2,267 research outputs found
Interaction Among \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e Pheromone Receptors During Endocytosis
This study investigates endocytosis of Saccharomyces cerevisiae α-factor receptor and the role that receptor oligomerization plays in this process. α-factor receptor contains signal sequences in the cytoplasmic C-terminal domain that are essential for ligand-mediated endocytosis. In an endocytosis complementation assay, we found that oligomeric complexes of the receptor undergo ligand-mediated endocytosis when the α-factor binding site and the endocytosis signal sequences are located in different receptors. Both in vitro and in vivo assays suggested that ligand-induced conformational changes in one Ste2 subunit do not affect neighboring subunits. Therefore, recognition of the endocytosis signal sequence and recognition of the ligand-induced conformational change are likely to be two independent events
Divergence and Shannon information in genomes
Shannon information (SI) and its special case, divergence, are defined for a
DNA sequence in terms of probabilities of chemical words in the sequence and
are computed for a set of complete genomes highly diverse in length and
composition. We find the following: SI (but not divergence) is inversely
proportional to sequence length for a random sequence but is length-independent
for genomes; the genomic SI is always greater and, for shorter words and longer
sequences, hundreds to thousands times greater than the SI in a random sequence
whose length and composition match those of the genome; genomic SIs appear to
have word-length dependent universal values. The universality is inferred to be
an evolution footprint of a universal mode for genome growth.Comment: 4 pages, 3 tables, 2 figure
An Econometric Analysis of ETF and ETF Futures in Financial and Energy Markets Using Generated Regressors
It is well known that that there is an intrinsic link between the financial and energy sectors, which can be analyzed through their spillover effects, which are measures of how the shocks to returns in different assets affect each other’s subsequent volatility in both spot and futures markets. Financial derivatives, which are not only highly representative of the underlying indices but can also be traded on both the spot and futures markets, include Exchange Traded Funds (ETFs), which is a tradable spot index whose aim is to replicate the return of an underlying benchmark index. When ETF futures are not available to examine spillover effects, “generated regressors” may be used to construct both Financial ETF futures and Energy ETF futures. The purpose of the paper is to investigate the co-volatility spillovers within and across the US energy and financial sectors in both spot and futures markets, by using “generated regressors” and a multivariate conditional volatility model, namely Diagonal BEKK. The daily data used are from 1998/12/23 to 2016/4/22. The data set is analyzed in its entirety, and also subdivided into three subset time periods. The empirical results show there is a significant relationship between the Financial ETF and Energy ETF in the spot and futures markets. Therefore, financial and energy ETFs are suitable for constructing a financial portfolio from an optimal risk management perspective, and also for dynamic hedging purposes
Feynman Rules in the Type III Natural Flavour-Conserving Two-Higgs Doublet Model
We consider a two Higgs-doublet model with symmetry, which implies a
rather than 0 relative phase between the vacuum expectation
values . The corresponding Feynman rules are derived
accordingly and the transformation of the Higgs fields from the weak to the
mass eigenstates includes not only an angle rotation but also a phase
transformation. In this model, both doublets couple to the same type of
fermions and the flavour-changing neutral currents are naturally suppressed. We
also demonstrate that the Type III natural flavour-conserving model is valid at
tree-level even when an explicit symmetry breaking perturbation is
introduced to get a reasonable CKM matrix. In the special case , as the ratio runs from 0 to ,
the dominant Yukawa coupling will change from the first two generations to the
third generation. In the Feynman rules, we also find that the charged Higgs
currents are explicitly left-right asymmetric. The ratios between the left- and
right-handed currents for the quarks in the same generations are estimated.Comment: 16 pages (figures not included), NCKU-HEP/93-1
Sexually dimorphic brain volume interaction in college-aged binge drinkers.
BACKGROUND: Binge consumption of alcohol is a major societal problem associated with important cognitive, physiological and neurotoxic consequences. Converging evidence highlights the need to assess binge drinking (BD) and its effects on the developing brain while taking into account gender differences. Here, we compared the brain volumetric differences between genders in college-aged binge drinkers and healthy volunteers. METHOD: T1-weighted magnetic resonance imaging (MRI) images of 30 binge drinkers (18 males) and 46 matched healthy volunteers (23 males) were examined using voxel-based morphometry. The anatomical scans were covaried with Alcohol Use Disorders Identification Test (AUDIT) scores. Whole brain voxel-wise group comparisons were performed using a cluster extent threshold correction. RESULTS: Several large clusters qualified with group-by-gender interactions were observed in prefrontal, striatal and medial temporal areas, whereby BD females had more volume than non-BD females, while males showed the inverse pattern of decreased volume in BD males and increased volume in non-BD males. AUDIT scores negatively correlated with volume in the right superior frontal cortex and precentral gyrus. CONCLUSIONS: These findings dovetail with previous studies reporting that a state effect of BD in college-aged drinkers and the severity of alcohol use are associated with volumetric alterations in the cortical and subcortical areas of the brain. Our study indicates that these widespread volumetric changes vary differentially by gender, suggesting either sexual dimorphic endophenotypic risk factors, or differential neurotoxic sensitivities for males and females.The study was supported by the Wellcome Trust grant to VV (093705/10/Z). We would like to thank the WBIC staff for their expertise and assistance with collecting the imaging data, and our participants for their time and commitment. The Behavioural and Clinical Neuroscience Institute is supported by the Wellcome Trust and Medical Research Council.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.nicl.2015.12.00
Blind study evaluation illustrates utility of the Ion PGM™ system for use in human identity DNA typing
Aim To perform a blind study to assess the capability of
the Ion Personal Genome Machine® (PGM™) system to sequence
forensically relevant genetic marker panels and to
characterize unknown individuals for ancestry and possible
relatedness.
Methods Twelve genomic samples were provided by a
third party for blinded genetic analysis. For these 12 samples,
the mitochondrial genome and three PGM™ panels
containing human identity single nucleotide polymorphisms
(SNPs), ancestry informative SNPs, and short tandem
repeats (STRs) were sequenced on the PGM™ system
and analyzed.
Results All four genetic systems were run and analyzed on
the PGM™ system in a reasonably quick time frame. Completeness
of genetic profiles, depth of coverage, strand
balance, and allele balance were informative metrics that
illustrated the quality and reliability of the data produced.
SNP genotypes allowed for identification of sex, paternal
lineage, and population ancestry. STR genotypes were
shown to be in complete concordance with genotypes
generated by standard capillary electrophoresis-based
technologies. Variants in the mitochondrial genome data
provided information on population background and maternal
relationships.
Conclusion All results from analysis of the 12 genomic
samples were consistent with sample information provided
by the sample providers at the end of the blinded study.
The relatively easy identification of intra-STR allele SNPs offered
the potential for increased discrimination power. The
promising nature of these results warrants full validation
studies of this massively parallel sequencing technology
and its further development for forensic data analysis
High pressure evolution of FeO electronic structure revealed by X-ray absorption
We report the first high pressure measurement of the Fe K-edge in hematite
(FeO) by X-ray absorption spectroscopy in partial fluorescence yield
geometry. The pressure-induced evolution of the electronic structure as
FeO transforms from a high-spin insulator to a low-spin metal is
reflected in the x-ray absorption pre-edge. The crystal field splitting energy
was found to increase monotonically with pressure up to 48 GPa, above which a
series of phase transitions occur. Atomic multiplet, cluster diagonalization,
and density-functional calculations were performed to simulate the pre-edge
absorption spectra, showing good qualitative agreement with the measurements.
The mechanism for the pressure-induced phase transitions of FeO is
discussed and it is shown that ligand hybridization significantly reduces the
critical high-spin/low-spin pressure.Comment: 5 pages, 4 figures and 1 tabl
A Less Toxic Heparin Antagonist—Low Molecular Weight Protamine
A new thirteen amino acid peptide, named low molecular weight protamine (LMWP), was obtained through the enzymatic digestion of native protamine. Both in vitro and in vivo results showed that LMWP fully maintained the heparin neutralization function of protamine but had much lower immunogenicity and antigenicity. Unlike protamine, neither LMWP nor LMWP/heparin complexes caused significant blood platelet aggregation in rats. These results suggest that LMWP can be used as a substitute for protamine for developing a new generation of nontoxic heparin antagonists.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45793/1/10541_2004_Article_462566.pd
Genetic Variants Associated With Vincristine‐Induced Peripheral Neuropathy in Two Populations of Children With Acute Lymphoblastic Leukemia
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149215/1/cpt1324_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149215/2/cpt1324.pd
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