Visual recovery of desert pavement surfaces following impacts from vehicle and foot traffic in the Ross Sea region of Antarctica

Sites of past human activity were investigated to assess the visual recovery of the desert pavement following impacts from human trampling and vehicle traffic. Visually disturbed and nearby control sites were assessed using comparative photographic records, a field-based Visual Site Assessment, and Desert Pavement Recovery Assessment. Sites included: vehicle and walking tracks at Marble Point and Taylor Valley; a campsite, experimental treading trial site, and vehicle tracks in Wright Valley; and vehicle and walking tracks at Cape Roberts. The time since last disturbance ranged from three months to over 50 years. This investigation also attempted to determine what has the greatest lasting visual impact on soil surfaces in the Ross Sea region: dispersed trafficking or track formation? Walking tracks remained visible in the landscape (due to larger clasts concentrating along track margins) long after the desert pavement surface had recovered. However, randomly dispersed footprints were undetectable within five years. For many sites, allowing widespread trampling will give lower medium-term visible impact than concentrating traffic flow by track formation. For steep slopes and sites where repeated visits occur, use of a single track is recommended. Some 1950s vehicle tracks remain visible in the Antarctic landscape, but where visually obvious impacts were remediated, evidence of former occupation was almost undetectable

An assessment of contact and laser-based scanning of rock particles for railway ballast

Performance of traditional railway structure depends significantly on the behaviour of its support layers, particularly the ballast. This layer’s rock particles are selected to ensure high mechanical strength, but traffic and mechanical maintenance break and wear the particles. Consequently, the layer incurs permanent deformations that degrade its strength and increase deformability and permeability. Particle physical characteristics, in particular those related to size and shape, influence their fragmentation and wear and must be studied accordingly. In addition, structural numerical models that represent individual particles, such as the discrete element method, have been increasingly used to model the infrastructure and therefore detailed geometrical characterization in the form of 3D digital models of the particles are necessary. This work contributes to this goal by investigating a contact-based cost-effective method that digitizes particle form and allows the determination of their geometric parameters. This method is described, compared with well-established laser scanning technique and then applied to study degradation of particles in Los Angeles and microDeval fragmentation tests.info:eu-repo/semantics/publishedVersio

Management consulting business models a perspective of sustainability

In a world characterised by distorted information, Management Consulting is one of the fastest growing activities that has been questioned since its first appearance. Doubts have been floating around the limits of the industry, the role and utility of its practitioners and the consequent implicit value-added to the clients’ firms. As such the main objective of this research is to investigate the business models of consulting companies to understand the way they operate and how they contribute to attain a sustainable competitive advantage in the industries where they are present. This investigation was done by conducting interviews in 2015 and collecting personal testimonies through from top consultants of eight consulting firms. The findings suggest that all organisations that participated in the research possess a unique combination of interrelated mechanisms and approaches towards organisational structure, clients, consultants and projects, which indicates their concern to maintain and augment a sustained superior performance.info:eu-repo/semantics/acceptedVersio

Event-related potentials reveal early attention bias for negative, unexpected behavior

Numerous studies have documented that expectancy-violating (EV) behavior (i.e., behavior that violates existing person impressions) elicits more effortful cognitive processing compared to expectancy-consistent (EC) behavior. Some studies also have shown that this effect is modulated by the valence of behavior, though this finding is inconsistent with some extant models of expectancy processes. The current research investigated whether the valence of EV information affects very rapid attentional processes thought to tag goal-relevant information for more elaborative processing at later stages. Event-related brain potentials (ERPs) were recorded while participants read depictions of behavior that either were consistent with or violated established impressions about fictitious characters. Consistent with predictions, a very early attention-related ERP component, the frontal P2, differentiated negative from positive EV behavior but was unaffected by the valence of EC behavior. This effect occurred much earlier in processing than has been demonstrated in prior reports of EV effects on neural response, suggesting that impression formation goals tune attention to information that might signal the need to modify existing impressions.info:eu-repo/semantics/acceptedVersio

On Unitary Time Evolution in Gowdy T3T^3 Cosmologies

A non-perturbative canonical quantization of Gowdy $T^3$ polarized models carried out recently is considered. This approach profits from the equivalence between the symmetry reduced model and 2+1 gravity coupled to a massless real scalar field. The system is partially gauge fixed and a choice of internal time is performed, for which the true degrees of freedom of the model reduce to a massless free scalar field propagating on a 2-dimensional expanding torus. It is shown that the symplectic transformation that determines the classical dynamics cannot be unitarily implemented on the corresponding Hilbert space of quantum states. The implications of this result for both quantization of fields on curved manifolds and physically relevant questions regarding the initial singularity are discussed.Comment: 16 pages, no figures, latex file; references added, a proof included. Final version to appear in IJMP

Profiling DNA methylation based on next-generation sequencing approaches: New insights and clinical applications

DNA methylation is an epigenetic modification that plays a pivotal role in regulating gene expression and, consequently, influences a wide variety of biological processes and diseases. The advances in next-generation sequencing technologies allow for genome-wide profiling of methyl marks both at a single-nucleotide and at a single-cell resolution. These profiling approaches vary in many aspects, such as DNA input, resolution, coverage, and bioinformatics analysis. Thus, the selection of the most feasible method according with the project’s purpose requires in-depth knowledge of those techniques. Currently, high-throughput sequencing techniques are intensively used in epigenomics profiling, which ultimately aims to find novel biomarkers for detection, diagnosis prognosis, and prediction of response to therapy, as well as to discover new targets for personalized treatments. Here, we present, in brief, a portrayal of next-generation sequencing methodologies’ evolution for profiling DNA methylation, highlighting its potential for translational medicine and presenting significant findings in several diseases.This research was funded by Research Center—Portuguese Oncology Institute of Porto (CI-IPOFB-GEBC-2018 and FCT (POCI-01-0145-FEDER-29043). D.B.-S. is a research fellow from CI-IPOP (BI-GEBC2018/UID/DTP/00776/POCI-01-0145-FEDER-006868), and C.J.M. is a FCT Investigador (FCT contract IF/00047/2012)