Design techniques and implementations of high-speed analog communication circuits: two analog-to-digital converters and a 3.125Gb/s receiver

Low-cost and high performance analog building blocks are essentials to the realization of today\u27s high-speed networking and communications systems. Two such building blocks are analog-to-digital converters (ADCs) and multi-gigabit per second transceivers. This thesis addresses two different ADC architectures and a 3.125Gb/s receiver Architecture;The first ADC architecture is a 10-bit, 100MS/s pipeline ADC. Techniques that enhance the gain-bandwidth of the operational amplifier, a key building block in analog-to-digital converters, as well as to increase its do gain are presented. Layout techniques to reduce the effect of parasitics on the performance of the ADC are also discussed. Since any ADC will have inherent errors in it, two calibration techniques that reduce the effect of these errors on the performance of the ADC are also presented.;For the second ADC, a new architecture is proposed that is capable of achieving higher performance than many current ADC architectures. The new architecture is based on a voltage controlled oscillator and a frequency detector. One reason for the high performance of the new ADC is the novel architecture of the frequency detector. This thesis includes detailed analysis as well as examples to illustrate the operation of the frequency detector.;Designing high-speed CMOS transceivers is a challenging process, especially, when using digital CMOS process that exhibits poor analog performance. Circuit implementation and design techniques that are used to design and enhance the performance of the receiver block of a 3.125Gb/s transceiver in a 0.18u digital CMOS process are presented and fully explained in this thesis. Silicon results have shown that these techniques have resulted in outstanding and very robust receiver performance under different operating conditions

Preparation and Characterization of Copper-Doped and Silver-Doped Titanium Dioxide Nano-Catalysts for Photocatalytic Applications

The goal of this work was to improve the performance of TiO2 nanomaterials by increasing their optical activities by shifting the onset of the response from the UV to the visible-light region. Among the several ways to achieve this goal, doping TiO2 nanomaterials with other elements (e.g. metals) was selected to narrow the band gap and enhance the optical properties of TiO2 nanomaterials. In this work, we have prepared Cu-doped TiO2 nano-catalysts, characterized them and studied their properties, and the optical ones in particular. The Ag-doped TiO2 catalyst was prepared by the sol-gel method while the Cu-doped TiO2 catalyst was prepared by using two different techniques for comparison purposes: the sol-gel method and the inert gas condensation technique under ultra-high vacuum. The Ag-doped TiO2 nano-catalysts prepared by the sol-gel method were characterized by using Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM) and Electron Probe Micro-Analyzer (EPMA) for surface morphology and chemical composition, Brunauer-Emmett-Teller (BET) analysis for surface area and porosity measurements, x-ray diffraction (XRD) to determine their crystal structure and UV-visible absorption spectrometry (UV-Vis) to measure the optical properties. The same characterization methods have been applied on the Cu-doped TiO2 photocatalysts prepared by the sol-gel method, in addition to some rheological measurements to determine their flow behavior. Furthermore, x-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and UV-visible absorption spectrometry (UV-Vis) analyses have been conducted to characterize the Cu-doped TiO2 catalyst prepared by inert gases condensation technique. The experimental work conducted here revealed promising results for improving the performance of the TiO2 nanomaterial by doping it with Cu and Ag metals where the optical was enhanced and shifted to the visible region causing an appreciable increase in its effectiveness for photocatalytic application

Effect of Sources of Organic Manure on Growth and Yields of Okra (Abelmoschus esculentus L.) in Sokoto, Nigeria

Field experiments to investigate the effect of different sources of organic manure (Cow, Sheep and Poultry Manure) on growth and yield of okra was carried out at the Teaching and Research Fadama Farm of Usmanu Danfodiyo University Sokoto, Nigeria during 2007/2008 and 2008/2009 dry seasons. Treatments were laid out in a randomized complete block design (RCBD) with three replications. Data were collected on growth and yield parameters (Plant height, number of leaves per plant, pod length and fresh pod weight). Results obtained indicated that growth and yield of okra was lowest in control treatments which showed that the organic manures used in the study especially poultry manure positively influenced the performance and yield of okra. Poultry manure positively increased okra plant height by 39.4% and number of leaves by 37.8% compared to control treatments. There was no significant effect with respect to number of leaves in 2007/2008. Fresh pod weight was significantly increased by 34.6% with poultry manure compared to control treatments. However, pod length was not significantly affected by the treatments. Based on the findings of the experiments it could be deduced that poultry manure seems to promote higher growth and yield of okra. Thus, it should berecommended for farmers growing okra in this zone.Keywords: Okra, Growth, Yield, Source, Organic Manur

Pattern of irritable bowel syndrome and its impact on quality of life in primary health care center attendees, Suez governorate, Egypt

Introduction: Irritable bowel syndrome (IBS) is one of the most common disorders diagnosed by gastroenterologists and a common cause of general practice visits. Although this disease is not life threatening, patients with IBS seem to be seriously affected in their everyday life. The study was designed to explore the pattern of IBS in clinical practice and the impact on the quality of life. Methods: This is a case control descriptive study. 117 individuals were included in this study. Rome II criteria were used for the diagnosis of IBS. Impact of IBS on patient's quality of life was determined by irritable bowel syndrome quality of life (IBS-QOL) questionnaire. Results: Prevalence of IBS among the study sample was 34.2%. 10% were IBS-Diarrhea, 37.5% were IBS-Constipation and 52.5% were alternators. There is statistical insignificant relationship between IBS (+) and age while it was a significant relation regarding gender (more common among women 80%). There is statistical significance relationship between IBS (+) on one hand and marital status and occupational status on the other hand. Patients with IBS had statistically significant lower scores for all IBS- QOL domains compared with the control group. Conclusion: IBS is a prevalent disorder that affects females more than males and it has significant impacts on work, lifestyle and social well-being.Key words: Irritable bowel syndrome, quality of life, Roma I

Socio-Economic Determinants of Insecticides Usage in Cowpea Production in Kaduna State, Nigeria

This study investigates the socio-economic determinants of Insecticides use among cowpea farmers in Kaduna State, Nigeria. A multi-stage sampling technique was used to select 150 cowpea farmers who used insecticides in controlling pest in cowpea production in the study area. Information collected includes those of socio-economic characteristics of the famers and the quantity of insecticides they used. A regression model was used to estimate the relationship between farmers’ socio-economic characteristics and the insecticides use level. The study showed that family size, farm size level of education and years of farming experience were the major socio-economic determinants of insecticides use level among the cowpea farmers in the studied area. It was recommended that training and efforts to get farmers educated are intensified while strategies that will prevent migration of educated youths away from active areas of farming be put in place.Keywords: Cowpea, farmers, socio-economic, determinant, insecticidesJournal of Agriculture and Social Research (JASR) Vol. 11, No. 1, 201

Prevalence of cardiovascular-related comorbidity in ankylosing spondylitis, psoriatic arthritis and psoriasis in primary care: a matched retrospective cohort study

The aim of this study is to compare the prevalence of cardiovascular (CVD)-related comorbidities in patients with ankylosing spondylitis (AS), psoriatic arthritis (PsA) or psoriasis (Ps) in UK primary care against matched cohorts. Matched retrospective cohort study used a primary care consultation database. Three cohorts were constructed using all patients with a Read code diagnosis of AS, PsA or Ps between 1999 and 2009; each cohort was then compared in a 1:4 ratio to a matched cohort. The prevalence of CVD-related comorbidities (hypertension, ischaemic heart disease, hyperlipidaemia and diabetes mellitus) were identified by the first consultation of a comorbid Read code, in those with an inflammatory condition of interest. The prevalence of CVD-related comorbidities was compared between each inflammatory cohort and their matched cohort using Fisher’s exact test. Ninety-four AS, 106 PsA and 290 Ps patients were identified. Compared with matched cohorts, the most prevalent CVD-related comorbidity in patients with AS was hypertension (35 (37.2 %) vs. 96 matched (25.5 %), p = 0.03); this was also the case for PsA (41 (38.7 %) vs. 114 matched (26.9 %), p = 0.02). No differences were seen in the prevalence of other CVD-related comorbidities in those with AS, PsA or Ps compared to their matched cohorts. Our findings provide UK comparisons of CVD-related comorbidities in patients with AS, PsA and Ps alone; specifically, demonstrating increased prevalence of hypertension in AS and PsA cohorts compared to their matched cohorts. This further supports the argument for more evidence in the need for screening and intervention around CVD comorbidities in inflammatory conditions

Evaluation of acute toxicity and anti-inflammatory effects of Baccharoides schimperi (DC.) in experimental animals

Background: Steroidal and non-steroidal anti-inflammatory drugs are most commonly used to treat inflammation, and shown to have severe side effects. In this study, we aimed at evaluating the anti-inflammatory and acute toxicity effects of Baccharoides schimperi (DC.) in order to get new anti-inflammatory agents of natural origin.Materials and methods: The aerial part of the plant was dried under shade, ground and extracted with 96% alcohol (BSE). It was further fractionated in sequence to n-hexane (BSH), chloroform (BSC) and methanol (BSM) soluble fractions. Acute toxicity was evaluated by oral administration of plant and hind paw induced-edema method in rats was used for the anti-inflammatory evaluation.Results: The BSE was found safe up to the dose level of 3 g/kg b.w. and showed LD50 value 7.250 g/kg body weight (b.w.) in mice. BSE showed significant anti-inflammatory effect (62.91%) at 500 mg/kg b.w. Further the n-hexane, chloroform and methanol fractions of BSE were tested for antiinflammatory activity. The n-hexane fraction (BSH) exhibits significant activity (64.87%) at 400 mg/kg b.w. The methanol fraction (BSM) showed dose dependent activity, highest activity (60.42%) was observed at higher  dose 400 of mg/kg b.w. In chloroform fraction (BSC) no significant activitywas observed.Conclusion: The results of the study revealed that the plant is safe to the experimental model and recommended as a potential source of antiinflammatory agent.Key words: Acute toxicity, anti-inflammatory activity, Baccharoide schimperi (DC.

Progranulin in frontotemporal lobar degeneration and neuroinflammation

Progranulin (PGRN) is a pleiotropic protein that has gained the attention of the neuroscience community with recent discoveries of mutations in the gene for PGRN that cause frontotemporal lobar degeneration (FTLD). Pathogenic mutations in PGRN result in null alleles, and the disease is likely the result of haploinsufficiency. Little is known about the normal function of PGRN in the central nervous system apart from a role in brain development. It is expressed by microglia and neurons. In the periphery, PGRN is involved in wound repair and inflammation. High PGRN expression has been associated with more aggressive growth of various tumors. The properties of full length PGRN are distinct from those of proteolytically derived peptides, referred to as granulins (GRNs). While PGRN has trophic properties, GRNs are more akin to inflammatory mediators such as cytokines. Loss of the neurotrophic properties of PGRN may play a role in selective neuronal degeneration in FTLD, but neuroinflammation may also be important. Gene expression studies suggest that PGRN is up-regulated in a variety of neuroinflammatory conditions, and increased PGRN expression by microglia may play a pivotal role in the response to brain injury, neuroinflammation and neurodegeneration

Impact of spinal anesthesia on cesarean section outcome in Omdurman maternity hospital - Sudan 2011

Background: The cesarean section is indicated when vaginal delivery is not safe for the mother or the baby.Objective: A descriptive study done in Omdurman maternity hospital–OMH to assess the impact of spinal anesthesia (SA) on cesarean section(C/S), including, intra and post operative maternal complications, neonatal outcome and patients’ satisfaction in 2011.Methodology: Women delivered by C/S under SA were included in the study after an informed consent. All women in the study were operated on by trained registrars or obstetricians, under SA given, either by anesthetist or assistant anesthetist under supervision with similar conditions andwere followed till discharge from hospital.Results: Total number of deliveries at OMH in 2011 were 30397, 21677 (71.3%) delivered vaginally, 8720 (28.7%) delivered by C/S, only 24 women (0.3%) delivered under general anaethesia- GA. Women included in the study were 1029, 517 (50.2%) were elective and 512 (49.8%) were emergency C/S. Intra- operatively, 79 women (7.7%) developed hypotension, their BP dropped by more than 30 mmHg, four women developed severe shivering for which they received intravenous 25 mg pethedine, and 44 neonates received oxygen by mask and only oneneeded endotranchial intubation. Post operatively, only two women had disabling headache, 24 women (2.4%) had episodes of vomiting and 199 (19.3%) had pain in their lower limbs, buttock and thigh, it disappeared completely before discharge. In this study, 880 women (85.5%) weresatisfied with SA, while 149 (14.5%) were not satisfied due to pain at the time of puncture, headache, or transient lower limb pain after operation.Conclusion:Spinal anesthesia is increasingly used for C/S in this hospital, with excellent patients’ satisfaction, without increase in maternal and neonatal mortality or morbidity.Key words: spinal anesthesia, Cesarean section, Suda

Cracking in asphalt materials

This chapter provides a comprehensive review of both laboratory characterization and modelling of bulk material fracture in asphalt mixtures. For the purpose of organization, this chapter is divided into a section on laboratory tests and a section on models. The laboratory characterization section is further subdivided on the basis of predominant loading conditions (monotonic vs. cyclic). The section on constitutive models is subdivided into two sections, the first one containing fracture mechanics based models for crack initiation and propagation that do not include material degradation due to cyclic loading conditions. The second section discusses phenomenological models that have been developed for crack growth through the use of dissipated energy and damage accumulation concepts. These latter models have the capability to simulate degradation of material capacity upon exceeding a threshold number of loading cycles.Peer ReviewedPostprint (author's final draft