The first record of black bullhead Ameiurus melas (Pisces, Ictaluridae) in Serbian waters

On the 14th of June, 2005, in the Danube side channel "Jojkić" (N 44°50'33.1’’, E 20°27'46.1’’) near Belgrade, we recorded the presence of A. melas, ranging in weight (W) from 11.2 g to 135.6 g, and standard length (Ls) from 70 mm to 173 mm. Specimens were obtained from professional fishermen, who caught them with gill nets, as well from sport fishermen using fishing roads. Also, on 28th of May, 2005, on the lake "Savsko jezero" (N 44°47'20.1’’, E 20°24'54.6’’), we collected two specimens with gill nets. They were held in an aquarium until the 20th of June, when they were analyzed. Their weight (W) was 48.8 g and 97.5 g, their standard length (Ls) 145 mm and 183 mm, respectively.nul

Population viability analysis and potential of its application to Danube sturgeons

Sturgeon species in the Danube River basin have experienced severe decline. Besides overexploitation, habitat loss, and pollution, they are further endangered by lack of efficient policy and management, as well as by serious lack of knowledge about their life history. Although population viability analysis (PVA) could represent an extremely valuable tool to cope with these problems, it has not so far been applied to Danube populations. This paper represents an assess­ment of different PVA methods and models developed for sturgeon species. It analyzes their results, main advantages, drawbacks, and problems, and discusses the possibility of applying PVA to sturgeon populations in the Danube River basin.Populacije jesetarskih vrsta u basenu Dunava su doživele ozbiljan pad brojnosti. Pored prekomernog izlova, gubitka staništa i zagađenja, dodatno su ugrožene nedostatkom efikasne legislative i upravljanja, kao i ozbiljnim nedostatkom znanja o njihovom životnom ciklusu. I ako analiza vijabilnosti populacija(PVA) može Predstavljati veoma koristan metod u rešavanju ovih problema, do sada nije primenjivana na dunavske populacije. Ovaj rad predstavlja procenu različitih PVA metoda i modela razvijenih za jesetarske vrste. U radu se analiziraju njihovi rezultati, glavne prednosti, nedostatci i glavni problemi na koje se nailazilo, i diskutuje se o mogućnosti njihove primene na populacije jesetri u basenu Dunava.Projekat ministarstva br. 14304

The Ituwa Surge deposits of the Holocene Ngozi caldera, Mbeya Region, Tanzania

The Ituwa Surge deposits belong to the Holocene Ngozi volcano (volcano number 222164 of the Smithsonian Institute Global Volcanism Program; Siebert et al. 2010) of the Rungwe Volcanic Province (RVP; Harkin 1960; Lenhardt and Oppenheimer 2014). They are named after their type locality and place of best exposure, the village of Ituwa in the Mbeya Region of southwestern Tanzania. Volcanism within the RVP started approximately 9 Ma ago and can be divided into a Late Miocene (*9.2–5.4 Ma), a Late Pliocene-Early Pleistocene (*3–1.6 Ma) and a Mid-Pleistocene-recent (\*0.6 Ma) phase (Ebinger et al. 1989, 1993; Ivanov et al. 1999).http://link.springer.com/journal/5312016-04-30hb201

Privredni ribolov na Dunavu u Srbiji

U radu se daje pregled slatkovodnog ribarstva sa aspekta upravljanja, ekspolatacije ribljih resursa, tržišta ribom, legislative koja uređuje delatnost ribarstva, kao i problemi sektora ribarstva u Srbiji. Istraživanje i analiza privrednog ribolova na Dunavu kroz Srbiju (588 km toka) sprovedeno je prikupljanjem podataka ribarske statistike za period od 1948. do 2010. godine, njihovim unošenjem u elektronsku bazu i analiziranjem uz korišćenje različitih metoda. Statistički podaci uključuju ukupan ulov, ulov rekreativnog i privrednog ribolova, ulov privredno značajnih vrsta i alohtonih vrsta. Korišćenjem anketnog upitnika za ribare dobijeni su podaci o demografskoj strukturi ribara koji se bave ribarenjem kao osnovnom delatnošću, o sastavu ulova, koliko je ribarstvo perspektivna privredna grana i koji su problemi i potencijalna rešenja. Većina ribara pripada starosnoj grupi koja je u opsegu od 45 do 50 godina. Privredni ribolov je važna ekonomska delatnost i predstavlja osnovni izvor prihoda za većinu ribara. Tržište slatkovodnom ribom je neuređena oblast koja zavisi od ličnog zalaganja i odgovornosti pojedinca koji ima interes u prodaji ribe. Ribarstvo na Dunavu u Srbiji je već dugi niz godina u procesu tranzicije ka tržišnoj ekonomiji. Dugoročne fluktuacije hidroloških podataka (vodostaj) upoređivane su sa fluktuacijama godišnjeg ulova ribe iz Dunava kako bi se uočila eventualna međusobna zavisnost i uporedili njihovi trendovi. Rezultati ovog istraživanja treba da posluže kao pregled stanja sektora sa svim postojećim nedostacima koje treba ispraviti u cilju što uspešnijeg upravljanja ribarstvom na Dunavu i ostalim rekama u Srbiji gde je zastupljen privredni ribolov

Population viability analysis and potential of its application to Danube sturgeons

Sturgeon species in the Danube River basin have experienced severe decline. Besides overexploitation, habitat loss, and pollution, they are further endangered by lack of efficient policy and management, as well as by serious lack of knowledge about their life history. Although population viability analysis (PVA) could represent an extremely valuable tool to cope with these problems, it has not so far been applied to Danube populations. This paper represents an assess­ment of different PVA methods and models developed for sturgeon species. It analyzes their results, main advantages, drawbacks, and problems, and discusses the possibility of applying PVA to sturgeon populations in the Danube River basin.Populacije jesetarskih vrsta u basenu Dunava su doživele ozbiljan pad brojnosti. Pored prekomernog izlova, gubitka staništa i zagađenja, dodatno su ugrožene nedostatkom efikasne legislative i upravljanja, kao i ozbiljnim nedostatkom znanja o njihovom životnom ciklusu. I ako analiza vijabilnosti populacija(PVA) može Predstavljati veoma koristan metod u rešavanju ovih problema, do sada nije primenjivana na dunavske populacije. Ovaj rad predstavlja procenu različitih PVA metoda i modela razvijenih za jesetarske vrste. U radu se analiziraju njihovi rezultati, glavne prednosti, nedostatci i glavni problemi na koje se nailazilo, i diskutuje se o mogućnosti njihove primene na populacije jesetri u basenu Dunava.Projekat ministarstva br. 14304

The first record of black bullhead Ameiurus melas (Pisces, Ictaluridae) in Serbian waters

On the 14th of June, 2005, in the Danube side channel "Jojkić" (N 44°50'33.1’’, E 20°27'46.1’’) near Belgrade, we recorded the presence of A. melas, ranging in weight (W) from 11.2 g to 135.6 g, and standard length (Ls) from 70 mm to 173 mm. Specimens were obtained from professional fishermen, who caught them with gill nets, as well from sport fishermen using fishing roads. Also, on 28th of May, 2005, on the lake "Savsko jezero" (N 44°47'20.1’’, E 20°24'54.6’’), we collected two specimens with gill nets. They were held in an aquarium until the 20th of June, when they were analyzed. Their weight (W) was 48.8 g and 97.5 g, their standard length (Ls) 145 mm and 183 mm, respectively.nul

First record of the North American paddlefish (Polyodon spathula walbaum, 1792) in the Serbian part of the Danube river

nul

Seismic detection of rockslides at regional scale: examples from the Eastern Alps and feasibility of kurtosis-based event location

Seismic records can provide detailed insight into the mechanisms of gravitational mass movements. Catastrophic events that generate long-period seismic radiation have been studied in detail, and monitoring systems have been developed for applications on a very local scale. Here we demonstrate that similar techniques can also be applied to regional seismic networks, which show great potential for real-time and large-scale monitoring and analysis of rockslide activity. This paper studies 19 moderate-sized to large rockslides in the Eastern Alps that were recorded by regional seismic networks within distances of a few tens of kilometers to more than 200&thinsp;km. We develop a simple and fully automatic processing chain that detects, locates, and classifies rockslides based on vertical-component seismic records. We show that a kurtosis-based onset picker is suitable to detect the very emergent onsets of rockslide signals and to locate the rockslides within a few kilometers from the true origin using a grid search and a 1-D seismic velocity model. Automatic discrimination between rockslides and local earthquakes is possible by a combination of characteristic parameters extracted from the seismic records, such as kurtosis or maximum-to-mean amplitude ratios. We attempt to relate the amplitude of the seismic records to the documented rockslide volume and reveal a potential power law in agreement with earlier studies. Since our approach is based on simplified methods we suggest and discuss how each step of the automatic processing could be expanded and improved to achieve more detailed results in the future.</p

Probing Nuclear forces beyond the drip-line using the mirror nuclei 16^{16}N and 16^{16}F

Radioactive beams of $^{14}$O and $^{15}$O were used to populate the resonant states 1/2$^+$, 5/2$^+$ and $0^-,1^-,2^-$ in the unbound $^{15}$F and $^{16}$F nuclei respectively by means of proton elastic scattering reactions in inverse kinematics. Based on their large proton spectroscopic factor values, the resonant states in $^{16}$F can be viewed as a core of $^{14}$O plus a proton in the 2s$_{1/2}$ or 1d$_{5/2}$ shell and a neutron in 1p$_{1/2}$. Experimental energies were used to derive the strength of the 2s$_{1/2}$-1p$_{1/2}$ and 1d$_{5/2}$-1p$_{1/2}$ proton-neutron interactions. It is found that the former changes by 40% compared with the mirror nucleus $^{16}$N, and the second by 10%. This apparent symmetry breaking of the nuclear force between mirror nuclei finds explanation in the role of the large coupling to the continuum for the states built on an $\ell=0$ proton configuration.Comment: 6 pages, 3 figures, 2 tables, accepted for publication as a regular article in Physical Review

New pathway to bypass the 15O waiting point

We propose the sequential reaction process $^{15}$O($p$,$\gamma)(\beta^{+}$)$^{16}$O as a new pathway to bypass of the $^{15}$O waiting point. This exotic reaction is found to have a surprisingly high cross section, approximately 10$^{10}$ times higher than the $^{15}$O($p$,$\beta^{+}$)$^{16}$O. These cross sections were calculated after precise measurements of energies and widths of the proton-unbound $^{16}$F low lying states, obtained using the H($^{15}$O,p)$^{15}$O reaction. The large $(p,\gamma)(\beta^{+})$ cross section can be understood to arise from the more efficient feeding of the low energy wing of the ground state resonance by the gamma decay. The implications of the new reaction in novae explosions and X-ray bursts are discussed.Comment: submitte