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1.
Front Digit Health ; 5: 1066327, 2023.
Article in English | MEDLINE | ID: mdl-36937251

ABSTRACT

Background: There is limited literature on security and access for social care settings despite policy highlighting importance, and no published research exploring facial recognition lock technology (FRLT) for potential improvements. This study explored FRLT device implementation, use, barriers and benefits. Methods: One residential care home with 43 older adults and 68 staff members (Site A), and one supported living facility caring for six individuals with mental health issues with 18 staff members (Site B) were provided with FRLT for six months. Nine pre-implementation staff interviews explored existing access and security perceptions. Ten post-implementation staff interviews and one staff focus group were conducted; all were analysed using content analysis to understand, alongside process mapping, the use and impact of the FRLT. Interview participants included site care staff and other visiting healthcare professionals. We additionally report feedback from the technology developers to demonstrate impact of industry-academia collaboration. Results: Pre-implementation interviews highlighted issues with current pin-pad or lock-box systems, including; code sharing; code visibility, ineffective code changes, security issues following high staff turnover, lack of efficiency for visitors including NHS staff and lack of infection control suggesting requirement for innovation and improvement. Pre-implementation interviews showed openness and interest in FRLT, although initial queries were raised around cost effectiveness and staff skills. Following implementation, good levels of adoption were achieved with 72% and 100% (49/68 and 18/18) of staff members uploading their face at the two sites, and 100% of residents at Site B using the system (6/6). Additionally, Site B made a positive procurement decision and continues to discuss wider rollout. Post implementation interviews suggested FRLT was useful and acceptable for improving security and access. Benefits identified included staff/visitor time saving, enhanced security, team ease of access, resident autonomy and fewer shared touch points. Integration was suggested including with fire alarm systems, staff clocking in/out, and Covid monitoring to improve usefulness. The developers have since responded to feedback with design iterations. Conclusion: We identified concerns on security and access in social care settings, which warrant further exploration and research. FRLT could increase resident autonomy and reduce staff burden, particularly considering frequent multi-agency health and care visits.

2.
Ann R Coll Surg Engl ; 97(4): 255-8, 2015 May.
Article in English | MEDLINE | ID: mdl-26263930

ABSTRACT

INTRODUCTION: Inferior epigastric artery (IEA) pseudoaneurysms are recognised complications of abdominal wall procedures, and a variety of approaches including surgical excision and ligation, percutaneous procedures and conservative management have been employed in treating this rare complication. METHODS: We describe a case of an IEA pseudoaneurysm diagnosed on computed tomography (CT) angiography, 14 days following a laparoscopic assisted low anterior resection, which was managed successfully with surgical excision and ligation. A review of the literature identified 32 reports of this complication since 1973 with 69% of cases occurring since 2000. FINDINGS: The main aetiology of IEA pseudoaneurysm was abdominal surgery (n=20); 65% of cases were attributable to abdominal wound closure or laparoscopic surgery. Two-thirds (66%) of patients presented between 11 and 63 days, and all except 1 case presented with discomfort, abdominal mass or haemodynamic instability. Colour Doppler ultrasonography was the imaging modality of choice (n=18), either alone or in combination with computed tomography and/or angiography. Surgical ligation and excision and percutaneous coil embolisation formed the mainstay of attempted treatments (69%), particularly following treatment failure using an alternative technique. CONCLUSIONS: The incidence of iatrogenic IEA pseudoaneurysms appears to be increasing. Awareness of this rare complication is of clinical importance to avoid excessive morbidity for affected individuals.


Subject(s)
Aneurysm, False , Epigastric Arteries , Laparoscopy/adverse effects , Postoperative Complications , Aneurysm, False/diagnostic imaging , Aneurysm, False/pathology , Aneurysm, False/surgery , Epigastric Arteries/diagnostic imaging , Epigastric Arteries/pathology , Epigastric Arteries/surgery , Humans , Postoperative Complications/diagnostic imaging , Postoperative Complications/pathology , Postoperative Complications/surgery , Tomography, X-Ray Computed
3.
Indian J Surg ; 77(6): 495-501, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26884657

ABSTRACT

Axillary lymph node status is a prognostic marker in breast cancer management, and axillary surgery plays an important role in staging and local control. This study aims to assess whether a combination of sentinel lymph node biopsy (SLNB) using patent blue dye and axillary node sampling (ANS) offers equivalent identification rate to dual tracer technique. Furthermore, we aim to investigate whether there are any potential benefits to this combined technique. Retrospective study of 230 clinically node-negative patients undergoing breast-conserving surgery for single T1-T3 tumours between 2006 and 2011. Axillae were staged using a combined blue dye SLNB/ANS technique. SLNs were localized in 226/230 (identification rate 98.3 %). Three of one hundred ninety-two patients with a negative SLN were found to have positive ANS nodes and 1/4 failed SLNB patients had positive ANS nodes. Thirty-four of two hundred twenty-six patients had SLN metastases and 11/34 (32.4 %) also had a positive non-sentinel lymph node on ANS. Twenty-one of twenty-four (87.5 %) node-positive T1 tumours had single node involvement. Nine of thirty-eight node-positive patients progressed to completion axillary clearance (cALND), and the rest were treated with axillary radiotherapy. Axillary recurrence was nil at median 5 year follow-up. Complementing SLNB with axillary node sampling (ANS) decreases the unavoidable false-negative rate associated with SLNB. Appropriate operator experience and technique can result in an SLN localization rate of 98 %, rivalling a dual tracer technique. The additional insight offered by ANS into the status of non-sentinel nodes has potential applications in an era of less frequent cALND.

4.
Geobiology ; 12(2): 146-56, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24428517

ABSTRACT

Iron (Fe)-oxidizing bacteria have the potential to produce morphologically unique structures that may be used as biosignatures in geological deposits. One particular example is Mariprofundus ferrooxydans, which produces extracellular twisted ribbon-like stalks consisting of ferrihydrite, co-located with organic and inorganic elements. It is currently thought that M. ferrooxydans excrete and co-precipitate polysaccharides and Fe simultaneously; however, the cellular production of these polysaccharides has yet to be confirmed. Here, we report on a time-series study that used scanning transmission X-ray microscopy and C 1s and Ca 2p near-edge X-ray adsorption fine structure spectroscopy to investigate production of polysaccharides over the growth cycle of M. ferrooxydans. The production and morphology of twisted iron stalks were consistent with previous observations, but unexpectedly, in the log phase, the carbon content of the stalks was extremely low. It was not until stationary growth phase that a significant component of carbon was detected on the stalks. During the log phase, low levels of carbon, only detectable when the stalks were thin, suggested that M. ferrooxydans produce an extracellular polysaccharide template onto which the Fe precipitates. By stationary phase, the increased carbon association with the stalks was a result of adsorption of organic compounds that were released during osmotic shock post-stalk production. In the environment, elevated concentrations of DOC could adsorb onto the Fe stalks as well as a number of other elements, for example, Si, P, Ca, which, by preventing chemical interactions between the Fe nanoparticles, will prevent structural deformation during recrystallization and preserve the structure of these filaments in the rock record.


Subject(s)
Ferric Compounds/metabolism , Iron/metabolism , Polysaccharides/metabolism , Proteobacteria/metabolism , Carbon/metabolism , Microscopy, Electron, Scanning Transmission , Oxidation-Reduction , X-Ray Absorption Spectroscopy
6.
Geobiology ; 10(2): 178-92, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22221398

ABSTRACT

We deployed sediment traps adjacent to two active hydrothermal vents at 9°50'N on the East Pacific Rise (EPR) to assess the variability in bacterial community structure associated with plume particles on the timescale of weeks to months, to determine whether an endemic population of plume microbes exists, and to establish ecological relationships between bacterial populations and vent chemistry. Automated rRNA intergenic spacer analysis (ARISA) indicated that there are separate communities at the two different vents and temporal community variations between each vent. Correlation analysis between chemistry and microbiology indicated that shifts in the coarse particulate (>1 mm) Fe/(Fe+Mn+Al), Cu, V, Ca, Al, (232) Th, and Ti as well as fine-grained particulate (<1 mm) Fe/(Fe+Mn+Al), Fe, Ca, and Co are reflected in shifts in microbial populations. 16S rRNA clone libraries from each trap at three time points revealed a high percentage of Epsilonproteobacteria clones and hyperthermophilic Aquificae. There is a shift toward the end of the experiment to more Gammaproteobacteria and Alphaproteobacteria, many of whom likely participate in Fe and S cycling. The particle-attached plume environment is genetically distinct from the surrounding seawater. While work to date in hydrothermal environments has focused on determining the microbial communities on hydrothermal chimneys and the basaltic lavas that form the surrounding seafloor, little comparable data exist on the plume environment that physically and chemically connects them. By employing sediment traps for a time-series approach to sampling, we show that bacterial community composition on plume particles changes on timescales much shorter than previously known.


Subject(s)
Bacteria/classification , Hydrothermal Vents/microbiology , Seawater/microbiology , Bacteria/genetics , Biodiversity , Cloning, Molecular , DNA, Bacterial/analysis , DNA, Bacterial/genetics , DNA, Bacterial/isolation & purification , Ecosystem , Epsilonproteobacteria/classification , Epsilonproteobacteria/genetics , Gammaproteobacteria/classification , Gammaproteobacteria/genetics , Gene Library , Hydrothermal Vents/chemistry , Molecular Sequence Data , Phylogeny , RNA, Ribosomal, 16S/genetics , Seawater/chemistry , Sequence Analysis, DNA , Time Factors
8.
Geobiology ; 6(3): 309-17, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18452538

ABSTRACT

Thanks to the work of Terrance J. Beveridge and other pioneers in the field of metal-microbe interactions, prokaryotes are well known to sequester metals and other ions intracellularly in various forms. These forms range from poorly ordered deposits of metals to well-ordered mineral crystals. Studies on well-ordered crystalline structures have generally focused on intracellular organelles produced by magnetotactic bacteria that are ubiquitous in terrestrial and marine environments that precipitate Fe(3)O(4) or Fe(3)S(4), Fe-bearing minerals that have magnetic properties and are enclosed in intracellular membranes. In contrast, studies on less-well ordered minerals have focused on Fe-, As-, Mn-, Au-, Se- and Cd-precipitates that occur intracellularly. The biological and environmental function of these particles remains a matter of debate.


Subject(s)
Metals, Heavy/analysis , Minerals/analysis , Prokaryotic Cells/chemistry , Soil Microbiology , Microscopy, Electron , Prokaryotic Cells/ultrastructure
9.
J Evol Biol ; 21(4): 1125-32, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18422531

ABSTRACT

The army ant Eciton burchellii is probably the most important arthropod predator in the Neotropics, and many animal species depend upon it. Sex-biased dispersal with winged males and permanently wingless queens may render this species especially sensitive to habitat fragmentation and natural barriers, which might have severe impacts on population structure and lead to population decline. Using nuclear microsatellite markers and mitochondrial sequences, we investigated genetic differentiation in a fragmented population in the Panama Canal area. While nuclear markers showed little differentiation between subpopulations (F(ST) = 0.017), mitochondrial differentiation was maximal in some cases (Phi(ST) = 1). This suggests that, while females are not capable of crossing barriers such as large rivers, flying males are able to promote nuclear gene flow between the studied forest patches. Consistent with this interpretation, we did not find any evidence for inbreeding or genetic deterioration on Barro Colorado Island over the last 90 years since its formation.


Subject(s)
Ants/physiology , Animals , Female , Male , Panama , Population Dynamics , Predatory Behavior
10.
Ann Bot ; 101(6): 845-53, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18281692

ABSTRACT

BACKGROUND AND AIMS: Perennial ryegrass (Lolium perenne) is one of the key forage and amenity grasses throughout the world. In the UK it accounts for 70 % of all agricultural land use with an estimated farm gate value of 6 billion pounds per annum. However, in terms of the genetic resources available, L. perenne has lagged behind other major crops in Poaceae. The aim of this project was therefore the construction of a microsatellite-enriched genomic library for L. perenne to increase the number of genetic markers available for both marker-assisted selection in breeding programmes and gene isolation. METHODS: Primers for 229 non-redundant microsatellite markers were designed and used to screen two L. perenne genotypes, one amenity and one forage. Of the 229 microsatellites, 95 were found to show polymorphism between amenity and forage genotypes. A selection of microsatellite primers was selected from these 95 and used to screen two mapping populations derived from intercrossing and backcrossing the two forage and amenity grass genotypes. KEY RESULTS AND CONCLUSIONS: The utility of the resulting genetic maps for analysis of the genetic control of target traits was demonstrated by the mapping of genes associated with heading date to linkage groups 4 and 7.


Subject(s)
Genome, Plant , Lolium/genetics , Microsatellite Repeats/genetics , Base Sequence , DNA Primers
11.
Immunology ; 123(2): 181-6, 2008 Feb.
Article in English | MEDLINE | ID: mdl-17903204

ABSTRACT

In the accepted model of lymphocyte intestinal homing, naïve T cells recirculate via organized lymphoid tissues, whilst induced effector/memory cells home to the intestinal mucosa. In order to assess the T-cell-receptor repertoire in the intestine and gut-associated lymphoid tissue (GALT), spectratyping was performed on the proximal and the distal intestine, spleen and mesenteric lymph node tissue from six PVG rats. The products were analysed with an automated sequencer and statistical analyses were performed with hierarchical cluster analysis. This demonstrated the presence of a restricted T-cell repertoire in the small intestine compared with that in the mesenteric lymph nodes and the spleen. It also demonstrated marked differences in repertoire between individual, fully inbred rats maintained under apparently identical conditions in the same cage and fed identical diets. In addition, this work demonstrated marked differences between repertoires in the proximal and the distal intestine. Such marked differences are likely to reflect the end result of increasing divergence over time produced by relatively subtle effects of environment and antigenic load. Equally, marked differences in repertoire between small intestinal segments within individual rats indicate selective recruitment or retention of specific clones, presumably antigen-driven.


Subject(s)
Intestinal Mucosa/immunology , Intestine, Small/immunology , Receptors, Antigen, T-Cell, alpha-beta/analysis , T-Lymphocyte Subsets/immunology , Animals , Antigen Presentation/immunology , Cluster Analysis , Immunity, Mucosal , Lymph Nodes/immunology , Male , Polymerase Chain Reaction/methods , Rats , Rats, Inbred Strains , Spleen/immunology
12.
Appl Environ Microbiol ; 70(10): 6230-9, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15466570

ABSTRACT

The occurrence and distribution of magnetotactic bacteria (MB) were studied as a function of the physical and chemical conditions in meromictic Salt Pond, Falmouth, Mass., throughout summer 2002. Three dominant MB morphotypes were observed to occur within the chemocline. Small microaerophilic magnetite-producing cocci were present at the top of the chemocline, while a greigite-producing packet-forming bacterium occurred at the base of the chemocline. The distributions of these groups displayed sharp changes in abundance over small length scales within the water column as well as strong seasonal fluctuations in population abundance. We identified a novel, greigite-producing rod in the sulfidic hypolimnion that was present in relatively constant abundance over the course of the season. This rod is the first MB that appears to belong to the gamma-Proteobacteria, which may suggest an iron- rather than sulfur-based respiratory metabolism. Its distribution and phylogenetic identity suggest that an alternative model for the ecological and physiological role of magnetotaxis is needed for greigite-producing MB.


Subject(s)
Fresh Water/microbiology , Gram-Negative Bacteria/isolation & purification , Magnetics , Seawater/microbiology , DNA, Bacterial/genetics , DNA, Ribosomal/genetics , Ferrosoferric Oxide , Gram-Negative Bacteria/classification , Gram-Negative Bacteria/genetics , Gram-Negative Bacteria/physiology , Iron , Marine Biology , Massachusetts , Molecular Sequence Data , Movement , Oxides , Phylogeny , Seasons , Sodium Chloride , Sulfides
13.
Insect Mol Biol ; 13(4): 413-21, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15271214

ABSTRACT

Phyllodecta (= Phratora) vulgatissima and P. vitellinae (Coleoptera: Chrysomelidae) are important pests of willows and poplars. Their differences in host species preference may provide a non-chemical control strategy for pest control. However, little is known about population structure with respect to hosts, regions or seasons. Using five microsatellites, 850 P. vulgatissima and 1100 P. vitellinae individuals, comprising 17 and 22 UK samples, respectively, were genotyped. High diversity was observed at all loci. Migrant numbers exchanged per generation (Nm) were high (2.1-12.6 for P. vulgatissima and 0.9-12.2 for P. vitellinae), suggesting high genetic exchange between samples. Estimates of population differentiation (FST) and analyses of the data using Bayesian methods (Partition and Structure) showed little evidence of subdivision in relation to geography, sampling time or host.


Subject(s)
Coleoptera/genetics , Coleoptera/physiology , Genetic Variation , Genetics, Population , Salix , Animals , Bayes Theorem , Gene Frequency , Genotype , Geography , Microsatellite Repeats/genetics , Population Dynamics , United Kingdom
14.
Theor Appl Genet ; 108(6): 1103-12, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15067397

ABSTRACT

A set of 398 simple sequence repeat markers (SSRs) have been developed and characterised for use with genetic studies of Brassica species. Small-insert (250-900 bp) genomic libraries from Brassica rapa, B. nigra, B. oleracea and B. napus, highly enriched for dinucleotide and trinucleotide SSR motifs, were constructed. Screening the clones with a mixture of oligonucleotide repeat probes revealed positive hybridisation to between 75% and 90% of the clones. Of these, 1230 were sequenced. Primer pairs were designed for 398 SSR clones, and of these, 270 (67.8%) amplified a PCR product of the expected size in their focal and/or closely related species. A further screen of 138 primers pairs that produced a PCR product in B. napus germplasm found that 86 (62.3%) revealed length polymorphisms within at least one line of a test array representing the four Brassica species. The results of this screen were used to identify 56 SSRs and were combined with 41 SSRs that had previously shown polymorphism between the parents of a B. napus mapping population. These 97 SSR markers were mapped relative to a framework of RFLP markers and detected 136 loci over all 19 linkage groups of the oilseed rape genome.


Subject(s)
Brassica/genetics , Chromosome Mapping , Hybridization, Genetic , Microsatellite Repeats/genetics , Crosses, Genetic , Genomic Library , Oligonucleotide Probes , Plasmids/genetics , Polymorphism, Genetic , Polymorphism, Restriction Fragment Length , Sequence Analysis, DNA
15.
Theor Appl Genet ; 108(5): 864-72, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14605808

ABSTRACT

We have constructed a framework linkage map based on microsatellite markers for Vitis vinifera L., the European wine grape. The mapping population consisted of 153 progeny plants from a cross of Vitis vinifera cvs. Riesling x Cabernet Sauvignon. One hundred fifty-two microsatellite markers and one polymorphic EST marker have been mapped to 20 linkage groups (2 n=38). The map covers 1,728 cM with an average distance between markers of 11.0 cM. Estimates of genome size, expected genome coverage, and observed genome coverage were determined with 135-140 markers. Genome length estimates differed between paternal and maternal data sets. Observed approximate genome coverage was 65% versus an expected coverage of 90%. Meiotic recombination rates were not significantly different between maternal and paternal parents. This map has been adopted as a reference map for the International Grape Genome Program.


Subject(s)
Genetic Linkage , Microsatellite Repeats/genetics , Vitis/genetics , Genetic Markers , Genome, Plant , Meiosis/genetics , Polymerase Chain Reaction , Polymorphism, Genetic , Recombination, Genetic
16.
Theor Appl Genet ; 108(5): 873-80, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14625671

ABSTRACT

Twenty-two highly variable SSR markers were developed in Douglas-fir [ Pseudotsuga menziesii (Mirb.) Franco] from five SSR-enriched genomic libraries. Fifteen PCR primer pairs amplified a single codominant locus, while seven primer pairs occasionally amplified two loci. The Mendelian inheritance of all 22 SSRs was confirmed via segregation analyses in several Douglas-fir families. The mean observed heterozygosity and the mean number of alleles per locus were 0.855 (SE=0.020) and 23 (SE=1.6), respectively. Twenty markers were used in genetic linkage analysis and mapped to ten known linkage groups. Because of their high polymorphism and unambiguous phenotypes, 15 single-locus markers were selected as the most suitable for DNA fingerprinting and parentage analysis. Only three SSRs were sufficient to achieve an average probability of exclusion from paternity of 0.998 in a Douglas-fir seed orchard block consisting of 59 parents.


Subject(s)
Genetic Markers , Trees/genetics , Base Sequence , DNA Primers , Heterozygote , Phenotype , Polymorphism, Genetic
17.
Theor Appl Genet ; 108(3): 501-15, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14574452

ABSTRACT

A full-sibling F1 population comprising 153 individuals from the cross of 'Regent' x 'Lemberger' was employed to construct a genetic map based on 429 molecular markers. The newly-bred red grapevine variety 'Regent' has multiple field-resistance to fungal diseases inherited as polygenic traits, while 'Lemberger' is a traditional fungus-susceptible cultivar. The progeny segregate quantitatively for resistances to Plasmopara viticola and Uncinula necator, fungal pathogens that threaten viticulture in temperate areas. A double pseudo-testcross strategy was employed to construct the two parental maps under high statistical stringency for linkage to obtain a robust marker frame for subsequent quantitative trait locus (QTL) analysis. In total, 185 amplified fragment length polymorphism, 137 random amplified polymorphic DNA, 85 single sequence repeat and 22 sequence characterized amplified region or cleaved amplified polymorphic sequence markers were mapped. The maps were aligned by co-dominant or doubly heterozygous dominant anchor markers. Twelve pairs of homologous linkage groups could be integrated into consensus linkage groups. Resistance phenotypes and segregating characteristics were scored as quantitative traits in three or four growing seasons. Interval mapping reproducibly localized genetic factors that correlated with fungal disease resistances to specific regions on three linkage groups of the maternal 'Regent' map. A QTL for resistance to Uncinula necator was identified on linkage group 16, and QTLs for endurance to Plasmopara viticola on linkage groups 9 and 10 of 'Regent'. Additional QTLs for the onset of berry ripening ("veraison"), berry size and axillary shoot growth were identified. Berry color segregated as a simple trait in this cross of two red varieties and was mapped as a morphological marker. Six markers derived from functional genes could be localized. This dissection of polygenic fungus disease resistance in grapevine allows the development of marker-assisted selection for breeding, the characterization of genetic resources and the isolation of the corresponding genes.


Subject(s)
Chromosome Mapping , Crosses, Genetic , Immunity, Innate/genetics , Quantitative Trait Loci/genetics , Vitis/genetics , DNA Primers , Genetic Markers , Minisatellite Repeats , Mycoses/genetics , Phenotype , Polymorphism, Restriction Fragment Length , Random Amplified Polymorphic DNA Technique
18.
Theor Appl Genet ; 106(7): 1213-24, 2003 May.
Article in English | MEDLINE | ID: mdl-12748772

ABSTRACT

Two linkage maps for grape (Vitis spp.) have been developed based on 81 F(1) plants derived from an interspecific cross between the wine cultivar Moscato bianco (Vitis vinifera L.) and a Vitis riparia Mchx. accession, a donor of pathogen resistance traits. The double pseudotest-cross mapping strategy was applied using three types of molecular markers. The efficiency of SSRs to anchor homologous linkage groups from different Vitis maps and the usefulness of AFLPs in saturating molecular linkage maps were evaluated. Moreover, the SSCP technique was developed based on sequence information in public databases concerning genes involved in flavonoid and stilbene biosynthesis. For the maternal genetic map a total of 338 markers were assembled in 20 linkage groups covering 1,639 cM, whereas 429 loci defined the 19 linkage groups of the paternal map which covers 1,518 cM. The identification of 14 linkage groups common to both maps was possible based on 21 SSR and 19 AFLP loci. The position of SSR loci in the maps presented here was consistent with other published mapping experiments in Vitis.


Subject(s)
Genetic Linkage , Vitis/genetics , Base Sequence , DNA Primers , Polymorphism, Single-Stranded Conformational , Species Specificity
19.
Appl Environ Microbiol ; 69(5): 2906-13, 2003 May.
Article in English | MEDLINE | ID: mdl-12732565

ABSTRACT

We report the isolation and physiological characterization of novel, psychrophilic, iron-oxidizing bacteria (FeOB) from low-temperature weathering habitats in the vicinity of the Juan de Fuca deep-sea hydrothermal area. The FeOB were cultured from the surfaces of weathered rock and metalliferous sediments. They are capable of growth on a variety of natural and synthetic solid rock and mineral substrates, such as pyrite (FeS(2)), basalt glass ( approximately 10 wt% FeO), and siderite (FeCO(3)), as their sole energy source, as well as numerous aqueous Fe substrates. Growth temperature characteristics correspond to the in situ environmental conditions of sample origin; the FeOB grow optimally at 3 to 10 degrees C and at generation times ranging from 57 to 74 h. They are obligate chemolithoautotrophs and grow optimally under microaerobic conditions in the presence of an oxygen gradient or anaerobically in the presence of nitrate. None of the strains are capable of using any organic or alternate inorganic substrates tested. The bacteria are phylogenetically diverse and have no close Fe-oxidizing or autotrophic relatives represented in pure culture. One group of isolates are gamma-Proteobacteria most closely related to the heterotrophic bacterium Marinobacter aquaeolei (87 to 94% sequence similarity). A second group of isolates are alpha-Proteobacteria most closely related to the deep-sea heterotrophic bacterium Hyphomonas jannaschiana (81 to 89% sequence similarity). This study provides further evidence for the evolutionarily widespread capacity for Fe oxidation among bacteria and suggests that FeOB may play an unrecognized geomicrobiological role in rock weathering in the deep sea.


Subject(s)
Alphaproteobacteria/isolation & purification , Alphaproteobacteria/metabolism , Gammaproteobacteria/isolation & purification , Gammaproteobacteria/metabolism , Iron/metabolism , Seawater/microbiology , Alphaproteobacteria/genetics , Carbon/metabolism , Gammaproteobacteria/genetics , Geologic Sediments/microbiology , Microelectrodes , Oxidation-Reduction , Oxygen/metabolism , Pacific Ocean , Phylogeny , Temperature
20.
Theor Appl Genet ; 106(6): 1091-101, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12671758

ABSTRACT

To assess the potential of multiplex SSR markers for testing distinctness, uniformity and stability of rape (Brassica napus L.) varieties, we developed three multiplex SSR sets composed of five markers each. These were used to measure the extent of diversity within and between a set of ten varieties using a fluorescence-based semi-automated detection technology. Also, we evaluated the significance of any correlation between SSRs, pedigree and five of the morphological characters currently used for statutory distinctness, uniformity and stability testing of rape varieties. An assignment test was allowed to identify 99% of the plants examined, with the correct variety based on the analysis of 48 individual plants for each variety. Principal coordinate analysis confirmed that a high degree of separation between varieties could be achieved. Varieties were separated in three groups corresponding to winter, spring and forage types. These results suggested that it should be possible to select a set of markers for obtaining a suitable separation. Diversity within varieties varied considerably, according to the variety and the locus examined. No significant correlation was found between SSR and morphological data. However, genetic distances measured by SSRs were correlated to pedigree. These results suggested that SSRs could be used for pre-screening or grouping of existing and candidate varieties, allowing the number of varieties that need to be grown for comparison to be reduced. Multiplex SSR sets gave high-throughput reproducible results, thus reducing the costs of SSR assessment. Multiplex SSR sets are a promising way forward for complementing the current variety testing system in B. napus.


Subject(s)
Brassica napus/genetics , Minisatellite Repeats , Brassica napus/classification , Genetic Markers , Genetic Variation
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