1,885 research outputs found

    La arquitectura actual en Gran Bretaña

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    The Reality of Refuge: How can we adopt a more humane response to a humanitarian crisis?

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    The United Nations High Commissioner for Refugees (UNHCR) estimates that there are over 79.5 million people forcibly displaced globally. Among them are almost 26 million refugees. When 1% of the worlds population has been forced to flee their homes due to conflict or persecution, the issue is undeniably urgent. Unfortunately, these situations are not short term. The United Nations estimates that the average refugee will spend 17 years in a camp. Data from the UNHCR and literature by members of the field are used to gain a comprehensive understanding of the nature of both planned and makeshift refugee camps, why they are temporary and what makes up their physical and social fabric. This knowledge is applied to perform a descriptive and critical analysis of existing refugee shelters and camps designed from both top-down and bottom-up approaches and the consequences of each. By using existing research and documentation observing and analysing how residents appropriate their surroundings to better suit their individual needs, the discrepancy between the actual needs of refugees and the needs which are currently fulfilled by existing responses is exposed. Existing theory is used to assess the capacity of architecture to redefine the refugee crisis through design in order to achieve more socially sustainable, long lasting alternatives. An architectural approach, based on the assumption of permanence, which understands the importance of addressing social, cultural and psychological needs, as well as immediate physical requirements, is the foundation of conceiving of an alternative, humane refugee camp

    Hearts Ablaze: Radio Frequency Ablation as Treatment for Cardiac Arrythmia

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    This project analyzes several of the parameters involved in the use of radiofrequency ablation (RFA) in the treatment of cardiac arrhythmia. Arrhythmia is an irregular beating of the heart that can be caused by improperly timed contractions within the heart, which can, in certain circumstances, be corrected by ablating tissue. One out of every five hundred people is born with an arrhythmia and others acquire the condition through heart disease. For heart attack victims, it is the most common cause of sudden death. RFA is a common way to treat serious arrhythmia cases by cutting the short circuit through the destruction of certain tissues. We used finite element analysis along with prototyping software to determine the duration of treatment, with special attention to the damage caused to surrounding tissue. We found that the optimal parameters for most effective treatment were to administer 30V for 120 seconds ? which happens to be the standard method of operation. This destroys the necessary part of the AV node while maintaining the surrounding tissue at relatively normal temperatures

    Analysis and visualization of chromosomal abnormalities in SNP data with SNPscan

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    BACKGROUND: A variety of diseases are caused by chromosomal abnormalities such as aneuploidies (having an abnormal number of chromosomes), microdeletions, microduplications, and uniparental disomy. High density single nucleotide polymorphism (SNP) microarrays provide information on chromosomal copy number changes, as well as genotype (heterozygosity and homozygosity). SNP array studies generate multiple types of data for each SNP site, some with more than 100,000 SNPs represented on each array. The identification of different classes of anomalies within SNP data has been challenging. RESULTS: We have developed SNPscan, a web-accessible tool to analyze and visualize high density SNP data. It enables researchers (1) to visually and quantitatively assess the quality of user-generated SNP data relative to a benchmark data set derived from a control population, (2) to display SNP intensity and allelic call data in order to detect chromosomal copy number anomalies (duplications and deletions), (3) to display uniparental isodisomy based on loss of heterozygosity (LOH) across genomic regions, (4) to compare paired samples (e.g. tumor and normal), and (5) to generate a file type for viewing SNP data in the University of California, Santa Cruz (UCSC) Human Genome Browser. SNPscan accepts data exported from Affymetrix Copy Number Analysis Tool as its input. We validated SNPscan using data generated from patients with known deletions, duplications, and uniparental disomy. We also inspected previously generated SNP data from 90 apparently normal individuals from the Centre d'Étude du Polymorphisme Humain (CEPH) collection, and identified three cases of uniparental isodisomy, four females having an apparently mosaic X chromosome, two mislabelled SNP data sets, and one microdeletion on chromosome 2 with mosaicism from an apparently normal female. These previously unrecognized abnormalities were all detected using SNPscan. The microdeletion was independently confirmed by fluorescence in situ hybridization, and a region of homozygosity in a UPD case was confirmed by sequencing of genomic DNA. CONCLUSION: SNPscan is useful to identify chromosomal abnormalities based on SNP intensity (such as chromosomal copy number changes) and heterozygosity data (including regions of LOH and some cases of UPD). The program and source code are available at the SNPscan website

    Mouse Dendritic Cells Pulsed with Capsular Polysaccharide Induce Resistance to Lethal Pneumococcal Challenge: Roles of T Cells and B Cells

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    Mice are exceedingly sensitive to intra-peritoneal (IP) challenge with some virulent pneumococci (LD50 = 1 bacterium). To investigate how peripheral contact with bacterial capsular polysaccharide (PS) antigen can induce resistance, we pulsed bone marrow dendritic cells (BMDC) of C57BL/6 mice with type 4 or type 3 PS, injected the BMDC intra-foot pad (IFP) and challenged the mice IP with supra-lethal doses of pneumococci. We examined the responses of T cells and B cells in the draining popliteal lymph node and measured the effects on the bacteria in the peritoneum and blood. We now report that: 1) The PS co-localized with MHC molecules on the BMDC surface; 2) PS-specific T and B cell proliferation and IFNγ secretion was detected in the draining popliteal lymph nodes on day 4; 3) Type-specific resistance to lethal IP challenge was manifested only after day 5; 4) Type-specific IgM and IgG antibodies were detected in the sera of only some of the mice, but B cells were essential for resistance; 5) Control mice vaccinated with a single injection of soluble PS did not develop a response in the draining popliteal lymph node and were not protected; 6) Mice injected with unpulsed BMDC also did not resist challenge: In unprotected mice, pneumococci entered the blood shortly after IP inoculation and multiplied exponentially in both blood and peritoneum killing the mice within 20 hours. Mice vaccinated with PS-pulsed BMDC trapped the bacteria in the peritoneum. The trapped bacteria proliferated exponentially IP, but died suddenly at 18–20 hours. Thus, a single injection of PS antigen associated with intact BMDC is a more effective vaccine than the soluble PS alone. This model system provides a platform for studying novel aspects of PS-targeted vaccination

    Baryon Antibaryon Nonets

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    The baryon-antibaryon SU(3) nonets are proposed as a scheme to classify the increased number of experimentally observed enhancements near the baryon antibaryon mass threshold. The scheme is similar to the Fermi-Yang-Sakata model, which was put forth about fifty years ago in explaining the mesons observed at that time. According to the present scheme, many new baryon-antibaryon bound states are predicted, and their possible productions in quarkonium decays and B decays are suggested for experimental search.Comment: 5 pages, 1 figur

    Three-dimensional quantitative evaluation method of nonrigid registration algorithms for adaptive radiotherapy

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    Purpose: Current radiotherapy is progressing to the concept of adaptive radiotherapy, which implies the adaptation of planning along the treatment course. Nonrigid registration is an essential image processing tool for adaptive radiotherapy and image guided radiotherapy, and the three-dimensional (3D) nature of the current radiotherapy techniques requires a 3D quantification of the registration error that existing evaluation methods do not cover appropriately. The authors present a method for 3D evaluation of nonrigid registration algorithms’ performance, based on organ delineations, capable of working with near-spherical volumes even in the presence of concavities. Methods: The evaluation method is composed by a volume shape description stage, developed using a new ad hoc volume reconstruction algorithm proposed by the authors, and an error quantification stage. The evaluation method is applied to the organ delineations of prostate and seminal vesicles, obtained by an automatic segmentation method over images of prostate cancer patients treated with intensity modulated radiation therapy. Results: The volume reconstruction algorithm proposed has been shown to accurately model complex 3D surfaces by the definition of clusters of control points. The quantification method, inspired by the Haussdorf–Chebysev distance, provides a measure of the largest registration error per control direction, defining a valid metric for concave-convex volumes. Summarizing, the proposed evaluation methodology presents accurate results with a high spatial resolution in a negligible computation time in comparison with the nonrigid registration time. Conclusions: Experimental results show that the metric selected for quantifying the registration error is of utmost importance in a quantitative evaluation based on measuring distances between volumes. The accuracy of the volume reconstruction algorithm is not so relevant as long as the reconstruction is tight enough on the actual volume of the organ. The new evaluation method provides a smooth and accurate volume reconstruction for both the reference and the registered organ, and a complete 3D description of nonrigid registration algorithms’ performance, resulting in a useful tool for study and comparison of registration algorithms for adaptive radiotherapy
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