Binary and ternary pyrotechnic systems containing manganese, molybdenum, barium peroxide and strontium peroxide

Barium peroxide was selected as oxidant in a fundamental physico-chemical study of binary pyrotechnic systems on account of its apparently simple decomposition stoichiometry. With this selection, the choice of fuel was governed by the requirements of a self-sustaining reaction at combustion temperatures below the melting point of the platinum/rhodium thermocouples (∼1760°C) used for recording temperature-time profiles during burning, and at burning rates not exceeding the response of the sensors used to monitor combustion. Both manganese and molybdenum metal powders satisfied the above requirements. Strontium peroxide was also available as an oxidant and so the combustion of binary metal/oxidant systems using both fuels and both BaO₂ and SrO₂ oxidants was investigated. The Mn/BaO₂, MoBaO₂ and Mn/SrO₂ systems burnt over a wide range of compositions, but the range of ignitable compositions for the Mo/SrO₂ system was very limited. The linear burning rates, for all these systems, ranged from 2 to 12 mm s⁻¹ and burning rates were increased by the use of smaller particle-sizes of fuel and greater loading pressures. Inert additives generally decreased the burning rate. Temperature-time profiles were recorded for all the compositions which sustained combustion. Kinetic parameters were estimated from the shapes of these profiles using procedures developed by Hill et al and Boddington and Laye. Activation energies derived from the profiles were low (3 to 40 kJ mol⁻¹) and support suggestions that reactions at high temperatures are controlled by diffusion processes. Thermal analysis was used to identify the processes occurring in the four systems. The main exothermic events were observed to correspond approximately with the onset of oxidant decomposition. A pre-ignition reaction was tentatively identified in the Mn/BaO₂ system. Oxidation of the metal fuels was generally incomplete, probably because of the formation of protective layers of product. Activation energies, derived from thermal analysis results, were in the range of from 70 to 720 kJ mol⁻¹. Ternary systems containing either mixed fuels or mixed oxidants were also examined. No interactions hetween the fuels or between the oxidants were observed. Other techniques used included bomb calorimetry, measurement of thermal conductivity, X-ray powder diffraction, infrared spectroscopy and scanning electron microscopy

Strategies for building trust with farmers: the case of Bt maize in South Africa

<p>Abstract</p> <p>Background</p> <p>In 1999, South Africa became the first African country to approve commercial production of subsistence genetically modified (GM) maize. The introduction of GM crop technology is often met with skepticism by stakeholders including farmers. The involvement of the private sector in this process can further breed mistrust or misperceptions. To examine these issues more closely, the objective of this case study was to understand the role of trust in the public-private partnership (PPP) arrangement involved in the development of <it>Bacillus thuringiensis</it> (Bt) maize in South Africa.</p> <p>Methods</p> <p>We conducted semi-structured, face-to-face interviews to obtain stakeholders’ understanding of <it>trust</it> in general as well as in the context of agricultural biotechnology (agbiotech) PPPs. A thematic analysis of the interview transcripts, documents, reports and research articles was conducted to generate insights into the challenges to, and practices for, building trust among the partners and with the public.</p> <p>Results</p> <p>The findings of this study are organized into four main lessons on trust building. First, as the end users of GM technology, farmers must be engaged from the start of the project through field demonstrations and educational activities. Second, an effective technology (i.e., the seed) is key to the success of an agbiotech PPP. Third, open communication and full disclosure between private sector companies and government regulatory bodies will build trust and facilitate the regulatory processes. Fourth, enforcing good agronomic practices, including appropriate management of the refuge areas, will serve the interests of both the farmers and the seed companies.</p> <p>Conclusions</p> <p>Trust has proven to be a critical factor determining the success of the Bt maize project in South Africa. Distrust of the private sector and of GM technology were cited as major barriers to building trust. The trust-building practices described in this case study have often served to overcome these barriers; however, erosion of trust was also present. The success of the project has been, and will continue to be, dependent upon the concerted effort of the farmers, government, and private sector players in the establishment and maintenance of trust.</p

Non-modifiable risk factors for stress fractures in military personnel undergoing training: A systematic review

A fracture, being an acquired rupture or break of the bone, is a significant and debilitating injury commonly seen among athletes and military personnel. Stress fractures, which have a repetitive stress aetiology, are highly prevalent among military populations, especially those undergoing training. The primary aim of this review is to identify non-modifiable risk factors for stress fractures in military personnel undergoing training. A systematic search was conducted of three major databases to identify studies that explored risk factors for stress fractures in military trainees. Critical appraisal, data extraction, and a narrative synthesis were conducted. Sixteen articles met the eligibility criteria for the study. Key non-modifiable risk factors identified were prior stress fracture and menstrual dysfunction, while advancing age and race other than black race may be a risk factor. To reduce the incidence of stress fractures in military trainees, mitigating modifiable risk factors among individuals with non-modifiable risk factors (e.g., optimising conditioning for older trainees) or better accommodating non-modifiable factors (for example, extending training periods and reducing intensity to facilitate recovery and adaptation) are suggested, with focus on groups at increased risk identified in this review

Prognostic models for identifying adults with intellectual disabilities and mealtime support needs who are at greatest risk of respiratory infection and emergency hospitalisation.

$\textbf{Background}$ Among adults with intellectual disabilities (ID), problems with eating, drinking and swallowing (EDS), and an associated need for mealtime support, are common, with an estimated 15% of adults known to specialist ID services requiring mealtime support. We set out to identify which adults with ID who receive mealtime support are at an increased risk of $\textit{respiratory infections}$ and $\textit{emergency hospitalisation related to EDS problems}$. $\textbf{Method}$ An exploratory, prospective cohort study was undertaken in the East of England. At baseline, structured interviews with the caregivers of 142 adults with ID and any type of mealtime support needs were used to gather information on health and support needs over the previous 12 months. These interviews were repeated at follow-up, 12 months later. The resulting dataset, covering a 24-month period, was analysed with logistic regression, using model averaging to perform sensitivity analysis, and backwards step-wise variable selection to identify the most important predictors. $\textbf{Results}$ Individuals with $\textit{a history of respiratory infections}$ (in the first year of study), those who had $\textit{epilepsy}$ and those with $\textit{caregiver-reported difficulty swallowing}$ were most likely to have $\textit{respiratory infections}$ in the second year. Adults with $\textit{increasing mealtime support needs, epilepsy}$ and/or $\textit{full mealtime support needs}$ (fed mainly or entirely by a caregiver or enterally) were at increased risk of $\textit{emergency hospitalisation}$ for EDS-related problems. $\textbf{Conclusions}$ Our findings highlight the importance of carefully monitoring health issues experienced by adults with ID and EDS problems, as well as their eating, drinking and swallowing skills. However, the models developed in this exploratory research require validation through future studies addressing the EDS problems commonly experienced by adults with ID and their implications for health outcomes and quality of life. Further research into the relationship between epilepsy and EDS problems would provide much-needed insight into the complex relationship between the two areas.This paper presents independent research commissioned by the National Institute for Health Research (NIHR) under its Research for Patient Benefit (RfPB) programme (grant reference number PB-PG-0906-11098). The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. Simon R. White was supported by the Medical Research Council (Unit Programme number U105292687)

Music and the brain: disorders of musical listening

The study of the brain bases for normal musical listening has advanced greatly in the last 30 years. The evidence from basic and clinical neuroscience suggests that listening to music involves many cognitive components with distinct brain substrates. Using patient cases reported in the literature, we develop an approach for understanding disordered musical listening that is based on the systematic assessment of the perceptual and cognitive analysis of music and its emotional effect. This approach can be applied both to acquired and congenital deficits of musical listening, and to aberrant listening in patients with musical hallucinations. Both the bases for normal musical listening and the clinical assessment of disorders now have a solid grounding in systems neuroscience

Raltegravir with Optimized Background Therapy for Resistant HIV-1 Infection

Background: Raltegravir (MK-0518) is an inhibitor of human immunodeficiency virus type 1 (HIV-1) integrase active against HIV-1 susceptible or resistant to older antiretroviral drugs. Methods: We conducted two identical trials in different geographic regions to evaluate the safety and efficacy of raltegravir, as compared with placebo, in combination with optimized background therapy, in patients infected with HIV-1 that has triple-class drug resistance in whom antiretroviral therapy had failed. Patients were randomly assigned to raltegravir or placebo in a 2:1 ratio. Results: In the combined studies, 699 of 703 randomized patients (462 and 237 in the raltegravir and placebo groups, respectively) received the study drug. Seventeen of the 699 patients (2.4%) discontinued the study before week 16. Discontinuation was related to the study treatment in 13 of these 17 patients: 7 of the 462 raltegravir recipients (1.5%) and 6 of the 237 placebo recipients (2.5%). The results of the two studies were consistent. At week 16, counting noncompletion as treatment failure, 355 of 458 raltegravir recipients (77.5%) had HIV-1 RNA levels below 400 copies per milliliter, as compared with 99 of 236 placebo recipients (41.9%, P<0.001). Suppression of HIV-1 RNA to a level below 50 copies per milliliter was achieved at week 16 in 61.8% of the raltegravir recipients, as compared with 34.7% of placebo recipients, and at week 48 in 62.1% as compared with 32.9% (P<0.001 for both comparisons). Without adjustment for the length of follow-up, cancers were detected in 3.5% of raltegravir recipients and in 1.7% of placebo recipients. The overall frequencies of drug-related adverse events were similar in the raltegravir and placebo groups. Conclusions: In HIV-infected patients with limited treatment options, raltegravir plus optimized background therapy provided better viral suppression than optimized background therapy alone for at least 48 weeks. (ClinicalTrials.gov numbers, NCT00293267 and NCT00293254.

Subgroup and Resistance Analyses of Raltegravir for Resistant HIV-1 Infection

Background: We evaluated the efficacy of raltegravir and the development of viral resistance in two identical trials involving patients who were infected with human immunodeficiency virus type 1 (HIV-1) with triple-class drug resistance and in whom antiretroviral therapy had failed. Methods: We conducted subgroup analyses of the data from week 48 in both studies according to baseline prognostic factors. Genotyping of the integrase gene was performed in raltegravir recipients who had virologic failure. Results: Virologic responses to raltegravir were consistently superior to responses to placebo, regardless of the baseline values of HIV-1 RNA level; CD4 cell count; genotypic or phenotypic sensitivity score; use or nonuse of darunavir, enfuvirtide, or both in optimized background therapy; or demographic characteristics. Among patients in the two studies combined who were using both enfuvirtide and darunavir for the first time, HIV-1 RNA levels of less than 50 copies per milliliter were achieved in 89% of raltegravir recipients and 68% of placebo recipients. HIV-1 RNA levels of less than 50 copies per milliliter were achieved in 69% and 80% of the raltegravir recipients and in 47% and 57% of the placebo recipients using either darunavir or enfuvirtide for the first time, respectively. At 48 weeks, 105 of the 462 raltegravir recipients (23%) had virologic failure. Genotyping was performed in 94 raltegravir recipients with virologic failure. Integrase mutations known to be associated with phenotypic resistance to raltegravir arose during treatment in 64 patients (68%). Forty-eight of these 64 patients (75%) had two or more resistance-associated mutations. Conclusions: When combined with an optimized background regimen in both studies, a consistently favorable treatment effect of raltegravir over placebo was shown in clinically relevant subgroups of patients, including those with baseline characteristics that typically predict a poor response to antiretroviral therapy: a high HIV-1 RNA level, low CD4 cell count, and low genotypic or phenotypic sensitivity score. (ClinicalTrials.gov numbers, NCT00293267 and NCT00293254.

Evidence-based Kernels: Fundamental Units of Behavioral Influence

This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior

Strategies for building trust with farmers: the case of Bt maize in South Africa

Abstract Background In 1999, South Africa became the first African country to approve commercial production of subsistence genetically modified (GM) maize. The introduction of GM crop technology is often met with skepticism by stakeholders including farmers. The involvement of the private sector in this process can further breed mistrust or misperceptions. To examine these issues more closely, the objective of this case study was to understand the role of trust in the public-private partnership (PPP) arrangement involved in the development of Bacillus thuringiensis (Bt) maize in South Africa. Methods We conducted semi-structured, face-to-face interviews to obtain stakeholders’ understanding of trust in general as well as in the context of agricultural biotechnology (agbiotech) PPPs. A thematic analysis of the interview transcripts, documents, reports and research articles was conducted to generate insights into the challenges to, and practices for, building trust among the partners and with the public. Results The findings of this study are organized into four main lessons on trust building. First, as the end users of GM technology, farmers must be engaged from the start of the project through field demonstrations and educational activities. Second, an effective technology (i.e., the seed) is key to the success of an agbiotech PPP. Third, open communication and full disclosure between private sector companies and government regulatory bodies will build trust and facilitate the regulatory processes. Fourth, enforcing good agronomic practices, including appropriate management of the refuge areas, will serve the interests of both the farmers and the seed companies. Conclusions Trust has proven to be a critical factor determining the success of the Bt maize project in South Africa. Distrust of the private sector and of GM technology were cited as major barriers to building trust. The trust-building practices described in this case study have often served to overcome these barriers; however, erosion of trust was also present. The success of the project has been, and will continue to be, dependent upon the concerted effort of the farmers, government, and private sector players in the establishment and maintenance of trust