Dry shear aligning: a simple and versatile method to smooth and align the surfaces of carbon nanotube thin films

Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.We show that the application of lateral shear force on a randomly oriented thin film of carbon nanotubes, in the dry state, causes significant reordering of the nanotubes at the film surface. This new technique of dry shear aligning is applicable to carbon nanotube thin films produced by many of the established methods

Second messenger-mediated tactile response by a bacterial rotary motor

When bacteria encounter surfaces, they respond with surface colonization and virulence induction. The mechanisms of bacterial mechanosensation and downstream signaling remain poorly understood. Here, we describe a tactile sensing cascade in Caulobacter crescentus in which the flagellar motor acts as sensor. Surface-induced motor interference stimulated the production of the second messenger cyclic diguanylate by the motor-associated diguanylate cyclase DgcB. This led to the allosteric activation of the glycosyltransferase HfsJ to promote rapid synthesis of a polysaccharide adhesin and surface anchoring. Although the membrane-embedded motor unit was essential for surface sensing, mutants that lack external flagellar structures were hypersensitive to mechanical stimuli. Thus, the bacterial flagellar motor acts as a tetherless sensor reminiscent of mechanosensitive channels

Stiff polymer in monomer ensemble

We make use of the previously developed formalism for a monomer ensemble and include angular dependence of the segments of the polymer chains thus described. In particular we show how to deal with stiffness when the polymer chain is confined to certain regions. We investigate the stiffness from the perspectives of a differential equation, integral equations, or recursive relations for both continuum and lattice models. Exact analytical solutions are presented for two cases, whereas numerical results are shown for a third case.Comment: 10 pages, including 6 figure

Identificación y análisis de los recursos económicos asignados a la segunda locomotora. Evolución, aciertos y desaciertos

Con la elaboración del presente documento, se pretende identificar y analizar los recursos económicos asignados a una de las locomotoras del gobierno del presidente Juan Manuel Santos en el marco de su plan de desarrollo Prosperidad para todos y el impacto social de esta asignación de recursos en el agro Colombiano, Así mismo evaluar el cumplimiento de dicha política publica y la generación de bienestar social en la población."With the production of the present document, one tries to identify and to analyze the economic resources assigned to one of the locomotives of the government of the president Juan Manuel Santos in the frame of his plan of development "" Prosperity for all "" and the social impact of this assignment of resources in the Colombian agro, Likewise to evaluate the fulfillment of the above mentioned politics publishes and the generation of social well-being in the population.

Natural occurrence of ochratoxin A contamination in commercial black and white pepper products.

The concentration of ochratoxin A (OTA) in 120 commercial pepper (84 pre-packed and 36 bulk samples), which consist of local and imported white and black pepper in powder and seed form in Malaysia were determined. The objective of the study was to investigate and compare OTA concentration in black pepper and white pepper being commercialized in Malaysia. Determination method was based on HPLC with fluorescence detection coupled with immunoaffinity column clean-up step. Mobile phase consisted of acetonitrile-water-acetic acid (49.5:49.5:1.0, v/v/v), and flow rate was 1 ml/min. The LOD was 0.02 ng/g, and the average recovery values of OTA ranged from 79.5 to 92.0% in black pepper and 81.2-90.3% in white pepper. A total of 57 samples (47.5%) were contaminated with OTA ranging from 0.15 to 13.58 ng/g. The results showed that there was a significant difference between type of pepper and brands. OTA concentration in black pepper was significantly higher than white pepper (p < 0.05). The highest concentration of ochratoxin, 13.58 ng/g, was detected in a sample of black pepper seed followed by 12.64 ng/g in a sample of black pepper powder, both were bulk samples purchased from open market

Born radicals? Prevent, positivism, and ‘race-thinking’

In the contemporary Western climate, counter-terrorism discourse dealing with so-called Islamic extremism appears to be obsessed with trying to understand the motives behind what prompts somebody to turn to terrorism. This paper will argue that attempts to locate extremist motives in such a way can be seen to reinforce earlier iterations of positivist criminology and race-thinking. Through a critical examination of the works of criminologist Cesare Lombroso, this paper will tease out the interconnections between his ‘criminal types’ thesis, and the British government’s current Prevent policy that seeks to identify ‘extremist types.’ By developing a rich critique of these positivist approaches, the paper will go on to question how we might think beyond the essentialism, reductivism, and racism/Islamophobia inherent within such frameworks. In this way, the paper raises a series of conceptual implications for criminology and terrorism studies, while at the same time, develops a contribution to critical race and ethnicity studies

Wetting films on chemically heterogeneous substrates

Based on a microscopic density functional theory we investigate the morphology of thin liquidlike wetting films adsorbed on substrates endowed with well-defined chemical heterogeneities. As paradigmatic cases we focus on a single chemical step and on a single stripe. In view of applications in microfluidics the accuracy of guiding liquids by chemical microchannels is discussed. Finally we give a general prescription of how to investigate theoretically the wetting properties of substrates with arbitrary chemical structures.Comment: 56 pages, RevTeX, 20 Figure

Technician components and requirements model for the formation and management of cooperation networks among civil construction companies

A indústria da Construção Civil possui um modo de operação semelhante ao das organizações virtuais, mas de forma não estruturada, deixando de proporcionar vantagens competitivas. Para tanto, o artigo propõe um Modelo de Requisitos e Componentes Técnicos, baseado na metodologia EKD (Enterprise Knwoledge Development), para auxiliar a formação e gerência de redes entre empresas da construção civil. Para a elaboração do modelo proposto, foi conduzida uma análise dos projetos internacionais mais relevantes no setor da construção além de estudo de casos contendo sete obras a fim de detectar seus objetivos e pontos falhos a serem reestruturados e adaptados para a indústria da construção civil brasileira. Não obstante, o modelo proposto baseou-se em uma adaptação das melhores práticas de uma arquitetura de referência para redes. Como resultado, a proposição viabiliza uma visão clara dos requisitos necessários, explora a necessidade de intensa comunicação e troca de informações, além de contribuir com pesquisas futuras no que tange a um futuro desenvolvimento de sistema de informação direcionado para este segmento econômico.The operational method of civil construction can be analyzed by the outlook of virtual organizations, however not yet structuralized, hence not providing competitive advantages. Thus, this article considers a Technical Components and Requirements Model, based on EKD methodology (Enterprise Knowledge Development), to assist in the formation and management of networks in civil construction companies. For the elaboration of the considered model, an analysis of the most important international construction projects was conducted, in addition to a case study from seven construction projects in order to detect their goals and defective points, to then be reorganized and adapted to the Brazilian civil construction industry. Moreover, the considered model was also based on an adaptation of reference architecture for civil construction networks. As a result, the proposal makes possible, to the stakeholders, a clear view of the necessary requirements, exploring the necessity of intense communication and exchange of information, besides contributing to future research works regarding a future development of an information system directed for this economic segment