bluuebunny/crossref_metadata_2025 huggingface dataset:
Benzodiazepine impairment of perirhinal cortical plasticity and recognition memory
Authors: Wan H. , Warburton E. C. , Zhu X. O. , Koder T. J. , Park Y. , Aggleton J. P. , Cho K. , Bashir Z. I. , Brown M. W.
Published: September 2004

Benzodiazepines, including lorazepam, are widely used in human medicine as anxiolytics or sedatives, and at higher doses can produce amnesia. Here we demonstrate that in rats lorazepam impairs both recognition memory and synaptic plastic processes (long‐term depression and long‐term potentiation). Both impairments are produced by actions in perirhinal cortex. The findings thus establish a mechanism by means of which benzodiazepines impair recognition memory. The findings also strengthen the hypotheses that the familiarity discrimination component of recognition memory is dependent on reductions in perirhinal neuronal responses when stimuli are repeated and that these response reductions are due to a plastic mechanism also used in long‐term depression.
Why Subsidise Private Health Insurance?
Authors: Frech H. E. , Hopkins Sandra
Published: September 2004

What are the economic rationales for the public subsidy of private health insurance? Inducing more people to purchase private cover has the potential to create a positive fiscal externality, as it frees up the limited public beds and other public resources for people who cannot afford private health insurance. Investigating this quantitatively, based on short‐run demand estimates, we find that the subsidy cannot be justified on the basis of this externality effect alone. We estimate that the optimal subsidy is actually negative, that is, a tax on private health insurance premiums. On the other hand, the externality does finance some of the costs. We then consider a long‐run dynamic version, consistent with the government's stated rationales for the reforms. In this context, the subsidy might be justified, or at least largely offset, by the fiscal externality. We then discuss other rationales for a subsidy and implementation issues.
A Critique of the Private Health Insurance Regulations
Authors: Vaithianathan Rhema
Published: September 2004

The private health insurance sector is one of the most regulated sectors in Australia. The Private Health Insurance Incentives Scheme, along with community rating, is intended to make private insurance equitable, profitable and popular. We argue that the subsidy to health insurance ought to be a very effective tool for increasing insurance–but it was ineffective because community rating was ineffective. Using data from the Household Expenditure Survey we find that despite community rating rules which prohibit age‐adjusted premiums, young adults paid considerably less for their insurance than older adults. We conclude that insurers circumvented community rating through plan design, screening older consumers into more expensive plans. We also find that the penalty of 2 per cent per year for delaying insurance, introduced as part of the lifetime cover plan, is too low to be effective. We reflect on the New Zealand experience, where a completely deregulated insurance industry continues to be profitable and enjoys similar rates of coverage to those of Australia, and we ask whether Australia too could not benefit from complete deregulation.
Combining Work and Family in Two Welfare State Contexts: A Discourse Analytical Perspective
Authors: Repo Katja
Published: September 2004

This paper describes and compares the way in which British and Finnish mothers of dual‐career families construct discourses on the work and family interplay. Through this comparison, the paper also considers the presence or visibility of larger welfare state frameworks at the level of the discourse of mothers. The paper argues that, despite the many structural and ideological differences between the British and the Finnish welfare states, mothers living in them often construct their daily lives by using similar discursive frameworks. These discourses are, however, contextualized and interpreted differently. This level of contextualization and interpretation of the discourses is argued to be the stage where the structures and gender constructs of welfare states step in.
Family Commitments under Negotiation: Dual Carers in Finland and Italy
Authors: Zechner Minna
Published: September 2004

This paper makes a comparison between Finnish and Italian working dual carers. Dual carers have responsibilities simultaneously at two different fronts. The selected Finnish and Italian samples of carers are doing similar care work in different settings. They negotiate care with a variety of actors and under differing circumstances. A care life story has been constructed for each participant. Then these care life stories have been compared with each other, especially at points where the need for negotiation has been evident, at life's various turning points. There are many individual similarities in negotiations performed in Finland and in Italy. However, their divergent contexts create considerable variation.
Managing the Family: Productivity, Scheduling and the Male Veto
Authors: Baldock John , Hadlow Jan
Published: September 2004

This paper argues that research, analysis and policy innovations focused on how households combine paid work with care responsibilities are driven to too great a degree by preconceptions of “the problem” that do not take sufficient account of how families themselves understand their work and care roles and the choices they are making. The evidence of 246 SOCCARE interviews across five European countries (Finland, France, Italy, Portugal and the UK) is that the variables that are conventionally accepted as having fundamental significance (family‐friendly policies and generous care services, flexible working hours, women's work–life preferences, family type, national labour markets, cultural differences) are less important than is often suggested. More important are time pressures and the idiosyncratic factors that constrain the work and care timetables that families are able to construct. We characterize these as “scheduling problems”. They occupied a large part of the accounts of their lives provided by our respondents and are a primary dimension within which their combinations of paid work and care responsibilities need to be understood. The difficulties our respondents faced in coordinating the work and care activities of their families bear a striking similarity to the problems described in the operations research literature on small businesses. Within the context of these scheduling problems a second important factor emerged: the preferences and behaviour of men who played a critical, though often passive, part in the construction of work and care timetables of the families. We characterize this effect as the “the male veto”.
Has the National Minimum Wage Reduced UK Wage Inequality?
Authors: Dickens Richard , Manning Alan
Published: September 2004

The paper investigates the effect on the wage distribution of the introduction, in April 1999, of the national minimum wage (NMW) in the UK. Because of the structure of UK earnings statistics, it is not straightforward to investigate this and various methods for adjusting the published statistics are discussed. The main conclusions are that the NMW does have a detectable effect on the wage distribution and that compliance with the NMW is widespread but the effect is limited because the NMW has been set at a level such that only 6–7% of workers are directly affected and the NMW has had virtually no effect on the pay of workers who are not directly affected. Furthermore, virtually all the changes occurred within 2 months of the introduction in April 1999 and its effect declined over time from April 1999 to September 2001 as the minimum wage was not uprated in line with the increase in average earnings. The more substantial increase in the NMW in October 2001 partially, but not wholly, restored some of this decline in impact.
That Way Madness Lies: At the Intersection of Philosophy and Clinical Psychology
Authors: Mundale Jennifer
Published: September 2004

Abstract: I argue that philosophical practice is a clinically active and influential endeavor, with both positive (therapeutic) and negative (detrimental) psychological possibilities. Though some have explicitly taken the clinical aspects of philosophy into the therapeutic realm via the new field of philosophical counseling, I am interested in the clinical context of philosophers as philosophers, engaged in standard, philosophical pursuits. In arguing for the clinical implications of philosophical practice I consider the relation between philosophical despair and depression, the cognitive etiology of depression and other clinical disorders, selected DSM‐IV entries, attribution theory, and cognitive therapy.
Keeping a Place for Metaethics: Assessing Elliot's Dismissal of the Subjectivism/Objectivism Debate in Environmental Ethics
Authors: Domsky Darren
Published: September 2004

Abstract: Robert Elliot claims that the metaethical distinction between subjectivism and objectivism is unimportant in environmental ethics. He argues that because a sufficiently sophisticated subjectivist can accommodate all the intrinsic value an objectivist can, even in apparently problematic situations where humans either do not exist or do not have the relevant values, and because metaethical commitments fail to have any normative or motivational impact on rational debate, it makes no difference whether an environmental ethicist is a subjectivist or an objectivist. Elliot's dismissal, however, is unjustified. As it turns out, objectivists argue differently from the way subjectivists do, are motivated differently from the way subjectivists are, and are able to make a greater range of intrinsic value claims than subjectivists are. If Elliot's arguments have any appeal at all, it is only because he blurs the fundamental metaethical distinction in the first place and defends a subjectivism so objectivist that it is almost unrecognizable as subjectivism.
Skeptical Parasitism and the Continuity Argument
Authors: Ribeiro Brian
Published: September 2004

Abstract: Recent literature on skepticism has raised a nearly univocal voice in condemning skeptical argumentation on the grounds that such argumentation necessarily involves our adopting some nonordinary or unnatural perspective. Were this really so, then skeptical conclusions would not speak to us in the way in which skeptics think they do; we would be “insulated” from any such conclusions. I argue that skeptical argumentation need not rely on any nonordinary or unnatural standards. Rather, the skeptic's procedure is to offer a critique from within. Having given my argument for this claim (which I call the Continuity Argument), I consider and respond to two important objections. I conclude that the skeptic has a powerful meta‐argument to be deployed in defending the legitimacy of his skeptical conclusions against the slings and arrows of (those I call) the half‐true theorists.
Trade Unions, Gender and Claims under Irish Employment Equality Legislation
Authors: Quinn Mary
Published: September 2004

This article examines trade union activity in representing claimants at Equality Officer investigations under the Republic of Ireland's Employment Equality Act, 1977. This is set in the context of traditional trade union support for gender segregation in employment and the observation that trade union decision‐making bodies still tend to be heavily male dominated. Use of the Act by trade unions is shown to have been mainly reactive rather than strategic. Evidence is presented that, while some individual union officials actively supported claims, this was not necessarily typical. It is argued that this represented a lost opportunity by trade unions to push the equality agenda forward and is consistent with continuation of the patriarchal trade union tradition. The article concludes by arguing that significant change to this approach is unlikely, given current gendered patterns of trade union governance.
New Routes to the PhD: Cause for Concern?
Authors: Johnston Bill , Murray Rowena
Published: September 2004

Recent developments suggest that the PhD is at a turning point. Professional groups have criticised the so‐called ‘traditional PhD’. New routes to the PhD are proposed by several bodies and endorsed by one funding council. In light of these developments, it is appropriate to ask what the implications are for the PhD and for the academy. A focus group was used to gather student responses to these developments. The findings show qualified support: students agree that the PhD should cater for different careers but challenge what they see as a simplistic channelling of PhD routes. This paper demonstrates apparent consensus on the need for change in the PhD and reveals movement beyond reconceptualisation towards reconstruction. However, we argue that there is cause for concern in the lack of attention paid to student views and the continuing neglect of quality issues in the PhD.
Selecting Undergraduate Students: What can the UK Learn from the American SAT?
Authors: West Anne , Gibbs Rebecca
Published: September 2004

This short paper explores the contribution or otherwise that could be made by using a test akin to the American Scholastic Assessment Test or SAT to select students for undergraduate degrees in the UK. It examines the political context to the debate about the potential value of such a test, before outlining how SAT results in America vary along dimensions related to social background and how American universities have adapted their admissions procedures in response to these differences. From the research examined it cannot be assumed that the introduction of a test such as the SAT would be any more equitable then the current use of public examinations in England. It is suggested that profiling students along the lines used by some American universities may assist with making access ‘fairer’.
Coming full circle? Forging missing links along Nike's integrated production networks
Authors: Rothenberg‐Aalami Jessica
Published: September 2004

Abstract ‘Global’ corporations are being held accountable for conditions at sites of production, formerly the domains of their foreign contractors. This shift was exemplified when consumers in Nike's largest markets began replacing the excitement of the latest pair of Nike shoes with a question: ‘Should I be wearing Nike shoes?’ With existing analytical tools, we cannot comprehensively answer this question. To do so, we need a more complete picture of international production networks, their interrelationships among agents and their geographies. The use of an integrated production network that links consumption and production analyses and place‐based conditions accomplishes this goal. This integrative approach allows for more thorough investigations of firm networks, the regions where they interact, the labour upon which they depend, and the consumers that influence their behaviour. Furthermore, investigating ‘feedback loops’ between these facets provides a means of understanding how reforms along production networks are mediated.
Trust, commitment and team working: the paradox of virtual organizations
Authors: Crossman Alf , Lee‐Kelley Liz
Published: September 2004

Abstract In this article we take an agent‐centred approach to explore the role of trust and commitment in the virtual organization. The findings of a case study in an international information technology consultancy indicate that multiple relationships arising from the alliance‐based structure require clear commitment to enable the development of trust as a basis for longer‐term partnership. Paradoxically, the perceived low level of commitment from the organization does not engender the high level of trust and commitment required from virtual teams to maximize their performance. However, over time and with extended exchanges, the commitment level and form may evolve, thus necessitating a realignment of existing psychological understanding and trust between the actors. If there is general agreement that an upward shift from short‐term to long‐term commitment is beneficial to all, then the virtual arrangement will continue to be effective.
Anatomical substrates for the discriminative stimulus effects of methamphetamine in rats
Authors: Nakajima Akira , Yamada Kiyofumi , He Jue , Zeng Nan , Nitta Atsumi , Nabeshima Toshitaka
Published: September 2004

Methamphetamine is a psychostimulant drug acting on central monoaminergic neurons to produce both acute psychomotor stimulation and long‐lasting behavioral effects including addiction and psychosis. Drug discrimination procedures have been particularly useful in characterizing subjective effects of addictive drugs. In the present study, to identify potential anatomical substrates for the discriminative stimulus effects of methamphetamine, we investigated the drug discrimination‐associated Fos expression in Sprague–Dawley rats trained to discriminate methamphetamine from saline under a two‐lever fixed ratio 20 (FR‐20) schedule of food reinforcement. The rats that fulfilled the criteria for learning the discrimination were anesthetized and perfused 2 h after the drug discrimination test, and Fos immunoreactivity was examined in 15 brain regions. Fos expression in the brains of rats that discriminate methamphetamine from saline was significantly increased in the nucleus accumbens (NAc) and the ventral tegmental area (VTA), but not in other areas including the cerebral cortex, caudate putamen, substantia nigra, hippocampus, amygdala and habenulla, as compared with the expression in control rats that were maintained under the FR‐20 schedule. The present findings suggest a role for the VTA and NAc as possible neuronal substrates in the discriminative stimulus effects of methamphetamine.
1‐trichloromethyl‐1,2,3,4‐tetrahydro‐β‐carboline‐induced apoptosis in the human neuroblastoma cell line SK‐N‐SH
Authors: Akundi Ravi Shankar , Macho Antonio , Muñoz Eduardo , Lieb Klaus , Bringmann Gerhard , Clement Hans‐Willi , Hüll Michael , Fiebich Bernd L.
Published: September 2004

Trichloroethylene, a common industrial solvent and a metabolic precursor of chloral hydrate, occurs widely in the environment. Chloral hydrate, which is also used as a hypnotic, has been found to condense spontaneously with tryptamine, in vivo, to give rise to a highly unpolar 1‐trichloromethyl‐1,2,3,4‐tetrahydro‐β‐carboline (TaClo) that has a structural analogy to the dopaminergic neurotoxin N‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP). Earlier studies have revealed the relative permeability of the molecule through the blood–brain barrier and its ability to induce Parkinson‐like symptoms in rats. In this study, we report that TaClo induces an apoptotic pathway in the human neuroblastoma cell line, SK‐N‐SH, involving the translocation of mitochondrial cytochrome c to the cytosol and activation of caspase 3. TaClo‐induced apoptosis shows considerable differences from that mediated by other Parkinson‐inducing agents such as MPTP, rotenone and manganese. Although it is not clear if the clinically administered dosage of chloral hydrate or the relatively high environmental levels of trichloroethylene could lead to an onset of Parkinson's disease, the spontaneous in vivo formation of TaClo and its pro‐apoptotic properties, as shown in this report, should be considered.
Amphetamine‐evoked gene expression in striatopallidal neurons: regulation by corticostriatal afferents and the ERK/MAPK signaling cascade
Authors: Ferguson Susan M. , Robinson Terry E.
Published: September 2004

The environmental context in which psychostimulant drugs are experienced influences their ability to induce immediate early genes (IEGs) in the striatum. When given in the home cage amphetamine induces IEGs predominately in striatonigral neurons, but when given in a novel test environment amphetamine also induces IEGs in striatopallidal neurons. The source of the striatopetal projections that regulate the ability of amphetamine to differentially engage these two striatofugal circuits has never been described. We report that transection of corticostriatal afferents selectively blocks, whereas enhancement of cortical activity with an ampakine selectively augments, the number of amphetamine‐evoked c‐fos‐positive striatopallidal (but not striatonigral) neurons. In addition, blockade of the extracellular signal‐regulated kinase (ERK)/mitogen‐activated protein kinase (MAPK) signaling cascade preferentially inhibits the number of amphetamine‐evoked c‐fos‐positive striatopallidal neurons. These results suggest that glutamate released from corticostriatal afferents modulates the ability of amphetamine to engage striatopallidal neurons through an ERK/MAPK signaling‐dependent mechanism. We speculate that this may be one mechanism by which environmental context facilitates some forms of drug experience‐dependent plasticity, such as psychomotor sensitization.
U‐box protein carboxyl terminus of Hsc70‐interacting protein (CHIP) mediates poly‐ubiquitylation preferentially on four‐repeat Tau and is involved in neurodegeneration of tauopathy
Authors: Hatakeyama Shigetsugu , Matsumoto Masaki , Kamura Takumi , Murayama Miyuki , Chui Du‐Hua , Planel Emmanuel , Takahashi Ryosuke , Nakayama Keiichi I. , Takashima Akihiko
Published: September 2004

Neurofibrillary tangles (NFTs), which are composed of hyperphosphorylated and ubiquitylated tau, are exhibited at regions where neuronal loss occurs in neurodegenerative diseases; however, the mechanisms of NFT formation remain unknown. Molecular studies of frontotemporal dementia with parkinsonism‐17 demonstrated that increasing the ratio of tau with exon 10 insertion induced fibrillar tau accumulation. Here, we show that carboxyl terminus of Hsc70‐interacting protein (CHIP), a U‐box protein, recognizes the microtubule‐binding repeat region of tau and preferentially ubiquitylates four‐repeat tau compared with three‐repeat tau. Overexpression of CHIP induced the prompt degradation of tau, reduced the formation of detergent‐insoluble tau and inhibited proteasome inhibitor‐induced cell death. NFT bearing neurons in progressive supranuclear palsy, in which four‐repeat tau is a component, showed the accumulation of CHIP. Thus, CHIP is a ubiquitin ligase for four‐repeat tau and maintains neuronal survival by regulating the quality control of tau in neurons.
Role of serotonin2A receptors in the d‐amphetamine‐induced release of dopamine: comparison with previous data on α1b‐adrenergic receptors
Authors: Auclair Agnès , Blanc Gérard , Glowinski Jacques , Tassin Jean‐Pol
Published: September 2004

d‐Amphetamine is known to induce an increase in dopamine release in subcortical structures, thus inducing locomotor hyperactivity in rodents. Previous data have indicated that only 15% of the d‐amphetamine‐induced release of dopamine in the nucleus accumbens is related to locomotor activity and that this ‘functional’ dopamine release is controlled by α1b‐adrenergic receptors located in the prefrontal cortex. We show here that SR46349B (0.5 mg/kg, 30 min before d‐amphetamine), a specific serotonin2A (5‐HT2A) antagonist, can completely block 0.75 mg/kg d‐amphetamine‐induced locomotor activity without decreasing d‐amphetamine‐induced extracellular dopamine levels in the nucleus accumbens. Using the same experimental paradigm as before, i.e. a systemic injection of d‐amphetamine accompanied by a continuous local perfusion of 3 µm d‐amphetamine, we find that SR46349B (0.5 mg/kg) blocks completely the systemic (0.75 mg/kg) d‐amphetamine‐induced functional dopamine release in the nucleus accumbens. Finally, the bilateral injection of SR46349B (500 pmol/side) into the ventral tegmental area blocked both the d‐amphetamine‐induced locomotor activity and functional dopamine release in the nucleus accumbens, whereas bilateral injection of SR46349B into the medial prefrontal cortex was ineffective. We propose that 5‐HT2A and α1b‐adrenergic receptors control a common neural pathway responsible for the release of dopamine in the nucleus accumbens by psychostimulants.
Chimaerins act downstream from neurotrophins in overcoming the inhibition of neurite outgrowth produced by myelin‐associated glycoprotein
Authors: Mizuno Tatsunori , Yamashita Toshihide , Tohyama Masaya
Published: September 2004

Several myelin‐derived proteins are inhibitory cues that contribute to the lack of regeneration of the CNS and inhibit neurite outgrowth from some neurons in vitro. This inhibition is blocked if neurons are exposed to neurotrophins before encountering the inhibitors. Here, we demonstrate that chimaerin, one of the Rho GTPase activating proteins, is transcriptionally up‐regulated after exposure to neurotrophins in post‐natal cerebellar neurons. The expression of α chimaerin in the cerebellum is developmentally correlated with the abolishment of the inhibitory effect of myelin‐associated glycoprotein (MAG). Ectopic expression of α chimaerin in cerebellar neurons results in resistance to MAG in regard to neurite outgrowth. These results suggest that up‐regulated expression of chimaerin counteracts the activation of RhoA, which is a key molecule in transducing inhibitory signals in neurons.
Dopamine transporter‐dependent and ‐independent actions of trace amine β‐phenylethylamine
Authors: Sotnikova Tatyana D. , Budygin Evgeny A. , Jones Sara R. , Dykstra Linda A. , Caron Marc G. , Gainetdinov Raul R.
Published: September 2004

β‐Phenylethylamine (β‐PEA) is an endogenous amine that is found in trace amounts in the brain. It is believed that the locomotor‐stimulating action of β‐PEA, much like amphetamine, depends on its ability to increase extracellular dopamine (DA) concentrations owing to reversal of the direction of dopamine transporter (DAT)‐mediated DA transport. β‐PEA can also bind directly to the recently identified G protein‐coupled receptors, but the physiological significance of this interaction is unclear. To assess the mechanism by which β‐PEA mediates its effects, we compared the neurochemical and behavioral effects of this amine in wild type (WT), heterozygous and ‘null’ DAT mutant mice. In microdialysis studies, β‐PEA, administered either systemically or locally via intrastriatal infusion, produced a pronounced outflow of striatal DA in WT mice whereas no increase was detected in mice lacking the DAT (DAT‐KO mice). Similarly, in fast‐scan voltammetry studies β‐PEA did not alter DA release and clearance rate in striatal slices from DAT‐KO mice. In behavioral studies β‐PEA produced a robust but transient increase in locomotor activity in WT and heterozygous mice. In DAT‐KO mice, whose locomotor activity and stereotypy are increased in a novel environment, β‐PEA (10–100 mg/kg) exerted a potent inhibitory action. At high doses, β‐PEA induced stereotypies in WT and heterozygous mice; some manifestations of stereotypy were also observed in the DAT‐KO mice. These data demonstrate that the DAT is required for the striatal DA‐releasing and hyperlocomotor actions of β‐PEA. The inhibitory action on hyperactivity and certain stereotypies induced by β‐PEA in DAT‐KO mice indicate that targets other than the DAT are responsible for these effects.
MAPK recruitment by β‐amyloid in organotypic hippocampal slice cultures depends on physical state and exposure time
Authors: Bell Karen A. , O'Riordan Kenneth J. , Sweatt J. David , Dineley Kelly T.
Published: September 2004

Elevated β‐amyloid is thought to trigger the onset of Alzheimer's disease. Alzheimer's disease is marked by progressive loss of cognitive function, an early symptom of which is episodic memory deficits. Impairment of episodic memory is linked to hippocampal pathology. We investigated the signal transduction consequences of exposure to nanomolar to low micromolar concentrations of aggregate forms of β‐amyloid in the hippocampus. We found that, in addition to activation of ERK MAPK and its downstream target ribosomal S6 kinase in hippocampal slice cultures following acute exposure to oligomeric β‐amyloid1−42, ERK activation also requires phosphoinositide‐3 kinase activity. These effects were contingent on the α7 subtype of nicotinic acetylcholine receptor. Hippocampal slice cultures treated acutely with oligomeric β‐amyloid1−42 did not exhibit JNK MAPK activation; however, chronic exposure to oligomers or high molecular weight aggregates of β‐amyloid1−42 led to JNK MAPK activation coincident with ERK MAPK down‐regulation. In contrast to the effects of acute application of oligomeric β‐amyloid1−42, nicotine activated ERK MAPK via α7 nicotinic acetylcholine receptors utilizing protein kinase A as an intermediate. In conclusion, we found that both the physical state and duration of exposure to β‐amyloid are determinants of MAPK recruitment in hippocampus. We also found that nicotine and β‐amyloid activate ERK MAPK via α7 nicotinic acetylcholine receptors but use distinct intermediate kinases. These data indicate the existence of differential coupling of α7 to downstream targets depending on the type of ligand that leads to receptor activation.
Inhibition of glutamate‐induced delayed calcium deregulation by 2‐APB and La3+ in cultured cortical neurones
Authors: Chinopoulos Christos , Gerencser Akos A. , Doczi Judit , Fiskum Gary , Adam‐Vizi Vera
Published: September 2004

Exposure of neurones in culture to excitotoxic levels of glutamate results in an initial transient spike in [Ca2+]i followed by a delayed, irreversible [Ca2+]i rise governed by rapid kinetics, with Ca2+ originating from the extracellular medium. The molecular mechanism responsible for the secondary Ca2+ rise is unknown. Here, we report that the delayed Ca2+ entry in cortical neurones is diminished by 2‐aminoethoxydiphenyl borate (2‐APB: IC50 = 62 ± 9 µm) and La3+ (IC50 = 7.2 ± 3 µm), both known to inhibit transient receptor potential (TRP) and store‐operated Ca2+ (SOC) channels. Application of thapsigargin, however, failed to exacerbate the delayed Ca2+ deregulation, arguing against a store depletion event as the stimulus for induction of the secondary [Ca2+]i rise. In addition, these neurones did not exhibit SOC entry. Unexpectedly, application of ryanodine or caffeine significantly inhibited glutamate‐induced delayed Ca2+ deregulation. In basal Ca2+ entry experiments, La3+ and 2‐APB modulated the rapid rise in [Ca2+]i caused by exposure of neurones to Ca2+ after pre‐incubating in a calcium‐free medium. This basal Ca2+ influx was mitigated by extracellular Mg2+ but not aggravated by thapsigargin, ryanodine or caffeine. These results indicate that 2‐APB and La3+ influence non‐store‐operated Ca2+ influx in cortical neurones and that this route of Ca2+ entry is involved in glutamate‐induced delayed Ca2+ deregulation.
Proteomic analysis of native metabotropic glutamate receptor 5 protein complexes reveals novel molecular constituents
Authors: Farr Carol D. , Gafken Philip R. , Norbeck Angela D. , Doneanu Catalin E. , Stapels Martha D. , Barofsky Douglas F. , Minami Manabu , Saugstad Julie A.
Published: September 2004

We used a proteomic approach to identify novel proteins that may regulate metabotropic glutamate receptor 5 (mGluR5) responses by direct or indirect protein interactions. This approach does not rely on the heterologous expression of proteins and offers the advantage of identifying protein interactions in a native environment. The mGluR5 protein was immunoprecipitated from rat brain lysates; co‐immunoprecipitating proteins were analyzed by mass spectrometry and identified peptides were matched to protein databases to determine the correlating parent proteins. This proteomic approach revealed the interaction of mGluR5 with known regulatory proteins, as well as novel proteins that reflect previously unidentified molecular constituents of the mGluR5‐signaling complex. Immunoblot analysis confirmed the interaction of high confidence proteins, such as phosphofurin acidic cluster sorting protein 1, microtubule‐associated protein 2a and dynamin 1, as mGluR5‐interacting proteins. These studies show that a proteomic approach can be used to identify candidate interacting proteins. This approach may be particularly useful for neurobiology applications where distinct protein interactions within a signaling complex can dramatically alter the outcome of the response to neurotransmitter release, or the disruption of normal protein interactions can lead to severe neurological and psychiatric disorders.
A novel constitutively active mutation in the second cytoplasmic loop of metabotropic glutamate receptor
Authors: Yamashita Takahiro , Kai Toshihiro , Terakita Akihisa , Shichida Yoshinori
Published: September 2004

G protein‐coupled receptors have a common structural motif of seven transmembrane α‐helices and are classified into different families showing no sequence similarity. Extensive studies have been conducted on the structure–function relationship in family 1 receptors, but those in other families have not been well studied. In this study, to investigate the molecular basis leading to the G protein activation by metabotropic glutamate receptor (mGluR), the member of family 3, we searched for the amino acid residues responsible for the G protein activation in the second cytoplasmic loop, which was thought to be the main G protein binding region. Analyses of the systematical mutations of Gi/Go‐coupled mGluR8 revealed the presence of a constitutively active mutation in the C‐terminal region of the second loop. The corresponding mutation in the second loop of Gq‐coupled mGluR1 also exhibited high agonist‐independent activity. These results indicate that there is a common constitutive active mutation site regardless of mGluR subtypes, suggesting that the structural change of the junction between the second cytoplasmic loop and helix IV is strongly linked to the formation of the active state.
Evidence for histamine as a transmitter in rat carotid body sensor cells
Authors: Koerner Pia , Hesslinger Christian , Schaefermeyer Agnes , Prinz Christian , Gratzl Manfred
Published: September 2004

Carotid bodies harboring sensor cells for oxygen have a strategic location at the bifurcation of the carotid artery, which supplies the brain. Upon arterial hypoxia they transmit signals to the respiratory center, which increases the frequency of breathing. Dopamine is considered as the predominant transmitter of the rat carotid body sensor cells. Here we show that the rat carotid body sensor cells are the first cell type known to have the complete apparatus to synthesize, store and release both dopamine and histamine. The tyrosine hydroxylase positive dopaminergic sensor cells of juvenile rats express the histamine biosynthesis enzyme, histidine decarboxylase. Moreover, the sensor cells have not only vesicular monoamine transporter 1 (VMAT1) transporting catecholamines but also VMAT2, which is highly specific for histamine. Additionally, we found that these cells possess components of the neuroendocrine exocytosis apparatus, synaptosome‐associated protein of 25 kDa (SNAP 25) and syntaxin1. The amount of histamine determined in the rat carotid body (164 pmol/carotid body) is more than 10‐fold higher compared with that of dopamine. As a main effect, hypoxia significantly increased histamine release from isolated rat carotid bodies as it has been shown for dopamine. Finally, RT‐PCR experiments indicate the presence of histamine receptors H1, H2 and H3 in the carotid body. Our data suggest that histamine is synthesized, stored and released upon hypoxia by dopaminergic sensor cells of the rat carotid body.
The reproductive biology of the White‐necked PicathartesPicathartes gymnocephalus
Authors: Thompson Hazell Shokellu
Published: September 2004

The reproductive biology of the White‐necked PicathartesPicathartes gymnocephalus, a threatened species endemic to the Upper Guinea rainforest of West Africa, was studied in Sierra Leone from 1990 to 1996. The modal clutch size was two (mean 1.92) eggs. Incubation averaged 20 days and the nestling period 25 days. Nesting success (probability of eggs laid surviving to fledge) was 22.9%. Only 0.44 chicks fledged per nesting pair. The main known causes of nest mortality were predation and infanticide. Nestlings fledged when almost 30% smaller than adult size. A life‐table indicates that populations in Sierra Leone could be declining slowly. Alternatively, White‐necked Picathartes could be very long‐lived (annual adult survival could be greater than 90%), in which case populations would be self‐sustaining.
Influence of nest‐site and individual quality on breeding performance in Merlins Falco columbarius
Authors: Espie Richard H. M. , James P. C. , Oliphant L. W. , Warkentin I. G. , Lieske D. J.
Published: September 2004

We examined the effects of nest‐site quality and bird quality on breeding performance in male and female Merlins Falco columbarius from a long‐term study in Saskatoon, Saskatchewan. In addition, we tested whether nest‐site quality was associated with survival, as well as lifetime reproductive success (LRS). For females, nest‐site quality had little influence on any of the measures of breeding performance or survival. Even so, when females switched nest‐sites, they tended to move to better ones. Hatch date was repeatable for the same females occupying different nest‐sites but not for the same sites occupied by different females. Among males, birds surviving past each age category tended to occupy nest‐sites of higher quality, and LRS was positively correlated with nest‐site quality. The relationship between nest‐site quality and LRS was heavily influenced by the poorest nest‐sites. When males switched nest‐sites, they too tended to move to ones of higher quality. In addition, chick hatch date was repeatable neither for the same males occupying different sites nor for the same sites occupied by different males. As with most other raptors, male Merlins provide most of the food for the pair and their young during the breeding season, and differences in nest‐site quality may have affected the effort needed by males to secure food. Female Merlins, however, appear still to have considerable control over the timing of breeding.
Environmental heterogeneity, spatial segregation of prey, and the utilization of southwest Atlantic mudflats by migratory shorebirds
Authors: Ribeiro Pablo D. , Iribarne Oscar O. , Navarro Diego , Jaureguy Luciano
Published: September 2004

We studied the relationships between the habitat use of migratory shorebirds and the spatial distributions of the Southwestern Atlantic Fiddler Crab Uca uruguayensis, polychaetes, sediment characteristics and tidal levels in the Río de La Plata estuary, Argentina, where U. uruguayensis is one of the most important intertidal species. Crabs have a well‐defined patchy distribution that is segregated spatially from that of polychaetes. Crab density on the surface varied across the tidal cycle, reaching maximum values during low tide. Polychaete density decreased with depth but showed no change through the tidal cycle; however, given that sediment penetrability did change during the same period, their availability to probing shorebirds is expected to change. Habitat use by shorebirds followed the spatial distribution of prey; shorebirds that foraged on polychaetes (White‐rumped Sandpiper Calidris fuscicollis, Two‐banded Plover Charadrius falklandicus and Hudsonian Godwit Limosa haemastica) focused their attention on the areas with the highest densities of polychaetes, whereas species that preyed mostly on crabs (Ruddy Turnstone Arenaria interpres, Whimbrel Numenius phaeopus and Grey Plover Pluvialis squatarola) predominantly used areas with crabs. This segregation occurred particularly during low tide, a period in which polychaetes became fully available. Results show that the spatial and temporal heterogeneity of mudflats in relation to the types and availability of prey has a strong effect on shorebird habitat use.
Predicting the effects of marine climate change on the invertebrate prey of the birds of rocky shores
Authors: Kendall Michael A. , Burrows Michael T. , Southward Alan J. , Hawkins Stephen J.
Published: September 2004

By the end of the 21st century models of climate change predict that the air temperature over most of the British Isles will increase by between 2 and 3 °C and sea‐level will rise by 40–50 cm. Over that period it will become windier and mean wave height will increase, as will the frequency of storms. These changes in climate and weather will impact the intertidal zone of the UK and will cause distribution changes in many of the common invertebrate species that live there. Where these changes are severe they may well impact on patterns of distribution of ducks and wading birds. In the British Isles a number of organisms live close to their geographical limits of distribution. Some of these species might be expected to extend their range as climatic restraints are relaxed. Species currently limited by cool summers or winter cold will move northwards. In most cases the effects on the distribution of waterbirds will be small. For example, the replacement of the Northern Limpet Patella vulgata by the Southern Limpet P. depressa is unlikely to adversely affect Eurasian Oystercatchers Haematopus ostralegus. Of wider concern is the possibility that as climate warms the abundance and productivity of brown algae will decrease. This is likely to have two significant effects for waders. First, it would represent a loss of potentially rich feeding grounds for species such as Ruddy Turnstone Arenaria interpres that feed on small easily desiccated invertebrates living on or below the seaweed. Secondly, as algae die or are broken away the resulting debris is exported to sediment habitats where it considerably boosts the in situ production of bacteria at the base of the food web. An increase in sea‐level will only have a major impact on the extent of rocky shore invertebrate communities where shore topography prevents the upward migration of the biota. Where a seawall limits shores, for example, biological production will be curtailed as the area available for colonization decreases. Increases in the size of waves and the frequency of storms will mimic increasing exposure and there will be a significant reduction in algal production in areas that are affected.
Migrating shorebirds as integrative sentinels of global environmental change
Authors: Piersma Theunis , Lindström Åke
Published: September 2004

Many shorebirds travel over large sections of the globe during the course of their annual cycle and use habitats in many different biomes and climate zones. Increasing knowledge of the factors driving variations in shorebird numbers, phenotype and behaviour may allow shorebirds to serve as ‘integrative sentinels’ of global environmental change. On the basis of numbers, timing of migration, plumage status and body mass, shorebirds could indicate whether ecological and climate systems are generally intact and stable at hemispheric scales, or whether parts of these systems might be changing. To develop this concept, we briefly review the worldwide shorebird migration systems before examining how local weather and global climatic features affect several performance measures of long‐distance migrants. What do variations in numbers, phenotype and behaviour tell us about the dependence of shorebirds on weather and climate? How does data on migrating shorebirds integrate global environmental information? Documenting the dependencies between the population processes of shorebirds and global environmental features may be an important step towards assessing the likely effects of projected climate change. In the meantime we can develop the use of aspects of shorebird life histories on large spatial and temporal scales to assay global environmental change.
The recent declines of farmland bird populations in Britain: an appraisal of causal factors and conservation actions
Authors: Newton Ian
Published: September 2004

In this paper, the main aspects of agricultural intensification that have led to population declines in farmland birds over the past 50 years are reviewed, together with the current state of knowledge, and the effects of recent conservation actions. For each of 30 declining species, attention is focused on: (1) the external causes of population declines, (2) the demographic mechanisms and (3) experimental tests of proposed external causal factors, together with the outcome of (4) specific conservation measures and (5) agri‐environment schemes. Although each species has responded individually to particular aspects of agricultural change, certain groups of species share common causal factors. For example, declines in the population levels of seed‐eating birds have been driven primarily by herbicide use and the switch from spring‐sown to autumn‐sown cereals, both of which have massively reduced the food supplies of these birds. Their population declines have been associated with reduced survival rates and, in some species, also with reduced reproductive rates. In waders of damp grassland, population declines have been driven mainly by land drainage and the associated intensification of grassland management. This has led to reduced reproductive success, as a result of lowered food availability, together with increased disturbance and trampling by farm stock, and in some localities increased nest predation. The external causal factors of population decline are known (with varying degrees of certainty) for all 30 species considered, and the demographic causal factors are known (again with varying degrees of certainty) for 24 such species. In at least 19 species, proposed causal factors have been tested and confirmed by experiment or by local conservation action, and 12 species have been shown to benefit (in terms of locally increased breeding density) from options available in one or more agri‐environment schemes. Four aspects of agricultural change have been the main drivers of bird population declines, each affecting a wide range of species, namely: (1) weed‐control, mainly through herbicide use; (2) the change from spring‐sown to autumn‐sown cereal varieties, and the associated earlier ploughing of stubbles and earlier crop growth; (3) land drainage and associated intensification of grassland management; and (4) increased stocking densities, mainly of cattle in the lowlands and sheep in the uplands. These changes have reduced the amounts of habitat and/or food available to many species. Other changes, such as the removal of hedgerows and ‘rough patches’, have affected smaller numbers of species, as have changes in the timings of cultivations and harvests. Although at least eight species have shown recent increases in their national population levels, many others seem set to continue declining, or to remain at a much reduced level, unless some relevant aspect of agricultural practice is changed.
Real‐time Studies of the Pivot Bearings in the NEDO Gyro PI‐710 Centrifugal Blood Pump
Authors: Asai Toshimasa , Watanabe Kuniyoshi , Ito Seiichi , Tsujimura Shinichi , Motomura Tadashi , Shinohara Toshiyuki , Glueck Julia A. , Nosé Yukihiko
Published: September 2004

Abstract: The NEDO Gyro PI‐710 centrifugal pump (Gyro PI‐710 pump) incorporates a double pivot bearing system of which the male pivot and female bearings are fabricated from Al2O3 ceramic and ultrahigh molecular weight polyethylene. The top female bearing is a critical component because the impeller is levitated by hydraulic force and is maintained in the top contact position. A long‐term in vitro examination of the pivot bearings was conducted using a biventricular assist model. In 7 animal experiments, the depth change of the top female bearing was examined. Animal experiments up to 90 days revealed that there was no noticeable depth increase in the top female bearing. According to the in vitro study, the life of the pivot bearings of the left and right pump was estimated to be approximately 3 and 7 years, respectively. Further improvement of  this  pivot  bearing  system  is  currently  underway.