51 research outputs found

    Farmers, consumers and gatekeepers and their attitudes towards biotechnology

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    In 1999, a project to develop insect resistance maize for Africa was launched. Social scientists from this team used participatory rural appraisals, consumer studies, a baseline and gatekeeper survey to study the awareness and attitudes towards biotechnology among farmers, consumers and gatekeepers. Farmers’ awareness of biotechnology was very low (12.7%). Awareness on genetically modified (GM) crops among consumers was also found to be low, although it was higher among urban consumers (38%) than among rural ones (31%). Radio was the main source of information. A large majority of consumers agreed to statements expressing the benefits of biotechnology such as increasing productivity. However, they had environmental and health concerns. Half of the urban consumers expressed concerns about the environment, in particular, loss of biodiversity. In contrast, awareness about GM was found to be high for the gatekeepers (87% for millers, and 79% for supermarkets). A majority of gatekeepers in the food industry were concerned that GM food could cause allergic reactions or antibiotic-resistant diseases. Almost all consumers were willing to purchase GM maize meal at the same price. Of those in the industry, more than two thirds, were hesitant to use them preferring to make the decision on a case-by-case basis.Key words: Biotechnology, genetically modified (GM), consumer, attitudes, gatekeeper

    Injection safety knowledge and practices among clinical health care workers in Garissa provincial general hospital

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    Background: The World Health Organization estimates that approximately 16 billion injections are administered in developing countries annually. Injection safety is therefore critical in preventing occupational exposure and infection from blood borne pathogens, hence prevention is a vital part of any comprehensive plan for protecting health workers, patients and maintaining a safe environment.Objective: To determine the knowledge and practice of injection safety among clinical healthcare workers at the Garissa Provincial General Hospital.Design: A cross-sectional descriptive study.Setting: The Garissa provincial General Hospital from September 2011 to July 2012.Results: Injection safety knowledge was high with a score of 12.65 (SD ± 2.3) out of the total of 16 items. Appropriate injection safety practices were reported by most of the respondents. The level of knowledge was not significantly associated with respondents’ demographic characteristics(p>0.05), but was significantly associated with hand washing practice(p<0.05).Inferences were made on an appropriate injection safety practices like non-recapping of needles, hand washing and proper waste management. Drug administration practice varied in the different departments (p=0.043) and recapping of needles was significantly associated with training (p=0.047), designation (p=0.02) and area of deployment (p=0.017).Conclusion: Knowledge on injection safety was high but reported and observed practices were below the set standard. Risky practices such as recapping used syringes, re-use of disposable syringes and overfilling of sharp boxes were observed. There was insufficient provision of injection safety equipment, Poor waste handling and inadequate personal protective gear. Over prescription of unnecessary injections was widespread

    Long-range predictability of extratropical climate and the length of day

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    This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: Atmospheric angular momentum data from the model predictions are available from https://doi.org/10.5281/zenodo.7003975. Observed length-of-day data are available from https://www.iers.org/IERS/EN/Home/home_node.html.Code availability: The code we used to calculate atmospheric angular momentum is available from https://zenodo.org/record/7003975Angular momentum is fundamental to the structure and variability of the atmosphere and therefore has an important influence on regional weather and climate. Total atmospheric angular momentum is also directly related to the rotation rate of the Earth and, hence, the length of day. However, the long-range predictability of fluctuations in the length of the day and atmospheric angular momentum is unknown. Here we show that fluctuations in atmospheric angular momentum and the length of day are predictable out to more than a year ahead and that this provides an atmospheric source of long-range predictability for surface climate. Using ensemble forecasts from a dynamical climate model, we demonstrate long-range predictability of signals in the atmospheric angular momentum field that propagate slowly and coherently polewards due to wave–mean flow interaction within the atmosphere. These predictable signals are also shown to precede changes in extratropical climate via the North Atlantic Oscillation and the extratropical jet stream. These results extend the lead time for length-of-day predictions, provide a source of long-range predictability from within the atmosphere and provide a link between geodesy and climate prediction.Newton FundMet Office Hadley Centre Climate ProgrammeEuropean Union Horizon 2020Natural Environment Research Council (NERC)China National Key Research and Development Program on Monitoring, Early Warning and Prevention of Major Natural Disaste

    Defining the Conformational Features of Anchorless, Poorly Neuroinvasive Prions

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    Infectious prions cause diverse clinical signs and form an extraordinary range of structures, from amorphous aggregates to fibrils. How the conformation of a prion dictates the disease phenotype remains unclear. Mice expressing GPI-anchorless or GPI-anchored prion protein exposed to the same infectious prion develop fibrillar or nonfibrillar aggregates, respectively, and show a striking divergence in the disease pathogenesis. To better understand how a prion's physical properties govern the pathogenesis, infectious anchorless prions were passaged in mice expressing anchorless prion protein and the resulting prions were biochemically characterized. Serial passage of anchorless prions led to a significant decrease in the incubation period to terminal disease and altered the biochemical properties, consistent with a transmission barrier effect. After an intraperitoneal exposure, anchorless prions were only weakly neuroinvasive, as prion plaques rarely occurred in the brain yet were abundant in extracerebral sites such as heart and adipose tissue. Anchorless prions consistently showed very high stability in chaotropes or when heated in SDS, and were highly resistant to enzyme digestion. Consistent with the results in mice, anchorless prions from a human patient were also highly stable in chaotropes. These findings reveal that anchorless prions consist of fibrillar and highly stable conformers. The additional finding from our group and others that both anchorless and anchored prion fibrils are poorly neuroinvasive strengthens the hypothesis that a fibrillar prion structure impedes efficient CNS invasion

    Complex folding and misfolding effects of deer-specific amino acid substitutions in the β2-α2 loop of murine prion protein

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    The β2–α2 loop of PrPC is a key modulator of disease-associated prion protein misfolding. Amino acids that differentiate mouse (Ser169, Asn173) and deer (Asn169, Thr173) PrPC appear to confer dramatically different structural properties in this region and it has been suggested that amino acid sequences associated with structural rigidity of the loop also confer susceptibility to prion disease. Using mouse recombinant PrP, we show that mutating residue 173 from Asn to Thr alters protein stability and misfolding only subtly, whilst changing Ser to Asn at codon 169 causes instability in the protein, promotes oligomer formation and dramatically potentiates fibril formation. The doubly mutated protein exhibits more complex folding and misfolding behaviour than either single mutant, suggestive of differential effects of the β2–α2 loop sequence on both protein stability and on specific misfolding pathways. Molecular dynamics simulation of protein structure suggests a key role for the solvent accessibility of Tyr168 in promoting molecular interactions that may lead to prion protein misfolding. Thus, we conclude that ‘rigidity’ in the β2–α2 loop region of the normal conformer of PrP has less effect on misfolding than other sequence-related effects in this region

    A longitudinal survey of African animal trypanosomiasis in domestic cattle on the Jos Plateau, Nigeria:prevalence, distribution and risk factors

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    BACKGROUND: Trypanosomiasis is a widespread disease of livestock in Nigeria and a major constraint to the rural economy. The Jos Plateau, Nigeria was free from tsetse flies and the trypanosomes they transmit due to its high altitude and the absence of animal trypanosomiasis attracted large numbers of cattle-keeping pastoralists to inhabit the plateau. The Jos Plateau now plays a significant role in the national cattle industry, accommodating approximately 7% of the national herd and supporting 300,000 pastoralists and over one million cattle. However, during the past two decades tsetse flies have invaded the Jos Plateau and animal trypanosomiasis has become a significant problem for livestock keepers. METHODS: In 2008 a longitudinal two-stage cluster survey on the Jos Plateau. Cattle were sampled in the dry, early wet and late wet seasons. Parasite identification was undertaken using species-specific polymerase chain reactions to determine the prevalence and distribution bovine trypanosomiasis. Logistic regression was performed to determine risk factors for disease. RESULTS: The prevalence of bovine trypanosomiasis (Trypanosoma brucei brucei, Trypanosoma congolense savannah, Trypanosoma vivax) across the Jos Plateau was found to be high at 46.8% (39.0 – 54.5%) and significant, seasonal variation was observed between the dry season and the end of the wet season. T. b. brucei was observed at a prevalence of 3.2% (1% – 5.5%); T. congolense at 27.7% (21.8% - 33.6%) and T. vivax at 26.7% (18.2% - 35.3%). High individual variation was observed in trypanosomiasis prevalence between individual villages on the Plateau, ranging from 8.8% to 95.6%. Altitude was found to be a significant risk factor for trypanosomiasis whilst migration also influenced risk for animal trypanosomiasis. CONCLUSIONS: Trypanosomiasis is now endemic on the Jos Plateau showing high prevalence in cattle and is influenced by seasonality, altitude and migration practices. Attempts to successfully control animal trypanosomiasis on the Plateau will need to take into account the large variability in trypanosomiasis infection rates between villages, the influence of land use, and husbandry and management practices of the pastoralists, all of which affect the epidemiology of the disease

    Biochemical Properties of Highly Neuroinvasive Prion Strains

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    Infectious prions propagate from peripheral entry sites into the central nervous system (CNS), where they cause progressive neurodegeneration that ultimately leads to death. Yet the pathogenesis of prion disease can vary dramatically depending on the strain, or conformational variant of the aberrantly folded and aggregated protein, PrPSc. Although most prion strains invade the CNS, some prion strains cannot gain entry and do not cause clinical signs of disease. The conformational basis for this remarkable variation in the pathogenesis among strains is unclear. Using mouse-adapted prion strains, here we show that highly neuroinvasive prion strains primarily form diffuse aggregates in brain and are noncongophilic, conformationally unstable in denaturing conditions, and lead to rapidly lethal disease. These neuroinvasive strains efficiently generate PrPSc over short incubation periods. In contrast, the weakly neuroinvasive prion strains form large fibrillary plaques and are stable, congophilic, and inefficiently generate PrPSc over long incubation periods. Overall, these results indicate that the most neuroinvasive prion strains are also the least stable, and support the concept that the efficient replication and unstable nature of the most rapidly converting prions may be a feature linked to their efficient spread into the CNS

    Phase Ia Clinical Evaluation of the Safety and Immunogenicity of the Plasmodium falciparum Blood-Stage Antigen AMA1 in ChAd63 and MVA Vaccine Vectors

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    Traditionally, vaccine development against the blood-stage of Plasmodium falciparum infection has focused on recombinant protein-adjuvant formulations in order to induce high-titer growth-inhibitory antibody responses. However, to date no such vaccine encoding a blood-stage antigen(s) alone has induced significant protective efficacy against erythrocytic-stage infection in a pre-specified primary endpoint of a Phase IIa/b clinical trial designed to assess vaccine efficacy. Cell-mediated responses, acting in conjunction with functional antibodies, may be necessary for immunity against blood-stage P. falciparum. The development of a vaccine that could induce both cell-mediated and humoral immune responses would enable important proof-of-concept efficacy studies to be undertaken to address this question

    Using viral vectors as gene transfer tools (Cell Biology and Toxicology Special Issue: ETCS-UK 1 day meeting on genetic manipulation of cells)

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    In recent years, the development of powerful viral gene transfer techniques has greatly facilitated the study of gene function. This review summarises some of the viral delivery systems routinely used to mediate gene transfer into cell lines, primary cell cultures and in whole animal models. The systems described were originally discussed at a 1-day European Tissue Culture Society (ETCS-UK) workshop that was held at University College London on 1st April 2009. Recombinant-deficient viral vectors (viruses that are no longer able to replicate) are used to transduce dividing and post-mitotic cells, and they have been optimised to mediate regulatable, powerful, long-term and cell-specific expression. Hence, viral systems have become very widely used, especially in the field of neurobiology. This review introduces the main categories of viral vectors, focusing on their initial development and highlighting modifications and improvements made since their introduction. In particular, the use of specific promoters to restrict expression, translational enhancers and regulatory elements to boost expression from a single virion and the development of regulatable systems is described
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