1,743 research outputs found
Glucose Inhibition of Cellulose Synthesis by Pyrenochaeta terrestris
The rate of synthesis of Pyrenochacta terrestris cellulase was determined on the substrates of glucose, cellulose, and cellulose + glucose. Enzyme production was rapid on cellulose, almost negligible on glucose, and intermediate on cellulose + glucose. On the latter substrate, cellulase appeared after the near exhaustion of glucose. The authors suggest that extremely low concentrations of soluble carbohydrate regulate cellulase synthesis
Topology of amorphous tetrahedral semiconductors on intermediate lengthscales
Using the recently-proposed ``activation-relaxation technique'' for
optimizing complex structures, we develop a structural model appropriate to
a-GaAs which is almost free of odd-membered rings, i.e., wrong bonds, and
possesses an almost perfect coordination of four. The model is found to be
superior to structures obtained from much more computer-intensive tight-binding
or quantum molecular-dynamics simulations. For the elemental system a-Si, where
wrong bonds do not exist, the cost in elastic energy for removing odd-membered
rings is such that the traditional continuous-random network is appropriate.
Our study thus provides, for the first time, direct information on the nature
of intermediate-range topology in amorphous tetrahedral semiconductors.Comment: 4 pages, Latex and 2 postscript figure
A systematic review and meta-synthesis of the impact of low back pain on people's lives
Copyright @ 2014 Froud et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited.Background - Low back pain (LBP) is a common and costly problem that many interpret within a biopsychosocial model. There is renewed concern that core-sets of outcome measures do not capture what is important. To inform debate about the coverage of back pain outcome measure core-sets, and to suggest areas worthy of exploration within healthcare consultations, we have synthesised the qualitative literature on the impact of low back pain on peopleâs lives.
Methods - Two reviewers searched CINAHL, Embase, PsycINFO, PEDro, and Medline, identifying qualitative studies of peopleâs experiences of non-specific LBP. Abstracted data were thematic coded and synthesised using a meta-ethnographic, and a meta-narrative approach.
Results - We included 49 papers describing 42 studies. Patients are concerned with engagement in meaningful activities; but they also want to be believed and have their experiences and identity, as someone âdoing battleâ with pain, validated. Patients seek diagnosis, treatment, and cure, but also reassurance of the absence of pathology. Some struggle to meet social expectations and obligations. When these are achieved, the credibility of their pain/disability claims can be jeopardised. Others withdraw, fearful of disapproval, or unable or unwilling to accommodate social demands. Patients generally seek to regain their pre-pain levels of health, and physical and emotional stability. After time, this can be perceived to become unrealistic and some adjust their expectations accordingly.
Conclusions - The social component of the biopsychosocial model is not well represented in current core-sets of outcome measures. Clinicians should appreciate that the broader impact of low back pain includes social factors; this may be crucial to improving patientsâ experiences of health care. Researchers should consider social factors to help develop a portfolio of more relevant outcome measures.Arthritis Research U
Bioinformatic Analysis of Gene Sets Regulated by Ligand-Activated and Dominant-Negative Peroxisome Proliferator-Activated Receptor  in Mouse Aorta
Drugs that activate PPARÎł improve glucose sensitivity and lower blood pressure, whereas dominant negative mutations in PPARÎł cause severe insulin resistance and hypertension. We hypothesize that these PPARÎł mutants regulate target genes opposite to that of ligand-mediated activation and tested this hypothesis on a genome-wide scale
Structural study of an amorphous NiZr2 alloy by anomalous wide angle X-ray scattering and Reverse Monte Carlo simulations
The local atomic structure of an amorphous NiZr2 alloy was investigated using
the anomalous wide-angle x-ray scattering (AWAXS), differential anomalous
scattering (DAS) and reverse Monte Carlo (RMC) simulations techniques. The
AWAXS measurements were performed at eight different incident photon energies,
including some close to the Ni and Zr K edges. From the measurements eight
total structure factor S(K,E) were derived. Using the AWAXS data four
differential structure factors DSFi(K,Em,En) were derived, two about the Ni and
Zr edges. The partial structure factors SNi-Ni(K), SNi-Zr(K) and SZr-Zr(K) were
estimated by using two different methods. First, the S(K,E) and DSFi(K,Em,En)
factors were combined and used in a matrix inversion process. Second, three
S(K,E) factors were used as input data in the RMC technique. The coordination
numbers and interatomic distances for the first neighbors extracted from the
partial structure factors obtained by these two methods show a good agreement.
By using the three-dimensional structure derived from the RMC simulations, the
bond-angle distributions were calculated and they suggest the presence of
distorted triangular-faced polyhedral units in the amorphous NiZr2 structure.
We have used the Warren chemical short-range order parameter to evaluate the
chemical short-range order for the amorphous NiZr2 alloy and for the NiZr2
compound. The calculated values show that the chemical short-range order found
in these two materials is similar to that found in a solid solution.Comment: Submitted to Phys. Rev. B, 8 figure
Recommended from our members
The Met Office Global Coupled model 3.0 and 3.1 (GC3.0 & GC3.1) configurations
The Global Coupled 3 (GC3) configuration of the Met Office Unified Model is presented. Amongst other applications, GC3 is the basis of the United Kingdom's submission to the Coupled Model Intercomparison Project 6 (CMIP6). This paper documents the model components that make up the configuration (although the scientific description of these components are in companion papers), and details the coupling between them. The performance of GC3 is assessed in terms of mean biases and variability in long climate simulations using present-day forcing. The suitability of the configuration for predictability on shorter timescales (weather and seasonal forecasting) is also briefly discussed. The performance of GC3 is compared against GC2, the previous Met Office coupled model configuration, and against an older configuration (HadGEM2-AO) which was the submission to CMIP5.
In many respects, the performance of GC3 is comparable with GC2, however there is a notable improvement in the Southern Ocean warm sea surface temperature bias which has been reduced by 75%, and there are improvements in cloud amount and some aspects of tropical variability. Relative to HadGEM2-AO, many aspects of the present-day climate are improved in GC3 including tropospheric and stratospheric temperature structure, most aspects of tropical and extra-tropical variability and top-of-atmosphere & surface fluxes. A number of outstanding errors are identified including a residual asymmetric sea surface temperature bias (cool northern hemisphere, warm Southern Ocean), an overly strong global hydrological cycle and insufficient European blocking
The LAGUNA design study- towards giant liquid based underground detectors for neutrino physics and astrophysics and proton decay searches
The feasibility of a next generation neutrino observatory in Europe is being
considered within the LAGUNA design study. To accommodate giant neutrino
detectors and shield them from cosmic rays, a new very large underground
infrastructure is required. Seven potential candidate sites in different parts
of Europe and at several distances from CERN are being studied: Boulby (UK),
Canfranc (Spain), Fr\'ejus (France/Italy), Pyh\"asalmi (Finland),
Polkowice-Sieroszowice (Poland), Slanic (Romania) and Umbria (Italy). The
design study aims at the comprehensive and coordinated technical assessment of
each site, at a coherent cost estimation, and at a prioritization of the sites
within the summer 2010.Comment: 5 pages, contribution to the Workshop "European Strategy for Future
Neutrino Physics", CERN, Oct. 200
Colloquium: Statistical mechanics of money, wealth, and income
This Colloquium reviews statistical models for money, wealth, and income
distributions developed in the econophysics literature since the late 1990s. By
analogy with the Boltzmann-Gibbs distribution of energy in physics, it is shown
that the probability distribution of money is exponential for certain classes
of models with interacting economic agents. Alternative scenarios are also
reviewed. Data analysis of the empirical distributions of wealth and income
reveals a two-class distribution. The majority of the population belongs to the
lower class, characterized by the exponential ("thermal") distribution, whereas
a small fraction of the population in the upper class is characterized by the
power-law ("superthermal") distribution. The lower part is very stable,
stationary in time, whereas the upper part is highly dynamical and out of
equilibrium.Comment: 24 pages, 13 figures; v.2 - minor stylistic changes and updates of
references corresponding to the published versio
Comparison of the Tax System Progressivity Over Time: Theory and Application with Mexican Data
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