scholarly journals Multitracer extension of the halo model: probing quenching and conformity in eBOSS

2020 ◽  
Vol 497 (1) ◽  
pp. 581-595 ◽  
Author(s):  
Shadab Alam ◽  
John A Peacock ◽  
Katarina Kraljic ◽  
Ashley J Ross ◽  
Johan Comparat
Keyword(s):  
Statistical Significance ◽  
Low Density ◽  
Galaxy Distribution ◽  
Upper Limits ◽  
Quenching Efficiency ◽  
The Galaxy ◽  
Best Fitting ◽  
The Mean ◽  
Halo Masses ◽  
Halo Occupation Distribution

ABSTRACT We develop a new Multitracer Halo Occupation Distribution (MTHOD) framework for the galaxy distribution and apply it to the extended Baryon Oscillation Spectroscopic Survey (eBOSS) final data between z = 0.7 − 1.1. We obtain a best fitting MTHOD  for each tracer and describe the host halo properties of these galaxies. The mean halo masses for LRGs, ELGs, and QSOs are found to be $1.9 \times 10^{13} \, h^{-1}M_\odot$, $1.1 \times 10^{12} \, h^{-1}M_\odot$, and $5 \times 10^{12} \, h^{-1}M_\odot$ respectively in the eBOSS data. We use the MTHOD  framework to create mock galaxy catalogues and predict auto- and cross-correlation functions for all the tracers. Comparing these results with data, we investigate galactic conformity, the phenomenon whereby the properties of neighbouring galaxies are mutually correlated in a manner that is not captured by the basic halo model. We detect 1-halo conformity at more than 3σ statistical significance, while obtaining upper limits on 2-halo conformity. We also look at the environmental dependence of the galaxy quenching efficiency and find that halo mass driven quenching successfully explains the behaviour in high density regions, but it fails to describe the quenching efficiency in low density regions. In particular, we show that the quenching efficiency in low density filaments is higher in the observed data, as compared to the prediction of the MTHOD with halo mass driven quenching. The mock galaxy catalogue constructed in this paper is publicly available on this website1.

scholarly journals A study on the statistical significance of mutual information between morphology of a galaxy and its large-scale environment

2020 ◽  
Vol 497 (4) ◽  
pp. 4077-4090 ◽  
Author(s):  
Suman Sarkar ◽  
Biswajit Pandey
Keyword(s):  
Mutual Information ◽  
Large Scale ◽  
Statistical Significance ◽  
Sloan Digital Sky Survey ◽  
Data Sets ◽  
Information Theoretic ◽  
Galaxy Distribution ◽  
Sky Survey ◽  
The Galaxy ◽  
Physical Correlations

ABSTRACT A non-zero mutual information between morphology of a galaxy and its large-scale environment is known to exist in Sloan Digital Sky Survey (SDSS) upto a few tens of Mpc. It is important to test the statistical significance of these mutual information if any. We propose three different methods to test the statistical significance of these non-zero mutual information and apply them to SDSS and Millennium run simulation. We randomize the morphological information of SDSS galaxies without affecting their spatial distribution and compare the mutual information in the original and randomized data sets. We also divide the galaxy distribution into smaller subcubes and randomly shuffle them many times keeping the morphological information of galaxies intact. We compare the mutual information in the original SDSS data and its shuffled realizations for different shuffling lengths. Using a t-test, we find that a small but statistically significant (at $99.9{{\ \rm per\ cent}}$ confidence level) mutual information between morphology and environment exists upto the entire length-scale probed. We also conduct another experiment using mock data sets from a semi-analytic galaxy catalogue where we assign morphology to galaxies in a controlled manner based on the density at their locations. The experiment clearly demonstrates that mutual information can effectively capture the physical correlations between morphology and environment. Our analysis suggests that physical association between morphology and environment may extend to much larger length-scales than currently believed, and the information theoretic framework presented here can serve as a sensitive and useful probe of the assembly bias and large-scale environmental dependence of galaxy properties.

scholarly journals Can assembly bias explain the lensing amplitude of the BOSS CMASS sample in a Planck cosmology?

2020 ◽  
Vol 493 (4) ◽  
pp. 5551-5564
Author(s):  
Sihan Yuan ◽  
Daniel J Eisenstein ◽  
Alexie Leauthaud
Keyword(s):  
Cold Dark Matter ◽  
Cosmological Parameters ◽  
Bias Parameter ◽  
Projected Clustering ◽  
The Galaxy ◽  
Satellite Velocity ◽  
Galaxy Sample ◽  
Best Fitting ◽  
Galaxy Assembly ◽  
Halo Occupation Distribution

ABSTRACT In this paper, we investigate whether galaxy assembly bias can reconcile the 20–40 ${{\ \rm per\ cent}}$ disagreement between the observed galaxy projected clustering signal and the galaxy–galaxy lensing signal in the Baryon Oscillation Spectroscopic Survey CMASS galaxy sample. We use the suite of abacuscosmos lambda cold dark matter simulations at Planck best-fitting cosmology and two flexible implementations of extended halo occupation distribution (HOD) models that incorporate galaxy assembly bias to build forward models and produce joint fits of the observed galaxy clustering signal and the galaxy–galaxy lensing signal. We find that our models using the standard HODs without any assembly bias generalizations continue to show a 20–40 ${{\ \rm per\ cent}}$ overprediction of the observed galaxy–galaxy lensing signal. We find that our implementations of galaxy assembly bias do not reconcile the two measurements at Planck best-fitting cosmology. In fact, despite incorporating galaxy assembly bias, the satellite distribution parameter, and the satellite velocity bias parameter into our extended HOD model, our fits still strongly suggest a $\sim \! 34{{\ \rm per\ cent}}$ discrepancy between the observed projected clustering and galaxy–galaxy lensing measurements. It remains to be seen whether a combination of other galaxy assembly bias models, alternative cosmological parameters, or baryonic effects can explain the amplitude difference between the two signals.

scholarly journals Faint Structures in Low Density Regions of the Nearby Universe

1999 ◽  
Vol 183 ◽  
pp. 256-256
Author(s):  
U. Lindner ◽  
K.J. Fricke ◽  
J. Einasto ◽  
M. Einasto
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Morphological Type ◽  
High Density ◽  
Low Density ◽  
Clusters Of Galaxies ◽  
Galaxy Distribution ◽  
The Galaxy ◽  
Empty Sphere ◽  
First Time

We present an investigation of the galaxy distribution in the huge underdense region between the Hercules, Coma and Local Superclusters, the so-called Northern Local Void (NLV), using void statistics (for details refer to Lindner et al. this Volume). Reshift data for galaxies and poor clusters of galaxies are available in low and high density regions as well. Samples of galaxies with different morphological type and various luminosity limits have been studied separately and void catalogues have been compiled from three different luminosity limited galaxy samples for the first time. Voids have been found using the empty sphere method which has the potential to detect and describe subtle structures in the galaxy distribution. Our approach is complementary to most other methods usually used in Large–Scale Structure studies.

scholarly journals Mapping the Hidden Universe: The Galaxy Distribution in the Zone of Avoidance

2000 ◽  
Vol 17 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Renée C. Kraan-Korteweg ◽  
Sebastian Juraszek
Keyword(s):  
Milky Way ◽  
Current Status ◽  
Microwave Background ◽  
Galaxy Distribution ◽  
Velocity Flow ◽  
The Galaxy ◽  
The Mean ◽  
Zone Of Avoidance ◽  
Mean Time ◽  
Great Attractor

AbstractDue to the foreground extinction of the Milky Way, galaxies become increasingly faint as they approach the Galactic Equator creating a ‘zone of avoidance’ (ZOA) in the distribution of optically visible galaxies of about 25%. A ‘whole-sky’ map of galaxies is essential, however, for understanding the dynamics in our local Universe, in particular the peculiar velocity of the Local Group with respect to the Cosmic Microwave Background and velocity flow fields such as in the Great Attractor (GA) region. The current status of deep optical galaxy searches behind the Milky Way and their completeness as a function of foreground extinction will be reviewed. It has been shown that these surveys—which in the mean time cover the whole ZOA (Figure 2)—result in a considerable reduction of the ZOA from extinction levels of AB =1m.0 (Figure 1) to AB =3m.0 (Figure 3). In the remaining, optically opaque ZOA, systematic HI surveys are powerful in uncovering galaxies, as is demonstrated for the GA region with data from the full sensitivity Parkes Multibeam HI survey (300°≤l≤332°, ∣b∣≤5°.5, Figure 4).

scholarly journals The Sheet of Giants: Unusual properties of the Milky Way’s immediate neighbourhood

2020 ◽  
Vol 494 (2) ◽  
pp. 2600-2617 ◽  
Author(s):  
Maria K Neuzil ◽  
Philip Mansfield ◽  
Andrey V Kravtsov
Keyword(s):  
Milky Way ◽  
Number Density ◽  
Local Volume ◽  
Oblate Ellipsoid ◽  
Galaxy Distribution ◽  
Λcdm Model ◽  
The Galaxy ◽  
Nearby Galaxies ◽  
The Mean ◽  
The Impact

ABSTRACT We quantify the shape and overdensity of the galaxy distribution in the ‘Local Sheet’ within a sphere of R = 8 Mpc and compare these properties with the expectations of the ΛCDM model. We measure ellipsoidal axis ratios of c/a ≈ 0.16 and b/a ≈ 0.79, indicating that the distribution of galaxies in the Local Volume can be approximated by a flattened oblate ellipsoid, consistent with the ‘sheet’-like configuration noted in previous studies. In contrast with previous estimates that the Local Sheet has a density close to average, we find that the number density of faint and bright galaxies in the Local Volume is ≈1.7 and ≈5.2 times denser, respectively, than the mean number density of galaxies of the same luminosity. Comparison with simulations shows that the number density contrasts of bright and faint galaxies within 8 Mpc alone make the Local Volume a ≈2.5 σ outlier in the ΛCDM cosmology. Our results indicate that the cosmic neighbourhood of the Milky Way may be unusual for galaxies of similar luminosity. The impact of the peculiar properties of our neighbourhood on the properties of the Milky Way and other nearby galaxies is not yet understood and warrants further study.

A multicenter prospective hospital-based cohort study on the efficacy and safety of pitavastatin.

2020 ◽  
Vol 17 ◽  
Author(s):  
Abdullah Shehab ◽  
Asim Ahmed Elnour ◽  
Akshaya Srikanth Bhagavathula ◽  
Joseph Pulavelil Kurian ◽  
Gazi Hassan ◽  
...  
Keyword(s):  
Cohort Study ◽  
Adverse Events ◽  
United Arab Emirates ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Efficacy And Safety ◽  
Onset Diabetes ◽  
The Mean ◽  
New Onset

Aims: We aim to investigate the efficacy and safety of pitavastatin 4 mg in a population of people living in the United Arab Emirates (UAE). Background: Pitavastatin is a member of the HMG-CoA reductase inhibitors family which was approved for use in adult subjects with primary hyperlipidemia or mixed dyslipidemia. To date, no published studies have assessed the efficacy and safety of pitavastatin in the United Arab Emirates. Objective: The main objective of the current study was to investigate the efficacy and safety of pitavastatin in subjects with dyslipidemia for primary prevention of cardiovascular diseases based on total cardiovascular risk. Methods: This was a multicentre (four private hospitals) prospective cohort study to analyze data on the use of pitavastatin for dyslipidemia in adult outpatients in Abu Dhabi and Dubai emirates, United Arab Emirates. We have followed-up the clinical profiles of subjects in four hospitals for six-weeks during the period from June 2015 to June 2017. Efficacy was based on the evaluation of the mean (± standard deviation) change in low-density lipoprotein cholesterol between baseline and week six after the initiation of pitavastatin therapy. Safety was reported as the incidence of adverse events occurred with the use of pitavastatin and the development of new-onset diabetes. Results: A total of 400 subjects who were receiving pitavastatin 4 mg were included. The mean age of subjects was 50.7 ±10.8 years, of these 79.0% were males. At the baseline, the mean level of total cholesterol was 185.4 ±41.5 mg/dL, low density lipoprotein was 154.9 ±48.55 mg/dL, high-density lipoprotein cholesterol was 40.5 ±11.23 mg/dL and fasting blood glucose was 115.0 (±16.63) mg/dl. At the end of six weeks, low density lipoprotein levels significantly decreased to 112.09 ±41.90 mg/dl (standard mean difference [SMD] (-42.8%), 95% CI: -42.88 [-49.17 to -36.58] mg/dl, P <0.001), while high density lipoprotein levels improved (SMD, 95% CI: 1.77% [0.25 to 3.28] mg/dl, P <0.022). There were 55 subjects (13.7%) reported various adverse events such as myalgia (7.5%), sleep disorders (2.5%), and myopathy (2.2%). Furthermore, 4 (1.0%) have had developed new-onset diabetes post six-weeks of initiation of pitavastatin therapy. Conclusion: Pitavastatin 4 mg had howed robust efficacy in reducing LDL-C levels and improving HDL-C levels in subjects with dyslipidemias. The use of pitavastatin was associated with a low discontinuation rate, fewer adverse events, and very limited cases of new-onset diabetes.

Gingival Health of Porcelain Laminate Veneered Teeth: A Retrospective Assessment

2019 ◽  
Vol 44 (5) ◽  
pp. 452-458 ◽  
Author(s):  
R Arif ◽  
JB Dennison ◽  
D Garcia ◽  
P Yaman
Keyword(s):  
Repeated Measures ◽  
Gingival Crevicular Fluid ◽  
Statistical Significance ◽  
Fluid Collection ◽  
Gingival Recession ◽  
Gingival Health ◽  
Long Term Effect ◽  
The Mean ◽  
Crevicular Fluid

SUMMARY Statement of Problem: The long-term effect of the presence of porcelain laminate veneers (PLVs) on the health of the surrounding gingival issues is not available in the restorative literature. Purpose: To assess the long-term effect of PLVs on the health of the surrounding gingival tissues. A secondary aim was to correlate gingival crevicular fluid (GCF) scores with clinical parameters used for gingival health assessment in teeth treated with PLVs. Methods and Materials: Patients who received PLVs placed at the Graduate Restorative Clinic within a seven- to 14-year period were recalled for clinical evaluations. Periodontal measurements including gingival index (GI), periodontal pocket depth (PPD), gingival recession (GR), and clinical attachment level (CAL) were measured using a standard probe and indices. Gingival Crevicular Fluid (GCF) was measured with a Periotron machine (Periotron 8000, Oraflow Inc), using Periopaper (Periopaper Gingival Fluid Collection Strip, Oraflow Inc.) for fluid collection. Photographs of any observed clinical defect were taken. Data were tabulated using Excel 2010 (Microsoft Corp). Statistical analysis for all descriptive statistics was performed using SPSS 21 (SPSS Software, IBM Corp.) and Stata SE 13 (Stata Software, StataCorp). Repeated-measures analysis of variance (ANOVA) was done to test for statistical significance of the mean pocket depths between the restored and unrestored surfaces of the veneered teeth. The significance level for all tests was p&lt;0.05. Pearson's correlation coefficient was performed for testing statistical significance between GCF and GI and between GCF and PPD. Results: The frequency distribution of the GI included 47 PLVs (43%) with normal gingiva, 16 (15%) with mild inflammation, and 46 (42%) with moderate inflammation and bleeding on probing. The average PPD on the facial surface of the maxillary and mandibular PLVs was 2.17 mm and 2.16 mm, respectively. On the lingual surface, the average PPD was 2.10 mm for maxillary and 2.22 mm for mandibular PLVs. Gingival recession was seen in 27% of the evaluated PLVs. The repeated-measures ANOVA revealed p≥0.136, showing no statistical difference in the mean pocket depths between restored facial and unrestored lingual surfaces of the veneered teeth. A moderate correlation (r=0.407) was found between GCF and GI, which was significant at p&lt;0.001. No correlation (r=0.124) was found between GCF and PPD, which was not significant at p=0.197. Conclusions: Gingival response to the evaluated PLVs was in the satisfactory range, with overall GI scores ranging between normal and moderate inflammation, pocket depths ranging from 1 to 2 mm, and recession present in 27% of the evaluated PLVs. No statistically significant difference was found between the mean pocket depths of the restored and unrestored surfaces of veneered teeth (p≥0.136). A moderate correlation was found between GCF and GI.

scholarly journals Higher Caloric Refeeding Is Safe in Hospitalised Adolescent Patients with Restrictive Eating Disorders

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Elizabeth K. Parker ◽  
Sahrish S. Faruquie ◽  
Gail Anderson ◽  
Linette Gomes ◽  
Andrew Kennedy ◽  
...  
Keyword(s):  
Eating Disorders ◽  
Weight Gain ◽  
Statistical Significance ◽  
Caloric Intake ◽  
Tube Feeding ◽  
Retrospective Chart Review ◽  
Refeeding Syndrome ◽  
Restrictive Eating ◽  
Weight Restoration ◽  
The Mean

Introduction. This study examines weight gain and assesses complications associated with refeeding hospitalised adolescents with restrictive eating disorders (EDs) prescribed initial calories above current recommendations.Methods. Patients admitted to an adolescent ED structured “rapid refeeding” program for >48 hours and receiving ≥2400 kcal/day were included in a 3-year retrospective chart review.Results. The mean (SD) age of the 162 adolescents was 16.7 years (0.9), admission % median BMI was 80.1% (10.2), and discharge % median BMI was 93.1% (7.0). The mean (SD) starting caloric intake was 2611.7 kcal/day (261.5) equating to 58.4 kcal/kg (10.2). Most patients (92.6%) were treated with nasogastric tube feeding. The mean (SD) length of stay was 3.6 weeks (1.9), and average weekly weight gain was 2.1 kg (0.8). No patients developed cardiac signs of RFS or delirium; complications included 4% peripheral oedema, 1% hypophosphatemia (<0.75 mmol/L), 7% hypomagnesaemia (<0.70 mmol/L), and 2% hypokalaemia (<3.2 mmol/L). Caloric prescription on admission was associated with developing oedema (95% CI 1.001 to 1.047;p=0.039). No statistical significance was found between electrolytes and calories provided during refeeding.Conclusion. A rapid refeeding protocol with the inclusion of phosphate supplementation can safely achieve rapid weight restoration without increased complications associated with refeeding syndrome.

scholarly journals Prospective Analysis of Coagulopathy Associated with Isolated Traumatic Brain Injury and Clinical Outcome

2021 ◽  
Author(s):  
Gopal Krishna ◽  
Varun Aggarwal ◽  
Ishwar Singh
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Head Injury ◽  
Clinical Outcome ◽  
Road Traffic ◽  
Statistical Significance ◽  
Platelet Counts ◽  
Coagulation Abnormalities ◽  
The Mean ◽  
D Dimer

Abstract Introduction Traumatic brain injury (TBI) affects the coagulation pathway in a distinct way than does extracranial trauma. The extent of coagulation abnormalities varies from bleeding diathesis to disseminated thrombosis. Design Prospective study. Methods The study included 50 patients of isolated TBI with cohorts of moderate (MHI) and severe head injury (SHI). Coagulopathy was graded according to the values of parameters in single laboratory. The incidence of coagulopathy according to the severity of TBI and correlation with disseminated intravascular coagulation (DIC) score, platelets, prothrombin time (PT), activated partial thromboplastin time (APTT), D-dimer, and fibrinogen was observed. The comparison was also made between expired and discharged patients within each group. It also compared coagulation derailments with clinical presentation (Glasgow Coma Scale [GCS]) and outcome (Glasgow Outcome Scale [GOS]). Results Road traffic accident was the primary (72%) mode of injury. Fifty-two percent had MHI and rest had SHI. Eighty-four percent of cases were managed conservatively. The mean GCS was 12.23 and 5.75 in MHI and SHI, respectively. Sixty-two percent of MHI and 96% of the patients with SHI had coagulation abnormalities. On statistical analysis, DIC score (p < 0.001) strongly correlated with the severity of head injury and GOS. PT and APTT were also significantly associated with the severity of TBI. In patients with moderate TBI, D-dimer and platelet counts showed association with clinical outcome. Fibrinogen levels did not show any statistical significance. The mean platelet counts remained normal in both the groups of TBI. The mean GOS was 1.54 and 4.62 in SHI and MHI, respectively. Conclusion Coagulopathy is common in isolated TBI. The basic laboratory parameters are reliable predictors of coagulation abnormalities in TBI. Coagulopathy is directly associated with the severity of TBI, GCS, and poor outcome.

scholarly journals POS1281 HOW DOES OBESITY INFLUENCE THE FEATURES OF KNEE OSTEOARTHRITIS?

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 923.4-924
Author(s):  
H. Hachfi ◽  
D. Khalifa ◽  
M. Brahem ◽  
N. Ben Chekaya ◽  
M. Younes
Keyword(s):  
Knee Osteoarthritis ◽  
Functional Impairment ◽  
Statistical Significance ◽  
Obese Group ◽  
University Hospital ◽  
Obese Patients ◽  
Cross Sectional ◽  
Duration Of Symptoms ◽  
Lequesne Index ◽  
The Mean

Background:Knee osteoarthritis and obesity are both major health problems. It is now admitted that the prevalence of knee osteoarthritis gets higher with obesity and that weight loss helps knee function and allows patients to avoid surgery.Objectives:The aim of this study was to study the influence of obesity on knee osteoarthritis features.Methods:A cross-sectional study was conducted in the university hospital Taher Sfar of Tunisia over a period of 6 months. Patients who had knee osteoarthritis confirmed by radiographs were included. Sociodemographic, clinical, radiological and therapeutic data were collected from medical records and visits. Obesity was defined by a body mass index (BMI) ≥30. Functional impairment was assessed by the Womac index and Lequesne index.Results:The study included 186 patients. There were 31 males and 155 femmes. The mean age was 60±10 years. The percentage of obese patients was 53,8%. The mean age was similar in both groups obese and non obese. There were more women in the obese group compared to the non obese group (p=0.0001), more patients who had diabetes mellitus and dyslipidemia (p=0.002). Non-obese patients had a shorter duration of symptoms with no statistical significance (p=0.151). Obese patients had more involvement of both knees (p<0.0001). Obesity did not have an impact on pain severity. Severity of radiological images (p=0,0001) were more frequent in obese patients. Functional impairment was similar in both groups. However, the percentage of patients having a very important functional impairment with Lequesne index was higher in obese patients (p<0.029). Obese patients also needed more physical therapy sessions (p=0.035).Conclusion:Knee osteoarthritis in obese patients is characterized with the femlae gender predominance, bilateral knee involvement, and a more severe images on radiographs. Thus the need for better control of weight and the importance of physical activity.References:[1]Coggon D, Reading I, Croft P, et al. Knee osteoarthritis and obesity. Int J Obes Relat Metab Disord J Int Assoc Study Obes 2001; 25: 622–627.Disclosure of Interests:None declared

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