bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dietary self‐selection behaviour by the adults of the aphidophagous ladybeetle Harmonia axyridis (Coleoptera: Coccinellidae)
Authors: Soares António Onofre , Coderre Daniel , Schanderl Henrique 
Published: April 2004

Summary

Harmonia axyridis is a generalist predator with a high range of accepted prey. Prey differ in nutritive contents, energetic values and cost associated with their capture and ingestion. As a result of selection pressures, animals will tend to hunt for their prey efficiently. In this paper we evaluated the suitability of Myzus persicae and Aphis fabae to the adults of the aulica phenotype of H. axyridis, their feeding preferences and the impact of mixed diets on their fitness. Feeding preference of predators was evaluated through their response to different relative abundance of prey.
Under a single diet regime, the adults of the aulica phenotype fed on more individuals M. persicae than A. fabae but consumed less biomass from the former. None of those prey affect relative growth rate and reproductive capacity of the ladybeetles.
Males and females present different types of response to three levels of different relative abundance of prey. While males show a constant feeding preference for M. persicae, females did not show a feeding preference (i.e. null switching response). Under a mixed diet regime, adults’ voracity gradually increased as the proportion of M. persicae increased, but biomass consumed and relative growth rate was not affected. On the other hand, fecundity and fertility increased.
Our results suggest that H. axyridis present self‐selection behaviour because they agree with the basic criteria of Waldbauer and Friedman's self‐selection, i.e. (i) the animal's choice of food or nutrients is non‐random, and (ii) the coccinellid benefits from self‐selecting.
Investigating species co‐occurrence patterns when species are detected imperfectly
Authors: MacKenzie Darryl I. , Bailey Larissa L. , Nichols James. D. 
Published: April 2004

Summary

Over the last 30 years there has been a great deal of interest in investigating patterns of species co‐occurrence across a number of locations, which has led to the development of numerous methods to determine whether there is evidence that a particular pattern may not have occurred by random chance.
A key aspect that seems to have been largely overlooked is the possibility that species may not always be detected at a location when present, which leads to ‘false absences’ in a species presence/absence matrix that may cause incorrect inferences to be made about co‐occurrence patterns. Furthermore, many of the published methods for investigating patterns of species co‐occurrence do not account for potential differences in the site characteristics that may partially (at least) explain non‐random patterns (e.g. due to species having similar/different habitat preferences).
Here we present a statistical method for modelling co‐occurrence patterns between species while accounting for imperfect detection and site characteristics. This method requires that multiple presence/absence surveys for the species be conducted over a reasonably short period of time at most sites. The method yields unbiased estimates of probabilities of occurrence, and is practical when the number of species is small (< 4).
To illustrate the method we consider data collected on two terrestrial salamander species, Plethodon jordani and members of the Plethodon glutinosus complex, collected in the Great Smoky Mountains National Park, USA. We find no evidence that the species do not occur independently at sites once site elevation has been allowed for, although we find some evidence of a statistical interaction between species in terms of detectability that we suggest may be due to changes in relative abundances.
Absence of costs of foraging excursions in relation to limpet aggregation
Authors: Coleman R. A. , Underwood A. J. , Chapman M. G. 
Published: April 2004

SummaryAnimal aggregation has been well studied, with many proximate and ultimate models proposed. Many of the proximate models have relied on cost–benefit arguments, but frequently aspects of cost have been inferred in relation to position in group. An expected cost to an animal that rests in aggregations, but departs to forage, is that being in the centre of a group may impede foraging opportunities, in that ‘inner’ animals cannot leave to forage until outer animals have done so.Experiments with a limpetCellana tramoserica, on a rocky shore in New South Wales, Australia, showed that central limpets remain central more often than would be expected by chance. In respect of costs due to access to foraging, we show that there is no effect of position (central vs. outer) in timing of foraging excursions or of feeding‐rate. We also show that an aggregated distribution ofC. tramosericaat rest does not translate into an aggregated distribution of foraging animals.We propose that aggregations ofC. tramosericaare probably a function of how the group reassembles after foraging and is much dependent on processes happening at a small spatial scale. It is highly probable that assumptions about the effects of limpet aggregation on rocky shore ecology (i.e. in influencing patchiness of algae) may be premature.
Scales and Sales: Changing Social and Spatial Fish Trading Networks in the Siiphandone Fishery, Lao PDR
Authors: Bush Simon R. 
Published: April 2004

AbstractThe Siiphandone wetland in Khong district, Champasak province, Lao PDR, is one of the most important fisheries in the Mekong River basin. The resource, situated along the Laos‐Cambodia border, supports the livelihoods of around 65,000 inhabitants, mainly semi‐subsistence rice farmers or fishers. In January 2000, the provincial authority was given a special dispensation by the Lao government to allow the importation of Cambodian fish through Khong district, for export to Thailand. Previously, in large part due to the government's policy of food self‐sufficiency, the export of Lao fish was illegal. This paper examines how the implementation of this law has influenced existing legal and illegal trade networks from the Siiphandone fishery by comparing the findings of two studies, one conducted before and the other after the change in the law. In doing so, the transition of the fishery from a local, food‐important resource to an increasingly regional, market‐oriented resource is examined. Conclusions are drawn as to the impact this change has had on the livelihoods of fishers and traders involved in the fishery.
Positionality and Praxis: Fieldwork Experiences in Rural India
Authors: Chacko Elizabeth 
Published: April 2004

AbstractThis paper provides a reflexive account of conducting fieldwork as a graduate student in the Sunderban area of West Bengal state, India, in the mid‐1990s. Reflecting on my personal experiences of research in a setting that was simultaneously familiar and foreign, I use frames of positionality to understand the impact of explicit and implied power structures on the research process, the relationships between the researcher and those researched, and the transfer of knowledge. This paper argues that the multiple subject positions and identities of both scholar and subjects as presented in the field vary with setting, and that these positionalities affect access to informants, the tenor and outcomes of encounters, and knowledge production. While self‐reflexivity is endorsed as a strategy for critically informed research, active measures such as openness about the agenda and activities undertaken, self‐disclosure, making conscious accommodations for the research subject's work schedule and time constraints, mutual sharing of information, and explicit recognition of the research subjects' expertise through lived experiences are proposed as strategies for equalising the power balance between scholar and subject.
Changes in the Indonesian Clothing Industry: Trade and Regulation
Authors: Hassler Markus 
Published: April 2004

AbstractPolicy frameworks at national and international levels have significant influence on the growth performance and industrialisation of developing economies. This paper aims to explore the influence of such regulatory policy frameworks on the development of the Indonesian clothing industry since the mid‐1980s based on an analysis of national clothing trade statistics provided by the Indonesian Central Bureau of Statistics. Although the Indonesian policy framework had a general export‐orientation, protectionist measures for the domestic market proved to be important in facilitating the growth of the Indonesian clothing industry. This paper also shows how the existing international clothing trade regulatory framework of the Multi‐Fibre Arrangement (MFA) influenced the integration of Indonesian clothing firms into global production and trade networks. Finally, the future policy changes and potential impacts for Indonesian clothing firms are discussed.
The Effects of Annual Harvesting on the Subsequent Phytomass and Species Composition of Grassland and Fernland: A Hong Kong Case
Authors: Hill R.D. , Peart M.R. , Dong‐Sheng Guan 
Published: April 2004

AbstractAnthropogenic grasslands mixed with fern and shrubland, on scales from metres to kilometres, are widespread in tropical Southeast Asia, and especially in southern China and adjoining regions where harvesting for domestic fuel is a major factor in their maintenance. Baseline surveys in grassland and fernland in 1989–90 and resurveys in 2001 of three 6 × 20 m plots in Wong Chuk Yuen, Hong Kong, showed substantial change in species composition and total aboveground phytomass as a result of annual harvesting, with more pronounced change in the fernland.Under harvesting pressure, the species composition of the grassland changed considerably, though the proportions of the various life‐forms did not. Ischaemum spp. and Miscanthus floridulus increased whereas Themeda gigantea died out while the proportion of other grass species remained much the same. Under the same regime the species composition and life‐forms of the fernland changed markedly. The proportion of Dicranopteris fern dropped substantially, though still comprising a third of the phytomass by 2001. The shrub Melastoma survived harvesting. A firebreak cut in the fernland became grassy under annual harvesting and remained grassy six years after cutting ceased. The annual harvests from the growth‐years 1991–2000 showed a substantial though variable increase in total phytomass. Analyses relating harvested phytomass with various climatic parameters showed no significant correlations. Some possible reasons for this are suggested. Although annual harvesting was clearly sustainable over the ten years of observation, the question of continued sustainability on sites harvested for centuries, the situation in much of southern China and parts of upland mainland Southeast Asia, remains unresolved.
Identifying Optimum Locations for Tropical Testing of United States Army Materiel and Systems
Authors: King W. Chris , Palka Eugene J. , Harmon Russell S. 
Published: April 2004

AbstractThis paper is an example of applied military geography focusing on a particular problem arising from the Panama Canal Treaty of 1977. One of the provisions of the treaty required the United States (US) military to completely withdraw from and relinquish its military and government facilities to the Republic of Panama prior to midnight on 31 December 1999. In so doing, the US army turned over to the Panama government all of its military bases, some of which had been used since World War I to test materiel, equipment and systems within a tropical environment. Given its global mission and responsibilities, the US army has a well‐established practice of testing its materiel, equipment and systems throughout the entire range of potential operating environments. The US experience in the Pacific in World War II and in Southeast Asia during the Vietnam War clearly demonstrated the need to test the performance of new equipment under the harsh conditions found in tropical jungles. Furthermore, since 1960, nearly 75 per cent of all international and internal armed conflicts have been in countries that are totally or partially in the tropics. This paper presents the findings of a scientific panel that was organised to propose a new location for testing US army materiel and systems within a tropical environment. Rather than simply choosing a location analogous to Panama, the panel sought to develop a methodology that could be employed for site selection based on any set of environmental criteria. This study is a classical locational analysis and reconfirms the integrative nature of geography and its utility for solving complex problems that cut across disciplinary boundaries.
Modulation of calcium/calmodulin kinase‐II provides partial neuroprotection against beta‐amyloid peptide toxicity
Authors: Lin Kim‐Fung , Chang Raymond Chuen‐Chung , Suen Ka‐Chun , So Kwok‐Fai , Hugon Jacques 
Published: April 2004

AbstractBeta‐amyloid (Aβ) peptide‐induced neurotoxicity has been implicated in the pathogenesis of Alzheimer's disease (AD). The exact mechanism by which Aβ peptides trigger neuronal death is not well defined and may be related to an abrupt increase in intracellular calcium, leading to the activation of many pro‐apoptotic pathways. While modulation of intracellular calcium increase receives much attention for pharmaceutical intervention, Ca2+‐mediated pro‐apoptotic signalling pathways have not been systematically studied. We have reported our study on the roles of calcium/calmodulin‐dependent protein kinase II (CaMKII) in Aβ peptide neurotoxicity. By treating the primary cortical neurons exposed to Aβ peptides (Aβ25−35 and Aβ1−42) with two selective CaMKII inhibitors, autocamtide‐related inhibitory peptide (AIP) and KN93, Aβ peptide neurotoxicity was significantly reduced. Release of LDH and DNA fragmentation/condensation (by DAPI staining) in neurons exposed to Aβ peptides were significantly decreased in the presence of AIP and KN93. While these inhibitors significantly attenuated Aβ peptide‐triggered activation of caspase‐2 and caspase‐3, and AIP significantly decreased the degree of tau phosphorylation of the Aβ peptide‐treated neurons at early time, they could elicit partial neuroprotection only. Pharmacological inhibitor targeting calmodulin, W7, did not provide neuroprotection. Morphine, which activates CaMKII via µ receptors, augments Aβ‐induced LDH release, caspase‐2 and caspase‐3 activities and neuronal apoptosis. Taken together, although CaMKII plays a role in Aβ peptide neurotoxicity, pharmacological inhibition cannot afford complete neuroprotection.
Environmental enrichment reverses learning impairment in the Morris water maze after focal cerebral ischemia in rats
Authors: Dahlqvist Per , Rönnbäck Annica , Bergström Sven‐Anders , Söderström Ingegerd , Olsson Tommy 
Published: April 2004

AbstractCognitive impairment is common after ischemic stroke. In rodent stroke models using occlusion of the middle cerebral artery (MCA) this is reflected by impaired spatial memory associated with the size of the ischemic lesion. Housing in an enriched environment enhances brain plasticity and improves recovery of sensorimotor functions after experimental stroke in rats. In this study we report that postischemic housing in an enriched environment also attenuates the long‐term spatial memory impairment after MCA occlusion and extinguishes the association between spatial memory and infarct volume. An enriched environment did not significantly alter the expression of selected neuronal plasticity‐associated genes 1 month after MCA occlusion, indicating that most of the adaptive changes induced by an enriched environment have already occurred at this time point. We conclude that the attenuated memory impairment induced by environmental enrichment after MCA occlusion provides a useful model for further studies on the neurobiological mechanisms of recovery of cognitive functions after ischemic stroke.
Neuronal connexin36 association with zonula occludens‐1 protein (ZO‐1) in mouse brain and interaction with the first PDZ domain of ZO‐1
Authors: Li Xinbo , Olson Carl , Lu Shijun , Kamasawa Naomi , Yasumura Thomas , Rash John E. , Nagy James I. 
Published: April 2004

AbstractAmong the 20 members in the connexin family of gap junction proteins, only connexin36 (Cx36) is firmly established to be expressed in neurons and to form electrical synapses at widely distributed interneuronal gap junctions in mammalian brain. Several connexins have recently been reported to interact with the PDZ domain‐containing protein zonula occludens‐1 (ZO‐1), which was originally considered to be associated only with tight junctions, but has recently been reported to associate with other structures including gap junctions in various cell types. Based on the presence of sequence corresponding to a putative PDZ binding motif in Cx36, we investigated anatomical relationships and molecular association of Cx36 with ZO‐1. By immunofluorescence, punctate Cx36/ZO‐1 colocalization was observed throughout the central nervous system of wild‐type mice, whereas labelling for Cx36 was absent in Cx36 knockout mice, confirming the specificity of the anti‐Cx36 antibodies employed. By freeze‐fracture replica immunogold labelling, Cx36 and ZO‐1 in brain were found colocalized within individual ultrastructurally identified gap junction plaques, although some plaques contained only Cx36 whereas others contained only ZO‐1. Cx36 from mouse brain and Cx36‐transfected HeLa cells was found to coimmunoprecipitate with ZO‐1. Unlike other connexins that bind the second of the three PDZ domains in ZO‐1, glutathione S‐transferase‐PDZ pull‐down and mutational analyses indicated Cx36 interaction with the first PDZ domain of ZO‐1, which required at most the presence of the four c‐terminus amino acids of Cx36. These results demonstrating a Cx36/ZO‐1 association suggest a regulatory and/or scaffolding role of ZO‐1 at gap junctions that form electrical synapses between neurons in mammalian brain.
Glial cell line‐derived neurotrophic factor (GDNF) from adult rat tooth serves a distinct population of large‐sized trigeminal neurons
Authors: Kvinnsland Inger Hals , Luukko Keijo , Fristad Inge , Kettunen Päivi , Jackson Douglass L. , Fjeld Karianne , Von Bartheld Christopher S. , Byers Margaret R. 
Published: April 2004

AbstractGlial cell line‐derived neurotrophic factor (GDNF) mediates trophic effects for specific classes of sensory neurons. The adult tooth pulp is a well‐defined target of sensory trigeminal innervation. Here we investigated potential roles of GDNF in the regulation of adult trigeminal neurons and the dental pulp nerve supply of the rat maxillary first molar. Western blot analysis and radioactive35S‐UTPin situhybridization revealed that GDNF in the dental pulp and its mRNAs were localized withNgfin the coronal pulp periphery, in particular in the highly innervated subodontoblast layer. Retrograde neuronal transport of iodinated GDNF and Fluorogold (FG) from the dental pulp indicated that GDNF was transported in about one third of all the trigeminal dental neurons. Of the GDNF‐labelled neurons, nearly all (97%) were large‐sized (≥35 µm in diameter). Analysis of FG‐labelled neurons revealed that, of the trigeminal neurons supporting the adult dental pulp, ≈ 20% were small‐sized, lacked isolectin B4 binding and did not transport GDNF. Of the large‐sized dental trigeminal neurons ≈ 40% transported GDNF. About 90% of the GDNF‐accumulating neurons were negative for the high‐temperature nociceptive marker VRL‐1. Our results show that a subclass of large adult trigeminal neurons are potentially dependent on dental pulp‐derived GDNF while small dental trigeminal neurons seems not to require GDNF. This suggests that GDNF may function as a neurotrophic factor for subsets of nerves in the tooth, which apparently mediate mechanosensitive stimuli. As in dorsal root ganglia both small‐ and large‐sized neurons are known to be GDNF‐dependent; these data provide molecular evidence that the sensory supply in the adult tooth differs, in some aspects, from the cutaneous sensory system.
Involvement of the sigma1 receptor in the modulation of dopaminergic transmission by amantadine
Authors: Peeters Magali , Romieu Pascal , Maurice Tangui , Su Tsung‐Ping , Maloteaux Jean‐Marie , Hermans Emmanuel 
Published: April 2004

AbstractPharmacological effects of amantadine on dopaminergic transmission are proposed to result from an uncompetitive antagonism at glutamate N‐methyl‐d‐aspartate (NMDA) receptors. However, our previous studies examining amantadine‐mediated dopamine receptor regulation in the rat striatum revealed a discrepancy from a direct interference with glutamate transmission. Preliminary in vitro binding data from the literature suggested the interaction of amantadine with the sigma1 receptor. Therefore, we have now further characterized the pharmacological properties of amantadine and memantine at this receptor and investigated its involvement in the modulation of striatal dopaminergic transmission. Our binding studies using [3H]‐(+)SKF‐10,047 indicated that amantadine and memantine behave as ligands of the sigma1 receptor in rat forebrain homogenates (Ki values of 7.44 ± 0.82 and 2.60 ± 0.62 µm, respectively). In NG108‐15 neuroblastoma cells, both drugs (amantadine (100 µm) and memantine (10 µm)) potentiated the bradykinin‐induced mobilization of intracellular Ca2+, mimicking the effect of the sigma1 receptor agonist PRE‐084 (1 µm). Finally, we previously showed that in striatal membranes from amantadine‐treated rats, the functional coupling of dopamine receptors with G‐proteins was enhanced. Similarly, PRE‐084 dose‐dependently increased the [35S]GTPγS binding induced by dopamine (Emax 28 and 26% of basal, 0.3 and 1 mg/kg PRE‐084, respectively). By contrast, BD1047, which is without effect on its own, antagonized the effects of amantadine and PRE‐084. Together, these data demonstrate that aminoadamantanes behave as sigma1 receptor agonists, and confirm an involvement of this receptor in modulating dopamine receptors exerted by therapeutically relevant concentrations of amantadine.
Inhibition of auditory cortical responses to ipsilateral stimuli during dichotic listening: evidence from magnetoencephalography
Authors: Brancucci Alfredo , Babiloni Claudio , Babiloni Fabio , Galderisi Silvana , Mucci Armida , Tecchio Franca , Zappasodi Filippo , Pizzella Vittorio , Romani Gian Luca , Rossini Paolo Maria 
Published: April 2004

AbstractThe present magnetoencephalography (MEG) study on auditory evoked magnetic fields (AEFs) was aimed at verifying whether during dichotic listening the contralateral auditory pathway inhibits the ipsilateral one, as suggested by behavioural and patient studies. Ten healthy subjects were given a randomized series of three complex tones (261, 293 and 391 Hz, 500 ms duration), which were delivered monotically and dichotically with different intensities [60, 70 or 80 dBA (audio decibels)]. MEG data were recorded from the right auditory cortex. Results showed that the M100 amplitude over the right auditory cortex increased progressively when tones of increasing intensity were provided at the ipsilateral (right) ear. This effect on M100 was abolished when a concurrent tone of constant intensity was delivered dichotically at the contralateral (left) ear, suggesting that the contralateral pathway inhibited the ipsilateral one. The ipsilateral inhibition was present only when the contralateral tone fundamental frequency was similar to the ipsilateral tone. It was proposed that the occlusion mechanism would be exerted in cortical auditory areas as the dichotic effects were observed at M100 but not M50 component. This is the first evidence showing a neurophysiological inhibition driven by the contralateral auditory pathway over the ipsilateral one during dichotic listening.