39,362 research outputs found
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Steering drift and wheel movement during braking: static and dynamic measurements
YesThis paper reports on an experimental investigation into braking-related steering drift in
motor vehicles, and follows on from a previous paper by the authors in which it was concluded that
braking can cause changes in wheel alignment that in turn affect the toe-steer characteristics of each
wheel and therefore the straight-line stability of the vehicle during braking. Changes in suspension
geometry during braking, their magnitude and the relationships between the braking forces and the
suspension geometry and compliance are further investigated in an experimental study of wheel
movement arising from compliance in the front suspension and the steering system of a passenger
car during braking. Using a kinematic and compliance (K&C) test rig, movement of the front wheels
and the suspension subframe, together with corresponding changes in suspension and steering
geometry under simulated braking conditions, have been measured and compared with dynamic
measurements of the centre points of the front wheels. The results have enabled the causes and effects
of steering drift during braking to be better understood in the design of front suspension systems for
vehicle stability during braking
Using molecular tools to differentiate closely related blackfly species of the genus Simulium
Biodiversity data are the foundation for conservation and managemet and taxonomy provides the reference system, skills and tools used to identify organisms. Species level data such as species richness, composition and diversity are common metrics. However, species level identification of organisms tends to be neglected within ecological work, especially within monitoring programmes, but also in conservation biology (Giangrande, 2003). This is because collection of species level data is time consuming, with identification of species-specific characteristics traditionally involving lengthy examination of samples using microscopy. In addition it is costly and species level data is almost impossible to collect if the taxa involved are species rich and difficult to identify (Báldi 1999). Other reasons why species level identification is neglected include the fact that sample collection can damage organisms, so diagnostic morphological features are lost, or that individuals may be in a life history stage or of a sex that does not have diagnostic morphological characteristics. Furthermore, the numbers of available expert taxonomists needed for species identification are in decline and have been for several decades. Species identification using molecular taxonomy where DNA is used as a marker is championed as a tool for resolving a range of morphological problems, such as the association of all life history stages, correlating male and female specimens to the same species and identifying partial specimens. Traditional taxonomy is built around morphological variations between species, with systematic inferences based upon shared physical characters. In molecular taxonomy on the other hand, proteins and genes are used to determine evolutionary relationships. ’DNA barcoding’ aims to provide an efficient method for species-level identification and it is thought that it will provide a powerful tool for taxonomic and biodiversity research (Hajibabaei et al. 2007). Cited strengths of a molecular based approach to species identification include the potential universality and objective nature of DNA data as taxonomic information, the usefulness of molecular data in animal groups characterized by morphological cryptic characters and the use of DNA sequence information to determine otherwise ‘unidentifiable’ biological material (such as incomplete specimens or immature specimens). Its aim is to increase the speed, precision and efficiency of field studies involving diverse and difficult to identify taxa and it has the potential to be automated to provide a rapid and consistently accurate supplementary identification system to traditional taxonomy. This project was a proof-of-concept study that investigated the feasibility of using DNA barcodes to differentiate closely related blackfly species of the genus Simulium. The longer term objective would be to apply such molecular approaches to organisms used in water quality monitoring and to biodiversity studies to provide a quick, robust but practical and cost effective tool for species identification. Great Britain is currently home to 33 morphospecies of blackfly many of which are morphologically close to other species and have been the cause of much systematic revision. In addition to evaluating the use of DNA barcodes in species identification, a non-destructive DNA extraction method was developed to preserve voucher pecimens that will allow a complete morphological classification to be carried after DNA extraction. Using molecular tools to differentiate closely related blackfly species of the genus Simulium v Finding an effective DNA barcode for an individual species involves accurate taxonomic identification and the retention of voucher specimens for future morphological studies. A rapid non-destructive method for DNA extraction from small insects was developed where no clean-up step was required prior to amplification and it was possible to extract DNA of sufficient quality in minutes retaining diagnostic morphological characteristics. For any molecular tool used for species discrimination, an important consideration is defining the specific genetic loci (e.g. the position of genes on a chromosome) to be monitored. All blackfly species in this study were successfully amplified with the standard barcoding coxI gene primer pair LCO1490 5'-GGT CAA CAA ATC ATA AAG ATA TTG G-3' and HCO2198 5'-TAA ACT TCA GGG TGA CCA AAA AAT CA-3' (Folmer et al. 1994) and we did not need to optimise or redesign the primer sequence
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Wheel movement during braking
YesAn experimental study of wheel movement arising from compliance in the front suspension and
steering system of a passenger car during braking is presented. Using a Kinematic and
Compliance (K&C) test rig, movement of the front wheels and the suspension sub-frame,
together with corresponding changes in suspension / steering geometry under simulated braking
conditions, were measured and compared with dynamic measurements of the centre points of the
front wheels. The resulting knowledge of front wheel deflections has enabled the causes and
effects of steering drift during braking to be better understood in the design of front suspension
systems for vehicle stability
Improved electrode paste provides reliable measurement of galvanic skin response
High-conductivity electrode paste is used in obtaining accurate skin resistance or skin potential measurements. The paste is isotonic to perspiration, is nonirritating and nonsensitizing, and has an extended shelf life
Celebrity worship and incidence of elective cosmetic surgery: evidence of a link among young adults.
Purpose: The purpose of the current study was to explore among young adults whether celebrity worship
predicted the incidence of elective cosmetic surgery within the period of 8 months after controlling for
several known predictors of elective cosmetic surgery.
Methods: A total of 137 young adults completed questionnaire measures of attitudes toward a celebrity
whose body image they admired, previous and vicarious experience of elective cosmetic surgery, attitudes
toward cosmetic surgery, and a range of psychological and demographic measures at time 1. Participants
were then asked to report whether they had undergone elective cosmetic surgery 8 months later.
Results: After controlling for several known predictors of elective cosmetic surgery, intense-personal celebrity
worship of a celebrity whose body shape was admired by the participant predicted the incidence of
elective cosmetic surgery within an 8-month period.
Conclusions: The current findings suggest that the type of para-social relationship that young adults form
with celebrities, particularly with those whose body shape is admired, may need to be considered by those
when speaking to, and educating, young people about their choices around elective cosmetic surgery
Rugged pressed disk electrode has low contact potential
Pressed-disk electrode with low contact potential monitors physiological processes. It consists of silver and silver chloride combined with bentonitic clay. The clay affords a surface that permits use over extended periods without contact deterioration
Physical activity careers and oral histories of family membership: a synthesised approach to understanding physical activity and well-being in family contexts
As it appears physical activity is not a widespread family practice (Day, in press), attempting to collect comprehensive life histories sensitive to connections between physical activity habits and family influences across the life course would be unnecessary. Reflecting upon data from my PhD study and the experience of collecting this data, it is argued that simultaneous investigation of physical activity careers and oral histories of family membership offers a more useful, meaningful and authentic approach. Furthermore, synthesis between career and oral history interviews highlight complex inter-relationships between physical activity experiences, family relationships and recollections of well-being. More specifically, participant’s stories provide rich explanations that are supplementary and different to trends identified between family relationships and well-being in the ‘new science’ of happiness (see Layard, 2011) and assumptions made in the exercise sciences about the contribution of physical activity to well-being. Consequently, people’s accounts of well-being emerge as meaningful, intimate and delicate moments in time that are both memorable and crucial to their physical activity careers and family memberships across the life course. It is thus also suggested that although socialisation is a process, the ways in which interviewees recall, interpret, relive and reinterpret this process in reference to family and physical activity is nonlinear, unpredictable and highly personal. In closing it is tentatively proposed that the methodology outlined represents a more practical and human-centred way of understanding social influences upon physical activity and well-being than has traditionally been utilised in the exercise sciences
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