COVID-19 geoviz for spatio-temporal structures detection

The spread of COVID-19 has motivated a wide interest in visualization tools to represent the pandemic’s spatio-temporal evolution. This tools usually rely on dashboard environments which depict COVID-19 data as temporal series related to different indicators (number of cases, deaths) calculated for several spatial entities at different scales (countries or regions). In these tools, diagrams (line charts or histograms) display the temporal component of data, and 2D cartographic representations display the spatial distribution of data at one moment in time. In this paper, we aim at proposing novel visualization designs in order to help medical experts to detect spatio-temporal structures such as clusters of cases and spatial axes of propagation of the epidemic, through a visual analysis of detailed COVID-19 event data. In this context, we investigate and revisit two visualizations, one based on the Growth Ring Map technique and the other based on the space-time cube applied on a spatial hexagonal grid. We assess the potential of these visualizations for the visual analysis of COVID-19 event data, through two proofs of concept using synthetic cases data and web-based prototypes. The Grow Ring Map visualization appears to facilitate the identification of clusters and propagation axes in the cases distribution, while the space-time cube appears to be suited for the identification of local temporal trends.

THE EFFECT OF CLIMATE ON THE RADIAL GROWTH OF SCOTS PINE (PINUS SYLVESTRIS L.) IN A COASTAL MIXED STAND IN KAPISUYU, BARTIN, TURKEY

Scots pine is geographically the most widespread pine species in the world, and it shows different growth responses to climate and environmental factors in diverse ecological sites. We studied both the stand dynamics and climate-growth relationships of Scots pine in isolated coastal stand (recently found) in the Western Black Sea Region of Turkey. The homogeneity index of this stand has varied between 1.92-3.56. In growth-ring analyses, after cross-dating of individual chronologies, COFECHA and ARSTAN software were used respectively for chronology quality control and standardization (detrend). In this way, a 58-year-long chronology (1959-2016) of Scots pine was constructed. In addition, DENDROCLIM software was used for investigating Scots pine’s radial growth-climate relationships. Mean sensitivity changed from 0.163 to 0.331, with a mean of 0.183. Mean correlation among trees and signal to noise ratio were 0.389 and 7.012 respectively. In terms of the effect of precipitation on the radial growth of Scots pine in this site, the correlation coefficients were 0.43 (p<0.05) for December of the previous year and 0.41 (p<0.05) for July of the current year. For all the other months, precipitation had a non-significant effect. As for the maximum and mean air temperature, the correlation coefficients were 0.36 (p<0.05) and 0.40 (p<0.05) for February, and 0.40 (p<0.05) and 0.42 (p<0.05) for March, respectively. However, on the radial growth, while the maximum temperature in August had a negative effect (r= -0.26; p<0.05), minimum temperatures in February, March and July had a positive effect (r= 0.39, 0.40 and 0.34 respectively; p<0.05). It means while higher rains in July and higher temperatures in the late winter-early spring have caused the wider growth rings, the narrower growth rings have been formed in the years with higher maximum temperatures in August in the isolated coastal site of Scots pine.

Mosaic, block-face microscopy for measuring cell dimensions, cell collapse, and spatial relationships in wood

A conventional stereo light microscope was used to image polished wood surfaces at cellular resolution over size scales of the growth ring or larger. Bandpass filtering and local area contrast enhancement were used to aid automatic image thresholding and binarisation. An estimate for the location and proportion of cell collapse was introduced based on the distance between uncollapsed cell lumens. Additionally, spatial associations between vessels were determined using a Euclidean distance transform. The analysis of pith to bark cores provided sufficient detail to show significant intra and inter-annual trends in Pinus radiata tracheid dimensions (wall thickness, wall area, and radial widths). These trends were consistent with expectations and in agreement with the literature. Measured cell dimensions may be influenced by cell collapse and deformation as a result of drying. The analysis of air, kiln and oven-dried Eucalyptus nitens showed that cell collapse was highly variable but generally more prominent in the outer third of growth rings. There were significant changes in vessel shape across the growth rings and vessel area was significantly reduced by drying. The technique provides an intermediate step between detailed microscopy and macroscopic imaging that allows spatial analysis at the wood cell level.

Growth Ring Orientation Effects in Transverse Softwood Fracture

In this study, the fracture mechanics of eastern spruce were characterized in relation to end-grain orientation. Compact tension-type specimens with small pre-formed cracks were prepared such that grain angle varied relative to the load axis. Specimens were loaded under crack mouth opening displacement (CMOD) control as to maintain stable crack growth. Specimen fracture was characterized using both R-curve and bulk fracture energy approaches. The results showed that under a RT grain orientation, as well as grain deviations up to about 40∘, cracks will follow a path of least resistance in an earlywood region. As the grain angle exceeds 40∘, the crack will initially move macroscopically in the direction of maximum strain energy release rate, which extends in the direction of the pre-crack, but locally meanders through earlywood and latewood regions before settling once again in an earlywood region. At 45∘, however, the macroscopic crack takes a turn and follows a straight radial path. The results further show that RT fracture is macroscopically stable, while TR fracture is unstable. None of the end-grain fracture orientations showed rising R-curve behavior, suggesting that there is not a traditional fracture process zone in this orientation.

GROWTH CIRCLE PATTERNS IN THE OTOLITH OF THE GRAY FISH (Osteochilus melanopleurus) FROM THE SIAK AND KAMPAR RIVERS

Osteochilus melanopleurus can be found in the Siak and Kampar Rivers. The Kampar Rivers waters are better than that of the Siak River and it affects the growth of the fish. The growth pattern is reflected in the pattern of otolith growth rings. The research aims to understand the pattern of otolith growth rings of the O. melanopleurus from both rivers has been conducted from January to February 2021. There were 55 fishes captured (28 males and 27 females). The otolith was taken using tweezers and shaved manually using a soft grindstone. The dark growth ring pattern was investigated using a binocular microscope. Results showed the size of fish captured was 220 to 360 mm from Siak River and 310 to 370 mm from Kampar River. In the fish with the same standard length, the size of the otolith from the Siak River is heavier and longer than that of the Kampar River, which means that fish growth from the Kampar River is better than that of the Siak River. The length of an otolith from Siak River ranged from 1.875 – 3.275 mm, the width was ranged from 1.575–2.75 mm and the weight of otolith was 0.0039 – 0.0098 g, while the length of an otolith from Kampar River ranged from 2.375–3.275 mm, the width was ranged from 1.85–2.575 mm and the weight of otolith was 0.0042 –0.0076 g. The maximum number of the dark ring in the otolith from the Siak River was 4 and Kampar River was 2. The distance between the nucleus and the first dark ring of fish from both rivers was varied from 0.1–0.525 mm, and there was no special pattern. This fact indicates that the first dark ring was formed individually and they were not formed by a periodical incidents during the fish life