115,231 research outputs found

    Student Perceptions of Secondary Science Teachers’ Practices Following Curricular Change

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    Inquiry-based teaching has emerged as a highly valued strategy in science education. In Portugal, the science curriculum has been redesigned in order to promote such teaching. This implies substantial change in teacher practice. It is therefore important to understand students’ perceptions of teacher practice. Aim: In this study, we describe student perception of teacher practices and look for associations between the perceptions and student motivation. Method: Three low-achieving, secondary-level science classes were studied. Motivation was measured by two scales (Intrinsic and Extrinsic); Perceptions were measured in four dimensions. Results: Significant associations (p < .05) were observed between intrinsic motivation and (a) Perception of the use of Laboratory Work; (b) Perception of Science-Technology-Society and (c) Perceived Student Autonomy. No association was noted between intrinsic motivation and the Perception of Teacher as Facilitator. Conclusions: Results are generally consistent with previous literature. Teacher professional development lags behind curricular change. Teachers require new conceptions of assessment.Projeto financiado pelo CIEFCU

    Identifying Consumer Perceptions of Fresh-market Blackberries

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    Blackberries are grown worldwide for commercial fresh markets, but there is limited information on consumer perceptions of this fruit. In this study, physiochemical and consumer sensory attributes of three Arkansas-grown fresh-market blackberry genotypes were evaluated and consumer perceptions of fresh-market blackberries were also investigated though an online survey. Two cultivars (Natchez and Ouachita) and one advanced selection (A-2418) were evaluated for compositional and nutraceutical analysis and consumer sensory analysis. Natchez had the highest berry weight, length, drupelets and pyrenes/berry, and pyrene weight/berry. Ouachita had the highest soluble solids content (11.9%), pH (3.18) and soluble solids/titratable acidity ratio (10.92). There were no significant differences between genotypes for titratable acidity, organic acids, sugars, and most of the nutraceuticals. In a sensory panel (n = 80) of these genotypes, consumers rated Natchez highest in overall impression, overall flavor, and sweetness, and Natchez was ranked as the most liked blackberry more often than Ouachita or A-2418 on a 9-point verbal hedonic liking scale and 5-point Just About Right scale. An online consumer survey (n = 879) was done to gain information on consumers’ opinions and habits relating to fresh-market blackberries. Results indicated the most important factors to influence blackberry purchases are the freshness of the berries, the type and size of package, the uniformity of berry color, and the price. Results also suggested consumers prefer larger sized blackberries and blackberries with an oblong shape. Identifying marketability attributes of fresh-market blackberries helps provide information to advance breeding efforts for fruit with commercial potential

    Towards general spatial intelligence

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    The goal of General Spatial Intelligence is to present a unified theory to support the various aspects of spatial experience, whether physical or cognitive. We acknowledge the fact that GIScience has to assume a particular worldview, resulting from specific positions regarding metaphysics, ontology, epistemology, mind, language, cognition and representation. Implicit positions regarding these domains may allow solutions to isolated problems but often hamper a more encompassing approach. We argue that explicitly defining a worldview allows the grounding and derivation of multi-modal models, establishing precise problems, allowing falsifiability. We present an example of such a theory founded on process metaphysics, where the ontological elements are called differences. We show that a worldview has implications regarding the nature of space and, in the case of the chosen metaphysical layer, favours a model of space as true spacetime, i.e. four-dimensionality. Finally we illustrate the approach using a scenario from psychology and AI based planning

    Glass Bellies and Artificial Wombs: Gender, Science, and Reproduction in Early Modern Alchemical Performance

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    In this essay, I use the glass belly or vessel as a framework for examining the intersection of science, performance, and gender in the early modern period. I begin with the example of the glass belly because of how its form and functions intersect these areas of inquiry through early modern alchemy, which I argue can be examined *as* science in performance—in other words, alchemy serves as exemplar of the performativity of science. If early modern scholars have used performance to represent “the deceptive, hollow, and illusory nature of the theatrical, even as it conjures the real into being,” alchemy serves as a particularly pertinent case. Alchemy is often dismissed in our modern day as an illusory science, one that but mimics the more sophisticated techniques of scientific methodology and which is defined by its reputation as fraudulent and deceptive, which was not entirely accurate to its time. But insofar as we might define science as a body of knowledge—scientia—and a set of practices—techne—alchemy was very much constituted by both. Furthermore, precisely because of the gendering that occurred with the glass vessels used in alchemical science (and would continue to be used as laboratory vessels in the growing field of chemistry), I argue that the history of alchemy can provide a useful framework for mapping out the early, gendered relationships between science and performance

    Extending Human Perception of Electromagnetic Radiation to the UV Region through Biologically Inspired Photochromic Fuzzy Logic (BIPFUL) Systems.

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    Photochromic Fuzzy Logic Systems have been designed that extend human visual perception into the UV region. The systems are founded on a detailed knowledge of the activation wavelengths and quantum yields of a series of thermally reversible photochromic compounds. By appropriate matching of the photochromic behaviour unique colour signatures are generated in response differing UV activation frequencies

    Senior secondary students’ perception of the nature of the atom in Obio Akpor local government area of Rivers state, Nigeria

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    The study investigated Senior Secondary (SS) Students’ perception about the nature of the atom. Phenomenographic approach was adopted. Two thousand five hundred and twenty (2,520) SS3 Chemistry students from government owned schools in Obio/Akpor Local Government Area of Rivers State, Nigeria, volunteered to participate in the study. The instruments used in the study were a Perception Rating Scale Questionnaire (PRSQ) on the nature of atoms and an Atomic Theory Test (ATT). Overall findings of the study revealed that 60% of the items in PRSQ showed description of the atom by the students as a constituent of matter, 13.3% indicating constitution of the atom as a particle and 26.6% described the atom in terms of shape (model). It was further observed that 10.2% of the students agreed with the statements concerning the atom as a constituent of matter, the constitution of the atom and the model of an atom. With the students’ knowledge about the atomic theory, they were able to associate the atom with such concepts as electrons, protons, neutrons, electronic configuration, nucleus, atomic number, shells and mass number. The implications of these findings were discussed in the study

    Thoughts about a General Theory of Influence in a DIME/PMESII/ASCOP/IRC2 Model

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    The leading question of this paper is: “How would influence warfare (“iWar”) work and how can we simulate it?” The paper discusses foundational aspects of a theory and model of influence warfare by discussing a framework built along the DIME/PMESII/ASCOP dimension forming a prism with three axes. The DIME concept groups the many instruments of power a nation state can muster into four categories: Diplomacy, Information, Military and Economy. PMESII describes the operational environment in six domains: Political, Military, Economic, Social, Information and Infrastructure. ASCOPE is used in counter insurgency (COIN) environments to analyze the cultural and human environment (aka the “human terrain”) and encompasses Areas, Structures, Capabilities, Organization, People and Events. In addition, the model reflects about aspects of information collection requirements (ICR) and information capabilities requirements (ICR) - hence DIME/PMESII/ASCOP/ICR2. This model was developed from an influence wargame that was conducted in October 2018. This paper introduces basic methodical questions around model building in general and puts a special focus on building a framework for the problem space of influence/information/hybrid warfare takes its shape in. The article tries to describe mechanisms and principles in the information/influence space using cross discipline terminology (e.g. physics, chemistry and literature). On a more advanced level this article contributes to the Human, Social, Culture, Behavior (HSCB) models and community. One goal is to establish an academic, multinational and whole of government influence wargamer community. This paper introduces the idea of the perception field understood as a molecule of a story or narrative that influences an observer. This molecule can be drawn as a selection of vectors that can be built inside the DIME/PMESII/ASCOP prism. Each vector can be influenced by a shielding or shaping action. These ideas were explored in this influence wargame

    Measuring the World: Olfaction as a Process Model of Perception

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    How much does stimulus input shape perception? The common-sense view is that our perceptions are representations of objects and their features and that the stimulus structures the perceptual object. The problem for this view concerns perceptual biases as responsible for distortions and the subjectivity of perceptual experience. These biases are increasingly studied as constitutive factors of brain processes in recent neuroscience. In neural network models the brain is said to cope with the plethora of sensory information by predicting stimulus regularities on the basis of previous experiences. Drawing on this development, this chapter analyses perceptions as processes. Looking at olfaction as a model system, it argues for the need to abandon a stimulus-centred perspective, where smells are thought of as stable percepts, computationally linked to external objects such as odorous molecules. Perception here is presented as a measure of changing signal ratios in an environment informed by expectancy effects from top-down processes

    Color Engineering of Silicon Nitride Surfaces to Characterize the Polydopamine Refractive Index

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    A simple methodology to generate polydopamine (PDA) surfaces featured with color due to thin-film interference phenomena is presented. It is based on depositing ultra-thin films of polydopamine on a Si/Si 3 N 4 wafer that exhibits an interferential reflectance maximum right at the visible/UV boundary (∼400 nm). Therefore, a small deposit of PDA modifies the optical path, in such manner that the wavelength of the maximum of reflectance red shifts. Because the human eye is very sensitive to any change of the light spectral distribution at the visible region, very small film thickness changes (∼30 nm) are enough to notably modify the perceived color. Consequently, a controlled deposit of PDA, tune the color along the whole visible spectrum. Additionally, good quality of PDA deposits allowed us to determine the refractive index of polydopamine by ellipsometry spectroscopy. This data can be crucial in confocal skin microscopic techniques, presently used in diagnosis of skin tumors.Fil: Vega Moreno, Milena Amparo. Universidad de Salamanca; EspañaFil: Martín del Valle, Eva M.. Universidad de Salamanca; EspañaFil: Perez, Maximiliano Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Haedo; ArgentinaFil: Pecharromán, Carlos. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia de los Materiales de Barcelona; EspañaFil: Marcelo, Gema. Universidad de Salamanca; Españ
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