Effect of antenna element properties and array orientation on performance of MIMO systems

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Evaluating the Introduce a Girl to Engineering Day Program

It is well-documented that women in the United States are underrepresented in STEM fields and engineering in particular. This results in the underutilization of the available range of human resources and diverse problem-solving capacity in addressing the types of problems engineers are trained to solve. The lack of female representation in STEM fields may be associated with gender stereotypes and cultural practices that steer women away from engineering, a process that begins in childhood. This study examined the impact of one type of outreach, a 1-day opportunity for young girls in grades 1 through 5 to learn about and get hands-on experience with engineering. As part of this program, gender stereotypes as they relate to STEM fields were also discussed. We were interested in children’s interest in and previous experiences with engineering as well as their and their parent’s general beliefs about the child’s abilities in STEM areas. We collected surveys from parents and children prior to the program and from children immediately and 6 months after the program. Results showed that regardless of child age, participating in the program contributed to a significant increase in children’s self-reported engagement in engineering activities and in knowledge and interest in engineering. However, when followed up 6 months later, children’s self-reports in these areas returned to nearly pretest levels. The findings suggest the need for booster engineering experiences to maintain the gains achieved through participating in the Introduce a Girl to Engineering Day program

Generalised left ventricular dysfunction after traumatic right coronary artery - right atrial fistula

A patient with traumatic right coronary artery to right atrial fistula, which was repaired by direct closure and aortocoronary saphenous vein bypass grafting, is described. Cardiac catheterisation and selective cine angiocardiography were performed pre- and postoperatively, and left ventricular (LV) function was studied in detail by invasive and non-invasive techniques. There was regional (diaphragmatic) LV asynergy but also generalised impairment of myocardial function, and these abnormalities persisted after operation.S. Afr. Med. J., 48, 1829 (1974)

The effectiveness of integrating educational robotic activities into higher education Computer Science curricula: a case study in a developing country

In this paper, we present a case study to investigate the effects of educational robotics on a formal undergraduate Computer Science education in a developing country. The key contributions of this paper include a longitudinal study design, spanning the whole duration of one taught course, and its focus on continually assessing the effectiveness and the impact of robotic-based exercises. The study assessed the students' motivation, engagement and level of understanding in learning general computer programming. The survey results indicate that there are benefits which can be gained from such activities and educational robotics is a promising tool in developing engaging study curricula. We hope that our experience from this study together with the free materials and data available for download will be beneficial to other practitioners working with educational robotics in different parts of the world

Cirsium species show disparity in patterns of genetic variation at their range-edge, despite similar patterns of reproduction and isolation

Genetic variation was assessed across the UK geographical range of Cirsium acaule and Cirsium heterophyllum. A decline in genetic diversity and increase in population divergence approaching the range edge of these species was predicted based on parallel declines in population density and seed production reported seperately. Patterns were compared with UK populations of the widespread Cirsium arvense.Populations were sampled along a latitudinal transect in the UK and genetic variation assessed using microsatellite markers. Cirsium acaule shows strong isolation by distance, a significant decline in diversity and an increase in divergence among range-edge populations. Geographical structure is also evident in C. arvense, whereas no such patterns are seen in C.heterophyllum. There is a major disparity between patterns of genetic variation in C. acaule and C. heterophyllum despite very similar patterns in seed production and population isolation in these species. This suggests it may be misleading to make assumptions about the geographical structure of genetic variation within species based solely on the present-day reproduction and distribution of populations

Family presence during resuscitation: Validation of the risk–benefit and self-confidence scales for student nurses

© 2016, © The Author(s) 2016. Background. There is increasing debate about the advantages and disadvantages of family-witnessed resuscitation. Research about the views of healthcare providers depends upon reliable tools to measure their perceptions. Two tools have been developed for use with nurses (26-item cost-benefit tool, 17-item self-confidence tool). Objectives. Firstly, to validate these tools for use with student nurses in the UK. Secondly, to report on the perceived risks and benefits reported by student nurses, and their self-confidence in dealing with this situation. Methods. A sample of 79 student nurses were invited to complete the tools. Item-total correlations and Cronbach’s α were used to determine internal consistency. Factor analysis was computed to assess construct validity. The correlation between the two scales was explored. Results. 69 students completed a questionnaire. Very few had experience of family-witnessed resuscitation. Mean total scores were 3.16 (standard deviation 0.37; range 2.04–4.12) on the risk-benefit scale and 3.14 (standard deviation 0.66; range 1.94–4.82) on the self-confidence scale. Four of the original items were removed from the risk-benefit scale (Cronbach's α 0.86; 95% confidence interval ≥0.82). None were removed from the self-confidence scale (Cronbach's α 0.93; 95% confidence interval ≥0.91). There was a significant correlation between the two scales (r = 0.37, p = 0.002). Conclusions. There is growing evidence that these tools are valid and reliable for measuring student nurses’ perceptions about family-witnessed resuscitation

Effects of gestational age at birth on cognitive performance : a function of cognitive workload demands

Objective: Cognitive deficits have been inconsistently described for late or moderately preterm children but are consistently found in very preterm children. This study investigates the association between cognitive workload demands of tasks and cognitive performance in relation to gestational age at birth. Methods: Data were collected as part of a prospective geographically defined whole-population study of neonatal at-risk children in Southern Bavaria. At 8;5 years, n = 1326 children (gestation range: 23–41 weeks) were assessed with the K-ABC and a Mathematics Test. Results: Cognitive scores of preterm children decreased as cognitive workload demands of tasks increased. The relationship between gestation and task workload was curvilinear and more pronounced the higher the cognitive workload: GA2 (quadratic term) on low cognitive workload: R2 = .02, p<0.001; moderate cognitive workload: R2 = .09, p<0.001; and high cognitive workload tasks: R2 = .14, p<0.001. Specifically, disproportionally lower scores were found for very (<32 weeks gestation) and moderately (32–33 weeks gestation) preterm children the higher the cognitive workload of the tasks. Early biological factors such as gestation and neonatal complications explained more of the variance in high (12.5%) compared with moderate (8.1%) and low cognitive workload tasks (1.7%). Conclusions: The cognitive workload model may help to explain variations of findings on the relationship of gestational age with cognitive performance in the literature. The findings have implications for routine cognitive follow-up, educational intervention, and basic research into neuro-plasticity and brain reorganization after preterm birth

Seasonal distribution of anti-malarial drug resistance alleles on the island of Sumba, Indonesia

Background: Drug resistant malaria poses an increasing public health problem in Indonesia, especially eastern Indonesia, where malaria is highly endemic. Widespread chloroquine (CQ) resistance and increasing sulphadoxine-pyrimethamine (SP) resistance prompted Indonesia to adopt artemisinin-based combination therapy (ACT) as first-line therapy in 2004. To help develop a suitable malaria control programme in the district of West Sumba, the seasonal distribution of alleles known to be\ud associated with resistance to CQ and SP among\ud Plasmodium falciparum isolates from the region was investigated.\ud Methods: Plasmodium falciparum isolates were collected during malariometric surveys in the wet and dry seasons in 2007 using two-stage cluster sampling. Analysis of pfcrt, pfmdr, pfmdr1 gene copy number, dhfr, and dhps genes were done using protocols described previously.\ud Results and Discussion: The 76T allele of the pfcrt gene is nearing fixation in this population. Pfmdr1 mutant alleles occurred in 72.8% and 53.3%, predominantly as 1042D and 86Y alleles that are mutuallyexclusive. The prevalence of amplified\ud pfmdr1 was found 41.9% and 42.8% of isolates in the wet and dryseasons, respectively. The frequency of dhfr mutant alleles was much lower, either as a single 108N mutation or paired with 59R. The 437G allele was the only mutant dhps allele detected and it was only found during dry season.\ud Conclusion: The findings demonstrate a slighly higher distribution of drug-resistant alleles during the wet season and support the policy of replacing CQ with ACT in this area, but suggest that SP might still be effective either alone or in combination with other anti-malarial