Spectrum leasing in cognitive radio networks: a survey

Cognitive Radio (CR) is a dynamic spectrum access approach, in which unlicensed users (or secondary users, SUs) exploit the underutilized channels (or white spaces) owned by the licensed users (or primary users, PUs). Traditionally, SUs are oblivious to PUs, and therefore the acquisition of white spaces is not guaranteed. Hence, a SU must vacate its channel whenever a PU reappears on it in an unpredictablemanner,which may affect the SUs’ network performance. Spectrumleasing has been proposed to tackle the aforementioned problem through negotiation between the PU and SU networks, which allows the SUs to acquire white spaces for a guaranteed period of time.Through spectrumleasing, the PUs and SUs enhance their network performances, and additionally PUs maximize their respective monetary gains. Numerous research efforts have been made to investigate the CR, whereas the research into spectrum leasing remains at its infancy. In this paper, we present a comprehensive review on spectrum leasing schemes in CR networks by highlighting some pioneering approaches and discuss the gains, functionalities, characteristics, and challenges of spectrum leasing schemes along with the performance enhancement in CR networks. Additionally, we discuss various open issues in order to spark new interests in this research area

Role of the Dual-State Model of Creative Cognition for Evaluating Creativity in English Language Classrooms at the Primary Level

This study is an attempt to measure creativity in English-language classrooms through the dual-state model of creative cognition. Creativity may be assessed in Pakistani English-language classrooms because it is usually hindered in schools at the primary level. The model used was the dual-state model of creative cognition, i.e., generative and non-generative stages. The outline of the model proposes that individuals may benefit from both stages, but at individual stages, they benefit from one stage rather than both stages. Two abilities were tested. There is the ability to think logically and analytically, as well as make associations. The tests used were the Remote Associate Test (RAT) and the Torrance Test of Creative Thinking (TTCT verbal part). The RAT test consisted of 30 items. A few items were selected from an online source, and a few were made manually. The TTCT test consists of nine statements to get feedback about teaching and learning practices. The tests were processed through statistical measures. The students were enrolled in a private school in Faisalabad. The sample of the study was class 7th and 8th of Al-Faisal Grammar High School, Faisalabad. The results proved the hypothesis correct: the model suggests that students would get more benefit from one stage than from two

Spectrum of Diseases in Patients with Non-Traumatic Acute Abdomen.

Introduction: Acute Abdomen is the most common presenting complaints about 20% of all emergency department, due to its varied etiology it poses significant diagnostic challenges for emergency surgeons. The proper management of patients with acute abdominal pain requires a timely decision about the need for surgical operation. Objective: To identify the spectrum of diseases in patients of non-traumatic leading to Acute abdomen, presenting in a surgical unit. Methodology: During Jan 2012 to Dec 2014, this retrospective study conducted at Surgical Department of Muhammad Medical College, all patients presenting with non-traumatic acute abdominal pain were included in this study. Gynecological and urological causes were excluded. The patient diagnosis and management were recorded from the case files and OT registers. Results: During the period, a total of 216 patients presented with non-traumatic acute abdomen; of which there were 145 (67.12%) males and 71 (32.87%) females, with a male to female ratio of 2:1. The highest incidence of acute abdomen 72 (33.33%) was found in patients of 22-32 years age group followed by under 21 years age group i.e. 51 (23.61%) and 33-42 years age group 43 (19.90%). There were 31 (14.35%) cases in 43-52 years and 19 (8.79%) cases in 53-70 years. The most common cause of acute abdomen was acute appendicitis 105 (48.61%) admissions. These patients were mostly young males in twenties. Intestinal obstruction was second cause 45 (20.83%) cases and this affected more commonly the middle-aged persons. Two hundred and seven (95.83 %) patients were treated successfully and discharged home while 5 (2.31 %) left against medical advice, while 4 expired giving a mortality of (1.85) % in patients with gut perforation Conclusion: The most common cause of acute abdomen is acute appendicitis affecting young population mostly. Another common cause is intestinal obstruction and gut perforation. Acute cholecystitis commonly affects the middle aged, post-menopausal women. Hepatic abscess and Pancreatitis are rare cause of acute abdomen in this area. Key Words:  Acute abdomen. Non-traumatic Acute appendicitis, Intestinal obstruction

The Relationship Between Nurse Attitude and Students Self-Efficacy in Nursing Students Perceptive

Background: Clinical education is the methods by which nursing students are offered chances to apply the theories and learning of nursing, and work on nursing abilities that are basic to practice as a proficient staff nurse. For the competent clinical self efficacy, a caring relationship is necessary and essential for student learning in clinical setting. According to a study the clinical learning environment and supervision impact on clinical competency of nursing students.  There is significant impact of supervisory relationship on clinical experience of students. The relationship between clinical faculty and nurse teacher also has impact in clinical self efficacy of the nursing student.Method: a descriptive co relational study design used in this study. The study conducted in The University of Lahore on 117 students of Nursing. The sample size calculated through Solvens formula. Clinical learning environment supervision and Nurse Teacher evaluation scale (CLES+T) and nursing clinical self efficacy scale (NCSES) questionnaire used in study. Results: there is positive correlation between clinical learning environment and self efficacy of students. The overall co relational value is r=.336, p=.000 at the level of 0.01.Conclusion: It is concluded that the attitude of clinical staff has great impact on student clinical self efficacy. The creation a good clinical environment the clinical self efficacy of the student can be enhanced Keywords: Relationship, Attitude, Clinical Self Efficacy, Nursing students, Perception DOI: 10.7176/JHMN/62-02 Publication date:May 31st 201

Prevalence of anxiety and depression among Medical Students in MMCH, Sindh, Pakistan

Introduction: Medical education is stressful. High levels of stress have been seen in medical students in various studies. The academic stressors include the volume of material to be learned, academic performance and evaluation, examination and continuous assessment, mental tension and too much work load. All this can result in decreased life satisfaction among students.  Stress during medical school can lead to problems later in professional life compromising patient care. Objectives: To know the prevalence of anxiety and depression among medical students of Muhammad Medical College, Mirpurkhas, Sindh, Pakistan  Methodology: A Cross-sectional study was done on the students of Muhammad Medical College, Mirpurkhas, Sindh, who had spent more than six months in the medical college. Self-administered questionnaire was given to the students, present in the class and willing to participate in the study. The instrument used to assess the anxiety and depression levels was the, Aga Khan University Anxiety and Depression Scale (AKUADS). Additional quotations regarding socioeconomic variables were also included in them survey instrument, such as student’s age order, family monthly income, and gender, marital status. Results: Using anxiety and depression scale it was found out that 318 (96.36%) students had anxiety and depression. Among them 215 (67.61%) were females and 103 (32.38%) males. Prevalence of anxiety and depression in students of Final, 4th year and 3rd year 2nd and 1st years was 13%, 15%, 20% and 21%, 28% respectively. It was significantly higher in 1st year and 2nd year students, as compared to final and 4th year and students. Conclusions: Most of medical students have anxiety and depression due to study burden and a busy schedule. It is also seen that anxiety and depression is more among female medical students, and more among in 1st year and 2nd year MBBS students, as compared to the final and forth year students.   Keywords: Anxiety, depression, Medical students, prevalenc

A Descriptive Tolerance Nearness Measure for Performing Graph Comparison

Accepted versionThis article proposes the tolerance nearness measure (TNM) as a computationally reduced alternative to the graph edit distance (GED) for performing graph comparisons. The TNM is defined within the context of near set theory, where the central idea is that determining similarity between sets of disjoint objects is at once intuitive and practically applicable. The TNM between two graphs is produced using the Bron-Kerbosh maximal clique enumeration algorithm. The result is that the TNM approach is less computationally complex than the bipartite-based GED algorithm. The contribution of this paper is the application of TNM to the problem of quantifying the similarity of disjoint graphs and that the maximal clique enumeration-based TNM produces comparable results to the GED when applied to the problem of content-based image processing, which becomes important as the number of nodes in a graph increases."This research was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant 418413."https://content.iospress.com/articles/fundamenta-informaticae/fi174

Vitamin D accelerates clinical recovery from tuberculosis: results of the SUCCINCT Study [Supplementary Cholecalciferol in recovery from tuberculosis]. A randomized, placebo-controlled, clinical trial of vitamin D supplementation in patients with pulmonary tuberculosis\u27.

BACKGROUND: Vitamin D enhances host protective immune responses to Mycobacterium tuberculosis by suppressing Interferon-gamma (IFN-g) and reducing disease associated inflammation in the host. The objectives of this study were to determine whether vitamin Dsupplementation to patients with tuberculosis (TB) could influence recovery. METHODS: Two hundred and fifty nine patients with pulmonary TB were randomized to receive either 600,000 IU of Intramuscular vitamin D3 or placebo for 2 doses. Assessments were performed at 4, 8 and 12 weeks. Early secreted and T cell activated 6 kDa (ESAT6) and Mycobacterium tuberculosis sonicate (MTBs) antigen induced whole blood stimulated IFN-g responses were measured at 0 and 12 weeks. Statistical comparisons between outcome variables at 0 and 12 weeks were performed using Student\u27s t-test and Chi2 tests. RESULTS: After 12 weeks, the vitamin D supplemented arm demonstrated significantly greater mean weight gain (kg)+3.75, (3.16-4.34) versus+2.61 (95% CI 1.99-3.23) p 0.009 and lesser residual disease by chest radiograph; number of zones involved 1.35 v/s 1.82 p 0.004 (95% CI 0.15, 0.79) and 50% or greater reduction in cavity size 106 (89.8%) v/s 111 (94.8%), p 0.035. Vitamin D supplementation led to significant increase in MTBs-induced IFN-g secretion in patients with baseline \u27Deficient\u27 25-hydroxyvitamin D serum levels (p 0.021). CONCLUSIONS: Supplementation with high doses of vitamin D accelerated clinical, radiographic improvement in all TB patients and increased host immune activation in patients with baseline \u27Deficient\u27 serum vitamin D levels. These results suggest a therapeutic role for vitamin D in the treatment of TB