Articoli di riviste: "Latency variation"

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Schmid, Andreas, David Halbhuber, Thomas Fischer, Raphael Wimmer e Niels Henze. "Small Latency Variations Do Not Affect Player Performance in First-Person Shooters". Proceedings of the ACM on Human-Computer Interaction 7, CHI PLAY (29 settembre 2023): 197–216. http://dx.doi.org/10.1145/3611027.

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In interactive systems high latency affects user performance and experience. This is especially problematic in video games. A large number of studies on this topic investigated the effects of constant, high latency. However, in practice, latency is never constant but varies by up to 100 ms due to variations in processing time and delays added by polling between system components. In a large majority of studies, these variations in latency are neither controlled for nor reported. Thus, it is unclear to which degree small, continuous variations in latency affect user performance. If these unreported variations had a significant impact, this might cast into doubt the findings of some studies. To investigate how latency variation affects player performance and experience in games, we conducted an experiment with 28 participants playing a first-person shooter. Participants played with two levels of base latency (50 ms vs. 150 ms) and variation (0 ms vs. 50 ms). As expected, high base latency significantly reduces player performance and experience. However, we found strong evidence that small variations in latency in the order of 50 ms, do not affect player performance significantly. Thus, our findings mitigate concerns that previous latency studies might have systematically ignored a confounding effect.

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Wu, Weixin, Yujie Dong e Adam Hoover. "Measuring Digital System Latency from Sensing to Actuation at Continuous 1-ms Resolution". Presence: Teleoperators and Virtual Environments 22, n. 1 (febbraio 2013): 20–35. http://dx.doi.org/10.1162/pres_a_00131.

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This paper describes a new method for measuring the end-to-end latency between sensing and actuation in a digital computing system. Compared to previous works, which generally measured the latency at 10–33-ms intervals or at discrete events separated by hundreds of ms, our new method measures the latency continuously at 1-ms resolution. This allows for the observation of variations in latency over sub 1-s periods, instead of relying upon averages of measurements. We have applied our method to two systems, the first using a camera for sensing and an LCD monitor for actuation, and the second using an orientation sensor for sensing and a motor for actuation. Our results show two interesting findings. First, a cyclical variation in latency can be seen based upon the relative rates of the sensor and actuator clocks and buffer times; for the components we tested, the variation was in the range of 15–50 Hz with a magnitude of 10–20 ms. Second, orientation sensor error can look like a variation in latency; for the sensor we tested, the variation was in the range of 0.5–1.0 Hz with a magnitude of 20–100 ms. Both of these findings have implications for robotics and virtual reality systems. In particular, it is possible that the variation in apparent latency caused by orientation sensor error may have some relation to simulator sickness.

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Gupta, Saket, e Sachin S. Sapatnekar. "Variation-Aware Variable Latency Design". IEEE Transactions on Very Large Scale Integration (VLSI) Systems 22, n. 5 (maggio 2014): 1106–17. http://dx.doi.org/10.1109/tvlsi.2013.2265662.

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Chang, Kevin K., Abhijith Kashyap, Hasan Hassan, Saugata Ghose, Kevin Hsieh, Donghyuk Lee, Tianshi Li, Gennady Pekhimenko, Samira Khan e Onur Mutlu. "Understanding Latency Variation in Modern DRAM Chips". ACM SIGMETRICS Performance Evaluation Review 44, n. 1 (30 giugno 2016): 323–36. http://dx.doi.org/10.1145/2964791.2901453.

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White, A., S. Tatam, D. Linares e A. Holcombe. "Visuomotor compensation for variation in perceptual latency". Journal of Vision 9, n. 8 (3 settembre 2010): 841. http://dx.doi.org/10.1167/9.8.841.

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Fagius, Jan, Göran Sundlöf e B. Gunnar Wallin. "Variation of sympathetic reflex latency in man". Journal of the Autonomic Nervous System 21, n. 2-3 (dicembre 1987): 157–65. http://dx.doi.org/10.1016/0165-1838(87)90018-x.

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Chichibu, Shiko, Atsushi Chiba, Takahide Sugiyama e Takashi Kurita. "Latency variation and habituation in cremasteric reflex". Neuroscience Research Supplements 9 (gennaio 1989): 43. http://dx.doi.org/10.1016/0921-8696(89)90590-2.

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Lee, Donghyuk, Samira Khan, Lavanya Subramanian, Saugata Ghose, Rachata Ausavarungnirun, Gennady Pekhimenko, Vivek Seshadri e Onur Mutlu. "Design-Induced Latency Variation in Modern DRAM Chips". ACM SIGMETRICS Performance Evaluation Review 45, n. 1 (18 settembre 2017): 54. http://dx.doi.org/10.1145/3143314.3078533.

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Lee, Donghyuk, Samira Khan, Lavanya Subramanian, Saugata Ghose, Rachata Ausavarungnirun, Gennady Pekhimenko, Vivek Seshadri e Onur Mutlu. "Design-Induced Latency Variation in Modern DRAM Chips". Proceedings of the ACM on Measurement and Analysis of Computing Systems 1, n. 1 (13 giugno 2017): 1–36. http://dx.doi.org/10.1145/3084464.

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Jacobsen, Frederick M., Adriana Dreizzen e Thomas A. Wehr. "Diurnal mood variation and REM latency in depression". Biological Psychiatry 22, n. 8 (agosto 1987): 1045–47. http://dx.doi.org/10.1016/0006-3223(87)90020-5.

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Jacobsen, Frederick M., Adriana Dreizzen e Thomas A. Wehr. "Diurnal mood variation and REM latency in depression". Biological Psychiatry 22, n. 6 (giugno 1987): 800–801. http://dx.doi.org/10.1016/0006-3223(87)90220-4.

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Arnarson, Hallgrímur, Arnar Pálsson, Margrét Gudnadóttir e Valgerdur Andrésdóttir. "Maedi-visna virus persistence: Antigenic variation and latency". Comparative Immunology, Microbiology and Infectious Diseases 55 (dicembre 2017): 6–12. http://dx.doi.org/10.1016/j.cimid.2017.08.003.

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Burton, M. J., J. M. Miller e P. R. Kileny. "Middle-Latency Responses: II. Variation Among Stimulation Sites". Archives of Otolaryngology - Head and Neck Surgery 115, n. 4 (1 aprile 1989): 458–61. http://dx.doi.org/10.1001/archotol.1989.01860280056017.

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Althoubi, Asaad, Reem Alshahrani e Hassan Peyravi. "Delay Analysis in IoT Sensor Networks". Sensors 21, n. 11 (4 giugno 2021): 3876. http://dx.doi.org/10.3390/s21113876.

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Internet of Things (IoT) devices, particularly those used for sensor networks, are often latency-sensitive devices. The topology of the sensor network largely depends on the overall system application. Various configurations include linear, star, hierarchical and mesh in 2D or 3D deployments. Other applications include underwater communication with high attenuation of radio waves, disaster relief networks, rural networking, environmental monitoring networks, and vehicular networks. These networks all share the same characteristics, including link latency, latency variation (jitter), and tail latency. Achieving a predictable performance is critical for many interactive and latency-sensitive applications. In this paper, a two-stage tandem queuing model is developed to estimate the average end-to-end latency and predict the latency variation in closed forms. This model also provides a feedback mechanism to investigate other major performance metrics, such as utilization, and the optimal number of computing units needed in a single cluster. The model is applied for two classes of networks, namely, Edge Sensor Networks (ESNs) and Data Center Networks (DCNs). While the proposed model is theoretically derived from a queuing-based model, the simulation results of various network topologies and under different traffic conditions prove the accuracy of our model.

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Baker, Stuart N., e George L. Gerstein. "Determination of Response Latency and Its Application to Normalization of Cross-Correlation Measures". Neural Computation 13, n. 6 (1 giugno 2001): 1351–77. http://dx.doi.org/10.1162/08997660152002889.

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It is often of interest experimentally to assess how synchronization between two neurons changes following a stimulus or other behaviorally relevant marker. The joint peristimulus time histogram (JPSTH) achieves this, but assumes that changes in the cells' firing rate following the stimulus are stereotyped from one sweep to the next. Erroneous results can be generated if this is not the case. We here present a method to assess whether there are variations in response latency or amplitude from sweep to sweep. We then describe how the effects of response latency variation can be mitigated by realigning sweeps to their individual latencies. Three methods of detecting response latency are presented and their performance compared on simulated data. Finally, the effect on the JPSTH of sweep realignment using detected latencies is illustrated.

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Perez, Ana, Karin Ziliotto e Liliane Pereira. "Test-Retest of Long Latency Auditory Evoked Potentials (P300) with Pure Tone and Speech Stimuli". International Archives of Otorhinolaryngology 21, n. 02 (26 aprile 2016): 134–39. http://dx.doi.org/10.1055/s-0036-1583527.

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Introduction Long latency auditory evoked potentials, especially P300, have been used for clinical evaluation of mental processing. Many factors can interfere with Auditory Evoked Potential - P300 results, suggesting large intra and inter-subject variations. Objective The objective of the study was to identify the reliability of P3 components (latency and amplitude) over 4–6 weeks and the most stable auditory stimulus with the best test-retest agreement. Methods Ten normal-hearing women participated in the study. Only subjects without auditory processing problems were included. To determine the P3 components, we elicited long latency auditory evoked potential (P300) by pure tone and speech stimuli, and retested after 4–6 weeks using the same parameters. We identified P300 latency and amplitude by waveform subtraction. Results We found lower coefficient of variation values in latency than in amplitude, with less variability analysis when speech stimulus was used. There was no significant correlation in latency measures between pure tone and speech stimuli, and sessions. There was a significant intrasubject correlation between measures of latency and amplitude. Conclusion These findings show that amplitude responses are more robust for the speech stimulus when compared with its pure tone counterpart. The P300 indicated stability for latency and amplitude measures when the test-retest was applied. Reliability was higher for amplitude than for latency, with better agreement when the pure tone stimulus was used. However, further research with speech stimulus is needed to clarify how these stimuli are processed by the nervous system.

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Gomez-Rivera, Francisco, Valeri Terry e Kathleen Collins. "Variation in HIV-1 Tat activity is a key determinant in the establishment of active versus latent infection". Journal of Immunology 212, n. 1_Supplement (1 maggio 2024): 1180_6073. http://dx.doi.org/10.4049/jimmunol.212.supp.1180.6073.

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Abstract Despite effective treatment, Human Immunodeficiency Virus (HIV) remains latent as a transcriptionally silent provirus. Latent cells can evade the immune system and the harmful effects of the virus, thereby creating a long-lasting reservoir of HIV. To gain a deeper insight into the molecular mechanisms of HIV latency establishment, it is crucial to create tools that can detect and isolate cells that are infected with the virus but remain latent. We established a series of HIV-1 reporter constructs to better understand the factors that lead to latency. All the reporters identified the latent cell subset by flow cytometric detection of fluorescent probe expressed from the constitutive promoter without expression of a second fluorescent probe from the HIV LTR. The reporters can distinguish active and latently infected T cell lines and primary cells, including CD4+ T cells, and hematopoietic stem and progenitor cells. We observed that the proportion of active-to-latent infection increased with increasing virus inoculum, shifting the balance towards active infection regardless of the total infection rate. This suggested the hypothesis that at low viral inoculum, the availability of a viral factor needed for active infection was limiting. We demonstrated a reduced effect of inoculum size when tat was overexpressed regardless of whether exogenous Tat was introduced before or after integration. These results provide new insight into the mechanisms that govern latency establishment.

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Young, Keith A., Marinell Smith, Tammie Rawls, Denise B. Elliott, I. Steele Russell e Paul B. Hicks. "N100 evoked potential latency variation and startle in schizophrenia". Neuroreport 12, n. 4 (marzo 2001): 767–73. http://dx.doi.org/10.1097/00001756-200103260-00031.

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Shu, Liu, Feng, Xu, Qian e Yang. "Analysis of Factors Affecting Asynchronous RTK Positioning with GNSS Signals". Remote Sensing 11, n. 10 (27 maggio 2019): 1256. http://dx.doi.org/10.3390/rs11101256.

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For short baseline real-time kinematic (RTK) positioning, the atmosphere and broadcast ephemeris errors can be usually eliminated in double-differenced (DD) processing for synchronous observations. However, in the case of possible communication latency time, these errors may not be eliminated in DD treatments due to their variations during latency time. In addition, the time variation of these errors may present different characteristics among GPS, GLONASS, BDS, and GALILEO due to different satellite orbit and clock types. In this contribution, the formulas for studying the broadcast orbit and clock offset errors and atmosphere error in asynchronous RTK (ARTK) model is proposed, and comprehensive experimental analysis is performed to numerically show time variations of these errors and their impacts on RTK results from short-baselines among four systems. Compared with synchronous RTK, the degradation of position precision for ARTK can reach a few centimeters, but the accuracy degradation to a different degree by different systems. BDS and Galileo usually outperform GPS and GLONASS in ARTK due to the smaller variation of broadcast ephemeris error. The variation of broadcast orbit error is generally negligible compared with the variation of broadcast clock offset error for GPS, BDS, and Galileo. Specifically, for a month of data, the root mean square (RMS) values for the variation of broadcast ephemeris error over 15 seconds are 11.2, 16.9, 7.3, and 3.0 mm for GPS, GLONASS, BDS, and Galileo, respectively. The variation of ionosphere error for some satellites over 15 seconds can reach a few centimeters during active sessions under a normal ionosphere day. In addition, compared with other systems, BDS ARTK shows an advantage under high ionosphere activity, and such advantage may be attributed to five GEO satellites in the BDS constellation.

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Ludwig, Casimir J. H., John W. Mildinhall e Iain D. Gilchrist. "A Population Coding Account for Systematic Variation in Saccadic Dead Time". Journal of Neurophysiology 97, n. 1 (gennaio 2007): 795–805. http://dx.doi.org/10.1152/jn.00652.2006.

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During movement programming, there is a point in time at which the movement system is committed to executing an action with certain parameters even though new information may render this action obsolete. For saccades programmed to a visual target this period is termed the dead time. Using a double-step paradigm, we examined potential variability in the dead time with variations in overall saccade latency and spatiotemporal configuration of two sequential targets. In experiment 1, we varied overall saccade latency by manipulating the presence or absence of a central fixation point. Despite a large and robust gap effect, decreasing the saccade latency in this way did not alter the dead time. In experiment 2, we varied the separation between the two targets. The dead time increased with separation up to a point and then leveled off. A stochastic accumulator model of the oculomotor decision mechanism accounts comprehensively for our findings. The model predicts a gap effect through changes in baseline activity without producing variations in the dead time. Variations in dead time with separation between the two target locations are a natural consequence of the population coding assumption in the model.

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Lee, Joonyeol, Mati Joshua, Javier F. Medina e Stephen G. Lisberger. "Signal, Noise, and Variation in Neural and Sensory-Motor Latency". Neuron 90, n. 1 (aprile 2016): 165–76. http://dx.doi.org/10.1016/j.neuron.2016.02.012.

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Pfeifer, Johann, Virgilio D. Salanga, Feran Agachan, Eric G. Weiss e Steven D. Wexner. "Variation in pudendal nerve terminal motor latency according to disease". Diseases of the Colon & Rectum 40, n. 1 (gennaio 1997): 79–83. http://dx.doi.org/10.1007/bf02055686.

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Pal, Asmita, Aatreyi Bal, Koushik Chakraborty e Sanghamitra Roy. "Split Latency Allocator: Process Variation-Aware Register Access Latency Boost in a Near-Threshold Graphics Processing Unit". Journal of Low Power Electronics 13, n. 3 (1 settembre 2017): 419–27. http://dx.doi.org/10.1166/jolpe.2017.1508.

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Jack, Robert H., Adib Mehrabi, Tony Stockman e Andrew McPherson. "Action-sound Latency and the Perceived Quality of Digital Musical Instruments". Music Perception 36, n. 1 (1 settembre 2018): 109–28. http://dx.doi.org/10.1525/mp.2018.36.1.109.

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Asynchrony between tactile and auditory feedback (action-sound latency) when playing a musical instrument is widely recognized as disruptive to musical performance. In this paper we present a study that assesses the effects of delayed auditory feedback on the timing accuracy and judgments of instrument quality for two groups of participants: professional percussionists and non-percussionist amateur musicians. The amounts of delay tested in this study are relatively small in comparison to similar studies of auditory delays in a musical context (0 ms, 10 ms, 10 ms ± 3 ms, 20 ms). We found that both groups rated the zero latency condition as higher quality for a series of quality measures in comparison to 10 ms ± 3 ms and 20 ms latency, but did not show a significant difference in rating between 10 ms latency and zero latency. Professional percussionists were more aware of the latency conditions and showed less variation of timing under the latency conditions, although this ability decreased as the temporal demands of the task increased. We compare our findings from each group and discuss them in relation to latency in interactive digital systems more generally and experimentally similar work on sensorimotor control and rhythmic performance.

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Ma, Jinzhe, Yangyang Han, Yiting Yao, Huimei Wang, Mengxia Chen, Ziying Fu, Qicai Chen e Jia Tang. "Investigation of Neuron Latency Modulated by Bilateral Inferior Collicular Interactions Using Whole-Cell Patch Clamp Recording in Brain Slices". Neural Plasticity 2021 (10 dicembre 2021): 1–13. http://dx.doi.org/10.1155/2021/8030870.

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As the final level of the binaural integration center in the subcortical nucleus, the inferior colliculus (IC) plays an essential role in receiving binaural information input. Previous studies have focused on how interactions between the bilateral IC affect the firing rate of IC neurons. However, little is known concerning how the interactions within the bilateral IC affect neuron latency. In this study, we explored the synaptic mechanism of the effect of bilateral IC interactions on the latency of IC neurons. We used whole-cell patch clamp recordings to assess synaptic responses in isolated brain slices of Kunming mice. The results demonstrated that the excitation-inhibition projection was the main projection between the bilateral IC. Also, the bilateral IC interactions could change the reaction latency of most neurons to different degrees. The variation in latency was related to the type of synaptic input and the relative intensity of the excitation and inhibition. Furthermore, the latency variation also was caused by the duration change of the first subthreshold depolarization firing response of the neurons. The distribution characteristics of the different types of synaptic input also differed. Excitatory-inhibitory neurons were widely distributed in the IC dorsal and central nuclei, while excitatory neurons were relatively concentrated in these two nuclei. Inhibitory neurons did not exhibit any apparent distribution trend due to the small number of assessed neurons. These results provided an experimental reference to reveal the modulatory functions of bilateral IC projections.

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Conroy, Matthew A., e John Polich. "Normative Variation of P3a and P3b from a Large Sample". Journal of Psychophysiology 21, n. 1 (gennaio 2007): 22–32. http://dx.doi.org/10.1027/0269-8803.21.1.22.

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Abstract. The P3a and P3b components were elicited in 120 (60 females, 60 males) young adults using a visual three-stimulus event-related brain potential (ERP) oddball paradigm in which subjects responded to an infrequent target. The major purpose of the paper was to provide a statistically strong characterization of these related P300 subcomponents. P3a components were obtained from the infrequently presented distracter stimulus, which was a large blue square. P3b components were obtained from the target stimulus, which was a blue circle that differed slightly in diameter from the standard stimulus blue circle. Amplitude measures demonstrated that P3a was maximum at Cz, and P3b was maximum at Pz; latency measures increased for both potentials from frontal to parietal recording sites. P3a and P3b from females were larger and later than those from male subjects, with topographic and appreciable individual difference variability observed. P3a was generally unrelated to response time. P3b amplitude was negatively correlated over right frontal areas with P3b latency and positively correlated over right parietal areas to response time. Theoretical implications are discussed.

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Oswald, M., e B. D. Robison. "Strain-specific alteration of zebrafish feeding behavior in response to aversive stimuli". Canadian Journal of Zoology 86, n. 10 (ottobre 2008): 1085–94. http://dx.doi.org/10.1139/z08-085.

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Behavioral management of risk, in which organisms must balance the requirements of obtaining food resources with the risk of predation, has been of considerable interest to ethologists for many years. Although numerous experiments have shown that animals alter their foraging behavior depending on the levels of perceived risk and demand for nutrients, few have considered the role of genetic variation in the trade-off between these variables. We performed a study of four zebrafish ( Danio rerio (Hamilton, 1822)) strains to test for genetic variation in foraging behavior and whether this variation affected their response to both aversive stimuli and nutrient restriction. Zebrafish strains differed significantly in their latency to begin foraging from the surface of the water under standard laboratory conditions. Fish fed sooner when nutrients were restricted, although this was only significant in the absence of aversive stimuli. Aversive stimuli caused fish to delay feeding in a strain-specific manner. Strains varied in food intake and specific growth rate, and feeding latency was significantly correlated with food intake. Our results indicate significant genetic variation in foraging behavior and the perception of risk in zebrafish, with a pattern of strain variation consistent with behavioral adaptation to captivity.

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Chisholm, Rebecca H., e Mark M. Tanaka. "The emergence of latent infection in the early evolution of Mycobacterium tuberculosis". Proceedings of the Royal Society B: Biological Sciences 283, n. 1831 (25 maggio 2016): 20160499. http://dx.doi.org/10.1098/rspb.2016.0499.

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Mycobacterium tuberculosis has an unusual natural history in that the vast majority of its human hosts enter a latent state that is both non-infectious and devoid of any symptoms of disease. From the pathogen perspective, it seems counterproductive to relinquish reproductive opportunities to achieve a détente with the host immune response. However, a small fraction of latent infections reactivate to the disease state. Thus, latency has been argued to provide a safe harbour for future infections which optimizes the persistence of M. tuberculosis in human populations. Yet, if a pathogen begins interactions with humans as an active disease without latency, how could it begin to evolve latency properties without incurring an immediate reproductive disadvantage? We address this question with a mathematical model. Results suggest that the emergence of tuberculosis latency may have been enabled by a mechanism akin to cryptic genetic variation in that detrimental latency properties were hidden from natural selection until their expression became evolutionarily favoured.

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Yolanda, Dea Amelia, Dwi Cahyani Ratna Sari, Mawaddah Ar Rochmah e Sri Suharmi. "THE DOSE VARIATIONS EFFECT OF Centella asiatica ETHANOL EXTRACT ON ESCAPE LATENCY’S DISTANCE MORRIS WATER MAZE AFTER CHRONIC ELECTRICAL STRESS". KnE Life Sciences 2, n. 1 (20 settembre 2015): 146. http://dx.doi.org/10.18502/kls.v2i1.134.

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Centella asiatica sp. (pegagan) has neurotropic and neuroprotective properties which inhibit deterioration of memory because of chronic electrical stress. Studies about effective dose of Centtela asiatica still continued. This study was conducted to discover the influence of pegagan extract’s dose variation intake towards memory after chronic stress. This study uses that true experimental design with pretest-posttest control design. Fifteen male Sprague Dawley rats were divided into three groups randomly. Every groups are treated with chronic electrical stress for 4 weeks and aquades (KN), 300 (KN1) or 600 mg/kgBW/day (KP2) of Centella asiatica. The escape latency distance measure using Morris water maze was used to assess rats’ memory. Data were analyzed using the Kolmogorov-Smirnov, ANOVA and paired t-test. The average of escape latency distance before chronic electrical stress were 5,71±0,77m (KN); 4,29±0,36m (KP1); 3,81±0,47m (KP2) and after chronic electrical stress were 1,50±0,05m(KN); 1,55±0,04m(KP1); 1,82±0,11m(KP2). There were significant differences among groups after chronic electrical stress on day-1 (p=0,005) and day-3 (p=0,001). There were significant differences (p<0,05) for 3 days of escape latency test (KN), 5 days of escape latency test (KP1) and 2 days of escape latency test (KP2) from 6 days of memory measurement. In conclusion, dose variation of Centella asiatica did not affect to latency distance using Morris water maze. Ethanol extract of Centella asiatica with doses 300mg/kgBW/day could stimulate increasing memory formation after chronic electrical stress better. Keywords: Centella asiatica - chronic electrical stress– memory– Morris water maze.

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Daan, S., e D. G. Beersma. "Commentary on the mutual interaction model of McCarley and Massaquoi for REM-NREM cycle". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 251, n. 6 (1 dicembre 1986): R1030—R1032. http://dx.doi.org/10.1152/ajpregu.1986.251.6.r1030.

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McCarley and Massaquoi successfully simulated human REM-NREM cycle characteristics by extending the McCarley-Hobson model with two sets of assumptions, one creating limit cycle behavior, the other introducing two sources of circadian variation. We argue that the limit cycle assumptions, due to freedom in choosing parameter values, suffice to explain variation in REM across the night. Nonmonotonic circadian variation in REM latency requires a circadian cycle dependence only of initial conditions at sleep onset.

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Mizuochi, Tomomi, Masato Yumoto, Shotaro Karino, Kenji Itoh e Tatsuya Yamasoba. "Latency variation of auditory N1m responses to vocal and nonvocal sounds". NeuroReport 18, n. 18 (dicembre 2007): 1945–49. http://dx.doi.org/10.1097/wnr.0b013e3282f202c6.

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Liang, Xiaoyao, Gu-Yeon Wei e David Brooks. "Revival: A Variation-Tolerant Architecture Using Voltage Interpolation and Variable Latency". IEEE Micro 29, n. 1 (gennaio 2009): 127–38. http://dx.doi.org/10.1109/mm.2009.13.

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Lee, Joonyeol, Timothy R. Darlington e Stephen G. Lisberger. "The Neural Basis for Response Latency in a Sensory-Motor Behavior". Cerebral Cortex 30, n. 5 (11 dicembre 2019): 3055–73. http://dx.doi.org/10.1093/cercor/bhz294.

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Abstract We seek a neural circuit explanation for sensory-motor reaction times. In the smooth eye movement region of the frontal eye fields (FEFSEM), the latencies of pairs of neurons show trial-by-trial correlations that cause trial-by-trial correlations in neural and behavioral latency. These correlations can account for two-third of the observed variation in behavioral latency. The amplitude of preparatory activity also could contribute, but the responses of many FEFSEM neurons fail to support predictions of the traditional “ramp-to-threshold” model. As a correlate of neural processing that determines reaction time, the local field potential in FEFSEM includes a brief wave in the 5–15-Hz frequency range that precedes pursuit initiation and whose phase is correlated with the latency of pursuit in individual trials. We suggest that the latency of the incoming visual motion signals combines with the state of preparatory activity to determine the latency of the transient response that controls eye movement. Impact statement The motor cortex for smooth pursuit eye movements contributes to sensory-motor reaction time through the amplitude of preparatory activity and the latency of transient, visually driven responses.

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Bendjaballah, Sabrina, e David Le Gac. "Geminate latency in Djibouti Somali". Brill's Journal of Afroasiatic Languages and Linguistics 16, n. 1 (25 giugno 2024): 35–64. http://dx.doi.org/10.1163/18776930-01601002.

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Abstract Our aim in this article is first to contribute to the documentation of the diatopic variation in the realization of Somali geminates, and second to determine whether Djibouti Somali exhibits geminate latency, on a par with Standard Somali (Barillot 2002, Barillot & Ségéral 2005). To this effect, we present the results of two production experiments that were conducted with one Djibouti Somali speaker. Section 1 examines the realization of the contrast /b, d, ɡ/ vs /bb, dd, ɡɡ/ in nouns in Djibouti Somali (Experiment 1-Nouns) in comparison with the previous experiment we conducted on Standard Somali (Bendjaballah & Le Gac 2021). Based on the results of this experiment, Section 2 addresses the question of geminate latency in Djibouti Somali. ‘Latent’ geminates are segments that are phonologically long but whose phonetic duration is short. We examine the acoustic realization of voiced singletons (/b, d, ɡ/), voiced geminates (/bb, dd, ɡɡ/) and voiceless geminates (/tt, kk/) in Djibouti Somali (Experiment 2-Verbs). Section 3 concludes the article, and argues in favour of an extension of geminate latency both in Standard Somali and in Djibouti Somali: geminate latency does not only concern the voiceless stops but also the voiced stops.

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Larsen, T. E., S. B. Mogensen e I. Holme. "Seasonal variations of pigmented naevi. Intercorrelations of clinical and histological variables with special reference to seasonal variation." Acta Dermato-Venereologica 70, n. 2 (1 marzo 1990): 115–20. http://dx.doi.org/10.2340/0001555570115120.

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During 1984, junctional and compound naevi were registered significantly more often during the summer half-year (May-October) than the total number of naevi, which showed no seasonal variation. A series of 342 of these junctional and compound naevi have been the subject of a blind histological classification. Clinical information was obtained by a questionnaire mailed to the patients. The intercorrelations of 19 histological and 10 clinical variables were studied by chi 2-test. The seasonal variation of these variables was further studied by chi 2-test and by Hewitt's test. Patient's hair colour, eye colour and sex as well as mitoses and localization showed a significant correlation to season of the year. The trends of these findings, compared with the information about tumour duration, indicate a short-term latency effect of UV light on naevi which are excised during the summer half-year.

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Chin Ike, Tan, Tan Wee Hoe, Siti Fazilah Shamsudin, Sujata Navaratnam e Ng Yiing Y'ng. "Investigating the Impact of Latency in Mobile-Based Multiplayer Online Battle Arena (MOBA) Games". International Journal of Creative Multimedia 3, n. 1 (30 aprile 2022): 1–16. http://dx.doi.org/10.33093/ijcm.2022.3.1.1.

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The mobile games industry dominates across Southeast Asia, a region reportedly with the highest smartphone ownership in the world and surprisingly, a below world average Internet speed in general. This begs the question then, how much latency is required for mobile games especially in competitive gaming? This research aims to examine players' perceived experience of latency in mobile games and how much latency drop would affect the players overall gameplay experience. Through a controlled testing environment and a variation of latency through a throttling system, the research was able to determine at which point the players perceived a drop in game playing experience. A group of 29 participants played nine rounds of popular MOBA game - Mobile Legends: Bang Bang (MLBB) sessions which were randomly conducted in a dedicated physical location. Each play session was around two hours, and all participants played a minimum of two games within that session. After each play session, the participants were given a survey of six questionnaire items to rate their perceived latency and the overall game playing experience. One-way ANOVA tests were run to determine whether there was significant difference across nine latency rates. The findings revealed that the optimum latency for playing MLBB was 55ms. However, the players’ game performance was affected beyond the 55ms range, in which negative game playing experience may start to build. Thus, the research found that the optimum latency range for enhanced player performance and experience can be set at the 55ms rate and below when playing MOBA games on a mobile platform.

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Prather, Aric A., Eli Puterman, Jue Lin, Aoife O'Donovan, Jeffrey Krauss, A. Janet Tomiyama, Elissa S. Epel e Elizabeth H. Blackburn. "Shorter Leukocyte Telomere Length in Midlife Women with Poor Sleep Quality". Journal of Aging Research 2011 (2011): 1–6. http://dx.doi.org/10.4061/2011/721390.

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Background. Accumulating evidence supports leukocyte telomere length (LTL) as a biological marker of cellular aging. Poor sleep is a risk factor for age-related disease; however, the extent to which sleep accounts for variation in LTL is unknown.Methods. The present study examined associations of self-reported sleep duration, onset latency, and subjective quality with LTL in a community-dwelling sample of 245 healthy women in midlife (aged 49–66 years).Results. While sleep duration and onset latency were unrelated to LTL, women reporting poorer sleep quality displayed shorter LTL (r=0.14,P=0.03), independent of age, BMI, race, and income (b=55.48,SE=27.43,P=0.04). When analyses were restricted to participants for whom sleep patterns were chronic, poorer sleep quality predicted shorter LTL independent of covariates and perceived psychological stress.Conclusions. This study provides the first evidence that poor sleep quality explains significant variation in LTL, a marker of cellular aging.

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Adams, Colton B., Monica Papeş, Charles A. Price e Todd M. Freeberg. "Influence of social and physical environmental variation on antipredator behavior in mixed-species parid flocks". PLOS ONE 18, n. 12 (21 dicembre 2023): e0295910. http://dx.doi.org/10.1371/journal.pone.0295910.

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Carolina chickadees (Poecile carolinensis) and tufted titmice (Baeolophus bicolor) regularly form flocks with multiple species through the winter months, including white-breasted nuthatches (Sitta carolinensis). Earlier studies found that behavior of both chickadees and titmice was sensitive to mixed-species flock composition. Little is known about the influence of background noise level and vegetation density on the antipredator behaviors of individuals within these flocks, however. We tested for the effects of vegetation density, traffic noise, and flock composition (conspecific number, flock diversity, and flock size) on antipredator behavioral responses following an alarm call playback (Study 1) and an owl model presentation (Study 2) at feeders. We recorded background traffic noise and performed lidar scans to quantify vegetation density at each site. After a feeder had been stocked with seed and a flock was present, we recorded calls produced, and we identified flock composition metrics. We coded seed-taking latency, call latency, mob latency, and mob duration following the respective stimulus presentation and tested for effects of flock composition metrics, vegetation density, and background noise on these responses. For the alarm call playback study, flock composition drove behaviors in chickadees and titmice, and vegetation density drove behaviors in chickadees and nuthatches. For the owl model study, conspecific number predicted behavior in chickadees, and mob duration was predicted by nuthatch number. The results reveal individual sensitivity to group composition in anti-predatory and foraging behavior in simulated risky contexts. Additionally, our data suggest that the modality of perceived simulated risk (acoustic vs. visual) and the density of vegetation influence behavior in these groups.

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McCarley, R. W., e S. G. Massaquoi. "A limit cycle mathematical model of the REM sleep oscillator system". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 251, n. 6 (1 dicembre 1986): R1011—R1029. http://dx.doi.org/10.1152/ajpregu.1986.251.6.r1011.

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A limit cycle mathematical model of the rapid-eye-movement (REM) sleep oscillator system has been developed from a structural model of interaction of populations of REM-on and REM-off neurons. The marked differences in latency, amplitude, and duration of the first REM sleep period seen with circadian variation and depressive pathology are modeled by beginning the REM oscillation at different initial points relative to the final position in the limit cycle. Beginning from a point that is graphically interior to the limit cycle produces a long-latency, short-duration, and less intense first REM period. Beginning from a point graphically exterior to the limit cycle produces a short-latency, long-duration, and more intense first REM period. In the model the determinant of whether the oscillation begins exterior or interior to the limit cycle is the time course of decay of the REM-off population discharge activity at sleep onset. When this time course is made to depend on circadian phase, the model produces a very close match to the empirically observed large shifts between the first and second REM periods in duration (often a 50% change) and intensity and also closely mimics the empirically observed shifts in REM latency as human sleep begins at different circadian phases. Although this variation in limit cycle entry accounts for the major changes in REM sleep over the night, the model also postulates a continuous but small circadian variation (of the order of +/- 5% change in REM parameters) acting throughout the course of a night's sleep. Because the model is derived from actual physiological data, rather than being a purely ad hoc or phenomenological construct, it offers the possibility of direct tests of its postulates through neurobiological studies in animals, by circadian phase-related manipulations of the sleep cycle, and through perturbations of the system in humans by the use of drugs. Indeed, an explicit phase-response curve of the system to cholinergic agonists has been developed; this will permit experimental tests of the model in both animals and humans.

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SEKI, HAREAKI, ITARU KIMURA, AYUMU OHNUMA, SHUN-ICHI SASO e KYUYA KOGURE. "The Auditory Evoked Middle-Latency Responses(MLRs): Their Normative Variation and Generators." Tohoku Journal of Experimental Medicine 170, n. 3 (1993): 157–67. http://dx.doi.org/10.1620/tjem.170.157.

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Plassman, B. L., e S. C. Gandevia. "High-voltage stimulation over the human spinal cord: sources of latency variation." Journal of Neurology, Neurosurgery & Psychiatry 52, n. 2 (1 febbraio 1989): 213–17. http://dx.doi.org/10.1136/jnnp.52.2.213.

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Lin, Ge, Xu Renhui, Peng Laixian, Li Aijing e Yang Yaoqi. "A low-delay information sharing algorithm for multiple-radio-per-platform networking". International Journal of Distributed Sensor Networks 17, n. 2 (febbraio 2021): 155014772199442. http://dx.doi.org/10.1177/1550147721994424.

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In order to ensure the strong real-time information sharing of Aerial Ad hoc Network, a low-delay information sharing algorithm for multiple-radio-per-platform networking is proposed based on the directional transmission capability of phased-array antenna. The algorithm introduces virtual nodes and virtual links in the process of topology generation first. By extracting topology information and choosing link grouping, it can effectively reduce redundant transmission and transmission latency of information sharing. Then, it is verified through simulation that the algorithm can reduce the latency by up to 49.8% and eliminate transmission redundancy. In addition, a direction selection algorithm is proposed for the variation of antenna beam direction. Simulation results show that the algorithm can further reduce the latency of information sharing and ensure the real time of information sharing, thus further improving the network performance.

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Al-Ali, Eng Mohammad, e Eng Nazeeha Al Dokhan. "Comparative Analysis of 4G and 5G Network Speeds Across Adailiya, Kaifan, and Yarmouk in Kuwait". International Journal of Engineering Research and Applications 14, n. 10 (ottobre 2024): 45–50. http://dx.doi.org/10.9790/9622-14104550.

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This study provides a comprehensive evaluation of the outdoor performance of 4G and 5G networks across the neighborhoods of Adailiya, Kaifan, and Yarmouk in Kuwait. The analysis focuses on key performance metrics, including ping (latency), jitter (latency variation), download speeds, and upload speeds. Field tests conducted in various outdoor locations reveal that 5G significantly outperforms 4G in all measured parameters. Average download speeds on 5G reached up to 444 Mbps, while 4G managed 50 Mbps. Similarly, upload speeds were markedly higher on 5G, averaging 53 Mbps compared to 31 Mbps on 4G. Furthermore, 5G networks demonstrated substantial improvements in latency and jitter, ensuring a more stable and responsive connection. These findings underscore the transformative potential of 5G for enhancing outdoor connectivity in residential areas and highlight the need for further infrastructure development to ensure consistent coverage and performance.

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Kouyoumdjian, João Aris, André Tosta Ribeiro, Luciano Vaccari Grassi e Márcia Spressão. "Influence of temperature on comparative nerve conduction techniques for carpal tunnel syndrome diagnosis". Arquivos de Neuro-Psiquiatria 63, n. 2b (giugno 2005): 422–26. http://dx.doi.org/10.1590/s0004-282x2005000300011.

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In this study we compared the effect of temperature variation (>32ºC to <27ºC) on latency differences median to ulnar (ringdiff), median to radial (thumbdiff), palmar median to ulnar (palmdiff) and the sum of three, the combined sensory index (CSI), in 15 controls and 12 patients with carpal tunnel syndrome (CTS). After cooling, ringdiff was the most reliable technique with little variation in both controls and patients; thumbdiff decreased dramatically in controls and could even come within normal limits in patients; palmdiff increased only in patients; CSI decreased significantly in controls and showed a slight increase in patients with no loss in electrodiagnosis accuracy. The high increase of palmdiff in patients, and the high decrease of thumbdiff in controls, after cooling, could not be explained only for fiber size in the nerve trunks. We concluded that for CTS electrodiagnosis even latency differences in same person/same limb could be significantly modified after cooling not previously emphasized in literature.

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Kommana, Kusuma, e Lolugu SandhyaRani. "A Survey on Challenges of Millimeter Wave Communications for Fifth-Generation Wireless Networks". INTERANTIONAL JOURNAL OF SCIENTIFIC RESEARCH IN ENGINEERING AND MANAGEMENT 07, n. 12 (23 dicembre 2023): 1–13. http://dx.doi.org/10.55041/ijsrem27765.

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Abstract-Cellular networks rely heavily on downlink beamforming; however, calculating beamformers that maximize the weighted sum rate (WSR) under power constraints is an NP-hard problem. A weighted minimum mean square error (WMMSE) algorithm variant is suggested for a MU-MISO downlink channel in order to address this trade-off between complexity and performance. This variation avoids bisection searches, eigendata compositions, and matrix inversions—all of which are challenging to implement as conventional network layers. With a reduced complexity, the suggested network architecture outperforms the WMMSE algorithm truncated to the same number of iterations and adapts well to variations in the channel distribution. Many use cases for vehicles that demand high capacity, extremely low latency, and high reliability can be made possible by 5G. To facilitate this, 5G For a MU-MISO downlink channel, a variation of the weighted minimum mean square error (WMMSE) algorithm is proposed to address this trade-off between complexity and performance. This variation avoids complex network layer implementations such as matrix inversions, eigendata compositions, and bisection searches. The suggested network architecture generalizes well to changes in the channel distribution and performs comparably to the WMMSE algorithm truncated to the same number of iterations, but at a lower complexity. Numerous automotive use cases requiring high capacity, extremely low latency, and high reliability can be made possible by 5G. 5G suggests using highly directed mm Wave system deployment and dense small cell technology to support this. To reduce the cost of signaling, however, enabling vehicular communication necessitates strong mobility management strategies. KEYWORD: Millimetre wave communications, propagation, channel measurements, channel models, MIMO, hybrid precoding, non-orthogonal multiple access (NOMA), multiple access techniques, simultaneous wireless information and power transfer (SWIPT), RF energy harvesting.

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Chen, Shun-Hua, Lily Yeh Lee, David A. Garber, Priscilla A. Schaffer, David M. Knipe e Donald M. Coen. "Neither LAT nor Open Reading Frame P Mutations Increase Expression of Spliced or Intron-Containing ICP0 Transcripts in Mouse Ganglia Latently Infected with Herpes Simplex Virus". Journal of Virology 76, n. 10 (15 maggio 2002): 4764–72. http://dx.doi.org/10.1128/jvi.76.10.4764-4772.2002.

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ABSTRACT Latent infections by herpes simplex virus are characterized by repression of productive-cycle gene expression. Several hypotheses to explain this repression involve inhibition of expression of the immediate-early gene activator ICP0 during latency. To address these hypotheses, we developed quantitative reverse transcriptase-PCR assays that detected spliced and intron-containing ICP0 transcripts in mouse ganglia latently infected with wild-type virus. In these ganglia, the numbers of spliced ICP0 transcripts correlated better with the numbers of transcripts from the immediate-early gene encoding ICP4 than with those from the early gene encoding thymidine kinase. There were fewer spliced than intron-containing ICP0 transcripts on average, with considerable ganglion-to-ganglion variation. We then investigated whether ICP0 expression in latently infected ganglia is reduced by the latency-associated transcripts (LATs) and whether splicing of ICP0 transcripts is inhibited by the product of open reading frame (ORF) P. A LAT deletion mutation which essentially eliminates expression of the major LATs did not appreciably increase levels of ICP0 transcripts. LAT deletion mutants did, however, appear to express reduced levels of intron-containing ICP0 transcripts. ORF P mutations did not alter levels of ICP0 transcripts in a manner consistent with inhibition of ICP0 splicing by ORF P. Although these results argue against antisense inhibition of ICP0 expression by LATs or inhibition of ICP0 splicing by ORF P, they are consistent with the possibilities of a block between immediate-early and early gene expression and regulation of spliced versus intron-containing ICP0 transcripts in latently infected ganglia.

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Sato, Yasuharu, Hirooki Yabe, Tomiharu Hiruma, Takeyuki Sutoh, Naoko Shinozaki, Tadayoshi Nashida, Takashi Matsuoka e Sunao Kaneko. "Early Contingent Negative Variation (CNV) Shows a Small Symmetrical Negativity in a Somatosensory Paradigm". Clinical Electroencephalography 33, n. 2 (aprile 2002): 77–81. http://dx.doi.org/10.1177/155005940203300206.

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The influence of sensory modulation on the early stage of information processing was investigated with a somatosensory contingent negative variation (CNV) paradigm. Whether or not even a somatosensory input as well as auditory or visual stimulus to one hemisphere elicits the symmetrical “early CNV” was also examined. Eleven normal individuals (3 males, 8 females) performed a conventional CNV paradigm with a click sound as the warning stimulus (WS) and a red light flash as the imperative stimulus (IS). Nine individuals (5 males, 4 females) did the somatosensory CNV paradigm with paired electrical stimuli as WS and IS. The subjects were instructed to press a button in response to IS as fast as possible. The early CNV amplitude was smaller and P300 latency was longer in somatosensory paradigm than conventional paradigm. In addition, the latency of P100 in a somatosensory paradigm was longer than that of N100 in a conventional paradigm. These findings suggest that the initiation of early detection, reflected by P100, the initiation of cognition, reflected by P300, and orienting response, reflected by early CNV, are delayed in a somatosensory CNV paradigm. Furthermore, all event-related potentials (ERPs) evoked by somatosensory stimuli showed a bilateral symmetry.

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Abdelkader, Hamed Ibrahem, Mona Abdelkader, Mohammed Kabeel e Malak Alya. "Visual Evoked potential signal processing and analysis for normal and galucomic eyes". JOURNAL OF ADVANCES IN PHYSICS 8, n. 2 (15 aprile 2015): 2106–21. http://dx.doi.org/10.24297/jap.v8i2.1516.

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Visual evoked potentials (VEPS) are obtained from optic tract by recording the evoked potentials generated by retinal stimulation. The flash VEP (FVEP) is used less frequently than pattern reversal VEP (PRVEP) because; it shows great variation in both latency and amplitude. The present study was undertaken to evaluate the effect of change of wavelength of flash and change of check size on the parameters of visual evoked potential (amplitude and latency) in normal individuals and glaucoma patients. The group of healthy subjects in the age of 20-45 years while the group of glaucoma subjects where Â in the age of 25-50 years. Â The two groups were exposed to flash VEP with white light and blue color and they also were exposed to checks subtending a visual angles of 15, 30,60 and 120 minutes of arc. The measured data were statistically analyzed and summarized by histograms. The interindividual and intraindividual in latencies and amplitudes for FVEP were assessed using Â the coefficient of variation (COV). In conclusion, monochromatic flash VEP was preferred than white as there were minimal inter and intra individual variation of latencies and amplitudes. The most preferred check size in PRVEP was 120' for Â the two groups.Â Â

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Kashio, Akinori, Viral D. Tejani, Rachel A. Scheperle, Carolyn J. Brown e Paul J. Abbas. "Exploring the Source of Neural Responses of Different Latencies Obtained from Different Recording Electrodes in Cochlear Implant Users". Audiology and Neurotology 21, n. 3 (2016): 141–49. http://dx.doi.org/10.1159/000444739.

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In this study we measured the electrically evoked compound action potential (ECAP) from different recording electrodes in the cochlea. Under the assumption that different response latencies may be the result of differences in the neural population contributing to the response, we assessed the relationship between neural response latency and spread of excitation. First, we evaluated changes in N1 latency when the recording electrode site was varied. Second, we recorded channel interaction functions using a forward masking technique but with recording electrodes at different intracochlear locations. For most individuals, N1 latency was similar across recording electrodes. However, reduced N1 latencies were observed in 21% of cochlear implant users when ECAPs were recorded using a remote recording electrode. We hypothesized that if recordings from different electrodes represented contributions from different populations of neurons, then one might expect that channel interaction functions would be different. However, we did not observe consistent differences in channel interaction functions (neither peak location nor breadth of the functions), and further, any variation in channel interaction functions was not correlated with ECAP latency. These results suggest that ECAPs from different recording electrodes with different latencies originate from similar neural populations.

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Arieli, R., O. Ertracht, I. Oster, A. Vitenstein e Y. Adir. "Effects of nitrogen and helium on CNS oxygen toxicity in the rat". Journal of Applied Physiology 98, n. 1 (gennaio 2005): 144–50. http://dx.doi.org/10.1152/japplphysiol.00506.2004.

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The contribution of inert gases to the risk of central nervous system (CNS) oxygen toxicity is a matter of controversy. Therefore, diving regulations apply strict rules regarding permissible oxygen pressures (Po2). We studied the effects of nitrogen and helium (0, 15, 25, 40, 50, and 60%) and different levels of Po2 (507, 557, 608, and 658 kPa) on the latency to the first electrical discharge (FED) in the EEG in rats, with repeated measurements in each animal. Latency as a function of the nitrogen pressure was not homogeneous for each rat. The prolongation of latency observed in some rats at certain nitrogen pressures, mostly in the range 100 to 500 kPa, was superimposed on the general trend for a reduction in latency as nitrogen pressure increased. This pattern was an individual trait. In contrast with nitrogen, no prolongation of latency to CNS oxygen toxicity was observed with helium, where an increase in helium pressure caused a reduction in latency. This bimodal response and the variation in the response between rats, together with a possible effect of ambient temperature on metabolic rate, may explain the conflicting findings reported in the literature. The difference between the two inert gases may be related to the difference in the narcotic effect of nitrogen. Proof through further research of a correlation between individual sensitivity to nitrogen narcosis and protection by N2 against CNS oxygen toxicity in rat may lead to a personal O2 limit in mixed-gas diving based on the diver sensitivity to N2 narcosis.

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