273 results on '"Cheruiyot, P"'
Search Results
102. Importance of TGFβ in Cancer and Nematode Infection and Their Interaction—Opinion
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Marta Maruszewska-Cheruiyot, Michael James Stear, Maja Machcińska, and Katarzyna Donskow-Łysoniewska
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TGFβ ,TGFβ mimic ,nematode ,cancer ,immunomodulation ,Microbiology ,QR1-502 - Abstract
Historically, there has been little interaction between parasitologists and oncologists, although some helminth infections predispose to the development of tumours. In addition, both parasites and tumours need to survive immune attack. Recent research suggests that both tumours and parasites suppress the immune response to increase their chances of survival. They both co-opt the transforming growth factor beta (TGFβ) signalling pathway to modulate the immune response to their benefit. In particular, there is concern that suppression of the immune response by nematodes and their products could enhance susceptibility to tumours in both natural and artificial infections.
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- 2022
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103. Bismuth Sulfide Doped in Graphitic Carbon Nitride Degrades Nitric Oxide under Solar Irradiation
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Adnan Hussain, Chitsan Lin, Nicholas Kiprotich Cheruiyot, Wen-Yen Huang, Kuen-Song Lin, and Abrar Hussain
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air pollution ,heterojunction photocatalyst ,solar light degradation ,thermal decomposition ,Chemistry ,QD1-999 - Abstract
This study developed and examined the application of bismuth sulfide doped on graphitic carbon nitride (Bi2S3@g-C3N4) in the degradation of NO under solar irradiation. Bi2S3@g-C3N4 was prepared through the calcination method. The morphological structure and chemical properties of the synthesized photocatalyst were analyzed before the degradation tests. After doping with Bi2S3@g-C3N4, the bandgap was reduced to 2.76 eV, which increased the absorption of solar light. As a result, the Bi2S3@g-C3N4 achieved higher NO degradation (55%) compared to pure Bi2S3 (35%) and g-C3N4 (45%). The trapping test revealed that the electrons were the primary species responsible for most of the NO degradation. The photocatalyst was stable under repeated solar irradiation, maintaining degradation efficiencies of 50% after five consecutive recycling tests. The present work offers strong evidence that Bi2S3@g-C3N4 is a stable and efficient catalyst for the photocatalytic oxidation of NO over solar irradiation.
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- 2022
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104. Pooled testing conserves SARS-CoV-2 laboratory resources and improves test turn-around time: experience on the Kenyan Coast [version 1; peer review: 3 approved]
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Charles N. Agoti, Martin Mutunga, Arnold W. Lambisia, Domtila Kimani, Robinson Cheruiyot, Patience Kiyuka, Clement Lewa, Elijah Gicheru, Metrine Tendwa, Khadija Said Mohammed, Victor Osoti, Johnstone Makale, Brian Tawa, Calleb Odundo, Wesley Cheruiyot, Wilfred Nyamu, Wilson Gumbi, Jedidah Mwacharo, Lydia Nyamako, Edward Otieno, David Amadi, Janet Thoya, Angela Karani, Daisy Mugo, Jennifer Musyoki, Horace Gumba, Salim Mwarumba, Bonface M. Gichuki, Susan Njuguna, Debra Riako, Shadrack Mutua, John N. Gitonga, Yiakon Sein, Brian Bartilol, Shaban J. Mwangi, Donwilliams O. Omuoyo, John M. Morobe, Zaydah R. de Laurent, Philip Bejon, Lynette Isabella Ochola-Oyier, and Benjamin Tsofa
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Medicine ,Science - Abstract
Background. International recommendations for the control of the coronavirus disease 2019 (COVID-19) pandemic emphasize the central role of laboratory testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent, at scale. The availability of testing reagents, laboratory equipment and qualified staff are important bottlenecks to achieving this. Elsewhere, pooled testing (i.e. combining multiple samples in the same reaction) has been suggested to increase testing capacities in the pandemic period. Methods. We discuss our experience with SARS-CoV-2 pooled testing using real-time reverse transcription polymerase chain reaction (RT-PCR) on the Kenyan Coast. Results. In mid-May, 2020, our RT-PCR testing capacity for SARS-CoV-2 was improved by ~100% as a result of adoption of a six-sample pooled testing strategy. This was accompanied with a concomitant saving of ~50% of SARS-CoV-2 laboratory test kits at both the RNA extraction and RT-PCR stages. However, pooled testing came with a slight decline of test sensitivity. The RT-PCR cycle threshold value (ΔCt) was ~1.59 higher for samples tested in pools compared to samples tested singly. Conclusions. Pooled testing is a useful strategy to increase SARS-CoV-2 laboratory testing capacity especially in low-income settings.
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- 2020
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105. Insights into the design, development and implementation of a novel digital health tool for skilled birth attendants to support quality maternity care in Kenya
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Alain Labrique, Linda Bartlett, Mark Allen, Lisa Avery, Priya Ponnappan, Judith Chelangat, Jackline Cheruiyot, Rose Matthews, Mary Rocheleau, Mari Tikkanen, and Paul Amendola
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Medicine (General) ,R5-920 - Published
- 2021
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106. Inion Not a Reliable Landmark of the Torcula in Posterior Fossa Craniotomies
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Elisha Harry Otieno, Philip Mwachaka, Paul Odula, Isaac Cheruiyot, and Jeremiah Munguti
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inion ,posterior fossa ,craniotomies ,Surgery ,RD1-811 - Abstract
Background: Sub-occipital craniotomies are used in surgical approaches into the posterior cranial fossa. The inion is used as an extracranial landmark of the torcula in burr hole placement. However, inadvertent damage to the torcula and the related sinuses due to variant intracranial location of the torcula has been reported. This study aimed at determining the position of the torcula in relation to the inion. Method: 40 adult open skulls were obtained and the positional relationship between the inion and the torcula assessed. Results: The torcula was at the same level with the inion in half of the cases (50%), below it in 12 cases (30%), and above in 8 cases (20%). The position above the inion ranged from 0.38 to 2.40 cm and below it from 0.75 to 2.45 cm. Conclusion: The torcula lies either at the level of the inion in only half of the cases. The surgeon should augment this physical landmark with radiographs to avoid iatrogenic injuries.
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- 2020
107. A high-intensity cluster of Schistosoma mansoni infection around Mbita causeway, western Kenya: a confirmatory cross-sectional survey
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Evans Asena Chadeka, Sachiyo Nagi, Ngetich B. Cheruiyot, Felix Bahati, Toshihiko Sunahara, Sammy M. Njenga, and Shinjiro Hamano
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Schistosomiasis ,Clustering ,Mbita causeway ,Western Kenya ,Arctic medicine. Tropical medicine ,RC955-962 - Abstract
Abstract In Kenya, communities residing along the shores and islands of Lake Victoria bear a substantial burden of schistosomiasis. Although there is a school-based deworming program in place, the transmission of Schistosoma mansoni varies even at a fine scale. Given the focal nature of schistosomes’ transmission, we aim to identify areas with high intensity of S. mansoni infection in Mbita, Homabay County, western Kenya, for prioritized integrated control measures. Our findings confirm a high intensity of S. mansoni infection cluster around Mbita causeway. While the current efforts to curtail morbidity due to schistosomiasis through preventive chemotherapy in schools are crucial, fine-scale mapping of risk areas is necessary for specific integrated control measures.
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- 2019
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108. Galectins - Important players of the immune response to CNS parasitic infection
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Marta Maruszewska-Cheruiyot, Michael Stear, and Katarzyna Donskow-Łysoniewska
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Galectins ,Parasite ,Behavior ,Mental diseases ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Galectins are a family of proteins that bind β-galactosides and play key roles in a variety of cellular processes including host defense and entry of parasites into the host cells. They have been well studied in hosts but less so in parasites. As both host and parasite galectins are highly upregulated proteins following infection, galectins are an area of increasing interest and their role in immune modulation has only recently become clear. Correlation of CNS parasitic diseases with mental disorders as a result of direct or indirect interaction has been observed. Therefore, galectins produced by the parasite should be taken into consideration as potential therapeutic agents.
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- 2021
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109. Cocreated regional research agenda for evidence-informed policy and advocacy to improve adolescent sexual and reproductive health and rights in sub-Saharan Africa
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Anthony Idowu Ajayi, Boniface Ayanbekongshie Ushie, Emmy Kageha Igonya, Ramatou Ouedraogo, Kenneth Juma, Grace Kibunja, Collins Cheruiyot, Winnie Opondo, Emmanuel Otukpa, and Caroline Kabiru
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Medicine (General) ,R5-920 ,Infectious and parasitic diseases ,RC109-216 - Published
- 2021
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110. Human immunodeficiency virus (HIV) type 1 genetic diversity in HIV positive individuals on antiretroviral therapy in a cross sectional study conducted in Teso, Western Kenya
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Maureen Adhiambo, Olipher Makwaga, Ferdinard Adungo, Humphrey Kimani, David Hughes Mulama, Jackson Cheruiyot Korir, and Matilu Mwau
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hiv-1 ,subtypes ,recombinants ,phylogenetic ,Medicine - Abstract
INTRODUCTIOM: High HIV-1 infection rates and genetic diversity especially in African population pose significant challenges in HIV-1 clinical management and drug design development. HIV-1 is a major health challenge in Kenya and causes mortality and morbidity in the country as well as straining the healthcare system and the economy. This study sought to identify HIV-1 genetic subtypes circulating in Teso, Western Kenya which borders the Republic of Uganda. METHODS: a cross sectional study was conducted in January 2019 to December 2019. Sequencing of the partial pol gene was carried out on 80 HIV positive individuals on antiretroviral therapy. Subtypes and recombinant forms were generated using the jumping profile hidden Markov model. Alignment of the sequences was done using ClustalW program and phylogenetic tree constructed using MEGA7 neighbor-joining method. RESULTS: sixty three samples were successful sequenced. In the analysis of these sequences, it was observed that HIV-1 subtype A1 was predominant 43 (68.3%) followed by D 8 (12.7%) and 1 (1.6%) each of C, G and B and inter-subtype recombinants A1-D 3 (4.8%), A1-B 2 (3.2%) and 1 (1.6%) each of A1-A2, A1-C, BC and BD. Phylogenetic analysis of these sequences showed close clustering of closely related and unrelated sequences with reference sequences. CONCLUSION: there was observed increased genetic diversity of HIV-1 subtypes which not only pose a challenge in disease control and management but also drug design and development. Therefore, there is need for continued surveillance to enhance future understanding of the geographical distribution and transmission patterns of the HIV epidemic.
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- 2021
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111. Genetic and Morphological Diversity of Indigenous Bradyrhizobium Nodulating Soybean in Organic and Conventional Family Farming Systems
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Nicholas Mawira Gitonga, Ezekiel Mugendi Njeru, Richard Cheruiyot, and John M. Maingi
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soybeans ,bradyrhizobia ,genetic diversity ,organic and conventional farming ,Kenya ,Nutrition. Foods and food supply ,TX341-641 ,Food processing and manufacture ,TP368-456 - Abstract
Organic farming systems are gaining popularity as agronomically and environmentally sound soil management strategies with potential to enhance soil microbial diversity and fertility, environmental quality and sustainable crop production. This work aimed at understanding the effect of organic and conventional farming on the diversity of soybean nodulating bradyrhizobia species. Field trapping of indigenous soybean Bradyrhizobium was done by planting promiscuous soybeans varieties SB16 and SC squire as well as non-promiscuous Gazelle in three organic and three conventional farms in Tharaka-Nithi County of Kenya. After 45 days of growth, 108 nodule isolates were obtained from the soybean nodules and placed into 13 groups based on their morphological characteristics. Genetic diversity was done by polymerase chain reaction (PCR) targeting 16S rDNA gene using universal primers P5-R and P3-F and sequencing was carried out using the same primer. High morphological and genetic diversity of the nodule isolates was observed in organic farms as opposed to conventional farms. There was little or no genetic differentiation between the nodule isolates from the different farms with the highest molecular variation (91.12%) being partitioned within populations as opposed to among populations (8.88%). All the isolates were identified as bradyrhizobia with close evolutionary ties with Bradyrhizobium japonicum and Bradyrhizobium yuanminense. Organic farming systems favor the proliferation of bradyrhizobia species and therefore a suitable environmentally friendly alternative for enhancing soybean production.
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- 2021
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112. Bradyrhizobium inoculation has a greater effect on soybean growth, production and yield quality in organic than conventional farming systems
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Nicholas Mawira Gitonga, Ezekiel Mugendi Njeru, Richard Cheruiyot, and John M. Maingi
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nitrogen fixation ,promiscuous ,nodulation ,soil fertility ,organic fertilizer ,Agriculture ,Food processing and manufacture ,TP368-456 - Abstract
Globally, organic farming and bradyrhizobia inoculation are gaining popularity as agronomically and environmentally sound soil management strategies with great potential to alleviate declining soil fertility, maintain environmental quality and enhance soybean production. However, the role of bradyrhizobia in organic farming system is poorly understood. Field experiment was conducted to evaluate the effects of bradyrhizobia inoculation and organic farming on growth parameters and yield quality of soybean varieties: SC squire, SB19 and Gazelle. The experimental treatments included native bradyrhizobia, commercial Bradyrhizobium japonicum, mixture of native + commercial bradyrhizobia and uninoculated control. The experimental design was a split-split plot, with three replications. The results demonstrated significant improvement in soybean nodule dry weight (NDW), shoot dry weight (SDW) and seed dry weight (SEDW) following bradyrhizobia inoculation. Remarkably, organic farming significantly out-performed conventional systems in nodulation, SDW and SEDW. Moreover, seed nutrient content differed depending on farming system; where nitrogen, phosphorus, potassium and organic carbon were higher in organic farming. Soybean varieties differed significantly on SDW, NDW and SEDW; where SC squire performed better than SB19 and Gazelle. The results demonstrate the importance of organic farming and bradyrhizobia inoculation in enhancing soil fertility, yield production and quality, a key step towards sustainable food production.
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- 2021
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113. Lopinavir plus nucleoside reverse-transcriptase inhibitors, lopinavir plus raltegravir, or lopinavir monotherapy for second-line treatment of HIV (EARNEST): 144-week follow-up results from a randomised controlled trial
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Agweng, E, Awio, P, Bakeinyaga, G, Isabirye, C, Kabuga, U, Kasuswa, S, Katuramu, M, Kiweewa, F, Kyomugisha, H, Lutalo, E, Mulima, D, Musana, H, Musitwa, G, Musiime, V, Ndigendawan, M, Namata, H, Nkalubo, J, Labejja, P Ocitti, Okello, P, Olal, P, Pimundu, G, Segonga, P, Ssali, F, Tamale, Z, Tumukunde, D, Namala, W, Byaruhanga, R, Kayiwa, J, Tukamushaba, J, Abunyang, S, Eram, D, Denis, O, Lwalanda, R, Mugarura, L, Namusanje, J, Nankya, I, Ndashimye, E, Nabulime, E, Senfuma, O, Bihabwa, G, Buluma, E, Elbireer, A, Kamya, D, Katwere, M, Kiggundu, R, Komujuni, C, Laker, E, Lubwama, E, Mambule, I, Matovu, J, Nakajubi, A, Nakku, J, Nalumenya, R, Namuyimbwa, L, Semitala, F, Wandera, B, Wanyama, J, Mugerwa, H, Ninsiima, E, Ssenkindu, T, Mwebe, S, Atwine, L, William, H, Katemba, C, Acaku, M, Ssebutinde, P, Kitizo, H, Kukundakwe, J, Naluguza, M, Ssegawa, K, Namayanja, Nsibuka, F, Tuhirirwe, P, Fortunate, M, Acen, J, Achidri, J, Amone, A, Chamai, M, Ditai, J, Kemigisa, M, Kiconco, M, Matama, C, Mbanza, D, Nambaziira, F, Odoi, M Owor, Rweyora, A, Tumwebaze, G, Kalanzi, H, Katabaazi, J, Kiyingi, A, Mbidde, M, Mugenyi, M, Okong, P, Senoga, I, Abwola, M, Baliruno, D, Bwomezi, J, Kasede, A, Mudoola, M, Namisi, R, Ssennono, F, Tuhirwe, S, Amone, G, Abach, J, Aciro, I, Arach, B, Kidega, P, Omongin, J, Ocung, E, Odong, W, Philliam, A, Alima, H, Ahimbisibwe, B, Atuhaire, E, Atukunda, F, Bekusike, G, Bulegyeya, A, Kahatano, D, Kamukama, S, Kyoshabire, J, Nassali, A, Mbonye, A, Naturinda, T M, Ndukukire, Nshabohurira, A, Ntawiha, H, Rogers, A, Tibyasa, M, Kiirya, S, Atwongyeire, D, Nankya, A, Draleku, C, Nakiboneka, D, Odoch, D, Lakidi, L, Ruganda, R, Abiriga, R, Mulindwa, M, Balmoi, F, Kafuma, S, Moriku, E, Reid, A, Chidziva, E, Musoro, G, Warambwa, C, Tinago, G, Mutsai, S, Phiri, M, Mudzingwa, S, Bafana, T, Masore, V, Moyo, C, Nhema, R, Chitongo, S, Heyderman, Robert, Kabanga, Lucky, Kaunda, Symon, Kudzala, Aubrey, Lifa, Linly, Mallewa, Jane, Moore, Mike, Mtali, Chrissie, Musowa, George, Mwimaniwa, Grace, Sikwese, Rosemary, Ziwoya, Milton, Chitete, H Chimbaka B, Kamanga, S, Makwakwa, T Kayinga E, Mbiya, R, Mlenga, M, Mphande, T, Mtika, C, Mushani, G, Ndhlovu, O, Ngonga, M, Nkhana, I, Nyirenda, R, Cheruiyot, P, Kwobah, C, Ekiru, W Lokitala, Mokaya, M, Mudogo, A, Nzioka, A, Tanui, M, Wachira, S, Wools-Kaloustian, K, Alipalli, P, Chikatula, E, Kipaila, J, Kunda, I, Lakhi, S, Malama, J, Mufwambi, W, Mulenga, L, Mwaba, P, Mwamba, E, Namfukwe, M, Kerukadho, E, Ngwatu, B, Birungi, J, Boles, J, Burke, A, Castle, L, Ghuman, S, Kendall, L, Tebbs, S, Whittle, J, Wilkes, H, Young, N, Spyer, M, Kapuya, C, Kyomuhendo, F, Kyakundi, D, Mkandawire, N, Mulambo, S, Senyonjo, S, Angus, B, Arenas-Pinto, A, Palfreeman, A, Post, F, Ishola, D, Arribas, J, Colebunders, R, Floridia, M, Giuliano, M, Mallon, P, Walsh, P, De Rosa, M, Rinaldi, E, Weller, I, Gilks, C, Kangewende, A, Luyirika, E, Miiro, F, Ojoo, S, Phiri, S, Wapakabulo, A, Peto, T, Matenga, J, Cloherty, G, van Wyk, J, Norton, M, Lehrman, S, Lamba, P, Malik, K, Rooney, J, Snowden, W, Villacian, J, Hakim, James G, Thompson, Jennifer, Kityo, Cissy, Hoppe, Anne, Kambugu, Andrew, van Oosterhout, Joep J, Lugemwa, Abbas, Siika, Abraham, Mwebaze, Raymond, Mweemba, Aggrey, Abongomera, George, Thomason, Margaret J, Easterbrook, Philippa, Mugyenyi, Peter, Walker, A Sarah, and Paton, Nicholas I
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- 2018
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114. Characterizing Real-World Particle-Bound Polycyclic Aromatic Hydrocarbon Emissions from Diesel-Fueled Construction Machines
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Narayan Babu Dhital, Lin-Chi Wang, Hsi-Hsien Yang, Nicholas Kiprotich Cheruiyot, and Che-Hsuan Lee
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gaseous pollutant ,mobile source emissions ,molecular diagnostic ratio ,non-road engine ,onboard emission measurement ,particulate matter ,Meteorology. Climatology ,QC851-999 - Abstract
This study employed an onboard emission measurement system to measure the real-world emission factors of particulate matter (PM), particle-bound polycyclic aromatic hydrocarbons (PAHs), and gaseous air pollutants for different types of diesel-fueled non-road construction machines operated inside confined spaces within a brick manufacturing factory located in Taiwan. To the best knowledge of the authors, this is the first study that reports real-world PM, PAH, and gaseous pollutant emission factors for non-road engines in Taiwan. The mean real-world fuel-specific emission factors of PM, carbon monoxide, total hydrocarbons, and nitric oxide were 0.712–1.17, 8.27–17.9, 3.04–5.77, and 38.1–96.8 g/kg-fuel, respectively, for the test machines. Likewise, mean ΣPAHs emission factors ranged from 157 to 230 μg/kg-fuel for three types of test machines. Further, the average emission of particle-bound PAH per unit PM emission ranged from 213 to 384 μg-PAH/g-PM. Among the analyzed PAHs, the medium-molecular weight (3- and 4-ring) compounds contributed to the largest share of particle-bound PAH emissions. However, in terms of Benzo[a]pyrene equivalent (BaPeq) toxicity, the high-molecular weight (5- and 6-ring) PAHs were more important, as they had the highest BaPeq toxic emission factors. This study provides detailed composition and emission factors of particle-bound PAHs in non-road diesel construction machine emissions, which may be useful as a chemical fingerprint for source apportionment studies.
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- 2022
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115. Reduced Expression of PD-1 in Circulating CD4+ and CD8+ Tregs Is an Early Feature of RRMS
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Maja Machcińska, Magdalena Kierasińska, Martyna Michniowska, Marta Maruszewska-Cheruiyot, Ludmiła Szewczak, Rafał Rola, Anna Karlińska, Michael Stear, and Katarzyna Donskow-Łysoniewska
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T cells ,suppressive markers ,cytokines ,relapsing–remitting multiple sclerosis ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Altered regulatory T cell (Treg) function could contribute to MS. The expression of activating and inhibitory receptors influences the activity of Tregs. Our aim was to investigate T cell phenotypes in relapsing–remitting MS (RRMS) patients at an early phase of the disease. We examined the influence of demographic parameters on the distribution of CD4+ and CD8+ T cell subclasses by generalized linear modeling. We also studied the expression of the following markers—CTLA-4, GITR, PD-1, FoxP3, Helios, CD28, CD62L, CD103—on T cell subsets from peripheral blood with a 14-color flow cytometry panel. We used an antibody array to define the profiles of 34 Th1/Th2/Th17 cytokines in the serum. Expression of PD-1 and GITR on CD4+ and CD8+ Tregs was decreased in RRMS patients. The proinflammatory factors IFN-γ, IL-17, IL-17F, TGFβ-1, TGFβ-3, IL-1SRII, IL-12 p40, sgp130, IL-6sR were significantly increased in RRMS patients. Therefore, a deficiency of PD-1 and GITR immune checkpoints on CD4+ and CD8+ Tregs is a feature of RRMS and might underlie impaired T cell control.
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- 2022
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116. Spatial Change in the Concentration of Multidimensional Poverty in Gauteng, South Africa: Evidence from Quality of Life Survey Data
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Katumba, Samy, Cheruiyot, Koech, and Mushongera, Darlington
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- 2019
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117. Soybean (Glycine max (L) Merrill) Root Growth and Nodulation Responses to Different Soil Moisture Regimes
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Mwamlima, Louis Hortensius, Ouma, Josephine Pamela, and Cheruiyot, Erick Kimutai
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- 2019
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118. Loss of ADAR1 in tumours overcomes resistance to immune checkpoint blockade
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Ishizuka, Jeffrey J., Manguso, Robert T., Cheruiyot, Collins K., Bi, Kevin, Panda, Arpit, Iracheta-Vellve, Arvin, Miller, Brian C., Du, Peter P., Yates, Kathleen B., Dubrot, Juan, Buchumenski, Ilana, Comstock, Dawn E., Brown, Flavian D., Ayer, Austin, Kohnle, Ian C., Pope, Hans W., Zimmer, Margaret D., Sen, Debattama R., Lane-Reticker, Sarah K., Robitschek, Emily J., Griffin, Gabriel K., Collins, Natalie B., Long, Adrienne H., Doench, John G., Kozono, David, Levanon, Erez Y., and Haining, W. Nicholas
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- 2019
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119. Signatures of Selection in Admixed Dairy Cattle in Tanzania
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Evans Kiptoo Cheruiyot, Rawlynce Cheruiyot Bett, Joshua Oluoch Amimo, Yi Zhang, Raphael Mrode, and Fidalis D. N. Mujibi
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selection signatures ,crossbred cattle ,admixture ,iHS ,XP-EHH ,pcadapt ,Genetics ,QH426-470 - Abstract
Multiple studies have investigated selection signatures in domestic cattle and other species. However, there is a dearth of information about the response to selection in genomes of highly admixed crossbred cattle in relation to production and adaptation to tropical environments. In this study, we evaluated 839 admixed crossbred cows sampled from two major dairy regions in Tanzania namely Rungwe and Lushoto districts, in order to understand their genetic architecture and detect genomic regions showing preferential selection. Animals were genotyped at 150,000 SNP loci using the Geneseek Genomic Profiler (GGP) High Density (HD) SNP array. Population structure analysis showed a large within-population genetic diversity in the study animals with a high degree of variation in admixture ranging between 7 and 100% taurine genes (dairyness) of mostly Holstein and Friesian ancestry. We explored evidence of selection signatures using three statistical methods (iHS, XP-EHH, and pcadapt). Selection signature analysis identified 108 candidate selection regions in the study population. Annotation of these regions yielded interesting genes potentially under strong positive selection including ABCG2, ABCC2, XKR4, LYN, TGS1, TOX, HERC6, KIT, PLAG1, CHCHD7, NCAPG, and LCORL that are involved in multiple biological pathways underlying production and adaptation processes. Several candidate selection regions showed an excess of African taurine ancestral allele dosage. Our results provide further useful insight into potential selective sweeps in the genome of admixed cattle with possible adaptive and productive importance. Further investigations will be necessary to better characterize these candidate regions with respect to their functional significance to tropical adaptations for dairy cattle.
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- 2018
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120. Local Linear Regression Estimator on the Boundary Correction in Nonparametric Regression Estimation
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Langat Reuben Cheruiyot
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Kernel estimators ,Nonparametric regression estimation ,Local linear regression ,Bias ,Variance ,Asymptotic mean integrated square error (AMISE) ,Probabilities. Mathematical statistics ,QA273-280 - Abstract
The precision and accuracy of any estimation can inform one whether to use or not to use the estimated values. It is the crux of the matter to many if not all statisticians. For this to be realized biases of the estimates are normally checked and eliminated or at least minimized. Even with this in mind getting a model that fits the data well can be a challenge. There are many situations where parametric estimation is disadvantageous because of the possible misspecification of the model. Under such circumstance, many researchers normally allow the data to suggest a model for itself in the technique that has become so popular in recent years called the nonparametric regression estimation. In this technique the use of kernel estimators is common. This paper explores the famous Nadaraya–Watson estimator and local linear regression estimator on the boundary bias. A global measure of error criterion-asymptotic mean integrated square error (AMISE) has been computed from simulated data at the empirical stage to assess the performance of the two estimators in regression estimation. This study shows that local linear regression estimator has a sterling performance over the standard Nadaraya–Watson estimator.
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- 2020
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121. Prevalence and risk factors of Schistosoma mansoni infection among children under two years of age in Mbita, Western Kenya.
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Miho Sassa, Evans A Chadeka, Ngetich B Cheruiyot, Mio Tanaka, Taeko Moriyasu, Satoshi Kaneko, Sammy M Njenga, Sharon E Cox, and Shinjiro Hamano
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Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
Despite growing evidence that infants and very young children can be infected with schistosomes, the epidemiological features and risk factors are not well described in this age group. We aimed to assess the prevalence of S. mansoni infection in children under two years of age from a population with a known high burden of infection in school-aged children and adults and thus inform the need for interventions in this potentially vulnerable age group. In a cross-sectional study in Mbita Sub-county, along the east coast of Lake Victoria, Western Kenya, we enrolled 361 children aged 6-23 months. The prevalence of S. mansoni infection was detected using the Kato-Katz stool examination and a point-of-care test for urinary circulating cathodic antigen (POC-CCA) (Rapid Medical Diagnostics, Pretoria, South Africa). Three-hundred and five (305) children had complete data of whom 276 (90.5%, 95%CI: 86.6-93.5) children were positive for S. mansoni by the POC-CCA test, while 11 (3.6%, 95%CI: 1.8-6.4) were positive by the Kato-Katz method. All Kato-Katz positive cases were also positive by the POC-CCA test. In multivariable analysis, only geographical area, Rusinga West (AOR = 7.1, 95%CI: 1.4-35.2, P = 0.02), was associated with S. mansoni infection using Kato-Katz test. Independent associations for POC-CCA positivity included age, (12-17 months vs 6-11 months; AOR = 7.8, 95%CI: 1.8-32.6, P = 0.002) and breastfeeding in the previous 24 hours (AOR = 3.4, 95%CI: 1.3-9.0, P = 0.009). We found a potentially very high prevalence of S. mansoni infection among children under two years of age based on POC-CCA test results in Mbita Sub-county, Kenya, which if confirmed strongly supports the need to include infants in public health strategies providing universal prophylactic treatment in high burden settings. Further research is required to determine the accuracy of diagnostic tools to detect light infection among very young children and possible long-term health impacts.
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- 2020
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122. A seven-year surveillance of epidemiology of malaria reveals travel and gender are the key drivers of dispersion of drug resistant genotypes in Kenya
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Moureen Maraka, Hoseah M. Akala, Asito S. Amolo, Dennis Juma, Duke Omariba, Agnes Cheruiyot, Benjamin Opot, Charles Okello Okudo, Edwin Mwakio, Gladys Chemwor, Jackline A. Juma, Raphael Okoth, Redemptah Yeda, and Ben Andagalu
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Malaria ,Drug resistance ,Chloroquine ,Gender ,Travel ,Plasmodium falciparum ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Malaria drug resistance is a global public health concern. Though parasite mutations have been associated with resistance, other factors could influence the resistance. A robust surveillance system is required to monitor and help contain the resistance. This study established the role of travel and gender in dispersion of chloroquine resistant genotypes in malaria epidemic zones in Kenya. A total of 1,776 individuals presenting with uncomplicated malaria at hospitals selected from four malaria transmission zones in Kenya between 2008 and 2014 were enrolled in a prospective surveillance study assessing the epidemiology of malaria drug resistance patterns. Demographic and clinical information per individual was obtained using a structured questionnaire. Further, 2 mL of blood was collected for malaria diagnosis, parasitemia quantification and molecular analysis. DNA extracted from dried blood spots collected from each of the individuals was genotyped for polymorphisms in Plasmodium falciparum chloroquine transporter gene (Pfcrt 76), Plasmodium falciparum multidrug resistant gene 1 (Pfmdr1 86 and Pfmdr1 184) regions that are putative drug resistance genes using both conventional polymerase chain reaction (PCR) and real-time PCR. The molecular and demographic data was analyzed using Stata version 13 (College Station, TX: StataCorp LP) while mapping of cases at the selected geographic zones was done in QGIS version 2.18. Chloroquine resistant (CQR) genotypes across gender revealed an association with chloroquine resistance by both univariate model (p = 0.027) and by multivariate model (p = 0.025), female as reference group in both models. Prior treatment with antimalarial drugs within the last 6 weeks before enrollment was associated with carriage of CQR genotype by multivariate model (p = 0.034). Further, a significant relationship was observed between travel and CQR carriage both by univariate model (p = 0.001) and multivariate model (p = 0.002). These findings suggest that gender and travel are significantly associated with chloroquine resistance. From a gender perspective, males are more likely to harbor resistant strains than females hence involved in strain dispersion. On the other hand, travel underscores the role of transport network in introducing spread of resistant genotypes, bringing in to focus the need to monitor gene flow and establish strategies to minimize the introduction of resistance strains by controlling malaria among frequent transporters.
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- 2020
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123. Leaf Gas Exchange and Root Nodulation Respond to Planting Density in Soybean [Glycine max (L) Merrill]
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Louis Hortensius Mwamlima, Josephine Pamela Ouma, and Erick Kimutai Cheruiyot
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Agriculture (General) ,S1-972 - Abstract
Planting density influences structural characteristics and affects mineral nutrient acquisition, irradiance and photosynthesis amongst plants. An experiment was conducted to determine the effect of planting density on leaf gas exchange and nodulation of soybean (Glycine max (L) Merrill). The experiment was conducted as a randomized complete block design (RCBD) in a 5 by 2 factorial treatment arrangement and was replicated three times. Planting density (10, 12, 20, 40, and 80 plants m−2) and soybean varieties (EAI 3600 and DPSB 19) were first and second factors, respectively. Collected data were subjected to analysis of variance in GENSTAT. Significantly different treatment means were separated using Tukey’s honestly significant difference test at 0.05 significance level. Higher planting density significantly increased (p
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- 2020
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124. Prevalence and Intensity of Intestinal Helminth Infections in Preschool Pupils in Lugari Subcounty, Kakamega County, Kenya
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Daniel Kevin Werunga, Elizabeth Nanjala Omukunda, and Jackson Cheruiyot Korir
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Infectious and parasitic diseases ,RC109-216 - Abstract
Intestinal helminths cause anaemia, malnutrition, indigestion disorders, retarded growth, and low mental abilities in pupils. About 1.5 billion are infected globally. Intestinal helminth infections are caused by Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, Enterobius vermicularis, Ancylostoma duodenale, and Necator americanus. Lugari Subcounty has poor sanitation and inadequate clean water. This study determined the prevalence of intestinal helminth infections in preschool pupils in Lugari Subcounty. A stratified multistage cluster experimental design was used. Sampling was carried out in four wards: Lumakanda, Lugari, Luandeti, and Chekalini. Preschool pupils of either gender were selected randomly. Written consents and verbal assent were obtained from parents or guardians and preschool pupils, respectively. Questionnaires were administered in order to collect sociodemographic data. Stool samples were collected and tested for the presence of eggs using the standard Kato-Katz technique. Prevalence rate and prevalence ratio were calculated as the percentage of infected preschool pupils among the total number of preschool pupils examined. Preschool pupils positive with helminths were treated freely, and a follow-up screening was conducted three months after treatment. Approval of the study was sought from the Masinde Muliro University of Science and Technology Institutional Ethical Review Board (MMUST IRB). The overall prevalence of intestinal helminths was 12.3%. Only one species, Ascaris lumbricoides, was identified. Statistical tests were carried out at a 5% significance level (p
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- 2020
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125. Selective sweeps and genetic lineages of Plasmodium falciparum multi-drug resistance (pfmdr1) gene in Kenya
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Peninah Muiruri, Denis W. Juma, Luicer A. Ingasia, Lorna J. Chebon, Benjamin Opot, Bidii S. Ngalah, Jelagat Cheruiyot, Ben Andagalu, Hoseah M. Akala, Venny C. S. Nyambati, Joseph K. Ng’ang’a, and Edwin Kamau
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Soft selective sweeps ,Genetic lineages ,Artemisinin resistance ,Arctic medicine. Tropical medicine ,RC955-962 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background There are concerns that resistance to artemisinin-based combination therapy might emerge in Kenya and sub-Saharan Africa (SSA) in the same pattern as was with chloroquine and sulfadoxine–pyrimethamine. Single nucleotide polymorphisms (SNPs) in critical alleles of pfmdr1 gene have been associated with resistance to artemisinin and its partner drugs. Microsatellite analysis of loci flanking genes associated with anti-malarial drug resistance has been used in defining the geographic origins, dissemination of resistant parasites and identifying regions in the genome that have been under selection. Methods This study set out to investigate evidence of selective sweep and genetic lineages in pfmdr1 genotypes associated with the use of artemether–lumefantrine (AL), as the first-line treatment in Kenya. Parasites (n = 252) from different regions in Kenya were assayed for SNPs at codons 86, 184 and 1246 and typed for 7 neutral microsatellites and 13 microsatellites loci flanking (± 99 kb) pfmdr1 in Plasmodium falciparum infections. Results The data showed differential site and region specific prevalence of SNPs associated with drug resistance in the pfmdr1 gene. The prevalence of pfmdr1 N86, 184F, and D1246 in western Kenya (Kisumu, Kericho and Kisii) compared to the coast of Kenya (Malindi) was 92.9% vs. 66.7%, 53.5% vs. to 24.2% and 96% vs. to 87.9%, respectively. The NFD haplotype which is consistent with AL selection was at 51% in western Kenya compared to 25% in coastal Kenya. Conclusion Selection pressures were observed to be different in different regions of Kenya, especially the western region compared to the coastal region. The data showed independent genetic lineages for all the pfmdr1 alleles. The evidence of soft sweeps in pfmdr1 observed varied in direction from one region to another. This is challenging for malaria control programs in SSA which clearly indicate effective malaria control policies should be based on the region and not at a country wide level.
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- 2018
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126. Helminth therapy: Advances in the use of parasitic worms against Inflammatory Bowel Diseases and its challenges
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Maruszewska-Cheruiyot M., Donskow-Łysoniewska K., and Doligalska M.
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helminth therapy ,heligmosomoides polygyrus ,inflammatory bowel diseases ,ulcerative colitis ,Microbiology ,QR1-502 - Abstract
Development of modern medicine and better living conditions in the 20th century helped in reducing a number of cases of infectious diseases. During the same time, expansion of autoimmunological disorders was noticed. Among other are Inflammatory Bowel Diseases (IBD) including ulcerative colitis and Crohn’s disease which are chronic and relapsing inflammation of the gastrointestinal tract. Absence of effective treatment in standard therapies effects the search for alternative opportunities. As per hygienic hypothesis increasing number of cases of autoimmune diseases is as a result of reduced exposure to pathogens, especially parasites. Thus, one of the promising remedial acts against IBD and other allergic and autoimmune disorders is “helminth therapy”. Cure with helminths seems to be the most effective therapy of IBD currently proposed. Helminth therapy focuses on advantageous results that have been obtained from the clinical trials, but its mechanisms are still unclear. Explanation of this phenomenon would help to develop new drugs against IBD based on helminth immunomodulatory molecules.
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- 2018
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127. Synergism in Antiplasmodial Activities of Artemether and Lumefantrine in Combination with Securidaca longipedunculata Fresen (Polygalaceae)
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Douglas O. Ochora, Esezah K. Kakudidi, Jane Namukobe, Perpetua Ipulet, Dancan M. Wakoli, Winnie Okore, Edwin W. Mwakio, Redempthah A. Yeda, Agnes C. Cheruiyot, Dennis W. Juma, Ben Andagalu, Amanda L. Roth, Bernhards R. Ogutu, Abiy Yenesew, and Hoseah M. Akala
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combination ,malaria ,plasmodium falciparum ,Securidaca longipedunculata ,synergism ,Botany ,QK1-989 - Abstract
Malaria is the most lethal parasitic disease in the world. The frequent emergence of resistance by malaria parasites to any drug is the hallmark of sustained malaria burden. Since the deployment of artemisinin-based combination therapies (ACTs) it is clear that for a sustained fight against malaria, drug combination is one of the strategies toward malaria elimination. In Sub-Saharan Africa where malaria prevalence is the highest, the identification of plants with a novel mechanism of action that is devoid of cross-resistance is a feasible strategy in drug combination therapy. Thus, artemether and lumefantrine were separately combined and tested with extracts of Securidaca longipedunculata, a plant widely used to treat malaria, at fixed extract–drug ratios of 4:1, 3:1, 1:1, 1:2, 1:3, and 1:4. These combinations were tested for antiplasmodial activity against three strains of Plasmodium falciparum (W2, D6, and DD2), and seven field isolates that were characterized for molecular and ex vivo drug resistance profiles. The mean sum of fifty-percent fractional inhibition concentration (FIC50) of each combination and singly was determined. Synergism was observed across all fixed doses when roots extracts were combined with artemether against D6 strain (FIC50 0.403 ± 0.068) and stems extract combined with lumefantrine against DD2 strain (FIC50 0.376 ± 0.096) as well as field isolates (FIC50 0.656 ± 0.067). Similarly, synergism was observed in all ratios when leaves extract were combined with lumefantrine against W2 strain (FIC50 0.456 ± 0.165). Synergism was observed in most combinations indicating the potential use of S. longipedunculata in combination with artemether and lumefantrine in combating resistance.
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- 2021
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128. Comparing Risks to Journalism: Media Criticism in the Digital Hate
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Cheruiyot, David
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AbstractThis study examines digital media criticism—publicly shared evaluations and judgements of journalistic text and actors on various digital platforms—as a risk to journalism. It specifically interrogates how journalists negotiate the diverse nature of criticism in digital spaces and in a comparative context. Through qualitative interviews with practising journalists, the paper identifies the following four main journalistic responses to digital media criticism: consolidation (ringfencing journalistic discourse); filtering (cleaning up journalistic discourse); rationalisation (acknowledging criticism or non-responses) and counter-discourse (counteracting anti-media discourses). These responses, referred to as forms of digital discursive resistance,show that journalists are both defensive against and accommodating of risks to journalistic authority, but usually aim to reinforce and expand journalistic discourse in digital spaces.
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- 2024
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129. Nucleoside reverse-transcriptase inhibitor cross-resistance and outcomes from second-line antiretroviral therapy in the public health approach: an observational analysis within the randomised, open-label, EARNEST trial
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Agweng, E, Awio, P, Bakeinyaga, G, Isabirye, C, Kabuga, U, Kasuswa, S, Katuramu, M, Kityo, C, Kiweewa, F, Kyomugisha, H, Lutalo, E, Mugyenyi, P, Mulima, D, Musana, H, Musitwa, G, Musiime, V, Ndigendawan, M, Namata, H, Nkalubo, J, Labejja, P Ocitti, Okello, P, Olal, P, Pimundu, G, Segonga, P, Ssali, F, Tamale, Z, Tumukunde, D, Namala, W, Byaruhanga, R, Kayiwa, J, Tukamushaba, J, Abunyang, S, Eram, D, Denis, O, Lwalanda, R, Mugarura, L, Namusanje, J, Nankya, I, Ndashimye, E, Nabulime, E, Senfuma, O, Bihabwa, G, Buluma, E, Easterbrook, P, Elbireer, A, Kambugu, A, Kamya, D, Katwere, M, Kiggundu, R, Komujuni, C, Laker, E, Lubwama, E, Mambule, I, Matovu, J, Nakajubi, A, Nakku, J, Nalumenya, R, Namuyimbwa, L, Semitala, F, Wandera, B, Wanyama, J, Mugerwa, H, Lugemwa, A, Ninsiima, E, Ssenkindu, T, Mwebe, S, Atwine, L, William, H, Katemba, C, Acaku, M, Ssebutinde, P, Kitizo, H, Kukundakwe, J, Naluguza, M, Ssegawa, K, Namayanja, Nsibuka, F, Tuhirirwe, P, Fortunate, M, Acen, J, Achidri, J, Amone, A, Chamai, M, Ditai, J, Kemigisa, M, Kiconco, M, Matama, C, Mbanza, D, Nambaziira, F, Odoi, M Owor, Rweyora, A, Tumwebaze, G, Kalanzi, H, Katabaazi, J, Kiyingi, A, Mbidde, M, Mugenyi, M, Mwebaze, R, Okong, P, Senoga, I, Abwola, M, Baliruno, D, Bwomezi, J, Kasede, A, Mudoola, M, Namisi, R, Ssennono, F, Tuhirwe, S, Abongomera, G, Amone, G, Abach, J, Aciro, I, Arach, B, Kidega, P, Omongin, J, Ocung, E, Odong, W, Philliam, A, Alima, H, Ahimbisibwe, B, Atuhaire, E, Atukunda, F, Bekusike, G, Bulegyeya, A, Kahatano, D, Kamukama, S, Kyoshabire, J, Nassali, A, Mbonye, A, Naturinda, T M, Ndukukire, Nshabohurira, A, Ntawiha, H, Rogers, A, Tibyasa, M, Kiirya, S, Atwongyeire, D, Nankya, A, Draleku, C, Nakiboneka, D, Odoch, D, Lakidi, L, Ruganda, R, Abiriga, R, Mulindwa, M, Balmoi, F, Kafuma, S, Moriku, E, Hakim, J, Reid, A, Chidziva, E, Musoro, G, Warambwa, C, Tinago, G, Mutsai, S, Phiri, M, Mudzingwa, S, Bafana, T, Masore, V, Moyo, C, Nhema, R, Chitongo, S, Heyderman, Robert, Kabanga, Lucky, Kaunda, Symon, Kudzala, Aubrey, Lifa, Linly, Mallewa, Jane, Moore, Mike, Mtali, Chrissie, Musowa, George, Mwimaniwa, Grace, Sikwese, Rosemary, van Oosterhout, Joep, Ziwoya, Milton, Chimbaka, H, Chitete, B, Kamanga, S, Makwakwa, T Kayinga E, Mbiya, R, Mlenga, M, Mphande, T, Mtika, C, Mushani, G, Ndhlovu, O, Ngonga, M, Nkhana, I, Nyirenda, R, Cheruiyot, P, Kwobah, C, Ekiru, W Lokitala, Mokaya, M, Mudogo, A, Nzioka, A, Siika, A, Tanui, M, Wachira, S, Wools-Kaloustian, K, Alipalli, P, Chikatula, E, Kipaila, J, Kunda, I, Lakhi, S, Malama, J, Mufwambi, W, Mulenga, L, Mwaba, P, Mwamba, E, Mweemba, A, Namfukwe, M, Kerukadho, E, Ngwatu, B, Birungi, J, Paton, N, Boles, J, Burke, A, Castle, L, Ghuman, S, Kendall, L, Hoppe, A, Tebbs, S, Thomason, M, Thompson, J, Walker, S, Whittle, J, Wilkes, H, Young, N, Spyer, M, Kapuya, C, Kyomuhendo, F, Kyakundi, D, Mkandawire, N, Mulambo, S, Senyonjo, S, Angus, B, Arenas-Pinto, A, Palfreeman, A, Post, F, Ishola, D, Arribas, J, Colebunders, R, Floridia, M, Giuliano, M, Mallon, P, Walsh, P, De Rosa, M, Rinaldi, E, Weller, I, Gilks, C, Kangewende, A, Luyirika, E, Miiro, F, Mwamba, P, Ojoo, S, Phiri, S, van Oosterhout, J, Wapakabulo, A, Peto, T, French, N, Matenga, J, Cloherty, G, van Wyk, J, Norton, M, Lehrman, S, Lamba, P, Malik, K, Rooney, J, Snowden, W, Villacian, J, Paton, Nicholas I, Kityo, Cissy, Thompson, Jennifer, Nankya, Immaculate, Bagenda, Leonard, Hoppe, Anne, Hakim, James, Kambugu, Andrew, van Oosterhout, Joep J, Kiconco, Mary, Bertagnolio, Silvia, Easterbrook, Philippa J, Mugyenyi, Peter, and Walker, A Sarah
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- 2017
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130. Hydrocyanic acid potential in sorghums reduce with maturity and increase with temperature.
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Ouma, Lilian, Cheruiyot, Erick, and Ogendo, Joshua
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Sorghum [Sorghum bicolor (L.) Moench] is an important fodder; however, its use is limited by the presence of dhurrin that breaks down to yield hydrocyanic acid (HCN), which is toxic to livestock. Twenty sorghum cultivars were evaluated in two sites in the year 2019 and three sites in the year 2020 (Egerton, Rongai, and Marigat representing cool, warm, and hot regions in Kenya) in randomized complete block design with three replications and plants sampled at booting and dough growth stages to measure hydrocyanic acid potential (HCN‐p) of sorghum. Analysis of variance revealed significant effects of both two‐way and higher‐order interactions of cultivar (G), location (L), and stage (S) by season (Y), that is, G × L × S, G × L × Y, G × Y, G × S, L × S, and L × Y. Main factors (cultivar, location, and stage) also have a significant effect on HCN‐p of sorghum. IESV9110 had the highest HCN‐p (146.09 mg kg), while EST 37 had the lowest HCN‐p (83.97 mg kg−1) across all locations. There was a progressive increase in HCN‐p from a cooler region to a warmer and a hotter region, respectively. HCN‐p on average was 47.8% less at Egerton University than at Marigat, 35.4% higher in Marigat compared to Rongai, and 14.41% less in Rongai compared to Egerton. Sorghum sampled at booting stage had averagely higher HCN‐p (133.94 mg kg−1) compared to dough stage (91.31 mg kg−1). The average air temperatures during the growing seasons were 24–27.3°C, 21.8–22.9°C, and 16.5–19.5°C for Marigat, Rongai, and Egerton, respectively. Growing temperature needs consideration when recommending fodder sorghum with low HCN‐p. Core Ideas: High growing temperature increases hydrocyanic acid potential (HCN‐p) of sorghum.Genotype and developmental stage affect hydrocyanic acid potential of sorghum.Plant height and days to 50% heading correlate with hydrocyanic acid in sorghum. [ABSTRACT FROM AUTHOR]
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- 2024
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131. Correction to: Rise and fall of total mesorectal excision with lateral pelvic lymphadenectomy for rectal cancer: an updated systematic review and meta-analysis of 11,366 patients
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Anania, Gabriele, Davies, Richard Justin, Arezzo, Alberto, Bagolini, Francesco, D’Andrea, Vito, Graziosi, Luigina, Di Saverio, Salomone, Popivanov, Georgi, Cheruiyot, Isaac, Cirocchi, Roberto, and Donini, Annibale
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- 2021
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132. Genetic and economic efficiency of integrating reproductive technologies in cattle breeding programme in Kenya
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Gicheha, Mathew Gitau, Akidiva, Indusa Clinton, and Cheruiyot, Ronald Yosei
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- 2019
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133. Surgical anatomy of the external branch of the superior laryngeal nerve: a systematic review and meta-analysis
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Cheruiyot, Isaac, Kipkorir, Vincent, Henry, Brandon Michael, Munguti, Jeremiah, Cirocchi, Roberto, Odula, Paul, Wong, Linda M., Olabu, Beda, and Walocha, Jerzy
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- 2018
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134. Varroa-specific hygienic behavior of Apis mellifera scutellata in Kenya
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Cheruiyot, Sammy Kiprotich, Lattorff, H. Michael G., Kahuthia-Gathu, Ruth, Mbugi, Jenard Patrick, and Muli, Elliud
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- 2018
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135. Organizational leadership perspectives in implementation of the One Health approach: A case of the Zoonotic Disease Unit and core One Health implementers in Kenya
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Thomas Manyibe Nyariki, Mathew Muturi, Athman Mwatondo, Michael Cheruiyot, Harry Oyas, Vincent Obanda, Francis Gakuya, Rees Murithi Mbabu, and Mercy Muthoni Mugambi
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cross-sectoral collaboration ,One Health approach ,organizational leadership ,sensitization ,Medicine ,Medicine (General) ,R5-920 - Abstract
Aim: This study examined organizational leadership as a cross-sectoral collaboration factor in the implementation of the One Health (OH) approach using Kenya’s Zoonotic Disease Unit and its core OH implementers as an example. Materials and Method: The study used a mixed methods research design. A semi-structured questionnaire was administered to 71 respondents, and key informants were interviewed using an interview guide. All the seven key informants and 53 (74%) of the respondents participated in the study. Data were checked for consistency, coded, entered into the Statistical Package for the Social Sciences, and analyzed using descriptive and correlational statistics. Interview data were transcribed and analyzed thematically. Results: From the analysis, 41/53 (77.2%) of the respondents were senior personnel, 51/53 (85%) of them had worked for 5 years and above in their organizations, and 38/53 (71.7%) had at least a Master’s degree. The study established that although most leaders in the organizations had embraced the OH approach, they were not actively involved in its implementation due to constraints such as inadequate funding. There were moderate and statistically significant positive correlations between participation in leadership roles in implementing the OH approach and the level of awareness (Rs (51)=0.54, p
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- 2017
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136. Yield-phenology relations and water use efficiency of maize (Zea mays L.) in ridge-furrow mulching system in semiarid east African Plateau
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Fei Mo, Jian-Yong Wang, Feng-Min Li, Simon N. Nguluu, Hong-Xu Ren, Hong Zhou, Jian Zhang, Charles W. Kariuki, Patrick Gicheru, Levis Kavagi, Wesly K. Cheruiyot, and You-Cai Xiong
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Medicine ,Science - Abstract
Abstract Yield-phenology relation is a critical issue affecting rainfed maize field productivity in semiarid east African Plateau (EAP). We first introduced Chinese ridge-furrow mulching (RFM) system to EAP, using three maize cultivars with early-, mid- and late-maturing traits as test materials. A two-year field experiment was conducted in a semiarid farm of Kenya from 2012 to 2013. Three treatments were designed: alternative ridge and furrow with transparent plastic mulching (FT), with black plastic mulching (FB) and without mulching (CK). We found that FT and FB significantly increased soil moisture and accelerated crop maturity across two growing seasons. Leaf area and shoot biomass were increased by 30.2% and 67.5% in FT, 35.2% and 73.5% in FB, respectively, compared with CK. Grain yield, water use efficiency and economic output were increased by 55.6%, 57.5% and 26.7% in FT, and 50.8%, 53.3% and 19.8% in FB, respectively. Optimal yield and economic benefit were observed in late-maturing cultivar due to increased topsoil temperature in FT in 2012 (cool), and in early-maturing cultivar owing to cooling effect in FB in 2013 (warm). Our study suggested RFM system, combined with crop phenology selection, be a promising strategy to boost maize productivity and profitability in semiarid EAP.
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- 2017
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137. Medroxyprogesterone acetate alters the vaginal microbiota and microenvironment in women and increases susceptibility to HIV-1 in humanized mice
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Jocelyn M. Wessels, Julie Lajoie, Maeve I. J. Hay Cooper, Kenneth Omollo, Allison M. Felker, Danielle Vitali, Haley A. Dupont, Philip V. Nguyen, Kristen Mueller, Fatemeh Vahedi, Joshua Kimani, Julius Oyugi, Juliana Cheruiyot, John N. Mungai, Alexandre Deshiere, Michel J. Tremblay, Tony Mazzulli, Jennifer C. Stearns, Ali A. Ashkar, Keith R. Fowke, Michael G. Surette, and Charu Kaushic
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dmpa ,glycogen ,amylase ,polymicrobial vaginal microbiota ,humanized mouse ,Medicine ,Pathology ,RB1-214 - Abstract
The hormonal contraceptive medroxyprogesterone acetate (MPA) is associated with increased risk of human immunodeficiency virus (HIV), via incompletely understood mechanisms. Increased diversity in the vaginal microbiota modulates genital inflammation and is associated with increased HIV-1 acquisition. However, the effect of MPA on diversity of the vaginal microbiota is relatively unknown. In a cohort of female Kenyan sex workers, negative for sexually transmitted infections (STIs), with Nugent scores
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- 2019
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138. Adsorption of toxic crystal violet dye using coffee husks: Equilibrium, kinetics and thermodynamics study
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Gilbert K. Cheruiyot, Wycliffe C. Wanyonyi, Joyce J. Kiplimo, and Esther N. Maina
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Science - Abstract
Crystal violet (CV) dye is a water-soluble, toxic, recalcitrant organic dye that causes severe health problems and environment pollution. The current study assesses the potential of Waste Coffee Husks (WCH) in adsorption of crystal violet (CV) dye. Batch experiments were designed to determine the effect of pH, dye concentration, adsorbent dose, and contact time in dye removal. Result revealed that removal of CV was highly favored by lower temperatures and acidic medium. Dye removal per unit mass of WCH increased with increase in contact time, dye concentration and surface area. At ambient temperature, the maximum adsorption efficiency of up to 94% was achieved within 10 min at pH 3. Adsorption capacity of Waste Coffee Husks was found to be 12.0360 mg/l for initial dye concentration of 12.2394 mg/l at 25 °C. The experimental data followed pseudo-second-order kinetic models indicating that dye adsorption was controlled by chemical process involving valence forces through sharing or exchange of electrons between CV dye and WCH. Adsorption equilibrium data followed Freundlich and Langmuir isotherm models. Gibbs free energy (∆G°) of the system showed increasing spontaneity with temperatures while positive entropy value (∆S°) implied random disorder of molecules featured at solution/solid interface. Negative enthalpy value (∆H°) confirmed exothermic nature of this adsorption process. These results demonstrate that Waste Coffee Husk are cost-effective, eco-friendly and low-cost bio renewable material for dye removal in industrial effluents. Keywords: Adsorption, Crystal violet dye, Waste coffee husk, Isotherms, Kinetics, Equilibrium
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- 2019
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139. Effects of single and integrated water, sanitation, handwashing, and nutrition interventions on child soil-transmitted helminth and Giardia infections: A cluster-randomized controlled trial in rural Kenya.
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Amy J Pickering, Sammy M Njenga, Lauren Steinbaum, Jenna Swarthout, Audrie Lin, Benjamin F Arnold, Christine P Stewart, Holly N Dentz, MaryAnne Mureithi, Benard Chieng, Marlene Wolfe, Ryan Mahoney, Jimmy Kihara, Kendra Byrd, Gouthami Rao, Theodora Meerkerk, Priscah Cheruiyot, Marina Papaiakovou, Nils Pilotte, Steven A Williams, John M Colford, and Clair Null
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Medicine - Abstract
BackgroundHelminth and protozoan infections affect more than 1 billion children globally. Improving water quality, sanitation, handwashing, and nutrition could be more sustainable control strategies for parasite infections than mass drug administration, while providing other quality of life benefits.Methods and findingsWe enrolled geographic clusters of pregnant women in rural western Kenya into a cluster-randomized controlled trial (ClinicalTrials.gov NCT01704105) that tested 6 interventions: water treatment, improved sanitation, handwashing with soap, combined water treatment, sanitation, and handwashing (WSH), improved nutrition, and combined WSH and nutrition (WSHN). We assessed intervention effects on parasite infections by measuring Ascaris lumbricoides, Trichuris trichiura, hookworm, and Giardia duodenalis among children born to the enrolled pregnant women (index children) and their older siblings. After 2 years of intervention exposure, we collected stool specimens from 9,077 total children aged 2 to 15 years in 622 clusters, including 2,346 children in an active control group (received household visits but no interventions), 1,117 in the water treatment arm, 1,160 in the sanitation arm, 1,141 in the handwashing arm, 1,064 in the WSH arm, 1,072 in the nutrition arm, and 1,177 in the WSHN arm. In the control group, 23% of children were infected with A. lumbricoides, 1% with T. trichiura, 2% with hookworm, and 39% with G. duodenalis. The analysis included 4,928 index children (median age in years: 2) and 4,149 older siblings (median age in years: 5); study households had an average of 5 people, 90% had dirt floors. Compared to the control group, Ascaris infection prevalence was lower in the water treatment arm (prevalence ratio [PR]: 0.82 [95% CI 0.67, 1.00], p = 0.056), the WSH arm (PR: 0.78 [95% CI 0.63, 0.96], p = 0.021), and the WSHN arm (PR: 0.78 [95% CI 0.64, 0.96], p = 0.017). We did not observe differences in Ascaris infection prevalence between the control group and the arms with the individual interventions sanitation (PR: 0.89 [95% CI 0.73, 1.08], p = 0.228), handwashing (PR: 0.89 [95% CI 0.73, 1.09], p = 0.277), or nutrition (PR: 86 [95% CI 0.71, 1.05], p = 0.148). Integrating nutrition with WSH did not provide additional benefit. Trichuris and hookworm were rarely detected, resulting in imprecise effect estimates. No intervention reduced Giardia. Reanalysis of stool samples by quantitative polymerase chain reaction confirmed the reductions in Ascaris infections measured by microscopy in the WSH and WSHN groups. Trial limitations included imperfect uptake of targeted intervention behaviors, limited power to detect effects on rare parasite infections, and that it was not feasible to blind participants and sample collectors to treatment status. However, lab technicians and data analysts were blinded to treatment status. The trial was funded by the Bill & Melinda Gates Foundation and the United States Agency for International Development.ConclusionsIntegration of improved water quality, sanitation, and handwashing could contribute to sustainable control strategies for Ascaris infections, particularly in similar settings with recent or ongoing deworming programs. Combining nutrition with WSH did not provide further benefits, and water treatment alone was similarly effective to integrated WSH. Our findings provide new evidence that drinking water should be given increased attention as a transmission pathway for Ascaris.Trial registrationClinicalTrials.gov NCT01704105.
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- 2019
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140. Performance Evaluation of Highly Admixed Tanzanian Smallholder Dairy Cattle Using SNP Derived Kinship Matrix
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Fidalis D. N. Mujibi, James Rao, Morris Agaba, Devotha Nyambo, Evans K. Cheruiyot, Absolomon Kihara, Yi Zhang, and Raphael Mrode
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SNP ,dairy ,performance ,cluster ,smallholder ,admixture ,Genetics ,QH426-470 - Abstract
The main purpose of this study was to understand the type of dairy cattle that can be optimally used by smallholder farmers in various production environments such that they will maximize their yields without increasing the level of inputs. Anecdotal evidence and previous research suggests that the optimal level of taurine inheritance in crossbred animals lies between 50 and 75% when considering total productivity in tropical management clusters. We set out to assess the relationship between breed composition and productivity for various smallholder production systems in Tanzania. We surveyed 654 smallholder dairy households over a 1-year period and grouped them into production clusters. Based on supplementary feeding, milk productivity and sale as well as household wealth status four clusters were described: low-feed–low-output subsistence, medium-feed–low-output subsistence, maize germ intensive semi-commercial and feed intensive commercial management clusters. About 839 crossbred cows were genotyped at approximately 150,000 single nucleotide polymorphism (SNP) loci and their breed composition determined. Percentage dairyness (proportion of genes from international dairy breeds) was estimated through admixture analysis with Holstein, Friesian, Norwegian Red, Jersey, Guernsey, N’Dama, Gir, and Zebu as references. Four breed types were defined as RED–GUE (Norwegian Red/Friesian–Guernsey; Norwegian Red/Friesian–Jersey), RED–HOL (Norwegian Red/Friesian–Holstein), RED–Zebu (Norwegian Red/Friesian–Zebu), Zebu–RED (Zebu–Norwegian Red/Friesian) based on the combination of breeds that make up the top 76% breed composition. A fixed regression model using a genomic kinship matrix was used to analyze milk yield records. The fitted model accounted for year-month-test-date, parity, age, breed type and the production clusters as fixed effects in the model in addition to random effects of animal and permanent environment effect. Results suggested that RED–Zebu breed type with dairyness between 75 and 85% is the most appropriate for a majority of smallholder management clusters. Additionally, for farmers in the feed intensive management group, animals with a Holstein genetic background with at least 75% dairy composition were the best performing. These results indicate that matching breed type to production management group is central to maximizing productivity in smallholder systems. The findings from this study can serve as a basis to inform the development of the dairy sector in Tanzania and beyond.
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- 2019
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141. Genetic Variability of Agronomic Traits as Potential Indicators of Drought Tolerance in Common Beans (Phaseolus vulgaris L.)
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Charles Langat, Omwoyo Ombori, Philip Leley, David Karanja, Richard Cheruiyot, Moses Gathaara, and Benard Masila
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Agriculture (General) ,S1-972 - Abstract
Sixteen progeny lines of common beans obtained from single crosses made between two parents, GLP2 and KAT B1, were grown in randomized complete block design in a rainout shelter at the Agricultural and Mechanization Research Institute, Machakos, Kenya. The experiment was conducted to study inheritance of traits associated with drought stress adaptation and to establish if significant variation for those traits was existing in order to carry out selection for drought tolerance. The calculated mean values were used to estimate heritability, genetic advance, and correlation study for each trait. Water stress had a significant (p≤0.01) effect on the number of pods per plant, grains per plant, 100-seed weight, and yield per plant. The highest values for genotypic coefficient of variation (36.11%) and phenotypic coefficient of variation (36.70%) were recorded for pods plant-1 under stress condition. Highest broad-sense heritability estimates (96.54%, 94.97%, and 93.16%) coupled with high genetic advance as percent of the mean (22.32%, 34.97%, and 26.32%) were obtained for the number of pods plant−1, days to maturity, and yield plant−1, respectively, showing that selection of these traits together could lead to yield improvement under stressed conditions. Harvest index showed a significant and positive relationship with biomass aboveground (r=0.86) and the number of pods plant−1 (r=0.86) indicating the possibility of identifying high performing lines of common beans for drought stress environment for further studies on these traits.
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- 2019
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142. Nurses’ perceptions of caring and uncaring nursing encounters in inpatient rehabilitation settings in South Africa: A qualitative descriptive study
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Joan Chebet Cheruiyot and Petra Brysiewicz
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History of Africa ,DT1-3415 ,Nursing ,RT1-120 - Abstract
Background: Nursing encounters are face-to-face meetings and interactions occurring between the nurse and the patient and they can be experienced as being caring or uncaring. Caring nursing encounters are those that promote positive care experiences to the patient leading to satisfaction with care, and an improvement in their well-being. Uncaring nursing encounters promote negative care experiences, leading to patients’ dissatisfaction with care and a decrease in patients’ wellness. Purpose: This study describes nurses’ perceptions of caring and uncaring nursing encounters in inpatient rehabilitation settings. Methods: This study utilized an exploratory and descriptive qualitative approach using manifest content analysis. Participants were purposively sampled and a semi-structured interview guide used to collect data through individual interviews. Data redundancy was reached after interviewing 21 participants. This is part of a larger case study aimed at developing guidelines to facilitate caring encounters in inpatient rehabilitation settings. Results: Caring nursing encounters were “keeping their hope alive” and “going the extra mile,” while uncaring nursing encounters were “frustration with patients,” “being inadequate,” and “ignoring the patient.” Conclusion: Caring nursing encounters promoted positive patient care experiences, easing their rehabilitation journey, while uncaring nursing encounters elicited strong negative emotions, giving patients feelings of being denied compassionate care. Recommendation: Nurses must constantly encourage the rehabilitation patient to stay positive in the rehabilitation journey and empower them to self-manage their conditions. Nurses must strive to strike a balance in caring by building trust with rehabilitation patients and encourage them to air their grievances regarding uncaring nursing encounters as they happen. Keywords: Caring encounters, Uncaring encounters, Nurses, Rehabilitation nursing, Qualitative research
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- 2019
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143. Remembering Prof. Hassan Saidi: The Pillar for Young Anatomists and Trainee Doctors
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Brian Ngure Kariuki, Beda Olabu,, Isaac Cheruiyot, and Moses Obimbo, Julius Ogeng’o
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anatomy training ,intercalated degree ,mentor ,Surgery ,RD1-811 - Published
- 2019
144. A high-intensity cluster of Schistosoma mansoni infection around Mbita causeway, western Kenya: a confirmatory cross-sectional survey
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Chadeka, Evans Asena, Nagi, Sachiyo, Cheruiyot, Ngetich B., Bahati, Felix, Sunahara, Toshihiko, Njenga, Sammy M., and Hamano, Shinjiro
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- 2019
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145. Tracking Antimicrobial Resistance Determinants in Diarrheal Pathogens: A Cross-Institutional Pilot Study
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Chris R. Taitt, Tomasz A. Leski, Michael G. Prouty, Gavin W. Ford, Vireak Heang, Brent L. House, Samuel Y. Levin, Jennifer A. Curry, Adel Mansour, Hanan El Mohammady, Momtaz Wasfy, Drake Hamilton Tilley, Michael J. Gregory, Matthew R. Kasper, James Regeimbal, Paul Rios, Guillermo Pimentel, Brook A. Danboise, Christine E. Hulseberg, Elizabeth A. Odundo, Abigael N. Ombogo, Erick K. Cheruiyot, Cliff O. Philip, and Gary J. Vora
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diarrheal pathogen ,antimicrobial resistance ,Campylobacter ,Shigella ,Escherichia coli ,Salmonella ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Infectious diarrhea affects over four billion individuals annually and causes over a million deaths each year. Though not typically prescribed for treatment of uncomplicated diarrheal disease, antimicrobials serve as a critical part of the armamentarium used to treat severe or persistent cases. Due to widespread over- and misuse of antimicrobials, there has been an alarming increase in global resistance, for which a standardized methodology for geographic surveillance would be highly beneficial. To demonstrate that a standardized methodology could be used to provide molecular surveillance of antimicrobial resistance (AMR) genes, we initiated a pilot study to test 130 diarrheal pathogens (Campylobacter spp., Escherichia coli, Salmonella, and Shigella spp.) from the USA, Peru, Egypt, Cambodia, and Kenya for the presence/absence of over 200 AMR determinants. We detected a total of 55 different determinants conferring resistance to ten different categories of antimicrobials: genes detected in ≥ 25 samples included blaTEM, tet(A), tet(B), mac(A), mac(B), aadA1/A2, strA, strB, sul1, sul2, qacEΔ1, cmr, and dfrA1. The number of determinants per strain ranged from none (several Campylobacter spp. strains) to sixteen, with isolates from Egypt harboring a wider variety and greater number of genes per isolate than other sites. Two samples harbored carbapenemase genes, blaOXA-48 or blaNDM. Genes conferring resistance to azithromycin (ere(A), mph(A)/mph(K), erm(B)), a first-line therapeutic for severe diarrhea, were detected in over 10% of all Enterobacteriaceae tested: these included >25% of the Enterobacteriaceae from Egypt and Kenya. Forty-six percent of the Egyptian Enterobacteriaceae harbored genes encoding CTX-M-1 or CTX-M-9 families of extended-spectrum β-lactamases. Overall, the data provide cross-comparable resistome information to establish regional trends in support of international surveillance activities and potentially guide geospatially informed medical care.
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- 2020
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146. Farmers’ Perception and Evaluation of Brachiaria Grass (Brachiaria spp.) Genotypes for Smallholder Cereal-Livestock Production in East Africa
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Duncan Cheruiyot, Charles A.O. Midega, Jimmy O. Pittchar, John A. Pickett, and Zeyaur R. Khan
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brachiaria ,cereal-livestock production ,perception ,push-pull technology ,smallholder farmers ,Agriculture (General) ,S1-972 - Abstract
Brachiaria (Urochloa) is a genus, common name brachiaria, of forage grasses that is increasingly transforming integrated crop-livestock production systems in East Africa. A study was undertaken to (i) assess smallholder farmers’ perception on benefits of brachiaria in cereal-livestock production, (ii) identify brachiaria production constraints, and (iii) identify farmer preferred brachiaria genotypes. A multi-stage sampling technique was adopted for sample selection. Data were collected through semi-structured individual questionnaire and focus group discussions (FGDs). The study areas included Bondo, Siaya, Homabay and Mbita sub-counties in Western Kenya and the Lake zone of Tanzania. A total of 223 farmers participated in individual response questionnaires while 80 farmers participated in the FGDs. The respondents considered brachiaria mainly important in management of cereal pests (70.4% of respondents) and as an important fodder (60.8%). The major production constraint perceived by both male and female respondents is attacks by arthropods pests (49.2% and 63%, respectively). Spider smites had been observed on own farms by 50.8% of men and 63.1% of women, while sorghum shoot flies had been observed by 58.1% of men and 67.9% of women. These pests were rated as a moderate to severe problem. Xaraes was the most preferred genotype, followed by Mulato II and Piata. These genotypes are important in developing new crop pest management strategies, such as push-pull, and for relatively rapid improvements in crop management and yield increases, particularly in developing countries.
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- 2020
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147. Need for an Integrated Deprived Area 'Slum' Mapping System (IDEAMAPS) in Low- and Middle-Income Countries (LMICs)
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Dana R. Thomson, Monika Kuffer, Gianluca Boo, Beatrice Hati, Tais Grippa, Helen Elsey, Catherine Linard, Ron Mahabir, Catherine Kyobutungi, Joshua Maviti, Dennis Mwaniki, Robert Ndugwa, Jack Makau, Richard Sliuzas, Salome Cheruiyot, Kilion Nyambuga, Nicholus Mboga, Nicera Wanjiru Kimani, Joao Porto de Albuquerque, and Caroline Kabaria
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urban ,poverty ,SDG ,slum ,deprivation, spatial model ,Social Sciences - Abstract
Ninety percent of the people added to the planet over the next 30 years will live in African and Asian cities, and a large portion of these populations will reside in deprived neighborhoods defined by slum conditions, informal settlement, or inadequate housing. The four current approaches to neighborhood deprivation mapping are largely siloed, and each fall short of producing accurate, timely, and comparable maps that reflect local contexts. The first approach, classifying “slum households” in census and survey data, reflects household-level rather than neighborhood-level deprivation. The second approach, field-based mapping, can produce the most accurate and context-relevant maps for a given neighborhood, however it requires substantial resources, preventing up-scaling. The third and fourth approaches, human (visual) interpretation and machine classification of air or spaceborne imagery, both overemphasize informal settlements, and fail to represent key social characteristics of deprived areas such as lack of tenure, exposure to pollution, and lack of public services. We summarize common areas of understanding, and present a set of requirements and a framework to produce routine, accurate maps of deprived urban areas that can be used by local-to-international stakeholders for advocacy, planning, and decision-making across Low- and Middle-Income Countries (LMICs). We suggest that machine learning models be extended to incorporate social area-level covariates and regular contributions of up-to-date and context-relevant field-based classification of deprived urban areas.
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- 2020
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148. Optimizing Food Waste Composting Parameters and Evaluating Heat Generation
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Chin Ko Yeh, Chitsan Lin, Hsueh Chen Shen, Nicholas Kiprotich Cheruiyot, Mary Ellen Camarillo, and Chung Lung Wang
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facultative aerobic treatment ,moisture content ,microbial inoculant ,bioenergy recovery ,waste-to-resource ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The optimal initial moisture content and seeding proportion with mature compost (microbial inoculant) during food waste composting were investigated. This involved six different moisture contents (42%, 55%, 61%, 66%, 70%, and 78%) and four different mature compost seeding amounts (0%, 10%, 20%, and 30% w/w). The temperature variation of these different setups during the first four days of composting was used to determine the most effective one. Our findings showed that the initial moisture contents of 55–70% and the 20% w/w of mature compost were optimal for effective food waste composting. A 400 kg compost pile with the optimal compost mixture ratio was then used to study the evolution and spatial distribution of the temperature during a 30-day composting period. Finally, the heat produced during the 30-day composting process was estimated to be 2.99 MJ/kg. Further investigations, including a cost–benefit analysis from a pilot facility, would be required to comprehensively conclude the feasibility of food waste composting as a bioenergy source.
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- 2020
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149. Use of High Density Single Nucleotide Polymorphism (SNP) Arrays to Assess Genetic Diversity and Population Structure of Dairy Cattle in Smallholder Dairy Systems: The Case of Girinka Programme in Rwanda
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Mizeck G. G. Chagunda, Fidalis D. N. Mujibi, Theogene Dusingizimana, Olivier Kamana, Evans Cheruiyot, and Okeyo A. Mwai
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genetic diversity ,population structure ,dairy cattle ,smallholder ,SNP arrays ,Genetics ,QH426-470 - Abstract
In most smallholder dairy programmes, farmers are not fully benefitting from the genetic potential of their dairy cows. This is in part due to the mismatch between the available genotypes and the environment, including management, in which the animals perform. With sparse performance and pedigree records in smallholder dairy farms, the true degree of baseline genetic variability and breed composition is not known and hence rendering any genetic improvement initiative difficult to implement. Using the Girinka programme of Rwanda as an exemplar, the current study was aimed at better understanding the genetic diversity and population structure of dairy cattle in the smallholder dairy farm set up. Further, the association between farmer self-reported cow genotypes and genetically determined genotypes was investigated. The average heterozygosity estimates were highest (0.38 ± 0.13) for Rwandan dairy cattle and lowest for Gir and N’Dama (0.18 ± 0.19 and 0.25 ± 0.20, respectively). Systematic characterization of the genetic variation and diversity available may inform the formulation of sustainable improvement strategies such as targeting and matching the genotype of cows to productivity goals and farmer profile and hence reducing the negative impact of genotype by environment interaction.
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- 2018
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150. In vitro antioxidant and antimicrobial activity of Prunus africana (Hook. f.) Kalkman (bark extracts) and Harrisonia abyssinica Oliv. extracts (bark extracts): A comparative study
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Edwin S. Madivoli, Ernest G. Maina, Pius K. Kairigo, Martin K. Murigi, Joel K. Ogilo, Jared O. Nyangau, Paul K. Kimani, and Cheruiyot Kipyegon
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FTIR ,Total phenolic ,total flavonoid ,antioxidant ,antibacterial ,Botany ,QK1-989 ,Pharmacy and materia medica ,RS1-441 - Abstract
Background: Plants are new sources of antibacterial agents, hence the need to determine and evaluate the antibacterial properties, antioxidant activity and gas chromatography – mass spectrometer (GC-MS) profile of medicinal plants. Methodology: In this study, sequential extraction of Prunus africana and Harrisonia abyssinica was used to obtain ethyl acetate and methanol extracts. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), whereas the total phenolic and total flavonoid contents were estimated using Folin-Ciocalteu and aluminium chloride, respectively. Antibacterial properties of the extracts against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coliand Candida albicans were estimated using the disc diffusion method and compared against streptomycin. Results: Screening of crude methanolic extracts revealed the presence of secondary metabolites which was further confirmed by Fourier transform infrared (FT-IR) characterisation that revealed the presence of H-bonded OH functional groups. The extracts revealed that P. africana had a higher total phenolic and total flavonoid contents compared to H. abyssinica. Methanolic extracts of both plants had moderate activity against selected microorganisms and both inhibited DPPH radical scavenging activity. GC-MS analysis of P. africana and H. abyssinica extracts revealed the presence of several phytochemicals that have been reported to have medicinal uses. Total phenolic and flavonoid contents showed positive correlations with the DPPH radical scavenging activity and negative correlations with EC50. Conclusion: Prunus africana and H. abyssinica extracts had moderate antimicrobial properties against the selected microorganisms because of the presence of secondary metabolites.
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- 2018
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