Search for an Ultralight Scalar Dark Matter Candidate with the AURIGA Detector.

A search for a new scalar field, called moduli, has been performed using the cryogenic resonant-mass AURIGA detector. Predicted by string theory, moduli may provide a significant contribution to the dark matter (DM) component of our Universe. If this is the case, the interaction of ordinary matter with the local DM moduli, forming the Galaxy halo, will cause an oscillation of solid bodies with a frequency corresponding to the mass of moduli. In the sensitive band of AURIGA, some 100 Hz at around 1 kHz, the expected signal, with Q=△f/f∼10^{6}, is a narrow peak, △f∼1 mHz. Here the detector strain sensitivity is h_{s}∼2×10^{-21} Hz^{-1/2}, within a factor of 2. These numbers translate to upper limits at 95% C.L. on the moduli coupling to ordinary matter (d_{e}+d_{m_{e}})≲10^{-5} around masses m_{ϕ}=3.6×10^{-12} eV, for the standard DM halo model with ρ_{DM}=0.3 GeV/cm^{3}.

Energy repartition for a harmonic chain with local reservoirs.

We exactly analyze the vibrational properties of a chain of harmonic oscillators in contact with local Langevin heat baths. Nonequilibrium steady-state fluctuations are found to be described by a set of mode temperatures, independent of the strengths of both the harmonic interaction and the viscous damping. Energy is equally distributed between the conjugate variables of a given mode but differently among different modes, in a manner which depends exclusively on the bath temperatures and on the boundary conditions. We outline how bath-temperature profiles can be designed to enhance or reduce fluctuations at specific frequencies in the power spectrum of the chain length.

Thermal noise of mechanical oscillators in steady states with a heat flux.

We present an experimental investigation of the statistical properties of the position fluctuations of low-loss oscillators in nonequilibrium steady states. The oscillators are coupled to a heat bath, and a nonequilibrium steady state is produced by flowing a constant heat flux, setting a temperature difference across the oscillators. We investigated the distribution of the measurements of the square of the oscillator position and searched for signs of changes with respect to the equilibrium case. We found that, after normalization by the mean value, the second, third, and fourth standardized statistical moments are not modified by the underlying thermodynamic state. This differs from the behavior of the absolute, i.e., not normalized, second moment, which is strongly affected by temperature gradients and heat fluxes. We illustrate this with a numerical experiment in which we study via molecular dynamics the fluctuations of the length of a one-dimensional chain of identical particles interacting via anharmonic interparticle potentials, with the extremes thermostated at different temperatures: we use the variance of the length in correspondence to its first elastic mode of resonance to define an effective temperature which we observe to depart from the thermodynamic one in the nonequilibrium states. We investigate the effect of changing the interparticle potential and show that the qualitative behavior of the nonequilibrium excess is unchanged. Our numerical results are consistent with the chain length being Gaussian distributed in the nonequilibrium states. Our experimental investigation reveals that the position variance is the only, and crucially easily accessible, observable for distinguishing equilibrium from nonequilibrium steady states. The consequences of this fact for the design of interferometric gravitational wave detectors are discussed.

Elasticity of mechanical oscillators in nonequilibrium steady states: experimental, numerical, and theoretical results.

We study experimentally, numerically, and theoretically the elastic response of mechanical resonators along which the temperature is not uniform, as a consequence of the onset of steady-state thermal gradients. Two experimental setups and designs are employed, both using low-loss materials. In both cases, we monitor the resonance frequencies of specific modes of vibration, as they vary along with variations of temperatures and of temperature differences. In one case, we consider the first longitudinal mode of vibration of an aluminum alloy resonator; in the other case, we consider the antisymmetric torsion modes of a silicon resonator. By defining the average temperature as the volume-weighted mean of the temperatures of the respective elastic sections, we find out that the elastic response of an object depends solely on it, regardless of whether a thermal gradient exists and, up to 10% imbalance, regardless of its magnitude. The numerical model employs a chain of anharmonic oscillators, with first- and second-neighbor interactions and temperature profiles satisfying Fourier's Law to a good degree. Its analysis confirms, for the most part, the experimental findings and it is explained theoretically from a statistical mechanics perspective with a loose notion of local equilibrium.

Estudo anatômico dos ossos do crânio no homem / Anatomic study of skull bones in man

Introdução: o crânio apresenta, às vezes, ossos supranumerários chamados ossos suturais ou wormianos. Normalmente irregulares em forma, tamanho e espessura. São encontrados no trajeto das suturas lambdóide e sagital, podendo as vezes também, apresentar-se nos lados do crânio, na base do crânio, na sutura entre o osso esfenóide e etmóide, raramente nas suturas da face. Objetivo: o propósito deste estudo foi analisar a forma e localização de ossos suturais em crânios humanos. Método: Foram analisados 35 crânios humanos, de uma amostra por conveniência, pertencente ao material preparado para estudos práticos no Laboratório de Anatomia Humana da USC, sendo feitos para cada caso, fotografias e desenhos esquemáticos para ilustração deste trabalho. Resultados: dos 35 crânios estudados, 14 (40 por cento) apresentavam ossos suturais. Dois casos (6 por cento) foram observados ossos interparietais e um caso (3 por cento) o osso interparietal apresentou-se bipartido. Em 12 (34 por cento) casos apresentavam ossos suturais laterais e medianos na região da sutura lambdóide. Observou-se um caso em que o osso occipital apresentou um forame anômalo e pequenos ossos suturais na sutura lambdóide. Conclusão: conhecimento desta variação é relevante para a anatomia humana, antropologia física, medicina forense, neuroanatomia, neurocirurgia,ortopedia, pediatria e radiologia.

IIntroduction: the skull presents, sometimes, extranumerary bones, called suture bones or wormians. Typically irregular in shape, size and thickness. They are found in the path of the lambdoid and sagittal sutures, and may, sometimes, also be present on the sides of the skull, on the skull base, on the suture between the ethmoid and sphenoid bone, rarely on the sutures of the face. Objective: the purpose of this study was to analyze the shape and location of sutural bones in human skulls. Methods: it was analyzed a group of 35 human skulls, of a convenience sample, from a prepared material used for practical studies at the Laboratory of Human Anatomy, USC, being made, for each case, photographs and schematic drawings to illustrate this paper. Results: from the 35 skulls studied, 14 (40 per cent) presented suture bones. Two cases (6 per cent) were observed interparietal bones and in one case (3 per cent), the interparietal bone presented bipartite. In 12 (34 per cent) cases had lateral and median sutural bones in the region of the lambdoid suture. It was observed a case in which the occipital bone presented an anomalous foramen and small sutural bones on the lambdoid suture. Conclusion: the knowledge of this variation is relevant for human anatomy, physical anthropology, forensic medicine, neuroanatomy, neurosurgery, orthopedics, pediatrics and radiology.

A compact, passive setup for low vibration noise measurements in the frequency band (300-2000) Hz.

In this paper we report about the setup we designed to isolate at about 1.5 kHz from mechanical noise an experimental payload of about 6.6 kg mass. We discuss the design guidelines and optimization by finite element analysis and we characterize the suspension performance by experimental measurements. While providing an attenuation of about 180 dB in all spatial directions at 1.5 kHz, our passive system is very compact and can be easily replicated whenever the need of a volume of few liters with very low vibration noise level in the 1-2 kHz range is needed.

A obesidade infanto-juvenil e seu impacto da infância à vida adulta: uma revisão da literatura científica no período de 1997-2007 / The child-adolescent obesity and the impact from childhood to adult life: a systematic review of scientific literature in the period 1997-2007

Objetivos: O artigo objetiva identificar as consequências da obesidade infanto-juvenil, tanto na infância quanto na vida adulta, a partir de uma revisão sistemática com base na literatura médica atual. Fontes pesquisadas: Realizouse uma pesquisa bibliográfica às bases de dados MEDLINE, LILACS e Portal de Periódicos Capes , selecionando-se artigos publicados no período de 1997 a 2007. O principal critério de inclusão foi a presença de estudos que abordassemo impacto da obesidade infanto-juvenil da infância à vida adulta. Síntese dos dados: Nos resultados, a obesidade foi relacionada aos aspectos familiares, socioeconômicos, relativos a faixa etária, gênero e características constitucionais. Por fim, avaliou se o impacto dessa morbidade na saúde pública, evidenciando o aumento dos custos relacionados ao excesso de peso...

Objectives: This review purpose to identify the consequences of the child-adolescent obesity as in the childhood as in the adulthood from a systematic review based in the recent medical literature. Data source: A bibliography search was performed on MEDLINE, LILACS, and Capes Periodical Portal databases published between 1997 and 2007. The main inclusion criterion was the presence of studies which involves child-adolescent obesity impact from infancy to adulthood. Data synthesis: The results associate the obesity with genetics, socioeconomics, age and gender aspects. At last, we evaluate the impact of this disease in public health showing that the costs increase when related to overweight...