Driver Behavior as a Function of Ambient Light and Road Geometry

OBJECTIVES To determine how ambient light (day versus night) and road geometry affect driving behavior,especially the speeds that drivers choose when not constrained by lead vehicles.METHODSRecently, it has become technically easier to observe how people drive b offering them longtermuse of highly instrumented vehicles. Much of this type of work has been done in connectionwith large-scale field operational tests (FOTs) of various innovative vehicle systems. Theinformation obtained is in many ways complementary to information from observation of traffic.Traffic observation often provides information about a large number of drivers, but at a relativelycoarse level and in a spatially and temporally limited context (i.e., observing how a large numberof drivers negotiate a particular intersection). In contrast, long-term use of highly instrumentedvehicles is more restricted in terms of how many drivers can be observed, although the feasiblenumbers are now reasonably high. On the positive side, data from instrumented vehicles canoffer very detailed information about driving behavior over many miles and many days.In this paper, we present results from a database of driving behavior that was derived from arecent FOT for an adaptive cruise control (ACC) system (although the data used here are all fromphases of the study that involved only normal vehicle equipment). The FOT involved tenidentical cars that were instrumented for a variety of types of data. The most important data forpresent purposes were: speed, yaw rate, location from the Global Positioning System (GPS), andpresence or absence of a lead vehicle within about 100 m based on the forward-looking sensorsof the ACC system. The instrumented cars were driven by a total of 108 participants, each ofwhom was given a car to use as his or her own vehicle in normal driving for either two or fiveweeks. The participants were sampled from licensed drivers in southeastern Michigan, andrepresented a wide range of age and driving experience.RESULTSResults will be reported in terms of speed as a function of horizontal road curvature in light anddark conditions, and as a function of driver age and gender, all for situations in which there is nolead vehicle within about 100 m. CONCLUSIONSCurrent evidence about headlighting suggests that drivers’ ability to see and negotiate theroadway is virtually unaffected by differences in ambient light, although their ability to perceiveand avoid objects on the road, such as pedestrians, is greatly reduced when headlamps are themain source of light. There is also evidence that drivers do not markedly reduce their speed inconditions of low ambient light. The current analysis allows us to determine how drivers react tospecific road geometries in light and dark conditions. This has implications for how well drivers’perceptual abilities match their driving behavior, and also for assessing the potential benefit of avariety of innovative headlighting systems that are currently being designed to adapt in variousways to vehicle speed and road geometry

Driver Behavior as a Function of Ambient Light and Road Geometry

OBJECTIVES To determine how ambient light (day versus night) and road geometry affect driving behavior,especially the speeds that drivers choose when not constrained by lead vehicles.METHODSRecently, it has become technically easier to observe how people drive b offering them longtermuse of highly instrumented vehicles. Much of this type of work has been done in connectionwith large-scale field operational tests (FOTs) of various innovative vehicle systems. Theinformation obtained is in many ways complementary to information from observation of traffic.Traffic observation often provides information about a large number of drivers, but at a relativelycoarse level and in a spatially and temporally limited context (i.e., observing how a large numberof drivers negotiate a particular intersection). In contrast, long-term use of highly instrumentedvehicles is more restricted in terms of how many drivers can be observed, although the feasiblenumbers are now reasonably high. On the positive side, data from instrumented vehicles canoffer very detailed information about driving behavior over many miles and many days.In this paper, we present results from a database of driving behavior that was derived from arecent FOT for an adaptive cruise control (ACC) system (although the data used here are all fromphases of the study that involved only normal vehicle equipment). The FOT involved tenidentical cars that were instrumented for a variety of types of data. The most important data forpresent purposes were: speed, yaw rate, location from the Global Positioning System (GPS), andpresence or absence of a lead vehicle within about 100 m based on the forward-looking sensorsof the ACC system. The instrumented cars were driven by a total of 108 participants, each ofwhom was given a car to use as his or her own vehicle in normal driving for either two or fiveweeks. The participants were sampled from licensed drivers in southeastern Michigan, andrepresented a wide range of age and driving experience.RESULTSResults will be reported in terms of speed as a function of horizontal road curvature in light anddark conditions, and as a function of driver age and gender, all for situations in which there is nolead vehicle within about 100 m. CONCLUSIONSCurrent evidence about headlighting suggests that drivers’ ability to see and negotiate theroadway is virtually unaffected by differences in ambient light, although their ability to perceiveand avoid objects on the road, such as pedestrians, is greatly reduced when headlamps are themain source of light. There is also evidence that drivers do not markedly reduce their speed inconditions of low ambient light. The current analysis allows us to determine how drivers react tospecific road geometries in light and dark conditions. This has implications for how well drivers’perceptual abilities match their driving behavior, and also for assessing the potential benefit of avariety of innovative headlighting systems that are currently being designed to adapt in variousways to vehicle speed and road geometry

Assessment of the Mobilizable Vector Plasmids pSUP202 and pSUP404.2 as Genetic Tools for the Predatory Bacterium Bdellovibrio bacteriovorus

Bdellovibrio and like organisms (BALOs) form the group of predatory bacteria which require Gram-negative bacteria as prey. Genetic studies with Bdellovibrio bacteriovorus can be performed with vectors which are introduced into the predator via conjugation. The usefulness of the two vectors pSUP202 and pSUP404.2 as genetic tools were assessed. Both vectors were transferable into B. bacteriovorus by conjugative matings with an Escherichia coli K12 strain as donor. The transfer frequency was higher for vector pSUP404.2 (approx. 10−1–10−4) as for pSUP202 (approx. 10−5–10−6). Vector pSUP202 with a pMB1 origin is unstable in the predatory bacterium, whereas pSUP404.2 is stably maintained in the absence of selective antibiotics. pSUP404.2 harbors two plasmid replicons, the p15A ori and the RSF1010 replication region The copy number of pSUP404.2 was determined by quantitative PCR in B. bacteriovorus and averages seven copies per genome. pSUP404.2 harbors two resistance genes (chloramphenicol and kanamycin) which can be used for cloning either by selection for transconjugants or by insertional inactivation

PAD4-Mediated Neutrophil Extracellular Trap Formation Is Not Required for Immunity against Influenza Infection

During an inflammatory response, neutrophils migrate to the site of infection where they can kill invading pathogens by phagocytosis, secretion of anti-microbicidal mediators or the release of neutrophil extracellular traps (NETs). NETs are specialized anti-microbial structures comprised of decondensed chromatin decorated with microbicidal agents. Increased amount of NETs have been found in patients suffering from the chronic lung inflammatory disease cystic fibrosis, correlating with increased severity of pulmonary obstruction. Furthermore, acute lung inflammation during influenza A infection is characterized by a massive influx of neutrophils into the lung. The role of NETs during virus-mediated lung inflammation is unknown. Peptidylarginine deiminase 4 (PAD4)-mediated deimination of histone H3 and H4 is required for NET formation. Therefore, we generated a PAD4-deficient mouse strain that has a striking inability to form NETs. These mice were infected with influenza A/WSN, and the disease was monitored at the level of leukocytic lung infiltration, lung pathology, viral replication, weight loss and mortality. PAD4 KO fared comparable to WT mice in all the parameters tested, but they displayed slight but statistically different weight loss kinetics during infection that was not reflected in enhanced survival. Overall, we conclude that PAD4-mediated NET formation is dispensable in a mouse model of influenza A infection

Genetic Organisation, Mobility and Predicted Functions of Genes on Integrated, Mobile Genetic Elements in Sequenced Strains of Clostridium difficile

Background: Clostridium difficile is the leading cause of hospital-associated diarrhoea in the US and Europe. Recently the incidence of C. difficile-associated disease has risen dramatically and concomitantly with the emergence of 'hypervirulent' strains associated with more severe disease and increased mortality. C. difficile contains numerous mobile genetic elements, resulting in the potential for a highly plastic genome. In the first sequenced strain, 630, there is one proven conjugative transposon (CTn), Tn5397, and six putative CTns (CTn1, CTn2 and CTn4-7), of which, CTn4 and CTn5 were capable of excision. In the second sequenced strain, R20291, two further CTns were described.Results: CTn1, CTn2 CTn4, CTn5 and CTn7 were shown to excise from the genome of strain 630 and transfer to strain CD37. A putative CTn from R20291, misleadingly termed a phage island previously, was shown to excise and to contain three putative mobilisable transposons, one of which was capable of excision. In silico probing of C. difficile genome sequences with recombinase gene fragments identified new putative conjugative and mobilisable transposons related to the elements in strains 630 and R20291. CTn5-like elements were described occupying different insertion sites in different strains, CTn1-like elements that have lost the ability to excise in some ribotype 027 strains were described and one strain was shown to contain CTn5-like and CTn7-like elements arranged in tandem. Additionally, using bioinformatics, we updated previous gene annotations and predicted novel functions for the accessory gene products on these new elements.Conclusions: The genomes of the C. difficile strains examined contain highly related CTns suggesting recent horizontal gene transfer. Several elements were capable of excision and conjugative transfer. The presence of antibiotic resistance genes and genes predicted to promote adaptation to the intestinal environment suggests that CTns play a role in the interaction of C. difficile with its human host

Direct Visualization of Peptide/MHC Complexes at the Surface and in the Intracellular Compartments of Cells Infected In Vivo by Leishmania major

Protozoa and bacteria infect various types of phagocytic cells including macrophages, monocytes, dendritic cells and eosinophils. However, it is not clear which of these cells process and present microbial antigens in vivo and in which cellular compartments parasite peptides are loaded onto Major Histocompatibility Complex molecules. To address these issues, we have infected susceptible BALB/c (H-2d) mice with a recombinant Leishmania major parasite expressing a fluorescent tracer. To directly visualize the antigen presenting cells that present parasite-derived peptides to CD4+ T cells, we have generated a monoclonal antibody that reacts to an antigenic peptide derived from the parasite LACK antigen bound to I-Ad Major Histocompatibility Complex class II molecule. Immunogold electron microscopic analysis of in vivo infected cells showed that intracellular I-Ad/LACK complexes were present in the membrane of amastigote-containing phagosomes in dendritic cells, eosinophils and macrophages/monocytes. In both dendritic cells and macrophages, these complexes were also present in smaller vesicles that did not contain amastigote. The presence of I-Ad/LACK complexes at the surface of dendritic cells, but neither on the plasma membrane of macrophages nor eosinophils was independently confirmed by flow cytometry and by incubating sorted phagocytes with highly sensitive LACK-specific hybridomas. Altogether, our results suggest that peptides derived from Leishmania proteins are loaded onto Major Histocompatibility Complex class II molecules in the phagosomes of infected phagocytes. Although these complexes are transported to the cell surface in dendritic cells, therefore allowing the stimulation of parasite-specific CD4+ T cells, this does not occur in other phagocytic cells. To our knowledge, this is the first study in which Major Histocompatibility Complex class II molecules bound to peptides derived from a parasite protein have been visualized within and at the surface of cells that were infected in vivo

Bacterial Toxins as Pathogen Weapons Against Phagocytes

Bacterial toxins are virulence factors that manipulate host cell functions and take over the control of vital processes of living organisms to favor microbial infection. Some toxins directly target innate immune cells, thereby annihilating a major branch of the host immune response. In this review we will focus on bacterial toxins that act from the extracellular milieu and hinder the function of macrophages and neutrophils. In particular, we will concentrate on toxins from Gram-positive and Gram-negative bacteria that manipulate cell signaling or induce cell death by either imposing direct damage to the host cells cytoplasmic membrane or enzymatically modifying key eukaryotic targets. Outcomes regarding pathogen dissemination, host damage and disease progression will be discussed.This work was supported by FEDER funds through Programa Operational Factores de Competitividade - COMPETE and by national funds through FCT - Fundacao para a Ciencia e a Tecnologia (project PTDC/BIA-MIC/3463/2012 FCOMP-01-0124-FEDER-028364; to AV). Research in the groups of Molecular Microbiology and Fish Immunology and Vaccinology is supported by national funds through FCT Fundacao para Ciencia e a Tecnologia/MEC - Ministerio da Educacao e Ciencia and co-funded by FEDER within the partnership agreement: PT2020 related with the research unit number 4293. The Group of Molecular Microbiology also receives support from a Research Grant 2014 by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) (to SS) and the PT2020 research project Infect-ERA/0001/2013 PROANTILIS. AdV received the FCT fellowship SFRH/BPD/95777/2013 by national funds through FCT - Fundacao para a Ciencia e a Tecnologia/MEC - Ministerio da Educacao e Ciencia and co-funded by QREN and POPH (Programa Operational Potential Humano). SS is supported by FCT-Investigator program

Pedestrian Bridge Design and Evaluation in Brimfield, Massachusetts

The purpose of this project was to design three different bridges and select a fourth pre-fabricated option for a 100-foot wide river crossing in Brimfield, MA. Structural designs addressed member sizes, connections, and ADA compliant handrails. AutoCAD and Photoshop were used for modeling and on-site photo simulations. The alternatives were evaluated based on a weighted scale of multiple criteria and engineering logic, before ultimately recommending a bridge to the US Army Corps of Engineers and the Brimfield Trail Committee

Prospective, multicentre observational study of point-of-care ultrasound practice in emergency departments across Australia and New Zealand : the POCUS-ED Registry

Objectives: The present study aimed to describe the characteristics, performance, accuracy and significance of point-of-care ultrasound (POCUS) use in the ED, by utilising an expanded version of the ACEM-mandated special skills placement (SSP) logbook, to develop a novel clinical quality registry. Methods: A prospective, observational study was performed across EDs in Australia and New Zealand over a 12-month period. Trainees undertaking ACEM-approved ultrasound (US) SSPs recorded all US scan interpretations and follow-up imaging reports in an online database. Results: In total, 2647 USs were recorded by 26 special skills trainees across 10 EDs in Australia or New Zealand; of these 2356 scans (89%) were clinically indicated. Overall, 2493 scans (94%) were used for diagnostic assessment, of which 1147 (43%) had abnormal findings. Basic echocardiography, extended Focused Assessment with Sonography in Trauma and right upper quadrant scans were the most commonly used modalities. There were 134 US-guided procedures logged in the registry. Approximately 36% of scans were reported to alter the original provisional diagnosis, whereas in another 37% of cases, POCUS was thought to confirm the original clinical suspicion. The majority of scans (76.5%) entered into the registry were physically reviewed by the SSP supervisor. Conclusions: This multicentred registry provides a detailed description of the current utilisation of POCUS within special skills US placements across EDs in Australia and New Zealand. This data should inform clinical leaders in emergency US to improve both POCUS education and governance around this important tool