When hawks attack: animal-borne video studies of goshawk pursuit and prey-evasion strategies.

Video filmed by a camera mounted on the head of a Northern Goshawk (Accipiter gentilis) was used to study how the raptor used visual guidance to pursue prey and land on perches. A combination of novel image analysis methods and numerical simulations of mathematical pursuit models was used to determine the goshawk's pursuit strategy. The goshawk flew to intercept targets by fixing the prey at a constant visual angle, using classical pursuit for stationary prey, lures or perches, and usually using constant absolute target direction (CATD) for moving prey. Visual fixation was better maintained along the horizontal than vertical direction. In some cases, we observed oscillations in the visual fix on the prey, suggesting that the goshawk used finite-feedback steering. Video filmed from the ground gave similar results. In most cases, it showed goshawks intercepting prey using a trajectory consistent with CATD, then turning rapidly to attack by classical pursuit; in a few cases, it showed them using curving non-CATD trajectories. Analysis of the prey's evasive tactics indicated that only sharp sideways turns caused the goshawk to lose visual fixation on the prey, supporting a sensory basis for the surprising frequency and effectiveness of this tactic found by previous studies. The dynamics of the prey's looming image also suggested that the goshawk used a tau-based interception strategy. We interpret these results in the context of a concise review of pursuit-evasion in biology, and conjecture that some prey deimatic 'startle' displays may exploit tau-based interception.

A Systematic Review of Derived Relational Responding Beyond Coordination in Individuals with Autism and Intellectual and Developmental Disabilities.

As interest in derived relational responding has increased, so have the number of investigations evaluating interventions to promote the emergence of derived responding for individuals with autism, as well as other intellectual and developmental disabilities. However, much of the literature has focused on the relation of sameness, and less is known about interventions to facilitate derived responding in other relations. Systematic searches identified 38 studies contained in 30 articles that met inclusion criteria. These studies were analyzed according to their participants, assessment methods, experimental design, content taught, setting, teaching procedures, derived responses, outcomes, and reliability measures. The quality of the studies was measured using the Single Case Analysis and Research Framework (SCARF). The results of the current review indicate that many learners with autism spectrum disorder and other intellectual and developmental disabilities demonstrate derived relational responding beyond the relation of coordination across varied instructional content and teaching methodologies, but the quality and rigor of the published literature requires the results be interpreted with caution, leading to recommendations for future research.

Service evaluation of an intravenous sedation service within a hospital paediatric dentistry unit: ten-year results.

Background An intravenous sedation (IVS) service was established in 2008 for young people aged 12 years or over, within the paediatric dentistry department at the Eastman Dental Hospital in London. The aim of this study was to carry out a service evaluation and assess the case mix and success rate of this service over the last ten years.Materials and methods A retrospective service evaluation was carried out, including all patients attending the IVS clinic between April 2009 and March 2019.Results A total of 457 patients attended over 525 appointments. The mean age was 14. The success rate was over 98%. The average dose of midazolam was 4 mg and dosage ranged from 1.5-10 mg.Conclusion This IVS service has been established successfully and offers patients an alternative to general anaesthetic. This consequently reduced the general anaesthetic waiting list by 10%.

Oral manifestations of vitamin D deficiency in children.

Vitamin D is key to the musculoskeletal system. Its deficiency can arise from lack of exposure to sunlight and through dietary insufficiency. This can have an impact upon the oral health of an individual, including resulting in chronological hypoplasia enamel defects. Enamel hypoplasia is a quantitative defect in the enamel, presenting as pits, grooves, missing enamel or smaller teeth. The management of these defects can present a challenge to the dentist. This paper outlines the oral manifestations of vitamin D deficiency in the permanent dentition and the treatment modalities used in their management.

The availability and characteristics of patient-focused YouTube videos related to oral hygiene instruction.

Introduction YouTube is a popular social media platform that is being increasingly used for the distribution of healthcare-related information. To date, there appear to be no published studies assessing the quality of oral hygiene instruction provided by YouTube videos.Objective To assess the availability, quality and accuracy of patient-focused YouTube videos aiming to provide oral hygiene instruction.Method YouTube videos meeting the inclusion criteria were evaluated for quality and information accuracy using an eight-item, evidence-based checklist relating to important aspects in the prevention of caries and periodontal disease.Results Fifty-two relevant videos were included; 20 videos (38.5%) were produced by lay people (social media influencers and bloggers) who had no professional qualifications. None of the included videos contained accurate information relating to all eight items of the evidence-based checklist. Seven videos contained none of the information from the checklist. Numerous videos contained health advice which was not scientifically sound.Conclusion The results of this study highlight that currently available YouTube videos may not contain evidence-based information relating to oral hygiene instruction. There are also concerns regarding the lack of regulation and quality assurance processes in the development of healthcare-related YouTube videos. Currently, clinicians should be cautious when advising patients to utilise YouTube as a source of information regarding oral health.

A radiographic study of estimating age by deciduous mandibular canine and molar root resorption.

BACKGROUND AND AIM: Root resorption of deciduous teeth is an important aspect of dental development; however, the accuracy of using root resorption as a method of estimating age has not been reported. The aim of this study was to assess the accuracy of estimating age from fractions of resorbed root in mandibular deciduous canines and molars, using published reference data. METHODS: The sample was 940 dental panoramic radiographs of dental patients aged 3-16. Deciduous mandibular canine and molar roots were staged into levels of resorption (one quarter, one half and three quarters). Reliability of root fractions was assessed using 193 duplicate readings and calculated using Kappa. Age was estimated using Moorrees et al. (1963), Fanning (1961), and O'Meara and Knott (1967), and the difference between dental and chronological ages tested using t-test. Accuracy was defined as a difference not significant to zero (P<0.05). RESULTS: Results show that assessment of levels of root resorption was excellent (Kappa 0.88-0.94). Some root fractions of molars estimated age accurately; however, the standard deviation was more than 2 years. The average difference between dental and chronological ages ranged from 0.12 to -2.04 years with standard deviation values up to 2 years and the most accurate method was O'Meara and Knott (1967). CONCLUSION: Fractions of deciduous root resorption can help to predict age.

Purification of monoclonal antibody against Ebola GP1 protein expressed in Nicotiana benthamiana.

Monoclonal antibodies (mAbs) are one of the fastest growing drug molecules targeting the treatment of diseases ranging from arthritis, immune disorders, and infectious diseases to cancer. Due to its unique application principle, antibodies are commonly produced in large quantities. Plants, such as Nicotiana benthamiana, offer a unique production platform for bio-therapeutics due to their ability to produce large amounts of biomolecules in a relatively quick manner. However, purification of a target protein from plant is an arduous task due to the presence of toxic compounds in ground plant tissue and the large quantities of plant tissues to be processed. Here, a process was developed prior to the chromatographic purification of a mAb against Ebola GP1 protein expressed in N. benthamiana. The process includes a diafiltration step and a charged polyelectrolyte precipitation. The diafiltration step significantly improved the precipitation efficiency, reducing the usage of polyelectrolyte by more than 2000 fold while improving the native plant protein removed from 60% to 80%. The mAb can then be purified to near homogeneity judging from SDS-PAGE by either Protein A affinity chromatography or a tandem of hydrophobic interaction chromatography and a hydrophobic charge induction chromatography. The purified mAbs were shown to retain their binding specificity to irradiated Ebola virus.

Development and scale-up of a commercial fed batch refolding process for an anti-CD22 two chain immunotoxin.

We describe the development and scale-up of a novel two chain immunotoxin refolding process. This work provides a case study comparing a clinical manufacturing process and the commercial process developed to replace it. While the clinical process produced high quality material, it suffered from low yield and high yield variability. A systematic approach to process development and understanding led to a number of improvements that were implemented in the commercial process. These include a shorter inclusion body recovery process, limiting the formation of an undesired deamidated species and the implementation of fed batch dilution refolding for increased refold titers. The use of a combination of urea, arginine and DTT for capture column cleaning restored the binding capacity of the capture step column and resulted in consistent capture step yields compared to the clinical process. Scalability is shown with data from 250 L and 950 L scale refolding processes. Compared to the clinical process it replaces, the commercial process demonstrated a greater than fivefold improvement in volumetric productivity at the 950 L refolding scale.