Chemical sensors based on swelling polymer microspheres and uncrosslinked fluorescently-labelled molecularly imprinted polymers

Polymer swelling can be achieved by derivatizing a functional group onto the polymer that selectively binds a particular analyte. For example, at low pH, the particles in a hydrogel membrane swell in response to the increased hydrogen ion concentration and the membrane reflects less light. When the refractive index of the membrane is less than that of the particles, swelling decreases the refractive index of the particles. This brings it closer to the refractive index of the membrane, and decreases the scattering of light making the membrane more transparent. On the other hand if the refractive index of the membrane is higher than that of the microspheres, swelling of the microspheres increases the difference between the refractive indices of the two media. This makes the membrane less transparent. By coupling selective polymer swelling with a transduction method that responds to the changes in polymer size, it is possible to make a chemical sensor. Polymer microspheres that change size as a function of pH and metal ion concentration have been prepared by suspension and dispersion polymerization respectively. For the pH sensor, poly (vinylbenzylchloride) was prepared by suspension polymerization using the Shirazu porous glass (SPG) method. The particles were lightly crosslinked with divinylbenzene followed by amination with NNN\u27-trimethylethylenediamine. Poly (hydroxyethylmethacrylate)(polyHEMA) microspheres were prepared by dispersion polymerization and then derivatized with diethylenetriamine. These aminated polymer microspheres suspended in PVA and polyurethane hydrogels respond to Cu2+ ions in solution. The complexation ratio of Cu2+: N was determined to be 1:2. The response time is ∼minutes, which is much longer than was observed with pH response. This was attributed to the bigger size of Cu2+, which restricts their movement into the polymer microspheres. A new design of a molecularly imprinted polymer was developed. It was based on theophylline templated, uncrosslinked poly N-n-propylacrylamide (polyNNPAM) (principal monomer), co-polymerized with 4-(2-acroyloyloxyethylamino)-7-nitro-2, 1,3-benzoxadiazole (NBD-AE2) (fluorophore) and methacrylic acid (MAA) (functional monomer). This polymer was prepared by dispersion polymerization in acetonitrile solvent. Since the co-polymer remains in solution rather than as a separate phase (because of the absence of crosslinks), dialysis was the method chosen to extract the template, with many changes of the external solution. The sensor responds by increase in fluorescence with increased concentrations of theophylline. It was shown to have a high sensitivity (1 x 10-7M) and was highly selective because there was no change in fluorescence for increasing caffeine concentration up to 1 x 10-3M

First season maize performance in a long-term farming systems comparison trial at KARI-Thika, Kenya

Kenya’s smallholder farmers contribute 65% to total agricultural output in a predominantly mixed farming system where application of inorganic fertilizers and pesticides is minimal. By contrast, agriculture in developed temperate countries is dominated by large-scale farming and heavy reliance on fertilizers and pesticides to sustain high yields. Research conducted in temperate developed countries has shown that organic farming is superior to conventional farming in resource use efficiency, ecosystem functioning, soil fertility conservation and economic performance but results cannot be transferred directly to the tropics because of disparities in climate, soils and socio-economic environments. A long-term farming systems comparisons experiment was initiated at KARI-Thika in 2006 to assess the contribution of organic agriculture to food security, poverty alleviation and environmental conservation. Four treatments (Conventional High, Conventional Low, Organic High and Organic Low) were imposed in 8m x 8m plots using a randomized complete block design and replicated five times. The ‘High’ treatments received 118 kgN/ha and 66+5kgP/ha while the ‘Low’ treatments received 65 kgN/ha and 27 kgP/ha. Conventional treatments received the nutrients from farmyard manure, diammonium phosphate and calcium ammonium phosphate while compost, Tithonia diversifolia, and phosphate rock were applied in the organic treatments. Maize variety Pannar was planted at the onset of rains in April 2007 and harvested in August from a net plot area of 6m x 6m. The plots were hand weeded while stock borer was controlled using a Neem extract and ash/soil mixture in organic treatments and Bulldock® in conventional treatments. Stover dry weights were significantly higher in Conventional High than Organic Low (P=0.034) and indistinguishable from those observed in Conventional Low and Organic High. It was reasoned that availability of applied nutrients and the low poorly distributed rainfall received during the flowering and grain filling stages impacted negatively on grain yield

Child Survival, Poverty and Policy Options from DHS Surveys in Kenya: 1993-2003

This paper analyses multidimensional aspects of child poverty in Kenya. We carry out poverty and inequality comparisons for child survival and also use the parametric survival model to explain childhood mortality using DHS data. The results of poverty comparisons show that: children with the lowest probability of survival are from households with the lowest level of assets; and poverty orderings for child survival by assets are robust to the choice of the poverty line and to the measure of wellbeing. Inequality analysis suggests that there is less mortality inequality among children facing mortality than children who are better off. The survival model results show that child and maternal characteristics, and household assets are important correlates of childhood mortality. The results further show that health care services are crucial for child survival. Policy simulations suggest that there is potential for making some progress in reducing mortality, but the ERS and MDG targets cannot be achieved.Child survival, multidimensional poverty, inequality, stochastic dominance, childhood mortality, asset index, Kenya

Enhancing Completion Rates in Public Day Secondary Schools in Kenya; the Role of Government Bursary Subsidy

The purpose of the study was to investigate the influence of Government Bursaries on completion rates in public day secondary schools in Kitui County, Kenya. The journal is based on findings of a study conducted in 2017. The objectives of the study were; to investigate the influence of government bursaries on retention rates in day secondary schools in Kitui County; to assess the influence of government bursaries on dropout rates in day secondary schools in Kitui County; to assess the role government bursaries on retention rates in day secondary schools in ASAL areas of Kitui County; to assess the relationship between government bursaries and completion rates in day secondary schools in Kitui County. The study adopted descriptive survey research design. The study sample was 119 principals of public day secondary schools in Kitui County, 16 treasurers of Constituency Bursary Fund and one County Director of Education. Data was collected using a questionnaire, interview schedules and document review guide. Validity of the research instruments was ascertained through piloting and expert judgement. A test-re-test technique was used to assess reliability of the research instruments. The scores were correlated to get the co-efficient of stability using Spearman’s coefficient of correlation and an instrument reliability value of 0.823 was obtained. Descriptive and inferential statistics was used to analyse data using Statistical Package for Social Science (SPSS). Chi-square (χ²) was used to analyse hypothesis. The study found that government bursaries given to day secondary schools were not adequate to finance education expenses of the learner; the study further found that government bursaries increase retention rates in day public secondary schools; The study also found that government bursaries ensures learners in public day secondary schools in ASALs benefit from education. The study recommended that government should allocate more funds for bursaries in public day secondary schools. The study concluded that there is no consistency in disbursement of government bursaries in public day secondary schools

An assessment of sexual and gender based violence in Wajir district, North Eastern Kenya

A 2006 baseline survey conducted by CARE Kenya indicated that sexual and gender-based violence (SGBV) is widespread throughout Kenya’s North Eastern Province. Other findings revealed that high levels of stigma and gender imbalances are associated with sexual violence and female genital mutilation (FGM) and that a coordinated approach to responding to the service needs of survivors is missing. As noted in this report, there is limited awareness of the legal mechanisms available to survivors. The Population Council’s study in Wajir District ascertained the need for and possible components of an integrated and comprehensive services model that could meet the needs of SGBV survivors in the province. Unmarried girls between the ages of 9 and 15 years appear to be the most vulnerable. Intimate partner violence (IPV), especially male to female spousal physical abuse, is also widespread. Male to female physical abuse often precedes sexual abuse within marriage. Female to male spousal physical abuse was also reported. The practice of FGM, which can make sexual intercourse painful, was suggested by women and youth as a possible reason for high levels of marital rape

Ohio CCRCs in the Economic Downturn

This report examines how the economic downturn affected consumer opinions about choosing a CCRC and how the CCRCs in Ohio made adjustments in response to declining numbers of prospective residents. One hundred-sixty five Ohio CCRCs are included in the survey results

Dairy Cow Ownership and Child Nutritional Status in Kenya

This study examines the hypothesis that dairy cow ownership improves child nutritional status. Using household data from coastal and highland Kenya, three econometric model formulations are estimated. Positive impacts on chronic malnutrition are observed for coastal Kenya. No negative effects on acute or chronic malnutrition are found for either region.Food Consumption/Nutrition/Food Safety, Livestock Production/Industries,

Blind Naso-Endotracheal Intubation

Patients with ‘difficult endotracheal intubation’ may present for elective or emergency surgery. We present a case of a 29 year old female patient who required general anaesthesia for resection of a large mandibular osteosarcoma where the blind nasoendotracheal intubation technique was used

Perception of University Managers on the Influence of Organizational Structure on Quality of Management in Public and Private Universities in Kenya

Quality of institutional management is arguably a major determinant of organizational performance.  The role of managers and the activities and tasks they perform as aided by the organizational structure could lead to the effective and efficient implementation of organizational objectives and goals.  This study was undertaken to establish the perception of university managers on the influence of organizational structure on the quality of institutional management of universities in Kenya.  The study design was descriptive research. Purposive sampling procedure was used in selecting the universities.  Random stratification sampling was used to administer the questionnaire to the managers in the universities.  Positive responses were received from 137 managers from a target of 263 giving a 62.6%  response rate.  The response from university managers showed an average positive response rate at 60%.  There was a statistically significant difference at (p<0.05) on the perception of managers in the public and private universities on the influence of organizational structure on the dimension of customer satisfaction. The organizational structures in the private universities were found to be more customer centric than those of public universities. Private universities management practices emphasized concern for customer needs.  This translated into provision of quality services and products in order to meet customers’ expectations for their satisfaction and retention.  . Keywords: Organizational Structures, Quality of Management, Customer satisfaction, Structural Flexibility, Decision making, Teamwork DOI: 10.7176/EJBM/13-20-06 Publication date:October 31st 202

The effect of alpha(+)-thalassaemia on the incidence of malaria and other diseases in children living on the coast of Kenya

BACKGROUND: The alpha-thalassaemias are the commonest genetic disorders of humans. It is generally believed that this high frequency reflects selection through a survival advantage against death from malaria; nevertheless, the epidemiological description of the relationships between alpha-thalassaemia, malaria, and other common causes of child mortality remains incomplete. METHODS AND FINDINGS: We studied the alpha+-thalassaemia-specific incidence of malaria and other common childhood diseases in two cohorts of children living on the coast of Kenya. We found no associations between alpha+-thalassaemia and the prevalence of symptomless Plasmodium falciparum parasitaemia, the incidence of uncomplicated P. falciparum disease, or parasite densities during mild or severe malaria episodes. However, we found significant negative associations between alpha+-thalassaemia and the incidence rates of severe malaria and severe anaemia (haemoglobin concentration < 50 g/l). The strongest associations were for severe malaria anaemia (> 10,000 P. falciparum parasites/mul) and severe nonmalaria anaemia; the incidence rate ratios and 95% confidence intervals (CIs) for alpha+-thalassaemia heterozygotes and homozygotes combined compared to normal children were, for severe malaria anaemia, 0.33 (95% CI, 0.15,0.73; p = 0.006), and for severe nonmalaria anaemia, 0.26 (95% CI, 0.09,0.77; p = 0.015). CONCLUSIONS: Our observations suggest, first that selection for alpha+-thalassaemia might be mediated by a specific effect against severe anaemia, an observation that may lead to fresh insights into the aetiology of this important condition. Second, although alpha+-thalassaemia is strongly protective against severe and fatal malaria, its effects are not detectable at the level of any other malaria outcome; this result provides a cautionary example for studies aimed at testing malaria interventions or identifying new malaria-protective genes