Search results for " MEC"
showing 10 items of 8161 documents
A Microscopic Description of SARS-CoV-2 Main Protease Inhibition with Michael Acceptors. Strategies for Improving Inhibitors Design
2020
The irreversible inhibition of the main protease of SARS-CoV-2 by a Michael acceptor known as N3 has been investigated using multiscale methods. The noncovalent enzyme–inhibitor complex was simulated using classical molecular dynamics techniques and the pose of the inhibitor in the active site was compared to that of the natural substrate, a peptide containing the Gln–Ser scissile bond. The formation of the covalent enzyme–inhibitor complex was then simulated using hybrid QM/MM free energy methods. After binding, the reaction mechanism was found to be composed of two steps: (i) the activation of the catalytic dyad (Cys145 and His41) to form an ion pair and (ii) a Michael addition where the …
The antimicrobial activity of honey and propolis extracts from the central region of Romania
2021
Abstract Honey and propolis from Apis mellifera (bees) are products that have been used due to their multiple biological properties. The antimicrobial activity of 10 honey samples of known origin and 4 propolis extracts gathered from the same beekeepers located in Transylvania, Romania, were used against certain microorganisms: Escherichia coli, Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa and Candida albicans. The study also investigated the positive interaction of propolis aqueous extracts when used with poly-floral honey against the same microorganisms. The most sensitive to the activity of honey samples was the S. aureus strain (the largest inhibition area 18 mm) for p…
Adaptive inputs in an interface for people with Dyskinetic Cerebral Palsy: Learning and usability
2016
This study concerns the difficulty in accessing computers faced by people with Dyskinetic Cerebral Palsy (DCP). Thus diminishing their opportunities to communicate or learn. This population usually needs an alternative input human-computer interface (HCI). The paper presents an alternative multimodal HCI that incorporates a head-mounted interface and superficial electromyography sensors (sEMG). The aim of the study is to assess the usability and the suitability of these two HCI devices. Six non-disabled subjects and ten subjects with DCP participated in the iterative process in which each test follows an improvement of an input. The results indicated that for both systems, the improvements …
Drift and evolutionary forces
2016
This arride analyzes the view of evolutionary theory as a theory of forces. The analogy with Newtonian mechanics has been challenged due to the alleged mismatch between drift and the other evolutionary forces. Since genetic drifr has no direction severa! authors tried to protect its status as a force: denying its lack of directionality, extending the notion of force and looking for a force in physics which also lacks of direction. I analyse these approaches, and although this strategy finally succeeds, this discussion overlooks the crucial point on the debate between causalists and statisticalists: the causal status of evolutionary theoty.; El presente artículo analiza la visión de la teorí…
Interventions with Sticky Social Norms: A Critique
2021
Abstract We study the consequences of policy interventions when social norms are endogenous but costly to change. In our environment, a group faces a negative externality that it partially mitigates through incentives in the form of punishments. In this setting, policy interventions can have unexpected consequences. The most striking is that when the cost of bargaining is high, introducing a Pigouvian tax can increase output—yet in doing so increase welfare. An observer who saw that an increase in a Pigouvian tax raised output might wrongly conclude that this harmed welfare and that a larger tax increase would also raise output. This counter-intuitive impact on output is demonstrated theore…
A Note on Laws of Motion for Aggregate Distributions
2020
I derive the law of motion for the aggregate distribution directly from the laws of motion for the individuals’ states. By relying on concepts from measure theory, the derivation is concise and intuitive. I address random shocks both at the micro level and at the macro level. Micro-level shocks completely cancel at the aggregate level provided that a law of large numbers applies. Therefore, the law of motion for the aggregate distribution is a deterministic process in the absence of macro-level uncertainty. If there are macro-level risks, the law of motion for the aggregate distribution exhibits a stochastic component additionally. I illustrate the formalism in a model of wealth accumulatio…
Informal, formal institutions and credit: complements or substitutes?
2019
AbstractThis paper analyses the relationship between informal institutions measured by social trust and the provision of private credit. Research on the trust–finance relationship abounds, although most of it is confined to the micro-level, with far fewer contributions from a wide, cross-country perspective. Considering a sample of 119 economies in the period 1993–2015, results suggest that social trust is an important determinant of private credit, and that its effects are transmitted indirectly via some particular aspects of the quality of economic-judicial institutions. In addition, and contrary to previous findings in related areas, substitutive effects for informal and formal instituti…
A comparative analysis between helicopter and seaplane for passenger transport.
2016
Purpose This study aims to develop a methodology to compare the feasibility of helicopter and seaplane regular transport of passengers towards destinations across a remote regional tourist context, where a lack of road and rail infrastructure make these alternative forms of air transport competitive. Design/methodology/approach The authors use a modal split model identifying the quota of passengers that potentially could utilize these two types of services, determined on the basis of previous studies on air transport demand. A technical analysis regarding transport supply is performed to identify the predominant features that should characterize helicopter/seaplane performances. An optimiza…
Multi-criteria analysis applied to multi-objective optimal pump scheduling in water systems
2019
Abstract This work presents a multi-criteria-based approach to automatically select specific non-dominated solutions from a Pareto front previously obtained using multi-objective optimization to find optimal solutions for pump control in a water supply system. Optimal operation of pumps in these utilities is paramount to enable water companies to achieve energy efficiency in their systems. The Fuzzy Technique for Order of Preference by Similarity to Ideal Solution (FTOPSIS) is used to rank the Pareto solutions found by the non-dominated sorting genetic algorithm (NSGA-II) employed to solve the multi-objective problem. Various scenarios are evaluated under leakage uncertainty conditions, res…
SAFETY CONSIDERATIONS ON TEENAGE PEDESTRIAN-BUS IMPACT
2019
This work studies the impact conditions between the adolescent pedestrian and the bus focusing on head and chest injury. The injury to the head is analyzed using both the Head Injury Criterion (HIC) 36 and the HIC15 parameters as established by the most advanced legislation and comparing the risk probability Abbreviated Injury Scale (AIS3+) and AIS4+. The parameter HIC15 gives a higher probability of risk with lower values, and therefore it can be considered more conservative. Moreover, the study of chest injury is performed with two different biomechanical parameters: the Thoracic Trauma Index (TTI) and the TTI(d); the last neglects the pedestrian mass. The results indicate that the param…