Problem Of Large Areas Research Articles

Effect of Se-Enriched Irrigation Water and Soil Texture on Biomass Production and Elemental Composition of Green Pea and Carrot and Their Contribution to Human Se Intake

Selenium (Se)-deficient diets are a problem in large areas of the world and can have serious health consequences, thus, the biofortification of foods with Se has been an important research field for several decades. The effect of Se-enriched irrigation water was investigated regarding the Se concentration in green peas and carrots. A pot experiment was set up in a greenhouse with irrigation water containing 0, 100, and 500 µg Se L−1 with sand, silty sand and silt soil types. Most of the treatments only slightly reduced the biomass, while the 500 µg Se L−1 treatment caused a significant decrease in the dry weight of carrot root. Treatment with irrigation water containing 100 µg Se L−1 increased the Se content in green peas and carrots 76 and 75 times, respectively, producing foodstuffs where 100 g of a fresh product covered 395% and 92% of the recommended dietary allowance, respectively, averaged over the three soil types. The Se concentration was higher for green peas in sand and carrots in silt. The treatments had little effect on the concentrations of other nutrients. The enrichment of irrigation water with Se may thus be a suitable method for the biofortification and production of functional food under certain conditions.

Simplified Flat Coordinate Model for Northern Parts of Arabian Gulf

The method of coordinate conversion is still considered important and laborious due to the shift from the spatial ellipsoidal (geographic) to the flat planned system. The most common method uses a contiguous UTM system as one of the most reliable systems in the conversion process; however, this system faces a problem in large areas that contain more than one zone. The goal of this research is to create a simple and low computational cost model to represent a non-contiguous semi-UTM geographic coordinates for confined regions of the globe. The considered region taken in this study is the northern parts of Arabian Gulf (including parts of Iraq, Kuwait, Iran, and Saudi Arabia). The determined mathematical model was based on using two dimensional Taylor sequence. The most accurate representation met in this study was based on the 6th two dimensional polynomial. The estimation of equations’ coefficients was done using the least square criterion for the overall error of estimating coordinate values of either (latitude, longitude) or (Easting, Northing). The two basic determinations were applied for the forward and the backward; in the first step, the conversion of coordinates was calculated from the ellipsoidal coordinates (i.e., Longitude, Latitude) to UTM (WGS84) coordinates (i.e., Easting, Northing) and vice versa.
 The attained results indicated that the mathematical model used is successful for achieving the conversion process. With the use of the 6th order 2D-polynomial equations, a very small error of less than 1 m was achieved in the Easting and Northing coordinates.

Spatiotemporal forecast with local temporal drift applied to weather patterns in Patagonia

Geostatistics was developed to generate maps or 3D models interpolating observed values in space. The so-called spatiotemporal geostatistic applies the same principles to estimate observed values that have both spatial and temporal distribution. Moreover, time series analysis can decompose and extrapolate its main trends and seasonality, preparing data for geostatistical assumptions. Using this principle, this study aims to decompose the time series of a spatiotemporal dataset as external drifts and estimate its residuals by spatiotemporal kriging. Since each observation point is a time series, it is possible to decompose its trend and seasonality locally and map its parameters, preferable, by traditional geostatistics. Aftermath, it is possible to extrapolate the trend and seasonality at each pixel. This procedure can achieve great long-term forecasting maps even in regions with poor sampling due to its time series analysis. As well as, the geostatistics guarantee that the spatio-temporal correlation is maintained. This method is especially good for prediction in regions that the time series pattern depends on its location, which is a common problem in large areas and the problem is worsened in poorly sampled regions. This study presents a 10 years map forecast (2008–2017) comparison by spatiotemporal geostatistics, the first with original data, with ARIMA Models Panels, then with global decomposition, finally, with the local decomposition approach. The target variable is temperature captured by the 18 active weather stations in Patagonia between 1973 and 2007. To validate the results, they are compared to Land Surface Temperature (LST), which is an image product MOD11C3 derived from the MODIS sensor onboard on Terra/Aqua satellites. The proposed method can make long-term forecasts with low error, low smoothing effect and similar spatiotemporal statistics (mean and variance) of the stations and the LST product. Finally, its results are comparable with the ARIMA Models Panels with the advantage that it can generate maps with spatiotemporal correlation and better than the often-used methods (st-kriging and global decomposition) to forecast large areas maps.

Spatial modelling of gully erosion in Mazandaran Province, northern Iran

Gully erosion is one of the most severe environmental problems in large areas of Iran. The spatial distribution of gully erosion and its susceptibility zonation was studied using different bivariate statistical models, such as frequency ratio (FR), weights of evidence (WofE), and index of entropy (IofE). For this purpose, 109 gully erosion locations were identified and divided into training (70%) and validating (30%) datasets. Effective factors, including elevation, slope aspect, slope degree, slope-length (LS), topographical wetness index (TWI), plan curvature, profile curvature, land use, lithology, distance from river, drainage density, and distance from road were selected to develop maps of gully erosion susceptibility. The spatial relationship between gully erosion and each effective factor was calculated by the mentioned models. The relative operating characteristic (ROC) curve was implemented for evaluating the accuracy of the applied predictive models. Results indicated that frequency ratio model had better performance (80.4%) than the weight of evidence (79.5%) and index of entropy (79%) models. The produced gully erosion susceptibility maps can be helpful to make decisions for soil and water planning and management and finally sustainable development in the Valasht watershed.

Numerical limit analysis of three-dimensional slope stability problems in catchment areas

Risk analysis of existing slopes in catchment areas requires quantification of their stability. This quantification becomes particularly difficult when dealing with larger areas under 3D conditions and including saturated and unsaturated water flow. This paper proposes the use of an effective numerical procedure to solve three-dimensional slope stability problems in large areas subjected to pore pressure effects. This numerical approach, numerical limit analysis, utilizes the finite element method and mathematical programming techniques. Mathematical programming is needed because the basic plasticity theorems for limit analysis can be cast as optimization problems. The generated optimization problem is formulated under a second-order cone programming framework, which is known to solve large-scale problems with great computational efficiency. The main objective of this work was to determine the slope safety factor and the collapse mechanism of soils governed by the Drucker–Prager yield criterion for large-scale 3D problems including pore pressure effects. This approach is applied to an experimental catchment in the Oregon Coast Range that failed after an intense rainfall. The results were compared with a previous stability analysis of the area available in the literature that used a novel 3D limit equilibrium method.

An improved artificial immune system for seeking the Pareto front of land-use allocation problem in large areas

The Pareto front can provide valuable information on land-use planning decision by revealing the possible trade-offs among multiple, conflicting objectives. However, seeking the Pareto front of land-use allocation is much more difficult than finding a unique optimal solution, especially when dealing with large-area regions. This article proposes an improved artificial immune system for multi-objective land-use allocation (AIS-MOLA) to tackle this challenging task. The proposed AIS is equipped with three modified operators, namely (1) a heuristic hypermutation based on compromise programming, (2) a non-dominated neighbour-based proportional cloning and (3) a novel crossover operator that preserves connected patches. To validate the proposed algorithm, it was applied in a hypothetical land-use allocation problem. Compared with the Pareto Simulated Annealing (PSA) method, AIS-MOLA can generate solutions more approximate to the Pareto front, with computation time amounting to only 5.1% of PSA. In addition, AIS-MOLA was also applied in the case study of Panyu, Guangdong, PR China, a large area with cells. Experimental results indicate that this algorithm, even dealing with large-area land-use allocation problems, is capable of generating optimal alternative solutions approximate to the true Pareto front. Moreover, the distribution of these solutions can quantitatively demonstrate the complex trade-offs between the spatial suitability and the compactness in the study area. Software and supplementary materials are available at http://www.geosimulation.cn/AIS-MOLA/.

Chlorophyll stability index (CSI): its impact on salt tolerance in rice

Salinity is a major constraint to successful agriculture in the arid and semiarid tropics. High-yielding varieties do not perform well under salt stress conditions. Thus, there is a need to develop special varieties that can perform well under saline conditions. The area with potential saline soil is about 20 million ha, and about 7 million ha are severely affected by salinity. This constitutes a major part of problem soils in India. Irregular monsoon and irrigation in red soil cause salinity problems in large areas. The chlorophyll stability index (CSI) is an indication of the stress tolerance capacity of plants. A high CSI value means that the stress did not have much effect on chlorophyll content of plants. A higher CSI helps plants to withstand stress through better availability of chlorophyll. This leads to increased photosynthetic rate, more dry matter production, and higher productivity. This indicates how well chlorophyll can perform under stress.

95/05202 Solving heating and cooling problems in large areas

95/05202 Solving heating and cooling problems in large areas

An evaluation of strategic and threshold control measures against the Karoo paralysis tick, Ixodes rubicundus (Acari: Ixodidae) in South Africa.

Paralysis caused by feeding female Ixodes rubicundus ticks is a major problem in large areas of South Africa. As the life cycle of the tick extends over a period of 2 years, it was hypothesized that strategic treatment of sheep with an acaricide over a 2 year period, timed to kill most engorging females, should markedly lower the biotic potential of the tick. Two flocks of sheep grazing in separate paddocks known to be infested with I. rubicundus were treated either strategically or on a threshold basis (i.e. only when tick challenge exceeded a predetermined critical level in terms of paralysis) for a 2 year period. The tick burdens of untreated control sheep running with the two flocks were monitored over a 4 year period and their seasonal dynamics determined. The times at which peak infestations occurred were similar for both flocks of sheep, but significant differences in mean tick burdens between the two flocks were recorded. Tick numbers on sheep in the strategically treated flock did not decrease during the third and fourth years of the trial as was expected. Possible reasons for this were low stocking densities, especially during times of peak abundance of adults and the presence of wild hosts which maintained tick populations.

Clinical application of mefloquine pharmacokinetics in the treatment of P falciparum malaria.

Malaria remains a major public health problem in large areas of the world. One of the major factors responsible for the resurgence is the emergence of Plasmodium falciparum, resistant to available antimalarials. An antimalarial, mefloquine, has been considered since its introduction as a promising alternative antimalarial drug to overcome the situation of widespread multidrug resistant P falciparum. Pharmacokinetic studies of mefloquine have been investigated in several groups of subjects either as mefloquine alone or as combined regimens. The oral absorption of mefloquine is relatively rapid, reaching peak concentrations within 24 hours. Metabolism takes place in the liver, with carboxymefloquine as a major metabolite. Mefloquine has a large apparent volume of distribution of 200 L and is highly bound (98%) to plasma proteins. The elimination is slow; the terminal half-life is 13 10 to 14 days in Thai patients with falciparum malaria. Vomiting within 1 hour of drug administration has an influence on blood concentrations of mefloquine and this may result in treatment failure. The whole blood concentrations of mefloquine on the first two days of treatment are important determinants of parasitological response. There appear to be no pharmacokinetic interactions between mefloquine and the other two components of Fansimef in patients with uncomplicated falciparum malaria. The advantage of this combination over mefloquine alone in multidrug resistant P falciparum is still debatable. However, recent data seem to support the higher efficacy of Fansimef over mefloquine alone. Concurrent administration of antibiotics, ie ampicillin and tetracycline with mefloquine results in a significant increase in maximum concentration, reduction of the apparent volume of distribution and shortening of the terminal elimination half-life of mefloquine. An antiemetic drug metoclopramide accelerates the absorption of mefloquine and increases the maximum concentration. In contrast, mefloquine concentrations are decreased in the presence of an antimalarial, artesunate. Primaquine has no effect on the pharmacokinetics of mefloquine when given concurrently.

Soil fertility problems — an agriculture and forestry perspective

The loss of soil fertility is an important problem in large areas that have been utilised for agricultural production during the last 20 years. Enhanced concentration, intensification and specialisation of crop and livestock production without sufficient consideration of the natural site specific soil and climate conditions caused pronounced degradation and partly irreversible damage of the soil including such processes as soil compaction, water and wind erosion, water logging, chemical degradation and humus loss. With regard to Germany the sandy and loamy to sandy soils in the northern part of the country are more impacted than the naturally loamy soils in southern Germany. Clearly, damaged soils cannot accomplish their ecological ‘tasks’ (e.g. buffer, filter, storage function) in the various ecosystems of the landscape. In addition, man's activity particularly in highly industrialized nations brought about severe problems with regard to forest ecosystem health. For example, in Germany and elsewhere new types of forest decline are occurring since the mid 1970s. This damage is related to air pollution and other factors. Despite much controversy there exists no doubt that air pollution stresses like ‘acid rain‘ and enhanced N deposition affect forest soils by e.g. accelerating soil acidification. This process increases the loss of cationic nutrients such as Mg, Ca and K from the ecosystem. Therefore it is not surprising that various types of this new damage involve Mg and K deficiencies. In this context fertilizer and lime applications have proven useful mitigation tools. However, when these practices are conducted improperly, i.e. not related to site and stand conditions, ecological hazards may arise. It is therefore necessary to develop new solutions to restore soil fertility and to improve soil protection in agricultural and forest ecosystems.

マラリアワクチンの構造化学的研究

Malaria still remains a serious health problem in large areas of the world, and in this article, recent research progress mainly made by us toward malaria vaccine development has been reviewed. 1) Peptide vaccines (antigens) of immunodominant tetrapeptide repeats (NANP and NVDP) of the circumsporozoite surface protein of the malaria parasite, Plasmodium falciparum, were genetically produced in E. coli as a fusion protein with a part of human growth hormone, which has affected on the conformations and immunogenicities of the peptide vaccines. 2) Monoclonal antibodies against the peptide antigens were produced by fusion of mouse spleen cells with myeloma cells, and the F (ab's) obtained by partial digestion of the antibodies with papain were used for the measurement of the dissociation constants of the antigen-antibody complexes. The amino acid sequence of the Hv region in F(ab) domain was also deduced from its nucleotide sequence.

Background evaluation and spot recognition on crystallographic diffraction photographs

A computer method is described which provides a means for determination of both background and spot characteristics without the knowledge a priori of the positions of those spots in a crystallographic diffraction photograph. The background is first determined in any arbitrary region by means of a histogram technique. Then the sets of points emerging from the background's statistical tolerances are collected together with simple neighbouring rules. The problem of large areas which do not fit in a computer memory is discussed and solved with an overlapping window technique. The accuracy of the method is checked by means of a simulation (characteristic retrieval of computer generated spots); the precision appears to be better than the classical rectangular box method except for weak spots.