Novel Application of a Force Sensor during Sit-to-Stands to Measure Dynamic Cerebral Autoregulation Onset

Purpose: Current sit-to-stand methods measuring dynamic cerebral autoregulation (dCA) do not capture the precise onset of the time delay (TD) response. Reduced sit-to-stand reactions in older adults and individuals post-stroke could inadvertently introduce variability, error, and imprecise timing. We applied a force sensor during a sit-to-stand task to more accurately determine how TD before dCA onset may be altered. Methods: Middle cerebral artery blood velocity (MCAv) and mean arterial pressure (MAP) were measured during two sit-to-stands separated by 15 minutes. Recordings started with participants sitting on a force-sensitive resistor for 60 seconds, then asked to stand for two minutes. Upon standing, the force sensor voltage immediately dropped and marked the exact moment of arise-and-off (AO). Time from AO until an increase in cerebrovascular conductance (CVC = MCAv/MAP) was calculated as TD. Results: We tested the sensor in 4 healthy young adults, 2 older adults, and 2 individuals post-stroke. Healthy young adults stood quickly and the force sensor detected a small change in TD compared to classically estimated AO, from verbal command to stand. When compared to the estimated AO, older adults had a delayed measured AO and TD decreased up to ~50% while individuals post-stroke had an early AO and TD increased up to ~14%. Conclusion: The transition reaction speed during the sit to stand has the potential to influence dCA metrics. As observed in the older adults and participants with stroke, this response may drastically vary and influence TD.

Optimization of Complete Rat Heart Decellularization Using Artificial Neural Networks

Whole organ decellularization techniques have facilitated the fabrication of extracellular matrices (ECMs) for engineering new organs. Unfortunately, there is no objective gold standard evaluation of the scaffold without applying a destructive method such as histological analysis or DNA removal quantification of the dry tissue. Our proposal is a software application using deep convolutional neural networks (DCNN) to distinguish between different stages of decellularization, determining the exact moment of completion. Hearts from male Sprague Dawley rats (n = 10) were decellularized using 1% sodium dodecyl sulfate (SDS) in a modified Langendorff device in the presence of an alternating rectangular electric field. Spectrophotometric measurements of deoxyribonucleic acid (DNA) and total proteins concentration from the decellularization solution were taken every 30 min. A monitoring system supervised the sessions, collecting a large number of photos saved in corresponding folders. This system aimed to prove a strong correlation between the data gathered by spectrophotometry and the state of the heart that could be visualized with an OpenCV-based spectrometer. A decellularization completion metric was built using a DCNN based classifier model trained using an image set comprising thousands of photos. Optimizing the decellularization process using a machine learning approach launches exponential progress in tissue bioengineering research.

Integrated Relaxation Pressure Classification and Probe Positioning Failure Detection in High-Resolution Esophageal Manometry Using Machine Learning

High-resolution esophageal manometry is used for the study of esophageal motility disorders, with the help of catheters with up to 36 sensors. Color pressure topography plots are generated and analyzed and using the Chicago algorithm a final diagnosis is established. One of the main parameters in this algorithm is integrated relaxation pressure (IRP). The procedure is time consuming. Our aim was to firstly develop a machine learning based solution to detect probe positioning failure and to create a classifier to automatically determine whether the IRP is in the normal range or higher than the cut-off, based solely on the raw images. The first step was the preprocessing of the images, by finding the region of interest—the exact moment of swallowing. Afterwards, the images were resized and rescaled, so they could be used as input for deep learning models. We used the InceptionV3 deep learning model to classify the images as correct or failure in catheter positioning and to determine the exact class of the IRP. The accuracy of the trained convolutional neural networks was above 90% for both problems. This work is just the first step in fully automating the Chicago Classification, reducing human intervention.

CRITICAL SHIFTING WINDOW IN SWITCHABLE ROCKER FINGER FOLLOWER

A valvetrain including switchable rocker finger follower is capable of discrete switching between two modes (two cam profiles). The exact moment when switching occurs is called crossover point and this paper reviews the factors that cause the shift of the crossover point from its nominal design position. The range where crossover point can shift is called critical shifting window and its size and factors influencing it will be adressed.

THE DYNAMICS OF LUNG HISTOPATHOLOGY IN ACUTE BACLOFEN POISONING

Baclofen (sold under the name Baclosan©, Lioresal©) is a muscle relaxant. This drug is chemically different from other muscle relaxants. Due to its pronounced psychotropic effect the drug is often a subject of abuse especially among young people. The article deals with the dynamics of lung histopathology in acute baclofen poisoning. Experimental studies were performed on 15 Wistar rats. The animals were divided into 3 groups (the controls and two experimental groups). The controls included 5 intact rats. Each experimental group included 5 animals. Both groups were treated with baclofen at a dosage of 85 mg/kg. The duration of the experiment was 3 and 24 hours, respectively. We revealed a complex of pathological changes in the lungs of the rats. There were circulatory disorders in all the elements of the microcirculatory bed, areas of emphysema, atelectasis and dystelectasis, WBC infiltration of intralveolar septa and their thickening due to edema. The changes were even more severe 24 hours after the drug administration. These results along with the results of chemical analysis will be useful in establishing the fact of baclofen intoxication and the exact moment of the intoxication.

In Tribute to Stefan Kunz

We do not always remember the exact moment in which we first met our friends [...]

Commentary on the Decision of the Supreme Administrative Court of 13 November 2013, II OZ 974/13 (LEX no. 1398284)

The thesis of the commented judgement concerns issues which are significant in the practice of examining an application in the course of administrative court proceedings regarding a request for reinstatement of the deadline. The first is a need to settle the beginning of the term for submitting such a request, the second – the method of examining the application for reinstatement of the deadline in the event of the impossibility to determine whether the deadline for its submission has been met. In the jurisprudence, it is consonantly assumed that the formal condition of an application for the reinstatement of the deadline is that the circumstances justifying the admissibility of the application are plausible due to the observance of the one-week deadline for its submission from the date of expiration of the cause of the deadline failure. According to Art. 49 § 1 of the Act of 30 August 2002 – Law on proceedings before administrative courts, if the letter of a party cannot receive the correct course due to failure to observe formal conditions, the chairman shall request the party to supplement or correct it within seven days under pain of leaving the letter unprocessed. The Supreme Administrative Court reasonably decided that if the content of the application cannot infer an exact moment in which the cause of the deadline failure ceased to exist, it should be examined on the merits. Equally, there are no grounds for rejecting the application as belated, based on Art. 88 of the Law on proceedings before administrative courts, because the fact of submitting the application after the deadline cannot be presumed.

Hazardous Duty: Investigating Resistance to Police at the Point of Arrest Among Incarcerated Military Veterans

The link between military service and crime has been a subject of investigation for several decades. Although research has examined the likelihood of arrest, incarceration, and recidivism across military cohorts, relatively little is known about the circumstances surrounding police contact and suspect behavior at the exact moment of arrest. This is a critical oversight given that what transpires during an arrest can have a marked impact on downstream criminal justice outcomes, including access to diversionary programming like veterans treatment courts. Using a nationally representative survey of prison inmates, this study analyzes veteran and nonveteran self-reports of their arrest controlling for a host of relevant demographic, mental health, and criminal history variables. Findings indicate that veterans are significantly less likely to resist the police at arrest. These results provide further support to the sentiment that military culture and training can have a lasting behavioral influence on those who experience it.