CO₂ minimum miscibility pressure determination of pure hydrocarbons in different temperatures using slimtube simulations

As wind energy deployment increases and larger wind-power plants are considered, bird fatalities through collision with moving turbine rotor blades are expected to increase. However, few (cost-) effective deterrent or mitigation measures have so far been developed to reduce the risk of collision. Provision of “passive” visual cues may enhance the visibility of the rotor blades enabling birds to take evasive action in due time. Laboratory experiments have indicated that painting one of three rotor blades black minimizes motion smear (Hodos 2003, Minimization of motion smear: Reducing avian collisions with wind turbines). We tested the hypothesis that painting would increase the visibility of the blades, and that this would reduce fatality rates in situ, at the Smøla wind-power plant in Norway, using a Before–After–Control–Impact approach employing fatality searches. The annual fatality rate was significantly reduced at the turbines with a painted blade by over 70%, relative to the neighboring control (i.e., unpainted) turbines. The treatment had the largest effect on reduction of raptor fatalities; no white-tailed eagle carcasses were recorded after painting. Applying contrast painting to the rotor blades significantly reduced the collision risk for a range of birds. Painting the rotor blades at operational turbines was, however, resource demanding given that they had to be painted while in-place. However, if implemented before construction, this cost will be minimized. It is recommended to repeat this experiment at other sites to ensure that the outcomes are generic at various setting

Six pelagic seabird species of the North Atlantic engage in a fly-and-forage strategy during their migratory movements

Bird migration is commonly defined as a seasonal movement between breeding and non-breeding grounds. It generally involves relatively straight and directed large-scale movements, with a latitudinal change, and specific daily activity patterns comprising less or no foraging and more traveling time. Our main objective was to describe how this general definition applies to seabirds. We investigated migration characteristics of 6 pelagic seabird species (little auk Alle alle, Atlantic puffin Fratercula arctica, common guillemot Uria aalge, Brünnich’s guillemot U. lomvia, black-legged kittiwake Rissa tridactyla and northern fulmars Fulmarus glacialis). We analysed an extensive geolocator positional and saltwater immersion dataset from 29 colonies in the North-East Atlantic and across several years (2008-2019). We used a novel method to identify active migration periods based on segmentation of time series of track characteristics (latitude, longitude, net-squared displacement). Additionally, we used the saltwater immersion data of geolocators to infer bird activity. We found that the 6 species had, on average, 3 to 4 migration periods and 2 to 3 distinct stationary areas during the non-breeding season. On average, seabirds spent the winter at lower latitudes than their breeding colonies and followed specific migration routes rather than non-directionally dispersing from their colonies. Differences in daily activity patterns were small between migratory and stationary periods, suggesting that all species continued to forage and rest while migrating, engaging in a ‘fly-and-forage’ migratory strategy. We thereby demonstrate the importance of habitats visited during seabird migrations as those that are not just flown over, but which may be important for re-fuelling.publishedVersio

Twilight foraging enables European shags to survive the winter across their latitudinal range

Species breeding at high latitudes face a significant challenge of surviving the winter. Such conditions are particularly severe for diurnal marine endotherms such as seabirds. A critical question is therefore what behavioural strategies such species adopt to maximise survival probability. We tested 3 hypotheses: (1) they migrate to lower latitudes to exploit longer day length (‘sun-chasing’), (2) they forage at night (‘night-feeding’), or (3) they target high-quality food patches to minimise foraging time (‘feasting’). We studied the winter migration and foraging strategies of European shags Phalacrocorax aristotelis from 6 colonies across a latitudinal gradient from temperate regions to north of the Arctic Circle using geolocators deployed over 11 winters. We found evidence for ‘sun-chasing’, whereby average southerly movements were greatest from colonies at higher latitudes. However, a proportion of individuals from higher latitudes remained resident in winter and, in the absence of daylight, they foraged during twilight and only very occasionally during the night. At lower latitudes, there was little evidence that individuals migrated south, nocturnal feeding was absent, and twilight feeding was infrequent, suggesting that there was sufficient daylight in winter. There was no evidence that winter foraging time was lowest at higher latitudes, as predicted by the ‘feasting’ hypothesis. Our results suggest that shags adopt different behavioural strategies to survive the winter across their latitudinal range, dictated by the differing light constraints. Our study highlights the value of multi-colony studies in testing key hypotheses to explain population persistence in seabird species that occur over large latitudinal ranges

Perception and Action using Multilinear Forms

Abstract In this paper it is shown how multilinear forms can be used in the perception-action cycle. Firstly, these forms can be used to reconstruct an unknown (or partially known) scene from image sequences only. Secondly, from this reconstruction the movement of the camera can be calculated with respect to the scene, which solves the so called hand-eye calibration problem. Then action can be carried out when this relative orientation is known. The results are that it is sufficient to either use bilinear forms between every successive pair of images plus bilinear forms between every second image or trilinear forms between successive triplets of images. We also present a robust and accurate method to obtain reconstruction and hand-eye calibration from a sequence of images taken by uncalibrated cameras, based on multilinear forms. This algorithm requires no initialisation and gives a generic solution in a sense that is clearly specified. Finally, the algorithms are illustrated using real image sequences, showing that reconstruction can be made and that the hand-eye calibration is obtained.

A case report of a patient with metastatic ocular melanoma who experienced a response to treatment with the BRAF inhibitor vemurafenib

Background: Conjunctival malignant melanoma (CMM) is a rare malignancy and in the advanced setting there is no effective treatment. In contrast, half of cutaneous melanomas have BRAF mutations and treatment with BRAF inhibitors is established for patients with disseminated disease. The most common form of ocular melanoma, uveal melanoma, lacks these mutations, however, their presence has been reported for CMM. Case presentation: We used the BRAF inhibitor vemurafenib to treat a 53 year-old female suffering from a BRAFV600E mutated metastatic CMM. The patient benefited from the treatment, a response was evident within a week and she experienced a progression free survival of four months. Conclusions: To our knowledge, this is the first described case of response to vemurafenib treatment in a patient with ocular melanoma

A Computer Vision Toolbox

Computer vision is a hot research topic. The goal is to empower a computer or robot with vision, similar to the human visual system. Some of the typical subproblems are: reconstruction of a three-dimensional scene from a set of images, recognition of previously seen objects, and calculation of camera motion relative to the scene. This has proved to be an extremely difficult task. However, some of these problems can be solved in simple cases. As an example, the calculation of three-dimensional structure and camera motion relative to the scene, the so called structure and motion problem, is more or less solved for the case of point configurations. We will present different tools, implemented in MATLAB, that performs a number of computer vision tasks. The paper also includes examples of experiments and point out possible applications. 1 Introduction Computer vision is a rapidly growing research field, with activities all over the world. The field is of importance for such various applic..

Do birds respond to spiral markers on overhead wires of a high-voltage power line? Insights from a dedicated avian radar

Growing human population demands the expansion of the energy transmission grid. Power lines represent a major death hazard for many species, especially birds. Addressing such a human-wildlife conflict requires detailed knowledge of how species use the aerial space and how they react to mitigation measures, such as flight markers. Here, we use a dedicated avian radar to study birds’ flight behaviour at marked and unmarked sections of a power line in Norway. We investigate the effect of wire marking on the density of bird tracks, multidirectionality, perpendicularity and turning angle at increasing distance from a power line as well as the maximum turning angles and track height. In addition, the avian radar allowed us to compare flight behaviour between daytime and night-time. The density of bird tracks was lower during the daytime (when markers are visible) compared to night-time (markers are not visible). Furthermore, bird tracks (i) were more directional during daytime, especially at the marked section, (ii) were less perpendicular to the power line at the marked compared to the unmarked section, and (iii) performed more pronounced turning angles at the unmarked compared to the marked section. Moreover, tracks’ maximum turning angle was largest at the unmarked section and the average track height was greater at the marked section of the power line. Our findings provide new correlative evidence of changes in birds’ flight behaviour induced by flight markers on a power line’s earth wire. Furthermore, we highlight the adequacy of dedicated avian radars to assess the efficiency of conservation interventions mitigating the impacts of overhead energy infrastructure (power lines, wind turbines) on the use of the aerial space by animals.publishedVersio