109 research outputs found
Test of Local Scale Invariance from the direct measurement of the response function in the Ising model quenched to and to below
In order to check on a recent suggestion that local scale invariance
[M.Henkel et al. Phys.Rev.Lett. {\bf 87}, 265701 (2001)] might hold when the
dynamics is of Gaussian nature, we have carried out the measurement of the
response function in the kinetic Ising model with Glauber dynamics quenched to
in , where Gaussian behavior is expected to apply, and in the two
other cases of the model quenched to and to below , where
instead deviations from Gaussian behavior are expected to appear. We find that
in the case there is an excellent agreement between the numerical data,
the local scale invariance prediction and the analytical Gaussian
approximation. No logarithmic corrections are numerically detected. Conversely,
in the cases, both in the quench to and to below , sizable
deviations of the local scale invariance behavior from the numerical data are
observed. These results do support the idea that local scale invariance might
miss to capture the non Gaussian features of the dynamics. The considerable
precision needed for the comparison has been achieved through the use of a fast
new algorithm for the measurement of the response function without applying the
external field. From these high quality data we obtain for
the scaling exponent of the response function in the Ising model quenched
to below , in agreement with previous results.Comment: 24 pages, 6 figures. Resubmitted version with improved discussions
and figure
Natural pigments and biogas recovery from microalgae grown in wastewater
This study assessed the recovery of natural pigments (phycobiliproteins) and bioenergy (biogas) from microalgae grown in wastewater. A consortium of microalgae, mainly composed by Nostoc, Phormidium, and Geitlerinema, known to have high phycobiliproteins content, was grown in photobioreactors. The growth medium was composed by secondary effluent from a high rate algal pond (HRAP) along with the anaerobic digestion centrate, which aimed to enhance the N/P ratio, given the lack of nutrients in the secondary effluent. Additionally, the centrate is still a challenging anaerobic digestion residue since the high nitrogen concentrations have to be removed before disposal. Removal efficiencies up to 52% of COD, 86% of NH4+-N, and 100% of phosphorus were observed. The biomass composition was monitored over the experimental period in order to ensure stable cyanobacterial dominance in the mixed culture. Phycocyanin and phycoerythrin were extracted from harvested biomass, achieving maximum concentrations of 20.1 and 8.1 mg/g dry weight, respectively. The residual biomass from phycobiliproteins extraction was then used to produce biogas, with final methane yields ranging from 159 to 199 mL CH4/g VS. According to the results, by combining the extraction of pigments and the production of biogas from residual biomass, we would not only obtain high-value compounds, but also more energy (around 5-10% higher), as compared to the single recovery of biogas. The proposed process poses an example of resource recovery from biomass grown in wastewater, moving toward a circular bioeconomy
Luteal dynamics in goats: morphological and endocrine features.
Abstract: The aim of this study was to establish the morphologic and endocrine characteristics of luteal dynamics in goats. It was used Toggenburg female goats that showed natural estrus in a 48-hour interval. After estrus, ultrasonographic evaluations of the ovaries were daily performed during 21 days using a portable device (5MHz probe). Blood sample was collected for plasma progresterone (P4) determination. Corpora lutea were detected for the first time on day 5 and progressively increased in size until D9 (1.26 ± 0.08 cm2), with no variation on subsequent days. In females with one ovulation, the first visualization of the corpora lutea was earlier than in those with multiple ovulation (4.54 ± 0.18 vs 5.74 ± 0.25 days). At the moment of the first visualization, luteal area was smaller in animals with single ovulation. Plasma P4 concentration progressively increased until day 9 and it did not show significant increase until luteolysis, characterized by a sharp decrease in P4 concentration, reaching values below 1 ng/mL in 24 hours. The luteal area slowly and gradually decreased in size. It was observed a significant positive correlation between P4 concentration and area during luteogenesis and luteolysis (r = 0.63 and r = 0.50, respectively). When corpus luteum reached its maximum size (D9), female with more than one corpora lutea, with a greater luteal tissue area, did not show P4 concentration higher than those with one ovulation (5.92 ± 0.59 vs 7.04 ± 0.79 ng/mL). These results show that luteal dynamics in Toggenbur goats follow a similar pattern to those observed in other goat breeds and luteal tissue growth was positively correlated with corpora lutea functionality. [Dinâmica luteal em caprinos: caracterÃsticas morfológicas e endócrinas]. Resumo: Objetivou-se neste estudo estabelecer as caracterÃsticas morfológicas e endócrinas da dinâmica luteal em cabras. Foram utilizadas fêmeas da raça Toggenburg que manifestaram estro natural em um intervalo de 48 horas. Após o estro, foram realizadas avaliações ultrassonográficas diárias dos ovários durante 21 dias, utilizando-se um aparelho portátil (5 MHz). Amostras de sangue foram coletadas para dosagem de progesterona (P4) no plasma. Os corpos lúteos foram detectados pela primeira vez no D5 e aumentaram progressivamente de tamanho até o D9 (1,26 ± 0,08 cm2), não havendo variação nos dias subsequentes. Nas fêmeas com uma ovulação, a primeira visualização do corpo lúteo foi mais precoce que naquelas com ovulação múltipla (4,54 ± 0,18 vs 5,74 ± 0,25 dias). No momento da primeira visualização, a área luteal foi menor nos animais com uma ovulação. A concentração plasmática de P4 aumentou progressivamente até o D9 e não apresentou aumento significativo até o momento da luteólise, caracterizada por uma acentuada queda da concentração de P4, atingindo valores inferiores a 1 ng/mL em um intervalo de 24 horas. A área luteal diminuiu de forma lenta e gradual. Foi observada uma correlação positiva significativa entre a área e a concentração de P4 durante a lutegêonese e a luteólise (r = 0,63 e r = 0,50; respectivamente). No dia em que o corpo lúteo atinge sua área máxima (D9), as fêmeas com mais de um corpo lúteo, com maior área de tecido luteal, não apresentaram concentração de P4 superior à daquelas com uma ovulação (5,92 ± 0,59 vs 7,04 ± 0,79 ng/mL). Esses resultados indicam que a dinâmica luteal em caprinos da raça Toggenburg segue padrões semelhantes aos observados em outras raças e em outras espécies e que o crescimento de tecido luteal refletiu positivamente na funcionalidade do corpo lúteo
Effect of hCG administration on accessory corpus luteum formation and area in estrous induced nulliparous Santa Inês ewes.
Proceedings V International Symposium on Animal Biology of Reproduction, October 8-11, 2014, Campinas, SP
On universality in aging ferromagnets
This work is a contribution to the study of universality in
out-of-equilibrium lattice models undergoing a second-order phase transition at
equilibrium. The experimental protocol that we have chosen is the following:
the system is prepared in its high-temperature phase and then quenched at the
critical temperature . We investigated by mean of Monte Carlo simulations
two quantities that are believed to take universal values: the exponent
obtained from the decay of autocorrelation functions and the
asymptotic value of the fluctuation-dissipation ratio . This
protocol was applied to the Ising model, the 3-state clock model and the
4-state Potts model on square, triangular and honeycomb lattices and to the
Ashkin-Teller model at the point belonging at equilibrium to the 3-state Potts
model universality class and to a multispin Ising model and the Baxter-Wu model
both belonging to the 4-state Potts model universality class at equilibrium.Comment: 17 page
Eficiência na indução da luteólise em diferentes dias após a coleta de embriões em bovinos: resultados parciais.
Uso de diferentes tipos de estradiol para a transposição cervical e lavagem uterina em fêmeas Santa Inês.
Dinâmica luteal em cabras da raça Toggenburg: caracterização morfológica e endócrina.
Edição dos Resumos XXII Reunião Anual da Sociedade Brasileira de Tecnologia de Embriões, Guarujá, SP, 2008
Evaluation of superovulatory response in Santa Inês ewes by ultrasonography and laparoscopy.
The development and use of non-invasive techniques would reduce risks of surgery sequels on the same animal and use of the donor could be optimized. The aim of this study was to evaluate the accuracy of ultrasonography performed prior to embryo collection to estimate superovulation response in sheep. Fifteen pluriparous Santa Inês sheep, 2 to 5 year old, with an average body weight of 46.79 ± 6.00 kg and body condition score of 2.96 ± 0.32 (1 to 5 scale) were allocated into 3 groups (GI, GII, GIII) in a cross-over design. In GI, intravaginal sponges (60 mg of medroxyprogesterone acetate; Progespon®, Schering Plough Animal Health, São Paulo, Brazil) were inserted (Day 0) and maintained for 14 days, and the superovulatory (SOV) protocol started on Day 12. In GII and GIII, intravaginal sponges were inserted (Day 0) and maintained for 6 days. On Day 5, the animals were treated with 300 IU of eCG (Novormon 5000®, Schering Plough Animal Health) and 5 mg of dinoprost (Lutalyse® Pfizer Animal Health, São Paulo, Brazil) i.m. Animals in GIII received 0.025 mg of gonadorelin acetate (Gestran-Plus®, Tecnopec, São Paulo, Brazil) i.m. 12 h after sponge withdrawal. In GII and GIII, the SOV protocol started 48 h after sponge removal and a new sponge was inserted immediately after its removal. The SOV protocol in all groups consisted of 200 mg of pFSH (Folltropin-V®, Tecnopec) administered in 6 decreasing doses given every 12 h (50/50, 30/30, and 20/20 mg). At the time of the fifth dose of pFSH, 5 mg of dinoprost was administered i.m. and the sponges were removed. Animals were bred by a sexually mature ram twice a day until the end of estrus. Prior to embryo collection, an ultrasonographic evaluation (5 MHz, Aloka SSD-500, Tokyo, Japan) was performed to determine the number of CL present on both ovaries. The number of CL was further evaluated by laparoscopy, when it was possible to detect poor responders or even non-ovulating animals. Statistical analysis was performed using all tests at the 95% confidence interval by SAEG program. Results are presented as mean ± SE. The number of CL was not different among all groups. The total number (GI, GII, and GIII) of CL determined by ultrasonography (9.09 ± 5.01) was not different (P > 0.05) from that observed by laparoscopy (8.87 ± 5.25). A significant correlation (r = 0.56, P < 0.0005) between evaluation performed by ultrasonography and laparoscopy was observed. These results suggest that ultrasonography can be used to determine the response to the superovulatory protocol. As embryo collection in sheep is performed mainly by surgical techniques, the implementation of non-invasive techniques such as ultrasonography could avoid unnecessary surgeries on animals that did not respond to the SOV protocol, therefore preventing early culling of embryo donors. Top Print this pagePrint Email this page View Issue Contents Abstract Export Citation Tools Print Bookmark Email this page Early Alert Subscribe to our Early Alerts for the latest journal issue contents.Edição dos Proceedings of the Annual Conference of the International Embryo Transfer Society, Córdoba, Argentina, 9?12 January 2010
COMPARAÇÃO DO COMPORTAMENTO DO DECAIMENTO RADIOATIVO ATRAVÉS DE LANÇAMENTOS DE POLIEDROS
Modern physics is part of the High School physics curriculum, but it is rarely covered. Thus, subjects such as radioactivity and radioactive decay are rarely worked in the classroom, and more difficult with associated practice, since radioactive materials are harmful and follow specific legislation for their use. In order to try to overcome this deficiency and provide a practice, a simulation of the radioactive decay curves was performed using sets of polyhedra (physical or virtual), where each set is formed with polyhedra with a certain number of faces. When an atom emits some type of radiation, it is said that the chemical element has undergone radioactive decay and this process, in addition to being a transmutation of matter, is a spontaneous and completely random process. The average time in which half of the atoms in a given sample decay, forming another chemical element, known as the half-life time, is specific to each radioactive chemical element and polyhedra with different numbers of faces can be used to simulate this condition. The probability of a specific atom decaying after a certain period of time can be simulated by comparing the polyhedrons throwings by subtracting the number of polyhedra as a function of one of the chosen faces.A fÃsica moderna faz parte do currÃculo de fÃsica do ensino médio, porém raramente ela é abordada. Dessa maneira, assuntos como radioatividade e decaimento radiativo dificilmente são trabalhados em sala de aula, e mais dificilmente com prática associada visto que materiais radioativos são nocivos e seguem legislação especÃfica para sua manipulação. Para tentar suprir essa deficiência e propiciar uma prática foi realizada uma simulação das curvas de decaimento radioativo utilizando conjuntos de poliedros (fÃsicos ou virtuais), onde cada conjunto é formado com poliedros com um determinado número de faces. Quando um átomo emite algum tipo de radiação é dito que o elemento quÃmico sofreu um decaimento radioativo e este processo, além de ser uma transmutação da matéria, é um processo espontâneo e completamente aleatório. O tempo médio em que metade dos átomos de uma certa amostra decaem, formando outro elemento quÃmico, conhecido como tempo de meia-vida, é especÃfico para cada elemento quÃmico radioativo e pode-se utilizar poliedros com números de faces diferentes para simular esta condição. A probabilidade de um átomo especÃfico decair após um certo perÃodo de tempo pode ser simulada comparando o lançamento dos poliedros subtraindo-se a quantidade de poliedros em função de uma das faces escolhidas
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