587 research outputs found
A Critical Review of AntiâBullying Programs in North American Elementary Schools
BACKGROUNDBullying behavior is a concern among schoolâaged youth and antiâbullying programs have been implemented in schools throughout North America. Most antiâbullying programs are delivered to adolescent youth because antisocialâaggressive behaviors are typically associated with this developmental stage. This paper is a review of empirically evaluated schoolâbased bullying prevention and intervention programs in North American elementary schools.METHODSWe conducted a systematic, critical review of bullying prevention programming. Data were analyzed to determine the study method, intervention components, measurement of bullying, aggression, or peer victimization, outcomes measured, and results.RESULTSOur review resulted in the identification of 10 interventions aimed at youth in grades Kâ6 enrolled in North American elementary schools. Effective intervention strategies targeted a variety of bullying behaviors using diverse mechanisms and included a schoolâand communityâwide approach. Direct outcomes of the reviewed evaluations were centered on bullying, aggression, and victimization. Indirect outcomes of review evaluations included strategies for bystanders, school achievement, perceived school safety, and knowledge or attitudes about bullying.CONCLUSIONSRecommendations for promising practices in effective bullying intervention programming are offered. The review concludes with suggestions for supporting school health staff and inâservice teachers drawn from the body of research, and offers direction for future study.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151360/1/josh12814_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151360/2/josh12814.pd
Resonant phonon coupling across the La{1-x}Sr{x}MnO{3}/SrTiO{3} interface
The transport and magnetic properties of correlated La{0.53}Sr{0.47}MnO{3}
ultrathin films, grown epitaxially on SrTiO{3}, show a sharp cusp at the
structural transition temperature of the substrate. Using a combination of
experiment and theory we show that the cusp is a result of resonant coupling
between the charge carriers in the film and a soft phonon mode in the SrTiO{3},
mediated through oxygen octahedra in the film. The amplitude of the mode
diverges towards the transition temperature, and phonons are launched into the
first few atomic layers of the film affecting its electronic state
Unsaturation of vapour pressure inside leaves of two conifer species
Stomatal conductance (gs) impacts both photosynthesis and transpiration, and is therefore fundamental to the global carbon and water cycles, food production, and ecosystem services. Mathematical models provide the primary means of analysing this important leaf gas exchange parameter. A nearly universal assumption in such models is that the vapour pressure inside leaves (ei) remains saturated under all conditions. The validity of this assumption has not been well tested, because so far ei cannot be measured directly. Here, we test this assumption using a novel technique, based on coupled measurements of leaf gas exchange and the stable isotope compositions of CO2 and water vapour passing over the leaf. We applied this technique to mature individuals of two semiarid conifer species. In both species, ei routinely dropped below saturation when leaves were exposed to moderate to high air vapour pressure deficits. Typical values of relative humidity in the intercellular air spaces were as low 0.9 in Juniperus monosperma and 0.8 in Pinus edulis. These departures of ei from saturation caused significant biases in calculations of gs and the intercellular CO2 concentration. Our results refute the longstanding assumption of saturated vapour pressure in plant leaves under all conditions.We thank Meisha Holloway-Phillips, Alex Cheesman, Hilary Stuart-Williams, and Michael Roderick for helpful discussions and comments on the manuscript; and Lily Cohen, Adam Collins, and Turin Dickman for measurement and field assistance. This research was supported by Australian Research Council Discovery Grants DP1097276 and DP150100588
CFRP strengthened continuous concrete beams.
yesThis paper reports the testing of five reinforced concrete continuous beams strengthened in flexure with externally bonded carbon-fibre-reinforced polymer (CFRP) laminates. All beams had the same geometrical dimensions and internal steel reinforcement. The main parameters studied were the position and form of the CFRP laminates. Three of the beams were strengthened using different arrangements of CFRP plate reinforcement, and one was strengthened using CFRP sheets. The performance of the CFRP-strengthened beams was compared with that of an unstrengthened control beam. Peeling failure was the dominant mode of failure for all the strengthened beams tested. The beam strengthened with both top and bottom CFRP plates produced the highest load capacity. It was found that the longitudinal elastic shear stresses at the adhesive/concrete interface calculated at beam failure were close to the limiting value recommended in Concrete Society Technical Report 55
Chapter: Landcare on the Poverty-Protection Interface in an Asian Watershed
Serious methodological and policy hurdles constrain effective natural resource
management that alleviates poverty while protecting environmental services in tropical
watersheds. We review the development of an approach to integrate biodiversity
conservation and agroforestry development through the active involvement of
communities and their local governments near the Kitanglad Range Natural Park in the
Manupali watershed, central Mindanao, the Philippines. Agroforestry innovations were
developed to suit the biophysical and socioeconomic conditions of the buffer zone.
These included practices for tree farming, and conservation farming for annual cropping
on slopes. Institutional innovations improved resource management, resulting in an
effective social contract to protect the natural biodiversity o f the park. Fruit and timber
tree production dramatically increased, re-establishing tree cover in the buffer zone.
Natural vegetative contour strips were installed on several hundred sloping farms. Soil
erosion and runoff declined, while the buffer strips increased maize yields by an average
of 0.5 t/ha on hill-slope farms. The scientific knowledge base guided the development
and implementation of a natural resource management plan for the municipality of
Lantapan. A dynamic grassroots movement o f farmer-led Landcare groups evolved in the villages near the park boundary, which had significant impact on conservation in both the
natural and managed ecosystems. Encroachment in the natural park was reduced 95% in three
years. The local Landcare groups also restored stream corridor vegetation. This integrated
approach has been recognized as a national model for local natural resource and watershed
management in the Philippines. Currently, the collaborating institutions are evolving a negotiation
support system to resolve the interactions between the three management domains: the park,
the ancestral domain claim, and the municipalities. This integrated systems approach operated
effectively with highly constrained funding, suggesting that commitment and impact may best
be stimulated by a âdrip-feedâ approach rather than by large, externally funded efforts
Spectroscopic and Mechanistic Studies of Heterodimetallic Forms of Metallo-β-lactamase NDM-1
In an effort to characterize the roles of each metal ion in metallo-β-lactamase NDM-1, heterodimetallic analogues (CoCo-, ZnCo-, and CoCd-) of the enzyme were generated and characterized. UVâvis, 1H NMR, EPR, and EXAFS spectroscopies were used to confirm the fidelity of the metal substitutions, including the presence of a homogeneous, heterodimetallic cluster, with a single-atom bridge. This marks the first preparation of a metallo-β-lactamase selectively substituted with a paramagnetic metal ion, Co(II), either in the Zn1 (CoCd-NDM-1) or in the Zn2 site (ZnCo-NDM-1), as well as both (CoCo-NDM-1). We then used these metal-substituted forms of the enzyme to probe the reaction mechanism, using steady-state and stopped-flow kinetics, stopped-flow fluorescence, and rapid-freeze-quench EPR. Both metal sites show significant effects on the kinetic constants, and both paramagnetic variants (CoCd- and ZnCo-NDM-1) showed significant structural changes on reaction with substrate. These changes are discussed in terms of a minimal kinetic mechanism that incorporates all of the data
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Overview of mathematical approaches used to model bacterial chemotaxis I: the single cell
Mathematical modeling of bacterial chemotaxis systems has been influential and insightful in helping to understand experimental observations. We provide here a comprehensive overview of the range of mathematical approaches used for modeling, within a single bacterium, chemotactic processes caused by changes to external gradients in its environment. Specific areas of the bacterial system which have been studied and modeled are discussed in detail, including the modeling of adaptation in response to attractant gradients, the intracellular phosphorylation cascade, membrane receptor clustering, and spatial modeling of intracellular protein signal transduction. The importance of producing robust models that address adaptation, gain, and sensitivity are also discussed. This review highlights that while mathematical modeling has aided in understanding bacterial chemotaxis on the individual cell scale and guiding experimental design, no single model succeeds in robustly describing all of the basic elements of the cell. We conclude by discussing the importance of this and the future of modeling in this area
Big-Data-Driven Materials Science and its FAIR Data Infrastructure
This chapter addresses the forth paradigm of materials research -- big-data
driven materials science. Its concepts and state-of-the-art are described, and
its challenges and chances are discussed. For furthering the field, Open Data
and an all-embracing sharing, an efficient data infrastructure, and the rich
ecosystem of computer codes used in the community are of critical importance.
For shaping this forth paradigm and contributing to the development or
discovery of improved and novel materials, data must be what is now called FAIR
-- Findable, Accessible, Interoperable and Re-purposable/Re-usable. This sets
the stage for advances of methods from artificial intelligence that operate on
large data sets to find trends and patterns that cannot be obtained from
individual calculations and not even directly from high-throughput studies.
Recent progress is reviewed and demonstrated, and the chapter is concluded by a
forward-looking perspective, addressing important not yet solved challenges.Comment: submitted to the Handbook of Materials Modeling (eds. S. Yip and W.
Andreoni), Springer 2018/201
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Connectomics Analysis Reveals First-, Second-, and Third-Order Thermosensory and Hygrosensory Neurons in the Adult Drosophila Brain.
Animals exhibit innate and learned preferences for temperature and humidity-conditions critical for their survival and reproduction. Leveraging a whole-brain electron microscopy volume, we studied the adult Drosophila melanogaster circuitry associated with antennal thermo- and hygrosensory neurons. We have identified two new target glomeruli in the antennal lobe, in addition to the five known ones, and the ventroposterior projection neurons (VP PNs) that relay thermo- and hygrosensory information to higher brain centers, including the mushroom body and lateral horn, seats of learned and innate behavior. We present the first connectome of a thermo- and hygrosensory neuropil, the lateral accessory calyx (lACA), by reconstructing neurons downstream of heating- and cooling-responsive VP PNs. A few mushroom body-intrinsic neurons solely receive thermosensory input from the lACA, while most receive additional olfactory and thermo- and/or hygrosensory PN inputs. Furthermore, several classes of lACA-associated neurons form a local network with outputs to other brain neuropils, suggesting that the lACA serves as a hub for thermo- and hygrosensory circuitry. For example, DN1a neurons link thermosensory PNs in the lACA to the circadian clock via the accessory medulla. Finally, we survey strongly connected downstream partners of VP PNs across the protocerebrum; these include a descending neuron targeted by dry-responsive VP PNs, meaning that just two synapses might separate hygrosensory inputs from motor circuits. These data provide a comprehensive first- and second-order layer analysis of Drosophila thermo- and hygrosensory systems and an initial survey of third-order neurons that could directly modulate behavior.MRC LMB Graduate Studentship to M.W.P.
Boehringer Ingelheim Fonds PhD Fellowship and a Herchel Smith Studentship to A.S.B.
Cambridge Neuroscience-PSL collaborative grant supported by the Embassy of France in London to G.S.X.E.J
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