Modelling the structure of dependence of stock markets in BRICS & KENYA: Copula GARCH approach

Thesis submitted in partial fulfillment of the requirements for the Degree of Master of Science in Statistical Sciences (MSc.SS) at Strathmore UniversityBackground: Dependence structure is used widely to describe relationships between risks and provides estimation of risks for risk management purposes. Modeling dependence structure of stock returns is a difficult task when returns are having non elliptical distributions. Objective: To examine the dependence pattern between the Kenya stock market return and BRICS stock market returns. Methods: In this dissertation, we estimated the dependence using copula GARCH, an approach that combines copula functions and GARCH models. We applied this method to a stock market returns consisting of stock indices of Brazil, Russia, India, China and South Africa (BRICS) and Kenya stock market. We first used GARCH(1,1) to model the marginal distributions of each stock returns using different GARCH(1,1) specifications. Copula was then used to analyze the dependence between the BRICS stock market returns and Kenya stock market returns using the standardized marginal distributions derived from GARCH(1,1) residuals. The best fitting copula parameter was determined using the log likelihood or AIC.Results: Empirical results showed that GJR-GARCH model provided the best fit for Brazil, Russia, China and Kenya while E-GARCH model provided the best fit for India and South Africa. As for modeling the dependence structure, student t copula parameter provided the best fit for the marginal distributions of the returns. Conclusion: Marginal models showed presence of volatility clustering which vanishes after crisis. To capture the dependence structure for bi variate data sets, Student t copula was considered to be the appropriate copula function. Recommendation: Further research should be extended to examine the multivariate structure, a joint distribution of BRICS in terms of Multivariate GARCH. Also research should focus on specific time periods in order to ensure effectiveness in measurement and management of risks

Depressive Disorders among Workers in the Selected Hotels in the Capital City of Kenya: A Cross Sectional Study on Prevalence and Correlates

Background: Depressive symptoms are potential outcomes of poorly functioning and demanding work environments. Such symptoms are frequent and cause considerable suffering for the employees as well as financial loss for the employers. As a major hub of tourist attraction and the current consistent terrorism threats, workers in hotel industries in Nairobi Kenya have significant pressure not only to deliver quality services but also are faced with declining tourist flow. Accordingly, studies of psychosocial working conditions and depressive symptoms in this industry are valuable. Objective: This study measured the levels of depressive disorders and associated correlates among workers in selected luxury hotel industries in Nairobi Kenya. Methods: This cross-sectional study, consented and enrolled 360 workers in selected hotels in Nairobi. A sociodemographic based questionnaire and a mental health screening tool; Patient Health Questionnaire (PHQ-9) were used to gather information relevant to this study. The data was analyzed for central tendencies as well as for any associations and correlations. Results: The mean age of the 360 respondents was 28.4 (SD± 4.98) years. The majority 84.2% were aged 20 to 30 years, 55.3% had secondary level education, 35.3% worked as waiters. Using the PHQ-9, 9.2% had major depressive disorder while 10% were categorized as other depressive disorders. In multivariate analysis, major depressive disorders were independently associated with staying in temporary housing (OR 0.1, 95% CI 0.03 to 0.6) and those whose adult household population was between 1 to 3 persons (OR 2.7, 95% CI 1.03 to 7). The other depressive disorders were independently associated with working in low end hotels (OR 5.3, 95% CI 1.2 to 22.7); having primary education level (OR 3.9, 95% CI 1.1 to 15.9); staying in temporary houses (OR 0.3, 95% CI 0.1 to 0.8); and with monthly income of 10,000 to 50,000 KSh (100 to 500USD). The Key informant interviews identified poor remuneration, management disregard to employees input, negative attitude from work and colleagues, hostile treatment by clients, employers and colleagues, long working hours, poor diet, domestic problems, political instabilities, pressure from family members and high standards of living as some of the factors contributing to work related depression. Conclusion: Cumulatively, significantly high proportion of hotel workers suffer from depressive disorders in Nairobi. If correlates such as socio-demographic and economic, influenced by working conditions are not tackled, workers in hotel industries in Nairobi are poised to record one of the highest levels of depressive disorders in Kenya. Keywords: Depressive disorders, Workers in selected hotels, Nairobi Kenya

Lending Rates and its impact on Economic Growth in Kenya

After the liberalization of interest rates in Kenya in 1992, there has been an upward trend in the interest rates. Therefore, there is a need to investigate the factors influencing lending interest rates and their impacts on the general performance of the economy. This study examined various factors influencing lending interest rates and their impacts on the general performance of the economy. Specifically, it: investigates the effects of international interest rates on local lending interest rates in Kenya and determines the effects of budget deficit financing on lending interest rates. Annual secondary time series data spanning from 1980 to 2010 obtained from the World Bank annual reports, IMF annual reports, annual government publications and reports and other relevant publications were used. This data was parametrically analyzed using EVIEWS to present descriptive and inferential statistics. Unit roots, cointergration tests and the Error Correction Model were carried out to investigate the dynamic behavior of the model. Results of the study indicates that the impact of budget deficit and inflation on interest rates in Kenya were positive and significant. This implies that any attempt to control the rise in interest rates must pay attention to expansionary macroeconomic policies and reduce the budget deficit. Such policies should address structural and non-structural causes of inflation. For instance, it involves enacting policies to reduce the cost of doing business in Kenya. Keywords: Lending rates, Economic growth and Error Correction Mode

A review of telocytes in cardiovascular tissue and their role in angiogenesis

Telocytes are interstitial cells characterized by small cell bodies with very long and slender processes extending from them. They are present in most tissues and are most commonly found in close association with nerves, smooth muscle and microvascular networks in tissue interstitial space. Telocytes maintain tissue homeostasis in various ways including modulation of electrical activity, regulation of stem cell proliferation and angiogenesis. The role of telocytes in blood vessels stems from a structural and functional coupling to vascular endothelial and smooth muscle cells. This review explores the distribution of telocytes in cardiovascular tissues, their mechanisms in angiogenesis and application of this property in tissue regeneration. The literature search was conducted on PubMedTM, Science directTM and African Journals Online databases as well as Google ScholarTM search engines. The keywords used in the literature search included ‘telocytes’, ‘cardiovascular telocytes’, ‘blood vessel’, ‘cardiac tissue’, ‘(neo-)angiogenesis’ and ‘tissue regeneration’. Articles which contained the keywords and relevant citations from their reference lists were included in the study. In conclusion, telocytes display close structural relationship with cardiovascular tissues. They play an angiogenesis inducing role which may be explored as a therapeutic target in tissue repair and regeneration. Keywords : cardiovascular telocytes, interstitial Cajal-like cell, regeneration, angiogenesi

USPOREDNA PERFORMANSA RASTA MUŽJAKA ISTOG SPOLA I MJEŠOVITOG SPOLA NILSKE TILAPIJE (Oreochromis niloticus L.) UZGAJANIH U ZEMLJANIM RIBNJACIMA

Comparative growth performance of male monosex and mixed sex Nile tilapia (Oreochromis niloticus) was conducted in six earthen ponds each measuring 150 m2 at the Kenya Marine & Fisheries Research Institute (KMFRI), Kegati Aquaculture Research Station. Male monosex and mixed sex of O. niloticus juveniles at an average weight of 12.2 ± 0.02 g and average length of 7.6 ± 0.02 cm were collected from nursery production ponds. The male monosex juveniles were obtained by feeding newly hatched juveniles with feed dosed with 17-α-methyltestosterone hormone for a period of one month. Stocking was at 3 juvenile m-2 and feeding was carried out using 28% crude protein diet twice daily for six months at 4% body weight. Selected water quality parameters (dissolved oxygen, temperature, pH, electrical conductivity and total ammonia nitrogen) were measured weekly in situ, while sampling for weight and length measurements was conducted on a monthly basis for a period of six months. Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Condition Factor (CF) and survival rate (%) were measured at the end of six months. Data were subjected to one-way analysis of variance (ANOVA). At the end of six months, the average weight of male monosex and mixed sex fishes was 200.8 ± 0.81 g (mean ± SE) and 123.4 ± 0.76 g, respectively, while the average length of male monosex and mixed sex was 22.4 ± 0.21 cm and 18.6 ± 0.23 cm, respectively. The male monosex O. niloticus achieved significantly increased final weight and length, SGR, FCR and CF than the mixed sex O. niloticus (p 0.05). There were no significant differences in mean water quality parameters in male monosex and mixed sex ponds (p > 0.05). The male monosex fish performed better because most energy was spent on muscle and tissue development while the mixed sex fish spent most energy on reproduction activities at the expense of muscle and tissue development. Further studies should be done in other culture systems such as liner ponds, tanks, cages and raceways.Usporedna performansa rasta mužjaka istog spola u odnosu na mješoviti spol Nilske tilapije (Oreochromis niloticus) provedena je u šest zemljanih ribnjaka veličine 150 m2 u Kenijskom institutu za istraživanje mora i ribarstva (KMFRI), Akvakulturna stanica u Kegatiju. Nedozrele jedinke mužjaka istog spola i mješovitog spola O. niloticus prosječne mase 12,2 ± 0,02 g i prosječne dužine 7,6 ± 0,02 cm prikupljene su iz mladičnjaka. Nedozrele jedinke mužjaka su dobivene hranjenjem novoizleglih ličinaka s hranom doziranom hormonom 17 α-metil-testosteronom u razdoblju od mjesec dana. Nasad je proveden u gustoći od 3 mladunca / m2 i hranidbom od 28% sirovih proteina dva puta dnevno tijekom šest mjeseci na 4% tjelesne težine. Odabrani fizikalno-kemijski parametri vode (otopljen kisik, temperatura, provodljivost i ukupni amonijak) mjereni su tjedno in situ, dok su izmjere dužina i masa provedene na mjesečnoj bazi tijekom 6 mjeseci. Specifična stopa rasta (SGR), omjer konverzije hrane (FCR), kondicijski faktor (CF) i stopa preživljavanja (%) izmjereni su na kraju perioda od šest mjeseci. Podaci su analizirani jednosmjernom analizom varijance (ANOVA). Na kraju promatranog perioda od 6 mjeseci, prosječna težina mužjaka istog spola iznosila je 200,8 ± 0,81 g (prosjek ± standardna devijacija) i mješovitog spola 123,4 ± 0,76 g, a prosječna dužina mužjaka istog spola iznosila je 22,4 ± 0,21 cm i mješovitog spola 18,6 ± 0,23 cm. Mužjaci istog spola O. niloticus postigli su značajno veću konačnu težinu i dužinu, SGR, FCR i CF nego mješoviti spol (p 0,05). Nije zabilježena značajna razlika u kvaliteti mjerenih parametara u vodi ribnjaka promatranih skupina riba (p > 0,05). Mužjaci istog spola imaju bolje rezultate jer je većina energije potrošena na mišiće i razvoj tkiva, dok je mješoviti spol trošio najviše energije na reprodukcijske aktivnosti na račun mišića i razvoj tkiva. Daljnja istraživanja bi trebala biti usmjerena ka drugim sustavima uzgoja poput obloženih ribnjaka, zatvorenih bazena, kaveza i protočnih kanala

Immunogenicity of the RTS,S/AS01 Malaria Vaccine and\ud Implications for Duration of Vaccine Efficacy: Secondary\ud Analysis of Data from a Phase 3 Randomised Controlled Trial

The RTS,S/AS01 malaria vaccine targets the circumsporozoite protein, inducing antibodies associated with the prevention of Plasmodium falciparum infection. We assessed the association between anti-circumsporozoite antibody titres and the magnitude and duration of vaccine effi cacy using data from a phase 3 trial done between 2009 and 2014. Using data from 8922 African children aged 5 1317 months and 6537 African infants aged 6 1312 weeks at first vaccination, we analysed the determinants of immunogenicity after RTS,S/AS01 vaccination with or without a booster dose. We assessed the association between the incidence of clinical malaria and anti-circumsporozoite antibody titres using a model of anti-circumsporozoite antibody dynamics and the natural acquisition of protective immunity over time. RTS,S/AS01-induced anti-circumsporozoite antibody titres were greater in children aged 5 1317 months than in those aged 6 1312 weeks. Pre-vaccination anti-circumsporozoite titres were associated with lower immunogenicity in children aged 6 1312 weeks and higher immunogenicity in those aged 5 1317 months. The immunogenicity of the booster dose was strongly associated with immunogenicity after primary vaccination. Anti-circumsporozoite titres wane according to a biphasic exponential distribution. In participants aged 5 1317 months, the half-life of the shortlived component of the antibody response was 45 days (95% credible interval 42 1348) and that of the long-lived component was 591 days (557 13632). After primary vaccination 12% (11 1313) of the response was estimated to be longlived, rising to 30% (28 1332%) after a booster dose. An anti-circumsporozoite antibody titre of 121 EU/mL (98 13153) was estimated to prevent 50% of infections. Waning anti-circumsporozoite antibody titres predict the duration of effi cacy against clinical malaria across diff erent age categories and transmission intensities, and effi cacy wanes more rapidly at higher transmission intensity Anti-circumsporozoite antibody titres are a surrogate of protection for the magnitude and duration of RTS,S/AS01 effi cacy, with or without a booster dose, providing a valuable surrogate of eff ectiveness for new RTS,S formulations in the age groups considered

Immunogenicity of the RTS,S/AS01 malaria vaccine and implications for duration of vaccine efficacy:Secondary analysis of data from a phase 3 randomised controlled trial

BACKGROUND: The RTS,S/AS01 malaria vaccine targets the circumsporozoite protein, inducing antibodies associated with the prevention of Plasmodium falciparum infection. We assessed the association between anti-circumsporozoite antibody titres and the magnitude and duration of vaccine efficacy using data from a phase 3 trial done between 2009 and 2014. METHODS: Using data from 8922 African children aged 5-17 months and 6537 African infants aged 6-12 weeks at first vaccination, we analysed the determinants of immunogenicity after RTS,S/AS01 vaccination with or without a booster dose. We assessed the association between the incidence of clinical malaria and anti-circumsporozoite antibody titres using a model of anti-circumsporozoite antibody dynamics and the natural acquisition of protective immunity over time. FINDINGS: RTS,S/AS01-induced anti-circumsporozoite antibody titres were greater in children aged 5-17 months than in those aged 6-12 weeks. Pre-vaccination anti-circumsporozoite titres were associated with lower immunogenicity in children aged 6-12 weeks and higher immunogenicity in those aged 5-17 months. The immunogenicity of the booster dose was strongly associated with immunogenicity after primary vaccination. Anti-circumsporozoite titres wane according to a biphasic exponential distribution. In participants aged 5-17 months, the half-life of the short-lived component of the antibody response was 45 days (95% credible interval 42-48) and that of the long-lived component was 591 days (557-632). After primary vaccination 12% (11-13) of the response was estimated to be long-lived, rising to 30% (28-32%) after a booster dose. An anti-circumsporozoite antibody titre of 121 EU/mL (98-153) was estimated to prevent 50% of infections. Waning anti-circumsporozoite antibody titres predict the duration of efficacy against clinical malaria across different age categories and transmission intensities, and efficacy wanes more rapidly at higher transmission intensity. INTERPRETATION: Anti-circumsporozoite antibody titres are a surrogate of protection for the magnitude and duration of RTS,S/AS01 efficacy, with or without a booster dose, providing a valuable surrogate of effectiveness for new RTS,S formulations in the age groups considered. FUNDING: UK Medical Research Council

Community based weighing of newborns and use of mobile phones by village elders in rural settings in Kenya: a decentralised approach to health care provision

<p>Abstract</p> <p>Background</p> <p>Identifying every pregnancy, regardless of home or health facility delivery, is crucial to accurately estimating maternal and neonatal mortality. Furthermore, obtaining birth weights and other anthropometric measurements in rural settings in resource limited countries is a difficult challenge. Unfortunately for the majority of infants born outside of a health care facility, pregnancies are often not recorded and birth weights are not accurately known. Data from the initial 6 months of the Maternal and Neonatal Health (MNH) Registry Study of the Global Network for Women and Children's Health study area in Kenya revealed that up to 70% of newborns did not have exact weights measured and recorded by the end of the first week of life; nearly all of these infants were born outside health facilities.</p> <p>Methods</p> <p>To more completely obtain accurate birth weights for all infants, regardless of delivery site, village elders were engaged to assist in case finding for pregnancies and births. All elders were provided with weighing scales and mobile phones as tools to assist in subject enrollment and data recording. Subjects were instructed to bring the newborn infant to the home of the elder as soon as possible after birth for weight measurement.</p> <p>The proportion of pregnancies identified before delivery and the proportion of births with weights measured were compared before and after provision of weighing scales and mobile phones to village elders. Primary outcomes were the percent of infants with a measured birth weight (recorded within 7 days of birth) and the percent of women enrolled before delivery.</p> <p>Results</p> <p>The recorded birth weight increased from 43 ± 5.7% to 97 ± 1.1. The birth weight distributions between infants born and weighed in a health facility and those born at home and weighed by village elders were similar. In addition, a significant increase in the percent of subjects enrolled before delivery was found.</p> <p>Conclusions</p> <p>Pregnancy case finding and acquisition of birth weight information can be successfully shifted to the community level.</p

Triple-Antiretroviral Prophylaxis to Prevent Mother-To-Child HIV Transmission through Breastfeeding—The Kisumu Breastfeeding Study, Kenya: A Clinical Trial

Timothy Thomas and colleagues report the results of the Kisumu breastfeeding study (Kenya), a single-arm trial that assessed the feasibility and safety of a triple-antiretroviral regimen to suppress maternal HIV load in late pregnancy

Epidemiology of COVID-19 infections on routine polymerase chain reaction (PCR) and serology testing in Coastal Kenya [version 1; peer review: 2 approved]

Background: There are limited studies in Africa describing the epidemiology, clinical characteristics and serostatus of individuals tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We tested routine samples from the Coastal part of Kenya between 17th March 2020 and 30th June 2021. Methods: SARS-CoV-2 infections identified using reverse transcription polymerase chain reaction (RT-PCR) and clinical surveillance data at the point of sample collection were used to classify as either symptomatic or asymptomatic. IgG antibodies were measured in sera samples, using a well validated in-house enzyme-linked immunosorbent assay (ELISA). Results: Mombasa accounted for 56.2% of all the 99,694 naso-pharyngeal/oro-pharyngeal swabs tested, and males constituted the majority tested (73.4%). A total of 7737 (7.7%) individuals were SARS-CoV-2 positive by RT-PCR. The majority (i.e., 92.4%) of the RT-PCR positive individuals were asymptomatic. Testing was dominated by mass screening and travellers, and even at health facility level 91.6% of tests were from individuals without symptoms. Out of the 97,124 tests from asymptomatic individuals 7,149 (7%) were positive and of the 2,568 symptomatic individuals 588 (23%) were positive. In total, 2458 serum samples were submitted with paired naso-pharyngeal/oro-pharyngeal samples and 45% of the RT-PCR positive samples and 20% of the RT-PCR negative samples were paired with positive serum samples. Symptomatic individuals had significantly higher antibody levels than asymptomatic individuals and become RT-PCR negative on repeat testing earlier than asymptomatic individuals. Conclusions: In conclusion, the majority of SARS-CoV-2 infections identified by routine testing in Coastal Kenya were asymptomatic. This reflects the testing practice of health services in Kenya, but also implies that asymptomatic infection is very common in the population. Symptomatic infection may be less common, or it may be that individuals do not present for testing when they have symptoms