205 research outputs found
Arthropods infesting small mammals (Insectivora and Rodentia) near Cedar Point Biological Station in southwestern Nebraska
Cedar Point Biological Station (CPBS) is located in the mixed grass prairie of the central Great Plains, at the transition between the subregions known as the “tall grass” and “short grass” prairies. Adding to the habitat diversity, there are wetlands and riparian habitats associated with the North Platte River and the edge of the Sandhills region of north central Nebraska. This concurrence of habitats supports a diverse small mammal community. The purpose of this paper is to assemble all published information on ectoparasites associated with small mammals (Insectivora, Rodentia) of southwestern Nebraska, and to report the results of an intensive survey carried out by students of the Parasitology field course during two summers at CPBS. In 2012 and 2013, 27 species of mammal-associated arthropods were collected, including five species of sucking lice (Anoplura), a chewing louse (Ischnocera), six species of fleas (Siphonaptera), thirteen species of mesostigmatic mites (Laelapidae, Macronyssidae, Macrochelidae), and two species of metastigmatic ticks (Ixodidae). These specimens were brushed from the pelage of 11 species of small mammals that were captured in a variety of habitats around CPBS. The arthropod list includes 17 new records for the State of Nebraska. This collection is housed in the Harold W. Manter Laboratory of Parasitology (HWML), University of Nebraska State Museum, at the University of Nebraska-Lincoln, and serves as a taxonomic base for our continued efforts to establish a long-term catalog of parasites associated with small mammals in southwestern Nebraska
The molecular landscape and associated clinical experience in infant medulloblastoma: prognostic significance of second-generation subtypes
Aims:
Biomarker‐driven therapies have not been developed for infant medulloblastoma (iMB). We sought to robustly sub‐classify iMB, and proffer strategies for personalized, risk‐adapted therapies.
Methods:
We characterized the iMB molecular landscape, including second‐generation subtyping, and the associated retrospective clinical experience, using large independent discovery/validation cohorts (n = 387).
Results:
iMBGrp3 (42%) and iMBSHH (40%) subgroups predominated. iMBGrp3 harboured second‐generation subtypes II/III/IV. Subtype II strongly associated with large‐cell/anaplastic pathology (LCA; 23%) and MYC amplification (19%), defining a very‐high‐risk group (0% 10yr overall survival (OS)), which progressed rapidly on all therapies; novel approaches are urgently required. Subtype VII (predominant within iMBGrp4) and subtype IV tumours were standard risk (80% OS) using upfront CSI‐based therapies; randomized‐controlled trials of upfront radiation‐sparing and/or second‐line radiotherapy should be considered. Seventy‐five per cent of iMBSHH showed DN/MBEN histopathology in discovery and validation cohorts (P < 0.0001); central pathology review determined diagnosis of histological variants to WHO standards. In multivariable models, non‐DN/MBEN pathology was associated significantly with worse outcomes within iMBSHH. iMBSHH harboured two distinct subtypes (iMBSHH‐I/II). Within the discriminated favourable‐risk iMBSHH DN/MBEN patient group, iMBSHH‐II had significantly better progression‐free survival than iMBSHH‐I, offering opportunities for risk‐adapted stratification of upfront therapies. Both iMBSHH‐I and iMBSHH‐II showed notable rescue rates (56% combined post‐relapse survival), further supporting delay of irradiation. Survival models and risk factors described were reproducible in independent cohorts, strongly supporting their further investigation and development.
Conclusions:
Investigations of large, retrospective cohorts have enabled the comprehensive and robust characterization of molecular heterogeneity within iMB. Novel subtypes are clinically significant and subgroup‐dependent survival models highlight opportunities for biomarker‐directed therapies
SN 2019ewu: A Peculiar Supernova with Early Strong Carbon and Weak Oxygen Features from a New Sample of Young SN Ic Spectra
With the advent of high cadence, all-sky automated surveys, supernovae (SNe)
are now discovered closer than ever to their dates of explosion. However, young
pre-maximum light follow-up spectra of Type Ic supernovae (SNe Ic), probably
arising from the most stripped massive stars, remain rare despite their
importance. In this paper we present a set of 49 optical spectra observed with
the Las Cumbres Observatory through the Global Supernova Project for 6 SNe Ic,
including a total of 17 pre-maximum spectra, of which 8 are observed more than
a week before V-band maximum light. This dataset increases the total number of
publicly available pre-maximum light SN Ic spectra by 25% and we provide
publicly available SNID templates that will significantly aid in the fast
identification of young SNe Ic in the future. We present detailed analysis of
these spectra, including Fe II 5169 velocity measurements, O I 7774 line
strengths, and continuum shapes. We compare our results to published samples of
stripped supernovae in the literature and find one SN in our sample that stands
out. SN 2019ewu has a unique combination of features for a SN Ic: an extremely
blue continuum, high absorption velocities, a P-cygni shaped feature almost 2
weeks before maximum light that TARDIS radiative transfer modeling attributes
to C II rather than H, and weak or non-existent O I 7774 absorption
feature until maximum light.Comment: Submitted to the Astrophysical Journal. 15 pages, 6 figure
Over 500 Days in the Life of the Photosphere of the Type Iax Supernova SN 2014dt
Type Iax supernovae (SN Iax) are the largest known class of peculiar white
dwarf supernovae, distinct from normal Type Ia supernovae (SN Ia). The unique
properties of SN Iax, especially their strong photospheric lines out to
extremely late times, allow us to model their optical spectra and derive
physical parameters for the long-lasting photosphere. We present an extensive
spectral timeseries, including 21 new spectra, of SN Iax 2014dt from +11 to
+562 days after maximum light. We are able to reproduce the entire timeseries
with a self-consistent, nearly unaltered deflagration explosion model from Fink
et al. (2014) using TARDIS, an open-source radiative transfer code (Kerzendorf
& Sim 2014; Kerzendorf et al. 2023). We find that the photospheric velocity of
SN 2014dt slows its evolution between +64 and +148 days, which closely overlaps
the phase when we see SN 2014dt diverge from the normal spectral evolution of
SN Ia (+90 to +150 days). The photospheric velocity at these epochs,
~4001000 km s, may demarcate a boundary within the ejecta below which
the physics of SN Iax and normal SN Ia differ. Our results suggest that SN
2014dt is consistent with a weak deflagration explosion model that leaves
behind a bound remnant and drives an optically thick, quasi-steady-state wind
creating the photospheric lines at late times. The data also suggest that this
wind may weaken at epochs past +450 days, perhaps indicating a radioactive
power source that has decayed away.Comment: Accepted to ApJ, 22 pages, 8 figures, 3 table
Supernova 2018cuf : a type iip supernova with a slow fall from plateau
We present multiband photometry and spectroscopy of SN 2018cuf, a Type IIP ("P"for plateau) supernova (SN) discovered by the Distance Less Than 40 Mpc Survey within 24 hr of explosion. SN 2018cuf appears to be a typical SN IIP, with an absolute V-band magnitude of -16.73 ± 0.32 at maximum and a decline rate of 0.21 ± 0.05 mag/50 days during the plateau phase. The distance of the object was constrained to be 41.8 ± 5.7 Mpc by using the expanding photosphere method. We used spectroscopic and photometric observations from the first year after the explosion to constrain the progenitor of SN 2018cuf using both hydrodynamic light-curve modeling and late-time spectroscopic modeling. The progenitor of SN 2018cuf was most likely a red supergiant of about 14.5 Me that produced 0.04 ± 0.01 Me 56Ni during the explosion. We also found ∼0.07 Me of circumstellar material (CSM) around the progenitor is needed to fit the early light curves, where the CSM may originate from presupernova outbursts. During the plateau phase, high-velocity features at ∼11,000 km s-1 were detected in both the optical and near-infrared spectra, supporting the possibility that the ejecta were interacting with some CSM. A very shallow slope during the postplateau phase was also observed, and it is likely due to a low degree of nickel mixing or the relatively high nickel mass in the SN.Fil: Dong, Yize. University of California at Davis; Estados UnidosFil: Valenti, S.. University of California at Davis; Estados UnidosFil: Bostroem, K. A.. University of California at Davis; Estados UnidosFil: Sand, D. J.. University of Arizona; Estados UnidosFil: Andrews, Jennifer E.. University of Arizona; Estados UnidosFil: Galbany, Lluís. Universidad de Granada; EspañaFil: Jha, Saurabh W.. State University of New Jersey; Estados UnidosFil: Eweis, Youssef. State University of New Jersey; Estados UnidosFil: Kwok, Lindsey. State University of New Jersey; Estados UnidosFil: Hsiao, Eric. Florida State University; Estados UnidosFil: Davis, Scott. Florida State University; Estados UnidosFil: Brown, Peter J.. Texas A&M University; Estados UnidosFil: Kuncarayakti, H.. University of Turku; FinlandiaFil: Maeda, Keiichi. Kyoto University; JapónFil: Rho, Jeonghee. SETI Institute; Estados UnidosFil: Amaro, R. C.. University of Arizona; Estados UnidosFil: Anderson, J. P.. European Southern Observatory Chile; ChileFil: Arcavi, Iair. Universitat Tel Aviv; IsraelFil: Burke, Jamison. University of California; Estados UnidosFil: Dastidar, Raya. Aryabhatta Research Institute of observational sciences; IndiaFil: Folatelli, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Haislip, Joshua. University of North Carolina at Chapel Hill; Estados UnidosFil: Hiramatsu, Daichi. University of California; Estados UnidosFil: Hosseinzadeh, Griffin. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Howell, D. Andrew. University of California; Estados UnidosFil: Jencson, J.. University of Arizona; Estados UnidosFil: Kouprianov, Vladimir. University of North Carolina at Chapel Hill; Estados UnidosFil: Lundquist, M.. University of Arizona; Estados UnidosFil: Lyman, J. D.. University of Warwick; Reino UnidoFil: McCully, Curtis. University of California; Estados Unido
Increased fracture rate in women with breast cancer: a review of the hidden risk
Women with breast cancer, particularly individuals diagnosed at a relatively early age, have an increased incidence of fractures. Fractures can have serious clinical consequences including the need for major surgery, increased morbidity and mortality, increased cost of disease management, and reduced quality of life for patients. The primary cause of the increased fracture risk appears to be an accelerated decrease in bone mineral density (BMD) resulting from the loss of estrogenic signaling that occurs with most treatments for breast cancer, including aromatase inhibitors. However, factors other than BMD levels alone may influence treatment decisions to reduce fracture risk in this setting. Our purpose is to review current evidence for BMD loss and fracture risk during treatment for breast cancer and discuss pharmacologic means to reduce this risk.Journal ArticleResearch Support, Non-U.S. Gov'tReviewSCOPUS: re.jinfo:eu-repo/semantics/publishe
SN 2022crv: IIb, Or Not IIb: That is the Question
We present optical and near-infrared observations of SN~2022crv, a stripped
envelope supernova in NGC~3054, discovered within 12 hrs of explosion by the
Distance Less Than 40 Mpc Survey. We suggest SN~2022crv is a transitional
object on the continuum between SNe Ib and SNe IIb. A high-velocity hydrogen
feature (20,000 -- 16,000 ) was conspicuous in
SN~2022crv at early phases, and then quickly disappeared around maximum light.
By comparing with hydrodynamic modeling, we find that a hydrogen envelope of
\msun{} can reproduce the behaviour of the hydrogen feature
observed in SN~2022crv. The early light curve of SN~2022crv did not show
envelope cooling emission, implying that SN~2022crv had a compact progenitor
with extremely low amount of hydrogen. The analysis of the nebular spectra
shows that SN~2022crv is consistent with the explosion of a He star with a
final mass of 4.5 -- 5.6 \msun{} that has evolved from a 16 -- 22
\msun{} zero-age main sequence star in a binary system with about 1.0 -- 1.7
\msun{} of oxygen finally synthesized in the core. The high metallicity at the
supernova site indicates that the progenitor experienced a strong stellar wind
mass loss. In order to retain a small amount of residual hydrogen at such a
high metallicity, the initial orbital separation of the binary system is likely
larger than 1000~. The near-infrared spectra of SN~2022crv
show a unique absorption feature on the blue side of He I line at
1.005~m. This is the first time that such a feature has been
observed in a Type Ib/IIb, and could be due to \ion{Sr}{2}. Further detailed
modelling on SN~2022crv can shed light on the progenitor and the origin of the
mysterious absorption feature in the near infrared.Comment: 33 pages, 23 figures, submitted to Ap
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