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The nature of the recent extreme outburst of the Herbig Be/FU Ori binary Z CMa  [PDF]
T. Szeifert,S. Hubrig,M. Sch?ller,O. Schütz,B. Stelzer,Z. Mikulásek
Physics , 2009, DOI: 10.1051/0004-6361/200913704
Abstract: Z CMa is a binary system which consists of two young stars: A Herbig AeBe component "Z CMa NW" embedded in a dust cocoon and a less massive component "Z CMa SE", which is classified as a FU Orionis type star. Recently, the system showed the largest outburst reported during the almost 90 years of available observations. During the recent outburst we detect that the Z CMa system is polarized by 2.6% in the continuum and emission line spectrum, with a position angle still perpendicular to the jet. From the high level of polarization we conclude that the outburst is associated with the dust embedded Herbig AeBe NW component. The main result of our studies is that the bolometric luminosity of Z CMa remained surprisingly constant during the recent "outburst". We conclude that either the geometry of the cavity through which the light escapes from the cocoon has opened a new path, or that the screen of dust, which reflects the light toward the observer became more efficient causing the observed increase of the visual brightness by about 2.5 magnitudes.
Herding interactions as an opportunity to prevent extreme events in financial markets  [PDF]
Aleksejus Kononovicius,Vygintas Gontis
Quantitative Finance , 2014,
Abstract: A characteristic feature of complex systems in general is a tight coupling between their constituent parts. In complex socio-economic systems this kind of behavior leads to self-organization, which may be both desirable (e.g. social cooperation) and undesirable (e.g. mass panic, financial "bubbles" or "crashes"). Abundance of the empirical data as well as general insights into the trading behavior enables the creation of simple agent-based models reproducing sophisticated statistical features of the financial markets. In this contribution we consider a possibility to prevent self-organized extreme events in artificial financial market setup built upon a simple agent-based herding model. We show that introduction of agents with predefined fundamentalist trading behavior helps to significantly reduce the probability of the extreme price fluctuations events. We also test random trading control strategy, which was previously found to be promising, and find that its impact on the market is rather ambiguous. Though some of the results indicate that it might actually stabilize financial fluctuations.
Studies on the Efficacy of Twenty-Five-Hydroxycholecalciferol to Prevent Tibial Dyschondroplasia in Ross Broilers Fed Marginal Calcium to Market Age  [PDF]
K.D. Roberson,M.F. Ledwaba,R.A. Charbeneau
International Journal of Poultry Science , 2005,
Abstract: Two experiments were conducted to evaluate the effect of 25-hydroxycholecalciferol [25-(OH)D3] on tibial dyschondroplasia (TD) in broilers grown to market age. In Experiment 1, Ross cockerels were fed a mash diet marginal in calcium and adequate in phosphorus and cholecalciferol to 35 days of age in battery cages. Dietary 25-(OH)D3 was fed at 0 or 40 ug/kg during the starter (1-17 days) and grower (18-35 days) phases. During the grower phase, there was third treatment in which 25-(OH)D3 was fed to 17 days of age and then the control diet was fed to 35 days of age. Phytate phosphorus retention was measured at the end of each phase. In Experiment 2, Ross straight-run broilers were grown on litter and fed marginal calcium diets that were either crumbled (starter, 1-16 days) or pelleted (grower, 17-42 days; finisher 43-49 days). Dietary 25-(OH)D3 was fed at 0 or 69 ug/kg or a third treatment consisted of 69 ug/kg 25-(OH)D3 to 16 days and the control diet to 49 days of age. Dietary 25-(OH)D3 did not affect growth performance or incidence of TD in either experiment. In Experiment 1, phytate phosphorus retention was increased by feeding 25-(OH)D3 only in the grower phase. Bone ash at 35 days in Experiment 1 and bone strength at 48 days in Experiment 2 were not affected. The results show that Ross broilers have a low incidence of TD when marginal calcium is fed and do not require dietary 25-(OH)D3 to prevent TD or improve bone strength.
Kong Zi on Good Governance  [PDF]
Moses Aaron T. Angeles
Kritike : an Online Journal of Philosophy , 2008,
Abstract: This paper will delve into the problem of Good Governance in the light of Kong Zi. What makes up a Just State? What are the elements that constitute a prosperous Kingdom? What principles of Confucianism can we employ to achieve a just and humane society? These are the primary questions that we will try to investigate as we go along. The paper will be thus divided into three essential parts: The Notion of Li and the Sovereign, The ConfucianMoral Ideal, and lastly, The Great Commonwealth.
The enigmatic young brown dwarf binary FU Tau: accretion and activity  [PDF]
B. Stelzer,A. Scholz,C. Argiroffi,G. Micela
Physics , 2010, DOI: 10.1111/j.1365-2966.2010.17182.x
Abstract: FU Tau belongs to a rare class of young, wide brown dwarf binaries. We have resolved the system in a Chandra X-ray observation and detected only the primary, FU Tau A. Hard X-ray emission, presumably from a corona, is present but, unexpectedly, we detect also a strong and unusually soft component from FU Tau A. Its X-ray properties, so far unique among brown dwarfs, are very similar to those of the T Tauri star TW Hya. The analogy with TW Hya suggests that the dominating soft X-ray component can be explained by emission from accretion shocks. However, the typical free-fall velocities of a brown dwarf are too low for an interpretation of the observed X-ray temperature as post-shock region. On the other hand, velocities in excess of the free-fall speed are derived from archival optical spectroscopy, and independent pieces of evidence for strong accretion in FU Tau A are found in optical photometry. The high X-ray luminosity of FU Tau A coincides with a high bolometric luminosity confirming an unexplained trend among young brown dwarfs. In fact, FU Tau A is overluminous with respect to evolutionary models while FU Tau B is on the 1 Myr isochrone suggesting non-contemporaneous formation of the two components in the binary. The extreme youth of FU Tau A could be responsible for its peculiar X-ray properties, in terms of atypical magnetic activity or accretion. Alternatively, rotation and magnetic field effects may reduce the efficiency of convection which in turn affects the effective temperature and radius of FU Tau A shifting its position in the HR diagram. Although there is no direct prove of this latter scenario so far we present arguments for its plausibility.
ZI数据的统计分析综述  [PDF]
应用概率统计 , 2009,
Abstract: ZI(zero-inflated)数据就是含零过多的数据.从上世纪90年代以来,ZI数据在各个研究领域受到越来越广泛的重视,现在仍然是数据分析的热点问题之一.本文首先通过2个实例说明ZI数据的实际意义,然后介绍ZI数据分析的研究概况和最新进展.另外文章还系统介绍了各种ZI数据模型、ZI纵向数据模型及其参数估计方法,同时也介绍了ZI数据的统计诊断等问题,其中包括作者近年来的一些工作.最后,本文列出了若干有待进一步研究的问题.
Changes of hepatic biochemical parameters and proteomics in broilers with cold-induced ascites  [cached]
Wang Yongwei,Guo Yuming,Ning Dong,Peng Yunzhi
Journal of Animal Science and Biotechnology , 2012, DOI: 10.1186/2049-1891-3-41
Abstract: Ascites syndrome is still a problem for chicken industry in various parts of the world. Despite the intensive investigations of this syndrome for many years, its pathogenesis remains unclear. The objective of this study was to analyze the difference in hepatic proteomics between ascites and healthy broilers by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). Changes of biochemical parameters of liver and blood were also determined. The results indicated that red blood cell counts (RBC), hematocrit (HCT) and haemoglobin (HGB) of ascites broilers were significantly greater than healthy broilers. Hepatic malondialdehyde (MDA) level of ascites broilers was significantly increased, and the activity of total superoxide dismutase (T-SOD) was significantly decreased. Hepatic lactic acid (LD) level of ascitic broilers were significantly lower than healthy ones. Serum glucose and cholesterol level of ascites broilers were significantly increased, and serum globulin level was significantly decreased in ascites broilers. There was no significant difference in triglyceride (TG) and blood urea nitrogen (BUN) level. The activity of liver hexokinase (HK) and succinodehydrogenase (SDH) in ascites broilers was significantly decreased, and there was no significant difference in the activity of liver pyruvate kinase (PK) and Na+-K+-ATPase. The hepatic proteomics analysis showed that 18 proteins expression difference were identified between ascites and healthy broilers. These proteins were mainly involved in: 1) cytoskeleton; 2) glucose, lipids and amino acid metabolism; 3) cell secretion; 4) cell apoptosis; 5) signal transduction; 6) immune and inflammatory response; and 7) cellular redox homeostasis. Mitochondrial isoform phosphoenolpyruvate carboxykinase (M-PEPCK) mainly participates in gluconeogenesis of chicken liver. In conclusion, liver oxidative damage was significantly aggravated, but antioxidant capacity was decreased in cold-induced ascites broilers. Serum glucose level was significantly increased, with liver M-PEPCK expression higher in ascites broilers, which implied that some potential regulatory reagents may reduce ascites susceptibility and mortality under cold temperature by increasing liver gluconeogenesis level.
The Differential Rotation of FU Ori  [PDF]
Zhaohuan Zhu,Catherine Espaillat,Kenneth Hinkle,Jesus Hernandez,Lee Hartmann,Nuria Calvet
Physics , 2009, DOI: 10.1088/0004-637X/694/1/L64
Abstract: The emission of FU Orionis objects in outburst has been identified as arising in rapidly accreting protoplanetary disks, based on a number of observational properties. A fundamental test of the accretion disk scenario is that the differentially rotating disk spectrum should produce a variation of rotational velocity with the wavelength of observation, as spectra taken at longer wavelengths probe outer, more slowly rotating disk regions. Previous observations of FU Ori have shown smaller rotation at near-infrared (~ 2.2 micron) wavelengths than observed at optical (~ 0.6 micron) wavelengths consistent with the assumption of Keplerian rotation. Here we report a spectrum from the Phoenix instrument on Gemini South which shows that differential (slower) rotation continues to be observed out to ~ 5 micron. The observed spectrum is well matched by the prediction of our accretion disk model previously constructed to match the observed spectral energy distribution and the differential rotation at wavelengths < 2.2 micron. This kinematic result allows us to confirm our previous inference of a large outer radius (~ 1 AU) for the rapidly accreting region of the FU Ori disk, which presents difficulties for outburst models relying purely on thermal instability. While some optical spectra have been interpreted to pose problems for the disk interpretation of FU Ori, we show that the adjustment of the maximum effective temperature of the disk model, proposed in a previous paper, greatly reduces these difficulties.
Dietary Nickel Chloride Induces Oxidative Intestinal Damage in Broilers  [PDF]
Bangyuan Wu,Hengmin Cui,Xi Peng,Jing Fang,Zhicai Zuo,Junliang Deng,Jianying Huang
International Journal of Environmental Research and Public Health , 2013, DOI: 10.3390/ijerph10062109
Abstract: The purpose of this study was to investigate the oxidative damage induced by dietary nickel chloride (NiCl 2) in the intestinal mucosa of different parts of the intestine of broilers, including duodenum, jejunum and ileum. A total of 240 one-day-old broilers were divided into four groups and fed on a corn-soybean basal diet as control diet or the same basal diet supplemented with 300, 600 or 900 mg/kg NiCl 2 during a 42-day experimental period. The results showed that the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), and the ability to inhibit hydroxy radical and glutathione (GSH) content were significantly ( p < 0.05 or p < 0.01) decreased in the 300, 600 and 900 mg/kg groups in comparison with those of the control group. In contrast, malondialdehyde (MDA) content was significantly ( p < 0.05 or p < 0.01) higher in the 300, 600 and 900 mg/kg groups than that in the control group. It was concluded that dietary NiCl 2 in excess of 300 mg/kg could cause oxidative damage in the intestinal mucosa in broilers, which finally impaired the intestinal functions including absorptive function and mucosal immune function. The oxidative damage might be a main mechanism on the effects of NiCl 2 on the intestinal health of broilers.
Flickering in FU Orionis  [PDF]
Scott J. Kenyon,E. A. Kolotilov,M. A. Ibragimov,J. A. Mattei
Physics , 1999, DOI: 10.1086/308515
Abstract: We analyze new and published optical photometric data of FU Orionis, an eruptive pre-main sequence star. The outburst consists of a 5.5 mag rise at B with an e-folding timescale of roughly 50 days. The rates of decline at B and V are identical, 0.015 +- 0.001 mag per yr. Random fluctuations superimposed on this decline have an amplitude of 0.035 +- 0.005 mag at V and occur on timescales of 1 day or less. Correlations between V and the color indices U-B, B-V, and V-R indicate that the variable source has the optical colors of a G0 supergiant. We associate this behavior with small amplitude flickering of the inner accretion disk.
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