Looking for Synergies in Healthy Upper Limb Motion: A Focus on the Wrist.

Recent studies on human upper limb motion highlighted the benefit of dimensionality reduction techniques to extrapolate informative joint patterns. These techniques can simplify the description of upper limb kinematics in physiological conditions, serving as a baseline for the objective assessment of movement alterations, or to be implemented in a robotic joint. However, the successful description of kinematic data requires a proper alignment of the acquisitions to correctly estimate kinematic patterns and their motion variability. Here, we propose a structured methodology to process and analyze upper limb kinematic data, considering time warping and task segmentation to register task execution on a common normalized completion time axis. Functional principal component analysis (fPCA) was used to extract patterns of motion of the wrist joint from the data collected by healthy participants performing activities of daily living. Our results suggest that wrist trajectories can be described as a linear combination of few functional principal components (fPCs). In fact, three fPCs explained more than 85% of the variance of any task. Wrist trajectories in the reaching phase of movement were highly correlated among participants and significantly more than trajectories in the manipulation phase ( [Formula: see text]). These findings may be useful in simplifying the control and design of robotic wrists, and could aid the development of therapies for the early detection of pathological conditions.

The myokinetic stimulation interface: activation of proprioceptive neural responses with remotely actuated magnets implanted in rodent forelimb muscle.

Objective. Proprioception is the sense of one's position, orientation, and movement in space, and it is of fundamental importance for motor control. When proprioception is impaired or absent, motor execution becomes error-prone, leading to poorly coordinated movements. The kinaesthetic illusion, which creates perceptions of limb movement in humans through non-invasively applying vibrations to muscles or tendons, provides an avenue for studying and restoring the sense of joint movement (kinaesthesia). This technique, however, leaves ambiguity between proprioceptive percepts that arise from muscles versus those that arise from skin receptors. Here we propose the concept of a stimulation system to activate kinaesthesia through the untethered application of localized vibration through implanted magnets.Approach. In this proof-of-concept study, we use two simplified one-DoF systems to show the feasibility of eliciting muscle-sensory responses in an animal model across multiple frequencies, including those that activate the kinaesthetic illusion (70-115 Hz). Furthermore, we generalized the concept by developing a five-DoF prototype system capable of generating directional, frequency-selective vibrations with desired displacement profiles.Main results. In-vivotests with the one-DoF systems demonstrated the feasibility to elicit muscle sensory neural responses in the median nerve of an animal model. Instead,in-vitrotests with the five-DoF prototype demonstrated high accuracy in producing directional and frequency selective vibrations along different magnet axes.Significance. These results provide evidence for a new technique that interacts with the native neuro-muscular anatomy to study proprioception and eventually pave the way towards the development of advanced limb prostheses or assistive devices for the sensory impaired.

First Report on the Use of Larvae of Cochliomyia macellaria (Diptera: Calliphoridae) for Wound Treatment in Veterinary Practice.

Factors contributing to the delay or prevention of the natural wound healing process include infection and ineffective conventional treatment. Alternative therapies, such as the maggot debridement therapy (MDT), may be helpful for successful treatment in these cases. Aiming to disseminate information about the possibility of using other species of flies for wound treatment, besides the best known Lucilia sericata Meigen, 1826 (Diptera, Calliphoridae), we report here a successful MDT case with the application of Cochliomyia macellaria (Fabricius, 1775) larvae to treat an infected wound with extensive area of necrotic tissue in a dog. Five sterile larvae were applied to each square-cm of lesion and kept on the animal for only 48 h. The healing was successful, from both qualitative and quantitative points of view. The ratio of wound healing (RWH) reached almost 50% on the 5th day and 100% on the 14th day after MDT. Although the overall animal prognosis had been unfavorable, mainly due to the sepsis, the patient began to recover and had improved clinical condition from the fifth day after MDT. This study shows the importance and effectiveness of MDT in promoting faster and more complete healing of a complex wound.

First Record of Larval Secretions of Cochliomyia macellaria (Fabricius, 1775) (Diptera: Calliphoridae) Inhibiting the Growth of Staphylococcus aureus and Pseudomonas aeruginosa.

Maggot debridement therapy (MDT) consists on the intentional and controlled application of sterilized larvae of the order Diptera on necrotic skin lesions with the purpose of cleaning necrotic tissue and removing pathogenic bacteria. During MDT, a marked antimicrobial activity has been reported in literature specially associated with antibacterial substances from Lucilia sericata (Meigen); however, regarding Cochliomyia macellaria (Fabricius), little is known. This study aimed to evaluate in vitro inhibition of bacterial growth of Pseudomonas aeruginosa and Staphylococcus aureus in contact with excretions and secretions (ES) from C. macellaria larvae. Larval ES were extracted in sterile distilled water and divided in three groups: ES, containing 400 µL of autoclaved ES; ES+BAC, containing 400 µL of autoclaved ES+0.5-µL bacterial inoculum; and CONT-BAC, containing 400 µL of sterile distilled water +0.5 µL of bacterial inoculum. Aliquots of each experimental group were plated by spreading onto Petri dishes. Seedings were made at 0, 1, 2, 4, and 12 h after the extraction of ES. In ES+BAC groups, inhibition of S. aureus was verified between times 1 and 2 h and P. aeruginosa was inhibited between 0 and 4 h. There was no growth observed in any ES group. In the CONT-BAC groups, the number of colonies from time 4 h became countless for S. aureus and decreased for P. aeruginosa. As reported in the literature, we note here that ES have excellent bactericidal activity for both gram-positive and gram-negative bacteria, and this study shows for the first time the action of the bactericidal activity of exosecretions of C. macellaria against S. aureus and P. aeruginosa.