scholarly journals ATSPINDŽIO SIMETRIJOS DETEKCIJOS YPATUMAI

Psichologija ◽  
2001 ◽  
Vol 24 ◽  
pp. 69-82
Author(s):  
Alvydas Šoliūnas ◽  
Ona Gurčinienė
Keyword(s):  
Experimental Data ◽  
Bilateral Symmetry ◽  
Detection Accuracy ◽  
Symmetry Detection ◽  
Experimental Procedure ◽  
Line Segments ◽  
Experimental Part ◽  
Horizontal Symmetry ◽  
Symmetry Number

Nors simetrija suvokiama iš pirmo žvilgsnio greitai ir be pastangų, nėra aišku, kaip vyksta šis procesas, kokie yra simetrijos detekcijos mechanizmai? Straipsnyje apžvelgiami įvairių simetrijos rūšių ypatumai, didžiausią dėmesį skiriant atspindžio simetrijai. Aptartos pagrindinės simetrijos detekcijos teorijos ir modeliai. Eksperimentinė straipsnio dalis skirta siekimui pagilinti turimas žinias eksperimentiniais rezultatais, gautais su kitokio tipo stimulais ir kitokia užduotimi, nei naudota kitų tyrinėtojų. Testo stimulai buvo 4, 6, 7, arba 8 vertikalių ir horizontalių linijos atkarpų figūros, o užduotis reikalavo nurodyti stimulų simetrijos tipą - vertikalios simetrijos, horizontalios simetrijos ar nesimetrinis. Figūra rodoma 10 ms, o maskuojantis stimulas pateikiamas po 20-95 ms, priklausomai nuo tiriamojo. Rezultatai patvirtino vertikalios atspindžio simetrijos dominavimą horizontalios atžvilgiu. Stimulo atkarpų skaičius neturėjo įtakos nei vertikalios, nei horizontalios simetrijos detekcijos tikslumui, o nesimetriniai stimulai daugumos tiriamųjų buvo detektuojami taip pat tiksliai, kaip ir vertikalios simetrijos stimulai. Autorių pasiūlyta eksperimentinė metodika, leisianti išaiškinti dėmesio dalyvavimą simetrijos detekcijoje. CHARACTERISTICS OF BILATERAL SYMMETRY DETECTION Alvydas Šoliūnas, Ona Gurčinienė SummaryAlthough the symmetry is detected very fast and without efforts, it is not known how this process is going on and what mechanisms make the detection of symmetry possible. This paper reviews the characteristics of the detection of various symmetry types giving the majority of attention to bilateral symmetry. The main theories and models of symmetry detection are discussed as well. Experimental part of the paper is devoted to extend the existing knowledge with experimental data which were obtained with the stimuli and procedure that differ from that used by other investigators. Test stimuli were figures consisting of four, six, seven, or eight horizontal and vertical line-segments, and the task for subjects was to answer what kind of stimulus was presented - vertically symmetrical, horizontally symmetrical, or asymmetrical. Test stimuli were presented very briefly (10 ms) followed by masking after 20-95 ms. Experimental results confirmed the advantage of vertical over horizontal symmetry. Number of line-segments did not influence the detection accuracy nor for vertical, nor for horizontal symmetry. Majority of subjects detected asymmetrical stimuli with the same accuracy as vertically symmetrical stimuli. Authors offer an experimental procedure that would enable to explain the role of attention in symmetry detection.

The Role of ON- and OFF-Channel Processing in the Detection of Bilateral Symmetry

Perception ◽  
10.1068/p3387 ◽  
2002 ◽  
Vol 31 (9) ◽  
pp. 1061-1072 ◽  
Author(s):  
Anna Brooks ◽  
Rick van der Zwan
Keyword(s):  
Bilateral Symmetry ◽  
Limited Range ◽  
Visual Scene ◽  
Performance Decrement ◽  
Symmetry Detection ◽  
Axis Orientation ◽  
Present Evidence ◽  
Detection Mechanisms

We present evidence that grouping for luminance does not take precedence over the detection of bilaterally symmetrical patterns. Using single-axis and double-axis images, we found that element pairs within which luminance is held constant drive symmetry-detection mechanisms more effectively than pairs within which luminance varies. Moreover, the performance decrement observed for patterns defined by element pairs within which luminance varies is not specific to interchannel variation. Luminance variation within the ON and OFF channels has the same effect as variation between the channels on the performance of axis-orientation identification tasks. It is argued that this constitutes possible evidence for subchannels within the ON and OFF channels. One of the characteristics of the subchannels is that each processes only a limited range of luminance steps. The implications of this type of luminance processing for the detection of symmetry in the visual scene are discussed.

РОЛЬ ФИЗИЧЕСКОЙ РАЗМИНКИ В ПОДГОТОВКЕ К ТРЕНИРОВОЧНЫМ ЗАНЯТИЯМ И СОРЕВНОВАНИЯМ ШАХМАТИСТОВ БГУ

2019 ◽  
pp. 63-65
Author(s):  
Судоргин Е.П. ◽  
Карсакова И.Н.
Keyword(s):  
Experimental Data ◽  
Sport Performance ◽  
Warm Up ◽  
Physical Exercises ◽  
Methods Of Evaluation ◽  
Mental Fitness ◽  
Physical Preparation ◽  
Tools And Methods

Аннотация: О роли разминки перед тренировкой и соревнованиями написано много научных статьей и диссертаций. Ещё больше о значимости физической подготовки спортсменов, в том числе и шахматистов. В то же время авторы считают, что вопросу физической подготовки шахматистов и в частности разминке в научной и научно-методической литературе уделяется недостаточно внимания. В своей статье авторы приводят собственные экспериментальные данные о влиянии физических упражнений (разминки) на умственную работоспособность студентов-шахматистов БГУ и как следствие на спортивные результаты команды. Ключевые слова: Шахматы, разминка, умственная работоспособность, средства и методы разминки, методы оценки результатов. Аннотация: Машыгуунун жана мелдештердин алдында даярдоонун ролу жөнүндө көптөгөн илимий макала жана диссертация жазылган. Ошондой эле илимий жана илимий-методикалык адабияттарда шахматка даярдоого көп көңүл бурулбай жатат. Макаланын авторлору шахмат ойногон студенттерге физикалык көнүгүүлөрдүн тийгизген таасири жөнүндө өздөрүнүн эксперименталдык маалыматтарын көргөзүштү. Түйүндүү сөздөр: Шахмат, акыл-дарамет, курулуштар жана ыкмалар, баа берүү жыйынтыгы боюнча кабыл алынат. Abstract: on the role of warm-up before training and competitions written many scientific articles and theses. More about the significance of the physical preparation of athletes, including players. At the same time, the authors believe that the issue of fit- ness players and in particular workout in scientific and scientific-methodical literature neglected. In his article the authors cite their own experimental data on the influence of physical exercises (warm-up) on the mental fitness of students-BSU players and as a result the sport performance team. Keywords: chess, warm-up, mental fitness, workout tools and methods, methods of evaluation results.

Role of Artesunate in Potentiation of β-lactam Against Methicillin Resistant Staphylococcus aureus (MRSA) Isolated from Bovine Mastitis and its Histopathology Impact In-Vivo Study

2020 ◽  
Keyword(s):  
Clavulanic Acid ◽  
Resistance Mechanism ◽  
Bovine Mastitis ◽  
Lethal Challenge ◽  
Experimental Procedure ◽  
Appropriate Treatment ◽  
Amoxicillin Clavulanic Acid ◽  
Mrsa Infection

This article discusses the augmenting influence of Artesunate (ART) in combination with β-lactams (amoxicillin/clavulanic acid) antibiotic in sepsis mice models infected by a lethal challenge dose of live coagulase positive enterotoxigenic (Sec) MRSA that was isolated from a case of chronic bovine mastitis. The main goal is to find an appropriate treatment to overcome resistance mechanism of MRSA towards β-lactams antibiotic. Fifty healthy adult Swiss mice divided into 5 equal groups were used in the experimental procedure. The infected group that treated with both ART and β-lactams (amoxicillin/clavulanic acid) antibiotic revealed complete inhibition of MRSA count with complete normal macroscopic and histopathological features. We suggest that ART can potentiate the antibacterial action of β-lactams (amoxicillin/Clavulanic) acid against MRSA infection. The combination of ART and antibiotic can overcome MRSA resistance mechanism and so could be considered a novel candidate to overcome mastitis and/or sepsis caused by MRSA.

scholarly journals Oxidation of Terpenoids to Achieve High-Value Flavor and Fragrances—Questioning Microalgae Oxidative Capabilities in the Biotransformation of the Sesquiterpene Valencene and of Selected Natural Apocarotenoids

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 821-830
Author(s):  
Davide De Simeis ◽  
Stefano Serra ◽  
Alessandro Di Fonzo ◽  
Francesco Secundo
Keyword(s):  
Experimental Data ◽  
Natural Products ◽  
Aqueous Medium ◽  
Photochemical Reaction ◽  
Substrate Oxidation ◽  
Market Size ◽  
Chlorella Sp ◽  
General Opinion ◽  
Natural Way

Natural flavor and fragrance market size is expected to grow steadily due to the rising consumer demand of natural ingredients. This market request is guided by the general opinion that the production of natural compounds leads to a reduction of pollution, with inherent advantages for the environment and people’s health. The biotransformation reactions have gained high relevance in the production of natural products. In this context, few pieces of research have described the role of microalgae in the oxidation of terpenoids. In this present study, we questioned the role of microalgal based oxidation in the synthesis of high-value flavors and fragrances. This study investigated the role of three different microalgae strains, Chlorella sp. (211.8b and 211.8p) and Chlorococcum sp. (JB3), in the oxidation of different terpenoid substrates: α-ionone, β-ionone, theaspirane and valencene. Unfortunately, the experimental data showed that the microalgal strains used are not responsible for the substrate oxidation. In fact, our experiments demonstrate that the transformation of the four starting compounds is a photochemical reaction that involves the oxygen as oxidant. Even though these findings cast a shadow on the use of these microorganisms for an industrial purpose, they open a new possible strategy to easily obtain nootkatone in a natural way by just using an aqueous medium, oxygen and light.

scholarly journals Elucidating the Complex Interactions between Stress and Epileptogenic Pathways

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Aaron R. Friedman ◽  
Luisa P. Cacheaux ◽  
Sebastian Ivens ◽  
Daniela Kaufer
Keyword(s):  
Experimental Data ◽  
Blood Brain Barrier ◽  
Inflammatory Cytokine ◽  
Stress Hormones ◽  
Brain Barrier ◽  
Barrier Dysfunction ◽  
Complex Interactions ◽  
Narrow Focus ◽  
Analytical Tools

Clinical and experimental data suggest that stress contributes to the pathology of epilepsy. We review mechanisms by which stress, primarily via stress hormones, may exacerbate epilepsy, focusing on the intersection between stress-induced pathways and the progression of pathological events that occur before, during, and after the onset of epileptogenesis. In addition to this temporal nuance, we discuss other complexities in stress-epilepsy interactions, including the role of blood-brain barrier dysfunction, neuron-glia interactions, and inflammatory/cytokine pathways that may be protective or damaging depending on context. We advocate the use of global analytical tools, such as microarray, in support of a shift away from a narrow focus on seizures and towards profiling the complex, early process of epileptogenesis, in which multiple pathways may interact to dictate the ultimate onset of chronic, recurring seizures.

The PINHEAD/ZWILLE gene acts pleiotropically in Arabidopsis development and has overlapping functions with the ARGONAUTE1 gene

Development ◽  
1999 ◽  
Vol 126 (3) ◽  
pp. 469-481 ◽  
Author(s):  
K. Lynn ◽  
A. Fernandez ◽  
M. Aida ◽  
J. Sedbrook ◽  
M. Tasaka ◽  
...  
Keyword(s):  
Expression Patterns ◽  
Bilateral Symmetry ◽  
Floral Organ ◽  
Axillary Shoot ◽  
Apical Meristems ◽  
Shoot Apical Meristems ◽  
Positional Identity ◽  
Competence Factor ◽  
High Level

Several lines of evidence indicate that the adaxial leaf domain possesses a unique competence to form shoot apical meristems. Factors required for this competence are expected to cause a defect in shoot apical meristem formation when inactivated and to be expressed or active preferentially in the adaxial leaf domain. PINHEAD, a member of a family of proteins that includes the translation factor eIF2C, is required for reliable formation of primary and axillary shoot apical meristems. In addition to high-level expression in the vasculature, we find that low-level PINHEAD expression defines a novel domain of positional identity in the plant. This domain consists of adaxial leaf primordia and the meristem. These findings suggest that the PINHEAD gene product may be a component of a hypothetical meristem forming competence factor. We also describe defects in floral organ number and shape, as well as aberrant embryo and ovule development associated with pinhead mutants, thus elaborating on the role of PINHEAD in Arabidopsis development. In addition, we find that embryos doubly mutant for PINHEAD and ARGONAUTE1, a related, ubiquitously expressed family member, fail to progress to bilateral symmetry and do not accumulate the SHOOT MERISTEMLESS protein. Therefore PINHEAD and ARGONAUTE1 together act to allow wild-type growth and gene expression patterns during embryogenesis.

Activités cholinestérasiques dans le foie de Poulet Rôle de l'endoderme dans l'apparition d'activités cholinestérasiques dans la composante mésenchymateuse du tissu hépatique

Development ◽  
1971 ◽  
Vol 26 (3) ◽  
pp. 481-495
Author(s):  
Par Elisabeth Houssaint ◽  
Nicole Le Douarin
Keyword(s):  
Endothelial Cells ◽  
Chick Embryo ◽  
Cholinesterase Activity ◽  
Enzymic Activity ◽  
The Body ◽  
Hepatic Tissue ◽  
Experimental Procedure ◽  
Septum Transversum ◽  
Cholinesterase Activities

Cholinesterases in the chick liver. The role of the endoderm in the appearance of the activity of cholinesterases in the hepatic mesenchyme The histochemical method of Koelle & Friedenwald (1949), as modified by Gerebtzoff (1953), has been used to investigate the distribution of cholinesterases in the chick embryonic and adult liver. Non-specific cholinesterases and, in a lower proportion acetylcholinesterase, have been detected in the endothelial cells of blood sinusoids of both adult and embryonic hepatic tissue. The hepatocytes do not show any cholinesterase activity. Cholinesterases appear precociously in the liver mesenchyme, since they already occur in the septum transversum of the 3-day-old chick embryo. An experimental procedure preventing the invasion of the hepatic mesenchymal Anlage by the endodermic cords has been used. The experimentally isolated hepatic mesenchyme shows an important cholinesterase activity; therefore this activity does not depend on the presence of the hepatocytes. The grafting of the determined hepatic endodern in the somatopleura of the 3-day-old chick embryo results in the development of hepatic tissue in the body wall. In this experimentally produced liver, cholinesterase activities are present in the endothelial cells which have arisen from somatopleura mesenchymal cells, though normally somatopleural mesenchyme does not possess these enzymes. The role of the endoderm in the appearance of this enzymic activity in the somatopleural mesenchyme is discussed.

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