Exploring environments by hand or foot: Time-based heuristics for encoding distance in movement space.

In Experiment 1, blindfolded observers judged (a) the distance of pathways felt by hand and (b) the straight-line distance between pathway endpoints inferred from such exploration. In Experiment 2, blindfolded observers made corresponding estimates after traversing similar pathways on foot. Pathways were explored under three different speeds. Under both manipulatory and ambulatory exploration, there was substantial length distortion of inferred distance; the straight-line distance was increasingly overestimated with increases in the length of the explored pathway. With manipulatory exploration, slower movements increased length distortion, but duration effects proved secondary to effects of spatial extent. For ambulatory exploration, no duration effects were obtained. Observers used time-independent heuristics, that is, a footstep metric for estimating the pathway actually travelled and a spatial imaging strategy for estimating the inferred line between pathway endpoints. The studies establish length distortion as a general phenomenon in movement space and identify its major causes as spatial rather than temporal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Particle size and aggregation effects on magnetite reactivity toward carbon tetrachloride

Nanoparticulate magnetite is found in many natural and engineered environments. This study characterized the reactivity of this material toward carbon tetrachloride (CCl4). Particle diameter plays an important role, with nominal (9 nm) magnetite suspensions exhibiting greater reactivity on both mass (k(m)) and surface area normalized (k(SA)) bases than (80 nm) magnetite suspensions. For the (9 nm) suspension, the aggregation state of the particles affects the measured km values. At 0.001 M ionic strength and pH 7, k(m) (=0.052-0.139 L g(-1) h(-1)) was as much as seven times larger than at 1 M (k(m) = 0.025-0.030 L g(-1) h(-1)). This decrease in reactivity with an increase in ionic strength is related to the measured diameter of the aggregates present in solution, thus implicating aggregate size as an important variable. This work is the first to indicate that both particle size and aggregation state must be considered when evaluating the reactivity of nanoparticle suspensions with groundwater contaminants.     

Experimental demonstration of a single-molecule electric motor

For molecules to be used as components in molecular machines, methods that couple individual molecules to external energy sources and that selectively excite motion in a given direction are required. Significant progress has been made in the construction of molecular motors powered by light and by chemical reactions, but electrically driven motors have not yet been built, despite several theoretical proposals for such motors. Here we report that a butyl methyl sulphide molecule adsorbed on a copper surface can be operated as a single-molecule electric motor. Electrons from a scanning tunnelling microscope are used to drive the directional motion of the molecule in a two-terminal setup. Moreover, the temperature and electron flux can be adjusted to allow each rotational event to be monitored at the molecular scale in real time. The direction and rate of the rotation are related to the chiralities of both the molecule and the tip of the microscope (which serves as the electrode), illustrating the importance of the symmetry of the metal contacts in atomic-scale electrical devices.     

Emotional reactivity to daily events in major and minor depression.

Although emotional dysfunction is an important aspect of major depressive disorder (MDD), it has rarely been studied in daily life. Peeters, Nicolson, Berkhof, Delespaul, and deVries (2003) observed a surprising mood-brightening effect when individuals with MDD reported greater reactivity to positive events. To better understand this phenomenon, we conducted a multimethod assessment of emotional reactivity to daily life events, obtaining detailed reports of appraisals and event characteristics using the experience-sampling method and the Day Reconstruction Method (Kahneman, Krueger, Schkade, Schwarz, & Stone, 2004) in 35 individuals currently experiencing a major depressive episode, 26 in a minor depressive (mD) episode, and 38 never-depressed healthy controls. Relative to healthy controls, both mood-disordered groups reported greater daily negative affect and lower positive affect and reported events as less pleasant, more unpleasant, and more stressful. Importantly, MDD and mD individuals reported greater reductions in negative affect following positive events, an effect that converged across assessment methods and was not explained by differences in prevailing affect, event appraisals, or medications. Implications of this curious mood-brightening effect are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Monitoring Computer Numerical Control Machining Progress Based on Information Fusion

To cope with the market demand dynamically,enterprise needs to obtain the production status of work in process real-timely,but the information of machining progress has feature of uncertainty and can not reflect the status of production field effectively.In this work,to overcome the ineffectiveness of computer numerical control(CNC) machining progress information extraction and its application restriction in practice because of heterogeneous system of CNC machine,based on information fusion by analyzing multi-sources information,estimating CNC machining status and predicting the machining progress through tracking tool coordinates,a CNC machining progress monitoring method is presented.The multi-sources heterogeneous information includes machining path,real-time spindle power information,manual input data and tool position.On the method of obtaining this multi-sources heterogeneous information,the method which helps explore numerical control(NC) program,monitor spindle power of CNC,collect human-computer interaction(HCI) information,obtain real-time tool coordinates and express the knowledge concerned in this field is analyzed;The decision rule of CNC machining status in the way of fusing multi-sources information in manufacturing process is summarized,as well as the machining progress tracking method in accordance with real-time tool coordinates and machining path is presented.Finally,the method discussed is proved feasible by the verification of machining progress tracking through simulation experiment.The proposed research realizes the effective integration of CNC machining progress information,and enables enterprises an efficient way to share CNC information and configure CNC resources optimally.     

I-beam Crack Identification Based on Study of Local Flexibility due to Crack

Local flexibility of crack plays an important role in crack identification of structures.Analytical methods on local flexibility in a cracked beam with simple geometric crossing sections,such as rectangle,circle,have been made,but there are some difficulties in calculating local flexibility in a cracked beam with complex crossing section,such as pipe and I-beam.In this paper,an analytical method to calculate the local flexibility and rotational spring stiffness due to crack in I-beam is proposed.The local flexibility with respect to various crack depths can be calculated by dividing a cracked I-beam into a series of thin rectangles.The forward and inverse problems in crack detection of I-beam are studied.The forward problem comprises the construction of crack model exclusively for crack section and the construction of a numerically I-beam model to gain crack detection database.The inverse problem consists of the measurement of modal parameters and the detection of crack parameters.Two experiments including measurement of rotational spring stiffness and prediction of cracks in I-beam are conducted.Experimental results based on the current methods indicate that relative error of crack location is less than 3%,while the error of crack depth identification is less than 6%.Crack identification of I-beam is expected to contribute to the development of automated crack detection techniques for railway lines and building skeletons.     

The short-term effects of a fire safety education program for the elderly

The high risk of fire dieath and injury among elderly people is well documented. To be effective, fire safety education must reach older adults in the settings in which they reside: nursing homes and other long-term care institutions, board and care homes, and independent living facilities including the person's own home. Training must also be targeted at the people who are responsible for fire safety. In the case of the nursing home or board and care home, the responsible people are the staff and owners. In the case of the majority of older adults who live independently in their homes, it is either the individual or family members. These programs must also be comprehensive.A fire safety education curriculum was developed by a group of experts in a variety of related fields including fire safety, gerontology, health care industry, developmental disabilities, research, and instructional design. Older adults were included in each planning session. Based on that curriculum, workshops and workshop materials were developed for each of the three target populations: staff of health care facilities, staff and owners of board and care homes, and elderly people living independently in their homes. Materials included both print and audiovisuals. A pilot test of each workshop was conducted to test the short-term effects of the programs.Results indicated significant gains in knowledge for all groups and a significant improvement in positive attitudes toward fire safety for most participants. Measures of effects of the programs on intentions to change fire safety practices indicated a potential for change. Results also showed that the measured traits, knowledge of fire safety and attitudes toward fire safety, were relatively stable.     

Teeth as biomonitors of selenium concentrations in tissues of beluga whales (Delphinapterus leucas)

Selenium (Se) is an essential element which has been shown to play an important role in protecting marine mammals against the toxic effects of mercury (Hg) and other metals. It has been suggested that metal concentration in marine mammal teeth can potentially be used as bioindicators for body burden. The objective of this study was to investigate the relationship between Se concentrations in beluga (Delphinapterus leucas) teeth and those previously measured in soft tissues (liver, kidney, muscle and muktuk). Tooth Hg concentrations are also measured, and the relationships between Se and Hg in teeth and soft tissues are examined. Se in the teeth of beluga was measured using hydride generation atomic fluorescence spectrometry (HG-AFS) and Hg in beluga teeth was measured by cold-vapour atomic absorption. Tooth Se concentrations ranged from 108 ng/g to 245 ng/g dry weight, and tooth Hg concentrations ranged from 10 to 189 ng/g dry weight. In the soft tissues, Se concentrations were highest in the liver, followed by kidney, muktuk, and muscle. There were significant correlations between tooth Se concentrations and animal age, tooth Se and liver and muscle Se, and between liver Se and animal age. The molar ratio of Hg:Se in the liver was found to be 0.70. This study is the first to measure Se in the teeth of a marine mammal species, and HG-AFS is found to be an effective technique for determining Se in beluga teeth. Tooth Se can be used as predictor for liver and muscle Se, although these relationships may be strongly influenced by the association of Se with Hg in marine mammal tissues. This study contributes to an increased understanding of the storage and metabolism of Se in marine mammals.     

Vinyl bromide as a surrogate for determining vinyl chloride reductive dechlorination potential

Site evaluation for bioremediation of chlorinated ethenes may need treatability studies to assess the reductive dechlorination potential of vinyl chloride (VC). Dehalogenation of vinyl bromide (VB) was investigated as a surrogate measurement for the dechlorination potential of VC. VB dehalogenation rates and kinetics were studied and compared with those of VC by a methanogenic reductive dechlorinating enrichment culture that was dominated by Dehalococcoides species and by microcosms from two chloroethene-contaminated sites. The enrichment culture dehalogenated VB to ethene at higher rates than VC at similar concentrations. VB was dehalogenated with a higher enzyme affinity than was VC, as indicated by their half-velocity constants, 240 +/- 150 and 21 +/- 8 microM, for VC and VB, respectively. Cross-inhibition study exhibited some evidence for competitive inhibition between VC and VB, suggesting that their degradation might be catalyzed by the same enzyme in the culture. Laboratory microcosm studies using subsurface soil and groundwater from two contaminated sites demonstrated that the production of the reductive dehalogenation product (ethene) could be detected faster with VB as a substrate than with VC. As a result, a substantially shorter (up to 5-10 times) incubation time would be required to detect the same level of reductive dehalogenation activity using VB as a surrogate for VC in treatability assessments.     

Identification of functionally relevant populations in enhanced biological phosphorus removal processes based on intracellular polymers profiles and insights into the metabolic diversity and heterogeneity

This study proposed and demonstrated the application of a new Raman microscopy-based method for metabolic state-based identification and quantification of functionally relevant populations, namely polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs), in enhanced biological phosphorus removal (EBPR) system via simultaneous detection of multiple intracellular polymers including polyphosphate (polyP), glycogen, and polyhydroxybutyrate (PHB). The unique Raman spectrum of different combinations of intracellular polymers within a cell at a given stage of the EBPR cycle allowed for its identification as PAO, GAO, or neither. The abundance of total PAOs and GAOs determined by Raman method were consistent with those obtained with polyP staining and fluorescence in situ hybridization (FISH). Different combinations and quantities of intracellular polymer inclusions observed in single cells revealed the distribution of different sub-PAOs groups among the total PAO populations, which exhibit phenotypic and metabolic heterogeneity and diversity. These results also provided evidence for the hypothesis that different PAOs may employ different extents of combination of glycolysis and TCA cycle pathways for anaerobic reducing power and energy generation and it is possible that some PAOs may rely on TCA cycle solely without glycolysis. Sum of cellular level quantification of the internal polymers associated with different population groups showed differentiated and distributed trends of glycogen and PHB level between PAOs and GAOs, which could not be elucidated before with conventional bulk measurements of EBPR mixed cultures.