Twenty Years of Timing SS433

We present observations of the optical ``moving lines'' in spectra of the Galactic relativistic jet source SS433 spread over a twenty year baseline from 1979 to 1999. The red/blue-shifts of the lines reveal the apparent precession of the jet axis in SS433, and we present a new determination of the precession parameters based on these data. We investigate the amplitude and nature of time- and phase-dependent deviations from the kinematic model for the jet precession, including an upper limit on any precessional period derivative of $\dot P < 5 \times 10^{-5}$. We also dicuss the implications of these results for the origins of the relativistic jets in SS433.Comment: 21 pages, including 9 figures. To appear in the Astrophysical Journa

Chance long-distance or human-mediated dispersal? How Acacia s.l. farnesiana attained its pan-tropical distribution

Acacia s.l. farnesiana, which originates from Mesoamerica, is the most widely distributed Acacia s.l. species across the tropics. It is assumed that the plant was transferred across the Atlantic to southern Europe by Spanish explorers, and then spread across the Old World tropics through a combination of chance long-distance and human-mediated dispersal. Our study uses genetic analysis and information from historical sources to test the relative roles of chance and human-mediated dispersal in its distribution. The results confirm the Mesoamerican origins of the plant and show three patterns of human- mediated dispersal. Samples from Spain showed greater genetic diversity than those from other Old World tropics, suggesting more instances of transatlantic introductions from the Americas to that country than to other parts of Africa and Asia. Individuals from the Philippines matched a population from South Central Mexico and were likely to have been direct, trans-Pacific introductions. Australian samples were genetically unique, indicating that the arrival of the species in the continent was independent of these European colonial activities. This suggests the possibility of pre-European human- mediated dispersal across the Pacific Ocean. These significant findings raise new questions for biogeographic studies that assume chance or transoceanic dispersal 2 for disjunct plant distributions

OAO-3 end of mission tests report

Twelve engineering type tests were performed on several subsystems and experiment(s) of the OAO 3 spacecraft near its end of mission. The systems tested include: Princeton experiment package (PEP), fine error system guidance, inertial reference unit, star trackers, heat pipes, thermal control coatings, command and data handling, solar array; batteries, and onboard processor/power boost regulator. Generally, the systems performed well for the 8 1/2 years life of OAO 3, although some degradation was noted in the sensitivity of PEP and in the absorptivity of the skin coatings. Battery life was prolonged during the life of the mission in large part by carefully monitoring the charge-discharge cycle with careful attention not to overcharge

Thermal seasons in northern Europe in projected future climate

Global warming acts to prolong thermal summers and shorten winters. In this work, future changes in the lengths and timing of four thermal seasons in northern Europe, with threshold temperatures 0 and 10 degrees C, are derived from bias-adjusted output data from 23 CMIP5 global climate models. Three future periods and two Representative Concentration Pathway (RCP) scenarios are discussed. The focus is on the period 2040-2069 under RCP4.5, which approximately corresponds to a 2 degrees C global warming relative to the preindustrial era. By the period 2040-2069, the average length of the thermal summer increases by nearly 30 days relative to 1971-2000, and the thermal winter shortens by 30-60 days. The timing of the thermal springs advances while autumns delay. Within the model ensemble, there is a high linear correlation between the modelled annual-mean temperature increase and shifts in the thermal seasons. Thermal summers lengthen by about 10 days and winters shorten by 10-24 days per 1 degrees C of local warming. In the mid-21st century, about two-thirds of all summers (winters) are projected to be very long (very short) according to the baseline-period standards, with an anomaly greater than 20 days relative to the late-20th century temporal mean. The proportion of years without a thermal winter increases remarkably in the Baltic countries and southern Scandinavian peninsula. Implications of the changing thermal seasons on nature and human society are discussed in a literature review.Peer reviewe

Effects of acute lying and sleep deprivation on metabolic and inflammatory responses of lactating dairy cows

Dairy cows that are restricted from lying down have a reduced ability to sleep. In other species, sleep loss is a key risk factor for disease, mediated by changes in metabolic and inflammatory responses. The cumulative effect of lying and sleep deprivation on cow health is unknown. The objective was to determine the effects of lying and sleep deprivation on metabolic and inflammatory responses of dairy cows. Data were collected from 8 multiparous and 4 primiparous lactating cows (199 +/- 44 d in milk, 77 +/- 30 d pregnant; mean +/- standard deviation) enrolled in a study using a crossover design. Each cow was exposed to 2 treatments meant to induce sleep loss: (1) human disturbance (imposed by researchers making noise or physical contact when the cow's posture suggested sleep) and (2) lying deprivation (imposed by a wooden grid placed on the pen floor). Cows experienced a 24-h baseline period (d - 1) followed by a 24-h treatment period (d 0), with a 12-d washout period between treatments. Baseline and treatment periods were imposed from 2100 to 2059 h. Cows were housed in individual pens during the acclimation period (d - 3 and - 2), d - 1, and d 0. Nonesterified fatty acid and glucose concentrations were measured at 0300, 0900, 1500, and 2059 h on d - 1 and 0. Proinflammatory cytokine mRNA [tumor necrosis factor (TNF), interleukin-1B (IL1B), and interleukin-6 (IL6)] abundance in whole-blood leukocytes, both nonstimulated and stimulated with lipopolysaccharide, were assessed at 2059 h on d -1 (end of baseline) and d 0 (end of treatment). Nonesterified fatty acids and glucose varied by time of day but were not affected by treatment or day. The abundances of TNF and IL1B from both stimulated and nonstimulated cells were higher following 24 h of lying deprivation (d 0) compared with baseline (d -1). Abundance of IL6 was increased in nonstimulated cells after lying deprivation compared with baseline. In contrast, human disturbance for 24 h did not alter TNF, IL1B, or IL6 abundance relative to baseline levels. These results suggest that a short period of lying deprivation generally increases inflammatory responses but not metabolic responses.Peer reviewe

Laser-Cluster-Interaction in a Nanoplasma-Model with Inclusion of Lowered Ionization Energies

The interaction of intense laser fields with silver and argon clusters is investigated theoretically using a modified nanoplasma model. Single pulse and double pulse excitations are considered. The influence of the dense cluster environment on the inner ionization processes is studied including the lowering of the ionization energies. There are considerable changes in the dynamics of the laser-cluster interaction. Especially, for silver clusters, the lowering of the ionization energies leads to increased yields of highly charged ions.Comment: 10 pages, 11 figure

A Note on the Statistical Mechanics of Violent Relaxation of Phase Space Elements of Different Densities

The statistical mechanical investigation of Violent Relaxation of phase space elements of different densities first derived by Lynden-Bell (1967) is re-examined. It is found that the mass independence of the equations of motion of Violent Relaxation calls for a constraint on the volume of the phase space elements used to formulate the statistical mechanical description of Violent Relaxation. In agreement with observations of astrophysical objects believed to have been subject to Violent Relaxation (e.g. clusters of galaxies), the coarse grained phase space distribution $\bar{f}$ of the final state in the non-degenerate limit turns into a superposition of Maxwellians of a common velocity dispersion. Thus, the velocity dispersion problem present in the investigation of Lynden-Bell (1967) is removed.Comment: AASTeX, 9 pages, uses aas2pp4.sty. Accepted for publication in Ap

Optical and X-ray clusters as tracers of the supercluster-void network. I Superclusters of Abell and X-ray clusters

We study the distribution of X-ray selected clusters of galaxies with respect to superclusters determined by Abell clusters of galaxies and show that the distribution of X-ray clusters follows the supercluster-void network determined by Abell clusters. We find that in this network X-ray clusters are more strongly clustered than other clusters. Poor, non-Abell X-ray clusters follow the supercluster-void network as well: these clusters are embedded in superclusters determined by rich clusters and populate filaments between them. We present a new catalog of superclusters of Abell clusters out to a redshift of z_{lim}=0.13, a catalog of X-ray clusters located in superclusters determined by Abell clusters, and a list of additional superclusters of X-ray clusters.Comment: LaTex (sty files added), 16 pages, 3 ps figures, submitted to Astronomical Journal. Animations of the 3D distribution of superclusters of Abell and X-ray clusters at http://www.aai.ee/~maret/SCLVnet.ht

VisHiC—hierarchical functional enrichment analysis of microarray data

Measuring gene expression levels with microarrays is one of the key technologies of modern genomics. Clustering of microarray data is an important application, as genes with similar expression profiles may be regulated by common pathways and involved in related functions. Gene Ontology (GO) analysis and visualization allows researchers to study the biological context of discovered clusters and characterize genes with previously unknown functions. We present VisHiC (Visualization of Hierarchical Clustering), a web server for clustering and compact visualization of gene expression data combined with automated function enrichment analysis. The main output of the analysis is a dendrogram and visual heatmap of the expression matrix that highlights biologically relevant clusters based on enriched GO terms, pathways and regulatory motifs. Clusters with most significant enrichments are contracted in the final visualization, while less relevant parts are hidden altogether. Such a dense representation of microarray data gives a quick global overview of thousands of transcripts in many conditions and provides a good starting point for further analysis. VisHiC is freely available at http://biit.cs.ut.ee/vishic

Oscillations in Quantum Entanglement During Rescattering

We study the time evolution of quantum entanglement between an electron and its parent ion during the rescattering due to a strong few-cycle laser pulse. Based on a simple one-dimensional model, we compute the Neumann entropy during the process for several values of the carrier-envelope phase. The local maxima of the oscillations in the Neumann entropy coincide with the zero crossings of the electric field of the laser pulse. We employ the Wigner function to qualitatively explain the quantum dynamics of rescattering in the phase space.Comment: 2 page