329 research outputs found

    Group-galaxy correlations in redshift space as a probe of the growth of structure

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    We investigate the use of the cross-correlation between galaxies and galaxy groups to measure redshift-space distortions (RSD) and thus probe the growth rate of cosmological structure. This is compared to the classical approach based on using galaxy auto-correlation. We make use of realistic simulated galaxy catalogues that have been constructed by populating simulated dark matter haloes with galaxies through halo occupation prescriptions. We adapt the classical RSD dispersion model to the case of the group-galaxy cross-correlation function and estimate the RSD parameter β\beta by fitting both the full anisotropic correlation function ξ(rp,π)\xi(r_p,\pi) and its multipole moments. In addition, we define a modified version of the latter statistics by truncating the multipole moments to exclude strongly non-linear distortions at small transverse scales. We fit these three observable quantities in our set of simulated galaxy catalogues and estimate statistical and systematic errors on β\beta for the case of galaxy-galaxy, group-group, and group-galaxy correlation functions. When ignoring off-diagonal elements of the covariance matrix in the fitting, the truncated multipole moments of the group-galaxy cross-correlation function provide the most accurate estimate, with systematic errors below 3% when fitting transverse scales larger than 10Mpc/h10Mpc/h. Including the full data covariance enlarges statistical errors but keep unchanged the level of systematic error. Although statistical errors are generally larger for groups, the use of group-galaxy cross-correlation can potentially allow the reduction of systematics while using simple linear or dispersion models.Comment: 18 pages, 16 figure

    Characterizations of Distributions by Expected Values of Lower Record Statistics with Spacing

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    The characterizations of a certain class of probability distributions are established through conditional expectation of lower record values when the conditioned record value may not be the adjacent one. Some of its important deductions are also discussed

    Modelling & Simulation of PV Module Connected with Three-Port DC Converter

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    Of the world’s electricity is being generated through conventional sources of energy like coal and atomic energy. People have realized the dire effect of using these fuels, and the amount of CO2 being released into the environment. There has been a shift in emphasis towards cleaner ways of generating electricity in recent years. Solar energy is abundantly available and the cleanest renewable energy source available in the world and is ready to use for a variety of applications, such as the generation of electricity for residential, commercial, or industrial consumption and have become very competitive solutions. It can be seen that there is trend of solar photovoltaics (PV), which has seen rapid growth over the years. The increasing trend of adopting PV system allows consumers to be known as producers or “Prosumers”. This report evaluates how solar PV can be used in combination with a battery bank along with three port converter to fulfill the requirement. Power production from PV cannot be consistent due to factors like the weather although The main benefits of solar power are that it can be easily installed cost of generation is low as there is no requirement for fuel and require very little maintenance Distributed maximum power point tracking (MPPT) and autonomous are achieved with the proposed configuration. The input-port of each TPC is connected to an independent PV energy source to achieve individual MPPT, and the output-ports of these TPCs are connected with load. Fully modular design is achieved by using Simulink/matlab

    KAJIAN NUMERIK PERPINDAHAN PANAS PADA KOLEKTOR SURYA DENGAN VARIASI BERBAGAI ABSORBER

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    How to pinpoint energy-inefficient Buildings? An Approach based on the 3D City model of Vienna

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    This paper describes a methodology to assess the energy performance of residential buildings starting from the semantic 3D city model of Vienna. Space heating, domestic hot water and electricity demand are taken into account. The paper deals with aspects related to urban data modelling, with particular attention to the energy-related topics, and with issues related to interactive data exploration/visualisation and management from a plugin-free web-browser, e.g. based on Cesium, a WebGL virtual globe and map engine. While providing references to existing previous works, only some general and introductory information is given about the data collection, harmonisation and integration process necessary to create the CityGML-based 3D city model, which serves as the central information hub for the different applications developed and described more in detail in this paper. The work aims, among the rest, at developing urban decision making and operational optimisation software tools to minimise non-renewable energy use in cities. The results obtained so far, as well as some comments about their quality and limitations, are presented, together with the discussion regarding the next steps and some planned improvements

    Molecular and Genetic Aspects of Odontogenic Lesions

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    In this article we outline the molecular findings of select odontogenic tumors. In each section, we briefly review selected the clinicoradiographic, histologic, immunologic features, focusing on the molecular findings and their applications in practice. The understanding of molecular pathobiology at various other organ sites has developed quite rapidly in recent years, however much remains unknown about the genetic profile of odontogenic tumors. Improved understanding of mutations in odontogenic tumors may clarify classification schema and elucidate targets for novel therapies. Molecular testing will no doubt improve our understanding of odontogenic tumor pathogenesis and will likely be, someday, an important component of routine clinical practice and its role will only increase in the coming years

    Insight into the molecular pathophysiology of myelodysplastic syndromes: targets for novel therapy

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    Myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell disorders characterized by abnormal cellular differentiation and maturation with variable progression to acute leukemia. Over the last decade, scientific discoveries have unraveled specific pathways involved in the complex pathophysiology of MDS. Prominent examples include aberrations in cytokines and their signaling pathways (such as tumor necrosis factor-alpha, interferon-gamma, SMAD proteins), mutations in genes encoding the RNA splicing machinery (SF3B1, SRSF2, ZRSR2, and U2AF1 genes), mutations in genes disrupting the epigenetic machinery (TET2, DNMT3A, DNMT3B, EZH2, ASXL1). In addition, abnormalities in regulatory T-cell dynamics and atypical interactions between the bone marrow microenvironment, stroma and progenitor cells, and abnormal maintenance of telomeres are also notable contributors to the complex pathogenesis of MDS. These pathways represent potential targets for novel therapies. Specific therapies include drugs targeting aberrant DNA methylation and chromatin remodeling, modulating/activating the immune system to enhance tumor-specific cellular immune responses and reduce anomalous cytokine signaling, and blocking abnormal interaction between hematopoietic progenitors and stromal cells

    Limited effectiveness of home drinking water purification efforts in Karachi, Pakistan

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    Objective: In many developing-country urban areas, municipally supplied water is not microbiologically safe. This study evaluated drinking water quality and effect of home water purification efforts in Karachi, Pakistan.Methods: Members of 300 households, including 100 households who used the Aga Khan University Hospital Laboratory and 200 of their neighbors were interviewed. In 293 consenting households, structured observations were performed and drinking water was analyzed for the presence of coliforms, using the multiple tube fermentation technique.Results: Although 193 of the 293 households (66%) reported using some method to purify their drinking water, including 169 (58%) who boiled their water, only 48 (16%) of the drinking water samples were free of coliforms. Although a combination of boiling and filtering was the most effective method of purification, only 38% of samples that had been boiled and filtered were free of coliforms.CONCLUSIONS: Further refinements and evaluations of home-based efforts to purify and store water are needed

    Assessment of functional outcome of operative management of displaced acetabular fractures and complications

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    Background: Aim of the study was to assess the functional outcome of operative management of displaced acetabular fractures and complications.Methods: The study included sixty patients presenting within 2 weeks with displaced fractures of more than 2 mm. Elderly patients with osteoporotic bones and co-morbid conditions were excluded.Results: A total of sixty patients were operated on. Union was achieved in anatomical position in 51 patients (85%) and in malposition in 9 (15%) patients. Excellent results were obtained in 15 (25%) patients, good results in 32 (53%), fair results in 7 (11.6%) and poor results in 6 (10%) patients. Post operative complications included infection in 2 (3%), sciatic nerve injury in 2 (3%) and avascular necrosis (AVN) in 3 (5%) patients.Conclusions: In the present study, majority of the patients were operated within two weeks. The Harris hip score averaged 58

    Mumps myocarditis: a forgotten disease?

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    Mumps is an acute viral illness that follows a self-limiting course but up to 10% of cases have a complicated course with the involvement of other organ systems. Myocarditis is reported as a complication but the incidence has greatly fallen ever since the development of the mumps vaccine. A child presented to our department with parotid swelling and fever. Persistent tachycardia with irregular pulse led to further cardiac work up which showed decreased ejection fraction and raised serum cardiac enzymes, indicating myocardial damage. With ionotropic agents and supportive care, there was complete normalization of ejection fraction and serum cardiac enzyme levels. He was discharged within a week of admission. This case highlights the importance of suspecting myocarditis in the setting of mumps, a diagnosis that precludes early suspicion in mumps patients suffering from cardiac symptoms not explained by other potential aetiologies. Early suspicion and timely supportive care are essential to ensure favourable outcomes
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