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Selected Species (selected + species)
Selected AbstractsMicrobial Aetiology Of Endodontic Treatment Failure And Pathogenic Properties Of Selected SpeciesAUSTRALIAN ENDODONTIC JOURNAL, Issue 1 2004Dip Endo, Dr David Figdor MDSc (Melb), FRACDS First page of article [source] How does the knowledge about the spatial distribution of Iberian dung beetle species accumulate over time?DIVERSITY AND DISTRIBUTIONS, Issue 6 2007Jorge M. Lobo ABSTRACT Different distribution maps can be obtained for the same species if localities where species are present are mapped at different times. We analysed the accumulation of information over time for a group of dung beetle species in the Iberian Peninsula. To do this, we used all available information about the distribution of the group as well as data on selected species to examine if the process of discovery of species distribution has occurred in a climatically or spatially structured fashion. Our results show the existence of a well-defined pattern of temporal growth in distributional information; due to this, the date of capture of each specimen can be explained by the environmental and spatial variables associated to the collection sites. We hypothesize that such temporal biases could be the rule rather than the exception in most distributional data. These biases could affect the weighting of environmental factors that influence species distributions, as well as the accuracy of predictive distribution models. Systematic surveys should be a priority for the description of species geographical ranges in order to make robust predictions about the consequences of habitat and climate change for their persistence and conservation. [source] Assessing macroinvertebrate metrics for classifying acidified rivers across northern EuropeFRESHWATER BIOLOGY, Issue 7 2010S. JANNICKE MOE Summary 1. The effects of acidification on ecological status of rivers in Northern Europe must be assessed according to the EU Water Framework Directive (WFD). Several acidification metrics based on macroinvertebrates already exist in different countries, and the WFD requires that they be comparable across northern Europe. Thus, we compiled macroinvertebrate monitoring data from the U.K. (n = 191 samples), Norway (n = 740) and Sweden (n = 531) for analysis against pH. 2. We tested new and existing acidification metrics developed nationally and used within the Northern Geographical Intercalibration Group. The new metrics were based on the acidification sensitivity of selected species and are proposed as a first step towards a new common indicator for acidification for Northern Europe. 3. Metrics were assessed according to responsiveness to mean pH, degree of nonlinearity in response and consistency in responses across countries. We used flexible, nonparametric regression models to explore various properties of the pressure,response relationships. Metrics were also analysed with humic content (total organic carbon above/below 5 mg L,1) as a covariate. 4. Most metrics responded clearly to pH, with the following metrics explaining most of the variance: Acid Water Indicator Community, Number of ephemeropteran families, Medin's index, Multimetric Indicator of Stream Acidification and the new metric ,Proportion of sensitive Ephemeroptera'. 5. Most metrics were significantly higher in humic than in clear-water rivers, suggesting smaller acidification effects in humic rivers. This result supports the proposed use of humic level as a typological factor in the assessment of acidification. 6. Some potentially important effects could not be considered in this study, such as the additional effects of metals, episodic acidification and the contrasting effects of natural versus anthropogenic acidity. We advocate further data collection and testing of metrics to incorporate these factors. [source] Raptor and owl bone from Niah Caves, Sarawak: identifications and morphological variation in the humerus and tarsometatarsus of selected raptorsINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 4 2009C. M. Stimpson Abstract This paper reports on the findings of a preliminary investigation of raptor (Accipitriformes) and owl (Strigiformes) bones recovered during the original archaeological investigations of the Niah Caves during the 1950s and 1960s. Observations of morphological characteristics that were utilised to distinguish humeri and tarsometatarsi of selected species are included. A total of 48 archaeological specimens were identified, representing five genera of Accipitridae (Order Accipitriformes) and two genera of Strigidae (Order Strigiformes). Forty-four specimens were further identified to species (Accipitriformes, four species; Strigiformes, three species) including a Late Pleistocene record of the bathawk (Machieramphus alcinus) dated to 36,470,±,250 (uncal.) bp. Modern representatives of all identified species have been recorded recently in Sarawak. The relevance of raptors and owls in the palaeoecological reconstruction of this site is discussed, and the potential role of these birds as taphonomic agents is considered. Copyright © 2009 John Wiley & Sons, Ltd. [source] Local extent of old-growth woodland modifies epiphyte response to climate changeJOURNAL OF BIOGEOGRAPHY, Issue 2 2009Christopher J. Ellis Abstract Aim, To quantify the interaction between climate and woodland continuity in determining the bioclimatic response of lichen epiphytes. Location, Northern Britain (Scotland). Methods, Indicator-species analysis was used to pre-select lichen epiphytes along parallel gradients in climate and the extent of old-growth woodland. Nonparametric multiplicative regression was used to describe in a predictive model the individualistic response of selected species, which were projected based on climate-change scenarios and contrasting patterns of simulated woodland loss or gain. Species with a similar response were grouped using a novel application of cluster analysis to summarize the potentially huge number of projected outcomes. Projected patterns of occurrence under climate-change scenarios were examined for different levels of old-growth woodland extent. Results, Forty-two lichen species were statistically significant indicator species in oceanic woodlands, and old-growth indicators under suboptimal climatic conditions. Responses to climate-change scenarios were contrasting, with one group comprising species projected to increase in extent in response to climate warming, and other response groups projected to decrease in occurrence, possibly in response to shifting rainfall patterns. The occurrence of all response groups had a positive relationship with old-growth woodland extent. Main conclusions, An ,oceanic' biogeographical group of epiphytes identified using the baseline climatic and present-day woodland setting comprised species with a cyanobacterial photobiont or tropical phytogeographical affinities. However, within this group the individual species responses to climate-change scenarios were contrasting. Additionally, group responses may be poorly matched with simple ecological traits. However, the studied interaction between climate and habitat continuity suggests that the impact of climate change might be offset for certain lichen epiphytes by appropriate management of woodland resources, for example, expansion of native woodland around remnant old-growth stands. [source] Post-Hypsithermal plant disjunctions in western Alberta, CanadaJOURNAL OF BIOGEOGRAPHY, Issue 3 2003W. L Strong Abstract Aim, Evaluate the hypothesis that nine disjunct vascular plant species along the eastern slopes of the Rocky Mountains and in the Peace River District of west-central Alberta represent remnants of more southerly vegetation that occupied these areas during the Holocene Hypsithermal (9000,6000 yr bp). Alternatively, these plants represent populations that became established because of independent chance dispersal events. Location, This study focuses on the area east of the Rocky Mountain Continental Divide in the Province of Alberta and the State of Montana in western Canada and USA, respectively. Methods, Disjunct species were identified and their distributions mapped based on a review of occurrence maps and records, botanical floras and checklists, herbaria specimens, ecological and botanical studies, and field surveys of selected species. A disjunct species was defined as a plant population separated from its next nearest occurrence by a distance of > 300 km. Evaluation of the hypothesis was based on a review of published and unpublished pollen stratigraphy and palaeoecological studies. The potential geographical distribution of Hypsithermal vegetation was based on modern regional-based ecosystem mapping and associated monthly temperature summaries as well as future climatic warming models. Results, The hypothesis was compatible with Holocene pollen stratigraphy, Hypsithermal permafrost and fen occurrence, and palaeosol phytolith analyses; and future global climatic warming models. Modelled regional Hypsithermal vegetation based on a 1 °C increase in July temperatures relative to current conditions, indicated that much of the boreal forest zone in Alberta could have been grassland, which would explain the occurrence of Prairie species in the Peace River District. This amount of latitudinal vegetation shift (6.5°) was similar to an earlier Hypsithermal permafrost zone location study. An equivalent shift in vegetation along the eastern Cordillera would have placed south-western Montana-like vegetation and species such as Boykinia heucheriformis (Rydb.) Rosend. and Saxifraga odontoloma Piper within the northern half of the Rocky Mountains and foothills in Alberta, which represents the location of modern-day disjunct populations of these species. Main conclusions, Warmer and drier climatic conditions during the Holocene Hypsithermal resulted in the northward displacement of vegetation zones relative to their current distribution patterns. Most of Alberta was probably dominated by grasslands during this period, except the Rocky Mountains and northern highlands. Modern-day species disjunctions within the Rocky Mountains and Peace River District as well as more northerly areas such as the Yukon Territory occurred when the vegetation receded southward in response to climatic cooling after the Hypsithermal. Wind dispersal was considered an unlikely possibility to explain the occurrence of the disjunct species, as most of the plants lack morphological adaptations for long distance transport and the prevailing winds were from west to east rather than south to north. However, consumption and transport of seeds by northward migrating birds could not be excluded as a possibility. [source] Laser desorption postionization for imaging MS of biological materialJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 2 2010Artem Akhmetov Abstract Vacuum ultraviolet single photon ionization (VUV SPI) is a soft ionization technique that has the potential to address many of the limitations of matrix-assisted laser desorption/ionization (MALDI) for imaging MS. Laser desorption postionization (LDPI) uses VUV SPI for postionization and is experimentally analogous to a MALDI instrument with the addition of a pulsed VUV light source. This review discusses progress in LDPI-MS over the last decade, with an emphasis on imaging MS of bacterial biofilms, analytes whose high salt environment make them particularly resistant to imaging by MALDI-MS. This review first considers fundamental aspects of VUV SPI including ionization mechanisms, cross sections, quantum yields of ionization, dissociation and potential mass limits. The most common sources of pulsed VUV radiation are then described along with a newly constructed LDPI-MS instrument with imaging capabilities. Next, the detection and imaging of small molecules within intact biofilms is demonstrated by LDPI-MS using 7.87 eV (157.6 nm) VUV photons from a molecular fluorine excimer laser, followed by the use of aromatic tags for detection of selected species within the biofilm. The final section considers the future prospects for imaging intact biological samples by LDPI-MS. Copyright © 2010 John Wiley & Sons, Ltd. [source] Medicinal plant species with potential antidiabetic propertiesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2007Srinivasa Rao Mentreddy Abstract Diabetes mellitus is one of the world's major diseases. It currently affects an estimated 143 million people worldwide and the number is growing rapidly. In the USA alone, about 20.8 million or 7% of the population suffer from diabetes or related complications. The estimated direct and indirect costs of diabetes exceed US$ 132 billion annually. Plant-based medicinal products have been known since ancient times, and several medicinal plants and their products (active natural principles and crude extracts) have been used to control diabetes in the traditional medicinal systems of many cultures worldwide, including those of the Asian Indians, Chinese and South Americans. A limited number of these plant species have been studied and validated for their hypoglycaemic properties using diabetic animal models and in clinical studies using human subjects. Several oral hypoglycaemic agents are the primary forms of treatment for diabetes. However, prominent side-effects of such drugs are the main reason for an increasing number of people seeking alternative therapies that may have less severe or no side-effects. Thus plant-based herbal drugs or botanicals are emerging as the primary components of holistic approaches to diabetes management. In this review, selected species that have been validated for their hypoglycaemic or antihyperglycaemic properties using laboratory diabetic animal models and in clinical trials using human subjects, and reported in refereed journals are presented. Copyright © 2007 Society of Chemical Industry [source] Patagial morphology of Draco volans (Reptilia: Agamidae) and the origin of glissant locomotion in flying dragonsJOURNAL OF ZOOLOGY, Issue 4 2001Anthony P. Russell Abstract The integrative patagial morphology of Draco volans was examined to elucidate the possible evolutionary pathway of origin of active patagia in the flying dragons and in extinct taxa that are thought to have possessed similarly constructed flight membranes. The area of the patagia and accessory aerodynamic surfaces is compared between Draco volans and Ptychozoon kuhli, a gekkonid with passive patagia. Comparisons of patagial area are also made between selected species of Draco. Scale architecture of the patagium of Draco is described and is related to pertinent aspects of the structure and properties of the integument. The relationships of these characteristics to the morphology of the ribs and their related musculature are emphasized. The overall assessment of these features in relation to patagial form is employed to develop an evolutionary scenario for the origin of active patagia. [source] Similarity between the soil seed bank and the standing vegetation in the Strandveld Succulent Karoo, South AfricaLAND DEGRADATION AND DEVELOPMENT, Issue 6 2003A. J. de Villiers Abstract The similarity in species composition and abundance between the soil seed bank and its associated vegetation was studied in six vegetation units of the Strandveld Succulent Karoo, South Africa. A total of 103 taxa were recorded in the vegetation, of which 34 taxa were also present in the seed bank. Five taxa were unique to the soil seed bank. In general, the taxa most abundant in the vegetation were also recorded in the seed bank and vice versa. Mean seed bank density varied between different plant types. Perennial taxa were most abundant in the vegetation, while annual taxa were most abundant in the seed bank. Annual taxa (excluding grasses) yielded the highest similarity between vegetation and seed bank (67,9 per cent), while that of perennial (excluding grasses) and grass taxa were 34,2 per cent and 40,0 per cent respectively. An overall similarity of 47,0 per cent between the seed bank and its associated vegetation was obtained for this part of the Strandveld Succulent Karoo. The seed bank of the study site will be a good source of future annual vegetation, but not of perennial vegetation. Topsoil replacement, sowing and transplanting of selected species will be essential for the success of post-mining revegetation efforts following complete destruction of the existing vegetation. Annual species may be recruited from the soil stored seed bank, while many perennial species will have to be reintroduced by means of sowing and/or transplanting. Copyright © 2003 John Wiley & Sons, Ltd. [source] DNA barcodes to identify species and explore diversity in the Adelgidae (Insecta: Hemiptera: Aphidoidea)MOLECULAR ECOLOGY RESOURCES, Issue 2009R. G. FOOTTIT Abstract The Adelgidae are relatively small, cryptic insects, exhibiting complex life cycles with parthenogenetic reproduction. Due to these characteristics, the taxonomy of the group is problematic. Here, we test the effectiveness of the standard 658-bp barcode fragment from the 5,-end of the mitochondrial cytochrome c oxidase 1 gene (COI) in differentiating among 17 species of Adelgidae, in associating life-cycle stages, and in assessing patterns of geographical variation in selected species. Species of Adelgidae are well-differentiated by DNA barcodes, enabling the identification of different morphological forms, immature stages and individuals on different hosts and at different periods of the life cycle. DNA barcodes have uncovered cryptic diversity within taxa and, in other cases, a lack of sequence divergence in species pairs previously separated by life-cycle characteristics, indicating a need for further taxonomic analysis. [source] Antiproliferative activity of Hungarian Asteraceae species against human cancer cell lines.PHYTOTHERAPY RESEARCH, Issue 12 2007Part I Abstract Aqueous and organic extracts of 25 selected species from four tribes of Hungarian Asteraceae were screened in vitro for antiproliferative activity against HeLa (cervix epithelial adenocarcinoma), A431 (skin epidermoid carcinoma) and MCF7 (breast epithelial adenocarcinoma) cells, using the MTT assay. Twenty five of the 228 tested extracts from different parts of the species of Astereae (6), Inuleae (3), Heliantheae (5) and Anthemideae (11) demonstrated a substantial antiproliferative effect (at least 50% inhibition of cell proliferation) at 10 µg/mL against one or more of the cell lines. Complete dose-response curves were generated and IC50 values were calculated for these active extracts, and their direct cytotoxic effects were determined. In summary, 11 of the tested 25 plants were found to be active and 4 of them (Anthemis ruthenica, Erigeron canadensis, Erigeron annuus and Inula ensifolia) had not been studied previously for either active compounds or anticancer properties. Copyright © 2007 John Wiley & Sons, Ltd. [source] The development of bird indicators for British fresh waters and wetlandsAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2010Mark Everard Abstract 1.Population trends of breeding birds in freshwater habitats generated from long-term monitoring in the UK provide biodiversity indicators for some wetland habitats. 2.Bird species were assigned to target wetland habitats based on evidence of their association and data availability. Species trends for each habitat were then modelled using a range of survey data from BTO schemes including the Common Bird Census, Breeding Bird Survey, Waterways Bird Survey and Waterways Breeding Bird Survey. 3.Smoothed population trends for the selected species were combined to produce a composite indicator for birds of selected waterways and wetland habitats for England. This forms one of the three strands of a new aggregate bird indicator in the UK. 4.These indicators show generally that breeding bird species associated with slow-moving waterways and standing waters have increased over the past 30 years. Over the same period, species associated with fast-flowing waters show modest declines, species associated with reed habitats have declined and recovered, while species associated with wet grasslands, including marshes, have declined. 5.Further monitoring and exploration of the relationship between these indicators is needed to improve confidence in species trends and identifying potential drivers of change in freshwater and wetland habitats. Copyright © 2009 John Wiley & Sons, Ltd. [source] Luminescent Excited-State Intramolecular Proton-Transfer (ESIPT) Dyes Based on 4-Alkyne-Functionalized [2,2,-Bipyridine]-3,3,-diol DyesCHEMISTRY - A EUROPEAN JOURNAL, Issue 14 2008Gilles Ulrich Dr. Abstract Functionalized 6,6,-dimethyl-3,3,-dihydroxy-2,2,-bipyridine dyes (BP(OH)2) exhibit relatively intense fluorescence from the relaxed excited state formed by excited-state intramolecular proton transfer (ESIPT). Bromo functionalization of (BP(OH)2) species followed by palladium(0)-catalyzed reactions allows the connection (via alkyne tethers) of functional groups, such as the singlet-emitter diazaboraindacene (bodipy) group or a chelating module (terpyridine; terpy). The X-ray structure of the terpy-based compound confirms the planarity of the 3,3,-dihydroxy-bipyridine unit. The new dyes exhibit relatively intense emission on the nanosecond timescale when in fluid solution, in the solid state at 298,K, and in rigid glasses at 77,K. In some cases, the excitation wavelength luminescence was observed and attributed to 1),inefficiency of the ESIPT process in particular compounds when not enough vibrational energy is introduced in the Franck,Condon state, which is populated by direct light excitation or 2),the presence of an additional excited state that deactivates to the ground state without undergoing the ESIPT process. For some selected species, the effect of the addition of zinc salts on the absorption and luminescence spectra was investigated. In particular, significant fluorescence changes were observed as a consequence of probable consecutive formation of a 1:1 and 1:2 molecular ratio of ligand/zinc adducts owing to coordination of ZnII ions by the bipyridyldiol moieties, except when an additional terpyridine subunit is present. In fact, this latter species preferentially coordinates to the ZnII ion in a 1:1 molecular ratio and further inhibits ZnII interaction. In the hybrid Bodipy/BP(OH)2 species, complete energy transfer from the BP(OH)2 to the bodipy fluorophore occurs, leading to exclusive emission from the lowest-lying bodipy subunit. Des composés colorés à base de 6,6,-dimethyl-3,3,-dihydroxy-2,2,-bipyridine (BP(OH)2) ont été synthétisés et présentent une fluorescence relativement intense issue de la relaxation d,un état excité provenant d,un transfert de proton dans l,état excité (ESIPT). La bromation de dérivés (BP(OH)2) suivie d,un couplage croisé catalysé par du Pd0sous-ligandé permet de connecter (par l,intermédiaire de pont alcyne) des groupes fonctionnels comme un groupe émetteur singulet de type boradiazaindacène (Bodipy) ou un module chélatant universel (une terpyridine). Une structure par diffraction aux rayons X a été obtenu avec le dérivé terpyridine, celle ci confirme la planéité de l,unité 3,3,-dihydroxy-bipyridine. Les nouveaux fluorophores possèdent une émission relativement intense avec une durée de vie de l,ordre de la nanoseconde, en solution et à l,état solide à 298,K ainsi que dans un verre à 77,K. Dans certain cas, la luminescence dépend de la longueur d,onde d,excitation, ce phénomène est attribué à (i) l,inefficacité du processus ESIPT, quand trop peu d,énergie vibrationnelle est introduite dans l,état Franck-Condon peuplé directement par la lumière d,excitation (ii) la présence d,un état excité supplémentaire qui désactive l,état fondamental sans passer par un processus ESIPT. Pour certains composés, l,effet de l,addition de sels de Zinc sur les spectres d,absorption et d,émission a été étudié : en particulier, des changements significatifs de fluorescence ont été observés, probablement due à la formation consécutive de complexes ligand/zinc de st,chiométrie 1:1 et 1:2, provenant de la coordination des cations ZnIIpar l,unité bipyridyl-diol, sauf quand une fonction terpyridine est présente. En fait, dans cette dernière espèce le zinc est préférentiellement coordiné par la terpyridine dans un ratio 1:1, et toute coordination supplémentaire de Zinc semble inhibée. Dans le composé hybride Bodipy/BP(OH)2,un transfert d,énergie quantitatif est observé du BP(OH)2vers le fluorophore Bodipy, entraînant une émission exclusive de la sous-unité Bodipy. Composti basati sulla subunità 6,6,-dimetil-3,3,-dididrossi-2,2,-bipiridina (BP(OH)2), variamente funzionalizzati, presentano fluorescenza relativamente intensa da stati eccitati formati attraverso trasferimento protonico nello stato eccitato (ESIPT). Bromo-funzionalizzazione dei composti di tipo BP(OH)2, seguita da reazioni catalizzate da Pd(0), permettono di connettere (con legame alchinico) gruppi funzionali quali il diazaboroindacene (Bodipy) o un modulo chelante (terpiridina) al frammento BP(OH)2. La struttura ai raggi X del composto contenente la terpiridina conferma la planarità dell,unità 3,3,-diidrossi-bipiridina. Le nuove specie presentano intensa emissione nella scala dei nanosecondi, in soluzione fluida ed allo stato solido a 298,K ed in matrice rigida a 77,K. In alcuni casi, la luminescenza dipende dalla lunghezza d,onda di eccitazione: questo fenomeno è attribuito a (i) inefficienza del processo ESIPT, quando non sufficiente energia vibrazionale è introdotta nello stato Franck-Condon a seguito di eccitazione luminosa o (ii) alla presenza di uno stato eccitato addizionale che si disattiva allo stato fondamentale senza passare dallo stato eccitato prodotto attraverso il meccanismo ESIPT. Per composti selezionati è stato anche studiato l,effetto della presenza di sali di zinco sulle proprietà di assorbimento elettronico e di luminescenza: significativi cambiamenti della fluorescenza sono stati osservati, come conseguenza della consecutiva formazione di addotti 1:1 e 1:2 (rapporto molare BP(OH)2/zinco), dovuta alla coordinazione di cationi di ZnIIda parte del bipiridil-diolo, che si verifica in tutti i casi studiati tranne in presenza di una subunità terpiridinica. In quest,ultimo caso, infatti, si forma soltanto l,addotto 1:1, e ulteriore coordinazione di cationi di ZnIIappare inibita. Nella specie ibrida Bodipy/BP(OH)2si verifica un completo trasferimento di energia elettronica dal BP(OH)2 al Bodipy, che porta ad emissione esclusivamente dalla subunità Bodipy, a piû bassa energia. [source] | |||||||||||||||||||