Factors Influencing Technical Efficiencies among Selected Wheat Farmers in Uasin Gishu District, Kenya

This study examined the factors influencing technical efficiency in wheat farming in Kenya using a stochastic frontier production function in which technical inefficiency effects were assumed to be functions of both socioeconomic characteristics of the farmer and farm-specific characteristics. The paper used random sampling to interview 160 farmers comprising 97 large-scale farmers and 63 small-scale farmers. The results revealed existence of significant levels of technical inefficiencies in wheatproduction, especially among the large-scale farmers. The study found that the magnitude of technical efficiency varied from one farmer to another and ranged from 48.9% to 95.1%, with a mean of 87.2%. This implied that farmers lost close to 13% of the potential output to technical inefficiencies. There was variation depending on the size of farm with small-scale farmers attaining higher technical efficiency than the large-scale farmers. The main factors that influenced the degree of inefficiency were education levels, access to credit, and ownership of the capital equipment. Higher levels of education (12 years and above or secondary and above) significantly reduced inefficiency as did access to credit facilities and owning the farm equipment. The study recommended that farmers be educated on the use of better techniques such as use of certified seeds and application of recommended levels of fertilizer.

A tomographic ocean sound speed profile from a long veritcal acoustic array

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 1992An average sound speed profile over a 1000 km section of the northeast Pacific ocean is obtained using Ocean Acoustic Tomography, from data acquired during the 1987 SVLA experiment on a long (900 m) 120 hydrophone vertical acoustic array. In particular, we pulse compress the received signal with a phase-only matched filter. The signal, centered at 80Hz, is phase-modulated by a maximal length sequence. A fast m-sequence cross-correlation algorithm based on the Hadamard transform is used. In addition, wide band Doppler correction and coherent averaging of repetitions of the signal are performed. The tomographic inversion is initialized from a range averaged climatological profile. Multipaths are identified from ray theory. The identified arrivals are inverted for a range-independent sound speed profile change estimate. Estimates of source and array position error are also obtained. For the limited data set used, the sound speed change estimate is found to be insignificant, and a significant instrument position estimate is obtained

Human metapneumovirus epidemiological and evolutionary patterns in Coastal Kenya, 2007-11

Background: Human metapneumovirus (HMPV) is an important global cause of severe acute respiratory infections in young children and the elderly. The epidemiology of HMPV in sub-Saharan Africa is poorly described and factors that allow its recurrent epidemics in communities not understood. Methods: We undertook paediatric inpatient surveillance for HMPV in Kilifi County Hospital (KCH) of Coastal Kenya between 2007 and 2011. Nasopharyngeal samples collected from children aged 1 day–59 months admitted with severe or very severe pneumonia, were tested for HMPV using real-time polymerase chain reaction (RT-PCR). Partial nucleotide sequences of the attachment (G) and fusion (F) surface proteins of positive samples were determined and phylogenetically analyzed. Results: HMPV was detected in 4.8 % (160/3320) of children [73.8 % (118/160) of these less than one year of age], ranging between 2.9 and 8.8 % each year over the 5 years of study. HMPV infections were seasonal in occurrence, with cases predominant in the months of November through April. These months frequently coincided with low rainfall, high temperature and low relative humidity in the location. Phylogenetic analysis of partial F and G sequences revealed three subgroups of HMPV, A2 (74 %, 91/123), B1 (3.2 %, 4/123) and B2 (22.8 %, 28/123) in circulation, with subgroup A2 predominant in majority of the epidemic seasons. Comparison of G sequences (local and global) provided a greater phylogenetic resolution over comparison of F sequences and indicated presence of probable multiple G antigenic variants within the subgroups due to differences in amino acid sequence, encoded protein length and glycosylation patterns. Conclusion: The present study reveals HMPV is an important seasonal contributor to respiratory disease hospitalization in coastal Kenya, with an evolutionary pattern closely relating to that of respiratory syncytial virus

Molecular characterization of rotavirus group A strains circulating prior to vaccine introduction in rural coastal Kenya, 2002-2013

Background Kenya introduced the monovalent Rotarix® rotavirus group A (RVA) vaccine nationally in mid-2014. Long-term surveillance data is important prior to wide-scale vaccine use to assess the impact on disease and to investigate the occurrence of heterotypic strains arising through immune selection. This report presents baseline data on RVA genotype circulation patterns and intra-genotype genetic diversity over a 7-year period in the pre-vaccine era in Kilifi, Kenya, from 2002 to 2004 and from 2010 to 2013. Methods A total of 745 RVA strains identified in children admitted with acute gastroenteritis to a referral hospital in Coastal Kenya, were sequenced using the di-deoxy sequencing method in the VP4 and VP7 genomic segments (encoding P and G proteins, respectively). Sequencing successfully generated 569 (76%) and 572 (77%) consensus sequences for the VP4 and VP7 genes respectively. G and P genotypes were determined by use of BLAST and the online RotaC v2 RVA classification tool. Results The most common GP combination was G1P[8] (51%), similar to the Rotarix® strain, followed by G9P[8] (15%) , G8P[4] (14%) and G2P[4] (5%). Unusual GP combinations—G1P[4], G2P[8], G3P[4,6], G8P[8,14], and G12P[4,6,8]—were observed at frequencies of <5%. Phylogenetic analysis showed that the infections were caused by both locally persistent strains as evidenced by divergence of local strains occurring over multiple seasons from the global ones, and newly introduced strains, which were closely related to global strains. The circulating RVA diversity showed temporal fluctuations both season by season and over the longer-term. None of the unusual strains increased in frequency over the observation period. Conclusions The circulating RVA diversity showed temporal fluctuations with several unusual strains recorded, which rarely caused major outbreaks. These data will be useful in interpreting genotype patterns observed in the region during the vaccine er

Digital Signal Processing Research Program

Contains table of contents for Part III, table of contents for Section 1, an introduction and reports on seventeen research projects.U.S. Navy - Office of Naval Research Contract N00014-90-J-1544Charles S. Draper Laboratory Contract DL-H-404158Rockwell Corporation Doctoral FellowshipU.S. Navy - Office of Naval Research Grant N00014-89-J-1489U.S. Navy - Office of Naval Research Grant N00014-90-J-1109The Federative Republic of Brazil ScholarshipLockheed Sanders, Inc.National Science Foundation Grant MIP 87-14969AT&T Bell Laboratories Doctoral ProgramBell Northern Research Ltd.Defense Advanced Research Projects Agency Contract N00014-87-K-0825IBM CorporationSloan FoundationU.S. Air Force - Office of Scientific Research FellowshipU.S. Air Force - Office of Scientific Research Grant AFOSR-91-0034National Science Foundation Graduate FellowshipCanada, Natural Science and Engineering Research Council ScholarshipU.S. Air Force - Office of Scientific Research Grant AFOSR-91-0034Texas Instruments, Inc

Digital Signal Processing Research Program

Contains table of contents for Section 2, an introduction and reports on seventeen research projects.U.S. Navy - Office of Naval Research Grant N00014-91-J-1628Vertical Arrays for the Heard Island Experiment Award No. SC 48548Charles S. Draper Laboratories, Inc. Contract DL-H-418472Defense Advanced Research Projects Agency/U.S. Navy - Office of Naval Research Grant N00014-89-J-1489Rockwell Corporation Doctoral FellowshipMIT - Woods Hole Oceanographic Institution Joint ProgramDefense Advanced Research Projects Agency/U.S. Navy - Office of Naval Research Grant N00014-90-J-1109Lockheed Sanders, Inc./U.S. Navy - Office of Naval Research Contract N00014-91-C-0125U.S. Air Force - Office of Scientific Research Grant AFOSR-91-0034AT&T Laboratories Doctoral ProgramU.S. Navy - Office of Naval Research Grant N00014-91-J-1628General Electric Foundation Graduate Fellowship in Electrical EngineeringNational Science Foundation Grant MIP 87-14969National Science Foundation Graduate FellowshipCanada Natural Sciences and Engineering Research CouncilLockheed Sanders, Inc

Digital Signal Processing Research Program

Contains table of contents for Section 2, an introduction and reports on fourteen research projects.U.S. Navy - Office of Naval Research Grant N00014-91-J-1628Defense Advanced Research Projects Agency/U.S. Navy - Office of Naval Research Grant N00014-89-J-1489MIT - Woods Hole Oceanographic Institution Joint ProgramLockheed Sanders, Inc./U.S. Navy Office of Naval Research Contract N00014-91-C-0125U.S. Air Force - Office of Scientific Research Grant AFOSR-91-0034U.S. Navy - Office of Naval Research Grant N00014-91-J-1628AT&T Laboratories Doctoral Support ProgramNational Science Foundation Fellowshi

Integrating human papillomavirus testing as a point-of care service using GeneXpert platforms: Findings and lessons from a Kenyan pilot study (2019–2020)

Background: Globally, cervical cancer is a major public health problem, with about 604,000 new cases and over 340,000 deaths in 2020. In Kenya, it is the leading cause of cancer deaths, with over 3,000 women dying in 2020 alone. Both the Kenyan cancer screening guidelines and the World Health Organization’s Global Cervical Cancer Elimination Strategy recommend human papillomavirus (HPV) testing as the primary screening test. However, HPV testing is not widely available in the public healthcare system in Kenya. We conducted a pilot study using a point of care (POC) HPV test to inform national roll-out. Methods: The pilot was implemented from October 2019 to December 2020, in nine health facilities across six counties. We utilized the GeneXpert platform (Cepheid, Sunnyvale, CA, USA), currently used for TB, Viral load testing and early infant diagnosis for HIV, for HPV screening. Visual inspection with acetic acid (VIA) was used for triage of HPV-positive women, as recommended in national guidelines. Quality assurance (QA) was performed by the National Oncology Reference Laboratory (NORL), using the COBAS 4800 platform (Roche Molecular System, Pleasanton, CF, USA). HPV testing was done using either self or clinician-collected samples. We assessed the following screening performance indicators: screening coverage, screen test positivity, triage compliance, triage positivity and treatment compliance. Test agreement between local GeneXpert and central comparator high-risk HPV (hrHPV) testing for a random set of specimens was calculated as overall concordance and kappa value. We conducted a final evaluation and applied the Nominal Group Technique (NGT) to identify implementation challenges and opportunities. Key findings: The screening coverage of target population was 27.0% (4500/16,666); 52.8% (2376/4500) were between 30–49 years of age. HPV positivity rate was 22.8% (1027/4500). Only 10% (105/1027) of HPV positive cases were triaged with VIA/VILI; 21% (22/105) tested VIA/VILI positive, and 73% (16/22) received treatment (15 received cryotherapy, 1 was referred for biopsy). The median HPV testing turnaround time (TAT) was 24 hours (IQR 2–48 hours). Invalid sample rate was 2.0% (91/4500). Concordance between the Cepheid and COBAS was 86.2% (kappa value = 0.71). Of 1042 healthcare workers, only 5.6% (58/1042) were trained in cervical cancer screening and treatment, and only 69% (40/58) of those trained were stationed at service provision areas. Testing capacity was identifed as the main challenge, while the community strategy was the main opportunity. Conclusion: HPV testing can be performed on GeneXpert as a near point of care platform. However, triage compliance and testing TAT were major concerns. We recommend strengthening of the screening-triage-treatment cascade and expansion of testing capacity, before adoption of a GeneXpert-based HPV screening among other near point of care platforms in Kenya

Towards low-cost soil fertility sensor systems for smallholder food security in Kenya

Agricultural production is increasingly threatened by environmental changes, including climate variability and soil degradation. These challenges have led to a pressing need for adaptive strategies to maintain soil health and optimize nutrient use. Smallholder farmers in low- and middle-income countries (LMICs) often lack the capacity for continuous soil monitoring due to the high costs associated with conventional soil testing. However, even in developed nations, access to affordable, sustainable soil health assessment tools remains limited. The current available sensor electrodes are traditionally made from non-biodegradable materials, contributing to electronic waste and environmental pollution. This project aims to develop low-cost, biodegradable soil nutrient sensors using easily accessible materials, including waste newspaper, carbon black (or charcoal), graphite, egg yolk, and gum arabic among other additives. The electrodes will be fabricated through block printing techniques, ensuring scalability and adaptability for low-tech, decentralized production. Enzyme modification will be conducted to enable ion selectivity therefore enabling real-time soil analysis through electrochemical detection of key nutrients such as nitrate, phosphate, and potassium. By integrating these eco-friendly materials and techniques, the proposed sensors will offer an affordable, sustainable, and effective solution for real-time soil nutrient monitoring. This will empower farmers with real-time, data-driven insights, supporting sustainable agricultural practices and climate resilience