New L2-type exponentiality tests

We introduce new consistent and scale-free goodness-of-fit tests for the exponential distribution based on the Puri-Rubin characterization. For the construction of test statistics we employ weighted L2 distance between V-empirical Laplace transforms of random variables that appear in the characterization. We derive the asymptotic behaviour under the null hypothesis as well as under fixed alternatives. We compare our tests, in terms of the Bahadur efficiency, to the likelihood ratio test, as well as some recent characterization based goodness-of-fit tests for the exponential distribution. We also compare the power of our tests to the power of some recent and classical exponentiality tests. According to both criteria, our tests are shown to be strong and outperform most of their competitors.Peer Reviewe

Polarization and angular distribution of the radiation emitted in laser-assisted recombination

The effect of an intense external linear polarized radiation field on the angular distributions and polarization states of the photons emitted during the radiative recombination is investigated. It is predicted, on symmetry grounds, and corroborated by numerical calculations of approximate recombination rates, that emission of elliptically polarized photons occurs when the momentum of the electron beam is not aligned to the direction of the oscillating field. Moreover, strong modifications to the angular distributions of the emitted photons are induced by the external radiation field.Comment: 5 pages, 3 figure

Relationship between functional capacity and the occurrence of adverse events during healthcare utilization

Introduction: Adverse events, safety incidents, and medical errors in healthcare can be avoided only by understanding the causes of their occurrence, and by applying the knowledge gained from the analysis of similar previous events. Since it is known that most adverse events do not originate from a single cause, most important is timely identification of numerous contributory states that can give us the opportunity to define a number of possible solutions to correct process errors and deficiencies in the system itself. The aim of this paper is to investigate the association between functional capacity of elderly living with cardiovascular diseases and the occurrence of adverse events during use of health-care services.Methods: Assessment of functional limitations was done using the Groningen Activity Restriction Scale (GARS). The presence of adverse events was evaluated after interviews with subjects and review of medical records. Differences in continuous numerical values between inpatient and outpatient service users were analyzed by the Mann–Whitney U-test. Spearman’s correlation coefficients of the number of actual adverse events with the presence of restrictions in daily activities were calculated. Fisher’s exact test or Fisher-Freeman-Halton test (in cases of table sizes larger than 2 × 2 format) analyzed the differences in category variables.Results: The total number of adverse events was 30 (10.1% of the total number of subjects), while there were 12 actual adverse events (40.0% of the total number of adverse events). No statistically significant correlation was found between the limitations in performing daily activities and the occurrence of actual adverse events (p = 0.173).Conclusion: The research conducted in this paper showed that the functional capacity of the elderly with chronic disease is not exclusively related with the occurrence of adverse events associated with health-care utilization

Complications of Mechanical Ventilation in Pediatric Patients in Serbia

Background. Mechanical ventilation is a frequently applied therapy in critically ill children and can be lifesaving in many cases. Clinical use of this technique has well documented benefits, but can be associated with different complications and adverse physiologic effects. Objectives. The aim of this study was to investigate the complications and clinical outcome of mechanical ventilation in Serbian pediatric patients. Material and Methods. The study encompassed 42 children with respiratory insufficiency that underwent mechanical ventilation during hospitalization over a period of 12 consecutive months. The influence of clinical and mechanical parameters on the occurrence of complications and clinical outcome were analyzed. Results. The patients were ventilated for a total of 432 days and a total of 61 complications were observed in 42 patients (97 complications per 1000 ventilation days). The most common complications associated with mechanical ventilation in Serbian pediatric patients with respiratory insufficiency were cardiovascular insufficiency (52.4%) and multiple organ failure (35.7%). High values of applied PIP ( gt 26 cm H2O), PEEP ( gt 6 cm H2O) and Tv ( gt 6 mL/kg) were associated with the occurrence of complications and negative clinical outcome. Conclusions. Complications of mechanical ventilation in the pediatric population occur frequently, but lower volumes/pressures of ventilation contribute to a decrease in incidence. Further studies are needed to examine associated risk factors and strategies to reduce the occurrence of complications and improve clinical outcome

Computer aided system for segmentation and visualization of microcalcifications in digital mammograms.

Two methods for segmentation and visualization of microcalcifications in digital or digitized mammograms are described. First method is based on modern mathematical morphology, while the second one uses the multifractal approach. In the first method, by using an appropriate combination of some morphological operations, high local contrast enhancement, followed by significant suppression of background tissue, irrespective of its radiology density, is obtained. By iterative procedure, this method highly emphasizes only small bright details, possible microcalcifications. In a multifractal approach, from initial mammogram image, a corresponding multifractal "images" are created, from which a radiologist has a freedom to change the level of segmentation. An appropriate user friendly computer aided visualization (CAV) system with embedded two methods is realized. The interactive approach enables the physician to control the level and the quality of segmentation. Suggested methods were tested through mammograms from MIAS database as a gold standard, and from clinical praxis, using digitized films and digital images from full field digital mammograph

Clinical presentation of mild cystic fibrosis in a Serbian patient homozygous for the CFTR mutation c.1393-1G gt A

We present a case of a 19-year old male with uncommon initial clinical cystic fibrosis (CF) presentation and a rare CFTR genotype, homozygote for c.1393-1G gt A mutation (legacy name 1525-1G gt A)

Histological and Immunological Changes in Uterus During the Different Reproductive Stages at Californian Rabbit (Oryctolagus cuniculus)

Rabbit is the third most commonly used animal model in different fields of scientific research, such as reproductive biology, fertility and embryo transfer studies, and immunology. This animal species, often used in antibodies production, has minority of scientific records about the immunological status of its reproductive organs. The aim of this study was to find histological and immunological changes in rabbit female reproductive tract during different reproductive stages. The study was carried out on female rabbits, divided in three groups, according to the following stages of reproductive cycle: Estrous, ovulation and pregnancy. Histological and immunohistochemical stains for T- and B-cells were performed on tissue samples of cornu uteri and cervix. T lymphocytes were predominant in all anatomical parts of the uterus, in all stages of the cycle. The highest number of those cells was recorded at estrous, while the lowest was recorded at pregnancy. Cervix expressed more immunological activity than cornu uteri. The distribution and the number of immune positive cells in the rabbit female reproductive tract depend on its hormonal status

Clinical presentation of mild cystic fibrosis in a Serbian patient homozygous for the CFTR mutation c.1393-1G gt A

We present a case of a 19-year old male with uncommon initial clinical cystic fibrosis (CF) presentation and a rare CFTR genotype, homozygote for c.1393-1G gt A mutation (legacy name 1525-1G gt A)

Tenascin-C fibronectin D domain is involved in the fine-tuning of glial response to CNS injury in vitro

Understanding processes that occur after injuries to the central nervous system is essential in order to gain insight into how the restoration of function can be improved. Extracellular glycoprotein tenascin-C (TnC) has numerous functions in wound healing process depending on the expression time, location, isoform and binding partners which makes it interesting to study in this context. We used an in vitro injury model, the mixed culture of cortical astrocytes and microglia, and observed that without TnC microglial cells tend to populate gap area in greater numbers and proliferate more, whereas astrocytes build up in the border region to promote faster gap closure. Alternatively spliced domain of TnC, fibronectin type III-like repeat D (FnD) strongly affected physiological properties and morphology of both astrocytes and microglia in this injury model. The rate of microglial proliferation in the injury region decreased significantly with the addition of FnD. Additionally, density of microglia also decreased, in part due to reduced proliferation, and possibly due to reduced migration and increased contact inhibition between enlarged FnD-treated cells. Overall morphology of FnD-treated microglia resembled the activated pro-inflammatory cells, and elevated expression of iNOS was in accordance with this phenotype. The effect of FnD on astrocytes was different, as it did not affect their proliferation, but stimulated migration of reactivated astrocytes into the scratched area 48 h after the lesion. Elevated expression and secretion of TNF-alpha and IL-1 beta upon FnD treatment indicated the onset of inflammation. Furthermore, on Western blots we observed increased intensity of precursor bands of beta 1 integrin and appearance of monomeric bands of P2Y12R after FnD treatment which substantiates and clarifies its role in cellular shape and motility changes. Our results show versatile functions of TnC and in particular FnD after injury, mostly contributing to ongoing inflammation in the injury region. Based on our findings, FnD might be instrumental in limiting immune cell infiltration, and promoting astrocyte migration within the injury region, thus influencing spaciotemporal organization of the wound and surrounding area