349 research outputs found
Transient jets in the symbiotic prototype Z Andromedae
We present development of the collimated bipolar jets from the symbiotic
prototype Z And that appeared and disappeared during its 2006 outburst. In 2006
July Z And reached its historical maximum at U ~ 8.0. During this period, rapid
photometric variations with Dm ~ 0.06 mag on the timescale of hours developed.
Simultaneously, high-velocity satellite components appeared on both sides of
the H-alpha and H-beta emission line profiles. They were launched
asymmetrically with the red/blue velocity ratio of 1.2 - 1.3. From about
mid-August they became symmetric. Their spectral properties indicated ejection
of bipolar jets collimated within an average opening angle of 6.1 degrees. We
estimated average outflow rate via jets to dM(jet)/dt ~
2xE10-6(R(jet)/1AU)**(1/2) M(Sun)/year, during their August - September
maximum, which corresponds to the emitting mass in jets, M(jet, emitting) ~
6xE-10(Rjet)/1AU)^{3/2} M(Sun). During their lifetime, the jets released the
total mass of M(jet, total) approx 7.4x1E-7 M(Sun). Evolution in the rapid
photometric variability and asymmetric ejection of jets around the optical
maximum can be explained by a disruption of the inner parts of the disk caused
by radiation-induced warping of the disk.Comment: 31 pages, 9 figures, 2 tables, accepted for Ap
Postharvest quality and health of kiwifruit ‘Hayward’ affected by Pseudomonas syringae pv. actinidiae
High-Resolution Spectroscopy in Tr37: Gas Accretion Evolution in Evolved Dusty Disks
Using the Hectochelle multifiber spectrograph, we have obtained
high-resolution (R~34,000) spectra in the Halpha region for a large number of
stars in the 4 Myr-old cluster Tr 37, containing 146 previously known members
and 26 newly identified ones. We present the Halpha line profiles of all
members, compare them to our IR observations of dusty disks (2MASS/JHK + IRAC +
MIPS 24 micron), use the radial velocities as a membership criterion, and
calculate the rotational velocities. We find a good correlation between the
accretion-broadened profiles and the presence of protoplanetary disks, noting
that a small fraction of the accreting stars presents broad profiles with
Halpha equivalent widths smaller than the canonical limit separating CTTS and
WTTS. The number of strong accretors appears to be lower than in younger
regions, and a large number of CTTS have very small accretion rates
(dM/dt<10^{-9} Msun/yr). Taking into account that the spectral energy
distributions are consistent with dust evolution (grain growth/settling) in the
innermost disk, this suggests a parallel evolution of the dusty and gaseous
components. We also observe that about half of the "transition objects" (stars
with no IR excesses at wavelengths shorter than ~6 micron) do not show any
signs of active accretion, whereas the other half is accreting with accretion
rates <10^{-9} Msun/yr. These zero or very low accretion rates reveal important
gas evolution and/or gas depletion in the innermost disk, which could be
related to grain growth up to planetesimal or even planet sizes. Finally, we
examine the rotational velocities of accreting and non accreting stars, finding
no significant differences that could indicate disk locking at these ages.Comment: 51 pages, 13 (reduced resolution) figures, 2 tables. AJ in pres
Environmental factors and agronomic practices associated with Savi’s pine vole abundance in Italian apple orchards
Identification of structural protein–protein interactions of herpes simplex virus type 1
AbstractIn this study we have defined protein–protein interactions between the structural proteins of herpes simplex virus type 1 (HSV-1) using a LexA yeast two-hybrid system. The majority of the capsid, tegument and envelope proteins of HSV-1 were screened in a matrix approach. A total of 40 binary interactions were detected including 9 out of 10 previously identified tegument–tegument interactions (Vittone, V., Diefenbach, E., Triffett, D., Douglas, M.W., Cunningham, A.L., and Diefenbach, R.J., 2005. Determination of interactions between tegument proteins of herpes simplex virus type 1. J. Virol. 79, 9566–9571). A total of 12 interactions involving the capsid protein pUL35 (VP26) and 11 interactions involving the tegument protein pUL46 (VP11/12) were identified. The most significant novel interactions detected in this study, which are likely to play a role in viral assembly, include pUL35–pUL37 (capsid–tegument), pUL46–pUL37 (tegument–tegument) and pUL49 (VP22)–pUS9 (tegument–envelope). This information will provide further insights into the pathways of HSV-1 assembly and the identified interactions are potential targets for new antiviral drugs
Electric force microscopy characterization of buried graphitic channels microfabricated by MeV ion beam implantation
Intrinsic Lipschitz graphs in Heisenberg groups and continuous solutions of a balance equation
In this paper we provide a characterization of intrinsic Lipschitz graphs in
the sub-Riemannian Heisenberg groups in terms of their distributional
gradients. Moreover, we prove the equivalence of different notions of
continuous weak solutions to the equation \phi_y+ [\phi^{2}/2]_t=w, where w is
a bounded function depending on \phi
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