scholarly journals Characteristic tetrapod musculoskeletal limb phenotype emerged more than 400 MYA in basal lobe-finned fishes

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Rui Diogo ◽  
Peter Johnston ◽  
Julia L. Molnar ◽  
Borja Esteve-Altava
Keyword(s):  
Basal Lobe

Hydrochus spanglerorum n. sp., a remarkable, highly derived species from Brazil, Guyana, and Suriname (Coleoptera: Hydrochidae)

Zootaxa ◽  
2019 ◽  
Vol 4701 (6) ◽  
pp. 581-587
Author(s):  
PHILIP D. PERKINS
Keyword(s):  
New Species ◽  
Male Genitalia ◽  
Basal Lobe ◽  
A New Species

A new species of Neotropical Hydrochus, H. spanglerorum n. sp., is described, based on specimens collected in Brazil, Guyana, and Suriname. The new species has unusual external and male genitalia morphology, which are described, discussed and illustrated. Among other unusual characters, the males have markedly pitted and iridescent femora, and the male genitalia have the parameres and basal piece fused, and the aedeagus dorsal basal lobe located near the distal end of the male genitalia. 

scholarly journals Subdomain cryo-EM structure of nodaviral replication protein A crown complex provides mechanistic insights into RNA genome replication

2020 ◽  
Vol 117 (31) ◽  
pp. 18680-18691 ◽  
Author(s):  
Nuruddin Unchwaniwala ◽  
Hong Zhan ◽  
Janice Pennington ◽  
Mark Horswill ◽  
Johan A. den Boon ◽  
...  
Keyword(s):  
Protein A ◽  
Rna Replication ◽  
Replication Protein A ◽  
Replication Protein ◽  
Viral Rna ◽  
Interaction Sites ◽  
Basal Lobe ◽  
Apical Lobe ◽  
Positive Strand Rna ◽  
Em Tomography

For positive-strand RNA [(+)RNA] viruses, the major target for antiviral therapies is genomic RNA replication, which occurs at poorly understood membrane-bound viral RNA replication complexes. Recent cryoelectron microscopy (cryo-EM) of nodavirus RNA replication complexes revealed that the viral double-stranded RNA replication template is coiled inside a 30- to 90-nm invagination of the outer mitochondrial membrane, whose necked aperture to the cytoplasm is gated by a 12-fold symmetric, 35-nm diameter “crown” complex that contains multifunctional viral RNA replication protein A. Here we report optimizing cryo-EM tomography and image processing to improve crown resolution from 33 to 8.5 Å. This resolves the crown into 12 distinct vertical segments, each with 3 major subdomains: A membrane-connected basal lobe and an apical lobe that together comprise the ∼19-nm-diameter central turret, and a leg emerging from the basal lobe that connects to the membrane at ∼35-nm diameter. Despite widely varying replication vesicle diameters, the resulting two rings of membrane interaction sites constrain the vesicle neck to a highly uniform shape. Labeling protein A with a His-tag that binds 5-nm Ni-nanogold allowed cryo-EM tomography mapping of the C terminus of protein A to the apical lobe, which correlates well with the predicted structure of the C-proximal polymerase domain of protein A. These and other results indicate that the crown contains 12 copies of protein A arranged basally to apically in an N-to-C orientation. Moreover, the apical polymerase localization has significant mechanistic implications for template RNA recruitment and (−) and (+)RNA synthesis.

The capitulum and feeding mechanism of Ixodes hexagonus Leach

Parasitology ◽  
1951 ◽  
Vol 41 (1-2) ◽  
pp. 66-81 ◽  
Author(s):  
D. R. Arthur
Keyword(s):  
Lower Surface ◽  
Tissue Reaction ◽  
Lower Wall ◽  
Feeding Mechanism ◽  
External Structure ◽  
Basal Lobe ◽  
Ixodes Hexagonus ◽  
Pharyngeal Muscles ◽  
Pharyngeal Teeth

1. The external structure of the capitulum of Ixodes hexagonus is described in detail, and the differences between it and the closely allied I. cookei are noted.2. The capitulum is divisible into two portions, an extra-basis and basis regions. The former is divided into the hypostomal groove, the labrohypostomal groove and the labro-hypostomal gutter. Internally the basis is divided into dorsal and ventral chambers by the subcheliceral plate. The dorsal chamber houses the chelicerae while the pharynx and the salivary ducts occupy the ventral portion.3. The so-called ‘stylet-like process’ is the anterior prolongation from the basal lobe of the labrum, and forms the mid-rib of a lamella which divides the hypostome into a dorsal salivary channel and a ventral food conduit.4. There are rows of teeth on the internal faces of the anterior fifth of the pharynx. Two series of pharyngeal muscles are present: (i) those having a dorsal attachment to the floor of the salivary chamber, and (ii) those having similar attachments to the subcheliceral plates.5. During feeding the first incision is made by the denticulate apices of the digits and into it the hypostome is then forced. Further cutting by the digits enables the hypostome to penetrate to its base. At the same time the palps splay out. The blood is then drawn up the food conduit by the action of the sucking pharynx. The lower surface of the labrum is produced into a tooth-like projection that fits into a groove of the lower wall of the pharynx. Presumably it functions as a valve to prevent regurgitation of blood. The pharyngeal teeth may function as a supplementary valvular apparatus or else serve for the breakdown of erythrocytes.6. The tissue reaction of a stoat's skin to penetration by the capitulum of I. hexagonus is described.

TWO NEW SILPHIDÆ FROM COLORADO

1902 ◽  
Vol 34 (7) ◽  
pp. 180-181 ◽  
Author(s):  
H. F. Wickham
Keyword(s):  
Basal Lobe

Silpha Coloradensis, n. sp.– Form of inæqualis, but more elongae, black, except the tip of the abdomen, which is orange-rufocus; above clothed with short black hairs. Head densely punctate, the punctures regular over the greater part of the surface, those in front of the inter-antennal line smalll and less distinct; occipital transeverse impression deep; labrum short, broadly emarginate; antennæ black, club four-jointed, the last three joints pubesecnt, the terminal one longer, compressed, tip sinuately rounded. Thorax about one one-half times as broad as long, narrowed anteriorly, sides broadly arcuate in front, more suddenly so behind, basal lobe slightly and very broadly emarginate. Surface somewhat irregular, densely and very regularly punctate, sides somewhat flattened. Scutellum slightly concave, densely puncutred. Elytra as wide as the thorax and fully twice as long, the sides nearly parallel, outer margins distinctly reflexed, apices conjointly rounded, but sinuate externally, punctuation less dense than that of the thorax, each puncture with a recumbent hair.

First extinct genus of a flea (Siphonaptera: Pulicidae) in Miocene amber from the Dominican Republic

Zootaxa ◽  
2012 ◽  
Vol 3438 (1) ◽  
pp. 54 ◽  
Author(s):  
VINCENT PERRICHOT ◽  
JEAN-CLAUDE BEAUCOURNU ◽  
JÜRGEN VELTEN
Keyword(s):  
Terminal Segment ◽  
Greater Antilles ◽  
Maxillary Palpus ◽  
Dorsal Margin ◽  
Abdominal Sternite ◽  
Basal Lobe ◽  
Tarsal Claw ◽  
History Of ◽  
Reduced Space ◽  
Extinct Genus

A new, extinct genus of flea is described and figured in the tribe Spilopsyllini (Siphonaptera: Pulicidae) from a male preserved in Early Miocene Dominican amber. Eospilopsyllus kobberti Beaucournu & Perrichot, n. gen. and n. sp., is characterized by the absence of ctenidia, very small eyes, lanceolate terminal segment of the maxillary palpus, enlarged second abdominal sternite, legs with six notches on dorsal margin of tibiae, five pairs of lateral plantar bristles on distitarsomeres, and ungues with a reduced space between the basal lobe and the tarsal claw. Most of the extant spilopsyllines parasitize lagomorphs and squirrels, but these taxa were seemingly absent from the Greater Antilles until very recently. Instead, the Tertiary record and biogeographical history of land mammals on these islands suggests that early spilopsyllines may have parasitized the endemic solenodon insectivores or echimyid rats.

Lestodiplosis alvei sp.n. (Diptera, Cecidomyidae)

Parasitology ◽  
1934 ◽  
Vol 26 (4) ◽  
pp. 594-595
Author(s):  
H. F. Barnes
Keyword(s):  
Regular Ring ◽  
Distal Segment ◽  
Flagellar Segment ◽  
Proximal Segment ◽  
Basal Enlargement ◽  
Basal Lobe ◽  
Moderate Length

Male. Length about 1·5 mm. Antennae slightly longer than head, thorax and abdomen: 2 + 12, basal enlargement of flagellar segments with regular ring of moderately long stout setae and one ring of circumfila, distal enlargement with two rings of circumfila and irregular ring of stout setae, loops of circumfila regular and moderately long, those on basal enlargement extending about one-third length of stem, distal ring on distal enlargement extending about two-thirds length of neck; 1st and 2nd flagellar segments fused; 3rd flagellar segment with stem about three times as long as broad, neck slightly longer, about three-and-a-half times as long as broad, distal end slightly darkened as on all flagellar segments; 10th flagellar segment with stem about four times as long as broad, neck slightly longer in proportion. Palpi quadriarticulate with few setae: proximal segment quadrate, 2nd just over three times as long as broad, 3rd about three times as long as broad, the same width as 2nd, distal segment about four times as long as broad, slightly narrower than two previous segments. Thorax brown. Wings hyaline; 3rd vein reaching margin at apex of wing. Legs hairy; claws moderately curved, simple; empodium slightly shorter than claws. Genitalia: basal clasp segment long narrow, small basal lobe prominent; distal clasp segment long narrow, darkened; dorsal lamella moderate length and breadth, distinctly longer than ventral lamella, deeply emarginate, each lobe rounded; ventral lamella comparatively short but broad; style long, moderately stout.

scholarly journals A case of postpartum maternal death with COVID-19 in the west of Iran

2020 ◽  
Author(s):  
Maryam Ahmadi ◽  
Mehrangiz Zamani bonab ◽  
Sorour Akbari ◽  
Hamideh parsapour ◽  
Shohreh Alimohammadi ◽  
...  
Keyword(s):  
Gestational Age ◽  
Left Lung ◽  
Chain Reaction ◽  
Pharyngeal Swab ◽  
Healthy Baby ◽  
Case Presentation ◽  
Cough Headache ◽  
Basal Lobe ◽  
Chief Complaints ◽  
Polymerase Chain

Abstract Background: There are a limited number of studies about COVID-19 during delivery and postpartum.Case presentation: A 38-years old G3p2 woman at 35 weeks and 4 days of gestation referred with the chief complaints of dyspnea, cough, headache, and fever. Pharyngeal swab polymerase chain reaction (PCR) was negative for COVID-19; however, in chest computed tomography (CT) angiography, ground glass was observed in the basal lobe of the left lung. The infant was born via cesarean section with gestational age of 36 weeks and an Apgar score of 8/9. No infant document was found about COVID-19‎ and other infections in several days after delivery. The patient died eight days after the onset of symptoms due to cardiovascular collapse.Conclusions: We reported the first death of postpartum maternal with COVID-19 and a healthy baby with no evidence of COVID-19 and gestational age of 36 weeks.

The nervous system of Loligo , III. Higher motor centres: the basal supraoesophageal lobes

1977 ◽  
Vol 276 (948) ◽  
pp. 351-398 ◽  
Keyword(s):  
Functional Organization ◽  
Tracking System ◽  
Efference Copy ◽  
Small Cells ◽  
Similar System ◽  
Optic Lobes ◽  
First Order ◽  
Basal Lobe ◽  
Parallel Fibres ◽  
Tracking Movements

The three main basal lobes are orientated in different planes set approximately at right angles. The components of each are similar and based on an organization reminiscent of a cerebellum, like that of the peduncle lobes. They all have large cells and fibres ventrally and numerous small cells dorsally. Each of the two parts of the anterior basal lobe contains a region with numerous very fine parallel fibres, similar to the ‘spine’ of the peduncle lobes. The dorsal basal lobes contain a similar system, but less regular. The three main parts of the basal lobe system all send fibres to the oculomotor centres of the lateral pedal lobes. The two parts of the anterior basal lobe also send fibres to the centres controlling arm movements in the anterior pedal lobe. The median basal lobe sends large tracts to the posterior pedal lobe, controlling movement of the funnel and fins. It also sends a large tract to the region of the first order giant cell, initiating the jet. There is a further massive system of descending fibres from all the basal lobes (and the precommissural lobe) sending branches to all parts of the magnocellular and palliovisceral lobes. The functional organization of the basal and peduncle lobes can be understood as follows. They all receive visual and static inputs and send large outputs to the oculomotor centre and back to the optic lobes. The oculomotor centre also receives direct inputs from the statocyst. The control of eye movements is thus organized in cephalopods in the same way as it is in vertebrates: there is a direct static input to the oculomotor centre, which also receives indirect static influences combined with visual ones, by way of the cerebellum in vertebrates, or basal and peduncle lobes in cephalopods. The basal and peduncle lobes show further similarity to the cerebellum in the presence of the numerous parallel fibres of various diameters, some very fine. These lobes receive dorsal and ventral sets of visual fibres and a set from the magnocellular lobes. The dorsal visual fibres follow the topology of the optic lobes and it is suggested that they provide a tracking system. The numerous fibres passing back from the basal lobes to the optic lobes, allow for a ‘corollary discharge’ (‘efference copy’). The ventral set of large fibres from the optic lobes to the basal lobes may serve to promote the final attack, after the smaller fibres have produced the preliminary tracking movements. The system of large fibres from the magnocellular to the basal lobes are perhaps concerned with avoiding reactions. Each of the large fibres of both of these sets gives branches to all parts of the basal lobes. All the basal lobes contain many microneurons with trunks limited to the lobes. Some of these are very short amacrines. The median basal and dorsal basal lobes contain especially numerous small cells, perhaps neurosecretory and related to reproduction by way of the optic gland, whose nerve arises nearby.

Mosquito Notes.—VI

1926 ◽  
Vol 17 (2) ◽  
pp. 101-131 ◽  
Author(s):  
F. W. Edwards
Keyword(s):  
British Museum ◽  
Basal Lobe ◽  
New Hebrides ◽  
Australasian Region

Aëdes (Stegomyia) variegatus (Dol.) is a widely-spread species in the Australasian region, and under its synonym of Stegomyia pseudoscutellaris is well-known as the carrier of filaria in Fiji and Polynesia in general. Up to the present the existence of definite local variations has not been suspected, partly because the species itself has been regarded as the Australasian representative of the Oriental A. albopictus (Skuse). Recently, however, Dr. P. A. Buxton has discovered that larvae from Samoa and the New Hebrides differ in a constant manner, and at his suggestion I have scrutinised the whole series of specimens of this species in the British Museum. This examination appears to show that there are at least five distinct varieties, distinguishable by small differences of colour and also by the male hypopygium, especially in the form of the basal lobe of the side-piece. The characters are fairly well defined, but are perhaps best treated as varietal rather than specific, especially as their significance appears to be mainly geographical.

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