7,566 research outputs found
Utilizacion de grasas de origen vegetal en raciones de vacas lecheras: rendimentos productivos, reproductivos y composición de la grasa
El objetivo del presente trabajo fue estudiar los efectos de la incorporación de aceites vegetales con distinto grado de saturación en raciones de vacas lecheras, sobre la producción, composición de la leche y de la grasa, y sobre los rendimientos reproductivos. Las raciones experimentales fueron: CONTROL (sin grasa añadida, TC), SOJA (con un 4% de aceite de soja en el concentrado, TS) y LINAZA (con un 4% de aceite de linaza en el concentrado, TL). La incorporación de aceite no afectó la producción de leche, pero redujo el contenido en grasa y proteína. Las raciones con aceite de SOJA y LINAZA presentaron un mayor contenido en ácido Vaccénico y CLA; y una mejor relación poli insaturados/saturados y n6/n3 que las raciones control. Las raciones con aceite de LINAZA dieron lugar a una mayor producción de leche al pico y tardaron menos días en alcanzar el pico de producción que las dietas CONTROL y SOJA. En general, la incorporación de aceite en las raciones dio lugar a una mejora significativa en los índices reproductivos
A New Combination Method Based on Adaptive Genetic Algorithm for Medical Image Retrieval
Medical image retrieval could be based on the text describing the image as the caption or the title. The use of text terms to retrieve images have several disadvantages such as term-disambiguation. Recent studies prove that representing text into semantic units (concepts) can improve the semantic representation of textual information. However, the use of conceptual representation has other problems as the miss or erroneous semantic relation between two concepts. Other studies show that combining textual and conceptual text representations leads to better accuracy. Popularly, a score for textual representation and a score for conceptual representation are computed and then a combination function is used to have one score. Although the existing of many combination methods of two scores, we propose in this paper a new combination method based on adaptive version of the genetic algorithm. Experiments are carried out on Medical Information Retrieval Task of the ImageCLEF 2009 and 2010. The results confirm that the combination of both textual and conceptual scores allows best accuracy. In addition, our approach outperforms the other combination methods
Numerical simulations of stellar SiO maser variability. Investigation of the effect of shocks
A stellar hydrodynamic pulsation model has been combined with a SiO maser
model in an attempt to calculate the temporal variability of SiO maser emission
in the circumstellar envelope (CE) of a model AGB star. This study investigates
whether the variations in local physical conditions brought about by shocks are
the predominant contributing factor to SiO maser variability because, in this
work, the radiative part of the pump is constant. We find that some aspects of
the variability are not consistent with a pump provided by shock-enhanced
collisions alone. In these simulations, gas parcels of relatively enhanced SiO
abundance are distributed in a model CE by a Monte Carlo method, at a single
epoch of the stellar cycle. From this epoch on, Lagrangian motions of
individual parcels are calculated according to the velocity fields encountered
in the model CE during the stellar pulsation cycle. The potentially masing gas
parcels therefore experience different densities and temperatures, and have
varying line-of-sight velocity gradients throughout the stellar cycle, which
may or may not be suitable to produce maser emission. At each epoch (separated
by 16.6 days), emission lines from the parcels are combined to produce
synthetic spectra and VLBI-type images. We report here the results for v=1,
J=1-0 (43-GHz) and J=2-1 (86-GHz) masers.Comment: 16 pages, 8 figures, accepted by A&
Employment Expectations and Gross Flows by Type of Work Contract
There is growing interest in understanding firms’ temporary and permanent employment practices and how institutional changes shape them. Using data on Spanish establishments, we examine: (a) how employers adjust temporary and permanent job and worker flows to prior employment expectations, and (b) how the 1994 and 1997 labour reforms promoting permanent employment affected establishments’ employment practices. Generally, establishments’ prior employment expectations are realized through changes in all job and worker flows. However, establishments uniquely rely on temporary hires as a buffer to confront diminishing long-run employment expectations. None of the reforms significantly affected establishments’ net temporary or permanent employment flows.http://deepblue.lib.umich.edu/bitstream/2027.42/40032/3/wp646.pd
Multimodal Treatment Eliminates Cancer Stem Cells and Leads to Long-Term Survival in Primary Human Pancreatic Cancer Tissue Xenografts.
Copyright: 2013 Hermann et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.PURPOSE: In spite of intense research efforts, pancreatic ductal adenocarcinoma remains one of the most deadly malignancies in the world. We and others have previously identified a subpopulation of pancreatic cancer stem cells within the tumor as a critical therapeutic target and additionally shown that the tumor stroma represents not only a restrictive barrier for successful drug delivery, but also serves as a paracrine niche for cancer stem cells. Therefore, we embarked on a large-scale investigation on the effects of combining chemotherapy, hedgehog pathway inhibition, and mTOR inhibition in a preclinical mouse model of pancreatic cancer. EXPERIMENTAL DESIGN: Prospective and randomized testing in a set of almost 200 subcutaneous and orthotopic implanted whole-tissue primary human tumor xenografts. RESULTS: The combined targeting of highly chemoresistant cancer stem cells as well as their more differentiated progenies, together with abrogation of the tumor microenvironment by targeting the stroma and enhancing tissue penetration of the chemotherapeutic agent translated into significantly prolonged survival in preclinical models of human pancreatic cancer. Most pronounced therapeutic effects were observed in gemcitabine-resistant patient-derived tumors. Intriguingly, the proposed triple therapy approach could be further enhanced by using a PEGylated formulation of gemcitabine, which significantly increased its bioavailability and tissue penetration, resulting in a further improved overall outcome. CONCLUSIONS: This multimodal therapeutic strategy should be further explored in the clinical setting as its success may eventually improve the poor prognosis of patients with pancreatic ductal adenocarcinoma
The CALBC Silver Standard Corpus for Biomedical Named Entities - A Study in Harmonizing the Contributions from Four Independent Named Entity Taggers
The production of gold standard corpora is time-consuming and costly. We propose an alternative: the 'silver standard corpus' (SSC), a corpus that has been generated by the harmonisation of the annotations that have been delivered from a selection of annotation systems. The systems have to share the type system for the annotations and the harmonisation solution has use a suitable similarity measure for the pair-wise comparison of the annotations. The annotation systems have been evaluated against the harmonised set (630.324 sentences, 15, 956, 841 tokens). We can demonstrate that the annotation of proteins and genes shows higher diversity across all used annotation solutions leading to a lower agreement against the harmonised set in comparison to the annotations of diseases and species. An analysis of the most frequent annotations from all systems shows that a high agreement amongst systems leads to the selection of terms that are suitable to be kept in the harmonised set. This is the first large-scale approach to generate an annotated corpus from automated annotation systems. Further research is required to understand, how the annotations from different systems have to be combined to produce the best annotation result for a harmonised corpus
A Bayesian adaptive design for biomarker trials with linked treatments.
BACKGROUND: Response to treatments is highly heterogeneous in cancer. Increased availability of biomarkers and targeted treatments has led to the need for trial designs that efficiently test new treatments in biomarker-stratified patient subgroups. METHODS: We propose a novel Bayesian adaptive randomisation (BAR) design for use in multi-arm phase II trials where biomarkers exist that are potentially predictive of a linked treatment's effect. The design is motivated in part by two phase II trials that are currently in development. The design starts by randomising patients to the control treatment or to experimental treatments that the biomarker profile suggests should be active. At interim analyses, data from treated patients are used to update the allocation probabilities. If the linked treatments are effective, the allocation remains high; if ineffective, the allocation changes over the course of the trial to unlinked treatments that are more effective. RESULTS: Our proposed design has high power to detect treatment effects if the pairings of treatment with biomarker are correct, but also performs well when alternative pairings are true. The design is consistently more powerful than parallel-groups stratified trials. CONCLUSIONS: This BAR design is a powerful approach to use when there are pairings of biomarkers with treatments available for testing simultaneously.This work was supported by the Medical Research Council (grant number G0800860) and the NIHR Cambridge Biomedical Research Centre.This is the final version of the article. It first appeared from NPG via http://dx.doi.org/10.1038/bjc.2015.27
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