Composite engines for application to a single-stage-to-orbit vehicle

Seven composite engines were designed for application to a reusable single-stage-to-orbit vehicle. The engine designs were variations of the supercharged ejector ramjet engine. The resulting performance, weight, and drawings of each engine form a data base for establishing a potential of this class of composite engine to various missions, including the single-stage-to-orbit application. The impact of advanced technology in the design of the critical fan turbine was established

The Wiki as a Virtual Space for Qualitative Data Collection

The authors make a case for using wiki technology in qualitative research. A wiki is an online database that allows users to create, edit, and/or reflect on the content of a web page. Thus, wiki technology can support qualitative research that attempts to understand the shared thinking of participants. To illustrate the use of the wiki for this purpose, we describe how we used wiki technology in one phase of a recent Delphi study

Consistency and Change in Participatory Action Research: Reflections on a Focus Group Study about How Farmers Learn

The purpose of this paper is to reflect on our efforts to balance consistency in our multi-year participatory action research study with the need to adapt our research protocol to what we are learning along the way. While both are important, we share several examples of how our flexibility and openness to adapt our protocol to our research findings has lead to methodological refinements and serendipitous learnings. We discuss implications for both agricultural education and research

Using Participatory Focus Groups Of Graduate Students To Improve Academic Departments: A Case Example

The authors report on a participatory focus group evaluation of an academic department. The 20 participants, and the majority of the evaluators, were graduate students in that department. The authors report on their methods, their reflections, ethical issues they encountered and what they did about them, and how they used the results

Consistency and Change in Participatory Action Research: Reflections on a Focus Group Study about How Farmers Learn

The purpose of this paper is to reflect on our efforts to balance consistency in our multi-year participatory action research study with the need to adapt our research protocol to what we are learning along the way. While both are important, we share several examples of how our flexibility and openness to adapt our protocol to our research findings has lead to methodological refinements and serendipitous learnings. We discuss implications for both agricultural education and research

B-virus from pet macaque monkeys: an emerging threat in the United States?

Of primary concern when evaluating macaque bites are bacterial and B-virus infections. B-virus infection is highly prevalent (80% to 90%) in adult macaques and may cause a potentially fatal meningoencephalitis in humans. We examined seven nonoccupational exposure incidents involving 24 persons and eight macaques. Six macaques were tested for herpes B; four (67%) were seropositive. A common observation was that children were more than three times as likely to be bitten than adults. The virus must be assumed to be a potential health hazard in macaque bite wounds; this risk makes macaques unsuitable as pets

Pregnancies in older women living with HIV in the UK and Ireland.

OBJECTIVES: The aim of the study was to compare maternal characteristics and pregnancy outcomes in women aged < 40 years and ≥ 40 years in a large unselected population of HIV-positive women delivering in the UK and Ireland between 2000 and 2014. METHODS: Comprehensive population-based surveillance data on all HIV-positive pregnant women and their children seen for care in the UK and Ireland are collected through the National Study of HIV in Pregnancy and Childhood. All singleton and multiple pregnancies reported by the end of June 2015 resulting in live birth or stillbirth to women diagnosed with HIV infection before delivery and delivering in 2000-2014 were included. Logistic regression models were fitted in analyses examining the association between older maternal age and specific outcomes (preterm delivery and stillbirth). RESULTS: Among 15 501 pregnancies in HIV-positive women, the proportion in older women (≥ 40 years) increased from 2.1% (73 of 3419) in 2000-2004 to 8.9% (510 of 5748) in 2010-2014 (P < 0.001). Compared with pregnancies in younger women, those in older women were more likely to result in multiple birth (3.0 vs. 1.9% in younger women; P = 0.03), stillbirth (adjusted odds ratio 2.39; P = 0.004) or an infant with a chromosomal abnormality (1.6 vs. 0.2%, respectively; P < 0.001). However, there was no increased risk of preterm delivery, low birth weight or mother-to-child HIV transmission among older mothers. CONCLUSIONS: There has been a significant increase over time in the proportion of deliveries to women living with HIV aged ≥ 40 years, which has implications for pregnancy management, given their increased risk of multiple births, stillbirth and chromosomal anomalies, as also apparent in the general population

Distinguishing Social from Nonsocial Navigation in Moving Animal Groups

Many animals, such as migrating shoals of fish, navigate in groups. Knowing the mechanisms involved in animal navigation is important when it comes to explaining navigation accuracy, dispersal patterns, population and evolutionary dynamics, and consequently, the design of conservation strategies. When navigating toward a common target, animals could interact socially by sharing available information directly or indirectly, or each individual could navigate by itself and aggregations may not disperse because all animals are moving toward the same target. Here we present an analysis technique that uses individual movement trajectories to determine the extent to which individuals in navigating groups interact socially, given knowledge of their target. The basic idea of our approach is that the movement directions of individuals arise from a combination of responses to the environment and to other individuals. We estimate the relative importance of these responses, distinguishing between social and nonsocial interactions. We develop and test our method, using simulated groups, and we demonstrate its applicability to empirical data in a case study on groups of guppies moving toward shelter in a tank. Our approach is generic and can be extended to different scenarios of animal group movement. © 2012 by The University of Chicago