Contamination monitor

Optical measuring instrument flown on IMP satellite to monitor spacecraft contaminatio

Elastic response of the electron fluid in intrinsic graphene: The collisionless regime

The elastic response of an electron fluid at finite frequencies is defined by the electron viscosity $\eta(\omega)$. We determine $\eta(\omega)$ for graphene at the charge neutrality point in the collisionless regime, including the leading corrections due to the electron-electron Coulomb interaction. We find interaction corrections to $\eta(\omega)$ that are significantly larger if compared to the corresponding corrections to the optical conductivity. In addition, we find comparable contributions to the dynamic momentum flux due to single-particle and many-particle effects. We also demonstrate that $\eta(\omega)$ is directly related to the nonlocal energy-flow response of graphene at the Dirac point. The viscosity in the collisionless regime is determined with the help of the strain generators in the Kubo formalism. Here, the pseudo-spin of graphene describing its two sublattices plays an important role in obtaining a viscosity tensor that fulfills the symmetry properties of a rotationally symmetric system.Comment: 18 pages, 5 figure

The Private Military company-Unravelling the Theoretical, Legal & regulatory Mosaic

Our economic analysis has disclosed the fact that it is only the interests of competing cliques of business men-investors, contractors, export manufacturers, and certain professional classes-that are antagonistic; that these cliques, usurping the authority and voice of the people, use the public resources to push their private interests, and spend the blood and money of the people in this vast and disastrous military game, feigning national antagonisms which have no basis in reality. \u2

Suboptimal eye movements for seeing fine details.

Human eyes are never stable, even during attempts of maintaining gaze on a visual target. Considering transient response characteristics of retinal ganglion cells, a certain amount of motion of the eyes is required to efficiently encode information and to prevent neural adaptation. However, excessive motion of the eyes leads to insufficient exposure to the stimuli, which creates blur and reduces visual acuity. Normal miniature eye movements fall in between these extremes, but it is unclear if they are optimally tuned for seeing fine spatial details. We used a state-of-the-art retinal imaging technique with eye tracking to address this question. We sought to determine the optimal gain (stimulus/eye motion ratio) that corresponds to maximum performance in an orientation-discrimination task performed at the fovea. We found that miniature eye movements are tuned but may not be optimal for seeing fine spatial details

Fruit and vegetable sources among ethnic groups

Objectives: Data are limited on how dietary sources of food and nutrients differ among ethnic groups. The objective of this study was to determine the main sources of fruit, vegetables, and vitamins A, C, and E for five ethnic groups. Methods: Dietary data were collected using a validated quantitative food frequency questionnaire from participants in the Multiethnic Cohort in Hawaii and Los Angeles County between 1993 and 1996. Data were analyzed for 186,916 participants representing five ethnic groups; African Americans, Japanese Americans, Native Hawaiians, Latinos, and Caucasians. Results: Lettuce was the most consumed vegetable (6.0%-9.9%) in all ethnic-sex groups, except African American women and Mexican-born Latino men and women. Oranges and bananas contributed more than one quarter to total fruit intake among all groups. Overall, more ethnic variation in food choices was observed for the top ten vegetables than fruit. The top sources for vitamins A, C and E were carrots, orange/grapefruit/pomelo and combined dishes, respectively. Between micronutrients studied, the greatest ethnic variation in foods consumed was observed among the top ten food sources of vitamin A. Conclusions: This is the first study providing data on the main types of fruit and vegetables consumed and the major sources of vitamins A, C, and E among these ethnic groups in the U.S. Such data are valuable for developing and implementing public health strategies to meet the USDA dietary recommendations and guiding ethnic-specific nutrition education and intervention programs

Ethnic differences in grains consumption and their contribution to intake of B-vitamins: results of the Multiethnic Cohort Study

Background: Research indicates that a diet rich in whole grains may reduce the risk of prevalent chronic diseases, including cardiovascular disease, diabetes, and some cancers, and that risk for these diseases varies by ethnicity. The objective of the current study was to identify major dietary sources of grains and describe their contribution to B vitamins in five ethnic groups. Methods. A cross-sectional mail survey was used to collect data from participants in the Multiethnic Cohort Study in Hawaii and Los Angeles County, United States, from 1993 to 1996. Dietary intake data collected using a quantitative food frequency questionnaire was available for 186,916 participants representing five ethnic groups (African American, Latino, Japanese American, Native Hawaiian and Caucasian) aged 45-75 years. The top sources of grain foods were determined, and their contribution to thiamin, riboflavin, niacin, vitamin B6, and folic acid intakes were analyzed. Results: The top source of whole grains was whole wheat/rye bread for all ethnic-sex groups, followed by popcorn and cooked cereals, except for Native Hawaiian men and Japanese Americans, for whom brown/wild rice was the second top source; major contributors of refined grains were white rice and white bread, except for Latinos. Refined grain foods contributed more to grain consumption (27.1-55.6%) than whole grain foods (7.4-30.8%) among all ethnic-sex groups, except African American women. Grain foods made an important contribution to the intakes of thiamin (30.2-45.9%), riboflavin (23.1-29.2%), niacin (27.1-35.8%), vitamin B6 (22.9-27.5%), and folic acid (23.3-27.7%). Conclusions: This is the first study to document consumption of different grain sources and their contribution to B vitamins in five ethnic groups in the U.S. Findings can be used to assess unhealthful food choices, to guide dietary recommendations, and to help reduce risk of chronic diseases in these populations

The 'follow-through' experience in three-year Bachelor of Midwifery programs in Australia: A survey of students

Introduction: The follow-through experience in Australian midwifery education is a strategy that requires midwifery students to 'follow' a number of women through pregnancy, labour and birth and into the parenting period. Background: The experience was introduced by the Australian College of Midwives as part of national standards for the three-year Bachelor of Midwifery programs. Anecdotally, the introduction caused considerable debate. A criticism was that these experiences were incorporated with little evidence of their value. Methods: An online survey was undertaken to explore the follow-through experience from the perspectives of current and former students. There were 101 respondents, 93 current students with eight recent graduates. Results: Participants were positive about developing relationships with women. They also identified aspects of the follow-through experience that were challenging. Support to assist with the experience was often lacking and the documentation required varied. Despite these difficulties, 75% felt it should be mandatory as it facilitated positive learning experiences. Discussion: The follow-through experience ensured that students were exposed to midwifery continuity of care. The development of relationships with women was an important aspect of learning. Conclusion: Despite these challenges, there were significant learning opportunities. Future work and research needs to ensure than an integrated approach is taken to enhance learning. © 2012 Elsevier Ltd

Students' perceptions of the follow-through experience in 3 year bachelor of midwifery programmes in Australia

Background: providing opportunities for students to participate in midwifery continuity of care experiences is a challenge in many midwifery education programmes. The 'follow-through experience' was a deliberate strategy introduced into midwifery education programmes in Australia to ensure that students experienced midwifery continuity of care. The follow through experience provides an opportunity for midwifery students to follow a pre-determined number of women through pregnancy, labour and birth and into the early parenting period. Aim: the aim of this study was to explore the follow-through experience in the 3 year Bachelor of Midwifery (direct entry) in Australia to better understand its impact on midwifery students and to identify the learning that is associated with this experience. Methods: a qualitative methodology was used. Data were collected from former and current Bachelor of Midwifery students through a survey and telephone interviews. Students from all 3-year pre-registration Bachelor of Midwifery programmes in Australia were invited to participate. A thematic analysis was undertaken. Constructivist learning theories were used to identify whether learning occurred in the context of the follow-through experience. Findings: students do learn from their engagement in midwifery continuity of care experiences. Learning was characterised by the primacy of the relationship with the women. Students also identified the challenges they faced which included recruitment of women and finding the time to fully engage with the follow-through experience. Difficulties were identified around the different requirements of the follow-through experience, the lack of support at times for students and the incongruence with the existing maternity system. These issues impacted on students' ability to engage in and maximise their learning. Conclusions: the follow-through experience is an innovative midwifery education strategy that facilitates learning for midwifery students. Challenges need to be addressed at a systematic level and new strategies developed to support the learning opportunities presented by the follow-through experience. © 2012 Elsevier Ltd

Approximating Nearest Neighbor Distances

Several researchers proposed using non-Euclidean metrics on point sets in Euclidean space for clustering noisy data. Almost always, a distance function is desired that recognizes the closeness of the points in the same cluster, even if the Euclidean cluster diameter is large. Therefore, it is preferred to assign smaller costs to the paths that stay close to the input points. In this paper, we consider the most natural metric with this property, which we call the nearest neighbor metric. Given a point set P and a path $\gamma$, our metric charges each point of $\gamma$ with its distance to P. The total charge along $\gamma$ determines its nearest neighbor length, which is formally defined as the integral of the distance to the input points along the curve. We describe a $(3+\varepsilon)$-approximation algorithm and a $(1+\varepsilon)$-approximation algorithm to compute the nearest neighbor metric. Both approximation algorithms work in near-linear time. The former uses shortest paths on a sparse graph using only the input points. The latter uses a sparse sample of the ambient space, to find good approximate geodesic paths.Comment: corrected author nam