175 research outputs found
Magnetic Spin Susceptibility of quasi-particles in metals using the Landau Fermi Liquid Theory
    38  In this work, the magnetic spin susceptibility of quasi-particles in metals were computed for some metals based on the modified Landau Fermi Liquids Theory using the electron density parameter. The results showed that for each metal, the Landau magnetic spin susceptibility of quasi-particles is higher than the computed magnetic spin susceptibility of quasi-particles and experimental values. This may be due to the fact that the Landau parameter must have been over estimated in its application. The computed magnetic spin susceptibility of quasi-particles is in good agreement with the experimental values of metals available with a remarkable agreement at. The better estimation of the magnetic spin susceptibility of quasi-particles using the modified Landau Fermi Liquid theory were compared with available experimental values. This show that the introduction of the electron density parameter in the Landau Fermi Liquid theory is promising in predicting the contribution of quasi-particles to the bulk properties of metals. The magnetic spin susceptibility of quasi-particles for transition metals is higher than most of the magnetic spin susceptibility of quasi-particles for alkali metals. This suggests that the magnetic spin susceptibility is considerably higher for most transition metals due to the incomplete inner electronic shells as more quasi-particles can be excited which enhances their susceptibility than the alkali metals
Variability in cooking time, iron and zinc content in common bean (Phaseolus Vulgaris L.) genotypes
Prolonged cooking time leads to structural changes at the grain cellular level, resulting in loss of nutrients such as iron (Fe) and zinc (Zn) which are among the main nutrients important in addressing micronutrient malnutrition. The aim of this study was to evaluate the diversity of cooking time, Fe and Zn content in a total of 152 common bean (Phaseolus vulgaris) genotypes from around Eastern Africa, in order to identify short cooking genotypes with high Fe and Zn content. Field trials were conducted at CIAT-Uganda research station over two seasons in 2016. Cooking time was estimated using an automated Mattson cooker at CIAT-Uganda while Fe and Zn content was determined using XRF analysis at Rwanda Agricultural Board (RAB) in Rubona. A wide variability was evident from the test genotypes both for cooking time and mineral concentration. Cooking time exhibited a continuous distribution ranging from 35-100 minutes for the first season and 43–122 minutes for the second season. Seventy-three percent of the test genotypes had Fe levels higher than the low Fe check, CAL 96 (55mg/kg) which is popularly known as ‘Nambale’ and a popular commercial variety in Uganda. A total of 15 genotypes (Amahunja, Awash melka, Bihogo, CAB 2, ECAPAN021, G858, Icaquimbaya, KK20, NABE12C, NABE4, NABE6, ROBA-1, RWR1873, RWV3006) were consistent in short cooking time for the two seasons and had a Fe content above the low Fe check (CAL96 – 55mg/kg). A high correlation (r = 0.71) was observed between Fe and Zn whereas a low correlation between cooking time and Fe (r = -0.04) and Zn (r = 0.04) was observed. Great variability was evident for both traits indicating possible improvement by breeding and thus the possibility of having short cooking common bean genotypes with high Fe and Zn content
Goniotomy for Non-Infectious Uveitic Glaucoma in Children
Secondary glaucoma is still a blinding complication in childhood uveitis, for which most commonly used surgical interventions (trabeculectomy or glaucoma drainage implant) involve multiple re-interventions and/or complications postoperatively. The goniotomy procedure has never been investigated in the current era, in which patients with pediatric uveitis receive biologics as immunosuppressive therapy for a prolonged period, with potential implications for the outcome. The purpose of the study is to evaluate the efficacy and safety of a goniotomy procedure in pediatric non-infectious uveitis in a retrospective, multicenter case series. The primary outcomes were the postoperative intraocular pressure (IOP), number of IOP-lowering medications, and success rate. Postoperative success was defined as 6 ≤ IOP ≤ 21 mmHg, without major complications or re-interventions. Fifteen eyes of ten children were included. Median age of the included patients at goniotomy was 7 years; median follow-up was 59 months. Median (interquartile range) IOP before surgery was 30 (26–34) mmHg with 4 (3–4) IOP-lowering medications. At 1, 2, and 5 years after goniotomy, median IOP was 15, 14, and 15 mmHg with 2 (0–2), 1 (0–2), and 0 (0–2) medications, respectively (p < 0.001 postoperatively versus preoperatively for all timepoints). Success rate was 100%, 93%, and 80% after 1, 2, and 5 years, respectively. There were no significant changes in visual acuity and uveitis activity or its treatment, and there were no major complications. Our results show that the goniotomy is an effective and safe surgery for children with uveitic glaucoma.</p
Development, promotion and dissemination of improved Fusarium wilt resistant pigeon pea lines in drought prone areas of Uganda
Pigeon Pea (Cajanus cajan) remains a relatively untapped food legume crop in Uganda and in many parts of Africa mainly due to lack of promotion and availability of varieties that meet producer and consumers needs. The crop is a rich source of protein, fixes nitrogen in the soil and is tolerant to drought conditions. This makes it an ideal crop for the semi-arid areas of Africa. This project is using a participatory breeding approach to develop and promote consumer/market preferred pigeon pea varieties resistant to Fusarium wilt disease (Fusarium udum) and drought among farmers in northern Uganda. To do this, a collection of landraces and elite materials from Uganda, Malawi and ICRISAT is being screened for farmer desired qualities. Promising lines will be analyzed for performance under Fusarium wilt infection and drought, and thereafter selected lines will be entered into a breeding program. All research activities have been designed as part of two students' M.Sc. thesis research, involving a Ugandan and a Malawian studen
Feasibilty of zein proteins, simple sequence repeats and phenotypic traits for background selection in quality protein maize breeding
Widespread adoption of quality protein maize (QPM), especially among
tropical farming systems has been slow mainly due to the slow process
of generating varieties with acceptable kernel quality and adaptability
to different agroecological contexts. A molecular based foreground
selection system for opaque 2 (o2), the cause of enhanced lysine
content in maize exists. Background selection systems albeit, are
poorly developed in spite of the mapping of putative loci associated
with kernel modification and knowledge on causes of modification. The
aim of this study was to develop background selection systems for o2
introgression into locally adapted genotypes. Experiments were
conducted at Makerere University Agricultural Research Institute,
Kabanyolo (MUARIK), in Uganda on backcross progeny (BC1F1) and BC2F2),
derived from a locally adapted line 136R and a QPM donor CML176. We
tested the use of zein proteins known to influence modification as well
as DNA markers and phenotypic descriptors as tools for background
selection for recurrent parent genome and modifier loci in locally
adapted maize genotypes. Simply inherited traits such as maize streak
virus disease resistance were suitable for background selection. Other
traits include plant and ear heights. The simple sequence repeats
markers mapped to chromosomes 3, 5, 7, respectively and associated with
quantitative trait loci (QTL) conditioning resistance in maize to grey
leaf spot and anthesis to silking interval were suitable for assay of
recurrent parent genome. The 27-kDa g zein protein levels was suitable
for background selection for kernel modification. It should, however,
be used along with other zeins such as the 22 kDa and 19 kDa zein
proteins.L'adoption du ma\uefs de prot\ue9ne de qualit\ue9 (QPM),
sp\ue9cialement parmi les syst\ue8mes culturaux tropicaux a
\ue9t\ue9 lente principalement due au processus lent de
g\ue9n\ue9ration de vari\ue9t\ue9s avec de grains acceptables
de qualit\ue9 et d'adaptabilit\ue9 \ue0 diff\ue9rents contextes
agro\ue9cologiques. Il existe une cause du contenu am\ue9lior\ue9
de la lysine dans le ma\uefs, un syst\ue8me bas\ue9 sur la
s\ue9lection mol\ue9culaire opaque 2 (o2). Malgr\ue9 les
syst\ue8mes de s\ue9lection de fond, ceux-ci sont pauvrement
d\ue9velopp\ue9s en d\ue9pit du "mapping" du loci associ\ue9
avec la modification du grain et la connaissance sur les causes de
modification. L'objet de cette \ue9tude \ue9tait de d\ue9velopper
les syst\ue8mes de s\ue9lection de fond pour l'introgression o2
dans les g\ue9notypes localement adapt\ue9s. Des essais
\ue9taient conduits sur la prog\ue9nie de "backcross" (BC1F1) et
BC2F2), d\ue9riv\ue9s de lign\ue9es adapt\ue9es 136R et un QPM
doneur CML176. Nous avons test\ue9 l'usage des prot\ue9ines
z\ue9ines capables d'influencer de modifications des marqueurs d'ADN
et descripteurs ph\ue9notypiques comme mat\ue9riel de
s\ue9lection de fond pour parent de g\ue9nome recurrent et
modifiant de loci dans les g\ue9notypes de ma\ubfs localement
adapt\ue9s. Des traits simplement h\ue9rit\ue9s dont la
r\ue9sistance \ue0 la maladie de virus de m\ue8che \ue9taient
appropri\ue9s pour la s\ue9lection de fond. D'autres traits
incluaient la hauteur de plants et la taille de l'\ue9pis. Les
marqueurs SSR repr\ue9sent\ue9s sur les chromosomes 3,5,7,
respectivement et associ\ue9s aux traits quantitatifs loci (QTL)
conditionnant la r\ue9sistance dans le ma\ubfs \ue0 la maladie de
t\ue2che grise de feuilles ansi que l'intervalle de l'anthesis
jusqu'\ue0 la s\ue9cr\ue9tion du "silk" \ue9taient
appropri\ue9s pour \ue9valuation du g\ue9nome parent recurrent.
Les niveaux de prot\ue9ines z\ue9ines 27-kDa g \ue9taient
appropri\ue9s pour la s\ue9lection de fond pour la modification de
grains. Ceci pourra \ueatre utilis\ue9 \ue0 c\uf4t\ue9
d'autres z\ue9ines telles que les prot\ue9ines z\ue9ines 22 kDa
et 19 kDa
PREVALENCE OF ANGULAR LEAF SPOT DISEASE AND SOURCES OF RESISTANCE IN COMMON BEAN IN EASTERN DEMOCRATIC REPUBLIC OF CONGO
Angular leaf spot ( Pseudocercospora griseola Crous U, Brown) is one
of the most important diseases hindering common bean ( Phaseolus
vulgaris L.) production in the Great Lakes Region of Africa,
including the Democratic Republic of Congo. The disease causes extreme
yield losses, estimated at 384.2 tonnes per year, in Sub-Saharan
Africa. Little is known about the distribution, severity and incidence
of the disease and the effect of agronomic practices and environmental
factors on the disease prevalence in the country to facilitate
interventions. A field survey was conducted during two crop seasons,
February to June and September to January, in two main beans growing
zones of eastern DRC namely; sub-humid highland and sub-humid mid
altitude at low latitudes, in South and North Kivu, respectively.
Severity and incidence of angular leaf-spot and other occurring
diseases were assessed on common bean plants in farmers\u2019 fields.
Angular leaf spot in these fields had an average severity index (PSI)
of 49.9%. PSI was significantly different (P<0.05) between districts
and seasons. Using multiple regression analysis, independent variables:
growth stage, cropping system, districts and altitude were shown to
have significant influence on the observed PSI (P<0.05) with R2 =
96.2%. The highest severity (PSI=59.7%) was observed in Kabare
district, and the lowest in Uvira district (PSI=39.5%). Screening of a
set of 37 released common bean varieties in DRC using virulent Andean
and Mesoamerican isolates identified four resistant bean varieties; ARA
4, COD MLV 059, MLV 224/94B, LSA 144 and Mexico 54. Some of these
varieties possess useful traits, in addition to acceptable seed market
class, and are hence recommended as suitable parents for ALS resistant
variety development and promotion in ALS prone environments.La tache angulaire ( Pseudocercospora griseola Crous U, Brown) est
l\u2019une des maladies les plus importantes qui entravent la
production de haricot commun ( Phaseolus vulgaris L.) dans la
r\ue9gion des Grands Lacs d\u2019Afrique, y compris la
R\ue9publique D\ue9mocratique du Congo. La maladie provoque des
pertes de rendement extr\ueames, estim\ue9es \ue0 384.2 tonnes
par an en Afrique Sub-Saharienne. Ily a encore peu de connaissance sur
la distribution, la gravit\ue9 et l\u2019incidence de la maladie et
l\u2019effet des pratiques agronomiques et des facteurs environnement
aux sur la pr\ue9valence de la maladie dans le pays pour faciliter
les interventions. Une enqu\ueatesur le terrain a
\ue9t\ue9men\ue9e pendant deux saisons de r\ue9colte, de
F\ue9vrier \ue0 Juin et de Septembre \ue0 janvier, dans deux
zones principals de culture de haricots de l\u2019est de la RDC,
\ue0 savoir: Sous-humides de haute altitude et sous-humides \ue0
basse altitude, au Sud et au Nord-Kivu. La gravit\ue9 et
l\u2019incidence de la tache angulaire des feuilles et d\u2019autres
maladies ont \ue9t\ue9 \ue9valu\ue9es sur les plants de
haricots dans les champs des agriculteurs. Ces champs \ue9taient
infest\ue9s par la maladie, avec unindice de gravit\ue9 moyen (IPS)
de 49.9%. PSI \ue9tait significativement diff\ue9rent (P <0.05)
entre districts et saisons. En utilisant l\u2019analyse de
r\ue9gression multiple, les variables ind\ue9pendantes: stade de
croissance, syst\ue8me de culture, districts et altitude ont
montr\ue9 une influence significative sur le PSI observ\ue9 (P
<0.05) avec R2 = 96.2%. La s\ue9v\ue9rit\ue9 plus
\ue9lev\ue9e (PSI = 59.7%) a \ue9t\ue9 observ\ue9e dans le
district de Kabare et la plus faible dans le district d\u2019Uvira
(PSI = 39,5%). La s\ue9lection d\u2019un lot de 37
vari\ue9t\ue9s de haricot distribu\ue9es en RDC utilisant des
isolats virulents Andins et M\ue9soam\ue9ricains a permis
d\u2019identifier quatre vari\ue9t\ue9s de haricots
r\ue9sistants; ARA 4, COD MLV 059, MLV 224 / 94B, LSA 144 et Mexique
54. Certaines de ces vari\ue9t\ue9s pr\ue9sentent des traits
utiles en plus de son acceptabilit\ue9 sur lemarch\ue9 des
semences, et sont donc recommand\ue9s comme des parents
appropri\ue9s pour le d\ue9veloppement et la promotion des
vari\ue9t\ue9s r\ue9sistantes ALS
Potential for yield loss reduction and profitability assessment of pesticide control of groundnut leaf miner among soybean genotypes
Groundnut leaf miner (GLM) is currently a threat to soybean production
in Uganda due to the great yield losses as a result of the severe
damage it causes on leaves leading to reduced photosynthetic area. GLM
is a fairly new pest on soybean in Uganda, having initially been
observed in soybean fields in 2011 in eastern Uganda. The objective of
this study was to determine the yield loss caused by the groundnut leaf
miner and effectiveness and profitability of commonly used pesticides
for the control of the groundnut leaf miner ( Aproaerema modicella
Deventer) (GLM), when tested with popular soybean ( Glycine max )
genotypes grown in Uganda. In a split plot RCBD design, pesticide
protection (treated vs. untreated) formed the main plots; and six
commercial soybean varieties (Maksoy 1N, 2N, 3N, 4N, 5N; and Namsoy 4M)
as subplots. The study was done in two locations in eastern Uganda (Iki
Iki District Agricultural Training and Information Centre (Iki Iki
DATIC) and National Semi-Arid Resources Research Institute, Serere
(NaSARRI) with two planting rounds at Iki Iki. These sites were chosen
because they are hot spots for GLM. GLM severity and soybean yield were
significantly affected by the pesticide protection. Overall, percentage
grain yield losses caused by GLM on the different soybean varieties
ranged from 37.3% to 65.7% and the highest loss was displayed by Maksoy
5N. Grain yield loss recorded at Iki Iki DATIC (53.1%) was remarkably
higher than that recorded at the NaSARRI (49.1%). Economic analysis
showed marginal returns to be dependent on location, with the Iki Iki
DATIC having 0.6 and NaSARRI 1.1. This study has shown that the
groundnut leaf miner, a recently emergent pest of soybean is becoming a
big threat to soybean production and that chemical control alone may
not be economical in managing the pest.La mineuse de feuilles d\u2019arachide (MFA) constitue actuellement
une menace pour la production de soja en Ouganda en raison des pertes
de rendement consid\ue9rables dues aux d\ue9g\ue2ts importants
caus\ue9s aux feuilles, ce qui a entra\ueen\ue9 une
r\ue9duction de la surface photosynth\ue9tique. Le MFA est un
ravageur relativement nouveau sur le soja en Ouganda. Il avait
d\u2019abord \ue9t\ue9 observ\ue9 dans des champs de soja en
2011 dans l\u2019est de l\u2019Ouganda. L\u2019objectif de cette
\ue9tude \ue9tait de d\ue9terminer la perte de rendement
caus\ue9e par la mineuse de feuilles d\u2019arachide et
l\u2019efficacit\ue9 et la rentabilit\ue9 des pesticides
couramment utilis\ue9s pour lutter contre la mineuse de feuilles
d\u2019arachide ( Aproaerema modicella Deventer) (MFA),
lorsqu\u2019il \ue9tait test\ue9 avec du soja tr\ue8s
r\ue9pandu ( Glycine max ) g\ue9notypes cultiv\ue9s en Ouganda.
L\u2019essai a \ue9t\ue9 install\ue9 suivant un dispositif split
plot en parcelles divis\ue9es, la protection antiparasitaire
(trait\ue9e ou non trait\ue9e) constituait les parcelles
principales; et six vari\ue9t\ue9s commerciales de soja (Maksoy 1N,
2N, 3N, 4N, 5N; et Namsoy 4M) en sous-parcelles. L\u2019\ue9tude a
\ue9t\ue9 r\ue9alis\ue9e dans deux regions de l\u2019est de
l\u2019Ouganda (Centre de formation et d\u2019information agricoles
du district d\u2019Iki Iki (Iki Iki DATIC) et Institut national de
recherche sur les ressources semi-arides de Serere (NaSARRI), avec deux
fois de plantation \ue0 Iki Iki. Ces sites ont \ue9t\ue9 choisis
parceque ce sont des regions tr\ue8s menaces par MFA. La protection
contre les pesticides a eu un effet important sur la
s\ue9v\ue9rit\ue9 du MFA et le rendement du soja. Generalement,
le pourcentage de pertes de rendement en grain caus\ue9es par la sur
les diff\ue9rentes vari\ue9t\ue9s de soja variait de 37,3% \ue0
65,7% et la perte la plus \ue9lev\ue9e a \ue9t\ue9 montr\ue9e
par Maksoy 5N. La perte de rendement en grains trouv\ue9e \ue0 Iki
Iki DATIC (53,1%) \ue9tait remarquablement sup\ue9rieure \ue0
celle trouv\ue9e \ue0 NaSARRI (49,1%). L\u2019analyse
\ue9conomique a montr\ue9 que les rendements marginaux
d\ue9pendaient de la localisation, l\u2019Iki Iki DATIC \ue9tant
\ue0 0,6 et NaSARRI \ue0 1,1. Une \ue9tude a montr\ue9 que la
mineuse de feuilles d\u2019arachide, un ravageur du soja
r\ue9cemment apparu, constituait une menace majeure pour la
production de soja et que la lutte chimique \ue0 elle seule pouvait
ne pas \ueatre rentable pour lutter contre ce ravageur
Knowledge And Attitude Of Nigerian Ophthalmologists Towards Cornea Donation And Corneal Graft.
The aim of this study was to determine the attitude of practicing
Nigerian ophthalmologists towards cornea donation and corneal graft.
The responses of 160 ophthalmologists (specialists and senior
registrars) in Nigeria who responded to an appropriate questionnaire on
cornea donation at one of their National conferences attended mainly by
practicing ophthalmologists were analysed. Through the questionnaire,
the knowledge and attitude of the ophthalmologists towards cornea
donation and cornea graft in Nigeria were evaluated. The questionnaire
also included questions on donor materials from prisoners for
themselves and their close relatives. One hundred and sixty (160) of
the 191 ophthalmologists (84%) given the questionnaire responded. All
the respondents have adequate information on cornea donation and
corneal graft. Majority of them were favourably disposed to most of the
questions asked except when it came to carrying a donor card, signing
the donor form and the actual signing of the form. Only 34 (21%) of
ophthalmologists agreed to donate their cornea at death. It was found
that traditional beliefs, social implications and personal
considerations mainly influenced those who were not favourably disposed
to cornea donation and corneal graft. The majority of practicing
ophthalmologists in Nigeria are not favourably disposed to donating
their cornea at death
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