Distributed implementation of the adaptive kinetic Monte Carlo method

The program EON2 is a distributed implementation of the adaptive kinetic Monte Carlo method for long time scale simulations of atomistic systems. The method is based on the transition state theory approach within the harmonic approximation and the key step is the identification of relevant saddle points on the potential energy rim surrounding the energy minimum corresponding to a state of the system. The saddle point searches are carried out in a distributed fashion starting with random initial displacements of the atoms in regions where atoms have less than optimal coordination. The main priorities of this implementation have been to (1) make the code transparent, (2) decouple the master and slaves, and (3) have a well defined interface to the energy and force evaluation. The computationally intensive parts are implemented in C++, whereas the less compute intensive server-side software is written in Python. The platform for distributed computing is BOINC. A simulation of the annealing of a twist and tilt grain boundary in a copper crystal is described as an example application.     

Per-glycosylation of the Surface-Accessible Lysines: One-Pot Aqueous Route to Stabilized Proteins with Native Activity

Chemical glycosylation of proteins is a powerful tool applied widely in biomedicine and biotechnology. However, it is a challenging undertaking and typically relies on recombinant proteins and site-specific conjugations. The scope and utility of this nature-inspired methodology would be broadened tremendously by the advent of facile, scalable techniques in glycosylation, which are currently missing. In this work, we investigated a one-pot aqueous protocol to achieve indiscriminate, surface-wide glycosylation of the surface accessible amines (lysines and/or N-terminus). We reveal that this approach afforded minimal if any change in the protein activity and recognition events in biochemical and cell culture assays, but at the same time provided a significant benefit of stabilizing proteins against aggregation and fibrillation - as demonstrated on serum proteins (albumins and immunoglobulin G, IgG), an enzyme (uricase), and proteins involved in neurodegenerative disease (α-synuclein) and diabetes (insulin). Most importantly, this highly advantageous result was achieved via a one-pot aqueous protocol performed on native proteins, bypassing the use of complex chemical methodologies and recombinant proteins.     

联合利华伦敦总部改扩建设计

<正>联合利华伦敦总部(VE步行街100号)地处伦敦重要地段,此处可俯瞰黑衣修士桥(Blackfriars Bridge)及泰晤士河。联合利华总部落成于1931年,并于1977年被列入二级文物保护建筑物,而KPF事务所的任务正是重新设计改造20世纪30年代落成的总部楼体结构以及20世纪70年代楼体北扩工程的部分工作。     

The potential use of time reversal techniques in multiple element antenna systems

Based on outdoor measurements we study the feasibility of applying the time reversal techniques (TR) in multiple element antenna (MEA) wireless communication systems. It is demonstrated that the use of TR in wireless communication has a promising potential in mitigating the effect of channel dispersion and especially in reducing the cochannel interference where a margin of 18 dB interference reduction has been obtained.     

Corrosion in waste-fired boilers: A thermodynamic study

A twofold study using thermodynamic equilibrium calculations was carried out to study corrosion in MSW incinerators. Corrosion was associated with the amount of alkalis and trace metals gaseous chlorides. Firstly, a two-level factorial experimental design combined with a data analysis were used to determine the main and interaction effects for various alkalis and trace metals gaseous chlorides responses. The factors studied were Na, K, S and Cl concentrations. The results provided a picture of the controlling parameters and insight about the processes taking place. Secondly, the efficiency of two corrosion-fighting additives (ammonium sulphate and silica) was investigated. Calculations confirmed experimental results and brought further insight on differentiated results for Na, K, Pb and Zn but also on capture mechanisms.     

Temperature measurement during solidification of thin wall ductile cast iron. Part 1: Theory and experiment

Temperature measurement using thermocouples (TCs) influences solidification of the casting, especially in thin wall castings. The problems regarding acquisition of detailed cooling curves from thin walled castings are discussed.

Experiments were conducted where custom made TCs were used to acquire cooling curves in thin wall ductile iron castings. The experiments show how TCs of different designs interact with the melt and how TC design and surface quality affect the results of the data acquisition. It is discussed as to what precautions should be taken to ensure reliable acquisition of cooling curves. Measurement error depending on TC design and cooling conditions is shown.

A method is presented that allows acquisition of cooling curves in thin walled ductile iron castings down to a thickness of at least 2.8 mm. The obtained cooling curves can be used to compare nucleation and growth during solidification of castings with different plate thicknesses.     

When in Rome: Factors associated with changes in drinking behavior among American college students studying abroad.

Study abroad programs have the potential to promote cultural, experiential, and personal development for escalating numbers of American college students each year. Despite reports that study abroad students may be at particular risk for increased and problematic alcohol use, there is limited empirical documentation of this risk. Thus, the present study used a longitudinal design to examine the factors associated with changes in alcohol use among college students studying in foreign countries. A sample of 177 students completed measures of demographics, drinking behavior, and perceived peer drinking behavior 1 month before departure and 1-month postreturn from study abroad trips. Analyses revealed that participants more than doubled their drinking during study abroad trips and those who drank at heavier levels while abroad returned home drinking at significantly elevated levels. This pattern of increased use while abroad was moderated by several factors, with participants studying abroad in Europe (e.g., Italy, France) and Oceania (e.g., Australia, New Zealand), those under the age of 21, those with higher intentions of drinking while abroad, and those with higher drinking perceptions of other study abroad students in their host country increased their alcohol consumption to a greater extent than other participants. Results suggest drinking while abroad is a concern warranting further investigation, especially regarding how changes in drinking may contribute to the experience of alcohol-related consequences abroad. Continued identification of the risk factors associated with increased drinking can help inform targeted predeparture preventive interventions with these students. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adsorption of Insecticidal Cry1Ab Protein to Humic Substances. 2. Influence of Humic and Fulvic Acid Charge and Polarity Characteristics

Assessing the fate and potential risks of transgenic Cry proteins in soils requires understanding of Cry protein adsorption to soil particles. The companion paper provided evidence that patch-controlled electrostatic attraction (PCEA) and the hydrophobic effect contributed to Cry1Ab protein adsorption to an apolar humic acid (HA). Here, we further assess the relative importance of these contributions by comparing Cry1Ab adsorption to seven humic substances varying in polarity and charge, at different solution pH and ionic strength, I. Cry1Ab adsorption to relatively apolar HAs at I = 50 mM exhibited rapid initial rates, was extensive, and was only partially reversible at pH 5-8, whereas adsorption to more polar fulvic acids was weak and reversible or absent at pH >6. The decrease in adsorption with increasing HS polarity at all tested pH strongly supports a large contribution from the hydrophobic effect to adsorption, particularly at I = 50 mM when PCEA was effectively screened. Using insect bioassays, we further show that Cry1Ab adsorbed to a selected HA retained full insecticidal activity. Our results highlight the need to consider adsorption to soil organic matter in models that assess the fate of Cry proteins in soils.     

Antifouling effect of hydrogen peroxide release from enzymatic marine coatings: Exposure testing under equatorial and Mediterranean conditions

Hydrogen peroxide (H₂O₂) may be considered an environmentally friendly antifouling alternative to common biocides such as Cu₂O and various organic compounds. In this work, the efficiency of antifouling coatings releasing hydrogen peroxide via enzyme-mediated conversion of starch, under Mediterranean and equatorial climatic conditions, is investigated. During seawater exposure of the coatings, starch is first converted to glucose by glucoamylase (rate-controlling step) and subsequently glucose is rapidly oxidised by hexose oxidase in a reaction producing hydrogen peroxide.