8,200 research outputs found

    Optical data processing using paraboloidal mirror segments

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    An optical data processing system using paraboloidal reflecting surfaces is disclosed. In the preferred embodiment the paraboloidal reflecting surfaces are segments of a paraboloidal mirror. A source of coherent light is in the focal plane of the first paraboloidal mirror segment which collimates the beam and reflects it toward a second paraboloidal mirror surface. The information to be analyzed, on a transparency for example, is placed in the collimated beam. The beam is reflected from the second paraboloidal mirror segment and focused on a Fourier transform plane. A photon detector could be placed in the Fourier transform plane or suitable spatial filters, with the filtered beam then being reflected from a third paraboloidal mirror segment to be focused on a reconstruction plane

    Field and photon enhanced electron emission characteristics of cadmium sulphide field emitters

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    Field and photon enhanced electron emission characteristics of cadmium sulfide field emitter

    On the global well-posedness for the Boussinesq system with horizontal dissipation

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    In this paper, we investigate the Cauchy problem for the tridimensional Boussinesq equations with horizontal dissipation. Under the assumption that the initial data is an axisymmetric without swirl, we prove the global well-posedness for this system. In the absence of vertical dissipation, there is no smoothing effect on the vertical derivatives. To make up this shortcoming, we first establish a magic relationship between urr\frac{u^{r}}{r} and ωθr\frac{\omega_\theta}{r} by taking full advantage of the structure of the axisymmetric fluid without swirl and some tricks in harmonic analysis. This together with the structure of the coupling of \eqref{eq1.1} entails the desired regularity.Comment: 32page

    Sound speed and its attenuation in the Persian Gulf

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    High quality of commercial and research uses of acoustical methods in fisheries need to have enough information about sound speed variations, Ray tracing and attenuation rate in the water. In this paper we focused on sound speed variation with depth versus physical properties of Bandar Dayer waters (NE of Farsi island and about 50 kilometers south of Delware; 28.2 N & 50.58 E) and calculation of attenuation rate. Importance of this area is for the Gulf currents, which cover this region. The results of this research show that up to 11 meters depth sound speed remain constant while depth increases and temperature decreases. After this depth sound speed decreases which is for decreasing in salinity and temperature. Sound attenuation profiles show that the most attenuation rate is at 17 to 27 meters depth

    Molecular breeding for resilience in maize - A review

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    Abiotic and biotic constraints have widespread yield reducing effects on maize and should receive high priority for maize breeding research. Molecular Breeding offers opportunities for plant breeders to develop cultivars with resilience to such diseases with precision and in less time duration. The term molecular breeding is used to describe several modern breeding strategies, including marker-assisted selection, marker-assisted backcrossing, marker-assisted recurrent selection and genomic selection. Recent advances in maize breeding research have made it possible to identify and map precisely many genes associated with DNA markers which include genes governing resistance to biotic stresses and genes responsible for tolerance to abiotic stresses. Marker assisted selection (MAS) allows monitoring the presence, absence of these genes in breeding populations whereas marker assisted backcross breeding effectively integrates major genes or quantitative trait loci (QTL) with large effect into widely grown adapted varieties. For complex traits where multiple QTLs control the expression, marker assisted recurrent selection (MARS) and genomic selection (GS) are employed to increase precision and to reduce cost of phenotyping and time duration. The biparental mapping populations used in QTL studies in MAS do not readily translate to breeding applications and the statistical methods used to identify target loci and implement MAS have been inadequate for improving polygenic traits controlled by many loci of small effect. Application of GS to breeding populations using high marker densities is emerging as a solution to both of these deficiencies. Hence, molecular breeding approaches offers ample opportunities for developing stress resilient and high-yielding maize cultivars

    In vivo nematicidal potential of camel milk on Heligmosomoides polygyrus gastro-intestinal nematode of rodents

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    Following our previous fi ndings on the in vitro anthelmintic effect of camel milk on Haemonchus contortus, the current study aimed at investigating its in vivo effect. Investigations were carried out using mice infected with Heligmosomoides polygyrus which is a parasite commonly used to test the effi cacy of anthelmintics. Thirty six Swiss white mice of both sexes aged 5 – 6 weeks old, and weighing between 20 and 25 g were orally infected with 0.5 ml dose of 100, 1-week-old H. polygyrus infective larvae (L3 ). After the pre-patent period, infected animals were randomly divided into 6 groups of 6 animals each. The nematicidal effi cacy of camel milk was monitored through faecal egg count reduction (FECR) and total worm count reduction (TWCR). Four doses (8.25; 16.5; 33.0; 66.0 ml/kg body weight (bw)) for fresh camel milk and 22 mg/kg bw for albendazole were studied using a bioassay. Albendazole and 4 % dimethylsulfoxide were included in the protocol as reference drug and placebo, respectively. For all tested doses except 8.25 ml/kg bw, camel milk was effective in vivo against H. polygyrus reducing both faecal egg count and worm count (p < 0.05). The dose 66 ml/kg bw showed the highest nematicidal activity causing a 76.75 % FECR and a 69.62 % TWCR 7 day after initiating the treatment. These results support the possible use of camel milk in the control of gastro-intestinal helminthiasis

    Trends in breeding oat for nutritional grain quality - An overview

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    Oat is an economically important crop and ranks sixth in world cereal production after maize, wheat, rice, barley and sorghum. It has been primarily utilized as livestock feed. However, the utilization of oats for human consumption has increased progressively, owing to its dietary and health benefits which relies mainly on the total dietary fibre and ?-glucan content, which significantly reduces postprandial blood glucose, insulin and blood lipids, especially serum total and low density lipoprotein cholesterol. Henceforth, enhancing Oat b-glucan content forhuman consumption is desirable. As it is a polygenic trait controlled mainly by genes with additive effects, phenotypic selection for greater b-glucan content would be effective for developing cultivars with elevated b-glucan contents. Oat b-glucan concentration has been found to be positively correlated with protein content and negatively correlated with oil content. ?-glucan yield (i.e., Product of grain yield and ?-glucan content) has been found to correlate positively with both grain yield (r = 0.92) and ?-glucan content (r = 0.66). Hence, this nutritional oat grain quality has been improved through selection for improved grain yield as they both increase simultaneously. Among wild accessions, A. atlantica genotypes have high ?-glucan content (2·2–11·3%) and have been used in breeding programmes for increasing the ?-glucan content of adapted elite local germplasm. Besides conventional breeding approaches, molecular breeding approaches have made possible to identify several molecular markers linked to ?-glucan rich regions across oat genome hence enabling mapping and dissection of ?-glucan rich genomic regions and accelerating the improvement in nutritional grain quality

    Analysis of CLDN14 gene in deaf Moroccan patients with non-syndromic hearing loss

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    Mutations in the CLDN14 gene, encoding the tight junction claudin 14 protein has been reported to date in an autosomal recessive form of isolated hearing loss DFNB29. In order to identify the contribution of CLDN14 to inherited deafness in Moroccan population, we performed a genetic analysis of this gene in 80 Moroccan familial cases. Our results show the presence of 7 mutations: 6 being conservative and one leading to a missense mutation (C11T) which was found at heterozygous and homozygous states, with a general frequency of 6.87%. The pathogenicity of the resulting T4M substitution is under discussion. Finally, our study suggests that CLDN14 gene can be implicated in the development of hearing loss in the Moroccan population

    fMRI Randomized Study of Mental and Motor Task Performance and Cortisol Levels to Potentiate Cortisol as a New Diagnostic Biomarker.

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    Cortisol is an important hormone in the protective stress response system, the Hypothalamus-Pituitary-Adrenal (HPA axis). It becomes especially salient in immune suppression syndromes such as multiple sclerosis and Cushing’s disease. Fatigue is a common symptom and mental and motor tasks are difficult and labored. The role of cortisol is mental and motor tasks and the recruitment of key brain regions in completion of these tasks is explored together with functional magnetic resonance imaging in healthy participants. Cortisol levels were found to be higher and had greater reduction in levels during mental versus motor tasks. Recruitment of brain stem and hypothalamus regions, important in cortisol activity, was affected differently. At low cortisol levels, mental task participants had less activity in the regions than their physical task counterparts. When cortisol levels were higher, widerspread recruitment of these brain regions was seen in the mental task participants, and for the physical task participants, the spread was at comparative low levels of cortisol. It is concluded that cortisol is implicated in these brain regions supporting the Thompson Cortisol Hypothesis and that brain region recruitment is likely to be dependent upon factors including cortisol levels as well as perception of stress in the task. It is suggested that mental tasks are perceived more stressful than physical but demand higher cortisol levels to promote wider spread brain region activity. Implication for neurological disease includes the use of cortisol in the proposed development of a potential new diagnostic biomarker for early detection of neurological sequelae

    Proceedings of the Second workshop on scientific results of FORV Sagar Sampada

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    Since inception in 1984, the Fisheries and Oceanographic Research Vessel Sagar Sampada, with sophisticated modern facilities onboard, has undertaken more than 140 cruises all over the Indian Ocean primarily in our Exclusive Economic Zone for fishery and oceanographic survey. Scientists from many institutions have made use of this facility to explore the resource potential in our sea and to understand its correlation with the environmental parameters. These survey and exploration efforts are continuing. This volume contains many papers which are the outcome of research work carried out onboard 'Sagar Sampada' during last five years (1989-1993) and presented in a Workshop to evaluate the scientific work. About 60 papers, included in this volume, bring out the results pertaining to environmental assessment, hydrology, productivity estimates, fishery resources availability, fishing technology, pollution monitoring etc. These relate mainly to the Arabian Sea, Bay of Bengal and Lakshadweep, Andaman and Nicobar Islands groups in the EEZ of India. These efforts along with other mission-oriented cruises have yielded valuable information on the fishery resources and their distribution in space and time
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