bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling local and long‐distance dispersal of invasive emerald ash borer Agrilus planipennis (Coleoptera) in North America
Authors: Muirhead Jim R. , Leung Brian , van Overdijk Colin , Kelly David W. , Nandakumar Kanavillil , Marchant Kenneth R. , MacIsaac Hugh J. 
Published: December 2005

ABSTRACTLimiting the damage by non‐indigenous species requires rapid determination of current and potential distributions and vectors of dispersal, and development of appropriate management measures. The emerald ash borer (Agrilus planipennis), a wood‐boring beetle native to South‐East Asia, was first reported in the Great Lakes region during summer 2002. The beetle poses an enormous threat to native ash (Fraxinus) species of North America, as untreated trees in infested areas of Ontario, Michigan and Ohio suffer high mortality. We demonstrate that the borer has spread in North America through a combination of diffusive range extension, associated with local flights, and by long‐distance ‘jump’ dispersal associated with human movement of infested sapling or contaminated firewood. Probability of infestation was inversely related to distance from borer epicentres but positively related to the size of human population centres. At least 9 of 39 populations that were first reported in Michigan during 2004 cannot be accounted for by local diffusion, raising the possibility that other unidentified mechanisms may be contributing to the dispersal of the beetle. In the absence of quarantine, by 2005 all of Michigan's lower peninsula was contained within the boundaries of potential diffusive range expansion. Infested ash saplings also were introduced from Michigan to Maryland during 2003, and subsequently transplanted to five sites in Maryland and Virginia. Quarantine and eradication measures have had mixed results: in the south‐central USA, the species appears on the brink of eradication, whereas its distribution has continued to spread during 2005 in the Great Lakes region despite extensive containment and quarantine measures. Quarantine success in the Great Lakes region is encumbered by multiple dispersal vectors, larger borer population sizes and by the more extensive geographical distribution that was achieved prior to implementation of control measures.
Metformin‐glibenclamide versus metformin plus rosiglitazone in patients with type 2 diabetes inadequately controlled on metformin monotherapy
Authors: Garber A. , Klein E. , Bruce S. , Sankoh S. , Mohideen P. 
Published: December 2005

Aim:  This double‐blind study evaluated the efficacy and safety of metformin‐glibenclamide tablets vs. metformin plus rosiglitazone therapy in patients with type 2 diabetes inadequately controlled on metformin monotherapy.Subjects and methods:  After an open‐label, metformin lead‐in phase, 318 patients were randomly assigned to treatment based on metformin‐glibenclamide 500/2.5 mg tablets (initial daily dose 1000/5 mg) or metformin 500 mg plus rosiglitazone 4 mg (initial daily dose 1000–2000 mg + 4 mg, depending on previous treatment) for 24 weeks. Doses were titrated to achieve the therapeutic glycaemic target. The primary efficacy variable was the change in HbA1C.Results:  At week 24, metformin‐glibenclamide tablets resulted in significantly greater reductions in HbA1C (−1.5%) and fasting plasma glucose [−2.6 mmol/l (−46 mg/dl)] than metformin plus rosiglitazone [−1.1%, p < 0.001; −2 mmol/l (−36 mg/dl), p = 0.03]. More patients receiving metformin‐glibenclamide attained HbA1C <7.0% than did those in the metformin plus rosiglitazone group (60 vs. 47%) and had fasting plasma glucose levels <7 mmol/l (<126 mg/dl) by week 24 (34 vs. 25%). Both treatments were well tolerated. Frequency of adverse gastrointestinal events was comparable between groups. Four per cent of patients receiving metformin‐glibenclamide withdrew because of symptomatic hypoglycaemia contrasted with 3% of patients receiving metformin plus rosiglitazone who withdrew because of persistent hyperglycaemia. Hypoglycaemic events were mild or moderate in intensity and were easily self‐managed.Conclusions:  Metformin‐glibenclamide tablets resulted in significantly greater reductions in HbA1C and fasting plasma glucose compared with metformin plus rosiglitazone in patients with type 2 diabetes inadequately controlled on metformin monotherapy.
Mitigation of establishment of Brassica napus transgenes in volunteers using a tandem construct containing a selectively unfit gene
Authors: Al‐Ahmad Hani , Dwyer Jennice , Moloney Maurice , Gressel Jonathan 
Published: December 2005

SummaryTransgenic oilseed rape (Brassica napus) plants may remain as ‘volunteer’ weeds in following crops, complicating cultivation and contaminating crop yield. Volunteers can become feral as well as act as a genetic bridge for the transfer of transgenes to weedy relatives. Transgenic mitigation using genes that are positive or neutral to the crop, but deleterious to weeds, should prevent volunteer establishment, as previously intimated using a tobacco (Nicotiana tabacum) model. A transgenically mitigated (TM), dwarf, herbicide‐resistant construct using a gibberellic acid‐insensitive (Δgai) gene in the B. napus crop was effective in offsetting the risks of transgene establishment in volunteer populations of B. napus. This may be useful in the absence of herbicide, e.g. when wheat is rotated with oilseed rape. The TM dwarf B. napus plants grown alone had a much higher yield than the non‐transgenics, but were exceedingly unfit in competition with non‐transgenic tall cohorts. The reproductive fitness of TM B. napus was 0% at 2.5‐cm and 4% at 5‐cm spacing between glasshouse‐grown plants relative to non‐transgenic B. napus. Under screen‐house conditions, the reproductive fitness of TM B. napus relative to non‐transgenic B. napus was less than 12%, and the harvest index of the TM plants was less than 40% of that of the non‐transgenic competitors. The data clearly indicate that the Δgai gene greatly enhances the yield in a weed‐free transgenic crop, but the dwarf plants can be eliminated when competing with non‐transgenic cohorts (and presumably other species) when the selective herbicide is not used.
Mitigation using a tandem construct containing a selectively unfit gene precludes establishment of Brassica napus transgenes in hybrids and backcrosses with weedy Brassica rapa
Authors: Al‐Ahmad Hani , Gressel Jonathan 
Published: December 2005

SummaryTransgenic oilseed rape (Brassica napus) plants can interbreed with nearby weedy Brassica rapa, potentially enhancing the weediness and/or invasiveness of subsequent hybrid offspring. We have previously demonstrated that transgenic mitigation effectively reduces the fitness of the transgenic dwarf and herbicide‐resistant B. napus volunteers. We now report the efficacy of such a tandem construct, including a primary herbicide‐resistant gene and a dwarfing mitigator gene, to preclude the risks of gene establishment in the related weed B. rapa and its backcross progeny. The transgenically mitigated and non‐transgenic B. rapa × B. napus interspecific hybrids and the backcrosses (BC1) with B. rapa were grown alone and in competition with B. rapa weed. The reproductive fitness of hybrid offspring progressively decreased with increased B. rapa genes in the offspring, illustrating the efficacy of the concept. The fitness of F2 interspecific non‐transgenic hybrids was between 50% and 80% of the competing weedy B. rapa, whereas the fitness of the comparable T2 interspecific transgenic hybrids was never more than 2%. The reproductive fitness of the transgenic T2 BC1 mixed with B. rapa was further severely suppressed to 0.9% of that of the competing weed due to dwarfism. Clearly, the mitigation technology works efficiently in a rapeseed crop–weed system under biocontainment‐controlled environments, but field studies should further validate its utility for minimizing the risks of gene flow.
Pod shatter‐resistant Brassica fruit produced by ectopic expression of the FRUITFULL gene
Authors: Østergaard Lars , Kempin Sherry A. , Bies Dawn , Klee Harry J. , Yanofsky Martin F. 
Published: December 2005

Summary Arabidopsis has proven to be extremely useful as a reference organism for studies in plant biology, and huge efforts have been employed to unravel various mechanisms of Arabidopsis growth. A major challenge now is to demonstrate that this wealth of knowledge can be used for global agricultural and environmental improvement. Brassica species are closely related to Arabidopsis and represent ideal candidates for model‐to‐crop approaches as they include important crop plants, such as canola. Brassica plants normally disperse their seeds by a pod‐shattering mechanism. Although this mechanism is an advantage in nature, unsynchronized pod shatter constitutes one of the biggest problems for canola farmers. Here, we show that ectopic expression of the Arabidopsis FRUITFULL gene in Brassica juncea is sufficient to produce pod shatter‐resistant Brassica fruit and that the genetic pathway leading to valve margin specification is conserved between Arabidopsis and Brassica. These studies demonstrate a genetic strategy for the control of seed dispersal that should be generally applicable to diverse Brassica crop species to reduce seed loss.
Morphological and habitat evolution in the Cyanobacteria using a compartmentalization approach
Authors: SÁNCHEZ‐BARACALDO P. , HAYES P. K. , BLANK C. E. 
Published: December 2005

ABSTRACTA phylogenomic approach was used to study the evolution of traits in the Cyanobacteria. A cyanobacterial backbone tree was constructed using multiple concatenated sequences from whole genome sequences. Additional taxa were added using a separate alignment that contained morphological characters, SSU (small subunit) and LSU (large subunit) rDNA, rpoC, rpoD, tufA, and gyrB genes. A compartmentalization approach was then used to construct a robust phylogeny with resolved deep branches. Additional morphological characters (e.g. unicellular or filamentous growth, presence or absence of heterocysts) were coded, mapped onto the backbone cyanobacterial tree, and the ancestral character states inferred. Our analyses show that the earliest cyanobacterial lineages were likely unicellular coccoid/ellipsoidal/short rods that lived in terrestrial/freshwater environments. Later cyanobacterial lineages independently gained the ability to colonize brackish, marine, and hypersaline environments while acquiring a large number of more complex traits: sheath, filamentous growth, nitrogen fixation, thermophily, motility, and use of sulphide as an electron donor. Many of these adaptations would have been important in the appearance of dense microbial mats early in Earth's history. Complex traits such as hormogonia, heterocysts, and akinetes had a single ancestor. Within the Nostocales, hormogonia and heterocysts arose before akinetes.
Spatial variations of methanotrophic consortia at cold methane seeps: implications from a high‐resolution molecular and isotopic approach
Authors: ELVERT M. , HOPMANS E. C. , TREUDE T. , BOETIUS A. , SUESS E. 
Published: December 2005

ABSTRACTAnaerobic methane‐oxidizing microbial communities in sediments at cold methane seeps are important factors in controlling methane emission to the ocean and atmosphere. Here, we investigated the distribution and carbon isotopic signature of specific biomarkers derived from anaerobic methanotrophic archaea (ANME groups) and sulphate‐reducing bacteria (SRB) responsible for the anaerobic oxidation of methane (AOM) at different cold seep provinces of Hydrate Ridge, Cascadia margin. The special focus was on their relation to in situ cell abundances and methane turnover. In general, maxima in biomarker abundances and minima in carbon isotope signatures correlated with maxima in AOM and sulphate reduction as well as with consortium biomass. We found ANME‐2a/DSS aggregates associated with high abundances of sn‐2,3‐di‐O‐isoprenoidal glycerol ethers (archaeol, sn‐2‐hydroxyarchaeol) and specific bacterial fatty acids (C16:1ω5c, cyC17:0ω5,6) as well as with high methane fluxes (Beggiatoa site). The low to medium flux site (Calyptogena field) was dominated by ANME‐2c/DSS aggregates and contained less of both compound classes but more of AOM‐related glycerol dialkyl glycerol tetraethers (GDGTs). ANME‐1 archaea dominated deeper sediment horizons at the Calyptogena field where sn‐1,2‐di‐O‐alkyl glycerol ethers (DAGEs), archaeol, methyl‐branched fatty acids (ai‐C15:0, i‐C16:0, ai‐C17:0), and diagnostic GDGTs were prevailing. AOM‐specific bacterial and archaeal biomarkers in these sediment strata generally revealed very similar δ13C‐values of around −100. In ANME‐2‐dominated sediment sections, archaeal biomarkers were even more 13C‐depleted (down to −120), whereas bacterial biomarkers were found to be likewise 13C‐depleted as in ANME‐1‐dominated sediment layers (δ13C: −100). The zero flux site (Acharax field), containing only a few numbers of ANME‐2/DSS aggregates, however, provided no specific biomarker pattern. Deeper sediment sections (below 20 cm sediment depth) from Beggiatoa covered areas which included solid layers of methane gas hydrates contained ANME‐2/DSS typical biomarkers showing subsurface peaks combined with negative shifts in carbon isotopic compositions. The maxima were detected just above the hydrate layers, indicating that methane stored in the hydrates may be available for the microbial community. The observed variations in biomarker abundances and 13C‐depletions are indicative of multiple environmental and physiological factors selecting for different AOM consortia (ANME‐2a/DSS, ANME‐2c/DSS, ANME‐1) along horizontal and vertical gradients of cold seep settings.
Archaeal and bacterial communities in geochemically diverse hot springs of Yellowstone National Park, USA
Authors: MEYER‐DOMBARD D. R. , SHOCK E. L. , AMEND J. P. 
Published: December 2005

ABSTRACTMicrobiological and geochemical surveys were conducted at three hot springs (Obsidian Pool, Sylvan Spring, and ‘Bison Pool’) in Yellowstone National Park (Wyoming, USA). Microbial community structure was investigated by polymerase chain reaction (PCR) amplification of 16S rRNA gene sequences from DNA extracted from sediments of each hot spring, followed by molecular cloning. Both bacterial and archaeal DNA was retrieved from all samples. No Euryarchaea were found, but diverse Crenarchaea exist in all three pools, particularly affiliating with deep‐branching, but uncultivated organisms. In addition, cloned DNA affiliating with the Desulphurococcales and Thermoproteales was identified, but the distribution of taxa differs in each hot spring. The bacterial community at all three locations is dominated by members of the Aquificales and Thermodesulfobacteriales, indicating that the ‘knallgas’ reaction (aerobic hydrogen oxidation) may be a central metabolism in these ecosystems. To provide geochemical context for the microbial community structures, energy‐yields for a number of chemolithoautotrophic reactions are provided for >80 sampling sites in Yellowstone, including Obsidian Pool, Sylvan Spring, and ‘Bison Pool’. This energy profile shows that the knallgas reaction is just one of many exergonic reactions in the Yellowstone hot springs, that energy‐yields for certain reactions can vary substantially from one site to the next, and that few of the demonstrated exergonic reactions are known to support microbial metabolism.
Living under an atomic force microscope
Authors: OBST M. , DITTRICH M. 
Published: December 2005

ABSTRACTAn approach for long‐term in vivo investigations on cyanobacterial cell surface changes at high spatial resolution by Atomic Force Microscopy (AFM) was developed in this study.Until recently, changes of bacterial cell surfaces due to changes of the chemical environment could neither be investigated in situ nor in vivo. However, in vivo investigations give insights into kinetics of cell response to environmental changes and mineral nucleation at the cell's surface. Continuously cultured cyanobacteria of the representative freshwater strain Synechococcus leopoliensis (PCC 7942) were washed and artificially immobilized on poly‐l‐lysine‐coated glass slides. Both immobilization and environmental conditions were optimized in order to facilitate long‐term experiments (> 100 h) with living cells. AFM samples were investigated in situ in two different solutions: Culture medium was used for cultivation experiments and nutrient‐free NaHCO3/CaCl2 solutions (supersaturated with respect to calcite) for long‐term characterizations of the changes in cell surface topography. Cell viability under these conditions was investigated by AFM, TEM and epifluorescence microscopy, independently.No indications for extended starvation were found within the relevant timescales. Analysing the influence of Ca2+ on the surface of S. leopoliensis, we found significant changes compared to a Ca‐free solution. Few hours after CaCl2 was added to the circumfluent solution, small protuberances were observed on the cell surface.These are promising results to environmental scientists for a wide range of applications, as cell response to environmental changes can now be monitored online and in vivo at timescales, which are relevant for natural processes. Most especially studies of biomineralization and mineral nucleation on bacterial cell surfaces will profit from this new approach.
The potential significance of microbial Fe(III) reduction during deposition of Precambrian banded iron formations
Authors: KONHAUSER K. O. , NEWMAN D. K. , KAPPLER A. 
Published: December 2005

ABSTRACTDuring deposition of late Archean–early Palaeoproterozoic Precambrian banded iron formations (BIFs) the downward flux of ferric hydroxide (Fe(OH)3) and phytoplankton biomass should have facilitated microbial Fe(III) reduction. However, quantifying the significance of such a metabolic pathway in the Precambrian is extremely difficult, considering the post‐depositional alteration of the rocks and the lack of ideal modern analogues. Consequently, we have very few constraints on the Fe cycle at that time, namely (i) the concentration of dissolved Fe(II) in the ocean waters; (ii) by what mechanisms Fe(II) was oxidized (chemical, photochemical or biological, the latter using either O2 or light); (iii) where the ferric hydroxide was precipitated (over the shelf vs. open ocean); (iv) the amount of phytoplankton biomass, which relates to the nutrient status of the surface waters; (v) the relative importance of Fe(III) reduction vs. the other types of metabolic pathways utilized by sea floor microbial communities; and (vi) the proportion of primary vs. diagenetic Fe(II) in BIF. Furthermore, although estimates can be made regarding the quantity of reducing equivalents necessary to account for the diagenetic Fe(II) component in Fe‐rich BIF layers, those same estimates do not offer any insights into the magnitude of Fe(III) actually generated within the water column, and hence, the efficiency of Fe and C recycling prior to burial. Accordingly, in this study, we have attempted to model the ancient Fe cycle, based simply on conservative experimental rates of photosynthetic Fe(II) oxidation in the euphotic zone. We estimate here that under ideal growth conditions, as much as 70% of the biologically formed Fe(III) could have been recycled back into the water column via fermentation and organic carbon oxidation coupled to microbial Fe(III) reduction. By comparing the potential amount of biomass generated phototrophically with the reducing equivalents required for Fe(III) reduction and magnetite formation, we also hypothesize that another anaerobic metabolic pathway might have been utilized in the surface sediment to oxidize the fermentation by‐products. Based on the premise that the deep ocean waters were anoxic, this role could have been fulfilled by methanogens, and maybe even methanotrophs that employed Fe(III) reduction.
Epidemiology of Gait Disorders in Community‐Residing Older Adults
Authors: Verghese Joe , LeValley Aaron , Hall Charles B. , Katz Mindy J. , Ambrose Anne F. , Lipton Richard B. 
Published: December 2005

OBJECTIVES:To study the epidemiology of gait disorders in community‐residing older adults and their association with death and institutionalization.DESIGN:Community‐based cohort study.SETTING:Bronx County and the research center at Albert Einstein College of Medicine.PARTICIPANTS:The Einstein Aging study recruited 488 adults aged 70 to 99 between 1999 and 2001. At entry and during annual visits over 5 years, subjects received clinical evaluations to determine presence of neurological or nonneurological gait abnormalities.MEASUREMENTS:Prevalence and incidence of gait disorders based on clinical evaluations and time to institutionalization and death.RESULTS:Of 468 subjects (95.9%) with baseline gait evaluations, 168 had abnormal gaits: 70 neurological, 81 nonneurological, and 17 both. Prevalence of abnormal gait was 35.0% (95% confidence interval (CI)=28.6–42.1). Incidence of abnormal gait was 168.6 per 1,000 person‐years (95% CI=117.4–242.0) and increased with age. Men had a higher incidence of neurological gait abnormalities, whereas women had a higher incidence of nonneurological gaits. Abnormal gaits were associated with greater risk of institutionalization and death (hazard ratio (HR)=2.2, 95% CI=1.5–3.2). The risk was strongly related to severity of impairment; subjects with moderate to severe gait abnormalities (HR=3.2, 95% CI=1.9–5.2) were at higher risk than those with mild gait abnormalities (HR=1.8, 95% CI=1.0–2.8).CONCLUSION:The incidence and prevalence of gait disorders are high in community‐residing older adults and are associated with greater risk of institutionalization and death.
The Effects of a Variant of the Program for All‐inclusive Care of the Elderly on Hospital Utilization and Outcomes
Authors: Kane Robert L. , Homyak Patricia , Bershadsky Boris , Flood Shannon 
Published: December 2005

OBJECTIVES: To compare the effects of the Wisconsin Partnership Program (WPP) on hospital, emergency department (ED), and nursing home utilization with those of traditional care.DESIGN: Quasi‐experimental longitudinal cohort design.SETTING: Selected counties in Wisconsin.PARTICIPANTS: WPP elderly enrollees and two matched control groups consisting of frail older people enrolled in fee‐for‐service insurance plans, Medicare, and Medicaid and receiving home‐ and community‐based waiver services, one from the same geographic area as the WPP and another from a location in the state where the WPP was not offered.MEASUREMENTS: Data came from administrative records. Regression and survival analyses were adjusted for case‐mix variables.RESULTS: No significant differences in hospital utilization, ED visits, preventable hospitalizations, risk of entry into nursing homes, or mortality were found. WPP enrollees had more contact with care providers than did controls.CONCLUSION: WPP did not dramatically alter the pattern of care. Part of the weak effect may be attributable to the small numbers of WPP cases per participating physician.