Morbidity-mortality and performance evaluation of Brahman calves from in vitro embryo production

<p/> <p>Background</p> <p>The use of bovine <it>in vitro </it>embryo production (IVP) increases the reproductive potential of genetically superior cows, enabling a larger scale of embryo production when compared with other biotechnologies. However, deleterious effects such as abnormal fetal growth, longer gestation period, increased birth weight, abortion, preterm birth and higher rates of neonatal mortality have been attributed to IVP. The aim of this study was to compare the influence of <it>in vitro </it>embryo production and artificial insemination (AI) on gestation length, complications with birth, birth weight, method of feeding colostrum, passive transfer of immunity, morbidity-mortality, and performance in Brahman calves.</p> <p>Results</p> <p>Whilst gestation length and birth weight were significantly increased in IVP-derived calves, no difference in weaning weight was observed between groups. The passive transfer of immunity (PT), was assessed in IVP (n = 80) and AI (n = 20) groups 24 hours after birth by determination of gamma-glutamyl transferase (GGT) and gammaglobulin activity as well as by quantification of the concentration of total protein in serum. No differences in passive transfer or incidences of dystocia and diseases at weaning were observed between groups. Birth weight, method of feeding colostrum and dystocia were not correlated with PT in either group.</p> <p>Conclusions</p> <p>In this study, <it>in vitro </it>embryo production did not affect the health status, development, or passive transfer of immunity in Brahman calves.</p

New mathematical framework for spherical gravitational collapse

A theorem, giving necessary and sufficient condition for naked singularity formation in spherically symmetric non static spacetimes under hypotheses of physical acceptability, is formulated and proved. The theorem relates existence of singular null geodesics to existence of regular curves which are super-solutions of the radial null geodesic equation, and allows us to treat all the known examples of naked singularities from a unified viewpoint. New examples are also found using this approach, and perspectives are discussed.Comment: 8 pages, LaTeX2

Studies on interaction of green silver nanoparticles with whole bacteria by surface characterization techniques

The use of silver nanoparticles (AgNPs) with their novel and distinct physical, chemical, and biological properties, has proven to be an alternative for the development of new antibacterial agents. In particular, the possibility to generate AgNPs coated with novel capping agents, such as phytomolecules obtained via a green synthesis (G-AgNPs), is attracting great attention in scientific research. Recently, we showed that membrane interactions seem to be involved in the antibacterial activity of AgNPs obtained via a green chemical synthesis using the aqueous leaf extract of chicory (Cichorium intybus L.). Furthermore, we observed that these G-AgNPs exhibited higher antibacterial activity than those obtained by chemical synthesis. In order to achieve the green AgNPs mode of action as well as their cellular target, we aimed to study the antibacterial activity of this novel green AgNPs against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. The effect of the G-AgNPs on the bacterial surface was first evaluated by zeta potential measurements and correlated with direct plate count agar method. Afterwards, atomic force microscopy was applied to directly unravel the effects of these G-AgNPs on bacterial envelopes. Overall, the data obtained in this study seems correlate with a multi-step mechanism by which G-AgNPs-lipid membrane interactions is the first step prior to membrane disruption, resulting in antibacterial activity.Fil: Ferreyra Maillard, Anike Paula Virginia. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; ArgentinaFil: Gonçalves, Sónia. Universidade Nova de Lisboa. Faculdade de Ciencias Medicas; PortugalFil: Santos, Nuno C.. Universidade Nova de Lisboa. Faculdade de Ciencias Medicas; PortugalFil: López de Mishima, Beatriz A.. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; ArgentinaFil: Dalmasso, Pablo Roberto. Universidad Tecnologica Nacional. Facultad Regional Cordoba. Departamento de Ingenieria Quimica. Centro de Investigacion y Transferencia En Ingenieria Quimica.; ArgentinaFil: Hollmann, Axel. Universidad Nacional de Quilmes; Argentina. Universidade Nova de Lisboa. Faculdade de Ciencias Medicas; Portugal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Centro de Investigación en Biofísica Aplicada y Alimentos. - Universidad Nacional de Santiago del Estero. Centro de Investigación en Biofísica Aplicada y Alimentos; Argentin

Studies on interaction of green silver nanoparticles with whole bacteria by surface characterization techniques

The use of silver nanoparticles (AgNPs) with their novel and distinct physical, chemical, and biological properties, has proven to be an alternative for the development of new antibacterial agents. In particular, the possibility to generate AgNPs coated with novel capping agents, such as phytomolecules obtained via a green synthesis (G-AgNPs), is attracting great attention in scientific research. Recently, we showed that membrane interactions seem to be involved in the antibacterial activity of AgNPs obtained via a green chemical synthesis using the aqueous leaf extract of chicory (Cichorium intybus L.). Furthermore, we observed that these G-AgNPs exhibited higher antibacterial activity than those obtained by chemical synthesis. In order to achieve the green AgNPs mode of action as well as their cellular target, we aimed to study the antibacterial activity of this novel green AgNPs against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. The effect of the G-AgNPs on the bacterial surface was first evaluated by zeta potential measurements and correlated with direct plate count agar method. Afterwards, atomic force microscopy was applied to directly unravel the effects of these G-AgNPs on bacterial envelopes. Overall, the data obtained in this study seems correlate with a multi-step mechanism by which G-AgNPs-lipid membrane interactions is the first step prior to membrane disruption, resulting in antibacterial activity.Fil: Ferreyra Maillard, Anike Paula Virginia. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; ArgentinaFil: Gonçalves, Sónia. Universidade Nova de Lisboa. Faculdade de Ciencias Medicas; PortugalFil: Santos, Nuno C.. Universidade Nova de Lisboa. Faculdade de Ciencias Medicas; PortugalFil: López de Mishima, Beatriz A.. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; ArgentinaFil: Dalmasso, Pablo Roberto. Universidad Tecnologica Nacional. Facultad Regional Cordoba. Departamento de Ingenieria Quimica. Centro de Investigacion y Transferencia En Ingenieria Quimica.; ArgentinaFil: Hollmann, Axel. Universidad Nacional de Quilmes; Argentina. Universidade Nova de Lisboa. Faculdade de Ciencias Medicas; Portugal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Centro de Investigación en Biofísica Aplicada y Alimentos. - Universidad Nacional de Santiago del Estero. Centro de Investigación en Biofísica Aplicada y Alimentos; Argentin

Efeito da infecção pelos vírus das hepatite B e C na sobrevida de pacientes transplantados renais

OBJECTIVE: To evaluate the impact of HCV (hepatitis C virus) and HBV (hepatitis B virus) infection on the survival of kidney transplant patients and allografts. MATERIAL AND METHODS: One hundred and nine renal allograft recipients were evaluated according to the presence of anti-HCV antibodies and HBV surface antigen. Patients were divided into four groups according to serology results and followed-up for 5 years for evaluation of survival. The differences in age, sex, etiology of renal failure, duration of dialysis, and post-transplantation period were evaluated. RESULTS: The only difference observed was in duration of dialysis prior to renal transplant, which was longer in the anti-HCV positive group of patients. We also observed a higher number of retransplantations in the anti-HCV and HBs Ag groups. There were no significant differences in patient and allograft survival, though there was a trend towards a shorter survival of patients in the anti-HCV positive group (5-year patient survival: 77.8%; relative risk: 1.65; CI: 0.66 - 4.15) and of patients in the co-infection by B and C viruses group (5-year patient survival: 75.0%; relative risk: 1.86; CI: 0.47 - 7.41) compared to the 5-year survival of the index group (5-year patient survival: 86.5%). CONCLUSIONS: We did not find any differences in the survival of kidney transplant patients infected with HCV and/or HBV. A more prolonged follow-up, however, could indicate significant differences among these groups. OBJETIVO: avaliar o impacto da infecção pelo vírus da hepatite B (HBV) e pelo vírus da hepatite C (HCV) na sobrevida de pacientes transplantados renais e seus enxertos. MATERIAIS E MÉTODOS: Cento e nove pacientes transplantados renais foram avaliados quanto à presença de anticorpos contra o HCV e presença do antígeno de superfície do HBV. Os pacientes foram divididos em 4 grupos de acordo com os resultados das sorologias e seguidos pelo período de 5 anos para avaliação das sobrevidas. As diferenças de idade, sexo, etiologia da insuficiência renal, tempo de diálise e tempo pós- ransplante renal foram avaliados nos grupos. RESULTADOS: Os grupos diferiram apenas nos parâmetros de tempo de diálise prévio ao transplante renal, sendo este significativamente maior nos pacientes anti-HCV positivos. Houve maior número de pacientes retransplantados nos grupos dos antiHCV e HbsAg positivos. Não houve diferenças significativas nas sobrevidas de pacientes e enxertos, embora tenha havido tendência a menores sobrevidas dos pacientes no grupo anti-HCV positivo (sobrevida de 5 anos: 77,8%; risco relativo: 1,65; IC: 0,66 - 4,15) e no grupo com co- nfecção pelos vírus B e C (sobrevida de 5 anos: 75%; risco relativo: 1,86; IC: 0,47 - 7,41), comparado à sobrevida de 5 anos no grupo índice, que foi de 86,5% CONCLUSÃO: No presente estudo não se evidenciou  diferença significativa nas sobrevidas de pacientes transplantados renais infectados pelos vírus das hepatites B e C. É possível que, com maior seguimento, constate-se diferenças significativas entre os grupos.

Paleoecological changes in Lake Funda (Flores Island, Azores): tracking human impacts in a remote island lake throughout the past millennium

III International Conference on Island Evolution, Ecology and Conservation - La Réunion 8-13 JulyPrevious studies on lacustrine sedimentary sequences in the Azores show that climate variability and vulcanism along with the arrival of humans played a signi#12;cant role in the recent development of these insular Azorean ecosystems. However, the timing and rate of anthropogenic impacts on these lakes is poorly constrained. Paleoecological research allows us to reconstruct ecological conditions prior to and after human settlement, thereby contributing to our understanding of how species and island ecosystems responded to both natural and anthropogenic disturbances. To assess both types of impacts over the last 1000 years, we analysed the elemental geochemistry on bulk organic matter, diatoms, and chironomid remains in a 994 cm-long sediment core recovered from Lake Funda (Flores Island, Azores) in 2017. Preliminary results from Lake Funda show that human colonization was the main driver of ecological changes. We identi#12;ed three major ecological phases: (1) 950-1350 yr AD, a pristine lake ecosystem with mesotrophic diatom taxa, including benthic and tychoplanktonic life-forms, and free-living chironomids species representing an undisturbed environment; 2) 1350-1450 yr AD, the release of cattle and gradual forest clearance lead to an increase in nutrient inputs and the start of the human-impacted phase; and, (3) after Portuguese settlement, from 1450 yr AD to present, a second human-impacted phase resulted in lake eutrophication and the development of an anoxic hypolimnion due to an increase of nutrient loading. The #12;rst anthropogenic phase resulted in a drastic 50% decline of the overall biodiversity with a shift to planktonic diatom species and free-living chironomids, while the second was characterised by a substantial reduction in the density of chironomids and diatom assemblage shifts towards the dominance of Aulacoseira granulata and A. ambigua suggesting a shift in lake trophy. Other external drivers like major climate oscillations likely play a role within these phases as well. Our study demonstrates the sensitivity of aquatic ecosystems in remote islands to anthropogenic impacts that have the ability to overtake natural forces of variability (i.e., climate).This research is funded by FCT (SFRH/BPD/99461/2014), and through the funded research projects PaleoNAO(CGL2010-15767), RapidNAO (CGL2013-40608-R), PaleoModes (CGL2016-75281-C2), DISCOVERA-ZORES (PTDC/CTA-AMB/28511/2017) and the Luso-America

Mid-to-Late Holocene environmental reconstruction on Pico Island (Azores, Portugal) based on multiproxy analysis of Lake Caveiro sediments

The Azores constitutes the most remote archipelago of the North Atlantic Ocean. Both human colonization and natural changes have significantly modified its ecosystems. To assess the impacts of natural and anthropogenic changes over the last 8200 yr, elemental geochemistry on bulk organic matter, diatoms, Cladocera and chironomid remains were analyzed in a 952-cm long sediment (3.7m depth) from Lake Caveiro. From 8200 to 650 cal yr BP, climatic and volcanic forcing seem to have been the main drivers of biological change. Between 8200 and 6000 cal yr BP, the sedimentary sequence was characterized by dominance of volcaniclastic deposits and high abundance of aerophilic diatoms and sparse Cladocera and chironomid remains. This interval has been interpreted as indicative of unstable conditions because of intermittent renewal of lake bottom substratum owing to repetitive tephra sedimentation. Between 6000 and 3500 cal yr BP, fossil assemblages were dominated by benthic species, with an increasing trend of the planktonic/benthic (P:B) ratio, suggesting stable substratum and rising lake levels. An increase in planktonic taxa and the presence of deep-water chironomid species was found between 3500 and 1300 cal yr BP, suggesting a highstand phase. Between 1300 and 650 cal yr BP, a decreasing trend of the P:B ratio was recorded, implying a further lake shallowing. Moreover, the appearance of flowing water species suggests a period characterized by climate instability. From 650 cal yr BP to the present, a significant increase in primary production and a decline in species richness likely reflect anthropogenic impacts, such as forest clearance and the introduction of exotic species. These results highlight the impact that human, volcanic and climatic drivers have had on the environmental evolution of the ecosystems of Pico Island.This research is funded by Spanish projects PaleoNAO (CGL2010-15767), RapidNAO (CGL2013-40608-R) and PaleoModes (CGL2016-75281-C2).Peer Reviewe

O USO DA METODOLOGIA STEAM EM SALA DE AULA NA DIMENSÃO DA EDUCAÇÃO AMBIENTAL NO CURRÍCULO: reflexões iniciais

A educação na sociedade contemporânea se apresenta com inúmeros desafios, intensificados durante a pandemia do COVID-19, com a inserção emergencial das tecnologias digitais. É neste contexto que este estudo analisa a proposta do uso da metodologia STEAM (acrônimo em inglês para as disciplinas Ciência, Tecnologia, Engenharia, Artes e Matemática) vinculado ao design thinking, de modo contextualizado, ao contemplar a dimensão da educação ambiental no currículo, propondo-se a responder: como a aplicação do STEAM vinculado ao design thinking pode contribuir para a abordagem interdisciplinar na sala de aula a partir de um tema socioambiental? As atividades desta pesquisa foram realizadas em cinco fases, com duas turmas dos sétimos anos do Ensino Fundamental e uma turma do doutorado em Educação em Ciências e Matemática, a partir de um problema socioambiental: o desaparecimento das abelhas no mundo. Para análise dos dados, utilizou-se a análise textual discursiva, que permitiu reconhecer o STEAM e o design thinking como processos que ampliam o interesse e a participação dos envolvidos, conduzindo-os para a discussão do problema, identificando caminhos possíveis. Também foram reveladas as fragilidades do currículo fragmentado da educação básica, o qual se distancia de um princípio básico da educação ambiental: a concepção da totalidade. Desse modo, a pesquisa problematiza a formação dos sujeitos no coletivo para uma transformação cultural no ambiente escolar e na sociedade contemporânea

MarinEye - A tool for marine monitoring

This work presents an autonomous system for marine integrated physical-chemical and biological monitoring – the MarinEye system. It comprises a set of sensors providing diverse and relevant information for oceanic environment characterization and marine biology studies. It is constituted by a physicalchemical water properties sensor suite, a water filtration and sampling system for DNA collection, a plankton imaging system and biomass assessment acoustic system. The MarinEye system has onboard computational and logging capabilities allowing it either for autonomous operation or for integration in other marine observing systems (such as Observatories or robotic vehicles. It was designed in order to collect integrated multi-trophic monitoring data. The validation in operational environment on 3 marine observatories: RAIA, BerlengasWatch and Cascais on the coast of Portugal is also discussed.info:eu-repo/semantics/publishedVersio