1,501 research outputs found
In Situ Method of Measuring Atmosphere Neutral Winds with a Rigid Falling Sphere
The new falling sphere instruments will measure lower E-region winds and density, which are critical for many of the electrodynamics and plasma physics studies that are carried out as part of the NASA suborbital rocket program. The new falling sphere design will take advantage of modern commercially available electronic components and materials. Of primary importance, it is proposed to fly an in-situ instrument that targets the measurement of neutral wind profiles over the altitude range from 80 to 150 km, with accuracy better than that achieved in previous implementations of the falling sphere technique and those typically obtained with the chemical release technique. The falling sphere instrument will measure the lower E-region winds and density, which are critical for many of the electrodynamics and plasma physics studies that are carried out as part of the NASA Geospace suborbital rocket program. This gives a report of the overall design and the rigid body dynamics involved as well as some post flight analysis
Diagnostic odyssey for rare diseases: exploration of potential indicators
To explore whether an accurate, robust and cost-effective method can be developed for the routine measurement of the rare diseases diagnostic odysseys to enable the impact of interventions and policies, such as the 2013 UK Strategy for Rare Diseases, to be evaluated
Magnetic states of linear defects in graphene monolayers: effects of strain and interaction
The combined effects of defect-defect interaction and of uniaxial or biaxial
strains of up to 10\% on the development of magnetic states on the
defect-core-localized quasi-one-dimensional electronic states generated by the
so-called 558 linear extended defect in graphene monolayers are investigated by
means of {\it ab initio} calculations. Results are analyzed on the basis of the
heuristics of the Stoner criterion. We find that conditions for the emergence
of magnetic states on the 558 defect can be tuned by uniaxial tensile parallel
strains (along the defect direction) at both limits of isolated and interacting
558 defects. Parallel strains are shown to lead to two cooperative effects that
favor the emergence of itinerant magnetism: enhancement of the DOS of the
resonant defect states in the region of the Fermi level and tuning of the Fermi
level to the maximum of the related DOS peak. A perpendicular strain is
likewise shown to enhance the DOS of the defect states, but it also effects a
detunig of the Fermi level that shifts away from the maximum of the DOS of the
defect states, which inhibts the emergence of magnetic states. As a result,
under biaxial strains the stabilization of a magnetic state depends on the
relative magnitudes of the two components of strain.Comment: 9 pages 8 figure
320g Ionization-Heat Cryogenic Detector for Dark Matter Search in the EDELWEISS Experiment
The EDELWEISS experiment used in 2001 a 320g heat-and-ionization cryogenic Ge
detector operated in a low-background environment in the Laboratoire Souterrain
de Modane for direct WIMP detection. This detector presents an increase of more
than 4 times the mass of previous detectors. Calibrations of this detector are
used to determine its energy resolution and fiducial volume, and to optimize
the detector design for the 1kg phase of the EDELWEISS-I experiment. Analysis
of the calibrations and characteristics of a first series of 320g-detectors are
presented.Comment: 4 pages, 3 figure
The Effects of Gravitational Back-Reaction on Cosmological Perturbations
Because of the non-linearity of the Einstein equations, the cosmological
fluctuations which are generated during inflation on a wide range of
wavelengths do not evolve independently. In particular, to second order in
perturbation theory, the first order fluctuations back-react both on the
background geometry and on the perturbations themselves. I this paper, the
gravitational back-reaction of long wavelength (super-Hubble) scalar metric
fluctuations on the perturbations themselves is investigated for a large class
of inflationary models. Specifically, the equations describing the evolution of
long wavelength cosmological metric and matter perturbations in an inflationary
universe are solved to second order in both the amplitude of the perturbations
and in the slow roll expansion parameter. Assuming that the linear fluctuations
have random phases, we show that the fractional correction to the power
spectrum due to the leading infrared back-reaction terms does not change the
shape of the spectrum. The amplitude of the effect is suppressed by the product
of the inflationary slow-roll parameter and the amplitude of the linear power
spectrum. The non-gaussianity of the spectrum induced by back-reaction is
commented upon.Comment: 9 page
Swine influenza surveillance in East and Southeast Asia: a systematic review
East and Southeast Asia are important pig- and poultry-producing areas, where the majority of production takes place on small-scale farms with low biosecurity levels. This systematic review synthesizes data on swine influenza virology, serology and epidemiology in East and Southeast Asia. A total of 77 research articles, literature reviews and conference papers were selected and analyzed from 510 references retrieved from PubMed and ISI Web of KnowledgeSM. The number of published articles increased in the last 3 years, which may be attributed to improvement in monitoring and/or a better promotion of surveillance data. Nevertheless, large inequalities in surveillance and research among countries are underlined. Virological results represent the largest part of published data, while the serological and epidemiological features of swine influenza in East and Southeast Asia remain poorly described. The literature shows that there have been several emergences of swine influenza in the region, and also considerable evidence of multiple introductions of North American and avian-like European strains. Furthermore, several avian-origin strains are isolated from pigs, including H5 and H9 subtypes. However, their low seroprevalence in swine also shows that pigs remain poorly infected by these subtypes. We conclude that sero-epidemioligical investigations have been neglected, and that they may help to improve virological surveillance. Inter- and intra-continental surveillance of gene flows will benefit the region. Greater investment is needed in swine influenza surveillance, to improve our knowledge of circulating strains as well as the epidemiology and disease burden in the region.published_or_final_versio
Cellular and Cytokine Responses in the Granulomas of Asymptomatic Cattle naturally infected with Mycobacterium bovis in Ethiopia
Cells (CD3+ T cell and CD68+ macrophages), cytokines (IFN-γ+ and TNF-α+) and effector molecule (iNOS+) responses were evaluated in the lymph nodes and tissue of cattle naturally infected with Detailed post mortem and immunohistochemical examinations of lesions were performed on 16 cows positive for single intradermal cervical comparative tuberculin (SICCT) test which were identified from dairy farms located around the Addis Ababa City. The severity of the gross lesion was significantly higher (p=0.003) in culture positive (n=12) cows than in culture negative (n=4). Immunohistochemical techniques showed that in culture positive cows, the mean immunolabeling fraction of CD3+ T cells decreased as the stage of granuloma increased from stage I to stage IV (p<0.001). In contrast, the immunolabelling fraction of CD68+ macrophages, IFN-γ+, TNF-α+ and iNOS+ increased from stage I to stage IV (p< 0.001). In culture negative cows, early stages showed a significantly higher fraction of CD68+ macrophages (p=0.03) and iNOS+ (p=0.007) when compared to culture positive cows. Similarly, at advanced granuloma stages, culture negative cows demonstrated significantly higher mean proportions of CD3+ T cells (p< 0.001) compared to culture positive cows. Thus, this study demonstrates that following natural infection of cows with , as the stage of granuloma increases from stage I to stage IV, the immunolabelling fraction of CD3+ cells decreases while the immunolabeling fraction of CD68+ macrophages, IFN-γ+, TNF-α+ and iNOS+ increases. [Abstract copyright: Copyright © 2020 Tulu et al.
Functional morphological imaging of autism spectrum disorders: Current position and theories proposed
AbstractAutism is a pervasive disorder of childhood development. Polymorphous clinical profiles combining various degrees of communication and social interaction with restricted and stereotyped behaviour are grouped under the heading of âautism spectrum disordersâ (ASD). Many teams are trying to pick out the underlying cerebral abnormalities in order to understand the neuronal networks involved in relationships with others. Here we review the morphological, spectroscopic and functional abnormalities in the amygdala-hippocampal circuit, the caudate nuclei, the cerebellum, and the frontotemporal regions, which have been described in subjects with ASD. White matter abnormalities have also been described in diffusion tensor imaging, leading to suspected damage to the subjacent neural networks, such as mirror neurones or the social brain
Micronutrients to Support Vaccine Immunogenicity and Efficacy
The world has entered the third year of the coronavirus disease 2019 (COVID-19) pan-demic. Vaccination is the primary public health strategy to protect against infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in addition to other measures, such as mask wearing and social distancing. Vaccination has reduced COVID-19 severity and mortality dramatically. Nevertheless, incidence globally remains high, and certain populations are still at risk for severe outcomes. Additional strategies to support immunity, including potentially enhancing the response to vaccination, are needed. Many vitamins and trace minerals have recognized immunomodulatory actions, and their status and/or supplementation have been reported to corre-spond to the incidence and severity of infection. Furthermore, a variety of observational and some interventional studies report that adequate micronutrient status or micronutrient supplementation is associated with enhanced vaccine responses, including to COVID-19 vaccination. Such data suggest that micronutrient supplementation may hold the potential to improve vaccine immunogenicity and effectiveness, although additional interventional studies to further strengthen the existing evidence are needed. Positive findings from such research could have important implications for global public health, since deficiencies in several micronutrients that support immune function are prevalent in numerous settings, and supplementation can be implemented safely and inexpensively
- âŠ