360 research outputs found
Proportion of time that mangrove tree crab Aratus pisonii spent in sun and shade in three habitats, 2015-2016. Cannizzo et al, (2018) Ecol & Evol.
No full textDataset: A. pisonii: sun-shadeThis dataset includes the proportion of time the mangrove crab, A. pisonii, spent in sun and shade in a mangrove, under a dock, and in a nearby salt marsh for a study of Aratus pisonii behavior. These data are presented in Cannizzo et al, (2018) Ecol & Evol.
For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/741059NSF Division of Ocean Sciences (NSF OCE) OCE-112916
Correction to: RarERN Path: a methodology towards the optimisation of patients’ care pathways in rare and complex diseases developed within the European Reference Networks (Orphanet Journal of Rare Diseases, (2020), 15, 1, (347), 10.1186/s13023-020-01631-1)
No full textFollowing the publication of the original article [1] we were informed that the authors’ given and family names had unfortunately been interchanged. The correct author names are shown here below: Rosaria Talarico, Sara Cannizzo, Valentina Lorenzoni, Diana Marinello, Ilaria Palla, Salvatore Pirri, Simone Ticciati, Leopoldo Trieste, Isotta Triulzi, Enrique Terol, Anna Bucher and Giuseppe Turchetti. The author names have been corrected in the author list of this Correction and updated in the original article
On the occurrence of dwarf nova outbursts in post novae
No full textWe show that irradiation of the accretion disc by the white dwarf limits the occurrence of dwarf nova outbursts in post nova accretion discs. After the nova explosion, the white dwarf has to cool for up to similar to 100 yr - depending on the orbital period (i.e., disc size) and the temperature of the white dwarf after the nova-eruption - before the disc can begin producing dwarf nova outbursts. During this time the inner disc is maintained in a hot, ionised state. Using these calculations, we interpret the long-term photometric variability of the post nova V446 Her (Nova Her 1960) which shows today regular dwarf nova outbursts. As the white dwarf in V446 Her continues to cool over the next similar to 10-20 yr, we predict an increase in the amplitude of outbursts and a decrease of the outburst frequency, because the decreasing irradiation of the accretion disc should allow an increasing annular extent of the accretion disc to participate in limit cycle oscillations
GRB 110328A/Swift J164449.3+573451 : The Tidal Obliteration of a Deeply Plunging Star?
No full textWe examine the tidal disruption event (TDE) scenario to explain Sw 1644+57, a powerful and persistent X-ray source which suddenly became active as GRB 110328A. The precise localization at the center of a z = 0.35 galaxy argues for activity of the central engine as the underlying cause. We look at the suggestion by Bloom et al. of the possibility of a TDE. We argue that Sw 1644+57 cannot be explained by the traditional TDE model in which the periastron distance is close to the tidal disruption radius—three independent lines of argument indicate the orbit must be deeply plunging or else the powerful jet we are observing could not be produced. These arguments stem from (1) comparing the early X-ray light curve to the expected theoretical fallback rate, (2) looking at the time of transition to disk-dominated decay, and (3) considering the TDE rate. Due to the extreme excess in the tidal force above that which would be required minimally to disrupt the star in a deeply plunging orbit at periastron, we suggest this scenario might be referred to more descriptively as a tidal obliteration event (TOE) rather than a TDE
Coherent ultrafast torsional motion and isomerization of a biomimetic dipolar photoswitch
No full textFemtosecond fluorescence up-conversion, UV-Vis and IR transient absorption spectroscopy are used to study the photo-isomerization dynamics of a new type of zwitterionic photoswitch based on a N-alkylated indanylidene pyrroline Schiff base framework (ZW-NAIP). The system is biomimetic, as it mimics the photophysics of retinal, in coupling excited state charge translocation and isomerization. While the fluorescence lifetime is 140 fs, excited state absorption persists over 230 fs in the form of a vibrational wavepacket according to twisting of the isomerizing double bond. After a short "dark'' time window in the UV-visible spectra, which we associate with the passage through a conical intersection (CI), the wavepacket appears on the ground state potential energy surface, as evidenced by the transient mid-IR data. This allows for a precise timing of the photoreaction all the way from the initial Franck-Condon region, through the CI and into both ground state isomers, until incoherent vibrational relaxation dominates the dynamics. The photo-reaction dynamics remarkably follow those observed for retinal in rhodopsin, with the additional benefit that in ZW-NAIP the conformational change reverses the zwitterion dipole moment direction. Last, the pronounced low-frequency coherences make these molecules ideal systems for investigating wavepacket dynamics in the vicinity of a CI and for coherent control experiments
Dual luminescence, interligand decay, and nonradiative electronic relaxation of cyclometalated iridium complexes in solution
No full textFemtosecond broadband photoluminescence studies are presented for Ir(ppy)3 (Ir1), Ir(ppy)2(pic) (Ir2), Ir(ppy)2(bpy)(PF6) (Ir3), Ir(ppz)3 (Ir4), and Ir(ppz)2dipy (Ir5) (where ppy = 2-phenylpyridine, pic = picolinate, bpy = 2,2′-bipyridine, ppz = 1-phenylpyrazole, and dipy = 5-phenyldipyrrinato) in solution. Upon 400-nm excitation of Ir1-Ir3, we observed a prompt population of the lowest MLCT states. The higher states decay on an ultrafast time scale (<100 fs), whereas the lowest 3MLCT state undergoes further vibrational relaxation on a 1-ps time scale. In Ir3, this relaxation is accompanied by an interligand decay from the ppy to the bpy ligand in ∼1.5 ps. For the ppy-containing complexes (Ir1 and Ir2), we found that, at 100 ps, the luminescence is red-shifted with respect to the steady-state emission. This is explained in terms of a time-delayed dual luminescence, which we attribute to a double-well minimum configuration of the lowest emitting triplet states involving the ppy moiety. Ir4 shows a prompt population of the lowest excited state, which then undergoes vibrational relaxation in ∼0.5 ps. Finally, at short times, Ir5 exhibits fluorescence from the lowest 1LC state, which decays in ∼100 fs to the manifold of 3LC states. Overall, this study shows that, although the ultrafast relaxation to the lowest electronic states is quite similar to that of other transition-metal complexes, most of the differences occur at the lowest emissive states, with effects such as time-delayed dual fluorescence, interligand decay, and nonradiative relaxation to the ground or lower-lying metal-centered states. Understanding these effects is crucial for obtaining optimal performances of iridium complexes, calling for further iterations between chemical synthesis and photophysical studies to optimize these complexes
Polarimetry of the transient relativistic jet of GRB 110328/Swift J164449.3+573451
No full textWe present deep infrared (Ks-band) imaging polarimetry and radio (1.4- and 4.8-GHz) polarimetry of the enigmatic transient Swift J164449.3+573451. This source appears to be a short-lived jet phenomenon in a galaxy at redshift z= 0.354, activated by a sudden mass accretion on to the central massive black hole, possibly caused by the tidal disruption of a star. We aim to find evidence for this scenario through linear polarimetry, as linear polarization is a sensitive probe of jet physics, source geometry and the various mechanisms giving rise to the observed radiation. We find a formal Ks-band polarization measurement of Plin= 7.4 ± 3.5 per cent (including systematic errors). Our radio observations show continuing brightening of the source, which allows sensitive searches for linear polarization as a function of time. We find no evidence of linear polarization at radio wavelengths of 1.4 and 4.8 GHz at any epoch, with the most sensitive 3σ limits as deep as 2.1 per cent. These upper limits are in agreement with expectations from scenarios in which the radio emission is produced by the interaction of a relativistic jet with a dense circumsource medium. We further demonstrate how polarization properties can be used to derive properties of the jet in Swift J164449.3+573451, exploiting the similarities between this source and the afterglows of gamma-ray bursts
Cows response to glucose tolerance test (GTT) and periparturient diseases: preliminary study.
No full textThermal readings from under a dock and in a nearby salt marsh (Cannizzo et al, (2018) Ecol & Evol.)
No full textDataset: A. pisonii: dock-marsh thermalThis dataset includes temperature readings from under a dock and in a nearby salt marsh near Fort Pierce, Florida for a study of mangrove tree crabs, Aratus pisonii.
For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/740137NSF Division of Ocean Sciences (NSF OCE) OCE-112916
Ultrafast Isomerization Dynamics of Biomimetic Photoswitches
No full textFemtosecond UV-VIS and mid-IR experiments show that a new class of biomimetic photoswitches photo-isomerizes in less than 300 fs. In close analogy to rhodopsin, the isomerization is driven by ultrafast motion along the stretch and the torsional coordinates. © 2009, Springer-Verlag Berlin Heidelberg
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