bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and experiments of a torso mechanism for the ROBIAN biped robot
Authors: Ouezdou F. B. , Mohamed B. , Scesa V. , Sellaouti R.
Published: October 2005

This paper deals with the design and the experiments of the upper part of the ROBIAN biped robot. The motivation of the ROBIAN project is related to the study of the human being locomotion system. The major application of ROBIAN prototype is the development of a real testing bed of active/passive prosthesis devices enhancing research on the human being locomotion mechanism handicaps. The analysis of the wrench six components exerted by the upper part of a virtual manikin on the locomotion apparatus leads to the identification of two coupling relations. Based on the dynamic equivalence concept between mechanisms, the ROBIAN torso mechanism is identified. This concept leads to a four degrees of freedom mechanism able to reproduce the dynamic effects of the upper limbs during the walking gait. The mechanism parameters are optimized with respect to several design criteria and constraints. Then the prototype is built and mounted on the ROBIAN locomotion apparatus through a six components force sensor. Experimental results presented in this paper validate the proposed approach. The experimental coupling coefficients are identified. The influence of the masses motion on the ZMP trajectory are also given, showing the effectiveness of the torso mechanism contribution during a walking gait.
Mortality of sarus cranes (Grus antigone) due to electricity wires in Uttar Pradesh, India
Authors: SUNDAR K.S.G. , CHOUDHURY B.C.
Published: October 2005

Although overhead electrical wires are known to have caused severe declines of bird populations, there are no studies in India that address this danger, even for endangered species. Rates of mortality, factors affecting mortality and population effects of electrical wires on the globally endangered sarus crane (Grus antigone) were assessed for breeding and non-breeding cranes in Etawah and Mainpuri districts, Uttar Pradesh, India. Non-breeding cranes were most susceptible to wires and, within territories, mortalities were higher for pre-dispersed young. Similar proportions of non-breeding and breeding cranes were killed, together accounting for nearly 1% of the total sarus crane population annually. Supply wires accounted for the majority of sarus crane deaths, and only non-breeding cranes were killed by both supply and high-tension power lines. Non-breeding crane deaths at roost sites were correlated with numbers of roosting birds and numbers of wires at each site. Over 40% of 251 known sarus crane territories had at least one overhead wire posing a risk to breeding adults and pre-dispersed young. A risk index for wires over territories of cranes was computed; mortality was not affected by increasing the number and therefore risk posed by wires. Most crane deaths in territories occurred as a result of wires at edges of territories. Wires around roosting sites, territoriality and age of sarus cranes appear to be the most important factors affecting their mortality due to wires. Mitigation measures will be most effective around roost sites and for wires that border territories of breeding pairs.
Old English i-umlaut (for the umpteenth time)
Authors: ANDERSON JOHN
Published: October 2005

This article offers an account of i-umlaut in Old English based on lexical minimality: the elimination of redundancies from, in this case, the phonological subentries in the lexicon. And the notation is that of Anderson & Ewen (1987), which is based, crucially for the present formulation, on simplex features which may combine in varying proportions. These assumptions combine to favour system-dependent underspecification. In accord with lexical minimality, the approach taken here is also polysystemic: thus, for instance, Old English vowels, even Old English accented vowels, do not enter into only one system of contrasts. The phonology is a system of systems sharing some but not all contrasts. The article attempts to show that on this basis some of the many apparent anomalies that the evidence has been thought to suggest can be resolved in terms of a simple coherent formulation. Concerning the interpretation of this evidence, it is the intention of the article to minimize appeals to phonetic features and phonetic processes not warranted by textual and comparative testimony. It is suggested that lack of attention to polysystemicity and a pervasive indulgence on the part of historical phonologists in phonetic fantasies undermine the conclusions reached by generations of scholars concerning the development of phonological systems, both in general and in particular.
No momentary fancy! The zero ‘complementizer’ in English dialects
Authors: TAGLIAMONTE SALI , SMITH JENNIFER
Published: October 2005

In this paper we analyse variable presence of the complementizer that, i.e. I thinkthat/Øthis is interesting, in a large archive of British dialects. Situating this feature within its historical development and synchronic patterning, we seek to understand the mechanism underlying the choice between that and zero. Our findings reveal that, in contrast to the diachronic record, the zero option is predominant – 91 per cent overall. Statistical analyses of competing factors operating on this feature confirm that grammaticalization processes and grammatical complexity play a role. However, the linguistic characteristics of a previously grammaticalized collocation, I think, exerts a greater effect. Its imprint is visible in multiple internal factors which constrain the zero option in the other contexts. We argue that this recurrent pattern in discourse propels the zero option through the grammar. These findings contribute to research arguing for a strong relationship between frequency and reanalysis in linguistic change.
What is modal about I thought that…?
Authors: DECLERCK RENAAT , REED SUSAN
Published: October 2005

Some nonmodal tense forms (e.g. thought) can trigger one or two kinds of modal interpretation, viz. suspended factuality (implicating present counterfactuality) of the complement clause (I thought you weren't married) or discourse tentativeness (I thought you might lend me your camera). The authors explain how this nonmodal use of the past tense – the thinking is represented as a past fact – can lead to one of these modal interpretations of the complement clause. In doing so they discuss various observations in connection with these and other I thought that…constructions and similar uses of other past-tense and past-perfect forms.
Analogical Modeling and morphological change: the case of the adjectival negative prefix in English
Authors: CHAPMAN DON , SKOUSEN ROYAL
Published: October 2005

This article examines the usefulness of Skousen's Analogical Modeling (AM) for explaining morphological change. In contrast to previous accounts of analogy, AM constitutes a general unified model of language that accounts for both sporadic and systematic changes. AM also provides explicit constraints on analogy that allow explanation of how morphological changes begin, which forms most likely serve as patterns for analogy, and which forms are most likely to change.

AM is then tested on the case of the adjectival negative prefix in English (in-, un-, dis-, etc.), using the Middle and Early Modern English portions of the Helsinki corpus as a basis for prediction. AM was given the task of using forms containing negative prefixes for one time period to predict the prefixes that adjectives would take in the subsequent time period. For each of the roughly seventy-year periods in the corpus, AM was able to predict valid prefixes about 90 percent of the time.
Optimization of bound disjunctive queries with constraints
Authors: GRECO GIANLUIGI , GRECO SERGIO , TRUBITSYNA IRINA , ZUMPANO ESTER
Published: October 2005

This paper presents a technique for the optimization of bound queries over disjunctive deductive databases with constraints. The proposed approach is an extension of the well-known Magic-Set technique and is well-suited for being integrated in current bottom-up (stable) model inference engines. More specifically, it is based on the exploitation of binding propagation techniques which reduce the size of the data relevant to answer the query and, consequently, reduces both the complexity of computing a single model and the number of models to be considered. The motivation of this work stems from the observation that traditional binding propagation optimization techniques for bottom-up model generator systems, simulating the goal driven evaluation of top-down engines, are only suitable for positive (disjunctive) queries, while hard problems are expressed using unstratified negation. The main contribution of the paper consists in the extension of a previous technique, defined for positive disjunctive queries, to queries containing both disjunctive heads and constraints (a simple and expressive form of unstratified negation). As the usual way of expressing declaratively hard problems is based on the guess-and-check technique, where the guess part is expressed by means of disjunctive rules and the check part is expressed by means of constraints, the technique proposed here is highly relevant for the optimization of queries expressing hard problems. The value of the technique has been proved by several experiments.
Integrating design synthesis and assembly of structured objects in a visual design language
Authors: BANYASAD OMID , COX PHILIP T.
Published: October 2005

Computer Aided Design systems provide tools for building and manipulating models of solid objects. Some also provide access to programming languages so that parametrised designs can be expressed. There is a sharp distinction, therefore, between building models, a concrete graphical editing activity, and programming, an abstract, textual, algorithm-construction activity. The recently proposed Language for Structured Design (LSD) was motivated by a desire to combine the design and programming activities in one language. LSD achieves this by extending a visual logic programming language to incorporate the notions of solids and operations on solids. Here we investigate another aspect of the LSD approach, namely, that by using visual logic programming as the engine to drive the parametrised assembly of objects, we also gain the powerful symbolic problem-solving capability that is the forté of logic programming languages. This allows the designer/programmer to work at a higher level, giving declarative specifications of a design in order to obtain the design descriptions. Hence LSD integrates problem solving, design synthesis, and prototype assembly in a single homogeneous programming/design environment. We demonstrate this specification-to-final-assembly capability using the masterkeying problem for designing systems of locks and keys.
Checking modes of HAL programs
Authors: DE LA BANDA MARIC GARCÍA , HARVEY WARWICK , MARRIOTT KIM , STUCKEY PETER J. , DEMOEN BART
Published: October 2005

Recent constraint logic programming (CLP) languages, such as HAL and Mercury, require type, mode and determinism declarations for predicates. This information allows the generation of efficient target code and the detection of many errors at compile-time. Unfortunately, mode checking in such languages is difficult. One of the main reasons is that, for each predicate mode declaration, the compiler is required to appropriately re-order literals in the predicate's definition. The task is further complicated by the need to handle complex instantiations (which interact with type declarations and higher-order predicates) and automatic initialization of solver variables. Here we define mode checking for strongly typed CLP languages which require reordering of clause body literals. In addition, we show how to handle a simple case of polymorphic modes by using the corresponding polymorphic types.
Normal forms for answer sets programming
Authors: COSTANTINI STEFANIA , PROVETTI ALESSANDRO
Published: October 2005

Normal forms for logic programs under stable/answer set semantics are introduced. We argue that these forms can simplify the study of program properties, mainly consistency. The first normal form, called the kernel of the program, is useful for studying existence and number of answer sets. A kernel program is composed of the atoms which are undefined in the Well-founded semantics, which are those that directly affect the existence of answer sets. The body of rules is composed of negative literals only. Thus, the kernel form tends to be significantly more compact than other formulations. Also, it is possible to check consistency of kernel programs in terms of colorings of the Extended Dependency Graph program representation which we previously developed. The second normal form is called 3-kernel. A 3-kernel program is composed of the atoms which are undefined in the Well-founded semantics. Rules in 3-kernel programs have at most two conditions, and each rule either belongs to a cycle, or defines a connection between cycles. 3-kernel programs may have positive conditions. The 3-kernel normal form is very useful for the static analysis of program consistency, i.e. the syntactic characterization of existence of answer sets. This result can be obtained thanks to a novel graph-like representation of programs, called Cycle Graph which presented in the companion article Costantini (2004b).
Kurzversion des Big Five Inventory (BFI-K):
Authors: Rammstedt Beatrice , John Oliver P.
Published: October 2005

Zusammenfassung. Die zunehmende Etablierung des Fünf-Faktoren-Modells der Persönlichkeit hat zur Folge, dass die so genannten “Big Five“ vermehrt auch in Anwendungskontexten erhoben werden sollen. Da jedoch gerade in diesen Bereichen die Untersuchungszeit oft stark begrenzt ist, sind die herkömmlichen Verfahren zur Erfassung der fünf Faktoren oft zu umfangreich. In der vorliegenden Studie wurde deshalb ein Fragebogen, das BFI-K, entwickelt, das mit 21 Items bzw. einer durchschnittlichen Bearbeitungsdauer unter 2 Minuten als extrem ökonomisch angesehen werden kann. Die Ergebnisse belegen zufriedenstellende psychometrische Kennwerte für das BFI-K. Neben ausreichenden Reliabilitäten konnten sowohl die faktorielle Validität des Verfahrens als auch hohe Übereinstimmungen mit Bekanntenurteilen und mit anderen etablierten Verfahren zu Erfassung des Fünf-Faktoren-Modells bestätigt werden.
Discriminating dynamical patterns in burned and unburned vegetational covers by using SPOT‐VGT NDVI data
Authors: Telesca Luciano , Lasaponara Rosa
Published: October 2005

To detect fire‐induced variability in vegetational dynamics, a time series 1998 to 2003 of Normalized Difference Vegetation Index (NDVI) from SPOT‐VEGETATION sensor was analyzed for burned and unburned test sites located in the Italian Peninsula. The statistical analysis was performed by using the detrended fluctuation analysis (DFA), which permits the detection of persistent properties in nonstationary signal fluctuations. A comparison of results obtained for sites in “healthy condition ” (fire un‐unaffected) and in “ill condition” (fire affected) showed that fires contribute in increasing the persistence of time dynamics of vegetation. This result indicates that fires drive unstable patterns in vegetational dynamics of burned areas. The adopted methodology could be fruitfully applied to investigate other types of vegetational stresses.
Transition probabilities of a string oscillator subject to impulsive collisions with a heavy mass point
Authors: Teubner Max
Published: October 2005

Impulsive linear collisions between a string oscillator (a one-dimensional particle in a box) and a mass point are studied quantum mechanically. In the limit of a very heavy mass point (which corresponds classically to many collisions during a single encounter) the transition probabilities are determined exactly. The result permits a discussion of the mixed quantum-classical regime where the collider becomes almost classical while the oscillator remains quantum mechanical. While the average transition probabilities Pm→n are well reproduced by the Ehrenfest mean-field approximation, the prediction for the superimposed high-frequency resonance structure is qualitatively wrong for a genuine quantum oscillator. Only if the oscillator is also almost classical and if (m−n)2μ⪡m, where μ is the mass ratio collider∕oscillator, this structure is correctly predicted by the Ehrenfest approximation.
Semiclassical nonadiabatic dynamics using a mixed wave-function representation
Authors: Garashchuk Sophya , Rassolov Vitaly A. , Schatz George C.
Published: October 2005

Nonadiabatic effects in quantum dynamics are described using a mixed polar/coordinate space representation of the wave function. The polar part evolves on dynamically determined potential surfaces that have diabatic and adiabatic potentials as limiting cases of weak localized and strong extended diabatic couplings. The coordinate space part, generalized to a matrix form, describes transitions between the surfaces. Choice of the effective potentials for the polar part and partitioning of the wave function enables one to represent the total wave function in terms of smooth components that can be accurately propagated semiclassically using the approximate quantum potential and small basis sets. Examples are given for two-state one-dimensional problems that model chemical reactions that demonstrate the capabilities of the method for various regimes of nonadiabatic dynamics.
Fluorescence intermittency in blinking quantum dots: Renewal or slow modulation?
Authors: Bianco Simone , Grigolini Paolo , Paradisi Paolo
Published: October 2005

We study the time series produced by blinking quantum dots, by means of an aging experiment, and we examine the results of this experiment in the light of two distinct approaches to complexity, renewal and slow modulation. We find that the renewal approach fits the result of the aging experiment, while the slow modulation perspective does not. We make also an attempt at establishing the existence of an intermediate condition.
Parametric study of streak breakdown mechanism in Hartmann flow
Authors: Zienicke E. A. , Krasnov D.
Published: October 2005

Our goal in this study is the identification of the regions of stability and instability of laminar Hartmann flow against the transition to turbulence. The Hartmann flow is characterized by two dimensionless parameters: the Reynolds number, R, based on the thickness of the Hartmann layer and the Hartmann number, Ha. In a previous paper [Krasnov et al., J. Fluid Mech. 504, 183 (2004)] it has been shown that the transition takes place by a two-step mechanism—optimal two-dimensional (2D) perturbation plus a 3D random perturbation at maximum grown 2D perturbation—leading to the streak breakdown scenario. By numerical simulations based on this two-step mechanism, a parametric study is carried out and three major results are established: (1) the critical Reynolds number is determined for higher Hartmann numbers (Ha=40,100) to reach the parameter values of the recent experiment of Moresco and Alboussière [J. Fluid Mech. 504, 167 (2004)], a very good agreement is found. (2) For moderate Hartmann numbers (Ha=10,15,20) the actual minimum size of 2D optimal and 3D random perturbations necessary to trigger a transition to turbulence is determined depending on the Reynolds number (350⩽R⩽1000). (3) For a higher Reynolds number (2000⩽R⩽4000), it is shown that the transition is possible by random 3D perturbations alone, and the minimum size of the perturbations is determined.
Optical properties of the BaMgAl10O17:Eu2+ phosphor coated with SiO2 for a plasma display panel
Authors: Jung I. Y. , Cho Y. , Lee S. G. , Sohn S. H. , Kim D. K. , Lee D. K. , Kweon Y. M.
Published: October 2005

In order to improve the luminance of blue emission of the plasma display panel (PDP), BaMgAl10O17:Eu2+ (BAM) phosphors were synthesized and were coated with SiO2. It was revealed that the surface coating of phosphors with SiO2 leads to an increase in luminance intensity of PDP devices. This seems to be due to the increase of the excitation light which is transmitted into the phosphor, i.e., an effective vacuum ultraviolet absorption of the phosphor via SiO2. The experimental results suggest that the surface coating of BAM with SiO2a is a way to improve the luminance of the PDP.
Three-dimensional self-consistent simulation of single-qubit operation by modulation of the hyperfine interaction in phosphors-doped metal-oxide-semiconductor structure
Authors: Lu M. , Melnikov D. V. , Chung I.-J. , Leburton J.-P.
Published: October 2005

We study the hyperfine interaction in the Kane solid-state quantum computer device structure [Nature (London) 393, 133 (1998)] by solving self-consistently three-dimensional Poisson and Kohn-Sham equations and taking into account the nonisotropic effective mass at each of the six degenerate minima in the silicon conduction band. Specifically, we calculate the hyperfine interaction coefficient from the electron wave-function solution within the envelope function approximation and investigate its variations as a function of gate voltages and impurity position. In addition, we also consider the effect of the gate design on the hyperfine interaction modulation. We show that the hyperfine interaction between the donor electron and donor nucleus is extremely sensitive to all these parameters.
Low-acceptor-concentration GaInNAs grown by molecular-beam epitaxy for high-current p-i-n solar cell applications
Authors: Ptak A. J. , Friedman D. J. , Kurtz Sarah , Reedy R. C.
Published: October 2005

We report GaInNAs grown by solid-source molecular-beam epitaxy (MBE) with background acceptor concentrations less than 1014cm−3, yielding depletion widths in excess of 3μm. GaInNAs p-i-n solar cells fabricated from this low-acceptor-concentration material show greatly increased photocurrents and internal quantum efficiencies close to unity for band gaps as low as 1.15eV. The low acceptor concentrations may be due to low levels of background impurities, such as hydrogen and carbon, in the MBE-grown layers. We discuss the dependence of the acceptor concentration on the substrate temperature used for GaInNAs growth.
A study of spot evolution in hot refractory cathodes of high-pressure arcs
Authors: Muñoz-Serrano E. , Colomer V. , Casado E.
Published: October 2005

In this paper the behavior of the cathode spot in atmospheric pressure arc is studied from a dynamic point of view and later applied to a specific case of a tungsten refractory cathode. For this, a model of the cathode region was developed. In this model the tungsten atoms proceeding from the cathode evaporation, which were all supposed to be ionized in the presheath, returned to the cathode surface as ions, provoking a heating of this surface. Therefore, the model allowed us to evaluate the importance of those atoms. Furthermore, different mechanisms of the electron emission from the cathode surface were considered as function of the spot temperature and the electric-field strength. This model of the cathode region allowed getting important parameters in the study of the dynamics of the cathode spot such as total current density, which is necessary for the calculation of Joule heating effect, and the total-energy flux density, which was incorporated as a boundary condition for the solution of the heat conduction equation in the cathode. The dependence of these parameters on the temperature of the cathode surface in contact with the plasma introduced nonlinearities in the equations. The model takes into account the different phase changes that take place in the cathode as well as the thermal ablation of the melted cathode and the dependence on the temperature of the physical magnitudes that characterize the cathode material. In this way, it is possible to get the time evolution of the temperature distribution in the cathode and to study the spot dynamics on the cathode surface. Three different values of the initial cathode voltage drop were used, U0=15, 20, and 25V, which cover a wide range of working conditions. The cathode spot was assumed to be placed on a crater. For U0=15V, the crater radius increases in time until it reaches a critical value when the energy balance principle is broken. This leads to spot death and its jump to another position on the cathode surface. Nevertheless for higher-voltage drops, U0=20 and 25V, the spot reaches a stationary regime before arriving at that critical state and the spot remains fixed. This way, the maximum spot radius and the possibility of the spot moving or not appear naturally during the numerical development of the model. The results of this model show that the contribution of the evaporated and later ionized cathode atoms is not significant in comparison with the electrons and plasmagen ions contributions. In this sense these atoms need not be taken into account in the cathode region models for hot refractory cathodes in atmospheric pressure arcs.
Density of states in tritiated amorphous silicon obtained with the constant photocurrent method
Authors: Pisana Simone , Costea Stefan , Kosteski Tome , Shmayda Walter T. , Kherani Nazir P. , Zukotynski Stefan
Published: October 2005

The constant photocurrent method was implemented to determine the density of states in tritiated hydrogenated amorphous silicon below the Fermi level. The tritiated hydrogenated amorphous silicon samples were grown using a mixture of silane and tritium gases in the dc saddle-field deposition system. Over time the tritium incorporated in the amorphous silicon undergoes beta decay and transmutation into helium. The transmutation leads to an increase in the density of states in the energy gap of the material. These states are linked to silicon dangling-bond defects. Given its well-characterized decay process, tritium can be used as an experimental tool to study the behavior of hydrogenated amorphous silicon thin films as a function of their defect state density. The density-of-states information in this work indicates a dominant peak of doubly occupied dangling bonds (D−) positioned 1.24eV below the conduction band. The defect density was monitored in time showing an increase of more than two orders of magnitude over a period of 20days and a decrease of similar magnitude upon thermal annealing.
Structure and magnetic properties of Co–Cr solid-solution nanocapsules prepared by arc discharge
Authors: Ma S. , Wang Y. B. , Geng D. Y. , Li J. , Zhang Z. D.
Published: October 2005

The Co(Cr) and Cr(Co) solid-solution nanocapsules have been fabricated by arc discharge in atmosphere of argon and hydrogen. The structure and composition of the nanocapsules of two types are investigated by means of x-ray diffraction, high-resolution transmission electron microscope, and energy dispersive spectroscopy analysis. The Cr(Co) and Co(Cr) nanocapsules show shell/core structure with different shape characteristics. The magnetic properties of the Co(Cr) and Cr(Co) nanocapsules are studied. The blocking temperatures of the Co(Cr) and Cr(Co) nanocapsules are determined to be 96 and 14K, respectively. The magnetization of Cr(Co) nanocapsules is contributed by the uncompensated moments in bcc chromium lattice and small cobalt particles.
Spontaneous compositional superlattice and band-gap reduction in Si-doped AlxGa1−xN epilayers
Authors: Gao M. , Lin Y. , Bradley S. T. , Ringel S. A. , Hwang J. , Schaff W. J. , Brillson L. J.
Published: October 2005

Combined transmission electron microscopy (TEM), x-ray diffraction, and cathodoluminescence spectroscopy measurements of AlxGa1−xN thin films grown by molecular-beam epitaxy reveal spontaneous modulation, phase separation, and band-gap reductions that vary systematically with AlN mole fraction across the full alloy series. At low AlN mole fraction (x⩽0.5), AlGaN epilayers display pronounced phase separation. With increasing AlN mole fraction, phase separation is strongly suppressed by the formation of spontaneous modulation, which high spatial resolution TEM techniques unambiguously determine to be an atomic-scale compositional superlattice. Superlattice-induced reductions from band gaps expected for compositionally disordered epilayers exceed several hundred meV for the Al-rich average alloy composition.
Neither Global Nor Standard: Corporate Strategies in the New Era of Labor Standards
Authors: Christopherson Susan , Lillie Nathan
Published: October 2005

Two multinational retail firms, IKEA and Wal-Mart, illuminate the implications of a new era of labor standards—focused on the transnational firm. Global labor standards are increasingly enforced through transnational corporation (TNC) adherence to voluntary codes rather than through national labor regulation. Nonetheless, privatized labor-standards regimes within TNCs continue to be influenced by the national market governance framework in the TNC country of origin. Although, in principle, labor standards are arrived at through global political processes, in practice they are applied in conjunction with TNC production and marketing strategies. The way in which corporate objectives intersect with labor practices is different from one TNC to another, depending in large part on political and regulatory influences in the country of origin of a particular TNC.
Shifting Ground: Emerging Global Corporate-Governance Standards and the Rise of Fiduciary Capitalism
Authors: Hawley James P , Williams Andrew T
Published: October 2005

In this paper we examine the long-term interests that large institutional owners (for example, the California Public Employees' Retirement System, Hermes, and the Universities Superannuation Scheme) have in the development of global corporate governance standards, especially as governance standards increasingly become intertwined with other standards and regime parameters involved in the globalization debates. We argue that institutional owners have a unique perspective and voice with which to contribute to the formulation of global standards in a variety of areas on the basis of their long-term financial interests. This conclusion is supported by an analytic review of the current state of global corporate governance, including multilateral initiatives (for example, the Organisation for Economic Co-operation and Development, the World Bank); an analysis of significant institutional investors, the role of various rating agencies (for example, Fitch, Moody's), the International Corporate Governance Network, and the growing role of various nongovernmental organizations (for example, the Coalition for Environmentally Responsible Economics, the Carbon Disclosure Project) in relation to corporate governance.
Role of interleukin‐6 in hypoxic regulation of intestinal iron absorption
Authors: Raja Kishor B. , O. Latunde‐Dada Gladys , Peters Timothy J. , McKie Andrew T. , Simpson Robert J.
Published: October 2005

The regulation of intestinal iron absorption is not fully understood. Hepcidin, a liver‐produced peptide, has recently been identified as a negative regulator of iron absorption in various conditions associated with altered iron metabolism (e.g. inflammation, anaemia, hypoxia). It is not clear whether these perturbants share a common signalling pathway. In this study, the importance of the cytokine interleukin‐6 (IL‐6) was investigated in the hypoxic mouse model. Hypoxia was associated with increased levels of circulating IL‐6, decreased liver hepcidin mRNA and increased iron absorption (especially MT). A significant positive correlation existed between the total iron uptake and IL‐6 levels in circulation. IL‐6 per se, though inducing hepcidin mRNA, failed to affect basal iron absorption. The adaptive response to absorption following the hypoxic exposure was, however, more prominent if mice had been treated concurrently with IL‐6. This enhancement in absorption occurred even though hepcidin mRNA was not significantly changed. Similar prominent responses were seen with both human and mouse IL‐6. Anti‐IL‐6 antiserum normalised iron absorption in mice exposed to hypoxia, because of a reduction in the MT. These data indicate that IL‐6 can influence iron absorption (especially MT) during the hypoxic exposure, but via a mechanism independent of hepcidin.
Randomised comparison of two B‐cell purging protocols for patients with B‐cell non‐Hodgkin lymphoma: in vivo purging with rituximab versus ex vivo purging with CliniMACS CD34+ cell enrichment device
Authors: van Heeckeren Willem J. , Vollweiler Jennifer , Fu Pingfu , Cooper Brenda W. , Meyerson Howard , Lazarus Hillard M. , Simic Alexandra , Laughlin Mary J. , Gerson Stanton L. , Koç Omer N.
Published: October 2005

We investigated the feasibility, safety and efficacy of two B‐cell purging methods in patients with CD20+ non‐Hodgkin lymphoma (NHL) receiving autologous stsem cell transplantation. Myeloid and immune recoveries between the methods were compared. Twenty‐seven patients were randomised to either in vivo purging with rituximab or ex vivo purging by CD34+ cell selection. Both purging methods were efficient at eliminating B‐cells in infusates. When compared with in vivo purging, ex vivo purging was associated with CD34+ cell loss and delayed median neutrophil (10 d vs. 11 d) and platelet (12·5 d vs. 17 d) count recoveries. Lymphocyte recovery was similar in both groups, but immunoglobulin recovery was delayed after in vivo purging. Late‐infectious complications were few in both arms. At a median follow‐up of 27 months, 2‐year probabilities of event‐free survival (EFS) rates were 81% for in vivo purging and 76% for ex vivo purging (P = 0·66). When compared with 53 unpurged patients, all 27 purged patients had improved 3‐year probabilities of overall survival (89% vs. 70%, P = 0·014) and a trend for improved EFS (78% vs. 57%, P = 0·075). In conclusion, although both purging methods were feasible and safe, rituximab purging was superior as it did not impair CD34+ cell mobilisation and was associated with faster myeloid recovery. Further studies are needed to determine whether rituximab purging is more effective than the use of unpurged autografts.
Phytoplankton community assembly in a large boreal lake – deterministic pathways or chaotic fluctuations?
Authors: SOININEN JANNE , TALLBERG PETRA , HORPPILA JUKKA
Published: October 2005

1. The concepts of community assembly and succession are closely related, yet their foci differ slightly. Succession describes the trajectory of species replacements during the temporal development of the community, while assembly also allows that a locality can harbour different communities depending on the events in the near past of community development.

2. The aims of this study were (i) to examine the year‐to‐year variation in phytoplankton community assembly among basins of different trophy and disturbance in the large boreal Lake Hiidenvesi and (ii) to assess community persistence and diversity among basins in relation to prevailing environmental factors.

3. The results showed that the assembly did not follow similar trajectories each year. According to mean similarity analyses, there was a large degree of variability especially among the groups of samples collected in the same months of different years. Similarity between pairs of consecutive samples was highest in a cold year (1998) in all basins. Community assembly was most unpredictable in the basin of highest productivity, perhaps implying that the number of alternative stable states increased towards higher productivity. Our data also showed a strong unimodal relationship between phytoplankton species richness and grazing by cladoceran zooplankton in the basin of highest trophy.

4. This study showed that phytoplankton community assembly exhibited large variability among the years. This implies that different environmental conditions might be the strongest mechanism behind this pattern, given that the degree of community similarity paralleled the year‐to‐year variation in mean temperature. Unravelling the patterns in community assembly has a number of important implications, especially for the monitoring of ecological impacts based only on snapshots of biological assemblages.
Genetic diversity and historical population structure in the New Zealand mayfly Acanthophlebia cruentata
Authors: SMITH PETER J. , MARGARET MCVEAGH S. , COLLIER KEVIN J.
Published: October 2005

1. Nucleotide sequences of a 280 base pair region of the cytochrome b gene were used to assess genetic diversity and to infer population histories in the New Zealand mayfly Acanthophlebia cruentata.

2. A hierarchial examination of populations from 19 streams at different spatial scales in the central and northern North Island of New Zealand found 34 haplotypes. A common haplotype was found in all central region streams and unique haplotypes in northern streams. Several central streams had region specific haplotypes with genetically differentiated populations at the 70–100 km scale.

3. Haplotype diversity was high (0.53–0.8) at most sites, but low (0–0.22) in some central sites. amova analyses found significant genetic diversity among regions (69%) and among catchments (58%). Most population pairwise FST tests were significant, with non‐significant pairwise tests among sites in the central region and pairs of sites between neighbouring streams.

4. The levels of sequence divergence are interpreted as the result of Pleistocene divergence in multiple refugia, leading to the evolution of regionally unique haplotypes. The low diversity in some central region populations may result from recent colonisation following local extinctions, associated with volcanic events.
The role of transcriptional coactivator TRAP220 in myelomonocytic differentiation
Authors: Urahama Norinaga , Ito Mitsuhiro , Sada Akiko , Yakushijin Kimikazu , Yamamoto Katsuya , Okamura Atsuo , Minagawa Kentaro , Hato Akio , Chihara Kazuo , Roeder Robert G. , Matsui Toshimitsu
Published: October 2005

The TRAP220 subunit of the thyroid hormone receptor‐associated polypeptide transcription coactivator complex (TRAP/Mediator complex), mammalian counterpart of the yeast Mediator complex, is proposed to act on a variety of major and specific biological events through physical interactions with nuclear receptors. The vitamin D receptor (VDR) and retinoic acid receptor (RAR), coupled with retinoid X receptor (RXR), are nuclear receptors which have important roles for monopoiesis and granulopoiesis, respectively. In this study, we present the functional role of TRAP220 in nuclear receptor‐mediated monopoiesis and granulopoiesis. The mouse Trap220−/– yolk sac hematopoietic progenitor cells were resistant to 1,25‐dihydroxyvitamin D3‐stimulated differentiation into monocytes/macrophages. Furthermore, flow cytometric analyses showed that HL‐60 cells, human promyelocytic leukemia cell line, wherein TRAP220 was down‐regulated, did not differentiate efficiently into monocytes and granulocytes by stimulation with 1,25‐dihydroxyvitamin D3 and all‐trans retinoic acid, correspondingly. The expression of direct target genes of VDR or RAR, as well as the differentiation marker genes, was low in the knockdown cells. These results indicated a crucial role of TRAP220 in the optimal VDR‐ and RAR‐mediated myelomonocytic differentiation processes in mammalian hematopoiesis.
Characterization of blond and Star Ruby (red) Jaffa grapefruits using antioxidant and electrophoretic methods
Authors: Gorinstein Shela , Drzewiecki Jerzy , Park Yong‐Seo , Jung Soon‐Teck , Kang Seong‐Gook , Haruenkit Ratiporn , Toledo Fernando , Katrich Elena , Trakhtenberg Simon
Published: October 2005

Antioxidant and electrophoretic methods were used to characterize the quality differences between blond and Star Ruby (red) grapefruits. Dietary fibre, minerals and trace elements, total polyphenols, anthocyanins, flavonoids, phenolic and ascorbic acids were also determined. The antioxidant potential of red grapefruit was significantly higher than that of the blond fruit (P < 0.05) and correlated well with the total polyphenols (R2 from 0.8456 to 0.9711). In both the cultivars studied, thirty‐two electrophoretic bands were detected [sodium dodecyl‐polyacrylamide gel eletrophoresis (SDS‐PAGE)]. The main electrophoretic bands occurred between 20 and 43 kDa in both grapefruits with few minor differences between the varieties. Our findings indicate the following (i) red grapefruit is preferable: it has a higher concentration of bioactive compounds and antioxidant potential than the blond; (ii) 1, 1‐diphenyl‐2‐picrylhydrazyl (DPPH) test is a more sensitive method for the determination of antioxidant potential; (iii) there are some minor differences in electrophoretic patterns; (iv) antioxidant and electrophoretic methods are a good combination for characterization of differences of the same citrus fruits.
Temperature effects on seed maturity and dormancy cycles in an aquatic annual, Najas marina, at the edge of its range
Authors: HANDLEY RICHARD J. , DAVY ANTHONY J.
Published: October 2005

Najas marina is a summer annual of shallow lakes that reaches its distributional limit in the Norfolk Broads of eastern England. Seeds are shed in autumn and overwinter in lake sediments.

We investigated the influence of growing‐season length on seed maturity and germinability and the cumulative effects of winter temperatures on patterns of germinability. Seeds were stratified for up to 1 year and tested for germinability at 4‐week intervals. Data‐loggers recorded temperatures simultaneously at the field site and in the cold room. Cumulative temperature below a threshold (thermal time) was used to relate behaviour in cold storage to phenology.

Most seeds were dormant at collection. Cold storage of imbibed seed resulted in loss of dormancy. The proportion of non‐dormant seeds peaked after a cold treatment equivalent to one winter, i.e. coinciding with favourable temperatures for germination in the field. Continued cold stratification resulted in a cycle of secondary dormancy and its subsequent relief; the thermal time characterizing the second, lower, peak in germinability coincided approximately with that attained in the field in the second spring after collection.

Shortening the growing season of Najas marina, by collecting material before natural senescence was complete, reduced the proportion of mature seeds, lowered average germinability and increased germination times.

The thermal capacity of water bodies causes a lag in spring warming, whereas declining light becomes limiting in autumn. Najas marina is crucially dependent on the length of growing season to produce sufficient viable seed. A low‐temperature requirement to break seed dormancy prevents inappropriate autumn germination. In a prolonged winter (necessarily followed by a shorter growing season), a significant proportion of seed would go into secondary dormancy and remain in the seed bank until the second spring.

In annual plants, such requirements for warm summers and cold winters could contribute to a continental‐climate distribution in northern Europe. In the case of Najas marina this might explain its limit at the eastern extremity of England and thus its rarity.
Spatial genetic structure links between soil seed banks and above‐ground populations ofPrimula modestain subalpine grassland
Authors: SHIMONO A. , UENO S. , TSUMURA Y. , WASHITANI I.
Published: October 2005

The spatial genetic structure of soil seed banks establishes the initial template for development of spatial genetic structure in above‐ground plants, but is rarely evaluated.

We used kinship coefficients to analyse the fine‐scale spatial genetic autocorrelation of plants and of seed banks from different soil depths forPrimula modestaat a subalpine fen site on Mt Asama, central Japan.

The spatial genetic structure of surface seeds (0–1 cm depth) was significant, while deeper seeds (1–5 cm depth) had no significant genetic structure. We also detected a more pronounced spatial genetic association between the surface seeds and flowering genets than between the deeper seeds and flowering genets.

These results suggest that the surface seed bank accounts for a large proportion of the previous season's seed dispersal and therefore represents the transient seed bank, whereas the deeper (persistent) seed bank pools the reproductive output of multiple generations.

Directional analysis indicated that secondary dispersal by running water modifies the spatial genetic structure and extends dispersal distances. Over time, this may impact on the spatial pattern of soil seeds, possibly accounting for the absence of spatial genetic structure in deeper seeds.

Emerging seedlings and flowering ramets were strongly clustered together at distances up to 20 cm. Surviving seedlings were aggregated at short distances because of the patchy spatial distribution of safe sites for establishment, allowing development and strengthening of the marked fine‐scale spatial genetic structure.
Cleavage of intracellular hepatitis C RNA in the virus core protein coding region by deoxyribozymes
Authors: Trepanier J. , Tanner J. E. , Momparler R. L. , Le O. N. L. , Alvarez F. , Alfieri C.
Published: October 2005

Summary.  Hepatitis C virus (HCV) infection represents an important global health problem. Current antiviral therapeutics for HCV have proven inadequate in stemming the disease process. A novel therapeutic strategy involves the use of deoxyribozymes, also known as DNA enzymes or DNAzymes. These catalytic DNA molecules, designed to target and cleave specific RNA sequences, have shown promise in in vitro experimental models for various diseases and may serve as an alternative or adjunct to current HCV drug therapy. We designed and tested several deoxyribozymes that can bind and cleave highly conserved RNA sequences encoding the HCV core protein in in vitro systems. One of these deoxyribozymes reduced the level of our HCV RNA target by 32% and 48% after 24 h of cell exposure when tested in human hepatoma and epithelial cell lines, respectively. As this deoxyribozyme showed significant cleavage activity against HCV core protein target RNA in human cells, it may have potential as a therapeutic candidate for clinical trial in HCV infected patients.
Chemically‐mediated host‐plant location and selection by root‐feeding insects
Authors: Johnson Scott N. , Gregory Peter J.
Published: October 2005

Abstract.  Recent studies have shown that root‐feeding insects can be of considerable importance in terms of agricultural damage, their indirect impacts on above‐ground herbivores and their efficacy as biocontrol agents of weeds. To date, isolated studies have made it difficult to identify the mechanisms by which soil‐dwelling insects locate and select host‐plant roots. This review synthesizes 78 studies describing root location and selection. Soil insect herbivores do not rely on encountering roots at random, but orientate towards them using semiochemicals that enable specialist insects to distinguish host‐plants from unsuitable plants. Secondary plant metabolites released into the rhizosphere (alcohols, esters and aldehydes representing 37% of reported examples) underpin host‐plant location and recognition, with 80% having ‘attractant’ properties. Insects feeding on a limited range of plants tend to exploit host‐specific secondary metabolites, whereas nonspecialist feeders appear to use more general semiochemicals. When insects reach the roots, contact chemosensory cues act as either ‘phagostimulants’ (48% of the compounds being sugars) or feeding ‘deterrents’ (notably phenolic compounds). Twenty studies conclude that CO2 is the major primary plant metabolite that allows insects to locate to roots. However, several features of CO2 emissions from roots mitigate against it as a precise location cue. In addition to its lack of specificity, gradients of root emitted CO2 do not persist for long periods and vertical gradients of CO2 in the soil tend to be stronger than horizontal gradients. A conceptual model is presented, emphasizing the importance of soil properties (e.g. porosity, moisture) on chemical diffusion and insect motility.