429 research outputs found
Dive Behavior of Eastern Chukchi Beluga Whales (Delphinapterus leucas), 1998â2008
We provide an exploratory description of the dive behavior of 23 beluga whales of the eastern Chukchi Sea stock, tagged with satellite-linked time and depth recorders at Point Lay, Alaska, between 1998 and 2007. Because of differences in how transmitters were parameterized, we analyzed data from tags deployed from 1998 to 2002 (n = 20 tags) and data from tags deployed in 2007 (n = 3 tags) separately. Using cluster analysis, we found three basic dive types in the 1998â2002 dataset. âShallowâ diving behavior was characterized by dives mostly 50 m in depth. âIntermediateâ diving behavior was characterized by having one mode near the surface and a second mode near 250 m. âDeepâ diving behavior was characterized by having one mode near the surface and a second mode more than 400 m from the surface. The average number of dives per hour ranged from 5.1 (SD = 2.1) to 9.8 (SD = 2.9) across dive types, with the fewest dives per hour in the deep diving category. In general, duration of dives ranged from 1 to 18 minutes; however, dives up to 21 minutes occurred in the deepest diving category. We found little evidence that dive behavior of the belugas in our sample varied by sex or age. In general, belugas dove more deeply in the eastern Beaufort Sea than in the western Beaufort or Chukchi Seas. The depths to which belugas most commonly dive in Barrow Canyon and along the Beaufort shelf break (200â300 m) correspond to the boundary where colder Pacific water overlies warmer Atlantic water, which is probably where Arctic cod (Boreogadus saida) are most dense. Diving depths within the Arctic Basin suggest that belugas are foraging mostly within the warm layer of Atlantic Water (~200â1000 m).Nous dressons une description exploratoire du comportement de plongĂ©e de 23 bĂ©lugas du cheptel de lâest de la mer des Tchouktches dotĂ©s de marqueurs dâenregistreurs satellitaires de profondeur temporelle Ă Point Lay, en Alaska, entre 1998 et 2007. En raison des diffĂ©rences de paramĂ©trage des transmetteurs, nous avons analysĂ© sĂ©parĂ©ment les donnĂ©es de marqueurs dĂ©ployĂ©s de 1998 Ă 2002 (n = 20 marqueurs) et les donnĂ©es de marqueurs dĂ©ployĂ©s en 2007 (n = 3 marqueurs). GrĂące Ă une analyse par grappes, nous avons trouvĂ© trois types de plongĂ©e fondamentaux dans lâensemble des donnĂ©es de 1998 Ă 2002. Le comportement de plongĂ©e « en eau peu profonde » Ă©tait principalement caractĂ©risĂ© par des plongĂ©es de 50 m de profondeur. Le comportement de plongĂ©e « intermĂ©diaire » Ă©tait caractĂ©risĂ© par un mode de plongĂ©e prĂšs de la surface et un autre mode Ă prĂšs de 250 m. Le comportement de plongĂ©e « en profondeur » Ă©tait caractĂ©risĂ© par un mode de plongĂ©e prĂšs de la surface et un deuxiĂšme mode Ă plus de 400 m de la surface. Le nombre moyen de plongĂ©es Ă lâheure variait de 5,1 (Ă©cart-type = 2,1) Ă 9,8 (Ă©cart-type = 2,9) pour ce qui est de tous les types de plongĂ©e, la catĂ©gorie des plongĂ©es en profondeur ayant enregistrĂ© le moins grand nombre de plongĂ©es. En gĂ©nĂ©ral, la durĂ©e des plongĂ©es durait de 1 Ă 18 minutes, mais cela dit, certaines des plongĂ©es en profondeur ont durĂ© jusquâĂ 21 minutes. Nous avons trouvĂ© peu dâindices portant Ă croire que le comportement de plongĂ©e des bĂ©lugas de notre Ă©chantillon variait en fonction du sexe ou de lâĂąge. De maniĂšre gĂ©nĂ©rale, les bĂ©lugas plongeaient plus en profondeur dans lâest de la mer de Beaufort que dans lâouest de la mer de Beaufort ou dans la mer des Tchouktches. Les profondeurs auxquelles les bĂ©lugas plongent le plus souvent dans le canyon Barrow et le long du rebord continental de Beaufort (de 200 Ă 300 m) correspondent Ă la limite oĂč lâeau plus froide du Pacifique se superpose Ă lâeau plus chaude de lâAtlantique, lĂ oĂč la morue polaire (Boreogadus saida) est plus dense. Dans le bassin arctique, la profondeur des plongĂ©es suggĂšre que les bĂ©lugas sâalimentent surtout dans la couche tempĂ©rĂ©e dâeau de lâAtlantique (~200 Ă 1 000 m)
Newly diagnosed atrial fibrillation and hospital utilization in heart failure:a nationwide cohort study
AIMS: Atrial fibrillation (AF) constitutes a major burden to health services, but the importance of incident AF in patients with heart failure (HF) is unclear. We examined the associations between incident AF and hospital utilization in patients with HF. METHODS AND RESULTS: In a nationwide matchedâcohort study of HF patients, we identified patients diagnosed with incident AF between 2008 and 2018 in the Danish Heart Failure Registry (NÂ =Â 4463), and we compared them to matched referents without AF (NÂ =Â 17Â 802). Incident AF was associated with a multivariableâadjusted 4.8âfold increase (95% CI 4.1â5.6) and 4.3âfold increase (95% CI 3.9â4.8) in the cumulative incidence of inpatient and outpatient contacts within 30Â days, respectively. At 1Â year, the cumulative incidence ratios were 1.8 (95% CI 1.7â1.9) and 1.4 (95% CI 1.4â1.5). Incident AF was also associated with increases in the total numbers of inpatient and outpatient hospital contacts within 30Â days (multivariableâadjusted rate ratio 1.4, 95% CI 1.4â1.5, and 1.6, 95% CI 1.6â1.7, respectively). At 1Â year, the ratios were 2.2 (95% CI 2.1â2.3) and 2.0 (95% CI 1.9â2.1). The multivariableâadjusted proportion of bedâday use among HF patients with incident AF was 10.9âfold (95% CI 9.3â12.9) higher at 30Â days and 5.3âfold (95% CI 4.3â6.4) higher at 1Â year compared with AFâfree referents. CONCLUSIONS: Incident AF in HF is associated with earlier hospital contact, more hospital contacts, and more hospital bedâdays. More evidence on interventions that may prevent the risk and subsequent burden of AF in HF is urgently needed
Improving regional ozone modeling through systematic evaluation of errors using the aircraft observations during the International Consortium for Atmospheric Research on Transport and Transformation
During the operational phase of the ICARTT field experiment in 2004, the regional air quality model STEM showed a strong positive surface bias and a negative upper troposphere bias (compared to observed DC-8 and WP-3 observations) with respect to ozone. After updating emissions from NEI 1999 to NEI 2001 (with a 2004 large point sources inventory update), and modifying boundary conditions, low-level model bias decreases from 11.21 to 1.45 ppbv for the NASA DC-8 observations and from 8.26 to â0.34 for the NOAA WP-3. Improvements in boundary conditions provided by global models decrease the upper troposphere negative ozone bias, while accounting for biomass burning emissions improved model performance for CO. The covariances of ozone bias were highly correlated to NOz, NOy, and HNO3 biases. Interpolation of bias information through kriging showed that decreasing emissions in SE United States would reduce regional ozone model bias and improve model correlation coefficients. The spatial distribution of forecast errors was analyzed using kriging, which identified distinct features, which when compared to errors in postanalysis simulations, helped document improvements. Changes in dry deposition to crops were shown to reduce substantially high bias in the forecasts in the Midwest, while updated emissions were shown to account for decreases in bias in the eastern United States. Observed and modeled ozone production efficiencies for the DC-8 were calculated and shown to be very similar (7.8) suggesting that recurring ozone bias is due to overestimation of NOx emissions. Sensitivity studies showed that ozone formation in the United States is most sensitive to NOx emissions, followed by VOCs and CO. PAN as a reservoir of NOx can contribute to a significant amount of surface ozone through thermal decomposition
Probabilistic movement model with emigration simulates movements of deer in Nebraska, 1990â2006
Movements of deer can affect population dynamics, spatial redistribution, and transmission and spread of diseases. Our goal was to model the movement of deer in Nebraska in an attempt to predict the potential for spread of chronic wasting disease (CWD) into eastern Nebraska. We collared and radio-tracked \u3e600 white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) in Nebraska during 1990â2006.We observed large displacements (\u3e10 km) for both species and sexes of deer, including migrations up to 100 km and dispersals up to 50 km. Average distance traveled between successive daily locations was 166m for male and 173 for female deer in eastern Nebraska, and 427m for male and 459 for female deer in western Nebraska. Average daily displacement from initial capture point was 10m for male and 14m for female deer in eastern Nebraska, and 27m for male and 28m for female deer in western Nebraska.We used these data on naturally occurring movements to create and test 6 individual-based models of movement for white-tailed deer and mule deer in Nebraska, including models that incorporated sampling from empirical distributions of movement lengths and turn angles (DIST), correlated random walks (CRW), home point fidelity (FOCUS), shifting home point (SHIFT), probabilistic movement acceptance (MOVE), and probabilistic movement with emigration (MOVEwEMI). We created models in sequence in an attempt to account for the shortcomings of the previous model(s). We used the KolmogrovâSmirnov goodness-of-fit test to verify improvement of simulated annual displacement distributions to empirical displacement distributions. The best-fit model (D = 0.07 and 0.08 for eastern and western Nebraska, respectively) included a probabilistic-movement chance with emigration (MOVEwEMI) and resulted in an optimal daily movement length of 350m (maximum daily movement length of 2800m for emigrators) for eastern Nebraska and 370m (maximum of 2960m) for western Nebraska. The proportion of deer that moved as emigrators was 0.10 and 0.13 for eastern and western Nebraska, respectively. We propose that the observed spread of CWD may be driven by large movements of a small proportion of deer that help to establish a low prevalence of the disease in areas east of the current endemic area. Our movement models will be used in a larger individual-based simulation of movement, survival, and transmission of CWD to help determine future surveillance and management actions
A Standardized Strategy for Simultaneous Quantification of Urine Metabolites to Validate Development of a Biomarker Panel Allowing Comprehensive Assessment of Dietary Exposure
SCOPE: Metabolites derived from individual foods found in human biofluids after consumption could provide objective measures of dietary intake. For comprehensive dietary assessment, quantification methods would need to manage the structurally diverse mixture of target metabolites present at a wide concentration range. METHODS & RESULTS: We developed a strategy for selection of candidate dietary exposure biomarkers, providing comprehensive coverage. An analytical method for 62 food biomarkers was validated by extensive analysis of chromatographic and ionization behaviour characteristics using triple quadrupole mass spectrometry. We used urine samples from two food intervention studies: one controlled, inpatient study (n = 19) and the other a free-living study where individuals (n = 15) were provided with food as a series of menu plans. As proof-of-principle, we demonstrated that the biomarker panel could discriminate between menu plans by detecting distinctive changes in the concentration in urine of targeted metabolites. We showed quantitative relationships between four biomarker concentrations in urine and dietary intake. CONCLUSIONS: We have demonstrated design concepts for an analytical strategy allowing simultaneous quantification of a comprehensive panel of chemically-diverse biomarkers of a wide range of commonly-consumed foods. We propose that integration of self-reported dietary recording tools with biomarker approaches will provide more robust assessment of dietary exposure. This article is protected by copyright. All rights reserved
BiblioBouts: A Scalable Online Social Game for the Development of Academic Research Skills
Researchers at the School of Information of the University of Michigan are designing, developing, and evaluating BiblioBouts, an online game that helps students learn academic research skills. Players practice using online library research tools while they work on an in-class assignment and produce a high-quality bibliography, at the same time as they are competing against each other to win the game!
While librarians are experts at helping students who want to learn about academic research, most students are reluctant participants because they want just-in-time personal assistance that is tailored to their unique information needs, and faculty are reluctant to cede class time. The BiblioBouts project enlists games to teach undergraduate students information literacy skills and concepts in the classroom.
Social gaming reinforces principles of good learning, including getting results by trial and error, self-discovery, following hunches and reinforcement through repetition. BiblioBouts also incorporates collaborative problem solving and participation in a community of learning. The project aims to explore how games can be utilized to achieve information literacy goals and to yield open-source game software that libraries could use immediately to enhance their information literacy programs.
The LOEX presentation will incorporate a live interactive demo of the game, as well as videos demonstrating gameplay. We will discuss challenges in situating the game into the classroom and integrating it into existing course syllabi. The presentation will describe how we have adapted the game in response to feedback from students and instructors during the pilot process
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Particle growth in urban and industrial plumes in Texas
Particle size distributions and gas-phase particle precursors and tracer species were measured aboard an aircraft in the plumes downwind from industrial and urban sources in the vicinity of Houston, TX during the daytime in late August and early September 2000. Plumes originating from the Parish gas-fired and coal-fired power plant, petrochemical industries along the Houston ship channel, the petrochemical facilities near the Gulf coast, and the urban center of Houston were studied. Most of the particle mass flux advected downwind of Houston came from the industries and electrical utilities at the periphery of the city rather than from sources in the urban core. In SO2-rich plumes that did not contain elevated concentrations of volatile organic compounds (VOCs), particle volume increased with increasing plume oxidation (age) at a rate consistent with condensation and neutralization of the gas-phase oxidation products Of SO2. In plumes that were rich in both SO2 and VOCs, observed particle growth greatly exceeded that expected from SO2 oxidation, indicating the formation of organic particulate mass. In plumes that were enhanced in VOCs but not in SO2, and in the plume of the Houston urban center, no particle volume growth with increasing plume oxidation was detected. Since substantial particle volume growth was associated only with SO2-rich plumes, these results suggest that photochemical oxidation of SO2 is the key process regulating particle mass growth in all the studied plumes in this region. However, uptake of organic matter probably contributes substantially to particle mass in petrochemical plumes rich in both SO2 and VOCs. Quantitative studies of particle formation and growth in photochemical systems containing nitrogen oxides (NOx = NO + NO2 ), VOCs, and SO2 are recommended to extend those previously made in NOx-VOC systems
The clinical and microbiological utility of inhaled aztreonam lysine for the treatment of acute pulmonary exacerbations of cystic fibrosis: An open-label randomised crossover study (AZTEC-CF)
BACKGROUND: The objective of this study was to explore the clinical and microbiological outcomes associated with substituting inhaled aztreonam lysine for an intravenous antibiotic in the treatment of acute pulmonary exacerbations of CF.
METHODS: An open-label randomised crossover pilot trial was conducted at a UK CF centre among 16 adults with CF and P. aeruginosa infection. Median [IQR] age was 29.5 [24.5-32.5], mean ± SD forced expiratory volume in 1 second (FEV1) was 52.4 ± 14.7 % predicted. Over the course of two exacerbations, participants were randomised to sequentially receive 14 days of inhaled aztreonam lysine plus IV colistimethate (AZLI+IV), or dual IV antibiotics (IV+IV). Primary outcome was absolute change in % predicted FEV1. Other outcomes evaluated changes in quality of life, bacterial load and the lung microbiota.
RESULTS: The difference between mean change in lung function at day 14 between AZLI+IV and IV+IV was +4.6% (95% CI 2.1-7.2, p=0.002). The minimum clinically important difference of the Cystic Fibrosis Revised Questionnaire (CFQ-R) was achieved more frequently with AZLI+IV (10/12, 83.3%) than IV+IV (7/16, 43.8%), p=0.05. No differences were observed for modulation of serum white cell count, C-reactive protein or sputum bacterial load. Microbiome compositional changes were observed with IV+IV (Bray-Curtis r2=0.14, p=0.02), but not AZLI+IV (r2=0.03, p=0.64).
CONCLUSION: In adults with CF and P. aeruginosa infection experiencing an acute pulmonary exacerbation, AZLI+IV improved lung function and quality of life compared to the current standard treatment. These findings support the need for larger definitive trials of inhaled antibiotics in the acute setting.
CLINICAL TRIAL REGISTRATION: EudraCT 2016-002832-34 ClinicalTrials.org NCT02894684
Prostate Cancer Risk by BRCA2 Genomic Regions.
A BRCA2 prostate cancer cluster region (PCCR) was recently proposed (c.7914 to 3') wherein pathogenic variants (PVs) are associated with higher prostate cancer (PCa) risk than PVs elsewhere in the BRCA2 gene. Using a prospective cohort study of 447 male BRCA2 PV carriers recruited in the UK and Ireland from 1998 to 2016, we estimated standardised incidence ratios (SIRs) compared with population incidences and assessed variation in risk by PV location. Carriers of PVs in the PCCR had a PCa SIR of 8.33 (95% confidence interval [CI] 4.46-15.6) and were at a higher risk of PCa than carriers of other BRCA2 PVs (SIRâ=â3.31, 95% CI 1.97-5.57; hazard ratioâ=â2.34, 95% CI 1.09-5.03). PCCR PV carriers had an estimated cumulative PCa risk of 44% (95% CI 23-72%) by the age of 75âyr and 78% (95% CI 54-94%) by the age of 85âyr. Our results corroborate the existence of a PCCR in BRCA2 in a prospective cohort. PATIENT SUMMARY: In this report, we investigated whether the risk of prostate cancer for men with a harmful mutation in the BRCA2 gene differs based on where in the gene the mutation is located. We found that men with mutations in one region of BRCA2 had a higher risk of prostate cancer than men with mutations elsewhere in the gene
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