The Power of the Picture: How Narrative Film Captures Attention and Disrupts Goal Pursuit

Narrative transportation is described as a state of detachment that arises when one becomes immersed in the narrative of a story. Participants viewed either an intact version of an engaging 20 min film, “Bang You’re Dead!,” (1961) by Alfred Hitchcock (contiguous condition), or a version of the same film with scenes presented out of order (noncontiguous condition). In this latter condition, the individual scenes were intact but were presented out of chronological order. Participants were told a cover story that we were interested in the amount of gun violence depicted in films. Both groups were given the goal to remember to lift their hand every time they heard the word “gun” spoken during the film. Results revealed that participants were significantly less likely to remember to execute their goal in the contiguous condition, presumably because this narrative transported viewers’ attention and thereby “hijacked” processing resources away from internal goals.     

Isolation and characterization of the plasma membrane from the yeast Pichia pastoris

Despite similarities of cellular membranes in all eukaryotes, every compartment displays characteristic and often unique features which are important for the functions of the specific organelles. In the present study, we biochemically characterized the plasma membrane of the methylotrophic yeast Pichia pastoris with emphasis on the lipids which form the matrix of this compartment. Prerequisite for this effort was the design of a standardized and reliable isolation protocol of the plasma membrane at high purity. Analysis of isolated plasma membrane samples from P. pastoris revealed an increase of phosphatidylserine and a decrease of phosphatidylcholine compared to bulk membranes. The amount of saturated fatty acids in the plasma membrane was higher than in total cell extracts. Ergosterol, the final product of the yeast sterol biosynthetic pathway, was found to be enriched in plasma membrane fractions, although markedly lower than in Saccharomyces cerevisiae. A further characteristic feature of the plasma membrane from P. pastoris was the enrichment of inositol phosphorylceramides over neutral sphingolipids, which accumulated in internal membranes. The detailed analysis of the P. pastoris plasma membrane is discussed in the light of cell biological features of this microorganism especially as a microbial cell factory for heterologous protein production.     

In vitro dynamics of chromatin organization and migration

The organization of eukaryotic chromatin is not static but changes as a function of cell status during processes such as proliferation, differentiation, and migration. DNA quantification has not been used extensively to investigate chromatin dynamics in combination with cellular migration. In this context, an optimized DNA-specific, nonperturbant method has been developed for studying chromatin organization, using the fluorescent vital bisbenzimidazole probe Hoechst 33342: this property has been described by Hamori et al. (1980). Computer-assisted image analysis was used to follow migratory activity and chromatin organization of L929 fibroblasts during in vitro wound healing. Cell movements were analyzed using an optical flow technique, which consists in the calculation of the velocity field of cells and nuclear movements in the frame. This system allows the correlation of cell migration and position in the cell cycle. It makes it possible to study chromatin dynamics using a quantitative analysis of nuclear differentiation reorganization (nuclear texture) and to correlate this with migration characteristics. The present system would be of interest for studying cell-extracellular matrix interactions using differing substrates, and also the migratory response to chemotactic factors. Such a model is a prerequisite for gaining better understanding of drug action.     

Genetically controlled differences in the effects of chlormequat on tetraploid wheat (Triticum turgidum)

Two crosses between Triticum turgidum wheat lines differing in their response to chlormequat (CCC) were tested. In the F₂ population of one cross, which was segregating for the Rht1 dwarfing allele, each plant was cloned by separation of two tillers, one of which was treated with CCC. The tall (rht1/rht1) and the intermediate (Rht1/rht1) genotypes showed a greater response to CCC than the semi-dwarf (Rht1/Rht1) genotype, as expressed by culm length and date of ear emergence. The F₃ families of another cross and their two semi-dwarf parents were grown in a three-replicated field test in paris of rows, one of which was treated with CCC. In one of the parents and in 1/4 of the F₃ families CCC induced a wide-angled tiller growth, suggesting a monogenic control of this growth habit in response to CCC.Based on an M.Sc. thesis presented by the senior author to the Faculty of Agriculture of The Hebrew University of Jerusalem.     

Transformation of Penicillium chrysogenum by a vector containing a mitochondrial origin of replication

Summary In order to establish a transformation system for P. chrysogenum autonomously replicating vectors were constructed using mitochondrial DNA sequences from the fungus. A physical map of the mt DNA of a production strain was established using ten different restriction enzymes. Unexpectedly, the mt DNA of this strain proved to be significantly smaller than that of a second strain from a culture collection (27 kb versus 49 kb). Various fragments representing about 71% of the 27 kb mt DNA were cloned and, at first, preselected for replicating activity in an intermediate host (Saccharomyces cerevisiae). Two of these fragments also promoted autonomous replication in P. chrysogenum, which was confirmed by isolation of bulk DNA and transfer into E. coli. For selection of transformants in P. chrysogenum the prokaryotic kanamycin resistance gene was used which increased about twofold the resistance against G418. Present address: Institut für Biotechnologie, Fachgebiet Mikrobiologie, Techn. Universität Berlin, Seestr. 13, D-1000 Berlin 65     

Predicting genotypes at loci for autosomal recessive disorders using linked genetic markers: application to Wilson's disease

Summary Recently, the Wilson's disease locus (WND) has been mapped to the long arm of chromosome 13. We have analyzed segregation of serveral chromosome 13 markers flanking the WND locus and used multipoint linkage analysis to determine the most likely WND genotype of each of 57 unaffected individuals in 5 Wilson's disease families. Approximately 46% of these could be classified as carrier (heterozygote), homozygous normal, or homozygous affected (not yet symptomatic) with a probability of at least 90%, while 77% could be classified with a probability of at least 80%. Our results demonstrate that even though there is a significant decrease on average in serum copper concentration in Wilson's disease heterozygotes compared to normal homozygotes, other sources of variation in serum copper concentration are much greater and preclude use of serum copper to detect heterozygotes for Wilson's disease. Subsequent analyses showed that a familial component, independent of WND genotype, is the major factor accounting for variation in ceruloplasmin levels among unaffected individuals; age is another factor accounting for more variation in copper levels among unaffected individuals than WND genotype.     

A novel approach for evaluating tyrosine kinase activity based on the radioimmunological determination of phosphotyrosine.

A novel technique was designed to conveniently determine substrate phosphorylation by tyrosine kinase. The technique is based on quantitation of phosphotyrosine content of the phosphoproteins, generated during the enzyme reaction, by radioimmunoassay. Here, we utilized high-titer monoclonal antibodies to phosphotyrosine, and radioiodinated bovine serum albumin-phosphotyrosine conjugate. The radiolabeled antigen was displaced from the complex formed in the assay by unlabeled phosphotyrosine, phosphotyrosine derivatives or phosphotyrosine-containing protein substrates. Half-maximal displacement was achieved at 0.4 +/- 0.05 microM by free phosphotyrosine, and at 40 +/- 3 and 45 +/- 4 nM by acetyl-phosphotyrosine and acetyl-phosphotyrosyl-glycine ethyl ester, respectively. Neither phosphoserine, phosphothreonine nor ATP cross-reacted with the phosphotyrosine antibodies. None of the components of the enzyme reaction interfered in the RIA. The method allows quantitation of the incorporated phosphate into tyrosyl residues without interference of serine/threonine phosphorylation. This technique avoids the use of short-lived [gamma-32P]ATP and omits the separation of the phosphorylated substrate from excess nucleotide.     

Thigmomorphogenesis: The induction of callose formation and ethylene evolution by mechanical perturbation in bean stems

Mechanical perturbation by rubbing of the first internode of 11–12 day old plants of Phaseolus vulgaris L. cv. Cherokee wax induces the rapid deposition of callose in the cells of phloem and other tissues. Callose deposition begins immediately after mechanical perturbation, and shows a minor transient peak 1.5 h, and a major peak 6 h later. The callose gradually disappears and is gone after 3 days. If the stems are perturbed every day, the amount of callose decreases by day 2 but then gradually increases again through day 12. Both the top and bottom of the internode produce callose in response to mechanical perturbation. The evolution of ethylene in response to mechanical perturbation begins after 1 h, peaks at 2–3 h and is gone by 5–6 h. A spray of 10⁻² M 2-deoxy-D-glucose (DDG) completely blocks stem thickening, callose deposition and ethylene evolution due to mechanical perturbation. DDG at 10⁻⁵ to 10⁻⁴ M blocks callose production in mechanically perturbed stem segments and increases ethylene evolution from unperturbed stem segments to greater levels than those obtained by mechanically perturbed segments. It is concluded that mechanical perturbation of bean stems tissue induces deposition of callose more rapidly than it induces evolution of ethylene and that DDG can block both processes.