1,211 research outputs found
Long-term management practices successfully reduce bird-related electrical faults in a transmission grid increasingly used by white storks for nesting
Bird nests on transmission lines can cause electrical faults which reduce service reliability. To address this
problem, since the mid-90s, the Portuguese Transmission System Operator (TSO) has undertaken management
actions to discourage white storks Ciconia ciconia from nesting in hazardous locations of the pylons. Here, we
compiled and analyzed an 18-year series of data on electrical faults, TSO management actions to tackle these,
and stork nests on transmission pylons in Portugal to: (a) determine the relative importance of bird-related faults
over the total number of faults; (b) describe variations in bird-related faults across time (season of the year and
time of the day); (c) describe spatial variations in bird-related faults and their association with the occurrence of
white stork nests on pylons; and (d) analyze the trends, over the years, of the number of white stork nests on
pylons, the TSO management actions and their effectiveness in reducing bird-related fault rates. Overall, birds
accounted, on average, for 25.3% of the electrical faults in the transmission network, with the vast majority
being attributed to white storks. The seasonal pattern of bird-related faults showed higher rates in April and in
October–November. Faults occurred more often during the night period, when storks spend more time on the
pylons. We found a positive spatial relationship between the electrical fault rate and the proportion of pylons
with stork nests (and the correlated number of nests per 100 km of line). There was, however, considerable
variation in the fault rates not explained by the stork nest variables, particularly during the non-breeding season.
The TSO management actions (namely removal/translocation of nests in hazardous locations of the pylons,
installation of anti-perching devices and provision of alternative nesting platforms) significantly reduced, as a
whole, the annual number of bird-related faults between 2001 and 2018, despite the three-fold increase in the
number of white stork nests on transmission pylons. A deeper understanding of how white storks use the
transmission pylons outside the breeding season is needed, so that targeted management actions can be taken to
reduce the remaining bird-related fault rates to residual levels.info:eu-repo/semantics/publishedVersio
Project-Based Learning and its Effects on Freshmen Social Skills in an Engineering Program
This chapter reports some effects of project-based learning (PBL) on development of social skills on Industrial Engineering freshmen (first-year) students. PBL is an active learning and student-centered methodology that promotes skills development such as the 4C—Critical thinking, Communication, Collaboration and Creativity. These skills should be an integral part of the expected engineering competences needed for professional proficiency, in order to comply with a changeable world and instable marketplaces, which require competences well beyond the technical ones. Through a survey to the first-year students and interviews to recently graduated professionals, some interesting results about the effects of PBL on social skills development were acquired. Some of these results relate to the recognition of acquiring competences during the project development and the usefulness and applicability of these in their daily professional activity. Among others, these encompass the capability to lead projects and produce effective work within multidisciplinary teams, to deal with conflicts, and to provide effective oral and written communication and capability to adapt to different work environments and assuming responsibilities, reflecting and assessing the own learning and the work of others, and to respect the attitudes and work of others
Evolution of collective action in adaptive social structures
Many problems in nature can be conveniently framed as a problem of evolution of collective cooperative behaviour, often modelled resorting to the tools of evolutionary game theory in well-mixed populations, combined with an appropriate N-person dilemma. Yet, the well-mixed assumption fails to describe the population dynamics whenever individuals have a say in deciding which groups they will participate. Here we propose a simple model in which dynamical group formation is described as a result of a topological evolution of a social network of interactions. We show analytically how evolutionary dynamics under public goods games in finite adaptive networks can be effectively transformed into a N-Person dilemma involving both coordination and co-existence. Such dynamics would be impossible to foresee from more conventional 2-person interactions as well as from descriptions based on infinite, well-mixed populations. Finally, we show how stochastic effects help rendering cooperation viable, promoting polymorphic configurations in which cooperators prevail.This research was supported by FCT-Portugal through grants PTDC/FIS/101248/2008 and PTDC/MAT/122897/2010, by multi-annual funding of CMAF-UL and INESC-ID (under the project PEst-OE/EEI/LA0021/2011) provided by FCT-Portugal. Partial Financial support by the National Science Foundation under Grant No. NSF PHY11-25915 is also gratefully acknowledged
Response of vertebrate scavengers to power line and road rights-of-way and its implications for bird fatality estimates
Linear infrastructures, such as power lines and roads, are an important source of bird mortality.
However, little is known on the potential effect of these infrastructures on local scavenger guilds, their
foraging activity and the resulting bird carcass removal patterns. This is an important source of bias in
studies aiming to quantify bird fatalities due to linear infrastructures. We used camera-traps to record
scavenger identity and persistence patterns of bird carcasses placed close to linear infrastructure
and nearby controls in two Mediterranean agricultural regions. We found that linear infrastructure
influence on scavenger identity varied depending on the region. Contrary to expectations, linear
infrastructure presence had either none or a positive effect on carcass persistence, meaning that
carcasses placed within power line or road rights-of-way were not removed faster than the ones
placed in controls. We conclude that linear infrastructure effect on vertebrate scavenging patterns is
likely to be region-specific, and that reliable correction factors for carcass removal-bias in bird fatality
estimates require site-specific experiments to characterize local scavenging processesinfo:eu-repo/semantics/publishedVersio
Hyperfine magnetic field in ferromagnetic graphite
Information on atomic-scale features is required for a better understanding
of the mechanisms leading to magnetism in non-metallic, carbon-based materials.
This work reports a direct evaluation of the hyperfine magnetic field produced
at 13C nuclei in ferromagnetic graphite by nuclear magnetic resonance (NMR).
The experimental investigation was made possible by the results of
first-principles calculations carried out in model systems, including graphene
sheets with atomic vacancies and graphite nanoribbons with edge sites partially
passivated by oxygen. A similar range of maximum hyperfine magnetic field
values (18-21T) was found for all systems, setting the frequency span to be
investigated in the NMR experiments; accordingly, a significant 13C NMR signal
was detected close to this range without any external applied magnetic field in
ferromagnetic graphite
A legal framework for an elderly healthcare platform: A privacy and data protection overview
[EN] Cognitive problems are increasingly affecting the population, with the elderly being the ones most affected. This problem requires a new approach in terms of medical and social actions, personalisation, and services. The Ambient Assisted Living area provides solutions to allow elderly people to stay in their homes safely and with the appropriate care. The number of Ambient Assisted Living projects is increasing rapidly, leading to large commercial deployment, and most of these projects disregard the privacy and data protection of the users and the information that they process and save. The iGenda project is a Cognitive Assistant inserted in the Ambient Assisted Living area that provides help to users in their daily lives. However, since it requires the transfer of a large amount of private and personal data between the modules of the platform, fundamental rights may be at stake. This paper presents the iGenda platform, the principle rights of data protection and transmission, legal guarantees and latent ethical concerns. Furthermore, the dichotomy between current developments and legal and ethical aspects are explained. To overcome this problem, legal considerations and ethical considerations are presented, embracing appropriate solutions to features that present any threat. (C) 2017 Angelo Costa, Aliaksandra Yelshyna, Teresa C. Moreira, Francisco C.P. Andrade, Vicente Julian, Paulo Novais. Published by Elsevier Ltd. All rights reserved.This work has been supported by FCT - Fundacao para a Ciencia e Tecnologia within the Project Scope UID/CEC/00319/2013. A. Costa thanks the Fundacao para a Ciencia e a Tecnologia (FCT) Post-Doc scholarship with the Ref. SFRH/BPD/102696/2014. This work is also partially supported by the MINECO/FEDER TIN2012-36586-C03-01.Costa, A.; Yelshyna, A.; Moreira, TC.; Andrade, FC.; Julian Inglada, VJ.; Novais, P. (2017). A legal framework for an elderly healthcare platform: A privacy and data protection overview. Computer Law & Security Review. 33(5):647-658. https://doi.org/10.1016/j.clsr.2017.03.02164765833
Towards eco-efficient lean production systems
Abstract: Lean Production has proved itself a worthwhile production strategy in many distinct industries across all regions of the planet by achieving higher levels of production efficiency. Several authors identified that Lean inadvertently has had significant environmental gains. Such achievements are considered of special relevance in a global and highly competitive economy which is progressively both tied-up and driven by an environmental agenda. The main goal of the present study is to enlighten the contribution of Lean for achieving a better environmental performance of production systems and identify this as an emergent business model for supporting eco-efficiency
Prognostic value of the percentage of positive fragments in biopsies from patients with localized prostate cancer
OBJECTIVE: To assess the prognostic value of the percentage of positive fragments (PPF) in biopsies from patients with localized prostate cancer (PCa) undergoing radical prostatectomy. MATERIALS AND METHODS: During the period from March 1991 to November 2000, 440 patients were selected. Cases receiving neoadjuvant or adjuvant hormone therapy, or adjuvant radiotherapy, were excluded, as were cases presenting Gleason scores higher than 6 at biopsy. PPF was defined as the total number of fragments divided by the total number of biopsy fragments times 100. This variable was initially divided into categories from 0 to 25%, 25.1% to 50%, 50.1 to 75% and 75% to 100%. During the postoperative period, patients were assessed every 2 months for 1 year, then every 6 months for 5 years, and then yearly. Biochemical recurrence was defined as serum PSA higher than or equal to 0.4 ng/mL. Median follow-up was 60 months. RESULTS: One hundred and nine (24.8%) of the 440 patients under study had biochemical recurrence. In the univariate analysis, PPF significantly influenced disease-free survival (log-rank, p < 0.001), and patients with PPF between 75 and 100% presented a risk of a biochemical recurrence of the disease 3 times higher than patients with PPF between 0 and 25% (p < 0.001). After the Cox regression analysis, both serum PSA (p = 0.001) and PPF (p < 0.001) showed to be independent predictive factors for disease-free survival following surgery. CONCLUSION: PPF measurement in biopsy is a simple and practical method, which should be routinely used as a predictive factor for biochemical recurrence in patients with PCa presenting Gleason scores between 2 and 6.Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Division of UrologyUNIFESP, EPM, Division of UrologySciEL
Wired: impacts of increasing power line use by a growing bird population
Power lines are increasingly widespread across many regions of the planet. Although these linear infrastructures are known for their negative impacts on bird populations, through collision and electrocution, some species take advantage of electricity pylons for nesting. In this case, estimation of the net impact of these infrastructures at the population level requires an assessment of trade-offs between positive and negative impacts. We compiled historical information (1958–2014) of the Portuguese white stork Ciconia ciconia population to analyze long-term changes in numbers, distribution range and use of nesting structures. White stork population size increased 660% up to 12000 breeding pairs between 1984 and 2014. In the same period, the proportion of nests on electricity pylons increased from 1% to 25%, likely facilitated by the 60% increase in the length of the very high tension power line grid (holding the majority of the nests) in the stork's distribution range. No differences in breeding success were registered for storks nesting on electricity pylons versus other structures, but a high risk of mortality by collision and electrocution with power lines was estimated. We discuss the implications of this behavioral change, and of the management responses by power line companies, both for stork populations and for managers
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