Recently published papers: A review of novel strategies in the prevention of hospital-acquired infections, the ability of intensivists to perform echocardiography, and the benefit of polymyxin B haemoperfusion in abdominal sepsis

Chlorhexidine bed baths seem to reduce the incidence of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus detected by surveillance cultures. There is also some evidence on the benefit of chlorhexidine mouthwashes in the prevention of ventilator-associated pneumonias. Acid-suppressing drugs increase the incidence of hospital-acquired pneumonias in non-intensive care unit patients, although this association has not been shown in the intensive care setting. Intensivists can be trained to perform basic echocardiography in a short period of time, but their errors could lead to incorrect changes in management. Polymyxin B haemoperfusion was shown in interim analysis to improve patients with abdominal sepsis to such an extent that the EUPHAS randomised controlled trial was halted on ethical grounds, although other authors have criticised this decision

Estimation of multi-state life table functions and their variability from complex survey data using the SPACE Program

The multistate life table (MSLT) model is an important demographic method to document life cycle processes. In this study, we present the SPACE (Stochastic Population Analysis for Complex Events) program to estimate MSLT functions and their sampling variability. It has several advantages over other programs, including the use of microsimulation and the bootstrap method to estimate the sampling variability. Simulation enables researchers to analyze a broader array of statistics than the deterministic approach, and may be especially advantageous in investigating distributions of MSLT functions. The bootstrap method takes sample design into account to correct the potential bias in variance estimates.bootstrap, health expectancy, multi-state life table, population aging

Nocturnal Copulation in Glaucous-winged Gulls Larus glaucescens

Gulls (Laridae) are primarily diurnal, although many species forage opportunistically at night, and several species copulate at night. We used trail cameras to study time-of-day variation in the rate of copulation by Glaucous-winged Gulls Larus glaucescens in a breeding colony (1500+ pairs) at Protection Island, Washington, USA, from 31 May to 07 June 2018. Copulations (n = 353) occurred at a significantly higher rate during the day (0.82/camera-h) than at night (0.51/camera-h), with 76.3 % of copulations during the day and 23.7 % at night (daylight comprised 66.1 % and darkness comprised 33.9 % of the study period). The copulation rate peaked shortly before and after dawn, with a second peak before sunset. Copulation rate was lowest during the middle of the day and middle of the night. Glaucous-winged Gulls sleep intermittently during both day and night and have sufficient energy to sustain sporadic copulations during the night, which appears to be a normal part of their reproductive behavior. The most likely advantage of this pattern is an increased opportunity for fertilization with a mate

Professional Reading

The Superwarriors—the Fantastic World of Pentagon Superweapon

Determining the stellar masses of submillimetre galaxies: the critical importance of star formation histories

Submillimetre (submm) galaxies are among the most rapidly star-forming and most massive high-redshift galaxies; thus, their properties provide important constraints on galaxy evolution models. However, there is still a debate about their stellar masses and their nature in the context of the general galaxy population. To test the reliability of their stellar mass determinations, we used a sample of simulated submm galaxies for which we derived stellar masses via spectral energy distribution (SED) modelling (with Grasil, Magphys, Hyperz and LePhare) adopting various star formation histories (SFHs). We found that the assumption of SFHs with two independent components leads to the most accurate stellar masses. Exponentially declining SFHs (tau) lead to lower masses (albeit still consistent with the true values), while the assumption of single-burst SFHs results in a significant mass underestimation. Thus, we conclude that studies based on the higher masses inferred from fitting the SEDs of real submm galaxies with double SFHs are most likely to be correct, implying that submm galaxies lie on the high-mass end of the main sequence of star-forming galaxies. This conclusion appears robust to assumptions of whether or not submm galaxies are driven by major mergers, since the suite of simulated galaxies modelled here contains examples of both merging and isolated galaxies. We identified discrepancies between the true and inferred stellar ages (rather than the dust attenuation) as the primary determinant of the success/failure of the mass recovery. Regardless of the choice of SFH, the SED-derived stellar masses exhibit a factor of ~2 scatter around the true value; this scatter is an inherent limitation of the SED modelling due to simplified assumptions. Finally, we found that the contribution of active galactic nuclei does not have any significant impact on the derived stellar masses.Comment: Accepted to A&A. 11 pages, 9 figures, 1 table. V2 main changes: 1) discussion of the stellar age as the main parameter influencing the success of an SED model (Fig. 4, 5, 7); 2) discussion of the age-dust degeneracy (Fig 9); 3) the comparison of real and simulated submm galaxies (Fig 1

Feeding Interactions Between Juvenile and Adult Flightless Cormorants.

We report observations on chick feedings by adult Flightless Cormorants Phalacrocorax harrisi, indicating that, contrary to the literature, the sequence of interaction is similar to that of other Pelecaniformes

An Assessment of Computational Methods for Calculating Accurate Structures and Energies of Bio-Relevant Polysulfur/Selenium-Containing Compounds

The heavier chalcogens sulfur and selenium are important in organic and inorganic chemistry, and the role of such chalcogens in biological systems has recently gained more attention. Sulfur and, to a lesser extent selenium, are involved in diverse reactions from redox signaling to antioxidant activity and are considered essential nutrients. We investigated the ability of the DFT functionals (B3LYP, B3PW91, ωB97XD, M06-2X, and M08-HX) relative to electron correlation methods MP2 and QCISD to produce reliable and accurate structures as well as thermochemical data for sulfur/selenium-containing systems. Bond lengths, proton affinities (PA), gas phase basicities (GPB), chalcogen–chalcogen bond dissociation enthalpies (BDE), and the hydrogen affinities (HA) of thiyl/selenyl radicals were evaluated for a range of small polysulfur/selenium compounds and cysteine per/polysulfide. The S–S bond length was found to be the most sensitive to basis set choice, while the geometry of selenium-containing compounds was less sensitive to basis set. In mixed chalcogens species of sulfur and selenium, the location of the sulfur atom affects the S–Se bond length as it can hold more negative charge. PA, GPB, BDE, and HA of selenium systems were all lower, indicating more acidity and more stability of radicals. Extending the sulfur chain in cysteine results in a decrease of BDE and HA, but these plateau at a certain point (199 kJ mol−1 and 295 kJ mol−1), and PA and GPB are also decreased relative to the thiol, indicating that the polysulfur species exist as thiolates in a biological system. In general, it was found that ωB97XD/6-311G(2d,p) gave the most reasonable structures and thermochemistry relative to benchmark calculations. However, nuances in performance are observed and discussed