A transition from low-input subsistence farming in Sub-Saharan Africa will require the use of yield-increasing agricultural technologies. However, in developing countries, most farmers continue to rely heavily on pest-infested and disease-infected recycled seed from own or local sources leading to low yields. This study used a field experiment to examine the effect of a social incentive combined with goal setting on the diffusion of agricultural knowledge and uptake of quality certified seed by farmers.
View Article and Find Full Text PDFSolving grand environmental societal challenges calls for transdisciplinary and participatory methods in social-ecological research. These methods enable co-designing the research, co-producing the results, and co-creating the impacts together with concerned stakeholders. COVID-19 has had serious impacts on the choice of research methods, but reflections on recent experiences of "moving online" are still rare.
View Article and Find Full Text PDFContext: Resilience is the ability to deal with shocks and stresses, including the unknown and previously unimaginable, such as the Covid-19 crisis.
Objective: This paper assesses (i) how different farming systems were exposed to the crisis, (ii) which resilience capacities were revealed and (iii) how resilience was enabled or constrained by the farming systems' social and institutional environment.
Methods: The 11 farming systems included have been analysed since 2017.
This study investigated the impact of cooking fuel choice on the health of elderly people, as measured by activities of daily living, using micro survey data from the China Health and Retirement Longitudinal Study 2015. In contrast to previous studies, our focus on activities of daily living allows for a more comprehensive analysis of health outcomes than diagnoses or doctor visits. Propensity score matching and an endogenous switching regression model were used to address potential selection biases.
View Article and Find Full Text PDFGlobal efforts for biodiversity protection and land use-based greenhouse gas mitigation call for increases in the effectiveness and efficiency of environmental conservation. Incentive-based policy instruments are key tools for meeting these goals, yet their effectiveness might be undermined by such factors as social norms regarding whether payments are considered fair. We investigated the causal link between equity and conservation effort with a randomized real-effort experiment in forest conservation with 443 land users near a tropical forest national park in the Vietnamese Central Annamites, a global biodiversity hotspot.
View Article and Find Full Text PDFThe instanton method obtains approximate tunneling rates from the minimum-action path (known as the instanton) linking reactants to the products at a given temperature. An efficient way to find the instanton is to search for saddle-points on the ring-polymer potential surface, which is obtained by expressing the quantum Boltzmann operator as a discrete path-integral. Here we report a practical implementation of this ring-polymer form of instanton theory into the Molpro electronic-structure package, which allows the rates to be computed on-the-fly, without the need for a fitted analytic potential-energy surface.
View Article and Find Full Text PDFCatheter Cardiovasc Interv
September 2018
Severe pulmonary regurgitation (PR) most commonly occurs as a sequelae of treatment of pulmonic stenosis or Tetralogy of Fallot with fewer cases of primary pulmonic valvular regurgitation. The amount of PR is influenced by valvular integrity, right ventricular (RV) size, and RV diastolic pressures. In chronic severe PR, the RV remodels to accommodate the regurgitant flow and RV stroke volume increases to maintain effective forward blood flow.
View Article and Find Full Text PDFPhys Chem Chem Phys
November 2014
We obtain a shallow-tunnelling correction factor for use with Wigner-Eyring transition-state theory (TST). Our starting point is quantum transition state theory (QTST), which approximates the accurate quantum rate as the instantaneous flux through a delocalised transition-state ensemble of ring-polymers. Expanding the ring-polymer potential to second order gives the well-known Wigner tunnelling-factor which diverges at the cross-over temperature between deep and shallow tunnelling.
View Article and Find Full Text PDFLeft ventricular assist devices (LVADs) are an increasingly common treatment for end-stage systolic heart failure. However, there are limited data on how to best treat patients pharmacologically after LVAD implantation, resulting in uncertainty about which heart failure medications provide the most benefit. Still, some evidence exists that certain medical therapies can prevent remodeling and improve right ventricular and, possibly, left ventricular function.
View Article and Find Full Text PDFPeptidylglycine α-hydroxylating monooxygenase is a noninteracting bicopper enzyme that stereospecifically hydroxylates the terminal glycine of small peptides for its later amidation. Neuroendocrine messengers, such as oxytocin, rely on the biological activity of this enzyme. Each catalytic turnover requires one oxygen molecule, two protons from the solvent, and two electrons.
View Article and Find Full Text PDFHeart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome based on traditional heart failure symptoms with documentation of increased left ventricular filling pressures and preserved left ventricular ejection fraction. The exact mechanisms that induce HFpEF are not known. End-diastolic ventricular stiffness does not seem to be acting alone.
View Article and Find Full Text PDFAtherosclerosis development is a complex process, with inflammation, indicated by elevated high-sensitivity C-reactive protein (hs-CRP), as a potential mediator. Obesity, physical activity, and depression have all been reported to affect hs-CRP. However, these factors are interconnected, and their relative individual importance remains unclear.
View Article and Find Full Text PDFThe role of quantum mechanical atom tunneling during the conversion of glutamate to methylaspartate catalyzed by glutamate mutase is investigated by quantum mechanical/molecular mechanical (QM/MM) simulations based on coupled cluster and density functional calculations. The use of instanton theory allows us to calculate the tunneling contributions of up to 78 atoms in the active site. We calculate kinetic isotope effects (KIEs) and compare them to experimental data.
View Article and Find Full Text PDFThe ring-opening reaction of the cyclopropylcarbinyl radical proceeds via heavy-atom tunneling at low temperature. We used instanton theory to calculate tunneling rates and kinetic isotope effects with on-the-fly calculation of energies by density functional theory (B3LYP). The accuracy was verified by explicitly correlated coupled-cluster calculations (UCCSD(T)-F12).
View Article and Find Full Text PDFThe radical mechanism of the conversion of glutamate to methylaspartate catalyzed by glutamate mutase is studied with quantum mechanical/molecular mechanical (QM/MM) simulations based on density functional theory (DFT/MM). The hydrogen transfer between the substrate and the cofactor is found to be rate limiting with a barrier of 101.1 kJ mol(-1).
View Article and Find Full Text PDFThe instanton method allows to accurately calculate tunneling rates down to very low temperature. However, with lowering the temperature, the computational effort steeply increases as many more discretization points are required. This is caused in practical applications by the majority of the discretization points accumulating at a very small region in configuration space.
View Article and Find Full Text PDFWe implemented and compared four algorithms to locate instantons, i.e., the most likely tunneling paths at a given temperature.
View Article and Find Full Text PDFPurpose: Transcriptional profiling showed decreased expression of gastrokine 1 (GKN1) and the related trefoil factor interacting protein (TFIZ1/GKN2) in Helicobacter pylori infection. Decreased GKN1 and GKN2 mRNA expression has been reported in gastric adenocarcinoma. We have examined GKN1 and GKN2 protein expression in a large gastric cancer series, correlated expression with tumor subtype, and evaluated their utility as prognostic biomarkers.
View Article and Find Full Text PDFA retrospective review was conducted of 50 patients with bilateral Array multifocal intraocular lens implantation. The purpose was to assess their visual performance and adaptability to the visual world of multifocality. On binocular visual acuity examination all patients obtained, without any correction, Snellen 20/25 or more for distance and Snellen 20/40 (distant equivalent) or more for near.
View Article and Find Full Text PDFAnasthesiol Intensivmed Notfallmed Schmerzther
September 1999
This case report presents a 44-year-old woman with severe arterial ischemia leading to claudicatio and acute pain in rest caused by an ergotism. In the history was an abuse of suppositories containing caffeine and ergotamine induced by chronic headache. The initial angiography showed occlusions of the femoral arteries.
View Article and Find Full Text PDFPhys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics
October 1996