Finite-state Markov modeling of correlated Rician-fading channels

Stochastic properties of the binary channel that describe the successes and failures of the transmission of a modulated signal over a time-correlated flat-fading channel are considered for investigation. This analysis is employed to develop Kth-order Markov models for such a burst channel. The order of the Markov model that generates accurate analytical models is estimated for a broad range of fading environments. The parameterization and accuracy of an important class of hidden Markov models, known as the Gilbert-Elliott channel (GEC), are also investigated. Fading rates are identified in which the Kth-order Markov model and the GEC model approximate the fading channel with similar accuracy. The latter model is useful for approximating slowly fading processes, since it provides a more compact parameterization.     

Analyse der verschiedenen Einflüsse auf die Kaltwalzbarkeit von FeSi-Legierungen

Bekanntlich steigt die Kaltsprödigkeit von FeSi-Legierungen mit dem Si-Gehalt, was die technische Nutzbarkeit auf Legierungen mit weniger als etwa 3,5% Si beschränkt. In dieser Arbeit werden die Einflüsse auf die Kaltsprödigkeit untersucht und im einzelnen die folgenden Gefügeparameter untersucht: Legierungszusammensetzung, Korngröße, Ordnungszustand.     

State anxiety and ambulatory blood pressure following resistance exercise in females

The purpose of this investigation was to examine state anxiety and blood pressure responses during ambulatory recovery from resistance exercise. Fourteen females completed three separate bouts of resistance exercise in which the sets (N = 3), repetitions (N = 10), exercise type (knee extension, knee flexion, arm pull down, chest press, shoulder press, and abdominal curl), and time (30 min) were held constant, but the intensity was manipulated to equal 40%, 60%, and 80% of the 10-repetition maximum for each exercise. Immediately before as well as 1, 15, 30, 45, 60, 75, 90, 105, and 120 min following the cessation of exercise blood pressure and heart rate were assessed. State anxiety assessments were initiated immediately following blood pressure measurements. The subjects were ambulatory during the post-exercise period, and information about body posture during the cardiovascular assessments was obtained. MANOVAs, ANOVAs, and Tukey tests revealed that post-exercise state anxiety levels were reduced compared with pre-exercise values from 90 to 120 min following exercise. Systolic blood pressure was elevated at 1 and 15 min following the 80% intensity condition, and at 1 min following the 60% intensity condition. It is concluded that during ambulatory recovery from resistance exercise: 1) reductions in state anxiety are realized; and 2) systolic blood pressure, in contrast to what has been shown to occur following aerobic exercise, is not reduced.     

Acquisition and reversal of taste/tactile discrimination after forebrain noradrenaline depletion.

Assessed the role of noradrenaline (NA) on the acquisition of an aversively motivated discrimination task and its reversal. A conditioned taste aversion procedure was used. NA depletions were achieved through 2 pharmacological means: systemic N-2 chloroethyl-N-ethyl-2-bromo-benzylamine (DSP4) and destruction of the dorsal noradrenergic bundle (DNAB) with 6-hydroxydopamine (6-OHDA). Both procedures caused marked reductions of NA in the frontal cortex and hippocampus. In neither of the studies (Exp 1, DSP4 and Exp 2, DNAB) were there any significant changes between controls and NA-depleted rats in either the rate of acquisition of the original discrimination (Phase 1) or the subsequent reversal (Phase 2). This occurred irrespective of which of the 2 stimuli (a taste cue or a tongue-tactile cue) initially was used as the conditioned stimulus/stimuli (CS) (the stimulus first followed by contingent administration of lithium chloride and later, by saline injections). Thus NA does not appear to be critically involved in the acquisition and reversal of a taste/tactile discrimination task. The significance of forebrain NA for other discrimination tasks is discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Pharmacokinetic-pharmacodynamic analysis of changrolin in dogs with arrhythmia

The pharmacokinetics and pharmacodynamics of changrolin (CRL) were studied in 7 dogs with arrhythmia induced by coronary artery ligature. The ECG and the percentage of reduction ratio of ventricular premature were used to evaluate the effect of CRL, and an HPLC method was used to determine the serum drug concentration. A pharmacokinetic program was used to fit concentration-time (C-T) data and a combined pharmacokinetic-pharmacodynamic model was used to analyze effect-time (E-T) data in individual dogs. After infusion with CRL 83.33 micrograms.kg-1.min-1 for 60 min, it was found that K10, T1/2, Vd, Cl and Ce were 0.0087 min-1, 78.03 min, 40.55 ml.kg-1, 0.42 ml.kg-1.min-1, and 2.01 micrograms.ml-1, respectively.     

白音查干凹陷下白垩统储层微观特征

利用各种分析化验方法，对白音查干凹陷下白垩统储层特征进行了研究，主要对储层的岩矿特征，以及储层在纵向和平面上的变化作了研究，对储层的母岩及物源方向进行推断，对勘探开发具有一定的指导意义。     

Comparison of percent free prostate specific antigen and prostate specific antigen density as methods to enhance prostate specific antigen specificity in early prostate cancer detection in men with normal rectal examination and prostate specific antigen between 4.1 and 10 ng./ml

PURPOSE: We analyzed the behavior of prostate specific antigen (PSA) density and percent free PSA to enhance the specificity of PSA in the early diagnosis of prostate cancer in men with normal digital rectal examination and PSA serum level between 4.1 and 10 ng./ml. MATERIALS AND METHODS: PSA serum level, PSA density and percent free PSA were analyzed in 74 men with normal digital rectal examination and PSA serum level between 4.1 and 10 ng./ml. All men underwent systematic prostate biopsy, and the diagnosis was benign prostate hyperplasia in 52 and prostate cancer in 22. Furthermore, we determined the decrease in unnecessary biopsies and the cancer detection rate using 0.10 versus 0.15 as cut points for PSA density, and 20 versus 25 as cut points for percent free PSA. RESULTS: In patients with benign prostatic hyperplasia and prostate cancer, respectively, the median PSA level was 6.7 and 7.0 ng./ml. (p > 0.05), median prostate volume was 50 and 37 cc (p < 0.04), median PSA density was 0.14 and 0.19 (p < 0.007) and median percent free PSA was 18.9 and 10.1 (p < 0.005). Using PSA density cut points of 0.15 and 0.10, the decrease in negative biopsies was 53.8 and 36.5% with a sensitivity of 86.4 and 90.9%, respectively. However, using percent free PSA cut points of 20 and 25, the decrease in negative biopsies was 36.5 and 26.9% with a sensitivity of 77.3 and 95.5%, respectively. CONCLUSIONS: Although both methods could minimize unnecessary biopsies in men with normal digital rectal examination and PSA serum level between 4.1 and 10 ng./ml., the percent free PSA was more cost-effective since transrectal ultrasound was not required. In this small series of symptomatic patients a percent free PSA cut point of 25 could detect at least 95% of prostate cancers and decrease 26.9% of negative biopsies.