615 research outputs found
Advancing integrative âone-healthâ approaches to global health through multidisciplinary, faculty-led global health field courses
AbstractBackgroundSince 2003, the University of Wisconsin-Madison Global Health Institute, together with collaborating campus and in-country partners, has offered immersive, multidisciplinary, faculty-led, global health field courses in Ecuador and Thailand. These courses aim to help students to develop a working understanding of integrative one-health approaches and acquire the skills to work effectively across disciplines. That is, we aim to foster an appreciation of the role of culture in perceptions of health, disease, and health care; the complex interactions of animal-human-ecosystem health and disease; and the value of integrating cross-disciplinary and cross-cultural perspectives and skills to solve complex public health problems.MethodsStudents from various University of Wisconsin-Madison health faculties travelled, lived (accommodation included homestays in indigenous or rural communities), learnt, and engaged in community-health assessments or service-learning projects as a multidisciplinary team. We recruited students through annual presentations in each University of Wisconsin school or college and through recommendations from past participants. We recorded student reflections during the course, at course completion, and after graduation.FindingsBetween 2003 and 2014: 215 students from the University of Wisconsin have taken part in the global health field courses. Students came from the fields of human medicine (53 [25%]), veterinary medicine (35 [16%]), nursing (40 [19%]), pharmacy (41 [19%]), and other degree programs (46 [21%]). Results of the in-course and post course assessments consistently show strong student satisfaction with many aspects of the programme, including safety, faculty mentorship, the value of the multidisciplinary approach, depth of learning, and programme cost. Former participants also report use of cross-cultural skills in their professional practice, work with populations from cultures other than their own, positive effects on their decisions for career activities, and the belief that immersive cross-cultural experiences should be a required part of professional training for all health professional students. Finally, the courses undergo independent programme evaluations (including in-country observation and interviews with participants and stakeholders) approximately every 5 years.InterpretationProgramme directors continue to seek improvements related to: sustainable faculty engagement from various disciplines; development of increasingly specific course group learning objectives, competencies, and assessment tools; sustainability of impacts on community-level health and wellbeing; continuity between University of Wisconsin-Madison and in-country university and community partners; and scholarship support and other approaches so that cost does not exclude interested students from participating.FundingThe GHI is supported through a combination of university, grants, and philanthropic funding; these field courses do not have specific, separate funding. Students self-fund participation in the courses
Ecosystem effects of thermal manipulation of a whole lake, Lake BreisjĂžen, southern Norway (THERMOS project)
International audienceWe conducted a 3-year artificial deepening of the thermocline in the dimictic Lake BreisjĂžen, southern Norway, by means of a large submerged propeller. An adjacent lake served as untreated reference. The manipulation increased thermocline depth from 6 to 20 m, caused a significant increase in the heat content, and delayed ice-on by about 20 days. There were only minor changes in water chemistry. Concentrations of sulphate declined, perhaps due to greater reduction of sulphate at the sediment-water interface. Concentrations of particulate carbon and nitrogen decreased, perhaps due to increased sedimentation velocity. Water transparency increased. There was no significant change in concentration of phosphorus, the growth-limiting nutrient. There were few significant changes in principal biological components. Phytoplankton biomass and productivity did not change, although the chlorophyll-a concentration showed a small decrease. Phytoplankton species richness increased, and the species composition shifted. Growth of periphyton increased. There was no change in the macrophyte community. The manipulation did not affect the zooplankton biodiversity, but caused a significant shift in the relative abundance (measured as biomass) in the two major copepod species. The manipulation did not affect the individual density, but appeared to have changed the vertical distribution of zoobenthos. Fish populations were not affected. The lake is oligotrophic and clearwater and the manipulation did not change the supply of phosphorus, and thus there were only minor changes in lake chemistry and biology. Effects might be larger in eutrophic and dystrophic lakes in which internal processes are stronger
Improved analysis of bacterial CGH data beyond the log-ratio paradigm
<p>Abstract</p> <p>Background</p> <p>Existing methods for analyzing bacterial CGH data from two-color arrays are based on log-ratios only, a paradigm inherited from expression studies. We propose an alternative approach, where microarray signals are used in a different way and sequence identity is predicted using a supervised learning approach.</p> <p>Results</p> <p>A data set containing 32 hybridizations of sequenced versus sequenced genomes have been used to test and compare methods. A ROC-analysis has been performed to illustrate the ability to rank probes with respect to Present/Absent calls. Classification into Present and Absent is compared with that of a gaussian mixture model.</p> <p>Conclusion</p> <p>The results indicate our proposed method is an improvement of existing methods with respect to ranking and classification of probes, especially for multi-genome arrays.</p
Short-period AM CVn systems as optical, X-ray and gravitational wave sources
We model the population of AM CVn systems in the Galaxy and discuss the
detectability of these systems with optical, X-ray and gravitational wave
detectors. We concentrate on the short period (P < 1500 s) systems, some of
which are expected to be in a phase of direct impact accretion. Using a
self-consistent model for the star formation history and radial distribution of
stars in the Galaxy plus simple models for the emission of optical and X-ray
radiation from the AM CVn systems and interstellar absorption, we derive the
sample of short-period AM CVn systems that can be detected in the optical
and/or X-ray bands. At the shortest periods the detectable systems are all
X-ray sources, some with periods as short as three minutes. At periods above 10
minutes most detectable systems are optical sources. About one third of the
X-ray sources are also detectable in the optical band. We also calculate the
gravitational wave signal of the short-period AM CVn systems. We find that
potentially several thousand AM CVn systems can be resolved by the
gravitational wave detector LISA, comparable to the expected number of detached
double white dwarfs that can be resolved. We estimate that several hundreds of
the AM CVn systems resolvable by LISA, are also detectable in the optical
and/or X-ray bands.Comment: Accepted for publication in MNRA
Observations of the pulsating subdwarf B star Feige 48: Constraints on evolution and companions
Since pulsating subdwarf B (sdBV or EC14026) stars were first discovered
(Kilkenny et al, 1997), observational efforts have tried to realize their
potential for constraining the interior physics of extreme horizontal branch
(EHB) stars. Difficulties encountered along the way include uncertain mode
identifications and a lack of stable pulsation mode properties. Here we report
on Feige 48, an sdBV star for which follow-up observations have been obtained
spanning more than four years, which shows some stable pulsation modes.
We resolve the temporal spectrum into five stable pulsation periods in the
range 340 to 380 seconds with amplitudes less than 1%, and two additional
periods that appear in one dataset each. The three largest amplitude
periodicities are nearly equally spaced, and we explore the consequences of
identifying them as a rotationally split l=1 triplet by consulting with a
representative stellar model.
The general stability of the pulsation amplitudes and phases allows us to use
the pulsation phases to constrain the timescale of evolution for this sdBV
star. Additionally, we are able to place interesting limits on any stellar or
planetary companion to Feige 48.Comment: accepted for publication in MNRA
OSIRIS: A Decade of Scattered Light
Into year 11 of a 2-yr mission, OSIRIS is redefining how limb-scattered sunlight can be used to probe the atmosphere, even into the upper troposphere
The WSO, a world-class observatory for the ultraviolet
The World Space Observatory is an unconventional space project proceeding via distributed studies. The present design, verified for feasibilty, consists of a 1.7-meter telescope operating at the second Largangian point of the Earth-Sun system. The focal plane instruments consist of three UV spectrometers covering the spectral band from Lyman alpha to the atmospheric cutoff with R~55,000 and offering long-slit capability over the same band with R~1,000. In addition, a number of UV and optical imagers view adjacent fields to that sampled by the spectrometers. Their performance compares well with that of HST/ACS and the spectral capabilities of WSO rival those of HST/COS
Resolving the ancestry of Austronesian-speaking populations
There are two very different interpretations of the prehistory of Island Southeast Asia (ISEA), with genetic evidence invoked in support of both. The âout-of-Taiwanâ model proposes a major Late Holocene expansion of Neolithic Austronesian speakers from Taiwan. An alternative, proposing that Late Glacial/postglacial sea-level rises triggered largely autochthonous dispersals, accounts for some otherwise enigmatic genetic patterns, but fails to explain the Austronesian language dispersal. Combining mitochondrial DNA (mtDNA), Y-chromosome and genome-wide data, we performed the most comprehensive analysis of the region to date, obtaining highly consistent results across all three systems and allowing us to reconcile the models. We infer a primarily common ancestry for Taiwan/ISEA populations established before the Neolithic, but also detected clear signals of two minor Late Holocene migrations, probably representing Neolithic input from both Mainland Southeast Asia and South China, via Taiwan. This latter may therefore have mediated the Austronesian language dispersal, implying small-scale migration and language shift rather than large-scale expansion
Multibeam bathymetric surveys of submarine volcanoes and mega-pockmarks on the Chatham Rise, New Zealand
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Taylor & Francis for personal use, not for redistribution. The definitive version was published in New Zealand Journal of Geology and Geophysics 54 (2011): 329-339, doi:10.1080/00288306.2011.589860.Multibeam bathymetric surveys east of the South Island of New Zealand present images of submarine volcanoes and pockmarks west of Urry Knolls on the Chatham Rise, and evidence of submarine erosion on the southern margin of the Chatham Rise. Among numerous volcanic cones, diameters of the largest reach ~2000 m, and some stand as high as 400 m above the surrounding seafloor. The tops of most of the volcanic cones are flat, with hints of craters, and some with asymmetric shapes may show flank collapses. There are hints of both northeast-southwest and northwest-southeast alignments of volcanoes, but no associated faulting is apparent. Near and to the west of these volcanoes, huge pockmarks, some more than ~1 km in diameter, disrupt bottom topography. Pockmarks in this region seem to be confined to sea floor shallower than ~1200 m, but we see evidence of deeper pockmarks at water depths of up to 2100 m on profiles crossing the Bounty Trough. The pockmark field on the Chatham Rise seems to be bounded on the south by a trough near 1200 m depth; like others, we presume that contour currents have eroded the margin and created the trough.This research was supported by the National Science Foundation under grants EAR-0409564, EAR-0409609, and EAR-0409835.2012-08-3
Dimensionless cosmology
Although it is well known that any consideration of the variations of
fundamental constants should be restricted to their dimensionless combinations,
the literature on variations of the gravitational constant is entirely
dimensionful. To illustrate applications of this to cosmology, we explicitly
give a dimensionless version of the parameters of the standard cosmological
model, and describe the physics of Big Bang Neucleosynthesis and recombination
in a dimensionless manner. The issue that appears to have been missed in many
studies is that in cosmology the strength of gravity is bound up in the
cosmological equations, and the epoch at which we live is a crucial part of the
model. We argue that it is useful to consider the hypothetical situation of
communicating with another civilization (with entirely different units),
comparing only dimensionless constants, in order to decide if we live in a
Universe governed by precisely the same physical laws. In this thought
experiment, we would also have to compare epochs, which can be defined by
giving the value of any {\it one} of the evolving cosmological parameters. By
setting things up carefully in this way one can avoid inconsistent results when
considering variable constants, caused by effectively fixing more than one
parameter today. We show examples of this effect by considering microwave
background anisotropies, being careful to maintain dimensionlessness
throughout. We present Fisher matrix calculations to estimate how well the fine
structure constants for electromagnetism and gravity can be determined with
future microwave background experiments. We highlight how one can be misled by
simply adding to the usual cosmological parameter set
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