Based on in situ water sampling and field spectral measurement from June to September 2004 in Lake Chagan, a comparison of several existing semi-empirical algorithms to determine chlorophyll-a (Chl-a) content was made by applying them to the field spectra and in situ chlorophyll measurements. Results indicated that the first derivative of reflectance was well correlated with Chl-a. The highest correlation between the first derivative and Chl-a was at 680 nm. The two-band model, NIR/red ratio of R(710/670), was also an effective predictor of Chl-a concentration. Since the two-band ratios model is a special case of the three-band model developed recently, three-band model in Lake Chagan showed a higher resolution. The new algorithm named reverse continuum removal relies on the reflectance peak at 700 nm whose shape and position depend strongly upon chlorophyll concentration: The depth and area of the peak above a baseline showed a linear relationship to Chl-a concentration. All of the algorithms mentioned proved to be of value and can be used to predict Chl-a concentration. Best results were obtained by using the algorithms of the first derivative, which yielded R (2) around 0.74 and RMSE around 6.39 mug/l. The two-band and three-band algorithms were further applied to MERIS when filed spectral were resampled with regard to their center wavelengths. Both algorithms showed an adequate precision, and the differences on the outcome were small with R (2)= 0.70 and 0.71.

OBJECTIVE: To evaluate the feasibility and clinical significance of the computed tomography angiography (CTA) for the latissimus dorsi muscle (LDM) flap transplantation. METHODS: From September 2007 to August 2008, 3 cases of soft tissue defects in limbs were treated with LDM flap transplantation. Three patients included 2 males and 1 female who were 23- to 42-years-old. All of soft tissue defects were caused by trauma. The locations were the forearm in 2 cases and the leg in 1 case. The area of defect was 17 cm x 8 cm-20 cm x 10 cm. All cases received CTA to observe the distribution and anastomosis of thoracodorsal artery. Subsequently, three-dimensional computer reconstruction were carried out to display the stereoscopic structure of the LDM flap and to design the LDM flap before operation. RESULTS: The anatomy characteristic of LDM flap can be displayed accurately by the three-dimensional reconstruction model. The distribution of thoracodorsal artery in 3 cases of flaps was in concordance with preoperative design completely. All the flaps were excised successfully, the area of the flap was 19 cm x 10 cm-22 cm x 12 cm. All the transferred flaps survived completely. All cases were followed up from 4 months to 12 months. The color and texture of the flaps were good. CONCLUSION: The three-dimensional reconstructive images can provide visible, stereoscopic and dynamic anatomy for clinical application of LDM flap. The digitized three-dimensional reconstructive models of LDM flap structures can be applied in clinical training and pre-operative design.

This paper presents a novel method for estimating black-soil organic matter (SOM) in the black-soil zone of northeast China from hyperspectral reflectance models. Traditional black-soil property measurements are relatively slow, but the pressures of agricultural production and environmental protection require a quick method to collect black-soil organic matter content. SOM estimation using soil hyperspectral reflectance models can meet this requirement, based on the spectral characteristics of black-soil in Northeast China. On the basis of the spectral reflectance and its derivatives, hyperspectral models can be built using correlation analysis and multivariable statistical methods. The concepts of curvature and ratio indices are also applied to compare and test the stability and accuracy of data modeling. The results show that the response of black-soil spectral reflectance from 400-1,100 nm to organic matter content is more marked than that from 1,100-2,500 nm. Specifically, the main response range of black-soil organic matter is between 620-810 nm, with a maximal spectral response at 710 nm. By comparing different models, we found that the normalized first derivate model is optimal for estimating SOM content, with a determination coefficient of 0.93 and root mean squared errors (RMSE) of 0.18%.

The aim of this study was to investigate the genetic variation of HIV-1 CRF07_BC, the most prevalent circulating strain in intravenous drug users (IDUs) in China. We studied the diversity in the C2-V5 region of the HIV-1 env gene and in the p17-p24 region of the HIV-1 gag gene from the same samples in 12 IDUs who were divided into two groups according to the length of infection time. Two IDUs were longitudinally monitored from the time of seroconversion for 2-2.5 years. The viral divergence from the founder strain and the viral population diversity between sequential time points were analyzed in two men. The data show that the divergence of the env gene is higher than that of gag in general, while the diversity of the gag gene is sometimes higher than that of env during the course of HIV evolution. In addition, env and gag gene diversity increased over time. The observed patterns and associations may enhance our understanding of HIV-1 evolution.

OBJECTIVE: To identify the human hair basic kerat in 6 gene (hHB6) gene mutation in a mother and her daughter with monilethrix. METHODS: Clinical data were obtained by investigating the pedigree and examining the patients' hair and skin. Total genomic DNA of the family participants was isolated. All exons and exon-intron boundaries of hHB6 were amplified by PCR. Mutation screening was carried out using direct DNA sequencing. Restriction fragment length polymorphism (RFLP) analysis was used to confirm the mutation, and to investigate if the mutation co-segregated with the disease in the family and existed in normal controls. RESULTS: A heterozygous transition of c.1204G to A (p.E402K) of hHB6 was identified. RFLP analysis demonstrated that affected members carried the p.E402K mutation, but the unaffected members of the family and 150 unrelated normal Chinese Han nationality controls did not carry the mutation. CONCLUSION: This study identified the hHB6 gene mutation c.1204G to A (p.E402K) in a Chinese monilethrix family. The mutation was inherited from the mother to her daughter. The results emphasized the key role of hair keratin hHB6 in the pathogenesis of monilethrix and indicated that the common mutation of hHB6 was also a cause of monilethrix in Chinese.

In recent years, much attention has been given to desertification in Xinjiang, China, particularly in the southern edge of the Taklimakan Desert. In this study, an oasis in Minfeng County, which is located in the southern edges of the Taklimakan Desert, was chosen as our case study area. Supervised classification for land types was conducted, and then the change detection and the trend of changes in sandy land areas were analyzed and compared. The results show that the area of sandy land has decreased in the region in the period of 1992-2001. The main change was between sandy land and sparse vegetation in the Desert-oasis ecotone. In addition, the change from woodland to grassland and/or arable land was quite obvious from 1992 to 2001. These changes would probably result in more fragile environment and higher potentiality in land desertification in the area.

Objective To assess differences of HIV risk between ethnicities in northwestern China. Method Cross-sectional serosurvey and structured questionnaire interview of 383 injection drug users of either Han or Uigur ethnicity in Urumqi, Xinjiang. Results Both Uigur minority ethnicity and residence in a Uigur or mixed Uigur/Han community were independently associated with higher HIV risk. Conclusion HIV prevention programs should give special focus on minority ethnic drug users and their communities.

To investigate more closely the determinants of transmission and escape in HIV-1 internal proteins, we analyzed the characterization of putative N-linked glycosylation sites (PNGSs) and the variable loop of CRF07_BC recombinant human immunodeficiency virus type 1 (HIV-1), isolated from intravenous drug users (IDUs). We studied the characterization of PNGSs and the variable loop in the C1-C5 and V1-V4 regions of the HIV-1 env gene in 12 intravenous drug users (IDUs) who were divided into two groups according to the length of infection time. In addition, two IDUs were longitudinally monitored from the time of seroconversion for 1.5 and 2.5 years. The longitudinal characterization within the individuals on PNGSs and the variable loop in the C1-C5 and V1-V4 region were also observed. Based on the above analysis, we found that PNGSs and the variable loop appeared to increase over time within IDU transmission of CRF07_BC recombinant HIV-1. We argue that limited PNGSs and the length of variable loops may be involved in selective transmission and escape.

The objective of this study is to develop techniques for assessing and analysing land desertification in Yulin of Northwest China, as a typical monitoring region through the use of remotely sensed data and geographic information systems (GIS). The methodology included the use of Landsat TM data from 1987, 1996 and 2006, supplemented by aerial photos in 1960, topographic maps, field work and use of other existing data. From this, land cover, the Normalised Difference Vegetation Index (NDVI), farmland, woodland and grassland maps at 1:100,000 were prepared for land desertification monitoring in the area. In the study, all data was entered into a GIS using ILWIS software to perform land desertification monitoring. The results indicate that land desertification in the area has been developing rapidly during the past 40 years. Although land desertification has to some extent been controlled in the area by planting grasses and trees, the issue of land desertification is still serious. The study also demonstrates an example of why the integration of remote sensing with GIS is critical for the monitoring of environmental changes in arid and semi-arid regions, e.g. in land desertification monitoring in the Yulin pilot area. However, land desertification monitoring using remote sensing and GIS still needs to be continued and also refined for the purpose of long-term monitoring and the management of fragile ecosystems in the area.

BACKGROUND: Chinese injection drug users (IDUs) may be a proper candidate population for HIV vaccine trials. OBJECTIVE: To evaluate willingness to participate (WTP) in HIV vaccine trials among Chinese IDUs. METHODS: Questionnaire interviews were completed among 401 IDUs in Urumqi City in northwestern China in 2005. RESULTS: Overall 74.3% of participants said that they would be definitely willing to participate in HIV vaccine trials, 17.7% were probably willing, 6.2% were probably not willing, and remaining 1.8% were definitely not willing to join. Multivariate logistic regression analysis demonstrated that WTP was positively associated with having ever had sex with a drug use partner (adjusted odds ratio [AOR]: 1.8; 95% confidence interval [CI]: 1.04, 3.2), sharing needle and syringe with a new drug use partner in the past 3 months (AOR: 3.8; 95% CI: 1.2, 11.7), perceived family support for participation (AOR: 7.4; 95% CI: 4.3, 12.7), and perceived vaccine protection against HIV infection (AOR: 16.1; 95% CI: 3.7, 70.8), and was negatively associated with perceived risk of social stigma and isolation for participation (AOR: 0.3; 95% CI: 0.2, 0.5). CONCLUSIONS: The stated WTP in hypothetical HIV vaccine trials was high among Chinese IDUs. Further studies are needed to evaluate actual enrollment into the trials.

From August 2004 to August 2005, three replicated experimental platforms were constructed in a section of tidal flat in Yingluo Bay of Guangxi to study the growth and physiological responses of Rhizophora stylosa Griff seedlings to the waterlogging stress of tide in diurnal tide zone. A total of eight tidal flat elevation (TFE) treatments, i. e., 320 cm, 330 cm, 340 cm, 350 cm, 360 cm, 370 cm, 380 cm and 390 cm above Yellow Sea Datum (YSD), were created on each platform. The results showed that lower TFEs (320-330 cm YSD) slightly increased the stem height of 1-year old seedlings, while higher TFFs (> 340 cm YSD) increased the seedlings growth significantly. Moderate TFEs (350-370 cm YSD) favored the development of knots. Leaf number, leaf conservation rate, and leaf area per seedling all decreased dramatically with decreasing TFE. Lower TFEs had a larger damage to Chl a, but Chl b was less affected. The Chl a/b ratio decreased with decreasing TFE. Prolonged waterlogging induced a higher SOD activity in root, while moderate TFE inhibited the SOD activity in leaf. The POD activity in root and leaf increased with decreasing TFE. Waterlogging stress decreased the biomass of individual organs and whole seedling. With increasing waterlogging, the biomass partitioning in 1-year old seedlings increased from leaf to stem. The survival rate decreased sharply from 88.9% to 40.0% as TFE decreased, while more than 80% of the seedlings could survive at the TFE being 370 cm YSD and above. It was proposed that the local mean sea level could be adopted as the critical tidal level for the forestation with hypocotyls of R. stylosa along the Guangxi coast.

Semarang coastal area has geomorphologically complex processes, such as erosion-sedimentation, land subsidence, and tidal inundation hazard. Multi-years shoreline mapping is considered a valuable task for coastal monitoring and assessment. This paper presents maps illustrating the shoreline dynamic in a coastal area of Semarang-Indonesia using multi-sources spatial data. The segment data has been obtained by visual delineation of the topographic maps Year 1908, 1937, 1992 and Ikonos image Year 2003 as well as digital number (DN) value analysis and masking operation of Landsat MSS Year 1972 and Landsat ETM Year 2001. For the long period of almost 100 year, the shoreline dynamic in Semarang coastal area is dominated by sedimentation process. Shoreline extended to the sea as a result of man-made infrastructure and natural processes. The research's result was satisfactory and the method has proven to be effective considering lack of homogeneous data-series. However, some further improvement regarding geo-processing can be made and the accuracy can be tested in future version.