The geography of regional websites: Regional representation and regional structure     

Kees Terlouw  Ronny Denkers 《Geoforum》2011,42(5):578-591

Regional administrations present themselves in many different ways on the internet. A content analysis of regional websites in the Netherlands and Northwest Germany revealed this diversity. Geographical factors can partly explain these differences. Mapping the five principal aspects of the geographical representations of regional administrations revealed some spatial clusters. These regional representations are also linked to the geographical characteristics of regions. Competitive mid-sized regions focus more on economic items. Different types of peripheries vary much more in how they present themselves on the internet. The way regions present themselves is linked to the polarising influence of regional competition, but there is still considerable freedom for regions to present a distinct region image.  相似文献   

Assessing the impact of major oil spills on seabird populations     

Heubeck M  Camphuysen KC  Bao R  Humple D  Sandoval Rey A  Cadiou B  Bräger S  Thomas T 《Marine pollution bulletin》2003,46(7):900-902

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The Vicência meteorite fall: A new unshocked (S1) weakly metamorphosed (3.2) LL chondrite          下载免费PDF全文

Klaus Keil  Maria E. Zucolotto  Alexander N. Krot  Patricia M. Doyle  Myriam Telus  Tatiana V. Krot  Richard C. Greenwood  Ian A. Franchi  John T. Wasson  Kees C. Welten  Marc W. Caffee  Derek W. G. Sears  My Riebe  Rainer Wieler  Edivaldo dos Santos  Rosa B. Scorzelli  Jerome Gattacceca  France Lagroix  Matthias Laubenstein  Julio C. Mendes  Philippe Schmitt‐Kopplin  Mourad Harir  Andre L. R. Moutinho 《Meteoritics & planetary science》2015,50(6):1089-1111

The Vicência meteorite, a stone of 1.547 kg, fell on September 21, 2013, at the village Borracha, near the city of Vicência, Pernambuco, Brazil. It was recovered immediately after the fall, and our consortium study showed it to be an unshocked (S1) LL3.2 ordinary chondrite. The LL group classification is based on the bulk density (3.13 g cm^?3); the chondrule mean apparent diameter (0.9 mm); the bulk oxygen isotopic composition (δ¹⁷O = 3.768 ± 0.042‰, δ¹⁸O = 5.359 ± 0.042‰, Δ¹⁷O = 0.981 ± 0.020‰); the content of metallic Fe,Ni (1.8 vol%); the Co content of kamacite (1.73 wt%); the bulk contents of the siderophile elements Ir and Co versus Au; and the ratios of metallic Fe⁰/total iron (0.105) versus total Fe/Mg (1.164), and of Ni/Mg (0.057) versus total Fe/Mg. The petrologic type 3.2 classification is indicated by the beautifully developed chondritic texture, the standard deviation (~0.09) versus mean Cr₂O₃ content (~0.14 wt%) of ferroan olivine, the TL sensitivity and the peak temperature and peak width at half maximum, the cathodoluminescence properties of chondrules, the content of trapped ¹³²Xe_tr (0.317 × 10^?8cm³STP g^?1), and the Raman spectra for organic material in the matrix. The cosmic ray exposure age is ~72 Ma, which is at the upper end of the age distribution of LL group chondrites. The meteorite is unusual in that it contains relatively large, up to nearly 100 μm in size, secondary fayalite grains, defined as olivine with Fa_>75, large enough to allow in situ measurement of oxygen and Mn‐Cr isotope systematics with SIMS. Its oxygen isotopes plot along a mass‐dependent fractionation line with a slope of ~0.5 and Δ¹⁷O of 4.0 ± 0.3‰, and are similar to those of secondary fayalite and magnetite in the unequilibrated chondrites EET 90161, MET 96503, and Ngawi. These data suggest that secondary fayalite in Vicência was in equilibrium with a fluid with a Δ¹⁷O of ~4‰, consistent with the composition of the fluid in equilibrium with secondary magnetite and fayalite in other unequilibrated ordinary chondrites. Secondary fayalite and the chondrule olivine phenocrysts in Vicência are not in isotopic equilibrium, consistent with low‐temperature formation of fayalite during aqueous alteration on the LL parent body. That alteration, as dated by the ⁵³Mn‐⁵³Cr chronology age of secondary fayalite, took place $4.0{}_{?1.1}^{+1.4}$ Ma after formation of CV CAIs when anchored to the quenched angrite D'Orbigny.  相似文献   

High-resolution depth imaging with sparseness-constrained inversion   总被引：2，自引：0，他引：2  

Jianfeng Zhang  Kees Wapenaar 《Geophysical Prospecting》2006,54(1):49-62

An imaging technique is developed which exceeds the resolution limitation prescribed by conventional seismic imaging methods. The high‐resolution imaging is obtained by introducing a sparseness‐constrained least‐squares inversion into the imaging process of prestack depth migration. This is implemented by a proposed interference technique. In contrast to conventional depth migration, a decomposed signal or combined event, instead of the source wavelet, is needed in the proposed scheme. The proposed method aims to image a small local region with a higher resolution using the prestack data set. It should be applied following conventional depth imaging if a higher resolution is needed in a target zone rather than replacing the conventional depth imaging for the entire medium. Synthetic examples demonstrate the significant improvements in the resolution using the proposed scheme.  相似文献   

It is a moral issue: The relationship between environmental self-identity,obligation-based intrinsic motivation and pro-environmental behaviour     

Ellen van der Werff  Linda Steg  Kees Keizer 《Global Environmental Change》2013,23(5):1258-1265

In order to effectively mitigate climate change, people need to adopt environmentally-friendly actions. We argue that some people act in an environmentally-friendly manner without external incentives to do so, but rather because they are intrinsically motivated to do so. There is some initial evidence to suggest that this is particularly likely for people with a strong environmental self-identity. However, not much is known about how environmental self-identity influences pro-environmental actions. In this research, we aimed to test whether, and if so, via which process environmental self-identity is related to environmentally-friendly behaviour. We conducted three studies to test our hypotheses. In the first study, our hypotheses were confirmed in a sample of the general population using a correlational design. In the second study, we replicated our findings with a different indicator of moral obligation and with a different dependent variable. In the third study, we tested our model in an experimental design. Again, we found support for our hypotheses that environmental self-identity is related to one's obligation-based intrinsic motivation (that is, feelings of moral obligation) to act pro-environmentally, which in turn affects pro-environmental actions. As expected, the obligation-based intrinsic motivation mediates the relationship between environmental self-identity and environmentally-friendly behaviour. Our findings suggest that strengthening environmental self-identity may be a cost-effective way to promote pro-environmental actions, as people with a strong environmental self-identity are likely to act in an environmentally-friendly manner without an external incentive to do so.  相似文献   

Analytic modeling of groundwater dynamics with an approximate impulse response function for areal recharge     

Mark Bakker  Kees Maas  Frans Schaars  Jos R. von Asmuth 《Advances in water resources》2007

An analytic approach is presented for the simulation of variations in the groundwater level due to temporal variations of recharge in surficial aquifers. Such variations, called groundwater dynamics, are computed through convolution of the response function due to an impulse of recharge with a measured time series of recharge. It is proposed to approximate the impulse response function with an exponential function of time which has two parameters that are functions of space only. These parameters are computed by setting the zeroth and first temporal moments of the approximate impulse response function equal to the corresponding moments of the true impulse response function. The zeroth and first moments are modeled with the analytic element method. The zeroth moment may be modeled with existing analytic elements, while new analytic elements are derived for the modeling of the first moment. Moment matching may be applied in the same fashion with other approximate impulse response functions. It is shown that the proposed approach gives accurate results for a circular island through comparison with an exact solution; both a step recharge function and a measured series of 10 years of recharge were used. The presented approach is specifically useful for modeling groundwater dynamics in aquifers with shallow groundwater tables as is demonstrated in a practical application. The analytic element method is a gridless method that allows for the precise placement of ditches and streams that regulate groundwater levels in such aquifers; heads may be computed analytically at any point and at any time. The presented approach may be extended to simulate the effect of other transient stresses (such as fluctuating surface water levels or pumping rates), and to simulate transient effects in multi-aquifer systems.  相似文献   

Periglacial microjointing and faulting in Weichselian fluvio-aeolian deposits     

Joanne Mol  Jef Vandenberghe  Kees Kasse  Harry Stel 《第四纪科学杂志》1993,8(1):15-30

A Weichselian Late Pleniglacial fluvio-aeolian deposit has been investigated in the southern Netherlands. Three main structural lineaments have been distinguished: (1) very small, vertical platy structures (microjoints), in a parallel and a columnar configuration; (2) large joints and normal faults with minor displacement (‘Grubbenvorst type’), arranged in a conjugate fault-system; (3) large joints and normal faults (‘wedge-type’), located adjacent to ice-wedge casts. Since clay is absent, the occurrence of the vertical platy structures cannot be attributed to desiccation cracking. The vertical platy structures are interpreted as the result of thermal contraction cracking of a relatively thin layer, due to a sudden temperature drop. The large joints and normal faults of the Grubbenvorst type are the result of failure of the sediment due to the melting of the permafrost in the Late Pleniglacial, just before the formation of the Beuningen Gravel Bed. In other areas large periglacial convolutions have been formed during the same period. The normal faults and joints of the wedge type are more generally known. They are the result of failure of the sediment adjacent to a melting ice wedge.  相似文献   

Identifying Environmental and Human Factors Associated With Tick Bites using Volunteered Reports and Frequent Pattern Mining   总被引：1，自引：0，他引：1       下载免费PDF全文

Irene Garcia‐Martí  Raul Zurita‐Milla  Arno Swart  Kees C. van den Wijngaard  Arnold J.H. van Vliet  Sita Bennema  Margriet Harms 《Transactions in GIS》2017,21(2):277-299

Tick populations and tick‐borne diseases like Lyme borreliosis have been steadily increasing since the mid‐1990s. Realizing the threat that ticks pose to public health, two Dutch citizen science projects have collected tick bite reports since 2006. This unique volunteered geographical dataset, which currently has nearly 35,000 reports, was used to identify environmental and other circumstantial factors associated with tick bites. For this, we first enriched the tick bite reports with temperature, precipitation, vegetation and volunteered data associated with the location of the tick bite. Using this enriched dataset, we then derived a series of features to characterize the environmental and volunteer‐related conditions in which each tick bite occurred. Next, we discretized these features using the Jenks Natural Breaks algorithm and, after that, we mined frequent environmental patterns associated with tick bites using the AprioriClose algorithm. Finally, we checked that these patterns are specifically associated with the tick bites by comparing them with the frequent patterns mined from pseudo‐random locations. The frequent patterns were visualized using heat maps and ring maps and two representative patterns associated with tick bites were projected into geographic space to study their spatio‐temporal distribution. Our results show that factors linked to human activity are more relevant to model tick bites than seasonal accumulations of temperature, vegetation or precipitation. In particular, the number of warm and dry days per season are present in a significant number of patterns and the majority of tick bites are produced within a distance of half a kilometer of a forest, recreational or built‐up area. The study of patterns in the time‐series revealed that there are several persistent patterns consistently occurring each year and the validation process showed that the volunteer tick bites collection is capturing environmental conditions associated with tick bites, suggesting that these reports have a high scientific value. These results support the creation of a Dutch tick bite risk map that, in turn, will open the door to the design of public health interventions to reduce the incidence of Lyme disease.  相似文献   

Structure of the Mid Atlantic Ridge province between 12° and 18°N     

Bastiaan J. Collette  Hans Schouten  Kees Rutten  A. Peter Slootweg 《Marine Geophysical Researches》1974,2(2):143-179

An analysis is given of air-gun profiler and magnetic data obtained in the central North Atlantic between 12° and 18°N. Eight fracture zones were crossed, one of which (the 15°20N fracture zone) was traced over a distance of 1500 km. The mode of adjustment of fracture zones to a change in direction of spreading is discussed. It is shown that also if this new direction would lead to an opening of the fracture zone, and adjustment fracture can originate and actually does so in several instances.The about E-W fracture zones dominate the structure of the Ridge province entirely, both with regard to the topography and to the magnetics. A magnetic model is proposed accounting for the different types of anomalies found over fracture zones. No intrusive bodies are needed to explain these anomalies.The origin of fracture zones is related to thermal contraction of a cooling lithosphere while moving from the ridge. Thermal contraction may also explain how the American and the African plates are freed from the grip they are caught in by the fanning of the fracture zones in the central North Atlantic. The fanning of fracture zones has consequences for the determination of the pole of spreading. This pole can only be found as a best fit from a synthesis of the total plate boundary, i.e. from the Azores to Bouvet Island. Local poles have only restricted value, since deviations up to 5 deg occur from a small circle pattern based on existing data.Several huge structures, viz. Researcher Ridge and Royal Trough, are found in the area which seem to parallel the flow lines of the fracture zone system. No adequate explanation exists for these structures.  相似文献   

Diet studies of seabirds: a review and recommendations   总被引：8，自引：0，他引：8  

Barrett  Robert T.; Camphuysen  Kees ; Anker-Nilssen  Tycho; Chardine  John W.; Furness  Robert W.; Garthe  Stefan; Huppop  Ommo; Leopold  Mardik F.; Montevecchi  William A.; Veit  Richard R. 《ICES Journal of Marine Science》2007,64(9):1675-1691

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