Acoustic deterrents influence foraging activity, flight and echolocation behaviour of free-flying bats.

Acoustic deterrents have shown potential as a viable mitigation measure to reduce human impacts on bats; however, the mechanisms underpinning acoustic deterrence of bats have yet to be explored. Bats avoid ambient ultrasound in their environment and alter their echolocation calls in response to masking noise. Using stereo thermal videogrammetry and acoustic methods, we tested predictions that: (i) bats would avoid acoustic deterrents and forage and social call less in a 'treated airspace'; (ii) deterrents would cause bats to fly with more direct flight paths akin to commuting behaviour and in line with a reduction in foraging activity, resulting in increased flight speed and decreased flight tortuosity; and (iii) bats would alter their echolocation call structure in response to the masking deterrent sound. As predicted, overall bat activity was reduced by 30% and we recorded a significant reduction in counts of Pipistrellus pygmaeus (27%), Myotis spp. (probably M. daubentonii) (26%), and Nyctalus spp. and Eptesicus spp. (68%) passes. Pipistrellus pygmaeus feeding buzzes were also reduced by the deterrent in relation to general activity (by 38%); however, social calls were not (only 23% reduction). Bats also increased their flight speed and reduced the tortuosity of their flight paths, and P. pygmaeus reduced echolocation call bandwidth and start frequency of calls in response to deterrent playback, probably owing to the masking effect of the sound. Deterrence could therefore be used to remove bats from areas where they forage, for example wind turbines and roads, where they may be under threat from direct mortality.

Comparing acoustic and radar deterrence methods as mitigation measures to reduce human-bat impacts and conservation conflicts.

Where humans and wildlife co-exist, mitigation is often needed to alleviate potential conflicts and impacts. Deterrence methods can be used to reduce impacts of human structures or activities on wildlife, or to resolve conservation conflicts in areas where animals may be regarded as a nuisance or pose a health hazard. Here we test two methods (acoustic and radar) that have shown potential for deterring bats away from areas where they forage and/or roost. Using both infrared video and acoustic methods for counting bat passes, we show that ultrasonic speakers were effective as bat deterrents at foraging sites, but radar was not. Ultrasonic deterrents decreased overall bat activity (filmed on infrared cameras) by ~80% when deployed alone and in combination with radar. However, radar alone had no effect on bat activity when video or acoustic data were analysed using generalised linear mixed effect models. Feeding buzzes of all species were reduced by 79% and 69% in the ultrasound only treatment when compared to the control and radar treatments, but only the ultrasound treatment was significant in post-hoc tests. Species responded differently to the ultrasound treatments and we recorded a deterrent effect on both Pipistrellus pipistrellus (~40-80% reduction in activity) and P. pygmaeus (~30-60% reduction), but not on Myotis species. However, only the ultrasound and radar treatment was significant (when compared to control and radar) in post-hoc tests for P. pipistrellus. Deterrent treatment was marginally non-significant for P. pygmaeus, but the ultrasound only treatment was significant when compared to radar in post-hoc tests. We therefore suggest that acoustic, but not radar methods are explored further as deterrents for bats. The use of acoustic deterrence should always be assessed on a case-by-case basis, with a focus on bat conservation.

The learning curve of electronic prescribing.

INTRODUCTION: Medication errors are a potentially avoidable source of harm to patients. The authors' hospital has introduced electronic prescribing in an attempt to reduce these errors. A prospective quality improvement project was performed to assess both the impact of this change on prescribing errors and to see if there was a learning curve associated with prescribers using the new system. METHODS: A simple prescribing task was created in which study participants were asked to prescribe a set list of medications for a fictional patient. The participants were timed first using paper drug cards, and then using the prescribing function on iSOFT's iClinical Manager. The prescriptions were also assessed for legibility and errors. This was done within 1 week of the participants starting in the department, and then 2 and 4 months later. A total of 25 junior doctors completed the task. No participant had prior experience of electronic prescribing in a clinical setting. RESULTS: During week one, the task took a longer average time to complete using electronic prescribing compared to paper (323 seconds vs 290 seconds, P<0.01). After 2 months the mean time to complete the task was shorter with electronic prescribing compared to paper (261 seconds vs 306 seconds, P<0.01). There was therefore a significant mean reduction in the time taken to complete the task using electronic prescribing of 62 seconds (P=0.01). There were fewer illegible entries or drug errors using electronic prescribing compared to paper prescribing (2.7% vs 5.3%, P=0.68). CONCLUSIONS: Electronic prescribing appears to reduce prescribing errors. However, there is a learning curve for new doctors using electronic prescribing. Training and support is vital during this period in order to reduce prescribing errors.

Nonlinear elastic wave tomography for the imaging of corrosion damage.

This paper presents a nonlinear elastic wave tomography method, based on ultrasonic guided waves, for the image of nonlinear signatures in the dynamic response of a damaged isotropic structure. The proposed technique relies on a combination of high order statistics and a radial basis function approach. The bicoherence of ultrasonic waveforms originated by a harmonic excitation was used to characterise the second order nonlinear signature contained in the measured signals due to the presence of surface corrosion. Then, a radial basis function interpolation was employed to achieve an effective visualisation of the damage over the panel using only a limited number of receiver sensors. The robustness of the proposed nonlinear imaging method was experimentally demonstrated on a damaged 2024 aluminium panel, and the nonlinear source location was detected with a high level of accuracy, even with few receiving elements. Compared to five standard ultrasonic imaging methods, this nonlinear tomography technique does not require any baseline with the undamaged structure for the evaluation of the corrosion damage, nor a priori knowledge of the mechanical properties of the specimen.

Thrombosis of the external jugular vein: a rare complication of a proximal humerus fracture treated with collar and cuff immobilisation.

We report the case of an 87-year-old woman who developed a thrombosis of her external jugular vein after sustaining a proximal humerus fracture managed nonoperatively with a collar and cuff. At review in fracture clinic she was found to have an enlarged external jugular vein which was subsequently found to be thrombosed. Her collar and cuff had been applied very tightly and it was felt by the ENT team to be the cause of the thrombosis of her external jugular vein. She was fully anticoagulated with warfarin after subsequently developing a deep vein thrombosis in the subclavian and axillary veins. She made a full recovery following anticoagulation. In this case, we review the potential causes of this rare and underdiagnosed condition, as well as the usual investigations and treatments. We also review the common complications of this fracture and the alternative treatment options available.

Is ultrasound diagnosis reliable in acute extensor tendon injuries of the knee?

Ruptures of the patellar and quadriceps tendon are rare injuries requiring immediate repair to re-establish knee extensor continuity and allow early motion. Ultrasound is extensively used as a diagnostic tool before surgery on acute traumatic tears of the patellar tendon and quadriceps tendons. The aim of our study was to evaluate the role of sonography in diagnosing quadriceps and patellar tendon rupture and in differentiating partial from complete tears. We conducted a retrospective review of 51 consecutive patients who had a surgical intervention for suspected acute quadriceps and patellar tendon rupture over a 5-year period. Intra-operative findings were compared with pre-operative clinical examination. Radiographs, ultrasound and MRI reports were reviewed. On clinical examination, 22 patients had a suspected patellar tendon rupture and 29 patients had a suspected quadriceps tendon rupture. Diagnosis was confirmed by clinical examination and plain radiographs alone in 13 patients, with additional ultrasound performed in 24 patients and MRI scan performed in 14 patients. There were 8 false positives out of 24 [33.3%] in the ultrasound proven group and 1 false positive out of 13 [7.69%] in the clinical examination and radiographs only group. MRI was 100% accurate. We conclude that ultrasonography is not a reliable method in establishing the diagnosis of acute injuries to the extensor mechanism of the knee, particularly the quadriceps tendon ruptures in the obese and the very muscular patients. If there is clinical ambiguity, MRI scan is a better investigation tool before undertaking surgical treatment.

Reducing metal debris generation during total knee arthroplasty.

Blade design can have a large effect on the surgical wear debris produced during TKA, and has quantified the weight of debris lost from the blades and cutting blocks. In the effort to address this metal debris generation, an oscillating-tip blade such as the Precision blade can significantly reduce the amount of debris produced.