Diagnostic Formula Research Articles

Circulation rate of change: A vortex approach for understanding accelerated inhomogeneous flows through intermediate times

We present a new simple diagnostic formula, Eq. (4) in this paper, involving a pressure difference, for determining the rate-of-change of total circulation, Γ̇D (within a domain D) for accelerated inhomogeneous flows, e.g., as may occur in Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) environments. We examine the RM, two-dimensional, shock-accelerated (Mach number M=1.3), single-mode, inviscid environment with an initially finite-width interfacial transition layer (ITL), and various postshock Atwood numbers, 0.2≤A*≤0.75. We show that for intermediate times (up to t∕tM<8.0), Γ̇D∕(Γshock∕tM), has several consistent behaviors and scaling laws depending on A*. Here Γshock, is the circulation deposited by the initial shock on the region of finite density gradient and tM is the time at which the single mode interfacial midcontour becomes multivalued.

Diagnosing clinical subsets of autoimmune liver diseases based on a multivariable model

Diagnosing autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis, and other autoimmune liver diseases remains an imperfect process. We need a more accurate, evidence-based diagnostic system. We conducted a national survey and identified 988 cases of liver disease which did not satisfy the inclusion criteria for any liver disease of known etiology. We expected these cases to include autoimmune liver disease (AILD) and its variant forms. We selected 269 prototype cases for which histological re-evaluation of liver biopsy by independent expert hepatopathologists and the original diagnosis coincided. We did a multiple logistic regression analysis to determine explanatory variables that would distinguish cases of AIH and PBC from those of non-AIH and non-PBC, respectively. We constructed a multivariable diagnostic formula that gave AIH and PBC disease probabilities and validated it in a study of an additional 371 cases (validation group). Based on the results of the statistical analysis, we selected three laboratory tests and four histological features as independent variables correlated to the diagnosis of both AIH and PBC. For the validation group, assuming that the original diagnosis was correct, the sensitivity and specificity for AIH were 86.3% and 92.4%, respectively. For PBC the sensitivity and specificity were 82.5% and 63.7%, respectively. A detailed analysis of inconsistent cases showed that the diagnosis based on the formula had given the correct diagnosis, for either AIH or PBC, except for 5 cases (1.3%) in which disease probability was low for both. A seven-variable formula based on three laboratory tests and four histological features gives significant information for the diagnosis of AILD.

Cloud Parameterizations in SUNYA Regional Climate Model for the East Asia Summer Monsoon Simulations

East Asia summer monsoon (EASM) simulations are conducted to evaluate three schemes which determine cloud properties used in the radiation calculation of the State University of New York at Albany (SUNYA) regional climate model (RCM). Scheme-Ⅰ uses diagnostic cloud cover and cloud water while Scheme-Ⅱ uses prognostic cloud water along with overcast sky; both schemes are commonly employed in RCMs. In Scheme-Ⅲ, cloud cover is determined by diagnostic formula, but the cloud water is calculated by the weighted means of its diagnosed and prognosed values. Therefore, Scheme-Ⅲ considers the subgrid-scale clouds as Scheme-Ⅰ and maintains consistent cloud properties in radiation calculation and microphysical processes as Scheme-Ⅱ. Cloud radiative forcing (CRF) which provides a quantification of the cloud-radiation-climate interaction is adopted to compare the three schemes in simulating the 1991 EASM, characterized by large amounts of cloud and persistent rainfall over Yangtze-Huai River valley. With these three cloud schemes, the SUNYA RCM is capable of simulating the intra-seasonal variations of observed cloud cover and longwave CRF. The transition of shortwave CRF is not properly simulated due to the constantly presented low-level clouds. Mostly the magnitude of CRF is overestimated by 13-22 W m^(-2) for shortwave CRF and by 12-16 W m^(-2) for longwave CRF. It is also found that the surface temperature biases are highly correlated (with correlation coefficient greater than 0.8) to the shortwave CRF biases. Therefore, Scheme-Ⅲ resulting in less low-level cloud water and the least shortwave CRF biases simulates surface temperatures in better agreement with observations. Analyses of surface energy balance components indicate that the CRF changes dominate the surface temperature responses and the consequent surface latent heat and sensible heat flux feedbacks significantly offset them. Finally, comparisons of the diurnal variations of simulated cloud water among the three schemes show that Scheme-Ⅲ provides consistency between cloud microphysics and radiation.

Sensitivity analysis of constrained linear L1 regression: perturbations to response and predictor variables

The active set framework of the reduced gradient algorithm is used to develop a direct sensitivity analysis of linear L 1 (least absolute deviations) regression with linear equality and inequality constraints on the parameters. We investigate the effect on the L 1 regression estimate of a perturbation to the values of the response or predictor variables. For observations with nonzero residuals, we find intervals for the values of the variables for which the estimate is unchanged. For observations with zero residuals, we find the change in the estimate due to a small perturbation to the variable value. The results provide practical diagnostic formulae. They quantify some robustness properties of constrained L 1 regression and show that it is stable, but not uniformly stable. The level of sensitivity to perturbations depends on the degree of collinearity in the model and, for predictor variables, also on how close the estimate is to being nonunique. The results are illustrated with numerical simulations on examples including curve fitting and derivative estimation using trigonometric series.

Physically based two‐moment bulkwater parametrization for warm‐cloud microphysics

AbstractA two‐moment bulkwater parametrization scheme for warm‐cloud microphysics is developed via statistical analyses of results from a detailed parcel model. This computationally efficient scheme is quite accurate and produces bulkwater properties which resemble the results from a fully explicit microphysical model. It responds sensitively to the effect of aerosol types on the cloud drop number concentration and the timing of rain initiation. Diagnostic formulae are also provided for the group fall velocity, number and mass sedimentation fluxes, the radar reflectivity factor, and the effective radii of cloud drops and raindrops. This physically sound and easy to use parametrization scheme could be useful in improving the microphysical representation in regional‐ and cloud‐scale models. Copyright © 2004 Royal Meteorological Society

Identifying patients at risk of early postoperative recurrence of lung cancer: a new use of the old CEA test

Background In the current study, we report the carcinoembryonic antigen (CEA) capability to predict early tumor relapses after a pulmonary resection for nonsmall cell lung cancer (NSCLC). Methods We studied 118 consecutive NSCLC patients who were clinically judged operable and were eventually operated upon. Anthropometric, clinical, and CEA data along with the results of both preoperative and postoperative stage classifications were recorded. All patients were followed up for at least 1 year after surgery and the time to the first clinical recurrence recorded. Receiver-operating characteristic (ROC) curves and diagnostic formulas were used for data analysis. Results In this series the CEA test was among the most accurate methods to predict an early postoperative recurrence (ROC area: 0.72, 95% confidence interval [CI]: 0.60 to 0.85, p = 0.001; accuracy rate for CEA at the threshold of 10 ng/mL: 83%, CI: 76% to 90%). Also predictive was the postoperative pathologic stage of disease (ROC area: 0.68, CI: 0.56 to 0.80, p = 0.007). In tumors pathologically classified in stage Ia to IIb, a preoperative CEA level higher than 10 ng/mL was associated with a 67% probability of tumor relapse. In the same stages of disease, a CEA level less than 10 ng/mL increased the baseline probability of no recurrence from 80% to 88%. Conclusions In operable patients with NSCLC the frequency of abnormal serum concentrations of CEA is low (17% in our series). However, it is important to identify such a small group of high-risk patients as many of them (in our study, 55% and 70% of those with a CEA value in excess of, respectively, 5 and 10 ng/mL) will develop an early postoperative recurrence. Such patients should be investigated preoperatively by mediastinoscopy or positron emission tomography in even in the absence of suspicious symptoms and signs. Then after an apparently successful operation, they should be carefully followed up. These patients could represent a suitable target for neoadjuvant clinical trials of selected high-risk groups.

The Hanle Effect of the Two‐Level Atom in the Weak‐Field Approximation

We apply the weak-field approximation of the line profiles, ωB Δω (ωB being the Larmor frequency and Δω the width of the line profile), adopting a second-order Taylor expansion in the Larmor frequency, to the polarized emission coefficients of the resonance transition in a two-level atom with values of the total angular momentum Ju and Jl, for the upper and lower levels, respectively. Using methods of Racah's algebra, we then derive rather compact algebraic expressions for the Stokes parameters of the radiation scattered locally in this transition. The advantage of using a second-order Taylor expansion of the emission coefficients is that the contributions of the Hanle effect and the Zeeman effect to the Stokes vector of the scattered radiation are easily identified and their respective roles in determining the polarization properties of the line better understood. Under the further assumption of unpolarized lower level, these expressions can be applied to derive explicit diagnostic formulae for polarized, resonance-scattering radiation, in terms of the relative geometry of the observer with respect to the solar magnetic field at the scattering center. The typical case of a spinless, two-level atom with Ju = 1 and Jl = 0 is explicitly worked out, and the corresponding diagnostic formulae are used to clarify some interesting properties of the Hanle effect. Finally, we compare these results, derived from the quantum-mechanical theory of line formation, with a recently proposed, classical formulation of the Hanle effect.

Value of sonomorphological criteria of the endometrium in women with postmenopausal bleeding: a multivariate analysis

This study was performed to examine whether an improvement in the transvaginal sonographic evaluation of the endometrium is possible by the addition of sonomorphological criteria to the measurement of endometrial thickness in women with postmenopausal bleeding. Various sonomorphological criteria were analyzed prospectively in 321 patients with postmenopausal bleeding. In a logistic regression model relevant criteria were selected and a diagnostic formula for differentiation of endometrial sonographic findings was derived. The criteria of endometrial structure, endometrial-myometrial border and endometrial thickness were significant for the differentiation of malignancy. These results allowed an estimation of the probability of malignancy for each sonographic endometrial finding. Using the cut-off point of 0.1 for the probability of malignancy, the sensitivity and specificity were 96.8% and 61.9%, respectively, with an accuracy of 72.3%. In contrast, the differentiation by endometrial thickness as the sole criterion (cut-off point > or = 5 mm) achieved a sensitivity of 97.9% and a specificity of 33.2%, with an accuracy of 52.3%. A useful diagnostic formula based on sonomorphological and metric criteria for endometrial differentiation was obtained. The specificity and accuracy increased with a minimal loss of sensitivity. However, estimates for sensitivity, specificity, and accuracy may be overoptimistic because they were derived from the same data used for development of the model.

Serum biomarkers facilitate the recognition of early- stage cancer and may guide the selection of surgical candidates: A study of carcinoembryonic antigen and tissue polypeptide antigen in patients with operable non–small cell lung cancer

Objectives: Copious literature shows that in lung cancer many serum markers, especially the cytokeratin degradation products, correlate with the extent of disease. In 1995, we suggested the possibility of predicting the resectability of non–small cell lung cancer by measuring the plasma level of the tissue polypeptide antigen, a marker of the cytokeratin family. This study was designed (1) to confirm the earlier data in a new prospective evaluation, (2) to comparatively assess another classic biomarker (ie, the carcinoembryonic antigen), and (3) to incorporate their results into the preoperative evaluation of non–small cell lung cancer. Methods: We analyzed the database of a single institution over a 5-year period (1994-1998) in a community-based hospital and second referral level institution for a province of 500,000 people. The database included 124 consecutive patients (105 men) with pathologically documented lung cancer (50% with adenocarcinoma) accurately staged, clinically judged operable or potentially operable, and eventually operated on. Anthropometric, clinical, and laboratory data (including the carcinoembryonic antigen and tissue polypeptide antigen serum levels) and the results of a complex staging workup were prospectively recorded. Receiver-operating characteristic curves and diagnostic formulas were used for data analysis. Results: Computed tomography of the thorax, upper part of the abdomen, and brain was the most accurate preoperative method to assess tumor resectability (receiver-operating characteristic area: 0.76, 95% confidence intervals: 0.67-0.86, P =.000; accuracy rate: 77%, confidence intervals: 69%-84%). Tissue polypeptide antigen was also predictive for tumor resectability (receiver-operating characteristic area: 0.62, 95% confidence intervals: 0.51-0.73, P =.035; accuracy rate at a threshold level of 110 U/L: 65%, 95% confidence intervals: 56%-73%). Carcinoembryonic antigen was diagnostic only at the extreme values of its distribution (accuracy rate at a level up to 10 ng/mL: 69%, 95% confidence intervals: 60%-77%). The probability of finding resectable disease at the time of the operation increased from 78% (baseline computed tomography–based probability) to 83% when the concentration of tissue polypeptide antigen was lower than 90 U/L and to 85% when the concentration of carcinoembryonic antigen was below 10 ng/mL. The probability of discovering an advanced disease increased from 68% (baseline computed tomography–based probability) to 89% when tissue polypeptide antigen levels were abnormal and to 100% when carcinoembryonic antigen concentrations were higher than 10 ng/mL. Conversely, the predictability of computed tomography was diminished by contrasting biomarker results, requiring further clinical investigations. Conclusions: Computed tomography remains the gold standard for the preoperative evaluation of non–small cell lung cancer, although it may significantly underestimate the real tumor extension. The addition of the easy and inexpensive tissue polypeptide antigen test (with or without carcinoembryonic antigen) is capable of correcting this underestimation and helps to decide whether to completely rely on computed tomography or order additional clinical investigations.J Thorac Cardiovasc Surg 2001;122:891-9

Diagnostics of Magnetic Field Strength in Gyrosynchrotron Radiation Regions for the Case of Transverse Propagation

A set of diagnostic formulas is, for the first time, proposed to deal with the magnetic field strength B in gyrosynchrotron radiation regions for the transverse propagation case. The diagnostic formulas of B are applied to analyze a solar limb event. The differences of diagnostic results of B are compared for the different propagation cases and it is found that the differences are rather large. So in the analysis of limb burst we should use the diagnostic formulas for the transverse propagation.

Diagnostics of magnetic field strength for gyrosynchrotron radiation regions of the lower harmonics

A diagnostic formula of magnetic field strength of gyrosynchrotron radiation regions of the tower harmonics (5 less than or equal to S less than or equal to 10) is presented based on their emissivity eta(nu)/BN, absorptivity kappa(nu)B/N, and the turnover frequency of radio spectra nu(P). Their diagnostic error is estimated. And an accurate relation between electron energy spectral index delta and brightness temperature spectral index beta is also given.

Hei10830 A Line Polarimetry: A New Tool to Probe the Filament Magnetic Fields

In this paper, we present a new Stokes polarization observation of a solar filament using the neutral helium line at 10830 A. Similar to the prominence Hanle effect, the polarization of the filament is due to the resonant scattering and magnetic depolarization of the photospheric radiation; it differs only in the scattering geometry. Since this represents one of the first filament polarization observations, we also present a classical derivation of a set of diagnostic formulae that relate the filament polarization signals to the vector magnetic field. We measured the full Stokes profiles (I, Q, U, V) by scanning the slit of the spectrograph parallel to the axis of a small filament. In one section of the filament, the polarization signals showed that the axial component of the magnetic field reverses direction on either side of the filament axis. This axial field reversal is not predicted by any of the existing magnetic field models of the filament, nor was it observed by previous prominence Hanle effect observations. We propose that a tilted magnetic field loop across the filament axis can explain the observed axial field reversal. This observation also serves to demonstrate that measurements of the polarization of the He I 10830 A radiation from filaments is a useful new tool for the diagnostics of filament magnetic field structures.

Diagnostic formula for the differentiation of adnexal tumors by transvaginal sonography: Prompeler HJ.; Madjar H.; Sauerbrei W.; Lattermann U.; Pfleiderer A. DEU Obstet Gynecol 1997 89/3 (428–433)

International Journal of Gynecology & ObstetricsVolume 57, Issue 3 p. 346-346 Citations from the literature (including the russian literature) oncology Diagnostic formula for the differentiation of adnexal tumors by transvaginal sonography Prompeler HJ.; Madjar H.; Sauerbrei W.; Lattermann U.; Pfleiderer A. DEU Obstet Gynecol 1997 89/3 (428–433) First published: 15 December 1997 https://doi.org/10.1016/S0020-7292(97)89954-7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume57, Issue3June 1997Pages 346-346 RelatedInformation

Diagnostic formula for the differentiation of adnexal tumors by transvaginal sonography

To create a strategy for sonographic differentiation of benign and malignant adnexal tumors in premenopausal and postmenopausal patients. Multiple sonomorphologic criteria were analyzed prospectively in 754 tumors. Four hundred were found in premenopausal and 354 in postmenopausal women. In a logistic regression model, relevant criteria were selected, and a diagnostic formula for tumor differentiation was derived. There were 165 malignant tumors, of which 37 (9.2%) were found in premenopausal and 128 (36.2%) in postmenopausal women. In both groups, the criteria of solid phase and ascites were the most significant. Further important diagnostic criteria were structure and tumor size in premenopausal women and cyst architecture and tumor surface in postmenopausal women. These results allowed an estimation of the probability of malignancy. Using a cutoff point of 10% for the probability to classify tumors as malignant, the sensitivity and specificity in premenopausal patients were 86.5% and 92.6%, respectively, with an accuracy of 92%. In postmenopausal women, the sensitivity, specificity, and accuracy were 93%, 82.7%, and 86.6%, respectively. Assuming a prevalence as given in the study, the positive and negative predictive values were 54.4% and 98.5% in premenopausal and 75.3% and 95.4% in postmenopausal women. With four binary criteria, a useful diagnostic formula for tumor differentiation was obtained. However, estimates for sensitivity, specificity, and accuracy may be too optimistic because they were derived from the same data that were already used for model selection.

Diagnostic Formula for the Differentiation of Adnexal Tumors by Transvaginal Sonography

In Brief Objective To create a strategy for sonographic differentiation of benign and malignant adnexal tumors in premenopausal and postmenopausal patients. Methods Multiple sonomorphologic criteria were analyzed prospectively in 754 tumors. Four hundred were found in premenopausal and 354 in postmenopausal women. In a logistic regression model, relevant criteria were selected, and a diagnostic formula for tumor differentiation was derived. Results There were 165 malignant tumors, of which 37 (9.2%) were found in premenopausal and 128 (36.2%) in postmenopausal women. In both groups, the criteria of solid phase and ascites were the most significant. Further important diagnostic criteria were structure and tumor size in premenopausal women and cyst architecture and tumor surface in postmenopausal women. These results allowed an estimation of the probability of malignancy. Using a cutoff point of 10% for the probability to classify tumors as malignant, the sensitivity and specificity in premenopausal patients were 86.5% and 92.6%, respectively, with an accuracy of 92%. In postmenopausal women, the sensitivity, specificity, and accuracy were 93%, 82.7%, and 86.6%, respectively. Assuming a prevalence as given in the study, the positive and negative predictive values were 54.4% and 98.5% in premenopausal and 75.3% and 95.4% in postmenopausal women. Conclusions With four binary criteria, a useful diagnostic formula for tumor differentiation was obtained. However, estimates for sensitivity, specificity, and accuracy may be too optimistic because they were derived from the same data that were already used for model selection. A useful diagnostic formula for sonographic tumor differentiation is obtained in premenopausal and postmenopausal women and provides an accurate differentiation between benign and malignant adnexal tumors.

Measurement of irregular astigmatism using semimeridian data from videokeratographs.

Irregular astigmatism is one of the most troublesome side effects of corneal surgery. We attempted to quantify irregular astigmatism in a simple way, using semimeridian data from videokeratographs of corneas with different amounts of irregular astigmatism. We studied the corneal topography of 30 normal corneas to be used as controls, 30 corneas from patients after radial keratotomy, 30 corneas from patients after nonfreeze myopic keratomileusis, and 30 corneas with clinically apparent keratoconus. We developed two diagnostic formulas, a refractive power symmetry index and an angle symmetry index, using the absolute-scale, color-coded map, and semimeridian data from the EyeSys Corneal Analysis System, and used them to compare the four groups of corneas. In the corneas with irregular astigmatism, values for the refractive power symmetry index and angle symmetry index were significantly higher than in the normal corneas. The refractive power symmetry index confidence interval set at 95% was 0.58 diopters (D) (range 0.00 D to 0.58 D) in the control group. Using these limits, most values in the radial keratotomy, keratomileusis, and keratoconus groups were abnormal. Spectacle-corrected visual acuity correlated negatively with the refractive power symmetry index (rs = -0.58, p < .001). The refractive power symmetry index sensitivity and specificity were respectively 97% and 66%. Spectacle-corrected visual acuity did not correlate with the angle symmetry index. Semimeridian data from videokeratographs can be used to quantify irregular astigmatism.

A study of the kinetics of topochemical reactions by scanning electron microscopy

AbstractBased on the data of fluorapatite interaction with tartaric and sulfuric acids, a scheme is developed for establishing the function of states distribution for product particles by means of scanning electron microscopy (SEM). The result of the studies confirms the availability of a quantitative description of topochemical reactions kinetics using SEM data in the terms presented by diagnostic formulae.

Wind profiles in the stable boundary layer, and the effect of low relief

AbstractWind profiles through the stable boundary layer are presented. The data were collected at a site located in a shallow river valley and show evidence of upstream effects near the edge of the valley. The wind‐speed profiles are consistent with a non‐dimensional shear Øm = 1 + 3z/L for z/L &lt; 0.5. Changes in wind speed and direction are found to occur over a greater depth than the depth of the turbulent nocturnal boundary layer estimated from various diagnostic formulae.

A Framework for Comparative Study of Minority-Group Aspirations

Abstract Most states have one or more ethnic minorities. Members of such groups invariably experience some degree of dissatisfaction with their status. In consequence, tension between subnational identity and national affiliation is a persistent and pervasive reality. Although a large literature addresses the relationship between culture and nationality, it cannot be said that the interaction of minority-group aspirations and related government policies is well understood. In this article, we seek to build a foundation for such understanding through the development of a framework for comparative study. We propose a diagnostic formula that focuses on minority-group demands ranging from recognition, access, and participation to separation, autonomy, and independence. We then consider the significance of geographical context and group-state interaction for minority goals. A more detailed analysis of circumstances that foster accommodation or conflict appears in nine case studies: Tamils in Sri Lanka, Druze i...

Diagnostics of heterogeneous chemical reactions by cathodoluminescence

AbstractA scheme is developed for establishing the mechanism of heterogeneous chemical reactions by scanning electron microscopy (SEM) using cathodoluminescent markers (or flares CLF). Diagnostic formulas are found for the distribution function of product crystals with respect to their states under different reaction conditions. The diagnostic scheme is checked for the reaction of F‐apatite with phosphoric acid.