40 research outputs found

    Sexual Dimorphism in Red-Eared Sliders (Trachemys scripta elegans) from the Wild Animal Triage Center of the Tiete Ecological Park, SĂŁo Paulo, Brazil

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    Background: Trachemys scripta elegans is an aquatic turtle native to North America and distributed geographically from the eastern United States to northeastern Mexico. In Brazil, it is an exotic and invasive species and the most illegally traded pet animal. When these turtles grow and they cease to be attractive as pets, they are released clandestinely in lakes, ponds, rivers, and other bodies of water, where they threaten biodiversity and native populations. The present study aimed to characterize specimens of T. s. elegans from the Centro de Triagem de Animais Silvestres do Parque EcolĂłgico do Tiete by analyzing body biometrics, sexual dimorphism, and structure of specimens for sex ratio and size classes.Materials, Methods & Results: Trachemys scripta elegans turtles (39 females and 30 males) were anesthetized, euthanized and frozen. After being thawed, the turtles were sexed according to measurements on secondary sex characters such as claw length (CWL) of the third finger of the right forearm and length of the tail from the tip to the beginning of the cloacal opening (postcloacal tail length, PTL); subsequently, sex was confirmed through dissection. Subsequently, body mass (BM, g) and maximum carapace length (MCL, cm), maximum carapace width (MCW, cm), maximum plastron length (MPL, cm), maximum plastron width (MPW) and shell height (HGT, cm, measured laterally until obtaining the greatest value) were evaluated and the sexual dimorphism index (SDI) was also calculated. All analyses were performed using SAS v. 9.4 software. The results indicate a sex ratio of 1.3 females per male. The identification of males by secondary sex characteristics was performed using only claw length (CWL), which was related to sex and not to maximum carapace length (MCL). The most discriminatory variables were CWL in males and body mass (BM) in females. With the exception of CWL, the sexual dimorphism index (SDI) values all favored females and varied from 1.21 to 2.49, with the greatest value for BM and the lowest value for postcloacal tail length (PTL). Males exhibited a unimodal tendency at a classification interval of 15.0 cm MCL, and females exhibited a bimodal tendency at 21.0- and 22.0 cm MCL. Sexual maturity was identified at 12.0 cm MCL in males and at 12.5 cm MCL in females. The rate of CWL growth in males was higher at the beginning of sexual maturity and subsequently decreased, whereas in females, the rate of CWL escalated after 19.0 cm MCL. In both sexes, principal component 1 (PC1) was composed of the variables related to size and BM, and principal component 2 (PC2) and principal component 3 (PC3) were composed of variables related to secondary sex characteristics (CWL and PTL).Discussion: In members of the genus Trachemys, several secondary sex characteristics can be used to differentiate between the sexes, however, in the present study, recognition of males was performed only by claw length, as it was confirmed by the discriminate analysis and the principal components analysis (PCA) which showed that CWL was the variable that was most discriminatory in males (approximately 76.0%), followed by BM (approximately 50%) in females. The results reinforcing the claim that the degree of development of secondary sex characteristics varies between species as well as between distinct populations of the same species and establish that even under unnatural habitat, sexual dimorphism of size in favor of females is maintained for variables related to mass and size

    Análise morfológica e funcional do processo espermatogênico em cobaios (Cavia porcellus) da pré-puberdade até a pós-puberdade

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    Este estudo descreveu as análises morfológica e funcional do processo espermatogênico em cobaios (Cavia porcellus) de cinco (S5); seis (S6); nove (S9) e onze (S11) semanas de idade (N=5/grupo). Os aspectos analisados incluíram a contagem das populações celulares presentes no estádio 1 do ciclo do epitélio seminífero (CES), eficiência das mitoses espermatogoniais (RMi), produção meiótica (RMe), rendimento geral da espermatogênese (RGE), índice de células de Sertoli (ICS) e capacidade de suporte das células de Sertoli (CSCS). Os resultados mostraram que número médio de espermatogônias A, espermatócitos primários em pré-leptóteno/leptóteno, espermatócitos primários em paquíteno, células espermatogênicas totais e células de Sertoli mostraram variações numéricas em função da idade, entretanto, não detectadas estatisticamente, enquanto espermátides arredondadas aumentaram significativamente na puberdade e depois se estabilizaram. A produção espermatogênica de cobaios de 5 a 11 semanas não atingiu o ponto de estabilização e o RMi, RMe, RGE, ICS e CSCS mostraram variação numérica significativa em função da idade. Os resultados demonstraram que Cavia porcellus na pós-puberdade 2 são um modelo experimental vantajoso para estudos de processos de reconhecimento homólogos, alinhamento, e sinapses durante a prófase meiótica; o rendimento intrínseco da espermatogênese em cobaios é semelhante ao relatado para ratos Wistar, pacas e cutias (Dasyprocta sp.) e menor do que em preás, enquanto que a eficiência funcional das células de Sertoli é superior a de cutias e ratos Wistar e inferior à de pacas, rato espinhoso e catetos. Concluiu-se que em cobaios a espermatogênese está completamente estabelecida na semana 6 de idade, indicando a fase púbere do desenvolvimento sexual, e até a semana 11 eles não atingiram a produção espermática diária máxima e, portanto, a maturidade sexual

    Influência do polipirrol e dos níveis de salinidade na formação de biofilme em Aeromonas spp.

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    RESUMO: Bactérias do gênero Aeromonas são patógenos altamente disseminados no ambiente aquático, responsáveis por grandes perdas econômicas na piscicultura de diversos países. São micro-organismos oportunistas e sua patogenicidade está ligada a alguns fatores de virulência, como a formação de biofilme. O estresse salino é um dos fatores que favorecem a formação dessas colônias e, consequentemente, o aumento de infecções. Essas infecções quando estão associadas ao biofilme são ainda mais resistentes aos antimicrobianos. Nesse contexto, o polipirrol destaca-se como uma alternativa antimicrobiana por possuir vários atributos terapêuticos e não apresentar toxicidade aos organismos. Dessa forma, o objetivo desse estudo foi avaliar o perfil de susceptibilidade e a capacidade de formação de biofilme dos isolados de Aeromonas spp. associados aos diferentes níveis de salinidade e polipirrol. Determinou-se a atividade antibacteriana dos isolados e ensaios de motilidade foram realizados com bactérias que carreavam o gene fla. Também verificou-se a capacidade do cloreto de sódio e polipirrol em interferir na formação do biofilme. Os resultados foram evidenciados com a microscopia eletrônica de varredura. As concentrações de 2 e 3% de NaCl inibiram a motilidade bacteriana. Na formação do biofilme, 83% dos isolados bacterianos induziram a produção na concentração de 0,25%. O polipirrol causou a morte de todos os isolados testados na concentração de 125μg/mL. Além disso, esse composto diminuiu a motilidade bacteriana nas concentrações de 0,25 a 3%, sendo que em relação à produção de biofilme, não houve interferência. Esses resultados evidenciam que os diferentes níveis de NaCl influenciam na formação do biofilme favorecendo a persistência da infecção. Este estudo também realçou a potencialidade do polipirrol como agente bactericida, sendo uma alternativa eficaz às drogas antimicrobianas para o tratamento das infecções causadas por Aeromonas spp

    Sexual Dimorphism in Red-Eared Sliders (Trachemys scripta elegans) from the Wild Animal Triage Center of the Tiete Ecological Park, SĂŁo Paulo, Brazil

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    Background: Trachemys scripta elegans is an aquatic turtle native to North America and distributed geographically from the eastern United States to northeastern Mexico. In Brazil, it is an exotic and invasive species and the most illegally traded pet animal. When these turtles grow and they cease to be attractive as pets, they are released clandestinely in lakes, ponds, rivers, and other bodies of water, where they threaten biodiversity and native populations. The present study aimed to characterize specimens of T. s. elegans from the Centro de Triagem de Animais Silvestres do Parque EcolĂłgico do Tiete by analyzing body biometrics, sexual dimorphism, and structure of specimens for sex ratio and size classes.Materials, Methods & Results: Trachemys scripta elegans turtles (39 females and 30 males) were anesthetized, euthanized and frozen. After being thawed, the turtles were sexed according to measurements on secondary sex characters such as claw length (CWL) of the third finger of the right forearm and length of the tail from the tip to the beginning of the cloacal opening (postcloacal tail length, PTL); subsequently, sex was confirmed through dissection. Subsequently, body mass (BM, g) and maximum carapace length (MCL, cm), maximum carapace width (MCW, cm), maximum plastron length (MPL, cm), maximum plastron width (MPW) and shell height (HGT, cm, measured laterally until obtaining the greatest value) were evaluated and the sexual dimorphism index (SDI) was also calculated. All analyses were performed using SAS v. 9.4 software. The results indicate a sex ratio of 1.3 females per male. The identification of males by secondary sex characteristics was performed using only claw length (CWL), which was related to sex and not to maximum carapace length (MCL). The most discriminatory variables were CWL in males and body mass (BM) in females. With the exception of CWL, the sexual dimorphism index (SDI) values all favored females and varied from 1.21 to 2.49, with the greatest value for BM and the lowest value for postcloacal tail length (PTL). Males exhibited a unimodal tendency at a classification interval of 15.0 cm MCL, and females exhibited a bimodal tendency at 21.0- and 22.0 cm MCL. Sexual maturity was identified at 12.0 cm MCL in males and at 12.5 cm MCL in females. The rate of CWL growth in males was higher at the beginning of sexual maturity and subsequently decreased, whereas in females, the rate of CWL escalated after 19.0 cm MCL. In both sexes, principal component 1 (PC1) was composed of the variables related to size and BM, and principal component 2 (PC2) and principal component 3 (PC3) were composed of variables related to secondary sex characteristics (CWL and PTL).Discussion: In members of the genus Trachemys, several secondary sex characteristics can be used to differentiate between the sexes, however, in the present study, recognition of males was performed only by claw length, as it was confirmed by the discriminate analysis and the principal components analysis (PCA) which showed that CWL was the variable that was most discriminatory in males (approximately 76.0%), followed by BM (approximately 50%) in females. The results reinforcing the claim that the degree of development of secondary sex characteristics varies between species as well as between distinct populations of the same species and establish that even under unnatural habitat, sexual dimorphism of size in favor of females is maintained for variables related to mass and size

    Estimation of dairy goat body composition: A direct calibration and comparison of eight methods

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    International audienceThe objective was to compare eight methods for estimation of dairy goat body composition, by calibrating against chemical composition (water, lipid, protein, mineral and energy) measured post-mortem. The methods tested on 20 Alpine goats were body condition score (BCS), 3-dimension imaging (3D) automatic assessment of BCS or whole body scan, ultrasound, computer tomography (CT), adipose cell diameter, deuterium oxide dilution space (D 2 OS) and bioelectrical impedance spectroscopy (BIS). Regressions were tested between predictive variates derived from the methods and empty body (EB) composition. The best equations for estimation of EB lipid mass included BW combined with i) perirenal adipose tissue mass and cell diameter (R 2 = 0.95, residual standard deviation, rSD = 0.57 kg), ii) volume of fatty tissues measured by CT (R 2 = 0.92, rSD = 0.76 kg), iii) D 2 OS (R 2 = 0.91, rSD = 0.85 kg), and iv) resistance at infinite frequency from BIS (R 2 = 0.87, rSD = 1.09 kg). The D 2 OS combined with BW provided the best equation for EB protein mass (R 2 = 0.97, rSD = 0.17 kg), whereas BW alone provided a fair estimate (R 2 = 0.92, rSD = 0.25 kg). Sternal BCS combined with BW provided good estimation of EB lipid and protein mass (R 2 = 0.80 and 0.95, rSD = 1.27 and 0.22 kg, respectively). Compared to manual BCS, BCS by 3D slightly decreased the precision of the predictive equation for EB lipid (R 2 = 0.74, rSD = 1.46 kg), and did not improve the estimation of EB protein compared with BW alone. Ultrasound measurements and whole body 3D imaging methods were not satisfactory estimators of body composition (R 2 ≤ 0.40). Further developments in body composition techniques may contribute for high-throughput phenotyping of robustness

    In vivo estimation of body composition: comparison of eight methods in dairy goats

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    International audienceThe objective was to test 8 methods for estimation of empty body lipid (EBL) and protein (EBP) mass in dairy goats. The methods tested on 20 Alpine goats (3±0.6 years old; 226±9 DIM; 47 to 72 kg of BW) were: adipose cell size; deuterium oxide dilution space (D2OS); 3-dimension (3D) imaging: whole body 3D-scan and automatic 3D assessment of body condition score (3D-BCS); manual sternal and lumbar BCS and ultrasound imagery; computer tomography and bioelectrical impedance spectroscopy (BIS). Simple and multiple regressions (Proc GLM, SAS) were tested between different variables and EBL and EBP mass measured by chemical analyses after slaughter. Perirenal adipose tissue mass and cell diameter combined with BW provided the most accurate predictive equations for EBL (R2=0.95, residual coefficient of variation, rCV=12%). Nonetheless, such predictors can only be measured postmortem. The best equations for EBL derived from in vivo variables included BW combined with 1/ the volume of fatty tissues measured by computer tomography (R2=0.92, rCV=17%), 2/ the D2OS (R2=0.91, rCV=19%), and 3/ the BIS (R2=0.87, rCV=23%). D2OS combined with BW provided the best equation for EBP (R2=0.97, rCV=3%), whereas BW alone provided a fair EBP estimate (R2=0.92, rCV=4%). Manual BCS combined with BW provided good EBL and EBP estimations (R2=0.80 and 0.94, rCV=28 and 4%, respectively). BCS is a non-invasive technique and does not require particular equipment, but it is subjective and prone to operator bias. Compared to manual BCS, 3D-BCS combined with BW slightly decreased the accuracy of the predictive equation for EBL (R2=0.74, rCV=32%), and did not improve the estimation of EBP compared with BW alone. Ultrasound and whole body 3D imaging techniques were not satisfactory estimators of EBL and EBP (R2≤0.40)

    Phénotypage fin de la composition corporelle : calibration et comparaison directe de huit méthodes chez la chèvre laitière

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    International audienceEight methods were compared to estimate dairy goat body composition, by calibrating against chemical composition measured post-mortem. The methods tested on 20 Alpine goats were body condition score (BCS), 3D imaging assessment of BCS or whole body scan, ultrasound, computer tomography (CT), adipose cell diameter, deuterium oxide dilution space (D2OS) and bioelectrical impedance spectroscopy. Regressions were tested between predictive variates and empty body composition. The best equations for estimation of lipid mass included body weight combined with i) perirenal adipose tissue mass and cell diameter (R² = 0.95), ii) volume of fatty tissues measured by CT (R² = 0.92), or iii) D2OS (R² = 0.91). The best equations for estimation of protein mass combined body weight with D2OS (R² = 0.97) or sternal BCS (R² = 0.95). Whole body 3D imaging method and ultrasound measurements were not satisfactory estimators of body composition (R² ≤ 0.40).Huit méthodes ont été comparées pour phénotyper la composition corporelle chez 20 chèvres laitières : la note d’état corporel (NEC), l’imagerie 3D pour estimer la NEC et reconstituer le corps entier, l’échographie, la tomodensitométrie (CT), le diamètre des adipocytes, l’espace de diffusion de l’eau deutérée (EDD2O) et l’impédancemétrie. Les différentes variables issues des méthodes testées ont été incluses dans des régressions linéaires pour déterminer la composition chimique du corps vide mesurée après abattage. Les équations les plus précises pour l’estimation de la masse de lipides combinent le poids vif et i) le poids total et le diamètre des adipocytes du tissu adipeux périrénal (R² = 0,95), ii) le volume des tissus gras mesuré par CT (R² = 0,92) ou iii) l’EDD2O (R² = 0,91). Les meilleures équations d’estimation de la masse de protéines incluent le poids vif et l’EDD2O (R² = 0,97) ou la NEC sternale (R² = 0,95). L’imagerie 3D corps entier et les mesures échographiques ne semblent pas être de bons estimateurs de la composition corporelle (R² ≤ 0.40)

    Relationships between neuropsychological performance, insight, medication adherence, and social metacognition in schizophrenia

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    International audienceBackground: Social metacognition is still poorly understood in schizophrenia, particularly its neuropsychological basis and its impact on insight and medication adherence. We therefore quantified social metacognition as the agreement between objective and subjective mentalization and assessed its correlates in a sample of individuals with schizophrenia spectrum disorders.Methods: Participants consisted of 143 patients with schizophrenia or schizoaffective disorders who underwent a metacognitive version of a mentalization task, an extensive neuropsychological battery, and a clinical evaluation to assess their insight into illness and medication adherence. We studied potential interactions between confidence judgments and several neuropsychological and clinical variables on mentalization accuracy with mixed-effects multiple logistic regressions.Results:Confidence judgments were closely associated with mentalization accuracy, indicative of good social metacognition in this task. Working memory, visual memory, and reasoning and problem-solving were the three neuropsychological dimensions positively associated with metacognition. By contrast, the two measures of medication adherence were associated with poorer metacognition, whereas no association was found between metacognition and clinical insight. The multiple regression model showed a significant positive impact of better working memory, older age at onset, longer duration of hospitalization, and worse medication adherence on social metacognition.Conclusions: We discuss possible mechanisms underlying the apparent association between social metacognition and working memory. Adherence should be monitored when remediating social metacognition, and psychoeducation should be given to patients with a high level of awareness of their capacity to mentalize
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