2,339 research outputs found
BEYOND THE INERTIA OF AFFLUENCE
O aquecimento global engendra perigos sem precedentes para a humanidade e é um produto de atividades humanas: a produção e o consumo de combustíveis fósseis, acompanhados de níveis cada vez maiores de gases de efeito estufa na atmosfera. Algumas das consequências previstas do aquecimento já se fazem presentes; efeitos ainda mais catastróficos serão experimentados no futuro. Dois processos comportamentais operam para manter o uso de combustíveis fósseis: 1) Estudos sobre descontos do atraso das consequências sugerem que resultados de valor relativamente menor que estão disponíveis agora (e.g., dirigir carros pessoais) são provavelmente preferidos frente ao valor de um planeta sustentável para toda a humanidade, a ser atingido em um futuro indefinido e 2) atividades atuais que envolvem o uso de combustíveis fósseis são, provavelmente, muito persistentes devido à longa e rica história de reforçamento para indivíduos (e.g., conforto e conveniência) e para a indústria de combustíveis fósseis como um todo (e.g., empregos e lucros). Uma maneira de confrontar essa persistência é taxar as emissões de gases de efeito estufa, o que pode transferir os incentivos atuais da energia baseada em combustíveis fósseis para as energias renováveis, mesmo que o abrandamento final das mudanças climáticas seja remoto. As contingências de taxação do carbono são semelhantes às empregadas para tratar o comportamento problema; descreve-se um exemplo bem-sucedido desta abordagem.Palavras-chave: aquecimento global, consumo de combustível fóssil, taxação do carbono, desvalorização pelo atraso, momento do comportamento. Global warming poses unprecedented dangers to humankind, and it is a product of human activities: Production and consumption of fossil fuels, accompanied by steadily increasing levels of greenhouse gasses in the atmosphere. Some of the predicted consequences of warming are already upon us; yet more catastrophic effects will be experienced in the future. Two behavioral processes operate to maintain fossil fuel use: 1) Delay discounting studies suggest that relatively lesser-valued outcomes (e.g., driving private cars) that are available now are likely to be preferred to the value of a sustainable planet for all humankind, to be achieved in the indefinite future; and 2) ongoing fossil-fueled activities are likely to be highly persistent because of the long and rich history of reinforcement for individuals (e.g., comfort and convenience) and for the fossil-fuel industry as a whole (e.g., jobs and profits). One way to counter that persistence is to tax greenhouse gas emissions, which can shift current incentives away from fossil-fuel based energy toward renewables, even though the ultimate slowing of climate change may be remote. Carbon-tax contingencies are similar to those employed to treat problem behavior; a successful example of this approach is described.Key words: Global warming, fossil fuel consumption, carbon tax, delay discounting, behavioral momentu
Centre for Applied Linguistics at the University of Warwick
The Centre for Applied Linguistics was established in 1983 and has grown from a relatively small teaching unit to a large centre engaged in a wide variety of activities under the broad heading of Applied Linguistics. Our work includes English language teaching, teacher education, undergraduate and postgraduate teaching in applied linguistics, development of teaching and research resources, and small- and large-scale research
An Ecological Study of the Lagoons Surrounding the John F. Kennedy Space Center, Brevard County, Florida
The studies reported here are the result of a three year effort to define the major biological, microbiological, chemical and geological characteristics of the water of the Indian River lagoon around the Kennedy Space Center and to determine the movements of those waters within and between the various basins. This work was the result of a jointly funded agreement between the Florida Institute of Technology and John F. Kennedy Space Center, NASA under NASA Grant NGR 10-015-008, dated April 11, 1972. This cost sharing grant was renewed for each of two successive years. Sampling operations were terminated August 31, 1975
Behavioral Momentum Theory: Equations and Applications
Behavioral momentum theory provides a quantitative account of how reinforcers experienced within a discriminative stimulus context govern the persistence of behavior that occurs in that context. The theory suggests that all reinforcers obtained in the presence of a discriminative stimulus increase resistance to change, regardless of whether those reinforcers are contingent on the target behavior, are noncontingent, or are even contingent on an alternative behavior. In this paper, we describe the equations that constitute the theory and address their application to issues of particular importance in applied settings. The theory provides a framework within which to consider the effects of interventions such as extinction, noncontingent reinforcement, differential reinforcement of alternative behavior, and other phenomena (e.g., resurgence). Finally, the theory predicts some counterintuitive and potentially counterproductive effects of alternative reinforcement, and can serve as an integrative guide for intervention when its terms are identified with the relevant conditions of applied settings
Subacute Stroke in Young Hispanic Male With Vertebrobasilar Dolichoectasia
Background: Vertebrobasilar dolichoectasia (VBD) is a rare clinical entity characterized by dilatation, elongation, and tortuosity of the vertebrobasilar arteries. Patients with VBD can present varying symptoms from ischemia, compression of blood vessels, or rarely subarachnoid hemorrhage.
Case presentation: A 29-year-old Hispanic man with history of hypertension presented to emergency department with progressive left upper extremity weakness, dizziness, slurry speech, and diplopia of one-week duration. On arrival, the patient was afebrile, heart rate 75 bpm and blood pressure 193/107 mmHg. He was alert and oriented x3. Neurological exam demonstrated decreased strength (4/5) on left upper extremity and left arm pronator drift. In addition, the right eye had partial ptosis and appeared laterally deviated with weak adduction and elevation, consistent with right cranial nerve III palsy. The patient was admitted for further workup ischemic brainstem stroke in a young adult. CT Brain was negative for hemorrhage but revealed vertebrobasilar dolichoectasia. MRI confirmed an area of ischemic stroke in the right medial midbrain at the level of cerebral peduncles involving the oculomotor nucleus. He was conservatively managed for stroke. He is scheduled to follow up with interventional neurology for definitive treatment.
Conclusion: Vertebrobasilar dolichoectasia is a rare condition with a prevalence of less than 2% of the population. There is an association with male sex, older age, and hypertension. Currently, there are no guidelines on effective and specific treatments for VBD, which causes life-threatening complications. However, surgical and endovascular approaches are presently being performed
Carbon Detonation and Shock-Triggered Helium Burning in Neutron Star Superbursts
The strong degeneracy of the 12C ignition layer on an accreting neutron star
results in a hydrodynamic thermonuclear runaway, in which the nuclear heating
time becomes shorter than the local dynamical time. We model the resulting
combustion wave during these superbursts as an upward propagating detonation.
We solve the reactive fluid flow and show that the detonation propagates
through the deepest layers of fuel and drives a shock wave that steepens as it
travels upward into lower density material. The shock is sufficiently strong
upon reaching the freshly accreted H/He layer that it triggers unstable 4He
burning if the superburst occurs during the latter half of the regular Type I
bursting cycle; this is likely the origin of the bright Type I precursor bursts
observed at the onset of superbursts. The cooling of the outermost shock-heated
layers produces a bright, ~0.1s, flash that precedes the Type I burst by a few
seconds; this may be the origin of the spike seen at the burst onset in 4U
1820-30 and 4U 1636-54, the only two bursts observed with RXTE at high time
resolution. The dominant products of the 12C detonation are 28Si, 32S, and
36Ar. Gupta et al. showed that a crust composed of such intermediate mass
elements has a larger heat flux than one composed of iron-peak elements and
helps bring the superburst ignition depth into better agreement with values
inferred from observations.Comment: 11 pages, 11 figures, accepted to ApJ; discussion about onset of
detonation discussed in new detail, including a new figur
Studies On The Lagoons Of East Centeral Florida
Detailed examination of the water quality parameters of the lagoons of East Central Florida were begun in 1969. This investigation was subsequently expanded to include other aspects of these waters. General trends and a statistical model are beginning to emerge for the water quality parameters. Man-made and natural effects have resulted in substantial alteration of water parameters since the study was initiated
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