1,812 research outputs found

    Using THELI pipeline in order to reduce Abell 226 multi-band optical images

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    In this paper we review THELI (Erben & Schrimer, 2005), an image processing pipeline developed to reduce multi-pointing optical images taken by mosaic CCD cameras. This pipeline works on raw images by removing several instrumental contaminations, implementing photometric calibration and astrometric alignment, and constructing a deep co-added mosaic image complemented by a weight map. We demonstrate the procedure of reducing NGC3923 images from raw data to the final results. We also demonstrate the quality of our data reduction strategy using mag-count and mag-error in mag plots. Emphasis is mainly placed on photometric calibration which is of great interest to us due to our scientific case. Based on the cross-association of the extracted catalogue against a reference catalogue of stellar magnitudes, zero-point calibration is performed. Our data reduction strategy and the method employed for cross-correlating large catalogues is also presented.Comment: 5 pages, 2 figure

    Synthesis of novel azo compounds containing 5(4H)-oxazolone ring as potent tyrosinase inhibitors

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    Six new azo dyes containing of 5(4H)-oxazolone ring were prepared by diazotization of 4-aminohippuric acid and coupling with N,N-dimethylaniline, 1-naphthol and 2-naphthol and condensation with 4-fluoro benzaldehyde or 4-trifluoromethoxy benzaldehyde. The new compounds were fully characterized by spectroscopic techniques. All synthesized compounds exhibited high tyrosinase inhibitory behavior. The results of mushroom tyrosinase inhibition assays indicate that the 4-trifluoromethoxy derivatives have high degrees of inhibition and N,N-dimethylaniline derivatives are better for tyrosinase inhibition than 1-naphthol and 2-naphthol derivatives. All synthesized azo compounds (4a-4f) showed the most potent mushroom tyrosinase inhibition, comparable to that of Kojic acid and l-mimosine, as reference standard inhibitors. © 2013 Elsevier Ltd. All rights reserved

    A class of extremising sphere-valued maps with inherent maximal tori symmetries in SO(n)

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    In this paper we consider an energy functional depending on the norm of the gradient and seek to extremise it over an admissible class of Sobolev maps defined on an annulus and taking values on the unit sphere whilst satisfying suitable boundary conditions. We establish the existence of an infinite family of solutions with certain symmetries to the associated nonlinear Euler-Lagrange system in even dimensions and discuss the stability of such extremisers by way of examining the positivity of the second variation of the energy at these solutions

    Space shuttle electromagnetic environment experiment. Phase A: Definition study

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    A program is discussed which develops a concept for measuring the electromagnetic environment on earth with equipment on board an orbiting space shuttle. Earlier work on spaceborne measuring experiments is reviewed, and emissions to be expected are estimated using, in part, previously gathered data. General relations among system parameters are presented, followed by a proposal on spatial and frequency scanning concepts. The methods proposed include a nadir looking measurement with small lateral scan and a circularly scanned measurement looking tangent to the earth's surface at the horizon. Antenna requirements are given, assuming frequency coverage from 400 MHz to 40 GHz. For the low frequency range, 400-1000 MHz, a processed, thinned array is proposed which will be more fully analyzed in the next phase of the program. Preliminary hardware and data processing requirements are presented

    Alert Correlation through a Multi Components Architecture

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    Alert correlation is a process that analyzes the raw alerts produced by one or more intrusion detection systems, reduces nonrelevant ones, groups together alerts based on similarity and causality relationships between them and finally makes aconcise and meaningful view of occurring or attempted intrusions. Unfortunately, most correlation approaches use just a few components that aim only specific correlation issues and so cause reduction in correlation rate. This paper uses a general correlation model that has already been presented in [9] and is consisted of a comprehensive set of components. Then some changes are applied in the component that is related to multi-step attack scenario to detect them better and so to improve semantic level of alerts. The results of experiments with DARPA 2000 data set obviously show the effectiveness of the proposed approach.DOI:http://dx.doi.org/10.11591/ijece.v3i4.277

    Epidemiology of female reproductive cancers in Iran: Results of the gholestan population-based cancer registry

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    Background: Malignancies of the female reproductive tract are estimated to be the third most common group of cancers in women. Objectives: We here aimed to present their epidemiological features in Golestan provincelocated in Northeast of Iran. Materials and Methods: Data on primary female reproductive cancers diagnosed between 2004-2010 were obtained from Golestan Population-based Cancer Registry (GPCR). CanReg-4 and SPSS software were used for data entry and analysis. Age standardized incidence rates (ASR) (per 100,000 person-years) were calculated using the world standard population. Poisson regression analysis was used to compare incidence rates. P-values of less than 0.05 were considered as significant. Results: A total of 6,064 cancer cases were registered in Golestan females in the GPCR during 2004-2010, of which 652 cases (11%) were female reproductive cancers. Cancers of the ovary (ASR=6.03) and cervix (ASR=4.97) were the most common. We found significant higher rates in females living in cities than in villages. Our results showed a rapid increase in age specific incidence rates of female reproductive cancers at the age of 30 years. Conclusions: We found significant higher rates of female reproductive cancers among residents of cities than villages. Differences in the prevalence of risk factors including reproductive behavior between the two populations may partly explain such diversity. Our results also showed a rapid increase in incidence rates of these cancers in young age females. Further studies are warranted to determine risk factors of female reproductive cancers in our population

    Cash-based interventions to enhance dignity in persistent humanitarian refugee crises: a system dynamics approach

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    Cash-based interventions (CBIs) as one form of aid have recently received substantial interest from humanitarian organizations in persistent humanitarian crises. This article proposes a system dynamics (SD) approach to study the CBIs' impact factors on all aspects of the beneficiaries' dignity in longstanding refugee crises, such as the case of Syrian refugees in Turkey. Reviewing the humanitarian management literature,we first develop a set of holistic causal loops to better understand the building boxes of refugees’ dignity and their interactions. Then, an SD model is proposed and calibrated by field data from humanitarian organizations. The result of CBI amount sensitivity and payment time periods shows that CBIs are significantly more effective in diminishing child labor rates and to improve in health and accommodation service reception by the refugees in short terms, but to be as much effective in longer terms, humanitarian organizations must be more directly contribute to service capacity-building activities that are strategies by the hosting governments and supported by the international bodies, such as EU and UN.Otherwise, long-term or enhanced CBI supports can only lead to accelerated service capacity saturation and thus put extra pressure on already strained services and cause tensions between hosting and refugee communities

    Distribution, abundance and biomass of Polychaeta in the north coast of Gorgan Bay

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    The biomass, distribution and ecological index of Polychaeta in the north coast of Gorgan Bay was assessed during spring to winter 2004. Sampling of benthic organisms was also conducted seasonally. Polychaeta species such as Hypniola annenicova (Ampharetidae) and Streblosplo gynobranchiata (Spionidae) belonging to sessil polychaetes and Nereis diversicolor (Nereidae) belonging to mobile Polychaeta were distinguished. The maximum and minimum biomass was 4489.77±712.13 and 4150~c246.37mg/m^ (2) in summer and winter respectively which showed a uniform distribution in all depths. Results indicated no difference in diversity and evenness index in depths and seasons during the year. The highest prevalence and richness of Polychaeta diversity were observed in summer especially in waters one meter deep
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