Low-cost quasi-parabolic antenna

Antenna design employs flat petal-shaped aluminum sheets and novel rim configuration. New antenna is inexpensive and has only slightly degraded performance. Design advantages are low-cost tooling and fabrication, convenient size and shape for transport and assembly, and simple assembly procedure

Mannitol Induced Renal Alterations in Rabbits

Mannitol, an alcohol of six carbon sugar-mannose, has a molecular weight of 182.17. It has the inability to enter the tricarboxylic acid cycle which makes mannitol a physiological stable compound. This chemical structure, physical and physiological properties of mannitol are listed in figure 1 Barry, (1963). The clinical use of mannitol as a therapeutic agent has been validated many times in the literature. The utilization of mannitol as a prophylactic measure in prevention of acute renal failure following surgery or trauma has been reported by many authorities. Before recently many surgeons have selected the utilization of mannitol rather than urea as a dehydrating fluid during neurosurgical operations Ohrt, (1967). There is limited and conflicting data describing mannitol\u27s role in osmotic nephrosis of renal tissue. Available research employing experimental animals demonstrating the reversibility of these renal lesions in conjunction with mannitol infusion is very meager. The purpose of this study was to investigate physiological alterations and histological comparisons of mannitol in relation to proximal renal tubules employing virgin doe rabbits. Microscopic analysis was employed to determine reversibility of the histological changes altering tubule lumen size and distance of the nucleus from the basement membrane in respect to different dosage levels and various post-infusion sacrifice times

Developing a \u27Little Ice Age\u27 glacial chronology in the southern Peruvian Andes using lichenometry and cosmogenic beryllium-10 surface exposure dating

The timing and causes of tropical climate changes during the Holocene are important and unresolved issues in paleoclimatology. Glacier chronologies are crucial for discerning the role of the tropics in global climate change, but past glacier activity in this region remains poorly documented. In this study, mapping has identified two prominent glacier advances in three valleys in the Cordillera Vilcabamba (13°20\u27S). 10Be dating reveals that the most recent glacier culminations occurred during the late AD 1700\u27s to early 1800\u27s, which corresponds to the late \u27Little Ice Age\u27 period (LIA; AD 1350--1860). Lichenometric dating suggests near-coeval LIA moraine stabilization in all mapped valleys. The late LIA culmination in the Cordillera Vilcabamba is broadly correlative with glacier chronologies in Europe, North America, and northern Patagonia. However, the timing of events in southern Peru differs from culminations in Alaska and southern Patagonia and from patterns of glaciation in New Zealand. Reconstructed equilibrium line altitudes (ELAs) of glaciers in the Vilcabamba reveal an ELA rise of ∼165--200 m since the LIA, suggesting that temperatures ∼1.1--1.3°C cooler could have sustained glaciers at their LIA position. The difference between ELAs of early Holocene and LIA glaciers is small relative to the ELA rise since the LIA, which highlights the magnitude of the LIA climate oscillation in the tropics. The favored climate hypothesis responsible for sustaining more advanced Vilcabamba glaciers includes a southward displacement of the Intertropical Convergence Zone during the LIA which may have enhanced moisture delivery. The new glacier chronologies developed here augment other high-resolution Holocene tropical records, thereby allowing a fuller understanding of inter-hemispheric climate processes and linkages

Influences on pupils' self-perceptions in primary school: enjoyment of school,anxiety and isolation, and self-image in year 5

This report presents the results of analyses of pupils’ self-perceptions in primary school. It is part of the longitudinal Effective Pre-school and Primary Education 3-11 (EPPE 3-11) research project funded by the Department for Children, Schools and Families (DCSF). The focus of this report is pupils’ self-perceptions in Year 5 (age 10) in four key areas: ‘Enjoyment of school’; ‘Academic self-image’; ‘Behavioural self-image’ and ‘Anxiety and Isolation’. Reports on pupils’ cognitive and social/behavioural development at this age have been published separately (Sammons et al., 2007a; 2007b). The original EPPE sample was recruited to the study at age 3 years plus and monitored to the end of Key Stage 1 (Year 2) in primary school. An additional ‘home’ sample of children (who had not attended a pre-school setting) was recruited when the pre-school sample started primary school. The EPPE 3-11 extension is following up the sample to the end of primary school (age 11 years plus). In addition to exploring pre-school influences, EPPE 3-11 research identifies the influence of primary school on a range of pupils’ educational outcomes, as well as investigating any continuing pre-school effects. EPPE 3-11 involves the collection and analysis of a range of data about pupils’ development, child, family and home learning environment (HLE) characteristics and the characteristics of the schools attended. Additional value added measures of primary school academic effectiveness have been derived from independent statistical analyses of National data sets conducted for all primary schools in England (Melhuish et al., 2006) as part of the study. These have been incorporated into the EPPE 3-11 child database to provide indicators of the academic effectiveness of primary schools attended which complement the measures on pre-school settings. Thus, it is possible to explore both preschool and primary school influences on pupils’ outcomes in Year 5. Questionnaires were administered to children asking their views about school and classroom life. These provided measures of pupils’ self-perceptions in Year 2 and again in Year 5 in terms of ‘Enjoyment of school’, ‘Anxiety and Isolation’ and ‘Academic selfimage’ and ‘Behavioural self-image’. A range of statistical methods have been used to investigate results for 2520 pupils for whom at least one self-perception outcome measure was collected in Year 5

Attracting Diverse Students to a Magnet School: Risking Aspirations or Swallowing One’s Beliefs

This case study focuses on the ethics of advocating for a social justice perspective versus jeopardizing one’s career aspirations. There are numerous subplots to this case involving the start-up of a new magnet school, including its leaders’ concerns for meeting accountability measures and representing racially diverse, limited English proficient, and economically disadvantaged students. Through this case, we illustrate the conflicting choices school leaders may face when trying to balance their own career aspirations with their advocacy of social justice issues for underrepresented groups of students. By using Starratt’s ethical framework along with Strike, Haller, and Soltis’s and Shapiro and Stefkovich’s work on ethical dilemmas, this case highlights the importance of having an ethical framework to base administrative decision making that supports social justice actions for all students

Exploring pupils' views of primary school in Year 5

A range of information about pupils’ self-perceptions and views of their primary school were collected as part of the Effective Provision of Pre-school and Primary Education (EPPE 3-11) Project. The EPPE 3-11 study is funded by the Department for Children, Schools and Families (DCSF) and has followed children’s development from pre-school through to the end of primary school and explored evidence of educational influences in pre-school and primary school, as well as the impact of child, family and home learning environment (HLE) characteristics as predictors of pupils’ outcomes (attainment, social/behavioural development and self-perceptions). In Year 5 the ‘All About Me and My School’ questionnaire included information about pupils’ views of their primary school. A range of statistical methods has been used to investigate results for 2528 pupils for whom at least one pupils’ views of primary school outcome measure was collected in Year 5

Effective Pre-school, Primary and Secondary Education 3-14 Project (EPPSE 3-14): influences on students’ dispositions in Key Stage 3: exploring enjoyment of school, popularity, anxiety, citizenship values and academic self-concept in Year 9

The Effective Pre-school, Primary and Secondary Education Project (EPPSE) has investigated the academic and social-behavioural development of approximately 3,000 children from the age of 3+ years since 1997. This Report and Research Brief reports on students’ dispositions when they were age 14 (Year 9) in six main areas: ‘enjoyment of school’, ‘academic self concept’ (English and maths), ‘popularity’, ‘citizenship values’ and ‘anxiety’. It examines how these dispositions have changed during Key Stage 3 (KS3) and the relationships between dispositions and a range of individual student, family, home, pre-, primary and secondary school measures. It shows how school experiences help to shape dispositions, and also explores the relationships between dispositions to school and students’ academic and social-behavioural outcomes. The findings highlight the importance of the ‘student voice’ and provides an insight into the experiences of teenagers in the first decade of the 21st Century