QCSP on semicomplete digraphs

We study the (non-uniform) quantified constraint satisfaction problem QCSP(H) as H ranges over semicomplete digraphs. We obtain a complexity-theoretic trichotomy: QCSP(H) is either in P, is NP-complete or is Pspace-complete. The largest part of our work is the algebraic classification of precisely which semicompletes enjoy only essentially unary polymorphisms, which is combinatorially interesting in its own right

Effects of Diffusion on Photocurrent Generation in Single-Walled Carbon Nanotube Films

We have studied photocurrent generation in large carbon nanotube (CNT) films using electrodes with different spacings. We observe that the photocurrent depends strongly on the position of illumination, with maximum observed response occurring upon illumination at the electrode edges. The rate of change of the response decays exponentially, with the fastest response occurring for samples with the smallest electrode spacing. We show that the time response is due to charge carrier diffusion in low-mobility CNT films

Effects of some ecological factors on Dothichiza populea Sacc. et Br. growth

The aim of the present work was to evaluate the mycelial growth and fruiting vigor of Dothichiza populea Sacc. et Br. under various temperatures, pH values, and light regimes. Effect of temperature on the fungus growth was examined by growing isolates in polythermostat at 5°C to 30°C. The best mycelial growth occurred at 20°C, while at 30°C it was inhibited. Fruiting of the fungus was not observed at 5°C, 25°C, and 30°C. However, the best fruiting of the isolates appeared at 20°C. The influence of different pH of the cultivation medium (3,5-10) on the fungus isolates growth was also evaluated. Optimal pH for the fungus growth ranged between 6 and 8, while formation of reproductive organs occurred at all pH values. The influence of two light regimes (light/dark regime and continuous dark) on the fungus growth was also studied. Obtained results showed that mycelial growth and fruiting of the fungus were considerably better under the light/dark regime

Unstable compared to stable core exercises improve muscular endurance in preadolescents and adolescents: An eight-month randomized trial

Although previous studies have indicated the importance of a core strength and muscular endurance training in preadolescents and adolescents, there is a lack of evidence regarding effects of a long-term core training in unstable conditions. The purpose of this study was to compare the effects of core training in stable versus unstable body positions on core and upper body strength and muscular endurance in non-trained children aged 11-14 years. Participants were randomly assigned to either stable (SC, N=569) or unstable (UC, N=633) core-exercise group and assessed at baseline, after four, and eight months for sit-ups, dynamic trunk extension, static trunk extension, and push-ups. Repeated measures ANOVA, with time as a within factor, and exercise group, age, and gender as between factors, was employed for data analysis. Post-hoc comparisons showed greater absolute improvements after the eight-month training in UC compared to SC for all measures, age groups, and both genders (p≤.01), and greater relative improvements (differences in Cohen’s d between UC and SC ranged from 0.08 to 1.58), except for static trunk extension in 11- and 12-year-old participants. However, the differences between SC and UC in four-month effects were inconsistent. These results point out that core exercises in unstable compared to stable conditions have a greater capacity for long-term improvement of core and upper body strength and muscular endurance in non-trained preadolescents and adolescents

Classical stability and quantum instability of black-hole Cauchy horizons

For a certain region of the parameter space $\{M,e,\Lambda\}$, the Cauchy horizon of a (charged) black hole residing in de Sitter space is classically stable to gravitational perturbations. This implies that, when left to its own devices, classical theory is unable to retain full predictive power: the evolution of physical fields beyond the Cauchy horizon is not uniquely determined by the initial conditions. In this paper we argue that the Cauchy horizon of a Reissner-Nordstr\"om-de Sitter black hole must always be unstable quantum mechanically.Comment: 4 pages; uses ReVTeX; figure available upon request to [email protected]

Stability of zirconia sol in the presence of various inorganic electrolytes

Zirconia sol was prepared from zirconium oxychloride solutions by forced hydrolysis at 102ºC. The prepared sol consisted of almost spherical, monoclinic, hydrated zirconia particles 61 nm in diameter. The stability of zirconia sol in the presence of various inorganic electrolytes (LiCl, NaCl, KCl, CsCl, KBr, KI, KNO3, and K2SO4) was studied by potentiometric titration method. Dependence of the critical concentration of coagulation (CCC) on the dispersion pH was determined for all studied electrolytes. The critical coagulation concentration values, for all investigated electrolytes, are lower at higher pH. These values for all 1:1 electrolytes are equal in the range of experimental error. For a given pH value, CCCs of K2SO4 are 3-4 orders of magnitude lower than the corresponding values for 1:1 electrolytes. [Projekat Ministarstva nauke republike Srbije, br. III 45012

pH-Dependent solubility profile of desipramine hydrochloride

pH-dependent solubility profile of Desipramine hydrochloride (Ds.HCl) was studied using pH-ramp shake flask method. First, the pH value of DsHCl stock solution in 0.15 M phosphate buffer was adjusted to 11.7 in order to minimize supersaturation effect. Then, the pH value in separate samples was adjusted downwards with HCl, to prepare solutions in the pH 1.7-11.7 region. After stirring (6 h) and sedimentation (18 h), PTFE (hydrophobic, pore size 0.22 µm) filters or centrifugation were used for phase separation. Concentration was measured using HPLC with UV/Vis detection. The computer program pDISOL-X was used for data processing and refinement of equilibrium constants. Different techniques were used for solid phase characterization

pH-Dependent solubility profile of desipramine hydrochloride

pH-dependent solubility profile of Desipramine hydrochloride (Ds.HCl) was studied using pH-ramp shake flask method. First, the pH value of DsHCl stock solution in 0.15 M phosphate buffer was adjusted to 11.7 in order to minimize supersaturation effect. Then, the pH value in separate samples was adjusted downwards with HCl, to prepare solutions in the pH 1.7-11.7 region. After stirring (6 h) and sedimentation (18 h), PTFE (hydrophobic, pore size 0.22 µm) filters or centrifugation were used for phase separation. Concentration was measured using HPLC with UV/Vis detection. The computer program pDISOL-X was used for data processing and refinement of equilibrium constants. Different techniques were used for solid phase characterization

Effect of development stage on content of lignin and nutritive value of alfalfa and red clover

Ispitivan je uticaj sorte, faze razvića i otkosa na hranljivu vrednost lucerke (Medicago sativa L.) i crvene deteline (Trifolium pratense L.). Hemijski sastav je odreñen prema Weende i Detergent sistemu analize. Primenom CNCPS sistema analize utvrñena je priroda proteina i ugljenih hidrata ispitivanih biljnih vrsta, odnosno oblik u kome su ove hranljive supstance zastupljene, a koji jeste najznačajniji činilac koji odreñuje stepen i brzinu razlaganja u buragu. U ovim istraživanjima utvrñene su razlike u sadržaju lignina ispitivanih krmnih vrsta u zavisnosti od starosti biljaka, kao i uticaj lignifikacije ćelijskih zidova na svarljivost ovih hraniva. Prinos suve materije lucerke i crvene deteline zavisio je od sva tri ispitivana faktora i njihovih interakcija. Domaća sorta lucerke je produktivnija (6,8 do 2,3 t ha-1 od prvog do četvrtog otkosa, odnosno od 3,4 do 5,5 t ha-1 od prve do treće faze razvića) u odnosu na američku (5,9 do 2,2 t ha-1 od prvog do četvrtog otkosa, odnosno od 2,7 do 5,2 t ha-1 od prve do treće faze razvića). Američka populacija lucerke je sadržala veću količinu sirovih proteina (197,9 g kg-1 SM) u odnosu na domaću sortu (188,7 g kg-1 SM), dok je tetraploidna sorta crvene deteline sadržala veću količinu sirovih proteina (181,3 g kg-1 SM) u odnosu na diploidnu sortu (174,5 g kg-1 SM). Najveći sadržaj sirove celuloze je konstatovan u drugom otkosu sorte K 28 (407,6 g kg-1 SM). Faza razvića je značajno uticala na udeo lignina u suvoj materiji lucerke, čija se količina povećala od prvog do trećeg otkosa. U suvoj materiji crvene deteline je konstatovana značajno manja količina lignina. Najveća svarljivost suve materije je ustanovljena u četvrtom otkosu lucerke (754,4 g kg-1 SM), odnosno u trećem otkosu crvene deteline (820,1 g kg-1 SM), a najmanja u drugom otkosu, što se može objasniti najvećim učešćem strukturnih ugljenih hidrata u ovom otkosu...The effect of cultivar, stage of development and the cuts on the nutritional value of alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) was investigated. The chemical composition was determined according to Weende and Detergent system of analysis. Applying CNCPS system of analysis the nature of protein and carbohydrates of plant species were examined, and a form of these nutrients were present in the plants, which is the most important factor determining the rate of degradation in the rumen. In this investigation, differences in lignin content of investigated forage crops were determined depending on the plant development, and the influence of lignifications on the cell wall digestibility of these forages. Dry matter yield of alfalfa and red clover depended on all three factors and their interactions. The local variety of alfalfa, K 28, was more productive (from 6,8 to 2,3 t ha-1 from first to fourth cut, and from 3,4 to 5,5 t ha-1 from first to third stage of development) compared to US variety, G+13R+CZ (from 5,9 to 2,2 t ha-1 from first to fourth cut, and from 2,7 to 5,2 t ha-1 from first to third stage of development). US alfalfa population contained a larger amount of crude protein (197,9 g kg-1 DM) in relation to K 28 (188,7 g kg-1 DM), while the tetraploid cultivar of red clover contained a larger amount of crude protein (181,3 g kg-1 DM) in the relation to the diploid cultivar (174,5 g kg-1 DM). The highest content of crude fiber was noted in the third stage of development in the second cut of alfalfa, K 28 cultivar (407,6 g kg-1 DM). Stage of development had a significant impact on the proportion of lignin in the dry matter of alfalfa and the amount of lignin increased from the first to the third cut. Significantly lower amount of lignin was detected in the dry matter of red clover. The highest dry matter digestibility was detected in the fourth cut of alfalfa (754,4 g kg-1 DM), and the third cut of red clover (820,1 g kg-1 DM), and lowest digestibility was determined in the second cut, which could be explained by a higher amount of structural carbohydrates in this cut..