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Broad Diversity (broad + diversity)
Selected AbstractsA Broad Diversity of Volatile Carboxylic Acids, Released by a Bacterial Aminoacylase from Axilla Secretions, as Candidate Molecules for the Determination of Human-Body Odor TypeCHEMISTRY & BIODIVERSITY, Issue 1 2006Andreas Natsch Abstract Human body odor is to a large part determined by secretions of glands in the axillary regions. Two key odoriferous principles, 3-methylhex-2-enoic acid (3MH2; 4/5) and 3-hydroxy-3-methylhexanoic acid (HMHA; 6) have been shown to be released from glutamine conjugates secreted in the axilla by a specific N, -acyl-glutamine aminoacylase (N-AGA) obtained from axilla isolates of Corynebacteria sp. However, the low number of different odorants reported in humans stands in contrast to the observed high inter-individual variability in body odors. Axilla secretions of individual donors were, therefore, analyzed in detail. The secretions were treated with N-AGA, analyzed by GC/MS, and compared to undigested controls. Over 28 different carboxylic acids were released by this enzyme from odorless axilla secretions (Table,1). Many of these body odorants have not been reported before from a natural source, and they include several aliphatic 3-hydroxy acids with 4-Me branches, 3,4-unsaturated, 4-Et-branched aliphatic acids, and a variety of degradation products of amino acids. The odor threshold of some of the acids was found to be in the range of 1,ng. Most of these compounds were present in all donors tested, but in highly variable relative amounts, and they are, thus, candidate molecules as key components of a ,compound odor' determining the individual types of human body odor. [source] Skeletal elements in the vertebrate eye and adnexa: Morphological and developmental perspectivesDEVELOPMENTAL DYNAMICS, Issue 5 2006Tamara A. Franz-Odendaal Abstract Although poorly appreciated, the vertebrate eye and adnexa are relatively common sites for skeletogenesis. In many taxa, the skeleton contributes to internal reinforcement in addition to the external housing of the eye (e.g., the circumorbital bones and eyelids). Eyeball elements such as scleral cartilage and scleral ossicles are present within a broad diversity of vertebrates, albeit not therian mammals, and have been used as important models for the study of condensations and epithelial,mesenchymal interactions. In contrast, other elements invested within the eye or its close surroundings remain largely unexplored. The onset and mode of development of these skeletal elements are often variable (early versus late; involving chondrogenesis, osteogenesis, or both), and most (if not all) of these elements appear to share a common neural crest origin. This review discusses the development and distribution of the skeletal elements within and associated with the developing eye and comments on homology of the elements where these are questionable. Developmental Dynamics 235:1244,1255, 2006. © 2006 Wiley-Liss, Inc. [source] Freshwater selenium-methylating bacterial thiopurine methyltransferases: diversity and molecular phylogenyENVIRONMENTAL MICROBIOLOGY, Issue 2 2005S. Favre-Bonté Summary The diversity of bacterial thiopurine methyltransferases (bTPMT) among five natural Se-methylating freshwaters was investigated by polymerase chain reaction (PCR) screenings and sequencings. DNA sequence analyses confirmed the cloned products' identity and revealed a broad diversity of freshwater TPMTs. Neighbour-joining (NJ) phylogenetic analyses combining these sequences, all GenBank entries closely related to these sequences and deduced TPMTs obtained in this work from selected ,-proteobacteria showed TPMTs to form a distinct radiation, closely related to UbiG methyltransferases. Inside the TPMT phylogenetic cluster, eukaryote sequences diverged early from the bacterial ones, and all the bacterial database entries belonged to a subgroup of ,-proteobacteria, with an apparent lateral transfer of a particular allele to ,-proteobacteria of Bordetella. The NJ phylogenetic tree revealed 22 bTPMT lineages, 10 of which harboured freshwater sequences. All lineages showed deep and long branches indicative of major genetic drifts outside regions encoding highly conserved domains. Selected residues among these highly variable domains could reflect adaptations for particular ecological niches. PCR lineage-specific primers differentiated Se-methylating freshwaters according to their ,tpm lineage' signatures. Most freshwater tpm alleles were found to be distinct from those available in the databases, but a group of tpm was found encoding TPMTs identical to an Aeromonas veronii TPMT characterized in this work. [source] Toll-like receptors' two-edged sword: when immunity meets apoptosisEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2007Bruno Salaun Abstract Toll-like receptors (TLR) have emerged as key players in the detection of pathogens and the induction of anti-microbial immune response. TLR recognize pathogen-associated molecular patterns, and trigger anti-microbial innate immune responses ranging from the secretion of pro-inflammatory mediators to the increase of natural killer cell cytotoxicity. Besides activating the innate immune response, TLR engagement also shapes the adaptive immune response. Indeed, the broad diversity of signaling pathways initiated by TLR is progressively unraveled. Recent reports suggested that among the anti-microbial defenses they initiate, members of the TLR family can induce apoptosis. This review focuses on this newly described function of TLR, and emphasizes the similarities and differences between the different apoptosis-signaling pathways described downstream of TLR. The functional relevance of TLR-triggered apoptosis is also discussed, as therapeutic applications are likely to ensue in the near future. [source] Molecular bacterial community analysis of clean rooms where spacecraft are assembledFEMS MICROBIOLOGY ECOLOGY, Issue 3 2007Christine Moissl Abstract Molecular bacterial community composition was characterized from three geographically distinct spacecraft-associated clean rooms to determine whether such populations are influenced by the surrounding environment or the maintenance of the clean rooms. Samples were collected from facilities at the Jet Propulsion Laboratory (JPL), Kennedy Space Flight Center (KSC), and Johnson Space Center (JSC). Nine clone libraries representing different surfaces within the spacecraft facilities and three libraries from the surrounding air were created. Despite the highly desiccated, nutrient-bare conditions within these clean rooms, a broad diversity of bacteria was detected, covering all the main bacterial phyla. Furthermore, the bacterial communities were significantly different from each other, revealing only a small subset of microorganisms common to all locations (e.g. Sphingomonas, Staphylococcus). Samples from JSC assembly room surfaces showed the greatest diversity of bacteria, particularly within the Alpha - and Gammaproteobacteria and Actinobacteria. The bacterial community structure of KSC assembly surfaces revealed a high presence of proteobacterial groups, whereas the surface samples collected from the JPL assembly facility showed a predominance of Firmicutes. Our study presents the first extended molecular survey and comparison of NASA spacecraft assembly facilities, and provides new insights into the bacterial diversity of clean room environments . [source] The volatile constituents of frankincense , a reviewFLAVOUR AND FRAGRANCE JOURNAL, Issue 6 2009Michaela Mertens Abstract The smell of frankincense resin and powder, as well as burned frankincense, has been linked to a series of health effects since ancient times. Additionally, frankincense and its fumes are used as a means to induce positive psychophysical effects and well-being, not only in an ecclesiastical setting but also in traditional medical applications. This review aims to provide an overview of current knowledge of the volatile constituents of frankincense, with explicit consideration concerning the diverse Boswellia varieties. Altogether, more than 300 volatiles in frankincense have been reported in the literature. In particular, a broad diversity has been found in the qualitative and quantitative composition of the volatiles with respect to different varieties of Boswellia. A detailed discussion of the various analytical approaches applied to isolating and analysing the volatile fractions of frankincense is also presented. Copyright © 2009 John Wiley & Sons, Ltd. [source] The utilization of e-government services: citizen trust, innovation and acceptance factors,INFORMATION SYSTEMS JOURNAL, Issue 1 2005Lemuria Carter Abstract. Electronic government, or e-government, increases the convenience and accessibility of government services and information to citizens. Despite the benefits of e-government , increased government accountability to citizens, greater public access to information and a more efficient, cost-effective government , the success and acceptance of e-government initiatives, such as online voting and licence renewal, are contingent upon citizens' willingness to adopt this innovation. In order to develop ,citizen-centred' e-government services that provide participants with accessible, relevant information and quality services that are more expedient than traditional ,brick and mortar' transactions, government agencies must first understand the factors that influence citizen adoption of this innovation. This study integrates constructs from the Technology Acceptance Model, Diffusions of Innovation theory and web trust models to form a parsimonious yet comprehensive model of factors that influence citizen adoption of e-government initiatives. The study was conducted by surveying a broad diversity of citizens at a community event. The findings indicate that perceived ease of use, compatibility and trustworthiness are significant predictors of citizens' intention to use an e-government service. Implications of this study for research and practice are presented. [source] Characterization of lactic acid bacteria strains on the basis of neutral volatile compounds produced in wheyJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2001G. Mauriello G. MAURIELLO, L. MOIO, G. MOSCHETTI, P. PIOMBINO, F. ADDEO AND S. COPPOLA. 2001. Aims: Seventy-eight strains of lactic acid bacteria belonging to five genera and showing six different phenotype combinations of Lac (lactose fermentation), Prt (proteolytic activity) and Cit (citrate degradation) characters were investigated for their main flavouring properties with the aim to detect variability among and within the groups. Methods and Results: High resolution gas chromatography,mass spectrometry analysis of neutral volatile compounds produced in whey showed that, considering both neo-formation compounds and substances quantified in the whey cultures at different concentrations in comparison to the extract from sterile whey, the groups of lactococci, enterococci, thermophilic streptococci and mesophilic lactobacilli produced a higher number of volatiles than thermophilic lactobacilli and leuconostocs. Applying principal component analysis (PCA) to the results, enterococci, mesophilic lactobacilli and thermophilic streptococci showed a broad diversity, while lactococci included rather similar strains as well as strains with special flavouring properties. Applying PCA to thermophilic streptococci and enterococci, to lactococci and enterococci, to lactococci and thermophilic streptococci, or to mesophilic and thermophilic lactobacilli, the strains gathered consistently with their systematic position. Conclusions: The study evidenced strains producing some volatile compounds responsible for food flavouring. Flavouring properties were variable among the systematic groups and in some cases different within the same bacterial group. Significance and Impact of the Study: The potential of the findings is discussed with reference to the development of flavouring adjuncts for the dairy industry. [source] Towards a more general species,area relationship: diversity on all islands, great and smallJOURNAL OF BIOGEOGRAPHY, Issue 4 2001Lomolino Aim To demonstrate a new and more general model of the species,area relationship that builds on traditional models, but includes the provision that richness may vary independently of island area on relatively small islands (the small island effect). Location We analysed species,area patterns for a broad diversity of insular biotas from aquatic and terrestrial archipelagoes. Methods We used breakpoint or piecewise regression methods by adding an additional term (the breakpoint transformation) to traditional species,area models. The resultant, more general, species,area model has three readily interpretable, biologically relevant parameters: (1) the upper limit of the small island effect (SIE), (2) an estimate of richness for relatively small islands and (3) the slope of the species,area relationship (in semi-log or log,log space) for relatively large islands. Results The SIE, albeit of varying magnitude depending on the biotas in question, appeared to be a relatively common feature of the data sets we studied. The upper limit of the SIE tended to be highest for species groups with relatively high resource requirements and low dispersal abilities, and for biotas of more isolated archipelagoes. Main conclusions The breakpoint species,area model can be used to test for the significance, and to explore patterns of variation in small island effects, and to estimate slopes of the species,area (semi-log or log,log) relationship after adjusting for SIE. Moreover, the breakpoint species,area model can be expanded to investigate three fundamentally different realms of the species,area relationship: (1) small islands where species richness varies independent of area, but with idiosyncratic differences among islands and with catastrophic events such as hurricanes, (2) islands beyond the upper limit of SIE where richness varies in a more deterministic and predictable manner with island area and associated, ecological factors and (3) islands large enough to provide the internal geographical isolation (large rivers, mountains and other barriers within islands) necessary for in situ speciation. [source] Eclecticism in health services for developmental disordersJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 3 2000M McDowell Abstract: The term ,eclectic', as applied to health care for children with developmental disorders, portrays an individualized, adaptive service response to local constraints and pressures. While this may appear appropriate for the local setting, the end result is a broad diversity of health care approaches. This paper discusses three separate processes that interact at a local level, increasing the likelihood of an eclectic local model of health care for this population of children. The first process draws from the direct clinical work. Variable training, knowledge and skills among health care providers, in combination with differing beliefs around the nature of the problems and their management leads to health care which directly reflects the attributes of the local clinicians. A separate, second process fuelling variability is the differing models of departmental responsibility across Australia , which Government departments fund which aspect of care for children with disabilities. The final process relates to funding streams for health care. State public health, federal Medicare and private insurance all support health services for children with disabilities, with the financial incentives (budgets compared to fee-for-service) driving a divergence of practice. This paper concludes that the external political, administrative and financial frameworks within which health care is constructed will continue to promote clinical eclecticism to a degree that would probably be considered unacceptable in other areas of child health care. The solution can only arise from within the clinical work itself, with greater clarity of understanding around the nature of the disorders, the outcomes for which health care takes responsibility, and an increasing focus on an evidence based set of approaches towards achieving these. [source] PHYLOGENY OF PHAGOTROPHIC EUGLENIDS (EUGLENOZOA): A MOLECULAR APPROACH BASED ON CULTURE MATERIAL AND ENVIRONMENTAL SAMPLES,JOURNAL OF PHYCOLOGY, Issue 4 2003Ingo Busse Molecular studies based on small subunit (SSU) rDNA sequences addressing euglenid phylogeny hitherto suffered from the lack of available data about phagotrophic species. To extend the taxon sampling, SSU rRNA genes from species of seven genera of phagotrophic euglenids were investigated. Sequence analyses revealed an increasing genetic diversity among euglenid SSU rDNA sequences compared with other well-known eukaryotic groups, reflecting an equally broad diversity of morphological characters among euglenid phagotrophs. Phylogenetic inference using standard parsimony and likelihood approaches as well as Bayesian inference and spectral analyses revealed no clear support for euglenid monophyly. Among phagotrophs, monophyly of Petalomonas cantuscygni and Notosolenus ostium, both comprising simple ingestion apparatuses, is strongly supported. A moderately supported clade comprises phototrophic euglenids and primary osmotrophic euglenids together with phagotrophs, exhibiting a primarily flexible pellicle composed of numerous helically arranged strips and a complex ingestion apparatus with two supporting rods and four curved vanes. Comparison of molecular and morphological data is used to demonstrate the difficulties to formulate a hypothesis about how the ingestion apparatus evolved in this group. [source] Life history determines biogeographical patterns of soil bacterial communities over multiple spatial scalesMOLECULAR ECOLOGY, Issue 19 2010A. BISSETT Abstract The extent to which the distribution of soil bacteria is controlled by local environment vs. spatial factors (e.g. dispersal, colonization limitation, evolutionary events) is poorly understood and widely debated. Our understanding of biogeographic controls in microbial communities is likely hampered by the enormous environmental variability encountered across spatial scales and the broad diversity of microbial life histories. Here, we constrained environmental factors (soil chemistry, climate, above-ground plant community) to investigate the specific influence of space, by fitting all other variables first, on bacterial communities in soils over distances from m to 102 km. We found strong evidence for a spatial component to bacterial community structure that varies with scale and organism life history (dispersal and survival ability). Geographic distance had no influence over community structure for organisms known to have survival stages, but the converse was true for organisms thought to be less hardy. Community function (substrate utilization) was also shown to be highly correlated with community structure, but not to abiotic factors, suggesting nonstochastic determinants of community structure are important Our results support the view that bacterial soil communities are constrained by both edaphic factors and geographic distance and further show that the relative importance of such constraints depends critically on the taxonomic resolution used to evaluate spatio-temporal patterns of microbial diversity, as well as life history of the groups being investigated, much as is the case for macro-organisms. [source] Resolving the source populations that contribute to the X-ray background: The 2 Ms Chandra Deep Field-North SurveyASTRONOMISCHE NACHRICHTEN, Issue 1-2 2003D. M. Alexander Abstract With , 2 Ms of exposure, the Chandra Deep Field-North (CDF-N) survey provides the deepest view of the Universe in the 0.5,8.0 keV band. Five hundred and three (503) X-ray sources are detected down to on-axis 0.5,2.0 keV and 2,8 keV flux limits of , 1.5 × 10,17 erg cm,2 s,1 and , 1.0 × 10,16 erg cm,2 s,1, respectively. These flux limits correspond to L0.5,8.0 keV, 3 × 1041 erg s,1 at z = 1 and L0.5,8.0 keV, 2 × 1043 erg s,1 at z = 6; thus this survey is sensitive enough to detect starburst galaxies out to moderate redshift and Seyfert galaxies out to high redshift. We present the X-ray observations, describe the broad diversity of X-ray selected sources, and review the prospects for deeper exposures. [source] Teaching of biochemistry in medical schoolBIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 6 2008A well-trodden pathway? Abstract Biochemistry and molecular biology occupy a unique place in the medical school curriculum. They are frequently studied prior to medical school and are fundamental to the teaching of biomedical sciences in undergraduate medical education. These two circumstances, and the trend toward increased integration among the disciplines, have led to reconsideration of biochemistry instruction in many medical schools. We conducted a survey to explore the evolving trends in biochemistry education. A broad diversity was evident in parameters including course content, faculty, governance, prerequisites, and teaching methods. Notably, sharp differences were apparent between freestanding biochemistry courses and those in which biochemistry is integrated with other subjects. Furthermore, the data imply a likely trend toward increased integration of biochemistry with other disciplines in the medical school curriculum. [source] RISK DETECTION IN INDIVIDUAL HEALTH CARE: ANY LIMITS?BIOETHICS, Issue 8 2010GER PALMBOOM ABSTRACT Background: Biomedical science is producing an avalanche of data about risk factors, often with a small predictive value, associated with a broad diversity of diseases. Prevention and screening are increasingly moving from public health into the clinic. Therefore, the question of which risk factors to investigate and disclose in the individual patient, becomes ethically increasingly urgent. In line with Wilson and Jungner's public health-related 10 principles for screening, it seems crucial to distinguish important from unimportant health risks. Aim: to explore the ways in which clinicians distinguish important from unimportant health risks. Methods: We interviewed 36 respondents (gastroenterologists and gynaecologists/obstetrics) in 5 focus group interviews and 15 open in-depth interviews on their interpretation of what makes a health risk important. Results: Physicians primarily interpreted importance as the severity of the possible harm, less often its probability. Possibilities of prevention or reassurance strongly influenced their judgment on importance. Discussion: It is not likely that interpreting ,important' as ,severe' will help in differentiating meaningful from meaningless risk knowledge. A more fundamental change in our ways of dealing with risk may be called for. We discuss existing literature on resilience as an alternative way to deal with risk. Balancing prevention and risk reduction with resilience could be a fruitful direction. [source] A unifying explanation for diverse metabolic scaling in animals and plantsBIOLOGICAL REVIEWS, Issue 1 2010Douglas S. Glazier The scaling of metabolic rate with body mass has long been a controversial topic. Some workers have claimed that the slope of log-log metabolic scaling relationships typically obeys a universal 3/4-power law resulting from the geometry of resource-transport networks. Others have attempted to explain the broad diversity of metabolic scaling relationships. Although several potentially useful models have been proposed, at present none successfully predicts the entire range of scaling relationships seen among both physiological states and taxonomic groups of animals and plants. Here I argue that our understanding may be aided by three shifts in focus: from explaining average tendencies to explaining variation between extreme boundary limits, from explaining the slope and elevation (metabolic level) of scaling relationships separately to showing how and why they are interrelated, and from focusing primarily on internal factors (e.g. body design) to a more balanced consideration of both internal and external (ecological) factors. By incorporating all of these shifts in focus, the recently proposed metabolic-level boundaries hypothesis appears to provide a useful way of explaining both taxonomic and physiological variation in metabolic scaling relationships. This hypothesis correctly predicts that the scaling slope should vary mostly between 2/3 and 1 and that it should be related to metabolic (activity) level according to an approximately U-shaped function. It also implies that the scaling of other energy-dependent biological processes should be related to the metabolic level of the organisms being examined. Some data are presented that support this implication, but further research is needed. [source] Complex Biohopanoids Synthesis: Efficient Anchoring of Ribosyl Subunits onto a C30,HopaneCHEMISTRY - A EUROPEAN JOURNAL, Issue 5 2007Weidong Pan Dr. Abstract Bacteriohopanoids represent a particularly important series of triterpenoids, widely distributed in bacteria. One of the common features of these pentacyclic hopanepolyols is the presence of an extended non-terpenoid and polyhydroxylated side chain attached to the triterpenic moiety through a CC bond. The biological function of biohopanoids also has to be addressed when one considers the broad diversity in both structures and functionalities found in the side chain. Moreover, the stereochemistries of some biohopanoids are still unconfirmed, due to the lack of synthetic methods to prepare them. In this study we describe an efficient methodology for the formation of the CC bond between the C30 -hopane component and C5 -polyhydroxylated carbohydrates through the use of a hopanyllithium intermediate, which has enabled us to synthesize several biohopanoid derivatives. We also report the first synthesis of hopanepentol bearing an additional hydroxy group at position C31. [source] Molecular epidemiology of the nasal colonization by methicillin-susceptible Staphylococcus aureus in Swiss childrenCLINICAL MICROBIOLOGY AND INFECTION, Issue 9 2010C. Mégevand Clin Microbiol Infect 2010; 16: 1414,1420 Abstract Nasal carriage of Staphylococcus aureus contributes to an increased risk of developing an infection with the same bacterial strain. Genetic regulatory elements and toxin-expressing genes are virulence factors associated with the pathogenic potential of S. aureus. We undertook an extensive molecular characterization of methicillin-susceptible S. aureus (MSSA) carried by children. MSSA were recovered from the nostrils of children. The presence of Panton-Valentine leukocidin (PVL), exfoliatins A and B (exfoA and exfoB), and the toxic-shock staphylococcal toxin (TSST-1) and agr group typing were determined by quantitative PCR. A multiple-locus variable-number of tandem repeat analysis (MLVA) assay was also performed for genotyping. Five hundred and seventy-two strains of MSSA were analysed. Overall, 30% were positive for toxin-expressing genes: 29% contained one toxin and 1.6% two toxins. The most commonly detected toxin gene was tst, which was present in 145 (25%) strains. The TSST-1 gene was significantly associated with the agr group 3 (OR 56.8, 95% CI 32.0,100.8). MLVA analysis revealed a large diversity of genetic content and no clonal relationship was demonstrated among the analysed MSSA strains. Multilocus sequence typing confirmed this observation of diversity and identified ST45 as a frequent colonizer. This broad diversity in MSSA carriage strains suggests a limited selection pressure in our geographical area. [source] | |||||||||||||||||||