789 research outputs found

    The Second World War\u27s impact on the progressive educational movement: Assessing its role

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    Evidence found in The New York Times from 1939 to 1945 and corroborating sources are used to demonstrate the impact of the Second World War on the progressive educational movement. We posit that December 7, 1941 initiated the waning of the progressive education movement in the secondary social studies curriculum. Progressive education emphasized a child-centered, experiential curriculum, an issues-centered approach to learning, and a critical analysis of society. Our findings indicate that the educational climate during the Second World War initiated a shift from questioning American institutions to celebrating them. Education became more centralized and many educational organizations were mobilized to support the war effort. Specifically, the secondary social studies curriculum became one of several propaganda vehicles in support of the war. In addition, colleges and universities became training grounds for teachers, defense workers, and soldiers. A war on the home front ensued. The progressive secondary social studies curriculum itself was viewed as placing the nation at risk. While other factors such as the Back-to-Basics movement and the Cold War contributed to the waning of the secondary progressive educational movement, World War Two (WWII) set the decline in motion

    Measuring out quasi-local integrals of motion from entanglement

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    Quasi-local integrals of motion are a key concept underpinning the modern understanding of many-body localisation, a phenomenon in which interactions and disorder come together. Despite the existence of several numerical ways to compute them—and in the light of the observation that much of the phenomenology of many properties can be derived from them—it is not obvious how to directly measure aspects of them in real quantum simulations; in fact, hard experimental evidence is still missing. In this work, we propose a way to extract the real-space properties of such quasi-local integrals of motion based on a spatially-resolved entanglement probe able to distinguish Anderson from many-body localisation from non-equilibrium dynamics. We complement these findings with a rigorous entanglement bound and compute the relevant quantities using tensor networks. We demonstrate that the entanglement gives rise to a well-defined length scale that can be measured in experiments

    Dynamics of a structured slug population model in the absence of seasonal variation

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    We develop a novel, nonlinear structured population model for the slug Deroceras reticulatum, a highly significant agricultural pest of great economic impact, in both organic and non-organic settings. In the absence of seasonal variations, we numerically explore the effect of life history traits that are dependent on an individual's size and measures of population biomass. We conduct a systematic exploration of parameter space and highlight the main mechanisms and implications of model design. A major conclusion of this work is that strong size dependent predation significantly adjusts the competitive balance, leading to non-monotonic steady state solutions and slowly decaying transients consisting of distinct generational cycles. Furthermore, we demonstrate how a simple ratio of adult to juvenile biomass can act as a useful diagnostic to distinguish between predated and non-predated environments, and may be useful in agricultural settings

    Combined Effect of Nano Ferrite and Nano Silica on Properties of Cement Mortar

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    This study investigates the effects of adding nano-ferrite (N.F.) and nano-silica (N.S.) on the mechanical and biological properties of mortar. By assessing four water-to-cement ratios (1-4%), the ideal nanoparticle doses were determined. Results indicated that both N.F. and N.S. significantly increased the mortar\u27s strength at ratios between 1% and 4%, while combinations of N.F. and N.S. improved strength up to 3% and 4% substitution, respectively. The mechanisms of strength enhancement were attributed to nanoparticles acting as fillers and hydration accelerators, which densify the mortar microstructure and promote the production of calcium silicate hydrate (C-S-H) gels. In terms of biological properties, the study examined the antibacterial effects of nano-silica and nano-ferrite. Nano-silica demonstrated greater antibacterial potency against all bacterial strains assessed. Both materials exhibited a stronger antibacterial impact on Gram-positive bacteria (Staphylococcus aureus) compared to Gram-negative bacteria (Escherichia coli), due to differences in cell wall structures. The study emphasizes the importance of optimal nanoparticle dosages and identifies limitations that warrant further research, such as durability and potential downsides at higher concentrations. Despite these challenges, the findings underscore the potential of nanoparticles to enhance mortar performance and suggest promising applications in construction and the development of antibacterial materials. Future research should focus on overcoming these constraints and exploring the practical applications of nanoparticle-enhanced mortar in real-world scenarios

    Efficient rare-event simulation for multiple jump events in regularly varying random walks and compound Poisson processes

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    We propose a class of strongly efficient rare-event simulation estimators for random walks and compound Poisson processes with a regularly varying increment/jump-size distribution in a general large deviations regime. Our estimator is based on an importance sampling strategy that hinges on a recently established heavy-tailed sample-path large deviations result. The new estimators are straightforward to implement and can be used to systematically evaluate the probability of a wide range of rare events with bounded relative error. They are “universal” in the sense that a single importance sampling scheme applies to a very general class of rare events that arise in heavy-tailed systems. In particular, our estimators can deal with rare events that are caused by multiple big jumps (therefore, beyond the usual principle of a single big jump) as well as multidimensional processes such as the buffer content process of a queueing network. We illustrate the versatility of our approach with several applications that arise in the context of mathematical finance, actuarial science, and queueing theory

    Effect of Ghrelin Injection on Blood and Body Composition in Rats

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    Ghrelin has been reported to cause hyperglycemia in humans and adiposity in rodents. The objective of trial one was to test the effects of ghrelin on blood and body composition in rats. The objective of trial two was to evaluate the effect of two doses of ghrelin on blood and body composition. Trial One: Adult male Sprague Dawley rats were administered 1 ÎĽg/rat ghrelin in 0.15 M NaCl or vehicle (0.15 M NaCl) every morning for 30 days. The terminal blood sample was analyzed for glucose, urea nitrogen, and nonesterified fatty acids concentrations. The carcasses were analyzed for total lipid and nitrogen content. Blood urea nitrogen, nonesterified fatty acids, carcass total lipid, and carcass total nitrogen concentrations were similar for the control and ghrelin groups. However, blood glucose concentration tended to be higher in the ghrelin group than in the control. Ghrelin administered at 2.4 ÎĽg/kg did not cause adiposity in rats but did tend to cause hyperglycemia. Trial Two: Adult male Sprague Dawley rats were administered 1 ÎĽg/rat ghrelin, 20 ÎĽg/rat ghrelin, or vehicle every morning for 30 days. The terminal blood sample was analyzed for glucose and cholesterol concentrations. The carcasses were analyzed for total lipid and nitrogen content. Carcass total nitrogen concentrations were similar for the control and ghrelin groups. Carcass percent lipid was higher in the 1 ÎĽg/rat ghrelin group (P = 0.04). Feed intake among all three groups was the same. Blood glucose concentration, however, tended to be higher in the ghrelin groups than in the control. Blood cholesterol concentration was lower in the ghrelin treated animals. In the second trial, ghrelin injection of 1 ÎĽg/rat did cause an increase in adiposity whereas 20 ÎĽg/rat did not cause an increase in adiposity. Both ghrelin treatments tended to cause hyperglycemia in rats. In summary, ghrelin increased blood glucose concentration without changing body composition

    Open Gromov-Witten Invariants of Toric Calabi-Yau 3-Folds

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    We present a proof of the mirror conjecture of Aganagic-Vafa [arXiv:hep-th/0012041] and Aganagic-Klemm-Vafa [arXiv:hep-th/0105045] on disk enumeration in toric Calabi-Yau 3-folds for all smooth semi-projective toric Calabi-Yau 3-folds. We consider both inner and outer branes, at arbitrary framing. In particular, we recover previous results on the conjecture for (i) an inner brane at zero framing in the total space of the canonical line bundle of the projective plane (Graber-Zaslow [arXiv:hep-th/0109075]), (ii) an outer brane at arbitrary framing in the resolved conifold (Zhou [arXiv:1001.0447]), and (iii) an outer brane at zero framing in the total space of the canonical line bundle of the projective plane (Brini [arXiv:1102.0281, Section 5.3]).Comment: 39 pages, 11 figure

    Synthesis Nano Zinc Oxide Materials and Their Activity on Fungus Growth

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    In this study Zinc oxide Nano particles was synthesized by employing sol-gel technique to explore novel antifungal agents to beat the developed of fungi resistance to many conventional fungicides .Prepared of Zinc oxide Nano particles were investigated via using Scanning Electron Microscopy (SEM, the VEGA Easy Probe), X ray powder diffraction (XRD) , FTIR spectrum, The antifungal properties of ZnO nanoparticles were tested against Fussarium spp., Alternaria spp. , Penicillium spp. , and Aspergillus spp. by using agar diffusion method. The percentage of growth was lowest comparison with control for all types of fungi when used zinc oxide Nano in different concentration
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