Lipid chain length effect on the phase behaviour of PCs/PEG:2000-PEs mixtures. A spin label electron spin resonance and spectrophotometric study

Spin-label electron spin resonance (ESR) spectroscopy and spectrophotometry at fixed wavelength are used to study fully hydrated aqueous dispersions of phosphatidylcholines (PCs) with poly(ethylene glycol:2000)-phosphatidylethanolamines (PEG:2000-PEs). PEG:2000-PE is a micelle-forming polymer-lipid that is extensively used for increasing the lifetime of PC liposomes in the blood circulation through a steric stabilisation effect. The PC lipids and the PEG:2000-PE polymer-lipids have the same acyl chain length of either dimiristoyl (DM) or distearoyl (DS) chains. DMPC/PEG:2000-DMPE and DSPC/PEG:2000-DSPE mixtures were investigated over the entire range of relative compositions (0-100 mol%). In both dispersions, the low-temperature conventional spin label ESR spectra and the temperature dependence of the absorbance at 400 nm give an indication of the conversion from lamellae to micelles with increasing PEG:2000-PEs content. The physical state of the lipid assemblies, lamellar or micellar, is dependent not only on PEG:2000-PEs content, but also on the length of hydrocarbon chain of the lipid matrix. Micellisation is attained more readily in dispersions with longer hydrocarbon chains (i.e. in DSPC/PEG:2000-DSPE mixtures) than in those with shorter acyl chains (i.e. in DMPC/PEG:2000-DMPE mixtures). Saturation transfer ESR (ST-ESR) and absorbance measurements reflect the disaggregation of the bilayers and a reduction in the size of the lipid aggregates by PEG:2000-PEs at low content.     

Cloning, structure, expression analysis, and assignment to mouse Chromosome 7 of the gene Zfp296 encoding a zinc finger protein

Received: 4 May 2000 / Accepted: 16 June 2000     

LipofectAMINE2000与Fugene6转染细胞的效率比较

目的:比较LipofectAMINE2000与Fugene6转染细胞的效果。方法:将含有Firefly和Renilla荧光素酶基因的质粒分别用LipofectAMINE2000和Fugene6转染293T、HepG2和DLD-1细胞,于48h后裂解细胞测定荧光素酶活性。结果:在293T细胞中,LipofectAMINE2000转染组的萤火虫(Firefly)和Renilla荧光素酶活性分别是Fugene6转染组的6.5和5.6倍(P<0.005);在HepG2细胞中,LipofectAMINE2000转染组的Firefly和Renilla荧光素酶活性分别是Fugene6转染组的44和49倍(P<0.001);而在DLD-1细胞中,两者无差别。结论:转染试剂LipofectAMINE2000和Fugene6对不同细胞的转染效果存在差异,当进行转染实验时,对于不同的细胞须根据情况进行选择。     

Historical Archaeologies of Global Capitalism and Colonization

The Historical Archaeology of Buenos Aires:. City at the End of the World. Daniel Schavelzon. New York: Kluwer Academic/Plenum Publishers, 2000. 187 pp.
Domestic Architecture and Power: The Historical Archaeology of Colonial Ecuador. Ross W. Jamieson. New York: Kluwer Academic/Plenum Publishers, 2000. 244 pp.
Historical Archaeology in Wachovia: Excavating Eighteenth- Century Bethabara and Moravian Pottery. Stanley South. New York: Kluwer Academic/Plenum Publishers, 1999. 442 pp.
Historical Archaeology of the Ottoman Empire: Breaking New Ground. Uzi Baram and Lynda Carroll. eds. New York: Kluwer Academic/Plenum Publishers, 2000. 272 pp.     

Combined Review: Experiencing the New Genetics: Family and Kinship on the Medical Frontier and Born and Bred: Idioms and New Reproductive Technologies in England

Experiencing the New Genetics: Family and Kinship on the Medical Frontier. Kaja Finkler. Philadelphia: University of Pennsylvania Press, 2000. 296 pp.
Born and Bred: Idioms and New Reproductive Technologies in England. Jeanette Edwards. New York: Oxford University Press, 2000. 264 pp.     

Other Perspectives on the Kennewick Man Controversy

Skull Wars: Kennewick Man, Archaeology, and the Battle for Identity. David Hurst Thomas. New York: Basic Books, 2000. 326 pp.
Riddle of the Bones: Politics, Science, Race, and the Story of Kennewick Man. Roger Downey. New York: Copernicus, 2000. 202 pp.     

A survey on non specialized off-the-shelf JPEG2000 viewers for digital microscopy use

The present paper will present a survey on features of a number of non-specialized off-the-shelf JPEG2000 viewers, seen from the point of view of digital microscopy. Selected viewers were tested within a number of usage scenarios, including: i) open a conformance test JPEG2000 file; ii) open a large JPEG2000 file; iii) moving from one point to another; iv) changing resolution/magnification. For each scenario, data recorded included: successful or unsuccessful operation; time needed for conclusion; occasional problems.Preliminary results demonstrate that JPEG2000 conformance as stated by many viewers is only limited to some of the possibilities of the JPEG2000 standard, in particular for what regards file size.     

Medicalized Mothering: Perspectives from the Lives of African-American and Jewish Women; Measuring Mama's Milk: Fascism and the Medicalization of Maternity in Italy

Medicalized Mothering: Perspectives from the Lives of African-American and Jewish Women. Jacquelyn S. Litt. New Brunswick, NJ: Rutgers University Press, 2000. xi+ 189 pp.
Measuring Mama's Milk: Fascism and the Medicalization of Maternity in Italy. Elizabeth Dixon Whitaker. Ann Arbor: University of Michigan Press, 2000. vii. 358 pp.     

Spatial Organization of Microbial Biofilm Communities

Abstract The application of advanced microscopy and molecular and electrochemical high-resolution methods has provided insights into the structural organization and function of biofilm communities. It appears that cellular properties such as growth differentiation, chemotaxis, and cell-to-cell signaling enable biofilm communities to organize structurally in response to the external conditions and the activities of the different biofilm members. Thereby resource utilization becomes optimized, and processes which require syntrophic relationships or special micro-environments become facilitated. Received: 23 February 2000; Accepted: 8 June 2000; Online Publication: 28 August 2000     

A mouse phenome project

A community-wide effort to establish baseline phenotypic data on commonly used and genetically diverse inbred mouse strains and to provide the information through a publicly accessible database. Received: 21 April 2000 / Accepted: 25 April 2000     

Anaerobic sequencing batch reactors for wastewater treatment: a developing technology

This paper describes and discusses the main problems related to anaerobic batch and fed-batch processes for wastewater treatment. A critical analysis of the literature evaluated the industrial application viability and proposed alternatives to improve operation and control of this system. Two approaches were presented in order to make this anaerobic discontinuous process feasible for industrial application: (1) optimization of the operating procedures in reactors containing self-immobilized sludge as granules, and (2) design of bioreactors with inert support media for biomass immobilization. Received: 22 May 2000 / Received revision: 20 July 2000 / Accepted: 21 July 2000     

The Elusive Embryo: How Men and Women Approach New Reproductive Technologies; Ideologies and Technologies of Motherhood: Race, Class, Sexuality, Nationalism

The Elusive Embryo: How Men and Women Approach New Reproductive Technologies. Gay Becker. Berkeley: University of California Press, 2000.x. 320 pp.
Ideologies and Technologies of Motherhood: Race, Class, Sexuality, Nationalism. Heléna Ragoné and France Winddance Twine. eds. New York: Routledge, 2000. xvii. 330 pp.     

Drawing on Cultural Memory: Self and Other in Native American Ledger Art

Spirit Beings and Sun Dancers: Black Hawk's Vision of the Lakota World. Janet Catherine Berlo. New York: George Braziller, Inc., 2000. 189 pp.
Arrow's Elk Society Ledger. Mike Cowdrey. Santa Fe: Morning Star Gallery, 1999. 254 pp.
Will Tell of My War Story. Scott M. Thompson. Seattle: University of Washington Press, 2000. 120 pp.     

Hair in African Art and Culture

Hair in African Art and Culture. The Museum for African Art, New York, February 9–May 28, 2000 (review venue); Apex Museum, Atlanta, July–September 2000; Cantor Center for Visual Arts, Stanford University, Palo Alto, California, October–December 2000; Museum of African American History, Detroit, January–April 2001; California African American Museum, Los Angeles, May–August 2001.
Hair in African Art and Culture. Roy Sieber and Frank Herreman. eds. New York: The Museum for African Art; Munich, London, New York: Prestel, 2000. 192 pp.     

Comparison of normal distribution–based and nonparametric decision limits on the GH‐2000 score for detecting growth hormone misuse (doping) in sport

This paper is motivated by the GH‐2000 biomarker test, though the discussion is applicable to other diagnostic tests. The GH‐2000 biomarker test has been developed as a powerful technique to detect growth hormone misuse by athletes, based on the GH‐2000 score. Decision limits on the GH‐2000 score have been developed and incorporated into the guidelines of the World Anti‐Doping Agency (WADA). These decision limits are constructed, however, under the assumption that the GH‐2000 score follows a normal distribution. As it is difficult to affirm the normality of a distribution based on a finite sample, nonparametric decision limits, readily available in the statistical literature, are viable alternatives. In this paper, we compare the normal distribution–based and nonparametric decision limits. We show that the decision limit based on the normal distribution may deviate significantly from the nominal confidence level or nominal FPR when the distribution of the GH‐2000 score departs only slightly from the normal distribution. While a nonparametric decision limit does not assume any specific distribution of the GH‐2000 score and always guarantees the nominal confidence level and FPR, it requires a much larger sample size than the normal distribution–based decision limit. Due to the stringent FPR of the GH‐2000 biomarker test used by WADA, the sample sizes currently available are much too small, and it will take many years of testing to have the minimum sample size required, in order to use the nonparametric decision limits. Large sample theory about the normal distribution–based and nonparametric decision limits is also developed in this paper to help understanding their behaviours when the sample size is large.     

Analysis of dielectric spectra of eukaryotic cells by computer modeling

An analysis of dielectric spectra, obtained by computer modeling, of spherical eukaryotic cells (lymphocytes in particular) is presented. The number of fitting parameters required to describe these spectra is determined. The influence of parameter variation on the spectral shape is illustrated. Received: 27 May 1999 / Revised version: 24 January 2000 / Accepted: 26 January 2000     

The Cambridge History of the Native Peoples of the Americas: Vol. 2: Mesoamerica, Part 1.; The Cambridge History of the Native Peoples of the Americas: Vol. 2: Mesoamerica, Part 2.

The Cambridge History of the Native Peoples of the Americas: Vol. 2: Mesoamerica, Part 1. Richard E. W. Adams and Murdo J. MacLeod. eds. Cambridge: Cambridge University Press, 2000. 571 pp.
The Cambridge History of the Native Peoples of the Americas: Vol. 2: Mesoamerica, Part 2. Richard E. W. Adams and Murdo J. MacLeod. eds. Cambridge: Cambridge University Press, 2000. 455 pp.     

Are there lessons from negative results in studies using video playback?

The use of video playback is a growing practice in animal behaviour. Studies that lead to unpredicted negative results are often considered failures and remain unpublished. In this article I review some of the published and unpublished studies that have led to negative results. Analysis of these studies suggests that no particular problem is responsible for more than a small number of negative results. I suggest further investigation of the potential causes of these negative results to assess their importance to the outcome of video playback experiments. Received: 31 January 2000 / Received in revised form: 27 March 2000 / Accepted: 28 March 2000     

Energetics of Anaerobic Degradation Pathways of Chlorinated Aliphatic Compounds

Abstract This minireview explores the energetics of the (anaerobic) oxidative and fermentative degradation of halogenated ethenes and ethanes. It is shown that these pathways are viable alternatives to the traditional routes that start with one or more reductive dechlorination steps. In contrast to reductive dehalogenation, oxidative and fermentative degradation pathways do not require an external source of reducing equivalents. This suggests that organisms that use these pathways are most likely to be found at high redox potentials, i.e, under conditions where competition for reducing equivalents is great. Received: 10 February 2000; Accepted: 6 April 2000; Online Publication: 13 June 2000     

Knowledge acquisition,consistency checking and concurrency control for Gene Ontology (GO)

MOTIVATION: A critical element of the computational infrastructure required for functional genomics is a shared language for communicating biological data and knowledge. The Gene Ontology (GO; http://www.geneontology.org) provides a taxonomy of concepts and their attributes for annotating gene products. As GO increases in size, its ongoing construction and maintenance becomes more challenging. In this paper, we assess the applicability of a Knowledge Base Management System (KBMS), Protégé-2000, to the maintenance and development of GO. RESULTS: We transferred GO to Protégé-2000 in order to evaluate its suitability for GO. The graphical user interface supported browsing and editing of GO. Tools for consistency checking identified minor inconsistencies in GO and opportunities to reduce redundancy in its representation. The Protégé Axiom Language proved useful for checking ontological consistency. The PROMPT tool allowed us to track changes to GO. Using Protégé-2000, we tested our ability to make changes and extensions to GO to refine the semantics of attributes and classify more concepts. AVAILABILITY: Gene Ontology in Protégé-2000 and the associated code are located at http://smi.stanford.edu/projects/helix/gokbms/. Protégé-2000 is available from http://protege.stanford.edu.