Overconfidence in Interval Estimates.

Judges were asked to make numerical estimates (e.g., "In what year was the first flight of a hot air balloon?"). Judges provided high and low estimates such that they were X% sure that the correct answer lay between them. They exhibited substantial overconfidence: The correct answer fell inside their intervals much less than X% of the time. This contrasts with choices between 2 possible answers to a question, which showed much less overconfidence. The authors show that overconfidence in interval estimates can result from variability in setting interval widths. However, the main cause is that subjective intervals are systematically too narrow given the accuracy of one's information-sometimes only 40% as large as necessary to be well calibrated. The degree of overconfidence varies greatly depending on how intervals are elicited. There are also substantial differences among domains and between male and female judges. The authors discuss the possible psychological mechanisms underlying this pattern of findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Belcoro:Autocoro转杯纺纱的营销和纺纱工艺

与传统的环锭纺相比，Autocoro转杯纺纱劳动生产率高，工艺短，自动化程度高，Schlafhorst公司为此作出了贡献。     

Positive charges determine the topology and functionality of the transmembrane domain in the chloroplastic outer envelope protein Toc34

The ECAT EXACT3D (CTI/Siemens 966) 3D-only PET tomograph has unprecedented sensitivity due to the large BGO (bismuth germanate) detector volume. However, the consequences of a large (23.4 cm) axial field-of-view (FOV) and the need for a patient port diameter to accommodate body scanning make the device more sensitive to photons arising from activity outside the direct (coincidence) FOV. This leads to relatively higher deadtime and an increased registration of random and scatter (true) coincidences. The purpose of this study is to determine the influence of activity outside the FOV on (i) noise-equivalent counts (NEC) and (ii) the performance of a 'model-based' scatter correction algorithm, and to investigate the effect of side shielding additional to that supplied with the tomograph. Annular shielding designed for brain scanning increased the NEC for blood flow (H[2]15O) measurement (integrated over 120 s) by up to 25%. For 11C tracer studies, the increase is less than 5% over 120 min. Purpose-built additional body shielding, made to conform to the shape of a volunteer, reduced the randoms count rate in a heart blood flow measurement (H[2]15O) by about 30%. After scatter correction the discrepancy between ROI count ratios for compartments within the 20 cm diameter 'Utah' phantom differed by less than 5% from true (sampled) activity concentration ratios. This was so with or without activity outside the FOV and with or without additional side shielding. Count rate performance is thus improved by extra shielding but more improvement is seen in head than in body scanning. Measurement of heart blood flow using bolus injections of H(2)15O would benefit from the use of detectors with lower deadtime and superior timing resolution such as LSO (lutetium oxyorthosilicate).     

A computer-assisted system for reconstructing and interpreting the dynamic three-dimensional relationships of the outer surface, nucleus and pseudopods of crawling cells

Newly developed software additions to the three-dimensional dynamic image analysis system, 3D-DIAS, are described for simultaneously reconstructing and motion analyzing in three dimensions the outer surface, nucleus and pseudopods of living, crawling cells. This new system is then used to describe for the first time a nuclear behavior cycle in translocating Dictyostelium discoideum amoebae and to investigate the role of pseudopod extension in this process. The nuclear behavior cycle is tuned to the two phases of the general cell behavior cycle [Wessels et al., 1994], and includes nuclear migration both in the z- and in the x,y-axes from the proximal border of the prior anterior pseudopod to the proximal border of a newly expanding anterior pseudopod. Nuclear migration is cued by pseudopod-substratum contact, achieves velocities in excess of 50 microm/min, and is accompanied by characteristic changes in nuclear shape. The rules and characteristics of nuclear behavior are demonstrated to be intact in two mutants affecting pseudopod formation, a myosin IB null mutant (myoB-) and a myosin II heavy chain phosphorylation mutant (3XALA). The rules and characteristics of nuclear migration, however, are disrupted upon dissolution of microtubules by colcemid. Together the above results demonstrate that the newly developed 3D-DIAS system can be used to gain new insights into the dynamic changes in the intracellular 3D architecture associated with cellular translocation.     

Candida albicans endocarditis associated with a contaminated aortic valve allograft: implications for regulation of allograft processing

A patient developed Candida albicans endocarditis and fungemia after undergoing aortic valve replacement with an allograft. The allograft had been found during tissue bank processing to be contaminated with C. albicans, but it was culture-negative for C. albicans after routine disinfection with an antifungal-containing antimicrobial solution. Comparison of the preimplantation and postimplantation C. albicans isolates revealed remarkable genetic similarity, but antifungal susceptibility testing showed that the postimplantation isolate was more resistant to fluconazole and amphotericin B than the preimplantation isolate, suggesting emergence of resistance after disinfection. Implantation of a contaminated heart valve allograft can occur despite disinfection during processing and can result in endocarditis in the recipient. Antimicrobial disinfection protocols that include antifungal drugs may be ineffective. Current U.S. Food and Drug Administration regulations do not require companies to specify details concerning allograft processing. Additional measures may be required to prevent tissue bank release of allografts contaminated with C. albicans or other pathogens.     

Spinach chloroplast cpn21 co-chaperonin possesses two functional domains fused together in a toroidal structure and exhibits nucleotide-dependent binding to plastid chaperonin 60

Chloroplasts contain a 21-kDa co-chaperonin polypeptide (cpn21) formed by two GroES-like domains fused together in tandem. Expression of a double-domain spinach cpn21 in Escherichia coli groES mutant strains supports growth of bacteriophages lambda and T5, and will also suppress a temperature-sensitive growth phenotype of a groES619 strain. Each domain of cpn21 expressed separately can function independently to support bacteriophage lambda growth, and the N-terminal domain will additionally suppress the temperature-sensitive growth phenotype. These results indicate that chloroplast cpn21 has two functional domains, either of which can interact with GroEL in vivo to facilitate bacteriophage morphogenesis. Purified spinach cpn21 has a ring-like toroidal structure and forms a stable complex with E. coli GroEL in the presence of ADP and is functionally interchangeable with bacterial GroES in the chaperonin-facilitated refolding of denatured ribulose-1,5-bisphosphate carboxylase. Cpn21 also inhibits the ATPase activity of GroEL. Cpn21 binds with similar efficiency to both the alpha and beta subunits of spinach cpn60 in the presence of adenine nucleotides, with ATP being more effective than ADP. The tandemly fused domains of cpn21 evolved early and are present in a wide range of photosynthetic eukaryotes examined, indicating a high degree of conservation of this structure in chloroplasts.     

Strategies for revising judgment: How (and how well) people use others’ opinions.

A basic issue in social influence is how best to change one’s judgment in response to learning the opinions of others. This article examines the strategies that people use to revise their quantitative estimates on the basis of the estimates of another person. The authors note that people tend to use 2 basic strategies when revising estimates: choosing between the 2 estimates and averaging them. The authors developed the probability, accuracy, redundancy (PAR) model to examine the relative effectiveness of these two strategies across judgment environments. A surprising result was that averaging was the more effective strategy across a wide range of commonly encountered environments. The authors observed that despite this finding, people tend to favor the choosing strategy. Most participants in these studies would have achieved greater accuracy had they always averaged. The identification of intuitive strategies, along with a formal analysis of when they are accurate, provides a basis for examining how effectively people use the judgments of others. Although a portfolio of strategies that includes averaging and choosing can be highly effective, the authors argue that people are not generally well adapted to the environment in terms of strategy selection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Origin of a chloroplast protein importer

During evolution, chloroplasts have relinquished the majority of their genes to the nucleus. The products of transferred genes are imported into the organelle with the help of an import machinery that is distributed across the inner and outer plastid membranes. The evolutionary origin of this machinery is puzzling because, in the putative predecessors, the cyanobacteria, the outer two membranes, the plasma membrane, and the lipopolysaccharide layer lack a functionally similar protein import system. A 75-kDa protein-conducting channel in the outer envelope of pea chloroplasts, Toc75, shares approximately 22% amino acid identity to a similarly sized protein, designated SynToc75, encoded in the Synechocystis PCC6803 genome. Here we show that SynToc75 is located in the outer membrane (lipopolysaccharide layer) of Synechocystis PCC6803 and that SynToc75 forms a voltage-gated, high conductance channel with a high affinity for polyamines and peptides in reconstituted liposomes. These findings suggest that a component of the chloroplast protein import system, Toc75, was recruited from a preexisting channel-forming protein of the cyanobacterial outer membrane. Furthermore, the presence of a protein in the chloroplastic outer envelope homologous to a cyanobacterial protein provides support for the prokaryotic nature of this chloroplastic membrane.     

Protein translocation into and across the chloroplastic envelope membranes

A revolution has occurred in the attitude of biologists toward their intellectual property rights. What today is patentable and highly profitable was, 20 years ago, unpatentable and given away for nothing. The history of this revolution began in the early 1960s when we made the first effort to have self-duplicating cell strains patented. The application was denied because patent law at that time did not include living matter. Because of the demand for our normal human diploid cell strain, WI-38, by NIH grantees, NIH support was provided to distribute WI-38 gratis to hundreds of recipients. These included vaccine and cell manufacturers who profited enormously from the direct sale of WI-38 or its use as a substrate for many human virus vaccines. When federal support for the distribution of WI-38 ended, but demand did not, I continued to distribute it for costs similar to those made by the American Type Culture Collection. When I took the first initiative and asked NIH to have the then unique question of title to a self-duplicating system resolved, they sent an accountant who accused me of theft of government property. I replied with a lawsuit that, after six years of litigation, we won with an out-of-court settlement. During these six years the United States Supreme Court ruled that living matter could be patented. Also, the biotechnology industry was launched by biologists who, like me, started companies using cells or microorganisms developed with federal support. This use of intellectual property rights by the nascent biotechnology industry was ultimately embraced by the entire biological community and by a directive from the President of the United States. This revolution has now evolved to the point where government biologists themselves may profit from research in federal laboratories, and the NIH itself aggressively seeks private commercial alliances. Universities have also pursued similar alliances to the extent that today the distinction between a research university and a commercial organization is only in the eyes of the Internal Revenue Service.     

Poly(ionic liquid) nanoparticles as novel colloidal template for silica nanocasting

Spherical poly(ionic liquid) (PIL) nanoparticles of different size (25–70 nm) were synthesized and applied as a novel colloidal soft template for the preparation of meso- and macroporous inorganics, here exemplified with silica and its metal nanoparticle doping via nanocasting. Pore size and pore architecture can be adjusted by appropriate choice of the template and the reaction conditions. Unexpectedly, it was found that the in situ generated methanol plays a very important role during the casting process. It enlarged the overall surface area by introducing a significant fraction of micropores and small mesopores. The largest specific surface area was obtained at an optimized ratio of tetramethyl orthosilicate (TMOS) to PIL nanoparticle. In addition, PIL nanoparticles pre-functionalized with Pt metal nanoparticles were used in the same manner as hybrid templates for nanocasting. The pyrolysis conditions were optimized to synthesize mesoporous silica functionalized with uniformly distributed metal nanoparticles of very small size in a one-pot process.