Determination of growth-stage-specific crop coefficients (Kc) of cotton and wheat

Development of crop coefficient (Kc), the ratio of crop evapotranspiration (ETc) to reference evapotranspiration (ETo), can enhance ETc estimates in relation to specific crop phenological development. This research was conducted to determine growth-stage-specific Kc and crop water use for cotton (Gossypium hirsutum) and wheat (Triticum aestivum) at the Texas AgriLife Research field at Uvalde, TX, USA from 2005 to 2008. Weighing lysimeters were used to measure crop water use and local weather data were used to determine the reference evapotranspiration (ETo). Seven lysimeters, weighing about 14 Mg, consisted of undisturbed 1.5 m × 2.0 m × 2.2 m deep soil monoliths. Six lysimeters were located in the center of a 1-ha field beneath a linear-move sprinkler system equipped with low energy precision application (LEPA) and a seventh lysimeter was established to measure reference grass ETo. Crop water requirements, Kc determination, and comparison to existing FAO Kc values were determined over a 2-year period on cotton and a 3-year period on wheat. Seasonal total amounts of crop water use ranged from 689 to 830 mm for cotton and from 483 to 505 mm for wheat. The Kc values determined over the growing seasons varied from 0.2 to 1.5 for cotton and 0.1 to 1.7 for wheat. Some of the values corresponded and some did not correspond to those from FAO-56 and from the Texas High Plains and elsewhere in other states. We assume that the development of regionally based and growth-stage-specific Kc helps in irrigation management and provides precise water applications for this region.     

Schisandrin B protects against solar irradiation-induced oxidative injury in BJ human fibroblasts

The effects of schisandrin B (Sch B) and its analogs on solar irradiation-induced oxidative injury were examined in BJ human fibroblasts. Sch B and schisandrin C (Sch C) increased cellular reduced glutathione (GSH) level and protected against solar irradiation-induced oxidative injury. The photoprotection was paralleled by decreases in the elastases-type protease activity and matrix-metalloproteinases-1 expression in solar-irradiated fibroblasts. The cytochrome P-450-mediated metabolism of Sch B or Sch C caused ROS production. The results suggest that by virtue of its pro-oxidant action and the subsequent glutathione antioxidant response, Sch B or Sch C may offer the prospect of preventing skin photo-aging.     

A study on construction costs per unit area of irrigation projects

The cost constructing for irrigation is often given in $/ha. In deciding whether a project is worth undertaking, it is important to weigh the anticipated benefits against the expected costs. In this study, unit area construction costs based on the way of project water supply (gravity, pump) and scheme type (classic canal, flume, pipe) were calculated for the 211 irrigation projects operated and constructed by DSI (State Hydraulic Works) in Turkey. In a case study of the 27 irrigation schemes constructed by DSI in the Büyük Menderes and West Mediterranean basins, construction costs per unit area, irrigation ratio, and amount of unproductive costs were determined. As a result, though the area of 76383 ha was constructed for irrigation schemes, this area wasn??t under irrigation services with several various reasons; therefore, 641 million $US according to water supply way, and 574 million $US to the scheme type were unproductive investment for irrigation projects researched in the basins.     

Oxygen isotopic compositions of asteroidal materials returned from Itokawa by the Hayabusa mission

Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid.     

Characteristics of soil microbiostasis

No increase in numbers of fungi, actinomycetes and bacteria in 3 days, as measured by selective media, was used as an indication of the presence of fungistasis, actinostasis and bacteriostasis in soil, respectively. The population of fungi, actinomycetes and bacteria did not increase in 9 of 10 soils tested indicating concurrent existence of fungistasis, actinostasis and bacteriostasis in a wide range of soils. When Penicillium funiculosum, Streptomyces scabies and Agrobacterium radiobacter were used as test organisms, these three types of microbiostasis were detected simultaneously in all 8 soils tested. All three groups of microorganisms flourished in autoclaved soil, and microbiostasis was restored to sterilized soil by reinoculation with 1% natural soil or microorganisms including antibiotic and non-antibiotic producers. Soil microbiostasis was annulled completely or partially by addition of different nutrie0nts. Bacteriostasis appeared to be the easiest to overcome with nutrients among these three types of microbiostasis.     

Propagule size: Its relation to population density of microorganisms in soil

Analysis of published data on occurrence of bacteria and fungi in soil revealed an inverse linear relationship between the logarithm of propagule size and the logarithm of population density among these microorganisms. The regression equation Y= 8.841? 0.540.X (in which Y is log numbers of propagules kg^?1 of soil and X is log volumes per 100 propagules), describing the relationship between propagule size and maximum population density of microorganisms in soil, afforded the predicted values of the population density very close to the reported values. The regression equation may also be used for predicting the possible propagule type of a microorganism in soil, if its population density is known.     

Hypolipidemic effect of glycosaminoglycans from the sea cucumber Metriatyla scabra in rats fed a cholesterol-supplemented diet

The purpose of this study was to determine the hypolipidemic effects of the glycosaminoglycans (GAGs) extracted from a sea cucumber, Metriatyla scabra. Using DEAE column chromatography, two major peaks containing GAGs were obtained: peak 1 (P-1) contained mainly GAGs (as hexuronic acid and hexosamine), whereas P-2 contained mostly free glycan (as fucose) with little hexuronic acid or hexosamine. Therefore, we used only the P-1 fraction (with molecular weights in the range 200-500 kDa) for evaluation of hypolipidemic effects. The lyophilized GAGs were administered orally to male Wistar rats at 5, 10, 20, and 50 mg/kg body weight for six consecutive weeks, during which the rats were fed ad libitum a basal laboratory diet with or without 1% cholesterol. The results show that the 1% cholesterol diet significantly increased plasma total cholesterol, LDL-cholesterol, and atherogenic index. Cholesterol supplementation also significantly increased hepatic TG, cholesterol, phospholipid, and liver weight. When rats fed the 1% cholesterol diet were supplemented orally with the sea cucumber GAGs, plasma levels of total cholesterol, LDL-cholesterol, and atherogenic index were significantly decreased, while HDL-cholesterol was significantly increased, although these effects of the GAGs were only dose-dependent at doses lower than 20 mg/kg b.w. Similarly, the GAGs significantly prevented the increase (p < 0.05) in hepatic contents of triglyceride, cholesterol, and phospholipid. Thus, the present study demonstrates that the sea cucumber GAGs have the potential of being used for reducing the risk of atherosclerosis and hyperlipoproteinemia.