scholarly journals An Ediacaran opportunist? Characteristics of a juvenile Dickinsonia costata population from Crisp Gorge, South Australia

2018 ◽  
Vol 92 (3) ◽  
pp. 313-322 ◽  
Author(s):  
Lily M. Reid ◽  
Diego C. García-Bellido ◽  
James G. Gehling
Keyword(s):  
Size Range ◽  
Large Population ◽  
South Australia ◽  
Morphological Characters ◽  
Juvenile Form ◽  
Flinders Ranges ◽  
Gradual Loss ◽  
Loss Of Mass ◽  
Phylogenetic Affinities ◽  
The Relationship

AbstractDespite 70 years of study, Dickinsonia remains one of the Ediacara biota’s most enigmatic taxa with both morphological characters and phylogenetic affinities still debated. A large population of relatively small Dickinsonia costata present on a semi-contiguous surface from the Crisp Gorge fossil locality in the Flinders Ranges (South Australia) provides an opportunity to investigate this taxon in its juvenile form. This population supports earlier findings that suggest D. costata’s early growth was isometric, based on the relationship between measured variables of length and width. The number of body units increases with length, but at a decreasing rate. A correlation between a previously described physical feature, present as a shrinkage rim partially surrounding some specimens and a novel, raised lip in some specimens, suggests that both features may have been the result of a physical contraction in response to the burial process, rather than due to a gradual loss of mass during early diagenesis. A marked protuberance in 15% of the population is also noted in limited specimens within the South Australian Museum collections and appears to be present only in juvenile D. costata. Both the abundance and narrow size range of this population support the notion that Dickinsonia was a hardy opportunist, capable of rapid establishment and growth on relatively immature textured organic-mat substrates.

THE RELATIONSHIP BETWEEN ENDOSPERM DEVELOPMENT AND MORPHOLOGIC CHARACTERS IN THE F2 GENERATION OF A T. DICOCCUM × T. VULGARE CROSS

1931 ◽  
Vol 5 (2) ◽  
pp. 208-218 ◽  
Author(s):  
J. B. Harrington
Keyword(s):  
Random Sample ◽  
Large Population ◽  
Morphological Characters ◽  
Endosperm Development ◽  
Class A ◽  
Class B ◽  
Class C ◽  
F2 Generation ◽  
The Individual ◽  
The Relationship

The relationship between the degree of plumpness of F2 seeds and the type of the resulting F2 plants was studied in the cross Vernal (T. dicoccum) × Marquis (T. vulgare). A random sample of F2 seeds was divided into three classes based upon kernel plumpness, viz. plump (Class A), slightly shrunken (Class B), and shrunken (Class C). In these there were by number 55.5, 41.0 and 3.5% of seeds respectively. Emergence of F2 plants in the field was 64, 58 and 36% for Classes A, B and C. The F2 plants were studied for 13 morphological characters. Comparing the populations for all characters combined, Class A was more dicoccum-like than Class B, and Class B much more dicoccum-like than Class C. The proportion of vulgare-like character was 16, 20 and 32% for Classes A, B and C, respectively. Considering the character of the individual plants, the ratios of dicoccum-like to vulgare-like were 12.1:1, 5.3:1, and 2.2:1 for classes A, B and C, respectively. Furthermore, the vulgare-like plants of classes A and B were less vulgare-like than those of Class C. There were present, however, in Classes A and B some plants that were fully as vulgare-like as any in Class C. These results indicate that, in an interspecific wheat cross, the breeder should give special attention to the shrunken F2 seeds if he has very limited nursery space and a large amount of seed; whereas if he has plenty of space for a large population, special care of shrunken F2 seeds does not seem warranted.

scholarly journals Phyllozoon and Aulozoon: key components of a novel Ediacaran death assemblage in Bathtub Gorge, Heysen Range, South Australia

2021 ◽  
pp. 1-14
Author(s):  
James G. Gehling ◽  
Bruce Runnegar
Keyword(s):  
South Australia ◽  
Taxonomic Status ◽  
Widespread Species ◽  
Flinders Ranges ◽  
Small Window ◽  
Storm Wave ◽  
Tubular Body ◽  
Phylogenetic Affinities ◽  
Body Fossil

Abstract The recognition of fossiliferous horizons both below and above the classical Ediacara levels of the Flinders Ranges, South Australia, significantly expands the potential of this candidate World Heritage succession. Here we document a small window into the biology and taphonomy of the late Ediacaran seafloor within the new Nilpena Sandstone Member of the Rawnsley Quartzite in Bathtub Gorge, northern Heysen Range. A 1 m2 slab extracted from the gorge, now on permanent display at the South Australian Museum, has a death assemblage dominated by the erniettomorph Phyllozoon hanseni Jenkins and Gehling 1978 and a newly named macroscopic tubular body fossil – Aulozoon soliorum gen. et sp. nov. – on its fine sandstone bed sole. The orientations and juxtaposition of these taxa suggest overprinting of an in situ benthic Phyllozoon community by sand-filled tubes of Aulozoon carried in by a storm wave-base surge. Phyllozoon hanseni is a widespread species that is restricted to the Nilpena Sandstone Member of the Rawnsley Quartzite, whereas Dickinsonia costata ranges from the underlying Ediacara Sandstone Member into the Nilpena Sandstone Member. Fundamental differences in the ways these two vendobiont taxa are constructed and preserved may provide insights into their biology and phylogenetic affinities. In the Nilpena Sandstone Member, D. costata is joined by Dickinsonia rex Jenkins 1992, which appears to be confined to the member, and is here re-described to clarify its taxonomic status and stratigraphic distribution.

scholarly journals Pituitary MRI characteristics in 297 acromegaly patients based on T2-weighted sequences

2015 ◽  
Vol 22 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Iulia Potorac ◽  
Patrick Petrossians ◽  
Adrian F Daly ◽  
Franck Schillo ◽  
Claude Ben Slama ◽  
...  
Keyword(s):  
Large Population ◽  
Optic Chiasm ◽  
Research Priority ◽  
Maximal Diameter ◽  
Magnetic Resonance Imaging Mri ◽  
Multimodal Management ◽  
Mri Characteristics ◽  
Weighted Sequences ◽  
The Relationship

Responses of GH-secreting adenomas to multimodal management of acromegaly vary widely between patients. Understanding the behavioral patterns of GH-secreting adenomas by identifying factors predictive of their evolution is a research priority. The aim of this study was to clarify the relationship between the T2-weighted adenoma signal on diagnostic magnetic resonance imaging (MRI) in acromegaly and clinical and biological features at diagnosis. An international, multicenter, retrospective analysis was performed using a large population of 297 acromegalic patients recently diagnosed with available diagnostic MRI evaluations. The study was conducted at ten endocrine tertiary referral centers. Clinical and biochemical characteristics, and MRI signal findings were evaluated. T2-hypointense adenomas represented 52.9% of the series, were smaller than their T2-hyperintense and isointense counterparts (P<0.0001), were associated with higher IGF1 levels (P=0.0001), invaded the cavernous sinus less frequently (P=0.0002), and rarely caused optic chiasm compression (P<0.0001). Acromegalic men tended to be younger at diagnosis than women (P=0.067) and presented higher IGF1 values (P=0.01). Although in total, adenomas had a predominantly inferior extension in 45.8% of cases, in men this was more frequent (P<0.0001), whereas in women optic chiasm compression of macroadenomas occurred more often (P=0.0067). Most adenomas (45.1%) measured between 11 and 20 mm in maximal diameter and bigger adenomas were diagnosed at younger ages (P=0.0001). The T2-weighted signal differentiates GH-secreting adenomas into subgroups with particular behaviors. This raises the question of whether the T2-weighted signal could represent a factor in the classification of acromegalic patients in future studies.

scholarly journals The Relationship Between TSH and Free T4 in a Large Population Is Complex and Nonlinear and Differs by Age and Sex

2013 ◽  
Vol 98 (7) ◽  
pp. 2936-2943 ◽  
Author(s):  
Narelle C. Hadlow ◽  
Karen M. Rothacker ◽  
Robert Wardrop ◽  
Suzanne J. Brown ◽  
Ee Mun Lim ◽  
...  
Keyword(s):  
Large Population ◽  
Free T4 ◽  
The Relationship ◽  
Age And Sex

scholarly journals The relationship between apathy and impulsivity in large population samples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pierre Petitet ◽  
Jacqueline Scholl ◽  
Bahaaeddin Attaallah ◽  
Daniel Drew ◽  
Sanjay Manohar ◽  
...  
Keyword(s):  
Young Adults ◽  
Large Population ◽  
Assessment Tools ◽  
Self Assessment ◽  
Social And Emotional ◽  
Scale Scores ◽  
Recent Addition ◽  
The Relationship ◽  
Gathering Data ◽  
Neuropsychiatric Conditions

AbstractApathy and impulsivity are debilitating conditions associated with many neuropsychiatric conditions, and expressed to variable degrees in healthy people. While some theories suggest that they lie at different ends of a continuum, others suggest their possible co-existence. Surprisingly little is known, however, about their empirical association in the general population. Here, gathering data from six large studies ($$n = 3755$$ n = 3755 ), we investigated the relationship between measures of apathy and impulsivity in young adults. The questionnaires included commonly used self-assessment tools—Apathy Evaluation Scale, Barratt Impulsiveness Scale (BIS-11) and UPPS-P Scale—as well as a more recent addition, the Apathy Motivation Index (AMI). Remarkably, across datasets and assessment tools, global measures of apathy and impulsivity correlated positively. However, analysis of sub-scale scores revealed a more complex relationship. Although most dimensions correlated positively with one another, there were two important exceptions revealed using the AMI scale. Social apathy was mostly negatively correlated with impulsive behaviour, and emotional apathy was orthogonal to all other sub-domains. These results suggest that at a global level, apathy and impulsivity do not exist at distinct ends of a continuum. Instead, paradoxically, they most often co-exist in young adults. Processes underlying social and emotional apathy, however, appear to be different and dissociable from behavioural apathy and impulsivity.

A magnitude scale for local earthquakes in South Australia

1975 ◽  
Vol 65 (5) ◽  
pp. 1267-1285
Author(s):  
Ian C. F. Stewart
Keyword(s):  
Epicentral Distance ◽  
South Australia ◽  
Magnitude Scale ◽  
Source Spectrum ◽  
S Waves ◽  
Scale Parameters ◽  
Local Earthquakes ◽  
Dependent Absorption ◽  
Relationship Of ◽  
The Relationship

Abstract To minimize dispersion in local magnitude estimates due to different instrumental bandwidths, a scale has been established to allow for the average source spectrum, geometrical attenuation, and frequency-dependent absorption. The data used to derive the scale parameters were from S waves recorded in South Australia from 1967 through 1970, in the frequency range 1 to 10 Hz, and for epicentral distances up to 5°. The magnitudes were mainly in the range 1.5 to 3.5. The local scale MN is given by M N = 4.85 + log A g + 0.84 log Δ + 0.0003 f Δ / 2.3 − 2.89 log f + 2.45 ( log f ) 2 + c where Ag mm is the ground amplitude at f Hz at Δ km epicentral distance, and c is a station correction. The dispersion in observations of magnitude has probably been reduced by use of the scale to near the theoretical limits, allowing for possible source radiation patterns. The relationship of the scale to other measures of magnitude is uncertain, but MN may be approximately equivalent to the local Richter magnitude ML for the magnitude range (1.5 &lt; ML &lt; 3.5) commonly observed in South Australia. The scle is limited in use to data in the ranges given above, for local earthquakes in South Australia. Modification is necessary before such a magnitude scale can be applied elsewhere or to different data ranges.

Entomophilic nematodes, Diploscapter coronatus and Oscheius tipulae from Afghanistan

Zootaxa ◽  
2021 ◽  
Vol 4926 (3) ◽  
pp. 401-416
Author(s):  
MOHAMMAD HUSSAIN FALAHZADAH ◽  
EBRAHIM SHOKOOHI ◽  
GHOLAM HOSSEIN MORAVEJ ◽  
PHATU WILLIAM MASHELA ◽  
ABDUL KHALID MADADI ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Genetic Distance ◽  
Galleria Mellonella ◽  
Morphological Characters ◽  
Molecular Data ◽  
Soil Samples ◽  
The Body ◽  
Morphometric Data ◽  
Molecular Approaches ◽  
The Relationship

Several soil samples from different habitats in Badakhshan province of Afghanistan were collected to isolate and characterize bacteria feeding nematodes. The Galleria mellonella-baiting method was used for the isolation of the Afghan insect-associated nematodes. The nematodes were studied using morphological and morphometric data. The Oscheius specimen was characterized by a longer body (630–820 µm) and shorter pharynx (125–145 µm), whereas other morphological characters were not unusual. The Diploscapter specimen had an annulated cuticle, with lip region width 1.5 times shorter than the stoma, and had separated pharyngeal corpus from the isthmus and vulva located in the middle of the body. The molecular data were derived using three loci; 18S, 28S (D2/D3 segment), and ITS rRNA region, which were utilized to measure the genetic distance. The phylogenetic analysis was conducted to reconstruct the relationship tree. Both morphological and molecular approaches confirmed the identity of nematode isolates as Oscheius tipulae and Diploscapter coronatus. This is the first report of insect-associated nematodes from the soil of Afghanistan. Both species were capable of infecting and killing G. mellonella larvae in less than 96 h. 

The Dawson Hill Member of the Grindstone Range Sandstone in the Flinders Ranges, South Australia

2010 ◽  
Vol 134 (1) ◽  
pp. 115-124 ◽  
Author(s):  
J.B. Jago ◽  
C.G. Gatehouse ◽  
C.McA. Powell ◽  
T. Casey ◽  
E.M. Alexander
Keyword(s):  
South Australia ◽  
Flinders Ranges
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