806 research outputs found
The synthesis of boron carbide filaments final report
Synthesis, strength, crystal structure, and composite material formation of boron carbide whisker
A genome-wide survey of segmental duplications that mediate common human genetic variation of chromosomal architecture.
Recent studies have identified a small number of genomic rearrangements that occur frequently in the general population. Bioinformatics tools are now available for systematic genome-wide surveys of higher-order structures predisposing to such common variations in genomic architecture. Segmental duplications (SDs) constitute up to 5 per cent of the genome and play an important role in generating additional rearrangements and in disease aetiology. We conducted a genome-wide database search for a form of SD, palindromic segmental duplications (PSDs), which consist of paired, inverted duplications, and which predispose to inversions, duplications and deletions. The survey was complemented by a search for SDs in tandem orientation (TSDs) that can mediate duplications and deletions but not inversions. We found more than 230 distinct loci with higher-order genomic structure that can mediate genomic variation, of these about 180 contained a PSD. A number of these sites were previously identified as harbouring common inversions or as being associated with specific genomic diseases characterised by duplication, deletions or inversions. Most of the regions, however, were previously unidentified; their characterisation should identify further common rearrangements and may indicate localisations for additional genomic disorders. The widespread distribution of complex chromosomal architecture suggests a potentially high degree of plasticity of the human genome and could uncover another level of genetic variation within human populations
Terror, Theory, and the Humanities
The events of September 11, 2001, have had a strong impact on theory and the humanities. They call for a new philosophy, as the old philosophy is inadequate to account for them. They also call for reflection on theory, philosophy, and the humanities in general. While the recent location and killing of Osama bin Laden, the leader of al-Qaeda, in Pakistan on May 2, 2011 - almost ten years after he and his confederates carried out the 9/11 attacks - may have ended the "war on terror", it has not ended the journey to understand what it means to be a theorist in the age of phobos nor the effort to create a new philosophy that measures up with life in the new millennium. It is in the spirit of hope - the hope that theory will help us to understand the age of terror - that the essays in this collection are presented
Study of the growth parameters involved in synthesizing boron carbide filaments
Growth and deposition zone geometry effects on boron carbide whisker production, mechanical properties, and composite application
Trichostatin A Inhibits Corneal Haze \u3cem\u3ein vitro\u3c/em\u3e and \u3cem\u3ein vivo\u3c/em\u3e
PURPOSE. Trichostatin A (TSA), a histone deacetylase inhibitor, has been shown to suppress TGF- âinduced fibrogenesis in many nonocular tissues. The authors evaluated TSA cytotoxicity and its antifibrogenic activity on TGF- âdriven fibrosis in the cornea with the use of in vitro and in vivo models.
METHODS. Human corneal fibroblasts (HSFs) were used for in vitro studies, and New Zealand White rabbits were used for in vivo studies. Haze in the rabbit cornea was produced with photorefractive keratectomy (PRK) using excimer laser. Trypan blue exclusion and MTT assays evaluated TSA cytotoxicity to the cornea. Density of haze in the rabbit eye was graded with slit lamp biomicroscopy. Real-time PCR, immunoblotting, or immunocytochemistry was used to measure -smooth muscle actin (SMA), fibronectin, and collagen type IV mRNA or protein levels. TUNEL assay was used to detect cell death.
RESULTS. TSA concentrations of 250 nM or less were noncytotoxic and did not alter normal HSF morphology or proliferation. TGF- 1 treatment of HSF significantly increased mRNA and protein levels of SMA (9-fold), fibronectin (2.5-fold), and collagen type IV (2-fold). TSA treatment showed 60% to 75% decreases in TGF- 1âinduced SMA and fibronectin mRNA levels and 1.5- to 3.0-fold decreases in protein levels but had no effect on collagen type IV mRNA or protein levels in vitro. Two-minute topical treatment of TSA on rabbit corneas subjected to 9 D PRK significantly decreased corneal haze in vivo.
CONCLUSIONS. TSA inhibits TGF- 1âinduced accumulation of extracellular matrix and myofibroblast formation in the human cornea in vitro and markedly decreases haze in rabbit cornea in vivo
An integrative modular approach to systematically predict gene-phenotype associations
<p>Abstract</p> <p>Background</p> <p>Complex human diseases are often caused by multiple mutations, each of which contributes only a minor effect to the disease phenotype. To study the basis for these complex phenotypes, we developed a network-based approach to identify coexpression modules specifically activated in particular phenotypes. We integrated these modules, protein-protein interaction data, Gene Ontology annotations, and our database of gene-phenotype associations derived from literature to predict novel human gene-phenotype associations. Our systematic predictions provide us with the opportunity to perform a global analysis of human gene pleiotropy and its underlying regulatory mechanisms.</p> <p>Results</p> <p>We applied this method to 338 microarray datasets, covering 178 phenotype classes, and identified 193,145 phenotype-specific coexpression modules. We trained random forest classifiers for each phenotype and predicted a total of 6,558 gene-phenotype associations. We showed that 40.9% genes are pleiotropic, highlighting that pleiotropy is more prevalent than previously expected. We collected 77 ChIP-chip datasets studying 69 transcription factors binding over 16,000 targets under various phenotypic conditions. Utilizing this unique data source, we confirmed that dynamic transcriptional regulation is an important force driving the formation of phenotype specific gene modules.</p> <p>Conclusion</p> <p>We created a genome-wide gene to phenotype mapping that has many potential implications, including providing potential new drug targets and uncovering the basis for human disease phenotypes. Our analysis of these phenotype-specific coexpression modules reveals a high prevalence of gene pleiotropy, and suggests that phenotype-specific transcription factor binding may contribute to phenotypic diversity. All resources from our study are made freely available on our online Phenotype Prediction Database <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>.</p
Polyphenols in Groundnut Genotypes Resistant and Susceptible to Seed Colonization by Aspergillus flavus
Thirteen groundnut genotypes, eight resistant and five susceptible to in vitro seed colonization by Aspergillus flavus were grown in replicated trials at three locations in Andhra Pradesh, India. Seed coats of these genotypes were analyzed for polyphenols using different methods. No significant correlation was observed between seed colonization and polyphenols content, which corroborates earlier observations on many genotypes using a single method for polyphenols estimation
Research on fiber-reinforced composites
Research in materials science - high temperature structural materials, wetting and adherence of nickel alloys to sapphire, boron carbide filaments, and ceramic and graphite fiber
Resistance in groundnut genotypes to Kalahasti malady caused by the stunt nematode, Tylenchorhynchus brevilineatus
A severe nematode disease of groundnut, popularly called 'Kalahasti malady', caused by Tylenchorhynchus brevilineatus, has been prevalent since 1976 in certain parts of Andhra Pradesh, India. A total of 1599 groundnut germplasm accessions and breeding lines were screened for resistance to the nematode disease in replicated trials on a farmer's field in a disease hot spot location during 1985-86. Twenty-three genotypes were identified as resistant and they had disease scores of 2.0 or less on a 1-5 disease scale. Of these, 14 genotypes were confirmed to be resistant in advanced screening trials in the 1986 rainy and the 1985/6 and 1986/7 post-rainy season. Resistance to the nematode was stable in all three trial sites in the 1986/7 post-rainy season. Most of the resistant genotypes have undesirable pod/seed characteristics. One of the resistant genotypes is a high-yielding breeding line (TCG 1518) and this is being released for use in disease-affected areas of Andhra Prades
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