Some Further Evidence on Exchange-Rate Volatility and Exports

The relationship between exchange-rate volatility and aggregate export volumes for 12 industrial economies is examined using a model that includes real export earnings of oil-producing economies as a determinant of industrial-country export volumes. A supposition underlying the model is that, given their levels of economic development, oil-exporters’ income elasticities of demand for industrial-country exports might differ from those of industrial countries. Five estimation techniques, including a generalized method of moments (GMM) and random coefficient (RC) estimation, are employed on panel data covering the estimation period 1977:1-2003:4 using three measures of volatility. In contrast to recent studies employing panel data, we do not find a single instance in which volatility has a negative and significant impact on trade.Exchange-rate volatility; Trade; Random-coefficient estimation; Generalized method of moments; Panel

Unified concurrent write barrier

In a programming language with support for garbage collection, a write barrier is a code snippet that maintains the key invariants of the garbage collector. The write barrier is typically executed after a write operation. The write barrier is computationally expensive and can impact program performance. This is true to a greater extent for languages where garbage collectors need to maintain multiple sets of invariants. For example, languages that employ garbage collection schemes with two collectors may maintain their invariants using multiple different write barriers. The techniques of this disclosure address the problem of maintaining multiple invariants by unifying the write barriers and by executing computationally expensive parts of the write barrier in a concurrent thread

U.S. official forecasts of Group of Seven economic performance, 1976-90

In this paper, we evaluate the accuracy of the U.S. Treasury Department forecasts of real growth and inflation from 1976 to 1990 for the Group of Seven (G-7) economies. The accuracy of these forecasts is measured against the standard of actual real world growth and inflation as subsequently published in the Treasury's World Economic Outlook (WEO). The primary comparison is to forecasts made by the OECD for each of the G-7 nations, but for the United States and Canada, we compare the forecasts to those made by the Blue Chip consensus and the Federal Reserve 'Greenbook'.Group of Seven countries ; Inflation (Finance)

Visuomotor performance at high altitude in COPD patients. Randomized placebo-controlled trial of acetazolamide

Introduction: We evaluated whether exposure to high altitude impairs visuomotor learning in lowlanders with chronic obstructive pulmonary disease (COPD) and whether this can be prevented by acetazolamide treatment.Methods: 45 patients with COPD, living <800 m, FEV1 ≥40 to <80%predicted, were randomized to acetazolamide (375 mg/d) or placebo, administered 24h before and during a 2-day stay in a clinic at 3100 m. Visuomotor performance was evaluated with a validated, computer-assisted test (Motor-Task-Manager) at 760 m above sea level (baseline, before starting the study drug), within 4h after arrival at 3100 m and in the morning after one night at 3100 m. Main outcome was the directional error (DE) of cursor movements controlled by the participant via mouse on a computer screen during a target tracking task. Effects of high altitude and acetazolamide on DE during an adaptation phase, immediate recall and post-sleep recall were evaluated by regression analyses. www.ClinicalTrials.gov NCT03165890.Results: In 22 patients receiving placebo, DE at 3100 m increased during adaptation by mean 2.5°, 95%CI 2.2° to 2.7° (p < 0.001), during immediate recall by 5.3°, 4.6° to 6.1° (p < 0.001), and post-sleep recall by 5.8°, 5.0 to 6.7° (p < 0.001), vs. corresponding values at 760 m. In 23 participants receiving acetazolamide, corresponding DE were reduced by −0.3° (−0.6° to 0.1°, p = 0.120), −2.7° (−3.7° to −1.6°, p < 0.001) and −3.1° (−4.3° to −2.0°, p < 0.001), compared to placebo at 3100 m.Conclusion: Lowlanders with COPD travelling to 3100 m experienced altitude-induced impairments in immediate and post-sleep recall of a visuomotor task. Preventive acetazolamide treatment mitigated these undesirable effects

Acetazolamide to Prevent Adverse Altitude Effects in COPD and Healthy Adults

Background We evaluated the efficacy of acetazolamide in preventing adverse altitude effects in patients with moderate to severe chronic obstructive pulmonary disease (COPD) and in healthy lowlanders 40 years of age or older. Methods Trial 1 was a randomized, double-blind, parallel-design trial in which 176 patients with COPD were treated with acetazolamide capsules (375 mg/day) or placebo, starting 24 hours before staying for 2 days at 3100 m. The mean (±SD) age of participants was 57±9 years, and 34% were women. At 760 m, COPD patients had oxygen saturation measured by pulse oximetry of 92% or greater, arterial partial pressure of carbon dioxide less than 45 mm Hg, and mean forced expiratory volume in 1 second of 63±11% of predicted. The primary outcome in trial 1 was the incidence of the composite end point of altitude-related adverse health effects (ARAHE) at 3100 m. Criteria for ARAHE included acute mountain sickness (AMS) and symptoms or findings relevant to well-being and safety, such as severe hypoxemia, requiring intervention. Trial 2 comprised 345 healthy lowlanders. Their mean age was 53±7 years, and 69% were women. The participants in trial 2 underwent the same protocol as did the patients with COPD in trial 1. The primary outcome in trial 2 was the incidence of AMS assessed at 3100 m by the Lake Louise questionnaire score (the scale of self-assessed symptoms ranges from 0 to 15 points, indicating absent to severe, with 3 or more points including headache, indicating AMS). Results In trial 1 of patients with COPD, 68 of 90 (76%) receiving placebo and 42 of 86 (49%) receiving acetazolamide experienced ARAHE (hazard ratio, 0.54; 95% confidence interval [CI], 0.37 to 0.79; P<0.001). The number needed to treat (NNT) to prevent one case of ARAHE was 4 (95% CI, 3 to 8). In trial 2 of healthy individuals, 54 of 170 (32%) receiving placebo and 38 of 175 (22%) receiving acetazolamide experienced AMS (hazard ratio, 0.48; 95% CI, 0.29 to 0.80; chi-square statistic P=0.035). The NNT to prevent one case of AMS was 10 (95% CI, 5 to 141). No serious adverse events occurred in these trials. Conclusions Preventive treatment with acetazolamide reduced the incidence of adverse altitude effects requiring an intervention in patients with COPD and the incidence of AMS in healthy lowlanders 40 years of age or older during a high-altitude sojourn. (Funded by the Swiss National Science Foundation [Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung], Lunge Zürich, and the Swiss Lung Foundation; ClinicalTrials.gov numbers, NCT03156231 and NCT03561675.

Validation of Noninvasive Assessment of Pulmonary Gas Exchange in Patients with Chronic Obstructive Pulmonary Disease during Initial Exposure to High Altitude

Investigation of pulmonary gas exchange efficacy usually requires arterial blood gas analysis (aBGA) to determine arterial partial pressure of oxygen (mPaO2) and compute the Riley alveolar-to-arterial oxygen difference (A-aDO2); that is a demanding and invasive procedure. A noninvasive approach (AGM100), allowing the calculation of PaO2 (cPaO2) derived from pulse oximetry (SpO2), has been developed, but this has not been validated in a large cohort of chronic obstructive pulmonary disease (COPD) patients. Our aim was to conduct a validation study of the AG100 in hypoxemic moderate-to-severe COPD. Concurrent measurements of cPaO2 (AGM100) and mPaO2 (EPOC, portable aBGA device) were performed in 131 moderate-to-severe COPD patients (mean ±SD FEV1: 60 ± 10% of predicted value) and low-altitude residents, becoming hypoxemic (i.e., SpO2 < 94%) during a short stay at 3100 m (Too-Ashu, Kyrgyzstan). Agreements between cPaO2 (AGM100) and mPaO2 (EPOC) and between the O2-deficit (calculated as the difference between end-tidal pressure of O2 and cPaO2 by the AGM100) and Riley A-aDO2 were assessed. Mean bias (±SD) between cPaO2 and mPaO2 was 2.0 ± 4.6 mmHg (95% Confidence Interval (CI): 1.2 to 2.8 mmHg) with 95% limits of agreement (LoA): −7.1 to 11.1 mmHg. In multivariable analysis, larger body mass index (p = 0.046), an increase in SpO2 (p < 0.001), and an increase in PaCO2-PETCO2 difference (p < 0.001) were associated with imprecision (i.e., the discrepancy between cPaO2 and mPaO2). The positive predictive value of cPaO2 to detect severe hypoxemia (i.e., PaO2 ≤ 55 mmHg) was 0.94 (95% CI: 0.87 to 0.98) with a positive likelihood ratio of 3.77 (95% CI: 1.71 to 8.33). The mean bias between O2-deficit and A-aDO2 was 6.2 ± 5.5 mmHg (95% CI: 5.3 to 7.2 mmHg; 95%LoA: −4.5 to 17.0 mmHg). AGM100 provided an accurate estimate of PaO2 in hypoxemic patients with COPD, but the precision for individual values was modest. This device is promising for noninvasive assessment of pulmonary gas exchange efficacy in COPD patients

Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

Background Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. Methods We analysed cross-sectional data from 28 823 adults (≥40 years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income. Results Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR 1.52, 95% CI 1.19–1.94), wheeze (OR 1.37, 95% CI 1.16–1.63) and dyspnoea (OR 1.83, 95% CI 1.53–2.20), but not lower FVC (β=0.02 L, 95% CI −0.02–0.06 L) or lower FEV1/FVC (β=0.04%, 95% CI −0.49–0.58%). Some findings differed by sex and gross national income. Conclusion At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.publishedVersio

Cohort Profile: Burden of Obstructive Lung Disease (BOLD) study

The Burden of Obstructive Lung Disease (BOLD) study was established to assess the prevalence of chronic airflow obstruction, a key characteristic of chronic obstructive pulmonary disease, and its risk factors in adults (≥40 years) from general populations across the world. The baseline study was conducted between 2003 and 2016, in 41 sites across Africa, Asia, Europe, North America, the Caribbean and Oceania, and collected high-quality pre- and post-bronchodilator spirometry from 28 828 participants. The follow-up study was conducted between 2019 and 2021, in 18 sites across Africa, Asia, Europe and the Caribbean. At baseline, there were in these sites 12 502 participants with high-quality spirometry. A total of 6452 were followed up, with 5936 completing the study core questionnaire. Of these, 4044 also provided high-quality pre- and post-bronchodilator spirometry. On both occasions, the core questionnaire covered information on respiratory symptoms, doctor diagnoses, health care use, medication use and ealth status, as well as potential risk factors. Information on occupation, environmental exposures and diet was also collected

Review Essay: Is a Chilean-Style Tax on Short-Term Capital Inflows Stabilizing?

In the wake of the 1997–1998 East Asian financial crisis, some economists recommended that affected countries adopt a Chilean-style tax on short-term capital inflows to maintain domestic macroeconomic stability. In Chile, the tax reduced capital inflows lengthened the maturity of inflows, and maintained interest rates at levels designed to avoid overheating—but not costlessly. Aside from second-best arguments, such a tax is justified as a temporary measure to buy time to reform and introduce prudential regulation and supervision of a country's financial system. Would dirigiste economies use the tax to facilitate reforms and remove it after effecting prudential regulation? Copyright Kluwer Academic Publishers 2000capital controls, Chile, monetary policy,