bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiple oligomeric forms of Escherichia coli DnaB helicase revealed by electrospray ionisation mass spectrometry
Authors: Watt Stephen J. , Urathamakul Thitima , Schaeffer Patrick M. , Williams Neal K. , Sheil Margaret M. , Dixon Nicholas E. , Beck Jennifer L. 
Published: December 2006

AbstractThe Escherichia coli DnaB protein (DnaB6) is the hexameric helicase that unwinds genomic DNA so it can be copied by the DNA replication machinery. Loading of the helicase onto DNA requires interactions of DnaB6 with six molecules of its loading partner protein, DnaC. Nano‐electrospray ionisation mass spectrometry (nanoESI‐MS) of mutant proteins was used to examine the roles of the residues Phe102 (F102) and Asp82 (D82) in the N‐terminal domain of DnaB in the assembly of the hexamer. When the proteins were prepared in 1 M ammonium acetate containing magnesium and adenosine triphosphate (ATP) at pH 7.6, both hexameric and heptameric forms of wild‐type and F102W, F102E and D82N mutant DnaBs were observed in mass spectra. The spectra of the D82N mutant also showed substantial amounts of a decameric species and small amounts of a dodecamer. In contrast, the F102H DnaB mutant was incapable of forming oligomers of order higher than the hexamer. Thus, although Phe102 is not the only determinant of hexamer assembly, this residue has a role in oligomerisation. NanoESI mass spectra were obtained of mixtures of DnaB6 with DnaC. The DnaB6(DnaC)6 complex (calculated Mr 481 164) was observed only when the two proteins were present in equimolar amounts. The data are consistent with cooperative assembly of the complex. ESI mass spectra of mixtures containing DnaC and ATP showed that DnaC slowly hydrolysed ATP to ADP as indicated by ions corresponding to DnaC/ATP and DnaC/ADP complexes. These experiments show that E. coli DnaB can form a heptameric complex and that nanoESI‐MS can be used to probe assembly of large (>0.5 MDa) macromolecular complexes. Copyright © 2006 John Wiley & Sons, Ltd.
Characterization of oxysterols by electrospray ionization tandem mass spectrometry after one‐step derivatization with dimethylglycine
Authors: Jiang Xuntian , Ory Daniel S. , Han Xianlin 
Published: December 2006

AbstractWe report a novel approach to derivatize the primary, secondary, and tertiary hydroxy group(s) of oxysterols with N,N‐dimethylglycine (DMG) in the presence of both 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide and 4‐(N,N‐dimethylamino)pyridine to yield their corresponding mono‐ or di‐DMG esters. Eight oxysterols including 7‐oxocholesterol, 5α,6α‐ and 5β,6β‐epoxycholesterols, as well as 7α‐, 7β‐, 24(S)‐, 25‐, and 27‐hydroxycholesterols, were studied. Electrospray ionization tandem mass spectrometric characterization of these singly or doubly protonated derivatives demonstrates the presence of an informative fragmentation pattern for each oxysterol derivative. Potential dissociation pathways for the production of these unique fragmentation patterns are proposed and discussed. Collectively, these informative and unique fragmentation patterns allow rapid and direct discrimination of the identities of 7α‐, 7β‐, 24(S)‐, 25‐, and 27‐hydroxycholesterol isomers, as well as 5α,6α‐ and 5β,6β‐epoxycholesterol isomers, thereby potentially providing a foundation for quantitative analysis of oxysterols in biological samples in combination with a chromatographic separation. Copyright © 2006 John Wiley & Sons, Ltd.
Mass spectrometric evidence for different complexes of peptides and proteins with arsenic(III), arsenic(V), copper(II), and zinc(II) species
Authors: Schmidt Anne‐Christine , Koppelt Jenny , Neustadt Madlen , Otto Matthias 
Published: December 2006

AbstractTrivalent and pentavalent arsenic were incubated with sulfur‐containing amino acid, peptide and protein solutions both as organic compounds (phenylarsine oxide, phenylarsonic acid, dimethylarsinic acid, monomethylarsonic acid) and as inorganic compounds (arsenite, As(III), and arsenate, As(V)). After incubation of phenylarsine oxide solutions with cysteine and glutathione the mass spectra showed a covalent bond between arsenic and sulfur, which was stable at both acidic and neutral pH values. The mass spectra were dominated by monovalent ions at m/z 272 for cysteine samples and at m/z 458 for glutathione samples. Based on these masses the ionic structures could be ascribed to either fragment ions of the covalent arsenic‐sulfur complexes or to other arsenic‐bonding sites presumably at the amino group. Interestingly, under the same conditions no interactions of inorganic arsenite or arsenate could be measured. In the presence of added Cu2+ ions all mass signals caused by a reaction of phenylarsine oxide with glutathione disappeared. In these mass spectra only the oxidised form of glutathione (GSSG) was found because of the redox activity of Cu(II). For the model protein lysozyme, no interactions with arsenic could be detected, whereas definite Cu‐ and Zn‐lysozyme complexes with a stoichiometry of 1:1 and 2:1 for Zn2+ ions and Cu2+ ions, respectively, were observed. In contrast, for thioredoxin a bonding of As that depended on the concentration of the disulfide‐reducing agent tris(2‐carboxyethyl) phosphine was demonstrated.For three different phenylarsonic acids and for dimethylarsinic acid that all contain pentavalent arsenic, complexes with glutathione appeared in the mass spectra, which can be attributed to non‐covalent interactions or to a covalent bond caused by an additive reaction.The optimisation of the experimental conditions necessary for the mass spectrometric analysis of the interactions of the arsenic species with peptides and proteins is described and the obtained mass spectra that provide information on the kinds of bonds are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
A faster plant stem‐water extraction method
Authors: Vendramini Patricia F. , Sternberg Leonel da S. L. 
Published: December 2006

AbstractOxygen and hydrogen isotope ratios of stem water have been used by several studies which relate the ecophysiology of plants to their water source. Undoubtedly, there are several other applications and research areas which could use this type of analysis. However, the most often used methods of extracting stem water are slow, limiting the rate of sampling and consequently preventing a deeper understanding of spatial and temporal plant water source use. We have developed a faster batch method of stem‐water extraction and compare it with the most commonly used online method of stem‐water extraction. Samples are sealed in 18 cm long ampoules having their extremities placed sample end in a heating block and the condensing end in a cooling block, and allowed to distill overnight. Up to 72 samples can be distilled overnight and sealed the next morning. The isotope ratios of water distilled by the batch method introduced here compared with those from the online method were in excellent agreement. In addition to being faster, this method does not need the monitoring of hot water baths and liquid nitrogen traps during distillation and does not require a complex vacuum system. Copyright © 2006 John Wiley & Sons, Ltd.
Stress and family relationship functioning as indicators of the severity of fibromyalgia symptoms: a regression analysis
Authors: Murray Thomas L. , Murray Christine E. , Daniels M. Harry 
Published: December 2006

AbstractThis article presents the results of a secondary analysis of data collected from a cross‐sectional survey of 201 individuals with fibromyalgia syndrome (FMS). This study examines the influence of stress and family relationship functioning (differentiation of self) on symptoms severity among FMS patients. The primary analysis of the data (published elsewhere) revealed that perceived levels of stress were correlated with symptom severity, and that other variables related to family functioning moderated this relationship to a small degree. In the secondary analysis presented here, additional relationships among perceived stress, stressful life events, family relationship functioning, age of FMS onset, and symptom severity were examined. The results indicated that participants' levels of symptom severity could be predicted by their level of differentiation and appraisal of stressful life events occurring within a year prior to the age of onset. Consistent with the findings of the primary analyses, the level of perceived stress was the predictor variable that accounted for the greatest amount of variance associated with FMS symptoms. Limitations of the study and recommendations for future research are presented. Copyright © 2006 John Wiley & Sons, Ltd.
The wonder of trivial machines
Authors: Gage Stephen A. 
Published: December 2006

AbstractArchitecture is differentiated from building in that it is deemed to induce sensations of delight or wonder in its observers. The paper takes the metaphor of a trivial machine and argues that a work of architecture is the physical embodiment this. The process of constructing such a machine for the first time is not trivial and can induce sensations of delight in an observer. This applies both to the observer who designs the machine (the architect) and to the observer who passes by and who reconstructs it in his or her understanding. Can trivial machines be constructed which have some of the attributes of non‐trivial machines in that the output is continually surprising and new? When a trivial machine is nested inside another machine whose function is not fully known the result is an inverted, non‐trivial machine in Von Foerster's terms. The paper argues that physical architecture can be observed in this way. Copyright © 2006 John Wiley & Sons, Ltd.
Standing ovation: an attempt to simulate human personalities
Authors: Szilagyi Miklos N. , Jallo Matthew D. 
Published: December 2006

AbstractComputer simulation of human personalities is presented using standing ovation as an example of human social behaviour. Five personality components are used to influence behaviour. The experiment has proven the efficacy of basing a nonlinear dynamic system simulation on precepts derived from personality traits. Copyright © 2006 John Wiley & Sons, Ltd.
Narratives and transdisciplines for a post‐industrial world
Authors: Allen T. F. H. , Giampietro Mario 
Published: December 2006

AbstractAs society moves to a post‐industrial posture, technology rescales human activities into new contexts. A changed context makes meaning different. In that new setting, complexity appears because problems arise scaled outside prevailing disciplines. Without the conventions of established disciplines definitions are lost, and that causes complexity to arise in the equivocation that follows. Rosen suggests that complexity cannot be modelled, precisely because of uncertainty and contradiction, which can be defined away, but only at the loss of complexity. Paradigms work to facilitate modelling with narratives told to make complexity simple enough to model. Complexity disappears into mere complicatedness upon deciding what is significant as opposed to incidental, structural as opposed to dynamical, discontinuous versus continuous and rate‐independent rather than rate‐dependent. With those decisions in hand, one can create and test models to improve the meaning of narratives. Meaning is found in the plan embodied in the Aristotelian formal cause (e.g. DNA) and in the significance of whole structure in the final cause. Aristotle's material cause, the existence of the substance of the whole, is constructed by the interaction of the plan of the formal cause with the Aristotelian efficient cause of the driving gradient (e.g. food, energy). The narrative of the biological or social system moves forward each time an updated material cause forces change on the meaning of the final cause. Narratives can address complexity because they are not about objective reality, but are statements of what is significant. Narratives facilitate commensurate experience as humans construct a post‐industrial society, invoking post‐normal science and post‐modern postures. Transdisciplines face complexity until they self‐consciously develop a new story of their own. The complexity arising from technological rescaling and redefinition of our world can be addressed with sophisticated use of narrative, a central device in systems science. This paper presents a protocol for employing narrative with precision. Copyright © 2006 John Wiley & Sons, Ltd.
Construction of knowledge in the mass media. Systemic problems in the post‐modern power‐struggle between the symbolic generalized media in the Agora: the Lomborg case of environmental science and politics
Authors: Brier Søren 
Published: December 2006

AbstractThe present article analyses the Lomborg case of environmental conflicts in the Agora of the mass media by viewing science, politics, economics, religion and the big news media as differentiated systems using what Luhmann calls symbolic generalized media. Each has its own simplified code and interest that make it easier and faster to canalize messages. But the problem for the public good then becomes that they cannot communicate directly with each other. Each system is closed around its own code and specialists. There are no rules of engagement for the benefit of the greater system of society. Is that a good thing or could the public knowledge generation processes be improved? This article analyses the Lomborg case viewed as a problem of public knowledge management in democratic societies with free presses. Copyright © 2006 John Wiley & Sons, Ltd.
Transdisciplinary unified theory
Authors: François Charles 
Published: December 2006

AbstractNumerous complex issues of the most varied kinds are emerging in our ever more interconnected man–planet settings. Such situations cannot be anymore managed by the piecemeal and uncoordinated interventions that result from growing chasms between multiple specialized disciplines. Accordingly, interdisciplinarity and multidisciplinarity should be framed or, in cases, replaced by transdisciplinarity. Transdisciplinarity in turn supposes the existence of a specific language of concepts and models. It should be understandable and usable by any specialist in need to collaborate with a variety of colleagues of other fields. Such a language has emerged since 1950 as Cybernetics and Systemics (or so‐called systems sciences or sciences of complexity). It is still becoming richer and better connected internally as it steadily acquires new conceptual tools adequated to the study of dynamic, simultaneous, multiple and interdependent interactions in complex issues. Copyright © 2006 John Wiley & Sons, Ltd.
Systemic reflections on our past, present and future
Authors: Gregory Amanda 
Published: December 2006

AbstractThis paper is about our ability to control the organizations that we have either created or inherited. The discussion draws on work by Luhmann, on time and social autopoiesis, and Zadek, on creating civil corporations. It is proposed that the ability to demonstrate resistance differentiates the autopoietic model from earlier systems models and that this ability is mediated through the system's capacity for intelligence based on its distinction and learning from other systems in its environment. Such a view introduces the opportunity for organizations to shift away from rationalism, involving structural barriers and limitations, to a more integrated form of being in the Future. Copyright © 2006 John Wiley & Sons, Ltd.
Creative holism: a critical systems approach to complex problem situations
Authors: Jackson Michael C. 
Published: December 2006

AbstractThe 49th Annual Meeting of the International Society for the Systems Sciences had, as its theme, ‘the potential impacts of systemics on society’. As my contribution to this, I want to discuss why I think a critical systems approach called ‘creative holism’ can help managers address complex problem situations. As is frequently stated, managers today face increasing complexity, change and diversity. Furthermore, the solutions they are offered to help them cope in this situation rarely seem to work. In this paper, it is argued that those solutions fail because they are not holistic or creative enough. The benefits to be gained from holism and creativity (in a systemic sense) are outlined, and a practical approach, ‘creative holism’, is specified which aims to better equip managers to deal with complex problem situations. If the argument is right then systemics has the potential to have both a significant and a beneficial impact upon society in the years to come. Copyright © 2006 John Wiley & Sons, Ltd.
System dynamics and the evolution of the systems movement
Authors: Schwaninger Markus 
Published: December 2006

AbstractThe purpose of this contribution is to give an overview of the role of System Dynamics (SD) in the context of the evolution of the systems movement. This is necessary because SD is often erroneously taken as the systems approach as such, not as part of it. It is also requisite to show that the processes of the evolution of both SD in particular and the Systems Movement as a whole are intimately linked and intertwined. Finally, in view of the purpose of the paper the actual and potential relationships between SD and the other strands of the systems movement are worked out. This way, complementarities and synergies are identified. Copyright © 2006 John Wiley & Sons, Ltd.
Systemic methodologies in regional sustainable development
Authors: Fuentes Honorato C. Teissier 
Published: December 2006

AbstractSynthesized from a PhD thesis written at the Université du Québec à Chicoutimi, Canada, this article explains how systemic methodologies are implemented and applied to help the south‐eastern region of Coahuila state, Mexico; focusing on problems of a real sustainable development process and long‐term system comprehension under an evolutionary perception. Copyright © 2006 John Wiley & Sons, Ltd.
An essay on Kenneth E. Boulding's General Systems Theory: the skeleton of science
Authors: Wilby Jennifer 
Published: December 2006

AbstractThe purpose of this paper is to discuss the hierarchy of system complexity that Kenneth E. Boulding proposed in the article General Systems Thinking—The Skeleton of Science, originally published in Management Science, 2, (1956, pp. 197–208) and to explore the implications of the Skeleton for systems theory and practice as it currently stands. The nine‐level Skeleton of Science is presented and discussed with reference to four perceived underlying frameworks within the Skeleton. The implications of the Skeleton and suggested future directions for further research are also presented. Copyright © 2006 John Wiley & Sons, Ltd.
Exploring public–private partnerships through knowledge cybernetics
Authors: Yolles Maurice , Iles Paul 
Published: December 2006

AbstractKnowledge cybernetics operates as a social geometry and incorporates joint alliance theory. Using its schema, an exploration is made of how in a globalizing economy governments may seek to enhance their social infrastructural provision by coupling private corporations into public services and producing public–private partnerships. This paper will explore and explain the systemic needs of such partnerships, their ontological and epistemological pathologies, and their ethical and ideological contradictions. Despite the unlikelihood of partnerships functioning effectively to the benefit of social provision, the persistence of the use of private provision in the delivery of social goods may have an ideological explanation. Copyright © 2006 John Wiley & Sons, Ltd.
Concentration of some elements in the Adriatic coastal sea sediments. Case study: the Kvarner Bay
Authors: Valković V. , Obhod̄aš J. , Črnjar M. 
Published: December 2006

AbstractThe analyses of 15 chemical elements in 70 surface sediment samples along the coast of the Kvarner Bay and its islands were carried out on the grain fractions < 2 mm by using the energy‐dispersive x‐ray fluorescence (EDXRF) analysis. The range of the measured elemental concentrations in mg/kg were: K (1121–14 240), Ca (7200–261 600), Ti (81–4178), Cr (6–169), Mn (17–534), Fe (310–34 800), Ni (6–212), Cu (5–12 640), Zn (12–11 860), As (1.1–524.4), Br (14–373), Rb (2–151), Sr (112–1815), Y (8–80) and Pb (3–1430). The sediment concentrations of the biocidal elements Cu, Zn, As and Pb, usual components of available commercial antifouling paints, were found to be several orders of magnitude greater than the background values in sediments close to the marina or shipyard service areas. Contour maps of concentrations in the surface sediment layer for these four elements were produced, indicating the level and range of sediment contamination from the pollution sources. Factor analysis (FA) applied to the Kvarner Bay dataset has confirmed that among the measured elements, Cu, Zn, As and Pb contribute to the anthropogenic factor and the others to the two natural background factors.In order to investigate the negative environmental influence of marinas, shipyards and ports in more detail, the distributions of the element concentrations in the core and surface sediment samples were studied on a small geographical scale with the example of the Punat Bay and its shipyard, determined as contaminated zones in the Kvarner Bay. It was proved that the anthropogenic loads of the elements Cu, Zn and Pb from the local marina and the shipyard are the main sources of the bay pollution. Protection and remediation measures for the Croatian marinas, shipyards and small harbors could be proposed on the basis of these results. Copyright © 2006 John Wiley & Sons, Ltd.
Sb2Hg3GaBr4: A New Supramolecular Framework Structure with [Sb2Hg4/2]±0 Building Blocks Isosteric to Distibane
Authors: Schlirf J. , Deiseroth H. J. 
Published: December 2006

AbstractSb2Hg3GaBr4 is a new air stable transparent reddish solid that crystallizes in space group Pnma (No. 62, Z = 8) with the lattice constants a = 1375.49(8) pm, b = 1269.0(1) pm, c = 1478.19(9) pm. The title compound represents a new structure type based on a cationic framework $^{3}_{\infty}\rm [Sb_{2}Hg_{3}]^{+}$ of a significantly modified Millons base type. Structural building blocks of the cationic partial structure are well known tetrahedral [SbHg4/2]+ groups and unprecedented formally neutral [Sb2Hg4/2]±0 units in a 2:1 ratio. The [Sb2Hg4/2]±0 units contain covalent Sb‐Sb bonds (d = 285.6 pm) and are isosteric with Distibane Sb2H4 in a staggered conformation. Structural consequences of the lone pairs located at the Sb atoms of the [Sb2Hg4/2]±0 units are discussed. The charge of the cationic framework is balanced by disordered anions in suitable cavities. They appear as tetrahedral [GaBr4]− but correspond most likely to a superposition of bitetrahedral apex sharing [Ga2Br7]− and isolated Br−.
Synthesis and Structural Characterization of two Novel Copper(I) Complexes with Oxygen Donor
Authors: Cao Qian‐Yong , Gan Xin , Fu Wen‐Fu 
Published: December 2006

AbstractTwo novel copper(I) complexes with Cu‐O bonds, [Cu2L2(PPh3)2](BF4)2 (1) and [Cu(L)(dppeo)](BF4) (2) (L = 6‐(4‐diethylmethylphosphonatephenyl)‐2,2′‐bipyridine, dppeo = bis(diphenylphosphino)ethane monoxide), have been prepared and their structures characterized. In the binuclear complex 1, the ligand L serves as tridentate donor with the N, N′ and O as coordination atoms, and the two CuI atoms are bridged through both P = O donor atoms in different ligand L with a triphenylphosphine molecule as auxiliary ligand. While in mononuclear complex 2, both ligands L and dppeo behave as bidentate with N∧N from L and P∧O from dppeo chelating to CuI atom.