Scorpion envenomation is a leading cause of morbidity and mortality among accidents caused by venomous animals. Major clinical manifestations that precede death after scorpion envenomation include heart failure and pulmonary edema. Here, we demonstrate that cardiac dysfunction and fatal outcomes caused by lethal scorpion envenomation in mice are mediated by a neuro-immune interaction linking IL-1 receptor signaling, prostaglandin E2, and acetylcholine release. IL-1R deficiency, the treatment with a high dose of dexamethasone or blockage of parasympathetic signaling using atropine or vagotomy, abolished heart failure and mortality of envenomed mice. Therefore, we propose the use of dexamethasone administration very early after envenomation, even before antiserum, to inhibit the production of inflammatory mediators and acetylcholine release, and to reduce the risk of death.

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Spatial orientation is a cognitive domain frequently impaired in Alzheimer's Disease and can be one of its earliest symptoms.Objective:This paper describes the results of tolerability, sense of presence and usability of two immersive virtual reality tasks for the assessment of spatial orientation, using VR headset in adults.Methods:31 healthy adults recruited from university and the local community performed two experimental immersive virtual reality tasks of spatial orientation: the SOIVET-Maze for the assessment of allocentric to egocentric spatial abilities and the SOIVET-Route for the assessment of spatial memory and landmark recognition. Participants completed questionnaires about sense of presence, cybersickness symptoms, technology use profile and motion sickness history. Usability measures were assessed by spontaneous feedback from participants.Results:All participants were able to understand the task instructions and how to interact with the system. Both tasks seemed to induce a strong sense of presence, as assessed by the Witmer and Singer Presence Questionnaires (M=128 and 143 for SOIVET-Maze and SOIVET-Route, respectively). The SOIVET-Route had a small numeric advantage over the SOIVET-Maze tolerability scores assessed by the Cybersickness Questionnaire (M=4.19, SD=5.576 and M=3.52, SD=6.418 for SOIVET-Maze and SOIVET-Route respectively). Also, there were no drop-outs on the SOIVET-Route due to tolerability issues, unlike the SOIVET-Maze, which had two drop-outs. However, this difference was not statistically significant (Z= -.901, p= 0.368, Wilcoxon signed-rank test).

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SHORT ABSTRACT We provide a reliable method for left anterior descending artery (LAD) ligation in a mouse model. This method is comparatively less invasive than other methods, involving endotracheal intubation, a left-sided thoracotomy approach, and thoracentesis. This method can be used as a model for both acute and chronic myocardial infarction (MI). LONG ABSTRACT Ischemic heart disease (IHD) or acute coronary syndrome (ACS) is one of the leading causes of death in the United States. IHD is characterized by reduced blood supply to the heart resulting in loss of oxygen to, and resultant necrosis of, the heart muscle. The MI model has gained popularity for its use as short-term ischemia-reperfusion model and long-term permanent ligation model. Below we describe a reliable method for permanent ligation of the LAD. With mouse genetic engineering technology becoming more advanced, and with an increasing availability of quality murine surgical instruments, the mouse has become a popular model for MI surgeries. Our surgical model incorporates the use of easily reversible anesthetic for rapid recovery of the mouse, minimally invasive endotracheal intubation without involving tracheotomy, and thoracentesis through the original thoracotomy site without creating an additional incision in the chest as is done in some other methods, to effectively remove excess blood and air from the chest cavity. This method is comparatively less invasive than other methods, which dramatically reduces surgical/post-surgical complications and mortality, and improves reproducibility.

Understanding how a classifier partitions a highdimensional input space and assigns labels to the parts is an important task in machine learning. Current methods for this task mainly use color-coded sample scatterplots, which do not explicitly show the actual decision boundaries or confusion zones. We propose an image-based technique to improve such visualizations. The method samples the 2D space of a dimensionality-reduction projection and color-code relevant classifier outputs, such as the majority class label, the confusion, and the sample density, to render a dense depiction of the high-dimensional decision boundaries. Our technique is simple to implement, handles any classifier, and has only two simple-to-control free parameters. We demonstrate our proposal on several real-world high-dimensional datasets, classifiers, and two different dimensionality reduction methods.

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This study evaluated the role of arterial baroreceptors in arterial pressure (AP) and pulse interval (PI) regulation in conscious C57BL mice. Male animals, implanted with catheters in a femoral artery and a jugular vein, were submitted to sino-aortic (SAD), aortic (Ao-X) or carotid sinus denervation (Ca-X), 5 days prior to the experiments. After basal recording of AP, the lack of reflex bradycardia elicited by administration of phenylephrine was used to confirm the efficacy of SAD, and cardiac autonomic blockade with methylatropine and propranolol was performed. The AP and PI variability were calculated in the time and frequency domains (spectral analysis/fast Fourier transform) with the spectra quantified in low-(LF; 0.25-1 Hz) and high-frequency bands (HF; 1-5 Hz). Basal AP and AP variability were higher after SAD, Ao-X or Ca-X than in intact mice. Pulse interval was similar among the groups, whereas PI variability was lower after SAD. Atropine elicited a slight tachycardia in control mice but did not change PI after total or partial denervation. The bradycardia caused by propranolol was higher after SAD, Ao-X or Ca-X compared with intact mice. The increase in the variability of AP was accompanied by a marked increase in the LF and HF power of the AP spectra after baroreceptor denervation. The LF and HF power of the PI were reduced by SAD and by Ao-X or Ca-X. Therefore, both sino-aortic and partial baroreceptor denervation in mice elicits hypertension and a remarkable increase in AP variability and cardiac sympathetic tonus. Spectral analysis showed an important contribution of the baroreflex in the power of LF oscillations of the PI spectra. Both sets of baroreceptors seem to be equally important in the autonomic regulation of the cardiovascular system in mice.