1,109 research outputs found
A new educational perspective for teaching gravity
Today's method of teaching the concept of falling bodies in French physics classes is ineffective, not only because it ignores the physical aspect of the phenomenon by addressing only its mathematical aspect, but also because it does not take into account students' conceptions. The goal of the present study was to assess the effectiveness of a new educational perspective for teaching gravity, based on an analogical presentation of Einstein's theory of the deformation of space-time. The conceptions of French ninth graders and how they evolve are analyzed and compared for two different teaching methods, the new perspective (n = 102) and an approach based on Newton's theory of bodies interacting at a distance. The data obtained are used to describe students' initial conceptions of falling bodies, and confirm the lesser effectiveness of the teaching approach based on Newton's theory. The results provide evidence of two phases of conceptual change: "positive substitution" (when a correct explanatory system replaces an erroneous one) and "generalization" (when the domain of validity of a correct explanatory system is extended). They also show that Einstein's theory can be understood by ninth graders and promotes more conceptual change than a method based on Newton's theory. The new perspective appears to help students not only to extend the domain of validity of the correct conception - that bodies fall because they are attracted - but also to change their conception of attraction, now understood as the effect of a property of space rather than a property of bodies
Procédure de sélection pour les contrats de Génie Civil
L'exposé débute par le rappel de quelques caractéristiques du projet LHC, Génie Civil. La procédure de sélection est ensuite décrite aux deux niveaux auxquels elle a été appliquée successivement : le choix des consultants, puis celui des entreprises. Par un découpage géographique approprié, le projet a été divisé en trois lots d'études et quatre lots de travaux. Ceux-ci ont tous fait l'objet de cette procédure nouvelle au CERN. Les avantages et inconvénients nés de l'application de cette procédure sont succinctement décrits. Il est particulièrement insisté, à ce titre, sur la transparence, la compatibilité avec les règles d'achat du CERN, et l'obtention, en final, de choix plus fiables que précédemment. Enfin, quelques considérations sont données sur les possibilités d'élargissement à d'autres spécialités que le génie civil. Par ailleurs, les tendances pour le futur en matière de procédures d'appels d'offres de grands travaux, sont également dégagées
Balancing Interests in Forest Governance in Brazil and Indonesia
Forests play a major role in reducing levels of Greenhouse gasses which are a major contributor to global warming. Conversely, deforestation is a major contributor to climate change. This study examines the concept of good forest governance, dispelling notions that resource use needs to be a zero-sum game. Rather, it identifies local collective agreements as espoused by Elinor Ostrom in Governing the Commons as the best means of balancing the undeniable economic potential of converting forests to other uses (grazing, farming, and mining) with the more sustainable approach of protecting forests for their environmental benefit. For Ostrom, these collective agreements are the most promising approach to achieving good governance which protects forests, reduces deforestation, and creates a sustainable balance between economic growth and forest preservation. Despite a major focus of states, international organizations, NGOs, and foreign aid donors, improving forest governance has proven to be a challenge. Using efforts in Brazil and Indonesia to implement forest governance, this study uses the PEAT (Participation, capacity for Enforcement, Accountability, and Transparency) framework to evaluate the role of state actors, non-governmental organizations, agribusiness, and Indigenous people and local communities in forest governance. By presenting a structured comparison of forest governance in these two countries, the thesis seeks to highlight successful efforts to improve forest governance, identify persistent obstacles, and extract lessons from each case that can be applied to improve forest governance elsewhere
COVID-19: The Impact of a Nation’s Political Economic Structure on its Labor Market Spending Policies
The onslaught of COVID-19 in March 2020 claimed the lives of millions and caused a global economic downturn marked by vast unemployment. Previous research has focused on how fiscal policy is utilized by advanced developed nations and their objectives with respect to fiscal policy. This paper aims to examine how a given nation’s labor market spending policies are impacted by its political economic structure. In order to delineate between and analyze the approaches of different political economic structures, this paper utilizes Nordic, Liberal, and Asian States constructs. In order to investigate the impact of political economic structure on labor market spending, explanatory variables, including GDP growth rate, the unemployment rate, top marginal individual income tax rates, the GINI index, a democracy index, and COVID-19 confirmed cases, will be utilized in a regression analysis to examine the effects on the unemployment benefits replacement rate. A nation’s top marginal individual income tax rate is found to have a significant positive effect on a nation’s unemployment benefits replacement rate. And of the three constructs (Nordic, Liberal, and Asian states), Liberal is the only significant result, and had a strong negative correlation with a nation’s unemployment benefits replacement rate. Moving forward, this has broad implications for Liberal states. Particularly in the U.S., the COVID-19 pandemic has exposed disparities in the labor market for low-income workers. This may prove to be a turning point as policy makers accede to demands for more support to workers in the form of enhanced unemployment benefits
What Does it Mean to Decolonize the Curriculum?
Join Dr. Cutcha Risling Baldy, department chair of Native American Studies at Cal Poly and author of we are dancing for you: Native Feminisms & the Revitalization of Women’s Coming-of-Age Ceremonies for an introduction to decolonizing the curriculum
Food Democracy from the Top Down? State-Driven Participation Processes for Local Food System Transformations towards Sustainability
Food democracy is a concept with growing influence in food policy research. It involves citizens regaining democratic control of the food system and enabling its sustainable transformation. In focusing mainly on civil society initiatives, food democracy research has so far neglected the potential of state-driven food-related participation processes. We base our study on qualitative interviews with local stakeholders in two smaller cities in southern Germany where the city administration and city council initiated participatory processes. The study aims to understand how local actors are framing state-driven participation processes concerning sustainable local food system transformation along key dimensions of food democracy. We identify eight categories that conceptually constitute food democracy: mutual knowledge exchange; legitimacy and credibility of knowledge claims; transparent processes for deliberating ideas; shared language for sharing ideas; expectations of and experience with efficacy; role model function of municipalities; raising awareness; and motivation and justification of the normative orientation. Furthermore, the empirical analysis shows that state actors can have important roles in food-related participation processes as potential initiators, shapers and implementers depending on how they interact with local food-related actors and how they design and coordinate food system transformation processes. This suggests that food democracy research should not necessarily conceptualize state actors, local entrepreneurs and citizens as opponents, but rather, should reconsider how these various actors can drive food democracy and citizenship in a supportive and coordinated way
Leaf color and vine size are related to yield in a phylloxera-infested vineyard
The uneven spread of phylloxera infestation and associated vine symptoms in vineyards usually complicates yield estimates and vineyard replacement decisions. In a Cabernet Sauvignon vineyard with AXR#1 rootstock the current season's and following season's yields of 40 vine plots correlated (r ≥ 0.77, p ≤ 0.05) with early to midseason leaf and canopy spectra measured in the field, laboratory and remotely with aircraft-borne sensors
Occupancy and landscape use of medium and large mammals in a large Atlantic Forest remnant
Orientadores: Eleonore Zulnara Freire Setz, Adriano Garcia ChiarelloTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: MĂ©dios e grandes mamĂferos exercem importantes funções ecolĂłgicas para a manutenção e equilĂbrio dos ecossistemas. No entanto, diversos impactos humanos tem ameaçado globalmente a mastofauna. Portanto, para que a conservação desse grupo e suas funções ecolĂłgicas seja efetiva, Ă© necessário estabelecer qual a sua relação com as caracterĂsticas da paisagem e as diferentes categorias de proteção da área. Dessa forma, buscamos definir os principais fatores que influenciam o uso da paisagem e a ocupação de dois grupos-chave de mĂ©dios e grandes mamĂferos (frugĂvoros e predadores), bem como avaliar a influĂŞncia de diferentes categorias de proteção na efetividade em se conservar funções ecolĂłgicas de mamĂferos. Amostramos 45 sĂtios em um remanescente grande de Mata Atlântica utilizando armadilhamento fotográfico e testes de playback e aplicamos um mĂ©todo de detecção/nĂŁo-detecção para estimar a ocupação dos mamĂferos e o grau de suas funções ecolĂłgicas. Fatores antrĂłpicos, como densidade de estradas e distância da área de maior grau de proteção foram os principais determinantes da ocupação de frugĂvoros e do uso do habitat por felĂdeos. Ainda, áreas com maior grau de proteção apresentaram mais funções ecolĂłgicas de mamĂferos do que áreas com menor grau, essas ainda que protegidas. Esses resultados indicam a sensibilidade de grupos-chave de mamĂferos Ă pressões antrĂłpicas mesmo em áreas mais conservadas e protegidas, e reiteram a importância de se ter áreas de alto grau de proteção para a conservação efetiva de mamĂferos e suas funções ecolĂłgicasAbstract: Medium and large mammals exert important ecological functions on ecosystem maintenance and balance. However, several human impacts are global threats to mammals. Therefore, in order to effectively conserve this group and its ecological functions, it is necessary to establish its relation with landscape characteristics and with different protection status. We aimed to determine the main factors driving the occupancy and landscape use of two key groups of medium and large mammals (frugivores and predators), as well as to evaluate the influence of different protection status in conserving mammal ecological functions. We sampled 45 sites in a large Atlantic Forest remnant and applied a detection/non-detection sampling method using camera trap and call survey data to estimate mammal occupancy and measure the degree of their ecological functions. Anthropogenic factors, such as road density and distance to a more protected area, were the main determinants of the occupancy and habitat use of frugivores and felids. Moreover, areas with higher protection status showed more mammal ecological functions than less protected areas, even those being protected. These results indicate that key mammal groups are sensitive to anthropogenic pressures even in conserved and protected areas, and highlight the importance of maintaining and creating high protection areas to effectively conserve mammals and their ecological functionsDoutoradoEcologiaDoutora em EcologiaCAPE
Etude des variations de la de la teneur en eau du sol en fonction du couvert végétal en Tunisie du Nord
- …