256 research outputs found

    USCID fourth international conference

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    Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.A decision-making software tool for monitoring irrigation of small farms in heterogeneous environments (OSIRI) was developed at the request of small-scale sugarcane farmers on the island of Réunion (France) hampered by variable climate and soil conditions. This program, which is based on a simple water balance simulation model coupled with a comprehensive set of decision rules, was designed to provide farmers with customized advice on discrete irrigation units and to simulate irrigation system scenarios so as to optimize their performance. The basic equations and main decision rules of OSIRI, as well as the software features, were given in Chopart et al. (2007). A detailed experimental study was carried out on a 5000 m2 irrigated sugarcane field to compare the performance of this tool with the currently used method based on maximum crop water requirements (control). The results showed that OSIRI reasonably well simulates actual evapotranspiration and drainage below the sugarcane root zone. Moreover, it allowed savings of about 26% in irrigation delivery throughout the crop cycle as compared with the control method, without a significant decrease in yield, and irrigation water productivity increased by 25%. The results of a survey of 25 farmers using OSIRI showed that it is a well accepted valuable decision-making tool

    Image-guidance in endoscopic pituitary surgery: an in-silico study of errors involved in tracker-based techniques

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    Background: Endoscopic endonasal surgery is an established minimally invasive technique for resecting pituitary adenomas. However, understanding orientation and identifying critical neurovascular structures in this anatomically dense region can be challenging. In clinical practice, commercial navigation systems use a tracked pointer for guidance. Augmented Reality (AR) is an emerging technology used for surgical guidance. It can be tracker based or vision based, but neither is widely used in pituitary surgery. Methods: This pre-clinical study aims to assess the accuracy of tracker-based navigation systems, including those that allow for AR. Two setups were used to conduct simulations: (1) the standard pointer setup, tracked by an infrared camera; and (2) the endoscope setup that allows for AR, using reflective markers on the end of the endoscope, tracked by infrared cameras. The error sources were estimated by calculating the Euclidean distance between a point’s true location and the point’s location after passing it through the noisy system. A phantom study was then conducted to verify the in-silico simulation results and show a working example of image-based navigation errors in current methodologies. Results: The errors of the tracked pointer and tracked endoscope simulations were 1.7 and 2.5 mm respectively. The phantom study showed errors of 2.14 and 3.21 mm for the tracked pointer and tracked endoscope setups respectively. Discussion: In pituitary surgery, precise neighboring structure identification is crucial for success. However, our simulations reveal that the errors of tracked approaches were too large to meet the fine error margins required for pituitary surgery. In order to achieve the required accuracy, we would need much more accurate tracking, better calibration and improved registration techniques

    Langtidsovervåking av miljøkvaliteten i kystområdene av Norge. Årsrapport 1996

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    Kystovervåkingsprogrammet skal gi en oversikt over miljøtilstanden m.h.t. næringssalter og effektene av disse på alge- og dyresamfunn fra svenskegrensen til Fedje. Utvikling over tid overvåkes innen fagdisiplinene hydrografi, hydrokjemi, planteplankton, bløtbunnsfauna og hardbunnsflora og -fauna. Året 1996 ble innledet med en kald vinter og vår. Vanntemperaturen i Skagerrak ned til ca. 25 m var i januar - februar kaldere enn gjennomsnittet for 1980-1990, mens samme periode i 1995 var uvanlig varm. Til forskjell fra 1995 var det ingen flom på kontinentet eller på Østlandet i 1996, og det resulterte i små tilførsler av næringssalter fra land. Sammenlignet med langtidsobservasjoner fra Arendalstasjonene (1980-90) var 1996 et år med lavere næringssaltkonsentrasjoner i de øvre vannmasser vinter og vår og for de løste næringssaltene også tildels sommeren og høsten. C/N-forholdet i stortare fra Sørlandskysten var meget høyt og kan indikere næringsbegrenset algevekst på Sørlandskysten sommeren 1996. Utbredelse og forekomst av fastsittende alger var generelt sett noe redusert i 1996 i forhold til 1995 og mer lik hva som ble funnet i 1993/94. Variasjonene kan sees i sammenheng med vinter/vår temperaturene. Fortsatt tilvekst av tareskog i Skagerrak gjør stasjonene mer homogene. Forekomst av organismer på bløt- og hardbunn viste en normal øst-vest gradient, med økende artsantall og diversitet mot vest. Bløtbunnsfaunaen viste ingen større endringer fra 1995 til 1996. For enkelte stasjoner ble det funnet en nedgang i individtall, mens det ble funnet en økning for andre stasjoner, uten at det er noen klar årsakssammenheng eller tendens i variasjonene

    Idoneidad de especies vegetales para el desarrollo poblacional de Neophilaenus campestris (Fallén) (Hemiptera: Aphrophoridae)

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    El conocimiento de la biología y dinámica poblacional de los insectos vectores de la bacteria fitopatógena Xylella fastidiosa Wells et al., 1987, es fundamental para llevar a cabo un adecuado control de las enfermedades que produce en plantas cultivadas, por medio del manejo de dichos vectores. En la Comunidad Valenciana, en la Zona Demarcada por presencia de la bacteria localizada en la provincia de Alicante, Philaenus spumarius (Linnaeus, 1758), Neophilaenus campestris (Fallén, 1805) y Neophilaenus lineatus (Linnaeus, 1758) han evidenciado portar la bacteria, si bien solo las dos primeras especies son vectores reconocidos en Europa

    Estatinas y factor de necrosis tumoral alfa

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    Las Estatinas son elaboradas para eliminar el riesgo cardiovascular al reducir LDL (colesterol de baja densidad), pero el evento coronario agudo sigue ocurriendo en 40% de las personas que presentaban colesterol total por debajo de lo normal. El objetivo de este estudio fue evaluar si dentro de los efectos pleiotropicos de las estatinas se podía reducir el FNTα y con ello probar sus efectos antioxidantes e inflamatorios. Se evaluaron 21 pacientes, con hipercolesterolemia al ingreso y después de 8 semanas de recibir 40 mg de Simvastatina, se le realizó: Colesterol, Triglicéridos, HDL, LDL, Glicemia, Creatinina, Acido Úrico, PCR, IL-1, IL-6, IL-10, TNFα, SOD y 8-Isoprostanos F2. Se utilizo la prueba t de student. La estatina, mas allá de disminuir LDL es eficaz en disminuir variables que participan en la respuesta oxidativa e inflamatoria, mecanismo fisiopatologico constantes en las enfermedades cardiovasculares y metabólicas.Statins are developed to eliminate the risk of heart disease by reducing LDL (low density), but the acute coronary event still happened in 40% of those who had total cholesterol below normal. The aim of this study was to assess whether in the pleiotropic effects of statins could reduce TNF α and thus prove its antioxidant and inflammatory effects. We evaluated 21 patients with hypercholesterolemia on admission and after 8 weeks of receiving 40 mg simvastatin, we evaluated: Cholesterol, Triglycerides, HDL, LDL, Glucose, Creatinine, uric acid, CRP, IL-1, IL-6, IL-10, TNF, SOD and 8-isoprostane F2α. T test was used to student. The statin beyond to reduced LDL is effective in decreasing variables involved in the inflammatory response, consistent pathophysiological mechanism in cardiovascular and metabolic diseases

    Langtidsovervåking av miljøkvaliteten i kystområdene av Norge. Kystovervåkingsprogrammet. Årsrapport for 2009

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    Sammendrag Rapporten beskriver miljøkvaliteten i kystområdene av Sør-Norge i 2009, med spesiell fokus på tilstand og utvikling i næringssalttilførsler, vannkvalitet og det biologiske mangfoldet i plankton-, bløt- og hardbunns­samfunn. NAO-indeksen for vinteren 2009 var negativ, på grunn av kaldt klima i februar. Eutrofiutviklingen har vært positiv de siste årene. Vannføringen i Glomma var noe større enn normalt i 2009, men tilførslene av næringsalter fra elver har gått noe ned. Vannkvaliteten i Skagerrak var i 2009 i klasse God eller Meget god med hensyn til N, P, siktdyp og klorofyll, unntatt i Ytre Oslofjord hvor hvor det ble registrert tot-P og siktdyp i klasse Mindre god. For hele perioden er det i Skagerrak en tendens til avtakende risiko for opp­blom­string av skadelige alger. Økende oksygenforbruk i Risørfjorden og avtagende oksygen­konsentrasjoner i kystvannet generelt, gjenspeiler økt organisk belastning langs kysten. I 2009 var siktdypet som gjennomsnittet for 1991-2005, men i februar var sikten dårligere langs Skagerrakkysten. Det kan skyldes våroppblomstringen og innstrømmende vann fra Kattegat. 2009 var det åttende året på rad med lav algemengde. En kraftig våroppblomstring kom i februar. Lite alger kan være årsaken til nedgang i biomassen av kopepoder. Det ble registrert flere sørlige arter i våre områder i 2009. Tilstanden for bunndyr, både på bløtbunn og hardbunn, var generelt god i 2009, men tilstanden for tare har vært dårligere de siste to år.Klima- og forurensningsdirektoratet (Klif

    Environmental and spatial risk factors for the larval habitats of Plasmodium knowlesi vectors in Sabah, Malaysian Borneo.

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    Land-use changes, such as deforestation and agriculture, can influence mosquito vector populations and malaria transmission. These land-use changes have been linked to increased incidence in human cases of the zoonotic malaria Plasmodium knowlesi in Sabah, Malaysian Borneo. This study investigates whether these associations are partially driven by fine-scale land-use changes creating more favourable aquatic breeding habitats for P. knowlesi anopheline vectors. Using aerial remote sensing data, we developed a sampling frame representative of all land use types within a major focus of P. knowlesi transmission. From 2015 to 2016 monthly longitudinal surveys of larval habitats were collected in randomly selected areas stratified by land use type. Additional remote sensing data on environmental variables, land cover and landscape configuration were assembled for the study site. Risk factor analyses were performed over multiple spatial scales to determine associations between environmental and spatial variables and anopheline larval presence. Habitat fragmentation (300 m), aspect (350 m), distance to rubber plantations (100 m) and Culex larval presence were identified as risk factors for Anopheles breeding. Additionally, models were fit to determine the presence of potential larval habitats within the areas surveyed and used to generate a time-series of monthly predictive maps. These results indicate that land-use change and topography influence the suitability of larval habitats, and may partially explain the link between P. knowlesi incidence and deforestation. The predictive maps, and identification of the spatial scales at which risk factors are most influential may aid spatio-temporally targeted vector control interventions

    Increased chromosomal stability in cultures of ovarian tumours of low malignant potential compared to cystadenomas

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    Cell cultures of ovarian cystadenomas transfected with SV40 large T antigen are not immortal because they invariably reach a phenomenon called crisis, which is triggered in part by telomere attrition. Recovery from crisis may be an integral component of the malignant transformation process. We reported earlier that such ovarian cystadenoma cell cultures undergo severe changes in DNA ploidy as they approach crisis and that such changes are an important determinant of crisis independent of telomere attrition. Here, we show that in sharp contrast to these benign ovarian tumours, the DNA content of ovarian tumours of low malignant potential (LMP) was remarkably stable as they approached crisis, suggesting that telomere attrition was the main determinant of this mortality checkpoint. Lack of a ploidy-based crisis was not due to loss of expression of a functional SV40 large T antigen protein. We conclude that ovarian LMP tumours are characterised by increased numerical chromosomal stability compared to cystadenomas. This might account for the fact that most LMP tumours are diploid or near diploid in vivo. This fundamental difference in chromosomal stability between ovarian cystadenomas and LMP tumours also suggests potential differences in predisposition to progression to malignancy between these two ovarian tumour subtypes
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