866 research outputs found
Competing valence bond and symmetry breaking Mott states of spin-3/2 fermions on a honeycomb lattice
We investigate magnetic properties of strongly interacting four component
spin-3/2 ultracold fermionic atoms in the Mott insulator limit with one
particle per site in an optical lattice with honeycomb symmetry. In this limit,
atomic tunneling is virtual, and only the atomic spins can exchange. We find a
competition between symmetry breaking and liquid like disordered phases.
Particularly interesting are valence bond states with bond centered
magnetizations, situated between the ferromagnetic and conventional valence
bond phases. In the framework of a mean-field theory, we calculate the phase
diagram and identify an experimentally relevant parameter region where a
homogeneous SU(4) symmetric Affleck-Kennedy-Lieb-Tasaki-like valence bond state
is present
Persistent low adherence to hypertension treatment in Kyrgyzstan: How can we understand the role of drug affordability?
It is well known that cardiovascular diseases (CVD) are a growing cause of mortality and morbidity in low-and middle-income countries (LMIC). While hypertension (HTN), a leading risk factor for CVD, can be easily managed with widely available medicines, there is a huge gap in treatment for HTN in many LMIC. One such country is Kyrgyzstan, where HTN is a major public health concern and adherence to medication is low. The reasons for low adherence in Kyrgyzstan are not well understood, but some evidence suggests that HTN medicines may be unaffordable for low-income families, resulting in inequitable access to HTN treatment. With data from the 2010 Kyrgyzstan Integrated Household Survey, we estimate the prevalence and factors associated with adherence to HTN medication in Kyrgyzstan. We then investigate the hypothesis that affordability may be an important factor in adherence to HTN medication. Using the coarsened exact matching approach, we estimate the economic burden faced by households with at least one member with elevated blood pressure (EBP) in Kyrgyzstan and their risk of catastrophic spending on health care. We find that EBP households have significantly higher total expenditure on health, as well as on medicines, and are more likely to experience catastrophic health spending, suggesting that out-of-pocket expenditure for EBP may be prohibitively expensive for the poorest in Kyrgyzstan. Our findings also reveal a high prevalence of self-medication (i.e. purchasing and using medication without a doctor's prescription), and increased expenditure due to self-medication, among those with EBP. Our research suggests that affordability of HTN medicines may be an important factor in low adherence to treatment in Kyrgyzstan. Low affordability may be due partly to the prescription of medicines that are not reimbursable under the national drug benefit plan, but more research is needed to identify solutions to the affordability problem
The effects of ozone on immune function.
A review of the literature reveals that ozone (O3) exposure can either suppress or enhance immune responsiveness. These disparate effects elicited by O3 exposure depend, in large part, on the experimental design used, the immune parameters examined as well as the animal species studied. Despite the apparent contradictions, a general pattern of response to O3 exposure can be recognized. Most studies indicate that continuous O3 exposure leads to an early (days 0-3) impairment of immune responsiveness followed, with continued exposures, by a form of adaptation to O3 that results in a re-establishment of the immune response. The effects of O3 exposure on the response to antigenic stimulation also depend on the time at which O3 exposure occurred. Whereas O3 exposure prior to immunization is without effect on the response to antigen, O3 exposure subsequent to immunization suppresses the response to antigen. Although most studies have focused on immune responses in the lung, numerous investigators have provided functional and anatomical evidence to support the hypothesis that O3 exposure can have profound effects on systemic immunity
Seeds Buffering for Information Spreading Processes
Seeding strategies for influence maximization in social networks have been
studied for more than a decade. They have mainly relied on the activation of
all resources (seeds) simultaneously in the beginning; yet, it has been shown
that sequential seeding strategies are commonly better. This research focuses
on studying sequential seeding with buffering, which is an extension to basic
sequential seeding concept. The proposed method avoids choosing nodes that will
be activated through the natural diffusion process, which is leading to better
use of the budget for activating seed nodes in the social influence process.
This approach was compared with sequential seeding without buffering and single
stage seeding. The results on both real and artificial social networks confirm
that the buffer-based consecutive seeding is a good trade-off between the final
coverage and the time to reach it. It performs significantly better than its
rivals for a fixed budget. The gain is obtained by dynamic rankings and the
ability to detect network areas with nodes that are not yet activated and have
high potential of activating their neighbours.Comment: Jankowski, J., Br\'odka, P., Michalski, R., & Kazienko, P. (2017,
September). Seeds Buffering for Information Spreading Processes. In
International Conference on Social Informatics (pp. 628-641). Springe
Fast pyrolysis of halogenated plastics recovered from waste computers
The disposal of waste computers is an issue that is gaining increasing interest around the world. In this paper, results from the fast pyrolysis in a fluidized bed reactor of three different waste computer monitor casings composed of mainly acrylonitrile-butadiene-styrene (ABS) copolymer and two different waste computer body casings composed of mostly poly(vinyl chloride) (PVC) type polymers are presented. Preliminary characterization of the waste plastics was investigated using coupled thermogravimetric analysis-Fourier transform infrared spectrometry (TGA-FT-IR). The results showed that the plastics decomposed in two stages. For the ABS-containing monitor casings, aromatic and aliphatic material were released in the first and second stages. The PVC-containing computer body casing samples showed a first-stage evolution of HCl and a second stage evolution of aromatic and aliphatic material and further HCl. In addition, each of the five plastics was fast-pyrolyzed in a laboratory-scale fluidized bed reactor at 500 °C. The fluidized bed pyrolysis led to the conversion of most of the plastics to pyrolysis oil, although the two PVC computer body cases produced large quantities of HCl. The pyrolysis oils were characterized by GC-MS and it was found that they were chemically very heterogeneous and contained a wide range of aliphatic, aromatic, halogenated, oxygenated, and nitrogenated compounds
A new version of the HBSC Family Affluence Scale - FAS III: Scottish qualitative findings from the International FAS Development Study
A critical review of the Family Affluence Scale (FAS) concluded that FAS II was no longer discriminatory within very rich or very poor countries, where a very high or a very low proportion of children were categorised as high FAS or low FAS respectively (Currie et al. 2008). The review concluded that a new version of FAS - FAS III - should be developed to take into account current trends in family consumption patterns across the European region, the US and Canada. In 2012, the FAS Development and Validation Study was conducted in eight countries - Denmark, Greenland, Italy, Norway, Poland, Romania, Slovakia and Scotland. This paper describes the Scottish qualitative findings from this study. The Scottish qualitative fieldwork comprising cognitive interviews and focus groups sampled from 11, 13 and 15 year-old participants from 18 of the most- and least- economically deprived schools. These qualitative results were used to inform the final FAS III recommendations.Publisher PDFPeer reviewe
Thermogravimetric and reaction kinetic analysis of biomass samples from an energy plantation
The products of a Hungarian experimental plantation for energy crops were investigated. Young shoots of poplar clones (Populus x euramericana and Populus x interamericana), black locust (Robinia pseudoacacia), willow (Salix alba), and an herbaceous plant (Miscanthus sinensis) revealed unexpectedly similar thermal behavior in inert and oxidative atmospheres, as well. An 8-fold difference in the level of grinding did not result in substantial differences in the thermal decomposition. The effect of oxygen in the ambient gas was studied at low sample masses (0.2-0.4 mg) that excluded the overheating due to the high reaction heat of the combustion process. The presence of oxygen affects the decomposition from ca. 220 degreesC. Nevertheless, the extrapolated onset temperature of the hemicellulose decomposition is practically the same at 0, 5, and 21 V/V% oxygen. A group of 12 experiments, representing two grinding levels, three plant genera and four different heating programs were evaluated simultaneously by the method of least squares employing the model of independent pseudocomponents. All evaluated experiments were well described by the same set of kinetic parameters; only the parameters describing the peak area of the partial processes differed. A technique was recommended for the appropriate handling of the nonrandom errors in the simultaneous evaluation of experiment series
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