488 research outputs found

    A new gene for male sterility in pigeonpea (Cajanus cajan (L). Millsp.)

    Get PDF
    Several forms of female fertile and male sterile mutants in pigeonpea (Cajanus cajan (L). Millsp.) have been reported. A translucent anther type of male sterile characterised by non-separation of tetrads that is associated with a persistent tapetum is conditioned by a single recessive gene, ms1 (Reddy et al., 1977; Reddy et al., 1978). By contrast, a male sterile plant identified in breeding line B15B by Wallis et al. (1981) has shrivelled, arrowhead-shaped, non-dehiscent, brown-coloured anthers, and the pollen mother cells degenerate at the early tetrad stage (Dundas et al., 1981). This paper reports studies to determine the inheritance of the B15B male sterile character and its allelic relationship to the translucent anther type

    Zircon ages in granulite facies rocks: decoupling from geochemistry above 850 °C?

    Get PDF
    Granulite facies rocks frequently show a large spread in their zircon ages, the interpretation of which raises questions: Has the isotopic system been disturbed? By what process(es) and conditions did the alteration occur? Can the dates be regarded as real ages, reflecting several growth episodes? Furthermore, under some circumstances of (ultra-)high-temperature metamorphism, decoupling of zircon U–Pb dates from their trace element geochemistry has been reported. Understanding these processes is crucial to help interpret such dates in the context of the P–T history. Our study presents evidence for decoupling in zircon from the highest grade metapelites (> 850 °C) taken along a continuous high-temperature metamorphic field gradient in the Ivrea Zone (NW Italy). These rocks represent a well-characterised segment of Permian lower continental crust with a protracted high-temperature history. Cathodoluminescence images reveal that zircons in the mid-amphibolite facies preserve mainly detrital cores with narrow overgrowths. In the upper amphibolite and granulite facies, preserved detrital cores decrease and metamorphic zircon increases in quantity. Across all samples we document a sequence of four rim generations based on textures. U–Pb dates, Th/U ratios and Ti-in-zircon concentrations show an essentially continuous evolution with increasing metamorphic grade, except in the samples from the granulite facies, which display significant scatter in age and chemistry. We associate the observed decoupling of zircon systematics in high-grade non-metamict zircon with disturbance processes related to differences in behaviour of non-formula elements (i.e. Pb, Th, U, Ti) at high-temperature conditions, notably differences in compatibility within the crystal structure

    Clinical presentation and predictors of outcome in patients with severe acute exacerbation of chronic obstructive pulmonary disease requiring admission to intensive care unit

    Get PDF
    BACKGROUND: Severe acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) is a common reason for emergency room (ER) visit about which little has been documented from India. METHODS: Prospective study of the clinical presentation and predictors of outcome in 116 patients presenting with severe AE-COPD requiring admission to the medical intensive care unit between January 2000 and December 2004. RESULTS: Their mean age was 62.1 ± 9.8 years. There were 102 males. Mean duration of COPD was 7.2 ± 5.8 years. All males were smokers (22.3 ± 11.2 pack years); 35.2% smoked cigarettes and 64.8% smoked bidis. All women were exposed to domestic fuel. Associated co-morbid illnesses were present in 81 patients (69.8%); 53(45.7%) had one co-morbid illness and the remaining 28 (54.3%) had two or more co-morbid illnesses. Evidence of past pulmonary tuberculosis (PTB) was present in 28.4% patients; 5 patients who also had type II diabetes mellitus had active PTB. Arterial blood gas analysis revealed respiratory failure in 40 (33.8%) patients (type I 17.5% and type II 82.5%). Invasive mechanical ventilation was required in 18 patients. Sixteen (13.7%) patients died. Stepwise multivariate logistic regression analysis revealed need for invasive ventilation (OR 45.809, 95%CI 607.46 to 3.009;p < 0.001); presence of co-morbid illness (OR 0.126, 95%CI 0.428 to 0.037;p < 0.01) and hypercapnia (OR 0.114, 95%CI 1.324 to 0.010;p < 0.05) were predictors of death. CONCLUSION: Co-morbid conditions and metabolic abnormalities render the diagnosis of AE-COPD difficult and also contribute to mortality. High prevalence of past PTB and active PTB in patients with AE-COPD suggests an intriguing relationship between smoking, PTB and COPD which merits further study

    Intelligent intrusion detection system in smart grid using computational intelligence and machine learning

    Get PDF
    Smart grid systems enhanced the capability of traditional power networks while being vulnerable to different types of cyber-attacks. These vulnerabilities could cause attackers to crash into the network breaching the integrity and confidentiality of the smart grid systems. Therefore, an intrusion detection system (IDS) becomes an important way to provide a secure and reliable services in a smart grid environment. This article proposes a feature-based IDS for smart grid systems. The proposed system performance is evaluated in terms of accuracy, intrusion detection rate (DR), and false alarm rate (FAR). The obtained results show that the random forest and neural network classifiers have outperformed other classifiers. We have achieved a 0.5% FAR on KDD99 dataset and a 0.08% FAR on the NSLKDD dataset. The DR and the testing accuracy on average are 99% for both datasets

    Invertebrate 7SK snRNAs

    Get PDF
    7SK RNA is a highly abundant noncoding RNA in mammalian cells whose function in transcriptional regulation has only recently been elucidated. Despite its highly conserved sequence throughout vertebrates, all attempts to discover 7SK RNA homologues in invertebrate species have failed so far. Here we report on a combined experimental and computational survey that succeeded in discovering 7SK RNAs in most of the major deuterostome clades and in two protostome phyla: mollusks and annelids. Despite major efforts, no candidates were found in any of the many available ecdysozoan genomes, however. The additional sequence data confirm the evolutionary conservation and hence functional importance of the previously described 3′ and 5′ stem-loop motifs, and provide evidence for a third, structurally well-conserved domain
    • …
    corecore