We examined the number of tropical cyclones and cyclone days as well as tropical cyclone intensity over the past 35 years, in an environment of increasing sea surface temperature. A large increase ...was seen in the number and proportion of hurricanes reaching categories 4 and 5. The largest increase occurred in the North Pacific, Indian, and Southwest Pacific Oceans, and the smallest percentage increase occurred in the North Atlantic Ocean. These increases have taken place while the number of cyclones and cyclone days has decreased in all basins except the North Atlantic during the past decade.
AbstractThe rapid increase in "big data" during the postgenomic era makes it crucial to appropriately measure the level of social complexity in comparative studies. We argue that commonly used ...qualitative classifications lump together species showing a broad range of social complexity and falsely imply that social evolution always progresses along a single linear stepwise trajectory that can be deduced from comparing extant species. To illustrate this point, we compared widely used social complexity measures in "primitively eusocial" bumble bees with "advanced eusocial" stingless bees, honey bees, and attine ants. We find that a single species can have both higher and lower levels of complexity compared with other taxa, depending on the social trait measured. We propose that measuring the complexity of individual social traits switches focus from semantic discussions and offers several directions for progress. First, quantitative social traits can be correlated with molecular, developmental, and physiological processes within and across lineages of social animals. This approach is particularly promising for identifying processes that influence or have been affected by social evolution. Second, key social complexity traits can be combined into multidimensional lineage-specific quantitative indices, enabling fine-scale comparison across species that are currently bundled within the same level of social complexity.
Objective/Research Question: This research explores how community college students, who are underrepresented in science, technology, engineering, and mathematics (STEM) fields and aspire to vertical ...transfer in STEM make choices about majors and transfer destinations. The question is important to advancing equity in STEM, which continues to perpetuate disparities in attainment for minoritized, first-generation, and financially disadvantaged students, who disproportionately enter higher education in community colleges. Methods: Using a longitudinal, qualitative research design, the study relied on semi-structured interviewing to generate in-depth evidence about student experiences. Results: Findings showed that career goals were uniformly influential to students, yet career information was unevenly available or comprehensible during community college. Students’ choices about what to major in and where to transfer were iterative and intertwined, with these choices deeply connected to students’ families and lifetime priorities. Delays in student decision-making tended to have less to do with uncertain individual preferences than to lack of information about a specific STEM major and its alignment with possible future degrees, transfer destinations, and career pathways, as well as contingencies associated with the transfer admission process. Conclusions/Contributions: This research demonstrated STEM-specific nuance in how underrepresented community college students navigate major, career, and transfer destination decision-making as well as the influence of family and location-based priorities in student choices. Future research should investigate how to best provide directional support for students’ major and transfer destination decisions, including major-to-career awareness and the academic and personal dimensions of transfer.
Fluids trapped as inclusions within minerals can be billions of years old and preserve a record of the fluid chemistry and environment at the time of mineralization. Aqueous fluids that have had a ...similar residence time at mineral interfaces and in fractures (fracture fluids) have not been previously identified. Expulsion of fracture fluids from basement systems with low connectivity occurs through deformation and fracturing of the brittle crust. The fractal nature of this process must, at some scale, preserve pockets of interconnected fluid from the earliest crustal history. In one such system, 2.8 kilometres below the surface in a South African gold mine, extant chemoautotrophic microbes have been identified in fluids isolated from the photosphere on timescales of tens of millions of years. Deep fracture fluids with similar chemistry have been found in a mine in the Timmins, Ontario, area of the Canadian Precambrian Shield. Here we show that excesses of (124)Xe, (126)Xe and (128)Xe in the Timmins mine fluids can be linked to xenon isotope changes in the ancient atmosphere and used to calculate a minimum mean residence time for this fluid of about 1.5 billion years. Further evidence of an ancient fluid system is found in (129)Xe excesses that, owing to the absence of any identifiable mantle input, are probably sourced in sediments and extracted by fluid migration processes operating during or shortly after mineralization at around 2.64 billion years ago. We also provide closed-system radiogenic noble-gas ((4)He, (21)Ne, (40)Ar, (136)Xe) residence times. Together, the different noble gases show that ancient pockets of water can survive the crustal fracturing process and remain in the crust for billions of years.
Better understanding of how students achieve vertical transfer is vital for advancing equity in science, technology, engineering and mathematics (STEM) majors. Among the many sources of barriers, ...delays, and complexities demonstrated in previous research as influencing vertical transfer outcomes, the transfer admission process has been generally neglected. Using a longitudinal, qualitative design, and drawing on transfer capital and field theories, this study investigated how community college students who are underrepresented in STEM fields successfully navigated admission to a four-year institution in a STEM major. Results indicated that students experienced transfer admission as risky and uncertain. They accrued transfer capital over time, in the form of knowledge about transfer admission and strategies to bolster their competitiveness, including regulating their coursework intensity and actively managing their GPAs. Although these forms of transfer capital helped students succeed in transferring, some strategies could backfire, causing unintended negative consequences, such as time-to-completion delays, excess credit accumulation, or disadvantages in securing admission. Results supported the contention that the transfer admission process is a pivotal, yet largely neglected aspect of student experience in STEM vertical pathways. Conclusions provide suggestions for further research and implications for institutional practice.
Gaia Data Release 1 Carrasco, J M; Evans, D W; Montegriffo, P ...
Astronomy and astrophysics (Berlin),
11/2016, Letnik:
595
Journal Article
Recenzirano
Odprti dostop
Context. Gaia is an ESA cornerstone mission launched on 19 December 2013 aiming to obtain the most complete and precise 3D map of our Galaxy by observing more than one billion sources. This paper is ...part of a series of documents explaining the data processing and its results for Gaia Data Release 1, focussing on the G band photometry. Aims. This paper describes the calibration model of the Gaia photometric passband for Gaia Data Release 1. Methods. The overall principle of splitting the process into internal and external calibrations is outlined. In the internal calibration, a self-consistent photometric system is generated. Then, the external calibration provides the link to the absolute photometric flux scales. Results. The Gaia photometric calibration pipeline explained here was applied to the first data release with good results. Details are given of the various calibration elements including the mathematical formulation of the models used and of the extraction and preparation of the required input parameters (e.g. colour terms). The external calibration in this first release provides the absolute zero point and photometric transformations from the GaiaG passband to other common photometric systems. Conclusions. This paper describes the photometric calibration implemented for the first Gaia data release and the instrumental effects taken into account. For this first release no aperture losses, radiation damage, and other second-order effects have not yet been implemented in the calibration.
SUMMARY
Symptomatic dysphagia is believed to be more common in the older population; however, the factors that predict age‐related dysphagia are less well‐understood. Here, we describe a ...questionnaire‐based survey of swallowing dysfunction in a large, otherwise ‘healthy’ community dwelling older population in the UK in whom additional cognitive and depression related scores were evaluated. A postal survey using Sydney oropharyngeal dysphagia questionnaire was sent to 800 residences in the North of England that formed part of the University of Manchester Age and Cognitive Performance Longitudinal Study. This cohort was composed of older individuals (mean age 81 range 69–98 years) who are otherwise healthy with no history of previous neurological disease. The postal questionnaire is a validated self‐report inventory measuring symptoms of oropharyngeal dysphagia covering a total of 17 domains of swallowing function. The maximal score obtainable is 1700, with a score of ≥200 arbitrarily considered to indicate swallowing difficulty. Cognitive performance and depression scores utilized the telephone interview cognitive screen and the Geriatric Depression Scale. All data were analyzed in SPSS. Of the 800 questionnaires sent out, 637 where returned. Three were later discarded as unusable after follow‐up telephone interviews of incomplete forms, giving a completed response rate of 79%. Females made up 77% of the total respondents. Of the population, 11.4% reported symptoms indicative of significant dysphagia. Unsurprisingly, dysphagia severity was directly correlated with subject age (r= 0.11, P= 0.007). When cognitive factors were taken into account, there was no correlation between memory, recall, and mental performance and dysphagia; however, depression was strongly and independently associated (P= 0.002) with dysphagia symptoms. Dysphagia symptoms are prevalent in older people, affecting nearly one in nine people who are otherwise living independently in the community. While cognitive factors such as memory recall do not seem to influence dysphagia symptoms, depression is associated with dysphagia, suggesting a potential interaction. This could relate to associations with quality of life or psychological factors.
Abstract Introduction Regenerative endodontic protocols recommend white mineral trioxide aggregate (WMTA) as a capping material because of its osteoinductive properties. Stem cells from the apical ...papilla (SCAP) are presumed to be involved in this regenerative process, but the effects of WMTA on SCAP are largely unknown. Our hypothesis was that WMTA induces proliferation and migration of SCAP. Methods Here we used an unsorted population of SCAP (passages 3–5) characterized by high CD24, CD146, and Stro-1 expression. The effect of WMTA on SCAP migration was assessed by using transwells, and its effect on proliferation was determined by the WST-1 assay. Fetal bovine serum (FBS) and calcium chloride–enriched medium were used as positive controls. Results The SCAP analyzed here showed a low percentage of STRO-1+ and CD24+ cells. Both set and unset WMTA significantly increased the short-term migration of SCAP after 6 hours ( P < .05), whereas calcium chloride–enriched medium did after 24 hours of exposure. Set WMTA significantly increased proliferation on days 1–5, whereas calcium-enriched medium showed a significant increase on day 7, with a significant reduction on proliferation afterwards. SCAP migration and proliferation were significantly and steadily induced by the presence of 2% and 10% FBS. Conclusions Collectively, these data demonstrate that WMTA induced an early short-term migration and proliferation of a mixed population of stem cells from apical papilla as compared with a later and longer-term induction by calcium chloride or FBS.
BioJava is a mature open-source project that provides a framework for processing of biological data. BioJava contains powerful analysis and statistical routines, tools for parsing common file formats ...and packages for manipulating sequences and 3D structures. It enables rapid bioinformatics application development in the Java programming language. Availability: BioJava is an open-source project distributed under the Lesser GPL (LGPL). BioJava can be downloaded from the BioJava website (http://www.biojava.org). BioJava requires Java 1.5 or higher. Contact: andreas.prlic@gmail.com. All queries should be directed to the BioJava mailing lists. Details are available at http://biojava.org/wiki/BioJava:MailingLists.
Across the United States, wildfire severity and frequency are increasing, placing many properties at risk of harm or destruction. We quantify and compare how different forest management strategies ...designed to increase forest resilience and health reduce the number of properties at risk from wildfire, focusing on the Lake Tahoe Basin of California and Nevada. We combine landscape change simulations (including climate change, wildfire, and management effects) with scenarios of current and plausible fuel treatment activities and parcel-scale fire risk analysis. Results suggest that more aggressive fuel treatment activities that treat more area on the landscape, whether through mechanical and hand thinning or prescribed fire, dramatically lower the fire probability in the region and lead to a corresponding lower risk of property loss. We estimate that relative to recent practices of focusing management in the wildland–urban interface, more active forest management can reduce property loss risk by 45%–76%, or approximately 2600–4900 properties. The majority of this risk reduction is for single family residences, which constitute most structures in the region. Further, we find that the highest risk reduction is obtained through strategies that treat a substantially greater area than is currently treated in the region and allows for selective wildfires to burn for resource objectives outside of the wildland–urban interface. These results highlight the importance of more active forest management as an effective tool in reducing the wildfire risk to capital assets in the region.
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