266 research outputs found

    Background Light in Potential Sites for the ANTARES Undersea Neutrino Telescope

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    The ANTARES collaboration has performed a series of {\em in situ} measurements to study the background light for a planned undersea neutrino telescope. Such background can be caused by 40^{40}K decays or by biological activity. We report on measurements at two sites in the Mediterranean Sea at depths of 2400~m and 2700~m, respectively. Three photomultiplier tubes were used to measure single counting rates and coincidence rates for pairs of tubes at various distances. The background rate is seen to consist of three components: a constant rate due to 40^{40}K decays, a continuum rate that varies on a time scale of several hours simultaneously over distances up to at least 40~m, and random bursts a few seconds long that are only correlated in time over distances of the order of a meter. A trigger requiring coincidences between nearby photomultiplier tubes should reduce the trigger rate for a neutrino telescope to a manageable level with only a small loss in efficiency.Comment: 18 pages, 8 figures, accepted for publication in Astroparticle Physic

    Flare hypercalcemia after letrozole in a patient with liver metastasis from breast cancer: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Tamoxifen may occasionally precipitate serious and potentially life-threatening hypercalcemia. However, to date, this has not been documented with aromatase inhibitors.</p> <p>Case presentation</p> <p>A 65-year-old Japanese woman with liver metastasis from breast cancer was admitted to our hospital with vomiting, anorexia, fatigue, arthralgia, muscle pain and dehydration. She had started a course of letrozole five weeks earlier. Our patient's calcium level was 11.6 mg/dL. She was rehydrated and elcatonin was administered. Our patient's parathyroid hormone and parathyroid hormone-related protein levels were not increased and a bone scintigram revealed no evidence of skeletal metastasis. After our patient's serum calcium level returned to within the normal range, letrozole was restarted at one-half of the previous dose (1.25 mg). There were no episodes of hypercalcemia. However, 84 days after restarting letrozole, our patient again complained of arthralgia and treatment was changed to toremifene. During these periods, repeated ultrasonograms revealed no progression of liver metastasis.</p> <p>Conclusion</p> <p>To the best of our knowledge, this is the first case report of flare hypercalcemia after treatment with letrozole in a patient with metastatic breast cancer.</p

    Hereditary renal adysplasia, pulmonary hypoplasia and Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome: a case report

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    <p>Abstract</p> <p>Background</p> <p>Hereditary renal adysplasia is an autosomal dominant trait with incomplete penetrance and variable expression that is usually associated with malformative combinations (including Müllerian anomalies) affecting different mesodermal organs such as the heart, lung, and urogenital system.</p> <p>Case report</p> <p>A case showing pulmonary hypoplasia, hip dysplasia, hereditary renal adysplasia, and Mayer-Rokitansky-Kuster-Hauser syndrome in adulthood is reported here. The i.v. pyelography showed right renal agenesis with a normal left kidney and ureter. Ultrasound and Magnetic Resonance Imaging also showed right renal agenesis with multicystic embryonary remnants in the right hemipelvis probably corresponding to a dysgenetic kidney. An uretrocystoscopy showed absence of ectopic ureter and of the right hemitrigone. She was scheduled for a diagnostic laparoscopy and creation of a neovagina according to the McIndoe technique with a prosthesis and skin graft. Laparoscopy confirmed the absence of the uterus. On both sides, an elongated, solid, rudimentary uterine horn could be observed. Both ovaries were also elongated, located high in both abdominal flanks and somewhat dysgenetics. A conventional cytogenetic study revealed a normal female karyotype 46, XX at a level of 550 GTG bands. A CGH analysis was performed using a 244K oligoarray CGH detecting 11 copy number variants described as normal variants in the databases. The 17q12 and 22q11.21 microdeletions described in other MRKH patients were not present in this case. Four years after operation her evolution is normal, without symptoms and the neovagina is adequately functional. The geneticists have studied her family history and the pedigree of the family is shown.</p> <p>Conclusions</p> <p>We suggest that primary damage to the mesoderm (paraaxil, intermediate, and lateral) caused by mutations in a yet unidentified gene is responsible for: 1) skeletal dysplasia, 2) inappropriate interactions between the bronchial mesoderm and endodermal lung bud as well as between the blastema metanephric and ureteric bud, and eventually 3) Müllerian anomalies (peritoneal mesothelium) at the same level. These anomalies would be transmitted as an autosomal dominant trait with incomplete penetrance and variable expressivity.</p

    Genetic diversity and structure of Iberian Peninsula cowpeas compared to world-wide cowpea accessions using high density SNP markers

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    Cowpea (Vigna unguiculata L. Walp) is an important legume crop due to its high protein content, adaptation to heat and drought and capacity to fix nitrogen. Europe has a deficit of cowpea production. Knowledge of genetic diversity among cowpea landraces is important for the preservation of local varieties and is the basis to obtain improved varieties. The aims of this study were to explore diversity and the genetic structure of a set of Iberian Peninsula cowpea accessions in comparison to a worldwide collection and to infer possible dispersion routes of cultivated cowpea.This study was supported by EUROLEGUME project. This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 613781. European Investment Funds by FEDER/COMPETE/ POCI – Operational Competitiveness and Internationalization Programme, under Project POCI-01-0145-FEDER-006958 and National Funds by FCT – Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2013. MMA was partially supported by the Feed the Future Innovation Lab for Climate Resilient Cowpea (USAID Cooperative Agreement AID-OAA-A-13-00070), which is directed by TJC. The funding entities had no role in the design of the study, collection, analysis and interpretation of data, or in writing the manuscript.info:eu-repo/semantics/publishedVersio

    Intraspecific Inversions Pose a Challenge for the trnH-psbA Plant DNA Barcode

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    BACKGROUND: The chloroplast trnH-psbA spacer region has been proposed as a prime candidate for use in DNA barcoding of plants because of its high substitution rate. However, frequent inversions associated with palindromic sequences within this region have been found in multiple lineages of Angiosperms and may complicate its use as a barcode, especially if they occur within species. METHODOLOGY/PRINCIPAL FINDINGS: Here, we evaluate the implications of intraspecific inversions in the trnH-psbA region for DNA barcoding efforts. We report polymorphic inversions within six species of Gentianaceae, all narrowly circumscribed morphologically: Gentiana algida, Gentiana fremontii, Gentianopsis crinita, Gentianopsis thermalis, Gentianopsis macrantha and Frasera speciosa. We analyze these sequences together with those from 15 other species of Gentianaceae and show that typical simple methods of sequence alignment can lead to misassignment of conspecifics and incorrect assessment of relationships. CONCLUSIONS/SIGNIFICANCE: Frequent inversions in the trnH-psbA region, if not recognized and aligned appropriately, may lead to large overestimates of the number of substitution events separating closely related lineages and to uniting more distantly related taxa that share the same form of the inversion. Thus, alignment of the trnH-psbA spacer region will need careful attention if it is used as a marker for DNA barcoding

    Versatile Aggressive Mimicry of Cicadas by an Australian Predatory Katydid

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    Background: In aggressive mimicry, a predator or parasite imitates a signal of another species in order to exploit the recipient of the signal. Some of the most remarkable examples of aggressive mimicry involve exploitation of a complex signal-response system by an unrelated predator species. Methodology/Principal Findings: We have found that predatory Chlorobalius leucoviridis katydids (Orthoptera: Tettigoniidae) can attract male cicadas (Hemiptera: Cicadidae) by imitating the species-specific wing-flick replies of sexually receptive female cicadas. This aggressive mimicry is accomplished both acoustically, with tegminal clicks, and visually, with synchronized body jerks. Remarkably, the katydids respond effectively to a variety of complex, species-specific Cicadettini songs, including songs of many cicada species that the predator has never encountered. Conclusions/Significance: We propose that the versatility of aggressive mimicry in C. leucoviridis is accomplished by exploiting general design elements common to the songs of many acoustically signaling insects that use duets in pairformation. Consideration of the mechanism of versatile mimicry in C. leucoviridis may illuminate processes driving the evolution of insect acoustic signals, which play a central role in reproductive isolation of populations and the formation of species

    Universal Plant DNA Barcode Loci May Not Work in Complex Groups: A Case Study with Indian Berberis Species

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    BACKGROUND: The concept of DNA barcoding for species identification has gained considerable momentum in animals because of fairly successful species identification using cytochrome oxidase I (COI). In plants, matK and rbcL have been proposed as standard barcodes. However, barcoding in complex genera is a challenging task. METHODOLOGY AND PRINCIPAL FINDINGS: We investigated the species discriminatory power of four reportedly most promising plant DNA barcoding loci (one from nuclear genome--ITS, and three from plastid genome--trnH-psbA, rbcL and matK) in species of Indian Berberis L. (Berberidaceae) and two other genera, Ficus L. (Moraceae) and Gossypium L. (Malvaceae). Berberis species were delineated using morphological characters. These characters resulted in a well resolved species tree. Applying both nucleotide distance and nucleotide character-based approaches, we found that none of the loci, either singly or in combinations, could discriminate the species of Berberis. ITS resolved all the tested species of Ficus and Gossypium and trnH-psbA resolved 82% of the tested species in Ficus. The highly regarded matK and rbcL could not resolve all the species. Finally, we employed amplified fragment length polymorphism test in species of Berberis to determine their relationships. Using ten primer pair combinations in AFLP, the data demonstrated incomplete species resolution. Further, AFLP analysis showed that there was a tendency of the Berberis accessions to cluster according to their geographic origin rather than species affiliation. CONCLUSIONS/SIGNIFICANCE: We reconfirm the earlier reports that the concept of universal barcode in plants may not work in a number of genera. Our results also suggest that the matK and rbcL, recommended as universal barcode loci for plants, may not work in all the genera of land plants. Morphological, geographical and molecular data analyses of Indian species of Berberis suggest probable reticulate evolution and thus barcode markers may not work in this case

    Benchmarking Ontologies: Bigger or Better?

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    A scientific ontology is a formal representation of knowledge within a domain, typically including central concepts, their properties, and relations. With the rise of computers and high-throughput data collection, ontologies have become essential to data mining and sharing across communities in the biomedical sciences. Powerful approaches exist for testing the internal consistency of an ontology, but not for assessing the fidelity of its domain representation. We introduce a family of metrics that describe the breadth and depth with which an ontology represents its knowledge domain. We then test these metrics using (1) four of the most common medical ontologies with respect to a corpus of medical documents and (2) seven of the most popular English thesauri with respect to three corpora that sample language from medicine, news, and novels. Here we show that our approach captures the quality of ontological representation and guides efforts to narrow the breach between ontology and collective discourse within a domain. Our results also demonstrate key features of medical ontologies, English thesauri, and discourse from different domains. Medical ontologies have a small intersection, as do English thesauri. Moreover, dialects characteristic of distinct domains vary strikingly as many of the same words are used quite differently in medicine, news, and novels. As ontologies are intended to mirror the state of knowledge, our methods to tighten the fit between ontology and domain will increase their relevance for new areas of biomedical science and improve the accuracy and power of inferences computed across them

    Effects of macromolecular crowding on intracellular diffusion from a single particle perspective

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    Compared to biochemical reactions taking place in relatively well-defined aqueous solutions in vitro, the corresponding reactions happening in vivo occur in extremely complex environments containing only 60–70% water by volume, with the remainder consisting of an undefined array of bio-molecules. In a biological setting, such extremely complex and volume-occupied solution environments are termed ‘crowded’. Through a range of intermolecular forces and pseudo-forces, this complex background environment may cause biochemical reactions to behave differently to their in vitro counterparts. In this review, we seek to highlight how the complex background environment of the cell can affect the diffusion of substances within it. Engaging the subject from the perspective of a single particle’s motion, we place the focus of our review on two areas: (1) experimental procedures for conducting single particle tracking experiments within cells along with methods for extracting information from these experiments; (2) theoretical factors affecting the translational diffusion of single molecules within crowded two-dimensional membrane and three-dimensional solution environments. We conclude by discussing a number of recent publications relating to intracellular diffusion in light of the reviewed material

    20-Year Risks of Breast-Cancer Recurrence after Stopping Endocrine Therapy at 5 Years

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    The administration of endocrine therapy for 5 years substantially reduces recurrence rates during and after treatment in women with early-stage, estrogen-receptor (ER)-positive breast cancer. Extending such therapy beyond 5 years offers further protection but has additional side effects. Obtaining data on the absolute risk of subsequent distant recurrence if therapy stops at 5 years could help determine whether to extend treatment
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