低音提琴高级技巧训练的新思维

随着精神文明的提高,人们对高雅艺术的认知和喜爱也与日俱增。低音提琴以其浑厚的音色、粗犷雄伟的声响,吸引了越来越多的音乐爱好者们。选择学习低音提琴的学员也具有了越来越高的艺术素养和优越的学习氛围。本文针对传统的低音提琴训练方法,加以改进使之适合更高的演奏要求,并胜任大量高难技术作品片段。使我们的教学和训练能够＂与时俱进＂跟得上时代的步伐。

Clinical presentation and genotype of hepatitis delta in Karachi

AIM： To assess the clinical presentation and genotypes of delta hepatitis in local population. METHODS： In this prospective study, 39 consecutive patients who were positive for HBsAg and hepatitis D virus （HDV） antibody were included. The patients were divided in two groups on the basis of presence or absence of HDV RNA and a comparative study was done. Genotype of HDV was determined in PCR positive patients. RESULTS： Overall there is male dominance, in which 34 patients out of 39 （87.2%） were male. Twenty （51%） patients were from the adjacent areas of three provinces; Sindh, Punjab and Balochistan indicating the higher prevalence of delta hepatitis in this mid region of Pakistan. Patients of all age groups were affected with delta hepatitis （median 31.5 years, range 12-75）. HDV RNA was detectable in 23 patients （59%）. All the HDV strains belonged to genotype I. HBV DNA was detectable only in 3 cases who were also HBeAg and HDV RNA positive. Patients with detectable HDV RNA were younger than patients with undetectable RNA; mean age 29.7±12.8 years vs 36.8±15.2. There were no statistically significant differences in the clinical presentation and routine biochemical profile of patients with detectable or undetectable HDV RNA. Clinical cirrhosis was present in 19 （49%） patients; 12 with detectable RNA and 7 with undetectable HDV RNA （P = 0.748）. Decompensated disease was seen in eight patients; five and three respectively from each group. Four patients with undetectable RNA and two patients with detectable RNA had normal ALT and ultrasound abdomen. CONCLUSION： HDV may infect at any age, usually young adult males. Genotype I is prevalent. With time some of the patients become HDV RNA negative or asymptomatic carrier. Most of the patients have suppressed HBV DNA replication. Significant numbers of patients have cirrhosis.

Prevalence of non-Helicobacter pylori duodenal ulcer in Karachi,Pakistan

AIM:To determine the prevalence of non-Helicobacter pylori (H pylori)-related duodenal ulcer in patients with acid-peptic diseases. METHODS: Medical records of patients who attended the Gastroenterology Department at Aga Khan University Hospital from 1999 to 2001 and had endoscopic diagnosis of duodenal ulcers were reviewed. Duodenal ulcer associated with H pylori was diagnosed on the basis of endoscopy, rapid urease test and histopathology whereas histories of aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) related duodenal ulcers. Non-H pylori, non-NSAID duodenal ulcers were those without H pylori infection and history of NSAID intake. Co-morbid conditions associated were noted. RESULTS: Of 2 260 patients, 10% (217/2 260) had duodenal ulcer. Duodenal ulcer related to H pylori infection accounted for 53% (116/217), NSAID-related 10% (22/217), non-H pylori non-NSAID 29% (62/217), and 8% (17/217) had both H pylori infection and histories of NSAID intake. Fifteen percent (18/116)_patients had past histories of peptic ulcer disease in H pylori infection, while 8% (5/62) in non-H pylori non-NSAID ulcer. Co-morbid conditions in H pylori infection were seen in 23% (27/116) and 34% (21/62) in non-H pylori non-NSAID ulcer. CONCLUSION: Incidence of H pylori infection related with duodenai ulcer is common. In the presence of co-morbids, non-H pylori and non-NSAID duodenal ulcer is likely to be present.

Assimilating the LAI Data to the VEGAS Model Using the Local Ensemble Transform Kalman Filter: An Observing System Simulation Experiment

Information on the spatial and temporal patterns of surface carbon flux is crucial to understanding of source/sink mechanisms and projection of future atmospheric CO2 concentrations and climate. This study presents the construction and implementation of a terrestrial carbon cycle data assimilation system based on a dynamic vegetation and terrestrial carbon model Vegetation-Global-Atmosphere-Soil(VEGAS) with an advanced assimilation algorithm, the local ensemble transform Kalman filter(LETKF, hereafter LETKF-VEGAS). An observing system simulation experiment(OSSE) framework was designed to evaluate the reliability of this system, and numerical experiments conducted by the OSSE using leaf area index(LAI) observations suggest that the LETKF-VEGAS can improve the estimations of leaf carbon pool and LAI significantly, with reduced root mean square errors and increased correlation coefficients with true values, as compared to a control run without assimilation. Furthermore, the LETKF-VEGAS has the potential to provide more accurate estimations of the net primary productivity(NPP) and carbon flux to atmosphere(CFta).

Hydrography and Circulation in the Eastern Tropical Indian Ocean during April-May 2011

The distribution of hydrography and circulation in the eastern tropical Indian Ocean(ETIO) during April-May 2011 were analyzed using cruise observations,satellite observations,and historic hydrographic data.It was observed that warm water(>28℃) occupies the upper 50-m layer in the ETIO.Low-salinity surface water was observed at the mouth of the Bay of Bengal(BOB),which further extends to the Arabian Sea and off Sumatra via the Sri Lanka coast and the eastern bay mouth.Arabian Sea high-salinity water(ASHSW) is carried eastward along the equator to around 90°E by the equatorial undercurrent(EUC).It also runs south of Sri Lanka(north to 3°N) and in the western bay mouth(west to 87°E) but is much shallower than its counterpart at the equator.It is suggested to be the residual of the ASHSW,which intrudes into the BOB during the preceding southwest monsoon.Our results also show that,in the south of Sri Lanka,just below this subsurface high-salinity water,very-low-salinity water(about 34.8) occurs at depths of 100-200 m.Further analysis suggests that this low-salinity water comes from the BOB.