Insularity and the determinants of lizard population density

The relative effects of resource availability and partitioning on animal population density are unresolved yet central to ecology and conservation. Species-depauperate islands offer an intriguing test case. Across 643 lizard populations from around the world, local abundances are one order of magnitude higher on islands than on mainlands, even when controlled for resource availability. On mainlands, predator and competitor richness only weakly correlate with lizard densities. On islands, sharp reductions in predator and competitor richness are the dominant drivers of lizard abundance. Our results demonstrate the dramatic effect insularity has on the interplay between biotic and abiotic control of animal abundances and the heightened sensitivity of island communities to species' losses and gains.     

Release method evaluation for swift fox reintroduction at Bad River Ranches in South Dakota

Reintroductions have increasingly become effective at restoring populations of imperiled native wildlife. How animals are reintroduced into unfamiliar environments may have pronounced impacts on behavior, survival, and reproduction. We evaluated the influence of four release methods on survival rates of translocated swift foxes at Bad River Ranches (BRR) in western South Dakota: (1) hard‐release, (2) short‐soft‐release, (3) long‐soft‐release, and (4) captive born. A total of 179 foxes captured in Wyoming during 2002–2007 and in Colorado during 2006–2007 were released into BRR and the surrounding area. In addition, 43 pups born to foxes in the long‐soft‐release category were also released. All release methods incorporated a 14‐ to 21‐day quarantine period. Hard‐release foxes were released directly from a transport kennel, whereas short‐soft‐release foxes were released from soft‐release pens by opening the door and allowing the foxes to leave voluntarily. Long‐soft‐release foxes were held for more than 250 days on‐site in soft‐release pens through the winter and released in the following year in early summer. During 2002–2007, survival of reintroduced foxes differed significantly (p < 0.05) by age (adult vs. juvenile), release year, and release method. The short‐soft‐release method had the highest 60‐day post‐release survival probability compared with the other release methods. We did not detect any differences in mortality hazards between wild‐born and short‐soft‐release foxes. Reintroduction programs based on short‐soft‐releases are useful for restoring or augmenting populations to advance the conservation of the swift fox.     

Botulinum neurotoxin type A modulates vesicular release of glutamate from satellite glial cells

This study investigated the presence of cell membrane docking proteins synaptosomal‐associated protein, 25 and 23 kD (SNAP‐25 and SNAP‐23) in satellite glial cells (SGCs) of rat trigeminal ganglion; whether cultured SGCs would release glutamate in a time‐ and calcium‐dependent manner following calcium‐ionophore ionomycin stimulation; and if botulinum neurotoxin type A (BoNTA), in a dose‐dependent manner, could block or decrease vesicular release of glutamate. SGCs were isolated from the trigeminal ganglia (TG) of adult Wistar rats and cultured for 7 days. The presence of SNAPs in TG sections and isolated SGCs were investigated using immunohistochemistry and immunocytochemistry, respectively. SGCs were stimulated with ionomycin (5 μM for 4, 8, 12 and 30 min.) to release glutamate. SGCs were then pre‐incubated with BoNTA (24 hrs with 0.1, 1, 10 and 100 pM) to investigate if BoNTA could potentially block ionomycin‐stimulated glutamate release. Glutamate concentrations were measured by ELISA. SNAP‐25 and SNAP‐23 were present in SGCs in TG sections and in cultured SGCs. Ionomycin significantly increased glutamate release from cultured SGCs 30 min. following the treatment (P < 0.001). BoNTA (100 pM) significantly decreased glutamate release (P < 0.01). Results from this study demonstrated that SGCs, when stimulated with ionomycin, released glutamate that was inhibited by BoNTA, possibly through cleavage of SNAP‐25 and/or SNAP‐23. These novel findings demonstrate the existence of vesicular glutamate release from SGCs, which could potentially play a role in the trigeminal sensory transmission. In addition, interaction of BoNTA with non‐neuronal cells at the level of TG suggests a potential analgesic mechanism of action of BoNTA.     

Terpene glucoside production: Improved biocatalytic processes using glycosyltransferases

Terpenoids are one of the main classes of natural products. In plants, a large fraction of the terpenoids is present as nonvolatile glycosides. The terpene glycosides have attracted much attention as antimicrobials, flavor precursors, and detergents. They are either extracted from plant materials or are synthesized by chemical and biocatalytic methods. Up to now, biotechnological production of terpene glycosides is based on reversed hydrolysis performed by glycosidases. However, this method suffers from low yields as a matter of principle. Recently, the first uridine diphosphate‐glucose:monoterpenol β‐d ‐glucosyltransferase (GT) genes were cloned and characterized from grapevine (Vitis vinifera) and kiwi (Actinidia deliciosa). Heterologous expression in Escherichia coli yielded promiscuous GT enzymes that efficiently glucosylated primary monoterpenols, simple alcohols, and phenols. The GT enzymes differed in substrate preference and activity toward their terpenoid substrates. Biotransformation experiments confirmed the applicability of the novel GTs in biocatalytic processes for the production of these novel compounds. In the near future, terpene glucosides will become commercially available for food, cosmetic, and pharmaceutical industry due to improved biocatalytic processes involving GT enzymes.     

武汉市65个园林树种的生态功能研究

园林树种是建设生态园林城市的主体,其生态功能的定量研究是园林植物筛选、配置和管理的重要依据.本研究通过测量武汉市65个常见园林树种的光合、蒸腾日变化及冠幅、叶面积指数等指标,发现树种间、乔木与灌木、常绿与落叶植物之间的水分利用、固碳释氧、蒸腾降温及滞尘能力均有显著差异.根据分层聚类分析,可将它们划分为5大功能类群.其中低固碳低滞尘型26种;高固碳高降温型8种(分别为垂柳Salix babylonica、火棘Pyracantha fortuneana、栾树Koelreuteria paniculata、木芙蓉Hibiscus mutabilis、枇杷Eriobotrya japonica、西府海棠Malus micromalus、银木Cinnamomum septentrionale和重阳木Bischofia javanica);高滞尘低降温型9种(分别为枫杨Pterocarya stenoptera、桂花Osmanthus fragrans、夹竹桃Nerium indicum、马褂木Liriodendron chinense、石楠Photinia serrulata、悬铃木Platanus hispanica、雪松Cedrus deodara、银杏Ginkgo biloba和樟树Cinnamomum camphora);低水分利用高蒸腾型11种;高水分利用型11种.     

Oral malignant melanoma--an unusual presentation

Malignant melanoma is the least common but most deadly of all primary skin cancers. Oral malignant melanoma is a rare aggressive neoplasm usually seen in middle aged persons. This malignancy is more frequently seen on the hard palate and gingiva. Oral melanomas are associated with very poor prognosis because of the tendency to metastasise or invade tissues locally more readily than other malignant tumours of the oral cavity especially in the case of a geriatric patient. The surgical approach, combined with the chemotherapy, is the first choice treatment. This report highlights a case report of 71-year-old female patient diagnosed and treated surgically for an oral malignant melanoma of the pedunculated variety affecting the hard palate and gingiva with review of literature.     

Betulinic acid induces Bax/Bak-independent cytochrome c release in human nasopharyngeal carcinoma cells

Betulinic acid (BetA) is an effective and potential anticancer chemical derived from plants. BetA can kill a broad range of tumor cell lines, but has no effect on untransformed cells. The chemical also kills melanoma, leukemia, lung, colon, breast, prostate and ovarian cancer cells via induction of apoptosis, which depends on caspase activation. However, no reports are yet available about the effects of BetA on nasopharyngeal carcinoma (NPC), a widely spread malignancy in the world, especially in East Asia. In this study, we first showed that BetA can effectively kill CNE2 cells, a cell line derived from NPC. BetA-induced CNE2 apoptosis was characterized by typical apoptosis hallmarks: caspase activation, DNA fragmentation, and cytochrome c release. Overexpression of Bcl-2 and Bcl-xL could partially prevent apoptosis caused by BetA. Moreover, Bax was not activated during the induction of apoptosis. Bax/Bak knockdown and wild-type CNE2 cells showed the same kinetics of cytochrome c release. We then showed that BetA may impair mitochondrial permeability transition pores (mPTPs), which may partially contribute to cytochrome c release. These observations suggest that BetA may serve as a potent and effective anticancer agent in NPC treatment. Further exploration of the mechanism of action of BetA could yield novel breakthroughs in anti-cancer drug discovery.     

Fed-batch mode in shake flasks by slow-release technique

Most industrial production processes are performed in fed-batch operational mode. In contrast, the screenings for microbial production strains are run in batch mode which results in completely different physiological conditions than relevant for production conditions. This may lead to wrong selections of strains. Silicone elastomer discs containing glucose crystals were developed to realize fed-batch fermentation in shake flasks. No other device for feeding was required. Glucose was fed in this way to Hansenula polymorpha cultures controlled by diffusion. Two strains of H. polymorpha were investigated in shake flasks: the wild-type strain (DSM 70277) and a recombinant strain pC10-FMD (P(FMD)-GFP). The oxygen transfer rate (OTR) and respiratory quotient (RQ) of the cultures were monitored online in shake flasks with a Respiration Activity Monitoring System (RAMOS). Formation of biomass and green fluorescent protein (GFP), pH-drift and the metabolite dynamics of glucose, ethanol and acetic acid were measured offline. With the slow-release technique overflow metabolism could be reduced leading to an increase of 85% in biomass yield. To date, 23.4 g/L cell dry weight of H. polymorpha could be achieved in shake flask. Biomass yields of 0.38-0.47 were obtained which are in the same magnitude of laboratory scale fermentors equipped with a substrate feed pump. GFP yield could be increased by a factor of 35 in Syn6-MES mineral medium. In fed-batch mode 88 mg/L GFP was synthesized with 35.9 g/L fed glucose. In contrast, only 2.5 mg/L with 40 g/L metabolized glucose was revealed in batch mode. In YNB mineral medium over 420-fold improvement in fed-batch mode was achieved with 421 mg/L GFP at 41.3 g/L fed glucose in comparison to less than 1 mg/L in batch mode with 40 g/L glucose.