layered pattern
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2020 ◽  
Vol 5 (4) ◽  
pp. 1793-1810
Author(s):  
Pedro Santos ◽  
Jakob Mann ◽  
Nikola Vasiljević ◽  
Elena Cantero ◽  
Javier Sanz Rodrigo ◽  
...  

Abstract. We present novel measurements from a field campaign that aims to characterize multi-scale flow patterns, ranging from 0.1 to 10 km in a time-resolved manner, in a mountainous region in northwestern Spain with a mountain–valley–ridge configuration. We select two flow cases where topographic-flow interactions were measured by five synchronized scanning Doppler wind lidars along a 10 km transect line that includes a cross section of the valley. We observed a hydraulic jump in the lee side of the mountain. For this case, the Froude number transition from supercritical (>1) at the mountain to subcritical (<1) at the valley is in agreement with previous experiments at a smaller scale. For a 1-year period, the measurements show such a transition about 10 % of the time, indicating a possible high occurrence of hydraulic jumps. The second flow case presents valley winds that are decoupled from the northerly flow aloft and show a stratified layered pattern, which is well captured by the lidar scans and complementary ground-based observations. These measurements can aid the evaluation of multi-scale numerical models as well as improve our knowledge with regards to mountain meteorology.



2019 ◽  
Vol 21 (12) ◽  
pp. 1421-1430 ◽  
Author(s):  
Michele Russo ◽  
Hyung Oh Kim ◽  
Osamu Kurihara ◽  
Makoto Araki ◽  
Hiroki Shinohara ◽  
...  

Abstract Aims  Layered plaques represent signs of previous plaque destabilization. A recent study showed that acute coronary syndrome (ACS) patients with layered culprit plaque have more vulnerability at the culprit lesion and systemic inflammation. We aimed to compare the characteristics of non-culprit plaques between patients with or without layered plaque at the culprit lesion. We also evaluated the characteristics of layered non-culprit plaques, irrespective of culprit plaque phenotype. Methods and results We studied ACS patients who had undergone pre-intervention optical coherence tomography (OCT) imaging. The number of non-culprit lesions was evaluated on coronary angiogram and morphological characteristics of plaques were studied by OCT. In 349 patients, 99 (28.4%) had layered culprit plaque. The number of non-culprit plaques in patients with or without layered culprit plaque was similar (3.2 ± 0.8 and 2.8 ± 0.8, P = 0.23). Among 465 non-culprit plaques, 145 from patients with layered culprit plaque showed a higher prevalence of macrophage infiltration (71.0% vs. 60.9%, P = 0.050). When analysed irrespective of culprit plaque phenotype, layered non-culprit plaques showed higher prevalence of lipid (93.3% vs. 86.0%, P = 0.028), thin cap fibroatheroma (29.7% vs. 13.7%, P &lt; 0.001), and macrophage infiltration (82.4% vs. 54.0%, P &lt; 0.001) than non-layered plaques. Plaques with layered phenotype at both culprit and non-culprit lesions had the highest vulnerability. Conclusion  In ACS patients, those with layered phenotype at the culprit lesion demonstrated greater macrophage infiltration at the non-culprit sites. Layered plaque at the non-culprit lesions was associated with more features of plaque vulnerability, particularly when the culprit lesion also had a layered pattern.



2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tsuyoshi Tsukada ◽  
Rei Kurita

Abstract Physicochemical systems are strongly modified by spatial confinement; the effect is more pronounced the stronger the confinement is, making its influence particularly important nanotechnology applications. For example, a critical point of a phase transition is shifted by a finite size effect; structure can be changed through wetting to a container wall. Recently, it has been shown that pattern formation during a phase separation is changed when a system is heterogeneously quenched instead of homogeneously. Flux becomes anisotropic due to a heterogeneous temperature field; this suggests that the mechanism behind heterogeneous quenching is different from that of homogeneous quenching. Here, we numerically study the confinement effect for heterogeneously quenched systems. We find that the pattern formed by the phase separation undergoes a topological change with stronger confinement i.e. when the height of a simulation box is varied, transforming from a one-dimensional layered pattern to a two-dimensional pattern. We show that the transition is induced by suppression of the heterogeneous flux by spatial confinement. Systems with heterogeneous flux are ubiquitous; the effect is expected to be relevant to a wide variety of non-equilibrium processes under the action of spatial confinement.



2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
H Okamoto ◽  
T Kume ◽  
R Yamada ◽  
Y Neishi ◽  
S Uemura

Abstract Background In patients with stable angina pectoris (SAP), exact mechanism of plaque progression overtime is still unclear due to lack of histological evaluation. Directional coronary atherectomy (DCA) allows for the differential cutting of atherosclerotic lesions and for the histological examination. Purpose The aims of this study were to compare the histological features obtained by DCA and layered pattern (LP) by OCT, and to establish the prevalence and clinical characteristics of LP in culprit lesion form SAP patients. Methods SAP patients who underwent OCT imaging guide PCI in our medical school hospital between June 2016 and June 2018 were included into this study. This was two-fold histological and clinical studies. In a histological study, we evaluated histological features of 42 specimens from 18 patients who underwent DCA and compare OCT findings. Lesions were classified into the following categories based on the OCT finding before DCA cutting; homogeneous or heterogeneous group. Furthermore, lesions in heterogeneous group were classified into 2 categories; LP or non-LP group. In a clinical study, 205 target lesions form 205 patients were categorized as shown above at minimum lumen area (MLA) sites. Plaque characteristics were compared among these groups. Results In the histological study, 9 (21.4%) specimens were classified in homogeneous group and 33 (78.6%) in heterogeneous group. In 33 heterogeneous group, LP group were observed in 12 specimens (36.3%). Of 12 LP group, 10 LP group consisted of intramural thrombosis. In clinical study, 39 (19.0%) lesion were classified in homogeneous group and 166 (81.0%) in heterogeneous group. In 166 heterogeneous group, LP group were observed in 75 lesions (45.2%). Of heterogeneous group, LP group had significantly smaller MLA (1.5±0.9 mm2 vs 1.9±1.0 mm2, p<0.05) and higher rate of microchannels (57.3% vs 15.4%, p<0.05) than non-LP group. A representative layered pattern case Conclusions LP in culprit lesion with SAP was significantly associated with intramural thrombosis. MLA sites in LP was significantly smaller than in non-LP group. These data suggest that thrombus formation and subsequent their organization overtime might contribute to the plaque progression even in SAP patients.



2019 ◽  
Author(s):  
Igor Smolyar ◽  
Timothy Bromage ◽  
Martin Wikelski

Various natural patterns—such as terrestrial sand dune ripples, lamellae in vertebrate bones, growth increments in fish scales and corals, aorta and lamellar corpuscle of humans and animals—comprise layers of different thicknesses and lengths. Microstructures in manmade materials—such as alloys, perlite steels, polymers, ceramics, and ripples induced by laser on the surface of graphen—also exhibit layered structures. These layered patterns form a record of internal and external factors regulating pattern formation in their various systems, making it potentially possible to recognize and identify in their incremental sequences trends, periodicities, and events in the formation history of these systems. The morphology of layered systems plays a vital role in developing new materials and in biomimetic research. The structures and sizes of these two-dimensional (2-D) patterns are characteristically anisotropic: That is, the number of layers and their absolute thicknesses vary significantly in different directions. The present work develops a method to quantify the morphological characteristics of layered patterns that accounts for anisotropy in the object of study. To reach this goal, we use Boolean functions and an N-partite graph to formalize layer structure and thickness across a 2-D plane and to construct charts of 1) “layer thickness vs. layer number” and 2) “layer area vs. layer number.” We present a parameter for structural disorder in a layered pattern (DStr) to describe the deviation of a study object’s anisotropic structure from an isotropic analog and illustrate that charts and DStr could be used as local and global morphological characteristics describing various layered systems such as images of, for example, geological, atmospheric, medical, materials, forensic, plants, and animals. Suggested future experiments could lead to new insights into layered pattern formation.



Author(s):  
Igor Smolyar ◽  
Timothy Bromage ◽  
Martin Wikelski

Various natural patterns—such as terrestrial sand dune ripples, lamellae in vertebrate bones, growth increments in fish scales and corals, aorta and lamellar corpuscle of humans and animals—comprise layers of different thicknesses and lengths. Microstructures in manmade materials—such as alloys, perlite steels, polymers, ceramics, and ripples induced by laser on the surface of graphen—also exhibit layered structures. These layered patterns form a record of internal and external factors regulating pattern formation in their various systems, making it potentially possible to recognize and identify in their incremental sequences trends, periodicities, and events in the formation history of these systems. The morphology of layered systems plays a vital role in developing new materials and in biomimetic research. The structures and sizes of these two-dimensional (2-D) patterns are characteristically anisotropic: That is, the number of layers and their absolute thicknesses vary significantly in different directions. The present work develops a method to quantify the morphological characteristics of layered patterns that accounts for anisotropy in the object of study. To reach this goal, we use Boolean functions and an N-partite graph to formalize layer structure and thickness across a 2-D plane and to construct charts of 1) “layer thickness vs. layer number” and 2) “layer area vs. layer number.” We present a parameter for structural disorder in a layered pattern (DStr) to describe the deviation of a study object’s anisotropic structure from an isotropic analog and illustrate that charts and DStr could be used as local and global morphological characteristics describing various layered systems such as images of, for example, geological, atmospheric, medical, materials, forensic, plants, and animals. Suggested future experiments could lead to new insights into layered pattern formation.



2018 ◽  
Author(s):  
Igor Smolyar ◽  
Timothy Bromage ◽  
Martin Wikelski

Various natural patterns—such as terrestrial sand dune ripples, lamellae in vertebrate bones, growth increments in fish scales and corals, aorta and lamellar corpuscle of humans and animals—comprise layers of different thicknesses and lengths. Microstructures in manmade materials—such as alloys, perlite steels, polymers, ceramics, and ripples induced by laser on the surface of graphen—also exhibit layered structures. These layered patterns form a record of internal and external factors regulating pattern formation in their various systems, making it potentially possible to recognize and identify in their incremental sequences trends, periodicities, and events in the formation history of these systems. The morphology of layered systems plays a vital role in developing new materials and in biomimetic research. The structures and sizes of these two-dimensional (2-D) patterns are characteristically anisotropic: That is, the number of layers and their absolute thicknesses vary significantly in different directions. The present work develops a method to quantify the morphological characteristics of layered patterns that accounts for anisotropy in the object of study. To reach this goal, we use Boolean functions and an N-partite graph to formalize layer structure and thickness across a 2-D plane and to construct charts of 1) “layer thickness vs. layer number” and 2) “layer area vs. layer number.” We present a parameter for structural disorder in a layered pattern (DStr) to describe the deviation of a study object’s anisotropic structure from an isotropic analog and illustrate that charts and DStr could be used as local and global morphological characteristics describing various layered systems such as images of, for example, geological, atmospheric, medical, materials, forensic, plants, and animals. Suggested future experiments could lead to new insights into layered pattern formation.



mBio ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Anubama Rajan ◽  
Lucy Vela ◽  
Xi-Lei Zeng ◽  
Xiaomin Yu ◽  
Noah Shroyer ◽  
...  

ABSTRACTEnteroaggregativeEscherichia coli(EAEC) is an important diarrheal pathogen and a cause of both acute and chronic diarrhea. It is a common cause of pediatric bacterial diarrhea in developing countries. Despite its discovery in 1987, the intestinal tropism of the pathogen remains unknown. Cell lines used to study EAEC adherence include the HEp-2, T-84, and Caco-2 lines, but they exhibit abnormal metabolism and large variations in gene expression. Animal models either do not faithfully manifest human clinical symptoms or are cumbersome and expensive. Using human intestinal enteroids derived from all four segments of the human intestine, we find that EAEC demonstrates aggregative adherence to duodenal and ileal enteroids, with donor-driven differences driving a sheet-like and layered pattern. This contrasts with the colon, where segment-specific tropisms yielded a mesh-like adherence pattern dominated by interconnecting filaments. Very little to no aggregative adherence to jejunal enteroids was observed, regardless of the strain or donor, in contrast to a strong duodenal association across all donors and strains. These unique patterns of intestinal segment- or donor-specific adherence, but not the overall numbers of associated bacteria, were dependent on the major subunit protein of aggregative adherence fimbriae II (AafA), implying that the morphology of adherent clusters and the overall intestinal cell association of EAEC occur by different mechanisms. Our results suggest that we must give serious consideration to inter- and intrapatient variations in what is arguably the first step in pathogenesis, that of adherence, when considering the clinical manifestation of these infections.IMPORTANCEEAEC is a leading cause of pediatric bacterial diarrhea and a common cause of diarrhea among travelers and immunocompromised individuals. Heterogeneity in EAEC strains and lack of a good model system are major roadblocks to the understanding of its pathogenesis. Utilizing human intestinal enteroids to study the adherence of EAEC, we demonstrate that unique patterns of adherence are largely driven by unidentified factors present in different intestinal segments and from different donors. These patterns are also dependent on aggregative adherence fimbriae II encoded by EAEC. These results imply that we must also consider the contribution of the host to understand the pathogenesis of EAEC-induced inflammation and diarrhea.



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