Driving Simulator Performance Across the Lifespan: A Preliminary Study

OBJECTIVES Normal aging is associated with decline in abilities that may put an individual at increased riskfor a crash. Older individuals may have slowed processing speed and motor responses, a reduceduseful field of view (Ball et al., 1988), and greater difficulty with mental rotation (Armstrong etal., 1998). Although collision rates increase with age (Transportation Research Board, 1988), ithas been argued that specific age-related functional impairments, and not age itself, put one atrisk (Ball & Owsley, 2003). The goal of this study was to examine the relationship betweenaging and performance on driving simulations assessing specific components of driving—accident avoidance, divided attention, and navigation—and the degree to which they predict onroaddriving performance.METHODSForty control drivers (age 22 to 84; \u3c 50 yo, n = 14; 50-70 yo, n = 13; and \u3e 70 yo, n = 13)completed 3 simulations and an on-road driving evaluation. Exclusion criteria includedneurologic confounds, substance use and psychiatric disorders, as well as abnormalneuropsychological performance (based upon demographically-corrected norms). Thesimulations were presented on a Pentium III PC computer using a 17” monitor at 1280 x 1024resolution, and running STISIM Drive version 2.0 software (Systems Technology, Inc.;Hawthorne, CA). Hardware included a steering wheel, turn signal, and brake/accelerator pedals.The simulations consisted of 1) Advanced Routine and Emergency Driving (ARED), a 15-minute route simulating city/country driving, in which drivers must obey traffic signs, pass cars,and respond to high-risk crash scenarios; 2) Virtual City (VC), in which drivers must navigate toand from a location in a 5 x 5 block simulated city, and 3) Divided Attention, in which driversare to maintain a constant speed and lane position while responding to divided attention tasks inthe corner of the monitor. Participants also completed a 35-minute on-road assessment. Lastly,participants were assessed on a battery of neuropsychological tests. Earlier versions of thesimulations were predictive of on-road driving performance in an HIV-infected cohort (Marcotteet al., 2004). RESULTSThe three groups performed similarly on ARED (crashes, speeding tickets), as well as on the VCtask when the map was oriented to the same direction as the participant. On the other hand, olderparticipants had significantly more difficulty navigating when their orientation on the map wasreversed (e.g., the \u3c 50 group took 1.2 blocks beyond optimum to return from the destination; the50-70 and \u3e 70 years old groups took approximately 7.5 blocks). The three groups performedsimilarly with respect to lane deviation on the Divided Attention task, but the older groups hadincreased variability in speed maintenance, and the oldest group failed to respond to a greaternumber of divided attention stimuli (\u3c 50 yo = .3 (.83), 50-70 yo = 1.0 (1.3), \u3e 70 yo = 3.6 (2.7)).Although only one participant failed the on-road drive (50-70 yo), the percent of driversconsidered marginal or worse increased with age (7% vs. 25% vs. 55%). In a logistic regression,the simulator variables that best discriminated safe vs. marginal on-road came from the DividedAttention task: the number of missed stimuli and speed deviation, both of which require an intactuseful field of view and the shifting of gaze away from the roadway. Age did not enter into amodel that included these variables.CONCLUSIONSIn this study of normal, healthy controls, older participants drove similarly to young-to-middleaged participants on a simulation that most closely approximated real driving. Consistent withcognitive declines seen in normal aging, older participants had greater difficulty on a taskrequiring navigating when map orientation was reversed (perhaps indicative of impairedegocentric spatial abilities), as well as on a measure of driving-related divided attention, witholder participants appearing to allocate more attention to the roadway at the cost of attending andresponding to peripheral cues. Although older drivers had more difficulty during the on-road test,these difficulties were a function of deficits in the ability to divide attention efficiently, ratherthan aging per se.REFERENCESArmstrong, C.L., & Cloud, B. (1998). The emergence of spatial rotation deficits in dementia andnormal aging. Neuropsychology, 12(2), 208-217.Ball, K.K., Beard, B.L., Roenker, D.L., Miller, R.L., & Griggs, D.S. (1988). Age and visualsearch: Expanding the useful field of view. J Opt Soc Am A, 5(12), 2210-2219.Ball, K., & Owsley, C. (2003). Driving competence: It\u27s not a matter of age. J Am Geriatr Soc,51(10), 1499-1501.Marcotte, T.D., Wolfson, T., Rosenthal, T.J., Heaton, R.K., Gonzalez, R., Ellis, R.J., et al.(2004). A multimodal assessment of driving performance in HIV infection. Neurology, 63(8),1417-1422.Transportation Research Board. (1988). Transportation in an Aging Society, Vol 1. Washington,D.C.: National Research Council

Research frontiers for improving our understanding of drought-induced tree and forest mortality

Accumulating evidence highlights increased mortality risks for trees during severe drought, particularly under warmer temperatures and increasing vapour pressure deficit (VPD). Resulting forest die-off events have severe consequences for ecosystem services, biophysical and biogeochemical land–atmosphere processes. Despite advances in monitoring, modelling and experimental studies of the causes and consequences of tree death from individual tree to ecosystem and global scale, a general mechanistic understanding and realistic predictions of drought mortality under future climate conditions are still lacking. We update a global tree mortality map and present a roadmap to a more holistic understanding of forest mortality across scales. We highlight priority research frontiers that promote: (1) new avenues for research on key tree ecophysiological responses to drought; (2) scaling from the tree/plot level to the ecosystem and region; (3) improvements of mortality risk predictions based on both empirical and mechanistic insights; and (4) a global monitoring network of forest mortality. In light of recent and anticipated large forest die-off events such a research agenda is timely and needed to achieve scientific understanding for realistic predictions of drought-induced tree mortality. The implementation of a sustainable network will require support by stakeholders and political authorities at the international level

Eosinophilic pneumonia associated with daptomycin: a case report and a review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Although several studies did not demonstrate that daptomycin may cause significantly higher rates of pulmonary adverse effects when compared with vancomycin or penicillinase-resistant penicillins, there have been a few case reports of severe pulmonary complications associated with daptomycin administration.</p> <p>Case presentation</p> <p>A rare case of eosinophilic pneumonia occurring 10 days after daptomycin administration in a 78-year-old Caucasian man with possible infectious endocarditis is described. He developed new onset fever, up to 38.5°C, with bilateral pulmonary crackles on physical examination and with no signs of severe respiratory failure. A chest computed tomography-scan showed bilateral nodular consolidations with air bronchograms and pleural effusions. Immediate discontinuation of daptomycin was followed by vigorous improvement of clinical signs and symptoms with progressive resolution of pulmonary consolidations a month later.</p> <p>Conclusion</p> <p>Physicians should be aware of this rare but serious complication during daptomycin treatment, and prompt discontinuation of the offending agent, with or without additional supportive treatment, must occur immediately.</p

A pragmatic approach to evaluate alternative indicators to GDP

The serious economic crisis broken out in 2008 highly stressed the limitations of GDP used as a well-being indicator and as a predictive tool for economy. This induced the need to identify new indicators able to link the economic prosperity of a country to aspects of sustainable development and externalities, both positive and negative, in the long run. The aim of this paper is to introduce a structured approach which supports the choice or the construction of alternative indicators to GDP. The starting point is the definition of what a well-being indicator actually should represent according to the Recommendations of the Stiglitz-Sen-Fitoussi Report on the measurement of economic performance and social progress. Then the paper introduces a systematic procedure for the analysis of well-being indicators. The different phases of this procedure entail the checking of indicators technical properties and their effect on the representational efficacy. Finally, some of the most representative well-being indicators drawn from the literature are compared and a detailed application example is propose

Percutaneous coronary revascularization in patients with formerly "refractory angina pectoris in end-stage coronary artery disease" – Not "end-stage" after all

<p>Abstract</p> <p>Background</p> <p>Patients with refractory angina pectoris in end-stage coronary artery disease represent a severe condition with a higher reduction of life-expectancy and quality of life as compared to patients with stable coronary artery disease. It was the purpose of this study to invasively re-evaluate highly symptomatic patients with formerly diagnosed refractory angina pectoris in end-stage coronary artery disease for feasible options of myocardial revascularization.</p> <p>Methods</p> <p>Thirty-four Patients formerly characterized as having end stage coronary artery disease with refractory angina pectoris were retrospectively followed for coronary interventions.</p> <p>Results</p> <p>Of those 34 patients 21 (61.8%) were eventually revascularized with percutaneous interventional revascularization (PCI). Due to complex coronary morphology (angulation, chronic total occlusion) PCI demanded an above-average amount of time (66 ± 42 minutes, range 25–206 minutes) and materials (contrast media 247 ± 209 ml, range 50–750 ml; PCI guiding wires 2.0 ± 1.4, range 1–6 wires). Of PCI patients 7 (33.3%) showed a new lesion as a sign of progression of atherosclerosis. Clinical success rate with a reduction to angina class II or lower was 71.4% at 30 days. Surgery was performed in a total of8 (23.5%) patients with a clinical success rate of 62.5%. Based on an intention-to-treat 2 patients of originally 8 (25%) demonstrated clinical success. Mortality during follow-up (1–18 months) was 4.8% in patients who underwent PCI, 25% in patients treated surgically and 25% in those only treated medically.</p> <p>Conclusion</p> <p>The majority of patients with end-stage coronary artery disease can be treated effectively with conventional invasive treatment modalities. Therefore even though it is challenging and demanding PCI should be considered as a first choice before experimental interventions are considered.</p

Selective Reduction of AMPA Currents onto Hippocampal Interneurons Impairs Network Oscillatory Activity

Reduction of excitatory currents onto GABAergic interneurons in the forebrain results in impaired spatial working memory and altered oscillatory network patterns in the hippocampus. Whether this phenotype is caused by an alteration in hippocampal interneurons is not known because most studies employed genetic manipulations affecting several brain regions. Here we performed viral injections in genetically modified mice to ablate the GluA4 subunit of the AMPA receptor in the hippocampus (GluA4HC−/− mice), thereby selectively reducing AMPA receptor-mediated currents onto a subgroup of hippocampal interneurons expressing GluA4. This regionally selective manipulation led to a strong spatial working memory deficit while leaving reference memory unaffected. Ripples (125–250 Hz) in the CA1 region of GluA4HC−/− mice had larger amplitude, slower frequency and reduced rate of occurrence. These changes were associated with an increased firing rate of pyramidal cells during ripples. The spatial selectivity of hippocampal pyramidal cells was comparable to that of controls in many respects when assessed during open field exploration and zigzag maze running. However, GluA4 ablation caused altered modulation of firing rate by theta oscillations in both interneurons and pyramidal cells. Moreover, the correlation between the theta firing phase of pyramidal cells and position was weaker in GluA4HC−/− mice. These results establish the involvement of AMPA receptor-mediated currents onto hippocampal interneurons for ripples and theta oscillations, and highlight potential cellular and network alterations that could account for the altered working memory performance

Predictors of Ips confusus Outbreaks During a Record Drought in Southwestern USA: Implications for Monitoring and Management

In many ecosystems the effects of disturbance can be cryptic and disturbance may vary in subtle spatiotemporal ways. For instance, we know that bark beetle outbreaks are more frequent in temperate forests during droughts; however, we have little idea about why they occur in some locations and not others. Understanding biotic and abiotic factors promoting bark beetle outbreaks can be critical to predicting and responding to pest outbreaks. Here we address the environmental factors which are associated with Ips confusus outbreaks during the 2002 widespread drought within the distribution range of pinyon pine woodlands in Arizona. We used univariate statistics to test if whether tree characteristics, other herbivores, stand properties, soil type, wind, and topography were associated with I. confusus outbreak, and logistic regression to create a predictive model for the outbreaks. We found that I. confusus attacks occur in low elevation stands on steeper slopes, where favorable winds for I. confusus dispersion occur. I. confusus select larger trees, in high density stands with understory shrubs that exhibit phenotypic traits characteristic of resistance to stem-boring moths. The model was highly accurate, and explained 95% of the variability in occurrence (98% of the absences and 95% of the presences). Accurate prediction of the impacts of disturbance allow us to anticipate, minimize or mitigate for and eventually counteract its effects, especially those affecting diversity and ecosystem function. Identification of outbreak risk areas can guide regional and national management towards the reduction of infestation risk and enhancing conservation of pinyon-juniper woodlands

Bone mineral density in vocational and professional ballet dancers

Summary: According to existing literature, bone health in ballet dancers is controversial. We have verified that, compared to controls, young female and male vocational ballet dancers have lower bone mineral density (BMD) at both impact and non-impact sites, whereas female professional ballet dancers have lower BMD only at non-impact sites. Introduction: The aims of this study were to (a) assess bone mineral density (BMD) in vocational (VBD) and professional (PBD) ballet dancers and (b) investigate its association with body mass (BM), fat mass (FM), lean mass (LM), maturation and menarche. Methods: The total of 152 VBD (13 ± 2.3 years; 112 girls, 40 boys) and 96 controls (14 ± 2.1 years; 56 girls, 40 boys) and 184 PBD (28 ± 8.5 years; 129 females, 55 males) and 160 controls (27 ± 9.5 years; 110 female, 50 males) were assessed at the lumbar spine (LS), femoral neck (FN), forearm and total body by dual-energy X-ray absorptiometry. Maturation and menarche were assessed via questionnaires. Results: VBD revealed lower unadjusted BMD at all anatomical sites compared to controls (p < 0.001); following adjustments for Tanner stage and gynaecological age, female VBD showed similar BMD values at impact sites. However, no factors were found to explain the lower adjusted BMD values in VBD (female and male) at the forearm (non-impact site), nor for the lower adjusted BMD values in male VBD at the FN. Compared to controls, female PBD showed higher unadjusted and adjusted BMD for potential associated factors at the FN (impact site) (p < 0.001) and lower adjusted at the forearm (p < 0.001). Male PBD did not reveal lower BMD than controls at any site. Conclusions: both females and males VBD have lower BMD at impact and non-impact sites compared to control, whereas this is only the case at non-impact site in female PBD. Maturation seems to explain the lower BMD at impact sites in female VBD

Identification of pediatric septic shock subclasses based on genome-wide expression profiling

<p>Abstract</p> <p>Background</p> <p>Septic shock is a heterogeneous syndrome within which probably exist several biological subclasses. Discovery and identification of septic shock subclasses could provide the foundation for the design of more specifically targeted therapies. Herein we tested the hypothesis that pediatric septic shock subclasses can be discovered through genome-wide expression profiling.</p> <p>Methods</p> <p>Genome-wide expression profiling was conducted using whole blood-derived RNA from 98 children with septic shock, followed by a series of bioinformatic approaches targeted at subclass discovery and characterization.</p> <p>Results</p> <p>Three putative subclasses (subclasses A, B, and C) were initially identified based on an empiric, discovery-oriented expression filter and unsupervised hierarchical clustering. Statistical comparison of the three putative subclasses (analysis of variance, Bonferonni correction, <it>P </it>< 0.05) identified 6,934 differentially regulated genes. K-means clustering of these 6,934 genes generated 10 coordinately regulated gene clusters corresponding to multiple signaling and metabolic pathways, all of which were differentially regulated across the three subclasses. Leave one out cross-validation procedures indentified 100 genes having the strongest predictive values for subclass identification. Forty-four of these 100 genes corresponded to signaling pathways relevant to the adaptive immune system and glucocorticoid receptor signaling, the majority of which were repressed in subclass A patients. Subclass A patients were also characterized by repression of genes corresponding to zinc-related biology. Phenotypic analyses revealed that subclass A patients were younger, had a higher illness severity, and a higher mortality rate than patients in subclasses B and C.</p> <p>Conclusion</p> <p>Genome-wide expression profiling can identify pediatric septic shock subclasses having clinically relevant phenotypes.</p