Gravitational wave scintillation by a stellar cluster

The diffraction effects on gravitational waves propagating through a stellar cluster are analyzed in the relevant approximation of Fresnel diffraction limit. We find that a gravitational wave scintillation effect - similar to the radio source scintillation effect - comes out naturally, implying that the gravitational wave intensity changes in a characteristic way as the observer moves.Comment: 9 pages, in press in IJMP

The effect of different treatments on improving seed germination characteristics in medicinal species of Descurainia sophia and Plantago ovata

Creating optimal conditions for germination of medicinal plants seed is essential for their cultivation. Therefore, to evaluate the effect of different treatments on seed germination of two medicinal species, Descurainia sophia and Plantago ovata collected in 2009 from Tehran Province, an experiment with a factorial randomized complete block design in 6 treatments with 4 replications was conducted. Treatments included KNO3 with concentrations of 0.1, 0.2 and 0.3%, acetylsalicylic acid with levels of 50 and 100 mg/l, prechilling (4°C for 10 days), thiourea with levels of 0.1 and 0.2%, boiling water for 5 and 10 min. To compare, distilled water was used as control. Results showed that the effect of different treatments on germination percentage of two medicinal species was significantly different (p < 0.05). It was shown that prechilling was the most effective treatment on seed germination of both species.Key words: Descurainia sophia, Plantago ovata, germination, acetylsalicylic acid, prechilling, thiourea and KNO3

A Survey on Routing in Anonymous Communication Protocols

The Internet has undergone dramatic changes in the past 15 years, and now forms a global communication platform that billions of users rely on for their daily activities. While this transformation has brought tremendous benefits to society, it has also created new threats to online privacy, ranging from profiling of users for monetizing personal information to nearly omnipotent governmental surveillance. As a result, public interest in systems for anonymous communication has drastically increased. Several such systems have been proposed in the literature, each of which offers anonymity guarantees in different scenarios and under different assumptions, reflecting the plurality of approaches for how messages can be anonymously routed to their destination. Understanding this space of competing approaches with their different guarantees and assumptions is vital for users to understand the consequences of different design options. In this work, we survey previous research on designing, developing, and deploying systems for anonymous communication. To this end, we provide a taxonomy for clustering all prevalently considered approaches (including Mixnets, DC-nets, onion routing, and DHT-based protocols) with respect to their unique routing characteristics, deployability, and performance. This, in particular, encompasses the topological structure of the underlying network; the routing information that has to be made available to the initiator of the conversation; the underlying communication model; and performance-related indicators such as latency and communication layer. Our taxonomy and comparative assessment provide important insights about the differences between the existing classes of anonymous communication protocols, and it also helps to clarify the relationship between the routing characteristics of these protocols, and their performance and scalability

Estimation of conservation value of myrtle (Myrtus communis) using a contingent valuation method: a case study in a Dooreh forest area, Lorestan Province, Iran

Background: Around 2000 plant species occur naturally in Lorestan Province of which 250 species are medicinal and myrtle is one of them. Myrtle is a shrub whose leaves and fruits have medicinal value and thus, if managed and harvested properly, could produce sustained economic benefits. In recent years, however, over half of the myrtle site areas was destroyed, due to inappropriate management and excessive harvesting practices. Thus, coming up with a practical harvesting approach along with identifying those factors damaging the sites, seems to be very crucial. Methods: In our investigation, we calculated the conservation value per hectare of myrtle in the Dooreh forest area in Lorestan Province. Using the Contingent Valuation (CV) and Double Bounded Dichotomous Choice (DBDC) methods, we determined the willingness to pay (WTP) for myrtle conservation. The WTP was estimated with a logit model for which indices were obtained based on a maximum precision criterion. Results: The results showed that 86.67 per cent of people were willing to pay for the conservation of these myrtle sites. Average monthly WTP per family was calculated as $0.79. The annual conservation value in terms of WTP for the preservation of the myrtle sites in Dooreh was estimated as$102,525. Among the variables of the model presented, education had a positive impact, while the amount proposed for payment and family size had a negative impact on the WTP. Conclusions: Our estimate of the value of myrtle conservation should provide justification for policy makers and decision making bodies of natural resources to implement policies in order to conserve the natural sites of this species more effectively. Keywords: Conservation value, Myrtle, Contingent valuation method, Double Bounded Dichotomous method, Logit mode

Perioperative glycemic control and its outcome in patients following open heart surgery

Background: Diabetes is not uncommon in patients requiring cardiac surgery. These patients have a higher incidence of morbidity and mortality. Subsequently, diabetes represents a major medico-economic problem in both developed and developing countries. This study was designed to observe the association between glycemic control and outcome of patients after open heart surgery in adult population.Materials and methods: Data was collected retrospectively in all patients who underwent open cardiac surgery (coronary artery bypass grafting, valve, or bypass grafting with valve surgery) and survived 72 hours postoperatively and had diabetes. The study was conducted from January 2015 to December 2016.Results: Of the 129 patients included in the study, male dominated 101 (78.3%). Most frequent surgery was coronary artery bypass grafting (CABG) 123 (95.3%), CABG plus aortic valve replacement 4 (3.1%), and CABG plus mitral valve replacement 2 (1.6%). Considering diabetes, only 3 (2.3%) were on diet control, 112 (86.8%) on oral hypoglycemic agents (OHA), whereas 9 (7%) had control on both insulin and OHA. Only 5 (3.9%) had type I diabetes. The mean fasting blood sugar (FBS) was 154.58 g/dl, and the mean duration of diabetic mellitus was observed 12.32 years. Microvascular and macrovascular complications were 26/129 (20.16%) and 17/129 (13.17%), respectively. Total 75 (58.1%) patients did not require insulin and 54 (41.9%) were treated with insulin intraoperatively to keep the blood glucose level less than 200 g/dl. Cardiac arrhythmias were frequent in the insulin group (P \u3c 0.05), which was also associated with increased stay in the cardiac intensive care unit.Conclusion: Inadequate glycemic control during open cardiac surgery can possibly lead to increased perioperative morbidity and mortality and with decreased long-term survival and recurrent ischemic events. Therefore, aiming for blood glucose levels around 140 mg/dl appears reasonable. Further studies are required to define specific glucose ranges for a clearer definition of recommended blood glucose goals in postoperative cardiac patients for the best outcomes in patients with diabetes mellitus

Association between nucleotide mutation of eNOS gene and serum level of vessel expansion factor (VEF) in non-smoker patients with vascular heart disease

Various mutation on endothelial nitric oxide synthase (eNOs) gene cause reduced production of NO, the expansion factor (VEF) and may accelerate the process of atherosclerosis. The study was designed to investigate the frequency of T-786C polymorphism of the gene or nucleotide mutation of eNOS gene in patients suffering from vascular heart disease (VHD) or coronary artery disease (CAD) in North West of Iran. 120 subjects including 60 patients with angiographically diagnosed CAD and 60 age and sex matched CAD-free subjects as control were studied. The levels of Nitric oxide in the samples were measured with the Griess method. The genotype studies were carried out using allele specific PCR. Comparing with the control reduced levels of NO were noticed in the patient group (P<0.05) and significantly high frequency of eNOs -786C genotype was found in CAD patients (P<0.05). The low levels of NO and increased frequency of T-786C polymorphism might be a risk factor in progression of coronary artery disease in the studied subjects.Keywords: Vascular heart disease, endothelial nitric oxide synthase gene, TC 786 SNP, vessel expansion factor (VEF), non-smokerAfrican Journal of Biotechnology Vol. 12(20), pp. 3023-302