Basal Zone Research Articles

Structural features and the evolutionary mechanisms of the basal shear zone of a rockslide

Rockslides commonly form a shear zone to accommodate their displacements. As such, the landslide history and mechanism must be recorded in the structural features of the shear zone. We investigated the basal shear zone of a 60-m-thick rockslide body with a lateral displacement of 200 m on a dip slope and found the evolutionary mechanisms of a basal shear zone of a rockslide. A basal shear zone on a dip slope is initiated along a lithologic boundary that is characterized by a high competency contrast, such as pelitic rock and greenstone or chert, and develops in the weaker rock, which was pelitic rock in the present study. The basal shear zone first develops with fracture of the rock mass, followed by intragranular fracturing of rock fragments. Shear strain by landslide gradually localizes to a narrow zone in the fractured zone to form a clayey layer by cataclasis of rock fragments. The rock fragments in the clayey layer become rounded by attrition, and the clayey layer finally obtains shear surfaces with slickensides.

In situ weathering of rocks or aeolian silt deposition: key parameters for verifying parent material and pedogenesis in the Opawskie Mountains\u2014a case study from SW Poland

PurposeThe aims: (1) to investigate the role of the in situ weathering of bedrock in providing substrate for soil formation; (2) to evaluate the aeolian contribution to the mountainous soils in the vicinity of thick loess cover; and (3) to determine the influence of aeolian silt on further soil development.Materials and methodsThe sampled sites were arranged along the slope toposequence, where an aeolian/silt admixture possibly occurred. Each soil catena started at the top of a hill and ended at its foot. Such an arrangement of the soil profiles ensured the tracking of loess thickness variations and detection of the depth of the residuum-derived materials. One reference soil profile, consisting of aeolian silt deposits, was made. The following soil properties were determined: pH, organic carbon content, soil texture, exchangeable acidity, exchangeable ions and geochemistry. In addition, thin sections were prepared from rock samples to confirm the type of bedrock present.Results and discussionThe soils in the studied area were classified as Cambisols, Luvisols and Stagnosols, characterised by silt loam texture and a high content of elements indicating an aeolian silt contribution—Hf (7.4 to 14.8 ppm) and Zr (274.4 to 549.0 ppm). These values differ strongly from the residues typical of weathered quartzite, greywacke or catalasite substrates, which generally have low concentrations of Hf and Zr (0.7 to 7.0 ppm and 26.0 to 263 ppm, respectively). Based on the morphological, textural and geochemical data of the studied soils, three layers were distinguished, which show different inputs of aeolian silt: (1) an aeolian silt mantle; (2) a mixed zone in which loess was incorporated into the local material; and (3) a basal zone, free of the influence of aeolian silt. Based on the obtained results, a hypothetical pathway for soil formation in mountainous areas, influenced by aeolian silt admixing, was proposed.ConclusionsOur study demonstrates that the soils developed in the Opawskie Mountains are characterised by an aeolian silt influence. This differentiates them from weakly developed soils, which comprise materials formed during in situ weathering only. Materials originating from bedrock weathering did not play an independent role as the parent material for the studied pedons. Aeolian silt was admixed with already existing autochthonous substrates, or completely replaced them. This influence on the soil formation resulted in the occurrence of Luvisols, Stagnosols and Cambisols. Such soils cannot be formed from the weathering of quartzites and greywackes, which contribute to a less structure-forming medium.

Multi-omics analysis of the development and fracture resistance for maize internode

The maize stalk is an important mechanical supporting tissue. The stalk fracture resistance is closely related to lodging resistance, and thus the yield. In this study, we showed that the basal zone (BZ) was more fragile than the middle zone (MZ) of the stalk internode before tasseling. In order to clarify the relationship between the different zones and fragile resistance between the internodes, we systematically analyzed the phenotypic, metabolomic and transcriptomic differences. The results indicated that the BZ zone had lower stalk strength, which corresponded to the results of less lignin, cellulose and hemicellulose than that of the MZ. The 27 highly enriched metabolites and 4430 highly expressed genes in the BZ mainly participated in pentose phosphate, and in ribosome and sterol synthesis pathways, respectively. In addition, the BZ had higher vascular bundles density but smaller size compared with the MZ. By contrast, the 28 highly enriched known metabolites and 4438 highly expressed genes in the MZ were mainly involved in lignin synthesis, and secondary metabolites synthesis, respectively, especially the phenylpropanoid synthesis. The results provide a deeper understanding of the relationship between development and fracture differences in stalk, and may facilitate the improvement of field management practice to reduce lodging.

Sexual dimorphism of the cuticle and body-wall muscle in free-living mycophagous nematodes

Sexual dimorphism in motility-related traits is widespread among animals, including several species of Nematoda. However, no study has examined motility-related structural components and compared them between sexes. We examined the motility-related components in four species: Bursaphelenchus conicaudatus Kanzaki, Tsuda and Futai, 2000; Bursaphelenchus rainulfi Braasch and Burgermeister, 2002; Bursaphelenchus doui Braasch, Gu, Burgermeister and Zhang, 2005; Parasitaphelenchus costati Kanzaki, Ekino, Ide, Masuya and Degawa, 2018. We measured the structure and amount of cuticle and body-wall muscles and estimated their relationship to body diameter or total cross-sectional area. Although no structural differences were observed in muscle, the relevant muscle area of B. doui and P. costati was significantly smaller in females than in males. This difference was greatest in P. costati. In all but B. doui, the relative cuticle thickness was significantly smaller in females than in males. Furthermore, only P. costati females had no striated basal zones in their cuticles; these are thought to be cross-linked proteins that provide strength to nematode cuticle during body movement. These results indicate that sexual dimorphism in motility-related structural components is present in P. costati and that females invest less energy in the components than do males.

Comparative Analysis of SUS Gene Family between Saccharum officinarum and Saccharum spontaneum

Sugarcane is a major sugar-producing crop, which contributed 80% of the world’s sugar in 2010. Saccarhum officinarum is a domestic species with high sugar content, while, Saccarhum spontaneum is a wild species with stress tolerance. The highly complex polyploid genome of modern sugarcane cultivars arose from the interspecific hybridization between S. officinarum and S. spontaneum. Sucrose synthase (SUS) is a key enzyme for sucrose metabolism in plants, where activity is bidirectional: both synthetic and separate. In this study, nine genomic sequences of S. officinarum and eight genomic sequences of S. spontaneum for five SUS genes were identified. Phylogenetic analysis showed that the Saccharum SUS3 and SUS5 genes were generated from ρ duplication, SUS1 and SUS2 were duplicated after the split of dicot and monocot species, and SUS4 was retained from the last common ancestor before the origination of Angiospermae. The gene structure and Ka/Ks analysis suggested the functional constraint of SUS genes in the two Saccharum species. Gene expression based on RNA-seq analysis revealed that SUS1was dominantly expressed in source tissues including the internodes and the basal zone of the leaves, SUS2 was detectable in all tissues examined, and the remaining three SUS genes were expressed at low levels in the examined tissues, indicating SUS1 is the key member involved in sucrose accumulation. In addition, SUS genes were observed to be present at higher expression levels in S. officinarum than in S. spontaneum, while SUS2 presented different expression patterns during the circadian rhythm in S. spontaneum and S. officinarum, suggesting the two SUS genes contribute to the differential sugar levels in these species. Our comprehensive study in Saccharum provides the foundations for further functional studies of the SUS gene family.

Histopathological changes in placenta and liver of pregnant rats administered with aqueous extract of Dioscorea hispida var. daemona (Roxb) Prain & Burkill

Dioscorea hispida var. daemona (Roxb) Prain & Burkill (DH), also known a tropical yam or intoxicating yam is a bitter wild tuber which is consumed as a staple food and traditionally used as a remedy in Malaysia. However, DH is also notorious for its intoxicating effects and there is currently a dearth of study of possible effects of DH on liver and placental tissues and hence its safe consumption warrants in-depth investigation. This study was therefore designed to investigate into the effect of DH on liver and placenta of pregnant rat via histopathological examination. Thirty pregnant Sprague-Dawley rats were randomly divided into five groups consisting of a control (distilled water) and four DH aqueous extract groups (250, 500, 1000 and 2000 mg/kg body weight). The extracts were administered via oral gavage daily throughout the study and animals were sacrificed on day 21. Paraffin-embedded, hematoxylin and eosin stained sections of placenta and liver were examined. Significant changes (p < 0.05) were observed on relative liver and placental weights of animals treated with 2000 mg/kg body weight DH extract. The placental numbers were decreased with the increased of DH extract concentration. Liver histological examination in all treated groups showed that tissues underwent degeneration characterized by hepatocyte swelling, cytoplasmic vacuolation, cytolysis, margination and clumping of nucleus chromatin. Changes of the basal and labyrinth zone were observed in placental tissues in all treated groups. Glycogen cells were reduced with fibrin deposition in the basal zone, while irregular vessel formation was demonstrated in the labyrinth zone. UHPLC-ESI-MS analysis showed the presence four steroidal saponins DH. In conclusion, DH aqueous extract exert hepatotoxicity and adverse effects on the placenta of rats. However, the underlying mechanism and phytochemicals inducing the observed toxicity require further investigation.

Stromatolite-dominated microbialites at the Permian–Triassic boundary of the Xikou section on South Qinling Block, China

Permian–Triassic boundary microbialites (PTBMs) are organosedimentary carbonates formed immediately after the end-Permian mass extinction. All those reported PTBMs constrained by convincing conodont biozones are present stratigraphycally not higher than the Hindeodus parvus zone and most of them are dominated by thrombolites. This paper provides the first record of a brief, but spectacular development of stromatolite-dominated PTBMs within the basal Isarcicella isarcica conodont zone of the earliest Triassic from the Xikou section of South Qinling Block that was at the margin of the North China Block during the Permian–Triassic transition and was geographically separated from the major occurrence of post-extinction microbialites in the South China Block. This stromatolite cap overlies a 3.7-m-thick oolitic limestone and is composed of a lower 0.2-m-thick bed and an upper 0.5-m-thick bed, separated by a 0.2-m-thick greyish green siliciclastic mudstone. These two stromatolite beds mainly consist of columnar stromatolites with subordinate domal stromatolites. The intercolumn and interstitial spaces within the stromatolites are filled with oolitic grainstones. At the microscopic scale, laminoid structures in stromatolites comprise wavy, millimetric-domical and tangled laminae. The increased grain and fossil contents and/or bioturbation in the domical and tangled laminae indicate that the formation of these laminae is likely related to an increase in the populations and the disruptions by benthic metazoans, as well as an influx of sediment grains. The δ13Ccarb values fluctuate between 2‰ and 3‰ in the uppermost Permian strata; a distinct negative shift of 1.9‰ occurs at the topmost oolitic grainstone, just below the lower stromatolite bed, and the lowest value of −0.1‰ is located at the base of the upper stromatolite bed. The stratigraphic succession from stromatolites to thrombolites of the PTBMs may represent a transgressive succession and/or a transient ecosystem recovery immediately after the end-Permian mass extinction. The thrombolites-dominated PTBMs mainly developed in near-equator shallow marine geographic locations, and stromatolite-dominated PTBMs mainly developed at higher latitude settings, which probably indicates that a relatively lower diversity and abundance of marine benthic metazoans existed at higher latitudes after the end-Permian mass extinction.

Effect of aspartame on the placenta of adult albino rat. A histological and immunohistochemical study

Aspartame is an artificial sweetener usually consumed by hundreds of millions of persons all over the world. Its metabolites can be toxic to many organs and there are only a few studies on the use of aspartame during gestation. The present study was designed to fully evaluate the effect of aspartame on the histological structure of the placenta in the adult albino rat. Twenty pregnant female rats were equally divided into group I that served as control, and group II that received aspartame at a dose 14 mg/kg by gavage on the 9th, 10th and 11th day of pregnancy. Placental specimens were processed for histological and immunohistochemical staining against vascular endothelial growth factor (VEGF). Aspartame induced a significant decrease in the mean placental weight and the mean thickness of both labyrinth and basal zones. Damage in the placenta was detected in the form of rupture of the interhemal membrane, lysis of glycogen trophoblast cells, spongiotrophoblast cells with vacuolated cytoplasm and darkly stained nuclei. A significant increase in vascular endothelial growth factor expression in both labyrinth and basal zones was detected. Ultrastructural examination showed fetal capillaries with condensed nuclei of endothelial cells, cytotrophoblasts with condensed fragmented nuclei and vacuolated cytoplasm, and syncytiotrophoblasts with irregular condensed fragmented nuclei. It could be concluded that aspartame has deeply impacted the normal structure and presumably the function of the placenta, therefore, restrictions are to be imposed on the consumption of aspartame especially during pregnancy.

The effect of transcervical endometrial resection on clinical symptoms related to intrinsic adenomyosis and junctional zone changes

ObjectivesTo assess the effect of transcervical endometrial resection on clinical symptoms related to histopathological findings of the junctional zone.Study designThis prospective study took place at a university hospital. Premenopausal women suffering from abnormal uterine bleeding and/or pelvic pain and scheduled for transcervical endometrial resection were enrolled (n = 112). Histopathological findings of the endomyometrial biopsies were categorized as follows: Adenomyosis of the inner myometrium (intrinsic adenomyosis): ≥ 2 mm myometrial invasion without contact to the basal endometrium, serrated junctional zone: > 3 mm myometrial invasion with contact to the basal endometrium and linear junctional zone: No or marginal myometrial invasion (≤ 3 mm) with contact to the basal endometrium. All study participants received a baseline and two follow-up questionnaires (6 and 18 months after surgery) regarding symptom severity, health-related quality of life and pelvic pain. Data regarding reintervention surgery was obtained from the National Database Patoweb. The rate of reintervention surgery and the improvement in symptom severity, health-related quality of life and pelvic pain were correlated to histopathological findings.ResultsTwenty-four patients had intrinsic adenomyosis, 31 had serrated junctional zone and 57 had linear junctional zone. Fifteen patients (13%) underwent reintervention surgery; three (20%) within 6 months, nine (60%) between 6–18 months and three (20%) > 18 months after transcervical endometrial resection. Reintervention surgery was more common in women with intrinsic adenomyosis compared to women without (33% (95% CI: 16–55) vs 8% (95% CI: 3–16)) (p-value: < .05). Nine patients (38%) with intrinsic adenomyosis were asymptomatic based on low symptom severity score, high health-related quality of life and no pelvic pain at 18 months follow-up. Patients with linear junctional zone had a higher improvement in symptom severity and health-related quality of life than patients with intrinsic adenomyosis or serrated junctional zone at 6 months follow-up after surgery (p-value < .05). However, there was no significant difference in pelvic pain reduction.ConclusionThe effect of transcervical endometrial resection may depend upon the degree of junctional zone changes, and patients with intrinsic adenomyosis are more likely to undergo reintervention surgery than patients with either linear or serrated junctional zone. However, intrinsic adenomyosis may also be successfully treated with endometrial resection.

PROBLEM OF TREATMENT OF THE CAPILLARY ANGIODYSPLASIA OF SKIN IN CHILDREN

Capillary angiodysplasia of the skin presents by itself pathologically dilated capillaries located under the basal zone of the growth of the epidermis. There are many options for the correction of this vascular pathology of the skin, including general and local methods. In recent years, laser treatments for capillary angiodysplasia have become widespread. According to many authors, the most effective and promising method is laser photodestruction by radiation of the yellow-green spectral range. Unfortunately, the optimal ranges of the parameters of exposure to laser radiation in the treatment of specific forms of capillary angiodysplasia of the skin, taking into account nature and age characteristics of the skin in children, have not yet been determined.

Arterial faults and their role in mineralizing systems

In quartzo-feldspathic continental crust with moderate-to-high heat flow, seismic activity extends to depths of 10–20 km, bounded by isotherms in the 350–450 °C range. Fluid overpressuring above hydrostatic in seismogenic crust, is heterogeneous but tends to develop in the lower seismogenic zone (basal seismogenic zone reservoir = b.s.z. reservoir) where the transition between hydrostatically pressured and overpressured crust is likely an irregular, time-dependent, 3-D interface with overpressuring concentrated around active faults and their ductile shear zone roots.The term Arterial Fault is applied to fault structures that root in portions of the crust where pore fluids are overpressured (i.e. at > hydrostatic pressure) and serve as feeders for such fluids and their contained solutes into overlying parts of the crust. While arterial flow may occur on any type of fault, it is most likely to be associated with reverse faults in areas of horizontal compression where fluid overpressuring is most easily sustained. Frictional stability and flow permeability of faults are both affected by the state of stress on the fault (shear stress, τ; normal stress, σn), the level of pore-fluid pressure, Pf, and episodes of fault slip, allowing for a complex interplay between fault movement and fluid flow. For seismically active faults the time dependence of permeability is critical, leading to fault-valve behaviour whereby overpressures accumulate at depth during interseismic intervals with fluid discharged along enhanced fault-fracture permeability following each rupture event. Patterns of mineralization also suggest that flow along faults is non-uniform, concentrating along tortuous pathways within the fault surface.Equivalent hydrostatic head above ground level for near-lithostatic overpressures at depth (<1.65× depth of zone) provides a measure of arterial potential. Settings for arterial faults include fault systems developed in compacting sedimentary basins, faults penetrating zones of active plutonic intrusion that encounter overpressured fluids exsolved from magma, together with those derived from contact metamorphism of fluid-rich wallrocks, and/or from regional devolatilisation accompanying prograde metamorphism. Specially significant are active faults within accretionary prisms rooted into overpressured subduction interfaces, and steep reverse faults activated by high overpressures from b.s.z. reservoirs during compressional inversion.

A study on morpho-histogenesis of human foetal pons

Introduction: During the second month of intra uterine life, the metencephalon widens and the cells of the metencephalon present in the ependymal zone migrate into mantle and marginal zones and assume the adult position by 12th week of intrauterine life. The cellular collection constituting the various nuclei of tegmentum of pons is very much striking amidst reticular formation. Materials and Methods: Out of 100 foetuses obtained, foetuses with a difference of two weeks gestation from first trimester to third trimester have been taken for the study (10wks,12wks, 14wks,16wks, 18wks, 20wks, 22wks, 24wks, 28wks, 32wks, 36wks and 40wks). Results: The length of the pons increased from 3mm to 2cms and width increased from 5mm to 1.8 cm. The neurons in the earlier gestations are small and round. By the end of third trimester, they became large spindle (fusiform) shaped and multipolar. Conclusion: Knowledge of the migration of neurons to form nuclear groups is essential for defects of the basal ventricular zone result in defects of specific cranial nerve nuclei such as the abducent and facial nerves and for any prenatal evaluation in cases of suspected of brain anomalies Keywords: Abducent nucleus, Facial nucleus, Multipolar neurons, Spindle shaped neurons.

The hematopoietic organ of Macrobrachium rosenbergii: Structure, organization and immune status

The hematopoietic organ (HO) of the giant freshwater prawn Macrobrachium rosenbergii is a discrete, whitish mass located in the epigastric region of the cephalothorax, posterior to the brain. It is composed of hematopoietic cells arranged in a thick layer of numerous lobules that surround a central hemal sinus from which they are separated by a thin sheath. At the center of the sinus is the muscular cor frontale. The lobules extend radially outward from the sinus in three developmental zones. Basal Zone 1 nearest the sinus contains large hematopoietic stem cells with euchromatic nuclei that stain positive for proliferation cell nuclear antigen (PCNA). Zone 2 contains smaller, actively dividing cells as indicated by positive 5-bromo-20-deoxyuridine (BrdU) staining. Distal Zone 3 contains small, loosely packed cells with heterochromatic nuclei, many cytoplasmic granules and vesicles indicating that they will eventually differentiate into hemocytes and enter circulation. Three main arteries, namely the ophthalmic and the 2 branches of the antennary, connect the heart to the HO. Use of India ink and 0.1 μm fluorescent micro-beads injected into the heart revealed that the cor frontale could immediately remove foreign particles from hemolymph by filtration. Fluorescent beads were also detected in the hematopoietic tissue at 30 min after injection, indicating that it could be penetrated by foreign particles. However, the fluorescent signal completely disappeared from the whole HO after 4 h, indicating its role in removal of foreign particles. In conclusion, the present study demonstrated for the first time the detailed histological structures of the HO of M. rosenbergii and its relationship to hematopoiesis and removal of foreign particles from hemolymph.

Strain analysis of a seismically imaged mass‐transport complex, offshore Uruguay

AbstractStrain style, magnitude and distribution within mass‐transport complexes (MTCs) are important for understanding the process evolution of submarine mass flows and for estimating their runout distances. Structural restoration and quantification of strain in gravitationally driven passive margins have been shown to approximately balance between updip extensional and downdip contractional domains; such an exercise has not yet been attempted for MTCs. We here interpret and structurally restore a shallowly buried (c. 1,500 mbsf) and well‐imaged MTC, offshore Uruguay using a high‐resolution (12.5 m vertical and 15 × 12.5 m horizontal resolution) three‐dimensional seismic‐reflection survey. This allows us to characterise and quantify vertical and lateral strain distribution within the deposit. Detailed seismic mapping and attribute analysis shows that the MTC is characterised by a complicated array of kinematic indicators, which vary spatially in style and concentration. Seismic‐attribute extractions reveal several previously undocumented fabrics preserved in the MTC, including internal shearing in the form of sub‐orthogonal shear zones, and fold‐thrust systems within the basal shear zone beneath rafted‐blocks. These features suggest multiple transport directions and phases of flow during emplacement. The MTC is characterised by a broadly tripartite strain distribution, with extensional (e.g. normal faults), translational and contractional (e.g. folds and thrusts) domains, along with a radial frontally emergent zone. We also show how strain is preferentially concentrated around intra‐MTC rafted‐blocks due to their kinematic interactions with the underlying basal shear zone. Overall, and even when volume loss within the frontally emergent zone is included, a strain difference between extension (1.6–1.9 km) and contraction (6.7–7.3 km) is calculated. We attribute this to a combination of distributed, sub‐seismic, ‘cryptic’ strain, likely related to de‐watering, grain‐scale deformation and related changes in bulk sediment volume. This work has implications for assessing MTCs strain distribution and provides a practical approach for evaluating structural interpretations within such deposits.

On some Mississippian (Carboniferous) brachiopods from neptunian dykes of the Harz Mountains (central Germany)

Different generations of Mississippian neptunian dykes developed in the drowned Iberg–Winterberg Devonian seamount (Harz Mountains, Germany) yielded poorly diverse and generally small-sized brachiopod faunas dominated by spire-bearers (athyridides, spiriferides) and including several homeomorphic spiriferides. Four limestone levels are distinguished: Erdbach-II Limestone (Scaliognathus anchoralis Zone and basal Pseudognathodus homopunctatus Zone, late Ivorian and basal early Visean), Actinotheca Limestone (Pseudognathodus homopunctatus Zone, Arundian–Holkerian–early Asbian), Goniatite Limestone (Gnathodus bilineatus and Lochriea nodosa zones, late Asbian–early Brigantian), Ibergirhynchia Limestone (Lochriea nodosa Zone, early Brigantian). The faunas (dominant cephalopod facies) of the traditional ‘Erdbach Limestone’ in all older literature related to the Iberg–Winterberg Massif are a mixture of the two older horizons (light crinoidal limestones; late Ivorian to early Asbian), of which the age of their fossil content (especially the well-studied trilobites) needs to be revised by conodonts. New spiriferide genera are described, namely Roemerithyris gen. nov. and Felsithyris gen. nov. with Spirifer macrogaster Roemer 1852 and Felsithyris hercynica gen. et sp. nov. as type species, respectively. The latter species is the most common element of an almost monospecific assemblage of early–middle Visean age. Regeneration traces after fish attacks, developed on a spiriferide shell, are illustrated.

Physical mechanical characterization of a rockslide shear zone by standard and unconventional tests

Field and monitoring evidences show that deformation in a rockslide is predominantly localized along a basal shear zone. Mineralogic, grain size, thickness, and fabric characteristics of the shear zone control its behavior and the possible evolution of the rockslide from a slow creeping to a fast moving one. Standard experimental tests can characterize the material from the strength and the deformability, but they are not able to reproduce the in-situ conditions. In this paper, we discuss the results from campaign of experimental tests to characterize the shear zone behavior sampled from a rock-slide. In particular, the shear zone behavior and its evolution are investigated via conventional (direct shear, standard triaxial) and unconventional laboratory testing (with a LHV low-to-high-velocity ring shear apparatus). By LHV tests, it is possible to impose and monitor shearing displacement and velocity and the pore water pressure, simulating in-situ conditions. The tests were carried out on samples collected from boreholes through cataclastic shear zones from the Mont de La Saxe rockslide (Western Italian Alps) containing both phyllosilicates (XRF quantify in about 20%) and graphite (about 10%). Investigations reveal a grain-size reduction in some tests (up to 1%) and a preferential particle alignment in the shear zone. Mechanical investigations evidence a marked creep behavior characterized by two stages after the application of the loading steps. Nevertheless, the stress increments are imposed with a prefixed value, and the viscous displacement rate increases due to the damaging process. Finally, the mean values of the viscous parameters are computed considering Newtonian viscosity law range from 6.40 × 106 to 6.39 × 107 kPa s for the transition phase and from 2.01 × 108 to 5.89 × 109 kPa s for the steady state and according to the tangential stress increment.

The effects of β-naphthoflavone on rat placental development.

The morphological effects of β-naphthoflavone (β-NF) on placental development in pregnant rats were examined. β-NF, administered to pregnant rats intraperitoneally at 15 mg/kg bw from gestation day (GD) 9 to GD 14, had no effect on maternal body weight gain, mortality, or clinical sign. In the β-NF-exposed rats, intrauterine growth retardation (IUGR) rates increased on GDs 17 and 21, although there was no effect on fetal mortality rate, fetal or placental weight, or external fetal abnormality. Histopathologically, β-NF induced apoptosis and inhibition of cell proliferation of the trophoblastic septa in the labyrinth zone, resulting in its poor development. In the basal zone, β-NF induced spongiotrophoblast apoptosis and delayed glycogen islet regression, resulting in their cystic degeneration. β-NF-induced CYP1A1 expression was detected in the endothelial cells of the fetal capillaries in the labyrinth zone and in the endothelial cells of the spiral arteries in the metrial gland, but not in any trophoblasts. This indicates that CYP1A1 is inducible in the endothelial cells of the fetal capillaries in the labyrinth zone, and that these cells have an important role in metabolizing CYP1A1 inducers crossing the placental barrier.

Magnetic fabric development in the Lower Seve thrust from the COSC-1 drilling, Swedish Caledonides

The COSC-1 project drilled the several hundred meters thick basal shear zone of the Lower Seve nappe with mylonites in mica schists, amphibole schists and gneisses. In zones of high magnetic susceptibility from 1910 to 2450 m we studied magnetic and petrographic fabrics, and magnetic mineralogy. Borehole imaging allowed for geographic reorientation of the samples and offered the opportunity to study anisotropy of magnetic susceptibility (AMS) in relation to tectonic evolution of the Seve thrust. We measured AMS at room temperature, added low-temperature and field-dependent AMS for a subset of samples, and compared magnetic with petrographic fabrics. Triaxial and prolate magnetic fabrics with degree of anisotropy (P′) up to 3.2 together with abundant S-C fabrics and strain partitioning around porphyroclasts indicate dominant simple shear until 2300 m. Magnetite and ilmenohematite mimic the rock fabric due to fabric parallel alignment and/or magnetic interaction and either contribute to increase or decrease of P′, depending on the dominating rock fabric elements. Field-dependency of pyrrhotite and magnetite in kmax-direction further increases P′. Homogeneous and oblate petrographic and magnetic fabrics in the greenschist-grade overprinted rocks below 2300 m with subhorizontal kmax-kint-girdle distributions indicate dominant flattening. AMS depicts shear fabrics including magnetite and ilmenohematite, and is additionally increased by retrograde magnetite-rutile intergrowth in ilmenohematites. We interpret that shape and degree of AMS are controlled by (a) tectonic deformation and strain, (b) alteration and magnetic grain interaction, and (c) field-dependency of deformed pyrrhotite and/or magnetite. We observed that all petrographic and magnetic subfabrics are coaxial, and lineations are mainly E-W to SE-NW directed confirming the transport direction of the Caledonian allochthonous. From our microstructural and AMS results we suggest that thrusting of the Lower Seve unit commenced under simple shear conditions at higher metamorphic grades and subsequently switched to more pure shear under greenschist-grade conditions.

The Genus Delphinites Sayn (Ammonoidea: Neocomitidae) in the Lower Valanginian of the Russian Platform

This paper presents the results of the revision of the taxonomic composition and stratigraphic distribution of Central Russian representatives of the Valanginian genus Delphinites. The lower Undaloplicatilis zone of the Valanginian in the basin of the Sura River (Menya River) contains D. undulatoplicatilis (Stchirowsky) [subjective synonyms: Oxynoticeras tuberculiferum Stchirowsky, Pseudogarnieria securis Sasonova], D. menensis (Stchirowsky), D. alatyrense (Kemper), D. kurmyschensis (Stchirowsky), D. stchirowskyi (Sasonova), D. donovani Alsen et Rawson and D. heineae sp. nov. In addition, Delphinites sp. was figured from the Michalskii Zone (terminal Lower Valanginian) of the Kostroma Region (Unzha River). Thus, the interval of distribution of the genus Delphinites is not restricted by the basal zone of the Valanginian.

Two- and three-dimensional ultrasonographic features related to histopathology of the uterine endometrial-myometrial junctional zone.

Our aim was to correlate junctional zone thickening and irregularity (junctional zone disease) and other ultrasonographic features of adenomyosis with the histopathology of the endometrial-myometrial junctional zone. Consecutively enrolled premenopausal women (n=110) scheduled for hysterectomy or transcervical endometrial resection due to abnormal uterine bleeding and/or menstrual pain, underwent two- and three-dimensional transvaginal ultrasonography on the day of surgery with the observer blinded to previous diagnosis. Junctional zone maximum thickness (JZmax ), junctional zone maximum irregularity (JZdif ) and ultrasonographic characteristics of adenomyosis were compared with histopathology of the junctional zone defined as (1) adenomyosis of the inner myometrium, ≥2mm myometrial invasion without contact to the basal endometrium, (2) serrated junctional zone, >3mm myometrial invasion with contact to the basal endometrium or (3) linear junctional zone, no or marginal myometrial invasion ≤3mm with contact to the basal endometrium. Adenomyosis of the inner myometrium, serrated junctional zone and linear junctional zone was present in 29%, 35% and 35% of the women, respectively. Median JZmax and median JZdif expanded from linear junctional zone (8.5 and 3.3mm) to serrated junctional zone (10.1 and 4.1mm) to adenomyosis of the inner myometrium (14.6 and 9.2mm) (P<0.05). In addition, the median number of characteristic adenomyosis-like ultrasonographic features increased from the linear junctional zone to the serrated junctional zone to adenomyosis of the inner myometrium (P<0.05). A slightly thickened and/or irregular junctional zone corresponds to a histopathologically defined serrated junctional zone. This study emphasizes three distinct appearances of the junctional zone: adenomyosis of the inner myometrium, junctional zone disease (serrated junctional zone) and linear junctional zone. This classification may be useful in future clinical studies.