87 research outputs found
Origin of measles virus: divergence from rinderpest virus between the 11th and 12th centuries
Measles, caused by measles virus (MeV), is a common infection in children. MeV is a member of the genus Morbillivirus and is most closely related to rinderpest virus (RPV), which is a pathogen of cattle. MeV is thought to have evolved in an environment where cattle and humans lived in close proximity. Understanding the evolutionary history of MeV could answer questions related to divergence times of MeV and RPV
Mitral regurgitation late after manouguian's anulus enlargement and aortic valve replacement
AbstractJ Thorac Cardiovasc Surg 1998;115:727-
Studies on the ocular hypotensive effect of Diamox
In our studies on the hypotensive effect of Diamox by intravenous injection, we have arrived at the following conclusions. 1. Ocular tension falls and the flow of aqueous humor becomes sluggish. 2. Diamox inhibits the activity of carbonic anhydrase, and the concentrations
of HCO3-, K+, Cl- and glucose are markedly altered.
3. Protein increases both in blood and aqueous humor, but no change in protein fraction can be observed in blood.
4. Diamox in no way affects the metabolism. 5. It seems that Diamox brings about the change in the specific gravity
of blood, making the latter either more diluted or more concentrated. From these, we conclude that the mechanism of the loweing of ocular tension by Diamox seems to lie in the fact that it inhibits the activity of carbonic anhydrase, and that consequent alteration in the concentrations of HCO3- and other ions accompanied by the change in osmotic pressure as well as a slight decrease of water in tissue all bring about the fall in the ocular tension. However, Diamox seems to have nothing to do with
aqueous humor in so far as active transport or permeability are concerned.</p
Evolution of the M gene of the influenza A virus in different host species: large-scale sequence analysis
<p>Abstract</p> <p>Background</p> <p>Influenza A virus infects not only humans, but also other species including avian and swine. If a novel influenza A subtype acquires the ability to spread between humans efficiently, it could cause the next pandemic. Therefore it is necessary to understand the evolutionary processes of influenza A viruses in various hosts in order to gain better knowledge about the emergence of pandemic virus. The virus has segmented RNA genome and 7th segment, M gene, encodes 2 proteins. M1 is a matrix protein and M2 is a membrane protein. The M gene may be involved in determining host tropism. Besides, novel vaccines targeting M1 or M2 protein to confer cross subtype protection have been under development. We conducted the present study to investigate the evolution of the M gene by analyzing its sequence in different species.</p> <p>Results</p> <p>Phylogenetic tree revealed host-specific lineages and evolution rates were different among species. Selective pressure on M2 was stronger than that on M1. Selective pressure on M1 for human influenza was stronger than that for avian influenza, as well as M2. Site-by-site analyses identified one site (amino acid position 219) in M1 as positively selected in human. Positions 115 and 121 in M1, at which consensus amino acids were different between human and avian, were under negative selection in both hosts. As to M2, 10 sites were under positive selection in human. Seven sites locate in extracellular domain. That might be due to host's immune pressure. One site (position 27) positively selected in transmembrane domain is known to be associated with drug resistance. And, two sites (positions 57 and 89) locate in cytoplasmic domain. The sites are involved in several functions.</p> <p>Conclusion</p> <p>The M gene of influenza A virus has evolved independently, under different selective pressure on M1 and M2 among different hosts. We found potentially important sites that may be related to host tropism and immune responses. These sites may be important for evolutional process in different hosts and host adaptation.</p
Helmholtz: A Verifier for Tezos Smart Contracts Based on Refinement Types
27th International Conference, TACAS 2021, Held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2021, Luxembourg City, Luxembourg, March 27 - April 1, 2021Part of the Lecture Notes in Computer Science book series (LNTCS, volume 12652)A smart contract is a program executed on a blockchain, based on which many cryptocurrencies are implemented, and is being used for automating transactions. Due to the large amount of money that smart contracts deal with, there is a surging demand for a method that can statically and formally verify them. This tool paper describes our type-based static verification tool HELMHOLTZ for Michelson, which is a statically typed stack-based language for writing smart contracts that are executed on the blockchain platform Tezos. HELMHOLTZ is designed on top of our extension of Michelson’s type system with refinement types. HELMHOLTZ takes a Michelson program annotated with a user-defined specification written in the form of a refinement type as input; it then typechecks the program against the specification based on the refinement type system, discharging the generated verification conditions with the SMT solver Z3. We briefly introduce our refinement type system for the core calculus Mini-Michelson of Michelson, which incorporates the characteristic features such as compound datatypes (e.g., lists and pairs), higher-order functions, and invocation of another contract. HELMHOLTZ successfully verifies several practical Michelson programs, including one that transfers money to an account and that checks a digital signature
Helmholtz: A Verifier for Tezos Smart Contracts Based on Refinement Types
A smart contract is a program executed on a blockchain, based on which many cryptocurrencies are implemented, and is being used for automating transactions. Due to the large amount of money that smart contracts deal with, there is a surging demand for a method that can statically and formally verify them. This article describes our type-based static verification tool HELMHOLTZ for Michelson, which is a statically typed stack-based language for writing smart contracts that are executed on the blockchain platform Tezos. HELMHOLTZ is designed on top of our extension of Michelson’s type system with refinement types. HELMHOLTZ takes a Michelson program annotated with a user-defined specification written in the form of a refinement type as input; it then typechecks the program against the specification based on the refinement type system, discharging the generated verification conditions with the SMT solver Z3. We briefly introduce our refinement type system for the core calculus Mini-Michelson of Michelson, which incorporates the characteristic features such as compound datatypes (e.g., lists and pairs), higher-order functions, and invocation of another contract. HELMHOLTZ successfully verifies several practical Michelson programs, including one that transfers money to an account and that checks a digital signature
Clinical Result of Epicardial Pulmonary Vein Isolation (LAVIE) by Cryoablation as Concomitant Cardiac Operation and Clinical Application of New Ablation Device (KIRC-119 Infrared Coagulator) to Treat Atrial Fibrillation
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