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Local Sources (local + source)
Selected AbstractsCombining visual and geochemical analyses to source chert on Southern Baffin Island, Arctic CanadaGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 4 2009S. Brooke Milne A combined methodological approach using visual and geochemical methods is introduced and preliminary results of a study illustrating its effectiveness to determine chert source provenance are presented. This study focuses on lithic debitage and raw chert samples collected from the interior of southern Baffin Island, Arctic Canada. Chert is abundant throughout this region yet it occurs as small, scattered surface nodules that are highly variable in color. Prior to this study, little was known about the provenance of this local toolstone and whether it derived from local outcrops, glacial till sheets, or both. Given the pronounced variability exhibited by this chert, we use individual attribute analysis and petrography to impose some kind of analytical order upon an otherwise random aggregation of rocks. Thereafter, inductively coupled plasma mass spectrometry and secondary ion mass spectrometry are used to test the validity of these color categories to determine from how many geochemically distinct sources they derive. Using a standard that measures Al to a ratio of Ga/Zr, our results indicate that all of the raw chert samples derive from a single local source, while the debitage derives from four different sources, including the one that is local. We are confident that this combined methodological approach can be applied in other regions where chert variability is pronounced and source provenance is unknown. © 2009 Wiley Periodicals, Inc. [source] A reconstruction of the history of a Holocene sand dune on Great Barrier Island, northern New Zealand, using pollen and phytolith analysesJOURNAL OF BIOGEOGRAPHY, Issue 6 2000M. Horrocks Abstract Aim, To reconstruct the history of a Holocene sand dune using pollen and phytolith analyses, and to identify the strengths, weaknesses and compatibility of these two methods in the interpretation of Quaternary coastal environments. Location, Great Barrier Island, northern New Zealand. Methods, Pollen and phytolith analyses were carried out on a sequence through a Holocene sand dune containing a palaeosol. Results, Phytoliths were present throughout the sequence. Grass phytoliths increased at the expense of tree phytoliths following fire disturbance. Pollen (and spores) was preserved only in the palaeosol part of the profile. Pteridium fern spores increased at the expense of tall tree pollen following the fire disturbance. Main conclusions, Lack of phytolith production by many species and problems of taxonomic specificity in many others restricts the usefulness of phytolith analysis to defining only broad vegetation types. In New Zealand, gymnosperms are invisible in the phytolith record and ferns are extremely under-represented. In contrast, pollen analysis usually provides a great deal of information regarding the composition of a particular vegetation type. The loss of microscopic charcoal fragments during the phytolith extraction process is a disadvantage in the reconstruction of environments where fires have occurred. The greater durability of phytoliths compared with pollen means that phytoliths may be found in sediments where pollen has not been preserved. The phytolith record may also provide evidence of wetter environments that are not apparent in the pollen record. Unlike grass pollen, which is widely dispersed and therefore blurs the spatial record, the presence of grass phytoliths in sediments indicates a local source. The simultaneous application of both methods potentially provides a powerful tool in ecological interpretation and the reconstruction of Quaternary coastal environments. [source] Dopaminergic neurons intrinsic to the striatumJOURNAL OF NEUROCHEMISTRY, Issue 6 2007Philippe Huot Abstract The striatum , the largest integrative component of the basal ganglia , harbors a population of neurons that express the enzyme tyrosine hydroxylase (TH), a faithful marker of dopaminergic neurons. The dopaminergic nature of these neurons is further supported by the fact that they express the dopamine (DA) transporter (DAT) and the nuclear orphan receptor Nurr1, a transcription factor essential for the expression of the DA phenotype by midbrain neurons. The vast majority of these neurons are morphologically similar to the medium-sized aspiny striatal interneurons and they all express the enzyme GAD65. The striatal TH-positive neurons increase markedly in number in animal models of Parkinson's disease (PD), where striatal DA concentrations are low, but this increase is abolished by L-dopa treatment. Hence, local DA concentrations appear to regulate the numerical density of this ectopic neuronal population, a phenomenon that is more likely the result of a shift in the phenotype of preexistent striatal interneurons rather than the recruitment of newborn neurons that will develop a DA phenotype. Altogether, these findings suggest that striatal TH-positive neurons act as a local source of DA and, as such, are part of a compensatory mechanism that could be artificially enhanced to alleviate or delay PD symptoms. [source] Genotoxicity and physicochemical characteristics of traffic-related ambient particulate matterENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2005Theo M. de Kok Abstract Exposure to ambient particulate matter (PM) has been linked to several adverse health effects. Since vehicular traffic is a PM source of growing importance, we sampled total suspended particulate (TSP), PM10, and PM2.5 at six urban locations with pronounced differences in traffic intensity. The mutagenicity, DNA-adduct formation, and induction of oxidative DNA damage by the samples were studied as genotoxicological parameters, in relation to polycyclic aromatic hydrocarbon (PAH) levels, elemental composition, and radical-generating capacity (RGC) as chemical characteristics. We found pronounced differences in the genotoxicity and chemical characteristics of PM from the various locations, although we could not establish a correlation between traffic intensity and any of these characteristics for any of the PM size fractions. Therefore, the differences between locations may be due to local sources of PM, other than traffic. The concentration of total (carcinogenic) PAHs correlated positively with RGC, direct and S9-mediated mutagenicity, as well as the induction of DNA adducts and oxidative DNA damage. The interaction between total PAHs and transition metals correlated positively with DNA-adduct formation, particularly from the PM2.5 fraction. RGC was not associated with one specific PM size fraction, but mutagenicity and DNA reactivity after metabolic activation were relatively high in PM10 and PM2.5, when compared with TSP. We conclude that the toxicological characteristics of urban PM samples show pronounced differences, even when PM concentrations at the sample sites are comparable. This implies that emission reduction strategies that take chemical and toxicological characteristics of PM into account may be useful for reducing the health risks associated with PM exposure. Environ. Mol. Mutagen., 2005. © 2005 Wiley-Liss, Inc. [source] Seed supply for broadscale restoration: maximizing evolutionary potentialEVOLUTIONARY APPLICATIONS (ELECTRONIC), Issue 4 2008Linda M. Broadhurst Abstract Restoring degraded land to combat environmental degradation requires the collection of vast quantities of germplasm (seed). Sourcing this material raises questions related to provenance selection, seed quality and harvest sustainability. Restoration guidelines strongly recommend using local sources to maximize local adaptation and prevent outbreeding depression, but in highly modified landscapes this restricts collection to small remnants where limited, poor quality seed is available, and where harvesting impacts may be high. We review three principles guiding the sourcing of restoration germplasm: (i) the appropriateness of using ,local' seed, (ii) sample sizes and population characteristics required to capture sufficient genetic diversity to establish self-sustaining populations and (iii) the impact of over-harvesting source populations. We review these topics by examining current collection guidelines and the evidence supporting these, then we consider if the guidelines can be improved and the consequences of not doing so. We find that the emphasis on local seed sourcing will, in many cases, lead to poor restoration outcomes, particularly at broad geographic scales. We suggest that seed sourcing should concentrate less on local collection and more on capturing high quality and genetically diverse seed to maximize the adaptive potential of restoration efforts to current and future environmental change. [source] Variability in the origin of carbon substrates for bacterial communities in mangrove sedimentsFEMS MICROBIOLOGY ECOLOGY, Issue 2 2004Steven Bouillon Abstract Organic carbon in mangrove sediments originates from both local sources (mangroves, microphytobenthos) and tidal inputs (e.g. phytoplankton, seagrass-derived material). The relative inputs of these sources may vary strongly, both within and between different mangrove sites. We combined elemental (TOC/TN) and bulk ,13C analysis on sediment cores from various mangrove sites with ,13C data of bacteria-specific phospholipid fatty acids (PLFA) in order to identify the dominant carbon substrates used by in situ bacterial communities. ,13C values of each of these markers showed a range of 10% or more across the different sites and sampling depths, but generally followed the ,13C trend observed in bulk organic carbon. Several sediment cores show a strong vertical gradient in PLFA ,13C, suggesting a selectivity for algal-derived carbon in the surface layers. Our data demonstrate that the origin of bacterial carbon substrates varies widely across different mangrove sites, and imply that data on mineralization of organic matter cannot be directly incorporated in ecosystem carbon budgets without an estimation of the contribution of various sources. [source] First stars contribution to the near-infrared background fluctuationsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2003M. Magliocchetti ABSTRACT We show that the emission from the first, metal-free stars inside Population III objects (Pop IIIs) is needed to explain the level of fluctuations in the near-infrared background (NIRB) recently discovered by Kashlinsky et al., at least at the shortest wavelengths. Clustering of (unresolved) Pop IIIs can in fact account for the entire signal at almost all the ,1,30 arcsec scales probed by observations in the J band. Their contribution fades away at shorter frequencies and becomes negligible in the K band. ,Normal', highly clustered, ,z,, 3 galaxies undergoing intense star formation such as those found in the Hubble Deep Fields can ,fill in' this gap and provide for the missing signal. It is in fact found that their contribution to the intensity fluctuations is the dominant one at ,= 2.17 ,m, while it gradually loses importance in the H andJ bands. The joint contribution from these two populations of cosmic objects is able, within the errors, to reproduce the observed power spectrum in the whole near-infrared range on small angular scales (,, 200 arcsec for Pop III protogalaxies). Signals on larger scales detected by other experiments instead require the presence of more local sources. [source] Occurrence and distribution of Raspberry bushy dwarf virus in commercial Rubus plantations in England and WalesPLANT PATHOLOGY, Issue 6 2001D. J. Barbara Serological surveys for Raspberry bushy dwarf virus (RBDV) made between 1995 and 1997 and covering ,,10% of the commercial farms growing Rubus (red raspberry and hybrid berries) in England and Wales showed that this virus was present on approximately one-quarter of all farms and in approximately one-sixth of all plots tested. RBDV was found in all of the four main raspberry cultivars being grown at that time (Autumn Bliss, Glen Moy, Glen Prosen and Leo), in Loganberry and in Tayberry. Fifteen RBDV genotypes (including two that appeared to be mixed) were identified using RT-PCR/RFLPs, but the majority of genotypes were found only rarely. Of the RBDV isolates tested, two genotypes each comprised 12·5% and another 46·4%. None of the three most common genotypes was associated solely with single Rubus cultivars and vice versa. It is suggested that two separate outbreaks of RBDV are occurring in England and Wales. One outbreak comprises the most frequent genotype combined with one of the moderately frequent genotypes; this outbreak is largely confined to the main growing areas and is either spreading between farms or coming from multiple local sources. Circumstantial evidence suggests that these isolates (and hence this first outbreak) are of the RB pathotype. The second outbreak consists of the other moderately frequent genotype and those genotypes which are less common. These genotypes appear to be more scattered across England and Wales and seem more likely to be coming from local sources and not to be spreading naturally between commercial farms. [source] Testing the Home-Site Advantage in Forest Trees on Disturbed and Undisturbed SitesRESTORATION ECOLOGY, Issue 3 2010Eleanor K. O'Brien Restoration of plant populations is often undertaken using seed or plants from local sources because it is assumed they will be best adapted to the prevailing conditions. However, the effect of site disturbance on local adaptation has rarely been examined. We assessed local adaptation in three southwestern Australian forest tree species (Eucalyptus marginata, Corymbia calophylla, and Allocasuarina fraseriana) using reciprocal transplant trials at disturbed and undisturbed sites. Performance of plants within the trials was assessed over 2 years. Planting location accounted for the majority of the variation in most measures of performance, although significant variation of percent emergence among source populations was also detected. In all species, percent emergence and survival of plants sourced from Darling Range populations was significantly higher than that of plants from the Swan Coastal Plain, regions of contrasting edaphic and climatic environment. Survival of E. marginata over the first 18 months and emergence of C. calophylla were both higher in local plants, providing at least weak evidence for local adaptation. Where a local advantage was observed, the relative performance of local and nonlocal seed did not vary among disturbed and undisturbed sites. Evidence for enhanced establishment from local seed in at least one species leads us to recommend that where sufficient high-quality seed supplies exist locally, these should be used in restoration. We also recommend longer-term studies to include the possibility of local adaptation becoming evident at later life history stages. [source] Residencies in Addiction Psychiatry: 1990 to 2000, A Decade of ProgressTHE AMERICAN JOURNAL ON ADDICTIONS, Issue 3 2002Marc Galanter M.D. This article reviews the history and status of addiction psychiatry residencies based on surveys conducted in 1990 and again in 1999. The 19 of 38 approved programs in operation since 1990 filled more positions than those that were more recently accredited, but they were not significantly different in time allocated to respective clinical assignments or in salary support. Altogether, the programs provide a broad array of training sites (inpatient and outpatient, alcohol and other-drug related) suitable for the diverse needs that graduates will encounter. There were, however, differences in the balance of time dedicated to research relative to patient care. Salaries were relatively modest and drawn from federal and local sources. [source] PHYSICOCHEMICAL COMPOSITIONAL ANALYSIS OF CERAMICS: A CASE STUDY IN KENTING, TAIWAN,ARCHAEOMETRY, Issue 4 2006MAA-LING CHEN The composition of ceramics does not just reflect the component of some specific, unprocessed, geological, raw material source, but also certain forms of human behaviour involved in its manufacture. The purpose of this research project is to apply the acid-extraction chemical method, complemented by a thin-section petrographic study, to the compositional analyses of certain local ceramic collections (mainly from several sites in the southern Taiwan area). The results present the raw materials that the ceramic manufacturers of the two cultural traditions (O-laun-pi Phase II and Phase III,IV), which overlapped temporally, used. These materials came from the same sources, but the ceramics were manufactured in different ways. Particularly, the people of O-laun-pi Phase III,IV also procured certain materials from either local sources or from somewhere in eastern Taiwan to make their pots. The results also indicate that there might have been a variation in terms of their manufacture among sites of the same cultural tradition. [source] From hypothetical scenario to tragic reality: A salutary lesson in risk communication and the Victorian 2009 bushfiresAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 1 2010Robin Burns Abstract Objective: To investigate the ways that the risk of a bushfire emergency and communication strategies are perceived by different community segments. Methods: A brief questionnaire preceded focus group discussion of a bushfire scenario with four communications from different sources. Groups were recruited to represent different community segments within a bushfire-prone peri-urban Shire in Victoria. Results: Four groups (28 participants) were recruited. Bushfire experience was highest in the over 40-year-olds, who would use a variety of information sources, preferred to receive information from trusted local sources, such as emergency services and the council, and were more likely to be a member of a local organisation than the under 40s. Younger people used television, local papers, and friends, family and neighbours as information sources. Young parents felt disempowered through lack of local knowledge, and trusted government departments less than older residents. All wanted clear, current, specific local information about ground conditions and actions to be taken during a fire outbreak. Conclusions/implications: Knowledge of and preparedness for bushfire is unequally spread throughout a bushfire community. There is a need in public health risk and emergency situations to focus on community development, information and consultation. [source] Testing long-term patterns of basin sedimentation by detrital zircon geochronology, Centralian Superbasin, AustraliaBASIN RESEARCH, Issue 3 2007D. W. Maidment ABSTRACT Detrital zircon geochronology of Neoproterozoic to Devonian sedimentary rocks from the Georgina and Amadeus basins has been used to track changes in provenance that reflect the development and inversion of the former Australian Superbasin. Through much of the Neoproterozoic, sediments appear to have been predominantly derived from local sources in the Arunta and Musgrave inliers. Close similarities between the detrital age signatures of late Neoproterozoic sedimentary rocks in the two basins suggests that they were contiguous at this time. A dominant population of 1.2,1.0 Ga zircon in Early Cambrian sediments of the Amadeus Basin reflects the uplift of the Musgrave Inlier during the Petermann Orogeny between 560 and 520 Ma, which shed a large volume of detritus northwards into the Amadeus Basin. Early Cambrian sedimentary rocks in the Georgina Basin have a much smaller proportion of 1.2,1.0 Ga detritus, possibly due to the formation of sub-basins along the northern margin of the Amadeus Basin which might have acted as a barrier to sediment transfer. An influx of 0.6,0.5 Ga zircon towards the end of the Cambrian coincides with the transgression of the Larapintine Sea across central Australia, possibly as a result of intracratonic rifting. Detrital zircon age spectra of sedimentary rocks deposited within this epicontinental sea are very similar to those of coeval sedimentary rocks from the Pacific Gondwana margin, implying that sediment was transported into central Australia from the eastern continental margin. The remarkably consistent ,Pacific Gondwana' signature of Cambro-Ordovician sediments in central and eastern Australia reflects a distal source, possibly from east Antarctica or the East African Orogen. The peak of the marine incursion into central Australia in the early to mid Ordovician coincides with granulite-facies metamorphism at mid-crustal depths between the Amadeus and Georgina basins (the Larapinta Event). The presence of the epicontinental sea, the relative lack of a local basement zircon component in Cambro-Ordovician sedimentary rocks and their maturity suggest that metamorphism was not accompanied by mountain building, consistent with an extensional or transtensional setting for this tectonism. Sediments deposited at ,435,405 and ,365 Ma during the Alice Springs Orogeny have detrital age signatures similar to those of Cambro-Ordovician sedimentary rocks, reflecting uplift and reworking of the older succession into narrow foreland basins adjacent to the orogen. 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