Tohoku University

About: Tohoku University is a education organization based out in Sendai, Japan. It is known for research contribution in the topics: Magnetization & Population. The organization has 72116 authors who have published 170791 publications receiving 3941714 citations. The organization is also known as: Tōhoku daigaku.

Spin Hall Magnetoresistance Induced by a Nonequilibrium Proximity Effect

Abstract: We report anisotropic magnetoresistance in Pt|Y3Fe5O12 bilayers. In spite of Y3Fe5O12 being a very good electrical insulator, the resistance of the Pt layer reflects its magnetization direction. The effect persists even when a Cu layer is inserted between Pt and Y3Fe5O12, excluding the contribution of induced equilibrium magnetization at the interface. Instead, we show that the effect originates from concerted actions of the direct and inverse spin Hall effects and therefore call it “spin Hall magnetoresistance.”

International trade drives biodiversity threats in developing nations

Abstract: Biodiversity threats from Red Lists are linked with patterns of international trade, identifying the ultimate instigators of the threats; developed countries tend to be net importers of implicated commodities, driving biodiversity decline in developing countries. This study develops a global model linking threatened-species records published in the International Union for the Conservation of Nature Red List to worldwide industries causing these threats through the production of commodities such as agricultural crops and timber. Close to one-third of global species threats are due to international trade, according to this model. The resulting 'biodiversity footprint' reveals how consumers in developed countries drive species threats in developing countries. The United States, European Union and Japan emerge as the main final destinations of biodiversity-implicated commodities, with the coffee, rubber, cocoa, palm oil, fisheries and forestry industries among the most destructive. Human activities are causing Earth’s sixth major extinction event1—an accelerating decline of the world’s stocks of biological diversity at rates 100 to 1,000 times pre-human levels2. Historically, low-impact intrusion into species habitats arose from local demands for food, fuel and living space3. However, in today’s increasingly globalized economy, international trade chains accelerate habitat degradation far removed from the place of consumption. Although adverse effects of economic prosperity and economic inequality have been confirmed4,5, the importance of international trade as a driver of threats to species is poorly understood. Here we show that a significant number of species are threatened as a result of international trade along complex routes, and that, in particular, consumers in developed countries cause threats to species through their demand of commodities that are ultimately produced in developing countries. We linked 25,000 Animalia species threat records from the International Union for Conservation of Nature Red List to more than 15,000 commodities produced in 187 countries and evaluated more than 5 billion supply chains in terms of their biodiversity impacts. Excluding invasive species, we found that 30% of global species threats are due to international trade. In many developed countries, the consumption of imported coffee, tea, sugar, textiles, fish and other manufactured items causes a biodiversity footprint that is larger abroad than at home. Our results emphasize the importance of examining biodiversity loss as a global systemic phenomenon, instead of looking at the degrading or polluting producers in isolation. We anticipate that our findings will facilitate better regulation, sustainable supply-chain certification and consumer product labelling.

The Role of Bacteria in the Caries Process: Ecological Perspectives

Abstract: Dental biofilms produce acids from carbohydrates that result in caries. According to the extended caries ecological hypothesis, the caries process consists of 3 reversible stages. The microflora on clinically sound enamel surfaces contains mainly non-mutans streptococci and Actinomyces, in which acidification is mild and infrequent. This is compatible with equilibrium of the demineralization/remineralization balance or shifts the mineral balance toward net mineral gain (dynamic stability stage). When sugar is supplied frequently, acidification becomes moderate and frequent. This may enhance the acidogenicity and acidurance of the non-mutans bacteria adaptively. In addition, more aciduric strains, such as ‘low-pH’ non-mutans streptococci, may increase selectively. These microbial acid-induced adaptation and selection processes may, over time, shift the demineralization/remineralization balance toward net mineral loss, leading to initiation/progression of dental caries (acidogenic stage). Under severe and p...

Persistent Propagation of Concentration Waves in Dissipative Media Far from Thermal Equilibrium

Abstract: The origin of persistent wave propagation through medium of reactwn-diffusion type 1s explored. Our theory is based on a generalized time-dependent Ginzburg-Landau equation for a complex field W, namely, the equation derived previously in connection with the instability problems in nonlinear chemical kinetics. For slow variation of lV in space and tune the above equation is further reduced to a Navier-Stokes-like one for the phase gradient of TV. Under a certain condition, the "viscosity" coefficient becomes negative, and at the :-;arne time the temporally ordered state of uniform concentrations becomes unstable. In :-;uch a situation we find a particular solution corresponding to a propagating concentratiOn wave with a wave-source or sink