1,168 research outputs found
EFECTO DE LA GnRH EN EL PROCESO DEL RECONOCIMIENTO MATERNAL DE LA PREÑEZ SOBRE LA SUPERVIVENCIA EMBRIONARIA EN ALPACAS
El efecto de la GnRH sobre el porcentaje de supervivencia embrionaria durante el periodo del reconocimiento maternal de la preñez, fue evaluado en 67 alpacas adultas receptivas al macho y que a la ecografÃa presentaban un folÃculo preovulatorio ≥7 mm. Los animales se distribuyeron en 3 grupos: G0 (n=23) como control; G1(n=22) que recibió 6 µg GnRH el dÃa 4 post-ovulación; y G2(n=22) que recibió 4 µg GnRH los dÃas 8 y 9 postovulación. La ocurrencia de ovulación fue confirmada por la detección del cuerpo lúteo (CL) en el dÃa 5 post-ovulación. La fertilización y viabilidad de la gestación fue monitoreada por el desarrollo del CL, cambios estructurales de los cuernos uterinos y presencia de la vesÃcula embrionaria en los dÃas 12, 18, 25 y 30 post-ovulación por ecografÃa transrectal de los ovarios y útero. Simultáneamente se evaluó la receptividad sexual de la hembra al macho. El número de hembras que ovularon fue 20, 22 y 21 para G0, G1 y G2, respectivamente, considerándose que se encontraban gestantes (dÃa 5); sin embargo, en el dÃa 12 el porcentaje de supervivencia fue de 90.5% en G1, 75% en G0 y 76.2% en G2. El porcentaje de supervivencia embrionaria fue significativamente mayor en el dÃa 25 y 30 (p<0.05) entre G1 (76.2%) y G2 (42.9%). El diámetro folicular en G2 presentó una constante disminución desde el dÃa 0 hacia los dÃas 5 y 12 post-ovulación (7.4, 7.3 y 6.3 mm, respectivamente). El tamaño del CL en hembras que mantuvieron la gestación se incrementó desde el dÃa 5 hacia los dÃas 12 y 18 post-ovulación, mientras que los de hembras con mortalidad embrionaria presentaron una disminución significativa (p<0.01) desde el dÃa 12 postovulación. El diámetro del CL y del folÃculo mostraron una relación inversamente proporcional con respecto a la mortalidad embrionaria. Se concluye que la GnRH disminuyó el tamaño del folÃculo dominante y la tasa de sobrevivencia embrionaria durante el periodo del reconocimiento maternal de la preñez.The effect of GnRH administered around the time of maternal recognition of prenancy on the embryonic survival rate was studied. It was used 67 adult female alpacas sexually receptive to the male, and bearing a preovulatory follicle ≥7mm, detected by rectal ultrasonography. Animals were distributed in three groups: G0 (n=23) as control; G1 (n=22) received 6 µg GnRH on day 4 after ovulation; and G2 (n=22) received 4 µg GnRH on days 8 and 9 after ovulation. The ocurrence of ovulation was confirmed through the detection of a corpus luteum (CL) on day 5 after ovulation. Fertilization and gestation viab-ility were monitored by CL development, structural changes of the uterine horns and presence of the embryonic vesicle on days 12, 18, 25 and 30 after ovulation, using rectal ultrasonography. The female sexual receptivity to the male was simultaneously evaluated. The number of females that ovulate was 20, 22 and 21 in G0, G1, and G2 respectively, and was presumed that conception has occurred. However, on day 12, the embryo survival rate was 90.5% in G1, 75.0% in G0,and 76.2% in G2. These values were statistically different (p<0.05) on day 25 and 30 between G1 (76.2%) and G2 (42.9%). The follicle diameter in G2 showed a continuos decrease from day 0 to day 5 and 12 after ovulation (7.4, 7.3 and 6.3 mm, respectively). The CL size of females that maintained pregnancy showed an increase from day 5 to day 12 and 18 after ovulation, while those of females that had embryonic mortality showed a significant (p<0.01) decrease since day 12 onwards. There was an inverse relationship between the diameter of CL and follicle size with embryonic mortality. It is concluded that GnRH decreased the size of the dominant follicle and embryo survival rate when applied around the time of maternal recognition of pregnancy
Effects of intrauterine food restriction and long-term dietary supplementation with L-arginine on age-related changes in renal function and structure of rats
We have previously demonstrated that restricting intrauterine food by 50% in 3-mo-old rats produced lower nephron numbers and early-onset hypertension, the latter being normalized by L-arginine administration. in 18-mo-old rats, such restriction increased glomerulosclerosis. in this study, we expanded our investigation, evaluating functional, morphologic, and immunohistochemical parameters in intrauterine-food-restricted 18-mo-old rats, either receiving L-arginine (RA18) or not (R18). Age-matched, non-food-restricted controls were assigned to similar groups with L-arginine (CA18) and without (C18). After weaning, L-arginine was given daily for 17 mo. No functional or morphologic changes were observed in C IS rats. the R18 rats developed early-onset hypertension, which persisted throughout the observation period, as well its significant proteinuria from 12 mo on. in RA18 rats, L-arginine decreased both blood pressure levels and proteinuria, and glomerular diameter was si,significantly smaller than in R18 rats (115.63 +/- 2.2 versus 134.8 +/- 1.0 mu m, p < 0.05). However, in RA18 rats, glomerular filtration rate remained depressed. Although L-arginine prevented glomerulosclerosis (R18 = 14%, RA18 = 4%; p < 0.05), glomerular expression of fibronectin and desmin was still greater in RA18 rats than in controls. Our data show that, although L-arginine prevented hypertension and proteinuria, glomerular injury still occurred, suggesting that intrauterine food restriction may be one of the leading causes of impaired renal function in adult life.Universidade Federal de São Paulo, Dept Physiol, EPM, Dept Physiol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, EPM, Dept Morphol,Embrol Div, BR-04023900 São Paulo, BrazilUniv São Paulo, Ribeirao Preto Sch Med, Dept Physiol & Biophys, Brookline, MA 02146 USAUniversidade Federal de São Paulo, Dept Physiol, EPM, Dept Physiol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, EPM, Dept Morphol,Embrol Div, BR-04023900 São Paulo, BrazilWeb of Scienc
Flavor of quiver-like realizations of effective supersymmetry
We present a class of supersymmetric models which address the flavor puzzle
and have an inverted hierarchy of sfermions. Their construction involves
quiver-like models with link fields in generic representations. The magnitude
of Standard-Model parameters is obtained naturally and a relatively heavy Higgs
boson is allowed without fine tuning. Collider signatures of such models are
possibly within the reach of LHC in the near future.Comment: LaTeX, 17 pages, 3 figures. V2: reference adde
Estimating the long-term impact of a prophylactic human papillomavirus 16/18 vaccine on the burden of cervical cancer in the UK
To predict the public health impact on cervical disease by introducing human papillomavirus (HPV) vaccination in the United Kingdom, we developed a mathematical model that can be used to reflect the impact of vaccination in different countries with existing screening programmes. Its use is discussed in the context of the United Kingdom. The model was calibrated with published data. The impact of vaccination on cervical cancer and deaths, precancerous lesions and screening outcomes were estimated for a vaccinated cohort of 12-year-old girls, among which it is estimated that there would be a reduction of 66% in the prevalence of high-grade precancerous lesions and a 76% reduction in cervical cancer deaths. Estimates for various other measures of the population effects of vaccination are also presented. We concluded that it is feasible to forecast the potential effects of HPV vaccination in the context of an existing national screening programme. Results suggest a sizable reduction in the incidence of cervical cancer and related deaths. Areas for future research include investigation of the beneficial effects of HPV vaccination on infection transmission and epidemic dynamics, as well as HPV-related neoplasms in other sites
Estresse e Burnout entre residentes multiprofissionais
OBJECTIVE: To identify associations between high-stress and burnout syndrome in multidisciplinary residents from a federal university in Rio Grande do Sul, Brazil. METHOD: This is an analytical, cross-sectional and quantitative study. A socio-demographic questionnaire, the Work Stress Scale and the Maslach Burnout Inventory-Health Services Survey (MBI-HSS) were applied to 37 residents between April and June 2011. P-valuesOBJETIVO: Identificar la asociación entre alto estrés y Burnout en residentes Multiprofesionales de una universidad federal de Rio Grande do Sul. MÉTODO: se trata de un estudio analÃtico, transversal, cuantitativo. Se aplicaron un formulario de datos socio-demográficos, la Escala de Estrés en el Trabajo y el Maslach Burnout Inventory- Health Services en 37 residentes entre Abril y Junio de 2011. Valores de pOBJETIVO: identificar a associação entre alto estresse e Burnout em residentes multiprofissionais de uma universidade federal do Rio Grande do Sul. MÉTODO: trata-se de estudo analÃtico, transversal, quantitativo. Aplicaram-se um formulário de dados socio demográficos, a Escala de Estresse no Trabalho e o Maslach Burnout Inventory-Human Services Survey (MBI-HSS) em 37 residentes entre abril e junho de 2011. Valores de
Seascape genetics of the Atlantic Spotted Dolphin (Stenella frontalis) based on mitochondrial DNA
The Atlantic spotted dolphin (Stenella frontalis) is endemic to tropical, subtropical, and warm temperate waters of the Atlantic Ocean. Throughout its distribution, both geographic distance and environmental variation may contribute to population structure of the species. In this study, we follow a seascape genetics approach to investigate population differentiation of Atlantic spotted dolphins based on a large worldwide dataset and the relationship with marine environmental variables. The results revealed that the Atlantic spotted dolphin exhibits population genetic structure across its distribution based on mitochondrial DNA control region (mtDNA-CR) data. Analyses based on the contemporary landscape suggested, at both the individual and population level, that the population genetic structure is consistent with the isolation-by-distance model. However, because geography and environmental matrices were correlated, and because in some, but not all analyses, we found a significant effect for the environment, we cannot rule out the addition contribution of environmental factors in structuring genetic variation. Future analyses based on nuclear data are needed to evaluate whether local processes, such as social structure and some level of philopatry within populations, may be contributing to the associations among genetic structure, geographic, and environmental distance.info:eu-repo/semantics/acceptedVersio
Birth weight and melanoma risk: a population-based case–control study
We investigated whether lower birth weight was associated with lower risk of melanoma later in life. This population-based case–control study included all incident cases of histologically verified invasive melanoma diagnosed until 31 December 2003 in the Norwegian population born between 1967 and 1986 (n=709). The control group without malignant disease was established by random sampling from the same source population as the cases (n=108 209). Data on birth weight, gender, mother's residence and parental age at the time of birth were collected from the Medical Birth Registry of Norway and data on cancer from the Cancer Registry of Norway. The Mantel–Haenszel test of linear trend showed no trend in risk across the birth weight categories: individuals in the highest quartile of birth weight (⩾3860 g) had an odds ratio (OR) of 1.19 (95% confidence interval, CI: 0.77–1.84) compared to individuals with birth weight <2500 g. The adjusted OR was 0.81 (95% CI: 0.52–1.26) for birth weight below 2500 g (exposed). Though not statistically significant, the results suggest that low birth weight might influence the risk of melanoma later in life
Human African Trypanosomiasis in South Sudan: How Can We Prevent a New Epidemic?
Human African trypanosomiasis (HAT) has been a major public health problem in South Sudan for the last century. Recurrent outbreaks with a repetitive pattern of responding-scaling down activities have been observed. Control measures for outbreak response were reduced when the prevalence decreased and/or socio-political crisis erupted, leading to a new increase in the number of cases. This paper aims to raise international awareness of the threat of another outbreak of sleeping sickness in South Sudan. It is a review of the available data, interventions over time, and current reports on the status of HAT in South Sudan. Since 2006, control interventions and treatments providing services for sleeping sickness have been reduced. Access to HAT diagnosis and treatment has been considerably diminished. The current status of control activities for HAT in South Sudan could lead to a new outbreak of the disease unless 1) the remaining competent personnel are used to train younger staff to resume surveillance and treatment in the centers where HAT activities have stopped, and 2) control of HAT continues to be given priority even when the number of cases has been substantially reduced. Failure to implement an effective and sustainable system for HAT control and surveillance will increase the risk of a new epidemic. That would cause considerable suffering for the affected population and would be an impediment to the socioeconomic development of South Sudan
Strong coupling, discrete symmetry and flavour
We show how two principles - strong coupling and discrete symmetry - can work
together to generate the flavour structure of the Standard Model. We propose
that in the UV the full theory has a discrete flavour symmetry, typically only
associated with tribimaximal mixing in the neutrino sector. Hierarchies in the
particle masses and mixing matrices then emerge from multiple strongly coupled
sectors that break this symmetry. This allows for a realistic flavour
structure, even in models built around an underlying grand unified theory. We
use two different techniques to understand the strongly coupled physics:
confinement in N=1 supersymmetry and the AdS/CFT correspondence. Both
approaches yield equivalent results and can be represented in a clear,
graphical way where the flavour symmetry is realised geometrically.Comment: 31 pages, 5 figures, updated references and figure
Cost-effectiveness of human papillomavirus vaccination for prevention of cervical cancer in Taiwan
<p>Abstract</p> <p>Background</p> <p>Human papillomavirus (HPV) infection has been shown to be a major risk factor for cervical cancer. Vaccines against HPV-16 and HPV-18 are highly effective in preventing type-specific HPV infections and related cervical lesions. There is, however, limited data available describing the health and economic impacts of HPV vaccination in Taiwan. The objective of this study was to assess the cost-effectiveness of prophylactic HPV vaccination for the prevention of cervical cancer in Taiwan.</p> <p>Methods</p> <p>We developed a Markov model to compare the health and economic outcomes of vaccinating preadolescent girls (at the age of 12 years) for the prevention of cervical cancer with current practice, including cervical cytological screening. Data were synthesized from published papers or reports, and whenever possible, those specific to Taiwan were used. Sensitivity analyses were performed to account for important uncertainties and different vaccination scenarios.</p> <p>Results</p> <p>Under the assumption that the HPV vaccine could provide lifelong protection, the massive vaccination among preadolescent girls in Taiwan would lead to reduction in 73.3% of the total incident cervical cancer cases and would result in a life expectancy gain of 4.9 days or 8.7 quality-adjusted life days at a cost of US23,939 per life year gained or US30,000 per QALY under most conditions, even when vaccine efficacy was suboptimal or when vaccine-induced immunity required booster shots every 13 years.</p> <p>Conclusions</p> <p>Although gains in life expectancy may be modest at the individual level, the results indicate that prophylactic HPV vaccination of preadolescent girls in Taiwan would result in substantial population benefits with a favorable cost-effectiveness ratio. Nevertheless, we should not overlook the urgency to improve the compliance rate of cervical screening, particularly for older individuals.</p
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