Differential diagnostic utilities of combined testing for islet cell antibody, glutamic acid decarboxylase antibody, and tyrosine phosphatase antibody

Background. Beta-cell antibody tests are used for the differential diagnosis of diabetes mellitus. They permit to discriminate between the type 1 diabetes (T1D) and non-autoimmune diabetes types. To choose an appropriate test for ruling in or ruling out the T1D a physician needs to know how conclusive test results are. The most powerful estimate of test conclusiveness is its likelihood ratio (LHR). The higher LHR of a positive result (LHR+), the more posttest probability of T1D; the lower LHR of a negative result (LHR), the less posttest probability of T1D. Aims. To compare conclusiveness of single and combined tests for antibodies to islet cells (ICA), glutamate decarboxylase (GADA), and tyrosine phosphatase IA-2 (IA-2A), and to evaluate posttest probabilities of T1D at various pretest probabilities. Methods. All antibodies were tested in parallel in 169 children and adolescents with a new-onset T1D, and in 169 persons without this disease. ICA, GADA, and IA-2A were determined by indirect immunofluorescence, radioimmune assay, and ELISA, respectively. LHR+ and LHR were calculated with the MedCalc Statistical Software. Posttest T1D probabilities were calculated from Bayes theorem-based equation. Results. Among single tests, an ICA test had the greatest LHR+ and the smallest LHR, and consequently was the most reliable either for ruling in or ruling out the T1D. Among test combinations, an ICAGADA combination had the greatest LHR+ and was the most suitable for T1D confirmation. The triple combination ICAGADAIA-2A had the smallest LHR and was the most suitable for T1D exclusion. Conclusions. In the differential diagnosis of diabetes, the most appropriate test for ruling in the T1D is the double combination ICAGADA. With both antibodies positive, this combination provides the highest posttest T1D probabilities at any pretest probability. The most appropriate test for ruling out the T1D is the triple combination ICAGADAIA-2A. With all three antibodies negative, this combination provides the lowest posttest T1D probabilities

Test Results of the CLIC Damping Wiggler Prototype

The Compact Linear Collider (CLIC) will require ultralow emittance electron and positron beams. Such emittance will be achieved by radiative damping in the CLIC damping rings that will be realized by a use of high-field short-period superconducting damping wigglers. In the course of the CLIC technical feasibility studies, a full-scale damping wiggler prototype was fabricated in BINP. Main parameters of the wiggler are 51 mm of period, 3 T of magnetic field, 1.8 m of magnetic length, 18 mm of the pole gap, and indirect cooling by LHe. Four cryocoolers were used in the wiggler design, which allow its ordinary operation without LHe consumption. Above the magnetic requirements, the main design challenges for this prototype are scalability, particularly of the cooling concept, modularity, and the capability of sustaining a high radiative heat load. The wiggler powering tests and performance of the cryogenic system are described in this paper

Test Results of the CLIC Damping Wiggler Prototype

The Compact Linear Collider (CLIC) will require ultralow emittance electron and positron beams. Such emittance will be achieved by radiative damping in the CLIC damping rings that will be realized by a use of high-field short-period superconducting damping wigglers. In the course of the CLIC technical feasibility studies, a full-scale damping wiggler prototype was fabricated in BINP. Main parameters of the wiggler are 51 mm of period, 3 T of magnetic field, 1.8 m of magnetic length, 18 mm of the pole gap, and indirect cooling by LHe. Four cryocoolers were used in the wiggler design, which allow its ordinary operation without LHe consumption. Above the magnetic requirements, the main design challenges for this prototype are scalability, particularly of the cooling concept, modularity, and the capability of sustaining a high radiative heat load. The wiggler powering tests and performance of the cryogenic system are described in this paper