PERFORMANCE ANALYSIS OF TRANSMIT POWER CONTROL SCHEME IN COGNITIVE RADIO NETWORK

Cognitive radio is a promising technology which provides efficient radio resource utilization. This paper presents a contextual literature review of the different approaches with their simulation results and identifies the one that best suits the cognitive radio environment. In recent years, a variety of transmit power control algorithms have been proposed for organizing cognitive radio networks. Firstly, we review the two transmit-power control schemes, which are specified in existing research papers, namely fixed and adaptive transmit-power control schemes. Secondly, we proposed transmit-power control schemes based on spectrum sensing side information. In order to achieve better sensing performance, we are employing more number of antennas at secondary user. Due to better sensing performance, we can exercise more accurate control on transmit power of secondary user transmitter

A study on the effect of different chemical routes on functionalization of MWCNTs by various groups (-COOH, -SO3H, -PO3H2)

Pristine multiwall carbon nanotubes [MWCNTs] have been functionalized with various groups (-COOH, -SO3H, -PO3H2) using different single- and double-step chemical routes. Various chemical treatments were given to MWCNTs using hydrochloric, nitric, phosphoric, and sulphuric acids, followed by a microwave treatment. The effect of the various chemical treatments and the dispersion using a surfactant via ultrasonication on the functionalization of MWCNTs has been studied. The results obtained have been compared with pristine MWCNTs. Scanning electron microscopy, energy dispersive X-ray [EDX] spectroscopy, and transmission electron microscopy confirm the dispersion and functionalization of MWCNTs. Their extent of functionalization with -SO3H and -PO3H2 groups from the EDX spectra has been observed to be higher for the samples functionalized with a double-step chemical route and a single-step chemical route, respectively. The ID/IG ratio calculated from Raman data shows a maximum defect concentration for the sample functionalized with the single-step chemical treatment using nitric acid. The dispersion of MWCNTs with the surfactant, Triton X-100, via ultrasonication helps in their unbundling, but the extent of functionalization mainly depends on the chemical route followed for their treatment. The functionalized carbon nanotubes can be used in proton conducting membranes for fuel cells

The Distal Basilar Artery Thrombosis Presenting as Acute Progressive Ophthalmoplegia in the Ambulatory Setting: a Neuroophthalmologic Emergency

Acute bilateral ophthalmoplegia is a well recognized sign of brainstem dysfunction. In the presence of other neurologic signs or symptoms, the diagnosis and urgency of evaluation and hospital admission is typically obvious. However, occasionally the ophthalmoplegia may be the only or predominant complaint (especially in distal basilar artery thrombosis, called the "top-of-the-basilar" syndrome)

The Relationship of Body Mass Index (BMI) and Intraocular Pressure (IOP) with the Severity of Disease in Idiopathic Intracranial Hypertension (IIH)

We hypothesized that: (a) IIH patients with a higher BMI would have higher intracranial pressure, and (b) Patients with IIH who have a higher IOP could present with greater severity of papilledema. Our clinical objectives were to assess in IIH patients, the correlation between: (a) BMI and cerebrospinal fluid (CSF) opening pressure and (b) IOP and papilledema grade (at initial presentation and diagnosis)

Horner's Syndrome Without Anisocoria: How It Can Happen

Four patients with sympathetic palsy and no miosis of the pupil demonstrated unequivocal pharmacologic evidence of Horner's syndrome. 3 patients initially had miosis but recovered and 1 patient had a larger pupil in the eye with Horner's

Extraocular Muscle Infiltration in Chronic Myeloid Leukemia

Leukemic infiltration of ocular tissue has previously been reponed in acute myeloid (AML) and lymphoid leukemia (ALL), and very rarely in chronic lymphoid leukemia (CLL). We report an unusual case of exuaoculac muscle infiltration in chronic myeloid leukemia (CML)

Airway Pressure Release Ventilation setting disagreements. A survey of clinicians

Background: Airway pressure release ventilation has been available to clinicians for the last four decades. Unfortunately, its clinical value continues to be debatable. One of the many reasons responsible is the lack of consistency between its settings in clinical practice and research. We hypothesized that clinicians disagree on specific methods when establishing these parameters. Materials and Methods: A questionnaire-based survey was developed and sent to clinicians (critical care attending physician, critical care fellows in training and respiratory therapists) in about one hundred different academic hospitals with critical care training program. The survey consisted of ten questions including each of the four major APRV settings: T-High, T-Low, P-High, and P-Low. The survey was anonymous. Main results: Amongst the 187 respondents, there were significant disagreements between different categories of clinicians regarding methodology for establishing initial settings of APRV. However, when the responses were analyzed after sub-grouping based on categories of clinicians (Critical care attending physician vs critical care fellows vs respiratory therapists), no significant differences could be found. Conclusions: There is no agreement between different categories of clinicians when it comes to the methodology for establishing initial APRV settings. Our study highlights the need for larger clinical trials comparing different approaches to the same which could then be used for establishing scientific guidelines based on best evidence

Association between Subclinical Hypothyroidism and Incident Hypertension in Women: A Systematic Review and Meta-Analysis

Subclinical hypothyroidism (SCH) has been found to be associated with an increased risk of cardiovascular diseases. However, there is no clear consensus on the relationship between SCH and hypertension (HTN). We sought to investigate the association between SCH and incident HTN in women. MEDLINE and EMBASE databases were searched for studies that reported the incidence of HTN in females with SCH versus without SCH. Pooled odds ratio (OR) and 95% confidence interval (CI) of the outcome were obtained using a random-effects model. Studies were also divided into the middle-aged (mean age < 65) and the older (mean age ≥ 65) subgroups, and a subgroup analysis was performed to examine the potential age-effect on the association between SCH and HTN. Nine studies with a total of 21,972 subjects met the inclusion criteria. SCH was found to be positively associated with HTN (OR = 1.32, 95% CI = 1.02–1.71). Such association varied depending on the age of women. In the middle-aged subgroup, SCH was more positively associated with HTN (OR = 1.64, 95% CI = 1.18–2.27), while there was no significant association in the older subgroup (OR = 0.97, 95% CI = 0.80–1.16). Our study showed that the middle-aged females with SCH had an increased risk of HTN, while there was no significant association in the older females with SCH