Sequence,expression, and chromosomal assignment of a human sperm outer dense fiber gene

Outer dense fibers (ODFs) are located on the outside of the axoneme in the midpiece and principal piece of the mammalian sperm tail and may help to maintain the passive elastic structures and elastic recoil of the sperm tail. We have identified and describe here a human gene that is homologous to the Mst(3)CGP gene family of Drosophila melanogaster and encodes an ODF protein of 241 amino acids. The transcribed region has a size of ?lkb and contains two exons of 416 bp and 406 bp, respectively, not including the 3′ untranslated region. The gene is expressed in testis but not in human spleen, kidney, or brain and resembles in this respect the expression of the Drosophila Mst(3)CGP gene family in the male germline. An antiserum raised against a synthetic peptide derived from the N-terminus of the encoded sequence identified a protein of ? 32 kDa in an extract of human sperm flagella. By Southern-blot analyses and in situ hybridization, the ODF gene was localized to band q22 of chromosome 8. The isolation of a human gene encoding a sperm tail protein may provide the ability to identify and investigate, on the molecular level, possible reasons for human male infertility that are dependent on flagellar disturbances. © 1993 Wiley-Liss, Inc.     

Living Organ Procurement from the Mentally Incompetent: The Need for More Appropriate Guidelines

With the case of Belgium as a negative example, this paper will evaluate the legitimacy of using mentally incompetents as organ sources. The first section examines the underlying moral dilemma that results from the necessity of balancing the principle of respect for persons with the obligation to help people in desperate need. We argue for the rejection of a radical utilitarian approach but also question the appropriateness of a categorical prohibition. Section two aims to strike a fair balance between the competing interests at stake and to define the conditions under which organ harvest from mentally incompetents might be morally acceptable. To this end, we morally assess the main requirements that have been put forward to allow organ removal from incompetent donors. We conclude that the current Belgian legislation is far too permissive and that national regulations that do not permit the harvest of non‐regenerable organs from mentally incompetents in exceptional circumstances are too restrictive. On the basis of this discussion, we propose a number of guiding principles for decision‐making in this area.     

What precision‐protein‐tuning and nano‐resolved single molecule sciences can do for each other

While innovations in modern microscopy, spectroscopy, and nanoscopy techniques have made single molecule observation a standard in many laboratories, the actual design of meaningful fluorescence reporter systems now hinders major scientific breakthroughs. Even though the field of chemical biology is supercharging the fluorescence toolbox, surprisingly few strategies exist that make the transition from model systems to biologically relevant applications. At the same time, the number of microscopy techniques is growing dramatically. We explain our view on how the impact of modern technologies is influenced not only by further hard‐ and software developments, but also by the availability and suitability of protein‐engineering tools. We identify how the largely independent research fields of chemical biology and fluorescence nanoscopy can influence each other to synergistically drive future technology that can visualize the localization, structure, and dynamics of molecular function without constraints.     

Building Materials in the Operational Phase

How sustainable are the various building materials, and what are the criteria for assessment? The scope of this article is to explore in what ways responsible and conscious use of materials can yield environmental benefits in buildings. In particular, it discusses how material properties related to thermal and hygroscopic mass can be utilized for achieving energy efficiency and good indoor air quality, and how these gains can be included into the context of life cycle assessment (LCA). A case study investigates and compares carbon impacts related to three design concepts for an exterior wall: (A) concrete/rock wool; (B) wood studs/wood fiber; and (C) wood studs/hemp lime. The thermal performance of concepts B and C are modeled to comply with concept A regarding both thermal transmittance (U‐value) and dynamic heat flow (Q_24h) using the design tool WUFI Pro. An environmental cost‐benefit analysis is then accomplished in four steps, regarding (1) manufacturing and transport loads, (2) carbon sequestration in plant‐based materials and recarbonation in concrete/lime, and (3 and 4) potentially reduced operational energy consumption caused by heat and moisture buffering. The input data are based on suggested values and effects found in the literature. The summarized results show that wall A has the highest embodied carbon and the lowest carbon storage and recarbonation effects, whereas wall C2 has the lowest embodied carbon and the highest carbon storage and recarbonation effects. Regarding buffering effects, wall A has the highest potential for thermal buffering, whereas wall C has the highest potential for moisture buffering.