Mathematical models to study the biological phosphorus flow in sheep fed increasing levels of mineral

Dois modelos compartimentais foram aplicados e comparados para avaliar o fluxo biológico de fósforo em ovinos que receberam dietas com níveis crescentes do mineral - 0, 2, 4 e 6g por dia. Foram utilizados 24 machos, da raça Santa Inês, com média de peso de 33,6kg. Foi utilizado fosfato bicálcico como fonte de fósforo e 32P como traçador. Avaliou-se o fluxo de fósforo entre os compartimentos: trato gastrintestinal, sangue, ossos e tecidos moles, além da ingestão, excreção e balanço do mineral. O incremento na ingestão de P aumentou a perda fecal do mineral. O fluxo de fósforo entre o trato gastrintestinal e o sangue e o fluxo contrário foram influenciados de forma quadrática pelo incremento na ingestão, diminuindo após a ingestão de 5,5g/dia, sem diferença entre os modelos avaliados. Os modelos estudados mostraram diferenças em relação ao fluxo entre sangue, ossos e tecidos moles, sem efeito dos tratamentos sobre o balanço geral do mineral, porém os níveis de ingestão praticados interferiram no fluxo biológico do fósforo. A disponibilidade biológica do fósforo ingerido diminuiu quando a ingestão superou a necessidade do animal, o que aumentou as excreções no ambiente. A quantificação do fluxo biológico de fósforo diferiu quando aplicados os modelos estudados em decorrência da sua estrutura.Two compartimental models were applied and compared to evaluate the biological flow of P in lambs fed diets containing increasing levels of P (0, 2, 4 and 6g per day). Twenty four Santa Inês lambs with liveweight of 33.6kg were used. Dicalcium phosphate was used as P source and 32P as a tracer. P flow between compartments (gastrointestinal tract, blood, bones and soft tissues), ingestion, excretion and the mineral balance were evaluated. The increase in P intake increased fecal P loss. P flow from gastrointestinal tract to blood stream and opposite flow were affected quadratically by increased P intake, decreasing after the ingestion of 5.5g/day, without a difference among models. The models studied showed differences regarding the P flow between blood, bone and soft tissues, however, the P balance was not affected by the treatments. The increased P levels interfered with the biological P flow in sheep. The bioavailability of P diet decreases when intake exceeds the animal requirement, increasing losses to the environment. The quantification of biological P flow was different between models due to the structure of each one.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNPqFAPEMI

Cryopreservation of collared peccary (Pecari tajacu) semen using different freezing curves, straw sizes, and thawing rates

AbstractThe objective of this study was to verify the effect of different freezing curves, straw sizes, and thawing rates on the cryopreservation of collared peccary semen. Twelve ejaculates were obtained from captive adult males by electroejaculation, and evaluated for sperm motility, kinetic rating, viability, morphology, and functional membrane integrity. The ejaculates were diluted in a coconut water extender (ACP-116c) with egg yolk and glycerol, packaged into 0.25mL or 0.50mL plastic straws and cryopreserved in liquid nitrogen following a slow (−10°C/min) or a fast (−40°C/min) freezing curve. After one week, samples were thawed at 37°C/1min or 70°C/8s and evaluated as reported for fresh semen, and also for kinematic parameters (computerized analysis). A significant decrease in sperm motility and kinetic rating was observed after glycerol addition at 5°C and also after thawing for all the treatments (P<0.05). Regarding post-thaw semen variables, no differences were verified between freezing curves when the same straw size and thawing rate were taken as reference (P>0.05). In general, values for sperm characteristics found after thawing at 37°C were better preserved than at 70°C (P<0.05), both in the use of 0.25mL or 0.50mL straws, which were similar for semen packaging (P>0.05). The evaluation of the kinematic parameters of sperm motility confirmed these results at values varying from 20% to 30% motile sperm for the samples thawed at 37°C, and values fewer than 12% motile sperm for samples thawed at 70°C (P<0.05). In conclusion, we recommend the use of a fast freezing curve that reduces the time spent on the cryopreservation of collared peccary semen, which could be packaged both in 0.25mL or 0.50mL straws, but the thawing should be conducted at 37°C/1min

Microscopic Origin of Non-Gaussian Distributions of Financial Returns

In this paper we study the possible microscopic origin of heavy-tailed probability density distributions for the price variation of financial instruments. We extend the standard log-normal process to include another random component in the so-called stochastic volatility models. We study these models under an assumption, akin to the Born-Oppenheimer approximation, in which the volatility has already relaxed to its equilibrium distribution and acts as a background to the evolution of the price process. In this approximation, we show that all models of stochastic volatility should exhibit a scaling relation in the time lag of zero-drift modified log-returns. We verify that the Dow-Jones Industrial Average index indeed follows this scaling. We then focus on two popular stochastic volatility models, the Heston and Hull-White models. In particular, we show that in the Hull-White model the resulting probability distribution of log-returns in this approximation corresponds to the Tsallis (t-Student) distribution. The Tsallis parameters are given in terms of the microscopic stochastic volatility model. Finally, we show that the log-returns for 30 years Dow Jones index data is well fitted by a Tsallis distribution, obtaining the relevant parameters.Comment: 13 pages, 4 figures. Several clarifying comments, new references and acknowledgments adde

Study on Awareness on the Mercury Usage in Sri Lankan Small Scale Jewellery Sector

Mercury is utilised in extensive amounts for gold recovery from the waste produced during the traditional gold jewellery manufacturing particularly in the Small Scale Jewellery Sector (SSJS). Due to its toxicity and bioaccumulation potential this can cause for serious health effects and environmental pollution. Colombo and Gampaha districts are the main two districts where SSJS is mostly confined. Therefore, this study was focused to assess the amount of mercury usage in SSJS through a structured interview and a questionnaire survey among 120 goldsmiths from these districts. It was revealed that, gold is recovered once in a six month period or annually by using significant amounts of mercury which is totally depends on the workload and amount of waste collected.In this process, the waste is mixed with mercury to form Hg-Au amalgam and it is roasted to recover gold while mercury gets removed through vitalisation. It was disclosed that, about 4 g of mercury is used to refine one pound of gold (8 g). None of the respondents practice any safety precautions or proper ventilation techniques during this process. Therefore they get readily exposed to mercury vapor. Among the interviewees, only 10% of manufacturers were aware about the toxicity of mercury and do not use mercury in gold refining process while 20% of the individuals were not aware about the harmful effects of mercury. However, 70% of the respondents were aware about the toxic effects of mercury but use extensively as a rapid way off extracting gold from waste. 90% of the inspected workshops had very poor ventilation facilities thus increase the susceptibility of exposure to mercury vapor. 24% of the respondents store mercury in unsafe plastic bags which can easily get damaged and released into the environment. Approximately 25% of the respondents revealed that they had some health issues after they engaged in gold refining. Therefore biomonitoring assessment is recommended for a better understanding of mercury exposure levels of the people engaged in gold refining in SSJS.Keywords: Gold refining, Mercury, Small scale jewellery secto

Preparations for field testing for the performance validation of piled wind turbine foundations in expansive clays

Field-testing of piles in an expansive clay is required for the validation of the design criteria for wind turbine foundations in such soil profiles. The test programme includes lateral load tests to investigate the horizontal stiffness of the soil and vertical plug pull-out tests to examine the axial capacity of pile-soil interface. These tests will be conducted in both dry and wet conditions to study the range of expected responses of the pile and evaluate how the changing soil moisture condition affects the pile behaviour. In addition, an instrumented pile socketed into bedrock will be used to determine the strain induced in the pile due to soil heave as the soil saturation levels increase. For the execution of these tests, a large open area with expansive clay of a sufficient depth is required; a stable stratum below the clay is desirable for the socketing of the long piles. An important component of the investigation is the characterisation of the expansive clay profile. A preliminary site investigation has been carried out on the field-testing site which will be supported by further laboratory testing. Details of the soil profile and site characterisation which will be used in the future analyses of the fieldtesting results are presented

O AVANÇO DA OCUPAÇÃO ANTRÓPICA EM ÁREA DE RISCO NA SERRA DO TEPEQUÉM - RR

A serra do Tepequém, no Norte do estado de Roraima, tem passado por intensas modificações em sua paisagem ocasionada tanto por ação natural como antrópica. A ocupação na região tem contribuído para retirada da vegetação e abertura de estradas, o que intensifica a vulnerabilidade do solo e os impactos ambientais e antrópicos. Na serra, as construções ocupam áreas próximas a encostas, rede de drenagem e feições erosivas lineares que apresentam dinâmica constante em decorrência da ação climática

Prevalência de enteroparasitoses em crianças de creches públicas da cidade de Belo Horizonte, Minas Gerais, Brasil

The objective of this study was to verify the occurrence of intestinal parasites in 3 to 6-year-old children from daycare centers maintained by the municipal government of Belo Horizonte, Minas Gerais, Brazil. Coproparasitological tests performed in 472 children have shown that 24.6% of them had some type of parasites, 6.6% of the children having more than one type. Among protozoa, Entamoeba coli (14.0%) and G. duodenalis (9.5%) were the most prevalent, whereas Ascaris lumbricoides (3.0%) and Trichuris trichiura (1.1%) were the most frequent among the helminths. Thus, we can observe that intestinal parasites still represent a serious public health problem in Belo Horizonte, especially among children and in areas where the socioeconomic conditions are less favorable.O objetivo deste trabalho foi verificar a ocorrência de parasitos intestinais em crianças de 3 a 6 anos de idade, oriundas de creches mantidas pela Prefeitura Municipal de Belo Horizonte, Minas Gerais, Brasil. Exames coproparasitológicos realizados em 472 crianças demonstraram que 24,6% apresentavam algum tipo de parasitose, sendo que 6,6% apresentavam mais de um parasito. Entre os protozoários, Entamoeba coli (14,0%) e G. duodenalis (9,5%) foram os mais prevalentes, enquanto Ascaris lumbricoides (3,0%) e Trichuris trichiura (1,1%) foram os mais encontrados entre os helmintos. Desta forma, observa-se que as parasitoses intestinais ainda são um problema de saúde pública em Belo Horizonte, principalmente entre a população infantil e em áreas onde as condições sócio-econômicas são menos favoráveis

Distinguishing sequences for partially specified FSMs

Distinguishing Sequences (DSs) are used inmany Finite State Machine (FSM) based test techniques. Although Partially Specified FSMs (PSFSMs) generalise FSMs, the computational complexity of constructing Adaptive and Preset DSs (ADSs/PDSs) for PSFSMs has not been addressed. This paper shows that it is possible to check the existence of an ADS in polynomial time but the corresponding problem for PDSs is PSPACE-complete. We also report on the results of experiments with benchmarks and over 8 * 106 PSFSMs. © 2014 Springer International Publishing

Effect of artificial shading on performance and reproductive parameters of semi-confined young Brangus bulls

Thirty Brangus bulls were used in a 90-d study to assess the effect of artificial shading on the performance and reproductive characteristics of semi-confined cattle. Animals were kept in four one-ha paddocks in two groups of eight for shade treatment (5 m²/animal of 80% solar block shade cloth) and two groups of seven animals in no-shade treatment. Each treatment had two homogeneous groups, each divided into heavy-bulls (351-450 kg) and light-bulls (300-350 kg). Time spent under shade, time standing, average daily gain, testicular development and sperm quality were investigated. Animals spent 24% of the daylight under the shade and no-shaded bulls spent more time standing (P 0.05) and testicular development between shaded and no-shaded animals. However, scrotal perimeter was higher for shaded light animals compared to no-shaded light bulls (P < 0.10). Sperm motility increase during the experimental period for shaded animals (P < 0.05) and sperm abnormalities were higher for the shaded ones (P < 0.05). Although the results did not indicate pronounced benefits on cattle performance, this resource was an important alternative because it appears to provide an improvement in some reproductive parameters and ensure a better thermal comfort to the animals