Combined lensed estimator to probe the post reionization H i power spectrum

In the post-reionization era, the baryons assembled into the protogalaxies and eventually the present population of the galaxies evolved through merger and evolution. In this work, we discuss a possible probe of the statistical distribution and evolution of the H i density in the post reionization era. We introduce an estimator of the H i power spectrum from the post reionization universe by observing it through the strong gravitational lenses by the nearby galaxy cluster. We also analytically calculate the uncertainties associated with the estimates of the post-EoR power spectrum for the discussed estimator. We access the efficacy of this estimator in the context of 19 galaxy clusters for which the lensing potential has been estimated earlier by various authors. We find that by combining the lensed power spectrum through eight of these cluster lenses, it is possible to estimate the post-reionization H i power spectrum at five-sigma significance for angular multipoles <4000 for a uGMRT observation of 16 MHz bandwidth from redshifts of 1.25, 1.5 with a total of 400 hours of observation. With the same setup, for a redshift of 3.0, we need 200 hours of total observation time. The estimator also suppresses the diffused galactic foreground, though, the latter is still a dominant contributor to the overall signal and hence need to be estimated and mitigated. We discuss the merits and demerits of the estimator.

K2 Ultracool Dwarfs Survey – VI. White light superflares observed on an L5 dwarf and flare rates of L dwarfs

ABSTRACT $Kepler\, K2$ long cadence data are used to study white light flares in a sample of 45 L dwarfs. We identified 11 flares on 9 L dwarfs with equivalent durations of (1.3–198) h and total (UV/optical/IR) energies of ≥0.9 × 1032 erg. Two superflares with energies of >1033 erg were detected on an L5 dwarf (VVV BD001): this is the coolest object so far on which flares have been identified. The larger superflare on this L5 dwarf has an energy of 4.6 × 1034 erg and an amplitude of >300 times the photospheric level: so far, this is the largest amplitude flare detected by the Kepler/K2 mission. The next coolest star on which we identified a flare was an L2 dwarf: 2MASS J08585891+1804463. Combining the energies of all the flares which we have identified on 9 L dwarfs with the total observation time which was dedicated by Kepler to all 45 L dwarfs, we construct a composite flare frequency distribution (FFD). The FFD slope is quite shallow (−0.51 ± 0.17), consistent with earlier results reported by Paudel et al. for one particular L0 dwarf, for which the FFD slope was found to be −0.34. Using the composite FFD, we predict that, in early- and mid-L dwarfs, a superflare of energy 1033 erg occurs every 2.4 yr and a superflare of energy 1034 erg occurs every 7.9 yr. Analysis of our L dwarf flares suggests that magnetic fields of ≥0.13–1.3 kG are present on the stellar surface: such fields could suppress Type II radio bursts.

Modelling stochastic signatures in classical pulsators

ABSTRACT We consider the impact of stochastic perturbations on otherwise coherent oscillations of classical pulsators. The resulting dynamics are modelled by a driven damped harmonic oscillator subject to either an external or an internal forcing and white noise velocity perturbations. We characterize the phase and relative amplitude variations using analytical and numerical tools. When the forcing is internal the phase variation displays a random walk behaviour and a red noise power spectrum with a ragged erratic appearance. We determine the dependence of the root mean square phase and relative amplitude variations (σΔφ and σΔA/A, respectively) on the amplitude of the stochastic perturbations, the damping constant η, and the total observation time tobs for this case, under the assumption that the relative amplitude variations remain small, showing that σΔφ increases with $t_{\rm obs}^{1/2}$ becoming much larger than σΔA/A for tobs ≫ η−1. In the case of an external forcing the phase and relative amplitude variations remain of the same order, independent of the observing time. In the case of an internal forcing, we find that σΔφ does not depend on η. Hence, the damping time cannot be inferred from fitting the power of the signal, as done for solar-like pulsators, but the amplitude of the stochastic perturbations may be constrained from the observations. Our results imply that, given sufficient time, the variation of the phase associated with the stochastic perturbations in internally driven classical pulsators will become sufficiently large to be probed observationally.

Recurrence of Cholesteatoma - A Retrospective Study Including 1,006 Patients for More than 33 Years

Introduction Cholesteatomas are benign tumors consisting of skin, and growing inside a retraction pocket in the tympanic membrane. Cholesteatomas can occupy the entirety of the middle ear, and are known for their osteolytic capabilities. Surgery is the only curative treatment for cholesteatomas. Objective To describe the risk of recurrence after first-time surgically-treated middle-ear cholesteatoma (STMEC1) on the island of Funen from 1983 to 2015. Methods Cases of STMEC1 were identified in the Danish National Hospital Register. The medical records were reviewed. Time-to-event analyses were applied. The ears were followed from STMEC1 to a secondary cholesteatoma, emigration, death, or end of follow-up. Results Records from 1,006 patients with STMEC1 were reviewed. A total of 54 patients were submitted to surgery on both ears. The total sample consisted of 1,060 ears with STMEC1; 300 were children's (< 16 years) ears, and 760 were adult's ears. The total observation time was of 12,049 years.The overall estimated proportion with recurrence 5 years after surgery was of 37% in children and of 15% in adults. The older the child was at the first surgery, the risk decreased by 7% per year. In children, canal wall up (CWU) mastoidectomy without obliteration was associated with a hazard ratio for recurrence of 1.9 (95% confidence interval [95%CI]: 1.2–3.0) compared with CWU with obliteration. Conclusion Compared with adults, children were had 2.6 times more risk of recurrence. Procedures performed without mastoidectomy had the lowest risk of recurrence. In children, obliteration was associated with a significantly lower risk of recurrence. However, patients were not randomized regarding the surgical approach; thus, the association between approach and risk of recurrence was likely influenced by confounding factors.

Incidence and severity of prostate cancer (PCa) in 792 hypogonadal men with and without long-term testosterone therapy (TTh): Results from a controlled registry study.

167 Background: There is no evidence that TTh in hypogonadal men increases PCa incidence or severity. A US-Scandinavian group recently found that men receiving TTh had lower risk of aggressive PCa (Loeb S et al., J Clin Oncol 2017; 35:1430-6). Methods: 412 men with testosterone ≤350 ng/dL and symptoms received testosterone undecanoate 1000 mg every 3 months for up to 12 years. 380 hypogonadal men (57-74) opted against TTh. Median follow-up: 9 years. Total observation time covered approximately 6,400 patient-years. Prostate volume (PV) and PSA were measured and digital rectal examination/transrectal ultrasound performed before treatment/observation initiation and then every 3-6 months (T-group) or once or twice per year (CTRL). Biopsies were performed when indicated according to EAU guidelines. Results: In the T-group, 11 men (2.7%) were diagnosed with PCa. In CTRL, 34 (8.9%) were diagnosed with PCa. The incidence per 10,000 years was 33 in the T-group and 108 in CTRL. The mean baseline age of PCa patients was 65.2 years in the T-group and 64.3 in CTRL. All PCa diagnoses in the T-group were made within the first 18 months of treatment initiation. In CTRL, PCa was diagnosed at any time during the observation time. In the T-group, radical prostatectomy was performed in all men. All but 1 patient had a Gleason score (GS) ≤6, and all but 1 a predominant GS of 3. Tumor grade was G2 in all 11 (100%), tumor stage T2a in 7 (64%), T2b in 3 (27%), and T2c in 1 (9%) patient(s). In CTRL, radical prostatectomy was performed in all but 6 patients. GS was > 6 in all 34 patients. 7 men had a GS of 7, 17 a GS of 8, and 10 a GS of 9. 2 men had a predominant Gleason score of 3, 22 had 4, and 10 had 5. Tumor grade was G2 in 6 (17.6%) and G3 in 28 (82.4%) patients, tumor stage T2c in 1 (0.3%), T3a in 3 (8.8%), T3b in 13 (38.2%) and T3c in 17 (50%) patients. In CTRL, biochemical recurrence occurred in 8 (23.5%) patients. These patients received androgen deprivation therapy (ADT). 10 (29.4%) patients died of whom 5 were on ADT. In the T-group, there were no biochemical recurrences or deaths during the observation time. Conclusions: In hypogonadal men, TTh may decrease PCa incidence compared to CTRL. PCa was less severe in the T-group.

Activity profiles and hook-tool use of New Caledonian crows recorded by bird-borne video cameras

New Caledonian crows are renowned for their unusually sophisticated tool behaviour. Despite decades of fieldwork, however, very little is known about how they make and use their foraging tools in the wild, which is largely owing to the difficulties in observing these shy forest birds. To obtain first estimates of activity budgets, as well as close-up observations of tool-assisted foraging, we equipped 19 wild crows with self-developed miniature video cameras, yielding more than 10 h of analysable video footage for 10 subjects. While only four crows used tools during recording sessions, they did so extensively: across all 10 birds, we conservatively estimate that tool-related behaviour occurred in 3% of total observation time, and accounted for 19% of all foraging behaviour. Our video-loggers provided first footage of crows manufacturing, and using, one of their most complex tool types—hooked stick tools—under completely natural foraging conditions. We recorded manufacture from live branches of paperbark ( Melaleuca sp.) and another tree species (thought to be Acacia spirorbis ), and deployment of tools in a range of contexts, including on the forest floor. Taken together, our video recordings reveal an ‘expanded’ foraging niche for hooked stick tools, and highlight more generally how crows routinely switch between tool- and bill-assisted foraging.

The effects of introducing the Amazonian squirrel monkey on the behavior of the northeast marmoset

The squirrel monkey Saimiri sciureus, an endemic primate of the Amazonian Basin, has been introduced in many localities of the Atlantic Forest biome. Introduced exotic species gain a competitive advantage in their new environment because of a lack of natural predators, competitors or diseases. This advantage can result in a reduction in the resources for the endemic species. The aims of this work were to evaluate the level of adaptation, and monitor the forms of interaction and the impact caused by S. sciureus on the behavior of the native species Callithrix jacchus in the Saltinho Biological Reserve, Tamandaré, Pernambuco, Brazil. The behavior was assessed by use of scan sampling method, every 5 min. A total of 382 h (191 h or 2,292 scans per group) of time sampling was performed. Sixteen interactions were recorded. The interaction index was low and represented 2.4% of the total observation time. Interactions were significantly higher during the dry season (58.5%) relative to the rainy season (41.5%). Callithrix jacchus was intolerant to the presence of S. sciureus and the last one was more tolerant during the interactions. In the presence of S. sciureus, C. jacchus eating, foraging, resting, socializing, and self-grooming behaviors were reduced while alertness was increased. Territorial behavior showed no significant difference. In the presence of S. sciureus, on average, the group of marmosets assembled at a higher layer of the forest stratum. The results might indicate a negative effect of S. sciureus on the native species, C. jacchus.

A decadal cirrus clouds climatology from ground-based and spaceborne lidars above the south of France (43.9° N–5.7° E)

This study provides an analysis of cirrus cloud properties at midlatitude in the southern part of France from ground-based and spaceborne lidars. A climatology of cirrus cloud properties and their evolution over more than 12 yr is presented and compared to other mid-latitude climatological studies. Cirrus clouds occur ~37% of the total observation time and remain quasi-constant across seasons with a variation within ~5% around the mean occurrence. Similar results are obtained from CALIOP and the ground-based lidar, with a mean difference in occurrence of ~5% between both instruments. From the ground-based lidar data, a slight decrease in occurrence of ~3% per decade is observed but found statistically insignificant. Based on a clustering analysis of cirrus cloud parameters, three distinct classes have been identified and investigations concerning their origin are discussed. Properties of these different classes are analysed, showing that thin cirrus in the upper troposphere represent ~50% of cloud cover detected in summer and fall, decreasing by 15–20% for other seasons.

A decadal cirrus clouds climatology from ground-based and spaceborne lidars above south of France (43.9° N–5.7° E)

This study provides an analysis of cirrus clouds properties at midlatitude in the southern part of France from ground-based and spaceborne lidars. A climatology of cirrus clouds properties and their evolution over more than 12 yr is presented and compared to other mid-latitude climatological studies. Cirrus clouds occur ~ 37% of the total observation time and remain quasi-constant across seasons with a variation within ~ 5% around the mean occurrence. Similar results are obtained from CALIOP and the ground-based lidar, with a mean difference in occurrence of ~ 5% between both instruments. From the ground-based lidar data, a slight decrease in occurrence of ~ 3% per decade is observed but found statistically insignificant. Based on a clustering analysis of cirrus cloud parameters, three distinct classes have been identified and investigations concerning their origin are discussed. Properties of these different classes are analysed, showing that thin cirrus in the upper troposphere represent ~ 50% of cloud cover detected in summer and fall, decreasing by 15–20% for other seasons.

Features of spontaneous pointing gestures in toddlers

This study investigated the production of spontaneous pointing gestures in 26 toddlers, who were observed during free play time at day nursery. Pointing gestures and their different features (e.g., handedness, vocalizations, form and function of gesture) were recorded for a total observation time of 100 hours. Results revealed that the vast majority of pointing gestures were right-handed and accompanied by vocalizations, emphasizing the tight interconnection between speech and gesture from an early stage of development. Whole-hand gestures were more frequently used in imperative contexts, whereas index extensions were more frequently produced in declarative ones. Moreover, the use of declarative gestures and index extensions were found to increase with age. Implications concerning the origins of imperative and declarative pointing are discussed.