PVP1-The People's Ventilator Project: A fully open, low-cost, pressure-controlled ventilator research platform compatible with adult and pediatric uses

Mechanical ventilators are safety-critical devices that help patients breathe, commonly found in hospital intensive care units (ICUs)-yet, the high costs and proprietary nature of commercial ventilators inhibit their use as an educational and research platform. We present a fully open ventilator device-The People's Ventilator: PVP1-with complete hardware and software documentation including detailed build instructions and a DIY cost of $1,700 USD. We validate PVP1 against both key performance criteria specified in the U.S. Food and Drug Administration's Emergency Use Authorization for Ventilators, and in a pediatric context against a state-of-the-art commercial ventilator. Notably, PVP1 performs well over a wide range of test conditions and performance stability is demonstrated for a minimum of 75,000 breath cycles over three days with an adult mechanical test lung. As an open project, PVP1 can enable future educational, academic, and clinical developments in the ventilator space.

Real-time, low-latency closed-loop feedback using markerless posture tracking

The ability to control a behavioral task or stimulate neural activity based on animal behavior in real-time is an important tool for experimental neuroscientists. Ideally, such tools are noninvasive, low-latency, and provide interfaces to trigger external hardware based on posture. Recent advances in pose estimation with deep learning allows researchers to train deep neural networks to accurately quantify a wide variety of animal behaviors. Here, we provide a new DeepLabCut-Live! package that achieves low-latency real-time pose estimation (within 15 ms, >100 FPS), with an additional forward-prediction module that achieves zero-latency feedback, and a dynamic-cropping mode that allows for higher inference speeds. We also provide three options for using this tool with ease: (1) a stand-alone GUI (called DLC-Live! GUI), and integration into (2) Bonsai, and (3) AutoPilot. Lastly, we benchmarked performance on a wide range of systems so that experimentalists can easily decide what hardware is required for their needs.

Mice can learn phonetic categories

Speech is perceived as a series of relatively invariant phonemes despite extreme variability in the acoustic signal. To be perceived as nearly-identical phonemes, speech sounds that vary continuously over a range of acoustic parameters must be perceptually discretized by the auditory system. Such many-to-one mappings of undifferentiated sensory information to a finite number of discrete categories are ubiquitous in perception. Although many mechanistic models of phonetic perception have been proposed, they remain largely unconstrained by neurobiological data. Current human neurophysiological methods lack the necessary spatiotemporal resolution to provide it: speech is too fast, and the neural circuitry involved is too small. This study demonstrates that mice are capable of learning generalizable phonetic categories, and can thus serve as a model for phonetic perception. Mice learned to discriminate consonants and generalized consonant identity across novel vowel contexts and speakers, consistent with true category learning. A mouse model, given the powerful genetic and electrophysiological tools for probing neural circuits available for them, has the potential to powerfully augment a mechanistic understanding of phonetic perception.

Diets for Rearing the Ambrosia Beetle Xyleborus ferrugineus (Fabricius) in vitro

Female ambrosia beetles placed on media containing sucrose, yeast extract, casein, starch, wheat germ, cottonseed oil, salt mixture, agar, water and cacao sawdust or powdered cellulose excavated galleries, oviposited, and produced progeny that developed to maturity. Several generations have been raised in the laboratory on media inoculated with ambrosia fungi by the beetles.

Relevance of the popliteal angle to hamstring length in cerebral palsy crouch gait

The popliteal angle is a widely used clinical means of assessing hamstring length in cerebral palsy patients. The relevance of the popliteal angle as a measure of hamstring length was assessed in this prospective study. Sixteen patients with cerebral palsy with crouch gait had their conventional and modified popliteal angles measured by nine observers on two separate occasions. With use of the conventional and modified forms of the test, 74 and 70%, respectively, of the observed variability was inter-and intraobserver related. The range of SDs for each observer using the conventional test was 7.1-13.6 degrees (average 10.9 degrees ), and with use of the modified form of the test, the range was 6.3-4.2 degrees (average 10.5 degrees ). The maximum hamstring length of each subject during gait was determined by three-dimensional modelling of their lower limbs. The modified popliteal angle measurements of the most repeatable observer demonstrated an inverse relationship between modified popliteal angle and maximum hamstring length (p < 0.01) and muscle excursion (p < 0.01). Only 10 of 32 limbs had short medial hamstrings.

Estimating economic thresholds for pest control: an alternative procedure

An alternative methodology to determine profit maximizing economic thresholds is developed and illustrated. An optimization problem based on the main biological and economic relations involved in determining a profit maximizing economic threshold is first advanced. From it, a more manageable model of 2 nonsimultaneous reduced-from equations is derived, which represents a simpler but conceptually and statistically sound alternative. The model recognizes that yields and pest control costs are a function of the economic threshold used. Higher (less strict) economic thresholds can result in lower yields and, therefore, a lower gross income from the sale of the product, but could also be less costly to maintain. The highest possible profits will be obtained by using the economic threshold that results in a maximum difference between gross income and pest control cost functions.

W. Edwards Deming, quality analysis, and total behavior management

During the past 10 years, the inclusion of the word "quality" in descriptions of production methods, management approaches, educational systems, service system changes, and so forth, has grown exponentially. It appears that no new approach to any problem is likely to be given much consideration today without overt acknowledgment that some improvement in quality must be the outcome. The origins of the importance of quality are primarily rooted in the awakening recognition of the influence of W. Edwards Deming in the post-World War II restoration of Japanese industry. We provide a brief overview of Deming's approach to modernizing management methods and discuss recent criticisms from the field of organizational behavior management that his approach lacks emphasis on the role of reinforcement. We offer a different analysis of Deming's approach and relate its evolution to the contingencies of reinforcement for the behavior of consulting. We also provide an example of problem solving with Deming's approach in a social service setting familiar to many behavior analysts.

A program evaluation of classroom data collection with bar codes

A technology incorporating bar code symbols and hand-held optical scanners was evaluated for its utility for routine data collection in a special education classroom. A different bar code symbol was created for each Individualized Educational Plan objective, each type of response occurrence, and each student in the first author's classroom. These symbols were organized by activity and printed as data sheets. The teacher and paraprofessionals scanned relevant codes with scanners when the students emitted targeted behaviors. The codes, dates, and approximate times of the scans were retained in the scanner's electronic memory until they could be transferred by communication software to a computer file. The data from the computer file were organized weekly into a printed report of student performance using a program written with commercially available database software. Advantages, disadvantages, and costs of using the system are discussed.