508 research outputs found
Book Review: What’s Luck Got to Do with It? The History, Mathematics, and Psychology of the Gambler’s Illusion by Joseph Mazur
This review of Joseph Mazur\u27s book on the history of gambling, for a general audience, is in three parts, paralleling the structure of the book. The first part briefly outlines Mazur\u27s coverage of the history of probability from prehistory to the present day, with a focus on gambling. The second part examines the relationship between the mathematics of gambling and probability theory, and summarizes classical problems in probability arising from gambling such as Galileo\u27s dice and the Pascal-Fermat problem of points. The third part, on psychology, discusses the gambler\u27s illusion and psychological motivations for gambling
Exome sequencing of 85 Williams–Beuren syndrome cases rules out coding variation as a major contributor to remaining variance in social behavior
Effect of Subinhibitory Concentrations of Antibiotics and Disinfectants on ISAba-Mediated Inactivation of Lipooligosaccharide Biosynthesis Genes in Acinetobacter baumannii
Inactivation of the lipooligosaccharide (LOS) biosynthesis genes lpxA, lpxC and lpxD by ISAba insertion elements results in high-level resistance to colistin in A. baumannii. In the present study, we quantify the rate of spontaneous insertional inactivation of LOS biosynthesis genes by ISAba elements in the ATCC 19606-type strain and two multidrug clinical isolates. Using insertional inactivation of lpxC by ISAba11 in the ATCC 19606 strain as a model, we determine the effect of several subinhibitory concentrations of the antibiotics, namely tetracycline, ciprofloxacin, meropenem, kanamycin and rifampicin, as well as the disinfectants ethanol and chlorhexidine on ISAba11 insertion frequencies. Notably, subinhibitory concentrations of tetracycline significantly increased ISAba11 insertion, and rifampicin completely inhibited the emergence of colistin resistance due to ISAba11 inactivation of lpxC. Sequencing of ISAba11 insertion sites within the lpxC gene demonstrated that insertions clustered between nucleotides 382 and 618 (58.3% of unique insertions detected), indicating that this may be a hotspot for ISAba11 insertion. The alignment of insertion sites revealed a semi-conserved AT-rich consensus sequence upstream of the ISAba11 insertion site, suggesting that ISAba11 insertion sites may be sequence-dependent. This study explores previously uncharacterized aspects regarding the acquisition of colistin resistance through insertional activation in LOS biosynthesis genes in A. baumannii.This research was supported by grants MPY 380/18 from the Instituto de Salud Carlos III (ISCIII) awarded to M.J.M. A.C.L. is supported by the Atracción de Talento Program of the Community of Madrid.S
Prueba de habilidades prácticas CCNA.
Prueba de habilidades prácticas CCNA.La evaluación denominada “Prueba de habilidades prácticas”, forma parte de las actividades evaluativas del Diplomado de Profundización CCNA, y busca identificar el grado de desarrollo de competencias y habilidades que fueron adquiridas a lo largo del diplomado. Lo esencial es poner a prueba los niveles de comprensión y solución de problemas relacionados con diversos aspectos de Networking. A continuación, se elaboran dos escenarios correspondientes a la temática de implementación de soluciones soportadas en enrutamiento avanzado como etapa final del curso Diplomado de Profundización CCNA.The evaluation called "Test of practical skills" is part of
the evaluation activities of the CCNA Deepening Diploma, and search
identify the degree of development of competencies and skills that were
acquired throughout the course. The essential thing is to test the levels
of understanding and solving problems related to various aspects
of Networking.
Then, two scenarios corresponding to the theme of
Implementation of solutions supported in advanced routing as
final stage of the course Diploma of Deepening CCNA
A New Thin Layered Structural Coating on a Metal Substrate for Enhanced hydrogen Production from Steam Methane Reforming
In the past decade the use of hydrogen has become more ubiquitous. Its applications range from the upgrading of fossil fuels, to the production of ammonia, to the hydrogenation of fats, to the production of muriatic acid and methanol, all without including the efforts being taken to move towards a hydrogen economy. Its widespread use and its increasing demand lays pressure to find more efficient techniques of hydrogen production. Because the overwhelming majority of hydrogen produced nowadays comes from the steam reforming of natural gas (SMR), it appears that the most adept way to improve yields is by improving the SMR process. This thesis compiles the efforts taken to characterize the performance and kinetics of a new type of catalyst coating technique which promises enhanced hydrogen production from SMR. To achieve this, a total of 49 experiments were performed at different temperature, pressure and space-time conditions for different inlet distributions
Cyclic thermal fluctuations can be burden or relief for an ectotherm depending on fluctuations’ average and amplitude
1. Predicting the implications of ongoing ocean climate warming demands a better understanding of how short-term thermal variability impacts marine ectotherms, particularly at beyond-optimal average conditions during summer heatwaves.
2. Using a globally important model species, the blue mussel Mytilus, in a 5-week-long experiment, we (a) assessed growth performance traits under 12 scenarios, consisting of four thermal averages (18.5, 21, 23.5 and 26℃) imposed as constant or daily fluctuating regimes with amplitudes of 2 or 4℃. Additionally, we conducted a short-term assay using different mussel individuals to (b) test for the species capacity for suppression and recovery of metabolic performance traits (feeding and aerobic respiration) when exposed to a 1-day thermal fluctuation regime (16.8–30.5℃). Using this high-resolution data, we (c) generated short-term thermal metabolic performance curves to predict and explain growth responses observed in the long-term experiment.
3. We found that daily high-amplitude thermal cycles (4℃) improved mussel growth when fluctuations were imposed around an extreme average temperature of 26℃, representing end-of-century heatwaves. In contrast, thermal cycles negatively affected mussel growth at a less extreme average temperature of 23.5℃, resembling current peak summer temperature scenarios. These results suggest that fluctuations ameliorate heat stress impacts only at critically high average temperatures. The short-term assay demonstrated that during the warming phase, animals stopped feeding between 24 and 30℃ while gradually suppressing respiration. In the subsequent cooling phase, feeding and respiration partially and fully recovered to pre-heating rates respectively. Furthermore, nonlinear averaging of short-term feeding responses (upscaling) well-predicted longer term growth responses to fluctuations.
4. Our findings suggest that fluctuations can be beneficial to or detrimental for the long-term performance of ectothermic animals, depending on the fluctuations' average and amplitude. Furthermore, the observed effects can be linked to fluctuation-mediated metabolic suppression and recovery. In a general framework, we propose various hypothetical scenarios of fluctuation impacts on ectotherm performance considering inter- or intra-species variability in heat sensitivity. Our research highlights the need for studying metabolic performance in relation to cyclic abiotic fluctuations to advance the understanding of climate change impacts on aquatic systems
An Experimental Investigation of Strain Rate, Temperature and Humidity Effects on the Mechanical Behavior of a Perfluorosulfonic Acid Membrane
The time-dependent hygro-thermal mechanical behavior of a perfluorosulfonic acid (PFSA) membrane (Nafion® 211 membrane) commonly used in Proton Exchange Membrane Fuel Cells (PEMFCs) is investigated at selected strain rates for a broad range of temperatures and humidities. Tensile tests and relaxation tests are conducted to determine Young’s modulus and proportional limit stress as functions of strain rate, temperature and humidity. The results show that Young’s modulus and proportional limit stress increase as the strain rate increases, and decrease as the temperature or humidity increases. The results also show that the mechanical response of Nafion® 211 membrane is more sensitive to typical changes in strain rate or temperature than to typical changes in humidity. In addition, two temperature/humidity cycles are conducted to determine the steady state swelling behavior of Nafion® 211 membrane as a function of temperature and humidity. The results show that the membrane swells with increasing temperature and humidity, and that there is little or no hygro-thermal history effect for the swelling strains
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