An investigation of ride quality rating scales

An experimental investigation was conducted for the combined purposes of determining the relative merits of various category scales for the prediction of human discomfort response to vibration and for determining the mathematical relationships whereby subjective data are transformed from one scale to other scales. There were 16 category scales analyzed representing various parametric combinations of polarity, that is, unipolar and bipolar, scale type, and number of scalar points. Results indicated that unipolar continuous-type scales containing either seven or nine scalar points provide the greatest reliability and discriminability. Transformations of subjective data between category scales were found to be feasible with unipolar scales of a larger number of scalar points providing the greatest accuracy of transformation. The results contain coefficients for transformation of subjective data between the category scales investigated. A result of particular interest was that the comfort half of a bipolar scale was seldom used by subjects to describe their subjective reaction to vibration

Model of aircraft noise adaptation

Development of an aircraft noise adaptation model, which would account for much of the variability in the responses of subjects participating in human response to noise experiments, was studied. A description of the model development is presented. The principal concept of the model, was the determination of an aircraft adaptation level which represents an annoyance calibration for each individual. Results showed a direct correlation between noise level of the stimuli and annoyance reactions. Attitude-personality variables were found to account for varying annoyance judgements

Effect of vibration in combined axes on subjective evaluation of ride quality

The effects of simultaneous sinusoidal vibration in the vertical and lateral axes on ratings of discomfort were investigated. The first experiment concentrated on the effects of variation of frequency in the two axes, and the second study concentrated on the effects of amplitude variation in the two axes

Synthetic and Evolutionary Construction of a Chlorate-Reducing Shewanella oneidensis MR-1.

UnlabelledDespite evidence for the prevalence of horizontal gene transfer of respiratory genes, little is known about how pathways functionally integrate within new hosts. One example of a mobile respiratory metabolism is bacterial chlorate reduction, which is frequently encoded on composite transposons. This implies that the essential components of the metabolism are encoded on these mobile elements. To test this, we heterologously expressed genes for chlorate reduction from Shewanella algae ACDC in the non-chlorate-reducing Shewanella oneidensis MR-1. The construct that ultimately endowed robust growth on chlorate included cld, a cytochrome c gene, clrABDC, and two genes of unknown function. Although strain MR-1 was unable to grow on chlorate after initial insertion of these genes into the chromosome, 11 derived strains capable of chlorate respiration were obtained through adaptive evolution. Genome resequencing indicated that all of the evolved chlorate-reducing strains replicated a large genomic region containing chlorate reduction genes. Contraction in copy number and loss of the ability to reduce chlorate were also observed, indicating that this phenomenon was extremely dynamic. Although most strains contained more than six copies of the replicated region, a single strain with less duplication also grew rapidly. This strain contained three additional mutations that we hypothesized compensated for the low copy number. We remade the mutations combinatorially in the unevolved strain and determined that a single nucleotide polymorphism (SNP) upstream of cld enabled growth on chlorate and was epistatic to a second base pair change in the NarP binding sequence between narQP and nrfA that enhanced growth.ImportanceThe ability of chlorate reduction composite transposons to form functional metabolisms after transfer to a new host is an important part of their propagation. To study this phenomenon, we engineered Shewanella oneidensis MR-1 into a chlorate reducer. We defined a set of genes sufficient to endow growth on chlorate from a plasmid, but found that chromosomal insertion of these genes was nonfunctional. Evolution of this inoperative strain into a chlorate reducer showed that tandem duplication was a dominant mechanism of activation. While copy number changes are a relatively rapid way of increasing gene dosage, replicating almost 1 megabase of extra DNA is costly. Mutations that alleviate the need for high copy number are expected to arise and eventually predominate, and we identified a single nucleotide polymorphism (SNP) that relieved the copy number requirement. This study uses both rational and evolutionary approaches to gain insight into the evolution of a fascinating respiratory metabolism

Cost-effectiveness of voluntary HIV-1 counseling and testing in reducing sexual transmission of HIV-1 in Kenya and Tanzania.

Background Access to HIV-1 voluntary counseling and testing (VCT) is severely limited in less-developed countries. We undertook a multisite trial of HIV-1 VCT to assess its impact, cost, and cost-effectiveness in less-developed country settings.\ud Methods\ud The cost-effectiveness of HIV-1 VCT was estimated for a hypothetical cohort of 10 000 people seeking VCT in urban east Africa. Outcomes were modelled based on results from a randomised controlled trial of HIV-1 VCT in Tanzania and Kenya. Our main outcome measures included programme cost, number of HIV-1 infections averted, cost per HIV-1 infection averted, and cost per disability-adjusted life-year (DALY) saved. We also modelled the impact of targeting VCT by HIV-1 prevalence of the client population, and the proportion of clients who receive VCT as a couple compared with as individuals. Sensitivity analysis was done on all model parameters.\ud Findings\ud HIV-1 VCT was estimated to avert 1104 HIV-1 infections in Kenya and 895 in Tanzania during the subsequent year. The cost per HIV-1 infection averted was US$249 and$346, respectively, and the cost per DALY saved was $12·77 and$17·78. The intervention was most cost-effective for HIV-1-infected people and those who received VCT as a couple. The cost-effectiveness of VCT was robust, with a range for the average cost per DALY saved of $5·16-27·36 in Kenya, and$6·58-45·03 in Tanzania. Analysis of targeting showed that increasing the proportion of couples to 70% reduces the cost per DALY saved to $10·71 in Kenya and$13·39 in Tanzania, and that targeting a population with HIV-1 prevalence of 45% decreased the cost per DALY saved to $8·36 in Kenya and$11·74 in Tanzania.\ud Interpretation\ud HIV-1 VCT is highly cost-effective in urban east African settings, but slightly less so than interventions such as improvement of sexually transmitted disease services and universal provision of nevirapine to pregnant women in high-prevalence settings. With the targeting of VCT to populations with high HIV-1 prevalence and couples the cost-effectiveness of VCT is improved significantly

Seidel elements and mirror transformations

The goal of this article is to give a precise relation between the mirror symmetry transformation of Givental and the Seidel elements for a smooth projective toric variety $X$ with $-K_X$ nef. We show that the Seidel elements entirely determine the mirror transformation and mirror coordinates.Comment: 36 pages. We corrected several issues as pointed out by the refere

(Per)chlorate-reducing bacteria can utilize aerobic and anaerobic pathways of aromatic degradation with (per)chlorate as an electron acceptor.

UnlabelledThe pathways involved in aromatic compound oxidation under perchlorate and chlorate [collectively known as (per)chlorate]-reducing conditions are poorly understood. Previous studies suggest that these are oxygenase-dependent pathways involving O2 biogenically produced during (per)chlorate respiration. Recently, we described Sedimenticola selenatireducens CUZ and Dechloromarinus chlorophilus NSS, which oxidized phenylacetate and benzoate, two key intermediates in aromatic compound catabolism, coupled to the reduction of perchlorate or chlorate, respectively, and nitrate. While strain CUZ also oxidized benzoate and phenylacetate with oxygen as an electron acceptor, strain NSS oxidized only the latter, even at a very low oxygen concentration (1%, vol/vol). Strains CUZ and NSS contain similar genes for both the anaerobic and aerobic-hybrid pathways of benzoate and phenylacetate degradation; however, the key genes (paaABCD) encoding the epoxidase of the aerobic-hybrid phenylacetate pathway were not found in either genome. By using transcriptomics and proteomics, as well as by monitoring metabolic intermediates, we investigated the utilization of the anaerobic and aerobic-hybrid pathways on different electron acceptors. For strain CUZ, the results indicated utilization of the anaerobic pathways with perchlorate and nitrate as electron acceptors and of the aerobic-hybrid pathways in the presence of oxygen. In contrast, proteomic results suggest that strain NSS may use a combination of the anaerobic and aerobic-hybrid pathways when growing on phenylacetate with chlorate. Though microbial (per)chlorate reduction produces molecular oxygen through the dismutation of chlorite (ClO2(-)), this study demonstrates that anaerobic pathways for the degradation of aromatics can still be utilized by these novel organisms.ImportanceS. selenatireducens CUZ and D. chlorophilus NSS are (per)chlorate- and chlorate-reducing bacteria, respectively, whose genomes encode both anaerobic and aerobic-hybrid pathways for the degradation of phenylacetate and benzoate. Previous studies have shown that (per)chlorate-reducing bacteria and chlorate-reducing bacteria (CRB) can use aerobic pathways to oxidize aromatic compounds in otherwise anoxic environments by capturing the oxygen produced from chlorite dismutation. In contrast, we demonstrate that S. selenatireducens CUZ is the first perchlorate reducer known to utilize anaerobic aromatic degradation pathways with perchlorate as an electron acceptor and that it does so in preference over the aerobic-hybrid pathways, regardless of any oxygen produced from chlorite dismutation. D. chlorophilus NSS, on the other hand, may be carrying out anaerobic and aerobic-hybrid processes simultaneously. Concurrent use of anaerobic and aerobic pathways has not been previously reported for other CRB or any microorganisms that encode similar pathways of phenylacetate or benzoate degradation and may be advantageous in low-oxygen environments

On the Crepant Resolution Conjecture in the Local Case

In this paper we analyze four examples of birational transformations between local Calabi-Yau 3-folds: two crepant resolutions, a crepant partial resolution, and a flop. We study the effect of these transformations on genus-zero Gromov-Witten invariants, proving the Coates-Corti-Iritani-Tseng/Ruan form of the Crepant Resolution Conjecture in each case. Our results suggest that this form of the Crepant Resolution Conjecture may also hold for more general crepant birational transformations. They also suggest that Ruan's original Crepant Resolution Conjecture should be modified, by including appropriate "quantum corrections", and that there is no straightforward generalization of either Ruan's original Conjecture or the Cohomological Crepant Resolution Conjecture to the case of crepant partial resolutions. Our methods are based on mirror symmetry for toric orbifolds.Comment: 27 pages. This is a substantially revised and shortened version of my preprint "Wall-Crossings in Toric Gromov-Witten Theory II: Local Examples"; all results contained here are also proved there. To appear in Communications in Mathematical Physic

SESAME: exploring small businesses' behaviour to enhance resilience to flooding

In the United Kingdom, small and medium sized enterprises (SMEs) account for approximately 99.9% of businesses, 60% of the working population and 47% annual turnover. However, despite the important contribution that SMEs make to the economy, this size of business remains under-researched with a significant gap in understanding how the disruption caused by flooding impacts on SMEs from the time at which a flood event occurs through to the 'return' to normal operations. Business continuity management is a recognised approach for enhancing organisational resilience to major disruptions (ISO 22301, 2012). However, this strategic approach to building such resilience in SMEs is under-explored in the literature with a limited range of empirical data to draw on. This paper presents an overview of an inter-disciplinary research project funded by the UK's Engineering and Physical Science Research Council, called SESAME, which examines SMEs' operational response and preparedness to flooding. Furthermore, SESAME consists of four stands of research which bring together a number of disciplines including agent based modelling and simulation, flood modelling, business continuity management, economic modelling and behavioural science. This paper provides an overview of the different research stands within the SESAME project aimed at enhancing SMEs' resilience to flooding