ABSTRACT
Using the horizon-AGN hydrodynamical simulation and self-organizing maps (SOMs), we show how to compress the complex, high-dimensional data structure of a simulation into a 2D grid, which ...greatly facilitates the analysis of how galaxy observables are connected to intrinsic properties. We first verify the tight correlation between the observed 0.3–5 μm broad-band colours of horizon-AGN galaxies and their high-resolution spectra. The correlation is found to extend to physical properties such as redshift, stellar mass, and star formation rate (SFR). This direct mapping from colour to physical parameter space still works after including photometric uncertainties that mimic the COSMOS survey. We then label the SOM grid with a simulated calibration sample to estimate redshift and SFR for COSMOS-like galaxies up to z ∼ 3. In comparison to state-of-the-art techniques based on synthetic templates, our method is comparable in performance but less biased at estimating redshifts, and significantly better at predicting SFRs. In particular, our ‘data-driven’ approach, in contrast to model libraries, intrinsically allows for the complexity of galaxy formation and can handle sample biases. We advocate that observations to calibrate this method should be one of the goals of next-generation galaxy surveys.
Euclid preparation Adam, R.; Vannier, M.; Maurogordato, S. ...
Astronomy and astrophysics (Berlin),
07/2019, Volume:
627
Journal Article
Peer reviewed
Open access
Galaxy cluster counts in bins of mass and redshift have been shown to be a competitive probe to test cosmological models. This method requires an efficient blind detection of clusters from surveys ...with a well-known selection function and robust mass estimates, which is particularly challenging at high redshift. The
Euclid
wide survey will cover 15 000 deg
2
of the sky, avoiding contamination by light from our Galaxy and our solar system in the optical and near-infrared bands, down to magnitude 24 in the
H
-band. The resulting data will make it possible to detect a large number of galaxy clusters spanning a wide-range of masses up to redshift ∼2 and possibly higher. This paper presents the final results of the
Euclid
Cluster Finder Challenge (CFC), fourth in a series of similar challenges. The objective of these challenges was to select the cluster detection algorithms that best meet the requirements of the
Euclid
mission. The final CFC included six independent detection algorithms, based on different techniques, such as photometric redshift tomography, optimal filtering, hierarchical approach, wavelet and friend-of-friends algorithms. These algorithms were blindly applied to a mock galaxy catalog with representative
Euclid
-like properties. The relative performance of the algorithms was assessed by matching the resulting detections to known clusters in the simulations down to masses of
M
200
∼ 10
13.25
M
⊙
. Several matching procedures were tested, thus making it possible to estimate the associated systematic effects on completeness to < 3%. All the tested algorithms are very competitive in terms of performance, with three of them reaching > 80% completeness for a mean purity of 80% down to masses of 10
14
M
⊙
and up to redshift
z
= 2. Based on these results, two algorithms were selected to be implemented in the
Euclid
pipeline, the Adaptive Matched Identifier of Clustered Objects (AMICO) code, based on matched filtering, and the PZWav code, based on an adaptive wavelet approach.
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FMFMET, NUK, UL, UM, UPUK
Galaxy cluster counts in bins of mass and redshift have been shown to be a competitive probe to test cosmological models. This method requires an efficient blind detection of clusters from surveys ...with a well-known selection function and robust mass estimates. The Euclid wide survey will cover 15000 deg\(^2\) of the sky in the optical and near-infrared bands, down to magnitude 24 in the \(H\)-band. The resulting data will make it possible to detect a large number of galaxy clusters spanning a wide-range of masses up to redshift \(\sim 2\). This paper presents the final results of the Euclid Cluster Finder Challenge (CFC). The objective of these challenges was to select the cluster detection algorithms that best meet the requirements of the Euclid mission. The final CFC included six independent detection algorithms, based on different techniques, such as photometric redshift tomography, optimal filtering, hierarchical approach, wavelet and friend-of-friends algorithms. These algorithms were blindly applied to a mock galaxy catalog with representative Euclid-like properties. The relative performance of the algorithms was assessed by matching the resulting detections to known clusters in the simulations. Several matching procedures were tested, thus making it possible to estimate the associated systematic effects on completeness to \(<3\)%. All the tested algorithms are very competitive in terms of performance, with three of them reaching \(>80\)% completeness for a mean purity of 80% down to masses of \(10^{14}\) M\(_{\odot}\) and up to redshift \(z=2\). Based on these results, two algorithms were selected to be implemented in the Euclid pipeline, the AMICO code, based on matched filtering, and the PZWav code, based on an adaptive wavelet approach. abridged
Abstract Background: The emergence of multidrug-resistant nosocomial pathogens, such as Pseudomonas aeruginosa and Acinetobacter baumannii , has led to the revival of the systemic use of ...antimicrobial agent colistin in critically ill patients, but only limited data are available to define its pharmacokinetic profile in these patients. Objective: The aim of this study was to assess steady-state serum concentrations of colistin after IV administration of colistin methanesulfonate (CMS) in critically ill patients with stable kidney function. Methods: This prospective, open-label, uncontrolled study was conducted at 2 intensive care units in the Athens Trauma Hospital, KAT, Athens, Greece. Adult patients were nonconsecutively enrolled if they were critically ill and had stable kidney function (<0.5 mg/dL change in serum creatinine prior to and until the day of sample collection) and had been receiving CMS as part of a treatment regimen for sepsis irrespective of site of infection with multidrug-resistant, gram-negative bacilli. After IV administration of 225-mg CMS (with the exception of 1 patient who received 150 mg) every 8 or 12 hours for at least 2 days, blood samples were collected just before and at 10 minutes and 1, 2, 4, 6, and 8 hours after IV infusion (duration, 30 minutes) of the colistin dose on the sampling day. Results: Fourteen nonconsecutive patients were enrolled in the study (13 male, 1 female; mean SD age, 62.0 19.2 years; mean SD estimated weight, 72.5 8.5 kg; mean SD Acute Physiology And Chronic Health Evaluation II score on admission, 17.1 6.0). At steady state, mean (SD) colistin maximum and minimum concentrations were 2.93 (1.24) and 1.03 (0.44) mg/L, respectively, while mean (SD) apparent total body clearance, apparent volume of distribution, and t1/2 were 13.6 (5.8) L/h, 139.9 (60.3) L, and 7.4 (1.7) hours, respectively. Colistin-related nephrotoxicity was not observed in the study patients. Conclusion: CMS dosage regimens administered to these critically ill adult patients were associated with suboptimal Cmax/MIC ratios for many strains of gram-negative bacilli currently reported as sensitive (MIC, ≤2 μg/mL).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The increasing prevalence of multiresistant Gram-negative strains in intensive care units (ICUs) has recently rekindled interest in colistin, a bactericidal antibiotic that was used in the 1960s for ...treatment of infections caused by Gram-negative bacilli. We conducted the present observational study to evaluate the efficacy of intravenous colistin in the treatment of critically ill patients with sepsis caused by Gram-negative bacilli resistant to all other antibiotics.
Critically ill patients with sepsis caused by Gram-negative bacilli resistant to all antibiotics with the exception of colistin were treated in the six-bed ICU of a trauma hospital. Diagnosis of infection was based on clinical data and isolation of bacteria, and the bacteria were tested with respect to their susceptibility to colistin. Clinical response to colistin was evaluated.
Twenty-four patients (mean age 44.3 years, mean Acute Physiology and Chronic Health Evaluation II score 20.6) received 26 courses of colistin. Clinical response was observed for 73% of the treatments. Survival at 30 days was 57.7%. Deterioration in renal function was observed in 14.3% of 21 patients who were not already receiving renal replacement therapy, but in only one case did this deterioration have serious clinical consequences.
The lack of a control group in the present study does not allow any definite conclusions to be drawn regarding the clinical effectiveness of colistin. On the other hand, this drug has an acceptable safety profile and its use should be considered in severe infections with multiresistant Gram-negative bacilli.
Background: Limited English language proficiency in patients undergoing total shoulder arthroplasty (TSA) may make treatment more challenging. Purpose: We sought to investigate the potential ...association between TSA patients’ use of a language interpreter and 2 outcomes: hospital length of stay (LOS) and discharge disposition. Methods: We conducted a retrospective cohort study comparing LOS and discharge disposition after TSA for patients who required interpreter services and patients who did not at a single institution in an urban setting between 2016 and 2020. Consecutive patients requiring interpreter services who underwent TSA were matched 1:1 to patients who did not require an interpreter by age, body mass index (BMI), sex, and procedure. Multivariate regression models controlling for age, BMI, sex, smoking, opioid use, white or non-white race, procedure, and diagnosis were constructed to determine associations between interpreter use, LOS, and discharge disposition. Results: Forty-one patients were included in each cohort, exceeding the minimum number required per an a priori power analysis. Mean hospital LOS was longer in the interpreter cohort than in the non-interpreter cohort (2.8 ± 2.4 vs 1.8 ± 1.0 days, respectively). Multivariate linear regression demonstrated interpreter use was the strongest predictor of LOS, with the effect estimate indicating an additional 0.88-day LOS per patient. A greater proportion of patients from the interpreter cohort were discharged to an acute/subacute rehabilitation facility than patients from the non-interpreter cohort (n = 8 19.5% vs n = 2 4.9%, respectively). Patients from the interpreter cohort were 454% more likely to be discharged to acute/subacute rehabilitation facilities. Conclusions: Our retrospective analysis of patients undergoing TSA suggests that the need for interpreter services may be associated with increased LOS and discharge to a facility. More rigorous study is needed to identify the factors that influence these outcomes and to avoid disparities in hospital stay and discharge.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
To investigate the relationship of pressure in the inferior vena cava (Pivc) with a) pressure in the superior vena cava (Psvc), b) intra-abdominal pressure as measured in the urinary bladder (Pcyst).
...A prospective study of 38 mechanically ventilated patients. Simultaneous measurements of Psvc, Pivc and Pcyst (151 sets of measurements) were performed. Measurements were divided in: Group A (Pcyst < 10 mmHg), group B (10 mmHg < or = Pcyst < 15 mmHg), group C (Pcyst > or = 15 mmHg). Statistical analysis was performed with paired t-test, Pearson correlation. Results are expressed in mean +/- SEM.
In Groups A and B, Psvc and Pivc were not significantly different and they were highly correlated (10.8+/-0.5 mmHg vs. 10.9+/-0.5 mmHg, r=0.93 for Group A and 14.4+/-0.7 mmHg vs. 14.7+/-0.6 mmHg, r=0.87 for Group B). Pcyst was significantly lower than Pivc in both groups. In Group C, Pivc was significantly higher than Psvc (18.9+/-0.7 mmHg vs. 16.4+/-0.7 mmHg). There was no significant difference between Pivc and Pcyst (19.2+/-0.6 mmHg). Pivc significantly correlated with Pcyst (r=0.78) and Psvc (r=0.7). A. When Pcyst > Psvc, Pivc was higher than Psvc (p<0.01). With Pcyst < 15 mmHg, no significant difference was found between Pcyst and Pivc and they were correlated (r=0.766, p<0.05). Pressures in the superior and inferior vena cava were also correlated (r=0.764, p<0.05). With Pcyst > or = 15 mmHg, Pivc was lower than Pcyst (p<0.01). It correlated highly with Pcyst (r=0.85, p<0.01) and less strongly with Psvc (r=0.701, p<0.01). B. When Pcyst < or = Psvc, no difference between Pivc and Psvc was observed. With Pcyst < 15 mmHg, Pivc was higher than Pcyst (p<0.01) and highly correlated with Psvc (r=0.932, p<0.01). Pivc also correlated with Pcyst (r=0.69, p<0.01). With Pcyst > or = 15 mmHg, Pivc was higher than Pcyst (p<0.01) and correlated with Psvc (r=0.74, p<0.01) and Pcyst (r=0.789, p<0.01).
Although Psvc and Pivc are interchangeable in the absence of an increased Pcyst, when Pcyst is high, measurements of Pivc are misleading. A Pcyst > Psvc results in a "waterfall" effect, and Pivc does not accurately reflect Psvc any more.
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