Modelling risk at low exposure railway level crossings : supporting an argument for low-cost level crossing warning devices with lower levels of safety integrity

This paper describes a risk model for estimating the likelihood of collisions at low-exposure railway level crossings, demonstrating the effect that differences in safety integrity can have on the likelihood of a collision. The model facilitates the comparison of safety benefits between level crossings with passive controls (stop or give-way signs) and level crossings that have been hypothetically upgraded with conventional or low-cost warning devices. The scenario presented illustrates how treatment of a cross-section of level crossings with low cost devices can provide a greater safety benefit compared to treatment with conventional warning devices for the same budget.

High levels of BACH2 associated with lower levels of BCL2 transcript abundance in t(14;18)(q21;q34) translocation positive non-Hodgkin’s lymphoma

The t(14;18)(q21;q34) BCL2 translocation is a common genetic alteration in follicular and diffuse large B-cell lymphoma. However, it is not invariably associated with BCL2 gene overexpression due to undefined mechanisms that regulate expression from the proximal immunoglobulin heavy-chain (IgH) promoter. The BACH2 transcriptional repressor is able to modulate activity of this promoter. Here we have shown that, in tumor samples with BCL2 translocation, those with high levels of BACH2 had significantly lower BCL2 transcript abundance compared to those with low levels of BACH2. This indicates that BACH2 may be partially responsible for regulation of BCL2 expression from the t(14;18)(q21;q34) translocation.

Quantitative sensory measures distinguish office workers with varying levels of neck pain and disability

This study was undertaken to investigate any relationship between sensory features and neck pain in female office workers using quantitative sensory measures to better understand neck pain in this group. Office workers who used a visual display monitor for more than four hours per day with varying levels of neck pain and disability were eligible for inclusion. There were 85 participants categorized according to their scores on the neck disability index (NDI): 33 with no pain (NDI < 8); 38 with mild levels of pain and disability (NDI 9–29); 14 with moderate levels of pain (NDI ⩾ 30). A fourth group of women without neck pain (n = 22) who did not work formed the control group. Measures included: thermal pain thresholds over the posterior cervical spine; pressure pain thresholds over the posterior neck, trapezius, levator scapulae and tibialis anterior muscles, and the median nerve trunk; sensitivity to vibrotactile stimulus over areas of the hand innervated by the median, ulnar and radial nerves; sympathetic vasoconstrictor response. All tests were conducted bilaterally. ANCOVA models were used to determine group differences between the means for each sensory measure. Office workers with greater self-reported neck pain demonstrated hyperalgesia to thermal stimuli over the neck, hyperalgesia to pressure stimulation over several sites tested; hypoaesthesia to vibration stimulation but no changes in the sympathetic vasoconstrictor response. There is evidence of multiple peripheral nerve dysfunction with widespread sensitivity most likely due to altered central nociceptive processing initiated and sustained by nociceptive input from the periphery.

Tailoring surface properties and structure of layered double hydroxides using silanes with different number of functional groups

Four silanes, trimethylchlorosilane (TMCS), dimethyldiethoxylsilane (DMDES), 3-aminopropyltriethoxysilane (APTES) and tetraethoxysilane (TEOS), were adopted to graft layered double hydroxides (LDH) via an induced hydrolysis silylation method (IHS). Fourier transform infrared spectra (FTIR) and 29Si MAS nuclear magnetic resonance spectra (29Si MAS NMR) indicated that APTES and TEOS can be grafted onto LDH surfaces via condensation with hydroxyl groups of LDH, while TMCS and DMDES could only be adsorbed on the LDH surface with a small quantity. A combination of X-ray diffraction patterns (XRD) and 29Si MAS NMR spectra showed that silanes were exclusively present in the external surface and had little influence on the long range order of LDH. The surfactant intercalation experiment indicated that the adsorbed and/or grafted silane could not fix the interlamellar spacing of the LDH. However, they will form crosslink between the particles and affect the further surfactant intercalation in the silylated samples. The replacement of water by ethanol in the tactoids and/or aggregations and the polysiloxane oligomers formed during silylation procedure can dramatically increase the value of BET surface area (SBET) and total pore volumes (Vp) of the products.

Effects of different levels of refractive blur on night-time pedestrian visibility

Purpose The aim of this study was to systematically investigate the effect of different levels of refractive blur and driver age on night-time pedestrian recognition and determine whether clothing that has been shown to improve pedestrian conspicuity is robust to the effects of blur. Methods Night-time pedestrian recognition was measured for 24 visually normal participants (12 younger M=24.9±4.5 years and 12 older adults M=77.6±5.7 years) for three levels of binocular blur (+0.50 D, +1.00 D, +2.00 D) compared to baseline (optimal refractive correction). Pedestrians walked in place on a closed road circuit and wore one of three clothing conditions: i) everyday clothing, ii) a retro-reflective vest and iii) retro-reflective tape positioned on the extremities in a configuration that conveyed biological motion (known as “biomotion”); the order of conditions was randomized between participants. Pedestrian recognition distances were recorded for each blur and pedestrian clothing combination while participants drove an instrumented vehicle around a closed road course. Results The recognition distances for pedestrians were significantly reduced (p<0.05) by all levels of blur compared to baseline. Pedestrians wearing “biomotion” clothing were recognized at significantly longer distances than for the other clothing configurations in all blur conditions. However, these effects were smaller for the older adults, who had much shorter recognition distances for all conditions tested. Conclusions In summary, even small amounts of blur had a significant detrimental effect on night-time pedestrian recognition. Biomotion retro-reflective clothing was effective, even under moderately degraded visibility conditions, for both young and older drivers.

Statistical analysis of synthetic earthquake catalogs generated by models with various levels of fault zone disorder

The stress release model, a stochastic version of the elastic rebound theory, is applied to the large events from four synthetic earthquake catalogs generated by models with various levels of disorder in distribution of fault zone strength (Ben-Zion, 1996) They include models with uniform properties (U), a Parkfield-type asperity (A), fractal brittle properties (F), and multi-size-scale heterogeneities (M). The results show that the degree of regularity or predictability in the assumed fault properties, based on both the Akaike information criterion and simulations, follows the order U, F, A, and M, which is in good agreement with that obtained by pattern recognition techniques applied to the full set of synthetic data. Data simulated from the best fitting stress release models reproduce, both visually and in distributional terms, the main features of the original catalogs. The differences in character and the quality of prediction between the four cases are shown to be dependent on two main aspects: the parameter controlling the sensitivity to departures from the mean stress level and the frequency-magnitude distribution, which differs substantially between the four cases. In particular, it is shown that the predictability of the data is strongly affected by the form of frequency-magnitude distribution, being greatly reduced if a pure Gutenburg-Richter form is assumed to hold out to high magnitudes.

Growth response of Heterobranchus longifilis fingerlings fed with varying levels of dietary freshwater mussel (Aspatharia sinuata)

A common bivalve: Freshwater mussel, Aspatharia sinuate was evaluated as a dietary protein supplement in the production diet for Heterobranchus longifilis fingerlings with mean body weight 8.34 plus or minus 10g reared in aquaria tanks. Four diets containing fishmeal protein at a rate of 25%, 50% and 75% along with the freshwater mussel flesh were formulated. The diet without the freshwater mussel served as the control. The fish fingerlings were fed at 5% body weight per day for 56 days. It was revealed at the end of the experiment that freshwater mussel was most suitable as a protein supplement when incorporated at 25% replacement. The body weight gain, specific growth rate and feed conversion ration values of 6.83g, 1.06% day and 0.62 respectively were highest in diet with 25% replacement closely followed by diet with 50% replacement. Beyond 75% inclusion level there was no significant growth (P>0.05). However, complete replacement of fishmeal by freshwater mussel decreases growth rates and should not be used in Heterobranchus longifilis diets

Talbot effect of a grating with different kinds of flaws

The Talbot effect of a grating with different kinds of flaws is analyzed with the finite-difference time-domain (FDTD) method. The FDTD method can show the exact near-field distribution of different flaws in a high-density grating, which is impossible to obtain with the conventional Fourier transform method. The numerical results indicate that if a grating is perfect, its Talbot imaging should also be perfect; if the grating is distorted, its Talbot imaging will also be distorted. Furthermore, we evaluate high-density gratings by detecting the near-field distribution with the scanning near-field optical microscopy technique. Experimental results are also given. (c) 2005 Optical Society of America.

Estimation of micro-flora associated with different stages of Macrobrachium rosenbergii (de Man)

The bacterial flora occurring in muscle, haemolymph, hepatopancreas and gill of brood, juveniles, water, eggs, larvae and rearing water were estimated by selective plate count technique for Entrobacteriaceae, Streptococaceae and Vibrionaceae members. The total viable bacterial count was estimated by total plate count technique on nutrient agar. The total viable counts of bacteria were lowest in water from 6.10x10² CFU/mL) and highest in egg (6.06x10super(8) CFU/g). In brood the total counts were varying from 1.62x10² CFU/g in muscle to 2.20x10super(5) CFU/g in gills. In juveniles, the total plate counts were varying from 2.8x10super(4) CFU/g in muscles to 3.67x10 super(8) CFU/g in hepatopancreas. Selective plate counts show that Enterobacteriaceae members dominate in egg and gills of brood and hepatopancreas of juveniles. Vibrios were found to be dominant in water and larvae of rearing tank. Haemolymph of brood was sterile and did not contain any bacteria while muscle of juvenile was having very low count of total viable bacteria.

Formulation, processing and water stability of pelleted feeds with varying levels of protein used in carp nutrition studies

Four dry pelleted feeds containing 20%, 30%, 40% and 45% protein were formulated incorporating casein as the main source of protein for use in carp nutrition studies. The caloric content in all the feeds was maintained constant. The method of processing is described. The formulated diets were tested for water stability. This test has revealed that the diet containing 20%, 30% and 40% protein had better stability than that containing 45% protein. This was due to the relatively higher fat content in the former three diets. However, all the feeds were sufficiently stable at the end of one hour in which time carps are known to utilise supplementary diets.

Poly(3-dodecylthiophenes) polymerized with different amounts of catalyst

The effect of the amount of the catalyst FeCl3, used during the direct oxidation polymerization, on the structure and properties of the obtained poly(3-dodecylthiophene) (P3DDT) was investigated in this paper. Such measurements as gel permeation chromatography (GPC), nuclear magnetic resonance (NMR) spectroscopy, thermal analysis, X-ray diffraction, infrared spectroscopy (FTIR) and ultraviolet-visible (W-vis) spectroscopy were applied. It is found that a suitable addition of FeCl3 can contribute to generate a P3DDT with greater percentage of head-to-tail head-to-tail (HT-HT) linkages, which are generally favored. The reduction of the other linkage defects helps to lengthen conjugation length, thus leading to more orderly chain packing. (C) 2000 Elsevier Science S.A. All rights reserved.