bluuebunny/crossref_metadata_2025 huggingface dataset:
Radixin is a constituent of stereocilia in hair cells
Authors: Pataky F. , Pironkova R. , Hudspeth A. J.
Published: February 2004

Proteins of the ezrin-radixin-moesin family are ubiquitous constituents of the submembrane cortex, especially in epithelial cells. Earlier biochemical results suggested that a protein of this family occurs in the hair bundle, the cluster of actin-filled stereocilia that serves as the mechanoreceptive organelle of each hair cell in the inner ear. We prepared antipeptide antisera directed against chicken radixin and ezrin and demonstrated their specificity and absence of crossreactivity. When used in immunocytochemical studies of isolated hair cells, anti-radixin produced an intense band of labeling at the bases of hair bundles from the chicken, frog, mouse, and zebrafish. Electron microscopic immunocytochemistry disclosed that radixin labeling commenced in the stereociliary taper, peaked in the lower stereociliary shaft, and declined progressively toward the hair bundle's top. Labeling with anti-ezrin produced no signal in hair bundles. Radixin is thus a prominent constituent of stereocilia, where it may participate in anchoring the “pointed” ends of actin filaments to the membrane.
The
Vibrio cholerae
chitin utilization program
Authors: Meibom Karin L. , Li Xibing B. , Nielsen Alex T. , Wu Cheng-Yen , Roseman Saul , Schoolnik Gary K.
Published: February 2004

Chitin, an insoluble polymer of GlcNAc, is an abundant source of carbon, nitrogen, and energy for marine microorganisms. Microarray expression profiling and mutational studies of
Vibrio cholerae
growing on a natural chitin surface, or with the soluble chitin oligosaccharides (GlcNAc)
2–6
, GlcNAc, or the glucosamine dimer (GlcN)
2
identified three sets of differentially regulated genes. We show that (
i
) ChiS, a sensor histidine kinase, regulates expression of the (GlcNAc)
2–6
gene set, including a (GlcNAc)
2
catabolic operon, two extracellular chitinases, a chitoporin, and a PilA-containing type IV pilus, designated ChiRP (
chi
tin-
r
egulated
p
ilus) that confers a significant growth advantage to
V. cholerae
on a chitin surface; (
ii
) GlcNAc causes the coordinate expression of genes involved with chitin chemotaxis and adherence and with the transport and assimilation of GlcNAc; (
iii
) (GlcN)
2
induces genes required for the transport and catabolism of nonacetylated chitin residues; and (
iv
) the constitutively expressed MSHA pilus facilitates adhesion to the chitin surface independent of surface chemistry. Collectively, these results provide a global portrait of a complex, multistage
V. cholerae
program for the efficient utilization of chitin.
Prostaglandin E
2
-increased thermosensitivity of anterior hypothalamic neurons is associated with depressed inhibition
Authors: Tabarean Iustin V. , Behrens M. Margarita , Bartfai Tamas , Korn Henri
Published: February 2004

Temperature responses of anterior hypothalamic neurons are considered key elements in the regulation of the temperature setpoint of homeotherms. We have investigated the sensitivity to warming of cultured neurons of the AH from mice with electrophysiological and immunocytochemical techniques. In control experiments, only ≈9% of the 3- to 5-week-old cells exhibited changes of their basic firing rate when the temperature was raised from 37°C to 40°C. This ratio was increased to 27% after the cultures were “primed” by adding prostaglandin E
2
(PGE
2
), an endogenous pyrogen, in the extracellular medium. In these neurons the firing rate was significantly increased, and the frequency of the gamma γ-aminobutyric acid (GABA) inhibitory postsynaptic potentials was markedly decreased. In contrast, the resting potential and membrane resistance of the recorded cells remained unchanged. PGE
2
was found to decrease the level of phosphorylation of the extracellular signal-regulated kinases 1 and 2 in a subset of GABAergic neurons that express the E-prostanoid receptor type 3. Inhibition of ERK1/2 by U0126 mimicked the effects of PGE
2
. These data indicate that PGE
2
acts primarily on the excitability of GABAergic presynaptic cells, most likely via alterations of voltage-gated K
+
channels. Our results also suggest that far from being an inherent property of a specialized class of neurons, the degree of thermosensitivity can be strongly modulated by synaptic activity and is a more adaptive property of hypothalamic neurons than previously thought.
Optical imaging of visually evoked responses in prosimian primates reveals conserved features of the middle temporal visual area
Authors: Xu Xiangmin , Collins Christine E. , Kaskan Peter M. , Khaytin Ilya , Kaas Jon H. , Casagrande Vivien A.
Published: February 2004

Optical imaging of intrinsic cortical responses to visual stimuli was used to characterize the organization of the middle temporal visual area (MT) of a prosimian primate, the bush baby (
Otolemur garnetti
). Stimulation with moving gratings revealed a patchwork of oval-like domains in MT. These orientation domains could, in turn, be subdivided into zones selective to directional movements that were mainly orthogonal to the preferred orientation. Similar, but not identical, zones were activated by movements of random dots in the preferred direction. Orientation domains shifted in preference systematically either around a center to form pinwheels or as gradual linear shifts. Stimuli presented in different portions of the visual field demonstrated a global representation of visual space in MT. As optical imaging has revealed similar features in MT of New World monkeys, MT appears to have retained these basic features of organization for at least the 60 million years since the divergence of prosimian and simian primates.
Asian and Euro-American parents’ ethnotheories of play and learning: Effects on preschool children’s home routines and school behaviour
Authors: Parmar Parminder , Harkness Sara , Super Charles M.
Published: February 2004

Asian and Euro-American parents of preschool-aged children were interviewed concerning their beliefs about the nature and purpose of play; they also completed two questionnaires and a diary of their children’s daily activities. The children’s teachers were interviewed and provided information about the behaviour of the children in preschool. The Euro-American parents were found to believe that play is an important vehicle for early development, while the Asian parents saw little developmental value in it. On the other hand, the Asian parents believed more strongly than the Euro-Americans in the importance of an early start in academic training for their children. These contrasting beliefs were instantiated in parental practices at home regarding the use of time and the provision of toys. At preschool, the Asian children were similar to the Euro-Americans on a standardised behavioural measure but they were described by their teachers as initially more academically advanced than the Euro-American children, and as showing different patterns of play and social interaction. The implications of these results for home–school relations and the design of early education programmes are discussed.
Understanding the Time-Asymmetry of Radiation
Authors: North Jill
Published: February 2004

I discuss the nature of the puzzle about the time-asymmetry of radiation and argue that its most common formulation is flawed. As a result, many proposed solutions fail to solve the real problem. I discuss a recent proposal of Mathias Frisch as an example of the tendency to address the wrong problem. I go on to suggest that the asymmetry of radiation, like the asymmetry of thermodynamics, results from the initial state of the universe.
Are Our Best Physical Theories (Probably and/or Approximately) True?
Authors: Barrett Jeffrey A.
Published: February 2004

There is good reason to suppose that our best physical theories are false: In addition to its own internal problems, the standard formulation of quantum mechanics is logically incompatible with special relativity. I will also argue that we have no concrete idea what it means to claim that these theories are approximately true.
Underdetermination and the Problem of Identical Rivals
Authors: Magnus P. D.
Published: February 2004

If two theory formulations are merely different expressions of the same theory, then any problem of choosing between them cannot be due to the underdetermination of theories by data. So one might suspect that we need to be able to tell distinct theories from mere alternate formulations before we can say anything substantive about underdetermination, that we need to solve the problem of identical rivals before addressing the problem of underdetermination. Here I consider two possible solutions: Quine proposes that we call two theories identical if they are equivalent under a reconstrual of predicates, but this would mishandle important cases. Another proposal is to defer to the particular judgements of actual scientists. Consideration of an historical episode—the alleged equivalence of wave and matrix mechanics—shows that this second proposal also fails. Nevertheless, I suggest, the original suspicion is wrong; there are ways to enquire into underdetermination without having solved the problem of identical rivals.
Engineering Design and Adaptation
Authors: Richardson Robert C.
Published: February 2004

Reverse engineering is a matter of inferring adaptive function from structure. The utility of reverse engineering for evolutionary biology has been a matter of controversy. I offer a simple taxonomy of the uses of engineering design in assessing adaptation, with a variety of illustrations. The plausibility of applications of engineering design reflects the specific way the models are elaborated and derived.
Ontology Schmontology? Identity, Individuation, and Fock Space
Authors: Gordon Bruce L.
Published: February 2004

The aim of this paper is modest. It is argued that if the nature of the “equivalence” between first-quantized particle theories and second-quantized (Fock Space) theories is examined closely, if the inadequacies of de Muynck's “indexed particle” version of Fock Space are recognized, and if the question is not begged against modal metaphysics, then van Fraassen's attempted deflation of ontological issues in quantum theory can be seen to fail.
Biology and a Priori Laws
Authors: Elgin Mehmet
Published: February 2004

In this paper, I investigate the nature of a priori biological laws in connection with the idea that laws must be empirical. I argue that the epistemic functions of a priori biological laws in biology are the same as those of empirical laws in physics. Thus, the requirement that laws be empirical is idle in connection with how laws operate in science. This result presents a choice between sticking with an unmotivated philosophical requirement and taking the functional equivalence of laws seriously and modifying our philosophical account. I favor the latter.
Ecological Kinds and Ecological Laws
Authors: Mikkelson Gregory M.
Published: February 2004

Ecologists typically invoke “law-like” generalizations, ranging over “structural” and/or “functional” kinds, in order to explain generalizations about “historical” kinds (such as biological taxa)—rather than vice versa. This practice is justified, since structural and functional kinds tend to correlate better with important ecological phenomena than do historical kinds. I support these contentions with three recent case studies. In one sense, therefore, ecology is, and should be, more nomothetic, or law-oriented, than idiographic, or historically oriented. This conclusion challenges several recent philosophical claims about the nature of ecological science.
A Model-Theoretic Account of Representation (Or, I Don't Know Much about Art…but I Know It Involves Isomorphism)
Authors: French Steven
Published: February 2004

Discussions of representation in science tend to draw on examples from art. However, such examples need to be handled with care given a) the differences between works of art and scientific theories and b) the accommodation of these examples within certain philosophies of art. I shall examine the claim that isomorphism is neither necessary nor sufficient for representation and I shall argue that there exist accounts of representation in both art and science involving isomorphism which accommodate the apparent counterexamples and, moreover, allow us to understand how “impossible” artistic objects and inconsistent scientific theories can be said to represent.
Sensitivity and selectivity in protein structure comparison
Authors: Sierk Michael L. , Pearson William R.
Published: February 2004

Seven protein structure comparison methods and two sequence comparison programs were evaluated on their ability to detect either protein homologs or domains with the same topology (fold) as defined by the CATH structure database. The structure alignment programs Dali, Structal, Combinatorial Extension (CE), VAST, and Matras were tested along with SGM and PRIDE, which calculate a structural distance between two domains without aligning them. We also tested two sequence alignment programs, SSEARCH and PSI‐BLAST. Depending upon the level of selectivity and error model, structure alignment programs can detect roughly twice as many homologous domains in CATH as sequence alignment programs. Dali finds the most homologs, 321–533 of 1120 possible true positives (28.7%–45.7%), at an error rate of 0.1 errors per query (EPQ), whereas PSI‐BLAST finds 365 true positives (32.6%), regardless of the error model. At an EPQ of 1.0, Dali finds 42%–70% of possible homologs, whereas Matras finds 49%–57%; PSI‐BLAST finds 36.9%. However, Dali achieves >84% coverage before the first error for half of the families tested. Dali and PSI‐BLAST find 9.2% and 5.2%, respectively, of the 7056 possible topology pairs at an EPQ of 0.1 and 19.5, and 5.9% at an EPQ of 1.0. Most statistical significance estimates reported by the structural alignment programs overestimate the significance of an alignment by orders of magnitude when compared with the actual distribution of errors. These results help quantify the statistical distinction between analogous and homologous structures, and provide a benchmark for structure comparison statistics.
Using lanthanide ions to align troponin complexes in solution: Order of lanthanide occupancy in cardiac troponin C
Authors: Gay Grant L. , Lindhout Darrin A. , Sykes Brian D.
Published: February 2004

The potential for using paramagnetic lanthanide ions to partially align troponin C in solution as a tool for the structure determination of bound troponin I peptides has been investigated. A prerequisite for these studies is an understanding of the order of lanthanide ion occupancy in the metal binding sites of the protein. Two‐dimensional {1H, 15N} HSQC NMR spectroscopy has been used to examine the binding order of Ce3+, Tb3+, and Yb3+ to both apo‐ and holo‐forms of human cardiac troponin C (cTnC) and of Ce3+ to holo‐chicken skeletal troponin C (sTnC). The disappearance of cross‐peak resonances in the HSQC spectrum was used to determine the order of occupation of the binding sites in both cTnC and sTnC by each lanthanide. For the lanthanides tested, the binding order follows that of the net charge of the binding site residues from most to least negative; the N‐domain calcium binding sites are the first to be filled followed by the C‐domain sites. Given this binding order for lanthanide ions, it was demonstrated that it is possible to create a cTnC species with one lanthanide in the N‐domain site and two Ca2+ ions in the C‐domain binding sites. By using the species cTnC•Yb3+•2 Ca2+ it was possible to confer partial alignment on a bound human cardiac troponin I (cTnI) peptide. Residual dipolar couplings (RDCs) were measured for the resonances in the bound 15N‐labeled cTnI129–148 by using two‐dimensional {1H, 15N} inphase antiphase (IPAP) NMR spectroscopy.
Nucleotide‐induced switch in oligomerization of the AAA+ ATPase ClpB
Authors: Akoev Vladimir , Gogol Edward P. , Barnett Micheal E. , Zolkiewski Michal
Published: February 2004

ClpB is a member of the bacterial protein‐disaggregating chaperone machinery and belongs to the AAA+ superfamily of ATPases associated with various cellular activities. The mechanism of ClpB‐assisted reactivation of strongly aggregated proteins is unknown and the oligomeric state of ClpB has been under discussion. Sedimentation equilibrium and sedimentation velocity show that, under physiological ionic strength in the absence of nucleotides, ClpB from Escherichia coli undergoes reversible self‐association that involves protein concentration‐dependent populations of monomers, heptamers, and intermediate‐size oligomers. Under low ionic strength conditions, a heptamer becomes the predominant form of ClpB. In contrast, ATPγS, a nonhydrolyzable ATP analog, as well as ADP stabilize hexameric ClpB. Consistently, electron microscopy reveals that ring‐type oligomers of ClpB in the absence of nucleotides are larger than those in the presence of ATPγS. Thus, the binding of nucleotides without hydrolysis of ATP produces a significant change in the self‐association equilibria of ClpB: from reactions supporting formation of a heptamer to those supporting a hexamer. Our results show how ClpB and possibly other related AAA+ proteins can translate nucleotide binding into a major structural transformation and help explain why previously published electron micrographs of some AAA+ ATPases detected both six‐ and sevenfold particle symmetry.
Directed discovery of bivalent peptide ligands to an SH3 domain
Authors: Ferguson Monique R. , Fan Xiuzhen , Mukherjee Munia , Luo Jinquan , Khan Raza , Ferreon Josephine C. , Hilser Vincent J. , Shope Robert E. , Fox Robert O.
Published: February 2004

The Caenorhabditis elegans SEM‐5 SH3 domains recognize proline‐rich peptide segments with modest affinity. We developed a bivalent peptide ligand that contains a naturally occurring proline‐rich binding sequence, tethered by a glycine linker to a disulfide‐closed loop segment containing six variable residues. The glycine linker allows the loop segment to explore regions of greatest diversity in sequence and structure of the SH3 domain: the RT and n‐Src loops. The bivalent ligand was optimized using phage display, leading to a peptide (PP‐G4‐L) with 1000‐fold increased affinity for the SEM‐5 C‐terminal SH3 domain over that of a natural ligand. NMR analysis of the complex confirms that the peptide loop segment is targeted to the RT and n‐Src loops and parts of the β‐sheet scaffold of this SH3 domain. This binding region is comparable to that targeted by a natural non‐PXXP peptide to the p67phox SH3 domain, a region not known to be targeted in the Grb2 SH3 domain family. PP‐G4‐L may aid in the discovery of additional binding partners of Grb2 family SH3 domains.
Structure of the archaeal translation initiation factor aIF2β from Methanobacterium thermoautotrophicum: Implications for translation initiation
Authors: Gutiérrez Pablo , Osborne Michael J. , Siddiqui Nadeem , Trempe Jean‐François , Arrowsmith Cheryl , Gehring Kalle
Published: February 2004

aIF2β is the archaeal homolog of eIF2β, a member of the eIF2 heterotrimeric complex, implicated in the delivery of Met‐tRNAiMet to the 40S ribosomal subunit. We have determined the solution structure of the intact β‐subunit of aIF2 from Methanobacterium thermoautotrophicum. aIF2β is composed of an unfolded N terminus, a mixed α/β core domain and a C‐terminal zinc finger. NMR data shows the two folded domains display restricted mobility with respect to each other. Analysis of the aIF2γ structure docked to tRNA allowed the identification of a putative binding site for the β‐subunit in the ternary translation complex. Based on structural similarity and biochemical data, a role for the different secondary structure elements is suggested.
Cytoarchitecture and musculotopic organization of the facial motor nucleus in Cebus apella monkey
Authors: Horta‐Júnior J. A. C. , Tamega O. J. , Cruz‐Rizzolo R. J.
Published: February 2004

The architecture and musculotopic organization of the facial motor nucleus in the Cebus apella monkey (a New World primate) were investigated using histological techniques and a multiple labelling strategy, in which horseradish peroxidase‐conjugated neuroanatomical tracers (CTB‐HRP and WGA‐HRP) and fluorescent tracers were injected into individual facial muscles. The facial motor nucleus was formed by multipolar motoneurons and had an ovoid shape, with its rostrocaudal axis measuring on average 1875 µm. We divided the nucleus into four different subnuclei: medial, intermediate, dorsal and lateral. Retrograde labelling patterns revealed that individual muscles were innervated by longitudinal functional columns of motoneurons. The columns of the orbicularis oculi, zygomaticus, orbicularis oris, auricularis superior, buccinator and platysma muscles were located in the dorsal, intermediate, lateral, medial, lateral and intermediate subnuclei, respectively. However, the motoneuron columns of the levator labii superioris alaeque nasi muscle and frontalis muscle could not be associated with a specific subnucleus. The present results confirm previous studies regarding the musculotopic organization of the facial motor nucleus. However, we observed some particularities in terms of the relative size of each column in C. apella, which might be related to the functional and behavioral importance of each muscle in the particular context of this primate.
Perspectives on hyperphalangy: patterns and processes
Authors: Fedak Tim J. , Hall Brian K.
Published: February 2004

Hyperphalangy is a digit morphology in which increased numbers of phalanges are arranged linearly within a digit beyond the plesiomorphic condition. We analyse patterns and processes of hyperphalangy by considering previous definitions and occurrences of hyperphalangy among terrestrial and secondarily aquatic extant and fossil taxa (cetaceans, ichthyosaurs, plesiosaurs and mosasaurs), and recent studies that elucidate the factors involved in terrestrial autopod joint induction. Extreme hyperphalangy, defined as exceeding a threshold condition of 4/6/6/6/6, is shown only to be found among secondarily aquatic vertebrates with a flipper limb morphology. Based on this definition, hyperphalangy occurs exclusively in digits II and III among extant cetaceans. Previous reports of cetacean embryos having more phalanges than adults is clarified and shown to be based on cartilaginous elements not ossified phalanges. Developmental prerequisites for hyperphalangy include lack of cell death in interdigital mesoderm (producing a flipper limb) and maintenance of a secondary apical ectodermal ridge (AER), which initiates digit elongation and extra joint patterning. Factors of the limb‐patterning pathways located in the interdigital mesoderm, including bone morphogenetic proteins (BMPs), BMP antagonists, fibroblast growth factors (FGFs), growth/differentiation factor‐5 (GDF‐5), Wnt‐14 and ck‐erg, are implicated in maintenance of the flipper limb, secondary AER formation, digit elongation and additional joint induction leading to hyperphalangy.
Photoperiod and temperature affect the life cycle of a subtropical cockroach, Opisoplatia orientalis: seasonal pattern shaped by winter mortality
Authors: Zhu Dao‐Hong , Tanaka Seiji
Published: February 2004

Abstract.  Opisoplatia orientalis is an ovoviviparous cockroach living in the subtropical areas in Japan. Both adults and nymphs overwinter on Hachijo Island (33°N). The nymphs sampled before and after overwintering showed a similar pattern in frequency distribution of head widths with a definite peak of fifth instars. The present study was conducted to determine how this pattern was formed by investigating the effects of photoperiod and temperature on development and reproduction. Photoperiod influenced the number of nymphal instars, resulting in a longer duration of nymphal development at LD 12 : 12 h than at LD 16 : 8 h. However, the rate of development at each instar was only affected to a small extent by photoperiod and no sign of diapause was detected. It was suggested that the photoperiodic response controlling the number of nymphal instars might have evolved to adjust the timing of adult emergence and reproduction to the favourable season. The prereproductive period and time intervals between nymph depositions were prolonged as temperature declined, but there was no evidence for diapause in adults. Mortality occurred in eggs and embryos inside of the body of the females during winter. Thus, it was inferred that female adults would reset ovarian development in spring and deposit nymphs in summer simultaneously, and these nymphs would reach the fifth instar before winter comes. This winter mortality hypothesis was supported by experiments in which reproductive activity and mortality were monitored for field‐collected adults under either constant or changing temperature conditions simulating those in the field.
Presence of haemocyte‐like cells in coccinellid reflex blood
Authors: Karystinou Alexandra , Thomas Alison P. M. , Roy Helen E.
Published: February 2004

Abstract.  Contrary to current assumptions, the reflex blood of two‐spot ladybirds, Adalia bipunctata, and seven‐spot ladybirds, Coccinella septempunctata, contains haemocyte‐like cells. Furthermore, DNA can be extracted and amplified from coccinellid reflex blood, confirming the presence of haemocyte‐like cells and demonstrating a nondestructive method of DNA extraction.
Parental and direct effects of photoperiod and temperature on the induction of larval diapause in the blow fly Lucilia sericata
Authors: Tachibana Shin‐Ichiro , Numata Hideharu
Published: February 2004

Abstract.  Lucilia sericata (Meigen) (Diptera: Calliphoridae) shows a facultative diapause in the third, and final larval, instar after the cessation of feeding. The effects of photoperiod and temperature on the induction and duration of diapause were examined in parental (G0) and current (G1) generations. Insects of the G0 generation were reared under four combinations of conditions, involving two photoperiods, LD 16 : 8 and LD 12 : 12 h, and two temperatures, 25 and 20 °C. The G1 generation, present in the eggs laid by these insects, were transferred to 10 combinations of conditions, involving the above two photoperiods and five temperatures, 25, 20, 17.5, 15 and 12.5 °C. In the G1 generation, the time from hatching to cessation of feeding was significantly affected by temperature only, whereas the induction of diapause was influenced by both photoperiod and temperature experienced by the G0 as well as the G1 generation. Short‐day and low‐temperature conditions in the G0 and in the G1 generation had diapause‐inducing effects. In this species, it is likely that, for purposes of acquiring reliable seasonal information, induction of diapause is sensitive to environmental factors both in the G0 and G1 generations. The function of high‐intensity diapause, induced by short‐day conditions and high temperature in the parental generation, appeared to be the prevention of accidental pupariation in warm autumn weather.
Substrate usage and its regulation during flight and swimming in the backswimmer, Notonecta glauca
Authors: Gäde Gerd , Auerswald Lutz , Predel Reinhard , Marco Heather G
Published: February 2004

Abstract.  The metabolites that are generally used by insects during exercise are present in quite different concentrations in the haemolymph of the backswimmer Notonecta glauca L. Lipids are most abundant (between 10 and 20 mg/mL), whereas carbohydrates (2–3 mg/mL) and proline (approximately 1 mg/mL) are at very low concentrations. Injection of an extract of conspecific corpora cardiaca causes pronounced hyperlipaemia in the backswimmer. A neuropeptide with the same effect was isolated from the corpora cardiaca in a single high‐performance liquid chromatography (HPLC) step; the primary sequence was deduced from mass spectrometric measurements (matrix‐assisted laser desorption/ionization‐time of flight and electrospray quadrupol time‐of‐flight mass spectrometry) of whole corpora cardiaca, and the mass was confirmed in the HPLC fraction that had adipokinetic activity. The biologically active octapeptide has the sequence pGlu‐Val‐Asn‐Phe‐Ser‐Pro‐Ser‐Trp amide, which was characterized previously from the corpora cardiaca of the Emperor dragonfly, Anax imperator, and denoted Anaim‐adipokinetic hormone (AKH). The synthetic Anaim‐AKH peptide causes lipid mobilization when injected at a dose of 1 pmol into N. glauca. When other synthetic AKH members that occur in Hemiptera are injected into N. glauca at the same dose, the hyperlipaemic responses are significantly lower than after injection of Anaim‐AKH. Because only lipids increase upon activity, such as continuous swimming for 1 h or during a 1‐h rest period after a 3‐min flight episode in the laboratory, it is assumed that Anaim‐AKH serves as a true adipokinetic hormone in the backswimmer during bouts of natural swimming and flight.
The Three Faces of Defeasibility in the Law
Authors: Prakken Henry , Sartor Giovanni
Published: February 2004

Abstract. In this paper we will analyse the issue of defeasibility in the law, taking into account research carried out in philosophy, artificial intelligence and legal theory. We will adopt a very general idea of legal defeasibility, in which we will include all different ways in which certain legal conclusions may need to be abandoned, though no mistake was made in deriving them. We will argue that defeasibility in the law involves three different aspects, which we will call inference‐based defeasibility, process‐based defeasibility, and theory‐based defeasibility. Only the integration of these three perspectives allows us to provide a satisfactory account of the role of defeasibility in legal reasoning.
Shareholding structure, depoliticization and firm performance
Authors: Wong Sonia M. L. , Opper Sonja , Hu Ruyin
Published: February 2004

In this study we use a dataset that provides information on Chinese Communist Party grassroots organizations’ political control over decision‐making in China's listed firms. Specifically, we examine how different types of shareholders affect (1) the party's level of decision‐making power and (2) the implications of party control for firm performance. We obtain two major results. First, we find that the proportion of shares held by domestic individual shareholders is negatively related to the party's level of decision‐making power. Second, we find that the existence of large institutional investors is associated with a reduced negative performance effect of party control. Our results suggest that both the exit and the voice channels may offer mechanisms for depoliticizing China's listed firms and improving their performance. This study both addresses an important corporate governance issue relevant to China's listed firms and offers interesting information in terms of comparative studies of corporate governance and reform strategies in transitional economies.
A golden shot: how ballistic single cell transformation boosts the molecular analysis of cereal–mildew interactions
Authors: Panstruga Ralph
Published: February 2004

Despite considerable technical progress in past years, genetic manipulation of cereals remains a tedious task. Thus, transgenic approaches in monocot species to study plant–microbe interactions are limited to date. Transient gene expression in single epidermal cells mediated by particle bombardment has emerged recently as an attractive alternative for testing the impact of (over‐)expressing or silencing single host genes in the context of cereal–powdery mildew interactions. The ease and pace of this assay enables the analysis of candidate genes within a fraction of the time needed to generate stable transgenic lines. Genetically encoded fluorescent sensors expressed in single cells are ideally suited to monitor gene expression, subcellular protein localization and changes of physiological parameters at the single cell level. Likewise, single cell gene expression can be employed to study protein–protein interactions of fluorophore‐tagged polypeptides by fluorescence resonance energy transfer or fluorescence (cross) correlation spectroscopy. An integrated approach, combining single cell gene expression technology with modern cell biological tools and single cell sampling via laser capture microdissection, may provide in‐depth insights into the molecular events in epidermal host cells in the course of cereal–mildew interactions.
Developmental expression and biochemical properties of a β‐1,4‐endoglucanase family in the soybean cyst nematode, Heterodera glycines
Authors: Gao Bingli , Allen R. , Davis E. L. , Baum T. J. , Hussey R. S.
Published: February 2004

The soybean cyst nematode, Heterodera glycines, produces β‐1,4‐endoglucanases (cellulases) that are secreted during infection of soybean. The gene structures of three, hg‐eng‐4, hg‐eng‐5 and hg‐eng‐6, of the six β‐1,4‐endoglucanase genes, all family 5 glycosyl hydrolases previously identified from H. glycines, are presented here. Furthermore, we present the detailed expression analyses of β‐1,4‐endoglucanase genes as well as the biochemical properties of four H. glycines endoglucanase enzymes. Two of the endoglucanases, HG‐ENG‐5 and HG‐ENG‐6, differed significantly in their amino acid sequence of the catalytic domains and their gene structure from that of the other four β‐1,4‐endoglucanases. Quantitative real‐time RT‐PCR revealed distinct developmental expression differences among the hg‐eng family members during the early stages of parasitism and relatively low expression levels in late parasitic stages, with the exception of the adult male stage for some eng genes. Recombinant HG‐ENGs degraded carboxymethylcellulose and optimum enzyme activity ranged from pH 5.5 for HG‐ENG‐5 to pH 8 for HG‐ENG‐6. EDTA, Ca2+, Co2+, Mg2+ and Fe2+ did not affect enzyme activity of any ENG protein, whereas Zn2+, Cu2+ and Mn2+ inhibited enzyme activity from 23% to 73% in some cases. In tests with 12 different polysaccharide substrates, enzyme activity was restricted to β‐1,4 linkages with all ENG proteins tested. Only HG‐ENG‐5 and HG‐ENG‐6 had relatively high activity on xylan and slightly degraded microcrystalline cellulose. Together, these data reveal distinct differences in expression and biochemistry of cyst nematode parasitism genes and proteins, respectively, and cast light on the intricate interactions between a parasitic animal and its plant host.
Reprogramming plant gene expression: a prerequisite to geminivirus DNA replication
Authors: Hanley‐Bowdoin Linda , Settlage Sharon B. , Robertson Dominique
Published: February 2004

Geminiviruses constitute a large family of plant‐infecting viruses with small, single‐stranded DNA genomes that replicate through double‐stranded intermediates. Because of their limited coding capacity, geminiviruses supply only the factors required to initiate their replication and use plant nuclear DNA polymerases to amplify their genomes. Many geminiviruses replicate in differentiated cells that no longer contain detectable levels of host DNA polymerases and associated factors. To overcome this barrier, geminiviruses induce the accumulation of DNA replication machinery in mature plant cells by reprogramming host gene expression. The mammalian DNA tumour viruses activate host genes required for DNA replication by binding to the retinoblastoma protein, a negative regulator of cell cycle progression, and relieving repression through the E2F family of transcription factors. In this review, we discuss recent experiments showing that geminiviruses also modulate components of the retinoblastoma/E2F transcription regulatory network to induce quiescent plant cells to re‐enter the cell cycle and regain the capacity to support high levels of DNA replication. Regulation of the cell division cycle and its integration with developmental pathways is complex, with many factors, including hormones, sucrose and environmental signals, controlling re‐entry into the plant cell cycle. Geminivirus interactions with these regulatory networks are likely to determine if and where they can replicate their genomes in different plant tissues and hosts.
The influence of follicular migration on T‐cell differentiation
Authors: Smith Karen M. , Brewer James M. , Mowat Allan Mci. , Ron Yacov , Garside Paul
Published: February 2004

The sequence of events that leads to the development of a T‐dependent B‐cell response has been studied for many years and much attention has focused on the importance of these interactions for the B cell and the antibody response. While a role for B cells in T‐cell memory has been demonstrated, the cellular and molecular mechanisms underlying this are unclear and the importance for T cells to migrate into follicles and interact with B cells has received relatively little attention. These interactions between T and B lymphocytes are facilitated by a co‐ordinated series of migration events within lymph nodes and here we propose that this migration and these events are essential for the terminal differentiation of all CD4+ T cells and without it tolerance may result.
An anti‐inflammatory oligopeptide produced by Entamoeba histolytica down‐regulates the expression of pro‐inflammatory chemokines
Authors: Utrera‐Barillas Dolores , Velazquez Juan R. , Enciso Antonio , Muñoz Cruz Samira , Rico Guadalupe , Curiel‐Quesada Everardo , Teran Luis M. , Kretschmer Roberto R.
Published: February 2004

Axenically grown Entamoeba histolytica produces a pentapeptide (Met‐Gln‐Cys‐Asn‐Ser) with anti‐inflammatory properties that, among others, inhibits the in vitro and in vivo locomotion of human monocytes, sparing polymorphonuclear leucocytes from this effect [hence the name originally given: Monocyte Locomotion Inhibitory Factor (MLIF)]. A synthetic construct of this peptide displays the same effects as the native material. We now added MLIF to resting and PMA‐stimulated cells of a human monocyte cell line and measured the effect upon mRNA and protein expression of pro‐inflammatory chemokines (RANTES, IP‐10, MIP‐1α, MIP‐1β, MCP‐1, IL‐8, I‐309 and lymphotactin) and the shared CC receptor repertoire. The constitutive expression of these chemokines and the CC receptors was unaffected, whereas induced expression of MIP‐1α, MIP‐1β, and I‐309, and that of the CCR1 receptor – all involved in monocyte chemotaxis – was significantly inhibited by MLIF. This suggests that the inhibition of monocyte functions by MLIF may not only be exerted directly on these cells, but also – and perhaps foremost – through a conglomerate down‐regulation of endogenous pro‐inflammatory chemokines.
Identification of CD4+ T cell epitopes of Taenia solium paramyosin
Authors: López‐Moreno H. S. , Correa D. , Laclette J. P. , Ortiz‐Navarrete V. F.
Published: February 2004

T cell mediated response is involved in a protective immune response against experimental cysticercosis conferred by immunization with Taenia solium paramyosin (TPmy) to BALB/c mice. In this study, we analysed the TPmy amino acid sequence for predicted CD4+T cells epitopes. Five different regions of this protein showed that the residues anchor to bind the I‐Admolecule; synthetic peptides containing these epitopes were evaluated for their ability to induce lymphoproliferative responses of spleen cells from TPmy immunized mice. Among them, Tp176 (amino acids 176–192 sequence DDLQRQMADANSAKSRL) was the immunodominant T cell epitope of TPmy. Delineation of this epitope should facilitate analysis of the role of CD4+T cell response in experimental cysticercosis.
IFN‐γ is associated with risk of Schistosoma japonicum infection in China
Authors: Shen L. , Zhang Z. S. , Wu H. W. , Weir R. E. , Xie Z. W. , Hu L. S. , Chen S. Z. , Ji M. J. , Su C. , Zhang Y. , Bickle Q. D. , Cousens S. N. , Taylor M. G. , Wu G. L.
Published: February 2004

Before the start of the schistosomiasis transmission season, 129 villagers resident on a Schistosoma japonicum‐endemic island in Poyang Lake, Jiangxi Province, 64 of whom were stool‐positive for S. japonicum eggs by the Kato method and 65 negative, were treated with praziquantel. Forty‐five days later the 93 subjects who presented for follow‐up were all stool‐negative. Blood samples were collected from all 93 individuals. S. japonicum soluble worm antigen (SWAP) and soluble egg antigen (SEA) stimulated IL‐4, IL‐5 and IFN‐γ production in whole‐blood cultures were measured by ELISA. All the subjects were interviewed nine times during the subsequent transmission season to estimate the intensity of their contact with potentially infective snail habitats, and the subjects were all re‐screened for S. japonicum by the Kato method at the end of the transmission season. Fourteen subjects were found to be infected at that time. There was some indication that the risk of infection might be associated with gender (with females being at higher risk) and with the intensity of water contact, and there was evidence that levels of SEA‐induced IFN‐γ production were associated with reduced risk of infection.
Convergence and Divergence of Random Series
Authors: Pakes Anthony G.
Published: February 2004

This paper amplifies Daley's (1981) criteria for absolute convergence of certain random series by providing a sufficient condition which also is necessary if the summands are independent. Conditions for unconditional and conditional convergence are also given. These results are used to obtain a substantially complete picture of the behaviour of random Dirichlet series of a fairly general type. Behaviour of the partial sums of divergent series is discussed, with particular attention to Dirichlet series.
Kernel Estimation of the Spectral Density of Stationary Random Closed Sets
Authors: Böhm Stephan , Heinrich Lothar , Schmidt Volker
Published: February 2004

A non‐parametric kernel estimator of the spectral density of stationary random closed sets is studied. Conditions are derived under which this estimator is asymptotically unbiased and mean‐square consistent. For the planar Boolean model with isotropic compact and convex grains, an averaged version of the kernel estimator is compared with the theoretical spectral density.
Powers and Products of Regenerative Phenomena
Authors: Kingman J.F.C.
Published: February 2004

The simultaneous occurrence of two independent regenerative phenomena defines a third, whose p‐function is the product of the first two. Thus integer powers of p‐functions are p‐functions. The corresponding result for non‐integer powers (with exponent α > 1) has been proved for discrete time phenomena and for standard continuous time phenomena. There are still open questions, notably whether the class of Markov p‐functions is closed under non‐integer powers. These questions are addressed by means of a new technique which relates the atoms of the canonical measure to ‘kinks’ in the p‐function. This provides new information even for products of p‐functions.
Prediction Regions for Bivariate Extreme Events
Authors: Hall Peter , Tajvidi Nader
Published: February 2004

This paper suggests using a mixture of parametric and non‐parametric methods to construct prediction regions in bivariate extreme‐value problems. The non‐parametric part of the technique is used to estimate the dependence function, or copula, and the parametric part is employed to estimate the marginal distributions. A bootstrap calibration argument is suggested for reducing coverage error. This combined approach is compared with a more parametric one, relative to which it has the advantages of being more flexible and simpler to implement. It also enjoys these features relative to predictive likelihood methods. The paper shows how to construct both compact and semi‐infinite bivariate prediction regions, and it treats the problem of predicting the value of one component conditional on the other. The methods are illustrated by application to Australian annual maximum temperature data.
The Strategy and Attribution Questionnaire: Psychometric properties of a Lithuanian translation in an adolescent sample
Authors: Zukauskiene Rita , Sondaite Jolanta
Published: February 2004

Zukauskiene, R. & Sondaite, J. (2004). The Strategy and Attribution Questionnaire: Psychometric properties of a Lithuanian translation in an adolescent sample. Scandinavian Journal of Psychology, 45, 157–162.

The present study provides a preliminary validation of the Lithuanian version of the Strategy and Attribution Questionnaire (SAQ, Nurmi, et al., 1995), a self‐reported measure of social and cognitive behavioral strategies. An attempt to validate SAQ subscales was made by correlating them with the Youth Self‐Report (Achenbach, 1991) and school grades. This was done with a sample of 14‐ to 17‐year‐old adolescents (N= 734). The results showed that although internal consistency reliabilities were good, they were lower when compared with the original version of SAQ. The SAQ subscales were moderately associated with various validity criteria, such as anxiety/depression, withdrawal, social problems and somatic complaints and school grades. Results also showed moderate correlations between similar strategic components across achievement and affiliative situations. The results provide preliminary evidence for concurrent validity of the Lithuanian version of SAQ.
Crime and the EU's Constitutional Future in an Area of Freedom, Security, and Justice
Authors: Guild Elspeth
Published: February 2004

Abstract:  The European Union is finalising negotiations in respect of a constitution that will define its identity and future. The draft constitution begins with a quote from Thucydides ‘Our constitution . . . is called a democracy because power is in the hands not of a minority but of the greatest number’.1 In this article I look at the proposed constitutional framework of the European Union from the perspective of the gradual realisation of measures in criminal law capable of affecting the lives of individuals. The central question is to what extent the Union is providing itself with the tools to achieve democratic exercise of the power to maintain order and to punish individuals within a single area of freedom, security, and justice. Within the draft constitution an ambiguity arises as regards the principles which underlie this part of the project: mutual recognition and approximation. Mutual recognition of national decisions maintains power within the borders of the state, approximation leads towards a consolidation of power. The extent to which the constitution pulls in two rather different directions and the consequences for the individual are examined here.
The problems with the validity of the diagnosis of brain death
Authors: Sundin‐Huard Deborah , Fahy Kathleen
Published: February 2004

• The diagnosis of brain death as ‘death’ and organ transplantation have been closely historically linked since the mid twentieth century

• It will be argued in this article that the development of a neurological definition of death was introduced to justify the removal of fresh viable organs for transplantation

• Brain death cannot be diagnosed reliably using ‘established practices’

• Improved understanding of the pathophysiology of raised intracranial pressure has challenged our understanding of brain death

• We need to move forward in our conceptualization of phenomenon of profound coma associated with massive brain damage

• If examination for ‘brain death’ is to be carried out at all, there needs to be an examination and re‐evaluation of practices and protocols
Drugs used to promote diuresis: a treatment for fluid balance charts?
Authors: Cleaver Neal
Published: February 2004

• Renal failure is a complex process characterized by the retention of nitrogenous waste products, electrolyte disturbances and decreased urine production

• Diuretics are often prescribed as a treatment for decreased renal functioning

• Diuretics induce urine production by different mechanisms of action

• Diuretic therapy has not been found to decrease mortality nor decrease the need for further intervention

• The current development of national framework standards will provide guidelines for the treatment of all patients suffering acute renal failure