Linking fine-scale behaviour to the hydraulic environment shows behavioural responses in riverine fish.

BACKGROUND: Fish migration has severely been impacted by dam construction. Through the disruption of fish migration routes, freshwater fish communities have seen an incredible decline. Fishways, which have been constructed to mitigate the problem, have been shown to underperform. This is in part due to fish navigation still being largely misunderstood. Recent developments in tracking technology and modelling make it possible today to track (aquatic) animals at very fine spatial (down to one meter) and temporal (down to every second) scales. Hidden Markov models are appropriate models to analyse behavioural states at these fine scales. In this study we link fine-scale tracking data of barbel (Barbus barbus) and grayling (Thymallus thymallus) to a fine-scale hydrodynamic model. With a HMM we analyse the fish's behavioural switches to understand their movement and navigation behaviour near a barrier and fishway outflow in the Iller river in Southern Germany. METHODS: Fish were tracked with acoustic telemetry as they approached a hydropower facility and were presented with a fishway. Tracking resulted in fish tracks with variable intervals between subsequent fish positions. This variability stems from both a variable interval between tag emissions and missing detections within a track. After track regularisation hidden Markov models were fitted using different parameters. The tested parameters are step length, straightness index calculated over a 3-min moving window, and straightness index calculated over a 10-min window. The best performing model (based on a selection by AIC) was then expanded by allowing flow velocity and spatial velocity gradient to affect the transition matrix between behavioural states. RESULTS: In this study it was found that using step length to identify behavioural states with hidden Markov models underperformed when compared to models constructed using straightness index. Of the two different straightness indices assessed, the index calculated over a 10-min moving window performed better. Linking behavioural states to the ecohydraulic environment showed an effect of the spatial velocity gradient on behavioural switches. On the contrary, flow velocity did not show an effect on the behavioural transition matrix. CONCLUSIONS: We found that behavioural switches were affected by the spatial velocity gradient caused by the attraction flow coming from the fishway. Insight into fish navigation and fish reactions to the ecohydraulic environment can aid in the construction of fishways and improve overall fishway efficiencies, thereby helping to mitigate the effects migration barriers have on the aquatic ecosystem.

Advocacy for use of the modified Iowa Level of Assistance Scale for clinical use in patients after hip replacement: an observational study.

OBJECTIVES: To test the internal consistency and item difficulty of the modified Iowa Level of Assistance Scale (mILAS). DESIGN: Retrospective observational study. SETTING: Two orthopaedic wards of two general hospitals. PARTICIPANTS: Following elective primary unilateral total hip replacement surgery, all participants performed mILAS activities that were scored daily to assess their recovery of activities during hospitalisation. MAIN OUTCOME MEASURES: The internal consistency and the level of assistance needed by the patient (item difficulty) of the mILAS were calculated using data from Deventer Hospital, Deventer, the Netherlands (n=255). A cross-validation was performed using data from Nij Smellinghe Hospital, Drachten, the Netherlands (n=224). RESULTS: The internal consistency of the mILAS was acceptable on all three postoperative days (α=0.84 to 0.97). Cronbach's α and Rasch analysis revealed a misfit of stair climbing with the other items of the mILAS. The item difficulty of the mILAS items changed over the first two postoperative days. During the first three postoperative days, the sit to supine transfer was generally the most difficult item to achieve, and the sit to stand transfer was the least difficult item to achieve as rated by physiotherapists. The cross-validation analysis revealed similar results. CONCLUSIONS: The mILAS is a clinically sound measurement tool to assess the ability of patients to perform five functional tasks safely during hospitalisation. Stair climbing appears to be the easiest item to complete, and the sit to supine transfer is generally the most difficult after surgery.

Pre-operative functional mobility as an independent determinant of inpatient functional recovery after total knee arthroplasty during three periods that coincided with changes in clinical pathways.

AIMS: To investigate whether pre-operative functional mobility is a determinant of delayed inpatient recovery of activities (IRoA) after total knee arthroplasty (TKA) in three periods that coincided with changes in the clinical pathway. PATIENTS AND METHODS: All patients (n = 682, 73% women, mean age 70 years, standard deviation 9) scheduled for TKA between 2009 and 2015 were pre-operatively screened for functional mobility by the Timed-up-and-Go test (TUG) and De Morton mobility index (DEMMI). The cut-off point for delayed IRoA was set on the day that 70% of the patients were recovered, according to the Modified Iowa Levels of Assistance Scale (mILAS) (a 5-item activity scale). In a multivariable logistic regression analysis, we added either the TUG or the DEMMI to a reference model including established determinants. RESULTS: Both the TUG (Odds Ratio (OR) 1.10 per second, 95% confidence intervals (CI) 1.06 to 1.15) and the DEMMI (OR 0.96 per point on the 100-point scale, 95% CI 0.95 to 0.98) were statistically significant determinants of delayed IRoA in a model that also included age, BMI, ASA score and ISAR score. These associations did not depend on the time period during which the TKA took place, as assessed by tests for interaction. CONCLUSION: Functional mobility, as assessed pre-operatively by the TUG and DEMMI, is an independent and stable determinant of delayed inpatient recovery of activities after TKA. Future research, focusing on improvement of pre-operative functional mobility through tailored physiotherapy intervention, should indicate whether such intervention enhances post-operative recovery among high-risk patients. Cite this article: Bone Joint J 2017;99-B:211-17.

What augmented physical activity and empowerment can bring to patients receiving total knee replacement: content, implementation, and comparative effectiveness of a new function-tailored care pathway in a routine care setting.

BACKGROUND: In the routine setting of the 20-bed orthopaedic ward of a regional hospital in Netherlands, we developed, implemented, and evaluated a new, function-tailored perioperative care pathway for patients receiving total knee replacement (TKR), aimed at faster functional recovery by reduction of inactivity and stimulation of self-efficacy of the patients. METHODS: To assess effectiveness, we compared, using prospectively collected data from medical files, patient groups before (n = 127) and after (n = 108) introduction of the new care pathway with respect to time to recovery of physical functioning during hospitalisation (five milestones), length of hospital stay (LoS), referrals to an inpatient rehabilitation facility, and readmissions. Multivariable regression was used to adjust results for differences between the two groups in preoperatively assessed risk factors for delayed recovery. RESULTS: Comparison of patient groups before (n = 127) and after (n = 108) introduction of the tailored care pathway showed that the tailored rehabilitation pathway decreased the time to recovery of physical functioning (from 4.5 to 4.1 days, P < 0.05), the mean LoS (from 5.2 days to 4.2 days, P < 0.01). CONCLUSION: We demonstrated that the introduction of a function-tailored care pathway shortens the hospital stay and accelerates the recovery of physical functioning.

What preoperative patient-related factors predict inpatient recovery of physical functioning and length of stay after total hip arthroplasty? A systematic review.

OBJECTIVE: To identify the preoperative patient-related characteristics predicting inpatient recovery of functioning and/or length of hospital stay after elective primary total hip arthroplasty. DESIGN: A search was conducted of the electronic databases MEDLINE, EMBASE and CINAHL from inception through April 2014. Observational studies were selected for systematic review if they identified clinically relevant preoperative prognostic factors and reported an association between inpatient recovery of physical functioning and/or length of hospital stay. Study participants were adults undergoing an elective primary total hip arthroplasty. RESULTS: Fourteen studies were included, a total of 199,410 individual total hip arthroplasty procedures. Two studies investigated inpatient recovery of physical functioning, no strong level of evidence was found for a relationship between functional recovery and any of the preoperative predictors. Twelve studies investigated the length of hospital stay and reported 19 preoperative prognostic factors. A strong level of evidence suggested that higher scores on the American Society of Anaesthesiologists assessment (OR 3.34 to 6.22, +0.20 days), increased number of comorbidities (RR of 1.10, +0.59 to 1.61 days), presence of heart disease, (RR of 1.59, +0.26 days), and presence of lung disease (RR of 1.30, +0.34 days) were associated with longer lengths of hospital stay following total hip arthroplasty. CONCLUSION: For the prediction of inpatient recovery of physical functioning no factors with a strong level of evidence were found. For length of stay there was a strong level of evidence for the American Society of Anaesthesiologists score, number of comorbidities, and presence of heart or lung disease.

The impact of waiting for total joint replacement on pain and functional status: a systematic review.

OBJECTIVE: To systematically describe changes in pain and functioning in patients with osteoarthritis (OA) awaiting total joint replacement (TJR), and to assess determinants of this change. METHODS: MEDLINE, EMBASE, CINAHL and Cochrane Database were searched through June 2008. The reference lists of eligible publications were reviewed. Studies that monitored pain and functioning in patients with hip or knee OA during the waiting list for TJR were analyzed. Data were collected with a pre-specified collection tool. Methodological quality was assessed and a best-evidence analysis was performed to summarize results. RESULTS: Fifteen studies, of which two were of high quality, were included and involved 788 hip and 858 knee patients (mean age 59-72 and main wait 42-399 days). There was strong evidence that pain (in hip and knee OA) and self-reported functioning (in hip OA) do not deteriorate during a <180 days wait. Conflicting evidence was established for the change on self-reported functioning in patients with knee OA waiting <180 days. Moreover, strong evidence was found for an association between the female gender and intensified pain. CONCLUSION: Patients with OA do not experience deterioration in pain or self-reported functional status whilst waiting <180 days for TJR. Changes over a longer waiting period are unclear. To strengthen and complement the present evidence, further high-quality studies are needed, in which preferably also performance-based measures are used.

Rapid, quantitative HPLC analysis ofAsclepias fruticosa L. andDanaus plexippus L. cardenolides.

The cardenolide extracts from latex and aerial parts ofAsclepias fruticosa and ofDanaus plexippus reared onA. fruticosa orA. curassavica were purified by adsorption chromatography on silica gel. HPLC analysis on a C18 reverse-phase column with an acetonitrile-water gradient as mobile phase, separated 28 compounds with a UV spectrum typical forcardenolides. Afroside and gomphoside (major components), as well as calotropagenin, calotoxin, calotropin, calactin, uscharidin, uscharin, and voruscharin, occurred as single peaks in the profiles of latex and aerial plant parts ofA. fruticosa. Calactin and calotropin were the major cardenolides inDanaus plexippus reared onA. fruticosa orA. curassavica. Quantitative data obtained with digitoxin as internal standard showed that 1.3-1.5% of the leaf cardenolides were sequestered byDanaus plexippus in which levels of 70-80µg cardenolide per butterfly were measured. The calotropin from the leaves was almost completely sequestered, and 10-13% of the calactin was stored by the butterfly, assuming that no conversion occurred in larval tissues.