Abstract
A large fraction of gamma-ray burst (GRB) lightcurves (LCs) show X-ray plateaus. We analyze all GRBs with known redshifts presenting plateaus observed by The Neil Gehrels Swift Observatory ...from its launch until 2019 August. The fundamental plane relation between the rest-frame time and X-ray luminosity at the end of the plateau emission and the peak prompt luminosity holds for all the GRB classes when selection biases and cosmological evolutions are applied. We have discovered two important findings: (1) a new class of long GRBs with good data coverage: the platinum sample; and (2) the platinum, the SNe-LGRB, and the KN-SGRB samples, yield the smallest intrinsic scatter with
σ
platinum
,
GRB−SNe
= 0.22 ± 0.10 and
σ
KN−SGRB
= 0.24 ± 0.12. The SNe-LGRBs are composed of GRBs associated spectroscopically with the SNe Ib,c, the KN-SGRBs are composed by eight GRBs associated with kilonovae or where there could have been such an association. The highest correlation coefficients are yielded for the SN-LGRB-ABC sample, which includes GRBs spectroscopically associated with SNe Ib/c or with a clear optical bump in the LC resembling the SNe Ib/c, (
), the SN-LGRBs (
), and the KN-SGRBs (
) when the redshift evolution is considered. These category planes are reliable candidates to use as cosmological tools. Furthermore, the distance from the gold fundamental plane is a crucial discriminant among classes. In fact, we find that the distributions of the distances of the SNe-LGRB, SNe-LGRB-ABC, KN-SGRB, and SGRB samples from the gold fundamental plane are statistically different from the distribution of the gold GRBs’ distances from the gold fundamental plane with and without considering evolution cases.
Abstract
Currently, the Λ cold dark matter model, which relies on the existence of cold dark matter and a cosmological constant Λ, best describes the universe. However, we lack information in the ...high-redshift (
z
) region between Type Ia supernovae (SNe Ia; up to
z
= 2.26) and the cosmic microwave background (
z
= 1100), an interval crucial to test cosmological models and their possible evolution. We have defined a sample of 983 quasars up to
z
= 7.54 with a reduced intrinsic dispersion
δ
= 0.007, which determines the matter density parameter Ω
M
with the same precision of SNe Ia. Although previous analysis have used quasars as cosmological tools, this is the first time that high-redshift sources, in this case quasars, as standalone cosmological probes yield such tight constraints on Ω
M
. Our results show the importance of correcting cosmological relationships for selection biases and redshift evolution and how the choice of a golden sample reduces considerably the intrinsic scatter. This proves the reliability of quasars as standard cosmological candles.
ABSTRACT
Cosmological models and their corresponding parameters are widely debated because of the current discrepancy between the results of the Hubble constant, H0, obtained by SNe Ia, and the ...Planck data from the cosmic microwave background radiation. Thus, considering high redshift probes like gamma-ray bursts (GRBs) is a necessary step. However, using GRB correlations between their physical features to infer cosmological parameters is difficult because GRB luminosities span several orders of magnitude. In our work, we use a three-dimensional relation between the peak prompt luminosity, the rest-frame time at the end of the X-ray plateau, and its corresponding luminosity in X-rays: the so-called 3D Dainotti fundamental plane relation. We correct this relation by considering the selection and evolutionary effects with a reliable statistical method, obtaining a lower central value for the intrinsic scatter, σint = 0.18 ± 0.07 (47.1 per cent) compared to previous results, when we adopt a particular set of GRBs with well-defined morphological features, called the platinum sample. We have used the GRB fundamental plane relation alone with both Gaussian and uniform priors on cosmological parameters and in combination with SNe Ia and BAO measurements to infer cosmological parameters like H0, the matter density in the universe (ΩM), and the dark energy parameter w for a wCDM model. Our results are consistent with the parameters given by the Lambda cold dark matter model but with the advantage of using cosmological probes detected up to z = 5, much larger than the one observed for the furthest SNe Ia.
Abstract
Gamma-ray Bursts (GRBs) are the most explosive phenomena in the universe after the big bang. A large fraction of GRB lightcurves (LCs) shows X-ray plateaus. We perform the most comprehensive ...analysis of all GRBs (with known and unknown redshifts) with plateau emission observed by The Neil Gehrels Swift Observatory from its launch until 2019 August. We fit 455 LCs showing a plateau and explore whether these LCs follow closure relations, relations between the temporal and spectral indices of the afterglow, corresponding to two distinct astrophysical environments and cooling regimes within the external forward shock (ES) model, and find that the ES model works for the majority of cases. The most favored environments are a constant-density interstellar or wind medium with slow cooling. We also confirm the existence of the fundamental plane relation between the rest-frame time and luminosity at the end of the plateau emission and the peak prompt luminosity for this enlarged sample, and test this relation on groups corresponding to the astrophysical environments of our known redshift sample. The plane becomes a crucial discriminant corresponding to these environments in terms of the best-fitting parameters and dispersions. Most GRBs for which the closure relations are fulfilled with respect to astrophysical environments have an intrinsic scatter
σ
compatible within 1
σ
of that of the “Gold” GRBs, a subset of long GRBs with relatively flat plateaus. We also find that GRBs satisfying closure relations indicating a fast cooling regime have a lower
σ
than ever previously found in literature.
Summary Recent evidence has linked long-term bisphosphonate use with insufficiency fractures of the femur in postmenopausal women. In this case-control study, we have identified a significant ...association between a unique fracture of the femoral shaft, a transverse fracture in an area of thickened cortices, and long-term bisphosphonate use. Further studies are warranted. Introduction Although clinical trials confirm the anti-fracture efficacy of bisphosphonates over 3-5 years, the long-term effects of bisphosphonate use on bone metabolism are unknown. Femoral insufficiency factures in patients on prolonged treatment have been reported. Methods We performed a retrospective case-control study of postmenopausal women who presented with low-energy femoral fractures from 2000 to 2007. Forty-one subtrochanteric and femoral shaft fracture cases were identified and matched by age, race, and body mass index to one intertrochanteric and femoral neck fracture each. Results Bisphosphonate use was observed in 15 of the 41 subtrochanteric/shaft cases, compared to nine of the 82 intertrochanteric/femoral neck controls (Mantel-Haenszel odds ratio (OR), 4.44 95% confidence interval (CI) 1.77-11.35; P = 0.002). A common X-ray pattern was identified in ten of the 15 subtrochanteric/shaft cases on a bisphosphonate. This X-ray pattern was highly associated with bisphosphonate use (OR, 15.33 95% CI 3.06-76.90; P < 0.001). Duration of bisphosphonate use was longer in subtrochanteric/shaft cases compared to both hip fracture controls groups (P = 0.001). Conclusions We found a significantly greater proportion of patients with subtrochanteric/shaft fractures to be on long-term bisphosphonates than intertrochanteric/femoral neck fractures. Bisphosphonate use was highly associated with a unique X-ray pattern. Further studies are warranted.
In this study, evolution of the genetic structure of the oldest known population of Dothistroma septosporum in Poland was analysed. Dothistroma needle blight was first recorded in Poland in 1990 in a ...5‐year‐old plantation, meaning the population is relatively young in terms of evolution and genetic development. The preservation of DNA extracts from other studies allowed examination of the genetic variation of the pathogen over the span of a decade with the use of highly sensitive microsatellite markers. A number of evolutionary factors were identified that have shaped the genetic structure of this population over time. First, indications of the founder effect and the impact of selection were observed. Secondly, structure analysis provided evidence of the introduction of a new genetic component to the population structure after the pathogen had established. Finally, the impact of the reproductive mode on various components of the Domiarki population was examined, revealing the presence of genetic groups and structure clusters with varying levels of sexual recombination. These results demonstrate how well established and genetically robust a new population of a pathogen may become in just a few decades, given favourable conditions, and how new introductions may facilitate this process.
Summary
Dothistroma needle blight (DNB), one of the most dangerous foliar diseases of pines, is the cause of much economic loss in pine plantations worldwide. The threat to pine‐dominated Polish ...forestry from this disease is therefore very large. However, the impact of DNB has not been high mainly due to the planting of P. sylvestris, a less susceptible native species. Until now, DNB was recorded in Poland only on highly susceptible exotic P. nigra. The current situation concerning the disease in Poland is described in this article. This disease, caused by Dothistroma septosporum, was first recorded in a single location (Domiarki) in southern Poland in 1990. This study reports the occurrence of D. septosporum in 37 new locations, demonstrating that the disease has now spread across the whole country. Pinus nigra remains the predominant host species in Poland. However, three new hosts for this fungus are reported, that is P. sylvestris, P. mugo and P. ponderosa. The ratio of D. septosporum mating types varies significantly between sites, ranging from an equal proportion of each mating type to single mating type populations. For the oldest known Polish population of D. septosporum, the mating type ratio has shifted towards equilibrium over time.
Tendinopathy of the long head of the biceps brachii encompasses a spectrum of pathology ranging from inflammatory tendinitis to degenerative tendinosis. Disorders of the long head of the biceps often ...occur in conjunction with other shoulder pathology. A thorough patient history, physical examination, and radiographic evaluation are necessary for diagnosis. Nonsurgical management, including rest, nonsteroidal anti-inflammatory drugs, physical therapy, and injections, is attempted first in patients with mild disease. Surgical management is indicated for refractory or severe disease. In addition to simple biceps tenotomy, a variety of tenodesis techniques has been described. Open biceps tenodesis has been used historically. However, promising results have recently been reported with arthroscopic tenodesis.
Background The incidence of failed rotator cuff repairs remains high, especially in the setting of massive tears or revision repairs. The purpose of this study was to evaluate patient outcomes and ...repair integrity after augmentation with the repair patch, a poly- l -lactide synthetic polymer. Methods Sixteen consecutive patients with massive or recurrent rotator cuff tears underwent open repair with synthetic poly- l -lactide patch augmentation. Two patients required the patch to bridge defects, and 1 patient retore after a motor vehicle accident and had revision surgery at another institution. The 13 remaining patients were retrospectively evaluated from 1.2 to 1.7 years (average, 1.5 years) after surgery by PENN, American Shoulder and Elbow Surgeons, and Single Assessment Numeric Evaluation scores. Magnetic resonance imaging was used to examine the integrity of the repair at a minimum of 1 year of follow-up. Results The mean age was 57.3 years (42-68 years). Five patients (38%) had an intact rotator cuff at the time of follow-up. The remaining patients (62%) had full-thickness tears. PENN scores significantly improved from a preoperative score of 50.9 to 77.6 ( P < .005). American Shoulder and Elbow Surgeons scores significantly improved from 32.8 to 74.2 ( P = .0001). Single Assessment Numeric Evaluation scores at latest follow-up were 76.2. Conclusion Poly- l -lactide repair patch augmentation of massive and recurrent large to massive rotator cuff tears demonstrates significant improvement in shoulder outcome measures for this difficult population, despite a retear rate of 62%. Further investigation with larger, prospective long-term studies is needed to determine whether this technique provides a true benefit compared with traditional, nonaugmented repair.
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