Phase-field-crystal model for fcc ordering

We develop and analyze a two-mode phase-field-crystal model to describe fcc ordering. The model is formulated by coupling two different sets of crystal density waves corresponding to and reciprocal lattice vectors, which are chosen to form triads so as to produce a simple free- energy landscape with coexistence of crystal and liquid phases. The feasibility of the approach is demonstrated with numerical examples of polycrystalline and (111) twin growth. We use a two-mode amplitude expansion to characterize analytically the free-energy landscape of the model, identifying parameter ranges where fcc is stable or metastable with respect to bcc. In addition, we derive analytical expressions for the elastic constants for both fcc and bcc. Those expressions show that a non-vanishing amplitude of [200] density waves is essential to obtain mechanically stable fcc crystals with a non-vanishing tetragonal shear modulus (C11 - C12)/2. We determine the model parameters for specific materials by fitting the peak liquid structure factor properties and solid density wave amplitudes following the approach developed for bcc [K.-A. Wu and A. Karma, Phys. Rev. B 76, 184107 (2007)]. This procedure yields reasonable predictions of elastic constants for both bcc Fe and fcc Ni using input parameters from molecular dynamics simulations. The application of the model to two-dimensional square lattices is also briefly examined.Comment: 14 figure

Dissemination of Health Information within Social Networks

In this paper, we investigate, how information about a common food born health hazard, known as Campylobacter, spreads once it was delivered to a random sample of individuals in France. The central question addressed here is how individual characteristics and the various aspects of social network influence the spread of information. A key claim of our paper is that information diffusion processes occur in a patterned network of social ties of heterogeneous actors. Our percolation models show that the characteristics of the recipients of the information matter as much if not more than the characteristics of the sender of the information in deciding whether the information will be transmitted through a particular tie. We also found that at least for this particular advisory, it is not the perceived need of the recipients for the information that matters but their general interest in the topic

Rejoinder to Dominiak’s rejoinder to my rejoinder to his paper on Brain Death

This is a rejoinder to above Dominiak's rejoinder. First and foremost, I am flattered that Dominiak found my rejoinder fit for his rejoinder. As usual, the said author’s incisiveness is literally second to none. Dominiak is rightly distinguished for his almost animal instinct for spotting performative inconsistencies and, alas, surprise-surprise, I was the one who could not escape the said logical fallacy. I am equally delighted to have been welcomed to have my own say in turn and reply with yet another rejoinder, which I am hereby happily and promptly embarking on. On the other hand, being granted the privilege of the last word being on me, I will try to be mild and try to refrain from any ironic overtones. As they say, It’s not in my nature to kick a man when he is down. Therefore, in the order corresponding to Dominiak’s rejoinder, I will try to concede some points to Dominiak and still argue about the ones on which I still remain unconvinced

Economic Behaviors of Street Vendors in Makassar Traditional Markets

Abstract: This paper aims to explore the considerations behind the economic behavior of street vendors in traditional markets at Makassar, by employing qualitative research design. Data were collected through a semi-structured interview to 23 participants, who were recruited through purposive sampling technique. The results suggested that the street vendors were still categorized into the traditional economic subsystem behavior, in which the distribution of goods is still done directly, simple, and traditional, both in supply and demand. Profit maximisation and utilisation were done under the priority scale through several personal and cultural considerations over economic-rational considerations, whereas networking development was exclusively conducted on their own close environment (family, fellow merchants, costumers, and the local suppliers). Key words: Economic behavior, street vendors, traditional market, Indonesi

The main principles of family reunification in the jurisprudence of the ECtHR

Family reunification is regulated directly or indirectly by several international legal instruments at universal and regional level. On regional level the Council of Europe’s documents and several conventions give general directions to the contracting states. The European Court of Human Rights was established by virtue of the European Convention of Human Rights, and has only jurisdiction with regard to the interpretation and application of the Convention and the Protocols, it is limited to its interpretation of the Convention and its case-law. Member States of the Council of Europe are obliged to respect the human rights of the Convention with regard to everyone within their jurisdiction, to ensure that all rights laid down in the Convention are respected and accessible on its territory. Parallel to this, Member States have margin of appreciation to interpret and implement the Convention. The paper aims to build a frame around the main principles of family reunification through the jurisdiction of the European Court of Human Rights

Change or control? Developing dialogues between research and public protection

This paper aims to scope out some of the implications of desistance research for the community management of high risk offenders. Acknowledging the limited empirical research exploring this interface, this paper outlines the evolving evidence base and what this tells us about the process of desistance and what supports it. The evidence as to whether 'high risk offenders' desist and what we know about this process is discussed prior to outlining the landscape of current and principal practice approaches which can be located in the community/public protection model. Potential dialogues between desistance research and public protection practices are discussed to explore ensuing implications and opportunities for practice

The Interactions of Relationships, Interest, and Self-Efficacy in Undergraduate Physics

This collected papers dissertation explores students’ academic interactions in an active learning, introductory physics settings as they relate to the development of physics self-efficacy and interest. The motivation for this work extends from the national call to increase participation of students in the pursuit of science, technology, engineering, and mathematics (STEM) careers. Self-efficacy and interest are factors that play prominent roles in popular, evidence-based, career theories, including the Social cognitive career theory (SCCT) and the identity framework. Understanding how these constructs develop in light of the most pervasive characteristic of the active learning introductory physics classroom (i.e., peer-to-peer interactions) has implications on how students learn in a variety of introductory STEM classrooms and settings structured after constructivist and sociocultural learning theories. I collected data related to students’ in-class interactions using the tools of social network analysis (SNA). Social network analysis has recently been shown to be an effective and useful way to examine the structure of student relationships that develop in and out of STEM classrooms. This set of studies furthers the implementation of SNA as a tool to examine self-efficacy and interest formation in the active learning physics classroom. Here I represent a variety of statistical applications of SNA, including bootstrapped linear regression (Chapter 2), structural equation modeling (Chapter 3), and hierarchical linear modeling for longitudinal analyses (Chapter 4). Self-efficacy data were collected using the Sources of Self-Efficacy for Science Courses – Physics survey (SOSESC-P), and interest data were collected using the physics identity survey. Data for these studies came from the Modeling Instruction sections of Introductory Physics with Calculus offered at Florida International University in the fall of 2014 and 2015. Analyses support the idea that students’ perceptions of one another impact the development of their social network centrality, which in turn affects their self-efficacy building experiences and their overall self-efficacy. It was shown that unlike career theories that emphasize causal relationships between the development of self-efficacy and the subsequent growth of student interest, in this context student interest takes precedence before the development of student self-efficacy. This outcome also has various implications for career theories

Exploring the Effects of Network Dynamics on Student Test Scores in a Rural Middle School

The purpose of the study was to explore network dynamics within a rural middle school and identify to what extent middle school faculty engagement in network dynamics affects student test scores. Specifically, within the study, I examined the effects of network relationships (i.e., trust and social ties), content exchange (i.e., advice ties), and student context on students’ Measures of Academic Progress (MAP) test scores for Fall, Spring, and Growth. A survey was sent to 75 faculty and staff members in a rural middle school of 740 students. Network analysis by means of the ORA software toolkit, along with hierarchical linear modeling, were used for data analysis. I found that teachers’ trust, social, and advice ties were significant predictors of student achievement on MAP math, MAP reading, and MAP language test scores. Student context impacted student performance and was controlled for subsequent steps in the analysis. In the faculty level analysis, I found trust and social ties to be significant predictors of student performance in the Fall; social and advice ties significant predictors of student performance in the Spring; and trust and advice ties significant predictors of Growth. The study identifies the specific trust, social, and advice ties that affect students’ MAP test scores. Implications for practice and research are discussed

The potential of mixed-method social network analysis for studying interaction between agency and structure in education

This article discusses the potential of mixed-method social network analysis (MMSNA) as a methodology for designing and conducting studies that address questions of interplay between human agency and social structures in educational settings. First, we discuss a rationale for using MMSNA referring to the theoretical calls for better understanding the role of agency in network structures. Next, we discuss examples of studies that illustrate how MMSNA has been applied to investigate (a) the role of agency in social network formation and (b) how social networks facilitate actors' agency in educational processes. Finally, we outline a guide for how to use MMSNA and consider its potential for future studies of interactions between agency and structures in educational settings