Unlocking the potential of Google Earth as a tool in invasion science

Distribution data are central to many invasion science applications. The shortage of good information on the distribution of alien species and their spatial dynamics is largely attributable to the cost, effort and expertise required to monitor these species over large areas. Virtual globes, particularly Google Earth, are free and user-friendly software which provide high-resolution aerial imagery for the entire globe. We suggest this has enormous potential for invasion science. We provide suggestions and tools for gathering data on the distribution and abundance of invasive alien trees using visual interpretation of Google Earth imagery, and propose how these data may be used for a number of purposes, including calculating useful metrics of invasions, prioritising species or areas for management and predicting potential distributions of species. We also suggest various practical uses of Google Earth, such as providing a tool for early detection of emerging invasions, monitoring invasions over time, and to help researchers and managers identify suitable field study sites. Virtual globes such as Google Earth are not without limitations and we provide guidance on how some of these can be overcome, or when imagery from Google Earth may not be fit for invasion science purposes. Because of Google Earth’s huge popularity and ease of use, we also highlight possibilities for awareness-raising and information sharing that it provides. Finally, we provide the foundations and guidelines for a virtual global network of sentinel sites for early detection, monitoring and data gathering of invasive alien trees, which we propose should be developed as part of a “citizen science” effort. There has been limited use of virtual globes by invasion scientists and managers; it is our hope that this paper will stimulate their greater use, both within the field of invasion science and within ecology generally.     

Cosmogenic 10Be as a potential dating tool in peat

Because ombrotrophic peat bogs receive inputs of water, nutrients, pollutants, and xerobiotic materials solely from the atmosphere, and accumulate organic matter vertically, dated peat cores can provide a historical record of deposition. We propose a novel method for accurately determining dates of peat, based on cosmogenic ¹⁰Be. In a laboratory study, we document limited post-depositional mobility of atmospherically-deposited Be, a requisite for ¹⁰Be dating. We provide an example of how the ²¹⁰Pb-dated upper portion of a peat core can be used to back-calculate a site-specific ¹⁰Be deposition rate, which can then be used to estimate dates for peat throughout a core, and also discuss limitations to the application of cosmogenic ¹⁰Be to the dating of peat deposits.     

Modified atmosphere treatments as a potential disinfestation technique for arthropod pests in greenhouses

Incidental transport of arthropods on plant material can be a significant mode of pest entry into greenhouses. We evaluated the use of controlled atmosphere treatments as a potential way to eliminate arthropod pests on plant propagules (i.e., cuttings or small rooted plants). Lethal exposures to CO2 or N2 were determined for common greenhouse pests including fungus gnat larvae, Bradysia sp.; green peach aphid, Myzus persicae (Sulzer); sweetpotato whitefly, Bemisia sp.; twospotted spider mite, Tetranychus urticae Koch; and western flower thrips, Frankliniella occidentalis (Pergande). We also studied the effect of pest species, life stage, and presence or absence of plants on efficacy of modified atmosphere treatments. Finally, effects of modified atmospheres on plant quality were evaluated for several bedding plant species including begonia, Begonia semperflorens-cultorum Hort. 'Cocktail Series', chrysanthemum, Dendranthema grandiflora Tzvelev., geranium, Pelargonium X hortorum L.H. Bailey, and impatiens, Impatiens wallerana Hook f., and among cultivars of geranium and chrysanthemum. Exposure for 12-18 h to >99% N2 or CO2 caused complete mortality of aphids, mites, thrips, and whiteflies. Fungus gnat larvae were more tolerant of hypoxic conditions. Adult mites and eggs were equally susceptible. For most pests, there was no difference in response to atmospheres modified by CO2 or N2. However, there was variation in response among plant species and cultivars, with effects ranging from delayed flowering to mortality. Despite the possibility of adverse effects on some plants, this work indicates that use of modified atmospheres has potential to eliminate arthropod pests on plant propagules before they are introduced into greenhouses.     

Exotic shrub invasion in a montane grassland: the role of fire as a potential restoration tool

In recent years, invasion of native grasslands by exotic woody plants has been recognized as a global problem with multiple adverse ecological and socio-economic consequences. Reasons for such expansions are numerous, including fire suppression. An important example of this problem is the native montane grassland in the Nilgiris of the Western Ghats in India, a biodiversity hotspot threatened by invasion of multiple woody species. In this study, the impacts of the highly invasive, nitrogen fixing exotic shrub Cytisus scoparius (Scotch broom) on the grassland community and ecosystem function have been quantified and the role of fire as a potential management tool evaluated. I established paired plots in uninvaded and broom-invaded grasslands that were either unburned or burned by an unplanned wildfire event. Invasion negatively impacted the grassland community structure and composition, favoring shade tolerant and weedy native plants, but did not greatly alter ecosystem function. Burning broom patches to eliminate the stands resulted in lower soil moisture and nitrogen levels 18 months after the fire. Yet, there were no notable fire effects on the grassland communities or ecosystem properties. Taken together, the results suggest that fire might be an effective tool for broom control. At the end of the study period burned-broom communities did not become more similar to uninvaded-grasslands; presumably the recovery process may be slow without additional management intervention.     

Mass spectrometry as a diagnostic and a cancer biomarker discovery tool: opportunities and potential limitations

Serum proteomic profiling, by using surfaced-enhanced laser desorption/ionization-time-of-flight mass spectrometry, is one of the most promising new approaches for cancer diagnostics. Exceptional sensitivities and specificities have been reported for some cancer types such as prostate, ovarian, breast, and bladder cancers. These sensitivities/specificities are far superior to those obtained by using classical cancer biomarkers. In this review, I concentrate more on questions that cast doubt on the results reported and propose experiments to investigate these questions in detail, before the technique is used at the clinic. It is clear that the method needs to be externally and thoroughly validated before clinical implementation is warranted.     

Ixodes ricinus: the potential of two-dimensional gel electrophoresis as a tool for studying host-vector-pathogen interactions

Ixodes ricinus is a three-host tick, with three active instars. For moulting to occur the tick has to find a host where it can take a blood meal. Throughout feeding I. ricinus can be infected or infect the host with different pathogens, e.g., Tick-Borne Encephalitis virus or Borrelia burgdorferi. The host-vector-pathogen interaction is very complex, making a detailed study difficult. Here we analyse the potential of two-dimensional gel electrophoresis (2DE) to study the host-vector-pathogen interaction. We examined 20 nymphs, which as larvae parasitised either mouse or hen. After moulting, they were kept alive for up to 30 weeks, to analyse whether tick ageing influenced host determination, and for comparison of the 2D-gels. Even though the number of proteins in the gel decreased during ageing, some proteins of the host determination persisted for all 30 weeks. We also discovered persisting proteins in relation to nymphs. These findings showed that 2DE is suitable as a tool for studying host-vector-pathogen interactions.     

Selective felling as a potential tool for maintaining biodiversity in managed forests

In Sweden one forestry method, the clear-cutting method, has been used all over the country despite differences in climate, topography etc. At present there is a growing interest in using alternative methods such as selective felling, which to a larger extent mimic natural disturbances. In this study we compare virgin forests with stands which have been cut with old selective felling (dimension felling), new selective felling (single tree selection felling), and clear-cutting with respect to frequency of characters important to biodiversity (mainly dead wood). The frequency of different types of dead wood decreases with increasing intensity of the cutting method in the following order: old selective felling, new selective felling, and clear-cutting. New selective felling had higher amounts and quality of dead wood compared to clear-cutting. New selective felling also showed less differences compared to virgin forests than clear-cutting. Dead wood in new selective felling compared to clear-cutting may offer substrate for different types of faunas because of the environment surrounding the dead wood. Even if the new selective felling method seems to provide higher amounts of dead wood compared to the clear-cutting method, further studies of organisms utilising the dead wood are needed. New selective felling does not seem to solve the problem of decreasing availability of dead wood in managed forests and there is still a need to preserve unmanaged forest patches in a landscape perspective in order to offer habitats with a high amount of dead wood.     

Dimethylsulfoxide as a potential tool for analysis of compartmentation in living plant cells

Data are presented which indicate that dimethylsulfoxide (DMSO) acts selectively on the plasma membrane of cultured tobacco cells, rendering it more permeable to small molecules, while having a far smaller effect on the permeability of the vacuolar membrane. The results which support this conclusion are: (a) DMSO (5 to 10%, by volume) causes complete release of [¹⁴C]tryptophan newly synthesized from [¹⁴C]indole while causing efflux of only about 20% of the total intracellular tryptophan pool; (b) similar concentrations of DMSO do not cause substantial release from these cells of phenolic compounds or preloaded neutral red, nor of β-cyanin from fresh beet discs; (c) kinetic studies of release of tryptophan and neutral sugars and of efflux of ⁸⁶Rb⁺ show that DMSO selectively promotes rapid release of a portion of the total pool, followed by a substantially slower release of the remaining pool; (d) when tobacco cell protoplasts are incubated in the presence of 7.5% (by volume) DMSO, rapid lysis is observed concomitant with the release of intact vacuoles. These data indicate that a procedure involving a brief treatment of intact plant cells or tissues with DMSO may be used to assess the distribution of metabolites between cytoplasmic and vacuolar compartments.     

Quantity of AgNORs in gastric endocrine carcinoid tumours as a potential prognostic tool

In order to assess if the quantity of silver-stained nucleolar organizer region (AgNOR) proteins represents a prognostic tool in gastric carcinoids, a standardised AgNOR analysis was performed on 24 samples collected from the pathology archives of the Universities of Messina and Parma; the samples were taken at surgery from 11 males and 13 females (mean age 55 yrs, age range 28-77 yrs); 13 cases were defined as Type I, 1 case as Type II and 10 cases as Type III; 16 cases showed a diameter <1 cm, 8 >1 cm. Only 6 tumours were deeply invasive, breaking through the muscularis propria or the subserosa. The proliferative status of carcinoids performed by Ki67 protein antibodies was available in 20/24 cases. The quantification of AgNORs was performed according to the guidelines of the Committee on AgNOR Quantification and the mean area (microm2) of AgNORs per nucleus (NORA) was determined by means of image analyser and specific software programs. The relationship between NORA values and Ki67 data was investigated by Spearman correlation test. The mean NORA value of all 24 gastric carcinoids was 1.279 microm2 (SD 0.404); values ranged from 0.734 to 2.142 microm2. A significantly higher (p < 0.001) mean NORA value (1.736 microm2; SD 0.283) was found in tumours larger than 1 cm, in comparison to the smaller neoplasms (1.051 microm2; SD 0.214); moreover, cases showing deep wall invasion exhibited a mean NORA value of 1.765 microm2 (SD 0.276), significantly higher (p < 0.001) than those with superficial growth (1.118 microm2; SD 0.296). Finally, a similar highly significant difference was seen between type III carcinoids (1.615 microm2; SD 0.375) and type I-II (1.040 microm2; SD 0.208). A linear relationship between Ki67 and corresponding NORA values was obtained by the Spearman correlation test (p = 0.001). No other significant correlations were found between mean NORA values and other clinico-pathological parameters. The AgNOR method seems to be an additional tool potentially able to predict the prognosis of this kind of endocrine tumour, facilitating the identification of fast-growing tumours and being able to directly correlate with the size, deep invasion of gastric wall and tumour type, generally considered as the best prognostic indicators.     

Piscivory by large eels on young-of-the-year fishes: its potential as a biomanipulation tool

Strong piscivory by eels Anguilla anguilla , which were regularly stocked in the Bautzen Reservoir, Germany, as a biomanipulation tool, was observed, with the number of fishes per stomach containing fish being 2· 2 ± 1·3 (mean ±  s . d .). The 0+ year perch Perca fluviatilis was the most frequent prey item (54%), and 0+ year pikeperch Sander lucioperca was the most important prey in terms of biomass (45%).     

Multiple co-inertia analysis: a tool for assessing synchrony in the temporal variability of aquatic communities

Multitable techniques are rarely used for investigating patterns in ecological data surveys despite their ability to deal with the spatial and/or temporal stability of assemblages. Based on a covariance optimisation criterion, Multiple Co-inertia analysis (MCOA) enables the simultaneous ordination of several tables. Such analysis allows the representation of the stable vs. unstable part of the assemblage structure in comparison to a reference derived from each table. We used MCOA on multiple time series of invertebrate sampling to show that synchrony in the temporal variability of communities can establish between geographically distant locations despite the spatial and temporal plasticity of the faunistic responses to long-term changes in environmental conditions.     

Leucine incorporation and its potential as a measure of protein synthesis by bacteria in natural aquatic systems

Leucine incorporation was examined as a method for estimating rates of protein synthesis by bacterial assemblages in natural aquatic systems. The proportion of the total bacterial population that took up leucine in three marine environments was high (greater than 50%). Most of the leucine (greater than 90%) taken up was incorporated into protein, and little (less than 20%) was degraded to other amino acids, except in two oligotrophic marine environments. In samples from these two environments, ca. 50% of the leucine incorporated had been degraded to other amino acids, which were subsequently incorporated into protein. The degree of leucine degradation appears to depend on the organic carbon supply, as the proportion of 3H-radioactivity incorporated into protein that was recovered as [3H]leucine after acid hydrolysis increased with the addition of pyruvate to oligotrophic water samples. The addition of extracellular leucine inhibited total incorporation of [14C]pyruvate (a precursor for leucine biosynthesis) into protein. Furthermore, the proportion of [14C]pyruvate incorporation into protein that was recovered as [14C]leucine decreased with the addition of extracellular leucine. These results show that the addition of extracellular leucine inhibits leucine biosynthesis by marine bacterial assemblages. The molar fraction of leucine in a wide variety of proteins is constant, indicating that changes in leucine incorporation rates reflect changes in rates of protein synthesis rather than changes in the leucine content of proteins. The results demonstrate that the incorporation rate of [3H]leucine into a hot trichloroacetic acid-insoluble cell fraction can serve as an index of protein synthesis by bacterial assemblages in aquatic systems.     

Raman spectroscopy as a potential tool for detection of Brucella spp. in milk

Detection of Brucella, causing brucellosis, is very challenging, since the applied techniques are mostly time-demanding and not standardized. While the common detection system relies on the cultivation of the bacteria, further classical typing up to the biotype level is mostly based on phenotypic or genotypic characteristics. The results of genotyping do not always fit the existing taxonomy, and misidentifications between genetically closely related genera cannot be avoided. This situation gets even worse, when detection from complex matrices, such as milk, is necessary. For these reasons, the availability of a method that allows early and reliable identification of possible Brucella isolates for both clinical and epidemiological reasons would be extremely useful. We evaluated micro-Raman spectroscopy in combination with chemometric analysis to identify Brucella from agar plates and directly from milk: prior to these studies, the samples were inactivated via formaldehyde treatment to ensure a higher working safety. The single-cell Raman spectra of different Brucella, Escherichia, Ochrobactrum, Pseudomonas, and Yersinia spp. were measured to create two independent databases for detection in media and milk. Identification accuracies of 92% for Brucella from medium and 94% for Brucella from milk were obtained while analyzing the single-cell Raman spectra via support vector machine. Even the identification of the other genera yielded sufficient results, with accuracies of >90%. In summary, micro-Raman spectroscopy is a promising alternative for detecting Brucella. The measurements we performed at the single-cell level thus allow fast identification within a few hours without a demanding process for sample preparation.     

The potential of metabolite profiling as a selection tool for genotype discrimination in Populus

Differences between wild-type Populus tremulaxalba and two transgenic lines with modified lignin monomer composition, were interrogated using metabolic profiling. Analysis of metabolite abundance data by GC-MS, coupled with principal components analysis (PCA), successfully differentiated between lines that had distinct phenotypes, whether samples were taken from the cambial zone or non-lignifying suspension tissue cultures. Interestingly, the GC-MS analysis detected relatively few phenolic metabolites in cambial extracts, although a single metabolite associated with the differentiation between lines was directly related to the phenylpropanoid pathway or other down-stream aspects of lignin biosynthesis. In fact, carbohydrates, which have only an indirect relationship with the modified lignin monomer composition, featured strongly in the line-differentiating aspects of the statistical analysis. Traditional HPLC analysis was employed to verify the GC-MS data. These findings demonstrate that metabolic traits can be dissected reliably and accurately by metabolomic analyses, enabling the discrimination of individual genotypes of the same tree species that exhibit marked differences in industrially relevant wood traits. Furthermore, this validates the potential of using metabolite profiling techniques for marker generation in the context of plant/tree breeding for industrial applications.     

Hypometabolic induced state: a potential tool in biomedicine and space exploration

This paper will first review the issue of hypometabolism in mammals with a focus on the strategies these animals evolved to cope with life challenge in hostile environments (e.g., cold weather and/or shortage of food). The different types of natural hypometabolism (hibernation, torpor, winter sleep) will be briefly described as well as major adaptations in body temperature, and energy and cell metabolism. In the second part of this review the issue of inducing a hypometabolic state in mammals will be afforded with special attention paid to changes in body temperature and metabolism, regulation of gene expression and the possible role of hibernation inducing factors. Finally, an overview of the potential of inducing a hypometabolic state in the human as related to the broad field of biomedicine will be given.