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1.
S. R. Barman    M. Gowda    R. C. Venu  B. B. Chattoo 《Plant Breeding》2004,123(3):300-302
Analysis of near‐isogenic lines (NILs) indicated the presence of a novel resistance gene in the indica rice cultivar ‘Tetep’ which was highly resistant to the rice blast fungus Magnaporthe grisea.‘Tetep’ was crossed to the widely used susceptible cultivar ‘CO39’ to generate the mapping population. A Mendelian segregation ratio of 3 : 1 for resistant to susceptible F2 plants further confirmed the presence of a major dominant locus, in ‘Tetep’, conferring resistance to the blast fungal isolate B157, corresponding to the international race IC9. Simple sequence length polymorphism (SSLP) was used for molecular genetic analysis. The analysis revealed that the SSLP marker RM 246 was linked to a novel blast resistance gene designated Pi‐tp(t) in ‘Tetep’.  相似文献   
2.
While wood has numerous attributes that make it an excellent material for many uses, its properties can also vary widely according to wood species and even within the same species. Wood used in structural applications is categorized into classes. For many wood products, these classes or grades are based upon visual assessments that account for grain characteristics along with natural defects such as knots or splits. These approaches are simple, but also limit the potential for identifying products based upon actual material properties. One alternative is to use acoustic tests to estimate modulus of elasticity and then correlate these values to actual material properties. The potential for using acoustic tests to estimate wood properties was assessed with a prototype acoustic device (Metriguard Model 242) on western juniper (Juniperus occidentalis) posts that were then tested using a destructive bending test. These tests could allow the identification of decayed areas within a post if they were directly in the tested area, but predicted modulus of elasticity was poorly correlated with actual modulus of rupture (r2?=?0.23). The correlation was improved by only considering those samples where the acoustic test was made through the same area where the test load was applied, but the relationship was still weak (r2?=?0.33). Acoustic testing did appear to be able to identify unacceptably weak samples with minimal rejection of acceptable samples, suggesting that acoustic testing might be a useful sorting tool to improve the reliability of timbers.  相似文献   
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4.
Hunger and health among undocumented Mexican migrants in a US urban area   总被引:1,自引:0,他引:1  
OBJECTIVES: To measure the occurrence and correlates of hunger and to evaluate the association between hunger and three health indicators among undocumented Mexican immigrants. DESIGN: Non-probability cross-sectional sample. SETTING: Neighbourhoods within New York City. SUBJECTS: Four hundred and thirty-one undocumented Mexican immigrants living in the USA. RESULTS: Hunger was indicated by approximately 28% of respondents. In a multivariate model, working as a day labourer was associated with hunger (odds ratio (OR) 3.33, 95% confidence interval (CI) 1.83-6.06) while receiving public assistance protected against hunger (OR 0.23, 95% CI 0.06-0.88). In multivariate models, respondents who reported experiencing hunger also reported poorer overall health (OR 1.69, 95% CI 0.95-3.02) and more days of poor mental (P = 0.045) and physical health (P < 0.0001). Greater amount of time lived in the USA was also associated with worse overall health (P = 0.054) and more days of poor mental and physical health (P < 0.01). CONCLUSIONS: The present study shows that food insecurity and hunger may be problems among undocumented migrants living in the USA. Uncertain and unpredictable work schedules and limited access to public assistance may contribute to high levels of hunger, which in turn may also negatively affect mental and physical health. Increasing amount of time lived in the USA is also associated with poorer health indicators. Programmes that provide undocumented migrants with emergency access to resources may reduce food insecurity and lead to improved health outcomes among this vulnerable population.  相似文献   
5.
Screening for newer bioactive compounds from microbial metabolites resulted in the isolation of a novel antibiotic from the culture filtrate, Streptomyces sp 201, of a soil. The bioactive compound, with antifungal and antibacterial activity, was identified as 2-methylheptyl isonicotinate. The antifungal activity of live culture, culture broth and the isolated bioactive compound showed marked inhibition against dominant soil-borne phytopathogens such as Fusarium oxysporum Schlect, F moniliforme Sheldon, F semitectum Berkeley & Ravenel, F solani (Martius) Sacc and Rhizoctonia solani Kuehn. The compound had no effect on seed germination and seedling development as displayed by root and stem growth of the test plant species. In pot experiments with seedlings of cruciferous plants such as Raphanus sativus L (radish), Brassica campestris L (yellow mustard), Brassica oleracea var botrytis L (cauliflower), the antibiotic compound showed promising protective activity of 92% when seeds of the test plants were treated at a dose of 50 micrograms ml-1 prior to sowing. Seed treatment with a spore suspension (3 x 10(8) spores ml-1) of the Streptomyces sp 201 displayed protective activity in the range of 56-60%. Seeds coated with 2.5% methyl cellulose-amended spores of the antagonist showed protective activity in the range of 64-72%. Further, seed treatment with the culture filtrate of the antagonist also showed promising protective activity in the range of 64-84%.  相似文献   
6.
Biology of the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) was studied on five orchids and one rose species under laboratory conditions. The duration of developmental stages of this mite was the shortest on rose (7.17 ± 0.20 days) followed by Cymbidium (10.49 ± 1.50 days), Oncidium (11.60 ± 1.32 days), Dendrobium (12.67 ± 0.21 days), Phalaenopsis (14.47 ± 1.21 days) and Coelogyne (17.10 ± 1.29 days). The number of eggs/female laid was maximum on rose, whereas the minimum was on Phalaenopsis under the most suitable temperature (26 ± 2°C) and relative humidity (65 ± 5%) conditions. The five orchid farms (three conventionally sprayed and two unsprayed) in the northeastern region of India were surveyed during 2009 and 2010 for mite incidence. Twenty-three species and 11 hybrids of orchids were encountered as the most preferred host, 12 species as moderately preferred, and 28 species and one hybrid were found to be the least preferred orchid host for T. urticae. The mite’s incidence was recorded on orchids all year round, indicative of overlapping generations; however, two distinct population peaks were recorded during April and May. Subsequently its population declined at the start of the rainy season and remained at extremely low levels in the winter. Maximum and minimum temperatures had a significant positive correlation with mite incidence; daylight had a non-significant positive correlation; and rainfall and relative humidity had non-significant negative correlations with mite incidence. The results are discussed in relation to the most susceptible stage on orchids and suitable management practices for the two-spotted spider mite in India.  相似文献   
7.
Keeping in mind to reduce chilling injury and retain quality; pomegranate (Punica granatum L., cv. Mridula) fruits were treated with putrescine, carnauba wax and putrescine + carnauba wax prior to cold storage at 2 °C. Before analyzing physical, physiological and biochemical parameters fruits were subjected to post cold storage exposure at 20 °C for 3 days. Untreated fruits developed rapidly chilling injury, with main symptoms being brown discolouration of the skin, surface pitting, weight and firmness loss during storage. All these undesirable changes were significantly delayed by putrescine + carnauba wax application. Respiration and ethylene evolution rate were also brought down by combined application of putrescine and carnauba wax treatment. The superiority of combine treatment over other applications seems arises due to additive benefit of antisenescence and barrier properties of putrescine and carnauba wax, respectively.  相似文献   
8.
For productive utilisation of effluent–contaminated agricultural land, mobilisation and statistical analysis of potentially toxic elements in soil and plants of fields irrigated with mixedindustrial effluent have been undertaken. Total Fe,Mn, Zn, Cu, Pb, Ni and Cr have been estimated in soiland plant species of contaminated and noncontaminatedsites. 18 plants species and 18 root adjacent soilsamples from contaminated Kalipur area and 11 plantsspecies and 11 root adjacent soil samples fromuncontaminated Madhabpur area comprising majorcrops, vegetables and weeds have been included in thestudy. It is revealed that Hibiscusesculentus, Lycopersicon esculentum and Luffa acutangula growing in effluent–contaminated field show mobilisation ratio <0.5 for most of the PTE (Potentially Toxic Elements) likeCu, Pb, Ni, Cr and Cd and normal morphology.Surprisingly, weeds in particular, show highmobilization ratio >0.5 and simultaneously exhibithealthy gigantic morphology at the early floweringstage. Coriandrum sativum, Raphhanussativus, Solanum melongena, Spinaceaoleracea, Oryza sativum, Brassica oleraceashowed mobilization ratio >0.5 butmaintained normal growth. Based on mobilization ratioand external morphology, we suggest the cultivation ofplants H. esculentus, L. acutangula, L. esculentum in land irrigated with industrial effluent. The highest andsecond highest enrichment factor (EFpp)was found for Cd and Pb, respectively. Pearson'scorrelation coefficient indicated that the metal levelin soil is not the main factor governing metaluptake. This study will help in selecting plantspecies for cultivation in contaminated fields.  相似文献   
9.
Aesthetic properties of fabrics have been considered as the most important fabric attribute for years. However, recently there has been a paradigm shift in the domain of textile material applications and consequently more emphasis is now being given on the mechanical and functional properties of fabrics rather than its aesthetic appeal. Moreover, in certain woven fabrics used for technical applications, strength is a decisive quality parameter. In this work, tensile strength of plain woven fabrics has been predicted by using two empirical modelling methods namely artificial neural network (ANN) and linear regression. Warp yarn strength, warp yarn elongation, ends per inch (EPI), picks per inch (PPI) and weft count (Ne) were used as input parameters. Both the models were able to predict the fabric strength with reasonably good precision although ANN model demonstrated higher prediction accuracy and generalization ability than the regression model. The warp yarn strength and EPI were found to be the two most significant factors influencing fabric strength in warp direction.  相似文献   
10.
Two experiments were conducted to investigate the effect of inland water salinity on growth performance, feed conversion efficiency and intestinal enzyme activity in grey mullet. In experiment I, a 90 day monoculture of grey mullet at different salinity levels (0, 10, 15, 20 and 25%) was carried out. The fingerlings were stocked at 5000 per hectare and fed on a supplementary diet at 5% BW d–1. This Study revealed that fish growth mean body weight (90.5 ± 4.5 g) and mean length (21.6 ± 0.4 cm), SGR (4.70%) and growth per day (0.99 g d–1) were significantly (p < 0.05) enhanced in fish maintained at 10% salinity in comparison with other treatments. Nutrient levels, phytoplankton population, NPP and chlorophyll a all decreased with an increase in salinity (>10%). In addition, zooplankton populations increased with an increase in the salinity level. Most of the other hydrochemical characteristics remained at optimal levels in all other treatments. Fish weight gain showed a significant positive correlation with productivity indicating parameters viz. alkalinity (r = 0.53), turbidity (r = 0.62), NPP (r = 0.75) and chlorophyll a (r = 0.46), clearly revealing that fish growth is also related to the trophic status of the ponds. In the second experiment (Experiment II), mullet fry were exposed to five different salinity levels (10, 15, 20, 25 and 30%) and maintained for 70 days in the laboratory. Significantly (p < 0.05) high growth, (SGR and per cent increase in body weight), feed conversion efficiency and intestinal enzyme activity were observed in the group maintained at 10 salinity in comparison with other groups maintained at similar salinity levels. Carcass composition, musc1e and liver glycogen levels were also significantly (p < 0.05) affected by salinity changes.  相似文献   
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