Flood Risk Analysis and Flood Potential Losses Assessment

The heavy floods in the Taihu Basin showed increasing trend in recent years. In this work, a typical area in the northern Taihu Basin was selected for flood risk analysis and potential flood losses assessment. Human activities have strong impact on the study area’s flood situation (as affected by the polders built, deforestation, population increase, urbanization, etc.), and have made water level higher, flood duration shorter, and flood peaks sharper. Five years of different flood return periods [(1970), 5 (1962), 10 (1987), 20 (1954), 50 (1991)] were used to calculate the potential flood risk area and its losses. The potential flood risk map, economic losses, and flood-impacted population were also calculated. The study’s main conclusions are: 1) Human activities have strongly changed the natural flood situation in the study area, increasing runoff and flooding; 2) The flood risk area is closely related with the precipitation center; 3) Polder construction has successfully protected land from flood, shortened the flood duration, and elevated water level in rivers outside the polders; 4) Economic and social development have caused flood losses to increase in recent years.

Assessment of Balance and Vestibular Functions in Patients with Idiopathic Sudden Sensorineural Hearing Loss

This study investigated the relationship among the severity of hearing impairment,vestibular function and balance function in patients with idiopathic sudden sensorineural hearing loss（ISSNHL）.A total of 35 ISSNHL patients（including 21 patients with vertigo） were enrolled.All of the patients underwent audiometry,sensory organization test（SOT）,caloric test,cervical vestibular-evoked myogenic potential（cV EMP） test and ocular vestibular-evoked myogenic potential（o VEMP） test.Significant relationship was found between vertigo and hearing loss grade（P=0.009）,and between SOT VEST grade and hearing loss grade（P=0.001）.The abnormal rate of o VEMP test was the highest,followed by the abnormal rates of caloric and c VEMP tests,not only in patients with vertigo but also in those without vertigo.The vestibular end organs were more susceptible to damage in patients with vertigo（compared with patients without vertigo）.Significant relationship was found between presence of vertigo and SOT VEST grade（P=0.010）.We demonstrated that vestibular end organs may be impaired not only in patients with vertigo but also in patients without vertigo.The cochlear and vestibular impairment could be more serious in patients with vertigo than in those without vertigo.Vertigo does not necessarily bear a causal relationship with the impairment of the vestibular end organs.SOT VEST grade could be used to reflect the presence of vertigo state in the ISSNHL patients.Apart from audiometry,the function of peripheral vestibular end organs and balance function should be evaluated to comprehensively understand ISSNHL.Better assessment of the condition will help us in clinical diagnosis,treatment and prognosis evaluation of ISSNHL.

Evaluation of call options

The European and American call options, for which the prices of their underlying asset follow compound Poisson process, are evaluated by a probability method. Formulas that can be used to evaluate the options are obtained, which include not only the elements of an option: the price of the call option, the exercise price and the expiration date, but also the riskless interest rate, nevertheless exclude the volatility of the underlying asset. In practice, the evaluated results obtained by these formulas can provide references of making strategic decision for an investor who buys the call option and a company who sells the call option.

Capacity of soil loss control in the Loess Plateau based on soil erosion control degree

The capacity of soil and water conservation measures, defined as the maximum quantity of suitable soil and water conservation measures contained in a region, were determined for the Loess Plateau based on zones suitable for establishing terraced fields, forestland and grassland with the support of geographic information system(GIS) software. The minimum possible soil erosion modulus and actual soil erosion modulus in 2010 were calculated using the revised universal soil loss equation(RUSLE), and the ratio of the minimum possible soil erosion modulus under the capacity of soil and water conservation measures to the actual soil erosion modulus was defined as the soil erosion control degree. The control potential of soil erosion and water loss in the Loess Plateau was studied using this concept. Results showed that the actual soil erosion modulus was 3355 t·km^(–2)·a^(–1), the minimum possible soil erosion modulus was 1921 t·km^(–2)·a^(–1), and the soil erosion control degree was 0.57(medium level) in the Loess Plateau in 2010. In terms of zoning, the control degree was relatively high in the river valley-plain area, soil-rocky mountainous area, and windy-sandy area, but relatively low in the soil-rocky hilly-forested area, hilly-gully area and plateau-gully area. The rate of erosion areas with a soil erosion modulus of less than 1000 t·km^(–2)·a^(–1) increased from 50.48% to 57.71%, forest and grass coverage rose from 56.74% to 69.15%, rate of terraced fields increased from 4.36% to 19.03%, and per capita grain available rose from 418 kg·a^(–1) to 459 kg·a^(–1) under the capacity of soil and water conservation measures compared with actual conditions. These research results are of some guiding significance for soil and water loss control in the Loess Plateau.

Prophylactic effect of Ca^(2+)-deficient artificial perilymph perfusion on noise-induced hearing loss

Objective To investigate the prophylactic effect of low calcium concentration perilymph on noise-induced hearing loss. Methods Forty guinea pigs with normal hearing weighing 250-350 g were assigned to five groups (8 in each group): (1) Ca2+-deficient perilymph perfusion (CDP) for 2 h; (2) white noise (120 dB SPL) exposure (WNE) only for 1 h, (3) combination of calcium-deficient perilymph perfusion and white noise (120 dB SPL) exposure (WNE+CDP); (4) normal artificial perilymph (NAP) perfusion for 2 h; and (5) white noise exposure + normal artificial perilymph perfusion (WNE+NAP) for 2 h. Compound action potentials (CAP) evoked by click was recorded from round window every 15 min. The cochleae from 5 animals in each group were examined with scanning electron microscope. Results The CAP for group 1 experienced a threshold shift (TS) of 15-26 dB, while group 2 yielded a 46-59 dB TS and group 3 a 37-45 dB TS; no threshold shift occurred in group 4. The CAP TS in group 5 was 33-64 dB. The CAP TS of group 3 was less than that of group 2. After one hour of noise exposure, the CAP TS of group 3 were 45.92±2.90 dB and 59.30±3.95dB in group 2. There were significant differences (P<0.05) between groups 3 and 2. The CAP TS of group 3 was less than that of group 5 at the points of 1, 1.5 and 2 h after noise exposure. There was a significant difference between groups 3 and 5 (P<0.01). Stereocilia of 89 OHC3 were in disarray in five cochleae after noise exposure in group 2. The cuticular plates of 8 OHC2,3 sank and the stereocilia became fused in only one animal cochlea after noise exposure in group 3 combined with low calcium perilymph perfusion. Conclusions Low calcium concentration appears to participate in preventing noise-induced hearing loss and the rising of calcium concentrations in inner hair cells after noise exposure, which may have been due to the opening of calcium channels in inner hair cells during noise exposure. The mechanism of the prophylactic effect might be caused by a lower calcium concentration in inner hair cells in the cochlea attenuating the influence of noise exposure on hearing loss; calcium deficient perilymph perfusion prevented calcium accumulation in inner hair cells of the cochlea. The motility of the OHCs might be partially inhibited by low calcium concentration that reduced noise-induced hearing loss in turn.