The Remarkable Beneficial Effect of Adding Oral Simvastatin to Topical Betamethasone for Treatment of Psoriasis: A Double-blind, Randomized, Placebo-controlled Study

Psoriasis is a common chronic inflammatory disease with unpredictableprognosis. Given the immunomodulatory effects of statins, the present study was conducted to determine whether the addition of orally administered simvastatin to the topical betamethasone, a standard antipsoriatic treatment, can produce a more powerful therapeutic response against this clinical conundrum.In a double-blind study, 30 patients with plaque type psoriasis were randomly divided into two equal treatment groups. Group 1 received oralsimvastatin (40 mg/d) plus topical steroid (50% betamethasone in petrolatum) for 8 weeks and group 2 received oral placebo plus the same topical steroid for the same time period. Psoriasis Area and Severity Index (PASI) score was checked before and at the end of the treatment period.PASI score decreased significantly in both groups, but the decline of PASI score was more significant in patients who received simvastatin(Mann-Whitney test; P-value=0.001). No side effect or any laboratory abnormality was detected in patients.Our work, which is the first doubleblind, randomized, placebo-controlled study on this subject, shows that oral simvastatin enhances the therapeutic effect of topical steroids against psoriasis. The increased risk of cardiovascular accidents in psoriatic patients and the protective effect of statins against cardiovascular disease further encourages their use in the treatment of this clinical conundrum.Keywords: Simvastatin – Psoriasis – Treatment – Topical Steroid

Experimental analysis of subsurface heating and irrigation on the temperature and water content of soils

Multiple use of waste heat from power plants may become an important consideration in the development, siting, and certification of these plants. A multiple use system of components that can beneficially utilize waste heat may include home heating and cooling, greenhouses, animal enclosures, open basins for single cell protein production and fish farming, and open field soil warming. A subsurface irrigation-soil warming system utilizing waste heat was analyzed in this study. Thermal power plant condenser cooling water pumped through buried porous pipes was considered as a heat and water source for soil heating and subsurface irrigation. Energy is transferred from the heat source to the surrounding soil, warming it above its natural temperature. In addition, water seeping from the porous pipe prevents drying around the heat source and supplies the plant roots throughout the soil profile while avoiding the large evaporation losses at the soil surface associated with surface irrigation methods. Experiments were conducted in the laboratory to study this system. Soil was packed in containers 48 cm deep, 40 cm wide, and 4 cm thick. A heat source consisting of a copper covered electrical resistance wire was placed against one side of the box at a depth of 32 cm. A water source consisting of a porous tube was placed 2 cm above the heat source. The contained soil slab thus represented a subsurface soil warming and irrigation system with heat and water sources at depths of 32 and 30 cm respectively and a 77 cm spacing. A series of experiments was conducted with heat source temperatures of 29, 36, and 44 C, and surface heat load cycles with maxima of 0, 13, 52, and 117 watts. These experiments were repeated for Quincy, Cloquato, and Chehalis soils. The box filled with soil was saturated with water and then drained. Experiments were initiated by energizing the heat source. Temperature distributions throughout the soil profile and rates of energy dissipation were measured. Water application rates required to maintain a constant soil water content were obtained. In each experiment, water was applied at such a rate that the water content at a point near the heat source, monitored with a gamma ray attenuation system, remained constant. Apparent thermal conductivities of Quincy, Cloquato, and Chehalis soils as a function of water content were measured at 25 and 45 C by the heat probe method. The soil apparent thermal conductivity was also computed from a theoretical model based on its mineral composition, porosity, water content, and the thermal conductivity of the individual components. This model takes into account the vapor flow contribution to the apparent thermal conductivity in wet soils. Its magnitude depends on the available air-filled pore space, total porosity, and the free energy of the retained water. Predicted and experimental values of thermal conductivities showed good agreement. Soil temperature distributions were calculated using theoretical models presented in the literature. Predicted and measured isotherms showed good agreement. Energy dissipation rates as a function of soil thermal conductivity, temperature differences between heat source and soil surface, and depth and spacing of heat source were obtained. They were in agreement with those calculated from theoretical considerations. The total land area required to dissipate the waste energy from a 1000 MWe power plant operating with 34 percent efficiency was calculated for each of the three soils used in the experiments. It was found that 2841, 3714, and 4390 hectare would be required for Quincy, Cloquato, and Chehalis soils respectively. Quincy soil would require the smallest land area for this purpose because of its higher thermal conductivity. Economical and technical considerations for the installation of subsurface heating and irrigation systems require flat land close to the electrical power plant. Large areas of flat land are not always present. Subsurface irrigation replenished water lost by surface evaporation. Water use rates were obtained as a function of temperature differences between heat source and soil surface, soil type, and a range of surface heat loads. The water application rates ranged from 1.50 mm/day for Chehalis soil with a heat source temperature of 29 C in combination with the lowest surface heat load to 6.0 mm/day for Quincy soil with a heat source temperature of 44 C in combination with the highest surface heat load. These rates were adequate to prevent drying around the heat sources and supply the water needs of an actively growing crop. The effective use of this system depends on the development of suitable tubing to conduct and discharge water which could be used without clogging of the pores through which water seeps into the ground. The proposed soil warming and irrigation system does not appear to be an attractive alternative power plant cooling system. The system holds promise however as an economically attractive management system for the production of high value crops

Nitrogen uptake by wheat (Triticum aestivum VILL., Host) as a function of root temperature and plant water stress

The effect of soil temperature and plant water stress on nitrogen uptake, growth rate and transpiration rate of wheat (Triticum aestivum VILL. , Host) seedlings was studied. A special apparatus for the control of plant water stress and root temperature was used. Leaf area was measured by the air flow planimeter technique. Dry matter weight was determined with a Mettler balance after oven drying of the plant material. Nitrogen concentration in shoots and roots was determined by the micro-Kjeldahl procedure. The transpiration rate was obtained with a constant-water level graduated burette device operating on the principle of a Mariotte bottle. Growth rate of shoots and roots was slowest at the extreme temperatures with a maximum rate of growth occurring around a root temperature of 24° C. The growth rate was higher at a plant water stress of 0.35 bar than at a plant water stress of 2.5 bars. Rates of transpiration decreased steadily with increasing plant water stress. The increase of transpiration rate with root temperature increase was attributed to the change of water viscosity and increased root cell membrane permeability. The nitrogen content of roots and shoots increased as root temperatures increased from 10.0 to 25.0°C, while there was no significant difference at plant water stresses of 0.35 and 2.5 bars. The increase in rate of nitrogen uptake was found to be proportional to the increase in rate of root growth. The same proportionality described a decrease in the rate of nitrogen uptake as a result of decreased rate of root growth. The rate of leaf area increase was found to be related to the rate of dry matter increase of the shoot. This relation was the same at all root temperatures and plant water stresses considered

A review on partial root-zone drying irrigation.

Abstract Available fresh water resources are subjected to an ever-increasing pressure due to extensive agricultural water demand for irrigated lands. A long-term perspective in shortage of fresh water resources, especially in arid and semi-arid area, highlights an urgent solution for innovative irrigation strategy and agricultural water management. This paper is a review on the wide applications of the partial root-zone drying irrigation (PRD) on diverse plant species. The PRD irrigation is a novel improvement of deficit irrigation in which half of the root zone is irrigated alternatively in scheduled irrigation events. In the last decade, scientists across the world, especially from arid to semi-arid countries, have extensively evaluated this irrigation as a water-saving irrigation strategy on agronomic and horticultural plants. This review paper focuses on the physiological and morphological aspects of PRD on plants and its ultimate impact on yield and water productivity. Overall, under limited water resources where water is precious, PRD is a viable irrigation option to increase water productivity while marinating the yield, rather than only increasing the economic yield without concerning the value of water in limited water environments

Effect of Water Potential on Germination of Verticillum dahliae microsclerotia

The effects of osmotic and matric potentials on the microsclerotial germination of Verticillium dahliae was examined at room temperature in 1% water agar amended with sodium chloride and polyethylene glycole. Treatments consisted of 6 levels of osmotic and matric potentials (0, -0.3, -0.6, -0.9, -1.2, and -1.5 MPa) laid out as factorial arrangement in a completely randomized design. Decreasing matric potential reduced germination, whereas the osmotic potential increased germination up to -0.6 MPa but any further increase caused it to decline. It was concluded that the matric potential is a more limiting factor than the osmotic potential for the germination of V. dahliae microsclerotia

Supplemental irrigation management of rainfed grapevines under drought conditions using the CropSyst model

Aim of study: To determine how much water should be used and when it should be applied in rain-fed grapevine using a cropping system simulation model (CropSyst), and also the economic analysis of supplemental irrigation for rainfed grapevine.Area of study: This study was conducted at the School of Agriculture, Shiraz University, Shiraz, Iran, in 2012, 2013 and 2014.Material and methods: The CropSyst model was calibrated to predict the rainfed yields of ‘Askari’ and ‘Yaghooti’ grapevines in different climates using four amounts of SI: 250 L (I1), 500 L (I2), 1000 L (I3) and 0 (I4), five SI times: single in March (T1), single in April (T2), single in March + single in April (T3), single in May (T4) and single in June (T5).Main results: Treatment T3 increased the average simulated yield of ‘Askari’ by 15% to 40% at regions with P/ETo>0.6, 17% to 61% at 0.2<P/ETO<0.6, and 26% to 61% at P/ETO<0.2, while in ‘Yaghooti’ it increased about 2% to 41% at regions with P/ETo>0.6, 4% to 36% at 0.2<P/ETO<0.6 and 2% to 26% at P/ETO<0.2. By increasing the water price by 30% and 50%, net benefits for the ‘Askari’ decreased by about 31% and 54%, while 6% and 18%, for ‘Yaghooti’ respectively.Research highlights: The CropSyst model can successfully predict soil water content and grapevine yields. Application of SI in May increased significantly the grapevine yield as compared to other SI times

Estimating the furrow infiltration characteristic from a single advance point

Management and control of surface irrigation, in particular furrow irrigation, is limited by spatio-temporal soil infiltration variability as well as the high cost and time associated with collecting intensive field data for estimation of the infiltration characteristics. Recent work has proposed scaling the commonly used infiltration function by using a model infiltration curve and a single advance point for every other furrow in an irrigation event. Scaling factors were calculated for a series of furrows at two sites and at four points down the length of the field (0.25 L, 0.5 L, 0.75 L and L). Differences in the value of the scaling factor with distance were found to be a function of the shape of the advance curves. It is concluded that use of points early in the advance results in a substantial loss of accuracy and should be avoided. The scaling factor was also strongly correlated with the furrow-wetted perimeter suggesting that the scaling is an appropriate way of both predicting and accommodating the effect of the hydraulic variability

Estimativa da área foliar do pepino em ambiente protegido por medidas lineares sob salinidade e enxertia

The measurement of leaf area by linear parameters is a useful tool when plants cannot be destroyed for direct measurement. The objectives of this study were to establish equations to estimate the leaf area of greenhouse-cucumber and to evaluate the effects of salinity and grafting on this estimative. Non-grafted cucumber seedlings, cv. 'Hokushin', were transplanted in a greenhouse and were irrigated with water of different salinities (1.0, 3.2 and 5.0 dS m-1). In the second growing period, the same cultivar was grafted on Cucurbita spp. and the plants were irrigated with water of 1.4, 3.0 and 5.3 dS m-1. Leaves of different sizes were collected from both experiments and leaf area was determined by an integrating area meter. Leaf length (L) and width (W) were also recorded. An equation for estimating the leaf area from L and W was developed for a given salinity level or grafting condition and estimated well the area of leaves collected in the other treatments. The leaf area (LA) of cucumber 'Hokushin' could be estimated using the equation LA = 0.88LW - 4.27, for any grafting and salinity conditions.A determinação da área foliar por medidas lineares é uma ferramenta útil quando as plantas não podem ser destruídas para que a medição direta seja realizada. Os objetivos desse trabalho foram definir equações para a estimativa da área foliar do pepino em ambiente protegido e avaliar os efeitos da salinidade e da a enxertia nessa estimativa. Mudas de pepino, cv. 'Hokushin', não enxertadas, foram transplantadas em um ambiente protegido e irrigadas com água de diferentes salinidades (1,0, 3,2 e 5,0 dS m-1). No segundo período de cultivo, a mesma cultivar foi enxertada sobre Cucurbita spp., sendo as plantas irrigadas com água de 1,4, 3,0 e 5,3 dS m-1. Foram coletadas folhas de diferentes tamanhos dos dois cultivos e dos três tratamentos e a área foliar foi determinada por um medidor de área foliar. O comprimento (C) e a largura (L) da folha também foram registrados. Desenvolveram-se equações pelas quais a área foliar pôde ser estimada a partir de medidas de C e L. A equação desenvolvida para um dado nível de salinidade ou condição de enxertia estimou bem a área das folhas coletadas nos demais tratamentos. A área foliar (AF) do pepino 'Hokushin' pode ser estimada pela função AF = 0,88CL - 4,27, para qualquer condição de enxertia e salinidade

Interaction of different irrigation strategies and soil textures on the nitrogen uptake of field grown potatoes.

Abstract Nitrogen (N) uptake (kg ha -1 ) of field-grown potatoes was measured in 4.32 m 2 lysimeters that were filled with coarse sand, loamy sand, and sandy loam and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments received 65% of FI after tuber bulking and lasted for six weeks until final harvest. Results showed that the irrigation treatments were not significantly different in terms of N uptake in the tubers, shoot, and whole crop. However, there was a statistical difference between the soil textures where plants in the loamy sand had the highest amount of N uptake. The interaction between irrigation treatments and soil textures was significant, and implied that under non-limiting water conditions, loamy sand is the suitable soil for potato production because plants can take up sufficient amounts of N and it could potentially lead to higher yield. However, under limited water conditions and applying water-saving irrigation strategies, sandy loam and coarse sand are better growth media because N is more available for the potatoes. The simple yield prediction model was developed that could explains ca. 96% of the variations of fresh tuber yield based on the plant evapotranspiration (ET) and N uptake in the tuber or whole crop