Yichang City Research Articles

A Hybrid Model for Short-Term Bacillary Dysentery Prediction in Yichang City, China

Bacillary dysentery is still a common and serious public health problem in China. This paper is aimed at developing and evaluating an innovative hybrid model, which combines the seasonal autoregressive integrated moving average (SARIMA) and the generalized regression neural network (GRNN) models, for bacillary dysentery forecasting. Data of monthly bacillary dysentery incidence in Yichang City from 2000-2007 was obtained from Yichang Disease Control and Prevention Center. The SARIMA and SARIMA-GRNN model were developed and validated by dividing the data file into two data sets: data from the past 5 years was used to construct the models, and data from January to June of the 6th year was used to validate them. Simulation and forecasting performance was evaluated and compared between the two models. The hybrid SARIMA-GRNN model was found to outperform the SARIMA model with the lower mean square error, mean absolute error, and mean absolute percentage error in simulation and prediction results. Developing and applying the SARIMA-GRNN hybrid model is an effective decision supportive method for producing reliable forecasts of bacillary dysentery for the study area.

Assessing the effectiveness of a school‐based oral health promotion programme in Yichang City, China

To assess the outcome of oral health promotion in schoolchildren over a 3-year period in Yichang City, Hubei, China. In a cluster randomized controlled trial, the concept of the World Health Organization Health Promoting Schools Project was applied to primary schoolchildren. Seven intervention schools and eight control schools were randomly selected from one district by stratified cluster sampling. The study was conducted as a 3-year follow-up study. After 3 years, 661 children remained in the intervention group and 697 children in the control group. Data on dental caries, plaque accumulation, and sulcus bleeding were collected by clinical examination, while behavioural data were gathered by self-administered questionnaires. The 3-year net mean DMFS increment score was 0.22 in the intervention schools and 0.35 in the control schools (P < 0.013). A statistically significant difference in mean plaque (P < 0.013) and sulcus bleeding (P < 0.005) increment scores after 3 years was found between the two groups. Statistically significant higher scores were observed in restorations received and sealants placed, and a lower score in untreated dental caries, in children from the intervention group than the control group after 3 years (P < 0.01). In addition, more children in the intervention schools adopted regular oral health behavioural practices such as brushing their teeth at least twice a day, visiting the dentist within the past calendar year, and using fluoride toothpaste. The study suggests that the school-based oral health promotion was an effective way to reduce new caries incidence, improve oral hygiene and establish positive oral health behavioural practices in the targeted schoolchildren.

The Global Stratotype Section and Point for the base of the Middle Ordovician Series and the Third Stage (Dapingian)

The Huanghuachang section near Yichang, southern China was successively approved by ISOS, recognized by ICS and then officially ratified as being the Global Stratotype Section and point (GSSP) for the base of the Middle Ordovician Series and the Third Stage, named as Dapingian, of the Ordovician System. The conodont succession at the section is complete across the Lower to Middle Ordovician series boundary and several excellent phylogenetic lineages of Baltoniodus, Gothodus, Microzarkodina and Periodon are represented. The base of the Middle Ordovician Series and the Daping Stage is defined at a point 10.57 m above the base of the Dawan Formation at the base of Bed SHod-16 of the Huanghuachang section, 22km NE of Yichang City, Hubei Province, South China. It coincides with the first appearance datum (FAD ) of the conodont species Baltoniodus triangularis within the Baltoniodus lineage starting from Baltoniodus cf. B. triangularis to Baltoniodus navis. It is associated with the FAD of Periodon sp. A and followed closely by the FAD of Microzarkodina flabellum, which is taken as a reasonable proxy for the boundary. This level approximates the boundary between the lower and upper Azygograptus suecicus graptolite Biozone, and nearly coincides with the base of the Belonechitina cf. henryi chitinozoan Biozone. The same faunal succession is also recorded from the Chenjiahe section, near Daping village, 5 km to the north of the Huanghuachang section. The proposed boundary level, which has long been used in other important Ordovician successions worldwide, can be easily recognized and correlated globally with high precision in both relatively shallow

Timing of the Yangtze initiation draining the Tibetan Plateau throughout to the East China Sea: a review

The question of the Yangtze’s origins has been extensively researched by geologists and geomorphologists for more than a century, and a widely-accepted answer is still pending. Evidence of river piracy, diversion and incision in the upper river segment from Shigu town in Yunnan Province to Yichang City has been used to reconstruct the history of the Yangtze drainage system, and constrain the timing of the upper Yangtze diversion from south flowing to east, debouching into the East China Sea. There is much diversity in fluvial deposits and landforms even over small spatio-temporal scales in tectonic highly active regions. They are also liable to latter reworking by external forces, making their paleo-geographical interpretation a more complex and controversial matter. Based on evidence from fluvial strata and landforms, various hypotheses have been proposed with considerable discrepancies for the timing of the Jinsha River diversion from the south flowing into the east, and the timing of the upper Yangtze channeling through the Three Gorges area. The Yangtze was controversially assumed to be: (1) a very old river in existence since the Cretaceous and earlier, (2) a very young river that came into being only during the past several hundred thousand years, or (3) any age in between these two extremes.

Conodont zonation across the Permian–Triassic boundary at the Xiakou section, Yichang city, Hubei Province and its correlation with the Global Stratotype Section and Point of the PTB

Xiakou section is situated north of the central Yangtze platform with successive Late Permian to Early Triassic strata, thicker than the Global Stratotype Section and Point (GSSP) of the Permian–Triassic boundary (PTB). We recognized three conodont zones across the PTB in this section by high-precision biostratigraphy. They are the Hindeodus latidentatus – Clarkina meishanensis Zone, Hindeodus parvus Zone, and Isarcicella isarcica Zone in ascending order, which correspond well with the GSSP. The present biostratigraphic work on Xiakou section certainly confirmed the conodont zonation through the PTB at the GSSP and also testified to the correctness of the PTB demarcation in Xiakou section. Based on this precise demarcation of the PTB, the appearance of a clay layer, bed ZSJI266, just beneath the PTB should be an important advantage over the GSSP, because this clay layer approaches to the PTB much in contrast with those two clay layers, bed 26 and bed 28, in the GSSP. Therefore, the radiometric isotopic dating in bed ZSJI266 at Xiakou section should give a more accurate age for the PTB.

A developed technology for wet-ground fine cement slurry with its applications

In order to reduce grouting costs, a new preparation technology for wet-ground fine cement (WFC) was developed. After grinding by this method, the maximum size of cement particles in slurry is not bigger than 40 μm and the medium size (50% by weight) is less than 10 μm; thus, the slurry can be used to inject a rock body with micro-fissures. This newly developed grouting technology with the special gear-grinder has been used successfully in some hydropower projects in China such as Wan'an Project in Jiangxi province and the Three Gorges Project in Yichang city.

Two new species of the Bonziinae from China (Acari: Cunaxidae)

One new species of the genus Parabonzia Smiley and one new species of Neoscirula Den Heyer are described and illustrated. Parabonzia zhangi sp. nov. was found in soil in a hole in the tree Platanus hispanica Muenchh in Yichang city, Hubei province, while Neoscirula saitoi sp. nov. was collected on the bark of P. hispanica in Shunchang county, Fujian province. Types were deposited in the collection of Plant Protection Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China.

Assessment of economic development for Three Gorges Reservior Area

Economic development of Three Gorges Reservoir Area remains backward. Here, per capita GNP and per capita national income are far less than that of Sichuan Province, Hubei Province and China respectively. Its industrial structure shows the characteristics of early phase of industrializing process. Economic development of the counties close to Chongqing City and Yichang City are more advanced than these counties located in the central part of the reservoir area. At present, economic development for the reservoir area runs into the difficulties: low profit in the leading industries, loss incurred in state-owned enterprises, small scale in most of enterprises and weak economic core of the cities and towns in the area. It is the best way for the reservoir area to wage protracted struggle against poverty and to carry out sustainable development strategy for its long-term development. For practising the strategy, it is necessary to lay stress on its infrastructural construction; meanwhile it should make up an optimal composition for distributing fund, allocating enterprises and choosing ownerships. It is also necessary to make strenuous efforts to promote the tertiary sector. In short, it can not catch with the development level of the country average unless exerting several decades efforts.