Intake Rate and Nutritive Value of Elephant Grass cv. Napier Subjected to Strategies of Rotational Stocking Management

Several research papers on forage tropical grass species have demonstrated that grazing management interferes with sward structure that, in turn, alters patterns of ingestive and foraging behaviour of the grazing animals. For that reason it has been used as explicative variable for adjustments in intake characteristics like bite mass, bite rate, intake rate and nutritive value of the consumed herbage (Fonseca et al. 2012). Tall tufted growing plants like elephant grass (Pennisetum purpureum Schum.) cv. Napier show a continuous pattern of growth characterised by stem elongation during their vegetative state (Da Silva and Carvalho 2005), causing swards to become too tall and out of reach for grazing animals, generating serious difficulties in executing efficient grazing management, particularly when long regrowth periods are used. In that context, the increase in defoliation frequency has positive effects on herbage intake and nutritive value (Palhano et al. 2007), since it favours leaf elongation relative to stem elongation and senescent material accumulation throughout successive grazing cycles. Against that background, the objective of this experiment was to evaluate the components of the short term herbage intake (intake rate, bite mass and bite rate) and the nutritive value of the consumed herbage from elephant grass cv. Napier subjected to strategies of rotational stocking management defined in terms of pre- and post-grazing management targets

Morning and Afternoon Sampling and Herbage Chemical Composition of Rotationally Stocked Elephant Grass cv. Napier

Nutrient intake by grazing animals depends on the amount of dry matter consumed and its chemical composition. Forage grasses, as with any other plants, produce assimilates during the day via photosynthesis to sustain live tissues, plant growth and organic reserves (Taiz and Zeiger 2013). In that context, herbage chemical composition may vary according to variations in the photosynthesis-respiration balance throughout the day. From dawn to dusk the balance increases and herbage dry matter content as well as concentration of soluble carbohydrates increase, the reverse happening from dusk to dawn. That could interfere with nutritive value and nutrient intake of grazing animals (Delagarde 2000), since for a given bite volume the amount of herbage and its composition could vary depending on the time of the day. That could have implications for rotationally managed pastures, indicating a potential effect of time of changing animals from one paddock to the other as a management strategy. Against that background, the objective of this experiment was to evaluate dry matter (DM) content and the concentration of soluble carbohydrates (SC), crude protein (CP), neutral (NDF) and acid (ADF) detergent fibre in herbage samples harvested during the morning and afternoon periods from rotationally stocked elephant grass cv. Napier

Immunization expands B cells specific to HIV-1 V3 glycan in mice and macaques.

Broadly neutralizing monoclonal antibodies protect against infection with HIV-1 in animal models, suggesting that a vaccine that elicits these antibodies would be protective in humans. However, it has not yet been possible to induce adequate serological responses by vaccination. Here, to activate B cells that express precursors of broadly neutralizing antibodies within polyclonal repertoires, we developed an immunogen, RC1, that facilitates the recognition of the variable loop 3 (V3)-glycan patch on the envelope protein of HIV-1. RC1 conceals non-conserved immunodominant regions by the addition of glycans and/or multimerization on virus-like particles. Immunization of mice, rabbits and rhesus macaques with RC1 elicited serological responses that targeted the V3-glycan patch. Antibody cloning and cryo-electron microscopy structures of antibody-envelope complexes confirmed that immunization with RC1 expands clones of B cells that carry the anti-V3-glycan patch antibodies, which resemble precursors of human broadly neutralizing antibodies. Thus, RC1 may be a suitable priming immunogen for sequential vaccination strategies in the context of polyclonal repertoires

Waterborne Toxoplasmosis, Brazil, from Field to Gene

Water was the suspected vehicle of Toxoplasma gondii dissemination in a toxoplasmosis outbreak in Brazil. A case-control study and geographic mapping of cases were performed. T. gondii was isolated directly from the implicated water and genotyped as SAG 2 type I

Tracking arboviruses, their transmission vectors and potential hosts by nanopore sequencing of mosquitoes

The risk to human health from mosquito-borne viruses such as dengue, chikungunya and yellow fever is increasing due to increased human expansion, deforestation and climate change. To anticipate and predict the spread and transmission of mosquito-borne viruses, a better understanding of the transmission cycle in mosquito populations is needed. We present a pathogen-agnostic combined sequencing protocol for identifying vectors, viral pathogens and their hosts or reservoirs using portable Oxford Nanopore sequencing. Using mosquitoes collected in São Paulo, Brazil, we extracted RNA for virus identification and DNA for blood meal and mosquito identification. Mosquitoes and blood meals were identified by comparing cytochrome c oxidase I (COI) sequences against a curated Barcode of Life Data System (BOLD). Viruses were identified using the SMART-9N protocol, which allows amplified DNA to be prepared with native barcoding for nanopore sequencing. Kraken 2 was employed to detect viral pathogens and Minimap2 and BOLD identified the contents of the blood meal. Due to the high similarity of some species, mosquito identification was conducted using blast after generation of consensus COI sequences using RACON polishing. This protocol can simultaneously uncover viral diversity, mosquito species and mosquito feeding habits. It also has the potential to increase understanding of mosquito genetic diversity and transmission dynamics of zoonotic mosquito-borne viruses.</p

Uloga prirodnih spojeva kod raka mliječnih žlijezda u štakora; blagotvorni učinci vodenog ekstrakta Santolina chamaecyparissus L.

Breast cancer is the most diagnosed cancer among women, and a leading cause of death worldwide. Santolina chamaecyparissus L. is a plant with multiple health benefits, including anticancer and anti-diabetic properties. This study aimed to assess the chemopreventive effects of S. chamaecyparissus aqueous extract (SCE) in an animal model of mammary cancer. A total of 28 four-week-old female Wistar rats were divided into four groups: control, MNU-induced (IND), SCE-supplemented (SCE), and SCE+IND. SCE was added to drinking water (12.72 mg/kg body weight) ad libitum. MNU was administered via the intraperitoneal route at 50 days of age. Weekly monitoring of body weight, food/drink intake, humane endpoints, and number of mammary tumours were recorded. Twenty weeks after MNU administration, animals were sacrificed by anaesthetic overdose and a necropsy was performed. Blood samples were used to determine blood count and serum biochemistry analysis, while kidney and liver samples were analysed for oxidative stress. Tumour samples were collected for gene expression and histology studies. SCE chemical composition was analysed by LC-MS and contained 19 phenolic compounds, with the most abundant being myricetin-O-glucuronide and 1,3-O-dicaffeoylquinic acid. Two animals in the IND group were sacrificed due to exceeding the humane endpoint limits. SCE supplementation delayed mammary tumour development, reducing its volume and weight. SCE had a positive impact on haematological parameters, particularly the neutrophil-lymphocyte ratio (P=0.026). No significant differences were observed in serum biochemistry, except for creatinine kinase MB, or in oxidative stress markers. Gene expression analysis showed significantly reduced VEGF expression levels (P=0.0158) in tumours from SCE+IND. These findings suggest that SCE is deserving of further study to identify the individual compounds and to understand its influence on animal models during cancer development.Rak dojke najčešće je dijagnosticiran rak u žena i vodeći uzrok smrti na svijetu. Santolina chamaecyparissus L. je biljka s višestrukim blagotvornim učincima za zdravlje, uključujući antitumorska i antidijabetička svojstva. Cilj je ove studije bio procijeniti kemopreventivne učinke vodenog ekstrakta S. chamaecyparissus (SCE) na životinjama obeljelim od raka mliječnih žlijezda. Dvadeset i osam četiri ženki starih tjedna wistar štakora podijeljeno je u četiri skupine: kontrolnu, MNU-inducirano (IND), s dodatkom SCE (SCE) i SCE+IND. Skupini SCE je dodan vodi za piće (12,72 mg/kg tjelesne mase) ad libitum; MNU je primijenjen intraperitonealnim putem u 50. danu života. Tjedno je bilježeno praćenje tjelesne mase, unosa hrane/tekućine, humano usmrćivanje i broj tumora mliječnih žlijezda. Dvadeset tjedana nakon primjene MNU, životinje su žrtvovane predoziranjem anestetikom i obavljena je razudba. Uzorci krvi su rabljeni za određivanje krvne slike i analizu biokemije seruma, dok su uzeti uzorci bubrega i pluća rabljeni za analize oksidativnog stresa. Uzorci tumora su prikupljeni za studije ekspresije gena i histološke studije. Analiziran je kemijski sastav skupine SCE pomoću LC-MS i otkriveno je da sadrži 19 fenolnih spojeva od kojih su najobilniji bili miricetin-O-glukuronid i 1,3-O-dikafeoilkina kiselina. Dvije životinje iz IND skupini žrtvovane su zbog prekoračenja ograničenja za humano usmrćivanje. Skupini SCE dodatak je odgodio razvoj tumora mliječnih žlijezda, smanjujući njegov volumen i masu. Skupina SCE je imala pozitivni učinak na hematološke parametre, posebice na omjer neutrofila i limfocita (P=0,026). Nikakve značajne razlike nisu otkrivene u biokemiji seruma, osim kreatinin kinaze MB, niti u markerima oksidativnog stresa. Analiza ekspresije gena pokazala je značajno smanjene razina ekspresije VEGF (P=0,0158) u tumora iz skupine SCE+IND. Ovi nalazi ukazuju da bi skupinu SCE trebalo dodatno ispitati da bi se identificirali pojedinačni spojevi i razumio njegov utjecaj na životinjama oboljelih od raka mliječnih žlijezda

Neural-Based Ensembles and Unorganized Machines to Predict Streamflow Series from Hydroelectric Plants

Estimating future streamflows is a key step in producing electricity for countries with hydroelectric plants. Accurate predictions are particularly important due to environmental and economic impact they lead. In order to analyze the forecasting capability of models regarding monthly seasonal streamflow series, we realized an extensive investigation considering: six versions of unorganized machines—extreme learning machines (ELM) with and without regularization coefficient (RC), and echo state network (ESN) using the reservoirs from Jaeger’s and Ozturk et al., with and without RC. Additionally, we addressed the ELM as the combiner of a neural-based ensemble, an investigation not yet accomplished in such context. A comparative analysis was performed utilizing two linear approaches (autoregressive model (AR) and autoregressive and moving average model (ARMA)), four artificial neural networks (multilayer perceptron, radial basis function, Elman network, and Jordan network), and four ensembles. The tests were conducted at five hydroelectric plants, using horizons of 1, 3, 6, and 12 steps ahead. The results indicated that the unorganized machines and the ELM ensembles performed better than the linear models in all simulations. Moreover, the errors showed that the unorganized machines and the ELM-based ensembles reached the best general performances

AVALIAÇÃO MORFOLÓGICA DE CÓRNEAS DE COELHOS CRIOPRESERVADAS COM ETILENOGLICOL

Avaliou-se o etileno glicol com criopreservador de córnea de coelhos. Foram colhidas córneas do bulbo ocular direito e esquerdo de 10 cadáveres de coelhos adultos, machos, da raça Nova Zelândia, com massa corporal variando de 4,0kg a 5,0kg. As peças foram obtidas imediatamente após o abate dos animais realizado em abatedouro. As córneas foram removidas com uma margem de 2,0mm de esclera e banhadas em solução fisiológica 0,9%. As córneas dos bulbos oculares direitos foram fixadas em formol, incluídas em parafina e coradas em hematoxilina-eosina para avaliação em microscopia de luz. As dos globos oculares esquerdos foram imersas em frascos criogênicos contendo solução salina tamponada em fosfato, 0,4% de albumina sérica bovina e 1,5 molar de etilenoglicol. Os frascos foram congelados em nitrogênio líquido à temperatura de -196ºC durante um período de 60 dias. Após descongelamento, as córneas foram submetidas à análise macroscópica e mensuradas a partir de imagens digitalizadas. A preservação de córneas de coelhos com etilenoglicol, em nitrogênio líquido, não ocasiona alterações na transparência, estruturais e morfométricas das camadas que compõem a córnea. PALAVRAS-CHAVE: Coelho; córnea; criopreservação