Dissipation of the defoliant tribufos in cotton-producing soils

Soil dissipation of the cotton defoliant tribufos was measured in laboratory incubations and on 0.2-ha research plots. Computed 50% dissipation time (DT(50)) using nonlinear and linear kinetic models ranged from 1 to 19 days. Data indicated that exchangeable soil aluminum inhibited tribufos-degrading soil organisms. Nevertheless, measured DT(50) values were 40 to 700 times less than the aerobic soil half-life (t(1/2)) values used in recent tribufos risk assessments. DT(50) values suggest that risk estimates were overstated. However, edge-of-field runoff concentrations measured on research plots exceeded invertebrate LOECs, thus some aquatic risk is indicated. Field data also suggested that volatilization may be a significant soil dissipation pathway. From this result, we conclude that volatilization should be included in simulation models used for pesticide registration. This will likely improve the accuracy of model outputs for products such as tribufos. Potential volatilization losses indicate a need to evaluate the atmospheric behavior of tribufos.     

Penetration of human-induced warming into the world's oceans

A warming signal has penetrated into the world's oceans over the past 40 years. The signal is complex, with a vertical structure that varies widely by ocean; it cannot be explained by natural internal climate variability or solar and volcanic forcing, but is well simulated by two anthropogenically forced climate models. We conclude that it is of human origin, a conclusion robust to observational sampling and model differences. Changes in advection combine with surface forcing to give the overall warming pattern. The implications of this study suggest that society needs to seriously consider model predictions of future climate change.     

HCV persistence and immune evasion in the absence of memory T cell help

Spontaneous resolution of hepatitis C virus (HCV) infection in humans usually affords long-term immunity to persistent viremia and associated liver diseases. Here, we report that memory CD4+ Tcells are essential for this protection. Antibody-mediated depletion of CD4+ Tcells before reinfection of two immune chimpanzees resulted in persistent, low-level viremia despite functional intra-hepatic memory CD8+ Tcell responses. Incomplete control of HCV replication by memory CD8+ Tcells in the absence of adequate CD4+ Tcell help was associated with emergence of viral escape mutations in class I major histocompatibility complex-restricted epitopes and failure to resolve HCV infection.     

Recording and interpretation of cerebral magnetic fields

Contemporary brain research progresses along two main lines: the microlevel approach explores single neurons and subcellular elements, while macrolevel studies focus on more complex cerebral functions, including behavior. This review presents results obtained mainly in our laboratory by means of an intermediate method, magnetoencephalography (MEG), which reflects cortical activity of neuronal populations at the level fo cytoarchitectonic areas. Because it is completely noninvasive, MEG can be used to study brain functions that are characteristically human.     

Effect of blue-green algae on aggregate stability and rice yield under different irrigation and nitrogen levels

The application of blue-green algae improved the aggregation status of rice field soils under different levels of irrigation and nitrogen fertilizer (urea) and increased the grain yield of rice significantly.     

Sterol Ring System Oxidation Pattern in Marine Sponges

The marine sponges (Porifera) are a unique group of sedentary organisms from which several novel natural products are reported, many of which have useful biological activities. In producing unusual sterols, they occupy a preeminent position among the various groups of organisms. The polar sterols of sponges reported as at the end of the year 2002 number about 250; their ring structure changing a hundred times. The oxidation pattern in the sterol ring system, from the point of view of biogenesis seems to be mainly of four types. Each sponge species is able to produce sterols fitting into one of the four main biogenetic pathways viz., (i) 3β-hydroxy-Δ⁵-sterol pathway, (ii) 3β-hydroxy-Δ⁷-sterol pathway, (iii) 3β-hydroxy-Δ^5,7-sterol pathway, and (iv) 3α-hydroxy sterol pathway.     

Cellulase activity in rohu fingerlings

The activity of cellulase was determined in the intestine of rohu, Labeo rohita, fingerlings fed on separate dietary formulations incorporating Leucaena leaf meal and synthetic cellulose at 20% level in proportional replacement of the ingredients from the fish-meal-based reference diet. Three more replicate experimental diets were prepared by incorporating 1% tetra-cycline, a broad-spectrum antibiotic, into the former three dietary formulations so as to circumvent the action of microflora in digestive function. Cellulase activity was found to be highest in fish fed on the cellulose incorporated diet, followed by those maintained on the plant-protein-based and reference diets, respectively. A diet-dependent variation in cellulase activity was apparent. However, a sharp decline in the level of cellulase activity was observed in the fish fed diets containing tetracycline, which is supposed to have destroyed all the gut microflora. The microbial culture of intestinal and hepatopancreatic extracts also confirmed the absence of microflora in the fish fed tetracycline-compounded diets. The study indicates that cellulase activity in rohu is largely contributed by the intestinal microflora, while the reduced activity recorded in the fish reared on antibiotic-compounded diets may be due to the presence of some other source of cellulase secretion apart from cellulolytic microbial action. The information generated from the present investigation might contribute towards better feed formulation for carp at low cost, incorporating plant-based feed ingredients. © Rapid Science Ltd. 1998     

Impact of community forest program in protection forest on livelihood outcomes: A case study of Lampung Province,Indonesia

The global to local-level importance of Indonesian forests for the environment and development is now very well documented. However, how to govern these forests to achieve the diverse and, at times, conflicting interests is still an open question. Hutan Kemasyarakatan (HKm) is a community forest (CF) that is being implemented to contribute to local development while creating sufficient incentives for conserving the forest. Previous studies have demonstrated the potential of HKm to conserve forests. This study analyzed the changes in the five major types of capital for HKm farmers. The results indicated HKm to have contributed positively to the improvement of natural, physical, and human capital. In addition to its direct impact, HKm was also found to improve the financial capital of the farmers by avoiding patron–client relationships and side payments between the pre-HKm illegal encroacher farmers (now legal land cultivators) and government officers. Although the results support the possibility of HKm producing a win-win situation between forest conservation and rural development, its future applicability, especially with consideration of population growth and associated increase in demand for cultivation land, needs to be given due emphasis.