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GPS monitoring of a steel box girder viaduct
Structural performance monitoring of bridges has increased as major infrastructure ages and is required to sustain loads that are significantly greater than those predicted during design. Structural stiffness and/or mass distribution can change over the lifespan of a bridge structure. Resulting changes in profile or resonant frequency provide key indicators of change, and may identify structural defects. Field tests using GPS for monitoring relatively small deformations were carried out on a steel box girder viaduct bridge in the UK. The configuration consisted of five GPS receivers located at key locations on the viaduct and two reference GPS receivers. GPS data was collected at either 10 Hz or 20 Hz and post-processed using proprietary software, along with appropriate filtering and spectral analysis. Three main frequencies were clearly detected by the GPS in the vertical component. A previously reported frequency of approximately 0.56 Hz was identified along with two other frequencies. The peak vertical deflections lie in the range of ± 50 mm, while lateral and longitudinal deflections of much smaller magnitude - in the order of a few mm - are also measured. The use of GPS leads to readily obtained and useful engineering data for continued monitoring of structures
Searching for a talking face: the effect of degrading the auditory signal
Previous research (e.g. McGurk and MacDonald, 1976) suggests that faces and voices are bound automatically, but recent evidence suggests that attention is involved in a task of searching for a talking face (Alsius and Soto-Faraco, 2011). We hypothesised that the processing demands of the stimuli may affect the amount of attentional resources required, and investigated what effect degrading the auditory stimulus had on the time taken to locate a talking face. Twenty participants were presented with between 2 and 4 faces articulating different sentences, and had to decide which of these faces matched the sentence that they heard. The results showed that in the least demanding auditory condition (clear speech in quiet), search times did not significantly increase when the number of faces increased. However, when speech was presented in background noise or was processed to simulate the information provided by a cochlear implant, search times increased as the number of faces increased. Thus, it seems that the amount of attentional resources required vary according to the processing demands of the auditory stimuli, and when processing load is increased then faces need to be individually attended to in order to complete the task. Based on these results we would expect cochlear-implant users to find the task of locating a talking face more attentionally demanding than normal hearing listeners
Deflection and frequency monitoring of the Forth Road Bridge, Scotland, by GPS
Permission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees. Copyright © 2012 Thomas Telford Ltd.The use of carrier phase kinematic GPS (global positioning system) has evolved into a reliable technique to measure both the three-dimensional magnitudes and frequencies of movements of structures. Techniques have been developed that tackle errors caused by multipath, tropospheric delay and issues relating to satellite geometry. GPS-derived movements compare well with data from both design predictions and structural models. Results from field trials carried out on the Forth Road Bridge are presented. This paper brings together key results that outline the procedure as well as a series of new data that indicate other potential applications. GPS data were collected continuously over a period of 46 h at a minimum rate of 10 Hz. During the trials wind speed, wind direction, relative humidity and temperature were also recorded. Frequently there was very heavy traffic flow, and at one point a special load (a 100-t lorry) passed over simultaneously to the heavy daytime flow of traffic. Data from a planned load trial during a brief bridge closure are reported and compared with the limited results available from a finite element model. Measured vibration frequencies are also computed from GPS data and compared with those given in the literature. In addition, results indicating the change in structural characteristics are also presented – in particular changes of mass associated with changes in traffic loading are observed. The results show the performance of GPS as it has developed in recent years, and that it can now reliably be used as a significant part of structural health monitoring schemes, giving both the magnitude of quasi-static deflections in known time periods and hence the frequency of dynamic movements of structures.Forth Estuary Transport Authorit
Options for managing human threats to high seas biodiversity
Areas beyond national jurisdiction (ABNJ) constitute 61% of the world's oceans and are collectively managed by countries under the United Nations Convention on the Law of the Sea (UNCLOS). Growing concern regarding the deteriorating state of the oceans and ineffective management of ABNJ has resulted in negotiations to develop an international legally binding instrument (ILBI) for the conservation and sustainable use of biodiversity beyond national jurisdiction under UNCLOS. To inform these negotiations, we identified existing and emerging human activities and influences that affect ABNJ and evaluated management options available to mitigate the most pervasive, with highest potential for impact and probability of emergence. The highest-ranking activities and influences that affect ABNJ were fishing/hunting, maritime shipping, climate change and its associated effects, land-based pollution and mineral exploitation. Management options are diverse and available through a variety of actors, although their actions are not always effective. Area-based management tools (ABMTs), including marine protected areas (MPAs), were the only consistently effective option to mitigate impacts across high-ranked activities and influences. However, addressing land-based pollution will require national action to prevent this at its source, and MPAs offer only a partial solution for climate change. A new ABNJ ILBI could help unify management options and actors to conserve marine biodiversity and ensure sustainable use. Incorporating a mechanism to establish effective ABMTs into the ILBI will help deliver multiple objectives based on the ecosystem approach
Non-perturbative renormalisation for overlap fermions
Using non-perturbative techniques we have found the renormalisation factor,
Z, in the RI-MOM scheme for quark bilinear operators in quenched QCD. We worked
with overlap fermions using the Luescher-Weisz gauge action. Our calculation
was performed at beta=8.45 at a lattice spacing of 1/a=2.1 GeV using a value of
rho=1.4. Our results show good agreement between the vector and the axial
vector in the zero mass limit. This shows that overlap fermions have good
chiral properties. To attempt to improve the discretisation errors in our
results we subtracted the O(a^2) terms in one-loop lattice perturbation theory
from the Monte Carlo Green functions. In particular we paid attention to the
operators for the observable . We found a value for the renormalisation
constants Z^msbar_(v_2b) and Z^msbar_(v_2a) just less than 1.9 at mu=1/a=2.1
GeV.Comment: 6 pages, 3 figures, uses PoS style, poster presented at Lattice 2005
(Chiral Fermions), to be published in Proceedings of Scienc
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Correlation of the movements of the Severn Suspension Bridge derived with GNSS with Temperature Variations.
In March 2010, four days of GNSS data were gathered on the Severn Suspension Bridge. The GNSS antennas were located on the tops of the four support towers, as well as five locations on the suspension cables. The Severn Bridge has a main suspended span of 998m long. The GNSS data were gathered at rates of 10Hz and 20Hz between the 10th to the 12th and on the morning of the 18th March 2010. In addition to the GNSS data, the air and steel temperatures were gathered every 10 minutes. The GNSS data were processed in an On The Fly manner relative to a reference GNSS receiver located on a solid building adjacent to the Bridge
Examining the equivalence between imagery and execution - Do imagined and executed movements code relative environmental features?
Imagined actions engage some of the same neural substrates and related sensorimotor codes as executed actions. The equivalency between imagined and executed actions has been frequently demonstrated by the mental and physical chronometry of movements; namely, the imagination and execution of aiming movements in a Fitts paradigm. The present study aimed to examine the nature or extent of this equivalence, and more specifically, whether imagined movements encompass the relative environmental features as do executed movements. In two separate studies, participants completed a series of imagined or executed reciprocal aiming movements between standard control targets (no annuli), perceptually small targets (large annuli) and perceptually large targets (small annuli) (Ebbinghaus illusions). The findings of both studies replicated the standard positive relation between movement time and index of difficulty for imagined and executed movements. Furthermore, movement times were longer for targets with surrounding annuli compared to the movement times without the annuli suggesting a general interference effect. Hence, the surrounding annuli caused a longer time, independent of the illusory target size, most likely to avoid a potential collision and more precisely locate the endpoint. Most importantly, this feature could not be discriminated as a function of the task (imagined vs. executed). These findings lend support to the view of a common domain for imagined and executed actions, while elaborating on the precision of their equivalence
The Effect of Focal Damage to the Right Medial Posterior Cerebellum on Word and Sentence Comprehension and Production
Functional imaging studies of neurologically intact adults have demonstrated that the
right posterior cerebellum is activated during verb generation, semantic processing,
sentence processing, and verbal fluency. Studies of patients with cerebellar damage
converge to show that the cerebellum supports sentence processing and verbal
fluency. However, to date there are no patient studies that investigated the specific
importance of the right posterior cerebellum in language processing, because: (i)
case studies presented patients with lesions affecting the anterior cerebellum (with or
without damage to the posterior cerebellum), and (ii) group studies combined patients
with lesions to different cerebellar regions, without specifically reporting the effects
of right posterior cerebellar damage. Here we investigated whether damage to the
right posterior cerebellum is critical for sentence processing and verbal fluency in four
patients with focal stroke damage to different parts of the right posterior cerebellum (all
involving Crus II, and lobules VII and VIII). We examined detailed lesion location by going
beyond common anatomical definitions of cerebellar anatomy (i.e., according to lobules
or vascular territory), and employed a recently proposed functional parcellation of the
cerebellum. All four patients experienced language difficulties that persisted for at least a
month after stroke but three performed in the normal range within a year. In contrast, one
patient with more damage to lobule IX than the other patients had profound long-lasting
impairments in the comprehension and repetition of sentences, and the production of
spoken sentences during picture description. Spoken and written word comprehension
and visual recognition memory were also impaired, however, verbal fluency was within
the normal range, together with object naming, visual perception and verbal shortterm
memory. This is the first study to show that focal damage to the right posterior
cerebellum leads to language difficulties after stroke; and that processing impairments
persisted in the case with most damage to lobule IX. We discuss these results in
relation to current theories of cerebellar contribution to language processing. Overall, our study highlights the need for longitudinal studies of language function in patients
with focal damage to different cerebellar regions, with functional imaging to understand
the mechanisms that support recovery
The effect of action observation and motor imagery combinations on upper limb kinematics and EMG during dart-throwing
Recent research has begun to employ interventions that combine action observation and motor imagery (AOMI) with positive results. However, little is known about the underpinning facilitative effect on performance. Participants (n = 50) were randomly allocated to one of five training groups: action observation (AO), motor imagery (MI), simultaneous action observation and motor imagery (S‐AOMI), alternate action observation and motor imagery (A‐AOMI), and control. The task involved dart‐throwing at a concentric circle dartboard at pre‐ and post‐test. Interventions were conducted 3 times per week for 6 weeks. Data were collected from performance outcomes and mean muscle activation of the upper and forearm muscles. Angular velocity and peak angular velocity measurements of the elbow were also collected from the throwing arm. Results showed performance of the A‐AOMI group improved to a significantly greater degree than the AO (P = .04), MI (P = .04), and control group (P = .02), and the S‐AOMI group improved to a greater degree than the control group (P = .02). Mean muscle activation of the triceps brachii significantly reduced in the S‐AOMI and A‐AOMI (P < .01) groups, and participants in the AO (P = .04), A‐AOMI, and S‐AOMI (P < .01) groups significantly reduced activation in the bicep brachii from pre‐ to post‐test. Peak angular velocity significantly decreased from pre‐ to post‐test in both A‐AOMI and S‐AOMI (P < .01) groups. The results reaffirm the benefits of AOMI for facilitating skill learning and provide an insight how these interventions produce favorable changes in EMG and movement kinematics
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Site-targeted mutagenesis for stabilization of recombinant monoclonal antibody expressed in tobacco (Nicotiana tabacum) plants.
This study examined the degradation pattern of a murine IgG1κ monoclonal antibody expressed in and extracted from transformed Nicotiana tabacum. Gel electrophoresis of leaf extracts revealed a consistent pattern of recombinant immunoglobulin bands, including intact and full-length antibody, as well as smaller antibody fragments. N-terminal sequencing revealed these smaller fragments to be proteolytic cleavage products and identified a limited number of protease-sensitive sites in the antibody light and heavy chain sequences. No strictly conserved target sequence was evident, although the peptide bonds that were susceptible to proteolysis were predominantly and consistently located within or near to the interdomain or solvent-exposed regions in the antibody structure. Amino acids surrounding identified cleavage sites were mutated in an attempt to increase resistance. Different Guy's 13 antibody heavy and light chain mutant combinations were expressed transiently in N. tabacum and demonstrated intensity shifts in the fragmentation pattern, resulting in alterations to the full-length antibody-to-fragment ratio. The work strengthens the understanding of proteolytic cleavage of antibodies expressed in plants and presents a novel approach to stabilize full-length antibody by site-directed mutagenesis.-Hehle, V. K., Paul, M. J., Roberts, V. A., van Dolleweerd, C. J., Ma, J. K.-C. Site-targeted mutagenesis for stabilization of recombinant monoclonal antibody expressed in tobacco (Nicotiana tabacum) plants
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