1,237 research outputs found
Allelic variation in HLA-B and HLA-C sequences and the evolution of the HLA-B alleles
Several new HLA-B (B8, B51, Bw62)- and
HLA-C (Cw6, Cw7)-specific genes were isolated either as
genomic cosmid or cDNA clones to study the diversity
of HLA antigens. The allele specificities were identified
by sequence analysis in comparison with published HLAB
and -C sequences, by transfection experiments, and
Southern and northern blot analysis using oligonucleotide
probes. Comparison of the classical HLA-A, -B, and -C
sequences reveals that allele-specific substitutions seem
to be rare events. HLA-B51 codes only for one allelespecific
residue: arginine at position 81 located on the cd
helix, pointing toward the antigen binding site. HLA-B8
contains an acidic substitution in amino acid position 9
on the first central/3 sheet which might affect antigen binding
capacity, perhaps in combination with the rare
replacement at position 67 (F) on the Alpha-l helix. HLA-B8
shows greatest homology to HLA-Bw42, -Bw41, -B7, and
-Bw60 antigens, all of which lack the conserved restriction
sites Pst I at position 180 and Sac I at position 131.
Both sites associated with amino acid replacements seem
to be genetic markers of an evolutionary split of the HLA-B
alleles, which is also observed in the leader sequences.
HLA-Cw7 shows 98% sequence identity to the JY328
gene. In general, the HLA-C alleles display lower levels
of variability in the highly polymorphic regions of the Alpha 1
and Alpha 2 domains, and have more distinct patterns of locusspecific
residues in the transmembrane and cytoplasmic
domains. Thus we propose a more recent origin for the
HLA-C locus
Carbohydrate utilization in obese subjects after an oral load of 100 g naturally-labelled [13C] glucose
1. Total carbohydrate (CHO) and ingested glucose oxidation was measured in five obese subjects with normal glucose tolerance after an oral load of 100g naturally-labelled [13C]glucose using indirect calorimetry and mass spectrometry respectively. 2. CHO utilization rate (107 ± 14 mg/min in the post-absorptive state) increased 30 min after the glucose load to reach a plateau (245±25 mg/min) between 90 and 120 min. It then decreased to basal values at 330 min. Cumulative CHO oxidation over 480 min was 66±7 g and the CHO oxidized above basal levels was 26 ± 7g. 3. Enrichment of expired carbon dioxide with 13c began at 45 min and maximum values were observed between 210 and 300 min. At 480 min, cumulative oxidation of the ingested glucose was 24± 2 g. 4. Compared with controls, the obese subjects exhibit an impairment of CHO utilization which precedes glucose intolerance. This impairment can be explained by an increased availability of free fatty acids which favours lipid oxidation at the expense of ingested [13C]glucose oxidatio
An evaluation of the impact of 'Lifeskills' training on road safety, substance use and hospital attendance in adolescence
AbstractPurposeTo evaluate if attendance at Lifeskills, a safety education centre for children in Year 6 (10–11 years), is associated with engagement in safer behaviours, and with fewer accidents and injuries, in adolescence.MethodsThe sample are participants in the Avon Longitudinal Study of Parents and Children who attended school in the Lifeskills catchment area in Year 6; 60% attended Lifeskills. At 14–15 years, participants (n approximately 3000, varies by outcome) self-reported road safety behaviours and accidents, and perceived health effects and use of alcohol, cannabis, and tobacco. Additional outcomes from linkage to Hospital Episodes Statistics were available for a sub-sample (n=1768): hospital admittance (for accident-related reason, from 11–16 years) and A&E attendance (for any reason, from approximately 14–16 years).ResultsChildren who attended Lifeskills were more likely to report using pedestrian crossings on their way to school than children who did not attend (59% versus 52%). Lifeskills attendance was unrelated to the ownership of cycle helmets, or the use of cycle helmets, seat belts, or reflective/fluorescent clothing, or to A&E attendance. Use of cycle helmets (37%) and reflective/fluorescent clothing (<4%) on last cycle was low irrespective of Lifeskills attendance. Lifeskills attendance was associated with less reported smoking and cannabis use, but was generally unrelated to perceptions of the health impact of substance use.ConclusionsLifeskills attendance was associated with some safer behaviours in adolescence. The overall low use of cycle helmets and reflective/fluorescent clothing evidences the need for powerful promotion of some safer behaviours at Lifeskills and at follow-up in schools
Rhizobox-Based Study of Chickpea (Cicer arietinum L.) Root System Architecture: Standard Operating Procedure (SOP) for Phenotyping and Screening to Complement Pre-Breeding
As a reflection of its importance in many plant
functions including nutrient and water uptake,
anchoring and mechanical support, as an interface
between the plant and soil, root system architecture
study has become a topic on its own in many research
areas. Therefore, current research undertakings are
geared towards unraveling the development and
architecture of root systems with the premises that it
holds important information towards its exploitation
in any research program, which aims to increase plant
performance and economic yield. Nevertheless, there
is a well-established fact that Root System
Architecture (RSA) varies among different plant
species, and the variation is well implicated, even
within the same species, which is governed by the
plant genotype and environment. Furthermore, the
inherent difficulty of studying the root system
(because of soil opacity) makes them recognized as
being ‘the hidden half’ (Waisel et al., 2005), and
because of the aforementioned factors, and/or
probably some other unforeseen reasons, RSA has
traditionally been neglected by researchers (for
example plant breeders) in terms of integrating it as
an important selection criterion in crop improvement
program
Comparison of carbohydrate utilization in man using indirect calorimetry and mass spectrometry after an oral load of 100 g naturally-labelled [13C]glucose
1. Carbohydrate (CHO) oxidation was measured simultaneously in a group of five normal subjects after an oral load of 100 g naturally-labelled [13C]glucose, using indirect calorimetry and mass spectrometry. 2. CHO utilization, calculated from the results of indirect calorimetry, increased 30 min after the glucose load to reach a peak at 90 min. It then decreased to reach basal values at 380 min. Cumulative total CHO oxidation at 480 min was 83±8g, and CHO oxidized above basal levels, 37±3 g. 3. Enrichment of expired carbon dioxide with 13C began at 60 min and maximum values were observed at 270 min. At 480 min, cumulative CHO oxidation measured by use of [13C]glucose was 29 g. The difference from calorimetric values can be attributed in part to the slow isotopic dilution in the glucose and bicarbonate pools. 4. Thus, approximately 30% of the glucose load was oxidized during the 8 h after its ingestion and this accounts for a significant part of the increased CHO oxidation (37 g), as measured by indirect calorimetr
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Argonne National Laboratory Reports
Test data from an in-pile failure experiment of high-power LMFBR-type fuel pins in a simulated $3/s transient-overpower (TOP) accident are reported and analyzed. Major conclusions are that (1) a series of cladding ruptures during the 100-ms period preceding fuel release injected small bursts of fission gas into the flow stream; (2) gas release influenced subsequent cladding melting and fuel release (there were no measurable FCI's (fuel-coolant interactions), and all fuel motion observed by the hodoscope was very slow); (3) the predominant post-failure fuel motion appears to be radial swelling that left a spongy fuel crust on the holder wall; (4) less than 4 to 6 percent of the fuel moved axially out of the original fuel zone, and most of this froze within a 10-cm region above the original top of the fuel zone to form the outlet blockage. An inlet blockage approximately 1 cm long was formed and consisted of large interconnected void regions. Both blockages began just beyond the ends of the fuel pellets
Study of temporal pulse shape effects on W using simulations and laser heating
Transient heat pulses with triangular, square, and ELM-like temporal shapes are investigated in order to further understand how transient plasma instabilities will affect plasma facing components in tokamaks. A solution to the 1D heat equation for triangular pulses allows the peak surface temperature to be written analytically for arbitrary rise times. The solution as well as ANSYS simulations reveal that a positive ramp (maximum rise time) triangular pulse has a higher peak surface temperature by a factor of sqrt{2} compared to that from a negative ramp (rise time = 0) pulse shape with equal energy density, peak power, and pulse width. Translating the results to ITER, an ELM or disruption pulse with the shortest rise time is the most benign compared to other pulse shapes with the same peak heat flux and same energy density.</p
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