Use of ANN model in economies

In this paper, the authors made their contribution by constructing a model for the forecast of average annual net earnings in the EU countries. The model is based on the artificial neural network (ANN) use and for the needs of its creation the authors have presented their proposal for a model entry – economic variables that determine earnings. Generally, implementing an economic policy aimed at preventing stagnation of earnings levels can be achieved by running a sustainable earnings policy and our model can be used as an acceptable tool in the function of keeping that policy

Planktonski žarnjaci Boka-Kotorskog zaljeva, Crna Gora (južni Jadran)

Planktonic cnidarians were investigated at six stations in the Boka Kotorska Bay from March 2009 to June 2010 by vertical hauls of plankton net from bottom to surface. In total, 12 species of hydromedusae and six species of siphonophores were found. With the exception of the instant blooms of Obelia spp. (341 ind. m-3 in December), hydromedusae were generally less frequent and abundant: their average and median values rarely exceed 1 ind. m-3. On the contrary, siphonophores were both frequent and abundant. The most numerous were Muggiaea kochi, Muggiaea atlantica, and Sphaeronectes gracilis. Their total number was highest during the spring-summer period with a maximum of 38 ind. m-3 observed in May 2009 and April 2010. M. atlantica dominated in the more eutrophicated inner area, while M. kochi was more numerous in the outer area, highly influenced by open sea waters. This study confirms a shift of dominant species within the coastal calycophores in the Adriatic Sea observed from 1996: autochthonous M. kochi is progressively being replaced by allochthonous M. atlantica in the coastal waters, especially in the eutrophicated areas. This study provides a detailed report on the composition and abundance of the planktonic cnidarians community in this region, and should be considered as a baseline for future studies on gelatinous zooplankton.Istraživanje planktonskih žarnjaka obavljeno je na šest postaja Boka-kotorskog zaljeva od ožujka 2009. do lipnja 2010. Uzorci su sakupljeni vertikalnim potezima planktonske mreže od dna do površine. Ukupno je nađeno 12 vrsta hidromeduza i 6 vrsta sifonofora. S izuzetkom velikih nakupina vrste roda Obelia u prosincu 2009. (341 jed. m-3), prosječne vrijednosti hidromeduza rijetko su prelazile vrijednost od 1 jed. m-3. za razliku od hidromeduza, sifonofore su bile češće i brojnije, osobito u proljeće i ljeto. Najbrojnije su bile Muggiaea kochi, Muggiaea atlantica i Sphaeronectes gracilis. Najveća gustoća od 38 jed. m-3 utvrđena je u svibnju 2009 i ožujku 2010. godine. Vrsta M. atlantica je dominirala u eutroficiranom unutrašnjem dijelu zaljeva, dok je M. kochi bila brojnija u vanjskom dijelu zaljeva koji je pod jakim utjecajem otvorenog mora. Naša istraživanja su potvrdila dosadašnja saznanja za Jadransko more da u obalnim, osobito eutroficiranim područjima, novo pridošla sifonofora M. atlantica postaje dominatna u odnosu na autohtonu vrstu M. kochi. Ova istraživanja donose prve detaljne podatke o sastavu i brojnosti planktonskih žarnjaka Bokakotorskog zaljeva i predstavljaju osnovu za buduća istraživanja želatinoznog zooplanktona

Age, growth, and length-weight relationship of common nase (Chondrostoma nasus) in the Danube River near Belgrade (Serbia).

Growth parameters, length-weight relationship, and condition of the common nase (Chondrostoma nasus) in the Danube River near Belgrade were analysed on a sample (n=30) from the commercial catch, caught between March and May 2017. The total body length of the sampled individuals ranged from 26.8 to 40.1 cm, and body weight from 195 to 875 g. Age was determined from scales and individuals aged 5+, 6+ and 7+ were present in the sample, in approximately the same percentage. The regression coefficient of the length-weight relationship was b = 3.28. The value of b > 3 indicates a positive allometry, which denotes that the weight growth rate is greater than the length growth rate. The Fulton’s condition factor ranged from 0.90 and 1.36, with the mean value of 1.07. The parameters of the von Bertalanffy function were L∞ = 697.84, K = 0.08, and t0 = -1.72. The estimated phi-prime growth performance index (') was 4.60. The lengths were back-calculated using the method of Monastirsky, and the greatest relative growth increment was observed in the first and second year of life

Feeding habits of the invasive non-native black bullhead Ameiurus melas in Lake Sava (Serbia)

The black bullhead (Ameiurus melas Rafinesque, 1820) is one of the most abundant and successful non-native fish species in European freshwaters. Recent studies indicate that it is also one of the most dominant invasive fish species in Serbian waters. The aim of this research was to determine feeding habits of the black bullhead in Lake Sava, as it is known that this species may negatively affect the native fauna through predation or competition for food/space. Black bullhead samples were collected monthly from 2009 to 2012, for four days in a row. Gastro-intestinal contents were analyzed in 2349 specimens. The analysis was done macroscopically, where possible, or under a binocular microscope. Prey categories were identified to the lowest possible taxonomic level. For the diet analysis, we used the following indices: the vacuity index, frequency of occurrence, numerical abundance, and prominence value. In addition, the seasonal trophic niche breadth was calculated according to the Shannon’s diversity index. Vacuity index ranged between 72.86% and 100%. The diet spectrum consisted of 14 different prey categories from five groups: Mollusca, Crustacea, Insecta, Teleostei, and plants. Fish were the main prey in all seasons, followed by aquatic invertebrates. Plant material and terrestrial insects were used as food in relatively small quantities. Fish-egg predation was also detected. Our research confirmed that this species is an opportunistic generalist, foraging on the most abundant and available prey. Ontogenetic diet shift was also detected. The lowest value of trophic diversity was found in the largest black bullheads, while the highest was found in the medium sized individuals. The widest niche breadth was recorded in the spring of 2011

Neobična pojava jaja inćuna (Engraulis encrasicolus, Linnaeus 1758) u prosincu 2006. godine u Bokokotorskom zaljevu (Jadransko more)

Five anchovy (Engraulis encrasicolus, Linnaeus 1758) eggs were caught during an ichthyoplankton survey in Boka Kotorska Bay (south Adriatic Sea) with a PairOVET (modified CalVet) plankton net on December 5th, 2006. Eggs were found at two sampling stations (42°28’30.24” N, 18°44’41.81” E and 42°29’30.23” N, 18°40’41.84” E). It is the third record of anchovy eggs in the winter months in the Adriatic Sea.Pet jaja brgljuna (Engraulis encrasicolus, Linnaeus 1758) su uhvaćena tijekom istraživanja ihtioplanktona u Bokokotorskom zaljevu (južni Jadran) s PairOVET (izmijenjeni CalVet) i planktonskom mrežom 5. prosinca 2006. godine. Jaja su pronađena na dva mjesta uzorkovanja (42 ° 28’30 .24 “N, 18 ° 44’41 0,81” E i 42 ° 29’30 0,23 “N, 18 ° 40’41 0,84” E). Ovo je treći nalaz jaja brgljuna u zimskim mjesecima u Jadranu

Assessment of Socio-Economic Benefits from the Construction of Bypasses of Transport Infrastructure

The aim of the study is to analyse the feasibility of the second phase of the construction of the Rožaje (Montenegro) bypass project. The objectives of the construction of this bypass are to eliminate or reduce existing problems by redirecting transit flows to the bypass. Based on the observed economic costs of construction and the expected economic benefits from the project in a 20-year period, by applying Cost-Benefit Analysis (CBA), the indicators of the project economic feasibility were determined. As part of the socio-economic analysis of the project feasibility, the expected benefits for transport users (savings in travel time and savings in the vehicle exploitation costs), as well as external impacts (impacts on safety and impacts on the environment) were assessed. The analysis showed the dominant savings are in travel time and vehicle exploitation costs. The economic net present value (ENPV) of this project is positive and amounts to EUR 55 054 502, the economic internal rate of return (EIRR) is 26.88% (with a discount rate of 5%), while the benefit-cost ratio (B/CR) is 4.96. All scenarios developed within the Project Sensitivity Analysis have confirmed that this project has satisfactory economic justification

Age, growth, and length-weight relationship of common nase (Chondrostoma nasus) in the Danube River near Belgrade (Serbia).

Growth parameters, length-weight relationship, and condition of the common nase (Chondrostoma nasus) in the Danube River near Belgrade were analyzed on a sample (n=30) from the commercial catch, caught between March and May 2017. The total body length of the sampled individuals ranged from 268 to 401 mm, and body weight from 195 to 875 g. Age was determined from scales and individuals aged 5+, 6+ and 7+ were present in the sample, in approximately the same percentage. The regression coefficient of the length-weight relationship was b = 3.28. The value of b > 3 indicates a positive allometry, which denotes that the weight growth rate is greater than the length growth rate. The Fulton’s condition factor ranged from 0.90 and 1.36, with the mean value of 1.07. The parameters of the von Bertalanffy growth function were L∞ = 697.84, k = 0.08, and t0 = -1.72. The estimated phi-prime growth performance index (j') was 4.60. The lengths were back-calculated using the method of Monastyrsky, and the greatest relative growth increment was observed in the first and second year of life

Financial and socioeconomic analysis of waste management projects

U radu je provedena simulacija financijske i socioekonomske analize na hipotetskom primjeru projekta izgradnje regionalnog odlagališta. Analiza je pokazala da određeni investicijski projekti, posebno u zemljama u razvoju, zbog definiranja socioekonomski prihvatljivih cijena, imaju nisku ili negativnu stopu financijske rentabilnosti, pa se konačna odluka o realizaciji tih projekata donosi nakon provođenja socioekonomske analize. Projekti koje je moguće izvesti, financijsko održivi, ali ne i komercijalno isplativi, pogodni su za javno financiranje.A simulation of a financial and socio-economic analysis of a regional landfill construction project is conducted in the paper on a hypothetical example. The analysis showed that certain investment projects, particularly in developing countries, have a low or negative rate of financial profitability, due to the need to define a socio-economically acceptable price. The final decision on the implementation of these projects is taken after conducting an appropriate socioeconomic analysis. Projects that are technically feasible and financially sustainable, but not commercially profitable, are suitable for public funding

STATUS OF THE POTENTIALLY INVASIVE ASIAN SPECIES SCELIPHRON DEFORME IN EUROPE, AND AN UPDATE ON THE DISTRIBUTION OF S. CURVATUM (HYMENOPTERA: SPHECIDAE)

We reviewed the distribution of the two Asian species of the genus Sceliphron Klug, introduced into Europe in the late 1970s to early 1980s: S. (Hensenia) curvatum (Smith) and S. (Hensenia) deforme (Smith). Both species are routinely considered as invasive in Europe, but the status and effects of their (eventual) invasiveness are yet to be documented and evaluated. We had a focus on two areas, the Balkan Peninsula and European Russia, based principally on the study of specimens collected over the last 15 years, but we also reviewed the extensive published evidence (including some very important internet-based records), and for S. curvatum we provided a concise overview of the entire European range. We confirmed that the latter recorded species, S. deforme, has been introduced into Europe at least twice, first in the central part of European Russia, and then in the SW Balkans, and we established that these introductions originated from different source populations, belonging to a geographically widely separated Asian subspecies. Based on the most recent evidence, we confirmed successful establishment of S. deforme in both areas, and documented its ongoing spreading: from central European Russia southwards/southeastwards, and most probably from the Balkans eastwards. We rectified several erroneous country records for S. deforme (France, Italy, Bulgaria, Greece, “central Europe”), which have been extensively perpetuated in several important publications about the invasive species in Europe in the last three years (n.b. – for Greece, we have positively documented its presence only now). For S. curvatum, we added a new country record (Georgia/Abkhazia), and provided a few important earlier records from the Balkans (Serbia, Greece, Croatia, Bulgaria), which shift the timing of the previously published “first appearance” dates in the area (for two years for N Serbia and C Greece), or otherwise modify the knowledge of its history of spread. Since the most recent evidence suggests the rapid eastward advancing of both introduced species towards their respective westernmost/northernmost native range limits in western to central Asia, we considered it important to briefly review the state of knowledge about their possible coexistence in that area. We also provided detailed maps of their allochtonous ranges in Europe (currently exceeding the longitudinal span of 4,000 km) and westernmost part of their native ranges in Asia. Finally, we very briefly commented on some ecological aspects of their existence within the allochtonous range (parasitism, sex ratio, phenology)