bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impacts of the invasive Argentine ant on native ants and other invertebrates in coastal scrub in south‐eastern Australia
Authors: ROWLES ALEXEI D. , O'DOWD DENNIS J. 
Published: March 2009

AbstractInvasive ants threaten native biodiversity and ecosystem function worldwide. Although their principal direct impact is usually the displacement of native ants, they may also affect other invertebrates. The Argentine ant, Linepithema humile (Dolichoderinae), one of the most widespread invasive ant species, has invaded native habitat where it abuts peri‐urban development in coastal Victoria in south‐eastern Australia. Here we infer impacts of the Argentine ant on native ants and other litter and ground‐dwelling invertebrates by comparing their abundance and taxonomic composition in coastal scrub forest either invaded or uninvaded by the Argentine ant. Species composition of native ants at bait stations and extracted from litter differed significantly between Argentine ant‐invaded and uninvaded sites and this was consistent across years. Argentine ants had a strong effect on epigeic ants, which were either displaced or reduced in abundance. The native ant Rhytidoponera victoriae (Ponerinae), numerically dominant at uninvaded sites, was completely absent from sites invaded by the Argentine ant. However, small hypogeic ants, including Solenopsis sp. (Myrmicinae) and Heteroponera imbellis (Heteroponerinae), were little affected. Linepithema humile had no detectable effect upon the abundance and richness of other litter invertebrates. However, invertebrate group composition differed significantly between invaded and uninvaded sites, owing to the varied response of several influential groups (e.g. Collembola and Acarina). Floristics, habitat structure and measured environmental factors did not differ significantly between sites either invaded or uninvaded by Argentine ants, supporting the contention that differences in native ant abundance and species composition are related to invasion. Changes in the native ant community wrought by Argentine ant invasion have important implications for invertebrate communities in southern Australia and may affect key processes, including seed dispersal.
Gut passage effect of the introduced red‐whiskered bulbul (Pycnonotus jocosus) on germination of invasive plant species in Mauritius
Authors: LINNEBJERG JANNIE F. , HANSEN DENNIS M. , OLESEN JENS M. 
Published: March 2009

AbstractIn Mauritius, many of the worst invasive plant species have fleshy fruits and rely on animals for dispersal. The introduced red‐whiskered bulbul (Pycnonotus jocosus) feeds on many fleshy‐fruited species, and often moves from invaded and degraded habitats into higher quality native forests, thus potentially acting as a mediator of continued plant invasion into these areas. Furthermore, gut passage may influence seed germination. To investigate this, we fed fleshy fruits of two invasive plant species, Ligustrum robustum and Clidemia hirta, to red‐whiskered bulbuls. Gut passage times of seeds were recorded. Gut‐passed seeds were sown and their germination rate and germination success compared with that of hand‐cleaned seeds, as well as that of seeds in whole fruits. Gut passage and hand‐cleaning had significant positive effects on germination of both species. Gut‐passed seeds of both C. hirta and L. robustum germinated faster than hand‐cleaned seeds. However, for L. robustum, this was only true when compared with hand‐cleaned seeds with intact endocarp; when compared with hand‐cleaned seeds without endocarp, there was no difference. For overall germination success, there was a positive effect of gut passage for C. hirta, but not for L. robustum. For both C. hirta and L. robustum, no seeds in intact fruits geminated, suggesting that removal of pulp is essential for germination. Our results suggest that, first, the initial invasion of native forests in Mauritius may not have happened so rapidly without efficient avian seed dispersers like the red‐whiskered bulbul. Second, the bulbul is likely to be a major factor in the continued re‐invasion of C. hirta and L. robustum into weeded and restored conservation management areas.
Changes in body condition and body size affect breeding and recruitment in fluctuating house mouse populations in south‐eastern Australia
Authors: MUTZE GREGORY J. 
Published: March 2009

AbstractChanges in body condition and body size in field populations of house mice, Mus domesticus, were examined to investigate why mouse populations do not increase rapidly in some years when favourable environmental and demographic conditions indicate they might. Mice had repeated seasonal patterns each year in breeding, growth rates and body condition that reflected the seasonal availability of food, but mean levels for each parameter varied among years. In most years mice lost body condition during summer, breeding declined and population growth slowed. Rapid population growth occurred when body condition was generally high and was maintained throughout summer. Female mice with large body length were more likely to breed than smaller mice, at all times, but changes in body condition accounted for most of the variability in female breeding activity between years and between habitats, and for the seasonal changes in the importance of body length. During rapid population growth, the recruitment rate of juveniles relative to the number of breeding females was 150–300% higher than in other years but adult survival rates were not higher. The data indicate that the ability of mice to maintain body condition, particularly when subject to moisture stress in summer, affects the proportion of females breeding, the number of juveniles weaned and their body condition at weaning, and is promoted by foraging conditions that favour maintenance of juvenile body condition after weaning. These factors, in turn, greatly affect juvenile recruitment rates and eventual population density of mice. Low juvenile survival is suggested as a reason that numbers of house mice in southern Australian cereal‐growing areas do not increase rapidly in some years when other parameters are favourable. Similar processes are likely to play a role in regulating other rodent populations.
Surround suppression sharpens orientation tuning in the cat primary visual cortex
Authors: Okamoto Masahiro , Naito Tomoyuki , Sadakane Osamu , Osaki Hironobu , Sato Hiromichi 
Published: March 2009

AbstractIn the primary visual cortex (V1), the response of a neuron to stimulation of its classical receptive field (CRF) is suppressed by concurrent stimulation of the extraclassical receptive field (ECRF), a phenomenon termed ‘surround suppression’. It is also known that the orientation tuning of V1 neurons becomes sharper as the size of the stimulus increases beyond the CRF. However, there have been few quantitative investigations of the relationship between sharpening of orientation tuning and surround suppression. We examined this relationship in 73 V1 neurons recorded from anesthetized and paralysed cats using sinusoidal grating patches as stimuli. We found that sharpening of orientation tuning was significantly correlated with the strength of surround suppression for large stimuli that cover both CRF and ECRF. Furthermore, simulation analysis using a variety of tuning widths and most suppressive orientation of orientation‐tuned surround suppression demonstrated that broadly orientation‐tuned surround suppression sharpens orientation tuning for large gratings without shift in optimal orientation. Our findings suggest that one of the functional roles of surround suppression in V1 is enhancement of orientation discrimination for large and uniformly patterned objects.
Preference judgements involve a network of structures within frontal, cingulate and insula cortices
Authors: Chaudhry Amir M. , Parkinson John A. , Hinton Elanor C. , Owen Adrian M. , Roberts Angela C. 
Published: March 2009

AbstractEnvironmental stimuli constantly compete for human attention and in many cases decisions are made based on the affective meaning they convey. Although the network of structures involved in processing affective value has been well described, the specific contribution of these structures to the process by which affective value guides decision making is less well understood and is the focus of the present study. Thus, subjects read descriptions of individually tailored holidays, varying in incentive value and then made preference judgements, cognitive judgements or no decision. Choices made from an affective perspective, compared with those made from a cognitive perspective, activated a region of the anterior insula/operculum and also the anterior cingulate cortex. Furthermore, activity in perigenual, anterior cingulate cortex was correlated with subjective ratings of incentive value. In contrast, medial orbitofrontal cortex (OFC) and a region of posterior ventrolateral prefrontal cortex (PFC), bordering on the insula, were found to be more active when affective stimuli guided response selection than when no selection was made. However, only the activity in the ventrolateral PFC was specific to response selection based on affective compared with cognitive judgements. It is proposed that the necessary introspection required to make subjective preference judgements is provided by the insula and cingulate cortices, while the medial OFC and posterior ventrolateral PFC/insula cortices contribute to stimulus evaluation and motivational aspects of response selection, respectively.
Deficient responses from the lateral geniculate nucleus in humans with amblyopia
Authors: Hess Robert F. , Thompson Benjamin , Gole Glen , Mullen Kathy T. 
Published: March 2009

AbstractAmblyopia or lazy eye is the most common cause of uniocular blindness in adults. It is caused by a disruption to normal visual development as a consequence of unmatched inputs from the two eyes in early life, arising from a turned eye (strabismus), unequal refractive error (anisometropia) or form deprivation (e.g. cataract). Animal models based on extracellular recordings in anesthetized animals suggest that the earliest site of the anomaly in the primate visual pathway is the primary visual cortex (corresponding to the striate cortex, cytoarchitectonic area 17 and area V1), which is where inputs from the two eyes are first combined in an excitatory fashion, whereas more distal and monocular processing structures such as the retina and lateral geniculate nucleus (LGN) are normal. Using high‐field functional magnetic resonance imaging in a group of human adults with amblyopia, we demonstrate that functional deficits are first observable at a thalamic level, that of the LGN. Our results suggest the need to re‐evaluate the current models of amblyopia that are based on the assumption of a purely cortical dysfunction, as well as the role for the LGN in visual development.
Microbial biodiversity of thermophilic communities in hot mineral soils of Tramway Ridge, Mount Erebus, Antarctica
Authors: Soo Rochelle M. , Wood Susanna A. , Grzymski Joseph J. , McDonald Ian R. , Cary S. Craig 
Published: March 2009

SummaryTramway Ridge, located near the summit of Mount Erebus in Antarctica, is probably the most remote geothermal soil habitat on Earth. Steam fumaroles maintain moist, hot soil environments creating extreme local physicochemical differentials. In this study a culture‐independent approach combining automated rRNA intergenic spacer analysis (ARISA) and a 16S rRNA gene library was used to characterize soil microbial (Bacterial and Archaeal) diversity along intense physicochemical gradients. Statistical analysis of ARISA data showed a clear delineation between bacterial community structure at sites close to fumaroles and all other sites. Temperature and pH were identified as the primary drivers of this demarcation. A clone library constructed from a high‐temperature site led to the identification of 18 novel bacterial operational taxonomic units (OTUs). All 16S rRNA gene sequences were deep branching and distantly (85–93%) related to other environmental clones. Five of the signatures branched with an unknown group between candidate division OP10 and Chloroflexi. Within this clade, sequence similarity was low, suggesting it contains several yet‐to‐be described bacterial groups. Five archaeal OTUs were obtained and exhibited high levels of sequence similarity (95–97%) with Crenarchaeota sourced from deep‐subsurface environments on two distant continents. The novel bacterial assemblage coupled with the unique archaeal affinities reinvigorates the hypotheses that Tramway Ridge organisms are relics of archaic microbial lineages specifically adapted to survive in this harsh environment and that this site may provide a portal to the deep‐subsurface biosphere.
Impact of Collimonas bacteria on community composition of soil fungi
Authors: Höppener‐Ogawa Sachie , Leveau Johan H. J. , Hundscheid Maria P. J. , Van Veen Johannes A. , De Boer Wietse 
Published: March 2009

SummaryThe genus Collimonas consists of soil bacteria that have the potential to grow at the expense of living fungal hyphae. However, the consequences of this mycophagous ability for soil fungi are unknown. Here we report on the development of fungal communities after introduction of collimonads in a soil that had a low abundance of indigenous collimonads. Development of fungal communities was stimulated by addition of cellulose or by introducing plants (Plantago lanceolata). Community composition of total fungi in soil and rhizosphere and of arbuscular mycorrhizal fungi in roots was examined by PCR‐DGGE. The introduction of collimonads altered the composition of all fungal communities studied but had no effects on fungal biomass increase, cellulose degrading activity or plant performance. The most likely explanation for these results is that differences in sensitivity of fungal species to the presence of collimonads result in competitive replacement of species. The lab and greenhouse experiments were complemented with a field experiment. Mesh bags containing sterile sand with or without collimonads were buried in an ex‐arable field and a forest. The presence of collimonads had an effect on the composition of fungi invading these bags in the ex‐arable site but not in the forest site.
Mapping field‐scale spatial patterns of size and activity of the denitrifier community
Authors: Philippot Laurent , Čuhel Jiri , Saby Nicolas P.A. , Chèneby Dominique , Chroňáková Alicia , Bru David , Arrouays Dominique , Martin‐Laurent Fabrice , Šimek Miloslav 
Published: March 2009

SummaryThere is ample evidence that microbial processes can exhibit large variations in activity on a field scale. However, very little is known about the spatial distribution of the microbial communities mediating these processes. Here we used geostatistical modelling to explore spatial patterns of size and activity of the denitrifying community, a functional guild involved in N‐cycling, in a grassland field subjected to different cattle grazing regimes. We observed a non‐random distribution pattern of the size of the denitrifier community estimated by quantification of the denitrification genes copy numbers with a macro‐scale spatial dependence (6–16 m) and mapped the distribution of this functional guild in the field. The spatial patterns of soil properties, which were strongly affected by presence of cattle, imposed significant control on potential denitrification activity, potential N2O production and relative abundance of some denitrification genes but not on the size of the denitrifier community. Absolute abundance of most denitrification genes was not correlated with the distribution patterns of potential denitrification activity or potential N2O production. However, the relative abundance of bacteria possessing thenosZgene encoding the N2O reductase in the total bacterial community was a strong predictor of the N2O/(N2 + N2O) ratio, which provides evidence for a relationship between bacterial community composition based on the relative abundance of denitrifiers in the total bacterial community and ecosystem processes. More generally, the presented geostatistical approach allows integrated mapping of microbial communities, and hence can facilitate our understanding of relationships between the ecology of microbial communities and microbial processes along environmental gradients.
eGOVERNMENT AND THE TRANSFORMATION AGENDA
Authors: FOLEY PAUL , ALFONSO XIMENA 
Published: March 2009

Government policy‐making emphasis worldwide is moving increasingly to how ICT can be used to achieve efficiency savings (Gershon 2004) or to transform activities (Cabinet Office; Transformational Government 2005). The role of ICT in achieving efficiency benefits or supporting transformational change is almost universally accepted by policy‐makers, despite the fact that little robust evidence exists.eGovernment evaluation methodologies are reviewed and evidence is provided in this paper to demonstrate that transformational eGovernment projects produce greater benefits than other types of initiatives. The level of benefits for different groups of beneficiaries is examined. A key factor determining benefits and impact of any project is the number of users of the service and/or the frequency of use of a system.
Industrial Diversity, Trade Patterns, and Productivity Convergence
Authors: Stehrer Robert , Woerz Julia 
Published: March 2009

AbstractRecent developments in economic integration show rather diverse patterns of integration in the world economy. Some countries remain predominantly in the low‐tech industries whereas other countries succeed in becoming competitive in high‐tech industries as well. The authors postulate that a country positioning itself at the lower end of the spectrum of high‐tech industries is more favorable to its long‐term development than aiming at the upper end of low‐tech industries. They argue that countries which specialize in the lower end of the medium–high‐tech activities are rewarded by faster productivity increases also in the upper end of the high‐tech industries. In contrast, early specialization in medium–low‐tech branches yields positive spillovers, mainly in the low‐tech sector, which is not conducive to increasing activity in high‐tech industries. The authors sketch a theoretical outline of this idea and present econometric results, including four aggregate manufacturing branches across 37 countries.
The Retreat of Deposit  Dollarization*
Authors: Honohan Patrick 
Published: March 2009

AbstractAfter growing rapidly during the 1990s, the scale of deposit dollarization has slowed or even reversed since 2001. This paper employs an expanded cross‐country data set on the share of bank deposits denominated in foreign currency. It documents the break in trend and seeks to explain this apparent reversal in this aspect of global financial integration. Valuation changes related to dollar weakness from 2002 do not seem to be the cause. But lower inflation in many countries has reduced the attractions of foreign currency as a hedge. Also, the Argentine crisis of 2001–02 may have heightened investor awareness of the risk of forced conversion of foreign currency deposits. A return to higher inflation and fading memories of forced conversions could lead to a resumption in the growth of deposit dollarization, with the banking risks that this can entail.
Why the United Kingdom Should Not Join the Eurozone
Authors: Minford Patrick 
Published: March 2009

AbstractSome years ago I did a fair amount of work on whether Britain should join the euro, in the context of the debate on the ‘five tests’ set out by HM Treasury. Five years on it is an interesting issue to revisit, particularly in the light of the recent banking crisis. In what follows I discuss the potential benefits and costs for the United Kingdom of joining the euro or Economic and Monetary Union, EMU, in much the terms that I did five years ago, because the essential figures and arguments have not changed. This discussion carries no particular implications for other countries: the calculations are highly specific to the United Kingdom. I end up with an effort to put this discussion in the context of the recent crisis.
Comparison of adults with intellectual disabilities and mental health problems admitted to specialist and generic inpatient units
Authors: Hemmings C. P. , O'Hara J. , McCarthy J. , Holt G. , Eoster F. , Costello H. , Hammond R. , Xenitidis K. , Bouras N. 
Published: March 2009

Accessible summary

This research was about people with learning disabilities who went into hospital when they had mental health problems.
We looked at when they went into ordinary mental health units and also into a special unit for people who also have learning disabilities.
We looked at what their mental health problems were and how long they stayed for. We looked at what types of places they were living in before they went to hospital and where they went to live afterwards. We found some differences in what happened to the people depending on where they stayed.
This research will help to find out where people with learning disabilities who also have mental health problems should be treated if they need to go to hospital.

SummaryThis study aimed to compare the characteristics of service users with intellectual disabilities and mental health problems admitted to either a specialist or a generic inpatient unit in an area of South London. Socio‐demographic and clinical characteristics of consecutive admissions over a 5.5‐year period were recorded using a questionnaire. Key differences in psychiatric diagnosis, residence type and discharge destination were found between individuals using generic and specialist provision. Length of stay was significantly longer for specialist unit admissions. Admissions to the specialist unit were significantly more likely to reside with family prior to admission and admissions to generic units were significantly more likely to come from ‘other’ forms of residence such as hostels, prison and ‘no fixed abode’. At discharge the proportion of those admitted to the specialist unit who resided with their families reduced. At the same time the proportion of those living in supported accommodation increased although compared with those admitted to generic units they were still significantly more likely to return to the family home. Significantly, more adults admitted to generic units were diagnosed with an affective disorder. Specialist inpatient provision may be crucial in helping mainstream services meet the needs of individuals with intellectual disabilities and mental health problems.