Phosphopantetheinylation and Specificity of Acyl Carrier Proteins in the Mupirocin Biosynthetic Cluster

Acyl carrier proteins are vital for the biosynthesis of fatty acids and polyketides. The mupirocin biosynthetic cluster of Pseudomonas fluorescens encodes eleven type I ACPs embedded in its multifunctional polyketide synthase (PKS) proteins plus five predicted type II ACPs (mAcpA‐E) that are known to be essential for mupirocin biosynthesis by deletion and complementation analysis. MupN is a putative Sfp‐type phosphopantetheinyl transferase. Overexpression of three type I and three type II mupirocin ACPs in Escherichia coli, with or without mupN, followed by mass spectroscopy revealed that MupN can modify both mupirocin type I and type II ACPs to their holo‐form. The endogenous phosphopantetheinyl transferase of E. coli modified mAcpA but not mAcpC or D. Overexpression of the type II ACPs in macp deletion mutants of the mupirocin producer P. fluorescens 10586 showed that they cannot substitute for each other while hybrids between mAcpA and mAcpB indicated that, at least for mAcpB, the C‐terminal domain determines functional specificity. Amino acid alignments identified mACPs A and D as having C‐terminal extensions. Mutation of these regions generated defective ACPs, the activity of which could be restored by overexpression of the macp genes on separate plasmids.     

Insulation workers in Belfast. A further study of mortality due to asbestos exposure (1940-75)

A follow-up study of 162 men already working as insulators (laggers) in 1940 has been extended from 1965 to 1975. By the end of 1975 there were 40 survivors when 108 had been expected. Until 1965 there had been an overall excess of deaths; these were due to asbestosis with or without tuberculosis and to alimentary cancer, as well as to bronchial carcinoma and mesothelioma. From 1965 onwards the overall death rate among survivors is not so excessive but there is still a marked excess of deaths from bronchial cancer and mesothelioma. The continued risk of death attributable to malignancy after asbestosis had ceased to contribute directly, does not appear to be caused by any changes which occurred before 1940 in the conditions at work.     

Morphologic alteration of Paranaplasma caudata following treatment of calves with oxytetracycline

The morphologic features of Paranaplasma caudata were determined in whole blood, blood clots, and liver biopsy specimens after treating infected calves with oxytetracycline. Following staining of blood smears with new methylene blue, light microscopy showed that paranaplasma bodies in erythrocytes of treated calves were vacuolated, but tails were normal in appearance. By electron microscopic examination of parasitized erythrocytes of treated calves, paranaplasma bodies were found to be degenerated (aggregation of nucleoprotein granules in initial bodies and condensation and coalescence of initial bodies), but tails were normal. The identical degenerative changes of paranaplasma bodies and lack of alteration of tails were evident in erythrocytes in sinusoids of liver biopsy specimens from treated calves.     

Evidence of two β’ phases in tristearin

Data from Raman spectroscopy, X-ray diffraction analysis, differential scanning calorimetry and features of the preparative method are all consistent with the existence of 2 intermediate β’ phases for tristearin; the first, a lower melting phase, β’₂, transforms at 61 C into the second, β’₁ , which in turn changes at 64 C into β-tristearin. Raman spectral evidence indicates that the 2 mesophases occur in an orthorhombic packing environment and that the β’₂ to β’₁ transition results from a change in lateral packing of the hydrocarbon chains.     

纺织品测色前试样调湿的重要性及其注意问题

测色前将纺织试样调节到标准温、湿度很重要。了解影响温度和湿度的参数可确保试样得到恰当的调湿。为了达到真正所需的条件,在设计一个试验间时必须把导致条件偏差的各个方面考虑在内。文章从单点稳定性、均匀性、传感器精确度、调湿时间等方面做了讨论。     

The application of quantum well solar cells to thermophotovoltaics

We discuss the advantages of quantum well solar cells (QWSCs) for thermophotovoltaic (TPV) applications and illustrate them with InP/InGaAs and GaInAsP/InGaAs QWSCs which were designed for other applications and have not been optimised for TPV. It is shown that an InP p-i-n solar cell with 15 lattice matched InGaAs quantum wells (QWs) in the i region has an increase in open circuit voltage (V_oc) of (1.7 ± 0.1) times that of a control cell of InP with InGaAs in the i-region under an illuminating spectrum close to that expected from an ideal ytterbia emitter. Also, using an InGaAsP quaternary cell of band gap wavelength of 1.1 Am with 60 InGaAs QWs under the same illuminating spectrum the current density is increased by a factor of (2.4 ± 0.1) over that of the InP QWSC. The quaternary cell also absorbs longer wavelengths without any significant loss in V_OC. Better temperature coefficients for the former quantum well solar cell than the control cell are observed in a spectrum approximating a black body at 3000 K. Further advantages of QWs for narrow band and broad band illuminating spectra are discussed.     

Depression and the assessment of Type A behavior in a clinical population.

The Structured Interview (SI) method of assessing Type A behavior pattern (TABP) relies on the S's voice stylistics, whereas the Jenkins Activity Survey (JAS) relies on response content. It was hypothesized that depression would affect SI assessments by masking voice stylistics but would have no impact on JAS assessments. The SI, JAS, and the Zung Self-Rating Depression Scale were administered to 2,066 coronary patients. As predicted, there was a negative relationship between depression and SI-assessed TABP and a modest positive relationship between depression and JAS-assessed TABP. Analysis of Type A components revealed that loudness, explosive speech, and intensity of hostility differed between depressed and nondepressed patients. Affective states that influence expressivity appear to produce misclassifications using SI assessments, especially in clinical samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An exergy-based framework for evaluating environmental impact

The analysis framework introduced in this paper utilizes the recognition that exergy is a form of environmental free energy to provide a fundamental basis for valuing environmental interactions independent from their secondary impacts (e.g., global warming, photochemical smog). In order to extend exergy to analyze environmental interactions, modifications are required to the traditional representation of the environment and definition of the dead state used in technical exergy analysis. These are accomplished through a combination of logical extensions and use of non-equilibrium thermodynamic principles. The framework is comprised of two separate components: (1) environmental exergy analysis and (2) anthropocentric sensitivity analysis. Environmental exergy analysis is based on fundamental thermodynamic principles and analysis techniques. It extends the principles of technical exergy analysis to the environment in order to quantify the locations, magnitudes, and types of environmental impact—state change, alteration of natural transfers, and destruction change. Anthropocentric sensitivity analysis is based on the concepts of anthropocentric value and anthropocentric sensitivity. It enables the results of environmental exergy analysis to be interpreted for decision making, but at the expense of introducing some subjectivity into the framework. A key attribute of the framework is its ability to evaluate and compare the environmental performance of energy systems on a level playing field, regardless of the specifics of the systems—resources, by-products, sizes, time scales.