Optical fiber transmission systems for in-door next generation broadband access network.

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.This thesis investigates the generation and radio-over-fibre (RoF) transport of unlicensed 60 GHz millimetre-wave (mm-wave) frequency band. The investigated benefits of transmission schemes applicable for the mm-wave generation include optical carrier suppression (OCS), optical frequency multiplication (OFM) and remote heterodyne detection (RHD). For the in-door cabling of the mm-wave transmission, a low-cost polymer optical fibre (POF) along with bend-insensitive single mode fibre (BI-SMF) has been investigated for short-range networks. Transporting mm-wave generated signals over POF and BI-SMF cables based on OCS scheme showed results with the highest spectral efficiency and least inter-symbol interference over a 2.5 Gbit/s data delivery. Based on this thesis analysis, OCS simulation of POF showed the most reliable power penalty performance and receiver sensitivity at 30-m whilst the BI-SMF fiber produced equal observations at 150-m and more. In observing the free space links of delivering the RoF signal, the attenuation on the received signal power for both POF and BI-SMF was insignificant but expected, as the simulation assumed complete and total collimation of the light beams onto the aperture of the photodetector. OCS scheme for mm-wave generation and transport was explored based on the cost effectiveness of using one external modulator compared to other generation schemes that utilised more than one external modulator. OFM scheme was simulated to transport LTE and Wi-Fi signals along with 60 GHz RF band through both SMF and MMF-POF/BI-SMF cables. OFM transport scheme produced the highest attenuation on LTE, Wi-Fi and mm-wave signals carrying 100 Mbit/s data as simulated POF lengths increased. The best performance POF length was observed at 10-m. The application of offset launch technique at the coupling of SMF and POF showed insignificant improvement on signal bandwidth. The free space OFM transmission also demonstrated negligible change to the received signal power. This reinforces the attributes of deploying OWC system in an in-door environment. In other investigation, the simulated successful delivery of mm-wave signal using RHD scheme modulated and transported 10 Gbit/s data signal over POF and BI-SMF cables. Additional observed unrecorded result also showed BI-SMF cable maintained a 2% reduction of received power for 450-m fiber cable from 150-m. The attributes to RHD includes its low operating power system application and delivery of localised 60 GHz signal for uplink RoF transmission. The conceptualised design of Gigabit data delivery for indoor customer applications either through POF or BI-SMF cable, transporting various wireless channels has been presented in this thesis for the design of a robust next generation Broadband access network to reinforce the fiber-inside-the-home (FiTH) deployment

Prevalence of antibodies to Hepatitis C virus among Nigerian patients with HIV infection

Nigeria belongs to the group of countries highly endemic for viral hepatitis; unfortunately information on the prevalence of hepatitis C amongst patients with HIV in Nigeria is very scarce. This hospital-based investigation was conducted at two major hospitals in Jos, Nigeria from June 2002 through May 2003. Serum samples from 490 confirmed HIV infected patients were assayed for the presence of antibodies to HCV, using a third generation enzyme linked immunosorbent assay. Twenty eight (5.7%; 95% CI 3.66-7.76%) of the patients had antibodies to HCV. The prevalence of HCV antibodies was higher among the males (7.5%; 95% CI 3.83-11.09%) than the females (4.5%; 95% CI 2.10-6.88%). Statistical analysis showed no significant difference (x2 = 1.917, df =1, p=0.05). Individuals of the age group 41-50 years had the highest prevalence of HCV antibodies (15.4%; 95% CI. 7.37-23.29%), followed by those of age group 31-40 years (7.4%; 95%, CI 3.70-11.20%). A significant difference was observed in the association between age and prevalence of HCV antibodies (x2 = 24.151, df = 4, p =0.05). Early diagnosis of HCV in people with HIV infection is advocated to reduce risk of HCV related advanced liver disease

EFFECT OF OUTSOURCING ON EMPLOYMENT RELATIONS IN NIGERIA: A STUDY OF SHELL PETROLEUM PRODUCING AND DEVELOPMENT COMPANY

This study investigates the effect of outsourcing practice on employment relations in Multinational Corporations with special focus on Shell Petroleum Producing and Development Company (SPDC). The study also examined the importance of employment relations in organizational performance. Descriptive research methodology was adopted in this study. The questionnaire that was administered in the field survey was the abbreviated version of Hewitt’s Human Resource Outsourcing Survey Questionnaire. The research findings showed that: the management of SPDC engages in unfair labour practices in order to trivialize workers conditions of service; mere transferring human resource management to a third party does not necessarily improve labour-management relations; outsourcing affects workers’ performance in Nigeria; there is positive relationship between employment relations and organisational performance. Based on the research findings, it recommends that the management of SPDC must discontinue its unfair labour practices; should improve the working conditions of its contract staff and show more interest in their career development; should focus attention on fostering mutual employment relations by ensuring that all its human resource policies are not counter-productive especially its outsourcing policy. JEL: L20; L23; L53 Article visualizations

Multivariate Rank Discriminant Classifier of Small Sample

This article studied discriminant analysis procedure that is based on multivariate ranking with emphasis on Spatial or L1 depth classifier using Eviews and SPSS computer packages. The performance of the classifier is assessed using both simulated and real life data. The result of the study revealed that the classifier is optimal in classifying observations into one of the two pre-defined groups

From Prejudice to Preference: the Case of Traditional Medicine in Nsukka, Nigeria, 1960-2014

This study attempts to explain why Phyto-medicine referred to as Ogwu Igbo has remained relevant in the health care delivery system of Nsukka Igbo despite its derision following the advent of Western medicine. Nsukka people have had a rich tradition of herbal medicine for their health challenges but much has not been researched, a gap this intends to fill. Primary and secondary data such as journals, books, interviews and Ad-Hoc observations and accounts were analysed qualitatively using historical and self-report technique which revealed the people were depending on traditional medicine increasingly due to several factors. It submits that economic hardships and the efficacy of traditional medicine have promoted its acceptance

Review of core stability exercise versus conventional exercise in the management of chronic low back pain

Exercise has been proven to be effective in the management of chronic low back pain. Over the years, core stability exercise (CSE) has gained popularity however there is lack of consensus on the best exercise treatment. Aims: To review the effectiveness of core stability exercises or conventional exercises in the management of chronic low back pain (CLBP). Methods: This study is a systematic review of randomized clinical trials which examined studies regarding core stability and conventional exercise by using Google scholar, Medline, PEDro and Cochrane from 2010 to 2021. The Methodological quality was evaluated using the PEDro scale. The included studies randomized participants into two different exercise groups. Results: From the 58 potentially relevant trials, a total of 14 trials were included in the current analysis. The data indicated that core stability exercise was better than conventional exercise for short term pain relief. Ten studies included self reported back specific functional status, and compared to conventional exercise, core stability exercise resulted in significant improvement in function. Conclusion: Compared to conventional exercise, core stability exercise is more effective in pain reduction and improved physical function in individuals with CLBP in the short term however, only two trials carried out follow-up assessments post intervention. Keywords: Core stability exercise; conventional exercise; chronic low back pain

Učinak nigerijske Qua Iboe Brent sirove nafte na slezenu i hematološke pokazatelje u štakora

This study investigated the consequences of exposure to crude oil on components of the immune system of male rats. A total of 40 male albino rats were used for the experiment. Exposure to crude oil was achieved by oral administration of increasing doses (low, medium and high) of Nigerian Qua Iboe Brent crude oil to the rats every other day for 4 weeks. Haematological parameters, relative weights and histomorphological features of the spleen of rats that received the crude oil were compared to control rats. The results showed that packed cell volume values (P<0.05), erythrocyte counts (P<0.05), absolute neutrophil counts (P<0.01) and absolute monocyte counts (P<0.01) were significantly reduced in crude oil-exposed rats. The total leukocyte counts (P<0.05) and absolute lymphocyte counts (P<0.01) were increased at the low dose of crude oil, but were subsequently reduced with increase in dose of crude oil. Splenic morphology was severely altered in rats that consumed crude oil. These findings suggest that exposure to Nigerian Qua Iboe Brent crude oil adversely affected the immune system of male rats. This implies possible immunosuppression for humans and other species exposed to this environmental pollutant.Istraživanje je provedeno da bi se ustanovio učinak sirove nafte na imunosni sustav štakora. U pokus je bilo uzeto ukupno 40 mužjaka albino štakora. U razdoblju od četiri tjedna svi su štakori peroralno dobivali sirovu naftu Nigerian Qua Iboe Brent na način da im je svaki drugi dan povećavana doza (od najmanje preko srednje do najveće). Uspoređeni su hematološki pokazatelji, relativne mase i histomorfološka obilježja slezena pokusnih i kontrolnih štakora. Ustanovljene su smanjene vrijednosti ukupnoga obujma krvnih stanica (P<0,05), broja eritrocita (P<0,05), apsolutnoga broja neutrofila (P<0,01) i apsolutnoga broja monocita (P<0,01) u štakora izloženih sirovoj nafti. Ukupan broj leukocita (P<0,05) i apsolutni broj limfocita (P<0,01) bio je povećan tijekom razdoblja u kojem su štakori dobivali male doze sirove nafte, ali je bio smanjen s povećanjem doze. Morfologija slezene ozbiljno je bila poremećena u štakora koji su dobivali sirovu naftu. Nalazi upućuju na zaključak da izlaganje nigerijskoj Qua Iboe Brent sirovoj nafti nepovoljno utječe na imunosni sustav štakora. To ukazuje i na mogući imunosupresijski učinak na čovjeka i druge vrste izložene ovom zagađivaču okoliša

HYPOGLYCAEMIC AND HAEMATINIC PROPERTIES OF ETHANOL LEAF EXTRACT OF ARTOCARPUS HETEROPHYLLUS IN ALLOXAN INDUCED DIABETIC RATS.

Background: Anaemia is known to be associated with diabetes; moreover, with the increasing cases of diabetes there is need for the use of more affordable alternative herbal medicines for the treatment of diabetes and anaemia. The aim of this work was to evaluate the hypoglycaemic and haematinic properties of Artocarpus heteropyllus on diabetic rats. Materials and Methods: Ethanol leaf extract of Artocarpus heteropyllus was screened for phytochemicals and its acute toxicity was tested on mice. Induction of diabetes was done at a dose of 150 mg/kg body weight (b.w) (with exception of the control group). The extract was administered to rats for a period of 7 days at 100, 300 and 500 mg/kg b.w, respectively, following induction. Blood samples of rats were tested for fasting blood sugar (FBS), packed cell volume (PCV), white blood cell (WBC), red blood cell (RBC), haemoglobin, neutrophil lymphocyte and eosinophil counts. Results: The ethanol leaf extract of A. heterophyllus showed no mortality up to a dose of 5000 mg/kg b.w. Administration of the extract to diabetic rats resulted in a decrease in the FBS of diabetic rat, and significant increases (p< 0.05) in RBC, PCV, WBC and haemoglobin levels. Conclusion: The ethanol leaf extract of A. heterophyllus increased the haematological indices of diabetic rats. Our findings support the use of this plant as an herbal alternative in the treatment of diabetes and anaemia associated diabetes

The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics