Dynamo Action in the Solar Convection Zone and Tachocline: Pumping and Organization of Toroidal Fields

We present the first results from three-dimensional spherical shell simulations of magnetic dynamo action realized by turbulent convection penetrating downward into a tachocline of rotational shear. This permits us to assess several dynamical elements believed to be crucial to the operation of the solar global dynamo, variously involving differential rotation resulting from convection, magnetic pumping, and amplification of fields by stretching within the tachocline. The simulations reveal that strong axisymmetric toroidal magnetic fields (about 3000 G in strength) are realized within the lower stable layer, unlike in the convection zone where fluctuating fields are predominant. The toroidal fields in the stable layer possess a striking persistent antisymmetric parity, with fields in the northern hemisphere largely of opposite polarity to those in the southern hemisphere. The associated mean poloidal magnetic fields there have a clear dipolar geometry, but we have not yet observed any distinctive reversals or latitudinal propagation. The presence of these deep magnetic fields appears to stabilize the sense of mean fields produced by vigorous dynamo action in the bulk of the convection zone.Comment: 4 pages, 3 color figures (compressed), in press at ApJ

Suicides Among Farmers in Three Southeastern States, 1990-1998

Several studies have documented higher rates of suicide among farmers in comparison to other occupational groups, both in the U.S. and internationally. The purpose of this study is to describe the epidemiology of farmer suicides in three southeastern states (Kentucky, North Carolina, and South Carolina) during the nine-year period 1990-1998. Electronic death certificate data were obtained from the National Center for Health Statistics. Over the nine-year period, there were 590 deaths related to suicide (E-codes: 950-959) among farmers (occupation codes: 473, 474, 475, 477, and 479) in the states of Kentucky, North Carolina, and South Carolina. The results of this study confirm the increased rate of suicide mortality among white male farmers in comparison to the total white male population in these three southern states. The increased rate of suicide was significantly elevated among farmers age 25-34 years (RR: 2.07; 95% CI: 1.61-2.67) and among those age 75-84 (RR: 2.04; 95% CI: 1.70-2.45) and age 85 years and older (RR: 2.67; 95% CI: 2.02-3.54) in comparison to the total white male population.The use of a firearm was the primary mechanism of death for the majority (86%) of the cases. Farmer suicide mortality rates in the southeastern U.S. are higher than in Midwestern states. The elevated rate of white male farmer suicides in North Carolina over this time period (35% higher age-adjusted suicide rate in comparison to South Carolina) suggests a need for further investigation to assess the individual, social, and economic factors that may explain this elevated rate. Interventions for the prevention of suicide need to be directed to older male farmers who consistently have higher suicide rates than similar males in other occupations

Chronic arsenic exposure and risk of infant mortality in two areas of Chile.

Chronic arsenic exposure has been associated with a range of neurologic, vascular, dermatologic, and carcinogenic effects. However, limited research has been directed at the association of arsenic exposure and human reproductive health outcomes. The principal aim of this study was to investigate the trends in infant mortality between two geographic locations in Chile: Antofagasta, which has a well-documented history of arsenic exposure from naturally contaminated water, and Valparaíso, a comparable low-exposure city. The arsenic concentration in Antofagasta's public drinking water supply rose substantially in 1958 with the introduction of a new water source, and remained elevated until 1970. We used a retrospective study design to examine time and location patterns in infant mortality between 1950 and 1996, using univariate statistics, graphical techniques, and Poisson regression analysis. Results of the study document the general declines in late fetal and infant mortality over the study period in both locations. The data also indicate an elevation of the late fetal, neonatal, and postneonatal mortality rates for Antofagasta, relative to Valparaíso, for specific time periods, which generally coincide with the period of highest arsenic concentration in the drinking water of Antofagasta. Poisson regression analysis yielded an elevated and significant association between arsenic exposure and late fetal mortality [rate ratio (RR) = 1.7; 95% confidence interval (CI), 1.5-1.9], neonatal mortality (RR = 1.53; CI, 1.4-1.7), and postneonatal mortality (RR = 1.26; CI, 1.2-1.3) after adjustment for location and calendar time. The findings from this investigation may support a role for arsenic exposure in increasing the risk of late fetal and infant mortality

About Those New Oats - Burnett and Newton

These two new oat varieties will be available for planting in 1958. You can see them growing this year at Iowa State College or in the fields of certified seed producers. Here are the details on what you can expect

Time to question diabetes self-management support for Arabic-speaking migrants: exploring a new model of care

AIM: The objective of this study was to explore a new model for diabetes self-management support in Arabic-speaking migrants. METHODS: Two qualitative methods were used: face-to-face semi-structured individual interviews and focus groups. Interviews were audio-taped, transcribed verbatim and coded thematically. Arabic-speaking migrants with Type 2 diabetes were recruited from several primary, secondary and tertiary healthcare settings in metropolitan Melbourne, Australia. These settings were purposefully selected to obtain a diverse group of participants. Data collection continued until saturation was reached. This is the first study that involved members of Arabic-speaking communities in Australia in a formal process of consumer and public involvement to inform research design and recruitment in order to provide evidence for a new model of diabetes self-management for Arabic-speaking migrants. RESULTS: No self-management support was offered to Arabic-speaking migrants beyond the initial diagnosis period. Significant knowledge gaps and skills deficits in all self-management domains were evident. The provision of tailored self-management support was considered crucial. When asked about preferred structure and delivery modalities, a strong preference was reported for face-to-face storytelling interactions over telephone- or internet-based interventions. Gender-specific group education and self-management support sessions delivered by Arabic-speaking diabetes health professionals, lay peers or social workers trained in diabetes self-management were highly regarded. CONCLUSIONS: A patient and public involvement approach allows genuine engagement with Arabic-speaking migrants with diabetes. There is urgent need for a new model for self-management support among Arabic-speaking migrants. Findings yielded new recommendations for diabetes health professionals working with these migrant communities to support behaviour change

The atomic structure of large-angle grain boundaries Σ5\Sigma 5 and Σ13\Sigma 13 in YBa2Cu3O7−δ{\rm YBa_2Cu_3O_{7-\delta}} and their transport properties

We present the results of a computer simulation of the atomic structures of large-angle symmetrical tilt grain boundaries (GBs) $\Sigma 5$ (misorientation angles \q{36.87}{^{\circ}} and \q{53.13}{^{\circ}}), $\Sigma 13$ (misorientation angles \q{22.62}{^{\circ}} and \q{67.38}{^{\circ}}). The critical strain level $\epsilon_{crit}$ criterion (phenomenological criterion) of Chisholm and Pennycook is applied to the computer simulation data to estimate the thickness of the nonsuperconducting layer ${\rm h_n}$ enveloping the grain boundaries. The ${\rm h_n}$ is estimated also by a bond-valence-sum analysis. We propose that the phenomenological criterion is caused by the change of the bond lengths and valence of atoms in the GB structure on the atomic level. The macro- and micro- approaches become consistent if the $\epsilon_{crit}$ is greater than in earlier papers. It is predicted that the symmetrical tilt GB $\Sigma5$ \theta = \q{53.13}{^{\circ}} should demonstrate a largest critical current across the boundary.Comment: 10 pages, 2 figure

Education in the working-class home: modes of learning as revealed by nineteenth-century criminal records

The transmission of knowledge and skills within the working-class household greatly troubled social commentators and social policy experts during the first half of the nineteenth century. To prove theories which related criminality to failures in working-class up-bringing, experts and officials embarked upon an ambitious collection of data on incarcerated criminals at various penal institutions. One such institution was the County Gaol at Ipswich. The exceptionally detailed information that survives on families, literacy, education and apprenticeships of the men, women and children imprisoned there has the potential to transform our understanding of the nature of home schooling (broadly interpreted) amongst the working classes in nineteenth-century England. This article uses data sets from prison registers to chart both the incidence and ‘success’ of instruction in reading and writing within the domestic environment. In the process, it highlights the importance of schooling in working-class families, but also the potentially growing significance of the family in occupational training