Geophysical Studies of North African Cenozoic Volcanic Areas: II. Jebel Soda, Libya

1975 ◽  
Vol 12 (8) ◽  
pp. 1257-1263 ◽  
Author(s):  
J. M. Ade-Hall ◽  
P. H. Reynolds ◽  
P. Dagley ◽  
A. E. Mussett ◽  
T. P. Hubbard
Keyword(s):  
Volcanic Activity ◽  
Dipole Field ◽  
Age Dating ◽  
Data Selection ◽  
Main Concern ◽  
Data Sets ◽  
Volcanic Area ◽  
North African ◽  
African Plate ◽  
Combined Data

This study is the second of a series in which a main concern will be to try to establish the Neogene absolute motion of the African Plate. A combined paleomagnetic and K–Ar whole rock age dating study has been made of the Jebel Soda basaltic volcanic area of central Libya. Sixty basaltic flows were sampled in an area centered on 28°45′N, 15°30′E. Precisely defined paleomagnetic directions were obtained for 57 of the flows. Considerable attention has been given to the problem of data selection to obtain a best measure of the pole representing the dipole field during the period of volcanic activity. The equatorial nature of the directions, with equivalent poles extending continuously to 30°N latitude, provide a problem in data selection. Similar characteristics are apparent in the results of Schult and Soffel (1973) for the same area. A provisional average pole for the combined data sets, located at 73°N, 195°E(K: 26, A95: 5.6°) is significantly different from the geographic pole. Reasons for the 17 °divergence of paleomagnetic and geographic poles are discussed briefly.

Geophysical Studies of North African Cenozoic Volcanic Areas I: Haruj Assuad, Libya

1974 ◽  
Vol 11 (7) ◽  
pp. 998-1006 ◽  
Author(s):  
J. M. Ade-Hall ◽  
P. H. Reynolds ◽  
P. Dagley ◽  
A. E. Mussett ◽  
T. P. Hubbard ◽  
...  
Keyword(s):  
Geomagnetic Field ◽  
Age Dating ◽  
Main Concern ◽  
Volcanic Area ◽  
North African ◽  
Weighted Mean ◽  
African Plate ◽  
North Central ◽  
The North ◽  
The Difference

This study is the first of a series in which a main concern will be to establish the Neogene absolute motion of the African Plate. A combined palaeomagnetic and K–Ar whole rock age dating study has been made of the Haruj Assuad basaltic volcanic area of central Libya. Seventy volcanic units, largely pahoehoe basaltic flows, were sampled in the north-central Haruj Assuad in an area centred on 27°45′ N, 017°30′E. Precisely defined paleomagnetic directions were obtained for 68 of the volcanic units and a weighted mean pole at 83°N, 171°E (δp = 5°, δm = 9°) obtained. This pole is just significantly different at the 95% level from the geographic pole. The difference between the paleomagnetic and geographic poles is thought to be largely the result of a degree of nonrepresentative sampling of the geomagnetic field. K–Ar radiometric age data indicate that volcanic activity in the Haruj Assuad area continued at least over the interval 6.0 to 0.4 my. The polarities of dated units are in agreement with the predictions of the time polarity scale. The ages of dated flows indicate that most of the flows presently exposed are younger than 2.2 my (i.e.) Upper Pliocene and younger. A scheme for assigning relative ages to groups of flows by degree of surface weathering is now calibrated in part with absolute ages.

scholarly journals Nucleotide inhibition of the pancreatic ATP-sensitive K+ channel explored with patch-clamp fluorometry

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Samuel G Usher ◽  
Frances M Ashcroft ◽  
Michael C Puljung
Keyword(s):  
Nucleotide Binding ◽  
Inward Rectifier ◽  
K Channel ◽  
Data Sets ◽  
Channel Activity ◽  
Unknown Mechanism ◽  
Apparent Affinity ◽  
Nucleotide Inhibition ◽  
Channel Currents ◽  
Combined Data

Pancreatic ATP-sensitive K+ channels (KATP) comprise four inward rectifier subunits (Kir6.2), each associated with a sulphonylurea receptor (SUR1). ATP/ADP binding to Kir6.2 shuts KATP. Mg-nucleotide binding to SUR1 stimulates KATP. In the absence of Mg2+, SUR1 increases the apparent affinity for nucleotide inhibition at Kir6.2 by an unknown mechanism. We simultaneously measured channel currents and nucleotide binding to Kir6.2. Fits to combined data sets suggest that KATP closes with only one nucleotide molecule bound. A Kir6.2 mutation (C166S) that increases channel activity did not affect nucleotide binding, but greatly perturbed the ability of bound nucleotide to inhibit KATP. Mutations at position K205 in SUR1 affected both nucleotide affinity and the ability of bound nucleotide to inhibit KATP. This suggests a dual role for SUR1 in KATP inhibition, both in directly contributing to nucleotide binding and in stabilising the nucleotide-bound closed state.

Generic Delimitations and Relationships of the Cape Genera Capnophyllum, Dasispermum, and Sonderina, the North African Genera Krubera and Stoibrax, and a New Monotypic Genus of the Subfamily Apioideae (Apiaceae)

2009 ◽  
Vol 34 (3) ◽  
pp. 580-594 ◽  
Author(s):  
Anthony R. Magee ◽  
Ben-Erik van Wyk ◽  
Patricia M. Tilney ◽  
Stephen R. Downie
Keyword(s):  
Sequence Data ◽  
Molecular Data ◽  
Morphological Data ◽  
Data Sets ◽  
Monotypic Genus ◽  
North African ◽  
African Species ◽  
Dna Sequence Data ◽  
The North ◽  
Relationship Of

Generic circumscriptions and phylogenetic relationships of the Cape genera Capnophyllum, Dasispermum, and Sonderina are explored through parsimony and Bayesian inference analyses of nrDNA ITS and cpDNA rps16 intron sequences, morphology, and combined molecular and morphological data. The relationship of these genera with the North African genera Krubera and Stoibrax is also assessed. Analyses of both molecular data sets place Capnophyllum, Dasispermum, Sonderina, and the only southern African species of Stoibrax (S. capense) within the newly recognized Lefebvrea clade of tribe Tordylieae. Capnophyllum is strongly supported as monophyletic and is distantly related to Krubera. The monotypic genus Dasispermum and Stoibrax capense are embedded within a paraphyletic Sonderina. This complex is distantly related to the North African species of Stoibrax in tribe Apieae, in which the type species, Stoibrax dichotomum, occurs. Consequently, Dasispermum is expanded to include both Sonderina and Stoibrax capense. New combinations are formalized for Dasispermum capense, D. hispidum, D. humile, and D. tenue. An undescribed species from the Tanqua Karoo in South Africa is also closely related to Capnophyllum and the Dasispermum–Sonderina complex. The genus Scaraboides is described herein to accommodate the new species, S. manningii. This monotypic genus shares the dorsally compressed fruit and involute marginal wings with Capnophyllum, but is easily distinguished by its erect branching habit, green leaves, scabrous umbels, and fruit with indistinct median and lateral ribs, additional solitary vittae in each marginal wing, and parallel, closely spaced commissural vittae. Despite the marked fruit similarities with Capnophyllum, analyses of DNA sequence data place Scaraboides closer to the Dasispermum–Sonderina complex, with which it shares the erect habit, green (nonglaucous) leaves, and scabrous umbels.

Revision of Autolytinae (Syllidae: Polychaeta)

Zootaxa ◽  
2004 ◽  
Vol 680 (1) ◽  
pp. 1 ◽  
Author(s):  
ARNE NYGREN
Keyword(s):  
Morphological Characters ◽  
Molecular Data ◽  
Morphological Data ◽  
Data Sets ◽  
Nominal Species ◽  
Strict Consensus Tree ◽  
Incertae Sedis ◽  
Nomina Dubia ◽  
Morphological And Molecular Data ◽  
Combined Data

Autolytinae is revised based on available types, and newly collected specimens. Out of 170 nominal species, 18 are considered as incertae sedis, 43 are regarded as junior synonyms, and 25 are referred to as nomina dubia. The relationships of Autolytinae is assessed from 51 morphological characters and 211 states for 76 ingroup-taxa, and 460 molecular characters from mitochondrial 16S rDNA and nuclear 18S rDNA for 31 ingroup-taxa; outgroups include 12 non-autolytine syllid polychaetes. Two analyses are provided, one including morphological data only, and one with combined morphological and molecular data sets. The resulting strict consensus tree from the combined data is chosen for a reclassification. Three main clades are identified: Procerini trib. n., Autolytini Grube, 1850, and Epigamia gen. n. Proceraea Ehlers, 1864 and Myrianida Milne Edwards, 1845 are referred to as nomen protectum, while Scolopendra Slabber, 1781, Podonereis Blainville, 1818, Amytis Savigny, 1822, Polynice Savigny, 1822, and Nereisyllis Blainville, 1828 are considered

Addressing data comparability in the creation of combined data sets of bioapatite carbon and oxygen isotopic compositions

Archaeometry ◽  
2019 ◽  
Vol 61 (5) ◽  
pp. 1193-1206 ◽  
Author(s):  
L. A. Chesson ◽  
M. W. Kenyhercz ◽  
L. A. Regan ◽  
G. E. Berg
Keyword(s):  
Data Sets ◽  
Isotopic Compositions ◽  
Data Comparability ◽  
Oxygen Isotopic ◽  
The Creation ◽  
Combined Data

Genetic parameters for lamb birth weight in spring and autumn lambing

1998 ◽  
Vol 67 (2) ◽  
pp. 327-332 ◽  
Author(s):  
S. A. Al-Shorepy ◽  
D. R. Notter
Keyword(s):  
Birth Weight ◽  
Variance Components ◽  
Genetic Parameters ◽  
Genetic Evaluation ◽  
Residual Effects ◽  
Data Sets ◽  
Negative Effects ◽  
Common Environment ◽  
Genetic Origin ◽  
Combined Data

AbstractGenetic parameters for birth weight were estimated for two sets of spring-born and one set of autumn-born lambs of the same breed composition and genetic origin using a model that included random additive, additive maternal, permanent environmental maternal, litter and residual effects. Litter effects were significant for all data sets, indicating that within-year effects of common environment and (or) non-additive genotype were important for birth weight and should be included in genetic evaluation programmes. Estimates of variance components for autumn-born lambs differed significantly from those obtained from spring-born lambs or from the combined data. In contrast, estimates obtained for the two sets of spring-born lambs did not differ from those obtained when data on all spring-born lambs were pooled. The estimate of h2 for birth weight in spring-born lambs was over twice as large as that obtained for autumn-born lambs (0·26 v. 0·22).In contrast, the across-year repeatability of ewe effects was much larger in autumn lambs (0·41 v. 0·26) as was the full-sib littermate correlation (0·73 v. 0·49). Mean birth weights were also 0·4 to 0·6 kg less in autumn lambs. These results suggest that negative effects on birth weight that have been reported for lambs gestated during summer in equatorial and subtropical regions are also manifested (albeit at reduced levels) in less extreme climates (in this case, 37°, 15' N latitude and 654 m elevation) and that maternal variation exists in the ability of the ewe to maintain adequate lamb birth weights in autumn lambing systems.

Analysis of combined data sets yields trend estimates for vulnerable spruce-fir birds in northern United States

2015 ◽  
Vol 187 ◽  
pp. 270-278 ◽  
Author(s):  
Joel Ralston ◽  
David I. King ◽  
William V. DeLuca ◽  
Gerald J. Niemi ◽  
Michale J. Glennon ◽  
...  
Keyword(s):  
United States ◽  
Data Sets ◽  
Northern United States ◽  
Combined Data
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