Systemic inflammation is pivotal in the pathogenesis of cardiovascular disease. As inflammation can directly cause cardiomyocyte injury, we hypothesised that established systemic inflammation, as ...reflected by elevated preoperative neutrophil-lymphocyte ratio (NLR) >4, predisposes patients to perioperative myocardial injury.
We prospectively recruited 1652 patients aged ≥45 yr who underwent non-cardiac surgery in two UK centres. Serum high sensitivity troponin T (hsTnT) concentrations were measured on the first three postoperative days. Clinicians and investigators were blinded to the troponin results. The primary outcome was perioperative myocardial injury, defined as hsTnT≥14 ng L−1 within 3 days after surgery. We assessed whether myocardial injury was associated with preoperative NLR>4, activated reactive oxygen species (ROS) generation in circulating monocytes, or both. Multivariable logistic regression analysis explored associations between age, sex, NLR, Revised Cardiac Risk Index, individual leukocyte subsets, and myocardial injury. Flow cytometric quantification of ROS was done in 21 patients. Data are presented as n (%) or odds ratio (OR) with 95% confidence intervals.
Preoperative NLR>4 was present in 239/1652 (14.5%) patients. Myocardial injury occurred in 405/1652 (24.5%) patients and was more common in patients with preoperative NLR>4 OR: 2.56 (1.92–3.41); P<0.0001. Myocardial injury was independently associated with lower absolute preoperative lymphocyte count OR 1.80 (1.50–2.17); P<0.0001 and higher absolute preoperative monocyte count OR 1.93 (1.12–3.30); P=0.017. Monocyte ROS generation correlated with NLR (r=0.47; P=0.03).
Preoperative NLR>4 is associated with perioperative myocardial injury, independent of conventional risk factors. Systemic inflammation may contribute to the development of perioperative myocardial injury.
NCT01842568.
Protected areas are traditionally the foundation of conservation strategy, but land not formally protected is of particular importance for the conservation of large carnivores because of their ...typically wide-ranging nature. In South Africa, leopard (Panthera pardus) population decreases are thought to be occurring in areas of human development and intense negative interactions, but research is biased towards protected areas, with quantitative information on population sizes and trends in non-protected areas severely lacking. Using Spatially Explicit Capture-Recapture and occupancy techniques including 10 environmental and anthropogenic covariates, we analysed camera trap data from commercial farmland in South Africa where negative human-wildlife interactions are reported to be high. Our findings demonstrate that leopards persist at a moderate density (2.21 /100 km
) and exhibit signs of avoidance from areas where lethal control measures are implemented. This suggests leopards have the potential to navigate mixed mosaic landscapes effectively, enhancing their chances of long-term survival and coexistence with humans. Mixed mosaics of agriculture that include crops, game and livestock farming should be encouraged and, providing lethal control is not ubiquitous in the landscape, chains of safer spaces should permit vital landscape connectivity. However, continuing to promote non-lethal mitigation techniques remains vital.
The Fermi-LAT experiment recently reported high precision measurements of the spectrum of cosmic-ray electrons-plus-positrons (CRE) between 20
GeV and 1
TeV. The spectrum shows no prominent spectral ...features, and is significantly harder than that inferred from several previous experiments. Here we discuss several interpretations of the Fermi results based either on a single large scale Galactic CRE component or by invoking additional electron–positron primary sources, e.g. nearby pulsars or particle dark matter annihilation. We show that while the reported Fermi-LAT data alone can be interpreted in terms of a single component scenario, when combined with other complementary experimental results, specifically the CRE spectrum measured by H.E.S.S. and especially the positron fraction reported by PAMELA between 1 and 100
GeV, that class of models fails to provide a consistent interpretation. Rather, we find that several combinations of parameters, involving both the pulsar and dark matter scenarios, allow a consistent description of those results. We also briefly discuss the possibility of discriminating between the pulsar and dark matter interpretations by looking for a possible anisotropy in the CRE flux.
Fluorescence in biological systems is usually associated with the presence of aromatic groups. Here, by employing a combined experimental and computational approach, we show that specific hydrogen ...bond networks can significantly affect fluorescence. In particular, we reveal that the single amino acid L-glutamine, by undergoing a chemical transformation leading to the formation of a short hydrogen bond, displays optical properties that are significantly enhanced compared with L-glutamine itself. Ab initio molecular dynamics simulations highlight that these short hydrogen bonds prevent the appearance of a conical intersection between the excited and the ground states and thereby significantly decrease nonradiative transition probabilities. Our findings open the door to the design of new photoactive materials with biophotonic applications.
Bacteriophages are natural predators of bacteria and may mitigate Escherichia coli O157:H7 in cattle and their environment. As bacteriophages targeted to E. coli O157:H7 (phages) lose activity at low ...pH, protection from gastric acidity may enhance efficacy of orally administered phages. Polymer encapsulation of four phages, wV8, rV5, wV7, and wV11, and exposure to pH 3.0 for 20 min resulted in an average 13.6% recovery of phages after release from encapsulation at pH 7.2. In contrast, untreated phages under similar conditions had a complete loss of activity. Steers (n = 24) received 10(11) CFU of naladixic acid-resistant E. coli O157:H7 on day 0 and were housed in six pens of four steers. Two pens were control (naladixic acid-resistant E. coli O157:H7 only), and the remaining pens received polymer-encapsulated phages (Ephage) on days -1, 1, 3, 6, and 8. Two pens received Ephage orally in gelatin capsules (bolus; 10(10) PFU per steer per day), and the remaining two pens received Ephage top-dressed on their feed (feed; estimated 10(11) PFU per steer per day). Shedding of E. coli O157:H7 was monitored for 10 weeks by collecting fecal grab and hide swab samples. Acceptable activity of mixed phages at delivery to steers was found for bolus and feed, averaging 1.82 and 1.13 x 10(9) PFU/g, respectively. However, Ephage did not reduce shedding of naladixic acid-resistant E. coli O157:H7, although duration of shedding was reduced by 14 days (P < 0.1) in bolus-fed steers as compared with control steers. Two successful systems for delivery of Ephage were developed, but a better understanding of phage-E. coli O157:H7 ecology is required to make phage therapy a viable strategy for mitigation of this organism in feedlot cattle.
Mesocarnivores are of particular interest in wildlife management. Their adaptability makes them a focus of public attention globally, as negative interactions with people occur regularly, but their ...importance to wider ecosystem function is increasingly apparent. Robust methods for estimating mesocarnivore densities are essential for long‐term management strategies. Estimating densities of unmarked populations remains challenging, but new methods, based on camera trapping, have recently become available and require field testing.
We conducted two camera trap surveys over two 200 km2 areas of commercial farmland in South Africa. One survey sampled 25 locations, while the second used a migrating grid to sample 59 locations; total sampling effort was similar across the two surveys. We applied distance sampling with camera traps (CTDS), developing a method to estimate animal distances by applying a distance measurement overlay grid to camera trap images.
We aimed to establish meaningful density estimates of the mesocarnivore guild and evaluate CTDS's suitability for broader use with these types of species. We obtained density estimates for four carnivores, African civet Civettictis civetta, black‐backed jackal Canis mesomelas, brown hyena Hyaena brunnea and caracal Caracal caracal, providing valuable insight into their status in commercial farmland. Imprecision in the estimates was almost exclusively due to encounter rate variance, which was not reduced with the migrating camera grid.
We explored the sensitivity of our results to assumptions determining the value of the ‘snapshot interval’, demonstrating that careful selection of this parameter is vital to ensuring reliable estimates when using rapid‐fire photo burst modes.
CTDS can provide useful density estimates for mesocarnivores, but future studies should aim to maximize precision and reliability by increasing sampling locations. More studies are required in areas with known densities to promote confidence in accuracy.
Abstrak
Mesokarnivore is van besondere belang in wildbestuur. Hul aanpasbaarheid maak hulle wêreldwyd ‘n fokus van publieke aandag, aangesien negatiewe interaksies met mense gereeld voorkom, maar hul belangrikheid vir wyer ekosisteemfunksie word toenemend duidelik. Robuuste metodes om mesokarnivoor digthede te skat is noodsaaklik vir langtermyn bestuur strategieë. Die skatting van digthede van ongemerkte bevolkings bly uitdagend, maar nuwe metodes, gebaseer op kamera lokvalle, het onlangs beskikbaar geword en vereis verdere ondersoek.
Ons het twee kamera‐lokval opnames oor twee 200 km2 kommersiële landbougrond gebiede in Suid‐Afrika gedoen. Een opname het 25 liggings met ‘n stilstaande installasie ondersoek, en die tweede het ‘n migrerende rooster gebruik om steekproewe in 59 liggings te doen; totale steekproef pogings was soortgelyk oor die twee opnames. Ons het afstand steekproefneming met kamera lokvalle (CTDS) toegepas, en ‘n metode ontwikkel om diere se afstande vanaf die kamera te skat deur ‘n afstand‐meting oorleg‐rooster op kamera lokval foto's aan te bring.
Ons het ten doel gehad om betekenisvolle digtheid skattings van die mesokarnivoor gilde vas te stel en kamera lokvalle se geskiktheid vir breër gebruik met hierdie tipe spesies te evalueer. Ons het digtheidskattings verkry vir vier karnivore, Afrika sivetkat (Civettictis civetta), swartrug jakkals (Canis mesomelas), bruin hiëna (Hyaena brunnea) en rooikat (Caracal caracal), wat waardevolle insig aangaande hul status op kommersiële landbougrond bied. Onakkuraatheid in die skattings was byna uitsluitlik te wyte aan ontmoetings tempo‐afwykings, wat nie verminder is met gebruik van die migrerende kamera‐rooster nie.
Ons het die sensitiwiteit van ons resultate teen aannames wat die waarde van die ‘kiekie‐interval’ bepaal, ondersoek, wat getoon het dat noukeurige keuse van hierdie verstelling noodsaaklik is om meer betroubare skattings te verseker wanneer vinnige‐vuur‐foto sarsie‐roetines gebruik word. CTDS kan nuttige digtheid skattings vir mesokarnivore verskaf, maar toekomstige studies moet daarop gemik wees om akkuraatheid en betroubaarheid te verbeter deur steekproef liggings te verhoog. Meer studies word vereis in gebiede met bekende digthede om betroubaarheid en akkuraatheid te bevorder.
We develop a method to estimate animal distances in camera trap images efficiently. By applying this distance overlay we show that distance sampling with camera traps estimates meaningful densities of mesocarnivores on farmland in South Africa.
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