84 research outputs found
United classification of cosmic gamma-ray bursts and their counterparts
United classification of gamma-ray bursts and their counterparts is
established on the basis of measured characteristics: photon energy E and
emission duration T. The founded interrelation between the mentioned
characteristics of events consists in that, as the energy increases, the
duration decreases (and vice versa). The given interrelation reflects the
nature of the phenomenon and forms the E-T diagram, which represents a natural
classification of all observed events in the energy range from 10E9 to 10E-6 eV
and in the corresponding interval of durations from about 10E-2 up to 10E8 s.
The proposed classification results in the consequences, which are principal
for the theory and practical study of the phenomenon.Comment: Keywords Gamma rays: burst
Sinonasal Squamous Cell Carcinoma Survival Outcomes Following Induction Chemotherapy vs Standard of Care Therapy
Objective To compare oncologic outcomes in sinonasal squamous cell carcinoma (SNSCC) treated with standard of care (SOC) definitive therapy, consisting of surgery or chemoradiotherapy, vs induction therapy followed by definitive therapy. Study Design Retrospective review.SettingAcademic tertiary care hospital. Methods The medical records of patients with biopsy-proven SNSCC treated between 2000 and 2020 were reviewed for demographics, tumor characteristics, staging, treatment details, and oncologic outcomes. Patients were matched 1-to-1 by age, sex, and cancer stage according to treatment received. Time-to-event analyses were conducted. Results The analysis included 26 patients with locally advanced SNSCC who received either induction therapy (n = 13) or SOC (n = 13). Baseline demographics, Charlson Comorbidity Index, and median follow-up time were well balanced. Weekly cetuximab, carboplatin, and paclitaxel were the most common induction regimen utilized. Tolerance and safety to induction were excellent. Objective responses were observed in 11 of 13 patients receiving induction. No difference in disease-free survival was found between the induction and SOC groups at 1 or 3 years. However, when compared with SOC, induction therapy resulted in significant improvement in overall survival at 2 years (100% vs 65.3%, P = .043) and 3 years (100% vs 48.4%, P = .016) following completion of definitive therapy. Two patients in the SOC group developed metastatic disease, as compared with none in the induction group. Conclusions Induction therapy was safe and effective. When compared with SOC, induction therapy improved 3-year overall survival
Statistical properties of the Burgers equation with Brownian initial velocity
We study the one-dimensional Burgers equation in the inviscid limit for
Brownian initial velocity (i.e. the initial velocity is a two-sided Brownian
motion that starts from the origin x=0). We obtain the one-point distribution
of the velocity field in closed analytical form. In the limit where we are far
from the origin, we also obtain the two-point and higher-order distributions.
We show how they factorize and recover the statistical invariance through
translations for the distributions of velocity increments and Lagrangian
increments. We also derive the velocity structure functions and we recover the
bifractality of the inverse Lagrangian map. Then, for the case where the
initial density is uniform, we obtain the distribution of the density field and
its -point correlations. In the same limit, we derive the point
distributions of the Lagrangian displacement field and the properties of
shocks. We note that both the stable-clustering ansatz and the Press-Schechter
mass function, that are widely used in the cosmological context, happen to be
exact for this one-dimensional version of the adhesion model.Comment: 42 pages, published in J. Stat. Phy
The scientific potential of space-based gravitational wave detectors
The millihertz gravitational wave band can only be accessed with a
space-based interferometer, but it is one of the richest in potential sources.
Observations in this band have amazing scientific potential. The mergers
between massive black holes with mass in the range 10 thousand to 10 million
solar masses, which are expected to occur following the mergers of their host
galaxies, produce strong millihertz gravitational radiation. Observations of
these systems will trace the hierarchical assembly of structure in the Universe
in a mass range that is very difficult to probe electromagnetically. Stellar
mass compact objects falling into such black holes in the centres of galaxies
generate detectable gravitational radiation for several years prior to the
final plunge and merger with the central black hole. Measurements of these
systems offer an unprecedented opportunity to probe the predictions of general
relativity in the strong-field and dynamical regime. Millihertz gravitational
waves are also generated by millions of ultra-compact binaries in the Milky
Way, providing a new way to probe galactic stellar populations. ESA has
recognised this great scientific potential by selecting The Gravitational
Universe as its theme for the L3 large satellite mission, scheduled for launch
in ~2034. In this article we will review the likely sources for millihertz
gravitational wave detectors and describe the wide applications that
observations of these sources could have for astrophysics, cosmology and
fundamental physics.Comment: 18 pages, 2 figures, contribution to Gravitational Wave Astrophysics,
the proceedings of the 2014 Sant Cugat Forum on Astrophysics; v2 includes one
additional referenc
Separate and combined effects of advanced age and obesity on mammary adipose inflammation, immunosuppression and tumor progression in mouse models of triple negative breast cancer
Introduction: Advanced age and obesity are independent risk and progression factors for triple negative breast cancer (TNBC), which presents significant public health concerns for the aging population and its increasing burden of obesity. Due to parallels between advanced age- and obesityrelated biology, particularly adipose inflammation, we hypothesized that advanced age and obesity each accelerate mammary tumor growth through convergent, and likely interactive, mechanisms. Methods: To test this hypothesis, we orthotopically transplanted murine syngeneic TNBC cells into the mammary glands of young normoweight control (7 months), young diet-induced obese (DIO), aged normoweight control (17 months), and aged DIO female C57BL/6J mice. Results: Here we report accelerated tumor growth in aged control and young DIO mice, compared with young controls. Transcriptional analyses revealed, with a few exceptions, overlapping patterns of mammary tumor inflammation and tumor immunosuppression in aged control mice and young DIO mice, relative to young controls. Moreover, aged control and young DIO tumors, compared with young controls, had reduced abundance ofcytotoxic CD8 T cells. Finally, DIO in advanced age exacerbated mammary tumor growth, inflammation and tumor immunosuppression. Discussion: These findings demonstrate commonalities in the mechanisms driving TNBC in aged and obese mice, relative to young normoweight controls. Moreover, we found that advanced age and DIO interact to accelerate mammary tumor progression. Given the US population is getting older and more obese, age- and obesity-related biological differences will need to be considered when developing mechanism-based strategies for preventing or controlling breast cancer
Separating the Early Universe from the Late Universe: cosmological parameter estimation beyond the black box
We present a method for measuring the cosmic matter budget without
assumptions about speculative Early Universe physics, and for measuring the
primordial power spectrum P*(k) non-parametrically, either by combining CMB and
LSS information or by using CMB polarization. Our method complements currently
fashionable ``black box'' cosmological parameter analysis, constraining
cosmological models in a more physically intuitive fashion by mapping
measurements of CMB, weak lensing and cluster abundance into k-space, where
they can be directly compared with each other and with galaxy and Lyman alpha
forest clustering. Including the new CBI results, we find that CMB measurements
of P(k) overlap with those from 2dF galaxy clustering by over an order of
magnitude in scale, and even overlap with weak lensing measurements. We
describe how our approach can be used to raise the ambition level beyond
cosmological parameter fitting as data improves, testing rather than assuming
the underlying physics.Comment: Replaced to match accepted PRD version. Refs added. Combined CMB data
and window functions at http://www.hep.upenn.edu/~max/pwindows.html or from
[email protected]. 18 figs, 19 journal page
Cosmology with clusters of galaxies
In this Chapter I review the role that galaxy clusters play as tools to
constrain cosmological parameters. I will concentrate mostly on the application
of the mass function of galaxy clusters, while other methods, such as that
based on the baryon fraction, are covered by other Chapters of the book. Since
most of the cosmological applications of galaxy clusters rely on precise
measurements of their masses, a substantial part of my Lectures concentrates on
the different methods that have been applied so far to weight galaxy clusters.
I provide in Section 2 a short introduction to the basics of cosmic structure
formation. In Section 3 I describe the Press--Schechter (PS) formalism to
derive the cosmological mass function, then discussing extensions of the PS
approach and the most recent calibrations from N--body simulations. In Section
4 I review the methods to build samples of galaxy clusters at different
wavelengths. Section 5 is devoted to the discussion of different methods to
derive cluster masses. In Section 6 I describe the cosmological constraints,
which have been obtained so far by tracing the cluster mass function with a
variety of methods. Finally, I describe in Section 7 the future perspectives
for cosmology with galaxy clusters and the challenges for clusters to keep
playing an important role in the era of precision cosmology.Comment: 49 pages, 19 figures, Lectures for 2005 Guillermo Haro Summer School
on Clusters, to appear in "Lecture notes in Physics" (Springer
Global impact of COVID-19 on stroke care and IV thrombolysis
Objective To measure the global impact of COVID-19 pandemic on volumes of IV thrombolysis (IVT), IVT transfers, and stroke hospitalizations over 4 months at the height of the pandemic (March 1 to June 30, 2020) compared with 2 control 4-month periods. Methods We conducted a cross-sectional, observational, retrospective study across 6 continents, 70 countries, and 457 stroke centers. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases. Results There were 91,373 stroke admissions in the 4 months immediately before compared to 80,894 admissions during the pandemic months, representing an 11.5% (95% confidence interval [CI] -11.7 to -11.3, p < 0.0001) decline. There were 13,334 IVT therapies in the 4 months preceding compared to 11,570 procedures during the pandemic, representing a 13.2% (95% CI -13.8 to -12.7, p < 0.0001) drop. Interfacility IVT transfers decreased from 1,337 to 1,178, or an 11.9% decrease (95% CI -13.7 to -10.3, p = 0.001). Recovery of stroke hospitalization volume (9.5%, 95% CI 9.2-9.8, p < 0.0001) was noted over the 2 later (May, June) vs the 2 earlier (March, April) pandemic months. There was a 1.48% stroke rate across 119,967 COVID-19 hospitalizations. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was noted in 3.3% (1,722/52,026) of all stroke admissions. Conclusions The COVID-19 pandemic was associated with a global decline in the volume of stroke hospitalizations, IVT, and interfacility IVT transfers. Primary stroke centers and centers with higher COVID-19 inpatient volumes experienced steeper declines. Recovery of stroke hospitalization was noted in the later pandemic months.Paroxysmal Cerebral Disorder
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