Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation up to 100 TeV toward the Galactic Center with MAGIC

Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28}  cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25}  cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.

Bounds on Lorentz Invariance Violation from MAGIC Observation of GRB 190114C

On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording the most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of the speed of light in vacuo for photons as predicted by several quantum gravity models. Based on a set of assumptions on the possible intrinsic spectral and temporal evolution, we obtain competitive lower limits on the quadratic leading order of speed of light modification.

Medical students exchange program organized by Croatian Medical Students International Committee, 1996-2000

AIM

To assess the interest of Croatian medical students in going to foreign countries and foreign medical students' interest in coming to Croatia for one-month professional and research clerkship in the period from 1996 to 2000.

METHOD

Data were obtained from contracts between Croatian Medical Students' International Committee and other National Member Organizations of the International Federation of Medical Students' Associations; from student Application forms; reports of the Local Committees of Croatian Medical Students' International Committee summed up in a Statistical form and used for statistical analysis in the International Federation of Medical Students' Associations; and from Cards of acceptance and Cards of confirmation.

RESULTS

The number of available bilateral exchange places increased from 28 in 1996 to 66 in 1999. Croatian students going for clerkship abroad used 65.8% of available places and foreign students realized 59.3% of all places available in Croatia. Most of the exchange students chose clinical, whereas only a small number chose preclinical clerkship. The most visited were the departments of medicine and general surgery. All the students preferred doing their clerkships in August. Most foreign students came from Italy, Spain, Slovakia, and Hungary. Croatian students preferred to go to Italy, Spain, Egypt, and Finland.

CONCLUSION

Political problems strongly affected students' interest in doing clerkship in a certain country. Croatia needs to attract more students from different countries and to increase the interest of Croatian students in doing clerkship in Eastern European countries.

Studies of responsiveness in the R-EGFR and Rcerb-B2 oncogenes spaces: a customized application for thyroid lesions

Among variety of diagnostic approaches suitable for clinical analysis of thyroid lesions, the two oncogenes (R-EGFR and Rcerb-B2) are believed to be of discriminative power. In a retrospectively collected patient material we have defined different lesion types (normal tissue, benign and malignant tumours). Those were taken as class definitions in analysis performed to assign discriminating performance. Standard multivariate statistics has not performed satisfactory partly due to the data distribution and partly due to presence of the noise. Therefore we have developed a method for the classification purpose, which was based on principle of minimising generalised classification error. Results of the separation between carcinoma and normal tissue reached accuracy 70%, other classification attempts ended up in poor results. In general, misclassifications could be explained with the data quality (noise) and, when it came to benign lesions, with responsiveness of the oncogenes to tumour tissues.

Postoperative management of patients with Hemopump support after coronary artery bypass grafting

BACKGROUND

In this study, we describe postoperative monitoring, pharmacologic therapy, and hemodynamic responses in patients receiving Hemopump support after postcardiotomy heart failure.

METHODS

The Hemopump was used in 24 patients with severe left ventricular dysfunction after coronary artery bypass grafting.

RESULTS

Fourteen patients (58%) were weaned from the Hemopump. Low to moderate doses of a combination of catecholamines, phosphodiesterase inhibitors, vasodilators, and vasoconstrictors were required to optimize Hemopump function and left ventricular unloading. Mean arterial blood pressure, mixed venous oxygen saturation, and urinary output were the most important therapy guidelines.

CONCLUSIONS

Together with our clinical protocol, the Hemopump effectively unloaded the failing ventricle while maintaining vital-organ perfusion. Doses of vasoactive drugs could be kept low. This approach to treatment provides good conditions for recovery of the stunned myocardium.

3D presentation of the nuclear cell features in quantitative cytometry

The use of an image cytometer in analysis of smears and needle aspirates provides valuable information to a cytologist. It allows to combine the overall impression, formed by visually inspecting the cells, with measured and numerically expressed nuclear cell features. Both types of information can be used efficiently only if presented to the expert in an appropriate way. Cell images (as they are seen with a microscope) are easily analysed by the experts. However, measured nuclear features can not be presented as a list of numerical values. Instead, an user interface should be developed, providing graphical presentation of the nuclear features. It should show as much information as possible and provide a comprehensive link between nuclear features and cell images. The user interface described in this paper shows nuclear features in three dimensions. It is based on a perspective projection of the three dimensional feature space onto a two dimensional surface. It allows the user to dynamically change the perspective, i.e., to look at the virtual three dimensional structure from different viewpoints. Each nucleus is represented by a single object in the three dimensional space. When an object in the three dimensional feature space is selected, the image (or the visual appearance) of the corresponding cell is shown. When a nucleus image is selected, its position in the feature space is highlighted. This provides an interconnection between nuclear cell features and cell images allowing simultaneous analysis of both types of information.