16,464 research outputs found
Preparations for Independence and Financial Security in Later Life: A Conceptual Framework and Application to Canada
In this paper, we develop a conceptual framework to describe an individual's preparations for later life. Situated in the life course perspective, this provides a framework that invites a more comprehensive and systematic study of preparations for later life. It describes a dynamic process that portrays the interplay between social structure and human agency. Through its consideration of collective preparations (the public protection programs offered by the state), individual preparations (financial and non- financial), and the interplay between the two, this framework provides fresh insight into the existing literature on retirement planning, the timing of retirement, savings, and consumption behaviour in later life. Moreover, the model may be used to structure research questions, to guide policy decision making and to point the direction for the design and content of future research studies. While the purpose of this paper is primarily the development of a conceptual model, we draw on empirical examples from the 1991 Survey of Aging and Independence (SAI) to illustrate some aspects of the model to Canada. We conclude by suggesting a number of research and questions that may be generated from the model.retirement planning; savings; SAI
On the Impact of Fair Best Response Dynamics
In this work we completely characterize how the frequency with which each
player participates in the game dynamics affects the possibility of reaching
efficient states, i.e., states with an approximation ratio within a constant
factor from the price of anarchy, within a polynomially bounded number of best
responses. We focus on the well known class of congestion games and we show
that, if each player is allowed to play at least once and at most times
any best responses, states with approximation ratio times the
price of anarchy are reached after best
responses, and that such a bound is essentially tight also after exponentially
many ones. One important consequence of our result is that the fairness among
players is a necessary and sufficient condition for guaranteeing a fast
convergence to efficient states. This answers the important question of the
maximum order of needed to fast obtain efficient states, left open by
[9,10] and [3], in which fast convergence for constant and very slow
convergence for have been shown, respectively. Finally, we show
that the structure of the game implicitly affects its performances. In
particular, we show that in the symmetric setting, in which all players share
the same set of strategies, the game always converges to an efficient state
after a polynomial number of best responses, regardless of the frequency each
player moves with
Evaluating Unpaid Time Contributions by Seniors: A Conceptual Framework
In the past, considerable research in gerontology has focused on services provided to seniors. Recently, however, there has a been a growing recognition of the contributions made by seniors to their families, communities and to society. Empirical estimates have been provided by researchers to show how much these contributions are worth in terms of savings in dollar amounts. A critical review of the literature identifies unresolved issues concerning which contributions to count and how to measure and value these contributions. As yet, no clear criteria exist that readily identify the distinction between volunteer activities and unpaid work, what specifically should be counted as an unpaid time contribution, how it should be quantified, and how this unit of contribution should be monetarily valued. The market replacement approach and the opportunity cost approach that are used to assign value to unpaid work often use very different wage rates or levels of income loss. This paper reviews the relevant literature and identifies important issues in evaluating unpaid time contribution of seniors. The authors propose a framework which addresses some of the methodological shortcomings identified in previous research and which provides a guide for future research in this area.seniors; valuing unpaid work
La liberaciĂłn inmediata de buques en procedimientos de medidas provisionales. ÂżNuevas tendencias y desafĂos?
This article discusses the incidents and situations created when vessels are detained in foreign ports, and the measures that need to be undertaken to overcome these disputes, analyzing the United Nations Convention on the Law of the Sea; that not only provides a frame that all States (who have submitted) should constrain to, but also contributes to define the peaceful means for settlements intended to overcome such controversial situations. Apart from the consideration of all these regulations, jurisprudence and real precedents are explored. In first place, to perceive the way parties react towards these situations, and also to understand how the settlement of disputes be operationalized through the International Tribunal for the Law of the Sea. For this purpose, contemporary cases such as the Grand Prince, the ARA Libertad, and the Artic Sunrise are deepened.En el presente artĂculo se ven plasmados los incidentes que pueden presentarse cuando los buques y sus tripulaciones son detenidos en puertos extranjeros, y las distintas medidas a tomar ante estas controversias, analizando la ConvenciĂłn de las Naciones Unidas sobre el Derecho del Mar, que no solo provee una regulaciĂłn marco a la que todos los Estados signatarios deben adecuarse, sino que tambiĂŠn contribuye con la enunciaciĂłn de las distintas formas de soluciĂłn pacĂfica creadas para superar estas situaciones.
AdemĂĄs de considerar estas regulaciones, es necesario analizar la jurisprudencia al respecto. En primer lugar, ya que ayuda a visualizar la forma en que los Estados actĂşan frente a estas situaciones y asimismo para comprender cĂłmo el sistema de soluciĂłn de controversias ha sido llevado a la prĂĄctica por el Tribunal de Hamburgo. Con esa finalidad profundizamos sobre algunos casos contemporĂĄneos como el Grand Prince, el ARA Libertad y el Artic Sunrise
Over-expressing the C3 photosynthesis cycle enzyme Sedoheptulose-1-7 Bisphosphatase improves photosynthetic carbon gain and yield under fully open air CO2fumigation (FACE)
Abstract
Background
Biochemical models predict that photosynthesis in C3 plants is most frequently limited by the slower of two processes, the maximum capacity of the enzyme Rubisco to carboxylate RuBP (Vc,max), or the regeneration of RuBP via electron transport (J). At current atmospheric [CO2] levels Rubisco is not saturated; consequently, elevating [CO2] increases the velocity of carboxylation and inhibits the competing oxygenation reaction which is also catalyzed by Rubisco. In the future, leaf photosynthesis (A) should be increasingly limited by RuBP regeneration, as [CO2] is predicted to exceed 550 ppm by 2050. The C3 cycle enzyme sedoheptulose-1,7 bisphosphatase (SBPase, EC 3.1.3.17) has been shown to exert strong metabolic control over RuBP regeneration at light saturation.
Results
We tested the hypothesis that tobacco transformed to overexpressing SBPase will exhibit greater stimulation of A than wild type (WT) tobacco when grown under field conditions at elevated [CO2] (585 ppm) under fully open air fumigation. Growth under elevated [CO2] stimulated instantaneous A and the diurnal photosynthetic integral (A') more in transformants than WT. There was evidence of photosynthetic acclimation to elevated [CO2] via downregulation of Vc,max in both WT and transformants. Nevertheless, greater carbon assimilation and electron transport rates (J and Jmax) for transformants led to greater yield increases than WT at elevated [CO2] compared to ambient grown plants.
Conclusion
These results provide proof of concept that increasing content and activity of a single photosynthesis enzyme can enhance carbon assimilation and yield of C3 crops grown at [CO2] expected by the middle of the 21st century.
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Air hydrodynamics of the ultrafast laser-triggered spark gap
We present space and time resolved measurements of the air hydrodynamics
induced by ultrafast laser pulse excitation of the air gap between two
electrodes at high potential difference. We explore both plasma-based and
plasma-free gap excitation. The former uses the plasma left in the wake of
femtosecond filamentation, while the latter exploits air heating by
multiple-pulse resonant excitation of quantum molecular wavepackets. We find
that the cumulative electrode-driven air density depression channel initiated
by the laser plays the dominant role in the gap evolution leading to breakdown
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Crystal structure of 1-bis(((1R,2S,5R)-2-isopropyl-5-methylcyclohexyl) cyclopentadienyl)-1-trimethylphosphine-2,3-bis(trimethylsilyl) -1-hafnacycloprop-2-ene-hexane (1:0.5), (HfC8H18Si 2)(C15H22)2(PC3H 9) ¡ 0.5C6H14
C44H78HfPSi2, tetragonal, P4 1212 (no. 92), a = 14.9634(2) Ă
, c = 44.9270(8) Ă
, V = 10059.3 Ă
3, Z = 8, Rgt(F) = 0.026, wRref(F2) = 0.073, T = 200 K. Š by Oldenbourg Wissenschaftsverlag, Mßnchen
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