A preliminary Scanning Electron Microscope (SEM) study of magnetite surface microtextures from the Wahianoa moraines, Mt Ruapehu, New Zealand.

Scanning electron microscope (SEM) of quartz micro‐textures has routinely been used to identify the depositional environment of sediments in areas of former ice‐sheet glaciation. On volcanic mountains, where the geomorphic origin of ridge deposits is often poorly understood, quartz is much less abundant, so SEM analysis has not been used as a depositional discriminator. Preliminary research on surface micro‐textures of abundant magnetite grains from the Wahianoa moraines, south‐eastern Mt Ruapehu, suggests that SEM of magnetite may be useful in determining the process‐origin of deposits. We describe micro‐textures and surface characteristics of samples of magnetite, and our study shows that many of the micro‐textures visible on quartz, thought to be diagnostic of glacial transport, are present on magnetite too. However, evaluating whether SEM analysis of magnetite is an applicable technique will require a better understanding of the microtextures occurring on known glacial, fluvioglacial and aeolian deposits on volcanic mountains

Determining the Impact of Federal Antidiscrimination Policy on the Economic Status of Blacks: A Study of South Carolina

This paper assesses the contribution of federal antidiscrimination policy to the dramatic improvement of black economic status in manufacturing that occurred in South Carolina in the mid 1960's. Using a unique data source on wages and employment by race and sex in South Carolina we evaluate competing explanations. Human capital stories, supply shift stories and tight labor market stories do not account for the black breakthrough. Our study documents a significant contribution of federal antidiscrimination programs.

Constraining sub-grid physics with high-redshift spatially-resolved metallicity distributions

Aims. We examine the role of energy feedback in shaping the distribution of metals within cosmological hydrodynamical simulations of L* disc galaxies. While negative abundance gradients today provide a boundary condition for galaxy evolution models, in support of inside-out disc growth, empirical evidence as to whether abundance gradients steepen or flatten with time remains highly contradictory. Methods. We made use of a suite of L* discs, realised with and without "enhanced" feedback. All the simulations were produced using the smoothed particle hydrodynamics code Gasoline, and their in situ gas-phase metallicity gradients traced from redshift z similar to 2 to the present-day. Present-day age-metallicity relations and metallicity distribution functions were derived for each system. Results. The "enhanced" feedback models, which have been shown to be in agreement with a broad range of empirical scaling relations, distribute energy and re-cycled ISM material over large scales and predict the existence of relatively "flat" and temporally invariant abundance gradients. Enhanced feedback schemes reduce significantly the scatter in the local stellar age-metallicity relation and, especially, the [O/Fe]-[Fe/H] relation. The local [O/Fe] distribution functions for our L* discs show clear bimodality, with peaks at [O/Fe] = -0.05 and +0.05 (for stars with [Fe/H] > -1), consistent with our earlier work on dwarf discs. Conclusions. Our results with "enhanced" feedback are inconsistent with our earlier generation of simulations realised with "conservative" feedback. We conclude that spatially-resolved metallicity distributions, particularly at high-redshift, offer a unique and under-utilised constraint on the uncertain nature of stellar feedback processes

One Hour of Chemical Demonstrations

This article describes a diverse set of chemistry demonstrations especially selected to encourage student interaction and to be easily transported. The demonstrations may be presented at a level that can be tailored to any audience– from very young children to high school students planning careers in science. An ideal environment is a small classroom with 20-30 students where everyone can take part in the discussion. Once the chemicals are prepared, the collection of demonstrations takes about ten minutes to set-up, and one hour (or less) to perform. Very little is needed at the visiting site, no more than a table and a pitcher of water. A single electrical outlet is useful, but not essential. In Table 2 th

Influence of parental attitudes on substance consumption in adolescence

The aim of this quantitative cross-sectional study was to analyze the relationship between the perception of adolescents about their tendency to use psychoactive substances and their parents' attitudes. 487 Brazilian adolescents participated. For statistical analysis the Multinomial Logit Model was used, where the Stepwise method for selecting variables was applied. Tobacco, alcohol and marijuana were related to the variables of greatest influence on the use, abuse and dependence of these substances. Findings showed that an unloving father increases the possibility that the child becomes tobacco dependent (p = 0.001). An unloving mother is most likely to have a tobacco dependent child (p = 0.001). Father's control is a protective factor for experimenting with tobacco smoking (p = 0.023) and for marijuana dependence (p = 0.042). The relationship between substance consumption in adolescence and the perception young people have about their parents' attitudes was emphasized.El objetivo de este estudio transversal cuantitativo fue analizar la relación entre la percepción del adolescente sobre su tendencia al uso de sustancias psicoactivas y las actitudes de sus padres. Participaron 487 adolescentes brasileños. Para el análisis estadístico se utilizó el Modelo Logístico Multinomial, en el que se aplicaba el método Stepwise para la selección de variables. El tabaco, el alcohol y la marihuana se relacionaron con las variables de mayor influencia en el uso, abuso y dependencia. Se encontró que un padre poco cariñoso aumenta la posibilidad de que el niño sea dependiente del tabaco (p = 0.001), al igual que una madre poco afectuosa tiene más probabilidades de tener un hijo dependiente del tabaco (p = 0.001). El control del padre es un factor protector para la experimentación del tabaco (p = 0.023) y para la dependencia de la marihuana (p = 0.042). Se puso de relieve la relación entre el consumo de las drogas en la adolescencia y la percepción que los jóvenes tienen de las actitudes de sus padres.Este estudo transversal quantitativo objetivou analisar a relação entre a percepção do adolescente sobre as atitudes parentais e sua tendência ao uso de substâncias psicoativas. Participaram 487 adolescentes brasileiros. Para análise estatística foi utilizado o Modelo Logístico Multinomial, sobre o qual se aplicou o método Stepwise para seleção de variáveis. O tabaco, o álcool e a maconha foram relacionados com as variáveis de maior influência no uso, abuso ou dependência. Verificou-se que um pai pouco afetivo, aumenta a chance de o filho ser dependente de tabaco (p = 0.001). A mãe sendo pouco afetiva tem maior possibilidade de ter um filho dependente do tabaco (p = 0.001). O controle do pai é um fator protetivo para a experimentação do tabaco (p = 0.023) e para a dependência da maconha (p = 0.042). A relação entre o uso de drogas na adolescência e a percepção que o jovem tem das atitudes de seus pais ficou evidenciada

The role of beta-lactamase-producing-bacteria in mixed infections

Beta-lactamase-producing bacteria (BLPB) can play an important role in polymicrobial infections. They can have a direct pathogenic impact in causing the infection as well as an indirect effect through their ability to produce the enzyme beta-lactamase. BLPB may not only survive penicillin therapy but can also, as was demonstrated in in vitro and in vivo studies, protect other penicillin-susceptible bacteria from penicillin by releasing the free enzyme into their environment. This phenomenon occurs in upper respiratory tract, skin, soft tissue, surgical and other infections. The clinical, in vitro, and in vivo evidence supporting the role of these organisms in the increased failure rate of penicillin in eradication of these infections and the implication of that increased rate on the management of infections is discussed

Properties of simulated Milky Way-mass galaxies in loose group and field environments

We test the validity of comparing simulated field disk galaxies with the empirical properties of systems situated within environments more comparable to loose groups, including the Milky Way's Local Group. Cosmological simulations of Milky Way-mass galaxies have been realised in two different environment samples: in the field and in environments with similar properties to the Local Group. Apart from the environments of the galaxies, the samples are kept as homogeneous as possible with equivalent ranges in last major merger time, halo mass and halo spin. Comparison of these two samples allow for systematic differences in the simulations to be identified. Metallicity gradients, disk scale lengths, colours, magnitudes and age-velocity dispersion relations are studied for each galaxy in the suite and the strength of the link between these and environment of the galaxies is studied. The bulge-to-disk ratio of the galaxies show that these galaxies are less spheroid dominated than many other simulated galaxies in literature with the majority of both samples being disk dominated. We find that secular evolution and mergers dominate the spread of morphologies and metallicity gradients with no visible differences between the two environment samples. In contrast with this consistency in the two samples there is tentative evidence for a systematic difference in the velocity dispersion-age relations of galaxies in the different environments. Loose group galaxies appear to have more discrete steps in their velocity dispersion-age relations. We conclude that at the current resolution of cosmological galaxy simulations field environment galaxies are sufficiently similar to those in loose groups to be acceptable proxies for comparison with the Milky Way provided that a similar assembly history is considered.Comment: 16 pages, 11 figures, abstract abridged for arXiv. Accepted for publication in Astronomy & Astrophysic