External Zone Research Articles

Security Protection Scheme of Brain-Like System Based on Cloud Computing Platform

The functions of human being’s brains are very difficult to simulation by computers, therefore many scientists are focusing on research of brain-like system (or robotic brain) based on cloud computing platform, which can simulate the human being’s hearing, vision, thinking and action. However, due to the security incidents of the internet occur frequently, the robotic brain based on the cloud computing platform may be seriously harmed by the security incidents. Therefore, this paper designs and implements of the overall security solution of the robotic brain based on cloud platform. The cloud platform intranet is divided into the intranet trusted zone and the DMZ zone, and strict filtering strategies are set in the zone, and firewalls and firewalls are set up in the DMZ zone and the external network zone. Monitor incoming network traffic at the network interface, and deal with abnormal traffic. At the same time, it audits security events in the intranet, conducts the statistical analysis on content security, server security, and application control, and blocks suspicious attacking IP. A series of safety measures are adopted to ensure the safety of the internal network of the robotic brain based on cloud platform.

Vasopressin gene products are colocalised with corticotrophin-releasing factor within neurosecretory vesicles in the external zone of the median eminence of the Japanese macaque monkey (Macaca fuscata).

Arginine vasopressin (AVP), when released into portal capillaries with corticotrophin-releasing factor (CRF) from terminals of parvocellular neurones of the hypothalamic paraventricular nucleus (PVH), facilitates the secretion of adrenocorticotrophic hormone (ACTH) in stressed rodents. The AVP gene encodes a propeptide precursor containing AVP, AVP-associated neurophysin II (NPII), and a glycopeptide copeptin, although it is currently unclear whether copeptin is always cleaved from the neurophysin and whether the NPII and/or copeptin have any functional role in the pituitary. Furthermore, for primates, it is unknown whether CRF, AVP, NPII and copeptin are all colocalised in neurosecretory vesicles in the terminal region of the paraventricular CRF neurone axons. Therefore, we investigated, by fluorescence and immunogold immunocytochemistry, the cellular and subcellular relationships of these peptides in the CRF- and AVP-producing cells in unstressed Japanese macaque monkeys (Macaca fuscata). Reverse transcription-polymerase chain reaction analysis showed the expression of both CRF and AVP mRNAs in the monkey PVH. As expected, in the magnocellular neurones of the PVH and supraoptic nucleus, essentially no CRF immunoreactivity could be detected in NPII-immunoreactive (AVP-producing) neurones. Immunofluorescence showed that, in the parvocellular part of the PVH, NPII was detectable in a subpopulation (approximately 39%) of the numerous CRF-immunoreactive neuronal perikarya, whereas, in the outer median eminence, NPII was more prominent (approximately 52%) in the CRF varicosities. Triple immunoelectron microscopy in the median eminence demonstrated the presence of both NPII and copeptin immunoreactivity in dense-cored vesicles of CRF-containing axons. The results are consistent with an idea that the AVP propeptide is processed and NPII and copeptin are colocalised in hypothalamic-pituitary CRF axons in the median eminence of a primate. The CRF, AVP and copeptin are all co-packaged in neurosecretory vesicles in monkeys and are thus likely to be co-released into the portal capillary blood to amplify ACTH release from the primate anterior pituitary.

Mesozooplankton succession in a sub-Antarctic bay (Beagle channel, Southern tip of South America): distinctive annual patterns between two environmentally different zones

Frequent sampling of zooplankton is essential to understand their annual dynamics. However, in polar and subpolar ecosystems, such sampling is rare. This study comparatively analysed, for the first time, the annual mesozooplankton succession in the northwest nearshore and external zones of Ushuaia Bay in the sub-Antarctic Beagle Channel by monthly sampling over two years. The nearshore zone, with shallow waters and strong continental and anthropogenic influence, was characterised by the year-round occurrence of the euryhaline copepod Eurytemora americana and adventitious taxa. The mesozooplankton community exhibited pronounced monthly and year-to-year variability but, as a general seasonal trend, winter assemblages were dominated by the copepod Oithona similis and adventitious nematodes, whereas the spring–summer ones were dominated by E. americana, the cladoceran Podon leuckarti and Cirripedia nauplii. In the external zone, the copepods Drepanopus forcipatus and Ctenocalanus citer were found throughout the year. The annual succession showed a clearer seasonal pattern. Main shifts in community structure occurred in late winter–spring and late summer–autumn, when a high representation of meroplankton and appendicularians was closely associated with phytoplankton blooms. The higher temporal variability in the nearshore community was partially related to variable contributions of adventitious taxa to assemblage composition and may be also reflecting stressful conditions for plankton species linked to freshwater and urban discharges reported within the bay. This study allowed filling the temporal gaps in previous research and providing a more complete picture of the annual mesozooplankton dynamics in the Beagle Channel, generating hypotheses at the community and population levels for future research.

Long Term Outcomes of Endovascular Aortic Repair in Patients With Abdominal Aortic Aneurysm and Ectatic Common Iliac Arteries

The purpose of this study was to evaluate the long term results of endovascular aneurysm repair (EVAR) in patients with abdominal aortic aneurysm (AAA) and ectatic common iliac arteries (CIAs). In a retrospective analysis of a prospectively collected database in two high volume centres, patients with AAAs undergoing elective standard EVAR were divided into two groups: those with both CIA diameters <18mm, and those with at least one ectatic iliac artery (CIA≥18mm). Patients with an intentional external iliac artery landing zone were excluded. Primary outcomes were survival and freedom from re-intervention. Secondary end points were EVAR failure and iliac related endoleak and iliac re-intervention. From 2000 to 2015, 648 patients were included in the study, 277 (43%) had at least one CIA≥18mm. Pre-operative risk factors were similar between the two groups, with the exception of chronic renal insufficiency (p=.010) and cerebrovascular events (p=.040), which were higher in the ectatic CIA group. At 30 days from primary procedure, there was a higher rate of type Ib endoleak in patients with ectatic iliacs (p=.020). A statistically significant increase in the incidence of late type Ib endoleak in patients with ectatic iliac arteries was confirmed at a mean follow up of 74.8 months (p=.01). The need for iliac related re-intervention was higher in patients with CIAs ≥18mm (odds ratio 1.94; 95% confidence interval 1.1-3.2). Ectatic iliac arteries are considered suitable landing zones for EVAR, although there is an increased risk of secondary interventions in time mainly due to late CIA dilation and secondary type Ib endoleak. Patients receiving EVAR with flared iliac limbs may benefit a more intensive surveillance to avoid late failures.

Variación espacio-temporal de larvas de peces en el golfo de Guayaquil, Ecuador

Este estudio presenta la densidad, composición taxonómica, distribución espacial y temporal de larvas de peces en el golfo de Guayaquil, así como la relación con algunas variables físico-químicas. Se recolectaron muestras en 16 estaciones, tomadas en la primera milla náutica del estuario externo e interior del golfo, ubicadas frente a la provincia de Guayas y noroeste de la isla Puná, durante junio a diciembre de 2012. Se realizaron arrastres superficiales con una red cónica simple (ojo de malla: 300 μm; diámetro de boca: 0,3 m; largo: 1,2 m). La temperatura, salinidad y transparencia fueron medidas antes de cada arrastre. Se detectaron diferencias significativas entre zonas, registrando mayor temperatura, menor salinidad y transparencia en el estuario interior. Se colectaron 321 638 ind/100m3 de larvas de peces, pertenecientes a 13 familias y 36 especies entre la zona externa e interna. Engraulidae (58,9 %) fue la familia más abundante en las estaciones del estuario exterior, seguida de Sciaenidae (22,8 %) y Haemulidae (9,6 %). Las familias más frecuentes en el estuario interior fueron Engraulidae (74,4 %) y Gobiidae (16,1 %). El 85 % de la densidad total fue aportada por cinco especies, de las cuales Anchoa sp. y Bairdiella sp. fueron las más abundantes y dominantes, principalmente durante diciembre. La estructura y composición de la comunidad larvaria fue significativamente diferentes entre áreas (MW-U= 450; p &lt; 0,05) y meses de muestreo (KW=14,24; p &lt; 0,05), con mayores registros en el estuario exterior durante diciembre. Con el análisis de redundancia (ADR) se observa que, en el área externa, las especies estuvieron asociadas con la transparencia del agua, mientras que las especies que concurrieron en la zona interna se relacionaron positivamente con la salinidad. En términos generales, la abundancia y riqueza de larvas de peces en el área externa del golfo de Guayaquil está relacionada con las condiciones de transparencia y salinidad local, las cuales favorecieron a la presencia larval.

Tectono‐Stratigraphic and Thermal Evolution of the Western Betic Flysch: Implications for the Geodynamics of South Iberian Margin and Alboran Domain

AbstractThe Betic‐Rif orogen is a key region to understand the evolution of the plate boundary between Africa and Iberia/Europe. This study focuses on the Flysch Complex, which is considered the sedimentary cover of a domain originally positioned between the Iberian and Alboran margins. Based on stratigraphic and depositional evolution constraints, evidence for salt tectonics, combined with new apatite fission‐tracks (AFT) and (U‐Th‐Sm)/He ages from the Flysch Complex and the Subbetic Zone, we propose a geodynamic interpretation for the formation of the Betic Cordillera, accounting for moderate N‐directed transport of the Flysch Complex and synchronous exhumation between External and Internal Zones of the Betic. Early contraction between Africa and Iberia/Europe is reflected in the Cretaceous Flysch basin by a prolonged period of residence in the partial annealing zone for AFT and onset of foreland subsidence at 50 Ma. This stage lasted until the Early to Middle Miocene (20–15 Ma), marked by the rapid succession, in less than 5 Ma, of the deposition of Cenozoic flysch and their rapid exhumation. This event is interpreted to reflect the W‐directed retreating mantle delamination between Africa and Iberia margins at the origin of the collapse of the proto‐Betic orogenic domain and formation of the Alboran domain.

The western São Francisco pericraton interpreted from crustal magnetic and gravity sources

The Neoproterozoic Brasiliano Orogeny shaped the former São Francisco paleocontinent into a preserved cratonic nucleus surrounded by a pericratonic region. In central Brazil, this pericraton crops out as the Goiás Massif, the basement of the northern Brasília Belt. The well-known difficulty of tracing suture zones on surface led to a longstanding dispute on whether the Rio Maranhão Thrust, a structure separating the Internal Zone and the External Zone of the Brasília Belt, marked the Brasiliano suture. This interpretation was largely based on regional gravimetric data showing a steep discontinuity at depth, between these zones. However, the Rio Maranhão Thrust separates two pericratonic domains of the Goiás Massif (Campinorte Domain and Cavalcante-Arraias Domain), which otherwise share similar Paleoproterozoic ages and geology. To properly address the main structural boundaries within the northern Brasília Belt, this work was focused on comparing shallow and deep gravity and magnetic data processed as enhanced anomalies and through matched filter analysis. Our results show that the large mafic-ultramafic complexes within the Internal Zone of the Brasília Belt are masking a smooth gravimetric transition into the External Zone. Additionally, the alleged suture zone is coincident with the Mesoproterozoic rift-related Juscelândia and Palmeirópolis volcano-sedimentary sequences, which have been largely ignored in their role as creating magnetic and gravity suture-like signatures. Along with previous structural and geochronological data, our results argue against the Rio Maranhão Thrust as a suture zone and, instead, support the alternative interpretation of the thrust as an intracontinental feature within a portion of the São Francisco pericraton. This pericratonic region, unliked the preserved cratonic core, was widely affected by Mesoproterozoic rifting and Neoproterozoic thick-skinned thrusting. The Rio Paranã Thrust, on the other hand, is unnoticeable below 8 km depth in gravity and magnetic data, suggesting thin-skinned tectonics also associated with the Brasiliano Orogeny. Finally, the relative crustal homogeneity from the São Francisco craton into the Goiás Massif evidenced by our gravity data and confirmed by first- and second-order magnetic lineaments confirms the nature of a pericraton with dominantly NE (N20-40E) trending lineaments. These lineaments were progressively overprinted by Brasiliano NNE (N45-70E) structures from the western margin of the External Zone into the Internal Zone.

Titanium/Zirconium functionally graded materials with porosity gradients for potential biomedical applications

ABSTRACTThe main aim of this study was the fabrication of functionally graded materials for biomedical applications. Samples with gradient porosities were prepared by a two-stage powder metallurgy method. The internal and external zones of both samples were composed of different phases and pore structures. The phase compositions, microstructures, porosities, and microhardness of the sintered samples were analysed. The results revealed successful fabrication of materials with gradient porosities by the powder metallurgy method, and the transition zone (formed by diffusion) between the external and internal zones was found to be permanent. The Rietveld refinement analysis showed that the production method and atomic radii of the elements used in the synthesis influenced the material structure.This paper is part of a Thematic Issue on The Crystallographic Aspects of Metallic Alloys.

Cyto-, fi broarchitectonics and vascularization of the external (red) zone of the coypu’s meniscus

Meniscus injuries are recognized as the cause of significant morbidity of the musculoskeletal system. Features of the structural organization of the various meniscus zones are a necessaryfor understanding pathologies associated with the knee joint. This will expand and deepen micromorphological knowledge and practically apply during the choice of treatment tactics for meniscus preservation, suturing during reconstructive meniscus repair, reduce the risk of vascular injuries, and make it possible to use tissue engineering for meniscus regeneration. Indeed, today it is known that only the preservation of menisci or a slight ectomy of the inner zone, which cannot be restored with signifi cant injury, can preserve the health and biomechanics of the knee joint. The aim of our work was to determine the characteristics of the cyto- and fi bromorphological characteristics, as well as the degree of vascularization of the external (red) zone of the lateral and medial menisci of the knee joint in foot-moving coypus. A complex of histological and neurohistological research methods was used in the work. The patented neurohistological method of impregnation is performed in its own algorithm. The selection of animals was carried out according to the type of specialization of the limb to the substrate. As a result of histological examination, it was found that cyto-fi broarchitectonics of the external (red) zone of the latera l and medial menisci of the coypus has general biological signs, and species-specifi city is characteristic of vascularization. The external (red) zone of the coypu’s meniscus is similar in st ructure to the dense, formed connective tissue. Cytoarchitectonics is represented by of the fi broblastic typecells: fi brocytes, fi broblasts and undiff erentiated stem cells, which are localized between collagen fi bers individually, in pairs, in a chain or in short rows. Fibroarchitectonics – tightly packed bundles of collagen fi bers with a pronounced parallel orientation. The medial meniscus has saturated zones of intraorgan vascular nutrition due to dilated, anastomosing capillary branches formed by perforations with perimeniscal broad-loop microcirculation nets that occupy large areas and form vascular fi elds, as well as numerous vascular glomeruli. In the lateral meniscus, the vascularization zone is characterized by limited capillary branches, interval and small penetration by capillaries of the meniscus red zone, and limited, localized perimeniscal nets. Key words: fi brocytes, fi broblasts, collagen fi bers, vascularization, vascular glomeruli, external zone, red zone, meniscus, knee joint, coypu.

Polarization-maintaining optical fiber with an anisotropic core compatible with the SMF-28 standard

We present the theoretical study of an all-solid highly birefringent fiber with an anisotropic core fully compatible with SMF-28 fiber and without use of external stress zones or air holes. We propose a fiber with a core composed of interleaved subwavelength layers of silica and germanium-oxide-doped silica. The optimized nanostructured fiber has a phase birefringence of 1.42 × 10 − 4 , and an effective mode area and numerical aperture similar to SMF-28 fiber. We predict coupling losses of 0.1 dB for bidirectional coupling with the SMF-28 fibers.

Evaluating Pfeiffer Chromatography for Its Validation as an Indicator of Soil Quality

Soil monitoring is fundamental to promote sustainability agroecosystems. It is necessary to consider indicators that bring together biological, physical, chemical and inter-relational attributes. Pfeiffer chromatography (PC) represents an important method for soil diagnosis, so the present study aims to analyze it in order to contribute to its validation. The soil samples of 12 production systems were evaluated in quintuplicate. The chromas were elaborated using Whatman no 4 filter paper, and the soil extract was performed by sodium hydroxide solution 1%. The results were obtained using revealing solution (AgNO3 0.5%) ascension by capillarity, and the chrome zones: central, internal, medium and external were correlated to soil penetration, chemical, biological and enzymatic parameters, respectively. Variance analysis was applied to the results that presented normal distribution and the means were compared by Scott-Knott test. T-test for Spearman correlations and principal component analysis were used to evaluate the correlations. There was negative correlation between the central zone and the average penetration resistance within the range 0-40 cm in depth. The internal, medium and external zones presented positive correlation with organic matter, carbon microbial biomass, and enzymatic activities, respectively. Quality standard features such as coloration, size and proportion of zones, presence of enzymatic clouds, peaks and radial lines were also confirmed. Thus, the standardization developed by this study contributed to validation of PC. Since PC is a low-cost and easy-to-perform method, it proves to be a useful tool allowing farmers autonomy to monitoring different agricultural systems, contributing to their production sustainable.

Short wavelength infrared (SWIR) spectroscopy of phyllosilicate minerals from the Tonglushan Cu-Au-Fe deposit, Eastern China: New exploration indicators for concealed skarn orebodies

The Middle–Lower Yangtze River Metallogenic Belt (MLYRB) is one of the most important Cu–Au–Fe–Mo skarn–porphyry metallogenic belts in Eastern China. After several decades of mining, the shallow-level mineral resources have been gradually exhausted, which call for new exploration tools for concealed orebodies. The Tonglushan Cu–Au–Fe skarn deposit (86.3 Mt @ 1.66% Cu, 0.94 g/t Au and 39.4% Fe) is located in the western MLYRB. Skarn alteration/mineralization are mainly hosted in the contact zone between Cretaceous (~141 Ma) quartz monzodiorite (and its porphyry) and the Lower Triassic carbonate rocks. Based on the mineral assemblages and their macro/microscopic textural relationships, the Tonglushan Cu–Au–Fe mineralization/alteration can be divided into five stages: pre-ore (S1: skarn–potassic alteration), Fe ore (S2: retrograde alteration and Fe-oxides), Cu–Au ore (S3: quartz–sulfides), carbonate alteration (S4) and supergene alteration (S5). Apart from the major skarn and retrograde alteration and carbonate minerals, abundant fine-grained phyllosilicate minerals, including chlorite, white mica (illite, muscovite and phengite), smectite (montmorillonite and saponite) and kandite (kaolinite, dickite and halloysite) group minerals have been identified at Tonglushan by SWIR spectrometry. Integrating petrographic observations and SWIR spectral analysis, four alteration zones (with distinct phyllosilicate assemblages) have been distinguished from the intrusion outward: (I) ore-barren quartz monzodiorite and its porphyry (montmorillonite–illite–chlorite), (II) endoskarn close to the skarn–hydrothermal mineralization center (montmorillonite–illite–chlorite–kaolinite–dickite), (III) skarn–hydrothermal mineralization center (saponite–chlorite), and (IV) the external contact zone in (dolomitic) marble (montmorillonite–chlorite ± kaolinite ± dickite).For the Tonglushan altered rock samples, SWIR spectrometry has identified wavelength shifts in the Fe–OH, Al–OH and sub-Al–OH absorption features of chlorite, white mica–montmorillonite and kandite, respectively. Chlorite Fe–OH absorption occurs at longer wavelengths (>2,250 nm), white mica–montmorillonite Al–OH absorption occurs at unusually long (>2,212 nm) and short (<2,202 nm) wavelengths, and kandite sub-Al–OH absorption occurs at longer wavelengths (>2,170 nm) in strongly-altered skarn proximal samples. Moreover, the presence of kaolinite, dickite, saponite, actinolite, phlogopite and/or chlorite–quartz–sulfides veins in these samples can be used as new vectors to explore deep-level mineralization centers at Tonglushan. The distribution of various kinds of phyllosilicate alteration minerals at Tonglushan, especially the white mica and kandites (with higher crystallinity) in the deep contact zones, indicates that the neutral to acidic hydrothermal fluids may have been generated with the precipitation of Fe-oxides and sulfides. This study also highlights the potential of SWIR spectroscopy of phyllosilicate minerals for exploring concealed skarn orebodies in the MLYRB.

Examining the robustness of the Ontario truck road network

Robust road transportation networks are essential to facilitate truck movements between regions. Disruptions along certain road links could degrade the network’s robustness and curtail regional commerce. A network is considered robust if the network-wide travel cost does not change significantly before and after disruptions. The network robustness index (NRI) is a well-known measure for examining the effect of reduced capacity on one or more links. It has been mainly applied to urban networks and passenger trips. In this paper, the NRI is applied to assess the robustness of the Ontario-wide truck network. Truck flows between the 49 census divisions within Ontario and 25 external zones for the year 2012 are modeled on the network of 35,254 road links and 14,444 associated nodes. Several scenarios of incrementally reduced capacity on specific critical links are devised and simulated. The NRI is calculated for each scenario to identify the level of network robustness. The locational effects of the capacity reductions were explored with the help of maps to assess the change in traffic volumes of the simulated scenarios relative to the base case. As expected, traffic diffuses or shifts to neighboring links when capacities are reduced. These results can be useful in infrastructure planning and the design of alternative routes to minimize the negative impact on traffic flows when disruptions occur.

A Glial-Neuronal Circuit in the Median Eminence Regulates Thyrotropin-Releasing Hormone-Release via the Endocannabinoid System.

SummaryBased on the type-I cannabinoid receptor (CB1) content of hypophysiotropic axons and the involvement of tanycytes in the regulation of the hypothalamic-pituitary-thyroid (HPT) axis, we hypothesized that endocannabinoids are involved in the tanycyte-induced regulation of TRH release in the median eminence (ME). We demonstrated that CB1-immunoreactive TRH axons were associated to DAGLα-immunoreactive tanycyte processes in the external zone of ME and showed that endocannabinoids tonically inhibit the TRH release in this tissue. We showed that glutamate depolarizes the tanycytes, increases their intracellular Ca2+ level and the 2-AG level of the ME via AMPA and kainite receptors and glutamate transport. Using optogenetics, we demonstrated that glutamate released from TRH neurons influences the tanycytes in the ME.In summary, tanycytes regulate TRH secretion in the ME via endocannabinoid release, whereas TRH axons regulate tanycytes by glutamate, suggesting the existence of a reciprocal microcircuit between tanycytes and TRH terminals that controls TRH release.

Diagenetic Origin of Bipyramidal Quartz and Hydrothermal Aragonites within the Upper Triassic Saline Succession of the Iberian Basin: Implications for Interpreting the Burial–Thermal Evolution of the Basin

Within the Upper Triassic successions in the Iberian Basin (Spain), the occurrence of both idiomorphic bipyramidal quartz crystals as well as pseudohexagonal aragonite crystals are related to mudstone and evaporite bearing sequences. Bipyramidal-euhedral quartz crystals occur commonly at widespread locations and similar idiomorphic crystals have been described in other formations and ages from Europe, America, Pakistan, and Africa. Similarly, pseudohexagonal aragonite crystals are located at three main sites in the Iberian Range and are common constituents of deposits of this age in France, Italy, and Morocco. This study presents a detailed description of the geochemical and mineralogical characteristics of the bipyramidal quartz crystals to decipher their time of formation in relation to the diagenetic evolution of the sedimentary succession in which they formed. Petrographic and scanning electron microscopy (SEM) analyses permit the separation of an inner part of quartz crystals with abundant anhydrite and organic-rich inclusions. This inner part resulted from near-surface recrystallization (silicification) of an anhydrite nodule, at temperatures that were &lt;40 °C. Raman spectra reveal the existence of moganite and polyhalite, which reinforces the evaporitic character of the original depositional environment. The external zone of the quartz contains no anhydrite or organic inclusions and no signs of evaporites in the Raman spectra, being interpreted as quartz overgrowths formed during burial, at temperatures between 80 to 90 °C. Meanwhile, the aragonite that appears in the same Keuper deposits was precipitated during the Callovian, resulting from the mixing of hydrothermal fluids with infiltrated waters of marine origin, at temperatures ranging between 160 and 260 °C based on fluids inclusion analyses. Although both pseudohexagonal aragonite crystals and bipyramidal quartz appear within the same succession, they formed at different phases of the diagenetic and tectonic evolution of the basin: bipyramidal quartz crystals formed in eo-to mesodiagenetic environments during a rifting period at Upper Triassic times, while aragonite formed 40 Ma later as a result of hydrothermal fluids circulating through normal faults.

Late Palaeozoic strike-slip tectonics versus oroclinal bending at the SW outskirts of Baltica: case of the Variscan belt\u2019s eastern end in Poland

Geophysical and geological data from the eastern sector of the Central European Variscan belt are presented and reviewed in the regional tectonic context. Matched filtering of isostatic gravity, guided by results of spectral analysis, along with other derivatives of gravity and magnetic fields reveal a dominant WNW–ESE-trending pre-Permian structural grain in the external zones of the Variscan belt in Poland. This trend is confirmed by regional distribution of dips in Carboniferous and Devonian strata that were penetrated by boreholes beneath Permian-Mesozoic sediments. Based on these data, two alternative concepts explaining the connection of the Variscan belt and its NE foreland, those of strike-slip tectonics versus oroclinal bending, are discussed. The WNW–ESE structural trend in the Variscan foreland is parallel to a set of major strike-slip fault zones in the area, including those of Upper Elbe, Intra-Sudetic, Odra, Dolsk and Kraków-Lubliniec. These faults are considered to convey a significant dextral displacement between Laurussia and Gondwana. The revised position of the Variscan deformation front shows a similar, uninterrupted, generally WNW–ESE trend, up to the SE border of Poland, which indicates an initial continuation of the Variscan belt into the area of the present-day Western Carpathians. The geometry of the Variscan deformation front along with the pattern of the Variscan structural grain are inconsistent with the idea of an oroclinal loop affecting the external, non-metamorphic Variscan belt. However, the data presented do not entirely rule out an oroclinal loop within the Variscan internides. The still possible options are (1) a semi-oroclinal model postulating ~ 90° bending of the Variscan tectonostratigraphic zones into parallelism with the WNW–ESE strike-slip faults or (2) an orocline limited only to the belt linking the Wolsztyn High and Moravo-Silesian non- to weakly-metamorphic fold-and-thrust belt. Regardless of the kinematic model preferred, our data indicate that structural evolution of the Polish Variscides was concluded with the end-Carboniferous NNE–SSW shortening that resulted in the present-day extent of the Variscan deformation front.

Anti-Müllerian hormone and its receptor are detected in most gonadotropin-releasing-hormone cell bodies and fibers in heifer brains

Circulating concentrations of Anti-Müllerian hormone (AMH) can indicate fertility in various animals, but the physiological mechanisms underlying the effect of AMH on fertility remain unknown. We recently discovered that AMH has extragonadal functions via its main receptor, AMH receptor type 2 (AMHR2). Specifically, AMH stimulates the secretion of luteinizing hormone and follicle-stimulating hormone from bovine gonadotrophs. Moreover, gonadotrophs themselves express AMH to exert paracrine/autocrine functions, and AMH can activate gonadotropin-releasing-hormone (GnRH) neurons in mice. This study aimed to evaluate whether AMH and AMHR2 are detected in areas of the brain relevant to neuroendocrine control of reproduction: the preoptic area (POA), arcuate nucleus (ARC), and median eminence (ME), and in particular within GnRH neurons. Reverse transcription-polymerase chain reaction detected both AMH and AMHR2 mRNA in tissues containing POA, as well as in those containing both ARC and ME, collected from postpubertal heifers. Western blotting detected AMH and AMHR2 protein in the collected tissues. Triple fluorescence immunohistochemistry revealed that most cell bodies or fibers of GnRH neurons were AMHR2-positive and AMH-positive, although some were negative. Immunohistochemistry revealed that 75% to 85% of cell bodies and fibers of GnRH neurons were positive for both AMH and AMHR2 in the POA, ARC, and both the internal and external zones of the ME. The cell bodies of GnRH neurons were situated around other AMH-positive cell bodies or fibers of GnRH and non-GNRH neurons. Our findings thus indicate that AMH and AMHR2 are detected in most cell bodies or fibers of GnRH neurons in the POA, ARC, and ME of heifer brains. These data support the need for further study as to how AMH and AMHR2 act within the hypothalamus to influence GnRH and gonadotropin secretion.

New U-Pb (SHRIMP) and first Hf isotope constraints on the Tonian (1000-920 Ma) Cariris Velhos event, Borborema Province, NE Brazil

Abstract Orthogneisses associated with metavolcanosedimentary successions related to the 1000 - 920 Ma Cariris Velhos event occur mainly in a ca. 700 km-long sigmoidal-shaped belt that crosscuts the Transversal Zone of the Borborema Province and extends to the fold belts located in its southern or external zone (part of the Riacho do Pontal and Sergipano orogens). Despite its importance, the tectonic setting and the role of those rocks in the geological evolution of the Borborema Province are contentious and not yet well understood. New zircon U-Pb SHRIMP data on an augen-gneiss sill of the Afeicao Suite intruding mica-schists mapped as part of the Santa Filomena Complex yielded a Concordia Age of 974 ± 11 Ma, indicating that at least part of the metasedimentary rocks in the internal zone of the Riacho do Pontal Orogen are Tonian or older and possibly related to the Cariris Velhos event. Hf-in-zircon isotope data are presented for the first time for Cariris Velhos-related ortho-derived rocks of the Afeicao Suite. Analyzed samples yielded eHf(t) in a narrow range between -1.51 and +2.41, with associated TDMHf of 1.6-1.4 Ga, similar to previously obtained Nd isotope data with eNd(t) = -1.0 to +3.1 and TDMNd of 1.5-1.2 Ga. A possible scenario to explain both the geochemical features and the moderately juvenile to slightly evolved, near-chondritic Hf and Nd isotope signatures is a continental arc setting, where fractionated melts produced in the supra-subduction zone mantle wedge carrying a Tonian juvenile signature became contaminated with discrete amounts of Archean-Paleoproterozoic continental crust during ascent, producing Mesoproterozoic model ages which represent the mixture of those two end-members.

Flow of partially molten crust controlling construction, growth and collapse of the Variscan orogenic belt: the geologic record of the French Massif Central

We present here a tectonic-geodynamic model for the generation and flow of partially molten rocks and for magmatism during the Variscan orogenic evolution from the Silurian to the late Carboniferous based on a synthesis of geological data from the French Massif Central. Eclogite facies metamorphism of mafic and ultramafic rocks records the subduction of the Gondwana hyperextended margin. Part of these eclogites are forming boudins-enclaves in felsic HP granulite facies migmatites partly retrogressed into amphibolite facies attesting for continental subduction followed by thermal relaxation and decompression. We propose that HP partial melting has triggered mechanical decoupling of the partially molten continental rocks from the subducting slab. This would have allowed buoyancy-driven exhumation and entrainment of pieces of oceanic lithosphere and subcontinental mantle. Geochronological data of the eclogite-bearing HP migmatites points to diachronous emplacement of distinct nappes from middle to late Devonian. These nappes were thrusted onto metapelites and orthogneisses affected by MP/MT greenschist to amphibolite facies metamorphism reaching partial melting attributed to the late Devonian to early Carboniferous thickening of the crust. The emplacement of laccoliths rooted into strike-slip transcurrent shear zones capped by low-angle detachments from c. 345 to c. 310 Ma is concomitant with the southward propagation of the Variscan deformation front marked by deposition of clastic sediments in foreland basins. We attribute these features to horizontal growth of the Variscan belt and formation of an orogenic plateau by gravity-driven lateral flow of the partially molten orogenic root. The diversity of the magmatic rocks points to various crustal sources with modest, but systematic mantle-derived input. In the eastern French Massif Central, the southward decrease in age of the mantle- and crustal-derived plutonic rocks from c. 345 Ma to c. 310 Ma suggests southward retreat of a northward subducting slab toward the Paleotethys free boundary. Late Carboniferous destruction of the Variscan belt is dominantly achieved by gravitational collapse accommodated by the activation of low-angle detachments and the exhumation-crystallization of the partially molten orogenic root forming crustal-scale LP migmatite domes from c. 305 Ma to c. 295 Ma, coeval with orogen-parallel flow in the external zone. Laccoliths emplaced along low-angle detachments and intrusive dykes with sharp contacts correspond to the segregation of the last melt fraction leaving behind a thick accumulation of refractory LP felsic and mafic granulites in the lower crust. This model points to the primordial role of partial melting and magmatism in the tectonic-geodynamic evolution of the Variscan orogenic belt. In particular, partial melting and magma transfer (i) triggers mechanical decoupling of subducted units from the downgoing slab and their syn-orogenic exhumation; (ii) the development of an orogenic plateau by lateral flow of the low-viscosity partially molten crust; and, (iii) the formation of metamorphic core complexes and domes that accommodate post-orogenic exhumation during gravitational collapse. All these processes contribute to differentiation and stabilisation of the orogenic crust.

Linearno toplotno širenje građevinskog kamena poreklom iz plutonskih magmatskih kompleksa Eksterne vardarske zone Srbije

Thermal properties of the building stone used for cladding and flooring, especially in exteriors, are significant for durability and lifespan of buildings' surfaces covered with it, but also their aesthetic properties in the sense of integrity. Linear thermal expansion of natural stone units is determined in laboratory examinations, aiming to provide the value of yield between the units as free space for their dilatation and contraction upon temperature oscillations. Where this space is not provided, diurnal changes, especially temperature increase, create stone expansion and tension which can lead to deformations of stone units and mar units' and covered surfaces' integrity and aesthetics. Data on linear thermal expansion values of natural stone, especially from Serbia, are very rare in the literature, so our aim is to contribute to this type of knowledge. Examination of thermal dilatation of stone originating from eight plutonic massifs in External Vardar zone of Serbia has shown that the values are very small, parts of millimetres, and lower than those of the similar rock types originating from China, Brazil and Eastern Serbia. A clear grouping of the values of thermal expansion of the stone according to the genetic groups to which the plutons belong to can be observed. Mineral composition, grain size and presence of metallic minerals in samples have shown no clear influence on thermal dilatation values, but fabric inhomogeneity appears to cause the increase of these values.