Mechanisms and Prospects of Ischemic Tolerance Induced by Cerebral Preconditioning

In the brain, brief episodes of ischemia induce tolerance against a subsequent severe episode of ischemia. This phenomenon of endogenous neuroprotection is known as preconditioning-induced ischemic tolerance. The purpose of this review is to summarize the current state of knowledge about mechanisms and potential applications of cerebral preconditioning and ischemic tolerance. Articles related to the terms ischemic preconditioning and ischemic tolerance were systematically searched via MEDLINE/PubMed, and articles published in English related to the nervous system were selected and analyzed. The past two decades have provided interesting insights into the molecular mechanisms of this neuroprotective phenomenon. Although both rapid and delayed types of tolerance have been documented in experimental settings, the delayed type has been found to be more prominent in the case of neuronal ischemic tolerance. Many intracellular signaling pathways have been implicated regarding ischemic preconditioning. Most of these are associated with membrane receptors, kinase cascades, and transcription factors. Moreover, ischemic tolerance can be induced by exposing animals or cells to diverse types of endogenous and exogenous stimuli that are not necessarily hypoxic or ischemic in nature. These cross-tolerances raise the hope that, in the future, it will be possible to pharmacologically activate or mimic ischemic tolerance in the human brain. Another promising approach is remote preconditioning in which preconditioning of one organ or system leads to the protection of a different (remote) organ that is difficult to target, such as the brain. The preconditioning strategy and related interventions can confer neuroprotection in experimental ischemia, and, thus, have promise for practical applications in cases of vascular neurosurgery and endo-vascular therapy

The relationship between the Covid-19 media coverage and the Environmental, Social and Governance leaders equity volatility: a time-frequency wavelet analysis

We apply wavelet analyses to study how the social media coverage of the Covid-19 pandemic influenced the volatility of ESG (Environmental, Social and Governance) leaders indices encompassing World, USA, Europe, China, and Emerging Markets. We document intervals of low, medium, and high coherence between the Media Coverage Index and the price moves of the ESG Leaders indices. The low coherence intervals indicate the diversification potential of ESG investments during a systemic pandemic such as Covid-19. We document differences in the pattern exhibited by various geographical indices evidencing their potential role for designing cross-geography hedge strategies

Exploring the role of reactive oxygen species (ROS) in marine ecosystem health and function

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2022.With the rapid decline of coastal ecosystems such as coral reefs and seagrasses, it is crucial to better understand the health of these ecosystem to prevent future loss. Reactive oxygen speices (ROS), such as superoxide and hydrogen peroxide, play an underappreciated role in both organism health and ecosystem biogeochemical cycles. This thesis lays the foundation to measure and identify ROS production by coral in situ and through genomic analysis while also highlighting the important role that ROS can play within biogeochemical cycling within seagrass ecosystems. To measure in situ extracellular superoxide, we develop the first DIver-operated Submersible Chemiluminescent sensOr (DISCO), enabling high resolution, non-invasive measurements in real time. We further refine DISCO by making it more compact, user-friendly, adaptable, and robust, enabling measurements of superoxide across a diversity of environments. Using DISCO, I observe species-specific variation in extracellular superoxide concentrations associated with healthy coral. Despite these variations across species, bioinformatic analysis of coral proteins reveal that nearly all coral species have the extracellular superoxide-producing enzyme NADPH oxidase (NOX), and thus the genetic potential to produce extracellular superoxide. This suggests that coral species likely exhibit differential NOX regulation and expression as a function of physiological responses to external stressors, which may play a role in coral immunity. I then turn to seagrass ecosystems, where I observe rapid hydrogen peroxide production and decay through predominantly reductive pathways. This has implications on the environmental redox state and biogeochemical cycling, impacting the ecosystem services that seagrasses provide to marine environments and coastal communities. Overall, this thesis highlights the potential role that ROS may be playing in organism and ecosystem health and lays the groundwork to further develop ROS as a tool to protect these coastal ecosystems against further degradation.Funding for this work was provided by the following grants: NSF GRFP (2016230168), Schmidt Marine Technology Partners (G-1801-57385 andG-2010-59878), WHOI Ocean Ventures Fund (2020 and 2021), and the MIT Wellington and Irene Loh Fund Fellowship (4000111995)

1967-1968 Problems in Legal Education

Six problems in legal education, much discussed recently, were posed by the Editors of this Review to leading legal educators. These questions were and are frankly difficult and controversial, but their answers are important to our system of legal education and to our society. Capsule answers given by these distinguished legal educators are believed to be interesting and significant. Each is a personal rather than a representative opinion. Brief answers such as these, of course, are not expected to be, nor do they pretend to be, complete or profound. Their purpose is to indicate succinctly the approach of outstanding American opinion makers to difficult policy problems of legal education

1967-1968 Problems in Legal Education

Six problems in legal education, much discussed recently, were posed by the Editors of this Review to leading legal educators. These questions were and are frankly difficult and controversial, but their answers are important to our system of legal education and to our society. Capsule answers given by these distinguished legal educators are believed to be interesting and significant. Each is a personal rather than a representative opinion. Brief answers such as these, of course, are not expected to be, nor do they pretend to be, complete or profound. Their purpose is to indicate succinctly the approach of outstanding American opinion makers to difficult policy problems of legal education

Rational design of the midship section structure of longitudinally framed tankers

http://www.archive.org/details/rationaldesignof00grabU.S. Coast Guard (U.S.C.G.) authors

Design optimization of a submersible chemiluminescent sensor (DISCO) for improved quantification of reactive oxygen species (ROS) in surface waters

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Grabb, K., Pardis, W., Kapit, J., Wankel, S., Hayden, E., & Hansel, C. Design optimization of a submersible chemiluminescent sensor (DISCO) for improved quantification of reactive oxygen species (ROS) in surface waters. Sensors, 22(17), (2022): 6683, https://doi.org/10.3390/s22176683.Reactive oxygen species (ROS) are key drivers of biogeochemical cycling while also exhibiting both positive and negative effects on marine ecosystem health. However, quantification of the ROS superoxide (O2−) within environmental systems is hindered by its short half-life. Recently, the development of the diver-operated submersible chemiluminescent sensor (DISCO), a submersible, handheld instrument, enabled in situ superoxide measurements in real time within shallow coral reef ecosystems. Here, we present a redesigned and improved instrument, DISCO II. Similar to the previous DISCO, DISCO II is a self-contained, submersible sensor, deployable to 30 m depth and capable of measuring reactive intermediate species in real time. DISCO II is smaller, lighter, lower cost, and more robust than its predecessor. Laboratory validation of DISCO II demonstrated an average limit of detection in natural seawater of 133.1 pM and a percent variance of 0.7%, with stable photo multiplier tube (PMT) counts, internal temperature, and flow rates. DISCO II can also be optimized for diverse environmental conditions by adjustment of the PMT supply voltage and integration time. Field tests showed no drift in the data with a percent variance of 3.0%. Wand tip adaptations allow for in situ calibrations and decay rates of superoxide using a chemical source of superoxide (SOTS-1). Overall, DISCO II is a versatile, user-friendly sensor that enables measurements in diverse environments, thereby improving our understanding of the cycling of reactive intermediates, such as ROS, across various marine ecosystems.The development and verification of DISCO was funded by Schmidt Marine Technology Partners (G-2010-59878 to C.M.H., S.D.W. and J.K.). This research was further supported, in part, by grants from NSF GRFP (2016230168 to K.C.G.), WHOI Ocean Ventures Fund (2020 and 2021 to K.C.G.), and the MIT Wellington and Irene Loh Fund Fellowship (4000111995 to K.C.G.)

Cellular haemangioma

Light and electron microscopic studies were conducted on the immature vascular tumors of two infants, containing various stages of differentiation of the blood vessels and both benign haemangioendotheliomas and haemangiopericytomas. We were able to confirm the existance of two kinds of hyperplastic, immature cells i.e. endothelial cells and pericytes in the same tumor. Presence of crystalloid inclusions in the endothelial cells and absence of the Weibel-Palade bodies, as well as a deficiency in factor VIII-related antigen and no tissue fibrinolytic activity, suggested that the endothelial cells in these lesions were immature. Electron microscopic studies appear more decisive in the diagnosis of heterogenous cellular vascular tumors than light microscopy and if available should be used to aid in the final diagnosis. The authors propose that the term cellular haemangioma would be more appropriate in describing this vascular entity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47515/1/428_2004_Article_BF00428503.pd

Leptomeningeal Dissemination of a Low-Grade Brainstem Glioma without Local Recurrence

It is rare for low-grade gliomas to disseminate to the leptomeninges. However, low-grade gliomas with dissemination to the leptomeninges have been occasionally reported in children, and have generally been associated with local recurrence. A 16-year-old boy sought evaluation for diplopia and gait disturbance. A brain magnetic resonance imaging (MRI) revealed pontine mass, which was proved to be fibrillary astrocytoma on biopsy, later. Radiation therapy (5400 cGy) was given and the patient's symptoms were improved. He was followed-up radiologically for brain lesion. Seven months after diagnosis he complained of back pain and gait disturbance. A brain MRI showed a newly-developed lesion at the left cerebellopontine angle without an interval change in the primary lesion. A spinal MRI demonstrated leptomeningeal dissemination of the entire spine. Radiation therapy (3750 cGy) to the spine, and adjuvant chemotherapy with a carboplatin plus vincristine regimen were administered. However, he had a progressive course with tumoral hemorrhage and expired 13 months after diagnosis. We report an unusual case of a low-grade brainstem glioma with spinal dissemination, but without local recurrence, and a progressive course associated with hemorrhage