52 research outputs found
In vivo comparison of arterial lumen dimensions assessed by co-registered three-dimensional (3D) quantitative coronary angiography, intravascular ultrasound and optical coherence tomography
This study sought to compare lumen dimensions as assessed by 3D quantitative coronary angiography (QCA) and by intravascular ultrasound (IVUS) or optical coherence tomography (OCT), and to assess the association of the discrepancy with vessel curvature. Coronary lumen dimensions often show discrepancies when assessed by X-ray angiography and by IVUS or OCT. One source of error concerns a possible mismatch in the selection of corresponding regions for the comparison. Therefore, we developed a novel, real-time co-registration approach to guarantee the point-to-point correspondence between the X-ray, IVUS and OCT images. A total of 74 patients with indication for cardiac catheterization were retrospectively included. Lumen morphometry was performed by 3D QCA and IVUS or OCT. For quantitative analysis, a novel, dedicated approach for co-registration and lumen detection was employed allowing for assessment of lumen size at multiple positions along the vessel. Vessel curvature was automatically calculated from the 3D arterial vessel centerline. Comparison of 3D QCA and IVUS was performed in 519 distinct positions in 40 vessels. Correlations were r = 0.761, r = 0.790, and r = 0.799 for short diameter (SD), long diameter (LD), and area, respectively. Lumen sizes were larger by IVUS (P < 0.001): SD, 2.51 ± 0.58 mm versus 2.34 ± 0.56 mm; LD, 3.02 ± 0.62 mm versus 2.63 ± 0.58 mm; Area, 6.29 ± 2.77 mm2versus 5.08 ± 2.34 mm2. Comparison of 3D QCA and OCT was performed in 541 distinct positions in 40 vessels. Correlations were r = 0.880, r = 0.881, and r = 0.897 for SD, LD, and area, respectively. Lumen sizes were larger by OCT (P < 0.001): SD, 2.70 ± 0.65 mm versus 2.57 ± 0.61 mm; LD, 3.11 ± 0.72 mm versus 2.80 ± 0.62 mm; Area 7.01 ± 3.28 mm2versus 5.93 ± 2.66 mm2. The vessel-based discrepancy between 3D QCA and IVUS or OCT long diameters increased with increasing vessel curvature. In conclusion, our comparison of co-registered 3D QCA and invasive imaging data suggests a bias towards larger lume
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Effects of degree and timing of social housing on reversal learning and response to novel objects in dairy calves
Rodents and primates deprived of early social contact exhibit deficits in learning and behavioural
flexibility. They often also exhibit apparent signs of elevated anxiety, although the relationship between these effects has not been studied. To investigate whether dairy calves are similarly affected, we first compared calves housed in standard individual pens
(n = 7) to those housed in a dynamic group with access to their mothers (n = 8). All calves learned to approach the correct stimulus in a visual discrimination task. Only one individually housed calf was able to re-learn the task when the stimuli were reversed, compared to all but one calf from the group. A second experiment investigated whether this effect might be explained by anxiety in individually housed animals interfering with their learning, and tested varying degrees of social contact in addition to the complex group: pair housing beginning early (approximately 6 days old) and late (6 weeks old). Again, fewer individually reared calves learned the reversal task (2 of 10 or 20%) compared to early paired and grouped calves (16 of 21 or 76% of calves). Late paired calves had intermediate success. Individually housed calves were slower to touch novel objects, but the magnitude of the fear response did not correlate with reversal performance. We conclude that individually housed calves have learning deficits, but these deficits were not likely associated with increased
anxiety
Educação permanente de docentes: anĂĄlise crĂtica de experiĂȘncias nĂŁo sistematizadas
Are ant assemblages of Brazilian veredas characterised by location or habitat type?
Wetland areas in the Brazilian Cerrado, known as âveredasâ, represent ecosystems formed on sandy soils with high concentrations of peat, and are responsible for the recharge of aquiferous reservoirs. They are currently under threat by various human activities, most notably the clearing of vegetation for Eucalyptus plantations. Despite their ecological importance and high conservation value, little is known about the actual effects of human disturbance on the animal community. To assess how habitat within different veredas, and plantations surrounding them affect ant assemblages, we selected four independent vereda locations, two being impacted by Eucalyptus monoculture (one younger and one mature plantation) and two controls, where the wetland was surrounded by cerrado vegetation. Ant sampling was conducted in May 2010 (dry season) using three complementary methods, namely baits, pitfall traps, and hand collection, in the wetland and in the surrounding habitats. A total of 7,575 ants were sampled, belonging to seven subfamilies, 32 genera and 124 species.Ant species richness and abundance did not differ between vereda locations, but did between the habitats. When impacted by the monoculture, ant species richness and abundance decreased in wetlands, but were less affected in the cerrado habitat. Ant species composition differed between the three habitats and between vereda locations. Eucalyptus plantations had an ant species composition defined by high dominance of Pheidole sp. and Solenopsis invicta, while natural habitats were defined by Camponotus and Crematogaster species. Atta sexdens was strictly confined to native habitats of non-impacted âveredasâ. Eucalyptus monocultures require high quantities of water in the early stages, which may have caused a decrease in groundwater level in the wetland, allowing hypogeic ants such as Labidus praedator to colonise this habitat
Combined effects of low light and water stress on Jatropha curcas L. promotes shoot growth and morphological adjustment
How land use/land cover changes can affect water, flooding and sedimentation in a tropical watershed: a case study using distributed modeling in the Upper Citarum watershed, Indonesia
[EN] Human activity has produced severe LULC changes within the Upper Citarum watershed and these changes are predicted to continue in the future. With an increase in population parallel to a 141% increment in urban areas, a reduction of rice fields and the replacement of forests with cultivations have been found in the past. Accordingly, LCM model was used to forecast the LULC in 2029. A distributed model called TETIS was implemented in the Upper Citarum watershed to assess the impact of the different historical and future LULC scenarios on its water and sediment cycles. This model was calibrated and validated with different LULCs. For the implementation of the sediment sub-model, it was crucial to use the bathymetric information of the reservoir located at the catchment's outlet. Deforestation and urbanization have been shown to be the most influential factors affecting the alteration of the hydrological and sedimentological processes in the Upper Citarum watershed. The change of LULC decreases evapotranspiration and as a direct consequence, the water yield increased by 15% and 40% during the periods 1994-2014 and 2014-2029, respectively. These increments are caused by the rise of three components in the runoff: overland flow, interflow and base flow. Apart from that, these changes in LULC increased the area of non-tolerable erosion from 412 km(2) in 1994 to 499 km(2) in 2029. The mean sediment yield increased from 3.1 Mton -yr(-1) in the 1994 LULC scenario to 6.7 Mton-yr(-1) in the 2029 LULC scenario. An increment of this magnitude will be catastrophic for the operation of the Saguling Dam.This study was partially funded by the Spanish Ministry of Economy and Competitiveness through the research projects TETISMED (CGL2014-58,127-C3-3-R) and TETISCHANGE (RTI2018-093717-B-I00). The authors are also thankful to the Directorate General of Higher Education of Indonesia (DIKTI) for the Ph.D. funding of the first author.Siswanto, SY.; Francés, F. (2019). How land use/land cover changes can affect water, flooding and sedimentation in a tropical watershed: a case study using distributed modeling in the Upper Citarum watershed, Indonesia. Environmental Earth Sciences. 78(17):1-15. https://doi.org/10.1007/s12665-019-8561-0S115781
Vertical distribution of epiphytic bryophytes in Atlantic Forest fragments in northeastern Brazil
What Difference Does a Visit Make? Changes in Animal Welfare Perceptions after Interested Citizens Tour a Dairy Farm
Citizensâ concerns about farm animal welfare are often dismissed on the assumption that they are not well informed about farming practices. We conducted exploratory surveys of interested citizens (n = 50) before and after a self-guided tour of a 500-head dairy farm. âBeforeâ survey questions explored perceptions, concerns, and values about dairy cattle farming and welfare, in addition to a short knowledge-based quiz on dairy cattle husbandry. An âafterâ survey explored the extent to which these constructs shifted after the tour. Before, most participants correctly answered quiz questions about general feeding and housing practices, but scores were low on questions about specific practices such as cow-calf separation. Participants considered several elements as necessary for a âgoodâ life for dairy cattle: fresh food and water, pasture access, gentle handling, space, shelter, hygiene, fresh air and sunshine, social companions, absence of stress, health, and safety from predators. These elements reflect a diverse conception of animal welfare that incorporates values for physical and mental well-being, natural living, and humane care. The visit had a mixed effect on perceptions of whether dairy cows had a âgoodâ life, improving perceptions for a quarter of participants, worsening perceptions in a third, with no shift in the remaining participants. The visit appeared to mitigate some concerns (e.g., provision of adequate food and water, gentle humane care) while reinforcing or eliciting others (e.g., lack of pasture access, early cow-calf separation). Moreover, animal welfare-relevant values held by participants (e.g., natural living, care) appeared to play an important role in influencing perceptions of farm practices. These results suggest that education and exposure to livestock farming may resolve certain concerns, but other concerns will likely persist, especially when practices conflict with deeply held values around animal care
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