899 research outputs found
Estimation of Seed Bank and Seed Viability of the Gulf of Saint Lawrence Aster, Symphyotrichum laurentianum, (Fernald) Nesom
The Gulf of St. Lawrence Aster, Symphyotrichum laurentianum, is a member of the family Asteraceae and is listed as “threatened” by COSEWIC (Committee on the Status of Endangered Wildlife in Canada). This rare and vulnerable halophyte grows in only a few locations in New Brunswick, Prince Edward Island, and the Magdalen Islands, Quebec. As an annual, S. laurentianum relies exclusively on its seeds to survive to the next generation. The goal of this study was to estimate the quantity of viable S. laurentianum seeds in the persistent and transient seed banks at selected sites in Prince Edward Island. Overall, the number of seeds in the transient and persistent seed banks is low. The greatest concentration of seeds was found near the surface of the soil. In addition, only a small proportion of those seeds tested positive for viability based on Tetrazolium staining. Of the seeds in the persistent and transient seed banks combined, 53% were viable whereas only 2% of the seeds in the persistent seed bank were viable. Population surveys were also completed at the five known sites (both extinct and extant) in Prince Edward Island National Park. All sites showed signs of decline based on population estimates dating back to 1993. The Covehead Pond site showed the greatest decline: from 250-300 individuals in 1993 to only 10 individuals in 2002. The population at Dune Slack also showed a dramatic decrease from approximately 65 000 in 1999, to 2 200 individuals in 2002. Monitoring of this plant and the development of a management plan for the species are critical to its survival
Diversifying deep transitions:Accounting for socio-economic directionality
The paper sets out to enrich the emerging debate on ‘deep’, transversal transitions. It does so by drawing attention to socio-economic developments neglected in the Deep Transition (DT) framework of Kanger and Schot, such as marketization, labour contracts becoming more individual and precarious, and changing human beliefs, aspirations, needs and wants as important developments. The framework of Deep Transition is criticised for neglecting tensions and contestations about progress, the socio-economic order and distributional issues. This paper aims to complement ‘deep transitions’ research with insights about socio-economic transformation processes. These are shown to be conflict-ridden and full of tensions, creating pressures on socioeconomic orders and institutional logics. Because of this, development does not follow a neat pattern of convergence. In addition to identifying neglected issues and conceptual blind spots, the paper also outlines the scope for conceptual bridging between socio-technical and socio-economic transformation perspectives through attention to institutional logics and dialectics of change. We make a plea for a broader DT research agenda that covers relevant socio-economic rules, metaregimes and institutional contradictions. Attention to directionality helps to deal with three weaknesses of the DT framework: the assumption of convergence, materialism, and insufficient attention to the multitude of value orientations and logics
The magnetoelectrochemical switch
In the field of spintronics, the archetype solid-state two-terminal device is the spin valve, where the resistance is controlled by the magnetization configuration. We show here how this concept of spin-dependent switch can be extended to magnetic electrodes in solution, by magnetic control of their chemical environment. Appropriate nanoscale design allows a huge enhancement of the magnetic force field experienced by paramagnetic molecular species in solutions, which changes between repulsive and attractive on changing the electrodes' magnetic orientations. Specifically, the field gradient force created within a sub-100-nm-sized nanogap separating two magnetic electrodes can be reversed by changing the orientation of the electrodes' magnetization relative to the current flowing between the electrodes. This can result in a breaking or making of an electric nanocontact, with a change of resistance by a factor of up to 103. The results reveal how an external field can impact chemical equilibrium in the vicinity of nanoscale magnetic circuits
Classifying training drills based on movement demands in Australian Football
Time-motion data was used to classify a selection of training drills. Ten midfielders (age=23.8±1.8yr; height=183.9±3.8cm; mass=83.2±5.0 kg) from an Australian Football League team participated in 17 training drills and four quarters of an official competitive match. Heart rate and time-motion data were collected using Global Positioning and Heart Rate Systems. Cluster analysis of mean distance travelled in the seven velocity zones identified three clusters: 1) game-specific conditioning; 2) skill refining/moderate intensity dominant; and 3) skill refining/low intensity dominant. Differences between the three clusters in distance travelled at the speed zones were confirmed using one-way ANOVA. Differences between clusters were also assessed for number of efforts in velocity zones and percentage time in heart rate zones. When compared to drills with a focus on skill refining or performed on a reduced playing area, drills utilising the entire playing field better replicated the movement characteristics of competitive game play
City Labs as vehicles for innovation in urban planning processes
This paper assesses the role of urban experiments for local planning processes through a case-based analysis of the city lab of Maastricht. In conjunction with this, the article offers three contributions, as additional elements. Firstly, the paper develops a set of defining characteristics of city labs as an analytical concept which is relevant for discussions about (collaborative) planning. Secondly, it refines the literature on collaborative planning by drawing attention to experimentation and innovation. Thirdly, the paper assesses the potential of city labs to contribute to the innovation of urban governance. The work draws from the literature on experimentation and learning as well as the literature on collaborative urban planning. In the conclusions, we discuss the potential of city labs as vehicles for learning about new urban planning approaches and their limitations as spaces for small-scale experimentation. The paper is based on research for the URB@Exp research project funded by JPI Urban Europe
10341 Abstracts Collection -- Insider Threats: Strategies for Prevention, Mitigation, and Response
From August 22 to 26, 2010, the Dagstuhl Seminar 10341 ``Insider Threats: Strategies for Prevention, Mitigation, and Response\u27\u27 was held
in Schloss Dagstuhl~--~Leibniz Center for Informatics.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
Different metabolic responses during incremental exercise assessed by localized 31P MRS in sprint and endurance athletes and untrained individuals
Until recently, assessment of muscle metabolism was only possible by invasive sampling. 31P magnetic resonance spectroscopy ( 31P MRS) offers a way to study muscle metabolism non-invasively. The aim of the present study was to use spatially-resolved 31P MRS to assess the metabolism of the quadriceps muscle in sprint-trained, endurance-trained and untrained individuals during exercise and recovery. 5 sprint-trained (STA), 5 endurance-trained (ETA) and 7 untrained individuals (UTI) completed one unlocalized 31P MRS session to measure phosphocreatine (PCr) recovery, and a second session in which spatially-resolved 31P MR spectra were obtained. PCr recovery time constant (τ) was significantly longer in STA (50±17 s) and UTI (41±9 s) than in ETA (30±4 s), (P\u3c0.05). PCr changes during exercise differed between the groups, but were uniform across the different components of the quadriceps within each group. pH during recovery was higher for the ETA than for the UTI (P\u3c0.05) and also higher than for the STA (P\u3c0.01). Muscle volume was greater in STA than in UTI (P\u3c0.05) but not different from ETA. Dynamic 31P MRS revealed considerable differences among endurance and sprint athletes and untrained people. This non-invasive method offers a way to quantify differences between individual muscles and muscle components in athletes compared to untrained individuals. 2013 Georg Thieme Verlag KG Stuttgart.New York
A low-tech, cost-effective and efficient method for safeguarding genetic diversity by direct cryopreservation of poultry embryonic reproductive cells
Chickens are an important resource for smallholder farmers who raise locally adapted, genetically distinct breeds for eggs and meat. The development of efficient reproductive technologies to conserve and regenerate chicken breeds safeguards existing biodiversity and secures poultry genetic resources for climate resilience, biosecurity, and future food production. The majority of the over 1600 breeds of chicken are raised in low and lower to middle income countries under resource-limited, small-scale production systems, which necessitates a low-tech, cost-effective means of conserving diversity is needed. Here, we validate a simple biobanking technique using cryopreserved embryonic chicken gonads. The gonads are quickly isolated, visually sexed, pooled by sex, and cryopreserved. Subsequently, the stored material is thawed and dissociated before injection into sterile host chicken embryos. By using pooled GFP and RFP-labelled donor gonadal cells and Sire Dam Surrogate mating, we demonstrate that chicks deriving entirely from male and female donor germ cells are hatched. This technology will enable ongoing efforts to conserve chicken genetic diversity for both commercial and smallholder farmers, and to preserve existing genetic resources at poultry research facilities
Mental Well-Being in UK Higher Education During Covid-19: Do Students Trust Universities and the Government?
This paper draws upon the concept of recreancy to examine the mental well-being of university students during the Covid-19 pandemic. Briefly, recreancy is loss of societal trust that results when institutional actors can no longer be counted on to perform their responsibilities. Our study of mental well-being and recreancy focuses on the role of universities and government regulators within the education sector. We surveyed 600 UK students attending 161 different public higher education providers in October 2020 during a time when many UK students were isolated in their residences and engaged in online learning. We assessed student well-being using the Short Warwick-Edinburgh Mental Well-being Scale (scored 7–35) and found the mean score to be 19.9 [95% confidence interval (CI) 19.6, 20.2]. This level of well-being indicates that a significant proportion of UK students face low levels of mental well-being. Structural equation modeling (SEM) analysis indicates that high recreancy—measured as a low trust in universities and the government—is associated with low levels of mental well-being across the student sample. While these findings are suggestive, they are also important and we suggest that government and university leaders should not only work to increase food and housing security during the Covid-19 pandemic, but also consider how to combat various sector trends that might intensify recreancy
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