Biotechnological Aspects of Dietary Fiber Use in the Production of Fermented Dairy Products

This article presents research results of the chemical composition, physical and chemical properties and biotechnological potential of dietary fiber concentrates (DFCs) obtained from secondary raw materials for the production of carrot and pumpkin juices.It has been established that DFCs, along with dietary fibers (cellulose, hemicellulose, pectin, lignin), contain soluble sugars, nitrogenous substances and carotenoids, which determine their physiological activity and technological properties when used in dairy products fermented with probiotics.The effect of DFCs on the fermentation kinetics of dairy-vegetable mixtures with a starter containing lacto-, bifidobacteria and propionic acid microorganisms was studied. The optimal concentration and the degree of dispersion of carrot and pumpkin DFCs was determined. The findings can be used to ensureoptimal intensification of the fermentation process and the production of probiotic fermented milk drinks with a pleasant taste. Keywords: dietary fiber, secondary raw materials, functional dairy products, prebiotics, probiotics, enzyme kinetics, probiotic drink

Implementation of random numbers in academic performance assessment

В статье описывается методика создания уникальных индивидуальных экзаменационных заданий для контроля знаний, полученных студентами в течение курса, а также опыт их применения.The article describes a method that allows generation of unique individual examination tasks to be used to assess students' academic performance during the course, and reports some implementation experience

Optical photometry and spectral classification in the field of the open cluster NGC 6996 in the North America Nebula

We present and discuss broad band CCD $UBV(I)_C$ photometry and low resolution spectroscopy for stars in the region of the open cluster NGC 6996, located in the North America Nebula. The new data allow us to tightly constrain the basic properties of this object. We revise the cluster size, which in the past has been significantly underestimated. The width of the Main Sequence is mainly interpreted in terms of differential reddening, and indeed the stars' color excess $E_{B-V}$ ranges from 0.43 to 0.65, implying the presence of a significant and evenly distributed dust component. We cross-correlate our optical photometry with near infrared from 2MASS, and by means of spectral classification we are able to build up extinction curves for an handful of bright members. We find that the reddening slope and the total to selective absorption ratio $R_V$ toward NGC 6996 are anomalous. Moreover the reddening corrected colors and magnitudes allow us to derive estimates for the cluster distance and age, which turn out to be $760 \pm 70 pc$ ($V_{0}-M_{V} = 9.4 \pm 0.2$) and $\sim 350$ Myr, respectively. Basing on our results, we suggest that NGC 6996 is located in front of the North America Nebula, and does not seem to have any apparent relationship with it.Comment: 19 pages, 12 eps figures, in press in A&

Polarization in young open cluster NGC 6823

We present multiwavelength linear polarimetric observations of 104 stars towards the region of young open cluster NGC 6823. The polarization towards NGC 6823 is dominated by foreground dust grains and we found the evidence for the presence of several layers of dust towards the line of sight. The first layer of dust is located approximately within 200 pc towards the cluster, which is much closer to the Sun than the cluster (~ 2.1 kpc). The radial distribution of the position angles for the member stars are found to show a systematic change while the polarization found to reduce towards the outer parts of the cluster and the average position angle of coronal region of the cluster is very close to the inclination of the Galactic parallel (~ 32 degree). The size distribution of the grains within NGC 6823 is similar to those in general interstellar medium. The patchy distribution of foreground dust grains are suggested to be mainly responsible for the both differential reddening and polarization towards NGC 6823. The majority of the observed stars do not show the evidence of intrinsic polarization in their light.Comment: 16 pages, 6 tables, 11 figures, Accepted for publication in MNRA

How Good a Clock is Rotation? The Stellar Rotation-Mass-Age Relationship for Old Field Stars

The rotation-mass-age relationship offers a promising avenue for measuring the ages of field stars, assuming the attendant uncertainties to this technique can be well characterized. We model stellar angular momentum evolution starting with a rotation distribution from open cluster M37. Our predicted rotation-mass-age relationship shows significant zero-point offsets compared to an alternative angular momentum loss law and published gyrochronology relations. Systematic errors at the 30 percent level are permitted by current data, highlighting the need for empirical guidance. We identify two fundamental sources of uncertainty that limit the precision of rotation-based ages and quantify their impact. Stars are born with a range of rotation rates, which leads to an age range at fixed rotation period. We find that the inherent ambiguity from the initial conditions is important for all young stars, and remains large for old stars below 0.6 solar masses. Latitudinal surface differential rotation also introduces a minimum uncertainty into rotation period measurements and, by extension, rotation-based ages. Both models and the data from binary star systems 61 Cyg and alpha Cen demonstrate that latitudinal differential rotation is the limiting factor for rotation-based age precision among old field stars, inducing uncertainties at the ~2 Gyr level. We also examine the relationship between variability amplitude, rotation period, and age. Existing ground-based surveys can detect field populations with ages as old as 1-2 Gyr, while space missions can detect stars as old as the Galactic disk. In comparison with other techniques for measuring the ages of lower main sequence stars, including geometric parallax and asteroseismology, rotation-based ages have the potential to be the most precise chronometer for 0.6-1.0 solar mass stars.Comment: For a brief video explaining the key results of this paper, see http://www.youtube.com/user/OSUAstronom

ВЛИЯНИЕ ВИРУСА ГЕРПЕСА ЧЕЛОВЕКА 6 ТИПА НА ТЕЧЕНИЕ ПИЕЛОНЕФРИТА У ДЕТЕЙ

The authors studied the incidence of detection of human herpes virus type 6 (HHV 6) infection markers in 207 children aged from 1 year to 7 years (126 children with acute pyelonephritis and 81 child in the control group with no signs of urinary tract infection). It was found out that of all the children studied ≥ 89,2% of the patients with acute pyelonephritis and ≥ 65,3% of the children without urinary tract infection are infected with HHV 6. The characteristic of HHV — 6 infection in children with acute pyelonephritis is the presence of active viral replication with the presence of HHV 6 DNA in the blood. This fact indicates the risk of repeated episodes of the disease and is the condition for administration of antiviral and / or immunotropic therapy. The authors proved low predictive value of HHV 6 DNA detection in urine of children with acute pyelonephritis. Изучена частота встречаемости маркеров инфекции вирусом герпеса человека 6 типа (HHV 6) у 207 детей в возрасте от 1-го года до 7-ми лет (126 детей с острым пиелонефритом и 81 ребенок контрольной группы без признаков инфекции мочевой системы); установлено, что ≥ 89,2% пациентов с острым пиелонефритом и ≥ 65,3% детей, не имеющих инфекции мочевой системы, инфицированы HHV 6. Выявлены особенности течения HHV 6-инфекции у детей с острым пиелонефритом: наличие активной вирусной репликации с обнаружением ДНК HHV 6 в крови, что свидетельствует о риске развития повторного эпизода заболевания и является показанием для назначения противовирусной и/или иммунотропной терапии. Доказана низкая прогностическая значимость выявления ДНК HHV 6 в моче у детей с острым пиелонефритом.

In Search of Possible Associations between Planetary Nebulae and Open Clusters

We consider the possibility of cluster membership for 13 planetary nebulae that are located in close proximity to open clusters lying in their lines of sight. The short lifetimes and low sample size of intermediate-mass planetary nebulae with respect to nearby open clusters conspire to reduce the probability of observing a true association. Not surprisingly, line of sight coincidences almost certainly exist for 7 of the 13 cases considered. Additional studies are advocated, however, for 6 planetary nebula/open cluster coincidences in which a physical association is not excluded by the available evidence, namely M 1-80/Berkeley 57, NGC 2438/NGC 2437, NGC 2452/NGC 2453, VBRC 2 & NGC 2899/IC 2488, and HeFa 1/NGC 6067. A number of additional potential associations between planetary nebulae and open clusters is tabulated for reference purposes. It is noteworthy that the strongest cases involve planetary nebulae lying in cluster coronae, a feature also found for short-period cluster Cepheids, which are themselves potential progenitors of planetary nebulae.Comment: Accepted for publication in PASP (December 2007

The Spitzer c2d Survey of Weak-Line T Tauri Stars. III. The Transition from Primordial Disks to Debris Disks

We present 3.6 to 70 {\mu}m Spitzer photometry of 154 weak-line T Tauri stars (WTTS) in the Chamaeleon, Lupus, Ophiuchus and Taurus star formation regions, all of which are within 200 pc of the Sun. For a comparative study, we also include 33 classical T Tauri stars (CTTS) which are located in the same star forming regions. Spitzer sensitivities allow us to robustly detect the photosphere in the IRAC bands (3.6 to 8 {\mu}m) and the 24 {\mu}m MIPS band. In the 70 {\mu}m MIPS band, we are able to detect dust emission brighter than roughly 40 times the photosphere. These observations represent the most sensitive WTTS survey in the mid to far infrared to date, and reveal the frequency of outer disks (r = 3-50 AU) around WTTS. The 70 {\mu}m photometry for half the c2d WTTS sample (the on-cloud objects), which were not included in the earlier papers in this series, Padgett et al. (2006) and Cieza et al. (2007), are presented here for the first time. We find a disk frequency of 19% for on-cloud WTTS, but just 5% for off- cloud WTTS, similar to the value reported in the earlier works. WTTS exhibit spectral energy distributions (SEDs) that are quite diverse, spanning the range from optically thick to optically thin disks. Most disks become more tenuous than Ldisk/L* = 2 x 10^-3 in 2 Myr, and more tenuous than Ldisk/L* = 5 x 10^-4 in 4 Myr.Comment: 40 pages, 13 figures, 4 tables. Accepted for publication in ApJ on September 20, 201

Inequality, Fiscal Capacity and the Political Regime: Lessons from the Post-Communist Transition

Using panel data for twenty-seven post-communist economies between 1987-2003, we examine the nexus of relationships between inequality, fiscal capacity (defined as the ability to raise taxes efficiently) and the political regime. Investigating the impact of political reform we find that full political freedom is associated with lower levels of income inequality. Under more oligarchic (authoritarian) regimes, the level of inequality is conditioned by the state’s fiscal capacity. Specifically, oligarchic regimes with more developed fiscal systems are able to defend the prevailing vested interests at a lower cost in terms of social injustice. This empirical finding is consistent with the model developed by Acemoglu (2006). We also find that transition countries undertaking early macroeconomic stabilisation now enjoy lower levels of inequality; we confirm that education fosters equality and the suggestion of Commander et al (1999) that larger countries are prone to higher levels of inequality.http://deepblue.lib.umich.edu/bitstream/2027.42/57211/1/wp831 .pd

uvby-Hbeta CCD Photometry of NGC 1817 and NGC 1807

We have investigated the area of two NGC entries, NGC 1817 and NGC 1807, with deep CCD photometry in the uvby-Hbeta intermediate-band system. The photometric analysis of a selected sample of stars of the open cluster NGC 1817 yields a reddening value of E(b-y)= 0.19$\pm$0.05, a distance modulus of V0-MV= 10.9$\pm$0.6, a metallicity of [Fe/H]= -0.34$\pm$0.26 and an age of log t = 9.05$\pm$0.05. Our measurements allow us to confirm that NGC 1807 is not a physical cluster.Comment: 11 pages, 8 figures, A&A in pres