Search

Schmidt-hammer exposure-age dating (SHD) was applied to selected rock glaciers in the south central Ben Ohau Range, Southern Alps, New Zealand, to expand the available regional data set following a previous pilot study. Additional SHD-sampling was conducted on high-altitudinal moraines at two locations with published cosmogenic 10Be surface-exposure ages and utilised to establish a new regional SHD-age calibration equation. SHD-age estimates available for a total of eight rock glaciers and based on >16,000 sampled boulders were analysed in a chronological, morphodynamic, and palaeoclimatic context. SHD-age estimates for initiation of rock glacier formation indicated by the age of their respective frontal ridges spread between 12.1 ± 1.6 and 7.2 ± 0.8 ka with a cluster of four individual features between 9.3 and 8.6 ka. Activity at some rock glaciers commenced immediately after local deglaciation and all are considerably older than previously anticipated. Successive transverse ridges dated on the rock glaciers reveal a clear general trend of increasing age with increasing distance from the rooting zone. This reflects conveyor-like transport of boulders in predominantly stable position on the surface. The SHD-age estimates of the ridges themselves are interpreted as morphological evidence for phases of strong morphodynamic activity connected to cold periods and increased debris supply by climate-driven frost weathering. All investigated rock glaciers show a climax of such activity during the Early Holocene. After c. 7.0 ka such phases became less frequent and subsequently rare during the Late-Holocene. These newly obtained chronological constraints for rock glacier activity are discussed in the context of related palaeoclimatic conditions and their potential to complement the hitherto limited regional palaeoclimatic records for the Early Holocene based on glacial activity. [ABSTRACT FROM AUTHOR]

Schmidt-hammer exposure-age dating (SHD) was applied to ~180 medium- to large-scale solifluction features on the northern edge of Juyflye, Jotunheimen (southern Norway) using an electronic Schmidt-hammer (RockSchmidt) and an improved local SHD age-calibration equation. Age estimates from four different types of solifluction landforms were analysed and compared with those from recalibrated estimates from patterned ground previously investigated on Juvflye. Average SHD-age estimates are c. 9.8 and 9.3 ka for the two dominant morphological types of solifluction features ('type A' boulder tongues and 'type B' stone-banked solifluction lobes) and c. 8.6 ka for sorted stripes and circles. Our results indicate that active formation of all investigated types of solifluction features, sorted stripes, and sorted circles ceased in the Early Holocene, prior to the onset of the regional Holocene Thermal Maximum (HTM) at c. 7.7 ka. Formation of all of these periglacial landforms appears to have commenced shortly after local deglaciation (c. 11.4 ka) in water-saturated till. Alternative origins are rejected, including the possibility of development before the last glaciation, survival beneath cold-based glaciers, and exhumation in the Early Holocene. Cessation of activity is attributed to changing ground conditions affecting active layer processes, particularly reduced soil moisture and pore water pressure. Temporal variations of the altitudinal permafrost limits had little or no impact on the timing of either the Early Holocene climax in activity or subsequent stabilisation. Caution is therefore urged in the utilisation of large-scale solifluction and patterned ground landforms as palaeoclimatic indicators. • Successful application of SHD and improved local age-calibration equation • Climax in periglacial activity during Early Holocene • Stabilisation of solifluction and patterned ground prior to HTM • No relationship between stabilisation and altitudinal permafrost limit • Active layer conditions crucial not presence of underlying permafrost [ABSTRACT FROM AUTHOR]

Incorrect offsets between a satellite's center of mass and its global navigation satellite system antenna phase center pose challenges to the precise orbit determination (POD) of many current Earth observation missions. Based on hardware-in-the-loop simulations, this paper demonstrates the more adverse effects on agile satellites, which perform frequent attitude maneuvers around all spacecraft axes. However, findings obtained from an observability analysis and Monte Carlo simulations indicate that rapid attitude changes enable the direct estimation of otherwise unobservable offsets. Application to the POD of agile satellites leads to a consistent and significant performance improvement in the presence of incorrect phase center offsets. Directly estimated corrections for the phase center offset of Sentinel-6A, which performs slews on several occasions, are consistent with values obtained from other studies via independent methods. These results underscore the possibility of estimating the lever arm for both agile and non-agile satellites in dedicated calibration maneuvers. [ABSTRACT FROM AUTHOR]

Unreported Missense Mutation in the Dimerization Domain of ADA2 Leads to ADA2 Deficiency Associated with Severe Oral Ulcers and Neutropenia in a Female Somalian Patient - Addendum to the Genotype-Phenotype Puzzle B The electropherogram of the reverse strand of ADA2 of patient and her heterozygous daughter. c The white blood count (WBC) measured in giga per liter (G/L) of the patient before and after the switch from cyclosporine A to TNF- blocking therapy. Despite this treatment, granulocyte levels could only be maintained at low-normal levels with continuous cortisone treatment and the patient was hospitalized several times in the subsequent 2 years for oral ulcers and severe bacterial skin abscesses. [Extracted from the article]

The investigation of periglacial and related landforms in South Norway is of great interest for exploring the timing of deglaciation and to assess their geomorphological connectivity to palaeoclimatic changes during the Late Pleistocene and the Holocene. The ice margins of the Scandinavian Ice Sheet during the Last Glacial Maximum (LGM) are reasonably well established. Palaeo-ice thickness can, however, only be estimated by modelling and remains uncertain over large parts of Norway due to sparse field based evidence. Because of the significant influence of the former horizontal and vertical ice-sheet extent on sea-level rise, atmospheric and oceanic circulation patterns, erosive properties of glaciers and ice sheets, englacial thermal boundaries, and deglaciation dynamics, it is crucial to improve the understanding of the topographic properties of the LGM ice sheet. Despite recent progress, there is a lack of terrestrial evidence in the form of numerical age data from South Norway. In this study two high-mountain regions and their surroundings in west (Dalsnibba, 1476 m a.s.l.) and east (Blåhø, 1617 m a.s.l.) South Norway were studied to reconstruct palaeoclimatic conditions and deglaciation patterns. Terrestrial cosmogenic nuclide (10Be) and Schmidt-hammer exposure-age dating (SHD) have been utilized to determine the surface exposure age of glacially transported boulders as well as of boulder-dominated glacial, periglacial, and paraglacial landforms and bedrock outcrops. By developing calibration curves at both study sites for the first time it was possible to obtain landform-age estimates from Schmidt hammer R-(rebound) values. In addition, the formation and stabilization of those landforms and the formative processes have provided indications about the Late Pleistocene and Holocene climate variability and its connectivity to landform development. [ABSTRACT FROM AUTHOR]

Schmidt-hammer exposure-age dating (SHD) was applied to a variety of boulder-dominated periglacial landforms in an attempt to establish a local mid-/late-Holocene chronology for the Geirangerfjellet in South Norway. Landform ages were obtained by application of a local calibration curve for Schmidt hammer R-values based on young and old control points comprising fresh road cuts and a bedrock surface in proximity to the study area, respectively. The area was deglaciated ~11.5 ka ago according to independent age information. Investigation of age, formation and stabilization of the periglacial landforms and processes involved allowed assessment of the underlying Holocene climate variability and its relationship to landform evolution. Our SHD ages range from 7.47 ± 0.73 ka for glacially abraded bedrock at the valley bottom to 2.22 ± 0.49 ka for surface boulders of a rock-slope failure. All landforms shared negative skewness and largely have narrow tailed frequency distributions of their R-values. This points to either substantial reworking of the boulders within a landform or continuous debris supply. Our results show that most landforms stabilized during the Holocene Thermal Maximum (~8.0–5.0 ka). The findings do not support the hypothesis that rock-slope failures predominately occur shortly after local deglaciation. Instead, it appears that they cluster during warm periods due to climate-driven factors, for example, decreasing permafrost depth or increasing cleft-water pressure leading to slope instabilities. Periglacial boulder-dominated landforms in the western maritime fjord region seem to react sensitively to Holocene climate variability and may constitute valuable but to date mostly unexplored sources of palaeoclimatic information. [ABSTRACT FROM AUTHOR]

Rock‐slope failures (RSFs) constitute significant natural hazards, but the geophysical processes that control their timing are poorly understood. However, robust chronologies can provide valuable information on the environmental controls on RSF occurrence: information that can inform models of RSF activity in response to climatic forcing. This study uses Schmidt‐hammer exposure‐age dating (SHD) of boulder deposits to construct a detailed regional Holocene chronology of the frequency and magnitude of small rock‐slope failures (SRSFs) in Jotunheimen, Norway. By focusing on the depositional fans of SRSFs (≤103 m3), rather than on the corresponding features of massive RSFs (~108 m3), 92 single‐event RSFs are targeted for chronology building. A weighted SHD age–frequency distribution and probability density function analysis indicated four centennial‐ to millennial‐scale periods of enhanced SRSF frequency, with a dominant mode at ~4.5 ka. Using change detection and discreet Meyer wavelet analysis, in combination with existing permafrost depth models, we propose that enhanced SRSF activity was primarily controlled by permafrost degradation. Long‐term relative change in permafrost depth provides a compelling explanation for the high‐magnitude departures from the SRSF background rate and accounts for: (i) the timing of peak SRSF frequency; (ii) the significant lag (~2.2 ka) between the Holocene Thermal Maximum and the SRSF frequency peak; and (iii) the marked decline in frequency in the late‐Holocene. This interpretation is supported by geomorphological evidence, as the spatial distribution of SRSFs is strongly correlated with the aspect‐dependent lower altitudinal limit of mountain permafrost in cliff faces. Results are indicative of a causal relationship between episodes of relatively warm climate, permafrost degradation and the transition to a seasonal‐freezing climatic regime. This study highlights permafrost degradation as a conditioning factor for cliff collapse, and hence the importance of paraperiglacial processes; a result with implications for slope instability in glacial and periglacial environments under global warming scenarios. [ABSTRACT FROM AUTHOR]

Schmidt-hammer exposure-age dating (SHD) was performed on blockfields and related landforms on Blåhø, Southern Norway. By developing a linear high-precision age-calibration curve through young and old control points of known age from terrestrial cosmogenic nuclide dating, it was possible to gain landform age estimates based on Schmidt hammer R-values. The aim of this study is to relate formation and subsequent stabilization of the landforms investigated to climate fluctuations since the Last Glacial Maximum (LGM) and to explore the palaeoclimatic implication of such periglacial landforms. The SHD ages range from 19.14 ± 0.91 ka for the Rundhø blockfield to 5.32 ± 0.73 ka for the lowest elevation rock-slope failure. The R-value frequency distributions obtained on the landforms studied indicate complex, longterm formation histories. Landforms above 1450 m a.s.l. share comparable SHD ages and seem to have stabilized during the Karmøy/ Bremanger readvance (~18.5-16.5 ka). The lower elevation rock-slope failures most likely occurred during the Bølling-Allerød interstadial (~14.7-12.9 ka) and the Holocene Thermal Maximum (~8.0-5.0 ka). The results contrast with the established model that rock-slope failures occur within the first millennia following deglaciation. Instead of the inferred ice coverage above 1450 m a.s.l. until 15.0 ± 1.0 10Be ka, our results suggest severe periglacial and ice-free conditions occurred earlier. Landforms above 1450 m a.s.l. do not show any form of reactivation during cold periods within the Late Glacial and Holocene. Our SHD results suggest that the landforms investigated were (at least partly) generated prior the LGM and survived beneath cold-based ice or were located on nunataks. [ABSTRACT FROM AUTHOR]

Investigating Holocene glacier chronologies constitutes a valuable approach within palaeoclimatic research. Recent progress of numerical dating techniques, in particular terrestrial cosmogenic nuclide dating (TCND), has given it new momentum. Highly increased precision and improved methodological procedures of data calibration seem, however, to have gradually pushed previous rigorous geomorphological analysis of the investigated glacier forelands aside. By using a well-known key site in the Southern Alps/New Zealand it is demonstrated that even alleged benchmark studies are not immune to geomorphological uncertainties. Considerable potential misinterpretations are alerting and reinforce the demand for an unaltered ‘supremacy' of geomorphology in this context. Especially with global compilations aiming at wider palaeoclimatic conclusions critical re-assessment of glacier chronologies may occasionally seem necessary. [ABSTRACT FROM AUTHOR]

Two rock glaciers in the valley head of Irishman Stream in the central Ben Ohau Range, Southern Alps/New Zealand, have been investigated using the electronic Schmidt-hammer (SilverSchmidt). Longitudinal profiles on both features reveal a consistent trend of decreasing R(Rebound)-values and, hence, increasing weathering intensity and surface-exposure age on their numerous transverse surface ridges from rooting zone towards the front. Previously published numerical ages obtained by terrestrial cosmogenic nuclide dating (TCND) allowed the calculation of a local Schmidt-hammer exposure-age dating (SHD) age-calibration curve by serving as the required fixed points. Age estimates for the lowermost rock glacier surface ridges fall within the early Holocene between 12 and 10.5 ka and indicate a fast disappearance of the Late Glacial glacier formerly occupying the valley head, followed by the initiation of rock glacier formation around or shortly after the onset of the Holocene. Although it cannot be judged whether the rock glaciers investigated were active within the entire Holocene or only repeatedly during multiple episodes within, their location and intact morphology exclude any substantial glacial activity at Irishman Stream during the Holocene. This has considerable regional palaeoclimatic implications because it opens for the hypothesis that climatic conditions during early Holocene were possibly comparatively dry and favourable for rock glacier initiation, but less so for glaciers. It would also challenge the view that air temperature is the sole major climate driver of glacier variability in the Southern Alps. More work utilising the palaeoclimatic potential of rock glaciers in the Southern Alps is advised. [ABSTRACT FROM AUTHOR]

We report a human case of ocular Dirofilaria infection in a traveler returning to Austria from India. Analysis of mitochondrial sequences identified the worm as Candidatus Dirofilaria hongkongensis, a close relative of Dirofilaria repens, which was only recently described in Hong Kong and proposed as a new species. [ABSTRACT FROM AUTHOR]

ABSTRACT Periglacial patterned ground (sorted circles and polygons) along an altitudinal profile at Juvflya in central Jotunheimen, southern Norway, is investigated using Schmidt-hammer exposure-age dating (SHD). The patterned ground surfaces exhibit R-value distributions with platycurtic modes, broad plateaus, narrow tails, and a negative skew. Sample sites located between 1500 and 1925 m a.s.l. indicate a distinct altitudinal gradient of increasing mean R-values towards higher altitudes interpreted as a chronological function. An established regional SHD calibration curve for Jotunheimen yielded mean boulder exposure ages in the range 6910 ± 510 to 8240 ± 495 years ago. These SHD ages are indicative of the timing of patterned ground formation, representing minimum ages for active boulder upfreezing and maximum ages for the stabilization of boulders in the encircling gutters. Despite uncertainties associated with the calibration curve and the age distribution of the boulders, the early-Holocene age of the patterned ground surfaces, the apparent cessation of major activity during the Holocene Thermal Maximum (HTM) and continuing lack of late-Holocene activity clarify existing understanding of the process dynamics and palaeoclimatic significance of large-scale sorted patterned ground as an indicator of a permafrost environment. The interpretation of SHD ages from patterned ground surfaces remains challenging, however, owing to their diachronous nature, the potential for a complex history of formation, and the influence of local, non-climatic factors. [ABSTRACT FROM AUTHOR]

Computer vision applications that involve the matching of local image features frequently use Ratio-Match as introduced by Lowe and others, but is this really the optimal approach? We formalize the theoretical foundation of Ratio-Match and propose a general framework encompassing Ratio-Match and three other matching methods. Using this framework, we establish a theoretical performance ranking in terms of precision and recall, proving that all three methods consistently outperform or equal Ratio-Match . We confirm the theoretical results experimentally on over 3000 image pairs and show that matching precision can be increased by up to 20 percentage-points without further assumptions about the images we are using. These gains are achieved by making only a few key changes of the Ratio-Match algorithm that do not affect computation times. [ABSTRACT FROM AUTHOR]

Mean opinion score (MOS) has become a very popular indicator of perceived media quality. While there is a clear benefit to such a 'reference quality indicator' and its widespread acceptance, MOS is often applied without sufficient consideration of its scope or limitations. In this paper, we critically examine MOS and the various ways it is being used today. We highlight common issues with both subjective and objective MOS and discuss a variety of alternative approaches that have been proposed for media quality measurement. [ABSTRACT FROM AUTHOR]

Caspase-1 is a unique cysteine protease playing central roles in innate immunity. Pathogens, stress, and damage signals induce activation of caspase-1, typically mediated by proximity-induced autoproteolysis in multimeric protein complexes called the inflammasome. Active caspase-1 induces secretion of pro-inflammatory cytokines and mediates pyroptosis, a programmed pro-inflammatory cell death, thereby initiating an immune response finally leading to pathogen clearance. Excessive activation of caspase-1 is the underlying cause for rare diseases such as periodic fever syndromes, and more common disorders, including atherosclerosis, type 2 diabetes, and gout. Beside these well-known pro-inflammatory functions, active caspase-1 also has anti-inflammatory and protective functions contributing to cell survival, reduced inflammatory cytokine signaling, and improved outcomes in mouse models of burn injury or trauma and shock. Furthermore, naturally occurring procaspase-1 variants with reduced or abrogated enzymatic activity mediate enhanced inflammatory signaling and have been associated to autoinflammatory symptoms. Here, we review functions of caspase-1 focusing on anti-inflammatory signaling pathways and discuss the role of enzymatically inactive caspase-1 as disease-promoting factors in autoinflammatory diseases. Moreover, we illustrate differential requirements for autoproteolysis and enzymatic activity in caspase-1 functions. [ABSTRACT FROM AUTHOR]

High-precision Schmidt-hammer exposure-age dating ( SHD) is applied to ice-cored moraine-ridge complexes at three high-alpine glaciers in Jotunheimen and Breheimen, southern Norway. Local calibration curves were established using moraine ridges dating from the last 50 years and bedrock surfaces deglaciated ∼9700 years ago. SHD ages, with 95% statistical confidence intervals, ranged from 3920 ± 790 years to a negative (futuristic) age of -890 ± 580 years at Gråsubreen, 420 ± 700 to 260 ± 710 years at Vesle-Juvbreen and 2250 ± 450 to 1605 ± 410 years at Østre Tundradalskyrkjabreen. Negatively skewed R-value distributions were interpreted as the result of weathered boulders from reworked surfaces. This leads to the interpretation of these SHD ages as maximum estimates of moraine-ridge age. Østrem's hypothesis (that the proximal ridges are the oldest and survived being overridden many times) is rejected on the basis of our SHD ages. Although ice-cored moraine ridges resemble the flow structures of rock glaciers, Barsch's hypothesis (that these ice-cored moraine complexes are rock glaciers) is also rejected. Instead, the ice-cored moraine-ridge complexes are considered to be glaciotectonic structures produced by the interaction of polythermal glaciers and alpine permafrost over the late Holocene. All the individual ridges were essentially formed during the ' Little Ice Age' glacier advance from material deposited earlier by multiple neoglacial events. The considerable size of the moraine complexes is attributed not only to the accumulation of material from these different events over a long period of time but also to their survival in the landscape during phases of glacier retreat when ice cores do not melt and fluvial and other destructive processes remain ineffective in the permafrost environment. [ABSTRACT FROM AUTHOR]

The proinflammatory enzyme caspase-1 plays an important role in the innate immune system and is involved in a variety of inflammatory conditions. Rare naturally occurring human variants of the caspase-1 gene (CASP1) lead to different protein expression and structure and to decreased or absent enzymatic activity. Paradoxically, a significant number of patients with such variants suffer from febrile episodes despite decreased IL-1β production and secretion. In this study, we investigate how variant (pro)caspase-1 can possibly contribute to inflammation. In a transfection model, such variant procaspase-1 binds receptor interacting protein kinase 2 (RIP2) via Caspase activation and recruitment domain (CARD)/CARD interaction and thereby activates NF-κB, whereas wild-type procaspase-1 reduces intracellular RIP2 levels by enzymatic cleavage and release into the supernatant. We approach the protein interactions by coimmunoprecipitation and confocal microscopy and show that NF-κB activation is inhibited by anti-RIP2-short hairpin RNA and by the expression of a RIP2 CARD-only protein. In conclusion, variant procaspase-1 binds RIP2 and thereby activates NF-κB. This pathway could possibly contribute to proinflammatory signaling. [ABSTRACT FROM AUTHOR]

Boulder-dominated landforms of periglacial, paraglacial and related origin constitute a valuable, but often unexplored source of palaeoclimatic and morphodynamic information. The timing of landform development initiation and its subsequent stabilization can be linked to past climatic conditions offering the potential to reconstruct cold climatic periods. In this study, Schmidt-hammer exposure-age dating (SHD) was applied to a variety of boulder-dominated landforms (sorted stripes, blockfield, rock-slope failure, paraglacial alluvial fan) in Rondane, eastern South Norway for the first time. On the basis of old and young control points a regional SHD calibration curve was established and successively utilized for the calculation of surface exposure ages for individual landforms. The chronological investigation of development and stabilization of the respective landforms permitted an assessment of Holocene climate variability in Rondane and its impact on overall landform evolution. Our obtained SHD age estimates ranged from 11.44 ± 1.22 ka (ST-D2) to 4.09 ± 1.51 ka (AF1) showing their inactive and relict character. Most surface exposure ages for sorted stripes clustered between 9.88 ± 1.35 ka and 9.25 ± 1.21 ka, hence indicating stabilization during the late stage of the Erdalen Event or shortly thereafter. It is inferred that the blockfield formed prior to the Last Glacial Maximum, was protected by cold-based ice throughout glaciation and shortly reactivated during the Erdalen Event only to subsequently becoming inactive. The surface exposure age of a rock-slope failure (7.58 ± 0.73 ka) falls into the early phase of the Holocene Thermal Maximum (HTM, ~8.0–5.0 ka). This indicates permafrost degradation and/or increasing hydrological pressure negatively influencing slope stability. The paraglacial alluvial fan with its four subsites yielded ages between 8.73 ± 1.63 ka and 4.09 ± 1.51 ka. The old exposure ages point to fan aggradation following regional deglaciation due to paraglacial processes, whereas the younger ages can be explained by increasing precipitation during the onset neoglaciation at ~4.0 ka. Our results underline the importance of meltwater for the activation of periglacial landforms in a continental climate and indicate that the Erdalen Event and immediately following onset of the HTM had major impact on landscape evolution in Rondane. Our obtained surface exposure ages from boulder-dominated landforms in Rondane give important insights into the local palaeoclimatic variability during the Holocene. • Successful application of Schmidt-hammer exposure-age dating • First surface exposure ages of peri- and paraglacial landforms from Rondane • Stabilization of landforms during a late stage of the Erdalen Event • Lack of moisture due to continentality was compensated by meltwater supply. • Paraglacial alluvial fan development steered by debris flows throughout the Holocene [ABSTRACT FROM AUTHOR]

Schmidt-hammer exposure-age dating (SHD) is a numerical, calibrated-age dating technique based on the degree of weathering of rock surfaces. The Schmidt hammer measures the hardness or strength of a rock surface by means of R-values (rebound values), which are produced as the hammer impacts the surface. Age calibration is carried out with reference to at least two surfaces of known age (control surfaces). Mean R-values then yield numerical estimates of the time elapsed since exposure of rock surfaces to subaerial weathering. Under favourable circumstances with a sufficiently large number of impacts, SHD has an age resolution of 300–500 years for rock surfaces exposed during the Holocene and Late Pleistocene, and a current age range of ~25 ka. Accurate independent dating of control surfaces and careful selection of sites to reduce the effects of lithological variability are essential. R-value distributions are an important aid in the interpretation of SHD ages from active and relict, synchronous and diachronous, single and multiple-event surfaces. Important research applications have been made within the fields of Quaternary geochronology, palaeoenvironmental reconstruction, geomorphology and subaerial processes, and landscape dynamics. SHD has been found particularly useful in relation to boulder deposits and bedrock surfaces in glacial and periglacial environments. There is much untapped potential in coastal, temperate and tropical landscapes wherever rock surfaces are exposed to undisturbed rock weathering. The advantages and limitations of SHD compare favourably with the complementary exposure-age technique of terrestrial cosmogenic nuclide dating (TCND). The capability to provide a large number of exposure ages at low cost, and non-destructively in sensitive natural and artefactual settings, are special strengths of SHD. [ABSTRACT FROM AUTHOR]

Chronological studies applying Schmidt-hammer exposure-age dating (SHD) were performed on six glacier forelands in the western part of the Southern Alps, New Zealand. Although lithological heterogeneity prevented a regional age-calibration curve to be established, local age-calibration curves for La Perouse Glacier and Strauchon Glacier could be derived. They show similar linear equations and trends/slopes and enabled a preliminary assessment of the representativeness of individual 10Be terrestrial cosmogenic nuclide dating (TCND)-ages obtained from the other forelands. No mid- and early-Holocene advance periods were detected. Clusters of moraine ages date around 2800, 1850–1450, and 1100–900 years ago, followed by the ‘Little Ice Age’ commencing c. 500 years ago. There is no good agreement with earlier radiocarbon-based studies and recently published TCND-chronologies. As it will be outlined, this partly could be the result of different approaches to the palaeoclimatic interpretation of the dated samples. The results obtained from this recent study do not support an elsewhere proposed general asynchronous glacier behaviour between the mid-latitudinal Northern and Southern hemispheres. [ABSTRACT FROM AUTHOR]

Abstract: Stereoscopic 3D content brings with it a variety of complex technological and perceptual issues. For the percept of depth to be convincing, consistent, and comfortable, a large number of parameters throughout the imaging and processing pipeline need to be matched correctly. In practice, tradeoffs are inevitable, which may then affect the quality or comfort of the 3D viewing experience. This paper reviews stereo/multiview picture quality from an engineering perspective. With a focus on recent or emerging approaches and technologies used in 3D systems, it addresses in particular depth issues, multiview issues, display issues, viewer issues, as well as possible measurements and standards for 3D quality. [Copyright &y& Elsevier]

Matthews, J. A. & Winkler, S. 2010: Schmidt-hammer exposure-age dating (SHD): application to early Holocene moraines and a reappraisal of the reliability of terrestrial cosmogenic-nuclide dating (TCND) at Austanbotnbreen, Jotunheimen, Norway. Boreas, 10.1111/j.1502-3885.2010.00178.x. ISSN 0300-9483. Schmidt-hammer exposure-age dating (SHD) and terrestrial cosmogenic-nuclide dating (TCND) are complementary techniques that can be used for mutual testing. SHD is low-cost but requires local control points of known age and may be affected by local geological variation and other environmental factors that influence weathering rates. TCND is vulnerable to the occurrence of anomalous boulders, other geomorphological uncertainties and the effects of snow-shielding at high altitudes. Both techniques are sensitive to post-depositional disturbances if other than solid bedrock is sampled. SHD was applied to two moraine ridges beyond the Little Ice Age limit of Austanbotnbreen in the Hurrungane massif, southern Norway. Independent regional and experimental local age-calibration curves were used to reappraise previous TCND results. Neither the two boulder surfaces nor their proximal bedrock surfaces could be differentiated statistically in terms of SHD exposure ages or their mean R-values (±95% confidence intervals), which ranged from 40.73±1.72 to 43.34±0.69. The best of the independent regional-calibration curves produced SHD exposure ages of 9413±723 and 9304±602 years, which are consistent with moraine formation early ( c. 10.2 ka) and late ( c. 9.7 ka) within the late-Preboreal Erdalen Event. The current precision of SHD, as reflected in 95% confidence intervals of ±500-900 years, enables rejection of a Finse Event ( c. 8.2 ka) age for either moraine. Results are consistent with a retracted Austanbotnbreen between the Erdalen Event and the Little Ice Age, and a modified model of Neoglaciation. [ABSTRACT FROM AUTHOR]

Slam events experienced by high-speed catamarans in irregular waves were characterised through experiments using a hydroelastic segmented model. The model was designed to represent the dynamic behaviour of the full-scale Incat 112 m vessel and to allow the measurement of the slam load on the centrebow and wet deck. It was tested in irregular head seas at two speeds relating to Froude numbers of 0.32 and 0.60. Nearly 300 slams were identified in the test data and analysed with respect to kinematic parameters. Slams were found to have a large range of magnitudes, with the largest equivalent to 1785 tonnes full scale (approximately 70% of vessel displacement); however, the majority of events were of relatively low severity. Differences in slam characteristics were found for the two model speeds tested; slams at the slower speed generally occurred further forward on the hull, prior to the wave crest and with a bow down pitch angle. Immersion of the centrebow to the two-dimensional filling height of the cross-section between the centrebow and demihulls is shown to be a better indicator of slam occurrence than immersion to the top of the archway. [ABSTRACT FROM AUTHOR]

In the context of reconstruction of Holocene glacier chronologies, there has been a clear tendency during the past few decades towards imprecise use of the term ‘high resolution’. Furthermore, it seems to be increasingly assumed that recently developed terrestrial cosmogenic nuclide dating (TCND) is replacing earlier dating methods. Although recent glaciological knowledge clearly reveals the futility of oversimplified global and inter-hemispheric correlation on the basis of few ‘key’ sites, such comparisons are widely attempted. Stimulated by the example of a recently published article relating to the Southern Alps of New Zealand (Schaefer et al., 2009, Science 324: 622—625) we highlight some related potential problems with the interpretation of Holocene glacier chronologies. In particular, we consider (1) that the term ‘high resolution’ should be applied only to decadal-scale resolution or better and, therefore, not to TCND-based chronologies; (2) that discontinuous moraine chronologies should not be termed high resolution and that their potential geomorphological limitations should be acknowledged; and (3) that TCND-based moraine chronologies should not automatically replace evidence available from other dating techniques but that they should be regarded as complementary and an opportunity for mutual evaluation. Owing to local and regional patterns in glacier response to climate, it is concluded (4) that intra-hemispheric synchroneity in high-resolution Holocene glacier variations is still unproven, and hence (5) that inter-hemispheric comparison is arguably premature, if not impossible. Finally, it is suggested (6) that the first priority for research in this field should be to establish the spatial patterns in glacier behaviour evident at various scales in Holocene records. [ABSTRACT FROM PUBLISHER]

Traceability—the ability to follow the life of software artifacts—is a topic of great interest to software developers in general, and to requirements engineers and model-driven developers in particular. This article aims to bring those stakeholders together by providing an overview of the current state of traceability research and practice in both areas. As part of an extensive literature survey, we identify commonalities and differences in these areas and uncover several unresolved challenges which affect both domains. A good common foundation for further advances regarding these challenges appears to be a combination of the formal basis and the automated recording opportunities of MDD on the one hand, and the more holistic view of traceability in the requirements engineering domain on the other hand. [ABSTRACT FROM AUTHOR]

Abstract: The formation of terminal moraines dating from glacier advances during the A.D. 1990s was investigated at six temperate glaciers in the Jostedalsbreen and Jotunheimen regions of southern Norway. Morphological and sedimentological information was analysed and combined with detailed observations, photographic evidence, and length variation measurements. Bulldozing (pushing) of proglacial sediments was the predominant process at the low-lying glacier termini of the debris-free outlets of the Jostedalsbreen ice cap. Evidence for bulldozing includes the relocation and rotation of boulders and the presence of lichen-covered boulders in the distal slopes of moraines. Differences in moraine sedimentology between the individual sites are attributed to variations in the pre-existing material pushed up, rather than to specific processes. In Jotunheimen, several modes of moraine-ridge formation were active: dumping of supraglacial debris and the marginal freezing-on and subsequent melting-out of subglacial sediment slabs were more important than bulldozing at some sites and in some years. Low air temperatures in winter at the higher altitude glacier termini enabled freezing-on to occur. However, the forelands are below the lower limit of discontinuous permafrost and evidence of thrusting is absent. Whereas discrete terminal moraine ridges at Jostedalsbreen are related to (seasonal) advances, the less dynamic glaciers of Jotunheimen allow the accretion of successive ridges during consecutive years. No single regional mode of moraine formation is characteristic for southern Norway: several processes are involved depending on individual glacier morphology and dynamics, the glaciological regime, and environmental conditions (especially climate) on the glacier forelands. The importance of specific processes varies within and between glacier forelands. Thus, spatial and temporal variation and local individuality has to be taken into account in the interpretation of moraine-ridge formation. Similar variability is likely to have been characteristic of terminal moraines deposited during the “Little Ice Age” and earlier in the Quaternary. [Copyright &y& Elsevier]

The steep outlet glaciers of Jostedalsbreen, western Norway, are good examples of sensitively reacting maritime mountain glaciers. Their changes in length, frontal position and lower tongue's morphology during the past 20 years have been well documented. At first they experienced a strong frontal advance. After AD 2000 glacier behaviour was dominated by a strong frontal retreat, in some cases causing a separation of the lowermost glacier tongue. In this paper, the glacier length changes are presented both visually and numerically, supplemented by mass balance and meteorological data. The glacier behaviour is interpreted and its causes are discussed. Whereas the factors controlling the advance during the 1990s seem clear, the interpretation of the most recent retreat still leaves some uncertainties. The actual glacier front behaviour cannot fully be related to the mass balance data. Terminus response times and relations between individual mass balance and meteorological parameters have changed. Some hypotheses are given, including disturbance of the 'normal' mass transfer and dynamical response of the glacier front because of excessive ablation on the lowermost glacier tongues and summer back melting. These findings underline the sensitivity of maritime glaciers to climate changes. The empirical findings need to be taken into account in the interpretation of recent glacier length changes and their future modelling. [ABSTRACT FROM AUTHOR]

This paper reviews the evolution of video quality measurement techniques and their current state of the art. We start with subjective experiments and then discuss the various types of objective metrics and their uses. We also introduce V-Factor, a "hybrid" metric using both transport- and bitstream information. Finally, we summarize the main standardization activities, such as the work of the Video Quality Experts Group (VQEG), and we take a look at emerging trends in quality measurement, including image preference, visual attention, and audiovisual quality. [ABSTRACT FROM AUTHOR]

Abstract: Nitric oxide (NO) is an important mediator in ischemia–reperfusion injury during human orthotopic liver transplantation (OLT). The perioperative kinetics of nitrite/nitrate plasma levels in 25 patients undergoing uncomplicated OLT were studied. A uniform pattern with significant increases of nitrite/nitrate levels immediately after reperfusion was seen in all patients, followed by a decrease to pretransplant levels within 24h. Peak levels 30min after reperfusion were correlated to the indocyanine green plasma disappearance rate (PDRICG), suggesting an association of early released NO with graft perfusion in OLT. [Copyright &y& Elsevier]

Abstract: RhoGTPases, which are activated by specific guanine nucleotide exchange factors (GEFs), play pivotal roles in several cellular functions. We identified a new RhoGEF (GrinchGEF) containing the typical Dbl homology domain, a putative WD40-like domain, and two predicted transmembrane helices. In contrast to most other RhoGEFs, it exhibits no sequence similarities to known pleckstrin homology domains. GrinchGEF mRNA was highly abundant in skeletal muscle and pancreas. Despite the predicted transmembrane domains, subcellular localization studies revealed a cytosolic distribution. In vitro, GrinchGEF induced the GDP/GTP exchange at RhoA, but not at Rac1 or Cdc42. In intact cells, GrinchGEF induced specifically Rho activation and enhanced RhoA–C-specific downstream effects. [Copyright &y& Elsevier]

Abstract: An understanding of T cell responses that are crucial for control of Mycobacterium tuberculosis (MTB) has major implications for the development of immune-based interventions. We studied the frequency of purified protein derivative (PPD)-specific CD3+ cells expressing interleukin-2 (IL)-2, gamma interferon (IFN)-γ, tumor necrosis factor (TNF)-α and IL-10 in HIV-negative pulmonary tuberculosis patients (TB, n =30) as well as in healthy individuals (controls, n =21) from Central Africa. Increased frequencies of PPD-stimulated CD3+ cells expressing IL-2, IFN-γ, and TNF-α in TB were seen when compared with frequencies of controls. The presence of type 1 cytokine biased responses in TB patients was supported by a shift in the distribution pattern of cytokine expression from exclusively IL-2 or TNF-α expression seen in controls towards an increased frequency of IFN-γ/IL-2 or IFN-γ/TNF-α co-expression in TB. Higher levels of PPD-induced IFN-γ in the supernatants from TB patients than from controls were found, which correlated with its intracellular expression. PPD was a weak inducer of IL-10 in T cells and insufficient in promoting cytokine production in TCRγδ+CD3+ cells. Non-specific stimulation with PMA and ionomycin revealed increased frequencies of CD4+ cells expressing IFN-γ in controls, while expression of IL-2, IL-4, IL-10, IL-13, and TNF-α was not different. Non-specific cytokine responses of TCRγδ+CD3+ cells were similar in all groups. Pulmonary TB in Central Africa is associated with enhanced expression and secretion of specifically induced cytokines that are frequently implicated in host defense against MTB. [Copyright &y& Elsevier]

Lichenometric dating studies using the yellow-green Rhizocarpon subgenus at the Eugenie, Hooker, Mueller and Tasman Glaciers in Mt Cook National Park, Southern Alps, New Zealand, reveal a 'Little Ice Age' maximum during the mid-eighteenth century (around AD 1725–1740). Lichenometric dating curves, constructed for Mueller Glacier in a preliminary study, were modified using local control points at the other glaciers. Modification was necessary because of variations in local ecological conditions. The 'Little Ice Age' chronology is similar for three out of the four glaciers studied. All except Tasman Glacier underwent a major glacier front oscillation directly following the 'Little Ice Age' maximum. After a slow but constant retreat during the second half of the eighteenth and the first half of the nineteenth centuries, the glaciers experienced major readvances during the second half of the nineteenthcentury (around AD 1860 and 1890/95), and during the early decades of the twentieth century. Tasman Glacier, as the exception, returned to its 'Little Ice Age' maximum frontal position during the late nineteenthcentury, overtopping pre-existing 'Little Ice Age' moraines, and therefore preventing detailed dating of these moraines. Differences in dating from previous lichenometric studies may be due to the different methods used. [ABSTRACT FROM AUTHOR]

In cerebral malaria (CM), microvascular activation accompanies blood–brain barrier dysfunction which in turn represents the pathophysiological basis of neurological impairments in affected patients. To dissect the molecular basis of this process, we analyzed localization of proangiogenic vascular endothelial growth factor (VEGF), its receptor vascular endothelial growth factor receptor-1 (VEGFR-1, Flt-1), of downstream VEGF effectors matrix-metalloproteinase-1 (MMP-1) and connective tissue growth factor (CTGF), and of VEGF-interacting antiangiogenic thrombospondin-1 and -independent angiostatin in brains of patients who died with CM and controls by immunohistochemistry and Western blotting experiments.Most prominently, we detected more VEGF+ astrocytes in CM patients and deposition of Flt-1 in Du¨rck's granulomas. MMP-1 and thrombospondin-1 accumulated in macrophages/microglial cells in Du¨rck's granulomas. In one CM patient, massive amounts of CTGF were detected as perivascular paracellular deposits. Angiostatin was observed in the serum of 2/7 control but in no CM patients.These data demonstrate the activation of the proangiogenic VEGF signaling cascade in patients with CM, probably reflecting compensatory mechanisms of general and focal brain hypoxia observed in these patients. [Copyright &y& Elsevier]

New results concerning the dating of 'Little Ice Age' glacier variations at Svartisen and Okstindan, northern Norway, are presented. Measurements of lichens of the Rhizocarpon subgenus on gravestones are used to construct several local sets of lichenometric dating curves. These are partly 'adjusted' in relation to well-established lichenometric dating curves from southern Norway. The 'Little Ice Age' maximum at Svartisen and Okstindan is thereby dated to the mid-eighteenth century (i.e., in agreement with southern Norway). Previously suggested earlier 'Little Ice Age' advances are demonstrated to have resulted from an underestimation of the growth rates of the Rhizocarpon subgenus. Synchroneity of 'Little Ice Age' maxima in southern Norway and at Svartisen and Okstindan suggest that a north-south migration of latitudinal depressional tracks can be excluded as the main forcing factor. As an alternative, an increased SE-NW trend of moist airflow in winter parallel to the coast of Norway is suggested as the main forcing factor with recent glacier dynamics in response to recent climatic fluctuations supporting this hypothesis. [ABSTRACT FROM AUTHOR]

Presents a perceptual model for hiding a spread-spectrum watermark of variable amplitude and density in an image. Significance and uses of digital watermarking; Information on masking as a method of hiding watermarks in an image; Schemes on how to put a watermark in an image.

ABSTRACT. Owing to increased winter balances especially since AD 1988/89, almost all valley outlet glaciers of Jostedalsbreen in western Norway are experiencing the largest advance since that of the early 18th century, the regional "Little Ice Age" maximum. Brigsdalsbreen advanced 441 m between 1987 and 1997. By the end of this period, the glacier had reached the outlet of the proglacial lake Brigsdalsvatnet, ploughing into unfrozen, fine-grained, water-soaked glaciolimnic sediments from the lake bottom and forming frontal moraines. These moraines are characterised by a lack of internal structures and preferred fabric. Owing to the strong advance, the moraine morphology is constantly changing, leaving only temporary moraine ridges. Observations made along the glacier front suggest that the formation of these moraines can best be described as "bulldozed moraines", since the term push moraine, commonly associated with advancing glaciers, should be restricted to permafrost environments. Different processes involved in moraine formation at frontal and lateral glacier margins result from variations in proglacial sediment properties, microrelief and glacier dynamics. Among these processes, large boulders left in the proglacial areas are pushed forward, forming pressure ridges on the distal side. Some of the largest boulders (c. 80-120 m[sup 3]) are overturned or rotated by the glacier. [ABSTRACT FROM AUTHOR]

Measurements with an electronic Schmidt-hammer (RockSchmidt) were conducted on 23 sites of sorted stripes (periglacial patterned ground) on Juvflye, Jotunheimen (central South Norway). All were located above the current lower limit of alpine permafrost. Performing Schmidt-hammer exposure-age dating (SHD) based on application of a new local age-calibration equation for R Rock -values yielded SHD-ages between 7975 ± 370 and 6660 ± 355 years ago, which are closely comparable to results obtained previously from sorted circles at the same location. The age estimates are interpreted as 'composite' ages indicative of upfreezing of boulders, lateral sorting, and subsequent stabilisation. Formation of patterned ground essentially ceased with the onset of the regional Holocene Thermal Maximum (HTM). Neither sorted stripe sites at higher altitude, continuously underlain by permafrost during the entire Holocene, nor those at lower altitudes affected by re-aggradation of permafrost in the late Holocene show signs of significant recent morphodynamic activity. Likely explanations for early- to mid-Holocene stabilisation include (1) substantial changes of soil moisture conditions and related thermodynamics within the active layer affecting frost action, (2) loss of fine-grained substrate matrix from the coarse stripes and hence reduced frost susceptibility, and (3) exhaustion of supply of boulders from the fines-dominated areas. Whereas the sorted stripe data set as a whole did not reproduce the altitudinal gradient characteristic of sorted circles on Juvflye, the strength of the relationship between sorted stripe mean R Rock -values and altitude increased with declining slope gradient. Although interpretation of SHD-ages for patterned ground remains challenging, this successful application of the electronic Schmidt-hammer, with its increased efficiency and technical improvements over the mechanical Schmidt-hammer, offers considerable potential for future SHD-studies in both morphodynamic and palaeoclimatic contexts. • Successful application of the electronic Schmidt-hammer (RockSchmidt) for SHD • Stabilisation of sorted stripes around onset of regional Holocene Thermal Maximum • Good correspondence of ages for sorted stripes with previously studied sorted circles • Indication of relationship between sorted stripe age and altitude on low angle slopes • No substantial late Holocene morphodynamic activity despite underlying permafrost [ABSTRACT FROM AUTHOR]

Rock avalanches onto glaciers are rare in Norway. Here, we examine a rock avalanche that spread onto the regenerated Brenndalsbreen, an outlet glacier from Jostedalsbreen ice cap. The rock avalanche is intriguing in that limited information exists with respect to the exact time of failure, location of detachment area, and preparatory and triggering processes. Based on an analysis of ice stratigraphy and photographic documentation, we assess that the event happened between mid-March and June 4, 2010. A potential triggering factor could have been heavy snow and rainfall combined with above freezing air temperatures on March 18–19, 2010. We use digital terrain models to determine that the detachment area is at an almost vertical rock slope in a narrow gorge above Lower Brenndalsbreen. The deposit volume is estimated to 0.130 ± 0.065 Mm3, and the H/L ratio and fahrböschung are 0.45 and 24°, respectively. We apply a Voellmy flow model to confirm the detachment location and volume estimate by producing realistic runout lengths. Although glacial debuttressing may have been a likely preparatory process, the detachment area was exposed for 45–70 years before the rock avalanche occurred. The supraglacial rock avalanche debris was separated into two branches with a distinct melt-out line across the glacier. The debris reached the glacier front in 2019 and 2020, where it started being deposited proglacially while Lower Brenndalsbreen kept receding. The 2010 Brenndalsbreen rock avalanche may not be a unique event, as deposits constituting evidence of an old rock avalanche are currently melting out at the glacier front. [ABSTRACT FROM AUTHOR]

The high-altitudinal plateaus of Jotunheimen in central South Norway, the mountain region home of Norway's highest summits, create a unique and diverse natural environment. The specific gross morphology of Jotunheimen facilitates the occurrence of a variety of periglacial landforms ranging considerably in both dimension and age. The regional distribution of permafrost is one of the major controlling factors for the altitudinal distribution of these periglacial landforms. The largest individual features of patterned ground, undisputed the regionally most dominant periglacial landforms, are situated on terrain currently underlain by permafrost. They visually appear to be quite relict, despite the occurrence of permafrost, and the exact timing of their formation remains unknown. This example points to additional factors significantly influencing the periglacial landform assemblage, like topography, ground moisture availability, and the local deglaciation history. The lack of a regional overview regarding periglacial landforms in Jotunheimen exacerbates the need for a profound investigation of their altitudinal zonation and potential causal links to climate, permafrost, (de-)glaciation, and other factors.The compilation of a regional overview based on aerial imagery and a literature review aims, therefore, to reveal further insight into the controlling factors for and mechanisms of periglacial landform development in Jotunheimen. This shall be achieved by creating an altitudinal zonation for periglacial features and highlighting causal links between their spatial/altitudinal distribution and possible influencing factors. In an outlook to future studies this attempt may also provide more detailed information on the regional basal properties of the former Scandinavian ice sheet, the regional/local deglaciation patterns for the Jotunheimen region, and about the exact chronology of formation of the periglacial landforms studied. [ABSTRACT FROM AUTHOR]

Feedbacks between geomorphic and vegetation dynamics create spatial patterns of vegetation, soils and landforms in biogeomorphic ecosystems and determine their structure and functioning. In glacier forelands, it was shown that these biogeomorphic feedbacks link paraglacial adjustment and vegetation succession and control landscape development and stability over space and time (Eichel et al. 2016, 2018). However, the role of biogeomorphic feedbacks also depends on the environmental setting of the biogeomorphic ecosystem, e.g. on its geomorphic disturbance regime and the occurrence of ecosystem engineer species. In glacier forelands, previous research has primarily focussed on the European Alps and different environmental settings have not been comprehensively investigated yet. Here, we explore the coupling between paraglacial adjustment and vegetation succession in the Southern Alps, New Zealand. In comparison to previously investigated glacier forelands in the European Alps, the selected foreland of Mueller Glacier is characterized by an extraordinarily high geomorphic activity due to high amounts of precipitation (~4000 mm yr-1) and frequent storm events, a mostly continuous glacier wastage since the Little Ice Age maximum (1730/1735) and a mostly endemic flora. Our objectives are to (i) analyse linkages between paraglacial adjustment and vegetation succession in space and time, (ii) identify potential ecosystem engineer species, and (iii) determine the extent of biogeomorphic feedbacks and their role for landscape development and stability. To assess biogeomorphic feedbacks in space and time, we conducted a vegetation and environmental plot survey (55 plots) and created geomorphic and vegetation maps from field mapping, a UAV survey and deep learning algorithms (convolutional neural networks). Finally, we linked geomorphic and ecologic properties to the glacial chronology (Winkler, 2018). Analyses of plot data, geomorphic and vegetation maps show that (i) paraglacial adjustment and vegetation succession are mostly independent from terrain age but depend on material properties and are interlinked in a biogeomorphic succession. (ii) Once geomorphic activity decreases, stable patches are created by the prostate/low growing shrub species Muehlenbeckia axillaris and Coriaria spp., which are therefore potential ecosystem engineer species that promote slope stabilization and facilitate further vegetation succession. (iii) Biogeomorphic feedbacks mostly occur on a local (patch) scale, large areas of the foreland are either dominated by unvegetated highly active slopes or dense late-successional vegetation. Yet, our results indicate that vegetation colonization and ecosystem engineering are important controls for landscape stabilization, which can take substantially longer than in the European Alps. In conclusion, our study shows that similar biogeomorphic feedbacks link paraglacial adjustment and vegetation succession in the European and the Southern Alps, but feedback strength and extent depend on environmental setting.ReferencesEichel J, Corenblit D, Dikau R (2016) Conditions for feedbacks between geomorphic and vegetation dynamics on lateral moraine slopes: a biogeomorphic feedback window. Earth Surf Process Landforms 41:406–419. doi:10.1002/esp.3859Eichel J, Draebing D, Meyer N (2018) From active to stable: paraglacial transition of Alpine lateral moraine slopes. Land Degradation & Development 29:4158–4172. doi:10.1002/ldr.3140Winkler S (2018) Investigating Holocene mountain glaciations: a plea for the supremacy of glacial geomorphology when reconstructing glacier chronologies. Erdkunde 72:215–234. doi:10.3112/erdkunde.2018.03.04 [ABSTRACT FROM AUTHOR]

Research on mountain glaciations has a long history and in the light of current global change, they are increasingly recognised as highly important palaeoclimatic archives for the immediate and more distant geological past. One of the most important leaps forward with the investigation of mountain glaciations during the past 2 decades was substantial improvement achieved within the field of numerical age dating techniques, in particular progress of surface exposure dating using cosmogenic radionuclides (CRN). This development has definitely given the entire research field new momentum. Unfortunately, this methodological progress is in many cases not matched by the recommended necessary level of precautions regarding the interpretative steps with the reconstruction of Holocene glacier chronologies. Improved precision and accuracy with numerical dating techniques comes often with an increasing lack of attention with the geomorphological analysis of the dated landforms. With recent studies it has subsequently become more popular to outline moraines primarily based on individual CRN boulder age clusters without detailed geomorphological mapping or examination. Such an attempt has also been conducted on Holocene glacier forelands in Aoraki/Mt.Cook National Park where a substantial number of CRN boulders ages have been employed to identify and label numerous "moraines". Subsequently, arithmetic means of CRN ages for these apparent "moraines" were linked to individual glacier advances and palaeoclimatically interpreted accordingly. A sound geomorphological analysis of the studied glacier foreland does, however, reveal that this procedure is actually erroneous. Among the problems identified are (a) inclusion of hugely overprinted moraine remnants that lack proper characterisation, (b) wrong subdivision of moraine segments belonging to one defined individual moraines, and (c) mismatching of apparent CRN ages for moraine segments that morphologically need to correspond for any meaningful reconstruction of former marginal positions. A revision of this particular glacier chronology provides major implications for any subsequent palaeoclimatic interpretation as the number of reliably documented neoglacial events decrease from 9 to 5.The value of geomorphological analysis in the context of investigating mountain glaciations is, however, not primarily restricted to chronological approaches. It may also provide assistance with the conceptual context for mechanisms of deglaciation patterns or long-term landscape evolution. In the upper Waimakariri River catchment following a Late Glacial readvance dated to c. 17.5 ka ago, a lake dammed by the related moraine system and debris-covered dead ice should have existed for many centuries before it subsequently drained. That lake would naturally have influenced both the immediate deglaciation mechanism and landform evolution post-LGM. Despite introduced during the 1950s, the concept of this particular palaeo-lake has never been exposed to any detailed geomorphological analysis yet. Whereas the existence of a post-LGM palaeo-lake itself remains out of question, the proposed link to glacier retreat following a Late Glacial re-advance is unrealistic in light of a logical time sequence for individual elements of the local landform assemblage. The lake needs to be younger and postdate Deglaciation in this section of the Waimakariri River.Summarising, detailed geomorphological analysis is indispensable with any attempt to investigate mountain glaciations. [ABSTRACT FROM AUTHOR]

Growth and decay of Quaternary glaciers and ice sheets had fundamental implications for environmental changes worldwide. The chronology of the last deglaciation following the Last Glacial Maximum (LGM, 26.5-20 ka) and its ice marginal positions in Norway are generally perceived as being well constrained. The detailed vertical extent in Norway remains, however, still uncertain over large areas. The knowledge of the vertical dimension of the LGM ice sheet can provide crucial information on palaeo-environmental factors like sea-level changes, atmospheric and oceanic circulation, (de-)glaciation patterns, which are important variables for climate modelling. The interpretation of differently weathered bedrock in mountain areas affected by Quaternary glaciation can be crucial for determining ice-sheet behaviour and thickness. Based on 10Be terrestrial cosmogenic nuclide dating and Schmidt-hammer exposure age-dating (SHD) performed in eastern and western South Norway, we provide new insights in (de)glaciation patterns, landform evolution and estimate ice thickness during and following the LGM. We present the first numerical dates from the western study area showing that deglaciation started ~4 ka earlier and ice sheet downwasting lasted longer than assumed. SHD ages obtained from periglacial and related landforms (e.g. rock-slope failures, pronival ramparts) in this area point to their stabilization during the Holocene Thermal Maximum (~8-5 ka). The rock-slope failures investigated did not occur shortly after local deglaciation, it appears that they cluster around warm periods due to climate-driven factors, like decreasing permafrost depth or increasing cleft-water pressure. Exposed bedrock at the summit in the eastern study area yields a 10Be exposure age predating the Late Weichselian Maximum of 43.7 ± 1.9 ka, possibly indicating ice free areas during the LGM. Instead of the inferred ice coverage at ~15 ka, our SHD ages from blockfields suggest ice-free and severe periglacial conditions occurred earlier. Landforms above 1450 m a.s.l. (e.g. sorted stone polygons, blockstreams) do not show any form of reactivation during cold periods within the Late Glacial or the Holocene. Our results have wider implications on the glaciation history of the area. The results point to a more complex ice sheet behaviour than previously expected. Therefore, we suggest a more complex and topographically controlled configuration of the LGM ice sheet in relation to previous reconstructions. [ABSTRACT FROM AUTHOR]

Surface exposure–age dating was applied to rock surfaces associated with ice‐marginal moraines at elevations of ~1520–1780 m a.s.l. on the slopes of Galdhøpiggen and Glittertinden, the two highest mountains in Scandinavia located in the Jotunheimen mountains of central southern Norway. This is important for understanding the pattern and timing of wastage of the Scandinavian Ice Sheet at the Younger Dryas–Holocene transition. Cosmogenic exposure dating (here 10Be dating) of boulders from the moraine ridges yielded overall mean ages (corrected for glacio‐isostatic uplift, surface erosion and snow shielding) of ~11.6 ka from Galdhøpiggen and ~11.2 ka from Glittertinden. Similar 10Be ages were also obtained from additionally collected proximal and distal erratic boulders and bedrock samples. These enabled age calibration of Schmidt‐hammer R‐values and independent Schmidt‐hammer exposure‐age dating (SHD) of the moraine ridges, which yielded comparable mean SHD ages of ~10.8 and ~10.6 ka from the Galdhøpiggen and Glittertinden sites, respectively. Taking account of the age resolution and other limitations of both dating techniques, the results suggest that the two sets of moraines have approximately the same age but that neither technique can distinguish unambiguously between moraine formation in the late Younger Dryas or Early Holocene. Together with features of moraine‐ridge morphology and estimates of equilibrium‐line altitude depression of ~360–575 m (corrected for land uplift), the results imply moraine formation during short‐lived re‐advances of active glaciers, at least the lower reaches of which were warm‐based. It is concluded that the local glaciers remained active and advanced during deglaciation either very late in the Younger Dryas or very early in the Holocene, possibly in response to the Preboreal Oscillation at ~11.4 ka. The study supports the concept of a thin Younger Dryas ice sheet and places time constraints on the timing of final deglaciation in southern Norway. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented regarding the study on Alu repeat-induced deletions in chronic granulomatous disease (GGD).

In southern Norway, early-Holocene climatically induced glacier expansion episodes have been recognised at ~11.1, 10.5, 10.2, 9.7 and 8.2 ka, but the only convincingly dated, single- or doubleridged moraines are those associated with the regional Erdalen Event (i.e., ~10.2-9.7 ka). We applied three numerical-age dating techniques to sequences of up to five moraine ridges deposited by the former Sognefjell ice cap and by Styggedalsbreen, a large cirque glacier in the nearby Hurrungane massif. On inner and outer ridges and relict patterned ground proximal to the moraines, six 10Be and eight Schmidt hammer (SHD) surface exposure ages were obtained. Thirteen radiocarbon dates were obtained from stream-bank mire sediments proximal to the Sognefjell moraines. The basal date is similar to those from cores in an adjacent lake indicating disappearance of the Sognefjell ice-cap immediately following the Erdalen Event. Three of four SHD results, and one of three 10Be surface exposure ages from the Sognefjell moraines support this. At Styggedalsbreen, two of three 10Be surface exposure ages lie between the 8.2 ka (Finse) and Erdalen Event, though 1 s dating uncertainties only overlap with the former: the third is clearly affected by cosmogenic nuclide inheritance. SHD results also suggest the younger event, but this is attributed to lithological differences between the Schmidt-hammer calibration site and the sampled moraine boulders. Considering the chronological evidence as a whole, supported by equilibrium-line altitude (ELA) calculations for Styggedalsbreen, we conclude that the moraines were formed by up to five short but distinct fluctuations of these ice masses during the Erdalen Event. This indicates more complex decadal- to centennial-scale glacier variations and climatic perturbations within the Erdalen Event than previously recognised. The implied exceptional glaciological sensitivity to climate variability is attributed to local topographic factors causing glacial fluctuations in response to relatively small ELA changes. [ABSTRACT FROM AUTHOR]

Schmidt-hammer exposure-age dating (SHD) of boulders on cryoplanation terrace treads and associated bedrock cliff faces revealed Holocene ages ranging from 0 ± 825 to 8890 ± 1185 yr. The cliffs were significantly younger than the inner treads, which tended to be younger than the outer treads. Radiocarbon dates from the regolith of 3854 to 4821 cal yr BP (2σ range) indicated maximum rates of cliff recession of ~0.1 mm/yr, which suggests the onset of terrace formation before the last glacial maximum. Age, angularity, and size of clasts, together with planation across bedrock structures and the seepage of groundwater from the cliff foot, all support a process-based conceptual model of cryoplanation terrace development in which frost weathering leads to parallel cliff recession and, hence, terrace extension. The availability of groundwater during autumn freezeback is viewed as critical for frost wedging and/or the growth of segregation ice during prolonged winter frost penetration. Permafrost promotes cryoplanation by providing an impermeable frost table beneath the active layer, focusing groundwater flow, and supplying water for sediment transport by solifluction across the tread. Snow beds are considered an effect rather than a cause of cryoplanation terraces, and cryoplanation is seen as distinct from nivation. [ABSTRACT FROM AUTHOR]

Reports on cases of ventriculoatrial shunt infection. Medical histories of the patients; Results of physical and laboratory examinations; Details of the treatment rendered to the patients.