Coursing hyenas and stalking lions: The potential for inter- and intraspecific interactions.

Resource partitioning promotes coexistence among guild members, and carnivores reduce interference competition through behavioral mechanisms that promote spatio-temporal separation. We analyzed sympatric lion and spotted hyena movements and activity patterns to ascertain the mechanisms facilitating their coexistence within semi-arid and wetland ecosystems. We identified recurrent high-use (revisitation) and extended stay (duration) areas within home ranges, as well as correlated movement-derived measures of inter- and intraspecific interactions with environmental variables. Spatial overlaps among lions and hyenas expanded during the wet season, and occurred at edges of home ranges, around water-points, along pathways between patches of high-use areas. Lions shared more of their home ranges with spotted hyenas in arid ecosystems, but shared more of their ranges with conspecifics in mesic environments. Despite shared space use, we found evidence for subtle temporal differences in the nocturnal movement and activity patterns between the two predators, suggesting a fine localized-scale avoidance strategy. Revisitation frequency and duration within home ranges were influenced by interspecific interactions, after land cover categories and diel cycles. Intraspecific interactions were also important for lions and, important for hyenas were moon illumination and ungulates attracted to former anthrax carcass sites in Etosha, with distance to water in Chobe/Linyanti. Recursion and duration according to locales of competitor probabilities were similar among female lions and both sexes of hyenas, but different for male lions. Our results suggest that lions and spotted hyenas mediate the potential for interference competition through subtle differences in temporal activity, fine-scale habitat use differentiation, and localized reactive-avoidance behaviors. These findings enhance our understanding of the potential effects of interspecific interactions among large carnivore space-use patterns within an apex predator system and show adaptability across heterogeneous and homogeneous environments. Future conservation plans should emphasize the importance of inter- and intraspecific competition within large carnivore communities, particularly moderating such effects within increasingly fragmented landscapes.

Intraoperative Needle Tip Tracking with an Integrated Fibre-Optic Ultrasound Sensor.

Ultrasound is an essential tool for guidance of many minimally-invasive surgical and interventional procedures, where accurate placement of the interventional device is critical to avoid adverse events. Needle insertion procedures for anaesthesia, fetal medicine and tumour biopsy are commonly ultrasound-guided, and misplacement of the needle may lead to complications such as nerve damage, organ injury or pregnancy loss. Clear visibility of the needle tip is therefore critical, but visibility is often precluded by tissue heterogeneities or specular reflections from the needle shaft. This paper presents the in vitro and ex vivo accuracy of a new, real-time, ultrasound needle tip tracking system for guidance of fetal interventions. A fibre-optic, Fabry-Pérot interferometer hydrophone is integrated into an intraoperative needle and used to localise the needle tip within a handheld ultrasound field. While previous, related work has been based on research ultrasound systems with bespoke transmission sequences, the new system-developed under the ISO 13485 Medical Devices quality standard-operates as an adjunct to a commercial ultrasound imaging system and therefore provides the image quality expected in the clinic, superimposing a cross-hair onto the ultrasound image at the needle tip position. Tracking accuracy was determined by translating the needle tip to 356 known positions in the ultrasound field of view in a tank of water, and by comparison to manual labelling of the the position of the needle in B-mode US images during an insertion into an ex vivo phantom. In water, the mean distance between tracked and true positions was 0.7 ± 0.4 mm with a mean repeatability of 0.3 ± 0.2 mm. In the tissue phantom, the mean distance between tracked and labelled positions was 1.1 ± 0.7 mm. Tracking performance was found to be independent of needle angle. The study demonstrates the performance and clinical compatibility of ultrasound needle tracking, an essential step towards a first-in-human study.

Erratum: Extrapyramidal side effects in first-episode schizophrenia treated with flupenthixol decanoate.

[This corrects the article DOI: 10.4102/sajpsychiatry.v27i0.1568.].

Extrapyramidal side effects in first-episode schizophrenia treated with flupenthixol decanoate.

BACKGROUND: Concern for the development of extrapyramidal side effects (EPSEs) represents a barrier to the routine use of long-acting injectable (LAI) antipsychotic medication in patients with first-episode schizophrenia (FES). Flupenthixol decanoate is a first-generation antipsychotic, which is readily available in the public healthcare system in South Africa. AIM: The aim of this study was to describe the nature, occurrence and severity of EPSEs and their impact on patients with FES over 12 months of treatment with flupenthixol decanoate (fluanxol depot). SETTING: The study was based in Cape Town, South Africa, and patients with FES were recruited from inpatient services at Stikland and Tygerberg Hospitals and surrounding psychiatric clinics. This was a sub-study of a larger study, which examined several outcomes in patients with FES treated with the lowest effective dose of flupenthixol decanoate. METHODS: The Extrapyramidal Symptom Rating Scale (ESRS) was used to assess both subjective experience and objective measures of EPSEs in a cohort of patients with FES (N = 130). The relationship between demographic and clinical risk factors for individual subsets of EPSEs was also determined. RESULTS: In the context of an overall good 12-month tolerability, EPSEs peaked at month 3. Patients with akathisia were more likely to have greater symptoms of depression, and Parkinsonism was predicted by higher Positive and Negative Syndrome Scale scores (independent of medication dosage). Black and white patients showed higher total ESRS and higher subjective ESRS scores, compared with patients of mixed ancestry, and white patients scored higher on Parkinsonism ratings. CONCLUSION: Flupenthixol decanoate is well tolerated in patients with FES. Certain clinical features of schizophrenia may be related to EPSEs. Ethnicity is a socio-cultural construct, and hence the differential risk of EPSEs should be interpreted according to ethnicity. Variations in the environment, diet, substance use and genetics may all affect the pharmacokinetics and pharmacodynamics of psychotropic drugs and warrant further investigation.

The effectiveness of Schroth exercises in adolescents with idiopathic scoliosis: A systematic review and meta-analysis.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is one of the most common structural spinal deformities in adolescents, becoming apparent around the time of puberty. Schroth scoliosis-specific exercises have demonstrated promising results in reducing the progression of AIS. OBJECTIVES: The aim of this study was to identify, critically appraise and establish the best available evidence for the effectiveness of Schroth exercises in comparison to non-surgical management to reduce the progression of AIS. METHODOLOGY: Seven databases were searched in April 2018. Main key search terms included AIS, Schroth exercises, physiotherapy, exercise, electrical stimulation, yoga, Pilates, tai chi and bracing. The quality of the trials was critically appraised according to the PEDro scale. Revman© Review Manager Software was used to pool the quality of life (QOL) results. RESULTS: Four randomised control trials with an average PEDro score of 6.75/10 were included in this study. Results indicated that Schroth exercises had a significant effect in decreasing the Cobb angle (p < 0.05) in comparison to non-surgical management. The pooled effect on QOL showed a significant result in favour of Schroth exercises at 12 weeks (p < 0.002) and at 24 weeks (p < 0.0004). CONCLUSION: Level II evidence suggests that Schroth exercises have a significant effect on reducing the Cobb angle and improving QOL in adolescents with idiopathic scoliosis. CLINICAL IMPLICATIONS: This review's findings should be considered with caution for physiotherapy practice because of the limited number of identified articles and their methodologic limitations. Based on the current available and limited evidence, clinicians could combine supervised Schroth exercises with conventional physiotherapy care (observation, exercise, bracing and manual therapy) when treating adolescents with idiopathic scoliosis.

Prevalence, causes and socio-economic determinants of vision loss in Cape Town, South Africa.

PURPOSE: To estimate the prevalence and causes of blindness and visual impairment in Cape Town, South Africa and to explore socio-economic and demographic predictors of vision loss in this setting. METHODS: A cross sectional population-based survey was conducted in Cape Town. Eighty-two clusters were selected using probability proportionate to size sampling. Within each cluster 35 or 40 people aged 50 years and above were selected using compact segment sampling. Visual acuity of participants was assessed and eyes with a visual acuity less than 6/18 were examined by an ophthalmologist to determine the cause of vision loss. Demographic data (age, gender and education) were collected and a socio-economic status (SES) index was created using principal components analysis. RESULTS: Out of 3100 eligible people, 2750 (89%) were examined. The sample prevalence of bilateral blindness (presenting visual acuity <3/60) was 1.4% (95% CI 0.9-1.8). Posterior segment diseases accounted for 65% of blindness and cataract was responsible for 27%. The prevalence of vision loss was highest among people over 80 years (odds ratio (OR) 6.9 95% CI 4.6-10.6), those in the poorest SES group (OR 3.9 95% CI 2.2-6.7) and people with no formal education (OR 5.4 95% CI 1.7-16.6). Cataract surgical coverage was 68% in the poorest SES tertile (68%) compared to 93% in the medium and 100% in the highest tertile. CONCLUSIONS: The prevalence of blindness among people ≥50 years in Cape Town was lower than expected and the contribution of posterior segment diseases higher than previously reported in South Africa and Sub Saharan Africa. There were clear socio-economic disparities in prevalence of vision loss and cataract surgical coverage in this setting which need to be addressed in blindness prevention programs.