742 research outputs found
The induction of obesity in the rat with bipiperidyl mustard
Lesions in the ventromedial region of the hypothalamus were shown by Hetherington &
Ranson (1940) to produce hyperphagia and obesity in the rat. The chemical agents gold
thioglucose (GTG; Brecher & Waxler, 1949) and bipiperidyl mustard (BPM; Rutman
et al. 1966) which are widely used to induce obesity in mice also produce lesions in this
region of the hypothalamus (Marshall et al. 1955; Rutman et al. 1966). The use of GTG to
induce obesity in the rat has proved to be unsuitable for widespread use and would be very
expensive (Mayer & Marshall, 1956; Wagner & de Groot 1963). Bunyan et al. (1976) have
shown that monosodium glutamate administered to newborn rats and mice produces
obesity without hyperphagia.
Miller (1979) has recently reviewed non-genetic models of obesity and has summarized
methods which produce a high proportion of obese mice, with low mortality, using monosodium
glutamate or gold thioglucose, but although he mentions the use of BPM in mice
he does not recommend it because it is carcinogenic and difficult to obtain. He concludes
that in all the models of obesity efficiency of energy utilization is the most important factor
in the aetiology of the obesity.
We now report an experiment in which obesity has been induced in the rat without mortality
and inexpensively using BPM
Effects of different needles and substrates on CuInS2 deposited by electrostatic spray deposition
Copper indium disulphide (CuInS2) thin films were deposited using the electrostatic spray deposition method. The effects of applied voltage and solution flow rate on the aerosol cone shape, film composition, surface morphology and current conversion were investigated. The effect of aluminium substrates and transparent fluorine doped tin oxide (SnO2:F) coated glass substrates on the properties of as-deposited CuInS2 films were analysed. An oxidation process occurs during the deposition onto the metallic substrates which forms an insulating layer between the photoactive film and substrate. The effects of two different spray needles on the properties of the as-deposited films were also studied. The results reveal that the use of a stainless steel needle results in contamination of the film due to the transfer of metal impurities through the spray whilst this is not seen for the glass needle. The films were characterised using a number of different analytical techniques such as X-ray diffraction, scanning electron microscopy, Rutherford back-scattering and secondary ion mass spectroscopy and opto-electronic measurements
Percolation model for structural phase transitions in LiHIO mixed crystals
A percolation model is proposed to explain the structural phase transitions
found in LiHIO mixed crystals as a function of the
concentration parameter . The percolation thresholds are obtained from Monte
Carlo simulations on the specific lattices occupied by lithium atoms and
hydrogen bonds. The theoretical results strongly suggest that percolating
lithium vacancies and hydrogen bonds are indeed responsible for the solid
solution observed in the experimental range .Comment: 4 pages, 2 figure
Tissue chemistry and carbon allocation in seedlings of Pinus palustris subjected to elevated atmospheric CO2 and water stress
Longleaf pine (Pinus palustris Mill.) seedlings
were grown in 45-1 pots and exposed to ambient or elevated
(365 or 730 uamol CO2 mol-1 ) CO2 concentration in open-top
chambers for 20 months. Two water-stress treatments (target
values of -0.5 or -1.5 MPa xylem pressure potential) were
imposed 19 weeks after initiation of the study. At harvest,
tissues (needles, stems, taproots, coarse roots, and fine roots)
were analyzed for carbon (C), nitrogen (N), nonpolar extractives
(fats, waxes, and oils), nonstructural carbohydrates (sugars
and starch), structural components (cellulose and lignin),
and tannins. The greatest dry weights and lowest N concentrations
occurred in tissues of plants grown at elevated CO 2 or
with adequate water.
Although allocation of C fractions among tissues was generally
unaffected by treatments, concentrations of the analyzed
compounds were influenced by treatments in needles and
taproots, but not in stems and lateral roots. Needles and taproots
of plants exposed to elevated CO2 had increased concentrations
of nonstructural carbohydrates. Among plant tissues,
elevated CO2 caused reductions in structural C concentrations
and foliar concentrations of fats, waxes and oils
Updated guidelines for gene nomenclature in wheat
The last decade has seen a proliferation in genomic resources for wheat, including reference- and pan-genome assemblies with gene annotations, which provide new opportunities to detect, characterise, and describe genes that influence traits of interest. The expansion of genetic information has supported growth of the wheat research community and catalysed strong interest in the genes that control agronomically important traits, such as yield, pathogen resistance, grain quality, and abiotic stress tolerance. To accommodate these developments, we present an updated set of guidelines for gene nomenclature in wheat. These guidelines can be used to describe loci identified based on morphological or phenotypic features or to name genes based on sequence information, such as similarity to genes characterised in other species or the biochemical properties of the encoded protein. The updated guidelines provide a flexible system that is not overly prescriptive but provides structure and a common framework for naming genes in wheat, which may be extended to related cereal species. We propose these guidelines be used henceforth by the wheat research community to facilitate integration of data from independent studies and allow broader and more efficient use of text and data mining approaches, which will ultimately help further accelerate wheat research and breeding.EEA PergaminoFil: Boden, S. A. University of Adelaide. Waite Research Institute. School of Agriculture, Food and Wine; AustraliaFil: McIntosh, R .A. University of Sydney. School of Life and Environmental Sciences. Plant Breeding Institute; AustraliaFil: Uauy, C. Norwich Research Park. John Innes Centre; Reino UnidoFil: Krattinger, S. G. King Abdullah University of Science and Technology. Biological and Environmental Science and Engineering Division. Plant Science Program; Arabia SauditaFil: Krattinger, S. G. The Wheat Initiative; AlemaniaFil: Dubcovsky, J. University of California. Department of Plant Science; Estados UnidosFil: Dubcovsky, J. The Wheat Initiative; AlemaniaFil: Rogers, W.J. Universidad Nacional del Centro de La Provincia de Buenos Aires. Facultad de Agronomía (CIISAS, CIC-BIOLAB AZUL, CONICET-INBIOTEC, CRESCA). Departamento de Biología Aplicada; ArgentinaFil: Rogers, W.J. The Wheat Initiative; AlemaniaFIL: Xia, X. C. Chinese Academy of Agricultural Sciences. National Wheat Improvement Centre. Institute of Crop Science; ChinaFil: Badaeva, E. D. Russian Academy of Sciences. N.I. Vavilov Institute of General Genetics; RusiaFil: Bentley, A. R. International Maize and Wheat Improvement Center (CIMMYT); MéxicoFil: Bentley, A. R. The Wheat Initiative; AlemaniaFil: Brown-Guedira, G. North Carolina State University. USDA-ARS Plant Science Research; Estados UnidosFil: Brown-Guedira, G. The Wheat Initiative; AlemaniaFil: González, Fernanda G. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Sección Ecofisiología; ArgentinaFil: González, Fernanda G. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires (CITNOBA, CONICET-UNNOBA-UNSADA); ArgentinaFil: González, Fernanda G. The Wheat Initiative; AlemaniaFil: Zhang, Y. Fudan University. School of Life Sciences. Institute of Plant Biology. Collaborative Innovation Center of Genetics and Development. State Key Laboratory of Genetic Engineering; Chin
Analytical results for coupled map lattices with long-range interactions
We obtain exact analytical results for lattices of maps with couplings that
decay with distance as . We analyze the effect of the coupling
range on the system dynamics through the Lyapunov spectrum. For lattices whose
elements are piecewise linear maps, we get an algebraic expression for the
Lyapunov spectrum. When the local dynamics is given by a nonlinear map, the
Lyapunov spectrum for a completely synchronized state is analytically obtained.
The critical lines characterizing the synchronization transition are determined
from the expression for the largest transversal Lyapunov exponent. In
particular, it is shown that in the thermodynamical limit, such transition is
only possible for sufficiently long-range interactions, namely, for , where is the lattice dimension.Comment: 4 pages, 2 figures, corrections included. Phys. Rev. E 68, 045202(R)
(2003); correction in pres
YREC: The Yale Rotating Stellar Evolution Code
The stellar evolution code YREC is outlined with emphasis on its applications
to helio- and asteroseismology. The procedure for calculating calibrated solar
and stellar models is described. Other features of the code such as a non-local
treatment of convective core overshoot, and the implementation of a
parametrized description of turbulence in stellar models, are considered in
some detail. The code has been extensively used for other astrophysical
applications, some of which are briefly mentioned at the end of the paper.Comment: 10 pages, 2 figures, ApSS accepte
Identification of novel small molecule Beclin 1 mimetics activating autophagy
Anti-apoptotic proteins Bcl-2 and Bcl-xL could block autophagy by binding to Beclin 1 protein, an essential inducer of autophagy. Compounds mimicking Beclin 1 might be able to disrupt Bcl-xL/2-Beclin 1 interaction, free out Beclin 1, and thus trigger autophagy. In order to identify small molecule Beclin 1 mimetics, a fluorescence polarization-based high-throughput screening of 50,316 compounds was carried out with a Z' score of 0.82 ± 0.05, and an outcome of 58 hits. After the structure analysis, three acridine analogues were unveiled and confirmed using the fluorescence polarization assay and the surface plasmon resonance assay. Moreover, a set of 17 additional acridine analogues was prepared and tested. Compound 7 showed selectivity for Bcl-xL (KD = 6.5 μM) over Bcl-2 (KD = 160 μM) protein, and potent cytotoxicity (nanomolar scale) in PC-3, PC-3a and DU145 prostate cancer cells. Furthermore, induction of autophagy was also demonstrated in PC-3 and PC-3a cells treated with some acridine compounds by LC3 conversion immunoblotting and LC3 fluorescence microscopy. These Beclin 1 mimetics will be invaluable tools for developing novel autophagy inducers, better understanding the roles of autophagy in cancer, and will contribute to cancer therapy
Radiotherapy exposure directly damages the uterus and causes pregnancy loss
Female cancer survivors are significantly more likely to experience infertility than the general population. It is well established that chemotherapy and radiotherapy can damage the ovary and compromise fertility, yet the ability of cancer treatments to induce uterine damage, and the underlying mechanisms, have been understudied. Here, we show that in mice total-body γ-irradiation (TBI) induced extensive DNA damage and apoptosis in uterine cells. We then transferred healthy donor embryos into ovariectomized adolescent female mice that were previously exposed to TBI to study the impacts of radiotherapy on the uterus independent from effects to ovarian endocrine function. Following TBI, embryo attachment and implantation were unaffected, but fetal resorption was evident at midgestation in 100% of dams, suggesting failed placental development. Consistent with this hypothesis, TBI impaired the decidual response in mice and primary human endometrial stromal cells. TBI also caused uterine artery endothelial dysfunction, likely preventing adequate blood vessel remodeling in early pregnancy. Notably, when pro-apoptotic protein Puma-deficient (Puma–/–) mice were exposed to TBI, apoptosis within the uterus was prevented, and decidualization, vascular function, and pregnancy were restored, identifying PUMA-mediated apoptosis as a key mechanism. Collectively, these data show that TBI damages the uterus and compromises pregnancy success, suggesting that optimal fertility preservation during radiotherapy may require protection of both the ovaries and uterus. In this regard, inhibition of PUMA may represent a potential fertility preservation strategy.Meaghan J. Griffiths, Sarah A. Marshall, Fiona L. Cousins, Lauren R. Alesi, Jordan Higgins, Saranya Giridharan, Urooza C. Sarma, Ellen Menkhorst, Wei Zhou, Alison S. Care, Jacqueline F. Donoghue, Sarah J. Holdsworth-Carson, Peter A.W. Rogers, Evdokia Dimitriadis, Caroline E. Gargett, Sarah A. Robertson, Amy L. Winship, and Karla J. Hut
Fitting the integrated Spectral Energy Distributions of Galaxies
Fitting the spectral energy distributions (SEDs) of galaxies is an almost
universally used technique that has matured significantly in the last decade.
Model predictions and fitting procedures have improved significantly over this
time, attempting to keep up with the vastly increased volume and quality of
available data. We review here the field of SED fitting, describing the
modelling of ultraviolet to infrared galaxy SEDs, the creation of
multiwavelength data sets, and the methods used to fit model SEDs to observed
galaxy data sets. We touch upon the achievements and challenges in the major
ingredients of SED fitting, with a special emphasis on describing the interplay
between the quality of the available data, the quality of the available models,
and the best fitting technique to use in order to obtain a realistic
measurement as well as realistic uncertainties. We conclude that SED fitting
can be used effectively to derive a range of physical properties of galaxies,
such as redshift, stellar masses, star formation rates, dust masses, and
metallicities, with care taken not to over-interpret the available data. Yet
there still exist many issues such as estimating the age of the oldest stars in
a galaxy, finer details ofdust properties and dust-star geometry, and the
influences of poorly understood, luminous stellar types and phases. The
challenge for the coming years will be to improve both the models and the
observational data sets to resolve these uncertainties. The present review will
be made available on an interactive, moderated web page (sedfitting.org), where
the community can access and change the text. The intention is to expand the
text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics &
Space Scienc
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