Galactic membership of BL Her type variable stars

As the RR Lyrae stars evolve on the Hertzsprung-Russell diagram they are believed to become short period Type II Cepheids, known as BL Her type (with a pulsation period from $1$ to $3-8$ days). Assuming that their mass is around $0.5 - 0.6 {\rm M}_{\odot}$, and that they are low metallicity objects, they were thought to belong to the halo of the Milky Way. We investigated seven Galactic short period Type II Cepheids (BL Her, SW Tau, V553 Cen, DQ And, BD Cas, V383 Cyg, and KT Com) in order to establish their membership within the Galactic structure using the kinematic approach. $Gaia$ should provide us with more data needed to conduct the study of the whole sample.Comment: 4 pages, 3 figure, proceedings of the RRL2015 - High-Precision Studies of RR Lyrae Stars conference, to appear in the Communications from the Konkoly Observator

Interpretation of Light-Quenching Factor Measurements

We observe that the pattern of the quenching factors for scintillation light from various ions, recently studied in $CaWO_4$ in connection with dark matter detectors, can be understood as a saturation phenomenon in which the light output is simply proportional to track length, independent of the ion and its energy. This observation is in accord with the high dE/dx limit of Birks' law. It suggests a simple model for the intrinsic resolution of light detectors for low energy ions, which we briefly discuss.Comment: Seven pages, seven figures, some with colo

Reconsideration of mass-distribution models

The mass-distribution model proposed by Kuzmin and Veltmann (1973) is revisited. It is subdivided into two models which have a common case. Only one of them is subject of the present study. The study is focused on the relation between the density ratio (the central one to that corresponding to the core radius) and the total-mass fraction within the core radius. The latter one is an increasing function of the former one, but it cannot exceed one quarter, which takes place when the density ratio tends to infinity. Therefore, the model is extended by representing the density as a sum of two components. The extension results into possibility of having a correspondence between the infinite density ratio and 100% total-mass fraction. The number of parameters in the extended model exceeds that of the original model. Due to this, in the extended model, the correspondence between the density ratio and total-mass fraction is no longer one-to-one; several values of the total-mass fraction can correspond to the same value for the density ratio. In this way, the extended model could explain the contingency of having two, or more, groups of real stellar systems (subsystems) in the diagram total-mass fraction versus density ratio. [Projekat Ministarstva nauke Republike Srbije, br. 176011: Dynamics and Kinematics of Celestial Bodies and Systems

Zaštita od zračenja u svetu i bivšoj Jugoslaviji i Srbiji i Crnoj Gori od otkrića x–zračenja do danas

Harmful effects of radiation and call for protection against it were recognized practically immidiatly upon the discovery of X-rays and radioactivity. A chronological review of some key events in development of radiation protection is given in this paper. First, the main activities of the ICRP since its establishment to nowadays are presented. Afterwards, a general description of some, according to the author's opinion, important events in the field of radiation protection in the former Yugoslavia and Serbia and Montenegro are given as: Vinča accident; Organization of Radiation Protection Laboratory in Vinča Institute; International Vinča Dosimetry Experiment; First Symposium and organization of the Yugoslav Radiation Protection Association; the French - Yugoslav Colloquium on radiation protection; International intercomparison experiment on nuclear accident dosimetry, and the International Summer Schools and Symposium on Radiation Protection organized in Yugoslavia. Some comments on the Three Mile Island and Chernobyl accidents are given as well. Bioindicators of low dose and dose intensity exposure are cited as one of the main problems that have to be resolved in radiation protection in the near future. Finally, as one of the main problems that, according to the author's opinion, physicists have to resolve in this field in the near future would be development of the operational dosimeter for high energy neutrons.Štetno dejstvo jonizujućeg zračenja i potreba za zaštitom uočeni su neposredno po otkriću Xzračenja i radioaktivnosti. Hronološki prikaz ključnih događaja u razvoju zaštite od zračenja izložen je u ovome radu. Najpre obrađene su osnovne aktivnosti ICRP od osnivanja do danas. Zatim sledi prikaz, po mišljenju autora, ključnih događaja na području zaštite od zračenja u bivšoj Jugoslaviji i Srbiji i Crnoj Gori, kao što su: Akcident u Vinči; Osnivanje Laboratorije za zaštitu od zračenja u Institutu Vinča Međunarodni dozimetriski eksperiment u Vinči; Prvi simpozijum i osnivanje Jugoslovenskog društva za zaštitu od zračenja; Francusko – Jugoslovenski kolokvijum na temu zaštite od zračenja; Međunarodni interkomparacioni eksperiment akcidentalnih dozimetara u Vinči i, Međunarodne letnje škole i Simpozijum zaštite od zračenja organizovani u Jugoslaviji. Kratki prikazi i ocene akcidenata na Ostrvu tri milje i Černobilju su takođe, dati. Bioindikatori malih doza i intenziteta doza navedeni su kao osnovni problem koji treba da bude razrešen u zaštiti od zračenja u budućnosti. Konačno, kao primer jednog od osnovnih problema u oblasti zaštite od zračenja koji stoji pred fizičarima jeste, po mišljenju autora, razvoj i konstrukcija operativnog dozimetra za neutrone viših energija

On Orbits for a Particular Case of Axial Symmetry

A particular case of steady state and axial symmetry - the potentialformula proposed by Miyamoto and Nagai - is studied. A number of orbits of abound test particle is determined numerically, with both, the potentialparameters and initial conditions, varied. Unlike special cases, such asnearly circular and nearly planar orbits, in the case of "truly spatial orbits" the time dependence of the coordinates becomes very complicated and amathematical treatment including any known periodic functions is hardlypossible. Bearing in mind that orbits studied in the present paper aredetermined by three elements, the authors propose the mean values over time ofthe squares of velocity components to characterize them

Poverenje i kredibilitet u obaveštavanju o riziku

In the last twenty years the concept and dynamics of trust has come into focus of many social sciences. A concept of trust is widely identified as important to social interactions; however, it is rarely well defined or characterized. The notion of trust is playing an important role especially within the context of postmodern society, risk society. Making recourse to third-party expertise and knowledge is required whenever a context requires action, but one's own experience and individual knowledge is inadequate. If one's own knowledge no longer suffices, the very act of trusting in some external authority becomes a functional necessity. In the field of risk research there is now general agreement that trust in risk management institutions may be an important factor in perception and acceptance of risks. Furthermore, trust is seen as the key to successful risk communication, while distrust may be associated with stigmatization of technologies, such as nuclear power, as well as social amplification effects following major failures of risk regulation. While the transition from trust to distrust is often rather abrupt and is reflected in a crisis of confidence, the reverse, the regaining of trust, appears to be a slow and gradual process.U poslednjih dvadeset godina, pojam i dinamika poverenja se nalaze u žiži interesovanja društvenih nauka. Mada je pojam poverenja uopšteno percipiran kao značajan za društvene interakcije, on je, ipak, retko valjano definisan ili objašnjen. Ideja poverenja igra važnu ulogu u kontekstu postmodernog društva - društva rizika. Korišćenje znanja i veštine treće strane je neophodno kad god kontekst zahteva akciju, a posedovano znanje i veština nisu dovoljni. Ako nečije lično znanje nije dovoljno, sam čin poverenja u neki spoljašnji autoritet postaje funkcionalna nužnost. U oblasti proučavanja rizika, danas postoji opšta saglasnost o tome da poverenje u institucije upravljanja rizikom može biti značajan činilac u percipiranju i prihvatanju rizika. Štaviše, poverenje se smatra ključem uspešne komunikacije rizika, dok nepoverenje može biti povezano sa stigmatizacijom tehnologije, kao što je, na primer, nuklearna energija, kao i efektom socijalne amplifikacije nakon krupnijih grešaka u upravljanju rizicima. Dok je prelazak s poverenja u nepoverenje često nagao i trenutan, a očitava se u krizi kredibiliteta, obratni čin, to jest, ponovno uspostavljanje poverenja je spor i postepen proces

The phytopathogen powdery mildew affects food-searching behavior and survival of Coccinella septempunctata

The diet of entomophagous coccinellids is mainly based on aphids and other food sources such as pollen, nectar, or fungal spores. Knowledge of their foraging behavior on plants infected by powdery mildew and their survival on fungal spores is currently limited. In this study, we investigated the olfactory response of Coccinella septempunctata to odor emission of barley plants infected by powdery mildew and their survival on fungal spores in the presence or absence of aphids. Odors released by powdery-mildew infected plants were more attractive for ladybirds compared to those of uninfected controls. After 3days, the survival rate of ladybirds feeding only on powdery-mildew spores was less than 50%, while for ladybirds feeding exclusively on Rhopalosiphum padi aphids, the survival rate was close to 90%. After 15days, the highest survival rate (almost 80%) was observed for ladybirds feeding on plants with both aphids and powdery mildew. Molecular analyses confirmed the presence of fungal spores in ladybird guts when feeding either on powdery mildew or on a mixed diet. Our results provide new insights into foraging behavior of entomophagous coccinellids revealing the potential of powdery mildew to be utilized as important non-essential food in a mixed diet, but also its lethal effect if consumed alone

Efficient genetic transformation of Lotus corniculatus L. using a direct shoot regeneration protocol, stepwise hygromycin B selection, and a super-binary Agrobacterium tumefaciens vector

Cotyledons from 6-day-old Lotus corniculatus cv. Bokor seedlings, transversally cut into two halves, were capa­ble of regenerating buds without intervening callus formation. The explants were co-cultivated with the Agrobacterium tumefaciens LBA4404/pTOK233 superbinary vector carrying the uidA-intron gene and the genes hpt and nptII. They were cultured for 14 days on a regeneration medium, then subjected to a stepwise hygromycin B selection procedure consisting of gradually increasing antibiotic concentrations (5-15 mg L-1) over 21 weeks. Transformed shoots were obtained within 5 months after co-cultivation. Out of 124 initially co-cultivated explants, 52 (42%) plants survived hygromycin B selection. The presence of transgenes in regenerated plants was verified by β-glucuronidase histochemical assays and PCR analysis for the presence of uidA gene sequences. Hygromycin B-resistant and PCR-positive T0 plants were cultured in the greenhouse to produce flowers and seeds. The obtained data demonstrate that the reported transformation protocol could be useful for introducing agriculturally important genes into the new L. corniculatus cultivar Bokor

Arthroscopic Anatomy of the Knee Joint and Portals

Knee arthroscopy is one of the most used operative treatments in orthopedic surgery. The first knee arthroscopy was performed by Prof. K. Takagi, from Tokyo, Japan, in 1920. With further improvement, he made the first black and white photos of the inside of the knee (1932) and, soon, the first color photos (1939). Independently from Takagi, Dr. Eugen Bircher from Arau, Switzerland, in 1921 published the results of 20 “arthro-endoscopies,” and that was the first time the word “arthroscopy” was mentioned in literature. In New York, USA, Dr. Michael Burman described in detail the incision points and technique of joint spreading that we use today. In 1957, Dr. Masaki Watanabe published the first Atlas of Arthroscopy. The first Arthroscopy Course in English language was held in Philadelphia, USA, in 1972. The International Arthroscopy Association, with Dr. Watanabe as president, was established in 1974. In clinical knee arthroscopy, the following division proved to be very useful: the medial compartment, the lateral compartment, the central part or central pivot, and the femoropatelar compartment. In this chapter, the normal anatomy of each of this part will be described in detail, with the descriptions of basic knee arthroscopy portals