Induction of assembly of MHC class I heavy chains with beta 2microglobulin by interferon-gamma.

Assembly of histocompatibility class I heavy chains with beta 2microglobulin (beta 2m) is known to be necessary for cell surface expression. Studies on the H-2 class I deficient but interferon-gamma (IFN-gamma) inducible fibrosarcoma BC2 and the lung carcinoma CMT 64.5 showed that after transfection with allogeneic H-2 class I genes the class I proteins are expressed, but only intracellularly and not on the cell surface. In spite of the presence of beta 2m in the cells no association of the transfected class I chain with beta 2m was observed. However, stimulation with IFN-gamma induced assembly and subsequent surface expression. These findings show that the assembly of class I heavy chains with beta 2m is not a spontaneous event but appears to be regulated by cellular mechanisms the nature of which is still unknown.     

Spatial preferences for invasion management: a choice experiment on controlling Ludwigia grandiflora in a French regional park

Biological Invasions - If individuals have spatially differentiated preferences for sites or areas impacted by an invasive alien species, effective management must take this heterogeneity into...     

Electrophoretic variation in muscle lactate dehydrogenase in Snake Valley cutthroat trout, Salmo clarki subsp.

1. Electrophoretic variation observed in muscle A group lactate dehydrogenase in Snake Valley cutthroat trout (Salmo clarki subsp.) suggested the presence of two variant alleles at the A1 locus and a null allele at the A2 locus. 2. The taxonomic status of the Snake Valley cutthroat trout was reviewed.     

Amino acid composition and endocrine control of vitelline envelope proteins in European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata)

The vitelline envelopes of European sea bass and gilthead sea bream are both composed of mainly four proteins with the molecular masses of 90, 52, 48, 45 kDa and 75, 50, 48, 44 kDa, respectively. Each protein has an amino acid composition that is characterized by a high content of proline and glutamic acid and a low content of cysteine, similar to the whole vitelline envelope of both species. The amino acid composition suggests that each protein is distinct but related to the other vitelline envelope proteins. The use of homologous antisera shows that both species have vitelline envelope proteins that are induced by estradiol-17β. As males of both species synthesize these proteins after treatment with estradiol-17β, the origin is not restricted to the ovaries. Vitellogenin of both Eurpoean sea bass and gilthead sea bream has the apparent molecular mass of 170 kDa. © 1995 Wiley-Liss, Inc.     

Adjoint multi-start-based estimation of cardiac hyperelastic material parameters using shear data

Cardiac muscle tissue during relaxation is commonly modeled as a hyperelastic material with strongly nonlinear and anisotropic stress response. Adapting the behavior of such a model to experimental or patient data gives rise to a parameter estimation problem which involves a significant number of parameters. Gradient-based optimization algorithms provide a way to solve such nonlinear parameter estimation problems with relatively few iterations, but require the gradient of the objective functional with respect to the model parameters. This gradient has traditionally been obtained using finite differences, the calculation of which scales linearly with the number of model parameters, and introduces a differencing error. By using an automatically derived adjoint equation, we are able to calculate this gradient more efficiently, and with minimal implementation effort. We test this adjoint framework on a least squares fitting problem involving data from simple shear tests on cardiac tissue samples. A second challenge which arises in gradient-based optimization is the dependency of the algorithm on a suitable initial guess. We show how a multi-start procedure can alleviate this dependency. Finally, we provide estimates for the material parameters of the Holzapfel and Ogden strain energy law using finite element models together with experimental shear data.     

Health‐related Research Ethics and Social Value: Antibiotic Resistance Intervention Research and Pragmatic Risks

We consider the implications for the ethical evaluation of research programs of two fundamental changes in the revised research ethical guideline of the Council for International Organizations of Medical Sciences. The first is the extension of scope that follows from exchanging “biomedical” for “health‐related” research, and the second is the new evaluative basis of “social value,” which implies new ethical requirements of research. We use the example of antibiotic resistance interventions to explore the need to consider the instances of what we term the pragmatic risks of such interventions to evaluate the social value of certain kinds of health‐related research. These (pragmatic) risks severely threaten the social value of interventions in every area where human and social responses significantly impact on their effectiveness. Thus, the social value of health‐related research needed to demonstrate its effectiveness depends on the extent and successful management of such risks. Research designed to take into account the management of pragmatic risks also gives rise to similar types of risks, and the potential for social value in light of those risks needs to be considered in ethical reviews based on the new guidelines. We argue that, to handle this new expanded task, the international system of research ethical review addressed by the guidelines needs institutional development.     

A new familial “fragile site” on chromosome 16 (q23-24). Cytogenetic and clinical considerations

A new familial fragile site at 16q23-24 is documented, and the clinical and cytogenetic data on three families and some individual patients are reported. The importance of differentiating this fragile site from that recognized previously at 16q22 is pointed out.