The relative abundance, movement, and growth of rainbow trout (Salmo gairdneri) and brown trout (Salmo trutta) in the Rangitikei River, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science with Honours in Zoology at Massey University

The null hypothesis tested was that rainbow and brown trout populations do not move between naturally defined sections of the Rangitikei River. It was found to be true for adult brown trout but false for rainbow trout. Recaptures of tagged brown trout demonstrated that the majority of these fish living in the mid-reaches do not make seasonal movements between river sections. Brown trout dwelling in the lower reaches were smaller than mid-reach brown trout. This difference, and the lack of tag returns indicating movement between the two sections, supports the hypothesis. Recaptures of tagged rainbow trout demonstrated that the majority of these fish migrating from the mid-reaches in autumn and winter travel to the headwaters where they remain the following summer. Those rainbow trout which were recaptured in the headwaters after moving from the mid-reaches tended to migrate earlier in the winter than those captured, then later recaptured, in the mid-reaches. Similarities in the size of rainbow trout spawning migrants captured in the lower reaches and the mid-reaches suggested that both groups spent at least their second and third years in the same area of the river, but low numbers of tag returns meant that no firm conclusions regarding rainbow trout movement between the mid and lower reaches could be made. Limited data concerning movement during the summer period suggested that some rainbow and brown trout move within sections but evidence of individuals remaining in one place for extended periods was found also. Reported behaviour of both species of trout in response to seasonal physiological changes and agonistic pressure, allied with stream bed morphology probably accounted for the observed distribution of young of the year, year one, year two and adult trout in the river. Upstream migrating adults, of both species counted at two traps, were found to respond to fluctuations in water flow and were probably affected by moon phase so that migratory activity was saltatory. Rainbow trout tended to migrate earlier in the winter than brown trout. The movement of female brown trout followed the male brown trout migration but similar differences were not observed in the rainbow trout migrants

Day case angioplasty in a secondary care setting – initial experience

Background: Peripheral artery disease presents an increasing healthcare burden worldwide. Day-case angioplasty in a secondary care setting can be a safe and effective means of meeting the growing demand for lower limb revascularisation. We evaluated the safety and efficacy of a day-case-based angioplasty service in a UK district general hospital. Patients and methods: Consecutive patients undergoing endovascular revascularisation between August 2018–February 2020 were analysed retrospectively. All patients were discussed at a multi-disciplinary (diabetic foot) team meeting following a day case algorithm. Patient and procedural characteristics, technical success, peri-procedural complications, and 30-day outcome of day-case angioplasties were compared with those requiring overnight stay or were hospitalized. Results: Fifty-seven percent of 138 patients were diabetic, mean age 75 ± 12 years, 95% had critical limb ischaemia (Fontaine III 12%, IV 83%), and baseline ankle brachial pressure index [ABPI] 0.40 ± 0.30. Sixty-three patients (45%) were treated as planned day cases, 21 (15%) required overnight admission for social indications. Fifteen (11%) were planned admissions with the need for sequential debridement procedures, and 39 (28%) were already hospitalised at the time of referral to the vascular service. The overall technical success was 92% and not successful procedures mainly occurred in patients > 80 years. The ABPI increased at the initial follow-up to 0.84 ± 0.18. Fifty-three percent required treatment of > 1 level, 80% included recanalisations of chronic total occlusions, and average total lesion length was 133 ± 90 mm. Closure devices were employed in all cases. There were no major peri-procedural complications. A single minor access-site related bleeding episode (0.8%) occurred, requiring 24 h observation in hospital. While significantly more wounds had closed in out-patients, the mortality, major amputation and target lesion revascularization did not differ between groups. Conclusions: Safe and effective day-case-based angioplasty can be provided in a secondary care setting for patients with critical limb ischaemia needing complex multi-level procedures

Ankle Doppler for Cuffless Ankle Brachial Index Estimation and Peripheral Artery Disease Diagnosis Independent of Diabetes

Ankle brachial pressure index (ABPI) is the first-line test to diagnose peripheral artery disease (PAD). Its adoption in clinical practice is poor and its validity, particularly in diabetes, is limited. We hypothesised that ABPI can be accurately and precisely estimated based on cuffless Doppler waveforms. Retrospective analysis of standard ABPI and handheld Doppler waveform characteristics (n = 200). Prospective analysis of angle-corrected Doppler acceleration index (AccI, n = 148) and standard ABPI with testing of performance to diagnose PAD as assessed with imaging reference standards in consecutive patients. The highest AccI from handheld Doppler at ankle arteries was significantly logarithmically associated with the highest standard ABPI (E[y] = 0.32 ln [1.71 ∗ x + 1], p R2 = 0.68, n = 100 limbs). Estimated ABPI (eABPI) based on AccI closely resembled ABPI (r = 0.81, p n = 100 limbs). AccI from angle-corrected Doppler in patients without overt media sclerosis (ABPI ≤ 1.1) improved ABPI prediction (E[y] = 0.297 ∗ ln[0.039 ∗ x + 1], R2 = 0.92, p = 0.006, average deviation 0.00 ± 0.08, n = 100). In a population (n = 148 limbs) including diabetes (56%), chronic limb-threatening ischaemia (51%) and media sclerosis (32%), receiver operating characteristics analysis of (angle-corrected) eABPI performed significantly better than standard ABPI to diagnose PAD defined by ultrasound (ROC AUC = 0.99 ± 0.01, p p p = 0.608). ABPI can be estimated based on ankle Doppler AccI without compression, and eABPI performs better than standard ABPI to diagnose PAD independent of diabetes. eABPI has the potential to be included as a standard component of lower extremity ultrasound