733 research outputs found
Historical reviews of the assessment of human cardiovascular function: interrogation and understanding of the control of skin blood flow.
Several techniques exist for the determination of skin blood flow that have historically been used in the investigation of thermoregulatory control of skin blood flow, and more recently, in clinical assessments or as an index of global vascular function. Skin blood flow measurement techniques differ in their methodology and their strengths and limitations. To examine the historical development of techniques for assessing skin blood flow by describing the origin, basic principles, and important aspects of each procedure and to provide recommendations for best practise. Venous occlusion plethysmography was one of the earliest techniques to intermittently index a limb's skin blood flow under conditions in which local muscle blood flow does not change. The introduction of laser Doppler flowmetry provided a method that continuously records an index of skin blood flow (red cell flux) (albeit from a relatively small skin area) that requires normalisation due to high site-to-site variability. The subsequent development of laser Doppler and laser speckle imaging techniques allows the mapping of skin blood flow from larger surface areas and the visualisation of capillary filling from the dermal plexus in two dimensions. The use of iontophoresis or intradermal microdialysis in conjunction with laser Doppler methods allows for the local delivery of pharmacological agents to interrogate the local and neural control of skin blood flow. The recent development of optical coherence tomography promises further advances in assessment of the skin circulation via three-dimensional imaging of the skin microvasculature for quantification of vessel diameter and vessel recruitment
Test beam Characterizations of 3D Silicon Pixel detectors
3D silicon detectors are characterized by cylindrical electrodes
perpendicular to the surface and penetrating into the bulk material in contrast
to standard Si detectors with planar electrodes on its top and bottom. This
geometry renders them particularly interesting to be used in environments where
standard silicon detectors have limitations, such as for example the radiation
environment expected in an LHC upgrade. For the first time, several 3D sensors
were assembled as hybrid pixel detectors using the ATLAS-pixel front-end chip
and readout electronics. Devices with different electrode configurations have
been characterized in a 100 GeV pion beam at the CERN SPS. Here we report
results on unirradiated devices with three 3D electrodes per 50 x 400 um2 pixel
area. Full charge collection is obtained already with comparatively low bias
voltages around 10 V. Spatial resolution with binary readout is obtained as
expected from the cell dimensions. Efficiencies of 95.9% +- 0.1 % for tracks
parallel to the electrodes and of 99.9% +- 0.1 % at 15 degrees are measured.
The homogeneity of the efficiency over the pixel area and charge sharing are
characterized.Comment: 5 pages, 7 figure
Comparing Mutuality and Solidarity in Its Application to Disaster Ethics
Often it has been observed that in disaster situations, people (including victims) become altruistic and are very willing to listen, obey and act in a manner that would help bring an end to the situation. In this chapter, linking disaster ethics and human rights, it is argued that this indeed is how it should be, disaster or otherwise, and that we have moral duties to oneself and to others. An individual exhibiting solidarity, comradery and altruism during a disaster is indeed behaving as a reasonable Self, and exercising ethical individualism as per Gewirthian philosophy. It is the duty of the State and society to act as a supportive State and a caring society. In order to do this, we need to be conditioned for ethical rationality before any whiff of disaster arises, i.e. in our day-to-day conduct and decision-making, at a personal, institutional and transnational level. Our ethical resilience during disasters can only be as robust as our rational moral compass during ‘peace-time’. This chapter argues that Gewirthian solidarity ethics (GSE) should play a role in European policy and action in order to provide a system that conditions ethical rationality and in order to fulfil human rights. This involves addressing our current understanding of human rights as distinct categories of civil, political, economic, social and cultural rights and to effect a shift towards a more holistic understanding of human rights, whereby the hierarchy of fulfilment does not always prioritise civil and political rights.Peer reviewe
Análise institucional de práticas psicológicas extensionistas em Unidades Básicas de Saúde
Este relato apresenta a experiência de uma prática extensionista, com ênfase em saúde, desenvolvida por um curso de Psicologia de uma universidade pública em um município da região metropolitana de Londrina (PR). Partiu-se da análise institucional, envolvendo observação, identificação de demanda e intervenção. Desenvolveram-se ações extensionistas exitosas com usuários da Atenção Básica e profissionais das equipes de saúde de Unidades Básicas de Saúde. http://dx.doi.org/10.35700/ca.2020.ano7n13.p59-63.284
Characterization of proton irradiated 3D-DDTC pixel sensor prototypes fabricated at FBK
In this paper we discuss results relevant to 3D Double-Side Double Type
Column (3D-DDTC) pixel sensors fabricated at FBK (Trento, Italy) and oriented
to the ATLAS upgrade. Some assemblies of these sensors featuring different
columnar electrode configurations (2, 3, or 4 columns per pixel) and coupled to
the ATLAS FEI3 read-out chip were irradiated up to large proton fluences and
tested in laboratory with radioactive sources. In spite of the non optimized
columnar electrode overlap, sensors exhibit reasonably good charge collection
properties up to an irradiation fluence of 2 x 10**15 neq/cm2, while requiring
bias voltages in the order of 100 V. Sensor operation is further investigated
by means of TCAD simulations which can effectively explain the basic mechanisms
responsible for charge loss after irradiation.Comment: Preprint submitted to Nuclear Instruments and Methods A, 11 pages, 13
fig
Epstein-Barr virus transcription factor Zta acts through distal regulatory elements to directly control cellular gene expression
Lytic replication of the human gamma herpes virus Epstein-Barr virus (EBV) is an essential prerequisite for the spread of the virus. Differential regulation of a limited number of cellular genes has been reported in B-cells during the viral lytic replication cycle. We asked whether a viral bZIP transcription factor, Zta (BZLF1, ZEBRA, EB1), drives some of these changes. Using genome-wide chromatin immunoprecipitation coupled to next-generation DNA sequencing (ChIP-seq) we established a map of Zta interactions across the human genome. Using sensitive transcriptome analyses we identified 2263 cellular genes whose expression is significantly changed during the EBV lytic replication cycle. Zta binds 278 of the regulated genes and the distribution of binding sites shows that Zta binds mostly to sites that are distal to transcription start sites. This differs from the prevailing view that Zta activates viral genes by binding exclusively at promoter elements. We show that a synthetic Zta binding element confers Zta regulation at a distance and that distal Zta binding sites from cellular genes can confer Zta-mediated regulation on a heterologous promoter. This leads us to propose that Zta directly reprograms the expression of cellular genes through distal elements
Keratoconus associated with choroidal neovascularization: a case report
<p>Abstract</p> <p>Introduction</p> <p>Keratoconus and choroidal neovascularization can occur as a result of dysfunction of the epithelium and its basement membrane.</p> <p>Case presentation</p> <p>A 17-year-old Asian man, who was diagnosed with myopic choroidal neovascularization in both eyes and who subsequently underwent intravitreal injection of ranibizumab (Lucentis<sup>®</sup>) five times over six months, presented with further vision decrease and pain in his right eye. Examination showed corneal steepening and stromal edema in the inferocentral cornea of his right eye, both of which were indicative of advanced keratoconus with acute hydrops. Corneal topography also showed features consistent with keratoconus in his left eye. Fluorescein angiography and optical coherence tomography revealed choroidal neovascularization-associated subretinal hemorrhages and lacquer cracks in both eyes.</p> <p>Conclusion</p> <p>Keratoconus and choroidal neovascularization, possibly resulting from dysfunction of the epithelium and its basement membrane, can occur together in the same individual. This would suggest a possible connection in pathogenesis between these two conditions.</p
R&D Paths of Pixel Detectors for Vertex Tracking and Radiation Imaging
This report reviews current trends in the R&D of semiconductor pixellated
sensors for vertex tracking and radiation imaging. It identifies requirements
of future HEP experiments at colliders, needed technological breakthroughs and
highlights the relation to radiation detection and imaging applications in
other fields of science.Comment: 17 pages, 2 figures, submitted to the European Strategy Preparatory
Grou
A Revised Parallel-Sequence Morphological Classification of Galaxies: Structure and Formation of S0 and Spheroidal Galaxies
We update van den Bergh's parallel sequence galaxy classification in which S0
galaxies form a sequence S0a-S0b-S0c that parallels the sequence Sa-Sb-Sc of
spiral galaxies. The ratio B/T of bulge to total light defines the position of
a galaxy in each sequence. Our classification makes one improvement. We extend
the S0a-S0b-S0c sequence to spheroidal ("Sph'") galaxies that are positioned in
parallel to irregular galaxies in a similarly extended Sa-Sb-Sc-Im sequence.
This provides a natural "home" for spheroidals, which previously were omitted
from galaxy classifications. To motivate our juxtaposition of Sph and irregular
galaxies, we present photometry and bulge-disk decompositions of Virgo S0s,
including late-type S0s that bridge the gap between S0b and Sph galaxies. NGC
4762 is a SB0bc with B/T = 0.13. NGC 4452 is a SB0c galaxy with an even tinier
pseudobulge. VCC 2048 and NGC 4638 have properties of both S0cs and Sphs. We
update the structural parameter correlations Sphs, irregulars, bulges, and
disks. We show that spheroidals of increasing luminosity form a continuous
sequence with the disks (but not bulges) of S0c-S0b-S0a galaxies. Remarkably,
the Sph--S0-disk sequence is almost identical to that of irregular galaxies and
spiral galaxy disks. We review published observations for galaxy transformation
processes, particularly ram-pressure stripping of cold gas. We suggest that Sph
galaxies are transformed, "red and dead" Scd--Im galaxies in the same way that
many S0 galaxies are transformed, red and dead Sa-Sc spiral galaxiesComment: 43 pages, 40 postscript figures, 1 table; TeX, requires eplain.tex;
accepted for publication in ApJS; for a version with full-resolution figures,
see http://chandra.as.utexas.edu/~kormendy/parallel.pd
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