Reversible Tuning of Collinear versus Chiral Magnetic Order by Chemical Stimulus

The Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction mediates collinear magnetic interactions via the conduction electrons of a non-magnetic spacer, resulting in a ferro- or antiferromagnetic magnetization in magnetic multilayers. The resulting spin-polarized charge transport effects have found numerous applications. Recently it has been discovered that heavy non-magnetic spacers are able to mediate an indirect magnetic coupling that is non-collinear and chiral. This Dzyaloshinskii-Moriya-enhanced RKKY (DME-RKKY) interaction causes the emergence of a variety of interesting magnetic structures, such as skyrmions and spin spirals. Applications using these magnetic quasi-particles require a thorough understanding and fine-tuning of the balance between the Dzyaloshinskii-Moriya interaction and other magnetic interactions, e.g., the exchange interaction and magnetic anisotropy contributions. Here, we show by spin-polarized scanning tunneling microscopy that the spin structure of manganese oxide chains on Ir(001) can reproducibly be switched from chiral to collinear antiferromagnetic interchain interactions by increasing the oxidation state of MnO$_2$ while the reverse process can be induced by thermal reduction. The underlying structural change is revealed by low-energy electron diffraction intensity data (LEED-IV) analysis. Density functional theory calculations suggest that the magnetic transition may be caused by a significant increase of the Heisenberg exchange upon oxidation.Comment: 6 pages, 3 figure

Que os façamos ouvir

Book Review of Se me deixam falar, by Moema Viezzer, with the narratives taken by the author of Domitlia Barrios, a Bolivian union leader who fought for the rights of her people, especially women and the working class during the various coups and dictatorships in the history of Bolivia. In addition to being a miner's wife, the union member was also the daughter of a miner and lived for most of her life in a state-owned mining company called Siglo XX, where workers' conditions were unhealthy. The book divides Domitila's narrative into her life, her situation, and her claims, all narrated without changes in Domitila's idioms. The book shows part of Latin American struggle processes from a feminine perspective, almost never found in large historical narratives. It uses a very close past so that we can bring new perspectives of fight of the same struggles for all the Latin American future.Reseña del libro Se me deixam falar, de Moema Viezzer, con las narrativas tomadas por la autora de Domitlia Barrios, una dirigente sindical boliviana que luchó por los derechos de su pueblo, especialmente de las mujeres y la clase trabajadora durante los diversos golpes y dictaduras en el Historia de Bolivia. Además de ser esposa de un minero, la sindicalista también era hija de un minero y vivió la mayor parte de su vida en una empresa minera estatal llamada Siglo XX, donde las condiciones de los trabajadores no eran saludables. El libro divide la narrativa de Domitila en su vida, su situación y sus afirmaciones, todo narrado sin cambios en los modismos de Domitila. El libro muestra parte de los procesos de lucha latinoamericanos desde una perspectiva femenina, casi nunca encontrada en grandes narrativas históricas. Utiliza un pasado muy cercano para que podamos traer nuevas perspectivas de lucha de las mismas luchas para todo el futuro latinoamericano.  Resenha sobre o livro Se me deixam falar, de Moema Viezzer, com as narrativas colhidas pela autora de Domitlia Barrios, líder sindicalista boliviana que lutou pelos direitos de seu povo, especialmente das mulheres e da classe trabalhadora durante os diversos golpes e ditaduras presentes na história da Bolívia. Além de esposa de mineiro, a sindicalista também era filha de um minerador e, morou por quase toda a sua vida em uma mineradora estatal chamada Siglo XX, onde as condições dos trabalhadores eram insalubres. O livro divide a narrativa de Domitila em sua vida, sua situação e sua e suas reivindicações, todas narradas sem que houvesse alterações nas expressões idiomáticas de Domitila. O livro mostra parte dos processos de luta latino-americanos a partir de uma perspectiva feminina, pouco encontrada em grandes narrativas históricas. Vale-se de um passado muito próximo para que possamos trazer novas perspectivas de luta para o futuro latino-americano. &nbsp

Timeline of health care–associated infections and pathogens after burn injuries

Infections are an important cause of morbidity and mortality after burn injuries. Here, we describe the timeline of infections and pathogens after burns

A rhetoric-in-context approach to building commitment to multiple strategic goals

There are still few explanations of the micro-level practices by which top managers influence employee commitment to multiple strategic goals. This paper argues that, through their language, top managers can construct a context for commitment to multiple strategic goals. We therefore propose a rhetoric-in-context approach to illuminate some of the micro practices through which top managers influence employee commitment. Based upon an empirical study of the rhetorical practices through which top managers influence academic commitment to multiple strategic goals in university contexts, we demonstrate relationships between rhetoric and context. Specifically, we show that rhetorical influences over commitment to multiple goals are associated with the historical context for multiple goals, the degree to which top managers' rhetoric instantiates a change in that context, and the internal consistency of the rhetorical practices used by top managers. Copyright © 2007 SAGE Publications

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

The mitochondrial NAD+ transporter (NDT1) plays important roles in cellular NAD+ homeostasis in \u3ci\u3eArabidopsis thaliana\u3c/i\u3e

Nicotinamide adenine dinucleotide (NAD+) is an essential coenzyme required for all living organisms. In eukaryotic cells, the final step of NAD+ biosynthesis is exclusively cytosolic. Hence, NAD+ must be imported into organelles to support their metabolic functions. Three NAD+ transporters belonging to the mitochondrial carrier family (MCF) have been biochemically characterized in plants. AtNDT1 (At2g47490), focus of the current study, AtNDT2 (At1g25380), targeted to the inner mitochondrial membrane, and AtPXN (At2g39970), located in the peroxisomal membrane. Although AtNDT1 was presumed to reside in the chloroplast membrane, subcellular localization experiments with green fluorescent protein (GFP) fusions revealed that AtNDT1 locates exclusively in the mitochondrial membrane in stably transformed Arabidopsis plants. To understand the biological function of AtNDT1 in Arabidopsis, three transgenic lines containing an antisense construct of AtNDT1 under the control of the 35S promoter alongside a T-DNA insertional line were evaluated. Plants with reduced AtNDT1 expression displayed lower pollen viability, silique length, and higher rate of seed abortion. Furthermore, these plants also exhibited an increased leaf number and leaf area concomitant with higher photosynthetic rates and higher levels of sucrose and starch. Therefore, lower expression of AtNDT1 was associated with enhanced vegetative growth but severe impairment of the reproductive stage. These results are discussed in the context of the mitochondrial localization of AtNDT1 and its important role in the cellular NAD+ homeostasis for both metabolic and developmental processes in plants

Attraction of the Invasive Halyomorpha halys (Hemiptera: Pentatomidae) to Traps Baited with Semiochemical Stimuli Across the United States

A recent identification of the two-component aggregation pheromone of the invasive stink bug species, Halyomorpha halys (Stål), in association with a synergist, has greatly improved the ability to accurately monitor the seasonal abundance and distribution of this destructive pest. We evaluated the attraction of H. halys to black pyramid traps baited with lures containing the pheromone alone, the synergist methyl (2E,4E,6Z)-decatrienoate (MDT) alone, and the two lures in combination. Traps were deployed around areas of agricultural production including fruit orchards, vegetables, ornamentals, or row crops in Delaware, Maryland, North Carolina, New Jersey, New York, Ohio, Oregon, Pennsylvania, Virginia, and West Virginia from mid-April to mid-October, 2012 and 2013. We confirmed that H. halys adults and nymphs are attracted to the aggregation pheromone season long, but that attraction is significantly increased with the addition of the synergist MDT. H. halys adults were detected in April with peak captures of overwintering adults in mid- to late May. The largest adult captures were late in the summer, typically in early September. Nymphal captures began in late May and continued season long. Total captures declined rapidly in autumn and ceased by mid-October. Captures were greatest at locations in the Eastern Inland region, followed by those in the Eastern Coastal Plain and Pacific Northwest. Importantly, regardless of location in the United States, all mobile life stages of H. halys consistently responded to the combination of H. halys aggregation pheromone and the synergist throughout the entire season, suggesting that these stimuli will be useful tools to monitor for H. halys in managed system