ABSTRACT
OJ 287 is a BL Lacertae type quasar in which the active galactic nucleus (AGN) outshines the host galaxy by an order of magnitude. The only exception to this may be at minimum light when the ...AGN activity is so low that the host galaxy may make quite a considerable contribution to the photometric intensity of the source. Such a dip or a fade in the intensity of OJ 287 occurred in 2017 November, when its brightness was about 1.75 mag lower than the recent mean level. We compare the observations of this fade with similar fades in OJ 287 observed earlier in 1989, 1999, and 2010. It appears that there is a relatively strong reddening of the B− V colours of OJ 287 when its V-band brightness drops below magnitude 17. Similar changes are also seen in V− R, V− I, and R− I colours during these deep fades. These data support the conclusion that the total magnitude of the host galaxy is V = 18.0 ± 0.3, corresponding to MK = −26.5 ± 0.3 in the K-band. This is in agreement with the results, obtained using the integrated surface brightness method, from recent surface photometry of the host. These results should encourage us to use the colour separation method also in other host galaxies with strongly variable AGN. In the case of OJ 287, both the host galaxy and its central black hole are among the biggest known, and its position in the black hole mass–galaxy mass diagram lies close to the mean correlation.
We developed a method that allows to classify the light curves of eclipsing binaries of the W UMa type (EW) with respect to their intrinsic variability. The algorithm measures several features of ...light curves, such as the amplitude of the O’Connell effect, the separation and location of maxima brightness as well as depths of the minima in subsequent orbital periods. This method is capable of distinguishing systems with presumed magnetic activity present from these without it, as well as recognizing systems with starspots migration and those with other types of intrinsic variability manifestation. The classification is done in an automatic way without a time consuming, visual inspection of light curves.
Insulin-like growth factor-I is involved in mammary gland development, promoting proliferation and inhibiting apoptosis of mammary epithelial cells (MECs). Mitogenic actions of IGF-I are mainly ...mediated by the phosphatidylinositol-3 kinase (PI3K)/Akt signaling pathway. We have found that in the presence of IGF-I bovine BME-UV1 MECs cultured on reconstituted basement membrane form large spheroids with disrupted polarity and no cavity in the center. These cells showed enhanced phosphorylation of Akt, decreased level of cleaved caspase-3, and sustained proliferative activity throughout the 16-d period of 3-dimensional culture. Inhibition of the PI3K/Akt pathway by a specific inhibitor of PI3K, LY294002, resulted in the restoration of the normal acinar phenotype. However, this effect was noted only when LY294002 was added in the second week of 3-dimensional culture, which corresponded with the time of cell cycle arrest and polarity formation under control conditions. Normal development of acini was also obtained when BME-UV1 cells were treated simultaneously with IGF-I and 17β-estradiol. The addition of 17β-estradiol regulated Akt activation, enabling the subsequent initiation of polarization processes. 17β-Estradiol also increased the level of IGFBP-3 protein in MECs cultured on Matrigel in the presence of IGF-I. The presented results indicate important interactions between signaling pathways activated by estrogen and IGF-I, which regulate alveologenesis in bovine mammary gland.
The estimation of acute phase proteins (APP), which are recognized as inflammation markers is a good method for animal health monitoring. Several factors such as obesity, age and sex are also known ...to modulate APP status. We evaluated the influence of pregnancy and lactation in 65 clinically healthy dairy Holstein-Friesian dairy cows, 2nd÷4th lactation, chosen from 3 different dairy farms located in South West part of Poland. Bovine C-reactive protein (CRP), haptoglobin and fibrinogen were assayed using commercial ELISA kits. The highest values of CRP and haptoglobin were observed in cows during the first month after calving. The highest concentrations of fibrinogen was found in a group of cows prior to expected date of parturition and the level of this protein in blood plasma was decreasing during lactation. The significant differences of analyzed APPs among cows before delivery, during first month after calving and in lactation (1-3 months after delivery) suggested that factors like pregnancy and stage of lactation would have an influence on their concentration.
A stop signal paradigm in combination with heart rate measures were used to test the hypothesis of deficient inhibitory processing in boys with attention deficit hyperactivity disorder (ADHD). The ...authors measured the inhibitory process initiated by a stop signal by observing its success, its latency using a horse race model, and its impact on the timing of the heartbeat. Boys with ADHD performed well and showed appropriate psychophysiological changes. Inhibition latencies were longer in the boys with ADHD, particularly those with concurrent oppositional defiant disorder, than in the controls. Cardiac evidence suggested that greater preparation was associated with inhibition failures in controls, but not in the boys with ADHD. Boys with ADHD seem capable of attending carefully to control responses, but this control appears less effective and arguably is more effortful than in other boys.
Verapamil is a L-type voltage gated calcium channels inhibitor (VGCCI), which is a highly prescribed drug used in the treatment of hypertension, angina pectoris, cardiac arrhythmia and cluster ...headaches. Its common use caused its appearance in water environment. VGCC inhibit epinephrine release and cause many neuro-hormonal changes influencing also fish behavior. Siamese fighting fish was chosen to study the influence of verapamil given to the water on the beginning of experiment in 3 different concentrations of 0 (control), 8 and 160 μg · L-1, on aggressive behavior in these fish. The experimental fish were placed in individual glass containers for 3 weeks and the mirror test was used. The highest concentration led to a significant modulation of fish behavior after 1 week and the lower dose caused statistically significant behavioral changes after 2 weeks of verapamil treatment. Siamese fighting fish males exposed to verapamil had longer latencies to the first chase - 12.6 s (8 μg · L-1 of verapamil) and 18.8 s (160 μg · L-1 of verapamil) compared to 5.6 s in the control group, decreased attack frequency and shorter duration of these attacks. The number of attacks within 10 min was decreased from 38.3 in the control group to 27.1 and 16.1, respectively. Also the total duration of these attacks decreased from 354.8 (control) to 326.4 (decrease statistically insignificant) and to 194.8 s in verapamil treated groups. It was shown, that even relatively low concentrations of verapamil in water may have adverse effects on fish and probably other living organisms.
The paper presents investigations of the relationship between the biochemical parameters and vital signs in dairy cows. We analyzed the welfare and functioning of a dairy herd using biochemical ...parameters and vital signs. Life and biochemical parameters were examined. In the model indicators useful for monitoring the herd are: the age of the cows, the number of cows' lactating, daily amount of received milk, length of lactation period for cows in the herd, the length of inter-calving period for cows, the number of days to effective insemination, the amount of protein in the feed, the level of β-oxidation in leucocytes, glucose transport through red blood cells and plasma insulin. Based on the results the mathematical model was designed allowing the presentation of a cybernetic model of cow's organism. There was constructed a multi-equation model which determined the relationships between the selected variables describing the state of dairy cows in the herd and variables that characterize their welfare with its statistical verification.
This work studies the significance of the lightcurve intrinsic variability in the numerical modeling of contact binaries. Using synthetic light curves we are showing that the starspot-based intrinsic ...variability increases the apparent mass ratio by \(\Delta q=5\)%. For systems with orbital period \(P>0.3 d\) the effect of intrinsic variability averaged over long time cancels each other out with the Kepler Mission-like phase smearing. Further, we analyse 47 totally eclipsing Kepler Mission contact binaries. We found a sharp cutoff of the intrinsic variability at P = 0.45 d. With the light curve numerical modeling and observational relations we derive physical parameters of the 47 systems. At least 53% of binaries have a possible third companion. 21 binaries show the O`Connell effect in the averaged phase curve. 19 of them have a primary maximum lower than the secondary, suggesting a stationary dark region on the trailing side. Using the P = 0.45 d cutoff we propose a new approach on the Period-Color relation. The only parameter correlating with the magnitude of the intrinsic variability is the apparent effective temperature ratio. We conclude that instead of describing the system parameters, the A/W-subtype division should be applicable only to the lightcurves, as a tentative phenomenon.
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