2,033 research outputs found
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High-speed Developments in Avian Genomics
Until recently, definitions of avian genome structure and function were based solely on our knowledge of the chicken genome. The expansion of genomic studies to include nonmodel avian species allows us not only to refine those definitions but also to begin collecting the necessary resources to initiate a truly ecological genomics of birds. In this article we review new genomic technologies that will speed up the investigation of avian genome function. The streamlined nature of avian genomes implies that large-scale transcriptional analyses, studies of the role of regulatory elements and of developmental genes, and even the annotation of avian genomes will yield interesting surprises. We review promising methods used to investigate genome evolution in birds as well as the means by which to integrate functional genomics approaches and transcriptional profiling information into ecological and evolutionary studies.Organismic and Evolutionary Biolog
When perceptions are deadly: Policing, given the summer in Ferguson, Missouri and other similar stories, before and since
When law enforcement officers, regardless of race and ethnicity, are exposed to messages of Black violence, these perceptions of danger can become deadly. In 2014, the Michael Brown case in Ferguson, Missouri elevated this concern; but, there were many other cases previously publicized in the media such as Amadou Diallo, and Sean Bell. Using a content analysis of news reports from 1994 to summer 2015, this paper offers an assessment of media influence in the construction of public perceptions of Black dangerousness that seems to impact Black male and law enforcement interactions that become deadly for the former. The study also describes the local police-community contexts where such interactions seem likely. Patterns of contact and police narratives across a number of high profile police and Black male interactions are described. Noting these patterns, suggestions are offered toward creating a path for constructively addressing the problem of news-generated perceptions that can lead to needless tragedy for some. Community disempowerment and divergent community perspectives of law enforcement are often evident in these cases. This study is thus, an effort at enhancing awareness of modern-day news-perpetuated perceptions linking crime and Blackness
Adaptive strategies of African horse sickness virus to facilitate vector transmission
African horse sickness virus (AHSV) is an orbivirus that is usually transmitted between its equid hosts by adult Culicoides midges. In this article, we review the ways in which AHSV may have adapted to this mode of transmission. The AHSV particle can be modified by the pH or proteolytic enzymes of its immediate environment, altering its ability to infect different cell types. The degree of pathogenesis in the host and vector may also represent adaptations maximising the likelihood of successful vectorial transmission. However, speculation upon several adaptations for vectorial transmission is based upon research on related viruses such as bluetongue virus (BTV), and further direct studies of AHSV are required in order to improve our understanding of this important virus
How to create analogue black hole or white fountain horizons and LASER cavities in experimental free surface hydrodynamics?
Transcritical flows in free surface hydrodynamics emulate black hole horizons
and their timereversed versions known as white fountains. Both analogue
horizons have been shown to emit Hawking radiation, the amplification of waves
via scattering at the horizon. Here we report on an experimental validation of
the hydrodynamic laws that govern transcritical flows, for the first time in a
free surface water channel using an analogue space-time geometry controlled by
a bottom obstacle. A prospective study, both experimental and numerical, with a
second obstacle downstream of a first one is presented to test in the
near-future the analogous black hole laser instability, namely the
super-amplification of Hawking radiation by successive bounces on a pair of
black and white horizons within cavities which allow the presence of negative
energy modes necessary for the amplification process. Candidate hydrodynamic
regimes are discussed thanks to a phase diagram based on the scaled relative
heights of both obstacles and the ratio of flow to wave speed in the upstream
region.Comment: 19 pages, 19 figure
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Innate Immunity and the Evolution of Resistance to an Emerging Infectious Disease in a Wild Bird
Innate immunity is expected to play a primary role in conferring resistance to novel infectious diseases, but few studies have attempted to examine its role in the evolution of resistance to emerging pathogens in wild vertebrate populations. Here, we used experimental infections and cDNA microarrays to examine whether changes in the innate and/or acquired immune responses likely accompanied the emergence of resistance in house finches (Carpodacus mexicanus) in the eastern United States subject to a recent outbreak of conjunctivitis-causing bacterium (Mycoplasma gallisepticum—MG). Three days following experimental infection with MG, we observed differences in the splenic transcriptional responses between house finches from eastern U.S. populations, with a 12-year history of MG exposure, versus western U.S. populations, with no history of exposure to MG. In particular, western birds down-regulated gene expression, while eastern finches showed no expression change relative to controls. Studies involving poultry have shown that MG can manipulate host immunity, and our observations suggest that pathogen manipulation occurred only in finches from the western populations, outside the range of MG. Fourteen days after infection, eastern finches, but not western finches, up-regulated genes associated with acquired immunity (cell-mediated immunity) relative to controls. These observations suggest population differences in the temporal course of the response to infection with MG and imply that innate immune processes were targets of selection in response to MG in the eastern U.S. population.Organismic and Evolutionary Biolog
Automorphisms of graphs of cyclic splittings of free groups
We prove that any isometry of the graph of cyclic splittings of a finitely
generated free group of rank is induced by an outer automorphism
of . The same statement also applies to the graphs of maximally-cyclic
splittings, and of very small splittings.Comment: 22 pages, 5 figures. Small modifications. To appear in Geometriae
Dedicat
Establishing Telepathology in Africa: Lessons From Botswana
Few reports of telepathology in Africa exist in the medical literature. With the strong need for improvement in health care infrastructure and personnel training in many African nations, telepathology provides a rapid and versatile tool to improve clinical care and foster educational and research opportunities. We describe the challenges faced in establishing robotic telepathology (RT) services at a government referral center in Botswana and reflect on conditions under which such initiatives may be most likely to succeed in sub-Saharan Africa and other parts of the developing world
Patient experience of care in a student-faculty collaborative practice
Student Run Clinics (SRCs) are a popular means of caring for the underserved while providing valuable medical education opportunities. Reports of patient experience surveys are rare in this setting. This is troublesome because it is possible that underserved patients, who are more likely to receive care at SRCs, are not receiving the same level of care as at more traditional medical practices. The purpose of this research was to measure patient experience in a student-led medical clinic. The method included the use of patient experience surveys, which were self-administered pre-visit and self- and interviewer administered post-visit. The key results, 100% of patients felt treated with respect. 81.4% of patients would “definitely” and 16.3% would “somewhat” refer their family and friends to the clinic. 87% reported being seen within 15 minutes of their appointment time; 60% reported that they knew they would be seen by medical students and a doctor. This data has been useful to our student-led clinic in streamlining clinic flow, reducing wait times and building awareness of our structure. Our hope is this study will encourage others SRCs to adopt similar student-faculty collaborative research based practices to enhance care for SRC patients while teaching students to use patient feedback to improve quality of care
Ecological resilience indicators for salt marsh ecosystems
Salt marshes are coastal ecosystems within the intertidal zone, characterized by hypoxic, saline, soil conditions and low biodiversity. Low diversity arises from frequent disturbance and stressful conditions (i.e., high salinity and hypoxia), where vegetative reproduction and low competition result in mostly monotypic stands, with some differences in plant community influenced by flooding regime (described below). While there are several types of salt marshes in the Northern Gulf of Mexico (NGoM), ranging from low to high salt marshes and salt flats (Tiner, 2013), Spartina alterniflora–dominated salt marshes in the Coastal and Marine Ecological Classification Standard (CMECS) Low and Intermediate Salt Marsh Biotic Group (FGDC, 2012) are the most extensive and are the focus of this project. These salt marshes are classified as “Gulf Coast Cordgrass Salt Marsh” (CEGL004190; USNVC, 2016). Within the NGoM region, some salt marsh areas are dominated by other species such as Spartina patens and Juncus roemerianus, which both occupy higher elevations in high-precipitation zones (e.g., Louisiana, Alabama, Mississippi, and Florida). In lower precipitation regions (southern Texas), hypersaline conditions often develop yielding communities of succulent salt marsh plants (Batis and Salicornia spp.). In climatic zones with warmer winter temperatures, temperate salt marshes naturally transition to mangrove (generally in the southern Gulf of Mexico range) or, in areas with lower precipitation, to salt flats (generally in western part of the study area)
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