772 research outputs found
Challenging the role of implicit processes in probabilistic category learning
Considerable interest in the hypothesis that different cognitive tasks recruit qualitatively distinct processing systems has led to the proposal of separate explicit (declarative) and implicit (procedural) systems. A popular probabilistic category learning task known as the weather prediction task is said to be ideally suited to examine this distinction because its two versions, '' observation '' and '' feedback,'' are claimed to recruit the declarative and procedural systems, respectively. In two experiments, we found results that were inconsistent with this interpretation. In Experiment 1, a concurrent memory task had a detrimental effect on the implicit (feedback) version of the task. In Experiment 2, participants displayed comparable and accurate insight into the task and their judgment processes in the feedback and observation versions. These findings have important implications for the study of probabilistic category learning in both normal and patient populations
Prime numbers: anchoring and its implications for theories of behavior priming
Subtle primes can influence behavior, often in ways that seem irrational. Anchoring provides a compelling illustration of this: judgments can be influenced by anchors even when the anchors are known to be irrelevant and uninformative. In this article, we selectively examine the anchoring literature in order to evaluate a theoretical framework which has been employed to interpret many social and other priming effects. In this framework, primes are assumed to have broad effects, influencing a wide range of possible downstream behaviors, and these influences are largely automatic. The anchoring literature supports neither of these hypotheses. Anchors have narrow effects on behavior with little transfer across judgments, these effects can be controlled, and deliberate engagement with the anchor is a prerequisite for obtaining influences on later judgments. We question whether priming studies reveal evidence for the sort of automatic and consequential mental processes that are commonly proposed.
Read More: http://guilfordjournals.com/doi/abs/10.1521/soco.2014.32.supp.8
Creating a Healthy Rural Ecosystem for Community Vitality: Developing Rural Community Business Research
The objective of this project is to create a model of and mechanism for statewide, systematic data collection to support workforce development pathways for P-20 students in rural Maine to ensure the long-term vitality and success of these communities. Businesses, as sites of financial and social capital development, can be more thoughtfully calibrated to local workforce needs in these communities. However, data is not currently made available to businesses and community leaders that would allow them to make thoughtful decisions about how to use community resources and time in order to create these partnerships. Businesses and economic growth in rural communities are intertwined–the development of the community is intrinsically linked to the success of its small businesses, and without qualified and educated workers businesses cannot thrive (Bird, Sapp, & Lee, 2001; Schafft, 2016; Tigges & Green, 1994). Despite challenges in providing a quality education and business opportunities, these communities still have the potential to be successful in the long-term. Through a series of semi-structured interviews with stakeholders in two rural Maine communities the researchers will utilize their preliminary research to gain a deeper understanding of the towns and collect data through the interviews in order to aid the economic development of businesses in the communities
Public health implications of metals concentrations from prescribed burns: A study adjacent to the Perth metropolitan area.
Ash is not a homogenous product. It is the solid residue of combustion and contains a complex mixture of chemical products. The ash residue resulting from fires varies and is dependent on its source, and burn characteristics such as the temperature of the fire. Ash comprises particles of carbon, soot and trace elements. Ash presents public health risk to people and communities, through direct and indirect ingestion and inhalation. The health effects of ash exposure are not limited to symptoms affecting the eyes, throat and lungs. They can contribute to chronic disease and increase the risk of cancer. The purpose of this study was to evaluate the public health implications of controlled burns in the Darling Escarpment, adjacent to Perth’s metropolitan area in Western Australia. Concentrations of metals in unburnt vegetative litter and ash (post burn), stratified by size fraction, were determined to assess the potential mobilisation of metals caused by prescribed burns and the potential public health implications associated with burns. These data can also be used in predictive modelling to ascertain the amount of metals likely to be released per hectare when authorities plan future burns in the area.  Ash samples were collected immediately following the fire to capture fine material before it was blown away. The ash samples were separated into size fractions to investigate whether there are differences within each sub sample. Australia’s National Environmental Protection Measures were used to establish whether the metal concentrations were above designated thresholds for health and environmental investigation, these being the recognised levels above which metals are deemed to pose a risk to public (or environmental) health.  Vegetation and ash samples were collected from three sites immediately after the prescribed burn. Samples were analysed for thirteen (13) metals with nine (9) showing statistically significant increases in concentrations in vegetation as compared to ash. The percentages of metals are higher in ash than in vegetative ground litter. The metals identified are Manganese - Vegetation (158.3 ± 89.3 mg/kg), Ash (442.2 ± 462.6 mg/kg); Barium - Vegetation (19.4 ± 25.3 mg/kg); Ash (41.8 ± 62.7 mg/kg); Zinc - Vegetation (15.3 ± 9.7 mg/kg), Ash (25.6 ± 29.7 mg/kg); Vanadium - Vegetation (31.0 mg/kg ± 76.3 mg/kg), Ash (32.2 mg/kg ± 51.0 mg/kg); Copper - Vegetation (4.2 ± 1.5 mg/kg), Ash (10.9 ± 9.8 mg/kg); Chromium (Total) - Vegetation (8.3 ± 15.6 mg/kg), Ash (9.6 ± 12.4 mg/kg); Lead - Vegetation (6.1 ± 8.3 mg/kg), Ash (12.2 ± 8.5 mg/kg); Nickel - Vegetation (2.2 ± 2.2 mg/kg), Ash (4.7 ± 4.4mg/kg) and Cadmium - Vegetation (0.6 ± 0.9 mg/kg), Ash (0.6 ± 0.9 mg/kg). The ash samples were sieved through three aperture’s (2-4 mm, 1-2 mm, <1 mm) to stratify the samples by size fraction and concentrations in all but three of the metals increased as the ash size decreased.It was demonstrated that the level of metal present within the ash samples did not exceed health investigation levels and, with the exception of Manganese, and did not exceed environmental investigations levels. Metals were unlikely to pose a risk if left insitu. However, modelling estimated the volume of metal released and it was determined that metals can pose a subsequent risk if mobilised by wind or water. The likelihood of such mobilisation is high and this finding therefore has public health implications for surrounding communities that are subjected to increases in their exposure to metals, associated with bushfires.The findings from this study contribute to the management of prescribed burns by providing a better understanding of the composition of ash and the effects of potential distribution via aerial deposition or runoff. Data from this study can be used to do predictive modelling of heavy metal mobilisation that may result from burns of similar vegetation environments. This becomes particularly significant where burns are conducted in water catchment areasÂ
Chemical transport across the ITCZ in the central Pacific during an El Niño-Southern Oscillation cold phase event in March-April 1999
We examine interhemispheric transport processes that occurred over the central Pacific during the PEM-Tropics B mission (PTB) in March-April 1999 by correlating the observed distribution of chemical tracers with the prevailing and anomalous windfields. The Intertropical Convergence Zone (ITCZ) had a double structure during PTB, and interhemispheric mixing occurred in the equatorial region between ITCZ branches. The anomalously strong tropical easterly surface wind had a large northerly component across the equator in the central Pacific, causing transport of aged, polluted air into the Southern Hemisphere (SH) at altitudes below 4 km. Elevated concentrations of chemical tracers from the Northern Hemisphere (NH) measured south of the equator in the central Pacific during PTB may represent an upper limit because the coincidence of seasonal and cold phase ENSO conditions are optimum for this transport. Stronger and more consistent surface convergence between the northeasterly and southeasterly trade winds in the Southern Hemisphere (SH) resulted in more total convective activity in the SH branch of the ITCZ, at about 6° S. The middle troposphere between 4-7 km was a complex shear zone between prevailing northeasterly winds at low altitudes and southwesterly winds at higher altitudes. Persistent anomalous streamline patterns and the chemical tracer distribution show that during PTB most transport in the central Pacific was from SH to NH across the equator in the upper troposphere. Seasonal differences in source strength caused larger interhemispheric gradients of chemical tracers during PTB than during the complementary PEM-Tropics A mission in September-October 1996. Copyright 2001 by the American Geophysical Union
A meteorological overview of the Pacific Exploratory Mission (PEM) Tropics period
NASA's Pacific Exploratory Mission-Tropics (PEM-T) experiment investigated the atmospheric chemistry of a large portion of the tropical and subtropical Pacific Basin during August to October 1996. This paper summarizes meteorological conditions over the PEM-T domain. Mean flow patterns during PEM-T are described. Important circulation systems near the surface include subtropical anticyclones, the South Pacific Convergence Zone (SPCZ), the Intertropical Convergence Zone (ITCZ), and middle latitude transient cyclones. The SPCZ and ITCZ are areas of widespread ascent and deep convection; however, there is relatively little lightning in these oceanic regions. A large area of subsidence is associated with the subtropical anticyclone centered near Easter Island. PEM-T occurred during a period of near normal sea surface temperatures. When compared to an 11 year climatology (1986-1996), relatively minor circulation anomalies are observed during PEM-T. Some of these circulation anomalies are consistent with much stronger anomalies observed during previous La Nina events. In general, however, the 1996 PEM-T period appears to be climatologically representative. Meteorological conditions for specific flights from each major operations area are summarized. The vertical distribution of ozone along selected DC-8 flights is described using the DIAL remote sensing system. These ozone distributions are related to thermodynamic soundings obtained during aircraft maneuvers and to backward trajectories that arrived at locations along the flight tracks. Most locations in the deep tropics are found to have relatively small values of tropospheric ozone. Backward trajectories calculated from global gridded analyses show that much of this air originates from the east and has not passed over land within 10 days. The deep convection associated with the ITCZ and SPCZ also influences the atmospheric chemistry of these regions. Flights over portions of the subtropics and middle latitudes document layers of greatly enhanced tropospheric ozone, sometimes exceeding 80 ppbv. In situ carbon monoxide in these layers often exceeds 90 ppbv. These regions are located near, and especially south of Tahiti, Easter Island, and Fiji. The layers of enhanced ozone usually correspond to layers of dry air, associated with widespread subsiding air. The backward trajectories show that air parcels arriving in these regions originate from the west, passing over Australia and even extending back to southern Africa. These are regions of biomass burning. The in situ chemical measurements support the trajectory-derived origins of these ozone plumes. Thus the enhanced tropospheric ozone over the central Pacific Basin may be due to biomass burning many thousands of kilometers away. Middle-latitude portions of the PEM-T area are influenced by transient cyclones, and the DC-8 traversed tropopause folds during several flights. The flight area just west of Ecuador experiences outflow from South America. Thus the biomass burning that is prevalent over portions of Brazil influences this area. Copyright 1999 by the American Geophysical Union
Chemical characteristics of Pacific tropospheric air in the region of the Intertropical Convergence Zone and South Pacific Convergence Zone
The Pacific Exploratory Mission (PEM)-Tropics provided extensive aircraft data to study the atmospheric chemistry of tropospheric air in Pacific Ocean regions, extending from Hawaii to New Zealand and from Fiji to east of Easter Island. This region, especially the tropics, includes some of the cleanest tropospheric air of the world and, as such, is important for studying atmospheric chemical budgets and cycles. The region also provides a sensitive indicator of the global-scale impact of human activity on the chemistry of the troposphere, and includes such important features as the Pacific "warm pool," the Intertropical Convergence Zone (ITCZ), the South Pacific Convergence Zone (SPCZ), and Walker Cell circulations. PEM-Tropics was conducted from August to October 1996. The ITCZ and SPCZ are major upwelling regions within the South Pacific and, as such, create boundaries to exchange of tropospheric air between regions to the north and south. Chemical data obtained in the near vicinity of the ITCZ and the SPCZ are examined. Data measured within the convergent zones themselves are not considered. The analyses show that air north and south of the convergent zones have different chemical signatures, and the signatures are reflective of the source regions and transport histories of the air. Air north of the ITCZ shows a modest urban/industrialized signature compared to air south of the ITCZ. The chemical signature of air south of the SPCZ is dominated by combustion emissions from biomass burning, while air north of the SPCZ is relatively clean and of similar composition to ITCZ south air. Chemical signature differences of air north and south of the zones are most pronounced at altitudes below 5 km, and, as such, show that the ITCZ and SPCZ are effective low-altitude barriers to the transport of tropospheric air. At altitudes of 8 to 10 km, chemical signatures are less dissimilar, and air backward trajectories (to 10 days) show cross-convergent-zone flow. At altitudes below about 5 km, little cross-zonal flow is observed. Chemical signatures presented include over 30 trace chemical species including ultrafine, fine, and heated-fine (250°C) aerosol. Copyright 1999 by the American Geophysical Union
LIMIT CYCLE DYNAMICS ACROSS ELITE MALE ARTISTIC GYMNASTS
Biological systems described by their attractor dynamics provide a method to understand the fundamental characteristics of skilled movement. Here the limit cycle dynamics of the longswing were investigated across tiers of elite men’s gymnasts. Senior, junior and development elite gymnasts (N=21) performed three trials of eight consecutive longswings on high bar. Limit cycle analysis revealed a more symmetrical angular velocity of the centre of mass about the bar trajectory in phase space, higher recurrence, lower correlation dimension and lower variability for senior gymnasts suggesting a more deterministic, efficient and predictive technique. The addition of non-linear dynamics to traditional biomechanics offers complementary theoretical and coaching knowledge to movement coordination, control and skill
DYNAMICS OF A CYCLIC TASK BEFORE AND AFTER A CHANGE IN TASK CONSTRAINT: HORIZONTAL BAR LONGSWING
Returning to a consistent technique after a change in skill allows gymnasts to improve routine fluidity. This study investigates the limit cycle dynamics of the mass centre (CM) after a variation in task constraint during the horizontal bar longswing (LS). Gymnasts (n=12) from 3 different age categories completed 3 x 8 consecutive LS with LS four and five as accelerated LS. Senior gymnasts presented the most consistent limit cycle trajectory and lowest correlation dimension (CD) post- compared to pre- task constraint. Senior gymnasts displayed significantly lower CD post- constraint compared to both junior (p = .016) and development gymnasts (p\u3c .001). The increased proficiency attributed to senior gymnasts appears to increase the stability features of the LS limit cycle of the CM angular velocity after an imposed task constraint which may indicate readiness to progress to more complex horizontal bar skills
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