A helium adsorption pump for temperatures between 0.71 and 1.2 K

The construction and method of working of a helium adsorption pump are described. The flux of helium-2 film can be suppressed by an appropriate construction, which permits it to reach temperatures down to 0.71 K. By total utilization of the pump's cross-section, temperatures from 1.2 K to 0.71 K remain constant for several hours with a precision of 0.001 K

Letter from Dr. K. Keck to [John Muir], 1875 Dec 15.

Aistershaim, Upper Austria,Dec. 15, 1875.Dear Sir:It is Mr. Sereno Watson, Cambridge, (Mass.) to whom I am owing the notice you might perhaps be willing to exchange botanical specimens with me. Allow me then to introduce myself to you as a zealous colleague in the scientia amabili to whom it would afford the highest satisfaction to enter in direct relations with you. I may state that I am in correspondence with many of our leading botanists, besides possessing a very rich herbarium and collecting myself a great number of plants. At all events, you may rely upon obtaining a full return. The transmission of our packages to the care of the Smithsonian. I shall be happy to have to this a reply in the affirmative.I am, with the highest consideration,Very truly yours,Dr. K. Keck

The effect of Maneb on implantation, fecundity rate and the thyroid activity in the rabbit

The fungicide Maneb is a member of the family of dithiocarbamates that is used in the control of the fungal diseases of plants. The purpose of this work is to examine the effect of Maneb on implantation and thyroid activity at doses of 5, 10 and 50 mg/kg/day by gavage for 10 days in the domestic female rabbit, Oryctolagus cuniculus. The rabbits were sacrificed on the 11th day of pregnancy. The results indicate an increase in the body weight in the treated female. An increase is also observed in the weightof liver in the treated females with a darker color. There is 50% of inhibition of implantation in the group treated with the higher dose (50 mg/kg/day) when compared with control rabbit. The inhibition of implantation by Maneb may be to due to hormonal imbalance

Neutralizing Antibody Response to Hepatitis C Virus

A critical first step in a “rational vaccine design” approach for hepatitis C virus (HCV) is to identify the most relevant mechanisms of immune protection. Emerging evidence provides support for a protective role of virus neutralizing antibodies, and the ability of the B cell response to modify the course of acute HCV infection. This has been made possible by the development of in vitro cell culture models, based on HCV retroviral pseudotype particles expressing E1E2 and infectious cell culture-derived HCV virions, and small animal models that are robust tools in studies of antibody-mediated virus neutralization. This review is focused on the immunogenic determinants on the E2 glycoprotein mediating virus neutralization and the pathways in which the virus is able to escape from immune containment. Encouraging findings from recent studies provide support for the existence of broadly neutralization antibodies that are not associated with virus escape. The identification of conserved epitopes mediating virus neutralization that are not associated with virus escape will facilitate the design of a vaccine immunogen capable of eliciting broadly neutralizing antibodies against this highly diverse virus

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Mutations in hepatitis C virus E2 located outside the CD81 binding sites lead to escape from broadly neutralizing antibodies but compromise virus infectivity.

Broadly neutralizing antibodies are commonly present in the sera of patients with chronic hepatitis C virus (HCV) infection. To elucidate possible mechanisms of virus escape from these antibodies, retrovirus particles pseudotyped with HCV glycoproteins (HCVpp) isolated from sequential samples collected over a 26-year period from a chronically infected patient, H, were used to characterize the neutralization potential and binding affinity of a panel of anti-HCV E2 human monoclonal antibodies (HMAbs). Moreover, AP33, a neutralizing murine monoclonal antibody (MAb) to a linear epitope in E2, was also tested against selected variants. The HMAbs used were previously shown to broadly neutralize HCV and to recognize a cluster of highly immunogenic overlapping epitopes, designated domain B, containing residues that are also critical for binding of viral E2 glycoprotein to CD81, a receptor essential for virus entry. Escape variants were observed at different time points with some of the HMAbs. Other HMAbs neutralized all variants except for the isolate 02.E10, obtained in 2002, which was also resistant to MAb AP33. The 02.E10 HCVpp that have reduced binding affinities for all antibodies and for CD81 also showed reduced infectivity. Comparison of the 02.E10 nucleotide sequence with that of the strain H-derived consensus variant, H77c, revealed the former to have two mutations in E2, S501N and V506A, located outside the known CD81 binding sites. Substitution A506V in 02.E10 HCVpp restored binding to CD81, but its antibody neutralization sensitivity was only partially restored. Double substitutions comprising N501S and A506V synergistically restored 02.E10 HCVpp infectivity. Other mutations that are not part of the antibody binding epitope in the context of N501S and A506V were able to completely restore neutralization sensitivity. These findings showed that some nonlinear overlapping epitopes are more essential than others for viral fitness and consequently are more invariant during earlier years of chronic infection. Further, the ability of the 02.E10 consensus variant to escape neutralization by the tested antibodies could be a new mechanism of virus escape from immune containment. Mutations that are outside receptor binding sites resulted in structural changes leading to complete escape from domain B neutralizing antibodies, while simultaneously compromising viral fitness by reducing binding to CD81

Action-derived molecular dynamics in the study of rare events

We present a practical method to generate classical trajectories with fixed initial and final boundary conditions. Our method is based on the minimization of a suitably defined discretized action. The method finds its most natural application in the study of rare events. Its capabilities are illustrated by non-trivial examples. The algorithm lends itself to straightforward parallelization, and when combined with molecular dynamics (MD) it promises to offer a powerful tool for the study of chemical reactions.Comment: 7 Pages, 4 Figures (3 in color), submitted to Phys. Rev. Let

Relationship tensions and mood: Adult children’s daily experience of aging parents’ stubbornness

This study examined middle‐aged individuals’ reports of parents’ behaviors commonly attributed to stubbornness. Middle‐aged adults (N = 192) completed a 7‐day diary reporting their mood and how often they felt their parents (N = 254) engaged in behaviors often described as “stubbornness” (insistent or risky). Thirty‐one percent of middle‐aged children reported insistent behaviors, and 17% reported risky behaviors by their parent(s). Daily reports of parent behaviors attributed to stubbornness were positively associated with parent–child relationship quality, parent functional limitations, and child neuroticism. Reports of perceived parent insistent behaviors were also associated with greater daily negative mood among adult children. Findings highlight the impact of adult children’s daily perceptions of parent behaviors commonly attributed to stubbornness on the individual and relationship.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142899/1/pere12229_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142899/2/pere12229.pd