Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae

We systematically surveyed period variations of superhumps in SU UMa-type dwarf novae based on newly obtained data and past publications. In many systems, the evolution of superhump period are found to be composed of three distinct stages: early evolutionary stage with a longer superhump period, middle stage with systematically varying periods, final stage with a shorter, stable superhump period. During the middle stage, many systems with superhump periods less than 0.08 d show positive period derivatives. Contrary to the earlier claim, we found no clear evidence for variation of period derivatives between superoutburst of the same object. We present an interpretation that the lengthening of the superhump period is a result of outward propagation of the eccentricity wave and is limited by the radius near the tidal truncation. We interpret that late stage superhumps are rejuvenized excitation of 3:1 resonance when the superhumps in the outer disk is effectively quenched. Many of WZ Sge-type dwarf novae showed long-enduring superhumps during the post-superoutburst stage having periods longer than those during the main superoutburst. The period derivatives in WZ Sge-type dwarf novae are found to be strongly correlated with the fractional superhump excess, or consequently, mass ratio. WZ Sge-type dwarf novae with a long-lasting rebrightening or with multiple rebrightenings tend to have smaller period derivatives and are excellent candidate for the systems around or after the period minimum of evolution of cataclysmic variables (abridged).Comment: 239 pages, 225 figures, PASJ accepte

The future distribution of wetland birds breeding in Europe validated against observed changes in distribution

Wetland bird species have been declining in population size worldwide as climate warming and land-use change affect their suitable habitats. We used species distribution models (SDMs) to predict changes in range dynamics for 64 non-passerine wetland birds breeding in Europe, including range size, position of centroid, and margins. We fitted the SDMs with data collected for the first European Breeding Bird Atlas and climate and land-use data to predict distributional changes over a century (the 1970s-2070s). The predicted annual changes were then compared to observed annual changes in range size and range centroid over a time period of 30 years using data from the second European Breeding Bird Atlas. Our models successfully predicted ca. 75% of the 64 bird species to contract their breeding range in the future, while the remaining species (mostly southerly breeding species) were predicted to expand their breeding ranges northward. The northern margins of southerly species and southern margins of northerly species, both, predicted to shift northward. Predicted changes in range size and shifts in range centroids were broadly positively associated with the observed changes, although some species deviated markedly from the predictions. The predicted average shift in core distributions was ca. 5 km yr(-1) towards the north (5% northeast, 45% north, and 40% northwest), compared to a slower observed average shift of ca. 3.9 km yr(-1). Predicted changes in range centroids were generally larger than observed changes, which suggests that bird distribution changes may lag behind environmental changes leading to 'climate debt'. We suggest that predictions of SDMs should be viewed as qualitative rather than quantitative outcomes, indicating that care should be taken concerning single species. Still, our results highlight the urgent need for management actions such as wetland creation and restoration to improve wetland birds' resilience to the expected environmental changes in the future

Private supplementary tutoring and education policies in Europe

Cílem studie je identifikovat a zařadit vybrané evropské země do jednotlivých typů Brayovy typologie vzdělávacích politik ve vztahu k soukromému doučování (1999, 2009) a s využitím dostupných empirických studií představit zavedená opatření a jejich dopady. V první části příspěvku autor definuje soukromé doučování a jeho možné implikace pro formální vzdělávací systém a jeho spravedlnost. Ve druhé části autor představuje Brayovu typologii vzdělávacích politik ve vztahu k soukromému doučování a její vývoj v čase. Jednotlivé typy vzdělávacích politik jsou uvedeny na konkrétních příkladech evropských zemí. Ve třetí části je pak diskutována aktuální situace v České republice. V Evropě je možné identifikovat nejen země podporující soukromé doučování (Francie), ale i země tento fenomén do určité míry regulující (Litva, Německo, Slovensko), nebo i takové, které se k soukromému doučování staví nevšímavě (Chorvatsko). Uvedené příklady demonstrují různorodost podob stínového vzdělávacího systému v různých kontextech a dosavadní reakce tvůrců vzdělávací politiky na něj. Nezájem o tento fenomén v České republice ostře kontrastuje s doporučeními světových odborníků na tuto problematiku. Zároveň v našem kontextu chybí relevantní výzkumná data, o která by bylo možné opřít politické rozhodování.The objective of this paper is to identify and classify European countries according to Bray’s typology of education policies towards private supplementary tutoring (1999, 2009) and, based on literature review, show implemented regulations and their impact. In the first part the author defines private supplementary tutoring and describes its possible implications for formal education system and its equity. In the second part Bray’s typology of education policies towards private tutoring and its chronological evolution is introduced. Policy types are demonstrated on specific examples of European countries. In the third part the author discusses the current situation in the Czech Republic. In Europe it is possible to identify not only the countries which support private tutoring (France), but also countries which regulate it in some way (Lithuania, Germany, Slovakia) or also those ignoring it (Croatia). Mentioned examples show the variability of shadow education system in various contexts and up to now reactions of educational stakeholders. Ignoring of this phenomenon in the Czech Republic contrasts with the recommendations of recognized experts. At the same time we lack relevant research findings that would support political decisions

Abnormal grain growth in DC flash sintered 3‐mol% yttria‐stabilized zirconia ceramics

The origin of nonuniform microstructure and abnormal grain growth (AGG) was investigated in flash sintered 3 mol% yttria-stabilized zirconia (3YSZ) ceramics. The microstructural homogeneity decreased with increasing direct current (DC) density and with dwell time in a flash state, eventually resulting in AGG in the specimen core, the first observation of AGG in 3YSZ. Abnormal grains up to 100 μm in size emerged when the DC density was ≥160 mA/mm2, and the specimen's density exceeded 99% of theoretical, starting from the cathode and propagating toward the anode. The results are discussed by comparison with established mechanisms and previous experimental evidence concerning AGG in oxides, focusing on the possible effects of the electrochemical reduction at the cathode end of the specimen

Safe decontamination of cytostatics from the nitrogen mustards family. Part one: cyclophosphamide and ifosfamide

Irena R Štenglová Netíková,1 Luboš Petruželka,2,3 Martin Štastný,1,2 Václav Štengl1 1Department of Oncology, 1st Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic; 2Department of Material Chemistry, Institute of Inorganic Chemistry ASCR v.v.i., Rež, Czech Republic; 3Faculty of Environment, J.E. Purkyne University in Ústí nad Labem, Ústí nad labem, Czech Republic Introduction: Macrocrystalline oxides of alkaline earth metals (Mg and Ca) or light metals (Al and Ti) can respond to standard warfare agents such as sulfur mustard, soman, or agent VX. In this paper, we compared the decontamination ability of sodium hydroxide (NaOH) and sodium hypochlorite (NaClO) for nitrogen mustards (cyclophosphamide [CP] and ifosfamide [IFOS]) with a new procedure using a destructive sorbent based on nanocrystalline and nanodispersive titanium dioxide (TiO2) as a new efficient and cheap material for complete decontamination of surfaces.Methods: Titanium (IV) dioxide nanoparticles were prepared by the homogeneous hydrolysis of titanium(IV) oxysulfate (TiOSO4) with urea. The as-prepared TiO2 nanoparticles were used for the fast and safe decontamination of cytostatics from the nitrogen mustard family (CP and IFOS) in water. The adsorption–degradation process of cytostatics in the presence of TiO2 was compared with decontamination agents (0.01 M solution of sodium hydroxide and 5% solution of sodium hypochlorite). The mechanism of the decontamination process and the degradation efficiency were determined by high-performance liquid chromatography with mass spectrometry.Results: It was demonstrated that a 0.01 M solution of sodium hydroxide (NaOH) decomposes CP to 3-((amino(bis(2-chloroethyl)amino)phosphoryl)oxy)propanoic acid and sodium hypochlorite formed two reaction products, namely, IFOS and 4-hydroxy-cyclophosphamide. IFOS is cytotoxic, and 4-hydroxy-cyclophosphamide is a known metabolite of CP after its partial metabolism by CYP/CYP450. IFOS degrades in the pres¬ence of NaOH to toxic IFOS mustard. Titanium(IV) dioxide nanoparticles adsorbed on its surface CP after 5 minutes and on IFOS after 10 minutes. The adsorption–degradation process of CP in water and in the presence of TiO2 led to 4-hydroxy-cyclophosphamide and IFOS, respectively, which decayed to oxidation product 4-hydroxy-ifosfamide.Conclusion: Nanodispersive TiO2 is an effective degradation agent for decontamination of surfaces from cytostatics in medical facilities. Keywords: cyclophosphamide, ifosfamide, ifosfamide mustard, titanium(IV) dioxide, degradation, decontamination agent

The Influence of Interleukin-1β on γ-Glutamyl Transpeptidase Activity in Rat Hippocampus

Summary Brain infections as well as peripheral challenges to the immune system lead to an increased production of interleukin1beta (IL-1β), a cytokine involved in leukocyte-mediated breakdown of the blood-brain barrier. The effects of IL-1β have been reported to depend on whether the route of administration is systemic or intracerebral. Using 50-day-old male rats, we compared the effects of IL-1β on brain γ-glutamyl transpeptidase (GGT; an enzymatic marker of brain capillary endothelium) at 2, 24 and 96 h after either an intravenous (i.v.) injection of 5 μg IL-1β or an intracerebroventricular (i.c.v. -lateral ventricle) infusion of 50 ng IL-1β. When the i.v. route was used, the GGT activity underwent small but significant changes; decreasing in the hippocampus 2 h after the i.v. injection, increasing 24 h later and returning to control levels at 96 h. No significant changes in the hippocampal GGT activity were observed at 2 and 24 h following the i.c.v. infusion. The GGT activity in the hypothalamus remained unchanged regardless of the route of IL-1β administrations. Similar changes in GGT activity were revealed histochemically. The labeling was found mainly in the capillary bed, the changes being most evident in the hippocampal stratum radiatum and stratum lacunosum-moleculare. A transient increase in GGT activity at 24 h, together with a less sharp delineation of GGT-stained vessels, may reflect IL-1β induced increased turnover of glutathione and/or oxidative stress, that may in turn, be related to altered permeability of the blood-brain barrier in some neurological and mental disorders, including schizophrenia

Long-term population dynamics of the field vole from the Czech Republic

Tkadlec, E., Bejček, V., Flousek, J., Šťastný, K., Zima, J., Sedláček, F

Yeast Sec14-like lipid transfer proteins Pdr16 and Pdr17 bind and transfer the ergosterol precursor lanosterol in addition to phosphatidylinositol

Yeast Sec14-like phosphatidylinositol transfer proteins (PITPs) contain a hydrophobic cavity capable of accepting a single molecule of phosphatidylinositol (PI) or another molecule in a mutually exclusive manner. We report here that two yeast Sec14 family PITPs, Pdr16p (Sfh3p) and Pdr17p (Sfh4p), possess high-affinity binding and transfer towards lanosterol. To our knowledge, this is the first identification of lanosterol transfer proteins. In addition, a pdr16Δpdr17Δ double mutant had a significantly increased level of cellular lanosterol compared with the corresponding wild-type. Based on the lipid profiles of wild-type and pdr16Δpdr17Δ cells grown in aerobic and anaerobic conditions, we suggest that PI-lanosterol transfer proteins are important predominantly for the optimal functioning of the post-lanosterol part of sterol biosynthesis