Massive dark matter haloes around bright isolated galaxies in the 2dFGRS

We identify a large sample of isolated bright galaxies and their fainter satellites in the 2dF Galaxy Redshift Survey (2dFGRS). We analyse the dynamics of ensembles of these galaxies selected according to luminosity and morphological type by stacking the positions of their satellites and estimating the velocity dispersion of the combined set. We test our methodology using realistic mock catalogues constructed from cosmological simulations. The method returns an unbiased estimate of the velocity dispersion provided that the isolation criterion is strict enough to avoid contamination and that the scatter in halo mass at fixed primary luminosity is small. Using a maximum likelihood estimator that accounts for interlopers, we determine the satellite velocity dispersion within a projected radius of 175 h−1kpc. The dispersion increases with the luminosity of the primary and is larger for elliptical galaxies than for spiral galaxies of similar bJ luminosity. Calibrating the mass-velocity dispersion relation using our mock catalogues, we find a dynamical mass within 175 h−1kpc of for elliptical galaxies and for spiral galaxies. Finally, we compare our results with recent studies and investigate their limitations using our mock catalogue

Luminosity Tuning at the Interaction Point

Minimisation of the emittance in a linear collider is not enough to achieve optimal performance. For optimisation of the luminosity, tuning of collision parameters such as angle, offset, waist, etc. is needed, and a fast and reliable tuning signal is required. In this paper tuning knobs are presented, and their optimisation using beamstrahlung as a tuning signal is studied

Void Statistics in Large Galaxy Redshift Surveys: Does Halo Occupation of Field Galaxies Depend on Environment?

We use measurements of the projected galaxy correlation function w_p and galaxy void statistics to test whether the galaxy content of halos of fixed mass is systematically different in low density environments. We present new measurements of the void probability function (VPF) and underdensity probability function (UPF) from Data Release Four of the Sloan Digital Sky Survey, as well as new measurements of the VPF from the full data release of the Two-Degree Field Galaxy Redshift Survey. We compare these measurements to predictions calculated from models of the Halo Occupation Distribution (HOD) that are constrained to match both w_p and the space density of galaxies. The standard implementation of the HOD assumes that galaxy occupation depends on halo mass only, and is independent of local environment. For luminosity-defined samples, we find that the standard HOD prediction is a good match to the observations, and the data exclude models in which galaxy formation efficiency is reduced in low-density environments. More remarkably, we find that the void statistics of red and blue galaxies (at L ~ 0.4L_*) are perfectly predicted by standard HOD models matched to the correlation function of these samples, ruling out "assembly bias" models in which galaxy color is correlated with large-scale environment at fixed halo mass. We conclude that the luminosity and color of field galaxies are determined predominantly by the mass of the halo in which they reside and have little direct dependence on the environment in which the host halo formed. In broader terms, our results show that the sizes and emptiness of voids found in the distribution of L > 0.2L_* galaxies are in excellent agreement with the predictions of a standard cosmological model with a simple connection between galaxies and dark matter halos. (abridged)Comment: 20 emulateapj pages, 9 figures. submitted to Ap

Continuity of GP care is associated with lower use of complementary and alternative medical providers: a population-based cross-sectional survey

BACKGROUND: Continuity of general practitioner (GP) care is associated with reduced use of emergency departments, hospitalisation, and outpatient specialist services. Evidence about the relationship between continuity and use of complementary and alternative medical (CAM) providers has so far been lacking. The aim of this study was to test the association between continuity of GP care and the use of CAM providers. METHODS: We used questionnaire data from the sixth Tromsø Study, conducted in 2007–8. Using descriptive statistical methods, we estimated the proportion using a CAM provider among adults (30–87 years) who had visited a GP during the last 12 months. By means of logistic regressions, we studied the association between the duration of the GP-patient relationship and the use of CAM providers. Analyses were adjusted for the frequency of GP visits, gender, age, marital status, income, education, and self-rated health and other proxies for health care needs. RESULTS: Of 9,743 eligible GP users, 85.1% had seen the same GP for more than two years, 83.7% among women and 86.9% among men. The probability of visiting a CAM provider was lower among those with a GP relationship of more than 2 years compared to those with a shorter GP relationship (odds ratio [OR] 0.81, 95% confidence interval [CI] 0.68-0.96). Other factors associated with CAM use were female gender, poor health, low age and high income. There was no association with education. CONCLUSIONS: Continuity of GP care as measured by the duration of the GP-patient relationship was associated with lower use of CAM providers. Together with previous studies this suggests that continuity of GP care may contribute to health care delivery from fewer providers

Thulium Fibre Laser versus Holmium:YAG for Ureteroscopic Lithotripsy: Outcomes from a Prospective Randomised Clinical Trial

Background Holmium:yttrium-aluminium-garnet (Ho:YAG) laser is the gold standard for ureterorenoscopic (URS) lithotripsy. Thulium fibre laser (TFL) has recently been introduced as a new technology and may challenge Ho:YAG as the preferred laser owing to favourable properties as demonstrated in preclinical studies. Objective To evaluate and compare outcomes after URS lithotripsy with Ho:YAG and TFL. Design, setting, and participants In a prospective randomised trial, patients aged ≥18 yr with ureteral and/or renal stones (≥5 mm) scheduled to undergo day-case URS lithotripsy were invited to participate. In total, 120 consecutively admitted patients with signed consent were included for randomisation. Intervention URS lithotripsy with Ho:YAG or TFL. Outcome measurements and statistical analysis The primary outcome was the stone-free rate (SFR) assessed on noncontrast computed tomography at 3-mo follow-up. Secondary outcomes were the operative time and complications. Outcomes were compared between the groups using the t test and χ2 test. Results and limitations After a single session, the SFR was 67% in the Ho:YAG group and 92% in the TFL group, p = 0.001. For ureteral stones, the SFR was 100% in both groups, and for renal stones; 49% (Ho:YAG) and 86% (TFL), p = 0.001. Operative time was shorter using TFL (49 min) compared to Ho:YAG (57 min), p = 0.008. Bleeding that impaired the endoscopic view was the most frequent intraoperative adverse event and occurred in 13 patients (22%) in the Ho:YAG group and three (5%) in the TFL group, p = 0.014. Conclusions In this study, significantly more patients with renal stones achieved stone-free status and fewer experienced intraoperative complications using TFL compared to Ho:YAG. TFL is the emerging laser of choice for stone lithotripsy. Patient summary We compared outcomes after ureterorenoscopic treatment of kidney and ureteral stones using two different lasers. Our results show that the new thulium fibre laser technology is superior to the current standard laser (holmium:YAG) in clearing kidney stones and reducing operative complications.publishedVersio

Ureteroscopy for stone disease in the paediatric population: lessons learned and outcomes in a Nordic setting

Introduction: Paediatric stone disease is rare in the Nordic communities. Still, the condition can require surgical intervention in the form of ureteroscopy (URS). Here, we report outcomes achieved at a regional (tertiary) centre. Patients and methods: Retrospective analysis was performed of consecutive patients (<18 years of age) undergoing URS for stone disease between 2010 and 2021. Outcomes of interest included stone-free rate (SFR) determined using a definition of no residual fragments ⩾ 3 mm on imaging and complications classified according to Clavien–Dindo system. Results: In total, 23 patients underwent 47 URS procedures for a total of 31 stone episodes. Mean age was 9 (range 1–17) years and male-to-female ratio was 6:17. Overall, 35% had at least one medical comorbidity. Ultrasound determined preoperative stone status in 87%. Mean largest index and cumulative stone sizes were 9 (range 3–40) and 12 (range 3–40) mm, respectively. Overall, 32% had multiple stones. Lower pole was the commonest stone location (39%). No patients underwent elective pre-operative stenting. Ureteral access sheaths were not used in any cases. Access to upper urinary tract at first procedure was successful in 94%. Initial and final SFR was 61% and 90%, respectively. No intra-operative complications were recorded. Overall post-operative complication rate was 17.5%. Urinary tract infection (CD II) was the commonest adverse event (12.5%). Conclusion: Paediatric URS can be delivered in the setting of a regional centre without compromising outcomes. This includes when carried out by adult endourologists, without routine pre-stenting and omitting use of ureteric access sheath.publishedVersio