315 research outputs found
An epidemiological study of recent outbreaks of Gumboro disease in Ghana
A study to assess the epidemiological factors responsible for the recent outbreaks of infectious bursal disease (IBD) in Accra and Kumasi, between October and December 2002 and January to April 2003, was conducted. Case report records at Veterinary Diagnostic Laboratories were examined for IBD cases. Farm investigations were carried out using a combination of questionnaire and interviews to obtain information on the disease situation on farms, where the outbreaks had occurred. The highest occurrence of the disease was recorded between March and April 2003, with Accra showing the highest number of cases in March, coinciding with the Easter season. Day-old chicks imported into the country succumbed more easily to the disease than those produced locally. There was an association between IBD and the chicken type that was significant (P < 0.05) in cockerels and layers. Chickens vaccinated twice were more likely to be protected from the disease than those not vaccinated or vaccinated only once. The prevalence of the disease was also influenced by the age of the chickens with a rise in susceptibility with age from 3 weeks to 6 weeks old. The results of the study indicate that the factors studied, namely source of day old chicks, bird type, vaccination history, and age of chicks at the time of outbreak influenced outbreaks of IBD and are likely to contribute to the endemicity of infectious bursal disease in the poultry producing areas of Ghana. It is recommended that stringent biosecurity measures be observed on poultry farms to control the disease in the country
Isolation and characterization of infectious bursal disease virus (IBDV) field strains and pathotypes in Ghana
Isolation and characterisation of Ghanaian field IBD virus were undertaken as part of a comprehensive study to establish an efficacious vaccination programme against the disease in the country. Bursal homogenates wereprepared from chickens that died of IBD in five different locations of the country. Batches of 11-day-old Specific Antibody Negative (SAN) embryonating eggs were inoculated with 0.2 ml of homogenate each on the chorioallantoic membrane. The eggs were incubated and candleddaily, and all embryonic deaths were examined for gross IBD lesions. In addition, batches of 3-week-old SAN chickens were inoculated intra-occularly with 10 μl of the bursal homogenate and observed over 10 days for clinical signs and gross lesions of IBD. Pathotyping of the virus isolates was done by the biological method, using groups of 10, 6-week-old SAN chickens and confirmed by the reverse transcriptase-polymerase chainreaction-restriction fragment length polymorphism (RTPCR- RFLP) technique. Embryos inoculated with homogenates from all five locations died 3 to 5 days pest inoculation (PI), showing characteristic IBD lesionsof extensive haemorrhages, congestion of limbs and stunted growth. Inoculated 3-week-old SAN chickens showed 100 per cent cumulative mortality, enlarged haemorrhagic and oedematous bursae, and haemorrhages in the breast and thigh muscles. Six-week-old SANchickens inoculated with bursal homogenates showed similar lesions. One isolate LV/G19 selected and standardized for viral challenge studies had an ELD50 value of 106.3. The SAN chickens challenged with thisisolate were more susceptible between the ages of 3 and 6 weeks, but morbidity and mortality were seen up to 10 weeks of age. This study confirms the presence of the very virulent Infectious Bursal Disease Virus (vvIBDV) in Ghana and the urgent need for its control
Early selection for yield in robusta coffee based on juvenile growth traits
Variety development, particularly for tree crops is a long-term
exercise requiring significant resource investments, over many years of
evaluation. Identification of traits at early growth stages that are
predictive of future performance would facilitate the breeding process.
The objective of this study was to assess the value of juvenile trunk
cross-sectional area (TCSA) and number of laterals for selecting
high-yielding Robusta coffee ( Coffea canephora ) genotypes, early in
a breeding programme. Seventy-two Robusta coffee clones developed by
either ortet selection, from previous progeny trials/clonal trials
carried out at the Cocoa Research Institute of Ghana (CRIG), were
planted in 2011 in a randomised complete-block design with five
replications, at CRIG\u2019s experimental fields. Juvenile TCSA and
number of laterals were effective predictors of yield. Genotypes that
combined small TCSA and less number of laterals at the juvenile growth
phase had the lowest cumulative yields, and vice versa. TCSA was
significantly associated with yearly yields (2015: r = 0.49, P <
0.001; 2017: r = 0.35, P < 0.001) and cumulative yield (r = 0.41, P
< 0.001). Similarly, a significant (P < 0.001) correlation was
observed between juvenile number of laterals and yearly yields (2015: r
= 0.58, 2016: r = 0.24; 2017: r = 0.48), and cumulative yield (r =
0.57, P < 0.001). A selection index that combines large juvenile
TCSA and many number of laterals has the potential of identifying
productive genotypes early in a Robusta coffee breeding programme.Le d\ue9veloppement des vari\ue9t\ue9s, en particulier pour les
cultures arboricoles, est un exercice \ue0 long terme qui
n\ue9cessite des ressources importantes investissements, au cours de
nombreuses ann\ue9es d\u2019\ue9valuation. Identification des
traits aux premiers stades de croissance qui sont une pr\ue9vision
des performances futures faciliterait le processus de s\ue9lection.
L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer la
valeur de la section transversale du tronc juv\ue9nile (TCSA) et le
nombre de travers\ue9es pour s\ue9lection de g\ue9notypes de
caf\ue9 Robusta ( Coffea canephora ) \ue0 haut rendement, au
d\ue9but d\u2019un programme de s\ue9lection. Soixante-douze
clones de caf\ue9 Robusta ont \ue9t\ue9 mis au point soit par
s\ue9lection, soit \ue0 partir d\u2019essais ant\ue9rieurs sur
la descendance / essais clonaux r\ue9alis\ue9s \ue0
l\u2019Institut de recherche sur le cacao du Ghana (CRIG) ont
\ue9t\ue9 plant\ue9s en 2011 dans un conception de blocs complets
randomis\ue9s avec cinq r\ue9p\ue9titions, sur les champs
exp\ue9rimentaux de CRIG. TCSA juv\ue9nile et le nombre de
lat\ue9raux \ue9taient des pr\ue9dicteurs efficaces du rendement.
Des g\ue9notypes combinant de petites TCSA et un nombre moins
\ue9lev\ue9 de plantes lat\ue9rales \ue0 la phase de croissance
juv\ue9nile pr\ue9sentait les rendements cumulatifs les plus bas,
et inversement. Le TCSA \ue9tait associ\ue9 de mani\ue8re
significative aux rendements annuels (2015: r = 0,49, P <0,001;
2017: r = 0,35, P <0,001) et rendement cumul\ue9 (r = 0,41, P
<0,001). De m\ueame, une corr\ue9lation significative (P
<0,001) a \ue9t\ue9 observ\ue9e entre le nombre de
lat\ue9rales juv\ue9niles et les rendements annuels (2015: r =
0,58, 2016: r = 0,24; 2017: r = 0,48), et rendement cumul\ue9 (r =
0,57, P <0,001). Un index de s\ue9lection associant une grande
TCSA juv\ue9nile et de nombreuses nombre de produits lat\ue9raux a
le potentiel d\u2019identifier des g\ue9notypes productifs t\uf4t
dans un caf\ue9 Robusta programme d\u2019\ue9levage
Early Life Microcirculatory Plasticity and Blood Pressure Changes in Low Birth Weight Infants Born to Normotensive Mothers: A Cohort Study.
BACKGROUND: Capillary rarefaction (CR) is an established hallmark of essential hypertension (EH). The aim of this study was to examine early changes in capillary density (CD) and blood pressure (BP) in low birth weight (LBW) infants who are at risk of developing EH in later life. METHODS: We studied 77 LBW infants and 284 normal birth weight (NBW) infants, all born to mothers with normotension, in a longitudinal multicenter study. Intravital capillaroscopy was used to measure functional basal capillary density (BCD) and maximal capillary density (MCD) at birth, 3, 6, and 12 months. RESULTS: We found that LBW infants, born preterm and at term, had a significantly higher CD at birth, then underwent significant CR in the 1st 3 months culminating in a CD similar to that seen in NBW infants. NBW infants showed a gradual reduction in CD between birth and 12 months. Non-Caucasian ethnicity and preterm birth were significant predictors of a higher CD at birth. Systolic BP in NBW infants increased significantly from birth to 3 months, and we identified a significant negative correlation between systolic BP and MCD. CONCLUSIONS: This study has identified a process of early "accelerated capillary remodeling" in LBW infants, which corrects their higher CD at birth. This remodeling is unlikely to explain the CR seen in adult individuals with, or at risk of developing EH. Further follow-up studies are required to determine the timing and mechanisms involved in CR, which is likely to occur after the 1st year of life but before early adulthood
On-farm cocoa yields increase with canopy cover of shade trees in two agro-ecological zones in Ghana
Article purchased; Published online: 05 April 2018Despite Ghana’s large contribution to global cocoa production, average yields are low. Policymakers and practitioners are calling for implementation of a climate smart strategy by increasing yields and augmenting shade tree cover in cocoa systems. However, there have been few studies in West Africa on the relationship between shade and cocoa yield under field conditions. The objective of this study was to determine the effect of shade tree cover and other factors on on-farm cocoa yields over a four-year period. The study was conducted on 86 farm plots of 8–28 years’ cocoa trees with varied canopy cover (CC) in Ashanti and Western regions of Ghana. A linear mixed model analysis showed that yields increased significantly with increased CC of shade trees, and indicated a doubling of yields when going from zero to approximately 30% crown cover. Fertilizer use gave a yield increase of 7%. Farms located in Western region had higher yields compared to Ashanti, and cocoa systems on short fallows had lower yields than farms cultivated on recent forest clearings and old fallows. Fungicide use, seed sources and land ownership had no significant effects on yield. We conclude that for a sustainable climate-smart cocoa agenda, promotion of shade trees is key
Between crime and colony: Interrogating (im)mobilities aboard the convict ship
Recent literature in carceral geography has attended to the importance of mobilities in interrogating the experience and control of spaces of imprisonment, detention and confinement. Scholars have explored the paradoxical nature of incarcerated experience as individuals oscillate between moments of fixity and motion as they are transported to/from carceral environments. This paper draws upon the convict ship – an example yet to gain attention within these emerging discussions – which is both an exemplar of this paradox and a lens through which to complicate understandings of carceral (im)mobilities. The ship is a space of macro-movement from point A to B, whilst simultaneously a site of apparent confinement for those aboard who are unable to move beyond its physical parameters. Yet, we contend that all manner of mobilities permeate the internal space of the ship. Accordingly, we challenge the binary thinking that separates moments of fixity from motion and explore the constituent parts that shape movement. In paying attention to movements in motion on the ship, we argue that studies of carceral mobility must attend to both methods of moving in the space between points A and B; as micro, embodied and intimate (im)mobilities are also played out within large-scale regimes of movement
Diagnostics for COVID-19: A case for field-deployable, rapid molecular tests for community surveillance
Across the globe, the outbreak of the COVID-19 pandemic is causing distress with governments doing everything in their power to contain the spread of the novel coronavirus (SARS-CoV-2) to prevent morbidity and mortality. Actions are being implemented to keep health care systems from being overstretched and to curb the outbreak. Any policy responses aimed at slowing down the spread of the virus and mitigating its immediate effects on health care systems require a firm basis of information about the absolute number of currently infected people, growth rates, and locations/hotspots of infections. The only way to obtain this base of information is by conducting numerous tests in a targeted way. Currently, in Ghana, there is a centralized testing approach, that takes 4-5 days for samples to be shipped and tested at central reference laboratories with results communicated to the district, regional and nationalstakeholders. This delay in diagnosis increases the risk of ongoing transmission in communities and vulnerable institutions. We have validated, evaluated and deployed an innovative diagnostic tool on a mobile laboratory platform to accelerate the COVID-19 testing. A preliminary result of 74 samples from COVID-19 suspected cases has a positivity rate of 12% with a turn-around time of fewer than 3 hours from sample taking to reporting of results, significantly reducing the waiting time from days to hours, enabling expedient response by the health system for contact tracing to reduce transmission and additionally improving case management
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Molecular Characterization and Immuno-Reactivity Patterns of a Novel Plasmodium falciparum Armadillo-Type Repeat Protein, PfATRP.
Nearly half of the genes in the Plasmodium falciparum genome have not yet been functionally investigated. We used homology-based structural modeling to identify multiple copies of Armadillo repeats within one uncharacterized gene expressed during the intraerythrocytic stages, PF3D7_0410600, subsequently referred to as P. falciparum Armadillo-Type Repeat Protein (PfATRP). Soluble recombinant PfATRP was expressed in a bacterial expression system, purified to apparent homogeneity and the identity of the recombinant PfATRP was confirmed by mass spectrometry. Affinity-purified α-PfATRP rabbit antibodies specifically recognized the recombinant protein. Immunofluorescence assays revealed that α-PfATRP rabbit antibodies reacted with P. falciparum schizonts. Anti-PfATRP antibody exhibited peripheral staining patterns around the merozoites. Given the localization of PfATRP in merozoites, we tested for an egress phenotype during schizont arrest assays and demonstrated that native PfATRP is inaccessible on the surface of merozoites in intact schizonts. Dual immunofluorescence assays with markers for the inner membrane complex (IMC) and microtubules suggest partial colocalization in both asexual and sexual stage parasites. Using the soluble recombinant PfATRP in a screen of plasma samples revealed that malaria-infected children have naturally acquired PfATRP-specific antibodies
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Intracranial aneurysms in Ghanaian adults
Objective: To document the location, size, and multiplicity of intracranial aneurysms in Ghanaians who have un-dergone digital subtraction angiography (DSA) at a single centre in Accra, Ghana.
Design: We conducted a retrospective observational review of the medical records of all patients diagnosed with intracranial aneurysms on DSA
Setting: Patients' medical records at Euracare Advanced Diagnostic and Heart Centre were reviewed between March 2018 and March 2020. Participants: Thirty-one patients were identified with various intracranial aneurysms (IAs) within the study period. Patients' ages, sex, and types of IAs were extracted using a checklist and analysed using Microsoft Excel for Win-dows 2016.
Interventions: None
Main outcome measures: The prevalence of types and distribution of intracranial aneurysms.
Results: The age range of the patients was 26-76 years, with a mean age of 45.5±14.3 years. The mean age of men and women with IA was 45.5 ±15.9 years and 46.7 51.3±12.9 years, respectively. The most common IAs were located in the posterior communicating artery (PCOM) at 54.8% (95%CI: 36.0, 72.7), followed by the anterior communicating (ACOM), which constituted 32.3% (95%CI: 16.7, 51.4). The majority, 89.2% (33/37) of these aneurysms were less than 7mm in diameter. Single aneurysms were present in 25 (80.6%).
Conclusion: The most common IAs were found in the PCOM and ACOM, and IAs tend to rupture at a younger age and smaller size among the Ghanaian adults examined. Early detection and treatment of IAs less than 7mm in diameter is recommended
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Contrast Medium Use in Computed Tomography for Patients Presenting with Headache: 4-year Retrospective Two-Center Study in Central and Western Regions of Ghana
BACKGROUND: Contrast medium (CM) administration during computed tomography (CT) enhances the accuracy in the detection and interpretation of abnormalities. Evidence from literature also validate the essence of CM in imaging studies. CT, by virtue of its ubiquity, ease of use, speed, and lower financial footprint, is usually the first investigation in cases of headache. Through a multicenter retrospective analysis, we compared findings of contrast-enhanced CT (CECT) to noncontrast-enhanced CT (NCECT) head examinations among patients presenting with headache.
METHODS: A multicenter retrospective analysis of four years' CT head examination data at two radiology centers located in Central and Western Regions of Ghana were reviewed. Records of patients who presented with headache as principal complaint between January 2017 and December 2020 were reviewed. A total of 477 records of patients with headache were identified, retrieved and evaluated. A Chi-square test and Fisher exact test were used to compare the CECT and NCECT groups. Binary logistic regression analysis was computed to assess association between CECT and each CT findings. Statistical significance was considered at p < 0.05 with a 95% confidence interval.
RESULTS: A significant proportion of the patients was females (51.8% in CECT and 60% in NCECT). The NCECT group (40.06 ± 14.76 years) was relatively older than the CECT group (38.43 ± 17.64 years). There was a significant difference between the CECT and NCECT in terms of age (p=0.002) and facility CT was performed (p < 0.0001). The rate of abnormalities was higher in CECT (43.5%, 166/382) compared NCECT (37.9%, 36/95). There was no significant association between CT head findings and contrast enhancement.
CONCLUSION: CECT examination accounted for 5.6% increase in the detection of head abnormalities. Efforts required to establish local standard operation procedures (SOPs) for contrast medium use especially in CT head examinations. Further studies to improve the knowledge of agents, mechanism of action, and safety of contrast media used among practitioners in Ghana is recommended
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