Clear as daylight: analysis of diurnal raptor pellets for small mammal studies

Non–invasive approaches are increasingly investigated and applied in studies of small mammal assemblages because they are more cost–effective and bypass conservation and animal welfare issues. However, pellets of diurnal raptors have rarely been used for these purposes. We evaluated the potential of marsh harrier pellets (Circus aeruginosus) as a non–invasive method to sample small mammal assemblages, by comparing the results with those of sampling using Sherman live–traps and pitfalls. The three methods were applied simultaneously in an agricultural–wetland complex in NW Portugal. Estimates of species richness, diversity, evenness, abundance, and proportion of each species within the assemblage showed significant differences between the three methods. Our results suggest that the use of marsh harrier pellets is more effective in inventorying small mammal species than either of the two kinds of traps, while also avoiding any involuntary fatalities associated with the sampling of small non–volant mammals. Moreover, the analysis of pellets was the most cost–effective method. Comparison of the two trapping methodologies showed involuntary fatalities were higher in pitfalls than in Sherman traps. We discuss the advantages and flaws of the three methods, both from technical and conservational perspectives.

Organocatalytic synthesis of bio-based cyclic carbonates from CO2 and vegetable oils

Optimal conditions deduced from in situ FTIR kinetic studies provide quantitative conversion of epoxidized linseed oil into carbonated linseed oil using a bi-component organocatalyst.

Organocatalytic promoted coupling of carbon dioxide with epoxides: a rational investigation of the cocatalytic activity of various hydrogen bond donors

A rational investigation of the cocatalytic activity of a series of commercially available hydrogen bond donors (HBDs) for the synthesis of cyclic carbonates from CO₂ and epoxides under mild conditions.

Peripheral microcirculatory exploration during mechanical ventilation weaning

BACKGROUND

Weaning from mechanical ventilation is a daily challenge in intensive care patients. Our objective was to explore microcirculatory perfusion during mechanical ventilation weaning and to evaluate its predictive value on the weaning outcome.

METHODS

Prospective observational study. All consecutive patients, older than 18 years, under mechanical ventilation that met the criteria for weaning were enrolled. Patients underwent a T-piece Spontaneous Breath Trial (SBT) for 60 minutes and the usual clinical parameters were recorded every 5 minutes. Microcirculatory perfusion was evaluated using the mottling score and the Tissue Oxygen Saturation (StO2) measured by Near Infrared Spectroscopy technology on the thenar and knee area.

RESULTS

Seventy-three patients were studied (age: 67±15 years, men: 40, SAPS II: 47±15) after a duration of mechanical ventilation of 3 (1-6) days. Forty-five patients succeeded the first SBT. The mottling score severity recorded just before ventilator disconnection (baseline) was associated with weaning failure (P=0.03). Moreover, the mottling score increase during SBT was significantly associated with weaning failure (80% vs. 28%, P=0.001; Odds ratio 10.5 [2.0-54.8]). Baseline thenar StO2 was not different according to weaning outcome (failure 76±13% vs. success 77±7%, P=0.90) whereas baseline knee StO2 was significantly lower in patients who failed the first SBT (67±13% vs. 75±12%, P<0.01). This difference was apparent since the very beginning of the SBT and lasted throughout the trial (P=0.0001).

CONCLUSION

In unselected mechanically ventilated patients undergoing SBT, mottling score and knee StO2 are early predictors of weaning failure.

High inborn aerobic capacity does not protect the heart following myocardial infarction

Maximal oxygen uptake (Vo2max) is a strong prognostic marker for morbidity and mortality, but the cardio-protective effect of high inborn Vo2max remains unresolved. We aimed to investigate whether rats with high inborn Vo2max yield cardio-protection after myocardial infarction (MI) compared with rats with low inborn Vo2max. Rats breed for high capacity of running (HCR) or low capacity of running (LCR) were randomized into HCR-SH (sham), HCR-MI, LCR-SH, and LCR-MI. Vo2max was lower in HCR-MI and LCR-MI compared with respective sham (P < 0.01), supported by a loss in global cardiac function, assessed by echocardiography. Fura 2-AM loaded cardiomyocyte experiments revealed that HCR-MI and LCR-MI decreased cardiomyocyte shortening (39%, and 34% reduction, respectively, both P < 0.01), lowered Ca(2+) transient amplitude (37%, P < 0.01, and 20% reduction, respectively), and reduced sarcoplasmic reticulum (SR) Ca(2+) content (both; 20%, P < 0.01) compared with respective sham. Diastolic Ca(2+) cycling was impaired in HCR-MI and LCR-MI evidenced by prolonged time to 50% Ca(2+) decay that was partly explained by the 47% (P < 0.01) and 44% (P < 0.05) decrease in SR Ca(2+)-ATPase Ca(2+) removal, respectively. SR Ca(2+) leak increased by 177% in HCR-MI (P < 0.01) and 67% in LCR-MI (P < 0.01), which was abolished by inhibition of Ca(2+)/calmodulin-dependent protein kinase II. This study demonstrates that the effect of MI in HCR rats was similar or even more pronounced on cardiac- and cardiomyocyte contractile function, as well as on Ca(2+) handling properties compared with observations in LCR. Thus our data do not support a cardio-protective effect of higher inborn aerobic capacity.