bluuebunny/crossref_metadata_2025_split huggingface dataset:
Communication between HIV‐infected children and their caregivers about HIV medicines: a cross‐sectional study in Jinja district, Uganda
Authors: Kajubi Phoebe , Whyte Susan , Muhumuza Simon , Kyaddondo David , Katahoire Anne R 
Published: July 2014

IntroductionKnowledge of antiretroviral therapy (ART) among children with HIV depends on open communication with them about their health and medicines. Guidelines assign responsibility for communication to children's home caregivers. Other research suggests that communication is poor and knowledge about ART is low among children on treatment in low‐income countries. This study sought to describe communication about medicine for HIV in quantitative terms from the perspectives of both children and caregivers. Thereafter, it established the factors associated with this communication and with children's knowledge about their HIV medicines.MethodsWe undertook a cross‐sectional survey of a random sample of 394 children with HIV on treatment and their caregivers at nine health facilities in Jinja District, Uganda. We assessed reported frequency and content of communication regarding their medicines as well as knowledge of what the medicines were for. Logistic regression analysis was used to determine the factors associated with communication patterns and children's knowledge of HIV medicines.ResultsAlthough 79.6% of the caregivers reported that they explained to the children about the medicines, only half (50.8%) of the children said they knew that they were taking medicines for HIV. Older children aged 15–17 years were less likely to communicate with a caregiver about the HIV medicines in the preceding month (OR 0.5, 95% CI 0.3–0.7, p=0.002). Children aged 11–14 years (OR 6.1, 95% CI 2.8–13.7, p<0.001) and 15–17 years (OR 12.6, 95% CI 4.6–34.3, p<0.001) were more likely to know they were taking medicines for HIV compared to the younger ones. The least common reported topic of discussion between children and caregivers was “what the medicines are for” while “the time to take medicines” was by far the most mentioned by children.ConclusionsCommunication about, and knowledge of, HIV medicines among children with HIV is low. Young age (less than 15 years) was associated with more frequent communication. Caregivers should be supported to communicate diagnosis and treatment to children with HIV. Age‐sensitive guidelines about the nature and content of communication should be developed.
Mechanistic models of biofilm growth in porous media
Authors: Jaiswal Priyank , Al‐Hadrami Fathiya , Atekwana Estella A. , Atekwana Eliot A. 
Published: July 2014

AbstractNondestructive acoustics methods can be used to monitor in situ biofilm growth in porous media. In practice, however, acoustic methods remain underutilized due to the lack of models that can translate acoustic data into rock properties in the context of biofilm. In this paper we present mechanistic models of biofilm growth in porous media. The models are used to quantitatively interpret arrival times and amplitudes recorded in the 29 day long Davis et al. (2010) physical scale biostimulation experiment in terms of biofilm morphologies and saturation. The model pivots on addressing the sediment elastic behavior using the lower Hashin‐Shtrikman bounds for grain mixing and Gassmann substitution for fluid saturation. The time‐lapse P wave velocity (VP; a function of arrival times) is explained by a combination of two rock models (morphologies); “load bearing” which assumes the biofilm as an additional mineral in the rock matrix and “pore filling” which assumes the biofilm as an additional fluid phase in the pores. The time‐lapse attenuation (QP−1; a function of amplitudes), on the other hand, can be explained adequately in two ways; first, through squirt flow where energy is lost from relative motion between rock matrix and pore fluid, and second, through an empirical function of porosity (φ), permeability (κ), and grain size. The squirt flow model‐fitting results in higher internal φ (7% versus 5%) and more oblate pores (0.33 versus 0.67 aspect ratio) for the load‐bearing morphology versus the pore‐filling morphology. The empirical model‐fitting results in up to 10% increase in κ at the initial stages of the load‐bearing morphology. The two morphologies which exhibit distinct mechanical and hydraulic behavior could be a function of pore throat size. The biofilm mechanistic models developed in this study can be used for the interpretation of seismic data critical for the evaluation of biobarriers in bioremediation, microbial enhanced oil recovery, and CO2 sequestration.
A two‐leaf rectangular hyperbolic model for estimating GPP across vegetation types and climate conditions
Authors: Wang Fumin , Chen Jing M. , Gonsamo Alemu , Zhou Bin , Cao Feifeng , Yi Qiuxiang 
Published: July 2014

AbstractThere are mainly three types of gross primary production (GPP), including light use efficiency (LUE) model, rectangular hyperbolic model (RHM), and process‐based model (PBM). RHM is not widely used because its parameters, namely, quantum yield (α) and maximum photosynthetic rate (Pm), vary temporally with temperature and spatially with vegetation type under natural conditions. In the study, we present a temperature‐ and vegetation‐type‐adapted RHM by linking it to the Baldocchi's model to obtain the relationship between α‐Pm and Vcmax,25‐temperature to overcome the shortcomings of traditional RHM. The modified RHM (MRHM) coupled with a two‐leaf upscaling strategy makes it possible to accurate and fast estimation of GPP at large scale. Twenty‐two CO2 eddy‐covariance sites with different vegetation types, including evergreen needleleaf forest, deciduous broadleaf forest, grassland, and evergreen broadleaf forest, are used to evaluate the performance of MRHM for GPP estimation. The comparisons of the simulated GPP using MRHM with measured and Boreal Ecosystem Productivity Simulator‐simulated GPP demonstrate that the MRHM can simulate GPP as accurately as PBM and in the meantime with the advantage of simplicity as LUE model. These results show the promising potential of MRHM for accurately simulating GPP with relative high computational efficiency, providing an ideal alternative tool for large‐scale and long time series GPP simulations.
Soil moisture and soil properties estimation in the Community Land Model with synthetic brightness temperature observations
Authors: Han Xujun , Franssen Harrie‐Jan Hendricks , Montzka Carsten , Vereecken Harry 
Published: July 2014

AbstractThe Community Land Model (CLM) includes a large variety of parameterizations, also for flow in the unsaturated zone and soil properties. Soil properties introduce uncertainties into land surface model predictions. In this paper, soil moisture and soil properties are updated for the coupled CLM and Community Microwave Emission Model (CMEM) by the Local Ensemble Transform Kalman Filter (LETKF) and the state augmentation method. Soil properties are estimated through the update of soil textural properties and soil organic matter density. These variables are used in CLM for predicting the soil moisture retention characteristic and the unsaturated hydraulic conductivity, and the soil texture is used in CMEM to calculate the soil dielectric constant. The following scenarios were evaluated for the joint state and parameter estimation with help of synthetic L‐band brightness temperature data assimilation: (i) the impact of joint state and parameter estimation; (ii) updating of soil properties in CLM alone, CMEM alone or both CLM and CMEM; (iii) updating of soil properties without soil moisture update; (iv) the observation localization of LETKF. The results show that the characterization of soil properties through the update of textural properties and soil organic matter density can strongly improve with assimilation of brightness temperature data. The optimized soil properties also improve the characterization of soil moisture, soil temperature, actual evapotranspiration, sensible heat flux, and soil heat flux. The best results are obtained if the soil properties are updated only. The coupled CLM and CMEM model is helpful for the parameter estimation. If soil properties are biased, assimilation of soil moisture data with only state updates increases the root mean square error for evapotranspiration, sensible heat flux, and soil heat flux.
Grain‐size sensitive rheology of orthopyroxene
Authors: Bruijn Rolf H.C. , Skemer Philip 
Published: July 2014

AbstractThe grain‐size sensitive rheology of orthopyroxene is investigated using data from rheological and microstructural studies. A deformation mechanism map is constructed assuming that orthopyroxene deforms by two independent mechanisms: dislocation creep and diffusion creep. The field boundary between these mechanisms is defined using two approaches. First, experimental data from Lawlis (1998), which show a deviation from non‐linear power law behavior at low stresses, are used to prescribe the location of the field boundary. Second, a new orthopyroxene grain‐size piezometer is used as a microstructural constraint to the field boundary. At constant temperature, both approaches yield sub‐parallel field boundaries, separated in grain size by a factor of only 2–5. Extrapolating to lithospheric conditions, the deformation mechanism transition occurs at a grain size of ~150–500 µm, consistent with observations from nature. As the transition from dislocation to diffusion creep may promote shear localization, grain‐size reduction of orthopyroxene may play a prominent role in plate‐boundary deformation.
Stationary points in activation energy for heat dissipated with a power law temperature‐dependent viscoelastoplastic rheology
Authors: So B.‐D. , Yuen D. A. 
Published: July 2014

AbstractWe report that there exist a local maximum and minimum in the activation energy Ea describing mechanical heat dissipation of olivine for a given initial temperature and amount of deformation. The stationary point for the minimum dissipation is ~200 kJ/mol lower than that for the maximum. For larger activation energy than the stationary point for maximum dissipation, plastic deformation is sharply weakened and the temperature rise disappears altogether. Higher values of the initial temperature produce a larger local maximum for activation energy. The amount of heat dissipation increases with Ea in a nonlinear manner. Our results have direct ramifications on shear zone, which is governed by the amount of mechanical heat dissipation. We have observed them over a wide range of temperature and deformation boundary conditions. Our two‐dimensional model study can provide valuable insight to enable greater predictive capability for the development of geodynamic shear zone in planetary‐scale plate tectonics.
Climate change and probabilistic scenario of streamflow extremes in an alpine region
Authors: Yang Tao , Wang Xiaoyan , Yu Zhongbo , Krysanova Valentina , Chen Xi , Schwartz Franklin W. , Sudicky Edward A. 
Published: July 2014

AbstractFuture projections of streamflow extremes are of paramount significance in assessing the climate impacts on social and natural systems, particularly for the Himalayan alpine region in the Tibetan Plateau known as the Asian water tower. This study strives to quantify the uncertainties from different sources in simulating future extreme flows and seeks to construct reliable scenarios of future extreme flows for the headwater catchment of the Yellow River Basin in the 21st century. The results can be formulated as follows: (1) The revised snow model based on a daily active temperature method is superior to the commonly used degree‐day method in simulating snowmelt processes. (2) In general, hydrological models contribute more uncertainties than the downscaling methods in high flow and low flow over the cryospheric alpine regions characterized by the snow‐rainfall‐induced runoff processes under most scenarios. Meanwhile, impacts to uncertainty vary with time. (3) The ultimate probability of high flow exhibits a downward trend in future by using an unconditional method, whereas positive changes in the probability of low flow are projected. The method in the work includes a variety of influence from different contributing factors (e.g., downscaling models, hydrological models, model parameters, and their simulation skills) on streamflow projection, therefore can offer more information (i.e., different percentiles of flow and uncertainty ranges) for future water resource planning compared with the purely deterministic approaches. Hence, the results are beneficial to boost our current methodologies of climate impact research in the Himalayan alpine zone.
Sildenafil does not improve cardiomyopathy in Duchenne/Becker muscular dystrophy
Authors: Leung Doris G. , Herzka Daniel A. , Thompson W. Reid , He Bing , Bibat Genila , Tennekoon Gihan , Russell Stuart D. , Schuleri Karl H. , Lardo Albert C. , Kass David A. , Thompson Richard E. , Judge Daniel P. , Wagner Kathryn R. 
Published: July 2014

ObjectiveDuchenne and Becker muscular dystrophies (DBMD) are allelic disorders caused by mutations in dystrophin. Adults with DBMD develop life‐threatening cardiomyopathy. Inhibition of phosphodiesterase 5 (PDE5) improves cardiac function in mouse models of DBMD. To determine whether the PDE5‐inhibitor sildenafil benefits human dystrophinopathy, we conducted a randomized, double‐blind, placebo‐controlled trial (ClinicalTrials.gov, number NCT01168908).MethodsAdults with DBMD and cardiomyopathy (ejection fraction ≤ 50%) were randomized to receive sildenafil (20mg 3× daily) or placebo for 6 months. All subjects received an additional 6 months of open‐label sildenafil. The primary endpoint was change in left ventricular end‐systolic volume (LVESV) on cardiac magnetic resonance imaging. Secondary cardiac endpoints, skeletal muscle function, and quality of life were also assessed.ResultsAn interim analysis (performed after 15 subjects completed the blinded phase) revealed that 29% (4 of 14) of subjects had a ≥10% increase in LVESV after 6 months of sildenafil compared to 13% (1 of 8) of subjects receiving placebo. Subjects with LVESV > 120ml at baseline were more likely to worsen at 12 months regardless of treatment assignment (p = 0.035). Due to the higher number of subjects worsening on sildenafil, the data and safety monitoring board recommended early termination of the study. There were no statistically significant differences in outcome measures between treatment arms.InterpretationDue to the small sample size, comparisons between groups must be interpreted with caution. However, this trial suggests that sildenafil is unlikely to improve cardiac function in adults with DBMD. Ann Neurol 2014;76:541–549
Enantioselective Biomimetic Total Syntheses of Kuwanons I and J and Brosimones A and B
Authors: Han Jianguang , Li Xia , Guan Yong , Zhao Wenjun , Wulff William D. , Lei Xiaoguang 
Published: July 2014

AbstractThe first enantioselective total syntheses of prenylflavonoid Diels–Alder natural products (−)‐kuwanon I, (+)‐kuwanon J, (−)‐brosimone A, and (−)‐brosimone B have been accomplished from a common intermediate based on a concise synthetic strategy. Key elements of the synthesis include a biosynthesis‐inspired asymmetric Diels–Alder cycloaddition mediated by a chiral ligand/boron Lewis acid, as well as a process involving regioselective Schenck ene reaction, reduction, and dehydration to realize a biomimetic dehydrogenation for generation of the required diene precursor. Furthermore, a remarkable tandem inter‐/intramolecular asymmetric Diels–Alder cycloaddition process was applied for the synthesis of (−)‐brosimone A.
Zirconium Allyl Complexes as Participants in Zirconocene‐Catalyzed α‐Olefin Polymerizations
Authors: Babushkin Dmitrii E. , Panchenko Valentina N. , Brintzinger Hans‐Herbert 
Published: July 2014

AbstractIn a search for the hitherto elusive catalyst resting state(s) of zirconocene‐based olefin polymerization catalysts, a combination of UV/Vis and NMR spectrometric methods reveals that polymer‐carrying cationic Zr allyl complexes make up about 90 % of the total catalyst concentration. Other catalyst species that take part in the polymerization process have to be generated from this allyl pool into which they appear to relapse rather frequently.
Dielectric and thermal studies of segmental dynamics in silica/PDMS and silica/titania/PDMS nanocomposites
Authors: Sulym Iryna , Klonos Panagiotis , Borysenko Mykola , Pissis Polycarpos , Gun'ko Vladimir M. 
Published: July 2014

ABSTRACTEffects of silica and silica/titania nanoparticles on glass transition and segmental dynamics of poly(dimethylsiloxane) (PDMS) were studied for composites of a core–shell type using differential scanning calorimetry, thermally stimulated depolarization current, and dielectric relaxation spectroscopy techniques. Strong interactions between the filler and the polymer suppress crystallinity (Tc, Xc) and affect significantly the evolution of the glass transition in the nanocomposites. The segmental relaxation associated with the glass transition consists of three contributions, arising, in the order of decreasing mobility, from the bulk (unaffected) amorphous polymer fraction (α relaxation), from polymer chains restricted between condensed crystal regions (αc relaxation), and from the semi‐bound polymers in an interfacial layer with strongly reduced mobility due to interactions with surface hydroxyls of silica and silica/titania nanoparticles (α′ relaxation). The evolution of surface affected CH3 groups, as well as the degree of interaction of PDMS molecules with surface hydroxyl groups as a function of treatment temperature, was assessed by Fourier transform infrared spectroscopy, thermogravimetry and differential thermal analysis. The effectiveness of silica/PDMS and silica/titania/PDMS nanocomposites as hydrophobic coatings was investigated by static contact angle measurements. It was shown that the presence of titania nanoparticles and adsorbed PDMS promotes the hydrophobic properties of the PDMS coating after treatment in the 80–650°C range. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41154.
Regulation of Early Cartilage Destruction in Inflammatory Arthritis by Death Receptor 3
Authors: Wang Eddie C. Y. , Newton Zarabeth , Hayward Olivia A. , Clark Stephen R. , Collins Fraser , Perks William V. , Singh Ravinder K. , Twohig Jason P. , Williams Anwen S. 
Published: July 2014

ObjectiveTo investigate the role of death receptor 3 (DR‐3) and its ligand tumor necrosis factor–like molecule 1A (TL1A) in the early stages of inflammatory arthritis.MethodsAntigen‐induced arthritis (AIA) was generated in C57BL/6 mice deficient in the DR‐3 gene (DR3−/−) and their DR3+/+ (wild‐type) littermates by priming and intraarticular injection of methylated bovine serum albumin. The joints were sectioned and analyzed histochemically for damage to cartilage and expression of DR3, TL1A, Ly‐6G (a marker for neutrophils), the gelatinase matrix metalloproteinase 9 (MMP‐9), the aggrecanase ADAMTS‐5, and the neutrophil chemoattractant CXCL1. In vitro production of MMP‐9 was measured in cultures from fibroblasts, macrophages, and neutrophils following the addition of TL1A and other proinflammatory stimuli.ResultsDR3 expression was up‐regulated in the joints of wild‐type mice following generation of AIA. DR3−/− mice were protected against cartilage damage compared with wild‐type mice, even at early time points prior to the main accumulation of Teff cells in the joint. Early protection against AIA in vivo correlated with reduced levels of MMP‐9. In vitro, neutrophils were major producers of MMP‐9, while neutrophil numbers were reduced in the joints of DR3−/− mice. However, TL1A neither induced MMP‐9 release nor affected the survival of neutrophils. Instead, reduced levels of CXCL1 were observed in the joints of DR3−/− mice.ConclusionDR‐3 drives early cartilage destruction in the AIA model of inflammatory arthritis through the release of CXCL1, maximizing neutrophil recruitment to the joint and leading to enhanced local production of cartilage‐destroying enzymes.
Current and future trends in food waste valorization for the production of chemicals, materials and fuels: a global perspective
Authors: Lin Carol Sze Ki , Koutinas Apostolis A. , Stamatelatou Katerina , Mubofu Egid B. , Matharu Avtar S. , Kopsahelis Nikolaos , Pfaltzgraff Lucie A. , Clark James H. , Papanikolaou Seraphim , Kwan Tsz Him , Luque Rafael 
Published: July 2014

AbstractFood waste is currently generated in significant quantities worldwide. While most of this has generally few uses different from landfilling or composting, advanced valorization alternatives should be developed to maximize the value derived from such an important waste source. This contribution aims to illustrate a series of examples and current valorization strategies proposed in different countries in order to tackle the food waste issue. Proposed processing schemes involve biorefinery approaches based on both chemical and biological technologies. Important legislation aspects in different countries are also presented. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd
Comparing translational population‐PBPK modelling of brain microdialysis with bottom‐up prediction of brain‐to‐plasma distribution in rat and human
Authors: Ball Kathryn , Bouzom François , Scherrmann Jean‐Michel , Walther Bernard , Declèves Xavier 
Published: July 2014

ABSTRACTThe prediction of brain extracellular fluid (ECF) concentrations in human is a potentially valuable asset during drug development as it can provide the pharmacokinetic input for pharmacokinetic–pharmacodynamic models. This study aimed to compare two translational modelling approaches that can be applied at the preclinical stage of development in order to simulate human brain ECF concentrations. A population‐PBPK model of the central nervous system was developed based on brain microdialysis data, and the model parameters were translated to their corresponding human values to simulate ECF and brain tissue concentration profiles. In parallel, the PBPK modelling software Simcyp was used to simulate human brain tissue concentrations, via the bottom‐up prediction of brain tissue distribution using two different sets of mechanistic tissue composition‐based equations. The population‐PBPK and bottom‐up approaches gave similar predictions of total brain concentrations in both rat and human, while only the population‐PBPK model was capable of accurately simulating the rat ECF concentrations. The choice of PBPK model must therefore depend on the purpose of the modelling exercise, the in vitro and in vivo data available and knowledge of the mechanisms governing the membrane permeability and distribution of the drug. Copyright © 2014 John Wiley & Sons, Ltd.