667 research outputs found
Application of longitudinal data analysis allows to detect differences in pre‐breeding growing curves of 24‐month calving Angus heifers under two pasture‐based system with differential puberty onset
Background. Longitudinal data analysis contributes to detect differences in the growing curve by exploiting all the information involved in repeated measurements, allowing to distinguish changes over time within individuals, from differences in the baseline levels among groups. In this research longitudinal and cross-sectional analysis were compared to evaluate differences in growth in Angus heifers under two different grazing conditions, ad libitum (AG) and controlled (CG) to gain 0.5 kg/day. Results. Longitudinal mixed models show differences in growing curves parameters between grazing conditions, that were not detected by cross sectional analysis. Differences (P < 0.05) in first derivative of growth curves (daily gain) until 289 days were observed between treatments, being AG higher than CG. Correspondingly, pubertal heifer proportion was also higher in AG at the end of rearing (AG 0.94; CG 0.67). Conclusion. In longitudinal studies, the power to detect differences between groups increases by exploiting the whole information of repeated measures, modelling the relation between measurements performed on the same individual. Under a proper analysis valid conclusion can be drawn with less animals in the trial, improving animal welfare and reducing investigation costs.Fil: Bonamy, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: de Iraola, Julieta Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Prando, Alberto José. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Baldo, Andres. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Giovambattista, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Rogberg Muñoz, Andres. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin
Identification of appropriate housekeeping genes for quantitative RT-PCR analysis in MDA-MB-231 and NCI-H460 human cancer cell lines under hypoxia and serum deprivation
Gene expression studies aimed at analyzing cancer cells under hypoxia and serum deprivation conditions show major potential for understanding molecular mechanisms associated with tumor progression as well as resistance to antitumor agents. To the
best of our knowledge, a study for the identification of appropriate housekeeping genes in breast and lung cancer cells under
hypoxia and serum deprivation conditions is currently missing. Given the relevance of a reliable and accurate normalization, we
herein aimed to identify the appropriate housekeeping genes for breast and lung cancer cell lines cultured under hypoxia and/or
serum deprivation. The stability of five commonly used housekeeping genes (ACTB,
β
2M, GUSB, 18S rRNA, and PPIA) was
assessed after reverse-transcription quantitative real-time PCR in MDA-MB-231 and NCI-H460 cancer cell lines using GeNorm,
NormFinder and BestKeeper software. GeNorm and NormFinder ranking revealed ACTB, GUSB and PPIA as the most stable
genes for both tumor cell lines. Our results support the use of ACTB/PPIA for MDA-MB-231 and GUSB/PPIA for NCI-H460
cells as the most stable combination for normalization of gene expression under hypoxic and serum deprivation conditions. Our
results highlight the importance of the selection of the housekeeping genes in cancer cells subjected to different physiological
stresses, such as hypoxia and serum deprivation.This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nıvel Superior (CAPES) [grant agreement No. 88881.132780/2016-01]; Fundac ão de Amparoa Ciência e Tecnologia de Pernambuco (FACEPE) [grant agreement No. 0883-2.08/13];and the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie [grant agreement No. 748880]. This work was also funded by the project NORTE-01-0145-FEDER-000029, supported by Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); and by FEDER—Fundo Europeu de Desenvolvimento Regional funds through COMPETE 2020—Operational Programme for Competitiveness and Internationalization (POCI), Portugal 2020,and by Portuguese funds through FCT (Fundação para a Ciência e a Tecnologia)/Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274), and the project POCI-01-0145-FEDER-016585 (PTDC/BBB EBI/0567/2014)
A comprehensive characterization of chronic norovirus infection in immunodeficient hosts.
Letter to the edito
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Design of a 7-MV Linear Transformer Driver (LTD) for down-hole flash x-ray radiography.
Pulsed power driven flash x-ray radiography is a valuable diagnostic for subcritical experiments at the Nevada Test Site. The existing dual-axis Cygnus system produces images using a 2.25 MV electron beam diode to produce intense x-rays from a small source. Future hydrodynamic experiments will likely use objects with higher areal mass, requiring increased x-ray dose and higher voltages while maintaining small source spot size. A linear transformer driver (LTD) is a compact pulsed power technology with applications ranging from pulsed power flash x-ray radiography to high current Z-pinch accelerators. This report describes the design of a 7-MV dual-axis system that occupies the same lab space as the Cygnus accelerators. The work builds on a design proposed in a previous report [1]. This new design provides increased diode voltage from a lower impedance accelerator to improve coupling to low impedance diodes such as the self magnetic pinch (SMP) diode. The design also improves the predicted reliability by operating at a lower charge voltage and removing components that have proven vulnerable to failure. Simulations of the new design and experimental results of the 1-MV prototype are presented
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DRSPALL :spallings model for the Waste Isolation Pilot Plant 2004 recertification.
This report presents a model to estimate the spallings releases for the Waste Isolation Pilot Plant Performance Assessment (WIPP PA). A spallings release in the context of WIPP PA refers to a portion of the solid waste transported from the subsurface repository to the ground surface due to inadvertent oil or gas drilling into the WIPP repository at some time after site closure. Some solid waste will be removed by the action of the drillbit and drilling fluid; this waste is referred to as cuttings and cavings. If the repository is pressurized above hydrostatic at the time of intrusion, solid waste material local to the borehole may be subject to mechanical failure and entrainment in high-velocity gases as the repository pressure is released to the borehole. Solid material that fails and is transported into the wellbore and thus to the surface comprise the spallings releases. The spallings mechanism is analogous to a well blowout in the modern oil and gas drilling industry. The current spallings conceptual model and associated computer code, DRSPALL, were developed for the 2004 recertification because the prior spallings model used in the 1996 WIPP Compliance Certification Application (CCA) was judged by an independent peer review panel as inadequate (DOE 1996, 9.3.1). The current conceptual model for spallings addresses processes that take place several minutes before and after a borehole intrusion of a WIPP waste room. The model couples a pipe-flow wellbore model with a porous flow repository model, allowing high-pressure gas to flow from the repository to the wellbore through a growing cavity region at the well bottom. An elastic stress model is applied to the porous solid domain that allows for mechanical failure of repository solids if local tensile stress exceeds the tensile strength of the waste. Tensile-failed solids may be entrained into the wellbore flow stream by a fluidized bed model, in which case they are ultimately transported to the land surface comprising a release. In July 2003, DOE/SNL presented the spallings conceptual model to a independent peer review panel in accordance with NUREG 1297 guidelines (NRC, 1988). The panel ultimately judged the model as adequate for implementation in WIPP PA (Yew et al., 2003). This report documents the spallings model history from 1997 to the implementation of DRSPALL in the 2004 Compliance Recertification Application (CRA) (DOE, 2004). The scope of this report includes descriptions of the conceptual model, numerical model, verification and validation techniques, model sensitivity studies, and WIPP PA spallings results as presented in the 2004 CRA
Effects of ropivacaine combined with morphine at 0.15 and 0.2 mg kg-1 in bitches undergoing epidural anesthesia
Mass Spectrometric Analyses of Organophosphate Insecticide Oxon Protein Adducts
OBJECTIVE: Organophosphate (OP) insecticides continue to be used to control insect pests. Acute and chronic exposures to OP insecticides have been documented-to cause adverse health effects, but few OP-adducted proteins have been correlated with these illnesses at the molecular level. Our aim was to review the literature covering the current state of the art in mass spectrometry (MS) used to identify OP protein biomarkers. DATA SOURCES AND EXTRACTION: We identified general and specific research reports related to OP insecticides, OP toxicity, OP structure, and protein MS by searching PubMed and Chemical Abstracts for articles published before December 2008. DATA SYNTHESIS: A number of OP-based insecticides share common structural elements that result in predictable OP-protein adducts. The resultant OP-protein adducts show an increase in molecular mass that can be identified by MS and correlated with the OP agent. Customized OP-containing probes have also been used to tag and identify protein targets that can be identified by MS. CONCLUSIONS: MS is a useful and emerging tool for the identification of proteins that are modified by activated organophosphate insecticides. MS can characterize the structure of the OP adduct and also the specific amino acid residue that forms the key bond with the OP. Each protein that is modified in a unique way by an OP represents a unique molecular biomarker that with further research can lead to new correlations with exposure
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Recyclable transmission line concept for z-pinch driven inertial fusion energy.
Recyclable transmission lines (RTL)s are being studied as a means to repetitively drive z pinches to generate fusion energy. We have shown previously that the RTL mass can be quite modest. Minimizing the RTL mass reduces recycling costs and the impulse delivered to the first wall of a fusion chamber. Despite this reduction in mass, a few seconds will be needed to reload an RTL after each subsequent shot. This is in comparison to other inertial fusion approaches that expect to fire up to ten capsules per second. Thus a larger fusion yield is needed to compensate for the slower repetition rate in a z-pinch driven fusion reactor. We present preliminary designs of z-pinch driven fusion capsules that provide an adequate yield of 1-4 GJ. We also present numerical simulations of the effect of these fairly large fusion yields on the RTL and the first wall of the reactor chamber. These simulations were performed with and without a neutron absorbing blanket surrounding the fusion explosion. We find that the RTL will be fully vaporized out to a radius of about 3 meters assuming normal incidence. However, at large enough radius the RTL will remain in either the liquid or solid state and this portion of the RTL could fragment and become shrapnel. We show that a dynamic fragmentation theory can be used to estimate the size of these fragmented particles. We discuss how proper design of the RTL can allow this shrapnel to be directed away from the sensitive mechanical parts of the reactor chamber
Quantitative effects of tobacco smoking exposure on the maternal-fetal circulation
<p>Abstract</p> <p>Background</p> <p>Despite the existence of various published studies regarding the effects of tobacco smoking on pregnancy, and especially in regards to placental blood flow and vascular resistance, some points still require clarification. In addition, the amount of damage due to tobacco smoking exposure that occurs has not been quantified by objective means. In this study, we looked for a possible association between flow resistance indices of several arteries and the levels of urinary cotinine and the concentration of carbon monoxide in the exhaled air (COex) of both smoking and non-smoking pregnant women. We also looked for a relationship between those findings and fetal growth and birth weight.</p> <p>Methods</p> <p>In a prospective design, thirty pregnant smokers and thirty-four pregnant non-smokers were studied. The volunteers signed consent forms, completed a self-applied questionnaire and were subjected to Doppler velocimetry. Tobacco smoking exposure was quantified by subject provided information and confirmed by the measurement of urinary cotinine levels and by the concentration of carbon monoxide in the exhaled air (COex). The weight of newborns was evaluated immediately after birth.</p> <p>Results</p> <p>Comparing smoking to non-smoking pregnant women, a significant increase in the resistance index was observed in the uterine arteries (P = 0.001) and umbilical artery (P = 0.001), and a decrease in the middle cerebral artery (P = 0.450). These findings were associated with progressively higher concentrations of COex and urinary cotinine. A decrease in the birth weight was also detected (P < 0.001) in association with a progressive increase in the tobacco exposure of the pregnant woman.</p> <p>Conclusions</p> <p>In pregnant women who smoke, higher arterial resistance indices and lower birth weights were observed, and these findings were associated with increasing levels of tobacco smoking exposure. The values were significantly different when compared to those found in non-smoking pregnant women. This study contributes to the findings that smoking damage during pregnancy is dose-dependent, as demonstrated by the objective methods for measuring tobacco smoking exposure.</p
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