Skill level changes the coordination and variability of standing posture and movement in a pistol-aiming task

The study investigated the coordination and variability of posture and pistol motion for skilled pistol shooters and novices in a pistol-aiming task. The participants stood on a force platform and held a pistol with the preferred arm to aim for accuracy to a target on 30 s trials. The results revealed that the amount of the centre of pressure (COP) and pistol motion was lower for the expert than novice group. The time–varying structure of COP as indexed by multiscale entropy (MSE) and detrended fluctuation analysis (DFA) was also lower for the expert than the novice group. The relative phase between the COP in the anterior–posterior (AP) and pistol in the AP and between the COP in the medial–lateral (ML) and pistol in AP was close to inphase for the both groups. However, for the novice group the coordination patterns of posture and pistol motion were more variable with the pistol motion leading the posture motion while it was lagging in the skilled group. The findings show different qualitative and quantitative dynamics in pistol-aiming as a function of skill level with postural control foundational to supporting the reduced dispersion and complexity of the skilled arm-pistol motion.     

Diversity research in the United States Navy: An update

Researchers at the Navy Personnel Research and Development Center (NPRDC) have investigated issues related to gender, racial, and ethnic diversity for over two decades. Rosenfeld, M.D. Thomas, Edwards, P.J. Thomas, and E.D. Thomas (1991) provided a comprehensive review of NPRDC diversity research conducted between 1970 and 1990. This article examines NPRDC diversity research conducted during the past 5 years and identifies future research issues. The present review is divided into four major topic areas and a final section of conclusions and future directions. The first section describes the Navywide and unit-specific programs to assess equal opportunity climate and sexual harassment. The second section summarizes research pertaining to issues raised by women's changing roles and their increased participation in the Navy. In the third section, the findings of Navy discipline studies shed light on the issue of higher disciplinary rates among minority personnel. Research on Hispanics is reviewed in the fourth section. Finally, in the Discussion and Conclusions section, potential future research emphases are identified.     

喧嚣之后,网络公开课何去何从?

人们首次听说"网络公开课"(Massive Open Online Courses)的名字是在本世纪初。从2001年起,耶鲁、剑桥、麻省理工学院等一批世界顶尖高校纷纷将自己的课程公布到网上。如此"慷慨"的知识共享不光让世界各地的学生近距离地领略到国外名校教授的人文内涵与学术魅力,更是掀起了教育史上继远程函授之后的又一次革命。本文从商业中的"颠覆性创新"角度出发,另类解读网络公开课的现状与未来。     

The information practices and politics of migrant-aid work in the US-Mexico borderlands

Abstract

Numerous organizations work to provide humanitarian aid to undocumented migrants along the US-Mexico border—from running shelters in Mexico to placing water on migratory trails. Resistance to information-sharing between organizations (and to the public), especially through technologically mediated means, is common. However, some organizers and volunteers work across organizational boundaries and share information informally. Information secrecy is often justified by concerns that law enforcement authorities or anti-immigration activists might gain access to information, allowing them to harm, detain or remove migrants, or interfere with humanitarian work. The choices made about the collection and (non)disclosure of information are manifestations of what we call “liminal” information practices: such behaviors are unique to humanitarian volunteers working in the gray, ethical area between law enforcement and humanitarian values and action, and they are guided by the information politics at play within this context.     

Software for calculating blood lactate endurance markers

Abstract

Blood lactate markers are used as summary measures of the underlying model of an athlete's blood lactate response to increasing work rate. Exercise physiologists use these endurance markers, typically corresponding to a work rate in the region of high curvature in the lactate curve, to predict and compare endurance ability. A short theoretical background of the commonly used markers is given and algorithms provided for their calculation. To date, no free software exists that allows the sports scientist to calculate these markers. In this paper, software is introduced for precisely this purpose that will calculate a variety of lactate markers for an individual athlete, an athlete at different instants (e.g. across a season), and simultaneously for a squad.     

Paradoxes of Press Freedom in Colonial West Africa

This article describes the shifts and contradictions in British approaches to the control of print media in colonial West Africa between the 1920s and 1940s. Well before the Colonial Office's post-war interventions to create an ‘enlightened and educated’ West African citizenry through mass education, decades of independent newspaper production in the region helped to shape independent and critical readerships. For the British, however, an upsurge in African nationalist journalism in the mid-1930s coincided with a perceived Communist infiltration of ‘British West Africa’ to make censorship and surveillance more palatable than before to colonial officials in London, in spite of the new emphasis on public relations.     

From PSAs to reel communities: exploring the sounds and silences of urban youth mobilizing digital media production

ABSTRACT

Amplified by a global political climate of fear, oppression, and increased nationalism, this article examines how U.S. secondary students in a digital media elective course used multimodal composition, and video production in particular, as a nexus of ‘participatory politics.’ By partnering theories of multiliterate expression with youth civic engagement, it offers new understandings into how urban youth use digital media production to leverage school-based social action. Refracted through a mediated discourse analysis lens, and with a particular focus on sound as a modal resource for design, findings suggest that youth used media production and semiotic sense-making to simultaneously enliven community action as well as shield students from personal histories of trauma. By engaging in the process of digital media production, as this article suggests, students cultivated new core practices of civic interaction and local engagement by amplifying injustice.