241 research outputs found

    A Modified Price-Sales Ratio: A Useful Tool For Investors?

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    This study compares returns for stock portfolios using low price-to-earnings, price-to-book, price-to-sales, and price-to-sales ratios modified for profitability of sales and long-term debt. Non-financial companies with fiscal years ending on December 31 were included in a sample covering a 17-year period (1988-2004). The resulting sample was sub-divided into six groups by level of market capitalization.  A 25 stock portfolio was then compiled for each of six valuation ratios at each level of market capitalization. An index portfolio was also computed for each level of market capitalization.  First, the results of this study showed that additional expected returns based on firm size, measured by the market value of equity, is found only at the micro-cap level (less than 25millionmarketcapitalization).Theindexportfoliosofmini−caps(25 million market capitalization). The index portfolios of mini-caps (25-100 mill.), small caps (100−500mill.),andmid−caps(100-500 mill.), and mid-caps (500-$1 bill.) did not show any additional returns in comparison to the large-cap index portfolio. Second, no "value" portfolio for mid-caps provided significant returns above the index portfolio, suggesting a much greater level of market efficiency at this level of market capitalization.  Finally, the most significant findings of our study were that the portfolios constructed from low price-to-sales and modified price-to sales ratios performed as well or better than the more traditional price-to-earnings and price-to-book ratios. The price-to-sales ratio adjusted for profit margin (based on the prior three years) was statistically significant in three of six portfolios in comparison to the more traditional valuation ratios

    Analyse et prevention des troubles du cycle reproductif chez les caprins en region semi-aride dans le Nordeste bresilien.

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    Une enquete ecopathologique sur les avortements caprins en elevage traditionnel dans le nord-est du Bresil a permis de mettre en evidence une succession de troubles du cycle reproductif affectant le rendement zootechnique. L'analyse du cycle a fourni les elements necessaires a la formulation de mesures de prevention de ces troubles. Il s'agit, en manipulant le cycle reproductif, de realiser une meilleure adequation entre l'offre alimentaire, tres saisonnee, et la période de mises bas. Certaines mesures de conduite de la mise bas devraient entrainer une diminution importante de la mortalite des jeunes

    Comprendre et agir sur les avortements en elevage caprin: premier bilan et perspectives d'une etude ecopathologique conduite dans une petite region du Nordeste bresilien.

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    L'étude du probiéme des avortements des chévres constitue dans ce programme un théme de recherche appliquée dont /'objectif est de proposer rapidement des solutions techniques susceptibles d'en diminuer /'incidence. Ces conditions ont guidé le choix de Ia méthoeJologie employée

    Intramolecular monomer-on-monomer (MoM) mitsunobu cyclization for the synthesis of benzofused thiadiazepine-dioxides

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    The utilization of a monomer-on-monomer (MoM) intramolecular Mitsunobu cyclization reaction employing norbornenyl-tagged (Nb-tagged) reagents is reported for the synthesis of benzofused thiadiazepine-dioxides. Facile purification was achieved via ring-opening metathesis (ROM) polymerization initiated by one of three metathesis catalyst methods: (i) free metathesis catalyst, (ii) surface-initiated catalyst-armed silica, or (iii) surface-initiated catalyst-armed Co/C magnetic nanoparticles

    Validity of intradermal tuberculin testing for the screening of bovine tuberculosis in Madagascar

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    A sample survey with the objective of determining the prevalence of bovine tuberculosis by means of an intradermal tuberculin test was conducted in Madagascar and it was found that the prevalence rate varied from 0-30% by veterinary district. In order to estimate the true prevalence, the validity of the test was investigated by assessing its sensitivity and specificity in two groups of animals from two different regions, which were destined for slaughter. In the first group where the probability of non-infected animals should have been the highest, sensitivity was estimated at 0.52 ( n=21) and specificity at 0.99 ( n=79). In the second group selected on the basis of apparent ill health of the animals in a high-prevalence bovine tuberculosis area, sensitivity was estimated at 0.8 ( n=10) and specificity at 1 ( n=12). The results obtained from both groups of cattle were not combined for statistical purposes because the sensitivity of the skin test seemed to fluctuate in relation to the chronicity of the disease. These fluctuations are discussed. However, since the first group of zebu cattle was more representative of the cattle population across the country as a whole, its results were retained as operational parameters for further screening.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

    Acousto-optical Scanning-Based High-Speed 3D Two-Photon Imaging In Vivo.

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    Recording of the concerted activity of neuronal assemblies and the dendritic and axonal signal integration of downstream neurons pose different challenges, preferably a single recording system should perform both operations. We present a three-dimensional (3D), high-resolution, fast, acousto-optic two-photon microscope with random-access and continuous trajectory scanning modes reaching a cubic millimeter scan range (now over 950 × 950 × 3000 μm3) which can be adapted to imaging different spatial scales. The resolution of the system allows simultaneous functional measurements in many fine neuronal processes, even in dendritic spines within a central core (>290 × 290 × 200 μm3) of the total scanned volume. Furthermore, the PSF size remained sufficiently low (PSFx < 1.9 μm, PSFz < 7.9 μm) to target individual neuronal somata in the whole scanning volume for simultaneous measurement of activity from hundreds of cells. The system contains new design concepts: it allows the acoustic frequency chirps in the deflectors to be adjusted dynamically to compensate for astigmatism and optical errors; it physically separates the z-dimension focusing and lateral scanning functions to optimize the lateral AO scanning range; it involves a custom angular compensation unit to diminish off-axis angular dispersion introduced by the AO deflectors, and it uses a high-NA, wide-field objective and high-bandwidth custom AO deflectors with large apertures. We demonstrate the use of the microscope at different spatial scales by first showing 3D optical recordings of action potential back propagation and dendritic Ca2+ spike forward propagation in long dendritic segments in vitro, at near-microsecond temporal resolution. Second, using the same microscope we show volumetric random-access Ca2+ imaging of spontaneous and visual stimulation-evoked activity from hundreds of cortical neurons in the visual cortex in vivo. The selection of active neurons in a volume that respond to a given stimulus was aided by the real-time data analysis and the 3D interactive visualization accelerated selection of regions of interest

    Inducible Defenses with a "Twist": Daphnia barbata Abandons Bilateral Symmetry in Response to an Ancient Predator

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    Predation is one of the most important drivers of natural selection. In consequence a huge variety of anti-predator defenses have evolved in prey species. Under unpredictable and temporally variable predation pressure, the evolution of phenotypically plastic defensive traits is favored. These "inducible defenses", range from changes in behavior, life history, physiology to morphology and can be found in almost all taxa from bacteria to vertebrates. An important group of model organisms in ecological, evolutionary and environmental research, water fleas of the genus Daphnia (Crustacea: Cladocera), are well known for their ability to respond to predators with an enormous variety of inducible morphological defenses. Here we report on the "twist", a body torsion, as a so far unrecognized inducible morphological defense in Daphnia, expressed by Daphnia barbata exposed to the predatory tadpole shrimp Triops cancriformis. This defense is realized by a twisted carapace with the helmet and the tail spine deviating from the body axis into opposing directions, resulting in a complete abolishment of bilateral symmetry. The twisted morphotype should considerably interfere with the feeding apparatus of the predator, contributing to the effectiveness of the array of defensive traits in D. barbata. As such this study does not only describe a completely novel inducible defense in the genus Daphnia but also presents the first report of a free living Bilateria to flexibly respond to predation risk by abandoning bilateral symmetry
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