Identification and Characterization of Alkaline Uranyl(2 +) Phosphates

The spontaneous precipitation in the systems U02(N03)2- -MOH-HaP04--H20 and U02(N03)2-MNOa-H3P04- H20 (M = = Li, Na, K, Rb, Cs) is examined. The formation of alkaline- uranyl(2+) phosphates polyhydrates is detected: M[U02P04] · · n H20 (n = 4 for M = Li, n = 3 for M = Na, K, Rb and n = 2.5 for M =Cs). The X-ray powder patterns of these compounds are determined and compared with that of H30[U02P04] · 3 H20. A close structural relation within this series is observed. The size of the alkaline ionic species in the particular compound affects the content of crystalline water in the unit cell

Spontaneous Precipitation in the System Uranyl(2+ )nitrate Potassium Hydroxide - Phosphoric Acid - Water

The precipitation system U02(NOs)2-KOH-H3P04-H20 (at 298 K) aged for 1 day and for 30 days is examined ([U02(NOs)2] = = 1 · 10-a mol dm-3, [KOH] varied from 1 · 10-6 to 6 · 10-1 mol dm-3, [H3P04] from 2 · 10-4 to 6 · 10-1 mol dm-3 and 1.5 <pH< 11.5). The precipitation and phase boundaries are determined. The solid phases U02HP04 · 4 H20(s) and (U02)s(P04)2 · 8 H20 are stable at [KOH] < 1 · 10-3 mol dm-3, 1.5 <pH < 4.0. Uranates precipitate at pH > 9.5. The stability region of KU02P04 · 3 H20(s) is found at high concentrations of KOH and H3P04. X-ray diffraction pattern of this compound is given. According to the precipitation boundary after 30 days (equilibrium conditions) the solubility product of KU02P04 · 3 H20 is determined: log ([K+] · · [U022+] [P043-]) = -- 26.28 (at I =0 mol dm-3)

Precipitation and Solubility of Uranyl - Orthophosphates. I. Heterogeneous Equilibria in Solutions of: U02(NOa)2 - HaP04

The precipitation and dissolution of uranium(VI) from aqueous solutions of orthophosphoric acid (2 X 10-a to 6 M) and uranyl nitrate (3 X 10- 5 to 0.5 M) has been investigated by turbidimetric and chemical analyses, fluorescent and electron microscopy. The concentration ranges where (U02 )g(P04 h and U02HP04 precipitates were observed 24 hours and 30 days after mixing are represented by typical precipitation bodies. The morphology of the precipitated particles is shown by electron micrographs. At equilibrium conditions (U02)a(P04 ) 2 is stable at concentrations of total phosphate in the mother liquor lower than 1.5 X 10-3 M. At total phosphate concentrations higher than 5 X 10- 3 M, U02 HP0 1 is stable

Penile morphology in six populations of Branchipus schaefferi Fischer, 1834 (Crustacea: Branchiopoda) from Serbia

Male genital morphology of six populations of Branchipus schaefferi from different locations in Serbia is described. Both qualitative and quantitative morphological traits were taken into consideration. The majority of males from lowland parts of the country (Pannonian Plane) had a long sickle-curved or arched spine situated on the basal part of the penis. Males sampled in the south-eastern part of the country (the region of Stara Planina Mountains) possessed short, straight or slightly bowed basal spine. A distal penile part appeared as a more stable character than the proximal one. Males from one of the examined populations possessed roundish and spineless penile tip, a feature heretofore not described in B. schaefferi.Acta Zoologica Bulgarica (2017), 69(1): 17-2

Sexual selection can reduce mutational load in Drosophila subobscura

According to theoretical predictions sexual selection can reduce mutational load through male mating success. Males of good genetic quality should be more successful in matings, compared to the males of low genetic quality, thus in this way females can prevent deleterious alleles to be transmitted to the next generation. We tested this hypothesis through set up of two experimental groups from same genetic pool, where in one group genetic quality was manipulated by ionizing radiation. Within each group opportunity for choosing mates was imposed: males and females had no choice or had multiple choice. Mutational load was measured through the variability of different fitness components: fecundity and egg-to-adult viability. Our results indicate that sexual selection can reduce mutational load, only for fecundity. Group with the presence of female choice exhibited higher fecundity than group in which sexual selection was experimentally eliminated, but only in 'irradiated' group. There was no overall difference in egg-to-adult viability between different sexual selection regimes in any of the group. It should be considered that sexual selection can cause sexual conflict, and potential opposite effects of sexual selection and sexual conflict on fitness. Genetic structure of populations, in terms of the level of mutational load, is an important factor which can determinate the role of sexual selection.Prema teorijskim očekivanjima seksualna selekcija može smanjivati mutaciona opterećenja u populacijama, preko uspešnosti mužjaka u parenju. Mužjaci koji su boljeg genetičkog kvaliteta bi trebalo da budu uspešniji u parenju od mužjaka lošijeg genetičkog kvaliteta. Na taj način bi ženke mogle da smanje prenošenje štetnih alela u sledeću generaciju. Ova hipoteza je testirana uspostavljanjem dve eksperimentalne grupe od istog genetičkog pula jedinki, pri čemu su u jednoj mutacije indukovane jonizujućim zračenjem. Unutar svake grupe je nametnuta mogućnost izbora u parenju: mužjaci i ženke nisu imali izbor, ili su imali višestruki izbor. Mutaciona opterećenja su merena preko dve komponente adaptivne vrednosti: fekunditeta i preživljavanja od stadijuma jaja do adulta. Dobijeni rezultati ukazuju da seksualna selekcija može imati uticaj na smanjivanje mutacionih opterećenja ali samo za fekunditet. U prisustvu seksualne selekcije su vrednosti fekunditeta bile veće u odnosu na vrednosti koje su dobijene kad je seksualna selekcija eksperimentalno uklonjena, ali samo u okviru 'ozračene' grupe. Razlike u preživljavanju od jaja do adulta između različitih režima seksualne selekcije nisu dobijene ni u jednoj od grupa. Kako seksualna selekcija često uzrokuje i seksualni konflikt, treba uzeti u obzir njihovo potencijalno delovanje u suprotnim pravcima na adaptivnu vrednost. Genetička struktura populacija, koja podrazumeva i veličinu mutacionih opterećenja, može biti važan faktor od koga će i zavisiti delovanje seksualne selekcija na adaptivnu vrednost.Projekat ministarstva br. 17301

Cytogenetic findings in Serbian patients with Turner's syndrome stigmata

Cytogenetic findings are reported for 31 female patients with Turner's syndrome. Chromosome studies were made from lymphocyte cultures. Non-mosaicism 45, X was demonstrated in 15 of these patients, whereas only three were apparently mosaic. Eight patients showed non-mosaic and four patients showed mosaic structural aberrations of the X-chromosome. One non-mosaic case displayed a karyotype containing a small marker chromosome. Conventional cytogenetics was supplemented by fluorescence in situ hybridization (FISH) with an X-specific probe to identify the chromosomal origin of the ring and a 1q12-specific DNA probe to identify de novo balanced translocation (1;9) in one patient. To our knowledge, this is the first finding of karyotype 45,X,t(1;9) (cen;cen)/46,X,r(X),t(1;9)(cen;cen) in Turner's syndrome. The same X-specific probe was also used to identify a derivative chromosome in one patient

Nucleation of Calcium Phosphate from Solutions at Physiological pH

In a previous paper1 it was shown that when phase transition from aqueous solutions occurs at metastable equilibrium, the stoichiometry of the nucleating phase can be conveniently evaluated from the precipitation boundary2 • The method was applied to calcium phosphates nucleating in the pH range 6.3 , to 9.1 from solutions containing calcium chloride and sodium phosphate at constant total phosphate concentration 1 X 10-3 M. The calcium phosphate ratio of the nucleating phase was found to be 1.5 and the formation of an amorphous metastable precursor to hydroxyap atite was concluded. Because of its implications on biological calcification it was of interest to reexamine this result restricting the experiments to the physiological pH region (pH 7.25-7.5), but taking into account possible variations of total phosphate and total calcium concentrations. This was done as part of more extensive investigations of the precipitation of calcium phosphates from aqu eous solutions and from media containing 0.15 M sodium chlorid e

Sexual selection can reduce mutational load in Drosophila subobscura

According to theoretical predictions sexual selection can reduce mutational load through male mating success. Males of good genetic quality should be more successful in matings, compared to the males of low genetic quality, thus in this way females can prevent deleterious alleles to be transmitted to the next generation. We tested this hypothesis through set up of two experimental groups from same genetic pool, where in one group genetic quality was manipulated by ionizing radiation. Within each group opportunity for choosing mates was imposed: males and females had no choice or had multiple choice. Mutational load was measured through the variability of different fitness components: fecundity and egg-to-adult viability. Our results indicate that sexual selection can reduce mutational load, only for fecundity. Group with the presence of female choice exhibited higher fecundity than group in which sexual selection was experimentally eliminated, but only in 'irradiated' group. There was no overall difference in egg-to-adult viability between different sexual selection regimes in any of the group. It should be considered that sexual selection can cause sexual conflict, and potential opposite effects of sexual selection and sexual conflict on fitness. Genetic structure of populations, in terms of the level of mutational load, is an important factor which can determinate the role of sexual selection.Prema teorijskim očekivanjima seksualna selekcija može smanjivati mutaciona opterećenja u populacijama, preko uspešnosti mužjaka u parenju. Mužjaci koji su boljeg genetičkog kvaliteta bi trebalo da budu uspešniji u parenju od mužjaka lošijeg genetičkog kvaliteta. Na taj način bi ženke mogle da smanje prenošenje štetnih alela u sledeću generaciju. Ova hipoteza je testirana uspostavljanjem dve eksperimentalne grupe od istog genetičkog pula jedinki, pri čemu su u jednoj mutacije indukovane jonizujućim zračenjem. Unutar svake grupe je nametnuta mogućnost izbora u parenju: mužjaci i ženke nisu imali izbor, ili su imali višestruki izbor. Mutaciona opterećenja su merena preko dve komponente adaptivne vrednosti: fekunditeta i preživljavanja od stadijuma jaja do adulta. Dobijeni rezultati ukazuju da seksualna selekcija može imati uticaj na smanjivanje mutacionih opterećenja ali samo za fekunditet. U prisustvu seksualne selekcije su vrednosti fekunditeta bile veće u odnosu na vrednosti koje su dobijene kad je seksualna selekcija eksperimentalno uklonjena, ali samo u okviru 'ozračene' grupe. Razlike u preživljavanju od jaja do adulta između različitih režima seksualne selekcije nisu dobijene ni u jednoj od grupa. Kako seksualna selekcija često uzrokuje i seksualni konflikt, treba uzeti u obzir njihovo potencijalno delovanje u suprotnim pravcima na adaptivnu vrednost. Genetička struktura populacija, koja podrazumeva i veličinu mutacionih opterećenja, može biti važan faktor od koga će i zavisiti delovanje seksualne selekcija na adaptivnu vrednost.Projekat ministarstva br. 17301

Note on the fauna of Drosophila (Diptera: Drosophilidae) and the first record of Opomyza florum (Diptera: Opomyzidae) from mt. Goč, Serbia

Fauna of Drosophilidae in Serbia has been studied for 40 years. This paper presents the results of faunistic research conducted on Mt. Goč in June 2011 in two forests (beech and oak), which are significantly different in the type of vegetation and microclimatic factors. In the oak forest eight species of Drosophila were registered, while in the beech forest only five species were recorded. A relatively small number of species recorded is, among other things, the result of extremely bad weather conditions during the collection attempts. An interesting non-drosophilid fly was also found in the sample - Opomyza florum Fabricius, 1794 (Diptera: Opomyzidae). Since there is very little data concerning the distribution of O. florum in Serbia, this paper is an invitation to entomologists to further study this species, including faunistical, ecological and behavioral aspects, keeping in mind its potential economic impact.Fauna Drosophilidae se u Srbiji izučava već 40 godina. U ovom radu su prikazani rezultati faunističkog istraživanja sprovedenog na Goču u junu 2011. godine, u dve šume (bukovoj i hrastovoj), koje se znatno razlikuju u tipu vegetacije i mikroklimatskim faktorima. U hrastovoj šumi je registrovano 8 vrsta Drosophila, a u bukovoj 5 vrsta. Relativno mali broj registrovanih vrsta je, između ostalog, posledica ekstremno loših vremenskih uslova tokom sakupljanja mušica. U uzorku sakupljenih muva utvrđeno je i prisustvo žute žitne muve, Opomyza florum Fabricius 1794 (Diptera: Opomyzidae). Imajući u vidu da postoji vrlo malo podataka koji se tiču distribucije O. florum u Srbiji, ovaj rad je i poziv entomolozima u smislu daljeg izučavanja ove vrste, sa faunističkog, ekološkog i aspekta ponašanja, s obzirom na njen potencijalni ekonomski značaj.Projekat ministarstva br. 17301