452 research outputs found
Embodied curriculum mapping as a foundation for critical self-reflection and culture change
No full textThis article describes a first-person qualitative research study to understand how common pedagogical approaches and cultural learning environments in STEM impact individuals. Prior to the study, the author observed that many students who were successful in advanced undergraduate neuroscience courses reported having struggled academically, socially, or emotionally in introductory STEM courses. The objective was to generate new ideas for approaches to address high rates of student attrition from introductory STEM courses related to this full range of issues through curriculum development. The author, a neurobiologist and tenured faculty member at the institution, audited four introductory STEM courses: Introduction to Cellular and Molecular Biology, Atoms & Molecules, Calculus 1, and Introductory Physics 2: Electromagnetism, Optics, and Modern Physics, offered by tenured colleagues in four different departments. A total of approximately 600 hours was spent by the author attending lectures, participating in classroom activities, completing homework, and studying for assessments. Homework, quizzes, and exams were marked by the course faculty using the same criteria as were applied for student work. In addition to measures of academic performance collected through the normal assessments, the author made note of her own emotional responses throughout the course of the study, which is why the process was dubbed ‘embodied’ curriculum mapping. The emotional responses revealed high levels of emotional stress associated with assessment, sensitivity to disciplinary boundary reinforcement, and a complex role of social and academic identity in all aspects of the experience. Given the first-person nature of the study, the potential future generalizability of the findings must be considered in light of the various revealed aspects of identity and experience of the author and subjected to further study using a broader range of empirical methodologies. The focus of this article’s conclusions and recommendations is therefore the impact of the process on the author and the potential for a similar process to serve as a foundation for critical self-reflection and learning for other STEM educators. The author recommends the process as a generative tool for pedagogical innovation and building faculty capacity for culture change in STEM
Child labor : cause, consequence, and cure, with remarks on International Labor Standards
No full textAt least 120 million of the world's children aged 5 to 14 worked full-time in 1995, most of them under hazardous, unhygienic conditions, for more than 10 hours a day. This is an old problem worldwide but particularly so in Third World countries in recent decades. What has changed, with globalization, is our awareness of these child laborers. (The International Labor Organization distinguishes between"child work,"which could include light household chores and could have some learning value, and"child labor,"a pejorative phrase.) By bringing together the main theoretical ideas, the author hopes to encourage both more theoretical research and empirical work with a better theoretical foundation. Among other things, the author observes that: a) The problem is most serious in Africa, where the child-labor participation rate is 26.2 percent. The rate is 12.8 percent in Asia. But since 1950, the trend is a decline in that participation rate worldwide. For most Latin American countries, the decline is notable but less marked than in Asia. In large parts of Africa, including Ethiopia, the problem has been extremely persistent, but even there the trend is downward. b) Child labor has not always been considered evil, and there is no consensus on why it began to decline. In some (not all) countries legislative acts declared it illegal, in some there were rules about compulsory education, and increasing prosperity generally made families less likely to experience poverty if their children weren't working. c) Mandating compulsory education is regarded as more effective than outlawing child labor, because attendance at school is easier to monitor, but some experts believe economic progress is the answer to the problem. The justification for many interventions is that the state is more concerned about the well-being of children than parents are; the author believes such an assumption to be wrong when child labor occurs as a mass phenomenon rather than as isolated abuse. The author argues that, in some economies, the market for labor may exhibit multiple equilibria, with one equilibrium having low adult wage and a high incidence of child labor and another equilibrium exhibiting high adult wage and no child labor. The model is used to provide a framework for analyzing the role of international labor standards.Labor Standards,Children and Youth,Street Children,Labor Policies,Environmental Economics&Policies,Street Children,Children and Youth,Youth and Governance,Labor Standards,Educational Policy and Planning
Identity of Endogenous NMDAR Glycine Site Agonist in Amygdala Is Determined by Synaptic Activity Level
No full textMechanisms of NMDA receptor-dependent synaptic plasticity contribute to the acquisition and retention of conditioned fear memory. However, synaptic rules which may determine the extent of NMDA receptor activation in the amygdala, a key structure implicated in fear learning, remain unknown. Here we show that the identity of the NMDAR glycine site agonist at synapses in the lateral nucleus of the amygdala may depend on the level of synaptic activation. Tonic activation of NMDARs at synapses in the amygdala under low-activity conditions is supported by ambient D-serine, whereas glycine may be released from astrocytes in response to afferent impulses. The release of glycine may decode the increases in afferent activity levels into enhanced NMDAR-mediated synaptic events, serving an essential function in the induction of NMDAR-dependent long-term potentiation in fear conditioning pathways.Version of Recor
Error estimate for a corrected Clenshaw–Curtis quadrature rule
No full textA new endpoint-corrected rule for the Clenshaw–Curtis (C–C) quadrature is proposed to improve the convergence rate. The error behavior is compared, analytically and numerically, to the C–C rule and related quadrature rules: the Fejér rules of the first and second kind and the Basu rule.journal articl
The economic and law of rent control
No full textThe authors construct a model of second-generation rent control, describing a regime that does not permit rent increases for sitting tenants--or their eviction. When an apartment becomes vacant, however, the landlord is free to negotiate a new contract with a higher rent. They argue that this stylized system is a good (though polar) approximation of rent control regimes that exist in many cities in India, the United States, and elsewhere. Under such a regime, if inflation exists, landlords prefer to rent to tenants who plan to stay only a short time. The authors assume that there are different types of tenants (where"type"refers to the amount of time tenants stay in an apartment) and that landlords are unable to determine types before they rent to a tenant. Contracts contingent on departure date are forbidden, so a problem of adverse selection arises. Short stayers are harmed by rent control while long-term tenants benefit. In addition, the equilibrium is Pareto inefficient. The authors show that when tenant types are determined endogenously (when a tenant decides how long to stay in one place based on market signals) in the presence of rent control, there may be multiple equilibria, with one equilibrium Pareto-dominated by another. In other words, many lifestyle choices are made based on conditions in the rental housing market. One thing rent control may do is decrease the mobility of the labor force, because tenants may choose to remain in a city where they occupy rent-controlled apartments rather than accept a higher-paying job in another city. The authors show that abolishing the rent control regime can do two things: shift the equilibrium to a better outcome and result in lower rents, across the board.International Terrorism&Counterterrorism,Economic Theory&Research,Health Economics&Finance,Housing&Human Habitats,Payment Systems&Infrastructure,International Terrorism&Counterterrorism,Banks&Banking Reform,Economic Theory&Research,Health Economics&Finance,Housing&Human Habitats
Impact of Time-dependent Annealing on TiO2 Films for CMOS application
No full textPost-deposition annealing (PDA) is the inherent part of sol-gel fabrication process to achieve the optimum device performance, especially in CMOS applications. The annealing removes the oxygen vacancies and improves the structural order of dielectric films. The process also reduces the interface related defects and improves the interfacial properties. In this work, we have integrated the sol-gel spin-coating deposited high-TiO2 films in MOS. The films are fired at 400 degrees C for the duration of 20, 40, 60 and 80 min. The thicknesses of the films were found to be of similar to 30 nm using ellipsometry. The (Al/TiO2/p-Si) devices were examined with current-voltage (I-V) and capacitance-voltage (C-V) at room temperature to understand the influence of firing time. The C-V and I-V characteristic showed a significant dependence on annealing time such as variation in dielectric constant and leakage current. The accumulation capacitance (Cox), dielectric constant (kappa) and the equivalent oxide thickness (EOT) of the film fired for 60 min were found to be 458 pF, 33, and 4.25nm, respectively with a low leakage current density (1.09 10(-6) A/cm(2)) fired for 80 min at + 1 V
Fouling Indices for Quantification of Natural Organic Matter Fouling and Cleaning in Ceramic and Polymeric Membrane Systems
No full textA key challenge in membrane system is to understand how operating pressure and water temperature may impact fouling and subsequent cleaning in relationship to NOM. Further there is limited data to ascertain if ultrafiltration (UF) polymeric and ceramic systems will respond in similar or different manners to NOM fouling which then further impacts how respective systems need to be cleaned. This research investigated the application of the MFI-UF in complement with the UMFI for assessing NOM fouling and cleaning under changes in filtration conditions with both ceramic and polymeric membranes systems. The research showed that all NOM types exhibited higher MFI-UF values, and therefore, higher fouling propensity as pressure increased from 1 to 3 bars and water temperature decreased from 35°C to 5°C indicating the effect of pressure and temperature on the MFI-UF fouling prediction. The NOM fouling potential order was consistent at different temperature which was the highest for the NOM mixture and proteins (BSA) followed by alginate and lastly humic acid. Variation in feed water temperature in polymeric and ceramic membrane systems demonstrated negative impacts on NOM fouling and cleaning. NOM fouling increased as water temperature decreased from 20°C to 5°C while fouling decreased as temperature increased from 20°C to 35°C. The UMFI analysis showed that irreversible NOM fouling ratios increased at cold water condition (5 °C), along with decreased in backwash and chemical cleaning effectiveness of both membrane types. The UMFI results obtained in the polymeric and ceramic UF systems demonstrated useful fit with the MFI-UF prediction for establishing NOM fouling trend and order with temperature. Under an equivalent fouling and cleaning conditions, NOM fouling order of a ceramic UF membrane was found to be similar to their polymeric counterparts. However, the ceramic UF demonstrated better performance in terms of backwashing, thus, lower irreversible fouling. Chemical cleaning of a ceramic UF membrane using O3 CIP for 1 hour at a ratio of 0.50 mgO3/mgC demonstrated higher reduction of irreversible fouling of hydrophobic and hydrophilic NOM fractions and lower sensitivity to water quality conditions compared to 4 hours cleaning using combined NaOCl and NaOH CIP
On the rate of approximation in the random sum CLT for dependent variables
No full textsummary:Capital and lower-case approximations of the expected value of a class of smooth functions of the normalized random partial sums of dependent random variables by the expectation of the corresponding functions of Gaussian random variables are established. The same types of approximation are also obtained for dependent random vectors. This generalizes and improves previous results of the author (1980) and Rychlik and Szynal (1979)
Band Alignment and Electrical Investigations of Ultra-Thin Al2O3 on Si by E-beam Evaporation
No full textThe continuous downscaling leads the search of high-gate dielectrics. The films amorphous in nature offered good mechanical flexibility, smooth surfaces and better uniformity associated with low leakage current density. In this work, 16 nm thick amorphous Al2O3 films on silicon substrate are fabricated by E-beam evaporation. The high value of refractive index (1.76) extracted from ellipsometry analysis directs the deposition of compact film. The AFM analysis reveal a flat surface with small RMS surface roughness 1.5 angstrom. The band gap is extracted from O-1s electron loss spectra and was found 6.7 eV and band alignment of Al2O3/Si is derived from the UPS measurements. The films are incorporated in Metal Insulator -Semiconductor (MIS) capacitor to perform the electrical measurement. The flat band voltage (V-FB), dielectric constant () and oxide trapped charges (Q(ot)) extracted from high frequency (1 MHz) C-V curve are - 0.4 V, 8.4 and 2 x 10(11) cm(-2), respectively. The small flat band voltage - 0.4 V, narrow hysteresis and very little frequency dispersion suggest an exceptional good Al2O3/Si interface with small quantity of trapped charges in the oxide. The leakage current density was 4.27 x 10(-8) A/cm(2) at 1 V. The moderate dielectric constant and low leakage current density with ultra-smooth surface is quite useful towards its application in future CMOS and memory devices
Group Equivariant Video Action Recognition: Making action-recognition networks equivariant to temporal direction and discrete spatial rotations
No full textThis work applies the theory of group equivariance to the domain of video action recognition replacing standard 3Dconvolutions with group convolutions which are equivariant to temporal direction, and multiples of 90-degree spatial rotations. We propose a temporal direction symmetry group T2 and extend the standard planar rotations group to three dimensions to form a 3D group that is equivariant to discrete 90-degree spatial rotations. We analyse the efficacy of using these 3D-G-CNNs as drop-in replacements in 3D networks by evaluating synthesized datasets containing handwritten MNIST digits moving over a black background, as well as popular action recognition datasets UCF-101and HMDB-51, and comparing the results against the performance of the standard 3D CNNs on the datasets.Computer Scienc
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