925 research outputs found

    Some partial-unit-memory convolutional codes

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    The results of a study on a class of error correcting codes called partial unit memory (PUM) codes are presented. This class of codes, though not entirely new, has until now remained relatively unexplored. The possibility of using the well developed theory of block codes to construct a large family of promising PUM codes is shown. The performance of several specific PUM codes are compared with that of the Voyager standard (2, 1, 6) convolutional code. It was found that these codes can outperform the Voyager code with little or no increase in decoder complexity. This suggests that there may very well be PUM codes that can be used for deep space telemetry that offer both increased performance and decreased implementational complexity over current coding systems

    Constructions for finite-state codes

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    A class of codes called finite-state (FS) codes is defined and investigated. These codes, which generalize both block and convolutional codes, are defined by their encoders, which are finite-state machines with parallel inputs and outputs. A family of upper bounds on the free distance of a given FS code is derived from known upper bounds on the minimum distance of block codes. A general construction for FS codes is then given, based on the idea of partitioning a given linear block into cosets of one of its subcodes, and it is shown that in many cases the FS codes constructed in this way have a d sub free which is as large as possible. These codes are found without the need for lengthy computer searches, and have potential applications for future deep-space coding systems. The issue of catastropic error propagation (CEP) for FS codes is also investigated

    Impact Properties of Hemp Fibre Reinforced Cementitious Composites

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    The construction industry has seen an incredibly fast increase in utilizing natural fibres for making low-cost building materials to achieve sustainable construction. One of such applications is natural fibre-reinforced cementitious materials for either structural or non-structural purpose. Impact properties are engineering properties received increasing attentions from engineering community for structural materials. This research therefore studies impact resistance of hemp fibre reinforced cementitious composites at early ages. Hemp fibre with various lengths, 10 mm and 20 mm, are utilized to reinforce cementitious materials. Hemp fibre reinforced cementitious composite slabs were tested under repeating dropping mass till failure at the age of 7, 14 and 28 days. Cracking behaviour, impact resistance, absorbed impact energy and survived impact blows upon failure are qualitatively/quantitatively analysed. It has been found that 20 mm-long hemp fibre reinforcement leads to higher impact resistance, more absorbed impact energy and survived more impact blows upon failure. Cementitious composite slabs reinforced by 20 mm-long hemp fibres exhibit higher impact crack resistance ratio than those reinforced by 10 mm-long fibres. Longer fibres are more effective in inhibiting the growth of micro-cracks and blunting the propagation of micro-cracks before they join up to form macro cracks leading to ultimate failure

    Lipid core peptide/poly(lactic-co-glycolic acid) as a highly potent intranasal vaccine delivery system against Group A streptococcus

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    Rheumatic heart disease represents a leading cause of mortality caused by Group A Streptococcus (GAS) infections transmitted through the respiratory route. Although GAS infections can be treated with antibiotics these are often inadequate. An efficacious GAS vaccine holds more promise, with intranasal vaccination especially attractive, as it mimics the natural route of infections and should be able to induce mucosal IgA and systemic IgG immunity. Nanoparticles were prepared by either encapsulating or coating lipopeptide-based vaccine candidate (LCP-1) on the surface of poly(lactic-co-glycolic acid) (PLGA). In vitro study showed that encapsulation of LCP-1 vaccine into nanoparticles improved uptake and maturations of antigen-presenting cells. The immunogenicity of lipopeptide incorporated PLGA-based nanoparticles was compared with peptides co-administered with mucosal adjuvant cholera toxin B in mice upon intranasal administration. Higher levels of J14-specific salivary mucosal IgA and systemic antibody IgG titres were observed for groups immunized with encapsulated LCP-1 compared to LCP-1 coated nanoparticles or free LCP-1. Systemic antibodies obtained from LCP-1 encapsulated PLGA NPs inhibited the growth of bacteria in six different GAS strains. Our results show that PLGA-based lipopeptide delivery is a promising approach for rational design of a simple, effective and patient friendly intranasal GAS vaccine resulting in mucosal IgA response

    The use of biomedicine, complementary and alternative medicine, and ethno-medicine for the treatment of epilepsy among people of South Asian origin in the UK

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    Studies have shown that a significant proportion of people with epilepsy use complementary and alternative medicine (CAM). CAM use is known to vary between different ethnic groups and cultural contexts; however, little attention has been devoted to inter-ethnic differences within the UK population. We studied the use of biomedicine, complementary and alternative medicine, and ethnomedicine in a sample of people with epilepsy of South Asian origin living in the north of England

    Has the epidemic of allergic contact dermatitis due to Methylisothiazolinone reached its peak?

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    Methylisothiazolinone (MI) is a preservative used in many household and industrial products. There has been an unprecedented global rise in allergic contact dermatitis (ACD) from its presence in personal care products (PCPs). In 2005 changes to EU legislation allowed MI, used in combination with methylchloroisothiazolinone (MCI), to be used at concentrations of up to 100ppm, 25 times higher than previously permitted. MI was also permitted to be used alone, whereas previously it was only used in combination with MCI in a 3:1 mix.(1) This resulted in the chain of events that led to the current MI allergy epidemic.By 2010, the first case series of ACD to MI as a cosmetic allergen was published. This article is protected by copyright. All rights reserved.</p

    Isolation and identification of pathogenic bacteria from ready-to -eat fast foods in Al-Quwayiyah, Kingdom of Saudi Arabia

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    Food-borne pathogens are becoming a globally formidable health problem and perceived as a major health concern in the Kingdom of Saudi Arabia (KSA). Contamination ensued through unclean raw food materials and particles, use of polluted water, unhygienic preparation processes and use of contaminated containers. Herein, the prevalence of food-borne pathogens in ready-to-eat (RTE) fast foods from fifteen different food eateries such as 7 restaurants, 6 cafeterias and 2 two college canteens in Al-Quwayiyah, Riyadh Region of Saudi Arabia was studied. Microbiological analysis of 155 fast food samples which included, Vegetable salad, Falafel, Kibtha and Shawarma. The isolates were detected using biochemical tests and API 20E and slide agglutination test were conducted for Salmonella spp. detection. Bacterial growth was found in all food samples tested. Moreover, the test also showed high levels of total aerobic count: vegetable salad 6.34+0.03, falafel 5.79 + 0.18, kibtha 5.06 +0.02 and shawarma 3.54 + 0.13. Organisms isolated include Salmonella spp. (15%), Escherichia coli (18%) and Staphylococcus aureus (7%). Salmonella is one of the most virulent pathogen implicated in food-borne disease outbreaks. There are numerous transmission routes for Salmonellosis, but the majority of the human infections are derived from consumption of contaminated poultry products. Consistently, Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Heidelberg are the three most frequent serotypes recovered from humans each year. Serologically identified Salmonella serotypes from RTE fast food samples were Salmonella Typhimurium with 65%, the most predominant one compared to Salmonella Enteritidis that was 35%. The bacterial count of vegetable salad, falahfel, kibtha was statistically significant when compared with Shawarma (p &lt; 0.05). This result indicated that most of the ready-to-eat food samples examined in the study did not meet any bacteriological quality standard as recommended by The New South Wales (NSW) Food Authority to be &lt;5.0 log10 CFU g−1 and, therefore, it poses potential risks to consumers. Ready- to- eat fast foods must be cooked and served to the consumers with all hygienic measures.Keywords: foodborne pathogen, microbial quality, Ready- to- eat fast foods, Al-QuwayiyahAfr. J. Food Agric. Nutr. Dev. 2019; 19(3): 14739-1475

    Anti-Tumour Effect In Vitro of Lymphocytes and Macrophages from Mice Treated with Corynebacterium Parvum

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    Cells from the spleen, lymph node, peripheral blood and peritoneal exudate of mice treated with C. parvum were tested for their ability to inhibit tumour growth in vitro. The peritoneal exudate cells from C. parvum treated mice were extremely effective in inhibiting tumour growth whereas the spleen and peripheral blood cells were only moderately so. In contrast, the lymph node cells caused only a modest inhibition of tumour growth at a very high effector to target cell ratio. Spleen cells from normal mice also exerted a moderate anti-tumour effect

    On the existence of optimum cyclic burst- correcting codes

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    On-going collaborative priority-setting for research activity: a method of capacity building to reduce the research-practice translational gap

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    Background: International policy suggests that collaborative priority setting (CPS) between researchers and end users of research should shape the research agenda, and can increase capacity to address the research-practice translational gap. There is limited research evidence to guide how this should be done to meet the needs of dynamic healthcare systems. One-off priority setting events and time-lag between decision and action prove problematic. This study illustrates the use of CPS in a UK research collaboration called Collaboration and Leadership in Applied Health Research and Care (CLAHRC). Methods: Data were collected from a north of England CLAHRC through semi-structured interviews with 28 interviewees and a workshop of key stakeholders (n = 21) including academics, NHS clinicians, and managers. Documentary analysis of internal reports and CLAHRC annual reports for the first two and half years was also undertaken. These data were thematically coded. Results: Methods of CPS linked to the developmental phase of the CLAHRC. Early methods included pre-existing historical partnerships with on-going dialogue. Later, new platforms for on-going discussions were formed. Consensus techniques with staged project development were also used. All methods demonstrated actual or potential change in practice and services. Impact was enabled through the flexibility of research and implementation work streams; ‘matched’ funding arrangements to support alignment of priorities in partner organisations; the size of the collaboration offering a resource to meet project needs; and the length of the programme providing stability and long term relationships. Difficulties included tensions between being responsive to priorities and the possibility of ‘drift’ within project work, between academics and practice, and between service providers and commissioners in the health services. Providing protected ‘matched’ time proved difficult for some NHS managers, which put increasing work pressure on them. CPS is more time consuming than traditional approaches to project development. Conclusions: CPS can produce needs-led projects that are bedded in services using a variety of methods. Contributing factors for effective CPS include flexibility in use and type of available resources, flexible work plans, and responsive leadership. The CLAHRC model provides a translational infrastructure that enables CPS that can impact on healthcare systems
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