Cerebral microbleeds: Beyond the macroscope

2019 ◽  
Vol 14 (5) ◽  
pp. 468-475 ◽  
Author(s):  
Maud Pétrault ◽  
Barbara Casolla ◽  
Thavarak Ouk ◽  
Charlotte Cordonnier ◽  
Vincent Bérézowski

While being increasingly recognized in clinical routine, brain microbleeds remain a puzzling finding for physicians. These small dot-like lesions are thought to be old perivascular collections of hemosiderin deposits. They can be found in different neurological settings such as cerebrovascular or neurodegenerative diseases. While their microscopic size would suggest considering these lesions as anecdotal, they are now regarded as biomarkers of severity of an underlying cerebrovascular disease. Their natural history and the interactions with surrounding brain cells remain unknown. However, their presence may impact therapeutic decisions. Deciphering the biological mechanisms leading to, or following microbleeds would enable us to address a key question: do microbleeds arise and impact the surrounding parenchyma like a miniature version of intracerebral hemorrhages or do they represent a different kind of injury? We hereby discuss, based on both clinical and experimental literature, the gap between the definition of microbleeds coming from neuroimaging and the pathophysiological hypotheses raised from histopathological and experimental data. Our analysis supports the need for a convergent effort from clinicians and basic scientists to go beyond the current “macro” view and disclose the cellular and molecular insights of these cerebral hemorrhagic microlesions.

1982 ◽  
Vol 47 (3) ◽  
pp. 766-775 ◽  
Author(s):  
Václav Kolář ◽  
Jan Červenka

The paper presents results obtained by processing a series of published experimental data on heat and mass transfer during evaporation of pure liquids from the free board of a liquid film into the turbulent gas phone. The data has been processed on the basis of the earlier theory of mechanism of heat and mass transfer. In spite of the fact that this process exhibits a strong Stefan's flow, the results indicate that with a proper definition of the driving forces the agreement between theory and experiment is very good.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
María Jiménez-Buedo

AbstractReactivity, or the phenomenon by which subjects tend to modify their behavior in virtue of their being studied upon, is often cited as one of the most important difficulties involved in social scientific experiments, and yet, there is to date a persistent conceptual muddle when dealing with the many dimensions of reactivity. This paper offers a conceptual framework for reactivity that draws on an interventionist approach to causality. The framework allows us to offer an unambiguous definition of reactivity and distinguishes it from placebo effects. Further, it allows us to distinguish between benign and malignant forms of the phenomenon, depending on whether reactivity constitutes a danger to the validity of the causal inferences drawn from experimental data.


2013 ◽  
Vol 778 ◽  
pp. 418-423
Author(s):  
Jakub Sandak ◽  
Anna Sandak ◽  
Mariapaola Riggio ◽  
Ilaria Santoni ◽  
Dusan Pauliny

A special software simulating changes to wood due to various processes (either treatment or degradation) has been developed within the SWORFISH (Superb Wood Surface Finishing) project. The definition of the material modifications due to processes is based on the expert knowledge and/or experimental data. The dedicated algorithm simulates material modifications (with a special focus on surface) taking into account original material characteristics (evaluated by means of NDT techniques) and setting of process parameters. In this way, it is possible to analyze the sequence of processes (i.e. material modifications) and to estimate properties of the resulting product. Two case studies are presented for illustration of the potential uses of the SWORFISH approach in the field of timber structures.


1975 ◽  
Vol 42 (3) ◽  
pp. 552-556 ◽  
Author(s):  
A. J. Padgaonkar ◽  
K. W. Krieger ◽  
A. I. King

The computation of angular acceleration of a rigid body from measured linear accelerations is a simple procedure, based on well-known kinematic principles. It can be shown that, in theory, a minimum of six linear accelerometers are required for a complete definition of the kinematics of a rigid body. However, recent attempts in impact biomechanics to determine general three-dimensional motion of body segments were unsuccessful when only six accelerometers were used. This paper demonstrates the cause for this inconsistency between theory and practice and specifies the conditions under which the method fails. In addition, an alternate method based on a special nine-accelerometer configuration is proposed. The stability and superiority of this approach are shown by the use of hypothetical as well as experimental data.


1895 ◽  
Vol 2 (5) ◽  
pp. 207-214 ◽  
Author(s):  
Arthur Smith Woodward

The remains of fishes discovered in the Cambridge Greensand are all very fragmentary, and have not hitherto been subjected to the detailed comparison with other Cretaceous Ichthyolites which their interesting stratigraphical position renders desirable. Many specimens, however, are capable of at least generic determination, while many others are sufficiently characteristic fragments for the definition of the species. The present writer has thus been much interested during the past few years in studying collections of these fossils, and the following notes embody some of the results in reference to the ganoid fishes. The British Museum (Natural History) having recently acquired the collection made from the Cambridge Greensand by Mr. Thomas Jesson, F.G.S., nearly all the known species are now represented here; but the writer has also availed himself of the privilege of making use of the fine series in the Woodwardian Museum, Cambridge, and the Philosophical Society's Museum, York, thanks to the kindness of Professor McKenny Hughes, Mr. Henry Woods, and Mr. H. M. Platnauer. Mr. James Carter, M.R.C.S., has also kindly lent some Pycnodont jaws from his private collection


1957 ◽  
Vol 11 (3) ◽  
pp. 538-538

The eighth plenary assembly of the International Radio Consultative Committee (CCIR) was held in Warsaw from August 9 to September 13, 1956, under the chairmanship of Professor Pawel Szulkin (Poland). The assembly elected with an absolute majority Dr. E. Metzler (Switzerland) as Director. The assembly considered a report which dealt with the activities of the fourteen established study groups as well as proposals to reorganize the study groups. The Warsaw decisions modifying procedures experimentally for the future were the outcome of proposals by the Organization and Finance Committees, the CCIR Secretariat and of discussions of the problem in the plenary assembly. The study groups were to remain the same in number and the allocation of work was in general the same, though it was felt desirable to give a more precise definition of their terms of reference. Among the resolutions adopted by the assembly, a number dealt with the length, content and quantity of documents submitted to the chairmen of the study groups, emphasizing that these should be as short as possible, as few as possible and that they should contain only the minimum indispensable mathematical formulae or numerical and experimental data. The new system was also expected to improve the position of distant countries which had so far experienced great difficulty in receiving preliminary documentation in sufficient time before plenary assemblies. The Technical Assistance Committee recommended the creation of a joint CCIR-International Telegraph and Telephone Consultative Committee (CCITT) committee to consider the ways and means whereby technical assistance was at present granted and to make suggestions for improvements, as far as telecommunication was concerned, to the ITU Administrative Council.


Author(s):  
Grzegorz Dec ◽  

In the paper is presented review of some approaches corelated with subject of using fractional derivatives in control system theory. Popular algorithms used in the industry are presented, along with relating designing methodology. Using of fractional derivatives calculations is relatively new concept, but constantly getting increasing interest. Deliberation in recent years indicate that many scientific problems like thermodynamic or biology problems can be well considered and modeled by fractional order derivatives. On the market there is available tools that support a processes of identification and regulators designing, based on experimental data. One of such tools are toolbox CRONE for MATLAB, which contains three modules: mathematical, identifying, system control designing. That toolbox allows implementation of CRONE regulators with different level of complexity. Other tool is FOMCON, which also is a toolbox for MATLAB and it is based on already existed toolbox FOTF. FOMCON allows to identifying of control system and PIλDµ regulator designing. This article is aiming to present current state of art, discussion about existing tools and concepts correlated with fractional order derivatives and their usage in control system theory, like: gamma function, definition of fractional derivative, Laplace transform and basics of control system theory.


2020 ◽  
Vol 5 (5) ◽  
pp. 273-279 ◽  
Author(s):  
Sophie Abrassart ◽  
Franck Kolo ◽  
Sébastian Piotton ◽  
Joe Chih-Hao Chiu ◽  
Patrick Stirling ◽  
...  

Frozen shoulder, a common and debilitating shoulder complaint, has been the subject of uncertainty within the scientific literature and clinical practice. We performed an electronic PubMed search on all (1559) articles mentioning ‘frozen shoulder’ or ‘adhesive capsulitis’ to understand and qualify the range of naming, classification and natural history of the disease. We identified and reviewed six key thought leadership papers published in the past 10 years and all (24) systematic reviews published on frozen shoulder or adhesive capsulitis in the past five years. This revealed that, while key thought leaders such as the ISAKOS Upper Extremity Council are unequivocal that ‘adhesive capsulitis’ is an inappropriate term, the long-term and short-term trends showed the literature (63% of systematic reviews assessed) preferred ‘adhesive capsulitis’. The literature was divided as to whether or not to classify the complaint as primary only (9 of 24) or primary and secondary (9 of 24); six did not touch on classification. Furthermore, despite a systematic review in 2016 showing no evidence to support a three-phase self-limiting progression of frozen shoulder, 11 of 12 (92%) systematic reviews that mentioned phasing described a three-phase progression. Eight (33%) described it as ‘self-limiting’, three (13%) described it as self-limiting in ‘nearly all’ or ‘most’ cases, and six (25%) stated that it was not self-limiting; seven (29%) did not touch on disease resolution. We call for a data and patient-oriented approach to the classification and description of the natural history of the disease, and recommend authors and clinicians (1) use the term ‘frozen shoulder’ over ‘adhesive capsulitis’, (2) use an updated definition of the disease which recognizes the often severe pain suffered, and (3) avoid the confusing and potentially harmful repetition of the natural history of the disease as a three-phase, self-limiting condition. Cite this article: EFORT Open Rev 2020;5:273-279.DOI: 10.1302/2058-5241.5.190032


1976 ◽  
Vol 4 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Neil C. Warren

Developments in the psychology of religion during the 1960s are discussed. The upsurge in interest in the area since 1950 is noted. Special attention is given to advances in (1) the definition of religion; (2) the relation of religion and prejudice; and (3) personality correlates of religious behavior. However, it is suggested that the field still suffers from a paucity of experimental data, sampling deficiencies, the problem of legitimate control subjects, overenthusiastic generalization of findings, and lack of programmatic designs.


2019 ◽  
Vol 47 (18) ◽  
pp. 9511-9523
Author(s):  
Diana Buitrago ◽  
Laia Codó ◽  
Ricard Illa ◽  
Pau de Jorge ◽  
Federica Battistini ◽  
...  

Abstract We present Nucleosome Dynamics, a suite of programs integrated into a virtual research environment and created to define nucleosome architecture and dynamics from noisy experimental data. The package allows both the definition of nucleosome architectures and the detection of changes in nucleosomal organization due to changes in cellular conditions. Results are displayed in the context of genomic information thanks to different visualizers and browsers, allowing the user a holistic, multidimensional view of the genome/transcriptome. The package shows good performance for both locating equilibrium nucleosome architecture and nucleosome dynamics and provides abundant useful information in several test cases, where experimental data on nucleosome position (and for some cases expression level) have been collected for cells under different external conditions (cell cycle phase, yeast metabolic cycle progression, changes in nutrients or difference in MNase digestion level). Nucleosome Dynamics is a free software and is provided under several distribution models.


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