Water stress tolerance of shrubs in Mediterranean-type climate regions: Convergence of fynbos and succulent karoo communities with California shrub communities

Mediterranean-type climate regions are highly biodiverse and predicted to be particularly sensitive to climate change. Shrubs of the mediterranean-type climate region of South Africa are highly threatened, and their response to water stress has been comparatively little studied. Resistance to water stress induced xylem cavitation (P(50)) and xylem specific hydraulic conductivity (K(s)) were measured in 15 shrub species from fynbos and succulent karoo communities of South Africa. Species displayed a fivefold variation in cavitation resistance (P(50) of -1.9 to -10.3 MPa) with succulent karoo species displaying greater interspecific variability in P(50) than fynbos species. Principal components analysis (including P(50), minimum seasonal water potential, K(s), and xylem density) showed the response to water stress in fynbos species to be similar to chaparral species from the mediterranean-type climate region of California. The data suggest convergence of community and species-specific water stress "strategies" between these mediterranean-type climate regions with respect to their xylem traits. On the basis of the current study and reported plant death and dieback in these regions, woody species within the fynbos may be more susceptible to climate warming and drying than those within the succulent karoo that appear to be utilizing more diverse xylem strategies in response to water stress.     

Kinetic and Thermodynamic Solubility Values of Some Bioactive Compounds

Thermodynamic solubility is a decisive physicochemical property in drug development. The Chasing Equilibrium method offers an alternative to the classical procedures to measure the solubility of compounds with acid–base properties. The method is fast and yields accurate results. In this work, the solubility of several compounds including acids and bases was determined through the Chasing Equilibrium approach. A study of experimental conditions in terms of sample weight was performed to measure solubilities. The study shows that only a limited range of weights, depending on the nature and solubility of the compounds, is adequate to obtain reliable results.     

Prospects for tropical forest biodiversity in a human-modified world

The future of tropical forest biodiversity depends more than ever on the effective management of human-modified landscapes, presenting a daunting challenge to conservation practitioners and land use managers. We provide a critical synthesis of the scientific insights that guide our understanding of patterns and processes underpinning forest biodiversity in the human-modified tropics, and present a conceptual framework that integrates a broad range of social and ecological factors that define and contextualize the possible future of tropical forest species. A growing body of research demonstrates that spatial and temporal patterns of biodiversity are the dynamic product of interacting historical and contemporary human and ecological processes. These processes vary radically in their relative importance within and among regions, and have effects that may take years to become fully manifest. Interpreting biodiversity research findings is frequently made difficult by constrained study designs, low congruence in species responses to disturbance, shifting baselines and an over-dependence on comparative inferences from a small number of well studied localities. Spatial and temporal heterogeneity in the potential prospects for biodiversity conservation can be explained by regional differences in biotic vulnerability and anthropogenic legacies, an ever-tighter coupling of human-ecological systems and the influence of global environmental change. These differences provide both challenges and opportunities for biodiversity conservation. Building upon our synthesis we outline a simple adaptive-landscape planning framework that can help guide a new research agenda to enhance biodiversity conservation prospects in the human-modified tropics.     

Characterization and evolution of two bacteriome‐inhabiting symbionts in cixiid planthoppers (Hemiptera: Fulgoromorpha: Pentastirini)

Like other plant sap‐sucking insects, planthoppers within the family Cixiidae (Insecta: Hemiptera: Fulgoromorpha) host a diversified microbiota. We report the identification and first molecular characterization of symbiotic bacteria in cixiid planthoppers (tribe: Pentastirini). Using universal eubacterial primers we first screened the eubacterial 16S rRNA sequences in Pentastiridius leporinus (Linnaeus) with PCR amplification, cloning, and restriction fragment analysis. We identified three main 16S rRNA sequences that corresponded to a Wolbachia bacterium, a plant pathogenic bacterium, and a novel gammaproteobacterial symbiont. A fourth bacterial species affiliated with ‘Candidatus Sulcia muelleri’ was detected in PCR assays using primers specific for the Bacteroidetes. Within females of two selected cixiid planthoppers, P. leporinus and Oliarus filicicola, fluorescence In situ hybridization analysis and transmission electron microscopy observations showed that ‘Ca. Sulcia muelleri’ and the novel gammaproteobacterial symbiont were housed in separate bacteriomes. Phylogenetic analysis revealed that both of these symbionts occurred in at least four insect genera within the tribe Pentastirini. ‘Candidatus Purcelliella pentastirinorum’ was proposed as the novel gammaproteobacterial symbiont.     

Infrastructure for the life sciences: design and implementation of the UniProt website

Background  

The UniProt consortium was formed in 2002 by groups from the Swiss Institute of Bioinformatics (SIB), the European Bioinformatics Institute (EBI) and the Protein Information Resource (PIR) at Georgetown University, and soon afterwards the website was set up as a central entry point to UniProt resources. Requests to this address were redirected to one of the three organisations' websites. While these sites shared a set of static pages with general information about UniProt, their pages for searching and viewing data were different. To provide users with a consistent view and to cut the cost of maintaining three separate sites, the consortium decided to develop a common website for UniProt. Following several years of intense development and a year of public beta testing, the domain was switched to the newly developed site described in this paper in July 2008.     

Identification of two GH18 chitinase family genes and their use as targets for detection of the crayfish-plague oomycete Aphanomyces astaci

Background  

The oomycete Aphanomyces astaci is regarded as the causative agent of crayfish plague and represents an evident hazard for European crayfish species. Native crayfish populations infected with this pathogen suffer up to 100% mortality. The existence of multiple transmission paths necessitates the development of a reliable, robust and efficient test to detect the pathogen. Currently, A. astaci is diagnosed by a PCR-based assay that suffers from cross-reactivity to other species. We developed an alternative closed-tube assay for A. astaci, which achieves robustness through simultaneous amplification of multiple functionally constrained genes.     

Prevalence Study of Yaws in the Democratic Republic of Congo Using the Lot Quality Assurance Sampling Method

Background

Until the 1970s the prevalence of non-venereal trepanomatosis, including yaws, was greatly reduced after worldwide mass treatment. In 2005, cases were again reported in the Democratic Republic of the Congo. We carried out a survey to estimate the village-level prevalence of yaws in the region of Equator in the north of the country in order to define appropriate strategies to effectively treat the affected population.

Methodology/Principal Findings

We designed a community-based survey using the Lot Quality Assurance Sampling method to classify the prevalence of active yaws in 14 groups of villages (lots). The classification into high, moderate, or low yaws prevalence corresponded to World Health Organization prevalence thresholds for identifying appropriate operational treatment strategies. Active yaws cases were defined by suggestive clinical signs and positive rapid plasma reagin and Treponema pallidum hemagglutination serological tests. The overall prevalence in the study area was 4.7% (95% confidence interval: 3.4–6.0). Two of 14 lots had high prevalence (>10%), three moderate prevalence (5–10%) and nine low prevalence (<5%.).

Conclusions/Significance

Although yaws is no longer a World Health Organization priority disease, the presence of yaws in a region where it was supposed to be eradicated demonstrates the importance of continued surveillance and control efforts. Yaws should remain a public health priority in countries where previously it was known to be endemic. The integration of sensitive surveillance systems together with free access to effective treatment is recommended. As a consequence of our study results, more than 16,000 people received free treatment against yaws.