Mesoscopic interference

We analyze a double-slit experiment when the interfering particle is "mesoscopic" and one endeavors to obtain Welcher Weg information by shining light on it. We derive a compact expression for the visibility of the interference pattern: coherence depends on both the spatial and temporal features of the wave function during its travel to the screen. We set a bound on the temperature of the mesoscopic particle in order that its quantum mechanical coherence be maintained.Comment: 16 pages, 14 figure

Wigner function and coherence properties of cold and thermal neutrons

We analyze the coherence properties of a cold or a thermal neutron by utilizing the Wigner quasidistribution function. We look in particular at a recent experiment performed by Badurek {\em et al.}, in which a polarized neutron crosses a magnetic field that is orthogonal to its spin, producing highly non-classical states. The quantal coherence is extremely sensitive to the field fluctuation at high neutron momenta. A "decoherence parameter" is introduced in order to get quantitative estimates of the losses of coherence.Comment: 6 pages, 3 figures. Contribution to the Sixth Central-European Workshop on Quantum Optics, Chudobin near Olomouc, Czech Republic, April-May 199

Decoherence vs entropy in neutron interferometry

We analyze the coherence properties of polarized neutrons, after they have interacted with a magnetic field or a phase shifter undergoing different kinds of statistical fluctuations. We endeavor to probe the degree of disorder of the distribution of the phase shifts by means of the loss of quantum mechanical coherence of the neutron. We find that the notion of entropy of the shifts and that of decoherence of the neutron do not necessarily agree. In some cases the neutron wave function is more coherent, even though it has interacted with a more disordered medium.Comment: 13 pages, 5 figure

Designing the ideal perioperative pain management plan starts with multimodal analgesia.

Multimodal analgesia is defined as the use of more than one pharmacological class of analgesic medication targeting different receptors along the pain pathway with the goal of improving analgesia while reducing individual class-related side effects. Evidence today supports the routine use of multimodal analgesia in the perioperative period to eliminate the over-reliance on opioids for pain control and to reduce opioid-related adverse events. A multimodal analgesic protocol should be surgery-specific, functioning more like a checklist than a recipe, with options to tailor to the individual patient. Elements of this protocol may include opioids, non-opioid systemic analgesics like acetaminophen, non-steroidal anti-inflammatory drugs, gabapentinoids, ketamine, and local anesthetics administered by infiltration, regional block, or the intravenous route. While implementation of multimodal analgesic protocols perioperatively is recommended as an intervention to decrease the prevalence of long-term opioid use following surgery, the concurrent crisis of drug shortages presents an additional challenge. Anesthesiologists and acute pain medicine specialists will need to advocate locally and nationally to ensure a steady supply of analgesic medications and in-class alternatives for their patients\u27 perioperative pain management

Constructing a Coincident Index of Business Cycles without Assuming a One-factor Model

The Stock–Watson coincident index and its subsequent extensions assume a static linear one-factor structure for the component indicators. Such assumption is restrictive in practice, however, with as few as four indicators. In fact, such assumption is unnecessary if one defines a coincident index as an estimate of latent monthly real GDP. This paper considers VAR and factor models for latent monthly real GDP and other coincident indicators, and estimates the models using the observable mixed-frequency series. For US data, Schwartz’s Bayesian information criterion selects a two-factor model. The smoothed estimate of latent monthly real GDP is the proposed index.

External Debt, Adjustment, and Growth

High ratios of external debt to GDP in selected Asian countries have contributed to the initiation, propagation, and severity of the financial and economic crises in recent years, reflecting runaway fiscal deficits and excessive foreign borrowing by the private sector. More importantly, the servicing of large debt stocks has diverted scarce resources from investment and long-term growth. Applying and calibrating the formal framework proposed by Villanueva (2003) to Philippine data, we explore the joint dynamics of external debt, capital accumulation, and growth. The relative simplicity of the model makes it convenient to analyze the links between domestic adjustment policies, foreign borrowing, and growth. We estimate the optimal domestic saving rate that is consistent with maximum real consumption per unit of effective labor in the long run. As a by-product, we estimate the steady-state ratio of net external debt to GDP that is associated with this optimal outcome. The framework is an extension of the standard neoclassical growth model that incorporates endogenous technical change and global capital markets. The major policy implications are that in the long run, fiscal adjustment and the promotion of private saving are critical; reliance on foreign saving in a globalized financial world has limits; and when risk spreads are highly and positively correlated with rising external debt levels, unabated foreign borrowing depresses long run welfare.

Sustainable External Debt Levels: Estimates for Selected Asian Countries

High ratios of external debt to GDP in selected Asian countries have contributed to the initiation, propagation, and severity of the financial and economic crises in recent years, reflecting runaway fiscal deficits and excessive foreign borrowing by the private sector. Applying the formal framework proposed by Villanueva (2003) to a selected group of Asian countries, the research estimates the external debt thresholds beyond which further debt accumulation will have negative effects on growth and will become unsustainable. The framework is an extension of the standard neoclassical growth model that incorporates global capital markets. ‘Sustainability’ is measured in terms of the steady-state ratio of the stock of external debt to GDP, as functions of real world interest rates, risk spreads and their responsiveness to external debt burdens and market perceptions of country risk, marginal propensities to save out of national disposable income and foreign borrowing, rates of technical change, and parameters of the production function. The major policy implications are that in the long run, fiscal consolidation and the promotion of private saving are critical, and that reliance on foreign saving in a globalized financial world has limits, particularly when the risk spreads are positively correlated with rising external debt levels.