536 results on '"Howe, MA"'
Search Results
202. Comprehensive study of the structure of aluminum trihalides from electron diffraction and computation.
- Author
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Varga, Zoltán, Kolonits, Mária, and Hargittai, Magdolna
- Subjects
GEOMETRY ,ELECTRON diffraction ,MONOMERS ,OLIGOMERS ,CRYSTALS ,ALUMINUM - Abstract
The molecular geometries of the complete series of aluminum trihalides, AlX (X = F, Cl, Br, and I), are discussed based on new gas-phase electron diffraction (GED) experiments (AlCl and AlCl) and on the reanalysis of our previous GED data (for the rest of the series) with an improved and analogous treatment of the temperature effect on the average bond lengths. This is the first time that all structure analyses are based on GED experiments of homogeneous vapors; either as pure monomers or dimers. The structures of other small oligomers as well as those of the crystals of aluminum trihalides are also discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
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203. Integrated Marsh Management (IMM): a new perspective on mosquito control and best management practices for salt marsh restoration.
- Author
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Rochlin, Ilia, James-Pirri, Mary-Jane, Adamowicz, Susan, Wolfe, Roger, Capotosto, Paul, Dempsey, Mary, Iwanejko, Thomas, and Ninivaggi, Dominick
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MOSQUITO control ,SALT marsh restoration ,SALT marsh mosquito ,NEKTON ,SPARTINA ,PHRAGMITES australis - Abstract
Salt marsh management often embraces diverse goals, ranging from the restoration of degraded marshes through re-introduction of tidal flow to the control of salt marsh mosquito production by altering marsh surface topography through Open Water Marsh Management (OMWM). However, rarely have these goals been incorporated in one project. Here we present the concept of Integrated Marsh Management (IMM), which combines the best management practices of salt marsh restoration and OMWM. Although IMM offers a comprehensive approach to ecological restoration and mosquito control, research evaluating this concept's practical implementations has been inadequate. A long-term IMM project at Wertheim National Wildlife Refuge located in a highly urbanized watershed on Long Island, New York, USA was designed to fill this knowledge gap. A combination of restoration and OMWM techniques was employed at two treatment marshes, the results monitored before and after alterations, and compared to two adjacent control marshes. The treatment marshes experienced decreased mosquito production, reduced cover of the invasive common reed ( Phragmites australis), expansion of native marsh vegetation, increased killifish and estuarine nekton species abundance, as well as increased avian species diversity and waterbird abundance. This demonstration project validated the IMM conceptual approach and may serve as a case study for similar IMM projects in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
204. A morphological and molecular assessment of the genus Sinotubimorpha (Halymeniaceae, Rhodophyta).
- Author
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SHENG, Ying-Wen, ZHANG, Wen, ZHAO, Dan, and WANG, Hong-Wei
- Subjects
RED algae ,ALGAE ,MOLECULAR phylogeny ,TAXONOMY ,CRYPTONEMIALES - Abstract
A critical reassessment of the morphological features of two closely related red algal genera, Grateloupia C. Agardh and Sinotubimorpha W. X. Li & Z. F. Ding (Halymeniaceae), pointed out that members of the two genera had most morphological characteristics in common, including the Grateloupia type auxiliary cell ampullae. Sinotubimorpha hitherto was distinguished from Grateloupia by: (i) the hollow axis; (ii) the presence of secondary filaments in ampullae; (iii) 1- to 3-celled carpogonial branch; and (iv) the occasional production of 1- to 4-celled flanking filaments on carpogonium. However, when these features were re-examined among 37 Chinese species of genera described in Flora Algarum Marinarum Sinicarum and one newly reported species, Grateloupia orientalis, we found that it was difficult to draw a clear-cut distinction between the two genera based only on morphological differences. In rbcL sequence analysis, all the species of Sinotubimorpha with G. catenata formed a single monophyletic subclade within the large Grateloupia clade of the Halymeniaceae. It is therefore suggested that all the Chinese species of Sinotubimorpha, S. catenata, S. guangdongensis, S. qingdaoensis, S. claviformis, and S. ramosissima should be synonymous with G. catenata, and that Sinotubimorpha should be included in synonymy under Grateloupia. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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205. Potential Impact of Climate Change Scenarios on Whooping Crane Life History.
- Author
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Chavez-Ramirez, Felipe and Wehtje, Walter
- Abstract
Whooping crane ( Grus americana), a rare and critically endangered species, are wetland dependent throughout their life cycle. The whooping crane's small population size, limited distribution, and wetland habitat requirements make them vulnerable to potential climate changes. Climate change predictions suggest overall temperature increases and significant changes in precipitation regimes throughout North America. At the individual level, temperature changes should have neutral to positive effects on thermoregulation and overall energy expenditure throughout the whooping crane's range. In the breeding grounds, earlier snow melt and increasing temperatures should improve food resources. However, increased precipitation and more extreme rainfall events could impact chick survival if rainfall occurs during hatching. Increased precipitation may also alter fire regimes leading to increased woody plant abundance thus reducing nesting habitat quality. During winter, higher temperatures will lead to a northward shifting of the freeze line, which will decrease habitat quality via invasion of black mangrove. Large portions of current winter habitat may be lost if predicted sea level changes occur. Stopover wetland availability during migration may decrease due to drier conditions in the Great Plains. Current and future conservation actions should be planned in light of not only current needs but also considering future expectations. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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206. Secondary spread of invasive species: historic patterns and underlying mechanisms of the continuing invasion of the European rockweed Fucus serratus in eastern North America.
- Author
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Johnson, Ladd, Brawley, Susan, and Adey, Walter
- Abstract
Post-establishment spread of invasive species is a major determinant of their impact, but the spatial pattern and temporal rhythm of secondary spread are often poorly known or understood. Here we examine the spread of the European rockweed Fucus serratus over 1,500 km of shoreline after its initial discovery in Pictou, Nova Scotia (Canada) in 1868. Building upon earlier periodic surveys, we document the current distribution of this invader and provide a historic analysis of the invasion, including the integration of the recently-detected multiple introductions from Europe. The initial spread was rapid in the southern Gulf of St. Lawrence (6.0 km year), likely due to both natural spread in a favorable environment and the extensive regional shipping traffic at the time which linked Pictou to several key ports in eastern Canada and northeast USA. Later spread, especially along the Atlantic coast of Nova Scotia, was slower (recently 0.9 km year), but included several major jumps (~50-500 km), undoubtedly due to human-mediated transport. Although the spatial extent of the invasion has increased over the past 140 years, it has experienced several remarkable events: apparent local extinctions of northern satellite populations, a major retraction (100-150 km) along the northwestern limits of its continuous range, and stalled invasions at several points and times during its southward progression. Distributional data suggest that this invader is excluding congeners in shallow zones and possibly kelp species in deeper zones. Genetic data from one contact zone showed hybridization with native F. distichus but no evidence for introgression in migrating F. serratus. Hybridization and several other reproductive traits likely contribute to the competitive dominance of the invader in this environment. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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207. Ten into one can go: gaining educational capacity through large group teaching in general practice.
- Author
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Howe, Amanda, Hand, Christopher, and Young, Richard
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FAMILY medicine ,PHYSICIANS ,GROUP process ,TEACHING methods - Abstract
The article offers information regarding the undergraduate teaching development in general practice in the University of East Anglia. It mentions that written communication and systematic face-to-face were use to address issue in terms of fitting the innovations with the current practice. It states that medical students found that large group teaching in general practice is highly satisfactory and feasible.
- Published
- 2011
208. Population cycles are highly correlated over long time series and large spatial scales in two unrelated species: greater sage-grouse and cottontail rabbits.
- Author
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Fedy, Bradley C. and Doherty, Kevin E.
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ANIMAL species ,COTTONTAILS ,SAGE grouse ,ANIMAL populations ,PREDATION ,PARASITISM - Abstract
nimal species across multiple taxa demonstrate multi-annual population cycles, which have long been of interest to ecologists. Correlated population cycles between species that do not share a predator-prey relationship are particularly intriguing and challenging to explain. We investigated annual population trends of greater sage-grouse ( Centrocercus urophasianus) and cottontail rabbits ( Sylvilagus sp.) across Wyoming to explore the possibility of correlations between unrelated species, over multiple cycles, very large spatial areas, and relatively southern latitudes in terms of cycling species. We analyzed sage-grouse lek counts and annual hunter harvest indices from 1982 to 2007. We show that greater sage-grouse, currently listed as warranted but precluded under the US Endangered Species Act, and cottontails have highly correlated cycles ( r = 0.77). We explore possible mechanistic hypotheses to explain the synchronous population cycles. Our research highlights the importance of control populations in both adaptive management and impact studies. Furthermore, we demonstrate the functional value of these indices (lek counts and hunter harvest) for tracking broad-scale fluctuations in the species. This level of highly correlated long-term cycling has not previously been documented between two non-related species, over a long time-series, very large spatial scale, and within more southern latitudes. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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209. Quantitative Risk Assessment Modeling for Nonhomogeneous Urban Road Tunnels.
- Author
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Meng, Qiang, Qu, Xiaobo, Wang, Xinchang, Yuanita, Vivi, and Wong, Siew Chee
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RISK assessment ,TUNNELS ,COST effectiveness ,METROPOLITAN areas ,CITIES & towns - Abstract
Urban road tunnels provide an increasingly cost-effective engineering solution, especially in compact cities like Singapore. For some urban road tunnels, tunnel characteristics such as tunnel configurations, geometries, provisions of tunnel electrical and mechanical systems, traffic volumes, etc. may vary from one section to another. These urban road tunnels that have characterized nonuniform parameters are referred to as nonhomogeneous urban road tunnels. In this study, a novel quantitative risk assessment (QRA) model is proposed for nonhomogeneous urban road tunnels because the existing QRA models for road tunnels are inapplicable to assess the risks in these road tunnels. This model uses a tunnel segmentation principle whereby a nonhomogeneous urban road tunnel is divided into various homogenous sections. Individual risk for road tunnel sections as well as the integrated risk indices for the entire road tunnel is defined. The article then proceeds to develop a new QRA model for each of the homogeneous sections. Compared to the existing QRA models for road tunnels, this section-based model incorporates one additional top event-toxic gases due to traffic congestion-and employs the Poisson regression method to estimate the vehicle accident frequencies of tunnel sections. This article further illustrates an aggregated QRA model for nonhomogeneous urban tunnels by integrating the section-based QRA models. Finally, a case study in Singapore is carried out. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
210. Genetic diversity of Ectocarpus (Ectocarpales, Phaeophyceae) in Peru and northern Chile, the area of origin of the genome-sequenced strain.
- Author
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Peters, Akira F., Mann, Aaron D., Córdova, César A., Brodie, Juliet, Correa, Juan A., Schroeder, Declan C., and Cock, J. Mark
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BROWN algae ,GENETIC research ,BOTANY ,PLANT genetics - Abstract
∙ The origin of the Ectocarpus strain used for genome sequencing (the 'genome strain') was Peru, where no Ectocarpus had been reported previously. To study the genetic diversity in the region and to increase the number of individuals from this area available for genetic experiments, 119 new Ectocarpus strains were isolated from eight localities along the 3000 km of coastline from central Peru to central Chile. ∙ Internal transcribed spacer 1 (ITS1) genotyping revealed nine different genotypes, five of which were endemic to the area studied and three of which were previously unknown. ∙ Individuals of the same genotype as the genome strain occurred from Peru to northernmost Chile, representing 61% of the samples in this area, from which five more genotypes were isolated. Further south, down to central Chile, most individuals belonged to Ectocarpus siliculosus, Ectocarpus fasciculatus and Ectocarpus crouaniorum. In sexual crosses, the genome strain and the new isolates of the same genotype were fully compatible. ∙ Sequences from four nuclear and cytoplasmic genetic markers (ITS1, ITS2, Rubisco spacer and Cytochrome-c oxidase subunit 3 (cox3)) separated the genome strain from the known species of Ectocarpus. It may in future be recognized as a separate species. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
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211. Evaluating Maclaurin and Sterelny’s conception of biodiversity in cases of frequent, promiscuous lateral gene transfer.
- Author
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Morgan, Gregory
- Subjects
BIODIVERSITY ,GENETIC transformation ,PHYLOGENY ,PHENETICS ,MICROBIOLOGY ,BACTERIA - Abstract
The recent conception of biodiversity proposed by James Maclaurin and Sterelny was developed mostly with macrobiological life in mind. They suggest that we measure biodiversity by dividing life into natural units (typically species) and quantifying the differences among units using phenetic rather than phylogenetic measures of distance. They identify problems in implementing quantitative phylogenetic notions of difference for non-prokaryotic species. I suggest that if we focus on microbiological life forms that engage in frequent, promiscuous lateral gene transfer (LGT), and their associated reticulated phylogenies, we need to rethink the notion of species as the natural unit, and we discover additional problems with phylogenetic notions of distance. These problems suggest that a phenetic approach based on morphospaces has just as much appeal, if not more, for microbes as they do for multi-cellular life. Facts about LGT, however, offer no new insight into the additional challenge of reconciling units and differences into a single measure of biodiversity. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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212. The importance of coastal sand dunes for terrestrial invertebrates in Wales and the UK, with particular reference to aculeate Hymenoptera (bees, wasps & ants).
- Author
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Howe, M., Knight, G., and Clee, C.
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SAND dunes ,COASTAL ecology ,INVERTEBRATES ,BEES ,WASPS ,ANTS - Abstract
Although most UK sand dune systems are now fossilized, with little mobility and reducing amounts of bare sand, they support important populations and assemblages of terrestrial invertebrates. Offering open conditions, warm substrates and a range of habitats and habitat structures, they have become increasingly significant as other coastal habitats have been lost. In Wales, 680 Red Data Book and Nationally Scarce species have been recorded from dunes. 109 species in the UK are restricted to dunes, and in Wales there are an additional 145 species confined to dunes and 208 species strongly associated with dunes. Of these, 172 species are dependent upon bare and sparsely-vegetated sand, in grey dunes and early-successional dune grassland, at some stage of their life cycle, rising to 292 species if those associated with the strandline, foredunes, yellow dunes and pioneer dune slacks are included, equating to 63% of the 462 dune species. Bees and wasps are particularly well represented, with 278 species (68% of the Welsh fauna) recorded on Welsh dunes, including 17 obligates and 44 species with a strong dependence, 52 of which are associated with bare and sparsely-vegetated sand. Key to maintaining invertebrate populations on UK dunes is the provision of bare sand but in Wales, bare sand accounts for only 1.7% of the total sand dune resource. As a more appropriate bare sand threshold is likely to range between 10 and 30%, radical action is required to re-mobilize at least the key sand dune systems. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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213. Have we neglected the societal importance of sand dunes? An ecosystem services perspective.
- Author
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Everard, Mark, Jones, Laurence, and Watts, Bill
- Subjects
SAND dunes ,ECOSYSTEM services ,ECOSYSTEM management ,HABITATS ,SAND dune ecology - Abstract
The article presents a study which assesses whether potential contributions to ecosystem services of sand dunes systems are overlooked. It says that the assessment makes use of the Millennium Ecosystem Assessment ecosystem services classification augmented with habitat and locally-appropriate additions. Results show that even with the noted importance of coastal sand dune systems, many of the ecosystem contributions are being neglected and still are often underappreciated and overlooked.
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- 2010
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214. The Sudbury Neutrino Observatory.
- Author
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Jelley, Nick, McDonald, Arthur B., and Robertson, R. G. Hamish
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SOLAR neutrinos ,RADIOCHEMISTRY ,NUCLEAR reactions ,SCATTERING (Physics) ,NEUTRINO astrophysics ,CHERENKOV counters ,MODELS & modelmaking - Abstract
The solar neutrino problem arose when the first measurements of the flux of neutrinos from the Sun, taken by Raymond Davis, Jr. with a Cl-Ar radiochemical detector, fell substantially below the value predicted theoretically by John Bahcall. Bahcall's prediction came from a detailed model of the nuclear reactions powering the Sun. Resolution of the problem came three decades later with the observation of nonelectron flavors of neutrinos in the solar flux. The use of heavy water in the Suclbuiy Neutrino Observatory (SNO) experiment provided a means to measure both electron and nonelectron components, and the presence of the latter showed that neutrino flavor conversion was taking place-a hallmark of neutrino oscillation and mass. The solar models were vindicated, and the Standard Model of elementary particles and fields had to be revised. Here we present an account of the SNO project, its conclusions to date, and its ongoing analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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215. Complementary use of natural and artificial wetlands by waterbirds wintering in Doñana, south-west Spain.
- Author
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Kloskowski, Janusz, Green, Andy J., Polak, Marcin, Bustamante, Javier, and Krogulec, JarosŁaw
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WETLANDS ,WATER birds ,FISH ponds ,ANATIDAE ,HABITATS - Abstract
The article the use of natural seasonal marshes by 12 common waterbirds in Doñana National Park (DNP) and Veta la Palma fish ponds in south-west Spain. The study shows that changes in the extent of flooded marshes within DNP affects the changes in distribution of each bird taxon. Moreover, the number of ducks at VLP decline when water levels in DNP are stable during winter.
- Published
- 2009
- Full Text
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216. Life table assay of field-caught Mediterranean fruit flies, Ceratitis capitata, reveals age bias.
- Author
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Kouloussis, Nikos A., Papadopoulos, Nikos T., Müller, Hans-Georg, Wang, Jane-Ling, Mao, Meng, Katsoyannos, Byron I., Duyck, Pierre-François, and Carey, James R.
- Subjects
FRUIT flies ,PHYTOPHAGOUS insects ,INSECT sex attractants ,INSECT baits & repellents ,PHEROMONES - Abstract
Though traps are used widely to sample phytophagous insects for research or management purposes, and recently in aging research, possible bias stemming from differential response of individuals of various ages to traps has never been examined. In this paper, we tested the response of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) males and females of four ages (spanning from 1 to 40 days) to McPhail-type traps baited with a synthetic food attractant in field cages and found that the probability of trapping was significantly influenced by age. The type of food on which flies were maintained before testing (sugar or protein) also had a strong effect and interacted with age. In another experiment, we collected wild C. capitata adults of unknown age using 1–3 methods and then reared them in the laboratory until death. The survival schedules of these flies were subsequently used in a life table assay to infer their age at the time of capture. Results showed that on a single sampling date, males captured in traps baited with a food attractant were younger compared with males aspirated from fruiting host trees, or males captured in traps baited with a sex attractant. Likewise, females captured in food-baited traps were younger compared with aspirated females. In addition to providing the first evidence of age-dependent sampling bias for a phytophagous insect species, this paper also provides a novel approach to estimate the differences in the age composition of samples collected with different techniques. These findings are of utmost importance for several categories of insects, medically important groups notwithstanding. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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217. An evaluation of two biochemical methods of age determination in insects (pteridines and lipofuscins) using the ant Polyrhachis sexpinosa Latrielle (Hymenoptera: Formicidae).
- Author
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Robson, Simon K. A. and Crozier, Ross H.
- Subjects
INSECT age ,PTERIDINES ,LIPOFUSCINS ,POLYRHACHIS ,INSECT societies ,ARTHROPOD pests ,CAPTIVE wild animals ,FLUORIMETRY ,HYMENOPTERA behavior - Abstract
Accurate information on the age of wild-caught animals is valuable for a variety of areas, but can be particularly difficult to obtain for small holometabolous insects, whose body size is fixed at the time of pupal eclosion. A variety of chemical groups, such as lipofuscins and pteridines accumulate in body tissues through time and can be used to predict age in a variety of arthropod taxa. Here we use spectrofluorometry to confirm the presence of extractable levels of lipofuscins and pteridines in individual social insects (using the ant Polyrhachis sexpinosa Latrielle, average body size 25 mg, as an example) and evaluate their ability to predict age. Pteridine levels were independent of age but lipofuscin levels increased with age in a predictable manner ( r
2 = 72.8%). Lipofuscin levels therefore represent a new method of age determination for social insects that should be applicable to both individual laboratory and wild-caught animals. [ABSTRACT FROM AUTHOR]- Published
- 2009
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218. Developing a set of quality criteria for community-based medical education in the UK.
- Author
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Cotton, Philip, Sharp, Debbie, Howe, Amanda, Starkey, Caroline, Laue, Barbara, Hibble, Arthur, and Benson, John
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FAMILY medicine ,MEDICAL practice ,STAKEHOLDERS ,FOCUS groups ,TECHNICAL specifications - Abstract
Context General practices educate increasing numbers of learners at various stages. Criteria for educational provision exist, but practices supporting learners at different stages and from different institutions might face different criteria. Methods Criteria for practice-based teaching were developed at a workshop at a national conference. An online Delphi questionnaire invited educationalists to label these criteria as 'essential', 'desirable' or 'unnecessary' for 'occasional', 'intensive' and 'foundation year' teaching. Two rounds of the Delphi were completed. The views about the criteria of a range of stakeholders were explored using focus groups and telephone interviews. Results We generated 76 criteria in five domains; physical environment, learning environment, tutor characteristics, patient involvement and departmental responsibilities. Stakeholders' views differed concerning the merits of criteria and which should take greatest priority. None felt that developing such a list was inappropriate. They proposed no new criteria to add to those identified in the Delphi process Conclusion To the best of our knowledge this is the first nationally derived list of criteria, capable of being used in both undergraduate and postgraduate practice-based medical education. These criteria can provide a benchmark against which to set local criteria. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
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219. Prevalence of emotional and behavioural problems among 6–12 year old children in Egypt.
- Author
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Elhamid, Asmaa Abd, Howe, Amanda, and Reading, Richard
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DISEASE prevalence ,MENTAL health ,CHILD psychology ,SYMPTOMS in children ,BEHAVIOR disorders in children ,CHILDREN'S health ,CHILD psychiatry ,PSYCHIATRIC epidemiology ,PUBLIC health administration ,PUBLIC health laws - Abstract
Epidemiological information about prevalence of child mental health problems is essential to inform policy and public health practice. This information is weak in many developing countries and those in developmental transition. There have been few such studies in Arab countries and none in Egypt. We conducted a population prevalence study of emotional and behavioural disorders among 1186 6–12 year old children in Minia, Egypt. Data was collected from teachers and parents using the Strengths and Difficulties Questionnaire with a 98 and 91% response respectively. Prevalence of abnormal symptom scores is reported for both parents and teachers. Prevalence of probable psychiatric diagnoses was measured using the SDQ multi-informant algorithm. These prevalences have then been compared to published UK data. The prevalence of emotional and behavioural symptoms was high as reported by both parents and teachers (Abnormal total difficulties: teachers 34.7% (95% CI 32.0–37.5), parents 20.6% (18.2–23.2). Abnormal prosocial scores: teachers 24.9% (22.5–27.5), parents 11.8% (9.9–13.9)) but prevalence of probable psychiatric diagnoses was much lower (Any psychiatric diagnosis 8.5% (6.9–10.5); Emotional disorder 2.0% (1.2–3.0); Conduct disorder 6.6% (5.1–8.3); Hyperactivity disorder 0.7% (0.3–1.4)). Comparison with UK data showed higher rates of symptoms but similar rates of probable disorders. Despite public, professional and political underestimation of child mental health problems in Egypt, rates of symptoms are higher than in developed countries, and rates of disorders are comparable. These findings support greater investment in community and primary care prevention and treatment initiatives. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
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220. Structural transitions in interionic force models of liquid AlCl3.
- Author
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Ruberto, R., Pastore, G., and Tosi, M.P.
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FUSED salts ,LIQUIDS ,ATMOSPHERIC pressure ,ATMOSPHERIC temperature ,SOLIDIFICATION ,MONOMERS ,X-ray diffraction - Abstract
We present molecular dynamics simulation of an interionic force model of liquid AlCl3 along a few paths in the temperature-density plane. These paths include (1) an isobar and an isochore starting from the experimental standard freezing point (SFP), and (2) high-temperature isotherms starting from the isochore passing through the SFP. Our calculations show: the dissociation of dimers and higher molecular clusters into monomers with increasing temperature both along the experimental atmospheric pressure isobar and along the SFP isochore; and the pressure-induced molecular-to-ionic (MI) transition accompanied by, or followed by, solidification on increasing density along the two isotherms. The high-pressure solid structure is of the same layer type, with 6-fold coordinated metal ions, met at standard pressure. Crossing of the mean square displacements of the two ionic species provides a clear signal of the MI transition in the liquid. We discuss the consistency of our results with recent X-ray diffraction experiments on AlCl3 under pressure. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
221. From Genes to Ecosystems: The Genetic Basis of Condensed Tannins and Their Role in Nutrient Regulation in a Populus Model System.
- Author
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Schweitzer, Jennifer A., Madritch, Michael D., Bailey, Joseph K., LeRoy, Carri J., Fischer, Dylan G., Rehill, Brian J., Lindroth, Richard L., Hagerman, Ann E., Wooley, Stuart C., Hart, Stephen C., and Whitham, Thomas G.
- Subjects
GENES ,BIOTIC communities ,TANNINS ,POPLARS ,PLANT variation ,TISSUES ,HETEROTROPHIC bacteria ,NUTRITIONAL requirements ,HOLISTIC education - Abstract
Research that connects ecosystem processes to genetic mechanisms has recently gained significant ground, yet actual studies that span the levels of organization from genes to ecosystems are extraordinarily rare. Utilizing foundation species from the genus Populus, in which the role of condensed tannins (CT) has been investigated aboveground, belowground, and in adjacent streams, we examine the diverse mechanisms for the expression of CT and the ecological consequences of CT for forests and streams. The wealth of data from this genus highlights the importance of form and function of CT in large-scale and long-term ecosystem processes and demonstrates the following four patterns: (1) plant-specific concentration of CT varies as much as fourfold among species and individual genotypes; (2) large within-plant variation in CT occurs due to ontogenetic stages (that is, juvenile and mature), tissue types (that is, leaves versus twigs) and phenotypic plasticity in response to the environment; (3) CT have little consistent effect on plant–herbivore interactions, excepting organisms utilizing woody tissues (that is, fungal endophytes and beaver), however; (4) CT in plants consistently slow rates of leaf litter decomposition (aquatic and terrestrial), alter the composition of heterotrophic soil communities (and some aquatic communities) and reduce nutrient availability in terrestrial ecosystems. Taken together, these data suggest that CT may play an underappreciated adaptive role in regulating nutrient dynamics in ecosystems. These results also demonstrate that a holistic perspective from genes-to-ecosystems is a powerful approach for elucidating complex ecological interactions and their evolutionary implications. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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222. Age structure changes and extraordinary lifespan in wild medfly populations.
- Author
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Carey, James R., Papadopoulos, Nikos T., Müller, Hans-Georg, Katsoyannos, Byron I., Kouloussis, Nikos A., Wang, Jane-Ling, Wachter, Kenneth, Wei Yu, and Liedo, Pablo
- Subjects
MEDITERRANEAN fruit-fly ,MIDDLE age ,AGING ,MORTALITY ,INSECTS - Abstract
The main purpose of this study was to test the hypotheses that major changes in age structure occur in wild populations of the Mediterranean fruit fly (medfly) and that a substantial fraction of individuals survive to middle age and beyond (> 3–4 weeks). We thus brought reference life tables and deconvolution models to bear on medfly mortality data gathered from a 3-year study of field-captured individuals that were monitored in the laboratory. The average time-to-death of captured females differed between sampling dates by 23.9, 22.7, and 37.0 days in the 2003, 2004, and 2005 field seasons, respectively. These shifts in average times-to-death provided evidence of changes in population age structure. Estimates indicated that middle-aged medflies (> 30 days) were common in the population. A surprise in the study was the extraordinary longevity observed in field-captured medflies. For example, 19 captured females but no reference females survived in the laboratory for 140 days or more, and 6 captured but no reference males survived in the laboratory for 170 days or more. This paper advances the study of aging in the wild by introducing a new method for estimating age structure in insect populations, demonstrating that major changes in age structure occur in field populations of insects, showing that middle-aged individuals are common in the wild, and revealing the extraordinary lifespans of wild-caught individuals due to their early life experience in the field. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
223. Molecular clusters in gaseous and liquid AlCl3.
- Author
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Akdeniz, Z., Önem, Z. Çiçek, Ruberto, R., Pastore, G., and Tosi, M.P.
- Subjects
MICROCLUSTERS ,ALUMINUM chloride ,GASES ,LIQUIDS ,PROPERTIES of matter - Abstract
Motivated by results on molecular clusters formed from octahedral connectivity in NbF5 and by simulation and neutron diffraction studies of liquid AlCl3 and related materials, we discuss the gaseous n-mers of AlCl3 built from corner-sharing or edge-sharing tetrahedra. We use an interionic force-law model to evaluate the energetics of these clusters and examine their relevance to liquid structure near freezing and at higher temperatures as determined by means of classical molecular-dynamics simulation. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
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224. Taxonomy and inventory of the cytospecies and cytotypes of the Simulium damnosum complex (Diptera: Simuliidae) in relation to onchocerciasis.
- Author
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Post, R. J., Mustapha, M., and Krueger, A.
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SIMULIUM damnosum ,TAXONOMY ,ONCHOCERCIASIS ,ONCHOCERCA volvulus ,FILARIASIS ,CHROMOSOMES ,SKIN diseases - Abstract
Copyright of Tropical Medicine & International Health is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2007
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225. From molecular clusters to liquid structure in AlCl3 and FeCl3.
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Goat, E, Ruberto, R, Pastore, G, Akdeniz, Z, and Tosi, MP
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FUSION (Phase transformation) ,ALUMINUM ,FERRIC chloride ,OPTICAL diffraction ,FOURIER transforms - Abstract
Melting of aluminum and iron trichloride is accompanied by a structural transition from sixfold to fourfold coordination of the trivalent metal ions, and a widely accepted interpretation of the structure of their melts near freezing is that they mainly consist of strongly correlated dimers formed from two edge-sharing tetrahedra. We carry out classical molecular dynamics simulations to examine how a polarizable-ion force law, determined on isolated molecular monomers and dimers in the gaseous phase of these compounds, fares in accounting for the pair structure of their liquid phase and for mean square displacements and diffusion coefficients of the two species in each melt. The model reproduces the main features of the neutron diffraction structure factor, showing peaks due to intermediate range order and to charge and density short-range order, and accounts for the experimental data at a good semi-quantitative level. We find agreement with the neutron and X-ray diffraction data on metal-halogen and Cl-Cl bond lengths in the melt, and demonstrate the high sensitivity of the results for the width of the first-neighbor shell to truncation in obtaining it by Fourier transform of the neutron-weighted structure factor in momentum space. We also report comparisons with a recent first-principles study of the structure of the AlCl3 melt by the Car-Parrinello method. Finally, we demonstrate break-up of dimers into monomers upon raising the liquid temperature in the case of AlCl3. [ABSTRACT FROM AUTHOR]
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- 2007
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226. Characterization of Grateloupia lanceola (Halymeniales, Rhodophyta), an obscure foliose Grateloupia from the Iberian Peninsula, based on morphology, comparative sequence analysis and mycosporine-like amino acid composition.
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Figueroa, Félix L., Korbee, Nathalie, Clerck, Olivier de, Bárbara, Ignacio, and Gall, Erwan A. R.
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RED algae ,MYCOSPORINE-like amino acids ,AMINO acids ,RECOMBINANT DNA ,PLANT morphology - Abstract
Foliose Grateloupia species are among the most commonly reported introduced species of red algae in European waters. Unequivocal identification at species level, however, has proven exceedingly difficult owing to a relatively low number of clear-cut diagnostic characters and considerable morphological plasticity. Because of their morphological similarity many of these species were placed in synonymy by subsequent generations of phycologists. In the present paper we demonstrate that Gratelopia lanceola, a native European species, is distinct from G. turuturu, a western Pacific alga introduced in European waters. These conclusions are based on comparative gene sequences (rbcL and LSU rDNA) as well as morphology and mycosporine-like amino acid (MAA) signatures. Even though support was largely lacking from rbcL and the combined analysis, G. lanceola was clearly separated from G. turuturu as well as other foliose species. These data, together with earlier accounts on genuine G. doryphora and G. schizophylla, indicate that foliose Grateloupia species display a clear geographic structuring, which has only become obscured by the recent introduction of morphologically similar species (pseudo-cryptic species) along Atlantic coasts and in the Mediterranean Sea. Grateloupia lanceola also showed a different MAA composition when compared with G. turuturu, regardless of spatial-temporal influences. The concentrations were about 3 mg g-1 DW and about 5 mg g-1 DW in G. turuturu and G. lanceola, respectively. The main MAA in Grateloupia lanceola was porphyra-334, which represented almost 100% of these compounds. Only some traces (<1%) of shinorine and palythine were found in this species. On the other hand, the dominant MAA in G. turuturu was shinorine, which represented approximately 92% of the total MAA content; palythine contributed about 7.5% while traces of asterina-330 were also found. [ABSTRACT FROM AUTHOR]
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- 2007
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227. Foraging strategies involved in habitat use of shorebirds at the intertidal area of Chongming Dongtan, China.
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Jing, Kai, Ma, Zhijun, Li, Bo, Li, Jinhua, and Chen, Jiakuan
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SHORE birds ,INTERTIDAL animals ,SALT marshes ,WETLANDS ,TIDAL flats ,CHARADRIIFORMES ,PREDATION - Abstract
Dense flocks of migratory shorebirds from diverse species often concentrate in the intertidal areas for stopover. Trophic structure, food partition, prey availability and selectivity, predation risk, and abiotic factors are often used to explain the differences in habitat use of coexisting shorebirds. We sampled the macrobenthos and surveyed the distribution of shorebird populations to study the effects of foraging strategies on the habitat use of shorebirds at Chongming Dongtan, an important stopover site for shorebirds on the East Asian–Australasian Flyway. Results show that the relative abundance of epifaunal macrobenthos in salt marshes was much higher than that in the bare flats, whereas the relative abundance of infaunal macrobenthos in salt marshes was much lower than that in bare flats. The relative abundance of two life forms of macrobenthos was similar in the transitional zones between the salt marshes and the bare flats. Shorebirds with different foraging strategies exhibited different habitat uses. Pause-travel shorebirds mainly utilized the salt-marsh fringes, while tactile continuous shorebirds relied heavily on the bare flats. There was no significant difference in habitat use for visual continuous shorebirds. The density of tactile continuous shorebirds was positively correlated with bivalve density, and that of visual continuous shorebirds positively with crustacean density. Meanwhile, the relative abundance of pause-travel foraging shorebirds was positively correlated with the relative abundance of epifaunal, but negatively with infaunal macrobenthos. In contrast, the relative abundance of tactile foraging shorebirds had a positive correlation with infaunal but a negative one with epifaunal life form. Therefore, foraging strategies may play important roles in shorebirds’ habitat use in intertidal areas. [ABSTRACT FROM AUTHOR]
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- 2007
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228. Vegetative and reproductive morphology of Gloiocladia repens (C. Agardh) Sánchez et Rodríguez-Prieto comb. nov. (Rhodymeniales, Rhodophyta), with a taxonomic re-assessment of the genera Fauchea and Gloiocladia.
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Rodríguez-Prieto, Conxi, Freshwater, D. Wilson, and Sánchez, Noemí
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RED algae ,RHODYMENIALES ,ALGAE ,SPECIES ,MORPHOLOGY - Abstract
A morphological and molecular study of Fauchea repens, the type species of Fauchea, (Faucheaceae, Rhodymeniales) and its comparison with Gloiocladia furcata, the type species of Gloiocladia, establishes that the two are closely related and belong in the same genus. Accordingly, we propose a new combination, Gloiocladia repens (C. Agardh) Sánchez et Rodríguez-Prieto, comb. nov., for the plant presently known as Fauchea repens (C. Agardh) Montagne et Bory in Montagne and designate a lectotype. We provide an emended description of the genus Gloiocladia, and transfer all the species presently placed in Fauchea to Gloiocladia. [ABSTRACT FROM AUTHOR]
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- 2007
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229. Building EDENs: The Rise of Environmentally Distributed Ecological Networks.
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Craine, Joseph M., Battersby, Jessamy, Elmore, Andrew J., and Jones, Andrew W.
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ECOLOGY ,RESEARCH ,ENVIRONMENTAL monitoring ,BIOTIC communities ,METHODOLOGY - Abstract
Environmentally distributed ecological networks (EDENs) are growing increasingly important in ecology, coordinating research in more disciplines and over larger areas than ever before, while supplanting post hoc syntheses of uncoordinated research. With the rise of multiple broadly focused, continental-scale EDENs, these networks will be directing an increasingly large proportion of resources in ecology, which warrants a review of their use. EDENs have become important for monitoring populations and ecosystems across regions, focusing on everything from butterflies to soil carbon. They are also pivotal for testing the generality of ecological relationships, testing ecological responses to experimental manipulations across space, ensuring uniform methodology, and compressing the lead time for syntheses. We identify 10 major steps to running EDENs and discuss four avenues of growth for EDENs in the near future. [ABSTRACT FROM AUTHOR]
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- 2007
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230. Wintering bird communities in newly-formed wetland in the Yangtze River estuary.
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Ma, Zhijun, Gan, Xiaojing, Choi, Chiyeung, Jing, Kai, Tang, Shimin, Li, Bo, and Chen, Jiakuan
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BIRD communities ,ANIMAL wintering ,HABITATS ,SPECIES diversity ,WATER birds ,PASSERIFORMES ,INVASIVE plants ,ESTUARIES ,WETLANDS - Abstract
We compared wintering bird communities and their habitats among three shoals at Jiuduansha, a newly-formed wetland in the Yangtze River estuary. The highest species richness and diversity were recorded in Shangsha, which is the highest shoal, and the highest abundance and lowest species diversity were recorded in Xiasha, which is the lowest shoal. Shangsha had the largest abundance of perching birds whereas Xiasha was the most abundant in waterbirds. Bird assemblages showed different associations with the different habitat types—perching birds were favored by reed ( Phragmites australis) communities, shallow water foragers and dabbling ducks preferred sea-bulrush ( Scirpus mariqueter) communities, and moist-soil foragers and gulls showed a preference for bare intertidal zones. All bird assemblages, however, avoided the smooth cordgrass ( Spartina alterniflora) communities, which are dominated by an alien invasive plant. The composition of avian communities was related to habitat types at the three shoals. Our results suggest that the newly-formed tidelands can provide suitable habitats for waterbirds and that the lower tidelands can attract more waterfowl than the higher tidelands. Because the shoal with low species diversity could have exclusive bird species, conservation efforts should not concentrate only on the area with high species diversity. The estuarine wetlands should be considered as a whole when conservation strategies are designed. The alien invasive plant should, moreover, be effectively controlled, to provide suitable habitats for birds. [ABSTRACT FROM AUTHOR]
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- 2007
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231. Can conditions experienced during migration limit the population levels of birds?
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Newton, Ian
- Abstract
Populations of migratory birds are usually considered to be limited by conditions in breeding or wintering areas, but some might be limited by conditions encountered on migration. This could occur at stopover sites where competition for restricted food supplies can reduce subsequent survival or breeding success, or during the flights themselves, when adverse weather can occasionally kill large numbers of individuals. Competition for food could act in a density-dependent manner and help to regulate populations, whereas weather effects are more likely to act in a density-independent manner. The evidence for these views is explored in this paper. When preparing for migration, birds must normally obtain more food per day than usual, in order to accumulate the body reserves that fuel their flights. Birds often concentrate in large numbers at particular stopover sites, where food can become scarce, thus affecting migratory performance. Rates of weight gain, departure weights, and stopover durations often correlate with food supplies at stopover sites, sometimes influencing the subsequent survival and reproductive success of individuals, which can in turn affect subsequent breeding numbers. Many studies have provided evidence for interference and depletion competition at stopover sites, relatively few for migration conditions influencing the subsequent breeding or survival of individuals, and even fewer for effects on subsequent breeding numbers. Migrants in flight occasionally suffer substantial mortality in storms, especially over water, sometimes involving many thousands of birds at a time. Other mass mortalities have resulted from atypical ‘winter-like’ weather, occurring soon after the arrival of summer migrants in their breeding areas or just before their departure in autumn. Again, many thousands of birds at a time have been killed in such incidents, causing reductions of 30–90% in local breeding densities. In some bird species, migration-related events can at times have substantial effects on the year-to-year changes in breeding population levels. Nonetheless, the difficulties involved in investigating migrating birds at different points on their migration routes have so far limited the number of studies on the influence of events during migration periods on population levels. [ABSTRACT FROM AUTHOR]
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- 2006
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232. Effect of medium molecular weight xanthan gum in rheology and stability of oil-in-water emulsion stabilized with legume proteins.
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Papalamprou, Evdoxia M, Makri, Eleousa A, Kiosseoglou, Vassilios D, and Doxastakis, Georgios I
- Published
- 2005
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233. Use of a spouted bed to improve the storage stability of wheat germ followed in paper and polyethlyene packages.
- Author
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Yöndem-Makascıoǧlu, Füsun, Gürün, Burak, Dik, Tunay, and Suzan Kıncal, N
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- 2005
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234. The conspecificity of Galaxaura apiculata and G. hystrix (Nemaliales, Rhodophyta) inferred from comparative morphology and rbcL and ITS1 sequences.
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Kurihara, Akira, Arai, Shogo, Shimada, Satoshi, and Masuda, Michio
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GALAXAURA ,RED algae ,MOLECULAR phylogeny ,MORPHOLOGY ,NEMALIALES - Abstract
In order to elucidate possible relationships among tetrasporophytic and gametophytic species of the red algal genus Galaxaura (Galaxauraceae, Nemaliales), we studied some tetrasporophytic and gametophytic species from Japanese waters, using morphological data, partial sequences of the large subunit of the RUBISCO (rbcL) gene and the nuclear rDNA internal transcribed spacer 1 (ITS1). Two morphologically similar species, G. apiculata Kjellman (tetrasporophytic species whose tetrasporangia are reported for the first time) and G. hystrix Kjellman (gametophytic species). Both of these were originally described from Japan and shared identical rbcL and ITS1 sequences. We conclude that these two algae constitute a single species, although their internal structures are distinct (particularly the shape of the cortical cells). Galaxaura hystrix is subsumed in G. apiculata and we provide an emended description of the species. Structural dimorphism among tetrasporophytic and gametophytic individuals within a single species was also confirmed in two additional species, G. falcata Kjellman and G. papillata Kjellman, whose type localities are also in Japan. [ABSTRACT FROM AUTHOR]
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- 2005
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235. Health care for hard-to-reach groups.
- Author
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Pfeil M and Howe A
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MEDICAL care ,HOMELESS persons ,TRAVEL hygiene ,REFUGEES - Abstract
Michael Pfeil and Amanda Howe show how creative use of personal medical services has transformed the health care on offer to hard-to-reach groups in Norwich. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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236. Newly Qualified Occupational Therapists 2003.
- Published
- 2003
237. Engaging People with Enduring Psychotic Conditions in Primary Mental Health Care and Occupational Therapy.
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Cook, Sarah and Howe, Amanada
- Published
- 2003
238. Un dibattito su 1984 di George Orwell.
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Arendt, Hannah, Howe, Irving, Meisl, John, Polanyi, Karl, and Cohen, Nathan
- Published
- 2002
239. Holocene coral reef rubble and its binding agents.
- Author
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Rasser, M.W. and Riegl, B.
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CORAL reefs & islands ,GEOLOGY - Abstract
Discusses the dynamics of coral reef disturbances, rubble formation and reef regeneration. Geological aspects of coral reef rubble; Agents of preliminary stabilization; Duration of binding; Geological implications of rubble occurrences.
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- 2002
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240. Birds at a Southern California beach: seasonality, habitat use and disturbance by human activiy.
- Author
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Lafferty, Kevin D.
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BIRDS ,BEACHES - Abstract
Analyzes birds density at Santa Barbara beach in California. Factors that determines variation in bird density and human activity; Percentage of humans and dogs that disturbed birds during a short observation period; Reasons behind variation in the frequency of bird species when disturbed by people.
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- 2001
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241. Hunting impact on waders in Spain: effects of species protection measures.
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Barbosa, Andres
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WILDLIFE conservation ,HUNTING - Abstract
Cites findings of a study undertaken to test the efficiency of species protection measures by examining the hunting impact on waders in Spain. Calculation of a hunting impact index on the basis of ringed bird recoveries; Decline in the hunting impact due to the change of protection level in a species group; Evidence on the accuracy of the ring recovery reports.
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- 2001
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242. A Screening Form for Identifying Mental Health Problems in Alcohol/Other Drug Dependent Persons.
- Author
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Carroll, Jerome F. X. and McGinley, John J.
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MENTAL health ,MENTAL health services ,THERAPEUTICS ,PATHOLOGICAL psychology - Abstract
The Mental Health Screening Form-III (MHSF-III; Carroll & McGinley, 2000) was designed to address the need in the chemical dependency field for an easy-to-use, brief (18 items answered "yes" or "no"), no-cost instrument that would identify clients with co-occurring psychiatric difficulties. The instrument requires minimal training to use. Most clients complete it in 15 minutes, including the inquiry recommended for all "yes" responses. Data is provided on the MHSF-III's reliability and validity, as well as a survey of 111 therapeutic community residents. The survey results noted underlying psychopathology in the majority of clients surveyed. [ABSTRACT FROM AUTHOR]
- Published
- 2001
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243. Revised memory and behavior problems checklist.
- Author
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Johnson MMS, Wackerbarth SB, and Schmitt FA
- Abstract
This study sought to examine the usefulness, reliability, and validity of the Revised Memory and Behavior Problems Checklist (Teri et al., 1992). Analyses included data from 952 patients. Cronbachs' alphas for sub-scales ranged from .80 to .99; factor analysis confirmed the structure of scales. Significant correlations with MMSE, parts of the Blessed-Roth Dementia Scale, and ratings of patient and caregiver functioning indicate good construct validity. Differences among mild, moderate and severe staged patients also indicate good validity. However, invariance across follow-up visits may be problematic for those using the scale to measure change due to disease progression, treatments or other interventions. [ABSTRACT FROM AUTHOR]
- Published
- 2001
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244. Waterbird assemblages and associated habitat characteristics of farm ponds in the Western Cape, South Africa.
- Author
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Froneman, Albert, Mangnall, Michael J., Little, Robin M., and Crowe, Timothy M.
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WATER birds ,HABITAT conservation ,FARM ponds - Abstract
Examines the relationship between waterbird assemblages and habitat characteristics of farm ponds in Western Cape, South Africa. Quantification of patterns for temporal and spatial variation of waterbirds; Structural diversity of waterbirds in terms of vegetation around the ponds; Need of farm ponds for conservation of waterbirds.
- Published
- 2001
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245. Search for neutrinoless double- β decay in Ge76 with 26 kg yr of exposure from the Majorana Demonstrator
- Author
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F. T. Avignone, R. L. Varner, Reyco Henning, A. M. Lopez, S. J. Meijer, T. S. Caldwell, J. Gruszko, R. J. Hegedus, B. Bos, M. Clark, T. Gilliss, C. Wiseman, Yu. Efremenko, V. Basu, I. S. Guinn, R. D. Martin, S. R. Elliott, Vladimir Yumatov, Eric W. Hoppe, C. J. Barton, Susanne Mertens, E. Yakushev, M. P. Green, Keith Rielage, H. Ejiri, M. Shirchenko, J. F. Wilkerson, D. Hervas Aguilar, C.-H. Yu, M. Buuck, W. Xu, G. K. Giovanetti, A. L. Reine, B. R. White, M ajorana, Richard T. Kouzes, Y-D. Chan, D. J. Tedeschi, Walter C. Pettus, J. Myslik, J. Rager, A. Piliounis, A. S. Barabash, B. Shanks, V. E. Guiseppe, M. A. Howe, C. R. Haufe, S. I. Alvis, C. Cuesta, I. Zhitnikov, Matthew Busch, C. D. Christofferson, Ralph Massarczyk, D. C. Radford, S. Vasilyev, S. I. Konovalov, G. Othman, M. F. Kidd, B. X. Zhu, F. E. Bertrand, Pinghan Chu, L. Hehn, I. J. Arnquist, N. W. Ruof, A. W. P. Poon, and J. A. Detwiler
- Subjects
Nuclear physics ,Physics ,MAJORANA ,010308 nuclear & particles physics ,13. Climate action ,Double beta decay ,0103 physical sciences ,Neutrino ,Experimental methods ,010306 general physics ,01 natural sciences ,Lower limit - Abstract
Author(s): Cuesta, C; Alvis, SI; Arnquist, IJ; Avignone, FT; Barabash, AS; Barton, CJ; Basu, V; Bertrand, FE; Bos, B; Busch, M; Buuck, M; Caldwell, TS; Chan, YD; Christofferson, CD; Chu, PH; Clark, M; Cuesta, C; Detwiler, JA; Efremenko, Y; Ejiri, H; Elliott, SR; Gilliss, T; Giovanetti, GK; Green, MP; Gruszko, J; Guinn, IS; Guiseppe, VE; Haufe, CR; Hegedus, RJ; Hehn, L; Henning, R; Hervas Aguilar, D; Hoppe, EW; Howe, MA; Kidd, MF; Konovalov, SI; Kouzes, RT; Lopez, AM; Martin, RD; Massarczyk, R; Meijer, SJ; Mertens, S; Myslik, J; Othman, G; Pettus, W; Piliounis, A; Poon, AWP; Radford, DC; Rager, J; Reine, AL; Rielage, K; Ruof, NW; Shanks, B; Shirchenko, M; Tedeschi, D; Varner, RL; Vasilyev, S; White, BR; Wilkerson, JF; Wiseman, C; Xu, W; Yakushev, E; Yu, CH; Yumatov, V; Zhitnikov, I; Zhu, BX | Abstract: The Majorana Collaboration is operating an array of high-purity Ge detectors to search for the neutrinoless double-β decay of Ge76. The Majorana Demonstrator consists of 44.1 kg of Ge detectors (29.7 kg enriched to 88% in Ge76) split between two modules constructed from ultraclean materials. Both modules are contained in a low-background shield at the Sanford Underground Research Facility in Lead, South Dakota. We present updated results on the search for neutrinoless double-β decay in Ge76 with 26.0±0.5 kg yr of enriched exposure. With the Demonstrator's energy resolution of 2.53 keV FWHM at Qββ, which is the best among all neutrinoless double-β decay experiments, we observe one event in the region of interest with 0.65 events expected from the estimated background, resulting in a lower limit on the Ge76 neutrinoless double-β decay half-life of 2.7×1025 yr [90% confidence level (CL)] with a median sensitivity of 4.8×1025 yr (90% CL). Depending on the matrix elements used, a 90% CL upper limit on the effective Majorana neutrino mass in the range of 200-433 meV is obtained. The measured background in the configurations with full shielding and optimized grounding is 11.9±2.0 counts/(FWHM t yr).
- Published
- 2019
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246. Physiological adjustments and arteriolar remodelling within skeletal muscle during acclimation to chronic hypoxia in the rat.
- Author
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Smith, Katharine and Marshall, Janice M.
- Published
- 1999
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247. Design improvements to cables and connectors in the Majorana Demonstrator
- Author
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G. K. Giovanetti, L. Hehn, J. Gruszko, J. E. Trimble, C. Cuesta, Pinghan Chu, B. Shanks, V. E. Guiseppe, C.M. O'Shaughnessy, T. Gilliss, M. Busch, R. D. Martin, I. J. Arnquist, N. W. Ruof, S. J. Meijer, A. W. P. Poon, M. Shirchenko, R. G. H. Robertson, A. S. Barabash, C. J. Barton, M. Buuck, B. X. Zhu, T. Bode, F. T. Avignone, Keith Rielage, D. C. Radford, Reyco Henning, A. M. Lopez, C. R. Haufe, Walter C. Pettus, Anne-Marie Suriano, S. I. Alvis, A. L. Reine, Eric W. Hoppe, J. A. Detwiler, I. Zhitnikov, T. S. Caldwell, C. Dunagan, V.B. Brudanin, M. P. Green, Chang-Hong Yu, A. W. Bradley, Ralph Massarczyk, S. Vasilyev, N. Abgrall, W. Xu, Y-D. Chan, F. E. Bertrand, G. Othman, K. J. Keeter, D. Tedeschi, I. S. Guinn, S. I. Konovalov, C. Wiseman, J. F. Wilkerson, B. R. White, M. A. Howe, V. Yumatov, Yu. Efremenko, J. Rager, H. Ejiri, Steven Elliott, Richard T. Kouzes, Kai Vetter, C. D. Christofferson, M. F. Kidd, R. L. Varner, Susanne Mertens, E. Yakushev, K. Vorren, and J. Myslik
- Subjects
Discrete mathematics ,Physics ,History ,Point contact ,MAJORANA ,Computer Science Applications ,Education - Abstract
Author(s): Haufe, CR; Reine, AL; Abgrall, N; Alvis, SI; Arnquist, IJ; Avignone, FT; Barabash, AS; Barton, CJ; Bertrand, FE; Bode, T; Bradley, AW; Brudanin, V; Busch, M; Buuck, M; Caldwell, TS; Chan, YD; Christofferson, CD; Chu, PH; Cuesta, C; Detwiler, JA; Dunagan, C; Efremenko, Y; Ejiri, H; Elliott, SR; Gilliss, T; Giovanetti, GK; Green, MP; Gruszko, J; Guinn, IS; Guiseppe, VE; Hehn, L; Henning, R; Hoppe, EW; Howe, MA; Keeter, KJ; Kidd, MF; Konovalov, SI; Kouzes, RT; Lopez, AM; Martin, RD; Massarczyk, R; Meijer, SJ; Mertens, S; Myslik, J; O'Shaughnessy, C; Othman, G; Pettus, W; Poon, AWP; Radford, DC; Rager, J; Rielage, K; Robertson, RGH; Ruof, NW; Shanks, B; Shirchenko, M; Suriano, AM; Tedeschi, D; Trimble, JE; Varner, RL; Vasilyev, S; Vetter, K; Vorren, K; White, BR; Wilkerson, JF; Wiseman, C; Xu, W; Yakushev, E; Yu, CH; Yumatov, V; Zhitnikov, I; Zhu, BX | Abstract: The MAJORANA DEMONSTRATOR is an experiment constructed to search for neutrinoless double-beta decays in germanium-76 and to demonstrate the feasibility to deploy a ton-scale experiment in a phased and modular fashion. It consists of two modular arrays of natural and 76Ge-enriched germanium p-Type point contact detectors totaling 44.1 kg, located at the 4850' level of the Sanford Underground Research Facility in Lead, South Dakota, USA. The DEMONSTRATOR uses custom high voltage cables to bias the detectors, as well as custom signal cables and connectors to read out the charge deposited at each detectors point contact. These low-mass cables and connectors must meet stringent radiopurity requirements while being subjected to thermal and mechanical stress. A number of issues have been identified with the currently installed cables and connectors. An improved set of cables and connectors for the MAJORANA DEMONSTRATOR are being developed with the aim of increasing their overall reliability and connectivity. We will discuss some of the issues encountered with the current cables and connectors as well as our improved designs and their initial performance.
- Published
- 2020
- Full Text
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248. Progress Toward A 2νββ Measurement For The Majorana Demonstrator
- Author
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Yuen-Dat Chan, G. K. Giovanetti, J. F. Wilkerson, K. Vorren, I. J. Arnquist, N. W. Ruof, C. Wiseman, A. W. P. Poon, C. R. Haufe, B. Shanks, M. A. Howe, J. Gruszko, S. I. Alvis, F. T. Avignone, I. S. Guinn, R. L. Varner, J. E. Trimble, V. E. Guiseppe, A. S. Barabash, Reyco Henning, Ralph Massarczyk, Pinghan Chu, A. M. Lopez, T. Gilliss, I. Zhitnikov, Matthew Busch, V. B. Brudanin, C. Dunagan, C.-H. Yu, S. Vasilyev, N. Abgrall, J. Rager, R. D. Martin, Keith Rielage, K. J. Keeter, R. G. H. Robertson, C. D. Christofferson, F. E. Bertrand, M. P. Green, A. W. Bradley, H. Ejiri, D. J. Tedeschi, M. F. Kidd, B. X. Zhu, E. Yakushev, Susanne Mertens, Eric W. Hoppe, T. S. Caldwell, J. Myslik, S. J. Meijer, S. I. Konovalov, V. Yumatov, G. Othman, S. R. Elliott, Yu. Efremenko, B. R. White, Anne-Marie Suriano, J. A. Detwiler, L. Hehn, C. Cuesta, C.M. O'Shaughnessy, M. Shirchenko, Richard T. Kouzes, T. Bode, D. C. Radford, Kai Vetter, Walter C. Pettus, A. L. Reine, W. Xu, C. J. Barton, and M. Buuck
- Subjects
Physics ,Nuclear physics ,History ,MAJORANA ,Point contact ,Muon ,Energy spectrum ,Computer Science Applications ,Education - Abstract
Author(s): Gilliss, T; Abgrall, N; Alvis, SI; Arnquist, IJ; Avignone, FT; Barabash, AS; Barton, CJ; Bertrand, FE; Bode, T; Bradley, AW; Brudanin, V; Busch, M; Buuck, M; Caldwell, TS; Chan, YD; Christofferson, CD; Chu, PH; Cuesta, C; Detwiler, JA; Dunagan, C; Efremenko, Y; Ejiri, H; Elliott, SR; Giovanetti, GK; Green, MP; Gruszko, J; Guinn, IS; Guiseppe, VE; Haufe, CR; Hehn, L; Henning, R; Hoppe, EW; Howe, MA; Keeter, KJ; Kidd, MF; Konovalov, SI; Kouzes, RT; Lopez, AM; Martin, RD; Massarczyk, R; Meijer, SJ; Mertens, S; Myslik, J; O'Shaughnessy, C; Othman, G; Pettus, W; Poon, AWP; Radford, DC; Rager, J; Reine, AL; Rielage, K; Robertson, RGH; Ruof, NW; Shanks, B; Shirchenko, M; Suriano, AM; Tedeschi, D; Trimble, JE; Varner, RL; Vasilyev, S; Vetter, K; Vorren, K; White, BR; Wilkerson, JF; Wiseman, C; Xu, W; Yakushev, E; Yu, CH; Yumatov, V; Zhitnikov, I; Zhu, BX | Abstract: The MAJORANA DEMONSTRATOR is a 76Ge-based neutrinoless double-beta decay (0νββ) experiment. Staged at the 4850 ft level of the Sanford Underground Research Facility, the DEMONSTRATOR operates an array of high-purity p-Type point contact Ge detectors deployed within a graded passive shield and an active muon veto system. The present work concerns the two-neutrino double-beta decay mode (2νββ) of 76Ge. For Ge detectors, having superior energy resolution (0.1%), this mode poses negligible background to the 0νββ mode, even for a ton-scale experiment. However, the measurement of the 2νββ mode allows for careful systematics checks of active detector mass, enrichment fraction, and pulse shape discrimination cuts related to both the 0νββ and 2νββ decay modes. A precision measurement of the 2νββ shape also allows searches for spectral distortions, possibly indicative of new physics, including 0νββχ. Work is underway to construct a full experimental background model enabling a Bayesian fit to the measured energy spectrum and extraction of a precise 2νββ spectrum and half-life.
- Published
- 2020
- Full Text
- View/download PDF
249. Initial results from the Majorana Demonstrator
- Author
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Ralph Massarczyk, J. Gruszko, M. Shirchenko, V. B. Brudanin, W. Xu, J. F. Wilkerson, S. Vasilyev, J. Rager, Keith Rielage, N. Abgrall, C. R. Haufe, T. Bode, C. J. Barton, S. I. Alvis, M. Buuck, C. Wiseman, G. K. Giovanetti, F. E. Bertrand, B. Bos, Walter C. Pettus, G. Othman, C. Dunagan, I. Zhitnikov, Matthew Busch, J. E. Trimble, A. W. Bradley, Eric W. Hoppe, Pinghan Chu, D. J. Tedeschi, I. J. Arnquist, N. W. Ruof, Yu. Efremenko, T. S. Caldwell, E. Yakushev, A. S. Barabash, C.-H. Yu, M. F. Kidd, I. S. Guinn, L. Hehn, B. Shanks, C. D. Christofferson, V. E. Guiseppe, B. X. Zhu, A. W. P. Poon, C. Cuesta, D. C. Radford, T. Gilliss, R. D. Martin, R. G. H. Robertson, A. L. Reine, K. Vorren, Kai Vetter, M. A. Howe, Richard T. Kouzes, B. R. White, S. J. Meijer, M. P. Green, H. Ejiri, Susanne Mertens, K. J. Keeter, C. O׳Shaughnessy, F. T. Avignone, R. L. Varner, Reyco Henning, A. M. Lopez, Chan Y-D., J. Myslik, S. I. Konovalov, V. Yumatov, S. R. Elliott, Anne-Marie Suriano, and J. A. Detwiler
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Physics ,History ,MAJORANA ,Particle physics ,Full data ,Neutrino ,Computer Science Applications ,Education - Abstract
Author(s): Elliott, SR; Abgrall, N; Arnquist, IJ; Avignone, FT; Barabash, AS; Bertrand, FE; Bradley, AW; Brudanin, V; Busch, M; Buuck, M; Caldwell, TS; Chan, YD; Christofferson, CD; Chu, PH; Cuesta, C; Detwiler, JA; Dunagan, C; Efremenko, Y; Ejiri, H; Fullmer, A; Galindo-Uribarri, A; Gilliss, T; Giovanetti, GK; Green, MP; Gruszko, J; Guinn, IS; Guiseppe, VE; Henning, R; Hoppe, EW; Howe, MA; Jasinski, BR; Keeter, KJ; Kidd, MF; Konovalov, SI; Kouzes, RT; Leon, J; Lopez, AM; Macmullin, J; Martin, RD; Massarczyk, R; Meijer, SJ; Mertens, S; Orrell, JL; O'Shaughnessy, C; Poon, AWP; Radford, DC; Rager, J; Rielage, K; Robertson, RGH; Romero-Romero, E; Shanks, B; Shirchenko, M; Suriano, AM; Tedeschi, D; Trimble, JE; Varner, RL; Vasilyev, S; Vetter, K; Vorren, K; White, BR; Wilkerson, JF; Wiseman, C; Xu, W; Yakushev, E; Yu, CH; Yumatov, V; Zhitnikov, I | Abstract: Neutrinoless double-beta decay searches seek to determine the nature of neutrinos, the existence of a lepton violating process, and the effective Majorana neutrino mass. The Majorana Collaboration is assembling an array of high purity Ge detectors to search for neutrinoless double-beta decay in 76Ge. The Majorana Demonstrator is composed of 44.8 kg (29.7 kg enriched in 76Ge) of Ge detectors in total, split between two modules contained in a low background shield at the Sanford Underground Research Facility in Lead, South Dakota. The initial goals of the Demonstrator are to establish the required background and scalability of a Ge-based, next-generation, tonne-scale experiment. Following a commissioning run that began in 2015, the first detector module started physics data production in early 2016. We will discuss initial results of the Module 1 commissioning and first physics run, as well as the status and potential physics reach of the full Majorana Demonstrator experiment. The collaboration plans to complete the assembly of the second detector module by mid-2016 to begin full data production with the entire array.
- Published
- 2020
- Full Text
- View/download PDF
250. Women in Systematics.
- Author
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Lipscomb, D
- Published
- 1995
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