The endangered Tunbridge buttercup (Ranunculus prasinus): Ecology,conservation status and introduction to the Township Lagoon Nature Reserve,Tasmania

Abstract Ranunculus prasinus is a mat-forming species of the marginal herbfields and tussock grasslands of brackish wetlands. It is only known from four wetlands, all on private land, in the driest part of Tasmania. The species has been successfully introduced from divisions from three of the populations into a secure reserve with similar vegetation to that of the natural populations. This is considered to be desirable and morally sound in that it increases the chances of survival of native biological diversity as a whole. However, ex situ measures and a gaining of security for natural populations would also be prudent.     

PhiC31 integrase mediates integration in cultured synovial cells and enhances gene expression in rabbit joints

BACKGROUND: Gene transfer to synovium in joints has been shown to be an effective approach for treating pathologies associated with rheumatoid arthritis (RA) and related joint disorders. However, the efficiency and duration of gene delivery has been limiting for successful gene therapy for arthritis. The transient gene expression that often accompanies non-viral gene delivery can be prolonged by integration of vector DNA into the host genome. We report a novel approach for non-viral gene therapy to joints that utilizes phage phiC31 integrase to bring about unidirectional genomic integration. METHODS: Rabbit and human synovial cells were co-transfected with a plasmid expressing phiC31 integrase and a plasmid containing the transgene and an attB site. Cells were cultured with or without G418 selection and the number of neo-resistant colonies or eGFP cells determined, respectively. Plasmid rescue, PCR query, and DNA sequence analysis were performed to reveal integration sites in the rabbit and human genomes. For in vivo studies, attB-reporter gene plasmids and a plasmid expressing phiC31 integrase were intra-articularly injected into rabbit knees. Joint sections were used for histological analysis of beta-gal expression, and synovial cells were isolated to measure luciferase expression. RESULTS: We demonstrated that co-transfection of a plasmid expressing phiC31 integrase with a plasmid containing the transgene and attB increased the frequency of transgene expression in rabbit synovial fibroblasts and primary human RA synoviocytes. Plasmid rescue and DNA sequence analysis of plasmid-chromosome junctions revealed integration at endogenous pseudo attP sequences in the rabbit genome, and PCR query detected integration at previously characterized integration sites in the human genome. Significantly higher levels of transgene expression were detected in vivo in rabbit knees after intra-articular injection of attB-reporter gene plasmids and a plasmid expressing phiC31 integrase. CONCLUSION: The ability of phiC31 integrase to facilitate genomic integration in synovial cells and increase transgene expression in the rabbit synovium suggests that, in combination with more efficient DNA delivery methods, this integrase system could be beneficial for treatment of rheumatoid arthritis and other joint disorders.     

Safety zones for a Sclerotinia sclerotiorum-based mycoherbicide: Accounting for regional and yearly variation in climate

Variation in the width of 'safety zones' for sheep and dairy pasture treated with a Sclerotinia sclerotiorum (Lib.) de Bary-based mycoherbicide was quantified using 10 years of climate data from each of five regions in New Zealand. Acceptable and risk-averse zones were defined as the maximum distances in any direction from a treated pasture where 'added:natural' ratios of air-borne S. sclerotiorum spores are 1:1 and 1:10, respectively. The 10-year mean 1:1 safety zone had zero width for sheep pasture at all locations, and was at most, 50 m wide for dairy pasture. The width of the 10-year mean 1:10 zone varied regionally from 314 to 443 m for sheep and from 175 to 280 m for dairy pasture, and the 90th percentile 1:10 zones were up to 41% wider. Linear relationships between safety zone width and mean wind speed were evident and these could be used to derive region-specific safety zones.     

FLUXNET and modelling the global carbon cycle

Measurements of the net CO₂ flux between terrestrial ecosystems and the atmosphere using the eddy covariance technique have the potential to underpin our interpretation of regional CO₂ source–sink patterns, CO₂ flux responses to forcings, and predictions of the future terrestrial C balance. Information contained in FLUXNET eddy covariance data has multiple uses for the development and application of global carbon models, including evaluation/validation, calibration, process parameterization, and data assimilation. This paper reviews examples of these uses, compares global estimates of the dynamics of the global carbon cycle, and suggests ways of improving the utility of such data for global carbon modelling. Net ecosystem exchange of CO₂ (NEE) predicted by different terrestrial biosphere models compares favourably with FLUXNET observations at diurnal and seasonal timescales. However, complete model validation, particularly over the full annual cycle, requires information on the balance between assimilation and decomposition processes, information not readily available for most FLUXNET sites. Site history, when known, can greatly help constrain the model‐data comparison. Flux measurements made over four vegetation types were used to calibrate the land‐surface scheme of the Goddard Institute for Space Studies global climate model, significantly improving simulated climate and demonstrating the utility of diurnal FLUXNET data for climate modelling. Land‐surface temperatures in many regions cool due to higher canopy conductances and latent heat fluxes, and the spatial distribution of CO₂ uptake provides a significant additional constraint on the realism of simulated surface fluxes. FLUXNET data are used to calibrate a global production efficiency model (PEM). This model is forced by satellite‐measured absorbed radiation and suggests that global net primary production (NPP) increased 6.2% over 1982–1999. Good agreement is found between global trends in NPP estimated by the PEM and a dynamic global vegetation model (DGVM), and between the DGVM and estimates of global NEE derived from a global inversion of atmospheric CO₂ measurements. Combining the PEM, DGVM, and inversion results suggests that CO₂ fertilization is playing a major role in current increases in NPP, with lesser impacts from increasing N deposition and growing season length. Both the PEM and the inversion identify the Amazon basin as a key region for the current net terrestrial CO₂ uptake (i.e. 33% of global NEE), as well as its interannual variability. The inversion's global NEE estimate of −1.2 Pg [C] yr⁻¹ for 1982–1995 is compatible with the PEM‐ and DGVM‐predicted trends in NPP. There is, thus, a convergence in understanding derived from process‐based models, remote‐sensing‐based observations, and inversion of atmospheric data. Future advances in field measurement techniques, including eddy covariance (particularly concerning the problem of night‐time fluxes in dense canopies and of advection or flow distortion over complex terrain), will result in improved constraints on land‐atmosphere CO₂ fluxes and the rigorous attribution of mechanisms to the current terrestrial net CO₂ uptake and its spatial and temporal heterogeneity. Global ecosystem models play a fundamental role in linking information derived from FLUXNET measurements to atmospheric CO₂ variability. A number of recommendations concerning FLUXNET data are made, including a request for more comprehensive site data (particularly historical information), more measurements in undisturbed ecosystems, and the systematic provision of error estimates. The greatest value of current FLUXNET data for global carbon cycle modelling is in evaluating process representations, rather than in providing an unbiased estimate of net CO₂ exchange.     

超高浓度培养基条件下酵母细胞生长及酒精生成的准稳态动力学研究

在1．5L搅拌式发酵罐中,使用葡萄糖质量浓度分别为120、200、280g／L的培养基进行酿酒酵母Saccharomyces cerevisiae连续发酵生成酒精的动力学研究。研究发现,当培养基中葡萄糖浓度为200和280g／L时,发酵液中残糖浓度、酒精浓度以及菌体生物量从小幅度波动的准稳态发展到大幅度波动的振荡状态。提出了伴有周期性振荡现象准稳态过程的概念,并针对该过程,建立了兼有底物和产物抑制的酵母细胞生长和产物酒精生成动力学模型。     

A neural network model of attention-modulated neurodynamics

Visual attention appears to modulate cortical neurodynamics and synchronization through various cholinergic mechanisms. In order to study these mechanisms, we have developed a neural network model of visual cortex area V4, based on psychophysical, anatomical and physiological data. With this model, we want to link selective visual information processing to neural circuits within V4, bottom-up sensory input pathways, top-down attention input pathways, and to cholinergic modulation from the prefrontal lobe. We investigate cellular and network mechanisms underlying some recent analytical results from visual attention experimental data. Our model can reproduce the experimental findings that attention to a stimulus causes increased gamma-frequency synchronization in the superficial layers. Computer simulations and STA power analysis also demonstrate different effects of the different cholinergic attention modulation action mechanisms.     

利用小鼠模型评价含有5＇-GTCGTT-3＇特征序列的人CpG寡脱氧核苷酸的免疫刺激活性

为了寻找合适的动物模型来评价人CpG寡脱氧核苷酸（CpG-ODN）的活性,研究了CpG2006等含有5＇-GTCGTT-3＇特征序列的人CpG-ODN对小鼠的免疫刺激活性。在体外它们能够促进小鼠脾淋巴细胞转化,促进B细胞分泌IgM,但不能诱生高水平的IFN-γ。研究了CpG2006等序列在体内作为疫苗佐剂对HBsAg免疫效果的影响,发现（1）人CpG-ODN能够明显提高抗-HBs抗体水平,并逆转Al（OH）     

流域尺度水土保持生物措施减沙效益研究

1　引　　言黄土高原位于黄河中游 ,流经黄土高原的 9大支流进入河口镇至花园口的中游河段 ,总径流量为 187× 10 8ｍ3 ,输沙量占黄河流域总沙量的 90 % .建国以来以修建梯田坝地、造林种草、建谷坊、调整种植结构为主的水土保持工程、生物治理长年不懈 ,其目的在于减水减沙 ,改善流域生态环境 .但是 ,除部分中小尺度流域进入生态、经济效益良性循环的轨道外 ,大部分地区生态环境仍然十分脆弱 ,部分地区有恶化之势 .因此 ,定量评价水土保持工程、生物措施的治理效益是广为关注的研究课题 ,虽相关的研究成果不少 ,但是绝大部分工作是评价水土…     

Phylogenetic scale in ecology and evolution

Aim

Many important patterns and processes vary across the phylogeny and depend on phylogenetic scale. Nonetheless, phylogenetic scale has never been formally conceptualized, and its potential remains largely unexplored. Here, we formalize the concept of phylogenetic scale, review how phylogenetic scale has been considered across multiple fields and provide practical guidelines for the use of phylogenetic scale to address a range of biological questions.

Innovation

We summarize how phylogenetic scale has been treated in macroevolution, community ecology, biogeography and macroecology, illustrating how it can inform, and possibly resolve, some of the longstanding controversies in these fields. To promote the concept empirically, we define phylogenetic grain and extent, scale dependence, scaling and the domains of phylogenetic scale. We illustrate how existing phylogenetic data and statistical tools can be used to investigate the effects of scale on a variety of well‐known patterns and processes, including diversification rates, community structure, niche conservatism or species‐abundance distributions.

Main conclusions

Explicit consideration of phylogenetic scale can provide new and more complete insight into many longstanding questions across multiple fields (macroevolution, community ecology, biogeography and macroecology). Building on the existing resources and isolated efforts across fields, future research centred on phylogenetic scale might enrich our understanding of the processes that together, but over different scales, shape the diversity of life.