The XMM Newton and INTEGRAL observations of the supergiant fast X-ray transient IGR J16328-4726

The accretion mechanism producing the short flares observed from the Supergiant Fast X-ray Transients (SFXT) is still highly debated and forms a major part in our attempts to place these X-ray binaries in the wider context of the High Mass X-ray Binaries. We report on a 216 ks INTEGRAL observation of the SFXT IGR J16328-4726 (August 24-27, 2014) simultaneous with two fixed-time observations with XMM Newton (33ks and 20ks) performed around the putative periastron passage, in order to investigate the accretion regime and the wind properties during this orbital phase. During these observations, the source has shown luminosity variations, from 4x10^{34} erg/s to 10^{36} erg/s, linked to spectral properties changes. The soft X-ray continuum is well modeled by a power law with a photon index varying from 1.2 up to 1.7 and with high values of the column density in the range 2-4x10^{23}/cm^2. We report on the presence of iron lines at 6.8-7.1 keV suggesting that the X-ray flux is produced by accretion of matter from the companion wind characterized by density and temperature inhomogeneities

Daily rhythm of total activity/rest pattern in small and large domestic animals

Circadian rhythms represent an inherent property of living organ- isms that seem to guarantee an optimal functioning of the biological system, with maximum efficiency, performance and welfare.1 In mam- mals, a master clock located in the suprachiasmatic nuclei (SCN) of the hypothalamus adjusts the timing of other self-sustained oscillators in the brain and peripheral organs.2 In most species, the daily light- dark (L/D) cycle is the primary environmental stimulus (Zeitgeber) for the entrainment of the SCN pacemaker. The SCN receives light infor- mation from the retina and regulates several physiological processes by synchronizing molecular clockwork mechanisms consisted by a core group of clock genes in each cell.3 Among all physiological processes, the total locomotor activity (TLA) is one of the most susceptible to the L/D cycle. Light acutely suppresses locomotor activity in nocturnal (night active) animals such as rats and owls but promotes activity in diurnal (day active) animals like dogs and eagles.4 Since animals have a species-typical organization of activity patterns,5 the aim of this study was to compare the TLA in small and large domestic animals like rabbits, cats, dogs, goats, sheep, cows, donkeys and horses. Five clini- cally healthy female subjects from eight different species: rabbits (body weight 2.5±0.2 kg), cats (body weight 4.5±0.3 kg), dogs (body weight 13.5±1 kg), goats (body weight 40±2 kg), sheep (body weight 45±2 kg), cows (body weight 390±10 kg), donkeys (body weight 395±20) and horses (body weight 565±42) were enrolled in the study with owners consent. Animals were housed under natural photoperiod (March) 12:12 hours L/D cycle (5.30 am sunrise, 5.30 pm sunset) according to specific farm management, except for cats and dogs that lived outdoors. Water was available ad libitum and feeding was suit- able for each species. Total activity pattern was recorded for 10 days using actigraphy-based data loggers Actiwatch-Mini (Cambridge Neurotechnology Ltd, UK) placed on each animal through collars or halters according to the species. Activity was monitored with a sam- pling interval of 5 minutes. Total daily amount of activity, mount of activity during the photophase and the scotophase were calculated using Actiwatch Activity Analysis 5.06 (Cambridge Neurotechnology Ltd, UK). The Cosine peak of a rhythm (the time of the daily peak) was computed by cosinor rhythmometry6 as implement in the Actiwatch Activity Analysis 5.06 program. The temporal resolution of the locomo- tor activity data was reduced to t h bins by the averaging of all 15 data points within each 1 h bin to apply the statistical analysis. To analyze the locomotor activity a trigonometric statistical model was applied to each time series to statistically describe the periodic phenomenon, by characterizing the main rhythmic parameters according to the single cosinor procedure.6 Four rhythmic parameters were determined: mean level, amplitude, acrophase (the time at which the peak of a rhythm occurs), and robustness (strength of rhythmicity). For each animal, the mean level of the rhythm was computed as the arithmetic mean of all values in the data set (24 data points). The amplitude of the rhythm was calculated as half the maximum-minimum range of the oscilla- tion, which was computed as the difference between peak and trough. Robustness was computed as the percentage of the maximal score attained by the chi-square periodogram statistic for ideal data sets of comparable size and 24-h periodicity.7 Two-way analysis of variance (ANOVA) was used for the assessment of effects due to species and days on the daily amount of activity per 24 h. Statistical analysis showed significant differences among domestic species. The highest daily amount of activity was observed during the photophase (p<0.0001) in dogs, sheep, goats, cows, donkeys and horses, and dur- ing the scotophase (p<0.0001) in rabbits and cats. Our results show different pattern of locomotor activity in every domestic species (Figure 1), underlining a diurnal pattern of locomotor activity in dogs, goats, sheep, cows, donkeys and horses while rabbits and cats have a main nocturnal pattern. As previously observed by several authors,8-10 our study confirms that locomotor activity exhibits a robust daily rhythmicity during the photophase in dogs, cows and horses, therefore in these species the rhythm can be poorly affected by external stimuli. On the contrary, other domestic species can spontaneously shift from diur- nal to nocturnal activity pattern. Sheep with restricted night time feed- ing can shift the main bout of activity during the night8 or cats, that are considered mainly nocturnal, use to loose their rhythm when they live in symbiosis with humans.11 Therefore, the daily pattern of TLA does not depend only on L/D cycle but it can be affected by several environ- mental variables including different activities such as feeding, drink- ing, walking, grooming, playing as well as all conscious and uncon- scious movements

The IBIS soft gamma-ray sky after 1000 INTEGRAL orbits

We report here an all-sky soft gamma-ray source catalog based on IBIS observations performed during the first 1000 orbits of INTEGRAL. The database for the construction of the source list consists of all good quality data available from launch in 2002 up to the end of 2010. This corresponds to $\sim$110 Ms of scientific public observations with a concentrated coverage on the Galactic Plane and extragalactic deep exposures. This new catalog includes 939 sources above a 4.5 sigma significance threshold detected in the 17-100 keV energy band, of which 120 represent previously undiscovered soft gamma-ray emitters. The source positions are determined, mean fluxes are provided in two main energy bands, and are reported together with the overall source exposure. Indicative levels of variability are provided, and outburst times and durations are given for transient sources. Comparison is made with previous IBIS catalogs, and those from other similar missions.Comment: 65 pages, 9 figures, 2 tables, accepted for publication in ApJ Supplement

The peripartum period influenced the serum macromineral profile in mares

Changes in metabolic requirements during pregnancy may produce nutritional imbalances predisposing mares to pathological conditions. Therefore, we aimed to examine changes in serum macrominerals during the peripartum period in mares. Fifteen pregnant mares (Group A) were monitored starting at the 263rd day of pregnancy until the 21st day after foaling. Seven non-pregnant and non-lactating mares were used as a control group (Group B). Group A was subjected to blood sampling within 24-12 h after parturition (P) and then 7, 14 and 21 days after foaling (C1, C2, C3 weeks, respectively). Group B was subjected to regular sampling throughout the study to ensure that seasonal changes had no significant effect on studied parameters. Serum samples were analysed for serum electrolytes including sodium (NaC), potassium (KC), calcium (CaCC), phosphorus (PC), chloride (Cl) and magnesium (MgCC). Two-way repeated measures of analysis of variance (ANOVA) was applied to evaluate significant effects of peripartum on electrolyte concentrations. Group A showed a decrease in Cl concentrations (P D 0:011) after foaling and lower PC concentrations (P D 0:015) compared to Group B throughout the study. The linear regression model showed an increase in NaC concentrations (P D 0:002) and a gradual decrease in serum CaCC (P D 0:001) during pregnancy. Because the most significant changes in serum electrolytes occurred within 2 weeks before and 2 weeks after foaling, monitoring serum electrolyte concentrations would indicate whether the mare needs further mineral supplementation at this stage. The significant changes in a mare's macromineral profile that we observed over the peripartum provide enhanced knowledge about mineral interrelations and their modifications during specific physiological conditions such as late pregnancy and early postpartum

INTEGRAL spectral variability study of the atoll 4U 1820-30: first detection of hard X-ray emission

We study the 4-200 keV spectral and temporal behaviour of the low mass X-ray binary 4U 1820-30 with INTEGRAL during 2003-2005. This source as been observed in both the soft (banana) and hard (island) spectral states. A high energy tail, above 50 keV, in the hard state has been observed for the first time. This places the source in the category of X-ray bursters showing high-energy emission. The tail can be modeled as a soft power law component, with the photon index of ~2.4, on top of thermal Comptonization emission from a plasma with the electron temperature of kT_e~6 keV and optical depth of \tau~4. Alternatively, but at a lower goodness of the fit, the hard-state broad band spectrum can be accounted for by emission from a hybrid, thermal-nonthermal, plasma. During this monitoring the source spent most of the time in the soft state, usual for this source, and the >~4 keV spectra are represented by thermal Comptonization with kT_e~3 keV and \tau~6-7.Comment: 14 pages, 4 figures, accepted for publication by Ap

Serum protein electrophoresis pro le during late pregnancy and early post partum period in mares

The aim of the study was to determine how the physiological adjustments occurring during late pregnancy and the early post partum period affect mares’ serum protein profile. Ten pregnant mares (Group A) were monitored from the 34th week of pregnancy until the 3rd week after foaling, ten nonpregnant mares (Group B) were used as the control. Blood samples were collected every 3 weeks, from -16 to -4 weeks preceding parturition, and then every week until the 3rd week after foaling. Additional blood samples were taken within 24±12 h from foaling. The statistical analysis revealed a significant increase in albumin and α2-globulin concentrations obtained from Group A during the experimental period. Dunnet’s test also revealed significantly higher concentrations of α1-globulins, α2-globulins and γ-globulins in group A than in group B. The following results showed that the serum proteins differed in periparturient mares when compared to non-pregnant mares and significant changes in some protein fractions occurred over the experimental period. Focusing on the peripartum period, our study provides specific information about mare’s serum protein profile that could help equine practitioners to better interpret clinical data and promptly diagnose pathological conditions that might compromise the health status of the mare and, as consequence, also her foal

Increase in erythrocyte osmotic resistance following polyunsaturated fatty acids (PUFA) supplementation in show jumper horses

Osmotic fragility test has been used to study the influence of different factors on the osmotic properties of cell membranes. Considering the importance of polyunsaturated fatty acids (PUFA) in biological functions we aimed to investigate the effects of dietary PUFA supplementation on erythrocyte osmotic fragility (EOF), blood lactate (BL), hematocrit (Hct), red blood cell (RBC), hemoglobin (Hb), and mean cell volume (MCV) in 10 jumper horses. Two events occurred prior to start supplementing horse's diet and two events occurred after 4 weeks PUFA supplementation. Five horses received the PUFA supplementation (Group A), and five served as controls (Group B). Blood samples were taken before and after each course. The statistical analysis revealed significant increase in BL, Hct, RBC and Hb following exercise (P<0.0001). However, the interaction between exercise and PUFA supplementation (P=0.0083) showed PUFA-supplemented horses having a smaller rise in BL levels (P=0.0107) following exercise. Significant interactions between exercise and PUFA treatment were also found on EOF levels (P<0.05). The hemolysis curves showed PUFA-supplemented horses exhibiting a reduction in EOF compared to controls (P<0.05). Although hemolysis never occurred at 0.9% NaCl concentration, jumping exercise determined an increase in EOF (P=0.0014) at 0.8% NaCl solution. A significant interaction between exercise and PUFA treatment (P=0.0022) was found showing PUFA-supplemented horses having lower EOF (P=0.0015) following exercise. The assessment of EOF is a suitable indicator of athletic performance. The results showed that PUFA supplementation might exert beneficial effects on the horse body system by enhancing the performance in high-level show jumpers

Swift/XRT monitoring of the Supergiant Fast X-ray Transient IGR J18483-0311 for an entire orbital period

IGR J18483-0311 is an X-ray pulsar with transient X-ray activity, belonging to the new class of High Mass X-ray Binaries called Supergiant Fast X-ray Transients. This system is one of the two members of this class, together with IGR J11215-5952, where both the orbital (18.52d) and spin period (21s) are known. We report on the first complete monitoring of the X-ray activity along an entire orbital period of a Supergiant Fast X-ray Transient. These Swift observations, lasting 28d, cover more than one entire orbital phase consecutively. They are a unique data-set, which allows us to constrain the different mechanisms proposed to explain the nature of this new class of X-ray transients. We applied the new clumpy wind model for blue supergiants developed by Ducci et al. (2009), to the observed X-ray light curve. Assuming an eccentricity of e=0.4, the X-ray emission from this source can be explained in terms of the accretion from a spherically symmetric clumpy wind, composed of clumps with different masses, ranging from 10^{18}g to 5x 10^{21}g.Comment: Accepted for publication in MNRAS. 7 pages, 7 figures, 2 table

Leukocyte modifications during the first month after foaling in mares and their newborn foals

During early post-partum period both neonatal foals and peripartum mares are most susceptible to diseases. The aim of this study was to establish physiologic modifications of leukogram during the first month after foaling in mares and their newborn foals. To this end blood samples were collected from nine mares and nine foals (T0-T10), every three days from the 1st day until the 30th day after foaling. Samples were analysed for white blood cell (WBC) count and differential leucocyte counts. Two-way repeated measure analysis of variance (ANOVA) showed, in postpartum mares WBC showed significant higher values at T0 (9.02±0.76) in respect to other time points, and at T2 (8.08±0.53) and T3 (7.92±0.59) compared to T1 (6.98±0.43), whereas in foals lower WBC values at T0 (6.11±0.49) compared to other experimental periods except T1 (6.90±0.94), and at T1 compared to T8 (7.95±0.61) and T10 (7.90±0.36) were observed. The differential leucocyte counts showed significant modifications in the percentage of neutrophils (π<0.001) and lymphocytes (p<0.001) both in postpartum mares and in foals during the experimental period. Furthermore ANOVA showed significant differences between postpartum mares and foals (P<0.01) in all studied parameters, and between postpartum mares and control mares in WBC and neutrophils values. The obtained results provide suitable information about the influence of foaling on leukogram of periparturient mares and reveal WBC dynamics in newborn foals during the first month post-partum