bluuebunny/crossref_metadata_2025 huggingface dataset:
Grb10 mediates insulin-stimulated degradation of the insulin receptor: a mechanism of negative regulation
Authors: Ramos Fresnida J. , Langlais Paul R. , Hu Derong , Dong Lily Q. , Liu Feng
Published: January 2006

Growth factor receptor-bound protein 10 (Grb10) is an adapter protein that interacts with a number of tyrosine-phosphorylated growth factor receptors, including the insulin receptor (IR). To investigate the role of Grb10 in insulin signaling, we generated cell lines in which the expression levels of Grb10 are either overexpressed by stable transfection or suppressed by RNA interference. We found that suppressing endogenous Grb10 expression led to increased IR protein levels, whereas overexpression of Grb10 led to reduced IR protein levels. Altering Grb10 expression levels had no effect on the mRNA levels of IR, suggesting that the modulation occurs at the protein level. Reduced IR levels were also observed in cells with prolonged insulin treatment, and this reduction was inhibited in Grb10-deficient cells. The insulin-induced IR reduction was greatly reversed by MG-132, a proteasomal inhibitor, but not by chloroquine, a lysosomal inhibitor. IR underwent insulin-stimulated ubiquitination in cells, and this ubiquitination was inhibited in the Grb10-suppressed cell line. Together, our results suggest that, in addition to inhibiting IR kinase activity by directly binding to the IR, Grb10 also negatively regulates insulin signaling by mediating insulin-stimulated degradation of the receptor.
Lithium treatment induces a marked proliferation of primarily principal cells in rat kidney inner medullary collecting duct
Authors: Christensen Birgitte Mønster , Kim Young-Hee , Kwon Tae-Hwan , Nielsen Søren
Published: January 2006

Lithium (Li) treatment for 4 wk has previously been shown to increase the fraction of intercalated cells in parallel with a decrease in the fraction of principal cells in the kidney collecting duct (Christensen BM, Marples D, Kim YH, Wang W, Frøkiær J, and Nielsen S. Am J Physiol Cell Physiol 286: C952–C964, 2004; Kim YH, Kwon TH, Christensen BM, Nielsen J, Wall SM, Madsen KM, Frøkiær J, and Nielsen S. Am J Physiol Renal Physiol 285: F1244–F1257, 2003). To study how early this fractional change starts, the origin of the cells and the possible mechanism behind the changes, we did time course studies in rats subjected to different durations of Li treatment (i.e., for 4, 10, and 15 days). Increased urine output was already observed at day 4 of Li treatment with decreased AQP2 levels although not statistically significant. At days 10 and 15, both a significant polyuria and downregulation in AQP2 expression were observed. At day 10, the density of H+-ATPase-positive cells was increased in the IMCD of Li-treated rats and this was further pronounced at day 15. Some of the H+-ATPase-positive cells did not costain with Cl−/HCO3−exchanger AE1, indicating that they were not fully differentiated to type A IC. By double labeling for either H+-ATPase and proliferating-cell nuclear antigen (PCNA) or for AQP4 and PCNA, we found that proliferation mainly occurred in proximal IMCD cells at day 4 and it increased toward the middle part of the IMCD in response to prolonged Li treatment. Most cells expressing PCNA were stained with AQP4 but not with H+-ATPase. Triple-labeling for H+-ATPase, AQP4, and PCNA showed a subset of cells negative for all three proteins or only positive for PCNA. In contrast, a 4-wk recovery period after 4 wk of Li treatment reversed the enhanced proliferative rate to the control levels. In conclusion, the Li-induced increase in the density of intercalated cells is associated with a high proliferative rate of principal cells in the IM-1 and IM-2 rather than a selective proliferation of intercalated cells as expected. This is likely to contribute to the remodeling of the collecting duct after Li treatment.
Does past tense marking indicate the acquisition of the concept of temporal displacement in children's cognitive development?
Authors: Shirai Yasuhiro , Miyata Susanne
Published: January 2006

The acquisition of past tense markers has often been considered to parallel conceptual development in the domain of time (e.g., Weist, 1986). However, the precise relationship between linguistic marking of time in childrenís speech and conceptual development has not been investigated in data-based research. This study analyses longitudinal speech data from four Japanese children to determine whether the use of the past tense form actually coincides with its use to signal past time. The results show that the relationship between contrastive use of the form and truly deictic past is not a straightforward one; for all the children, deictic use emerges later than the contrastive use of past and nonpast forms.
Reflexivity and the psychologist
Authors: Morawski Jill G.
Published: January 2006

Psychologists tend to examine their activities in experimentation with the same objective scientific attitude as they routinely assume in the experimental situation. A few psychologists have stepped outside this closed expistemic practice to undertake reflexive analysis of the psychologist in the laboratory. Three cases of such critical reflexive analysis are considered to better understand the strategies and consequences of confronting what Steve Woolgar has called ‘the horrors of reflexivity’. Reflexive work of William James, Horace Mann Bond, and Saul Rosenzweig are examined: working in the early years of modern experimental psychology these scientists identified limitations in the dominant natural science model of experimentation. Attending to the scientist's own cognitions, social status, and unconscious processes respectively, James, Bond, and Rosenzweig criticized this natural science model and presented methodological and epistemic alternatives. The relative neglect of their constructive observations underscores the resistance to addressing psychology's reflexive dimensions.
Between truth and hope: on Parkinson’s disease, neurotransplantation and the production of the ‘self’
Authors: Moreira Tiago , Palladino Paolo
Published: January 2006

In this article, we argue that contemporary biomedicine is shaped by two, seemingly incommensurable, organizational logics, the ‘regime of truth’ and the ‘regime of hope’. We articulate their features by drawing on debates sparked by the recent clinical trial of a new approach to the treatment of Parkinson’s Disease. We also argue that the ‘self’ is configured in the very same process whereby these two organizational logics interlock and become mutually dependent, so that the ‘self’ might be said to be the effect of a ‘parasitic’ relationship between the regimes of ‘truth’ and ‘hope’. We then bring these two arguments to bear on the contrasting views of the relationship between embodiment and political subjectivity articulated by Michel Foucault and Giorgio Agamben, on the one hand, and Paul Rabinow and Nikolas Rose, on the other hand.
Constructing narratives and reading texts: approaches to history and power struggles between philosophy and emergent disciplines in inter-war France
Authors: Chimisso Cristina
Published: January 2006

In inter-war France, history of philosophy was a very important academic discipline, but nevertheless its practitioners thought it necessary to defend its identity, which was threatened by its vicinity to many other disciplines, and especially by the emergent social sciences and history of science. I shall focus on two particular issues that divided traditional historians of philosophy from historians of science, ethnologists and sociologists, and that became crucial in the definition of the identity of their disciplines: the conception of history and the interpretation of texts. By analysing representative discussions and positions, I shall show that traditional historians of philosophy needed to reassert their own approach to history, which, borrowing the term from Bergson, I define as ‘snapshot’. This approach is focused on a particular idea or text rather than a narrative. I shall also show that history of philosophy, in its traditional form, would have been undermined both intellectually and institutionally by the opposite ‘narrative’ approach of history of science and of the social sciences. Social scientists openly attacked history of philosophy’s methods and, in the eyes of traditional philosophers, its existence as an academic discipline. The same opposition is to be found in evaluation of past texts, which for traditional historians of philosophy were to be read as timeless documents, while for historians of science, ethnologists and sociologists were to be considered as documents exhibiting a particular mentality. However, between these alternatives there were intermediate positions. I shall in particular consider that of Léon Brunschvicg: he embraced a narrative approach and considered texts as documents of different ways of thinking, but at the same time carried on employing philosophical methods and defending the institutional position of philosophy. I shall argue that this was possible partly because of the considerable amount of power he enjoyed at the Sorbonne.
Personalizing web information for patients: linking patient medical data with the web via a patient personal knowledge base
Authors: Al-Busaidi Asma , Gray Alex , Fiddian Nick
Published: January 2006

This paper describes ongoing study that examines problems with existing patient health information sources and investigates an approach for linking (i.e. integrating) data from a patient’s medical record(s) with relevant health information on the web. The aim is to provide patients with simplified, customized and controlled access to web information. Data from patient medical records are extracted and linked with relevant health information on the web through a web search service. These are made available to patients through a web portal that we refer to as the patient knowledge base (PatientKB). Our integration approach utilizes term semantics (i.e. meaning) to enrich the web search and simplify medical terms for patients. In the current implementation, patients have guided, secure and relatively customized access to basic and relevant web information on their diagnoses. Future implementation will attempt to achieve further customization, extensibility and safety features. This paper investigates how ideas presented in an earlier study can be implemented.
Factual claims in late nineteenth century European prehistory and the descent of a modern discipline’s ideology
Authors: Fotiadis Michael
Published: January 2006

Extravagant, fantastic claims about the past are not unique to the late nineteenth century in European prehistory, yet those from that period sound especially curious to twenty-first century archaeological ears and invite reflection: their authors are our direct disciplinary ancestors, yet, when we find fantastic what they took to be sound knowledge, we appear to be of a radically different breed of scholars/subjects. In this article, I explore the nature of the difference, and do so while attempting to ‘re-member’ the presence in our disciplinary past of those ancestors. At issue is not the nineteenth century ideological context that made their fantastic claims appear like solid knowledge to them but the disciplinary ideology that sustains the practice of prehistoric archaeology today, and from the standpoint of which the nineteenth century factual claims are curious. This ideology, I argue, descends from the very nineteenth century scholarship that it now finds replete with fantasies. Demonstration of this requires that I leave aside the familiar techniques of today’s historicism and treat the difference in terms of continuity and transformation of the subject.
Material habits, identity, semeiotic
Authors: Lele Veerendra P.
Published: January 2006

Complementing recent archaeological work on identities, in this article I describe the semeiotic of Charles Sanders Peirce - his general ‘theory of signs’ - and discuss its uses for interpreting human identity through material culture and the artefactual record. Often classified as ‘symbolic anthropology/archaeology’, previous researches have presented a more restricted sense of semeiotic, while fewer scholars have been working through Peirce’s theories directly. Here, I articulate some aspects of Peirce’s semeiotic realism and his pragmatism with his theories regarding semeiosic matter and semeiosic identity. Specifically, Peirce regarded matter as ‘mind hidebound with habits’, and his semeiotic is particularly well-suited for analyzing the obdurate or habitual character of material culture. Based primarily on my ethnographic and archaeological fieldwork in an Irish-speaking region in western Ireland, I explore and apply some of Peirce’s theories to an interpretation of human social identities manifest through such things as prayer beads and field-walls.
Communicating archaeology
Authors: Watkins Joe E.
Published: January 2006

As archaeologists, we are often called upon to discuss our work with various groups that share our interest in human culture and human adaptation, to communicate with those whose heritage we study, or to explain our findings to other ‘stakeholders’ in the archaeological enterprise. As communicators, however, we are less adept at accurately portraying our thoughts to those groups. All too frequently we enter into opportunities to communicate with groups and then bore them with jargon, try to dazzle them with technological brilliance, or lose their attention all together. And, even when we do not confuse them with acronyms, we take it for granted that the words we choose are understood in our intended manner. The following article begins with a few examples of misunderstandings involved in communicating archaeology and then goes beyond these topics to the core of the Western scientific process of naming and categorizing, to the politics of our profession and to the implications of our archaeology on contemporary populations.
A (G→C) transversion in the 3′ UTR of the human ECP (eosinophil cationic protein) gene correlates to the cellular content of ECP
Authors: Jönsson Ulla-Britt , Byström Jonas , Stålenheim Gunnemar , Venge Per
Published: January 2006

Eosinophil cationic protein (ECP) is a cytotoxic protein produced by and secreted from human eosinophil granulocytes. ECP may be involved in the injury of epithelial cells in allergic diseases such as asthma. The objectives were to determine the prevalence of the ECP gene polymorphism 562(G>C) in apparently healthy subjects and subjects with allergy and relate the prevalence to clinical disease and to serum and cellular levels of ECP. The 562(G>C) ECP gene polymorphism was determined by gene sequencing of the ECP gene from DNA prepared from 163 apparently healthy subjects and 151 subjects with allergic and nonallergic asthma or other diseases. ECP was measured by a sensitive radioimmunoassay. A polymorphism was detected at position 562, which mapped to the 3′ untranslated region (UTR) of the gene encoding the ECP (RNase 3). Sixty-nine percent of the population had the 562GG genotype and 4%, the 562CC genotype. The cellular content of ECP in peripheral blood eosinophil granulocytes was significantly lower in cells from subjects with the 562GC (4.6±1.5 μg/106 eosinophils) and 562CC (3.2±0.7 μg/106 eosinophils) genotypes as compared with those with the 562GG genotype (6.0±1.9 μg/106 eosinophils; P<0.001). A close link was found to the 434(G>C) ECP gene polymorphism. Associations between the 562(G>C) polymorphism or haplotypes of the two polymorphisms to allergy were not found. The 562(G>C) polymorphism in the 3′-end of the UTR of the ECP gene may determine the ECP content in human eosinophils, but unlike the 434(G>C) polymorphism, the 562(G>C) polymorphism is not related to allergy
Inverse Relationship between Luteinizing Hormone and Body Mass Index in Polycystic Ovarian Syndrome: Investigation of Hypothalamic and Pituitary Contributions
Authors: Pagán Yanira L. , Srouji Serene S. , Jimenez Yarisie , Emerson Anne , Gill Sabrina , Hall Janet E.
Published: January 2006

Context: Patients with polycystic ovarian syndrome (PCOS) have increased LH relative to FSH, but LH is modified by body mass index (BMI).

Objective: The objective of the study was to determine whether the impact of BMI on neuroendocrine dysregulation in PCOS is mediated at the hypothalamic or pituitary level.

Participants/Interventions/Setting: Twenty-four women with PCOS across a spectrum of BMIs underwent frequent blood sampling, iv administration of GnRH (75 ng/kg), and sc administration of the NAL-GLU GnRH antagonist (5 μg/kg) in the General Clinical Research Center at an academic hospital.

Main Outcome Measures: LH pulse frequency and LH response to submaximal GnRH receptor blockade were used as measures of hypothalamic function; LH response to GnRH was used as a measure of pituitary responsiveness.

Results: BMI was negatively correlated with mean LH, LH/FSH, and LH pulse amplitude. There was no effect of BMI on LH pulse frequency. Percent inhibition of LH was decreased in PCOS, compared with normal women (53.9 ± 1.5 vs. 63.1 ± 4.1, respectively; P < 0.01), suggesting an increase in the amount of endogenous GnRH, but was not influenced by BMI. Pituitary responsiveness to GnRH was inversely correlated with BMI (peak LH, R = −0.475, P < 0.02; and LH area under the curve R = −0.412, P < 0.02).

Conclusions: LH pulse frequency and quantity of GnRH are increased in PCOS, but there is no influence of BMI on either marker of hypothalamic function. The pituitary response to a weight-based dose of GnRH is inversely related to BMI in PCOS. These studies suggest that the effect of BMI on LH is mediated at a pituitary and not a hypothalamic level in PCOS.
Extracellular nucleotide signaling in adult neural stem cells: synergism with growth factor-mediated cellular proliferation
Authors: Mishra Santosh K. , Braun Norbert , Shukla Varsha , Füllgrabe Marc , Schomerus Christof , Korf Horst-Werner , Gachet Christian , Ikehara Yukio , Sévigny Jean , Robson Simon C. , Zimmermann Herbert
Published: January 2006

We have previously shown that the extracellular nucleoside triphosphate-hydrolyzing enzyme NTPDase2 is highly expressed in situ by stem/progenitor cells of the two neurogenic regions of the adult murine brain:the subventricular zone (type B cells) and the dentate gyrus of the hippocampus (residual radial glia). We explored the possibility that adult multipotent neural stem cells express nucleotide receptors and investigated their functional properties in vitro. Neurospheres cultured from the adult mouse SVZ in the presence of epidermal growth factor and fibroblast growth factor 2 expressed the ecto-nucleotidases NTPDase2 and the tissue non-specific isoform of alkaline phosphatase, hydrolyzing extracellular ATP to adenosine. ATP, ADP and, to a lesser extent, UTP evoked rapid Ca2+ transients in neurospheres that were exclusively mediated by the metabotropic P2Y1 and P2Y2 nucleotide receptors. In addition,agonists of these receptors and low concentrations of adenosine augmented cell proliferation in the presence of growth factors. Neurosphere cell proliferation was attenuated after application of the P2Y1-receptor antagonist MRS2179 and in neurospheres from P2Y1-receptor knockout mice. In situ hybridization identified P2Y1-receptor mRNA in clusters of SVZ cells. Our results infer nucleotide receptor-mediated synergism that augments growth factor-mediated cell proliferation. Together with the in situ data, this supports the notion that extracellular nucleotides contribute to the control of adult neurogenesis.
belladonna/(lhx2)is required for neural patterning and midline axon guidance in the zebrafish forebrain
Authors: Seth Anandita , Culverwell James , Walkowicz Mitchell , Toro Sabrina , Rick Jens M. , Neuhauss Stephan C. F. , Varga Zoltan M. , Karlstrom Rolf O.
Published: January 2006

Some of the earliest axon pathways to form in the vertebrate forebrain are established as commissural and retinal axons cross the midline of the diencephalon and telencephalon. To better understand axon guidance in the forebrain, we characterized the zebrafish belladonna (bel)mutation, which disrupts commissural and retinal axon guidance in the forebrain. Using a positional cloning strategy, we determined that the bel locus encodes zebrafish Lhx2, a lim-homeodomain transcription factor expressed in the brain, eye and fin buds. We show that bel(lhx2) function is required for patterning in the ventral forebrain and eye, and that loss of bel function leads to alterations in regulatory gene expression, perturbations in axon guidance factors, and the absence of an optic chiasm and forebrain commissures. Our analysis reveals new roles for lhx2 in midline axon guidance, forebrain patterning and eye morphogenesis.
Synaptic Vesicle Protein 2 Enhances Release Probability at Quiescent Synapses
Authors: Custer Kenneth L. , Austin Naola S. , Sullivan Jane M. , Bajjalieh Sandra M.
Published: January 2006

We report a thorough analysis of neurotransmission in cultured hippocampal neurons lacking synaptic vesicle protein 2 (SV2), a membrane glycoprotein present in all vesicles that undergo regulated secretion. We found that SV2 selectively enhances low-frequency neurotransmission by priming morphologically docked vesicles. Loss of SV2 reduced initial release probability during a train of action potentials but had no effect on steady-state responses. The amount and decay rate of asynchronous release, two measures sensitive to presynaptic calcium concentrations, are not altered in SV2 knock-outs, suggesting that SV2 does not act by modulating presynaptic calcium. Normal neurotransmission could be temporarily recovered by delivering an exhaustive stimulus train. Our results indicate that SV2 primes vesicles in quiescent neurons and that SV2 function can be bypassed by an activity-dependent priming mechanism. We propose that SV2 action modulates synaptic networks by ensuring that low-frequency neurotransmission is faithfully conveyed.
Involvement of the CA3–CA1 Synapse in the Acquisition of Associative Learning in Behaving Mice
Authors: Gruart Agnès , Muñoz María Dolores , Delgado-García José M.
Published: January 2006

One of the brain sites more directly related with learning and memory processes is the hippocampus. We recorded, in conscious mice, the activity-dependent changes taking place at the hippocampal CA3–CA1 synapse during the acquisition, extinction, recall, and reconditioning of an associative task. Mice were classically conditioned to evoke eyelid responses using a trace [conditioned stimuli (CS), tone; unconditioned stimuli (US), shock] paradigm. A single electrical pulse presented to the Schaffer collateral–commissural pathway during the CS–US interval evoked a monosynaptic field EPSP (fEPSP) at ipsilateral CA1 pyramidal cells. The slope of evoked fEPSPs increased across conditioning sessions and decreased during extinction, being linearly related to learning evolution. In contrast, fEPSPs were not modified when evoked in control mice in the absence of a conditioning protocol. Long-term potentiation (LTP) evoked by high-frequency stimulation of Schaffer collaterals prevented acquisition, extinction, recall, or reconditioning, depending on the moment when it was triggered. Learning and memory impairments evoked by LTP induction resulted probably from the functional saturation of the CA3–CA1 synapse, although an additional disturbance of the subsequent information transfer toward postsynaptic circuits cannot be discarded. CGP 39551 [(E)-(±)-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester] (an NMDA antagonist) prevented LTP induction in behaving mice, as well as the acquisition of an eyelid learned response, and the synaptic changes taking place at the CA3–CA1 synapse across conditioning. In conclusion, the responsivity of the CA3–CA1 synapse seems to be modulated during associative learning, and both processes are prevented by experimental LTP or NMDA-receptor inactivation. Our results provide evidence of a relationship between activity-dependent synaptic plasticity and associative learning in behaving mice.
Transition from Reversible to Persistent Binding of CaMKII to Postsynaptic Sites and NR2B
Authors: Bayer K. Ulrich , LeBel Éric , McDonald Greg L. , O’Leary Heather , Schulman Howard , De Koninck Paul
Published: January 2006

Changes in protein–protein interactions and activity states have been proposed to underlie persistent synaptic remodeling that is induced by transient stimuli. Here, we show an unusual stimulus-dependent transition from a short-lived to long-lasting binding between a synaptic receptor and its transducer. Both molecules, the NMDA receptor subunit NR2B and Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII), are strongly implicated in mediating synaptic plasticity. We show that CaMKII reversibly translocates to synaptic sites in response to brief stimuli, but its resident time at the synapse increases after longer stimulation. Thus, CaMKII localization reflects temporal patterns of synaptic stimulation. We have identified two surface regions of CaMKII involved in short-lived and long-term interactions with NR2B. Our results support an initial reversible and Ca2+/CaM-dependent binding at the substrate-binding site (“S-site”). On longer stimulation, a persistent interaction is formed at the T286-binding site (“T-site”), thereby keeping the autoregulatory domain displaced and enabling Ca2+/CaM-independent kinase activity. Such dual modes of interaction were observedin vitroand in HEK cells. In hippocampal neurons, short-term stimulation initiates a reversible translocation, but an active history of stimulation beyond some threshold produces a persistent synaptic localization of CaMKII. This activity-dependent incorporation of CaMKII into postsynaptic sites may play a role in maturation and plasticity of synapses.
A Recurrent Network Mechanism of Time Integration in Perceptual Decisions
Authors: Wong Kong-Fatt , Wang Xiao-Jing
Published: January 2006

Recent physiological studies using behaving monkeys revealed that, in a two-alternative forced-choice visual motion discrimination task, reaction time was correlated with ramping of spike activity of lateral intraparietal cortical neurons. The ramping activity appears to reflect temporal accumulation, on a timescale of hundreds of milliseconds, of sensory evidence before a decision is reached. To elucidate the cellular and circuit basis of such integration times, we developed and investigated a simplified two-variable version of a biophysically realistic cortical network model of decision making. In this model, slow time integration can be achieved robustly if excitatory reverberation is primarily mediated by NMDA receptors; our model with only fast AMPA receptors at recurrent synapses produces decision times that are not comparable with experimental observations. Moreover, we found two distinct modes of network behavior, in which decision computation by winner-take-all competition is instantiated with or without attractor states for working memory. Decision process is closely linked to the local dynamics, in the “decision space” of the system, in the vicinity of an unstable saddle steady state that separates the basins of attraction for the two alternative choices. This picture provides a rigorous and quantitative explanation for the dependence of performance and response time on the degree of task difficulty, and the reason for which reaction times are longer in error trials than in correct trials as observed in the monkey experiment. Our reduced two-variable neural model offers a simple yet biophysically plausible framework for studying perceptual decision making in general.
Prefrontal Set Activity Predicts Rule-Specific Neural Processing during Subsequent Cognitive Performance
Authors: Sakai Katsuyuki , Passingham Richard E.
Published: January 2006

Prefrontal neurons have been shown to represent task rules. Here we show the mechanisms by which the rule-selective activity in the prefrontal cortex influences subsequent cognitive performance based on that rule. Using functional magnetic resonance imaging, we found that the frontopolar cortex interacted with posterior areas differently depending on whether subjects were going to perform a phonological or semantic task. Moreover, we found that the sustained “set” activity in this region predicted the activity that could be recorded in the posterior areas during the performance, as well as the speed of that performance. We argue that the prefrontal set activity does not reflect simple maintenance of the task rules but the process of implementing the rule for subsequent cognitive performance and that this is done through rule-selective interactions with areas involved in execution of the tasks.
Involvement of the AMPA Receptor GluR-C Subunit in Alcohol-Seeking Behavior and Relapse
Authors: Sanchis-Segura Carles , Borchardt Thilo , Vengeliene Valentina , Zghoul Tarek , Bachteler Daniel , Gass Peter , Sprengel Rolf , Spanagel Rainer
Published: January 2006

Craving and relapse are core symptoms of drug addiction and alcoholism. It is suggested that, after chronic drug consumption, long-lasting neuroplastic changes within the glutamatergic system are important determinants of addictive behavior. Here, we show that the AMPA type glutamate receptor plays a crucial role in alcohol craving and relapse. We observed, in two animal models of alcohol craving and relapse, that the AMPA antagonist GYKI 52466 [1-(4-aminophenyl)-4-methyl-7, 8-methylenedioxy-5H-2, 3-benzodiazepine] dose-dependently reduced cue-induced reinstatement of alcohol-seeking behavior and the alcohol deprivation effect. The involvement of the AMPA receptor in these phenomena was further studied using mice deficient for the GluR-C AMPA subunit [GluR-Cknock-out (KO)].GluR-CKOs displayed a blunted, cue-induced reinstatement response and alcohol deprivation effect, when compared with wild-type controls; however, no differences between genotypes could be observed regarding ethanol self-administration under operant or home cage drinking conditions. These results imply a role for GluR-C in alcohol relapse, although this phenotype could also be attributable to a reduction in the total number of AMPA receptors in specific brain areas. In conclusion, AMPA receptors seem to be involved in the neuroplastic changes underlying alcohol seeking behavior and relapse. Thus, AMPA receptors represent a novel therapeutic target in preventing relapse.
Compartmentalized and Signal-Selective Gap Junctional Coupling in the Hearing Cochlea
Authors: Jagger Daniel J. , Forge Andrew
Published: January 2006

Gap junctional intercellular communication (GJIC) plays a major role in cochlear function. Recent evidence suggests that connexin 26 (Cx26) and Cx30 are the major constituent proteins of cochlear gap junction channels, possibly in a unique heteromeric configuration. We investigated the functional and structural properties of native cochlear gap junctions in rats, from birth to the onset of hearing [postnatal day 12 (P12)[. Confocal immunofluorescence revealed increasing Cx26 and Cx30 expression from P0 to P12. Functional GJIC was assessed by coinjection of Lucifer yellow (LY) and Neurobiotin (NBN) during whole-cell recordings in cochlear slices. At P0, there was restricted dye transfer between supporting cells around outer hair cells. Transfer was more extensive between supporting cells around inner hair cells. At P8, there was extensive transfer of both dyes between all supporting cell types. By P12, LY no longer transferred between the supporting cells immediately adjacent to hair cells but still transferred between more peripheral cells. NBN transferred freely, but it did not transfer between inner and outer pillar cells. Freeze fracture further demonstrated decreasing GJIC between inner and outer pillar cells around the onset of hearing. These data are supportive of the appearance of signal-selective gap junctions around the onset of hearing, with specific properties required to support auditory function. Furthermore, they suggest that separate medial and lateral buffering compartments exist in the hearing cochlea, which are individually dedicated to the homeostasis of inner hair cells and outer hair cells.
Medullary Raphe Neurons Facilitate Brown Adipose Tissue Activation
Authors: Nason Malcolm W. , Mason Peggy
Published: January 2006

Recent evidence suggests that neurons in the medullary raphe are critical to the activation of brown adipose tissue (BAT), the major source of nonshivering heat production in the rat. Yet it is unclear which medullary raphe cells participate in cold defense and how participating cells contribute to BAT activation. Therefore, we recorded extracellularly from raphe cells during three thermoregulatory challenges that evoked an increase in BAT temperature in anesthetized rats: central cold, ambient cold, or intracerebroventricular prostaglandin E2(PGE2) injection. Physiologically identified serotonergic (p5HT) cell discharge increased in response to cold or PGE2administration and was positively correlated with BAT temperature. However, none of the 147 physiologically identified non-serotonergic (non-p5HT) cells recorded responded to thermoregulatory challenges that evoked an increase in BAT temperature. To test for modulation of BAT activation by non-p5HT cells that are either excited (ON cells) or inhibited (OFF cells) by noxious cutaneous stimulation, noxious stimuli were applied during evoked BAT temperature increases. Noxious stimulation suppressed BAT activation, suggesting that cells inhibited by noxious stimulation facilitate spinal circuits controlling BAT. To test whether medullary OFF cells modulate BAT activity, the μ-opiate receptor agonist (d-Ala2, N-Me-Phe4, Gly-ol5)-enkephalin (DAMGO) was microinjected into the raphe magnus, a manipulation that selectively activates OFF cells. DAMGO microinjection blocked noxious stimulation-evoked suppression of PGE2-induced BAT temperature increases. Thus, both p5HT and non-p5HT OFF cells in the medullary raphe facilitate BAT activation in response to cold challenge or pyrogen.
Deep mixing in underwater conditions: a laboratory and field investigation
Authors: Van Impe W. F. , Flores R. D. Verástegui
Published: January 2006

The aim of the present paper is to discuss the laboratory and in situ behaviour of an artificially cemented dredged material. An extensive laboratory testing campaign carried out on soft soil specimens, mechanically mixed with different binders, demonstrated that blast furnace cement has a great potential for the stabilisation of such material. In the laboratory the ordinary practice of mechanical mixing by means of a dough mixer was used, whereas in the field a newly developed deep mixing method was implemented for the installation of trial columns (the soft soil improvement technique), making use of high pressure for injecting a cement slurry through nozzles at the mixing level. A column quality control revealed that the improvement level in the field was higher than on samples prepared in the laboratory. Scanning electron microscopic analysis employed to investigate the microstructure of a specimen mixed both in the laboratory and in the field demonstrated the premise that the technological details of the mixing procedure in the field are key parameters and possibly the main cause of the important beneficial differences in strength results.

Cet exposé a pour but d'analyser le comportement en laboratoire et in situ d'une matière draguée et cimentée artificiellement. Une longue série d'essais en laboratoire effectués sur des spécimens de sol tendre mixés par moyen mécanique avec différents agents liants, a montrée que le ciment de haut fourneau a un grand potentiel de stabilisa-tion de cette matière. En laboratoire, un mixage mécanique ordinaire au moyen d'un mixer à pâte a été utilisé alors que sur le terrain, une méthode de mixage profond nouvellement développée a été utilisée pour l'installation de colonnes d'essai (technique SSI), avec injection par buses sous haute pression de boue de ciment au niveau du mixage. Un contrôle de la qualité des colonnes a montré que le degré d'amélioration sur le terrainétait plusélevé que sur leséchantillons préparés en laboratoire. Une analyse au microscopeélectronique à balayage, employée pour trouver la microstructure d'un spécimen mixé à la fois en laboratoire et sur le terrain, a montré que les détails technologiques du procédé de mixage sur le terrain sont des paramètres clé et sont probablement la cause princi-pale des importantes différences au niveau des valeurs de résistance et de leurs avantages.
Stabilisation of expansive clay bed using calcium chloride solution
Authors: Murty V. Ramana , Krishna P. Hari
Published: January 2006

Expansive clays experience cyclic volumetric changes upon moisture fluctuation because of their intrinsic mineralogical behaviour. As these volumetric changes threaten the stability of almost all lightly loaded structures, various remedial techniques have been developed to reduce the damage they cause. Among these measures, chemical stabilisation using multivalent cations is aimed at altering the chemical environment around the clay particles upon which the behaviour of clay depends to a great extent. In the present work, an attempt is made to study the efficacy of calcium chloride (CaCl2), a strong electrolyte, on the plasticity and swell characteristics of an expansive clay bed. One per cent CaCl2solution was applied to the expansive clay bed by ponding and also through bore-holes. The relative influences of lime and calcium chloride on the properties of the clay bed are brought out by using data from a previous study of lime piles on an adjacent site. The plasticity index of the clay bed is decreased by 7–15% and 40–60% with lime and calcium chloride treatments respectively. Similarly, the swell pressure of the clay is decreased by 20–25% and 50–65% respectively. From this study, it is revealed that the modification of clay properties with calcium chloride is several times greater than that for the conventionally used lime.

Les argiles expansives connaissent des changements volumétriques cycliques lors des fluctuations d'humidité en raison de leur comportement minéralogique intrinsèque. Comme ces changements volumétriques menacent la stabilité de presque toutes les structures légèrement chargées, on a développé diverses techniques visant à réduire les dégâts ainsi causés. Parmi ces mesures il faut citer la stabilisation chimique qui utilise des cations multivalents pour changer l'environnement chimique autour des particules d'argile dont dépend, dans une grande mesure, le comportement de l'argile. Dans ce travail, nous essayons d'étudier l'efficacitédu chlorure de calcium (CaCl2), électrolyte puissant, sur la plasticité et les caractéristiques de gonflement d'un lit d'argile expansive. Nous avons appliqué une solution à un pour cent de CaCl2au lit d'argile en accumulant l'eau audessus et aussi en l'injectant par des forages. Nous montrons les influences relatives de la chaux et du chlorure de calcium sur les propriétés du lit d'argile en utilisant les données provenant d'une étude précédente sur des piles de chaux dans un site adjacent. L'indice de plasticité du lit d'argile diminue respectivement de 7 à 15% et de 40 à 60% après les traitements à la chaux et au chlorure de calcium. De même, la pression de gonflement de l'argile diminue de 20 à 25% et de 50 à 65% respectivement. Cette étude montre que la mod-ification des propriétés de l'argile provoquée par le chlorure de calcium est de plusieurs fois supérieure à celle provoquée par la chaux utilisée de manière conventionnelle.
Cultivar Adaptation across Italian Locations in Four Turfgrass Species
Authors: Annicchiarico Paolo , Russi Luigi , Piano Efisio , Veronesi Fabio
Published: January 2006

Crossover genotype × location (GL) interaction may be exploited by site‐specific breeding and cultivar recommendations for distinct subregions. Turf quality and density of 110 elite cultivars belonging to four species [perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb.), and red fescue (Festuca rubra L. subsp. rubra, litoralis, and commutata)] were assessed at five locations scattered across the Italian peninsula and its main islands. The 110 cultivars were evaluated for (i) assessing the extent of GL interaction and its implications on cultivar selection and recommendation; (ii) comparing additive main effects and multiplicative interaction (AMMI) vs. joint regression modeling of GL effects; (iii) verifying the consistency between species of site similarity for GL effects; and (iv) defining test locations for the Italian national evaluation program and for local breeding programs. The trials were arranged in a Group Block Design with three replicates, grouping cultivars within species. Genotype × location interaction occurred for all traits (P < 0.05) except turf density in tall fescue and Kentucky bluegrass. The selected, one‐dimensional AMMI model always outperformed the joint regression model for predictive accuracy as estimated by the mean square value of the relevant GL interaction parameter. Wide crossover GL interaction was observed for turf quality among top‐ranking cultivars of red fescue and Kentucky bluegrass, justifying site‐specific recommendations. Variation of top‐ranking cultivars across sites also occurred for turf density in red fescue and perennial ryegrass. Site similarity for GL effects was largely inconsistent across species. However, specific adaptation either to cooler, wetter sites or warmer, drier sites emerged for cultivars of red fescue, perennial ryegrass, and tall fescue. Site‐specific breeding may be valuable especially for red fescue, exploiting the trend toward specific adaptation of its subspecies.
Effect of Sowing Time on Coriander Performance in a Semiarid Mediterranean Environment
Authors: Carrubba Alessandra , la Torre Raffaele , Saiano Filippo , Alonzo Giuseppe
Published: January 2006

In semiarid environments, time of sowing is one of the most important factors influencing seed yields. For coriander (Coriandrum sativum L.), the most commonly recommended cropping technique is spring sowing (March–April), since the optimum soil temperature for seed germination ranges between 20 and 23°C, and the crop shows a remarkable sensitivity to frost and cold. In many semiarid areas of southern Italy, however, the occurrence of prolonged dry periods in summer and spring does not allow for the scheduling of summer crops without irrigation. However, the generally mild winter temperatures and the typical rainfall distribution, which is mostly concentrated over the winter months, could allow sowing time to be moved to the winter season to take advantage of the winter rainfalls. To evaluate the effect of moving the sowing time of coriander on seed yield and plant performance in semiarid Mediterranean environments, a field trial was performed in 1998–1999, 1999–2000, and 2000–2001 at Sparacia (Cammarata, AG, Sicily). Coriander seeds were sown in rows 50 cm apart every month for 5 mo from December to April. The fruits were harvested from mid‐June to mid‐July. The time from sowing to harvest was greatly dependent on the sowing date; the duration was 193 to 195 d for the December sowings, and 91 to 100 d for the April sowings. In all 3 yr, the most productive sowing time was December, and sowing after this date resulted in lower yields.
Cultivar Weed‐Competitiveness in Aerobic Rice: Heritability, Correlated Traits, and the Potential for Indirect Selection in Weed‐Free Environments
Authors: Zhao D. L. , Atlin G. N. , Bastiaans L. , Spiertz J. H. J.
Published: January 2006

Forty rice (Oryza sativa L.) cultivars and breeding lines used in the International Rice Research Institute (IRRI) upland rice breeding program were evaluated in adjacent weed‐free and weedy trials in aerobic soil conditions during the wet seasons of 2001, 2002, and 2003. The objectives of this study were to investigate genetic variability in weed suppression and yield and to identify traits that could be used as selection criteria for improved weed competitiveness. Correlations among and heritability (H) of agronomic traits and early vigor were estimated in weedy and weed‐free trials. Regression analysis was performed to predict weedy yield and weed biomass. Cultivars differed widely in the growth of weed biomass they permitted (126–296 g m−2) and in yield under competition (0.5–2.5 Mg ha−1). Cultivar yield, duration, biomass, harvest index, height, and vegetative vigor under weed‐free conditions were closely correlated with the same traits measured under weedy conditions. Weedy yield and weed biomass were both moderately heritable (H = 0.55 and 0.38 for means estimated from single‐year, three replicate trial, respectively) and genetically correlated with each other (r = −0.84). Weed‐free yield and vigor at two weeks after seeding (WAS) were moderately heritable (H = 0.68 and 0.38 for means estimated from a single‐year, three replicate trial, respectively) and were highly genetically correlated with weedy yield (r = 1.00 and 0.88, respectively) and weed biomass (r = −0.89 and −0.67, respectively). Vegetative vigor at two WAS and grain yield measured under weed‐free conditions explained a combined 87% of cultivar variation in weedy yield and 40% in weed biomass. Indirect selection on these two traits was predicted to be efficient for improving yield under weed competition and weed‐suppressive ability of aerobic rice.
Quantitative Trait Loci for Root Architecture Traits Correlated with Phosphorus Acquisition in Common Bean
Authors: Beebe Stephen E. , Rojas‐Pierce Marcela , Yan Xiaolong , Blair Matthew W. , Pedraza Fabio , Muñoz Fernando , Tohme Joe , Lynch Jonathan P.
Published: January 2006

Low soil P availability is a primary constraint to common bean (Phaseolus vulgarisL.) production in Latin America and Africa. Substantial genotypic variation in bean adaptation to low phosphorus (LP) availability has been linked with root traits that enhance the efficiency of soil foraging. The objectives of this study were to identify quantitative trait loci (QTLs) for P accumulation and associated root architectural traits, to facilitate genetic improvement and to reveal physiological relationships. Eighty‐six F5.7recombinant inbred lines (RILs) were developed from a cross between G19833, an Andean landrace with high total P accumulation, and DOR 364, a Mesoamerican cultivar with low total P accumulation in LP conditions. A genetic map constructed with restriction fragment length polymorphisms (RFLPs), microsatellites, and PCR‐based markers covering 1703 centimorgans (cM) total genetic distance and all eleven linkage groups (LGs) was used for QTL analysis. Seventy‐one RILs were evaluated in the field at high phosphorus (HP) and LP for P accumulation, total root length (RL), specific RL, and plant dry weight (DW), while all 86 RILs were evaluated in a hydroponic system in the greenhouse for tap, basal, total, and specific RL and plant DW. Phosphorus accumulation in the field correlated with root parameters measured in the greenhouse. A total of 26 individual QTLs were identified for P accumulation and associated root characters using composite interval mapping (CIM) analysis. Phosphorus accumulation QTLs often coincided with those for basal root development, thus, basal roots appear to be important in P acquisition. Independent QTLs were identified for basal and taproot development, and for specific RL. Distinct QTLs for greater specific RL had positive, null and negative effects on P accumulation. Our results confirm the importance of root structure for LP adaptation and highlight the need for a more detailed understanding of root architectural traits for phenotypic as well as marker‐aided selection of more P‐efficient crops.