Efficiencies and armature reactions of 500 volt shunt motors

Thesis (BS)--University of Illinois, 1898M

Micromechanical function of myofibrils isolated from skeletal and cardiac muscles of the zebrafish

The zebrafish is a potentially important and cost-effective model for studies of development, motility, regeneration, and inherited human diseases. The object of our work was to show whether myofibrils isolated from zebrafish striated muscle represent a valid subcellular contractile model. These organelles, which determine contractile function in muscle, were used in a fast kinetic mechanical technique based on an atomic force probe and video microscopy. Mechanical variables measured included rate constants of force development (kACT) after Ca2+ activation and of force decay (τREL−1) during relaxation upon Ca2+ removal, isometric force at maximal (Fmax) or partial Ca2+ activations, and force response to an external stretch applied to the relaxed myofibril (Fpass). Myotomal myofibrils from larvae developed greater active and passive forces, and contracted and relaxed faster than skeletal myofibrils from adult zebrafish, indicating developmental changes in the contractile organelles of the myotomal muscles. Compared with murine cardiac myofibrils, measurements of adult zebrafish ventricular myofibrils show that kACT, Fmax, Ca2+ sensitivity of the force, and Fpass were comparable and τREL−1 was smaller. These results suggest that cardiac myofibrils from zebrafish, like those from mice, are suitable contractile models to study cardiac function at the sarcomeric level. The results prove the practicability and usefulness of mechanical and kinetic investigations on myofibrils isolated from larval and adult zebrafish muscles. This novel approach for investigating myotomal and myocardial function in zebrafish at the subcellular level, combined with the powerful genetic manipulations that are possible in the zebrafish, will allow the investigation of the functional primary consequences of human disease–related mutations in sarcomeric proteins in the zebrafish model

Recruitment of the Major Vault Protein by InlK: A Listeria monocytogenes Strategy to Avoid Autophagy

L. monocytogenes is a facultative intracellular bacterium responsible for listeriosis. It is able to invade, survive and replicate in phagocytic and non-phagocytic cells. The infectious process at the cellular level has been extensively studied and many virulence factors have been identified. Yet, the role of InlK, a member of the internalin family specific to L. monocytogenes, remains unknown. Here, we first show using deletion analysis and in vivo infection, that InlK is a bona fide virulence factor, poorly expressed in vitro and well expressed in vivo, and that it is anchored to the bacterial surface by sortase A. We then demonstrate by a yeast two hybrid screen using InlK as a bait, validated by pulldown experiments and immunofluorescence analysis that intracytosolic bacteria via an interaction with the protein InlK interact with the Major Vault Protein (MVP), the main component of cytoplasmic ribonucleoproteic particules named vaults. Although vaults have been implicated in several cellular processes, their role has remained elusive. Our analysis demonstrates that MVP recruitment disguises intracytosolic bacteria from autophagic recognition, leading to an increased survival rate of InlK over-expressing bacteria compared to InlK− bacteria. Together these results reveal that MVP is hijacked by L. monocytogenes in order to counteract the autophagy process, a finding that could have major implications in deciphering the cellular role of vault particles

Testing the “read-across hypothesis” by investigating the effects of ibuprofen on fish

Supplementary data related to this article can be found at http:// dx.doi.org/10.1016/j.chemosphere.2016.08.041Human pharmaceuticals present in the environment have the potential to cause adverse effects on non-target organisms. The “read-across hypothesis” stipulates that pharmaceuticals will exhibit similar biological effects across species (e.g. human and fish) if the molecular target has been conserved and the effective drug concentrations are reached (Cmax). We tested this hypothesis by evaluating if ibuprofen, a non-selective inhibitor of prostaglandins and the cyclooxygenase (COX) enzyme, can mimic its primary effect in humans, on fish, at comparable plasma concentrations. The endpoints, “prostaglandin E metabolite” (PGEM) levels and the mRNA expression of COX (ptgs gene), were measured in the gills of control and exposed fathead minnows (Pimephales promelas), using enzyme-immunoassay and quantitative real-time PCR (qPCR). Fish were exposed, for 24-72 h, to measured water concentrations of 9 (n= 12), 370 (n= 40) and 470 μg ibuprofen/L (n= 12). Water and blood plasma concentrations were determined using LC-MS/MS. Results showed that PGEM levels in fish exposed to 370 and 470 μg ibuprofen/L were significantly decreased compared to control fish, when mean plasma ibuprofen concentrations were 1.8 to 5.6-fold below the Cmax. The plasma ibuprofen concentrations and PGEM levels varied greatly between individuals. In fish exposed to 9 μg ibuprofen/L, when the mean plasma ibuprofen concentration was 224-fold below Cmax, no change in PGEM levels was observed. These data provide evidence for the read-across hypothesis, but suggest establishing a direct dose-response between internal plasma and PGEM is difficult, and would require significantly larger numbers of fish to overcome the inter-individual variation.This work was supported by Biotechnology and Biological Sci- ences Research Council (BBSRC) Industrial CASE Partnership Stu- dentship BB/I53257X/1 with AstraZeneca Safety Health and Environment Research Programme

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

SULLE PECULIARITÀ DEL SISTEMA SEGNICO MIMICO-GESTUALE

La persona sorda non sente il mondo intorno a sé, bensì lo guarda e non può perciò rappresentarlo con la voce, organo strettamente dipendente dall’udito, ma può invece rappresentarlo con i gesti e con la mimica. Il mondo, sia quello circostante che quello interiore, si costituisce per la persona sorda mediante il canale visivo e si articola dunque in segni mimico-gestuali piuttosto che vocali. La peculiarità del sistema mimico-gestuale si misura sulla base dell’analisi dei quattro parametri manuali (il luogo dello spazio in cui avviene la configurazione manuale, la configurazione e il movimento delle mani, l’orientamento del palmo delle mani) e delle componenti non manuali di cui esso si compone. Ciascun segno si distingue da un altro per differenze oppositive tra uno o più di questi elementi che lo compongono. La struttura oppositiva che caratterizza la lingua delle persone sorde differisce in quanto la lingua dei sordi sfrutta il canale visivo anziché quello uditivo e si costituisce nella materia manuale, gestuale quindi, anziché in quella fonica. Nella costituzione del segno delle persone sorde, inoltre, le componenti non manuali non sono semplici elementi paralinguistici che accompagnano la semiosi enfatizzandola, come per le lingue vocali, bensì sono veri e propri elementi costitutivi del segno la cui carenza compromette la comprensione reciproca

From Craft to Nature: The Emergence of Natural Teleology

A teleological explanation is an explanation in terms of an end or a purpose. So saying that ‘X came about for the sake of Y’ is a teleological account of X. It is a striking feature of ancient Greek philosophy that many thinkers accepted that the world should be explained in this way. However, before Aristotle, teleological explanations of the cosmos were generally based on the idea that it had been created by a divine intelligence. If an intelligent power made the world, then it makes sense that it did so with a purpose in mind, so grasping this purpose will help us understand the world. This is the pattern of teleological explanation that we find in the Presocratics and in Plato. However, with Aristotle teleology underwent a change: instead of thinking that the ends were explanatory because a mind had sought to bring them about, Aristotle took the ends to operate in natural beings independently of the efforts of any creative intelligence. Indeed, he thought that his predecessors had failed to understand what was distinctive of nature, namely, that its ends work from the inside of natural beings themselves

Aristotle on the Matter for Birth, Life, and the Elements

This essay considers three case studies of Aristotle’s use of matter, drawn from three different scientific contexts: menstrual fluid as the matter of animal generation in the Generation of Animals, the living body as matter of an organism in Aristotle’s On the Soul (De Anima), and the matter of elemental transformation in Generation and Corruption. I argue that Aristotle conceives of matter differently in these treatises (1) because of the different sorts of changes under consideration, and (2) because sometimes he is considering the matter for one specific change, and sometimes the matter for all of a thing’s natural changes. My account allows me to explain some of the strange features that Aristotle ascribes to the matter for elemental transformation in Generation and Corruption II. These features were interpreted by later commentators as general features of all matter. I argue that they are a result of the specific way that Aristotle thinks about the transmutation of the elements