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Mid-Holocene Northern Hemisphere warming driven by Arctic amplification.
The Holocene thermal maximum was characterized by strong summer solar heating that substantially increased the summertime temperature relative to preindustrial climate. However, the summer warming was compensated by weaker winter insolation, and the annual mean temperature of the Holocene thermal maximum remains ambiguous. Using multimodel mid-Holocene simulations, we show that the annual mean Northern Hemisphere temperature is strongly correlated with the degree of Arctic amplification and sea ice loss. Additional model experiments show that the summer Arctic sea ice loss persists into winter and increases the mid- and high-latitude temperatures. These results are evaluated against four proxy datasets to verify that the annual mean northern high-latitude temperature during the mid-Holocene was warmer than the preindustrial climate, because of the seasonally rectified temperature increase driven by the Arctic amplification. This study offers a resolution to the "Holocene temperature conundrum", a well-known discrepancy between paleo-proxies and climate model simulations of Holocene thermal maximum
The impact of Arctic sea ice loss on mid-Holocene climate.
Mid-Holocene climate was characterized by strong summer solar heating that decreased Arctic sea ice cover. Motivated by recent studies identifying Arctic sea ice loss as a key driver of future climate change, we separate the influences of Arctic sea ice loss on mid-Holocene climate. By performing idealized climate model perturbation experiments, we show that Arctic sea ice loss causes zonally asymmetric surface temperature responses especially in winter: sea ice loss warms North America and the North Pacific, which would otherwise be much colder due to weaker winter insolation. In contrast, over East Asia, sea ice loss slightly decreases the temperature in early winter. These temperature responses are associated with the weakening of mid-high latitude westerlies and polar stratospheric warming. Sea ice loss also weakens the Atlantic meridional overturning circulation, although this weakening signal diminishes after 150-200 years of model integration. These results suggest that mid-Holocene climate changes should be interpreted in terms of both Arctic sea ice cover and insolation forcing
Properties Of Analyst Forecasts And Bond Underwriting Relationship: Evidence From Korea
Previous studies find that analysts forecast earnings more optimistically but inaccurately when they face the conflict of interest (COI). We extend this line of research by examining whether analystsâ forecasting behavior affected by the mere existence of potential COI are related with underwriting contracts.We document that analysts affiliated with security companies that become underwriters ex post issue more optimistic but less accurate forecasts for firms to issue bonds in Korea. We also find that firms to issue bonds are likely to award underwriting contracts to security companies with analysts who issue more optimistic but less accurate forecasts. Â
Is Retroflexion Helpful in Detecting Adenomas in the Right Colon?: A Single Center Interim Analysis
Background/AimsColonoscopy is less effective at screening for colorectal cancer in the right side of the colon. Retroflexion during colonoscopy is expected to improve the detection rate of colorectal adenomas. The aim of the present study was to evaluate the usefulness of retroflexion in the right-sided colon.MethodsFrom April to November 2013, a total of 398 patients were enrolled in this study. For each patient, a cap-assisted colonoscopic examination was performed. After cecal intubation, a forward view examination from the cecum up to the hepatic flexure was performed and all identified polyps were removed. The colonoscope was reinserted to the cecum, and a careful second forward view examination of the cecum to the hepatic flexure was performed, with removal of additionally identified polyps. The colonoscope was then reinserted to the cecum and retroflexed; a third colonoscopic examination was then performed to the hepatic flexure in retroflexion with removal of additional polyps. Total polyp numbers and characteristics were compared between the two forward view examinations and the retroflexion examination.ResultsA successful retroflexion was performed in 90.2% of patients. A total of 213 polyps and 143 adenomas were detected in the right-sided colon using the routine method of examining the right colon twice in forward view. An additional 35 polyps and 24 adenomas were detected on retroflexion. Of these 35 polyps, 27 (77.1%) were small-sized polyps (â¤5 mm) and 24 (71.4%) were adenomas. Finding additional adenomas using the retroflexion technique was associated with older age.ConclusionsColonoscopic retroflexion is helpful in the detection of cecum and ascending colon adenomas, especially small-sized adenomas (â¤5 mm). It is particularly useful in older patients
Short-Term Effects of Ginkgo biloba Extract on Peripapillary Retinal Blood Flow in Normal Tension Glaucoma
PURPOSE: Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG).
METHODS: Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed.
RESULTS: After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area.
CONCLUSIONS: GBE administration appears to have desirable effect on ocular blood flow in NTG patients.ope
Acute Symptoms after a Community Hydrogen Fluoride Spill
OBJECTIVES: This study was conducted to describe the demographic characteristics, and clinical signs and symptoms of patients who visited a general hospital because of the release of chemically hazardous hydrogen fluoride that occurred on September 27, 2012 in Gumi City, Korea. METHODS: The medical records at 1 general hospital 9 km from the accident site were reviewed using a standardized survey format. There were 1,890 non-hospitalized and 12 hospitalized patients exposed to hydrogen fluoride between September 27 and October 13 2012. RESULTS: Among the 12 hospitalized patients, 11 were discharged within 1 week and the other was hospitalized for 10 days. The chief complaints were respiratory symptoms such as hemoptysis and shortness of breath, gastrointestinal symptoms, neurologic symptoms, sore throat, and lip burn. The number of non-hospitalized patients exhibited a bimodal distribution, peaking on the first and twelfth days after the accident. Their chief complaints were sore throat (24.1%), headache (19.1%), cough (13.1%), and eye irritation (9.2%); some patients were asymptomatic (6.2%). Patients who visited the hospital within 3 days (early patients) of the spill more often had shortness of breath (27.0%) and nausea (6.3%) as the chief complaints than patients who visited after 3 days (late patients) (3.5% and 2.6%, respectively). However, cough and rhinorrhea were more common in the late patients (14.0% and 3.3%, respectively) than in the early patients (5.0% and 0.0%, respectively). Patients who were closer to the accident site more often had shortness of breath and sputum as the chief complaints than patients who were farther away. The mean serum calcium concentration was 9.37 mg/dL (range: 8.4â11.0 mg/dL); none of the patients had a decreased serum calcium level. Among 48 pulmonary function test results, 4 showed decreased lung function. None of the patients had abnormal urine fluoride levels on the eighth day after exposure. CONCLUSIONS: Patients hospitalized due to chemical hazard release of hydrogen fluoride had acute respiratory, gastrointestinal, and neurologic health problems. Non-hospitalized patients have acute symptoms mainly related to upper respiratory irritation
Occupational Factors Associated with Changes in the Body Mass Index of Korean Male Manual Workers
OBJECTIVES: This study was carried out to analyze and compare the occupational factors that could influence changes in body mass index (BMI) in male manual workers stratified into short-term and long-term work experience groups. METHODS: The subjects were 299 male manual workers (sampled systematically) from 27 workplaces, who had undergone travelling medical examinations at a university hospital between March 28 and May 10, 2013, and had also undergone medical examinations at the same hospital in 2012. Their general and occupational characteristics were investigated through a structured, self-administered questionnaire. The BMI at each point in time was calculated based on the anthropometric results of the medical examinations. Multiple regression analyses were conducted on outcomes of the BMI change and predictors composed of the general and occupational characteristics, with the subjects stratified into groups with 5Â years or less (short-term) versus more than 5Â years (long-term) of work experience at the present post. RESULTS: In the short-term work experience group, the BMI increases of 3-shift workers and groups reporting disagreement with feeling âinsufficient job controlâ and âlack of rewardâ at work, two of the subscales of job stress, were significantly higher than those of daytime workers and high-stress groups, respectively. In the long-term work experience group, However, although the BMI increase for 3-shift workers was also significantly higher than that of daytime workers, none of the job stress factors were significantly associated with a BMI increase, whereas the social factors of education and marital status were significant, and some lifestyle factors (such as smoking and regular exercise) were also significant. CONCLUSION: This study showed that, except for 3-shift work, the factors associated with BMI increase could differ depending on the length of job experience. Consequently, different strategies may be needed for workers with short-term versus long-term job experience when designing interventions for preventing their obesity
Incomplete Distal Renal Tubular Acidosis with Nephrocalcinosis
We report the case of a female patient with incomplete distal renal tubular acidosis with nephrocalcinosis. She was admitted to the hospital because of acute pyelonephritis. Imaging studies showed dual medullary nephrocalcinosis. Subsequent evaluations revealed hypokalemia, hypocalcemia, hypercalciuria, and hypocitraturia with normal acid-base status. A modified tubular acidification test with NH4Cl confirmed a defect of urine acidification, which is compatible with incomplete distal tubular acidosis. We treated our patient with potassium citrate, which corrects hypokalemia and prevents further deposition of calcium salts
Hyponatremia in a Patient with a Sellar Mass
A 59-year-old man with confused mental status was admitted to our hospital. Laboratory reports showed him to have severe hyponatremia, and additional studies revealed panhypopituitarism. Brain magnetic resonance imaging showed a sellar cystic lesion, which consisted of a Rathke cleft cyst. Thus, the mass effect of the Rathke cleft cyst resulted in panhypopituitarism and finally induced euvolemic hyponatremia. On the basis of these results, supplementation with thyroid hormone and glucocorticoid was started, and the patient's serum sodium level was gradually corrected and maintained within the normal range. Here, we report this case of euvolemic hyponatremia caused by a Rathke cleft cyst
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