RESUMO
This study evaluates the joint impact of non-linearity and non-Gaussianity on predictive performance in 23 Brazilian monthly streamflow time series from 1931 to 2022. We consider point and interval forecasting, employing a PAR(p) model and comparing it with the periodic vine copula model. Results indicate that the Gaussian hypothesis assumed by PAR(p) is unsuitable; gamma and log-normal distributions prove more appropriate and crucial for constructing accurate confidence intervals. This is primarily due to the assumption of the Gaussian distribution, which can lead to the generation of confidence intervals with negative values. Analyzing the estimated copula models, we observed a prevalence of the bivariate Normal copula, indicating that linear dynamic dependence is frequent, and the Rotated Gumbel 180°, which exhibits lower tail dependence. Overall, the temporal dynamics are predominantly shaped by combining these two types of effects. In point forecasting, both models show similar behavior in the estimation set, with slight advantages for the copula model. The copula model performs better during the out-of-sample analysis, particularly for certain power plants. In interval forecasting, the copula model exhibits pronounced superiority, offering a better estimation of quantiles. Consistently demonstrating proficiency in constructing reliable and accurate intervals, the copula model reveals a notable advantage over the PAR(p) model in interval forecasting.
Assuntos
Monitoramento Ambiental , Previsões , Brasil , Monitoramento Ambiental/métodos , Rios/química , Movimentos da Água , Dinâmica não LinearRESUMO
ABSTRACT A fortuitous observation of mate-guarding behavior of male Chrysoprasis a. auriventris is presented here. In our observation, a male hold onto the female's body using his forelegs and walks along with her while she lays the eggs into the trunk slits. While guarding the female, the male adopted aggressive postures and attacked rival males that approached her. We suggest that the mate-guarding behavior may explain the male's elongated mid and hindlegs in this species, under a functional perspective. Additionally, a new host plant association was recorded.
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This observation analyzes reproductive habots of Eunectes murinus, viviparous snake endemic os South America, with wide distribution in Brazil. One of its most flashy characteristics consists in its giant size and marked sexual dimorphism, important adaptive advantage of the species. Although it is not considered threatened with extinction, contemplative analysis are scarce (among other reasons) due to its semi aquatics routine. Its reproductive habits involve copulation between a female individual and one or more males, wich compete for days in order to perpetuate their genes. the females often cannibalize males and neonates, probably due to the long fasting period they pass through during the breeding season Parthenogenesis was also reported in the species, highlighted by genetic evidence. In this study, social media data has been classified and analyzed from different parameters (localization, environment, time of the year, number of animals and behavior), evidencing literature findings and instigating the realization of new behavioral studies in the field or ex situ.
A presente observação analisa hábtos reprodutivos de Eunectes murinus serpente vivípara endêmica da America do Sul, com ampla distribuição no Brasil. Uma de suas mais chamativas consiste em seu porte gigante e acentuado dimorfismo sexual, importante vatagem adaptativa da espécie. Apesae de não ser considerada ameaçada de extinção, análises contemplativas são escassas devido (dente outras razões) à sua torina semiaquática. Seus hábitos reprodutivos envolvem cópulas entre um indivíduo fêmea e um ou mais machos, os quais competem durante dia a fim de perpetuar seus genes. As fêmeas frequentemente realizam canibalismo de machos e neonatos, provavelmente devido ao longo período de jejum pelo qual passam durante a estação reprodutiva. A partenogênese também foi relatada na espécie, sendo evidenciada por comprovações genéticas. Neste trabalho, dados de redes sociais foram analisadas e classificadas a partir de diferentes parâmetros (localização, ambiente, época do ano, número de animais e comportamento), evidenciando os achados de literatura e instigado a realização de novos estudos de comportamento no campo ou ex situ.
RESUMO
In several species, mating reduces the estrous length and advances ovulation. The aim of this study was to determine if multiple matings reduces the estrous length and modifies the moment of ovulation, as well as the estradiol and LH patterns in ewes. The estrous cycle of Corriedale ewes was synchronized, and the onset of receptivity was monitored every 3 h with rams, avoiding mating. At the estrous onset, ewes were assigned to two experimental groups (n=10 each): 1) estrous was monitored every 3 h with a ram avoiding mating (group CON), and 2) a ram was allowed to mate and ejaculate once every 3 h (group MAT). The ovaries were scanned with transrectal ultrasonography and blood samples were collected for measuring 17ß-estradiol and LH concentrations every 3 h until ovulation. Estrus was shorter in MAT than CON ewes (24.7 ± 1.5 h vs. 30.4 ± 1.5 h, respectively; P=0.02); the proportion of animals that ovulated before the end of estrus was greater in CON ewes: (9/10 vs. 3/10, P=0.009). The area under the LH curve (AUC) was greater in MAT than CON ewes (36.1 ± 3.5 ng.h-1.mL-1 vs 24.9 ± 3.5 ng.h-1.mL-1 P=0.03). However, MAT ewes had a lower 17ß-estradiol AUC than CON ewes (41.0 ± 4.9 pg.h-1.mL-1 vs 59.4 ± 4.9 pg.h-1.mL-1 P=0.01). Mating reduced the estrous length, induced a greater secretion of LH but less total 17ß-estradiol secreted and, additionally, ovulation occurred more frequently after the end of estrus in mated ewes.
RESUMO
Because intrauterine environment differs between twins and singletons, twin-born lambs are often studied when effects of fetal programming are evaluated. In sheep, fetal programming might have effects on reproductive physiology and behavior after sexual maturation. The aim of this study was to compare sperm output and sexual behavior in developing singleton- or twin-born lambs of similar body weight. Singleton lambs (n = 12) and twin (n = 9) male-male lambs were used. From 5.4 until 9.1 months of age, body weight, scrotal circumference (every 3-4 weeks), sexual behavior (every 14 days) and semen characteristics (every 28 days) were evaluated. In the third ejaculate, singleton lambs ejaculated a larger volume of semen than twins (P = 0.03). Considering a pool of the three ejaculates, twin lambs ejaculated semen with a greater sperm concentration than singleton lambs (P = 0.015). There was an interaction between group and time to the onset of courtship behavior (P = 0.02) and a tendency for an interaction in the number of mount attempts (P = 0.052). Singleton-born lambs, during the first evaluation period began courtship behavior earlier than twin-born lambs (P < 0.0001). In conclusion, there were only slight differences in semen and sexual behavior between male ram lambs born as singletons or twins with similar weight. Male ram lambs born as singletons initiated the courtship behavior earlier than twins during the first sexual behavioral evaluation period, ejaculated a larger volume of semen in the third consecutive ejaculate, and there was a lesser sperm concentration in the three ejaculates.
Assuntos
Peso ao Nascer/fisiologia , Gravidez Múltipla , Sêmen/fisiologia , Comportamento Sexual Animal , Maturidade Sexual/fisiologia , Ovinos/fisiologia , Animais , Feminino , Masculino , GravidezRESUMO
In this article we extend the factor copula model to deal with right-censored event time data grouped in clusters. The new methodology allows for clusters to have variable sizes ranging from small to large and intracluster dependence to be flexibly modeled by any parametric family of bivariate copulas, thus encompassing a wide range of dependence structures. Incorporation of covariates (possibly time dependent) in the margins is also supported. Three estimation procedures are proposed: both one- and two-stage parametric and a two-stage semiparametric method where marginal survival functions are estimated by using a Cox proportional hazards model. We prove that the estimators are consistent and asymptotically normally distributed, and assess their finite sample behavior with simulation studies. Furthermore, we illustrate the proposed methods on a data set containing the time to first insemination after calving in dairy cattle clustered in herds of different sizes.
Assuntos
Projetos de Pesquisa , Simulação por Computador , Modelos de Riscos ProporcionaisRESUMO
From molecular mechanisms to global brain networks, atypical fluctuations are the hallmark of neurodegeneration. Yet, traditional fMRI research on resting-state networks (RSNs) has favored static and average connectivity methods, which by overlooking the fluctuation dynamics triggered by neurodegeneration, have yielded inconsistent results. The present multicenter study introduces a data-driven machine learning pipeline based on dynamic connectivity fluctuation analysis (DCFA) on RS-fMRI data from 300 participants belonging to three groups: behavioral variant frontotemporal dementia (bvFTD) patients, Alzheimer's disease (AD) patients, and healthy controls. We considered non-linear oscillatory patterns across combined and individual resting-state networks (RSNs), namely: the salience network (SN), mostly affected in bvFTD; the default mode network (DMN), mostly affected in AD; the executive network (EN), partially compromised in both conditions; the motor network (MN); and the visual network (VN). These RSNs were entered as features for dementia classification using a recent robust machine learning approach (a Bayesian hyperparameter tuned Gradient Boosting Machines (GBM) algorithm), across four independent datasets with different MR scanners and recording parameters. The machine learning classification accuracy analysis revealed a systematic and unique tailored architecture of RSN disruption. The classification accuracy ranking showed that the most affected networks for bvFTD were the SN + EN network pair (mean accuracy = 86.43%, AUC = 0.91, sensitivity = 86.45%, specificity = 87.54%); for AD, the DMN + EN network pair (mean accuracy = 86.63%, AUC = 0.89, sensitivity = 88.37%, specificity = 84.62%); and for the bvFTD vs. AD classification, the DMN + SN network pair (mean accuracy = 82.67%, AUC = 0.86, sensitivity = 81.27%, specificity = 83.01%). Moreover, the DFCA classification systematically outperformed canonical connectivity approaches (including both static and linear dynamic connectivity). Our findings suggest that non-linear dynamical fluctuations surpass two traditional seed-based functional connectivity approaches and provide a pathophysiological characterization of global brain networks in neurodegenerative conditions (AD and bvFTD) across multicenter data.
Assuntos
Doença de Alzheimer/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Conectoma , Função Executiva , Demência Frontotemporal/diagnóstico por imagem , Vias Neurais/diagnóstico por imagem , Idoso , Doença de Alzheimer/fisiopatologia , Teorema de Bayes , Encéfalo/fisiopatologia , Estudos de Casos e Controles , Rede de Modo Padrão/diagnóstico por imagem , Rede de Modo Padrão/fisiopatologia , Vias Eferentes/diagnóstico por imagem , Vias Eferentes/fisiopatologia , Feminino , Demência Frontotemporal/fisiopatologia , Neuroimagem Funcional , Humanos , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiopatologia , Vias Visuais/diagnóstico por imagem , Vias Visuais/fisiopatologiaRESUMO
Abstract In several species, mating reduces the estrous length and advances ovulation. The aim of this study was to determine if multiple matings reduces the estrous length and modifies the moment of ovulation, as well as the estradiol and LH patterns in ewes. The estrous cycle of Corriedale ewes was synchronized, and the onset of receptivity was monitored every 3 h with rams, avoiding mating. At the estrous onset, ewes were assigned to two experimental groups (n=10 each): 1) estrous was monitored every 3 h with a ram avoiding mating (group CON), and 2) a ram was allowed to mate and ejaculate once every 3 h (group MAT). The ovaries were scanned with transrectal ultrasonography and blood samples were collected for measuring 17β-estradiol and LH concentrations every 3 h until ovulation. Estrus was shorter in MAT than CON ewes (24.7 ± 1.5 h vs. 30.4 ± 1.5 h, respectively; P=0.02); the proportion of animals that ovulated before the end of estrus was greater in CON ewes: (9/10 vs. 3/10, P=0.009). The area under the LH curve (AUC) was greater in MAT than CON ewes (36.1 ± 3.5 ng.h-1.mL-1 vs 24.9 ± 3.5 ng.h-1.mL-1 P=0.03). However, MAT ewes had a lower 17β-estradiol AUC than CON ewes (41.0 ± 4.9 pg.h-1.mL-1 vs 59.4 ± 4.9 pg.h-1.mL-1 P=0.01). Mating reduced the estrous length, induced a greater secretion of LH but less total 17β-estradiol secreted and, additionally, ovulation occurred more frequently after the end of estrus in mated ewes.
RESUMO
In several species, mating reduces the estrous length and advances ovulation. The aim of this study was to determine if multiple matings reduces the estrous length and modifies the moment of ovulation, as well as the estradiol and LH patterns in ewes. The estrous cycle of Corriedale ewes was synchronized, and the onset of receptivity was monitored every 3 h with rams, avoiding mating. At the estrous onset, ewes were assigned to two experimental groups (n=10 each): 1) estrous was monitored every 3 h with a ram avoiding mating (group CON), and 2) a ram was allowed to mate and ejaculate once every 3 h (group MAT). The ovaries were scanned with transrectal ultrasonography and blood samples were collected for measuring 17β-estradiol and LH concentrations every 3 h until ovulation. Estrus was shorter in MAT than CON ewes (24.7 ± 1.5 h vs. 30.4 ± 1.5 h, respectively; P=0.02); the proportion of animals that ovulated before the end of estrus was greater in CON ewes: (9/10 vs. 3/10, P=0.009). The area under the LH curve (AUC) was greater in MAT than CON ewes (36.1 ± 3.5 ng.h-1.mL-1 vs 24.9 ± 3.5 ng.h-1.mL-1 P=0.03). However, MAT ewes had a lower 17β-estradiol AUC than CON ewes (41.0 ± 4.9 pg.h-1.mL-1 vs 59.4 ± 4.9 pg.h-1.mL-1 P=0.01). Mating reduced the estrous length, induced a greater secretion of LH but less total 17β-estradiol secreted and, additionally, ovulation occurred more frequently after the end of estrus in mated ewes.(AU)
Assuntos
Animais , Feminino , Ovinos/embriologia , Estro , Ovulação , Estradiol , Hormônio Luteinizante , PrenhezRESUMO
The function of the genital and anal papillae for insemination in Compsura heterura is discussed based on the description of their morphologies at different stages of the life cycle and during copulation and spawning. In males and females both the genital and anal papillae are involved in copulation in C. heterura. A pre-anal organ, anterior to the anus and stretched posteriorly, is present in adult males. The openings of the urinary channel and oviduct are separate in females. During copulation, there is an approximation between the female genital and anal papillae which become temporarily juxtaposed, forming a chamber enclosing the opening of the oviduct, which may also function in sperm capture. During spawning, the lateral edges of the female genital papilla are projected anteriorly, acquiring a tubular shape for oviposition.(AU)
A função das papilas genital e anal na inseminação em Compsura heterura é discutida com base na descrição de suas morfologias em diferentes estágios do ciclo de vida e por ocasião da cópula e desova. Em machos e fêmeas, as papilas genital e anal estão envolvidas na cópula. Um órgão pré-anal, anterior ao ânus e alongado posteriormente, está presente em machos adultos. Fêmeas possuem aberturas urinária e genital separadas. Durante a cópula, ocorre uma aproximação entre as papilas genital e anal femininas, que se justapõem temporariamente, formando uma câmara fechada onde se abre o oviduto, e que serve possivelmente à captura de esperma. Durante a desova, as bordas laterais da papila genital feminina são projetadas anteriormente, adquirindo um formato tubular para ovoposição.(AU)
Assuntos
Animais , Characidae , Inseminação , Estágios do Ciclo de Vida , OviposiçãoRESUMO
The function of the genital and anal papillae for insemination in Compsura heterura is discussed based on the description of their morphologies at different stages of the life cycle and during copulation and spawning. In males and females both the genital and anal papillae are involved in copulation in C. heterura. A pre-anal organ, anterior to the anus and stretched posteriorly, is present in adult males. The openings of the urinary channel and oviduct are separate in females. During copulation, there is an approximation between the female genital and anal papillae which become temporarily juxtaposed, forming a chamber enclosing the opening of the oviduct, which may also function in sperm capture. During spawning, the lateral edges of the female genital papilla are projected anteriorly, acquiring a tubular shape for oviposition.(AU)
A função das papilas genital e anal na inseminação em Compsura heterura é discutida com base na descrição de suas morfologias em diferentes estágios do ciclo de vida e por ocasião da cópula e desova. Em machos e fêmeas, as papilas genital e anal estão envolvidas na cópula. Um órgão pré-anal, anterior ao ânus e alongado posteriormente, está presente em machos adultos. Fêmeas possuem aberturas urinária e genital separadas. Durante a cópula, ocorre uma aproximação entre as papilas genital e anal femininas, que se justapõem temporariamente, formando uma câmara fechada onde se abre o oviduto, e que serve possivelmente à captura de esperma. Durante a desova, as bordas laterais da papila genital feminina são projetadas anteriormente, adquirindo um formato tubular para ovoposição.(AU)
Assuntos
Animais , Characidae , Inseminação , Estágios do Ciclo de Vida , OviposiçãoRESUMO
Spatial predictions of drift deposits on soil surface were conducted using eight different spatial interpolation methods i.e. classical approaches like the Thiessen method and kriging, and some advanced methods like spatial vine copulas, Karhunen-Loève expansion and INLA. In order to investigate the impact of the number of locations on the prediction, all spatial predictions were conducted using a set of 39 and 47 locations respectively. The analysis revealed that taking more locations into account increases the accuracy of the prediction and the extreme behavior of the data is better modeled. Leave-one-out cross-validation was used to assess the accuracy of the prediction. The Thiessen method has the highest prediction errors among all tested methods. Linear interpolation methods were able to better reproduce the extreme behavior at the first meters from the sprayed border and exhibited lower prediction errors as the number of data points increased. Especially the spatial copula method exhibited an obvious increase in prediction accuracy. The Karhunen-Loève expansion provided similar results as universal kriging and IDW, although showing a stronger change in the prediction as the number of locations increased. INLA predicted the pesticide dispersion to be smooth over the whole study area. Using Delaunay triangulation of the study area, the total pesticide concentration was estimated to be between 2.06% and 2.97% of the total Uranine applied. This work is a first attempt to completely understand and model the uncertainties of the mass balance, therefore providing a basis for future studies.
Assuntos
Poluentes Atmosféricos/análise , Praguicidas/análise , Poluentes do Solo/análise , Solo/química , Colômbia , Monitoramento Ambiental/métodos , Modelos Teóricos , Análise EspacialRESUMO
The Snapping turtle (Chelydra serpentina), an exotic species that occurs in North America, is one of the most aquatic species among freshwater turtles. They spend most of their lives deep in lakes or buried in mud in shallow water with only their eyes and nostrils exposed. They can measure up to 47 centimeters and weigh more than 34 kg, have large head and eyes arranged dorso laterally on the back. Large and powerful jaws, the lower jaws are straight and the upper jaws hooked with short snout, so due to its aggressiveness it is known as Snapping turtle. They are most active during the warmer months, but were seen active in winter. Most go into hibernation at the end of October: they bury themselves in the mud under logs, burrows, rocks or plant debris. When they hibernate, they do not breathe, they make gas exchange across the membranes of the mouth and throat, which is known as extrapulmonary respiration. To compare substrate preference and habitat use among semi-extensively captive Chelydra specimens to see if they behave similarly or, if they vary from one specimen to another, observing whether there is a preference for a particular substrate in the open environment as well as the interaction between individuals. For the proposed study, we used five specimens kept in the semi extensive vivarium of turtles and lizards that were displaced to the Reptário, a public exhibition area still under maintenance, where pilot tests for animal release are performed.The specimens are transported in the institution's electric cart, in containment boxes and released in an area with availability of water, sand, grass and stone. The animals were free to choose the substrate. The observations occurred in two moments: the first in the vivarium where they were observed in their own boxes with water and vegetation and the second in the Reptário, both in the morning and afternoon, with several variables for being in an open environment. Random pairs were observed in order to see beyond preference, substrate use and interaction between individuals. Observations in the Biotério and the Reptário showed that sunlight is essential, they became extremely active with heat, especially when temperatures ranged from 20oC to 34oC, but always looked for a place to bury and they move around more into the water. Observations in the Reptário prove that they are really fond of water during all the periods.
A tartaruga mordedora (Chelydra serpentina), uma espécie exótica que ocorre na América do Norte, é uma das espécies mais aquáticas dentre as tartarugas de água doce. Passam a maior parte de sua vida no fundo de lagos ou enterradas na lama em águas rasas, apenas com seus olhos e narinas expostas. Podem medir até 47 centímetros e pesar mais de 34 quilos, possuem cabeça grande e olhos dispostos dorso lateralmente. Mandíbulas grandes e poderosas, as inferiores são retas e as superiores enganchadas com focinho curto, por isso, devido a sua agressividade é conhecida como tartaruga mordedora (Snapping turtle). São mais ativas durante os meses mais quentes, mas já foram vistas ativas no inverno. A maioria entra em hibernação no fim de outubro, se enterram na lama, embaixo de troncos, tocas, pedras ou detritos vegetais. Essas tartarugas quando hibernam não respiram, elas fazem trocas gasosas através das membranas da boca e da garganta, o que é conhecido como respiração extrapulmonar. Este estudo compara a preferência de substratos e o uso de habitat entre os espécimes de Chelydra em cativeiro semiextensivo, para observar se elas têm comportamentos parecidos, ou, se varia de um espécime para outro, observando se há preferência por um determinado substrato em ambiente aberto, além da interação entre os indivíduos. Para o estudo proposto, utilizamos cinco espécimes mantidos no biotério semiextensivo de quelônios e lagartos que foram deslocados ao Reptário, área de exposição pública ainda em manutenção, onde são realizados testes piloto de soltura de animais. Os espécimes são transportados em carrinho elétrico da instituição, em caixas de contenção e soltos em uma área com disponibilidade de água, areia, grama e pedra. Os animais ficaram à vontade para escolha do substrato. As observações ocorreram em dois momentos: o primeiro no biotério onde eram observadas em suas próprias caixas com água e vegetação e o segundo no Reptário, ambos no período da manhã e tarde, com diversas variáveis por ser em ambiente aberto. Foram observadas duplas aleatórias a fim de ver além da preferência, o uso dos substratos e a interação entre os indivíduos. As observações no Biotério e no Reptário constatam que a luz solar é essencial, elas ficavam extremamente ativas com o calor, pincipalmente quando a temperatura varia de 20oC a 34oC, mas sempre procuravam um local para se enterrar e se movimentavam mais dentro da água. As observações no Reptário comprovam que elas têm realmente predileção por água em qualquer temperatura e clima.
RESUMO
Os distúrbios ejaculatórios em garanhões são caracterizados como o não desencadeamento da ejaculação mesmo quando todos os demais parâmetros relacionados ao comportamento sexual apresentam-se normais. Os principais distúrbios ejaculatórios estão subdivididos em: não ejaculação, ejaculação prematura, ejaculação incompleta e urospermia. O tratamento é dependente da causa primária de cada alteração, desse modo, é fundamental uma avaliação criteriosa do garanhão no momento da colheita de sêmen, observando se existem sinais de desconforto, dor ou medo. Ao efetuar a monta o garanhão deposita todo o peso corporal nos membros posteriores, de modo que qualquer alteração dolorosa nesses membros se tornam muito mais intensas nesse momento e podem afetar a libido após sucessivas tentativas frustradas. É importante observar também se durante a monta o garanhão realiza os movimentos característicos de propulsão e de ejaculação para se realizar um diagnóstico diferencial entre falha ejaculatória e obstruções do aparelho reprodutor. O objetivo desta revisão é informar aos leitores das principais causas de distúrbios ejaculatórios e quais os melhores métodos de diagnóstico.(AU)
The ejaculatory disorders in stallions are characterized as the non-triggering of ejaculation even when sexual behavior seems normal. The main ejaculatory disorders are subdivided into: no ejaculation, premature ejaculation, incomplete ejaculation and urospermia. Treatment depends on the primary cause of each disorder, so a careful evaluation of the stallion at the time of semen collection is essential, noting if there are signs of discomfort, pain or fear. During breeding the stallion deposits all body weight on the hind limbs, so that any painful changes in these limbs become more intense at this time and can affect the libido after successive failed attempts. It is also important to observe if during mounts the stallion performs the characteristic movements of thrusting and ejaculation to perform a differential diagnosis between ejaculatory failure and obstructions of the reproductive system. The purpose of this review is to inform readers of the main causes of ejaculatory disorders and which are the more useful diagnostic methods.(AU)
Los disturbios eyaculatorios en sementales se caracterizan como el no desencadenamiento de la eyaculación incluso cuando todos los demás parámetros relacionados con el comportamiento sexual se presentan normales. Los principales trastornos eyaculatorios están subdivididos en: no eyaculación, eyaculación prematura, eyaculación incompleta y urospermia. El tratamiento es dependiente de la causa primaria de cada alteración, por lo que es fundamental una evaluación cuidadosa del semental en el momento de la cosecha de semen, observando si existen signos de incomodidad, dolor o miedo. Al efectuar la monta el semental deposita todo el peso corporal en los miembros posteriores, de modo que cualquier alteración dolorosa en esos miembros se vuelve mucho más intenso en ese momento y pueden afectar la libido después de sucesivos intentos frustrados. Es importante observar también si durante la monta el semental realiza los movimientos característicos de propulsión y de eyaculación para realizar un diagnóstico diferencial entre fallo eyaculatorio y obstrucciones del aparato reproductor. El objetivo de esta revisión es informar a los lectores de las principales causas de disturbios eyaculatorios y cuáles son los mejores métodos de diagnóstico.(AU)
Assuntos
Animais , Masculino , Cavalos/anormalidades , Cavalos/fisiologia , Ejaculação/fisiologia , Comportamento Sexual Animal/fisiologia , Ereção Peniana/fisiologia , Reprodução/fisiologiaRESUMO
Os distúrbios ejaculatórios em garanhões são caracterizados como o não desencadeamento da ejaculação mesmo quando todos os demais parâmetros relacionados ao comportamento sexual apresentam-se normais. Os principais distúrbios ejaculatórios estão subdivididos em: não ejaculação, ejaculação prematura, ejaculação incompleta e urospermia. O tratamento é dependente da causa primária de cada alteração, desse modo, é fundamental uma avaliação criteriosa do garanhão no momento da colheita de sêmen, observando se existem sinais de desconforto, dor ou medo. Ao efetuar a monta o garanhão deposita todo o peso corporal nos membros posteriores, de modo que qualquer alteração dolorosa nesses membros se tornam muito mais intensas nesse momento e podem afetar a libido após sucessivas tentativas frustradas. É importante observar também se durante a monta o garanhão realiza os movimentos característicos de propulsão e de ejaculação para se realizar um diagnóstico diferencial entre falha ejaculatória e obstruções do aparelho reprodutor. O objetivo desta revisão é informar aos leitores das principais causas de distúrbios ejaculatórios e quais os melhores métodos de diagnóstico.
The ejaculatory disorders in stallions are characterized as the non-triggering of ejaculation even when sexual behavior seems normal. The main ejaculatory disorders are subdivided into: no ejaculation, premature ejaculation, incomplete ejaculation and urospermia. Treatment depends on the primary cause of each disorder, so a careful evaluation of the stallion at the time of semen collection is essential, noting if there are signs of discomfort, pain or fear. During breeding the stallion deposits all body weight on the hind limbs, so that any painful changes in these limbs become more intense at this time and can affect the libido after successive failed attempts. It is also important to observe if during mounts the stallion performs the characteristic movements of thrusting and ejaculation to perform a differential diagnosis between ejaculatory failure and obstructions of the reproductive system. The purpose of this review is to inform readers of the main causes of ejaculatory disorders and which are the more useful diagnostic methods.
Los disturbios eyaculatorios en sementales se caracterizan como el no desencadenamiento de la eyaculación incluso cuando todos los demás parámetros relacionados con el comportamiento sexual se presentan normales. Los principales trastornos eyaculatorios están subdivididos en: no eyaculación, eyaculación prematura, eyaculación incompleta y urospermia. El tratamiento es dependiente de la causa primaria de cada alteración, por lo que es fundamental una evaluación cuidadosa del semental en el momento de la cosecha de semen, observando si existen signos de incomodidad, dolor o miedo. Al efectuar la monta el semental deposita todo el peso corporal en los miembros posteriores, de modo que cualquier alteración dolorosa en esos miembros se vuelve mucho más intenso en ese momento y pueden afectar la libido después de sucesivos intentos frustrados. Es importante observar también si durante la monta el semental realiza los movimientos característicos de propulsión y de eyaculación para realizar un diagnóstico diferencial entre fallo eyaculatorio y obstrucciones del aparato reproductor. El objetivo de esta revisión es informar a los lectores de las principales causas de disturbios eyaculatorios y cuáles son los mejores métodos de diagnóstico.
Assuntos
Masculino , Animais , Cavalos/anormalidades , Cavalos/fisiologia , Comportamento Sexual Animal/fisiologia , Ejaculação/fisiologia , Ereção Peniana/fisiologia , Reprodução/fisiologiaRESUMO
In this paper, we study the performance of Bayesian computational methods to estimate the parameters of a bivariate survival model based on the Ali-Mikhail-Haq copula with marginal distributions given by Weibull distributions. The estimation procedure was based on Monte Carlo Markov Chain (MCMC) algorithms. We present three version of the Metropolis-Hastings algorithm: Independent Metropolis-Hastings (IMH), Random Walk Metropolis (RWM) and Metropolis-Hastings with a natural-candidate generating density (MH). Since the creation of a good candidate generating density in IMH and RWM may be difficult, we also describe how to update a parameter of interest using the slice sampling (SS) method. A simulation study was carried out to compare the performances of the IMH, RWM and SS. A comparison was made using the sample root mean square error as an indicator of performance. Results obtained from the simulations show that the SS algorithm is an effective alternative to the IMH and RWM methods when simulating values from the posterior distribution, especially for small sample sizes. We also applied these methods to a real data set.
RESUMO
Measuring the dependence between random variables is one of the most fundamental problems in statistics, and therefore, determining the joint distribution of the relevant variables is crucial. Copulas have recently become an important tool for properly inferring the joint distribution of the variables of interest. Although many studies have addressed the case of continuous variables, few studies have focused on treating discrete variables. This paper presents a nonparametric approach to the estimation of joint discrete distributions with bounded support using copulas and Bernstein polynomials. We present an application in real obsessive-compulsive disorder data.
RESUMO
Generic drugs have been commercialized in numerous countries. Most of these countries approve the commercialization of a generic drug when there is evidence of bioequivalence between the generic drug and the reference drug. Generally, the pharmaceutical industry is responsible for the bioequivalence test under the supervision of a regulatory agency. This procedure is concluded after a statistical data analysis. Several agencies adopt a standard statistical analysis based on procedures that were previously established. In practice, we face situations in which this standard model does not fit to some sets of bioequivalence data. In this study, we propose an evaluation of bioequivalence using univariate and bivariate models based on an extended generalized gamma distribution and a skew-t distribution, under a Bayesian perspective. We introduce a study of the empirical power of hypothesis tests for univariate models, showing advantages in the use of an extended generalized gamma distribution. Three sets of bioequivalence data were analyzed under these new procedures and compared with the standard model proposed by the majority of regulatory agencies. In order to verify that the asymmetrical distributions are usually better fitted for the data, when compared with the standard model, model discrimination methods were used, such as the Deviance Information Criterion (DIC) and quantile-quantile plots. The research concluded that, in general, the use of the extended generalized gamma distribution may be more appropriate to model bioequivalence data in the original scale. Copyright © 2016 John Wiley & Sons, Ltd.
Assuntos
Teorema de Bayes , Medicamentos Genéricos , Equivalência Terapêutica , Interpretação Estatística de Dados , Humanos , Distribuições EstatísticasRESUMO
São apresentados dois casos de desvio peniano ventral em cães. No Caso 1, um Poodle de quatro anosde idade com adequada libido, mas incapacidade de cópula devido a desvio ventral do pênis, cuja coleta desêmen foi realizada e inseminadas artificialmente quatro cadelas. No Caso 2, um Dachshund de um ano e meiode idade com adequada libido, mas desvio ventral do pênis, submetido à coleta de sêmen para espermiograma.Este cão foi capaz de copular uma mesma cadela em dois estros distintos. Ao exame radiográfico do cão do Caso2, foi identificada inflexão ventral do osso peniano de 30º, sem sinais agudos ou crônicos de fratura. Em nenhumdos casos havia outras alterações genitais e urinárias concomitantes. Conclui-se pela variável capacidade decópula e possibilidade de coleta de sêmen para inseminação artificial nestes cães.(AU)
Two cases of ventral penile deviation in dogs are presented. In Case 1, a four years old Poodle withadequate libido but disability of copulation because of ventral penile deviation, whose semen collection wassuccessfully achieved and four bitches artificially inseminated. In Case 2, a one and a half years old Dachshundwith adequate libido but ventral penile deviation, who had semen collected for spermogram. This dog was ableto copulate one bitch in two different heats. At the radiographic examination of the Case 2 dog, it was identifieda ventral penile bone inflection of 30º, without acute or chronic signs of fracture. In none of the cases otherconcomitant genital and urinary abnormalities was observed. The results showed the variable copulationcapacity and the possibility of semen collection for artificial insemination of these dogs.(AU)
Assuntos
Animais , Masculino , Feminino , Cães , Cães/anatomia & histologia , Cães/embriologia , Cães/genética , Inseminação Artificial , Inseminação Artificial/veterinária , SêmenRESUMO
São apresentados dois casos de desvio peniano ventral em cães. No Caso 1, um Poodle de quatro anosde idade com adequada libido, mas incapacidade de cópula devido a desvio ventral do pênis, cuja coleta desêmen foi realizada e inseminadas artificialmente quatro cadelas. No Caso 2, um Dachshund de um ano e meiode idade com adequada libido, mas desvio ventral do pênis, submetido à coleta de sêmen para espermiograma.Este cão foi capaz de copular uma mesma cadela em dois estros distintos. Ao exame radiográfico do cão do Caso2, foi identificada inflexão ventral do osso peniano de 30º, sem sinais agudos ou crônicos de fratura. Em nenhumdos casos havia outras alterações genitais e urinárias concomitantes. Conclui-se pela variável capacidade decópula e possibilidade de coleta de sêmen para inseminação artificial nestes cães.
Two cases of ventral penile deviation in dogs are presented. In Case 1, a four years old Poodle withadequate libido but disability of copulation because of ventral penile deviation, whose semen collection wassuccessfully achieved and four bitches artificially inseminated. In Case 2, a one and a half years old Dachshundwith adequate libido but ventral penile deviation, who had semen collected for spermogram. This dog was ableto copulate one bitch in two different heats. At the radiographic examination of the Case 2 dog, it was identifieda ventral penile bone inflection of 30º, without acute or chronic signs of fracture. In none of the cases otherconcomitant genital and urinary abnormalities was observed. The results showed the variable copulationcapacity and the possibility of semen collection for artificial insemination of these dogs.