P-I-N diode switch

Solid state switches use the same voltage and power supply as the RF amplifier. This simplifies circuit design and reduces input power requirements

Climate Change in the High Andes:implications and adaptation strategies for small-scale farmers

Abstract: Global climate change represents a major threat to sustainable farming in the Andes. Farmers have used local ecological knowledge and intricate production systems to cope, adapt and reorganize to meet climate uncertainty and risk, which have always been a fact of life. Those traditional systems are generally highly resilient, but the predicted effects, rates and variability of climate change may push them beyond their range of adaptability. This article examines the extent of actual and potential impacts of climate variability and change on small-scale farmers in the highland Andes of Bolivia, Ecuador and Peru. It describes how climate change impacts agriculture through deglaciation, changes in hydrology, soil and pest and disease populations. The article highlights some promising adaptive strategies currently in use by or possible for producers, rural communities and local institutions to mitigate climate change effects while preserving the livelihoods and environmental and social sustainability of the regio

Inflammatory fibroid polyp of the ileum presenting with small bowel obstruction in an adult patient: a case report

<p>Abstract</p> <p>Introduction</p> <p>Inflammatory fibroid polyps are rare benign tumors of the gastrointestinal tract with the gastric antrum being the most common site, followed by the ileum. Histogenesis is still unknown and controversial. Inflammatory fibroid polyps are one of the rare benign conditions leading to intestinal obstruction in adults.</p> <p>Case presentation</p> <p>A 54-year-old Caucasian man presented with acute abdomen pain and a two month history of intermittent cramping and lower abdominal pain. Computed tomography imaging demonstrated a partial intestinal obstruction in the location of the terminal ileum. An ileo-ileal intussusception due to a mass lesion 15 cm proximal to the caecum was found on exploratory laparotomy. Intussusception was spontaneously reduced during exploration and a wedge resection was performed to the affected bowel segment. Histopathologic examination showed the mass to be an inflammatory fibroid polyp.</p> <p>Conclusion</p> <p>Although inflammatory fibroid polyps are rare and benign, in the case of intestinal obstruction the only solution is a surgical approach.</p

Facilitative effects of learner-directed codeswitching : Evidence from Chinese learners of English

This study examines the interaction between learner-oriented codeswitching (CS) practices and the degree to which intermediate Chinese L2 learners of English engage in classroom interaction. The guiding questions are whether the teacher's CS use facilitates classroom interaction at moderate L2 proficiency, and if so, at which specific stages of the lesson, and to what extent. A systematic comparison of two classroom types was carried out in the same Chinese secondary school, with English-only instruction versus with English–Chinese CS. A combination of quantitative and qualitative analyses was based on class observations (two classes per type) and subsequent teacher interviews. CS behaviour was analysed in relation to the particular teaching focus of the task at hand. Interviews included a stimulated recall technique using selected CS extracts to enrich insights from the teachers' perspective. The results showed a higher student response frequency as well as a longer mean utterance length in CS classes. Overall, codeswitches were systematically distributed across lesson stages and were closely related to changes in the teaching focus. These findings call for an optimal use of CS in instructed environments so as to maximise its benefits via a sensitive adjustment to specific pedagogic aims

Primary tubercular caecal perforation: a rare clinical entity

<p>Abstract</p> <p>Background</p> <p>Intestinal tuberculosis is a common problem in endemic areas, causing considerable morbidity and mortality. An isolated primary caecal perforation of tubercular origin is exceptionally uncommon.</p> <p>Case presentation</p> <p>We report the case of a 39 year old male who presented with features of perforation peritonitis, which on laparotomy revealed a caecal perforation with a dusky appendix. A standard right hemicolectomy with ileostomy and peritoneal toileting was done. Histopathology revealed multiple transmural caseating granulomas with Langerhans-type giant cells and acid-fast bacilli, consistent with tuberculosis, present only in the caecum.</p> <p>Conclusions</p> <p>We report this extremely rare presentation of primary caecal tuberculosis to sensitize the medical fraternity to its rare occurrence, which will be of paramount importance owing to the increasing incidence of tuberculosis all over the world, especially among the developing countries.</p

The T2K ND280 Off-Axis Pi-Zero Detector

The Pi-Zero detector (P{\O}D) is one of the subdetectors that makes up the off-axis near detector for the Tokai-to-Kamioka (T2K) long baseline neutrino experiment. The primary goal for the P{\O}D is to measure the relevant cross sections for neutrino interactions that generate pi-zero's, especially the cross section for neutral current pi-zero interactions, which are one of the dominant sources of background to the electron neutrino appearance signal in T2K. The P{\O}D is composed of layers of plastic scintillator alternating with water bags and brass sheets or lead sheets and is one of the first detectors to use Multi-Pixel Photon Counters (MPPCs) on a large scale.Comment: 17 pages, submitted to NIM