Air Temperature Distribution and Energy-balance Modelling of a Debris-covered Glacier

Near-surface air temperature is an important determinant of the surface energy balance of glaciers and is often represented by a constant linear temperature gradients (TGs) in models. Spatiotemporal variability in 2 m air temperature was measured across the debris-covered Miage Glacier, Italy, over an 89 d period during the 2014 ablation season using a network of 19 stations. Air temperature was found to be strongly dependent upon elevation for most stations, even under varying meteorological conditions and at different times of day, and its spatial variability was well explained by a locally derived mean linear TG (MG–TG) of −0.0088°C m−1. However, local temperature depressions occurred over areas of very thin or patchy debris cover. The MG–TG, together with other air TGs, extrapolated from both on- and off-glacier sites, were applied in a distributed energy-balance model. Compared with piecewise air temperature extrapolation from all on-glacier stations, modelled ablation, using the MG–TG, increased by <1%, increasing to >4% using the environmental ‘lapse rate’. Ice melt under thick debris was relatively insensitive to air temperature, while the effects of different temperature extrapolation methods were strongest at high elevation sites of thin and patchy debris cover.

How does employer support and educational background effect an Ergonomics Practitioner’s awareness of the relationship between ergonomics and psychosocial hazard control?

There is a growning need to address psychological health and safety in the workplace. Ergonomics tends to be widely recognized for its physical applications, such as ¨office¨ and ¨manual materials handling¨ however the other domains of specialization of ergonomics (cognitive and organizational) appear to be less well known. This study evaluates the level of understanding that professionals who practice ergonomics have of the relation between ergonomics and the control of psychosocial hazards in the workplace. A survey was distributed to ergonomics practitioners and asked them about their awareness of the relation between ergonomics and workplace psychosocial hazard control. Ergonomists and human factors specialists demonstrated a greater awareness of this relationship than other allied occupational groups that also practice ergonomics, however they indicated that there may be difficulties in the “real world” applying these areas of knowledge into practice. Participants who demonstrated a high level of awareness of the relation between ergonomics and psychosocial hazard control demonstrated stronger organizational commitment than participants with a low awareness. Ergonomics practitioners who reported having employer support for professional development also demonstrated a higher degree of awareness of the relation between ergonomics and psychosocial hazard control, as did the professionals who had been practicing in the field the longest. This research provides some insight for professional associations for Ergonomists, employers of Ergonomists, and human resource professionals about how ergonomics practitioners perceive the ergonomics field and the profession as well as their employing organization.

Interactions of pyridinium, pyrrolidinium or piperidinium based ionic liquids with water: measurements and COSMO-RS modelling

Looking for a better knowledge concerning water and ionic liquids (ILs) interactions, a systematic study of the activity coefficients of water in pyridinium, pyrrolidinium and piperidinium-based ILs at 298.2 K is here presented based on water activity measurements. Additionally, the study of the structural effects of the pyridinium-based cation is also pursued. The results show that non-aromatic ILs are interacting more with water than aromatic ones, and among the ortho, meta and para isomers of 1-butyl-methylpyridinium chloride, the ortho position confers a more hydrophilic character to that specific IL. The physicalchemistry of the solutions was interpreted based on dissociation constants, natural bond orbitals and excess enthalpies providing a sound basis for the interpretation of the experimental observations. These results show that hydrogen bonding controls the behavior of these systems, being the anion-water one of the most relevant interactions, but modulated by the anionecation interactions.

Impacts of climate change and species distribution modelling: future scenarios to endangered species in South Brazil.

Earth climate has changed significantly in the last century and the different models indicate that it will continue to change over the next decades, even if the emission of greenhouse gases stop immediately. These changes have impact on different plant populations, as well as in the actual distribution of several species. As plants, in general, have a smaller capacity of dispersion compared with the animals it is likely that they will suffer the impacts of the climate change more intensively.

Using satellite telemetry and environmental niche modelling to inform conservation targets for a long-distance migratory raptor in its wintering grounds

Understanding the ecology of migratory birds during the non-breeding season is necessary for ensuring their conservation. Using satellite telemetry data we describe winter ranging behaviour and movements of pallid harriers Circus macrourus that bred in Kazakhstan. We developed an ecological niche model for the species in Africa, to identify the most suitable wintering areas for pallid harriers and the importance of habitat in determining the location of those areas. We also assessed how well represented suitable areas are in the network of protected areas. Individual harriers showed relatively high fidelity to wintering areas but with potential for interannual changes. The ecological niche model highlighted the importance of open habitats with natural vegetation. Most suitable areas for the species were located in eastern Africa. Suitable areas had a patchy distribution but were relatively well included in the network of protected areas. The preferential use of habitats with natural vegetation by wintering pallid harriers and the patchiness of the most suitable areas highlight the harrier's vulnerability to land-use changes and the associated loss of natural vegetation in Africa. Conservation of harriers could be enhanced by preserving natural grasslands within protected areas and improving habitat management in the human-influenced portions of the species’ core wintering areas.

Impacts of climate change and species distribution modelling: future scenarios to endangered species in South Brazil.

2016

Design and Off-design modelling of advanced Power-to-Gas energy storage systems

Power-to-Gas storage systems have the potential to address grid-stability issues that arise when an increasing share of power is generated from sources that have a highly variable output. Although the proof-of-concept of these has been promising, the behaviour of the processes in off-design conditions is not easily predictable. The primary aim of this PhD project was to evaluate the performance of an original Power-to-Gas system, made up of innovative components. To achieve this, a numerical model has been developed to simulate the characteristics and the behaviour of the several components when the whole system is coupled with a renewable source. The developed model has been applied to a large variety of scenarios, evaluating the performance of the considered process and exploiting a limited amount of experimental data. The model has been then used to compare different Power-to-Gas concepts, in a real scenario of functioning. Several goals have been achieved. In the concept phase, the possibility to thermally integrate the high temperature components has been demonstrated. Then, the parameters that affect the energy performance of a Power-to-Gas system coupled with a renewable source have been identified, providing general recommendations on the design of hybrid systems; these parameters are: 1) the ratio between the storage system size and the renewable generator size; 2) the type of coupled renewable source; 3) the related production profile. Finally, from the results of the comparative analysis, it is highlighted that configurations with a highly oversized renewable source with respect to the storage system show the maximum achievable profit.

Estudo da porção offshore da bacia do Benin e o seu potencial no armazenamento de hidrocarbonetos, margem equatorial africana

Pós-graduação em Geologia Regional - IGCE

Amygdala activation in response to 2D and 3D emotion-inducing stimuli

Studying changes in brain activation according to the valence of emotion-inducing stimuli is essential in the research on emotions. Due to the ecological potential of virtual reality, it is also important to examine whether brain activation in response to emotional stimuli can be modulated by the three-dimensional (3D) properties of the images. This study uses functional Magnetic Resonance Imaging to compare differences between 3D and standard (2D) visual stimuli in the activation of emotion-related brain areas. The stimuli were organized in three virtual-reality scenarios, each with a different emotional valence (pleasant, unpleasant and neutral). The scenarios were presented in a pseudo-randomized order in the two visualization modes to twelve healthy males. Data were analyzed through a GLM-based fixed effects procedure. Unpleasant and neutral stimuli activated the right amygdala more strongly when presented in 3D than in 2D. These results suggest that 3D stimuli, when used as “building blocks” for virtual environments, can induce increased emotional loading, as shown here through neuroimaging.

A Comparison of Radiation Dose Between Standard and 3D Angiography in Congenital Heart Disease

Background: The use of three-dimensional rotational angiography (3D-RA) to assess patients with congenital heart diseases appears to be a promising technique despite the scarce literature available. Objectives: The objective of this study was to describe our initial experience with 3D-RA and to compare its radiation dose to that of standard two-dimensional angiography (2D-SA). Methods: Between September 2011 and April 2012, 18 patients underwent simultaneous 3D-RA and 2D-SA during diagnostic cardiac catheterization. Radiation dose was assessed using the dose-area-product (DAP). Results: The median patient age and weight were 12.5 years and 47.5 Kg, respectively. The median DAP of each 3D-RA acquisition was 1093µGy.m2 and 190µGy.m2 for each 2D-SA acquisition (p<0.01). In patients weighing more than 45Kg (n=7), this difference was attenuated but still significant (1525 µGy.m2 vs.413µGy.m2, p=0.01). No difference was found between one 3D-RA and three 2D-SA (1525µGy.m2 vs.1238 µGy.m2, p = 0.575) in this population. This difference was significantly higher in patients weighing less than 45Kg (n=9) (713µGy.m2 vs.81µGy.m2, P = 0.008), even when comparing one 3D-RA with three 2D-SA (242µGy.m2, respectively, p<0.008). 3D-RA was extremely useful for the assessment of conduits of univentricular hearts, tortuous branches of the pulmonary artery, and aorta relative to 2D-SA acquisitions. Conclusions: The radiation dose of 3D-RA used in our institution was higher than those previously reported in the literature and this difference was more evident in children. This type of assessment is of paramount importance when starting to perform 3D-RA.

Modelling spectral reflectance of open cork oak woodland: a simulation analysis of the effects of vegetation structure and background

This study analyses the influence of vegetation structure (i.e. leaf area index and canopy cover) and seasonal background changes on moderate-resolution imaging spectrometer (MODIS)-simulated reflectance data in open woodland. Approximately monthly spectral reflectance and transmittance field measurements (May 2011 to October 2013) of cork oak tree leaves (Quercus suber) and of the herbaceous understorey were recorded in the region of Ribatejo, Portugal. The geometric-optical and radiative transfer (GORT) model was used to simulate MODIS response (red, near-infrared) and to calculate vegetation indices, investigating their response to changes in the structure of the overstorey vegetation and to seasonal changes in the understorey using scenarios corresponding to contrasting phenological status (dry season vs. wet season). The performance of normalized difference vegetation index (NDVI), soil-adjusted vegetation index (SAVI), and enhanced vegetation index (EVI) is discussed. Results showed that SAVI and EVI were very sensitive to the emergence of background vegetation in the wet season compared to NDVI and that shading effects lead to an opposing trend in the vegetation indices. The information provided by this research can be useful to improve our understanding of the temporal dynamic of vegetation, monitored by vegetation indices.

Advanced morphological 3D magnetic resonance observation of cartilage repair tissue (MOCART) scoring using a new isotropic 3D proton-density, turbo spin echo sequence with variable flip angle distribution (PD-SPACE) compared to an isotropic 3D steady-state free precession sequence (True-FISP) and standard 2D sequences

To evaluate a new isotropic 3D proton-density, turbo-spin-echo sequence with variable flip-angle distribution (PD-SPACE) sequence compared to an isotropic 3D true-fast-imaging with steady-state-precession (True-FISP) sequence and 2D standard MR sequences with regard to the new 3D magnetic resonance observation of cartilage repair tissue (MOCART) score.

Reconstruction of patient-specific 3D bone surface from 2D calibrated fluoroscopic images and point distribution model

Reconstruction of patient-specific 3D bone surface from 2D calibrated fluoroscopic images and a point distribution model is discussed. We present a 2D/3D reconstruction scheme combining statistical extrapolation and regularized shape deformation with an iterative image-to-model correspondence establishing algorithm, and show its application to reconstruct the surface of proximal femur. The image-to-model correspondence is established using a non-rigid 2D point matching process, which iteratively uses a symmetric injective nearest-neighbor mapping operator and 2D thin-plate splines based deformation to find a fraction of best matched 2D point pairs between features detected from the fluoroscopic images and those extracted from the 3D model. The obtained 2D point pairs are then used to set up a set of 3D point pairs such that we turn a 2D/3D reconstruction problem to a 3D/3D one. We designed and conducted experiments on 11 cadaveric femurs to validate the present reconstruction scheme. An average mean reconstruction error of 1.2 mm was found when two fluoroscopic images were used for each bone. It decreased to 1.0 mm when three fluoroscopic images were used.

2D and 3D crystallization of a bacterial homologue of human vitamin C membrane transport proteins

Most organisms are able to synthesize vitamin C whereas humans are not. In order to contribute to the elucidation of the molecular working mechanism of vitamin C transport through biological membranes, we cloned, overexpressed, purified, functionally characterized, and 2D- and 3D-crystallized a bacterial protein (UraDp) with 29% of amino acid sequence identity to the human sodium-dependent vitamin C transporter 1 (SVCT1). Ligand-binding experiments by scintillation proximity assay revealed that uracil is a substrate preferably bound to UraDp. For structural analysis, we report on the production of tubular 2D crystals and present a first projection structure of UraDp from negatively stained tubes. On the other hand the successful growth of UraDp 3D crystals and their crystallographic analysis is described. These 3D crystals, which diffract X-rays to 4.2Å resolution, pave the way towards the high-resolution crystal structure of a bacterial homologue with high amino acid sequence identity to human SVCT1.