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At least 19 recordsLinked to original sources
PubMed2026

Genetic (Genomic) and Morphological Evidence Suggest That the Korean Endemic Fat Minnow (Rhynchocypris kumgangensis) and the Deogyu Population Represent Distinct Species.

Geographically disconnected populations of freshwater fishes often show ecological and genetic divergence in response to opposing selection differentials in different habitat environments, sometimes leading to the formation of ecotypes and even speciation. Nevertheless, evidence for the speciation through allopatric processes in freshwater fish systems remains scarce. Kumkang fat minnow (Rhynchocypris kumgangensis), a Korean endemic coldwater fish, has recently been suggested to diverge into a separate species (Rhynchocypris deogyuensis). However, the level of their genetic and ecological divergence remains largely unknown. We analyzed population genetic structure of R. kumgangensis together with R. deogyuensis using mitochondrial DNA (mtDNA) and eight newly developed microsatellite markers. Genetic divergence at mitogenome level was further assessed between the presumed two species. Moreover, we examined morphology between two groups by analyzing morphometric traits and also conducted geometric morphometrics on body shape. We found distinct population structure between R. kumgangensis and R. deogyuensis at both mtDNA and microsatellites. One remnant population of R. deogyuensis harbored only a single haplotype and showed a very high level of inbreeding. Comparative analysis of the mitogenomes showed approximately 2.9% divergence between R. kumgangensis and R. deogyuensis, supporting the species-level divergence. The analyses of both morphometric traits and geometric morphometrics indicated significant morphological divergence between the two species. The observed low values of length-weight relationship and condition factor for R. deogyuensis are likely to be attributed to effects of the elevated level of inbreeding and depleted genetic diversity. Overall, our combined genetic/genomic and morphological analyses suggest the considerable divergence between R. kumgangensis and R. deogyuensis, supporting the hypothesis that they are distinct species. The mechanisms underpinning how they speciate still need to be studied further in detail.

Deogyu fat minnow↗
PubMed1975

Tetralogy of Fallot: a morphometric and geometric study.

Fourteen examples of tetralogy of Fallot were studied by morphometric and geometric methods, and the findings compared with results from 10 normal hearts. The data show that in Fallot's tetralogy the conal septum is deviated anteriorly. The infundibulum, although narrow, is similar to, or of greater length than, that of the normal heart. This finding is not in agreement with the recent observations suggesting that the anomaly represents lack of growth of the pulmonary conus. Our results further demonstrate that the aorta is dextroposed in Fallot's tetralogy and that in the majority of cases absorption of the right extremity of the conoventricular flange has led to aortic-tricuspid fibrous continuity. The overall findings indicate that conal rotation has occurred in addition to anterior deviation. The data are interpreted as supporting a hypothesis of "lack of conal inversion" and conal malseptation as the morphogenetic mechanisms in tetralogy of Fallot.

Adolescent↗
PubMed2025

Tales of a Super Butterfly: Is Vanessa carye a Truly Migrant Species? Unraveling Migration Using Morphological and Genomics Approaches.

Among movement strategies, migratory behavior is particularly intriguing in insects. Home-breeding is often permanent, and return journeys can take several generations. Although migration is crucial to the ecological and evolutionary processes of the species involved, knowledge of insect migratory behavior needs to be better understood. Vanessa carye, a butterfly native to South America with a latitudinal range of ∼7,000 km, exemplifies this problem. This study analyzed samples collected across the species' range using single-nucleotide polymorphisms (SNPs) to assess population structure, genetic diversity, and geometric morphometrics to examine wing shape variation. Results indicate that V. carye forms a genetically homogeneous unit composed of only two potential populations spanning ∼5,000 km, geographically correlated with the Pacific Ocean and the Andes, maintaining constant gene flow, and with a mean heterozygosity of 5.74% (SE: ±0.048%). Geometric morphometrics detected no geographic differentiation in wing shapes and sizes across ∼7,000 km, suggesting an absence of local adaptation and indicating a conserved wing shape adapted to flight throughout the species' range. Our findings support V. carye as a migratory species with the longest migratory journey among American butterflies, revealing two migratory routes. With these approaches, we provide a consistent methodological framework for migratory studies in species with important gaps in knowledge of their natural history.

Animals↗
PubMed2024

Adaptive or non-adaptive? Cranial evolution in a radiation of miniaturized day geckos.

Lygodactylus geckos represent a well-documented radiation of miniaturized lizards with diverse life-history traits that are widely distributed in Africa, Madagascar, and South America. The group has diversified into numerous species with high levels of morphological similarity. The evolutionary processes underlying such diversification remain enigmatic, because species live in different ecological biomes, ecoregions and microhabitats, while suggesting strikingly high levels of homoplasy. To underscore this evolutionary pattern, here we explore the shape variation of skull elements (i.e., cranium, jaw and inner ear) using 3D geometric morphometrics and phylogenetic comparative methods on computed tomography scans (CT-scan) of a sample encompassing almost all recognized taxa within Lygodactylus. The results of this work show that skull and inner ear shape variation is low (i.e., there is high overlapping on the morphospace) across geographic regions, macrohabitats and lifestyles, implying extensive homoplasy. Furthermore, we also found a strong influence of allometry shaping cranial variation both at intra and interspecific levels, suggesting a major constraint underlying skull architecture, probably as a consequence of its miniaturization. The remaining variation that is not allometric is independent of phylogeny and ecological adaptation and can probably be interpreted as the result of intrinsic developmental plasticity. This, in turn, supports the interpretation that speciation in this group is largely concordant with a non-adaptive hypothesis, which results mainly from vicariant processes.

Animals↗
PubMed2026

Country specific hybridization of honey bees from lineage M.

BACKGROUND: Honey bees are essential pollinators supporting agricultural production and wild plant diversity. In evolutionary lineage M, some populations are threatened by genetic erosion caused by the widespread introduction of commercially bred queens. To assess this risk, wing images from existing and new datasets were used to assign them to four evolutionary lineages (A, C, M, and O). The new dataset consisted of 29,043 wing images representing 1,342 colony samples from ten countries. RESULTS: Overall, 63.7% of colonies belonged to lineage M, whereas 27.5% were classified as A, 7.9% as C, and 0.8% as O. Lineage M remains prevalent in unprotected populations in Portugal, Spain, and Ireland, as well as in protected populations elsewhere. In contrast, a pronounced decline was observed in unprotected populations in northeastern Poland. CONCLUSIONS: These findings reveal strong regional differences in the persistence of lineage M and underscore the need for coordinated conservation efforts throughout Europe. The data provided in this study should allow for more accurate discrimination between native and introduced phenotypes.

Apis mellifera↗
PubMed1991

Additive effects of dietary protein and energy deficiencies on diaphysis and bone tissue of rat femurs as determined by bending tests.

The present study was designed to study the effects of diets moderately restricted in protein and/or carbohydrate derived calories on morphometric parameters (geometric properties) and mechanical performance of both diaphysis (structural properties) and cortical bone tissue (material properties) from growing rat femurs, as determined by bending tests at low strain rates. Male rats aged 30 days were divided in four groups, namely NN = normal protein and energy, NPLE = normal protein and low energy, LP = low protein and normal energy, and LPLE = low protein and low energy. Each group was fed on a corresponding diet for 20 days. Both body weight and femoral length were greater in NN and lower in LL than in LE and LP groups. Geometrical and structural variables (with the exception of wall/lumen ratio) grossly paralleled changes in body weight, while material properties showed independent and less significant changes. Therefore, the assayed levels of restriction of either plastic or energetic nutrients seemed to alter bone biomechanics proportionally to the way it affected bone growth.

Animals↗
PubMedDate not supplied

Morphometric analysis of sonographic images by spatial geometric modeling.

A methodology able to derive spatial geometric models from input sequences of sonographic slices is proposed. The developed modeling procedure can be utilized to perform computer-assisted anatomic 3D analysis both on all echo space and selected subregions. The modeling procedure is mainly composed of three sequential phases: a) automatic acquisition and preprocessing of time sequences of 2D echotomograms; b) 3D reconstruction of images and computing of discrete distance maps of selected echoes according to predefined projective laws; and c) generation of a spatial geometric model of the examined object starting from the previously computed maps.

Algorithms↗
PubMed2026

Skull morphology of the extinct Tasmanian tiger suggests unique biting style.

The recently extinct thylacine (Tasmanian tiger) was the largest modern marsupial predator. It is considered a classic example of evolutionary convergence due to striking similarities with placental canids (e.g., foxes and wolves), particularly in the skull, despite ~160 million years of evolutionary separation. However, we here present geometric and linear morphometric evidence that the thylacine's cranial form arises from a mosaic of traits not represented among canids or other living mammalian carnivores. Thylacines had disproportionately large heads, tall and gracile snouts with a flared canine region, and conspicuously large infraorbital foramina. Many of these traits suggest adaptations to fast, high-impact snapping behaviour in prey capture, as proposed for several living and extinct predatorial vertebrates with similar trait combinations. The thylacine's cranial function may therefore not be inferable from observation of living mammals. However, genomic progress presents new opportunities for future insights into the evolution and development of thylacine cranial adaptation.

Animals↗
PubMed1989

A morphometrical method to estimate isoproterenol-induced infarct size in the rat.

A morphometrical method to quantify the geometrical distribution of ventricular necrosis induced in rat following the s.c. injection of isoproterenol was developed and tested. Each ventricle was divided into two portions, apical and basal, and then 10 microns thick sections of both portions were cut. Necrotic areas were detected with nitro blue tetrazolium. Total and necrotic areas were measured for each section. Thereafter, the total and necrotic volume were calculated assuming that the ventricles form a cone-like structure composed of successive frustum of a cone crowned by an apical cone. The study of volumes, necrotic and whole cardiac could be relevant for a more actual experimental comparison of the anti-ischemic drugs activity. Our results indicated that necrotic volume is unevenly distributed, especially at lower doses of isoproterenol treatment, being greater at the apical than at the basal portions of the ventricles. The importance of careful study of the ventricular apex is stressed. Potential sources of error in determining necrotic volume are discussed.

Animals↗
PubMed1989

A new method of grading malignancy of prostate carcinoma using quantitative microscopic nuclear features.

A morphometrical assessment of nuclear features and a DNA study were performed on prostate tissue specimens from 33 patients with prostate carcinoma using an image analysing computer. Six nuclear geometric variables were measured and their mean, standard deviation (SD) and standard error (SE) were calculated for each case. The data on nuclear DNA content obtained by static cytometry were processed using an algorithm which provided a DNA grade of malignancy (DNA MG). Using the stepwise multiple regression, we found a significant correlation (p less than 0.01) between the DNA MG, chosen as the dependent variable in the statistical model, and the following nuclear features in decreasing order of importance: area SD, convex perimeter SE, and the mean of maximum diameter. From the correlation coefficients of the variables an equation was built up which provided a geometric nuclear grade of malignancy (GNMG) on a morphometrical basis more closely related to the clinical stage of the tumour (r = 0.75) than the visually assessed histological grade (r = 0.68) based on the Gleason score. This new method of grading malignancy allows an objective and quantitative evaluation to be made of the biological behaviour of the tumour, as measured by the patient's clinical stage.

Cell Nucleus↗
PubMed1992

[The role of the nucleus in the mechanism of transformation of muscle after infection by Trichinella spiralis larvae. III. Morphometric analysis of the functional transformation of the muscle cell nucleus after infection].

Morphometric investigations (using the convergence analysis method) of geometric parameters of nuclei and nucleoli of transformed muscle cells were carried in mice 15 days, 30 days and 6 month after infection with T. spiralis larvae. The analysis showed the largest increase of investigated the parameters of 15th day after the infection. The results of morphometric analysis are in agreement with the morphologic, ultrastructural and histochemical observations (published in I and II part) as for as functional changes of muscle cells in various stages of trichinellosis are concerned.

Animals↗
PubMed1988

Morphometric analysis of the thoracolumbar and lumbar pedicles, anatomo-radiologic study.

The geometric properties of 380 vertebral pedicles, ranging from T6 to L5, were analysed. Measurement were made directly from the specimens as well as from roentgenograms. The parameters considered were the horizontal and vertical pedicle diameters, pedicle angles in the transverse and sagittal planes, and the transverse and anteroposterior widths of the spinal canal and vertebral body. In addition, the length of the pedicle and the length of the pedicle including the vertebral body to the anterior cortex were measured along the pedicle axis and in a line parallel to the midline of the vertebral body. The smallest horizontal and vertical pedicle diameters were found at vertebral levels from T6 to T10. The correlation between pedicle widths and screw dimensions is obvious. In the transverse plane, the pedicle angle diverged from the vertebral body at all levels, except at T12. In the sagittal plane, the pedicles were angled cephalad from T6 to L3 and slightly caudally at L5. Knowledge of the length of the pedicle to the anterior vertebral body cortex is very important for safe screw purchase. At all levels, with the exception of T12, this length was found to be significantly greater along the pedicle axis than along a line parallel to the midline of the vertebral body.

Adult↗
PubMedDate not supplied

A geometric model for measurement of surface distance, surface area, and volume from tomographic images.

Surface area and volume are essential measurements in the morphometric assessment of anatomical structures. New algorithms were developed to measure (1) distance along a curve, (2) surface area, and (3) volume using data extracted from tomographic images as a geometrical surface model. The model is a list of coordinates and normal vectors for each voxel or point gathered from the surface of a selected object. The resulting surface-based pointlist is also used for high-speed rendering of surfaces. Differential arclength and surface area are measured with high numeric precision by using the absolute value of the maximum component of the unit normal vector (MUNC) to approximate their values. These differential values are summed to measure distance along a curve and surface area. A discrete form of the Divergence theorem, also using the MUNC, is used to calculate volume. The intrinsic accuracy of the measurement algorithms was evaluated using computer generated pointlists of circles, ellipses, spheres, and ellipsoids. Compared to standard measurement techniques, the new algorithms provided the greatest accuracy and least shape-related bias for measurement of distance, surface area, and volume. Feasibility of using the new algorithms to measure physical objects was tested with CT images of spherical, egg-shaped, and irregular shaped objects. The Dividing Cubes algorithm was used to segment and create pointlists from the CT data. Volume and surface area measurements from CT data compared extremely well with reference values for most objects tested (errors less than 2%).

Algorithms↗
PubMed1990

Image analysis of Nissl-stained neuronal perikarya in the primary visual cortex of the rat: automatic detection and segmentation of neuronal profiles with nuclei and nucleoli.

An image analysing procedure for the morphometric characterization of cortical neurons in Nissl-stained brain sections is described. It consists of the automatic detection of cellular profiles and their compartments: cytoplasm, nucleus and nucleolus. The algorithm was designed to cope with the large morphological spectrum of cortical perikarya (e.g. geometrical properties of perikarya, staining intensities of cell compartments and nucleo-plasmic area-ratio) including pyramidal (Golgi-category I) and non-pyramidal (Golgi-category II) neurons. Clusters of cells were separated and non-neuronal structures (e.g. glia, endothelial cells) as well as tangential, non-nucleolated sections through neuronal perikarya recognized and excluded from further analysis without requiring interactive procedures. The performance of the profile recognition procedure was evaluated using 426 nucleolated and non-nucleolated profiles of different types of neurons in the primary visual cortex of the rat. Nucleolated profiles were recognized as such with a 91% accuracy, non-nucleolated profiles were rejected correctly in 90% of cases. After automatic segmentation and selection of nucleolated neuronal profiles from the microscopic field, a large set of quantitative morphological features including geometrical, densitometrical and textural parameters can be measured using high power light microscopy. This permits quantitative morphometric characterization of different neuronal types. This procedure is the first part of a system for the automatic classification of Nissl-stained cortical neurons.

Algorithms↗
PubMed1975

Morphometric estimation of brain swelling and atrophy.

A morphometric method was presented to estimate brain swelling or atrophy from the geometric characteristics of the pontine cross section. The ratio of the area (A) to the perimeter squared (L2) was termed "area factor" (f) and used as a factor indicating circularity. Normal standards for the net cross-sectional area (Ap) and the area factor (f) of the pons measured on paraffin sections were 3.43 approximately 4.87 cm2 and 0.0684 approximately 0.0740, respectively. Values exceeding these ranges suggested brain edema. The pontine area factors (f) of the control cases under 60 years of age were less spread out than Ap, whereas they exhibited larger individual variations over that age presumably as a result of varying involution of the brain. A close correlation was found between Ap and water content of the cerebral white matter, except in pontine hemorrhage. The correlation was particularly marked in the group of cerebral diseases other than stroke. The longitudinal length of the basis pontis (lp) was essentially the same in the normal brain and even in the stoke group excluding pontine and cerebellar hemorrhage. In severe brain swelling the pontine longitudinal length was rather reduced.

Adult↗
PubMed1989

Atherometric system: morphometric standardized methodology to study atherosclerosis and its consequences.

A group of strong mutual dependent variables, obtained by measuring some morphological and pathomorphological characteristics of an artery affected by atherosclerosis (arterial variables) and its organ-related damage (organ-related variables DRV), yield a suitable methodology to study and characterize this disease and its further severe consequences. Applying some biophysical (rheological, geometrical, and haemodynamical) and mathematical reasonings to those measurements an atherometric system AS is derived. It is a new standardized morphometric methodology which allows, by the use of their variables, the development of useful pathomorphological, pathogenetical, statistical, and epidemiological investigations. The variables of the AS are divided into 1. descriptives and 2. weighting indices WI to estimate the severity of atherosclerosis. The descriptive arterial variables were obtained from each type of atherosclerotic lesion AL, fatty streak, fibrous plaque, and severe (complicated and calcified) plaques, latter normalize and further represented in a 3-dimensional vector, in order to conserve all the analytical information of each type of AL. Their WI are obstruction, stenosis, and benignity. The descriptives DRV (estimated volumes) and their respectively derived WI, are in relation with the pathological conditions: fibrosis, necrosis, haemoŕrhage, total damage, and their counterpart non-affected (sufficient) variables. A digitizer coupled to a personal computer LTEL (Cuba) to obtain the primary data was used. All data were processed in a computer EC-1040 (G.D.R.) using the statistical commercial package "SPSS" for scientific analysis.

Aorta, Abdominal↗
PubMed1989

Effect of swimming on bone growth and development in young rats.

The effect of chronic swimming on bone modelling was studied. Forty female Sabra rats (5 weeks old) were randomly assigned to the following experimental groups: 30 rats were trained to swim (water bath 35 +/- 1 degree C, one h daily, five times a week) for 20 weeks--20 of them loaded with lead weights (1% body weight) while the rest (10 animals) swam load free. Ten sedentary rats matched for age and weight served as controls. At the end of the twenty-week swimming period, all rats were sacrificed, both humeri bones were dissected and prepared for the following examinations: morphometric, bone density (BD), bone mineral content (BMC), compression tests and cross-sectional geometrical parameters, histomorphometry and biochemical analysis of minerals (Ca, Pi, Mg, Zn). All measured parameters were found to be significantly higher (P less than 0.05) in the swimming rats irrespective of load, as compared with the controls. Bone weight was higher by 19%, bone volume by 11%, bone length by 2.8%, cortical area by 16%, BD by 7% and BMC by 15%. The compression breaking force at the distal shaft of the humerus was higher by 24% in the trained group, while the ultimate compressive stress was not significantly different. Maximal and minimal moment of inertia at the distal diaphysis were 33.4 and 40% higher, respectively, for the swimming groups than the controls. Ca, Pi, Mg and Zn levels per total humeral bone were significantly higher in the exercising rats. The histomorphometry and cross-sectional data emphasize longitudinal and transversal growth. These data indicate that swimming exercise exerts a positive effect on bone growth and development in young rats.

Animals↗
PubMed1992

[Aging of the arterial system].

The high-pressure systemic arterial network plays a major physiological role as it buffers the impact of the blood flow wave generated by the left ventricle and transforms it into a more continuous flow in the peripheral arterioles. In ageing processes unrelated to hypertensive or vascular disease the structural properties of the arterial network are significantly altered. The collagen, elastin and smooth muscle contents of the tunica media and the geometrical arrangement of arterial wall components are constantly modified according to the subject's age. These morphometric changes are responsible for changes in the mechanical properties of the arterial walls leading to rigidity. An increase in caliber of the arterial lumen has been found in all studies; it partially compensates for the effects of arterial wall rigidity on vascular compliance, thereby limiting the haemodynamic and functional changes that occur in blood circulation.

Adult↗