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BackgroundThe anterior hippocampus of individuals with early psychosis or schizophrenia is hyperactive, as is the ventral hippocampus in rodent models for schizophrenia risk. Hyperactive ventral hippocampal projections to extrahippocampal brain regions contribute to schizophrenia symptoms, but less is known about the functional effects of hyperactive projections within the hippocampal formation long axis. We approached this question by testing whether hyperactivation of ventral dentate gyrus (DG) mossy cells (MCs), which densely project intrahippocampally to the dorsal DG, influences spatial memory, a cognition dependent on intact dorsal DG function.MethodsIn CD-1 mice, we targeted dorsal DG-projecting ventral DG MCs using an adeno-associated virus intersectional strategy. In vivo fiber photometry recording of ventral DG MCs was performed during exploratory behaviors. We targeted excitatory chemogenetic constructs to ventral DG MCs and tested whether their hyperactivation impaired encoding in a spatial memory task.ResultsVentral DG MCs were activated during behavior related to environmental information gathering (rearing) but not during non-exploratory motor behaviors. Ventral DG MCs made functional monosynaptic inputs to dorsal DG granule cells, with chemogenetic activation of ventral DG MCs leading to increased activity of dorsal DG granule cells. Finally, chemogenetic activation of ventral DG MCs during the encoding phase of an object location memory task impaired retrieval 24 hours later, without effects on locomotion or other exploratory behaviors.ConclusionsThese data suggest that localized hippocampal hyperactivity may have longitudinal intrahippocampal functional consequences, supporting study of longitudinal circuits as targets to mitigate cognitive deficits associated with schizophrenia.

We carried out a comparative morphometric analysis of neurons in the cat dorsal lateral geniculate nucleus (dLGN) in frontal vs. sagittal slices. Using the SMI-32 antibody to non-phosphorylated domains of heavy-chain neurofilaments, the postnatal dynamic of soma parameters (area, roundness, orientation) of dLGN neurons was studied. Measurements were performed in kittens aged 0, 4, 10, 14, 21, 28, 34, 62, 123 days, and in adult cats. A comparison of data obtained in frontal vs. sagittal slices revealed the following significant differences: 1) the soma area of the immunopositive neurons was smaller in frontal vs. sagittal slices in all age groups, and this difference increased with age; 2) the soma orientation was also different in two cutting planes, and a significant age-related change in the soma orientation occurred only in the sagittal, but not frontal, plane. We assume that the difference in the soma area is due to the spatial arrangement of SMI-32-immunopositive neurons in the dLGN, because of which, in the sagittal plane, in contrast to the frontal, neuronal somas were cut parallel to their long axis. In turn, age-related changes in the soma orientation may reflect an internal rearrangement of the dLGN retinotopic organization with age.

Vibration receptors appear to be more necessary for web‐building spiders, but most knowledge of arachnid lyriform organs comes from the study of wandering spiders affected by ground vibrations. Here, we examined the fine structural aspects of the lyriform organs in the web‐building spider Nephila clavata using field emission scanning electron microscopy (FESEM) to fill the gap. The lyriform organ is found in all appendages, including the femur, patella, tibia, and metatarsal segments. A number of slit receptors of various sizes are distributed in the parallel orientation of the cuticle along the long axis. According to its fine structural characteristics, all lyriform organs of this spider are classified as a compound type with multiple cuticular slits. However, the number of cuticular slits per each lyriform organ varies considerably from a minimum of three to a maximum of 17. A total 35 pairs of lyriform organs were counted from an adult female spider. Except for small numerical variation in the 4th appendage, the distribution is remarkably constant within each appendage. Comparing the total number of cuticular slits per each appendage, the 3rd appendage has the highest number (85), but the 4th appendage shows the least number (63). Based on the total number of cuticular slits per leg segment, the patella segment seems to be the most sensitive to vibration reception in this orb‐web spider.

The anterior cruciate ligament (ACL) is an important knee stabilizer that prevents the anterior subluxation of the tibia. Extant crocodiles have two ACLs, the ACL major and minor, yet their functional roles are unclear. We here examined in-situ forces within the ACL major and minor in saltwater crocodiles (Crocodylus porosus) with a 6-degree-of-freedom robotic testing system under the following loading conditions: (a) 30 N anterior tibial load at 150°, 120°, and 90° knee extension; (b) 1 Nm internal/external torque at 150° and 120° knee extension; (c) 30 N anterior tibial load +1 Nm internal/external torque at 150° and 120° knee extension. The In-situ force in the ACL minor was significantly higher than that of the ACL major in response to anterior tibial load at 90° knee extension, and anterior tibial load + external torque at both 150° and 120° knee extension. Meanwhile, the force in the ACL major was significantly higher than that of the ACL minor in response to internal torque at 120° knee extension, and anterior tibial load + internal torque at 150° knee extension. The present results showed that the ACL minor and major of saltwater crocodiles have different functions. In response to anterior tibial load + internal/external torques, either of two ACLs reacted to opposing directions of knee rotation. These suggest that two ACLs are essential for walking with long axis rotation of the knee in crocodiles.

Manure belt poultry houses were widely used for egg production. However, reliable spatial distribution of airborne bacteria data from long-term on-farm monitoring in manure belt houses are scarce. In this study, the airborne bacteria were collected by the Andersen air microorganism sampler in a 4 tiers and an 8 tiers layer house, respectively. Results revealed that the airborne bacteria concentration range from 565 ± 247 CFU/m3 to 12,118 ± 883 CFU/m3 inside the 4 tiers poultry farmhouse and 459 ± 247 to 12,966 ± 884 CFU/m3 inside 8 tiers poultry farmhouse, respectively. The average airborne bacterial concentrations in the 4 and 8 tiers manure belt houses were 4,527 ± 2,509 and 5,489 ± 2,579 CFU/m3, respectively. Significant spatial variations of airborne bacteria concentration were observed for both houses. Spatial distribution of airborne bacteria concentration along the long axis direction can be divided into 3 regions: the low concentration region ( 10,000 CFU/m3), and airborne bacteria concentration was symmetrically distributed along the short axis direction inside both houses. We used 5 and 3 sampling locations to assess the average and maximum airborne bacterial concentration inside the manure belt houses, respectively. The average airborne bacteria concentration of 3 sampling locations was closest to the maximum concentration of both houses. It is more useful to use 3 sampling locations to monitor the change of the maximum airborne bacterial concentration inside the manure belt houses.

SUMMARYIn the obligate intracellular parasite, Toxoplasma gondii, the subpellicular microtubules (SPMTs) help maintain shape, while the apical conoid (also tubulin-based) is implicated in invasion. Here, we use cryo-electron tomography to determine the molecular structures of the SPMTs and the conoid-fibrils (CFs) in vitrified and detergent-lysed parasites. Subvolume densities from detergent-extracted parasites yielded averaged density maps at subnanometer resolutions, and these were related back to their architecture in situ. An intraluminal spiral (IS) lines the interior of the 13-protofilament SPMTs, revealing a preferred orientation of these microtubules relative to the parasite’s long axis. Each CF is composed of 9 tubulin protofilaments, that produce a comma-shaped cross-section, plus additional associated components. Conoid protrusion, a crucial step in invasion, is associated with an altered pitch of each CF. The use of basic building blocks of protofilaments and different accessory proteins in one organism, illustrates the versatility of these critical structures.

The hippocampal longitudinal axis has been linked to dissociated functional networks relevant to episodic memory. However, the organization of axis-dependent networks and their relation to episodic memory in aging remains less explored. Moreover, age-related deterioration of the dopamine (DA) system, affecting memory and functional network properties, might constitute a source of reduced specificity of hippocampal networks in aging. Here, we characterized axis-dependent large-scale hippocampal resting-state networks, their relevance to episodic memory, and links to DA in older individuals (n = 170, 64–68 years). Partial least squares identified 2 dissociated networks differentially connected to the anterior and posterior hippocampus. These overlapped with anterior–temporal/posterior–medial networks in young adults, indicating preserved organization of axis-dependent connectivity in old age. However, axis-specific networks were overall unrelated to memory and hippocampal DA D2 receptor availability (D2DR) measured with [11C]-raclopride positron emission tomography. Further analyses identified a memory-related network modulated by hippocampal D2DR, equally connected to anterior–posterior regions. This network included medial frontal, posterior parietal, and striatal areas. The results add to the current understanding of large-scale hippocampal connectivity in aging, demonstrating axis-dependent connectivity with dissociated anterior and posterior networks, as well as a primary role in episodic memory of connectivity shared by regions along the hippocampalaxis.

Rutaraphes Jałoszyński was proposed for an unusual species discovered on Shikoku, Japan. Rutaraphes shikokuensis Jałoszyński has a unique aedeagus, with an asymmetrical median lobe, lacking parameres, and the diaphragm to which the internal muscles are attached is situated not sub-medially, sub-basally, or basally, as in most genera of Stenichnini, but sub-apically, and nearly transverse in relation to the long axis of the aedeagus. It is here confirmed that this highly unusual structure was not a teratology in the sole known specimen, because the newly described Rutaraphes taiwanicus sp. n. shares similar genital structures. The new species occurs on northern Taiwan, and differs from R. shikokuensis in (among others) male modifications of the head. The new discovery extends the known range of Rutaraphes over 1500 km SW, suggesting that also the islands of the Ryukyus may be inhabited by this rare genus.

Studying retinal specializations offers insights into eye functionality and visual ecology. Using light microscopic techniques, including retinal whole-mounts, we investigated photoreceptor densities in the retina of the skate Leucoraja erinacea. We show that photoreceptors are not sized or oriented in the same way, and that they are not evenly distributed across the retina. There was a dorsally located horizontal visual streak with increased photoreceptor density, with additional local maxima in which densities were highest. Photoreceptors were longest and thinnest inside this visual streak, becoming shorter and thicker toward the periphery and toward the ventral retina. Furthermore, in the peripheral retinal parts, photoreceptors (particularly the outer segments) were noticeably tilted with respect to the retinal long axis. In order to understand how photoreceptors are tilted inside the eye, we used computerized tomography (CT) and micro-CT, to obtain geometrical dimensions of the whole skate eye. These CT/micro-CT data provided us with the outlines of the skate eye and the location of the retina and this enabled us to reconstruct how photoreceptors tilt in an intact eye. Findings were analyzed relative to previously published ganglion cell distributions in this species, showing a posteriorly located retinal area with photoreceptor: ganglion cell convergence as low as 39:1. Some peripheral areas showed ratios as high as 391:1. We frame our findings in terms of the animal's anatomy: body and eye shape, specifically the location of the tapetum, as well as the visual demands associated with lifestyle and habitat type. A speculative function in polarization sensitivity is discussed.

In this study, seeds of 10 species of epiphytic orchids were examined using light and scanning electron microscope. Quantitative and qualitative characters were analyzed. All the presently investigated seeds showed are transparent with visible embryo and remarkable embryo color variations (such as pale yellow, light yellow, shiny yellow to yellow, orange, and white). The species showed two groups in seed shape (fusiform and filiform), prolate and oval-shaped embryo, positioned at the center of the long axis and near apical pole. Embryo in prolate shaped and near apical pole position was only in D. antennatum. Based on our investigation, there are variations in seed and embryo volume as well as percentage air space in different taxa of orchids. The highest air space percentages were found in D. leporinum. According to the ornamentation of testa cells, 3 types of seeds were discovered in this genus. Additionally, the clear variation in the testa ornamentation pattern includes the species of D. leporinum, where the testa cells were in the medial regular rectangles, but in the apical and basal pole they are polygonal and irregularly oriented; the testa cells of D. antennatum are polygonal and irregularly oriented and those of D. purpureum are longitudinally oriented with regular rectangles.

In the natural conditions early-spring period development of Galanthus nivalis L., the leaves germination from bulbs was carried out in the soil surface layer, mainly, covered with snow, so the leaves were exposed to low soil temperatures. It was found, that at the leaf germination stage, when exposed to minus soil temperature, the mitochondria were predominantly elongated, that is, functionally active. Under the influence of positive temperature, the mitochondria form changed to a round one, which indicates their transition to low functional activity. A similar tendency was manifested even during the budding stage, in particular, when the soil temperature was lowered to an average of –3.47 °C, the mitochondria changed their form to an elongated one, that is, they passed into an active functional state. Wherein, the temperature of the leaves was higher by 3.84 °C compared to the soil. At the stages of germination and budding of G. nivalis under natural conditions, a direct correlation was found between the soil surface layer temperature and the leaves temperature, and at the flowering stage this relation was reverse. During the flowering stage, despite the influence of predominantly positive soil temperatures, leaves growth was significantly slowed, and their temperature was only slightly higher by 0.38 °C compared to the soil. At the same time, the mitochondria changed their shape to a round one. Thus, the increase in their long axis at different stages in spring development, are aimed at adapting to influence low temperatures of the soil surface layer.

Cervical vertebrae of six horned dinosaurs from the Upper Cretaceous of Mongolia, which are identified as Protoceratops andrewsi are examined. It is shown that vertebrae of the same serial number essentially differ in different specimens. The differences concern, for example, the shape of the vertebral centra, proportions of the centra and neurapophyses, inclination of pedicles of the neural arch and long axis of the diapophyseal base relative to the longitudinal axis of the centrum. Comparison has shown that available sample contains representatives of at less four morphotypes.

The lateral ligament complex of the ankle is involved in a large proportion of ankle sprains. The calcaneofibular ligament (CFL) is often involved in severe injuries. The purpose of this study was to evaluate the anatomical variation and laterality of the CFL to improve our understanding of the mechanisms of CFL-related injuries. This study utilized 110 paired ankles from 55 formalin-fixed Japanese cadavers (33 male and 22 female). The length and width of the CFL and the angle created by the CFL and long axis of the fibula (CF angle) were measured after exposing the CFL by careful dissection from the surrounding tissues. The results revealed that each parameter exhibited a wide range of values and showed unique patterns of frequency distribution, among which only the length was normally distributed. Among the parameters, only the CF angle showed no significant correlation with the other parameters. Analysis of laterality revealed that the mean left CF angle was significantly greater than the value on the opposite side (p

The elongated structure of the hippocampus is critically involved in brain functions of profound importance. The segregation of functions along the longitudinal (septotemporal or dorsoventral) axis of the hippocampus is a slowly developed concept and currently is a widely accepted idea. The segregation of neuroanatomical connections along the hippocampal long axis can provide a basis for the interpretation of the functional segregation. However, an emerging and growing body of data strongly suggests the existence of endogenous diversification in the properties of the local neural network along the long axis of the hippocampus. In particular, recent electrophysiological research provides compelling evidence demonstrating constitutively increased network excitability in the ventral hippocampus with important implications for the endogenous initiation and propagation of physiological hippocampal oscillations yet, under favorable conditions it can also drive the local network towards hyperexcitability. In addition, important specializations in the properties of dorsal and ventral hippocampal synapses may support an optimal signal processing that contributes to the effective execution of the distinct functional roles played by the two hippocampal segments.

Hair fibres show wide diversity across and within all human populations, suggesting that hair fibre form and colour have been subject to much adaptive pressure over thousands of years. All human hair fibres typically have the same basic structure. However, the three-dimensional shape of the entire fibre varies considerably depending on ethnicity and geography, with examples from very straight hair with no rotational turn about the long axis, to the tightly sprung coils of African races. The creation of the highly complex biomaterials in hair follicle and how these confer mechanical functions on the fibre so formed is a topic that remains relatively unexplained thus far. We review the current understanding on how hair fibres are formed into a nonlinear coiled form and which genetic and biological factors are thought to be responsible for hair shape. We report on a new GWAS comparing low and high curl individuals in South Africa, revealing strong links to polymorphic variation in trichohyalin, a copper transporter protein CUTC and the inner root sheath component keratin 74. This builds onto the growing knowledge base describing the control of curly hair formation.

The formal ichnotaxonomic assignment of a new ichnogenus and ichnospecies, Reniformichnus katikatii, is presented based on the holotype and several field specimens from the Lower Triassic Katberg Formation in the main Karoo Basin of South Africa. The holotype is an inclined, burrow cast with bilobate base and reniform cross-section. Its width ranges from 12.6 to 14.7 cm, and its height is 5 to 7.4 cm resulting in an aspect ratio of 1.89 to 2.74. The surface preserves 70–180 mm long ridges running parallel to the long axis of the burrow on the upper parts of the walls and lower parts of the dorsum and shorter ridges (average length ∼27 mm) are preserved on the more ventral areas in two opposite orientations, cross-cutting each other in a rhomboid pattern. Burrow fills are passive and consist of slightly bedded, laminated, or massive clastic rocks that are coarser than the host mudstones. The burrow casts are isolated, never occurring in clusters. This simple burrow shows no evidence for branching, ...

Ultraviolet light traps are commonly used to manage house flies in indoor situations. Many indoor traps are longer than their 46-cm fluorescent tubes and have glue boards to capture attracted flies. Smaller traps have been sold to use in homes and small rooms, but few if any trap evaluations can be found in the literature. One trap, the DynaTrap Flylight DT-3009 (DTFL) has become quite common and a performance evaluation between it and an open-front commercial trap seemed warranted. Evaluations were conducted at the USDA-ARS-CMAVE laboratory in Gainesville, FL. The DTFL and the Gardner GT-200 open-front trap were evaluated individually and then in pairs. Traps were placed approximately 90 cm above the floor at the edge of a 2.4- × 0.76-m wide counter. Traps tested individually were centered on the long axis of the counter. For paired tests, traps were placed approximately 2.1 m apart. Fifty mixed-sex, 3- to 5-d-old house or stable flies were released and counts of captured flies were made after 1, 4, and 24 h. In individual tests, the DTFL and the GT-200 captured 38 and 76% of the house flies, respectively, and 3 and 18% of the stable flies, respectively, after 4 h. At 4 h in paired tests, the DTFL and the GT-200 captured 3 and 66% of the house flies, respectively, and 2 and 16% of the stable flies, respectively. Depending on the intended use, either trap was considered efficacious in capturing house flies when used alone. Differences in trap performance are discussed.

Including open alleys at ends of plots is a common practice when field-testing foliar fungicides used in corn production. Open alleys facilitate movement of workers and equipment between plots during spray application. Open alleys affect crop yield estimates in small plots typically used in replicated, randomized experimental designs, because of reduced interplant competition. However, no published research has tested whether the alley effect interacts with fungicide to bias the assessment of the agronomic effects of the latter. We tested this hypothesis over 2 years by evaluating yield with and without application of Headline AMP (containing pyraclostrobin and metconazole) plus nonionic surfactant applied once at VT/R1 in 7.6-m plots separated on their ends by 1.5-m alleys free of aboveground vegetation. In each plot, data were collected from seven subplots, each measuring 1.09 m of row-length and running parallel to the long axis of the plot. Consistent with previous reports, yields of subplots were substantially higher toward plot ends than in the central areas of plots. Surprisingly, a significant (P < 0.10) fungicide × subplot interaction was observed in both experiments, indicating that the yield response from fungicide depended on subplot position within the plot. However, yield differences due to fungicide were trivial when comparing regression-based yield estimates from all seven subplot positions to those obtained from only the centermost three subplot positions. Our study does not lend support to the hypothesis that the open-alley design creates a meaningful bias in assessment of treatment effects due to foliar fungicides in corn. However, additional research on this question is warranted, given the complexities of comparing results in large-scale plots vs. small plots, the limitations of our study, and the widespread use of fungicides on field corn in the United States.

The present study was carried out on the cranial lumbar vertebrae (L1, L2 and L3) of adult Blue bull (Boselaphus tragocamelus) of either sex. It was revealed that the centrum of cranial lumbar vertebrae was constricted in the middle, but expanded at either end. They presented a rudimentary ventral crest. The intervertebral foramina were often double in the cranial part of the series and were very large further back. The transverse process was a long plate of bone that spread out laterally at right angles from the centrum, being slightly bent forward. The borders of the transverse processes were thin, irregular and presented projections of variable size and form. The dorsal supraspinous processes were broad and flattened plates of bone. These processes were relatively low, wide and perpendicular to the long axis of the vertebrae. The articular processes were well developed and placed further apart than in the thoracic region. They were large and their facets were strongly curved. The mamillary processes were fused with the cranial articular processes and were thick and tuberous. The cranial articular processes were concave and directed medially, whereas the caudal ones were convex and directed laterally. Biometrical observations on different parameters of cranial lumbar vertebrae reflected significance (P less than 0.05) differences between the sexes of this species.

All mammalian infants suckle, a fundamentally different process than drinking in adults. Infant mammal oropharyngeal anatomy is also anteroposteriorly compressed and becomes more elongate postnatally. While suckling and drinking require different patterns of muscle use and kinematics, little insight exists into how the neuromotor and anatomical systems change through the time that infants suckle. We measured the orientation, activity and contractile patterns of five muscles active during infant feeding from early infancy until weaning using a pig model. Muscles not aligned with the long axis of the body became less mediolaterally orientated with age. However, the timing of activation and the contractile patterns of those muscles exhibited little change, although variation was larger in younger infants than older infants. At both ages, there were differences in contractile patterns within muscles active during both sucking and swallowing, as well as variation among muscles during swallowing. The changes in anatomy, coupled with less variation closer to weaning and little change in muscle firing and shortening patterns suggest that the neuromotor system may be optimized to transition to solid foods. The lesser consequences of aspiration during feeding on an all-liquid diet may not necessitate the evolution of variation in neuromotor function through infancy.

Egg turning is a vital part of the incubation process in many bird species. However, the quality and quantity of turning can differ between species. Commercial incubators with domestic fowl automatically move the eggs that are set pointed end down, 45° either side from the vertical every hour. However, goose eggs are not set pointed end down vertically, but horizontally with the long axis parallel to the horizontal plain, i.e., laid flat on wire trays and turned as described above. With this method of incubation the down side of the goose egg will not find itself facing upwards during the incubation process if the eggs do not get additional hand turning. It was suggested (Bogenfurst, 2004) that goose eggs lying flat as above but at an angle of 4560° on the trays, do not require manual turning. This study used eggs from one year old geese that were in addition hand turned (around the short or the long axis of the egg by 180°) once per day from d 10-26 of incubation. Turning was in the opposite manner on alternative days. Their hatchability was compared with eggs that had no hand turning. Fertility was >85.42% in all egg Groups. Overall, the hatchability of fertile goose eggs in Group C (no manual turning; 44.12%) was significantly lower than those of Groups A (manual turning around long axis; 63.77%; p = 0.002) and B (manual turning around short axis; 61.94%; p = 0.005). Manual turning did increased the hatchability of goose eggs with no significant difference between the short or long axis turning Groups.

The hydranth of the gymnoblastic hydroid Syncoryne tenella is invested by a cuticle approximately 530 mμ thick which is continuous with the periderm of the hydrocaulus. The ectodermal cells of the hydranth possess regularly spaced microvilli orientated with their long axis perpendicular to the ectodermal surface. The microvilli project into the cuticle, and probably serve to anchor the cuticle to the ectoderm. In the hydrocaulus the periderm is loosely applied to the ectoderm: in this region microvilli are absent from ectodermal cells. The periderm is a layered structure composed of finely filamentous material. No structural basis is found for the previously reported differential staining of peridermal layers in the hydrocaulus.

Abnormal filamentous aggregates that are formed by tangled tau protein turn out to be classic amyloid fibrils, meeting all the criteria defined under the fuzzy oil drop model in the context of amyloid characterization. The model recognizes amyloids as linear structures where local hydrophobicity minima and maxima propagate in an alternating manner along the fibril&rsquo, s long axis. This distribution of hydrophobicity differs greatly from the classic monocentric hydrophobic core observed in globular proteins. Rather than becoming a globule, the amyloid instead forms a ribbonlike (or cylindrical) structure.

Four heteropod lizard trackways discovered in the Hasandong Formation (Aptian-early Albian), South Korea assigned to Sauripes hadongensis, n. ichnogen., n. ichnosp., which represents the oldest lizard tracks in the world. Most tracks are pes tracks (N = 25) that are very small, average 22.29 mm long and 12.46 mm wide. The pes tracks show “typical” lizard morphology as having curved digit imprints that progressively increase in length from digits I to IV, a smaller digit V that is separated from the other digits by a large interdigital angle. The manus track is 19.18 mm long and 19.23 mm wide, and shows a different morphology from the pes. The predominant pes tracks, the long stride length of pes, narrow trackway width, digitigrade manus and pes prints, and anteriorly oriented long axis of the fourth pedal digit indicate that these trackways were made by lizards running bipedally, suggesting that bipedality was possible early in lizard evolution.

We show in a comparative analysis that distinct retinal specializations in insect ocelli are much more common than previously realized and that the rhabdom organization of ocellar photoreceptors is extremely diverse. Hymenoptera, Odonata and Diptera show prominent equatorial fovea-like indentations of the ocellar retinae, where distal receptor endings are furthest removed from the lens surface and receptor densities are highest. In contrast, rhabdomere arrangements are very diverse across insect groups: in Hymenoptera, with some exceptions, pairs of ocellar retinular cells form sheet-like rhabdoms that form elongated rectangular shapes in cross-section, with highly aligned microvilli directions perpendicular to the long axis of cross-sections. This arrangement makes most ocellar retinular cells in Hymenoptera sensitive to the direction of polarized light. In dragonflies, triplets of retinular cells form a y-shaped fused rhabdom with microvilli directions oriented at 60° to each other. In Dipteran ocellar retinular cells microvilli directions are randomised, which destroys polarization sensitivity. We suggest that the differences in ocellar organization between insect groups may reflect the different head attitude control systems that have evolved in these insect groups, but possibly also differences in the mode of locomotion and in the need for celestial compass information.

In diseased hearts, impaired muscle within the hearts is passively stretched by contractions of the more viable neighboring muscle during the contraction phase. We investigated whether in the myocardium with nonuniform contraction such passive stretch regionally generates ROS within the stretched region and exacerbates arrhythmias. In trabeculae from rat hearts, force, intracellular Ca2+, and membrane potential were measured. To assess regional ROS generation, the slope of the change in the 2′,7′-dichlorofluorescein fluorescence (DCFslope) was calculated at the each pixel position along the long axis of trabeculae using DCF fluorescence images. Ca2+ waves and arrhythmias were induced by electrical stimulation. A H2O2 (1 mmol/L) jet regionally increased the DCFslope within the jet-exposed region. A blebbistatin (10 μmol/L) jet caused passive stretch of the muscle within the jet-exposed region during the contraction phase and increased the DCFslope within the stretched region, the velocity of Ca2+ waves, and the number of beats after electrical stimulation (0.2 μmol/L isoproterenol), while 3 μmol/L diphenyleneiodonium (DPI), NADPH oxidase inhibitor, decreased them. A jet of a solution containing 0.2 mmol/L H2O2 in addition to 10 µmol/L blebbistatin also increased them. A H2O2 jet within the region where Ca2+ waves propagated increased their velocity. In the myocardium with nonuniform contraction, passive stretch of the muscle by contractions of the neighboring muscle regionally increases ROS within the stretched region, and the regional ROS exacerbates arrhythmias by activating the propagation of Ca2+ waves.

Changes in the relative importance of the 27 component functional groups (FGs) of seagrass-associated macrobenthos were assessed up the long axis of an estuarine system. Although previously observed division of the estuary into two sections with respect to species diversity was confirmed, this did not correspond to any functional compartmentalisation. Functionally, division was into the terminal extremes and the large intervening marine/lagoonal/lower-estuarine zone, within which no linear segregation of sites occurred. 40% of individual FGs in the latter showed no variation at all, and variation in the remainder was only axially related in two cases, one positive and one negative. Overall structure of the dominant FGs at each locality remained uniform, although rank orders of proportional importance varied widely. Only one major marine/lagoonal FG failed to penetrate the upper estuary at the time of sampling. Estuarine components may change spatially, sometimes dramatically, but overall functional pattern shows considerably less change than the species numbers usually used in characterisation.

Abundant well-preserved tubular fossils of caddisfly (Insecta: Trichoptera) larval cases are reported from the Early Cretaceous Madongshan and Naijiahe formations of the Liupanshan Basin, Ningxia Province, western China. Most cases were mainly preserved in life position and densely packed in various layers. Individual cases in each layer tended to be same in size and were erect and parallel to one another and open at both ends. In a transverse section cut perpendicular to the long axis of the cases, individual case appears to form a rounded ring. Small cases are elliptic in a cross-section oblique to the long axis of the cases. Tube walls are nearly subparallel to one another in longitudinal section with both ends being open. The caudal end of the case slightly tapers and usually points downward. The cases were closely packed, almost touching with one another and lacking bifurcate or connecting structure. The overwhelming majority of cases were partially or fully filled with calcite. The case wall embraces a medium particle layer flanked by inner and outer organic layers. Individual particles are ovate in outline and comprise cryptocrystalline or ganic pellets. SEM imaging shows that those pellets are sub-cylindrical in outline and elliptic in cross section, and are made primarily of calcium carbonate. All features observed justify the assignment of the Liupanshan caddisfly cases to ichnogenus Coprindusia. The extinct insect Ningxiapsyche fangi was found in association with the Liupanshan caddisfly larval cases, and thus could be the candidate of the potential trace-maker.

It has been proposed that forces resulting from the physical exclusion of macromolecules from the bacterial nucleoid play a central role in organizing the bacterial cell, yet this proposal has not been quantitatively tested. To investigate this hypothesis, we mapped the generic motion of large protein complexes in the bacterial cytoplasm through quantitative analysis of thousands of complete cell-cycle trajectories of fluorescently tagged ectopic MS2-mRNA complexes. We find the motion of these complexes in the cytoplasm is strongly dependent on their spatial position along the long axis of the cell, and that their dynamics are consistent with a quantitative model that requires only nucleoid exclusion and membrane confinement. This analysis also reveals that the nucleoid increases the mobility of MS2-mRNA complexes, resulting in a fourfold increase in diffusion coefficients between regions of the lowest and highest nucleoid density. These data provide strong quantitative support for two modes of nucleoid action: the widely accepted mechanism of nucleoid exclusion in organizing the cell and a newly proposed mode, in which the nucleoid facilitates rapid motion throughout the cytoplasm.

Aims The development of communicating modular cardiac rhythm management systems relies on effective intrabody communication between a subcutaneous implantable cardioverter-defibrillator (S-ICD) and a leadless pacemaker (LP), using conducted communication. Communication success is affected by the LP and S-ICD orientation. This study is designed to evaluate the orientation of the LP and S-ICD in canine subjects and measure success and threshold of intrabody communication. To gain more human insights, we will explore device orientation in LP and S-ICD patients. Methods and results Canine subjects implanted with a prototype S-ICD and LP (both Boston Scientific, MA, USA) with anterior-posterior fluoroscopy images were included in this analysis. For comparison, a retrospective analysis of human S-ICD and LP patients was performed. The angle of the long axis of the LP towards the vertical axis of 0°, and distance between the coil and LP were measured. Twenty-three canine subjects were analysed. Median angle of the LP was 29° and median distance of the S-ICD coil to LP was 0.8 cm. All canine subjects had successful communication. The median communicating threshold was 2.5 V. In the human retrospective analysis, 72 LP patients and 100 S-ICD patients were included. The mean angle of the LP was 56° and the median distance between the S-ICD coil and LP was 4.6 cm. Conclusion Despite the less favourable LP orientation in canine subjects, all communication attempts were successful. In the human subjects, we observed a greater and in theory more favourable LP angle towards the communication vector. These data suggests suitability of human anatomy for conductive intrabody communication.

Increased place field size and signal autocorrelation along the dorsoventral hippocampal axis in rodents are considered a fundamental aspect of hippocampal organization, yet such evidence is lacking in humans. Using fMRI, we report corresponding evidence of increasing neural similarity from posterior to anterior hippocampus (dorsoventral homologues) in humans. These findings help account for observed shifting in representational granularity, from global context (anterior) to local details (posterior), along the hippocampal axis.

The present study was conducted in six adult Deccani sheep and Bidri goats to know the histological structure of endocrine pancreas. Islets were distributed irregularly within the exocrine portion of the gland. The reticular fibers formed a boundary between the endocrine and exocrine portion. The islets were oval, round or irregular in shape and were classified into small, medium and large, based on their size on its long axis. Three types of cells α, β and δ were identified within the islets by special stains like Masson’s trichrome, Modified aldehyde fuchsin stain method and Maldonado’s method.

Fish live in a complex world and must actively adapt their swimming behavior to a range of environments. Most studies of swimming kinematics focus on two-dimensional properties related to the bending wave that passes from head to tail. However, fish also twist their bodies three dimensionally around their longitudinal axis as the bending wave passes down the body. We measured and characterized this movement, which we call ‘wobble’, in six species of elongate fishes ( Anoplarchus insignis , Xiphister mucosus , Lumpenus sagitta , Pholis laeta , Apodichthys flavidus and Ronquilus jordani ) from three different habitats (intertidal, nearshore and subtidal) using custom video analysis software. Wobble and bending are synchronized, with a phase shift between the wobble wave and bending wave. We found that species from the same habitats swim in similar ways, even if they are more closely related to species from different habitats. In nearshore species, the tail wobbles the most but, in subtidal and intertidal species, the head wobbles more than or the same as the tail. We also wanted to understand the relationship between wobble and the passive mechanics of the fish bodies. Therefore, we measured torsional stiffness and modulus along the body and found that modulus increases from head to tail in all six species. As wobble does not correlate with the passive properties of the body, it may play a different role in swimming behavior of fishes from different habitats.

Each septum of the phragmocone in the Jurassic belemnitid Magateuthis is composed of a thick, lamello-fibrillar, nacreous layer and a thin, chitinous layer, here termed the additional chitinous layer, which covers the aboral surface of the septum. The nacreous and additional chitinous layers continue from the septum into the septal neck. The inner surface of the septal neck is covered by a thick, tubular, conchiolin layer that originates on the septal surface around the siphuncle. The connecting ring is composed of three conchiolin layers with high elasticity: the additional chitinous layer that fuses with the tubular chitinous layer and continues into the connecting ring, and an outer chitinous layer that is a non-calcified continuation of the nacreous layer of the septal neck and is often destroyed by diagenesis. As seen in higher magnification, the tubular layer consists of tightly packed tubes with chitinous walls that are oriented at right angles to the long axis of the siphuncle. At about half of it...

Anterior-posterior (AP) patterning is an essential process that requires the generation of large amounts of positional information to properly specify many distinct cell fates along the long axis of the insect embryo. While the general molecular basis of this process has long been known in the fly Drosophila, detailed understanding of this process is still emerging in other insect species. What is now clear is that this process in extremely labile, and distinct AP patterning programs can exist even within a single species. This review presents recent progress on this topic in an attempt to synthesize the disparate data and provide an outlook on the future of the field.

A new fossil liverwort species Marchantites huolinhensis R.Y. Li & B.N. Sun sp. nov., is founded based on twenty-seven fossil specimens collected from the Lower Cretaceous Huolinhe Formation in Huolinhe Basin of Inner Mongolia, China. The fossil liverwort is characterized by thalloid and prostrate gametophyte, and elliptical–circular gemma cups. Thallus is strap-like, dichotomously branched and with prominent costa. Imbricate ventral scales are in two rows and smooth and unicellular rhizoids are produced in considerable numbers around the costa. Cells on prominent costa are elongated and parallel to the long axis of the thallus. The relatively complete gametophyte, gemma cups, ventral scales and rhizoids indicate that they were likely to be autochthonously buried in dysoxic or anoxic silty deposits. Marchantites huolinhensis, along with other fossil records from other localities and age, indicates that the Marchantiales was already diverse in the Early Cretaceous and its morphological evolution is very slow.

Purpose: To describe the “crocodile technique”, a new ophthalmic surgery technique for removing subretinal proliferative tissue (SPT) associated with retinal detachment. Materials and Methods: Subjects were 21 patients who had retinal detachment with SPT. Their follow-up terms were all greater than 3 months. We undertook the crocodile technique during their subretinal surgery. The crocodile technique is a new ophthalmic technique for removing SPT using vitreous forceps, without using subretinal forceps, in small-gauge vitrectomy. After performing sufficient peripheral vitrectomy, a small intentional retinal tear was created above the SPT. The SPT was then stabilized while grasped by vitreous forceps in the subretinal space. The vitreous forceps were then rotated on their long axis, such that the SPT was rolled around the vitreous forceps in the subretinal space. Results: The crocodile technique was successfully performed without enlarging the intentional retinal tear or creating new retinal tears, in all subjects. The retina was successfully reattached in all subjects, postoperative average visual acuity was improved after surgery, and postoperative redetachment did not occur in any patients.

The development and transfer character of the secretory glands developing ,on the stipules (from node I to X) in Vicia faba L. was investigated. It was found that the state of developmental and functional maturity is reached by them in nodes IV-VI from the shoot apex. In mature glands the characteristic ingrowths from the cell wall to the interior of the protoplast develop to different extents (number, size and shape) in the particular gland cells. Their most intensive development up to the formation of labyrinths was observed in the outher walls of the head, and particularly in the cells of its upper tier. In all the other cells of the gland (up to the subepidermal one) less developed ingrowths occur on the transverse walls and even less along the long axis of the gland. This arrangement of the ingrowths shows the direction of flow of secretive substances.

Engineers can learn from nature for inspirations to create new designs. The internal structure of lotus roots with several oval holes was studied in this paper for engineering inspirations. The structural performance of lotus roots under outside water pressure was simulated and compared with various cross-sectional areas. The distribution of stresses in the cross-sectional area of lotus roots was analysed and presented. It was found that the maximum compressive stresses in the cross-sectional area of lotus roots were occurring at the long axis ends of the holes. This was very different from that of circular holes. Further analysis on the triaxiality factors revealed that the cross-sectional area of the lotus root resulted in large areas of high triaxiality factors. The resulting hydrostatic stress in the cross-sectional area of lotus root ranges from zero to 2.7 times the applied outside pressure. In contrast, the hydrostatic stress in a cylindrical cross-sectional area is a fixed value. The study showed that the lotus root and the orientation of the oval holes could be mimicked in the design of new structures, for example, underwater pipes and vessels.

This study aimed to establish a shrimp eyeball-weight relationship model for Litopenaeus vannamei using machine vision technology. A total of 295 shrimp were sampled from a recirculating aquaculture system (RAS). The long-axis length (d), body length (L), and body weight (W) of each individual was measured. The long axis length of the shrimp eyeball was identified and measured using machine vision technology. Continuous fitting and piecewise fitting models were used to construct the eyeball-weight relationship model for L. vannamei. The continuous fitting relationship model was described as: W = 38.865d2.7914, while the piecewise model was described as: d

The study was conducted on 12 apparently healthy adult animals, 6 Zovawk (Mizo local pig) and 6 Large White Yorkshire pig. Both the testes were reddish white in colour. They were elliptical and rounded to oval in shape in Zovawk and Large White Yorkshire pig. The long axis of the testis was obliquely in Zovawk and slightly horizontal in Large White Yorkshire pig. The different biometrical values with regard to weight, length, width and thickness were found to be higher in left side of testes than the right side in Zovawk and Large White Yorkshire Pig. The average Net testicular weight of the right and left testicles of adult Zovawk was 42.85±4.88 gm and 43.93±3.54 gm and that of Large White Yorkshire was 259.57±32.22 gm and 269.52±27.22 gm, respectively. These biometrical parameters were found to be low in Zovawk as compare to Large White Yorkshire pig.

Cells in a developing embryo have no direct way of "measuring" their physical position. Through a variety of processes, however, the expression levels of multiple genes come to be correlated with position, and these expression levels thus form a code for "positional information." We show how to measure this information, in bits, using the gap genes in the Drosophila embryo as an example. Individual genes carry nearly two bits of information, twice as much as would be expected if the expression patterns consisted only of on/off domains separated by sharp boundaries. Taken together, four gap genes carry enough information to define a cell's location with an error bar of ~1 along the anterior/posterior axis of the embryo. This precision is nearly enough for each cell to have a unique identity, which is the maximum information the system can use, and is nearly constant along the length of the embryo. We argue that this constancy is a signature of optimality in the transmission of information from primary morphogen inputs to the output of the gap gene network.

If Wolff's law is valid, then quantifying the three-dimensional architecture of trabecular bone, specifically 3D principal trabecular orientation (3D-PTO), can reveal joint loading direction among different taxa. This study measured the architecture of trabecular bone in the 3rd metacarpal head of humans and chimpanzees, and then tested their association with expected joint loading direction. We postulate that since chimpanzees, unlike humans, directly load their metacarpal bones during knuckle-walking, trabecular structure in the dorsal aspect of the 3rd metacarpal head will be significantly more organized and robust in chimpanzees. To test this hypothesis, we micro-CT scanned the 3rd metacarpal from 11 chimpanzees and 12 humans. Three 6 mm volumes of interest (VOI; palmar, center and dorsal) were selected and trabecular bone properties and 3D-PTO were measured. The results revealed many similarities between humans and chimpanzees: in both taxa the dorsal VOI demonstrated the lowest bone volume fraction (BV/TV), the most rod-like trabecular structure, the fewest and thinnest trabeculae, and low organization of the trabecular architecture (degree of anisotropy). Nevertheless, 3D-PTO in the dorsal VOI differed significantly between humans and chimpanzees. While 3D-PTO in humans was clustered together and aligned nearly along the bone long axis, in chimpanzees 3D-PTO was divided into two distinct groups and aligned with an angle toward either the medial or lateral orientations. Our results suggest that loading effects on trabecular bone properties such as BV/TV might be partially constrained by genetic factors. On the other hand, 3D-PTO is continually affected by active loading (i.e., modeling) and thus may serve as a useful tool to infer differences in joint loading directions.

Phagocytes, predatory cells of the immune system, continuously probe their cellular microenvironment on the hunt for invaders. This requires prey recognition followed by the formation of physical contacts sufficiently stable for pickup. Although immune cells must apply physical forces to pick up their microbial prey, little is known about their hunting behavior preceding phagocytosis because of a lack of appropriate technologies. To study phagocyte hunting behavior in which the adhesive bonds by which the prey holds on to surfaces must be broken, we exploited the use of microrobotic probes to mimic bacteria. We simulate different hunting scenarios by confronting single macrophages with prey-mimicking micromagnets using a 5-degree of freedom magnetic tweezers system (5D-MTS). The energy landscape that guided the translational and rotational movement of these microparticles was dynamically adjusted to explore how translational and rotational resistive forces regulate the modes of macrophage attacks. For translational resistive prey, distinct push-pull attacks were observed. For rod-shaped, nonresistive prey, which mimic free-floating pathogens, cells co-aligned their prey with their long axis to facilitate pickup. Increasing the rotational trap stiffness to mimic resistive or surface-bound prey disrupts this realignment process. At stiffness levels on the order of 105 piconewton nanometer radian-1, macrophages failed to realign their prey, inhibiting uptake. Our 5D-MTS was used as a proof-of-concept study to probe the translational and rotational attack modes of phagocytes with high spatial and temporal resolution, although the system can also be used for a variety of other mechanobiology studies at length scales ranging from single cells to organ-on-a-chip devices.

Water mites Limnochares aquatica (L., 1758) during maintenance in the laboratory for a long period of time in constant conditions periodically produced certain whitish flocculent material consisting of long rigid unbranched tube-like threads 1.3 ± 0.3 µm in diameter crossing freely. These threads were studied using light-optical as well as transmission electron microscopical and scanning electron microscopical methods. Microbiological staining was also applied to the threads to exclude their bacterial or fungal origin. The thread wall is built of fine fibrils arranged at different angles to the long axis of threads that is reflected in a certain stratification of the wall. Threads are mostly hollow or may contain electron-dense homogeneous material. No cell components are present in the thread composition. Numerous dermal glands with their small slit-like orifice scattered throughout the mite body surface are thought to produce these threads. Most probably the thread formation is a reaction of mit...

Non-POU domain-containing octamer-binding protein (NONO, a.k.a. p54nrb) is a central player in nuclear gene regulation with rapidly emerging medical significance. NONO is a member of the highly conservedDrosophilabehaviour/human splicing (DBHS) protein family, a dynamic family of obligatory dimeric nuclear regulatory mediators. However, work with the NONO homodimer has been limited by rapid irreversible sample aggregation. Here, it is reported that L-proline stabilizes purified NONO homodimers, enabling good-quality solution small-angle X-ray structure determination and crystallization. NONO crystallized in the apparent space groupP21with a unique axis (b) of 408.9 Å and with evidence of twinning, as indicated by the cumulative intensity distributionLstatistic, suggesting the possibility of space groupP1. Structure solution by molecular replacement shows a superhelical arrangement of six NONO homodimers (or 12 inP1) oriented parallel to the long axis, resulting in extensive noncrystallographic symmetry. Further analysis revealed that the crystal was not twinned, but the collected data suffered from highly overlapping reflections that obscured theL-test. Optimized data collection on a new crystal using higher energy X-rays, a smaller beam width and an increased sample-to-detector distance produced non-overlapping reflections to 2.6 Å resolution. The steps taken to analyse and overcome this series of practical difficulties and to produce a biologically informative structure are discussed.

We describe fossil kogiid periotics from the Lower Pliocene upper Bone Valley Formation in central Florida and the Lower to Upper Pliocene Yorktown Formation at Lee Creek Mine, North Carolina. The fossils show diagnostic characters that identify them as belonging to Kogiidae, such as three spines in the anterior process, presence of an incudal process, and a posterior process oriented along the long axis of the bone. Morphological comparisons and morphometric and statistical analyses of periotic proportions confirm the presence of a large and a small morphotype within the sample. The large morphotype (mean length = 39.76 mm) belongs to an unknown kogiid that occurs in both formations, whereas the small morphotype (mean length = 28.64 mm), referred to aff. Kogia sp., occurs only in the Yorktown Formation. The cooccurrence of two taxa in North Carolina may represent one of the earliest evidences of sympatry in kogiids and may demonstrate that this ecological behavior has been part of the natural history of this group at least since the deposition of the Yorktown Formation at Lee Creek (∼4.8–3.1 Ma). In addition, the occurrence of the large morphotype in the upper Bone Valley Formation, herein reported for the first time, shows that we are still far from understanding the diversity of marine mammals of that formation and that revision of newly acquired material is necessary. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP Citation for this article: Vélez-Juarbe, J., A. R. Wood, and C. Pimiento. 2016. Pygmy sperm whales (Odontoceti, Kogiidae) from the Pliocene of Florida and North Carolina. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1135806.

The epidermis and dermis are exposed in the tail region of the theropod dinosaur Sinosauropteryx. The specimen under study, like many others of the genus and other air-breathing vertebrates discovered in the Jehol biota, shows strong opisthotonus (i.e., recurvature of the spine) that includes the neck and tail. Here, recurvature of the tail upwards is considered to have aided the separation of the dermal and epidermal elements of the skin. Addressing a somewhat controversial question, the sequence of events in which this apparently occurred also suggests that the development of opisthotonus may have occurred post mortem rather than perimortem in this specimen. Crucially, epidermal structures considered to be scales are preserved overlying the posterior part of the tail and alongside it. They are approximately 2.0–2.5 mm in diameter and have distinctive papillae radiating around a central point, comparable to scales in some modern day lizards. Some of these scales overlie thick structural fibres external to the body outline, extending posteriorly at steep angles to the body's long axis, considered by many workers to be protofeathers. Intervening between the epidermal scales and the deeper structural fibres are preserved traces of a dermal fibre meshwork with two layers of oppositely oriented fibres.

Summary An endemic diatom, Cyclotella rhomboideo-elliptica Skuja, from the Yunnan Plateau, has been disappearing gradually from some lakes of the plateau. This study investigated the diatom's distribution in 30 lakes and documents long-term population changes in the paleolimnological record of a deep lake, Lake Fuxian. Living cells of C. rhomboideo-elliptica were found in five Yunnan Plateau lakes in 1957, but cells were restricted to Lake Fuxian in 2005. Its absolute abundance fluctuated from low to high to low. Our study suggests that nutrient concentrations correlate with C. rhomboideo-elliptica's s abundance and survival. We infer that the disappearance of C. rhomboideo-elliptica in some lakes may be due to increased nutrient concentrations and the species may be indicators of low nutrients. During the study, we also found that decreased in the diatoms average long axis length after the early 1990s. This morphological change was likely due to higher nutrient concentrations or to the increase in temperature, or a combination of the two.

Teeth are generally used for actions in which they experience mainly compressive forces acting toward the base. The ordered tooth enamel(oid) and dentin structures contribute to the high compressive strength but also to the minor shear and tensile strengths. Some vertebrates, however, use their teeth for scraping, with teeth experiencing forces directed mostly normal to their long axis. Some scraping suckermouth catfishes (Loricariidae) even appear to have flexible teeth, which have not been found in any other vertebrate taxon. Considering the mineralized nature of tooth tissues, the notion of flexible teeth seems paradoxical. We studied teeth of five species, testing and measuring tooth flexibility, and investigating tooth (micro) structure using transmission electron microscopy, staining, computed tomography scanning, and scanning electron microscopy-energy-dispersive spectrometry. We quantified the extreme bending capacity of single teeth (up to 180 degrees) and show that reorganizations of the tooth (micro) structure and extreme hypomineralization of the dentin are adaptations preventing breaking by allowing flexibility. Tooth shape and internal structure appear to be optimized for bending in one direction, which is expected to occur frequently when feeding (scraping) under natural conditions. Not all loricariid catfishes possess flexible teeth, with the trait potentially having evolved more than once. Flexible teeth surely rank among the most extreme evolutionary novelties in known mineralized biological materials and might yield a better understanding of the processes of dentin formation and (hypo) mineralization in vertebrates, including humans.