Extreme rainfall trends of 21 typical urban areas in China during 1998-2015 based on remotely sensed data sets.

With the increase of population, many cities are growing in size at a phenomenal rate. Urbanization changes the urban underlying surface, influences the micro-climate, and sometimes affects the local precipitation process. In this study, we investigated the trends of extreme rainfall in China's 21 typical urban areas. Based on a series of daily rainfall and "Urban/built-up" dataset from TMPA 3B42 and MCD12Q1 products in China, trends in extreme precipitation, with the threshold defined as 95th (pre95p) and 99th (pre99p) percentiles of annual rain days during 1998-2015, have been assessed in China, and especially in 21 typical urban areas from 1998 to 2015. The tendency curves in extreme rainfall of different years are presented. In this period, more than 66% regions of China covered by TMPA 3B42 have increasing trends in extreme rainfall with pre95p threshold. The 21 typical urban areas showed different trends-in over half of these areas, upward tendencies in extreme rainfall were observed, particularly in Dalian, Beijing, and Chongqing. Seventeen urban areas showed increasing tendencies in pre95p extreme rainfall days, including Shanghai, Nanjing, Hangzhou, and Suzhou in the Yangtze River Delta region. The results also illustrate that southeastern coastal urban areas of China may have experienced decreasing occurrences in extreme rainfall.

[Expression of HOXC4 gene during early development in zebrafish].

OBJECTIVE: To investigate the mechanism of HOXC4 gene during early development in zebrafish, study it's expression in hematopoiesis system with whole mount in situ hybridization (WISH), then make a foundation work for further study of HOXC4 gene in hematopoiesis development. METHODS: The total RNA of different phases of zebrafish embryos was extracted, and a fragment of HOXC4 gene was cloned with RT-PCR, then HOXC4 gene fragment and pCS2 was digested with BamH I and Xho I restriction enzyme, after that HOXC4 gene fragment was inserted into pCS2+ vector. After confirming the constructed plasmid, the digoxingenin-labeled anti-sence mRNA probe of HOXC4 gene was synthesized in vitro by using T3 RNA polymerase, the exprression pattern of HOXC4 during zebrafish embryogenesis using anti-sence probe with WISH was conducted. RESULTS: HOXC4 gene was cloned by RT-PCR and HOXC4-pCS2+ plasmid was constructed and confirmed, expression of HOXC4 showed that it was expressed highly in nervous system of wild-type (WT) Tuebingen zebrafish. CONCLUSION: The expression pattern of HOXC4 during early development in zebrafish was obtained, and it is very important for further study of HOXC4 gene function in zebrafish.

[Expression pattern of hoxd3 gene during early development of wild-type zebrafish embryos].

OBJECTIVE: To investigate the expression pattern of hoxd3 gene during early embryogenesis and angiogenesis of wild-type zebrafish. METHODS: Total RNA was extracted from embryos of zebrafish in different development stages by trizol. The cDNA of hoxd3 gene was amplified by RT-PCR. The RT-PCR product was ligated to pCS(2+) vector by T4 DNA ligatase polymerase and sequenced. T3 RNA polymerase in vitro transcription system was used to obtain the probe of digoxin-labeled anti-sense mRNA of hoxd3 gene. The expression pattern of hoxd3 was detected by whole embryo in situ hybridization (WISH) with anti-sense mRNA probe. RESULTS: pCS(2+)-hoxd3 plasmid was successfully constructed, which was used to prepare anti-sense mRNA probe of hoxd3 in vitro. Expression pattern of hoxd3 gene was detected by WISH during zebrafish early embryogenesis and angiogenesis. It was observed that hoxd3 mRNA was expressed at the junction region of midbrain and hindbrain in wild-type zebrafish in embryos at 24 ≊72h postfertilization(hpf). CONCLUSION: hoxd3 gene is mainly expressed in nervous system of wide-type zebrafish embryos.