RESUMO

A common basis to address the dynamics of directly transmitted infectious diseases, such as COVID-19, are compartmental (or SIR) models. SIR models typically assume homogenous population mixing, a simplification that is convenient but unrealistic. Here we validate an existing model of a scale-free fractal infection process using high-resolution data on COVID-19 spread in São Caetano, Brazil. We find that transmission can be described by a network in which each infectious individual has a small number of susceptible contacts, of the order of 2-5. This model parameter correlated tightly with physical distancing measured by mobile phone data, such that in periods of greater distancing the model recovered a lower average number of contacts, and vice versa. We show that the SIR model is a special case of our scale-free fractal process model in which the parameter that reflects population structure is set at unity, indicating homogeneous mixing. Our more general framework better explained the dynamics of COVID-19 in São Caetano, used fewer parameters than a standard SIR model and accounted for geographically localized clusters of disease. Our model requires further validation in other locations and with other directly transmitted infectious agents.

RESUMO

Objetivou-se testar a vitrificação de ovários de camundongos do ICTB/Fiocruz. Inicialmente, fez-se coleta e maturação in vitro dos oócitos de ovários a fresco e vitrificados, bem como avaliação de estruturas no cultivo embrionário, pós-fertilização in vitro. Fêmeas B6D2F1 foram eutanasiadas para remoção dos ovários (n=60) e divididas em três grupos: grupo 1 (n=30 animais) - oócito de ovários vitrificados, maturados e fertilizados in vitro (120 fragmentos); grupo 2 (n=15) (controle 1) - oócitos coletados a fresco, maturados e fertilizados in vitro; e grupo 3 (n=15) (controle 2) - oócitos maturados in vivo e fertilizados in vitro. A técnica foi verificada no desenvolvimento embrionário in vitro, que foi avaliado pelo teste de qui-quadrado (BioStat 5.0). Recuperaram-se 123, 224 e 328 oócitos nos G1, G2 e G3, respectivamente. Observaram-se diferenças significativas nas taxas de clivagem às 24 horas (embriões ≥ 2 células) entre G1 (8%) e G2 (32%) (P<0,1) e G1 e G3 (49%) (P<0,05), mas não entre G2 e G3 (P>0,05). Para blastocistos, às 96 horas, os grupos G1, G2 e G3 apresentaram, respectivamente, 6%, 11% e 46%, diferindo significativamente entre eles (P<0,05). A vitrificação de ovários, a maturação oocitária e a fertilização in vitro são alternativas para a produção de embriões de camundongos in vitro.(AU)

This work aimed test ovarian vitrification of hybrid mouse from ICTB/Fiocruz. Protocol collection and oocyte in vitro maturation from fresh and vitrified ovaries was established and embryos were evaluated after fertilization. B6D2F1 females were euthanized for ovarian removal (n= 60) and divided into 3 groups: G1 (n= 30) - ovaries fragmented (n= 120), vitrified, matured and fertilized; G2 (n= 15) - in vitro fertilization of oocytes matured in vitro from fresh ovaries; G3 (n= 15) - ampulla region oocytes in vitro fertilizated. Viability was verified by thawing, oocyte in vitro maturation and fertilization. In vitro embryo development of each group was evaluated by Chi-square test (BioStat 5.0). 123, 224 and 328 oocytes were recovered from G1, G2 and G3, respectively. Significant differences were observed in cleavage rates at 24 hours (embryos with 2 cells or more) between G1 (8%) and G2 (32%) (P< 0.1) and G1 and G3 (49%) (P< 0.05) but not between G2 and G3 (P> 0.05). Blastocysts at 96 hours presented 6%, 11% and 46%, respectively for G1, G2 and G3, differing significantly (P< 0.05). Ovary vitrification, oocyte in vitro maturation and in vitro fertilization were available for the production of in vitro mouse embryos.(AU)

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RESUMO

Objetivou-se testar a vitrificação de ovários de camundongos do ICTB/Fiocruz. Inicialmente, fez-se coleta e maturação in vitro dos oócitos de ovários a fresco e vitrificados, bem como avaliação de estruturas no cultivo embrionário, pós-fertilização in vitro. Fêmeas B6D2F1 foram eutanasiadas para remoção dos ovários (n=60) e divididas em três grupos: grupo 1 (n=30 animais) - oócito de ovários vitrificados, maturados e fertilizados in vitro (120 fragmentos); grupo 2 (n=15) (controle 1) - oócitos coletados a fresco, maturados e fertilizados in vitro; e grupo 3 (n=15) (controle 2) - oócitos maturados in vivo e fertilizados in vitro. A técnica foi verificada no desenvolvimento embrionário in vitro, que foi avaliado pelo teste de qui-quadrado (BioStat 5.0). Recuperaram-se 123, 224 e 328 oócitos nos G1, G2 e G3, respectivamente. Observaram-se diferenças significativas nas taxas de clivagem às 24 horas (embriões ≥ 2 células) entre G1 (8%) e G2 (32%) (P<0,1) e G1 e G3 (49%) (P<0,05), mas não entre G2 e G3 (P>0,05). Para blastocistos, às 96 horas, os grupos G1, G2 e G3 apresentaram, respectivamente, 6%, 11% e 46%, diferindo significativamente entre eles (P<0,05). A vitrificação de ovários, a maturação oocitária e a fertilização in vitro são alternativas para a produção de embriões de camundongos in vitro.(AU)

This work aimed test ovarian vitrification of hybrid mouse from ICTB/Fiocruz. Protocol collection and oocyte in vitro maturation from fresh and vitrified ovaries was established and embryos were evaluated after fertilization. B6D2F1 females were euthanized for ovarian removal (n= 60) and divided into 3 groups: G1 (n= 30) - ovaries fragmented (n= 120), vitrified, matured and fertilized; G2 (n= 15) - in vitro fertilization of oocytes matured in vitro from fresh ovaries; G3 (n= 15) - ampulla region oocytes in vitro fertilizated. Viability was verified by thawing, oocyte in vitro maturation and fertilization. In vitro embryo development of each group was evaluated by Chi-square test (BioStat 5.0). 123, 224 and 328 oocytes were recovered from G1, G2 and G3, respectively. Significant differences were observed in cleavage rates at 24 hours (embryos with 2 cells or more) between G1 (8%) and G2 (32%) (P< 0.1) and G1 and G3 (49%) (P< 0.05) but not between G2 and G3 (P> 0.05). Blastocysts at 96 hours presented 6%, 11% and 46%, respectively for G1, G2 and G3, differing significantly (P< 0.05). Ovary vitrification, oocyte in vitro maturation and in vitro fertilization were available for the production of in vitro mouse embryos.(AU)

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RESUMO

Resumen El personal involucrado en el área quirúrgica se ve afectado con lesiones musculoesqueléticas por esfuerzos y movimientos repetitivos acumulados. La gravedad de sus lesiones está dada en función de las posturas de trabajo, la especialidad quirúrgica y la disposición de los elementos con los que interactúa. La ergonomía ha tomado relevancia ya que ha hecho aportes muy importantes para las condiciones de trabajo en diferentes áreas. Aun cuando en la literatura se pueden encontrar diversas investigaciones de la frecuencia y los efectos de las lesiones ocupacionales en el personal del área quirúrgica, escasos estudios han propuesto pautas para el diseño ergonómico de quirófanos. El presente estudio engloba cuatro criterios ergonómicos que deben considerarse para el diseño de quirófanos.

Abstract Personnel involved in the surgical area are affected with musculoskeletal injuries due to accumulated repetitive stress and movements. The severity of the injuries is given according to the work postures, the surgical specialty and the arrangement of the elements in the operating room. Ergonomics has become relevant since it has made very important contributions to working conditions in different areas. Although in the literature investigations of the frequency and effects of occupational injuries on surgical staff can be found, few studies have proposed guidelines for the ergonomic design of operating rooms. The present study encompasses four ergonomic criteria that should be considered for the design of operating rooms.

RESUMO

Recent quantitative approaches for studying several aspects of urban life and infrastructure have shown that scale properties allow the understanding of many features of urban infrastructure and of human activity in cities. In this paper, we show that COVID-19 virus contamination follows a similar pattern in different regions of the world. The superlinear power-law behavior for the number of contamination cases as a function of the city population, with exponent ß of the order of 1.15 is always obtained. Due to the strong indication that scaling is a determinant feature of covid-19 spread, we propose an epidemiological model that embodies a fractal structure, allowing a more detailed description of the observed data about the virus spread in different countries and regions. The hypothesis that fractal structures can be formed in cities as well as in larger networks is tested, indicating that indeed self-similarity may be found in networks connecting several cities.

RESUMO

The use of frozen semen for artificial insemination is the main approach utilised for the genetic improvement of most domesticated species. The advantages include lower transportation costs, continuous availability of semen, fewer occurrences of sexually transmitted diseases and the incorporation of desirable genes in a relatively short amount of time. Nevertheless, the use of frozen semen in buffalo herds remains limited due to the loss of sperm quality when buffalo semen is frozen. So, the goal of this study was to evaluate the pre- and post-cryopreservation quality of buffalo semen diluted in three distinct freezing media: Tris-egg yolk, Botu-bov® (BB) and ACP-111®. Thirty-two ejaculates from four bulls were analysed in terms of kinetics, morphology and sperm viability by epifluorescence microscope. Thawed samples were also evaluated for capacitation-like damage, DNA fragmentation and plasma and acrosomal membrane integrity using flow cytometry. The Tris-egg yolk and BB® extenders yielded better results than the ACP-111® extender for kinetics parameter (total motility, progressive motility and percentage of rapid cells). However, semen samples were similar for parameters evaluated by flow cytometry. Taken together, the data indicate that in comparison with Tris-egg yolk and BB extender, ACP-111® can also be used as an extender for buffalo semen cryopreservation.

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RESUMO

The present study investigated the hormonal profile and expression of prostaglandin F2α (PGF2α), oxytocin and estrogen receptors in uterine tissues of postpartum cows treated with cloprostenol. Twenty Holstein-Zebu crossbred cows were treated with saline solution (treatment CONT) or cloprostenol (treatment CLO), both administered two and five days postpartum. Blood samples were collected on days two, seven, 14, 21 and 28 postpartum for progesterone, PGF2α metabolite (PGFM) and estradiol determination, and endometrial biopsy was performed in order to quantify the expression of oxytocin receptor (OXTR), prostaglandin F receptor (PTGFR) and estrogen receptor 1 (ERS1) genes. In the CLO treatment, expression of OXTR was reduced (P<0.05) but no difference (P>0.05) between treatments was found for PTGFR and ERS1 expression. Estrogen concentrations increased progressively until day 14 (P<0.05) and the highest OXTR expression and lowest PTGFR expression were observed on day 14 (P<0.05) in both treatments. Serum PGFM concentrations were high throughout the experiment. In conclusion, cloprostenol administration at days two and five of postpartum seems to reduce OXTR expression in the endometrium in crossbred cows.(AU)

O presente estudo avaliou o perfil hormonal e a expressão gênica de receptores de prostaglandina F2α (PGF2α), ocitocina e estrógeno no endométrio de vacas pós-parto tratadas com cloprostenol. Vinte vacas mestiças Holandês-Zebu foram tratadas com solução salina (tratamento CONT, n = 10) ou cloprostenol (tratamento CLO, n = 10), ambos administrados dois e cinco dias após o parto. Amostras de sangue foram coletadas nos dias dois, sete, 14, 21 e 28 pós-parto para mensuração de progesterona, de metabólito de PGF2α (PGFM) e de estradiol, e foram obtidas biópsias endometriais para quantificar a expressão de PTGFR, OXTR e ESR1. No tratamento CLO, a expressão gênica de receptores de ocitocina foi menor (P<0,05). As concentrações de estrógeno aumentaram progressivamente até o dia 14 (P<0,05). A maior expressão de OXTR foi observada no dia 14 (P<0,05). A expressão de ESR1 foi semelhante entre os tratamentos (P>0,05). Os níveis de PGFM foram altos durante todo o estudo. Conclui-se que a administração de cloprostenol nos dias dois e cinco pós-parto parece diminuir a expressão de OXTR no endométrio em vacas mestiças.(AU)

Assuntos

RESUMO

The present study investigated the hormonal profile and expression of prostaglandin F2α (PGF2α), oxytocin and estrogen receptors in uterine tissues of postpartum cows treated with cloprostenol. Twenty Holstein-Zebu crossbred cows were treated with saline solution (treatment CONT) or cloprostenol (treatment CLO), both administered two and five days postpartum. Blood samples were collected on days two, seven, 14, 21 and 28 postpartum for progesterone, PGF2α metabolite (PGFM) and estradiol determination, and endometrial biopsy was performed in order to quantify the expression of oxytocin receptor (OXTR), prostaglandin F receptor (PTGFR) and estrogen receptor 1 (ERS1) genes. In the CLO treatment, expression of OXTR was reduced (P<0.05) but no difference (P>0.05) between treatments was found for PTGFR and ERS1 expression. Estrogen concentrations increased progressively until day 14 (P<0.05) and the highest OXTR expression and lowest PTGFR expression were observed on day 14 (P<0.05) in both treatments. Serum PGFM concentrations were high throughout the experiment. In conclusion, cloprostenol administration at days two and five of postpartum seems to reduce OXTR expression in the endometrium in crossbred cows.(AU)

O presente estudo avaliou o perfil hormonal e a expressão gênica de receptores de prostaglandina F2α (PGF2α), ocitocina e estrógeno no endométrio de vacas pós-parto tratadas com cloprostenol. Vinte vacas mestiças Holandês-Zebu foram tratadas com solução salina (tratamento CONT, n = 10) ou cloprostenol (tratamento CLO, n = 10), ambos administrados dois e cinco dias após o parto. Amostras de sangue foram coletadas nos dias dois, sete, 14, 21 e 28 pós-parto para mensuração de progesterona, de metabólito de PGF2α (PGFM) e de estradiol, e foram obtidas biópsias endometriais para quantificar a expressão de PTGFR, OXTR e ESR1. No tratamento CLO, a expressão gênica de receptores de ocitocina foi menor (P<0,05). As concentrações de estrógeno aumentaram progressivamente até o dia 14 (P<0,05). A maior expressão de OXTR foi observada no dia 14 (P<0,05). A expressão de ESR1 foi semelhante entre os tratamentos (P>0,05). Os níveis de PGFM foram altos durante todo o estudo. Conclui-se que a administração de cloprostenol nos dias dois e cinco pós-parto parece diminuir a expressão de OXTR no endométrio em vacas mestiças.(AU)

Assuntos

RESUMO

The aim of this study was to investigate the effects of different concentrations of oral supplementation with selenium (Se) upon ram sperm parameters. Thirty rams managed in stall under intensive system were used and divided into five groups (six animals per group) as follows: control group (G1) mineral mixture supplementation without Se, group 2 (G2) mineral mixture supplemented with 5 mg/kg Se, group 3 (G3) supplemented with 10 mg/kg Se, group 4 (G4) supplemented with 15 mg/kg Se and group 5 (G5) supplemented with 20 mg/kg Se. For each group, there was an adjustment period of 14 days. The experimental period was 350 days. Every 56 days, the animals were weighed and semen samples were collected by electroejaculation. Semen analysis included volume, mass moviment, total motility, vigour, concentration and morphology. For plasmatic and acrosomal membrane integrity evaluation and mitochondrial membrane potential were used a combination of fluorescent probes. Differences between means values obtained by analysis of variance were verified by Tukey test with 5% probability. There was no statistical difference between treatment groups in relation to volume, mass moviment, total motility, vigour, concentration, plasma and acrosomal membrane integrity (p > .05). Sperm morphology was different between treatment groups, the G1 (0 mg of selenium) had the highest percentage of major defects (11.11 ± 1.11a ; p < .05). It was concluded that selenium decrease the percentage of sperm defects and did not directly influence on ram sperm volume, mass moviment, total motility, vigour, concentration and membrane integrity.

Assuntos

RESUMO

This study evaluated the plasma membrane integrity, acrosomal membrane integrity, and mitochondrial membrane potential of Nelore bull sperm from early puberty to early sexual maturity and their associations with sperm motility and vigor, the mass motility of the spermatozoa (wave motion), scrotal circumference, and testosterone. Sixty Nelore bulls aged 18 to 19 months were divided into four lots (n=15 bulls/lot) and evaluated over 280 days. Semen samples, collected every 56 days by electroejaculation, were evaluated soon after collection for motility, vigor and wave motion under an optical microscope. Sperm membrane integrity, acrosomal integrity, and mitochondrial activity were evaluated under a fluorescent microscope using probe association (FITC-PSA, PI, JC-1, H342). The sperm were classified into eight integrity categories depending on whether they exhibited intact or damaged membranes, an intact or damaged acrosomal membrane, and high or low mitochondrial potential. The results show that bulls have a low amount of sperm with intact membranes at puberty, and the sperm show low motility, vigor, and wave motion; however, in bulls at early sexual maturity, the integrity of the sperm membrane increased significantly. The rate of sperm membrane damage was negatively correlated with motility, vigor, wave motion, and testosterone in the bulls, and a positive correlation existed between sperm plasma membrane integrity and scrotal circumference. The integrity of the acrosomal membrane was not influenced by puberty. During puberty and into early sexual maturity, bulls show low sperm mitochondrial potential, but when bulls reached sexual maturity, high membrane integrity with high mitochondrial potential was evident.(AU)

Este estudo avaliou a integridade da membrana plasmática, da membrana acrossomal e o potencial da membrana mitocondrial de espermatozoides de touros da raça Nelore da puberdade até à maturidade sexual e suas correlações com motilidade, vigor, turbilhão dos espermatozoides, circunferência escrotal e testosterona. Sessenta touros da raça Nelore, com idade entre 18 e 19 meses, foram divididos em quatro lotes (n=15 touros / lote) e foram avaliados por 280 dias. Coletaram-se as amostras de sêmen a cada 56 dias por eletroejaculação e, logo após, foram determinados a motilidade, o vigor e o turbilhão dos espermatozoides por microscopia óptica. A integridade da membrana de esperma, da membrana acrosomal e da atividade mitocondrial foi avaliada por microscopia de fluorescência, utilizando-se associação das sondas (FITC-PSA, PI, JC-1, H342). Os espermatozoides foram classificados em oito categorias de integridade, dependendo se eles exibiram membranas plasmática e mitocondrial intactas ou danificadas e potencial mitocondrial elevado ou baixo. Os resultados mostram que os touros têm uma baixa quantidade de espermatozoides com membranas íntegras na puberdade, com baixa motilidade, vigor e turbilhão. No entanto, nos touros na maturidade sexual precoce, a integridade da membrana dos espermatozoides aumentou significativamente. A taxa de dano à membrana espermática foi negativamente correlacionada com a motilidade, o vigor, o movimento das ondas e a concentração de testosterona nos touros, e uma correlação positiva existiu entre a integridade da membrana plasmática e a circunferência escrotal. A integridade da membrana acrossomal não foi influenciada pela puberdade.(AU)

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