Analysis of RSVP-TE graceful restart

GMPLS is viewed as an attractive intelligent control plane for different network technologies and graceful restart is a key technique in ensuring this control plane is resilient and able to recover adequately from faults. This paper analyses the graceful restart mechanism proposed for a key GMPLS protocol, RSVP-TE. A novel analytical model, which may be readily adapted to study other protocols, is developed. This model allows the efficacy of graceful restart to be evaluated in a number of scenarios. It is found that, unsurprisingly, increasing control message loss and increasing the number of data plane connections both increased the time to complete recovery. It was also discovered that a threshold exists beyond which a relatively small change in the control message loss probability causes a disproportionately large increase in the time to complete recovery. The interesting findings in this work suggest that the performance of graceful restart is worthy of further investigation, with emphasis being placed on exploring procedures to optimise the performance of graceful restart

Ophthalmic disorders among students of School for the Deaf

Aim: This study aimed at determining the prevalence and pattern of ophthalmic disorders amongstudents of School for the Deaf, Akure, Ondo State, Nigeria.Methodology: This is a cross sectional descriptive study was conducted in October, 2011 aspart of activities marking the Annual Physicians’ week of Nigerian Medical Association (NMA),Ondo State. Ethical clearance was obtained from the Ethical Review Committee of FederalMedical Centre, Owo prior to commencement of this study. The permission of the SchoolAuthority was also obtained before the commencement of this study. The respondents wereselected by simple random sampling technique. All enrolled participants were interviewed withthe aid of the study instrument (questionnaire) by the authors and interpreters (school teachers).Results: The respondents comprised of 91(56.9%) Males and 69 Females (43.1%). Nearly all therespondents;158(98.8%) were deaf and dumb. Most respondents; 116(72.5%) had ocularexamination in the past. Few respondents; 118(73.75%) had ophthalmic disorder. The commonest ophthalmic disorder was refractive error which was found in 16 respondents(38.1%). Myopia was diagnosed in 9 respondents.CONCLUSION: Most of the respondents were deaf and dumb. Few respondents hadophthalmic disorder. The commonest ophthalmic disorder was refractive error. Myopia was themost predominant refractive error. There is need for periodic ocular screening and treatment atthe School for the Deaf.

Designing a multi-hop regular virtual topology for ultrafast optical packet switching : node placement optimisation and/or dilation minimisation?

This paper studies the design of multi-hop regular virtual topologies to facilitate optical packet switching in networks with arbitrary physical topologies. The inputs to the virtual topology design problem are the physical topology, the traffic matrix and the regular topology. In this paper, this problem is tackled directly and also by decomposition into two sub-problems. The first sub-problem, dilation minimisation, uses only the physical topology and the virtual topology as optimisation inputs. The second sub-problem considers the traffic matrix and virtual topology as optimisation inputs. The solutions of these two sub-problems are compared with each other and against the results obtained when the global problem is optimised (using all three possible input parameters) for a variety of traffic scenarios. This gives insight into the key question of whether the physical topology or the traffic matrix is the more important parameter when designing a regular virtual topology for optical packet switching. Regardless of the approach taken the problem is intractable and hence heuristics must be used to find (near) optimal solutions in reasonable time. Five different optimisation heuristics, using different artificial intelligence techniques, are employed in this paper. The results obtained by the heuristics for the three alternative design approaches are compared under a variety of traffic scenarios. An important conclusion of this paper is that the traffic matrix plays a less significant role than is conventionally assumed, and only a marginal penalty is incurred by disregarding it in several of the traffic cases considered

The Homotopy Analysis of Unsteady Hydromagnetic Flow of a Viscous Fluid with Oscillatory Suction Velocity

This work considered the unsteady hydromagnetic flow of an electrically conducting, incompressible, viscous fluid past an infinite vertical porous plate. The oscillatory suction velocity is normal to the plate. The uniform magnetic field influence is normal to the flow and the permeability of the medium is time dependent. The oscillatory suction velocity was defined so as to eliminate any complexity in the equations that were derived. The problem was solved using a modified technique of the Homotopy analysis method. The results obtained were discussed for various effects of material parameters on the velocity, temperature and concentration profiles.Keywords: Heat transfer, Mass transfer, Oscillatory suction velocity, Hydromagnetic flow, Vertical porous plat

RSVP performance optimisation using multi-objective evolutionary optimisation

The proposed uses of the resource reservation protocol (RSVP) now extend beyond reserving resources in Internet Protocol (IP) networks to being a generic signaling protocol for generalised multi-protocol label switching (GMPLS). In any implementation of RSVP, there are a number of discretionary timing parameters, the values of which affect the efficacy of RSVP in establishing and maintaining reservations/connections. This work frames the interactions between key RSVP timing parameters and performance metrics as a multi-objective optimisation problem which, due to its intractable nature, is tackled using a reputable multi-objective evolutionary algorithm. It is shown that this approach is a feasible means of exploring many of the innate tradeoffs in soft-state protocols such as RSVP. This approach facilitates an extensive comparison of a number of variants of RSVP: standard RSVP, RSVP featuring the recently standardised retransmission algorithm and two subsequent variants of this algorithm, supporting the asymmetric delivery of RSVP control messages. These RSVP variants are compared in terms of multiple performance metrics under a number of different exemplar network conditions, giving insight into their relative merits. Furthermore, the relative significance of the different timing parameters is investigated and their most expedient values determined

Women's perspectives on epilepsy and its sociocultural impact in south western Nigeria

Background There has been little study of the specific implications of living with epilepsy for women in societies where they already face gender based marginalization. Purpose Understanding the sociocultural aspects of epilepsy in women will help to improve the management of epilepsy in the community. Methods A series of six focus groups were held in urban and rural Southwest Nigeria.Results Epilepsy was commonly attributed to a spiritual attack, witchcraft and other supernatural causes. Denial of the diagnosis of epilepsy was common among women with nocturnal or focal seizures. Majority of women with epilepsy preferred multiple modalities of care in the following order: traditional, spiritual and western. The cost of traditional care was astronomical and most were already impoverished by the time they sought western care. WWE experienced stigma, social exclusion, isolation particularly from paternal relations, in -laws, and community members. Epilepsy related stigma contributed to schooling problems, difficulty in getting married, separation, divorce and problems with childcare and role fulfilment. One unanticipated result of this study was that public announcements made to identify rural study participants created a demand for western health services in rural populations previously unaware that epilepsy could be controlled through western medication.Conclusion Women with epilepsy face significant and persistent social, economic and cultural barriers. There is the need to educate women, their family and community members to reduce misconceptions and stigma. Community based medical treatment can be improved by taking into consideration the surrounding social, economic and cultural challenges faced by women with epilepsy. The care of epilepsy need to be incorporated into the primary health care system; regular awareness campaigns to be carried out in order to improve knowledge and attitudes and reduce stigma and social exclusion of women with epilepsy. Specific social welfare programmes and educational programme should be established to encourage the full integration of women with epilepsy in the society

Schistosomiasis presenting as acute appendicitus

No Abstract.The East African Medical Journal Vol. 83 (10) 2006: pp. 528-53

Incidence of Bacterial Septicaemia in Ile-Ife Metropolis, Nigeria

A retrospective study of septicaemia was conducted in Ile-Ife metropolis with a view to determine its incidence and changes in the predominant aetiological agents. Six hundred and fifty (650) subjects, aged from one day to seventy years and above were examined. They all had clinical features suggestive of septicaemia and were on admission at the Obafemi Awolowo University hospital Complex, Ile-Ife, Nigeria. Their blood specimens were seeded into thioglycolate and glucose broths and incubated at 37 °C for 7 days. Subcultures were performed after 1, 2, 3, 4 and 7 days respectively. Growth (positivity) in the broths was assessed using conventional diagnostic methods namely macroscopy (visualization), Gram filming (microscopy) and culture. The bacterial isolates harvested were subjected to in-vitro antibiotic susceptibility tests using the disc diffusion method. Etiology was established in 204 out of 650 subjects indicating an incidence of 31.4%. This difference in prevalence among different age groups was statistically significant (P < 0.01). The males (112/650, 17.2%) appeared to be more susceptible to septicaemia than the females (94/650, 14.5%) in all the age groups. This variation had no statistical significance (P > 0.01). Monomicrobial septicaemia had a higher prevalence (92.2%) than polymicrobial septicaemia (7.8%). Staphylococcus aureus and Escherichia coli constituted 43.8%. Most of the offensive microbes were facultative anaerobes (91.7%) while very few were strict aerobes (6.8%) and strict anaerobes (1.5%). The isolated anaerobes were Peptostreptococcus sp. (0.5%) and Bacteroides fragilis (1%). The in vitro susceptibility of the bacterial isolates to antibiotics indicated 76.4-95.6% sensitivity to vancomycin, zinnat, peflacin and fortum. However, they were 60 – 90% resistant to penicillin, ampicillin, tetracycline and septrin. This study confirmed the diverse nature of bacterial etiologies of septicaemia in the area; the need for the use of thioglycolate broths, first subcultures on or before 24 h instead of starting off for after 48 h of incubation, complementary application of macroscopy, Gram filming and culture including antibiotic susceptibility test as an integral part of diagnosis and management of septicaemia is hereby advocated, most especially in the developing countries of the world

Dynamic Performance Analysis of Cogeneration Potential in Photovoltaic Power System.

The solar cell junction is susceptible to performance degradation, due to internal temperature rise which is further perturbed by ambient temperature rise. The conversion efficiency of the solar module remarkably drops because of temperature rise. The diurnal module temperature hovers above 60 degrees C. It is possible to keep the conversion efficiency high by water-cooled or air blast equipment. This project is a preliminary study of the impact of temperature variation across seasons on the dynamic performance of photovoltaic power system. The photovoltaic (PV) module was mounted on a test rig at latitude 7 degree on top of physics building Obafemi Awolowo University campus. The output voltage of the PV module was applied to a resistive load and system efficiency performance measured over a period of time covering the dry and rainy seasons. Measurements of ambient temperature, PV junction operating temperature, wind speed, solar irradiance, and power delivered were carried out. A numerical algorithm was developed to analyse the data. The transport medium can store heat energy from the solar module, so that a large amount of hot water can be produced. The results show that this thermal transfer benefit, positions the PV system in good stead, for Microgrid: Cogeneration Energy Efficiency functionality. Keywords: Conversion efficiency, Photovoltaic power system, PV module, Water-cooled equipment, Cogeneration

Demographic and clinical profile of patients with juvenile onset open angle glaucoma in southwestern Nigeria

Background: This was a non-comparative, retrospective review of patients diagnosed with juvenile open angle glaucoma (JOAG) in the eye clinic of a tertiary hospital in southwestern Nigeria.Objective: To document the demographic characteristics, clinical features and treatment outcome of the patients diagnosed with JOAG.Materials and Methods: Data were extracted from the clinical record of patients diagnosed with JOAG in the eye clinic of the University College Hospital, Ibadan, Nigeria, between January 2001 and December 2005. Such data included the basic demographic data, the clinical characteristic of the patients and the outcome of their treatment.Results: Twenty-nine patients were reviewed, which represents 3.4% of all newly diagnosed glaucoma patients seen in the out-patient section of the eye clinic of the University College Hospital, Ibadan, over the period reviewed. Eight (27.6%) patients were aged 20 years and below. The mean age was 25.1 &plusmn; SD 6.0 years. Eighteen (62.1%) had visual acuity of 6/18 or worse in the better eye at the time of presentation. The mean intraocular pressure (IOP) of the patients at presentation was 32.3 &plusmn; SD 15.2 mmHg. Eight (27.6%) patients defaulted within 6 months of presentation. The mean IOP for the 21 patients who were followed up on treatment for a mean period of 9.6 months was 17.0 &plusmn; SD 6.0 mmHg.Conclusion: Most patients with JOAG in this review presented with advanced form of the disease. Early detection through parent-driven school eye health program and community-based case detection could help in reducing the scourge arising from JOAG among our population