A description of the first intact Dwarf Sperm whale from the South China Sea and a review of documented specimens of the Kogiidae (Cetacea) from Hong Kong

Reports of the Dwarf Sperm whale (Kogia sima) in Chinese waters exist only for four specimens, which stranded along the coast of the East China Sea. Records of this species in the South China Sea consist of one skull noted as present in a Vietnamese ‘whale temple’. Recently recognized material in the biological sciences building of the University of Hong Kong, confirms the presence of both the Dwarf (K. sima) and the Pygmy (K. breviceps) Sperm whales in Hong Kong. In addition, close examination of Hong Kong stranding records reveals that of the four specimens identified as K. breviceps one is, in fact, K. sima. A comparison of the Hong Kong material, the holotype of K. sima and other Asian specimens of Kogia spp. affirms that most of the features already used elsewhere to distinguish the two species are reliable.     

Reefs of tomorrow: eutrophication reduces coral biodiversity in an urbanized seascape

Although the impacts of nutrient pollution on coral reefs are well known, surprisingly, no statistical relationships have ever been established between water quality parameters, coral biodiversity and coral cover. Hong Kong provides a unique opportunity to assess this relationship. Here, coastal waters have been monitored monthly since 1986, at 76 stations, providing a highly spatially resolved water quality dataset including 68 903 data points. Moreover, a robust coral species richness (S) dataset is available from more than 100 surveyed locations, composed of 3453 individual colonies' observations, as well as a coral cover (CC) dataset including 85 sites. This wealth of data provides a unique opportunity to test the hypothesis that water quality, and in particular nutrients, drives coral biodiversity. The influence of water quality on S and CC was analyzed using GIS and multiple regression modeling. Eutrophication (as chlorophyll‐a concentration; CHLA) was negatively correlated with S and CC, whereas physicochemical parameters (DO and salinity) had no significant effect. The modeling further illustrated that particulate suspended matter, dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) had a negative effect on S and on CC; however, the effect of nutrients was 1.5‐fold to twofold greater. The highest S and CC occurred where CHLA <2 μg L^?1, DIN < 2 μm and DIP < 0.1 μm . Where these values were exceeded, S and CC were significantly lower and no live corals were observed where CHLA > 15 μg L^?1, DIN > 9 μm and DIP > 0.33 μm . This study demonstrates the importance of nutrients over other water quality parameters in coral biodiversity loss and highlights the key role of eutrophication in shaping coastal coral reef ecosystems. This work also provides ecological thresholds that may be useful for water quality guidelines and nutrient mitigation policies.     

丹红注射液治疗膝关节置换术后患者的临床疗效及机制研究

目的:探讨丹红注射液治疗膝关节置换术后患者的临床疗效、安全性及其可能作用机制。方法:选取我院骨科收治的行膝关节置换术的患者86例,根据就诊顺序平均分为两组,对照组43例予以术后常规治疗,实验组43例予以丹红注射液治疗。治疗后,观察并比较两组患者的临床疗效,血清IL-6、IL-8及TNF-α水平的变化,并发症的发生情况以及膝关节功能的活动情况。结果:与对照组相比较,实验组的总有效率及HSS评分更高(P0.05),血清IL-6、IL-8、TNF-α的水平,感染和粘连的发生率较低(P0.05)。结论:丹红注射液能够提高膝关节置换术的临床疗效,减少并发症的发生,使患者的膝关节功能尽快恢复,这可能与其降低血清IL-6、IL-8及TNF-α水平有关。     

‘Playing’ at the ethnic boundary: strategic boundary making/unmaking among ethnic Chinese groups in Australia

The sociological literature has constructed a systematic typology of ‘modes’ and ‘means’ of strategic ethnic boundary making/unmaking. Through exploring different strategies, scholars illustrate the processes and contexts of boundary expansion or contraction. Other scholars also distinguish ethnic elements and ‘moral' values attached to certain ethnicities but not to others. This paper acknowledges dynamic boundary making/unmaking and moral aspects of ethnicity, while exploring the different degrees to which national and pan-national identity nest within each other among ethnic Chinese groups, as well as how ethnic boundary becomes a field where people ‘play' in their everyday interactions. Based on participant observations and in-depth interviews from two pan-Chinese worksites in Australia, the paper argues that different interpretations of ethnic identity as well as how different identities (national and pan-national) are nested give people room to ‘play' at the ethnic boundary and result in different outcomes. This paper also shows that people can cross the ethnic boundary (between Taiwanese/Hong Kongese and PRC-Chinese) without expanding/contracting the existing categories or ‘repositioning/transvaluing' their ethnic statuses.     

Phenology of Sargassum spp. in Tung Ping Chau Marine Park, Hong Kong SAR, China

Eight species of the brown alga Sargassum have been recorded from Tung Ping Chau Marine Park in Hong Kong and the phenology of four of these was monitored from 1996 to 2000. All four species followed a typical growth cycle of Sargassum species reported elsewhere but with some annual variations. For S. hemiphyllum, the maximum mean (±SD) plant length, ranging from 38.5 ± 10.5 to 61.9 ± 19.9 cm, was recorded in January to March. The peak reproductive season was also mainly in February to March with up to 89% of the plants being reproductive. Some plants, however, remained reproductive until May. For. S. henslowianum, the maximum mean plant length, ranging from 45.5 ± 25.5 to 77 ± 24.8 cm, was recorded mainly in November to January. The peak reproductive season was in November to February with up to 100% of the plants being reproductive. For S. siliquastrum, the maximum mean plant length, ranging from 48.2 ± 29.9 to 63.4 ± 22.1 cm, was also recorded mainly in January. The reproductive plants were found mainly between late December and mid February with up to 98% of the plants being reproductive. For. S. patens, the maximum mean plant length ranging from 87.6 ± 62.4 to 118.7 ± 41.3 cm was recorded in January to March. Reproduction of this species was not monitored. Changes in water temperature over seasons were likely to be critical in affecting the phenological patterns of these species.     

Morphology and Molecular Phylogeny of a New Marine Hypotrichous Ciliate,Hypotrichidium paraconicum n. sp. (Ciliophora,Hypotrichia)

A new saline hypotrich, Hypotrichidium paraconicum n. sp., found in coastal waters near Hong Kong, China, was investigated with emphasis on its living morphology, infraciliature, ontogenesis, and phylogenetic position. A body that is pyriform, with a posterior end that is twisted helically toward the left, a distinct tail and a dark colour, characterizes H. paraconicum n. sp. The buccal cavity is prominent and the cortical granules, which are scattered or sparsely distributed, are colourless, round, and about 1 μm in diam. The contractile vacuole is near the left middle of the cell and there are one or two frontal cirri, four meridional rows and five or six cirral rows which exhibit a left‐handed spiral and which are distributed in the posterior portion on both sides. Three dorsal kineties are distributed in the anterior portion of the dorsal side. In our molecular phylogenies, based on SSU rRNA gene sequences, the position of H. paraconicum n. sp. is rather poorly resolved, providing some indication of a relationship with Neokeronopsis aurea and Rubrioxytricha ferruginea, which fall into the assemblage of oxytrichids (s.l.).     

Palynological record of climate change during the last deglaciation from the Song Hong (Red River) delta, Vietnam

The palynological sequence from core ND-1 on the Song Hong delta in the northern Vietnam reveals the climate change during the last deglaciation. The identified pollen in the core is dominated by Castanopsis (Lithocarpus), Elaeocarpus, Ficus, Piperaceae and Quercus. High percentages of temperate taxa including the conifers Dacrydium, Podocarpus, Pinus, Cupressaceae, Txodiaceae and Cryptomeria, and broad-leaved taxa of Carpinus, Alnus, Juglans, Carya, Ulmus, Fagus, Ilex, Castanea, Quercus, which have a mainly upland distribution, is possibly associated with a lowering of the montane vegetation boundary. On the other hand, intensified river influence can also result in an increase in the temperate allochthonous taxa. After analyzing the magnitude of river influence on pollen assemblages during the sedimentary environment evolution, we extracted the climate information and used this to reconstruct climate change during the last deglaciation. A cooler climate during 14.5-10.9 cal. kyr BP than at present is indicated by higher percentage of temperate types than at present under a similar river influence on the floodplain. The Younger Dryas cooling event is recognized by widely developed grasslands between 12.9 and 11.6 cal. kyr BP, adding to the evidences for this period from both terrestrial and marine records in regions influenced by the East Asian monsoon. Two other cooling periods, 9.4-9.0 cal. kyr BP and 6.5-5.2 cal. kyr BP, are indicated by increases of temperate pollen taxa such as Cryptomeria, Alnus, Quercus, and Castanea.     

Nonselective Suppression of Voltage-gated Currents by Odorants in the Newt Olfactory Receptor Cells

Effects of odorants on voltage-gated ionic channels were investigated in isolated newt olfactory receptor cells by using the whole cell version of the patch–clamp technique. Under voltage clamp, membrane depolarization to voltages between −90 mV and +40 mV from a holding potential (V_h) of −100 mV generated time- and voltage-dependent current responses; a rapidly (< 15 ms) decaying initial inward current and a late outward current. When odorants (1 mM amyl acetate, 1 mM acetophenone, and 1 mM limonene) were applied to the recorded cell, the voltage-gated currents were significantly reduced. The dose-suppression relations of amyl acetate for individual current components (Na⁺ current: I_Na, T-type Ca²⁺ current: I_Ca,T, L-type Ca²⁺ current: I_Ca,L, delayed rectifier K⁺ current: I_Kv and Ca²⁺-activated K⁺ current: I_K(Ca)) could be fitted by the Hill equation. Half-blocking concentrations for each current were 0.11 mM (I_Na), 0.15 mM (I_Ca,T), 0.14 mM (I_Ca,L), 1.7 mM (I_Kv), and 0.17 mM (I_K(Ca)), and Hill coefficient was 1.4 (I_Na), 1.0 (I_Ca,T), 1.1 (I_Ca,L), 1.0 (I_Kv), and 1.1 (I_K(Ca)), suggesting that the inward current is affected more strongly than the outward current. The activation curve of I_Na was not changed significantly by amyl acetate, while the inactivation curve was shifted to negative voltages; half-activation voltages were −53 mV at control, −66 mV at 0.01 mM, and −84 mV at 0.1 mM. These phenomena are similar to the suppressive effects of local anesthetics (lidocaine and benzocaine) on I_Na in various preparations, suggesting that both types of suppression are caused by the same mechanism. The nonselective blockage of ionic channels observed here is consistent with the previous notion that the suppression of the transduction current by odorants is due to the direst blockage of transduction channels.     

Differentiation of Secondary Spermatogonia to Primary Spermatocytes by Mammalian Follicle-Stimulating Hormone in Organ Culture of Testes Fragments from the Newt, Cynops pyrrhogaster

In order to elucidate essential factors responsible for the initiation and promotion of spermatogenesis, we developed an organ culture system with a chemically defined medium. When newt testes fragments, consisting of somatic cells and germ cells almost exclusively secondary spermatogonia, were cultured in control medium for three weeks, most of the testicular cysts still contained only secondary spermatogonia. On the other hand, in the medium supplemented with various kinds of hormones and vitamins primary spermatocytes (zygotene-pachytene) appeared in about 60% of the cysts by the second week. Selective removal of specific hormones and vitamins revealed that follicle-stimulating hormone (FSH) alone was indispensable and sufficient for the differentiation of secondary spermatogonia to primary spermatocytes. Neither the addition of luteinizing hormone (LH) nor androgens (testosterone and 5α-dihydrotestosterone) to the control medium stimulated differentiation. Consistent with these findings was the fact that radioreceptor assays revealed high affinity specific binding sites for FSH but none for LH. Since our ultrastructural studies revealed a major loss of contact between spermatogonia and Sertoli cells following exposure to FSH, we suggest that FSH triggers differentiation of spermatogonia by acting on Sertoli cells which in turn act on spermatogonia.