Summary
Pre‐operative anaemia in patients undergoing major surgical procedures has been linked to poor outcomes. Therefore, early detection and treatment of pre‐operative anaemia is recommended. ...However, to effectively implement a pre‐operative anaemia management protocol, an estimation of its prevalence and main causes is needed. We analysed data from 3342 patients (44.5% female) scheduled for either: elective orthopaedic surgery (n = 1286); cardiac surgery (n = 691); colorectal cancer resection (n = 735); radical prostatectomy (n = 362); gynaecological surgery (n = 203) or resection of liver metastases (n = 122). For both sexes, anaemia was defined by a haemoglobin level < 130 g.l−1; absolute iron deficiency by ferritin < 30 ng.ml−1 (< 100 ng.ml−1, if transferrin saturation < 20% or C‐reactive protein > 5 mg.l−1); iron sequestration by transferrin saturation < 20% and ferritin > 100 ng.ml−1; and low iron stores by transferrin saturation > 20% and ferritin 30–100 ng.ml−1. The overall prevalence of anaemia was 36%, with differences according to the type of surgery. Laboratory parameters allowing classification of iron status were available for 2884 patients. Among those with anaemia (n = 986), 677 (69%) were women, 608 (62%) presented with absolute iron deficiency, 101 (10%) with iron sequestration; and 150 (5%) with low iron stores. Iron status alterations were similar in women with haemoglobin < 130 g.l−1 or < 120 g.l−1. For those who were not anaemic (n = 1898), corresponding figures were 656 (35%), 621 (33%), 165 (9%) and 518 (27%), respectively. Anaemia was present in one‐third of patients undergoing major elective procedures. Over two‐thirds of anaemic patients presented with absolute iron deficiency or iron sequestration. Over half of non‐anaemic patients presented with absolute iron deficiency or low iron stores. We consider these data useful for planning pre‐operative management of patients scheduled for major elective surgery.
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We compared the effects of two resistance training (RT) programs only differing in the repetition velocity loss allowed in each set: 20% (VL20) vs 40% (VL40) on muscle structural and functional ...adaptations. Twenty‐two young males were randomly assigned to a VL20 (n = 12) or VL40 (n = 10) group. Subjects followed an 8‐week velocity‐based RT program using the squat exercise while monitoring repetition velocity. Pre‐ and post‐training assessments included: magnetic resonance imaging, vastus lateralis biopsies for muscle cross‐sectional area (CSA) and fiber type analyses, one‐repetition maximum strength and full load‐velocity squat profile, countermovement jump (CMJ), and 20‐m sprint running. VL20 resulted in similar squat strength gains than VL40 and greater improvements in CMJ (9.5% vs 3.5%, P < 0.05), despite VL20 performing 40% fewer repetitions. Although both groups increased mean fiber CSA and whole quadriceps muscle volume, VL40 training elicited a greater hypertrophy of vastus lateralis and intermedius than VL20. Training resulted in a reduction of myosin heavy chain IIX percentage in VL40, whereas it was preserved in VL20. In conclusion, the progressive accumulation of muscle fatigue as indicated by a more pronounced repetition velocity loss appears as an important variable in the configuration of the resistance exercise stimulus as it influences functional and structural neuromuscular adaptations.
ABSTRACT
We present two transits of the hot‐Jupiter exoplanet XO‐2b using the Gran Telescopio Canarias (GTC). The time series observations were performed using long‐slit spectroscopy of XO‐2 and a ...nearby reference star with the Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) instrument, enabling differential spectrophotometric transit light curves capable of measuring the exoplanet's transmission spectrum. Two optical low‐resolution grisms were used to cover the optical wavelength range from 3800 to 9300 Å. We find that sub‐mmag‐level slit losses between the target and reference star prevent full optical transmission spectra from being constructed, limiting our analysis to differential absorption depths over ∼1000 Å regions. Wider long slits or multi‐object grism spectroscopy with wide masks will likely prove effective in minimizing the observed slit‐loss trends. During both transits, we detect significant absorption in the planetary atmosphere of XO‐2b using a 50‐Å bandpass centred on the Na i doublet, with absorption depths of Δ(Rpl/R★)2 = 0.049 ± 0.017 per cent using the R500R grism and 0.047 ± 0.011 per cent using the R500B grism (combined 5.2σ significance from both transits). The sodium feature is unresolved in our low‐resolution spectra, with detailed modelling also likely ruling out significant line‐wing absorption over an ∼800 Å region surrounding the doublet. Combined with narrow‐band photometric measurements, XO‐2b is the first hot Jupiter with evidence for both sodium and potassium present in the planet's atmosphere.
The restricted area of space used by most mobile animals is thought to result from fitness‐rewarding decisions derived from gaining information about the environment. Yet, assessments of how animals ...deal with uncertainty using memory have been largely theoretical, and an empirically derived mechanism explaining restricted space use in animals is still lacking. Using a patch‐to‐patch movement analysis, we investigated predictions of how free‐ranging bison (Bison bison) living in a meadow‐forest matrix use memory to reduce uncertainty in energy intake rate. Results indicate that bison remembered pertinent information about location and quality of meadows, and they used this information to selectively move to meadows of higher profitability. Moreover, bison chose profitable meadows they had previously visited, and this choice was stronger after visiting a relatively poor quality meadow. Our work demonstrates a link between memory, energy gains and restricted space use while establishing a fitness‐based integration of movement, cognitive and spatial ecology.
Astronomical wide-field imaging of interferometric radio data is computationally expensive, especially for the large data volumes created by modern non-coplanar many-element arrays. We present a new ...wide-field interferometric imager that uses the w-stacking algorithm and can make use of the w-snapshot algorithm. The performance dependences of casa's w-projection and our new imager are analysed and analytical functions are derived that describe the required computing cost for both imagers. On data from the Murchison Widefield Array, we find our new method to be an order of magnitude faster than w-projection, as well as being capable of full-sky imaging at full resolution and with correct polarization correction. We predict the computing costs for several other arrays and estimate that our imager is a factor of 2–12 faster, depending on the array configuration. We estimate the computing cost for imaging the low-frequency Square Kilometre Array observations to be 60 PetaFLOPS with current techniques. We find that combining w-stacking with the w-snapshot algorithm does not significantly improve computing requirements over pure w-stacking. The source code of our new imager is publicly released.
We analyze Spitzer images of 30 long-duration gamma-ray burst (GRB) host galaxies. We estimate their total stellar masses (M{sub *}) based on the rest-frame K-band luminosities (L{sub K{sub r{sub ...e{sub s{sub t}}}) and constrain their star formation rates (SFRs; not corrected for dust extinction) based on the rest-frame UV continua. Further, we compute a mean M{sub *}/L{sub K{sub r{sub e{sub s{sub t}}} = 0.45 M{sub sun}/L{sub sun}. We find that the hosts are low M{sub *}, star-forming systems. The median M{sub *} in our sample ((M{sub *}) = 10{sup 9.7} M{sub sun}) is lower than that of 'field' galaxies (e.g., Gemini Deep Deep Survey). The range spanned by M{sub *} is 10{sup 7} M{sub sun} < M{sub *} < 10{sup 11} M{sub sun}, while the range spanned by the dust-uncorrected UV SFR is 10{sup -2} M{sub sun} yr{sup -1} < SFR < 10 M{sub sun} yr{sup -1}. There is no evidence for intrinsic evolution in the distribution of M{sub *} with redshift. We show that extinction by dust must be present in at least 25% of the GRB hosts in our sample and suggest that this is a way to reconcile our finding of a relatively lower UV-based, specific SFR ({phi} {identical_to} SFR/M{sub *}) with previous claims that GRBs have some of the highest {phi} values. We also examine the effect that the inability to resolve the star-forming regions in the hosts has on {phi}.
Microalgae have been proposed as an option for wastewater treatment since the 1960s, but still, this technology has not been expanded to an industrial scale. In this paper, the major factors limiting ...the performance of these systems are analysed. The composition of the wastewater is highly relevant, and especially the presence of pollutants such as heavy metals and emerging compounds. Biological and engineering aspects are also critical and have to be improved to at least approximate the performance of conventional systems, not just in terms of capacity and efficiency but also in terms of robustness. Finally, the harvesting of the biomass and its processing into valuable products pose a challenge; yet at the same time, an opportunity exists to increase economic profitability. Land requirement is a major bottleneck that can be ameliorated by improving the system’s photosynthetic efficiency. Land requirement has a significant impact on the economic balance, but the profits from the biomass produced can enhance these systems’ reliability, especially in small cities.
Barnard's star is a red dwarf, and has the largest proper motion (apparent motion across the sky) of all known stars. At a distance of 1.8 parsecs
, it is the closest single star to the Sun; only the ...three stars in the α Centauri system are closer. Barnard's star is also among the least magnetically active red dwarfs known
and has an estimated age older than the Solar System. Its properties make it a prime target for planetary searches; various techniques with different sensitivity limits have been used previously, including radial-velocity imaging
, astrometry
and direct imaging
, but all ultimately led to negative or null results. Here we combine numerous measurements from high-precision radial-velocity instruments, revealing the presence of a low-amplitude periodic signal with a period of 233 days. Independent photometric and spectroscopic monitoring, as well as an analysis of instrumental systematic effects, suggest that this signal is best explained as arising from a planetary companion. The candidate planet around Barnard's star is a cold super-Earth, with a minimum mass of 3.2 times that of Earth, orbiting near its snow line (the minimum distance from the star at which volatile compounds could condense). The combination of all radial-velocity datasets spanning 20 years of measurements additionally reveals a long-term modulation that could arise from a stellar magnetic-activity cycle or from a more distant planetary object. Because of its proximity to the Sun, the candidate planet has a maximum angular separation of 220 milliarcseconds from Barnard's star, making it an excellent target for direct imaging and astrometric observations in the future.
We present Gran Telescopio Canarias (GTC) optical transit narrowband photometry of the hot-Jupiter exoplanet XO-2b using the OSIRIS instrument. This unique instrument has the capabilities to deliver ...high-cadence narrowband photometric lightcurves, allowing us to probe the atmospheric composition of hot Jupiters from the ground. The observations were taken during three transit events that cover four wavelengths at spectral resolutions near 500, necessary for observing atmospheric features, and have near-photon limited sub-mmag precisions. Precision narrowband photometry on a large aperture telescope allows for atmospheric transmission spectral features to be observed for exoplanets around much fainter stars than those of the well studied targets HD 209458b and HD 189733b, providing access to the majority of known transiting planets. For XO-2b, we measure planet-to-star radius contrasts of Rpl/R⋆ = 0.10508 ± 0.00052 at 6792 Å, 0.10640 ± 0.00058 at 7582 Å, and 0.10686 ± 0.00060 at 7664.9 Å, and 0.10362 ± 0.00051 at 8839 Å. These measurements reveal significant spectral features at two wavelengths, with an absorption level of 0.067 ± 0.016% at 7664.9 Å caused by atmospheric potassium in the line core (a 4.1-σ significance level), and an absorption level of 0.058 ± 0.016% at 7582 Å, (a 3.6-σ significance level). When comparing our measurements to hot-Jupiter atmospheric models, we find good agreement with models that are dominated in the optical by alkali metals. This is the first evidence for potassium in an extrasolar planet, an element that has along with sodium long been supposed to be a dominant source of opacity at optical wavelengths for hot Jupiters.
A previous trial in renal transplantation comparing sirolimus (rapamycin) to cyclosporine (CsA) in a triple-drug therapy regimen with azathioprine and corticosteroids found that the incidence of ...acute rejection was similar (approximately 40%) with a trend for better renal function with sirolimus.
In 14 European centers, first cadaveric renal allograft recipients were randomized to receive sirolimus (n = 40) or CsA (n = 38) in an open-label design. All patients received corticosteroids and mycophenolate mofetil 2 g/day. Sirolimus and CsA were concentration controlled; trough levels of mycophenolic acid and prednisolone were also measured.
At 12 months, graft survival (92.5% sirolimus vs. 89.5% CsA), patient survival (97.5% sirolimus vs. 94.7% CsA), and the incidence of biopsy-proven acute rejection (27.5% sirolimus vs. 18.4% CsA) were not statistically different. The use of antibodies to treat suspected rejection episodes was also similar (7.5% sirolimus vs. 5.3% CsA). More sirolimus patients received bolus steroid therapy (20 vs. 11, P = 0.068). From month 2 onward, the calculated glomerular filtration rate was consistently higher in sirolimus-treated patients. The adverse events reported more frequently with sirolimus were thrombocytopenia (45% vs. 8%) and diarrhea (38% vs. 11%). In the CsA group, increased creatinine (18% vs. 39%), hyperuricemia (3% vs. 18%), cytomegalovirus infection (5% vs. 21%), and tremor (5% vs. 21%) were observed significantly more often.
Patient and graft survival and the incidence of biopsy-proven acute rejection at 12 months were comparable between sirolimus and CsA, whereas safety profiles were different. These data suggest that sirolimus may be used as primary therapy for the prevention of acute rejection.
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