Structural Econometric Models in Forecasting Inflation at the National Bank of Poland

The paper presents the procedure and two structural macroeconometric models used at the National Bank of Poland for producing regular quarterly inflation projections. One of the models is a small macroeconomic model based on the New Keynesian Phillips curve, the IS curve and the exchange rate equation based on uncovered interest parity with risk factors. The other, more disaggregated model, explicitly focuses on the supply side and separates the steady state from short-term adjustments.macroeconomic models, inflation forecasting

Plasmonic concentrator of magnetic field of light

We propose an efficient concentrator of the magnetic component of evanescent field of light for measuring magnetic responses of nanostructures. It is in the form of a tapered fiber probe, which in its final part has corrugations along the angular dimension and is coated with metal except for the aperture at the tip. Internal, azimuthally polarized illumination is concentrated into a subwavelength spot with a strong longitudinal magnetic component H-z. Within the visual range of wavelengths 400-700 nm, the energy density of H-z is up to 50 times larger than that of the azimuthal electric E-phi one. This dominant H-z contribution may be used for magnetic excitation of elementary cells of metamaterials with a single probe guiding a wide spectrum of generated plasmons

Electric Field Standing Wave Effects in FT-IR Transflection Spectra of biological tissue sections: simulated models of experimental variability

The so-called electric field standing wave effect (EFSW) has recently been demonstrated to significantly distort FT-IR spectra acquired in a transflection mode, both experimentally and in simulated models, bringing into question the appropriateness of the technique for sample characterization, particularly in the field of spectroscopy of biological materials. The predicted effects are most notable in the regime where the sample thickness is comparable to the source wavelength. In this work, the model is extended to sample thicknesses more representative of biological tissue sections and to include typical experimental factors which are demonstrated to reduce the predicted effects. These include integration over the range of incidence angles, varying degrees of coherence of the source and inhomogeneities in sample thickness. The latter was found to have the strongest effect on the spectral distortions and, with inhomogeneities as low as 10% of the sample thickness, the predicted distortions due to the standing wave effect are almost completely averaged out. As the majority of samples for biospectroscopy are prepared by cutting a cross section of tissue resulting in a high degree of thickness variation, this finding suggests that the standing wave effect should be a minor distortion in FT-IR spectroscopy of tissues. The study has important implications not only in optimization of protocols for future studies, but notably for the validity of the extensive studies which have been performed to date on tissue samples in the transflection geometry

Detection of atrial fibrillation episodes in long-term heart rhythm signals using a support vector machine

Atrial fibrillation (AF) is a serious heart arrhythmia leading to a significant increase of the risk for occurrence of ischemic stroke. Clinically, the AF episode is recognized in an electrocardiogram. However, detection of asymptomatic AF, which requires a long-term monitoring, is more efficient when based on irregularity of beat-to-beat intervals estimated by the heart rate (HR) features. Automated classification of heartbeats into AF and non-AF by means of the Lagrangian Support Vector Machine has been proposed. The classifier input vector consisted of sixteen features, including four coefficients very sensitive to beat-to-beat heart changes, taken from the fetal heart rate analysis in perinatal medicine. Effectiveness of the proposed classifier has been verified on the MIT-BIH Atrial Fibrillation Database. Designing of the LSVM classifier using very large number of feature vectors requires extreme computational efforts. Therefore, an original approach has been proposed to determine a training set of the smallest possible size that still would guarantee a high quality of AF detection. It enables to obtain satisfactory results using only 1.39% of all heartbeats as the training data. Post-processing stage based on aggregation of classified heartbeats into AF episodes has been applied to provide more reliable information on patient risk. Results obtained during the testing phase showed the sensitivity of 98.94%, positive predictive value of 98.39%, and classification accuracy of 98.86%.Web of Science203art. no. 76

Fetal electrocardiograms, direct and abdominal with reference heartbeat annotations

Monitoring fetal heart rate (FHR) variability plays a fundamental role in fetal state assessment. Reliable FHR signal can be obtained from an invasive direct fetal electrocardiogram (FECG), but this is limited to labour. Alternative abdominal (indirect) FECG signals can be recorded during pregnancy and labour. Quality, however, is much lower and the maternal heart and uterine contractions provide sources of interference. Here, we present ten twenty-minute pregnancy signals and 12 five-minute labour signals. Abdominal FECG and reference direct FECG were recorded simultaneously during labour. Reference pregnancy signal data came from an automated detector and were corrected by clinical experts. The resulting dataset exhibits a large variety of interferences and clinically significant FHR patterns. We thus provide the scientific community with access to bioelectrical fetal heart activity signals that may enable the development of new methods for FECG signals analysis, and may ultimately advance the use and accuracy of abdominal electrocardiography methods.Web of Science71art. no. 20

Exploring Subcellular Responses of Prostate Cancer Cells to X-Ray Exposure by Raman Mapping

Understanding the response of cancer cells to ionising radiation is a crucial step in modern radiotherapy. Raman microspectroscopy, together with Partial Least Squares Regression (PLSR) analysis has been shown to be a powerful tool for monitoring biochemical changes of irradiated cells on the subcellular level. However, to date, the majority of Raman studies have been performed using a single spectrum per cell, giving a limited view of the total biochemical response of the cell. In the current study, Raman mapping of the whole cell area was undertaken to ensure a more comprehensive understanding of the changes induced by X-ray radiation. On the basis of the collected Raman spectral maps, PLSR models were constructed to elucidate the time-dependent evolution of chemical changes induced in cells by irradiation, and the performance of PLSR models based on whole cell averages as compared to those based on average Raman spectra of cytoplasm and nuclear region. On the other hand, prediction of X-ray doses for individual cellular component showed that cytoplasmic and nuclear regions should be analysed separately. Finally, the advantage of the mapping technique over single point measurements was verified by a comparison of the corresponding PLSR models

Cell viability assessment using the Alamar blue assay: A comparison of 2D and 3D cell culture models

Comparisons of 2D and 3D cell culture models in literature have indicated differences in cellular morphology and metabolism, commonly attributed the better representation of in vivo conditions of the latter cell culture environment. Thus, interest in the use of 3D collagen gels for in vitro analysis has been growing. Although comparative studies to date have indicated an enhanced resistance of cells on collagen matrices against different toxicants, in the present study it is demonstrated that non-adapted protocols can lead to misinterpretation of results obtained from classical colorometric dye-based cytotoxic assays. Using the well established Alamar Blue assay, the study demonstrates how the transfer from 2D substrates to 3D collagen matrices can affect the uptake of the resazurin itself, affecting the outcome of the assay. Using flow cytometry, it is demonstrated that the cell viability is unaffected when cells are grown on collagen matrices, thus the difference seen in the fluorescence is a result of a dilution of the resazurin dye in the collagen matrix, and an increased uptake rate due to the larger cell surface exposed to the surrounding environment, facilitating more effective diffusion through the cellular membrane. The results are supported by a rate equation based simulation, verifying that differing uptake kinetics can result in apparently different cell viability. Finally, this work highlights the feasibility to apply classical dye-based assays on collagen based 3D cell culture models. However, the diffusion and bioavailbility of test substances in 3D matrices used in in vitro toxicological assays must be considered and adaption of the protocols is necessary for direct comparison with the traditional 2D models. Moreover, the observations made based on the resazurin dye can be applied to drugs or nanoparticles which freely diffuse through the collagen matrices, thus affecting the effective concentration exposed to the cells

Does intraoperative application of TachoSil reduce the number of lymphoceles after pelvic lymphadenectomy?

Objectives: The degree of lymphoceles prevention was assessed using collagen patches coated with human coagulation factors (TachoSil, Nycomed International Management GmbH, Zurich, Switzerland). The study enrolled 50 consecutive patients with endometrial and cervical cancer stages IB to II who had undergone open hysterectomy and pelvic lymphadenectomy (PL). In addition, the drainage volumes of 22 patients with hypertension were compared to that of the rest of the study population. Furthermore, occurrence of lymphocele in patients with endometrial and cervical cancer were compared after completion of adjuvant treatment. Material and methods: Patients were simultaneously randomized in two groups: as a control (side without TachoSil applied) and study group (side with TachoSil applied). All surgical parameters were collected, and patients underwent ultrasound examination on postoperative days 1, 6, and 30, and at the end of treatment. Results: The TachoSil Group showed a lower drainage volume, 30 days after surgery, while outflow of fluid occurred in 11 (22%) of all TachoSil Group cases and 22 (44%) of all control group cases. Furthermore, two patients in the control group had symptomatic lymphocele, while the same number of cases was observed in the TachoSil Group. However, the TachoSil Group demonstrated a decreased tendency to lymphocele occurrence after the end of adjuvant therapy. Here, patients with the collagen patch developed lymphocele in 12% of all cases, as opposed to 18% without TachoSil. Conclusions: TachoSil is a useful support treatment option for reducing drainage volume and preventing lymphocele development after lymphadenectomy

Fabrication of corrugated Ge-doped silica fibers

We present a method of fabricating Ge-doped SiO2 fibers with corrugations around their full circumference for a desired length in the longitudinal direction. The procedure comprises three steps: hydrogenation of Ge-doped SiO2 fibers to increase photosensitivity, recording of Bragg gratings with ultraviolet light to achieve modulation of refractive index, and chemical etching. Finite-length, radially corrugated fibers may be used as couplers. Corrugated tapered fibers are used as high energy throughput probes in scanning near-field optical microscopy