Place prioritization for biodiversity content

The prioritization of places on the basis of biodiversity content is part of any systematic biodiversity conservation planning process. The place prioritization procedure implemented in the ResNet software package is described. This procedure is primarily based on the principles of rarity and complementarity. Application of the procedure is demonstrated with two analyses, one data set consisting of the distributions of termite genera in Namibia, and the other consisting of the distributions of bird species in the Islas Malvinas/Falkland Islands. The attributes that data sets should have for the effective and reliable application of such procedures are discussed. The procedure used here is compared to some others that are also currently in use.     

A virus-like particle-based Epstein-Barr virus vaccine

Epstein-Barr Virus (EBV) is an ubiquitous human herpesvirus which can lead to infectious mononucleosis and different cancers. In immunocompromised individuals, this virus is a major cause for morbidity and mortality. Transplant patients who did not encounter EBV prior to immunosuppression frequently develop EBV-associated malignancies, but a prophylactic EBV vaccination might reduce this risk considerably. Virus-like particles (VLPs) mimic the structure of the parental virus but lack the viral genome. Therefore, VLPs are considered safe and efficient vaccine candidates. We engineered a dedicated producer cell line for EBV-derived VLPs. This cell line contains a genetically modified EBV genome which is devoid of all potential viral oncogenes but provides viral proteins essential for the assembly and release of VLPs via the endosomal sorting complex required for transport (ESCRT). Human B cells readily take up EBV-based VLPs and present viral epitopes in association with HLA molecules to T cells. Consequently, EBV-based VLPs are highly immunogenic and elicit humoral and strong CD8+ and CD4+ T cell responses in vitro and in a preclinical murine model in vivo. Our findings suggest that VLP formulations might be attractive candidates to develop a safe and effective polyvalent vaccine against EBV.     

Biosynthesis of 2-methyl-3-buten-2-ol emitted from needles of Pinus ponderosa via the non-mevalonate DOXP/MEP pathway of isoprenoid formation

The volatile hemiterpene 2-methyl-3-buten-2-ol (MBO) is emitted from the needles of several pine species from the Western United States and contributes to ozone formation in the atmosphere. It is synthesised enzymatically from dimethylallyl diphosphate (DMAPP). We show here that needles of Pinus ponderosa Laws. incorporated [1-2H1]-1-deoxy-D-xylulose (d-DOX) into the emitted MBO, but not D,L-[2-13C]mevalonic acid lactone. Furthermore, MBO emission was inhibited by fosmidomycin, a specific inhibitor of the second enzyme of the mevalonate-independent pathway of isopentenyl diphosphate and DMAPP formation, i.e. the 1-deoxy-D-xylulose 5-phosphate/2-C-methyl-D-erythritol 4-phosphate (DOXP/MEP) pathway. We thus prove that MBO emitted from needles of P. ponderosa is primarily formed via the DOXP/MEP pathway.     

Lack of Evolution Acceptance Inhibits Students’ Negotiation of Biology-based Socioscientific Issues

The purpose of this study was to explore science content used during college students’ negotiation of biology-based socioscientific issues (SSI) and examine how it related to students’ conceptual understanding and acceptance of biological evolution. The Socioscientific Issues Questionnaire (SSI-Q) was developed to measure depth of evolutionary science content use during SSI negotiation. Fifty-two upper level undergraduate biology and non-biology majors completed the SSI-Q and also the Conceptual Inventory of Natural Selection to assess evolution understanding and the Measure of Acceptance of the Theory of Evolution to appraise evolution acceptance. A multiple regression analysis tested for interaction effects between the predictor variables, evolution understanding and evolution acceptance. Results indicate that college students primarily use science concepts related to evolution to negotiate biology-based SSI including variation in a population, inheritance of traits, differential success, and change through time. The hypothesis that the extent of one’s acceptance of evolution is a mitigating factor in how science content related to evolution is evoked during SSI negotiation was supported by the data, in that such content was consistently evoked by participants for each of the three SSI scenarios used in this study.     

Simultaneous activation of T cells and accessory cells by a new class of intact bispecific antibody results in efficient tumor cell killing.

Bispecific Abs (bsAb) are promising immunological tools for the elimination of tumor cells in minimal residual disease situations. In principle, they target an Ag on tumor cells and recruit one class of effector cell. Because immune reactions in vivo are more complex and are mediated by different classes of effector cell, we argue that conventional bsAb might not yield optimal immune responses at the tumor site. We therefore constructed a bsAb that combines the two potent effector subclasses mouse IgG2a and rat IgG2b. This bispecific molecule not only recruits T cells via its one binding arm, but simultaneously activates FcgammaR+ accessory cells via its Fc region. We demonstrate here that the activation of both T lymphocytes and accessory cells leads to production of immunomodulating cytokines like IL-1beta, IL-2, IL-6, IL-12, and DC-CK1. Thus this new class of bsAb elicits excellent antitumor activity in vitro even without the addition of exogenous IL-2, and therefore represents a totally self-supporting system.     

Single nuclear pores visualized by confocal microscopy and image processing.

How nuclear pore complexes, mediating the transport of nucleic acids, proteins, and metabolites between cell nucleus and cytoplasm, are arranged in the nuclear envelope is essentially unknown. Here we describe a method combining high-resolution confocal imaging with image processing and pattern recognition to visualize single nuclear pore complexes (120 nm diameter), determine their relative positions with nanometer accuracy, and analyze their distribution in situ. The method was tested by means of a model system in which the very same sample areas could be imaged by confocal and electron microscopy. It was thus found that single fluorescent beads of 105 nm nominal diameter could be localized with a lateral accuracy of <20 nm and an axial accuracy of approximately 20 nm. The method was applied to digitonin-permeabilized 3T3 cells, whose nuclear pore complexes were fluorescently labeled with the anti-nucleoporin antibody mAb414. Stacks of optical sections were generated by confocal imaging at high resolution. Herein the nuclear pore complexes appeared as bright diffraction-limited spots whose centers were localized by fitting them by three-dimensional gaussians. The nearest-neighbor distribution function and the pair correlation function were calculated and found to agree well with those of randomly distributed hard cylinders of 138 +/- 17 nm diameter, but not with those of randomly distributed points or nonrandomly distributed cylinders. This was supported by a cluster analysis. Implications for the direct observation of the transport of single particles and molecules through individual nuclear pore complexes are discussed.     

Kinetics of 3-O-methyl glucose transport in red blood cells of newborn pigs

The glucose-permeable fetal red cells in the pig are entirely replaced by glucose-impermeable adult red cells within a month after birth. This study investigates the kinetic parameters of the glucose transport mechanism in newborn pig red cells in comparison with immature adult red cells (reticulocytes) as well as the fully matured adult erythrocytes. Influx and efflux of the nonmetabolizable 3-O-methyl glucose (3-O-M-G) in red cells of newborn pigs saturate at high substrate concentrations and exhibit typical Michaelis-Menten kinetics. Km values for efflux are 15.2 and 18.2 mM for 15 and 22 degrees C, respectively. Q10 computed between 10 and 26 degrees is 5.0. The energy of activation for the transport process is 34,000 cal mol-1. The effectiveness of hexoses in competing with 3-O-M-G in efflux is in the following order: D-glucose greater than D-mannose greater than D-fructose greater than D-galactose. Efflux of 3-O-M-G does not increase with 3-O-M-G or D-ribose in the medium and is reduced by 2,4-dinitroflurobenzene (DNFB), p-chloromercuriphenyl sufonic acid (PCMBS), and phloridzin. The reticulocytes are shown to possess a carrier-mediated transport but with a considerably lower transport rate. As the reticulocytes mature into normal red cells, the carrier transport mechanism is lost.