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21.
J. W. Dover A. Rescia S. Fungariño J. Fairburn P. Carey P. Lunt C. Arnot R. L. H. Dennis C. J. Dover 《Journal of Insect Conservation》2011,15(4):523-538
Extensive grasslands are considered to be of high biodiversity value, but are under threat from intensification and abandonment.
We studied butterfly species richness and abundance in 47 hay and grazing meadows in the Picos de Europa, northern Spain in
2004. Nine transects were walked around the perimeter of the meadows from the 1 June to 28 July with butterflies recorded
to species or species-group. Land-use, abiotic, and sward variables were also recorded. Change in meadow extent was estimated
by comparing a digital map of open meadows with a cadastral map with 1950s provenance. We found: A decrease in open area,
mostly attributable to reduction in grazing meadows. 75 or more butterfly species with species richness principally, and positively,
influenced by altitude and presence of scrub in the body of the meadow. Hay meadow management was a positive influence on
richness of satyrids. When all butterflies were considered together, the only significant factor influencing abundance was
Plantago lanceolata (−ve). For sub-groups of the butterfly community there was no consistent pattern, although P. lanceolata was identified as a (−ve) factor in relation to hesperiid, nymphalid, satyrid, and Viola-feeding fritillary groups. Several regression models included components that could be linked to abiotic influences (water,
aspect, altitude) but many were indicative of abandonment or relaxation of management intensity (scrub, Pteridium aquilinum, Asphodelus albus), sward components, fragmentation (distance to nearest meadow, number of meadows within 100 m), and land use (hay management,
summer grazing). The results are discussed in relation to changing socio-economics, including the potential impact of tourism,
and the need for financial instruments to support extensive farming. 相似文献
22.
Ramirez-Llodra E Tyler PA Baker MC Bergstad OA Clark MR Escobar E Levin LA Menot L Rowden AA Smith CR Van Dover CL 《PloS one》2011,6(8):e22588
The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life--SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO(2) and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO(2) and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short discussion on protection and management methods. 相似文献
23.
Novel Forms of Structural Integration between Microbes and a Hydrothermal Vent Gastropod from the Indian Ocean 总被引:2,自引:0,他引:2
Shana K. Goffredi Anders Warén Victoria J. Orphan Cindy L. Van Dover Robert C. Vrijenhoek 《Applied microbiology》2004,70(5):3082-3090
Here we describe novel forms of structural integration between endo- and episymbiotic microbes and an unusual new species of snail from hydrothermal vents in the Indian Ocean. The snail houses a dense population of γ-proteobacteria within the cells of its greatly enlarged esophageal gland. This tissue setting differs from that of all other vent mollusks, which harbor sulfur-oxidizing endosymbionts in their gills. The significantly reduced digestive tract, the isotopic signatures of the snail tissues, and the presence of internal bacteria suggest a dependence on chemoautotrophy for nutrition. Most notably, this snail is unique in having a dense coat of mineralized scales covering the sides of its foot, a feature seen in no other living metazoan. The scales are coated with iron sulfides (pyrite and greigite) and heavily colonized by - and δ-proteobacteria, likely participating in mineralization of the sclerites. This novel metazoan-microbial collaboration illustrates the great potential of organismal adaptation in chemically and physically challenging deep-sea environments. 相似文献
24.
van Gool CJ van Houwelingen AC Hornstra G 《The Journal of nutritional biochemistry》2000,11(11-12):543-547
Phenylketonuric patients are on a special diet that lacks certain essential fatty acids. This study evaluates the essential fatty acid status of a group of phenylketonuric patients in the Netherlands undergoing dietary treatment. To this end, the essential fatty acid status of nine phenylketonuria patients was studied. On the basis of age and gender, two control subjects were selected for each patient. The essential fatty acid composition of duplicate food portions and the essential fatty acid status of plasma and erythrocytes were analyzed. Phenylketonuria subjects had a different essential fatty acid profile from their peers, especially concerning the n-3 fatty acids. N-6 and n-3 fatty long-chain polyenes were hardly consumed by phenylketonuria subjects, in contrast to the control subjects. Linoleic acid, on the other hand, was consumed in significantly higher amounts by phenylketonuria subjects and made up about 40% of their daily fat consumption. The essential fatty acid consumption pattern of the phenylketonuria subjects is mirrored by the essential fatty acid concentrations in blood. The essential fatty acid status of the phenylketonuric diet should be improved in order to prevent deficiency in n-3 fatty acids. 相似文献
25.
Lipoteichoic acid is an important microbe-associated molecular pattern of Lactobacillus rhamnosus GG
Claes Ingmar JJ Segers Marijke E Verhoeven Tine LA Dusselier Michiel Sels Bert F De Keersmaecker Sigrid CJ Vanderleyden Jos Lebeer Sarah 《Microbial cell factories》2012,11(1):1-8
Background
Receptors with a single transmembrane (TM) domain are essential for the signal transduction across the cell membrane. NMR spectroscopy is a powerful tool to study structure of the single TM domain. The expression and purification of a TM domain in Escherichia coli (E.coli) is challenging due to its small molecular weight. Although ketosteroid isomerase (KSI) is a commonly used affinity tag for expression and purification of short peptides, KSI tag needs to be removed with the toxic reagent cyanogen bromide (CNBr).Result
The purification of the TM domain of p75 neurotrophin receptor using a KSI tag with the introduction of a thrombin cleavage site is described herein. The recombinant fusion protein was refolded into micelles and was cleaved with thrombin. Studies showed that purified protein could be used for structural study using NMR spectroscopy.Conclusions
These results provide another strategy for obtaining a single TM domain for structural studies without using toxic chemical digestion or acid to remove the fusion tag. The purified TM domain of p75 neurotrophin receptor will be useful for structural studies. 相似文献26.
Nadine?AME?van der BeekEmail author Juna?M?de Vries Marloes?LC?Hagemans Wim?CJ?Hop Marian?A?Kroos John?HJ?Wokke Marianne?de Visser Baziel?GM?van Engelen Jan?BM?Kuks Anneke?J?van der Kooi Nicolette?C?Notermans Karin?G?Faber Jan?JGM?Verschuuren Arnold?JJ?Reuser Ans?T?van der Ploeg Pieter?A?van Doorn 《Orphanet journal of rare diseases》2012,7(1):88
Background
Due partly to physicians’ unawareness, many adults with Pompe disease are diagnosed with great delay. Besides, it is not well known which factors influence the rate of disease progression, and thus disease outcome. We delineated the specific clinical features of Pompe disease in adults, and mapped out the distribution and severity of muscle weakness, and the sequence of involvement of the individual muscle groups. Furthermore, we defined the natural disease course and identified prognostic factors for disease progression.Methods
We conducted a single-center, prospective, observational study. Muscle strength (manual muscle testing, and hand-held dynamometry), muscle function (quick motor function test), and pulmonary function (forced vital capacity in sitting and supine positions) were assessed every 3–6 months and analyzed using repeated-measures ANOVA.Results
Between October 2004 and August 2009, 94 patients aged between 25 and 75 years were included in the study. Although skeletal muscle weakness was typically distributed in a limb-girdle pattern, many patients had unfamiliar features such as ptosis (23%), bulbar weakness (28%), and scapular winging (33%). During follow-up (average 1.6 years, range 0.5-4.2 years), skeletal muscle strength deteriorated significantly (mean declines of ?1.3% point/year for manual muscle testing and of ?2.6% points/year for hand-held dynamometry; both p<0.001). Longer disease duration (>15 years) and pulmonary involvement (forced vital capacity in sitting position <80%) at study entry predicted faster decline. On average, forced vital capacity in supine position deteriorated by 1.3% points per year (p=0.02). Decline in pulmonary function was consistent across subgroups. Ten percent of patients declined unexpectedly fast.Conclusions
Recognizing patterns of common and less familiar characteristics in adults with Pompe disease facilitates timely diagnosis. Longer disease duration and reduced pulmonary function stand out as predictors of rapid disease progression, and aid in deciding whether to initiate enzyme replacement therapy, or when.27.
Cindy Lee Van Dover Richard A. Lutz 《Journal of experimental marine biology and ecology》2004,300(1-2):273-307
In situ and laboratory experiments conducted over the past quarter of a century have greatly increased our understanding of the ecology of deep-sea hydrothermal systems. Early experiments suggested that chemosynthetic primary production constituted the principal source of organic matter for biological communities associated with vents, although subsequent studies have revealed many complexities associated with interactions between microbes and higher organisms inhabiting these ecosystems. A diversity of host-microbial symbiont relationships has been identified and experimental studies have revealed the exquisite physiological adaptations within the giant tubeworm, Riftia pachyptila, for the uptake, fixation, and assimilation of carbon. In vitro experiments demonstrated the unusual sulfide binding properties of tubeworm hemoglobin that prevent inhibition of the cytochrome-c oxidase enzyme system during transport of sulfide to symbiont-bearing tissues. Studies of respiration and growth of several species of vent organisms conducted over the past two decades transformed earlier views that low metabolism and slow growth are characteristics of all organisms inhabiting all deep-sea environments. Results of recent experiments suggest that metabolic rates correlate with the degree of mobility of the organisms rather than with any specific attribute of the deep-sea environment itself, and growth rates of certain vent organisms (e.g., R. pachyptila) were found to be among the highest in any marine environments. While extreme thermal tolerance has been suggested as characteristic of certain vent fauna (e.g., alvinellid polychaetes and alvinocarid shrimp), the majority of vent metazoans live at temperatures below 20 °C and additional experiments are necessary to reconcile field experiments documenting thermal tolerance in situ, thermal tolerance in vivo, and thermal sensitivity of biochemical constituents of vent organisms. Transplantation and clearance experiments, as well as in situ characterization of vent fluid chemistry, have greatly increased our understanding of organism–environment interactions. Early analyses of metazoan egg size and larval morphology, coupled with in vivo larval culture experiments, available physical oceanographic data, and genetic studies of gene flow, have contributed greatly to our understanding of mechanisms of dispersal between widely separated vent sites. The documentation of invertebrate colonization and succession of new vents following a volcanic eruption, and a series of manipulative field experiments, provide considerable insights into the relative roles of abiotic conditions and biotic interactions in structuring vent communities. Recent and emerging technological developments, such as in situ chemical analyzers, observatory approaches, and laboratory-based pressure culture systems, should provide invaluable new experimental tools for tackling many remaining questions concerning the ecology of deep-sea hydrothermal systems. 相似文献
28.
Nir Dover Jason R. Barash Karen K. Hill Karen W. Davenport Hazuki Teshima Gary Xie Stephen S. Arnon 《PloS one》2013,8(4)
Sanger and shotgun sequencing of Clostridium botulinum strain Af84 type Af and its botulinum neurotoxin gene (bont) clusters identified the presence of three bont gene clusters rather than the expected two. The three toxin gene clusters consisted of bont subtypes A2, F4 and F5. The bont/A2 and bont/F4 gene clusters were located within the chromosome (the latter in a novel location), while the bont/F5 toxin gene cluster was located within a large 246 kb plasmid. These findings are the first identification of a C. botulinum strain that contains three botulinum neurotoxin gene clusters. 相似文献
29.
Slips, strings and species 总被引:3,自引:0,他引:3
G A Dover 《Trends in genetics : TIG》1989,5(4):100-102
30.