Rangeland Livelihood Strategies under Varying Climate Regimes: Model Insights from Southern Kenya

Rangelands throughout sub-Saharan Africa are currently undergoing two major pressures: climate change (through altered rainfall and seasonality patterns) and habitat fragmentation (brought by land use change driven by land demand for agriculture and conservation). Here we explore these dimensions, investigating the impact of land use change decisions, by pastoralists in southern Kenya rangelands, on human well-being and animal densities using an agent-based model. The constructed agent-based model uses input biomass data simulated by the Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS) dynamic vegetation model and parameterized with data from literature. Scenarios of land use change under different rainfall years, land tenure types and levels of wildlife conservation support were simulated. Reflecting reality, our results show livestock grazing as the predominant land use that changes with precipitation and land tenure leading to varying livelihood strategies. For example, agriculture is the most common livelihood in wet years and conservation levels increase with increasing support of wildlife conservation initiatives. Our model demonstrates the complex and multiple interactions between pastoralists, land management and the environment. We highlight the importance of understanding the conditions driving the sustainability of semi-arid rangelands and the communities they support, and the role of external actors, such as wildlife conservation investors, in East Africa

Co-occurrence between Alcohol Use and Tuberculosis among Patients in Othaya Level 4 Hospital

Although the government and partners have made significant investments in Tuberculosis (TB) prevention and treatment over the last 20 years, tuberculosis remains the fourth leading cause of death in Kenya. Alcohol intake, particularly heavy consumption, is a significant risk factor for tuberculosis. This study sought to establish the association between alcohol abuse and tuberculosis prevalence in Othaya Level 4 hospital, Kenya. The study was anchored on the ecological systems theory and employed descriptive survey design. The target population of this study were patient attending TB Clinic in Othaya Level 4 hospital. The study sample targeted 47 Tuberculosis patients enrolled in Othaya Level 4 hospital clinic, one clinical officer, a nurse, a social worker and a public health officer. Both quantitative and qualitative techniques were used in data collection. Data was collected using structured questionnaires, focus group discussions and key informant interviews. Findings from this study were presented in form of tables and graphs and narration for quantitative and qualitative data respectively. The study found that that 40% of TB patients had low-risk consumption while an equal number had hazardous or harmful alcohol consumption respectively. The results showed that 20% had a score of over 15 meaning that they were alcohol dependent. Age (p=0.0013) and marital status (p=0.013) were statistically significant for alcohol abuse whereby young respondents (<40 years) were 1.484 times likely to have alcohol abuse. Married respondents were 7.2 times likely to have alcohol abuse. Participants identified lack of adequate knowledge on the part of healthcare givers, ignorance and illiteracy on the part of the patients as well as culture as the barriers to overcome alcohol dependence. FGD participants recommended health education and support in overcoming alcohol abuse in treatment of TB

Resource allocation in non-orthogonal multiple access technologies for 5G networks and beyond.

Doctoral Degree. University of KwaZulu-Natal, Durban.The increasing demand of mobile and device connectivity poses challenging requirements for 5G wireless communications, such as high energy- and spectral-efficiency and low latency. This necessitates a shift from orthogonal multiple access (OMA) to Non-Orthogonal Multiple Access (NOMA) techniques, namely, power-domain NOMA (PD-NOMA) and code-domain NOMA (CD-NOMA). The basic idea behind NOMA schemes is to co-multiplex different users on the same resource elements (time slot, OFDMA sub-carrier, or spreading code) via power domain (PD) or code domain (CD) at the transmitter while permitting controllable interference, and their successful multi-user detection (MUD) at the receiver albeit, increased computational complexity. In this work, an analysis on the performance of the existing NOMA schemes is carried out. Furthermore, we investigate the feasibility of a proposed uplink hybrid-NOMA scheme namely power domain sparse code multiple access (PD-SCMA) that integrates PD-NOMA and CD-NOMA based sparse code multiple access (SCMA) on heterogeneous networks (HetNets). Such hybrid schemes come with resource allocation (RA) challenges namely; codebook allocation, user pairing and power allocation. Therefore, hybrid RA schemes namely: Successive Codebook Ordering Assignment (SCOA) for codebook assignment (CA), opportunistic macro cell user equipment (MUE)- small cell user equipment (SUE) pairing (OMSP) for user pairing (UP), and a QoS-aware power allocation (QAPA) for power allocation (PA) are developed for an energy efficient (EE) system. The performance of the RA schemes is analyzed alongside an analytical RA optimization algorithm. Through numerical results, the proposed schemes show significant improvements in the EE of the small cells in comparison with the prevalent schemes. Additionally, there is significant sum rate performance improvement over the conventional SCMA and PD-NOMA. Secondly, we investigate the multiplexing capacity of the hybrid PD-SCMA scheme in HetNets. Particularly, we investigate and derive closed-form solutions for codebook capacity, MUE multiplexing and power capacity bounds. The system’s performance results into low outage when the system’s point of operation is within the multiplexing bounds. To alleviate the RA challenges of such a system at the transmitter, dual parameter ranking (DPR) and alternate search method (ASM) based RA schemes are proposed. The results show significant capacity gain with DPR-RA in comparison with conventional RA schemes. Lastly, we investigate the feasibility of integrating the hybrid PD-SCMA with multiple-input multipleoutput (MIMO) technique namely, M-PD-SCMA. The attention to M-PD-SCMA resides in the need of lower number of antennas while preserving the system capacity thanks to the overload in PDSCMA. To enhance spectral efficiency and error performance we propose spatial multiplexing at the transmitter and a low complex joint MUD scheme based on successive interference cancellation (SIC) and expectation propagation algorithm (EPA) at the receiver are proposed. Numerical results exhibit performance benchmark with PD-SCMA schemes and the proposed receiver achieves guaranteed bit error rate (BER) performance with a bounded increase in the number of transmit and receive antennas. Thus, the feasibility of an M-PD-SCMA system is validated

Integrating Human Factors into Chemical Process Quantitative Risk Analysis

Bei der Durchführung einer quantitativen Risikoanalyse (chemical process quantitative risk analysis - CPQRA) verfahrenstechnischer Anlagen kann der Human Factor (HF) durch den Ansatz der menschlichen Zuverlässigkeitstechnik (human reliability analysis - HRA) berücksichtigt werden. Eine der wichtigsten Aufgaben dabei ist die Bestimmung der Wahrscheinlichkeit eines menschlichen Fehlers (human error probability – HEP), um das bestehende Risiko korrekt abschätzen zu können. Das größte Problem dabei besteht jedoch in den starken Unsicherheiten, mit denen diese HEPs belegt sind, wodurch nicht die realen Bedingungen der betrachteten Anlage bzw. des betrachteten Systems zu Grunde gelegt werden. Es ist jedoch für die Berücksichtigung des HF bei der Durchführung einer QRA von grundlegender Bedeutung, dass mögliche menschliche Ursachen von Ereignissen und Unfällen umfassend identifiziert und quantifiziert werden. Somit wird eine systematische Methode benötigt, mit deren Hilfe einzelnen HF- Faktoren, welche zu einem Unfall führen können, analysiert werden können. Dafür wurde zunächst eine qualitative Methode, zur Bewertung des Human Factors einer verfahrenstechnischen Anlage entwickelt. Diese stellt eine Grundlage für die Integration des HF in die Risikoanalyse dar. Es wurde eine umfangreiche Kategorisierung aller Faktoren, welche die Leistung des Bedieners beeinflussen, erarbeitet, um die realen Bedingungen, welche zu Fehlern führen können zu identifizieren. Diese Faktoren werden auch dazu verwendet, die bestehenden HEPs und die von Experten abgeschätzten Werte abzugleichen. Die Arbeit läßt sich in folgende Schritte unterteilen: i) Entwicklung einer qualitativen HF- Bewertungs- Methode. Diese beinhaltet die gesamte Bandbreite des HF und kann angewendet werden, um die HF- Qualität einer bestehenden Anlage abzuschätzen. ii) Entwicklung einer Kategorisierung um „human error“ Ereignisse zu identifizieren und die organisatorischen Faktoren hinter diesen Ereignissen zu analysieren. iii) Quantifizierung der einzelnen HF- Faktoren für die quantitative Risikoanalyse. Dabei wurde die Gewichtung der Faktoren durch eine ausführliche Expertenbefragung vorgenommen.Inclusion of human factors in the chemical process quantitative risk analysis (CPQRA) is done by use of human reliability analysis (HRA) techniques. Therefore, to avoid under or overestimation of the actual risk, human error probability (HEP) estimation must be reasonably accurate. This work was founded on the premise that most HEPs used in CPQRA are plagued with uncertainty and therefore do not represent the actual conditions of the system or plant being analysed. However, it is critical that the potential human causes for major accidents be exhaustively identified and quantified for a complete QRA. There is need to introduce a systematic method to analyse the underlying human factors, which cause errors that lead to accidents. To achieve this, first a qualitative method to assess human factors was developed. It formed basis of introducing the aspects of human factors into quantitative risk analysis. An extended framework to capture human and organisation factors that influence the operator performance in order to identify the actual error producing conditions that lead to basic events has also been described in this work. These factors are used to adjust the existing HEPs or the ones that are estimated by experts. The work was accomplished in the following steps: i) Development of a qualitative human factors assessment tool. The tool covers the whole human factors spectrum and could be used for auditing HF maturity level for a given plant. ii) Development of a framework to identify human error events and to analyse human and organisational factors behind these error events. This information is critical in establishing the influence that impacts indirectly yet powerfully the probability of an accident. iii) Quantification of the human and organisational factors for quantitative risk analysis (QRA). An important part is weighting of HF that was done by use of a questionnaire sent to industrial representatives

Expressed centromere specific histone 3 (CENH3) variants in cultivated triploid and wild diploid bananas (Musa spp.)

Open Access JournalCentromeres are specified by a centromere specific histone 3 (CENH3) protein, which exists in a complex environment, interacting with conserved proteins and rapidly evolving satellite DNA sequences. The interactions may become more challenging if multiple CENH3 versions are introduced into the zygote as this can affect post-zygotic mitosis and ultimately sexual reproduction. Here, we characterize CENH3 variant transcripts expressed in cultivated triploid and wild diploid progenitor bananas. We describe both splice- and allelic-[Single Nucleotide Polymorphisms (SNP)] variants and their effects on the predicted secondary structures of protein. Expressed CENH3 transcripts from six banana genotypes were characterized and clustered into three groups (MusaCENH-1A, MusaCENH-1B, and MusaCENH-2) based on similarity. The CENH3 groups differed with SNPs as well as presence of indels resulting from retained and/or skipped exons. The CENH3 transcripts from different banana genotypes were spliced in either 7/6, 5/4 or 6/5 exons/introns. The 7/6 and the 5/4 exon/intron structures were found in both diploids and triploids, however, 7/6 was most predominant. The 6/5 exon/introns structure was a result of failure of the 7/6 to splice correctly. The various transcripts obtained were predicted to encode highly variable N-terminal tails and a relatively conserved C-terminal histone fold domain (HFD). The SNPs were predicted in some cases to affect the secondary structure of protein by lengthening or shorting the affected domains. Sequencing of banana CENH3 transcripts predicts SNP variations that affect amino acid sequences and alternatively spliced transcripts. Most of these changes affect the N-terminal tail of CENH3

Prevalence of Group a Rotavirus before and after Vaccine Introduction in Mukuru Informal Settlement in Kenya

Background: Rotavirus vaccines have been shown to be a lifesaving and cost-effective public health intervention in Africa and have resulted in reduced rotavirus mortality. In Kenya, rotavirus diarrhea causes 19% of hospitalizations and 16% of clinic visits among children <5 years of age and causes 4471 deaths and 8,781 hospitalizations per year. Nationally, rotavirus disease costs the health care system $10.8 million annually. It is estimated that routine vaccination with a 2-dose rotavirus vaccination series would avert approximately 2,467 deaths (55%), 5,724 hospitalizations (65%), 852, 589 clinic visits (59%) and would save 58 disability-adjusted life-years (DALYs) per 1000 children annually. In July 2014, Kenya introduced rotavirus vaccine into its routine expanded programme  immunisation, with two doses given at 6 and 10ths week of age.WHO recommend having  surveillance studies before and after vaccine as baseline data and monitoring the possible effect after vaccine introductions. The aim of this study was to determine the prevalence of rotavirus in pre- and post-vaccine stool samples collected from children under five years, attending two selected clinics in Mukuru informal settlement in Nairobi, Kenya. Methods: Archived samples collected during a Salmonella surveillance study (SSC No. 2074) conducted between July 2013 and July 2015 were used for this study. A total of 270 samples (150 pre-vaccine and 120 post-vaccine) were tested for rotavirus using ELISA Prospect kit (Oxoid Ltd UK) and data analyzed using SPSS version 20. Results: Rotavirus prevalence was 10% (15/150) and 5% (6/120) in pre-vaccine and post-vaccine samples respectively. There was significant difference in prevalence pre and post vaccine samples for children less than 12 months (P=0.014), 13-24 months (P=0.002) and over 49 months (P=0.01). However, there was no difference in prevalence for age categories 25-36 and 37- 48 months. Conclusion: This study showed a reduction in prevalence of Group A rotavirus in Mukuru selected clinics one year after vaccine introduction into National immunization program in Kenya. Rotavirus prevalence differed significantly for cases less than 12 months, 13-24 months and over 49 months pre and post vaccine introduction. However, there was no difference in prevalence for age category 25-36 and 37- 48 months thus the vaccine proved to have a significant protection in the most vulnerable group of children. Keywords: Rotavirus, Kenya, vaccine, pre-vaccine, post-vaccine, prevalence, Kenya

Mono- and dimeric complexes of an asymmetric heterotopic P,CNHC,pyr ligand

An asymmetric heterotopic ligand (S-NMeCP) containing a central bicyclic, expanded-ring NHC with one pyridyl and one phosphine exo-substituent has been synthesised and its coordination chemistry with selected late transition metals investigated. The amidinium precursor [S-NMeCHP]PF6 shows variable coordination modes with Ag(I), Cu(I) and Au(I) depending on the L:M ratio. The reaction of two mols of [S-NMeCHP]PF6 with [Cu(MeCN)4]BF4, AgBF4 or Au(THT)Cl gives the bis-ligand complexes [Cu(κ-P-NMeCHP)2(CH3CN)2]BF4·(PF6)2, 1, and [M(κ-P-NMeCHP)2]X·(PF6)2 (3: M = Ag, X = BF4; 6: M = Au, X = Cl) respectively. The 1:1 reaction of [S-NMeCHP]PF6 with AgOTf gave the head-to-tail dimer H,T-[Ag2(μ-N,P-NMeCHP)2(μ-OTf)2](PF6)2, 2, whereas the analogous reaction with Au(THT)Cl gave monomeric [Au(κ-P-NMeCHP)Cl]PF6, 5. Complex 2 was converted to H,T-[Ag2(μ-C,P-NMeCP)2](PF6)2, 4, upon addition of base, while 6 gave [Au(κ-C-NMeCP)2]Cl, 8, when treated likewise. Reaction of [S-NMeCHP]PF6 with Ni(1,5-COD)2 gave the oxidative addition/insertion product [Ni(κ3-N,C,P-NMeCP)(η3-C8H13)]PF6, 9, which converted to [Ni(κ3-N,C,P-NMeCP)Cl]PF6, 10, upon exposure of a CHCl3 solution to air. Complex 10 showed conformational isomerism that was also present in [Rh(κ3-N,C,P-NMeCP)(CO)]PF6, 14, prepared from the precursor complex [Rh(κ-P-NMeCHP)(acac)(CO)]PF6, 13, upon heating in C6H5Cl. [Pt(κ3-N,C,P-NMeCP)(Cl)]PF6, 12, derived from trans-[Pt(κ-P-NMeCHP)2(Cl)2](PF6)2, 11, was isolated as a single conformer

Is Disruptive Employee Behavior In Export Processing Zones (EPZs) Influenced By Their Employment In Firms Situated In Public Or Private Zones?

The Kenyan government’s Export processing zone (EPZ) policy has conceded large parts of existing labour laws to EPZ investors. This article sets out to establish whether there is a difference in the working conditions employers in the public and private zones expose their workers to and from which zone possible disruptive employee behaviours emanate from. A random sample of 376 employees was selected from EPZ garment firms located in both private and public zones. Statistical procedures were applied to determine possible differences. The findings indicate that employees from companies in the private zones were exposed to better working conditions than those employed in companies located in the public zone, which explains why disruptive employee behaviour originates from the public zone. It is recommended that working conditions of companies in the pubic zone should be improved. Opsomming Die regering se uitvoerprosesseringsbeleid (EPZ) het toegewings in terme van bestaande arbeidswetgewing aan EPZ investeerders gedoen. Hierdie artikel het ten doel om vas te stel of daar ’n verskil bestaan in die werktoestande waaraan werkgewers in die openbare en private sones hulle werknemers blootstel en van watter sone moontlike ontwrigtende gedrag hul oorsprong het. ’n Ewekansige steekproef van 376 werknemers is uit EPZ kledingfirmas in beide die private en openbare sones getrek. Statistiese prosedures is gebruik om moontlike verskille te bepaal. Die bevindinge dui daarop dat werknemers van maatskappy uit private sones aan beter werkstoestande blootgestel is teenoor dié wat uit die publieke sone afkomstige is, wat ook verklaar waarom ontwrigtende gedrag uit die openbare sone onstaan. Dit word aanbeveel dat werktoestande van maatskappye in die openbare sone verbeter word

Combined DNA extraction and antibody elution from filter papers for the assessment of malaria transmission intensity in epidemiological studies.

BACKGROUND: Informing and evaluating malaria control efforts relies on knowledge of local transmission dynamics. Serological and molecular tools have demonstrated great sensitivity to quantify transmission intensity in low endemic settings where the sensitivity of traditional methods is limited. Filter paper blood spots are commonly used a source of both DNA and antibodies. To enhance the operational practicability of malaria surveys, a method is presented for combined DNA extraction and antibody elution. METHODS: Filter paper blood spots were collected as part of a large cross-sectional survey in the Kenyan highlands. DNA was extracted using a saponin/chelex method. The eluate of the first wash during the DNA extraction process was used for antibody detection and compared with previously validated antibody elution procedures. Antibody elution efficiency was assessed by total IgG ELISA for malaria antigens apical membrane antigen-1 (AMA-1) and merozoite-surface protein-1 (MSP-142). The sensitivity of nested 18S rRNA and cytochrome b PCR assays and the impact of doubling filter paper material for PCR sensitivity were determined. The distribution of cell material and antibodies throughout filter paper blood spots were examined using luminescent and fluorescent reporter assays. RESULTS: Antibody levels measured after the combined antibody/DNA extraction technique were strongly correlated to those measured after standard antibody elution (p < 0.0001). Antibody levels for both AMA-1 and MSP-142 were generally slightly lower (11.3-21.4%) but age-seroprevalence patterns were indistinguishable. The proportion of parasite positive samples ranged from 12.9% to 19.2% in the different PCR assays. Despite strong agreement between outcomes of different PCR assays, none of the assays detected all parasite-positive individuals. For all assays doubling filter paper material for DNA extraction increased sensitivity. The concentration of cell and antibody material was not homogenously distributed throughout blood spots. CONCLUSION: Combined DNA extraction and antibody elution is an operationally attractive approach for high throughput assessment of cumulative malaria exposure and current infection prevalence in endemic settings. Estimates of antibody prevalence are unaffected by the combined extraction and elution procedure. The choice of target gene and the amount and source of filter paper material for DNA extraction can have a marked impact on PCR sensitivity

Large-scale implementation of disease control programmes: a cost-effectiveness analysis of long-lasting insecticide-treated bed net distribution channels in a malaria-endemic area of western Kenya-a study protocol.

Introduction Historically, Kenya has used various distribution models for long-lasting insecticide-treated bed nets (LLINs) with variable results in population coverage. The models presently vary widely in scale, target population and strategy. There is limited information to determine the best combination of distribution models, which will lead to sustained high coverage and are operationally efficient and cost-effective. Standardised cost information is needed in combination with programme effectiveness estimates to judge the efficiency of LLIN distribution models and options for improvement in implementing malaria control programmes. The study aims to address the information gap, estimating distribution cost and the effectiveness of different LLIN distribution models, and comparing them in an economic evaluation. Methods and analysis Evaluation of cost and coverage will be determined for 5 different distribution models in Busia County, an area of perennial malaria transmission in western Kenya. Cost data will be collected retrospectively from health facilities, the Ministry of Health, donors and distributors. Programme-effectiveness data, defined as the number of people with access to an LLIN per 1000 population, will be collected through triangulation of data from a nationally representative, cross-sectional malaria survey, a cross-sectional survey administered to a subsample of beneficiaries in Busia County and LLIN distributors’ records. Descriptive statistics and regression analysis will be used for the evaluation. A cost-effectiveness analysis will be performed from a health-systems perspective, and cost-effectiveness ratios will be calculated using bootstrapping techniques. Ethics and dissemination The study has been evaluated and approved by Kenya Medical Research Institute, Scientific and Ethical Review Unit (SERU number 2997). All participants will provide written informed consent. The findings of this economic evaluation will be disseminated through peer-reviewed publications