854 resultados para Difficult times


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It is well accepted that people resist evidence that contradicts their beliefs.Moreover, despite their training, many scientists reject results that are inconsistent withtheir theories. This phenomenon is discussed in relation to the field of judgment anddecision making by describing four case studies. These concern findings that clinical judgment is less predictive than actuarial models; simple methods have proven superiorto more theoretically correct methods in times series forecasting; equal weighting ofvariables is often more accurate than using differential weights; and decisions cansometimes be improved by discarding relevant information. All findings relate to theapparently difficult-to-accept idea that simple models can predict complex phenomenabetter than complex ones. It is true that there is a scientific market place for ideas.However, like its economic counterpart, it is subject to inefficiencies (e.g., thinness,asymmetric information, and speculative bubbles). Unfortunately, the market is only correct in the long-run. The road to enlightenment is bumpy.

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Plutonium and (90)Sr are considered to be among the most radiotoxic nuclides produced by the nuclear fission process. In spite of numerous studies on mammals and humans there is still no general agreement on the retention half time of both radionuclides in the skeleton in the general population. Here we determined plutonium and (90)Sr in human vertebrae in individuals deceased between 1960 and 2004 in Switzerland. Plutonium was measured by sensitive SF-ICP-MS techniques and (90)Sr by radiometric methods. We compared our results to the ones obtained for other environmental compartments to reveal the retention half time of NBT fallout (239)Pu and (90)Sr in trabecular bones of the Swiss population. Results show that plutonium has a retention half time of 40+/-14 years. In contrast (90)Sr has a shorter retention half time of 13.5+/-1.0 years. Moreover (90)Sr retention half time in vertebrae is shown to be linked to the retention half time in food and other environmental compartments. These findings demonstrate that the renewal of the vertebrae through calcium homeostatic control is faster for (90)Sr excretion than for plutonium excretion. The precise determination of the retention half time of plutonium in the skeleton will improve the biokinetic model of plutonium metabolism in humans.

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We address the problem of scheduling a multi-station multiclassqueueing network (MQNET) with server changeover times to minimizesteady-state mean job holding costs. We present new lower boundson the best achievable cost that emerge as the values ofmathematical programming problems (linear, semidefinite, andconvex) over relaxed formulations of the system's achievableperformance region. The constraints on achievable performancedefining these formulations are obtained by formulatingsystem's equilibrium relations. Our contributions include: (1) aflow conservation interpretation and closed formulae for theconstraints previously derived by the potential function method;(2) new work decomposition laws for MQNETs; (3) new constraints(linear, convex, and semidefinite) on the performance region offirst and second moments of queue lengths for MQNETs; (4) a fastbound for a MQNET with N customer classes computed in N steps; (5)two heuristic scheduling policies: a priority-index policy, anda policy extracted from the solution of a linear programmingrelaxation.

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Thank you for inviting me again this year to talk with you about the condition of Iowa’s judicial branch. As your partner in government, we look forward to working with you on issues affecting the administration of justice. If I could capture the condition of our courts, indeed the condition of our state, in a few words, it would be: “We live in challenging times.” No one knows the true meaning of this phrase better than those Iowans hit by natural disasters. But my focus today is, of course, on the courts. Ensuring the delivery of equal, affordable and accessible justice is always challenging work, but it will be especially so this year and the next in light of the State’s budget problems. Given the magnitude of this challenge, it is even more imperative that we work together in the spirit of unity, candor and cooperation. And I address you today in this spirit. We are deeply concerned, as you are, about the present financial situation and its effect on individual Iowans. Naturally, we are particularly troubled about its impact on the delivery of justice to our citizens. Even in good economic times, the administration of justice is difficult to fulfill given the sheer volume and complexity of problems Iowans bring to their courthouses. Because of the effects of the nation’s economic downturn, people will need access to justice now more than ever. We already see this happening. The number of mortgage foreclosure cases in Iowa rose 14% in the past year. Debt collection cases increased 20% in the same time. An increase in these types of cases is predictable in tough economic times, but other types of problems may escalate as well. Some experts fear that a recession may also give rise to more crime, child abuse, domestic violence, and substance abuse. Naturally, for the sake of the people who may be harmed by these problems, we hope they do not occur. If they do, however, these matters will demand our immediate attention.

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Newsletter produced by Deaf Services Commission of Iowa

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Newsletter produced by Deaf Services Commission of Iowa

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Newsletter produced by Deaf Services Commission of Iowa

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Newsletter produced by Deaf Services Commission of Iowa

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Newsletter produced by Deaf Services Commission of Iowa

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Newsletter produced by Deaf Services Commission of Iowa

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Newsletter produced by Deaf Services Commission of Iowa

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Newsletter produced by Deaf Services Commission of Iowa

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Newsletter produced by Deaf Services Commission of Iowa