353 research outputs found
Economic Development, Democratic Institutions, and Repression in Non-democratic Regimes: Theory and Evidence
This paper analyzes the utilization of repression and democratic institutions by a non-democratic government striving for political power and private rents. We find that economic development has different impacts on policy choices, depending on whether it appears in the form of rises in income or in education: A higher income level reduces democracy, whereas more education leads to both more democracy and more repression. These theoretical findings are corroborated by panel data regressions
It Takes Two â Coincidence coding within the dual olfactory pathway of the honeybee
To rapidly process biologically relevant stimuli, sensory systems have developed a broad variety of coding mechanisms like parallel processing and coincidence detection. Parallel processing (e.g., in the visual system), increases both computational capacity and processing speed by simultaneously coding different aspects of the same stimulus. Coincidence detection is an efficient way to integrate information from different sources. Coincidence has been shown to promote associative learning and memory or stimulus feature detection (e.g., in auditory delay lines). Within the dual olfactory pathway of the honeybee both of these mechanisms might be implemented by uniglomerular projection neurons (PNs) that transfer information from the primary olfactory centers, the antennal lobe (AL), to a multimodal integration center, the mushroom body (MB). PNs from anatomically distinct tracts respond to the same stimulus space, but have different physiological properties, characteristics that are prerequisites for parallel processing of different stimulus aspects. However, the PN pathways also display mirror-imaged like anatomical trajectories that resemble neuronal coincidence detectors as known from auditory delay lines. To investigate temporal processing of olfactory information, we recorded PN odor responses simultaneously from both tracts and measured coincident activity of PNs within and between tracts. Our results show that coincidence levels are different within each of the two tracts. Coincidence also occurs between tracts, but to a minor extent compared to coincidence within tracts. Taken together our findings support the relevance of spike timing in coding of olfactory information (temporal code)
The silence of self-knowledge
Gareth Evans famously affirmed an explanatory connection between answering the question whether p and knowing whether one believes that p. This is commonly interpreted in terms of the idea that judging that p constitutes an adequate basis for the belief that one believes that p. This paper formulates and defends an alternative, more modest interpretation, which develops from the suggestion that one can know that one believes that p in judging that p
Retuning the Catalytic Bias and Overpotential of a [NiFe]-Hydrogenase via a Single Amino Acid Exchange at the Electron Entry/Exit Site
The redox chemistry of the electron entry/exit site in Escherichia coli hydrogenase-1 is shown to play a vital role in tuning biocatalysis. Inspired by nature, we generate a HyaA-R193L variant to disrupt a proposed Arg-His cation-Ď interaction in the secondary coordination sphere of the outermost, "distal", iron-sulfur cluster. This rewires the enzyme, enhancing the relative rate of H 2 production and the thermodynamic efficiency of H 2 oxidation catalysis. On the basis of Fourier transformed alternating current voltammetry measurements, we relate these changes in catalysis to a shift in the distal [Fe 4S 4] 2+/1+ redox potential, a previously experimentally inaccessible parameter. Thus, metalloenzyme chemistry is shown to be tuned by the second coordination sphere of an electron transfer site distant from the catalytic center
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Use of the GlideScopeÂŽ-Ranger for pre-hospital intubations by anaesthesia trained emergency physicians â an observational study
Background: Pre-hospital endotracheal intubation is more difficult than in the operating room (OR). Therefore, enhanced airway management devices such as video laryngoscopes may be helpful to improve the success rate of pre-hospital intubation. We describe the use of the GlidescopeÂŽ-Ranger (GS-R) as an alternative airway tool used at the discretion of the emergency physician (EP) in charge. Methods: During a 3.5 year period, the GS-R was available to be used either as the primary or backup tool for pre-hospital intubation by anaesthesia trained EP with limited expertise using angulated videolaryngoscopes. Results: During this period 672 patients needed pre-hospital intubation of which the GS-R was used in 56 cases. The overall GS-R success rate was 66 % (range of 34â100 % among EP). The reasons for difficulties or failure included inexperience of the EP with the GS-R, impaired view due to secretion, vomitus, blood or the inability to see the screen in very bright environment due to sunlight. Conclusion: Special expertise and substantial training is needed to successfully accomplish tracheal intubation with the GS-R in the pre-hospital setting. Providers inexperienced with DL as well as video-assisted intubation should not expect to be able to perform tracheal intubation easily just because a videolaryngoscope is available. Additionally, indirect laryngoscopy might be difficult or even impossible to achieve in the pre-hospital setting due to impeding circumstances such as blood, secretions or bright sun-light. Therefore, videolaryngoscopes, here the GS-R, should not be considered as the âHoly Grailâ of endotracheal intubation, neither for the experts nor for inexperienced providers. Electronic supplementary material The online version of this article (doi:10.1186/s12873-016-0069-2) contains supplementary material, which is available to authorized users
Three-Phase Catalytic Hydrogenation of a Functionalized Alkyne: Mass Transfer and Kinetic Studies with in Situ Hydrogen Monitoring
Systematic studies of mass transfer interactions with intrinsic reaction kinetics were performed for the threephase selective hydrogenation of 2-methyl-3-butyn-2-ol (MBY) to 2-methyl-3-buten-2-ol (MBE) over a modified Pd/CaC catalyst under solvent free conditions. Hydrogen concentration in the liquid phase () was monitored in situ during the catalytic reaction by means of the Fugatronâ analyzer. Reactions were carried out in an autoclave at different stirring rates at two concentrations of hydrogen (5 and 13 mol ¡ For stirring speeds higher than 1500 rpm no influence of gas-liquid mass transfer was observed. Hydrogen liquid-solid (L-S) mass transfer was found to be negligible, whereas the MBY mass L-S transfer becomes important at high MBY conversions at high hydrogen concentration. Low stirrer speed caused the reaction rate and MBE selectivity to decrease. No internal mass transfer limitations were observed, and conditions for the kinetic regime were found. The kinetics modeled ollowed the Langmuir-Hinshelwood mechanism and was consistent with the experimental data
Dose-dependent long-term effects of a single radiation event on behaviour and glial cells
Purpose The increasing use of low-dose ionizing radiation in medicine requires a systematic study of its long-term effects on the brain, behaviour and its possible association with neurodegenerative disease vulnerability. Therefore, we analysed the long-term effects of a single low-dose irradiation exposure at 10 weeks of age compared to medium and higher doses on locomotor, emotion-related and sensorimotor behaviour in mice as well as on hippocampal glial cell populations. Materials and methods We determined the influence of radiation dose (0, 0.063, 0.125 or 0.5 Gy), time post-irradiation (4, 12 and 18 months p.i.), sex and genotype (wild type versus mice with Ercc2 DNA repair gene point mutation) on behaviour. Results The high dose (0.5 Gy) had early-onset adverse effects at 4 months p.i. on sensorimotor recruitment and late-onset negative locomotor effects at 12 and 18 months p.i. Notably, the low dose (0.063 Gy) produced no early effects but subtle late-onset (18 months) protective effects on sensorimotor recruitment and exploratory behaviour. Quantification and morphological characterization of the microglial and the astrocytic cells of the dentate gyrus 24 months p.i. indicated heightened immune activity after high dose irradiation (0.125 and 0.5 Gy) while conversely, low dose (0.063 Gy) induced more neuroprotective features. Conclusion This is one of the first studies demonstrating such long-term and late-onset effects on brain and behaviour after a single radiation event in adulthood
Neck pain and anxiety do not always go together
Chronic pain and psychosocial distress are generally thought to be associated in chronic musculoskeletal disorders such as non-specific neck pain. However, it is unclear whether a raised level of anxiety is necessarily a feature of longstanding, intense pain amongst patient and general population sub-groups. In a cohort of 70 self-selected female, non-specific neck pain sufferers, we observed relatively high levels of self-reported pain of 4.46 (measured on the 11 point numerical pain rating scale (NRS-101)) and a longstanding duration of symptoms (156 days/year). However, the mean anxiety scores observed (5.49), fell well below the clinically relevant threshold of 21 required by the Beck Anxiety Inventory. The cohort was stratified to further distinguish individuals with higher pain intensity (NRS>6) and longer symptom duration (>90 days). Although a highly statistically significant difference (p = 0.000) was subsequently observed with respect to pain intensity, in the resulting sub-groups, none such a difference was noted with respect to anxiety levels. Our results indicate that chronic, intense pain and anxiety do not always appear to be related. Explanations for these findings may include that anxiety is not triggered in socially functional individuals, that individual coping strategies have come into play or in some instances that a psychological disorder like alexithymia could be a confounder. More studies are needed to clarify the specific role of anxiety in chronic non-specific musculoskeletal pain before general evidence-driven clinical extrapolations can be made
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