208 research outputs found
Defense Drafts Aluminium
S. J. Swensson, secretary, Aluminium Wares Association, tells of the industry and defens
Trends in International Maths and Science Study (TIMSS) 2019 National Report for England
The Trends in International Mathematics and Science Study (TIMSS) is a survey of the educational achievement of pupils in years 5 and 9 organised by the International Association for the Evaluation of Educational Achievement (IEA).
The report provides analysis of the TIMSS 2019 findings for England and compares England’s performance to performance in other participating countries
Oscillator Strengths and Damping Constants for Atomic Lines in the J and H Bands
We have built a line list in the near-infrared J and H bands (1.00-1.34,
1.49-1.80 um) by gathering a series of laboratory and computed line lists.
Oscillator strengths and damping constants were computed or obtained by fitting
the solar spectrum.
The line list presented in this paper is, to our knowledge, the most complete
one now available, and supersedes previous lists.Comment: Accepted, Astrophysical Journal Supplement, tentatively scheduled for
the Sep. 1999 Vol. 124 #1 issue. Text and tables also available at
http://www.iagusp.usp.br/~jorge
Rhomboid family member 2 regulates cytoskeletal stress-associated Keratin 16.
Keratin 16 (K16) is a cytoskeletal scaffolding protein highly expressed at pressure-bearing sites of the mammalian footpad. It can be induced in hyperproliferative states such as wound healing, inflammation and cancer. Here we show that the inactive rhomboid protease RHBDF2 (iRHOM2) regulates thickening of the footpad epidermis through its interaction with K16. K16 expression is absent in the thinned footpads of irhom2-/- mice compared with irhom2+/+mice, due to reduced keratinocyte proliferation. Gain-of-function mutations in iRHOM2 underlie Tylosis with oesophageal cancer (TOC), characterized by palmoplantar thickening, upregulate K16 with robust downregulation of its type II keratin binding partner, K6. By orchestrating the remodelling and turnover of K16, and uncoupling it from K6, iRHOM2 regulates the epithelial response to physical stress. These findings contribute to our understanding of the molecular mechanisms underlying hyperproliferation of the palmoplantar epidermis in both physiological and disease states, and how this 'stress' keratin is regulated
Modelling the light variability of the Ap star epsilon Ursae Majoris
We simulate the light variability of the Ap star epsUMa using the observed
surface distributions of Fe, Cr, Ca, Mn, Mg, Sr and Ti obtained with the help
of Doppler Imaging technique. Using all photometric data available we specified
light variations of epsUMa modulated by its rotation from far UV to IR. We
employed the LLmodels stellar model atmosphere code to predict the light
variability in different photometric systems. The rotational period of epsUMa
is refined to 5d088631(18). It is shown that the observed light variability can
be explained as a result of the redistribution of radiative flux from the UV
spectral region to the visual caused by the inhomogeneous surface distribution
of chemical elements. Among seven mapped elements, only Fe and Cr significantly
contribute to the amplitude of the observed light variability. In general, we
find a very good agreement between theory and observations. We confirm the
important role of Fe and Cr to the magnitude of the well-known depression
around 5200 \AA\ through the analysis of the peculiar -parameter. Finally,
we show that the abundance spots of considered elements cannot explain the
observed variability in near UV and index which are likely due to some
other causes. The inhomogeneous surface distribution of chemical elements can
explain most of the observed light variability of the A-type CP star epsUMa.Comment: Accepted in A&A, 10 pages, 9 figures, 3 table
Carbon Stars in the Hamburg/ESO Survey: Abundances
We have carried out a detailed abundance analysis for a sample of 16 carbon
stars found among candidate extremely metal-poor (EMP) stars from the
Hamburg/ESO Survey. We find that the Fe-metallicities for the cooler C-stars
(Teff ~ 5100K) have been underestimated by a factor of ~10 by the standard HES
survey tools. The results presented here provided crucial supporting data used
by Cohen et al (2006) to derive the frequency of C-stars among EMP stars.
C-enhancement in these EMP C-stars appears to be independent of
Fe-metallicity and approximately constant at ~1/5 the solar C/H. The mostly low
C12/C13 ratios (~4) and the high N abundances in many of these stars suggest
that material which has been through proton burning via the CN cycle comprises
most of the stellar envelope. C-enhancement is associated with strong
enrichment of heavy nuclei beyond the Fe-peak for 12 of the 16 stars. The
remaining C-stars from the HES, which tend to be the most Fe-metal poor, show
no evidence for enhancement of the heavy elements. Very high enhancements of
lead are detected in some of the C-stars with highly enhanced Ba. (We show
that) the s-process is responsible for the enhancement of the heavy elements
for the majority of the C-stars in our sample.
We suggest that both the s-process rich and Ba-normal C-stars result from
phenomena associated with mass transfer in binary systems. This leads directly
to the progression from C-stars to CH stars and then to Ba stars as the
Fe-metallicity increases. (abridged and slightly edited to shorten)Comment: AJ, in press, submitted 13 Dec, 2005, accepted 21 March 200
Decision theory applied to image quality control in radiology
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Evaluation of two dairy herd reproductive performance indicators that are adjusted for voluntary waiting period
<p>Abstract</p> <p>Background</p> <p>Overall reproductive performance of dairy herds is monitored by various indicators. Most of them do not consider all eligible animals and do not consider different management strategies at farm level. This problem can be alleviated by measuring the proportion of pregnant cows by specific intervals after their calving date or after a fixed time period, such as the voluntary waiting period. The aim of this study was to evaluate two reproductive performance indicators that consider the voluntary waiting period at the herd. The two indicators were: percentage of pregnant cows in the herd after the voluntary waiting period plus 30 days (PV30) and percentage of inseminated cows in the herd after the voluntary waiting period plus 30 days (IV30). We wanted to assess how PV30 and IV30 perform in a simulation of herds with different reproductive management and physiology and to compare them to indicators of reproductive performance that do not consider the herd voluntary waiting period.</p> <p>Methods</p> <p>To evaluate the reproductive indicators we used the SimHerd-program, a stochastic simulation model, and 18 scenarios were simulated. The scenarios were designed by altering the reproductive management efficiency and the status of reproductive physiology of the herd. Logistic regression models, together with receiver operating characteristics (ROC), were used to examine how well the reproductive performance indicators could discriminate between herds of different levels of reproductive management efficiency or reproductive physiology.</p> <p>Results</p> <p>The logistic regression models with the ROC analysis showed that IV30 was the indicator that best discriminated between different levels of management efficiency followed by PV30, calving interval, 200-days not-in calf-rate (NotIC200), in calf rate at100-days (IC100) and a fertility index. For reproductive physiology the ROC analysis showed that the fertility index was the indicator that best discriminated between different levels, followed by PV30, NotIC200, IC100 and the calving interval. IV30 could not discriminate between the two levels.</p> <p>Conclusion</p> <p>PV30 is the single best performance indicator for estimating the level of both herd management efficiency and reproductive physiology followed by NotIC200 and IC100. This indicates that PV30 could be a potential candidate for inclusion in dairy herd improvement schemes.</p
On the Internal Structure of Relativistic Jets
A magnetohydrodynamic model is constructed for a cylindrical jet immersed in
an external uniform magnetic field. It is shown that, as in the force-free
case, the total electric current within the jet can be zero. The particle
energetics and the magnetic field structure are determined in a self-consistent
way; all jet parameters depend on the physical conditions in the external
medium. In particular, we show that a region with subsonic flow can exist in
the central jet regions. In actual relativistic jets, most of the energy is
transferred by the electromagnetic field only when the magnetization parameter
is sufficiently large, . We also show that, in general, the
well-known solution with a central core, ,
can not be realized in the presence of an external medium.Comment: 19 pages, 2 figure
- …