bluuebunny/crossref_metadata_2025 huggingface dataset:
A trichloro-bridged binuclear ruthenium complex with 1,1,1-tris(diphenylphosphinomethyl)ethane
Authors: Seok Won K. , Zhang Li J. , Karaghiosoff Konstantin , Klapötke Thomas M. , Mayer Peter
Published: November 2003

The trichloro-bridged dinuclear RuII complex tri-μ-chloro-bis{[1,1,1-tris(diphenylphosphinomethyl)ethane-κ3
P,P′,P′′]ruthenium(II)} hexafluorophosphate ethanol solvate, [Ru2Cl3(tripod)2]PF6·C2H6O, containing the tripod [1,1,1-tris(diphenylphosphinomethyl)ethane, C41H39P3] ligand, was unexpectedly obtained from the reaction of [RuIIICl3(tripod)] with 1,4-bis(diphenylphosphino)butane (dppb), followed by precipitation with NH4PF6. The magnetic moment of the compound at room temperature indicates that the dinuclear [Ru2(μ-Cl)3(tripod)2]+ cation is diamagnetic. A single-crystal X-ray structure determination revealed that the two Ru atoms are bridged by the three Cl atoms. The coordination sphere of each Ru atom is completed by the three P atoms of a tripod ligand. The two P3Ru units are exactly eclipsed, while the bridging Cl atoms are staggered with respect to the six P atoms. The Ru...Ru distance is 3.3997 (7) Å and the mean Cl—Ru—Cl bond angle is 77.7°.
Bis(μ-di-2-pyridylaminato 1-oxide)bis[(trifluoroacetato)copper(II)] acetonitrile disolvate
Authors: Zeng Xi-Rui , Fang Xiao-Niu , Peng Shie-Ming , Lin Hsiu-Mei
Published: November 2003

The crystal structure of the title compound, [Cu2(C2F3O2)2(C10H8N3O)2]·2CH3CN, contains discrete [Cu2(CF3COO)2(O-dpa)2] molecules (O-dpaH is di-2-pyridylamine 1-oxide) which have imposed crystallographic twofold symmetry and an acetonitrile molecule of solvation. The O-dpa− ligand is both bidentate and bridging, linking two Cu atoms with a separation of 3.4270 (11) Å. Each Cu atom is surrounded by four coordinated atoms that are almost coplanar, with dimensions Cu—N = 1.940 (2) and 1.984 (3) Å, and Cu—O = 1.912 (2) and 1.945 (2) Å.
[(1R,2R)-1,2-Diaminocyclohexane-κ2
N,N′](α-diimine-κ2
N,N′)platinum(II) bis(hexafluorophosphate), where α-diimine is 2,2′-bipyridine and 1,10-phenanthroline
Authors: Koshiyama Tamami , Kato Masako
Published: November 2003

The title PtII complexes, viz. (2,2′-bipyridine-κ2
N,N′)[(1R,2R)-1,2-diaminocyclohexane-κ2
N,N′]platinum(II) bis(hexafluorophosphate), [Pt(C6H14N2)(C10H8N2)](PF6)2, and [(1R,2R)-1,2-diaminocyclohexane-κ2
N,N′](1,10-phenanthroline-κ2
N,N′)platinum(II) bis(hexafluorophosphate), [Pt(C6H14N2)(C12H8N2)](PF6)2, containing an aromatic α-diimine and a non-planar diaminocyclohexane, both form a ladder-type structure, which is constructed via loose π–π stacking on the α-diimine ligands and hydrogen bonding between the cyclic amines and the counter-anions. In the former compound, there are two independent complex cations, both of which have a twofold axis through the Pt atom.
N,N-Dimethyl-N′-[(1E,2E)-3-(4-nitrophenyl)prop-2-enylidene]benzene-1,4-diamine and N,N-dimethyl-4-[(1E,3E)-4-(4-nitrophenyl)buta-1,3-dienyl]-1-naphthylamine
Authors: Nesterov Volodymyr V. , Suina Andrea , Antipin Mikhail Yu. , Timofeeva Tatiana V. , Barlow Stephen , Marder Seth R.
Published: November 2003

Syntheses and X-ray structural investigations have been carried out for the two title compounds, viz. C17H17N3O2, (I), and C22H20N2O2, (II). The molecular skeleton of (I) is slightly non-planar; the dihedral angles between the conjugated linkage and the p-(dimethylamino)phenyl ring, and between the linkage and the p-nitrophenyl ring are 13.0 (2) and 13.8 (2)°, respectively. The dihedral angle between the slightly pyramidal dimethylamine substituent and the aromatic ring is 23.3 (1)°. The molecular skeleton of (II) is not planar; the dihedral angles between the conjugated linkage and the naphthalene ring, and between the linkage and the substituted phenyl ring are 36.1 (2) and 2.7 (3)°, respectively. The dimethylamine substituent in (II) has a pyramidal geometry; the dihedral angle between this substituent and the naphthalene ring is 71.7 (1)°. The dihedral angle between the nitro group and the plane of the substituted phenyl ring is 9.0 (3)°. There is a weak intermolecular C—H...O hydrogen bond in the crystal structure of (II), which links the molecules into centrosymmetric dimers. Molecular mechanics calculations of molecular conformations have shown that the crystal environment influences the conformation more in (I) than in (II).
2-{[Tris(hydroxymethyl)methyl]aminomethylene}cyclohexa-3,5-dien-1(2H)-one and its 6-hydroxy and 6-methoxy derivatives
Authors: Odabas˛ogˇlu Mustafa , Albayrak Çigˇdem , Büyükgüngör Orhan , Lönnecke Peter
Published: November 2003

The title compounds, 2-{[tris(hydroxymethyl)methyl]aminomethylene}cyclohexa-3,5-dien-1(2H)-one, C11H15NO4, (I), 6-hydroxy-2-{[tris(hydroxymethyl)methyl]aminomethylene}cyclohexa-3,5-dien-1(2H)-one, C11H15NO5, (II), and 6-methoxy-2-{[tris(hydroxymethyl)methyl]aminomethylene}cyclohexa-3,5-dien-1(2H)-one, C12H17NO5, (III), adopt the keto–amine tautomeric form, with the formal hydroxy H atom located on the N atom, and the NH group and oxo O atom display a strong intramolecular N—H...O hydrogen bond. The N—H...O hydrogen-bonded rings are almost planar and coupled with the cyclohexadiene rings. The carbonyl O atoms accept two other H atoms from the alcohol groups of adjacent molecules in (I), and one from the alcohol and one from the phenol group in (II), but from only one alcohol H atom in (III).
A new hydrated ammonium hydroxyborate, (NH4)2[B10O14(OH)4]·H2O
Authors: Li Lin-Yan , Li Guo-Bao , Xiong Ming , Wang Ying-Xia , Lin Jian-Hua
Published: November 2003

The structure of a new synthetic compound, diammonium tetrahydroxydecaborate monohydrate, has been determined by single-crystal X-ray diffraction. It crystallizes in triclinic space group P\overline 1 and all atoms occupy general sites. The title compound is composed of [B10O15(OH)4]4− ions as the fundamental building blocks, and these are linked end-to-end by sharing two common O atoms, thus producing infinite chains of composition [B10O14(OH)4]
n

2n–. These chains are linked by hydrogen bonds, thus forming borate sheets. Water molecules and ammonium ions between these sheets connect adjacent sheets via hydrogen bonds.
1-(4-Chlorophenylsulfanyl)-2-nitro-4-(trifluoromethyl)benzene and 1-(4-chlorophenylsulfanyl)-4-nitro-2-(trifluoromethyl)benzene
Authors: Lynch Daniel E. , McClenaghan Ian
Published: November 2003

Two chemical isomers of 3-nitrobenzotrifluoride, namely 1-(4-chlorophenylsulfanyl)-2-nitro-4-(trifluoromethyl)benzene, C13H7ClF3NO2S, (I), and 1-(4-chlorophenylsulfanyl)-4-nitro-2-(trifluoromethyl)benzene, C13H7ClF3NO2S, (II), have been prepared and their crystal structures determined with the specific purpose of forming a cocrystal of the two. The two compounds display a similar conformation, with dihedral angles between the benzene rings of 83.1 (1) and 76.2 (1)°, respectively, but (I) packs in P\overline 1 while (II) packs in P21/c, with C—H...O interactions. No cocrystal could be formed, and it is suggested that the C—H...O associations in (II) prevent intermolecular mixing and promote phase separation.
Four cytotoxic N4-substituted thiosemicarbazones derived from 2-hydroxynaphthalene-1-carboxaldehyde
Authors: Bernhardt Paul V. , Caldwell Lorraine M. , Lovejoy David B. , Richardson Des R.
Published: November 2003

The X-ray crystal structures are reported of four novel and potentially O,N,S-tridentate donor ligands that demonstrate antitumour activity. These ligands are 1-[(4-methylthiosemicarbazono)methyl]-2-naphthol, C13H13N3OS, (III), 1-[(4-ethylthiosemicarbazono)methyl]-2-naphthol, C14H15N3OS, (IV), 1-[(4-phenylthiosemicarbazono)methyl]-2-naphthol, C18H15N3OS, (V), and 1-[(4,4-dimethylthiosemicarbazono)methyl]-2-naphthol dimethyl sulfoxide solvate, C14H15N3OS·C2H6OS, (VI). These chelators are N4-substituted thiosemicarbazones, each based on the same parent aldehyde, namely 2-zhydroxynaphthalene-1-carboxaldehyde isonicotinoylhydrazone. Conformational variations within this series are discussed in relation to the optimum conformation for metal-ion binding.
Two polymorphic forms of 2,5-bis(4-methoxycarbonylphenyl)-1,3,4-oxadiazole
Authors: Reck Günter , Orgzall Ingo , Schulz Burkhard , Dietzel Birgit
Published: November 2003

The title compound [systematic name: dimethyl 4,4′-(1,3,4-oxadiazole-2,5-diyl)diphenylenedicarboxylate], C18H14N2O5, crystallizes under similar conditions in two different orthorhombic crystalline forms. In both forms, the molecule consists of two equivalent parts. In form 1, these parts are related by a twofold axis of space group Pbcn, and in form 2, by a mirror plane of space group Cmc21. The O atom of the oxadiazole ring occupies a special position on the twofold axis and on the mirror plane in forms 1 and 2, respectively.
Geometric isomers of chloro(6-methyl-1,4,8,11-tetraazacyclotetradecane-6-amine)cobalt(III) tetrachlorozincate(II)
Authors: Bernhardt Paul V. , Macpherson Brendan P.
Published: November 2003

The crystal structures of a pair of cis and trans isomers of the macrocyclic chloropentaamine title complex, as their tetrachlorozincate(II) salts, [CoCl(C11H27N5)][ZnCl4], are reported. The two distinct isomeric forms lead to significant variations in the Co—N bond lengths and, furthermore, hydrogen bonding between the complex ions is influenced by the folded (cis) or planar (trans) conformations of the coordinated ligand.
Bis(2-chloro-5-methylpyridine-κN)bis(nitrato-κ2
O,O′)copper(II)
Authors: Xuan Richeng , Li Meichao , Wan Yuehua
Published: November 2003

In the molecule of the title compound, [Cu(NO3)2(C6H6ClN)2], the Cu atom lies on an inversion centre and is six-coordinated by two pyridine N atoms and four nitrate O atoms in trans positions. The nitrate acts as an unsymmetrical bidentate ligand. The coordination geometry is octahedral, with the Cu—N and the two Cu—O distances being 1.9939 (16), 2.0246 (16) and 2.4866 (19) Å, respectively. There are five types of C—H...O hydrogen bonds. Two of these generate two-dimensional molecular networks in the direction of the a axis, and the others connect adjacent molecular networks.
A zirconium zwitterion containing a caged amine H atom
Authors: Nielson Alastair J. , Shen Chaohong , Waters Joyce M.
Published: November 2003

The crystallographically centrosymmetric zwitterion bis[tris(3,5-dimethyl-2-oxidobenzyl-κO)ammonium]zirconium(IV) crystallizes as the chloroform disolvate, [Zr(C27H31NO3)2]·2CHCl3, with the two molecules of chloroform closely associated with two of the aromatic rings. The Zr atom has a distorted octahedral geometry with three phenoxy O atoms from each of the two ligands coordinated to it. Charge balance is maintained by protonation of each N atom, which then forms intramolecular hydrogen-bonding interactions to all three adjacent O atoms.
Helping children apply their knowledge to their behavior on a dimension‐switching task
Authors: Kirkham Natasha Z. , Cruess Loren , Diamond Adele
Published: November 2003

To investigate why 3‐year‐olds have difficulty in switching sorting dimensions, children of 3 and 4 years were tested in one of four conditions on Zelazo's card sort task: standard, sleeve, label and face‐up. In the standard condition, children were required to sort blue‐truck and red‐star cards under either a blue‐star or red‐truck model card, first by color or shape, and then by the other dimension. Here 3‐year‐olds sorted correctly until the dimension changed; they continue to sort by the initial dimension. The sleeve condition (placing the sorting cards in an envelope prior to sorting) had little effect. In the label condition, the child labeled the relevant sorting dimension on each trial. Most 3‐year‐olds succeeded; evidently their labeling helped them refocus their attention, overcoming ‘attentional inertia’ (the pull to continue attending to the previously relevant dimension). In the face‐up condition, attentional inertia was strengthened because sorted cards were left face‐up; 4‐year‐olds performed worse than in the standard condition. We posit that attentional inertia is the core problem for preschoolers on the card sort task.
Late talkers show no shape bias in a novel name extension task
Authors: Jones Susan S.
Published: November 2003

By 2½ years of age, children typically show a shape bias in object naming – that is, they extend object names mostly to new instances with the same shape. The acquisition of a shape bias is related to a marked increase in the rate of object name learning. This study asks whether, conversely, children who do not readily acquire new object names lack a shape bias. Twelve 2‐ to 3‐year‐old ‘late talkers’– children whose total vocabularies rank below the 30th percentile for their age – were compared with age‐matched children with larger vocabularies in a novel object name extension task. The controls extended novel names across novel objects with the same shape. The late talkers showed no group perceptual bias, but many individuals extended novel names across objects with the same surface texture. The implications of the results both for the role of attentional biases in object name learning and for the etiology of some late talking are discussed.
The basis of preference for lexical words in 6‐month‐old infants
Authors: Shi Rushen , Werker Janet F.
Published: November 2003

Six‐month‐old English‐learning infants have been shown to prefer English lexical over English grammatical words. The preference is striking because there are few grammatical words in total number but each occurs far more frequently in input speech than any individual lexical word. This could be because lexical words are universally more salient and interesting acoustic and phonological forms than are grammatical words. Alternatively, familiarity may play a role since infants may know some specific lexical words. Here we explore the first possibility by testing Chinese‐learning infants’ response to English lexical and grammatical words. These infants, who had virtually no prior exposure to English and thus were unfamiliar with any English words, nevertheless preferred to listen to English lexical words, as in the case of English‐learning infants. This finding increases the plausibility that it is the acoustic and phonological salience of lexical words that determines the preference for lexical words in infants.
Problems with the Seeing = Knowing Rule
Authors: Friedman Ori , Griffin Richard , Brownell Hiram , Winner Ellen
Published: November 2003

The view that children understand the mind via a coherent theory is supported by evidence that children rigidly follow a Seeing = Knowing Rule: seeing, and only seeing, leads to knowing. This paper presents two kinds of evidence that children do not follow this rule. First, we critically review previous findings that children neglect the role of inference and argue that these studies do not in fact support the view that children follow a Seeing = Knowing Rule. We then present two studies in which children who correctly attributed ignorance and false belief to an observer in a false belief task also attributed ignorance (Study 1) and false belief (Study 2) in true belief tasks. These findings demonstrate that children sometimes attribute ignorance and false belief to an observer who is granted visual access, an outcome that should not occur if children rigidly follow the Seeing = Knowing Rule. We end by discussing some problems associated with modifying the Seeing = Knowing Rule to account for children's failure on the true belief task.
Biological bases of face preference in 6‐week‐old infants
Authors: Blass Elliott M. , Camp Carole Ann
Published: November 2003

Six‐week‐old infants (N =40) who started the experiment in either a calm or crying state, received sucrose from an experimenter, while in eye contact with her. Sucrose was delivered either by syringe or on a pacifier. After 3.5 min., the experimenter retired, the mother came into the test room and placed her infant over her shoulder en face with a video camera. The experimenter and a confederate, both dressed identically, sat in front of and slightly to either side of the infant and the infant could choose to look at either experimenter. To minimize position bias, experimenters switched sides every 30 sec. To maintain a stable level of infant attention, they simultaneously called the baby's name at 10 sec. intervals. When an infant looked at one or the other experimenters, she raised her thumb in camera view. Only crying infants who sucked a sweet pacifier showed a preference for their experimenter. As a group none of the other infants did so. However, there was a wide distribution of sucking times in calm week 6 infants. Choice was linearly related to sucking duration. Infants who sucked for substantial periods of time, showed a strong preference for the experimenter. Those who sucked for minimal periods of time strongly preferred the confederate. Based on these findings and ones from 9‐ and 12‐week‐old infants, a model is presented in which preference in this experimental paradigm is determined by idealized levels of central activation. These levels may be inferred from the normal crying function at a particular age.
Natural Allies? Mapping the Relationship between Conservatism and Environmentalism
Authors: Pilbeam Bruce
Published: November 2003

This article examines the relationship between conservatism and environmentalism, including the viability of an eco-conservative ideology. The discussion emphasizes two major points. First, that there is much greater shared ground between greens and conservatives than is often recognized. Yet second, that there are nonetheless significant obstacles to any harmonious alliance between the two. However, what is also shown is that these obstacles are not necessarily those most commonly cited.
Human Rights and Modern Liberalism: A Critique
Authors: Langlois Anthony J.
Published: November 2003

The idea of human rights has become one of the central moral notions of both the theory and practice of international politics. While its foundation and future in the practice of politics looks bright, it is an idea that still causes great trouble at the theoretical level. What are human rights? Why do we have them? To what should we attribute the authority of their moral claims? The theorist Michael Freeman has suggested one theory that by addressing such questions may serve as a foundation for human rights. His theory, however, ends by begging the questions it set out to answer.
Disparities in Prosperity
Authors: Gudgin Graham
Published: November 2003

Regional differences in prosperity and productivity have recently been rising up the government's priority list as matters requiring serious attention. Wide existing disparities partly explain the government's desire to introduce regional assemblies and to propose that most of these should move from a consultative to an elected basis. Of course, the introduction of devolution to Scotland, Wales and Northern Ireland in 1998 has increased the desire within English regions to reproduce the perceived advantages of the devolved regions. In this article, Graham Gudgin1 looks at the extent and causes of differences in regional prosperity.
Mediating the Economic Pulses: The International Connection in Portuguese Higher Education
Authors: Teixeira Pedro , Amaral Alberto , Rosa Maria João
Published: November 2003

Portugal, as a small and increasingly integrated European economy, has been influenced by some of the major trends that defined the agenda of higher education policy in recent decades. Its backwardness – notably in terms of skills, education, and training – has frequently prompted a focus of attention on its international counterparts, particularly those in Europe, in search of affinities, solutions and errors to avoid. The search for guidance has also created an opportunity for the intervention of international organisations. Until Portugal joined the European Union (EU) in 1986, the Organisation for Economic Cooperation and Development (OECD) and the World Bank were the main agencies playing this role. Henceforth, those institutions lost some influence, and the European dimension gained increasing prominence. This article discusses the role of those international organisations in the definition of priorities for Portuguese higher education policy in recent decades, and provides a general overview of the outside perceptions of the Portuguese situation as understood by these international organisations. In particular, the article focuses on those interventions that promoted the influence of market mechanisms in the Portuguese higher education system by emphasising the need for higher education institutions (HEIs) to strive for increased economic responsiveness.
Reviews
Authors: Fuller Alison , Pritchard Rosalind , Trowler Paul
Published: November 2003

Books reviewed in this article:

L. Archer, M. Hutchings and A. Ross, with C. Leathwood, R. Gilchrist and D. Phillips, Higher Education and Social Class: Issues of Exclusion and Inclusion

John Brennan and Tarla Shah, Managing Quality in Higher Education: An International Perspective on Institutional Assessment and Change

R. Taylor, J. Barr and T. Steele, For a Radical Higher Education: After Postmodernism
Empathy, Ways of Knowing, and Interdependence as Mediators of Gender Differences in Attitudes Toward Hate Speech and Freedom of Speech
Authors: Cowan Gloria , Khatchadourian Désirée
Published: November 2003

Women are more intolerant of hate speech than men. This study examined relationality measures as mediators of gender differences in the perception of the harm of hate speech and the importance of freedom of speech. Participants were 107 male and 123 female college students. Questionnaires assessed the perceived harm of hate speech, the importance of freedom of speech, empathy, relational and collective interdependence, and connected and separate ways of knowing. Gender differences were found for the harm of hate speech, freedom of speech, empathy, and separate learning as a way of knowing. Women were more negative regarding the harm of hate speech and regarded freedom of speech as less important than men. Additionally, the perceived harm of hate speech was positively associated with empathy, connected knowing, and interdependence, and freedom of speech was positively associated with separate learning and negatively with empathy. Empathy mediated gender differences in the perceived harm of hate speech, and separate learning mediated gender differences in the importance of freedom of speech.
Factors Associated with Jealousy Over Real and Imagined Infidelity: An Examination of the Social-Cognitive and Evolutionary Psychology Perspectives
Authors: Harris Christine R.
Published: November 2003

Three hundred fifty-eight undergraduates completed anonymous questionnaires regarding jealousy over a mate's infidelity. More men than women predicted that sexual infidelity would be worse than emotional infidelity when given the forced-choice hypothetical measures used in previous work. When some of the implications of hypothetical infidelity were controlled, the gender difference disappeared. One hundred twenty-seven participants reported having actual experience with a mate's infidelity. The two genders did not differ in degree of focus on the sexual versus emotional aspects of a mate's real betrayal. Sexual jealousy was correlated with having a greater number of sexual relationships and, for men but not women, with placing higher importance on sex in dating relationships. The results are discussed from a social-cognitive perspective.
Scanning Probe Evolution in Biology
Authors: Hörber J. K. H. , Miles M. J.
Published: November 2003

Twenty years ago the first scanning probe instrument, the scanning tunneling microscope, opened up new realms for our perception of the world. Atoms that had been abstract entities were now real objects, clearly seen as distinguishable individuals at particular positions in space. A whole family of scanning probe instruments has been developed, extending our sense of touching to the scale of atoms and molecules. Such instruments are especially useful for imaging of biomolecular structures because they can produce topographic images with submolecular resolution in aqueous environments. Instruments with increased imaging rates, lower probe-specimen force interactions, and probe configurations not constrained to planar surfaces are being developed, with the goal of imaging processes at the single-molecule level—not only at surfaces but also within three-dimensional volumes—in real time.
A Reservoir of Nitrate Beneath Desert Soils
Authors: Walvoord Michelle A. , Phillips Fred M. , Stonestrom David A. , Evans R. Dave , Hartsough Peter C. , Newman Brent D. , Striegl Robert G.
Published: November 2003

A large reservoir of bioavailable nitrogen (up to ∼10
4
kilograms of nitrogen per hectare, as nitrate) has been previously overlooked in studies of global nitrogen distribution. The reservoir has been accumulating in subsoil zones of arid regions throughout the Holocene. Consideration of the subsoil reservoir raises estimates of vadose-zone nitrogen inventories by 14 to 71% for warm deserts and arid shrublands worldwide and by 3 to 16% globally. Subsoil nitrate accumulation indicates long-term leaching from desert soils, impelling further evaluation of nutrient dynamics in xeric ecosystems. Evidence that subsoil accumulations are readily mobilized raises concern about groundwater contamination after land-use or climate change.
Mars-Like Soils in the Atacama Desert, Chile, and the Dry Limit of Microbial Life
Authors: Navarro-González Rafael , Rainey Fred A. , Molina Paola , Bagaley Danielle R. , Hollen Becky J. , de la Rosa José , Small Alanna M. , Quinn Richard C. , Grunthaner Frank J. , Cáceres Luis , Gomez-Silva Benito , McKay Christopher P.
Published: November 2003

The Viking missions showed the martian soil to be lifeless and depleted in organic material and indicated the presence of one or more reactive oxidants. Here we report the presence of Mars-like soils in the extreme arid region of the Atacama Desert. Samples from this region had organic species only at trace levels and extremely low levels of culturable bacteria. Two samples from the extreme arid region were tested for DNA and none was recovered. Incubation experiments, patterned after the Viking labeled-release experiment but with separate biological and nonbiological isomers, show active decomposition of organic species in these soils by nonbiological processes.
Evidence for Ozone Formation in Human Atherosclerotic Arteries
Authors: Wentworth Paul , Nieva Jorge , Takeuchi Cindy , Galve Roger , Wentworth Anita D. , Dilley Ralph B. , DeLaria Giacomo A. , Saven Alan , Babior Bernard M. , Janda Kim D. , Eschenmoser Albert , Lerner Richard A.
Published: November 2003

Here, we report evidence for the production of ozone in human disease. Signature products unique to cholesterol ozonolysis are present within atherosclerotic tissue at the time of carotid endarterectomy, suggesting that ozone production occurred during lesion development. Furthermore, advanced atherosclerotic plaques generate ozone when the leukocytes within the diseased arteries are activated in vitro. The steroids produced by cholesterol ozonolysis cause effects that are thought to be critical to the pathogenesis of atherosclerosis, including cytotoxicity, lipid-loading in macrophages, and deformation of the apolipoprotein B-100 secondary structure. We propose the trivial designation “atheronals” for this previously unrecognized class of steroids.
African Droughts and Dust Transport to the Caribbean: Climate Change Implications
Authors: Prospero Joseph M. , Lamb Peter J.
Published: November 2003

Great quantities of African dust are carried over large areas of the Atlantic and to the Caribbean during much of the year. Measurements made from 1965 to 1998 in Barbados trade winds show large interannual changes that are highly anticorrelated with rainfall in the Soudano-Sahel, a region that has suffered varying degrees of drought since 1970. Regression estimates based on long-term rainfall data suggest that dust concentrations were sharply lower during much of the 20th century before 1970, when rainfall was more normal. Because of the great sensitivity of dust emissions to climate, future changes in climate could result in large changes in emissions from African and other arid regions that, in turn, could lead to impacts on climate over large areas.
Quantum Coherence in an Exchange-Coupled Dimer of Single-Molecule Magnets
Authors: Hill S. , Edwards R. S. , Aliaga-Alcalde N. , Christou G.
Published: November 2003

A multi– high-frequency electron paramagnetic resonance method is used to probe the magnetic excitations of a dimer of single-molecule magnets. The measured spectra display well-resolved quantum transitions involving coherent superposition states of both molecules. The behavior may be understood in terms of an isotropic superexchange coupling between pairs of single-molecule magnets, in analogy with several recently proposed quantum devices based on artificially fabricated quantum dots or clusters. These findings highlight the potential utility of supramolecular chemistry in the design of future quantum devices based on molecular nanomagnets.
Mammalian Brain Morphogenesis and Midline Axon Guidance Require Heparan Sulfate
Authors: Inatani Masaru , Irie Fumitoshi , Plump Andrew S. , Tessier-Lavigne Marc , Yamaguchi Yu
Published: November 2003

Heparan sulfate (HS) is required for morphogen signaling during
Drosophila
pattern formation, but little is known about its physiological importance in mammalian development. To define the developmental role of HS in mammalian species, we conditionally disrupted the HS-polymerizing enzyme EXT1 in the embryonic mouse brain. The EXT1-null brain exhibited patterning defects that are composites of those caused by mutations of multiple HS-binding morphogens. Furthermore, the EXT1-null brain displayed severe guidance errors in major commissural tracts, revealing a pivotal role of HS in midline axon guidance. These findings demonstrate that HS is essential for mammalian brain development.
Culture Among Sperm Whales?
Authors: Boyd Ian L.
Published: November 2003

Sperm Whales
Social Evolution in the Ocean.
By Hal Whitehead
. University of Chicago Press, Chicago, 2003. 455 pp. $80. ISBN 0-226-89517-3. Paper, $30. ISBN 0-226-89518-1.

Building on his nearly two decades of field research with sperm whales, Whitehead describes their habitat, biology, and ecology and considers how the ocean environment has shaped their social behavior and cultural evolution.
Degradation of Cross-Linked and Non-Cross-Linked Arabinoxylans by the Intestinal Microbiota in Children
Authors: Hopkins Mark J. , Englyst Hans N. , Macfarlane Sandra , Furrie Elizabeth , Macfarlane George T. , McBain Andrew J.
Published: November 2003

In humans, nonstarch polysaccharides (NSP), such as arabinoxylans (AX), are not digested in the upper gut and provide fermentable carbon sources for bacteria growing in the large bowel. Despite the ubiquity of AX in nature, the microbiologic and physiologic consequences of AX digestion in the gut are poorly understood. In this study, we investigated the breakdown of ferulic acid-cross-linked AX (AXF) and non-cross-linked AX in children's intestinal microbiotas, using starch as a readily fermentable polysaccharide for comparative purposes. The experiments were performed using pH-controlled fermentation vessels under anaerobic conditions. The results demonstrated that there was variation in the metabolism of these polysaccharides by colonic microbiotas. AX was always degraded more slowly than starch, while ferulic acid cross-linking reduced the rate of AX fermentation, as shown by fermentation product measurements. Starch digestion was associated with significant acetate and butyrate production, whereas AX breakdown resulted in increased propionate formation. In general, the presence of fermentable carbohydrate significantly increased the total anaerobe counts and eubacterial rRNA concentrations (
P
< 0.01), while non-cross-linked AX digestion was principally associated with increased viable counts of
Bacteroides fragilis
group organisms, which was supported by increases in
Bacteroides
-
Porphyromonas
-
Prevotella
group rRNA (
P
< 0.01). Starch was considerably more bifidogenic than AX in these fermentations. In conclusion, in this study we found that the effects of AX and AXF on the microbial ecology and metabolism of intestinal microbiotas are similar in children and adults.
MultilocusSequence Typing for Comparison of Veterinary and HumanIsolates of
Campylobacter jejuni
Authors: Manning Georgina , Dowson Christopher G. , Bagnall Mary C. , Ahmed If H. , West Malcolm , Newell Diane G.
Published: November 2003

Multilocus
sequence typing (MLST) has been applied to 266
Campylobacter
jejuni
isolates, mainly from veterinary sources, including cattle,
sheep, poultry, pigs, pets, and the environment, as well as isolates
from human cases of campylobacteriosis. The populations of veterinary
and human isolates overlap, suggesting that most veterinary sources
should be considered reservoirs of pathogenic campylobacters. There
were some associations between source and sequence type complex,
indicating that host or source adaptation may exist. The pig isolates
formed a distinct group by MLST and may well represent a potential
pig-adapted clone of
C. jejuni
. A subset
(
n
= 82) of isolates was reanalyzed with a second MLST
scheme which provided a unique set of isolates that had been analyzed
at a total of 12 loci. The distribution of isolates among the complexes
in each of the two schemes was similar but not identical. In addition
to isolates from human outbreaks, one group of isolates that were not
epidemiologically linked was also identical at all 12 loci. This group
of isolates is believed to represent another stable strain of
C.
jejuni
.
Receiver Operating Characteristic Curve Analysis of Beach Water Quality Indicator Variables
Authors: Morrison Ann Michelle , Coughlin Kelly , Shine James P. , Coull Brent A. , Rex Andrea C.
Published: November 2003

Receiver operating characteristic (ROC) curve analysis is a simple and effective means to compare the accuracies of indicator variables of bacterial beach water quality. The indicator variables examined in this study were previous day's
Enterococcus
density and antecedent rainfall at 24, 48, and 96 h. Daily
Enterococcus
densities and 15-min rainfall values were collected during a 5-year (1996 to 2000) study of four Boston Harbor beaches. The indicator variables were assessed for their ability to correctly classify water as suitable or unsuitable for swimming at a maximum threshold
Enterococcus
density of 104 CFU/100 ml. Sensitivity and specificity values were determined for each unique previous day's
Enterococcus
density and antecedent rainfall volume and used to construct ROC curves. The area under the ROC curve was used to compare the accuracies of the indicator variables. Twenty-four-hour antecedent rainfall classified elevated
Enterococcus
densities more accurately than previous day's
Enterococcus
density (
P
= 0.079). An empirically derived threshold for 48-h antecedent rainfall, corresponding to a sensitivity of 0.75, was determined from the 1996 to 2000 data and evaluated to ascertain if the threshold would produce a 0.75 sensitivity with independent water quality data collected in 2001 from the same beaches.
Bioaccumulation of Copper Ions by
Escherichia coli
Expressing Vanabin Genes from the Vanadium-Rich Ascidian
Ascidia sydneiensis samea
Authors: Ueki Tatsuya , Sakamoto Yasuhisa , Yamaguchi Nobuo , Michibata Hitoshi
Published: November 2003

The genes encoding two vanadium-binding proteins, vanabin1 and vanabin2, from a vanadium-rich ascidian,
Ascidia sydneiensis samea
, were recently identified and cloned (T. Ueki, T. Adachi, S. Kawano, M. Aoshima, N. Yamaguchi, K. Kanamori, and H. Michibata, Biochim. Biophys. Acta 1626:43-50, 2003). The vanabins were found to bind vanadium(IV), and an excess of copper(II) ions inhibited the binding of vanadium(IV) to the vanabins in vitro. In this study, we constructed
Escherichia coli
strains that expressed vanabin1 or vanabin2 fused to maltose-binding protein (MBP) in the periplasmic space. We found that both strains accumulated about twenty times more copper(II) ions than the control BL21 strain, while no significant accumulation of vanadium was observed. The strains expressing either MBP-vanabin1 or MBP-vanabin2 absorbed approximately 70% of the copper ions in the medium to which 10 μM copper (II) ions were initially added. The MBP-vanabin1 and MBP-vanabin2 protein expressed in the periplasm bound to copper ions at a copper:protein molar ratio of 8:1 and 5:1, respectively, but MBP did not bind to copper ions. These data showed that the metal-binding proteins vanabin1 and vanabin2 bound copper ions directly and enhanced the bioaccumulation of copper ions by
E. coli
.
Effect of the Environment on Genotypic Diversity of
Actinomyces naeslundii
and
Streptococcus oralis
in the Oral Biofilm
Authors: Paddick James S. , Brailsford Susan R. , Kidd Edwina A. M. , Gilbert Steven C. , Clark Douglas T. , Alam Sharmin , Killick Zoe J. , Beighton David
Published: November 2003

The genotypic diversity of
Actinomyces naeslundii
genospecies 2 (424 isolates) and
Streptococcus oralis
(446 isolates) strains isolated from two sound approximal sites in all subjects who were either caries active (seven subjects) or caries free (seven subjects) was investigated by using the repetitive extragenic palindromic PCR. The plaque from the caries-active subjects harbored significantly greater proportions of mutans streptococci and lactobacilli and a smaller proportion of
A. naeslundii
organisms than the plaque sampled from the caries-free subjects. These data confirmed that the sites of the two groups of subjects were subjected to different environmental stresses, probably determined by the prevailing or fluctuating acidic pH values. We tested the hypothesis that the microfloras of the sites subjected to greater stresses (the plaque samples from the caries-active subjects) would exhibit reduced genotypic diversity since the sites would be less favorable. We found that the diversity of
A. naeslundii
strains did not change (χ2 = 0.68;
P
= 0.41) although the proportional representation of
A. naeslundii
was significantly reduced (
P
< 0.05). Conversely, the diversity of the
S. oralis
strains increased (χ2 = 11.71;
P
= 0.0006) and the proportional representation of
S. oralis
did not change. We propose that under these environmental conditions the diversity and number of niches within the oral biofilm that could be exploited by
S. oralis
increased, resulting in the increased genotypic diversity of this species. Apparently,
A. naeslundii
was not able to exploit the new niches since the prevailing conditions within the niches may have been deleterious and not supportive of its proliferation. These results suggest that environmental stress may modify a biofilm such that the diversity of the niches is increased and that these niches may be successfully exploited by some, but not necessarily all, members of the microbial community.
Fingerprinting Microbial Assemblages from the Oxic/Anoxic Chemocline of the Black Sea
Authors: Vetriani Costantino , Tran Hiep V. , Kerkhof Lee J.
Published: November 2003

Biomass samples from the Black Sea collected in 1988 were analyzed for SSU genes from
Bacteria
and
Archaea
after 10 years of storage at −80°C. Both clonal libraries and direct fingerprinting by terminal restriction fragment length polymorphism (T-RFLP) analyses were used to assess the microbial community. Uniform and discrete depth distributions of different SSU phylotypes were observed. However, most recombinant clones were not restricted to a specific depth in the water column, and many of the major T-RFLP peaks remain uncharacterized. Of the clones obtained, an ε-
Proteobacteria
and a
Pseudoalteromonas
-like clone accounted for major peaks in the fingerprint, while deeply branching lineages of α- and γ-
Proteobacteria
were associated with smaller peaks. Additionally, members were found among both the δ-
Proteobacteria
related to sulfate reducers and the
Archaea
related to phylotypes from the ANME groups that anaerobically oxidize methane.
Evaluation of F+ RNA and DNA Coliphages as Source-Specific Indicators of Fecal Contamination in Surface Waters
Authors: Cole Dana , Long Sharon C. , Sobsey Mark D.
Published: November 2003

Male-specific (F+) coliphages have been investigated as viral indicators of fecal contamination that may provide source-specific information for impacted environmental waters. This study examined the presence and proportions of the different subgroups of F+ coliphages in a variety of fecal wastes and surface waters with well-defined potential waste impacts. Municipal wastewater samples had high proportions of F+ DNA and group II and III F+ RNA coliphages. Bovine wastewaters also contained a high proportion of F+ DNA coliphages, but group I and IV F+ RNA coliphages predominated. Swine wastewaters contained approximately equal proportions of F+ DNA and RNA coliphages, and group I and III F+ RNA coliphages were most common. Waterfowl (gull and goose) feces contained almost exclusively F+ RNA coliphages of groups I and IV. No F+ coliphages were isolated from the feces of the other species examined. F+ coliphage recovery from surface waters was influenced by precipitation events and animal or human land use. There were no significant differences in coliphage density among land use categories. Significant seasonal variation was observed in the proportions of F+ DNA and RNA coliphages. Group I F+ RNA coliphages were the vast majority (90%) of those recovered from surface waters. The percentage of group I F+ RNA coliphages detected was greatest at background sites, and the percentage of group II F+ RNA coliphages was highest at human-impacted sites. Monitoring of F+ coliphage groups can indicate the presence and major sources of microbial inputs to surface waters, but environmental effects on the relative occurrence of different groups need to be considered.
Oriented Adhesion of
Escherichia coli
to Polystyrene Particles
Authors: Jones Joseph F. , Feick Jason D. , Imoudu Daniel , Chukwumah Nkiru , Vigeant Margot , Velegol Darrell
Published: November 2003

The adhesion of nonflagellated
Escherichia coli
strain K-12 to polystyrene (PS) latex spheres or glass capillaries has been observed by using several techniques. Attention was focused on the orientation of the rod-shaped bacteria as they adhered to the surfaces in 100 mM phosphate-buffered saline. Data show that PS particles adhered to the ends of the bacteria more than 90% of the time. Moreover, the PS particles adhered to one end only, never to both. Similarly, for experiments with bacteria adhering to glass, the bacteria adhered on their ends. In order to determine whether the end of a bacterium had a different charge density from that of the middle, rotational electrophoresis experiments were used. These experiments indicated no measurable charge nonuniformity. In order to examine how strongly adhered the bacteria were to the PS particles, differential electrophoresis was used. Almost always, bacteria were found to be irreversibly adhered to the PS spheres. The cause of the oriented adhesion is not likely due to surface lipopolysaccharides (LPS), since the three strains of K-12 that were used, each having a different length of LPS, showed similar behavior. The results are discussed in terms of bacterial cell polarity. The data indicate that nanodomains on the bacterial ends are important for adhesion and that the time scale for irreversible adhesion is short.
Gene Dosage Effect of
l
-Proline Biosynthetic Enzymes on
l
-Proline Accumulation and Freeze Tolerance in
Saccharomyces cerevisiae
Authors: Terao Yukiyasu , Nakamori Shigeru , Takagi Hiroshi
Published: November 2003

We have previously reported that
l
-proline has cryoprotective activity in
Saccharomyces cerevisiae
. A freeze-tolerant mutant with
l
-proline accumulation was recently shown to carry an allele of the
PRO1
gene encoding γ-glutamyl kinase, which resulted in a single amino acid substitution (Asp154Asn). Interestingly, this mutation enhanced the activities of γ-glutamyl kinase and γ-glutamyl phosphate reductase, both of which catalyze the first two steps of
l
-proline synthesis and which together may form a complex in vivo. Here, we found that the Asp154Asn mutant γ-glutamyl kinase was more thermostable than the wild-type enzyme, which suggests that this mutation elevated the apparent activities of two enzymes through a stabilization of the complex. We next examined the gene dosage effect of three
l
-proline biosynthetic enzymes, including Δ
1
-pyrroline-5-carboxylate reductase, which converts Δ
1
-pyrroline-5-carboxylate into
l
-proline, on
l
-proline accumulation and freeze tolerance in a non-
l
-proline-utilizing strain. Overexpression of the wild-type enzymes has no influence on
l
-proline accumulation, which suggests that the complex is very unstable in nature. However, co-overexpression of the mutant γ-glutamyl kinase and the wild-type γ-glutamyl phosphate reductase was effective for
l
-proline accumulation, probably due to a stabilization of the complex. These results indicate that both enzymes, not Δ
1
-pyrroline-5-carboxylate reductase, are rate-limiting enzymes in yeast cells. A high tolerance for freezing clearly correlated with higher levels of
l
-proline in yeast cells. Our findings also suggest that, in addition to its cryoprotective activity, intracellular
l
-proline could protect yeast cells from damage by oxidative stress. The approach described here provides a valuable method for breeding novel yeast strains that are tolerant of both freezing and oxidative stresses.
Reverse Transcription-PCR Analysis of Bottled and Natural Mineral Waters for the Presence of Noroviruses
Authors: Lamothe Gilbert Thierry , Putallaz Thierry , Joosten Han , Marugg Joey D.
Published: November 2003

A seminested reverse transcription-PCR method coupled to membrane filtration was optimized to investigate the presence of norovirus (NV) RNA sequences in bottled and natural mineral waters. The recovery of viral particles by filtration varied between 28 and 45%, while the limit of detection of the overall method ranged from 6 to 95 viral particles. The assay was broadly reactive, as shown by the successful detection of 27 different viral strains representing 12 common genotypes of NVs. A total of 718 bottled and natural mineral water samples were investigated, including 640 samples of finished, spring, and line products (mostly 1 to 1.5 liters), collected from 36 different water brands of various types and from diverse geographic origins over a 2-year period. In addition, 78 samples of larger volume (10 and 400 to 500 liters) and environmental swabs were investigated. From the 1,436 analyses that were performed for the detection of NVs belonging to genogroups I and II, 34 samples (2.44%) were presumptively positive by seminested RT-PCR. However, confirmation by DNA sequence analysis revealed that all presumptive positive results were either due to nonspecific amplification or to cross-contamination. In conclusion, these results do not provide any evidence for the presence of NV genome sequences in bottled waters.