854 research outputs found
Dynamics of immersed molecules in superfluids
The dynamics of a molecule immersed in a superfluid medium are considered.
Results are derived using a classical hydrodynamic approach followed by
canonical quantization. The classical model, a rigid body immersed in
incompressible fluid, permits a thorough analysis; its effective Hamiltonian
generalizes the usual rigid-rotor Hamiltonian. In contrast to the free rigid
rotor, the immersed body is shown to have chaotic dynamics. Quantization of the
classical model leads to new and experimentally verifiable features. It is
shown, for instance, that chiral molecules can behave as "quantum propellers":
the rotational-translational coupling induced by the superfluid leads to a
nonzero linear momentum in the ground state. Hydrogen peroxide is a strong
candidate for experimental detection of this effect. The signature is a
characteristic splitting of rotational absorption lines. The 1_{01} --> 1_{10}
line in hydrogen peroxide, for example, is predicted to split into three lines
separated by as much as 0.01 cm^{-1}, which is about the experimental
linewidth.Comment: 10 pages, 3 figure
Association of influenza virus proteins with membrane rafts
Assembly and budding of influenza virus proceeds in the viral budozone, a
domain in the plasma membrane with characteristics of cholesterol
/sphingolipid-rich membrane rafts. The viral transmembrane glycoproteins
hemagglutinin (HA) and neuraminidase (NA) are intrinsically targeted to these
domains, while M2 is seemingly targeted to the edge of the budozone. Virus
assembly is orchestrated by the matrix protein M1, binding to all viral
components and the membrane. Budding progresses by protein- and lipid-mediated
membrane bending and particle scission probably mediated by M2. Here, we
summarize the experimental evidence for this model with emphasis on the raft-
targeting features of HA, NA, and M2 and review the functional importance of
raft domains for viral protein transport, assembly and budding, environmental
stability, and membrane fusion
Hemagglutinin-esterase-fusion (HEF) protein of influenza C virus
ABSTRACT Influenza C virus, a member of the Orthomyxoviridae family, causes flu-like disease but typically only with mild symptoms. Humans are the main reservoir of the virus, but it also infects pigs and dogs. Very recently, influenza C-like viruses were isolated from pigs and cattle that differ from classical influenza C virus and might constitute a new influenza virus genus. Influenza C virus is unique since it contains only one spike protein, the hemagglutinin-esterase-fusion glycoprotein HEF that possesses receptor binding, receptor destroying and membrane fusion activities, thus combining the functions of Hemagglutinin (HA) and Neuraminidase (NA) of influenza A and B viruses. Here we briefly review the epidemiology and pathology of the virus and the morphology of virus particles and their genome. The main focus is on the structure of the HEF protein as well as on its co- and post-translational modification, such as N-glycosylation, disulfide bond formation, S-acylation and proteolytic cleavage into HEF1 and HEF2 subunits. Finally, we describe the functions of HEF: receptor binding, esterase activity and membrane fusion
Forging Ahead in the Somerset Hills: ArchaeologicalDocumentation of an 18th-Century Bloomery Forge inBernardsville, New Jersey
This paper describes the results of a program of salvage archaeology at the Leddell Forge in Bernardsville, Somerset County, New Jersey. The site, which dates from the late-18th century, was discovered during landscaping activities on private property. Small-scale ironworks, such as this forge, were once a ubiquitous part of the cultural landscape in northern New Jersey, but today they are largely forgotten. With support from the Historical Society of the Somerset Hills and private donors, the forge remains were recorded. The Leddell Forge site contained exceptionally well-preserved wooden remains which provide new information about bloomery forge layout and construction. As seen at this site, archaeology can provide considerable new data about these fascinating early American industries and serve as a touchstone for learning about the entrepreneurs who owned them and the people who labored in them
Patriots, Tories, Inebriates, and hussies: The Historical Archaeology of the Abraham Staats House, as a Case Study in Microhistory
To modern suburbanites, life on a farm may seem hopelessly boring or, alternatively, charming and idyllic. Excavations at the Abraham Staats House in New Jersey’s Raritan Valley, just upriver from New Brunswick, provide a revealing glimpse of the dynamic and contentious lives of 18th- and 19th-century farmers. The Staats family, part of the early 18th-century Dutch migration to the Raritan Valley, saw their lives transformed by the Revolutionary War, the arrival of turnpike roads, the construction of the Delaware and Raritan Canal, the emancipation of slaves, the growth of the temperance movement, and family squabbles of Shakespearean proportions. Excavations at the Staats House undertaken by volunteers from the Friends of the Abraham Staats House, the Archaeological Society of New Jersey, and Monmouth University, combined with the rediscovery of long-forgotten diaries, deeds, wills, and court records, provide a richer glimpse into the complex realities of rural life in early New Jersey. Through the detailed intensive study, or microhistory, of this single household, local, regional, and national historical trends are revealed
Management consulting firms as institutional agents:strategies for creating and sustaining institutional capital
We classify the strategies by which management consultancies can create and sustain the institutional capital that makes it possible for them to extract competitive resources from their institutional context. Using examples from the German consulting industry, we show how localized competitive actions can enhance both individual firms’ positions, and also strengthen the collective institutional capital of the consulting industry thus legitimizing consulting services in broader sectors of society and facilitating access to requisite resources. Our findings counter the image of institutional entrepreneurship as individualistic, “heroic” action. We demonstrate how distributed, embedded actors can collectively shape the institutional context from within to enhance their institutional capital
Using Alphafold2 to Predict the Structure of the Gp5/M Dimer of Porcine Respiratory and Reproductive Syndrome Virus
Porcine reproductive and respiratory syndrome virus is a positive-stranded RNA virus of the family Arteriviridae. The Gp5/M dimer, the major component of the viral envelope, is required for virus budding and is an antibody target. We used alphafold2, an artificial-intelligence-based system, to predict a credible structure of Gp5/M. The short disulfide-linked ectodomains lie flat on the membrane, with the exception of the erected N-terminal helix of Gp5, which contains the antibody epitopes and a hypervariable region with a changing number of carbohydrates. The core of the dimer consists of six curved and tilted transmembrane helices, and three are from each protein. The third transmembrane regions extend into the cytoplasm as amphiphilic helices containing the acylation sites. The endodomains of Gp5 and M are composed of seven β-strands from each protein, which interact via β-strand seven. The area under the membrane forms an open cavity with a positive surface charge. The M and Orf3a proteins of coronaviruses have a similar structure, suggesting that all four proteins are derived from the same ancestral gene. Orf3a, like Gp5/M, is acylated at membrane-proximal cysteines. The role of Gp5/M during virus replication is discussed, in particular the mechanisms of virus budding and models of antibody-dependent virus neutralization
First case of ivermectin-induced severe hepatitis
Loiasis, caused by the filarial parasite Loa loa, is endemic in West and Central Africa. Ivermectin has been shown to be an effective treatment of loiasis. We report the case of a 20-year-old woman originally from Cameroon who was infected by the L. loa parasite and developed severe hepatitis, identified 1 month after a single dose of ivermectin. Liver biopsy showed intralobular inflammatory infiltrates, confluent necrosis and apoptosis, compatible with drug-induced liver disease. To our knowledge, this is the first case of ivermectin-induced severe liver disease published in the literatur
The Correlation of Dyslipidemia with the Extent of Coronary Artery Disease in the Multiethnic Study of Atherosclerosis.
BackgroundThe extent of coronary artery calcium (CAC) improves cardiovascular disease (CVD) risk prediction. The association between common dyslipidemias (combined hyperlipidemia, simple hypercholesterolemia, metabolic Syndrome (MetS), isolated low high-density lipoprotein cholesterol, and isolated hypertriglyceridemia) compared with normolipidemia and the risk of multivessel CAC is underinvestigated.ObjectivesTo determine whether there is an association between common dyslipidemias compared with normolipidemia, and the extent of coronary artery involvement among MESA participants who were free of clinical cardiovascular disease at baseline.MethodsIn a cross-sectional analysis, 4,917 MESA participants were classified into six groups defined by specific LDL-c, HDL-c, or triglyceride cutoff points. Multivessel CAC was defined as involvement of at least 2 coronary arteries. Multivariate Poisson regression analysis evaluated the association of each group with multivessel CAC after adjusting for CVD risk factors.ResultsUnadjusted analysis showed that all groups except hypertriglyceridemia had statistically significant prevalence ratios of having multivessel CAC as compared to the normolipidemia group. The same groups maintained statistical significance prevalence ratios with multivariate analysis adjusting for other risk factors including Agatston CAC score [combined hyperlipidemia 1.41 (1.06-1.87), hypercholesterolemia 1.55 (1.26-1.92), MetS 1.28 (1.09-1.51), and low HDL-c 1.20 (1.02-1.40)].ConclusionCombined hyperlipidemia, simple hypercholesterolemia, MetS, and low HDL-c were associated with multivessel coronary artery disease independent of CVD risk factors and CAC score. These findings may lay the groundwork for further analysis of the underlying mechanisms in the observed relationship, as well as for the development of clinical strategies for primary prevention
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