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Статті в журналах з теми "Activation pattern"
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Ravari, Reihaneh, and Hamid Reza Kobravi. "Identifying the Dynamics of Leg Muscle Activation During Human Gait Using Neural Oscillator and Fuzzy Compensator." International Clinical Neuroscience Journal 5, no. 3 (September 30, 2018): 106–12. http://dx.doi.org/10.15171/icnj.2018.21.
Повний текст джерелаАнотація:
Background: The goal of this study is to design a model in order to predict the muscle activation pattern because the muscle activation patterns contain valuable information about the muscle dynamics and movement patterns. Therefore, the goal of the presentation of this neural model is to identify the desired muscle activation patterns by Hopf chaotic oscillator during walking. Since the knee muscles activation has a significant effect on the movement pattern during walking, the main concentration of this study is to identify the knee muscles activation dynamics using a modeling technique. Methods: The electromyography (EMG) recording obtained from 5 healthy subjects that electrodes positioned on the tibialis-anterior (TA) and rectus femoris muscles on every 2 feet. In the proposed model, along with the chaotic oscillator, a fuzzy compensator was designed to face the unmolded dynamics. In fact, on the condition, the observed difference between the desired and actual activation patterns violate some specific quantitative ranges, the fuzzy compensator based on predefined rules modify the activity pattern produced by the Hopf oscillator. Results: Some quantitative measures used to evaluate the results. According to the achieved results, the proposed model could generate the trajectories, dynamics of which are similar to the muscle activation dynamics of the studied muscles. In this model, the generated activity pattern by the proposed model cannot follow the desired activity of the TA muscle as well as rectus femoris muscle. Conclusion: The similarity between the generated activity pattern by the model and the activation dynamics of Rectus- Femoris muscle was more in comparison with the similarity observed between activation pattern of Tibialis- Anterior and the pattern generated by the model. In other words, based on the recorded human data, the activation pattern of the Rectus- Femoris is more similar to a rhythmic pattern.
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Wohlert, Amy B., and Lisa Goffman. "Human Perioral Muscle Activation Patterns." Journal of Speech, Language, and Hearing Research 37, no. 5 (October 1994): 1032–40. http://dx.doi.org/10.1044/jshr.3705.1032.
Повний текст джерелаАнотація:
Task-dependent human motor organization in the perioral region was examined in eight normal adults who performed oral tasks including lip protrusion, chewing, and speech. Zero phase-lag correlations among EMG signals recorded from quadrants surrounding the lips were calculated in order to determine patterns of motor coupling. Results indicated that the perioral musculature is flexible in output organization. Activv in all quadrants was highly positively correlated during the protrusion task. During the chewing task, correlations were moderate, with a stronger pattern bilaterally across the upper and lower lips. The speech tasks showed lower levels of correlation among the quadrants, but again the pattern was more highly correlated bilaterally than ipsilaterally. Results are compared to studies of oral muscle innervation in humans and animals and also are related to hypotheses of cortical control patterns for oral movement.
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de Sá Pereira, Roberto Horácio. "Meaning Representationalism: between Representationalism and Qualia Realism." Grazer Philosophische Studien 93, no. 4 (November 7, 2016): 548–70. http://dx.doi.org/10.1163/18756735-09302005.
Повний текст джерелаАнотація:
The purpose of this article is to offer a new view of the key relation between the content and the conscious character of visual experience. The author aims to support the following claims. First, the author rejects the qualia realist claim that conscious character is an intrinsic, nonrepresentational property of visual experience, for example, a pattern of activation of neurons. However, the author also rejects the rival widespread representationalist claim that the conscious character of visual experience is identical to, or supervenes on, any specific property represented by visual experience. The positive proposal is the following. Conscious character is identical with those patterns of activation of neurons that are referentially or representationally alive. Conscious redness, for example, is a pattern of activations of neurons that is created normally only when brains of physical duplicates come in visual contact with some distal property and this pattern of activation is recruited by natural selection to represent that property. This is called meaning representationalism.
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Dibona, Gerald F., and Linda L. Sawin. "Functional significance of the pattern of renal sympathetic nerve activation." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 277, no. 2 (August 1, 1999): R346—R353. http://dx.doi.org/10.1152/ajpregu.1999.277.2.r346.
Повний текст джерелаАнотація:
To assess the renal functional significance of the pattern of renal sympathetic nerve activation, computer-generated stimulus patterns (delivered at constant integrated voltage) were applied to the decentralized renal sympathetic nerve bundle and renal hemodynamic and excretory responses determined in anesthetized rats. When delivered at the same integrated voltage, stimulus patterns resembling those observed in in vivo multifiber recordings of renal sympathetic nerve activity (diamond-wave patterns) produced greater renal vasoconstrictor responses than conventional square-wave patterns. Within diamond-wave patterns, increasing integrated voltage by increasing amplitude produced twofold greater renal vasoconstrictor responses than by increasing duration. With similar integrated voltages that were subthreshold for renal vasoconstriction, neither diamond- nor square-wave pattern altered glomerular filtration rate, whereas diamond- but not square-wave pattern reversibly decreased urinary sodium excretion by 25 ± 3%. At the same number of pulses per second, intermittent stimulation produced faster and greater renal vasoconstriction than continuous stimulation. At the same number of pulses per second, increases in rest period during intermittent stimulation proportionally augmented the renal vasoconstrictor response compared with that observed with continuous stimulation; the maximum augmentation of 55% occurred at a rest period of 500 ms. These results indicate that the pattern of renal sympathetic nerve stimulation (activity) significantly influences the rapidity, magnitude, and selectivity of the renal vascular and tubular responses.
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Lin, Jian-Zhi, Wen-Yu Chiu, Wei-Hsun Tai, Yu-Xiang Hong, and Chung-Yu Chen. "Ankle Muscle Activations during Different Foot-Strike Patterns in Running." Sensors 21, no. 10 (May 14, 2021): 3422. http://dx.doi.org/10.3390/s21103422.
Повний текст джерелаАнотація:
This study analysed the landing performance and muscle activity of athletes in forefoot strike (FFS) and rearfoot strike (RFS) patterns. Ten male college participants were asked to perform two foot strikes patterns, each at a running speed of 6 km/h. Three inertial sensors and five EMG sensors as well as one 24 G accelerometer were synchronised to acquire joint kinematics parameters as well as muscle activation, respectively. In both the FFS and RFS patterns, according to the intraclass correlation coefficient, excellent reliability was found for landing performance and muscle activation. Paired t tests indicated significantly higher ankle plantar flexion in the FFS pattern. Moreover, biceps femoris (BF) and gastrocnemius medialis (GM) activation increased in the pre-stance phase of the FFS compared with that of RFS. The FFS pattern had significantly decreased tibialis anterior (TA) muscle activity compared with the RFS pattern during the pre-stance phase. The results demonstrated that the ankle strategy focused on controlling the foot strike pattern. The influence of the FFS pattern on muscle activity likely indicates that an athlete can increase both BF and GM muscles activity. Altered landing strategy in cases of FFS pattern may contribute both to the running efficiency and muscle activation of the lower extremity. Therefore, neuromuscular training and education are required to enable activation in dynamic running tasks.
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Mitrushina, Maura, and John Stamm. "Task-induced differential cortical activation pattern." International Journal of Psychophysiology 17, no. 1 (June 1994): 15–23. http://dx.doi.org/10.1016/0167-8760(94)90051-5.
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Sharma, Meena, Shilpi Modi, Subash Khushu, and Manas K. Mandal. "Neural activation pattern in self-deceivers." Psychological Studies 55, no. 1 (March 2010): 71–76. http://dx.doi.org/10.1007/s12646-010-0008-3.
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Fernandes, Orlando, Liana Catrina Lima Portugal, Rita de Cássia S. Alves, Tiago Arruda-Sanchez, Eliane Volchan, Mirtes Garcia Pereira, Janaina Mourão-Miranda, and Letícia Oliveira. "How do you perceive threat? It’s all in your pattern of brain activity." Brain Imaging and Behavior 14, no. 6 (August 24, 2019): 2251–66. http://dx.doi.org/10.1007/s11682-019-00177-6.
Повний текст джерелаАнотація:
Abstract Whether subtle differences in the emotional context during threat perception can be detected by multi-voxel pattern analysis (MVPA) remains a topic of debate. To investigate this question, we compared the ability of pattern recognition analysis to discriminate between patterns of brain activity to a threatening versus a physically paired neutral stimulus in two different emotional contexts (the stimulus being directed towards or away from the viewer). The directionality of the stimuli is known to be an important factor in activating different defensive responses. Using multiple kernel learning (MKL) classification models, we accurately discriminated patterns of brain activation to threat versus neutral stimuli in the directed towards context but not during the directed away context. Furthermore, we investigated whether it was possible to decode an individual’s subjective threat perception from patterns of whole-brain activity to threatening stimuli in the different emotional contexts using MKL regression models. Interestingly, we were able to accurately predict the subjective threat perception index from the pattern of brain activation to threat only during the directed away context. These results show that subtle differences in the emotional context during threat perception can be detected by MVPA. In the directed towards context, the threat perception was more intense, potentially producing more homogeneous patterns of brain activation across individuals. In the directed away context, the threat perception was relatively less intense and more variable across individuals, enabling the regression model to successfully capture the individual differences and predict the subjective threat perception.
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Hicks, Robert A., Tonja Green, and Jerayr Haleblian. "The Thayer Scale Response Patterns of Type a and Type b College Students." Psychological Reports 65, no. 3_suppl2 (December 1989): 1167–70. http://dx.doi.org/10.2466/pr0.1989.65.3f.1167.
Повний текст джерелаАнотація:
Using Thayer's Activation-Deactivation Adjective Check List, the activation patterns of 95 Type A and 105 Type B college students were measured. The pattern of the group means suggests that Type A students are higher than Type B students on both energy and tension activation. When the responses of individuals were examined, the Type A students were 2.5 times more likely to exhibit this high activation pattern than was the case for the Type B students.
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Dai, Chenyun, and Xiaogang Hu. "Extracting and Classifying Spatial Muscle Activation Patterns in Forearm Flexor Muscles Using High-Density Electromyogram Recordings." International Journal of Neural Systems 29, no. 01 (January 10, 2019): 1850025. http://dx.doi.org/10.1142/s0129065718500259.
Повний текст джерелаАнотація:
The human hand is capable of producing versatile yet precise movements largely owing to the complex neuromuscular systems that control our finger movement. This study seeks to quantify the spatial activation patterns of the forearm flexor muscles during individualized finger flexions. High-density (HD) surface electromyogram (sEMG) signals of forearm flexor muscles were obtained, and individual motor units were decomposed from the sEMG. Both macro-level spatial patterns of EMG activity and micro-level motor unit distributions were used to systematically characterize the forearm flexor activation patterns. Different features capturing the spatial patterns were extracted, and the unique patterns of forearm flexor activation were then quantified using pattern recognition approaches. We found that the forearm flexor spatial activation during the ring finger flexion was mostly distinct from other fingers, whereas the activation patterns of the middle finger were least distinguishable. However, all the different activation patterns can still be classified in high accuracy (94–100%) using pattern recognition. Our findings indicate that the partial overlapping of neural activation can limit accurate identification of specific finger movement based on limited recordings and sEMG features, and that HD sEMG recordings capturing detailed spatial activation patterns at both macro- and micro-levels are needed.
Дисертації з теми "Activation pattern"
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Buettner, Karin, Thomas Kreisig, Norbert Sträter, and Thole Züchner. "Protein surface charge of trypsinogen changes its activation pattern." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-159779.
Повний текст джерелаАнотація:
Background: Trypsinogen is the inactive precursor of trypsin, a serine protease that cleaves proteins and peptides after arginine and lysine residues. In this study, human trypsinogen was used as a model protein to study the influence of electrostatic forces on protein–protein interactions. Trypsinogen is active only after its eight-amino-acid-long activation peptide has been cleaved off by another protease, enteropeptidase. Trypsinogen can also be autoactivated without the involvement of enteropeptidase. This autoactivation process can occur if a trypsinogen molecule is activated by another trypsin molecule and therefore is based on a protein–protein interaction. Results: Based on a rational protein design based on autoactivation-defective guinea pig trypsinogen, several amino acid residues, all located far away from the active site, were changed to modify the surface charge of human trypsinogen. The influence of the surface charge on the activation pattern of trypsinogen was investigated. The autoactivation properties of mutant trypsinogen were characterized in comparison to the recombinant wild-type enzyme. Surface-charged trypsinogen showed practically no autoactivation compared to the wild-type but could still be activated by enteropeptidase to the fully active trypsin. The kinetic parameters of surface-charged trypsinogen were comparable to the recombinant wild-type enzyme. Conclusion: The variant with a modified surface charge compared to the wild-type enzyme showed a complete different activation pattern. Our study provides an example how directed modification of the protein surface charge can be utilized for the regulation of functional protein–protein interactions, as shown here for human trypsinogen.
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Buettner, Karin, Thomas Kreisig, Norbert Sträter, and Thole Züchner. "Protein surface charge of trypsinogen changes its activation pattern." BioMed Central, 2014. https://ul.qucosa.de/id/qucosa%3A13121.
Повний текст джерелаАнотація:
Background: Trypsinogen is the inactive precursor of trypsin, a serine protease that cleaves proteins and peptides after arginine and lysine residues. In this study, human trypsinogen was used as a model protein to study the influence of electrostatic forces on protein–protein interactions. Trypsinogen is active only after its eight-amino-acid-long activation peptide has been cleaved off by another protease, enteropeptidase. Trypsinogen can also be autoactivated without the involvement of enteropeptidase. This autoactivation process can occur if a trypsinogen molecule is activated by another trypsin molecule and therefore is based on a protein–protein interaction. Results: Based on a rational protein design based on autoactivation-defective guinea pig trypsinogen, several amino acid residues, all located far away from the active site, were changed to modify the surface charge of human trypsinogen. The influence of the surface charge on the activation pattern of trypsinogen was investigated. The autoactivation properties of mutant trypsinogen were characterized in comparison to the recombinant wild-type enzyme. Surface-charged trypsinogen showed practically no autoactivation compared to the wild-type but could still be activated by enteropeptidase to the fully active trypsin. The kinetic parameters of surface-charged trypsinogen were comparable to the recombinant wild-type enzyme. Conclusion: The variant with a modified surface charge compared to the wild-type enzyme showed a complete different activation pattern. Our study provides an example how directed modification of the protein surface charge can be utilized for the regulation of functional protein–protein interactions, as shown here for human trypsinogen.
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Lebo, Timothy M. "Guiding object recognition : a shape model with co-activation networks /." Link to online version, 2005. http://hdl.handle.net/1850/993.
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Doull, Laura Elizabeth. "Inflammasome activation in ruminant cells infected with Chlamydia abortus." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/22082.
Повний текст джерелаАнотація:
Chlamydia abortus is the most common known infectious cause of ovine abortion worldwide but is rarely linked with bovine abortion. The reasons for this differential pathogenesis are unknown but may involve differences in innate immune recognition and immune responsiveness. This is supported by the observation that chlamydial abortion in sheep is associated with an inflammatory cytokine/chemokine cascade that is not commonly observed in cattle. Studies with other Chlamydia species have demonstrated that innate inflammatory pathways including inflammasome activation contribute to both pathogen clearance and pathology. Pattern recognition receptors (PRRs) activate these innate immune signalling pathways but are relatively poorly characterized in ruminants. We hypothesize that the ruminant hosts differ in their ability to innately sense C. abortus infection and activate the inflammasome. The main aims of this project were to: analyse PRR expression in innate immune cells; assess cytokine production from innate immune cells in response to C. abortus; investigate the role of PRRs in the induction of innate immune responses to C. abortus; and, conduct RNA-seq analysis on macrophages following infection with C. abortus to identify important immune signalling pathways. Ruminant oro-nasal turbinate cells, monocyte derived dendritic cells (MDDCs) and monocyte derived macrophages (MDMs) express the cell-surface PRRs TLR2 and TLR4 and also the intracellular PRRs NOD 1 and NLRP3. Oro-nasal turbinate cells produce CXCL8 late into the chlamydial developmental cycle independent of IL-1β. In contrast, ruminant MDMs and MDDCs secrete early IL-1β in response to C. abortus infection. In MDMs and MDDCs, live and UV-inactivated C. abortus induced TNF-α and CXCL8 but live infection was required for IL-1β secretion. Therefore, intracellular C. abortus multiplication is necessary to stimulate the IL-1β processing pathway within these cells. In order to determine PRR function, NOD1 and NLRP3 were knocked down in ruminant MDMs using siRNA. In both ovine and bovine MDMs, NOD1 was identified as a factor in C. abortus mediated IL-1β production. NLRP3 knockdown in bovine but not ovine MDMs also reduced IL-1β production, indicating species-specific differences in C. abortus recognition. The RNA-seq analysis of ruminant MDMs identified novel pathways of immune activation by C. abortus and potentially important species-specific differences. An improved understanding of the innate immune pathways activated in susceptible and resistant hosts following C. abortus infection will inform on disease pathogenesis and could contribute to novel chlamydial vaccine design.
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Goede, Dieuwke de. "Verbs in spoken sentence processing: unraveling the activation pattern of the matrix verb." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2006. http://irs.ub.rug.nl/ppn/298832666.
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Doede, Aubrey L. "Electromyographic Analysis of Trunk Muscle Activation During a Throwing Pattern Following Rotator Cuff Mobilization." Scholarship @ Claremont, 2010. http://scholarship.claremont.edu/cmc_theses/90.
Повний текст джерелаАнотація:
Correct muscular activation of the body segments during an overhand throw is achieved when movement originates in the larger and more proximal legs and trunk and moves sequentially to the smaller, distal segments of the shoulder and arm. This sequence permits angular velocity to transfer progressively through the throw as part of an open kinetic chain. The athlete can summate angular velocity and segmental forces only if he is able to create a separation between the body segments during the movement pattern, and this separation is thus essential to effective segmental sequencing for activation of the trunk muscles to occur separately from distal segment motion. Limited mobility of the shoulder and scapula during the kinematic sequence will limit the ability of that segment to receive and contribute to the angular velocity of its proximal neighbors and to apply its own muscle torque to the throwing implement. This may result in compensatory motion of the proximal muscle groups to meet the demands placed on the body. To establish a link between compensatory activation of the trunk muscles and mobility in the rotator cuff and to apply this relationship to the pattern of the overhand throw, activity in the latissimus dorsi and external oblique/quadratus lumborum muscles was measured using surface electromyography in 40 college-age participants during arm flexion and lateral shoulder rotation. Muscle activation was recorded both before and after mobilization of relevant throwing muscles through targeted functional exercise. Results showed no significant change but suggested a general decrease in the level of peak muscle activation after participants engaged shoulder exercises. This is indicative of a downward trend in compensatory trunk activation during the initiation of shoulder motion. An increase in overall trunk muscle activity was also observed after exercise, which may imply a simultaneous engagement of the proximal throwing muscles in response to shoulder motion.
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Lei, Andrea. "Inflammasome regulation and activation in the intestinal epithelium." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:6db34fe2-36ae-44f4-a4ac-2464a333c8f8.
Повний текст джерелаАнотація:
Microbiota colonisation of the intestinal tract makes it difficult for pattern recognition receptors (PRR) to discriminate between beneficial microbes and harmful pathogens. We aim to define the roles of cytosolic Nod-like receptors (NLR) in intestinal immunity and homeostasis. Upon activation, some NLR form inflammasomes that mediate the release of inflammatory cytokines and pyroptosis, an inflammatory form of cell death. NLR activation in the non-hematopoietic compartment was shown to be protective during acute intestinal infection. To identify the cell type responsible for this protection, we generated transgenic mice in which the key inflammasome adaptor molecule Asc is selectively ablated in intestinal epithelial cells (IEC) (AscΔVC) and observed that inflammasomes are important for controlling Citrobacter rodentium clearance in these mice. To further dissect the importance of pathogen clearance by IEC inflammasome, ex vivo cultures of primary IEC organoids were established. Thus far this system has revealed profound differences in inflammasome regulation between IEC organoids and bone marrow-derived macrophages (BMDM). This research will inform our understanding of cell type-specific regulation of inflammasomes.
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Fung, Joyce. "The muscle activation and reflex modulation pattern during locomotion in normal and spastic paretic subjects." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39327.
Повний текст джерелаАнотація:
The lower limb electromyographic (EMG) patterns of 5 normal and 8 spastic paretic subjects during walking were compared. A dynamic EMG profile index, proposed to quantify spastic locomotor dysfunction, was found to be homogeneously low in normal subjects and abnormally high in spastic subjects. In another study, the normally phase-dependent modulation of the soleus H-reflex during walking was found to be decreased or absent in 21 spastic paretic subjects, suggesting the possibility of defective reflex gating mechanisms. The conditioning effects of plantar cutaneomuscular stimulation were further examined in 10 normal and 10 spastic paretic subjects. The conditioned H-reflex was inhibited in a task and phase-dependent manner, such that the effects were most marked during early stance and swing, restoring a near normal modulation pattern during walking in the severely spastic subjects who showed no modulation previously. The possible underlying mechanisms and implications for rehabilitation are discussed.
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Munger, Emily LaRee. "Phenotypic Pattern of Astrocyte Activation in Response to Aging and Alzheimer's-Like Pathology in Chimpanzees." Kent State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1467887282.
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Geach, Timothy John. "Tolloid metalloproteases implicated in dorsal-ventral pattern and extra-cellular matrix activation in Xenopus laevis." Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1446246/.
Повний текст джерелаАнотація:
Tolloid (Tld) metalloproteases are zinc dependent extra-cellular endopeptidases that have numerous roles during embryonic development. All Tlds have a highly conserved N-terminal protease domain and an array of C terminal CUB and EGF-like domains thought to play a role in substrate interactions. In Xenopus laevis three members of the Tld family have been identified, BMP-1/Tld, Xolloid and Xolloid-related. All modulate dorsal-ventral patterning of the developing embryo by cleaving the dorsalising factor Chordin, preventing it from binding and inhibiting of the signalling molecule BMP-4. Biochemical studies of mammalian Tlds have identified a wide range of substrates, many involved in formation of the extra-cellular matrix. BMP-1/Tld is identical to pro-collagen C-proteinase, an enzyme that removes the C- terminal pro-peptide of procollagen types 1, 2 and 3, the N-terminal pro-peptide of procollagen type 11 and both the N- and C-terminal pro-peptides of procollagen type 5. It also activates lysyl-oxidase (lox), an enzyme that plays an essential role in collagen maturation. In addition, BMP-1 has been implicated in the proteolytic activation of biglycan, endorepellin, myostatin, osteoglycin and the a-3 and y-2 chains of Laminin-5. In this thesis I identify and describe the expression for Xenopus homologues of procollagen 3al, 5al, 5a2 and Hal, biglycan and a laminin ct-chain like gene. I have also identified three members of the lox family and characterise their role during early Xenopus development. In addition, using a domain deletion approach, I determine the C-terminal CUB domains of Xolloid that are required for cleavage of Chordin. Finally, I study the potential role of endodermin, which displays significant homology to ct-2 macroglobulin, as an inhibitor of Tld metalloproteases.
Книги з теми "Activation pattern"
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Altenmüller, Eckart. Music, the brain, and music learning: Mental representation and changing cortical activation patterns through learning. Narberth, PA: Gordon Institute for Music Learning, 1997.
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Shafi, Mouhsin M., and M. Brandon Westover. EEG Activation Methods. Edited by Donald L. Schomer and Fernando H. Lopes da Silva. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190228484.003.0010.
Повний текст джерелаАнотація:
Activation procedures are commonly employed to increase the diagnostic yield of electroencephalography (EEG) in patients with suspected epilepsy. This chapter reviews the effects and utility of hyperventilation, intermittent photic stimulation, and color/pattern stimulation on the EEG in patients with epilepsy and other neurological disorders. In theory, the greater the number of different activation methods used in EEG evaluation of an epilepsy patient, the greater the chance of obtaining abnormal findings. However, the specificity of these findings for epilepsy is uncertain. Furthermore, from a practical point of view, desirable activations are those methods that can be carried out easily and systematically, in a short time frame, with affordable equipment, without undesirable side effects for patients, and with reliable and predictive results. At this time, hyperventilation and intermittent photic stimulation are the most widely used activation methods and have an extensive body of literature supporting them.
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Segall, Liviu, and Adrian Covic. Immune-mediated tubulointerstitial nephritis. Edited by Adrian Covic. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199592548.003.0093_update_001.
Повний текст джерелаАнотація:
Immune-mediated tubulointerstitial nephritides (TINs) are generally encountered in the context of systemic or extrarenal autoimmune diseases, such as sarcoidosis, Sjögren syndrome, systemic lupus erythematosus, inflammatory bowel disease, TIN and uveitis (TINU) syndrome, and immunoglobulin G4-related disease. The pathogenesis of these TINs is complex and more or less unclear; it usually involves leucocyte activation, autoantibodies, immune complex deposition, complement activation, and release of inflammatory cytokines and growth factors. Tubulointerstitial inflammation most commonly has a chronic pattern, although acute forms of TIN may also occur. Furthermore, inflammation may be granulomatous (as in sarcoidosis or Crohn’s disease) or non-granulomatous. Immunofluorescence staining can sometimes reveal immune complex deposits and even antitubular basement membrane autoantibodies. Systemic immunosuppressive therapies are almost always required to prevent progression to irreversible interstitial fibrosis, tubular atrophy, and end-stage renal disease.
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Wiersinga, W. Joost, and Tom van der Poll. The host response to infection in the critically ill. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199600830.003.0303.
Повний текст джерелаАнотація:
Infection continues to be a leading cause of intensive care unit death. The host response to infection can be seen as a pattern recognition receptor (PRR)-mediated dysregulation of the immune system following pathogen invasion in which a careful balance between inflammatory and anti-inflammatory responses is vital. A measured and rapid response to microbial invasion is essential to health. The same immunological and coagulation systems that protect against localized infection can act to our disadvantage when these systems are activated systemically during generalized microbial infection. Toll-like receptors (TLR), the inflammasomes and other PRRs initiate the host response after recognition of pathogen-associated-molecular-patterns (PAMPs) or endogenous danger-associated-molecular-patterns (DAMPs). The systemic host response to infection will result in activation of coagulation, downregulation of physiological anticoagulant mechanisms, and inhibition of fibrinolysis. Further dissection of the role of host–pathogen interactions, the cytokine response, the coagulation cascade and their multidirectional interactions in sepsis should lead towards the development of new therapeutic approaches in the critically ill who are faced with infection.
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Geri, Guillaume, and Jean-Paul Mira. Host–pathogen interactions in the critically ill. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199600830.003.0306.
Повний текст джерелаАнотація:
Infection by a pathogenic micro-organism triggers a coordinated activation of both innate and adaptive immune responses. The innate immune response quickly triggers an antimicrobial response that will initiate development of a pathogen-specific, long-lasting adaptive immune response. Accurate recognition of microbial-associated molecular patterns by pattern-recognition receptors (PRRs) is the cornerstone of this immediate response. Most studied PRRs are Toll-like receptors (TLRs) and their kinase signalling cascades that activate nuclear transcription factors, and induce gene expression and cytokine production. Deficiencies or genetic variability in these different signalling pathways may lead to recurrent pyogenic infections and severe invasive diseases. After initial contact between the host and pathogen, numerous factors mediate the inflammatory response, as pro-inflammatory cytokines and chemokines. Apart from host genetic variability, pathogen diversity also influences the phenotypic features of various infectious diseases. Genomic analysis may assist in the development of targeted therapies or new therapeutic strategies based on both patient and microorganism genotype.
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Sampson, Heidi. Characterization of Drosophila nuclear receptor interactions and activation patterns. 2006.
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Voll, Reinhard E., and Barbara M. Bröker. Innate vs acquired immunity. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0048.
Повний текст джерелаАнотація:
The innate and the adaptive immune system efficiently cooperate to protect us from infections. The ancient innate immune system, dating back to the first multicellular organisms, utilizes phagocytic cells, soluble antimicrobial peptides, and the complement system for an immediate line of defence against pathogens. Using a limited number of germline-encoded pattern recognition receptors including the Toll-like, RIG-1-like, and NOD-like receptors, the innate immune system recognizes so-called pathogen-associated molecular patterns (PAMPs). PAMPs are specific for groups of related microorganisms and represent highly conserved, mostly non-protein molecules essential for the pathogens' life cycles. Hence, escape mutants strongly reduce the pathogen's fitness. An important task of the innate immune system is to distinguish between harmless antigens and potentially dangerous pathogens. Ideally, innate immune cells should activate the adaptive immune cells only in the case of invading pathogens. The evolutionarily rather new adaptive immune system, which can be found in jawed fish and higher vertebrates, needs several days to mount an efficient response upon its first encounter with a certain pathogen. As soon as antigen-specific lymphocyte clones have been expanded, they powerfully fight the pathogen. Importantly, memory lymphocytes can often protect us from reinfections. During the development of T and B lymphocytes, many millions of different receptors are generated by somatic recombination and hypermutation of gene segments making up the antigen receptors. This process carries the inherent risk of autoimmunity, causing most inflammatory rheumatic diseases. In contrast, inadequate activation of the innate immune system, especially activation of the inflammasomes, may cause autoinflammatory syndromes.
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Covassin, Naima, and Virend K. Somers. The cardiovascular system during sleep. Edited by Guido Grassi. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0028.
Повний текст джерелаАнотація:
The majority of molecular, physiological, and behavioural processes undergo substantial variations across a 24 h period. The health implications of such fluctuations, whether they are expressions of an intrinsic circadian rhythmicity or are secondary to changes in physical activity, posture, and/or sleep, are increasingly recognized. Similar to other biological functions, the cardiovascular system exhibits a prominent day–night profile, with profound haemodynamic, autonomic, and hormonal oscillations occurring during the sleep period. These time-dependent and sleep stage-dependent patterns of function have important clinical significance. The cardiovascular downregulation achieved throughout the night while asleep may be restorative and protective against adverse events, while the morning physiological activation coincident with awakening facilitates resumption of daytime activities. Nevertheless, rather than beneficial, these activity configurations may be pathogenic in individuals with a vulnerable substrate and may favour onset and progression of cardiovascular diseases. Cardiovascular complications may also arise as a consequence of abnormal day–night periodicity and disturbed sleep quantity and quality. Hence, consideration of the diurnal pattern of cardiovascular activity is critical in the clinical setting.
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Bind, Rebecca Hannah, and Carmine M. Pariante. Psychoneuroimmunology of Post-Traumatic Stress Disorder. Edited by Charles B. Nemeroff and Charles R. Marmar. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190259440.003.0021.
Повний текст джерелаАнотація:
This chapter reviews the evidence linking post-traumatic stress disorder (PTSD) with changes in immune function. The chapter starts with a brief explanation of the components of the immune system, including cytokines, and of the mechanisms linking psychological and psychiatric phenomena with changes in immune function (i.e., psychoneuroimmunology). Specific studies on PTSD are then described, including the potential neurobiological and health consequences of these immune changes and, finally, the effects of PTSD treatment on both symptomology and the immune system. While there is a consistent pattern of findings indicating increased immune activation in this condition, there is a paucity of research on the immunological correlates of PTSD, especially compared with the large number of immunological studies on depression and other psychiatric disorders.
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Borsboom, Denny. Mental disorders, network models, and dynamical systems. Edited by Kenneth S. Kendler and Josef Parnas. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780198796022.003.0011.
Повний текст джерелаАнотація:
Network approaches have been proposed as an alternative way of thinking about relations between symptoms of mental disorders. Unlike traditional psychometric approaches, network models view these associations as the result of direct interactions between symptoms. Disorders are defined as alternative stable states of a network due to increased connectivity between symptoms. This increased connectivity creates a pattern of reinforcement, so the system can get stuck in a state of prolonged activation. Mental health is defined as the stable state of a weakly connected network. Although symptomatology may be temporarily increased in a healthy network (e.g., due to adverse life events), as the influence of a shock wanes the network will spontaneously return to its healthy state. Strongly connected networks, however, may transition into disordered states upon similar external shocks, and may not naturally recover. Thus, the proposed definitions yield plausible conceptualizations of resilience and vulnerability.
Частини книг з теми "Activation pattern"
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Eggersglüß, Stephan, and Rolf Drechsler. "Dynamic Clause Activation." In High Quality Test Pattern Generation and Boolean Satisfiability, 73–106. Boston, MA: Springer US, 2012. http://dx.doi.org/10.1007/978-1-4419-9976-4_5.
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Shen, Yan, Liao Zhang, Shuqin Lou, and Zhongli Wang. "Dense Activation Network for Image Denoising." In Pattern Recognition and Computer Vision, 79–90. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-31723-2_7.
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He, Xiangteng, and Yuxin Peng. "Multi-attention Guided Activation Propagation in CNNs." In Pattern Recognition and Computer Vision, 16–27. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-03335-4_2.
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Shen, Yeqing, Huimin Ma, Xiaowen Zhang, Tianyu Hu, and Yuhan Dong. "Distance-Based Class Activation Map for Metric Learning." In Pattern Recognition and Computer Vision, 336–47. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-88013-2_28.
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Li, Dandan, and Yuan Zhou. "Soft-Root-Sign: A New Bounded Neural Activation Function." In Pattern Recognition and Computer Vision, 310–19. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60636-7_26.
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Cantador, Iván, and José R. Dorronsoro. "Parallel Perceptrons, Activation Margins and Imbalanced Training Set Pruning." In Pattern Recognition and Image Analysis, 43–50. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/11492542_6.
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Wang, Lijuan, Suguo Zhu, Zhihao Li, and Zhenying Fang. "Complementary Temporal Classification Activation Maps in Temporal Action Localization." In Pattern Recognition and Computer Vision, 373–84. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-88007-1_31.
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Doherty, John, Bryan Gardiner, Emmett Kerr, Nazmul Siddique, and Sunilkumar S. Manvi. "Comparative Study of Activation Functions and Their Impact on the YOLOv5 Object Detection Model." In Pattern Recognition and Artificial Intelligence, 40–52. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-09282-4_4.
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Huesmann, Karim, Luis Garcia Rodriguez, Lars Linsen, and Benjamin Risse. "The Impact of Activation Sparsity on Overfitting in Convolutional Neural Networks." In Pattern Recognition. ICPR International Workshops and Challenges, 130–45. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-68796-0_10.
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Sulaiman, Maisarah, Aizreena Azaman, and Azli Yahya. "Influence of Individual Physical Activity on EMG Muscle Activation Pattern." In Enhancing Health and Sports Performance by Design, 215–22. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-3270-2_24.
Повний текст джерелаТези доповідей конференцій з теми "Activation pattern"
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Koller, Miklos, and Tamas Roska. "Activation light pattern helps detection." In 2014 14th International Workshop on Cellular Nanoscale Networks and their Applications (CNNA). IEEE, 2014. http://dx.doi.org/10.1109/cnna.2014.6888595.
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Dai, Yimian, Stefan Oehmcke, Fabian Gieseke, Yiquan Wu, and Kobus Barnard. "Attention as Activation." In 2020 25th International Conference on Pattern Recognition (ICPR). IEEE, 2021. http://dx.doi.org/10.1109/icpr48806.2021.9413020.
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Manessi, Franco, and Alessandro Rozza. "Learning Combinations of Activation Functions." In 2018 24th International Conference on Pattern Recognition (ICPR). IEEE, 2018. http://dx.doi.org/10.1109/icpr.2018.8545362.
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Farhadi, Farnoush, Vahid Nia, and Andrea Lodi. "Activation Adaptation in Neural Networks." In 9th International Conference on Pattern Recognition Applications and Methods. SCITEPRESS - Science and Technology Publications, 2020. http://dx.doi.org/10.5220/0009175102490257.
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Dhivya, P., and A. Bazilabanu. "Complex Pattern Recognition using Feedback Algebraic Activation Function." In 2021 2nd International Conference on Communication, Computing and Industry 4.0 (C2I4). IEEE, 2021. http://dx.doi.org/10.1109/c2i454156.2021.9689426.
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Foldy-Porto, Timothy, Yeshwanth Venkatesha, and Priyadarshini Panda. "Activation Density Driven Efficient Pruning in Training." In 2020 25th International Conference on Pattern Recognition (ICPR). IEEE, 2021. http://dx.doi.org/10.1109/icpr48806.2021.9413182.
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Gui, Cunbin, and Jiani Hu. "Unsupervised Domain Adaptation by regularizing Softmax Activation." In 2018 24th International Conference on Pattern Recognition (ICPR). IEEE, 2018. http://dx.doi.org/10.1109/icpr.2018.8545224.
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Ng, Bernard, Rafeef Abugharbieh, and Ghassan Hamarneh. "Group MRF for fMRI activation detection." In 2010 IEEE Conference on Computer Vision and Pattern Recognition (CVPR). IEEE, 2010. http://dx.doi.org/10.1109/cvpr.2010.5540026.
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Ma, Ningning, Xiangyu Zhang, Ming Liu, and Jian Sun. "Activate or Not: Learning Customized Activation." In 2021 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR). IEEE, 2021. http://dx.doi.org/10.1109/cvpr46437.2021.00794.
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Esquivel, Julio Zamora, Jesus Adan Cruz Vargas, and Paulo Lopez-Meyer. "Fractional Adaptation of Activation Functions In Neural Networks." In 2020 25th International Conference on Pattern Recognition (ICPR). IEEE, 2021. http://dx.doi.org/10.1109/icpr48806.2021.9413338.
Повний текст джерелаЗвіти організацій з теми "Activation pattern"
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Sessa, Guido, and Gregory Martin. role of FLS3 and BSK830 in pattern-triggered immunity in tomato. United States Department of Agriculture, January 2016. http://dx.doi.org/10.32747/2016.7604270.bard.
Повний текст джерелаАнотація:
Pattern-recognition receptors (PRRs) located on the plant cell surface initiate immune responses by perceiving conserved pathogen molecules known as pathogen-associated molecular patterns (PAMPs). PRRs typically function in multiprotein complexes that include transmembrane and cytoplasmickinases and contribute to the initiation and signaling of pattern-triggered immunity (PTI). An important challenge is to identify molecular components of PRR complexes and downstream signaling pathways, and to understand the molecular mechanisms that mediate their function. In research activities supported by BARD-4931, we studied the role of the FLAGELLIN SENSING 3 (FLS3) PRR in the response of tomato leaves to flagellin-derivedPAMPs and PTI. In addition, we investigated molecular properties of the tomato brassinosteroid signaling kinase 830 (BSK830) that physically interacts with FLS3 and is a candidate for acting in the FLS3 signaling pathway. Our investigation refers to the proposal original objectives that were to: 1) Investigate the role of FLS3 and its interacting proteins in PTI; 2) Investigate the role of BSK830 in PTI; 3) Examine molecular and phosphorylation dynamics of the FLS3-BSK830 interaction; 4) Examine the possible interaction of FLS3 and BSK830 with Pstand Xcveffectors. We used CRISPR/Cas9 techniques to develop plants carrying single or combined mutations in the FLS3 gene and in the paralogsFLS2.1 and FLS2.2 genes, which encode the receptor FLAGELLIN SENSING2 (FLS2), and analyzed their function in PTI. Domain swapping analysis of the FLS2 and FLS3 receptors revealed domains of the proteins responsible for PAMP detection and for the different ROS response initiated by flgII-28/FLS3 as compared to flg22/FLS2. In addition, in vitro kinase assays and point mutations analysis identified FLS2 and FLS3 domains required for kinase activity and ATP binding. In research activities on tomato BSK830, we found that it interacts with PRRs and with the co-receptor SERK3A and PAMP treatment affects part of these interactions. CRISPR/Cas9 bsk830 mutant plants displayed enhanced pathogen susceptibility and reduced ROS production upon PAMP treatment. In addition, BSK830 interacted with 8 Xanthomonastype III secreted effectors. Follow up analysis revealed that among these effectors XopAE is part of an operon, is translocated into plant cells, and displays E3 ubiquitinligase activity. Our investigation was also extended to other Arabidopsis and tomato BSK family members. Arabidopsis BSK5 localized to the plant cell periphery, interacted with receptor-like kinases, and it was phosphorylatedin vitro by the PEPR1 and EFRPRRs. bsk5 mutant plants displayed enhanced susceptibility to pathogens and were impaired in several, but not all, PAMP-induced responses. Conversely, BSK5 overexpression conferred enhanced disease resistance and caused stronger PTI responses. Genetic complementation suggested that proper localization, kinase activity, and phosphorylation by PRRs are critical for BSK5 function. BSK7 and BSK8 specifically interacted with the FLS2 PRR, their respective mutant plants were more susceptible to B. cinereaand displayed reduced flg22-induced responses. The tomato BSK Mai1 was found to interact with the M3KMAPKKK, which is involved in activation of cell death associated with effector-triggered immunity. Silencing of Mai1 in N. benthamianaplants compromised cell death induced by a specific class of immune receptors. In addition, co-expression of Mai1 and M3Kin leaves enhanced MAPKphosphorylation and cell death, suggesting that Mai1 acts as a molecular link between pathogen recognition and MAPK signaling. Finally, We identified the PP2C phosphatase Pic1 that acts as a negative regulator of PTI by interacting with and dephosphorylating the receptor-like cytoplasmickinase Pti1, which is a positive regulator of plant immunity. The results of this investigation shed new light on the molecular characteristics and interactions of components of the immune system of crop plants providing new knowledge and tools for development of novel strategies for disease control.
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Robledo-Castro, Carolina, Gisella Bonilla-Santos, and Piedad Rocío Lerma-Castaño. Computer-based cognitive training programs: effects on executive functions in children with attention deficit hyperactivity disorder (ADHD). INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, October 2022. http://dx.doi.org/10.37766/inplasy2022.10.0046.
Повний текст джерелаАнотація:
Review question / Objective: This systematic review aimed to synthesize the existing literature reporting the effects of computer-based cognitive training on the executive functions of children with ADHD. Condition being studied: Attention Deficit Hyperactivity Disorder (ADHD) is the most common neurodevelopmental disorder diagnosed in childhood, characterized by a persistent pattern of inattention, hyperactivity, and impulsivity. Today it is recognized that ADHD is associated with an alteration in the volume and level of activation in prefrontal areas related to executive functions. Based on these clinical findings, some authors suggest that ADHD is not a disorder of primary attention origin but instead responds to an alteration in the synaptic circuits of some brain areas, including the prefrontal neocortex, areas involved in cognitive regulation and control, and processes known as executive functions.
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Sessa, Guido, and Gregory B. Martin. molecular link from PAMP perception to a MAPK cascade associated with tomato disease resistance. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7597918.bard.
Повний текст джерелаАнотація:
The research problem: The detection of pathogen-associated molecular patterns (PAMPs) by plant pattern recognition receptors (PRRs) is a key mechanism by which plants activate an effective immune response against pathogen attack. MAPK cascades are important signaling components downstream of PRRs that transduce the PAMP signal to activate various defense responses. Preliminary experiments suggested that the receptor-like cytoplasmickinase (RLCK) Mai5 plays a positive role in pattern-triggered immunity (PTI) and interacts with the MAPKKK M3Kε. We thus hypothesized that Mai5, as other RLCKs, functions as a component PRR complexes and acts as a molecular link between PAMP perception and activation of MAPK cascades. Original goals: The central goal of this research was to investigate the molecular mechanisms by which Mai5 and M3Kε regulate plant immunity. Specific objectives were to: 1. Determine the spectrum of PAMPs whose perception is transmitted by M3Kε; 2. Identify plant proteins that act downstream of M3Kε to mediate PTI; 3. Investigate how and where Mai5 interacts with M3Kε in the plant cell; 4. Examine the mechanism by which Mai5 contributes to PTI. Changes in research directions: We did not find convincing evidence for the involvement of M3Kε in PTI signaling and substituted objectives 1 and 3 with research activities aimed at the analysis of transcriptomic profiles of tomato plants during the onset of plant immunity, isolation of the novel tomato PRR FLS3, and investigation of the involvement of the RLCKBSKs in PTI. Main achievements during this research program are in the following major areas: 1. Functional characterization of Mai5. The function of Mai5 in PTI signaling was demonstrated by testing the effect of silencing the Mai5 gene by virus-induced gene silencing (VIGS) experiments and in cell death assays. Domains of Mai5 that interact with MAPKKKs and subcellular localization of Mai5 were analyzed in detail. 2. Analysis of transcriptional profiles during the tomato immune responses to Pseudomonas syringae (Pombo et al., 2014). We identified tomato genes whose expression is induced specifically in PTI or in effector-triggered immunity (ETI). Thirty ETI-specific genes were examined by VIGS for their involvement in immunity and the MAPKKK EPK1, was found to be required for ETI. 3. Dissection of MAP kinase cascades downstream of M3Kε (Oh et al., 2013; Teper et al., 2015). We identified genes that encode positive (SGT and EDS1) and negative (WRKY1 and WRKY2) regulators of the ETI-associated cell death mediated by M3Kε. In addition, the MKK2 MAPKK, which acts downstream of M3Kε, was found to interact with the MPK3 MAPK and specific MPK3 amino acids involved interaction were identified and found to be required for induction of cell death. We also identified 5 type III effectors of the bacterial pathogen Xanthomonaseuvesicatoria that inhibited cell death induced by components of ETI-associated MAP kinase cascades. 4. Isolation of the tomato PRR FLS3 (Hind et al., submitted). FLS3, a novel PRR of the LRR-RLK family that specifically recognizes the flagellinepitope flgII-28 was isolated. FLS3 was shown to bind flgII-28, to require kinase activity for function, to act in concert with BAK1, and to enhance disease resistance to Pseudomonas syringae. 5. Functional analysis of RLCKs of the brassinosteroid signaling kinase (BSK) family.Arabidopsis and tomato BSKs were found to interact with PRRs. In addition, certain ArabidospsisBSK mutants were found to be impaired in PAMP-induced resistance to Pseudomonas syringae. Scientific and agricultural significance: Our research activities discovered and characterized new molecular components of signaling pathways mediating recognition of invading pathogens and activation of immune responses against them. Increased understanding of molecular mechanisms of immunity will allow them to be manipulated by both molecular breeding and genetic engineering to produce plants with enhanced natural defense against disease.
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Chejanovsky, Nor, Diana Cox-Foster, Victoria Soroker, and Ron Ophir. Honeybee modulation of infection with the Israeli acute paralysis virus, in asymptomatic, acutely infected and CCD colonies. United States Department of Agriculture, December 2013. http://dx.doi.org/10.32747/2013.7594392.bard.
Повний текст джерелаАнотація:
Honey bee (Apis mellifera) colony losses pose a severe risk to the food chain. The IAPV (Israeli acute paralysis virus) was correlated with CCD, a particular case of colony collapse. Honey bees severely infected with IAPV show shivering wings that progress to paralysis and subsequent death. Bee viruses, including IAPV, are widely present in honey bee colonies but often there are no pathological symptoms. Infestation of the beehive with Varroa mites or exposure to stress factors leads to significant increase in viral titers and fatal infections. We hypothesized that the honey bee is regulating/controlling IAPV and viral infections in asymptomatic infections and this control is broken through "stress" leading to acute infections and/or CCD. Our aims were: 1. To discover genetic changes in IAPV that may affect tissue tropism in the host, and/or virus infectivity and pathogenicity. 2. To elucidate mechanisms used by the host to regulate/ manage the IAPV-infection in vivo and in vitro. To achieve the above objectives we first studied stress-induced virus activation. Our data indicated that some pesticides, including myclobutanil, chlorothalonil and fluvalinate, result in amplified viral titers when bees are exposed at sub lethal levels by a single feeding. Analysis of the level of immune-related bee genes indicated that CCD-colonies exhibit altered and weaker immune responses than healthy colonies. Given the important role of viral RNA interference (RNAi) in combating viral infections we investigated if CCD-colonies were able to elicit this particular antiviral response. Deep-sequencing analysis of samples from CCD-colonies from US and Israel revealed high frequency of small interfering RNAs (siRNA) perfectly matching IAPV, Kashmir bee virus and Deformed wing virus genomes. Israeli colonies showed high titers of IAPV and a conserved RNAi pattern of targeting the viral genome .Our findings were further supported by analysis of samples from colonies experimentally infected with IAPV. Following for the first time the dynamics of IAPV infection in a group of CCD colonies that we rescued from collapse, we found that IAPV conserves its potential to act as one lethal, infectious factor and that its continuous replication in CCD colonies deeply affects their health and survival. Ours is the first report on the dominant role of IAPV in CCD-colonies outside from the US under natural conditions. We concluded that CCD-colonies do exhibit a regular siRNA response that is specific against predominant viruses associated with colony losses and other immune pathways may account for their weak immune response towards virus infection. Our findings: 1. Reveal that preventive measures should be taken by the beekeepers to avoid insecticide-based stress induction of viral infections as well as to manage CCD colonies as a source of highly infectious viruses such as IAPV. 2. Contribute to identify honey bee mechanisms involved in managing viral infections.
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Heifetz, Yael, and Michael Bender. Success and failure in insect fertilization and reproduction - the role of the female accessory glands. United States Department of Agriculture, December 2006. http://dx.doi.org/10.32747/2006.7695586.bard.
Повний текст джерелаАнотація:
The research problem. Understanding of insect reproduction has been critical to the design of insect pest control strategies including disruptions of mate-finding, courtship and sperm transfer by male insects. It is well known that males transfer proteins to females during mating that profoundly affect female reproductive physiology, but little is known about the molecular basis of female mating response and no attempts have yet been made to interfere with female post-mating responses that directly bear on the efficacy of fertilization. The female reproductive tract provides a crucial environment for the events of fertilization yet thus far those events and the role of the female tract in influencing them are poorly understood. For this project, we have chosen to focus on the lower reproductive tract because it is the site of two processes critical to reproduction: sperm management (storage, maintenance, and release from storage) and fertilization. E,fforts during this project period centered on the elucidation of mating responses in the female lower reproductive tract The central goals of this project were: 1. To identify mating-responsive genes in the female lower reproductive tract using DNA microarray technology. 2. In parallel, to identify mating-responsive genes in these tissues using proteomic assays (2D gels and LC-MS/MS techniques). 3. To integrate proteomic and genomic analyses of reproductive tract gene expression to identify significant genes for functional analysis. Our main achievements were: 1. Identification of mating-responsive genes in the female lower reproductive tract. We identified 539 mating-responsive genes using genomic and proteomic approaches. This analysis revealed a shift from gene silencing to gene activation soon after mating and a peak in differential gene expression at 6 hours post-mating. In addition, comparison of the two datasets revealed an expression pattern consistent with the model that important reproductive proteins are pre-programmed for synthesis prior to mating. This work was published in Mack et al. (2006). Validation experiments using real-time PCR techniques suggest that microarray assays provide a conservativestimate of the true transcriptional activity in reproductive tissues. 2.lntegration of proteomics and genomics data sets. We compared the expression profiles from DNA microarray data with the proteins identified in our proteomic experiments. Although comparing the two data sets poses analyical challenges, it provides a more complete view of gene expression as well as insights into how specific genes may be regulated. This work was published in Mack et al. (2006). 3. Development of primary reproductive tract cell cultures. We developed primary cell cultures of dispersed reproductive tract cell types and determined conditions for organ culture of the entire reproductive tract. This work will allow us to rapidly screen mating-responsive genes for a variety of reproductive-tract specifi c functions. Scientific and agricultural significance. Together, these studies have defined the genetic response to mating in a part of the female reproductive tract that is critical for successful fertllization and have identified alarge set of mating-responsive genes. This work is the first to combine both genomic and proteomic approaches in determining female mating response in these tissues and has provided important insights into insect reproductive behavior.
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Eldar, Avigdor, and Donald L. Evans. Streptococcus iniae Infections in Trout and Tilapia: Host-Pathogen Interactions, the Immune Response Toward the Pathogen and Vaccine Formulation. United States Department of Agriculture, December 2000. http://dx.doi.org/10.32747/2000.7575286.bard.
Повний текст джерелаАнотація:
In Israel and in the U.S., Streptococcus iniae is responsible for considerable losses in various fish species. Poor understanding of its virulence factors and limited know-how-to of vaccine formulation and administration are the main reasons for the limited efficacy of vaccines. Our strategy was that in order to Improve control measures, both aspects should be equally addressed. Our proposal included the following objectives: (i) construction of host-pathogen interaction models; (ii) characterization of virulence factors and immunodominant antigens, with assessment of their relative importance in terms of protection and (iii) genetic identification of virulence factors and genes, with evaluation of the protective effect of recombinant proteins. We have shown that two different serotypes are involved. Their capsular polysaccharides (CPS) were characterized, and proved to play an important role in immune evasion and in other consequences of the infection. This is an innovative finding in fish bacteriology and resembles what, in other fields, has become apparent in the recent years: S. iniae alters surface antigens. By so doing, the pathogen escapes immune destruction. Immunological assays (agar-gel immunodiffusion and antibody titers) confirmed that only limited cross recognition between the two types occurs and that capsular polysaccharides are immunodominant. Vaccination with purified CPS (as an acellular vaccine) results in protection. In vitro and ex-vivo models have allowed us to unravel additional insights of the host-pathogen interactions. S. iniae 173 (type II) produced DNA fragmentation of TMB-8 cells characteristic of cellular necrosis; the same isolate also prevented the development of apoptosis in NCC. This was determined by finding reduced expression of phosphotidylserine (PS) on the outer membrane leaflet of NCC. NCC treated with this isolate had very high levels of cellular necrosis compared to all other isolates. This cellular pathology was confirmed by observing reduced DNA laddering in these same treated cells. Transmission EM also showed characteristic necrotic cellular changes in treated cells. To determine if the (in vitro) PCD/apoptosis protective effects of #173 correlated with any in vivo activity, tilapia were injected IV with #173 and #164 (an Israeli type I strain). Following injection, purified NCC were tested (in vitro) for cytotoxicity against HL-60 target cells. Four significant observations were made : (i) fish injected with #173 had 100-400% increased cytotoxicity compared to #164 (ii) in vivo activation occurred within 5 minutes of injection; (iii) activation occurred only within the peripheral blood compartment; and (iv) the isolate that protected NCC from apoptosis in vitro caused in vivo activation of cytotoxicity. The levels of in vivo cytotoxicity responses are associated with certain pathogens (pathogen associated molecular patterns/PAMP) and with the tissue of origin of NCC. NCC from different tissue (i.e. PBL, anterior kidney, spleen) exist in different states of differentiation. Random amplified polymorphic DNA (RAPD) analysis revealed the "adaptation" of the bacterium to the vaccinated environment, suggesting a "Darwinian-like" evolution of any bacterium. Due to the selective pressure which has occurred in the vaccinated environment, type II strains, able to evade the protective response elicited by the vaccine, have evolved from type I strains. The increased virulence through the appropriation of a novel antigenic composition conforms with pathogenic mechanisms described for other streptococci. Vaccine efficacy was improved: water-in-oil formulations were found effective in inducing protection that lasted for a period of (at least) 6 months. Protection was evaluated by functional tests - the protective effect, and immunological parameters - elicitation of T- and B-cells proliferation. Vaccinated fish were found to be resistant to the disease for (at least) six months; protection was accompanied by activation of the cellular and the humoral branches.
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Markova, Oksana, Serhiy Semerikov та Maiia Popel. СoCalc as a Learning Tool for Neural Network Simulation in the Special Course “Foundations of Mathematic Informatics”. Sun SITE Central Europe, травень 2018. http://dx.doi.org/10.31812/0564/2250.
Повний текст джерелаАнотація:
The role of neural network modeling in the learning сontent of special course “Foundations of Mathematic Informatics” was discussed. The course was developed for the students of technical universities – future IT-specialists and directed to breaking the gap between theoretic computer science and it’s applied applications: software, system and computing engineering. CoCalc was justified as a learning tool of mathematical informatics in general and neural network modeling in particular. The elements of technique of using CoCalc at studying topic “Neural network and pattern recognition” of the special course “Foundations of Mathematic Informatics” are shown. The program code was presented in a CofeeScript language, which implements the basic components of artificial neural network: neurons, synaptic connections, functions of activations (tangential, sigmoid, stepped) and their derivatives, methods of calculating the network`s weights, etc. The features of the Kolmogorov–Arnold representation theorem application were discussed for determination the architecture of multilayer neural networks. The implementation of the disjunctive logical element and approximation of an arbitrary function using a three-layer neural network were given as an examples. According to the simulation results, a conclusion was made as for the limits of the use of constructed networks, in which they retain their adequacy. The framework topics of individual research of the artificial neural networks is proposed.
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Fromm, A., Avihai Danon, and Jian-Kang Zhu. Genes Controlling Calcium-Enhanced Tolerance to Salinity in Plants. United States Department of Agriculture, March 2003. http://dx.doi.org/10.32747/2003.7585201.bard.
Повний текст джерелаАнотація:
The specific objectives of the proposed research were to identify, clone and characterize downstream cellular target(s) of SOS3 in Arabidopsis thaliana, to analyze the Ca2+-binding characteristics of SOS3 and the sos3-1 mutant and their interactions with SOS3 cellular targets to analyze the SOS3 cell-specific expression patterns, and its subcellular localization, and to assess the in vivo role of SOS3 target protein(s) in plant tolerance to salinity stress. In the course of the study, in view of recent opportunities in identifying Ca2+ - responsive genes using microarrays, the group at Weizmann has moved into identifying Ca2+-responsive stress genes by using a combination of aqeuorin-based measurements of cytosolic Ca and analysis by DNA microarrays of early Ca-responsive genes at the whole genome level. Analysis of SOS3 (University of Arizona) revealed its expression in both roots and shoots. However, the expression of this gene is not induced by stress. This is reminiscent of other stress proteins that are regulated by post-transcriptional mechanisms such as the activation by second messengers like Ca. Further analysis of the expression of the gene using promoter - GUS fusions revealed expression in lateral root primordial. Studies at the Weizmann Institute identified a large number of genes whose expression is up-regulated by a specific cytosolic Ca burst evoked by CaM antagonists. Fewer genes were found to be down-regulated by the Ca burst. Among the up-regulated genes many are associated with early stress responses. Moreover, this study revealed a large number of newly identified Ca-responsive genes. These genes could be useful to investigate yet unknown Ca-responsive gene networks involved in plant response to stress.
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Carpita, Nicholas C., Ruth Ben-Arie, and Amnon Lers. Pectin Cross-Linking Dynamics and Wall Softening during Fruit Ripening. United States Department of Agriculture, July 2002. http://dx.doi.org/10.32747/2002.7585197.bard.
Повний текст джерелаАнотація:
Our study was designed to elucidate the chemical determinants of pectin cross-linking in developing fruits of apple and peach and to evaluate the role of breakage cross-linkages in swelling, softening, and cell separation during the ripening. Peaches cell walls soften and swell considerably during the ripening, whereas apples fruit cells maintain wall firmness but cells separate during late stages of ripening. We used a "double-reduction" technique to show that levels of non-methyl esters of polyuronic acid molecules were constant during the development and ripening and decreased only in overripe fruit. In peach, methyl and non-methyl esters increased during the development and decreased markedly during the ripening. Non-methyl ester linkages in both fruit decreased accompanied fruit softening. The identity of the second component of the linkage and its definitive role in the fruit softening remain elusive. In preliminary examination of isolated apples cell walls, we found that phenolic compounds accumulate early in wall development but decrease markedly during ripening. Quantitative texture analysis was used to correlate with changes to wall chemistry from the fresh-picked ripe stage to the stage during storage when the cell separation occurs. Cell wall composition is similar in all cultivars, with arabinose as the principal neutral sugar. Extensive de-branching of these highly branched arabinans pre-stages softening and cell-cell separation during over-ripening of apple. The longer 5-arabinans remain attached to the major pectic polymer rhamnogalacturonan I (RG I) backbone. The degree of RG I branching, as judged from the ratios of 2-Rha:2,4-Rha, also decreases, specially after an extensive arabinan de-branching. Loss of the 4-Rham linkages correlated strongly with the softening of the fruit. Loss of the monomer or polymer linked to the RG I produce directly or indirectly the softening of the fruit. This result will help to understand the fruit softening and to have better control of the textural changes in fruit during the ripening and especially during the storage. 'Wooliness', an undesirable mealy texture that is induced during chilling of some peach cultivars, greatly reduces the fruit storage possibilities. In order to examine the hypothesis that the basis for this disorder is related to abnormality in the cell wall softening process we have carried out a comparative analysis using the resistant cultivar, Sunsnow, and a sensitive one, Hermosa. We investigated the activity of several pectin- and glycan-modifying enzymes and the expression of their genes during ripening, chilling, and subsequent shelf-life. The changes in carbohydrate status and in methyl vs. non-methyl uronate ester levels in the walls of these cultivars were examined as well to provide a basis for comparison of the relevant gene expression that may impact appearance of the wooly character. The activities of the specific polygalacturonase (PGase) and a CMC-cellulase activities are significantly elevated in walls of peaches that have become wooly. Cellulase activities correlated well with increased level of the transcript, but differential expression of PGase did not correspond with the observed pattern of mRNA accumulation. When expression of ethylene biosynthesis related genes was followed no significant differences in ACC synthase gene expression was observed in the wooly fruit while the normal activation of the ACC oxidase was partially repressed in the Hermosa wooly fruits. Normal ripening-related loss of the uronic acid-rich polymers was stalled in the wooly Hermosa inconsistent with the observed elevation in a specific PGase activity but consistent with PG gene expression. In general, analysis of the level of total esterification, degree of methyl esterification and level of non-methyl esters did not reveal any major alterations between the different fruit varieties or between normal and abnormal ripening. Some decrease in the level of uronic acids methyl esterification was observed for both Hermosa and Sunsnow undergoing ripening following storage at low temperature but not in fruits ripening after harvest. Our results support a role for imbalanced cell wall degradation as a basis for the chilling disorder. While these results do not support a role for the imbalance between PG and pectin methyl esterase (PME) activities as the basis for the disorder they suggest a possible role for imbalance between cellulose and other cell wall polymer degradation during the softening process.
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Prusky, Dov, Nancy P. Keller, and Amir Sherman. global regulation of mycotoxin accumulation during pathogenicity of Penicillium expansum in postharvest fruits. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7600012.bard.
Повний текст джерелаАнотація:
Background to the topic- Penicilliumas a postharvest pathogen and producer of the mycotoxin PAT. Penicilliumspp. are destructive phytopathogens, capable of causing decay in many deciduous fruits, during postharvest handling and storage; and the resulting losses can amount to 10% of the stored produce and the accumulation of large amounts of the mycotoxinpatulin. The overall goal of this proposal is to identify critical host and pathogen factors that modulate P. expansummycotoxin genes and pathways which are required for PAT production and virulence. Our preliminary results indicated that gluconic acid are strongly affecting patulin accumulation during colonization. P. expansumacidifies apple fruit tissue during colonization in part through secretion of gluconic acid (GLA). Several publications suggested that GLA accumulation is an essential factor in P. expansumpathogenicity. Furthermore, down regulation of GOX2 significantly reduced PAT accumulation and pathogenicity. PAT is a polyketide and its biosynthesis pathway includes a 15-gene cluster. LaeA is a global regulator of mycotoxin synthesis. It is now known that patulin synthesis might be subjected to LaeA and sometimes by environmental sensing global regulatory factors including the carbon catabolite repressor CreA as well as the pH regulator factor PacC and nitrogen regulator AreA. The mechanisms by which LaeA regulates patulin synthesis was not fully known and was part of our work. Furthermore, the regulatory system that controls gene expression in accordance with ambient pH was also included in our work. PacC protein is in an inactive conformation and is unable to bind to the promoter sites of the target genes; however, under alkaline growth conditions activated PacC acts as both an activator of alkaline-expressed genes and a repressor of acid-expressed genes. The aims of the project- This project aims to provide new insights on the roles of LaeA and PacC and their signaling pathways that lead to GLA and PAT biosynthesis and pathogenicity on the host. Specifically, our specific aims were: i) To elucidate the mechanism of pH-controlled regulation of GLA and PAT, and their contribution to pathogenesis of P. expansum. We are interested to understanding how pH and/or GLA impact/s under PacC regulation affect PAT production and pathogenesis. ii) To characterize the role of LaeA, the global regulator of mycotoxin production, and its effect on PAT and PacC activity. iii) To identify the signaling pathways leading to GLA and PAT synthesis. Using state- of-the-art RNAseq technologies, we will interrogate the transcriptomes of laeAand pacCmutants, to identify the common signaling pathways regulating synthesis of both GLA and PAT. Major conclusions, solutions, achievements- In our first Aim our results demonstrated that ammonia secreted at the leading edge of the fungal colony induced transcript activation of the global pH modulator PacC and PAT accumulation in the presence of GLA. We assessed these parameters by: (i) direct exogenous treatment of P. expansumgrowing on solid medium; (ii) direct exogenous treatment on colonized apple tissue; (iii) growth under self-ammonia production conditions with limited carbon; and (iv) analysis of the transcriptional response to ammonia of the PAT biosynthesis cluster. Ammonia induced PAT accumulation concurrently with the transcript activation of pacCand PAT biosynthesis cluster genes, indicating the regulatory effect of ammonia on pacCtranscript expression under acidic conditions. Transcriptomic analysis of pH regulated processes showed that important genes and BARD Report - Project 4773 Page 2 of 10 functionalities of P. expansumwere controlled by environmental pH. The differential expression patterns of genes belonging to the same gene family suggest that genes were selectively activated according to their optimal environmental conditions to enable the fungus to cope with varying conditions and to make optimal use of available enzymes. Concerning the second and third Aims, we demonstrated that LaeA regulates several secondary metabolite genes, including the PAT gene cluster and concomitant PAT synthesis invitro. Virulence studies of ΔlaeAmutants of two geographically distant P. expansumisolates (Pe-21 from Israel and Pe-T01 from China) showed differential reduction in disease severity in freshly harvested fruit ranging from no reduction for Ch-Pe-T01 strains in immature fruit to 15–25% reduction for both strains in mature fruit, with the ΔlaeAstrains of Is-Pe-21 always showing a greater loss in virulence. Results suggest the importance of LaeA regulation of PAT and other secondary metabolites on pathogenicity. Our work also characterized for the first time the role of sucrose, a key nutritional factor present in apple fruit, as a negative regulator of laeAexpression and consequent PAT production in vitro. This is the first report of sugar regulation of laeAexpression, suggesting that its expression may be subject to catabolite repression by CreA. Some, but not all of the 54 secondary metabolite backbone genes in the P. expansumgenome, including the PAT polyketide backbone gene, were found to be regulated by LaeA. Together, these findings enable for the first time a straight analysis of a host factor that potentially activates laeAand subsequent PAT synthesis.