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Distances Increase (distance + increase)
Selected AbstractsIndividual Differences in Approach and Avoidance Movements: How the Avoidance Motive Influences Response ForceJOURNAL OF PERSONALITY, Issue 4 2006Rosa Maria Puca ABSTRACT The present research is based on the assumption that people differ in their responsiveness to incentives and threats. In two experiments we examined whether the trait corresponding to the responsiveness to threats (avoidance motive) and the trait corresponding to the responsiveness to incentives (approach motive) influence voluntary motor behavior toward or away from stimuli. In Experiment 1, stimuli consisted of positive and negative words within a lexical decision task. Participants moved their arms backward in order to withdraw from the stimuli or forward in order to approach them. In Experiment 2, participants responded with forward or backward arm movements to neutral sounds coming from behind or in front of them. The main dependent variable was the strength of the approach and avoidance movements. In both experiments this variable was related to participants' avoidance-motive disposition but not to their approach-motive disposition. Avoidance-motivated individuals generally showed more forceful avoidance movements than approach movements. There was no effect of stimulus valence on the strength of the movements in Experiment 1. Furthermore, the results of Experiment 2 suggest that it is not the physical direction (forward or backward) but rather the movement's effect of distance reduction (approach) or distance increase (avoidance) in regard to the stimulus that defines a movement as an approach or an avoidance movement. [source] Strategy for selecting and characterizing linker peptides for CBM9-tagged fusion proteins expressed in Escherichia coliBIOTECHNOLOGY & BIOENGINEERING, Issue 3 2007Mojgan Kavoosi Abstract The influence of linker design on fusion protein production and performance was evaluated when a family 9 carbohydrate-binding module (CBM9) serves as the affinity tag for recombinant proteins expressed in Escherichia coli. Two bioinformatic strategies for linker design were applied: the first identifies naturally occurring linkers within the proteome of the host organism, the second involves screening peptidases and their known specificities using the bioinformatics software MEROPSÔ to design an artificial linker resistant to proteolysis within the host. Linkers designed using these strategies were compared against traditional poly-glycine linkers. Although widely used, glycine-rich linkers were found by tandem MS data to be susceptible to hydrolysis by E. coli peptidases. The natural (PT)xP and MEROPSÔ-designed S3N10 linkers were significantly more stable, indicating both strategies provide a useful approach to linker design. Factor Xa processing of the fusion proteins depended strongly on linker chemistry, with poly(G) and S3N10 linkers showing the fastest cleavage rates. Luminescence resonance energy transfer studies, used to measure average distance of separation between GFP and Tb(III) bound to a strong calcium-binding site of CBM9, revealed that, for a given linker chemistry, the separation distance increases with increasing linker length. This increase was particularly large for poly(G) linkers, suggesting that this linker chemistry adopts a hydrated, extended configuration that makes it particularly susceptible to proteolysis. Differential scanning calorimetry studies on the PT linker series showed that fusion of CBM9 to GFP did not alter the Tm of GFP but did result in a destabilization, as seen by both a decrease in Tm and ,Hcal, of CBM9. The degree of destabilization increased with decreasing length of the (PT)xP linker such that ,Tm,=,,8.4°C for the single P linker. Biotechnol. Bioeng. 2007;98: 599,610. © 2007 Wiley Periodicals, Inc. [source] Growth and single-crystal refinement of phase-III potassium nitrate, KNO3ACTA CRYSTALLOGRAPHICA SECTION B, Issue 6 2009Evelyn J. Freney Oriented single crystals of the high-temperature phase of KNO3 (phase III), a ferroelectric compound that may also occur as an atmospheric aerosol particle, were grown at room temperature and pressure by atomizing a solution of KNO3 in water and allowing droplets to dry on a glass substrate. The crystals are up to 1,mm across and are stable unless mechanically disturbed. There is no evidence of the spontaneous transformation of phase III to the room-temperature stable phase (phase II), even after several months. Single-crystal structure determinations of phase III were obtained at 295 and 123,K. The unit cell regained its room-temperature dimensions after warming from 123,K. The phase-III KNO3 structure can be viewed as the stacking parallel to the c axis of alternating K atoms and planar NO3 groups. The NO3 groups connect the planes of K atoms, where each O is fourfold coordinated to one N and three K. Each K atom has nine O nearest neighbors, with three bonds at 2.813 and six at 2.9092,Å. The interatomic K,N,K distance alternates from 5.051 to 3.941 along the c axis. The N,O distances increase from 1.245,(2),Å at 295,K to 1.2533,(15),Å at 123,K. The nitrate group has a slight non-planarity, with the N atoms 0.011,Å above the O plane and directed toward the more distant K of the K,N,K chain. [source] Wind dispersal in freshwater wetlands: Knowledge for conservation and restorationAPPLIED VEGETATION SCIENCE, Issue 2 2006Merel B. Soons van der Meijden (1990) for taxa; Schaminée et al. (1995; 1996) and Stortelder et al. (1999) for syntaxa Abstract Questions: For wetland plants, dispersal by wind is often overlooked because dispersal by water is generally assumed to be the key dispersal process. This literature review addresses the role of seed dispersal by wind in wetlands. Why is wind dispersal relevant in wetlands? Which seeds are dispersed by wind and how far? And how can our understanding of wind dispersal be applied to wetland conservation and restoration? Methods: Literature review. Results and conclusions: Wind is a widely available seed dispersal vector in wetlands and can transport many seeds over long distances. Unlike water, wind can transport seeds in all directions and is therefore important for dispersal to upstream wetlands and to wetlands not connected by surface water flows. Wind dispersal transports seeds to a wider range of sites than water, and therefore reaches more sites but with lower seed densities. Many wetland plant species have adaptations to facilitate wind dispersal. Dispersal distances increase with decreasing falling velocity of seeds, increasing seed release height and selective release mechanisms. Depending on the adaptations, seeds may be dispersed by wind over many km or only a few m. The frequency of long-distance wind dispersal events depends on these adaptations, the number of produced seeds, the structure of the surrounding vegetation, and the frequency of occurrence of suitable weather conditions. Humans reduce the frequency of successful long-distance wind dispersal events in wetlands through wetland loss and fragmentation (which reduce the number and quality of seeds) and eutrophication (which changes the structure of the vegetation so that seed release into the wind flow becomes more difficult). This is yet another reason to focus on wetland conservation and restoration measures at increased population sizes, prevention of eutrophication, and the restoration of sites at short distances from seed sources. [source] Sterically Crowded peri -Substituted Naphthalene Phosphines and their PV DerivativesCHEMISTRY - A EUROPEAN JOURNAL, Issue 25 2010Fergus Abstract Three sterically crowded peri -substituted naphthalene phosphines, Nap[PPh2][ER] (Nap=naphthalene-1,8-diyl; ER=SEt, SPh, SePh) 1,3, which contain phosphorus and chalcogen functional groups at the peri positions have been prepared. Each phosphine reacts to form a complete series of PV chalcogenides Nap[P(E,)(Ph2)(ER)] (E,=O, S, Se). The novel compounds were fully characterised by using X-ray crystallography and multinuclear NMR spectroscopy, IR spectroscopy and MS. X-ray data for 1, 2, n,O, n,S, n,Se (n=1,3) are compared. Eleven molecular structures have been analysed by naphthalene ring torsions, peri -atom displacement, splay angle magnitude, X,,,E interactions, aromatic ring orientations and quasi-linear arrangements. An increase in the congestion of the peri region following the introduction of heavy chalcogen atoms is accompanied by a general increase in naphthalene distortion. P,,,E distances increase for molecules that contain bulkier atoms at the peri positions and also when larger chalcogen atoms are bound to phosphorus. The chalcogenides adopt similar conformations that contain a quasi-linear E,,,PC fragment, except for 3,O, which displays a twist-axial-twist conformation resulting in the formation of a linear O,,,SeC alignment. Ab initio MO calculations performed on 2,O, 3,O, 3,S and 3,Se reveal Wiberg bond index values of 0.02 to 0.04, which indicates only minor non-bonded interactions; however, calculations on radical cations of 3,O, 3,S and 3,Se reveal increased values (0.14,0.19). [source] | ||||||||||