Preliminary Evaluation of a System with On-Body and Aerial Sensors for Monitoring Working Dogs.

This paper presents a system for behavioral, environmental, and physiological monitoring of working dogs using on-body and aerial sensors. The proof of concept study presented here includes two trained dogs performing nine scent detection tasks in an uncontrolled environment encompassing approximately two acres. The dogs were outfitted with a custom designed wearable harness to monitor their heart rate, activity levels and skin temperature. We utilized a commercially available micro-air vehicle to perform aerial sensing by tracking the terrain and movement of the dog in the outdoor space. The dogs were free to explore the space working at maximal speeds to complete a scent-based search-and-retrieval task. Throughout the experiment, the harness data was transferred to a base station via Wi-Fi in real-time. In this work, we also focused on testing the performance of a custom 3D electrode with application specific ergonomic improvements and adaptive filter processing techniques to recover as much electrocardiography data as possible during high intensity motion activity. We were able to recover and use 84% of the collected data where we observed a trend of heart rate generally increasing immediately after successful target localization. For tracking the dogs in the aerial video footage, we applied a state-of-the-art deep learning algorithm designed for online object tracking. Both qualitative and quantitative tracking results are very promising. This study presents an initial effort towards deployment of on-body and aerial sensors to monitor the working dogs and their environments during scent detection and search and rescue tasks in order to ensure their welfare, enable novel dog-machine interfaces, and allow for higher success rate of remote and automated task performance.

Effects of Salt-Induced Charge Screening on AOT Adsorption to the Planar and Nanoemulsion Oil-Water Interfaces.

Nanoemulsions, nanosized droplets of oil, are easily stabilized by interfacial electric fields from the adsorption of ionic surfactants. While mean-field theories can be used to describe the impact of these interfacial fields on droplet stability, the influence of these fields on the adsorption properties of ionic surfactants is not well-understood. In this work, we study the adsorption of the surfactant sodium dioctyl sulfosuccinate (AOT) at the nanoemulsion and planar oil-water interfaces and investigate how salt-induced charge-screening affects AOT adsorption. In the absence of salt, vibrational sum-frequency scattering spectroscopy measurements reveal the ΔGads and the maximum surface density is the same for AOT at the hexadecane nanoemulsion surface as at the planar hexadecane-H2O interface. Upon the addition of NaCl, an increase in AOT surface density is detected at both interfaces, indicating that repulsive electrostatic interactions between AOT monomers are the dominant force limiting surfactant adsorption at both interfaces. The bulky alkyl chains of AOT molecules cause our observations in this study to differ from those found in previous studies investigating the adsorption of linear-chain ionic surfactants to the nanoemulsion surface. These results provide necessary information for understanding factors limiting the adsorption of ionic surfactants to nanodroplet surfaces and highlight the need for further studies into the adsorption properties of more complex macromolecules at nanoemulsion surfaces.

Proper placement of the distal biceps tendon during repair improves supination strength--a biomechanical analysis.

BACKGROUND: Anatomic repair of the distal biceps tendon can be difficult to achieve. This study was designed to compare the effect of anatomic and nonanatomic repairs on forearm supination torque. A nonanatomic repair re-establishes the footprint radial and more anterior to the tuberosity apex, whereas an anatomic repair re-establishes the footprint ulnar and more posterior to the tuberosity apex. METHODS: Eight fresh frozen cadaver arms were surgically prepared and mounted on an elbow simulator. Controlled loads were applied to the long head and short head in positions of pronation, neutral, and supination. This was done with intact tendons and then repeated with repaired tendons that were repaired either anatomically (ulnar position) or nonanatomically (radial position). RESULTS: All anatomic repairs showed no difference compared with intact tendon measurements. In comparing anatomic and nonanatomic repairs, we found no differences in the supination torque when the forearm was in 45° of pronation. However, when the arm was in neutral rotation, we found that 15% less supination torque was generated by the nonanatomic repair. When the arm was tested in 45° of supination, we found that 40% less supination torque was generated in the nonanatomic repair (P = .01). CONCLUSION: This study supports the idea that an anatomic repair of the biceps tendon onto the ulnar side of the radial tuberosity is important. If the tendon is repaired too radially, the biceps will lose the cam effect and may not be able to generate full supination torque when the forearm is in neutral rotation or in supination.

Dynamic Duo: Vibrational Sum Frequency Scattering Investigation of pH-Switchable Carboxylic Acid/Carboxylate Surfactants on Nanodroplet Surfaces.

Surfactants containing pH-switchable, carboxylic acid moieties are utilized in a variety of environmental, industrial, and biological applications that require controlled stability of hydrophobic droplets in water. For nanoemulsions, kinetically stable oil droplets in water, surface adsorption of the anionic form of the carboxylic acid surfactant stabilizes the droplet, whereas a dominant surface presence of the neutral form leads to destabilization. Through the use of dynamic light scattering, ζ-potential, and vibrational sum frequency scattering spectroscopy (VSFSS), we investigate this mechanism and the relative surface population of the neutral and charged species as pH is adjusted. We find that the relative population of the two surfactant species at the droplet surface is distinctly different than their bulk equilibrium concentrations. The ζ-potential measurements show that the surface concentration of the charged surfactant stays nearly constant throughout the stabilizing pH range. In contrast, VSFSS shows that the neutral carboxylic acid form increasingly adsorbs to the surface with increased acidity. The spectral features of the headgroup vibrational modes confirm this behavior and go further to reveal additional molecular details of their adsorption. A significant hydrogen-bonding interaction occurs between the headgroups that, along with hydrophobic chain-chain interactions, assists in drawing more carboxylic acid surfactant to the interface. The charged surfactant provides the stabilizing force for these droplets, while the neutral surfactant introduces complexity to the interfacial structure as the pH is lowered. The results are significantly different than what has been found for the planar oil/water studies where stabilization of the interface is not a factor.

Accelerating water dissociation in bipolar membranes and for electrocatalysis.

Catalyzing water dissociation (WD) into protons and hydroxide ions is important both for fabricating bipolar membranes (BPMs) that can couple different pH environments into a single electrochemical device and for accelerating electrocatalytic reactions that consume protons in neutral to alkaline media. We designed a BPM electrolyzer to quantitatively measure WD kinetics and show that, for metal nanoparticles, WD activity correlates with alkaline hydrogen evolution reaction activity. By combining metal-oxide WD catalysts that are efficient near the acidic proton-exchange layer with those efficient near the alkaline hydroxide-exchange layer, we demonstrate a BPM driving WD with overpotentials of <10 mV at 20 mA·cm-2 and pure water BPM electrolyzers that operate with an alkaline anode and acidic cathode at 500 mA·cm-2 with a total electrolysis voltage of ~2.2 V.

A Smart Collar for Assessment of Activity Levels and Environmental Conditions for Guide Dogs.

This paper demonstrates the design and manufacturing of a smart and connected internet-of-things collar system for the collection of behavioral and environmental information from working canines. The environmental factors of ambient light, ambient temperature, ambient noise levels, barometric pressure and relative humidity are recorded by the smart collar system in addition to behavioral information about barking incidences and activity levels. The data are collected from the sensors and transmitted via Bluetooth to the handler's smartphone where the custom app also acquires GPS positioning using the on-board smartphone sensors. The stored data on the smartphone are uploaded to the IBM Cloud once the user is connected to a WiFi network. The low power design of the smart collar system permits it to be used continuously for 27 hours with a 290 mAh lithium polymer battery. The cost of the system is low enough to let the handlers have multiple collars and exchange it if needed or recharge it overnight when not in use. This system is currently being scaled up to be tested on hundreds of canine puppies by a preeminent guide dog school in the US. As a result, the design emphasis here has been on the cost and power reduction, comfortable ergonomics, user friendliness, and robustness of data streaming. We expect the system to provide continuous quantitative data for improving guide dog training programs in addition to contributing the well-being of other working dogs in the future.

A System for Assessment of Canine-Human Interaction during Animal-Assisted Therapies.

Animal-assisted therapies (AAT) are becoming increasingly common to help hospitalized patients, especially in oncology units. There is a critical need for methods and technologies that can enable a quantifiable understanding of AAT to objectively demonstrate its efficacy and improve its efficiency. In this paper, we present our preliminary efforts towards the development of wireless sensor systems to simultaneously detect the related behavioral (activity level, movement, stroking) and physiological signals (heart rate/variability) of humans and animals during their interaction. To detect heart rate, we tested two different techniques based on wearable or contactless electrocardiography. In this preliminary evaluation, we were able to assess these parameters successfully and identify the design challenges towards deployment of these systems in larger clinical studies.

Use of crowdsourcing for cancer clinical trial development.

Patient and physician awareness and acceptance of trials and patient ineligibility are major cancer clinical trial accrual barriers. Yet, trials are typically conceived and designed by small teams of researchers with limited patient input. We hypothesized that through crowdsourcing, the intellectual and creative capacity of a large number of researchers, clinicians, and patients could be harnessed to improve the clinical trial design process. In this study, we evaluated the feasibility and utility of using an internet-based crowdsourcing platform to inform the design of a clinical trial exploring an antidiabetic drug, metformin, in prostate cancer. Over a six-week period, crowd-sourced input was collected from 60 physicians/researchers and 42 patients/advocates leading to several major (eg, eligibility) and minor modifications to the clinical trial protocol as originally designed. Crowdsourcing clinical trial design is feasible, adds value to the protocol development process, and may ultimately improve the efficiency of trial conduct.

A straightforward means of coupling preparative high-performance liquid chromatography and mass spectrometry.

Flow splitting to a mass spectrometer is a common way of coupling a highly specific detector to preparative or semi-preparative high-performance liquid chromatography (HPLC) purification of combinatorial libraries, drug metabolites, and characterizable impurities. The sensitive mass spectrometer consumes only a small fraction of the analyte while providing online structure-specific detection, and its output can thus be used to trigger collection of the desired fraction. Coupling mass spectrometry to preparative HPLC is difficult due to the susceptibility of the detector to fouling under conditions of high analyte concentration or solute amount, or to changes in solvent composition. We report here on a device, the mass rate attenuator (MRA), which automatically produces split ratios over a range of 100:1 to 100 000:1 under programmable user control. The MRA is a flow-control device that periodically gates a small aliquot from one liquid stream into another. The design allows the user to set the frequency of the gating without interruption of the HPLC flow stream. The MRA also allows control of the volume of the aliquot that is transferred between the flow streams. This additional control, compared to passive splitting devices, facilitates optimization of the tubing connecting the separation, detection and collection events. We demonstrate that such optimization can reduce the volume of the collected fraction without compromising recovery, thus reducing the time spent in evaporating solvents to reclaim purified products.