36 research outputs found

    The effects of different warm stratification periods on the seed germination of some Rosa taxa

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    In this study, the effects of different warm stratification periods on the seed germination of some Rosa species such as Rosa heckellana ssp. vanheurckiana, Rosa canina, Rosa pulverelanta and Rosa dumalis naturally grown in the Van region were investigated. In 2007, seeds of these species were kept at 25°C warm stratification for 10, 11 and 12 weeks, and then transferred to 5°C for cold stratification till the initiation of germination. Germination response to treatments of R. heckellana ssp. vanheurckiana seeds was different compared to the other species. The seeds of R. heckellana ssp. vanheurckiana germinated in a short time (when they kept in warm stratification followed by cold stratification between 1 - 3 weeks). The seeds of the other species required 5 months of cold stratification after warm stratification to overcome seed dormancy. The overall germination percentage were 18.80% in R. canina, 13.80% in R. pulverelanta and 13.53% in R. dumalis at 25°C of warm stratification followed by 5°C cold stratification. We determined that for these three taxa, the most appropriate method of stratification was 11 week warm stratification followed by cold stratification

    First results from the CRESST-III low-mass dark matter program

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    The CRESST experiment is a direct dark matter search which aims to measure interactions of potential dark matter particles in an earth-bound detector. With the current stage, CRESST-III, we focus on a low energy threshold for increased sensitivity towards light dark matter particles. In this manuscript we describe the analysis of one detector operated in the first run of CRESST-III (05/2016-02/2018) achieving a nuclear recoil threshold of 30.1eV. This result was obtained with a 23.6g CaWO4_4 crystal operated as a cryogenic scintillating calorimeter in the CRESST setup at the Laboratori Nazionali del Gran Sasso (LNGS). Both the primary phonon/heat signal and the simultaneously emitted scintillation light, which is absorbed in a separate silicon-on-sapphire light absorber, are measured with highly sensitive transition edge sensors operated at ~15mK. The unique combination of these sensors with the light element oxygen present in our target yields sensitivity to dark matter particle masses as low as 160MeV/c2^2.Comment: 9 pages, 9 figure

    Limits on Dark Matter Effective Field Theory Parameters with CRESST-II

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    CRESST is a direct dark matter search experiment, aiming for an observation of nuclear recoils induced by the interaction of dark matter particles with cryogenic scintillating calcium tungstate crystals. Instead of confining ourselves to standard spin-independent and spin-dependent searches, we re-analyze data from CRESST-II using a more general effective field theory (EFT) framework. On many of the EFT coupling constants, improved exclusion limits in the low-mass region (< 3-4 GeV) are presented.Comment: 7 pages, 9 figure

    A Low Nuclear Recoil Energy Threshold for Dark Matter Search with CRESST-III Detectors

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    The CRESST-III experiment (Cryogenic Rare Events Search with Superconducting Thermometers), located at the underground facility Laboratori Nazionali del Gran Sasso in Italy, uses scintillating CaWO₄ crystals as cryogenic calorimeters to search for direct dark matter interactions in detectors. A large part of the parameter space for spin-independent scattering off nuclei remains untested for dark matter particles with masses below a few GeV/c², despite many naturally motivated theoretical models for light dark matter particles. The CRESST-III detectors are designed to achieve the performance required to probe the low-mass region of the parameter space with a sensitivity never reached before. In this paper, new results on the performance and an overview of the CRESST-III detectors will be presented, emphasizing the results about the low-energy threshold for nuclear recoil of CRESST-III Phase 1 which started collecting data in August 2016. Keywords: Cryogenic detectors; Dark matter; Rare-event searche

    Prediction of the hot metal silicon content in the Blast Furnace [Yüksek Firinda Sicak Metaldeki Silisyum Orani Tahmini]

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    24th Signal Processing and Communication Application Conference, SIU 2016 --16 May 2016 through 19 May 2016 -- --Transforming of raw iron ore to liquid hot metal is operated at blast furnace which is one of the main unit of integrated iron and steel factories. Silicon content of liquid hot metal is the most important parameter concerning of product quality and blast furnace thermal condition. In this study a prediction model is established with artificial neural network's multilayer perceptron module by using 564 heat data of Iskenderun Iron & Steel Plant (ISDEMIR) Blast Furnace No 3. The silicon content of the next heat is predicted with accuracy of 83%. © 2016 IEEE

    Transcatheter embolization of coronary to pulmonary artery fistula with coronary steal phenomenon - A case report

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    Percutaneous transcatheter closure technique of a coronary artery fistula with a coil was performed in a 32-year-old man who had stable angina pectoris and myocardial ischemia in thalium myocard scintigraphy. Complete closure of the fistula without any complications was confirmed by angiography after the procedure. Angina pectoris disappeared and thalium scintigraphy was normal after the transcatheter embolization of fistula

    Therapeutic versus prophylactic plus therapeutic administration of omega-3 fatty acid on endotoxin-induced peridontitis in rats

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    PubMed ID: 15732866Background: The aim of the present study was 1) to evaluate the possible effects of therapeutic usage of omega-3 fatty acid on the gingival tissue levels of prostaglandin E2 (PGE2), prostaglandin F2? (PGF2?), platelet activating factor (PAF), and leukotriene B4 (LTB4) in endotoxin-induced periodontitis in rats and 2) to investigate whether prophylactic usage provides any additional benefits to therapeutic doses of omega-3 fatty acid. Methods: Experimental periodontitis was induced by repeated injection of Escherichia coli lipopolysaccharide (LPS). Thirty-six adult male Sprague-Dawley rats were divided into four study groups: 1) saline controls; 2) LPS; 3) therapeutic omega-3 fatty acid (TO3); and 4) prophylactic plus therapeutic omega-3 fatty acid (P + TO3) groups. In TO3 group, omega-3 fatty acid was given for 15 days following induction of experimental periodontitis. In P + TO3 group, omega-3 fatty acid was started 15 days before baseline, and then periodontitis was induced at baseline and omega-3 fatty acid was continued for 15 days after baseline. On day 15 after baseline, all rats were anesthetized and sacrificed. PGE2, PGF2?, and LTB4 levels in gingival tissue samples were analyzed by enzyme immunoassay and PAF levels were analyzed by radioimmonoassay. Data were evaluated statistically by using parametric tests. Results: LPS injection resulted in significant amount of bone loss (P &lt;0.05). Neither therapeutic nor prophylactic plus therapeutic administration of omega-3 fatty acid with the doses and duration of therapy used in the present study was effective in preventing endotoxin-induced alveolar bone loss. TO3 group exhibited significant decreases in the gingival tissue levels of PGE2, PGF2?, LTB4, and PAF compared to the LPS group (P &lt;0.05). PGE2 and PGF2? levels in TO3 group were similar to those of the saline group (P &gt;0.05), while LTB4 and PAF levels were statistically higher than the saline group (P &lt;0.05). Prophylactic plus therapeutic usage of omega-3 fatty acid provided similar levels of all these mediators to those of the saline controls (P &gt;0.05). Conclusions: Therapeutic omega-3 fatty acid significantly reduced the gingival tissue levels of PGE2, PGF2?, LTB4, and PAF in experimental periodontitis. Furthermore, prophylactic usage of omega-3 fatty acid provided additional beneficial effects to the therapeutic administration by decreasing the gingival tissue levels of these mediators to levels of healthy tissue. These findings should be verified by longitudinal clinical trials investigating clinical and biochemical periodontal parameters to better define the possible role of omega-3 fatty acids in periodontal treatment
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