Time-lapse monitoring of fluid induced geophysical property variations within an unstable earthwork using P-wave refraction

A significant portion of the UK’s transportation system relies on a network of geotechnical earthworks (cuttings and embankments) that were constructed more than 100 years ago, whose stability is affected by the change in precipitation patterns experienced over the past few decades. The vulnerability of these structures requires a reliable, cost- and time-effective monitoring of their geomechanical condition. We have assessed the potential application of P-wave refraction for tracking the seasonal variations of seismic properties within an aged clay-filled railway embankment, located in southwest England. Seismic data were acquired repeatedly along the crest of the earthwork at regular time intervals, for a total period of 16 months. P-wave first-break times were picked from all available recorded traces, to obtain a set of hodocrones referenced to the same spatial locations, for various dates along the surveyed period of time. Traveltimes extracted from each acquisition were then compared to track the pattern of their temporal variability. The relevance of such variations over time was compared with the data experimental uncertainty. The multiple set of hodocrones was subsequently inverted using a tomographic approach, to retrieve a time-lapse model of VPVP for the embankment structure. To directly compare the reconstructed VPVP sections, identical initial models and spatial regularization were used for the inversion of all available data sets. A consistent temporal trend for P-wave traveltimes, and consequently for the reconstructed VPVP models, was identified. This pattern could be related to the seasonal distribution of precipitation and soil-water content measured on site.

Building professionalism and employability skills: embedding employer engagement within first-year computing modules

This paper outlines a means of improving the employability skills of first-year university students through a closely integrated model of employer engagement within computer science modules. The outlined approach illustrates how employability skills, including communication, teamwork and time management skills, can be contextualised in a manner that directly relates to student learning but can still be linked forward into employment. The paper tests the premise that developing employability skills early within the curriculum will result in improved student engagement and learning within later modules. The paper concludes that embedding employer participation within first-year models can help relate a distant notion of employability into something of more immediate relevance in terms of how students can best approach learning. Further, by enhancing employability skills early within the curriculum, it becomes possible to improve academic attainment within later modules.

Functional expression of TRPV4 in human periodontal ligament cells

Background: Periodontal ligament (PDL) cells are exposed to physical forces in vivo in response to mastication, parafunction, speech and orthodontic tooth movement. Although it has been shown that PDL cells perceive and respond directly to mechanical stimulation, the nature of the ion channels that mediate this mechanotransduction remain to be fully elucidated. The transient receptor potential (TRP) superfamily of ion channels is believed to play a critical role in sensory physiology, where they act as transducers for thermal, chemical and mechanical stimuli. Recent studies have shown that members of the vanilloid (TRPV) and ankyrin (TRPA) subfamilies encode mechanosensitive TRPs. The vanilloid family member TRPV4 is one such non selective calcium permeable cationic channel which has been shown to be activated by chemical ligands, hypotonicity, and mechanical stimuli. Objectives: The objective of the current study was to investigate functional expression of TRPV4 in cultured human PDL cells. Methods: Human PDL cells were grown in Dulbecco's Modified Eagle Medium with L-glutamine supplemented with 10% fetal bovine serum (FBS), 100UI/ml penicillin and 100μg/ml streptomycin. Cells in passage 4-6 were used in all experiments. TRPV4 functional expression was determined using ratiometric calcium imaging. Cultured cells were loaded with intracellular Ca2+ probe fura-2 and cells were then stimulated with the TRPV4 agonists, 4alpha-phorbol 12,13-didecanoate (4alpha-PDD), GSK1016790A or hypotonic solution. The TRPV4 antagonist RN 1734 was used to block the corresponding agonist responses. Results: PDL fibroblasts responded to application of TRPV4 agonists and hypotonic stimuli by an increase in intracellular calcium which was attenuated in the presence of the TRPV4 antagonist. Conclusions: We have shown for the first time the functional expression of the mechanosensitive TRPV4 channel in human PDL cells. The molecular identity and mechanisms of activation of mechanosensitive TRP channels in PDL cells merit further investigation.

Real-time estimation of battery internal temperature based on a simplified thermoelectric model

Li-ion batteries have been widely used in the EVs, and the battery thermal management is a key but challenging part of the battery management system. For EV batteries, only the battery surface temperature can be measured in real-time. However, it is the battery internal temperature that directly affects the battery performance, and large temperature difference may exist between surface and internal temperatures, especially in high power demand applications. In this paper, an online battery internal temperature estimation method is proposed based on a novel simplified thermoelectric model. The battery thermal behaviour is first described by a simplified thermal model, and battery electrical behaviour by an electric model. Then, these two models are interrelated to capture the interactions between battery thermal and electrical behaviours, thus offer a comprehensive description of the battery behaviour that is useful for battery management. Finally, based on the developed model, the battery internal temperature is estimated using an extended Kalman filter. The experimental results confirm the efficacy of the proposed method, and it can be used for online internal temperature estimation which is a key indicator for better real-time battery thermal management.

Time-resolved four-wave-mixing spectroscopy for inner-valence transitions

Noncollinear four-wave-mixing (FWM) techniques at near-infrared (NIR), visible, and ultraviolet frequencies have been widely used to map vibrational and electronic couplings, typically in complex molecules. However, correlations between spatially localized inner-valence transitions among different sites of a molecule in the extreme ultraviolet (XUV) spectral range have not been observed yet. As an experimental step toward this goal, we perform time-resolved FWM spectroscopy with femtosecond NIR and attosecond XUV pulses. The first two pulses (XUV-NIR) coincide in time and act as coherent excitation fields, while the third pulse (NIR) acts as a probe. As a first application, we show how coupling dynamics between odd- and even-parity, inner-valence excited states of neon can be revealed using a two-dimensional spectral representation. Experimentally obtained results are found to be in good agreement with ab initio time-dependent R-matrix calculations providing the full description of multielectron interactions, as well as few-level model simulations. Future applications of this method also include site-specific probing of electronic processes in molecules.

Reliability and factorial validity of Adolescent Time Inventory-Time Attitude (ATI-TA) Scores in Scottish and Northern Irish adolescents

The contemporary literature investigating the construct broadly known as time perspective is replete with methodological and conceptual concerns. These concerns focus on the reliability and factorial validity of measurement tools, and the sample-specific modification of scales. These issues continue to hamper the development of this potentially useful psychological construct. An emerging body of evidence has supported the six-factor structure of scores on the Adolescent Time Inventory-Time Attitudes Scale, as well as their reliability. The present study utilized data from the first wave of a longitudinal study in the United Kingdom to examine the reliability, validity, and cross-cultural invariance of the scale. Results showed that the hypothesized six-factor model provided the best fit for the data; all alpha and omega estimates were >. .70; scores on ATI-TA factors related meaningfully to self-efficacy scores; and the factor structure was invariant across both research sites. Results are discussed in the context of the extant temporal literature.

The relationship between time attitudes profiles and self-efficacy, sensation seeking, and alcohol use: An exploratory study

A growing body of research has begun to report on time attitudes which specifically refers to an individual's emotional and evaluative feelings toward the past, the present, and the future. The present study used data from the first wave of a longitudinal cohort study in the United Kingdom. Sample 1 consisted of 1580 adolescents (40% female, 1.7% unreported) in Northern Ireland, while Sample 2 consisted of 813 adolescents (46.7% female, 1.4% unreported) in Scotland. Five similar time attitudes profiles emerged in both countries, with one additional "balanced" profile in Scotland. Results show that there were no substantive differences between profiles in terms of socio-demographic indicators. However, in respect of academic, social and emotional self-efficacy, best results were observed for those with Positive, Ambivalent, and Balanced profiles, with the reverse true for those with Negative, Past Negative, and Pessimistic profiles. Positives were also less likely to report using alcohol.

The effectiveness of peer mentoring in promoting a positive transition to higher education for first-year undergraduate students: a mixed methods systematic review protocol

Background: The global transfer of nursing and midwifery education to higher education institutes has led to student nurses and midwives experiencing challenges previously faced by traditional third-level students, including isolation, loneliness, financial difficulties and academic pressure. These challenges can contribute to increased stress and anxiety levels which may be detrimental to the successful transition to higher education, thus leading to an increase in attrition rates. Peer mentoring as an intervention has been suggested to be effective in supporting students in the transition to third-level education through enhancing a sense of belongingness and improving student satisfaction, engagement and retention rates. This proposed systematic review aims to determine the effectiveness of peer mentoring in enhancing levels of student engagement, sense of belonging and overall satisfaction of first-year undergraduate students following transition into higher education.
Methods: MEDLINE, Web of Knowledge, ProQuest, Embase, CINAHL, ERIC, PsycINFO and CENTRAL databases will be searched for qualitative, quantitative and mixed methods studies on the implementation of peer assessment strategies in higher education institutes (HEIs) or universities for full-time, first-year adult students (>17 years). Included studies will be limited to the English language. The quality of included studies will be assessed using a validated Mixed Methods Appraisal Tool (MMAT). The findings will be presented as a narrative synthesis or meta-analysis as appropriate following sequential explanatory synthesis.
Discussion: The review will provide clear, non-biased evidence-based guidance to all third-level educators on the effectiveness of peer-mentoring programmes for first-year undergraduates. The review is necessary to help establish which type of peer mentoring is most effective. The evidence from qualitative and quantitative studies drawn from the international literature will be utilised to illustrate the best way to implement and evaluate peer mentoring as an effective intervention and will be useful in guiding future research and practice in this area. These findings may be applied internationally across all disciplines.

Fractional calculus on time scales - Cálculo fraccional em escalas temporais

Introduzimos um cálculo das variações fraccional nas escalas temporais ℤ e (hℤ)!. Estabelecemos a primeira e a segunda condição necessária de optimalidade. São dados alguns exemplos numéricos que ilustram o uso quer da nova condição de Euler–Lagrange quer da nova condição do tipo de Legendre. Introduzimos também novas definições de derivada fraccional e de integral fraccional numa escala temporal com recurso à transformada inversa generalizada de Laplace.

Evolution of Koch's postulates: towards a twenty-first century understanding of microbial infection

This editorial discusses strengths and limitations of Koch's postulates reviews modifications that have been used over time, and provides a brief introductory comment to the four papers that comprise the themed section herein.

NAA and STS effects on bract survival time, carbohydrate content, respiration rate and carbohydrate balance of potted Bougainvillea spectabilis Willd

The aims of this work were to deepen the knowledge on the physiology of bract abscission in Bougainvillea spectabilis ‘Killie Campbell’ plants, in what relates to respiration and carbon balance. Using the effects induced by Silver Thiosulphate (STS) and/or Naphtalene Acetic Acid (NAA, at high concentration: 500 mg.l-1) on bract abscission under interior conditions, the relationship between bract survival time (longevity) and, respiration rate or carbohydrate levels, was investigated. Treatments that included NAA were the ones that reduced significantly bract abscission. Unexpectedly, the higher the levels of bract soluble and total carbohydrates, measured at day 10 postproduction (PP), the higher the abscission of bracts. These results show, for the first time, that abscission can positively correlate with non structural carbohydrates levels in the organ that abscise. Bract respiration rate was significantly affected by treatment and postproduction day (PP). Treatments that had higher bract respiration rates (WATER and STS) also had higher levels of non structural carbohydrates in the bracts. Bract respiration rate decreased from day 10 to day 17 PP by approximately 50% (on average of all treatments) and was negatively correlated with bract survival time. In the carbon balance per gram of bract dry weight, the treatments WATER and STS, showed the largest decrease in the content of total carbohydrates and had the highest consumption of carbohydrates through respiration. So, these were the bracts that needed to import a higher amount of carbohydrates per gram of bract dry weight. In the carbon balance for the whole mass of bracts and adjacent stems in an average plant, the treatments WATER and STS continued to allow for the largest decreases in total carbohydrate during postproduction. However, and contradicting the results per gram of bract dry weight, the highest total consumption of carbohydrates by respiration was obtained for the NAA and STS+NAA treatments. It makes sense that bracts that last longer have lower individual carbon consumption while, at the plant level, the increased number of remaining bracts causes a higher overall expenditure. Respiration rate has been used as an indicator of flower longevity, this correlation is here extended for the flower+bract system. Plants that had higher bract respiration rates, most probably, had a higher flow of carbohydrates through the bracts (and flowers), which, in the end, was sensed as a higher carbohydrate level.

Changing patterns of first injection across key periods of the French Harm Reduction Policy: PrimInject, a cross sectional analysis

Background: Monitoring of emerging modes of drug consumption in France has identified new patterns of injection among youths with diverse social backgrounds, which may explain the persistence of high rates of hepatitis C virus infection. The circumstances surrounding the first injection have been poorly documented in the group of heavy drug users and in the context of the French opioid substitution treatment (OST) policy that provides expanded access to high-dosage buprenorphine (BHD). Methods: An Internet survey (Priminject) was conducted from October 2010 to March 2011 with French drug users. Four time periods were compared based on critical dates throughout the implementation of the Harm Reduction Policy in France. Results: Compared with drug users who injected for the first time prior to 1995, the aspects of drug use for users who recently injected for the first time were as follows: (1) experimentation with miscellaneous drugs before the first injection; (2) an older age at the time of first injection; (3) heroin as the drug of choice for an individual’s first injection, notwithstanding the increased usage of stimulant drugs; (4) BHD did not appear to be a pathway to injection; and (5) an increased number of users who injected their first time alone, without the help or presence of another individual. Conclusion: The PrimInject study showed that there is a group of injection drug users that is larger than the group of injection drug users observed in previous studies; therefore, it is necessary to diversify programs to reach the entire spectrum of high-risk users.

BIMP: A real-time biological model of multi-scale keypoint detection in V1

We present an improved, biologically inspired and multiscale keypoint operator. Models of single- and double-stopped hypercomplex cells in area V1 of the mammalian visual cortex are used to detect stable points of high complexity at multiple scales. Keypoints represent line and edge crossings, junctions and terminations at fine scales, and blobs at coarse scales. They are detected by applying first and second derivatives to responses of complex cells in combination with two inhibition schemes to suppress responses along lines and edges. A number of optimisations make our new algorithm much faster than previous biologically inspired models, achieving real-time performance on modern GPUs and competitive speeds on CPUs. In this paper we show that the keypoints exhibit state-of-the-art repeatability in standardised benchmarks, often yielding best-in-class performance. This makes them interesting both in biological models and as a useful detector in practice. We also show that keypoints can be used as a data selection step, significantly reducing the complexity in state-of-the-art object categorisation. (C) 2014 Elsevier B.V. All rights reserved.

Comparing segmentation strategies for efficient video passage retrieval

We compare the effect of different text segmentation strategies on speech based passage retrieval of video. Passage retrieval has mainly been studied to improve document retrieval and to enable question answering. In these domains best results were obtained using passages defined by the paragraph structure of the source documents or by using arbitrary overlapping passages. For the retrieval of relevant passages in a video, using speech transcripts, no author defined segmentation is available. We compare retrieval results from 4 different types of segments based on the speech channel of the video: fixed length segments, a sliding window, semantically coherent segments and prosodic segments. We evaluated the methods on the corpus of the MediaEval 2011 Rich Speech Retrieval task. Our main conclusion is that the retrieval results highly depend on the right choice for the segment length. However, results using the segmentation into semantically coherent parts depend much less on the segment length. Especially, the quality of fixed length and sliding window segmentation drops fast when the segment length increases, while quality of the semantically coherent segments is much more stable. Thus, if coherent segments are defined, longer segments can be used and consequently less segments have to be considered at retrieval time.

Diatom-based characterization of iberian coastal environments at different time scales

Tese de doutoramento, Geologia (Geologia Económica e do Ambiente), Universidade de Lisboa, Faculdade de Ciências, 2014