Why do avian responses to change in Arctic green-up vary?

Global climate change has altered the timing of seasonal events (i.e., phenology) for a diverse range of biota. Within and among species, however, the degree to which alterations in phenology match climate variability differ substantially. To better understand factors driving these differences, we evaluated variation in timing of nesting of eight Arctic-breeding shorebird species at 18 sites over a 23-year period. We used the Normalized Difference Vegetation Index as a proxy to determine the start of spring (SOS) growing season and quantified relationships between SOS and nest initiation dates as a measure of phenological responsiveness. Among species, we tested four life history traits (migration distance, seasonal timing of breeding, female body mass, expected female reproductive effort) as species-level predictors of responsiveness. For one species (Semipalmated Sandpiper), we also evaluated whether responsiveness varied across sites. Although no species in our study completely tracked annual variation in SOS, phenological responses were strongest for Western Sandpipers, Pectoral Sandpipers, and Red Phalaropes. Migration distance was the strongest additional predictor of responsiveness, with longer-distance migrant species generally tracking variation in SOS more closely than species that migrate shorter distances. Semipalmated Sandpipers are a widely distributed species, but adjustments in timing of nesting relative to variability in SOS did not vary across sites, suggesting that different breeding populations of this species were equally responsive to climate cues despite differing migration strategies. Our results unexpectedly show that long-distance migrants are more sensitive to local environmental conditions, which may help them to adapt to ongoing changes in climate.

Decentralised clinical trials in multiple sclerosis research.

Randomised controlled trials (RCTs) play an important role in multiple sclerosis (MS) research, ensuring that new interventions are safe and efficacious before their introduction into clinical practice. Trials have been evolving to improve the robustness of their designs and the efficiency of their conduct. Advances in digital and mobile technologies in recent years have facilitated this process and the first RCTs with decentralised elements became possible. Decentralised clinical trials (DCTs) are conducted remotely, enabling participation of a more heterogeneous population who can participate in research activities from different locations and at their convenience. DCTs also rely on digital and mobile technologies which allows for more flexible and frequent assessments. While hospitals quickly adapted to e-health and telehealth assessments during the COVID-19 pandemic, the conduct of conventional RCTs was profoundly disrupted. In this paper, we review the existing evidence and gaps in knowledge in the design and conduct of DCTs in MS.

Longitudinal alteration of cortical thickness and volume in high-impact sports.

Collegiate football athletes are subject to repeated head impacts. The purpose of this study was to determine whether this exposure can lead to changes in brain structure. This prospective cohort study was conducted with up to 4 years of follow-up on 63 football (high-impact) and 34 volleyball (control) male collegiate athletes with a total of 315 MRI scans (after exclusions: football n â€‹= â€‹50, volleyball n â€‹= â€‹24, total scans â€‹= â€‹273) using high-resolution structural imaging. Volumetric and cortical thickness estimates were derived using FreeSurfer 5.3's longitudinal pipeline. A linear mixed-effects model assessed the effect of group (football vs. volleyball), time from baseline MRI, and the interaction between group and time. We confirmed an expected developmental decrement in cortical thickness and volume in our cohort (p â€‹< â€‹.001). Superimposed on this, total cortical gray matter volume (p â€‹= â€‹.03) and cortical thickness within the left hemisphere (p â€‹= â€‹.04) showed a group by time interaction, indicating less age-related volume reduction and thinning in football compared to volleyball athletes. At the regional level, sport by time interactions on thickness and volume were identified in the left orbitofrontal (p â€‹= â€‹.001), superior temporal (p â€‹= â€‹.001), and postcentral regions (p â€‹< â€‹.001). Additional cortical thickness interactions were found in the left temporal pole (p â€‹= â€‹.003) and cuneus (p â€‹= â€‹.005). At the regional level, we also found main effects of sport in football athletes characterized by reduced volume in the right hippocampus (p â€‹= â€‹.003), right superior parietal cortical gray (p â€‹< â€‹.001) and white matter (p â€‹< â€‹.001), and increased volume of the left pallidum (p â€‹= â€‹.002). Within football, cortical thickness was higher with greater years of prior play (left hemisphere p â€‹= â€‹.013, right hemisphere p â€‹= â€‹.005), and any history of concussion was associated with less cortical thinning (left hemisphere p â€‹= â€‹.010, right hemisphere p â€‹= â€‹.011). Additionally, both position-associated concussion risk (p â€‹= â€‹.002) and SCAT scores (p â€‹= â€‹.023) were associated with less of the expected volume decrement of deep gray structures. This prospective longitudinal study comparing football and volleyball athletes shows divergent age-related trajectories of cortical thinning, possibly reflecting an impact-related alteration of normal cortical development. This warrants future research into the underlying mechanisms of impacts to the head on cortical maturation.

EANM practice guideline/SNMMI procedure standard for dopaminergic imaging in Parkinsonian syndromes 1.0.

PURPOSE: This joint practice guideline or procedure standard was developed collaboratively by the European Association of Nuclear Medicine (EANM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI). The goal of this guideline is to assist nuclear medicine practitioners in recommending, performing, interpreting, and reporting the results of dopaminergic imaging in parkinsonian syndromes. METHODS: Currently nuclear medicine investigations can assess both presynaptic and postsynaptic function of dopaminergic synapses. To date both EANM and SNMMI have published procedural guidelines for dopamine transporter imaging with single photon emission computed tomography (SPECT) (in 2009 and 2011, respectively). An EANM guideline for D2 SPECT imaging is also available (2009). Since the publication of these previous guidelines, new lines of evidence have been made available on semiquantification, harmonization, comparison with normal datasets, and longitudinal analyses of dopamine transporter imaging with SPECT. Similarly, details on acquisition protocols and simplified quantification methods are now available for dopamine transporter imaging with PET, including recently developed fluorinated tracers. Finally, [18F]fluorodopa PET is now used in some centers for the differential diagnosis of parkinsonism, although procedural guidelines aiming to define standard procedures for [18F]fluorodopa imaging in this setting are still lacking. CONCLUSION: All these emerging issues are addressed in the present procedural guidelines for dopaminergic imaging in parkinsonian syndromes.

A Case of Donor-Transmitted Non-Small Cell Lung Cancer After Liver Transplantation: An Unwelcome Guest.

Cancer transmission with organ donation has been previously reported with a variety of malignancies and organ transplants. The risk of transmission through organ transplantation from donors with a history of previously treated malignancies has been addressed by guidelines from transplant societies. Herein, we report a case of a patient who developed lung cancer confined to the liver after liver transplantation with no known history of malignancy in the donor. The suspicion of donor origin arose after positron emission tomography-computerized tomography scan showed metastatic lung cancer only involving the transplanted liver without a primary focus. Genetic analysis of the malignant cells confirmed donor origin of the cancer.

Meeting the World Health Organization Maternal Antenatal Care Guidelines Is Associated with Improved Early and Middle Childhood Cognition in Ethiopia.

OBJECTIVE: To assess the association between meeting the World Health Organization (WHO) maternal antenatal care attendance guidelines and early and middle childhood cognition among impoverished Ethiopian children. STUDY DESIGN: A total of 1914 impoverished Ethiopian children from the Young Lives longitudinal cohort study were included. Childhood cognition was assessed via the Cognitive Development Assessment (CDA) and Peabody Picture Vocabulary Test (PPVT) at ages 4-5 years; PPVT, Early Grade Reading Assessment (EGRA), and Math Test at ages 7-8 years; and PPVT, Math Test, and Reading Test at ages 11-12 years. Linear regression models were used to examine the association between maternal antenatal care attendance and childhood academic achievement test scores. RESULTS: In the univariable analysis, children of mothers who received the WHO recommended 4+ antenatal care visits or received the WHO recommended first antenatal care visit during the first trimester scored higher on all academic achievement tests. In the multivariable analysis, children of mothers who received 4+ antenatal care visits scored significantly higher on the CDA at ages 4-5 years and Math Test at ages 7-8 years. Children of mothers who received antenatal care in the first trimester scored higher on the CDA at ages 4-5 years and Math Test scores at ages 11-12 years. Children of mothers who received both antenatal care in the first trimester and 4+ antenatal care visits scored significantly higher on the CDA at ages 4-5 years and Math Test at both ages 7-8 and 11-12 years. CONCLUSIONS: Children of mothers who received the WHO recommended number and timing of antenatal care visits had significantly higher academic achievement scores across multiple domains during early and middle childhood. Promotion of antenatal care visit attendance may improve cognition through middle childhood.

Satellite tracking of gulls and genomic characterization of faecal bacteria reveals environmentally mediated acquisition and dispersal of antimicrobial-resistant Escherichia coli on the Kenai Peninsula, Alaska.

Gulls (Larus spp.) have frequently been reported to carry Escherichia coli exhibiting antimicrobial resistance (AMR E. coli); however, the pathways governing the acquisition and dispersal of such bacteria are not well described. We equipped 17 landfill-foraging gulls with satellite transmitters and collected gull faecal samples longitudinally from four locations on the Kenai Peninsula, Alaska to assess: (a) gull attendance and transitions between sites, (b) spatiotemporal prevalence of faecally shed AMR E. coli, and (c) genomic relatedness of AMR E. coli isolates among sites. We also sampled Pacific salmon (Oncorhynchus spp.) harvested as part of personal-use dipnet fisheries at two sites to assess potential contamination with AMR E. coli. Among our study sites, marked gulls most commonly occupied the lower Kenai River (61% of site locations) followed by the Soldotna landfill (11%), lower Kasilof River (5%) and upper Kenai River (<1%). Gulls primarily moved between the Soldotna landfill and the lower Kenai River (94% of transitions among sites), which were also the two locations with the highest prevalence of AMR E. coli. There was relatively high spatial and temporal variability in AMR E. coli prevalence in gull faeces and there was no evidence of contamination on salmon harvested in personal-use fisheries. We identified E. coli sequence types and AMR genes of clinical importance, with some isolates possessing genes associated with resistance to as many as eight antibiotic classes. Our findings suggest that gulls acquire AMR E. coli at habitats with anthropogenic inputs and subsequent movements may represent pathways through which AMR is dispersed.

Neuroimaging of brain trauma.

PURPOSE OF REVIEW: The purpose of this review is to provide an update on advanced neuroimaging techniques in traumatic brain injury (TBI). We will focus this review on recent literature published within the last 18 months and the advanced neuroimaging techniques of perfusion imaging and diffusion tensor imaging (DTI). RECENT FINDINGS: In the setting of a moderate or severe acute closed head injury (Glasgow Coma Scale <13), the most appropriate neuroimaging study is a noncontrast computed tomography (CT) scan. In the setting of mild TBI, the indication for neuroimaging can be determined using the New Orleans Criteria or Canadian CT Head Rules or National Emergency X-Ray Utilization Study-II clinical criteria. Two advanced neuroimaging techniques that are currently being researched in TBI include perfusion imaging and DTI. Perfusion CT has a higher sensitivity for detecting cerebral contusions than noncontrast CT examinations. DTI is a sensitive at detecting TBI at the group level (TBI-group versus control group), but there is insufficient evidence to suggest that DTI plays a clinical role for diagnosing mild TBI at the individual patient level. SUMMARY: Future research in advanced neuroimaging techniques including perfusion imaging and DTI may improve the accuracy of the diagnosis and prognosis as well as improve the management of TBI.

Spring fasting behavior in a marine apex predator provides an index of ecosystem productivity.

The effects of declining Arctic sea ice on local ecosystem productivity are not well understood but have been shown to vary inter-specifically, spatially, and temporally. Because marine mammals occupy upper trophic levels in Arctic food webs, they may be useful indicators for understanding variation in ecosystem productivity. Polar bears (Ursus maritimus) are apex predators that primarily consume benthic and pelagic-feeding ice-associated seals. As such, their productivity integrates sea ice conditions and the ecosystem supporting them. Declining sea ice availability has been linked to negative population effects for polar bears but does not fully explain observed population changes. We examined relationships between spring foraging success of polar bears and sea ice conditions, prey productivity, and general patterns of ecosystem productivity in the Beaufort and Chukchi Seas (CSs). Fasting status (≥7 days) was estimated using serum urea and creatinine levels of 1,448 samples collected from 1,177 adult and subadult bears across three subpopulations. Fasting increased in the Beaufort Sea between 1983-1999 and 2000-2016 and was related to an index of ringed seal body condition. This change was concurrent with declines in body condition of polar bears and observed changes in the diet, condition and/or reproduction of four other vertebrate consumers within the food chain. In contrast, fasting declined in CS polar bears between periods and was less common than in the two Beaufort Sea subpopulations consistent with studies demonstrating higher primary productivity and maintenance or improved body condition in polar bears, ringed seals, and bearded seals despite recent sea ice loss in this region. Consistency between regional and temporal variation in spring polar bear fasting and food web productivity suggests that polar bears may be a useful indicator species. Furthermore, our results suggest that spatial and temporal ecological variation is important in affecting upper trophic-level productivity in these marine ecosystems.

Interference-free determination of sub ng kg-1 levels of long-lived 93Zr in the presence of high concentrations (µg kg-1) of 93Mo and 93Nb using ICP-MS/MS.

Long-lived high abundance radionuclides are of increasing interest with regard to decommissioning of nuclear sites and longer term nuclear waste storage and disposal. In many cases, no routine technique is available for their measurement in nuclear waste and low-level (ng kg-1) environmental samples. Recent advances in ICP-MS technology offer attractive features for the selective and sensitive determination of a wide range of long-lived radionuclides. In this work, inductively coupled plasma-tandem mass spectrometry (ICP-MS/MS)-based methodology, suitable for accurate routine determinations of 93Zr at very low (ng kg-1) levels in the presence of high levels (µg kg-1) of the isobaric interferents 93Nb and 93Mo (often present in nuclear waste samples), is reported for the first time. Additionally, a novel and systematic strategy for method development based on the use of non-radioactive isotopes is proposed. It relies on gas-phase chemical reactions for different molecular ion formation to achieve isobaric interference removal. Using cell gas mixtures of NH3/He/H2 or H2/O2, and suitable mass shifts, the signal from the 93Nb and 93Mo isobaric interferences on 93Zr were suppressed by up to 5 orders of magnitude. The achieved limit of detection for 93Zr was 1.3 × 10-5 Bq g-1 (equivalent to 0.14 ng kg-1). The sample analysis time is 2 min, which represents a significant improvement in terms of sample throughput, compared to liquid scintillation counting methods. The method described here can be used for routine measurements of 93Zr at environmentally relevant levels. It can also be combined with radiometric techniques for use towards the standardisation of 93Zr measurements. Graphical abstract Interference-free determination of 93Zr in the presence of high concentrations of isobaric 93Mo and 93Nb by ICP-MS/MS.

Periodontal condition is associated with disease duration and motoric disabilities in patients with ankylosing spondylitis: results of a cross-sectional study.

OBJECTIVE: Recent literature reveals worse periodontal health condition in ankylosing spondylitis (AS). However, roles of AS-related parameters, periodontal condition, and their association appear unclear. This cross-sectional study aimed at investigating dental and periodontal health as well as potentially periodontal pathogenic bacteria in patients with AS compared to healthy control subjects (HC). METHODS: Dental examination comprised dental findings (DMF-T), periodontal probing depth (PPD), bleeding on probing, clinical attachment loss (CAL), papillary bleeding index, and microbiological analysis based on polymerase chain reaction of selected potentially periodontal pathogenic bacteria. Classification of periodontitis severity was based on PPD and/or CAL and divided into no/mild, moderate, and severe periodontitis. RESULTS: 52 participants with AS and 52 HC were included. 96% of the AS group and 75% of HC had moderate to severe periodontitis (moderate: AS = 26, HC = 34; severe: AS = 23, HC = 5; p < 0.01). Furthermore, a higher number of decayed teeth (D-T) were found in AS compared to HC (p = 0.02). A significant difference between AS und HC was detected for the prevalences of Parvimonas micra (AS = 92%, HC = 71%; p = 0.01), Eubacterium nodatum (AS = 35%, HC = 17%; p = 0.05), and Eikenella corrodens (AS = 96%, HC = 77%; p = 0.01). Bath Ankylosing Spondylitis Metrology Index (BASMI) and disease duration showed significant associations to PPD and CAL (p < 0.01). CONCLUSION: Patients with AS show worse dental and periodontal conditions compared to HC. Thereby, prevalence of bacteria related to insufficient oral hygiene was higher in AS. BASMI and duration of AS affect periodontal burden. Accordingly, particular attention considering dental care and oral hygiene in AS patients seems to be reasonable.

Oral health-related quality of life is associated with disease specific parameters in patients with ankylosing spondylitis.

BACKGROUND: The aim of this cross-sectional study was to investigate oral health-related quality of life (OHRQoL) in patients with ankylosing spondylitis (AS) and its association to oral health as well as AS specific parameters. METHODS: Patients with AS and a healthy control group (HC) were included and examined. The oral examination included decayed-, missing-, and filled-teeth index (DMF-T) as well as assessment of periodontal probing depth and clinical attachment loss to classify patients into healthy/mild, moderate, or severe periodontitis. Furthermore, the German short form of the oral health impact profile (OHIP G14) was used. RESULTS: A total of 50 patients each group (age: AS, 47.18 ± 15.67; HC, 55.82 ± 10.56; p < 0.01, gender male: AS, 52%; HC, 46%; p = 0.69) was included. AS patients showed worse D-T (p < 0.01) and periodontal condition (p = 0.01). The OHIP G14 score was clinically relevant and statistically significant higher in AS compared to HC (AS, 6.2 [2; 0-10.75]; HC, 1.7 [0; 0-2.0]; < 0.01). Only in HC, an association of OHIP G14 to DMF-T (p = 0.01) and M-T (p = 0.01) was found, while the OHIP G14 in AS group was not associated to oral health parameters. Within the AS group, the majority of investigated AS specific parameters were statistically significant and clinically relevant associated to OHIP G14 scores (pi < 0.05). CONCLUSION: Patients with AS show worse OHRQoL compared to HC, irrespective of oral status. The high general disease burden might affect OHRQoL, making an increased attention of these patients in dental care, especially considering psychological aspects, necessary. CLINICAL RELEVANCE: Increased consideration of psychosocial and disease related aspects in dental care of AS patients appear recommendable.

Should Internet Researchers Use Ill-Gotten Information?

This paper describes how the ethical problems raised by scientific data obtained through harmful and immoral conduct (which, following Stan Godlovitch, is called ill-gotten information) may also emerge in cases where data is collected from the Internet. It describes the major arguments for and against using ill-gotten information in research, and shows how they may be applied to research that either collects information about the Internet itself or which uses data from questionable or unknown sources on the Internet. Three examples (the Internet Census 2012, the PharmaLeaks study, and research into keylogger dropzones) demonstrate how researchers address the ethical issues raised by the sources of data that they use and how the existing arguments concerning the use of ill-gotten information apply to Internet research. The problems faced by researchers who collect or use data from the Internet are shown to be the same problems faced by researchers in other fields who may obtain or use ill-gotten information.

Decadal declines in avian herbivore reproduction: density-dependent nutrition and phenological mismatch in the Arctic.

A full understanding of population dynamics depends not only on estimation of mechanistic contributions of recruitment and survival, but also knowledge about the ecological processes that drive each of these vital rates. The process of recruitment in particular may be protracted over several years, and can depend on numerous ecological complexities until sexually mature adulthood is attained. We addressed long-term declines (23 breeding seasons, 1992-2014) in the per capita production of young by both Ross's Geese (Chen rossii) and Lesser Snow Geese (Chen caerulescens caerulescens) nesting at Karrak Lake in Canada's central Arctic. During this period, there was a contemporaneous increase from 0.4 to 1.1 million adults nesting at this colony. We evaluated whether (1) density-dependent nutritional deficiencies of pre-breeding females or (2) phenological mismatch between peak gosling hatch and peak forage quality, inferred from NDVI on the brood-rearing areas, may have been behind decadal declines in the per capita production of goslings. We found that, in years when pre-breeding females arrived to the nesting grounds with diminished nutrient reserves, the proportional composition of young during brood-rearing was reduced for both species. Furthermore, increased mismatch between peak gosling hatch and peak forage quality contributed additively to further declines in gosling production, in addition to declines caused by delayed nesting with associated subsequent negative effects on clutch size and nest success. The degree of mismatch increased over the course of our study because of advanced vegetation phenology without a corresponding advance in Goose nesting phenology. Vegetation phenology was significantly earlier in years with warm surface air temperatures measured in spring (i.e., 25 May-30 June). We suggest that both increased phenological mismatch and reduced nutritional condition of arriving females were behind declines in population-level recruitment, leading to the recent attenuation in population growth of Snow Geese.

Increased Arctic sea ice drift alters adult female polar bear movements and energetics.

Recent reductions in thickness and extent have increased drift rates of Arctic sea ice. Increased ice drift could significantly affect the movements and the energy balance of polar bears (Ursus maritimus) which forage, nearly exclusively, on this substrate. We used radio-tracking and ice drift data to quantify the influence of increased drift on bear movements, and we modeled the consequences for energy demands of adult females in the Beaufort and Chukchi seas during two periods with different sea ice characteristics. Westward and northward drift of the sea ice used by polar bears in both regions increased between 1987-1998 and 1999-2013. To remain within their home ranges, polar bears responded to the higher westward ice drift with greater eastward movements, while their movements north in the spring and south in fall were frequently aided by ice motion. To compensate for more rapid westward ice drift in recent years, polar bears covered greater daily distances either by increasing their time spent active (7.6%-9.6%) or by increasing their travel speed (8.5%-8.9%). This increased their calculated annual energy expenditure by 1.8%-3.6% (depending on region and reproductive status), a cost that could be met by capturing an additional 1-3 seals/year. Polar bears selected similar habitats in both periods, indicating that faster drift did not alter habitat preferences. Compounding reduced foraging opportunities that result from habitat loss; changes in ice drift, and associated activity increases, likely exacerbate the physiological stress experienced by polar bears in a warming Arctic.

Habitat degradation affects the summer activity of polar bears.

Understanding behavioral responses of species to environmental change is critical to forecasting population-level effects. Although climate change is significantly impacting species' distributions, few studies have examined associated changes in behavior. Polar bear (Ursus maritimus) subpopulations have varied in their near-term responses to sea ice decline. We examined behavioral responses of two adjacent subpopulations to changes in habitat availability during the annual sea ice minimum using activity data. Location and activity sensor data collected from 1989 to 2014 for 202 adult female polar bears in the Southern Beaufort Sea (SB) and Chukchi Sea (CS) subpopulations were used to compare activity in three habitat types varying in prey availability: (1) land; (2) ice over shallow, biologically productive waters; and (3) ice over deeper, less productive waters. Bears varied activity across and within habitats with the highest activity at 50-75% sea ice concentration over shallow waters. On land, SB bears exhibited variable but relatively high activity associated with the use of subsistence-harvested bowhead whale carcasses, whereas CS bears exhibited low activity consistent with minimal feeding. Both subpopulations had fewer observations in their preferred shallow-water sea ice habitats in recent years, corresponding with declines in availability of this substrate. The substantially higher use of marginal habitats by SB bears is an additional mechanism potentially explaining why this subpopulation has experienced negative effects of sea ice loss compared to the still-productive CS subpopulation. Variability in activity among, and within, habitats suggests that bears alter their behavior in response to habitat conditions, presumably in an attempt to balance prey availability with energy costs.

Greenhouse gas mitigation can reduce sea-ice loss and increase polar bear persistence.

On the basis of projected losses of their essential sea-ice habitats, a United States Geological Survey research team concluded in 2007 that two-thirds of the world's polar bears (Ursus maritimus) could disappear by mid-century if business-as-usual greenhouse gas emissions continue. That projection, however, did not consider the possible benefits of greenhouse gas mitigation. A key question is whether temperature increases lead to proportional losses of sea-ice habitat, or whether sea-ice cover crosses a tipping point and irreversibly collapses when temperature reaches a critical threshold. Such a tipping point would mean future greenhouse gas mitigation would confer no conservation benefits to polar bears. Here we show, using a general circulation model, that substantially more sea-ice habitat would be retained if greenhouse gas rise is mitigated. We also show, with Bayesian network model outcomes, that increased habitat retention under greenhouse gas mitigation means that polar bears could persist throughout the century in greater numbers and more areas than in the business-as-usual case. Our general circulation model outcomes did not reveal thresholds leading to irreversible loss of ice; instead, a linear relationship between global mean surface air temperature and sea-ice habitat substantiated the hypothesis that sea-ice thermodynamics can overcome albedo feedbacks proposed to cause sea-ice tipping points. Our outcomes indicate that rapid summer ice losses in models and observations represent increased volatility of a thinning sea-ice cover, rather than tipping-point behaviour. Mitigation-driven Bayesian network outcomes show that previously predicted declines in polar bear distribution and numbers are not unavoidable. Because polar bears are sentinels of the Arctic marine ecosystem and trends in their sea-ice habitats foreshadow future global changes, mitigating greenhouse gas emissions to improve polar bear status would have conservation benefits throughout and beyond the Arctic.

Hepatitis E virus serum antibodies and RNA prevalence in patients evaluated for heart and kidney transplantation.

BACKGROUND: Acute hepatitis E virus (HEV) infection in solid organ transplant recipients is rare, but can cause severe hepatic and extrahepatic complications. We sought to identify the pretransplant prevalence of HEV infection in heart and kidney candidates and any associated risk factors for infection. MATERIAL AND METHODS: Stored frozen serum from patients undergoing evaluation for transplant was tested for HEV immunoglobulin G (IgG) antibodies and HEV RNA. All patients were seen at Mayo Clinic Hospital, Phoenix, Arizona, with 333 patients evaluated for heart (n = 132) or kidney (n = 201) transplant. HEV IgG antibodies (anti-HEV IgG) were measured by enzyme-linked immunosorbent assay, and HEV RNA by a noncommercial nucleic acid amplification assay. RESULTS: The prevalence of anti-HEV IgG was 11.4% (15/132) for heart transplant candidates and 8.5% (17/201) for kidney transplant candidates, with an overall seroprevalence of 9.6% (32/333). None of the patients tested positive for HEV RNA in the serum. On multivariable analysis, age older than 60 years was associated with HEV infection (adjusted odds ratio, 3.34; 95% CI, 1.54-7.24; P = 0.002). CONCLUSIONS: We conclude that there was no evidence of acute HEV infection in this pretransplant population and that older age seems to be associated with positive anti-HEV IgG.

Evidence for the exchange of blood parasites between North America and the Neotropics in blue-winged teal (Anas discors).

Blue-winged teal (Anas discors) are abundant, small-bodied dabbling ducks that breed throughout the prairies of the northcentral USA and central Canada and that winter in the southern USA and northern Neotropics. Given the migratory tendencies of this species, it is plausible that blue-winged teal may disperse avian pathogens, such as parasites causing avian malaria, between spatially distant areas. To test the hypothesis that blue-winged teal play a role in the exchange of blood parasites between North America and areas further south, we collected information on migratory tendencies of this species and sampled birds at spatially distant areas during breeding and non-breeding periods to diagnose and genetically characterize parasitic infections. Using a combination of band recovery data, satellite telemetry, molecular diagnostics, and genetic analyses, we found evidence for (1) migratory connectivity of blue-winged teal between our sampling locations in the Canadian prairies and along the US Gulf Coast with areas throughout the northern Neotropics, (2) parasite acquisition at both breeding and non-breeding areas, (3) infection of blue-winged teal sampled in Canada and the USA with Plasmodium parasite lineages associated with the Neotropics, and (4) infection of blue-winged teal with parasites that were genetically related to those previously reported in waterfowl in both North America and South America. Collectively, our results suggest that blue-winged teal likely play a role in the dispersal of blood parasites between the Neotropics and North America, and therefore, the targeting of this species in surveillance programs for the early detection of Neotropical-origin avian pathogens in the USA may be informative.

High-Speed, Integrated Ablation Cell and Dual Concentric Injector Plasma Torch for Laser Ablation-Inductively Coupled Plasma Mass Spectrometry.

In recent years, laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) has gained increasing importance for biological analysis, where ultratrace imaging at micrometer resolution is required. However, while undoubtedly a valuable research tool, the washout times and sensitivity of current technology have restricted its routine and clinical application. Long periods between sampling points are required to maintain adequate spatial resolution. Additionally, temporal signal dispersion reduces the signal-to-noise ratio, which is a particular concern when analyzing discrete samples, such as individual particles or cells. This paper describes a novel, two-volume laser ablation cell and integrated ICP torch designed to minimize aerosol dispersion for fast, efficient sample transport. The holistic design utilizes a short, continuous diameter fused silica conduit, which extends from the point of ablation, through the ICP torch, and into the base of the plasma. This arrangement removes the requirement for a dispersive component for argon addition, and helps to keep the sample on axis with the ICP cone orifice. Hence, deposition of sample on the cones is theoretically reduced with a resulting improvement in the absolute sensitivity (counts per unit mole). The system described here achieved washouts of 1.5, 3.2, and 4.9 ms for NIST 612 glass, at full width half, 10%, and 1% maximum, respectively, with an 8-14-fold improvement in absolute sensitivity, compared to a single volume ablation cell. To illustrate the benefits of this performance, the system was applied to a contemporary bioanalytical challenge, specifically the analysis of individual biological cells, demonstrating similar improvements in performance.