The life history of Brotia hainanensis (Brot, 1872) (Gastropoda: Prosobranchia: Thiaridae) in a tropical forest stream

An investigation of the prosobranch snail Brotia hainanensis (Brot, 1872) (Gastropoda: Thiaridae) in Tai Po Kau Forest Stream, New Territories, Hong Kong, has been undertaken with population samples collected at approximately 14-day intervals between August, 1977 and March, 1979. This species shows two peaks of recruitment per annum, one in spring and a second in the latter part of summer. Growth to sexual maturity is rapid, taking approximately 8.5 months, and in this respect, as well as its dual peak of recruitment, B. hainanensis displayed some variation from the iteroparous pattern of life cycles considered to be characteristic of freshwater prosobranch snails. Mortality after the young snails reach maturity is high due to severe seasonal spates in the stream and it is suggested that the modification of the life cycle of B. hainanensis from the type more usually encountered in freshwater prosobranchs reflects that this is an r-selected species adapted to a habitat where high density-independent mortality occurs.     

Selection of Stable Reference Genes for Quantitative Real-Time PCR on <i>Paeonia ostii</i> T. Hong et J. X. Zhang Leaves Exposed to Different Drought Stress Conditions

The definition of relatively stable expressed internal reference genes is essential in both traditional blotting quantification and as a modern data quantitative strategy. Appropriate internal reference genes can accurately standardize the expression abundance of target genes to avoid serious experimental errors. In this study, the expression profiles of ten candidate genes, ACT1, ACT2, GAPDH, eIF1, eIF2, α-TUB, β-TUB, TBP, RNA Pol II and RP II, were calculated for a suitable reference gene selection in Paeonia ostii T. Hong et J. X. Zhang leaves under various drought stress conditions. Data were processed by the four regularly used evaluation software. A comprehensive analysis revealed that RNA Pol II was the most stable gene and eIF2 was the least stable one. In addition, the geNorm program provided the optimal choice of two reference gene combination, RNA Pol II and β-TUB, for qRT-PCR normalization in P. ostii subjected to different drought stress levels. Our research provided convenience for gene expression analysis in P. ostii under drought stress and promoted research of effective methods to alleviate P. ostii drought stress in the future.     

康惠尔水胶体透明贴对阿奇霉素引起的静脉炎的预防作用

目的:观察康惠尔水胶体透明贴对使用阿奇霉素引起的静脉炎的疗效与效果。方法:从我院2009年1月-2010年1月的呼吸内科患者中选择100例使用阿奇霉素静脉输液治疗的患者。分为观察组与对照组,每组50名使用阿奇霉素静脉输液治疗的患者。普通组使用普通透明贴,对照组患者使用康惠尔水胶体透明贴。对两组患者进行比对。结果:观察组的50名患者使用普通透明贴,16例未发生静脉炎,发生静脉炎为34例;对照组的50名患者使用康惠尔水胶体透明贴,仅有2例发生静脉炎的患者。对照组与普通组相比,对照组结果好于普通组,P<0.05差距有显著统计学意义。结论:使用康惠尔水胶体透明贴可以有效的减少呼吸内科患者使用阿奇霉素造成的静脉炎发生率。     

香港茜草科植物新记录

查阅馆藏植物标本,有3种茜草科植物：丹草（Hedyotis herbacea）、小耳草（H.pumila）和蕴璋耳草（Scleromitrion koanum）为香港新记录。这些资料为香港的生物多样性工作提供了基础数据。     

Clarithromycin–Amoxycillin‐Containing Triple Therapy: A Valid Empirical First‐Line Treatment for Helicobacter pylori Eradication in Hong Kong?

Background: Recent studies have suggested the eradication rate for Helicobacter pylori infection with standard amoxycillin–clarithromycin‐containing triple therapy as first‐line treatment have fallen below 80%. Levofloxacin‐containing triple therapy was proposed as an alternative. The aim of this study is to compare the efficacy and tolerability of the standard 7‐day clarithromycin‐containing triple therapy against the 7‐day levofloxacin‐containing triple therapy, and to assess whether the classical triple therapy is still valid as empirical first‐line treatment for H. pylori infection in Hong Kong. Methods: Three hundred consecutive H. pylori‐positive patients were randomized to receive either 1 week of EAL (esomeprazole 20 mg b.d., amoxycillin 1 g b.d., and levofloxacin 500 mg daily) or EAC (esomeprazole 20 mg b.d., amoxycillin 1 g b.d., and clarithromycin 500 mg b.d.). H. pylori status was rechecked by ¹³C‐urea breath test 6 weeks after treatment. Patients who failed either of the first‐line eradication therapy were invited to undergo H. pylori susceptibility testing. Results: H. pylori eradication was achieved in 128 of 150 (85.3%) patients in EAL and 139 of 150 (92.7%) patients in EAC groups, respectively (p = .043), for both intention‐to‐treat and per‐protocol analysis. More patients in the clarithromycin‐ than the levofloxacin‐containing therapy group developed side effects from the medication (21.3% vs 13.3%, p = .060). Nine patients (six from the EAL group and three from the EAC group) who failed their corresponding eradication therapy returned for susceptibility testing. All nine isolates were highly resistant to levofloxacin (minimum inhibitory concentration or MIC > 32 μg/mL), whereas only two of the six isolates from the EAL group were resistant to clarithromycin (MIC > 0.5 μg/mL). Conclusions: The standard 7‐day clarithromycin‐containing triple therapy is still valid as the most effective empirical first‐line eradication therapy for H. pylori infection in Hong Kong, as prevalence of primary resistance of H. pylori to amoxycillin and clarithromycin remains low. Patients who failed their empirical first‐line eradication therapy should undergo H. pylori susceptibility testing to guide further treatment.     

Substrate Availability May Be More Important than Aquatic Insect Abundance in the Distribution of Riparian Orb-web Spiders in the Tropics

Spiders that are abundant along streams may depend on energy subsidies across land–water ecotones, but the effects of season and habitat structure on this trophic linkage remain poorly understood in the tropics. We carried out surveys and a manipulative experiment to investigate the effects of season and substrate availability on the distribution of riparian orb-web spiders in Hong Kong, southern China. In the surveys, spider abundance, prey, substrate use, and web orientation were recorded. The experiment involved installation of in-stream artificial substrates (ropes and bamboo poles) to increase substrate availability for web attachment. We found no seasonal difference in web abundance, but seasonal differences were observed for the prey on webs: aquatic insects (mostly Ephemeroptera and chironomid midges) contributed 69 percent of total prey collected during the wet season, but only 38 percent during the dry season. Most webs (50–80%) were < 0.5 m above the water and 45–51 percent of them tended to be orientated horizontally to the water surface and supported by overhanging vegetation and boulders. The addition of artificial substrates resulted in a 23–34 percent increase in the number of webs at the four treatment sites compared to controls, indicating that availability of web-building substrates is a critical determinant of the spider distribution. Our results suggest that riparian zones are potential 'hotspots' of food availability for spiders, and that the aquatic insect subsidy allows this habitat to support increased densities of spiders when the constraint of substrate availability is relaxed.     

Plant Biodiversity in China: Richly Varied, Endangered, and in Need of Conservation

China is among the world's richest countries in terms of plant biodiversity. Besides the abundant flora, containing some 33,000 vascular plants (30,000 angiosperms, 250 gymnosperms, and 2600 pteridophytes), there is extraordinary ecosystem diversity, as well as a large pool of both wild and cultivated germplasms. China is also considered one of the main centers of origin and diversification for seed plants on Earth, and is especially profuse in phylogenetically primitive taxa and/or paleoendemics due to the refuge role glaciation played during the Quaternary period. The collision with the Indian subcontinent significantly enriched Chinese flora and led to the formation of many neoendemisms. However, flora distribution remains uneven, and some local floristic hotspots are found across China, such as Yunnan, Sichuan and Taiwan. Unfortunately, this biodiversity faces enormous threats, which have increased substantially over the last 50 years. The combined effects of habitat destruction and/or fragmentation, environmental contamination, over-exploitation of natural resources, and to a lesser extent, introduction of exotic species, have caused irreparable damage to China's plant biodiversity. Burgeoning economic and population growth have also contributed to this deterioration. It is believed that up to 5000 flora species are currently endangered in China, with some taxa having already become extinct. Although in recent years government authorities have made some efforts to preserve biodiversity, much work remains to be done. While China has established an extensive network of nature reserves and protected areas, encompassing more than 16% of the total land area, insufficient budgetary and staffing commitments are common limitations in their management structures. Ex-situ conservation is also deficient, primarily because the botanical gardens are not representative of several local floras, nor are they often of adequate size or representative of endangered species. The lack of effective and efficient environmental legislation and education are also problems that continue to accelerate the loss of plant biodiversity in China.     

防洪改善计划对鸟类的生态影响

香港特别行政区新界内有23 hm^2的鱼塘和22 hm^2的耕地,在“元朗-锦田-牛潭尾主要防洪改善计划”中被改变成两条防洪渠（防洪渠60号和43号）.于该防洪改善计划中的生态监察调查中发现这两条防洪渠的鸟类数量均较原先的生境大大减少.在耕地改变成防洪渠43号的过程中,鸟类密度由33.9 只/hm^2减少至2.2只/hm^2.在鱼塘改变成防洪渠60号的过程中,鸟类密度由5.2 只/hm^2 减少至0.4只/hm^2.研究亦发现一些原本在鱼塘和耕地很常见的鸟类物种因为生境被改变而消失.这些转变可能和食物,植被及生境复杂程度的减少有关.另一方面,为纾缓因这防洪改善计划中损失的耕地生境,渠务署在防洪渠43号的河岸铺上混凝土草格,促进植物繁衍,为鸟类提供生境.但研究发现以混凝土草格建造的草坡并未能提供有效的纾缓措施,取代耕地生境以减少生态影响.     

Experimentally derived estimates of growth by juvenile Tachypleus tridentatus and Carcinoscorpius rotundicauda (Xiphosura) from nursery beaches in Hong Kong

Juvenile Tachypleus tridentatus and Carcinoscorpius rotundicauda with prosomal widths of between 17.1 and 91.1 mm were obtained from their nursery beaches in Hong Kong. They were kept in the laboratory and fed a mixture of squid, prawn and fish. Prosomal width and wet weight were measured weekly to obtain growth data. Over half of the individuals molted during a five and a half month captivity period. After every ecdysis, prosomal width and wet weight of T. tridentatus grew by averages of 24.2% and 71.5% over pre-molt measurements, respectively. Similar values were obtained for C. rotundicauda, i.e. 24.0% and 77.3%, respectively. Three T. tridentatus with prosomal widths of between 26.5 and 35.0 mm molted twice between 89 and 149 days, leading to an average growth rate of 0.1 mm·day⁻¹ and 0.04 g·day⁻¹ in terms of prosomal width and wet weight, respectively. A positive growth allometry (b coefficient=2.97) was identified, indicating that weight gain for T. tridentatus, and possibly C. rotundicauda, was faster than prosomal width growth after each ecdysis. The effect of temperature on growth was also determined by comparing the percentages of T. tridentatus which molted at ∼28 °C and ∼18 °C. Fifty percent of individuals molted at the former, but only 10% at the latter. This study indicates that Hong Kong horseshoe crabs take a shorter time to reach sexual maturity, as compared with conspecifics in Japan, because they can molt more frequently at higher sediment/water temperatures (∼28 °C) if food is available.     

A Comparison of Ship-Recycling Legislation Between Chinese Law and the 2009 Hong Kong Convention

This article discusses the Chinese legal framework in relation to ship recycling and suggests that the various legislation, standards, and opinions provide disorderly and nosystematic regulation. A uniform law specifically regulating the ship-recycling industry should be adopted by China, with a single competent authority empowered to supervise ship-recycling activities, that will effectively implement the 2009 Hong Kong International Convention for the Safe and Environmentally Sound Recycling of Ships.