The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

Near Infrared Spectroscopy for the detection of oxygenation and perfusion deficits in paediatric anaesthesia and surgery

Although near infrared spectroscopy (NIRS) has been available in the clinical environment for nearly twenty years, many questions still exist regarding it's utility and validity. This thesis explores tissue oxygenation monitoring using NIRS in three specific clinical scenarios, each exploring aspects of these issues. The first study focussed on the ability of muscle StO2 (tissue haemoglobin oxygen saturation) monitoring to detect clinically significant vascular compromise in paediatric patients with supracondylar fractures. Significantly lower StO2 values were observed in injured limbs with vascular compromise, which normalized following fracture reduction. The results suggest that muscle StO2 monitoring may be a useful addition to standard clinical means of assessing perfusion following paediatric supracondylar fractures. The second study used a juvenile porcine model of acute hepatic ischaemia to determine the potential utility of transcutaneous hepatic StO2 measurement, for use in the post-transplantation environment. Although a transcutaneous optical signal of ischaemia was detectable, its magnitude was too small for reliable clinical use, and was heavily influenced by animal size. These findings reinforced the concern in the literature regarding the depth of penetration of standard clinical StO2 monitors, and recommended against the use of somatic organ StO2 monitoring in patients of greater than 10kg. The third study was a multinational observational study of cerebral StO2 in infants and neonates undergoing general anaesthesia which found that severe cerebral desaturation during anaesthesia was uncommon. This is the largest observational study to date, and concluded that unrecognized severe desaturation lasting three minutes or longer in infants is too rare an event to explain subsequent development of neurocognitive abnormalities. These studies explore the potential utility of tissue StO2 monitoring in three distinct clinical scenarios. They each address a separate aspect of monitoring utility: agreement with clinical judgement, validity of measurements in new applications, and determination of normal values. Together, they highlight some of the challenges in the clinical use of medical diagnostic and monitoring technology. Tissue oxygenation monitoring utilizing near infrared spectroscopy has substantial potential clinical utility, but requires users to be aware of its basic principles of operation, and its technical limitations

Measurement of cardiac output during exercise in healthy, trained humans using lithium dilution and pulse contour analysis

The aim of this study was to evaluate the use of pulse contour analysis calibrated with lithium dilution in a single device (LiDCO™) for measurement of cardiac output ([Formula: see text]) during exercise in healthy volunteers. We sought to; (a) compare pulse contour analysis (PulseCO) and lithium indicator dilution (LiDCO) for the measurement of [Formula: see text] during exercise, and (b) assess the requirement for recalibration of PulseCO with LiDCO during exercise. Ten trained males performed multi-stage cycling exercise at intensities below and above ventilatory threshold before constant load maximal exercise to exhaustion. Uncalibrated PulseCO [Formula: see text] ([Formula: see text](raw)) was compared to that calibrated with lithium dilution at baseline ([Formula: see text](baseline)), during submaximal exercise below ([Formula: see text](low)) and above ([Formula: see text](high)) ventilatory threshold, and at each exercise stage individually ([Formula: see text](exercise)). There was a significant difference between [Formula: see text](baseline) and all other calibration methods during exercise, but not at rest. No significant differences were observed between other methods. Closest agreement with [Formula: see text](exercise) was observed for [Formula: see text](high) (bias ± limits of agreement: 4.8 ± 30.0%). The difference between [Formula: see text](exercise) and both [Formula: see text](low) and [Formula: see text](raw) was characterized by low bias (4-7%) and wide limits of agreement (>±40%). Calibration of pulse contour analysis with lithium dilution prior to exercise leads to a systematic overestimation of exercising cardiac output. A single calibration performed during exercise above the ventilatory threshold provided acceptable limits of agreement with an approach incorporating multiple calibrations throughout exercise. Pulse contour analysis may be used for [Formula: see text] measurement during exercise providing the system is calibrated during exercise

Exercising with reserve: evidence that the central nervous system regulates prolonged exercise performance

OBJECTIVE: The purpose of this study was to measure the effects of an amphetamine (methylphenidate) on exercise performance at a fixed rating of perceived exertion of 16. METHODS: Eight elite cyclists ingested 10 mg methylphenidate in a randomised, placebo-controlled crossover trial. RESULTS: Compared with placebo, subjects receiving methylphenidate cycled for approximately 32% longer before power output fell to 70% of the starting value. At the equivalent time at which the placebo trial terminated, subjects receiving methylphenidate had significantly higher power outputs, oxygen consumptions, heart rates, ventilatory volumes and blood lactate concentrations although electromyographic activity remained unchanged. The ingestion of a centrally acting stimulant thus allowed subjects to exercise for longer at higher cardiorespiratory and metabolic stress indicating the presence of a muscular reserve in the natural state. CONCLUSIONS: This suggests that endurance performance is not only "limited" by mechanical failure of the exercising muscles ("peripheral fatigue"). Rather performance during prolonged endurance exercise under normal conditions is highly regulated by the central nervous system to ensure that whole-body homeostasis is protected and an emergency reserve is always present