A longitudinal study of convergence changes with age

Longitudinal changes in convergence behavior measured by phoria and duction tests were studied in twenty-one subjects between the ages of 35 and 60 years. The far lateral phoria and base-out duction recovery at near did not change significantly. In agreement with othet· studies, the near lateral phoria was found to shift in an exophoric direction, but only by approximately two prism diopters. A composite measure of the convergence-divergence system (convergence index scores) showed a decline, indicating a loss in ability compared to young adult standards. Wide variations were found both between and within subjects among individual test components of the convergence-divergence system

Nitrate derived from Onsite Wastewater Treatment Systems (NOWTS): A Study of Public Perceptions, Politics, and Perpetual Permitting in the Western US

Onsite wastewater treatment systems (OWTS; septic systems, compost toilets, etc.) used to treat wastewater in rural areas have the potential to contaminate groundwater (that is used as a water source) with nitrate. There have been decades of scientific and political conflicts concerning the issue of nitrate from OWTS (NOWTS, pronounced “knots”) in the communities of La Pine, Oregon and Laramie, Wyoming. This dissertation explores the science and policy of NOWTS conflicts to determine how decision makers, experts, consultants, residents, stakeholders, and the author effect, and are affected by, the NOWTS conflicts. This dissertation explores the conflicts in La Pine and Laramie through four chapters. Chapter two is a soil study conducted in La Pine to determine how much nitrate from septic systems reaches the water table. It was found that there was more nitrate in soils at residences with septic systems than other areas, but due to the limitations of the study source of the nitrate was uncertain. The HYDRUS model was used to simulate nitrate transport from septic systems and found that nitrate concentrations are reduced by 24-40% by the time septic water reaches the water table in La Pine. Chapter three analyzes how stakeholders were affected by the history and the geographic setting of conflicts in La Pine and Laramie. Information was collected from surveys in La Pine, interviews in Laramie, and documentation of the conflicts from both locations. Geographically it was found that stakeholders in La Pine and Laramie were split along the urban-rural divide. From the history stakeholders became more knowledgeable of the conflict, stakeholders created opinions of other stakeholders that colored interactions, and stakeholders were fatigued by the conflicts. Chapter four explores the role of government experts, consultants, and academics (GAC experts) in the conflicts in La Pine and Laramie through five controversial studies in La Pine and Laramie. It was found that miscommunications occurred between GAC experts and stakeholders that escalated conflicts. Miscommunications included the role experts were supposed to play in the conflict. GAC expert’s language and mannerism, such as dumping too much information on stakeholder at one time. There were also study limitations and external factors that made is so that experts could not sufficiently address stakeholder questions and concerns. Chapter five studies the role of science created by residents (resident science) in La Pine in Laramie. Some residents have high educational attainments and are professionals in water resources related fields and conducted resident science independently or with the support of non-governmental organizations. Factors that led to the creation of resident science were mistrust between residents and experts, residents noticed data gaps or had unanswered questions, and stakeholders had the resources for resident science. Though resident science was controversial in La Pine and Laramie it was accepted enough that it was part of the conflict dialog and affected policies. The conclusion summarizes the findings from the previous chapters and provides policy recommendations and recommendations for future NOWTS studies. The policy recommendations were to involve more groups and to expand the scope of the conflict to increase the pool of resources and add flexibility to the conflict. Another was to leverage small cooperative projects between multiple groups to build trust and political momentum for larger actions. Science recommendations focus on ways for experts to collaborate with stakeholders to assuage conflict. Both the science and policy issues need to be addressed to move forward on NOWTS conflict

Thermal extrusion of a non-linear viscoelastic solid inside a long cylindrical tube

An analysis is presented for the axial extrusion of an expanding viscoelastic solid inside a long cylindrical tube. Both differential thermal expansion and expansion of gas bubbles in the solid are considered as driving mechanisms. Finite element calculations are used to illustrate the details of the behavior of the system. The response is shown to be initially elastic followed by the development of a boundary layer near the free surface where the pressure gradients are sufficiently large to cause axial viscous flow. Simple boundary layer equations are derived to describe this flow. Results using these equations agree well with the results of the finite element calculations. The theory is applied to the extrusion of uranium-based metallic reactor fuel during overheating transients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47818/1/466_2004_Article_BF00282136.pd

Politiewerking in multiculturele buurten: de beeldvorming bij burgers en agenten over de gemeenschapsgerichte politiezorg

In deze bijdrage wordt een antwoord geformuleerd op de vraag hoe politiemensen omgaan met etnisch-culturele minderheden op basis van data verzameld in het kader van een 34 maand durend beleidsgericht onderzoek naar de toepassing van de gemeenschapsgerichte politiezorg in multiculturele buurten (in opdracht van Federaal Wetenschapsbeleid). Daarbij werden in vijf Belgische politiezones observaties uitgevoerd bij wijk- en interventieagenten die in multiculturele buurten werkzaam zijn. Het onderzoek beoogt inzicht te verwerven in de manier waarop interacties tussen politie en etnisch-culturele minderheden verlopen en de elementen die deze interacties beïnvloeden. Percepties, betekenisverlening en verwachtingen werden in kaart gebracht. Concreet zal de bijdrage ingaan op de beeldvorming over etnische culturele minderheden bij wijk- en interventieagenten met aandacht voor de inhoud ervan, de totstandkoming en de factoren die erop van invloed zijn. Vervolgens wordt de vraag beantwoord in welke mate en op welke manier beelden en attitudes ook het gedrag van de politiemensen op het terrein beïnvloeden met aandacht voor de situationele, contextuele, persoonlijke en organisatorische factoren die daarop van invloed zijn

Recent changes of water discharge and sediment load in the Yellow River basin, China

The Yellow River basin contributes approximately 6% of the sediment load from all river systems globally, and the annual runoff directly supports 12% of the Chinese population. As a result, describing and understanding recent variations of water discharge and sediment load under global change scenarios are of considerable importance. The present study considers the annual hydrologic series of the water discharge and sediment load of the Yellow River basin obtained from 15 gauging stations (10 mainstream, 5 tributaries). The Mann-Kendall test method was adopted to detect both gradual and abrupt change of hydrological series since the 1950s. With the exception of the area draining to the Upper Tangnaihai station, results indicate that both water discharge and sediment load have decreased significantly (p<0.05). The declining trend is greater with distance downstream, and drainage area has a significant positive effect on the rate of decline. It is suggested that the abrupt change of the water discharge from the late 1980s to the early 1990s arose from human extraction, and that the abrupt change in sediment load was linked to disturbance from reservoir construction.Geography, PhysicalGeosciences, MultidisciplinarySCI(E)43ARTICLE4541-5613

The effects of emotional states and traits on time perception

Background: Models of time perception share an element of scalar expectancy theory known as the internal clock, containing specific mechanisms by which the brain is able to experience time passing and function effectively. A debate exists about whether to treat factors that influence these internal clock mechanisms (e.g., emotion, personal- ity, executive functions, and related neurophysiological components) as arousal- or attentional-based factors. Purpose: This study investigated behavioral and neurophysiological responses to an affective time perception Go/ NoGo task, taking into account the behavioral inhibition (BIS) and behavioral activation systems (BASs), which are components of reinforcement sensitivity theory. Methods: After completion of self-report inventories assessing personality traits, electroencephalogram (EEG/ERP) and behavioral recordings of 32 women and 13 men recruited from introductory psychology classes were completed during an affective time perception Go/NoGo task. This task required participants to respond (Go) and inhibit (NoGo) to positive and negative affective visual stimuli of various durations in comparison to a standard duration. Results: Higher BAS scores (especially BAS Drive) were associated with overestimation bias scores for positive stimuli, while BIS scores were not correlated with overestimation bias scores. Furthermore, higher BIS Total scores were associ- ated with higher N2d amplitudes during positive stimulus presentation for 280 ms, while higher BAS Total scores were associated with higher N2d amplitudes during negative stimuli presentation for 910 ms. Discussion: Findings are discussed in terms of arousal-based models of time perception, and suggestions for future research are considered

Reading faces: differential lateral gaze bias in processing canine and human facial expressions in dogs and 4-year-old children

Sensitivity to the emotions of others provides clear biological advantages. However, in the case of heterospecific relationships, such as that existing between dogs and humans, there are additional challenges since some elements of the expression of emotions are species-specific. Given that faces provide important visual cues for communicating emotional state in both humans and dogs, and that processing of emotions is subject to brain lateralisation, we investigated lateral gaze bias in adult dogs when presented with pictures of expressive human and dog faces. Our analysis revealed clear differences in laterality of eye movements in dogs towards conspecific faces according to the emotional valence of the expressions. Differences were also found towards human faces, but to a lesser extent. For comparative purpose, a similar experiment was also run with 4-year-old children and it was observed that they showed differential processing of facial expressions compared to dogs, suggesting a species-dependent engagement of the right or left hemisphere in processing emotions

Enhanced Memory for Scenes Presented at Behaviorally Relevant Points in Time

What determines whether a scene is remembered or forgotten? Our results show how visual scenes are encoded into memory at behaviorally relevant points in time

Mood Modulates Auditory Laterality of Hemodynamic Mismatch Responses during Dichotic Listening

Hemodynamic mismatch responses can be elicited by deviant stimuli in a sequence of standard stimuli even during cognitive demanding tasks. Emotional context is known to modulate lateralized processing. Right-hemispheric negative emotion processing may bias attention to the right and enhance processing of right-ear stimuli. The present study examined the influence of induced mood on lateralized pre-attentive auditory processing of dichotic stimuli using functional magnetic resonance imaging (fMRI). Faces expressing emotions (sad/happy/neutral) were presented in a blocked design while a dichotic oddball sequence with consonant-vowel (CV) syllables in an event-related design was simultaneously administered. Twenty healthy participants were instructed to feel the emotion perceived on the images and to ignore the syllables. Deviant sounds reliably activated bilateral auditory cortices and confirmed attention effects by modulation of visual activity. Sad mood induction activated visual, limbic and right prefrontal areas. A lateralization effect of emotion-attention interaction was reflected in a stronger response to right-ear deviants in the right auditory cortex during sad mood. This imbalance of resources may be a neurophysiological correlate of laterality in sad mood and depression. Conceivably, the compensatory right-hemispheric enhancement of resources elicits increased ipsilateral processing

Cluster analysis of behavioural and event-related potentials during a contingent negative variation paradigm in remitting-relapsing and benign forms of multiple sclerosis

<p>Abstract</p> <p>Background</p> <p>Event-related potentials (ERPs) may be used as a highly sensitive way of detecting subtle degrees of cognitive dysfunction. On the other hand, impairment of cognitive skills is increasingly recognised as a hallmark of patients suffering from multiple sclerosis (MS). We sought to determine the psychophysiological pattern of information processing among MS patients with the relapsing-remitting form of the disease and low physical disability considered as two subtypes: 'typical relapsing-remitting' (RRMS) and 'benign MS' (BMS). Furthermore, we subjected our data to a cluster analysis to determine whether MS patients and healthy controls could be differentiated in terms of their psychophysiological profile.</p> <p>Methods</p> <p>We investigated MS patients with RRMS and BMS subtypes using event-related potentials (ERPs) acquired in the context of a Posner visual-spatial cueing paradigm. Specifically, our study aimed to assess ERP brain activity in response preparation (contingent negative variation -CNV) and stimuli processing in MS patients. Latency and amplitude of different ERP components (P1, eN1, N1, P2, N2, P3 and late negativity -LN) as well as behavioural responses (reaction time -RT; correct responses -CRs; and number of errors) were analyzed and then subjected to cluster analysis.</p> <p>Results</p> <p>Both MS groups showed delayed behavioural responses and enhanced latency for long-latency ERP components (P2, N2, P3) as well as relatively preserved ERP amplitude, but BMS patients obtained more important performance deficits (lower CRs and higher RTs) and abnormalities related to the latency (N1, P3) and amplitude of ERPs (eCNV, eN1, LN). However, RRMS patients also demonstrated abnormally high amplitudes related to the preparation performance period of CNV (cCNV) and post-processing phase (LN). Cluster analyses revealed that RRMS patients appear to make up a relatively homogeneous group with moderate deficits mainly related to ERP latencies, whereas BMS patients appear to make up a rather more heterogeneous group with more severe information processing and attentional deficits.</p> <p>Conclusions</p> <p>Our findings are suggestive of a slowing of information processing for MS patients that may be a consequence of demyelination and axonal degeneration, which also seems to occur in MS patients that show little or no progression in the physical severity of the disease over time.</p