Local Mechanical Perturbation Provides an Effective Means to Regulate the Growth and Assembly of Functional Peptide Fibrils

Mucin 1 (MUC1) peptide fused with Q11 (MUC1‐Q11) having 35 residues has previously been shown to form amyloid fibrils. Using time‐dependent and high‐resolution atomic force microscopy (AFM) imaging, it is revealed that the formation of individual MUC1‐Q11 fibrils entails nucleation and extension at both ends. This process can be altered by local mechanical perturbations using AFM probes. This work reports two specific perturbations and outcomes. First, by increasing load while maintaining tip‐surface contact, the fibrils are cut during the scan due to shearing. Growth of fibrils occurs at the newly exposed termini, following similar mechanism of the MUC1‐Q11 nucleation growth. As a result, branched fibrils are seen on the surface whose orientation and length can be controlled by the nuclei orientation and reaction time. In contrast to the “one‐time‐cut”, fibrils can be continuously fragmented by modulation at sufficiently high amplitude. As a result, short and highly branched fibrils accumulate and pile on surfaces. Since the fibril formation and assembly of MUC1‐Q11 can be impacted by local mechanical force, this approach offers a nonchemical and label‐free means to control the presentation of MUC1 epitopes, and has promising application in MUC1 fibril‐based immunotherapy.     

Plasmonic focusing reduces ensemble linewidth of silver-coated gold nanorods

Silver coating gold nanorods reduces the ensemble plasmon line width by changing the relation connecting particle shape and plasmon resonance wavelength. This change, we term "plasmonic focusing", leads to less variation of resonance wavelengths for the same particle size distribution. We also find smaller single particle linewidth comparing resonances at the same wavelength but show that this does not contribute to the ensemble linewidth narrowing.     

Propagation delay optimisation in multistage GaAs m.e.s.f.e.t. combinational logic circuits by use of dynamic programming

Propagation delays in multistage combinational logic circuits using GaAs metal-semiconductor field-effect transistors (m.e.s.f.e.t.s) are optimised subject to constraints on the overall power dissipation. Specific optimisation criteria are derived for 1-stage, 2-stage, and 3-stage combinational logic circuits. The results are evaluated with parameters of an existing process.     

The effect of heating on the haemagglutinating activity and nutritional properties of bean (Phaseolus vulgaris) seeds

The toxic lectins present in red, white and black kidney beans (Phaseolus vulgaris) are sensitive to heat treatment and the efficiency of that treatment is greatly improved by pre-soaking of the seeds. Heating of pre-soaked seeds at all temperatures above 75°C caused a continuous reduction in both their haemagglutinating activity and toxicity. However, the only safe method of eliminating toxicity was to heat the fully hydrated seeds to 100°C for a minimum of 10 min.     

Energy policy and social development: notes on Trinidad-Tobago and Venezuela

Trinidad-Tobago and Venezuela both show lop-sided development with high wages existing alongside high unemployment. The authors propose the promotion of these countries as ‘energy havens’ as a modest solution to this problem. The aim would be to attract industries more labour intensive than the petroleum industry — which dominates their economies at present — by offering cheap energy supplies.     

The microbiological extraction of less common metals

A developing technology, the microbiological leaching of the less-common and rare metals has yet to reach commercial maturity. Still, although the data are preliminary in nature, the ultimate application of biotechnological principles may provide a potential solution for the valorization of many low-grade mineral resources. The development of these processes for large-scale commercial applications will create new opportunities and challenges for the research community and minerals processing industry.     

Decision-Support Tool for Assessing the Environmental Effects of Constructing Commercial Buildings

Construction of commercial buildings consumes significant amounts of energy and produces lots of emissions and waste. Where should environmental improvement efforts be focused during design and construction? The Construction Environmental Decision-Support Tool allows designers and industry practitioners to quantify energy use, emissions, and waste generation rates due to the construction phase of commercial buildings. A case study of the Bren School at the University of California, Santa Barbara, and several relevant construction scenarios are analyzed. When considering the complete building over its entire life cycle, the construction phase comprised 2% of energy consumption, 1% of CO2 emissions, 7% of CO emissions, 8% of NOx emissions, 8% of PM10 emissions, and 1% of SO2 emissions. This is due to the dominance of the long-term use phase (50?years) compared to a relatively short construction phase (2?years). Scaling up to the national level, however, construction impacts of projects are significant. In each of the categories studied (temporary materials, equipment and materials transportation, equipment use, waste generation), there are actions that can be taken by designers and builders to improve construction phase environmental effects. In structural frame construction, particular areas of concern include material and equipment selection and temporary material use. Energy use and air emissions are primarily due to equipment use, which accounts for at least 50% of most types of emissions. The major contributors are concrete mixer trucks, concrete pumps, cranes, and air compressors. A single feasible decision, such as using a concrete mixer truck with a 335?hp engine instead of one with a 565?hp engine (but having the same capacity) would reduce total construction energy demand by 12%, and the emissions of CO, NO2, PM10, SO2, CO2, and HC by 3, 12, 8, 10, 12, and 10%, respectively. The use of significantly older equipment can have a formidable effect on construction phase emissions. In general, equipment larger that 175?hp made prior to 1996 tends to have significantly greater emissions of HC, CO, and NO2 than more recent models. The majority of waste generated during construction of the structural frame consists of concrete and wood.     

Variability of organophosphorus insecticide residues in large size crops grown in commercial farms in Brazil

Field trials were conducted in commercial agricultural areas in Brazil to determine the variability of residues of parathion methyl, diazinon and methidathion in individual units of large crops treated twice with a mixture of the three pesticides. Over 120 random samples were collected, extracted with ethyl acetate and residues determined by GC/FPD. The recoveries and their coefficient of variation were, in general, within the acceptable levels during sample analyses. Residues in papaya and mango were not affected by the position of the fruits in the plant, apparently more or less exposed to the pesticides. Variability factor υ, defined as the 97.5th percentile divided by the mean of residues in all samples taken from a field ranged from 2.0-2.6. The variability of residues within the plant contributed to about 34-61% of the field variability. The results found in this study support the variability factor of 3 adopted by the FAO/WHO for the deterministic estimation of dietary acute intake of pesticides.     

System boundary selection in life-cycle inventories using hybrid approaches

Life-cycle assessment (LCA) is a method for evaluating the environmental impacts of products holistically, including direct and supply chain impacts. The current LCA methodologies and the standards by the International Organization for Standardization (ISO) impose practical difficulties for drawing system boundaries; decisions on inclusion or exclusion of processes in an analysis (the cutoff criteria) are typically not made on a scientific basis. In particular, the requirement of deciding which processes could be excluded from the inventory can be rather difficult to meet because many excluded processes have often never been assessed by the practitioner, and therefore, their negligibility cannot be guaranteed. LCA studies utilizing economic input-output analysis have shown that, in practice, excluded processes can contribute as much to the product system under study as included processes; thus, the subjective determination of the system boundary may lead to invalid results. System boundaries in LCA are discussed herein with particular attention to outlining hybrid approaches as methods for resolving the boundary selection problem in LCA. An input-output model can be used to describe at least a part of a product system, and an ISO-compatible system boundary selection procedure can be designed by applying hybrid input-output-assisted approaches. There are several hybrid input-output analysis-based LCA methods that can be implemented in practice for broadening system boundary and also for ISO compliance.