156 Records out of 22207 Records

Fertility models based on mixtures and compound distributions

Author: Nyaga, John Gatumu

Awarding University: University of Nairobi, Kenya

Level : MSc

Year: 2012

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Fertility ; Models ; Statistical methods ;

Abstract:

A considerable amount of work has been done regarding the fertility study in mathematical demography. Most researchers used Beta distribution since it a classic example of a distributions in the [0,1] domain. This project is prepared with the intention of reviewing some probability models generated through mixed and Compound distributions by different researchers, considering other distributions in the [0,1] as mixing distribution, as well as modifying some the distributions for applications to specific populations.

Male involvement in the management of infertile couples at Kenyatta National Hospital

Author: Ondieki, Diana Kerubo

Awarding University: University of Nairobi, Kenya

Level : MMed

Year: 2012

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Infertility ; Men ; Reproductive health ;

Abstract:

Infertility remains a global health challenge with devastating psychosocial consequences in many African communities. It is estimated that 50-80 million people worldwide are afflicted by infertility. The global prevalence is 8-12%, but this is higher in African countries ( 20:- 30%).2 In Kenya, upto 31% of the consultations made at KNH and MTRH (the two national referral hospitals) are related to infertility? The distribution of causes of infertility among infertile couples has male factor accounting for 23% and unexplained causes 28%.4 In a WHO multicentre study, male factor was found to contribute 20% and both male and female to contribute 27%.5 From the above statistics it is clear that male factor contributes significantly to the burden of disease, yet clinical and research work is concentrated on the female,' Failure to target men has weakened the impact of reproductive health programmes.? From literature review, there is minimal information on male involvement in the management of infertile couples. Study Design A hospital based cross-sectional descriptive study that involved couples presenting to the KNH Infertilility and Gynaecology clinics. Broad objective To determine the extent, predictors and impact of male involvement in -the management of infertile couples at the Kenyatta National Hospital. Main outcome measures The proportion of males involved in the management of infertile couples at the Kenyatta National Hospital. Results A total of 163 women and 34 men were recruited into the study. At least 69.9%(114) of the women who participated were ever accompanied to the clinic by their spouses. Knowledge on infertility among male participants was generally low especially whed it came to matters that concerned their spouses. Couple awareness on male participation in infertility was 61.8% by the men and 67.5% by the women but they all agreed that it would improve the care given. The male partners who came to the clinic were more involved in the care of their partners, in terms of paying hospital bills, having investigations performed on them, participating in the decision making process and accepting treatment (p<0.05). On multiple logistic regression, it was found that male partners of accompanied women were paying the medical bills (p-value = 0.017, OR=3.0[1.2-7.4]), being investigated (p-value=O.O 11 , OR=3. 1 [1.3-7.5]), helping decide the treatment the partner receives (p-value = 0.04, OR=2.5[1.0-5.9]) and accepting treatment if found to have a problem (p-value=0.005, OR=4.0[1.5-10.5]). Men with male factor infertility were more likely to accompany the spouse to the clinic if there was an associated female factor infertility, p=0.002. There was no statistical significance between accompanied and unaccompanied women in terms of education and employment. Majority of the male participants (55.9%) had received pressure from the community to ~et children. Conclusion Male partner participation improved the quality of care. There is need to address the negative pressure from family and community about a couple's childlessness. Recommendations Health care providers should offer appropriate counseling for the male partners and educate the community on infertility. In light of our findings, further research should be done on ways to improve male partner attendance and participation in the infertility clinic.

Land use change and intensification : impacts on soil macrofauna with emphasis on Earthworms in land use mosaics in Embu and Taita-Taveta Districts, Kenya

Author: Musombi, Kibberenge B J

Awarding University: University of Nairobi, Kenya

Level : PhD

Year: 2012

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Land use ; Soil fertility ; Maize ; Embu District ; Taita-Taveta District ; Dirofilaria immitis ;

Abstract:

The study set out to determine, characterize and compare geomorphologic, physiographic land use types and agroecosystem intensification, assess physicochemical nature of soil at benchmark study sites of Embu and Taita Kenya. Then determine macrofauna occurrence, abundance and diversity along a land use intensification chronosequence and explore their relations with soil characteristics, and impacts of land use and agricultural intensification on diversity and abundance of soil macrofauna. Then finally determine effects of soil fertility amendments on earthworms in a maize based agroecosystem. Specific stages within of study included site characterization, stratified sampling of macrofauna and estimation their abundance, biomass and diversity in land use mosaics subjected to varying degrees of anthropogenic intensification and determination of within and between land use mosaic macrofauna diversity. The study synthesized and appraised importance of macrofauna in soil structure stability and quality, soil organic matter translocations, decomposition and inorganic soil components. Findings from this study provide baseline data and information on use of macrofauna in evaluating potential consequences of anthropogenic management practices as global change drivers of ecosystem processes responsible for loss or maintenance of soil productivity. Key words: Macrofauna biodiversity, Earthworms, Geomorphology, Physiography, Land use, Soil fertility, Soil degradation, Agricultural intensification, Kenya

Factors influencing fertility preferences of currently married men in Kenya

Author: Mashara, Janet Naisoi

Awarding University: University of Nairobi, Kenya

Level : MA

Year: 2012

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Fertility ; Births ; Couples ; Men ; Population growth ; Families and family life ;

Abstract:

In recent decades fertility has declined at a rapid pace in a majority of developing countries including Kenya. Kenya's population size has grown from 5.4 million in 1948 to 38.6 million in 2009 with the total fertility rate ranging between 4.9 in 2003 and 4.6 in 2008/9 revealing a stall in fertility. Studies have shown that fertility preference can be useful as an indicator of the direction that future fertility may take. Studies have also documented a significant effect of men's preference in regard to the family matters which may eclipse women's preference for the family decision-making. Understanding the fertility preference of married men in Kenya is of paramount importance given the effect it has on future fertility when the preferences are implemented. It is also important to family planning programmes because it helps determine the need for contraception, whether for spacing or limiting births, and the extent of unwanted and mistimed pregnancies. The main objective of this study was to determine the factors that influence fertility preference of currently married men in Kenya. The specific objectives were: to establish the effects of socio-demographic factors on fertility preference of currently married men in Kenya; to establish the effect of socio-economic factors on fertility preference of currently married men in Kenya; and to establish the effects of socio- cultural factors on fertility preference of currently married men in Kenya. The data was obtained from a sample size of 1,757 married men aged 15-54 years who were asked questions on various topics including fertility preference and more specifically their desire to have additional children during the 2008/9 Kenya Demographic and Health Survey. Pullum (1980) conceptual framework was employed in study. The dependent variable was desire for ad?i~ional children which was dichotomized as 1 'desire' and 0 'Non-desire' whereas the study variables were age, number of living children, education, place of residence, wealth index, region, occupation, type of marriage and number of living sons. From the descriptive analysis, the results revealed that about 57 percent of currently married men in Kenya are likely to desire additional children. The results also showed that, age, number of living children, education, place of residence, wealth index, region, occupation, type of marriage and number of living sons were all significantly associated with the desire for additional children. The results of multivariate analysis indicated that age, number of living children, education, region, occupation, type of marriage and number of living sons were significant factors associated with the desire for additional children at 0.001,0.01 and 0.05 significance level. This study recommends that education for men should be emphasized because education was discovered to have a highly significant effect on the fertility preference. Promotion of information that creates awareness on the value of children irrespective of sex should be focused upon so as to minimize son preference. Policies that aim at integrating population into development should be encouraged so as to foster socio-economic development in all the regions and hence minimize the regional disparities as it relates to fertility preferences. In terms of research, further studies, both qualitative and quantitative, to be carried out in order to explore the socio-cultural and religious beliefs, norms and attitudes of men in regards to the value of children.

Determinants of fertility in Kenya : a comparative study of Nyanza and Central provinces

Author: Yogo, Kennedy Obuya

Awarding University: University of Nairobi, Kenya

Level : MA

Year: 2011

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Nyanza Province/Central Province/Fertility/Population/Socioeconomic factors ;

Abstract:

This project examines the determinants of fertility in Nyanza and Central provinces of Kenya. The study specifically examines the effects of demographic, socio-economic and socio-cultural factors on children ever born to answer the question: what are the determinants of fertility in Nyanza and Central provinces of Kenya? Data from the 2008-09 Kenya Demographic and Health Survey (2008-09 KDHS) of 1,318 and 973 women aged 15- 49 from Nyanza and Central provinces respectively were used. The study is premised on John Bongaarts' (1978) framework for analyzing proximate determinants of fertility. The main methods of analysis used include descriptive statistics, simple bivariate and multivariate linear regression analyses. The Statistical Package for Social Science (SPSS 17 for windows) software was used to analyze the data. Results of multivariate analysis established that all the demographic/ intermediate variables included in the study are significant determinants of children ever born (CEB) in Nyanza province. In Central province, on the other hand, and to our surprise, ever use of contraceptive is not significantly related to children ever born when other variables are controlled for. With regard to the socio-economic factors, wealth index is the only statistically significant determinant of children ever born in Central province when the effects of all the other variables are held constant. However, in Nyanza province, education, wealth index and place of residence are significantly related to children ever born in Nyanza province when other variables are held constant. Women's work status as an indicator of socio-economic variable is not a significant determinant of children ever born in the two regions. Finally in the category of the socio-cultural factors, results show that type of marriage (the only socio-cultural factor studied) is a significant determinant of children ever born in Central province, whereas it is not a significant determinant of children ever born in Nyanza province. The study recommends that concerted efforts should be put on expanding family planning and child health programmes, specifically to reduce fertility as well as infant and maternal mortality and consequently maintain and enhance the overall well-being of the family. The study further recommends increased opportunities for girl child education.

Enhancing communication for effective dissemination of soil fertility management in the Central Highlands of Kenya

Author: Kimaru, Wairimu Serah

Awarding University: Kenyatta University, Kenya

Level : MES

Year: 2011

Holding Libraries: Kenyatta University Moi Library ;

Subject Terms: Central Highlands, Kenya/Soils/Fertility/Agricultural extension work ;

Abstract:

Increased recognition of soil fertility depletion as the main biophysical factor limiting crop production in many African small holder farms has renewed interest in the dissemination of soil fertility management (SFM) practices. Despite soil technology development and research outputs, few of the recommendations from soil fertility management research have been put into use by the targeted end users. Accessibility and utilization of the existing knowledge is inadequate due to the communication methods and tools used in dissemination and up scaling of soil fertility management practices. With this background, this study was set out with the following objectives; i) to investigate availability and reliability of sources on SFM for farmers, ii) to identify communication channels used by researchers and extension agents and iii) to determine socio- economic factors that influence preference of communication methods by farmers, in the Central highlands of Kenya. Questionnaires were used to collect information from 22 researchers and 105 extension workers. In order to determine the socio-economic factors influencing farmers' preferences of communication methods, individual household interviews were conducted where 240 randomly selected farmers were interviewed. Data was analyzed using descriptive statistics (frequency, mean, percentages and Chi-square). Spearman correlation coefficient and logistic regressions were used to test the magnitude of the relationship between dependent and independent variables using statistical package for social sciences (SPSS) programme. Results showed that farmers perceived other farmers as the most available and reliable source of information on SFM while radio were perceived as highly available but relatively unreliable by farmers. Demonstration, farmer 'to farmer extension and workshops/seminar were sequentially ranked as the first three methods preferred by the farmers. Majority of the researchers and extension officers frequently used field days and demonstration as methods of communicating to farmers on soil fertility management. Preference of demonstration by farmers in training on green manure was positively influenced by age (r=0.158, P=0.05) and number of non formal trainings (r=0.114, P=0.05) but negatively influenced by farm size (r=-0.132, P=0.05) and gender (r=-0.184, P=O.OI). Gender, education, number of non formal trainings attended, farm size and number of times a farmer had been visited by an extension agent were significant predictors in preference of field days in training on animal manure. Continued use of demonstration method was recommended as it was highly preferred by the farmers as well as considered effective by the extension agents and researchers. For effective dissemination of SFM, agricultural stakeholders should consider farmers' socio-economic characteristics while designing extension intervention strategies to be used in dissemination of soil fertility management practices. This is envisaged to increase adoption of SFM practices which will consequently lead to increased crop production and contribute to reduction of extreme poverty.

Management options addressing soil fertility decline and weed infestation in smallholder maize production systems of Western?Kenkya

Author: Ngome, Ajebesone Francis

Awarding University: University of Bonn, Germany

Level : PhD

Year: 2011

Holding Libraries: ;

Subject Terms: Soil fertility ; Weeds ; Maize ; Western Kenya ; Management ;

Abstract:

ABSTRACT NOT AVAILABLE

Variation of soil fertility indicators in Wundanyi Division, Taita District, Kenya

Author: Mbora, Moses Owiti

Awarding University: Kenyatta University, Kenya

Level : MSc

Year: 2011

Holding Libraries: Kenyatta University Moi Library ;

Subject Terms: Wundanyi Division, Taita District ; Soils ; Fertility ;

Abstract:

The greater Taita community lives in crowded parcels of land that are intensely used to generate household food and family income. Wundanyi division which is the district headquarters is divided into Upper, Medium and Lower zones and has a high population density of 92 persons per Km2? Each household is estimated to generate 95 % of economic income from agriculture. High population, overdependence on agriculture and low income can have adverse effects on soil fertility. The objectives of this study were to determine the levels of local indicators of soil fertility including soil color, ease of tillage, cracks, stoniness, water retention, application of farm inputs, vigour of growth of farm plants, common weeds, farmland and family size, crop yield and adequacy by use of a questionnaire; levels of scientific soil fertility indicators including soil texture, soil organic carbon, pH, total nitrogen, phosphorus and potassium; and their variations across the Upper, Medium and Lower zones of Wundanyi division. Using objective guided sampling, 30 households from the Upper and Medium and 21 from Lower zones were used to determine the percent respondents and variation of local indicators of soil fertility. Ten households from each zone were then involved in farmland soil sampling at 20 em depth for use in determination of scientific soil fertility indicators. Soil texture was determined by hydrometer method, pH determined by pH meter, organic carbon and phosphorus by colorimetry and potassium by flame photometry. The study established according to percent respondents, that farmlands in the Upper zone had close proportions of grey and redlbrown soils, Medium zone had grey soils while the Lower zone had redlbrown soils; the soils were highly friable; had water retaining capacity for one week; many farmers applied manure and fertilizer; vigour of plant growth average; soil fertility moderate; farm yield average and farm produce inadequate. The soil color (p < 0.05), ease 'of tillage (p < 0.05), water retention (p < 0.05), use of farm inputs (p < 0.05), perceived soil fertility (p < 0.05), crop yield (p < 0.05) and adequacy (p < 0.05) varied significantly across the zones. The soil texture was found to be sandy clay loam (SCL) in the Upper and Medium zones and sandy loam (SL) in the Lower zone, with the levels of sand (p < 0.05) and clay (p < 0.05) varying significantly across the zones; the mean pH values were weakly acidic (p < 0.05), adequate and varied significantly across the zones; mean total organic carbon was below 1.33 % (p < 0.05), deficient and significantly varied; mean percent total nitrogen was less than 0.2 % (p < 0.05), deficient and significantly varied; mean total phosphorus ranged between deficient (25.700?9.710 mg/Kg in the Medium zone) to adequate (6S.700?17.975 mg/Kg in the Upper zone); while the mean level of potassium was above 93.60 mg/Kg (p < 0.05), adequate and significantly varied across the zones. The study concluded that many of both the local and scientific indicators of soil fertility significantly varied across the Upper, Medium and Lower zones of Wundanyi division and were therefore sensitive indicators of soil fertility; the soil pH was adequate; total organic carbon deficient; total nitrogen deficient; phosphorus ranged between deficient and adequate; while potassium was adequate. The information obtained may be used for customized sensitization of farmers on integrated soil fertility management, as a source of data for objective policy and further research.

Genetic diversity and nitrogen fixing potential of legume nodulating bacteria from different land use systems in Taita District, Kenya

Author: Mwangi, Simon Ngare

Awarding University: Jomo Kenyatta University of Agriculture and Technology, Kenya

Level : MSc

Year: 2011

Holding Libraries: Jomo Kenyatta University of Agriculture and Technology Library ;

Subject Terms: Legumes ; Nodulation ; Nitrogen ; Soil fertility ; Taita District ; Genetics ; Rhizobium ;

Abstract:

Soil fertility is a serious problem especially in tropical and subtropical regions of the developing countries. Available soil nitrogen is one of the most limiting factors to crop production. Lack of nitrogen in soils can be addressed by exploitation of legumeRhizobia symbiosis in agricultural systems. Exploitation of Rhizobia requires knowledge of leguminosae nodulating bacteria (LNB) available from different agro-ecological zones and their symbiotic potential. The populations of Leguminosae nodulating bacteria (LNB) were assessed under glasshouse conditions in soils collected from Maize based mixed farming, Fallow land, indigenous forest, agro-forestry and planted forest in Taita district, Kenya. LNB were isolated from root nodules of nodulated siratro inoculated with dilution series of the soils. About 2008 pure isolates obtained from root nodules of siratro from a previous study on most probable number (MPN). The isolates were characterized on yeast extract mannitol mineral salts agar (YEMA) media containing bromothymol blue. The isolates fell into two major growth rate types: fast growers (acidproducing) and slow growers (alkali-producing). Slow- and fast-growing types constituted 21.41 % and 78.59 % of isolates, respectively. Percent symbiotic efficiency of the isolate was also calculated. (shoot dry weight of inoculated plants over shoot dry weight of a nitrogen supplemented plants control). SE of the isolates varied and ranged from 6.7% to 95.4%. RFLP of amplified 16S rRNA genes of isolates with HaeIlI and TaqI was used to group the isolates into seven ribotypes, partial sequencing of 16S rRNA genes of representative isolates of the ribotypes further grouped the isolates into six genera namely:-Sinorhizobium, Bradyrhizobium, Herbaspirillum, Agrobacterium, Rhizobium and Burkholderia. Land use type was found to significantly influence the diversity ofLNB (P<O.05). The highest LNB total richness of5 was found in indigenous forest soils. Isolate 6 and MAS from agro-forestry and indigenous forest respectively had the highest symbiotic efficiency.

Effect of Arbuscular mycorrhizal fungi (AMF) inoculation and management of indigenous AMF population on the ex-situ performance of maize and beans in Embu and Taita Districts , Kenya

Author: Mwangi, John Nyaga

Awarding University: Jomo Kenyatta University of Agriculture and Technology, Kenya

Level : MSc

Year: 2011

Holding Libraries: Jomo Kenyatta University of Agriculture and Technology Library ;

Subject Terms: Embu District ; Taita District ; Mycorrhizas ; Fungi ; Maize ; Zea mays ; Beans ; Phaseolus vulgaris ; Manures ; Soil fertility ;

Abstract:

Many experiments examining the effect of Arbuscular Mycorrhizal Fungi (AMF) on crops are ambiguous and many of those demonstrating positive effects have been carried out in the greenhouse using simplified systems rendering the results not easily reproducible in the field. Therefore field experiments become necessary considering gaps in understanding of the Arbuscular Mycorrhizal (AM) association, importance of AMF species diversity and the effect of different agronomic practices on the ecology and function of AMF. The study demonstrated the importance of mycorrhizae in agricultural production systems in tropical landscapes, through establishing effects of various soil fertility management practices such as use of different fertilizers, use of manure, and slow releasing rock phosphate (mijingu) on AMF. Effect of direct AMF inoculation in the field and management of indigenous population and the performance of maize and bean were also evaluated. Soil from Below Ground Biodiversity (BGBD) test strips and demonstration blocks under FP (combination of TSP and CAN), mijingu, manure and mavuno (organic fertilize) application were sampled. The effects of existing AMF and AMF introduced across management practices were evaluated and compared to plant growth and yield. Mycorrhizal density and prevalence was determined over a period of two cropping seasons and the experiment replicated in the two benchmark sites namely Embu in the highlands of central Kenya and the coastal highlands in TaitaTaveta. This constituted the on-farm experiments of the project. On-station experiments were also set up and direct inoculation of AMF was done on common bean (phaseolus vulgaris L) and maize (Zea mays L) intercrop; effects on crop performance were determined. Field inoculation with AMF has been demonstrated to positively affect the yield of maize and bean at Embu experimental site though not significantly different with application of the different soil fertility amendments. The use of inorganic and organic fertilizers enhanced AMF utilization; the addition of these fertilizers to AMF led to higher crop yield as well as root colonisation compared to plots under AMF applied alone. A total of 15 AMF morphotypes were isolated and described from both Taita and Embu sites, majority being Gigasporaceae (9), followed by Acaulosporaceae (4) and Glomaceae (2). The highest species count was obtained from 0-10cm depth. Inoculation of plots with AMF was found to increase the total AMF abundance in the soil. However there was no significant (p 2: 0.05) difference in spore abundance at onstation experiments with use of different soil fertility amendment practices in the first season but varied less significantly (p :::: 0.05) after the second season but a marked reduction in AMF population was recorded with passage of each cropping season. Onfarm experiments (test strips) also recorded a reduction in AMF population with subsequent season. The spore abundance showed no significant difference with application of the different soil amendments. This was also the case with species richness in the soil during the two seasons. In demonstration plots, there were significant (p :::: 0.05) differences in spore abundance among the different soil fertility amendment practices. Also a marked decrease in AMF population in subsequent cropping season was recorded There was higher root colonisation as well as spore abundance in the soil under manure application with subsequent average maize and bean production. Manure application was found to be the best method to conserve AMF population in the soil and thus recommended as a cheap and an environmentally friendly method of soil fertility management.