Robust Resource Allocation for OFDM-based Cognitive Radio in the Presence of Primary User Emulation Attack

Cognitive radio (CR) is a promising solution to improve the spectrum efficiency in which some unlicensed users are allowed to exploit frequency bands which are not used by licensed network. However, CR technology imposes some threats to the network. One of these threats is primary user emulation attack where some malicious users try to send fake signals similar to the primary user (PU) and prevent secondary users from accessing vacant bands. Moreover, the presence of a primary user emulation attacker (PUEA) leads to additional interference to the CR and consequently, the efficiency of conventional power loading algorithms will be degraded. In this paper, we propose a power allocation scheme in an orthogonal frequency-division multiplexing (OFDM) based CR in the presence of PUEA. Power allocation is performed with the aim of maximizing the downlink transmission capacity achieved by the cognitive user, while keeping the interference level at the PU below a predefined threshold. Simulation results confirm the efficiency of our proposed power loading scheme, compared to classical loading algorithms that do not consider the activity of malicious users in the radio environment

Protective effects of gallic acid against chronic cerebral hypoperfusion-induced cognitive deficit and brain oxidative damage in rats

Free radical induced neural damage is implicated in cerebral hypoperfusion disorders and antioxidants have protective effects. In the present study, we examined the effect of gallic acid (GA; 100 mg/kg, p.o. for 10 days) on cognitive deficit and cerebral oxidative stress induced by permanent bilateral common carotid artery occlusion (2VO) as an animal model of vascular dementia (VD). The results showed that 2VO significantly reduced the spatial memory performance in Morris water maze as well as non enzymatic (total thiol) and enzymatic glutathione peroxidase (GPx)] antioxidant contents and increased the level of malondialclehyde (MDA) in the hippocampus and frontal cortex of vehicle-treated group as compared to sham-operated rats. Furthermore, chronic administration of GA significantly restored the spatial memory, total thiol and GPx contents and also decreased MDA levels in these tissues. GA alone did not show any change neither in the status of various antioxidants nor behavioral tests over sham values. The results demonstrate that GA has beneficial activity against 2VO-induced cognitive deficits via enhancement of cerebral antioxidant defense. Taken together, the present study suggested that GA might be useful in the treatment of VD. (C) 2014 Elsevier B.V. All rights reserved

Effect of Vitamin C on Serum Cortisol after Etomidate Induction of Anesthesia

Objectives: Etomidate is suitable for induction of anesthesia, especially in elderly patients and patients who have cardiovascular compromise. Vitamin C has been introduced as a treatment option to decrease Etomidate induced adrenal insufficiency but its actual effect is still controversial. Objective is to determine the effect of Vitamin C on reduction of serum cortisol after etomidate induction of anesthesia. Methods: In a randomized clinical trial, 40 patients of ASA class I & II, aged between 25 to 70 years old, candidate for elective laparatomy were selected. One hour before induction of surgery, 1 gram of intravenous Vitamin C were administered to the patients in Vitamin C group. Two blood samples were obtained 5 minutes before induction and then another sample 4 hours after induction with etomidate after surgery. All samples were measured for serum free cortisol, ACTH, and C-reactive protein (CRP). Results: There were no significant differences between duration of surgery, preoperative and post-operative blood pressure and heart rate in two groups (p>0.05). Serum cortisol was significantly declined in control group from 16.2±6.3 μg/dl in preoperative to 8.5±4.2 in postop (p=0.0005), but not in Vitamin C group from 17.5±5.6 in preop to 16.8±6.4 in postop (p=0.75). ACTH levels increased non-significantly from preop to postop period in both Vitamin C (pre: 52.1±15 vs. post: 56.4±18 pg/ml) (p=0.48) and in control group (pre:50.5±16 vs. post:56.2±20). Conclusion: Etomidate could significantly decrease postoperative serum free cortisol and induce adrenocortical suppression and CRP increase. This effect could be reversed by using Vitamin C premedication to maintain serum cortisol at preoperative level

Frontiersman’s Identity in Cormac McCarthy’s No Country for Old Men: A Contrapuntal Reading

This study aims to offer a contrapuntal reading of Cormac McCarthy’s Western novel No Country for Old Men (2005) by drawing on the notion of frontiersman’s identity. McCarthy has been predominantly viewed as a revisionist in his politics of representing the myth of American West, yet little attention has been given to the way in which this novel calls into question the public view of him as a writer who revises and critiques the myth of the West. From a contrapuntal perspective, we argue that although the text depicts the failure of the frontiersman, in particular Sheriff Bell, in contemporary society, through nostalgia for older times the writer keeps the frontiersman’s dream and hope alive. Furthermore, we problematize the very older times for which the protagonist Bell expresses his nostalgia for. We argue that these nostalgic older times have been also a period of bloodshed and violence regarding other nationalities and ethnicities whose voice is not heard in this narrative. McCarthy’s text is indeed silent about the sufferings of those represented as the other, the Vietnamese for instance, in the text

Effect of Dexamethasone on Striatal Neurotransmissions in the Rats Subjected to Parkinson’s Disease Animal Model

Objective(s)The aim of this study was to evaluate the effects of dexamethasone on striatal dopaminergic, glutamatergic and gamma amino butyric acid (GABA) ergic neurotransmission in normal and parkinsonian rats.Materials and MethodsDexamethasone (0.15, 0.30, 0.60 and 0.8 mg/kg) was administered to normal or parkinsonian rats (i.p.) followed by the analysis of the striatal neurotransmitters concentrations. Additionally, the effect of dexamethasone on the damaged Substantia nigra pars compata (SNc) neurons has been investigated. ResultsDexamethasone resulted in decreased level of striatum glutamatergic-GABAergic and enhanced dopaminergic neurotransmission in normal and parkinsonian rats. In addition, acute treatment with dexamethasone did not improve the lesion at all. ConclusionThese findings suggest the new therapeutic mechanism of action for dexamethasone in Parkinson’s disease animal model

Biological Effects of Magnetic Resonance Imaging on Testis Histology and Seminiferous Tubules Morphometry.

OBJECTIVES: Spermatogenesis is a regular and lengthy process in which the function of testicular cells may potentially be influenced by several extrinsic and intrinsic stressors, including environmental factors such as magnetic resonance imaging (MRI) waves and radiation. Our study aimed to investigate the effects of MRI waves and fields on the testicular histology and morphometry of seminiferous tubules in mice. METHODS: The experiment was conducted on 40 adult Naval Medical Research Institute mice. The control group was located in the center of the MRI bore while it was turned off, while the exposed group was exposed to the active scanner for 36 minutes once a week for three weeks. Our study included four groups: group I (control group at one hour after last exposure), group II (experimental group at one hour after last exposure), group III (control group at 35 days after last virtual exposure), and group IV (experimental group at 35 days after last exposure). We then assessed the tube and lumen diameters, as well as epithelium thickness of the seminiferous tubules. RESULTS: Our data showed that MRI waves partially reduced testicular weight one hour after the last exposure (group II) compared to group I (p = 0.240). On the other hand, in group II the Johnson's score (score 10, complete spermatogenesis and perfect tubules) was 87.5% which was slightly less than recorded in groups I, III, and IV (91.4%, 92.2%, and 90.5%, respectively). Furthermore, the MRI in group II revealed induces vacuolization in the epithelium, arrest in primary spermatocytes in the pachytene stage as well as disruption in the testicular parenchyma. CONCLUSIONS: Long-term exposure to MRI waves has deleterious effects on the male reproductive system, fertility parameters, and the quantity of germ cells in the seminiferous tubules with the exception of the number of round spermatid cells and epithelial thickness. All these effects were reversible after a new period of spermatogenesis. The OMJ is Published Bimonthly and Copyrighted 2019 by the OMSB. KEYWORDS: Fertility; Magnetic Resonance Imaging; Mice; Seminiferous Tubules; Spermatogenesis; Testi

Design of single-mode single-polarization large-mode-area multicore fibers

ABSTRACT: In laser science and industry, considerable effort is directed toward designing fibers for fiber laser and fiber amplifier applications, each of which offers a particular advantage over the others. Evanescently coupled multicore fibers, however, have been studied less extensively due to the relatively small mode area in the single-mode regime. Here, by proposing a new structure with stress-applying parts in a 37-core fiber and optimizing this structure through a comprehensive framework, we present 21 solutions characterized by large-mode-area and high beam quality in the single-mode, single-polarization regime. Different fiber designs are optimal for different output parameters. In one design, the mode area can significantly increase to above 880 μm², which is comparable with that of photonic-crystal fibers. Moreover, besides the single-mode operation, the beam quality factor (M² factor) of the fundamental mode is considered an output parameter in the bent state and is improved up to 1.05 in another design. A comprehensive tolerance analysis is then performed to assess the performance of the designs under deviations from normal conditions. Moreover, in spite of the shifts in the loss of modes, the proposed high beam quality LMA fibers maintain single-polarization, single-mode operation across a wide range of core pitches, bending orientation angles, and bending radius deviations. Our results highlight the potential of multicore fibers for the efficient operation of fiber lasers and amplifiers

Cardiac Rehabilitation Using The Family-Centered Empowerment Model Versus Home-Based Cardiac Rehabilitation In Patients With Myocardial Infarction: A Randomised Controlled Trial

Objective To determine if a hybrid cardiac rehabilitation (CR) programme using the Family-Centered Empowerment Model (FCEM) as compared with standard CR will improve patient quality of life, perceived stress and state anxiety of patients with myocardial infarction (MI). Methods We conducted a randomised controlled trial in which patients received either standard home CR or CR using the FCEM strategy. Patient empowerment was measured with FCEM questionnaires preintervention and postintervention for a total of 9 assessments. Quality of life, perceived stress, and state and trait anxiety were assessed using the 36-Item Short Form Health Survey (SF-36), the 14-item Perceived Stress, and the 20-item State and 20-item Trait Anxiety questionnaires, respectively. Results 70 patients were randomised. Baseline characteristics were similar. Ejection fraction was significantly higher in the intervention group at measurements 2 (p=0.01) and 3 (p=0.001). Exercise tolerance measured as walking distance was significantly improved in the intervention group throughout the study. The quality of life results in the FCEM group showed significant improvement both within the group over time (p\u3c0.0001) and when compared with control (p\u3c0.0001). Similarly, the perceived stress and state anxiety results showed significant improvement both within the FCEM group over time (p\u3c0.0001) and when compared with control (p\u3c0.0001). No significant difference was found either within or between groups for trait anxiety. Conclusions The family-centred empowerment model may be an effective hybrid cardiac rehabilitation method for improving the physical and mental health of patients post-MI; however, further study is needed to validate these findings. Clinical Trials.gov identifier NCT02402582. Trial registration number NCT02402582

Methane emission: strategies to reduce global warming in relation to animal husbandry units with emphasis on ruminants

Concerns about global warming and greenhouse gases have increased the interest of governments and the public sector to find solutions. To reduce the effects of global warming caused by greenhouse gases, especially methane, it is necessary to change animal production systems and adopt new strategic approaches. The reduction of enteric methane in livestock is a long-standing problem regarding the energy efficiency of consumed feed. In this review, the sources of production, dissemination, and introduction of accepted scientific and practical solutions in order to reduce methane gas in breeding and production units of dairy cows have been investigated. To carry out this research, a thorough search was conducted in articles published in valid databases between 1967 and 2022. A total of 213 articles were reviewed, and after screening, 159 were included in the study and analyzed using a PRISMA flow diagram. In general, low livestock efficiency, low-quality feed, a shortage of knowledge, and inadequate investment are the main causes of emission of these gases in poor or developing countries. On the other hand, developing countries may not always have access to the same methods that are utilized in industrialized countries to minimize the production of methane and other greenhouse gases like nitrous oxide. According to their conditions, developing countries should use the available tools to reduce methane production and emission, considering the costs, local knowledge, feasibility, and local laws. In future, there will be a greater need for interdisciplinary research to look for sustainable and acceptable methods for reducing methane emissions and other greenhouse gases from animal husbandry units, especially dairy cows. To change the population of rumen methanogens, as the main producers of methane, strategies such as feeding management, addition of inhibitors and vaccination are suggested. Also, there is a need for more applied research for reducing methane emissions

The Recovery Effect of Cold Water Immersion and Massage on the Physical Performance of Young Male Soccer Players

Introduction: In recent years, reducing the time intercept between competitions and increasing the level and number of competitions, has made it one of the trainers' major concerns to adopt and employ a suitable recovery method to reduce fatigue and improve performance. The purpose of this study was to compare the effect of two recovery protocols of cold water immersion and massage on the performance of young male soccer players following an exhaustive exercise session. Methods: Thirty young male soccer players were selected as statistical samples and divided into 3 groups of 10, including cold water immersion (CWI), massage (M) and passive recovery (P). 24 hours before and after an exhaustive test of simulated soccer match (90 minutes), tests of 20 m sprint, 40 m sprint, agility, vertical jump and RSA were taken from the subjects. To analyze the findings, dependent t-test, one-way ANOVA and Tukey's post hoc test were used (p≥0.05). Results: There was no significant difference in the rate of variation in 20 m sprint and Sargent jump performances in the subjects of three groups (P≤0.05). Also, the agility of the CWI recovery group was significantly improved compared to the massage recovery group (P = 0.003). However, the repeat sprints ability in the recovery group of massage was significantly improved compared to the CWI recovery group (p = 0.01). Conclusion: Using both recovery methods of cold water immersion and massage after an exhaustive exercise session has a positive effect on the performance of young male soccer players, and if the conditions are met, then both recovery methods will probably have positive effects