Measured Quantum Dynamics of a Trapped Ion

The measurement process is taken into account in the dynamics of trapped ions prepared in nonclassical motional states. The induced decoherence is shown to manifest itself both in the inhibition of the internal population dynamics and in a damping of the vibrational motion without classical counterpart. Quantitative comparison with present experimental capabilities is discussed, leading to a proposal for the verification of the predicted effects.Comment: 5 Pages, no figures; Plain REVTeX; to be published in the 1st May issue of Phys. Rev. A, Rap. Commun. (1997

Mean-field criticality explained by random matrices theory

How a system initially at infinite temperature responds when suddenly placed at finite temperatures is a way to check the existence of phase transitions. It has been shown in [R. da Silva, IJMPC 2023] that phase transitions are imprinted in the spectra of matrices built from time evolutions of magnetization of spin models. In this paper, we show that this method works very accurately in determining the critical temperature in the mean-field Ising model. We show that for Glauber or Metropolis dynamics, the average eigenvalue has a minimum at the critical temperature, which is corroborated by an inflection at eigenvalue dispersion at this same point. Such transition is governed by a gap in the density of eigenvalues similar to short-range spin systems. We conclude that the thermodynamics of this mean-field system can be described by the fluctuations in the spectra of Wishart matrices which suggests a direct relationship between thermodynamic fluctuations and spectral fluctuations.Comment: 14 pages, 4 figure

Temporal overlap and co-occurrence in a guild of sub-tropical tephritid fruit flies

Studies of community assembly have emphasized snapshot comparisons of spatially replicated samples from natural assemblages. Agro-ecosystems are characterized by relatively little habitat heterogeneity and no dispersal barriers for actively flying insects. Therefore, dynamic patterns of species segregation and aggregation are more likely to reflect the direct or indirect effects of species interactions. We studied the temporal organization of a guild of 21 congeneric species of Anastrepha that colonized fruit orchards in Monte Alegre do Sul, São Paulo, Brazil. This assemblage also included the introduced Mediterranean fruit fly Ceratitis capitata. One hundred six consecutive weekly censuses (11 Jan 2002-16 Jan 2004) of flies in guava, loquat, and peach orchards revealed a pattern of minimum abundance during the coldest months of each year (June and July) and a maximum abundance during periods of flowering and fruit ripening. Overall, phenological overlap was greater than expected by chance. However, conditioned on the pattern of seasonal abundances, temporal occurrence and abundance matrices exhibited patterns of significant species segregation and anti-nestedness. In each year, the 3 orchards contained a small number of species pairs that exhibited statistically significant temporal segregation or aggregation. Most aggregated and segregated pairs reflected seasonal shifts in species presences that were not related to variation in air temperature. Most of the significant pairwise associations involved C. capitata: 8 of the 11 segregated pairs and 2 of the 7 aggregated pairs. These results suggest that species interactions between introduced and native species can be an important determinant of species associations in agro-ecosystems

Hemocromatose hereditária relato de caso e revisão da literatura

-Racional — A hemocromatose hereditária associada ao gene HFE é a doença hepática hereditária mais comum nas populações caucasianas e refere-se à associação de estoques aumentados de ferro com um dano tissular progressivo (como por exemplo, cirrose hepática, diabetes mellitus, cardiomiopatia), quando o diagnóstico e o tratamento são tardios. Objetivos - É apresentado o caso de uma paciente de 44 anos portadora de hemocromatose hereditária assintomática, cujo diagnóstico foi feito a partir da detecção casual de alterações na cinética do ferro. Apresenta-se, também, uma breve revisão da literatura sobre a doença. Conclusão - A existência de métodos diagnósticos capazes de identificar a doença antes que surjam suas complicações e a possibilidade de terapêutica efetiva que permita evitar as suas manifestações, tornam a hemocromatose hereditária entidade ideal para profilaxia primária, alterando completamente a sua história natural

Sobrevivência e crescimento de plantas de eucalipto provenientes de diferentes recipientes, em um sistema silvipastoril, em Campo Grande, MS.

Sistemas Silvipastoris são formas de uso do solo onde espécies lenhosas são adicionadas ao sistema de produção animal, em alguma forma de arranjo temporal ou espacial gerando produção de forma complementar pela interação dos seus componentes. Realizou-se um experimento, na Embrapa Gado de Corte, em Campo Grande, MS, onde plantaram-se mudas de eucalipto Urocam (E. urophyla x E. camaldulensis) e E. citriodora, produzidas em tubetes de 50 mL e após três meses transplantadas para recipientes com volume de 300, 600, 1.200 e 2.400 mL, contendo substrato Plantmax ®, considerando cada tamanho de recipiente, um tratamento, dispostos em um delineamento de blocos casualizados, em esquema fatorial de 2 x 4 (espécies x recipientes), totalizando oito tratamentos divididos em quatro blocos, cada um deles contendo uma parcela de nove plantas de cada tratamento. Avaliou-se, por 15 meses, altura da planta e diâmetro do colo e registrou-se a sobrevivência aos 30 dias, de quando efetuou-se o replantio e no 15º mês. Os maiores índices de sobrevivência da espécie E. citriodora foram registrados nas mudas provenientes do recipiente de 600 mL, seguido pelos de 1.200, 2.400 e 300 mL, tanto no 30º dia quanto no 15º mês. Para E. urocam, o recipiente de 1.200 mL forneceu mudas com maior sobrevivência tanto aos 30 dias quanto no 15º mês. Os dados obtidos evidenciam que o plantio de mudas de E. urocam com maior porte é viável e pode reduzir o tempo de isolamento na área.Tema 1: Desenho, implantação e manejo. 01Tema51

A functional variant of the myeloperoxidase gene is associated with cardiovascular disease in end-stage renal disease patients

A functional variant of the myeloperoxidase gene is associated with cardiovascular disease in end-stage renal disease patients. Cardiovascular disease (CVD) is the leading cause of mortality in end-stage renal disease (ESRD) patients and there is emerging evidence that genetic factors may contribute to the development of atherosclerosis. Myeloperoxidase (MPO) is an abundant enzyme involved in the production of free radicals. A functional G→A single nucleotide polymorphism (SNP) has been identified at position -463, where the A allele is associated with lower MPO expression. To analyze the association between this SNP and inflammation, oxidative stress, and CVD, we studied a cohort of 155 ESRD patients (52 ± 1 years, 62% males, 22% diabetics) shortly before the initiation of dialysis treatment. CVD was defined by medical history criteria; plasma interleukin-6 (IL-6) was used as a marker of inflammation, and plasma pentosidine as an estimation of oxidative protein damage. DNA from leukocytes was used for genotyping, performed by the pyrosequencing reaction. Only five patients (3%) had the genotype AA at the -463 position, whereas 38 (25%) had the GA and 112 (72%) had the GG genotype. No differences were noted in plasma IL-6 levels between the genotype groups, whereas the pentosidine levels were higher in the GG group (28.4 pmol/mg albumin [range, 8.5 to 123 pmol/mg albumin]) compared to the other two groups (21.4 pmol/mg albumin [range, 7.6 to 384 pmol/mg albumin; P < 0.05]). Patients with the GG genotype had a higher prevalence of positive serology for Chlamydia pneumoniae (51%) when compared to the carriers of the A allele (24%) (P < 0.05). The prevalence of CVD was lower in the AA (0%) and GA genotypes (18%), compared to the GG genotype (35%). The GG genotype was still associated with CVD after correction for age, diabetes, smoking, malnutrition, and inflammation. Our findings suggest that the -463 G→A SNP, which supposedly results in lower MPO activity, is associated with a lower prevalence of CVD in ESRD patients. It could be speculated that this effect is mediated by a decreased oxidative stress due to lower production of free radicals