Inclusion patterns in zoned garnets from Magerøy, north Norway

1984 ◽  
Vol 48 (346) ◽  
pp. 21-26 ◽  
Author(s):  
T. B. Andersen
Keyword(s):  
Rapid Growth ◽  
Outer Zone ◽  
Prograde Metamorphism ◽  
Growth Type ◽  
Compositional Zoning ◽  
Garnet Porphyroblasts ◽  
The Matrix ◽  
Quartz Grains

AbstractGarnet porphyroblasts in metasediments from Magerøy crystallized during static metamorphism. They display three optical zones, each having characteristic inclusions and chemistry. The compositional zoning is related to prograde metamorphism (an inner zone, 1, and a graphite-bearing zone) and retrogression (the outer zone, 2). Inclusions of two types are present in zone 1: type 1 are equidimensional remnants of the matrix, preferentially included along planes of rapid growth; type 2 are tubular and represent recrystallized quartz grains concentrated along defects in the garnet lattice. The defects are lineage boundaries between growth segments related to screw dislocations on crystal faces. Crystal growth developed at relatively high degrees of supersaturation, but below the supersaturation required for the development of dendrites. The inclusions suggest rapid growth of zone 1, caused by heat flow from an adjacent interkinematic mafic/ultramafic intrusive complex. The graphite-bearing zone crystallized at the metamorphic peak, while the inclusion-free idioblasfic rim probably developed during retrograde metamorphism.

COEVALNESS OF INSECT TRACE FOSSILS AND TRACE-BEARING ROCKS, A CASE STUDY FROM THE PLIO?-PLEISTOCENE OF SW SPAIN

Palaios ◽  
2021 ◽  
Vol 36 (3) ◽  
pp. 115-121
Author(s):  
EDUARDO MAYORAL ◽  
JORGE F. GENISE ◽  
FRANCISCO J. RODRÍGUEZ-TOVAR ◽  
ANA SANTOS
Keyword(s):  
Fossil Record ◽  
Field Research ◽  
Sw Spain ◽  
Modern Age ◽  
Different Types ◽  
The Matrix ◽  
Time Gap

ABSTRACT Plio?-Pleistocene outcrops located at the southwestern edge of the Guadalquivir Basin in the area of Lepe (Huelva, Spain) provide an interesting example for studying the contemporaneity of traces with the rocks that contain them. Two different types of cells compatible with the ichnogenera Celliforma (Type 1) and Palmiraichnus (Type 2) were found in these outcrops. Their walls were constructed with the same material as the matrix and our first research in the area showed no extant bees producing them suggesting that they were coeval with the trace-bearing rocks. The case of the “Palmiraichnus-like” Type 2 cells was misleading because of its similarity with Palmiraichnus described from the region in the Canary Islands and Balearic Archipelago (Spain). Two determining features were vital in clarifying this first appearance. In the Palmiraichnus-like cells we found remains of a larval cocoon in one cell that could be dated by C14, giving a modern age. In the Celliforma-like cells more field research in the area allow us to observe extant bees nesting in these rocks in autumn. Ichnological literature show a few cases of asynchronies involving extant traces found mostly in Paleozoic and Mesozoic rocks. In contrast, the case presented herein indicates the time gap between the bearing rocks and the Lepe traces was shorter (ca. 12 ky–2.6 My), enhancing the similarity of traces and rocks and thus their potential coevalness. This case may serve as a warning about other potential examples in the fossil record in which relatively short asynchronies between traces and paleosols exist.

Understanding and managing interferences in clinical laboratory assays: the role of laboratory professionals

2020 ◽  
Vol 58 (3) ◽  
pp. 350-356 ◽  
Author(s):  
Martina Zaninotto ◽  
Mario Plebani
Keyword(s):  
Patient Safety ◽  
Laboratory Testing ◽  
Clinical Laboratory ◽  
Careful Evaluation ◽  
The Matrix ◽  
Analytical Phase

AbstractThe recently raised concerns regarding biotin interference in immunoassays have increased the awareness of laboratory professionals and clinicians of the evidence that the analytical phase is still vulnerable to errors, particularly as analytical interferences may lead to erroneous results and risks for patient safety. The issue of interference in laboratory testing, which is not new, continues to be a challenge deserving the concern and interest of laboratory professionals and clinicians. Analytical interferences should be subdivided into two types on the basis of the possibility of their detection before the analytical process. The first (type 1) is represented by lipemia, hemolysis and icterus, and the second (type 2), by unusual constituents that are not undetectable before analysis, and may affect the matrix of serum/plasma of individual subjects. Type 2 cannot be identified with current techniques when performing the pre-analytical phase. Therefore, in addition to a more careful evaluation and validation of the method to be used in clinical practice, the awareness of laboratory professionals should be raised as to the importance of evaluating the quality of biological samples before analysis and to adopt algorithms and approaches in the attempt to reduce problems related to erroneous results due to specific or non-specific interferences.

Permineralized fruits and seeds from the Princeton chert (Middle Eocene) of British Columbia: Vitaceae

1990 ◽  
Vol 68 (2) ◽  
pp. 288-295 ◽  
Author(s):  
Sergio R. S. Cevallos-Ferriz ◽  
Ruth A. Stockey
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Outer Zone ◽  
Structural Features ◽  
Anatomical Structure ◽  
Thin Walled ◽  
Polyhedral Cells ◽  
A New Species

Four permineralized vitaceous seeds are described from the Middle Eocene Princeton chert, Allenby Formation, British Columbia. Three distinct types of ruminate perchalazal seeds are recognized, one is described as a new species Ampelocissus similkameenensis Cevallos-Ferriz et Stockey sp.nov., while the remaining seeds are referred to as type 1 and type 2 seeds. Five integumentary zones are recognized in each seed: zone 1 is an outer zone of thin-walled rectangular to polyhedral cells; zone 2 is a zone of thick-walled sclereids; zone 3 is a zone of cells with spiral thickenings; zone 4 is a zone of rectangular thin-walled cells (when preserved); and zone 5 is a zone of tangentially elongated thin-walled cells with dark contents. The chalaza in seeds of A. similkameenensis and the type 1 seed has three distinct zones, while in the type 2 seed it contains cells similar to integumentary zone 2. These Princeton seeds illustrate that structural features of Eocene Vitaceae include characters unlike those of extant taxa. This information contributes to our knowledge of anatomical structure within the group as a whole and underscores the need for review of both fossil and extant Vitaceae. Paucity of vitaceous seeds in the Princeton chert compared to the large number of preserved aquatic and semiaquatic remains suggests that they represent plants that grew in a nearby environment. Abrasion of the integument suggests that like extant seeds, they may have been dropped after passing through the gut of a bird.

scholarly journals Two-level inhibition of galK expression by Spot 42: Degradation of mRNA mK2 and enhanced transcription termination before the galK gene

2015 ◽  
Vol 112 (24) ◽  
pp. 7581-7586 ◽  
Author(s):  
Xun Wang ◽  
Sang Chun Ji ◽  
Heung Jin Jeon ◽  
Yonho Lee ◽  
Heon M. Lim
Keyword(s):  
Binding Site ◽  
Molecular Mechanisms ◽  
Transition Period ◽  
Transcription Termination ◽  
Growth Type ◽  
Down Regulation ◽  
Type Switch ◽  
Specific Mrna

The Escherichia coli gal operon has the structure Pgal-galE-galT-galK-galM. During early log growth, a gradient in gene expression, named type 2 polarity, is established, as follows: galE > galT > galK > galM. However, during late-log growth, type 1 polarity is established in which galK is greater than galT, as follows: galE > galK > galT > galM. We found that type 2 polarity occurs as a result of the down-regulation of galK, which is caused by two different molecular mechanisms: Spot 42-mediated degradation of the galK-specific mRNA, mK2, and Spot 42-mediated Rho-dependent transcription termination at the end of galT. Because the concentration of Spot 42 drops during the transition period of the polarity type switch, these results demonstrate that type 1 polarity is the result of alleviation of Spot 42-mediated galK down-regulation. Because the Spot 42-binding site overlaps with a putative Rho-binding site, a molecular mechanism is proposed to explain how Spot 42, possibly with Hfq, enhances Rho-mediated transcription termination at the end of galT.

Non-marine oolitic ironstones in the Lower Cretaceous Wealden sediments of southeast England

1992 ◽  
Vol 129 (3) ◽  
pp. 349-358 ◽  
Author(s):  
Kevin G. Taylor
Keyword(s):  
Iron Oxide ◽  
Lower Cretaceous ◽  
Type I ◽  
Soil Material ◽  
Dominant Mechanism ◽  
Lake Chad ◽  
Local Soil ◽  
Quartz Grains

AbstractOolitic ironstones are described from the early Cretaceous non-marine Wealden sediments of southeast England. The recognition of non-marine oolitic ironstones in the geological record is rare and, therefore, warrants further study. The oolitic ironstones described take two forms, named here type-I and type-2 ironstones.Type-1 ironstones contain pisoids and ooids of berthierine together with sandstone fragments and detrital quartz grains. The pisoids (up to 0.5 cm in size) vary from subspherical to highly irregular. The smaller ooids (up to 1 mm in size) are generally ellipsoidal but strongly asymmetrical forms are also present. The form of these pisoids and ooids suggest that mechanical accretion was not the dominant mechanism controlling their formation. It is proposed that this ironstone type formed from the reworking and redeposition of local soil material.Type-2 ironstones, of which only one unequivocal example has been studied, is composed of iron oxide ooids set in a detrital matrix. The ooids are most commonly regularly ellipsoidal and exhibit a decrease in iron at their centres. It is proposed here that the ooids suffered post-depositional iron depletion at their centres, in a similar fashion to that proposed for the recent Lake Chad oolites. There is no unequivocal evidence as to the origin of the ooids.This study is important in that it shows that different ironstones can be formed by different processes essentially within the same environment. Comparison of non-marine oolitic ironstones with the better-developed marine examples should prove a valuable exercise.

Regulation of sweetpotato growth and differentiation by glutamate dehydrogenase

1997 ◽  
Vol 75 (7) ◽  
pp. 1070-1078 ◽  
Author(s):  
G. O. Osuji ◽  
W. C. Madu
Keyword(s):  
Glutamate Dehydrogenase ◽  
Growth Retardation ◽  
Ipomoea Batatas ◽  
Normal Growth ◽  
Naphthaleneacetic Acid ◽  
Growth Type ◽  
Combined Supplementation ◽  
Type 3

The function of glutamate dehydrogenase was studied in cultured sweetpotato (Ipomoea batatas) nodal explants. The glutamate dehydrogenase was fractionated to charge isomers. Supplementation of the growth medium with either naphthaleneacetic acid or benzyladenine in the presence of 20 mM NH4NO3 induced normal growth (type 1 sweetpotato). The basic and acidic charge isomers of glutamate dehydrogenase were not suppressed. Combined supplementation with 70 mM NH4+ and either 1 mg ∙ L−1 benzyladenine or 0.1 mg ∙ L−1 naphthaleneacetic acid caused growth retardation (type 2 sweetpotato) and the suppression of the basic charge isomers. Combined supplementation with 45 mM NH4+ and either 1 mg ∙ L−1 benzyladenine or 0.1 mg ∙ L−1 naphthaleneacetic acid induced normal growth (type 3 sweetpotato), but the acidic charge isomers were suppressed. Combined supplementation with benzyladenine and naphthaleneacetic acid suppressed all the charge isomers and abolished amination by the enzyme, thereby causing severe growth retardation. The type 1 and type 3 sweetpotato glutamate dehydrogenases were more aminating (Michaelis constant Km = 12.5 and 14.8 mM NH4Cl, respectively) than type 2 sweetpotato glutamate dehydrogenase (Km = 82.6 mM NH4Cl). The differential growth retardations which accompanied the three phases of the suppression of the aminating charge isomers are evidence that the enzyme is aminating in vivo and that it employed that activity in the regulation of sweetpotato growth and differentiation. Key words: glutamate dehydrogenase, amination depression, sweetpotato retardation.

Recurrence of ICA-PCoA aneurysms after neck clipping

1994 ◽  
Vol 80 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Toshisuke Sakaki ◽  
Toshikazu Takeshima ◽  
Masao Tominaga ◽  
Hiroshi Hashimoto ◽  
Shoichiro Kawaguchi
Keyword(s):  
Internal Carotid ◽  
Distal Portion ◽  
Point Of View ◽  
Surrounding Tissue ◽  
Growth Type ◽  
Content Type ◽  
Aneurysmal Neck ◽  
Medical University

✓ Between 1975 and 1992, 2211 patients underwent aneurysmal neck clipping at the Nara Medical University clinic and associated hospitals. The aneurysm in 931 of these patients was situated at the junction of the internal carotid artery (ICA) and posterior communicating artery (PCoA). Seven patients were readmitted 4 to 17 years after the first surgery because of regrowth and rupture of an ICA-PCoA aneurysmal sac that had arisen from the residual neck. On angiograms obtained following aneurysmal neck clipping, a large primitive type of PCoA was demonstrated in six patients and a small PCoA in one. A small residual aneurysm was confirmed in only two patients and angiographically complete neck clipping in five. Recurrent ICA-PCoA aneurysms were separated into two types based on the position of the old clip in relation to the new growth. Type 1 aneurysms regrow from the entire neck and balloon eccentrically. In this type, it is possible to apply the clip at the neck as in conventional clipping for a ruptured aneurysm. Type 2 includes aneurysms in which the proximal portion of a previous clip is situated at the corner of the ICA and aneurysmal neck and the distal portion on the enlarged dome of the aneurysm, because the sac is regrowing from a portion of the residual neck. In this type of aneurysm, a Sugita fenestrated clip can occlude the residual neck, overriding the old clip. Classifying these aneurysms into two groups is very useful from a surgical point of view because it is possible to apply a new clip without removing the old clip, which was found to be adherent to surrounding tissue.

scholarly journals Комбинационное рассеяние света в кристаллах AlN, выращенных методом сублимации на затравках SiC и AlN

2019 ◽  
Vol 53 (11) ◽  
pp. 1593
Author(s):  
И.Д. Бреев ◽  
А.Н. Анисимов ◽  
А.А. Вольфсон ◽  
О.П. Казарова ◽  
Е.Н. Мохов
Keyword(s):  
Structural Quality ◽  
Seed Type ◽  
Growth Type ◽  
Total Evaporation ◽  
Scattering Technique ◽  
Type 3 ◽  
Mechanism Of Growth

AbstractThe Raman-scattering technique is used to analyze the structural quality of bulk AlN crystals grown by sublimation on SiC and AlN seeds. Growth on SiC seeds is conducted with retention of the SiC seed during growth (type 1) and with total evaporation of the SiC seed (type 2). Growth on AlN seeds is conducted in tungsten containers with no graphite parts (type 3). According to the analysis of Raman spectra, the highest quality is inherent in type-3 crystals that exhibit minimal full widths at half maximum of Raman lines. The experimentally observed specific features are defined by differences in the mechanism of growth and by the content of dopant impurities in the crystals grown.

Crystalloid Inclusions in Hepatocyte Mitochondria and Their Similarity to Cytoplasmic Crystalloids

1974 ◽  
Vol 32 ◽  
pp. 198-199
Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo
Keyword(s):  
Liver Disease ◽  
Alcoholic Liver Disease ◽  
Special Interest ◽  
Structural Variations ◽  
Mitochondrial Alterations ◽  
The Matrix ◽  
Crystalloid Inclusions ◽  
Liver Biopsies

Mitochondrial alterations were studied in 25 liver biopsies from patients with alcoholic liver disease. Of special interest were the morphologic resemblance of certain fine structural variations in mitochondria and crystalloid inclusions. Four types of alterations within mitochondria were found that seemed to relate to cytoplasmic crystalloids.Type 1 alteration consisted of localized groups of cristae, usually oriented in the long direction of the organelle (Fig. 1A). In this plane they appeared serrated at the periphery with blind endings in the matrix. Other sections revealed a system of equally-spaced diagonal lines lengthwise in the mitochondrion with cristae protruding from both ends (Fig. 1B). Profiles of this inclusion were not unlike tangential cuts of a crystalloid structure frequently seen in enlarged mitochondria described below.

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