19,811 research outputs found
The Comparison of the Swift Gamma-Ray Bursts With and Without Measured Redshifts
Gamma-ray bursts, detected by the Swift satellite, are separated into two
samples: the bursts with and without determined redshifts. These two samples
are compared by the standard Student t-test and F-test. We have compared the
dispersions and the mean values of the durations, peak fluxes and fluences in
order to find any differences among these two samples. No essential differences
were found.Comment: Published in the Proceedings of the 4th Heidelberg International
Symposium on High Energy Gamma-Ray Astronomy, 200
Nitrogen abundances in giant stars of the globular cluster NGC 6752
We present N abundances for 21 bright giants in the globular cluster NGC 6752
based on high-resolution UVES spectra of the 3360A NH lines. We confirm that
the Stromgren c1 index traces the N abundance and find that the star-to-star N
abundance variation is 1.95 dex, at the sample's luminosity. We find
statistically significant correlations, but small amplitude variations, between
the abundances of N and alpha-, Fe-peak, and s-process elements. Analyses using
model atmospheres with appropriate N, O, Na, and Al abundances would
strengthen, rather than mute, these correlations. If the small variations of
heavy elements are real, then the synthesis of the N anomalies must take place
in stars which also synthesize alpha-, Fe-peak, and s-process elements. These
correlations offer support for contributions from both AGB and massive stars to
the globular cluster abundance anomalies.Comment: Accepted for publication in Ap
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Targeting STATs for cancer therapy: “Undruggable” no more
We are in the midst of an exciting transition in the treatment of cancers, from the empirically developed non-specifically cytotoxic drugs to the era of rationally derived molecularly targeted therapies. Over the past 15 years, our understanding of the mutations that drive cancer pathogenesis has grown enormously, which has rapidly led to the development of drugs to target the associated gene products. Almost all of this focus has been on kinases, largely tyrosine kinases that are activated by translocations, point mutations, insertions and deletions. Although this approach will continue to bear fruit for some time, there is increasing evidence that the returns will be diminishing. First, dominant activating mutations in kinases are less frequent then initially expected particularly in common human cancers, and thus the number of patient whose tumors have suitable targets may be limited. The second cause for concern is the rapid development of resistance that often occurs, arising either from mutations in the target kinase or activation of a parallel pathway. Thus, the desire to target a common convergence point of multiple pathways that directly contributes to the oncogenic phenotype is highly desirable. This goal has led to consideration of transcription factors as therapeutic targets
William H. Sorrell, Attorney General of Vermont, et al. v. IMS Health Inc., et al. - Amicus Brief in Support of Petitioners
On April 26, 2011, the US Supreme Court will hear oral arguments in the Vermont data mining case, Sorrell v. IMS Health Inc. Respondents claim this is the most important commercial speech case in a decade. Petitioner (the State of Vermont) argues this is the most important medical privacy case since Whalen v. Roe.
The is an amicus brief supporting Vermont, written by law professors and submitted on behalf of the New England Journal of Medicin
Effect of genotype on duodenal expression of nutrient transporter genes in dairy cows
peer-reviewedBackground
Studies have shown clear differences between dairy breeds in their feed intake and production efficiencies. The duodenum is critical in the coordination of digestion and absorption of nutrients. This study examined gene transcript abundance of important classes of nutrient transporters in the duodenum of non lactating dairy cows of different feed efficiency potential, namely Holstein-Friesian (HF), Jersey (JE) and their F1 hybrid. Duodenal epithelial tissue was collected at slaughter and stored at -80°C. Total RNA was extracted from tissue and reverse transcribed to generate cDNA. Gene expression of the following transporters, namely nucleoside; amino acid; sugar; mineral; and lipid transporters was measured using quantitative real-time RT-PCR. Data were statistically analysed using mixed models ANOVA in SAS. Orthogonal contrasts were used to test for potential heterotic effects and spearman correlation coefficients calculated to determine potential associations amongst gene expression values and production efficiency variables.
Results
While there were no direct effects of genotype on expression values for any of the genes examined, there was evidence for a heterotic effect (P < 0.05) on ABCG8, in the form of increased expression in the F1 genotype compared to either of the two parent breeds. Additionally, a tendency for increased expression of the amino acid transporters, SLC3A1 (P = 0.072), SLC3A2 (P = 0.081) and SLC6A14 (P = 0.072) was also evident in the F1 genotype. A negative (P < 0.05) association was identified between the expression of the glucose transporter gene SLC5A1 and total lactational milk solids yield, corrected for body weight. Positive correlations (P < 0.05) were also observed between the expression values of genes involved in common transporter roles.
Conclusion
This study suggests that differences in the expression of sterol and amino acid transporters in the duodenum could contribute towards the documented differences in feed efficiency between HF, JE and their F1 hybrid. Furthermore, positive associations between the expression of genes involved in common transporter roles suggest that these may be co-regulated. The study identifies potential candidates for investigation of genetic variants regulating nutrient transport and absorption in the duodenum in dairy cows, which may be incorporated into future breeding programmes
Raiders of the Lost Architecture: Kernels for Bayesian Optimization in Conditional Parameter Spaces
In practical Bayesian optimization, we must often search over structures with
differing numbers of parameters. For instance, we may wish to search over
neural network architectures with an unknown number of layers. To relate
performance data gathered for different architectures, we define a new kernel
for conditional parameter spaces that explicitly includes information about
which parameters are relevant in a given structure. We show that this kernel
improves model quality and Bayesian optimization results over several simpler
baseline kernels.Comment: 6 pages, 3 figures. Appeared in the NIPS 2013 workshop on Bayesian
optimizatio
On the Intermediate Subgroup of the Gamma-Ray Bursts in the Swift Database
A sample of 286 gamma-ray bursts, detected by Swift satellite, is studied
statistically by the chi^2 test and the Student t-test, respectively. The short
and long subgroups are well detected in the Swift data. But no intermediate
subgroup is seen. The non-detection of this subgroup in the Swift database can
be explained, once it is assumed that in the BATSE database the short and the
intermediate subgroups form a common subclass.Comment: Published in 4th Heidelberg International Symposium on High Energy
Gamma-Ray Astronomy, 200
Adding value to cull cow beef
End of project reportThis project addressed the prospects of increasing the value of cull cow beef and examined the potential of a number of different management and dietary strategies. In Ireland, the national cow herd contributes 350,000 animals to total beef production annually, which represents 22% of all cattle slaughtered (DAF, 2007). A dominant feature of beef production in Ireland is the disposal of cows from the dairy and beef industries, the time of year at which culling occurs influences the number of cows available for slaughter. Suitability of a cow for slaughter is generally not a consideration for dairy or beef farmers
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