Who students interact with? A social network analysis perspective on the use of Twitter in language learning

This paper reports student interaction patterns and self-reported results of using Twitter microblogging environment. The study employs longitudinal probabilistic social network analysis (SNA) to identify the patterns and trends of network dynamics. It is building on earlier works that explore associations of student achievement records with the observed network measures. It integrates gender as an additional variable and reports some relation with interaction patterns. Additionally, the paper reports the results of a questionnaire that enables further discussion on the communication patterns

Institutional factors influencing innovation adoption by dairy farmers in Ireland

Location-based resources are important factors in the entrepreneurial creation of wealth. This is as true in agriculture as it is in other industrial contexts. In this study, we are interested in how formal and informal institutions such as knowledge networks and localized ‘webs’ of influence act to facilitate or block innovation in the dairy farming industry. Our study of dairy farmers in Munster, Republic of Ireland (an intensive location for dairy farming), is located in a context in which there are policy-based interventions intended to improve the local economic environment. We are interested to know if these are effective, or if other factors within the institutional field are too strong and act to impede the take up of new ideas promoted within such initiatives. Our study uses neo institutional theory as the methodological lens through which we assess the interplay of structural factors within the field. Using interview accounts, we are looking for evidence of embedded institutional logics, interpretive schemas, knowledge blockages, and the role of formal institutions on the development of innovation within the field. Through undertaking a deep study of innovativeness in one locale, Munster, with the proviso that we use this as an illuminatory context and not one that is necessarily representative of a wider field, we contribute to an understanding of the influences on resistance to innovation in farming contexts, and to the wider theoretical field of agricultural economics

Competing periodicities in fractionally filled one-dimensional bands

We present a variable temperature Scanning Tunneling Microscopy and Spectroscopy (STM and STS) study of the Si(553)-Au atomic chain reconstruction. This quasi one-dimensional (1D) system undergoes at least two charge density wave (CDW) transitions at low temperature, which can be attributed to electronic instabilities in the fractionally-filled 1D bands of the high-symmetry phase. Upon cooling, Si(553)-Au first undergoes a single-band Peierls distortion, resulting in period doubling along the imaged chains. This Peierls state is ultimately overcome by a competing tripleperiod CDW, which in turn is accompanied by a x2 periodicity in between the chains. These locked-in periodicities indicate small charge transfer between the nearly half-filled and quarter-filled 1D bands. The presence and the mobility of atomic scale dislocations in the x3 CDW state indicates the possibility of manipulating phase solitons carrying a (spin,charge) of (1/2,+-e/3) or (0,+-2e/3).Comment: submitted, accepted for publication in Phys. Rev. Let

Misplaced Gender diversity policies and practices in the British construction industry: developing and inclusive and transforming strategy

Why has diversity management in construction made so little difference to women’s participation at professional and in particular at operatives’ levels? This chapter addresses this question by examining the policies and practices put forward to combat low gender participation, their focus, the case on which they are built, and the degree to which the structure of the industry in Britain is conducive to their implementation. Drawing on existing literature, extensive research of our own and analyses of census, industry and WERS (Work and Employment Relations Survey) statistics, the relative irrelevance of a ‘business case’ for greater gender participation in construction is shown, given that this is primarily focussed on persuading employers to take responsibility for changing the situation. To have an impact, diversity measures have to be integral, specific, contextual and mandatory and developed in participation with employees and in parallel with appropriate recruitment, training, employment and working conditions, and support mechanism that drive the inclusion of women in the construction sector, particularly those at operative level. The lack of progress in gender participation is because such an approach has not yet been realised

Stochastic Blockmodeling for the Analysis of Big Data

The aim of this paper is to consider the stochastic blockmodel to obtain clusters of units as regards patterns of similar relations; moreover we want to analyze the relations between clusters. Blockmodeling is a technique usually applied in social network analysis focusing on the relations between \u201cactors\u201d i.e. units. In our time people and devices constantly generate data. The network is generating location and other data that keeps services running and ready to use in every moment. This rapid development in the availability and access to data has induced the need for better analysis techniques to understand the various phenomena. Blockmodeling techniques and Clustering algorithms, can be used for this aim. In this paper application regards the Web

Formation of atom wires on vicinal silicon

The formation of atomic wires via pseudomorphic step-edge decoration on vicinal silicon surfaces has been analyzed for Ga on the Si(112) surface using Scanning Tunneling Microscopy and Density Functional Theory calculations. Based on a chemical potential analysis involving more than thirty candidate structures and considering various fabrication procedures, it is concluded that pseudomorphic growth on stepped Si(112), both under equilibrium and non-equilibrium conditions, must favor formation of Ga zig-zag chains rather than linear atom chains. The surface is non-metallic and presents quasi-one dimensional character in the lowest conduction band.Comment: submitte

Ga-induced atom wire formation and passivation of stepped Si(112)

We present an in-depth analysis of the atomic and electronic structure of the quasi one-dimensional (1D) surface reconstruction of Ga on Si(112) based on Scanning Tunneling Microscopy and Spectroscopy (STM and STS), Rutherford Backscattering Spectrometry (RBS) and Density Functional Theory (DFT) calculations. A new structural model of the Si(112)6 x 1-Ga surface is inferred. It consists of Ga zig-zag chains that are intersected by quasi-periodic vacancy lines or misfit dislocations. The experimentally observed meandering of the vacancy lines is caused by the co-existence of competing 6 x 1 and 5 x 1 unit cells and by the orientational disorder of symmetry breaking Si-Ga dimers inside the vacancy lines. The Ga atoms are fully coordinated, and the surface is chemically passivated. STS data reveal a semiconducting surface and show excellent agreement with calculated Local Density of States (LDOS) and STS curves. The energy gain obtained by fully passivating the surface calls the idea of step-edge decoration as a viable growth method toward 1D metallic structures into question.Comment: Submitted, 13 pages, accepted in Phys. Rev. B, notational change in Fig.