Flutuação das proteínas séricas em vacas primíparas e multíparas no período pré-parto

The fluctuation of serum protein was investigated in two groups of milk cows, 6 primiparous and 6 multiparous, during the last six weeks pre-partum. Electrophoresis and the biuret method were used to analyse the serum proteins. Blood was collected from the coccigeal region at 5, 4, 3, 2, 1 weeks pre-partum and at birth. The results indicate a decrease in the total protein concentration (p < 0.0001) as a consequence of immunooglobulin concentration decrease (p < 0.0001) during the experimental period. The total protein decreased from 9.82 + 0.7 g/100 ml, six weeks pre-partum, to 7.92 + 0.6 g/100 ml, at birth (minimum value registered). In the same period immunoglobutin decreased from 4.12 + 0.7 g/100 ml to 2.40 + 0.5 g/100 ml (minimum value registered). Considering the two groups of cows separately, the multiparous showed a tendency to decrease more the immunoglobulin concentration (p < 0.09), when compared to primiparous.O comportamento das proteínas séricas foi avaliado em dois grupos de vacas de leite, 6 primíparas e 6 multíparas, durante as ultimas 6 semanas pré-parto. Para separação da fração protéica foi empregado o método de eletroforese, enquanto para quantificação da proteína total foi utilizado o método de biureto. O sangue, retirado da região coccígea, foi amostrado nos períodos 5, 4, 3, 2, 1 semanas pré-parto e no dia do parto. Os resultados indicam uma queda na concentração da proteína total (p < 0.0001), em função do decréscimo da concentração de imunoglobulina (p < 0.0001), durante o período analisado. A proteína total decresceu de 9,82 + 0,7 g/100 ml, na quinta semana pré-parto, para 7,92 + 0,6 g/100 ml no dia do parto (valor mínimo médio registrado). No mesmo período, a imunoglobulina variou de 4,12 + 0,7 g/100 ml para 2,40 + 0,5 g/100 ml (valor mínimo médio registrado). Considerando-se os dois grupos de vacas separadamente, as multíparas mostraram uma tendência de decréscimo mais acentuado na concentração de imunoglobulina (p < 0.09) quando comparadas com as primíparas

The obstacle problem for water tanks

In this paper we discuss the problem of computing and analyzing the static equilibrium of a non rigid water tank. Specifically, we fix the amount of water contained in the tank, modelled as a membrane. In addition, there are rigid obstacles that constrain the deformation. This amounts to a non convex variational problem. We derive the optimality system and its interpretation in terms of equilibrium of forces. A second order sensitivity analysis, allowing to compute derivatives of solutions and a second order Taylor expansion of the cost function, is performed, in spite of the fact that the cost function is not twice differentiable. We also study the finite elements discretization, introduce a decomposition algorithm for the numerical computation of the solution, ans display numerical results

Efeito de diferentes manejos de fornecimento prolongado de colostro sobre os níveis de proteína e albúmina séricas e desempenho de bezerras recém-nascidas

The serum total protein and albumin concentrations and the performance under different milk feeding programs were evaluated in twenty-four female Holstein newborn calves, randomly allocated in three treatments. The animals were daily fed milk or supplemental colostrum, in different feeding programs during the first thirty days of Ufe. Blood samples were collected at 3; 5;10; 15; 17; 20; 22; 25; 30; 40; 50 and 60 days of age and analysed for serum total protein and serum albumin. Animals were weighed at 0; 5; 10; 15; 20; 25; 30; 40; 50 and 60 days after birth. In the first sixty days, the serum total protein concentration in treatment 3 (colostrum fed twice a day) was higher (p < 0.05) than in treatment 1 (milk). The concentration of serum was also different at different ages (p < 0.0001). During the experimental period the total protein decreased (equation r² = 0.98). Serum albumin levels were similar at all ages, but different in treatments. Treatment 2 (colostrum fed once a day) levels were higher (p < 0.05) than in treatment 1 for serum albumin. Treatment 3 body weight gain was higher (p < 0.05) than in treatment 1 during the experimental period. It was concluded that the best performance was found in calves that received a supplemental colostrum diet twice a day.Os níveis séricos de proteína total e albúmina e o desempenho de bezerras holandesas foram estudados utilizando-se 24 animais recém-nascidos em um delineamento experimental inteiramente ao acaso em parcelas subdivididas, com três tratamentos à base de leite e colostro suplementar, a saber: tratamento 1 - colostro materno no 1&deg; dia de vida (idem para tratamentos 2 e 3) e 2 litros de leite pela manhã e 2 litros de leite à tarde, do 2&deg; dia de vida até o 30&deg; dia de vida; tratamento 2 - fornecimento de 0,8 litros de leite + 1,2 litros de colostro pela manhã e 2 litros de leite à tarde, até 30 dias de idade; tratamento 3 - fornecimento de 1,4 litros de leite + 0,6 litros de colostro pela manhã e igual dieta à tarde, até 30 dias de idade. Amostras de sangue foram coletadas aos 3, 5, 10, 15,17, 20, 22, 25, 30, 40, 50 e 60 dias de vida e analisadas quanto à concentração de proteína total e albúmina séricas.Os animais foram pesados ao nascer e aos 5, 10, 15, 20, 25, 30, 40, 50 e 60 dias de idade. Os animais do tratamento 3 (colostro duas vezes/dia) tiveram concentração de proteína total sérica superior (p < 0,05) a dos animais do tratamento 1(leite). O nível sérico de proteína total variou entre idades experimentais (p < 0,0001). Houve redução da concentração de proteína total durante o período experimental (r² = 0,98). A albúmina sérica não diferiu entre as idades experimentais, havendo porém, diferença entre tratamentos, sendo que os animais do tratamento 2 (colostro uma vez/dia) superaram (p < 0,05) os do tratamento 1 (leite) em relação a está variável. O ganho de peso no periodo foi maior (p < 0,05) no tratamento 3 (colostro duas vezes/dia) do que no tratamento 1 (leite). Concluiu-se que o fornecimento de colostro suplementar misturado ao leite duas vezes ao dia proporcionou melhor desempenho das bezerras, evidenciando o seu alto valor nutricional

Influence of extended colostrum feeding on protein fluctuation of new born calves with different acquired passive immunity

The objective of this study was to evaluate the protein fluctuation of 32 Holstein newborn calves under different milk feeding programs. Animals with high and low condition of acquired passive immunity, were splited in two groups, with and without extended colostrum feeding. The treatments were: T1 - high/milk; T2 - low/milk; T3 -high/colostrum; T4 - low/colostrum. Total protein (TP), albumin and imunoglobulin G (IgG) present in the serum of the calves were evaluated. Calves of Tl and T3 showed higher concentration of TP and IgG as compared to T2 and T4. TP and albumin concentration were higher (P = 0,0001 e p = 0,059) in T3 and T4 in relation to animals in T1 and T2. The lowest concentration of PT and IgG were higher (p = 0,082 e p = 0,0001) in Tl and T3 as compared to T2 and T4. The date when the lowest concentrations of TP ocurred in Tl and T3, 40 days, was superior (p = 0,0012) to 20 days found in T2 and T4. The same ocurred to IgG (p = 0,060) with dates of 50 and 40 days for high (T1 and T3) and low (T2 and T4) groups respectively. Animals that received colostrum (T3 and T4) showed, only for TP, higher (p = 0,0002) concentrations in relation to the minimum concentration, which was registred at the age of 30 days. The date when the lowest concentration of IgG occurred was not different between animals that received colostrum and milk (40 days). According to the results it is suggested that colostrum in the diet has a positive effect in the serum protein synthesis, which in addition to immunoglobulins play an important role in the serum protein fluctuation of the newborn calves.O presente trabalho teve como objetivo avaliar o comportamento das proteínas séricas de 32 bezerros recém-nascidos submetidos a diferentes programas de aleitamento. Foram utilizados animais com duas diferentes condições de imunidade passiva adquirida, alta e baixa, divididos em dois grupos, com e sem fornecimento prolongado de colostra. Os tratamentos foram os seguintes: T1 - alto/leite; T2 -baixo/leite; T3 - alto/colostro; T4 - baixo/ colostro. Foram avaliados os parâmetros séricos de proteína total (PT), albumina e imunoglobulina G (IgG). O grupo alto (T1 e T3) apresentou uma concentração média superior de proteína total (p = 0,0033) e imunoglobulina (p = 0,0001) séricas comparadas com os valores encontrados para o grupo baixo (T2 e T4). Proteína total e albumina apresentaram concentrações médias superiores (p = 0,0001 e p = 0,059) no grupo colostra (T3 e T4) comparado com o grupo leite (T1 e T2). Os valores mínimos médios para PT e IgG foram superiores (p = 0,082 e p = 0,0001) no grupo alto comparado com o grupo baixo. A data de ocorrência do valor médio mínimo no grupo alto para PT foi 40 dias, valor superior (p = 0,0012) aos 20 dias encontrado para o grupo baixo. O mesmo ocorreu para IgG (p = 0,060), tendo sido obtido 50 e 40 dias, respectivamente, para os grupos alto e baixo. Os animais que receberam colostra (T3 e T4) apresentaram, apenas para PT, valor superior (p = 0,0002) para o parâmetro menor valor médio, que ocorreu aos 30 dias de idade. A data de ocorrência do valor médio mínimo para IgG não diferiu entre os animais que receberam colostro e leite (40 dias). O fornecimento prolongado de colostro na dieta pode favorecer o processo de síntese de proteínas séricas em bezerros recém-nascidos

Network segregation in a model of misinformation and fact checking

Misinformation under the form of rumor, hoaxes, and conspiracy theories spreads on social media at alarming rates. One hypothesis is that, since social media are shaped by homophily, belief in misinformation may be more likely to thrive on those social circles that are segregated from the rest of the network. One possible antidote is fact checking which, in some cases, is known to stop rumors from spreading further. However, fact checking may also backfire and reinforce the belief in a hoax. Here we take into account the combination of network segregation, finite memory and attention, and fact-checking efforts. We consider a compartmental model of two interacting epidemic processes over a network that is segregated between gullible and skeptic users. Extensive simulation and mean-field analysis show that a more segregated network facilitates the spread of a hoax only at low forgetting rates, but has no effect when agents forget at faster rates. This finding may inform the development of mitigation techniques and overall inform on the risks of uncontrolled misinformation online

Twitter-based analysis of the dynamics of collective attention to political parties

Large-scale data from social media have a significant potential to describe complex phenomena in real world and to anticipate collective behaviors such as information spreading and social trends. One specific case of study is represented by the collective attention to the action of political parties. Not surprisingly, researchers and stakeholders tried to correlate parties' presence on social media with their performances in elections. Despite the many efforts, results are still inconclusive since this kind of data is often very noisy and significant signals could be covered by (largely unknown) statistical fluctuations. In this paper we consider the number of tweets (tweet volume) of a party as a proxy of collective attention to the party, identify the dynamics of the volume, and show that this quantity has some information on the elections outcome. We find that the distribution of the tweet volume for each party follows a log-normal distribution with a positive autocorrelation of the volume over short terms, which indicates the volume has large fluctuations of the log-normal distribution yet with a short-term tendency. Furthermore, by measuring the ratio of two consecutive daily tweet volumes, we find that the evolution of the daily volume of a party can be described by means of a geometric Brownian motion (i.e., the logarithm of the volume moves randomly with a trend). Finally, we determine the optimal period of averaging tweet volume for reducing fluctuations and extracting short-term tendencies. We conclude that the tweet volume is a good indicator of parties' success in the elections when considered over an optimal time window. Our study identifies the statistical nature of collective attention to political issues and sheds light on how to model the dynamics of collective attention in social media.Comment: 16 pages, 7 figures, 3 tables. Published in PLoS ON

Emergence of metapopulations and echo chambers in mobile agents

Multi-agent models often describe populations segregated either in the physical space, i.e. subdivided in metapopulations, or in the ecology of opinions, i.e. partitioned in echo chambers. Here we show how the interplay between homophily and social influence controls the emergence of both kinds of segregation in a simple model of mobile agents, endowed with a continuous opinion variable. In the model, physical proximity determines a progressive convergence of opinions but differing opinions result in agents moving away from each others. This feedback between mobility and social dynamics determines to the onset of a stable dynamical metapopulation scenario where physically separated groups of like-minded individuals interact with each other through the exchange of agents. The further introduction of confirmation bias in social interactions, defined as the tendency of an individual to favor opinions that match his own, leads to the emergence of echo chambers where different opinions can coexist also within the same group. We believe that the model may be of interest to researchers investigating the origin of segregation in the offline and online world

Debunking in a world of tribes

Social media aggregate people around common interests eliciting collective framing of narratives and worldviews. However, in such a disintermediated environment misinformation is pervasive and attempts to debunk are often undertaken to contrast this trend. In this work, we examine the effectiveness of debunking on Facebook through a quantitative analysis of 54 million users over a time span of five years (Jan 2010, Dec 2014). In particular, we compare how users usually consuming proven (scientific) and unsubstantiated (conspiracy-like) information on Facebook US interact with specific debunking posts. Our findings confirm the existence of echo chambers where users interact primarily with either conspiracy-like or scientific pages. However, both groups interact similarly with the information within their echo chamber. Then, we measure how users from both echo chambers interacted with 50,220 debunking posts accounting for both users consumption patterns and the sentiment expressed in their comments. Sentiment analysis reveals a dominant negativity in the comments to debunking posts. Furthermore, such posts remain mainly confined to the scientific echo chamber. Only few conspiracy users engage with corrections and their liking and commenting rates on conspiracy posts increases after the interaction

Transfer of energy to high frequencies in the cubic defocusing nonlinear Schrodinger equation

We consider the cubic defocusing nonlinear Schrödinger equation on the two dimensional torus. We exhibit smooth solutions for which the support of the conserved energy moves to higher Fourier modes. This behavior is quantified by the growth of higher Sobolev norms: given any δ[much less-than]1,K [much greater-than] 1, s > 1, we construct smooth initial data u 0 with ||u0||Hs , so that the corresponding time evolution u satisfies u(T)Hs[greater than]K at some time T. This growth occurs despite the Hamiltonian’s bound on ||u(t)||H1 and despite the conservation of the quantity ||u(t)||L2. The proof contains two arguments which may be of interest beyond the particular result described above. The first is a construction of the solution’s frequency support that simplifies the system of ODE’s describing each Fourier mode’s evolution. The second is a construction of solutions to these simpler systems of ODE’s which begin near one invariant manifold and ricochet from arbitrarily small neighborhoods of an arbitrarily large number of other invariant manifolds. The techniques used here are related to but are distinct from those traditionally used to prove Arnold Diffusion in perturbations of Hamiltonian systems