Extracting Radial Velocities of A- and B-type Stars from Echelle Spectrograph Calibration Spectra

We present a technique to extract radial velocity measurements from echelle spectrograph observations of rapidly rotating stars ($V\sin{i} \gtrsim 50$ km s$^{-1}$). This type of measurement is difficult because the line widths of such stars are often comparable to the width of a single echelle order. To compensate for the scarcity of lines and Doppler information content, we have developed a process that forward-models the observations, fitting the radial velocity shift of the star for all echelle orders simultaneously with the echelle blaze function. We use our technique to extract radial velocity measurements from a sample of rapidly rotating A- and B-type stars used as calibrator stars observed by the California Planet Survey observations. We measure absolute radial velocities with a precision ranging from 0.5-2.0 km s$^{-1}$ per epoch for more than 100 A- and B-type stars. In our sample of 10 well-sampled stars with radial velocity scatter in excess of their measurement uncertainties, three of these are single-lined binaries with long observational baselines. From this subsample, we present detections of two previously unknown spectroscopic binaries and one known astrometric system. Our technique will be useful in measuring or placing upper limits on the masses of sub-stellar companions discovered by wide-field transit surveys, and conducting future spectroscopic binarity surveys and Galactic space-motion studies of massive and/or young, rapidly-rotating stars.Comment: Accepted to ApJ

The Roberts Court and Oral Arguments: A First Decade Retrospective

This Article summarizes some prominent data points of the Roberts Court justices’ behavior during oral arguments at the Supreme Court. Johnson relays accounts from observers who have recognized an increase in questioning from the justices during oral arguments. The Articles suggests this increase may be attributed to the more talkative style of newer justices, as well as the changing role of the questions during oral arguments, which can inform the justices about their fellow judges’ thoughts and opinions. The Article concludes that these trends in questions, number of words spoken, and interruptions are likely to change as more attention is placed on the importance of oral arguments

Interplay between function and structure in complex networks

We show that abrupt structural transitions can arise in functionally optimal networks, driven by small changes in the level of transport congestion. Our results offer an explanation as to why so many diverse species of network structure arise in Nature (e.g. fungal systems) under essentially the same environmental conditions. Our findings are based on an exactly solvable model system which mimics a variety of biological and social networks. We then extend our analysis by introducing a novel renormalization scheme involving cost motifs, to describe analytically the average shortest path across multiple-ring-and-hub networks. As a consequence, we uncover a 'skin effect' whereby the structure of the inner multi-ring core can cease to play any role in terms of determining the average shortest path across the network.Comment: Expanded version of physics/0508228 with additional new result

Knowledge, Attitudes, and Demographic Factors Influencing Cervical Cancer Screening Behavior of Zimbabwean Women

Aims: The aims of this study were (1) to estimate what proportion of rural females had received cervical screening, (2) to assess knowledge, beliefs, attitudes, and demographics that influence cervical screening, and (3) to predict cervical screening accessibility based on demographic factors, knowledge, beliefs, and attitudes that influence cervical screening. Methods: The study sample consisted of randomly selected, sexually active, rural females between 12 and 84 years of age. Five hundred fourteen females responded to an individually administered questionnaire. Results: Of the 514 participants, 91% had never had cervical screening and 81% had no previous knowledge of cervical screening tests; 80% of the group expressed positive beliefs about cervical screening tests after an educational intervention. Females who were financially independent were 6.61% more likely to access cervical screening compared with those who were dependent on their husbands. Females in mining villages were 4.47% more likely to access cervical screening than those in traditional rural reserve villages. Females in resettlement villages were 20% less likely to access cervical screening than those in traditional rural reserve villages. Conclusions: Accessibility of screening services could be improved through planning and implementation of screening programs involving community leaders and culturally appropriate messages. The government should incorporate the human papillomavirus (HPV) vaccine in its immunization program for adolescents, and health education should be intensified to encourage women and their partners to comply with diagnostic and treatment regimens.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90451/1/jwh-2E2010-2E2062.pd