Personalised Trachea Stent Designer: a Knowledge Feature

Modelling of anatomical parts is usually tackled through triangulated models with specialised Bio-CAD applications. If features beyond anatomy are required, geometry is usually translated into NURBS geometry for further modification in parametric feature based design CAD systems. But, they remain quite unmanageable yet. The authors present, validate and implement into a knowledge feature a methodology that generates an anatomically personalised trachea stent based a point cloud data extracted from a Computerised Axial Tomography with an open-source medical data visualisation application

A two-dimensional finite element model of front surface current flow in cells under non-uniform, concentrated illumination

A two-dimensional finite element model of current flow in the front surface of a PV cell is presented. In order to validate this model we perform an experimental test. Later, particular attention is paid to the effects of non-uniform illumination in the finger direction which is typical in a linear concentrator system. Fill factor, open circuit voltage and efficiency are shown to decrease with increasing degree of non-uniform illumination. It is shown that these detrimental effects can be mitigated significantly by reoptimization of the number of front surface metallization fingers to suit the degree of non-uniformity. The behavior of current flow in the front surface of a cell operating at open circuit voltage under non-uniform illumination is discussed in detail

Magnetite-supported palladium single-atoms do not catalyse the hydrogenation of alkenes but small clusters do

The activity of supported noble metal catalysts strongly depends on the particle size. The ultimate small-size limit is the single-atom catalyst (SAC), which maximizes the catalytic efficiency in the majority of the examples. Here, we investigate the catalytic behavior of Pd SACs supported on magnetite nanoparticles and we unambiguously demonstrate that Pd SACs are absolutely inactive in the hydrogenation of various alkene substrates. Instead, Pd clusters of low atomicity exhibit outstanding catalytic performance.Postprint (author's final draft

Food availability affects the scent marking frequencies of wild brown bears

For many species, chemical signalling is used to signal the competitive ability of individuals and therefore plays an important role in the breeding system. As breeding generally promotes intrasexual competition, the potential fitness costs associated with competitive behaviour may be mitigated if individuals are able to assess their own ability, and the competitive ability of others, prior to agonistic encounters. Due to their hierarchical social structure and large home-range size, bears (Ursidae) are thought to rely highly on olfactory methods of communication. Through camera traps orientated towards bear ‘rub trees’ over a three-year period, we have begun to establish the function of strategic tree selectivity and the social function of marking behaviour for brown bears Ursus arctos in the Glendale drainage, British Columbia. We hypothesised that marking trees function to signal competitive ability between individuals, with dominant individuals signalling their high competitive ability and receivers detecting these cues and modifying their behaviour accordingly. Here, we provide evidence to further these hypotheses by demonstrating how scent marking frequencies vary in relation to food availability

Inter-sexual and inter-seasonal differences in the chemical signalling strategies of brown bears

The brown bear (Ursus arctos) is a species which, due to its solitary, dominance hierarchy social system and large home range, is thought to rely heavily on chemical signals as a means of communication. Through camera traps orientated towards bear ‘rub trees’ over a two-year period, we assessed the proportional contribution of scent marking in different seasons by different age sex classes, and gained insights into the role of chemical signalling in maintaining social structure. We found, during the breeding season (June-July), that both adult males (n=38 P1 year (n=11 P=0.003) scent marked trees significantly more often than expected, whereas lone adult females (n=7) and subadults (n=3) marked less than expected. Outside of the breeding season (August-October), adult males (n=70) marked in an expected proportion, females with cubs (all ages) marked significantly more than expected (n=71 P<0.001), and lone adult females (n=11) and subadults (n=15) marked less than expected. During both the breeding season (n=7 P=0.026) and the fall (n=11 P<0.001), adult females marked trees significantly less than their occurrence on bear trails would expect, as did subadults during the breeding season (n=3 P=0.026) but not during the fall (n=15). Adult males marked at significantly high frequencies both during and outside of the breeding season, potentially to communicate dominance between males. Supported by the low frequency of scent marking by subadults. We observed a total avoidance of bear trails containing active rub trees by females with cubs <1 year during the breeding season, a possible counterstrategy to sexually selected infanticide due to the strong male bias in scent marking during the breeding season. We hypothesize that scent marking in brown bears is taught by the mother, beginning with cubs <1 year outside of the breeding season at a relatively ‘safe’ time of year

Using Markov Chain Analysis to assess stereotyped scent marking behaviour in wild brown bears

Members of the order Carnivora employ a wide range of postures and stereotyped patterns to mark their scent onto objects, and therein communicate with conspecifics. Despite much anecdotal evidence on the marking behaviour of Ursids, empirical data examining marking patterns displayed by wild populations is lacking. Situated on the west coast of British Columbia (2009-2011), we used trail cameras stationed at marking trees to investigate scent marking and investigatory behaviour by wild brown bears Ursus arctos. Transitions between postures were assessed using Markov Chain Analysis. Results showed that scent marking patterns varied by age and sex; adult males exhibited a cyclic pattern of marking behaviour which included ‘core’ and ‘secondary’ postures, whereas adult females failed to exhibit any subset postures. The behaviour of subadults (sexes combined) was a variation and simplification of the patterns displayed by adult males and females. The wider variety of marking postures selected by adult males may convey a more complex signal, relating to the function of scent marking in the species. Females with young were classified separately to assess potential similarities/differences in the behaviour of all members of the family group. Using a simplified ethogram, we found the behaviour of cubs to be dependent on their age and the behaviour of their mother. Younger cubs were more likely to conduct the same behaviour as their mother, whereas older cubs exhibited behaviours independently. This study presents the first detailed description of the development of scent marking behaviour by cubs in the Ursidae

Assessing the scent marking behaviour of wild brown bears: an exploration of time and energy investment, motor patterns and age-related development

Members of the order Carnivora employ a wide range of postures and stereotyped patterns to mark their scent onto objects and thereby communicate with conspecifics. Despite much anecdotal evidence on the marking behaviour of ursids, empirical evidence of scent marking motor patterns displayed by wild populations is lacking. Analysing the time bears spend at marking trees and the behaviours involved, could provide further insight into the function of marking and highlight time and energy investment. Over a three year period, camera traps stationed at marking trees were used to investigate scent marking and investigatory behaviour by wild brown bears Ursus arctos in coastal British Columbia. This work follows on from data presented at the 18th, 19th & 20th IBA conferences

Role of the LPA1 receptor in mood and emotional regulation

Depression is a debilitating psychiatric condition characterized by anhedonia and behavioural despair among others symptoms. Despite the high prevalence and devastating impact of depression, underlying neurobiological mechanisms of mood disorders are still not well known. Regardless its complexity, central features of this disease can be modelled in rodents in order to better understand the potential mechanisms underlying. On the other hand, the lack of LPA1 receptor compromises the morphological and functional integrity of the limbic circuit and the neurogenesis in hippocampus, induces cognitive alterations on hippocampal-dependent tasks and dysfunctional coping of chronic stress, provokes exaggerated endocrine responses to emotional stimuli and impairs adaptation of the hypothalamic-pituitary-adrenal axis after chronic stress. Factors, which all have been related with depression. Here, we sought to establish the involvement of the LPA1 receptor in regulation of mood and emotion. To this end, in wild-type and maLPA1-null mice active coping responses to stress were examined using the forced swimming test (FST). To assess hedonic behaviour saccharine preference test and female urine sniffing test were used. Our data indicated that the absence of the LPA1 receptor significantly affected to coping strategies. Thus, while null mice displayed less immobility than wt in FST, exhibited more climbing and less swimming behaviour, responses that could be interpreted as an emotional over-reaction (i.e., a panic-like response) to stress situations. Concerning hedonic behaviour, the lack of the LPA1 receptor diminished saccharin preference and female urine sniffing time. Overall, these data supports the role of LPA1 receptor in mood and emotional regulation. Specially, the lack of this receptor induced emotional dysregulation and anhedonic behaviour, a core symptom of depression.Universidad de Málaga, Campus de Excelencia Andalucía Tech. Andalusian Regional Ministries of Economy, Innovation, Science and Employment (SEJ-1863; CTS643) and of Health (PI-0234-2013; Nicolas Monardes Programme), MINECO (PSI2013-44901-P) and National Institute of Health Carlos III (Sara Borrel)