Spectrally Efficient Cooperative Relay Networks using Signal Space Diversity

Cooperative relaying has received widespread attention in recent years from both academic and industrial communities. It offers significant benefits in enabling connectivity as well as in increasing coverage, power saving, spatial diversity and channel capacity. However, one of the main limitations of the conventional cooperative relaying system is the repetition of the received data by the relays, which reduces the spectral efficiency and the data rate. In this thesis, signal space diversity (SSD) based technique is proposed to incorporate into the conventional relaying system to enhance spectral efficiency, data rate and system performance. Firstly, SSD is introduced into a two-way cooperative relaying system with three-phase two-way decode-and-forward (DF) protocol. In this system, four symbols are exchanged in three time slots, thereby doubling the spectral efficiency and the data rate compared to the conventional three-phase two-way DF relaying system that uses six time slots to exchange the same four symbols. Next, SSD is employed in a dual-hop relaying system using DF protocol without a direct link between the source and the destination. In this system, two symbols are transmitted in three time slots as compared to four time slots to transmit the same two symbols in the conventional dual-hop DF relaying system. These proposed systems are designed to exploit the inherent diversity in the modulation signal-space by rotating and expanding the ordinary constellation. The improvement in spectral efficiency is achieved without adding extra complexity, bandwidth or transmit power. A comprehensive analysis of these proposed systems is carried out over Rayleigh fading channels, and closed-form expressions for various performance metrics, including error probability, outage probability and channel capacity, are derived and illustrated. An asymptotic approximation for the error probability is obtained and is used to illustrate the impact of system parameters and diversity gain on the system performance. The optimization of relay location and power allocation in these systems is also examined. Extensive Monte Carlo simulations are performed to ascertain the accuracy of the analytical results presented in the thesis. Indeed, it is observed that the use of SSD in cooperative relaying can play a major role in the system design and performance improvement

Ethical Leadership and Employee Creative Performance: Discussing the mediating role of Employer Feedback Environment in Software Houses of Pakistan

Purpose: The basic purpose of this study was to explore employee creative performance, the contextual issues in the form of the leader’s style, and the feedback environment established by the leader in the Pakistani context. This study has presented a mechanism model for an understanding predictor of employee creative performance with the help of various theories. Methodology: Data was collected and analyzed from software houses registered in PSEB from 320 leader-employee dyads. Our research design was correlational. To reduce the common method biases, data was collected from two sources: leaders and their subordinates by sending the online questionnaire. To measure the uni-dimensionality and validity of construct EFA was performed through SPSS. Further, to assess the common method biases Heterotrait-Monotrait Ratio (HTMT) was used. SEM was used to compute, analyze, and prove relationships of proposed hypotheses and model fitness. CFA was used to confirm the theoretical measurement model, on AMOS 24 by using the rotated factor analysis. Finding: To sustain in this era of the competitive global business environment, organizations can stimulate employee creative performance by focusing on contextual and subjective variables. As per the findings, contextual factors like feedback environment associated with the leader regarding his style should be ethical, have a vital position in an organization for improving creative performance among employees. Specifically, the current study owns its justification and contribution to the literature and practical implications in various ways. Conclusion: The study indicates that the ethical style of leadership has a strong positive (+) association with the creative performance of employees as well as with the employer feedback environment. Also the employer feedback environment has partial mediation among ethical leadership and employee creative performance

A novel framework for collaborative intrusion detection for M2M networks

The proliferation of sensor devices has introduced exciting possibilities such as the Internet of Things (IoT). Machine to Machine (M2M) communication underpins efficient interactions within such infrastructures. The resource constraints and ad-hoc nature of these networks have significant implications for security in general and with respect to intrusion detection in particular. Consequently, contemporary solutions mandating a stable infrastructure are inadequate to fulfill these defining characteristics of M2M networks. In this paper, we present COLIDE (COLlaborative Intrusion Detection Engine) a novel framework for effective intrusion detection in the M2M networks without incurring high energy and communication cost on the participating host and edge nodes. The framework is envisioned to address challenges such as flexibility, resource constraints, and the collaborative nature of the M2M networks. The paper presents a detailed system description along with its formal and empirical evaluation using Contiki OS. Our evaluation for different communication scenarios demonstrates that the proposed approach has limited overhead in terms of energy utilization and memory consumption

Early detection of doxorubicin-induced cardiotoxicity and its prevention by carvedilol

Background: The objective was to detect doxorubicin (Dox) - induced myocardial injury at early stage by quantitative estimation of cardio specific protein, cardiac troponin I (cTnI) and to explore the cardioprotective effects of carvedilol.Methods: The study design was lab-based randomized controlled in-vivo in rabbits conducted from January to August 2012. Cardiotoxicity was produced by single intravenous injection of 12 mg/kg body weight (BW) of Dox in a group of rabbits, control group was treated with normal saline only and the rabbits of third group were pre-treated with carvedilol 30 mg/kg of BW for 10 days before injecting Dox.Results: Dox induced cardiotoxicity was depicted by markedly raised serum levels of cTnI, creatine kinase-MB, lactate dehydrogenase, and Grade 3 necrosis of the heart tissue in rabbits. The pre-treatment with carvedilol resulted in improved serum levels of these biomarkers and the histological picture of heart tissue.Conclusions: Quantitative serum estimation of cTnI detects the presence of cardiotoxicity much before cardiac dysfunctions can be revealed by any other diagnostic technique. It can lead to significant economic impact in the management of cancer patients because the troponin-negative subjects can be excluded from long-term cardiac monitoring programs that involve high costs imaging techniques. The outcome of Dox chemotherapy can be made successful with the concurrent use of carvedilol

Giant adrenal endothelial cyst associated with acute and chronic morbidity in a young female: a case report

Adrenal cysts are rare clinical entities that can present as acute abdomen through rupture and internal hemorrhage as well as chronic symptoms such as gastrointestinal disturbances. A 20-year-old girl presented to our hospital with a 4-years history of abdominal pain and diarrhea. Ultrasound of the abdomen revealed a cystic area measuring 10 × 10 cm between the spleen and left kidney. Computed tomography scan showed a large cystic, homogeneous mass measuring 12.8 × 9.5 × 9.4 cm in the left hypochondrium with most likely origin from the left adrenal gland. Limited work up for hormone hypersecretion was negative. The patient was then encountered in the emergency room with an acute abdomen secondary to intracystic hemorrhage. A laparotomy with left adrenalectomy was performed. Final pathology showed a benign adrenal endothelial cyst. Post-operatively, the patient's long standing complaints of diarrhea and abdominal pain completely resolved. Surgical resection appears a safe and reasonable management strategy in a patient with intracystic hemorrhage of adrenal cyst

Ethical Leadership and Employee Creative Performance: Discussing the mediating role of Employer Feedback Environment in Software Houses of Pakistan

Purpose: The basic purpose of this study was to explore employee creative performance, the contextual issues in the form of the leader’s style, and the feedback environment established by the leader in the Pakistani context. This study has presented a mechanism model for an understanding predictor of employee creative performance with the help of various theories. Methodology: Data was collected and analyzed from software houses registered in PSEB from 320 leader-employee dyads. Our research design was correlational. To reduce the common method biases, data was collected from two sources: leaders and their subordinates by sending the online questionnaire. To measure the uni-dimensionality and validity of construct EFA was performed through SPSS. Further, to assess the common method biases Heterotrait-Monotrait Ratio (HTMT) was used. SEM was used to compute, analyze, and prove relationships of proposed hypotheses and model fitness. CFA was used to confirm the theoretical measurement model, on AMOS 24 by using the rotated factor analysis. Finding: To sustain in this era of the competitive global business environment, organizations can stimulate employee creative performance by focusing on contextual and subjective variables. As per the findings, contextual factors like feedback environment associated with the leader regarding his style should be ethical, have a vital position in an organization for improving creative performance among employees. Specifically, the current study owns its justification and contribution to the literature and practical implications in various ways. Conclusion: The study indicates that the ethical style of leadership has a strong positive (+) association with the creative performance of employees as well as with the employer feedback environment. Also the employer feedback environment has partial mediation among ethical leadership and employee creative performance

Chiari Malformation with and without Syringomyelia: Surgical Technique and Outcome in 88 Adult Patients

Objective:  This study identified the relationship between posterior fossa craniectomy, expansion neuroplasty, and radiological appearances in patients with Chiari malformation with and without clinical syringomyelia with the surgical outcomes in an attempt to correct the lesion. Materials & Methods:  Eighty-eight patients with Chiari malformation (CM) were included in the study where 70 had associated syringomyelia. All underwent posterior fossa craniotomy, expansion duroplasty without fiddling with cerebellar tonsils. Patients were evaluated at 1 month, 3 months, and 12 months. The MRI studies were done at 12 months when symptomatic relief and radiological findings were evaluated and matched. Results:  Most of the patients were young adults between the age range of 25 – 40 years. The most common complication was pseudomeningocele (5.68%) formation followed by CSF leak (4.54%). Patients with a longer history of Chiari malformation or syrinx-related symptoms and signs had partial relief in symptoms and signs. The poor outcome as expected was seen in patients with atrophic changes in upper limbs and hypertonia in lower limbs, especially in patients with loss of joints position sense and poor balance. Patients showed maximum improvement in headaches both suboccipital as well as generalized. Syringomyelia was decreased in size in 49 patients and remained unchanged in 21.  Dysesthesias were improved in 31 patients. Conclusion:  Clinical improvement was related to the expansion of the posterior fossa and subarachnoid cistern and reduction in the size of the syrinx. Surgical decompression of the posterior fossa should create adequate space for its contents and reduce the syrinx cavity. The relationship between symptomatic improvement and radiological findings is not always linear. Keywords:  Chiari Malformation, Tonsillar Herniation, Syringomyelia, Duroplasty

Evaluation of Prognostic response in HIV positive patients after Antiretroviral Therapy

Objective: The present study was aimed to monitor the prognostic response of antiretroviral therapy in HIV positive patients. Methodology: The study was conducted on confirmed HIV positive patients registered at HIV treatment and care centre, PIMS. Islamabad from January 2013 to December 2015.. Among all HIV positive patients,276 adult cases were selected. There were 263 patients on first-line antiretroviral (ARV) therapy and 13 patients were shifted to 2nd line ARV therapy.CD4 cell counts and viral load (Polymerase chain reaction) monitoring was done after one year of starting ARV therapy. Results: Out of 276 adult patients,  75%(n=207) were male and 25%(n=69) were females. Among 276 adult cases, 95.3% (n=263) patients were on first line ARV therapy. Patients on first line ARV therapy showed good prognostic response. There  were 15.5%(n=40) patients having  CD4+cells less than 350cells/µL. There were 84.5%(n=223) patients having  CD4 +cells count greater than 350cells/µL There were 69%(n=182) patients having viral load <50copies/ml and 31%(n=81) patients who had viral load >50copies/ml. Conclusion: First line ARV therapy given to HIV positive patients proved itself best both in respect of increasing the immunity of HIV positive patients by increasing the number of CD4 cells and also results in effective viral load suppression

Genetic Analysis of Triple Pistil Wheat Derived F2 Populations to Enhance Genetic Yield Potential

Triple pistil (TP) wheat is a novel genetic resource which holds the ability to produce three grains in a single floret. In this research, TP wheat derived two F2 populations were studied to investigate genetic variability, heritability, genetic advance, genetic correlation, inheritance pattern and potential of TP trait for grain yield improvement. Phenological data were recorded for 12 morpho-agronomic traits. Most of the traits exhibited significant genetic variability (P ? 0.05) for further trait improvement. Strong positive genetic correlations (r ? 0.99 at P ? 0.01) were computed within yield contributing and yield limiting traits, indicating common genes controlling these traits and opportunity for simultaneous improvement. Inheritance analysis indicated double dominant (15:1) and double recessive (9:7) epistatic ratios in investigated populations, proposing that TP trait was controlled by two nuclear epistatic genes. In conclusion, TP wheat is a valuable germplasm resource for grain yield improvement and floral development studies