Branching patterns of the afferent branchial arteries and their phylogenetic significance in rays (Batoidea)

Rays of the superorder Batoidea comprise the most diverse group of chondrichthyans in terms of valid species and morphological disparity. Up to the present little agreement is observed in studies based on morphological and molecular data focused on uncovering the interrelationships within Batoidea. Morphology-based phylogenies of batoids have not included characters related to the afferent branchial arteries, and little is known about the variation in this anatomical complex in rays. Herein, representatives of 32 genera from 19 families currently recognized of rays were examined as well as some shark taxa. Seven new characters are proposed and tested in two different analyses, one on their own and in the other they were added to the morphological data matrix of the most recent analysis of interrelationships within Batoidea. The arrangement of afferent branchial arteries differs mainly among orders and families of batoids. The absence of a common trunk from which the three posteriormost afferent arteries branch is interpreted as a synapomorphy for Myliobatiformes and the presence of a coronary cranial artery as an autapomorphy for Mobula hypostoma. A close spatial relationship between the second and third afferent arteries within the common branch from the ventral aorta is proposed as a synapomorphy for Rajiformes with a secondary modification in Sympterygia. Data about patterns in afferent branchial arteries in additional taxa such as Squaliformes and Chimaeriformes are needed to better understand the evolution of this character complex among chondrichthyans.

Metamorphic rocks from the north-eastern part of the Ereendavaa terrane (Eastern Mongolia) :

In this paper, we have conducted geochronological and geochemical studies on the metamorphic rocks of the Khaychingol and Ereendavaa Formations in the Mogoitiin Gol, Khaychin Gol and Emgentiin Bulag areas from the Ereendavaa terrane and these rocks have been considered to be Precambrian in age. However, new LA–ICP–MS zircon U–Pb dating results indicate that the protolith of the studied metamorphic rocks was formed in two stages: 1) during ~ 296 - 285 Ma, the protolith of mafic, felsic and black schists formed; 2) during ~276 - 271 Ma, the protolith of gneiss and psammitic schists began to deposit. The Early Permian bimodal association composed of low-K basalt and comagmatic high-Na, low-K dacite with high-K calc-alkaline rhyolite, represent protolith of the mafic and felsic schists which were formed in back-arc basin environment. The Middle Permian gneiss, and psammitic schists with sedimentary protolith have geochemical signatures of island arc rocks, such as enrichment of LILE relative to HFSE, and markedly negative Nb, Ta and Ti anomalies, suggesting that they were formed in a continental arc environment. Considering a close spatial relationship of the Ereendavaa terrane with the Mongol-Okhotsk Belt in the north-west, we propose that accompanied with the emplacement of arc magmatic rocks, the arc rifting occurred and formed the Early Permian bimodal volcanic rocks. In the Late Permian, after the formation of the back-arc basin, deposition of the immature deposits as wacke, arkose and litharenite dominated sediments in a continental arc environment started.

Dissecting the default mode network: direct structural evidence on the morphology and axonal connectivity of the fifth component of the cingulum bundle

OBJECTIVEAlthough a growing body of data support the functional connectivity between the precuneus and the medial temporal lobe during states of resting consciousness as well as during a diverse array of higher-order functions, direct structural evidence on this subcortical circuitry is scarce. Here, the authors investigate the very existence, anatomical consistency, morphology, and spatial relationships of the cingulum bundle V (CB-V), a fiber tract that has been reported to reside close to the inferior arm of the cingulum (CingI).METHODSFifteen normal, formalin-fixed cerebral hemispheres from adults were treated with Klingler’s method and subsequently investigated through the fiber microdissection technique in a medial to lateral direction.RESULTSA distinct group of fibers is invariably identified in the subcortical territory of the posteromedial cortex, connecting the precuneus and the medial temporal lobe. This tract follows the trajectory of the parietooccipital sulcus in a close spatial relationship with the CingI and the sledge runner fasciculus. It extends inferiorly to the parahippocampal place area and retrosplenial complex area, followed by a lateral curve to terminate toward the fusiform face area (Brodmann area [BA] 37) and lateral piriform area (BA35). Taking into account the aforementioned subcortical architecture, the CB-V allegedly participates as a major subcortical stream within the default mode network, possibly subserving the transfer of multimodal cues relevant to visuospatial, facial, and mnemonic information to the precuneal hub. Although robust clinical evidence on the functional role of this stream is lacking, the modern neurosurgeon should be aware of this tract when manipulating cerebral areas en route to lesions residing in or around the ventricular trigone.CONCLUSIONSThrough the fiber microdissection technique, the authors were able to provide original, direct structural evidence on the existence, morphology, axonal connectivity, and correlative anatomy of what proved to be a discrete white matter pathway, previously described as the CB-V, connecting the precuneus and medial temporal lobe.

New Constraints on the Timing and History of Breccia Dikes in the Western San Juan Mountains, Southwestern Colorado

In the western San Juan Mountains, clastic (breccia) dikes crop out in Paleozoic to Cenozoic rocks. The dikes are tabular to bifurcating masses up to several meters thick and are exposed on northwest or northeast trends for up to several kilometers. They are matrix- to clast-supported with angular to rounded pebble- to boulder-sized fragments that in most dikes are dominated by Proterozoic igneous and metamorphic rocks. U-Pb age analyses (n = 3) reveal a range of zircon ages in all samples with several containing high proportions of 1820 to 1390 Ma zircons. The majority of Proterozoic zircons are interpreted as direct contributions from basement rocks during breccia dike formation and emplacement. Field relations and U-Pb zircon analyses reveal that breccia dikes formed in intervals from 65 to 30 Ma (Ouray) and 27 to 12 Ma (Stony Mountain); some dikes are closely allied with mineralization. The dikes formed at depths over 500 meters where Proterozoic basement was fragmented, entrained, and transported to higher structural levels along with pieces of Paleozoic to Cenozoic rocks. A close spatial relationship exists between breccia dikes and latest Mesozoic to Cenozoic plutons. This is best exemplified near Ouray where clastic dikes share similar trends with ~65 Ma granodiorite dikes, and there is a clear transition from intrusive rocks to altered-brecciated plutons, and finally to breccia dikes. The preponderance of evidence supports breccia dike formation via degassing and explosive release of CO2-charged volatiles on deep fractures related to emplacement of 70 to 4 Ma plutons or mantle melts. In addition to breccia dikes, several post-80 Ma events in the region involved explosive release of volatile-charged magmas: 29-27 Ma calderas, ~25 Ma diatremes, and ~24 Ma breccia pipes. Causal factors for production of these gas-charged magmas remain poorly understood, but partial melting or assimilation of altered and metasomatized lithospheric mantle could have played a role.

Metal worker’s lung: spatial association with Mycobacterium avium

BackgroundOutbreaks of hypersensitivity pneumonitis (HP) are not uncommon in workplaces where metal working fluid (MWF) is used to facilitate metal turning. Inhalation of microbe-contaminated MWF has been assumed to be the cause, but previous investigations have failed to establish a spatial relationship between a contaminated source and an outbreak.ObjectivesAfter an outbreak of five cases of HP in a UK factory, we carried out blinded, molecular-based microbiological investigation of MWF samples in order to identify potential links between specific microbial taxa and machines in the outbreak zone.MethodsCustom-quantitative PCR assays, microscopy and phylogenetic analyses were performed on blinded MWF samples to quantify microbial burden and identify potential aetiological agents of HP in metal workers.Measurements and main resultsMWF from machines fed by a central sump, but not those with an isolated supply, was contaminated by mycobacteria. The factory sump and a single linked machine at the centre of the outbreak zone, known to be the workstation of the index cases, had very high levels of detectable organisms. Phylogenetic placement of mycobacterial taxonomic marker genes generated from these samples indicated that the contaminating organisms were closely related to Mycobacterium avium.ConclusionsWe describe, for the first time, a close spatial relationship between the abundance of a mycobacterium-like organism, most probably M. avium, and a localised outbreak of MWF-associated HP. The further development of sequence-based analytic techniques should assist in the prevention of this important occupational disease.

The visible dead: dolmens and the landscape in Early Bronze Age Jordan

Overview:Dolmens are usually described as part of a regional megalithic phenomenon that spanned the 5th-2nd millennia BC. However, this presentation assumes that most ‘dolmens’ are mis-identified. When strictly defined, dolmens better reflect a local funerary tradition of the 4th millennium BC.Definitions:The term dolmen includes a variety of features whose only similarity is their use of large stone slabs. This presentation defines a dolmen as a freestanding,rectangular chamber formed by two upright orthostats along each long side, and a single roof slab over the top. Dolmens have often been conflated with cairns. This presentation defines a cairn as a large pile of small stones. Such features may have contained a low, cist burial chamber; others may simply be piles of field clearance.Distribution:Dolmens, as defined above, concentrate within a limited area of the east rift escarpment of the Jordan Valley, consistent with a local funerary tradition.Chronology: Recent dolmen excavations have yielded assemblages that date exclusively to the EB I (c.3700-3000 BC). This talk examines the close spatial relationship between dolmens and EB I settlement sites in a discrete geographical zone.

Corrigendum to: Phosphate minerals in granitic pegmatites from the Mount Wills District, north-eastern Victoria

Tin- and tantalum-bearing LCT-type granitic pegmatites occur in a 45 km long belt between Eskdale and Mount Wills in north-eastern Victoria. Near Mount Wills, several compositionally zoned rare-element pegmatites contain complex assemblages of primary and secondary phosphate minerals, many of which are rare and previously unrecorded in Victoria. The phosphate assemblages can be divided into Al-rich and Fe–Mn-rich suites, in addition to ubiquitous fluorapatite. The Al-rich phosphate suite includes montebrasite, scorzalite, bertossaite and brazilianite. The Fe‒Mn phosphate suite includes heterosite, phosphoferrite, wolfeite, alluaudite (sp.), arrojadite (sp.) and jahnsite (sp.), derived from the metasomatic alteration of primary triplite. Further hydrothermal alteration of this assemblage has resulted in a secondary suite of strengite, rockbridgeite, phosphosiderite, whiteite, jahnsite and whitmoreite forming in etch cavities and fractures. A Late Silurian age of 420±4 Ma was obtained from one of the dykes via CHIME radiometric dating of monazite, suggesting a similar age for the adjacent Mount Wills Granite, which has not been reliably dated. This highly fractionated, peraluminous granite is presumed to be the source of the rare-element pegmatites based on their close spatial relationship.

An unusual sponge – microbe – synsedimentary cement framework in a Late Ordovician reef, Southampton Island (Nunavut, Canada)

A large, resistant buildup at the top of the Upper Ordovician (Hirnantian?) Red Head Rapids Formation on Southampton Island (Nunavut, Arctic Canada) is dominated by massive boundstone and cementstone facies. These massive facies have more in common with the sponge–microbial reefs that dominated worldwide in the Early Ordovician, including the following primary components: early calcified sponge material, microbial elements, and synsedimentary cement. A close spatial relationship between sponge and microbial framework elements suggests that a poorly preserved decaying sponge framework provided substrates for the attachment and development of microbes and that the microbes played essential roles as reef consolidators. Centimetre-scale colonial metazoans are present and locally intergrown with the sponge and microbial components. Other mound-dwelling invertebrates or calcareous algae are rare. Although altered now to calcite, cement fabrics suggest that aragonite was ubiquitous as seafloor precipitate. Prior to its subaerial exposure in the latest Ordovician, the Red Head Rapids Formation buildup developed on the margin of a shallow-marine evaporative epicratonic basin where a diverse community of reef-building metazoans was unable to flourish.

Tracing CD34+ Stromal Fibroblasts in Palatal Mucosa and Periodontal Granulation Tissue as a Possible Cell Reservoir for Periodontal Regeneration

The aim of the present research was to trace CD34+ stromal fibroblastic cells (CD34+ SFCs) in the palatal connective tissue harvested for muco-gingival surgical procedures and in granulation tissues from periodontal pockets using immunohistochemical and transmission electron microscopy. Immunohistochemical analysis targeted the presence of three antigens: CD31,α-smooth muscle actin (α-SMA), and CD34. In the palate, CD31 staining revealed a colored inner ring of the vessels representing the endothelium,α-SMA+ was located in the medial layer of the vasculature, and CD34 was intensely expressed by endothelial cells and artery adventitial cells (considered to be CD34+ SFCs). Granulation tissue showed the same pattern for CD31+ andα-SMA, but a different staining pattern for CD34. Ultrastructural examination of the palatal tissue highlighted perivascular cells with fibroblast-like characteristics and pericytes in close spatial relationship to endothelial cells. The ultrastructural evaluation of granulation tissue sections confirmed the presence of neovasculature and the inflammatory nature of this tissue. The present study traced the presence of CD34+ SFCs and of pericytes in the palatal connective tissue thus highlighting once more its intrinsic regenerative capabilities. The clinical and systemic factors triggering mobilization and influencing the fate of local CD34+SCFs and other progenitors are issues to be further investigated.

Phosphate minerals in granitic pegmatites from the Mount Wills District, north-eastern Victoria

Tin- and tantalum-bearing LCT-type granitic pegmatites occur in a 45 km long belt between Eskdale and Mount Wills in north-eastern Victoria. Near Mount Wills, several compositionally zoned rare-element pegmatites contain complex assemblages of primary and secondary phosphate minerals, many of which are rare and previously unrecorded in Victoria. The phosphate assemblages can be divided into Al-rich and Fe–Mn-rich suites, in addition to ubiquitous fluorapatite. The Al-rich phosphate suite includes montebrasite, scorzalite, bertossaite and brazilianite. The Fe‒Mn phosphate suite includes heterosite, phosphoferrite, wolfeite, alluaudite (sp.), arrojadite (sp.) and jahnsite (sp.), derived from the metasomatic alteration of primary triplite. Further hydrothermal alteration of this assemblage has resulted in a secondary suite of strengite, rockbridgeite, phosphosiderite, whiteite, jahnsite and whitmoreite forming in etch cavities and fractures. A Late Silurian age of 420±4 Ma was obtained from one of the dykes via CHIME radiometric dating of monazite, suggesting a similar age for the adjacent Mount Wills Granite, which has not been reliably dated. This highly fractionated, peraluminous granite is presumed to be the source of the rare-element pegmatites based on their close spatial relationship.