Using transcranial direct-current stimulation (tDCS) to understand cognitive processing

Noninvasive brain stimulation methods are becoming increasingly common tools in the kit of the cognitive scientist. In particular, transcranial direct-current stimulation (tDCS) is showing great promise as a tool to causally manipulate the brain and understand how information is processed. The popularity of this method of brain stimulation is based on the fact that it is safe, inexpensive, its effects are long lasting, and you can increase the likelihood that neurons will fire near one electrode and decrease the likelihood that neurons will fire near another. However, this method of manipulating the brain to draw causal inferences is not without complication. Because tDCS methods continue to be refined and are not yet standardized, there are reports in the literature that show some striking inconsistencies. Primary among the complications of the technique is that the tDCS method uses two or more electrodes to pass current and all of these electrodes will have effects on the tissue underneath them. In this tutorial, we will share what we have learned about using tDCS to manipulate how the brain perceives, attends, remembers, and responds to information from our environment. Our goal is to provide a starting point for new users of tDCS and spur discussion of the standardization of methods to enhance replicability.The authors declare that they had no conflicts of interest with respect to their authorship or the publication of this article. This work was supported by grants from the National Institutes of Health (R01-EY019882, R01-EY025272, P30-EY08126, F31-MH102042, and T32-EY007135). (R01-EY019882 - National Institutes of Health; R01-EY025272 - National Institutes of Health; P30-EY08126 - National Institutes of Health; F31-MH102042 - National Institutes of Health; T32-EY007135 - National Institutes of Health)Accepted manuscrip

Multi-level multi-criteria analysis of alternative fuels for waste collection vehicles in the United States

Historically, the U.S. waste collection fleet was dominated by diesel-fueled waste collection vehicles (WCVs); the growing need for sustainable waste collection has urged decision makers to incorporate economically efficient alternative fuels, while mitigating environmental impacts. The pros and cons of alternative fuels complicate the decisions making process, calling for a comprehensive study that assesses the multiple factors involved. Multi-criteria decision analysis (MCDA) methods allow decision makers to select the best alternatives with respect to selection criteria. In this study, two MCDA methods, Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Simple Additive Weighting (SAW), were used to rank fuel alternatives for the U.S. waste collection industry with respect to a multi-level environmental and financial decision matrix. The environmental criteria consisted of life-cycle emissions, tail-pipe emissions, water footprint (WFP), and power density, while the financial criteria comprised of vehicle cost, fuel price, fuel price stability, and fueling station availability. The overall analysis showed that conventional diesel is still the best option, followed by hydraulic-hybrid WCVs, landfill gas (LFG) sourced natural gas, fossil natural gas, and biodiesel. The elimination of the WFP and power density criteria from the environmental criteria ranked biodiesel 100 (BD100) as an environmentally better alternative compared to other fossil fuels (diesel and natural gas). This result showed that considering the WFP and power density as environmental criteria can make a difference in the decision process. The elimination of the fueling station and fuel price stability criteria from the decision matrix ranked fossil natural gas second after LFG-sourced natural gas. This scenario was found to represent the status quo of the waste collection industry. A sensitivity analysis for the status quo scenario showed the overall ranking of diesel and fossil natural gas to be more sensitive to changing fuel prices as compared to other alternatives

Ist Mobilität finanzierbar?

Die nebenstehende Abbildung zeigt einen Blick auf die Erde bei Nacht. Dank moderner Satellitentechnik gelingt ein Blick auf die gesamte Erde, die Wolken sind weggeschoben und die erleuchteten Städte und Regionen zeigen eindrucksvoll die Verteilung menschlicher Aktivität und wirtschaftlicher Leistungsfähigkeit. Afrika liegt im Dunkeln. Die Wiege der Menschheit wurde aufgegeben. Mittlerweile lebt die Menschheit in den großen Zentren entlang der Küste, an den großen Flussmündungen. Zunächst wurde Europa, Asien, mit Indien und China besiedelt. Vor 50.000 Jahren dann Australien und vor 15.000 Jahren Amerika. Das Bild zeigt eindrucksvoll die Mobilität, die vor über 60.000 Jahren eingesetzt hat. Zu Fuß, zu Pferd und vor allem per Schiff erfolgte der Aufbruch. Segelschiffe stehen für die Ursprünge der von Menschen benutzter technischer Hilfsmittel. Mit der Erfindung des Rads vor 6.000 Jahren erfolgte ein erster Technologiesprung. Schließlich ist mit den neu entstandenen Verkehrstechniken wie der Dampfmaschine, des Verbrennungsmotors und des Flugzeugs, ein riesiger Mobilitätsschub angestoßen worden. Diese Ausweitung menschlicher Aktivität stützt sich auf ein Verkehrssystem das außer auf den Verkehrsmitteln vor allem auf den Verkehrsnetzen beruht. Es ist ein weltumspannendes immer umfassender und wertvolleres System und die Frage heißt: Ist unsere heutige Mobilität noch finanzierbar? Die Überlegungen zur Finanzierung unserer Mobilität sollen anhand von drei Thesen erläutert werden