213 research outputs found
Propagation of Rayleighs waves in cracked media
Este trabajo está enfocado a la obtención de resultados numéricos que permitan la detección y caracterización de grietas sub-superficiales en sólidos mediante la incidencia de ondas elásticas de Rayleigh. Los resultados se obtienen a partir de ecuaciones integrales de frontera, que pertenecen al campo de la elastodinámica. Una vez que se aplican las condiciones de frontera se obtiene un sistema de ecuaciones integrales del tipo Fredholm de segunda especie y orden cero, el cual es resuelto mediante eliminación gaussiana. El método que se emplea para la discretización de dichas ecuaciones es conocido como «método indirecto de elementos frontera», el cual puede ser visto como una derivación del teorema clásico de Somigliana. A partir de los análisis realizados en el dominio de la frecuencia emergen picos de resonancia que permiten inferir la presencia de grietas mediante los cocientes espectrales. Se analizaron varios modelos de medios agrietados donde se pretende evidenciar la gran utilidad que presenta el uso de los cocientes espectrales para identificar grietas. Se estudiaron los efectos de la orientación y la localización de las grietas. Los resultados obtenidos presentan buena concordancia con los publicados previamente.This work is focused on the finding of numerical results for detection and characterization of sub-surface cracks in solids under the incidence of Rayleighs elastic waves. The results are obtained from boundary integral equations, which belong to the field of dynamics of elasticity. Once applied the boundary conditions, a system of Fredholms integral equations of second kind and zero order is obtained, which is solved using Gaussian elimination. The method that is used for the solution of such integral equations is known as the Indirect Boundary Element Method, which can be seen as a derivation of the Somiglianas classic theorem. On the basis of the analysis made in the frequency domain, resonance peaks emerge and allow us to infer the presence of cracks through the spectral ratios. Several models of cracked media were analyzed, where analyses reveal the great utility that displays the use of spectral ratios to identify cracks. We studied the effects of orientation and location of cracks. The results show good agreement with the previously published.Peer Reviewe
A report on the nonlinear squeezed states and their non-classical properties of a generalized isotonic oscillator
We construct nonlinear squeezed states of a generalized isotonic oscillator
potential. We demonstrate the non-existence of dual counterpart of nonlinear
squeezed states in this system. We investigate statistical properties exhibited
by the squeezed states, in particular Mandel's parameter, second-order
correlation function, photon number distributions and parameter in
detail. We also examine the quadrature and amplitude-squared squeezing effects.
Finally, we derive expression for the -parameterized quasi-probability
distribution function of these states. All these information about the system
are new to the literature.Comment: Accepted for publication in J. Phys. A: Math. Theo
Incidencia de bajas dosis de N, P Y S sobre el rendimiento de cebolla Valenciana (Variedad sintética 14)
During the growing season of 1988/89 a trial was held in the large vegetable experimental field at the Agronomy Faculty of the University of La Pampa, under square latin design 5 x 5. Fertilizers of N, P and S were applied to the Synthetical Variety 14 of Valenciana onion. The main objective was to determine the influence of N and its interaction of P and S upon final yield. The fertilizars were: Urea; H(NH4)2 PO4 + Urea; (NH4)2 SO4 +Urea; (NH4)2 SO4 +H(NH4)2 PO4 +Urea and tester. All doses were adjust in such manner all plots had the same amount on N, in order to compare its effects. Highly significantive differences were observed between treatments. With respect to entire plant's weight expose to the air, T2 overcame significantly to Tc and T1. Calcium, Magnesium, phosphorus, crude protein and water contens were analyzed in lab and the results are considered normal. According to the results obtained in the current trial, it might be suggested to fertilize onion with compounds including N and Pinto their composition.En el ciclo 1988/89 se realizó en la Huerta Experimental de la Fac. de Agron. de la UNLPam, un ensayo en cuadrado latino 5 x 5, de aplicaci6n de fertilizantes con N, P Y S, en cultivo de "cebollas" variedad sintética 14. El objetivo fue constatar la incidencia del N y su interacción con el P y S sobre el rendimiento del cultivo. Los fertilizantes empleados fueron: Urea; H (NH4)2 PO4 +Urea; (NH4) 2 SO4 +Urea; (NH4) SO4 +H(NH4)2 PO4 +Urea y testigo. En todos los casos las dosis se ajustaron de tal manera que, todas las parcelas en que se aplicaron fertilizantes, vieran la misma cantidad de N para poder comparar sus efectos. En cuanto a los rendimientos de los tratamientos si se observaron diferencias significativas". Respecto al peso planta entera oreada, T2 superó significativamente a TO y T1. También se analizó en laboratorio al contenido de calcio, magnesio, fósforo, proteÃna cruda y agua siendo sus valores normales. Sobre la base de los resultados obtenidos en el presente ensayo se aconsejarÃa fertilizar la cebolla con compuestos que tengan N y P en su composición
Spiked oscillators: exact solution
A procedure to obtain the eigenenergies and eigenfunctions of a quantum
spiked oscillator is presented. The originality of the method lies in an
adequate use of asymptotic expansions of Wronskians of algebraic solutions of
the Schroedinger equation. The procedure is applied to three familiar examples
of spiked oscillators
Local amplification of deep mining induced vibrations - Part.2: Simulation of the ground motion in a coal basin
This work investigates the impact of deep coal mining induced vibrations on
surface constructions using numerical tools. An experimental study of the
geological site amplification and of its influence on mining induced vibrations
has already been published in a previous paper (Part 1: Experimental evidence
for site effects in a coal basin). Measurements have shown the existence of an
amplification area in the southern part of the basin where drilling data have
shown the presence of particularly fractured and soft stratigraphic units. The
present study, using the Boundary Element Method (BEM) in the frequency domain,
first investigates canonical geological structures in order to get general
results for various sites. The amplification level at the surface is given as a
function of the shape of the basin and of the velocity contrast with the
bedrock. Next, the particular coal basin previously studied experimentally
(Driad-Lebeau et al., 2009) is modeled numerically by BEM. The amplification
phenomena characterized numerically for the induced vibrations are found to be
compatible with the experimental findings: amplification level, frequency
range, location. Finally, the whole work was necessary to fully assess the
propagation and amplification of mine induced vibrations. The numerical results
quantifying amplification can also be used to study other coal basins or
various types of alluvial sites
Implementation of a multidisciplinary psychoeducational intervention for Parkinson's disease patients and carers in the community: study protocol
Background: Parkinson’s disease progressively limits patients at different levels and as a result family members play
a key role in their care. However, studies show lack of an integrative approach in Primary Care to respond to the
difficulties and psychosocial changes experienced by them. The aim of this study is to evaluate the effects of a
multidisciplinary psychoeducational intervention focusing on improving coping skills, the psychosocial adjustment
to Parkinson’s disease and the quality of life in patients and family carers in a Primary Care setting.
Methods: This quasi-experimental study with control group and mixed methods was designed to evaluate a
multidisciplinary psychoeducational intervention. Based on the study power calculations, 100 people with
Parkinson’s disease and 100 family carers will be recruited and assigned to two groups. The intervention group will
receive the ReNACE psychoeducational intervention. The control group will be given a general educational
programme. The study will be carried out in six community-based health centres. The results obtained from the
two groups will be collected for evaluation at three time points: at baseline, immediately after the intervention and
at 6 months post-intervention. The results will be measured with these instruments: the Quality of Life Scale PDQ39 for patients and the Scale of Quality of Life of Care-givers SQLC for family carers, and for all participants the
Psychosocial Adjustment to Illness scale and the Brief COPE Inventory. Focus groups will be organised with some
patients and family carers who will have received the ReNACE psychoeducational intervention and also with the
healthcare professionals involved in its development.
Discussion: An important gap exists in the knowledge and application of interventions with a psychosocial
approach for people with PD and family carers as a whole. This study will promote this comprehensive approach in
Primary Care, which will clearly contribute in the existing knowledge and could reduce the burden of PD for
patients and family carers, and also in other long-term conditions
Fungal Virulence and Development Is Regulated by Alternative Pre-mRNA 3′End Processing in Magnaporthe oryzae
RNA-binding proteins play a central role in post-transcriptional mechanisms that control gene expression. Identification of novel RNA-binding proteins in fungi is essential to unravel post-transcriptional networks and cellular processes that confer identity to the fungal kingdom. Here, we carried out the functional characterisation of the filamentous fungus-specific RNA-binding protein RBP35 required for full virulence and development in the rice blast fungus. RBP35 contains an N-terminal RNA recognition motif (RRM) and six Arg-Gly-Gly tripeptide repeats. Immunoblots identified two RBP35 protein isoforms that show a steady-state nuclear localisation and bind RNA in vitro. RBP35 coimmunoprecipitates in vivo with Cleavage Factor I (CFI) 25 kDa, a highly conserved protein involved in polyA site recognition and cleavage of pre-mRNAs. Several targets of RBP35 have been identified using transcriptomics including 14-3-3 pre-mRNA, an important integrator of environmental signals. In Magnaporthe oryzae, RBP35 is not essential for viability but regulates the length of 3′UTRs of transcripts with developmental and virulence-associated functions. The Δrbp35 mutant is affected in the TOR (target of rapamycin) signaling pathway showing significant changes in nitrogen metabolism and protein secretion. The lack of clear RBP35 orthologues in yeast, plants and animals indicates that RBP35 is a novel auxiliary protein of the polyadenylation machinery of filamentous fungi. Our data demonstrate that RBP35 is the fungal equivalent of metazoan CFI 68 kDa and suggest the existence of 3′end processing mechanisms exclusive to the fungal kingdom
SAMHD1-Deficient CD14+ Cells from Individuals with Aicardi-Goutières Syndrome Are Highly Susceptible to HIV-1 Infection
Myeloid blood cells are largely resistant to infection with human immunodeficiency virus type 1 (HIV-1). Recently, it was reported that Vpx from HIV-2/SIVsm facilitates infection of these cells by counteracting the host restriction factor SAMHD1. Here, we independently confirmed that Vpx interacts with SAMHD1 and targets it for ubiquitin-mediated degradation. We found that Vpx-mediated SAMHD1 degradation rendered primary monocytes highly susceptible to HIV-1 infection; Vpx with a T17A mutation, defective for SAMHD1 binding and degradation, did not show this activity. Several single nucleotide polymorphisms in the SAMHD1 gene have been associated with Aicardi-Goutières syndrome (AGS), a very rare and severe autoimmune disease. Primary peripheral blood mononuclear cells (PBMC) from AGS patients homozygous for a nonsense mutation in SAMHD1 (R164X) lacked endogenous SAMHD1 expression and support HIV-1 replication in the absence of exogenous activation. Our results indicate that within PBMC from AGS patients, CD14+ cells were the subpopulation susceptible to HIV-1 infection, whereas cells from healthy donors did not support infection. The monocytic lineage of the infected SAMHD1 -/- cells, in conjunction with mostly undetectable levels of cytokines, chemokines and type I interferon measured prior to infection, indicate that aberrant cellular activation is not the cause for the observed phenotype. Taken together, we propose that SAMHD1 protects primary CD14+ monocytes from HIV-1 infection confirming SAMHD1 as a potent lentiviral restriction factor
Evasion by Stealth: Inefficient Immune Activation Underlies Poor T Cell Response and Severe Disease in SARS-CoV-Infected Mice
Severe Acute Respiratory Syndrome caused substantial morbidity and mortality during the 2002–2003 epidemic. Many of the features of the human disease are duplicated in BALB/c mice infected with a mouse-adapted version of the virus (MA15), which develop respiratory disease with high morbidity and mortality. Here, we show that severe disease is correlated with slow kinetics of virus clearance and delayed activation and transit of respiratory dendritic cells (rDC) to the draining lymph nodes (DLN) with a consequent deficient virus-specific T cell response. All of these defects are corrected when mice are treated with liposomes containing clodronate, which deplete alveolar macrophages (AM). Inhibitory AMs are believed to prevent the development of immune responses to environmental antigens and allergic responses by interacting with lung dendritic cells and T cells. The inhibitory effects of AM can also be nullified if mice or AMs are pretreated with poly I:C, which directly activate AMs and rDCs through toll-like receptors 3 (TLR3). Further, adoptive transfer of activated but not resting bone marrow–derived dendritic cells (BMDC) protect mice from lethal MA15 infection. These results may be relevant for SARS in humans, which is also characterized by prolonged virus persistence and delayed development of a SARS-CoV-specific immune response in individuals with severe disease
Maternal Obesity, Overweight and Gestational Diabetes Affect the Offspring Neurodevelopment at 6 and 18 Months of Age – A Follow Up from the PREOBE Cohort
The study was registered at www.ClinicalTrials.gov, identifier:NCT01634464).Background:
Brain development in fetal life and early infancy is critical to determine lifelong performance in various neuropsychological domains. Metabolic pathologies such as overweight, obesity, and gestational diabetes in pregnant women are prevalent and increasing risk factors that may adversely affect long-term brain development in their offspring.Objective:
The objective of this research was to investigate the influence of maternal metabolic pathologies on the neurodevelopment of the offspring at 6 and 18 months of life.Design:
This was a prospective case-control study of 331 mother- and child pairs from Granada, Spain. The mothers were included during pregnancy into four groups according to their pre-gestational body mass index and their gestational diabetes status; overweight (n:56), obese (n:64), gestational diabetic (n:79), and healthy normal weight controls (n:132). At 6 months and 18 months we assessed the children with the Bayley III scales of neurodevelopment.Results:
At 6 months (n=215), we found significant group differences in cognition composite language, and expressive language. Post hoc test revealed unexpectedly higher scores in the obese group compared to the normal weight group and a similar trend in overweight and diabetic group. The effects on language remained significant after adjusting for confounders with an adjusted odds ratio for a value above median in composite language score of 3.3 (95% CI: 1.1, 10.0; p=0.035) for children of obese mothers. At 18 month (n=197), the offspring born to obese mothers had lost five points in language composite scores and the previous differences in language and cognition was replaced by a suggestive trend of lower gross motor scores in the overweight, obese, and diabetic groups.Conclusions:
Infants of obese mothers had a temporary accelerated development of cognition and language, followed by a rapid deceleration until 18 months of age, particularly of language scores. This novel observation prompts further confirmative studies to explore possible placental and neurodevelopmental mechanisms involved.This study was funded by Spanish Ministry of Innovation and Science. Junta de AndalucÃa: Excellence Projects (P06-CTS-02341); Spanish Ministry of Education (Grant no. SB2010-0025); Spanish Ministry of Economy and Competitiveness (BFU2012-40254-C03-01); Further support was received by Abbott Laboratories, Granada, Spain
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