400 research outputs found

    Observation of Shelfwater Overrunning the Southern Slope Sea

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    Analyses of two years (1992 and 1993) of high resolution (1.47 km2) sea surface temperature satellite images of the southern Mid-Atlantic Bight (MAB), showed that unusually extensive overhang of shelf water occurs episodically, and coherently over along shelf distances of several hundred kilometers. These episodes are dubbed overrunning of the Slope Sea by shelf water. The overrunning volume has a face and a back (southern and northern limit). It transports substantial quantities of shelf water southward, and does not retreat onto the shelf, but eventually joins the western edge of the Gulf Stream in the vicinity of Chesapeake Bay. The correlation between satellite and in situ surface temperature, the location of shelf-slope front, and the relation of surface temperature to the deeper water mass were explored in order to quantify the overrunning episodes. The satellite extracted temperature profile agreed well with in situ surface temperature and coincident Expendable Bathythermographs (XBT) transects. The combined analyses of satellite imagery and various in situ data further demonstrated that the shelf water that over-run the Slope Sea are not mere surface features but can reach depths between 40 ∼ 60 m. Results confirm previous concepts on shelf circulation, shelf-slope exchange, fate of shelf water. They also sheds new light on shelfwater budget: overrunning of Slope Sea and southwest transport by upper slope current constitutes an important conduit for shelf water transport. Further analyses of potential causes for the overrunning events showed that wind stress due to winter storms moved the shelf-slope front and with it shelf water offshore to distances ∼10 to 40 km. The offshore displacement of shelf water also appeared to be related to the onshore veering of the Gulf Stream near Cape Hatteras. This veering of the Stream caused sea level to rise near Cape Hatteras producing a blocking effect on the shelf circulation. Such a blocking effect of the southwestward flow of shelf water in the MAB appeared to be the reason for the overruning of shelf water off New Jersey. In addition, the excess fresh water discharge from the St. Lawerence is also observed to be related to the flooding of shelf water off New Jersey

    Atherogenic dyslipidemia and diabetes mellitus: what’s new in the management arena?

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    When compared with the general population, the diabetic population is at higher risk of cardiovascular disease (CVD), as predicted by the Framingham Risk Score calculations (10-year risk 20%). For this reason diabetes is considered a “coronary disease equivalent” condition, as classified by the National Cholesterol Education Program Adult Treatment Panel (NCEP-ATP) III. Furthermore, patients with diabetes who experience a myocardial infarction have a poorer prognosis than nondiabetic patients, which contributes to their overall higher mortality. Dyslipidemia is a major underlying risk factor contributing to the excess CVD risk, and is usually more atherogenic in the presence of diabetes. It is uniquely manifested by raised levels of triglycerides, low levels of high-density lipoprotein cholesterol, and smaller, denser, and more atherogenic low-density lipoprotein particles. Recent trials have suggested the need for more aggressive treatment of dyslipidemia in this subpopulation than the current recommendations by the NCEP-ATP III. This review addresses the newer developments in the diabetes arena in terms of our current understanding of atherogenic dyslipidemia in diabetes and data from the latest randomized trials addressing its management

    Remote Sensing of Sea State by the Brewsters Angle Technique

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    The extent of plane polarised light resulting from Brewsters reflection from the wide-roughened sea surface is studied for various sea states on the assumption that the incident light on the air-sea interface is unpolarised. The sea states associated with different wind speeds are simulated using the Cox and Munk 'wind speed-wave slope' law and the Gaussian distribution of wave-slopes. The spatial distribution of plane polarised component of diffuse reflected light is also studied with a view to exploring possibilities of using this parameter for remote sensing of sea state from a sensor viewing the sea surface through an appropriate polaroid. The results show that the plane polarised fraction of reflected light as received in a given look angle can be directly related to the prevailing sea state and can be used as a convenient parameter for remote sensing of sea state. The scope and limitations of the method proposed are discussed

    Three Dimensional Space Vector Modulation Theory: Practices without Proofs

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    In three dimensional (3D) space vector modulation (SVM) theory with α-β-γ frame there are some issues which are well known and are widely practiced being quite obvious but without any proof so far. In this paper necessary scientific foundations to those issues have been provided. The foremost of these issues has been with the frame of reference to be considered in 3D SVM applications for unbalanced three phase systems. Although for balanced three phase systems there has been no controversy with α-β frame as the frame of reference but in 3D it has not yet been established which one, α-β-γ frame or the a-b-c frame, is mathematically correct. Another significant issue addressed in this work has been to ascertain the exact reason when a three phase system has to be represented in 2D or 3D space to apply SVM. It has been presented for the first time in this work that the key factor that determines whether 3D or 2D SVM has to be applied depends on the presence of time independent symmetrical components in a three phase ac system. Also it has been proved that the third axis, the Y–axis, represents the time independent quantity and that it must be directed perpendicular to the α-β plane passing through the origin

    Problems Of Improving Spoken Language Skills In Teaching Russian As A Foreign Language

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    While teaching Russian as a foreign language to undergraduate and postgraduate students in India, we observed that the learners quickly pick up writing skills, whereas their spoken language skills are not at the same level. There are many issues which need to be sorted out in order to improve spoken language skills. As written and spoken skills are different, we need to use different methods of teaching for each one of them. Since the first thing that is taught to students, who are learning a language, are alphabets, hence, initially the whole attention is turned towards improving their writing skills. Though, in the beginning, the students also do pick up an elementary level of spoken language, in the intermediate and advanced levels of learning, their spoken language skills suffer due to various factors. One of the main factors being the lack of exposure to the foreign language once the learners are out of the classroom. Since they continue to do homework, they keep in touch with the written skills. However, once they are out of the classroom, the learners and people around them use their own mother tongue or other native languages to speak. As a result, their spoken skills of the foreign language do not improve.Measures need to be taken for improving spoken skills: showing feature, as well as animation films; involving the students in discussions with the help of native speakers; providing audio books; showing them TV programs after class hours; involving learners in enacting Russian plays, etc. On the whole, artificial foreign language surroundings need to be created. Let us see how to motivate learners to speak as well as to write foreign language of their choice. Keywords: spoken skills, teaching Russian as a foreign language, learning problem

    Direct ultrafast laser written C-band waveguide amplifier in Er-doped chalcogenide glass

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    This paper reports the fabrication and characterization of an ultrafast laser written Er-doped chalcogenide glass buried waveguide amplifier; Er-doped GeGaS glass has been synthesized by the vacuum sealed melt quenching technique. Waveguides have been fabricated inside the 4 mm long sample by direct ultrafast laser writing. The total passive fiber-to-fiber insertion loss is 2.58 +/- 0.02 dB at 1600 nm, including a propagation loss of 1.6 +/- 0.3 dB. Active characterization shows a relative gain of 2.524 +/- 0.002 dB/cm and 1.359 +/- 0.005 dB/cm at 1541 nm and 1550 nm respectively, for a pump power of 500 mW at a wavelength of 980 nm. (C) 2012 Optical Society of Americ

    Management of Mycotoxin Contamination in Preharvest and Post Harvest Crops: Present Status and Future Prospects

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    Fungal secondary metabolites (mycotoxins) produced as contaminants on food and feed commodities are considered to be economically and toxicologically important world wide. Aflatoxins, orchratoxins, citrinin, fumonisins, zearalenone and trichothecenes are important mycotoxins which have been analysed as natural contaminants in various agricultural commodities. Many developed countries have laid down specific regulations for import and export of those items in terms of economic implications. In the light of present status different measures (prevention, elimination, and decontamination/inactivation) have been discussed in this review to minimize the risk of mycotoxin contamination in preharvest, harvest and post harvest conditions.Ajoy Kumar Choudhary and Priyanka Kumari. Management of Mycotoxin Contamination in Preharvest and Post Harvest Crops: Present Status and Future Prospects. J Phytol 2/7 (2010) 37-52
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