Evaluative Conditioning: Arti-fact or -fiction?—A Reply to Baeyens, De Houwer, Vansteenwegen, and Eelen (1998)

Baeyens et al.(1998) claim that Field and Davey's (1997) controversial study of conceptual conditioning offers little threat to current conceptions of evaluative conditioning. This article addresses some of the questions posed by Baeyenset al.First, some criticisms of the conceptual conditioning study appear to be based on a misunderstanding of the procedure. Second, we address the issues surrounding the so-called Type-X procedure. Specifically, we begin by reviewing the status of studies that have used a procedure different from the Type-X procedure. It is then argued that, although the Type-X procedure has been used in only a portion of EC research, it has been used primarily in those studies whose outcome has been used to argue that evaluative conditioning (EC) is functionally distinct from autonomic conditioning. We then review the evidence from non-Type-X procedures that EC is a distinct form of learning. Finally, an attempt is made to explain why between-subject controls should be used as a matter of course in this field of research

Do ACE inhibitors improve the response to exercise training in functionally impaired older adults? A randomized controlled trial

<br>Background: Loss of muscle mass and strength with ageing is a major cause for falls, disability, and morbidity in older people. Previous studies have found that angiotensin-converting enzyme inhibitors (ACEi) may improve physical function in older people. It is unclear whether ACEi provide additional benefit when added to a standard exercise training program. We examined the effects of ACEi therapy on physical function in older people undergoing exercise training.</br> <b>Methods:</b> Community-dwelling people aged ≥65 years with functional impairment were recruited through general (family) practices. All participants received progressive exercise training. Participants were randomized to receive either 4 mg perindopril or matching placebo daily for 20 weeks. The primary outcome was between-group change in 6-minute walk distance from baseline to 20 weeks. Secondary outcomes included changes in Short Physical Performance Battery, handgrip and quadriceps strength, self-reported quality of life using the EQ-5D, and functional impairment measured using the Functional Limitations Profile.<p></p> <b>Results:</b> A total of 170 participants (n = 86 perindopril, n = 84 placebo) were randomized. Mean age was 75.7 (standard deviation [SD] 6.8) years. Baseline 6-minute walk distance was 306 m (SD 99). Both groups increased their walk distance (by 29.6 m perindopril, 36.4 m placebo group) at 20 weeks, but there was no statistically significant treatment effect between groups (−8.6m [95% confidence interval: −30.1, 12.9], p = .43). No statistically significant treatment effects were observed between groups for the secondary outcomes. Adverse events leading to withdrawal were few (n = 0 perindopril, n = 4 placebo).<p></p> <b>Interpretation:</b> ACE inhibitors did not enhance the effect of exercise training on physical function in functionally impaired older people.<p></p&gt

Finite element modeling of the combined faradaic and electrostatic contributions to the voltammetric response of monolayer redox films

The voltammetric response of electrodes coated with a redox-active monolayer is computed by finite element simulations based on a generalized model that couples the Butler–Volmer, Nernst–Planck, and Poisson equations. This model represents the most complete treatment of the voltammetric response of a redox film to date and is made accessible to the experimentalist via the use of finite element modeling and a COMSOL-generated report. The model yields a full description of the electric potential and charge distributions across the monolayer and bulk solution, including the potential distribution associated with ohmic resistance. In this way, it is possible to properly account for electrostatic effects at the molecular film/electrolyte interface, which are present due to the changing charge states of the redox head groups as they undergo electron transfer, under both equilibrium and nonequilibrium conditions. Specifically, our numerical simulations significantly extend previous theoretical predictions by including the effects of finite electron-transfer rates (k0) and electrolyte conductivity. Distortion of the voltammetric wave due to ohmic potential drop is shown to be a function of electrolyte concentration and scan rate, in agreement with experimental observations. The commonly used Laviron analysis for the determination of k0 fails to account for ohmic drop effects, which may be non-negligible at high scan rates. This model provides a more accurate alternative for k0 determination at all scan rates. The electric potential and charge distributions across an electrochemically inactive monolayer and electrolyte solution are also simulated as a function of applied potential and are found to agree with the Gouy-Chapman-Stern theory

Simulation of the cyclic voltammetric response of an outer-sphere redox species with inclusion of electrical double layer structure and ohmic potential drop

A finite-element model has been developed to simulate the cyclic voltammetric (CV) response of a planar electrode for a 1e outer-sphere redox process, which fully accounts for cell electrostatics, including ohmic potential drop, ion migration, and the structure of the potential-dependent electric double layer. Both reversible and quasi-reversible redox reactions are treated. The simulations compute the time-dependent electric potential and ion distributions across the entire cell during a voltammetric scan. In this way, it is possible to obtain the interdependent faradaic and non-faradaic contributions to a CV and rigorously include all effects of the electric potential distribution on the rate of electron transfer and the local concentrations of the redox species Oz and Rz−1. Importantly, we demonstrate that the driving force for electron transfer can be different to the applied potential when electrostatic interactions are included. We also show that the concentrations of Oz and Rz−1 at the plane of electron transfer (PET) significantly depart from those predicted by the Nernst equation, even when the system is characterised by fast electron transfer/diffusion control. A mechanistic rationalisation is also presented as to why the electric double layer has a negligible effect on the CV response of such reversible systems. In contrast, for quasi-reversible electron transfer the concentrations of redox species at the PET are shown to play an important role in determining CV wave shape, an effect also dependant on the charge of the redox species and the formal electrode potential of the redox couple. Failure to consider electrostatic effects could lead to incorrect interpretation of electron-transfer kinetics from the CV response. Simulated CVs at scan rates between 0.1 and 1000 V s−1 are found to be in good agreement with experimental data for the reduction of 1.0 mM Ru(NH3)63+ at a 2 mm diameter gold disk electrode in 1.0 M potassium nitrate

Manipulating photorespiration to increase plant productivity:recent advances and perspectives for crop improvement

Recycling of the 2-phosphoglycolate generated by the oxygenase reaction of Rubisco requires a complex and energy-consuming set of reactions collectively known as the photorespiratory cycle. Several approaches aimed at reducing the rates of photorespiratory energy or carbon loss have been proposed, based either on screening for natural variation or by means of genetic engineering. Recent work indicates that plant yield can be substantially improved by the alteration of photorespiratory fluxes or by engineering artificial bypasses to photorespiration. However, there is also evidence indicating that, under certain environmental and/or nutritional conditions, reduced photorespiratory capacity may be detrimental to plant performance. Here we summarize recent advances obtained in photorespiratory engineering and discuss prospects for these advances to be transferred to major crops to help address the globally increasing demand for food and biomass production

Temperate migrants and resident bird species in Afro-tropical savannahs show similar levels of ecological generalism

We are grateful to the Leventis Conservation Foundation for funding this research and wish also to acknowledge and thank staff and field assistants at the A.P. Leventis Ornithological Research Institute (APLORI), Jos, Nigeria, for help with field travel and logistics.The specificity of an animal's habitat requirements will determine its ability to deal with anthropogenic climate and habitat change. Migratory birds are thought to be particularly vulnerable to such change, but theory predicts that they should be largely generalists. This prediction was tested with the aim of assessing whether migratory Palaearctic-breeding birds wintering in the savannah biome of Africa are more or less generalist in their habitat use compared with taxonomically and ecologically similar Afro-tropical resident species. The degree of specialization of these species groups to certain habitat characteristics was assessed and compared by calculating the relative occurrence of the species along habitat gradients, where wide occurrence indicates generalism and narrow occurrence indicates specialism. Palaearctic migrants as a group could not clearly be distinguished as generalists relative to Afro-tropical residents with respect to habitat attributes. The only indication of greater flexibility in Palaearctic migrants was a significant tendency to use habitats over a wider latitudinal range. The results suggest that migrants are generalists, but not necessarily more generalist than taxonomically similar resident species that also occur over a wide range of habitat types within the savannah biome. The availability of specific habitat requirements on the wintering grounds in Africa is therefore unlikely to be a primary limiting factor for many Afro-Palaearctic migratory bird species.PostprintPeer reviewe

Aptamer-based multiplexed proteomic technology for biomarker discovery

Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine

How do hospital boards govern for quality improvement? A mixed methods study of 15 organisations in England

Background Health systems worldwide are increasingly holding boards of healthcare organisations accountable for the quality of care that they provide. Previous empirical research has found associations between certain board practices and higher quality patient care; however, little is known about how boards govern for quality improvement (QI). Methods We conducted fieldwork over a 30-month period in 15 healthcare provider organisations in England as part of a wider evaluation of a board-level organisational development intervention. Our data comprised board member interviews (n=65), board meeting observations (60 hours) and documents (30 sets of board meeting papers, 15 board minutes and 15 Quality Accounts). We analysed the data using a framework developed from existing evidence of links between board practices and quality of care. We mapped the variation in how boards enacted governance of QI and constructed a measure of QI governance maturity. We then compared organisations to identify the characteristics of those with mature QI governance. Results We found that boards with higher levels of maturity in relation to governing for QI had the following characteristics: explicitly prioritising QI; balancing short-term (external) priorities with long-term (internal) investment in QI; using data for QI, not just quality assurance; engaging staff and patients in QI; and encouraging a culture of continuous improvement. These characteristics appeared to be particularly enabled and facilitated by board-level clinical leaders. Conclusions This study contributes to a deeper understanding of how boards govern for QI. The identified characteristics of organisations with mature QI governance seemed to be enabled by active clinical leadership. Future research should explore the biographies, identities and work practices of board-level clinical leaders and their role in organisation-wide QI