The flora of the volcanic island of Brusnik (central Dalmatia, Croatia)

Research into the vascular flora of the volcanic island of Brusnik was carried out in the period from 2000 to 2002. A total of 28 higher plant species was found, four of them being noted for the first time. Of the 41 taxa noted by previous authors, 24 were confirmed, but 17 were not. According to analysis of life forms, the most numerous are Therophyta (13 species, 46.4%), followed by Chamaephyta (seven species, 25%), Phanerophyta (four species, 14.3%), Hemicryptophyta (three species, 10.7%) and Geophyta (one species, 3.6%). After analysis of floral elements, autochthonous taxa are grouped into three categories: Mediterranean floral element (18 species, 66.6%), South European floral element (five species, 18.5%) and widespread plants (four species, 14.8%). Especially important plants in the flora of Brusnik are Frankenia pulverulenta L., a very rare species in the Croatian flora and the Illyrian-Adriatic endemic plants Centaurea ragusina L., Limonium vestitum (Salmon) Salmon subsp. brusnicense Trinajsti} and Senecio leucanthemifolius Poir. var. reichenbachii Fiori. The results of our research show that the island of Brusnik belongs, in phytogeographical terms, to the Mediterranean zone proper of the Mediterranean region

The correlation of metal content in medicinal plants and their water extracts

The quality of some medicinal plants and their water extracts from South East Serbia is determined on the basis of metal content using atomic absorption spectrometry. The two methods were used for the preparation of water extracts, to examine the impact of the preparation on the content of metals in them. Content of investigated metals in both water extracts is markedly lower then in medicinal plants, but were higher in water extract prepared by method (I), with exception of lead content. The coefficients of extraction for the observed metal can be represented in the following order: Zn > Mn > Pb > Cu > Fe. Correlation coefficients between the metal concentration in the extract and total metal content in plant material vary in the range from 0.6369 to 0.9956. This indicates need the plants to be collected and grown in the unpolluted area and to examine the metal content. The content of heavy metals in the investigated medicinal plants and their water extracts is below the maximum allowable values, so they are safe to use

Značaj histeroskopije u vantelesnom oplođenju

Introduction: Pathological states of the uterus cavity, such as endometrial polyp, submucous myoma, intrauterine synechiae or septum, are considered to be negative influence on IVF success. Hysteroscopy is able to diagnose the possible IVF causes of failure and surgically remove them in the same act. Due to frequent cavum pathology, the idea of applying hysteroscopy, even prior to the first IVF, has been seriously considered. Different studies have also stated that the endometrium proinflammatory response after a local endometrial injury can increase the possibility of successful implantation after an embryo transfer in the IVF cycle. Objective: The aim of the project is to determine the frequency of the cavum pathology with patients in IVF process and to examine the impact of hysteroscopy on IVF outcome in cases of post surgical treatment of pathological states of the uterus, with no pathological substratum and after a local endometrial injury. Method: A study group consisted of 114 patients with hysteroscopy performed 30 to 50 days before the IVF cycle. The control group consisted of 151 patients. The local endometrial injury was done in a way not described in any literature available. Results: Having analyzed the obtained results, almost identical pathology frequency was confirmed prior to the first IVF cycle, as with the next, in nearly a third of the cases. Statistically viewed, significantly higher rates of implantation and pregnancies were obtained after hysteroscopy, in comparison to the control group. Probability of a positive IVF outcome rises 2,1 time after a local endometrial injury, when compared to the control group. Conclusion: Hysteroscopy is minimally invasive, safe and simple method providing higher possibility of conceiving after IVF. This research suggests the protocol for IVF preparing couples to be accompanied by obligatory hysteroscopy even prior to the first IVF cycle

A Proposed Method for Determining Propulsion Coefficient Based on Testing Motor Freighters on Danube Waterway Network

The paper presents a proposal of mathematical models for the determination of propulsion coefficient, eta pp, intended for the analysis of motor freighters applied on the river watercourses. As the main paper contribution three different model types are developed, depending on the variable which contributes to eta pp value. These variables are: 1. the freighter sailing velocity, (nu); 2. the installed capacity of the main drive motor of outboard unit, (N-inst); 3. the combination of these two variables, (N-inst, nu). The models are verified on the examples of several motor freighters which are applied at Danube river. The special attention is paid to the determination of the optimum approximation function in each case. In all three cases it is a quadratic function. The correlation coefficient for the comparison in all analyzed examples is higher than 0.87, being even higher than 0.99 for the first model

Display probability of symbol errors for MQAM on Rician fading channel based on MGF method

We present a new method for calculating the probability of error per symbol (Symbol Error Probability, SEP) of M-ary Quadrature Amplitude Modulation (MQAM) over a slow, flat, identically independently distributed Rician fading channels. Since fading is one of the major constraints in wireless communications, the diversity modulation technique is used for the efficient transfer of message signals. Exact analysis of error probability per symbol for MQAM, transmitted over Rician fading channels, is performed by N branches of diversity reception using maximum ratio of signal-to-noise power (maximal-ratio-combining, MRC), where the information in the channel on the receiver side is known. We also analyzed the performances of MQAM over Rician fading channels are here also analyzed. Approximate formula is used to represent SEP for MQAM transmitted over Gaussian channels. Boundary condition for the approximation is M≥4 and 0≤SNR≤30 dB

Display probability of symbol errors for MQAM on Rician fading channel based on MGF method

We present a new method for calculating the probability of error per symbol (Symbol Error Probability, SEP) of M-ary Quadrature Amplitude Modulation (MQAM) over a slow, flat, identically independently distributed Rician fading channels. Since fading is one of the major constraints in wireless communications, the diversity modulation technique is used for the efficient transfer of message signals. Exact analysis of error probability per symbol for MQAM, transmitted over Rician fading channels, is performed by N branches of diversity reception using maximum ratio of signal-to-noise power (maximal-ratio-combining, MRC), where the information in the channel on the receiver side is known. We also analyzed the performances of MQAM over Rician fading channels are here also analyzed. Approximate formula is used to represent SEP for MQAM transmitted over Gaussian channels. Boundary condition for the approximation is M≥4 and 0≤SNR≤30 dB

A Proposed Method for Determining Propulsion Coefficient Based on Testing Motor Freighters on Danube Waterway Network

The paper presents a proposal of mathematical models for the determination of propulsion coefficient, eta pp, intended for the analysis of motor freighters applied on the river watercourses. As the main paper contribution three different model types are developed, depending on the variable which contributes to eta pp value. These variables are: 1. the freighter sailing velocity, (nu); 2. the installed capacity of the main drive motor of outboard unit, (N-inst); 3. the combination of these two variables, (N-inst, nu). The models are verified on the examples of several motor freighters which are applied at Danube river. The special attention is paid to the determination of the optimum approximation function in each case. In all three cases it is a quadratic function. The correlation coefficient for the comparison in all analyzed examples is higher than 0.87, being even higher than 0.99 for the first model

Bioinformatics analysis of SARS coronavirus genome polymorphism

BACKGROUND: We have compared 38 isolates of the SARS-CoV complete genome. The main goal was twofold: first, to analyze and compare nucleotide sequences and to identify positions of single nucleotide polymorphism (SNP), insertions and deletions, and second, to group them according to sequence similarity, eventually pointing to phylogeny of SARS-CoV isolates. The comparison is based on genome polymorphism such as insertions or deletions and the number and positions of SNPs. RESULTS: The nucleotide structure of all 38 isolates is presented. Based on insertions and deletions and dissimilarity due to SNPs, the dataset of all the isolates has been qualitatively classified into three groups each having their own subgroups. These are the A-group with "regular" isolates (no insertions / deletions except for 5' and 3' ends), the B-group of isolates with "long insertions", and the C-group of isolates with "many individual" insertions and deletions. The isolate with the smallest average number of SNPs, compared to other isolates, has been identified (TWH). The density distribution of SNPs, insertions and deletions for each group or subgroup, as well as cumulatively for all the isolates is also presented, along with the gene map for TWH. Since individual SNPs may have occurred at random, positions corresponding to multiple SNPs (occurring in two or more isolates) are identified and presented. This result revises some previous results of a similar type. Amino acid changes caused by multiple SNPs are also identified (for the annotated sequences, as well as presupposed amino acid changes for non-annotated ones). Exact SNP positions for the isolates in each group or subgroup are presented. Finally, a phylogenetic tree for the SARS-CoV isolates has been produced using the CLUSTALW program, showing high compatibility with former qualitative classification. CONCLUSIONS: The comparative study of SARS-CoV isolates provides essential information for genome polymorphism, indication of strain differences and variants evolution. It may help with the development of effective treatment

Ispitivanje energetske efikasnosti solarnih modula u zavisnosti od njihove zaprljanosti u realnim klimatskim uslovima u Nišu

The doctoral dissertation provides basic information on solar radiation, photovoltaic conversion of solar radiation, solar cells and solar modules and their output parameters, and a literature review of the current research in the world about dust and solar modules soiling. In addition, the results of the measurement of electrical parameters of clean and solar modules soiled with carbon, calcium carbonate and soil are given. Furthermore, a comparative overview of the results of the energy efficiency tests of the clean and solar modules soiled with carbon, calcium carbonate and soil is given. In the end, the results of the measurement of the electrical parameters of the clean and solar modules soiled with accumulated soot from the chimney of the boiler room, located in the basement of the Faculty of Sciences and Mathematics in Niš, are presented