Correlation equalities and upper bounds for the transverse Ising model

Starting from an exact formal identity for the two-state transverse Ising model and using correlation inequalities rigorous upper bounds for the critical temperature and the critical transverse field are obtained which improve effective results.Comment: 8 pages, 1 figur

Phytoplankton phagotrophy across nutrients and light gradients using different measurement techniques

Mixotrophy is important to ecosystems functioning. Assuming that limiting resources induce phagotrophy in mixotrophs, we used a factorial experimental design to evaluate how nutrient and light affects phagotrophy in two mixotrophic phytoflagellates belonging to different lineages. We estimated cell-specific grazing rates (CSGR) by analyzing prey ingestion using microscopy and flow cytometry (FC). Furthermore, we tested if the acidotropic probe LysoTracker green (LyTG) can be used to differentiate autotrophs from mixotrophs. Cryptomonas marssonii (cryptophyte) had higher CSGR in high-nutrient treatments. Although it seems counterintuitive, phytoflagellates likely uses phagotrophy to obtain organic growth factors instead of inorganic nutrients when photosynthesis is more favorable. In contrast, CSGR in Ochromonas tuberculata (chrysophyte) increased when light decreased, suggesting that it uses phagotrophy to supplement carbon when autotrophic growth conditions are suboptimal. Measurements of CSGR obtained by FC and microscopy were significantly correlated and displayed the same trend among treatments, although FC rates tended to be higher. Fluorescence with LyTG did not differ from the control in the non-phagotrophic chlorophyte. Contrarily, addition of LyTG significantly increased the fluorescence in chrysophytes and cryptophytes, although no differences were observed among treatments. This approach allowed for differentiation between phagotrophic and non-phagotrophic flagellates but failed to quantify mixotrophy.Fil: Costa, Mariana R. A.. Universidade Federal do Rio Grande do Norte; BrasilFil: Sarmento, Hugo. Universidade Federal do São Carlos; BrasilFil: Becker, Vanessa. Universidade Federal do Rio Grande do Norte; BrasilFil: Bagatini, Inessa L. Universidade Federal do São Carlos; BrasilFil: Unrein, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; Argentin

Peripheral arterial tonometry as a method of measuring reactive hyperaemia correlates with organ dysfunction and prognosis in the critically ill patient: a prospective observational study

Predictions of mortality may help in the selection of patients who benefit from intensive care. Endothelial dysfunction is partially responsible for many of the organic dysfunctions in critical illness. Reactive hyperaemia is a vascular response of the endothelium that can be measured by peripheral arterial tonometry (RH-PAT). We aimed to assess if reactive hyperaemia is affected by critical illness and if it correlates with outcomes. Prospective study with a cohort of consecutive patients admitted to an Intensive Care Unit. RH-PAT was accessed on admission and on the 7th day after admission. Early and late survivors were compared to non-survivors. The effect of RH-PAT variation on late mortality was studied by a logistic regression model. The association between RH-PAT and severity scores and biomarkers of organic dysfunction was investigated by multivariate analysis. 86 patients were enrolled. Mean ln(RHI) on admission was 0.580 and was significantly lower in patients with higher severity scores (p < 0.01) and early non-survivors (0.388; p = 0.027). The model for prediction of early-mortality estimated that each 0.1 decrease in ln(RHI) increased the odds for mortality by 13%. In 39 patients, a 2nd RH-PAT measurement was performed on the 7th day. The variation of ln(RHI) was significantly different between non-survivors and survivors (− 24.2% vs. 63.9%, p = 0.026). Ln(RHI) was significantly lower in patients with renal and cardiovascular dysfunction (p < 0.01). RH-PAT is correlated with disease severity and seems to be an independent marker of early mortality, cardiovascular and renal dysfunctions. RH-PAT variation predicts late mortality. There appears to be an RH-PAT impairment in the acute phase of severe diseases that may be reversible and associated with better outcomes.Professor Rita Gaio was partially supported by CMUP (UID/MAT/00144/2013), which is funded by FCT (Portugal) with national (MEC) and European structural funds (FEDER), under the partnership agreement PT2020

Comparação de homogeneidade e heteroneneidade de variância residual em modelos de regressão aleatória na descrição do crescimento de ovinos Santa Inês.

Resumo: Utilizaram-se 17.767 registros de pesos de cordeiros da raça Santa Inês com o objetivo de comparar modelos de regressão aleatória com diferentes estruturas para modelar a variância residual. As regressões fixas e aleatórias foram ajustadas por meio de polinômios de Legendre de ordens quatro e três, respectivamente. A variância residual foi ajustada por meio de classes e funções de variâncias. O modelo considerando homogeneidade de variâncias residuais mostrou-se inadequado. De acordo com os critérios utilizados, a variância residual contendo sete classes heterogêneas proporcionou melhor ajuste, embora um mais parcimonioso, com cinco classes, poderia ser utilizado. O ajuste de funções de variâncias com qualquer ordem foi melhor que o obtido por meio de classes, sendo que o polinômio ordinário de ordem seis proporcionou melhor ajuste dentre as estruturas testadas. A modelagem do resíduo interferiu nas estimativas dos parâmetros genéticos. Além da alteração da classificação dos reprodutores, constataramse, também, alterações consideráveis na magnitude dos valores genéticos preditos em função do ajuste da variância residual empregado. Portanto, faz-se necessário a utilização de heterogeneidade de variâncias residuais para modelar as variâncias associadas à curva de crescimento dos ovinos Santa Inês em estudo. Comparison of homogeneity and heterogeneity of residual variance in random regression models in the description of the growth of Santa Inês sheep]. Abstract: Data set of 17,767 records of 4,210 Santa Inês lambs were used aiming to compare random regression models with different structures to fit the residual variance. Fixed and random regressions were fitted by Legendre polynomials of orders four and three, respectively. The residual variance was fitted by classes and functions of variances. The model considering homogeneity of residual variances was inadequate. According to the criteria used, the residual variance containing seven heterogeneous classes provided the best fit, although a more parsimonious one, with five classes, could be used. The fit of variances functions with any order was better than that obtained by classes and the ordinary polynomial of order six provided best fit among the tested structures. The modelling of the residue interfered the estimative of the genetic parameters. Beyond the Change in the classification of the reproducers it was verified alterations in the magnitude of the genetic values predicted as function of the fit of the variance residual studied. Therefore, it is necessary the use of residual heterogeneity variances to model the variances associated to the growth curve of Santa Inês sheep in study

Estimação de componentes de variância e parâmetros genéticos para pesos do nascimento aos 196 dias de idade em ovinos Santa Inês por meio de modelo multicaracterística.

Resumo: O trabalho foi conduzido com o objetivo de estimar os componentes de variância e parâmetros genéticos para os pesos ao nascer, 56, 112 e 196 dias de idade em ovinos Santa Inês por meio de um modelo animal em análise multicaracterística. O modelo de análise inclui os efeitos aleatórios genéticos aditivos direto e materno e de ambiente permanente materno. Os efeitos fixos utilizados na análise foram os de grupo contemporâneo e idade da mãe ao parto, como covariável. As herdabilidades diretas estimadas para os pesos ao nascer, 56, 112 e 196 dias de idade foram, respectivamente, 0,17, 0,05, 0,08 e 0,10. Os resultados encontrados indicam que o ganho genético obtido por meio de seleção individual será pequeno. O efeito materno apresentou influência sobre os pesos estudados. Variance components and genetics parameters estimation for birth weight to the 196-days in Santa Inês sheep using multiple-trast model. Abstract: The study was carried out with the objective to stimate the variance components and genetics parameters for birth weights 56, 112 and 196-day in Santa Inês sheep using multiple-trast animal model. The molysis model includes the direct additive and maternal genetic effect and permanent maternal environmental effect. The fixed effects used in molysis were the contemporary group and age of dam lombing, as (co)varience. The estimate direct heritability for the weights at the birth, 56, 112 and 196 days of age were 0,17, 0,05, 0,08 and 0,10 respectively. The found results indicate that the genetic gain obtained through individual selection it will be small. The maternal effect presented influence on the weights studied

Modelos de regressão aleatória na avaliação genética do crescimento de ovinos da raça Santa Inês.

Utilizaram-se 17.767 registros de peso de 4.210 cordeiros da raça Santa Inês com o objetivo de comparar modelos de regressão aleatória com diferentes estruturas para modelar a variância residual em estudos genéticos da curva de crescimento. Os efeitos fixos incluídos na análise foram: grupo contemporâneo e idade da ovelha no parto. As regressões fixas e aleatórias foram ajustadas por meio de polinômios de Legendre de ordens 4 e 3, respectivamente. A variância residual foi ajustada por meio de classes heterogêneas e por funções de variância empregando polinômios ordinários e de Legendre de ordens 2 a 8. O modelo considerando homogeneidade de variâncias residuais mostrou-se inadequado. De acordo com os critérios utilizados, a variância residual contendo sete classes heterogêneas proporcionou melhor ajuste, embora um mais parcimonioso, com cinco classes, pudesse ser utilizado sem perdas na qualidade de ajuste da variância nos dados. O ajuste de funções de variância com qualquer ordem foi melhor que o obtido por meio de classes. O polinômio ordinário de ordem 6 proporcionou melhor ajuste entre as estruturas testadas. A modelagem do resíduo interferiu nas estimativas de variâncias e parâmetros genéticos. Além da alteração da classificação dos reprodutores, a magnitude dos valores genéticos preditos apresenta variações significativas, de acordo com o ajuste da variância residual empregado. [Random regression models on genetic evaluation on the growth of Santa Inês breed sheep]. Abstract: It was used 17,767 weight records of 4,210 Santa Inês breed lambs aiming to compare random regression models with different structures to model the residual variance in genetic studies of the growth curve. The fixed effects included in the analysis were contemporary group and age of the ewe at lambing. Fixed and random regressions were fitted through Legendry polynomials of orders 4 and 3, respectively. The residual variance was fitted by heterogeneous classes and by functions of variances employing ordinary polynomials and Legendry polynomials of the orders 2 to 8. The model considering homogeneity of residual variances was inadequate. Accordingly to the used criteria, the residual variance containing seven heterogeneous classes provided the best fit, although a more parsimonious one, with five classes, could be used without losses on the quality of variance fit on the data. The fit of functions of variances with any order was better than that obtained through classes. The ordinary polynomial of order 6 provided the best fit among the tested structures. The modeling of the residue interfered on the estimative of the variances and genetic parameters. In addition to changes in the classification of the reproducers, the magnitude of the predicted genetic values shows significant variations, accordingly to the fitting of the used residual variance

Estimativa de parâmetros genéticos para características reprodutivas em ovinos da raça Somalis Brasileira.

Estimativas de parâmetros genéticos para características reprodutivas são escassas em ovinos de corte e inexistentes na raça Somalis Brasileira. Assim, objetivou-se com este trabalho estimar parâmetros genéticos para características reprodutivas em ovinos da raça Somalis Brasileira, provenientes da Embrapa Caprinos e Ovinos, localizada na cidade de Sobral-CE, controlados pelo Programa de Melhoramento Genético de Caprinos e Ovinos de Corte (GENECOC). As características analisadas foram: intervalo de partos (IP), dias para o parto (DP) e número de serviços por concepção (NSC). As análises foram realizadas utilizando o método da Máxima Verossimilhança Restrita não Derivativa (DFREML), utilizando o programa MTDFREML, através de análises unicaracterística. As herdabilidades foram nulas para IP e DP e baixa para NSC. Abstract: Estimates of genetic parameters for reproductive traits in sheep are scarce and nonexistent in Somalis Brasileira breed. The aim of this work was to estimate genetic parameters for reproductive traits in Somalis Brasileira breed, from the flock of Embrapa Caprinos e Ovinos, located in the city of Sobral-CE, supported by Programa de Melhoramento Genético de Caprinos e Ovinos de Corte (GENECOC). The traits analyzed were: lambing interval (IP), lambing date (DP) and number of services per conception (NSC). The analyses were carried out by Derivative Free Restricted Maximum Likelihood (DFREML) method using the MTDFREML software, under univariate analyses. Heritabilities were zero for IP and DP and low for NSC

Comparação de dois modelos estatísticos para uso do peso a desmama como critério de seleção em ovinos da raça Somalis Brasileira.

O período pré-desmama dos animais é importante para avaliar a primeira fase no desenvolvimento dos mesmos, sob influência dos efeitos inerentes do próprio animal e de sua mãe. Geralmente os modelos de análise para peso ao desmame utilizam a idade como covariável para ajustar as diferenças na idade em que os animais são desmamados. Entretanto, é possível que o uso desta covariável remova variação genética entre os animais por desconsiderar as diferenças na velocidade de ganho de peso entre os mesmos. A utilização de um peso ajustado para uma idade padrão poderia contornar este viés, sendo uma alternativa mais eficiente. Objetivou-se com esse trabalho comparar por meio da estimativa de parâmetros genéticos de ovinos da raça Somalis Brasileira, a utilização da pesagem mensurada na desmama dos animais e ajustada pela idade como covariável (PD) com esta mesma pesagem ajustada para a idade padrão de 84 dias (P84), que consistiu na média de idade dos animais ao desmame. Os modelos de análise apresentaram distintos critérios à convergência e distintas ordens de classificação dos animais e reprodutores foram observadas. O PD e o P84, no caso deste estudo, são características com naturezas distintas sob análise. Abstract: The pre-weaning is important to evaluate the first phase of animal development, under the influence of its intrinsic effects and its mother effects. Usually the analysis models for weaning weihgt use age as a covariate to adjust for differences in age at which animals are weaned. However, it is possible that the use of this covariate remove genetic variation between animals for disregarding the differences in the rate of weight gain among them. The use of a weight adjusted to a standard age could circumvent this bias, being a more efficient alternative. The objective of this work was to compare by genetic parameters estimates of Brazilian Somali sheep breed, the use of the weight measured at weaning of the animals and adjusted for age as a covariate (PD) with the same weight adjusted for a standard age of 84 days (P84), which was the average age of animals at weaning. The models showed different convergence criteria and different orders of classification of animals and of rams were observed. The PD and P84, in the case of this study, are characteristic of distinct natures under review

Random regression models for the estimation of genetic and environmental covariance functions for growth traits in Santa Ines sheep.

Abstract: Polynomial functions of different orders were used to model random effects associated with weight of Santa Ines sheep from birth to 196 days. Fixed effects included in the models were contemporary groups, age of ewe at lambing, and fourth-order Legendre polynomials for age to represent the average growth curve. In the random part, functions of different orders were included to model variances associated with direct additive and maternal genetic effects and with permanent environmental effects of the animal and mother. Residual variance was fitted by a sixth-order ordinary polynomial for age. The higher the order of the functions, the better the model fit the data. According to the Akaike information criterion and likelihood ratio test, a continuous function of order, five, five, seven, and three for direct additive genetic, maternal genetic, animal permanent environmental, and maternal permanent environmental effects (k = 5573), respectively, was sufficient to model changes in (co)variances with age. However, a more parsimonious model of order three, three, five, and three (k = 3353) was suggested based on Schwarz's Bayesian information criterion for the same effects. Since it was a more flexible model, model k = 5573 provided inconsistent genetic parameter estimates when compared to the biologically expected result. Predicted breeding values obtained with models k = 3353 and k = 5573 differed, especially at young ages. Model k = 3353 adequately fit changes in variances and covariances with time, and may be used to describe changes in variances with age in the Santa Ines sheep studied