1,510 research outputs found

    The Effects of Pre-Trial Event Stimulus Properties on Timing in the Peak Interval Procedure

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    In the peak interval procedure, intruded conditioned stimuli produce shifts in peak/middle time towards later values, regardless of whether these stimuli are presented prior to or during the timing signal. Although the effects of during-trial stimulus properties—temporal location, duration, and salience—have been previously reported, no research exists on how before-trial stimulus properties influence the extent of shifts in middle time. In the present study, we manipulated within subjects both the temporal location and type (i.e., cue alone, response-independent reinforcer alone, or cue and response-contingent reinforcer together) of the pre-trial event. An individual-trial analysis suggested that the type of stimulus event governs the extent of the shifts in middle time, with larger shifts observed on trials preceded by a reinforcer, either alone or in conjunction with a conditioned cue, than on trials that were preceded by the conditioned cue alone. These results indicate that reinforcers can disrupt timing by means other than a reset of working memory—an account that is common in prior investigations of reinforcers in timing tasks. In addition, we found a time-dependent effect of the event, with larger shifts in middle time engendered by events more contiguous to the timing signal, suggesting that the postcue effect dissipates following the offset of the event

    Unsupervised Deep Single-Image Intrinsic Decomposition using Illumination-Varying Image Sequences

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    Machine learning based Single Image Intrinsic Decomposition (SIID) methods decompose a captured scene into its albedo and shading images by using the knowledge of a large set of known and realistic ground truth decompositions. Collecting and annotating such a dataset is an approach that cannot scale to sufficient variety and realism. We free ourselves from this limitation by training on unannotated images. Our method leverages the observation that two images of the same scene but with different lighting provide useful information on their intrinsic properties: by definition, albedo is invariant to lighting conditions, and cross-combining the estimated albedo of a first image with the estimated shading of a second one should lead back to the second one's input image. We transcribe this relationship into a siamese training scheme for a deep convolutional neural network that decomposes a single image into albedo and shading. The siamese setting allows us to introduce a new loss function including such cross-combinations, and to train solely on (time-lapse) images, discarding the need for any ground truth annotations. As a result, our method has the good properties of i) taking advantage of the time-varying information of image sequences in the (pre-computed) training step, ii) not requiring ground truth data to train on, and iii) being able to decompose single images of unseen scenes at runtime. To demonstrate and evaluate our work, we additionally propose a new rendered dataset containing illumination-varying scenes and a set of quantitative metrics to evaluate SIID algorithms. Despite its unsupervised nature, our results compete with state of the art methods, including supervised and non data-driven methods.Comment: To appear in Pacific Graphics 201

    Oviposition and egg quality traits of dwarf and naked neck layers

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    Oviposition and egg quality traits were studied in dwarf and naked neck layers in Maputo (Mozambique) during a 28-d period at 35 weeks of age. Birds were caged individually in a laying house with natural light and ventilation. Average daylight length during the study was 11.2 hr and minimum and maximum temperature was 19.6 °C and 30.1 °C, respectively. The main results show that the sex-linked dwarfing gene (dw) increased the mean interval and time of oviposition, and reduced the sequence length and rate of lay. A bimodal distribution of oviposition intervals was observed in the dwarf population. No meaningful effect of the naked neck (Na) gene could be seen on oviposition traits. The dw gene also reduced the egg and components weight as well as the height of the albumen. The Na gene was associated with increased yolk weight and reduced albumen height. Keywords: Naked neck, Dwarf, Oviposition, Egg quality, Laying hens South African Journal of Animal Science Vol.33(2) 2003: 105-11

    Cauchy's residue theorem for a class of real valued functions

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    Let [a,b][a,b] be an interval in R\mathbb{R} and let FF be a real valued function defined at the endpoints of [a,b][a,b] and with a certain number of discontinuities within [a,b][a,b] . Having assumed FF to be differentiable on a set [a,b]\E[a,b] \backslash E to the derivative ff, where EE is a subset of [a,b][a,b] at whose points FF can take values ±\pm \infty or not be defined at all, we adopt the convention that FF and ff are equal to 0 at all points of EE and show that KHvtabf=F(b)F(a)\mathcal{KH-}vt\int_{a}^{b}f=F(b) -F(a)%, where KH\mathcal{KH-} vtvt denotes the total value of the \textit{% Kurzweil-Henstock} integral. The paper ends with a few examples that illustrate the theory.Comment: 6 page

    Fisheries rehabilitation in post-tsunami Aceh: Status and needs from participatory appraisals

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    The widespread and long-term nature of the tsunami damage in Aceh province, Indonesia has threatened the continued use of coastal and fisheries resources. This article describes the application of the Rapid Appraisal of Fisheries Management System (RAFMS) methodology and presents key findings from the participatory appraisals in 15 study sites. The focus is on changes in the number and types of fishing boats and fishing effort, consumption and marketing flow patterns and community perspectives on livelihood options. The level of aid (for new boats), mainly from international organizations, has been unevenly distributed with the number of boats in 13 of 15 villages still being well below the pre-tsunami levels. A focus on supplying small vessels may put increased fishing pressure on the near-shore zone. Consumption data and marketing flows suggest that most fishing villages are supplying outside markets and adding considerably to the wider food security of the province. Despite the tsunami, marine fisheries-related livelihoods are still preferred, although there are indications for the potential expansion of livelihoods into the culture of new species. Alternative resource-based livelihoods need to be tested and refined to fit the needs of the current conditions in Aceh to provide viable options for eliminating hunger and reducing poverty

    A trophic model of the coastal fisheries ecosystem off the west coast of Sabah and Sarawak, Malaysia

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    A mass-balance steady-state trophic model of the coastal fisheries ecosystem off the West Coasts of Sabah and Sarawak, Malaysia (10 - 60 m depth) was constructed using the Ecopath software. The ecosystem models were partitioned into 29 ecological/trophic groups. The input values (e.g. biomasses) for selected groups were obtained from the research (trawl) surveys conducted in the area in 1972. The estimated mean trophic level of the fisheries catch for both models is about 3.3. The biomass values obtained from Ecopath when compared with the estimates of the fishery catch indicate a low level of exploitation of coastal fisheries resources in 1972.Fishery resources, Demersal fisheries, Fishery surveys, Biomass, Population density, Shrimp fisheries, Catch/effort, Trawling, Mathematical models, Coastal fisheries, Marine fisheries, Ecosystems, Trophic structure, ISEW, Malaysia, Sarawak, ISEW, Malaysia, Sabah,

    Relación angular radiológica de las superficies articulares de la tibia en sujetos asintomáticos

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    Se efectuó un estudio radiológico para determinar la relación angular existente entre las superficies articulares proximal y distal de 108 tibias correspondientes a 54 pacientes asintomáticos, de edades entre 14 y 72 años (media: 29,8). La medición se llevó a cabo con un «cobbometro» de Oxford en proyección anteroposterior y lateral. El ángulo medio entre ambas superficies fue de 3,3 ± 2,6° (intervalo de confianza al 95%: 2,8-3,8°) en proyección anteroposterior y de 5,5 ± 3,9° (intervalo de confianza: 4,7-6,3°) en proyección lateral. Cuando se consideró para cada paciente, la diferencia media de esta relación angular entre las tibias derechas e izquierdas fue inferior a 0,5° en ambas proyecciones.The angular relationship between proximal and distal articular surfaces was determined, through an Oxford Cobbometer, in 108 tibiae of 54 asymptomalic patients aging 14 to 72 years (mean: 30). Mean angle between both surfaces was 3.3 ± 2.6° (95% confidence interval: 2.8-3.8°) for the anteroposterior view and 5.5 ± 3.9° (95% confidence interval: 4.7-6.3°) for the lateral view. When considered individually for each patient, mean difference of this angular relationship among right and left tibiae was lesser than 0.5° for both projections

    Productive performance of naked neck, frizzle and dwarf laying hens under various natural climates and two nutritional treatments

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    The productive performance of major genes for feather reduction (naked neck and frizzle) and body size reduction (dwarf) in a dual-purpose layer strain was evaluated in the subtropical coastal region of southeast Africa (Maputo, Mozambique). The experimental material consisted of ight different genetic groups, two diets (14.4 and 16.2% crude protein) and two climatic seasons. Birds were caged individually in a laying house with natural light and ventilation. Traits measured were: temperature and relative humidity, body weight, age at first egg, egg number and weight, feed intake and mortality. The following were calculated: persistence, egg mass, feed efficiency, feed conversion, biological efficiency (EMD/BW 0.75) and productivity (EN/BW 0.75). The main results show that: (1) none of the feather-reducing genes significantly improved egg production or feed efficiency, although the naked neck (Na) excelled in terms of biological efficiency and productivity; (2) the dwarf gene (dw) was associated with delayed sexual maturity, production of fewer and lighter eggs, higher persistence, better feed conversion and higher survivability; (3) elevated temperatures restrained voluntary feed intake, egg number and weight, and body weight gain; (4) the lower dietary protein content resulted in decreased body weight. It was concluded that the genes were not equally responsive to the environments, which offers the opportunity for selective breeding. South African Journal of Animal Science, Vol 31, Issue 3, Oct – Dec (2001): pp.174-180Key Words Temperature, Poultry, Naked neck, Frizzle, Dwarf, Egg production, Laying hen
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