Large change in the predicted number of small halos due to a small amplitude oscillating inflaton potential

A smooth inflaton potential is generally assumed when calculating the primordial power spectrum, implicitly assuming that a very small oscillation in the inflaton potential creates a negligible change in the predicted halo mass function. We show that this is not true. We find that a small oscillating perturbation in the inflaton potential in the slow-roll regime can alter significantly the predicted number of small halos. A class of models derived from supergravity theories gives rise to inflaton potentials with a large number of steps and many trans-Planckian effects may generate oscillations in the primordial power spectrum. The potentials we study are the simple quadratic (chaotic inflation) potential with superimposed small oscillations for small field values. Without leaving the slow-roll regime, we find that for a wide choice of parameters, the predicted number of halos change appreciably. For the oscillations beginning in the 10(7)-10(8) M(circle dot) range, for example, we find that only a 5% change in the amplitude of the chaotic potential causes a 50% suppression of the number of halos for masses between 10(7)-10(8) M(circle dot) and an increase in the number of halos for masses <10(6) M(circle dot) by factors similar to 15-50. We suggest that this might be a solution to the problem of the lack of observed dwarf galaxies in the range 10(7)-10(8) M(circle dot). This might also be a solution to the reionization problem where a very large number of Population III stars in low mass halos are required.

Treatment with a p38 MAPK inhibitor attenuates cisplatin nephrotoxicity starting after the beginning of renal damage

Aims: Cisplatin (CP) promotes increased production of reactive oxygen species, which can activate p38 mitogen activated protein kinases (p38 MAPKs) leading to apoptosis and increased expression of proinflammatory mediators that intensify the cytotoxic effects of CP. We investigated the effect of the treatment with S13203580, a p38 MAPKs inhibitor, on oxidative stress, on the oxidation-associated signal, p38 MAPK and on apoptosis in U-injected rats, starting after the beginning of the renal damage. Main methods: Rats (n = 21) were injected with CP (5 mg/kg, i.p.) and 3 and 4 days after some of them (n = 8) were treated with SB203580 (0.5 mg/kg, i.p.). Controls (n = 6) received saline (i.p.). Two or five days after saline or CP injections, plasma creatinine, urinary volume, sodium and potassium fractional excretions, blood urea nitrogen and urinary lipid peroxidation were measured. The kidneys were removed for histological, apoptosis, immunohistochemical and Western blot studies. Key findings: CP caused abnormalities in kidney functions and structure associated with raised urinary peroxidation levels and higher number of apoptotic cells in the outer medulla. The immunostaining studies showed increased numbers of macrophages/monocytes and p-p38 MAPKs positive cells in the renal outer medulla. The increase of p-p38 MAPKs expression was confirmed by Western blot analysis. All of these alterations were attenuated by treatment with S13203580. Significance: These data suggest that the beneficial effect of SB203580 on CP-induced renal damage might be related, in part, to the blockade of p38 MAPK activation with reduction of the inflammatory process, oxidative stress and apoptotic cell death. (C) 2009 Elsevier Inc. All rights reserved.

Relationship among malocclusion, number of occlusal pairs and mastication

This study evaluated the relationship among malocclusion, number of occlusal pairs, masticatory performance, masticatory time and masticatory ability in completely dentate subjects. Eighty healthy subjects (mean age = 19.40 ± 4.14 years) were grouped according to malocclusion diagnosis (n = 16): Class I, Class Class II-2, Class III and Normocclusion (control). Number of occlusal pairs was determined clinically. Masticatory performance was evaluated by the sieving method, and the time used for the comminute test food was registered as the masticatory time. Masticatory ability was measured by a dichotomic self-perception questionnaire. Statistical analysis was done by one-way ANOVA, ANOVA on ranks, Chi-Square and Spearman tests. Class II-1 and III malocclusion groups presented a smaller number of occlusal pairs than Normocclusion (p < 0.0001), Class I (p < 0.001) and II-2 (p < 0.0001) malocclusion groups. Class I, and III malocclusion groups showed lower masticatory performance values compared to Normocclusion (p < 0.05) and Class II-2 (p < 0.05) malocclusion groups. There were no differences in masticatory time (p = 0.156) and ability (χ2 = 3.58/p= 0.465) among groups. Occlusal pairs were associated with malocclusion (rho = 0.444/p < 0.0001) and masticatory performance (rho = 0.393/p < 0.0001), but malocclusion was not correlated with masticatory performance (rho = 0.116/p= 0.306). In conclusion, masticatory performance and ability were not related to malocclusion, and subjects with Class I, II-1 and III malocclusions presented lower masticatory performance because of their smaller number of occlusal pairs.

Efeitos da administração de monensina por meio de cápsulas de liberação controlada no desempenho de vacas Holandesas no início da lactação

Com o objetivo de estudar o efeito da monensina sobre a produção e composição de leite, a contagem de células somáticas, a condição corporal e os parâmetros sangüíneos e reprodutivos de vacas da raça Holandesa de alta produção no início de lactação, foram utilizadas 44 vacas com produção diária de 33,44 ± 4,93 litros de leite, em delineamento inteiramente casualizado, com dois tratamentos: um controle (C) e outro com cápsulas de liberação controlada de monensina com eficácia de 100 dias (300 mg/vaca/dia). A administração individual de monensina foi realizada 30 dias antes da data provável do parto. A monensina não alterou a produção, a composição do leite e a contagem de células somáticas do leite nem a condição corporal e a concentração de glicose e BHBA (beta-hidroxibutirato) no soro das vacas, no entanto, diminuiu a concentração de AGNE (ácidos graxos não-esterificados) no soro das vacas com 60 dias de lactação. O período de serviço e o número de serviços por concepção não diferiram entre os tratamentos, porém, a administração de monensina diminuiu o número de animais que apresentaram retenção de placenta e laminite. A administração de monensina para vacas Holandesas de alta produção no início de lactação não modifica a produção e a composição do leite, contudo, diminui a concentração de AGNE 60 dias após o parto e a incidência de laminite e retenção de placenta nas vacas no pós-parto.

Two-dimensional gel electrophoretic protein profile analysis during seed development of Ocotea catharinensis: a recalcitrant seed species

The aim of the present work was to characterize changes in the protein profile throughout seed development in O. catharinensis, a recalcitrant species, by two-dimensional gel electrophoresis. Protein extraction was undertaken by using a thiourea/urea buffer, followed by a precipitation step with 10% TCA. Comparative analysis during seed development showed that a large number of proteins were exclusively detected in each developmental stage. The cotyledonary stage, which represents the transition phase between embryogenesis and the beginning of metabolism related to maturation, presents the highest number of stage-specific spots. Protein identification, through MS/MS analysis, resulted in the identification of proteins mainly related to oxidative metabolism and storage synthesis. These findings contribute to a better understanding of protein metabolism during seed development in recalcitrant seeds, besides providing information on established markers that could be useful in defining and improving somatic embryogenesis protocols, besides monitoring the development of somatic embryos in this species.

An analytical solution for the critical number of particles for stable bose-einstein condensation under the influence of an anisotropic potential

We have considered a Bose gas in an anisotropic potential. Applying the the Gross-Pitaevskii Equation (GPE) for a confined dilute atomic gas, we have used the methods of optimized perturbation theory and self-similar root approximants, to obtain an analytical formula for the critical number of particles as a function of the anisotropy parameter for the potential. The spectrum of the GPE is also discussed.

Interações entre evolução sedimentar e ocupação humana pré-histórica na costa centro-sul de Santa Catarina, Brasil

Desde o começo da ocupação humana no litoral centro-sul de Santa Catarina, Brasil, a articulação entre processos naturais e antrópicos modelou uma paisagem fortemente domesticada, marcada pela construção massiva de concheiros de dimensões monumentais e pela permanência milenar. Na planície costeira entre Passagem da Barra (município de Laguna) e lago Figueirinha (município de Jaguaruna), 76 sambaquis foram mapeados, dos quais 48 possuem datação. O levantamento sistemático de sítios e datações permitiu identificar padrões de distribuição espacial nos sambaquis da região, quanto a contexto sedimentar da época de construção, estratigrafia e idade. Desse modo, reconheceram-se nos sítios da região: cinco contextos geológico-geomorfológicos de localização; três padrões estratigráficos; e quatro fases de ocupação sambaquieira baseadas na quantidade de sítios e no tipo de padrão construtivo dominante. O modelo integrado de evolução sedimentar e distribuição tempo-espacial de sambaquis indica que estes sítios eram construídos em áreas já emersas e pouco alagáveis, e que sítios interiores, afastados dos corpos lagunares, podem não se ter preservado ou não estarem expostos devido ao processo de assoreamento contínuo que caracterizou a região após a máxima transgressão holocênica. O cruzamento de dados aqui proposto evidencia a importância de abordagens integradas entre arqueologia e geociências no estudo da evolução das paisagens.

Violência contra idosos: uma questão nova?

O envelhecimento da população mundial é um fato concreto e de conhecimento público. O Brasil inicia seu processo de transição demográfica seguindo o padrão mundial: o aumento do número de idosos com possibilidade de atingir elevadas faixas etárias, o que traz a necessidade de pesquisas nesse campo, devido à demanda apresentada por essa nova parcela da população. A questão da violência doméstica contra idosos tem se ampliado e sugere necessidade de maior campo de investigação nessa área, dado o risco suposto ao qual essa população mais idosa está submetida. O objetivo deste artigo é verificar os estudos relacionados ao tema já realizados no Brasil e em diferentes países, com enfoque epidemiológico. O trabalho apresenta diversos pontos de abordagem da violência contra idosos, considerando questões relacionadas à cultura do envelhecimento, ações de políticas públicas, atuação de equipes de saúde, definição do termo abordado, aspectos legais e éticos da violência contra o idoso. Tal estudo permite ao pesquisador analisar os diferentes aspectos que envolvem a temática, demonstrando a necessidade de pesquisas específicas direcionadas ao tema.

Within- and between-person variations as determinant factors to calculate the number of observations to estimate usual dietary intake of adolescents

This cross-sectional study describes the variation in the dietary intake of energy and macronutrients based on estimated coefficients of within- and between-person variation and intends to calculate the number of days required to evaluate the dietary intake of adolescents in Piracicaba, Brazil. The sample was made up by ninety-two adolescents aged between eleven and sixteen years. Interviews were performed to assess demographic, anthropometric and dietary variables, which were evaluated by the answers obtained through two 24-hour recalls. Descriptive analyses were performed and variances and Coefficients of variation within- and between-person were obtained by results of one-way ANOVA. The mean energy intake observed was 2,326.2 kilocalories; mean macronutrient intake came to 89.0 grams of fatty acids, 305.3 grams of carbohydrates and 82.2 grams of proteins. Coefficients of within-person variation ranged from 36% to 45%, while between-person coefficients varied from 26% to 31%. Variance ratios ranged from 1.35 (carbohydrate) to 2.62 (protein). The lowest number of observations required to correctly evaluate the usual diet calculated (r = 0.90) was six days, for carbohydrates while the highest was eleven, for proteins. Coefficients of variation were similar to those observed in international studies. We conclude that, in this study, two observations were sufficient to obtain reasonable correlations. However, six evaluations are necessary for these adolescents in order to obtain excellent correlations.

Imagem por ressonância magnética na investigação da cabeça de cães

A imagem por ressonância magnética (IRM) é o método de diagnóstico por imagem não invasivo mais sensível para avaliar as partes moles, particularmente o encéfalo, porém trata-se de uma técnica onerosa. O método fundamenta-se no fenômeno da ressonância magnética nuclear que ocorre quando núcleos atômicos com propriedades magnéticas presentes no corpo são submetidos a um campo magnético intenso, sendo posteriormente excitados por energia de radiofrequência e gerando, por sua vez, um sinal de onda de radiofrequência capaz de ser captado por uma antena receptora, passando por um processo matemático, chamado Transformada de Fourier, para posterior formação da imagem. Esse estudo objetivou realizar 10 exames completos da cabeça em cadáveres de cães normais à IRM e confeccionar um Atlas com as estruturas identificadas. As imagens foram adquiridas em um aparelho de ressonância magnética Gyroscan S15/HP Philips com campo magnético de 1,5Tesla. Os cadáveres foram posicionados com a cabeça no interior de uma bobina de cabeça humana e foram submetidos a cortes iniciais sagitais a partir de onde se planejou os cortes transversais e dorsais nas sequências de pulso spin-eco T1, T2 e DP. Em T1 utilizou-se TR=400ms e TE=30ms, T2 utilizou-se TR=2000ms e TE=80ms e na DP utilizou-se TR=2000ms e TE=30ms. A espessura do corte foi de 4mm, o número de médias foi igual a 2, a matriz foi de 256x256, o fator foi igual a 1,0 e o campo de visão foi de 14cm. A duração do exame completo da cabeça foi de 74,5minutos. As imagens obtidas com as sequências utilizadas e com a bobina de cabeça humana foram de boa qualidade. Em T1 a gordura tornou-se hiperintensa e o líquido hipointenso. Em T2 a gordura ficou menos hiperintensa e o líquido hiperintenso. A cortical óssea e o ar foram hipointensos em todas as sequências utilizadas devido a baixa densidade de prótons. A sequência DP mostrou o melhor contraste entre a substância branca e cinzenta quando comparada a T2 e a T1. T2 evidenciou o líquido cefalorraquidiano tornando possível a distinção dos sulcos e giros cerebrais. Através do exame de IRM foi possível, pelo contraste, identificar as estruturas ósseas componentes da arquitetura da região, músculos, grandes vasos venosos e arteriais e estruturas do sistema nervoso central, além de elementos do sistema digestório, respiratório e estruturas dos olhos entre outras. Nesse estudo as IRM adquiridas nas sequências T1, DP e T2 foram complementares para o estudo dos aspectos anatômicos da cabeça de cães demonstrando-os com riqueza de detalhes. O tempo requerido para o exame completo da cabeça é compátivel para uso em animais vivos desde que devidamente anestesiados e controlados. Os resultados obtidos por esse trabalho abrem caminho em nosso meio, para o estudo de animais vivos e para o início da investigação de doenças, principalmente as de origem neurológica, visto ser esta técnica excelente para a visibilização do encéfalo.

Fully Connected PLL Networks: How Filter Determines the Number of Nodes

Synchronization plays an important role in telecommunication systems, integrated circuits, and automation systems. Formerly, the masterslave synchronization strategy was used in the great majority of cases due to its reliability and simplicity. Recently, with the wireless networks development, and with the increase of the operation frequency of integrated circuits, the decentralized clock distribution strategies are gaining importance. Consequently, fully connected clock distribution systems with nodes composed of phase-locked loops (PLLs) appear as a convenient engineering solution. In this work, the stability of the synchronous state of these networks is studied in two relevant situations: when the node filters are first-order lag-lead low-pass or when the node filters are second-order low-pass. For first-order filters, the synchronous state of the network shows to be stable for any number of nodes. For second-order filter, there is a superior limit for the number of nodes, depending on the PLL parameters. Copyright (C) 2009 Atila Madureira Bueno et al.

Confronting dark energy models using galaxy cluster number counts

The mass function of cluster-size halos and their redshift distribution are computed for 12 distinct accelerating cosmological scenarios and confronted to the predictions of the conventional flat Lambda CDM model. The comparison with Lambda CDM is performed by a two-step process. First, we determine the free parameters of all models through a joint analysis involving the latest cosmological data, using supernovae type Ia, the cosmic microwave background shift parameter, and baryon acoustic oscillations. Apart from a braneworld inspired cosmology, it is found that the derived Hubble relation of the remaining models reproduces the Lambda CDM results approximately with the same degree of statistical confidence. Second, in order to attempt to distinguish the different dark energy models from the expectations of Lambda CDM, we analyze the predicted cluster-size halo redshift distribution on the basis of two future cluster surveys: (i) an X-ray survey based on the eROSITA satellite, and (ii) a Sunayev-Zeldovich survey based on the South Pole Telescope. As a result, we find that the predictions of 8 out of 12 dark energy models can be clearly distinguished from the Lambda CDM cosmology, while the predictions of 4 models are statistically equivalent to those of the Lambda CDM model, as far as the expected cluster mass function and redshift distribution are concerned. The present analysis suggests that such a technique appears to be very competitive to independent tests probing the late time evolution of the Universe and the associated dark energy effects.

Pollen foraging in colonies of Melipona bicolor (Apidae, Meliponini): effects of season, colony size and queen number

We evaluated the ratio between the number of pollen foragers and the total number of bees entering colonies of Melipona bicolor, a facultative polygynous species of stingless bees. The variables considered in our analysis were: seasonality, colony size and the number of physogastric queens in each colony. The pollen forager ratios varied significantly between seasons; the ratio was higher in winter than in summer. However, colony size and number of queens per colony had no significant effect. We conclude that seasonal differences in pollen harvest are related to the production of sexuals and to the number of individuals and their body size.

The number of reproductive workers in highly eusocial Hymenoptera: monogyny and monandry

Haplodiploidy results in relatedness asymmetries between colony members of highly eusocial Hymenoptera. As a consequence, queen and reproductive workers are more related to their own sons than to each other's male offspring. Kin selection theory predicts multiple optima in male parentage: either the queen or the workers should produce all the males. Nevertheless, shared male parentage is common in highly eusocial hymenopterans. An inclusive fitness model was used to analyze the effect of the number of reproductive workers on male parentage shared by the queen and laying workers by isolating the male component from an inclusive fitness equation using the equal fitness through male condition for each pairwise combination of the three female classes comprised of the queen, laying workers and non-laying workers. The main result of the theoretical analyses showed that the fraction of males produced by workers increases asymptotically with the number of laying workers at an increasingly diminishing rate, tending to an asymptotic value of 0.67. In addition, as the number of laying workers increases, the share of male parentage converges to that of non-laying workers. The diminishing return effect on male parentage share depending on the number of reproductive workers leads us to expect the number of reproductive workers to be relatively small in a stingless bee colony, even in the absence of productivity costs. The available data confirms this hypothesis, as there is an unusually small number of reproductive workers in stingless bee colonies.

A comparison of dry and wet season aerosol number fluxes over the Amazon rain forest

Vertical number fluxes of aerosol particles and vertical fluxes of CO(2) were measured with the eddy covariance method at the top of a 53 m high tower in the Amazon rain forest as part of the LBA (The Large Scale Biosphere Atmosphere Experiment in Amazonia) experiment. The observed aerosol number fluxes included particles with sizes down to 10 nm in diameter. The measurements were carried out during the wet and dry season in 2008. In this study focus is on the dry season aerosol fluxes, with significant influence from biomass burning, and these are compared with aerosol fluxes measured during the wet season. Net particle deposition fluxes dominated in daytime in both seasons and the deposition flux was considerably larger in the dry season due to the much higher dry season particle concentration. The particle transfer velocity increased linearly with increasing friction velocity in both seasons. The difference in transfer velocity between the two seasons was small, indicating that the seasonal change in aerosol number size distribution is not enough for causing any significant change in deposition velocity. In general, particle transfer velocities in this study are low compared to studies over boreal forests. The reasons are probably the high percentage of accumulation mode particles and the low percentage of nucleation mode particles in the Amazon boundary layer, both in the dry and wet season, and low wind speeds in the tropics compared to the midlatitudes. In the dry season, nocturnal particle fluxes behaved very similar to the nocturnal CO(2) fluxes. Throughout the night, the measured particle flux at the top of the tower was close to zero, but early in the morning there was an upward particle flux peak that is not likely a result of entrainment or local pollution. It is possible that these morning upward particle fluxes are associated with emission of primary biogenic particles from the rain forest. Emitted particles may be stored within the canopy during stable conditions at nighttime, similarly to CO(2), and being released from the canopy when conditions become more turbulent in the morning.