks on the seafloor is much shorter (a few hundred meters to ∼1 km), compared to over 10 km long tracks at the base of the MTD. The seismic coherency attributes allowed to estimate the volume of the failed sediment as well as the direction of the flow of sediment. Tracking the MTD and extrapolating its spatial extent from the 3-D seismic volume to adjacent 2-D seismic profiles, a possible source region of this mass failure was defined ∼50 km upslope of Site UBGH1-4.

In western Canada gas hydrates have been thought to exist primarily in the Cascadia accretionary prism off southern Vancouver Island, British Columbia (BC). We present evidence for the existence of gas hydrate in folds and ridges of the Winona Basin up to 40 km seaward from the foot of the continental slope off northern Vancouver Island. The occurrence of a bottom-simulating reflector (BSR) observed in a number of vintage seismic reflection profiles is strongly correlated to faulted, and folded sedimentary ridges and buried folds. The observed tectonic structures of the Winona Basin are within the rapidly evolving Juan de Fuca – Cascadia – Queen Charlotte triple junction off BC. Re-processing of multi-channel data imaged mildly to strongly deformed sediments; the BSR is confined to sediments with stronger deformation. Changes in the amplitude character of sediment-reflections above and below the depth of the base of gas hydrate stability zone were also used as an indicator for the presence of gas hydrate. Additionally, regional amplitude and frequency reduction below some strong BSR occurrences may indicate free gas accumulations. Gas hydrate formation in the Winona Basin appears strongly constrained to folds and ridges and thus correlated to deeper-routed fluid-advection regimes. Methane production from in situ microbial activities as a source of gas to form gas hydrates, as proposed to be a major contributor for gas hydrates within the accretionary prism to the south, appears to be insufficient to produce the widespread gas hydrate occurrences in the Winona Basin. Potential reasons for the lack of sufficient in situ gas production may be that sedimentation rates are 5–100 times higher than those in the accretionary prism so that available organic carbon moves too quickly through the gas hydrate stability field. The confinement of BSRs to ridges and folds within the Winona Basin results in an areal extent of gas hydrate occurrences that is a factor of five less than what is expected from regional gas hydrate stability field mapping using water-depth (pressure) as the only controlling factor only.

Analytical challenges in obtaining high quality measurements of rare earth elements (REEs) from small pore fluid volumes have limited the application of REEs as deep fluid geochemical tracers. Using a recently developed analytical technique, we analyzed REEs from pore fluids collected from Sites U1325 and U1329, drilled on the northern Cascadia margin during the Integrated Ocean Drilling Program (IODP) Expedition 311, to investigate the REE behavior during diagenesis and their utility as tracers of deep fluid migration. These sites were selected because they represent contrasting settings on an accretionary margin: a ponded basin at the toe of the margin, and the landward Tofino Basin near the shelf's edge. REE concentrations of pore fluid in the methanogenic zone at Sites U1325 and U1329 correlate positively with concentrations of dissolved organic carbon (DOC) and alkalinity. Fractionations across the REE series are driven by preferential complexation of the heavy REEs. Simultaneous enrichment of diagenetic indicators (DOC and alkalinity) and of REEs (in particular the heavy elements Ho to Lu), suggests that the heavy REEs are released during particulate organic carbon (POC) degradation and are subsequently chelated by DOC. REE concentrations are greater at Site U1325, a site where shorter residence times of POC in sulfate-bearing redox zones may enhance REE burial efficiency within sulfidic and methanogenic sediment zones where REE release ensues. Cross-plots of La concentrations versus Cl, Li and Sr delineate a distinct field for the deep fluids (z > 75 mbsf) at Site U1329, and indicate the presence of a fluid not observed at the other sites drilled on the Cascadia margin. Changes in REE patterns, the presence of a positive Eu anomaly, and other available geochemical data for this site suggest a complex hydrology and possible interaction with the igneous Crescent Terrane, located east of the drilled transect.

Objectives The involvement of an immune process in the pathophysiology of major depression disorder (MDD) was substantiated by studies demonstrating elevated levels of proinflammatory cytokines and prostaglandin E 2 (PGE 2 ). Cyclooxygenase-2 (COX-2) inhibitors lead to a reduced production of PGE 2 and have been shown to improve depressive symptoms. We investigated the three immune parameters macrophage migration inhibitory factor (MIF), transforming growth factor-β (TGF-β) and soluble CD14 (sCD14) in a randomized, placebo-controlled trial of the COX-2 inhibitor celecoxib as add-on therapy in patients with MDD treated with reboxetine. Methods Thirty-two patients with depression and 20 healthy controls participated in the study. The patients were treated with reboxetine and celecoxib or placebo. Immune parameters were measured from serum at baseline, after three and five weeks using ELISA. Results Celecoxib as add-on strategy resulted in a significant reduction of Hamilton Depression Scale scores compared to placebo. Depressed patients showed significantly elevated MIF ( p p = 0.006) concentrations at baseline. There was no difference in sCD14-concentrations. There was no difference between the placebo and the celecoxib group and no change over time. Limitations Limitations of the study are the relatively small sample size and lack of functional assessment of HPA axis in parallel. Conclusions MIF is a promising new candidate in the neuro-immune interplay that may link depressive symptoms, altered immune state and HPA-axis dysregulation. Reduced levels of TGF-β replicate previous findings and support the importance of this regulatory cytokine in major depressive disorder.

Supplies of conventional natural gas and oil are declining fast worldwide, and therefore new, unconventional forms of energy resources are needed to meet the ever-increasing demand. Amongst the many different unconventional natural resources are gas hydrates, a solid, ice-like crystalline compound of methane and water formed under specific low temperature and high pressure conditions. Gas hydrates are believed to exist in large quantities worldwide in oceanic regions of continental margins, as well as associated with permafrost regions in the Arctic. Some studies to estimate the global abundance of gas hydrate suggest that the total volume of natural gas locked up in form of gas hydrates may exceed all known conventional natural gas reserves, although large uncertainties exist in these assessments. Gas hydrates have been intensively studied in the last two decades also due to connections between climate forcing (natural and/or anthropogenic) and the potential large volumes of methane trapped in gas hydrate accumulations. The presence of gas hydrate within unconsolidated sediments of the upper few hundred meters below seafloor may also pose a geo-hazard to conventional oil and gas production. Additionally, climate variability and associated changes in pressure-temperature regimes and thus shifts in the gas hydrate stability zone may cause the occurrence of submarine slope failures. Several large-scale national gas hydrate programs exist especially in countries such as Japan, Korea, Taiwan, China, India, and New Zealand, where large demands of energy cannot be met by domestic supplies from natural resources. The past five years have seen several dedicated deep drilling expeditions and other scientific studies conducted throughout Asia and Oceania to understand gas hydrates off India, China, and Korea. This thematic set of publications is dedicated to summarize the most recent findings and results of geo-scientific studies of gas hydrates in the marginal seas and continental margin of the Asia, and Oceania region.

The Gas Hydrate Research and Development Organization (GHDO) of Korea successfully accomplished both coring (hydraulic piston and pressure coring) and logging (logging-while-drilling, LWD, and wireline logging) to investigate the presence of gas hydrate during the first deep drilling expedition in the Ulleung Basin, East Sea of Korea (referred to as UBGH1) in 2007. The LWD data from two sites (UBGH1-9, UBGH1-10) showed elevated electrical resistivity (>80 Ω-m) and P-wave velocity (>2000 m/s) values indicating the presence of gas hydrate. During the coring period, the richest gas hydrate accumulation was discovered at these intervals. Based on log data, the occurrence of gas hydrate is primarily controlled by the presence of fractures. The gas hydrate saturation calculated using Archie’s relation shows greater than 60% (as high as ∼90%) of the pore space, although Archie’s equation typically overestimates gas hydrate saturation in near-vertical fractures. The saturation of gas hydrate is also estimated using the modified Biot-Gassmann theory (BGTL) by Lee and Collett (2006). The saturation values estimated rom BGTL are much lower than those calculated from Archie’s equation. Based on log data, the hydrate-bearing sediment section is approximately 70 m (UBGH1-9) to 130 m (UBGH1-10) in thickness at these two sites. This was further directly confirmed by the recovery of gas hydrate samples and pore water freshening collected from deep drilling core during the expedition. LWD data also strongly support the interpretation of the seismic gas hydrate indicators (e.g., vent or chimney structures and bottom-simulating reflectors), which imply the probability of widespread gas hydrate presence in the Ulleung Basin.

During the Indian National Gas Hydrate Program (NGHP) Expedition 01, a series of well logs were acquired at several sites across the Krishna–Godavari (KG) Basin. Electrical resistivity logs were used for gas hydrate saturation estimates using Archie’s method. The measured in situ pore-water salinity, seafloor temperature and geothermal gradients were used to determine the baseline pore-water resistivity. In the absence of core data, Arp’s law was used to estimate in situ pore-water resistivity. Uncertainties in the Archie’s approach are related to the calibration of Archie coefficient ( a) , cementation factor ( m) and saturation exponent ( n) values. We also have estimated gas hydrate saturation from sonic P-wave velocity logs considering the gas hydrate in-frame effective medium rock-physics model. Uncertainties in the effective medium modeling stem from the choice of mineral assemblage used in the model. In both methods we assume that gas hydrate forms in sediment pore space. Combined observations from these analyses show that gas hydrate saturations are relatively low ( S h = 15–20%, in two zones between 168 and 198 mbsf), Site NGHP-01-05 ( S h = 35–38% in two discrete zone between 70 and 90 mbsf), and Site NGHP-01-07 shows the gas hydrate saturation more than 25% in two zones between 75 and 155 mbsf. A total of 10 drill sites and associated log data, regional occurrences of bottom-simulating reflectors from 2D and 3D seismic data, and thermal modeling of the gas hydrate stability zone, were used to estimate the total amount of gas hydrate within the KG Basin. Average gas hydrate saturations for the entire gas hydrate stability zone (seafloor to base of gas hydrate stability), sediment porosities, and statistically derived extreme values for these parameters were defined from the logs. The total area considered based on the BSR seismic data covers ∼720 km 2 . Using the statistical ranges in all parameters involved in the calculation, the total amount of gas from gas hydrate in the KG Basin study area varies from a minimum of ∼5.7 trillion-cubic feet (TCF) to ∼32.1 TCF.

The HOMER 1 protein plays a crucial role in mediating glutamatergic neurotransmission. It has previously shown to be a candidate gene for etiology and pathophysiology of different psychiatric diseases such as schizophrenia. To identify genes involved in response to antipsychotics, subgroups of animals were treated with haloperidol (1 mg/kg, n = 11) or saline (n = 12) for one week. By analyzing microarray data, we replicated the observed increase of Homer 1 gene expression. Furthermore, we genotyped 267 schizophrenic patients, who were treated monotherapeutically with different antipsychotics within randomized-controlled trials. Psychopathology was measured weekly using the PANSS for a minimum of four and a maximum of twelve weeks. Correlations between PANSS subscale scores at baseline and PANSS improvement scores after four weeks of treatment and genotypes were calculated by using a linear model for all investigated SNP’s. We found an association between two HOMER 1 polymorphisms (rs2290639 and rs4704560) and different PANSS subscales at baseline. Furthermore all seven investigated polymorphisms were found to be associated with therapy response in terms of a significant correlation with different PANSS improvement subscores after four weeks of antipsychotic treatment. Most significant associations have been shown between the rs2290639 HOMER 1 polymorphism and PANSS subscales both at baseline conditions and after four weeks of antipsychotic treatment. This is the first study which shows an association between HOMER 1 polymorphisms and psychopathology data at baseline and therapy response in a clinical sample of schizophrenic patients. Thus, these data might further help in detecting differential therapy response in individuals with schizophrenia.

During the India National Gas Hydrate Program (NGHP) Expedition 01 in 2006 significant sand and gas hydrate were recovered at Site NGHP-01-15 within the Krishna–Godavari Basin, East Coast off India. At the drill site NGHP-01-15, a 5–8 m thick interval was found that is characterized by higher sand content than anywhere else at the site and within the KG Basin. Gas hydrate concentrations were determined to be 20–40% of the pore volume using wire-line electrical resistivity data as well as core-derived pore-fluid freshening trends. The gas hydrate-bearing interval was linked to a prominent seismic reflection observed in the 3D seismic data. This reflection event, mapped for about 1 km2 south of the drill site, is bound by a fault at its northern limit that may act as migration conduit for free gas to enter the gas hydrate stability zone (GHSZ) and subsequently charge the sand-rich layer. On 3D and additional regional 2D seismic data a prominent channel system was imaged mainly by using the seismic instantaneous amplitude attribute. The channel can be clearly identified by changes in the seismic character of the channel fill (sand-rich) and pronounced levees (less sand content than in the fill, but higher than in surrounding mud-dominated sediments). The entire channel sequence (channel fill and levees) has been subsequently covered and back-filled with a more mud-prone sediment sequence. Where the levees intersect the base of the GHSZ, their reflection strengths are significantly increased to 5- to 6-times the surrounding reflection amplitudes. Using the 3D seismic data these high-amplitude reflection edges where linked to the gas hydrate-bearing layer at Site NGHP-01-15. Further south along the channel the same reflection elements representing the levees do not show similarly large reflection amplitudes. However, the channel system is still characterized by several high-amplitude reflection events (a few hundred meters wide and up to ~ 1 km in extent) interpreted as gas hydrate-bearing sand intervals along the length of the channel.

High resolution multi-channel seismic reflection data acquired in the offshore domain of the Krishna–Godavari (KG) Basin, provide seismic indicators of gas hydrate including bottom-simulating reflectors (BSR), and high reflectivity zones below the BSR as an indication of free gas. The recent recovery of gas hydrate by drilling across various sites in the KG Basin, together with the seismic indicators, suggests overall widespread favourable gas hydrate stability conditions. The BSRs provide indirect estimates of geothermal gradients and heat flow. A simple conductive model is used to calculate heat flow from the depth of the BSR. BSR-derived heat flow values range from about 30 to 102 mW/m2 across the KG Basin. We also modeled the base of gas hydrate stability zone (BGHSZ) to analyse the linkage between gas hydrate occurrences in the basin and its relation to the fault systems in the basin. The influence of bottom water temperature, pore water salinity and geothermal gradient variation on gas hydrate stability zone (GHSZ) thickness is analysed in relation to both geological formations and tectonics. Our analysis suggests a highly variable GHSZ in the KG Basin controlled by local variations in the parameters of stability condition and faulting. The BSR-derived heat flow increases towards deeper water depths across the basin. Consistent local variations were also observed with low heat flow values over prominent topographic highs and high heat flow values over the flanks of the topographic highs. This variation may be due to focusing and defocusing effects of the topography. However, local BSR-depths patterns may also be due to dynamic effects, including the displacement of isotherms by thrust-faulting. Additionally, recent mass-wasting events and normal faulting resulted in the BGHSZ being too shallow relative to the predicted model (which assumed equilibrium conditions). Seismic and heat flow constraints from the Krishna-Godavari Basin gas hydrate system. Mar Geol - ResearchGate. Available from: http://www.researchgate.net/publication/223314484_Seismic_and_heat_flow_constraints_from_the_Krishna-Godavari_Basin_gas_hydrate_system._Mar_Geol [accessed Nov 5, 2015].

Objective To investigate the association of early improvement and treatment emergent suicidal ideation in a large sample ( N = 705) of naturalistically treated inpatients with major depressive disorder. Method In line with previous reports early improvement was defined as a 20% HAMD improvement within the first two weeks of antidepressant treatment. Treatment emergent suicidal ideation was defined by a sudden increase from 0 or 1 to at least 3 on HAMD item 3 and from 0.1 to at least 4 on MADR item 10 for suicidal ideation. Early improvers were compared with non-early improvers with respect to the occurrence of treatment emergent suicidality during treatment. Results Early improvers were 3 (MADRS) to 3.4 (HAMD) times less likely to experience new emergence of suicidal ideation during the treatment course than non-improvers. In addition, early improvement was associated with significantly less pessimistic thoughts. Limitations The analysis is based on secondary analysis of prospectively collected data. No controlled study design. Conclusion Early improvement is associated with significantly less treatment emergent suicidal ideation for it may provide rapid symptom relief and reduce hopelessness.

To describe the course of positive and negative symptoms during inpatient treatment and examine remission and response rates under routine clinical care conditions.Two hundred and eighty inpatients with schizophrenia (DSM-IV criteria) were assessed with the Positive and Negative Syndrome Scale (PANSS) at admission and at biweekly intervals until discharge from hospital. Remission was defined according to the symptom-severity component of the consensus criteria (Remission in Schizophrenia Working Group) as a rating of three or less in the relevant PANSS items at discharge, and response as a reduction of at least 20% in the PANSS total score from admission to discharge.The mean duration of inpatient treatment was 54.8 days. Of the total sample, 78.5% achieved the criteria for response and 44.6% those for remission. Mean PANSS total scores decreased from 72.4 at admission to 52.5 at discharge (p0.001). A reduction in PANSS total scores was found from visit to visit, up to week 8. The most pronounced decline was observed within the first two weeks of treatment.Response rates were comparable to those found in efficacy studies, and remission rates were slightly higher. This may be explained by differences in the selection and the treatment of patients. Nevertheless, the findings might indicate that a complex naturalistic treatment approach is beneficial in terms of effectiveness.