Morphological Variability Research Articles

Factors Influencing Non-Surgical Root Canal Treatment Outcomes in Mandibular Second Molars: A Retrospective Cone-Beam Computed Tomography Analysis.

Background/Objectives: This study aimed to investigate the influence of the root canal morphology and various treatment variables on the outcomes of root canal treatments (RCTs) in mandibular second molars, assessed through cone-beam computed tomography (CBCT) imaging. Methods: A total of 150 CBCT images were examined, comprising 100 cases of persistent endodontic infections and 50 of previously treated root canals with normal apices in the mandibular second molars. CBCT was utilized to evaluate the root canal configuration, the radiographic quality of coronal restorations and treated canal systems, and the presence of periapical lesions. Statistical analyses were performed to explore the correlations between these factors. Results: The presence of a C-shaped root canal configuration did not demonstrate a significant correlation with periapical lesions (p = 0.05). Factors influencing endodontic treatment outcomes included missing canals (p = 0.018), underfilling or overfilling (p = 0.045), and inadequate coronal restoration (p = 0.006). Missing a canal was identified as the variable most significantly associated with periapical lesions (OR = 3.103). Inhomogeneous root canal obturation was more commonly observed in C-shaped root canals (p < 0.001). Conclusions: Regardless of the root canal morphology of mandibular second molars, successful RCT depends on thorough disinfection to eliminate any untreated canals, precise three-dimensional filling of the canals at the correct working length, and a securely sealed coronal restoration to prevent leakage.

Hydrothermal sulfidation of biogenic magnetite produces framboid-like pyrite

Biogenic magnetite is a potential biosignature for microbial iron cycling in hydrothermal sulfide systems, critical environments for unraveling the emergence and early evolution of life. However, the preservation potential of biogenic magnetite under hydrothermal conditions is poorly understood. Here, we show that the hydrothermal sulfidation of abiogenic and biogenic magnetite (sulfide/iron = 4, 80 °C) yields pyrite with various distinct morphologies, including framboid-like spheroids. We demonstrate that the variability in pyrite morphologies resulted from the modulation of pyritization rates by interrelated effects between organic matter and elemental sulfur (crystalline or colloidal). Notably, framboid-like pyrite, commonly considered a potential fingerprint of microbial sulfur cycling, was exclusively produced from the hydrothermal sulfidation of biogenic (i.e., organic matter-associated) magnetite produced by iron-cycling microorganisms. Thus, framboid-like pyrite can additionally be a taphonomic fingerprint of microbial iron cycling, enabling a better understanding of the evolution of Earth’s biosphere in deep time.

Morphological and biochemical variation of Ajuga chamaecistus Ging. ex Benth. in different habitats of Markazi province in the center of Iran

BackgroundMedicinal plants, such as Ajuga chamaecistus Ging. ex Benth. are a natural and available source of treatment for a wide range of diseases. The objective of the present study was to assess the morphological and biochemical variation of 70 accessions of this species collected from seven geographical areas of Markazi province in the center of Iran.ResultsThe measured traits exhibited considerable variability across the populations. Positive correlations were observed between antioxidant activity and total phenolic content, as well as total flavonoid content. Principal component analysis showed six components explaining 72.15% of the total variance, and the PC1 explained 20.68% of the total variance. The Ward dendrogram based on morphological variables identified two main clusters. Morphological analysis of A. chamaecistus showed a high variation between qualitative and quantitative traits that help the breeders for selecting the desired genotypes. The accessions collected from the Robat-Mil area showed the highest values for the recorded morphological characteristics. Also, the populations of Robat-Mil, Hassanabad, and Khaneh-Miran were characterized by high values of total phenolic content, total flavonoid content, and antioxidant activity, which can be used in various industries, including pharmaceuticals, cosmetics, and food.ConclusionsOverall, the present results showed that the best place for the growth of A. chamaecistus with the production of significant contents of phenol and flavonoid is in Robat-Mil area.

Morphological characterization and molecular marker-assisted selection for resistance to Tobacco mosaic virus (TMV) and Tomato spotted wilt virus (TSWV) in S2 population of capia pepper (Capsicum annuum L.)

Morphological characterization and molecular marker-assisted selection for resistance to Tobacco mosaic virus (TMV) and Tomato spotted wilt virus (TSWV) in S2 population of capia pepper (Capsicum annuum L.)

Bone collagen tensile properties of the aging human proximal femur

Despite the dominant role of bone mass in osteoporotic fractures, aging bone tissue properties must be thoroughly understood to improve osteoporosis management. In this context, collagen content and integrity are considered important factors, although limited research has been conducted on the tensile behavior of demineralized compact bone in relation to its porosity and elastic properties in the native mineralized state. Therefore, this study aims (i) at examining the age-dependency of mineralized bone and collagen micromechanical properties; (ii) to test whether, and if so to which extent, collagen properties contribute to mineralized bone mechanical properties.Two cylindrical cortical bone samples from fresh frozen human anatomic donor material were extracted from 80 proximal diaphyseal sections from a cohort of 24 female and 19 male donors (57 to 96 years at death). One sample per section was tested in uniaxial tension under hydrated conditions. First, the native sample was tested elastically (0.25 % strain), and after demineralization, up to failure. Morphology and composition of the second specimen was assessed using micro-computed tomography, Raman spectroscopy, and gravimetric methods. Simple and multiple linear regression were employed to relate morphological, compositional, and mechanical variables with age and sex.Macro-tensile properties revealed that only elastic modulus of native samples was age dependent whereas apparent elastic modulus was sex dependent (p < 0.01). Compositional and morphological analysis detected a weak but significant age and sex dependency of relative mineral weight (r = −0.24, p < 0.05) and collagen disorder ratio (I∼1670/I∼1640, r = 0.25, p < 0.05) and a strong sex dependency of bone volume fraction while generally showing consistent results in mineral content assessment. Young's modulus of demineralized bone was significantly related to tissue mineral density and Young's modulus of native bone.The results indicate that mechanical properties of the organic phase, that include collagen and non-collagenous proteins, are independent of donor age. The observed reduction in relative mineral weight and corresponding overall stiffer response of the collagen network may be caused by a reduced number of mineral-collagen connections and a lack of extrafibrillar and intrafibrillar mineralization that induces a loss of waviness and a collagen fiber pre-stretch.

Diversity of the genus Chondrilla L. (Asteraceae) in Eastern Europe

Abstract. Kashin AS, Parkhomenko AS, Kondratieva AO, Kritskaya TA, Bogoslov AV, Shilova IV. 2024. Diversity of the genus Chondrilla L. (Asteraceae) in Eastern Europe. Biodiversitas 25: 1901-1910. The genus Chondrilla (Asteraceae) has a complex taxonomic structure due to widespread apomictic reproduction. This study aimed to identify the variability and clarify the status of Chondrilla species growing in Eastern Europe (European Russia and Western Kazakhstan). The study of morphological variability in Chondrilla species was assessed using 28 morphometric parameters. Moreover, 840 specimens from 28 populations of 8 Chondrilla species from Eastern Europe were analyzed. Principal Component Analysis (PCA), Nonmetric Multi-Dimensional Scaling (NMDS), recursive decomposition, and random forest algorithm were used for analysis. The ordination methods divided the studied samples into two groups: the first group included samples of C. ambigua and C. pauciflora, and the second group included all remaining samples. Following the resulting binary trees, obtained by recursive decomposition method and the random forest algorithm, a determination key was compiled for the Chondrilla species of Eastern Europe. The high level of morphological variation in Chondrilla and its distribution characteristics revealed in this study by numerical taxonomy and recursive decomposition methods, along with our previous studies results, show that only C. ambigua is a morphologically and genetically well-separated species, including C. pauciflora as a triploid cytotype; C. canescens, C. graminea, C. latifolia and C. juncea are synonyms with the priority name C. juncea and should be considered as subspecies; and C. brevirostris and C. laticoronata are hybrids with C. ambigua as maternal parent.

Lithic projectile technology in the western Late Epigravettian: The case study of north-eastern Italy

Projectile implements are one of the most frequent transformed lithic blanks within the Upper Paleolithic assemblages. Since the first taxonomic studies, their morphological variability has been used as primary fossil director to define specific regional trends and diachronic phases. However, an exhaustive analysis of manufacturing methods and techniques applied to shape this gear category is extremely rare. In fact, during the Late Epigravettian, except for a certain typological variability, the lack of detailed studies resulted in an apparent homogeneity in armatures production. In this paper, a technological and traceological approach applied to reconstruct the whole chaîne opératoire of armatures manufacture in three Northern Italian sites dated between 17,000 and 12,000 cal BP demonstrates important variations in how projectile implements are fashioned, concerning shape, production methods and retouch techniques. Moreover, a large-scale comparison suggests how renewals in projectile implements production in North-Eastern Italy may result from long-distance connections between human groups over the western Late Epigravettian territory.

Optimization the growth and quality of ‘Picual’ olive plants according to the dose of slow-release fertilizer

Due to its importance for oil production in Brazil and worldwide, the ‘Picual’ olive trees deserves special attention of to its good climatic adaptation and high yield and stability in the oil produced. However, there is a need to generate more technical information to improve the propagation and production system for nursery plants. The use of slow-release fertilizer (SRF) affects the quality standard of the plants formed in the nursery. The purpose of this study was to evaluate the effect of doses (0, 1.5, 3.0, 6.0, and 12 g L−1) of the SRF, Osmocote® (NPK 14-14-14), on morphological, biochemical and nutritional parameters of ‘Picual’ olive plants. It was found that the average value of maximum technical efficiency dose (MTED) for several morphological variables (plant height, stem diameter, total plant dry weight and root volume) was 7.18 g L−1. Furthermore, an Osmocote® dose of 8.35 g L−1 resulted in optimal leaf number and area. For the carbohydrate concentration (sucrose, starch and Total Soluble Sugar) in leaves, the best average values were obtained at 4.51, 5.48 and 6.12 g L−1 of Osmocote®, respectively. Additionally, the best growth responses of plants may also be due to increased internal macronutrient concentration such as nitrogen (N), phosphorus (P) and potassium (K) after treatment with 7.87 g L−1 of Osmocote®. The use of SRF (Osmocote®) is a viable alternative in the production of ‘Picual’ plants, as it promotes good morphological characteristics, synthesis of photosynthetic products as well as satisfactory nutritional status and plant growth.

Environment, intraspecific lineages and geographic range jointly shape the high morphological variability of Dikerogammarus villosus (Sowinsky, 1894) (Crustacea, Amphipoda): a successful aquatic invader across Europe

AbstractPhenotypic variability is a key factor promoting the establishment and spread of invasive populations in new environments. The Ponto-Caspian region contains a diverse endemic fauna known for its exceptional environmental plasticity, with many species invading European waters. However, the extent to which the environment shapes the phenotypic variability of these successful invaders remains poorly understood. We test to what extent the environment, intraspecific lineage affinity and geographic range interact and shape the variability of ecologically relevant functional morphological traits of the amphipod, Dikerogammarus villosus. Our results show the highest differentiation among environments, with an enhancement of predation-related traits in brackish waters relative to freshwaters. Differentiation among lineages and ranges (native/invaded) was smaller, occurring in traits related to locomotion and food processing. Although we uncovered an overall increase in variability outside the native range, the dynamics of morphological change were lineage-specific: the Western Lineage (invading via the River Danube) underwent a shift towards increased appendage length, while the Eastern Lineage (invading via the River Dnieper) underwent a significant overall morphospace expansion. We conclude that D. villosus exhibits a remarkable morphological variability across Europe that is influenced by the interplay between the environment as well as its evolutionary and invasion history.

Scale morphology variability in cyprinid fishes and its significance in taxonomy using light and scanning electron microscopy: A case study of the genus Garra Hamilton, 1822 (Teleostei: Cyprinidae).

To evaluate scale morphological variability (shape, size, topological macro- and microstructures, ornamentation patterns) of cyprinid fishes, nine species of the genus Garra were selected and their scales from five different body regions were studied by using light and scanning electron microscopy. The scales of the examined species were thin with a central or antero-centrally positioned focus, with no cteni in the posterior part. In addition to these typical characteristics, some morphological variation was observed in the overall shape (irregular round, true oval, round-triangular, irregular pentagonal, hexagonal, irregular hexagonal, pentagonal, ovoid), and the focus shape. These variations were mainly dependent on the fish lengths and the flank region. Morphological analysis clustered the examined species into two distinct groups. Group I consisted of G. amirhosseini and G. gymnothorax, while Group II has three subgroups, which include G. persica and G. mondica (subgroup I), G. meymehensis, G. rossica, G. nudiventris, G. hormuzensis (subgroup II), and G. rufa (subgroup III). The grouping of the studied Garra species based on the current scale morphological characters and the molecular data was only consistent for G. rossica and G. nudiventris. In addition, in the phylogenetic tree, G. persica, G. mondica, G. amirhosseini, and G. hormuzensis formed a distinct clade. However, these species did not represent close relationships in the dendrogram obtained from the scale morphology. A possible explanation why the grouping of the studied Garra species based on their scale morphological characters does not match their phylogenetic relationships is that most of the scale morphological traits vary depending on the fish size and the location of the scales on the flank. Therefore, except for some traits, that is, central or antero-centrally positioned focus, having no cteni, a specific sectioned form so called "tetra-sectioned" type, the other examined variables are not useful enough to be used in the taxonomic study of the examined cyprinid fishes. Therefore, scale morphological characters should be used carefully for taxonomic purposes. RESEARCH HIGHLIGHTS: Shape, size, topological macro- and microstructures, and ornamentation patterns of nine species of the genus Garra were studied by using light and scanning electron microscopy. The scales were thin with a central or antero-centrally positioned focus, with no cteni in the posterior part. Morphological variation was observed in the overall shape (irregular round, true oval, round-triangular, irregular pentagonal, hexagonal, irregular hexagonal, pentagonal, and ovoid), and the focus shape. The grouping of Garra species based on the current scale morphological characters and the molecular data was only consistent for G. rossica and G. nudiventris.

Decoupling the multi-drivers of urban extreme heat environment in urban agglomerations using ensemble learning

Urban extreme heat (UEH) has been imparting a formidable menace to various facets of sustainable urban and regional development. While increasing studies have examined the urban thermal environment, a gap exists in decoupling the nonlinear multi-drivers of UEH environment in intra-urban regions, especially across the urban agglomerations. In this study, we estimated UEH through the land surface temperature (LST) in the extended summer season exceeding a specific threshold computed through cross-regional statistics. Furthermore, an additive interpretable ensemble learning model enhanced via the Bayesian Optimization algorithm (BO) and Monte Carlo Simulation framework (MCS) was employed to dissect the intricate nonlinear interplay between UEH and intra-urban morphology, green-blue composition, and atmospheric determinants. Our results highlight the indispensably suppressive effect of green and blue factors on UEH, whereas urban morphological variables generally exhibit an opposite trend. Interestingly, we reveal heterogeneity responses of building heights, elevated urban structures mitigate UEH in temperate monsoon and subtropical monsoon zones and exhibit diminished marginal utility in temperate continental zones. Furthermore, the arid climatic characteristics are expected to exert an unexpectedly enhancing effect on water bodies' cooling capacity. These findings provide heterogeneous local guidance for landscape and urban planning towards the severe challenges of climate change.

The postcranial variability of Quaternary European rhinoceroses: the case study of Stephanorhinus hundsheimensis from the Middle Pleistocene site of Contrada Monticelli (Apulia, southern Italy)

ABSTRACT Five rhinoceros species, mainly distinguishable through cranial, mandibular and dental morphology, were recognized during the Quaternary across Europe. The postcranial morphology of these taxa is quite variable, with strong superposition among species, especially between Stephanorhinus etruscus and Stephanorhinus hundsheimensis. Here, the complete sample including 25 postcranial bones from the early Middle Pleistocene site of Contrada Monticelli (Apulia, southern Italy) is described and compared through morphological and biometric analyses. A few bones, in addition to cranial and mandibular remains from this site, have been previously referred to Stephanorhinus hundsheimensis. We explored the morphological variability of Stephanorhinus hundsheimensis from Contrada Monticelli against the diagnostic characters described in the literature. The size variation of the Contrada Monticelli sample is also investigated, through a comparison with other Quaternary European rhinoceros samples. Our results indicate a wide morphological variability with several distinct characters and a strong morphological affinity between Stephanorhinus etruscus and S. hundsheimensis. Our results suggest that Stephanorhinus hundsheimensis from Contrada Monticelli is a species with a high degree of intraspecific variability, possibly a hybrid population or a population including two morphotypes of the same species.

Cultural, Morphological and Pathogenic Variability in the Colletotrichum capsici Isolates, Inciting Anthracnose and Fruit rot of Chilli (Capsicum annuum L.) in different Agro-Climatic Zones of Kerala, India

Aims: To study the cultural, morphological and pathogenic variability existing among the pathogen isolates of Colletotrichum capsici, inciting anthracnose and fruit rot of chilli in Kerala. Study Design: Completely randomized design (CRD). Place and Duration of Study: Department of Plant Pathology, College of Agriculture (Kerala Agricultural University), Vellayani, Thiruvananthapuram during 2018-2019. Methodology: A survey was conducted in the five agro-climatic zones (ACZs) of Kerala viz., Northern zone, Central zone, Special problem zone, High range zone and Southern zone to assess the incidence and severity of anthracnose disease. The various symptoms in the surveyed locations were also noted. Pathogen isolates were grown in PDA medium in the laboratory and colony characters (colour and mycelial growth rate of pathogen colonies) were observed. Also, the morphological characters viz., mycelial width, shape and size of conidia, acervular diameter, number and size of setae, appressorial size were recorded. Results: Maximum anthracnose incidence of 90 per cent and severity of 52.60 per cent were noticed at Regional Agricultural Research Station (RARS), Pilicode (Northern zone). Characteristic leaf spot, fruit rot and die-back symptoms were observed in the survey locations. Pathogen colonies showed different shades of white, off-white to grey turning brown or black with regular or irregular margins and concentric rings of black acervuli in the potato dextrose agar (PDA) medium. The diameter of growth of C. capsici isolates ranged from 7.20 to 8.60 cm at 7 days after incubation. All the C. capsici isolates initiated hyaline mycelium having a width of 1.73 - 2.36 µm and produced numerous sickle shaped conidia with a size range of 19.42 - 20.46 µm × 2.16 - 3.09 µm. Black coloured, circular or ellipsoidal acervuli (122.14 - 189.08 µm dia.) had 20 – 46 setae of length 74.13 to 107.30 µm. Also, brown or black appressoria of size 8.64 - 12.64 µm × 5.54 - 7.84 µm were formed in slide culture. Cc3 from College of Agriculture, Vellanikkara was obtained as the most virulent isolate producing a lesion size of 1.13 cm and PDI of 45.33 in the artificially inoculated chilli fruits (var. Vellayani Athulya) at 5 days after inoculation. Conclusion: All the nine C. capsici isolates exhibited variability in their cultural, morphological and pathogenic characteristics. Variability in phytopathogenic fungi helps in identifying novel and sustainable control methods to tackle the diseases incited by them. Understanding pathogen variability provides new insights for developing effective disease management methods. This will help in promoting sustainable agriculture and preventing severe crop losses.

Effects of Some Physical Exercises with a Diet using artificial intelligence on Some Morphological Variables Related to Health in Obese Persons

The current research aims to identify the effects of physical exercises accompanied by a diet on some health-related body morphology variables and weight loss among obese persons. The researcher used the experimental approach (one-group design) with pre- and post-measurements. The researcher purposefully chose (16) obese persons, (12) of them were recruited as a main sample while (4) were recruited as a pilot sample. Results indicated that: The recommended exercise program with diet had positive effects on health-related physical fitness variables (speed – endurance – agility – power – strength – cardiorespiratory strength) among obese persons. The recommended exercise program with diet had positive effects on weight reduction variables (body weight – BMI – Fat percentage) among obese persons. Exercise with diet helped decrease weight among obese persons. There are statistically significant differences between the pre-and post-measurements of health-related physical fitness variables (among obese persons in favor of post-measurements. There are statistically significant differences between the pre-and post-measurements of weight decrease among obese persons in favor of post-measurements.

Genetic Basis for Morphological Variation in the Zebrafish Danio rerio: Insights from a Low-Heterozygosity Line

Data variability complicates reproducibility and the interpretation of experimental results. Different animal models have been employed to decrease variability to enhance experimental power. However, variation frequently persists among and within strains/lines. In zebrafish (Danio rerio), inbred lines (e.g., NHGRI-1) derived from wild-type lines have been produced to greatly decrease genetic variation, with the goal of providing better understanding of genetic backgrounds that may influence the experimental outcome of studies employing such lines. We hypothesized that variations in morphological phenotypes shaped by environmental stressors early in development are correlated with the intrinsic degree of genetic variability of zebrafish lines. We compared morphological variability (yolk–chorion ratio, body mass, embryo mass, total length, condition factor, and specific growth rate) in wild-type AB and NHGRI-1 zebrafish lines as a function of their responses to altered temperature and oxygen availability during the first 7 days post-fertilization. Overall, both lines showed similar developmental trajectories for yolk–chorion ratio, embryo mass, and total length. Additionally, condition factor and specific growth rate showed similar responses within each line, regardless of temperature and hypoxia. Importantly, the coefficient of variation for each variable was significantly lower in NHGRI-1 than AB larvae for 151 of 187 assessed morphological endpoints. Thus, the low-heterozygosity NHGRI-1 zebrafish line can be useful for decreasing inter-individual variation in morphological responses to environmental stressors, thereby aiding in the interpretation of results and enhancing experimental reproducibility.

Lack of Genetic Variation in Low Heterozygosity and Clonal Animals Creates Lack of Physiological Variation

Data variability frequently complicates reproducibility and interpretation of experimental results. Such variability arises from numerous sources such as differences in procedures or not accounting for key biological factors (e.g. sex, biological rhythms, prandial state). Making the situation more problematic, variation in physiological performance is often viewed as highly labile, easily and rapidly influenced by environmental stressors, development, etc., making it diffcult to pin down a source for variation. Undeniably, however, unknown (or ignored) genetic variation among and within strains/lines can also be a significant source of data variability in published physiological measurements, though surprisingly this has not been extensively investigated as a specific source of physiological variation. We hypothesized that variation in physiological performance is correlated with the intrinsic degree of genetic variability of the subject animal. To test this hypothesis, we employed two animal models: 1) Inbred lines ( e.g., NHGRI-1) derived from wild type strains of the zebrafish ( Danio rerio), with an estimated 15% of the genetic heterozygosity of wild type AB zebrafish, and 2) the parthenogenetically reproducing marbled crayfish ( Procambarus virginalis), all specimens of which are genetically identical clones. For these two animal models, we measured both physiological variables (e.g. heart rate, stroke volume, cardiac output, oxygen consumption) and morphological variables (e.g. yolk-chorion ratio, body mass, embryo mass, total length, condition factor, specific growth rate) during development. We subjected the two animal models to environmental stress in the form of both temperature and hypoxia to stimulate physiological responses that could be compared and contrasted among populations. From these data we then calculated the resultant coeffcients of variation for measured variables for wild type and low/zero heterozygosity populations and/or species. In zebrafish, both the wildtype AB and NHRGI-1 lines showed similar developmental trajectories characterized by similar mean values for physiological and morphological variables. Additionally, similar mean values for physiological and morphological variables were recorded in the face of temperature and hypoxia challenge. Yet, importantly, the coeffcient of variation for each measured variable was significantly lower in NHGRI-1 than AB larvae for &gt;90% of the assessed endpoints. In the clonal crayfish, genetically identical early stage marbled crayfish reared in different temperatures or oxygen levels show major acclimation responses, but generally showed less morphological and physiological variation about the mean than sexually-reproducing species crayfish with inherently much greater genetic variation, as evident from comparisons of calculated coeffcients of variation. A key question regarding the clonal crayfish is how can there be any morphological or physiological variation between individuals? We suggest that variability that persists may arise from microenvironmental differences during rearing (e.g. egg position during incubation on the mother’s pleon) and/or stochastic differences in gene expression (e.g. due to random epimutations) in this clonal species. In conclusion, genetic diversity clearly contributes to physiological variability. For future experiments, low heterozygosity lines and/or clonal species may be useful for decreasing inter-individual variation, thus aiding interpretation of results and enhancing reproducibility. In any event, scientific documentation of physiological studies should include as much information on (genetic) background of the experimental animals as possible. NSF IOS-2103499. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Morphometric analysis of the Late Cretaceous Placenticeras of Alabama, USA: sexual dimorphism, allometry, and implications for taxonomy

AbstractA traditional typological approach to taxonomy often does not adequately account for intraspecific variation and can result in taxonomic oversplitting. For many groups, including ammonoids of the Placenticeras genus, intraspecific variation documented in recent studies (e.g., ontogenetic changes, sexual dimorphism, polymorphism) challenges the historic proliferation of species names. Here, we used a population approach to taxonomy and quantitatively evaluated morphometric variation in a sample of Late Cretaceous (Santonian–Campanian) Placenticeras from Alabama and adjacent counties.We used linear mixed models (LMMs) to characterize how morphological variables scale with conch size across the sample, exploiting mixed longitudinal data to evaluate individual variation in growth and inform interpretations of multivariate analyses. Extended LMMs incorporating geological formation evaluated morphological changes through time. Principal component analysis and clustering analysis were then used to evaluate the number of distinct clusters that emerged in multivariate morphospace independent of previous taxon name assignments.Discontinuous scaling relationships and distinct clusters in multivariate space suggest sexual dimorphism characterized by differences in adult size and, secondarily, shape. Previous Stantonoceras and Placenticeras assignments broadly overlap in our morphospace, failing to justify this historic distinction (as sexual dimorphs or as genera or subgenera). Placenticeras conch morphology and ornament placement changed through time, suggesting a potential utility for coarse (stage-level) biostratigraphy. However, temporal changes were not associated with distinct clusters in morphospace, and our data fail to support the plethora of reported species names. As few as one or two (successive) species may be present in our sample (representing 130 years of collection effort). In addition to highlighting the need for a significant taxonomic revision of the Placenticeras genus, this study demonstrates the utility of LMMs for distinguishing between different sources of morphological variation, improving interpretations of morphospace under a population approach to taxonomy, and maximizing the amount of ontogenetic information that can be obtained nondestructively.

The Wind Profile Characteristics of Super Typhoon Lekima Based on Field Measurement

Many cities in coastal areas are prone to typhoon disasters due to their location on the Pacific storm path, and the direct effect of catastrophic winds can lead to the destruction of low-rise buildings and severe damage to high-rise structures. The purpose of this study was to enhance the understanding of boundary layer wind profiles of strong typhoons in coastal areas and reduce property losses and casualties caused by wind disasters. Based on the field measurements of wind profile acoustic radar in coastal areas, the variation characteristics of the boundary layer wind profile during the passage of super typhoon Lekima were first studied in depth, and the evolution law of the typhoon boundary layer profile was summarized. Then, the effects of typhoon horizontal structure, topography, wind speed, and time distance on the characteristics of the typhoon profile were discussed, respectively. Finally, the evolution characteristics of wind profile parameters were obtained by fitting three wind profile theoretical models. Due to the strong variability of typhoon profile morphology, the theoretical model of wind profile is only applicable to the wind profile from the bottom to the low-level jet height of typhoons, while wind parameters are closely related to the spatial location of the typhoon wind field.

Alpha-taxonomy underestimates the diversity in Jacquemontia (Convolvulaceae): a new hypothesis for Jacquemontia evolvuloides complex based on morphological, anatomical, and morphometric analyses

Interpreting plant morphological variability makes species delimitation a challenge. Jacquemontia evolvuloides and its relatives have been the target of different taxonomic classifications, either as multiple species and subspecies/varieties or as a single polymorphic species. Here we applied univariate and multivariate morphometric analyses, using both macro- and micromorphological characters of 22 populations comprising this species complex. Our analysis revealed six morphotypes with clear discontinuities in both macro- and micromorphological characters. One morphotype corresponds to J. evolvuloides, two correspond to previously named species, putted under a synonym, here re-established (J. agrestis and J. decumbens) and three morphotypes correspond to new species, described here. We present a complete taxonomic treatment of J. evolvuloides and related species, with descriptions, distribution maps, photographs, and illustrations, that indicate new synonyms.

Significance and Clinical Implications of Morphometric and Morphological Variability in Cadaveric Liver.

Background This study aimed to identify morphological variations, conduct morphometry of the liver, and present its clinical implications. Methodology The study was conducted on 35 preserved cadaveric livers without macroscopic abnormalities. Morphological features such as shape and size were studied and variations such as the absence of lobe, accessory fissures, or accessory lobes were noted in all specimens. Results The caudate lobe was absent in one liver, and the quadrate lobe was absent in six livers. Moreover, seven livers had accessory fissures, and accessory lobes were seen in six livers. The left lobe with a lingular process was seen in three livers, and diaphragmatic grooves were present in seven livers. Conclusions The present research is helpful to radiologists, surgeons, and anatomists as it demonstrates the different morphological variations in the liver.