104 research outputs found

    Temporal relationship between climate variability, Prosopis juliflora invasion and livestock numbers in the drylands of Magadi, Kenya

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    A study was conducted to determine the association of climate variability, Prosopis juliflora spread,Ā and other vegetation trends with livestock population dynamics in Kajiado County, Kenya. MonthlyĀ rainfall, mean monthly temperatures, cattle, sheep and goats populations from January 2000 toĀ December 2014, were analyzed to determine time series trends. Normalized Difference Vegetation IndexĀ (NDVI) data derived from moderate resolution imaging spectroradiometer (MODIS) 250 m satelliteĀ imageries for 2000 to 2014 were used to determine the temporal dynamics of P. juliflora invasion in theĀ study area. Both temperature and rainfall trends showed marked variability over the period under study.Ā The mean monthly temperatures during the long dry season increased erratically from 33Ā°C in 2000 toĀ 37Ā°C in 2014. Moreover, the rainfall during the wettest season was 600 mm in 2000 and 250 mm in 2014.Ā During the study period, divergence from the long term mean rainfall (450 mm) decreased from 585 toĀ 403 mm. At the same time cattle population decreased, sheep and goats populations remained static. P.Ā juliflora invasion correlated positively (r=0.2; P<0.05) with mean monthly temperature and negativelyĀ (r=-0.4; P<0.05) with rainfall and other vegetation cover in drier parts, but not in the higher altitude andĀ wetter parts of the study area. It also correlated negatively with cattle populations (r=-0.4; P<0.05). In theĀ 1980ā€™s, bushlands and woodlands constituted 95 and 5% of the land cover, while in 2008, herbaceousĀ vegetation, shrublands, and open trees together with bare areas constituted 50, 30, and 22%,Ā respectively; out of which 70% had been taken over by Prosopis in 2014. This study demonstrated thatĀ even though the trends showed that cattle population decreased as climate variability and ProsopisĀ invasion increased, there was no significant correlation among the attributes, over the period underĀ study.Key words: Climate, drylands, livestock, Prosopis juliflora, variability vegetation, trends, mesquite

    Normal values for nuclear cardiology: Japanese databases for myocardial perfusion, fatty acid and sympathetic imaging and left ventricular function

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    Myocardial normal databases for stress myocardial perfusion study have been created by the Japanese Society of Nuclear Medicine Working Group. The databases comprised gender-, camera rotation range- and radiopharmaceutical-specific data-sets from multiple institutions, and normal database files were created for installation in common nuclear cardiology software. Based on the electrocardiography-gated single-photon emission computed tomography (SPECT), left ventricular function, including ventricular volumes, systolic and diastolic functions and systolic wall thickening were also analyzed. Normal databases for fatty acid imaging using 123I-beta-methyl-iodophenyl-pentadecanoic acid and sympathetic imaging using 123I-meta-iodobenzylguanidine were also examined. This review provides lists and overviews of normal values for myocardial SPECT and ventricular function in a Japanese population. The population-specific approach is a key factor for proper diagnostic and prognostic evaluation

    Soil fertility in flooded and non-flooded irrigated rice systems

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    The lowland rice system in Asia makes a major contribution to the global rice supply and is often cited as an example of a sustainable system in which two or three crops of rice are grown in sequence under submerged conditions. However, water shortages are becoming critical in some regions for lowland rice cultivation; and there is high potential in exploring rice cultivation under moisture regimes that save water and also increase productivity. The objective of this article therefore is to analyze the consequences of switching growing of rice from flooded to aerobic conditions on soil fertility and its management. Fertility advantages of submerged rice include amelioration of chemical fertility, preferential accumulation of organic matter and improved availability of major, secondary and selected micronutrients, which contribute to the long-term maintenance of soil fertility and sustainability of the lowland rice system. However, the fertility problems under aerobic rice are better addressed with the crop as a component of a cropping system because continuous growing of aerobic rice in sequence does not seem sustainable due to complex, site-specific chemical and biological constraints

    Impact of mediastinal, liver and lung 123I-metaiodobenzylguanidine (123I-MIBG) washout on calculated 123I-MIBG myocardial washout

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    PURPOSE: In planar (123)I-metaiodobenzylguanidine ((123)I-MIBG) myocardial imaging mediastinum (M) activity is often used as a background correction in calculating "washout" (WO). However, the most likely sources for counts that might produce errors in estimating myocardial (Myo) activity are lung (Lu) and liver (Li), which typically have higher counts/pixel (cpp) than M. The present study investigated the relationship between changes in Lu, Li and Myo activity between early and late planar (123)I-MIBG images, with comparison to M as the best estimator of non-specific background activity. METHODS: Studies on 98 subjects with both early (e) and late (l) planar (123)I-MIBG images were analysed. There were 68 subjects with chronic heart failure (CHF), 14 with hypertension (HTN) but no known heart disease and 16 controls (C). For each image, regions of interest (ROIs) were drawn: an irregular whole Myo, Lu, upper M and Li. For each ROI, WO was calculated as [(cpp(e)-cpp(l:decay corrected))/cpp(e)]x100%. RESULTS: Multivariable forward stepwise regression analysis showed that overall a significant proportion of the variation in Myo WO could be explained by a model containing M WO and Lu WO (37%, p < 0.001). Only in controls was M WO the sole variable explaining a significant proportion of the variation in Myo WO (27%, p = 0.023). CONCLUSION: Although increased Myo WO in CHF subjects reflects disease severity, part of the count differences measured on planar (123)I-MIBG myocardial images likely reflects changes in the adjacent and surrounding Lu tissue. The results for the controls suggest that this is the only group where a mediastinum correction alone may be appropriate for cardiac WO calculation

    Novel iodinated tracers, MIBG and BMIPP, for nuclear cardiology

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    With the rapid growth of molecular biology, in vivo imaging of such molecular process (i.e., molecular imaging) has been well developed. The molecular imaging has been focused on justifying advanced treatments and for assessing the treatment effects. Most of molecular imaging has been developed using PET camera and suitable PET radiopharmaceuticals. However, this technique cannot be widely available and we need alternative approach. 123I-labeled compounds have been also suitable for molecular imaging using single-photon computed tomography (SPECT) 123I-labeled meta-iodobenzylguanidine (MIBG) has been used for assessing severity of heart failure and prognosis. In addition, it has a potential role to predict fatal arrhythmia, particularly for those who had and are planned to receive implantable cardioverter-defibrillator treatment. 123I-beta-methyl-iodophenylpentadecanoic acid (BMIPP) plays an important role for identifying ischemia at rest, based on the unique capability to represent persistent metabolic alteration after recovery of ischemia, so called ischemic memory. Since BMIPP abnormalities may represent severe ischemia or jeopardized myocardium, it may permit risk analysis in CAD patients, particularly for those with chronic kidney disease and/or hemodialysis patients. This review will discuss about recent development of these important iodinated compounds

    Computer-Based Soil Data Management System (COSMAS): Its Function and Use

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    The large amount of data accumulated in soil surveys should always be available for research and practical use in agriculture, rural planning, and so on. For this purpose, the data must be managed by a well-organized computer-based system. This paper describes the basic function and organization of the system (COSMAS) now under development by the authors. The site description and horizon observation of a soil survey are written on a standardized card in numerical and letter codes. Both the location of the observation site and the boundaries of the general soil map in the coordinate system of the base map are recorded by means of a peripheral device, the tablet. Thus data obtained in the field and in the laboratory are filed by means of the packaged program, SPSS (Statistical Package for the Social Sciences). Four files are now in operation: site description, horizon description, analytical data, and cartographic files, all of which can be cross-referenced with one another. SPSS performs not only statistical analysis, but also such file management as data selection, recoding, and transformation. The processed information can be obtained in a form inherent to SPSS, or in various forms by programs developed by the authors, for example, soil survey report in text, contour maps, soil attribute maps, and transect-attribute diagrams. As an example of its use, it would be explained here how COSMAS helped us to understand the distribution pattern of different soil materials in a given area
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