Memoirs: On Certain Features in the Development of the Alimentary Canal in Lepidosiren and Protopterus

1910 ◽  
Vol s2-54 (216) ◽  
pp. 483-518
Author(s):  
J. GRAHAM KERR
Keyword(s):  
Main Part ◽  
Alimentary Canal ◽  
Buccal Cavity ◽  
Ventral Side ◽  
Main Mass ◽  
Lower Jaw ◽  
Right Lobe ◽  
Dorsal Mesentery

1. The fore-gut first becomes folded off from the main mass of yolk-cells. 2. The pyloric valve arises by the hind end of the fore-gut being pushed back into the cavity oE the mid-gut. 3. The main mass of yolk-cells becomes gradually "modelled" into a spirally-coiled intestinal rudiment. 4. The main part of the buccal lining is developed in situ from large yolk-cells. 5. The part of the ventral side of the head, on which, are the olfactory rudiments, becomes enclosed in the buccal cavity by the development of the upper lips and by the forward growth of the lower jaw. 6. The olfactory opening becomes divided into anterior and posterior tiares by the apposition and fusion of the intermediate portion of its lips. 7. The thyroid arises as a solid downgrowth from the buccopharyngeal floor, which gradually becomes cut off from behind forwards. 8. The tongue is a primary tongue like that of Urodeles, but without gland-field. 9. The lung arises from a solid mid-ventral rudiment. 10. When the lung becomes bilobed, the (actual) right lobe is for a time small in size as compared with its fellow. 11. Complicated torsional processes take place during the development of the lung. 12. Through the dorsal mesentery becoming partially merged in the splanchnocoele roof, the lungs come to lie outside the splanchnocoele.

scholarly journals Experimental tests of the impact of selected parameters on the indentation rolling resistances

2018 ◽  
Vol 29 ◽  
pp. 00002 ◽  
Author(s):  
Dariusz Woźniak ◽  
Lech Gładysiewicz ◽  
Martyna Konieczna
Keyword(s):  
Main Part ◽  
Rolling Resistance ◽  
Experimental Tests ◽  
Conveyor Belt ◽  
Significant Component ◽  
Different Types ◽  
Indentation Rolling Resistance ◽  
Belt Conveyors ◽  
The Impact

Belt conveyors are main part of transporting systems in mines and in many other branches of industry. During conveyor belt works different types of resistances are generated. Indentation rolling resistance is the most significant component of the resistances from the perspective of energy losses and it cause the biggest costs as well. According to latest state of analyses and measurements it is well known that theoretical rolling resistance were underestimated in comparison with the measured in-situ one. In this paper new method for determination indentation rolling resistance is presented. The authors compared theoretically and experimentally established damping factors. The relation between these two values enabled to obtain more precise equation for damping function. This function is one of the most important component in calculation of the rolling resistance. In new theoretical model value of rolling resistance is nearly twice higher than this used so far.

Cranial anatomy of tadpoles of five species of Scinax (Hylidae, Hylinae)

Zootaxa ◽  
2011 ◽  
Vol 2787 (1) ◽  
pp. 19 ◽  
Author(s):  
LEANDRO ALCALDE ◽  
FLORENCIA VERA CANDIOTI ◽  
FRANCISCO KOLENC ◽  
CLAUDIO BORTEIRO ◽  
DIEGO BALDO
Keyword(s):  
Buccal Cavity ◽  
Morphological Data ◽  
Sister Taxon ◽  
Anatomical Features ◽  
Interspecific Relationships ◽  
Lower Jaw ◽  
Lateral Ridge ◽  
Source Of Information

We studied the oral apparatus, buccal cavity and musculoskeletal features in tadpoles of five species of the genus Scinax (S. acuminatus, S. uruguayus, S. aff. pinima, S. aromothyella, and S. berthae). Observed variation is mainly related to intrageneric grouping. Scinax acuminatus (S. ruber clade, sister taxon of S. rostratus group) has a distinctive combination of a mental gap in the margin of oral papillae, straight labial teeth with few or absent cusps, processus muscularis acute and posteriorly directed, and m. subarcualis rectus I with two slips. Scinax uruguayus and S. aff. pinima (S. uruguayus group) have keratinized sheets ventrolateral to the lower jaw sheath, well-developed infralabial and lateral ridge papillae, robust jaw cartilages, cornua trabeculae with short and widely divergent free portions, processus articularis short and wide, processus muscularis thin and directed anteriorly. Scinax aromothyella and S. berthae (S. catharinae group) have poorly developed, non-colored spurs behind the lower jaw sheath, long and thin processus articularis, wide and rounded processus muscularis, and tripartite cartilago suprarostralis. Anatomical features described are congruent with current phylogenetic arrangements based on molecular, chromosomal, and morphological data, and provide a source of information that can be useful to solve interspecific relationships within Scinax.

scholarly journals A retinoic acid responsive gene MK found in the teratocarcinoma system is expressed in spatially and temporally controlled manner during mouse embryogenesis.

1990 ◽  
Vol 110 (3) ◽  
pp. 607-616 ◽  
Author(s):  
K Kadomatsu ◽  
R P Huang ◽  
T Suganuma ◽  
F Murata ◽  
T Muramatsu
Keyword(s):  
Retinoic Acid ◽  
Embryonal Carcinoma ◽  
Anterior Lobe ◽  
Carcinoma Cells ◽  
Embryonic Induction ◽  
Mouse Embryogenesis ◽  
Epithelial Tissues ◽  
Lower Jaw ◽  
The Brain

A newly identified gene MK is transiently expressed in early stages of retinoic acid-induced differentiation of embryonal carcinoma cells (Kadomatsu, K., M. Tomomura, and T. Muramatsu, 1988. Biochem. Biophys. Res. Commun. 151:1312-1318). MK gene has been predicted to code a polypeptide that is rich in basic amino acids and cysteine and is not related to any other peptides so far reported. In the present study, we investigated MK expression during mouse embryogenesis by in situ hybridization. The MK transcript was detected all over the embryo proper of the 7-d embryo, while it was not detectable in the 5-d embryo. The ubiquitous expression continued in the 9-d embryo proper. On the 11th-13th d of gestation, the sites where MK gene was intensely expressed became progressively restricted; these sites were the brain ectoderm around the lens and brain ventricles, the anterior lobe of the pituitary gland, the upper and lower jaw, the caudal sclerotomic half of vertebral column, the limbs, the stomach, and the epithelial tissues of the lung, the pancreas, the small intestine, and the metanephros. These areas include the region where secondary embryonic induction is prominent. In the 15-d embryo, only the kidney expressed MK significantly. These data suggest that MK gene plays a fundamental role in the differentiation of a wide variety of cells; MK gene may also play some specific roles in generation of epithelial tissues, and remodeling of mesoderm.

Jaws and radula of the Carboniferous ammonoid Cravenoceras

1995 ◽  
Vol 69 (4) ◽  
pp. 703-707 ◽  
Author(s):  
Kazushige Tanabe ◽  
Royal H. Mapes
Keyword(s):  
The Body ◽  
Anterior Portion ◽  
Phylogenetic Affinity ◽  
Body Chamber ◽  
Lower Jaw ◽  
Upper Jaw ◽  
Marginal Plates ◽  
Buccal Space

A well-preserved mouth apparatus consisting of jaws and a radula was found in situ within the body chamber of the goniatite Cravenoceras fayettevillae Gordon, 1965 (Neoglyphiocerataceae: Cravenoceratidae), from the middle Chesterian (Upper Mississippian) of Arkansas. Both upper and lower jaws consist of a black material. The lower jaw is characterized by a widely opened larger outer lamella and a shorter inner lamella. The upper jaw is fragmental. The radula is preserved in the anterior portion of the buccal space and comprises a series of tooth elements. Each transverse tooth row consists of seven teeth (a rhachidian and pairs of two lateral and one marginal teeth), with a pair of marginal plates. This arrangement is typical of radulae of other ammonoids of Carboniferous to Cretaceous age, coleoids, and the orthoconic “nautiloid” Michelinoceras (Silurian, Michelinocerida), suggesting a phylogenetic affinity among them.

Differential effects of somatostatin analogues on alpha- and beta-cells of the pancreas.

1979 ◽  
Vol 236 (2) ◽  
pp. E123 ◽  
Author(s):  
G J Taborsky ◽  
P H Smith ◽  
D Porte
Keyword(s):  
Beta Cell ◽  
Structural Changes ◽  
Glucagon Secretion ◽  
Somatostatin Analogues ◽  
Pancreatic Insulin ◽  
Insulin And Glucagon Secretion ◽  
Right Lobe ◽  
The Right ◽  
Slight Inhibition

We examined the effect of somatostatin (SS) and its analogues on basal insulin and glucagon output from the right lobe of the in situ canine pancreas. Somatostatin (0.17 and 1.7 microgram/min, iv) significantly inhibited insulin (delta = -48 +/- 9% and delta = -88 +/- 3%) and glucagon (delta = -13 +/- 16%, P = NS and delta = -55 +/- 8%). Des-Asn5-SS Significantly inhibited insulin (delta = -40 +/- 9% and delta = -92 +/- 3%) but not glucagon (delta = +35 +/- 18% and delta = +4 +/- 12%). Likewise, [D-Ser13]-SS significantly inhibited insulin (delta = -40 +/- 14% and delta = -71 +/- 8%) with only slight inhibition of glucagon (delta = +26 +/- 15%, P = NS and delta = -16 +/- 6%, P less than 0.05). In contrast, [D-Cys14]-SS significantly inhibited both inhibited both insulin and glucagon. We conclude that structural changes of cyclic somatostatin can dissociate its ability to inhibit pancreatic insulin and glucagon secretion. Because the putative receptors on the pancreatic alpha- and beta-cell appear to recognize different configurations of the somatostatin molecule, it is suggested that the receptors themselves are different.

Three Combe-Capelle Hand-Axes from Norfolk

1935 ◽  
Vol 1 ◽  
pp. 98-100
Author(s):  
J. E. Sainty
Keyword(s):  
Cross Effect ◽  
Main Mass ◽  
Northern Border ◽  
Upper Face ◽  
Boulder Clay

Although a number of specimens of Combe-Capelle type are recorded for the Gipping Valley above Ipswich few have so far been recognised in Norfolk. Fig. 1 shows the various aspects of a beautiful specimen found by Mr J. H. Capon in a shallow working for gravel on Mousehold Heath, on the northern border of Norwich. Dr. J. D. Solomon examined the section and reports:— ‘The deposit in which Mr Capon found the implement is a portion of the upper gravel of Mousehold Heath, which contains outwash from the Chalky Boulder Clay and is clearly of Great Eastern date. But the actual portion, in which the implement was found, has clearly been disturbed and re-arranged by solifluxion, perhaps of Little Eastern date. The implement is therefore, not to be considered as in situ in the main mass of the gravel.’It is of fine quality flint. The flatter face (fig. 1 c) is white and porcellanous, highly lustred, and showing two small patches of cortex. The flaking is flat in the extreme, only two of the scars showing resolved flaking. The upper face (fig. 1A) shows grey flint with distinct bluish patina, particularly towards the edges, fine white lines meandering over the whole surface, giving a typical criss-cross effect; some of the flaking is heavily resolved whilst the edges show a rather nibbling re-touch.

scholarly journals Occurrence of Two Distinct Urotensin II-Related Peptides in Zebrafish Provides New Insight into the Evolutionary History of the Urotensin II Gene Family

Endocrinology ◽  
2011 ◽  
Vol 152 (6) ◽  
pp. 2330-2341 ◽  
Author(s):  
Caroline Parmentier ◽  
Emilie Hameury ◽  
Christophe Dubessy ◽  
Feng B. Quan ◽  
Damien Habert ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Close Contact ◽  
Ventral Side ◽  
Pcr Analysis ◽  
Urotensin Ii ◽  
Rt Pcr ◽  
History Of ◽  
The Brain ◽  
Insight Into

The urotensin II (UII) family is currently known to consist of two paralogous peptides, namely UII and UII-related peptide (URP). In contrast to UII, which has been identified in all vertebrate classes so far, URP has only been characterized in tetrapods. We report here the occurrence of two distinct URP genes in teleosts, which we have named URP1 and URP2. Synteny analysis revealed that teleost URP1 and URP2 genes and tetrapod URP genes represent three distinct paralog genes that, together with the UII gene, probably arose from the two rounds of tetraploidization, which took place early in vertebrate evolution. The absence of URP in fish indicates that the corresponding gene has been lost in the teleost lineage, whereas it is likely that both the URP1 and URP2 genes have been lost in the tetrapod lineage. Quantitative RT-PCR analysis revealed that the URP2 gene is mainly expressed in the spinal cord and the brain in adult zebrafish. In situ hybridization experiments showed that in zebrafish embryos, URP2 mRNA-containing cells are located in the floor plate of the neural tube. In adult, URP2-expressing cells occur in close contact with the ventral side of the ependymal canal along the whole spinal cord, whereas in the brain, they are located below the fourth ventricle. These URP-expressing cells may correspond to cerebrospinal fluid-contacting neurons. In conclusion, our study reveals the occurrence of four distinct UII paralogous systems in vertebrates that may exert distinct functions, both in tetrapods and teleosts.

In Situ Procurement of a Recipient's Portal Vein for a Right Lobe Liver Graft With Multiple Venous Orifices: A Case Report

2017 ◽  
Vol 49 (1) ◽  
pp. 172-174 ◽  
Author(s):  
Y. Soejima ◽  
T. Yoshizumi ◽  
T. Ikegami ◽  
N. Harimoto ◽  
N. Harada ◽  
...  
Keyword(s):  
Case Report ◽  
Portal Vein ◽  
Liver Graft ◽  
Right Lobe

scholarly journals The new ichthyosauriform Chaohusaurus brevifemoralis (Reptilia, Ichthyosauromorpha) from Majiashan, Chaohu, Anhui Province, China

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7561 ◽  
Author(s):  
Jian-dong Huang ◽  
Ryosuke Motani ◽  
Da-yong Jiang ◽  
Andrea Tintori ◽  
Olivier Rieppel ◽  
...  
Keyword(s):  
New Species ◽  
Main Part ◽  
Anterior Margin ◽  
Phylogenetic Analyses ◽  
Cranial Sutures ◽  
Neural Spine ◽  
Medial Part ◽  
Trunk Length ◽  
A New Species

A new species of ichthyosauriform is recognized based on 20 specimens, including nearly complete skeletons, and named Chaohusaurus brevifemoralis. A part of the specimens was previously identified as Chaohusaurus chaoxianensis and is herein reassigned to the new species. The new species differs from existing species of Chaohusaurus in a suite of features, such as the bifurcation of the caudal peak neural spine and a short femur relative to trunk length. The specimens include both complete and partially disarticulated skulls, allowing rigorous scrutiny of cranial sutures. For example, the squamosal does not participate in the margin of the upper temporal fenestra despite previous interpretations. Also, the frontal unequivocally forms a part of the anterior margin of the upper temporal fenestra, forming the most medial part of the anterior terrace. The skull of the holotype largely retains three-dimensionality with the scleral rings approximately in situ, revealing that the eyeball was uncovered in two different directions, that is, laterally and slightly dorsally through the main part of the orbit, and dorsally through the medial extension of the orbit into the skull roof. This skull construction is likely a basal feature of Ichthyosauromorpha. Phylogenetic analyses place the new species as a sister taxon of Chaohusaurus chaoxianensis.

Sign in / Sign up

Export Citation Format

Share Document