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Polychromatic laser light can reduce speckle noise in wavefront-sensing and imaging applications that use direct-detection schemes. To help quantify the achievable reduction in speckle, this paper investigates the accuracy and numerical efficiency of three separate wave-optics methods. Each method simulates the active illumination of extended objects with polychromatic laser light. In turn, this paper uses the Monte Carlo method, the depth-slicing method, and the spectral-slicing method, respectively, to simulate the laser-object interaction. The limitations and sampling requirements of all three methods are discussed. Further, the numerical efficiencies of the methods are compared over a range of conditions. The Monte Carlo method is found to be the most efficient, while spectral slicing is more efficient than depth slicing for well-resolved objects. Finally, Hu's theory is used to quantify method accuracy when possible (i.e., for well-resolved objects). In general, the theory compares favorably to the simulation methods.

As a result of intense pressure to reduce costs in offshore oil and gas operations, there has been a surge in support and use of ruggedized unmanned surface vehicles (USVs or ASVs) for several standard tasks in Exploration and Production (E&P), Inspection, Maintenance and Repair (IMR), and Survey operations. As illustrated in several recent case studies from marine construction, seismic, pipelay, hydrographic, and environmental applications, this technology is no longer in development mode, but has in fact become a key element in the re-tooling of the offshore industry for more efficient and safer operations. This paper addresses and reviews a number of important design considerations for ASVs being used in the offshore oil and gas industry. Applications which will be elaborated will include pipeline route surveys, ROV tracking/touch down monitoring, LBL array box-in and calibrations, as-built geophysical surveys for pipelines, unmanned seismic energy source operations for reservoir monitoring, marine mammal acoustic and visual monitoring, and hydrocarbon leak/seep detection operations. Included in this paper are case study observations and data from projects offshore Europe, Gulf of Mexico, the Mediterranean Sea, and Alaska. These results in several cases will also be presented to provide a clear comparison between standard methods showing the cost savings achieved by use of this technology. In all cases, the decreased project costs were made in parallel with no loss of data quality. In some cases, an improvement in data quality over standard methods was made, along with the decreased operational costs. The use of unmanned surface systems in offshore oil and gas operations has become a proven cost reduction tool. A growing number of contractors and operators are now using this technology with good results. In some cases, operators are now specifying this technology be offered by their contractors in order to reduce costs, with measurable results. The decrease in at-sea man hours has also provided a significant risk reduction aspect.

Toxin-producing cyanobacteria are increasing in rivers and streams globally, leading to growing concerns over their potential impacts on aquatic ecosystems. The present study was designed to culture field-collected Phormidium in the laboratory, identify individual species, conduct chemical analyses to identify cyanotoxins, and conduct toxicity tests to investigate the potential for this genera to impact stream health. Freshwater toxicity tests were conducted with standard US Environmental Protection Agency invertebrate test protocols with culture water used to grow 3 Phormidium strains isolated from the Russian River (CA, USA). Enzyme linked immunosorbent assays were used to measure total anatoxin concentrations. Culture waters from the 3 Phormidium strains were highly toxic to Ceriodaphnia dubia, Hyalella azteca, and Chironomus dilutus. The C. dubia 7-d survival median lethal concentrations were 0.71, 0.49, and 0.56 μg/L anatoxin for Phormidum strains 1, 2, and 3, respectively. The 7-d reproduction inhibitory concentrations, 25% were 0.55, 0.32, and 0.30 μg/L anatoxin for strains 1, 2, and 3, respectively. Chironomus dilutus survival was reduced at concentrations2 μg/L anatoxin by all 3 strains, and the H. azteca 96-h lethal concentrations, 25% were 2.82, 1.26, and 5.30 μg/L for strains 1, 2, and 3, respectively. Additional liquid chromatography-mass spectrometry analyses demonstrated that the likely anatoxin variant in these cultures was dihydro-anatoxin-a. The results suggest that anatoxins produced by Phormidium have the potential to impact stream macroinvertebrates. Environ Toxicol Chem 2018;37:2851-2859. © 2018 SETAC.

The scalability of dual wavelength laser gain competition for the design of beam combinable, high power fiber amplifiers is analyzed by characterizing the nonlinear phase accumulated due to self and cross-phase modulation.

The largest accelerations of glaciers and ice sheets are caused by changes in basal slip. Here we examine glacier speed and rain-induced accelerations using a near-continuous 26-month-long GNSS time series from a large maritime glacier (Tasman Glacier, New Zealand). During periods of high rain-rate we observe short-term increases in 24-hour speeds to up to 15-times background speed. Speeds calculated over 3-hour intervals increase to up to 36-times background speed. Acceleration events correspond with times when bed separation also increases rapidly indicating that the acceleration is associated with the growth of water-filled cavities at the bed. Glacier speeds then decrease prior to the reduction in bed separation, indicating cavity growth, not cavity extent, controls the acceleration. The short-term accelerations are superimposed on longer-term periods of enhanced velocity that persist for days to weeks and decay at similar rates to bed separation estimates and proglacial lake levels. A power-law relationship between observed rain-rate and speed exists at the glacier front and exhibits no apparent upper bound. Overall, we estimate that rain-induced accelerations account for 11–14% of Tasman Glacier's displacement during the observation period. The rain-rate–velocity relationship and the rainfall record since 2001 indicate that rain-induced speed-up events result in interannual variability in glacier displacement of 2%–13%.

Glacier mass balance is more sensitive to warming than cooling, but feedbacks related to the exposure of previously buried firn and ice in very warm years is not generally considered in sensitivity...

Reactive oxygen species (ROS) play prominent roles in numerous biological systems. While classically expressed by neutrophils and macrophages, CD4 T cells also express NADPH oxidase (NOX), the superoxide-generating multisubunit enzyme. Our laboratory recently demonstrated that superoxide-deficient nonobese diabetic (NOD.Ncf1m1J) mice exhibited a delay in type 1 diabetes (T1D) partially due to blunted IFN-γ synthesis by CD4 T cells. For further investigation of the roles of superoxide on CD4 T-cell diabetogenicity, the NOD.BDC-2.5.Ncf1m1J (BDC-2.5.Ncf1m1J) mouse strain was generated, possessing autoreactive CD4 T cells deficient in NOX-derived superoxide. Unlike NOD.Ncf1m1J, stimulated BDC-2.5.Ncf1m1J CD4 T cells and splenocytes displayed elevated synthesis of Th1 cytokines and chemokines. Superoxide-deficient BDC-2.5 mice developed spontaneous T1D, and CD4 T cells were more diabetogenic upon adoptive transfer into NOD.Rag recipients due to a skewing toward impaired Treg suppression. Exogenous superoxide blunted exacerbated Th1 cytokines and proinflammatory chemokines to approximately wild-type levels, concomitant with reduced IL-12Rβ2 signaling and P-STAT4 (Y693) activation. These results highlight the importance of NOX-derived superoxide in curbing autoreactivity due, in part, to control of Treg function and as a redox-dependent checkpoint of effector T-cell responses. Ultimately, our studies reveal the complexities of free radicals in CD4 T-cell responses.

Short-term glacier velocity variations typically occur when a water input is accommodated by an increase in the subglacial water pressure. Although these velocity variations have been well documented on many glaciers, few studies have considered them on glaciers where heavy rain and glacier melt occur year-round. This study investigates the relationship between water inputs and glacier velocity on Franz Josef Glacier, New Zealand. We installed six GNSS stations across the lower glacier during austral summer 2010/11 and one station during summer 2012/13. Glacier velocity remained elevated at all stations for ∼7 days following large rain events. During diurnal melt events, we find velocity variations in the early afternoon (12:00–16:00) at 600 m a.s.l. and in the late evening (20:00–01:00) at 400 m a.s.l. We hypothesize that the late-evening velocity variations occurred as an upstream region of high subglacial water pressures and accelerated ice motion propagated downstream. This mechanism may also explain the increased longitudinal compression and transverse extension across the lower glacier during speed-up events. Our results indicate that the subglacial drainage system likely decreases in efficiency upstream and that the water input variability can still cause short-term velocity variations despite the large year-round water inputs.

The Orion Multi-purpose Crew Vehicle (MPCV) Orion spacecraft will return humans from beyond earth's orbit, including Mars and will be required to land 20,000 pounds of mass safely in the ocean. The parachute system nominally lands under 3 main parachutes, but the system is designed to be fault tolerant and land under 2 main parachutes. During several of the parachute development tests, it was observed that a pendulum, or swinging, motion could develop while the Crew Module (CM) was descending under two parachutes. This pendulum effect had not been previously predicted by modeling. Landing impact analysis showed that the landing loads would double in some places across the spacecraft. The CM structural design limits would be exceeded upon landing if this pendulum motion were to occur. The Orion descent and landing team was faced with potentially millions of dollars in structural modifications and a severe mass increase. A multidisciplinary team was formed to determine root cause, model the pendulum motion, study alternate canopy planforms and assess alternate operational vehicle controls & operations providing mitigation options resulting in a reliability level deemed safe for human spaceflight. The problem and solution is a balance of risk to a known solution versus a chance to improve the landing performance for the next human-rated spacecraft.

The development of high-power fiber lasers is of great interest due to the advantages they offer relative to other laser technologies. Currently, the maximum power from a reportedly single-mode fiber amplifier stands at 10 kW. Though impressive, this power level was achieved at the cost of a large spectral linewidth, making the laser unsuitable for coherent or spectral beam combination techniques required to reach power levels necessary for airborne tactical applications. An effective approach in limiting the SBS effect is to insert an electro-optic phase modulator at the low-power end of a master oscillator power amplifier (MOPA) system. As a result, the optical power is spread among spectral sidebands; thus raising the overall SBS threshold of the amplifier. It is the purpose of this work to present a comprehensive numerical scheme that is based on the extended nonlinear Schrodinger equations that allows for accurate analysis of phase modulated fiber amplifier systems in relation to the group velocity dispersion and Kerr nonlinearities and their effect on the coherent beam combining efficiency. As such, we have simulated a high-power MOPA system modulated via filtered pseudo-random bit sequence format for different clock rates and power levels. We show that at clock rates of ≥30 GHz, the combination of GVD and self-phase modulation may lead to a drastic drop in beam combining efficiency at the multi-kW level. Furthermore, we extend our work to study the effect of cross-phase modulation where an amplifier is seeded with two laser sources.

The mammalian brain relies primarily on glucose as a fuel to meet its high metabolic demand. Among the various techniques used to study cerebral metabolism, 13C magnetic resonance spectroscopy (MRS) allows following the fate of 13C-enriched substrates through metabolic pathways. We herein demonstrate that it is possible to measure cerebral glucose metabolism in vivo with sub-second time resolution using hyperpolarized 13C MRS. In particular, the dynamic 13C-labeling of pyruvate and lactate formed from 13C-glucose was observed in real time. An ad-hoc synthesis to produce [2,3,4,6,6-2H5, 3,4-13C2]-D-glucose was developed to improve the 13C signal-to-noise ratio as compared to experiments performed following [U-2H7, U-13C]-D-glucose injections. The main advantage of only labeling C3 and C4 positions is the absence of 13C-13C coupling in all downstream metabolic products after glucose is split into 3-carbon intermediates by aldolase. This unique method allows direct detection of glycolysis in vivo in the healthy brain in a noninvasive manner.

In this paper we report the generation of flat top optical spectrum using an arbitrary waveform generator to increase the SBS threshold in high power optical fiber amplifiers. The optical spectrum consists of a number of discrete spectral lines, ranging from 16 to 380, within the bandwidth of 2GHz, corresponding to line spacing between 133 MHz and 5 MHz. These discrete spectral lines correspond to a PRBS pattern of n = 4 to n = 8. The SBS threshold and coherence properties of the flat top spectrum are measured and compared to that of the filtered PRBS in a kilowatt class fiber amplifier. It is experimentally demonstrated that for large frequency line spacing, the flat top spectrum significantly outperforms the corresponding filtered PRBS, but as the line spacing is decreased to less than the Brillouin bandwidth, the two modulation waveforms have similar enhancement factors in the SBS threshold due to the enhanced crosstalk between neighboring frequency components.

Hybrid microstructured fibers, utilizing both air holes and high index cladding structures, provide important advantages over conventional fiber including robust fundamental mode operation with large core diameters (>30μm) and spectral filtering (i.e. amplified spontaneous emission and Raman suppression). This work investigates the capabilities of a hybrid fiber designed to suppress stimulated Brillouin scattering (SBS) and modal instability (MI) by characterizing these effects in a counter-pumped amplifier configuration as well as interrogating SBS using a pump-probe Brillouin gain spectrum (BGS) diagnostic suite. The fiber has a 35 μm annularly gain tailored core, the center doped with Yb and the second annulus comprised of un-doped fused silica, designed to optimize gain in the fundamental mode while limiting gain to higher order modes. A narrow-linewidth seed was amplified to an MI-limited 820 W, with near-diffraction-limited beam quality, an effective linewidth ~ 1 GHz, and a pump conversion efficiency of 78%. Via a BGS pump-probe measurement system a high resolution spectra and corresponding gain coefficient were obtained. The primary gain peak, corresponding to the Yb doped region of the core, occurred at 15.9 GHz and had a gain coefficient of 1.92×10-11 m/W. A much weaker BGS response, due to the pure silica annulus, occurred at 16.3 GHz. This result demonstrates the feasibility of power scaling hybrid microstructured fiber amplifiers

Knowledge of the ice thickness distribution of glaciers and ice caps is an important prerequisite for many glaciological and hydrological investigations. A wealth of approaches has recently been presented for inferring ice thickness from characteristics of the surface. With the Ice Thickness Models Intercomparison eXperiment (ITMIX) we performed the first coordinated assessment quantifying individual model performance. A set of 17 different models showed that individual ice thickness estimates can differ considerably – locally by a spread comparable to the observed thickness. Averaging the results of multiple models, however, significantly improved the results: On average over the 21 considered test cases, comparison against direct ice thickness measurements revealed deviations in the order of 10 ± 24% of the mean ice thickness (1-sigma estimate). For models relying on multiple data sets -- such as surface ice velocity fields, surface mass balance, or rates of ice thickness change – the results highlighted the sensitivity to input data consistency. Together with the requirement of being able to handle large regions in an automated fashion, the capacity of better accounting for uncertainties in the input data will be a key for an improved next generation of ice thickness estimation approaches.

The Darwin–Hatherton Glacial system (DHGS) connects the East Antarctic Ice Sheet (EAIS) with the Ross Ice Shelf and is a key area for understanding past variations in ice thickness of surrounding ice masses. Here we present the first detailed measurements of ice thickness and grounding zone characteristics of the DHGS as well as new measurements of ice velocity. The results illustrate the changes that occur in glacier geometry and ice flux as ice flows from the polar plateau and into the Ross Ice Shelf. The ice discharge and the mean basal ice shelf melt for the first 8.5 km downstream of the grounding line amount to 0.24 ± 0.05 km3 a−1 and 0.3 ± 0.1 m a−1, respectively. As the ice begins to float, ice thickness decreases rapidly and basal terraces develop. Constructed maps of glacier geometry suggest that ice drainage from the EAIS into the Darwin Glacier occurs primarily through a deep subglacial canyon. By contrast, ice thins to

A diode pumped (793nm), long-wavelength thulium-doped all-fiber amplifier was demonstrated. Laser gain competition was used to suppress parasitic lasing and an output power of 80 W was generated at 2130nm with 50% optical efficiency.

Ka Roimata o Hine Hukatere (Franz Josef Glacier) is a fast-flowing maritime glacier and its climatological and hydrological drivers are different from those of many previously studied alpine glaciers. The glacier tongue has recently advanced as well as retreated, remains largely snow free, has significant volumes of melt and rainwater inputs throughout the year, and experiences small radiation and air temperature fluctuations over diurnal to seasonal time scales. We discuss measurements of surface velocity made between 2000 and 2012 at annual, seasonal, weekly, and daily time scales together with measurements of glacier geometry change, and calculations of surface water inputs and subglacial water pressure variations derived from a distributed surface mass balance model and a one-dimensional conduit hydrology model, respectively. Annual velocity variations are linked to changes in glacier geometry and advance/retreat cycles with accelerations during thickening and advance and decelerations during...

Compilation of modern and historical length change records for Franz Josef and Fox Glaciers demonstrates that these glaciers have lost ~ 3 km in length and at least 3–4 km 2 in area since the 1800s, with the greatest overall loss occurring between 1934 and 1983. Within this dramatic and ongoing retreat, both glaciers have experienced periods of re-advance. The record from Franz Josef Glacier is the most detailed, and shows major advances from 1946 to 1951 (340 m), 1965–1967 (400 m), 1983–1999 (1420 m) and 2004–2008 (280 m). At Fox Glacier the record is similar, with advances recorded during 1964–1968 (60 m), 1985–1999 (710 m) and 2004–2008 (290 m). Apart from the latest advance event, the magnitude of advance has been greater at Franz Josef Glacier, suggesting a higher length sensitivity. Analysis of the relationship between glacier length and a reconstructed annual equilibrium line altitude (ELA) record shows that the glaciers react very quickly to ELA variations — with the greatest correlation at 3–4 years' lag. The present (2014) retreat is the fastest retreat in the records of both glaciers. While decadal length fluctuations have been linked to hemispheric ocean–atmosphere variability, the overall reduction in length is a clear sign of twentieth century warming. However, documenting glacier length changes can be challenging; especially when increased surface debris-cover makes identification of the ‘true’ terminus a convoluted process.

This study examined the energy transfer ratio (ETR) of Central Mine Equipment (CME) automatic standard penetration test (SPT) hammers utilizing a large database of SPT energy measurements. The database consisted of energy measurements from 17,825 SPT hammer blows obtained from 33 CME automatic hammers over a 5-year period, many of which were tested multiple times. The average ETR for all 17,825 CME automatic hammer blows in the database was 82.9% with a COV of ±7.4%. The database also provided an opportunity to determine the impacts of hammer calibration, test depth, and calibration interval on the measured ETR. The impact on average ETR of eliminating hammer blows due to D4633-10 restrictions was also demonstrated.

Calcium chloride (CaCl2) has been used to accelerate strength gain in soil-cement mixtures. While its use in concrete is well established, there are few reports on dosage and temperature controls in soil-cement applications. This article provides laboratory and field data regarding the unconfined compression (UC) strength of soil-cement as a function of temperature, time, and dosage. The results indicate CaCl2 can increase the UC strength of soil-cement mixtures at curing temperatures of 2°C and 21°C while decreasing it dramatically if the initial temperature exceeds 50°C. At a 2°C curing temperature, a dosage of 1% CaCl2 (by weight of cement) increased the average 28-day UC strength from 1,618 to 1,869 kPa (+15.5%) while at 21°C the strength gain was significant at a dosage of 5% CaCl2, increasing the average 28-day UC strength from 1,916 to 2,338 kPa (+22.0%). In general, there is an optimum dosage that varies with temperature and soil type. In terms of field application, it is possible to use c...

Dexmedetomidine has established a firm position in the armamentarium of anesthesia pharmacology. However, it is still a relatively new drug and its application is based on early evidence that is intriguing but far from conclusive. Based on experience with previous cure-alls, anesthesia clinicians and researchers must insist on more information and formulate appropriate science that will allow us to truly understand the role of this dexmedetomidine in our specialty—as wonder drug or also-ran.

Climate proxy records from the middle to high latitude Southern Hemisphere indicate that a Lateglacial (15,000–11,500 years ago) climate reversal, approximately coeval with the Antarctic Cold Reversal (ACR), interrupted a warming trend during deglaciation. In New Zealand, some palaeoclimate proxy records indicate a cool episode during the ACR (ca 14,500–12,500 years ago), while others do not express a significant change in climate. Recently published moraine maps and ages present an opportunity to improve the palaeoclimate interpretation through numerical modelling of glaciers. We use a coupled energy-balance and ice-flow model to quantify palaeoclimate from past glacier extent constrained by mapped and dated moraines in the headwaters of Irishman Stream, a high-elevation catchment in the Southern Alps. First, a suite of steady-state model runs is used to identify the temperature and precipitation forcing required to fit the modelled glacier to well-dated Lateglacial moraine crests. Second, time-dependent glacier simulations forced by a nearby proxy temperature record derived from chironomids are used to assess the fit with the glacial geomorphic record. Steady-state experiments using an optimal parameter set demonstrate that the conditions under which the 13,000 year old moraine formed were 2.3–3.2 °C colder than present with the range in temperature corresponding to a ±20% variance in precipitation relative to the present-day. This reconstructed climate change relative to the present-day corresponds to an equilibrium-line altitude of ca 2000 ± 40 m above sea level (asl), which is ca 400 m lower than present. Time-dependent simulations of glacier length produce ice advance to within 100 m of the 13,000 year old terminal moraine, indicating that the chironomid-based temperature forcing and moraine record provide consistent information about past climate. Our results, together with other climate proxy reconstructions from pollen records and marine sediment cores, support the notion that temperatures during the ACR in New Zealand were ∼2–3 °C cooler than today.

The timing and magnitude of postglacial climatic changes around the globe provide insights into the underlying drivers of natural climate change. Using geomorphologic mapping of moraines, 10 Be surface-exposure dating, snowline reconstructions, and numerical modeling, we quantified glacier behavior during Late Glacial (15–11.5 ka) and Holocene (the past ∼11.5 k.y.) time in the Ben Ohau Range, New Zealand. Glaciers were more extensive during the Antarctic Cold Reversal (ACR), than subsequently, and the margins underwent a punctuated net withdrawal over the Holocene. Numerical modeling experiments that achieve the best fit to the moraines suggest that air temperature during the ACR was between 1.8 °C and 2.6 °C cooler than today, with similar (±20%) prescribed precipitation. After the ACR, a net snowline rise of ∼100 m through the Younger Dryas stadial (12.9–11.7 ka) was succeeded by a further "long-term," or net, rise of ∼100 m between ∼11 k.y. and ∼500 yr ago. Glacier snowline records in New Zealand show generally coherent Late Glacial and Holocene climate trends. However, the paleoclimate record in the southwest Pacific region shows important differences from that in the Northern Hemisphere.

Snow distribution patterns are still poorly understood in steep alpine catchments because of mass redistribution from wind and avalanching. Snow models rarely operate with sufficient resolution, physics or input data to resolve this issue explicitly, and existing sub-grid parameterisations are rarely tested in this type of terrain. To address this issue daily snow cover observations, obtained from a ground-based camera, are combined with a snow melt model to estimate the spatial distribution of snow water equivalent (SWE) in a mountainous alpine catchment. Results show the importance of slope in controlling the spatial distribution of SWE and snow duration. This distribution is linked to the physical process of gravitational transport, where there is removal of snow from steep slopes and preferential deposition on moderate-angle slopes. From a modelling perspective, if sub-grid snow variability is parameterised using a log-normal probability distribution (as is common in hydrological and land-use models) then ignoring steep/shallow slope differences leads to an overestimation of melt at the beginning of the melt season, and a premature end to the snow melt season. When modelling SWE in complex terrain, care should be taken to consider reduced SWE on steep slopes.

The selective α2-adrenoreceptor agonist dexmedetomidine has shown neuroprotective, analgesic, anti-inflammatory, and sympatholytic properties that may be beneficial in neonatal encephalopathy (NE). As therapeutic hypothermia is only partially effective, adjunct therapies are needed to optimize outcomes. The aim was to assess whether hypothermia + dexmedetomidine treatment augments neuroprotection compared to routine treatment (hypothermia + fentanyl sedation) in a piglet model of NE using magnetic resonance spectroscopy (MRS) biomarkers, which predict outcomes in babies with NE, and immunohistochemistry. After hypoxia-ischaemia (HI), 20 large White male piglets were randomized to: (i) hypothermia + fentanyl with cooling to 33.5°C from 2 to 26 h, or (ii) hypothermia + dexmedetomidine (a loading dose of 2 μg/kg at 10 min followed by 0.028 μg/kg/h for 48 h). Whole-brain phosphorus-31 and regional proton MRS biomarkers were assessed at baseline, 24, and 48 h after HI. At 48 h, cell death was evaluated over 7 brain regions by means of transferase-mediated d-UTP nick end labeling (TUNEL). Dexmedetomidine plasma levels were mainly within the target sedative range of 1 μg/L. In the hypothermia + dexmedetomidine group, there were 6 cardiac arrests (3 fatal) versus 2 (non-fatal) in the hypothermia + fentanyl group. The hypothermia + dexmedetomidine group required more saline (p = 0.005) to maintain blood pressure. Thalamic and white-matter lactate/N-acetylaspartate did not differ between groups (p = 0.66 and p = 0.21, respectively); the whole-brain nucleotide triphosphate/exchangeable phosphate pool was similar (p = 0.73) over 48 h. Cell death (TUNEL-positive cells/mm2) was higher in the hypothermia + dexmedetomidine group than in the hypothermia + fentanyl group (mean 5.1 vs. 2.3, difference 2.8 [95% CI 0.6-4.9], p = 0.036). Hypothermia + dexmedetomidine treatment was associated with adverse cardiovascular events, even within the recommended clinical sedative plasma level; these may have been exacerbated by an interaction with either isoflurane or low body temperature. Hypothermia + dexmedetomidine treatment was neurotoxic following HI in our piglet NE model, suggesting that caution is vital if dexmedetomidine is combined with cooling following NE.

To estimate hospitalisation costs for children with pertussis in New Zealand.All children less than 16 years of age and hospitalised with pertussis between 01/01/2003 and 31/12/2013 were identified from the National Minimum Data Set and the National Paediatric Intensive Care Unit database. The cost of hospital care was estimated by multiplying the diagnosis-related group cost-weight by the national price and inflating to 2013/2014 values.There were 1,456 children with pertussis admitted to hospital including 65 admissions to the paediatric intensive care unit. Infants (1 year) accounted for 78% of hospital admissions, 98% of paediatric intensive care admissions and 87% of hospitalisation costs. The total inflation-adjusted cost of the 11-year cohort was estimated at $8.3 million and the mean cost of hospital ward and paediatric intensive care was $4,242 and $42,016 respectively, per child. The 2011-2013 epidemic accounted for 39% of all hospital admissions and the cost estimated at $4.2 million. Peak annual hospitalisation costs during epidemic years increased from under $800,000 in 2004 and 2009 to over $2 million in 2012.Infants with pertussis are more likely than older children to be admitted to hospital and to the paediatric intensive care unit and generate the majority of hospitalisation costs. A revised focus on protecting vulnerable newborns and infants has the potential to both improve health outcomes for infants with pertussis and reduce medical costs.

Polychromatic laser light can reduce speckle contrast in wavefront-sensing and imaging applications that use direct detection schemes. To help quantify the associated reduction in speckle contrast, this study investigates the accuracy and numerical efficiency of three separate wave-optics models that simulate the active illumination of extended objects with polychromatic laser light. The three separate models use spectral slicing, Monte Carlo averaging, and depth slicing, respectively, to simulate the laser-target interaction. The sampling requirements of all three models are discussed. Comparisons to analytical solutions and experimental data are made when possible. In general, the experiments and theory compare favorably with the models.

We report power scaling results of a highly efficient narrow-linewidth monolithic Yb-doped fiber amplifier seeded with two signals, operating at 1038 and 1064 nm. With the appropriate seed power ratio applied, this technique was shown to suppress stimulated Brillouin scattering in conjunction with phase modulation, while generating the output power in predominantly the longer wavelength signal. Notably, the integration of laser gain competition with pseudo-random bit sequence phase modulation, set at a clock rate of 2.5 GHz and utilizing an optimized pattern to match the shortened effective nonlinear length, yielded 1 kW of output power. The beam quality was measured to be near the diffraction limit with no sign of transverse mode instability. Furthermore, the coherent beam combination performance of the amplifier provided a 90% combining efficiency with no indication of spectral broadening when compared to the single-tone case. Overall, the power scaling results represent a significant reduction in spectral linewidth compared to that of commercially available narrow-linewidth Yb-doped fiber amplifiers.

Type 1 Diabetes (T1D) is a chronic pro-inflammatory autoimmune disease consisting of islet-infiltrating leukocytes involved in pancreatic β-cell lysis. One promising treatment for T1D is islet transplantation; however, clinical application is constrained due to limited islet availability, adverse effects of immunosuppressants, and declining graft survival. Islet encapsulation may provide an immunoprotective barrier to preserve islet function and prevent immune-mediated rejection after transplantation. We previously demonstrated that a novel cytoprotective nanothin multilayer coating for islet encapsulation consisting of tannic acid (TA), an immunomodulatory antioxidant, and poly(N-vinylpyrrolidone) (PVPON), was efficacious in dampening in vitro immune responses involved in transplant rejection and preserving in vitro islet function. However, the ability of (PVPON/TA) to maintain islet function in vivo and reverse diabetes has not been tested. Recent evidence has demonstrated that modulation of redox status can affect pro-inflammatory immune responses. Therefore, we hypothesized that transplanted (PVPON/TA)-encapsulated islets can restore euglycemia to diabetic mice and provide an immunoprotective barrier. Our results demonstrate that (PVPON/TA) nanothin coatings can significantly decrease in vitro chemokine synthesis and diabetogenic T cell migration. Importantly, (PVPON/TA)-encapsulated islets restored euglycemia after transplantation into diabetic mice. Our results demonstrate that (PVPON/TA)-encapsulated islets may suppress immune responses and enhance islet allograft acceptance in patients with T1D.

An upper bound is derived for the McMillan degree of all H** infinity -optimal controllers using vector interpolation theory. The advantage of this method is that interpolation theory leads directly to a degree bound on all optimal closed loops. With this in hand, it is relatively easy to obtain a bound on the controller degree. A novel result on the degree of all optimal solutions to the matrix Nevanlinna-Pick problem.

All modern web browsers --- Internet Explorer, Firefox, Chrome, Opera, and Safari --- have a core rendering engine written in C++. This language choice was made because it affords the systems programmer complete control of the underlying hardware features and memory in use, and it provides a transparent compilation model. Unfortunately, this language is complex (especially to new contributors!), challenging to write correct parallel code in, and highly susceptible to memory safety issues that potentially lead to security holes. Servo is a project started at Mozilla Research to build a new web browser engine that preserves the capabilities of these other browser engines but also both takes advantage of the recent trends in parallel hardware and is more memory-safe. We use a new language, Rust, that provides us a similar level of control of the underlying system to C++ but which statically prevents many memory safety issues and provides direct support for parallelism and concurrency. In this paper, we show how a language with an advanced type system can address many of the most common security issues and software engineering challenges in other browser engines, while still producing code that has the same performance and memory profile. This language is also quite accessible to new open source contributors and employees, even those without a background in C++ or systems programming. We also outline several pitfalls encountered along the way and describe some potential areas for future improvement.

The design of Q-switched lasers capable of producing pulse widths of 100’s of picoseconds necessitates the cavity length be shorter than a few centimeters. Increasing the amount of energy extracted per pulse requires increasing the mode area of the resonator that for the same cavity length causes exciting higher order transverse modes and decreasing the brightness of the output radiation. To suppress the higher order modes of these multimode resonators while maintaining the compact cavity requires the use of intra-cavity angular filters. A novel Q-switched laser design is presented using transmitting Bragg gratings (TBGs) as angular filters to suppress the higher order transverse modes. The laser consists of a 5 mm thick slab of Nd:YAG, a 3 mm thick slab of Cr:YAG with a 20% transmission, one TBG aligned to suppress the higher order modes along the x-axis, and a 40% output coupler. The gratings are recorded in photo-thermo-refractive (PTR) glass, which has a high damage threshold that can withstand both the high peak powers and high average powers present within the resonator. Using a 4.1 mrad TBG in a 10.8 mm long resonator with an 800μm x 400 μm pump beam, a nearly diffraction limited beam quality of M2 = 1.3 is obtained in a 0.76 mJ pulse with a pulse width of 614 ps.

We report efficient coherent beam combining of five kilowatt-class fiber amplifiers with a diffractive optical element (DOE). Based on a master oscillator power amplifier (MOPA) configuration, the amplifiers were seeded with pseudo random phase modulated light. Each non-polarization maintaining fiber amplifier was optically path length matched and provides approximately 1.2 kW of near diffraction-limited output power (measured M2

We report results from two ~1.5 kW Yb-doped fiber amplifiers with comparable optical to optical efficiencies and linewidths. One amplifier utilized a fiber with a core diameter of 25 μm while the core diameter of the fiber utilized in the other amplifier was 20 μm. Stimulated Brillouin scattering (SBS) suppression in both cases was achieved through pseudo-random bit sequence (PRBS) phase modulation. While the power generated in the larger core fiber was modal instability (MI) limited, no sign of MI was observed in the smaller core fiber. This may allow us to utilize the higher MI threshold fiber to scale further while maintaining sufficiently narrow linewidth for beam combining. Furthermore, in a demonstration of the utility of applying a thermal gradient in conjunction with phase modulation to suppress SBS further, we report on a 1 kW amplifier driven at a PRBS clock rate of 2 GHz. Finally, we compare the coherent beam combining properties of amplifiers seeded with PRBS phase modulated sources to those seeded with white noise sources.

Laser gain competition was used in conjunction with external phase modulation techniques in order to investigate power scaling of narrow-linewidth monolithic Ytterbium-doped fiber amplifiers. In this study, both pseudo-random bit sequence (PRBS) and filtered white noise source (WNS) modulation techniques were separately utilized to drive the external phase modulator for linewidth broadening. The final-stage amplifier was then seeded with the phase modulated narrow-linewidth 1064 nm signal along with a spectrally broader 1038 nm source. Consequently, integration of laser gain competition in conjunction with PRBS phase modulation yields a factor of ∼15 dB in stimulated Brillouin scattering (SBS) threshold enhancement at a clock rate of 2.5 GHz; leading to 1 kilowatt of output power with 85% optical efficiency at 1064 nm. Notably, the combination of PRBS phase modulation with laser gain competition provided superior enhancement in SBS threshold power when compared to the WNS modulated case. The beam quality at maximum power was near the diffraction limit (M2

Tonsillectomy as a day-stay procedure remains controversial, although it is an established procedure in New Zealand. We reviewed our last 10 years' experience.A prospective audit was used to determine unplanned conversion from day-stay to overnight hospital admission rates and the incidence of postoperative complications.There were 5,400 tonsillectomies performed over the 10-year study period (January 2004-January 2015); 71% as outpatients. The unplanned conversion rate to overnight stay was 0.4%. The median age of day-stay patients was 6.5 years (range 13 months-15 years) compared with those admitted for overnight stay (5 years; range 8 months-15 years). The primary postoperative bleed rate was 0.5% (confidence interval [CI] 0.3%-0.7%), and the combined primary and secondary posttonsillectomy bleed rate was 4.3% (CI 3.8%-5.0%). The rate of patients returning with postoperative complications within 1 month of surgery was 6.3% (CI 5.6%-7.0%).Day-stay tonsillectomy in the pediatric population is safe when performed using the described guidelines in a facility with appropriate resources.4. Laryngoscope, 126:E416-E420, 2016.

Providing treatment to people with severe mental illnesses on an inpatient unit is fraught with challenges. Many patients are acutely ill and may be experiencing very severe symptoms that coexist with poor insight, emotional dysregulation, impulsivity, aggression, and severe disability. Moreover, many patients are involuntarily hospitalized and may be less cooperative with inpatient treatment. Some civilly committed patients may view their hospital tenure as needlessly lengthy and forced medications as impinging on their civil rights, while longing for less restrictive environments. For many practitioners, these are clinical challenges that adversely impact treatment adherence and ultimately positive treatment outcomes. There is accumulating evidence that the traditional model of decision making is insufficient in psychiatric care and may play a significant role in the reluctance of individuals who need mental health care to seek it and sustain their efforts in it. Shared decision-making, in contrast, provides a viable system of enhancing the engagement of care recipients in treatment and is an essential component of recovery-oriented practice. Inasmuch as it represents a change from the paternalistic model of traditional care, shared decision-making requires a shift in perspective and skill for both the provider and for the individual receiving mental health services. This chapter presents the concept of shared decision-making, explores provider attitudes, expectations and beliefs that may serve as barriers to its implementation, and provides practical strategies to facilitate effective shared decision-making in clinical care.

A low-pass filter is used to suppress the high-frequency components of a PRBS signal and is used to modulate a fiber amplifier. Notably, the coherence length and SBS threshold of a kilowatt-class amplifier are increased.

We present multi-kW power scaling results of narrow line Yb-doped fiber amplifiers. Nonlinear suppression is attained through pseudo-random modulation. Subsequently, 5 pseudorandom modulated kW amplifiers were coherently combined into a 5kW beam.

A potential complication in using glacier extent to estimate paleoclimatic conditions is the influence of glacier bed evolution on changes in ice extent over time. Here, we examine this issue through model-based reconstructions of the Last Glacial Maximum (LGM) Pukaki glacier, Southern Alps, New Zealand, whose LGM extents are exceptionally well defined by lateral and terminal moraines. Using the well-dated moraine limits as an empirical constraint on maximum ice extents, we employ a one-dimensional glacier flowline model driven by a mass balance model in order to evaluate the influence of climate and glacier bed profile on the extent of the LGM Pukaki glacier. The LGM glacier bed is buried by Lateglacial and post-glacial sediment, so we calculate bed profiles using a modified version of the one-dimensional model and available geologic constraints. A best fit to the moraine record occurs with a LGM temperature of 7–8 °C cooler than present, with precipitation ranging from 80% to 100% of present levels. Modeling of the bed profile evolution indicates that bed changes alone could account for kilometer-scale changes in glacier width and length.

We present a simulation of the New Zealand Southern Alps icefield at the Last Glacial Maximum (LGM, c. 30,000–20,000 calendar years ago (ka)) in an attempt to constrain the climate of that period. We use a 500 m-resolution ice-sheet model parameterised using empirical glaciological, climatological and geological data specific to the model domain to simulate the entire Southern Alps icefield. We find that an LGM cooling of at least 6–6.5 °C is necessary to bring about valley glaciers that extend beyond the mountains. However, climate–topography thresholds related to the elevation and hypsometry of individual catchments control the gradient of the rate of glacier expansion in the domain, and in order to remain within geologically reconstructed LGM limits we find that the LGM cooling was most likely associated with a precipitation regime up to 25% drier than today. Wetter-than-present scenarios give rise to equilibrium line depressions and ice extents that are incompatible with empirical evidence. These results perhaps indicate that either the westerly air masses affecting New Zealand during the LGM were drier than today, or that they were weaker or zonally displaced with respect to present.

Jointed micropiles were investigated to support bridge foundations where shallow rock was present. In this application, micropiles would have some amount of unsupported length, and would be subject to nominal lateral loads. Five lateral load tests were conducted on micropiles to demonstrate the impact of casing joints and rock socket embedment on lateral behavior. Load tests were simulated with FB-Multipier, a hybrid-finite element program for analysis of deep foundations, for proper design of the loading apparatus and instrumentation. The micropile sections were 2 m (6.56 ft) long, 273 mm (10.75 in) in diameter, 13 mm (0.5 in) thick walled, with a 50-mm (2-in) long threaded joint. Micropiles were made of one to three casing sections and were embedded 0.3, 0.6, 1.5, or 3.0 m (1, 2, 5, or 10 ft) into rock. In each test, two identical micropiles were pulled together using a simple frame until the weaker pile failed. All micropiles were instrumented with inclinometer casings while two contained strai...

‘The problem with simulations is that they are doomed to succeed.’ So runs a common criticism of simulations—that they can be used to ‘prove’ anything and are thus of little or no scientific value. While this particular objection represents a minority view, especially among those who work with simulations in a scientific context, it raises a difficult question: what standards should we use to differentiate a simulation that fails from one that succeeds? In this paper we build on a structural analysis of simulation developed in previous work to provide an evaluative account of the variety of ways in which simulations do fail. We expand the structural analysis in terms of the relationship between a simulation and its real-world target emphasizing the important role of aspects intended to correspond and also those specifically intended not to correspond to reality. The result is an outline both of the ways in which simulations can fail and the scientific importance of those various forms of failure.