1,698 research outputs found

    Horizon fluff, semi-classical black hole microstates - Log-corrections to BTZ entropy and black hole/particle correspondence

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    According to the horizon fluff proposal microstates of a generic black hole belong to a certain subset of near horizon soft hairs that cannot be extended beyond the near horizon region. In [1,2] it was shown how the horizon fluff proposal works for AdS3 black holes. In this work we clarify further this picture by showing that BTZ black hole microstates are in general among the coherent states in the Hilbert space associated with conic spaces or their Virasoro descendants, provided we impose a (Bohr-type) quantization condition on the angular deficit. Thus BTZ black holes may be viewed as condensates (or solitonic states) of AdS3 particles. We provide canonical and microcanonical descriptions of the statistical mechanical system associated with BTZ black holes and their microstates, and relate them. As a further non-trivial check we show the horizon fluff proposal correctly reproduces the expected logarithmic corrections to the BTZ entropy.Comment: 47pp, v2: added references, minor correction in section 6.1, results unchanged, v3: 51pp, added figures, references and clarifications, to appear in JHE

    Holographic Chern-Simons Theories

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    Chern-Simons theories in three dimensions are topological field theories that may have a holographic interpretation for suitable chosen gauge groups and boundary conditions on the fields. Conformal Chern-Simons gravity is a topological model of 3-dimensional gravity that exhibits Weyl invariance and allows various holographic descriptions, including Anti-de Sitter, Lobachevsky and flat space holography. The same model also allows to address some aspects that arise in higher spin gravity in a considerably simplified setup, since both types of models have gauge symmetries other than diffeomorphisms. In these lectures we summarize briefly recent results.Comment: 20 pp, invited lectures prepared for the 7th Aegean Summer School "Beyond Einstein's Theory of Gravity", 201

    The effects of guided imagery on state and trait anxiety and sleep quality among patients receiving hemodialysis: A randomized controlled trial

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    Abstract Objective This study aimed to investigate the effects ofguided imagery on state and trait anxiety and sleep quality among hemodial ysis patients. Design This was a randomized controlled trial. A total of seventy hemodialysis patients were assigned through block randomization to either an intervention group to receive guided imagery or a control group to receive routine care services. Setting The study was performed in the hemodialysis unit of Akhavan teaching hospital, Kashan, Iran. Intervention In addition to routine care services, patients in the intervention group received guided imagery six times a week for four successive weeks via listening to a guided imagery instructional compact disk and following the instructions. Primary outcomes Before and four weeks after the intervention, state and trait anxiety and sleep quality were measured via Spielberger’s State-Trait Anxiety Inventory and Pittsburgh Sleep Quality Index. Results The results of analysis of covariance showed that the intervention and the control groups significantly differed from each other respecting the posttest mean scores of state anxiety (adjusted mean difference: –9.11; 95% CI = –10.26 to_–7.96; P < 0.001), trait anxiety (adjusted mean difference: –8.94; 95% CI = –10.31_to –7.57; P < 0.001), and sleep quality (adjusted mean difference: –0.877; 95% CI = –1.51_to –0.24; P < 0.007). Conclusions Guided imagery can significantly alleviate anxiety and improve sleep quality among hemodialysis patients. Nurses are recommended to use guided imagery to alleviate hemodialysis patients’ anxiety and improve their sleep quality. Keywords: Anxiety Sleep quality Guided imagery Hemodialysi

    Comparison of four ways in treatment of acute conversion disorder

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    چکیده: زمینه و هدف: با وجود شیوع قابل توجه اختلال تبدیلی توافق چندانی در مورد مؤثرترین روش درمان آن وجود ندارد. این مطالعه با هدف مقایسه اثر بخشی چهار روش درمانی اختلال تبدیلی حاد و عود یکماهه آن انجام شد. روش بررسی: در این مطالعه کارآزمایی بالینی 80 بیمار مبتلا به اختلال تبدیلی حاد به روش نمونه گیری آسان انتخاب و به صورت تصادفی تحت درمان با چهار روش تلقین، آرامسازی عضلانی ساده، هیپنوز و تزریق وریدی دیازپام قرار گرفتند. سرعت حذف علامت، فراوانی بهبودی و عود یک ماهه در آنها مقایسه و داده ها به وسیله آزمون های کای دو، فیشر و آنکوا تجزیه و تحلیل گردید. یافته ها: میانگین زمان بهبودی در روش آرامسازی عضلانی نسبت به روش تزریق دیازپام و هیپنوز بطور معنی داری کمتر بود (05/0

    Comparison of four ways in treatment of acute conversion disorder

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    Abstract: (10784 Views) Background and aim: In spite of high prevalence of conversion disorder, there is no widely acceptable effective treatment for it. In this study, we compared four ways of treatment in acute conversion disorder and it’s recurrent after one month. Methods: In a clinical trial study, we selected 80 patients with acute conversion disorder using simple sampling method. They were divided randomly into four treatment groups. (Suggestion, simple muscle relaxation, hypnosis, and diazepam injection) The speed of syndrome elimination, recovery frequency, and one month’s recurrence were compared. The results were analyzed with chi-square, Fisher’s exact test and ANOVA. Results: Mean recovery time was significantly less in muscle relaxation group compared to the hypnosis and diazepam injection groups (P<0.05). In patients with co-morbidity, the mean recovery time was shorter than the mean recovery time in none co-morbidity (P<0.05). There was no significant relation between one month recurrent and way of treatment or other variables. Conclusion: All four ways of treatments bring significant recovery, but in muscle relaxation, recovery is faster than hypnosis and diazepam infusio

    The Effect of Stevia Rebaudiana on Serum Omentin and Visfatin Level in STZ-Induced Diabetic Rats

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    Recently the role of adipocytokines in relationship to incidence of diabetes has been demonstrated. One of the medicinal plants that are used in the treatment of diabetes is stevia. This study investigates the effect of stevia on serum omentin and visfatin levels as novel adipocytokines in diabetic induced rats to find potential mechanisms for the anti hyperglycemic effect of stevia. Forty male wistar rats weighing 180–250 g were induced with diabetes by intraperitoneal injection of streptozotocin (STZ). The animals were divided into 5 groups of 8. Rats in group 1 (non-diabetic control) and group 2 (diabetic control) were treated with distilled water, and the rats in the treated groups, group 3 (T250), group 4 (T500), and group 5 (T750) were treated with stevia, gavaged every day at 9 a.m. in doses of 250, 500, and 750 mg/kg, respectively. At the end of the study significant reductions in fasting blood sugar (FBS), the homeostasis model assessment insulin resistance (HOMA-IR), triglyceride (TG), alkaline phosphatase (ALP), and Omentin level were found in groups 3 and 4 in comparison with group 2. Pancreatic histopathology slides demonstrated that stevia extract did not induce any increase in the number of β-cells. The conclusion is that prescription of stevia in the doses of 250 and 500 mg/kg/d decreases the omentin level indirectly via activating insulin sensitivity and lowering blood glucose in STZ-induced diabetic rats. KEYWORDS. Diabetes, omentin, stevia, visfati
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