Measurements are reported for the scattering of molecular oxygen with both a hot rotational energy distribution and cooled at its ground rotational state with a controlled alignment of the rotational angular momentum. The cooling and control of the alignment are achieved using supersonic expansion in beams of molecular oxygen seeded in various mixtures of Ne, He, and H2 and monitored by a Stern-Gerlach magnetic deflection technique. It is shown by the example of integral scattering cross section with Xe in the glory energy range that information can be obtained on the isotropic and anisotropic components of intermolecular van der Waals interactions.PACS numbers: 34.20. Gj, 34.50.s This Letter reports the first application to molecular scattering of a natural and facile technique for alignment of molecular rotations by seeded supersonic expansions of gaseous mixtures [1,2]. The seeding phenomenon provides a general way not only to molecular acceleration and cooling of the heavier components of the mixtures but also to polarization of their rotational angular momentum [1). This alignment has been found [2] to be drastically dependent on final speed: In the prototypical case of oxygen molecules diluted in mixtures with lighter gases such as H2, He, and Ne, cooling occurs down to the rotational ground state K = 1 and strongly nonstatistical distribution is observed for the rotational angular momentum projections along the propagation direction (helicities) M = 0 and 1 (either +1 or -1).We denote the relative number of molecules with M = 0 as wp. For them the rotational angular momentum is perpendicular to the propagation direction. The relative number of molecules pertaining to the other possibility, i.e. , corresponding to helicity M = 1, will be denoted as wlthis number is the same in both the +1 and -1 cases, which only differ by the sense of rotation, irrelevant under the axial symmetry of the molecular beam expansion. Alignment is conveniently measured by the ratio wo/wI, which is 1 in the statistical case (no alignment).It had been found [2] that, within a seeded supersonic expansion, fast molecules are much more highly aligned than slower ones and, specifically, states of zero helicity are strongly favored for those molecules that travel faster (wp/wi~1): Thus by changing the gas mixture and its composition we can prepare molecules with well-defined velocities and alignment ratios. Pictorially, zero helicity molecules can be considered as traveling edge-on and those with helicity M = 1 as traveling broadside towards a scatterer, and therefore an alignment control opens up the possibility of carrying out experiments with the aim of assessing the role of spatial aspects in the dynamics of atomic and molecular collisions.A demonstration of the potentiality of this novel technique is presented here for the case of experimental measurements for 02-Xe scattering with a controlled alignment ratio wo/wI, an outline is also given of the theoretical analysis for the extraction of information on the interaction from d...

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Waist circumference as an indicator of body fat and metabolic disorders in adolescents: a comparison of four criteria 665Rev Assoc Med Bras 2010; 56(6): 665-9 IntroductIonObesity is defined as excessive body fat and not only overweight. 1 This disorder is increasingly prevalent and in developed countries it is the most frequent pediatric disease. 2 In Brazil, from 1974 to 1997, overweight increased from 4.1% to 13.9% in children and adolescents 3 and it is estimated that 50%-77% of this age group will also have this condition in adulthood. 2 Additionally, excessive weight in childhood and adolescence contributes to a higher incidence of morbidity and mortality from cardiovascular causes in adulthood. 4 In adolescence, excess of body fat may be associated with several important metabolic disorders, such as dyslipidemia, hypertension, and hyperinsulinemia, which characterize the metabolic syndrome. 5 This association between obesity and metabolic syndrome is even stronger if there is abdominal or central adiposity. 6 This is alarming given that abdominal obesity has been increasing more than overall obesity (assessed by body mass index) among adolescents. 7,8 Recently, there has been an increase in the waist circumference of children and adolescents in the United Kingdom 7 and Spain. 8 In British children, increased waist was higher than BMI in the last 10-20 years, especially in girls. 7 In Zaragoza, Spain, waist circumference values showed an increasing trend in adolescents aged 13 to 14 years, from 1995 to 2000-2002, and

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