643 research outputs found

    Managing the U.S.-Mexico Border First Requires Defining It

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    A universally agreed-upon definition of the U.S.-Mexico border region is elusive, to say the least. The area's boundaries vary widely depending on the government entity or academic institution involved. This brief reviews the many officially sanctioned definitions of the region, and explains why a consensus is necessary for effective border management

    Co‐existing monophasic teratoma and uterine adenocarcinoma in a female dog

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    Ovarian teratomas are occasionally reported in dogs; the rarest type is the monophasic teratoma,composed of tissues originating from only one germ layer. Canine endometrial adenocarcinomas are also rare in dogs and mainly affect geriatric females. This report describes case of co-existing ovarian teratoma and uterine adenocarcinoma in a 10-year old nulliparous female Boxer presented with lethargy, anorexia and purulent vaginal discharge. Abdominal ultrasonography evidenced pyometra and a mass in the left ovary. This was composed of a uniform whitish tissue with multiple cystic structures. The histology revealed an atrophy of the ovarian parenchyma, compressed by a proliferation of well-differentiated nervous tissue staining positively to vimentin, S100 and neuronal specific enolase (NSE), and negatively to keratin and inhibin. The left uterine horn, whose diameter was markedly increased, showed foci of endometrial cellular atypia, evident nucleoli and mitoses, at light microscopy. To our best knowledge, this is the first report of a coexisting ovarian monophasic teratoma and endometrial adenocarcinoma, two rare reproductive neoplasia in dogs

    Performance evaluation of several well-known and new scintillators for MeV X-ray imaging

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    International audienceDigital X-ray imaging systems for MeV range photon beams are based on a combination of a scintillator screen and either a camera or an amorphous silicon array. To limit dose rate on electronics and enhance imaging device lifetime, the scintillator screen is mirror-coupled to the camera. Performances of such devices are a compromise between exposure time and spatial resolution. These technical characteristics are especially scintillator dependent. In this paper, we present a performance evaluation of six different scintillators with a 9 MeV Bremsstrahlung X-ray source. The tested scintillators are composed of one micro-structured CsI(Tl) scintillator, two phosphor (GOS) screens and three transparent scintillators. These scintillators present a wide range of density, thickness and conversion efficiency. Each scintillator's performance is assessed based on the combination of light output (ADU number) and modulation transfer function (spatial resolution) obtained. The results are helpful to guide design and engineering of high energy imaging devices adapted to specific requirements

    Intensity-Based Registration of Freehand 3D Ultrasound and CT-scan Images of the Kidney

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    This paper presents a method to register a pre-operative Computed-Tomography (CT) volume to a sparse set of intra-operative Ultra-Sound (US) slices. In the context of percutaneous renal puncture, the aim is to transfer planning information to an intra-operative coordinate system. The spatial position of the US slices is measured by optically localizing a calibrated probe. Assuming the reproducibility of kidney motion during breathing, and no deformation of the organ, the method consists in optimizing a rigid 6 Degree Of Freedom (DOF) transform by evaluating at each step the similarity between the set of US images and the CT volume. The correlation between CT and US images being naturally rather poor, the images have been preprocessed in order to increase their similarity. Among the similarity measures formerly studied in the context of medical image registration, Correlation Ratio (CR) turned out to be one of the most accurate and appropriate, particularly with the chosen non-derivative minimization scheme, namely Powell-Brent's. The resulting matching transforms are compared to a standard rigid surface registration involving segmentation, regarding both accuracy and repeatability. The obtained results are presented and discussed

    Contribution of non-genetic factors to the reproductive performance of mirandesa cows

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    Characterization of reproductive traits in Mirandesa beef cattle is important for breed improvement and conservation, mainly due to its little genetic diversity. Reduced individual and maternal performance is often associated with inbreeding depression, which could be further aggravate the environmental effects. In this study, 7386 herd records for Mirandesa were used to characterize the main reproductive traits, like age at first calving (AFC), pregnancy length (PL), calving interval (CI), yearly calving distribution (CD) and productive lifespan (PLf). The non-genetic effects were tested using non-parametric methods, as the target variables were not normally distributed. The median for AFC in Mirandesa was close to 32 months; AFC was affected by the production system, farm and by the year and season of birth. The mean for PL was 287±8.9 days, being affected by parity and calf gender. The median CI, of 378 days, was only affected by the breeding program, parity, season and year. Calving season was unevenly distributed over the year, showing different patterns after the production system. The mean productive lifespan of Mirandesa was 6.45 years, though 20% of the cows presented a PLf longer than ten years. The main non-genetic effects suggested that farmer´s decision and nutrition may constrain the expression of the reproductive traits in Mirandesa breed. This aspect needs to be addressed when designing any breeding programs which should prioritise for the increase in the number of calves per year along with a careful selection of reproducers to decrease reported inbreeding.The authors wish to thank ACBRM (Associação de Criadores de Bovinos de Raça Mirandesa) for providing access to the Mirandesa cattle Herdbook.info:eu-repo/semantics/publishedVersio

    How a plantar pressure-based, tongue-placed tactile biofeedback modifies postural control mechanisms during quiet standing

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    The purpose of the present study was to determine the effects of a plantar pressure-based, tongue-placed tactile biofeedback on postural control mechanisms during quiet standing. To this aim, sixteen young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP) displacements, recorded using a force platform, were used to compute the horizontal displacements of the vertical projection the centre of gravity (CoGh) and those of the difference between the CoP and the vertical projection of the CoG (CoP-CoGv). Altogether, the present findings suggest that the main way the plantar pressure-based, tongue-placed tactile biofeedback improves postural control during quiet standing is via both a reduction of the correction thresholds and an increased efficiency of the corrective mechanism involving the CoGh displacements

    Dual-energy X-ray absorptiometry and calculated FRAX risk scores may underestimate osteoporotic fracture risk in Vitamin D-deficient veterans with HIV infection

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    Objective: We evaluated the utility of the Fracture Risk Assessment Tool (FRAX) in assessing fracture risk in patients with human immunodeficiency virus (HIV) and vitamin D deficiency. Methods: This was a retrospective study of HIV-infected patients with co-existing vitamin D deficiency at the Atlanta Veterans Affairs Medical Center. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry (DEXA), and the 10-year fracture risk was calculated by the FRAX algorithm. Two independent radiologists reviewed lateral chest radiographs for the presence of subclinical vertebral fractures. Results: We identified 232 patients with HIV and vitamin D deficiency. Overall, 15.5% of patients met diagnostic criteria for osteoporosis on DEXA, and 58% had low BMD (T-score between −1 and −2.5). The median risk of any major osteoporotic and hip fracture by FRAX score was 1.45 and 0.10%, respectively. Subclinical vertebral fractures were detected in 46.6% of patients. Compared to those without fractures, those with fractures had similar prevalence of osteoporosis (15.3% versus 15.7%; P>.999), low BMD (53.2% versus 59.3%; P = .419), and similar FRAX hip scores (0.10% versus 0.10%; P = .412). While the FRAX major score was lower in the nonfracture group versus fracture group (1.30% versus 1.60%; P = .025), this was not clinically significant. Conclusion: We found a high prevalence of subclinical vertebral fractures among vitamin D–deficient HIV patients; however, DEXA and FRAX failed to predict those with fractures. Our results suggest that traditional screening tools for fragility fractures may not be applicable to this high-risk patient population

    Development and Validation of a Critical Thinking Assessment-Scale Short Form.

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    This study presents and validates the psychometric characteristics of a short form of the Critical Thinking Self-assessment Scale (CTSAS). The original CTSAS was composed of six subscales representing the six components of Facione’s conceptualisation of critical thinking. The CTSAS short form kept the same structures and reduced the number of items from 115 in the original version, to 60. The CTSAS short form was tested with a sample of 531 higher education students from five countries (Germany, Greece, Lithuania, Romania, and Portugal) enrolled in different disciplinary fields (Business Informatics, Teacher Education, English as a Foreign Language, Business and Economics, and Veterinary Medicine). The confirmatory analysis was used to test the new instrument reliability, internal consistency, and construct validity. Both the models that hypothesized the six factors to be correlated and to tap into a second-order factor representing the complex concept of critical thinking, had acceptable fit to the data. The instrument showed strong internal consistency (α = 0.969) and strong positive correlations between skills and between the skills and the overall scale (p < 0.05). Despite the unbalanced sex distribution in the population (close to 75% females), the instrument retained its factorial structure invariance across sexes. Therefore, the new instrument shows adequate goodness of fit and retained stability and reliability, and is proposed as a valid and reliable means to evaluate and monitor critical thinking in university students

    The Molecular Basis of Monopolin Recruitment to the Kinetochore

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    The monopolin complex is a multifunctional molecular crosslinker, which in S. pombe binds and organises mitotic kinetochores to prevent aberrant kinetochore-microtubule interactions. In the budding yeast S. cerevisiae, whose kinetochores bind a single microtubule, the monopolin complex crosslinks and mono-orients sister kinetochores in meiosis I, enabling the biorientation and segregation of homologs. Here, we show that both the monopolin complex subunit Csm1 and its binding site on the kinetochore protein Dsn1 are broadly distributed throughout eukaryotes, suggesting a conserved role in kinetochore organisation and function. We find that budding yeast Csm1 binds two conserved motifs in Dsn1, one (termed Box 1) representing the ancestral, widely conserved monopolin binding motif and a second (termed Box 2-3) with a likely role in enforcing specificity of sister kinetochore crosslinking. We find that Box 1 and Box 2-3 bind the same conserved hydrophobic cavity on Csm1, suggesting competition or handoff between these motifs. Using structure-based mutants, we also find that both Box 1 and Box 2-3 are critical for monopolin function in meiosis. We identify two conserved serine residues in Box 2-3 that are phosphorylated in meiosis and whose mutation to aspartate stabilises Csm1-Dsn1 binding, suggesting that regulated phosphorylation of these residues may play a role in sister kinetochore crosslinking specificity. Overall, our results reveal the monopolin complex as a broadly conserved kinetochore organiser in eukaryotes, which budding yeast have co-opted to mediate sister kinetochore crosslinking through the addition of a second, regulatable monopolin binding interface

    Unexpected role for IL-17 in protective immunity against hypervirulent Mycobacterium tuberculosis HN878 infection

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    Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), infects one third of the world's population. Among these infections, clinical isolates belonging to the W-Beijing appear to be emerging, representing about 50% of Mtb isolates in East Asia, and about 13% of all Mtb isolates worldwide. In animal models, infection with W-Beijing strain, Mtb HN878, is considered "hypervirulent" as it results in increased mortality and causes exacerbated immunopathology in infected animals. We had previously shown the Interleukin (IL) -17 pathway is dispensable for primary immunity against infection with the lab adapted Mtb H37Rv strain. However, it is not known whether IL-17 has any role to play in protective immunity against infection with clinical Mtb isolates. We report here that lab adapted Mtb strains, such as H37Rv, or less virulent Mtb clinical isolates, such as Mtb CDC1551, do not require IL-17 for protective immunity against infection while infection with Mtb HN878 requires IL-17 for early protective immunity. Unexpectedly, Mtb HN878 induces robust production of IL-1β through a TLR-2-dependent mechanism, which supports potent IL-17 responses. We also show that the role for IL-17 in mediating protective immunity against Mtb HN878 is through IL-17 Receptor signaling in non-hematopoietic cells, mediating the induction of the chemokine, CXCL-13, which is required for localization of T cells within lung lymphoid follicles. Correct T cell localization within lymphoid follicles in the lung is required for maximal macrophage activation and Mtb control. Since IL-17 has a critical role in vaccine-induced immunity against TB, our results have far reaching implications for the design of vaccines and therapies to prevent and treat emerging Mtb strains. In addition, our data changes the existing paradigm that IL-17 is dispensable for primary immunity against Mtb infection, and instead suggests a differential role for IL-17 in early protective immunity against emerging Mtb strains. © 2014 Gopal et al
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