Novel material combinations for enhanced infrared filter performance

The introduction of non-toxic fluride compounds as direct replacements for Thorium Fluoride (ThF4) has renewed interest in the use of low index fluoride compounds in high performance infrared filters. This paper reports the results of an investigation into the effects of combining these low index materials, particularly Barium Fluoride (BaF2), with the high index material Lead Telluride (PbTe) in bandpass and edge filters. Infrared filter designs using conventional and the new material ombination are compared, and infrared filters using these material combinations have been manufactured and have been shown to suffer problems with residual stress. A possible solution to this problem utilising Zinc Sulphide (ZnS) layers with compensating compressive stress is discussed.

Multilayer filters and coatings for the region 4-40 µm: new material combinations

The vacuum-deposited layer properties of materials of possible new use in infrared filters and coatings are described. These are comprehensively drawn from the II/VI, the heavy halide and the V/VI glass compounds, and are commercially available in all cases. Novel applications in coatings and filters are given for many of the materials.

The effect of copper(II), iron(II) sulphate and vitamin C combinations on the weak antimicrobial activity of (+)-catechin against Staphylococcus aureus and other microbes

Few attempts have been made to improve the activity of plant compounds with low antimicrobial efficacy. (+)-Catechin, a weak antimicrobial tea flavanol, was combined with putative adjuncts and tested against different species of bacteria. Copper(II) sulphate enhanced (+)-catechin activity against Pseudomonas aeruginosa but not Staphylococcus aureus, Proteus mirabilis or Escherichia coli. Attempts to raise the activity of (+)-catechin against two unresponsive species, S. aureus and E. coli, with iron(II) sulphate, iron(III) chloride, and vitamin C, showed that iron(II) enhanced (+)-catechin against S. aureus, but not E. coli; neither iron(III) nor combined iron(II) and copper(II), enhanced (+)-catechin activity against either species. Vitamin C enhanced copper(II) containing combinations against both species in the absence of iron(II). Catalase or EDTA added to active samples removed viability effects suggesting that active mixtures had produced H2O2via the action of added metal(II) ions. H2O2 generation by (+)-catechin plus copper(II) mixtures and copper(II) alone could account for the principal effect of bacterial growth inhibition following 30 minute exposures as well as the antimicrobial effect of (+)-catechin–iron(II) against S. aureus. These novel findings about a weak antimicrobial flavanol contrast with previous knowledge of more active flavanols with transition metal combinations. Weak antimicrobial compounds like (+)-catechin within enhancement mixtures may therefore be used as efficacious agents. (+)-Catechin may provide a means of lowering copper(II) or iron(II) contents in certain crop protection and other products.

Environmental oestrogens and breast cancer: long-term low-dose effects of mixtures of various chemical combinations

The incidence of breast cancer has risen worldwide to unprecedented levels in recent decades, making it now the major cancer of women in many parts of the world.1 Although diet, alcohol, radiation and inherited loss of BRCA1/2 genes have all been associated with increased incidence, the main identified risk factors are life exposure to hormones including physiological variations associated with puberty/pregnancy/menopause,1 personal choice of use of hormonal contraceptives2 and/or hormone replacement therapy.3–6 On this basis, exposure of the human breast to the many environmental pollutant chemicals capable of mimicking or interfering with oestrogen action7 should also be of concern.8 Hundreds of such environmental chemicals have now been measured in human breast tissue from a range of dietary and domestic exposure sources7 ,9 including persistent organochlorine pollutants (POPs),10 polybrominated diphenylethers and polybromobiphenyls,11 polychlorinated biphenyls,12 dioxins,13 alkyl phenols,14 bisphenol-A and chlorinated derivatives,15 as well as other less lipophilic compounds such as parabens (alkyl esters of p-hydroxybenzoic acid),16 but studies investigating any association between raised levels of such compounds and the development of breast cancer remain inconclusive.7–16 However, the functionality of these chemicals has continued to be assessed on the basis of individual chemicals rather than the environmental reality of long-term low-dose exposure to complex mixtures. This misses the potential for individuals to have high concentrations of different compounds but with a common mechanism of action. It also misses the complex interactions between chemicals and physiological hormones which together may act to alter the internal homeostasis of the oestrogenic environment of mammary tissue.

Combinations of parabens at concentrations measured in human breast tissue can increase proliferation of MCF-7 human breast cancer cells

The alkyl esters of p-hydroxybenzoic acid (parabens), which are used as preservatives in consumer products, possess oestrogenic activity and have been measured in human breast tissue. This has raised concerns for a potential involvement in the development of human breast cancer. In this paper, we have investigated the extent to which proliferation of MCF-7 human breast cancer cells can be increased by exposure to the five parabens either alone or in combination at concentrations as recently measured in 160 human breast tissue samples. Determination of no-observed-effect concentrations (NOEC), lowest-observed-effect concentrations (LOEC), EC50 and EC100 values for stimulation of proliferation of MCF-7 cells by five parabens revealed that 43/160 (27%) of the human breast tissue samples contained at least one paraben at a concentration ≥ LOEC and 64/160 (40%) > NOEC. Proliferation of MCF-7 cells could be increased by combining all five parabens at concentrations down to the 50th percentile (median) values measured in the tissues. For the 22 tissue samples taken at the site of ER + PR + primary cancers, 12 contained a sufficient concentration of one or more paraben to stimulate proliferation of MCF-7 cells. This demonstrates that parabens, either alone or in combination, are present in human breast tissue at concentrations sufficient to stimulate the proliferation of MCF-7 cells in vitro, and that functional consequences of the presence of paraben in human breast tissue should be assessed on the basis of all five parabens and not single parabens individually.

Market transparency and collusion: on the UK agricultural tractor registration exchange

We review the decision by the European Commission in the case of the UK Agricultural Registration Exchange. We propose a theoretical model, offering a basis for some of the intuitive arguments used by the Commission on the anti-competitive role of information exchange in the case of price and non price collusion. Market transparency on non price data is shown to be a collusion facilitating device which may achieve stability in otherwise unstable cartels.

Exploring combinations of different color and facial expression stimuli for gaze-independent BCIs

Background: Some studies have proven that a conventional visual brain computer interface (BCI) based on overt attention cannot be used effectively when eye movement control is not possible. To solve this problem, a novel visual-based BCI system based on covert attention and feature attention has been proposed and was called the gaze-independent BCI. Color and shape difference between stimuli and backgrounds have generally been used in examples of gaze-independent BCIs. Recently, a new paradigm based on facial expression changes has been presented, and obtained high performance. However, some facial expressions were so similar that users couldn't tell them apart, especially when they were presented at the same position in a rapid serial visual presentation (RSVP) paradigm. Consequently, the performance of the BCI is reduced. New Method: In this paper, we combined facial expressions and colors to optimize the stimuli presentation in the gaze-independent BCI. This optimized paradigm was called the colored dummy face pattern. It is suggested that different colors and facial expressions could help users to locate the target and evoke larger event-related potentials (ERPs). In order to evaluate the performance of this new paradigm, two other paradigms were presented, called the gray dummy face pattern and the colored ball pattern. Comparison with Existing Method(s): The key point that determined the value of the colored dummy faces stimuli in BCI systems was whether the dummy face stimuli could obtain higher performance than gray faces or colored balls stimuli. Ten healthy participants (seven male, aged 21–26 years, mean 24.5 ± 1.25) participated in our experiment. Online and offline results of four different paradigms were obtained and comparatively analyzed. Results: The results showed that the colored dummy face pattern could evoke higher P300 and N400 ERP amplitudes, compared with the gray dummy face pattern and the colored ball pattern. Online results showed that the colored dummy face pattern had a significant advantage in terms of classification accuracy (p < 0.05) and information transfer rate (p < 0.05) compared to the other two patterns. Conclusions: The stimuli used in the colored dummy face paradigm combined color and facial expressions. This had a significant advantage in terms of the evoked P300 and N400 amplitudes and resulted in high classification accuracies and information transfer rates. It was compared with colored ball and gray dummy face stimuli.

A Road Following Approach Using Artificial Neural Networks Combinations

Navigation is a broad topic that has been receiving considerable attention from the mobile robotic community over the years. In order to execute autonomous driving in outdoor urban environments it is necessary to identify parts of the terrain that can be traversed and parts that should be avoided. This paper describes an analyses of terrain identification based on different visual information using a MLP artificial neural network and combining responses of many classifiers. Experimental tests using a vehicle and a video camera have been conducted in real scenarios to evaluate the proposed approach.

Evaluation of galling resistance for some selected combinations of tool steels/stainless steel sheet materials/lubricants using pin-on-disc testing

Stainless steels are well known to be prone to cold welding and material transfer in sliding contacts and therefore difficult to cold form unless certain precautions as discussed in this paper are taken. In the present study different combinations of tool steels/stainless steels/lubricants has been evaluated with respect to their galling resistance using pin-on-disc testing. The results show that a high galling resistance is favored by a high stainless steel sheet hardness and a blasted stainless steel sheet surface topography. The effect of type of lubricant was found to be more complex. For example, the chlorinated lubricants failed to prevent metal-to-metal contact on a brushed sheet surface but succeeded on a blasted sheet surface of the same stainless steel material. This is believed to be due to a protective tribofilm which is able to form on the blasted surface, but not on the brushed surface.

Preparers’ and non-preparers’ lobbying on the proposed prohibition of goodwill amortisation in ED3 ‘business combinations’

In this paper preparers’ and non-preparers’ positions regarding accounting for goodwill are examined through studying submitted comment letters on ED3 ‘Business Combinations’. Preparers have, because of economic consequences, incentives to lobby for the non-amortisation approach and non-preparers for the amortisation approach. As hypothesised, non-preparers are found to support amortisation of goodwill to a greater extent than do preparers. Moreover, the two groups’ supportive arguments, i.e. how they argue for or against the non-amortisation or amortisation approach, are studied. Again, as hypothesised, the results show that the two groups use the same type of ‘sophisticated’ framework based arguments instead of economic consequences arguments. Taken together the examination of the comment letters thus indicates that both preparers and non-preparers point at conceptual strengths and weaknesses, instead of pointing at the real cause of the lobbying activities, i.e. perceived economic consequences, when they try to affect the final outcome of the standard. These findings confirm earlier research which has suggested that self-interested lobbyists use accounting theories and concepts as useful justifications.

Culture-based fisheries in small reservoirs in northern Vietnam: effect of stocking densities and species combinations

This study was conducted in 20 reservoirs, ranging in size from 4 to 30 ha, in the mountainous, northern region of Vietnam, in ThaiNguyen and YenBai provinces, over two growth cycles in 2002/03 and 2003/04. The reservoirs are leased by farmers for fishery activities from the provincial administration, and the trials were managed by the lessee farmers. Three species combinations in ratios (by fingerling weight) of grass carp: silver carp: bighead carp: common carp: mrigal 1:2:1:1:3 (A), 1:3:1:1:2 (B) and 1:2:1:1:2 (C) were used as seed stock. The overall mean yield of stocked fish in 2002/03 and 2003/04 growth cycles in reservoirs in ThaiNguyen and YenBai provinces was 165 (±21) and 190 (39), and 287 (±22) and 325 (±24) kg ha⁻¹ respectively. The yield in reservoirs in both provinces, in both growth cycles and irrespective of the species combinations, increased in relation to stocking density. In reservoirs in ThaiNguyen Province, the species combination B gave the lowest yield (both growth cycles and overall), and differed significantly (P<0.05) from combinations A and C. The stocking efficiency (ratio of the yield of stocked fish in kg ha⁻¹ to the weight of the stocked fish in kg ha⁻¹) in reservoirs in ThaiNguyen Province ranged from 2.9 to 5.1 over the two growth cycles and that in YenBai from 2.8 to 3.9. There was no discernible trend between growth cycles and/or between species combinations. The major cost incurred was for fingerling procurement. In all instances, a net profit was accrued. The mean (±standard error (SE)) net profit ha⁻¹ (in 103VN dong; approximately 15 500 VND=1 US$) was 885 (±270) and 864 (±214), and 1322 (±176) and 1600 (±150) for the growth cycles 2002/03 and 2003/04 for reservoirs in ThaiNguyen and YenBai provinces respectively. Between the two growth cycles, the net profit increased in eight and three reservoirs from YenBai and ThaiNguyen, respectively, the maximum increase being recorded in Khuan Gio (165%) and Dong Man (39%) reservoirs.

Finding coverage using incremental attribute combinations

Coverage is the range that covers only positive samples in attribute (or feature) space. Finding coverage is the kernel problem in induction algorithms because of the fact that coverage can be used as rules to describe positive samples. To reflect the characteristic of training samples, it is desirable that the large coverage that cover more positive samples. However, it is difficult to find large coverage, because the attribute space is usually very high dimensionality. Many heuristic methods such as ID3, AQ and CN2 have been proposed to find large coverage. A robust algorithm also has been proposed to find the largest coverage, but the complexities of time and space are costly when the dimensionality becomes high. To overcome this drawback, this paper proposes an algorithm that adopts incremental feature combinations to effectively find the largest coverage. In this algorithm, the irrelevant coverage can be pruned away at early stages because potentially large coverage can be found earlier. Experiments show that the space and time needed to find the largest coverage has been significantly reduced.