81 research outputs found
Factors potentially influencing the abundance of mosquitoes in Louisiana rice fields
The rice stink bug (Oebalus pugnax) is the major pest of late-season rice in Louisiana. Prior studies indicate that large populations of mosquitoes are often present in rice fields during the time that rice fields are infested with rice stink bugs. Lambda-cyhalothrin (Karate®) is widely used to control rice stink bugs. The purpose of this study was to determine if application of the insecticide Karate® at a rate of 0.033 kg/ha, for rice stink bug control had an effect on the population of mosquitoes in rice fields. This effect was assessed by monitoring natural populations of mosquitoes before and after applications of Karate® in simulated rice paddies at the LSU AgCenter Rice Research Station (Crowley, Acadia Parish, Louisiana) during the summers of 2003, 2004 and 2005. In 2005, monitoring of native mosquito population was complemented by the use of sentinel cages with Culex quinquefasciatus Say larvae and exposure of Cx. quinquefasciatus larvae to treated rice field water in the laboratory. The number of larvae in Karate® plots decreased after Karate® applications but a significant overall effect was observed only after the first application of 2004 (p=0.034). Mortality of larvae in sentinel cages (p=0.0386) and of larvae exposed to rice field water at 48hrs (p=0.0130) was also observed in some cases. A test conducted in a large rice plot with sentinel cages confirmed the effect of Karate on mosquito larval populations (p=0.0012). An additional effect of foliar Karate residues on adult Cx. quinquefasciatus mosquitoes was observed in the laboratory (2004, 2005). Higher mortality was detected in adults exposed to rice foliage treated with Karate than the untreated control. Another factor that could influence the number of larvae present in rice fields is the oviposition response of mosquitoes to the presence of predatory insects. To test this response, Cx. quinquefasciatus adult mosquitoes were exposed in cages to water conditioned by previous exposure to potential aquatic predators. According to the Oviposition Activity Index (OAI), female mosquitoes preferred to lay eggs in water conditioned water rather than distilled water. The highest OAI was obtained with the Hydrophilidae-conditioned water
Diseño vial de 520 ml de adoquinado en la calle del barrio San Caralampio, Municipio de la Concepción, Masaya
En el Barrio San Caralampio, ubicado en la parte oeste del Municipio de la Concepción, Masaya se realizó levantamientos topográficos, con el fin de realizar diseño vial de construcción de adoquinado de 520 ML
Al concluir los levantamientos de campo y diseños de planos se logró obtener las especificaciones técnicas necesarias para indicar con precisión las dimensiones presentadas por el relieve del terreno, para calcular y ejecutar la nivelación del área.
Se calcula la proyección de la rasante, mediante información obtenida en levantamiento planimétrico, para ejecutar corte y relleno en el proceso de movimiento de tierra.
De acuerdo al cumplimiento de las actividades antes mencionadas se logra la consecución de los objetivos específicos planteados para el diseño de construcción de adoquinado, ancho de vías, cunetas y andenes.
La finalidad de elaborar el presupuesto es para obtener conocimientos fundamentales para señalar análisis de costos directos e indirectos, de las diferentes actividades a realizar considerando costos de materiales, mano de obra y tiempo de ejecución.
Se proyectó y elaboro el cronograma de ejecución de actividades a realizar ajustado a Itinerario técnico, de cuarenta y cinco días, dando inicio el 01 de octubre y finalizando el 14 de noviembre del corriente añ
Simulation-based parameter optimization for fetal brain MRI super-resolution reconstruction
Tuning the regularization hyperparameter in inverse problems has
been a longstanding problem. This is particularly true in the case of fetal
brain magnetic resonance imaging, where an isotropic high-resolution volume is
reconstructed from motion-corrupted low-resolution series of two-dimensional
thick slices. Indeed, the lack of ground truth images makes challenging the
adaptation of to a given setting of interest in a quantitative manner.
In this work, we propose a simulation-based approach to tune for a
given acquisition setting. We focus on the influence of the magnetic field
strength and availability of input low-resolution images on the ill-posedness
of the problem. Our results show that the optimal , chosen as the one
maximizing the similarity with the simulated reference image, significantly
improves the super-resolution reconstruction accuracy compared to the generally
adopted default regularization values, independently of the selected pipeline.
Qualitative validation on clinical data confirms the importance of tuning this
parameter to the targeted clinical image setting.Comment: 11 pages. This work has been submitted to MICCAI 202
Auditoria de recursos humanos para la gestión del talento humano en la empresa Grupo Beltrán de la ciudad de Trujillo - 2019
La presente investigación tiene como objetivo describir cómo la Auditoría de Recursos
Humanos contribuye a la Gestión del Talento Humano en la empresa Grupo Beltrán de la
ciudad de Trujillo – 2019. El tipo de estudio es descriptivo, el diseño de investigación es de
una sola casilla. La población (muestra) estuvo conformada por los 58 colaboradores de la
empresa. La técnica utilizada es la encuesta y su instrumento fue un cuestionario de 20
preguntas abiertas. Se concluye que la auditoría de recursos humanos contribuye a la gestión
del talento humano por cuanto ayuda a mantener el orden de todas las actividades de la
empresa relacionados a esta área. Además, los elementos de auditoria de recursos humanos
son principalmente que la empresa es pequeña (familiar) y los procesos relacionados a ello
se manejan en orden y por último, la gestión del talento humano se realiza con
responsabilidad y orden por parte de la Gerencia de la empresa que en la realidad es hijo de
los dueños.This research aims to describe how the Human Resources Audit contributes to the
Management of Human Talent in the company Grupo Beltrán in the city of Trujillo - 2019.
The type of study is descriptive, the research design is of a single box. The population
(sample) was made up of the 58 employees of the company. The technique used is the survey
and its instrument was a questionnaire of 20 open questions. It is concluded that the audit of
human resources contributes to the management of human talent as it helps to maintain the
order of all the activities of the company related to this area. In addition, the elements of
human resources auditing are mainly that the company is small (family) and the processes
related to it are managed in order and lastly, the management of human talent is carried out
with responsibility and order by the Management of the company that in reality is the son of
the owners.Tesi
Evaluacion economica de una plantacion de cerezas localizada en la VII Region
61 p.A nivel mundial los principales países consumidores de cerezas (Prunus avium L.) son Alemania, Rusia, Austria, Reino Unido y Canadá. En términos de producción Chile ocupa el décimo quinto lugar en el mundo y realiza aproximadamente el 10% de las exportaciones de cerezas del hemisferio sur, las que son comercializadas básicamente en EE.UU. y Canadá. Por lo tanto, dada la relevancia que tiene para Chile la producción de este fruto, el objetivo general de este trabajo fue determinar la rentabilidad económica de una plantación de cerezos localizada en la VII Región. Se estableció un horizonte de evaluación de 16 anos para el proyecto y se consideró como unidad de análisis I ha. Para la valorización de inversiones y costos dentro del horizonte de evaluación, los datos fueron agrupados según las etapas de establecimiento (año 0 del proyecto), formación (anos 1, 2 y 3) y producción (ano 4 hasta el año 16 del proyecto). Los precios a productor fueron estimados indirectamente a través de los precios FOB, obteniéndose un precio real promedio de 2,32 dólares kg"'. Este precio fue sensibilizado utilizando como medida de volatilidad la desviación estándar de la serie de precios reales, considerando esta ultima serie como el logaritmo natural de las diferencias de dichos precios. Para estimar la rentabilidad económica de la plantación se calcularon los siguientes indicadores: Valor Actual Neto (VAN), Valor Anual Equivalente (VAE), Tasa Interna de Retorno (TIR) e Índice de Valor Actual Neto (IVAN). Para medir la eficiencia económica se calculo el Costo Medio Total (CMET), Margen Unitario Ponderado (MU) y la Rentabilidad sobre Capital (RSC). En el análisis de sensibilidad se plantearon diferentes escenarios para las siguientes variables: precio de venta en el mercado externo, tipo de cambio, producción y tasa de descuento. Los indicadores de rentabilidad económica para la situación estándar fueron los siguientes: VAN de 2,76 millones, TIR de 25% e VAN de 161,2 kg-' para luego alcanzar un valor de 852,3 kg-' (ano 8), el cual fue disminuyendo hasta llegar a $834 kg-' (ano 16). Por otra parte, la RSC también alcanzo el mayor valor (65%) durante el ano 8 del proyecto, para bajar hasta un 63% en el ano 16. La principal conclusión sugiere que bajo todos los escenarios planteados el proyecto es rentable desde el punto de vista económico
Assessment of fetal corpus callosum biometry by 3D super-resolution reconstructed T2-weighted magnetic resonance imaging.
To assess the accuracy of corpus callosum (CC) biometry, including sub-segments, using 3D super-resolution fetal brain MRI (SR) compared to 2D or 3D ultrasound (US) and clinical low-resolution T2-weighted MRI (T2WS).
Fetal brain biometry was conducted by two observers on 57 subjects [21-35 weeks of gestational age (GA)], including 11 cases of partial CC agenesis. Measures were performed by a junior observer (obs1) on US, T2WS and SR and by a senior neuroradiologist (obs2) on T2WS and SR. CC biometric regression with GA was established. Statistical analysis assessed agreement within and between modalities and observers.
This study shows robust SR to US concordance across gestation, surpassing T2WS. In obs1, SR aligns with US, except for genu and CC length (CCL), enhancing splenium visibility. In obs2, SR closely corresponds to US, differing in rostrum and CCL. The anterior CC (rostrum and genu) exhibits higher variability. SR's regression aligns better with literature (US) for CCL, splenium and body than T2WS. SR is the method with the least missing values.
SR yields CC biometry akin to US (excluding anterior CC). Thanks to superior 3D visualization and better through plane spatial resolution, SR allows to perform CC biometry more frequently than T2WS
Optimising the Therapeutic Interval for Biologics in Patients with Psoriasis
In our clinical experience, more than half of patients do not present a complete response
to biologic drugs, or drug loses its efficacy over time. Plasma determinations of drug and antidrug
antibodies levels are an objective tool for optimisation in these patients; however, established
therapeutic ranges are not suitable, so the objective of this study was to study these patients and
optimise their healthcare. We have made a retrospective, observational study, using data of plasma
levels of drugs and anti-drugs antibodies of infliximab, adalimumab or Etanercept, we summarise all
data and make a study of sensitivity, specificity, positive and negative predictive value on current
therapeutic ranges. We have found a statistically significant association between subtherapeutic
levels and therapeutic failure in psoriasis treated with infliximab and adalimumab. New ranges
were found with higher sensitivity than the established ones, we propose 2–10 g/mL therapeutic
range for infliximab, 3–11 g/mL for adalimumab, and 1–7 g/mL for etanercept. In conclusion,
levels of drug and anti-drug antibodies are a decisive tool for predicting therapeutic response. The
current therapeutic ranges may have minimum values that are excessively high, owing to which
lowering them significantly increases the sensitivity of the test in all cases, and negative predictive
value in the case of etanercept. Further prospective studies are needed to prove the usefulness of
these new ranges.9 página
An Active Contour-based Atlas Registration Model for Automatic Subthalamic Nucleus Targeting on MRI: Method and Validation
This paper presents a new non parametric atlas registration framework, derived from the optical flow model and the active contour theory, applied to automatic subthalamic nucleus (STN) targeting in deep brain stimulation (DBS) surgery. In a previous work, we demonstrated that the STN position can be predicted based on the position of surrounding visible structures, namely the lateral and third ventricles. A STN targeting process can thus be obtained by registering these structures of interest between a brain atlas and the patient image. Here we aim to improve the results of the state of the art targeting methods and at the same time to reduce the computational time. Our simultaneous segmentation and registration model shows mean STN localization errors statistically similar to the most performing registration algorithms tested so far and to the targeting expert’s variability. Moreover, the computational time of our registration method is much lower, which is a worthwhile improvement from a clinical point of view
Cross Validation of Experts Versus Registration Methods for Target Localization in Deep Brain Stimulation
In the last five years, Deep Brain Stimulation (DBS) has become the most popular and effective surgical technique for the treatment of Parkinsons disease (PD). The Subthalamic Nucleus (STN) is the usual target involved when applying DBS. Unfortunately, the STN is in general not visible in common medical imaging modalities. Therefore, atlas-based segmentation is commonly considered to locate it in the images. In this paper, we propose a scheme that allows both, to perform a comparison between different registration algorithms and to evaluate their ability to locate the STN automatically. Using this scheme we can evaluate the expert variability against the error of the algorithms and we demonstrate that automatic STN location is possible and as accurate as the methods currently used
Preparation of Australian and Spanish nursing students for intimate partner violence
Objective: Throughout the world intimate partner violence (IPV) is a significant issue and it is important that nurses contribute to policy development, as well as to the nursing care of families. Nurses are uniquely positioned to identify, and support women experiencing IPV. For them to contribute to policy development, they need firstly to develop a better understanding of the issue and to their role in addressing it. This study explored and compared perceptions, attitudes and knowledge of IPV of nursing students in Australia and Spain.
Methods: Students from all levels of the nursing programs in both countries participated in focus groups and a follow up survey exploring their understanding of, and attitudes towards IPV. The data from the focus groups was analysed thematically and the quantitative data from the survey statistically.
Results: Spanish nursing students had significantly more positive/comprehensive views about the role nurses have in managing IPV, had a stronger view about the nurses’ role and that they were more prepared. Although the Australian and Spanish participants were not identical, for example, the Australian sample was predominantly female and over the age of 35, these factors do not explain why the difference. The study was only undertaken in one Australian University and one Spanish university so results cannot be generalised to either country.
Conclusions: The findings suggest that there may be much more that could be done to prepare nurses to deal with issues of IPV and to take a lead role in recommending policy changes worldwide
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