Effects of face-to-face versus chat communication on performance in a collaborative inquiry modeling task

In many contemporary collaborative inquiry learning environments, chat is being used as a means for communication. Still, it remains an open issue whether chat communication is an appropriate means to support the deep reasoning process students need to perform in such environments. Purpose of the present study was to compare the impact of chat versus face-to-face communication on performance within a collaborative computer-supported modeling task. 44 Students from 11th-grade pre-university education, working in dyads, were observed during modeling. Dyads communicated either face-to-face or through a chat tool. Students’ reasoning during modeling was assessed by analyzing verbal protocols. In addition, we assessed the quality of student-built models. Results show that while model quality scores did not differ across both conditions, students communicating through chat compressed their interactions resulting in less time spent on surface reasoning, whereas students who communicated face-to-face spent significantly more time on surface reasoning.     

Radio‐opaque fecal impaction and pseudo‐occlusion in a dialyzed patient taking lanthanum carbonate

Lanthanum therapy is an efficient therapy of hyperphosphoremia by chelating phosphore in the digestive tract. Lanthanum is a silvery white metallic element that belongs to group 3 of the periodic table. This drug is lightly absorbed and has low water solubility. It should be borne in mind that abdominal X‐rays of patients taking lanthanum carbonate may have a radio‐opaque appearance typical of imaging agents. This characteristic is suggested to confirm adherence of the patient by doing an abdominal X‐ray. We describe in our case a particular good compliant patient with slow digestive transit, which ends by pseudo‐occlusion.     

Iridium complexes incorporating coumarin moiety as catalyst photoinitiators: Towards household green LED bulb and halogen lamp irradiation

Household LED bulbs and halogen lamps are used to promote the ring-opening photopolymerization of epoxides in the presence of a new series of iridium(III) complexes (IrCs) exhibiting enhanced visible light absorption properties through the introduction of a coumarin moiety. These latter complexes are used as catalyst photoinitiators in an oxidative cycle in combination with a silane and an iodonium salt. Remarkably, even under the selected very soft irradiations (e.g. light intensity lower than 2 mW/cm²), excellent polymerization profiles are obtained (conversions > 80%). The mechanisms are investigated by ESR and luminescence experiments.     

Independence and Possibilistic Conditioning

There is not a unique definition of a conditional possibility distribution since the concept of conditioning is complex and many papers have been conducted to define conditioning in a possibilistic framework. In most cases, independence has been also defined and studied by means of a kind of analogy with the probabilistic case. In [2,4], we introduce conditional possibility as a primitive concept by means of a function whose domain is a set of conditional events. In this paper, we define a concept of independence associated with this form of conditional possibility and we show that classical properties required for independence concepts are satisfied.     

Agreement on initial impressions: Differences due to perceivers, trait dimensions, and target behaviors.

Assesses agreement as a function of the trait being judged, the information presented, and individual differences to spontaneously use particular trait dimensions. In Experiment 1, there was a reliable amount of agreement in rating the targets, but this was greater if the traits were related to extraversion (Factor 1 traits) than to intelligence, honesty, or conscientiousness (Factor 2 traits). In Experiment 2, Ss viewed videotapes of interviews in which the questions focused on information relevant to either Factor l or Factor 2 traits. Again there was greater agreement in ratings of Factor 1 than Factor 2 traits, but this difference was reliably reduced if Ss saw the tape that focused on Factor 2 information. Regardless of the tape viewed, Ss who frequently used Factor 2 traits gave ratings on these that were in greater agreement with those of judges as a whole. Ss judged Factor 2 traits as more difficult to clearly confirm. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Coupling coefficients of a distributed execution

We define coupling coefficients of a distributed execution which evaluate the temporal interactions of a distributed execution between the processes during the execution. These coefficients assess the structure of message exchanges rather than the quantity of exchanged information.

The coupling coefficients are easy to compute and provide a criterion to compare and to analyze distributed executions. We check the relevance of our definitions by computing these coefficients for particular cases and by studying their behavior with respect to operators which are defined on the distributed computations. This leads us to establish noteworthy results concerning the behavior of execution times with respect to these operators.

Finally, we regard the coupling coefficients as functions of the relative processor speeds and characterize the executions for which coupling is minimal or maximal.     

Detection and enumeration of Campylobacter jejuni and Campylobacter coli by indirect impedimetry with an oxygen scavenging system

Six strains of Campylobacter jejuni and Campylobacter coli were shown to grow in a variety of media, but, with one exception, they were unable to produce sufficient change in the electrical properties of the medium to allow their detection by impedance monitoring. With the use of an indirect method based on absorption of evolved carbon dioxide and a medium containing the oxygen scavenger Oxyrase, all strains were detectable, and correlations between time to detection and the logarithm of the inoculum level were excellent. The level of interstrain variation was sufficiently low that all data could be consolidated into a single calibration curve (r = 0.987).