Slow Responding Research Articles

A New Privacy-Preserving Scheme for Continuous Query in Location-Based Social Networking Services

With continuous queries that are used widely in location based mobile social networking services, how to protect the location privacy effectively for continuous query has been a hot topic for researchers. In this paper, we analyze the existing location privacy protection systems and algorithms for location based services; considering their disadvantages of slow responding time and high anonymization costs, we propose a new enhanced greedy cloaking algorithm which predicts a cloaking area at the initial query to be the cloaking region in the whole query lifetime by the comprehensive computation of privacy monitor, quality monitor, and dynamic adjuster. Privacy monitor and quality monitor charge the privacy protection level and service quality degree respectively; dynamic adjuster can adjust the cycle center point dynamically. We employ cycle as cloaking region form which can effectively alleviate the computation overhead. And we compare it with the earlier algorithm on three aspects. The experimental result shows that the enhanced greedy cloaking algorithm is better than the original greedy algorithm on average responding time or anonymization cost.

Research on flatness intelligent control via GA–PIDNN

The traditional flatness control methods have the problems of limited control accuracy, slow responding and difficultly establishing a precise mathematical model, in addition, the traditional BP optimal algorithm exists the shortage of easy trapped in local minimum, flatness intelligent control based on GA---PIDNN was proposed. PIDNN controller does not rely on the mathematical model of controlled object and has excellent characteristics in the control system. Genetic algorithm (GA) has good parallel design structure and characteristics of global optimization. Flatness recognition model and flatness predictive model are established via GA---PIDNN by combining the merits of GA and PIDNN, on this basis, for the 900HC reversible cold rolling mill, the GA---PIDNN controller was designed to control the flatness defects effectively. Through the comparative study of PIDNN optimized by BP optimal algorithm, the simulation results show that this control method can quickly track flatness target value, improve flatness control accuracy, achieve good control result, and it is an effective flatness control method.

Logarithmic decrease of serum alpha-fetoprotein or human chorionic gonadotropin in response to chemotherapy can distinguish a subgroup with better prognosis among highly malignant intracranial non-germinomatous germ cell tumors

Intracranial non-germinomatous germ cell tumors (NGGCTs) are a heterogeneous group of tumors. Although alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) are considered reliable markers for making diagnosis, the relationship between serum concentration of them and prognosis remains unclear. The present study investigated the decrease of serum tumor markers AFP and HCG as prognostic factors for patients with highly malignant NGGCTs. Eight consecutive patients with AFP>1000ng/ml or HCG>2000mIU/ml at initial treatments after January 2004 were retrospectively reviewed. Serum AFP or HCG concentration and tumor volume were sequentially measured during the therapeutic period. Six patients were treated by neoadjuvant chemotherapy consisting of ifosfamide, cisplatin, and etoposide, followed by salvage surgery and/or radiation therapy. A 14-year-old boy with choriocarcinoma and a 2-year-old boy with yolk sac tumor underwent radical resection because of acute hydrocephalus and mass effect on the brain stem, followed by chemotherapy and radiation therapy. Five patients showed complete response and survived at follow-up periods of 9, 26, 41, 63, and 75months, and the other three showed partial response but subsequent recurrence, finally died. Patients with complete response showed logarithmic decrease of serum AFP to the normal range in response to chemotherapy, but the others did not. Logarithmic decrease and normalization of serum AFP and HCG levels during neoadjuvant chemotherapy can distinguish a subgroup with better prognosis within highly malignant NGGCTs. To determine it, sequential measurement of serum tumor marker level was efficient. Outcomes were still dismal for slow responding patients, but this simple method may indicate more aggressive therapy.

C-reactive protein for discriminating treatment failure from slow responding pneumonia

Background The management of patients with community-acquired pneumonia (CAP) who fail to improve constitutes a challenge for clinicians. This study investigated the usefulness of C-reactive protein (CRP) changes in discriminating true treatment failure from slow response to treatment. Methods This prospective multicenter observational study investigated the behavior of plasma CRP levels on days 1 and 4 in hospitalized patients with CAP. We identified non-responding patients as those who had not reached clinical stability by day 4. Among them, true treatment failure and slow response situations were defined when initial therapy had to be changed or not after day 4 by attending clinicians, respectively. Results By day 4, 78 (27.4%) out of 285 patients had not reached clinical stability. Among them, 56 (71.8%) patients were cured without changes in initial therapy (mortality 0.0%), and in 22 (28.2%) patients, the initial empirical therapy needed to be changed (mortality 40.9%). By day 4, CRP levels fell in 52 (92.9%) slow responding and only in 7 (31.8%) late treatment failure patients (p < 0.001). A model developed including CRP behavior and respiratory rate at day 4 identified treatment failure patients with an area under the Receiver Operating Characteristic curve of 0.87 (CI 95%, 0.78–0.96). Conclusion Changes in CRP levels are useful to discriminate between true treatment failure and slow response to treatment and can help clinicians in management decisions when CAP patients fail to improve.

Meta-analysis Shows Extended Therapy Improves Response of Patients With Chronic Hepatitis C Virus Genotype 1 Infection

Clinical trials provided conflicting results about whether extended duration of treatment with pegylated interferon-alfa (pegIFN-alfa) and ribavirin (more than 48 weeks) improves rates of sustained virologic response (SVR) in patients infected with hepatitis C virus (HCV) genotype 1 and slow virologic response. We performed a meta-analysis to determine the overall impact of extended treatment, compared with standard treatment, on virologic response rates in these patients. We performed a literature search to identify randomized controlled trials (RCTs) that included monoinfected, treatment-naive patients infected with HCV genotype 1; data were compared between slow responding patients treated with pegIFN-alfa-2a/b plus ribavirin for 48 weeks and those that received extended treatment (as much as 72 weeks). End points included SVR rates, end-of-treatment (EOT) response and relapse rates; they were calculated according to the DerSimonian-Laird estimate. Six RCTs assessed the benefits of extended treatment with pegIFN-alfa-2a/b and ribavirin in treatment-naive patients with HCV genotype 1 that were slow responders (n = 669). The extended treatment significantly improved SVR rates in slow responders, compared with the standard of care (14.7% increase in overall SVR; 95% confidence interval, 4%-25.5%; P = .0072). Rates of viral relapse were significantly reduced by extended treatment, but EOT response rates were similar. The frequency of voluntary treatment discontinuation, but not of serious adverse events, was significantly increased by extended therapy. Extending the duration of treatment with pegIFN-alfa-2a/b and ribavirin in patients with HCV genotype 1 and a slow response to therapy improves the rate of SVR.

The effects of aging on the speed–accuracy compromise: Boundary optimality in the diffusion model.

We evaluated age-related differences in the optimality of decision boundary settings in a diffusion model analysis. In the model, the width of the decision boundary represents the amount of evidence that must accumulate in favor of a response alternative before a decision is made. Wide boundaries lead to slow but accurate responding, and narrow boundaries lead to fast but inaccurate responding. There is a single value of boundary separation that produces the most correct answers in a given period of time, and we refer to this value as the reward rate optimal boundary (RROB). We consistently found across a variety of decision tasks that older adults used boundaries that were much wider than the RROB value. Young adults used boundaries that were closer to the RROB value, although age differences in optimality were smaller with instructions emphasizing speed than with instructions emphasizing accuracy. Young adults adjusted their boundary settings to more closely approach the RROB value when they were provided with accuracy feedback and extensive practice. Older participants showed no evidence of making boundary adjustments in response to feedback or task practice, and they consistently used boundary separation values that produced accuracy levels that were near asymptote. Our results suggest that young adults attempt to balance speed and accuracy to achieve the most correct answers per unit time, whereas older adultts attempt to minimize errors even if they must respond quite slowly to do so.

Speeded verbal responding in adults who stutter: Are there deficits in linguistic encoding?

Linguistic encoding deficits in people who stutter (PWS, n = 18) were investigated using auditory priming during picture naming and word vs. non-word comparisons during choice and simple verbal reaction time (RT) tasks. During picture naming, PWS did not differ significantly from normally fluent speakers ( n = 18) in the magnitude of inhibition of RT from semantically related primes and the magnitude of facilitation from phonologically related primes. PWS also did not differ from controls in the degree to which words were faster than non-words during choice RT, although PWS were slower overall than controls. Simple RT showed no difference between groups, or between words and non-words, suggesting differences in speech initiation time do not explain the choice RT results. The findings are consistent with PWS not being deficient in the time course of lexical activation and selection, phonological encoding, and phonetic encoding. Potential deficits underlying slow choice RTs outside of linguistic encoding are discussed. Educational objectives: The reader will be able to (1) describe possible relationships between linguistic encoding processes and speech motor control difficulties in people who stutter; (2) explain the role of lexical priming tasks during speech production in evaluating the efficiency of linguistic encoding; (3) describe the different levels of processing that may be involved in slow verbal responding by people who stutter, and identify which levels could be involved based on the findings of the present study.

Fast responders have blinders on: ERP correlates of response inhibition in competition

Recent studies have demonstrated that individuals acting in a social context form shared representations, resulting in incorporating another person's action plan into their own. The present study investigated the extent to which shared representations are formed in a competitive task. Specifically, it was tested whether in competition the process of response inhibition is affected by explicit knowledge of another's task. Event-related potential (ERP) correlates of response inhibition were measured while pairs of participants competed with each other on a speeded go/no-go task. Participants were instructed to always try to respond faster than their direct competitor. No-go stimuli requiring an inhibitory response of the other person as well (compatible action) or no-go stimuli to which the other person should respond (incompatible action) were directly compared. Behavioral performance measures and response inhibition, as reflected in the no-go P3, were decreased on incompatible actions compared to compatible ones. Interestingly, both the behavioral and the ERP effects were caused by the slow responding and thus unsuccessful competitors. These findings indicate that shared representations are formed in competitive tasks, but differently for successful and unsuccessful competitors. Only the slow responders are impeded by incompatible actions. The present study therefore demonstrates that the formation of shared representations is not a fully automatic process. People can differ in the extent to which they incorporate the other's action plan into their own and this may be closely related to successful performance in competitive action.

Prevalencia y significado pronóstico de los marcadores mieloides en adultos con leucemia aguda linfoblástica de alto riesgo

The prognostic value of myeloid antigen expression in adult acute lymphoblastic leukemia (ALL) is controversial. The objective of this study was to evaluate the frequency and prognostic significance of myeloid antigen expression in adults with high risk ALL. Between June 1993 and July 2002, 222 adults patients with high-risk ALL were treated according to the PETHEMA LAL 93 protocol. The frequency of myeloid antigen expression, its association with other clinical and biologic variables and the prognostic significance in terms of complete remission (CR) rate, event free survival (EFS) and overall survival (OS) were analyzed. Myeloid antigen expression was present in 96 out of 222 patients (43%). No association was observed between myeloid antigen expression and the main clinical and biologic characteristics of ALL. Response to treatment was slower in patients expressing myeloid antigens, but no differences were found in CR achievement, EFS or OS. The probability of EFS at 10 years for ALL patients without and with myeloid antigen expression was 35% and 34%, respectively, while the probability of OS at 10 years was 30% and 33%, respectively. This absence of differences in EFS and OS probabilities was also observed when only slow responding patients were analyzed. In this study, myeloid antigen expression did not have prognostic influence in adult patients with high risk ALL.

MOTOR PREPARATION, MOTOR EXECUTION, ATTENTION, AND EXECUTIVE FUNCTIONS IN ATTENTION DEFICIT/HYPERACTIVITY DISORDER (ADHD)

Attention and executive functions were investigated in medicated and unmedicated children with ADHD combined type using a novel selective reaching task. This task involved responding as rapidly as possible to a target while at times having to ignore a distractor. Results indicated that unmedicated children with ADHD showed slow and inaccurate responding. Slow responding reflected problems at the stage of movement preparation but not movement execution. An attentional impairment, rather than a motor planning problem per se, appeared to underlie the slow movement preparation. Inaccurate responding reflected problems with response inhibition and selective attention, impulsivity, set-shifting, and difficulties in maintaining vigilance. Although medicated children with ADHD did not show slow movement preparation, they did show some response inaccuracy, resulting especially from impulsive responding.These findings suggest that ADHD is characterized by slow motor preparation (but not motor execution), and deficits in selective attention, vigilance, and executive functions. Preliminary results suggest that stimulant medication may resolve some of these motor, attentional and executive function deficits. We gratefully acknowledge the assistance of Claire Graham and Judy Matulick at Frankston Child and Adolescent Mental Health Service (Southern Health) in the recruitment of research participants. Many thanks also to Maree Farrow in the Psychology Department at Monash University and two anonymous reviewers for their helpful comments on this manuscript.

Vigilance in Schizophrenia and its Disruption by Impaired Preattentive Selection: A Dysintegration Hypothesis

Introduction : The study determined, simultaneously, whether major deficits of schizophrenia (sustained and selective attention, slow information processing, slow motor responding) are independent or related to each other. Methods : An auditory vigilance task (Pigache Attention Task, PAT) required a button-press to targets during four 5-minute subtests (slow diotic, fast diotic, slow dichotic, fast dichotic, analogous to four versions of the continuous performance test). Twenty schizophrenics on the first test-occasion of a double-blind, placebo controlled, crossover study were compared to 11 healthy subjects. Also, all 28 fortnightly testoccasions were analysed to quantify the schizophrenia deficits more precisely and the PAT was evaluated in a larger group of 86 healthy subjects. Results : Schizophrenics were significantly impaired on all task parameters versus healthy subjects. The patients' errors were independent and additive (grand mean components: basic task 36%, including a 9% time-on-task component; speed increment 26%; dichotic increment 38%). Errors, latencies, and psychosis severity were mutually correlated. Conclusions : The performance of all subjects confirmed a quantitative Vigilance Decision Model. The PAT impairments in schizophrenia suggested that rival options (e.g. thoughts) redeployed or suppressed attention away from the task, indicating a dysfunction of pre-attentive selection processes. Brain mechanisms are discussed and a new dys integration hypothesis of schizophrenia is proposed.

ABVD and Radiation Therapy as First-Line Treatment in Advanced Hodgkin's Disease

The purpose of this study was to evaluate the efficacy of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and radiotherapy in advanced Hodgkin's disease. In addition, to evaluate whether patients with slow responding tumors could profit from the early change of treatment regimen [MOPP (mechloretamine, vincristine, procarbazine, and prednisone)] followed by radiation therapy or autologous bone marrow transplantation (ABMT). Finally, to evaluate treatment options for patients with both early and late relapses. A total of 78 patients with previously untreated stages IIA bulky, IIB, III (A and B), and IV(A and B) Hodgkin's disease were treated with the ABVD regimen followed by radiotherapy. Patients with stages IIIB and IV (A and B) were re-staged after 4 ABVD courses of the treatment: slow responders (response less than 70%) underwent second-line treatment (MOPP) and eventually ABMT. Relapsed patients with a long initial complete response (≥ 12 months) were treated with second-line conventional treatment and those patients with a short initial complete response (< 12 months) underwent ABMT. The complete response (CR) rate was 91% after ABVD and radiation therapy. An additional 5 stage IIIB and IV patients whose therapy was switched after 4 cycles because of a slow response obtained a CR(3 after 2 MOPP courses plus radiotherapy and 2 after 2 MOPP courses followed by ABMT). Including these additional CRs, the overall CR rate was 97%. No episodes of clinical cardiopulmonary toxicity were observed. With a median follow-up time of 42 months, the 4-year relapse-free survival was 87%. The 4-year overall survival was 96%. Ten cases relapsed: all but one obtained a second CR with different approaches depending on the timing of relapse. The ABVD regimen appears to be effective and well tolerated confirming the validity of this four-drug regimen in the treatment of advanced Hodgkin's disease. In addition, therapeutic choices based on the timing of the relapse and the use of re-staging after 4 cycles in order to identify slow responders can play an important role in increasing the number of cured patients.

Arithmetical ability and disability in turner's syndrome: A cognitive neuropsychological analysis

Children with Turner's syndrome (TS), a sex chromosome abnormality in which the second X chromosome is abnormal or deleted, were given a series of tasks investigating mathematical skill, which were designed to assess the development of components of the model of arithmetic outlined by McCloskey, Caramazza, and Basili (1985), within which number processing skills (reading, writing, transcoding, and comprehending numbers) and calculation skills (including fact retrieval and the implementation of procedures) represent distinct modular components. The results indicated intact number processing skills in TS but an impaired calculation system. Within calculation, speed of retrieval of addition facts was impaired. These results cannot reflect generalized slow responding in TS, given Temple and Carney's (1996) recent finding of rapid rate of responding in TS when reading. Further impairments within the calculation system included enhanced rates of certain error types in the retrieval of multiplication facts. In solving arithmetical problems, participants with TS also made significantly more multiplication and division errors than did controls, and a significantly larger number of their errors had a basis in difficulty with the implementation of procedures. Thus, whereas the arithmetical disorder in TS selectively affects calculation rather than number processing, its effects within the calculation system are multiple. The results are compatible with the findings of Rovet, Szekely, and Hockenberry (1994) of poor procedural skills and poor fact retrieval on a timed task. They also tally with the evidence of Temple, Carney, and Mullarkey (1996) for impairment of components of executive skills in TS.

N-acetylglucosamine-containing muramyl peptides directly affect macrophages

In this study flow cytometry was used to show that macrophages were the major population of murine peritoneal exudate cells (MPEC), increasing la expression upon treatment with N-acetylglucosaminyl-β1-4- N-acetylmuramyl-alanyl- d-isoglutamine (GMDP). Modulation of la expression resulted from direct action of GMDP on macrophages, rather than from effect of cytokines released by T-cells. The effect of GMDP on two populations of macrophages, namely, slow and rapid responding, was studied in detail. Rapid responding cells were represented by la-positive macrophages: GMDP augmented their la expression. In contrast, slow responding subpopulation was represented by initially la-negative macrophages, in which GMDP induced de novo synthesis of Ia-antigens. The ability to induce Ia expression was also characteristic for other adjuvant-active N-acetylglucosamine-containing muramyl peptides (GMPs). Macrophages were shown to engulf GMPs by endocytosis. Activation of macrophages by GMDP resulted in an increase in their phagocytic activity.

Differential expression of glutathione S-transferase (GST) by adult Heligmosomoides polygyrus during primary infection in fast and slow responding hosts

Glutathione S-transferase (GST) specific enzymatic activity, assayed with the model substrate 1-chloro-2,4-dinitrobenzene, was 45% higher in adult Heligmosomoides polygyrus passaged through a slow responder mouse strain, C57 BL10 compared to worms passaged through a fast-responder strain (SWR × SJL) F 1. Western analysis using polyclonal antisera raised to purified H. polygyrus GSTs did not appear to positively correlate the expression of GST protein with functional enzymatic activity. However, western blotting did indicate a sex-linked expression pattern of GST protein, with male worms expressing a higher ratio of the 24 kDa to the 23 kDa GST family than female worms.

An early and transient period of protein synthesis is required for induction of neuropeptide Y-mRNA by phorbol ester and forskolin in aggregate cultures of fetal brain cells

We have previously shown that both forskolin (F) and phorbol ester (P) induce neuropeptide Y (NPY) production by aggregate cultures formed from dissociated fetal rat brains. In this study, we addressed the question: Do F/P induce NPY-mRNA in aggregate cultures and if so, does induction require active protein kinases and on-going protein synthesis? On Northern blots, the NPY cDNA hybridized to a single species of about 0.8 kb. F and P each induced a time-dependent increase in NPY-mRNA relative abundance, and this was inhibited by staurosporin, an inhibitor of both protein kinase A and C. Cycloheximide (CHX) inhibited F/P induction of mRNA in a time-dependent manner. When aggregates were incubated with F + P for a total 12 h period, CHX added along with F + P (0 h) completely inhibited, CHX added 1.5 h after F + P partially inhibited, and CHX added 6 h after F + P did not inhibit the increase in NPY-mRNA. To rule out the possibility that this inhibitory profile reflects toxicity of CHX, blots were re-hybridized with a SRIF cRNA probe and, as expected for SRIF gene, a 12 h exposure to CHX did not inhibit F + P induction of SRIF-mRNA. Close inspection of the blots (derived from 1.5% agarose gels) suggested the presence in F/P-treated aggregates of 2 species NPY-mRNA [ ≈ 0.75 and ≈ 0.85 kb, most likely differing in the length of poly(A) tail (Jamal et al., 1991)]; size-fractionation on a higher resolution gel (3% agarose) resolved the F/P induced mRNA into 2 distinct bands, while mRNA from untreated cultures migrated as a single band - the 0.75 kb. Thus, F and P each induces NPY-mRNA abundance in a process requiring protein synthesis and the activity of protein kinases. The fact that the requirement for protein synthesis is restricted to the early ( < 6 h) period of induction of mRNA is consistent with the involvement of immediate-early response genes and with the classification of NPY gene as a slow responding gene. The increase in NPY-mRNA abundance and the preferential induction of a larger molecular size NPY-mRNA suggests regulation of NPY expression at a transcriptional and a post-transcriptional level.

Dissociation of interference with the speed and accuracy of escape produced by inescapable shock.

Benzodiazepines and naltrexone administered before inescapable shock block behavioral consequences of the inescapable shock such as poor shuttle box escape, reduced activity in reaction to shock, reduced social interaction, and so on. Anxiogenic beta-carboline derivatives such as FG-7142 can produce these effects by themselves. In the present study, neither diazepam nor naltrexone had any effect on the interference with Y-maze choice escape accuracy produced by inescapable shock even though they both eliminated the reduction in Y-maze escape response speed produced by inescapable shock. Analogously, FG-1742 did not lead to a reduction in Y-maze choice escape response accuracy even though it did slow escape responding. These data imply that inescapable shock interferes with escape choice learning and escape response speed by different mechanisms, the former not involving fear-anxiety processes.

A vincristine-resistant murine erythroleukemia cell line secretes a differentiation enhancing factor

A clone of vincristine resistant murine erythroleukemia cells V3.17[44], characterized by high sensitivity to terminal erythroid differentiation induced by hexamethylene bisacetamide, secretes into the extracellular medium a protein factor which partially reduces the latent period before commitment and accelerates the expression of the terminal differentiated phenotype in a slow responding murine erythroleukemia N23 cell variant. This differentiation enhancing factor increases the rate of protein kinase C down-regulation which occurs at slower rate during cell differentiation. The activity of the factor is detected either by coculture of the two cell line variants or by addition of conditioned medium from V3.17[44] cells to a culture of N23 cells in the presence of the inducer. In addition to being secreted by V3.17[44] cells, this factor can also be detected in the cytoplasm of both V3.17[44] and N23 cells, associated with a particulate fraction from which it can be released by sonication.

Response tempo and separable--integral responding: evidence for an integral-to-separable processing sequence in visual perception.

Three experiments were conducted to examine the relation between response tempo and separable-integral responding. A restricted classification paradigm, in which similarity-based (integral) and dimensionally based (separable) classifications were pitted against one another, was used with the dimensions of length and density (all experiments) and size and brightness (Experiment 3). The subjects were college students (Experiments 1 and 2) and kindergarten, second-, and fifth-grade children (Experiment 3). In all three experiments, rapid responding was associated with fewer dimensional and more similarity responses than was slow responding. This result held when response tempo was simply measured (Experiments 1 and 3) and when it was manipulated by the experimenter (Experiment 2). The results were interpreted to be consistent with models of dimensional processing in which holistic, integral processing precedes analytic dimensional processing.

Adjustment of weanling and adolescent rats to a reward condition requiring slow responding.

The effects of a schedule of discontinuously negatively correlated reinforcement (DNC), in which only approach responses that take 5 sec or longer are reinforced, were studied in weanling rats that began training at 18 days of age and adolescents that began training at 60 days. Yoked partially reinforced subjects (PRF) received rewards on the same trials as corresponding DNC subjects of the same age, whereas continuously reinforced subjects (CRF) were rewarded on all trials. At the end of DNC training (210 trials), the older but not the younger DNC subjects were running slower than their yoked-PRF controls. The results are consistent with development of inhibition and suppression related to the developing brain, particularly the hippocampus.