Retrieval Delay Research Articles

Analysis of Current Situation of Medical Records Retrieval and Countermeasures

Objective. To strengthen the timely retrieval of medical records, give full play to the utility of medical record information, improve the management of the hospital and provide better service for the society. Methods. Calculating retrieval rate according to medical record collection, analyzing the cause of delay in medical record retrieval, and proposing improvement measures. Results. After the implementation of measures for collecting medical records, in the first quarter of 2013, the 2-day retrieval rate is 84.6% and the 7-day retrieval rate is 95.2%. As a result, the collection of medical records is improved greatly. Conclusion. All management levels at the hospital should attach great importance to medical records, establish a perfect medical record collection and a reward-punishment mechanism, and undertake effective supervision and management.

Minimizing delays in DNA retrieval: The “freezer method” for glass coverslip removal. Letter to the editor regarding comparative study of epidermal growth factor receptor mutation analysis on cytology smears and surgical pathology specimens from primary and metastatic lung carcinomas

Minimizing delays in DNA retrieval: The “freezer method” for glass coverslip removal. Letter to the editor regarding comparative study of epidermal growth factor receptor mutation analysis on cytology smears and surgical pathology specimens from primary and metastatic lung carcinomas

Retrieval practice is an efficient method of enhancing the retention of anatomy and physiology information

Although a great deal of empirical evidence has indicated that retrieval practice is an effective means of promoting learning and memory, very few studies have investigated the strategy in the context of an actual class. The primary purpose of this study was to determine if a series of very brief retrieval quizzes could significantly improve the retention of previously tested information throughout an anatomy and physiology course. A second purpose was to determine if there were any significant differences between expanding and uniform patterns of retrieval that followed a standardized initial retrieval delay. Anatomy and physiology students were assigned to either a control group or groups that were repeatedly prompted to retrieve a subset of previously tested course information via a series of quizzes that were administered on either an expanding or a uniform schedule. Each retrieval group completed a total of 10 retrieval quizzes, and the series of quizzes required (only) a total of 2 h to complete. Final retention of the exam subset material was assessed during the last week of the semester. There were no significant differences between the expanding and uniform retrieval groups, but both retained an average of 41% more of the subset material than did the control group (ANOVA, F = 129.8, P = 0.00, ηp(2) = 0.36). In conclusion, retrieval practice is a highly efficient and effective strategy for enhancing the retention of anatomy and physiology material.

Performance evaluation of In-Deep Class Storage for Flow-Rack AS/RS

This article presents a new storage-retrieval method called In-Deep Class Storage, designed for Flow-Rack AS/RS. Class-based storage is a well-known method that has an extensive literature; our method is based on the fact that it is more efficient to dedicate the front layers of each bin to the class of the most popular items rather than dedicating whole bins close to the drop-off station. Clearly, this idea is not trivial to implement due to the dynamic behaviour of such racks. Thus, two separate algorithms have been defined, one for storage and one for retrieval, enabling dynamic use of our approach, with the only hypothesis of a Pareto distribution of item demand. This article presents a simulation study designed to compare the performance of random storage and retrieval with the use of the algorithms. This study shows a significant improvement of the expected retrieval delay, the main performance indicator selected for the study.

A HARD REAL-TIME SCHEDULER ALGORITHM FOR SOLID STATE DEVICE

This paper presents an approach to use the solid state devices in hard real time application where delay in retrieval or write of data to and fro to them can result in a catastrophe. This new algorithm proposes a new approach of scheduling by considering the deadline’s associated with data’s, multiple synchronous read or write requests along with the algorithm for overcoming the problem of performing new block writes resulting in I/O bottleneck.

Ex Vivo Adenoviral Vector Gene Delivery Results in Decreased Vector-associated Inflammation Pre- and Post–lung Transplantation in the Pig

Acellular normothermic ex vivo lung perfusion (EVLP) is a novel method of donor lung preservation for transplantation. As cellular metabolism is preserved during perfusion, it represents a potential platform for effective gene transduction in donor lungs. We hypothesized that vector-associated inflammation would be reduced during ex vivo delivery due to isolation from the host immune system response. We compared ex vivo with in vivo intratracheal delivery of an E1-, E3-deleted adenoviral vector encoding either green fluorescent protein (GFP) or interleukin-10 (IL-10) to porcine lungs. Twelve hours after delivery, the lung was transplanted and the post-transplant function assessed. We identified significant transgene expression by 12 hours in both in vivo and ex vivo delivered groups. Lung function remained excellent in all ex vivo groups after viral vector delivery; however, as expected, lung function decreased in the in vivo delivered adenovirus vector encoding GFP (AdGFP) group with corresponding increases in IL-1β levels. Transplanted lung function was excellent in the ex vivo transduced lungs and inferior lung function was seen in the in vivo group after transplantation. In summary, ex vivo delivery of adenoviral gene therapy to the donor lung is superior to in vivo delivery in that it leads to less vector-associated inflammation and provides superior post-transplant lung function.

A Virtual-Ring-Based Data Storage and Retrieval Scheme in Wireless Sensor Networks

In-network data storage and retrieval is one of the most important problems in wireless sensor networks. Many schemes have been proposed to solve this problem. However, most of them do not take the frequencies of event and query into consideration. In fact, the frequencies of event and query are very important factors in real applications of in-network data storage and retrieval. In this paper, we introduce a virtual-ring-based data storage and retrieval scheme, which is called VRS, to solve the problem. VRS divides the whole sensor network field into some virtual rings. According to the frequencies, one of the virtual rings is selected out as the rendezvous ring, which plays the role of a bridge between the information consumers and the information producers. Extensive experiments have been done to evaluate the performance of the proposed scheme, VRS. Simulation results show that VRS outperforms the existing work in load balance, delay of data storage and retrieval, and the lifetime of the sensor networks.

SPR proxy mechanism for 3GPP Policy and Charging Control System

3GPP has standardized its Policy and Charging Control (PCC) system to provide dynamic policy control combined with real-time charging. The specific guidance on how PCC signaling delay can be reduced in session setup has not been explored in 3GPP standard. To bridge this gap, we propose an SPR proxy mechanism to shorten the PCC record retrieval delay which occurs between two PCC nodes: the Policy and Charging Rule Function (PCRF) and the Subscription Profile Repository (SPR). Our proposed SPR proxy is implemented at the PCRF to store the serving users’ PCC records retrieved from the SPR. Once the PCC records are updated by the subscribers, the SPR needs to refresh the SPR proxy in order to retain the record validity. If the PCC record updates in the SPR occur more frequently than the PCC record accesses performed by the PCRF, the SPR will generate many unnecessary refresh operations. The objective of this paper is to propose two delayed refresh schemes to be used alongside the SPR proxy for refresh suppression. Our schemes can dynamically adjust the delayed refresh timer according to the multi-user update rate of PCC records in the SPR. An analytical model and extensive simulation are developed to investigate the SPR proxy performance in terms of the proxy validity and the expected number of refreshes saved. Numerical results show that our SPR proxy mechanism with delayed refresh can significantly shorten the PCC-based session setup delay without significantly diminishing the proxy validity of PCC records.

Probing the Brain Substrates of Cognitive Processes Responsible for Context Effects on Recognition Memory

ABSTRACT Context effects on episodic recognition memory involve separable contributions of target-context binding, additive familiarity, and configural constancy. Here we examine whether these factors reflect contributions of processes attributed to different brain substrates. First, we challenged frontal and medial temporal lobe-based cognitive capacities in healthy young adults, employing divided attention tasks at encoding and retrieval, and extended retrieval delay, respectively. Target-context binding effects were specifically attenuated by delay, but not by divided attention. In a second experiment, older adults were identified by neuropsychological testing as having different levels of frontal and medial temporal lobe-dependent cognitive functions. Consistent with Experiment 1, older adults with low medial temporal lobe function exhibited reduced target-context binding effects, but levels of frontal function did not modulate binding effects. These findings indicate that unlike source memory, context effects on memory are associated with the integrity of medial temporal lobe-based processes but not with the integrity of frontal lobe-based processes. Our findings also emphasize the importance of discriminating between functional subgroups in the attempt to characterize memory processes in older adults.

Dissociating the “retrieval success” regions of the brain: Effects of retrieval delay

There is abundant evidence that the hippocampal formation critically supports episodic memory retrieval, the remembering of episodes including contextual details. Yet, a group of other brain regions has also been consistently implicated in successful episodic retrieval. This retrieval success network (RSN) includes the posterior midline region, medial prefrontal cortex (mPFC), and posterior parietal cortex (PPC). Despite these consistent findings, the functional roles of the RSN regions remain poorly understood. Given that vivid remembering leads to high-confidence retrieval decisions, it is unclear whether activity in these regions reflects episodic long-term memory, or is merely associated with retrieval confidence. In order to distinguish between these alternatives, we manipulated study-test delays within the context of a continuous recognition task during fMRI-scanning. The design was based on previous evidence indicating that retrieval at short delays is easier leading to high-evidence mnemonic decisions, whereas retrieval at longer delays is more difficult but also more hippocampus-dependent. Confirming previous findings, we found that retrieval decisions at short delays were more accurate and faster, and that the hippocampus showed greater activity at longer delays. Within the other RSN regions, we found three distinct activation patterns as a function of delay. Similar to the hippocampus, the retrosplenial cortex showed increased activity as a function of retrieval delay. Dorsal PPC and the precuneus showed decreased activity. Finally, the posterior cingulate, medial PFC and ventral PPC showed a V-shaped pattern. These findings support the idea that dorsal PPC and the precuneus are involved in decision-related retrieval processes rather than successful remembering.

Local Gene Transfer and Expression Following Intramuscular Administration of FGF-1 Plasmid DNA in Patients With Critical Limb Ischemia

NV1FGF is an expression plasmid encoding sp.FGF-1(21-154) currently under investigation for therapeutic angiogenesis in clinical trials. NV1FGF plasmid distribution and transgene expression following intramuscular (IM) injection in patients is unknown. The study involved six patients with chronic critical limb ischemia (CLI) planned to undergo amputation. A total dose of 0.5, 2, or 4 mg NV1FGF was administered as eight IM injections (0.006, 0.25, or 0.5 mg per injection) 3-5 days before amputation. Injected sites (30 cm(3)) were divided into equally sized smaller pieces to assess spatial distribution of NV1FGF sequences (PCR), NV1FGF mRNA (reverse transcriptase-PCR), and fibroblast growth factor-1 (FGF-1)-expressing cells (immunohistochemistry). Data indicated gene expression at all doses. The distribution area was within 5-12 cm for NV1FGF sequences containing the expression cassette, up to 5 cm for NV1FGF mRNA, and up to 3 cm for FGF-1-expressing myofibers. All FGF receptors were detected indicating robust potential for bioactivity after NV1FGF gene transfer. Circulating levels of NV1FGF sequences were shown to decrease within days after injection. Data support demonstration of plasmid-mediated gene transfer and expression in muscles from patients with CLI. FGF-1 expression was shown to be limited to injection sites, which supports the concept of multiple-site injection for therapeutic use.

The Sun Health Research Institute Brain Donation Program: Description and Eexperience, 1987–2007

The Brain Donation Program at Sun Health Research Institute has been in continual operation since 1987, with over 1000 brains banked. The population studied primarily resides in the retirement communities of northwest metropolitan Phoenix, Arizona. The Institute is affiliated with Sun Health, a nonprofit community-owned and operated health care provider. Subjects are enrolled prospectively to allow standardized clinical assessments during life. Funding comes primarily from competitive grants. The Program has made short postmortem brain retrieval a priority, with a 2.75-h median postmortem interval for the entire collection. This maximizes the utility of the resource for molecular studies; frozen tissue from approximately 82% of all cases is suitable for RNA studies. Studies performed in-house have shown that, even with very short postmortem intervals, increasing delays in brain retrieval adversely affect RNA integrity and that cerebrospinal fluid pH increases with postmortem interval but does not predict tissue viability.

The Displaced Lower Third Molar: A Literature Review and Suggestions for Management

To review the literature associated with displaced lower third molars, to introduce a modified method of retrieval of an accidentally displaced lower third molar tooth or root fragment, and to recommend rational guidelines for management. A review of the literature was performed to record the types of displacements, patient's personal data, imaging used, and the surgical approaches with their complications. A modified technique for exploration and retrieval is described. Nineteen reports were identified and reviewed. Some others could not be translated. In the 32 cases reviewed, there were no gender differences and the third and fourth decades of life were the most common time for this mishap to occur. Fragments were displaced into 5 different tissue spaces. The size of the fragments varied, but the whole tooth and fragment were displaced with equal frequency. Different methods of recovery were used. The accidental displacement of a lower third molar during attempted extraction is a rare but potentially serious complication. Retrieval should be effected as soon as possible. Because of differences in the direction of displacement, the size of fragment, delay in retrieval, and tissue reactions, no one technique is uniformly applicable. The modified method we suggest appears to save time and have few complications.

Microtubule depolymerization can drive poleward chromosome motion in fission yeast

Prometaphase kinetochores interact with spindle microtubules (MTs) to establish chromosome bi-orientation. Before becoming bi-oriented, chromosomes frequently exhibit poleward movements (P-movements), which are commonly attributed to minus end-directed, MT-dependent motors. In fission yeast there are three such motors: dynein and two kinesin-14s, Pkl1p and Klp2p. None of these enzymes is essential for viability, and even the triple deletion grows well. This might be due to the fact that yeasts kinetochores are normally juxtapolar at mitosis onset, removing the need for poleward chromosome movement during prometaphase. Anaphase P-movement might also be dispensable in a spindle that elongates significantly. To test this supposition, we have analyzed kinetochore dynamics in cells whose kinetochore-pole connections have been dispersed. In cells recovering from this condition, the maximum rate of poleward kinetochore movement was unaffected by the deletion of any or all of these motors, strongly suggesting that other factors, like MT depolymerization, can cause such movements in vivo. However, Klp2p, which localizes to kinetochores, contributed to the effectiveness of P-movement by promoting the shortening of kinetochore fibers.

A Predictive Model for Web Prefetching

A prefetching strategy can help individuals more effectively to reduce the perceived access delay in Web information retrieval. Some prefetching algorithms have been proposed in literatures, but previous results show the ability is limited. This paper proposes an approach on predictive prefetching, which consists of an adaptive session generation method to extract navigational behaviors from Web log and a session-tree framework to organize sessions for fast retrieval. We first present a method to segment historical information of individuals' browsing behaviors into sessions based on time gap and session similarity. Session-tree is then built from these sessions. It enables us to organize historical information easily and retrieve subsequences both by events and timestamps efficiently. On the basis of these mechanisms, we predict individuals' coming requests and prefetch some results. Further, the experimental comparison with the standard PPM algorithm is also present. Through analyzing experimental results based on a real stock data set, we conclude the performance based on the adaptive session generation and the session-tree framework can predict well.

Predictive buffer control in delivering remotely stored video using proxy servers

We study the problem of using proxy servers to stream video stored at a geographically separate location. The separation of the server and the storage introduces a non-negligible delay in retrieving video frames in real time. We assume an additive-increase/multiplicative-decrease transport protocol to support the streaming process and develop an effective scheme to achieve consistent, high streaming quality. The heart of the scheme is the control of buffer occupancy at the proxy server. We model the buffer as a bilinear dynamical system disturbed by a point process with stochastic state-dependent intensity. We first develop a buffer controller that does not exploit this model. Then, using the buffer model, we construct a second controller based on an optimal-control analysis for the case without retrieval delay. Extending these two controllers, we subsequently synthesize two controllers based on prediction of future system states using the model, taking into account both the delay and the state-dependent disturbance intensity. Our empirical study illustrates the effectiveness of the streaming scheme. We further find that the controllers exploiting the buffer model demonstrate performance significantly superior to that of the model-free controller in overcoming the adverse impact of the retrieval delay. We also conduct limited experiments to study the impact of variable retrieval delays.

Retrieval Protracts Deferred Imitation by 6-Month-Olds.

Past research using a deferred imitation task has shown that 6-month-olds remember a 3-part action sequence for only 1 day. The concept of a time window suggests that there is a limited period within which additional information can be integrated with a prior memory. Its width tracks the forgetting function of the memory. This study asked if retrieving the memory of the modeled actions at the end of the time window protracts its retention, if the type of retrieval (active or passive) differentially influences retention, and if the retrieval delay influences its specificity. In Experiment 1, 6-month-olds either imitated the modeled actions (active retrieval group) or merely watched them modeled again (passive retrieval group) 1 day after the original demonstration. Both groups showed deferred imitation after 10 days. In Experiment 2, 6-month-olds who repeatedly retrieved the memory at or near the end of the time window deferred imitation for 2.5 months. In Experiment 3,6-month-olds spontaneously generalized imitation late in the time window after 1 prior retrieval, whether it was active or passive. These studies reveal that the retention benefit of multiple retrievals late in the time window is huge. Because most retrievals are undoubtedly latent, the contribution of repeated events to the growth of the knowledge base early in infancy has been greatly underestimated.

Performance evaluation of an optimal cache replacement policy for wireless data dissemination

Data caching at mobile clients is an important technique for improving the performance of wireless data dissemination systems. However, variable data sizes, data updates, limited client resources, and frequent client disconnections make cache management a challenge. We propose a gain-based cache replacement policy, Min-SAUD, for wireless data dissemination when cache consistency must be enforced before a cached item is used. Min-SAUD considers several factors that affect cache performance, namely, access probability, update frequency, data size, retrieval delay, and cache validation cost. The paper employs stretch as the major performance metric since it accounts for the data service time and, thus, is fair when items have different sizes. We prove that Min-SAUD achieves optimal stretch under some standard assumptions. Moreover, a series of simulation experiments have been conducted to thoroughly evaluate the performance of Min-SAUD under various system configurations. The simulation results show that, in most cases, the Min-SAUD replacement policy substantially outperforms two existing policies, namely, LRU and SAIU.

The optimal retrieval start times of media objects for the multimedia presentation

We design the Multimedia Presentation Coordinator (MPC) to guarantee the precise presentation relation and presentation time on a storage-based multimedia presentation system. After determining the optimal retrieval start times of media objects to be presented, the MPC performs an instant scheduling and a buffer management algorithm during the actual presentation. The instant scheduling reduces synchronization breaks due to unexpected retrieval delays during the presentation. The buffer management algorithm schedules the buffer releasing times of media objects. The evaluation results show that the MPC provides much less presentation delay and less number of synchronization breaks during the presentation than other schemes.

Interaction of Stoned and Synaptotagmin in Synaptic Vesicle Endocytosis

The Drosophila dicistronic stoned locus encodes two distinctive presynaptic proteins, Stoned A (STNA) and Stoned B (STNB); STNA is a novel protein without homology to known synaptic proteins, and STNB contains a domain with homology to the endocytotic protein AP50. Both Stoned proteins colocalize precisely with endocytotic proteins including the AP2 complex and Dynamin in the "lattice network" characteristic of endocytotic domains in Drosophila presynaptic terminals. FM1-43 dye uptake studies in stoned mutants demonstrate a striking decrease in the size of the endo-exo-cycling synaptic vesicle pool and loss of spatial regulation of the vesicular recycling intermediates. Mutant synapses display a significant delay in vesicular membrane retrieval after depolarization and neurotransmitter release. These studies suggest that the Stoned proteins play a role in mediating synaptic vesicle endocytosis. We have documented previously a highly specific synaptic mislocalization and degradation of Synaptotagmin I in stoned mutants. Here we show that transgenic overexpression of Synaptotagmin I rescues stoned embryonic lethality and restores endocytotic recycling to normal levels. Furthermore, overexpression of Synaptotagmin I in otherwise wild-type animals results in increased synaptic dye uptake, indicating that Synaptotagmin I directly regulates the endo-exo-cycling synaptic vesicle pool size. In parallel with recent biochemical studies, this genetic analysis strongly suggests that Stoned proteins regulate the AP2-Synaptotagmin I interaction during synaptic vesicle endocytosis. We conclude that Stoned proteins control synaptic transmission strength by mediating the retrieval of Synaptotagmin I from the plasma membrane.