194 research outputs found

    n-fold sub-implicative ideals and n-fold sub-commutative ideals of BCI-algebras

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    On n-Fold Positive Implicative Artinian and Noetherian BCI-Algebras

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    A scoping review of market links between value chain actors and small-scale producers in developing regions

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    Sustainable Development Goal 2 aims to end hunger, achieve food and nutrition security and promote sustainable agriculture by 2030. This requires that small-scale producers be included in, and benefit from, the rapid growth and transformation under way in food systems. Small-scale producers interact with various actors when they link with markets, including product traders, logistics firms, processors and retailers. The literature has explored primarily how large firms interact with farmers through formal contracts and resource provision arrangements. Although important, contracts constitute a very small share of smallholder market interactions. There has been little exploration of whether non-contract interactions between small farmers and both small- and large-scale value chain actors have affected small farmers’ livelihoods. This scoping review covers 202 studies on that topic. We find that non-contract interactions, de facto mostly with small and medium enterprises, benefit small-scale producers via similar mechanisms that the literature has previously credited to large firms. Small and medium enterprises, not just large enterprises, address idiosyncratic market failures and asset shortfalls of small-scale producers by providing them, through informal arrangements, with complementary services such as input provision, credit, information and logistics. Providing these services directly supports Sustainable Development Goal 2 by improving farmer welfare through technology adoption and greater productivity

    Probing background ionization: Positive streamers with varying pulse repetition rate and with a radioactive admixture

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    Positive streamers need a source of free electrons ahead of them to propagate. A streamer can supply these electrons by itself through photo-ionization, or the electrons can be present due to external background ionization. Here we investigate the effects of background ionization on streamer propagation and morphology by changing the gas composition and the repetition rate of the voltage pulses, and by adding a small amount of radioactive Krypton 85. We find that the general morphology of a positive streamer discharge in high purity nitrogen depends on background ionization: at lower background ionization levels the streamers branch more and have a more feather-like appearance. This is observed both when varying the repetition rate and when adding Krypton 85, though side branches are longer with the radioactive admixture. But velocities and minimal diameters of streamers are virtually independent of the background ionization level. In air, the inception cloud breaks up into streamers at a smaller radius when the repetition rate and therefore the background ionization level is higher. When measuring the effects of the pulse repetition rate and of the radioactive admixture on the discharge morphology, we found that our estimates of background ionization levels are consistent with these observations; this gives confidence in the estimates. Streamer channels generally do not follow the paths of previous discharge channels for repetition rates of up to 10 Hz. We estimate the effect of recombination and diffusion of ions and free electrons from the previous discharge and conclude that the old trail has largely disappeared at the moment of the next voltage pulse; therefore the next streamers indeed cannot follow the old trail.Comment: 30 pages, 13 figure

    Self-management practices of smokers with asthma and/or chronic obstructive pulmonary disease: a cross-sectional survey

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    Background Adherence to self-management recommendations is critical for patients with chronic disease. Compared to nonsmokers, smokers with conditions such as diabetes, HIV, and heart disease are less likely to adhere to provider recommendations. Regarding lung disease, asthma and COPD can be caused and/or exacerbated by smoking, however little is known on the relationship between adherence and smoking status in these patients. The purpose of this study was to characterize the relationship between smoking status and adherence to multiple measures of self-care- including medication taking, medication filling, appointment keeping, yearly vaccinations, carrying medical supplies, and healthcare utilization- in patients with asthma and/or COPD. In addition to smoking status, we also included an examination of these measures by race/ethnicity, gender, and diagnosis. Methods This study employed a cross-sectional design on a convenience sample of n = 84 patients (40–64 years old) with a diagnosis of asthma and/or COPD. The study was conducted between November 2015 and February 2016 in the waiting rooms of the outpatient pulmonary clinics at the University Medical Center of New Orleans. Patients completed surveys while awaiting their clinic appointments. Smoking status, gender, race, and diagnosis were explored as predictors of adherence using descriptive statistics, chi square, and regression analyses. Results Compared to nonsmokers, smokers were less adherent to medication filling (p < 0.0001), medication taking (p = 0.04), and having yearly vaccinations than nonsmokers (p = 0.003). Independent of smoking status, differences across self-care measures were also found based on respondent diagnosis, race, and gender. Conclusion Smoking was associated with lower levels of adherence across multiple measures of self-care. By identifying self-management practices that are most difficult for smokers to follow, researchers can develop interventions that target these behaviors. Future studies should further this research by exploring reasons for poor adherence in smokers as well as address barriers that inhibit self-care

    Density of Healthcare Providers and Patient Outcomes: Evidence from a Nationally Representative Multi-Site HIV Treatment Program in Uganda

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    This study examined the association between density of healthcare providers and patient outcomes using a large nationally representative cohort of patients receiving combination antiretroviral therapy (cART) in Uganda.Objective: We examined the association between density of healthcare providers and patient outcomes using a large nationally representative cohort of patients receiving combination antiretroviral therapy (cART) in Uganda. Design: We obtained data from The AIDS Support Organization (TASO) in Uganda. Patients 18 years of age and older who initiated cART at TASO between 2004 and 2008 contributed to this analysis. The number of healthcare providers per 100 patients, the number of patients lost to follow-up per 100 person years and number of deaths per 100 person years were calculated. Spearman correlation was used to identify associations between patient loss to follow-up and mortality with the healthcare provider-patient ratios. Results: We found no significant associations between the number of patients lost to follow-up and physicians (p = 0.45), nurses (p = 0.93), clinical officers (p = 0.80), field officers (p = 0.56), and healthcare providers overall (p = 0.83). Similarly, no significant associations were observed between mortality and physicians (p = 0.65), nurses (p = 0.49), clinical officers (p = 0.73), field officers (p = 0.78), and healthcare providers overall (p = 0.73). Conclusions: Patient outcomes, as measured by loss to follow-up and mortality, were not significantly associated with the number of doctors, nurses, clinical officers, field officers, or healthcare providers overall. This may suggest that that other factors, such as the presence of volunteer patient supporters or broader political or socioeconomic influences, may be more closely associated with outcomes of care among patients on cART in Uganda
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