bluuebunny/crossref_metadata_2025 huggingface dataset:
How much of the seabed is impacted by mobile fishing gear? Absolute estimates from Vessel Monitoring System (VMS) point data
Authors: Gerritsen Hans D. , Minto Cóilín , Lordan Colm
Published: February 2013

Gerritsen, H. D., Minto, C., and Lordan, C. 2013. How much of the seabed is impacted by mobile fishing gear? Absolute estimates from Vessel Monitoring System (VMS) point data. – ICES Journal of Marine Science, 70: 523–531. Demersal trawling impacts extensively on the seabed, and the extent and frequency of this impact can be assessed using Vessel Monitoring System (VMS) data (positional data of fishing vessels). Existing approaches interpolate fishing tracks from consecutive VMS locations (track interpolation) and/or aggregate VMS point data in a spatial grid (point summation). Track interpolation can be quite inaccurate with the current 2-hour time interval between VMS records, leading to biased estimates. Point summation approaches currently only produce relative estimates of impact and are highly sensitive to the grid size chosen. We propose an approach that provides absolute estimates of trawling impact from point data and is not sensitive to an arbitrary choice of grid-cell size. The method involves applying a nested grid and estimating the swept area (area covered by fishing gear) for each VMS point. We show that the ratio of the swept area to the surface area of a cell can be related to the proportion of the seabed that was impacted by the gear a given number of times. We validate the accuracy of this swept-area ratio approach using known vessel tracks and apply the method to international VMS data in the Celtic Sea.
Modelling the influence of daytime distribution on the transport of two sympatric krill species (Thysanoessa raschii and Meganyctiphanes norvegica) in the Gulf of St Lawrence, eastern Canada
Authors: Maps Frédéric , Plourde Stéphane , Lavoie Diane , McQuinn Ian , Chassé Joël
Published: February 2013

Maps, F., Plourde, S., Lavoie, D., McQuinn, I., and Chassé, J. 2014. Modelling the influence of daytime distribution on the transport of two sympatric krill species (Thysanoessa raschii and Meganyctiphanes norvegica) in the Gulf of St Lawrence, eastern Canada. – ICES Journal of Marine Science, 71: 282–292. The Gulf of St Lawrence (GSL) provides several species of North Atlantic baleen whale with an abundant supply of krill, dominated by Thysanoessa raschii and Meganyctiphanes norvegica. We aimed to quantify the differences in upstream advection resulting from the interaction between the circulation and the specific diel vertical migration of T. raschii and M. norvegica at the scale of the northwest GSL. We coupled a regional circulation model with Lagrangian models where the daytime depth followed specific functions of surface salinity. Our results help to explain the spatio-temporal variability in both T. raschii and M. norvegica distributions. We identified in particular spatio-temporal patterns in krill upstream transport. During summer and autumn, the upstream transport of krill is steady across Jacques Cartier Strait, limited across Honguedo Strait, and more sporadic across the Estuary mouth. We estimated that the upstream advection of krill particles across the Estuary mouth would be higher by 16–17% for the T. raschii than for the M. norvegica daytime behaviour. Our results also suggest that the advective processes operating on the adults during the productive season are not the only cause for the observed magnitude of the interannual and interspecific variability in krill abundance.
The second wave of digital-era governance: a quasi-paradigm for government on the Web
Authors: Margetts Helen , Dunleavy Patrick
Published: February 2013

Widespread use of the Internet and the Web has transformed the public management ‘quasi-paradigm’ in advanced industrial countries. The toolkit for public management reform has shifted away from a ‘new public management’ (NPM) approach stressing fragmentation, competition and incentivization and towards a ‘digital-era governance’ (DEG) one, focusing on reintegrating services, providing holistic services for citizens and implementing thoroughgoing digital changes in administration. We review the current status of NPM and DEG approaches, showing how the development of the social Web has already helped trigger a ‘second wave’ of DEG2changes. Web science and organizational studies are converging swiftly in public management and public services, opening up an extensive agenda for future redesign of state organization and interventions. So far, DEG changes have survived austerity pressures well, whereas key NPM elements have been rolled back.
Some assembly required: leveraging Web science to understand and enable team assembly
Authors: Contractor Noshir
Published: February 2013

Recent advances on the Web have generated unprecedented opportunities for individuals around the world to assemble into teams. And yet, because of the Web, the nature of teams and how they are assembled has changed radically. Today, many teams are ad hoc, agile, distributed, transient entities that are assembled from a larger primordial network of relationships within virtual communities. These assemblages possess the potential to unleash the high levels of creativity and innovation necessary for productively addressing many of the daunting challenges confronting contemporary society. This article argues that Web science is particularly well suited to help us realize this potential by making a substantial interdisciplinary intellectual investment in (i) advancing theories that explain our socio-technical motivations to form teams, (ii) the development of new analytic methods and models to untangle the unique influences of these motivations on team assembly, (iii) harvesting, curating and leveraging the digital trace data offered by the Web to test our models, and (iv) implementing recommender systems that use insights gleaned from our richer theoretical understanding of the motivations that lead to effective team assembly.
Glow and Dust in Plasma Boundaries
Authors: Land Victor , Douglass Angela , Qiao Ke , Zhang Zhuanhao , Matthews Lorin , Hyde Truell
Published: February 2013

The sheath region is probed in different complex plasma experiments using dust particles in addition to the measurement of the optical emission originating from the plasma. The local maximum in the optical emission coincides with the breaking of quasi-neutrality at the sheath boundary, as indicated by the vertical-force profile reconstructed from dust-particle trajectories as well as by the local onset of dust-density waves in high-density dust clouds suspended in a dielectric box.
Evaluating ecosystem goods and services after restoration of marginal upland peatlands in South‐West England
Authors: Grand‐Clement Emilie , Anderson Karen , Smith David , Luscombe David , Gatis Naomi , Ross Martin , Brazier Richard E.
Published: February 2013

In the UK, drainage for agricultural reclamation during the 19th and 20th centuries is responsible for an alteration of the ecological and hydrological functioning of peatlands, in turn, affecting a whole suite of ecosystem services. Today, initiatives are in place throughout the UK to reinstate this eco‐hydrological functioning by blocking drainage ditches. Effects on ecosystem services remain unclear, as does the overlapping impact of climate change on peatland recovery.

This article uses a conceptual model to present the effects of restoration on ecosystem services, that is, water provision and quality, carbon storage, biodiversity, food and fibre provision and cultural services, both immediately after ditch blocking and in the few years post‐restoration. The model is then applied in the context of Exmoor National Park, in South West England and used to perform a cost–benefit analysis of the restoration and monitoring programme, as these shallow peatlands are located in geographically marginal areas, and therefore more sensitive to climate change.

Past research indicates that some processes tend to return progressively to their predisturbance state, but whether the complete recovery of peatlands to functioning mires occurs after restoration remains unclear, partly due to the difference between the temporal and spatial scale at which processes occur (i.e. up to decadal) and are monitored (typically a few years).

Overall, on Exmoor, the long‐term benefit of peatland restoration to some ecosystem services, such as a reduction in carbon losses and improvement of water storage and quality, has the potential to balance high financial investment.

Synthesis and applications. Gaining a better understanding of the effects of peatland restoration on ecosystem services provided is essential to assess the potential value of restoration projects. Using the case of the shallow peatlands of Exmoor National Park, located in geographically marginal areas in the UK and therefore more vulnerable to the effects of climate change, we find that there is potential for both the value of carbon storage and water provision to offset the costs of restoration in the long‐term. Our results from Exmoor can provide ecological analogues of impending change further north.
The Regime of Informality in Neoliberal Times in Turkey: The Case of the Kadifekale Urban Transformation Project
Authors: Demirtas‐Milz Neslihan
Published: February 2013

Juxtaposing the empirical findings of a qualitative research study of an urban transformation project in the Kadifekale squatter district of Izmir with the changed nature of urban politics in a neoliberal context, this article aims to trace the manifestations of the regime of informality in Turkey. Ethnographic consideration of the motives behind these projects, the way they have been carried out and their consequences for the lives of the inhabitants points to an extended space for informal politics tactically manoeuvred by state officials of various ranks. Particularly during the last two decades, neoliberal urban policies have triggered an intensification of power discrepancies in both the vertical and horizontal dimensions and a fragmentation of community structure in the localities — mainly along socioeconomic divides. This research reveals a transition from positive/passive to negative/active uses of informality in the disposition of the state towards the urban poor when the fast and efficient conduct of urban transformation projects is in question. The characteristics of the locality as a landslide zone, the already fragmented socioeconomic structure in the neighbourhood and the dense presence of Kurdish immigrants facilitate the putting into practice of informal strategies. The immigrants who cannot define a place for themselves in the simultaneously formal and informal context of the project have been seriously disadvantaged.
De novo transcriptomic analyses for non‐model organisms: an evaluation of methods across a multi‐species data set
Authors: Singhal Sonal
Published: February 2013

High‐throughput sequencing (HTS) is revolutionizing biological research by enabling scientists to quickly and cheaply query variation at a genomic scale. Despite the increasing ease of obtaining such data, using these data effectively still poses notable challenges, especially for those working with organisms without a high‐quality reference genome. For every stage of analysis – from assembly to annotation to variant discovery – researchers have to distinguish technical artefacts from the biological realities of their data before they can make inference. In this work, I explore these challenges by generating a large de novo comparative transcriptomic data set data for a clade of lizards and constructing a pipeline to analyse these data. Then, using a combination of novel metrics and an externally validated variant data set, I test the efficacy of my approach, identify areas of improvement, and propose ways to minimize these errors. I find that with careful data curation, HTS can be a powerful tool for generating genomic data for non‐model organisms.
Minimum effective volume of ropivacaine 7.5 mg/ml for an ultrasound‐guided infraclavicular brachial plexus block
Authors: FLOHR‐MADSEN S. , YTREBØ L. M. , KREGNES S. , WILSGAARD T. , KLAASTAD Ø.
Published: February 2013

Background

Ultrasound guidance has been shown to reduce the minimum effective volume (MEV) of local anaesthetics for several peripheral nerve blocks. Although the lateral sagittal infraclavicular block (LSIB) is a well‐established anaesthesia method, MEV for this technique has not been established. Our aim with this study was to determine the MEV using ropivacaine 7.5 mg/ml for the LSIB method.

Methods

Twenty‐five adult American Society of Anesthesiologists physical status I‐II patients scheduled for hand surgery received an ultrasound‐guided LSIB with ropivacaine 7.5 mg/ml. A successful block was defined as anaesthesia or analgesia for all five sensory nerves distal to the elbow, 30 min after local anaesthetic injection. The MEV for a successful block in 50% of the patients was determined by using the staircase up‐and‐down method introduced by Dixon and Massey. Logistic regression and probit transformation were applied to estimate the MEV for a successful block in 95% of the patients.

Results

The patients received ropivacaine 7.5 mg/ml volumes in the range of 12.5–30 ml. The MEVs in 50% and 95% of the patients were 19 ml [95% confidence interval (CI), 14–27] and 31 ml (95% CI, 18–45), respectively.

Conclusions

For surgery distal to the elbow, the MEV in 95% of patients for an ultrasound‐guided LSIB with ropivacaine 7.5 mg/ml was estimated to be 31 ml (95% CI, 18–45 ml). Further studies should determine the factors that influence the volume of local anaesthetic required for a successful infraclavicular block.
A Pragmatist Defence of Classical Financial Accounting Research
Authors: Rutherford Brian A.
Published: February 2013

One reason for the disdain in which classical financial accounting research has come to held by many in the scholarly community is its allegedly insufficiently scientific nature. While many have defended classical research or provided critiques of post‐classical paradigms, the motivation for this paper is different. It offers an epistemologically robust underpinning for the approaches and methods of classical financial accounting research that restores its claim to legitimacy as a rigorous, systematic and empirically grounded means of acquiring knowledge. This underpinning is derived from classical philosophical pragmatism and, principally, from the writings of John Dewey. The objective is to show that classical approaches are capable of yielding serviceable, theoretically based solutions to problems in accounting practice.
The Cost of Carbon: Capital Market Effects of the Proposed Emission Trading Scheme (ETS)
Authors: Chapple Larelle , Clarkson Peter M. , Gold Daniel L.
Published: February 2013

In March 2008, the Australian Government announced its intention to introduce a national Emissions Trading Scheme (ETS), now expected to start in 2015. This impending development provides an ideal setting to investigate the impact an ETS in Australia will have on the market valuation of Australian Securities Exchange (ASX) firms. This is the first empirical study into the pricing effects of the ETS in Australia. Primarily, we hypothesize that firm value will be negatively related to a firm's carbon intensity profile. That is, there will be a greater impact on firm value for high carbon emitters in the period prior (2007) to the introduction of the ETS, whether for reasons relating to the existence of unbooked liabilities associated with future compliance and/or abatement costs, or for reasons relating to reduced future earnings. Using a sample of 58 Australian listed firms (constrained by the current availability of emissions data) which comprise larger, more profitable and less risky listed Australian firms, we first undertake an event study focusing on five distinct information events argued to impact the probability of the proposed ETS being enacted. Here, we find direct evidence that the capital market is indeed pricing the proposed ETS. Second, using a modified version of the Ohlson () valuation model, we undertake a valuation analysis designed not only to complement the event study results, but more importantly to provide insights into the capital market's assessment of the magnitude of the economic impact of the proposed ETS as reflected in market capitalization. Here, our results show that the market assesses the most carbon intensive sample firms a market value decrement relative to other sample firms of between 7% and 10% of market capitalization. Further, based on the carbon emission profile of the sample firms we imply a ‘future carbon permit price’ of between AUD$17 per tonne and AUD$26 per tonne of carbon dioxide emitted. This study is more precise than industry reports, which set a carbon price of between AUD$15 to AUD$74 per tonne.
The impact of acute tryptophan depletion on attentional performance in adult patients with ADHD
Authors: Mette C. , Zimmermann M. , Grabemann M. , Abdel‐Hamid M. , Uekermann J. , Biskup C. S. , Wiltfang J. , Zepf F. D. , Kis B.
Published: February 2013

Objective

To date, the impact of the neurotransmitter serotonin (5‐HT) on different neuropsychological functions in adults with attention deficit hyperactivity disorder (ADHD) is underinvestigated. We aimed to examine the effects of acute tryptophan depletion (ATD) and the resulting reduction in central nervous 5‐HT synthesis on target/non‐target discrimination ability and sustained attention in adults with ADHD using an AX‐Continuous Performance Test (AX‐CPT).

Method

Twenty male patients with ADHD (age: M = 30.25 SD = 9.37) and twenty male healthy controls (age: M = 27.90 SD = 6.01) received ATD on one day and a tryptophan‐balanced control condition (BAL) on another day in a double‐blind within‐subject crossover design. A continuous performance test (AX‐CPT) with three conditions (AX, AY, and BX) was administered on both days under depleted and sham‐depleted conditions.

Results

In patients omissions increased after ATD when compared with BAL. Patient's reaction time decreased after ATD when compared with BAL, which was contrasted by opposite effects in controls. Patients showed fewer correct responses (AX condition) and showed a higher rate of errors (condition AXE) independent of ATD or BAL intake.

Conclusion

The present preliminary results are indicative of the contribution of serotonergic neurotransmission to attentional processes in adults with ADHD.
Toll‐like receptors in Neonatal Sepsis
Authors: O’Hare Fiona M , William Watson R , Molloy Eleanor J
Published: February 2013

Toll‐like receptors are vital transmembrane receptors that initiate the innate immune response to many micro‐organisms. The discovery of these receptors has improved our understanding of host–pathogen interactions, and these receptors play an important role in the pathogenesis of multiple neonatal conditions such as sepsis and brain injury. Toll‐like receptors, especially TLRs 2 and 4, are associated with necrotizing enterocolitis, periventricular leukomalacia and sepsis.

Conclusion

Toll‐like receptor modulation may potentially be used as immunomodulators in the management of neonatal sepsis.
Mark‐Specific Hazard Ratio Model with Multivariate Continuous Marks: An Application to Vaccine Efficacy
Authors: Juraska M. , Gilbert P. B.
Published: February 2013

In randomized placebo‐controlled preventive HIV vaccine efficacy trials, an objective is to evaluate the relationship between vaccine efficacy to prevent infection and genetic distances of the exposing HIV strains to the multiple HIV sequences included in the vaccine construct, where the set of genetic distances is considered as the continuous multivariate “mark” observed in infected subjects only. This research develops a multivariate mark‐specific hazard ratio model in the competing risks failure time analysis framework for the assessment of mark‐specific vaccine efficacy. It allows improved efficiency of estimation by employing the semiparametric method of maximum profile likelihood estimation in the vaccine‐to‐placebo mark density ratio model. The model also enables the use of a more efficient estimation method for the overall log hazard ratio in the Cox model. In addition, we propose testing procedures to evaluate two relevant hypotheses concerning mark‐specific vaccine efficacy. The asymptotic properties and finite‐sample performance of the inferential procedures are investigated. Finally, we apply the proposed methods to data collected in the Thai RV144 HIV vaccine efficacy trial.
Till‐forming processes beneath parts of the Cordilleran Ice Sheet, British Columbia, Canada: macroscale and microscale evidence and a new statistical technique for analysing microstructure data
Authors: Neudorf Christina M. , Brennand Tracy A. , Lian Olav B.
Published: February 2013

This paper presents the first integrated macroscale and microscale examination of subglacial till associated with the last‐glacial (Fraser Glaciation) Cordilleran Ice Sheet (CIS). A new statistical approach to quantifying till micromorphology (multivariate hierarchical cluster analysis for compositional data) is also described and implemented. Till macrostructures, macrofabrics and microstructures support previous assertions that primary till in this region formed through a combination of lodgement and deformation processes in a temperate subglacial environment. Macroscale observations suggest that subglacial environments below the CIS were probably influenced by topography, whereby poor drainage of the substrate in topographically constricted areas, or on slopes adverse to the ice‐flow direction at glacial maximum, facilitated ductile deformation of the glacier bed. Microscale observations suggest that subglacial till below the CIS experienced both ductile and brittle deformation, including grain rotation and squeeze flow of sediment between grains under moist conditions, and microshearing, grain stacking and grain fracturing under well‐drained conditions. Macroscale observations suggest that ductile deformation events were probably followed by brittle deformation events as the substrate subsequently drained. The prevalence of ductile‐type microstructures in most till exposures investigated in this study suggests that ductile deformation signatures can be preserved at the microscale after brittle deformation events that result in larger‐scale fractures and shear structures. It is likely that microscale ductile deformation can also occur within distributed shear zones during lodgement processes. Cluster analysis of microstructure data and qualitative observations made from thin sections suggest that the relative frequency of countable microstructures in this till is influenced by topography in relation to ice‐flow direction (bed drainage conditions) as well as by the frequency and distribution of voids in the till matrix and skeletal grain shapes.
Changes in screening behaviors and attitudes toward screening from pre‐test genetic counseling to post‐disclosure in Lynch syndrome families
Authors: Burton‐Chase AM , Hovick SR , Peterson SK , Marani SK , Vernon SW , Amos CI , Frazier ML , Lynch PM , Gritz ER
Published: February 2013

The purpose of this study was to examine colonoscopy adherence and attitudes toward colorectal cancer (CRC) screening in individuals who underwent Lynch syndrome genetic counseling and testing. We evaluated changes in colonoscopy adherence and CRC screening attitudes in 78 cancer‐unaffected relatives of Lynch syndrome mutation carriers before pre‐test genetic counseling (baseline) and at 6 and 12 months post‐disclosure of test results (52 mutation negative and 26 mutation positive). While both groups were similar at baseline, at 12 months post‐disclosure, a greater number of mutation‐positive individuals had had a colonoscopy compared with mutation‐negative individuals. From baseline to 12 months post‐disclosure, the mutation‐positive group demonstrated an increase in mean scores on measures of colonoscopy commitment, self‐efficacy, and perceived benefits of CRC screening, and a decrease in mean scores for perceived barriers to CRC screening. Mean scores on colonoscopy commitment decreased from baseline to 6 months in the mutation‐negative group. To conclude, adherence to risk‐appropriate guidelines for CRC surveillance improved after genetic counseling and testing for Lynch syndrome. Mutation‐positive individuals reported increasingly positive attitudes toward CRC screening after receiving genetic test results, potentially reinforcing longer term colonoscopy adherence.
The Changing Landscape of the Canadian Food Market: Ethnicity and the Market for Ethnic Food
Authors: Cranfield John
Published: February 2013

This paper explores the interplay between immigration, ethnic diversity, and food demand in Canada. Attention focuses on the consequences of an increasingly diverse population on demand for food. The notion of dietary acculturation is discussed in the context of a fragmenting market for foods in Canada. A research agenda is presented with the intent to stimulate research that addresses the role of ethnicity in shaping demand for food in Canada. As Canada becomes more ethnically diverse, the landscape of the Canadian food environment will evolve. Understanding the impact of such change on demand for foods in Canada will become increasingly important. Such understanding can help inform the supply side of the market in terms of retail and food service location decisions, as well as decisions related to the marketing mix.

Dans le présent article nous analysons l’interaction entre l’immigration, la diversité ethnique et la demande alimentaire au Canada et examinons tout particulièrement les répercussions de l’accroissement de la diversité ethnique sur la demande alimentaire. Nous abordons la notion d’acculturation alimentaire dans un contexte de segmentation du marché alimentaire au Canada. Nous présentons un programme de recherche qui vise à stimuler la recherche sur le rôle de l’ethnicité dans la détermination de la demande alimentaire au Canada. Plus la population canadienne se diversifiera sur le plan ethnique, plus l’environnement alimentaire évoluera, d’où l’importance de bien déterminer les répercussions de cette diversification sur la demande alimentaire au Canada. La détermination de ces répercussions aidera les acteurs du côté de l’offre à prendre des décisions quant à l’emplacement des magasins d’alimentation et des établissements de restauration et à la logistique commerciale (marketing mix).
A comparison of supermatrix and supertree methods for multilocus phylogenetics using organismal datasets
Authors: Janies Daniel A. , Studer Jonathon , Handelman Samuel K. , Linchangco Gregorio
Published: February 2013

It has been proposed that supertree approaches should be applied to large multilocus datasets to achieve computational tractability. Large datasets such as those derived from phylogenomics studies can be broken into many locus‐specific tree searches and the resulting trees can be stitched together via a supertree method. Using simulated data, workers have reported that they can rapidly construct a supertree that is comparable to the results of heuristic tree search on the entire dataset. To test this assertion with organismal data, we compare tree length under the parsimony criterion and computational time for 20 multilocus datasets using supertree (SuperFine and SuperTriplets) and supermatrix (heuristic search in TNT) approaches. Tree length and computational times were compared among methods using the Wilcoxon matched‐pairs signed rank test. Supermatrix searches produced significantly shorter trees than either supertree approach (SuperFine or SuperTriplets; P < 0.0002 in both cases). Moreover, the processing time of supermatrix search was significantly lower than SuperFine+locus‐specific search (P < 0.01) but roughly equivalent to that of SuperTriplets+locus‐specific search (P > 0.4, not significant). In conclusion, we show by using real rather than simulated data that there is no basis, either in time tractability or in tree length, for use of supertrees over heuristic tree search using a supermatrix for phylogenomics.
Dose‐dependent effect of radiation on titanium implants: a quantitative study in rabbits
Authors: Li Jun Yuan , Pow Edmond Ho Nang , Zheng Li Wu , Ma Li , Kwong Dora Lai Wan , Cheung Lim Kwong
Published: February 2013

Objectives

The aim of the study was to investigate the dose‐dependent effect of radiation on dental implant stability and osseointegration using a series of quantitative analyses.

Material and methods

Six rabbits were randomly assigned to 15 and 30 Gy radiation groups. Each rabbit received radiation at the tibial and femoral metaphyseal region of left hind leg. The right leg was used as control. Implant surgery was performed on tibial and femoral metaphyses after 1 week. Totally 24 implants were inserted. The animals were killed at postoperative week four. Implant stability was measured using resonance frequency analysis. Ratio of bone volume to total volume (BV/TV), rate of bone growth, and bone‐to‐implant contact (BIC) were assessed using micro‐computed tomography (micro‐CT), fluorochrome labeling analysis, and histomorphometric analysis, respectively.

Results

After 4 weeks of healing, all implants were integrated (n = 6). Implant stability was significantly compromised by 15 Gy (P = 0.010) and 30 Gy (P = 0.025) of radiation. Radiation decreased BV/TV, and the significant effect was detected at the dose of 15 Gy (P = 0.008) and 30 Gy (P < 0.001). Bone growth in osseointegration was impaired by radiation. In 15 Gy group, the radiation side showed significant lower rate of bone growth than the control side at week 3 (P = 0.001), while the undistinguishable signals on 30 Gy radiation side suggested the low rate of new bone formation at each time point. Histomorphological BIC had no significant difference between 15 Gy control side and 15 Gy radiation side. 30 Gy radiation side showed a significantly lower BIC than 30 Gy control side (P < 0.001) as well as 15 Gy radiation side (P < 0.001).

Conclusions

Implant stability and osseointegration were compromised by radiation. Radiation compromised osseointegration in a dose‐dependent manner.
A robust approach for determination of the macro‐porous volume fraction of soils with X‐ray computed tomography and an image processing protocol
Authors: Keyes S. D. , Boardman R. P. , Marchant A. , Roose T. , Sinclair I.
Published: February 2013

Soil structure is known to govern aspects of hydration, aeration, faunal activity and root growth, which influence plant development. Industrial X‐ray computed tomography (μCT) has been used for over 15 years for the elucidation of soil structure, leading to a number of valuable insights. However, there is evidence of a need for more robust, repeatable methods for segmentation of significant structural features, which are essentially free from operator interference. We develop in this paper an automatable approach using a seeded region growth (SRG) algorithm for segmentation of the connected, macroporous domain of homogenized, real soils. Furthermore, we demonstrate methods for user‐independent selection of seed point and tolerance values, leading to a fully automated segmentation regime. The stability of this approach to different seed locations has been assessed, as well as the impact of X‐ray target and filter choice upon mitigation of artifacts, which are particularly detrimental to accuracy of SRG methods. Estimated porosity derived using this method has been compared with values from a gravimetric protocol and histogram thresholding approaches. It is seen that substantial differences exist in porosity quantified by such methods, with these differences probably the result of varying categorization of different porosity domains.
On the dimensionality of ecological stability
Authors: Donohue Ian , Petchey Owen L. , Montoya José M. , Jackson Andrew L. , McNally Luke , Viana Mafalda , Healy Kevin , Lurgi Miguel , O'Connor Nessa E. , Emmerson Mark C.
Published: February 2013

Ecological stability is touted as a complex and multifaceted concept, including components such as variability, resistance, resilience, persistence and robustness. Even though a complete appreciation of the effects of perturbations on ecosystems requires the simultaneous measurement of these multiple components of stability, most ecological research has focused on one or a few of those components analysed in isolation. Here, we present a new view of ecological stability that recognises explicitly the non‐independence of components of stability. This provides an approach for simplifying the concept of stability. We illustrate the concept and approach using results from a field experiment, and show that the effective dimensionality of ecological stability is considerably lower than if the various components of stability were unrelated. However, strong perturbations can modify, and even decouple, relationships among individual components of stability. Thus, perturbations not only increase the dimensionality of stability but they can also alter the relationships among components of stability in different ways. Studies that focus on single forms of stability in isolation therefore risk underestimating significantly the potential of perturbations to destabilise ecosystems. In contrast, application of the multidimensional stability framework that we propose gives a far richer understanding of how communities respond to perturbations.
Transient kinetic studies reveal isomerization steps along the kinetic pathway of Thermus thermophilus 3‐isopropylmalate dehydrogenase
Authors: Gráczer Éva , Lionne Corinne , Závodszky Péter , Chaloin Laurent , Vas Mária
Published: February 2013

To identify the rate‐limiting step(s) of the 3‐isopropylmalate dehydrogenase‐catalysed reaction, time courses of NADH production were followed by stopped flow (SF) and quenched flow (QF). The steady state kcat and Km values did not vary between enzyme concentrations of 0.1 and 20 μm. A burst phase of NADH formation was shown by QF, indicating that the rate‐limiting step occurs after the redox step. The kinetics of protein conformational change(s) induced by the complex of 3‐isopropylmalate with Mg2+ were followed by using the fluorescence resonance energy transfer signal between protein tryptophan(s) and the bound NADH. A reaction scheme was proposed by incorporating the rate constant of a fast protein conformational change (possibly domain closure) derived from the separately recorded time‐dependent formation of the fluorescence resonance energy transfer signal. The rate‐limiting step seems to be another slower conformational change (domain opening) that allows product release.
Evaluation of push‐out bond strength of four luting agents and SEM observation of the dentine/fibreglass bond interface
Authors: Pereira J. R. , Valle A. L. , Ghizoni J. S. , Só M. V. R. , Ramos M. B. , Lorenzoni F. C.
Published: February 2013

Aim

To assess the dentine/fibreglass‐bonded interface by scanning electron microscopy and the push‐out bond strength of four luting cements.

Methodology

Forty root‐filled human canines, with similar root lengths, were restored with fibreglass posts and randomly divided into four groups according to the cements employed (CG Gold Label I, RelyX ARC, BisCem and RelyX U100). After standardized post‐space preparation, the root dentine was pre‐treated for dual‐polymerizing resin cements and untreated for the other cements. The mixed luting cement paste was inserted into root canals with a spiral filler and applied to the post‐surface that was seated into the root canal. After 7 days, the teeth were sectioned perpendicular to their long axis into 1‐mm‐thick sections and submitted to a push‐out test (1 mm min−1). Statistical analyses were carried out by two‐way anova and Tukey's tests (P < 0.05).

Results

The bond strength was significantly affected by the type of cement (P < 0.001) and by the longitudinal region of the root canal (P < 0.031). All cements exhibited gaps at the dentine/cement interface.

Conclusions

The self‐adhesive materials and the glass ionomer cements had the highest push‐out bond strength values when compared with the dual‐curing resin cement.
Relational and institutional embeddedness of Web‐enabled entrepreneurial networks: case studies of netrepreneurs in China
Authors: Avgerou Chrisanthi , Li Boyi
Published: February 2013

Drawing from a multidisciplinary literature, we form a theoretical perspective of the social embeddedness of economic activity as interpersonal ties that are formed in relation to the institutions of an economy. From this perspective, we then seek to explain the emergence of networks of micro‐entrepreneurs that conduct their business on the Taobao Web platform in China, and we derive theoretical propositions about the social embeddedness of Web platform‐based economic activity. Two case studies of such networks show how Web platform tools and services create conditions of possibility for developing online business by micro‐entrepreneurs and for overcoming cultural reluctance of economic exchange with strangers. Our research suggests that economic activity on Web platforms is embedded in a mix of virtual and community‐based relations that are shaped by and alter the behavioural norms of a local culture. It also points to the government and the corporate Web platform service provider as important organisational actors enabling the creation of entrepreneurial networks.
Conservation of freshwater habitats and fishes in the Western Ghats of India
Authors: Kumar R. , Devi K. R.
Published: February 2013

The Western Ghats, India, present a series of challenges and opportunities for novel approaches to conservation. Running parallel to the coast of the Indian Peninsula, the Ghats represent the western edge of the Deccan Plateau and traverse 1400 km over six states, giving rise to rivers that drain over a third of the country. A global biodiversity hotspot with varied topography housing diverse ecological niches, the Western Ghats present significant challenges to, and opportunities for, conservation. Dense human habitation near river systems and dependence on freshwater resources for livelihoods make it difficult to establish protected areas. Freshwater fishes in this region account for c. 40% of the freshwater fishes in India and around 189 species are endemic to the Western Ghats. All the usual threats to the fishes and their habitats are present, and the freshwater fishes of the Western Ghats are of great social and economic importance to the local community. Zoos, aquariums and the general public can play a role in conservation efforts through education and research. Utilizing traditional customs already in place, such as water bodies in the vicinity of temples where no fishing occurs, in conjunction with ecotourism and more modern technologies, such as live gene banks and cryopreservation, may ease the burden on the freshwater habitats and fishes in the region.
Feeling left out? The mediating role of perceived rejection on workgroup mistreatment and affective, behavioral, and organizational outcomes and the moderating role of organizational norms
Authors: Penhaligon Nikki L. , Louis Winnifred R. , Restubog Simon Lloyd David
Published: February 2013

This two‐study paper examines the detrimental impact of workgroup mistreatment and the mediating role of perceived rejection. In Study 1, perceived rejection emerged as a mediator between workgroup mistreatment and depression, organization‐based self‐esteem, organizational deviance, and organizational citizenship behaviors. In Study 2, the role of organizational norms was examined. Employees who experienced supportive organizational norms reported lower levels of perceived rejection, depression and turnover intentions, and higher levels of organization‐based self‐esteem and job satisfaction. Employees in the supportive norms condition reported that they were more likely to seek reconciliation after experiencing mistreatment than those who experienced low support. Perceived rejection also emerged as a mediator. Results, practical implications, and future research directions are discussed.
Investigation of nonverbal discrimination against women in simulated initial job interviews
Authors: Hess Kathleen P.
Published: February 2013

This study investigated nonverbal sex discrimination in simulated initial job interviews with women applicants. It was hypothesized that experienced interviewers would exhibit more negative behaviors while interviewing a woman for a “masculine” job (an incongruent interview), but more positive behaviors while interviewing a woman for a “feminine” job (a congruent interview). It was further hypothesized that the behavior of inexperienced interviewers would remain the same across interviews. Mock initial job interviews were videotaped and nonverbal behaviors were coded. As hypothesized, experienced interviewers exhibited more negative and fewer positive behaviors in the incongruent interviews, whereas inexperienced interviewers did not. Unexpectedly, inexperienced interviewers exhibited more positive and fewer negative behaviors during incongruent interviews. Implications for training to reduce nonverbal discrimination are discussed.
The effects of hatching date on timing of autumn migration in partial migrants – an individual approach
Authors: Meller Kalle , Lehikoinen Aleksi , Vähätalo Anssi V.
Published: February 2013

Timing of spring migration and breeding and their interaction with climate change has been widely studied in recent years, but the possible changes in timing of autumn migration have gained less attention. This work focuses on autumn migration and provides the first multi‐species individual‐based study of how hatching date affects the autumn migration date and migration age by using nestling ring data and re‐trappings of the same individuals during the autumn migration at the Hanko Bird Observatory, Finland. We studied three potentially multibrooded passerines (great tit, blue tit and coal tit) and two single‐brooded birds of prey (goshawk, sparrowhawk), all partially migratory short‐distance migrants. Individuals from late broods migrated at a younger age in all tit species and also in hawks the late hatched individuals tended to migrate at a younger age than the early‐hatched individuals. Late‐hatched individuals migrated later than early‐hatched individuals in blue and coal tits, where the latest hatchers represented second brood individuals. Based on our results, the time from hatching to autumn migration is not constant even among individuals of the same population. Our study indicates that climate warming induced advancement of avian breeding may cause changes in the timing of autumn migration through the frequency of second broods.
Gene‐flow across the European crow hybrid zone – a spatial simulation
Authors: Brodin Anders , Haas Fredrik , Hansson Bengt
Published: February 2013

In hybrid zones populations that are otherwise allopatric meet and produce hybrids. One of the most well‐known hybrid zones occurs throughout much of Europe between the hooded and carrion crows. Even though these species (or subspecies) of crows look very different, genetic differentiation is weak, and introgression seems to be common. In a spatial simulation that was based on empirically estimated values, we investigated how introgressing alleles that would confer some fitness advantage would flow across the zone. The advantage was assumed to be some unknown factor that enhanced survival for carriers relative to non‐carriers. We varied the yearly survival advantage between 0 to 10% and recorded how this would affect zone shape and position. In the simulation we cycled ‘yearly’ events such as reproduction, mortality and juvenile dispersal. We started the simulation by equipping all individuals of one crow type outside the zone with a homozygotic set of the beneficial allele. At all levels of advantage the allele first rapidly became fixed in the donator crow type, then transgressed into the receiving type more slowly and finally became fixed in all individuals. The time until fixation varied from around 176 yr for a 10% advantage to around 20 000 yr for 0% advantage. An exciting discovery was that the position of the zone would move during the introgression but then stop. The reason is that the beneficial allele would be common in the donating type but not in the receiving type during the introgression event. At large the crow hybrid zone appears to have been stable for a long time but there have been small recent northward movements of carrion crows in both Scotland and Denmark. We suggest that introgression by itself is a factor that should be considered as an explanation for why hybrid zones move temporarily.
Death in Our Life
Authors: Raz Joseph
Published: February 2013

This paper examines a central aspect of the relations between duration and quality of life by considering the moral right to voluntary euthanasia, and some aspects of the moral case for a legal right to euthanasia. Would widespread acceptance of a right to voluntary euthanasia lead to widespread changes in attitudes to life and death? Many of its advocates deny that, seeing it as a narrow right enabling people to avoid ending their life in great pain or total dependence, or a vegetative state. I argue that the right cannot cogently be conceived as a narrow right, confined to very limited circumstances. It is based on the value of having the normative power to choose the time and manner of one's death. Its recognition will be accompanied by far reaching changes in culture and attitudes, and these changes will enrich people's life by enabling them to integrate their death as part of their lives.
Spatial extent, regional specificity and metacommunity structuring in lake macrophytes
Authors: Alahuhta Janne , Heino Jani
Published: February 2013

Aim

Spatial extent is inherently related to the potential roles of the main mechanisms structuring metacommunities. We examined the effects of varying spatial extent (ecological province, region and subregion) on the environmental and spatial components of variation in lake macrophyte communities. We also studied these effects separately for three macrophyte functional groups.

Location

The US state of Minnesota.

Methods

We examined average and heterogeneity differences in macrophyte community composition and environmental variation among the subregions of Minnesota using canonical analysis of principal coordinates (CAP) and homogeneity of multivariate dispersion (PERMDISP), respectively. We further used partial redundancy analysis (pRDA) to decompose variation in macrophyte community composition between environmental variables and spatial location at each spatial extent and geographical region. Spatial variables were derived using principal coordinates of neighbour matrices (PCNM) analysis.

Results

CAP and PERMDISP analyses showed that the subregions differed both in average community composition and in the heterogeneity of community composition for all macrophyte taxa, for emergent and submerged macrophytes, but not for non‐rooted macrophytes. We did not, however, find significant differences in overall environmental heterogeneity among the subregions. Variation partitioning using pRDAs showed that species sorting is more important than spatial processes for macrophytes, although these patterns were relatively weak. There was, however, much regional specificity, with the environmental and spatial fractions of community composition varying widely at different spatial extents, among different geographical regions and among functional groups. Contrary to our initial expectations, we did not find increasing spatial structuring and decreasing environmental control with increasing spatial extent.

Main conclusions

Our findings indicate that, in macrophyte metacommunities, the relative contribution of spatial processes and environmental control varies rather unpredictably with spatial extent and geographical region. Our findings are thus of importance in advancing metacommunity ecology by showing that drawing wide‐ranging conclusions based on a single spatial extent or a single geographical region may be unwise.