Phosphatase activity in earthworm faeces

Wormcasts of Allolobophora caliginosa have been shown to have higher phosphatase activity than occurs in uningested soil, resulting in an increase in inorganic P released by mineralization of organic P. This paper describes similar observations on organic wastes which may be used for vermiculture. Besides A. caliginosa, three species which will feed on dung or other organic substrates were investigated, Eisenia foetida, Dendrobaena veneta and Lumbricus rubellus. When cow dung was used as a substrate, background phosphatase activity was too high for the effects of earthworm activity to be detected and a culture medium was therefore developed from sterilized paper waste sludge with added phytin. Phosphatase activity, assayed by a modified Hoffman method, was higher in the presence of all four earthworm species than in controls. It showed two peaks in relation to pH, at 3–5 and 9–10. The former is attributed to microbial activity and the latter to microbial activity or earthworm alkaline phosphatase. After 1 month, cultures of paper waste sludge with phytin contained about twice as much water soluble P when worms were present than in their absence.     

Use of adsorbent and supercritical carbon dioxide to concentrate flavor compounds from orange oil.

Orange oil is composed largely of terpene hydrocarbons but is a source of flavor and fragrance compounds (oxygenated) that are present in low concentrations. To increase the ratio of oxygenated compounds to terpene hydrocarbons, orange oil was partially fractionated by adsorption of the oxygenated compounds onto porous silica gel, with full utilization of its adsorbent capacity, and then further purified by desorption into supercritical carbon dioxide. The desorption of 24 compounds was monitored by GC and GC-MS. Adsorption alone removed three-fourths of the terpene hydrocarbons, and fractional extraction by supercritical carbon dioxide (SC-CO(2)) improved the separation further. Response surface methodology was used in the experimental design, and regression analysis was used to determine the effects of process variables. Extraction at low temperatures and flow rates improved separation by SC-CO(2). Decanal was concentrated to 20 times that of the feed oil by using SC-CO(2) at 13.1 MPa, 35 degrees C, and 2 kg/h. The systems were operating at close to equilibrium conditions because of the fine dispersal of the oils and the excellent mass transfer properties of supercritical carbon dioxide.     

Degradation of lignin in wheat straw during growth of the oyster mushroom (Pleurotus ostreatus) using off-line thermochemolysis with tetramethylammonium hydroxide and solid-state (13)C NMR.

The oyster mushroom (Pleurotus ostreatus) is widely cultivated on wheat straw (Triticum aestivum); however, there is a need to better understand the relationship between the chemical composition of the compost and mushroom growth. Wheat straw was degraded over a period of 63 days by P. ostreatus during which time it was sampled at weekly intervals. Off-line thermochemolysis with tetramethylammonium hydroxide and solid-state (13)C NMR were then used in the molecular characterization of the undegraded wheat straw and the degraded samples. The degraded wheat straw samples had a lower proportion of syringyl- to guaiacyl-derived moieties and cinnamyl- to guaiacyl-derived moieties than the undegraded control. There were increases in both guaiacyl and syringyl acid to aldehyde ratios with composting time, which showed that side-chain oxidation has been mediated by P. ostreatus. The (13)C NMR spectra confirmed the increase in carboxyl content but indicated that the overall lignin and methoxyl contents remained relatively constant, although some nonsystematic variations were observed. The spectra also showed a decrease in amorphous noncellulosic polysaccharides in relation to the crystalline cellulose upon degradation.     

Factors affecting the caffeine and polyphenol contents of black and green tea infusions.

The effects of product and preparation variables on the in-cup chemical composition of tea extracts is of interest because the appearance and taste characteristics and the possible health effects of a tea liquor arise from the chemical components extracted from the leaf during tea preparation. A comprehensive study was therefore undertaken to determine the contributions of product and preparation variables on the total soluble solids, caffeine, and polyphenol contents of tea extracts. The results of this study show that the variety, growing environment, manufacturing conditions, and grade (particle size) of the tea leaves each influence the tea leaf and final infusion compositions. In addition, the composition of the tea infusion was shown to be influenced by whether the tea was contained in a teabag and, if so, the size and material of construction of the bag. Finally, the preparation method, including the amounts of tea and water used, infusion time, and amount of agitation, was shown to be a major determinant of the component concentrations of tea beverages as consumed. An illustration of the variation introduced by these product and preparation factors is provided by comparing solids, caffeine, and polyphenol contents of green and black tea infusions when commercial products are prepared according to the instructions given on their packaging.     

Predictions of soil water and crop growth dynamics using the agroecosystem models THESEUS and OPUS

The agroecosystem models THESEUS and OPUS were tested with data obtained from three agricultural experimental field plots on sandy soils without groundwater located at the moraine landscape in East Brandenburg, Germany. At each of these plots, a separate agricultural management practice was applied. Measurements of soil water contents, pressure heads, above‐ground crop biomass, and crop yield from these three plots were compared with the corresponding simulation results of both models. The comparisons of simulated with measured outputs were analyzed using the modeling‐efficiency index IA. According to these analyses, both models simulated adequately the time courses of volumetric soil water contents and above‐ground crop biomass, but the time courses of pressure heads were predicted with a lower quality by both models. As for the pressure heads, the yields simulated with both models showed greater discrepancies in comparison with the observed ones. This indicates the need of a site‐specific parameter calibration of the crop‐growth modules, especially for that included in OPUS .     

Establishment techniques affect productivity,nutritive value and atmospheric N2 fixation of two sunn hemp cultivars

Nitrogen fertilization is a common practice for sustaining forage production in forage systems in southeastern United States. Warm-season annual legumes may be an alternative forage to warm-season perennial grasses that do not require N fertilization. Sunn hemp (Crotalaria juncea L.) is a fast-growing, warm-season annual legume native to India and Pakistan. The objective of this 2-year study was to assess the herbage accumulation (HA), atmospheric N₂ fixation (ANF) and nutritive value of sunn hemp. Treatments were the factorial arrangement of two sunn hemp cultivars (“Crescent Sun” and “Blue Leaf”), three seeding rates (17, 28 and 39 kg seed/ha) and seed inoculation (inoculated or non-inoculated seeds), distributed in a randomized complete block design with four replicates. Crescent sun had greater HA (3,218 vs. 1764 kg DM/ha) and ANF (41 vs. 25 kg N/ha). Blue leaf had greater crude protein (CP) (188 vs. 176 g/kg) and in vitro digestible organic matter (IVDOM) concentrations (564 vs. 531 g/kg) than crescent sun. Non-inoculated seed had greater CP than inoculated seed, 188 and 177 g/kg, respectively, and inoculation did not affect HA. Intermediate seeding rate (28 kg/ha) decreased HA (2002 kg DM/ha), while HA from high and low seeding rates (17 and 39 kg/ha, respectively) did not differ (2,863 and 2,615 kg DM/ha respectively). Planting non-inoculated crescent sun at 17 kg/ha seeding rate is a feasible management practice to produce sunn hemp in subtropical regions; however, inoculation should always be recommended for proper establishment.     

Effects of Different Factors on Concentration of Functional Components of Aronia and Saskatoon Berries

Plant Foods for Human Nutrition - Effects of different factors on the content of phenolics, anthocyanins, antioxidants and colour parameters in two varieties of Aronia and three varieties of...     

Forms of memory failure

Memory may fail in a variety of ways. Patients with Korsakoff's syndrome demonstrate global memory deficits similar to those seen in patients with early progressive dementia. Korsakoff's patients, however, may recall rules and principles for organizing information and can gain access to their previously acquired knowledge (semantic memory), whereas recent memory may be grossly impaired. In contrast, dementia patients may have little access to previously acquired knowledge and therefore have great difficulty in organizing and encoding ongoing events. These contrasting forms of memory failure have implications for understanding the structure and mechanisms of memory and learning, particularly the relationship between episodic and semantic memory, as well as the development of therapeutic strategies for cognitive impairments.