EVALUATION OF GASTROPROTECTIVE POTENTIAL OF CAJANUS CAJAN SEEDS EXTRACT ON ETHANOL-INDUCED GASTRIC ULCER IN ALBINO RATS

Objective: The present study was undertaken to evaluate the gastroprotective potential of Cajanus cajan seed aqueous extract (CCSE) on experimentally induced gastric ulcer in albino rats. Methods: Preliminary acute toxicity study was conducted to determine the oral median lethal dose (LD50). Twenty (20) male rats divided into 5 groups (A-E) of 4 animals each were used. Group A (normal control) and B (ulcer model) received 10ml/kg distilled water. Groups C, D and E received Cimetidine (100mg/kg b.w intraperitoneally), 250mg/kg and 500mg/kg b.w of CCSE orally respectively, once daily for seven (7) days. On Day 8, gastric ulcers were induced in groups B – E using 80% ethanol (1ml/rat) prior to sacrifice. Ulcer indices were determined on excised stomach tissues prior to further processing for histological examination. Results: The LD50 of CCSE is greater than 5g/kg b.w. Cimetidine and CCSE treatments showed statistically significant decrease (p<0.05) in ulcer indices compared to group B (ulcer model). Histological features revealed noticeable preservation of the gastric mucosa in consistence with the macroscopical findings. Conclusion: The present study revealed that C. cajan seed extract possesses gastroprotective properties against ethanol-induced gastric ulcers

Cosmological Systematics Beyond Nuisance Parameters : Form Filling Functions

In the absence of any compelling physical model, cosmological systematics are often misrepresented as statistical effects and the approach of marginalising over extra nuisance systematic parameters is used to gauge the effect of the systematic. In this article we argue that such an approach is risky at best since the key choice of function can have a large effect on the resultant cosmological errors. As an alternative we present a functional form filling technique in which an unknown, residual, systematic is treated as such. Since the underlying function is unknown we evaluate the effect of every functional form allowed by the information available (either a hard boundary or some data). Using a simple toy model we introduce the formalism of functional form filling. We show that parameter errors can be dramatically affected by the choice of function in the case of marginalising over a systematic, but that in contrast the functional form filling approach is independent of the choice of basis set. We then apply the technique to cosmic shear shape measurement systematics and show that a shear calibration bias of |m(z)|< 0.001(1+z)^0.7 is required for a future all-sky photometric survey to yield unbiased cosmological parameter constraints to percent accuracy. A module associated with the work in this paper is available through the open source iCosmo code available at http://www.icosmo.org .Comment: 24 pages, 18 figures, accepted to MNRA

Cosmological systematics beyond nuisance parameters: form-filling functions

In the absence of any compelling physical model, cosmological systematics are often misrepresented as statistical effects and the approach of marginalizing over extra nuisance systematic parameters is used to gauge the effect of the systematic. In this article, we argue that such an approach is risky at best since the key choice of function can have a large effect on the resultant cosmological errors. As an alternative we present a functional form-filling technique in which an unknown, residual, systematic is treated as such. Since the underlying function is unknown, we evaluate the effect of every functional form allowed by the information available (either a hard boundary or some data). Using a simple toy model, we introduce the formalism of functional form filling. We show that parameter errors can be dramatically affected by the choice of function in the case of marginalizing over a systematic, but that in contrast the functional form-filling approach is independent of the choice of basis set. We then apply the technique to cosmic shear shape measurement systematics and show that a shear calibration bias of |m(z)| ≲ 10−3 (1 +z)0.7 is required for a future all-sky photometric survey to yield unbiased cosmological parameter constraints to per cent accuracy. A module associated with the work in this paper is available through the open source icosmo code available at http://www.icosmo.or

Essai comparatif d'efficacité des deux souches vaccinale T1/44 et T1st contre la préripneumonie contagieuse bovine

La péripneumonie est une maladie infectieuse qui touche uniquement les bovidés et connaît actuellement une recrudescence en Afrique. Dans le passé de nombreux pays ont pu contrôler la maladie, voire l'éradiquer, grâce à une prophylaxie médicale basée sur l'utilisation de deux souches vaccinales : T1/44 et sa variante streptomycino-résistante T1sr. Des échecs récents ont pu jeter un doute sur l'identité et l'efficacité de la souche T1sr. Depuis, son identité a été confirmée. Il devenait indispensable de vérifier son efficacité dans des conditions contrôlées. Les deux souches ont été utilisées en primovaccination à la dose minimum recommandée, soit 10&lt;+&gt;7&lt;+&gt; mycoplasmes par dose vaccinale. La reproduction expérimentale de la maladie a été réalisée par intubation endobronchique de 40 zébus du Nord-Cameroun qui ont servi à infecter par contact des animaux vaccinés et des animaux témoins. Tous les animaux ont fait l'objet d'un suivi clinique et sérologique. La transmission de la maladie a pleinement réussi et près de 40 p. 100 des animaux témoins ont succombé à la péripneumonie. La mortalité a été inférieure chez les animaux vaccinés mais la différence est à la limite de la signification statistique (p = 0,054). Quelle que soit la souche, la protection conférée par la vaccination, calculée sur la réduction de la mortalité, avoisine 37 p. 100 seulement. Il est difficile de comparer ces résultats avec des essais anciens qui étaient pratiquement tous réalisés avec des doses vaccinales beaucoup plus élevées et qui utilisaient une souche d'épreuve isolée en Australie. Les résultats obtenus soulignent le caractère partiel de la protection conférée par la vaccination actuellement pratiquée. Ils appellent d'une part à une meilleure définition des stratégies actuelles de lutte contre la péripneumonie et d'autre part à la mise au point de vaccins plus efficaces. (Résumé d'auteur

Magnetism: the Driving Force of Order in CoPt. A First-Principles Study

CoPt or FePt equiatomic alloys order according to the tetragonal L10 structure which favors their strong magnetic anisotropy. Conversely magnetism can influence chemical ordering. We present here {\it ab initio} calculations of the stability of the L10 and L12 structures of Co-Pt alloys in their paramagnetic and ferromagnetic states. They show that magnetism strongly reinforces the ordering tendencies in this system. A simple tight-binding analysis allows us to account for this behavior in terms of some pertinent parameters

Cosmic shear requirements on the wavelength-dependence of telescope point spread functions

Cosmic shear requires high precision measurement of galaxy shapes in the presence of the observational Point Spread Function (PSF) that smears out the image. The PSF must therefore be known for each galaxy to a high accuracy. However, for several reasons, the PSF is usually wavelength dependent, therefore the differences between the spectral energy distribution of the observed objects introduces further complexity. In this paper we investigate the effect of the wavelength-dependence of the PSF, focusing on instruments in which the PSF size is dominated by the diffraction-limit of the telescope and which use broad-band filters for shape measurement. We first calculate biases on cosmological parameter estimation from cosmic shear when the stellar PSF is used uncorrected. Using realistic galaxy and star spectral energy distributions and populations and a simple three-component circular PSF we find that the colour-dependence must be taken into account for the next generation of telescopes. We then consider two different methods for removing the effect (i) the use of stars of the same colour as the galaxies and (ii) estimation of the galaxy spectral energy distribution using multiple colours and using a telescope model for the PSF. We find that both of these methods correct the effect to levels below the tolerances required for per-cent level measurements of dark energy parameters. Comparison of the two methods favours the template-fitting method because its efficiency is less dependent on galaxy redshift than the broad-band colour method and takes full advantage of deeper photometry.Comment: 10 pages, 8 figures, version accepted for publication in MNRA

Weak gravitational lensing with DEIMOS

We introduce a novel method for weak-lensing measurements, which is based on a mathematically exact deconvolution of the moments of the apparent brightness distribution of galaxies from the telescope's PSF. No assumptions on the shape of the galaxy or the PSF are made. The (de)convolution equations are exact for unweighted moments only, while in practice a compact weight function needs to be applied to the noisy images to ensure that the moment measurement yields significant results. We employ a Gaussian weight function, whose centroid and ellipticity are iteratively adjusted to match the corresponding quantities of the source. The change of the moments caused by the application of the weight function can then be corrected by considering higher-order weighted moments of the same source. Because of the form of the deconvolution equations, even an incomplete weighting correction leads to an excellent shear estimation if galaxies and PSF are measured with a weight function of identical size. We demonstrate the accuracy and capabilities of this new method in the context of weak gravitational lensing measurements with a set of specialized tests and show its competitive performance on the GREAT08 challenge data. A complete C++ implementation of the method can be requested from the authors.Comment: 7 pages, 3 figures, fixed typo in Eq. 1

Free health care for under-fives, expectant and recent mothers? Evaluating the impact of Sierra Leone's free health care initiative.

This study evaluates the impact of Sierra Leone's 2010 Free Health Care Initiative (FHCI). It uses two nationally representative surveys to identify the impact of the policy on utilisation of maternal care services by pregnant women and recent mothers as well as the impact on curative health care services and out-of-pocket payments for consultation and prescription in children under the age of 5 years. A Regression Discontinuity Design (RDD) is applied in the case of young children and a before-after estimation approach, adjusted for time trends in the case of expectant and recent mothers. Our results suggest that children affected by the FHCI have a lower probability of incurring any health expenditure in public, non-governmental and missionary health facilities. However, a proportion of eligible children are observed to incur some health expenditure in participating facilities with no impact of the policy on the level of out-of-pocket health expenditure. Similarly, no impact is observed with the utilisation of services in these facilities. Utilisation of informal care is observed to be higher among non-eligible children while in expectant and recent mothers, we find substantial but possibly transient increases in the use of key maternal health care services in public facilities following the implementation of the FHCI. The diminishing impact on utilisation mirrors experience in other countries that have implemented free health care initiatives and demonstrates the need for greater domestic and international efforts to ensure that resources are sufficient to meet increasing demand and monitor the long run impact of these policies

Indium selenide: An insight into electronic band structure and surface excitations

We have investigated the electronic response of single crystals of indium selenide by means of angle-resolved photoemission spectroscopy, electron energy loss spectroscopy and density functional theory. The loss spectrum of indium selenide shows the direct free exciton at similar to 1.3 eV and several other peaks, which do not exhibit dispersion with the momentum. The joint analysis of the experimental band structure and the density of states indicates that spectral features in the loss function are strictly related to single-particle transitions. These excitations cannot be considered as fully coherent plasmons and they are damped even in the optical limit, i.e. for small momenta. The comparison of the calculated symmetry-projected density of states with electron energy loss spectra enables the assignment of the spectral features to transitions between specific electronic states. Furthermore, the effects of ambient gases on the band structure and on the loss function have been probed