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Recent low summer sea ice extent in the Weddell Sea raises questions about the contributions of dynamic and thermodynamic atmospheric and oceanic energy fluxes. The roles of snow, superimposed ice, and snow ice are particularly intriguing, as they are sensitive indicators of changes in atmospheric forcing and as they could trigger snow–albedo feedbacks that could accelerate ice melt. Here we present snow depth data and ice core observations of superimposed ice and snow ice collected in the northwestern Weddell Sea in late austral summer 2019, supplemented by airborne ice thickness measurements. Texture, salinity, and oxygen isotope analyses showed mean thicknesses of superimposed and snow ice of 0.11±0.11 and 0.22±0.22 m, respectively, or 3 % to 54 % of total ice thickness. Mean snow depths ranged between 0.46±0.29 m in the south to 0.05±0.06 m in the north, with mean and modal total ice thicknesses of 4.12±1.87 to 1.62±1.05 m and 3.9 to 0.9 m, respectively. These snow and ice properties are similar to results from previous studies, suggesting that the ice's summer surface energy balance and related seasonal transition of snow properties have changed little in past decades. This is supported by our additional analyses of the summer energy balance using atmospheric reanalysis data and by melt onset observations from satellite scatterometry showing few recent changes. [ABSTRACT FROM AUTHOR]

The light-driven formation and cleavage of cyclobutane structural motifs resulting from [2 + 2]-pericyclic reactions, as found in thymine and coumarin-type systems, is an important and intensively studied photochemical reaction. Various applications are reported utilizing these systems, among others, in cross-linked polymers, light-triggered drug release, or other technical applications. Herein coumarin is most frequently used as the photoactive group. Quite often, a poor quantum yield for dimerization and cyclobutane-cleavage and a lack of reversibility are described. In this work, we present the identification of a heterogeneous pathway of dimer cleavage found in a rarely studied coumarin analog molecule, the N-methyl-quinolinone (NMQ). The monomer was irradiated in a tube flow-reactor and the reaction process was monitored using online HPLC measurements. We found the formation of a pseudo-equilibrium between monomeric and dimeric NMQ and a continuous rise of a side product via oxidative dimer splitting and proton elimination which was identified as 3,3'-bis-NMQ. Oxidative conversion by singlet oxygen was identified to be the cause of this non-conventional cyclobutane cleavage. The addition of antioxidants suppressing singlet oxygen enables achieving a 100% photochemical conversion from NMQ to the anti-head-to-head-NMQ-dimer. Using dissolved oxygen upon light activation to singlet oxygen limits the reversibility of the photochemical [2 + 2]-cycloaddition and cycloreversion of NMQ and most likely comparable systems. Based on these findings, the development of highly efficient cycloaddition–cycloreversion systems should be enabled. [ABSTRACT FROM AUTHOR]

An unusual, large, latent-heat polynya opened and then closed by freezing and convergence north of Greenland's coast in late winter 2018. The closing presented a natural but well-constrained full-scale ice deformation experiment. We observed the closing of and deformation within the polynya with satellite synthetic-aperture radar (SAR) imagery and measured the accumulated effects of dynamic and thermodynamic ice growth with an airborne electromagnetic (AEM) ice thickness survey 1 month after the closing began. During that time, strong ice convergence decreased the area of the refrozen polynya by a factor of 2.5. The AEM survey showed mean and modal thicknesses of the 1-month-old ice of 1.96 ± 1.5 m and 1.1 m, respectively. We show that this is in close agreement with modeled thermodynamic growth and with the dynamic thickening expected from the polynya area decrease during that time. We found significant differences in the shapes of ice thickness distributions (ITDs) in different regions of the refrozen polynya. These closely corresponded to different deformation histories of the surveyed ice that we reconstructed from Lagrangian ice drift trajectories in reverse chronological order. We constructed the ice drift trajectories from regularly gridded, high-resolution drift fields calculated from SAR imagery and extracted deformation derived from the drift fields along the trajectories. Results show a linear proportionality between convergence and thickness change that agrees well with the ice thickness redistribution theory. We found a proportionality between the e folding of the ITDs' tails and the total deformation experienced by the ice. Lastly, we developed a simple, volume-conserving model to derive dynamic ice thickness change from the combination of Lagrangian trajectories and high-resolution SAR drift and deformation fields. The model has a spatial resolution of 1.4 km and reconstructs thickness profiles in reasonable agreement with the AEM observations. The modeled ITD resembles the main characteristics of the observed ITD, including mode, e folding, and full width at half maximum. Thus, we demonstrate that high-resolution SAR deformation observations are capable of producing realistic ice thickness distributions. [ABSTRACT FROM AUTHOR]

Basal melting of ice shelves can result in the outflow of supercooled ice shelf water, which can lead to the formation of a sub-ice platelet layer (SIPL) below adjacent sea ice. McMurdo Sound, located in the southern Ross Sea, Antarctica, is well known for the occurrence of a SIPL linked to ice shelf water outflow from under the McMurdo Ice Shelf. Airborne, single-frequency, frequency-domain electromagnetic induction (AEM) surveys were performed in November of 2009, 2011, 2013, 2016, and 2017 to map the thickness and spatial distribution of the landfast sea ice and underlying porous SIPL. We developed a simple method to retrieve the thickness of the consolidated ice and SIPL from the EM in-phase and quadrature components, supported by EM forward modelling and calibrated and validated by drill-hole measurements. Linear regression of EM in-phase measurements of apparent SIPL thickness and drill-hole measurements of "true" SIPL thickness yields a scaling factor of 0.3 to 0.4 and rms error of 0.47 m. EM forward modelling suggests that this corresponds to SIPL conductivities between 900 and 1800 mSm-1 , with associated SIPL solid fractions between 0.09 and 0.47. The AEM surveys showed the spatial distribution and thickness of the SIPL well, with SIPL thicknesses of up to 8 m near the ice shelf front. They indicate interannual SIPL thickness variability of up to 2 m. In addition, they reveal high-resolution spatial information about the small-scale SIPL thickness variability and indicate the presence of persistent peaks in SIPL thickness that may be linked to the geometry of the outflow from under the ice shelf. [ABSTRACT FROM AUTHOR]

Political redistricting is the redrawing of electoral district boundaries. It is normally undertaken to reflect population changes. The process can be abused, in what is called gerrymandering, to favor one party or interest group over another, resulting thereby in broadly undemocratic outcomes that misrepresent the views of the voters. Gerrymandering is especially vexing in the United States. This paper introduces an algorithm, with an implementation, for creating districting plans (whether for political redistricting or for other districting applications). The algorithm, Seed-Fill-Shift-Repair (SFSR), is demonstrated for Congressional redistricting in American states. SFSR is able to create thousands of valid redistricting plans, which may then be used as points of departure for public deliberation regarding how best to redistrict a given polity. The main objectives of this paper are: (i) to present SFSR in a broadly accessible form, including code that implements it and test data, so that it may be used for both civic deliberations by the public and for research purposes. (ii) to make the case for what SFSR essays to do, which is to approach redistricting, and districting generally, from a constraint satisfaction perspective and from the perspective of producing a plurality of feasible solutions that may then serve in subsequent deliberations. To further these goals, we make the code publicly available. The paper presents, for illustration purposes, a corpus of 11,206 valid redistricting plans for the Commonwealth of Pennsylvania (produced by SFSR), using the 2017 American Community Survey, along with descriptive statistics. Also, the paper presents 1,000 plans for each of the states of Arizona, Michigan, North Carolina, Pennsylvania, and Wisconsin, using the 2018 American Community Survey, along with descriptive statistics on these plans and the computations involved in their creation. [ABSTRACT FROM AUTHOR]

During the 2018 Multidisciplinary Arctic Program‐Last Ice in the Lincoln Sea, we sampled 45 multiyear ice (MYI) and 34 first‐year ice (FYI) cores, combined with snow depth, ice thickness, and transmittance surveys from adjacent level FYI and undeformed MYI. FYI sites show a decoupling between bottom‐ice chlorophyll a (chl a) and snow depth; however, MYI showed a significant correlation between ice‐algal chl a biomass and snow depth. Topographic control of the snow cover resulted in greater spatiotemporal variability of the snow over the level FYI, and consequently transmittance, compared to MYI with an undulating surface. The coupled patterns of snow depth, transmittance, and chl a indicate that MYI provides an environment with more stable light conditions for ice algal growth. The importance of sea ice surface topography for ice algal habitat underpins the potential ecological changes associated with projected increased ice dynamics and deformation. Plain Language Summary: This study presents first results from the 2018 Multidisciplinary Arctic Program‐Last Ice, the most intensive ecologically focused research project ever conducted within the so‐called "Last Ice Area." This region is of key importance because it is the only place in the Arctic expected to retain summer sea ice by the year 2050. Continued changes to the sea ice environment will have ecological consequences because sea ice is an important habitat for many animals from microscopic ice algae, the base of the food chain, to seals and polar bears. Since the older ice is being replaced by younger ice, we compared older ice to younger ice in order to provide a glimpse into the future. We found that the older ice has a more stable light environment for ice algae due to snow depth patterns associated with surface topography. This can mean that as the older ice is replaced by newer ice, the availability of ice algae as a food source may become more unpredictable. The importance of surface topography for ice algae indicates that the projected acceleration in sea ice drift and increased ridging due to thinner ice will likely have an impact on key sea ice habitat properties. Key Points: Spatiotemporal changes in snow cover and transmittance were observed for FYI but remained stable for MYI due to differences in topographyThe spatial distribution of bottom‐ice chl a biomass was coupled to snow depth and transmittance in MYI but decoupled in FYIA projected shift to a more dynamic and deformed sea ice cover is likely to be a key driver of ice‐algal habitat variability in the future [ABSTRACT FROM AUTHOR]

The timing and intensity of snowmelt processes on sea ice are key drivers determining the seasonal sea-ice energy and mass budgets. In the Arctic, satellite passive microwave and radar observations have revealed a trend towards an earlier snowmelt onset during the last decades, which is an important aspect of Arctic amplification and sea-ice decline. Around Antarctica, snowmelt on perennial ice is weak and very different than in the Arctic, with most snow surviving the summer. Here we compile time series of snowmelt onset dates on seasonal and perennial Antarctic sea ice from 1992 to 2014/15 using active microwave observations from the European Space Agency's (ESA) European Remote Sensing (ERS) 1 and 2 missions (ERS-1 and ERS-2), Quick Scatterometer (QSCAT), and Advanced Scatterometer (ASCAT) radar scatterometers. We define two snowmelt transition stages: a weak backscatter rise, indicating the initial warming and destructive metamorphism of the snowpack (pre-melt), followed by a rapid backscatter rise, indicating the onset of thaw–freeze cycles (snowmelt). Results show large interannual variability, with an average pre-melt onset date of 29 November and melt onset of 10 December, respectively, on perennial ice, without any significant trends over the study period, consistent with the small trends of Antarctic sea-ice extent. There was a latitudinal gradient from early snowmelt onsets in mid-November in the northern Weddell Sea to late (end of December) or even absent snowmelt conditions in the southern Weddell Sea. We show that QSCAT Ku-band-derived (13.4 GHz signal frequency) pre-melt and snowmelt onset dates are earlier by 20 and 18 d, respectively, than ERS and ASCAT C-band-derived (5.6 GHz) dates. This offset has been considered when constructing the time series. Snowmelt onset dates from passive microwave observations (37 GHz) are later by 14 and 6 d than those from the scatterometers, respectively. Based on these characteristic differences between melt onset dates observed by different microwave wavelengths, we developed a conceptual model which illustrates how the seasonal evolution of snow temperature profiles may affect different microwave bands with different penetration depths. These suggest that future multi-frequency active and passive microwave satellite missions could be used to resolve melt processes throughout the vertical snow column of thick snow on perennial Antarctic sea ice. [ABSTRACT FROM AUTHOR]

The optimization of complex chemical reaction systems is often a troublesome and time‐consuming process. The application of modern technologies, including automated reactors and analytics, opens the avenue for generating large data sets on chemical reaction processes in a short period of time. In this work, an automated flow reactor is used to present detailed kinetics and mechanistic studies about an amine‐catalyzed Knoevenagel−Michael domino reaction to yield tetrahydrochromene derivatives. High‐performance monoliths as catalyst supports and online coupled HPLC analysis allow for time‐efficient data generation. We show that the two‐step multicomponent domino reaction does not follow the kinetics of consecutive reaction steps proceeding independently from each other. Instead, the starting materials of both individual reactions compete for the active sites on the heterogeneous catalyst, which lowers the rate constants of both steps. This knowledge was used to implement a more efficient experimental setup which increased the turnover numbers of the catalyst, without adjusting common reaction parameters like temperature, reaction time, and concentrations. [ABSTRACT FROM AUTHOR]

In scenarios where allocations are determined by participant’s preferences, Two-Sided Matching is a well-established approach with applications in College Admissions, School Choice, and Mentor-Mentee matching problems. In such a context, participants in the matching have preferences with whom they want to be matched with. This article studies two important concepts in Two-Sided Matching: multiple objectives when finding a solution, and manipulation of preferences by participants. We use real data sets from a Mentor-Mentee program for the evaluation to provide insight on realistic effects and implications of the two concepts. In the first part of the article, we consider the quality of solutions found by different algorithms using a variety of solution criteria. Most current algorithms focus on one criterion (number of participants matched), while not directly taking into account additional objectives. Hence, we evaluate different algorithms, including multi-objective heuristics, and the resulting trade-offs. The evaluation shows that existing algorithms for the considered problem sizes perform similarly well and close to the optimal solution, yet multi-objective heuristics provide the additional benefit of yielding solutions with better quality on multiple criteria. In the second part, we consider the effects of different types of preference manipulation on the participants and the overall solution. Preference manipulation is a concept that is well established in theory, yet its practical effects on the participants and the solution quality are less clear. Hence, we evaluate the effects of three manipulation strategies on the participants and the overall solution quality, and investigate if the effects depend on the used solution algorithm as well. [ABSTRACT FROM AUTHOR]

Corporate bankruptcies often have severe consequences on all stakeholders, from financial stakeholders losing their investment to employees losing their jobs. Yet traditional bankruptcy prediction models typically focus solely on predicting the event of bankruptcy itself, and do not consider the socio-economic consequences of their prediction. Therefore, this study aims to integrate these perspectives into the machine-learning (ML) modeling process to consider different costs caused by bankruptcy. We improve upon existing bankruptcy prediction models by actively taking the social and financial impacts of bankruptcy into account. Specifically, we consider two alternative evaluation metrics: the financial costs of bankruptcy, and the social impact measured using number of lost jobs as proxy. We compare a variety of machine-learning models as well as multivariate discriminant analysis and logistic regression, the latter serving as a benchmark to show the improvements that can be achieved using ML models. We apply the models on a large real-world data set from the Compustat database, containing listed companies in North America for the period from 1985 to 2020, with over 190,000 company-year observations. Our results show that small differences in statistical performance can translate into large differences regarding socio-economic costs, and that the selection of the 'best' performing model crucially depends on the evaluation metric considered. • Bankruptcy prediction models are usually evaluated based on statistical performance. • We introduce the socio-economic costs as alternative performance measures. • We find that the ranking of the models depends on the used performance measure. [ABSTRACT FROM AUTHOR]

This paper uses a model with Directed Technical Change to theoretically analyse observable heterogeneous energy intensity developments. Based on the empirical evidence, we decompose changes in aggregate energy intensity into structural changes in the economy (structural effect) and within-sector energy efficiency improvements (efficiency effect). The relative importance of these effects is deter mined by energy price growth and sectoral productivities that drive the direction of technical change. When research is directed to the labour-intensive sector, the structural effect is the main driver of energy intensity dynamics. In contrast, the efficiency effect dominates energy intensity developments, when research is directed to energy-intensive industries. Increasing energy price generally leads to lower energy intensities and temporal energy price shocks might induce a permanent redirection of innovation activities. We calibrate the model to empirical data and simulate energy intensity developments across countries. The results of our very stylised model are largely consistent with empirical evidence. [ABSTRACT FROM AUTHOR]

Common methods for in-situ determination of porosity of river bed material are time- and effort-consuming. Although mathematical predictors can be used for estimation, they do not adequately represent porosities. The objective of this study was to assess a new approach for the determination of porosity of frozen sediment samples. The method is based on volume determination by applying Structure-from-Motion with Multi View Stereo (SfM-MVS) to estimate a 3D volumetric model based on overlapping imagery. The method was applied on artificial sediment mixtures as well as field samples. In addition, the commonly used water replacement method was applied to determine porosities in comparison with the SfM-MVS method. We examined a range of porosities from 0.16 to 0.46 that are representative of the wide range of porosities found in rivers. SfM-MVS performed well in determining volumes of the sediment samples. A very good correlation ( r  = 0.998, p  < 0.0001) was observed between the SfM-MVS and the water replacement method. Results further show that the water replacement method underestimated total sample volumes. A comparison with several mathematical predictors showed that for non-uniform samples the calculated porosity based on the standard deviation performed better than porosities based on the median grain size. None of the predictors were effective at estimating the porosity of the field samples. [ABSTRACT FROM AUTHOR]

Background: Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease worldwide. The renal phenotype is characterized by progressive cystic enlargement of the kidneys leading to a decline in renal function, hypertension and often end-stage renal disease (ESRD). Supportive care with blood pressure control and management of pain, urinary infections and renal stone disease has, until recently, been the mainstay of treatment. With the recent approval of tolvaptan for use in ADPKD, the disease progression may now be targeted specifically. Algorithms that guide treatment initiation have been proposed but a more pragmatic and patient-individualized approach is often needed to make decisions regarding therapy. It is highly important to identify ADPKD patients with rapidly progressive disease who are likely to benefit most from this treatment and avoid treatment in patients that are unlikely to reach ESRD. Methods and Results: Here we present a series of cases of ADPKD patients in whom therapy with tolvaptan has been considered and report the rationale for the treatment decisions based on available lifestyle, clinical, biochemical, radiological and genetic data. Conclusions: These cases provide a discussion for the use of tolvaptan in ADPKD within the nephrology clinic and allow insights into the practicalities of using this therapy outside of clinical trials. [ABSTRACT FROM AUTHOR]

In cold climate regions, the formation and breakup of river ice is important for river morphology, winter water supply, and riparian and instream ecology as well as for hydraulic engineering. Data on river ice is therefore significant, both to understand river ice processes directly and to assess ice effects on other systems. Ice measurement is complicated due to difficult site access, the inherent complexity of ice formations, and the potential danger involved in carrying out on-ice measurements. Remote sensing methods are therefore highly useful, and data from satellite-based sensors and, increasingly, aerial and terrestrial imagery are currently applied. Access to low cost drone systems with quality cameras and structure from motion software opens up a new possibility for mapping complex ice formations. Through this method, a georeferenced surface model can be built and data on ice thickness, spatial distribution, and volume can be extracted without accessing the ice, and with considerably fewer measurement efforts compared to traditional surveying methods. A methodology applied to ice mapping is outlined here, and examples are shown of how to successfully derive quantitative data on ice processes. [ABSTRACT FROM AUTHOR]

Cardiovascular disease (CVD) is the most common cause of death in the world. Recent studies have shown an association between adrenal insufficiency (AI) and increased cardiovascular risk (CVR). Patients with AI receive glucocorticoid (GC) replacement therapy which can lead to varying levels of blood cortisol. It was shown that these imbalances in blood cortisol may lead to a higher prevalence of coronary heart disease, major adverse coronary events, and increased mortality. GC substitution is essential in the treatment of AI without which the disease has been shown to be fatal. The most frequently used GC formula for replacement therapy is hydrocortisone (HC). There is no uniform opinion on hydrocortisone replacement therapy. Alternative GC such as prednisolone is also in use. Overreplacement of GC may lead to adverse effects including obesity, high blood pressure, and hyperglycaemia. Outcome may vary between primary and secondary AI mainly due to differences in the renin-angiotensin-aldosterone system (RAAS). Furthermore, decreased blood levels of cortisol may lead to a compensatory secretion of inflammatory mediators such as Interleukin-1 (IL-1), Interleukin-6 (IL-6), and/or tumor-necrosis factor (TNF). Physicians and patients should be properly educated about the increased risk of CVD in patients with AI. [ABSTRACT FROM AUTHOR]

In April 2017, we collected unique, extensive in situ data of sea ice and snow thickness. At 10 sampling sites, located under a CryoSat-2 overpass, between Ellesmere Island and 87.1°N mean and modal total ice thicknesses ranged between 2 to 3.4 m and 1.8 to 2.9 m, respectively. Coincident snow thicknesses ranged between 0.3 to 0.47 m (mean) and 0.1 to 0.5 m (mode). The profile spanned the complete multiyear ice zone in the Lincoln Sea, into the first-year ice zone farther north. Complementary snow thickness measurements near the North Pole showed a mean thickness of 0.31 m. Compared with scarce measurements from other years, multiyear ice was up to 0.75 m thinner than in 2004, but not significantly different from 2011 and 2014. We found excellent agreement with a commonly used snow climatology and with published long-term ice thinning rates. There was reasonable agreement with CryoSat-2 thickness retrievals. [ABSTRACT FROM AUTHOR]

The apportionment process that precedes redistricting is generally a staid American political ritual. Recent debates about who should be included in the apportionment basis, however, have raised new questions about representation in the apportionment process. To estimate the effects of excluding non-citizens and children from apportionment, we describe an algorithm to simulate drawing of state legislative districts, based on a previously published algorithm, Seed-Fill-Shift-Repair (SFSR), designed to draw congressional districts. To account for the larger number of districts to draw we implement an adapted search heuristic that is able to efficiently create contiguous and population-balanced maps for state legislative districts, which we call SFSR-G. We use SFSR-G to simulate 1000 maps of upper and lower legislative chambers in 12 states to demonstrate that a shift from total population to citizen voting age population as the apportionment basis will reduce minority–majority and minority-opportunity districts. The paper presents findings for all 12 states investigated, and discusses the important case of Texas at greater length. [ABSTRACT FROM AUTHOR]

Objective Hyperkalaemia is a common feature in hospitalized patients and often attributed to drugs antagonizing the renin-angiotensin-aldosterone system ( RAAS) and/or acute kidney injury ( AKI), despite significantly preserved glomerular filtration rate ( GFR). The objective of this study was to determine the prevalence and role of renal tubular acidosis type IV ( RTA IV) in the development of significant hyperkalaemia. Design A single-centre retrospective study. Patients Patients admitted to a University Hospital over 12 months. Measurements Patients with a potassium value > 6·0 m m were identified. Clinical and laboratory data were revisited, and patients with a normal anion gap metabolic acidosis were evaluated for the existence of RTA IV. Results A total of 57 patients having significant hyperkalaemia (>6·0 m m) were identified. Twelve patients had end-stage renal disease, while 21 patients had solely AKI or progressive chronic renal failure. RTA IV was present in 24 patients (42%), of whom 71% had pre-existing renal insufficiency because of diabetic nephropathy or tubulointerstitial nephritis. All hyperkalaemic patients with urinary/serum electrolytes suggestive of RTA IV had evidence of AKI, but creatinine levels were significantly lower ( P < 0·05), while the number of drugs antagonizing the RAAS was comparable. Conclusion We demonstrated that RTA IV (i) is very common in patients with hyperkalaemia; (ii) should always be suspected in hyperkalaemic patients with only moderately impaired GFR; and (iii) may result in significant hyperkalaemia in the presence of both AKI and drugs antagonizing the RAAS. [ABSTRACT FROM AUTHOR]

Background. Integrin αvβ3 plays an important role in the regulation of cell proliferation and neoangiogenesis. We found mesangial de novo expression of integrin αvβ3 in mesangioproliferative glomerulonephritis (MesGN). The aim of the study was to clarify if blockade of αvβ3 integrin with the specific αvβ3-blocking cyclic peptide RGDdFV (cRGD) has beneficial effects on the course of this disease. Methods. Habu snake venom (Habu) GN was induced in male C57BL/6 mice 1 week after uninephrectomy (6 mg Habu toxin/kg body weight intravenously). After 24 h, nephritic animals received αvβ3-inhibitory cRGD or cRAD control peptides for 3 or 7 days, respectively. The kidneys were investigated using morphometry, immunohistochemistry and TaqMan polymerase chain reaction. Results. At Day 3, serum creatinine and albuminuria were lower after cRGD compared to cRAD treatment. At Day 3, glomerulosclerosis index, percentage of glomerular injury, mesangial cell (MC) number and volume density of mesangial matrix were significantly lower (P < 0.05) in cRGD-treated mice than in cRAD-treated controls. At Day 7, only a mild effect of cRGD on mesangial matrix expansion and fibronectin messenger RNA was still detectable (P < 0.05). Complementary in vitro studies in MCs revealed that inhibition of αvβ3 by cRGD-blocked adhesion, reduced proliferation and increased apoptosis of MCs. Conclusion. Habu GN inhibition of integrin αvβ3 by cRGD partly ameliorates early injury but has no or only mild effects on late glomerular lesions. [ABSTRACT FROM AUTHOR]

The temporal and spatial variability of sea-ice radar signatures in the Southern Ocean during late winter, spring and early summer from QuikSCAT data is presented. We observe a circumpolar and broad band of sea-ice close to the marginal ice zone that is characterized by very high radar backscatter. This feature is explained through detailed in situ observations of snow and sea-ice properties as well as in relation to meteorological conditions, which were derived from US National Center for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis data. Our results indicate that high backscatter regions are caused by metamorphous snow, which forms through re-freezing after short-term melt events. This process is connected with the episodic passes of low-pressure systems entraining warmer air from the north. South of the Antarctic Circumpolar Trough, sea-ice is not affected by this influence and shows spatially homogenous microwave signatures with low backscatter. [ABSTRACT FROM AUTHOR]

Abstract: In the marginal sea ice zone (MIZ), where relatively small ice floes are dominant, the floe size distribution is an important parameter affecting melt processes given the larger cumulative perimeter of multiple small floes compared with a single ice floe of the same area. Smaller ice floes are therefore subject to increased lateral melt. However, the available data have been very limited so far. Analysis of sea ice in the Sea of Okhotsk revealed that while floe size distribution is basically scale invariant, a regime shift occurs at a size of about 40m. In order to extend this preliminary result to the Antarctic MIZ and further examine the controlling factors, the first concurrent ice floe size and ice thickness measurements were conducted in the northwestern Weddell Sea and off Wilkes Land (around 64°S, 117°E) with a heli-borne digital video camera in the late winter of 2006 and 2007, respectively. The floe sizes ranged from 2 to 100m. Our analysis shows: 1) the scale invariance and regime shift are confirmed in both regions; 2) the floe size at which regime shift occurs slightly increases from 20 to 40m, with ice thickness, consistent with the theory of the flexural failure of sea ice; and 3) the aspect ratio is 1.6-1.9 on average, close to the previous results. Based on these results, the processes affecting the floe size distribution and the subsequent implications on melt processes are discussed. By applying a renormalization group method to interpret the scale invariance in floe size distribution, the fractal dimension is related to the fragility of sea ice. These results indicate the importance of wave-ice interaction in determining the floe size distribution. [Copyright &y& Elsevier]

Abstract: We present the prototype of a simplified photogrammetric system (HELicopter-borne Ice Observation System, HELIOS) and demonstrate how it can be used to document ground-based and airborne sea ice surveys. The aerial unit consists of a nadir-looking digital camera mounted on a gimbal, a GPS receiver and a computer. It is of low-cost and weight and is designed such that it withstands low temperatures, operates autonomously and fits to any standard helicopter skid. The accuracy of the georeferenced photographs is about ±15m for a flight height of 85m, flight speed of 130km/h and a GPS sampling rate of 4Hz. Systematic errors arise from the GPS-based determination of the camera position, the pointing accuracy of the gimbal, and the camera alignment in flight direction. Because most sea ice mapping projects require lesser accuracies than conventional mapping standards (e.g. ≤0.5m for a map scale of 1:600, ASPRS (1994)), HELIOS offers a broad range of applications. This includes the photogrammetric documentation of experimental sites as well as the verification of satellite-, and model-based estimates of sea ice and snow cover properties. Images taken simultaneously with other airborne observations provide a valuable tool to assess the accuracy of those measurements. [Copyright &y& Elsevier]

Abstract: Sea ice is an important climate variable and is also an obstacle for marine operations in polar regions. We have developed a small and lightweight, digitally operated frequency-domain electromagnetic-induction (EM) system, a so-called EM bird, dedicated for measurements of sea ice thickness. It is 3.5 m long and weighs only 105 kg, and can therefore easily be shipped to remote places and operated from icebreakers and small helicopters. Here, we describe the technical design of the bird operating at two frequencies of f1=3.68 kHz and f2=112 kHz, and study its technical performance. On average, noise amounts to ±8.5 ppm and ±17.5 ppm for f1 and f2, respectively. Electrical drift amounts to 200 ppm/h and 2000 ppm/h for f1 and f2, during the first 0.5 h of operation. It is reduced by 75% after 2 h. Calibration of the Inphase and Quadrature ppm signals varies by 2 to 3%. A sensitivity study shows that all these signal variations do affect the accuracy of the ice thickness retrieval, but that it remains better than ±0.1 m over level ice in most cases. This accuracy is also confirmed by means of comparisons of the helicopter EM data with other thickness measurements. The paper also presents the ice thickness retrieval from single-component Inphase data of f1. [Copyright &y& Elsevier]

Abstract: Helicopter-borne and ground-based electromagnetic (EM) ice thickness and ruler-stick snow thickness measurements as well as ice-core analyses of ice temperature, salinity and texture were performed over a 5-week observation period between November 27, 2004, and January 2, 2005, on an ice floe in the western Weddell Sea at approximately 67°S, 55°W. The study was part of the Ice Station Polarstern (ISPOL) expedition of German research icebreaker R.V. Polarstern, investigating changes of physical, biological, and biogeochemical properties during the spring warming as a function of atmospheric and oceanic boundary conditions. The ice floe was composed of fragments of thin and thick first-year ice and thick second-year ice, with modal total thicknesses of 1.2–1.3, 2.1, and 2.4–2.9m, respectively. This included modal snow thicknesses of 0.2–0.5m on first-year ice and 0.75m on second-year ice. During the observation period, snow thickness decreased by less than 0.2m. There was hardly any ice thinning. Warming of snow and ice between 0.1 and 1.9°C resulted in decreased ice salinity and increased brine volume. Direct current (DC) geoelectric and electromagnetic (EM) induction depth sounding were performed to study changes of electrical ice conductivity as a result of the observed ice warming. Bulk ice conductivity increased from to 37 to 97mS/m. Analysis of conductivity anisotropy showed that the horizontal ice conductivity changed from 9 to 70mS/m. These conductivity changes have only negligible effects on the thickness retrieval from EM measurements. [Copyright &y& Elsevier]

Abstract: Aerial band transect censuses were carried out parallel with ice thickness profiling surveys in the pack ice of the western Weddell Sea during the ISPOL (Ice Station POLarstern) expedition of R.V. Polarstern from November 2004 to January 2005. Three regions were surveyed: the deep sea of the Weddell Sea, a western continental shelf/slope region where R.V. Polarstern passively drifted with an ice floe (ISPOL), and a northern region (N). Animal densities were compared among regions and in relation to bathymetry and ice thickness distribution. Crabeater seals Lobodon carcinophaga were the most abundant species in all three regions. Their density was significantly lower in the deep sea (0.50km−2) than in the ISPOL (1.00km−2) and northern regions (1.21km−2). Weddell seals Leptonychotes weddellii were not sighted in the deep-sea region, their density elsewhere ranging from 0.03 (N) to 0.08km−2 (ISPOL). Leopard seals Hydrurga leptonyx were observed in all three areas, but could only be quantified in the deep-sea (0.05km−2) and northern regions (0.06km−2). The abundance of emperor penguins Aptenodytes forsteri was markedly higher in the northern (0.75km−2) than in the ISPOL (0.13km−2) and the deep-sea region (not quantified). Crabeater seal density was significantly related to ocean depth and modal ice thickness. [Copyright &y& Elsevier]

Abstract: In the framework of the R.V. Polarstern expedition “Ice station POLarstern” (ISPOL) spatial and temporal trends in composition, abundance and age structure of sea ice inhabiting copepods were investigated in the western Weddell Sea during the transition from the spring to the summer state. For the spatial scale, sea-ice coring was performed at six locations on a transect from the ice edge to the ice-drift station between 14 and 24 November 2004. The temporal changes were investigated in a time series study on a drifting sea-ice floe from 29 November to 30 December 2004. A relatively large number of copepod species (15) were found in the ice with a higher number at the time station (13) than at the transect (9). Drescheriella spp. was by far the most abundant taxon encountered in the sea ice throughout the present study (72–87%). On the transect, Idomene antarctica ranked second in abundance (7%) followed by Stephos longipes (2%) and Ectinosoma sp. (2%). In contrast, Diarthrode cf. lilacinus, which was not found on the transect, was the second most abundant species (11%) at the time station, followed by I. antarctica (9%), Ectinosoma sp. (6%) and S. longipes (1%). Naupliar stages dominated the populations of Drescheriella spp. and S. longipes both on the transect and during the time series. The Ectinosoma sp. population was dominated by nauplii only at the stations of the transect, while copepodite stages made up the largest fraction during the time series. Copepodids always predominated the I. antarctica populations, and it was the only species in which adults occurred in high densities contributing significantly to the abundance. Only Drescheriella spp. and S. longipes occurred throughout the sea-ice cores, while the occurrence of all other species was restricted to the bottom layer of the ice. The distribution of all species was very patchy and varied greatly between the sampling sites. [Copyright &y& Elsevier]

The article presents a study which aimed to use a gene therapy approach to examine the role of interleukin-13 (IL-13) in angiogenesis in vivo, using a rat adjuvant-induced arthritis model of rheumatoid arthritis (RA). In the study, ankle joints of female rats were injected preventatively with an adenovirus vector containing human IL-13 (AxCAIL-13), a control vector with no insert (AxCANI) or phosphate buffered saline (PBS). Results of the study showed AxCAIL-13-treated joint homogenates had lower hemoglobin levels, suggesting reduced joint vascularity.

The article focuses on a study which investigated the hypothesis that endothelial progenitor cells (EPCs) selectively home to inflamed joint tissue and may perpetuate synovial neovascularization. The neovascularization and EPC accumulation in mouse ankle synovium was measured using a collagen-induced arthritis (CIA) model. It was found that cells bearing EPC markers were significantly increased in peripheral blood and accumulated in inflamed synovial pannus, in mice with CIA.

It is well known that applying vibrations to men influences multiple physiological functions. The authors analysed post effects of whole-body-vibration (WBV) on motor symptoms in Parkinson's disease (PD). Sixty-eight persons with PD were randomly subdivided into one experimental and one control group. Motor symptoms were assessed by the UPDRS (Unified Parkinson's Disease Rating Scale) motor score. A cross-over design was used to control treatment effects. The treatment consisted of 5 series of whole-body-vibration taking 60 seconds each. On average a highly significant (p<0.01) improvement of 16.8% in the UPDRS motor score was found in the treatment group. Only marginal changes (p>0.05) were found in the control group. The cross-over procedure showed comparable treatment effects (14.7% improvement after treatment). With respect to different symptom clusters only small changes were found in limb akinesia and cranial symptoms. By contrast, tremor and rigidity scores were improved by 25% and 24%, respectively. According to the structure of symptom changes it is unlikely that these effects are explainable on peripheral sensory level, exclusively. With respect to the findings of other studies one can speculate about changes in activation of the supplementary motor area and in neurotransmitter functions. [ABSTRACT FROM AUTHOR]

l,25(OH)2D3 has antiproliferative effects and promotes cell differentiation. This consideration has provided the rationale for studies in subtotally nephrectomized rats showing that 1,25(OH)2D3 interferred with glomerulosclerosis. The cellular mechanisms involved have remained obscure, however. It was the purpose of the present study to assess glomerular structure and cellular composition in subtotally nephrectomized (SNX) rats treated with nonpharmacological doses of 1,25(OH)2D3. Male Sprague-Dawley rats were sham operated (sham) or underwent SNX under general anesthesia and received either solvent or 1,25(OH)2D3 (3 ng·100 g body wt-1·day-1 sc). Blood pressure (BP) and albuminuria were measured. After 16 wk, the remnant renal tissue was perfusion fixed and morphometric and stereological measurements were carried out. The expression of proliferating cellular antigen (PCNA), cyclin-dependent kinase inhibitor p27, Wilms tumor gene (WT1), and desmin, a marker of early podocyte damage, was investigated by immunohistology. BP, serum creatinine, and urinary albumin excretion were significantly higher in SNX than in sham rats. Albuminuria was significantly lower in SNX+l,25(OH)2D3 compared with SNX+solvent rats. Mean glomerular tuft volume was significantly higher in SNX+solvent (2.69 ± 0.21 × 106 µm³) than in sham rats (1.44 ± 0.17 and 1.28 ± 0.14 × 106 µm³); it was significantly (P < 0.05) lower in SNX+1,25(OH)2D3 rats (1.81 ± 0.16 × 106 µm³). The main finding was a significantly higher number of podocytes in SNX+l,25(OH)2D3 (88 ± 9) and sham (98 ± 17) compared with SNX+solvent rats (81 ± 8.7). In parallel, the increase in podocyte volume in SNX+ solvent rats was abrogated by treatment with 1,25(OH)2D3, and immunohistochemistry revealed less expression of desmin, PCNA, and p27, suggesting less podocyte injury and activation of the cyclin cascade. This study identifies the podocyte as an important target cell for the renoprotective action of 1,25(OH)2D3. This notion is suggested by less evidence of podocyte injury, decreased podocytes loss, and abrogation of podocyte hypertrophy, findings that may also explain less pronounced albuminuria and glomerulosclerosis. [ABSTRACT FROM AUTHOR]

Matrix metalloproteinases (MMPs) are enzymes with metal ion-dependent activity that degrade extracellular matrix (ECM) glycoproteins. MMPs play a vital role in various biological processes, such as embryogenesis, tissue remodeling, angiogenesis, and wound healing, and in certain disease processes, for example, metastasis of cancer cells. Following their activation, MMPs are believed to modulate both cell-cell and cell-matrix interactions, which in turn regulate cellular differentiation, migration, proliferation, and cell survival. Being involved in pericellular proteolysis, they maintain a gradient of ECM proteins by balancing ECM synthesis and degradation. Such a balance is critical for various mammalian developmental processes during embryonic life and also for the homeostasis of various organs and reparative processes in later life. During the past two decades the role of MMPs in the morphogenesis of various organs, including that of the metanephros, has been investigated extensively. Mammalian nephrogenesis comprises a series of intricate events characterized by a sustained remodeling and turnover of ECM, suggesting a potential role of MMPs in renal development. Conceivably, reciprocal inductive epithelial-mesenchymal interactions that take place at the very commencement of nephrogenesis are modulated by a number of ECM proteins. Their expression, especially at the epithelial-mesenchymal interface, are critical for metanephric development, and such a strategic expression is likely to be modified by a number of different macromolecules that exhibit spatiotemporal and stage-specific expression. Among them the most suitable candidate that could exert such a control would be MMPs. This review addresses the current status of our understanding of the functions and the role of MMPs in renal development. [ABSTRACT FROM AUTHOR]

Measurements of superimposed ice formation and snow properties as a function of the surface energy balance during melt-onset are presented. They were performed on fast ice on Kongsfjorden, Svalbard, between late May and early June 2002. On May 27, rapid snow melt commenced and within 5 days the snow cover initially 0.23 m thick transformed completely into 0.05–0.06 m of superimposed ice. The superimposed ice formed by both percolation of melt water to ice layers and by settling of snow between ice layers. Melt-onset was characterized by rapid changes in the total energy balance, which became positive throughout the whole day after May 27. The increased energy fluxes were mainly caused by higher incoming longwave radiation due to overcast conditions. The observations show that superimposed ice contributes significantly to sea ice mass balance. [Copyright &y& Elsevier]

Aims In contrast to cyclosporin, only limited information exists on the interaction potential between the immunosuppressive agent tacrolimus and HMG-CoA reduc-tase inhibitors, which are metabolized via the cytochrome P450 system. The aim of this study was to investigate the pharmacokinetics, and adverse effects of cerivastatin combined with tacrolimus in renal transplant patients. Methods Ten patients with stable kidney graft functions and LDL-cholesterol serum concentrations >110 mg dl[SUP-1] were included in the study. After an observation period of 3 months, cerivastatin (0.2 mg daily) was administered for an additional 3 months. Tacrolimus steady-state pharmacokinetics and cerivastatin single- and multiple-dose pharmacokinetics were determined. Lipid concentrations, routine laboratory parameters and adverse events were obtained and analysed throughout the study period of 6 months. Results Blood tacrolimus trough concentrations were not affected by cerivastatin (mean± SD 8.6± 2.1 ng ml[SUP-1] before, and 8.7± 2.4 ng ml[SUP-1] at day 90 of cerivastatin dosing, with a 95% confidence interval on the difference = 0.97, 1.08). The mean area under the blood concentration-time curve to 24 h (AUC[SUB(0,24 h])) for cerivastatin was 14.5± 2.53μg l[SUP-1]h[SUP-1] at day 1 after starting treatment and 19.02± 3.55mg l[SUP-1] h[SUP-1] (3 months later), resulting in a 35% higher (AUC[SUP(0,24 h)]) compared with the)first dose. Total cholesterol, LDL-cholesterol and triglyceride concentrations were significantly lowered by cerivastatin whereas no significant effect of cerivastatin on serum creatininkinase concentrations was observed and no adverse effects were documented. Conclusions Tacrolimus increased the AUC[SUB(0, 24 h)] of cerivastatin by a mean of 35% in renal transplant patients. Cerivastatin had no detectable effect on the pharmaco-kinetics of tacrolimus. [ABSTRACT FROM AUTHOR]

Examines molecular evidences for stages of tuberculosis in ancient bone samples in Hungary. Use of osseous tissue specimens; Amplification of the IS6110 sequence; Importance of polymerase chain reaction for recognizing DNA segments of different mycobacterial species; Significance of DNA primers with 65-kDa antigen gene.

The article presents the clinical history, clinical images, and diagnosis of an asymptomatic patient who was previously detected with mediastinal mass. It mentions several physical examination techniques used to determine the diagnosis of the patient which include chest radiograph, X-rays, and computed tomography (CT) scan. It says that the most plausible diagnosis for the patient's case is retrosternal goiter.

A letter to the editor is presented regarding the treatment of patients who suffer from an invasive thymic carcinoma with solid kidney-pancreas transplant by maintaining graft function.

Cryopyrin-associated periodic syndromes (CAPS) are orphan hereditary auto-inflammatory diseases with various phenotypes, including chronic kidney disease (CKD). Current therapies inhibit interleukin-1 (IL-1) to achieve clinical and serological remission; however, the effect on kidney involvement remains unclear. The objective of this study was to investigate the long-term efficacy of anti-IL-1 treatment with special emphasis on renal outcome. We retrospectively analysed clinical, genetic and laboratory data of patients with CAPS under anti-IL-1 therapy from a single-centre university outpatient clinic. Patients with CAPS (n = 28) were followed for a median of 11 (IQR 8.5–13) years. Four patients at various ages (19%), bearing the most common CAPS mutation R260W, had significant CKD at presentation. All affected patients were related; however, other family members with the same genetic variant did not develop CKD. While anti-IL-1 therapy was effective in lowering symptom burden and inflammatory parameters in all CAPS patients, two of the four individuals with significant CKD had persistent proteinuria and worsening kidney function. None of the patients without renal affection at therapy initiation developed relevant CKD in the follow-up period. We showed that in patients with CAPS: (1) CKD is a common complication; (2) renal involvement shows familial predisposition beyond the mutational status and is independent of age; (3) anti-IL-1 therapy results in sustained improvement of inflammatory parameters and symptom load and (4) may prevent development of CAPS-associated CKD but not affect kidney involvement when already present. Overall, early therapy initiation might sufficiently prevent renal disease manifestation and attenuate progression. [ABSTRACT FROM AUTHOR]

Here, we present observations of temporal variability of sub-ice platelet layer over seasonal and diurnal timescales under Ice Shelf Water-influenced fast ice in McMurdo Sound. Electromagnetic induction (EM) sounding time-series measurements of the thicknesses of fast ice and sub-ice platelet layer were made in winter and late spring of 2018. Winter objectives were to measure the seasonal growth of fast ice and sub-ice platelet layer near the McMurdo Ice Shelf in the east, while in late spring we assessed the diurnal variability of sub-ice platelet layer with coincident EM time-series and oceanographic measurements collected in the main outflow path of supercooled Ice Shelf Water in the west. During winter, we observed when the sub-ice platelet layer formed beneath consolidated ice. Episodes of rapid sub-ice platelet layer growth (∼ 0.5–1 m) coincided with strong southerly wind events and polynya activity, suggesting wind-enhanced Ice Shelf Water circulation from the McMurdo–Ross Ice Shelf cavity. In late spring, we investigated how the tides and ocean properties influenced the sub-ice platelet layer. Over a 2-week neap–spring tidal cycle, changes in sub-ice platelet layer thickness were observed to correlate with the tides, increasing more during neap than spring tide cycles, and on diurnal timescales, more on ebb than flood tides. Neap and ebb tides correspond with stronger northward circulation out of the cavity, indicating that sub-ice platelet layer growth was driven by tidally enhanced Ice Shelf Water outflow. The observed variability indicated that wind-driven circulation and the tides influence Ice Shelf Water outflow in McMurdo Sound and, consequently, sub-ice platelet layer evolution over a range of timescales. [ABSTRACT FROM AUTHOR]

Melt ponds are a core component of the summer sea ice system in the Arctic, increasing the uptake of solar energy and impacting the ice-associated ecosystem. They were thus one of the key topics during the 1-year drift campaign Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) in the Transpolar Drift 2019/2020. Pond depth is a dominating factor in describing the surface meltwater volume; it is necessary to estimate budgets and used in model parameterization to simulate pond coverage evolution. However, observational data on pond depth are spatially and temporally strongly limited to a few in situ measurements. Pond bathymetry, which is pond depth spatially fully resolved, remains unexplored. Here, we present a newly developed method to derive pond bathymetry from aerial images. We determine it from a photogrammetric multi-view reconstruction of the summer ice surface topography. Based on images recorded on dedicated grid flights and facilitated assumptions, we were able to obtain pond depth with a mean deviation of 3.5 cm compared to manual in situ observations. The method is independent of pond color and sky conditions, which is an advantage over recently developed radiometric airborne retrieval methods. It can furthermore be implemented in any typical photogrammetry workflow. We present the retrieval algorithm, including requirements for the data recording and survey planning, and a correction method for refraction at the air–pond interface. In addition, we show how the retrieved surface topography model synergizes with the initial image data to retrieve the water level of individual ponds from the visually determined pond margins. We use the method to give a profound overview of the pond coverage on the MOSAiC floe, on which we found unexpected steady pond coverage and volume. We were able to derive individual pond properties of more than 1600 ponds on the floe, including their size, bathymetry, volume, surface elevation above sea level, and temporal evolution. We present a scaling factor for single in situ depth measurements, discuss the representativeness of in situ pond measurements and the importance of such high-resolution data for new satellite retrievals, and show indications for non-rigid pond bottoms. The study points out the great potential to derive geometric properties of the summer sea ice surface emerging from the increasingly available visual image data recorded from uncrewed aerial vehicles (UAVs) or aircraft, allowing for an integrated understanding and improved formulation of the thermodynamic and hydrological pond system in models. [ABSTRACT FROM AUTHOR]

Automated sea ice charting from synthetic aperture radar (SAR) has been researched for more than a decade, and we are still not close to unlocking the full potential of automated solutions in terms of resolution and accuracy. The central complications arise from ground truth data not being readily available in the polar regions. In this paper, we build a data set from 20 near-coincident x-band SAR acquisitions and as many airborne laser scanner (ALS) measurements from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC), between October and May. This data set is then used to assess the accuracy and robustness of five machine-learning-based approaches by deriving classes from the freeboard, surface roughness (standard deviation at 0.5 m correlation length) and reflectance. It is shown that there is only a weak correlation between the radar backscatter and the sea ice topography. Accuracies between 44 % and 66 % and robustness between 71 % and 83 % give a realistic insight into the performance of modern convolutional neural network architectures across a range of ice conditions over 8 months. It also marks the first time algorithms have been trained entirely with labels from coincident measurements, allowing for a probabilistic class retrieval. The results show that segmentation models able to learn from the class distribution perform significantly better than pixel-wise classification approaches by nearly 20 % accuracy on average. [ABSTRACT FROM AUTHOR]

Leads and fractures in sea ice play a crucial role in the heat and gas exchange between the ocean and atmosphere, impacting atmospheric, ecological, and oceanic processes. We estimated lead fractions from high-resolution divergence obtained from satellite synthetic aperture radar (SAR) data and evaluated them against existing lead products. We derived two new lead fraction products from divergence with a spatial resolution of 700 m calculated from daily Sentinel-1 images. For the first lead product, we advected and accumulated the lead fractions of individual time instances. With those accumulated divergence-derived lead fractions, we comprehensively described the presence of up to 10 d old leads and analyzed their deformation history. For the second lead product, we used only divergence pixels that were identified as part of linear kinematic features (LKFs). Both new lead products accurately captured the formation of new leads with widths of up to a few hundred meters. We presented a Lagrangian time series of the divergence-based lead fractions along the drift of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition in the central Arctic Ocean during winter 2019–2020. Lead activity was high in fall and spring, consistent with wind forcing and ice pack consolidation. At larger scales of 50–150 km around the MOSAiC expedition, lead activity on all scales was similar, but differences emerged at smaller scales (10 km). We compared our lead products with six others from satellite and airborne sources, including classified SAR, thermal infrared, microwave radiometer, and altimeter data. We found that the mean lead fractions varied by 1 order of magnitude across different lead products due to different physical lead and sea ice properties observed by the sensors and methodological factors such as spatial resolution. Thus, the choice of lead product should align with the specific application. [ABSTRACT FROM AUTHOR]

To investigate clinical symptoms and genetic variants in patients from the German anti-IL-1 registry for autoinflammatory orphan diseases (GARROD) between 2013 and 2022. Multicentre, retrospective analysis of demographic, clinical and genetic data of patients with autoinflammatory diseases (AID) who received anti-IL-1 targeted therapy. The cohort comprised 152 patients with familial Mediterranean fever (FMF; n = 71), cryopyrin-associated periodic syndromes (CAPS; n = 43), TNF-receptor associated periodic syndrome (TRAPS; n = 19), mevalonate kinase deficiency (MKD; n = 3) and unclassified AID (uAID; n = 16). Inflammatory attacks started in 61.2% of the patients before the age of 18 years. The delay between the first AID attack and anti-IL-1 therapy was 17.8 years. Monogenetic AIDs were diagnosed by clinical symptoms. Genetic analyses confirmed the diagnosis in 87.3% of patients with FMF, 65.2% with CAPS and 94.8% with TRAPS. Among this group, heterozygous MEFV variants and variants of unknown significance (VUS) were detected in 22.5% of patients with FMF, 51.2% with CAPS and 47.4% with TRAPS. Patients with VUS were older at disease onset which is consistent with a milder phenotype. Twenty-four patients had secondary AA amyloidosis (AA) at initiation of anti-IL-1 therapy. The mean age of these patients was 16.4 years at their first attack and 44.9 years at the time of AA diagnosis. Turkish-Armenian ancestry correlated with MEFV variants and higher FMF disease activity compared to German ancestry. Molecular genetic analyses should substantiate the clinical diagnosis of a monogenetic AID. Our data support the concept of variable penetrance of VUS which can be associated with late-onset AID. [ABSTRACT FROM AUTHOR]

Using airborne measurements, we provide a first direct glimpse of the sea ice thickness distribution in the western Ross Sea, Antarctica, where the distinguishing sea ice process is the regular occurrence of the Ross Sea, McMurdo Sound, and Terra Nova Bay polynyas. Two flights in November 2017 over a length of 800 km reveal a heavily deformed ice regime with a mean thickness of 2.0 ± 1.6 m. Supported by satellite image analysis, we identify regional variability in ice thickness based on formation history. Sea ice thickness gradients are highest within 100 and 200 km of the Terra Nova Bay and McMurdo Sound polynyas, respectively, where the mean thickness of the thickest 10% of ice is 7.6 m. Overall, about 80% of the ice is heavily deformed, concentrated in ridges with thicknesses of 3.0–11.8 m. This is evidence that sea ice is much thicker than in the central Ross Sea. Plain Language Summary: Antarctic sea ice is a stabilizing factor for global climate but has an unknown mass trend as thickness is particularly hard to measure. The western Ross Sea is an important region of sea ice formation; here, persistent off‐shore winds form so called coastal polynyas enabling continued freezing by pushing new ice out into the pack ice zone. Using a specialized instrument on a fixed wing aircraft, we measured in this region a mean sea ice thickness of 2 m over a distance of 800 km, which is much thicker than measured in the central Ross Sea. Making use of high‐resolution satellite images and aerial photos, we found that narrow deformational ridges grow up to 16 m in thickness and more rapidly than level ice. Such deformed ice holds up to 80% of the ice mass, which is quite easily overlooked by satellite sensors. Our observations hold a link between wind driven ice dynamics and the ice mass exported from the western Ross Sea, which with this new thickness data could be higher than previously thought. Providing this information, we establish a basis for change detection and the evaluation of computer simulations of Antarctic sea ice in a changing climate. Key Points: Airborne measurements of sea ice thickness in the Western Ross Sea reveal strongly deformed ice with a mean of 2.0 and a maximum of 15.6 mTime series of satellite images show evolution and deformation history of polynya‐derived pack ice along a total survey length of 800 kmSea ice thickness gradients are highest within 100–200 km of polynyas, where the mean thickness of the thickest 10% of ice is 7.6 m [ABSTRACT FROM AUTHOR]

Observations of sea-ice concentration are available from satellites year-round and almost weather-independently using passive microwave radiometers at resolutions down to 5 km. Thermal infrared radiometers provide data with a resolution of 1 km but only under cloud-free conditions. We use the best of the two satellite measurements and merge thermal infrared and passive microwave sea-ice concentrations. This yields a merged sea-ice concentration product combining the gap-free spatial coverage of the passive microwave sea-ice concentration and the 1 km resolution of the thermal infrared sea-ice concentration. The benefit of the merged product is demonstrated by observations of a polynya which opened north of Greenland in February 2018. We find that the merged sea-ice concentration product resolves leads at sea-ice concentrations between 60 % and 90 %. They are not resolved by the coarser passive microwave sea-ice concentration product. The benefit of the merged product is most pronounced during the formation of the polynya. Next, the environmental conditions during the polynya event are analysed. The polynya was caused by unusual southerly winds during which the sea ice drifted northward instead of southward as usual. The daily displacement was 50 % stronger than normal. The polynya was associated with a warm-air intrusion caused by a high-pressure system over the Eurasian Arctic. Surface air temperatures were slightly below 0 ∘ C and thus more than 20 ∘ C higher than normal. Two estimates of thermodynamic sea-ice growth yield sea-ice thicknesses of 60 and 65 cm at the end of March in the area opened by the polynya. This differed from airborne sea-ice thickness measurements, indicating that sea-ice growth processes in the polynya are complicated by rafting and ridging. A sea-ice volume of 33 km3 was produced thermodynamically. [ABSTRACT FROM AUTHOR]

An immediate need for haemodialysis therapy often requires placement of a central vein catheter, which is sometimes complicated by catheter malposition. This report presents the case of a 16-year-old male with end-stage renal disease and a non-functioning central haemodialysis catheter. A chest X-ray identified a very uncommon position of the catheter's tip in a hepatic vein. Management consisted of catheter replacement, resulting in an excellent outcome without sequelae. [ABSTRACT FROM AUTHOR]