Latency (engineering)

About: Latency (engineering) is a research topic. Over the lifetime, 7278 publications have been published within this topic receiving 115409 citations. The topic is also known as: lag.

Human Embryonic Stem Cell Lines Model Experimental Human Cytomegalovirus Latency

Abstract: Herpesviruses are highly successful pathogens that persist for the lifetime of their hosts primarily because of their ability to establish and maintain latent infections from which the virus is capable of productively reactivating. Human cytomeg- alovirus (HCMV), a betaherpesvirus, establishes latency in CD34hematopoietic progenitor cells during natural infections in the body. Experimental infection of CD34 cells ex vivo has demonstrated that expression of the viral gene products that drive productive infection is silenced by an intrinsic immune defense mediated by Daxx and histone deacetylases through heterochro- matinization of the viral genome during the establishment of latency. Additional mechanistic details about the establishment, let alone maintenance and reactivation, of HCMV latency remain scarce. This is partly due to the technical challenges of CD34cell culture, most notably, the difficulty in preventing spontaneous differentiation that drives reactivation and renders them permis- sive for productive infection. Here we demonstrate that HCMV can establish, maintain, and reactivate in vitro from experimen- tal latency in cultures of human embryonic stem cells (ESCs), for which spurious differentiation can be prevented or controlled. Furthermore, we show that known molecular aspects of HCMV latency are faithfully recapitulated in these cells. In total, we present ESCs as a novel, tractable model for studies of HCMV latency. IMPORTANCE Human cytomegalovirus (HCMV) is a significant human pathogen that is known for causing birth defects, blind- ness in AIDS patients, and organ transplant rejection. The ability of HCMV to cause disease is dependent upon its capacity to establish and maintain latent infections. Very few of the molecular mechanisms of latency have been elucidated, due in part to the lack of a tractable cell culture model. Here we present embryonic stem cells (ESCs) as a model for HCMV latency, one in which genome maintenance and reactivation could be closely monitored. HCMV establishes latency in ESCs in the same fashion as it does in CD34 cells, the currently favored in vitro model. Hence, ESCs represent a novel model with unique properties, such as the ability to be genetically manipulated and cultured indefinitely in an undifferentiated state, that will facilitate the mechanistic examination of certain aspects of HCMV latency that have proven technically challenging in other model systems.

Method of receiving compressed video signals using a latency buffer during pause and resume

Abstract: The invention relates to the reception of MPEG encoded television signals from a Video-On-Demand server (1) via a network (3). Non-linear playback functions such as `pause` and `resume` require a very accurate control of the bit stream, taking account of typical network aspects such as network latency. The receiver (2) comprises a latency buffer (24) for storing the signal delivered while the reproduction is stalled. The pause and resume commands from the user are not forwarded to the server until the latency buffer reaches a predetermined fullness. This allows the receiver to resume flawlessly signal reproduction after a pause.

Measuring and reducing observational latency when recognizing actions

Abstract: An important aspect in interactive, action-based interfaces is the latency in recognizing the action. High latency will cause the system's feedback to lag behind user actions, reducing the overall quality of the user experience. This paper presents a novel dataset and algorithms for reducing the latency in recognizing the action. Latency in classification is minimized with a classifier based on logistic regression that uses canonical poses to identify the action. The classifier is trained from the dataset using a learning formulation that makes it possible to train the classifier to reduce latency. The classifier is compared against both a Bag of Words and a Conditional Random Field classifier and is found to be superior in both pre-segmented and on-line classification tasks.

The effects of video-taped feedback on form, accuracy, and latency in an open and closed environment.

Abstract: 40 college women performed a modification of the classical fencing lunge against 2 laterally-arranged targets, under closed and open environmental conditions. Form (rating scale), accuracy (proximity to target center), and response latency were taken to measure the effects of video-taped feedback (VT). Administration of VT with specific instructions to direct S's attention to parts of the display resulted in closer approximation of the externally-imposed form, higher accuracy, and shorter response latency. Performing the skill in the closed environmental condition resulted in less deviation from the imposed form, higher accuracy scores, and longer response latency. No significant correlations were found between imposed form and accuracy.