BioScript: programming safe chemistry on laboratories-on-a-chip

This paper introduces BioScript, a domain-specific language (DSL) for programmable biochemistry which executes on emerging microfluidic platforms. The goal of this research is to provide a simple, intuitive, and type-safe DSL that is accessible to life science practitioners. The novel feature of the language is its syntax, which aims to optimize human readability; the technical contributions of the paper include the BioScript type system and relevant portions of its compiler. The type system ensures that certain types of errors, specific to biochemistry, do not occur, including the interaction of chemicals that may be unsafe. The compiler includes novel optimizations that place biochemical operations to execute concurrently on a spatial 2D array platform on the granularity of a control flow graph, as opposed to individual basic blocks. Results are obtained using both a cycle-accurate microfluidic simulator and a software interface to a real-world platform

Inter-step Height Variation of Stairways and Observations of Fall-related Events

INTRODUCTION: Variation in step height within a stairway could negatively impact safe stairway negotiation by decreasing step height predictability, and consequently, increasing stair users’ fall risk. Unfortunately, inter-stairway step height variability is common, particularly in older stairways, but its impact may be lessened by highlighting steps’ edges using high-contrast stripes on the top front edge of each step. Such contrast enhancement may draw greater attention to the steps’ edges and potentially enhance the precision of the edge’s estimated location. PURPOSE: To determine (1) if fall-related events are associated with greater inter-step height variation, and (2) if such fall-related events are reduced in the presence of contrast enhanced step edges compared to a control stairway. METHODS: Stair users were video recorded on two public stairways in a university building. One stairway had black vinyl strips applied to the step’s edges and black-and-white vertical stripes on the last and top steps’ faces. The stairway with striping was switched halfway through data collection. Each stair user recorded was coded for whether they experienced a fall-related event. RESULTS: Each flight of stairs had varying inter-step height (e.g., 14 mm for both West and East lower, 12 mm for the West upper, and 5 mm for the East upper). The flights that had 14 mm in inter-step height variation were associated with 80% of the fall-related events observed. 13 of 16 (81%) fall-related events occurred on the control stairway (no striping) compared to 3 of 16 (19%) on the high-contrast striping stairway. A Monte Carlo simulation was used to predict the probability of the distribution of fall-related events given our hypotheses. The distribution of fall-related events we observed between conditions likely did not occur by chance, P = 0.0358. CONCLUSION: These data support that a vision-based strategy (i.e., striping) may counteract fall-risk associated with high inter-step height variability. While the mechanisms of its action remain unclear, the high-contrast striping appears to have a positive impact on the incidence of fall-related events in the presence of high inter-step height variability

A Comparison of Mechanical and Electrical Wind-Powered Water Pumps

Worldwide, 783 million people do not have access to clean water; 319 million of them reside in Sub-Saharan Africa. In this region, the transportation of water from its source to its point-of-use can be arduous to complete using current methods. The men and women in developing communities must exert considerable effort to retrieve the few gallons of water they need to survive. Due to the lack of infrastructure and no external source of energy, new methods to transport the water must be capable of generating their own energy. The Archimedes Initiative has set out to identify a mechanically powered pump that performs as effectively as an electrical pump based on the following criteria: a 5-10L/min flow rate, 1-mile flow distance, and 150 ft. vertical head distance. The team will conduct research into the efficiency and performance of both hybrid and mechanical systems. At the project’s conclusion, The Archimedes Initiative plans to have a fully functioning wind-powered water pump capable of meeting the design criteria. The project is currently ongoing and much progress has been made towards developing preliminary designs and a viable prototype. After several iterations of design review and redesign, the team plans to begin construction of a prototype in January and testing is scheduled for February 2017. A fully functioning and usable prototype will be complete by the conclusion of the 2016-2017 school year

Explosive Hamstrings Strength Asymmetry Persists Despite Maximal Hamstring Strength Recovery Following Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autografts

PURPOSE: To investigate the differences in maximal (isometric and concentric peak torque) and explosive (rate of torque development (RTD)) hamstring and quadriceps strength symmetry between males and females during early- and late-phase rehabilitation after anterior cruciate ligament reconstruction (ACLR) using hamstring tendon (HT) autografts and to determine the interaction of time and sex on maximal and explosive strength symmetry. METHODS: A total of 38 female and 51 male participants were assessed during early (3–6 months post-operative) and late (7–12 months post-operative) phases of rehabilitation following ACLR. Maximal (concentric and isometric peak torque) and explosive (isometric RTD) hamstring and quadriceps strength were assessed and presented as limb symmetry index (LSI). RESULTS: Maximal concentric hamstrings asymmetry (Early: 86 ± 14; Late 92 ± 13; p = 0.005) as well as maximal concentric (Early, 73 ± 15; Late 91 ± 12; p < 0.001) and explosive (Early: 82 ± 30; Late: 92 ± 25; p = 0.03) quadriceps asymmetry decreased from early to late rehabilitation. However, there were no significant changes in maximal isometric quadriceps strength and explosive isometric hamstring strength in the same time period. Females had a larger asymmetry in maximal concentric (Females: 75 ± 17; Males: 81 ± 15; p = 0.001) and explosive (Females: 81 ± 32; Males: 89 ± 25; p = 0.01) quadriceps strength than males throughout rehabilitation. There were no sex differences in maximal and explosive hamstring strength. There were no sex by time interactions for any variables. CONCLUSION: Explosive hamstring strength asymmetry did not improve despite recovery of maximal hamstring strength during rehabilitation following ACLR with HT autografts. While sex did not influence strength recovery, females had larger maximal and explosive quadriceps strength asymmetry compared to males throughout rehabilitation following ACLR. LEVEL OF EVIDENCE: Level III SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00167-022-07096-y

A Smartphone-Based Tool for Rapid, Portable, and Automated Wide-Field Retinal Imaging.

Purpose:High-quality, wide-field retinal imaging is a valuable method for screening preventable, vision-threatening diseases of the retina. Smartphone-based retinal cameras hold promise for increasing access to retinal imaging, but variable image quality and restricted field of view can limit their utility. We developed and clinically tested a smartphone-based system that addresses these challenges with automation-assisted imaging. Methods:The system was designed to improve smartphone retinal imaging by combining automated fixation guidance, photomontage, and multicolored illumination with optimized optics, user-tested ergonomics, and touch-screen interface. System performance was evaluated from images of ophthalmic patients taken by nonophthalmic personnel. Two masked ophthalmologists evaluated images for abnormalities and disease severity. Results:The system automatically generated 100° retinal photomontages from five overlapping images in under 1 minute at full resolution (52.3 pixels per retinal degree) fully on-phone, revealing numerous retinal abnormalities. Feasibility of the system for diabetic retinopathy (DR) screening using the retinal photomontages was performed in 71 diabetics by masked graders. DR grade matched perfectly with dilated clinical examination in 55.1% of eyes and within 1 severity level for 85.2% of eyes. For referral-warranted DR, average sensitivity was 93.3% and specificity 56.8%. Conclusions:Automation-assisted imaging produced high-quality, wide-field retinal images that demonstrate the potential of smartphone-based retinal cameras to be used for retinal disease screening. Translational Relevance:Enhancement of smartphone-based retinal imaging through automation and software intelligence holds great promise for increasing the accessibility of retinal screening

Gravity Spy: Integrating Advanced LIGO Detector Characterization, Machine Learning, and Citizen Science

(abridged for arXiv) With the first direct detection of gravitational waves, the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) has initiated a new field of astronomy by providing an alternate means of sensing the universe. The extreme sensitivity required to make such detections is achieved through exquisite isolation of all sensitive components of LIGO from non-gravitational-wave disturbances. Nonetheless, LIGO is still susceptible to a variety of instrumental and environmental sources of noise that contaminate the data. Of particular concern are noise features known as glitches, which are transient and non-Gaussian in their nature, and occur at a high enough rate so that accidental coincidence between the two LIGO detectors is non-negligible. In this paper we describe an innovative project that combines crowdsourcing with machine learning to aid in the challenging task of categorizing all of the glitches recorded by the LIGO detectors. Through the Zooniverse platform, we engage and recruit volunteers from the public to categorize images of glitches into pre-identified morphological classes and to discover new classes that appear as the detectors evolve. In addition, machine learning algorithms are used to categorize images after being trained on human-classified examples of the morphological classes. Leveraging the strengths of both classification methods, we create a combined method with the aim of improving the efficiency and accuracy of each individual classifier. The resulting classification and characterization should help LIGO scientists to identify causes of glitches and subsequently eliminate them from the data or the detector entirely, thereby improving the rate and accuracy of gravitational-wave observations. We demonstrate these methods using a small subset of data from LIGO's first observing run.Comment: 27 pages, 8 figures, 1 tabl

Constitutively active Notch4 receptor elicits brain arteriovenous malformations through enlargement of capillary-like vessels

Arteriovenous (AV) malformation (AVM) is a devastating condition characterized by focal lesions of enlarged, tangled vessels that shunt blood from arteries directly to veins. AVMs can form anywhere in the body and can cause debilitating ischemia and life-threatening hemorrhagic stroke. The mechanisms that underlie AVM formation remain poorly understood. Here, we examined the cellular and hemodynamic changes at the earliest stages of brain AVM formation by time-lapse two-photon imaging through cranial windows of mice expressing constitutively active Notch4 (Notch4*). AVMs arose from enlargement of preexisting microvessels with capillary diameter and blood flow and no smooth muscle cell coverage. AV shunting began promptly after Notch4* expression in endothelial cells (ECs), accompanied by increased individual EC areas, rather than increased EC number or proliferation. Alterations in Notch signaling in ECs of all vessels, but not arteries alone, affected AVM formation, suggesting that Notch functions in the microvasculature and/or veins to induce AVM. Increased Notch signaling interfered with the normal biological control of hemodynamics, permitting a positive feedback loop of increasing blood flow and vessel diameter and driving focal AVM growth from AV connections with higher blood velocity at the expense of adjacent AV connections with lower velocity. Endothelial expression of constitutively active Notch1 also led to brain AVMs in mice. Our data shed light on cellular and hemodynamic mechanisms underlying AVM pathogenesis elicited by increased Notch signaling in the endothelium.American Heart Association (Grant 0715062Y)Tobacco-Related Disease Research Program (Predoctoral Fellowship 18DT-0009

The Interagency Process in Support & Stability Operations: Integrating and Aligning the Roles and Missions of Military and Civilian Agencies in Conflict and Post-Conflict Environments

This study addressed the support, stability, and reconstruction missions and tasks for the U.S. government in counterinsurgency warfare and suggests that interagency processes between civilian and military elements are in need of reform as a prerequisite for improving U.S. performance in complex counterinsurgencies. The project examined, assessed, and defined the nature of these problems in the context of historical case studies, policymaking, and current operations, especially in Iraq and Afghanistan, suggesting several ways to improve agency and interagency structures, as well as the education and training of core interagency civilian and military professionals. The findings were presented at a conference on the topic, hosted by the Bush School and the Strategic Studies Institute of the U.S. Army