36 research outputs found
Coping with Resource Management Challenges in Mumias Sub-County, Kakamega County, Kenya
The gist of the study was to examine the main coping strategies used to manage resources in public secondary schools in Mumias Sub- County, Kakamega County, Kenya. The study was premised on Hunts (2007) theory on project management. A descriptive survey design was adopted. A combination of Purposive and simple random sampling techniques were used to draw 25 head teachers, 200 teachers and 25 chairpersons of Parents Teachers Association (PTAs), yielding a total sample of 250 respondents. Interview schedules and questionnaires were used to collect data from chairpersons and head teachers/teachers, respectively. The study established that the various resource management challenges were: inadequate funding by the Government through the Ministry of Education, overstretched physical facilities as well as inefficient utilization of the available physical and human resources in schools. In addition, most schools had devised coping strategies to manage the constraints. It was recommended that school managers should involve teachers and learners in decision making process regarding effective management strategies that enhance school quality outcomes in Mumias Sub-County, Kakamega County , Kenya.[172 words]. Keywords: Management strategies, Public Secondary Schools, Mumias Sub-county, Resources, Kenya
The impact of conventional and organic farming on soil biodiversity conservation: a case study on termites in the long-term farming systems comparison trials in Kenya
A long-term experiment at two trial sites in Kenya has been on-going since 2007 to assess the effect of organic and conventional farming systems on productivity, profitability and sustainability. During these trials the presence of significant numbers of termites (Isoptera) was observed. Termites are major soil macrofauna and within literature they are either depict as ‘pests’ or as important indicator for environmental sustainability. The extent by which termites may be managed to avoid crop damage, but improve sustainability of farming systems is worthwhile to understand. Therefore, a study on termites was added to the long-term experiments in Kenya. The objectives of the study were to quantify the effect of organic (Org) and conventional (Conv) farming systems at two input levels (low and high) on the abundance, incidence, diversity and foraging activities of termites.
The results showed higher termite abundance, incidence, activity and diversity in Org-High compared to Conv-High, Conv-Low and Org-Low. However, the termite presence in each system was also dependent on soil depth, trial site and cropping season. During the experiment, nine different termite genera were identified, that belong to three subfamilies: (i) Macrotermitinae (genera: Allodontotermes, Ancistrotermes, Macrotermes, Microtermes, Odontotermes and Pseudocanthotermes), (ii) Termitinae (Amitermes and Cubitermes) and (iii) Nasutitiermitinae (Trinervitermes).
We hypothesize that the presence of termites within the different farming systems might be influenced by the types of input applied, the soil moisture content and the occurrence of natural enemies. Our findings further demonstrate that the organic high input system attracts termites, which are an important, and often beneficial, component of soil fauna. This further increases the potential of such systems in enhancing sustainable agricultural production in Kenya
Improvement in water stability and other related functional properties of thin cast kafirin protein films
Improvement in the water stability and other related functional properties of thin (<50 µm) karirin protein films was investigated. Thin conventional kafirin films and kafirin microparticle films were prepared by casting in acetic acid solution. Thin kafirin films cast from microparticles were more stable in water than conventional cast kafirin films. Treatment of kafirin microparticles with heat and transglutaminase resulted in slightly thicker films with reduced tensile strength. In contrast, glutaraldehyde treatment resulted in up to a 43% increase in film tensile strength. The films prepared from microparticles treated with glutaraldehyde treatment were quite stable in ambient temperature water, despite the loss of plasticizer. This was probably due to the formation of convalent crosslinking between free amino groups if the kafirin polypeptides and carbonyl groups of the aldehyde. Thus, such thin glutaraldehyde-treated kafirin microparticle films appear to have good potential for use as biomaterials in aqueous applications.J.O.A. acknowledges a University of Pretoria Postgraduate
Research Support Bursary.http://pubs.acs.org/JAF
Role of γ-kafirin in the formation and organization of kafirin microstructures
The possible importance of the cysteine-rich γ-prolamin in kafirin and zein functionality has been neglected. The role of γ-kafirin in organized microstructures was investigated in microparticles. Residual kafirin (total kafirin minus γ-kafirin) “microparticles” were non-discrete (amorphous mass of material), as viewed by electron microscopy and atomic force microscopy. Adding 15% γ-kafirin to residual kafirin resulted in the formation of a mixture of non-discrete material and nanosize discrete spherical structures. Adding 30% γ-kafirin to the residual kafirin resulted in discrete spherical nanosize particles. Fourier transform infrared spectroscopy indicated that γ-kafirin had a mixture of random-coil and β-sheet conformations, in contrast to total kafirin, which is mainly α-helical conformation. γ-Kafirin also had a very high glass transition temperature (Tg) (≈270 °C). The conformation and high Tg of γ-kafirin probably confer structural stability to kafirin microstructures. Because of its ability to form disulfide cross-links, γ-kafirin appears to be essential to form and stabilize organized microstructures.Joseph Anyango is grateful for the provision of a University of Pretoria Postdoctoral Fellowship.http://pubs.acs.org/journal/jafcauhb201
Impact of cowpea adition on the Protein Digestibility Corrected Amino Acid Score and other protein quality parameters of traditional African foods made from non-tannin and tannin sorghum
Protein malnutrition is a problem in Africa where sorghum is a staple foodstuff. Improvement in the protein
quality of traditional African sorghum (Sorghum bicolor L. Moench) foods through the addition of
cowpea (Vigna unguiculata L. Walp), an indigenous African legume, was investigated. Two sorghum cultivars,
a red, tannin-type (NS 5511) and a white tan-plant, non-tannin type (Orbit) were complemented
with cowpea (70:30 ratio). Ugali (thick porridge), uji (fermented thin porridge) and injera (fermented
flatbread) were prepared. The protein lysine scores of cowpea-complemented foods were about double
the levels of sorghum-only foods. The in vitro protein digestibility of the foods increased by 13–62%.
The increase in lysine and protein digestibility improvement resulted in three- and two-fold improvement
in the Protein Digestibility Corrected Amino Acid Score (PDCAAS) of NS 5511, and Orbit foods,
respectively. Addition of cowpea to tannin, as well as non-tannin sorghum is a viable option for improving
the protein quality of a wide range of traditional African foods.http://www.elsevier.com/locate/foodchemnf201
Evaluation of the functional quality of cowpea-fortified traditional African sorghum foods using instrumental and descriptive sensory analysis
Despite nutritional advantages, the functional quality of cereal foods tends to decline when fortified with
legumes. Traditional African cowpea-fortified sorghum foods were evaluated using instrumental and
descriptive sensory analyses. Two sorghum cultivars, NS 5511 (tannin-type) and Orbit (non-tannin-type)
were fortified with cowpea (70:30 ratio). Fortification reduced uji (fermented thin porridge) pasting peak
viscosity and cool paste viscosity by up to 23% and 12%, respectively, probably as a result of starch content
being reduced. NS 5511 injera (fermented thin flatbread) stiffness increased by up to 25%, probably due to
a reduction in tannin content. Orbit injera stiffness reduced by up to 22% probably because increased
protein content reduced starch retrogradation. Fortification increased the firmness of Orbit ugali
(unfermented stiff porridge) by 45% and 17% as assessed by TA-XT2 Texture Analyser and the descriptive
sensory panel, respectively. There was a 20% decrease in instrumental firmness of NS 5511 ugali as
a result of fortification, which was not detected by the sensory panel. Fortification had generally no effect
on the stickiness of ugali. Fortified ugali had a characteristic cowpea flavour. Principal component
analysis (PCA) of ugali sensory attributes indicated a 30% variation due to the presence of cowpea. Most
of the variation (47%) was attributed to sorghum cultivar. Sensory panel analysis concerning ugali
firmness and stickiness correlated positively with the instrumental texture analysis. Fortification with
cowpea affects texture and taste of traditional African sorghum foods, the extent to which largely
depends on the sorghum cultivar concerned. Instrumental texture analysis relates well with human
perception of sorghum food texture and can rapidly predict the effects of fortification with legumes on
such foods.The African Biofortified Sorghum (ABS) Projecthttp://www.elsevier.com/locate/lw
Physicochemical modification of kafirin microparticles and their ability to bind bone morphogenetic protein-2 (BMP-2), for application as a biomaterial
Vacuolated spherical kafirin microparticles with a mean diameter of 5 μm can be formed from an acidic solution
with water addition. Three-dimensional scaffolds for hard tissue repair require large structures with a high degree of
interconnected porosity. Cross-linking the formed kafirin microparticles using wet heat or glutaraldehyde treatment resulted in
larger structures (approximately 20 μm), which, while similar in size and external morphology, were apparently formed by further
assisted assembly by two significantly different mechanisms. Heat treatment, which increased the vacuole size, involved kafirin
polymerization by disulfide bonding with the microparticles being formed from round, coalesced nanostructures, as shown by
atomic force microscopy (AFM). Kafirin polymerization of glutaraldehyde-treated microparticles was not by disulfide bonding,
and the nanostructures, as revealed by AFM, were spindle shaped. Both treatments enhanced BMP-2 binding to the
microparticles, probably due to their increased size. Thus, these modified kafirin microparticles have potential as natural,
nonanimal protein bioactive scaffolds.University of Pretoria
Postgraduate Research Support Bursaryhttp://pubs.acs.org/JAF
Comparison of formation of visco-elastic masses and their properties between zeins and kafirins
Zeins of differing sub-class composition much more readily formed visco-elastic masses in water or acetic acid solutions than equivalent kafirin preparations. Visco-elastic masses could be formed from both zein and kafirin preparations by coacervation from glacial acetic acid. Dissolving the prolamins in glacial acetic acid apparently enabled protonation and complete solvation. Stress-relaxation analysis of coacervated zein and kafirin visco-elastic masses showed they were initially soft. With storage, they became much firmer. Zein masses exhibited predominantly viscous flow properties, whereas kafirin masses were more elastic. The γ-sub-class is apparently necessary for the retention of visco-elastic mass softness with kafirin and zein, and for elastic recovery of kafirin. Generally, regardless of water or acetic acid treatment, all the zein preparations had similar FTIR spectra, with greater α-helical conformation, than the kafirin preparations which were also similar to each other. Kafirin visco-elastic masses have a much higher elastic character than zein masses.http://www.elsevier.com/locate/foodchem2019-04-15hj2018Food Scienc
Biocompatibility and biodegradation of protein microparticle and film scaffolds made from kafirin (sorghum prolamin protein) subcutaneously implanted in rodent models
Kafirin, the sorghum prolamin protein, like its maize homologue zein, can be made into
micropatticles and films and potentially used as a biomaterial. Zein has good bio- and cytocompatibility.
Kafirin could be advantageous as it is more hydrophobic, more cross-linked, more
slowly digested by mammalian proteases than zein and is non-allergenic. The safety and
biocompatibility of kafirin implants in two forms was determined in rodent models. One week
post subcutaneous injection of kafirin micropatticles (size S[!m diameter) in mice, chronic
inflammation, abnormal red blood cells and gross fibrin formation were observed. This chronic
inflammatory response was possibly caused by the release of hydrolysis products such as
glutamate during the degradation of the kafirin microparticles. In contrast, films made from
kaftrin microparticles (50 [!ill thickness, folded into I cm3
) implanted in rats showed no
abnormal inflammatory reactions and were only partially degraded by day 28. The slower
degradation of the kafirin films was probably due to their far smaller surface area when
compared to kafirin micropatticles. Thus, kafirin films appear to have potential as a biomaterial.
This study also raises awareness that the form of prolamin based biomaterials, (kafirin and zein)
should be considered when assessing the safety of such materials.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1552-49652016-08-31hb201
PDBe: towards reusable data delivery infrastructure at protein data bank in Europe
© 2017 The Authors. Published by OUP. This is an open access article available under a Creative Commons licence.
The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1093/nar/gkx1070The Protein Data Bank in Europe (PDBe, pdbe.org) is actively engaged in the deposition, annotation, remediation, enrichment and dissemination of macromolecular structure data. This paper describes new developments and improvements at PDBe addressing three challenging areas: data enrichment, data dissemination and functional reusability. New features of the PDBe Web site are discussed, including a context dependent menu providing links to raw experimental data and improved presentation of structures solved by hybrid methods. The paper also summarizes the features of the LiteMol suite, which is a set of services enabling fast and interactive 3D visualization of structures, with associated experimental maps, annotations and quality assessment information. We introduce a library of Web components which can be easily reused to port data and functionality available at PDBe to other services. We also introduce updates to the SIFTS resource which maps PDB data to other bioinformatics resources, and the PDBe REST API.Wellcome Trust [104948]; UK Biotechnology and Biological Sciences Research Council [BB/M011674/1, BB/N019172/1, BB/M020347/1]; European Union [284209]; European Molecular Biology Laboratory (EMBL). Funding for open access charge: EMBL.Published versio