413 research outputs found
Cross-talk between signaling pathways leading to defense against pathogens and insects
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
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.
Résumé
Contexte et objectif. Bien que la rĂ©section trans urĂ©trale de la prostate (RTUP) se soit imposĂ©e comme alternative Ă lâadĂ©nomectomie chirurgicale classique Ă ciel ouvert, sa pratique reste exceptionnelle dans quelques contrĂ©es africaines. Lâobjectif 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 dâintĂ©rĂȘts comprenaient les donnĂ©es sociodĂ©mographiques, cliniques, Ă©chographiques les comorbiditĂ©s, les complications et lâattitude thĂ©rapeutique avant lâintervention. 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). Lâhypertension artĂ©rielle (42%) et le diabĂšte sucrĂ© de type 2 (41 %) Ă©taient les comorbiditĂ©s les plus frĂ©quentes. Les complications de lâHBP les plus frĂ©quentes Ă©taient lâinfection urinaire (44 %) et la rĂ©tention urinaire (40%). Avant lâadmission Ă lâhĂŽpital, 60% des patients ont eu recours Ă la mĂ©decine traditionnelle. Conclusion. LâavĂšnement 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 dâĂ©ducation, information et communication de la population sur le dĂ©pistage prĂ©coce de lâHBP est Ă envisager
Developmental axon degeneration requires trpv1-dependent Ca 2+ influx
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; CanadĂĄ. McGill University; CanadĂĄFil: de LĂ©on, AndrĂ©s. University of British Columbia; CanadĂĄ. McGill University; CanadĂĄFil: Unsain, Nicolas. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra. Universidad Nacional de CĂłrdoba. Instituto de InvestigaciĂłn MĂ©dica Mercedes y MartĂn Ferreyra; ArgentinaFil: Gibon, Julien. University of British Columbia; CanadĂĄFil: Barker, Philip A.. University of British Columbia; Canad
Assessing patientsâ needs in the follow-up after treatment for colorectal cancerâa mixed-method study
Purpose: The accessibility of cancer care faces challenges due to the rising prevalence of colorectal cancer (CRC) coupled with a shrinkage of healthcare professionalsâknown 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 patientsâ 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,
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)
Sumario : INVESTIGACIĂN. 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 CIENTĂFICA. 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
The zero-field La and Mn nuclear magnetic resonances were
studied in with different oxygen
stoichiometry . The signal intensity, peak frequency and line
broadening of the 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
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 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
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 () and duration
() of reionization can be constrained assuming a parametrization. We
use an EoR simulation of and 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 and 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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