Future wave climate over the west-European shelf seas

In this paper, we investigate changes in the wave climate of the west-European shelf seas under global warming scenarios. In particular, climate change wind fields corresponding to the present (control) time-slice 1961–2000 and the future (scenario) time-slice 2061–2100 are used to drive a wave generation model to produce equivalent control and scenario wave climate. Yearly and seasonal statistics of the scenario wave climates are compared individually to the corresponding control wave climate to identify relative changes of statistical significance between present and future extreme and prevailing wave heights. Using global, regional and linked global–regional wind forcing over a set of nested computational domains, this paper further demonstrates the sensitivity of the results to the resolution and coverage of the forcing. It suggests that the use of combined forcing from linked global and regional climate models of typical resolution and coverage is a good option for the investigation of relative wave changes in the region of interest of this study. Coarse resolution global forcing alone leads to very similar results over regions that are highly exposed to the Atlantic Ocean. In contrast, fine resolution regional forcing alone is shown to be insufficient for exploring wave climate changes over the western European waters because of its limited coverage. Results obtained with the combined global–regional wind forcing showed some consistency between scenarios. In general, it was shown that mean and extreme wave heights will increase in the future only in winter and only in the southwest of UK and west of France, north of about 44–45° N. Otherwise, wave heights are projected to decrease, especially in summer. Nevertheless, this decrease is dominated by local wind waves whilst swell is found to increase. Only in spring do both swell and local wind waves decrease in average height

Dynamics of methane ebullition from a peat monolith revealed from a dynamic flux chamber system

Methane (CH4) ebullition in northern peatlands is poorly quantified in part due to its high spatiotemporal variability. In this study, a dynamic flux chamber (DFC) system was used to continuously measure CH4 fluxes from a monolith of near‐surface Sphagnum peat at the laboratory scale to understand the complex behavior of CH4 ebullition. Coincident transmission ground penetrating radar measurements of gas content were also acquired at three depths within the monolith. A graphical method was developed to separate diffusion, steady ebullition, and episodic ebullition fluxes from the total CH4 flux recorded and to identify the timing and CH4 content of individual ebullition events. The results show that the application of the DFC had minimal disturbance on air‐peat CH4 exchange and estimated ebullition fluxes were not sensitive to the uncertainties associated with the graphical model. Steady and episodic ebullition fluxes were estimated to be averagely 36 ± 24% and 38 ± 24% of the total fluxes over the study period, respectively. The coupling between episodic CH4 ebullition and gas content within the three layers supports the existence of a threshold gas content regulating CH4 ebullition. However, the threshold at which active ebullition commenced varied between peat layers with a larger threshold (0.14 m3 m−3) observed in the deeper layers, suggesting that the peat physical structure controls gas bubble dynamics in peat. Temperature variation (23°C to 27°C) was likely only responsible for small episodic ebullition events from the upper peat layer, while large ebullition events from the deeper layers were most likely triggered by drops in atmospheric pressure

Assessing students’ engagement: A review of instruments with psychometric Qualities

Este E-Book reúne um conjunto de investigações apresentadas no “I Congresso Internacional Envolvimento dos Alunos na Escola: Perspetivas da Psicologia e Educação” (ICIEAE), organizado no âmbito do “Projeto PTDC/CPE-CED/114362/2009 - Envolvimento dos Alunos na Escola: Diferenciação e Promoção” (EAE-DP), financiado pela Fundação para a Ciência e a Tecnologia (FCT).Framework: Students Engagement in School (SES) has been occupying a central position in the discussions regarding factors of academic success and school dropout. A considerable amount of literature on this concept exists. Although its conceptualization varies according to authors and the theoretical framework they have adopted, there is a wide agreement concerning its multidimensional nature. Key dimensions of students engagement in school (i.e., cognitive, affective, behavioral and, more recently, agentic) have been described and empirically validated. Purpose:This study aimed to review the literature on assessment of students engagement in school through a focus on the psychometric characteristics of several instruments. Methodology: The present paper focuses on self-report measures which are multidimensional. These instruments were validated on heterogeneous samples. Results: Twelve self-report measures designed to measure the students engagement in school were referred, along with four other instruments targeting teachers’ perspective as well as observational measures. Conclusions: Various measures stem from different theoretical perspectives and were developed with different types of samples. Conceptual variations often expressed in the number of dimensions considered and in items content variability suggest limitations when comparing psychometric indings of different studies. Suggestions: Studies on instruments we reviewed in the present paper suggest the need for further research on the multidimensionality of school engagement construct. Research should go beyond investigation of differential and predictive validity of measures. Thus, there is little evidence regarding the validity of engagement in school measures, when investigation of effects of specific intervention programs is aimed or validity of their use in quasiexperimental studies with useful applications in the field of education

An Investigation on Cooling of CZT Co-Planar Grid Detectors

The effect of moderate cooling on CdZnTe semiconductor detectors has been studied for the COBRA experiment. Improvements in energy resolution and low energy threshold were observed and quantified as a function of temperature. Leakage currents are found to contribute typically $\sim$5 keV to the widths of photopeaks.Comment: 14 pages, 9 figures. Accepted for publication in Nuclear Inst. and Methods in Physics Research,

Evaluation of a hand-held point-of-care analyser for measurement of creatinine in cats

ObjectivesThe aim of the study was to evaluate whether a handheld creatinine analyser (StatSensor Xpress; SSXp), available for human patients, can be used to measure creatinine reliably in cats.MethodsAnalytical performance was evaluated by determining within- and between-run coefficient of variation (CV, %), total error observed (TEobs, %) and sigma metrics. Fifty client-owned cats presenting for investigation of clinical disease had creatinine measured simultaneously, using SSXp (whole blood and plasma) and a reference instrument (Konelab, serum); 48 paired samples were included in the study. Creatinine correlation between methodologies (SSXp vs Konelab) and sample types (SSXpwhole bloodvs SSXpplasma) was assessed by Spearman’s correlation coefficient and agreement was determined using Bland–Altman difference plots. Each creatinine value was assigned an IRIS stage (1–4); correlation and agreement between Konelab and SSXp IRIS stages were evaluated.ResultsWithin-run CV (4.23–8.85%), between-run CV (8.95–11.72%), TEobs(22.15–34.92%) and sigma metrics (⩽3) did not meet desired analytical requirements. Correlation between sample types was high (SSXpwhole bloodvs SSXpplasma; r = 0.89), and between instruments was high (SSXpwhole bloodvs Konelabserum; r = 0.85) to very high (SSXpplasmavs Konelabserum; r = 0.91). Konelab and SSXpwhole bloodIRIS scores exhibited high correlation ( r = 0.76). Packed cell volume did not significantly affect SSXp determination of creatinine. Bland–Altman difference plots identified a positive bias for the SSXp (7.13 μmol/l SSXpwhole blood; 20.23 μmol/l SSXpplasma) compared with the Konelab. Outliers (1/48 whole blood; 2/48 plasma) occurred exclusively at very high creatinine concentrations. The SSXp failed to identify 2/21 azotaemic cats.Conclusions and relevanceAnalytical performance of the SSXp in feline patients is not considered acceptable. The SSXp exhibited a high to very high correlation compared with the reference methodology but the two instruments cannot be used interchangeably. Improvements in the SSXp analytical performance are needed before its use can be recommended in feline clinical practice.</jats:sec

Interaction anisotropy and random impurities effects on the critical behaviour of ferromagnets

The theory of phase transitions is based on the consideration of "idealized" models, such as the Ising model: a system of magnetic moments living on a cubic lattice and having only two accessible states. For simplicity the interaction is supposed to be restricted to nearest--neighbour sites only. For these models, statistical physics gives a detailed description of the behaviour of various thermodynamic quantities in the vicinity of the transition temperature. These findings are confirmed by the most precise experiments. On the other hand, there exist other cases, where one must account for additional features, such as anisotropy, defects, dilution or any effect that may affect the nature and/or the range of the interaction. These features may have impact on the order of the phase transition in the ideal model or smear it out. Here we address two classes of models where the nature of the transition is altered by the presence of anisotropy or dilution.Comment: 11 pages, 4 figures, To appear in Journal of Physics: Conference Serie

Sleep quality in individuals diagnosed with colorectal cancer: Factors associated with sleep disturbance as patients transition off treatment

To identify patient characteristics associated with sleep disturbance and worsening of sleep in individuals diagnosed with localized colorectal cancer and assess heterogeneity in these relationships. Methods: Data were from the MY-Health study, a community-based observational study of adults diagnosed with cancer. Patient-Reported Outcomes Measurement Information System® Sleep Disturbance, Anxiety, Depression, Fatigue, and Pain Interference measures were administered. Participants self-reported demographics, comorbidities, and treatment information. Regression mixture and multiple regression models were used to evaluate the relationship between sleep disturbance and patient characteristics cross-sectionally at an average of 10 months after diagnosis (n = 613) as well as change in sleep disturbance over a 6-month period (n = 361). Results: Pain, anxiety, fatigue, and the existence of multiple comorbid conditions had statistically significant relationships with sleep disturbance (B = 0.09, 0.22, 0.29, and 1.53, respectively; P < 0.05). Retirement (B = -2.49) was associated with sleep quality in the cross-sectional model. Worsening anxiety (B = 0.14) and fatigue (B = 0.20) were associated with worsening sleep disturbance, and more severe sleep disturbance 10 months after diagnosis (B = -0.21) was associated with improvement in sleep quality after diagnosis (P < 0.05). No evidence of latent subgroups of patients (heterogeneity) was present. Conclusions: Pain, anxiety, fatigue, employment, and comorbid conditions were associated with sleep disturbance, but regression coefficients were small (< |2.5|). Results suggest that screening for anxiety, depression, fatigue, or pain is not sufficient for identifying sleep disturbance. Given the negative consequences of sleep disturbance, sleep disturbance screening may be warranted