Basis Of Morphometry Research Articles

Активность геоморфологических процессов на склонах речных долин в условиях газогидротермальных проявлений (по разновременным снимкам и ЦМР)

In the geothermal zones of modern volcanic areas, geomorphological processes are considerably influenced by numerous gas-hydrothermal outcrops, which may dramatically change rock properties and, consequently, denudation peculiarities and rates. The activity of processes on the slopes of Kamchatka river valleys under conditions of gas-hydrothermal occurrences (Geysernaya river valley) and without them (Shumnaya river valley) has been studied and comparatively analyzed. For the most correct separation and comparison of the valley regions which differ in the conditions of development of the modern slope processes, ArcticDEM digital elevation model and a series of morphometric maps (slope steepness, exposition, elementary watersheds) built on its basis, as well as geological maps, results of thermal survey of different detail level and field observation data were used. Interpretation of high spatial resolution images (0.5–5 m) for the mid-1960s (KeyHole-4 CORONA) and modern images for the period 2016–2021 from different survey systems was carried out. As a result of decoding, quantitative assessments of slope conditions within the selected valley fragments selected on the basis of morphometry were obtained for two time slices separated by 55 years. It is established that under conditions of gas-hydrothermal manifestations development, the share of the total area of the slope’s sections affected by active processes, with other conditions being equal, is significantly higher than the same in the areas without gas-hydrotherms. For 55 years the share of the areas with slope processes activation on the background areas practically has not changed, and on the territories affected by gas-hydrothermal influence has increased by 10–17 %. The conducted studies allow us to conclude that gas-hydrothermal manifestations are the most powerful driver of modern geomorphological processes on slopes in the studied region.

Authenticating wild Piper species (peppers) originating from islands in the Indian Ocean on the basis of morphological, genetic and chemical characteristics

As demand for pepper is rising to unprecedented levels, gaps in our knowledge are underlined by our inability to reliably distinguish the different species, in particular in the south-western Indian Ocean; this hampers the possibility of developing their economic potential and protect them efficiently. The aim of this study was to characterise two species of Piper (piperaceae) from Madagascar and one from Réunion Island via a multidisciplinary approach combining botany, genetics and chemistry and to propose authentication keys. Morphometric analyses were carried out on 22 quantitative and qualitative descriptors of the leaf and infructescence. Genetic analyses were conducted through DNA extraction, amplification by PCR and sequencing. Chemical analyses used spectrophotometric and chromatographic methods to determine concentrations in piperine and essential oil and describe the chemotypes of the sampled individuals. Our tri-disciplinary approach showed that the three peppers studied are very different from Piper nigrum L. Réunionese Piper borbonense and M3 Malagasy pepper clearly differ from the M1 Malagasy morphotype. Piper borbonense and M3 pepper appear to be closely related; a distinction could possibly be made at the variety (var.) or form (fa.) level on the basis of morphometry and according to piperine content for chemistry.

Growth of segment parameters and a morphological classification for children between 15 and 36 months

This study is part of a research program that aims at a better understanding of the influence of individual morphological differences and physical growth on development of independent walking in toddlers. As morphometric and segment inertial parameters for toddlers aged between 15 and 36 months are indispensable for the mechanical analyses inherent to this purpose, parameter data were collected. The provided dataset of morphological and segment inertial parameters is a valuable tool for locomotor biomechanical modelling. Analysis of the parameter data showed that there are substantial changes of most segment inertial parameters across body length and body mass. In addition, a classification system was developed to categorize toddlers on the basis of morphometry, reflecting the segment inertial constitution of the child. A principal components analysis (PCA) was applied to define the variance in physique between the children. PCA resulted in three newly composed variables: the 'Axis of chubbiness', the 'Axis of allometric growth' and the 'Axis of relative limb length'. The three axes are plotted against each other, resulting in eight morphological classes. With this classification the morphotype of toddlers between 15 and 36 months can be specified and used for further research on their walking patterns.

Identification of Mapped Ice-Margin Positions in Western New York from Digital Terrain-Analysis and Soil Databases

Geographic Information Systems (GIS) are rarely applied to problems associated with Wisconsinan ice-margins. This study identifies inconsistencies in ice extent in the Salamanca Re-entrant in western New York as mapped using soil properties and surficial geology. In essence, previous studies have revealed a zone of disagreement between those areas that were clearly glaciated and those that were not. This study uses a raster-based approach to extract the soil pH, silt, and clay contents from digital soil databases; and the morphometric parameters of elevation, slope, terrain ruggedness, and planform and profile curvature from mosaiced 10-m digital elevation models. Two-way ANOVA indicates a close correspondence between the zone of disagreement and the glaciated area when soil information is used; however on the basis of morphometry, the area of disagreement is analogous to the unglaciated terrain. These results highlight both previous difficulties and the source of the mapped differences, suggesting that a GIS analysis of former ice margins is a productive preliminary step to their precise delineation.

MORPHOLOGICAL DISCRIMINATION OF NOTURUS STIGMOSUS AND N. ELEUTHERUS (SILURIFORMES: ICTALURIDAE) IN THE OHIO RIVER BASIN

In the Ohio River basin, the northern madtom, Noturus stigmosus Taylor, is morphologically similar to and sympatric with the mountain madtom, Noturus eleutherus Jordan. Although recognized as distinct sympatric (and syntopic) species, N. stigmosus and N. eleutherus are difficult to distinguish in streams where they are associated, based on previously defined characters. Sheared principal component analysis (PCA) of morphometric data revealed characters that more effectively differentiate the two species. Noturus stigmosus differs from N. eleutherus in having longer pectoral fins and spines, a longer dorsal fin and spine, a shorter and higher adipose fin, and a longer first dorsal saddle. As juveniles (20-30 mm standard length), N. eleutherus more closely resembles N. stigmosus on the basis of morphometry and pigmentation, but differs from the former in lacking a distinct dark adipose blotch. Meristic comparisons indicate that the two species differ most consistently at sizes > 30 mm SL in the numbers of caudal fin rays (usually > 48 in N. stigmosus vs. < 47 in N. eleutherus) and preoperculomandibular (POM) pores (modally 11 in N. stigmosus vs. 10 in N. eleutherus).

The fine structure of stumps of transected nerve fibers in subserial sections

The proximal stumps of five rat sciatic fibers, transected 72 hr earlier, were reconstructed on the basis of morphometry in subserial electron micrographs of isolated fibers. Three fibers showed extensive axon sprouting; 2 had no sprouts but were excessively swollen. The total volume of axoplasm in the axon swellings approximated the volume of axoplasm in all sprouts of any given fiber. Axonal swelling therefore may ensue when sprouting is frustrated. Axon sprouts originated mostly at nodes from where they descended or ascended along the fiber, running within its lamina basalis. Sprouting began soon after injury, usually within the first day. Counts of microtubules showed an approximately 10-fold increase in the total number of tubules per fiber toward the injured end. Schwann cells showed asymmetric hypertrophy, having distinctly more cytoplasm distally than proximally to the nucleus., The increase in Schwannian cytoplasm occurred roughly pari-passu with the increases in axoplasm. Hypertrophy of Schwann cells was associated with cytoplasmic islands or strands having an extremely variable content of organelles. Such islands of Schwannian cytoplasm may be confused with axon sprouts. Retraction of the myelin sheaths at nodes results in fiber profiles suggestive of partial demyelination. Retraction of nodal pseudopodia produces redundant loops of lamina basalis. Migratory cells are seen outside the fibers or underneath their lamina basalis having a preference for nodal regions or for the fiber stump. They behave differently toward axon or myelin: they encompass axon sprouts as do immature Schwann cells; simultaneously the same cell may invade myelin sheaths like a macrophage. Other curious overlaps of degenerative and regenerative phenomena were noted, including an axon sprout tunneling through the lumen of the sequester of the myelin sheath of its parent axon.

Morphometric Differences among Four Biotypes of Ostrinia nubilalis (Lepidoptera: Pyralidae)1

The morphometric differences among 4 biotypes of the European corn borer, Ostrinia nubilalis (Hubner), were studied on the basis of 5 characters: (1) length of Cu1 of the hind wing, (2) width of scutellum I, (3) length of basisternum II, (4) length of tegula, and (5) length of tibia III. The 4 biotypes were from Minnesota, Iowa, Missouri, and Ohio. The Minnesota biotype is distinctly different from the Missouri biotype, and the Iowa biotype is intermediate. The Ohio biotype is more similar to the Missouri biotype than to the Minnesota and Iowa biotypes. These relations on the basis of morphometry are parallel to those in ecological characteristics, namely, survival and diapause. The results suggest that the biotypes of this insect have evolved beyond the stage of ecological and physiological differentiation.