International Business Cycle Synchronization in Historical Perspective

In this paper, we review and attempt to explain the changes in business cycle synchronization among 16 industrial countries and the over the past century and a quarter, demarcated into four exchange rate regimes. We find that there is a secular trend towards increased synchronization for much of the twentieth century and that it occurs across diverse exchange rate regimes. This finding is in marked contrast to much of the recent literature, which has focused primarily on the evidence for the past 20 or 30 years and which has produced mixed results. We then examine the role of global shocks and shock transmission in the trend toward synchronization. Our key finding here is that global (common) shocks generally are the dominant influence.

Antagonistic and synergistic responses to solar ultraviolet radiation and increased temperature of phytoplankton from cenotes (sink holes) of the Yucatán Peninsula, México

Cenotes (sink holes) are karstic formations characteristic of the Yucatán Peninsula and are the main source of fresh water in the region. Because of their tropical location, they receive high levels of solar radiation and are exposed to high temperatures. However, the effect of these global-change-related variables on phytoplankton in cenotes is unknown. We carried out experiments with phytoplankton communities collected from 2 cenotes differing in their penetration of solar radiation (Leona Vicario [LV]: turbid, Las Mojarras [LM]: clear) to assess the combined effect of solar ultraviolet radiation (UVR; 280–400 nm) and increased temperature on their photosystem (PS) II photochemistry. We exposed samples in microcosms to solar radiation (with and without UVR) and 2 temperatures (ambient = 25°C and increased by 3°C) and analyzed photochemical performance over daily cycles. A significant antagonistic interaction between UVR and temperature in LV caused a combined inhibition of the effective photochemical quantum yield (ΦPSII) that was smaller (63%) than the sum of the 2 individual effects of UVR and temperature (116%). In contrast, a significant synergistic interaction between UVR and temperature in LM caused the combined inhibition of ΦPSII (172%) to be higher than the sum of the individual effects of the 2 variables (134%). Differences in the size distribution and taxonomic composition of the phytoplankton communities, with smaller cells in LV than in LM, seem to account for much of the variability in responses to UVR and increased temperature between the 2 communities. Our results suggest that phytoplankton communities from clear cenotes will be more affected by the combined effects of solar UVR and increased temperature that those from turbid cenotes.Fil: Villafañe, Virginia Estela. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guendulain García, Sergio D.. Universidad Nacional Autónoma de México; MéxicoFil: Valadez, Francisco. Universidad Juárez Autónoma de Tabasco; México. Centro de Investigación Científica de Yucatán; MéxicoFil: Rosiles González, Gabriela. Centro de Investigación Científica de Yucatán; MéxicoFil: Helbling, Eduardo Walter. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Banaszak, Anastazia T.. Universidad Nacional Autónoma de México; Méxic

Combined Effects of UVR and Temperature on the Survival of Crab Larvae (Zoea I) from Patagonia: The Role of UV-Absorbing Compounds

The aim of our study was to assess the combined impact of UVR (280–400 nm) and temperature on the first larval stage (Zoea I) of three crab species from the Patagonian coast: Cyrtograpsus altimanus, C. angulatus, and Leucippa pentagona. We determined the survival response of newly hatched Zoea I after being exposed for 8–10 h under a solar simulator (Hönle SOL 1200) at 15 and 20 °C. There was no mortality due to Photosynthetic Active Radiation (PAR, 400–700 nm) or ultraviolet-A radiation (UV-A, 315–400 nm), and all the observed mortality was due to ultraviolet-B radiation (UV-B, 280–315 nm). The data of larval mortality relative to exposure time was best fit using a sigmoid curve. Based on this curve, a threshold (Th) and the lethal dose for 50% mortality (LD50) were determined for each species. Based on the Th and LD50, C. altimanus was found to be the most resistant species, while L. pentagona was found to be the most sensitive to UV-B. For both species of Cyrtograpsus, mortality was significantly lower at 20 °C than at 15 °C; however, no significant differences between the two temperature treatments were found in L. pentagona. Bioaccumulation of UV-absorbing compounds in the gonads and larvae of C. altimanus, and to a lesser extent in C. angulatus, might have contributed for counteracting the impact of UV-B. However, most of the resilience to UV-B observed with the increase in temperature might be due to an increase in metabolic activity caused by a repair mechanism mediated by enzymes

Cogan's syndrome: clinical evolution of deafness and vertigo in three patients

The aim of this study was to evaluate the clinical symptoms, the otoneurological examinations, the treatment and the clinical course of three patients suffering from Cogan's syndrome, a rare disease based on the clinical association of a non-syphilitic interstitial keratitis with a cochleo-vestibular deficit. This case series involved three patients with follow up. The clinical course of the three patients (aged 30, 48 and 49years) with Cogan's syndrome during a follow-up period of 2 to 6years is reported. All patients underwent complete otoneurological, ophthalmologic and rheumatologic examinations and were treated with immunosuppressive therapy such as glucocorticoids and cyclophosphamide in two and glucocorticoids and methotrexate in one patient. Using immunosuppressive therapy, ophthalmologic symptoms disappeared rapidly in two patients. Hearing improved only in one and stabilized in a second patient. One patient died after 6years of treatment because of complications of generalized vasculitis. Early diagnosis and rapid initiation of a combined immunosuppressive therapy such as corticosteroids and cyclophosphamide seem to be important in controlling the disease and avoiding persistent deafness. Whether systemic complications and a fatal outcome also can be prevented is still questionabl

Ultrasound assessment of transversus abdominis muscle contraction ratio during abdominal hollowing: a useful tool to distinguish between patients with chronic low back pain and healthy controls?

Spine stabilisation exercises, in which patients are taught to preferentially activate the transversus abdominus (TrA) during "abdominal hollowing” (AH), are a popular treatment for chronic low back pain (cLBP). The present study investigated whether performance during AH differed between cLBP patients and controls to an extent that would render it useful diagnostic tool. 50patients with cLBP (46.3±12.5years) and 50healthy controls (43.6±12.7years) participated in this case-control study. They performed AH in hook-lying. Using M-mode ultrasound, thicknesses of TrA, and obliquus internus and externus were determined at rest and during 5s AH (5measures each body side). The TrA contraction-ratio (TrA-CR) (TrA contracted/rest) and the ability to sustain the contraction [standard deviation (SD) of TrA thickness during the stable phase of the hold] were investigated. There were no significant group differences for the absolute muscle thicknesses at rest or during AH, or for the SD of TrA thickness. There was a small but significant difference between the groups for TrA-CR: cLBP 1.35±0.14, controls 1.44±0.24 (p<0.05). However, Receiver Operator Characteristics (ROC) analysis revealed a poor and non-significant ability of TrA-CR to discriminate between cLBP patients and controls on an individual basis (ROC area under the curve, 0.60 [95% CI 0.495; 0.695], p=0.08). In the patient group, TrA-CR showed a low but significant correlation with Roland Morris score (Spearman Rho=0.328; p=0.02). In conclusion, the difference in group mean values for TrA-CR was small and of uncertain clinical relevance. Moreover, TrA-CR showed a poor ability to discriminate between control and cLBP subjects on an individual basis. We conclude that the TrA-CR during abdominal hollowing does not distinguish well between patients with chronic low back pain and healthy control

Outcome of treatment of pulmonary tuberculosis in Switzerland in 1996.

Adequate treatment of pulmonary tuberculosis cures patients and reduces transmission. The study assesses treatment outcomes under current conditions in Switzerland. Retrospective cohort study including all TB cases with positive sputum cultures notified to the national surveillance system between July 1996 and June 1997. Ten months after notification, treating physicians reported the outcomes using WHO categories. Of 265 patients, 209 (79%) completed at least 6 months' treatment, 3 (1%) were treatment failures, 23 (9%) died, 8 (3%) defaulted from treatment and 22 (8%) left the country. The proportion of successful treatments did not significantly differ between the 103 Swiss-born (80%) and the 162 foreign-born (78%) patients. There were 19 deaths (18%) in the Swiss-born and 4 (2%) in the foreign-born groups; death was caused by TB in two patients, 10 died of other causes (cause unknown in 11). In the foreign-born group there were 31 (19%) potentially unsatisfactory outcomes (treatment failure, default from treatment, transfer abroad) and in the Swiss-born group 2 (2%). Default from treatment involved 8 patients, 6 of whom were asylum seekers. In a multivariate analysis potentially unsatisfactory outcomes were not significantly associated with foreign origin but with status as a foreigner of irregular or unknown legal status (adj. OR 8.8; 95% CI 1.4 to 53.7). Overall treatment success rates are satisfactory and similar to those of other western European countries. Potentially unsatisfactory outcomes are more common in foreign-born persons of irregular legal status. Tracking of non-adherent patients by health workers could further improve outcomes

Effects of UV radiation on aquatic ecosystems and interactions with climate change

The health of freshwater and marine ecosystems is critical to life on Earth. The impact of solar UV-B radiation is one potential stress factor that can have a negative impact on the health of certain species within these ecosystems. Although there is a paucity of data and information regarding the effect of UV-B radiation on total ecosystem structure and function, several recent studies have addressed the effects on various species within each trophic level. Climate change, acid deposition, and changes in other anthropogenic stressors such as pollutants alter UV exposure levels in inland and coastal marine waters. These factors potentially have important consequences for a variety of aquatic organisms including waterborne human pathogens. Recent results have demonstrated the negative impacts of exposure to UV-B radiation on primary producers, including effects on cyanobacteria, phytoplankton, macroalgae and aquatic plants. UV-B radiation is an environmental stressor for many aquatic consumers, including zooplankton, crustaceans, amphibians, fish, and corals. Many aquatic producers and consumers rely on avoidance strategies, repair mechanisms and the synthesis of UV-absorbing substances for protection. However, there has been relatively little information generated regarding the impact of solar UV-B radiation on species composition within natural ecosystems or on the interaction of organisms between trophic levels within those ecosystems. There remains the question as to whether a decrease in population size of the more sensitive primary producers would be compensated for by an increase in the population size of more tolerant species, and therefore whether there would be a net negative impact on the absorption of atmospheric carbon dioxide by these ecosystems. Another question is whether there would be a significant impact on the quantity and quality of nutrients cycling through the food web, including the generation of food proteins for humans. Interactive effects of UV radiation with changes in other stressors, including climate change and pollutants, are likely to be particularly important.Fil: Häder, D. P.. No especifíca;Fil: Helbling, Eduardo Walter. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Williamson, C. E.. Miami University; Estados UnidosFil: Worrest, R. C.. No especifíca

Prospective randomized trial comparing sutured with sutureless mesh fixation for Lichtenstein hernia repair: long-term results

Background: Following Lichtenstein hernia repair, up to 25% of patients experience prolonged postoperative and chronic pain as well as discomfort in the groin. One of the underlying causes of these complaints are the compression or irritation of nerves by the sutures used to fixate the mesh. We compared the level and rate of chronic pain in patients operated with the classical Lichtenstein technique fixated by sutures to patients with sutureless mesh fixation technique. Methods: A two-armed randomized trial with 264 male patients was performed. After consent, patients were randomized preoperatively. For the fixation of the mesh we used either sutures with slow-absorbing material (PDS 2.0) (group I, n=133) or tissue glue (Histoacryl) (group II, n=131). Follow-up examinations were performed after 3, 12months and after 5years. Results: Patient characteristics in the two groups were similar. No cross-over between groups was observed. After 5years, long-term follow-up could be completed for 59% of subjects. After 5years, 10/85 (11.7%) patients in group I and 3/70 (4.2%) in group II suffered from chronic pain in the groin region (P=0.108). The operation time was significantly shorter in group II (79min vs 73min, P=0.01). One early recurrence occurred in group II (3months). The recurrence rate was 0 and 0% after 12months and 5.9% (5/85) and 10% (7/70) after 5years in group I and group II, respectively (P=0.379). Conclusion: After 5years, the two techniques of mesh fixation resulted in similar rates of chronic pain. Whereas recurrence rates were comparable, fixation of the mesh with tissue glue decreased operating room time significantly. Hence, suture less mesh fixation with Histoacryl is a sensible alternative to suture fixation and should be especially considered for patients prone to pai