3,530 research outputs found
Endurance of SN 2005ip after a decade: X-rays, radio, and H-alpha like SN 1988Z require long-lived pre-supernova mass loss
SN2005ip was a TypeIIn event notable for its sustained strong interaction
with circumstellar material (CSM), coronal emission lines, and IR excess,
interpreted as shock interaction with the very dense and clumpy wind of an
extreme red supergiant. We present a series of late-time spectra of SN2005ip
and a first radio detection of this SN, plus late-time X-rays, all of which
indicate that its CSM interaction is still strong a decade post-explosion. We
also present and discuss new spectra of geriatric SNe with continued CSM
interaction: SN1988Z, SN1993J, and SN1998S. From 3-10 yr post-explosion,
SN2005ip's H-alpha luminosity and other observed characteristics were nearly
identical to those of the radio-luminous SN1988Z, and much more luminous than
SNe1993J and 1998S. At 10 yr after explosion, SN2005ip showed a drop in
H luminosity, followed by a quick resurgence over several months. We
interpret this variability as ejecta crashing into a dense shell located at
around 0.05 pc from the star, which may be the same shell that caused the IR
echo at earlier epochs. The extreme H-alpha luminosities in SN2005ip and
SN1988Z are still dominated by the forward shock at 10 yr post-explosion,
whereas SN1993J and SN1998S are dominated by the reverse shock at a similar
age. Continuous strong CSM interaction in SNe~2005ip and 1988Z is indicative of
enhanced mass loss for about 1e3 yr before core collapse, longer than Ne, O, or
Si burning phases. Instead, the episodic mass loss must extend back through C
burning and perhaps even part of He burning.Comment: 14 pages, 8 figs. accepted in MNRA
SN2013fs and SN2013fr: Exploring the circumstellar-material diversity in Type II supernovae
We present photometry and spectroscopy of SN2013fs and SN2013fr in the first
100 days post-explosion. Both objects showed transient, relatively narrow
H emission lines characteristic of SNeIIn, but later resembled normal
SNeII-P or SNeII-L, indicative of fleeting interaction with circumstellar
material (CSM). SN2013fs was discovered within 8hr of explosion. Its light
curve exhibits a plateau, with spectra revealing strong CSM interaction at
early times. It is a less luminous version of the transitional SNIIn PTF11iqb,
further demonstrating a continuum of CSM interaction intensity between SNeII-P
and IIn. It requires dense CSM within 6.510~cm of the
progenitor, from a phase of advanced pre-SN mass loss shortly before explosion.
Spectropolarimetry of SN2013fs shows little continuum polarization, but
noticeable line polarization during the plateau phase. SN2013fr morphed from a
SNIIn at early times to a SNII-L. After the first epoch its narrow lines
probably arose from host-galaxy emission, but the bright, narrow H
emission at early times may be intrinsic. As for SN2013fs, this would point to
a short-lived phase of strong CSM interaction if proven to be intrinsic,
suggesting a continuum between SNeIIn and II-L. It is a low-velocity SNII-L,
like SN2009kr but more luminous. SN2013fr also developed an IR excess at later
times, due to warm CSM dust that require a more sustained phase of strong
pre-SN mass loss.Comment: MNRAS accepted. 28 pages, 23 figures, 8 table
Intergenerational social mobility and mid-life status attainment: influences of childhood intelligence, childhood social factors, and education
We examined the influences of childhood social background, childhood cognitive ability, and education on intergenerational social mobility and social status attainment at midlife. The subjects were men born in 1921 and who participated in the Scottish Mental Survey of 1932 and thereafter in the Midspan Collaborative study in Scotland between 1970 and 1973. In logistic regression analyses, childhood cognitive ability and height were associated with upward and downward change from father's social class to participant's social class at mid-life. Education significantly influenced upward social mobility. Number of siblings had no significant effect on social mobility. These effects were also examined after adjusting for the other variables. In structural equation modelling analyses, father's social class and childhood cognitive ability influenced social status attainment at midlife, with education and occupational status in young adulthood as partially mediating factors. It was noteworthy that childhood cognitive ability related more strongly to occupation in midlife than to first occupation. These data add to the relatively few studies that track the process of status attainment in adulthood, they provide information from a new geographical setting, and they contain information from a greater proportion of the lifecourse than do most existing studies
A1C Variability and the Risk of Microvascular Complications in Type 1 Diabetes: Data from the Diabetes Control and Complications Trial
OBJECTIVE—Debate remains as to whether short- or long-term glycemic instability confers a risk of microvascular complications in addition to that predicted by mean glycemia alone. In this study, we analyzed data from the Diabetes Control and Complications Trial (DCCT) to assess the effect of A1C variability on the risk of retinopathy and nephropathy in patients with type 1 diabetes
Quantifying trends in disease impact to produce a consistent and reproducible definition of an emerging infectious disease.
The proper allocation of public health resources for research and control requires quantification of both a disease's current burden and the trend in its impact. Infectious diseases that have been labeled as "emerging infectious diseases" (EIDs) have received heightened scientific and public attention and resources. However, the label 'emerging' is rarely backed by quantitative analysis and is often used subjectively. This can lead to over-allocation of resources to diseases that are incorrectly labelled "emerging," and insufficient allocation of resources to diseases for which evidence of an increasing or high sustained impact is strong. We suggest a simple quantitative approach, segmented regression, to characterize the trends and emergence of diseases. Segmented regression identifies one or more trends in a time series and determines the most statistically parsimonious split(s) (or joinpoints) in the time series. These joinpoints in the time series indicate time points when a change in trend occurred and may identify periods in which drivers of disease impact change. We illustrate the method by analyzing temporal patterns in incidence data for twelve diseases. This approach provides a way to classify a disease as currently emerging, re-emerging, receding, or stable based on temporal trends, as well as to pinpoint the time when the change in these trends happened. We argue that quantitative approaches to defining emergence based on the trend in impact of a disease can, with appropriate context, be used to prioritize resources for research and control. Implementing this more rigorous definition of an EID will require buy-in and enforcement from scientists, policy makers, peer reviewers and journal editors, but has the potential to improve resource allocation for global health
Immunological characterization of chromogranins A and B and secretogranin II in the bovine pancreatic islet
Antisera against chromogranin A and B and secretogranin II were used for analysing the bovine pancreas by immunoblotting and immunohistochemistry. All three antigens were found in extracts of fetal pancreas by one dimensional immunoblotting. A comparison with the soluble proteins of chromaffin granules revealed that in adrenal medulla and in pancreas antigens which migrated identically in electrophoresis were present. In immunohistochemistry, chromogranin A was found in all pancreatic endocrine cell types with the exception of most pancreatic polypeptide-(PP-) producing cells. For chromogranin B, only a faint immunostaining was obtained. For secretorgranin II, A-and B-cells were faintly positive, whereas the majority of PP-cells exhibited a strong immunostaining for this antigen. These results establish that chromogranins A and B and secretogranin II are present in the endocrine pancreas, but that they exhibit a distinct cellular localization
Nesting biology of the bee Caupolicana yarrowi.
20 pages : illustrations (some color), color maps ; 26 cm.
Appendix: Use of nectar by the desert bee Caupolicana yarrowi (Colletidae) in cell construction / James H. Cane and Jerome G. Rozen, Jr.The first part of this publication, written by a group of participants in Bee Course 2018, results from the discovery of three nests of Caupolicana yarrowi (Cresson, 1875) at the base of the Chiricahua Mountains in southeastern Arizona. The nests are deep with branching laterals that usually connect to large vertical brood cells by an upward turn before curving downward and attaching to the top of the chambers. This loop of the lateral thus seems to serve as a "sink trap," excluding rainwater from reaching open cells during provisioning. Although mature larvae had not yet developed, an egg of C. yarrowi was discovered floating on the provisions allowing an SEM examination of its chorion, the first such study for any egg of the Diphaglossinae. Larval food for this species at this site came from Solanum elaeagnifolium Cav. (Solanaceae). Nests were parasitized by Triepeolus grandis (Friese, 1917) (Epeolini), which previously was known to attack only Ptiloglossa (Diphaglossinae: Caupolicanini). The subterranean nest cells of the desert bee Caupolicana yarrowi (Colletidae), which are enveloped by a casing of hardened soil that easily separates from the surrounding matrix, are discussed in a separate appendix. Chemical analysis revealed the casing to be rich in reducing sugars, indicating that the mother bee had regurgitated floral nectar onto the rough interior walls of the cell cavity before smoothing and waterproofing them. This novel use of nectar in nest construction is compared with that of other bee species that bring water to a nest site to soften soil for excavation
Double-Peaked Balmer Emission Indicating Prompt Accretion Disk Formation in an X-Ray Faint Tidal Disruption Event
We present the multi-wavelength analysis of the tidal disruption event (TDE)
AT~2018hyz (ASASSN-18zj). From follow-up optical spectroscopy, we detect the
first unambiguous case of resolved double-peaked Balmer emission in a TDE. The
distinct line profile can be well-modelled by a low eccentricity
() accretion disk extending out to 100 and a
Gaussian component originating from non-disk clouds, though a bipolar outflow
origin cannot be completely ruled out. Our analysis indicates that in
AT~2018hyz, disk formation took place promptly after the most-bound debris
returned to pericenter, which we estimate to be roughly tens of days before the
first detection. Redistribution of angular momentum and mass transport,
possibly through shocks, must occur on the observed timescale of about a month
to create the large \Ha-emitting disk that comprises 5\% of the
initial stellar mass. With these new insights from AT~2018hyz, we infer that
circularization is efficient in at least some, if not all optically-bright,
X-ray faint TDEs. In these efficiently circularized TDEs, the detection of
double-peaked emission depends on the disk inclination angle and the relative
strength of the disk contribution to the non-disk component, possibly
explaining the diversity seen in the current sample.Comment: 24 pages, 8 figures, 6 tables. Accepted for publication in Ap
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