Producing regionalism: regional movements, ecosystems and equity in a fast and slow growth region     

Gerda R. Wekerle  Teresa V. Abbruzzese 《GeoJournal》2010,75(6):581-594

Urban development pressures, preservation of environmentally sensitive areas and regional planning are the focus of current debates on regionalism in both fast and slow growth regions. Based on two cases—a campaign to preserve ecological integrity and reduce sprawl on the Oak Ridges Moraine in the Greater Toronto Area and Rochester’s anti-sprawl campaign for regional equity—the paper examines how two anti-sprawl campaigns brought to the fore alternative constructions of regionalism. In the fast growing Toronto region, citizen mobilization and upper tier intervention resulted in a legislative base for regionalism. In the slow growth Rochester region, the city had limited success in gaining regional redistribution. Such divergent outcomes relate to differences in intergovernmental relations, the city’s influence on the region, receptivity of suburbs to smart growth, and the potential for values of nature preservation and justice to mobilize regional coalitions.  相似文献   

Deep-sea bacterial communities in sediments and guts of deposit-feeding holothurians in Portuguese canyons (NE Atlantic)     

Teresa Amaro  Harry Witte  Gerhard J. Herndl  Marina R. Cunha  David S.M. Billett 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(10):1834-1843

Deposit-feeding holothurians often dominate the megafauna in bathyal deep-sea settings, in terms of both abundance and biomass. Molpadia musculus is particularly abundant at about 3400 m depth in the Nazaré Canyon on the NE Atlantic Continental Margin. However, these high abundances are unusual for burrowing species at this depth. The objective of this research was to understand the reasons of the massive occurrence of these molpadiid holothurians in the Nazaré Canyon. To address this question we investigated possible trophic interactions with bacteria at sites where the organic content of the sediment was different (Setúbal and Cascais Canyons, NE Atlantic Continental Margin). The molecular fingerprinting technique of Denaturing Gradient Gel Electrophoresis (DGGE) with band sequencing, combined with non-metric multi-dimensional scaling and statistical analyses, was used to compare the bacterial community diversity in canyon sediments and holothurian gut contents. Our results suggest that M. musculus does not need to develop a specialised gut bacterial community to aid digestion where the sediment is rich in organic matter (Nazaré Canyon); in contrast, such a community may be developed where the sediment is poorer in organic matter (Cascais Canyon).  相似文献   

Exudates of different marine algae promote growth and mediate trace metal binding in Phaeodactylum tricornutum     

Vasconcelos MT  Leal MF 《Marine environmental research》2008,66(5):499-507

Phaeodactylum tricornutum was grown in filtered natural seawater enriched with nitrate, phosphate, and silicate only (control) or with exudates from itself, from Emiliania huxleyi (a coccolithophore micro-alga), Porphyra spp. (a red macro-alga) or Enteromorpha spp. (a green macro-alga). Cathodic (and anodic) stripping voltammetry (C(A)SV) were used to determine the concentrations of trace metals, both in the medium and in the algae, as well as total Cu-complexing organic ligands in the medium and, among these, some thiols (compounds identified as cysteine- or as glutathione by CSV). Exudates of different marine micro- and macro-algae could cause allelopathic effects in P. tricornutum cultures. Cell yield of P. tricornutum was increasingly promoted by exudates of E. huxleyi >Porphyra >Enteromorpha. Although exudates strongly complex Cu (and probably other metals), their presence promoted Cu uptake. Significant changes of Ni, Cd, Fe, Zn and Mn uptake by P. tricornutum were also observed in the presence of exudates of different algal species. In addition, both intensity of production and nature of exudates released by P. tricornutum were markedly influenced by the presence of exudates of other algae, the allelopathic effects being very specific (variable from one species to another). Allelopathy will probably also occur in the aquatic environment, although to a lesser extent than in cultures, particularly during bloom events and may have effects on both chemical speciation and bioavailability of chemicals to phytoplanktonic species. Such changes might cause the predominance of some species over other species. Therefore, in future in vitro culture studies with the purpose of using them as models of the real environment, more attention should be paid to the role of algal exudates, in order to improve the environmental relevance and significance of the results.  相似文献   

Validation of Geant4 10.3 simulation of proton interaction for space radiation effects     

Vladimir Ivanchenko  Paolo Dondero  Valentina Fioretti  Anton Ivantchenko  Fan Lei  Simone Lotti  Alfonso Mantero  Teresa Mineo 《Experimental Astronomy》2017,44(3):437-450

Monte Carlo simulation of space radiation effects induced by protons is important for design of space missions. Geant4 is a well established toolkit for Monte Carlo simulation focused on high energy physics applications. In this work, a set of new validation results versus data for Geant4 electromagnetic and hadronic interaction of protons is presented and discussed. Optimal configuration of Geant4 physics for space applications is proposed.  相似文献   

Reappraisal of the GL‐O Reference Material for K‐Ar Dating: New Insight from Microanalysis,Single‐Grain and Milligram Ar Measurements     

Thomas Boulesteix  Jesús Sol  Teresa Pi  Michel Cathelineau 《Geostandards and Geoanalytical Research》2020,44(2):287-306

The homogeneity and Ar‐dating suitability of the GL‐O reference material were re‐evaluated to determine whether this material is sufficiently homogeneous to be suitable for the calibration of modern high sensitivity instruments. Based on new micro‐analyses and noble gas determinations, our contribution reveals several kinds of inhomogeneity at the grain scale: disparity in the glauconitisation among and within the pellets, variable occurrence of a phosphatic component within pellets (1% m/m on average), and rare occurrences of calcite and detrital grains. Measurements on test portions of ≤ 1 mg reflect such heterogeneity with variability in ⁴⁰Ar* content that exceeds analytical uncertainty, including a few highly anomalous values. The lesser evolved glauconite population yielded ⁴⁰Ar* contents ~ 15% lower than the value of 24.8 nl g^?1 recommended by Odin et al. (1982, Numerical dating in stratigraphy. Wiley (Chichester, UK), 123–148). But the measured concentrations of ⁴⁰Ar* converge towards the aforementioned value as test portion mass increased to > 3 mg. A few rare 3 mg experiments still yielded ⁴⁰Ar* contents lower than the recommended value (down to 24.0 nl g^?1), and we recommend using more conservative minimum masses of 5–10 mg. A further purification step for GL‐O or the intercalibration of its powder version could be considered to diminish the size of the test portions and the intensity of the measured signals.  相似文献   

Fitting and Reconstruction of Thirteen Simple Coronal Mass Ejections     

Nada Al-Haddad  Teresa Nieves-Chinchilla  Neel P. Savani  Noé Lugaz  Ilia I. Roussev 《Solar physics》2018,293(5):73

Coronal mass ejections (CMEs) are the main drivers of geomagnetic disturbances, but the effects of their interaction with Earth’s magnetic field depend on their magnetic configuration and orientation. Fitting and reconstruction techniques have been developed to determine important geometrical and physical CME properties, such as the orientation of the CME axis, the CME size, and its magnetic flux. In many instances, there is disagreement between different methods but also between fitting from in situ measurements and reconstruction based on remote imaging. This could be due to the geometrical or physical assumptions of the models, but also to the fact that the magnetic field inside CMEs is only measured at one point in space as the CME passes over a spacecraft. In this article we compare three methods that are based on different assumptions for measurements by the Wind spacecraft for 13 CMEs from 1997 to 2015. These CMEs are selected from the interplanetary coronal mass ejections catalog on https://wind.nasa.gov/ICMEindex.php because of their simplicity in terms of: 1) slow expansion speed throughout the CME and 2) weak asymmetry in the magnetic field profile. This makes these 13 events ideal candidates for comparing codes that do not include expansion or distortion. We find that for these simple events, the codes are in relatively good agreement in terms of the CME axis orientation for six of the 13 events. Using the Grad–Shafranov technique, we can determine the shape of the cross-section, which is assumed to be circular for the other two models, a force-free fitting and a circular–cylindrical non force-free fitting. Five of the events are found to have a clear circular cross-section, even when this is not a precondition of the reconstruction. We make an initial attempt at evaluating the adequacy of the different assumptions for these simple CMEs. The conclusion of this work strongly suggests that attempts at reconciling in situ and remote-sensing views of CMEs must take into consideration the compatibility of the different models with specific CME structures to better reproduce flux ropes.  相似文献   

New Zealand's small town transition: The experience of demographic and economic change and place based responses     

Etienne Nel  Sean Connelly  Teresa Stevenson 《New Zealand geographer》2019,75(3):163-176

A significant percentage of the smaller urban centres around the world are losing people which raises questions regarding the appropriate responses to this challenge. Responses from the state have generally been muted, and as a result, concepts of new localism and new regionalism are useful for understanding the role played by place‐based leadership and partnerships between local businesses, community groups and individuals. Key within this space is the role of endogenous responses anchored on local social capital and resilience. This paper overviews key themes in the literature before examining statistical evidence of small town growth, stabilisation or decline in New Zealand. This leads into an examination of how three small towns in the country are responding to demographic and economic change. The cases illustrate the importance of local‐led responses to the debilitating effects of change and the degree to which place based development can be critical in the context of coping with change in small towns. The paper further argues that “right‐sizing” to a new economic and demographic reality may be the appropriate focus of local attention.  相似文献   

Sublimation Mechanisms of Comet Nuclei     

Capria  Maria Teresa 《Earth, Moon, and Planets》2000,89(1-4):161-178

In this paper the sublimation mechanisms of parent molecules from nuclei will be reviewed from the point of view of theoretical models, and the results of models will be compared with the results of the extensive observation campaign of C/1995 O1 Hale-Bopp. The simple model of a mixture of ices in which each gas sublimates independently from the others when the right temperature has been reached is in many cases inadequate to explain the observations. Many minor volatiles can be trapped in the amorphous water ice and released in a complex way when particular ranges of temperature are reached. The presence of sublimating icy grains in the inner coma of comets, suggested many years ago, seems now to be proven, at least for Hale-Bopp. From these grains a significant amount of water and other volatiles could contribute to the total flux measured in the coma. The unprecedented coverage of Hale-Bopp’s gas production curve for such a long time and with so many instrumentshas offered to modellers a wonderful occasion to test and compare observation results with the predictions of sublimation models, demonstrating that current models are able to explain observed results.  相似文献   

Spatial and seasonal variations of the macrobenthic community and metal contamination in the Douro estuary (Portugal)   总被引：3，自引：0，他引：3  

Mucha AP  Vasconcelos MT  Bordalo AA 《Marine environmental research》2005,60(5):531-550

The macrobenthic community structure and characteristics of sediments were studied in samples collected seasonally at five stations in the lower mesotidal Douro estuary, Portugal. Sediment characterisation included grain size distribution, total-recoverable metals (Al, Fe, Mn, Zn, Cu, Cr, Pb, Ni and Cd), acid-volatile sulphides (AVS) and simultaneously extracted metals (SEM) and total organic matter contents. Spatial variation surpassed temporal variation both in terms of environmental parameters and community structure. Clear anthropogenic contamination in terms of Zn, Cr, Cu and Pb, and a positive SEM-AVS, indicating the potential bioavailability of these metals, were detected on the north bank of the estuary. Multivariate analysis revealed that in addition to natural sediment characteristics, the anthropogenic metal contamination was influencing the macrobenthic community structure. In fact, greater concentrations of Zn, Cr, Cu and Pb were associated with lower number of species and/or diversity. Finally, the dry weight-normalised metal concentrations appeared as a more useful tool than the SEM-AVS model in predicting disturbance of the macrobenthic community in the studied area.  相似文献   

Does multiclustering of galaxy aggregates appear as a specific coil of extragalactic data unseparated from interpretations of the role of interstellar obscuration?     

Teresa Grabińska  Mirosław Zabierowski 《Astrophysics and Space Science》1987,137(2):403-406

The use of a cosmic potential in relativistic cosmology is criticized. It is pointed out that the energetic closure of the Universe follows from general relativity and from quantized superspace cosmology without the introduction of the cosmic potential.  相似文献