Publications by authors named "Polly Walker"

Systematic reviews have highlighted that repeated severe wasting after receiving treatment is likely to be common, but standardised measurement is needed urgently. The Council of Research & Technical Advice for Acute Malnutrition (CORTASAM) released recommendations on standard measurement of relapse (wasting within 6 months after exiting treatment as per recommended discharge criteria), regression (wasting within 6 months after exiting treatment before reaching recommended discharge criteria) and reoccurrence (wasting after 6 months of exit from treatment as per recommended discharge criteria). We provide a theoretical framework of post-treatment relapse and regression to severe wasting to guide discussions, risk factor analyses, and development and evaluations of interventions.

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Background: The global scale-up of community health workers (CHWs) depends on supportive management and supervision of this expanding cadre. Existing tools fail to incorporate the perspective of the CHW (i.e.

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Background: Evidence suggests that community-based interventions that promote improved home-based practices and care-seeking behaviour can have a large impact on maternal and child mortality in regions where rates are high. We aimed to assess whether an intervention package based on the WHO Integrated Management of Childhood Illness handbook and community mobilisation could reduce under-5 mortality in rural Guinea-Bissau, where the health service infrastructure is weak.

Methods: We did a non-masked cluster-randomised controlled trial (EPICS) in the districts of Tombali and Quinara in Guinea-Bissau.

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Background: Guinea-Bissau is a small country in West Africa with a population of 1.7 million. The WHO and UNICEF reported an under-five child mortality of 203 per 1000, the 10th highest amongst 192 countries.

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Annual global aquaculture production has more than tripled within the past 15 years, and by 2015, aquaculture is predicted to account for 39% of total global seafood production by weight. Given that lack of adequate nutrition is a leading contributor to the global burden of disease, increased food production through aquaculture is a seemingly welcome sign. However, as production surges, aquaculture facilities increasingly rely on the heavy input of formulated feeds, antibiotics, antifungals, and agrochemicals.

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Objective: Animal feeding practices in the United States have changed considerably over the past century. As large-scale, concentrated production methods have become the predominant model for animal husbandry, animal feeds have been modified to include ingredients ranging from rendered animals and animal waste to antibiotics and organoarsenicals. In this article we review current U.

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The human immunodeficiency virus type 1 (HIV-1) negative factor, or Nef, has a variety of functions that are important in viral pathogenesis. Sequence analysis has identified nef mutations that are linked to the rate of disease progression in adults and children infected with HIV-1 subtype B. Here we have sequenced and analyzed HIV-1 subtype C nef sequences from 34 children with rapid (RP) or slow progressing (SP) disease and identified polymorphisms associated with disease stage including motifs involved in specific pathogenic functions.

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V3 serotyping is a technique for determining HIV-1 genetic subtype based on the binding of antibodies from patient sera or plasma to synthetic V3 peptides derived from subtype consensus sequences. Variation in the performance of this assay has been attributed to V3 sequence heterogeneity, the degree of which varies with patient disease progression, virus co-receptor usage, and genetic subtype. This study assessed the performance of a competitive peptide enzyme immunoassay (cPEIA) in samples from HIV-1 subtype C infected patients with varying disease profiles, including those with syncytium (SI) and non-syncytium-inducing (NSI) viruses.

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The genotypes and biological phenotypes of HIV-1 isolates obtained from 40 perinatally infected children in South Africa were analyzed. This included 15 infants who had HIV-related symptoms, most of whom died within 2 years of birth (rapid progressors), and 25 children who survived between 4 and 9 years with varying signs of disease (slow progressors). Heteroduplex mobility assays and sequence analysis confirmed that within the env and gag regions, all isolates were HIV-1 subtype C.

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The high level of meat and saturated fat consumption in the USA and other high-income countries exceeds nutritional needs and contributes to high rates of chronic diseases such as cardiovascular disease, diabetes mellitus and some cancers. Affluent citizens in middle- and low-income countries are adopting similar high-meat diets and experiencing increased rates of these same chronic diseases. The industrial agricultural system, now the predominant form of agriculture in the USA and increasingly world-wide, has consequences for public health owing to its extensive use of fertilisers and pesticides, unsustainable use of resources and environmental pollution.

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The human immunodeficiency virus (HIV) pandemic continues to grow at an alarming rate, with a further 5 million new infections in 2003. Some 3.5 million of these were in sub-Saharan Africa, where approximately 70% of the world's HIV-positive population resides.

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To address the incongruence between the expectations of nursing service and education in California, the Education Industry Interface Task Force of the California Strategic Planning Committee for Nursing developed descriptions to assist employers and educators in clearly differentiating practice and educational competencies. The completion of the Competency-Based Role Differentiation Model resulted in the need to test the model for its utility in the service setting, in education, and for career planning for nurses. Three alpha demonstration sites were selected based on representative geographical regions of California.

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The pilot study to demonstrate the utility of the CBRDM in the practice setting was successful. Using a matrix evaluation tool based on the model's competencies, evaluators were able to observe specific performance behaviors of senior nursing students and new graduates at either the novice or competent levels. The study faced the usual perils of pilot studies, including small sample size, a limited number of items from the total CBRDM, restricted financial resources, inexperienced researchers, unexpected barriers, and untested evaluation tools.

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Rosetting is a property of many malaria parasite species that has been linked to virulence in the major species infecting humans, Plasmodium falciparum. Here, the basic properties of rosettes in the rodent malaria laboratory model, P. chabaudi, were studied with a view to future studies on the role of rosetting in malaria parasite virulence and transmission.

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The industrial agriculture system consumes fossil fuel, water, and topsoil at unsustainable rates. It contributes to numerous forms of environmental degradation, including air and water pollution, soil depletion, diminishing biodiversity, and fish die-offs. Meat production contributes disproportionately to these problems, in part because feeding grain to livestock to produce meat--instead of feeding it directly to humans--involves a large energy loss, making animal agriculture more resource intensive than other forms of food production.

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