The effect of epidural anaesthesia on peripheral resistance and graft flow following femorodistal reconstruction

Objective:To determine the extent to which epidural anaesthesia influences peripheral resistance and graft blood flow following femorocrural reconstruction.Design:Prospective, controlled study measuring blood flow, arterial pressure and peripheral resistance in femorocrural bypass grafts for 20 min following onset of epidural anaesthesia with 15ml of 0.25% bupivacaine.Patients:Twenty patients undergoing femorocrural reconstruction for critical lower-limb ischaemia with in situ long saphenous vein, under general anaesthesia. Ten patients had epidural cannulae inserted preoperatively and injected with bupivacaine after completion of the graft.Results:Peripheral resistance fell in all 10 patients receiving epidural anaesthesia from a mean (range) of 1.07 PRU (0.32–2.2) to 0.49 PRU (0.19–0.72), compared to control values of 0.95 PRU (0.39–2.0) to 0.91 PRU (0.41–1.51; P < 0.01, Wilcoxon). There was a tendency for blood pressure to fall in the study patients (not significant) but graft blood flow still increased from 98 ml min−1 (41–221) to 160 ml min−1 (101–250), compared to flow in the control patients of 101 ml min−1 (45–176) at baseline to 104 ml min−1 (56–168; p < 0.01) at 20 min.Conclusions:Epidural anaesthesia significantly decreases peripheral resistance and increases graft blood flow in femorocrural grafts and would appear, therefore, to be of benefit for patients undergoing femorodistal reconstruction

Mapping material stocks of buildings and mobility infrastructure in the United Kingdom and the Republic of Ireland

Understanding the size and spatial distribution of material stocks is crucial for sustainable resource management and climate change mitigation. This study presents high-resolution maps of buildings and mobility infrastructure stocks for the United Kingdom (UK) and the Republic of Ireland (IRL) at 10 m, combining satellite-based Earth observations, OpenStreetMaps, and material intensities research. Stocks in the UK and IRL amount to 19.8 Gigatons or 279 tons/cap, predominantly aggregate, concrete and bricks, as well as various metals and timber. Building stocks per capita are surprisingly similar across medium to high population density, with only the lowest population densities having substantially larger per capita stocks. Infrastructure stocks per capita decrease with higher population density. Interestingly, for a given building stock within an area, infrastructure stocks are substantially larger in IRL than in the UK. These maps can provide useful insights for sustainable urban planning and advancing a circular economy

Using behavior-analytic implicit tests to assess sexual interests among normal and sex-offender populations

The development of implicit tests for measuring biases and behavioral predispositions is a recent development within psychology. While such tests are usually researched within a social-cognitive paradigm, behavioral researchers have also begun to view these tests as potential tests of conditioning histories, including in the sexual domain. The objective of this paper is to illustrate the utility of a behavioral approach to implicit testing and means by which implicit tests can be built to the standards of behavioral psychologists. Research findings illustrating the short history of implicit testing within the experimental analysis of behavior are reviewed. Relevant parallel and overlapping research findings from the field of social cognition and on the Implicit Association Test are also outlined. New preliminary data obtained with both normal and sex offender populations are described in order to illustrate how behavior-analytically conceived implicit tests may have potential as investigative tools for assessing histories of sexual arousal conditioning and derived stimulus associations. It is concluded that popular implicit tests are likely sensitive to conditioned and derived stimulus associations in the history of the test-taker rather than 'unconscious cognitions', per se

An externally loaded parametric oscillator

This paper is concerned with a novel problem in the field of parametric vibration whereby a single-degree-of-freedom oscillator is coupled to a power take-off mechanism so that the response of the oscillator in principal parametric resonance is directed towards doing work on an external body. The results show that it is possible for such an oscillator to transmit a certain amount of power from a vibrational source to a sink, in this case a weight which is lifted vertically. The existence of a steady state response of this nature shows that the imposition of an external load cannot be considered merely as a remote damping effect, and that oscillatory motion of the system can be maintained throughout provided the inherent damping within the system is minimized and that the necessary 2:1 relationship between the exciting frequency and the natural frequency of the oscillator is reasonably well maintained. Clearly, the external load also dictates the required threshold of excitation acceleration magnitude for the system to respond steadily. Considerable analytical, numerical, and experimental work has been carried out to substantiate the ideas proposed within the pape