Number Of Lamellae Research Articles

Claws and toepads in mainland and island Anolis (Squamata: Dactyloidae): Different adaptive radiations with intersectional morphospatial zones.

Anolis lizards have evolved morphologies in response to different selective factors related to microhabitat use. Morphological diversity exhibits evolutionary patterns that reveal similarities and unique regional traits among the mainland and island environments and among Greater Antilles and Lesser Antilles islands. In the Greater Antilles and mainland environments anole species are classified into morphological/ecological groups, that are known as morphotypes (mainland) or ecomorphs (Greater Antilles). Morphotypes are defined only with morphological information; in contrast, for ecomorph assignment both morphology and ethology are required. For mainland species distributed in northwestern South America 10morphotypes were proposed to include the morphological diversity of 59species. We obtained data from body size, limbs length, tail length, and the number of lamellae for an additional ten species occurring in the same region and assigned them into morphotypes. We also collected data of the claw and toepad diversity of mainland and island Anolis from northwestern South America and compared it to the claw and toepads morphology recorded for the Greater Antilles and Lesser Antilles islands, under a phylogenetic framework. We found new island morphotypes (MT11-MT13) of Anolis from northwestern South America. When comparing claws and toepads morphology among the 13morphotypes we found that morphological variation of these traits partially corresponds to morphotype groups. For instance, habitat specialist species like Anolis heterodermus, classified in morphotype 4 (MT4), have a characteristic design of broad toepad and reduced claws, and non-unique design of toepads and claws occurs in morphotypes MT1, MT2, MT5, MT10, and MT13. We also compared claws and toepads of fore and hindlimbs within the same individual, and found that even if limbs show differences in claws and toepads, suggesting that they perform differential biomechanical function, the degree of within individual variation is specific and not related to morphotype assignment. Our data supported the convergent and unique regional evolution among mainland and island anoles, and revealed aspects of correlative evolution of functional traits of claws and toepads that probably are related to minor differences in microhabitat use among mainland and island species, as suggested by previously published literature. Lastly, the evolutionary pattern of morphological diversity of claws and toepads of Anolis in the mainland and island environment supports both unique regional traits and common selective and historical factors that have molded Anolis morphological diversity.

Yield photosynthesis and leaf anatomy of maize in inter- and mono-cropping systems at varying plant densities

Increasing plant density can increase cereal crop yields. However, the physiological and anatomical mechanisms of grain yield increase at high plant densities in maize-based intercropping systems are not well understood. A two-year field experiment was conducted in 2018 and 2019 to investigate grain yield, photosynthetic characteristics, stomatal traits, and leaf anatomy of maize plants in an intercropping system with high plant densities. Two cropping patterns (monocropping and intercropping) and three plant densities (D1, 78,000 plants ha−1; D2, 103,500 plants ha−1; D3, 129,000 plants ha−1) were arranged in a randomized block design. Increasing maize plant density significantly increased maize yield, and intercropping gave a significant yield advantage over monocropping under the same plant density. Intercropping combined with high plant density increased the leaf area and SPAD value of maize, increasing the photosynthesis rates after the harvest of pea. At the twelfth leaf stage, the stomatal density and stomatal area of intercrops combined with medium plant density increased by respectively 10.5% and 18.4% relative to their values for the corresponding density of monocrops. Although leaf thickness of maize was reduced by increasing plant density, the chloroplast number and grana lamella number were higher in intercropping than in monocropping under different plant densities. These positive changes in leaf anatomy resulted in increased photosynthesis, suggesting a physiological basis for the increase in grain yield.

Abstract 13462: Assessment of the Physiological and Pathological Structural Differences Along the Aorta in a Rat Model of Metabolic Syndrome

Introduction: Vascular geometry may vary along the aortic length in normal and chronic disease conditions such as metabolic syndrome. Aim: This study investigated regional structural changes in the aorta in a rodent model of metabolic syndrome, the high-fat diet streptozotocin-induced diabetes mellitus (HFD-D). Methods: Four-week-old male Wistar albino rats received a control diet (CD) or high fat diet (HFD) for 10 weeks. On week 6, 40 mg/kg streptozotocin and its buffer were injected intraperitoneally into the HFD and CD groups, respectively. Glucose and insulin tolerance tests (GTT and ITT) and tail-cuff systolic blood pressure (SBP) were measured. At the end of the study, rats were euthanized, and the thoracic and abdominal aortic segments collected for histomorphometric analysis of aortic media thickness, medial cross-sectional area (CSA), elastic lamellae number, interlamellar spacing, collagen density and lipid deposit density. Results: HFD-D rats showed elevated GTT, ITT and SBP. Abdominal aortic segments of both CD and HFD-D rats showed smaller media thickness and CSA, lower elastin lamellae number and higher collagen density compared with the thoracic segments, suggestive of physiological rather than pathological structural differences in both groups. Elastin interlamellar spacing and lipid plaque deposits were higher in the abdominal aorta of the HFD-D relative to controls, indicating that early vascular pathological changes favor the abdominal aorta in HFD-D rats. Conclusions: In this disease model of metabolic syndrome, vascular structural changes are differentially expressed along the aorta, with pathological features limited to the abdominal rather than the thoracic aorta. These structural abnormalities may underlie the elevated blood pressure seen in this model and potential progression to hypertensive cardiovascular disease.

Clinging performance on natural substrates predicts habitat use in anoles and geckos

Abstract For arboreal lizards, the ability to cling or adhere to the substrate is critical for locomotion during prey capture, predator escape, thermoregulation and social interactions. Thus, selection on traits related to clinging is likely strong. Correlations between morphology, performance and habitat use have been documented in arboreal lizards, providing a framework for using functional traits to predict habitat use in the field. We tested the hypothesis that clinging performance predicts habitat use in an actively assembling community of introduced lizards in Hawaiʻi comprised of anoles (Anolis carolinensis, A. sagrei) and day geckos (Phelsuma laticauda). We measured morphological traits (toepad area and lamellae number) and tested clinging performance on two artificial and eight natural substrates in the laboratory. We measured habitat use in 10 m × 10 m outdoor enclosures where habitat availability was controlled and the lizard species assemblage was manipulated to reflect all species combinations. The enclosure experiment generated more than 9,000 habitat use observations from 360 lizards. Morphological traits that predict performance in Anolis were not predictive in Phelsuma, indicating that direct measures of performance are necessary for comparisons between the genera. Measuring clinging performance on multiple substrates provided key insights into patterns of habitat use. While all three species performed best on an artificial smooth substrate (acrylic), performance on natural substrates predicted which texture (rough vs. smooth) was most often used by each species. Performance predicted perch height use: species with the greatest clinging performance (A. carolinensis and P. laticauda) across substrates perched twice as high as A. sagrei. We did not observe habitat shifts in the height or texture of perches used by any species in response to experimental manipulation of the lizard species assemblage. Our results highlight the inextricable link between ecology, morphology and performance, the importance of measuring functional traits in ecologically relevant ways, and the potential for resource partitioning to be influenced by differences in the ability to attach to different substrates.

Survey of the extracellular matrix architecture across the rat arterial tree

ObjectiveTo understand arterial remodeling and the pathophysiology of arterial diseases, it is necessary to understand the baseline qualities and variations in arterial structure. Arteries could differ in wall thickness, laminar structure, and laminar fenestration depending on their position within the arterial tree. We endeavored to evaluate and compare the extracellular matrix structure of different arteries throughout the arterial tree, from the aorta to the adductor muscle arteriole, with a particular focus on the internal elastic lamina (IEL). MethodsArterial segments were harvested from male Sprague-Dawley rats and imaged using multiple modalities. En face scans by multiphoton microscopy were used to compare native-state adventitial collagen undulation and IEL fenestration. ResultsCollagen undulation was similar across most examined arteries but straighter in the skeletal muscle arterioles (P < .05). The elastic lamellae showed several differences. The IEL fenestrae were similar in average size among abdominal aorta and celiac, renal, common iliac, and common femoral arteries (range, 14-24 μm2), with wide within-vessel variance (square of the standard deviation, 462-1904 μm4). However, they tended to be smaller (9.08 μm2) and less variable (square of the standard deviation, 88.3 μm4) in the popliteal artery. Fenestrae were greater in number in the superior mesenteric artery (SMA; 6686/mm2; P < .05) and profunda femoris artery (PFA; 11,042/mm2; P < .05) compared with the other examined vessels, which ranged in surface density from 3143/mm2 to 4362/mm2. The SMA and PFA also showed greater total fenestration as a proportion of the IEL surface area (SMA, 15.04%; P < .05; PFA, 24.11%; P < .001) than the other examined arteries (range of means, 4.7%-9.4%). The arteriolar IEL was structurally distinct, comparable to a low-density wireframe. Other structural differences were also noted, including differences in the number of medial lamellae along the arterial tree. ConclusionsWe found that vessels at different locations along the arterial tree differ in structure. The SMA, PFA, and intramuscular arterioles have fundamental differences in the extracellular matrix structure compared with other arteries. Location-specific features such as the medial lamellae number and elastic laminar structure might have relevance to physiology and confer vulnerabilities to the development of pathology.

A cryptic new species of rupicolous Hemidactylus Goldfuss, 1820 (Squamata: Gekkonidae) allied to H. aaronbaueri Giri, 2008 from the northern Western Ghats of Maharashtra, India.

We describe a cryptic new species of large-bodied rupicolous Hemidactylus allied to H. aaronbaueri from Tamhini Ghat, in Raigad and Pune districts of Maharashtra state, India. Hemidactylus tamhiniensis sp. nov. falls within the prashadi group of Indian Hemidactylus and can be diagnosed from all other members of the group by combination of several morphological characters such as its large-body size (maximum SVL 126 mm), the number of femoral pores and poreless scales between the left and right series of femoral pores in males, and the number of transverse ventral scales across the belly at mid-body. The new species differs from H. aaronbaueri based on dorsal pholidosis at mid-body, the number of undivided lamellae beneath the first finger, the number of internasal scales, and subtle colour pattern differences, besides 10.6% uncorrected ND2 sequence divergence.

Ультраструктурні зміни сідничого нерва мишей з периферичною нейропатією після трансплантації мультипотентних мезенхімальних стромальних клітин жирової тканин

We investigated the peripheral demyelination in transgenic mice with peripheral neuropathy and the effect of adiposederived multipotent mesenchymal stromal cells (ADSCs) transplantation on the ultrastructural features of the sciatic nerve in these mice. The B6.Cg-Tg(PMP22)C3Fbas/J transgenic mice with peripheral neuropathy were injected intramuscularly with ADSCs, which were isolated from the adipose tissue of FVB-Cg-Tg(GFPU) mice transgenic by GFP. For ultrastructural analysis, tissue fixation in animals was performed by transcardiac perfusion-fixation with 4% formaldehyde solution and 2.5% glutaraldehyde solution 16 weeks after transplantation. Electron microscopic examination of fibers of the sciatic nerve in the transgenic mice with peripheral neuropathy showed that many axons in this nerve were subjected to dys- and demyelination; the so-called onion bulb-like structures were observed. In some fibers, hypertrophy of myelin sheaths was found. In general, ultrastructural modifications in the sciatic nerve of the transgenic mice were rather similar to the pathomorphological pattern observed in patients with peripheral neuropathy. At 16 weeks after ADSC transplantation, in the sciatic nerve in mice with peripheral neuropathy thickening of the myelin sheath and increasing of the number of lamellae were observed. Thus, ADSC transplantation in mice with hereditary peripheral neuropathy has a protective effect on the ultrastructural features of the sciatic nerve and inhibits the process of axon demyelination.

Influence of critical parameters on nanoparticles-surfactant stabilized CO2 foam stability at sub-critical and supercritical conditions

The stability of CO2-foam stabilized via the synergy of nanoparticles and surfactants at downhole conditions is strongly affected by different process parameters such as temperature, CO2 state, nanoparticles concentration, as well as resident brine and oil in the reservoir. Influence of critical parameters on static and dynamic stability of nanoparticles-surfactant stabilized CO2-foam at sub-critical and super-critical conditions was investigated in this study. Firstly, extensive static and dynamic foam stability experiments were conducted at 80 °C and presence of 30 vol% hexadecane oil using formulation turbiscan, to screen different surfactants and nanoparticles. The best performing nanoparticles and surfactant were then selected at the screening stage for further foam stability tests to compare the performance of CO2 foam at sub-critical and super-critical conditions. The foam stabilized by SiO2 and sodium dodecyl sulfate (SDS) demonstrated consistent static and dynamic stability, with least spreading coefficient (-5.28 mN/m) and favourable Lamellae number (0.71). Increasing nanoparticles concentration increased the stability of sub-critical CO2 foam whereas an optimum nanoparticles concentration for maximum stability of the supercritical CO2 foam was obtained as 0.5 wt% SiO2. The static stability of sub-critical and supercritical CO2 foam increased with increased sodium chloride (NaCl) concentrations until 2 wt%. However, the super-critical CO2 foam demonstrated increasing pressure drop and lowest reduction in mobility with increasing NaCl concentration until 10 wt%. Highly durable foams were generated when oil with high viscosity, high density and high molecular weight oil was added into the foaming dispersions. Mechanistic investigation of foam stabilization revealed that thickness of pseudo-emulsion films, as well as particles adsorption and orientation at gas–liquid and liquid–liquid interface, are key controlling parameters of foam static and dynamic stability in presence of oil, brine and at high temperature.

Histological Studies on Ageing Changes in the Cornea of Indian Buffaloes (Bubalus bubalis)

Background: Affections of eye commonly encountered in all the species of animals. If these not treated in time, the vision may be hampered, this may impair the physical ability, utility and productivity of animals leading to economic loss to the animal owners. Corneal dystrophies like basement membrane dystrophy, stromal dystrophy, endothelial dystrophy, corneal erosions and corneal ulcerations etc., seen in the aged buffaloes. The current study was carried out to establish basic data and to provide authentic information to the clinicians on ageing changes in eyes of buffaloes.Methods: The study on age related changes in the cornea was conducted on 63 eye balls of locally available buffaloes of different breeds in and around Proddatur. These buffaloes were categorized into 3 groups based on their age i.e., group I (1-5 yrs), group II (6-10 yrs) and group III (11 yrs and above) buffaloes. The eyeballs were isolated and fixed with Davidson’s fluid. The paraffin sections of cornea were subjected for routine histological study.Result: The mean total thickness (µm) of cornea was increased from group I to III animals and it was 747.22±13.57, 853.33±11.05 and 897.22±8.06. Hence, The mean thickness (µm) of all five layers of cornea increased with advancement of age. Superficial corneal epithelial layer was made up of non keratinized stratified squamous epithelium with 6 to 7 layers at early age and 12-14 layers of cells in adult animals. The mean thickness (µm) of corneal epithelium in group I to III animals was 117.04±3.37, 122.59±2.23 and 133.71±3.55 respectively. Bowman’s membrane of cornea was measured 12.97±0.86, 17.22±0.55 and 18.71±0.68 in group I, II and III animals respectively. The mean thickness (µm) of corneal stroma in group I to III animals was 600.75±10.33, 672.22±10.46 and 690.00±5.32 respectively. This was mainly due to progressive increase in number of collagenous lamellae. The keratocytes became thin in old animals. Thickness of posterior band zone (PBZ) of Descemet’s membrane was increased with advancement of age. The mean thickness (µm) of Descemet’s membrane and endothelium together was in group I, II and III animals was 16.48±0.91, 41.29±2.25 and 54.82±1.44 respectively. The corneal endothelial cells were enlarged and increased in size in old buffaloes. The age related pigmentation was also noticed in epithelium and stroma of cornea in animals of group III. Density of sub basal nerve plexuses between the stroma and the corneal epithelium was not altered with advancement of age.

A novel small-bodied rupicolous Cnemaspis Strauch, 1887 (Squamata: Gekkonidae) from the northern Western Ghats, Maharashtra, India, with comments on the status of C. indraneildasii, Bauer 2000.

We describe a distinct new rupicolous Cnemaspis based on four adult specimens collected from the Kedareshwar caves on Harishchandragad mountain, from the northern Western Ghats, approximately 1200 m asl. in Ahmednagar district of Maharashtra state, India. Cnemaspis uttaraghati sp. nov. can be diagnosed from all other peninsular Indian congeners by its small body size (maximum SVL < 39 mm), heterogeneous dorsal pholidosis, presence of spine-like tubercles on flanks; presence of only femoral pores in males; tail with enlarged, strongly keeled, conical tubercles forming whorls; median row of sub-caudal scales smooth, slightly enlarged, regularly arranged with condition of two slightly larger scales alternating with a large divided scale. The new species is likely to be allied to the C. girii clade and can be diagnosed from its members by its slightly larger body size, presence of spine-like tubercles on flanks, the number of enlarged tubercles in paravertebral rows between forelimb and hindlimb insertions, the number of dorsal tubercle rows at mid-body, the number of ventral scales across belly at mid-body, the number of longitudinal ventral scales from mental to cloaca, and the number of lamellae under digit IV of manus. We also provide a detailed morphological dataset for C. goaensis and C. indraneildasii based on topotypic material and specimens collected from additional localities to confirm C. indraneildasii is a junior synonym of C. goaensis, and provide an updated diagnosis for C. goaensis.

Evolutionary Dynamics of the OR Gene Repertoire in Teleost Fishes: Evidence of an Association with Changes in Olfactory Epithelium Shape.

Teleost fishes perceive their environment through a range of sensory modalities, among which olfaction often plays an important role. Richness of the olfactory repertoire depends on the diversity of receptors coded by homologous genes classified into four families: OR, TAAR, VR1, and VR2. Herein, we focus on the OR gene repertoire. While independent large contractions of the OR gene repertoire associated with ecological transitions have been found in mammals, little is known about the diversity of the OR gene repertoire and its evolution in teleost fishes, a group that includes more than 34,000 living species. We analyzed genomes of 163 species representing diversity in this large group. We found a large range of variation in the number of functional OR genes, from 15 in the Broad-nose Pipefish Syngnathus typhle and the Ocean Sunfish Mola mola, to 429 in the Zig-zag Eel Mastacembelus armatus. The number of OR genes was higher in species when a multilamellar olfactory rosette was present. Moreover, the number of lamellae was correlated with the richness of the OR gene repertoire. While a slow and balanced birth-and-death process generally drives the evolution of the OR gene repertoire, we inferred several episodes of high rates of gene loss, sometimes followed by large gains in the number of OR genes. These gains coincide with morphological changes of the olfactory organ and suggest a strong functional association between changes in the morphology and the evolution of the OR gene repertoire.

Age and growth of Palaeoloxodon huaihoensis from Penghu Channel, Taiwan: significance of their age distribution based on fossils.

Dental material attributed to Palaeoloxodon huaihoensis from the Middle to Late Pleistocene were recovered over decades from the Penghu Channel during commercial fisheries activities. The National Museum of Nature Science (NMNS) has a collection of such dental material, which differs in size and morphology and likely represents ontogenetic variation and growth trajectory of various age groups of P. huaihoensis. However, little is known regarding age determination. By using length of dental material, enamel thickness (ET), and plate counts, we established the method to distinguish the age of the species, which is directly derived from the extant African forest elephant Loxodonta africana. When measuring signs of allometric growth, we found that in both the upper and lower jaws, tooth width was correlated negatively with lamellar frequency but positively with ET. In the same age group, the number of lamellae was higher in P. huaihoensis than in L. africana. The reconstructed age distribution indicated no difference in the upper or lower jaw. Notably, within our sample, P. huaihoensis is skewed towards adult and older individuals with median age between 33–34.5 years and differed significantly from that of Mammuthus primigenius in the European Kraków Spadzista site. This age distribution pattern is speculated to be related to the harsh environmental conditions and intense intraspecific competition among P. huaihoensis during the last ice age.

Ontogeny of the brain of Microglanis garavelloi Shibatta and Benine 2005 (Teleostei: Siluriformes: Pseudopimelodidae).

The gross brain morphology and the peripheral olfactory organ of Microglanis garavelloi are described throughout development, and the relationship of these organs to the general behaviour of the species is discussed. During the development, the main brain subdivisions undergo a series of morphological changes keeping a relatively constant volume increase. However, we observed different growth rates in the brains of males and females when these were compared. During the maturation process, a series of hormonal events result in the development of some secondary sexual traits in the brain of male specimens, like faster growth rate of brain areas linked to motor control, olfactory and visual responses. The number of olfactory-organ lamellae increases continuously in both males and females, during their maturation period. These results suggest that changes may be caused by cognitive demands that this species is exposed to throughout its lifespan. The gross morphological arrangement of the central nervous system indicates shared patterns with other members of the family Pseudopimelodidae.

Neuromorphological disparity in deep-living sister species of the Antarctic fish genus Trematomus

Because sister species share a phenotypic axis, they hold morphological and ecological traits in common and, when sympatric, are ideal subjects for examining the extent of morphological divergence associated with the non-shared ecological parameters of the niche. Trematomus lepidorhinus and T. loennbergii have overlapping depth ranges of > 1000 m and occupy the deep shelf-upper slope niche in the waters of East Antarctica, an area where glacial troughs and their 1000–1500 m-deep landward basins (innershelf depressions) encompass 40% of the sea floor. The sense organ and brain divergence between the two species at the gross anatomical and histological levels involves differences in: number of olfactory lamellae, composition of the photoreceptor array and the number of retinal cells, size of the cephalic lateral line pores, and overall size of the brain and degree of development of different brain regions. Size and shape of the sagittal otoliths also differ. The morphology is unequivocally differentiating for habitat depths and conclusively documents a shift toward reliance on non-visual senses in T. loennbergii, consistent with collection data indicating this species lives at greater depths than T. lepidorhinus. Depths of peak abundances—200–500 m for T. lepidorhinus and 600–800 m for T. loennbergii—are the major differentiating parameter, with the ≈300 m differential between the peaks providing considerable, although not absolute, habitat separation. This is also reflected in the greater absolute abundances of the shallower-living T. lepidorhinus in trawl catches. Only T. loennbergii is found near the floors of 1000–1500 m-deep innershelf depressions, a distinctive microhabitat on the high latitude shelf.

Ontogenic Development Of Gills In Pre To Post-Flexion Stages Larvae Of Himalayan Snow Trout Schizothorax Plagiostomus (Heckel)

The ontogenic development of gills, including gill arch, gill filaments, and gill rakers in pre to postflexion stages larvae of Himalayan Snow Trout Schizothorax plagiostomus were studied with the objectives that this study could serve as a base for further studies about the early embryonic development and organogenesis in various fish species inhabiting hill stream environments. To obtain the pre to post-flexion stages larvae, an artificial breeding experiment was conducted during September- October on the bank of snow-fed river Alaknanda by stripping method. Further, the development of the gill apparatus was studied histologically, using light microscopy. Hatchling takes place 124-130 hours after fertilization at the incubation temperature of 19-200C. On second dph (day post-hatching), gill arches, gill filaments, and branchiostegal membrane began to differentiate. By the third dph, blood channels were observed in gill filaments as well as in pseudobranch. Formation of secondary lamellae, branchial arteries, elongation of the gill cover, cartilaginous rod formation in the gill arch, and the branchiostegal membrane was discernible by fourth-fifth dph. Pillar cells and afferent and efferent arteries with RBCs in primary and secondary lamellae were observed on the seventh dph. Around the onset of exclusive exogenous feeding (twelfth dph), gill rakers and a group of pillar cells with blood channels were recognizable. Well-organized and functional gill structures with increased number and size of secondary gill lamellae were present among the fifteenth-seventeenth dph larvae. The general pattern of structural and functional development of both the natural site and laboratory-reared larvae was similar, except a large amount of mucous and clustered epithelial cells among the laboratory-reared larvae, which may be due to the physiological as well as environmental stress posed by the adverse physicochemical conditions.

Geochemistry drives the allometric growth of the hydrothermal vent tubewormRiftia pachyptila(Annelida: Siboglinidae)

AbstractThe tubeworm Riftia pachyptila is a key primarily producer in hydrothermal vent communities due to the symbiosis with sulphur-oxidizing bacteria, which provide nourishment to the worm from sulphides, oxygen and carbon dioxide. These substances diffuse from the vent water into the bloodstream of the worm through their tentacular crowns, and then to the bacteria, hosted in a specialized organ of the worm, called a trophosome. The uptake rates of these substances depend on the surface/volume relationship of the tentacles. We here describe two morphotypes, ‘fat’ and ‘slim’, respectively, from the basalt sulphide-rich vents at 9 °N and 21 °N at the East Pacific Rise, and the highly sedimented, sulphide-poor vents at 27 °N in the Guaymas Basin. The ‘fat’ morphotype has a thicker body and tube, longer trunk and smaller tentacular crowns, whereas the ‘slim’ morphotype has shorter trunk, thinner body and tube, and presents longer tentacular crowns and has a higher number of tentacular lamellae. Given the dependence on sulphides for the growth of R. pachyptila, as well as high genetic connectivity of the worm’s populations along the studied localities, we suggest that such morphological differences are adaptive and selected to keep the sulphide uptake near to the optimum values for the symbionts. ‘Fat’ and ‘slim’ morphotypes are also found in the vestimentiferan Ridgeia piscesae in similar sulphide-rich and poor environments in the northern Pacific.

Evolution of Low‐Frequency Vibrational Modes in Ultrathin GeSbTe Films

GeSbTe (GST) phase‐change alloys feature layered crystalline structures made of lamellae separated by van der Waals (vdW) gaps. This work sheds light on the dependence of interlamellae interactions at the vdW gap on film thickness of GST alloys as probed by vibrational spectroscopy. Molecular beam epitaxy is used for designing GST layers down to a single lamella. By combining density‐functional theory and Raman spectroscopy, a direct and simple method is demonstrated to identify the thickness of the GST film. The shift of the vibrational modes is studied as a function of the layer size, and the low‐frequency range opens up a new route to probe the number of lamellae for different GST compositions. Comparison between experimental and theoretical Raman spectra highlights the precision growth control obtained by the epitaxial technique.

Artificial intelligence approach to palaeogeography and evolutionary trend analysis of Laurentian brachiopod fauna in the Rhynchotrema-Hiscobeccus lineage

Previous studies, based on the qualitative morphological description on the Late Ordovician brachiopod fauna hypothesized that the earliest species of Hiscobeccus, which is one of the diagnostic taxa in North American epicontinental brachiopod fauna, evolved from Rhynchotrema, a well-known rhynchonellide brachiopod, which lived in pericratonic regions of Laurentia. A quantitative approach conducting multivariate analysis, which was based on biometric characters of rhynchonellide brachiopod specimens from the Late Ordovician (upper Sandbian–upper Katian) in North America, supported this hypothesis that the younger and larger species of Hiscobeccus evolved from older and smaller species of Rhynchotrema during the Late Ordovician.The current study proposes the first report of employing an artificial intelligence model based on neural networks to map a set of quantitative morphological measurements of the Rhynchotrema-Hiscobeccus lineage of North America to their locality and evolutionary trend. For this purpose, a total of 171 morphometric measurements of the Late Ordovician brachiopods from 11 localities of North America were divided into 114 training and validation samples and 57 testing sets. The input morphometric parameters of the studied brachiopods include shell length (L), shell width (W), shell thickness (T), sulcus depth (T1), sulcus maximum width (W1), sulcus floor width (W2), apical angle (AA), lamella-covered shell length (L1), lamella number (Ln). Artificial neural network tries to find a mathematical formulation between the mentioned morphometric parameters and their corresponding localities from North America. The results showed that the accuracy of the neural network approach in estimating the locality of the testing brachiopod samples is 81%. In the light of satisfactory results of neural networks, having a set of the morphometric data from the unseen Late Ordovician brachiopods, their localities can be estimated.

Symmetric Diblock Copolymers in Cylindrical Confinement: A Way to Chiral Morphologies?

We investigate the confinement-induced formation and stability of helix morphologies in lamella-forming AB diblock copolymers via large-scale, particle-based, single-chain-in-mean-field simulations. Such helix structures are rarely observed in bulk or thin films. Structure formation is induced by quenching incompatibility, χN, from a disordered morphology. If the surfaces of the cylindrical confinement do not prefer one component over the other, we observe that stacked lamellae, with their normals along the cylinder axis, are the preferred morphology. Kinetically, this morphology initially forms close to the cylinder surface, whereas the spontaneous, spinodal microphase separation in the cylinder's interior gives rise to a microemulsion-like morphology, riddled with defects and no directional order. Subsequently, the ordered morphology on the cylinder surface progresses inward, pervading the entire volume. In case that the cylindrical pore is only partially filled, the additional confinement along the cylinder axis generally gives rise to incommensurability between the equilibrium spacing of stacked lamellae and the cylinder height. To accommodate this mismatch, the lamella normals will tilt away from the cylinder axis and generate helices of lamellae on the surface of the cylinder. Again, this order progresses from the cylinder surface inward, generating a chiral morphology. Because the spacing between the internal AB interfaces decreases upon approaching the helix center, the concomitant stress results in a decrease in the number of lamellae and the formation of unique dislocation defects. This type of chiral defect morphology is reproducibly formed by the kinetics of structure formation in partly filled cylindrical pores with nonpreferential surfaces and may find applications in photonic applications.

Vibrotactile perception in Dupuytren disease

Purpose Dupuytren disease (DD) has been associated with enlarged Pacinian corpuscles (PCs) and with PCs having a greater number of lamellae. Based on these associations, we hypothesized that subjects with DD would have altered sensitivity to high-frequency vibrations and that the changes would be more prominent at 250 Hz, where healthy subjects demonstrate the highest sensitivity. Methods A novel device was created to deliver vibrations of specific frequencies and amplitudes to the fingers and palm. Using a Psi-marginal adaptive algorithm, vibrotactile perception thresholds (VPTs) were determined in 36 subjects with DD and 74 subjects without DD. Experiments were performed at 250 Hz and 500 Hz at the fingertip and palm. The VPTs were statistically analyzed with respect to disease status, age, gender, location tested, and frequency tested. Results We found that VPT increases with age, which agrees with findings by others. Women showed greater sensitivity (i.e. lower VPT) than men. Men exhibited lower sensitivity in DD versus healthy subjects, but the results were not statistically significant. In subjects with DD presenting unilaterally, the unaffected hand was more sensitive than the affected hand, in particular for a 250 Hz stimulus applied to the finger. Conclusions The data on vibration sensitivity obtained from a large group of subjects with and without DD present interesting trends that may serve as a useful reference to future DD researchers. Understanding additional symptoms of DD may facilitate development of novel diagnostic or prognostic protocols.