6,693 research outputs found
Neuron impairment or loss in brain may be responsible for type 2 diabetes and essential hypertension
Type 2 diabetes and essential hypertension are both very common chronic diseases. Type 2 diabetes is often associated with hypertension, but the exact causes of them are unknown. Here, based on recent investigations, we will look at the pathogenesis of these two diseases in a new light
Multiple Fermi pockets revealed by Shubnikov-de Haas oscillations in WTe2
We use magneto-transport measurements to investigate the electronic structure
of WTe2 single crystals. A non-saturating and parabolic magnetoresistance is
observed in the temperature range between 2.5 to 200 K and magnetic fields up
to 8 T. Shubnikov - de Haas oscillations with beating patterns are observed.
The fast Fourier transform of the SdH oscillations reveals three oscillation
frequencies, corresponding to three pairs of Fermi pockets with comparable
effective masses , m* ~ 0.31 me. By fitting the Hall resistivity, we infer the
presence of one pair of electron pockets and two pairs of hole pockets,
together with nearly perfect compensation of the electron-hole carrier
concentration. These magnetotransport measurements reveal the complex
electronic structure in WTe2, explaining the nonsaturating magnetoresistance.Comment: Submitted to journal on 1 April, 2015, 4 Figure
Determinants of Consumer Behavior in an e-Commerce Environment
Online specialty food and beverage marketing has developed rapidly in the last decade. With the obvious increase in the sales income, researchers showed more and more interests in this promising market. Previous studies in this field primarily focused on the demographic profiling of the online specialty food consumers as well as initial analysis in the factors that motivate their purchase behavior. However, it is far from fully explaining consumer\u27s online shopping activities. In order to solve these problems, new methods should be attempted to determine the factors influencing consumer\u27s online buying behavior. A cluster analysis was developed to identify what kind of consumers have a higher preference of shopping online. And this analysis is based on consumer\u27s lifestyle characteristics, which are assumed to be the determinants of their online shopping behavior. By identifying the consumer groups with a relatively high propensity of purchasing on the Internet, this research will provide improved information for companies marketing food and beverage products online and strengthen their abilities to develop effective marketing strategies. The data for this study were obtained from an online survey conducted from September 27th to October 25th, 2001. First a factor analysis was applied to the forty-two lifestyle variables and ten factors were extracted to represent them. Then the factor scores for each observation, an output data set of factor analysis, were submitted to a hierarchical cluster analysis using Ward\u27s minimum-variance clustering method. As a result, lifestyle segmentations of the online specialty food and beverage market were obtained. Each segment was given a name based on the factor that has the highest loading on the particular group so as to emphasize its characteristics. Further analysis has also been done in order to compare the other related characteristics among the groups
Constraints on the Asymptotic Baryon Fractions of Galaxy Clusters at Large Radii
While X-ray measurements have so far revealed an increase in the
volume-averaged baryon fractions of galaxy clusters with cluster radii
, should asymptotically reach a universal value ,
provided that clusters are representative of the Universe. In the framework of
hydrostatic equilibrium for intracluster gas, we have derived the necessary
conditions for : The X-ray surface brightness profile
described by the model and the temperature profile approximated by the
polytropic model should satisfy and
for , respectively, which sets
a stringent limit to the polytropic index: . In particular, a
mildly increasing temperature with radius is required if the observationally
fitted parameter is in the range . It is likely that a
reliable determination of the universal baryon fraction can be achieved in the
small clusters because the disagreement between the exact and
asymptotic baryon fractions for clusters with breaks down at rather
large radii (\ga30r_c) where hydrostatic equilibrium has probably become
inapplicable. We further explore how to obtain the asymptotic value
of baryon fraction from the X-ray measurement made primarily over
the finite central region of a cluster. We demonstrate our method using a
sample of 19 strong lensing clusters, which enables us to place a useful
constraint on : .
An optimal estimate of based on three cooling flow clusters with
or .Comment: 6 pages + 4 figures; accepted for publication in MNRA
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