The detailed nature of type Ia supernovae (SNe Ia) remains uncertain, and as survey statistics increase, the question of astrophysical systematic uncertainties arises, notably that of the evolution ...of SN Ia populations. We study the dependence on redshift of the SN Ia
SALT2.4
light-curve stretch, which is a purely intrinsic SN property, to probe its potential redshift drift. The SN stretch has been shown to be strongly correlated with the SN environment, notably with stellar age tracers. We modeled the underlying stretch distribution as a function of redshift, using the evolution of the fraction of young and old SNe Ia as predicted using the SNfactory dataset, and assuming a constant underlying stretch distribution for each age population consisting of Gaussian mixtures. We tested our prediction against published samples that were cut to have marginal magnitude selection effects, so that any observed change is indeed astrophysical and not observational in origin. In this first study, there are indications that the underlying SN Ia stretch distribution evolves as a function of redshift, and that the age drifting model is a better description of the data than any time-constant model, including the sample-based asymmetric distributions that are often used to correct Malmquist bias at a significance higher than 5
σ
. The favored underlying stretch model is a bimodal one, composed of a high-stretch mode shared by both young and old environments, and a low-stretch mode that is exclusive to old environments. The precise effect of the redshift evolution of the intrinsic properties of a SN Ia population on cosmology remains to be studied. The astrophysical drift of the SN stretch distribution does affect current Malmquist bias corrections, however, and thereby the distances that are derived based on SN that are affected by observational selection effects. We highlight that this bias will increase with surveys covering increasingly larger redshift ranges, which is particularly important for the Large Synoptic Survey Telescope.
Abstract
A hierarchical Bayesian model is applied to the Cosmicflows-3 catalogue of galaxy distances in order to derive the peculiar velocity field and distribution of matter within z ∼ 0.054. The ...model assumes the ΛCDM model within the linear regime and includes the fit of the galaxy distances together with the underlying density field. By forward modelling the data, the method is able to mitigate biases inherent to peculiar velocity analyses, such as the Homogeneous Malmquist bias or the lognormal distribution of peculiar velocities. The statistical uncertainty on the recovered velocity field is about 150 km s−1 depending on the location, and we study systematics coming from the selection function and calibration of distance indicators. The resulting velocity field and related density fields recover the cosmography of the Local Universe which is presented in an unprecedented volume of our Universe 10 times larger than previously reached. This methodology opens the doors to reconstruction of initial conditions for larger and more accurate constrained cosmological simulations. This work is also preparatory to larger peculiar velocity data sets coming from Wallaby, TAIPAN, or LSST.
Type Ia Supernovae (SNe Ia) are standardizable candles that allow us to measure the recent expansion rate of the Universe. Due to uncertainties in progenitor physics, potential astrophysical ...dependencies may bias cosmological measurements if not properly accounted for. The dependency of the intrinsic luminosity of SNe Ia with their host-galaxy environment is often used to standardize SNe Ia luminosity and is commonly parameterized as a step function. This functional form implicitly assumes two-populations of SNe Ia. In the literature, multiple environmental indicators have been considered, finding different, sometimes incompatible, step function amplitudes. We compare these indicators in the context of a two-populations model, based on their ability to distinguish the two populations. We show that local H
α
-based specific star formation rate (lsSFR) and global stellar mass are better tracers than, for instance, host galaxy morphology. We show that tracer accuracy can explain the discrepancy between the observed SNe Ia step amplitudes found in the literature. Using lsSFR or global mass to identify the two populations can explain all other observations, though lsSFR is favoured. As lsSFR is strongly connected to age, our results favour a prompt and delayed population model. In any case, there exists two populations that differ in standardized magnitude by at least 0.121 ± 0.010 mag.
Muscle traction and bone metabolism are functionally linked and co‐regulated by a series of factors. Although a role for steroid hormones was hypothesized, a clear definition of the bone–muscle ...interconnection still lacks. To investigate this relationship, we studied bone metabolism, muscle activity, and salivary steroid hormones profile in relation with the physical effort across a cycling stage race, a model of effort in absence of load. Nine pro‐cyclists were recruited; body weight and power output/energy expenditure were recorded. Diet was kept constant. Saliva was collected at days −1, 4, 8, 12, 14, 19, and 23; blood and urine were collected at days −1, 12, and 23. Salivary steroid hormones cortisol, dehydroepiandrosterone (DHEA), testosterone, and estradiol, serum lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and creatine kinase (CK) activities, plasma sclerostin, and urinary calcium and phosphorous were measured. Cortisol remained constant, testosterone decreased at day 4, and estradiol and DHEA firstly increased and then returned to basal levels. Hormone concentrations were not correlated with plasma volume shifts. LDH, CK, AST, sclerostin, and urinary calcium and phosphorous increased. DHEA and estradiol correlated with the physical effort and the bone‐muscular markers. A relationship between muscle activity, in absence of load, and bone resorption emerged under a putative regulation by DHEA and estradiol.
Background
Cystic dystrophy of heterotopic pancreas, groove pancreatitis, pancreatic hamartoma of the duodenum, paraduodenal wall cyst, and myoadenomatosis are all terms grouped together, from a ...pathological viewpoint, as definitions of paraduodenal pancreatitis (PP). The objective of the present study was to investigate the clinical characteristics, therapeutic strategies, and results in 58 patients undergoing pancreatic resection for PP.
Methods
From January 1990 to December 2006 data were prospectively collected on 58 patients who were diagnosed with PP who then underwent pancreaticoduodenectomy.
Results
In this patient cohort the median age was 44.7 years; only 4 patients were women, and only 3 had non-drinker and/or non smoker habits. The overall morbidity was 18.9%, and the median hospitalization was 11 days. There were no postoperative deaths. In a median follow-up of 96.3 months, all patients noted a decrease in the pain associated with PP; 35 patients (76%) had complete disappearance of pain, whereas occasional relapsing pain occurred in the remaining 11 (24%).
Conclusions
Patients with PP have clinical characteristics similar to those of chronic pancreatitis. The diagnostic imaging modalities of choice are ultrasonographic endoscopy and magnetic resonance cholangiopancreaticography. Based on our surgical experience, pancreaticoduodenectomy seems to be a reasonable choice of treatment in patients with PP.
•LDE-PTX at 175 mg/m2/3wk dose was devoid of toxicity at > 3rd line treatment.•Among 18 LDE-PTX treated patients, 9 had PFS > 6 months and 2 had PFS > 1 yr.•LDE-PTX diminished bone pain and improved ...quality of life in all treated patients.
Patients with heavily pretreated, late-stage cancer and bone metastasis are usually poor candidates for further chemotherapy. Previously, we showed that association to lipid nanoparticles (LDE) drastically decreases the toxicity of anti-cancer drugs. Here, we tested the hypothesis that paclitaxel (PTX) carried in LDE could benefit end-of-life patients with painful bone metastases that had been previously treated with conventional PTX. Methods: Eighteen consecutive patients with late-stage cancer, 8 with breast, 5 with prostate and 5 with lung carcinoma, aged 59±9 years, were included in this study. All were receiving opioid medication. LDE-PTX was administered at 175 mg/m 2 every 3 weeks until disease progression. Clinical imaging examinations and serum biochemistry determinations were performed to monitor disease progression. Intensity of bone pain, use of opioid medications and occurrence of pathological bone fractures were also evaluated. Results: In total, 104 chemotherapy cycles were performed and none of the patients showed clinical and laboratorial toxicities or pathological bone fractures. In all patients, pain was reduced so as to allow substitution of non-opioid for opioid medication. Median progression-free survival (PFS) was four months (95% CI 2.4-5.5), but in five patients PFS was longer than 6 months. Conclusions: Absence of observable clinical and laboratorial toxicities from LDE-PTX treatment, improvement of bone pain and the possible effect on PFS in some patients, despite previous use of conventional PTX, suggest that LDEPTX merits further clinical investigation.
Purpose
In animal experiments paclitaxel oleate associated with a cholesterol-rich nanoemulsion concentrated in the neoplastic tissues and showed reduced toxicity and increased antitumor activity ...compared with paclitaxel-Cremophor EL. Here, a clinical study was performed in breast cancer patients to evaluate the tumoral uptake, pharmacokinetics and toxicity of paclitaxel associated to nanoemulsions.
Methods
Twenty-four hours before mastectomy
3
H-paclitaxel oleate associated with
14
C-cholesteryl oleate-nanoemulsion or
3
H-paclitaxel in Cremophor EL were injected into five patients for collection of blood samples and fragments of tumor and normal breast tissue. A pilot clinical study of paclitaxel-nanoemulsion administered at 3-week intervals was performed in four breast cancer patients with refractory advanced disease at 175 and 220 mg/m
2
dose levels.
Results
T
1/2
of paclitaxel oleate associated to the nanoemulsion was greater than that of paclitaxel (
t
1/2
= 15.4 ± 4.7 and 3.5 ± 0.80 h). Uptake of the
14
C-cholesteryl ester nanoemulsion and
3
H-paclitaxel oleate by breast malignant tissue was threefold greater than the normal breast tissue and toxicity was minimal at the two dose levels.
Conclusions
Our results suggest that the paclitaxel-nanoemulsion preparation can be advantageous for use in the treatment of breast cancer because the pharmacokinetic parameters are improved, the drug is concentrated in the neoplastic tissue and the toxicity of paclitaxel is reduced.
Abstract To identify the impact of multiple symptoms and their co-occurrence on health-related quality of life (HRQOL) dimensions and performance status (PS), 115 outpatients with cancer, who were ...not receiving active cancer treatment and were recruited from a university hospital in Sao Paulo, Brazil completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30, the Beck Depression Inventory, and the Brief Pain Inventory. Karnofsky Performance Status scores also were completed. Application of TwoStep Cluster analysis resulted in two distinct patient subgroups based on 113 patient experiences with pain, depression, fatigue, insomnia, constipation, lack of appetite, dyspnea, nausea, vomiting, and diarrhea. One group had multiple and severe symptom subgroup and another had less symptoms and with lower severity. Multiple and severe symptoms had worse PS, role functioning, and physical, emotional, cognitive, social, and overall HRQOL. Multiple and severe symptom subgroup was also six times as likely as lower severity to have poor role functioning; five times more likely to have poor emotional; four times more likely to have poor PS, physical, and overall HRQOL; and three times as likely to have poor cognitive and social HRQOL, independent of gender, age, level of education, and economic condition. Classification and Regression Tree analyses were undertaken to identify which co-occurring symptoms would best determine reduction in HRQOL and PS. Pain and fatigue were identified as indicators of reduction on physical HRQOL and PS. Fatigue and insomnia were associated with reduction in cognitive; depression and pain in social; and fatigue and constipation in role functioning. Only depression was associated with reduction in overall HRQOL. These data demonstrate that there is a synergic effect among distinct cancer symptoms that result in reduction in HRQOL dimensions and PS.
Calcium and phosphate are essential for cell functions, and their serum concentrations result from the balance between intestinal absorption, bony storage, and urinary excretion. Fibroblast growth ...factor 23 (FGF23), expressed by osteocytes and osteoblasts, acts in the kidney, leading to hypophosphatemia and low 1,25‐dihydroxycholecalciferol synthesis, but suppresses parathyroid function. The aim of this study was to explore the effects of a high‐energy demanding cycling race on this bone–kidney–parathyroid axis. We studied nine cyclists during the 2011 Giro d'Italia stage race. Pre‐analytical and analytical phases followed academic and anti‐doping recommendations. Serum parathyroid hormone (PTH), 25(OH)D, total calcium, inorganic phosphorus, and plasma FGF23 were measured on days −1, 12, and 22 and corrected for changes in plasma volume. Dietary calcium and phosphorus, anthropometric parameters (height, weight, and body mass index) and indexes of metabolic effort (net energy expenditure, power output) were recorded. Dietary calcium and phosphorus intakes were kept at the same levels throughout the race. Twenty‐five (OH)D, PTH, and calcium concentrations remained stable. FGF23 increased 50% with a positive correlation with the indexes of metabolic effort and, consequently, phosphorous decreased, although only in the first half. The strong metabolic effort acts on the bone–kidney–parathyroid system, and the rise in FGF23 plasma concentration might be aimed at maintaining calcium and phosphorus homeostasis.
PDF
