Assessment of a sequential extraction procedure for fractionation of soil arsenic in contaminated soils

A sequential fractionation scheme, based on a soil phosphorous fractionation, was developed to assess the chemical nature, and thus the potential bioavailability and mobility of As, at the sites. Soil As was separated into five fractions with (i) anion exchange resin, (ii) NaHCO₃, (iii) NaOH, (iv) HCl, (v) residual. Most sites contained relatively low concentrations of As in the two most labile fractions. The bulk of the contaminant As at the sites seemed to be associated with soil amorphous Fe and Al minerals and the dominant clay minerals which help in As sorption are montmorillonite and mica. Resin-extractable As in particular might provide a good index of potential As bioavailability and mobility.     

施氮对香稻某些生理效应的研究

用１个非和时稻品种Ｒａｔｎａ和３个香稻品种ＨＫＲ２２８，Ｂａｓｍａｔｉ３７０及ＣＢⅡ施氮和不施氮处理对比试验结果，施氮可使稻株光合作用，呼吸作用，植株含氮量提高。但是，施氮对光合作用的促进作用未达差异显著水平。对比非香稻品种Ｒａｔｎａ和春稻品种ＨＫＲ２２８，施氮对叶片呼吸作用促进作用前者大于后者。     

Evaluation of otoscope cone disinfection techniques and contamination level in small animal private practice

The objective of this study was to evaluate the level of bacterial contamination of otoscope cones in veterinary private practice, and to determine the most effective method of disinfection. Fifty small animal practices participated in this study, which included a detailed survey regarding otoscope cleaning, storage and usage and quantitative culture of the cleaned and stored otoscope cones. Using sterile technique, two cones from each of the 50 hospitals were swabbed and submitted for quantitative culture. Contamination was present in 29% of the samples and the following organisms were isolated: Flavobacterium brevis (10%), Pseudomonas aeruginosa (6%), Pseudomonas alcaligenes (4%), Staphylococcus intermedius (4%), Corynebacterium spp. (2%), Bacillus spp. (1%), Enterococcus faecalis (1%) Malassezia spp. (1%). There was no statistically significant difference between storage type (dry versus stored in solution) and for the instrumentation used to clean the cones (brush, cotton‐tipped applicator, both versus none). There was a statistically significant difference between the different cleaning solutions (P < 0.001) and between the storage solutions (P = 0.003). A single most effective cleaning solution was unable to be determined due to the large number of solutions utilized. Cetylcide G^® (Cetylite Industries, Inc., Pennsauken, NJ, USA) was the most effective of the three most commonly used storage solutions (Cetylcide G^®, Benz‐all^®, and 2% Chlorhexidine gluconate) when used as directed (P < 0.001). The level of contamination had a positive association with the frequency of cone use and a negative association with the frequency of storage solution replacement.     

Application of Statistical Tools for Data Analysis and Interpretation in Rice Plant Pathology

There has been a significant advancement in the application of statistical tools in plant pathology during the past four decades. These tools include multivariate analysis of disease dynamics involving principal component analysis, cluster analysis, factor analysis, pattern analysis, discriminant analysis, multivariate analysis of variance, correspondence analysis, canonical correlation analysis, redundancy analysis, genetic diversity analysis, and stability analysis, which involve in joint regression, additive main effects and multiplicative interactions, and genotype-by-environment interaction biplot analysis. The advanced statistical tools, such as non-parametric analysis of disease association, meta-analysis, Bayesian analysis, and decision theory, take an important place in analysis of disease dynamics. Disease forecasting methods by simulation models for plant diseases have a great potentiality in practical disease control strategies. Common mathematical tools such as monomolecular, exponential, logistic, Gompertz and linked differential equations take an important place in growth curve analysis of disease epidemics. The highly informative means of displaying a range of numerical data through construction of box and whisker plots has been suggested. The probable applications of recent advanced tools of linear and non-linear mixed models like the linear mixed model, generalized linear model, and generalized linear mixed models have been presented. The most recent technologies such as micro-array analysis, though cost effective, provide estimates of gene expressions for thousands of genes simultaneously and need attention by the molecular biologists. Some of these advanced tools can be well applied in different branches of rice research, including crop improvement, crop production, crop protection, social sciences as well as agricultural engineering. The rice research scientists should take advantage of these new opportunities adequately in adoption of the new highly potential advanced technologies while planning experimental designs, data collection, analysis and interpretation of their research data sets.     

Ultrastructural effects of mestranol and norethindrone on guinea pig endometrial stromal cell.

The effect of exogenous contraceptive steroids on the ultrstructural features of the endometrial stromal cells was studied in 64 guinea pigs allotted to 4 treatment groups. Four guinea pigs from each group were killed 14, 28, 56, and 84 days after treatment with mestranol (0.01 mg/day in 1 ml of oil) or with norethindrone (0.2 mg/day in 1 ml of oil) or with a combination of both (0.001 mg of mestranol/day and 0.02 mg of norethindrone/day in 1 ml of oil) or with 1 ml of vegetable oil (oil-treated controls). An additional 12 normal guinea pigs (nontreated controls) were killed during the follicular and luteal phases of the estrous cycle, and uterine specimens were immediately collected to determine base line characteristics. During estrus, the stromal cells of these 12 guinea pigs had abundant dilated rough endoplasmic reticulum. The interstitium was filled with collagen. During the luteal phase. the cytoplasm of the stromal cells of the 12 guinea pigs contained a prominent nucleus and rough endoplasmic reticulum with undilated cisterns. The interstitium contained sparse amounts of collagen. The stromal cells of the oil-treated control guinea pigs seemed similar in ultrastructure to the stromal cells of the 12 nontreated control guinea pigs at the luteal phase. Mestranol-fed guinea pigs had dilated rough endoplasmic reticulum and well-developed Golgi apparatus within 2 weeks of initial treatment. The interstitium of mestranol-treated guinea pigs had more collagen than that of the oil-treated controls and nontreated controls during the luteal phase. Prolonged treatment with mestranol caused extensive dilation of the cisternae of the endoplasmic reticulum. The interstitium was filled with abundant collagen. Pronounced alterations in the cytoplasmic organelles or extracellular connective tissue were not ovserved in guinea pigs given norethindrone alone or norethindrone in combination with mestranol for 14 days. The stromal cells closely resembled the cells of the mature animal at luteal phase. However, the dilated rough endoplasmic reticulum that occurred in cells after mestranol treatment was not seen in stromal cells after 84 days of treatment with norethindrone. Dilation of rough endoplasmic reticulum was also observed when both the contraceptive steroids were given simultaneously for 84 days. The increased and extensively dilated rough endoplasmic reticulum seen during the follicular phase and after mestranol administration or after 84 days of treatment with mestranol and norethindrone probably indicates increased protein synthesis by the endometrial stromal cells.     

Long-term effectiveness of grain protectants and structural treatments against Liposcelis decolor (Pearman) (Psocoptera: Liposcelididae), a pest of stored products

Numerous strains of the psocid pest, Liposcelis decolor (Pearman) were collected from farms and central storages and interbred to form three representative strains from three major grain-growing states of Australia: Queensland, South Australia and New South Wales. These were tested against the grain protectants and structural treatments currently registered for use in Australia. Recently, L decolor has become an important pest of stored grain in Australia, particularly in the eastern and southern parts. There is no published information available on management of this pest and the current pest-management strategy, based predominantly on phosphine fumigation, has failed to control infestations of this pest in numerous grain storages in Australia. Alternative methods of control such as use of contact insecticides were explored in the present work to supplement phosphine fumigation to manage this new pest. From eight grain protectants tested as admixtures, only chlorpyrifos-methyl, bioresmethrin plus piperonyl butoxide, and fenitrothion were found to provide long term (3-9 months) protection against all three strains of L decolor. Chlorpyrifos-methyl gave the best protection, providing a minimum of 7.5 to a maximum of 9 months protection, depending on the strains tested. Three structural treatments, azamethiphos, azamethiphos plus carbaryl and permethrin provided long-term control (8-9 months) of all three strains of L decolor on galvanised steel surfaces, with permethrin delivering 9 months protection against all strains. However, all of these treatments failed to provide long-term control of any strains on concrete surfaces. We conclude that chlorpyrifos-methyl as a grain admixture can be incorporated into fumigation strategies to optimise the control of L decolor infestations. Structural treatments, such as permethrin can be used to support a fumigation strategy in storages made of galvanised steel.     

Fate of carbendazim in rice tissues after seed or foliage treatments

Carbendazim was quantified employing reversed-phase high-performance liquid chromatography in rice coleoptiles, radicles and shoot portions of seedlings of different ages grown from seeds treated with the fungicide, and in shoot portions of adult plants at different times after foliar treatment with the fungicide. The highest levels of carbendazim were detected in the coleoptiles four days after germination of seeds and the radicals contained the lowest concentrations. Carbendazim residues declined with time in the shoot portions of seedlings and of adult plants. However, the levels of carbendazim detected in the shoot tissues of 21-day-old seedlings grown from treated seeds [recommended dose of 10 mg a.i. 10g^?1 seeds] and in adult plants 35 days after treatment (recommended dose of 0.25 g a.i. litre^?1 spray fluid) correspond to the reported lasting ability of the fungicide in terms of protection against blast of rice.     

How Can Participatory Forest Management Cooperatives be Successful in Forest Resources Conservation? An Evidence From Ethiopia

ABSTRACT

In many parts of the world, community-based approaches to forest management have been evolving after recognizing that the top-down approach impedes conserving forests effectively. In Ethiopia also, local communities have been involved in participatory forest management (PFM) arrangements for better conservation of forest resources. However, the achievements in improving forest conservation outcomes have been mixed, while some PFMs are successful, others are not. Using data collected from 42 PFM cooperatives from Metema and Quara districts in Amhara dry forest region of Ethiopia, this study seeks to examine the variables that explain the variations in the performances of PFM cooperatives in forest conservation. The study has found that the performance of the PFM cooperatives depends on the key attributes of users, physical resources, and institutions and these attributes explain best for the success of PFMs. Therefore, the study suggests that these attributes along with the external factors like government policy must be given due importance while designing PFM arrangement. Moreover, just to highlight the impact of the external factors, the government policy like the resettlement program must be reconsidered; while the expansion of trade and infrastructure must be encouraged in order to strengthen the performance of PFMs and achieve forest conservation.