Laser Speckle Imaging: A Novel Method for Detecting Dental Erosion

Erosion is a highly prevalent condition known as a non-carious lesion that causes progressive tooth wear due to chemical processes that do not involve the action of bacteria. Speckle images proved sensitive to even minimal mineral loss from the enamel. The aim of the present study was to investigate the use of laser speckle imaging analysis in the spatial domain to quantify shifts in the microstructure of the tooth surface in an erosion model. 32 fragments of the vestibular surface of bovine incisors were divided in for groups (10 min, 20 min. 30 min and 40 min of acid etching) immersed in a cola-based beverage (pH approximately 2.5) twice a day during 7 days to create an artificial erosion. By analyzing the laser speckle contrast map (LASCA) in the eroded region compared to the sound it was observed that the LASCA map shifts, proportionally to the acid each duration, by: 18%; 23%; 39% and 44% for the 10 min; 20 min; 30 min and 40 min groups, respectively. To the best of our knowledge, this is the first study to demonstrate the correlation between speckle patterns and erosion progression.     

Ecological specialization and niche overlap of subterranean rodents inferred from DNA metabarcoding diet analysis

Knowledge of how animal species use food resources available in the environment can increase our understanding of many ecological processes. However, obtaining this information using traditional methods is difficult for species feeding on a large variety of food items in highly diverse environments. We amplified the DNA of plants for 306 scat and 40 soil samples, and applied an environmental DNA metabarcoding approach to investigate food preferences, degree of diet specialization and diet overlap of seven herbivore rodent species of the genus Ctenomys distributed in southern and midwestern Brazil. The metabarcoding approach revealed that these species consume more than 60% of the plant families recovered in soil samples, indicating generalist feeding habits of ctenomyids. The family Poaceae was the most common food resource retrieved in scats of all species as well in soil samples. Niche overlap analysis indicated high overlap in the plant families and molecular operational taxonomic units consumed, mainly among the southern species. Interspecific differences in diet composition were influenced, among other factors, by the availability of resources in the environment. In addition, our results provide support for the hypothesis that the allopatric distributions of ctenomyids allow them to exploit the same range of resources when available, possibly because of the absence of interspecific competition.     

Fishers’ ecological knowledge on the reproduction of fish and shrimp in a subtropical coastal ecosystem

Hydrobiologia - Fishers’ ecological knowledge (FEK) has contributed to a better understanding about the reproduction of fishery resources, especially where biological data are scarce or...     

Body movements during the off-ice execution of back spins in figure skating

Using an optoelectronic motion capture system, we quantitatively assessed the arrangement of body segments and the displacement of the horizontal projection of the center of mass (CM) in seven skaters performing off-ice back spins on a rotating device (spinner). The position of the CM at the beginning of the spins was not a determining factor, but its rapid stabilization towards the center of the spinner, together with the achievement of a stable arrangement of trunk and limbs, was crucial to get the dynamic equilibrium, necessary for a lasting performance. At full spinning, however, there was an indicative variety of individual body postures. A final deceleration, associable with the loss of body equilibrium, was detected in the last spin of most of skaters.In conclusion, the current investigation demonstrated that the off-ice execution of back spin, a critical movement of ice skating, can be measured in laboratory, thus providing quantitative information to both the skaters and the coaches. The analysis is not invasive, and it may be proposed also for longitudinal evaluations of skating and postural training.     

Azione Della Luce Sull'Assorbimento,L'Utilizzazione Ed Il Trasporto Dei Glucidi

Abstract

Effect of light on the uptake, utilization and transport of sugars. — The effect of light on the uptake of saccharides, their incorporation into insoluble fractions and their transport by green tissues has been studied under conditions of complete inhibition of the photosynthetic assimilation of CO₂. Such conditions were obtained by means of either an inhibitor of O₂ evolution (CMU), or by running the experiment in CO₂-free atmosphere. When Wolffia arryza plants are incubated with glucose-C¹⁴, light stimulates the incorporation of C¹⁴ into all fractions examined, and especially into the polysaccharides, like cellulose,' which are synthesized outside the chloroplasts.

Experiments with Elodea canadensis have shown that light stimulates the transport of glucose-C¹⁴ from the leaves to the stems, independently of the presence or absence of CO₂ assimilation.

These experiments support the hypothesis that ATP synthesyzed in the light by chloroplasts can be utilized by green cells as an energy source for biosyntheses outside the plastids, as well as for other types of biological work, such as active uptake and transport.     

Road-associated edge effects in Amazonia change termite community composition by modifying environmental conditions

Roads and road-building are among the most important environmental impacts on forests near urban areas, but their effects on ecosystem processes and species distributions remain poorly known. Termites are the primary decomposer organisms in tropical forests and their spatial distribution is strongly affected by vegetation and soil structure. We studied the impacts of road construction on termite community structure in an Amazonian forest fragment near Manaus, Brazil. One leading question was whether the fragment under study was large enough to maintain the termite species pool present in nearby continuous forests. We also asked how soil moisture and canopy openness varied with proximity to roads, and whether these changes were associated with changes in termite species richness and composition in the fragment. While the forest fragment had a termite composition very similar to that of continuous forests, roads caused important changes in soil moisture and canopy openness, especially when close to forest edges. At distances of up to 81 m from roads, changes in soil moisture were significantly related to changes in termite species composition, but there was no correlation between canopy openness and species richness or composition. These results suggest that fragmentation caused by roads impacts termites in a different and less damaging manner than fragmentation caused by other kinds of degradation, and that even fragments bisected by roads can support very diverse communities and even undescribed taxa of termites. We conclude that a buffer zone should be established for conservation purposes in the reserves surrounded by roads.