1,137 research outputs found
Geography in the United Kingdom
Geography in school education A useful litmus test of the state of geography in formal education in England, Scotland, Northern Ireland and Wales is the examination results in recent years. The picture of declining interest in geography, as seen in the numbers opting to study it post 14, is worrying but there are some encouraging new initiatives by Government agencies and subject bodies that may help to stabilise the trend over the next five years or so. Almost all pupils are required to stud..
X-ray imaging of the Seyfert 2 galaxy Circinus with Chandra
We present results from the zeroth-order imaging of a Chandra HETGS
observation of the nearby Seyfert 2 galaxy Circinus. Twelve X-ray sources were
detected in the ACIS-S image of the galaxy, embedded in diffuse X-ray emission.
The latter shows a prominent (~18arcsec) soft ``plume'' in the N-W direction,
coincident with the [OIII] ionization cone. The radial profiles of the
brightest X-ray source at various energies are consistent with an unresolved
(FWHM ~0.8arcsec) component, which we identify as the active nucleus, plus two
extended components with FWHMs ~ 2.3arcsec and 18arcsec, respectively. In a
radius of 3arcsec, the nucleus contributes roughly the same flux as the
extended components at the softest energies (< 2 keV). However, at harder
energies (> 2 keV), the contribution of the nucleus is dominant. The
zeroth-order ACIS spectrum of the nucleus exhibits emission lines at both soft
and hard X-rays, including a prominent Fe Kalpha line at 6.4 keV, showing that
most of the X-ray lines previously detected with ASCA originate in a compact
region (<15 pc). Based on its X-ray spectrum, we argue that the 2.3arcsec
extended component is scattered nuclear radiation from nearby ionized gas. The
large-scale extended component includes the emission from the N-W plume and
possibly from the outer starburst ring.Comment: Figure 1 in color. ApJ Letters, in pres
Optics-less smart sensors and a possible mechanism of cutaneous vision in nature
Optics-less cutaneous (skin) vision is not rare among living organisms,
though its mechanisms and capabilities have not been thoroughly investigated.
This paper demonstrates, using methods from statistical parameter estimation
theory and numerical simulations, that an array of bare sensors with a natural
cosine-law angular sensitivity arranged on a flat or curved surface has the
ability to perform imaging tasks without any optics at all. The working
principle of this type of optics-less sensor and the model developed here for
determining sensor performance may be used to shed light upon possible
mechanisms and capabilities of cutaneous vision in nature
Use of stereotypical mutational motifs to define resolution limits for the ultra-deep resequencing of mitochondrial DNA.
Massively parallel resequencing of mitochondrial DNA (mtDNA) has led to significant advances in the study of heteroplasmic mtDNA variants in health and disease, but confident resolution of very low-level variants ( C, from patient with MNGIE, mitochondrial neurogastrointestinal encephalomyopathy) and comparing mutational pattern distribution with healthy mtDNA by ligation-mediated deep resequencing (Applied Biosystems SOLiD). We empirically derived mtDNA-mutant heteroplasmy detection limits, demonstrating that the presence of stereotypical mutational motif could be statistically validated for heteroplasmy thresholds ≥ 0.22% (P = 0.034). We therefore provide empirical evidence from biological samples that very low-level mtDNA mutants can be meaningfully resolved by massively parallel resequencing, confirming the utility of the approach for studying somatic mtDNA mutation in health and disease. Our approach could also usefully be employed in other settings to derive platform-specific deep resequencing resolution limits
Bioinformatics analysis of immune response to group A streptococcal sepsis integrating quantitative trait loci mapping with genome-wide expression studies
Characterization of Coelomic Fluid Cell Types in the Starfish Marthasterias glacialis Using a Flow Cytometry/Imaging Combined Approach
Funding: To the “Maristem COST Action” (CA16203), supported by COST (European Cooperation in Science and Technology), for funding PM STSM visits (February 2019 and November 2020) to the AVC Laboratory.Coelomocytes is the generic name for a collection of cellular morphotypes, present in many coelomate animals, and highly variable among echinoderm classes. The roles attributed to the major types of these free circulating cells present in the coelomic fluid of echinoderms include immune response, phagocytic digestion and clotting. Our main aim in this study was to characterize coelomocytes found in the coelomic fluid of Marthasterias glacialis (class Asteroidea) by using a combination of flow cytometry (FC), imaging flow cytometry (IFC) and fluorescence plus transmission electron microscopy (TEM). Two coelomocyte populations (P1 and P2) identified through flow cytometry were subsequently studied in terms of abundance, morphology, ultrastructure, cell viability and cell cycle profiles. Ultrastructurally, P2 diploid cells were present as two main morphotypes, similar to phagocytes and vertebrate thrombocytes, whereas the smaller P1 cellular population was characterized by low mitotic activity, a relatively undifferentiated cytotype and a high nucleus/cytoplasm ratio. In the present study we could not rule out possible similarities between haploid P1 cells and stem-cell types in other animals. Additionally, we report the presence of two other morphotypes in P2 that could only be detected by fluorescence microscopy, as well as a morphotype revealed via combined microscopy/FC. This integrative experimental workflow combined cells physical separation with different microscopic image capture technologies, enabling us to better tackle the characterization of the heterogeneous composition of coelomocytes populations.publishersversionpublishe
Accessibility, sustainability, excellence: How to expand access to research publications. Executive summary
This article is a summary, by the authors, of a 140-page report prepared in 2012 by the UK Working Group on Expanding Access to Published Research Findings, chaired by British sociologist and academic administrator Janet Finch, DBE. The Working Group was charged with recommending how to develop a model that would be effective and sustainable over time, for expanding access to the published fi ndings of research. The whole report, which can be accessed at http://www.researchinfonet.org/wp-content/uploads/2012/06/Finch-Group-report-FINAL-VERSION.pdf [http://tinyurl.com/d2lxqks], has been published under a Creative Commons License Attribution 3.0 Unported. This is the fi rst of a series of Perspectives articles devoted to the Open Access Initiative that will be published in INTERNATIONAL MICROBIOLOGY. Our journal already published an Editorial on the topic in 2004 (Guerrero R & Piqueras M, Int Microbiol 7:157-161), and strongly supports open access. [Int Microbiol 2013; 16(2):125-132
Accessibility, sustainability, excellence: how to expand access to research publications. Executive summary
This article is a summary, by the authors, of a 140-page report prepared in 2012 by the UK Working Group on Expanding Access to Published Research Findings, chaired by British sociologist and academic administrator Janet Finch, DBE. The Working Group was charged with recommending how to develop a model that would be effective and sustainable over time, for expanding access to the published fi ndings of research. The whole report, which can be accessed at http://www.researchinfonet.org/wp-content/uploads/2012/06/Finch-Group-report-FINAL-VERSION.pdf [http://tinyurl.com/d2lxqks], has been published under a Creative Commons License Attribution 3.0 Unported. This is the fi rst of a series of Perspectives articles devoted to the Open Access Initiative that will be published in INTERNATIONAL MICROBIOLOGY. Our journal already published an Editorial on the topic in 2004 (Guerrero R & Piqueras M, Int Microbiol 7:157-161), and strongly supports open access. [Int Microbiol 2013; 16(2):125-132
Loss of Biological Diversity: A Global Crisis Requiring International Solutions: A Report to the National Science Board
Executive Summary
Biological diversity refers to the variety and variability among living organisms and the ecological complexes in which they occur. Diversity can be defined as the number of different items and their relative frequency. For biological diversity, these items are organized at many levels, ranging from complete ecosystems to the chemical structures that are the molecular basis of heredity. Thus, the term encompasses different ecosystems, species, genes, and their relative abundance (OTA, 1987).
There is an ongoing, unprecedented loss of the variety as well as absolute numbers of organisms-from the smallest microorganism to the largest and most spectacular of mammals. Loss of tropical moist forests, which contain over half the total species of organisms, has been well documented by scientists and is now widely reported in the media. Many other ecosystems are also threatened; as human populations and their support systems expand, natural ecosystems at all latitudes are altered or converted.
At its meeting on October 15, 1987, the National Science Board concluded that the world\u27s decreasing biological diversity is a critical scientific issue requiring immediate attention. The National Science Board\u27s Committee on International Science was asked to study the scientific and international aspects of the decline of biological diversity and to recommend a course of action. This report describes what the National Science Foundation (NSF) can do to influence the U.S. science and education base, articulates where international scientific cooperation is needed, and suggests roles for other agencies and organizations (both national and international) which have scientific, educational, and management responsibilities.
The current disappearance of biota has several causes: the destruction or degradation of entire ecosystems; the accelerating loss of individual species from communities or ecosystems as a result of human disturb;mce; and the loss of genetically distinct parts of populations due to human-induced selective pressures. Although not all parts of the planet are equally affected, the problem is global, and human activities are the primary cause.
The loss of biological diversity is important because human existence depends on the biological resources of 1 the earth. Human prosperity is based very largely on the ability to utilize biological diversity: to take advantage of the properties of plants, animals, fungi, and microorganisms for food, clothing, medicine, and shelter.
Scientific knowledge about the earth\u27s biological diversity has huge gaps. This lack of information hampers society\u27s ability either to estimate the magnitude of the problem or to prevent further losses. It is impossible to identify all the biological resources at risk, since there is no complete inventory of all the life forms on earth. Approximately 1.4 million species have been given scientific names, but estimates of actual numbers range from 5 million to 80 million species. Although knowledge of some taxa is extensive, the vast majority of groups are largely unknown. The current wave of extinction is destroying both known biotic resources and those still undiscovered.
As is proving to be the case with most environmental problems, neither the loss of biological diversity nor its solution is the exclusive province of any one nation. International cooperation is necessary to develop both scientific knowledge and successful mitigation and management strategies. The root causes of the problem include sociological and economic processes which operate on an global scale; a thorough understanding will require investigation and elucidation of both biological and non-biological components.
There are several reasons for increasing National Science Foundation (NSF) involvement in biodiversity studies: the economic and social importance of biodiversity (and the risk of opportunity lost due to accelerating extinction); the contributions such leadership can make toward to conservation of biological diversity; the important role of such studies in the international growth of science, especially in tropical countries; the potential impact of such studies on the future course of biology as a whole; and enhancing public awareness of the issues.
NSF should assume a scientific leadership position with respect to agencies in the U.S. and throughout the world. By insisting on the central importance of biodiversity, the NSF could encourage collaborative support for the actions recommended below.
1. The Committee believes that the role of the NSF is clear-NSF should, as a matter of National Science Board Policy, provide leadership to undertake the inventory of the world\u27s biodiversity.
2. The scientific basis for conservation biology, restoration ecology, and environmental management must be strengthened.
3. Educational and public awareness programs related to biodiversity need increased support.
4. The economic and social aspects of the biodiversity crisis need additional study.
5. Enhance support for developing country scientists and institutions for biodiversity research and conservation
An Unbiased Systems Genetics Approach to Mapping Genetic Loci Modulating Susceptibility to Severe Streptococcal Sepsis
Striking individual differences in severity of group A streptococcal (GAS) sepsis have been noted, even among patients infected with the same bacterial strain. We had provided evidence that HLA class II allelic variation contributes significantly to differences in systemic disease severity by modulating host responses to streptococcal superantigens. Inasmuch as the bacteria produce additional virulence factors that participate in the pathogenesis of this complex disease, we sought to identify additional gene networks modulating GAS sepsis. Accordingly, we applied a systems genetics approach using a panel of advanced recombinant inbred mice. By analyzing disease phenotypes in the context of mice genotypes we identified a highly significant quantitative trait locus (QTL) on Chromosome 2 between 22 and 34 Mb that strongly predicts disease severity, accounting for 25%–30% of variance. This QTL harbors several polymorphic genes known to regulate immune responses to bacterial infections. We evaluated candidate genes within this QTL using multiple parameters that included linkage, gene ontology, variation in gene expression, cocitation networks, and biological relevance, and identified interleukin1 alpha and prostaglandin E synthases pathways as key networks involved in modulating GAS sepsis severity. The association of GAS sepsis with multiple pathways underscores the complexity of traits modulating GAS sepsis and provides a powerful approach for analyzing interactive traits affecting outcomes of other infectious diseases
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