310 research outputs found
The EOS CERES Global Cloud Mask
To detect long-term climate trends, it is essential to produce long-term and consistent data sets from a variety of different satellite platforms. With current global cloud climatology data sets, such as the International Satellite Cloud Climatology Experiment (ISCCP) or CLAVR (Clouds from Advanced Very High Resolution Radiometer), one of the first processing steps is to determine whether an imager pixel is obstructed between the satellite and the surface, i.e., determine a cloud 'mask.' A cloud mask is essential to studies monitoring changes over ocean, land, or snow-covered surfaces. As part of the Earth Observing System (EOS) program, a series of platforms will be flown beginning in 1997 with the Tropical Rainfall Measurement Mission (TRMM) and subsequently the EOS-AM and EOS-PM platforms in following years. The cloud imager on TRMM is the Visible/Infrared Sensor (VIRS), while the Moderate Resolution Imaging Spectroradiometer (MODIS) is the imager on the EOS platforms. To be useful for long term studies, a cloud masking algorithm should produce consistent results between existing (AVHRR) data, and future VIRS and MODIS data. The present work outlines both existing and proposed approaches to detecting cloud using multispectral narrowband radiance data. Clouds generally are characterized by higher albedos and lower temperatures than the underlying surface. However, there are numerous conditions when this characterization is inappropriate, most notably over snow and ice of the cloud types, cirrus, stratocumulus and cumulus are the most difficult to detect. Other problems arise when analyzing data from sun-glint areas over oceans or lakes over deserts or over regions containing numerous fires and smoke. The cloud mask effort builds upon operational experience of several groups that will now be discussed
Technical design and commissioning of the KATRIN large-volume air coil system
The KATRIN experiment is a next-generation direct neutrino mass experiment
with a sensitivity of 0.2 eV (90% C.L.) to the effective mass of the electron
neutrino. It measures the tritium -decay spectrum close to its endpoint
with a spectrometer based on the MAC-E filter technique. The -decay
electrons are guided by a magnetic field that operates in the mT range in the
central spectrometer volume; it is fine-tuned by a large-volume air coil system
surrounding the spectrometer vessel. The purpose of the system is to provide
optimal transmission properties for signal electrons and to achieve efficient
magnetic shielding against background. In this paper we describe the technical
design of the air coil system, including its mechanical and electrical
properties. We outline the importance of its versatile operation modes in
background investigation and suppression techniques. We compare magnetic field
measurements in the inner spectrometer volume during system commissioning with
corresponding simulations, which allows to verify the system's functionality in
fine-tuning the magnetic field configuration. This is of major importance for a
successful neutrino mass measurement at KATRIN.Comment: 32 pages, 16 figure
Subtractive isolation of phage-displayed single-chain antibodies to thymic stromal cells by using intact thymic fragments
In the murine thymus, the stroma forms microenvironments that control different steps in T cell development. To study the architecture of such microenvironments and more particularly the nature of communicative signals in lympho–stromal interaction during T cell development, we have employed the phage antibody display technology, with the specific aim of isolating thymic stromal cellspecific single-chain antibodies from a semisynthetic phage library. A subtractive approach using intact, mildly fixed thymic fragments as target tissue and lymphocytes as absorber cells generated monoclonal phages (MoPhabs) detecting subsets of murine thymic stromal cells.
In the present paper we report on the reactivity of single-chain antibodies derived from three MoPhabs, TB4–4, TB4–20, and TB4–28. While TB4–4 and TB4–20 are both epithelium specific, TB4–28 detects an epitope expressed on both epithelial- and mesenchymal-derived stromal cells. TB4–4 reacts with all cortical epithelial cells and with other endoderm-derived epithelia, but this reagent leaves the majority of medullary epithelial cells unstained. In contrast, MoPhab TB4–20 detects both cortical and medullary thymic epithelial cells, as well as other endoderm- and ectoderm-derived epithelial cells. Cross-reaction of single-chain antibodies to human thymic stromal cells shows that our semisynthetic phage antibody display library, in combination with the present subtractive approach, permits detection of evolutionary conserved epitopes expressed on subsets of thymic stromal cells
Quality of private and public ambulatory health care in low and middle income countries: systematic review of comparative studies
Paul Garner and colleagues conducted a systematic review of 80 studies to compare
the quality of private versus public ambulatory health care in low- and
middle-income countries
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Challenges in QCD matter physics --The scientific programme of the Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sNN= 2.7--4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (μB> 500 MeV), effects of chiral symmetry, and the equation of state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2024, in the context of the worldwide efforts to explore high-density QCD matter
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to
explore the phase diagram of strongly interacting matter. At LHC and top RHIC
energies, QCD matter is studied at very high temperatures and nearly vanishing
net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was
created at experiments at RHIC and LHC. The transition from the QGP back to the
hadron gas is found to be a smooth cross over. For larger net-baryon densities
and lower temperatures, it is expected that the QCD phase diagram exhibits a
rich structure, such as a first-order phase transition between hadronic and
partonic matter which terminates in a critical point, or exotic phases like
quarkyonic matter. The discovery of these landmarks would be a breakthrough in
our understanding of the strong interaction and is therefore in the focus of
various high-energy heavy-ion research programs. The Compressed Baryonic Matter
(CBM) experiment at FAIR will play a unique role in the exploration of the QCD
phase diagram in the region of high net-baryon densities, because it is
designed to run at unprecedented interaction rates. High-rate operation is the
key prerequisite for high-precision measurements of multi-differential
observables and of rare diagnostic probes which are sensitive to the dense
phase of the nuclear fireball. The goal of the CBM experiment at SIS100
(sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD
matter: the phase structure at large baryon-chemical potentials (mu_B > 500
MeV), effects of chiral symmetry, and the equation-of-state at high density as
it is expected to occur in the core of neutron stars. In this article, we
review the motivation for and the physics programme of CBM, including
activities before the start of data taking in 2022, in the context of the
worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
Relationship between B-type natriuretic peptide levels and echocardiographic indices of left ventricular filling pressures in post-cardiac surgery patients
<p>Abstract</p> <p>Background</p> <p>B-type natriuretic peptide (BNP) is increased in post-cardiac surgery patients, however the mechanisms underlying BNP release are still unclear. In the current study, we aimed to assess the relationship between postoperative BNP levels and left ventricular filling pressures in post-cardiac surgery patients.</p> <p>Methods</p> <p>We prospectively enrolled 134 consecutive patients referred to our Center 8 ± 5 days after cardiac surgery. BNP was sampled at hospital admission and related to the following echocardiographic parameters: left ventricular (LV) diastolic volume (DV), LV systolic volume (SV), LV ejection fraction (EF), LV mass, relative wall thickness (RWT), indexed left atrial volume (<sub>i</sub>LAV), mitral inflow E/A ratio, mitral E wave deceleration time (DT), ratio of the transmitral E wave to the Doppler tissue early mitral annulus velocity (E/E').</p> <p>Results</p> <p>A total of 124 patients had both BNP and echocardiographic data. The BNP values were significantly elevated (mean 353 ± 356 pg/ml), with normal value in only 17 patients (13.7%). Mean LVEF was 59 ± 10% (LVEF ≥50% in 108 pts). There was no relationship between BNP and LVEF (p = 0.11), LVDV (p = 0.88), LVSV (p = 0.50), E/A (p = 0.77), DT (p = 0.33) or RWT (p = 0.50). In contrast, BNP was directly related to E/E' (p < 0.001), LV mass (p = 0.006) and <sub>i</sub>LAV (p = 0.026). At multivariable regression analysis, age and E/E' were the only independent predictors of BNP levels.</p> <p>Conclusion</p> <p>In post-cardiac surgery patients with overall preserved LV systolic function, the significant increase in BNP levels is related to E/E', an echocardiographic parameter of elevated LV filling pressures which indicates left atrial pressure as a major determinant in BNP release in this clinical setting.</p
A cross sectional comparison of postnatal care quality in facilities participating in a maternal health voucher program versus non-voucher facilities in Kenya
Background: Health service fees constitute substantial barriers for women seeking childbirth and postnatal care. In an effort to reduce health inequities, the government of Kenya in 2006 introduced the output-based approach (OBA), or voucher programme, to increase poor women’s access to quality Safe Motherhood services including postnatal care. To help improve service quality, OBA programmes purchase services on behalf of the poor and marginalised, with provider reimbursements for verified services. Kenya’s programme accredited health facilities in three districts as well as in two informal Nairobi settlements.
Methods: Postnatal care quality in voucher health facilities (n = 21) accredited in 2006 and in similar non-voucher health facilities (n = 20) are compared with cross sectional data collected in 2010. Summary scores for quality were calculated as additive sums of specific aspects of each attribute (structure, process, outcome). Measures of effect were assessed in a linear regression model accounting for clustering at facility level. Data were analysed using Stata 11.0.
Results: The overall quality of postnatal care is poor in voucher and non-voucher facilities, but many facilities demonstrated ‘readiness’ for postnatal care (structural attributes: infrastructure, equipment, supplies, staffing, training) indicated by high scores (83/111), with public voucher facilities scoring higher than public non-voucher facilities. The two groups of facilities evinced no significant differences in postnatal care mean process scores: 14.2/ 55 in voucher facilities versus 16.4/55 in non-voucher facilities; coefficient: -1.70 (-4.9, 1.5), p = 0.294. Significantly more newborns were seen within 48 hours (83.5 % versus 72.1 %: p = 0.001) and received Bacillus Calmette-Guerin (BCG) (82.5 % versus 76.5 %: p \u3c 0.001) at voucher facilities than at non-voucher facilities.
Conclusions: Four years after facility accreditation in Kenya, scores for postnatal care quality are low in all facilities, even those with Safe Motherhood vouchers. We recommend the Kenya OBA programme review its Safe Motherhood reimbursement package and draw lessons from supply side results-based financing initiatives, to improve postnatal care quality
Long head BIceps TEnodesis or tenotomy in arthroscopic rotator cuff repair: BITE study protocol
Bilateral strio-pallido-dentate calcinosis (Fahr’s disease): report of seven cases and revision of literature
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