413 research outputs found

    Cross-talk between signaling pathways leading to defense against pathogens and insects

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    In nature, plants interact with a wide range of organisms, some of which are harmful (e.g. pathogens, herbivorous insects), while others are beneficial (e.g. growth-promoting rhizobacteria, mycorrhizal fungi, and predatory enemies of herbivores). During the evolutionary arms race between plants and their attackers, primary and secondary immune responses evolved to recognize common or highly specialized features of microbial pathogens (Chisholm et al., 2006), resulting in sophisticated mechanisms of defense

    Résection trans urétrale de la prostate : premiÚre expérience à Bukavu, RD Congo: Transurethral resection of the prostate: pilot experience in Bukavu, DR Congo

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    Context and objective. Despite its large use as alternative to open surgical adenomectomy, transurethral resection of the prostate (TURP) is still poorly performed in many African countries. The purpose of this study was to describe a pilotTURP experience in Bukavu. Methods.This retrospective study included 159 patients (average age: 68 ± 8.5 years) with benign prostatic hypertrophy (BPH), treated at three medical centres in Bukavu between February 2014 andFebruary 2017. Socio-demographic, clinical, and ultrasound data were recorded, and comorbidities and complications reported. Each patient was questionned about treatment received before surgery. Results. The average prostatic volume was 53.2 ± 22 grams. All patients were severelysymptomatic (mean International Prostate Symptoms Score (IPSS) 26.8 ± 5.8) and severely bored (mean quality of life score (QOL) 6.2 ± 0.8).Hypertension (42%) and type 2 diabetes (41%) were the most common comorbidities. The most frequent complications of BPH were urinary tractinfection (44%) and urinary retention (40%). Prior to hospital admission, 60% of patients used traditional medicine. Conclusion.This study has revealed a late reference of patients to the hospital, when the illness is already in advanced stage with complications. There is a need of implementing educational measures targeting early detection and reference of patients with BPH in this area. RĂ©sumĂ© Contexte et objectif. Bien que la rĂ©section trans urĂ©trale de la prostate (RTUP) se soit imposĂ©e comme alternative Ă  l’adĂ©nomectomie chirurgicale classique Ă  ciel ouvert, sa pratique reste exceptionnelle dans quelques contrĂ©es africaines. L’objectif de la prĂ©sente Ă©tude Ă©tait de dĂ©crire la premiĂšre expĂ©rience de la RTUP Ă  Bukavu. MĂ©thodes. La prĂ©sente Ă©tude documentaire a portĂ© sur 159 patients avec hypertrophie bĂ©nigne de la prostate (HBP), opĂ©rĂ©s dans 3 centres mĂ©dicaux de Bukavu entre fĂ©vrier 2014 et fĂ©vrier 2017. Les paramĂštres d’intĂ©rĂȘts comprenaient les donnĂ©es sociodĂ©mographiques, cliniques, Ă©chographiques les comorbiditĂ©s, les complications et l’attitude thĂ©rapeutique avant l’intervention. RĂ©sultats. Leur Ăąge moyen Ă©tait de 68±8,5 ans. Le volume prostatique moyen Ă©tait de 53,2 ± 22 grammes. Tous les patients Ă©taient sĂ©vĂšrement symptomatiques (score international des symptĂŽmes prostatiques (IPSS) moyen de 26,8 ± 5,8) et fortement ennuyĂ©s (score de la qualitĂ© de vie (QOL) moyen de 6,2 ± 0,8). L’hypertension artĂ©rielle (42%) et le diabĂšte sucrĂ© de type 2 (41 %) Ă©taient les comorbiditĂ©s les plus frĂ©quentes. Les complications de l’HBP les plus frĂ©quentes Ă©taient l’infection urinaire (44 %) et la rĂ©tention urinaire (40%). Avant l’admission Ă  l’hĂŽpital, 60% des patients ont eu recours Ă  la mĂ©decine traditionnelle. Conclusion. L’avĂšnement de la RTUP Ă  Bukavu a permis de dĂ©celer que la majoritĂ© des patients avec HBP consultent trĂšs tardivement au stade de sevĂ©ritĂ© symptomatique et des complications. Une campagne d’éducation, information et communication de la population sur le dĂ©pistage prĂ©coce de l’HBP est Ă  envisager

    Developmental axon degeneration requires trpv1-dependent Ca 2+ influx

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    Development of the nervous system relies on a balance between axon and dendrite growth and subsequent pruning and degeneration. The developmental degeneration of dorsal root ganglion (DRG) sensory axons has been well studied in part because it can be readily modeled by removing the trophic support by nerve growth factor (NGF) in vitro. We have recently reported that axonal fragmentation induced by NGF withdrawal is dependent on Ca2+, and here, we address the mechanism of Ca2+ entry required for developmental axon degeneration of mouse embryonic DRG neurons. Our results show that the transient receptor potential vanilloid family member 1 (TRPV1) cation channel plays a critical role mediating Ca2+ influx in DRG axons withdrawn from NGF. We further demonstrate that TRPV1 activation is dependent on reactive oxygen species (ROS) generation that is driven through protein kinase C (PKC) and NADPH oxidase (NOX)-dependent pathways that become active upon NGF withdrawal. These findings demonstrate novel mechanistic links between NGF deprivation, PKC activation, ROS generation, and TRPV1-dependent Ca2+ influx in sensory axon degeneration.Fil: Johnstone, Aaron D.. University of British Columbia; Canadå. McGill University; CanadåFil: de Léon, Andrés. University of British Columbia; Canadå. McGill University; CanadåFil: Unsain, Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Gibon, Julien. University of British Columbia; CanadåFil: Barker, Philip A.. University of British Columbia; Canad

    Assessing patients’ needs in the follow-up after treatment for colorectal cancer—a mixed-method study

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    Purpose: The accessibility of cancer care faces challenges due to the rising prevalence of colorectal cancer (CRC) coupled with a shrinkage of healthcare professionals—known as the double aging phenomenon. To ensure sustainable and patient-centred care, innovative solutions are needed. This study aims to assess the needs of CRC patients regarding their follow-up care. Methods: This study uses a mixed-method approach divided in three phases. The initial phase involved focus group sessions, followed by semi-structured interviews to identify patients’ needs during follow-up. Open analysis was done to define main themes and needs for patients. In the subsequent quantitative phase, a CRC follow-up needs questionnaire was distributed to patients in the follow-up. Results: After two focus groups (n = 14) and interviews (n = 5), this study identified six main themes. Findings underscore the importance of providing assistance in managing both physical and mental challenges associated with cancer. Participants emphasised the need of a designated contact person and an increased focus on addressing psychological distress. Furthermore, patients desire individualised feedback on quality of life questionnaires, and obtaining tailored information. The subsequent questionnaire (n = 96) revealed the priority of different needs, with the highest priority being the need for simplified radiology results. A possible approach to address a part of the diverse needs could be the implementation of a platform; nearly 70% of patients expressed interest in the proposed platform. Conclusions: CRC patients perceive substantial room for improvement of their follow-up care. Findings can help to develop a platform fulfilling the distinct demands of CRC patients during follow-up.</p

    DenseLens -- Using DenseNet ensembles and information criteria for finding and rank-ordering strong gravitational lenses,

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    Convolutional neural networks (CNNs) are the state-of-the-art technique for identifying strong gravitational lenses. Although they are highly successful in recovering genuine lens systems with a high true-positive rate, the unbalanced nature of the data set (lens systems are rare), still leads to a high false positive rate. For these techniques to be successful in upcoming surveys (e.g. with Euclid) most emphasis should be set on reducing false positives, rather than on reducing false negatives. In this paper, we introduce densely connected neural networks (DenseNets) as the CNN architecture in a new pipeline-ensemble model containing an ensemble of classification CNNs and regression CNNs to classify and rank-order lenses, respectively. We show that DenseNets achieve comparable true positive rates but considerably lower false positive rates (when compared to residual networks; ResNets). Thus, we recommend DenseNets for future missions involving large data sets, such as Euclid, where low false positive rates play a key role in the automated follow-up and analysis of large numbers of strong gravitational lens candidates when human vetting is no longer feasibl

    IAA : InformaciĂłn y actualidad astronĂłmica (15)

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    Sumario : INVESTIGACIÓN. Aerosoles atmosfĂ©ricos: sus efectos en el clima de las atmĂłsferas del sistema solar.-- El gas molecular en las galaxias.-- VENTANA ABIERTA. Todo un privilegio.-- CHARLAS CON...Vicent MartĂ­nez.-- ACTUALIDAD CIENTÍFICA. Un sistema planetario joven en torno a Beta Pictores.-- Una nueva visita a Canis Major .-- ACTIVIDADES IAA.-- AGENDA.Esta revista se publica con la ayuda de la Accion Especial DIF 2001-4284-E del Programa Nacional de DifusiĂłn de la Ciencia y la TecnologĂ­a, del Ministerio de Ciencia y TecnologĂ­a.N

    Percolative phase separation induced by nonuniformly distributed excess oxygens

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    The zero-field 139^{139}La and 55^{55}Mn nuclear magnetic resonances were studied in La0.8Ca0.2MnO3+ÎŽ\rm La_{0.8}Ca_{0.2}MnO_{3+\delta} with different oxygen stoichiometry ÎŽ\delta. The signal intensity, peak frequency and line broadening of the 139^{139}La NMR spectrum show that excess oxygens have a tendency to concentrate and establish local ferromagnetic ordering around themselves. These connect the previously existed ferromagnetic clusters embedded in the antiferromagnetic host, resulting in percolative conduction paths. This phase separation is not a charge segregation type, but a electroneutral type. The magnetoresistance peak at the temperature where percolative paths start to form provides a direct evidence that phase separation is one source of colossal magnetoresistance effect.Comment: 4 pages, 5 figure

    Realistic Simulations of the Galactic Polarized Foreground: Consequences for 21-cm Reionization Detection Experiments

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    Experiments designed to measure the redshifted 21~cm line from the Epoch of Reionization (EoR) are challenged by strong astrophysical foreground contamination, ionospheric distortions, complex instrumental response and other different types of noise (e.g. radio frequency interference). The astrophysical foregrounds are dominated by diffuse synchrotron emission from our Galaxy. Here we present a simulation of the Galactic emission used as a foreground module for the LOFAR- EoR key science project end-to-end simulations. The simulation produces total and polarized intensity over 10∘×10∘10^\circ \times 10^\circ maps of the Galactic synchrotron and free-free emission, including all observed characteristics of the emission: spatial fluctuations of amplitude and spectral index of the synchrotron emission, together with Faraday rotation effects. The importance of these simulations arise from the fact that the Galactic polarized emission could behave in a manner similar to the EoR signal along the frequency direction. As a consequence, an improper instrumental calibration will give rise to leakages of the polarized to the total signal and mask the desired EoR signal. In this paper we address this for the first time through realistic simulations.Comment: 14 pages, 8 figures, published in MNRA

    Constraining the epoch of reionization with the variance statistic: simulations of the LOFAR case

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    Several experiments are underway to detect the cosmic redshifted 21-cm signal from neutral hydrogen from the Epoch of Reionization (EoR). Due to their very low signal-to-noise ratio, these observations aim for a statistical detection of the signal by measuring its power spectrum. We investigate the extraction of the variance of the signal as a first step towards detecting and constraining the global history of the EoR. Signal variance is the integral of the signal's power spectrum, and it is expected to be measured with a high significance. We demonstrate this through results from a simulation and parameter estimation pipeline developed for the Low Frequency Array (LOFAR)-EoR experiment. We show that LOFAR should be able to detect the EoR in 600 hours of integration using the variance statistic. Additionally, the redshift (zrz_r) and duration (Δz\Delta z) of reionization can be constrained assuming a parametrization. We use an EoR simulation of zr=7.68z_r = 7.68 and Δz=0.43\Delta z = 0.43 to test the pipeline. We are able to detect the simulated signal with a significance of 4 standard deviations and extract the EoR parameters as zr=7.72−0.18+0.37z_r = 7.72^{+0.37}_{-0.18} and Δz=0.53−0.23+0.12\Delta z = 0.53^{+0.12}_{-0.23} in 600 hours, assuming that systematic errors can be adequately controlled. We further show that the significance of detection and constraints on EoR parameters can be improved by measuring the cross-variance of the signal by cross-correlating consecutive redshift bins.Comment: 13 pages, 14 figures, Accepted for publication in MNRA
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