scholarly journals Crystal aggregates record the pre-eruptive flow field in the volcanic conduit at Kīlauea, Hawaii

2020 ◽  
Vol 6 (49) ◽  
pp. eabd4850
Author(s):  
Michelle DiBenedetto ◽  
Zhipeng Qin ◽  
Jenny Suckale
Keyword(s):  
Flow Field ◽  
Direct Evidence ◽  
Aggregate Formation ◽  
Flow Mechanism ◽  
Common Occurrence ◽  
Physical Processes ◽  
Conduit Flow ◽  
Steady Wave ◽  
Volcanic Conduit ◽  
The Common

Developing reliable, quantitative conduit models that capture the physical processes governing eruptions is hindered by our inability to observe conduit flow directly. The closest we get to direct evidence is testimony imprinted on individual crystals or bubbles in the conduit and preserved by quenching during the eruption. For example, small crystal aggregates in products of the 1959 eruption of Kīlauea Iki, Hawaii contain overgrown olivines separated by large, hydrodynamically unfavorable angles. The common occurrence of these aggregates calls for a flow mechanism that creates this crystal misorientation. Here, we show that the observed aggregates are the result of exposure to a steady wave field in the conduit through a customized, process-based model at the scale of individual crystals. We use this model to infer quantitative attributes of the flow at the time of aggregate formation; notably, the formation of misoriented aggregates is only reproduced in bidirectional, not unidirectional, conduit flow.

Glycoproteins IIb and IIIa and Platelet Thrombospondin in a Liposome Model of Platelet Aggregation

1986 ◽  
Vol 55 (02) ◽  
pp. 240-245 ◽  
Author(s):  
M E Rybak
Keyword(s):  
Platelet Aggregation ◽  
Direct Evidence ◽  
Phospholipid Vesicles ◽  
Aggregate Formation ◽  
Membrane Glycoproteins ◽  
Protein Orientation ◽  
Phosphatidylcholine Liposomes ◽  
Calcium Dependent ◽  
Lentil Lectin ◽  
Complete Reversal

SummaryPlatelet membrane glycoproteins IIb and IIIa and platelet thrombospondin were incorporated onto phosphatidylcholine liposomes, by freeze thawing and sonication. Protein orientation on the liposomes was confirmed by susceptibility to neuraminidase cleavage and binding to lentil lectin-Sepharose (GPIIb-IIIa liposomes) and to heparin-Sepharose (thrombospondin liposomes). Glycoproteins Ilb-IIIa bound 125I-fibrinogen with Kd of 7.5 × 10™7M. Binding was reversible and calcium-dependent. Ilb-IIIa liposomes underwent fibrinogen-dependent aggregation in the presence of 10 mM CaCl2. Maximal aggregate formation was observed with a combination of IIb-IIIa liposomes and thrombospondin liposomes. This aggregation was partially inhibited by preincubation with monoclonal antibodies to the IIb-IIIa complex. Addition of EDTA caused complete reversal of aggregates. Thrombospondin liposomes also underwent fibrinogen and calcium dependent aggregation, however, this aggregation was less than that observed with the GPIIb-IIIa liposomes. Maximal aggregate formation was observed with a mixture of IIb-IIIa liposomes and thrombospondin liposomes. These studies demonstrate that GPIIb-IIIa and thrombospondin can be incorporated into phospholipid vesicles with preservation of function. Direct evidence is provided to demonstrate that glycoprotein lib and Ilia and fibrinogen are sufficient for platelet aggregation and to demonstrate that thrombospondin may also contribute to platelet aggregation.

scholarly journals Subtype Characterization and Zoonotic Potential of Cryptosporidium felis in Cats in Guangdong and Shanghai, China

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 89
Author(s):  
Jiayu Li ◽  
Fuxian Yang ◽  
Ruobing Liang ◽  
Sheng Guo ◽  
Yaqiong Guo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Phylogenetic Analysis ◽  
Genetic Characterization ◽  
Zoonotic Potential ◽  
Common Occurrence ◽  
High Genetic Diversity ◽  
Gp60 Gene ◽  
The Common ◽  
Subtyping Tool

Cryptosporidiumfelis is an important cause of feline and human cryptosporidiosis. However, the transmission of this pathogen between humans and cats remains controversial, partially due to a lack of genetic characterization of isolates from cats. The present study was conducted to examine the genetic diversity of C. felis in cats in China and to assess their potential zoonotic transmission. A newly developed subtyping tool based on a sequence analysis of the 60-kDa glycoprotein (gp60) gene was employed to identify the subtypes of 30 cat-derived C. felis isolates from Guangdong and Shanghai. Altogether, 20 C. felis isolates were successfully subtyped. The results of the sequence alignment showed a high genetic diversity, with 13 novel subtypes and 2 known subtypes of the XIXa subtype family being identified. The known subtypes were previously detected in humans, while some of the subtypes formed well-supported subclusters with human-derived subtypes from other countries in a phylogenetic analysis of the gp60 sequences. The results of this study confirmed the high genetic diversity of the XIXa subtype family of C. felis. The common occurrence of this subtype family in both humans and cats suggests that there could be cross-species transmission of C. felis.

Flow structure segmentation for vortex identification using butterfly convolutional neural networks

2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040121 ◽  
Author(s):  
Zhi-Xian Ye ◽  
Qian Chen ◽  
Bing-Hua Li ◽  
Jian-Feng Zou ◽  
Yao Zheng
Keyword(s):  
Flow Field ◽  
Physical Mechanism ◽  
Image Data ◽  
Global Information ◽  
Vortex Identification ◽  
Feature Maps ◽  
Gradient Tensor ◽  
The Common ◽  
Original Size ◽  
Identification Techniques

Vortex identification is important for understanding the physical mechanism of turbulent flow. The common vortex identification techniques based on velocity gradient tensor such as [Formula: see text] criterion will consume a lot of computing resources for processing great quantity of experimental data. To improve the vortex identification efficiency and achieve real-time recognition, we present a novel vortex identification method using segmentation with convolutional neural network (CNN) based on flow field image data, which is named “Butterfly-CNN”. Considering that the view of flow field is small, it is necessary to integrate both the local and global feature maps to achieve higher precision. The architecture consists of an encoded–decoded path, which is similar to [Formula: see text]-net but with different superimposed network part. In the Butterfly-CNN, the cross-expanding paths are designed with the global information to enable precise localization, and the feature maps after each convolution are regarded as the original pictures, then convolute to the size of the last feature map and upsample to the original size again. Finally, the decoded and cross-expanding networks are added up. The Butterfly-CNN can be trained end-to-end from a few images, and it is useful and efficient for vortex identification.

The risk of aspiration in Dettol poisoning: a retrospective cohort study

1995 ◽  
Vol 14 (2) ◽  
pp. 190-191 ◽  
Author(s):  
Thomas Y.K. Chan ◽  
Julian A.J.H. Critchley ◽  
Joseph T.F. Lau
Keyword(s):  
Retrospective Cohort ◽  
Matched Control ◽  
Gastric Lavage ◽  
Common Occurrence ◽  
Pine Oil ◽  
Control Subjects ◽  
Increased Risk ◽  
The Common ◽  
Risk Of Aspiration ◽  
Increase In Risk

1 To determine if the risk of aspiration is increased in 'Dettol' (4.8% chloroxylenol, pine oil and isopropyl alco hol) poisoning and the factors that may be responsible, a study was made of 89 patients and 89 matched control subjects with other forms of poisoning admitted to the Prince of Wales Hospital, Hong Kong. 2 Aspiration was more common in patients with Dettol poisoning (8% vs 3%, P = 0.16). There were more control subjects with drowsiness at presentation (54% vs 24%, P < 0.0001), but the use of gastric lavage (88% vs 64%, P < 0.001) and the occurrence of vomiting (62% vs 17%, P < 0.0001) were more common in patients with Dettol poisoning. 3 Our findings suggest that Dettol poisoning may be asso ciated with an increased risk of aspiration. This increase in risk may be related to the use of gastric lavage and the common occurrence of vomiting in patients with Dettol poisoning.

DYNAMICS OF A2 FINGER PULLEY RUPTURE

2007 ◽  
Vol 07 (01) ◽  
pp. 75-87 ◽  
Author(s):  
MING A. TAN ◽  
FRANZ K. FUSS ◽  
GÜNTHER NIEGL
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Initial Rate ◽  
Constant Force ◽  
Common Occurrence ◽  
Pulley System ◽  
Convergence Test ◽  
A2 Pulley ◽  
The Common ◽  
Rupture Mechanism

A mathematical model of the A2 pulley system will enable us to have a better understanding of the mechanics of the pulley-tendon system and provide us with insights of the pulley rupture mechanism. The A2 pulley was modeled based on parallel pulley fibers attached to a phalanx with a tendon passing them. Mechanical properties of the pulleys such as stiffness, strength and friction were included in the model. A convergence test was done to ensure the accuracy of the test. The model managed to show high loads on flexed finger may lead to pulley ruptures. Further studies on the rupture mechanism showed that pulley ruptures are self-propagating when a constant force is applied and the rate of rupture increases, as fewer intact fibers are present to support the load. The initial rate of propagation is much slower and this accelerates as more fibers are ruptured. This explains the common occurrence of partial pulley ruptures.

scholarly journals Level of carbon dioxide diffuse degassing from the ground of Vesuvio: comparison between extensive surveys and inferences on the gas source

2013 ◽  
Vol 56 (4) ◽  
Author(s):  
Domenico Granieri ◽  
Maria Luisa Carapezza ◽  
Rosario Avino ◽  
Stefano Caliro ◽  
Carlo Cardellini ◽  
...  
Keyword(s):  
Emission Pattern ◽  
Diffuse Degassing ◽  
Summit Area ◽  
Gas Source ◽  
A Value ◽  
Volcanic Conduit ◽  
The Common ◽  
Soil Flux ◽  
Different Sources ◽  
Tectonic Line

<p>An extensive campaign of diffuse CO<span><sub>2</sub></span> soil flux was carried out at the cone of Vesuvio in October 2006 with two main objectives: 1) to provide an estimation of CO<span><sub>2</sub></span> diffusely discharged through the soils in the summit area and 2) to evidence those sectors of the volcano where structural and morphological conditions could favour the gas output. The survey consisted of 502 measurements of soil CO<span><sub>2</sub></span> flux homogenously distributed over an area of about 1.8 km<span><sup>2</sup></span>. Results of this survey were compared with those obtained during a similar campaign carried out by Frondini et al. in 2000, from which we have taken and reinterpreted a subset of data belonging to the common investigated area. Graphical statistical analysis showed three overlapping populations in both surveys, evidencing the contribution of three different sources feeding the soil CO<span><sub>2</sub></span> degassing process. The overall CO<span><sub>2</sub></span> emission pattern of 2006 is coherent with that observed in 2000 and suggests that a value between 120 and 140 t/day of CO<span><sub>2</sub></span> is representative of the total CO<span><sub>2</sub></span> discharged by diffuse degassing from the summit area of Vesuvio. The preferential exhaling area lies in the inner crater, whose contribution resulted in 45.3% of the total CO<span><sub>2</sub></span> emission in 2006 (with 62.8 t/day) and in 57.4% (with 70.3 t/day) in 2000, although its extension is only 13% of the investigated area. This highly emissive area correlated closely with the structural discontinuities of Vesuvio cone, mainly suggesting that the NW-SE trending tectonic line is actually an active fault leaking deep gas to the bottom of the crater. The drainage action of the fault could be enhanced by the “aspiration” effect of the volcanic conduit.</p>

Burns first aid

2019 ◽  
pp. 59-66
Author(s):  
Jorge Leon-Villapolas
Keyword(s):  
Operative Management ◽  
First Aid ◽  
Burn Injuries ◽  
Tissue Preservation ◽  
Common Occurrence ◽  
Conflicting Information ◽  
History Of ◽  
The Common ◽  
The Uk ◽  
The Way

In the UK alone there are approximately 175,000 acute burn injuries /year. There is a great variation in the way these injuries are managed. Advances in our understanding of the pathophysiology and natural history of burn injuries have highlighted the importance of early intervention in minimizing later functional and cosmetic morbidity. Differences in beliefs and ethnic background have a large impact on the way that burns are initially dealt with, as we know that only a minority of patients presenting with burns are optimally managed pre-hospital. Lack of education and conflicting information about burns first aid is believed to be a major factor in the common occurrence of burnt patients presenting with a variety of domestic remedies being applied to their burns as first aid. Judicious application of simple burns first aid is the first step for soft tissue preservation, improvement of outcomes and a decrease in the need for operative management.

scholarly journals Naticid gastropod and octopodid cephalopod predatory traces: evidence of drill holes on the leucosid crab Ristoria pliocaenica (Ristori, 1891), from the Pliocene of the “La Serra” quarry (Tuscany, Italy)

10.4081/19 ◽  
2012 ◽  
Vol 153 (2) ◽  
pp. 257 ◽  
Author(s):  
Giovanni Pasini ◽  
Alessandro Garassino
Keyword(s):  
Fossil Record ◽  
Direct Evidence ◽  
Central Italy ◽  
Decapod Crustaceans ◽  
Early Pliocene ◽  
First Report ◽  
Predatory Activity ◽  
The Common ◽  
Drill Holes

Garassino<em> et al.</em> (2012) reported on a rich community of decapod crustaceans including axiideans, gebiideans, anomurans, and brachyurans from the Zanclean (Early Pliocene) of the “La Serra” quarry near San Miniato (Pisa, Tuscany, central Italy). In this decapod-rich assemblage some carapaces of the common pebble crab<em> Ristoria pliocaenica</em> (Ristori, 1891) (<em>Leucosiidae Samouelle</em>, 1819) are drilled in characteristic ways, due to the predatory activity of individuals belonging to two different taxa of marine clades, possibly naticids (Gastropoda, Naticoidea), and to octopodids (Cephalopoda, Octopoda). This is the first report of direct evidence of predation by cephalopods on crabs in the fossil record.

Examples of twinning and parallel growth in zircons from some Precambrian granites and gneisses

1974 ◽  
Vol 39 (305) ◽  
pp. 587-594 ◽  
Author(s):  
J. Jocelyn ◽  
R. T. Pidgeon
Keyword(s):  
Late Stage ◽  
Common Occurrence ◽  
Chemical Corrosion ◽  
Growth History ◽  
History Of ◽  
Growth Zones ◽  
The Common ◽  
Transverse Fractures ◽  
Parallel Growth

SummaryGrowth twins, parallel growths, and necked crystals are described from zircon populations from granitic gneisses from the Precambrian of SW. Greenland. From observations of the distribution of internal growth zones it is concluded that whereas twinning takes place early in the growth history of elbow twins it can occur at any time during crystallization of the zircon. Parallel growth is attributed to a process of synneusis or attachment of zircons that have initially undergone separate growth histories. This implies that viscosity conditions of the rocks were low enough to permit the movement and collision of growing zircon crystals. The common occurrence of zircons with central constrictions, sometimes superimposed on transverse fractures, in zircon suites from the granitic gneisses is explained in terms of late-stage chemical corrosion accompanied by brittle fracturing.

scholarly journals Approaching the Black Hole by Numerical Simulations

Universe ◽  
2019 ◽  
Vol 5 (5) ◽  
pp. 99 ◽  
Author(s):  
Christian Fendt
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Direct Evidence ◽  
Dynamical Evolution ◽  
Numerical Code ◽  
Physical Processes ◽  
Hydrodynamic Simulations ◽  
Environmental Material ◽  
Physical Laws ◽  
Radiative Interaction

Black holes represent extreme conditions of physical laws. Predicted about a century ago, they are now accepted as astrophysical reality by most of the scientific community. Only recently has more direct evidence of their existence been found—the detection of gravitational waves from black hole mergers and of the shadow of a supermassive black hole in the center of a galaxy. Astrophysical black holes are typically embedded in an active environment which is affected by the strong gravity. When the environmental material emits radiation, this radiation may carry imprints of the black hole that is hosting the radiation source. In order to understand the physical processes that take place in the close neighborhood of astrophysical black holes, numerical methods and simulations play an essential role. This is simply because the dynamical evolution and the radiative interaction are far too complex in order to allow for an analytic solution of the physical equations. A huge progress has been made over the last decade(s) in the numerical code development, as well as in the computer power that is needed to run these codes. This review tries to summarize the basic questions and methods that are involved in the undertaking of investigating the astrophysics of black holes by numerical means. It is intended for a non-expert audience interested in an overview over this broad field. The review comes along without equations and thus without a detailed expert discussion of the underlying physical processes or numerical specifics. Instead, it intends to illustrate the richness of the field and to motivate further reading. The review puts some emphasis on magneto-hydrodynamic simulations but also touches radiation transfer and merger simulations, in particular pointing out differences in these approaches.

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