350 research outputs found

    Heterosis and combining ability in winter wheat (Triticum aestivum L.)

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    A diallel cross involving seven parents and 21 hybrids was adopted to study heterosis and combining ability in wheat. F1 hybrids and parents were compared in space-planted experiments in two years. Ten hybrids gave significantly higher yield than the highest parent in the cross. The range for all hybrids was -13.8 to 75.9 per cent over the highest parent. Heterosis was obtained from hybrids within the soft red winter wheat group as well as from hybrids derived from hard red and soft white winter wheats. Heterosis was observed for all characters measured in some of the crosses. Greatest heterosis was observed in hybrids derived from crossing late and early maturity parents, a fact that could be important for the commercial utilization of hybrid wheat since it will be difficult to produce hybrid seed from parents that differ in time of anthesis. Heterosis was not observed in hybrids involving closely related parents indicating that genetic diversity is required for the expression of significant heterosis. Significant general and specific combining ability effects were obtained for yield and agronomically important traits. Tenn. 9, an experimental line, contributed positive general and specific combining ability effects for most characters. This study indicated that certain hybrids should be studied for heterosis under conditions of commercial production

    In situ aerosol optics in Reno, NV, USA during and after the summer 2008 California wildfires and the influence of absorbing and non-absorbing organic coatings on spectral light absorption

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    Hundreds of wildfires in Northern California were sparked by lightning during the summer of 2008, resulting in downwind smoke for the months of June and July. Comparisons are reported for aerosol optics measurements in Reno, Nevada made during the very smoky month of July and the relatively clean month of August. Photoacoustic instruments equipped with integrating nephelometers were used to measure aerosol light scattering and absorption coefficients at wavelengths of 405 nm and 870 nm, revealing a strong variation of aerosol light absorption with wavelength. Insight on fuels burned is gleaned from comparison of Ångström exponents of absorption (AEA) versus single scattering albedo (SSA) of the ambient measurements with laboratory biomass smoke measurements for many fuels. Measurements during the month of August, which were largely unaffected by fire smoke, exhibit surprisingly low AEA for aerosol light absorption when the SSA is highest, again likely as a consequence of the underappreciated wavelength dependence of aerosol light absorption by particles coated with non-absorbing organic and inorganic matter. Coated sphere calculations were used to show that AEA as large as 1.6 are possible for wood smoke even with non-absorbing organic coatings on black carbon cores, suggesting care be exercised when diagnosing AEA

    Human Immunodeficiency Virus Related Knowledge, Risk Perception and Practices among Married Women of Reproductive Age: A Cross-sectional Study from Mid-western Development Region, Nepal

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    Background: Despite the implementation of anti.human immunodeficiency virus (HIV) interventions, it has continued to spread from high risk to the low risk population population with the devastating social, economic and health consequences. Aim: The aim of the following study is to identify HIV related knowledge, risk perceptions and practices among married women of reproductive age (MWRA) in Mid-Western Development Region, Nepal.Subjects and Methods: A community based, cross.sectional study was conducted during May-December 2010 among 618 MWRA in Mid-western Development Region, Nepal. Multistage random sampling was followed wherein four districts, representing each ecological zone were selected in the first stage. Nine Village Developments Committees with the total 81 clusters were selected in the second and third stages. Finally, 7/8  participants/cluster were selected randomly. Household interviews were conducted using pretested structured questionnaire. Data were analyzed by SPSS 16.0 (SPSS Inc. Chicago, IL, USA). Percentages, mean, Chi-square value and odds ratio were calculated. Results: Nearly three quarters (434/618) of all participants had heard about the HIV. Radio was the most common source of the information 73.3% (318/434) amongst all sources. Unsafe sex 55.3% (240/434), infected blood transfusion 33.2% (144/434), needle sharing 24.7% (107/434) and mother to child transmission 4.1% (18/434) were reported modes of HIV transmission. Condom use during extramarital sex 51.8% (225/434), use of sterilized syringes 24.2% (105/434), restricting sex within couple 22.6% (98/434) and blood safety 20.3% (88/434) were reported HIV preventive measures. Extramarital sex, needle sharing and sharing of the razors/blades were perceived to be the risk behaviors. About 4.9% (30/618) had extramarital sexual experience amongst all participants. Only a quarter (8/30) of those who had extramarital sex used condom regularly.Conclusions: Almost half of the MWRA had limited awareness on HIV transmission and preventive measures. There was poor HIV preventive practices; indicating knowledge-behavior gaps. Awareness raising and behavior change interventions are recommended.Keywords: Human immunodeficiency virus, Knowledge, Married women of reproductive age, Nepal, Practice, Risk perceptio

    Rural unemployment in Nepal : the Chitawan Valley experience

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    The main aim of this study is to investigate the problem of rural unemployment in developing countries with special reference to the Chitawan Valley (in Nepal) experience. A brief review of the existing literature relating to the theoretical framework of the subject is undertaken first. This is followed by the required background information on Nepal. The general hypothesis postulated is that the valley, initiated as a resettlement area nearly a quarter of a century ago, is rapidly heading towards a labour surplus stage. Extreme inter and intra farm heterogeneity in the sample with respect to resource availability and input application necessitated the adoption of a synthetic farm approach. Farm size, land type and level of technology were considered to be the main criteria around which the synthetic farms were constructed. Various methodologies for measuring unemployment were discussed and the ’labour available versus labour required’ variant of the ’labour utilisation approach' was used. Accordingly, the labour utilisation rate was computed for each farm situation by comparing the labour employed (given by Leontief type fixed labour input coefficients) with the annual regular labour available. Given the small size of the sample (55 farming households) the application of the powerful nonparametric test was deemed effective to check the validity of the results. The analyses undertaken indicate the prevalence of underemployment in all the farm situations considered. Unemployment was generally identified as being only seasonal in nature and was concentrated during the winter months. The observed unemployment was attributed, in part, to the monsoonal pattern of agriculture. .Hence, promoting employment through irrigation development seems to be advisable

    T2FNorm: Extremely Simple Scaled Train-time Feature Normalization for OOD Detection

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    Neural networks are notorious for being overconfident predictors, posing a significant challenge to their safe deployment in real-world applications. While feature normalization has garnered considerable attention within the deep learning literature, current train-time regularization methods for Out-of-Distribution(OOD) detection are yet to fully exploit this potential. Indeed, the naive incorporation of feature normalization within neural networks does not guarantee an improvement in OOD detection performance. In this work, we introduce T2FNorm, a novel approach to training neural networks that transforms features to hyperspherical space through normalization, while employing non-transformed space for OOD-scoring purposes. This method yields a surprising enhancement in OOD detection capabilities without compromising model accuracy in in-distribution(ID). Our investigation demonstrates that the proposed technique substantially diminishes the norm of the features of all samples, more so in the case of out-of-distribution samples, thereby addressing the prevalent concern of overconfidence in neural networks. The proposed method also significantly improves various post-hoc OOD detection methods

    Distributions of fecal markers in wastewater from different climatic zones for human fecal pollution tracking in Australian surface waters

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    Recreational and potable water supplies polluted with human wastewater can pose a direct health risk to humans. Therefore, sensitive detection of human fecal pollution in environmental waters is very important to water quality authorities around the globe. Microbial source tracking (MST) utilizes human fecal markers (HFMs) to detect human wastewater pollution in environmental waters. The concentrations of these markers in raw wastewater are considered important because it is likely that a marker whose concentration is high in wastewater will be more frequently detected in polluted waters. In this study, quantitative PCR (qPCR) assays were used to determine the concentrations of fecal indicator bacteria (FIB) Escherichia coli and Enterococcus spp., HFMs Bacteroides HF183, human adenoviruses (HAdVs), and polyomaviruses (HPyVs) in raw municipal wastewater influent from various climatic zones in Australia. E. coli mean concentrations in pooled human wastewater data sets (from various climatic zones) were the highest (3.2 × 10 gene copies per ml), followed by those of HF183 (8.0 × 10 gene copies per ml) and Enterococcus spp. (3.6 × 10 gene copies per ml). HAdV and HPyV concentrations were 2 to 3 orders of magnitude lower than those of FIB and HF183. Strong positive and negative correlations were observed between the FIB and HFM concentrations within and across wastewater treatment plants (WWTPs). To identify the most sensitive marker of human fecal pollution, environmental water samples were seeded with raw human wastewater. The results from the seeding experiments indicated that Bacteroides HF183 was more sensitive for detecting human fecal pollution than HAdVs and HPyVs. Since the HF183 marker can occasionally be present in nontarget animal fecal samples, it is recommended that HF183 along with a viral marker (HAdVs or HPyVs) be used for tracking human fecal pollution in Australian environmental waters

    Virulence of Moroccan f. Revealed by International Differential Barley Genotypes

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    Pyrenophora teres f. teres (Ptt), causing net blotch in barley, is an important and frequently isolated leaf pathogen across the globe. The virulence spectrum of Ptt from North Africa including Morocco is poorly understood. Sixteen barley genotypes were challenged, at seedling stage, with 15 Ptt isolates that were collected from different agroecological zones of Morocco. The experiment was conducted in a factorial arrangement of treatments in a randomized complete block design with three replicates. The ANOVA revealed highly significant (P < 0.001) effects of genotype (G), isolate (I) and G×I interaction explaining 23.2, 62.5, and 13.9% of the variation, respectively. Therefore, the current study revealed highly diverse virulence pattern of Moroccan isolates. Furthermore, the results indicated that minor virulence of Ptt isolates dominated over virulence interaction. In addition, Taffa (6-rowed) and Aglou (2 rowed), had the highest level of resistance to Ptt, while Coast and Rabat071 were the most susceptible genotypes. Pt2, Pt7, Pt8 and Pt4 were being the most virulent isolates, while Pt10 and Pt11 were the least virulent isolates. The emergence of the new Ptt pathotypes, which were highly virulent to durable resistance in Rabat071 posed a risk of breaking down the currently deployed resistance to net blotch in Morocco. A careful evaluation and selection of Ptt isolates based on minor virulence pattern to barley genotypes is essential for successful barley breeding program for resistance to net blotch in Morocco
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