The current status of observational cosmology

Observational cosmology has indeed made very rapid progress in recent years. The ability to quantify the universe has largely improved due to observational constraints coming from structure formation. The transition to precision cosmology has been spearheaded by measurements of the anisotropy in the cosmic microwave background (CMB) over the past decade. Observations of the large scale structure in the distribution of galaxies, high red-shift supernova, have provided the required complementary information. We review the current status of cosmological parameter estimates from joint analysis of CMB anisotropy and large scale structure (LSS) data. We also sound a note of caution on overstating the successes achieved thus far.Comment: 13 pages, 3 figures, Latex style files included, To appear in the proceedings of ICGC-04. Minor rewording in the abstract and introductio

A new class of Cu/ZnO catalysts derived from zincian georgeite precursors prepared by co-precipitation

Zincian georgeite, an amorphous copper-zinc hydroxycarbonate, has been prepared by co-precipitation using acetate salts and ammonium carbonate. Incorporation of zinc into the georgeite phase and mild ageing conditions inhibits crystallisation into zincian malachite or aurichalcite. This zincian georgeite precursor was used to prepare a Cu/ZnO catalyst, which exhibits a superior performance to a zincian malachite derived catalyst for methanol synthesis and the low temperature water-gas shift (LTS) reaction. Furthermore, the enhanced LTS activity and stability in comparison to that of a commercial Cu/ZnO/Al2O3 catalyst, indicates that the addition of alumina as a stabiliser may not be required for the zincian georgeite derived Cu/ZnO catalyst. The enhanced performance is partly attributed to the exclusion of alkali metals from the synthesis procedure, which are known to act as catalyst poisons. The effect of residual sodium on the microstructural properties of the catalyst precursor was investigated further with preparations using sodium carbonate

Preparation of a highly active ternary Cu-Zn-Al oxide methanol synthesis catalyst by supercritical CO2 anti-solvent precipitation

Methanol synthesis using Cu/ZnO/Al2O3 catalysts is a well-established industrial process. Catalyst development is always an important factor and this has resulted in the current fully optimised commercial catalyst that is prepared by co-precipitation via hydroxycarbonate precursors. Recently, the synthesis of a CuZn hydroxycarbonate precursor, analogous to the rare mineral georgeite, was reported to produce a high activity methanol synthesis catalyst. Here we report the addition of Al 3+ , the third component found in industrial catalysts, to the zincian georgeite-derived catalyst prepared using a supercritical CO 2 anti-solvent precipitation methodology. The co-addition of an AlO(OH) sol to the Cu/Zn precursor solution was found to not disrupt the formation of the CuZn georgeite phase, while providing efficient mixing of the Al 3+ within the material. The catalyst derived from the CuZn georgeite precursor phase doped with Al 3+ showed a high level of methanol synthesis productivity, which was comparable to that of the binary CuZn georgeite derived catalyst. This material also exhibited enhanced stability during an accelerated ageing test compared to the non-Al doped zincian georgeite material. Performance was benchmarked against an industrially relevant Cu/ZnO/Al2O3 standard catalyst

Putting the “We” Into Well‐being: Using Collectivism‐Themed Measures of Well‐Being Attenuates Well‐being's Association With Individualism

Studies repeatedly have documented that societal well‐being is associated with individualism. Most of these studies, however, have conceptualized/measured well‐being as individual life satisfaction—a type of well‐being that originates in Western research traditions. Drawing from the latest research on interdependent happiness and on family well‐being, we posit that people across cultures pursue different types of well‐being, and test whether more collectivism‐themed types of well‐being that originate in Confucian traditions also are associated with individualism. Based on data collected from 2,036 participants across 12 countries, we find support for the association between individual life satisfaction and individualism at the societal level, but show that well‐being's association with individualism is attenuated when some collectivism‐themed measures of well‐being are considered. Our article advances knowledge on the flourishing of societies by suggesting that individualism may not always be strongly linked with societal well‐being. Implications for public policies are signaled

Preparation of a highly active ternary Cu-Zn-Al oxide methanol synthesis catalyst by supercritical CO 2 anti-solvent precipitation

Methanol synthesis using Cu/ZnO/Al2O3 catalysts is a well-established industrial process. Catalyst development is always an important factor and this has resulted in the current fully optimised commercial catalyst that is prepared by co-precipitation via hydroxycarbonate precursors. Recently, the synthesis of a CuZn hydroxycarbonate precursor, analogous to the rare mineral georgeite, was reported to produce a high activity methanol synthesis catalyst. Here we report the addition of Al3+, the third component found in industrial catalysts, to the zincian georgeite-derived catalyst prepared using a supercritical CO2 anti-solvent precipitation methodology. The co-addition of an AlO(OH) sol to the Cu/Zn precursor solution was found to not disrupt the formation of the CuZn georgeite phase, while providing efficient mixing of the Al3+ within the material. The catalyst derived from the CuZn georgeite precursor phase doped with Al3+ showed a high level of methanol synthesis productivity, which was comparable to that of the binary CuZn georgeite derived catalyst. This material also exhibited enhanced stability during an accelerated ageing test compared to the non-Al doped zincian georgeite material. Performance was benchmarked against an industrially relevant Cu/ZnO/Al2O3 standard catalyst

Leukocyte surface biomarkers implicate deficits of innate immunity in sporadic Alzheimer\u27s disease

Introduction: Blood-based diagnostics and prognostics in sporadic Alzheimer\u27s disease (AD) are important for identifying at-risk individuals for therapeutic interventions. Methods: In three stages, a total of 34 leukocyte antigens were examined by flow cytometry immunophenotyping. Data were analyzed by logistic regression and receiver operating characteristic (ROC) analyses. Results: We identified leukocyte markers differentially expressed in the patients with AD. Pathway analysis revealed a complex network involving upregulation of complement inhibition and downregulation of cargo receptor activity and Aβ clearance. A proposed panel including four leukocyte markers – CD11c, CD59, CD91, and CD163 – predicts patients’ PET Aβ status with an area under the curve (AUC) of 0.93 (0.88 to 0.97). CD163 was the top performer in preclinical models. These findings have been validated in two independent cohorts. Conclusion: Our finding of changes on peripheral leukocyte surface antigens in AD implicates the deficit in innate immunity. Leukocyte-based biomarkers prove to be both sensitive and practical for AD screening and diagnosis

Early Restrictive or Liberal Fluid Management for Sepsis-Induced Hypotension

BACKGROUND: Intravenous fluids and vasopressor agents are commonly used in early resuscitation of patients with sepsis, but comparative data for prioritizing their delivery are limited. METHODS: In an unblinded superiority trial conducted at 60 U.S. centers, we randomly assigned patients to either a restrictive fluid strategy (prioritizing vasopressors and lower intravenous fluid volumes) or a liberal fluid strategy (prioritizing higher volumes of intravenous fluids before vasopressor use) for a 24-hour period. Randomization occurred within 4 hours after a patient met the criteria for sepsis-induced hypotension refractory to initial treatment with 1 to 3 liters of intravenous fluid. We hypothesized that all-cause mortality before discharge home by day 90 (primary outcome) would be lower with a restrictive fluid strategy than with a liberal fluid strategy. Safety was also assessed. RESULTS: A total of 1563 patients were enrolled, with 782 assigned to the restrictive fluid group and 781 to the liberal fluid group. Resuscitation therapies that were administered during the 24-hour protocol period differed between the two groups; less intravenous fluid was administered in the restrictive fluid group than in the liberal fluid group (difference of medians, -2134 ml; 95% confidence interval [CI], -2318 to -1949), whereas the restrictive fluid group had earlier, more prevalent, and longer duration of vasopressor use. Death from any cause before discharge home by day 90 occurred in 109 patients (14.0%) in the restrictive fluid group and in 116 patients (14.9%) in the liberal fluid group (estimated difference, -0.9 percentage points; 95% CI, -4.4 to 2.6; P = 0.61); 5 patients in the restrictive fluid group and 4 patients in the liberal fluid group had their data censored (lost to follow-up). The number of reported serious adverse events was similar in the two groups. CONCLUSIONS: Among patients with sepsis-induced hypotension, the restrictive fluid strategy that was used in this trial did not result in significantly lower (or higher) mortality before discharge home by day 90 than the liberal fluid strategy. (Funded by the National Heart, Lung, and Blood Institute; CLOVERS ClinicalTrials.gov number, NCT03434028)

Black Holes in the Early Universe

The existence of massive black holes was postulated in the sixties, when the first quasars were discovered. In the late nineties their reality was proven beyond doubt, in the Milky way and a handful nearby galaxies. Since then, enormous theoretical and observational efforts have been made to understand the astrophysics of massive black holes. We have discovered that some of the most massive black holes known, weighing billions of solar masses, powered luminous quasars within the first billion years of the Universe. The first massive black holes must therefore have formed around the time the first stars and galaxies formed. Dynamical evidence also indicates that black holes with masses of millions to billions of solar masses ordinarily dwell in the centers of today's galaxies. Massive black holes populate galaxy centers today, and shone as quasars in the past; the quiescent black holes that we detect now in nearby bulges are the dormant remnants of this fiery past. In this review we report on basic, but critical, questions regarding the cosmological significance of massive black holes. What physical mechanisms lead to the formation of the first massive black holes? How massive were the initial massive black hole seeds? When and where did they form? How is the growth of black holes linked to that of their host galaxy? Answers to most of these questions are work in progress, in the spirit of these Reports on Progress in Physics.Comment: Reports on Progress in Physics, in pres

The 2009 multiwavelength campaign on Mrk 421: Variability and correlation studies

We performed a 4.5-month multi-instrument campaign (from radio to VHE gamma rays) on Mrk421 between January 2009 and June 2009, which included VLBA, F-GAMMA, GASP-WEBT, Swift, RXTE, Fermi-LAT, MAGIC, and Whipple, among other instruments and collaborations. Mrk421 was found in its typical (non-flaring) activity state, with a VHE flux of about half that of the Crab Nebula, yet the light curves show significant variability at all wavelengths, the highest variability being in the X-rays. We determined the power spectral densities (PSD) at most wavelengths and found that all PSDs can be described by power-laws without a break, and with indices consistent with pink/red-noise behavior. We observed a harder-when-brighter behavior in the X-ray spectra and measured a positive correlation between VHE and X-ray fluxes with zero time lag. Such characteristics have been reported many times during flaring activity, but here they are reported for the first time in the non-flaring state. We also observed an overall anti-correlation between optical/UV and X-rays extending over the duration of the campaign. The harder-when-brighter behavior in the X-ray spectra and the measured positive X-ray/VHE correlation during the 2009 multi-wavelength campaign suggests that the physical processes dominating the emission during non-flaring states have similarities with those occurring during flaring activity. In particular, this observation supports leptonic scenarios as being responsible for the emission of Mrk421 during non-flaring activity. Such a temporally extended X-ray/VHE correlation is not driven by any single flaring event, and hence is difficult to explain within the standard hadronic scenarios. The highest variability is observed in the X-ray band, which, within the one-zone synchrotron self-Compton scenario, indicates that the electron energy distribution is most variable at the highest energies.Comment: Accepted for publication in A&A, 18 pages, 14 figures (v2 has a small modification in the acknowledgments, and also corrects a typo in the field "author" in the metadata