306 research outputs found
Performance Analysis of Congestion Control Techniques ADTCP and Improved ADTCP for Improving TCP Performance over Ad-hoc Networks
Recognizing the event of clog in a mobile ad-hoc network (MANET) is a noteworthy undertaking. The inbuilt clog control systems of existing transmission control protocol (TCP) intended for wired systems don't deal with the interesting properties of shared remote multi-bounce interface. There are a few methodologies proposed for identifying and defeating the clog in the portable specially appointed system. The sender conduct is modified fittingly. The proposed strategy is likewise good with standard TCP
Approaches in biotechnological applications of natural polymers
Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figuresMajor update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figuresThe preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess
Dysphagia as a manifestation of esophageal tuberculosis: a report of two cases
<p>Abstract</p> <p>Introduction</p> <p>Esophageal involvement by <it>Mycobacterium tuberculosis </it>is rare and the diagnosis is frequently made by means of an esophageal biopsy during the evaluation of dysphagia. There are few cases reported in the literature.</p> <p>Case presentation</p> <p>We present two cases of esophageal tuberculosis in 85- and 65-year-old male Caucasian patients with initial complaints of dysphagia and epigastric pain. Upper gastrointestinal endoscopy resulted in the diagnosis of esophageal tuberculosis following the biopsy of lesions of irregular mucosa in one case and a sessile polyp in the other. Pulmonary tuberculosis was detected in one patient. In one patient esophageal stricture developed as a complication. Antituberculous therapy was curative in both patients.</p> <p>Conclusion</p> <p>Although rare, esophageal tuberculosis has to be kept in mind in the differential diagnosis of dysphagia. Pulmonary involvement has important implications for contact screening.</p
RAId_aPS: MS/MS analysis with multiple scoring functions and spectrum-specific statistics
Statistically meaningful comparison/combination of peptide identification
results from various search methods is impeded by the lack of a universal
statistical standard. Providing an E-value calibration protocol, we
demonstrated earlier the feasibility of translating either the score or
heuristic E-value reported by any method into the textbook-defined E-value,
which may serve as the universal statistical standard. This protocol, although
robust, may lose spectrum-specific statistics and might require a new
calibration when changes in experimental setup occur. To mitigate these issues,
we developed a new MS/MS search tool, RAId_aPS, that is able to provide
spectrum-specific E-values for additive scoring functions. Given a selection of
scoring functions out of RAId score, K-score, Hyperscore and XCorr, RAId_aPS
generates the corresponding score histograms of all possible peptides using
dynamic programming. Using these score histograms to assign E-values enables a
calibration-free protocol for accurate significance assignment for each scoring
function. RAId_aPS features four different modes: (i) compute the total number
of possible peptides for a given molecular mass range, (ii) generate the score
histogram given a MS/MS spectrum and a scoring function, (iii) reassign
E-values for a list of candidate peptides given a MS/MS spectrum and the
scoring functions chosen, and (iv) perform database searches using selected
scoring functions. In modes (iii) and (iv), RAId_aPS is also capable of
combining results from different scoring functions using spectrum-specific
statistics. The web link is
http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/raid_aps/index.html. Relevant
binaries for Linux, Windows, and Mac OS X are available from the same page.Comment: 34 pages, 10 figures, 1 supplementary information file
(RAId_aPS_support.pdf). To view the supplementary file, please download and
extract the gzipped tar source file listed under "Other formats
The first case report of dental floss pick-related injury presenting with massive hemoptysis: A case report
<p>Abstract</p> <p>Introduction</p> <p>A tracheobronchial foreign body is a rarely mentioned cause of massive hemoptysis. Although an aspirated toothpick is a well-known cause of traumatic injury to the respiratory tract, a similar device called a dental floss pick, which is much larger than a toothpick, has never been described as a tracheobronchial foreign body.</p> <p>Case presentation</p> <p>We report a case of massive hemoptysis in a 32-year-old man due to a dental floss pick in the left main bronchus. Flexible fiberoptic bronchoscopy was successful in removing the foreign body.</p> <p>Conclusion</p> <p>Tracheobronchial foreign body can be a medical emergency requiring immediate intervention and massive hemoptysis may be the presenting symptom. Flexible fiberoptic bronchoscopy is recommended as the first-line treatment modality for tracheobronchial foreign body removal. A dental floss pick may present as a tracheobronchial foreign body and can reside in the airway asymptomatically for many years.</p
Clinical significance of cardiovascular dysmetabolic syndrome
Although diabetes mellitus is predominantly a metabolic disorder, recent data suggest that it is as much a vascular disorder. Cardiovascular complications are the leading cause of death and disability in patients with diabetes mellitus. A number of recent reports have emphasized that many patients already have atherosclerosis in progression by the time they are diagnosed with clinical evidence of diabetes mellitus. The increased risk of atherosclerosis and cardiovascular complications in diabetic patients is related to the frequently associated dyslipidemia, hypertension, hyperglycemia, hyperinsulinemia, and endothelial dysfunction. The evolving knowledge regarding the variety of metabolic, hormonal, and hemodynamic abnormalities in patients with diabetes mellitus has led to efforts designed for early identification of individuals at risk of subsequent disease. It has been suggested that insulin resistance, the key abnormality in type II diabetes, often precedes clinical features of diabetes by 5–6 years. Careful attention to the criteria described for the cardiovascular dysmetabolic syndrome should help identify those at risk at an early stage. The application of nonpharmacologic as well as newer emerging pharmacologic therapies can have beneficial effects in individuals with cardiovascular dysmetabolic syndrome and/or diabetes mellitus by improving insulin sensitivity and related abnormalities. Early identification and implementation of appropriate therapeutic strategies would be necessary to contain the emerging new epidemic of cardiovascular disease related to diabetes
Organization and molecular evolution of a disease-resistance gene cluster in coffee trees
<p>Abstract</p> <p>Background</p> <p>Most disease-resistance (R) genes in plants encode NBS-LRR proteins and belong to one of the largest and most variable gene families among plant genomes. However, the specific evolutionary routes of NBS-LRR encoding genes remain elusive. Recently in coffee tree (<it>Coffea arabica</it>), a region spanning the <it>S</it><sub><it>H</it></sub><it>3 </it>locus that confers resistance to coffee leaf rust, one of the most serious coffee diseases, was identified and characterized. Using comparative sequence analysis, the purpose of the present study was to gain insight into the genomic organization and evolution of the <it>S</it><sub><it>H</it></sub><it>3 </it>locus.</p> <p>Results</p> <p>Sequence analysis of the <it>S</it><sub><it>H</it></sub><it>3 </it>region in three coffee genomes, E<sup>a </sup>and C<sup>a </sup>subgenomes from the allotetraploid <it>C. arabica </it>and C<sup>c </sup>genome from the diploid <it>C. canephora</it>, revealed the presence of 5, 3 and 4 R genes in E<sup>a</sup>, C<sup>a</sup>, and C<sup>c </sup>genomes, respectively. All these R-gene sequences appeared to be members of a CC-NBS-LRR (CNL) gene family that was only found at the <it>S</it><sub><it>H</it></sub><it>3 </it>locus in <it>C. arabica</it>. Furthermore, while homologs were found in several dicot species, comparative genomic analysis failed to find any CNL R-gene in the orthologous regions of other eudicot species. The orthology relationship among the <it>S</it><sub><it>H</it></sub><it>3</it>-CNL copies in the three analyzed genomes was determined and the duplication/deletion events that shaped the <it>S</it><sub><it>H</it></sub><it>3 </it>locus were traced back. Gene conversion events were detected between paralogs in all three genomes and also between the two sub-genomes of <it>C. arabica</it>. Significant positive selection was detected in the solvent-exposed residues of the <it>S</it><sub><it>H</it></sub><it>3</it>-CNL copies.</p> <p>Conclusion</p> <p>The ancestral <it>S</it><sub><it>H</it></sub><it>3</it>-CNL copy was inserted in the <it>S</it><sub><it>H</it></sub><it>3 </it>locus after the divergence between Solanales and Rubiales lineages. Moreover, the origin of most of the <it>S</it><sub><it>H</it></sub><it>3</it>-CNL copies predates the divergence between <it>Coffea </it>species. The <it>S</it><sub><it>H</it></sub><it>3</it>-CNL family appeared to evolve following the birth-and-death model, since duplications and deletions were inferred in the evolution of the <it>S</it><sub><it>H</it></sub><it>3 </it>locus. Gene conversion between paralog members, inter-subgenome sequence exchanges and positive selection appear to be the major forces acting on the evolution of <it>S</it><sub><it>H</it></sub><it>3</it>-CNL in coffee trees.</p
Azadirachtin biosynthesis induction in Azadirachta indica A. Juss cotyledonary calli with elicitor agents
The use of cell and plant tissues culture techniques to produce economically important active metabolites has been growing. Among these substances, azadirachtin (AZA), produced by the neem tree (Azadirachta indica), has received considerable attention due to its bioinsecticide action. The main goal of this work was to analyze the AZA levels in neem cotyledonary calli. The calli were grown in agitated Woody Plant Medium (WPM) liquid medium, supplemented with glucose (Gl), hydrolyzed casein (HC) and methyl jasmonate (MeJ) as elicitor agent. An interaction was observed between these substances, depending on in vitro cultivation time with orbital agitation. The highest concentrations (average of 0.2470 µg g-1) of AZA were produced in the first and second weeks of culture when the cell mass was grown in a medium with 2% Gl v/v, 500 mg L-1 HC and 100 µM of MeJ. This corresponded to approximately 57% of the AZA content stored in the donor plants seeds, used as a source of explants to induce in vitro callus formation. It was concluded that the nutrition, as well as the concentration of MeJ as signal transduction of secondary metabolism in neem cells, might influence the AZA content produced in vitro
Evidence for a Rad18-Independent Frameshift Mutagenesis Pathway in Human Cell-Free Extracts
Bypass of replication blocks by specialized DNA polymerases is crucial for cell survival but may promote mutagenesis and genome instability. To gain insight into mutagenic sub-pathways that coexist in mammalian cells, we examined N-2-acetylaminofluorene (AAF)-induced frameshift mutagenesis by means of SV40-based shuttle vectors containing a single adduct. We found that in mammalian cells, as previously observed in E. coli, modification of the third guanine of two target sequences, 5'-GGG-3' (3G) and 5'-GGCGCC-3' (NarI site), induces –1 and –2 frameshift mutations, respectively. Using an in vitro assay for translesion synthesis, we investigated the biochemical control of these events. We showed that Pol eta, but neither Pol iota nor Pol zeta, plays a major role in the frameshift bypass of the AAF adduct located in the 3G sequence. By complementing PCNA-depleted extracts with either a wild-type or a non-ubiquitinatable form of PCNA, we found that this Pol eta-mediated pathway requires Rad18 and ubiquitination of PCNA. In contrast, when the AAF adduct is located within the NarI site, TLS is only partially dependent upon Pol eta and Rad18, unravelling the existence of alternative pathways that concurrently bypass this lesion
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