A neural network model of visual object recognition impairment after brain damage

Dysfunction of the visual object recognition system in humans is briefly discussed and a basic connectionist model of visual object recognition is introduced. Experimentation in which two variants of this model are lesioned is undertaken. The results suggest that the well documented phenomenon of superordinate preservation is model independent. Differential category specific recognition deficits are also observed in this model, however these are sensitive to each particular variant

The role of eye movements in the figure perception

The figure-ground distinction is particularly interesting where the same stimulus can give rise to more than the one interpretation of figure. The work presented here examines the role of eye movements in such figure perception. The figure-ground dichotomy is first elaborated and stimuli which can give different figural interpretations are classified as reversible perspective or ambiguous figures. Theories which have been proposed to account for such figure perception are then reviewed and it is argued that a schematic map theory offers a plausible explanation. The parameters which have been studied with regard to these stimuli are then considered and it is argued that the role of eye movements has not been adequately investigated. Stimuli are then proposed to be composed of elements which are differentially weighted towards each figural aspect. Figure perception is largely a result of an observer selectively attending to these elements as determined by the schematic map. Eye movements function to move such attention about the stimulus. A series of afterimage experiments then examines the existence of such elements in a line drawing of Boring's ambiguous figure. The response of figure was found to be governed by the elements to which the subject could attend. Two free-viewing experiments are then reported which demonstrated that in a non- stabilised condition the immediate response of figure was determined by the elements present in the stimulus. No age-related effects of such elements were found when children served as subjects. Eye movement types and recording techniques are then reviewed and an inconspicuous recording method developed. Subjects' eye movements were then recorded as they viewed versions of the ambiguous figure. The results are interpreted as supporting a schematic map explanation. A model is finally developed to account for the role of eye movements in figure perception

An investigation of some sulfide deposits of the rambler area, Newfoundland

The geology of the Rambler area, Newfoundland, is described. The rocks of the area consist mainly of ultramafic and tholeiitic pillow lavas and associated pyroclastic rocks. Clastic sedimentary rocks, acidic lavas and pyroclastics, and thin units of an acidic ‘chert-like’ rock are interbanded with the lavas and pyroclastics. Metadolerite dikes intrude all other rocks in the area. The field and petrographic relationships suggest that the area has undergone at least three deformational and two meta- morphic events. The first deformational event was mainly constrictive and produced rock fabrics which locally approach those of L tectonites; mineral and particle lineations are abundant. This deformational event was accompanied by meta- morphism to the quartz-albite-epidote-almandine subfacies of the greenschist fades. Structures produced by the first deformational event were folded by at least two later deformations into earlier tight, northeast plunging, isoclinal folds which were followed by development of open recumbent folds. A second metamorphic event which appears to have post dated the folding, attained conditions of biotite grade green- schist metamorphism. Major and trace element data are presented for the country rocks. The tholeiitic lavas are chemically similar to present day ocean floor basalts and the ultramafics to rocks described from the Komatii formation in the Barberton Mountain Land, South Africa, by R.P. Viljoen and M.J. Viljoen in 1970. The association of ultramafic lavas, ocean floor type lavas basic pyroclastics, ' chert - like' sediments, acidic lavas and low potassium basic intrusives (metadolerites) suggests that the Rambler area represents an ancient ocean floor complex - probably part of an ophiolite complex. The geology and mineralogy of several of the sulfide deposits are described, their textures being explainable in terms of the deformational and metamorphic events affecting the area. The sulfide deposits have been deformed and metamorphosed during the first constrictive deformation and their textures are the result of recrystallization under conditions of the biotite grade greenschist facies of metamorphism. Fluidinclusion filling temperatures on the quartz gangue in remobilised sulfide veins gave temperatures (uncorrected for pressure) of crystallization of 145~330 C. The geochemistry of the East Mine ore body is described and the genesis of the sulfide deposit s is discussed in the light of the geochemical and petrological data. Although it is difficult to establish clearly the mode of formation of the highly metamorphosed and deformed sulfide deposits the bulk of available in formation favours a 'syngenetic’ rather than an ' epigenetic replacement’ mode of formation

CO2-ECBM: A Review of its Status and Global Potential

AbstractIn 1998, the IEA Greenhouse Gas R&D Programme (IEAGHG) assessed the global potential for CO2 enhanced coal bed methane (CO2-ECBM) recovery and associated CO2 storage based on data from the one successful pilot project at the time in the San Juan Basin in the USA. After 1998, subsequent CO2 injection projects in coal seams were generally determined not to be successful. Nonetheless, these projects contributed to “lessons learned” that helped advise further research and demonstration (R&D) activities.IEAGHG recently reassessed the status of R&D in CO2-ECBM and CO2 storage. In this assessment, the primary objectives were to: (1) assess the global status of coalbed methane (CBM) production and the potential effects on CO2 storage; (2) review the current status of research into the enhanced gas recovery (EGR) and geological storage of CO2 in coals; and (3) develop an updated assessment of the global potential for EGR and geological storage of CO2 in coal formations.The paper summarizes the results of this work, along with other related activities. It reviews the results from more recent CO2- ECBM and CO2 storage trials in the San Juan Basin in the USA, the results of other small-scale demonstration projects conducted by the U.S. Department of Energy's (DOE's) Regional Carbon Sequestration Partnerships (RCSP) Program, and reviews the status of an ongoing DOE-funded project conducted by CONSOL and Virginia Tech University in the USA, as well as for the Coal-Seq Consortium.The IEAGHG study concluded that the technical recovery potential for methane from the world's coal seams is estimated to be 79 trillion cubic meters (Tcm) globally, 29Tcm associated with conventional CBM recovery, and 50Tcm from the application of CO2- ECBM recovery as a secondary production technique. This could facilitate the potential storage of nearly 488 billion metric tons (or gigatonnes (Gt)) of CO2 in unmineable coal seams

Magnesium - Tellurium by Powder Methods

Today considerable work is being done in the compressed metal powder field which is gradually ob­taining prominence as a valuable branch of metallurgy. The mass of data, however, has led to many different ideas on the results of sintering

Acerca de lo que Dios eligió: libertad de Dios y perfección

Nicholas Rescher ha sostenido con elegancia que el Principio de Perfección le sirve a Leibniz como un principio de contingencia que asegura la libertad de Dios y por tanto la de Sus creaciones. No me propongo criticar el punto de vista de Rescher, puesto que en líneas generales lo considero acertado, sino enriquecerlo con un tratamiento específico extenso, y seguir algunas de las consecuencias de lo así agregado. Una de éstas es el poner en tela de juicio algunas de las interpretaciones generalmente aceptadas, eligió este mundo en particular y la creencia en incluyendo, por ejemplo, la creencia en que Dios que la perfección consiste en la noción simple extensión de composibilidad.Departamento de Filosofí

Abundance estimation from multiple data types for groupliving animals: An example using dhole (Cuon alpinus)

Large carnivores are declining globally and require baseline population estimates for management, however large-scale population estimation is problematic for species without unique natural marks. We used camera trap records of dhole Cuon alpinus, a group-living species, from three national parks in Thailand as a case study in which we develop integrated likelihood models to estimate abundance incorporating two different data sets, count data and detection/non-detection data. We further investigated relative biases of the models using different proportions of data with lower versus higher quality and assessed parameter identifiability. The simulations indicated that the relative bias on average across 24 tested scenarios was 2% with a 95% chance that the simulated data sets obtained the true animal abundances. We found that bias was high (\u3e10%) when sampling 60 sites with only 5 sampling occasions. We tested four additional scenarios with varying proportions of count data. Our model tolerated the use of relatively low proportions of the higher quality count data, but below 10% the results began to show bias (\u3e6%). Data cloning indicated that the parameters were identifiable with all posterior variances shrinking to near zero. Our model demonstrates the benefits of combining data from multiple studies even with different data types. Furthermore, the approach is not limited to camera trap data. Detection/non-detection data from track surveys or counts from transects could also be combined. Particularly, our model is potentially useful for assessing populations of rare species where large amounts of by-catch datasets are available

Effects of roadside edge on nest predators and nest survival of Asian tropical forest birds

Creation of roadside forest edges can have indirect effects on forest bird communities, as edges can promote species detrimental to forest-nesting birds such as nest predators. We assessed species-specific rates of nest survival of understory birds, relative abundances of specific nest predators and predator-specific rates of nest predation relative to the distance from roadside forest edge in a dry evergreen forest in northeastern Thailand. During the breeding seasons (FebruaryeAugust) of 2014e2016 we searched for nests along two, 1-km transects which ran perpendicular from the edge of a five-lane highway into the forest interior. To assess nest predator species, video cameras were placed on active nests of understory birds and multiple techniques were used to assess the relative abundances of the documented nest predators. We found 306 active nests of 26 species and recorded 179 predation events from 13 species of nest predators. Distance to edge influenced the daily nest survival rates for four of seven focal bird species, with three species having higher survival rates nearer to the edge. Four of six predators had higher relative abundances in the forest interior. Rats and the Common Green Magpie (Cissa chinensis) had higher abundances nearer the edge. Snake detections were too few to assess statistically. Nest predation rates for the top three predators, Northern Pig-tailed Macaque (Macaca leonina), Green Cat Snake (Boiga cyanea) and Crested Goshawk (Accipiter trivirgratus) were significantly greater in the forest interior. The fourth-most important, Common Green Magpie, was the only predator responsible for more nest predation events closer to habitat edge compared to interior. Our study suggests that the impacts of edges on nesting success are highly dependent on the nest predator community and the species-specific responses of predators to edges

Direct Digital Engagement of Patients and Democratizing Health Care

Direct Digital Engagement of Patients and Democratizing Health Car