The Aftermath of Appreciations

This paper empirically analyzes a broad range of real exchange rate appreciation episodes. The cases are identified after compiling a large sample of monthly multilateral real exchange rates from 1960 to 1994. The objective is twofold. First, the paper studies the dynamics of appreciations, avoiding the sample selection of analyzing exclusively the crisis (or devaluation) cases. Second, the paper analyzes the mechanism by which overvaluations are corrected. In particular, we are interested in the proportion of the reversions that occur through nominal devaluations, rather than cumulative inflation differentials. We calculate the probability of undoing appreciations without nominal depreciations for various degrees of misalignment. The overall conclusion is that it is very unlikely to undo large and medium appreciations without nominal devaluations.

Liquidity crises and the international financial architecture

The paper analyzes the effect of different proposals for the new international financial architecture in an open economy liquidity crises model. It shows that an international lender of last resort that provides a complete financial rescue leads, in the short run, to a lower probability of a BoP crises and financial runs. However, the perverse incentives of a complete bailout lead to an increasing probability offinancial runs in the long run. A partial financial package may not reduce the probability of financial runs and twin crises. Private sector participation rules can increase the probability of finan- cial runs and twin crises if a large proportion of foreign investors expect to withdraw their investment without loss.

Policy Responses to Sudden Stops in Capital Flows: The Case of Chile in 1998

This chapter revisits the sudden stop in capital flows episode experienced by Chile in 1998. It documents the macroeconomic environment, the macro framework in place, and the shocks that hit it. The chapter examines the policy reaction to the shocks, evaluating its most likely consequences and analyzing key policy constraints faced at the time. Finally, it describes how the economy adjusted and compares the Chilean episode with a few other recent sudden stop cases.Sudden Stop, Chile, Capital Flows, Adjustment

IMRT QA using machine learning: A multi-institutional validation.

PurposeTo validate a machine learning approach to Virtual intensity-modulated radiation therapy (IMRT) quality assurance (QA) for accurately predicting gamma passing rates using different measurement approaches at different institutions.MethodsA Virtual IMRT QA framework was previously developed using a machine learning algorithm based on 498 IMRT plans, in which QA measurements were performed using diode-array detectors and a 3%local/3 mm with 10% threshold at Institution 1. An independent set of 139 IMRT measurements from a different institution, Institution 2, with QA data based on portal dosimetry using the same gamma index, was used to test the mathematical framework. Only pixels with ≥10% of the maximum calibrated units (CU) or dose were included in the comparison. Plans were characterized by 90 different complexity metrics. A weighted poison regression with Lasso regularization was trained to predict passing rates using the complexity metrics as input.ResultsThe methodology predicted passing rates within 3% accuracy for all composite plans measured using diode-array detectors at Institution 1, and within 3.5% for 120 of 139 plans using portal dosimetry measurements performed on a per-beam basis at Institution 2. The remaining measurements (19) had large areas of low CU, where portal dosimetry has a larger disagreement with the calculated dose and as such, the failure was expected. These beams need further modeling in the treatment planning system to correct the under-response in low-dose regions. Important features selected by Lasso to predict gamma passing rates were as follows: complete irradiated area outline (CIAO), jaw position, fraction of MLC leafs with gaps smaller than 20 or 5 mm, fraction of area receiving less than 50% of the total CU, fraction of the area receiving dose from penumbra, weighted average irregularity factor, and duty cycle.ConclusionsWe have demonstrated that Virtual IMRT QA can predict passing rates using different measurement techniques and across multiple institutions. Prediction of QA passing rates can have profound implications on the current IMRT process

An Educational Module for the Utilization of Sphenopalatine Ganglion Blocks as a Treatment Alternative for Post Dural Puncture Headache: A Quality Improvement Project

Background: Post-dural puncture headache (PDPH) is a possible adverse effect of some spinal and neuraxial anesthesia procedures; it is characterized by visual disturbances, nausea, vomiting, dizziness, photophobia, and a postural component occurring within five days of a dural puncture. The epidural blood patch (EBP) has been considered the standard treatment for PDPH; however, the EBP has a considerable number of risks due to its invasive nature. The Sphenopalatine Ganglion Block (SPGB) is a non-invasive alternative therapy that shows promise in the treatment of PDPH. Methods: A thorough search of research was performed utilizing MEDLINE (ProQuest) and CINAHL to distinguish research studies published within the past five years that have assessed the efficacy of the sphenopalatine ganglion block as a treatment for post-dural puncture headaches. Results: Five published studies were classified as appropriate for analysis. The studies evaluated sphenopalatine ganglion block as an alternative to conservative treatment for post-dural puncture headache

A simulated Northern Hemisphere terrestrial climate dataset for the past 60,000 years (vol 6, 265, 2019)

Peer reviewe

Reassessing the Value of Regional Climate Modeling Using Paleoclimate Simulations

Regional climate models (RCMs) are often assumed to be more skillful compared to lower-resolution general circulation models (GCM). However, RCMs are driven by input from coarser resolution GCMs, which may introduce biases. This study employs versions of the HadAMB3 GCM at three resolutions (>50 km) to investigate the added value of higher resolution using identically configured simulations of the preindustrial (PI), mid-Holocene, and Last Glacial Maximum. The RCM shows improved PI climatology compared to the coarse-resolution GCM and enhanced paleoanomalies in the jet stream and storm tracks. However, there is no apparent improvement when compared to proxy reconstructions. In the high-resolution GCM, accuracy in PI climate and atmospheric anomalies are enhanced despite its intermediate resolution. This indicates that synoptic and mesoscale features in a RCM are influenced by its low-resolution input, which impacts the simulated climatology. This challenges the paradigm that RCMs improve the representation of climate conditions and change.Peer reviewe