bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploratory data analysis reveals visuovisual interhemispheric transfer in functional magnetic resonance imaging
Authors: D'Arcy Ryan C. N. , Hamilton Andrew , Jarmasz Mark , Sullivan Sara , Stroink Gerhard
Published: February 2006

We used an exploratory data analysis approach to detect interhemispheric processing of complex visual stimuli in functional magnetic resonance imaging (fMRI). A crossed–uncrossed visual field paradigm was used to elicit interhemispheric transfer of picture/word information. Under the uncrossed (control) condition, the stimuli were presented to the preferential hemispheres (pictures to the left visual field/right hemisphere and words to the right visual field/left hemisphere). Under the crossed condition, the visual field presentation was switched in order to elicit increased interhemispheric processing. Fuzzy cluster analysis revealed significantly more crossed activity in cortical areas near the splenium of the corpus callosum. As expected, examination of the activation revealed smaller responses in perisplenial regions (relative to visual responses in the medial extrastriate regions). The exploratory results were compared with those obtained from parametric and masked analyses. The findings confirm that fMRI can be used to detect interhemispheric transfer of picture/word information. The activation was optimally characterized using exploratory data analysis. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Assessment of fraction of radiobiologically hypoxic cells in human melanoma xenografts by dynamic contrast‐enhanced MRI
Authors: Egeland Tormod A. M. , Gaustad Jon‐Vidar , Vestvik Ida K. , Benjaminsen Ilana C. , Mathiesen Berit , Rofstad Einar K.
Published: February 2006

A noninvasive method for assessment of the extent of hypoxia in experimental and human tumors is highly needed. In this study, the potential usefulness of dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) was investigated, using gadopentetate dimeglumine (Gd‐DTPA) as contrast agent and A‐07 human melanoma xenografts as tumor model. DCE‐MRI was performed at a voxel size of 0.3 × 0.6 × 2.0 mm3 with spoiled gradient‐recalled sequences. Images of E · F (E is the initial extraction fraction of Gd‐DTPA and F is perfusion) and λ (the partition coefficient of Gd‐DTPA, which is proportional to extracellular volume fraction) were obtained by Kety analysis of DCE‐MRI data. The study was based on the hypothesis that hypoxic tissue would have low E · F (i.e., poor oxygen supply) and/or low λ (i.e., high cell density and, hence, high oxygen consumption rate). Twenty‐two tumors were first subjected to DCE‐MRI and then to measurement of fraction of hypoxic cells, using a radiobiological assay. E · F was found to be strongly correlated to fraction of hypoxic cells (P < 0.000001), whereas significant correlation between λ and fraction of hypoxic cells could not be detected. It is thus possible that E · F may be a useful parameter for the extent of hypoxia in experimental and human tumors with physiologic properties similar to those of A‐07 tumors. This possibility warrants further studies involving experimental tumors of several lines, as well as human tumors. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Electrophysiological subtypes and prognosis of childhood Guillain–Barré syndrome in Japan
Authors: Nagasawa Kasumi , Kuwabara Satoshi , Misawa Sonoko , Fujii Katsunori , Tanabe Yuzo , Yuki Nobuhiro , Hattori Takamichi , Kohno Yoichi
Published: February 2006

Guillain–Barré syndrome (GBS) is classified into acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN), but little is known about the incidence of the subtypes and the prognosis of childhood GBS. To elucidate the features and long‐term prognosis, clinical and electrophysiological data for 31 Japanese GBS children were reviewed. By electrodiagnostic criteria, children were classified as having AIDP (35%) or AMAN (48%), or were unclassified (16%). The AMAN children invariably had normal sensory nerve potentials. Between the two groups, age, sex, and clinical disability did not differ significantly, but the AIDP children more frequently had cranial and sensory nerve involvement, and the AMAN children more frequently had preceding gastroenteritis. By 6 months after onset, all the AIDP and 80% of the AMAN children had regained the ability to walk; by 2 years, all but one of the AMAN children could walk. In Japanese childhood GBS, the proportion of AIDP and AMAN appears to be similar. Recovery is generally favorable in both subtypes, but some of the AMAN children experienced delayed recovery. Muscle Nerve, 2006
Effects of fiber compression and length distribution on the flexural properties of short kenaf fiber‐reinforced biodegradable composites
Authors: Shibata Shinichi , Fukumoto Isao , Cao Yong
Published: February 2006

The effects of the fiber compression and the length distribution on the flexural properties of short kenaf fiber‐reinforced biodegradable composites were investigated. Two types of kenaf (KU and KT) that were different in the density and the length distribution were used as reinforcements. These fibers were mixed with a corn–starch‐based resin, and the composite specimens were fabricated by a hot press forming. The flexural modulus in the KU specimens was not different from that in the KT, despite the difference of the fiber Young's modulus (KU 14.5 GPa and KT 22.1 GPa). This was because the KU was compressed more than the KT in the composite specimen because of the lower density structure. However, in the longest fiber (10.5 mm), the flexural strength in the KT specimens was considerably higher by 67% than that in the KU. The reason was that the KT did not include the fibers below the critical length (4.2 mm) because of the narrower fiber distribution than the KU. In fact, the flexural strength in the KT specimen significantly decreased with decrease in the average fiber length, which included the fibers below the critical length. Moreover, the flexural modulus agreed well with the calculated values by Cox's model that incorporated the effect of the fiber compression. POLYM. COMPOS. 27:170–176, 2006. © 2006 Society of Plastics Engineers
Accuracy of sequence alignment and fold assessment using reduced amino acid alphabets
Authors: Melo Francisco , Marti‐Renom Marc A.
Published: February 2006

Reduced or simplified amino acid alphabets group the 20 naturally occurring amino acids into a smaller number of representative protein residues. To date, several reduced amino acid alphabets have been proposed, which have been derived and optimized by a variety of methods. The resulting reduced amino acid alphabets have been applied to pattern recognition, generation of consensus sequences from multiple alignments, protein folding, and protein structure prediction. In this work, amino acid substitution matrices and statistical potentials were derived based on several reduced amino acid alphabets and their performance assessed in a large benchmark for the tasks of sequence alignment and fold assessment of protein structure models, using as a reference frame the standard alphabet of 20 amino acids. The results showed that a large reduction in the total number of residue types does not necessarily translate into a significant loss of discriminative power for sequence alignment and fold assessment. Therefore, some definitions of a few residue types are able to encode most of the relevant sequence/structure information that is present in the 20 standard amino acids. Based on these results, we suggest that the use of reduced amino acid alphabets may allow to increasing the accuracy of current substitution matrices and statistical potentials for the prediction of protein structure of remote homologs. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Dynamics of pesticide residues in the autumn Chinese cabbage (Brassica chinensis L.) grown in open fields
Authors: Zhang Zhi‐Yong , Zhang Cun‐Zheng , Liu Xian‐Jin , Hong Xiao‐Yue
Published: February 2006

Residues of the pesticides chlorpyrifos, dimethoate, cyhalothrin, cypermethrin, fenvalerate, deltamethrin and chlorothalonil in the autumn Chinese cabbage (Brassica chinensis L.) were studied using gas chromatography. The results indicated that the residues were dependent on the frequency and rate of pesticide application and on the weather conditions immediately following spraying. When the Chinese cabbages were treated once at normal rates, the half‐lives of the seven pesticides in the vegetable were 4.7, 5.3, 2.9, 3.5, 5.4, 4.3 and 4.0 days respectively. Thus, based on the recommended preharvest intervals, the residual levels of all pesticides were within the national standards. When the Chinese cabbages were treated four times at maximal rates at 5 day intervals, the half‐lives of chlorpyrifos, cypermethrin and chlorothalonil in the vegetable were 3.6, 2.9 and 5.9 days respectively, so that, based on the recommended preharvest intervals, the residual levels of chlorpyrifos and chlorothalonil exceeded the national standards for pollution‐free vegetables, but the residual level of cypermethrin was within the national standard. Effects of rain on pesticide final residues in plants treated four times were more significant than in those treated once. Copyright © 2006 Society of Chemical Industry
Ultra‐low flow nanospray for the normalization of conventional liquid chromatography/mass spectrometry through equimolar response: standard‐free quantitative estimation of metabolite levels in drug discovery
Authors: Valaskovic Gary A. , Utley Lucas , Lee Mike S. , Wu Jing‐Tao
Published: February 2006

Nanospray experiments were performed on an ensemble of drug molecules and their commonly known metabolites to compare performance with conventional electrospray ionization (ESI) and to evaluate equimolar response capabilities. Codeine, dextromethorphan, tolbutamide, phenobarbital, cocaine, and morphine were analyzed along with their well‐known metabolites that were formed via hydroxylation, dealkylation, hydrolysis, and glucuronidation. Nanospray exhibited a distinct trend toward equimolar response when flow rate was reduced from 25 nL/min to less than 10 nL/min. A more uniform response between the parent drug and the corresponding metabolites was obtained at flow rates of 10 nL/min or lower. The largest discrepancy was within ±50% for plasma samples. Nanospray was used as a calibrator for conventional ESI liquid chromatography/tandem mass spectrometry (LC/MS/MS) and normalization factors were applied to the quantitation of an acyl‐glucuronide metabolite of a proprietary compound in rat plasma. A nanospray calibration method was developed with the standard curve of the parent drug to generate quantitative results for drug metabolites within ±20% of that obtained with reference standards and conventional ESI. The nanospray method provides a practical solution for the quantitative estimation of drug metabolites in drug discovery when reference standards are not available. Copyright © 2006 John Wiley & Sons, Ltd.
Reactive Gas Pressure Syntheses of Nitride‐Diazenides and Hydridometalates
Authors: Auffermann Gudrun , Kniep Rüdiger , Bronger Welf
Published: February 2006

Nitride‐diazenides and hydridometalates (exemplified by the chemical systems Sr (Ba)‐N2 and Rb‐Pt‐H2) are obtained by reactive gas pressure syntheses in autoclaves starting from the elements and binary precursors, respectively. The formation of the nitride‐diazenides can be described in terms of reversible redox‐intercalation processes and that of the hydridometalates as reversible solid‐gas redox reactions. Phase formation and stability regions of the intermediate compounds of the chemical systems under consideration are particularly controlled by the level of the applied gas pressure.
Zu Grundfragen Anorganischer Festkörperchemie: Sind NaFeF3 [1] und CsFeF3 [2] ‚Perowskite’︁?
Authors: Hoppe Rudolf
Published: February 2006

On fundametal Questions of Inorganic Solid State Chemistry: Are NaFeF3 [1] and CsFeF3 [2] ‘Perovskites’?

Even with simple molecules like C6H6 or C6H5CH3 ‘gross formulas’ like CH or C7H8 are nonsense. In the case of inorganic solids such procedures are even worse. For example by writing ‘K2Si4O9’ no hint is given concerning the specific characteristics of the structure. ‘CsFeF3’ hides the true composition, which in fact corresponds to 1Cs2iCs21iFe22Fe1iF32iF6. Therefore, it is essential that the correct formulas have to be added, which are based on point groups (PGr) of particles with exactly the same magnitude of infinitude of the partial lattice (PL). In addition, the connectivity of the PL must be indicated, e.g. [PtCl6]K2 or K2[Cl6Pt] instead of K2[PtCl6]. Therefore, the values of d(X‐M), C.P.(X/M), nECoN(X/M) (with n = 0, 1, n) of the anions have to be added to those of the cations M in the description of crystal structures. The ‘emancipation’ of the anions is urgent, since in most cases their connectivity reigns the utmost important structural features! Sometimes ‘on‐line‐formulas’ could be used indicating steric arrangements as shown here.
Synthesis and Crystal Structure of Two Lanthanide Complexes with Benzenecarboxylic Derivatives
Authors: Zhang Zheng‐Hua , Wan Shuang‐Yi , Okamura Taka‐aki , Sun Wei‐Yin , Ueyama Norikazu
Published: February 2006

Two novel lanthanide coordination polymers, [La(tpaa)3(H2O)2] (1) and [Eu2(BDC)3(DMF)2(H2O)2] (2) (Htpaa = terephthalamic acid, H2BDC = 1,4‐benzenedicarboxylic acid, DMF = N,N‐dimethylformamide), were hydro(solvo)thermally synthesized by reactions of the corresponding lanthanide nitrate salts with 1,3,5‐triazine‐2,4,6‐tri(4‐benzenecarboxylate) (L), in which a simultaneous hydrolysis of the ligand L occurred. Single‐crystal X‐ray analysis revealed that complex 1 comprises one‐dimensional chains that are further interlinked via hydrogen bonds, resulting in a two‐dimensional network; while complex 2 is a three‐dimensional interpenetrated coordination architecture.
Computational Magnetochemistry: Complementary Quantum Mechanical Tools
Authors: Eifert Thomas , Handrick Klaus , Hüning Felix , Neuhausen Ulrich , Schilder Helmut , Lueken Heiko
Published: February 2006

Magnetic behaviour of condensed magnetic d and f systems with localised ‘magnetic electrons’ is essentially controlled by both single ion effects (interelectronic and spin‐orbit coupling, ligand field potential) and interionic exchange interactions. The latter act according to the spin dimensionality forced upon the magnetic centre via the single ion effects. For a complete understanding of magnetic behaviour on the basis of quantum mechanical models a two‐step procedure presents itself that determines in a complementary way first the ‘easy’ direction of the centres' magnetic dipoles connected with the single ion ground state. Subsequently, the relevant isotropic/anisotropic spin‐spin coupling model is applied (Heisenberg, XY, Ising). With the help of the textbook compounds CrBr3 and Cs3 CoCl5 as well as β‐RuCl3 the way of acting is pointed out.
Multivalent Complex Salts of Copper: Synthesis and X‐Ray Structural Analysis of [CuII(en)3][CuI4{(NNNPh)2C6H4}3] (en = ethylendiamine), an anionic Tris‐1,3‐bis(phenyltriazenide)benzene Complex of Tetrakis‐Copper(I)
Authors: Hörner Manfredo , Manzoni de Oliveira Gelson , Bortoluzzi Adailton João
Published: February 2006

An ethanolic solution of CuCl / ethylendiamine reacts with 1.3‐bis‐ (phenyltriazene)benzene in THF leading to the deprotonation of the bis triazene ligand to give orange crystals of [CuII(en)3][CuI4{(NNN‐Ph)2C6H4}3], an example of a rare complex salt of copper with mixed valence states. In the anion complex [CuI4{(NNNPh)2C6H4}3]2− the copper(I) ions are disposed linearly as single, bridged pairs in the two extremes of an axis, each of them presenting a trigonal bipyramidal alike coordination arrangement.
Kristallstruktur von Natrium‐Dihydrogencyamelurat‐Tetrahydrat Na[H2(C6N7)O3] · 4 H2O
Authors: Sattler Andreas , Schnick Wolfgang
Published: February 2006

Crystal Structure of Sodium Dihydrogencyamelurate Tetrahydrate Na[H2(C6N7)O3] · 4 H2O

Sodium dihydrogencyamelurate‐tetrahydrate Na[H2(C6N7)O3]·4 H2O was obtained by neutralisation of an aqueous solution, previously prepared by hydrolysis of the polymer melon with sodium hydroxide. The crystal structure was solved by single‐crystal X‐ray diffraction ($P{\bar 1}$ a = 6.6345(13), b = 8.7107(17), c = 11.632(2) Å, α = 68.96(3), β = 87.57(3), γ = 68.24(3)°, V = 579.5(2) Å3, Z = 2, R1 = 0.0535, 2095 observed reflections, 230 parameters). Both hydrogen atoms of the dihydrogencyamelurate anion are directly bound to nitrogen atoms of the cyameluric nucleus, thus proving the preference of the keto‐tautomere in salts of cyameluric acid in the solid‐state. The compound forms a layer‐like structure with an extensive hydrogen bonding network.
Oxidative C‐C Coupling of Dilithium (2‐Pyridylmethanidyl)(tert‐butyldimethylsilyl)amide with White Phosphorus
Authors: Westerhausen Matthias , Kneifel Alexander N. , Mayer Peter
Published: February 2006

(2‐Pyridylmethyl)(tert‐butyldimethylsilyl)amine (1) can be lithiated once or twice yielding lithium (2‐pyridylmethyl)(tert‐butyldimethylsilyl)amide (2) and dilithium (2‐pyridylmethanidyl)(tert‐butyldimethylsilyl)amide (3), respectively. The oxidation of 3 with white phosphorus yields dilithium 1,2‐dipyridyl‐1,2‐bis(tert‐butyldimethylsilylamido)ethane (4) which crystallizes after partial hydrolysis as an adduct of the form 2 · 4.
Knowledge, Wisdom, and the Philosopher
Authors: Kaufman Daniel A.
Published: February 2006

The overarching thesis of this essay is that despite the etymological relationship between the word ‘philosophy’ and wisdom—the word ‘philosophos’, in Greek, means ‘lover of wisdom’—and irrespective of the longstanding tradition of identifying philosophers with ‘wise men’—mainline philosophy, historically, has had little interest in wisdom and has been preoccupied primarily with knowledge. Philosophy, if we are speaking of the mainline tradition, has had and continues to have more in common with the natural and social sciences than it does with the humanities and liberal arts.

In advancing this thesis, I divide the history of philosophy into three competing traditions: the mainline tradition of philosophy and two philosophical ‘countercultures,’ one conservative the other radical. At issue between these rival traditions is precisely the relative significance of knowledge and wisdom and their respective places in inquiry. I also provide an account of the distinction between knowledge and wisdom—which I argue is greater than has perhaps been appreciated—and between the natural and applied sciences, on the one hand, and the humanities and liberal arts on the other.
Beliefs, Desires and Moral Realism
Authors: Goldstick Daniel
Published: February 2006

An argument against the claim that moral realism cannot be sustained because moral beliefs, being affective-conative states, cannot themselves be true or false. In fact moral claims can fail both in terms of a failure of the standard it expresses to be realised by a given agent and also in terms of whatever it commends to be good or bad, right or wrong, in actual fact.
Positive ageing: the views of middle-aged and older adults in Hong Kong
Authors: CHONG ALICE MING-LIN , NG SIK-HUNG , WOO JEAN , KWAN ALEX YUI-HUEN
Published: February 2006

Life expectancy has been increasing rapidly in many parts of the world, including Hong Kong. A longer life can be welcome as an opportunity to fulfil as yet unmet aspirations, or to take up new challenges and projects, but it may also be a burden, especially for individuals who are unprepared. A pressing question for longer-life societies is: how may older people live their longer lives to the full positively? This article reports a qualitative study of Hong Kong Chinese people's views about ‘positive ageing’, as expressed and discussed in 15 focus groups of middle-aged and older people. Two themes emerged: first, the participants considered that positive ageing should comprise good health, having a positive life attitude, active engagement with an activity or with society, feeling supported by their families and friends, being financially secure, and living in a place with emotional ties; and secondly, several key factors that enable positive ageing were identified, namely, adopting a healthy lifestyle, thinking positively, promoting family and inter-personal relationships, and building up financial resources. The views of the participants about ‘positive ageing’ are compared with those reported from western studies, and the policy implications are considered.
25th volume celebration paper
Policies for the aged in the 21st century: more ‘structured dependency’ or the realisation of human rights?
Authors: TOWNSEND PETER
Published: February 2006

By the late 20th century, the plight of millions of older people in many developed countries was regarded as serious and was acknowledged to require concerted cross-national remedial action. Sociologists and social gerontologists only then were beginning to put together explanations rooted in the evolution of social policy and its corresponding institutions. One thesis that attracted support was that the dependency of the aged had been ‘structured’ by long-term economic and social policies. During the final decades of the 20th century, older people were perceived and treated, according to accumulating research evidence, as more dependent than they really were or needed to be. This had been fostered by the emerging institutions of retirement, income maintenance, and residential and domiciliary care. This development had been the responsibility primarily of the State, which tried to deliver welfare but also to accommodate the market. Forms of discrimination against older people had become, or continued to be, as deep as forms of discrimination against women and ethnic minorities. Such ‘institutionalised ageism’ had to be countered. Hopes were invested in anti-discriminatory policies that reflected good reciprocal relationships between the generations in many families and the rights of individuals of any age to human dignity and opportunities to practise their skills. The globalisation of the market and affiliation to neo-liberal policies, together with the simultaneous passage of various instruments of human rights, have changed the nature of the problem, and therefore the debate, during the early 21st century. This paper argues that the release and implementation during and after the Second World War of collective liberal egalitarian values, expressed in many countries in international statements on human rights, as will be shown, had a big impact on the design of public services, including those for older people. If the claims for the elderly in the welfare states of 50 years ago were exaggerated, as we can now safely conclude, the claims for older people today are even more exaggerated – at a time of heightened emphasis on individual rights and individual market powers. The various problems of ‘structured’ dependency persist, and seem set to grow in many parts of the world. Human rights offer a framework of rigorous analysis and anti-discriminatory work. Success depends on good operational measurement, and the incorporation of international and national institutions and policies that reflect those rights.
Health, security and foreign policy
Authors: McINNES COLIN , LEE KELLEY
Published: February 2006

Over the past decade, health has become an increasingly important international issue and one which has engaged the attention of the foreign and security policy community. This article examines the emerging relationship between foreign and security policy, and global public health. It argues that the agenda has been dominated by two issues – the spread of selected infectious diseases (including HIV/AIDS) and bio-terror. It argues that this is a narrow framing of the agenda which could be broadened to include a wider range of issues. We offer two examples: health and internal instability, including the role of health in failing states and in post-conflict reconstruction; and illicit activities. We also argue that the relationship between global public health, and foreign and security policy has prioritised the concerns of the latter over the former – how selected health issues may create risks for (inter)national security or economic growth. Moreover the interests of the West are prominent on this agenda, focusing (largely though not exclusively) on how health risks in the developing world might impact upon the West. It is less concerned with the promotion of global public health.
Digital diasporas and conflict prevention: the case of Somalinet.com
Authors: BRINKERHOFF JENNIFER M.
Published: February 2006

Recent research on the Internet and terrorism confirms the Internet’s enabling features for terrorist activities, including its ease of access, anonymity, and international character. While the Internet can serve as a tool for nefarious purposes, little research has focused on whether and how the Internet can be used to prevent conflict and, ultimately, terrorist activities. This research focuses on one group that might be considered a resource base for violent action: diasporas from failed states. Research shows a strong correlation between marginalisation and violence. On the other hand, fostering a shared identity, inclusive of liberal values, and promoting carefully framed discussion and debate may reduce psychological incentives to engage in violent activities. This article examines the case of one digital diaspora – a diaspora organised on the Internet – to explore these hypotheses. Specifically, the case of Somalinet suggests potential for the Internet to promote liberal values, channel frustration into verbal debates thus diffusing tension, and create communities that counter the marginalisation conducive to violence.
Threats all the way down: US strategic initiatives in a unipolar world
Authors: HUNTLEY WADE L.
Published: February 2006

This essay critically assesses the Bush Administration’s strategic and nuclear weapons policy initiatives in historical context. The assessment first delineates the genuinely original elements of the 2002 Nuclear Posture Review. The analysis then considers the potential impact of tactical nuclear weapons planning on prospects for deterring WMD attacks by both ‘rogue’ states and non-state (terrorist) groups, and explores how this planning risks creating ‘commitment traps’ increasing pressures to follow through on nuclear threats. The essay concludes that Bush Administration strategic policy initiatives are less explicable by ‘realist’ criteria than by a more ‘idealist’ strategy premising a militantly active US global role.
Cultural foundations of military diffusion
Authors: GOLDMAN EMILY O.
Published: February 2006

This article examines cross-national variation in the diffusion and adoption of military technologies and ideas. The history of warfare has been marked by periods of innovation in which the institutions and practices of war-making adapted in response to technological opportunities, and social and political developments. As information about new practices spreads, through the demonstration effects of innovating states or transnational social networks, military innovations have diffused throughout the international system. Diffusion can restructure power relations as states leverage new capabilities to increase their military power and enhance their international influence.
Deep‐water mass source and dynamic associated with rapid climatic variations during the last glacial stage in the North Atlantic: A multiproxy investigation of the detrital fraction of deep‐sea sediments
Authors: Ballini M. , Kissel C. , Colin C. , Richter T.
Published: February 2006

In order to investigate North Atlantic Deep Water (NADW) dynamics and variability during the last glacial stage, a very high resolution multiproxy analysis of the detrital fraction of sediments deposited during Heinrich event 4 and Dansgaard‐Oeschger cycles 8 and 7 has been conducted on three deep‐sea cores. These cores are distributed along the path of the North Atlantic Deep Water from the Faeroe Shetland Channel to the Reykjanes ridge and the Irminger basin. The concentration in fine‐grained magnetites, the Ti‐content, and the smectite percentage within the clay minerals show similar and coeval fluctuations at each site and are comparable from one site to the other. This is the imprint of the detrital fraction originating from the northern basaltic provinces and transported to the studied sites. The average grain size in the fine fraction indicates a transport by deep‐sea currents. Therefore the observed fluctuations illustrate changes in the vigor of the bottom currents associated with the NADW with weak currents during cold periods (Heinrich 4 and stadials) and reactivation of the bottom circulation during interstadials.
Weather in mesospheric ice layers
Authors: Berger U. , Lübken F.‐J.
Published: February 2006

Layers in the summer mesosphere are studied using an ice model which applies background conditions from a new model called LIMA (Leibniz Institute Middle Atmosphere Model). LIMA covers the height range 0–150 km with high resolution. At low altitudes LIMA assimilates ECMWF ERA 40 data which introduces variability in the upper atmosphere. LIMA adequately represents the conditions in the mesosphere/lower thermosphere. Ice formation is interactively coupled to background water vapour which leads to ‘freeze drying’. Model ice layers vary in time and space and occasionally appear at mid latitudes. The geographical distribution of ice clouds generally agrees with observations. For example, the mean noctilucent cloud height at 69°N is 83.8 km (observations: 83.3 km). The occurrence rates of (polar) mesosphere summer echoes from the model also agree with measurements. At high latitudes ice layers sometimes disappear (‘ice holes’). From time to time wind fluctuations redistribute water vapor but in general freeze drying overwhelms.
High‐pressure elasticity of calcium oxide: A comparison between Brillouin spectroscopy and radial X‐ray diffraction
Authors: Speziale Sergio , Shieh Sean R. , Duffy Thomas S.
Published: February 2006

Single‐crystal Brillouin scattering to 25.2 GPa and powder X‐ray diffraction to 65.2 GPa in a radial geometry were carried out on CaO (lime) at ambient temperature in a diamond cell. From Brillouin scattering measurements the isentropic elastic constants of CaO at ambient conditions are C11 = 219.4 (7), C12 = 58.1 (7), C44 = 80.0 (2) GPa, where the numbers in parentheses are 1σ uncertainties on the last digit. The pressure derivatives of the compressional and off‐diagonal constants at ambient pressure are ∂C11/∂P = 9.9 (1), ∂C12/∂P = 2.2 (1), respectively. The pressure derivative of the shear constant is ∂C44/∂P = 0.25 (3), and it becomes negative at pressures above 5.9 GPa. Aggregate bulk and shear moduli are KS0 = 112.0 (2) and G0 = 80.05 (9) GPa, and their pressure derivatives are 4.72 (6) and 1.69 (5), respectively. The radial X‐ray diffraction data allow us to estimate the yield strength and the elastic constants of CaO using a phenomenological lattice strain model. The calculated strength of CaO increases from 0.3 to 1.9 GPa in the pressure range between 5.6 and 57.8 GPa. The estimated elastic constants are in good agreement with the extrapolation of the Brillouin data up to 36.6 GPa. At higher pressures, C11 appears softer and C12 appears stiffer than the extrapolation of Brillouin results. The value of C44 from radial diffraction is in agreement with the Brillouin data through the entire experimental pressure range. The discrepancies between Brillouin and radial diffraction data for C11 and C12 can be reconciled if α, the parameter which describes degree of stress/strain continuity across the sample's grains boundary, is allowed to vary from 1 at 36.6 GPa to 0.82 at 65.2 GPa. The “hydrostatic” cell volumes determined by applying lattice strain theory were fitted to the third‐order Birch‐Murnaghan equation. The fitted bulk modulus and its pressure derivative are KT0 = 110 (5) GPa and (∂KT/∂P)T0 = 4.5 (4), consistent with the Brillouin results, although possible softening of the equation of state at high pressure has been identified. The general agreement between the results of the two methods indicates that radial diffraction with lattice strain theory is a valid probe of the mechanical properties of a moderately soft cubic solid as CaO at ultrahigh pressures. However, more tests are required to quantify the effect of plasticity and texturing on the results of this method.
Long‐term evaluation of the Hydro‐Thermodynamic Soil‐Vegetation Scheme's frozen ground/permafrost component using observations at Barrow, Alaska
Authors: Mölders Nicole , Romanovsky Vladimir E.
Published: February 2006

The multi‐layer frozen ground/permafrost component of the hydro‐thermodynamic soil‐vegetation scheme (HTSVS) was evaluated by means of permafrost observations at Barrow, Alaska. HTSVS was driven by pressure, wind, air temperature, specific humidity, snow‐depth, rain, downward shortwave and long‐wave radiation observations for 14 consecutive years. Observed soil temperature data are available at various times during this period. HTSVS predicts soil temperatures that are slightly too low with root mean square errors (RMSEs) of, on average, less than 3.2 K. Sensitivity studies suggest that the treatment of snow and vegetation cover may be reasons for the inaccuracy. HTSVS' original thermal conductivity parameterization provides thermal conductivity values that are too high compared to typical observations. Introducing a parameterization frequently used in the permafrost research community, which was modified for application in numerical weather prediction (NWP) and climate models and model consistency in HTSVS, improves soil temperature predictions and reduces RMSEs in some layers by up to 1 K, and on average by 0.2 K. Assuming five to ten layers for the first 2 or 3 m as is usually done in NWP and climate modeling is insufficient to capture the active layer depth, because the number and position of the grid nodes play a role. The depth of the lower boundary of the soil model and the boundary condition affect the overall performance. Consequently, under current computational possibilities, simulating permafrost and the active layer in atmospheric models requires a compromise between the degree of accuracy and affordable computational time.
External electron ionization 7T Fourier transform ion cyclotron resonance mass spectrometer for resolution and identification of volatile organic mixtures
Authors: Fu Jinmei , Purcell Jeremiah M , Quinn John P. , Schaub Tanner M. , Hendrickson Christopher L. , Rodgers Ryan P. , Marshall Alan G.
Published: February 2006

An external electron ionization (EI) source has been interfaced to a 7T Fourier transform ion cyclotron resonance mass spectrometer and tested for volatile complex mixture analysis. A new Sulfinert®-deactivated inlet system provides continuous stable sample flow to the EI source, leading to stable ion signal (±10% deviation) for 2h from a 200nL mixture of 15 n-alkylbenzenes. Ultrahigh-mass resolving power, m∕Δm50%≈735000, was obtained for 1-bromo-2-chlorobenzene with accurate isotopic ratio measurement. Base line resolution was observed for two of the closest commonly encountered mass doublets, C3∕SH4 (m2−m1=3.4mDa at m∕z=190) and SH3C13∕C4 (m2−m1=1.1mDa at m∕z=190). Although hydrocarbons dominate the positive-ion 18eV EI Fourier transform ion cyclotron resonance mass spectrum from diesel fuels, many sulfur-, nitrogen-, and oxygen-containing compounds were readily observed without prior fractionation. By comparing 18eV EI Fourier transform ion cyclotron resonance mass spectra of unprocessed and processed diesel fuels, we were able to identify which heteroatom-containing species were removed by processing.
Near-IR imaging system for measuring temperatures in a low-NOx combustor
Authors: Beer Stephen K. , Woodruff Steven D. , Dera Thaddeus M. , Tucker Mark S.
Published: February 2006

A system to measure temperatures O(1500K) in the fused quartz liner of a research combustor is discussed. A standard black/white charge-coupled device camera was used with an 800nm bandpass filter to thermally image high-emissivity paint strips on the inside and outside surfaces of the liner, a requirement for heat-flow model evaluations. Signals were viewed in real time with a framegrabber and simultaneously recorded to videotape for postrun analysis. This system is inexpensive compared to commercial mid- and long-wave IR thermal imagers and more sensitive to temperature differences through the use of bandpass filters for spectral selection of near-infrared wavelengths.
Comment on “Energy principle in the Boozer model” [Phys. Plasmas 12, 112504 (2005)]
Authors: Boozer Allen H.
Published: February 2006

V. D. Pustovitov has asserted [Phys. Plasmas 12, 112504 (2005)] that a fundamental flaw exists in the mathematical formulation of the plasma response used in the VALEN code [Bialek et al., Phys. Plasmas 8, 2170 (2001)] for calculations of resistive wall mode effects. It is shown that the VALEN formulation gives the standard answer for the perturbed energy δW for the case of an ideal plasma that is surrounded by a perfectly conducting wall, which is the example Pustovitov claimed served as a direct proof that the VALEN formulation did not conserve energy.
Subgrid modeling in particle-laden channel flow
Authors: Kuerten J. G. M.
Published: February 2006

Direct numerical simulation (DNS) and large-eddy simulation (LES) of particle-laden turbulent channel flow, in which the particles experience a drag force, are investigated for two subgrid models and several Reynolds and Stokes numbers. In this flow, turbophoresis leads to an accumulation of particles near the walls. The objectives of the work are to investigate the accuracy of the subgrid models studied with respect to particle behavior and to explain the observed particle behavior predicted by the different models. The focus is on particle dispersion and mean particle motion in the direction normal to the walls of the channel. For a low Reynolds number, it is shown that the turbophoresis and particle velocity fluctuations are reduced compared to DNS, if the filtered fluid velocity calculated in the LES is used in the particle equation of motion. This is a combined effect of the disregard of the subgrid scales in the fluid velocity and the inadequacy of the subgrid model. Better agreement with DNS is obtained if an inverse filtering model, which was recently proposed, is incorporated into the particle equation. This model is shown to enhance turbophoresis and particle velocity fluctuations in actual LES. The results of the approximate deconvolution model (ADM) agree better with DNS results than results of the dynamic eddy-viscosity model. This can be explained from the better prediction of the fluid velocity statistics by ADM and the better correspondence of the subgrid models adopted in the fluid and particle equations. Although the differences between the two subgrid models become smaller, similar conclusions are obtained at a higher Reynolds number. Compared to fourth-order interpolation of the fluid velocity to the particle position, second-order interpolation approximately cancels the effect of the subgrid model in the particle equation of motion.
Does the Use of Natural Stimuli Facilitate Amodal Completion in Pigeons?
Authors: Aust Ulrike , Huber Ludwig
Published: February 2006

Three experiments were carried out to investigate whether amodal completion in pigeons can be facilitated by the use of colour photographs instead of highly artificial stimuli such as geometrical shapes. Ten pigeons were trained in a go/no-go procedure to discriminate between photographs of complete and of incomplete pigeon figures. In the subsequent test, the birds classified pictures of partly occluded pigeons as though they were complete (experiment 1). However, we found evidence that classification was based on spurious stimulus features that paralleled the intended class rule of figural completeness versus incompleteness. In particular, classification was shown to be guided by white background gaps that separated the parts of the fragmented pigeon figures (experiment 2), as well as by cues related to overall Gestalt (experiment 3). In summary, the present results indicate that the use of more natural stimuli such as photographs instead of geometrical shapes is insufficient for providing amodal completion in pigeons. It is suggested that a combination of various cues, including, eg, 3-D information and common motion in addition to surface and contour properties, may be required to induce a perceptual bias favouring visual completion of occluded portions.
Perceiving Patterns of Play in Dynamic Sport Tasks: Investigating the Essential Information Underlying Skilled Performance
Authors: Williams A Mark , Hodges Nicola J , North Jamie S , Barton Gabor
Published: February 2006

The perceptual-cognitive information used to support pattern-recognition skill in soccer was examined. In experiment 1, skilled players were quicker and more accurate than less-skilled players at recognising familiar and unfamiliar soccer action sequences presented on film. In experiment 2, these action sequences were converted into point-light displays, with superficial display features removed and the positions of players and the relational information between them made more salient. Skilled players were more accurate than less-skilled players in recognising sequences presented in point-light form, implying that each pattern of play can be defined by the unique relations between players. In experiment 3, various offensive and defensive players were occluded for the duration of each trial in an attempt to identify the most important sources of information underpinning successful performance. A decrease in response accuracy was observed under occluded compared with non-occluded conditions and the expertise effect was no longer observed. The relational information between certain key players, team-mates and their defensive counterparts may provide the essential information for effective pattern-recognition skill in soccer. Structural feature analysis, temporal phase relations, and knowledge-based information are effectively integrated to facilitate pattern recognition in dynamic sport tasks.
The Mona Lisa Effect: Is ‘Our’ Lisa Fame or Fake?
Authors: Carbon Claus-Christian , Leder Helmut
Published: February 2006

This demonstration uses one of the most famous human faces, the portrait of Mona Lisa, La Gioconda, by Leonardo da Vinci. Usually, we have a very accurate and stable representation of the exact configuration of such a familiar face. Typically, we are able to rapidly recognise even subtle configural changes. However, here we show that an exposure to specific alterations performed on a familiar face substantially reduces this ability even over a time period as long as 80 min. This demonstration illustrates the flexibility of the perceptual system and adaptation to new information.
Bridging historical and ecological approaches in biogeography
Authors: Crisci Jorge V. , Sala Osvaldo E. , Katinas Liliana , Posadas Paula
Published: February 2006

The practice of biogeography is rooted in disciplines that traditionally have had little intellectual exchange and yielded two complementary biogeographic approaches: ecological and historical biogeography. The aim of this paper is to review alternative biogeographic approaches in the context of spatial analysis. Biogeography can be used to set priorities for conservation of biological diversity, but also to design strategies to control biological invasions and vectors of human diseases, to provide information about the former distribution of species, and to guide development of ecological restoration initiatives, among other applications. But no one of these applications could be fully carried out until an integrative framework on biogeography, which bridges biogeographical historical and ecological paths of thinking, has been developed. Although we do not propose a new biogeographic method, we highlight the causes and consequences of the lack of a conceptual framework integrating ecology and history in biogeography, and how this required framework would allow biogeography to be fully utilised in fields such as conservation.
Par-3 mediates the inhibition of LIM kinase 2 to regulate cofilin phosphorylation and tight junction assembly
Authors: Chen Xinyu , Macara Ian G.
Published: February 2006

The polarity protein Par-3 plays critical roles in axon specification and the establishment of epithelial apico-basal polarity. Par-3 associates with Par-6 and atypical protein kinase C and is required for the proper assembly of tight junctions, but the molecular basis for its functions is poorly understood. We now report that depletion of Par-3 elevates the phosphorylated pool of cofilin, a key regulator of actin dynamics. Expression of a nonphosphorylatable mutant of cofilin partially rescues tight junction assembly in cells lacking Par-3, as does the depletion of LIM kinase 2 (LIMK2), an upstream kinase for cofilin. Par-3 binds to LIMK2 but not to the related kinase LIMK1. Par-3 inhibits LIMK2 activity in vitro, and overexpressed Par-3 suppresses cofilin phosphorylation that is induced by lysophosphatidic acid. Our findings identify LIMK2 as a novel target of Par-3 and uncover a molecular mechanism by which Par-3 could regulate actin dynamics during cell polarization.
Nomenclature for the human Arf family of GTP-binding proteins: ARF, ARL, and SAR proteins
Authors: Kahn Richard A. , Cherfils Jacqueline , Elias Marek , Lovering Ruth C. , Munro Sean , Schurmann Annette
Published: February 2006

The Ras superfamily is comprised of at least four large families of regulatory guanosine triphosphate–binding proteins, including the Arfs. The Arf family includes three different groups of proteins: the Arfs, Arf-like (Arls), and SARs. Several Arf family members have been very highly conserved throughout eukaryotic evolution and have orthologues in evolutionally diverse species. The different means by which Arf family members have been identified have resulted in an inconsistent and confusing array of names. This confusion is further compounded by differences in nomenclature between different species. We propose a more consistent nomenclature for the human members of the Arf family that may also serve as a guide for nomenclature in other species.
On the Interaction of Neomycin with the Slow Vacuolar Channel ofArabidopsis thaliana
Authors: Scholz-Starke Joachim , Carpaneto Armando , Gambale Franco
Published: February 2006

This study investigates the interaction of the aminoglycoside antibiotic neomycin with the slow vacuolar (SV) channel in vacuoles from Arabidopsis thaliana mesophyll cells. Patch-clamp experiments in the excised patch configuration revealed a complex pattern of neomycin effects on the channel: applied at concentrations in the submicromolar to millimolar range neomycin (a) blocked macroscopic SV currents in a voltage- and concentration-dependent manner, (b) slowed down activation and deactivation kinetics of the channel, and most interestingly, (c) at concentrations above 10 μM, neomycin shifted the SV activation threshold towards negative membrane potentials, causing a two-phasic activation at high concentrations. Single channel experiments showed that neomycin causes these macroscopic effects by combining a decrease of the single channel conductance with a concomitant increase of the channel's open probability. Our results clearly demonstrate that the SV channel can be activated at physiologically relevant tonoplast potentials in the presence of an organic effector molecule. We therefore propose the existence of a cellular equivalent regulating the activity of the SV channel in vivo.