Auxiliary Tests Research Articles

Low Cost Simulation of PLC Programs

The paper discusses the conversion of PLC (programmable logical controller) programs into forms suitable for their emulation by any software tool that includes some programming language capable of evaluating mathematical formulas, if-then instructions, and time tests, in the case of timers. The method offers advantage of low cost portability into a whole range of environments because it does not require the embodiment of large additional programming support for the simulation of various PLC instructions. The conversion, either of whole PLC program or its part, can also be utilized for auxiliary tests when a finished PLC program is transformed into a new hardware.

Bootstrapping the conditional moment test for parametric duration models

The performance of auxiliary regression-based specification tests for parametric duration models estimated with censored data is evaluated. The test using asymptotic critical values has poor size. Bootstrapping corrects the size problem but results in a biased power curve.

Ownership Structure and Firm Performance: Evidence from Taiwan

This paper examines the relationship between firm performance and ownership structure for listed and OTC manufacturing firms in Taiwan. By classifying ownership into three categories (managerial owners, institutional owners and the control group), the study addresses two related empirical issues-the commonly examined piecewise and the Granger causality relationships between ownership and performance. The empirical results show that except managerial ownership, there is a positive relationship between ownership and performance. Meanwhile, the piecewise relationship surfaces only for the control group, with the inflection points of 12.5% and 20%. The Granger causality test demonstrates a significant feedback relationship between institutional ownership and performance, consistent with the better expertise of institutional owners in monitoring and investment selection. Firm performance Granger-causes the ownership of the control group and is independent of managerial ownership. As auxiliary tests, this study provides a formal approach to search for inflection points and reconcile different firm performance measures.

Estimation of Point and Diffuse Contaminant Loads to Streams by Non-Parametric Regression Analysis of Monitoring Data

In this study, point and diffuse contaminant loads to a stream are estimated using stream monitoring data. Regression analysis is conducted to separate point source loads and background contaminant loads using water quality and flow time series. Non-parametric methods are utilized for regression and auxiliary statistical tests to eliminate the effects of outliers in the data and to avoid restrictions posed by assumptions of normality. Point source loads and background concentrations are estimated directly by regression of data from a station. A second station is needed to estimate diffuse load contributions. The method is exemplified using data from a polluted stream in Turkey, the Porsuk Stream. Point and diffuse loads are estimated for six water quality parameters, chloride, dissolved solids, ammonia, nitrate, biochemical oxygen demand and total phosphorus. It is found that for many water quality parameters, contaminant loads to a stream can be estimated with reasonable accuracy.

Bootstrapping the Conditional Moment Test for Parametric Duration Models

This letter evaluates the performance of auxiliary regression-based specification tests for parametric duration models estimated with censored data. The test using asymptotic critical values has poor size. Bootstrapping corrects the size problem but results in a biased power curve.

Baseline information in structural failure time estimators for the effect of observed treatment compliance.

Structural accelerated failure time models allow expression of the effect of treatment actually received in placebo-controlled randomized trials with non-compliance. Without further assumptions, the structural parameter is typically estimated via a series of auxiliary logrank tests, searching for the structural parameter that back-transforms treated survival times to latent treatment-free survival times which are equally distributed between randomized arms. In this paper we investigate to what extent score tests involving baseline covariates provide more powerful auxiliary tests and lead to more precise estimates of the structural parameter without compromising the alpha-level. We propose a set of estimating equations which combines score components for covariate effects based on the control arm only, with a log-likelihood score for treatment effect based on both arms. Analytic results for exponential models as well as simulation studies for the semi-parametric approach indicate that in many practical situations this incorporation of baseline covariates leads to more precise estimators of the structural effect. Relative efficiency is shown to depend on the selective nature of compliance. In a leukaemia trial we find the length of the 95 per cent confidence interval for the structural parameter is reduced to two-thirds of the original length by incorporating baseline covariates in this way.

Environmental photodegradation of pyrimidine fungicides — Kinetics of the visible-light-promoted interactions between riboflavin and 2-amino-4-hydroxy-6-methylpyrimidine

To clarify the evolution of pyrimidine fungicides under natural aquatic environmental conditions, the visible-light-promoted degradation of the model fungicide 2-amino-4-hydroxy-6-methylpyrimidine (AHMPD) has been studied in air-equilibrated pH 6 aqueous solutions in the presence of riboflavin (Rf), employing time-resolved and stationary kinetic–spectroscopic methods. AHMPD, a compound practically inert towards the attack of singlet molecular oxygen (O2(1Δg)), quenches excited singlet and triplet states of Rf with rate constants of 2.7 × 109 M–1 s–1 and 2.7 × 107 M–1 s–1, respectively. In the presence of AHMPD, the photodecomposition of Rf, which occurs from the excited triplet state of the pigment, depends on the concentration of the fungicide: at [Formula: see text]40–50 mM a limited photochemistry occurs due to the quenching of excited singlet Rf, while at ca. 5–10 mM triplet Rf is largely photogenerated and subsequently quenched either by oxygen, giving rise to O2(1Δg), or by AHMPD, yielding semireduced Rf through an electron transfer process. Flash photolysis experiments and indirect auxiliary tests confirm the presence of superoxide anion generated by the reaction of Rf anion radical with the dissolved oxygen. The neat result of this intricate scheme of competitive reactions is the photodegradation of both AHMPD and Rf, mainly through a superoxide anion-mediated oxidation, although some contribution of O2(1Δg)-mediated photooxidations cannot be disregarded.Key words: photooxidation, pyrimidine derivatives, riboflavin, singlet molecular oxygen, superoxide anion.

Mass measurements of few-electron systems in Penning traps

The accuracy of the SMILETRAP mass spectrometer has been verified by a number of mass comparisons involving well-known masses. Our results for H2 +,Ne6+,Ne9+ ,10+,Si12+ ,13+ ,14+,and Ar14+ ,16+ all agree within the statistical errors (0.3–1 ppb) with previous determinations. However, all measurements involving He give a deviation. The combined He1+,2+ data results in a mass deviation of +1.9 ±0.23 ppb. The uncertainty of the accepted He mass is 0.25 ppb, thus this represents a significant deviation. High statistics comparisons (statistical uncertainty <0.5 × 10-9utilizing different species (excluding He) and charge states agree within ±0.5 ppb. An analysis estimating the contribution from individual systematic error sources and other auxiliary tests does not allow a systematic error larger than ± 0.85 ppb. We conclude that for now we cannot rule out the presence of an unknown systematic error which in the He comparison results in a near 2 ppb deviation. Thus, as a safety measure we should exclude the He data when calculating the proton mass. The He discrepancy also forces us to give a larger limit of the systematic error of the proton mass than motivated by high statistics comparisons. However, due to the consistency of all other measurements and tests, it appears unlikely that this deviation should be present to the same extent in other comparisons. Thus, for now, after a preliminary analysis we report a proton mass = 1.007 276 466 72 ± 16 ± 85 u, where the errors are the weighted statistical errors and the estimated maximal systematical error, respectively. After a complete analysis we expect the systematic error to be reduced below ±0.5 ppb.

Neurologic disorders in 203 consecutive patients with small cell lung cancer: Results of a longitudinal study

Neurologic complications of small cell lung cancer (SCLC) are manifold. The incidence and course of the various metastatic and nonmetastatic neurologic disorders were studied prospectively in a cohort of SCLC patients. The 203 patients underwent neurologic examinations on a regular basis, prior to therapy, during and after treatment, from 1983 through 1994. Routine computer tomography or magnetic resonance imaging of the brain was performed before therapy and after 2 years' survival. Other auxiliary diagnostic tests were performed as required. The majority of the 174 neurologic disorders, diagnosed in 132 patients, were associated with metastases. A total of 79 patients developed brain metastases. The cumulative risk of brain metastases reached 47% for limited and 69% for extensive disease patients at 2 years from diagnosis. Survival following the diagnosis of brain metastases was significantly longer for patients with brain metastases at the initial diagnosis of SCLC than for patients with delayed brain metastases (P < 0.01, long rank test). The most frequent paraneoplastic syndrome with neurologic symptoms was that of inappropriate secretion of antidiuretic hormone (SIADH), which was diagnosed in 11 patients. Antibody-mediated paraneoplastic neurologic syndromes were diagnosed in five patients. Chemotherapy for SCLC caused SIADH to subside in most patients. In contrast, the antibody-mediated syndromes did not respond to SCLC therapy. Adverse effects of treatment included peripheral neuropathy, encephalopathy, radiation plexopathy, and steroid myopathy. However, unlike the other complications, peripheral neuropathy was reversible. This clinical investigation confirmed the frequency of central nervous system metastatic involvement as well as the diversity of the neurologic complications in SCLC. The high frequency of brain metastases justifies a reappraisal of prophylactic cranial irradiation in this patient group.

Neurologic disorders in 203 consecutive patients with small cell lung cancer: Results of a longitudinal study

BACKGROUND Neurologic complications of small cell lung cancer (SCLC) are manifold. The incidence and course of the various metastatic and nonmetastatic neurologic disorders were studied prospectively in a cohort of SCLC patients. METHODS The 203 patients underwent neurologic examinations on a regular basis, prior to therapy, during, and after treatment, from 1983 through 1994. Routine computer tomography or magnetic resonance imaging of the brain was performed before therapy and after 2 years' survival. Other auxiliary diagnostic tests were performed as required. RESULTS The majority of the 174 neurologic disorders, diagnosed in 132 patients, were associated with metastases. A total of 79 patients developed brain metastases. The cumulative risk of brain metastases reached 47% for limited and 69% for extensive disease patients at 2 years from diagnosis. Survival following the diagnosis of brain metastases was significantly longer for patients with brain metastases at the initial diagnosis of SCLC than for patients with delayed brain metastases (P < 0.01, log rank test). The most frequent paraneoplastic syndrome with neurologic symptoms was that of inappropriate secretion of antidiuretic hormone (SIADH), which was diagnosed in 11 patients. Antibody-mediated paraneoplastic neurologic syndromes were diagnosed in five patients. Chemotherapy for SCLC caused SIADH to subside in most patients. In contrast, the antibody-mediated syndromes did not respond to SCLC therapy. Adverse effects of treatment included peripheral neuropathy, encephalopathy, radiation plexopathy, and steroid myopathy. However, unlike the other complications, peripheral neuropathy was reversible. CONCLUSIONS This clinical investigation confirmed the frequency of central nervous system metastatic involvement as well as the diversity of the neurologic complications in SCLC. The high frequency of brain metastases justifies a reappraisal of prophylactic cranial irradiation in this patient group. Cancer 1996; 77:1434-41.

Evaluation of Long-Term Results of Surgical Correction of Stress Urinary Incontinence

A total of 109 patients submitted to surgery for the correction of urinary stress incontinence (USI) by two different techniques, i.e. anterior colporrhaphy (group I, n = 57) when cystocele grade II/III was present, and Burch procedure (group II, n = 52) when cystocele grade I was present, were reevaluated an average of 5 years after surgery (range: 54-66 months). The curve constructed with the reevaluation data showed a sharp superiority of the Burch technique in terms of correction of USI and associated genital prolapses. There was a progressive recurrence rate that stabilized at 5 years, with values of 78.9% in group I and 40% in group II. Anterior colporrhaphy was ineffective for the correction of any of these parameters in group I. The data clearly show the need to improve the presurgical diagnostic methods for the selection of patients that will benefit from treatment: detailed history of the current disease and auxiliary tests such as Q-tip test, transvaginal ultrasound, and urodynamic study. Other factors were associated with ineffective treatment in both groups, such as hypoestrogenism (20/109), excessive weight gain (19/109) and chronic intestinal constipation and/or coughing present in 36 patients, with recurrence in 28 of them.

Schizophrenia and autoimmunity--a possible etiological mechanism?

Schizophrenia is a chronic disease which begins during early adulthood and persists throughout life. It may appear in two main clinical patterns: chronic progressive and relapsing-remitting. The diagnosis is based entirely on clinical data, as no auxiliary laboratory tests are available. Schizophrenia has a heterogeneous clinical expression which may reflect different etiological factors, such as genetic susceptibility, dysfunction of different neurotransmitter systems or environmental, stressogenic and interfamilial influences. Recently, an autoimmune hypothesis has gained acceptance, which proposes that schizophrenia is one of a spectrum of neuropsychiatric diseases in which an autoimmune attack on the brain occurs. It is also possible, however, that the immunological changes seen in schizophrenic patients are secondary to the disease itself. The main evidence supporting an autoimmune hypothesis is the presence of immunological alterations in schizophrenia that also occur in other autoimmune diseases, e.g. an elevation in serum immunoglobulin levels, a decrease in mitogen responses, morphologically abnormal lymphocytes, an increase in antibrain antibodies, an increase in antibodies to nuclear factor, and a decrease in CD4+ T cells. An autoimmune etiology, if proven correct in the pathogenesis of schizophrenia, would have potential implications for the direction of future psychopharmacological therapies.

Plasma intestinal alkaline phosphatase isoenzymes in neonates with bowel necrosis.

To determine if the intestinal isoenzymes of alkaline phosphatase (ALP) are biochemical markers of bowel necrosis in neonates. Plasma ALP isoenzymes were measured in 22 babies with bowel necrosis, histologically confirmed, and in 22 matched controls. The isoenzymes were also measured in 16 infants with signs of necrotising enterocolitis, who recovered without histological confirmation of bowel necrosis. The isoenzymes were separated by polyacrylamide gel electrophoresis. Auxiliary tests for identification included neuraminidase digestion and treatment with monoclonal and polyclonal antiplacental antibodies. Intestinal ALP was detected in 16 infants with bowel necrosis--13 had fetal intestinal ALP (FI-ALP) and three had adult intestinal ALP (AI-ALP). FI-ALP was detected in nine of the controls. In the babies with bowel necrosis intestinal ALP was found over all gestations, but in the controls only in those less than 34 weeks. The percentages of total ALP activity due to intestinal ALP were significantly higher in those with bowel necrosis compared with matched controls (p = 0.028). In babies of all gestations diagnostic sensitivity for the presence of intestinal ALP as a marker of bowel necrosis was 73% and diagnostic specificity 59%. In babies greater than 34 weeks' gestation, diagnostic sensitivity fell to 60% but the test became completely specific. In two babies FI-ALP increased from zero/trace to high activity coincident with the episode of bowel necrosis. In 16 babies with signs of necrotising enterocolitis but unconfirmed bowel necrosis FI-ALP was detected in four. Intestinal ALP seems to be released into the circulation in some babies with bowel necrosis, but its detection does not have the diagnostic sensitivity and specificity to be a reliable biochemical marker of the condition.

Cerebral Blood Flow Deficits in Hereditary Essential Myoclonus

Hereditary essential myoclonus is a disease in which segmental myoclonus is the sole clinical abnormality and whose cause is unknown. It is characterized by an early onset, a benign course, an autosomal dominant pattern of inheritance, the absence of any other neurologic dysfunction, and normal results of auxiliary tests. Cerebral blood flow studies of a father and son with this disease showed a cortical blood flow reduction contralateral to the myoclonus symptoms. We postulate the cause to be a focal unilateral subcortical cerebral lesion, either in the basal ganglia or in the brain stem, with subsequent cortical deafferentation.

Visual and Neural Function in Leberʼs Optic Neuropathy

This report details the chronology of vision loss for an 18-year-old Caucasian male with Leber's optic neuropathy. Findings of an oculo-visual assessment with auxiliary in-office tests of visual neural function, results of neurophysiological testing, and rehabilitative therapy with low vision aids are presented. The clinical characteristics of this devastating disorder are reviewed.

Centralization and Elite Circulation in a Soviet Republic

Central control over personnel placement in the Soviet Union (the nomenklatura system) is widely regarded as the complement to the centralization of substantive policy making and implementation. Some recent studies, however, argue that the central authorities have used their appointments powers to ratify rather than alter the results of the circulation process specific to localities. In order to advance the terms of this discussion, (he present study employs a systemic model of circulation. Here, circulation is regarded as a Markov process involving the movement of vacancies across a stratified hierarchy of 2,034 positions in the Belorussian Republic, and allunion jobs occupied by Belorussian politicans, over the period 1966–86. The model's predictions are reasonably accurate for the full data set but fit the data especially well when all-union positions are excluded, indicating a marginal centralizing influence on elite circulation that results more from the interaction between national and republic personnel systems than from centrally co-ordinated cadres policies in either Moscow or Minsk. Three auxiliary tests also support the conclusions derived from the Markov analysis.

Measurements of hCG and PAPP-A in uncommon types of ectopic gestation

Seven out of 54 women with ectopic gestation had uncommon features such as extra-tubal implantation or multiple intratubal pregnancy. Depressed levels (< 10th centile) or apparent absence of circulating human chorionic gonadotrophin (hCG) and pregnancy-associated plasma protein A (PAPP-A) were seen respectively in 5 and 7 of 7 women studied. Normal levels of hCG were seen in two women, one with an abdominal and one with an angular pregnancy. These data suggest that the synthesis of placental proteins in ectopic pregnancies is independent of the site of implantation and the number of embryos. Measurements of maternal levels of the 2 placental proteins seem to be applicable as auxiliary diagnostic tests for ectopic pregnancy, regardless of the site of implantation.

57Co-Bleomycin Scintigraphy in Staging of Carcinoma of the Cervix

65 patients with cervical cancer at various stages of the disease were studied scintigraphically after 57Co-bleomycin administration, active urine being flushed out from the bladder continuously. The patients were submitted to other auxiliary tests and the interpretation of scintigraphic images could thus be verified. Scintigraphic data were classified semiquantitatively by scoring in the range from zero to 5. Results were evaluated in terms of ROC-curves. This method of analysis permitted selection of cut-off levels for binary decisions that yielded satisfactory sensitivity and acceptable specificity of the test.

Spectrum Estimation Techniques for Characterization and Development of WT4 Waveguide-I

Techniques for reliably estimating the power spectral density function for both small and large samples of a stationary stochastic process are described. These techniques have been particularly successful in cases where the range of the spectrum is large. The methods are resistant to a moderate amount of contaminated or erroneous data and are well suited for use with auxiliary tests for stationarity and normality. Part I is concerned with background and theoretical considerations while examples from the development and analysis of the WT4 waveguide medium will be discussed in Part II, next issue.

Experimental tests of constitutive relations for polymers undergoing uniaxial shear flows

Stress development at the onset of steady shear flow and stress relaxation from steady state were measured in a stiffened Weissenberg Rheogoniometer over wide ranges of shear rate for three polystyrene solutions. Time dependent shear stressσ and first normal stress differenceN 1 were obtained from the torque and axial thrust. From extensive auxiliary tests we believe these data to be free of spurious effects associated with instrument compliance. The solutions have zero shear viscosities of 890, 3900 and 67 000 poise. Tests for consistency with strain rate constitutive models were made using thevan Es-Christensen relation and with relative strain models using theKearsley-Zapas relations. Substantial deviations were found in both cases. TheMarrucci model was also examined. As in theCarreau model B, the predicted start-up curves from theMarrucci model are in general qualitative accord with observations, but some systematic quantitative discrepancies remain.