Water‐soluble 17 and 23 kDa polypeptides restore oxygen evolution activity by creating a high‐affinity binding site for Ca2+ on the oxidizing side of Photosystem II

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117036/1/feb20014579384813939.pd

In photosynthesis, oxygen comes from water: from a 1787 book for women by Monsieur De Fourcroy

Abstract It is now well established that the source of oxygen in photosynthesis is water. The earliest suggestion previously known to us had come from René Bernard Wurmser (1930). Here, we highlight an earlier report by Monsieur De Fourcroy (1787), who had already discussed the broad outlines of such a hypothesis in a book on Chemistry written for women. We present here a free translation of a passage from this book, with the original text in French as an Appendix

The Relationships among Trait Anxiety, State Anxiety and the Goal Performance of Penalty Shoot-Out by University Soccer Players

The present study examined how the level of trait anxiety, which is a personality characteristic, influences state anxiety and penalty shoot-out performance under pressure by instruction. The high and low trait anxiety groups were selected by using Spielberger's Trait Anxiety Scale, with trait anxiety scores, and control and pressure conditions manipulated by instructions. The participants were two groups of eight university male soccer players. They individually performed 20 shots from the penalty shoot-out point, aiming at the top right and top left corner areas in the soccer goal. Each condition had 10 trials in a within-subject design. The dependent measures comprised the number of successful goals and the state anxiety scores under each instructional condition. The result showed a significant main effect of instruction. State anxiety scores increased more and the number of successful goals decreased more in high trait anxiety groups than in low trait anxiety groups under pressure instructional condition. These findings suggest that players with higher trait anxiety scores tend to experience increased state anxiety under a pressure-laden condition, and higher state anxiety interferes with goal performance

2000 Ohio-Grape Wine Short Course

Air, water, sun, and fire--the cooper's footprint on the barrel / Henry Work -- Keeping the bugs unhappy; successful barrel sanitation and maintenance / Henry Work -- Recommended methods for cleaning and maintaining oak cooperage / Phil Burton and Henry Work, with Jim Yerkes -- Chip me, stave me, oak me! The romance, dollars and sense of barrel alternatives / Tim DiPlacido -- Oak experiments / Roland Riesen -- Barrel experiment / Nick Ferrante -- Exploring the versatility and potential of vidal / Roland Riesen -- Ferrante: 1999 vineyard planting / Nick Ferrante -- Breeding rootstocks for current and impending viticultural problems / Andrew Walker -- Grape expectations looking toward traditional and non-traditional sponsors to enhance your event / Doniella Winchell -- Assessing grape maturity by taste and by numbers / Thomas Henick-Kling -- Influence of fruit condition on wine quality / James F. Gallander -- Influence of post bottling storage temperature and SO2 on wine quality / T. E. Steiner -- What we do at harvest to help wine quality / Tony Debevc -- Delivering wine quality / Nick Ferrante -- Criteria for selecting rootstocks / Andrew Walker -- A comparison of Pinot noir production in New York and Burgundy / Pascal Durand and Leslie Weston -- A unique approach to harvest labor / Fran Massaro -- New fungicide registrations for grapes in the year 2000 / Michael Ellis -- Studies to determine time of susceptibility of grape berry and rachis tissues to infection by Phomopsis viticola / O. Erincik, L. V. Madden, D. C. Ferree and M. A. Ellis -- Rootstock performance in Ohio / Arnie Esterer -- Growing your own: vinifera grafting experiments (1999) / Ron Barrett -- Developing an effective fungicide spray program for wine grapes in Ohio / Michael Ellis -- Light and fruit set / David C. Ferree, David M. Scurlock and John C. Schmid -- Soil amendments and mulches in tree health management / Harry Hoitink, Matthew Krause and Randy Zondag -- Report of 5th International Symposium on Cool Climate Viticulture and Enology / Roland Riesen -- Control strategies for soil insects in the vineyard / Roger Williams and Dan Fickl

Mn 2+ reduces Y z + in manganese-depleted Photosystem II preparations

Manganese in the oxygen-evolving complex is a physiological electron donor to Photosystem II. PS II depleted of manganese may oxidize exogenous reductants including benzidine and Mn 2+ . Using flash photolysis with electron spin resonance detection, we examined the room-temperature reaction kinetics of these reductants with Y z + , the tyrosine radical formed in PS II membranes under illumination. Kinetics were measured with membranes that did or did not contain the 33 kDa extrinsic polypeptide of PS II, whose presence had no effect on the reaction kinetics with either reductant. The rate of Y z + reduction by benzidine was a linear function of benzidine concentration. The rate of Y z + reduction by Mn 2+ at pH 6 increased linearly at low Mn 2+ concentrations and reached a maximum at the Mn 2+ concentrations equal to several times the reaction center concentration. The rate was inhibited by K + , Ca 2+ and Mg 2+ . These data are described by a model in which negative charge on the membrane causes a local increase in the cation concentration. The rate of Y z + reduction at pH 7.5 was biphasic with a fast 400 μs phase that suggests binding of Mn 2+ near Y z + at a site that may be one of the native manganese binding sites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43534/1/11120_2004_Article_BF00048306.pd

Transfer entropy—a model-free measure of effective connectivity for the neurosciences

Understanding causal relationships, or effective connectivity, between parts of the brain is of utmost importance because a large part of the brain’s activity is thought to be internally generated and, hence, quantifying stimulus response relationships alone does not fully describe brain dynamics. Past efforts to determine effective connectivity mostly relied on model based approaches such as Granger causality or dynamic causal modeling. Transfer entropy (TE) is an alternative measure of effective connectivity based on information theory. TE does not require a model of the interaction and is inherently non-linear. We investigated the applicability of TE as a metric in a test for effective connectivity to electrophysiological data based on simulations and magnetoencephalography (MEG) recordings in a simple motor task. In particular, we demonstrate that TE improved the detectability of effective connectivity for non-linear interactions, and for sensor level MEG signals where linear methods are hampered by signal-cross-talk due to volume conduction

Effects of aversive odour presentation on inhibitory control in the Stroop colour-word interference task

<p>Abstract</p> <p>Background</p> <p>Due to the unique neural projections of the olfactory system, odours have the ability to directly influence affective processes. Furthermore, it has been shown that emotional states can influence various non-emotional cognitive tasks, such as memory and planning. However, the link between emotional and cognitive processes is still not fully understood. The present study used the olfactory pathway to induce a negative emotional state in humans to investigate its effect on inhibitory control performance in a standard, single-trial manual Stroop colour-word interference task. An unpleasant (H₂S) and an emotionally neutral (Eugenol) odorant were presented in two separate experimental runs, both in blocks alternating with ambient air, to 25 healthy volunteers, while they performed the cognitive task.</p> <p>Results</p> <p>Presentation of the unpleasant odorant reduced Stroop interference by reducing the reaction times for incongruent stimuli, while the presentation of the neutral odorant had no effect on task performance.</p> <p>Conclusions</p> <p>The odour-induced negative emotional state appears to facilitate cognitive processing in the task used in the present study, possibly by increasing the amount of cognitive control that is being exerted. This stands in contrast to other findings that showed impaired cognitive performance under odour-induced negative emotional states, but is consistent with models of mood-congruent processing.</p