pattern distribution
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2022 ◽  
pp. neurintsurg-2021-018086
Author(s):  
Eytan Raz ◽  
Adam Goldman-Yassen ◽  
Anna Derman ◽  
Ahrya Derakhshani ◽  
John Grinstead ◽  
...  

BackgroundHigh-resolution vessel wall MRI (VWI) is increasingly used to characterize intramural disorders of the intracranial vasculature unseen by conventional arteriography.ObjectiveTo evaluate the use of VWI for surveillance of flow diverter (FD) treated aneurysms.Materials and methodsRetrospective study of 28 aneurysms (in 21 patients) treated with a FD (mean 57 years; 14 female). All examinations included VWI and a contemporaneously obtained digital subtraction angiogram. Multiplanar pre- and post-gadolinium 3D, variable flip-angle T1 black-blood VWI was obtained using delay alternating nutation for tailored excitation (DANTE) at 3T. 3D time-of-flight MR angiography (MRA) was also carried out. Images were assessed for in-stent stenosis, aneurysm occlusion, presence and pattern/distribution of aneurysmal or parent vessel gadolinium enhancement.ResultsThe VWI-MRI was performed on average at 361±259 days after the intervention. Follow-up DSA was performed at 338±254 days postintervention. Good or excellent black-blood angiographic quality was recorded in 22/28 (79%) pre-contrast and 21/28 (75%) post-contrast VWI, with no cases excluded for image quality. Aneurysm enhancement was noted in 24/28 (85.7%) aneurysms, including in 79% of angiographically occluded aneurysms and 100% of angiographically non-occluded aneurysms. Enhancement of the stented parent-vessel wall occurred significantly more often when aneurysm enhancement was present (92% vs 33%, p=0.049).ConclusionAdvanced VWI produces excellent depiction of FD-treated aneurysms, with robust evaluation of the parent vessel and aneurysm wall to an extent not achievable with conventional MRI/MRA. Gadolinium enhancement may, however, continue even after enduring catheter angiographic occlusion, confounding interpretation, and requiring cognizance of this potentially prolonged effect in such patients.


Entropy ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 37
Author(s):  
Tim Gutjahr ◽  
Karsten Keller

Among various modifications of the permutation entropy defined as the Shannon entropy of the ordinal pattern distribution underlying a system, a variant based on Rényi entropies was considered in a few papers. This paper discusses the relatively new concept of Rényi permutation entropies in dependence of non-negative real number q parameterizing the family of Rényi entropies and providing the Shannon entropy for q=1. Its relationship to Kolmogorov–Sinai entropy and, for q=2, to the recently introduced symbolic correlation integral are touched.


2021 ◽  
pp. 96-99
Author(s):  
Alexander C. Katoulis ◽  
Efthymia Soura ◽  
Konstantina Diamanti ◽  
Evangelia Bozi
Keyword(s):  

2021 ◽  
Vol 923 (1) ◽  
pp. 012026
Author(s):  
Osama Mohammed Saleh Abdullah ◽  
Ammar Jassim Mohammed

Abstract The spatial pattern of species is an important feature to understand why these species coexist and remain in position or not, and using the single Ripley function and the L(r) function, we analyzed the spatial pattern of types of broad-leaf tree and tree covers and the needles for mixed brawls in the forests of Mount Gara, using PASSAGE V.2, L(r) analysis of the species under study showed a variation in the pattern distribution of trees and gave the highest percentage of random form distribution pattern with a cluster pattern of 11.25%, Through the ratios and forms of distribution of the L(r) function of the various samples of the study, we find that these stands generally tend to be regular, indicating that these species remain at the end of the life cycle in the structure of a more stable stand.


PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0259136
Author(s):  
Delphine Vettese ◽  
Trajanka Stavrova ◽  
Antony Borel ◽  
Juan Marín ◽  
Marie-Hélène Moncel ◽  
...  

During the Paleolithic period, bone marrow extraction was an essential source of fat nutrients for hunter-gatherers especially throughout cold and dry seasons. This is attested by the recurrent findings of percussion marks in osteological material from anthropized archaeological levels. Among them some showed indicators that the marrow extraction process was part of a butchery cultural practice, meaning that the inflicted fracturing gestures and techniques were recurrent, standardized and counter-intuitive. In order to assess the weight of the counter-intuitive factor in the percussion mark pattern distribution, we carried out an experiment that by contrast focuses on the intuitive approach of fracturing bones to extract marrow, involving individual without experience in this activity. We wanted to evaluate the influence of bone morphology and the individuals’ behaviour on the distribution of percussion marks. Twelve experimenters broke 120 limb bones, a series of 10 bones per individual. During the experiment, information concerning the fracture of the bones as well as individual behaviour was collected and was subsequently compared to data from the laboratory study of the remains. Then, we applied an innovative GIS (Geographic Information System) method to analyze the distribution of percussion marks to highlight recurrent patterns. Results show that in spite of all the variables there is a high similarity in the distribution of percussion marks which we consider as intuitive patterns. The factor influenced the distribution for the humerus, radius-ulna and tibia series is the bone morphology, while for the femur series individual behaviour seems to have more weight in the distribution. To go further in the subject we need to compare the intuitive models with the distributions of percussion marks registered in fossil assemblages. Thus, it would be possible to propose new hypotheses on butchering practices based on the results presented in this work.


Zootaxa ◽  
2021 ◽  
Vol 5052 (4) ◽  
pp. 501-528
Author(s):  
JULIO PARAPAR ◽  
MANAL AL-KANDARI ◽  
MARÍA CANDÁS ◽  
JUAN MOREIRA

Polyophthalmus zhadanae sp. nov. (Annelida, Opheliidae), is described from the coast of Kuwait and Saudi Arabia (Arabian Gulf) after specimens collected in the intertidal and shallow subtidal. This new species is characterised by the body pigmentation pattern, distribution of lateral eyes, presence of small dorsal and ventral parapodial cirri and pygidial features. External and internal anatomy was described after examination with SEM and micro-CT. The presence of several body structures in the genus such as a cephalic palpode-like papilla is discussed. Furthermore, the diversity of genus Polyophthalmus and the presence of Polyophthalmus pictus (Dujardin, 1839) in the Indo-Pacific is reviewed and a key to species is provided.  


2021 ◽  
Vol 7 (10) ◽  
pp. 833
Author(s):  
Francesca Degola ◽  
Giorgio Spadola ◽  
Marco Forgia ◽  
Massimo Turina ◽  
Lucia Dramis ◽  
...  

Microbial multi-level interactions are essential to control the success of spreading and survival of most microbes in natural environments. Phytopathogenic mycotoxigenic fungal species, such as Aspergillus flavus, represent an important issue in food safety. Usually, non-toxigenic strains are exploited for biocontrol strategies to mitigate infections by toxigenic strains. To comprehend all the biological variables involved in the aflatoxin biosynthesis, and to possibly evaluate the interplay between A. flavus toxigenic and non-toxigenic strains during intraspecific biocompetition, the “virological” perspective should be considered. For these reasons, investigations on mycoviruses associated to A. flavus populations inhabiting specific agroecosystems are highly desirable. Here, we provide the first accurate characterization of the novel mycovirome identified within an A. flavus wild population colonizing the maize fields of northern Italy: a selection of A. flavus strains was biologically characterized and subjected to RNAseq analysis, revealing new mycoviruses and a peculiar geographic pattern distribution in addition to a 20% rate of infection. More interestingly, a negative correlation between viral infection and aflatoxin production was found. Results significantly expanded the limited existent data about mycoviruses in wild A. flavus, opening new and intriguing hypotheses about the ecological significance of mycoviruses.


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