451 research outputs found
Seasonal changes in nematode faecal egg counts of sheep in Ethiopia
Describes the seasonal pattern of nematode faecal egg counts of sheep slaughtered at the Addis Ababa abattoir from July 1985 to June 1986. Presents data on strongyle and trichostrongyle faecal egg counts. Suggests possible strategic measures for th econtrol of gastrointestinal nematodes of sheep in central Ethiopia
Planning a Family:priorities and concerns in rural Tanzanmia
A fertility survey using qualitative and quantitative techniques described a high fertility setting (TFR 5.8) in southern Tanzania where family planning use was 16%. Current use was influenced by rising parity, educational level, age of last born child, breastfeeding status, a\ud
preference for longer than the mean birth interval (32 months), not being related to the household head, and living in a house with a tin roof. Three principal concerns amongst women were outlined from the findings. First, that there is a large unmet need for family planning services in the area particularly among teenagers for whom it is associated with induced abortion. Second, that family planning is being used predominantly for spacing but fears\ud
associated with it often curtail effective use. Third, that service provision is perceived to be lacking in two main areas — regularity of supply, and addressing rumours and fears associated with family planning. Reproductive health interventions in the area should ultimately be more\ud
widespread and, in particular, abortion is highlighted as an urgent issue for further research.\ud
The potential for a fast and positive impact is high, given the simplicity of the perceived needs of\ud
women from this study. (Afr J Reprod Health 2004; 8[2]:111-123)\u
Occurrence of rice yellow mottle virus resistance breaking isolates in lowland catchment zones of Uganda
Rice (Oryza spp; 2n=24.) production in Uganda and Africa in general, is seriously threatened by the Rice yellow mottle virus disease (RYMVD), a disease caused by Rice yellow mottle virus (RYMV) within the genus Sobemovirus; family Sobemoviridae. This study investigated the existence and distribution of resistance-breaking RYMV pathotype in the three major lowland rice catchment areas in Uganda. Four known rice accessions resistant to Rice yellow mottle virus (RYMV) namely; Gigante, Tog5672, Tog5674 and Tog5681, carrying resistant allele’s rymv1-2, rymv1-4 & RYMV3, rymv1-5 and rymv1-3, respectively, were tested for their response to different RYMV isolates. The isolates were collected from three major lowland rice catchment areas of Doho, Kibimba, and Olweny in Uganda. Out of 100 leaf samples collected from the field and assayed for RYMV and confirmed to be positive using RT-PCR, 83 isolates induced symptoms on IR64- the RYMV susceptible line. Seventy-seven (92.8%) isolates were able to overcome resistance in at least one of the four differential rice accessions, as confirmed by the presence of RYMV symptoms; while 6 (7.2%) isolates were asymptomatic. Variation in time (days) for symptom development post-inoculation (dpi) and AUDPC were observed. Symptoms appeared within 5-7 days on IR64; while it took on average 11, 18, 36, and 18 days to appear on Gigante, Tog5672, Tog5674 and Tog5681, respectively. The highest AUDPC was observed on IR64 (254.7); while the lowest was observed on Tog5681 (74.1). Two major patho-groups were observed; those that broke down resistance in Gigante only (25.3%) and Gigante & Tog5672 (33.7%). Five isolates from Doho (Budaka & Bugiri districts) and Kibimba (Butaleja district) catchment areas broke down RYMV resistance in three accessions i.e. (Tog5681, Gigante & Tog5672) and (Tog5674, Gigante & Tog5672), respectively. Resistance breaking isolates were confirmed in all the three sampled catchment zones, however, Doho and Kibimba had some unique isolates that broke down resistance in accessions carrying resistance allele rymv 1-3 and rymv1-5 in addition to rymv1-2. Results from this study showed that RYMV isolates in Uganda can break down resistance conferred by the rymv1-2 resistance gene allele. However, accessions Tog5681 and Tog5674 seem to hold stable RYMV resistance and, thus are recommended for RYMV breeding
\u3csup\u3e40\u3c/sup\u3eAr-\u3csup\u3e39\u3c/sup\u3eAr Age constraints on volcanism and tectonism in the Terror Rift of the Ross Sea, Antarctica
Volcanic sills and dikes inferred from seismic reflection profiles and geophysical studies of the Ross Sea are thought to be related to the rift basins in the region, and their emplacement to be coeval with extension. However, lack of precise geochronology in the Terror Rift of the Ross Sea region has left these inferred relationships poorly constrained and has hindered neotectonic studies, because of the large temporal gaps between seismic reflectors of known ages. New 40Ar/39Ar geochronology presented here for submarine volcanic rocks provides better age constraints for neotectonic interpretations within the Terror Rift. Several samples from seamounts yielded young ages between 156 ± 21 and 122 ± 26 Ka. These ages support interpretations that extension within the Terror Rift was active at least through the Pleistocene. Three evenly spaced samples from the lowermost 100 m of Franklin Island range in age from 3.28 ± 0.04 to 3.73 ± 0.05 Ma. These age determinations demonstrate that construction of a small volcanic edifice such as Franklin Island took at least several hundred thousand years, and therefore that much larger ones in the Erebus Volcanic Province are likely to have taken considerably longer than previously inferred. This warrants caution in applying a limited number of age determinations to define the absolute ages of events in the Ross Sea region
Production of friable embryogenic callus and regeneration of Ugandan farmer-preferred cassava genotypes
Generation of embryogenic callus is a key step in genetic engineering of many crop species, including cassava. Protocols for generation of friable embryogenic callus (FEC) have been lacking for Ugandan cassava genotypes, thereby delaying their genetic engineering for agronomic and other desirable traits. The objective of this study was to determine conditions suitable for production and regeneration of FEC in the Ugandan cassava genotypes; Aladu, Bukalasa and Ebwanateraka, and control cultivar 60444. Immature leaf lobe explants were established on Murashige and Skoog (MS) based media for initiation of organized embryogenic callus (OES). To produce FEC, resulting OES were established on Gresshoff and Doy based callus induction media with varying levels of sucrose, maltose, tyrosine, tryptophan, naphthalene acetic acid (NAA) under light and dark conditions. Subsequently, FEC was subcultured to MS-based embryo maturation and embryo regeneration media. All genotypes produced OES. All genotypes produced FEC except Bukalasa. The amino acid tyrosine favoured production of FEC in Aladu and Ebwanatereka, but not in 60444, while 20 g/L of sucrose trigged production of FEC in Aladu and 60444, but 40 g/L of sucrose was superior for Ebwanatereka. Media supplemented with 1 ml/L naphthalene acetic acid NAA facilitated embryo regeneration in Ebwanatereka and 60444, while Aladu responded better to 5 ml/L NAA. Light, tyrosine and sucrose were essential for FEC production in Uganda cultivars while NAA was required for regeneration of somatic embryos. Ability to produce FEC in these genotypes lays a foundation for their improvement through genetic transformation for the desired and agronomic traits.Key words: Cassava (Manihot esculenta Crantz), somatic embryogenesis, amino acids, carbon sources
Optimisation of in vitro techniques for Cassava brown streak virus elimination from infected cassava clones
Cassava brown streak disease (CBSD), caused by Cassava brown streak
virus (CBSV), is an economically important disease of cassava ( Manihot
esculenta Crantz) in East Africa. The objective of this study was to
optimise in vitro techniques for CBSV elimination from infected Ugandan
cassava cultivars. Using semi-solid half-strength Murashige and Skoog
(MS) basal medium, hormone concentration and heat treatment regimes
were optimised for micropropagation of farmer's preferred cassava
cultivars and CBSV elimination. Single nodes from young cassava stems
were cultured for four weeks on 1/2MS medium supplemented with 6-benzyl
amino purine (BAP) and 2,4-dichlorophenoxy acetic acid (2,4-D). The BAP
and 2,4-D concentration (mg 1-1) combinations used were 0.0 and 0.0,
0.5 and 0.1, 1.0 and 0.2, 1.5 and 0.3, and 2.0 and 0.4, respectively.
The optimum medium was used for in vitro thermotherapy using four
temperature regimes, namely 30-34, 34-38, 36-40 and 38-42 \ub0C for 8
hours darkness and 16 hours light, respectively, for four weeks. The
best plantlet growth in terms of height was observed on MS medium
supplemented with 0.5 mg 1-1 BAP and 0.1 mg 1-1 2,4-D. Highest CBSV
elimination efficiency of 40%, with 49% plantlet survival was observed
at 36 \ub1C for 8 hours darkness and 40 oC for 16 hours light. These
results indicate that in vitro techniques can greatly enhance CBSV
elimination and, thus, provide a means of CBSD management through
dissemination and conservation of popular but CBSD susceptible
cultivars.La maladie de la striure brune du manioc (CBSD) caus\ue9e par le
virus de la striure brune (CBSV), est une maladie \ue9conomiquement
importante du manioc ( Manihot esculenta Crantz) en Afrique de
l'Est. L'objectif de cette \ue9tude \ue9tait d'optimiser les
techniques in vitro pour l'\ue9limination du CBSV des cultivars
ougandais infect\ue9s. En utilisant le m\ue9dium basal semi-solid
half strength Murashige and Skoog, la concentration d'hormone et les
regimes de traitement de chaleur \ue9taient optimis\ue9s pour la
micropropagation des cultivars de manioc pr\ue9f\ue9r\ue9s par
les fermiers et l'\ue9limination du CBSV. Les nodes simples des
jeunes tiges de manioc \ue9taient cultiv\ue9s pendant quatre
semaines sur le m\ue9dium 1/2 MS suppl\ue9ment\ue9s avec 6-benzyl
amino purine (BAP) et 2,4-dichlorophenoxy acetic acid. Les combinaisons
de concentrations (mg 1-1) de BAP et de 2.4-D utilis\ue9es
\ue9taient 0.0 et 0.0, 0.5 et 0.1, 1.0 et 0.2, 1.5 et 0.3, et 2.0 et
0.4, respectivement. Le m\ue9dium optimum \ue9tait utilis\ue9
pour la thermoth\ue9rapie utilisant quatre regimes de
temp\ue9rature dont 30-34, 34-38, 36-40 et 38-42 \ub0C pendant 8
heures en obscurit\ue9 et 16 heures sous lumi\ue8re, respectivement
pendant quatre semaines. La meilleure croissance en hauteur des
plantules \ue9tait observ\ue9e sur le m\ue9dium MS
suppl\ue9ment\ue9 avec 0.5 mg 1-1 BAP et 0.1 mg 1-1 2,4-D.
L'efficience la plus \ue9lev\ue9e de 40 % en terme
d'\ue9limination du CBSV, avec 49 % de la survie de plantules
\ue9tait observ\ue9e \ue0 36 \ub0C pendant 8 heures sous
obscurit\ue9 et 40 \ub0C pendant 16 heures sous lumi\ue8re. Les
r\ue9sultats indiquent que les techniques in vitro peuvent grandement
promouvoir l'\ue9limination du CBSV et offrent ainsi un moyen de
gestion de CBSD \ue0 travers la dissemination et la conservation des
cultivars aussi populaires que susceptibles au SBSD
New radiometric evidence for the age and thermal history of the metamorphic rocks of the Ruby and Nixon Fork Terranes, West-Central Alaska
https://deepblue.lib.umich.edu/bitstream/2027.42/155805/1/Dillon_et_al_1985_New_radiometric.pd
Food security through virus indexing, tissue culture and genetic engineering of underutilized crops
Occurrence of rice yellow mottle virus resistance breaking isolates in lowland catchment zones of Uganda
Rice ( Oryza spp; 2n=24.) production in Uganda and Africa in general,
is seriously threatened by the Rice yellow mottle virus disease
(RYMVD), a disease caused by Rice yellow mottle virus (RYMV) within the
genus Sobemovirus; family Sobemoviridae. This study investigated the
existence and distribution of resistance-breaking RYMV pathotype in the
three major lowland rice catchment areas in Uganda. Four known rice
accessions resistant to Rice yellow mottle virus (RYMV) namely;
Gigante, Tog5672, Tog5674 and Tog5681, carrying resistant
allele\u2019s rymv1-2, rymv1-4 & RYMV3, rymv1-5 and rymv1-3,
respectively, were tested for their response to different RYMV
isolates. The isolates were collected from three major lowland rice
catchment areas of Doho, Kibimba, and Olweny in Uganda. Out of 100 leaf
samples collected from the field and assayed for RYMV and confirmed to
be positive using RT-PCR, 83 isolates induced symptoms on IR64- the
RYMV susceptible line. Seventy-seven (92.8%) isolates were able to
overcome resistance in at least one of the four differential rice
accessions, as confirmed by the presence of RYMV symptoms; while 6
(7.2%) isolates were asymptomatic. Variation in time (days) for symptom
development post-inoculation (dpi) and AUDPC were observed. Symptoms
appeared within 5-7 days on IR64; while it took on average 11, 18, 36,
and 18 days to appear on Gigante, Tog5672, Tog5674 and Tog5681,
respectively. The highest AUDPC was observed on IR64 (254.7); while the
lowest was observed on Tog5681 (74.1). Two major patho-groups were
observed; those that broke down resistance in Gigante only (25.3%) and
Gigante & Tog5672 (33.7%). Five isolates from Doho (Budaka &
Bugiri districts) and Kibimba (Butaleja district) catchment areas broke
down RYMV resistance in three accessions i.e. (Tog5681, Gigante &
Tog5672) and (Tog5674, Gigante & Tog5672), respectively. Resistance
breaking isolates were confirmed in all \ua0the three sampled
catchment zones, however, Doho and Kibimba had some unique isolates
that broke down resistance in accessions carrying resistance allele
rymv 1-3 and rymv1-5 in addition to rymv1-2. Results from this study
showed that RYMV isolates in Uganda can break down resistance conferred
by the\ua0rymv1-2 resistance gene allele. However, accessions Tog5681
and Tog5674 seem to hold stable RYMV resistance and, thus are
recommended for RYMV breeding.La production de riz ( Oryza spp ; 2n=24.) en Ouganda et en Afrique
en g\ue9n\ue9ral, est s\ue9rieusement menac\ue9e par la maladie
du virus de la marbrure jaune du riz (RYMVD), une maladie caus\ue9e
par le virus de la marbrure jaune du riz (RYMV) du genre Sobemovirus ;
famille des Sobemoviridae. Cette \ue9tude a examin\ue9
l\u2019existence et la distribution du pathotype RYMV qui brise la
r\ue9sistance dans les trois principaux bassins versants de riz de
plaine en Ouganda. Les quatre accessions de riz connues
r\ue9sistantes au \ua0virus\ua0de la panachure\ua0jaune du
riz\ua0(RYMV, Rice yellow mottle\ua0virus) \ue0 savoir; Gigante,
Tog5672, Tog5674 et Tog5681, portant respectivement les all\ue8les
r\ue9sistants rymv1-2, rymv1-4 & rymv3, rymv1-5 et rymv1-3, ont
\ue9t\ue9 test\ue9s pour leur r\ue9ponse \ue0 diff\ue9rents
isolats de RYMV. Les isolats ont \ue9t\ue9 collect\ue9s dans les
trois principaux bassins versants du riz de plaine de Doho, Kibimba et
Olweny en Ouganda. Sur les 100 \ue9chantillons des feuilles
pr\ue9lev\ue9s sur le terrain et test\ue9s pour le RYMV et
confirm\ue9s positifs par RT-PCR, 83 isolats ont induit des
sympt\uf4mes sur IR64, la lign\ue9e sensible au RYMV. Les
soixante-dix-sept (92,8 %) isolats ont r\ue9ussi \ue0 surmonter la
r\ue9sistance dans au moins une des quatre accessions du riz
diff\ue9rentielles, comme le confirme la pr\ue9sence des
sympt\uf4mes du RYMV\ua0; tandis que 6 (7,2 %) isolats \ue9taient
asymptomatiques. Une variation dans le temps (jours) pour le
d\ue9veloppement des sympt\uf4mes apr\ue8s l\u2019inoculation
(dpi, development post-inoculation) et l\u2019AUDPC a \ue9t\ue9
observ\ue9e. Les sympt\uf4mes sont apparus dans les 5 \ue0 7
jours sur IR64\ua0; alors qu\u2019il a fallu en moyenne 11, 18, 36
et 18 jours pour appara\ueetre sur Gigante, Tog5672, Tog5674 et
Tog5681, respectivement. L\u2019AUDPC le plus \ue9lev\ue9 a
\ue9t\ue9 observ\ue9 sur IR64 (254,7); tandis que l\u2019AUDPC
le plus bas a \ue9t\ue9 observ\ue9 sur Tog5681 (74,1). Deux
patho-groupes principaux ont \ue9t\ue9 observ\ue9s; ceux qui ont
bris\ue9 la r\ue9sistance dans les Gigante uniquement (25,3%) et
Gigante & Tog5672 (33,7%). Les cinq isolats des bassins versants de
Doho (districts de Budaka et Bugiri) et de Kibimba (district de
Butaleja) ont bris\ue9 la r\ue9sistance au RYMV dans trois
accessions, \ue0 savoir (Tog5681, Gigante et Tog5672) et (Tog5674,
Gigante et Tog5672), respectivement. Des isolats brisant la
r\ue9sistance ont \ue9t\ue9 confirm\ue9s dans les trois zones
de captage \ue9chantillonn\ue9es, cependant, Doho et Kibimba
avaient des isolats uniques qui brisaient la r\ue9sistance dans des
accessions portant les all\ue8les de r\ue9sistance rymv1-3 et
rymv1-5 en plus de rymv1-2. Les r\ue9sultats de cette \ue9tude ont
montr\ue9 que les isolats de RYMV en Ouganda peuvent briser la
r\ue9sistance conf\ue9r\ue9e par l\u2019all\ue8le du g\ue8ne
de r\ue9sistance rymv1-2. Cependant, les accessions Tog5681 et
Tog5674 semblent d\ue9tenir une r\ue9sistance stable au RYMV et
sont donc recommand\ue9es pour la s\ue9lection du RYMV
KINET: A social marketing programme of treated nets and net treatment for malaria control in Tanzania, with evaluation of child health and long-term survival
We present a large-scale social marketing programme of insecticide-treated nets in 2 rural districts in south-western Tanzania (population 350 000) and describe how the long-term child health and survival impact will be assessed. Formative and market research were conducted in order to understand community perceptions, knowledge, attitudes and practice with respect to the products to be socially marketed. We identified Zuia Mbu (Kiswahili for ‘prevent mosquitoes') as a suitable brand name for both treated nets and single-dose insecticide treatment sachets. A mix of public and private sales outlets is used for distribution. In the first stage of a stepped introduction 31 net agents were appointed and trained in 18 villages: 15 were shop owners, 14 were village leaders, 1 was a parish priest and 1 a health worker. For net treatment 37 young people were appointed in the same villages and trained as agents. Further institutions in both districts such as hospitals, development projects and employers were also involved in distribution. Promotion for both products was intense and used a variety of channels. A total of 22 410 nets and 8072 treatments were sold during the first year: 18 months after launching, 46% of 312 families with children aged under 5 years reported that their children were sleeping under treated nets. A strong evaluation component in over 50 000 people allows assessment of the long-term effects of insecticide-treated nets on child health and survival, anaemia in pregnancy, and the costs of the intervention. This evaluation is based on cross-sectional surveys, and case-control and cohort studie
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