1,023 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
Scientific, Technical and Economic Committee for Fisheries. Review of scientific advice for 2012 - Part 2 (STECF-11-09) - Corrigendum
This corrigendum should replace the corresponding sections in the Part 2 of the STECF Review of advice for 2012 (STECF 2011. Review of scientific advice for 2012 – Part 2. Publications Office of the European Union, Luxembourg, EUR 24897 EN, JRC66020)
Timing jitter in photon detection by straight superconducting nanowires: Effect of magnetic field and photon flux
We studied the effect of the external magnetic field and photon flux on
timing jitter in photon detection by straight superconducting NbN nanowires. At
two wavelengths 800 and 1560 nm, statistical distribution in the appearance
time of the photon count exhibits Gaussian shape at small times and exponential
tail at large times. The characteristic exponential time is larger for photons
with smaller energy and increases with external magnetic field while variations
in the Gaussian part of the distribution are less pronounced. Increasing photon
flux drives the nanowire from quantum detection mode to the bolometric mode
that averages out fluctuations of the total number of nonequilibrium electrons
created by the photon and drastically reduces jitter. The difference between
Gaussian parts of distributions for these two modes provides the measure for
the electron-number fluctuations. Corresponding standard deviation increases
with the photon energy. We show that the two-dimensional hot-spot detection
model explains qualitatively the effect of magnetic field
Recommended from our members
Effect of in-servicing teachers on student achievement in integrated pest management
The primary purpose of this study was to determine if inservicing Agriculture Science and Technology (AST) teachers over a new curriculum, resulted in increased student achievement. Specific objectives were to: 1) determine the subject areas (lessons) for a curriculum for teaching Integrated Pest Management (IPM); 2) develop a curriculum for an introductory course on IPM from the determined subject areas; and 3) compare student's achievement scores to determine the effect of inservicing teachers on student achievement. The research instrument used in this study was an Integrated Pest Management curriculum developed by the researcher based on objectives determined from the literature, texts, and other sources of technical information pertaining to IPM. The curriculum was validated by a panel of experts In the fields of IPM and secondary education. The population for this study consisted of 20 Oregon AST teachers who were identified by a panel of five experts as the innovators and early adopters among their peers. These innovators and early adopters represented a distinct population of individuals within the general population of AST teachers in Oregon. The students of the 20 teachers provided the sample data for the study. The 20 teachers in the study were randomly divided into two groups. The experimental group received one hour inservice instruction over the IPM curriculum at their schools, and consultation via telephone during the 3 to 4 week period when the curriculum was taught to their students. The teachers in the control group only received the IPM curriculum in the mail. They were not inserviced, and they did not receive consultation via telephone regarding use of the curriculum. The students in both groups were examined over the material with an exam developed by the researcher and the student's mean test scores from the two groups were compared. The null hypothesis that no difference existed between the student's mean test scores was rejected at alpha = 0.01. The results indicated a highly significant difference between the student's mean test scores. The alternate hypothesis that the student's mean test score was higher in the teacher experimental group (those who were inserviced) than the teacher control group (those not inserviced) was retained. The conclusion drawn from this research is that jnservicing Oregon Agriculture Science and Technology teachers over new curricula increases student achievement
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
Recommended from our members
Argonne National Laboratory Reports
The report summarizes and evaluates experiments conducted in the Transient Reactor Test Facility (TREAT) using the Mark-II loop facility. The tests discussed are of the E and H series. Detailed descriptions of test conditions and test results as of February 1974 are presented. Since all data have not been acquired on all experiments, this report must be considered interim in nature. Particular emphasis is placed on data relevant to Fast Test Reactor (FTR) safety-analysis efforts
- …