Cultural practices in networked classroom learning environments

This paper presents results of a case study conducted in secondary mathematics classrooms using a new generation of networked classroom technology (Participatory Simulations). Potential for drawing on youths’ cultural practices in networked learning environments is explored in terms of opportunities for traditionally underserved students to participate in powerful mathematical discourse and practice. As mediated by the networked technology, the multiple modes of participation and opportunities to contribute to the group’s accomplishment of its task served as important avenues for underserved students to bring to bear resources they develop through participating in everyday practices of their communities. The goal is to provide examples of networked activities’ potential for leveraging cultural practices of marginalized groups through pedagogy that invites youth to draw on linguistic resources and interaction patterns they develop as members of cultural groups.

Measuring team situation awareness in decentralized command and control environments

Decentralized command and control settings like those found in the military are rife with complexity and change. These settings typically involve dozens, if not hundreds to thousands, of heterogeneous players coordinating in a distributed fashion in a dynamically networked battlefield laden with sensor data, intelligence reports, communications, and plans emanating from many different perspectives. Consider the concept of team situation awareness in this setting. What does it mean for a team to be aware of a situation or, more importantly, of a critical change in a situation? Is it sufficient or necessary for all individuals on the team to be independently aware? Or is there some more holistic awareness that emerges as team members interact? We re-examine the concept of team situation awareness in decentralized systems beyond an individual-oriented knowledge-based construct by considering it as a team interaction-based phenomenon. A theoretical framework for a process-based measure called 'coordinated awareness of situations by teams' is outlined.     

Successful preparation and analysis of a 5-site 2-variable DNA library

DNA code sequences generated by the program SynDCode were used to construct a 5-site, 2-variable computational DNA library by parallel overlap self-assembly. The final library was amplified using the polymerase chain reaction (PCR) to obtain a fragment of the expected size. Twelve library sequences randomly selected from the library by cloning were sequenced and found to be distinct and correctly assembled library strands. A Birthday Problem-like analysis suggests that we have all 32 different molecules in our library mixture. We then developed new protocols using DNA hybridization to successfully identify single members of this library. We have also used this protocol to analyze mixtures of clones from the library. This approach shows the experimental validation of the ability to distinguish different sequences generated from the SynDCode program. We are in the process of working out protocols to separate out specific library members and to expand this library.     

Verification of the randomized consensus algorithm of Aspnes and Herlihy: a case study

Summary. The Probabilistic I/O Automaton model of [31] is used as the basis for a formal presentation and proof of the randomized consensus algorithm of Aspnes and Herlihy. The algorithm guarantees termination within expected polynomial time. The Aspnes-Herlihy algorithm is a rather complex algorithm. Processes move through a succession of asynchronous rounds, attempting to agree at each round. At each round, the agreement attempt involves a distributed random walk. The algorithm is hard to analyze because of its use of nontrivial results of probability theory (specifically, random walk theory which is based on infinitely many coin flips rather than on finitely many coin flips), because of its complex setting, including asynchrony and both nondeterministic and probabilistic choice, and because of the interplay among several different sub-protocols. We formalize the Aspnes-Herlihy algorithm using probabilistic I/O automata. In doing so, we decompose it formally into three subprotocols: one to carry out the agreement attempts, one to conduct the random walks, and one to implement a shared counter needed by the random walks. Properties of all three subprotocols are proved separately, and combined using general results about automaton composition. It turns out that most of the work involves proving non-probabilistic properties (invariants, simulation mappings, non-probabilistic progress properties, etc.). The probabilistic reasoning is isolated to a few small sections of the proof. The task of carrying out this proof has led us to develop several general proof techniques for probabilistic I/O automata. These include ways to combine expectations for different complexity measures, to compose expected complexity properties, to convert probabilistic claims to deterministic claims, to use abstraction mappings to prove probabilistic properties, and to apply random walk theory in a distributed computational setting. We apply all of these techniques to analyze the expected complexity of the algorithm. Received: February 1999 / Accepted: March 2000     

Information systems strategies in knowledge-based SMEs: the role of core competencies

Research into the sources of competitive advantage identifies two competing views. The first concerns industry structure, and the role of information systems (IS) in enabling competitive advantage is to lower cost, build barriers to entry and tie in customers and suppliers. The second view is resource-based. This argues that competitive advantage arises from the ability to accumulate resources and capabilities that are rare, valuable, non-substitutable and difficult to imitate. This paper discusses the role of IS as firm resources and the role of such resources in small firms (SMEs). It uses as a vehicle, the identification and development of an information systems strategy (ISS) in a knowledge-based SME. The use of core competencies or capabilities, a key aspect of resources, as a basis for an ISS is contrasted with the use of a structural approach exemplified here by the value chain. Using participant observation research in a not-for-profit organisation that provides consultancy in social housing, this paper investigates these approaches. The paper concludes by identifying a number of areas for further research including the operationalisation of the core competence perspective in developing an ISS.     

Referential Communication Disturbances in the Speech of Nonschizophrenic Siblings of Schizophrenia Patients.

Several different types of communication disturbances have been identified in the speech of schizophrenia patients. This study assessed 6 types of referential communication disturbances in the speech of 32 stable outpatients, 23 of their nonschizophrenic siblings, and 27 control subjects. The siblings made more frequent reference failures of all types than control subjects and did not differ from the patients on most types of disturbance. Only on the arguably most "schizophrenic" type of disturbance, the missing information reference, did patients show more deviance than siblings. On the vague reference, siblings showed more deviance than patients. These results, which are very similar to those previously reported on parents of patients, support the idea that referential disturbances reflect vulnerability to schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Does Class Size in First Grade Relate to Children's Academic and Social Performance or Observed Classroom Processes?

This study evaluated the extent to which first-grade class size predicted child outcomes and observed classroom processes for 651 children (in separate classrooms). Analyses examined observed child-adult ratios and teacher-reported class sizes. Smaller classrooms showed higher quality instructional and emotional support, although children were somewhat less likely to be engaged. Teachers in smaller classes rated typical children in those classes as more socially skilled and as showing less externalizing behavior and reported more closeness toward them. Children in smaller classes performed better on literacy skills. Larger classrooms showed more group activities directed by the teacher, teachers and children interacted more often, and children were more often engaged. Lower class sizes were not of more benefit (or harm) as a function of the child's family income. First-grade class size in the range typical of present-day classrooms in the United States predicts classroom social and instructional processes as well as relative changes in social and literacy outcomes from kindergarten to first grade. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working Models of Attachment Shape Perceptions of Social Support: Evidence From Experimental and Observational Studies.

Two studies examined the association between attachment style and perceptions of social support. Study 1 (N = 95 couples) used an experimental paradigm to manipulate social support in the context of a stressful task. Insecure participants (anxious and avoidant) who received low-support messages appraised these messages more negatively, rated a prior behavioral interaction with their partner as having been less supportive, and performed significantly worse at their task compared with secure participants. Study 2 (N = 153 couples) used a similar paradigm except that partners were allowed to send genuine support messages. Insecure participants (especially fearful) perceived their partners' messages as less supportive, even after controlling for independent ratings of the messages and relationship-specific expectations. These studies provide evidence that individuals are predisposed to appraise their support experiences in ways that are consistent with their chronic working models of attachment, especially when the support message is ambiguous. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gamma oscillations and stimulus selection

More coherent excitatory stimuli are known to have a competitive advantage over less coherent ones. We show here that this advantage is amplified greatly when the target includes inhibitory interneurons acting via GABA(A)-receptor-mediated synapses and the coherent input oscillates at gamma frequency. We hypothesize that therein lies, at least in part, the functional significance of the experimentally observed link between attentional biasing of stimulus competition and gamma frequency rhythmicity.