Intraindividual variability is related to cognitive change in older adults: Evidence for within-person coupling.

In this study, the authors addressed the longitudinal nature of intraindividual variability over 3 years. A sample of 304 community-dwelling older adults, initially between the ages of 64 and 92 years, completed 4 waves of annual testing on a battery of accuracy- and latency-based tests covering a wide range of cognitive complexity. Increases in response-time inconsistency on moderately and highly complex tasks were associated with increasing age, but there were significant individual differences in change across the entire sample. The time-varying covariation between cognition and inconsistency was significant across the 1-year intervals and remained stable across both time and age. On occasions when intraindividual variability was high, participants' cognitive performance was correspondingly low. The strength of the coupling relationship was greater for more fluid cognitive domains such as memory, reasoning, and processing speed than for more crystallized domains such as verbal ability. Variability based on moderately and highly complex tasks provided the strongest prediction. These results suggest that intraindividual variability is highly sensitive to even subtle changes in cognitive ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Variability reduction through optimal combination of wind/wave resources – An Irish case study

This study presents a methodology to assess the possible benefits of the combination of wind energy with the still unexploited, but quite significant in Ireland, wave energy. An analysis of the raw wind and wave resource at certain locations around the coasts of Ireland shows how they are very low correlated on the South and West Coast, where the waves are dominated by the presence of high energy swells generated by remote westerly wind systems. As a consequence, the integration of wind and waves in combined farms, at these locations, allows the achievement of a more reliable, less variable and more predictable electrical power production. The resulting benefits are particularly clear in the case of a relatively small and quite isolated electrical system such as the Irish one. Here, in fact, high levels of wind penetration strongly increase the requirement of surplus capacity and cause a much lower efficiency for conventional thermal plants.     

A psychophysiological approach to the assessment of work underload

The findings of a laboratory investigation of the relationship between the subjective and physiological components of work underload are reported. The subjective component is described in terms of the subjective work underload checklist, mental effort, and cognitive arousal. The physiological component is defined in terms of heart rate and heart rate variability. Evidence for an increase in work underload with a decrease in heart rate is provided. The relevance of this research to the aerospace environment is discussed and the need to investigate the behavioural component of work underload emphasized.     

沥青路面施工压实度变异性分析及控制

路面压实度受到不同施工路段工艺水平、施工方法、管理水平的影响而表现出变异性。压实度的变异性往往会改变路面设计结构与实际结构，进而引起路面早期破损。因此，应加强对沥青路面施工压实度变异性的分析与控制。     

Impacts of small scale rainfall variability in urban areas: a case study with 1D and 1D/2D hydrological models in a multifractal framework

In this paper the sensitivity to small scale unmeasured rainfall variability (i.e. at scales smaller than 1 km by 1 km by 5 min in time, which are usually available with C-band radars) of a 1D/2D model with a 10 m resolution and a semi-distributed 1D model of the same 1.47 km² urban area is analyzed. The 1D/2D model is the open source numerical platform Multi-Hydro, which couples (open source) distributed models of involved hydrological/hydraulic processes. The methodology implemented to evaluate the uncertainties consists of generating an ensemble of realistic rainfall fields downscaled to a resolution of 12.3 m in space and 18.75 s in time with the help of a stochastic universal multifractal model. The corresponding ensemble of hydrographs is then simulated. It appears that the uncertainty is significant and that Multi-Hydro unveils much more uncertainty than the simpler 1D model. This points out a need to develop high resolution distributed modelling in urban areas.     

A proteomic analysis of green and white sturgeon larvae exposed to heat stress and selenium

Temperature and selenium are two environmental parameters that potentially affect reproduction and stock recruitment of sturgeon in the San Francisco Bay/Delta Estuary. To identify proteins whose expression is modified by these environmental stressors, we performed a proteomic analysis on larval green and white sturgeons exposed to 18 or 26 °C and micro-injected with Seleno-L-Methionine to reach 8 µg g⁻¹ selenium body burden, with L-Methionine as a control. Selenium and high temperature induced mortalities and abnormal morphologies in both species, with a higher mortality in green sturgeon. Larval proteins were separated by two-dimensional gel electrophoresis and differential abundances were detected following spot quantitation and hierarchical cluster analysis. In green sturgeon, 34 of 551 protein spots detected on gels showed a variation in abundance whereas in white sturgeon only 9 of 580 protein spots were differentially expressed (P < 0.01). Gel replicates were first grouped according to heat treatment. Fifteen of these spots were identified using MALDI TOF/TOF mass spectrometry. Proteins involved in protein folding, protein synthesis, protein degradation, ATP supply and structural proteins changed in abundance in response to heat and/or selenium. 40S ribosomal protein SA, FK506-binding protein 10, 65 kDa regulatory subunit A of protein phosphatase 2, protein disulfide isomerase, stress-induced-phosphoprotein 1, suppression of tumorigenicity 13 and collagen type II alpha 1, were differentially expressed in high temperature treatment only. Serine/arginine repetitive matrix protein 1, creatine kinase, serine peptidase inhibitor Kazal type 5 and HSP90 were sensitive to combined temperature and selenium exposure. Valosin-containing protein, a protein involved in aggresome formation and in protein quality control decreased more than 50% in response to selenium treatment. Potential use of such proteins as biomarkers of environmental stressors in larval sturgeons could indicate early warning signals preceding population decline.     

Strain variability of the behavior of foodborne bacterial pathogens: A review

Differences in phenotypic responses among strains of the same microbial species constitute an important source of variability in microbiological studies, and as such they need to be assessed, characterized and taken into account. This review provides a compilation of available research data on the strain variability of four basic behavioral aspects of foodborne bacterial pathogens including: (i) virulence; (ii) growth; (iii) inactivation; and (iv) biofilm formation. A particular emphasis is placed on the foodborne pathogens Listeria monocytogenes and Salmonella enterica. The implications of strain variability for food safety challenge studies and microbial risk assessment are discussed also. The information provided indicates that the variability among strains of foodborne bacterial pathogens with respect to their behavior can be significant and should not be overlooked. However, in order for the mechanisms underlying the observed strain variability to be elucidated and understood, phenotypic variability data, such as those reviewed here, should be evaluated in conjunction with corresponding findings of studies assessing the molecular/physiological basis of this variability.     

A dynamical framework to understand performance trade-offs and interference in dual tasks.

This study demonstrated that the dynamic pattern approach may reconcile resource and outcome conflict theories to explain performance in dual tasks. Participants performed a bimanual coordination task and a reaction time task with different conditions of attentional priority. Results showed a trade-off between pattern variability and reaction time when priority was given to the coordination task. Such a trade-off was indicative of resource allocation. An analysis of perturbation in the bimanual coordination revealed interference, a reputed sign of outcome conflict. Moreover, interference diminished substantially when priority was given to the bimanual task. The coexistence of performance trade-off and outcome conflict suggests that these two phenomena are not mutually exclusive. Rather, both may follow from modifying the coupling between the limbs through attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

THE RELATIONSHIP BETWEEN DIAL SIZE,READING DISTANCE AND READING ACCURACY

The experiment reported suggests that the accuracy of reading a graduated scale is related to the angle subtended at the eye by the called space. There is a critical point representing about 98 per cent accuracy (for all intervals interpolated into five or less parts) below which there is a rapid fall off in accuracy and above which little improvement can be expected. Each combination of scale interval and called interval has a different critical point and from these it is possible to calculate the optimum reading distance for any dial size and vice versa. It is possible also to decide which of several alternative graduation systems is likely to be the best.

It was found that ‘ practised subjects ’—who had made more than 2000 readings on a particular graduation system—were able to read a dial at double the distance of an ‘ unpractised subject ’ both having 6/6 binocular eyesight. For ‘ practised subjects ’ with 6/12 binocular eyesight the reading distances were reduced by one fifth.