scholarly journals Co-tame polynomial automorphisms

2019 ◽  
Vol 29 (05) ◽  
pp. 803-825 ◽  
Author(s):  
Eric Edo ◽  
Drew Lewis
Keyword(s):  
Characteristic Zero ◽  
Independent Interest ◽  
Technical Tool ◽  
Polynomial Automorphism ◽  
Polynomial Automorphisms ◽  
Negative Results ◽  
Dimension Formula ◽  
Positive Results ◽  
Main Technical Tool

A polynomial automorphism of [Formula: see text] over a field of characteristic zero is called co-tame if, together with the affine subgroup, it generates the entire tame subgroup. We prove some new classes of automorphisms of [Formula: see text], including nonaffine [Formula: see text]-triangular automorphisms, are co-tame. Of particular interest, if [Formula: see text], we show that the statement “Every [Formula: see text]-triangular automorphism is either affine or co-tame” is true if and only if [Formula: see text]; this improves upon positive results of Bodnarchuk (for [Formula: see text], in any dimension [Formula: see text]) and negative results of the authors (for [Formula: see text], [Formula: see text]). The main technical tool we introduce is a class of maps we term translation degenerate automorphisms; we show that all of these are either affine or co-tame, a result that may be of independent interest in the further study of co-tame automorphisms.

scholarly journals Effective Density for Inhomogeneous Quadratic Forms I: Generic Forms and Fixed Shifts

2020 ◽  
Author(s):  
Anish Ghosh ◽  
Dubi Kelmer ◽  
Shucheng Yu
Keyword(s):  
Quadratic Forms ◽  
Effective Density ◽  
Independent Interest ◽  
Diophantine Condition ◽  
Technical Tool ◽  
Optimal Density ◽  
Density Result ◽  
Similar Density ◽  
Main Technical Tool

Abstract We establish effective versions of Oppenheim’s conjecture for generic inhomogeneous quadratic forms. We prove such results for fixed shift vectors and generic quadratic forms. When the shift is rational we prove a counting result, which implies the optimal density for values of generic inhomogeneous forms. We also obtain a similar density result for fixed irrational shifts satisfying an explicit Diophantine condition. The main technical tool is a formula for the 2nd moment of Siegel transforms on certain congruence quotients of $SL_n(\mathbb{R}),$ which we believe to be of independent interest. In a sequel, we use different techniques to treat the companion problem concerning generic shifts and fixed quadratic forms.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

PET/CT WITH 68GA-PSMA-11 IN DETECTION OF PRIMARY TUMOR AND RECURRENCE OF PROSTATE CANCER

2018 ◽  
Vol 64 (6) ◽  
pp. 799-804
Author(s):  
Darya Ryzhkova ◽  
M. Poyda
Keyword(s):  
Prostate Cancer ◽  
Primary Tumor ◽  
Biochemical Recurrence ◽  
Whole Body ◽  
Negative Results ◽  
Primary Prostate Cancer ◽  
Pet Ct ◽  
The Relationship ◽  
Positive Results ◽  
T Category

Purpose: To study the diagnostic value of PET-CT with 68Ga-PSMA-11 in the diagnosis of a primary prostate cancer, preoperative staging, and the detection of recurrence of prostate cancer (PCa). Methods: 28 patients aged 64.7 ± 8.74 years were included. 10 patients primary prostate cancer, and 18 patients with biochemical recurrence of the disease after radical treatment were examined. All patients underwent PET-CT with 68Ga-PSMA-11 according the whole body protocol. Interpretation of images was performed visually and quantitatively by calculation of SUL max. Results: High focal or diffuse 68Ga-PSMA-11 uptake was found in prostate parenchyma in patients with primary prostate cancer. Additionally metastases in regional lymph nodes were diagnosed in 4 patients and bone metastases were found in one patient. The correlation between 68Ga-PSMA-11 uptake level and Gleason index in the primary tumor (R Spearmen = 0.25, p = 0.57) was not observed. PET-positive results were obtained in 14 patients and PET-negative results in 4 patients with biochemical recurrence of PCa. The relationship between the frequency of PET-positive results and Gleason index was not revealed (R Spearmen = 0.2, p = 0.39). We found a weak but significant correlation between the frequency of PET-positive results and the prostate tumor stage according to the T category (R Spearmen = 0.49, p = 0.049). In patients with low values of PSA (less than 1.0 ng/ml) in 4 out of 9 cases, PET-negative results were obtained. In patients with PSA level more than 1.0 ng/ml PET-positive results were obtained in all cases. Conclusions: PET/CT with 68Ga-PSMA-11 allows to diagnose the primary prostate cancer, to establish the stage of the disease in categories N and M, and also to determine the localization and dissemination of the tumor in patients with biochemical recurrence of prostate cancer. The relationship between 68Ga-PSMA-11 uptake in primary tumor and Gleason index was not found. The probability of obtaining PET-positive results in cases of biochemical recurrence is affected by a PSA level above 1 ng/ml and a high stage of the disease according to the T category (T3-T4).

scholarly journals Diagnostic Performance of Ankle-Brachial Pressure Index in Lower Extremity Arterial Disease

2021 ◽  
Vol 07 (03) ◽  
pp. e132-e137
Author(s):  
Mohammed Alagha ◽  
Thomas M. Aherne ◽  
Ahmed Hassanin ◽  
Adeel S. Zafar ◽  
Doireann P. Joyce ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Sensitivity And Specificity ◽  
False Negative ◽  
Arterial Disease ◽  
Initial Assessment ◽  
Reference Standard ◽  
Lower Extremity Arterial Disease ◽  
Negative Results ◽  
Positive Results ◽  
Arterial Imaging

Abstract Introduction Ankle-brachial pressure indices (ABIs) continue to form the basis of diagnostics for lower extremity arterial disease (LEAD). However, there remains a paucity of data to support its accuracy. This study aims to evaluate its diagnostic sensitivity and specificity using established arterial-imaging modalities as a benchmark. Methods In this retrospective study, a regional, prospectively maintained, vascular laboratory database was interrogated to identify referred patients with arterial disease who underwent concomitant assessment with ABI and lower limb arterial duplex ultrasound (DUS). Duplex acted as the reference standard. Those who had peripheral computed tomography angiogram (CTA) within 3 months of initial assessment were included in a subgroup analysis to correlate ABI with CTA. The primary end point was the sensitivity and specificity of ABI compared with DUS as the reference standard. Results Concomitant assessment was performed in 438 limbs (250 patients) over a 27-month period. The ABI was normal (0.9 to 1.4) in 196 limbs (44.9%) and abnormal in the remaining 241 limbs (55.1%). False-positive results occurred in 83 out of 241 limbs (34.4%), and false-negative results occurred in 54 limbs out of 196 (27.5%). True-positive results were 158 out of 241 limbs (65.6%), whereas true-negative results were 142 out of 196 limbs (72.4%). ABI using DUS as a benchmark identified a sensitivity for peripheral artery disease of 72.3% and a specificity of 69.3%. Concomitant CTA imaging was available in 200 limbs. The sensitivity and specificity of ABI correlated with CTA were 65.5 and 68.8%, respectively. Conclusion ABIs have a moderate predictive value in the diagnosis of LEAD. Normal range outcomes cannot be taken to infer the absence of LEAD and, as such, further arterial imaging in the form of DUS or angiography should be strongly considered in those with suspected underlying disease requiring intervention. Further noninvasive tests such as exercise studies or pulse volume waveforms should be considered, if diagnostic uncertainty exists, in those requiring nonoperative intervention and risk factor control.

scholarly journals The Interpretation of Studies Using the Reading Level Design

1989 ◽  
Vol 21 (4) ◽  
pp. 413-424 ◽  
Author(s):  
Usha Goswami ◽  
Peter Bryant
Keyword(s):  
Reading Disability ◽  
Reading Level ◽  
Chronological Age ◽  
Control Group ◽  
Causal Factors ◽  
Negative Results ◽  
Level Design ◽  
Positive Results

Recent research in reading disability has been strengthened by the addition of a reading level (RL) control group to the more traditional chronological age (CA) control group. However, caution is required in interpreting results from these two kinds of control. Only positive results in a RL match and negative results in a CA match are interpretable; negative results in a CA match and positive results in a RL match are not. Furthermore, the RL control group cannot be used to unambiguously determine between specific deficit and developmental lag interpretations of reading disability. It is argued that the use of the RL control can only ever be a first step in research aimed at delineating the causal factors in reading backwardness.

scholarly journals Accuracy of brush cytology in biliopancreatic strictures: a single-center cohort study

2021 ◽  
Vol 49 (2) ◽  
pp. 030006052098777
Author(s):  
Song-Ming Ding ◽  
Ai-Li Lu ◽  
Bing-Qian Xu ◽  
Shao-Hua Shi ◽  
Muhammad Ibrahim Alhadi Edoo ◽  
...  
Keyword(s):  
Duct Cell ◽  
Carbohydrate Antigen ◽  
Maximum Diameter ◽  
Biliary Duct ◽  
Brush Cytology ◽  
Tumor Biopsy ◽  
Bile Duct Wall ◽  
Negative Results ◽  
Brushing Cytology ◽  
Positive Results

Objective False positive and negative results are associated with biliary tract cell brushing cytology during endoscopic retrograde cholangiopancreatography (ERCP). The causes are uncertain. The purpose of this study was to evaluate the accuracy of diagnoses made via cell brushing in our center, and to explore the factors influencing diagnosis. Methods The clinical data of patients who underwent cell brushing at our center from January 2016 to August 2019 were retrospectively analyzed. These included age, gender, stricture location, thickness of the bile duct wall in the narrow segment, maximum diameter of the biliary duct above the stricture, number of cell brush smears, carbohydrate antigen 19-9, and carcinoembryonic antigen. Positive brush cytology results were compared with results of surgical histology or tumor biopsy as well as with the patient’s clinical course. Results Of the 48 patients who underwent cell brushing cytology, 27 (56.3%) had positive results. The sensitivity and specificity of biliary duct cell brushing was 79.4%, and 85.7%, respectively. None of the above-mentioned factors were associated with positive cytology brushing results. Conclusions Cell brushing cytology remains a reliable method for diagnosis of pancreaticobiliary malignancies.

scholarly journals Square-integrable representations of non-unimodular groups

1976 ◽  
Vol 15 (1) ◽  
pp. 1-12 ◽  
Author(s):  
A.L. Carey
Keyword(s):  
Hilbert Space ◽  
Reproducing Kernel ◽  
Reproducing Kernel Hilbert Space ◽  
Hilbert Algebra ◽  
Technical Tool ◽  
Integrable Representation ◽  
Hilbert Algebras ◽  
Orthogonality Relations ◽  
Square Integrable Representation ◽  
Main Technical Tool

In the last three years a number of people have investigated the orthogonality relations for square integrable representations of non-unimodular groups, extending the known results for the unimodular case. The results are stated in the language of left (or generalized) Hilbert algebras. This paper is devoted to proving the orthogonality relations without recourse to left Hilbert algebra techniques. Our main technical tool is to realise the square integrable representation in question in a reproducing kernel Hilbert space.

scholarly journals The Positive Predictive Value of Diagnostic Ultrasound for Occult Herniae

2006 ◽  
Vol 88 (2) ◽  
pp. 165-167 ◽  
Author(s):  
M Bradley ◽  
J Morgan ◽  
B Pentlow ◽  
A Roe
Keyword(s):  
Positive Predictive Value ◽  
Predictive Value ◽  
Diagnostic Tests ◽  
Diagnostic Ultrasound ◽  
Pain Clinic ◽  
Diagnostic Problem ◽  
Clinical Criteria ◽  
Negative Results ◽  
Positive Results

INTRODUCTION The aim of this study is to ascertain the accuracy of diagnostic ultrasound in the assessment of the occult abdominal and groin herniae. The authors have previously demonstrated its efficacy in diagnosing the type of clinical groin herniae but occult herniae provide a further diagnostic problem. PATIENTS AND METHODS A total of 113 consecutive patients were referred prospectively for ultrasound examinations with clinically suspected occult herniae. All positive scans were offered surgery whilst the negative results were offered further imaging or other diagnostic tests depending on the clinical criteria. The end point for negative scans was based on 18-month follow-up or resolution of symptoms. RESULTS Overall, 59 scans showed positive results for herniae and 56 of these had surgery. In the other three patients, two refused an operation, and one had no hernia detected at operation. In the remaining 57 scans, ultrasound offered alternative soft tissue diagnoses in 23 patients and surgical/endoscopic diagnoses accounted for a further 8 patients. CONCLUSIONS Ultrasound offered a diagnosis for the symptomology in 82 patients (70.6%) of which 59 were herniae. The positive predictive value for hernia is 98.3%. Twenty-six patients with no diagnosis or confirmation of herniae on follow-up showed symptom resolution in 22 cases, and four patients were treated by the pain clinic.

scholarly journals Gambaran leukosit urin pada pasien tuberkulosis paru dewasa di RSUP Prof. Dr. R. D. Kandou Manado

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Pingkan C. Pasuhuk ◽  
Arthur E. Mongan ◽  
Mayer Wowor
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Pulmonary Tuberculosis ◽  
Dipstick Test ◽  
Chemical Test ◽  
Tuberculosis Patients ◽  
Negative Results ◽  
Normal Urine ◽  
Observational Descriptive Study ◽  
Positive Results ◽  
Urine Specimens

Abstract: Tuberculosis (TB) is an infectious diseases caused by Mycobacterium Tuberculosis. Consuming the anti-tuberculosis medicine such as streptomycin and rifampicin will cause nephrotoxic effect. In kidney disfunction especially the glomeruli, the number of leukocytes in the urine increase. The most common urinalysis tests are chemical test and microscopic test, especially the leukocyte urine test. These tests can be used to detect the kidney disfunction and the urinary tract infection. In normal urine, the result of the dipstick test is negative, and the result of microscopic test is 0-5/HPF. This study was aimed to obtain the description of leukocyte urinalysis in pulmonary tuberculosis patients at Prof. Dr. R. D. Kandou Hospital Manado. This was an observational descriptive study conducted in October-November 2016 at Prof. Dr. R. D. Kandou Hospital Manado. Samples were random urine specimens that met the predefined criteria. The results showed that based on the urinalysis, of 30 patients with pulmonary tuberculosis, 27 patients had negative results and 3 patients had positive results. Conclusion: There was no relationship between urine leucocyte and pulmonary tuberculosis in adult patients.Keywords: pulmonary tuberculosis, urinalysis, urine leukocyte Abstrak: Tuberkulosis (TB) merupakan penyakit infeksi yang disebabkan oleh Mycobacterium tuberculosis. Obat anti-tuberkulosis seperti streptomisn dan rifampisin memiliki efek nefrotoksik. Kerusakan ginjal terutama glomerulus dapat menimbulkan peningkatan leukosit dalam urin. Metode urinalisis yang sering digunakan yaitu uji kimia/ carik-celup dan mikroskopik. Pemeriksaan leukosit urin dapat digunakan untuk mengetahui adanya gangguan pada ginjal dan infeksi saluran kemih. Pada urin normal hasil pemeriksaan dipstick negatif dan hasil pemeriksaan mikroskopik urin 0-5 leukosit/LPB. Penelitian ini bertujuan untuk mendapatkan gambaran leukosit urin pasien tuberkulosis paru dewasa di RSUP Prof. Dr. R. D. Kandou Manado. Jenis penelitian ialah deskriptif observasional dan dilakukan pada bulan Oktober-November 2016 di RSUP Prof. Dr. R. D. Kandou Manado. Sampel penelitian ialah sampel urin sewaktu dari semua pasien tuberkulosis paru yang memenuhi kriteria yang telah ditentukan. Hasil urinalisis dari 30 pasien terdiagnosis penyakit tuberkulosis paru mendapatkan 27 pasien dengan hasil negatif dan 3 pasien dengan hasil positif. Simpulan: Tidak terdapat hubungan antara leukosit urin dengan tuberkulosis paru dewasa. Kata kunci: TB paru, urinalisis, leukosit urin

scholarly journals Ultrasonographicpotencial in detection of Acute Appendicitis

2009 ◽  
Vol 8 (4) ◽  
pp. 140-147
Author(s):  
V. N. Piskunov ◽  
V. D. Zavadovskaya ◽  
N. G. Zavyalova
Keyword(s):  
Acute Appendicitis ◽  
False Negative ◽  
Power Doppler ◽  
Vermiform Appendix ◽  
Vascular Pattern ◽  
True Negative ◽  
Horizontal Section ◽  
Negative Results ◽  
Interior Wall ◽  
Positive Results

On the grounds of ultrasonography of 275 patients with suspected Acute Appendicitis (AA) the diagnosis was confirmed in 63 (22,9%) cases, it was true-positive results; in 3 (1,1%) cases of non-confirmed AA ultrasound findings were regarded as false-positive results. True-negative results of examination were obtained in 194 cases (70,5%) and false-negative results — in 15 cases (5,5%). The presence of rarevascularity of interior wall and clear visualization of vessels in mesentery of vermiform appendix is typical for congestive appendicitis. When phlegmonous appendicitis there are numerous vascular branches in interior wall blood stream of appendix: they make a picture of color «crown» in horizontal section and color «stripe» in longitudinal section. Gangrenous appendicitis is attached to few color spots in those parts of appendix wall which are not destroyed yet. Vascular pattern in adjacent intestinal loops predominates over vascular pattern of vermiform appendix. In case of empyema vermiform appendix vascular pattern in the wall is detected only in mesentery area. Vascular pattern of appendix is not detected in cases of appendicular infiltrate and periappendicular abscess unlike vascular pattern of adjacent intestinal loops which is rather intensified. The sensitivity of ultrasonography in AA detection was 80,7%, specificity — 98,4%, and accuracy — 93,4%. High index of diagnostic effectiveness of the method was obtained because of adoption of combining B-mode with both Colour Doppler and Power Doppler methods.

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