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1.
Inj Prev ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862212

RESUMO

BACKGROUND: Police road crash and injury data in low-income and middle-income countries are known to under-report crashes, fatalities and injuries, especially for vulnerable road users. Local record keepers, who are members of the public, can be engaged to provide an additional source of crash and injury data. METHODS: This paper compares the application of a local record keeper method to capture road crash and injury data in Bangladesh and Nepal, assesses the quality of the data collected and evaluates the replicability and value of the methodology using a framework developed to evaluate the impact of being a local record keeper. OUTCOME: Application in research studies in both Bangladesh and Nepal found the local record keeper methodology provided high-quality and complete data compared with local police records. The methodology was flexible enough to adapt to project and context differences. The evaluation framework enabled the identification of the challenges and unexpected benefits realised in each study. This led to the development of an 11-step process for conducting road crash data collection using local record keepers, which is presented to facilitate replication in other settings. CONCLUSION: Data collected by local record keepers are a flexible and replicable method to understand the strengths and limitations of existing police data, adding to the evidence base and informing local and national decision-making. The method may create additional benefits for data collectors and communities, help design and assess road safety interventions and support advocacy for improved routine police data.

2.
J Transp Health ; 24: 101337, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35309548

RESUMO

Introduction: Road traffic injuries are a major but neglected global challenge. There are high and rising rates of road traffic injuries in Nepal. Most of the studies reporting these injuries in Nepal have used quantitative methods to describe the injury burden. Little qualitative research has been conducted to describe the contexts and social processes surrounding crashes, or public perceptions of risks and potential solutions. The aim of this study was to explore the perceptions of road dangers from communities living alongside a major highway in Nepal. Methods: In this qualitative study we recruited members of neighbourhood development committees and a mother's group to take part in focus groups exploring their views. Data were audio-recorded, transcribed, translated and analysed thematically. Results: Four focus groups were conducted involving 34 participants aged 24-65. Our study findings highlight the challenges faced by people living near a major highway and their fear of getting injured on the road. Five themes that emerged were: risky behaviours of road users, infrastructure for safer behaviour, poor condition and maintenance of roads and vehicles, limited adherence and enforcement of traffic laws, and the need for road safety awareness programmes. Conclusion: The community groups expressed multiple concerns regarding the safety of members of their communities and lived-in fear of death and injury on the road where they lived. There is an urgent need for government agencies to understand these concerns and to take action in relating to infrastructure provision, regulation and behavioural change programmes.

3.
J Sch Health ; 92(8): 765-773, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35253225

RESUMO

BACKGROUND: The COVID-19 pandemic caused an unprecedented move to emergency remote learning around the world, leading to increased digital screen time for children and adolescents. This review highlights the potential risk of increased screen time to the eye and general health and makes recommendations to mitigate the risks posed. METHODS: A narrative review of evidence of increased digital time during the COVID-19 pandemic, the risks linked to increased screen time and offer possible steps to mitigate these in students. RESULTS: Digital screen time was found to have increased for children and adolescents in all the studies examined during the pandemic and data suggests that this has an impact on eye and general health. We discuss the associated risk factors and adverse outcomes associated with increased digital screen time. CONCLUSIONS: This review offers evidence of increased digital time, highlights some of the well-known and not so well-known risks linked to increased screen time, and offers possible steps to mitigate these in children and adolescents during the pandemic, as well as offering schools and parents strategies to support the eye health of children and adolescents post-pandemic. We discuss a number of interventions to reduce the risk of eye strain, myopia, obesity, and related diseases that have been shown to be linked to increased digital screen time.


Assuntos
COVID-19 , Tempo de Tela , Adolescente , COVID-19/prevenção & controle , Criança , Humanos , Pandemias/prevenção & controle , Pais , Fatores de Risco
4.
Traffic Inj Prev ; 23(2): 79-84, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35030051

RESUMO

OBJECTIVE: Accurate road crash reporting is essential for evaluating road safety interventions and plans. Under-reporting of road traffic crashes, injuries, and fatalities in police records has been widely described. The aim of this study was to apply and evaluate a community crash recording system, and assess the quality of the data in comparison with traffic police data in Nepal. METHODS: The crash data collection methodology involved recruiting Local Record Keepers working and living at locations known to be at a high risk of crashes. Six shopkeepers were recruited at three crash locations and trained to complete collision incident forms for crashes occurring over one year on the section of road visible from their premises. Manual traffic volume and pedestrian counts, and spot speed surveys were conducted. Data were compared with District police records for the same period and locations. RESULTS: Over 12 months, 110 crashes were recorded by the Local Record Keepers. Of these, 70 resulted in 145 injuries (5 fatalities, 62 severe, and 78 minor injuries), while 40 resulted only in property damage. Comparable police data recorded 23 crashes, of which 18 crashes resulted in 27 injuries (8 fatalities, 13 serious, and 6 minor injuries), and 5 crashes in property damage only. The difference in recording of fatal and serious injuries was statistically significant (χ2(1) = 19.94, p < 0.001). The police reporting rate was highest for fatalities (62.5%) but only 11.6% and 7.1% for property damage cases and minor injuries respectively, and 3.8% for single-vehicle crashes. Compared to the Local Record Keeper data, the overall police crash reporting rate was 19.7%. CONCLUSIONS: Local Record Keepers' recording of road traffic crashes and casualties is feasible and provides a more complete record than routinely collected police data. The low reporting rate in the police records of minor injury, property damage, and single-vehicle crashes suggest significant underestimation and bias in the reporting of the actual burden of road traffic crashes. Local Record Keeper recording is a viable method for validating police reports.


Assuntos
Acidentes de Trânsito , Ferimentos e Lesões , Humanos , Nepal/epidemiologia , Polícia , Inquéritos e Questionários , Ferimentos e Lesões/epidemiologia
5.
Int J Inj Contr Saf Promot ; 29(2): 217-225, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34590542

RESUMO

Road traffic injuries in Nepal are increasing despite being largely preventable. Little evidence exists regarding the barriers and facilitators to a safer road system. This study aimed to explore the perspectives of professionals whose jobs had the potential to influence road safety in Nepal regarding challenges and potential solutions. Semi-structured interviews with eight informants from diverse roles were analysed thematically. Three themes were identified: Modifying behaviours of road users; Road planning, construction and maintenance; and the Governance of roads and traffic. All participants considered the primary cause of crashes to be the negligent behavior of the road users, suggesting that improved knowledge would influence their decisions. Poor road design, building and maintenance, together with poor vehicle standards, and lack of investment and enforcement of existing road safety legislation, needed to be addressed through greater coordination of the agencies. The study identified a range of areas for future inquiry and action.


Assuntos
Acidentes de Trânsito , Acidentes de Trânsito/prevenção & controle , Humanos , Nepal , Pesquisa Qualitativa
6.
J Transp Health ; 23: 101247, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34976734

RESUMO

BACKGROUND: Heavy goods vehicle drivers are an influential driving population in Nepal, with over 90% of goods in the country are transported by road. Due to the time spent on the road, drivers have long periods of exposure to the risk of crash involvement. The study explores the perceptions and experiences of heavy goods vehicle drivers and representatives from their professional association regarding road danger. METHODS: We conducted semi-structured interviews with fifteen heavy goods vehicle drivers regularly driving on the East-West highway of Makwanpur District, Nepal. A focus group was conducted with eleven members from a major transportation entrepreneur's association in Nepal. The focus group and interviews were audio-recorded, transcribed, translated, and analyzed using thematic analysis. RESULTS: Four themes were developed- assumptions of blame; perceptions of safety culture in the trucking industry; influence of road infrastructure; and behaviours of road users. The road and traffic environment, enforcement, and the safety culture in the heavy vehicle industry not only influenced the attitudes of the road users towards traffic safety but also legitimized and encouraged behaviours that affect safety. General and industry-related road safety improvements suggested by participants included: making provision for heavy good vehicles parking areas, separating the highway with a median strip, improving crash investigation capacity, conducting road safety awareness and training programs, strictly enforcing the speed limit and laws about driving under the influence of alcohol/drugs, and formulating strategies to create a safe, supportive working environment in the heavy vehicle industry. CONCLUSION: Heavy goods vehicle drivers and members of the professional association can provide rich information regarding the barriers and facilitators of road risk in Nepal. Their perceptions and opinions can contribute to devising interventions at individual, societal, organizational, and governmental levels, and inform efforts to develop a positive safety culture within the heavy vehicle transport industry.

7.
Inj Prev ; 26(1): 85-88, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31302608

RESUMO

Twenty miles per hour (32 km/hour) or 30 km/hour speed limits represent a potential strategy to reduce urban road injuries and are becoming increasingly widespread. However, no study has conducted a robust evaluation of the effects of city-wide 20 mph speed limits on road injuries. This study reports the effects of such an intervention, based on a natural experiment that took place in Bristol, UK. Based on a stepped-wedge design using count data, negative binomial regressions showed that between 2008 and 2016, the 20 mph speed limit intervention was associated with a city-level reduction of fatal injuries of around 63% (95% CI 2% to 86%), controlling for trends over time and areas. There was also a general trend of reduction of the total number of injuries at city level and in 20 mph roads. These findings highlight the potential benefits of city-wide 20 mph speed limits. We hypothesise that this city-wide approach may encourage a general behaviour change in drivers that, in turn, may contribute to reducing injuries across the city.


Assuntos
Acidentes de Trânsito/prevenção & controle , Condução de Veículo/legislação & jurisprudência , Acidentes de Trânsito/estatística & dados numéricos , Cidades , Humanos , Reino Unido/epidemiologia
8.
J Biol Chem ; 294(52): 20148-20163, 2019 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-31719147

RESUMO

Activation and suppression of the complement system compete on every serum-exposed surface, host or foreign. Potentially harmful outcomes of this competition depend on surface molecules through mechanisms that remain incompletely understood. Combining surface plasmon resonance (SPR) with atomic force microscopy (AFM), here we studied two complement system proteins at the single-molecule level: C3b, the proteolytically activated form of C3, and factor H (FH), the surface-sensing C3b-binding complement regulator. We used SPR to monitor complement initiation occurring through a positive-feedback loop wherein surface-deposited C3b participates in convertases that cleave C3, thereby depositing more C3b. Over multiple cycles of flowing factor B, factor D, and C3 over the SPR chip, we amplified C3b from ∼20 to ∼220 molecules·µm-2 AFM revealed C3b clusters of up to 20 molecules and solitary C3b molecules deposited up to 200 nm away from the clusters. A force of 0.17 ± 0.02 nanonewtons was needed to pull a single FH molecule, anchored to the AFM probe, from its complex with surface-attached C3b. The extent to which FH molecules stretched before detachment varied widely among complexes. Performing force-distance measurements with FH(D1119G), a variant lacking one of the C3b-binding sites and causing atypical hemolytic uremic syndrome, we found that it detached more uniformly and easily. In further SPR experiments, KD values between FH and C3b on a custom-made chip surface were 5-fold tighter than on commercial chips and similar to those on erythrocytes. These results suggest that the chemistry at the surface on which FH acts drives conformational adjustments that are functionally critical.


Assuntos
Complemento C3b/metabolismo , Fator H do Complemento/metabolismo , Microscopia de Força Atômica , Ressonância de Plasmônio de Superfície , Ativação do Complemento , Complemento C3b/química , Complemento C3d/química , Complemento C3d/metabolismo , Fator H do Complemento/química , Humanos , Proteínas Imobilizadas/química , Proteínas Imobilizadas/metabolismo , Cinética , Ligação Proteica
9.
Angew Chem Int Ed Engl ; 57(30): 9377-9381, 2018 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-29870577

RESUMO

Traditional methods to prepare chiral surfaces involve either the adsorption of a chiral molecule onto an achiral surface, or adsorption of a species that forms a chiral template creating lattices with long range order. To date only limited alternative strategies to prepare chiral surfaces have been studied. In this manuscript a "bottom-up" approach is developed that allows the preparation of chiral surfaces by direct enantioselective organocatalytic reactions on a functionalized silicon oxide supported self-assembled monolayer (SAM). The efficient catalytic generation of enantiomerically enriched organic surfaces is achieved using a commercially available homogeneous isothiourea catalyst that promotes an enantioselective Michael-lactonization process upon a silicon-oxide supported SAM functionalized with a reactive trifluoroenone group. Chiral atomic force microscopy (χ-AFM) is used to probe the enantiomeric enrichment of the organic films by measurement of the force distributions arising from interaction of d- or l-cysteine-modified AFM tips and the organic films.

11.
BJU Int ; 121(2): 217-224, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28594471

RESUMO

OBJECTIVE: To analyse the impact of centralisation of radical cystectomy (RC) provision for bladder cancer in England, on postoperative mortality, length of stay (LoS), complications and re-intervention rates, from implementation of centralisation from 2003 until 2014. In 2002, UK policymakers introduced the 'Improving Outcomes Guidance' (IOG) for urological cancers after a global cancer surgery commission identified substantial shortcomings in provision of care of RCs. One key recommendation was centralisation of RCs to high-output centres. No study has yet robustly analysed the changes since the introduction of the IOG, to assess a national healthcare system that has mature data on such institutional transformation. PATIENTS AND METHODS: RCs performed for bladder cancer in England between 2003/2004 and 2013/2014 were analysed from Hospital Episode Statistics (HES) data. Outcomes including 30-day, 90-day, and 1-year all-cause postoperative mortality; median LoS; complication and re-intervention rates, were calculated. Multivariable statistical analysis was undertaken to describe the relationship between each surgeon and the providers' annual case volume and mortality. RESULTS: In all, 15 292 RCs were identified. The percentage of RCs performed in discordance with the IOG guidelines reduced from 65% to 12.4%, corresponding with an improvement in 30-day mortality from 2.7% to 1.5% (P = 0.024). Procedures adhering to the IOG guidelines had better 30-day mortality (2.1% vs 2.9%; P = 0.003) than those that did not, and better 1-year mortality (21.5% vs 25.6%; P < 0.001), LoS (14 vs 16 days; P < 0.001), and re- intervention rates (30.0% vs 33.6%; P < 0.001). Each single extra surgery per centre reduced the odds of death at 30 days by 1.5% (odds ratio [OR] 0.985, 95% confidence interval [CI] 0.977-0.992) and 1% at 1 year (OR 0.990, 95% CI 0.988-0.993), and significantly reduced rates of re-intervention. CONCLUSION: Centralisation has been implemented across England since the publication of the IOG guidelines in 2002. The improved outcomes shown, including that a single extra procedure per year per centre can significantly reduce mortality and re-intervention, may serve to offer healthcare planners an evidence base to propose new guidance for further optimisation of surgical provision, and hope for other healthcare systems that such widespread institutional change is achievable and positive.


Assuntos
Cistectomia/estatística & dados numéricos , Atenção à Saúde/organização & administração , Cirurgiões/estatística & dados numéricos , Neoplasias da Bexiga Urinária/cirurgia , Idoso , Cistectomia/efeitos adversos , Cistectomia/mortalidade , Bases de Dados Factuais , Inglaterra , Feminino , Fidelidade a Diretrizes/estatística & dados numéricos , Hospitais com Alto Volume de Atendimentos/estatística & dados numéricos , Humanos , Tempo de Internação/tendências , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Complicações Pós-Operatórias/etiologia , Guias de Prática Clínica como Assunto , Melhoria de Qualidade/tendências , Reoperação/tendências , Neoplasias da Bexiga Urinária/mortalidade
12.
Beilstein J Nanotechnol ; 7: 492-500, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27335740

RESUMO

Micro- and nanocantilevers are employed in atomic force microscopy (AFM) and in micro- and nanoelectromechanical systems (MEMS and NEMS) as sensing elements. They enable nanomechanical measurements, are essential for the characterization of nanomaterials, and form an integral part of many nanoscale devices. Despite the fact that numerous methods described in the literature can be applied to determine the static flexural spring constant of micro- and nanocantilever sensors, experimental techniques that do not require contact between the sensor and a surface at some point during the calibration process are still the exception rather than the rule. We describe a noncontact method using a microfluidic force tool that produces accurate forces and demonstrate that this, in combination with a thermal noise spectrum, can provide the static flexural spring constant for cantilever sensors of different geometric shapes over a wide range of spring constant values (≈0.8-160 N/m).

13.
Langmuir ; 32(13): 3130-8, 2016 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-27015037

RESUMO

Tailoring the functionality of self-assembled monolayers (SAMs) can be achieved either by depositing prefunctionalized molecules with the appropriate terminal groups or by chemical modification of an existing SAM in situ. The latter approach is particularly advantageous to allow for diversity of surface functionalization from a single SAM and if the incorporation of bulky groups is desired. In the present study an organocatalytic isothiourea-mediated Michael addition-lactonization process analogous to a previously reported study in solution is presented. An achiral isothiourea, 3,4-dihydro-2H-pyrimido[2,1-b]benzothiazole (DHPB), promotes the intermolecular Michael addition-lactonization of a trifluoromethylenone terminated SAM and a variety of arylacetic acids affording C(6)-trifluoromethyldihydropyranones tethered to the surface. X-ray photoelectron spectroscopy, atomic force microscopy, contact angle, and ellipsometry analysis were conducted to confirm the presence of the substituted dihydropyranone. A model study of this approach was also performed in solution to probe the reaction diastereoselectivity as it cannot be measured directly on the surface.

14.
Cochrane Database Syst Rev ; (12): CD010415, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26661390

RESUMO

BACKGROUND: Cycling is an attractive form of transport. It is beneficial to the individual as a form of physical activity that may fit more readily into an individual's daily routine, such as for cycling to work and to the shops, than other physical activities such as visiting a gym. Cycling is also beneficial to the wider community and the environment as a result of fewer motorised journeys. Cyclists are seen as vulnerable road users who are frequently in close proximity to larger and faster motorised vehicles. Cycling infrastructure aims to make cycling both more convenient and safer for cyclists. This review is needed to guide transport planning. OBJECTIVES: To:1. evaluate the effects of different types of cycling infrastructure on reducing cycling injuries in cyclists, by type of infrastructure;2. evaluate the effects of cycling infrastructure on reducing the severity of cycling injuries in cyclists;3. evaluate the effects of cycling infrastructure on reducing cycling injuries in cyclists with respect to age, sex and social group. SEARCH METHODS: We ran the most recent search on 2nd March 2015. We searched the Cochrane Injuries Group Specialised Register, CENTRAL (The Cochrane Library), MEDLINE (OvidSP), Embase Classic + Embase(OvidSP), PubMed and 10 other databases. We searched websites, handsearched conference proceedings, screened reference lists of included studies and previously published reviews and contacted relevant organisations. SELECTION CRITERIA: We included randomised controlled trials, cluster randomised controlled trials, controlled before-after studies, and interrupted time series studies which evaluated the effect of cycling infrastructure (such as cycle lanes, tracks or paths, speed management, roundabout design) on cyclist injury or collision rates. Studies had to include a comparator, that is, either no infrastructure or a different type of infrastructure. We excluded studies that assessed collisions that occurred as a result of competitive cycling. DATA COLLECTION AND ANALYSIS: Two review authors examined the titles and abstracts of papers obtained from searches to determine eligibility. Two review authors extracted data from the included trials and assessed the risk of bias. We carried out a meta-analysis using the random-effects model where at least three studies reported the same intervention and outcome. Where there were sufficient studies, as a secondary analysis we accounted for changes in cyclist exposure in the calculation of the rate ratios. We rated the quality of the evidence as 'high', 'moderate', 'low' or 'very low' according to the GRADE approach for the installation of cycle routes and networks. MAIN RESULTS: We identified 21 studies for inclusion in the review: 20 controlled before-after (CBA) studies and one interrupted time series (ITS) study. These evaluated a range of infrastructure including cycle lanes, advanced stop lines, use of colour, cycle tracks, cycle paths, management of the road network, speed management, cycle routes and networks, roundabout design and packages of measures. No studies reported medically-attended or self-reported injuries. There was no evidence that cycle lanes reduce the rate of cycle collisions (rate ratio 1.21, 95% CI 0.70 to 2.08). Taking into account cycle flow, there was no difference in collisions for cyclists using cycle routes and networks compared with cyclists not using cycle routes and networks (RR 0.40, 95% CI 0.15 to 1.05). There was statistically significant heterogeneity between the studies (I² = 75%, Chi² = 8.00 df = 2, P = 0.02) for the analysis adjusted for cycle flow. We judged the quality of the evidence regarding cycle routes and networks as very low and we are very uncertain about the estimate. These analyses are based on findings from CBA studies.From data presented narratively, the use of 20 mph speed restrictions in urban areas may be effective at reducing cyclist collisions. Redesigning specific parts of cycle routes that may be particularly busy or complex in terms of traffic movement may be beneficial to cyclists in terms of reducing the risk of collision. Generally, the conversion of intersections to roundabouts may increase the number of cycle collisions. In particular, the conversion of intersections to roundabouts with cycle lanes marked as part of the circulating carriageway increased cycle collisions. However, the conversion of intersections with and without signals to roundabouts with cycle paths may reduce the odds of collision. Both continuing a cycle lane across the mouth of a side road with a give way line onto the main road, and cycle tracks, may increase the risk of injury collisions in cyclists. However, these conclusions are uncertain, being based on a narrative review of findings from included studies. There is a lack of evidence that cycle paths or advanced stop lines either reduce or increase injury collisions in cyclists. There is also insufficient evidence to draw any robust conclusions concerning the effect of cycling infrastructure on cycling collisions in terms of severity of injury, sex, age, and level of social deprivation of the casualty.In terms of quality of the evidence, there was little matching of intervention and control sites. In many studies, the comparability of the control area to the intervention site was unclear and few studies provided information on other cycling infrastructures that may be in place in the control and intervention areas. The majority of studies analysed data routinely collected by organisations external to the study team, thus reducing the risk of bias in terms of systematic differences in assessing outcomes between the control and intervention groups. Some authors did not take regression-to-mean effects into account when examining changes in collisions. Longer data collection periods pre- and post-installation would allow for regression-to-mean effects and also seasonal and time trends in traffic volume to be observed. Few studies adjusted cycle collision rates for exposure. AUTHORS' CONCLUSIONS: Generally, there is a lack of high quality evidence to be able to draw firm conclusions as to the effect of cycling infrastructure on cycling collisions. There is a lack of rigorous evaluation of cycling infrastructure.


Assuntos
Acidentes de Trânsito/prevenção & controle , Ciclismo/lesões , Planejamento Ambiental , Segurança , Estudos Controlados Antes e Depois , Humanos , Análise de Séries Temporais Interrompida , Avaliação de Resultados em Cuidados de Saúde , Índices de Gravidade do Trauma
15.
Accid Anal Prev ; 73: 100-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25195093

RESUMO

The proximity and speed of motor traffic passing cyclists in non-separated conditions may be so close and so great as to cause discomfort. A variety of road design and driver behaviour factors may affect overtaking speeds and distances. The investigation presented in this paper builds on previous research and fills gaps in that research by considering the presence of cycle lanes on 20 mph and 30 mph roads, different lane widths, different lane markings, vehicle type, vehicle platooning and oncoming traffic. Data were collected from a bicycle ridden a distance of one metre from the kerb fitted with an ultrasonic distance detector and forward and sideways facing cameras. Reduced overtaking speeds correlate with narrower lanes, lower speed limits, and the absence of centre-line markings. Drivers passed slower if driving a long vehicle, driving in a platoon, and when approaching vehicles in the opposing carriageway were within five seconds of the passing point. Increased passing distances were found where there were wider or dual lane roads, and in situations where oncoming vehicles were further away and not in a platoon. In mixed traffic conditions, cyclists will be better accommodated by wider cross-sections, lower speed limits and the removal of the centre-line marking.


Assuntos
Condução de Veículo , Ciclismo , Planejamento Ambiental , Acidentes de Trânsito/prevenção & controle , Condução de Veículo/normas , Condução de Veículo/estatística & dados numéricos , Comportamento Perigoso , Humanos
16.
Accid Anal Prev ; 72: 411-21, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25146495

RESUMO

Increased frequency of cycle journeys has led to an escalation in collisions between cyclists and vehicles, particularly at shared junctions. Risks associated with passing decisions have been shown to influence cyclists' behavioural intentions. The current study extended this research by linking not only risk perception but also attention allocation (via tracking the eye movements of twenty cyclists viewing junction approaches presented on video) to behavioural intentions. These constructs were measured in a variety of contexts: junctions featuring cycle lanes, large vs. small vehicles and differing kerb to vehicle distances). Overall, cyclists devoted the majority of their attention to the nearside (side closest to kerb) of vehicles, and perceived near and offside (side furthest from kerb) passing as most risky. Waiting behind was the most frequent behavioural intention, followed by nearside and then offside passing. While cycle lane presence did not affect behaviour, it did lead to nearside passing being perceived as less risky, and to less attention being devoted to the offside. Large vehicles led to increased risk perceived with passing, and more attention directed towards the rear of vehicles, with reduced offside passing and increased intentions to remain behind the vehicle. Whether the vehicle was large or small, nearside passing was preferred around 30% of the time. Wide kerb distances increased nearside passing intentions and lower associated perceptions of risk. Additionally, relationships between attention and both risk evaluations and behaviours were observed. These results are discussed in relation to the cyclists' situational awareness and biases that various contextual factors can introduce. From these, recommendations for road safety and training are suggested.


Assuntos
Atenção , Ciclismo , Planejamento Ambiental , Veículos Automotores , Acidentes de Trânsito , Adulto , Medições dos Movimentos Oculares , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Percepção , Risco , Gravação em Vídeo
17.
Nanotechnology ; 25(22): 225701, 2014 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-24807706

RESUMO

A method suitable for the calibration of the spring constants of all torsional and lateral eigenmodes of micro- and nanocantilever sensors is described. Such sensors enable nanomechanical measurements and the characterization of nanomaterials, for example with atomic force microscopy. The method presented involves the interaction of a flow of fluid from a microchannel with the cantilever beam. Forces imparted by the flow cause the cantilever to bend and induce a measurable change of the torsional and lateral resonance frequencies. From the frequency shifts the cantilever spring constants can be determined. The method does not involve physical contact between the cantilever or its tip and a hard surface. As such it is non-invasive and does not risk damage to the cantilever. Experimental data is presented for two rectangular microcantilevers with fundamental flexural spring constants of 0.046 and 0.154 N m(-1). The experimentally determined torsional stiffness values are compared with those obtained by the Sader method. We demonstrate that the torsional spring constants can be readily calibrated using the method with an accuracy of around 15%.

18.
Nanotechnology ; 24(6): 065704, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23340257

RESUMO

A method for the simultaneous calibration of the spring constants of all flexural modes of microcantilevers is presented. It is based on a flow of gas from a microchannel that interacts with the microcantilever. The gas flow causes a measurable shift in the resonance frequencies of thermal noise spectra of the flexural modes. From the magnitude of the frequency shifts of the individual modes the spring constants can be determined with high accuracy and precision. The method is non-invasive and does not risk damage to the cantilever. Experimental data are presented for several V-shaped and rectangular cantilevers with nominal fundamental spring constants in the range of 0.03-1.75 N m(-1). The spring constants of the fundamental modes compare favorably to those obtained using the Sader method. The higher modes of oscillation are readily calibrated with experimental uncertainties of 5-10%.

19.
Rev Sci Instrum ; 82(3): 035108, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21456790

RESUMO

Micro- and nanocantilevers are increasingly employed as mass sensors. Most studies consider the first flexural mode and adsorbed masses that are either discretely attached or homogeneously distributed along the entire length of the cantilever. We derive general expressions that allow for the determination of the total attached mass with any mass distribution along the cantilever length and all flexural modes. The expressions are valid for all cantilevers whose flexural deflection can be described by a one-dimensional function. This approach includes the most common types of microcantilevers, namely, rectangular, picket, and V-shaped. The theoretical results are compared with experimental data up to the fourth flexural mode obtained from thermal noise spectra of rectangular and V-shaped cantilevers.

20.
Accid Anal Prev ; 42(1): 159-65, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19887156

RESUMO

An experiment collected proximity data of motor traffic overtaking cycle traffic on roads with and without cycle lanes using an instrumented bicycle. The work enhances previous research which has considered the riding position of the cyclist and whether or not the cyclist was helmeted, while controlling for vehicle type. The analysis shows that significantly wider passing distances are adopted by motorists in the condition without a 1.45 m cycle lane, with posted speed limits of 40 mph and 50 mph with a 9.5m wide carriageway. These findings were not replicated for a similar width road with a posted speed limit of 30 mph and a 1.3m cycle lane. The results suggest that in the presence of a cycle lane, drivers may be driving within the confines of their own marked lane with less recognition being given to the need to provide a comfortable passing distance to cycle traffic in the adjacent cycle lane.


Assuntos
Acidentes de Trânsito , Condução de Veículo , Ciclismo , Acidentes de Trânsito/prevenção & controle , Planejamento Ambiental , Humanos , Assunção de Riscos
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