886 resultados para Difference-in-Difference
Resumo:
Approximately 250,000 measurements made for the pCO2 difference between surface water and the marine atmosphere, ΔpCO2, have been assembled for the global oceans. Observations made in the equatorial Pacific during El Nino events have been excluded from the data set. These observations are mapped on the global 4° × 5° grid for a single virtual calendar year (chosen arbitrarily to be 1990) representing a non-El Nino year. Monthly global distributions of ΔpCO2 have been constructed using an interpolation method based on a lateral advection–diffusion transport equation. The net flux of CO2 across the sea surface has been computed using ΔpCO2 distributions and CO2 gas transfer coefficients across sea surface. The annual net uptake flux of CO2 by the global oceans thus estimated ranges from 0.60 to 1.34 Gt-C⋅yr−1 depending on different formulations used for wind speed dependence on the gas transfer coefficient. These estimates are subject to an error of up to 75% resulting from the numerical interpolation method used to estimate the distribution of ΔpCO2 over the global oceans. Temperate and polar oceans of the both hemispheres are the major sinks for atmospheric CO2, whereas the equatorial oceans are the major sources for CO2. The Atlantic Ocean is the most important CO2 sink, providing about 60% of the global ocean uptake, while the Pacific Ocean is neutral because of its equatorial source flux being balanced by the sink flux of the temperate oceans. The Indian and Southern Oceans take up about 20% each.
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Representational difference analysis (RDA) was applied to isolate chromosomal markers in the rat. Four series of RDA [restriction enzymes, BamHI and HindIII; subtraction of ACI/N (ACI) amplicon from BUF/Nac (BUF) amplicon and vice versa] yielded 131 polymorphic markers; 125 of these markers were mapped to all chromosomes except for chromosome X. This was done by using a mapping panel of 105 ACI x BUF F2 rats. To complement the relative paucity of chromosomal markers in the rat, genetically directed RDA, which allows isolation of polymorphic markers in the specific chromosomal region, was performed. By changing the F2 driver-DNA allele frequency around the region, four markers were isolated from the D1Ncc1 locus. Twenty-five of 27 RDA markers were informative regarding the dot blot analysis of amplicons, hybridizing only with tester amplicons. Dot blot analysis at a high density per unit of area made it possible to process a large number of samples. Quantitative trait loci can now be mapped in the rat genome by processing a large number of samples with RDA markers and then by isolating markers close to the loci of interest by genetically directed RDA.
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Robert Kennedy's announcement of the assassination of Martin Luther King, Jr., in an Indianapolis urban community that did not revolt in riots on April 4, 1968, provides one significant example in which feelings, energy, and bodily risk resonate alongside the articulated message. The relentless focus on Kennedy's spoken words, in historical biographies and other critical research, presents a problem of isolated effect because the power really comes from elements outside the speech act. Thus, this project embraces the complexities of rhetorical effectivity, which involves such things as the unique situational context, all participants (both Kennedy and his audience) of the speech act, aesthetic argument, and the ethical implications. This version of the story embraces the many voices of the participants through first hand interviews and new oral history reports. Using evidence provided from actual participants in the 1968 Indianapolis event, this project reflects critically upon the world disclosure of the event as it emerges from those remembrances. Phenomenology provides one answer to the constitutive dilemma of rhetorical effectivity that stems from a lack of a framework that gets at questions of ethics, aesthetics, feelings, energy, etc. Thus, this work takes a pedagogical shift away from discourse (verbal/written) as the primary place to render judgments about the effects of communication interaction. With a turn to explore extra-sensory reasoning, by way of the physical, emotional, and numinous, a multi-dimensional look at public address is delivered. The rhetorician will be interested in new ways of assessing effects. The communication ethicist will appreciate the work as concepts like answerability, emotional-volitional tone, and care for the other, come to life via application and consideration of Kennedy's appearance. For argumentation scholars, the interest comes forth in a re-thinking of how we do argumentation. And the critical cultural scholar will find this story ripe with opportunities to uncover the politics of representation, racialized discourse, privilege, power, ideological hegemony, and reconciliation. Through an approach of multiple layers this real-life tale will expose the power of the presence among audience and speaker, emotive argument, as well as the magical turn of fate which all contributes the possibility of a dialogic rhetoric.
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This Article uses the example of BigLaw firms to explore the challenges that many elite organizations face in providing equal opportunity to their workers. Despite good intentions and the investment of significant resources, large law firms have been consistently unable to deliver diverse partnership structures - especially in more senior positions of power. Building on implicit and institutional bias scholarship and on successful approaches described in the organizational behavior literature, we argue that a significant barrier to systemic diversity at the law firm partnership level has been, paradoxically, the insistence on difference blindness standards that seek to evaluate each person on their individual merit. While powerful in dismantling intentional discrimination, these standards rely on an assumption that lawyers are, and have the power to act as, atomistic individuals - a dangerous assumption that has been disproven consistently by the literature establishing the continuing and powerful influence of implicit and institutional bias. Accordingly, difference blindness, which holds all lawyers accountable to seemingly neutral standards, disproportionately disadvantages diverse populations and normalizes the dominance of certain actors - here, white men - by creating the illusion that success or failure depends upon individual rather than structural constraints. In contrast, we argue that a bias awareness approach that encourages identity awareness and a relational framework is a more promising way to promote equality, equity, and inclusion.
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Non-Fourier models of heat conduction are increasingly being considered in the modeling of microscale heat transfer in engineering and biomedical heat transfer problems. The dual-phase-lagging model, incorporating time lags in the heat flux and the temperature gradient, and some of its particular cases and approximations, result in heat conduction modeling equations in the form of delayed or hyperbolic partial differential equations. In this work, the application of difference schemes for the numerical solution of lagging models of heat conduction is considered. Numerical schemes for some DPL approximations are developed, characterizing their properties of convergence and stability. Examples of numerical computations are included.
Resumo:
Different non-Fourier models of heat conduction, that incorporate time lags in the heat flux and/or the temperature gradient, have been increasingly considered in the last years to model microscale heat transfer problems in engineering. Numerical schemes to obtain approximate solutions of constant coefficients lagging models of heat conduction have already been proposed. In this work, an explicit finite difference scheme for a model with coefficients variable in time is developed, and their properties of convergence and stability are studied. Numerical computations showing examples of applications of the scheme are presented.
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Purpose: To evaluate the influence of the difference between preoperative corneal and refractive astigmatism [ocular residual astigmatism (ORA)] on outcomes obtained after laser in situ keratomileusis (LASIK) surgery for correction of myopic astigmatism using the solid-state laser technology. Methods: One hundred one consecutive eyes with myopia or myopic astigmatism of 55 patients undergoing LASIK surgery using the Pulzar Z1 solid-state laser (CustomVis Laser Pty Ltd, currently CV Laser) were included. Visual and refractive changes at 6 months postoperatively and changes in ORA and anterior corneal astigmatism and posterior corneal astigmatism (PCA) were analyzed. Results: Postoperatively, uncorrected distance visual acuity improved significantly (P < 0.01). Likewise, refractive cylinder magnitude and spherical equivalent were reduced significantly (P < 0.01). In contrast, no significant changes were observed in ORA magnitude (P = 0.81) and anterior corneal astigmatism (P = 0.12). The mean overall efficacy and safety indices were 0.96 and 1.01, respectively. These indices were not correlated with preoperative ORA (r = −0.15, P = 0.15). Furthermore, a significant correlation was found between ORA (r = 0.81, P < 0.01) and PCA postoperatively, but not preoperatively (r = 0.12, P = 0.25). Likewise, a significant correlation of ORA with manifest refraction was only found postoperatively (r = −0.38, P < 0.01). Conclusions: The magnitude of ORA does not seem to be a predictive factor of efficacy and safety of myopic LASIK using a solid-state laser platform. The higher relevance of PCA after surgery in some cases may explain the presence of unexpected astigmatic residual refractive errors.
Resumo:
Dual-phase-lagging (DPL) models constitute a family of non-Fourier models of heat conduction that allow for the presence of time lags in the heat flux and the temperature gradient. These lags may need to be considered when modeling microscale heat transfer, and thus DPL models have found application in the last years in a wide range of theoretical and technical heat transfer problems. Consequently, analytical solutions and methods for computing numerical approximations have been proposed for particular DPL models in different settings. In this work, a compact difference scheme for second order DPL models is developed, providing higher order precision than a previously proposed method. The scheme is shown to be unconditionally stable and convergent, and its accuracy is illustrated with numerical examples.
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Drawing heavily on the work of classicist Page duBois, which eloquently explains the emergence, in ancient Greece, of hierarchy and of what is still understood today as the great chain of being (scala naturae: male, female, slave, barbarian, animal), this paper analyzes the age-old negative conotations of the concept of difference in western culture, considers the reinvention of difference as “positive” by Rosi Braidotti (after Deleuze & Guattari), and reassesses the efforts of several other feminist philosophers (e.g. Luce Irigaray, Judith Butler, Gayatry Spivak, Drucilla Cornell) to counter Lacan on the impossibility of “speaking women” beyond the dominant (male) philosophical discourse. Or, to paraphrase Marie Cardinal, their efforts to find “les mots pour le dire”.
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This Commentary finds that the US-China joint declaration on climate change, issued following the Asia-Pacific Economic Cooperation (APEC) Summit in Beijing on November 12th, is undoubtedly an important announcement by the two global economic giants responsible for emitting over 30% of the world’s GHG emissions. As such, it needs to be seen as important and relevant – a very positive development towards a new global climate change agreement in Paris. It is a challenge to those that have announced their pledges and are seen as capable of doing more, as well as to those that have not yet announced their intentions. It shows the importance and success of the UN climate change conference in Warsaw last year, when the decision was made that all Parties should announce their commitments by the first quarter of 2015. It also represents a total breakdown of the Kyoto Protocol-style separation in climate change negotiations between countries into Annex 1 and non-Annex 1, with China signalling that it is taking on the leadership role that comes with being a great economic power. In broader terms, it shows that there is scope for cooperation between the two main economic actors, even in the face of competition in other spheres. It is also a challenge to the EU, which was a leader and needs to show that there is a benefit in maintaining its leadership. Finally, agreements are deemed historic only by history. This one is important, and a potential game-changer, on the face of it. But it needs to live up to its promise. There is sufficient uncertainty for us to withhold final judgement and see if its promise materialises through implementation. But, as sober a judgement as we must make on such important matters, this announcement certainly gives us great hope that it is possible to do what needs to be done, and we must wholeheartedly welcome and applaud it.
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Structured human rights dialogues are held with each of the five Central Asian republics. They are designed to discuss questions of mutual interest and enhance cooperation on human rights as well as to raise the concerns of the EU on human rights in Central Asia. In addition, the dialogues seek to involve human rights activists, NGO members, and academia representatives from both Europe and Central Asia through civil society seminars. But is this working? Is improvement in human rights noticeable in the region? This policy brief reviews and evaluates the performance of the dialogues to date, paying specific attention to the shortcomings of the existing practices, and provides recommendations for what could be improved with regard to planning and procedures.
Resumo:
After an unprecedented delay, the European Commission adopted its 2015 Enlargement Package on November 10th, together with the annual reports on each of the candidate and prospective candidate countries. In this Commentary, Erwan Fouéré offers his assessment of what Enlargement Commissioner Johannes Hahn called the “new elements” in the package, including an “overarching strategy for the next 4 years” (coinciding with the remainder of the Commission’s mandate), “much clearer guidance to the countries on what they have to focus on in the year ahead”, as well as on the “longer-term results that are needed to meet EU expectations”.
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