The haunted delimitation of subjectivity in the Work of Nicolas Abraham

Kinesin-like calmodulin binding protein (KCBP), a Kinesin-14 family motor protein, is involved in the structural organization of microtubules during mitosis and trichome morphogenesis in plants. The molecular mechanism of microtubule bundling by KCBP remains unknown. KCBP binding to microtubules is regulated by Ca(2+)-binding proteins that recognize its C-terminal regulatory domain. In this work, we have discovered a new function of the regulatory domain. We present a crystal structure of an Arabidopsis KCBP fragment showing that the C-terminal regulatory domain forms a dimerization interface for KCBP. This dimerization site is distinct from the dimerization interface within the N-terminal domain. Side chains of hydrophobic residues of the calmodulin binding helix of the regulatory domain form the C-terminal dimerization interface. Biochemical experiments show that another segment of the regulatory domain located beyond the dimerization interface, its negatively charged coil, is unexpectedly and absolutely required to stabilize the dimers. The strong microtubule bundling properties of KCBP are unaffected by deletion of the C-terminal regulatory domain. The slow minus-end directed motility of KCBP is also unchanged in vitro. Although the C-terminal domain is not essential for microtubule bundling, we suggest that KCBP may use its two independent dimerization interfaces to support different types of bundled microtubule structures in cells. Two distinct dimerization sites may provide a mechanism for microtubule rearrangement in response to Ca(2+) signaling since Ca(2+)- binding proteins can disengage KCBP dimers dependent on its C-terminal dimerization interface

Quantifying the Performance of Individual Players in a Team Activity

Teamwork is a fundamental aspect of many human activities, from business to art and from sports to science. Recent research suggest that team work is of crucial importance to cutting-edge scientific research, but little is known about how teamwork leads to greater creativity. Indeed, for many team activities, it is not even clear how to assign credit to individual team members. Remarkably, at least in the context of sports, there is usually a broad consensus on who are the top performers and on what qualifies as an outstanding performance.In order to determine how individual features can be quantified, and as a test bed for other team-based human activities, we analyze the performance of players in the European Cup 2008 soccer tournament. We develop a network approach that provides a powerful quantification of the contributions of individual players and of overall team performance.We hypothesize that generalizations of our approach could be useful in other contexts where quantification of the contributions of individual team members is important

Sensitivity and specificity of the flow centrality metric.

<p>(A) For every distinct value of in our data, we calculate the fraction of values of in the groups “Win” and “Not Win”. The area under the curve (AUC) statistic provides a measure of the sensitivity-specificity of the quantity under consideration <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010937#pone.0010937-Fawcett1" target="_blank">[12]</a>. Values of AUC close to 1 indicate high sensitivity with high specificity. We find an AUC of 0.825, much larger than the values expect by chance at the 90% confidence interval (shown in gray), which vary between 0.319 and 0.652. (B) Number of matches where the team with highest performance wins, ties, or loses as a function of . For the 20 matches where the difference is greater than 0.75, the team with the highest performance won 15 times, tied 2 and lost 3. This means that for the odds of the team of highest performance winning the match are 3∶1. (C) AUC statistic as a function of in for “win” versus “Loss” outcomes. The highest AUC value is achieved for .</p

Best team performances.

<p>The ranking is in agreement with expert evaluations of the performance of the different teams. Note that all six matches played by Spain are in the top ten. The average performance of the opponents of a team provides a measure of defensive effectiveness. Note that Spain was able not only to perform very well but also to force its opponents to perform poorly, whereas Russia, for example, performed well but was unable to limit the play of its opponents.</p

Time evolution of the performance of players and teams.

<p>(A) Xavi Hernandez, the MVP of the tournament, played extraordinarily well in the first match and in the tournament's final. The performance of Michael Ballack, the German team captain, is closely aligned with the performance of his team; as his performance slips in the knockout phase (games 4 to 6), Germany's performance also deteriorates. (B) Most teams performed at nearly constant levels during the first three matches of the tournament. In fact, the performance of a team during the first three matches was, for Euro 2008, a good predictor of the likelihood of a team winning the tournament.</p

Best individual performances.

<p>Xavi Hernandez, who was named the tournament's MVP because of his performance in Spain's first match and the tournament final, and Sergio Ramos were lauded broadly for their performances. Spanish, Dutch and Portuguese players dominate both lists, in agreement with the consensus of many soccer analysts who identified these teams as the ones that played the best soccer. Indeed, a large number of the players on the list (marked with *) also appear in the “Team of the tournament” selected by the UEFA Technical Team.</p

Visualization of the three knockout-phase matches of the Spanish team.

<p>Node position is determined by the player's field position and node number refers to the player's jersey number. Nodes are color-coded by the z-score of the passing accuracy of the player, and sized according to the player's performance. The width of the arcs grows exponentially with the number of passes successfully completed between two players, whereas the color indicates the normalized arc flow centrality. This representation of the “flow networks” allows us to encode a large amount of individual and team performance features enabling an observer to learn many aspects of a team's play.</p

Plant Kinesin-Like Calmodulin Binding Protein Employs Its Regulatory Domain for Dimerization.

Kinesin-like calmodulin binding protein (KCBP), a Kinesin-14 family motor protein, is involved in the structural organization of microtubules during mitosis and trichome morphogenesis in plants. The molecular mechanism of microtubule bundling by KCBP remains unknown. KCBP binding to microtubules is regulated by Ca(2+)-binding proteins that recognize its C-terminal regulatory domain. In this work, we have discovered a new function of the regulatory domain. We present a crystal structure of an Arabidopsis KCBP fragment showing that the C-terminal regulatory domain forms a dimerization interface for KCBP. This dimerization site is distinct from the dimerization interface within the N-terminal domain. Side chains of hydrophobic residues of the calmodulin binding helix of the regulatory domain form the C-terminal dimerization interface. Biochemical experiments show that another segment of the regulatory domain located beyond the dimerization interface, its negatively charged coil, is unexpectedly and absolutely required to stabilize the dimers. The strong microtubule bundling properties of KCBP are unaffected by deletion of the C-terminal regulatory domain. The slow minus-end directed motility of KCBP is also unchanged in vitro. Although the C-terminal domain is not essential for microtubule bundling, we suggest that KCBP may use its two independent dimerization interfaces to support different types of bundled microtubule structures in cells. Two distinct dimerization sites may provide a mechanism for microtubule rearrangement in response to Ca(2+) signaling since Ca(2+)- binding proteins can disengage KCBP dimers dependent on its C-terminal dimerization interface