bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geographical range size and host specificity in ectoparasites: a case study withAmphipsyllafleas and rodent hosts
Authors: Shenbrot Georgy , Krasnov Boris , Lu Liang 
Published: June 2007

AbstractAim To identify the factors that determine the geographical range sizes of ectoparasites with different degrees of host specificity.Location The study used data on the distributions of fleas of the genusAmphipsyllaand their rodent hosts across the Holarctic.Methods All known points of occurrence of 32 flea species and 51 species of their rodent hosts were mapped. The shape and size of the geographical range of each species were estimated using a combination of the minimal convex polygon technique and modelling with thegarpalgorithm. Factors determining the geographical range sizes of the fleas were identified using stepwise multiple regression analysis.Results The geographical range size of fleas that are strongly host‐specific across their entire ranges correlated positively with the geographical range size of the fleas’ principal hosts, and negatively with the geographical range size of the fleas’ potential competitors. The geographical range sizes of both (1) fleas that are locally host‐specific but that shift their host preferences geographically, and (2) host‐opportunistic fleas were positively correlated only with the area of the geographical ranges of their principal hosts. Strongly host‐specific fleas occupied 0.2–80.0% of the geographical range of their principal hosts, whereas this figure was 0.9–83.7% in locally host‐specific fleas and 16.6–63.7% in host‐opportunistic fleas.Main conclusions The main determinant of the geographical range size of a flea species is the size of the geographical range of its hosts. The role of potential competitors in determining the geographical range size is stronger in host‐specific than in host‐opportunistic fleas. Cases in which the geographical range of a parasite is smaller than the geographical range(s) of its host(s) owing to narrower parasite environmental tolerances are much more frequent in host‐opportunistic than in host‐specific fleas.
No effect of varying soil resource heterogeneity on plant species richness in a low fertility grassland
Authors: REYNOLDS HEATHER L. , MITTELBACH GARY G. , DARCY‐HALL TARA L. , HOUSEMAN GREGORY R. , GROSS KATHERINE L. 
Published: June 2007

Summary

Coexistence theory predicts that greater heterogeneity of resources or other fitness‐constraining environmental factors will promote species diversity, yet this classic mechanism of coexistence has rarely been tested in manipulative field experiments.
Here we present results from the fourth year of a long‐term experiment designed to test the heterogeneity‐diversity hypothesis in a low productivity grassland where we directly manipulated the spatial heterogeneity of soil nutrients. In addition to unfertilized controls, we created heterogeneous and homogeneous nutrient enrichment treatments by applying fertilizer to field plots in a patchy or uniform manner. Fertilization treatments were crossed with seed addition and cover reduction treatments, to allow examination of the effects of recruitment limitation and competition from established vegetation on diversity responses to nutrient heterogeneity.
In contrast to predictions, we found that spatially heterogeneous soil nutrient supply did not promote increased species richness or greater species sorting relative to a uniform supply of soil nutrients. Instead, both nutrient enrichment treatments depressed plant species richness (especially at small spatial scales) and, depending on cover reduction and on spatial location in the field, increased the abundance of two spreading clonal species.
Our results do not support the heterogeneity‐diversity hypothesis, and suggest that the response of clonal species to nutrient enrichment may constrain how plant diversity responds to resource heterogeneity. Future tests of the heterogeneity‐diversity hypothesis should explicitly consider the scale of resource heterogeneity and foraging capability of the plant species in the community.
The effectiveness of antidepressant medication in the management of behaviour problems in adults with intellectual disabilities: a systematic review
Authors: Sohanpal S. K. , Deb S. , Thomas C. , Soni R. , Lenôtre L. , Unwin G. 
Published: June 2007

AbstractBackground  A comprehensive systematic review was performed to establish the current evidence base regarding the effectiveness of antidepressant medication for the management of behaviour problems in adults with intellectual disabilities.Method  An electronic search of PsycInfo, Embase, Medline and Cinahl databases was conducted spanning the time period 1990 to October 2005 for primary trials. This was supplemented by hand searching and cross‐referencing of relevant reviews. Strict scientific methodology requirements were formulated that the studies had to meet in order to merit inclusion in this review.Results  One crossover randomized controlled trial in a small cohort, seven prospective uncontrolled trials and two retrospective studies were yielded in the search. Of these, one explored the effectiveness of the tricyclic antidepressant – clomipramine, and nine considered various selective serotonin reuptake inhibitors (SSRIs).Conclusion  Evidence based primarily on a small number of either prospective or retrospective case studies that included a small number of participants and often used non‐validated outcome measures for a short period of follow‐up, suggests that antidepressants, particularly SSRIs, show improvement of aggression and self‐injurious behaviour on average in less than 50% of cases and the rest show either no improvement or deterioration. The effect is most pronounced in the presence of an underlying anxiety or an associated diagnosis of obsessive‐compulsive disorder. Most studies have highlighted the concern regarding adverse effects.
The effectiveness of antipsychotic medication in the management of behaviour problems in adults with intellectual disabilities
Authors: Deb S. , Sohanpal S. K. , Soni R. , Len tre L. , Unwin G. 
Published: June 2007

AbstractBackground  Psychopharmacological intervention in the management of behaviour problems in adults with intellectual disabilities (ID) has become a common treatment strategy. This has become a cause for concern, given that the evidence for its effectiveness is uncertain and most drugs are not licensed for this use.Methods  A comprehensive systematic review of empirical research on the effectiveness of antipsychotic medication was conducted. Electronic and manual searches of literature were conducted. Stringent scientific methodology determined those primary trials that were worthy of inclusion.Results  This review revealed one randomized controlled trial (RCT), one controlled, four uncontrolled prospective and three retrospective case series studies in adults. Additionally, two studies in both adults and children – one crossover RCT and one prospective controlled trial – were found.Conclusion  Presently, there is RCT‐based evidence for risperidone to be effective in both adults and children; however, this treatment carries a certain amount of risk associated with adverse effects. There is also evidence to support the use of other antipsychotics, primarily atypicals, but the evidence is based on noncontrolled case studies. There is currently not enough evidence available to recommend specific medication for specific behaviour problems. Before prescribing medication, clinicians should carry out a thorough assessment of behaviour, including its causes and consequences, and draw up a formulation providing the rationale for the prescribed intervention after considering all medication‐ and nonmedication‐based management options.
Symptoms of dementia among adults with Down's syndrome: a qualitative study
Authors: Deb S. , Hare M. , Prior L. 
Published: June 2007

AbstractBackground  Dementia is common among adults with Down's syndrome (DS); yet the diagnosis of dementia, particularly in its early stage, can be difficult in this population. One possible reason for this may be the different clinical manifestation of dementia among people with intellectual disabilities.Aims  The aim of this study was to map out the carers' perspective of symptoms of dementia among adults with DS in order to inform the development of an informant‐rated screening questionnaire.Method  Unconstrained information from carers of people with DS and dementia regarding the symptoms, particularly the early symptoms of dementia, was gathered using a qualitative methodology. Carers of 24 adults with DS and dementia were interviewed. The interviews were recorded and fully transcribed. The transcripts were then analysed using qualitative software.Results  There appeared to be many similarities in the clinical presentation of dementia in adults with DS and the non‐intellectually disabled general population. Like in the non‐intellectually disabled general population, forgetfulness especially, impairment of recent memory combined with a relatively intact distant memory and confusion were common, and presented early in dementia among adults with DS. However, many ‘frontal lobe’‐related symptoms that are usually manifested later in the process of dementia among the general population were common at an early stage of dementia among adults with DS. A general slowness including slowness in activities and speech, other language problems, loss of interest in activities, social withdrawal, balance problems, sleep problems, loss of pre‐existing skills along with the emergence of emotional and behaviour problems were common among adults with DS in our study.Conclusions  This study highlights the similarities in the clinical presentation of dementia among the general population and people with DS with a particular emphasis on the earlier appearance of symptoms associated with the frontal lobe dysfunction among adults with DS.
The effectiveness of mood stabilizers and antiepileptic medication for the management of behaviour problems in adults with intellectual disability: a systematic review
Authors: Deb S. , Chaplin R. , Sohanpal S. , Unwin G. , Soni R. , Lenotre L. 
Published: June 2007

AbstractBackground  Psychotropic medications are used to manage behaviour problems in adults with intellectual disability (ID). One group of psychotropic medication are mood stabilizers such as lithium and some antiepileptic drugs.Method  A comprehensive systematic review was performed to determine the evidence base for the effectiveness of mood stabilizers in the management of behaviour problems among adults with ID. Electronic searches of PsycInfo, Medline, Embase and Cinahl databases were conducted, as well as a thorough hand search for relevant literature. We reviewed primary trials relating to adults only that satisfied strict inclusion criteria.Results  One randomized controlled trial (RCT) relating to lithium use and two non‐RCTs, one on lithium and the other on carbamazepine, were revealed. In addition, one prospective non‐controlled trial on sodium valproate and three retrospective case series studies were discovered, of which one considered the efficacy of lithium, one valproate and one topiramate.Conclusions  The current evidence lends some support for the use of lithium and some antiepileptic mood stabilizer medication for the management of behaviour problems in adults with ID. However, because most studies reviewed here are riddled with obvious methodological constrains, the findings have to be interpreted with caution.
Decoding dumping ducks
Authors: DICKINSON JANIS L. 
Published: June 2007

AbstractConspecific brood parasitism, where females of the same species lay eggs in each other's nests, is common in waterfowl, and is usually considered costly to host females, which are stuck looking after eggs and chicks that are not their own. However, since female waterfowl often exhibit an unusual propensity to nest near where they were born, there has been some uncertainty over whether, in ducks and geese, laying in nests of conspecifics really is parasitism. Do parasitic and host females tend to be related? And is parasitism actually a form of cooperation in disguise? In a population in Hudson Bay, Andersson & Waldeck (this issue) found that ‘parasitic’ eggs in nests of the common eider, Somateria mollissima sedentaria, are more closely related to host eggs than expected by chance. In fact, host and ‘donor’ eggs are more closely related than are females breeding at neighbouring nests. The Hudson Bay population of common eiders is unusual, because unlike in more benign climates, females do not tend to breed near their natal nest. Spatial proximity alone cannot account for the high relatedness between host eggs and ‘dumped’ or donor eggs. Instead, the high relatedness values are probably the result of active recognition, where females favour kin, either when dumping or accepting eggs. These new data, along with evidence indicating that the donor lays the first egg in the nest nearly half the time, suggest that what appears to be parasitism in common eiders may be a form of kin‐based cooperation.
Defining Candida albicans stationary phase by cellular and DNA replication, gene expression and regulation
Authors: Uppuluri Priya , Chaffin W. LaJean 
Published: June 2007

SummaryStationary phase Candida albicans yeast cells harbour properties of better adherence, virulence and elevated drug resistance. C. albicans stationary phase is not well characterized in vitro either physiologically or molecularly. C. albicans yeast cells were grown in rich medium with 2% glucose. Based on growth and DNA profiles of cells, and by measurement of glucose and ethanol in the medium, we defined the timing of C. albicans entry into different growth transitions. We found that, compared with 24 h cells, mRNA content was less abundant in post‐diauxic shift phase and even less in stationary phase C. albicans cells. Further analysis of the C. albicans transcriptome with oligonucleotide‐based microarrays revealed that although the overall mRNA content had decreased, transcripts of many genes increased in post‐diauxic shift phase as well as stationary phase. Genes involved in processes such as gluconeogenesis, stress resistance, adherence, DNA repair and ageing were expressed at higher levels at and beyond post‐diauxic shift phase. Many C. albicans genes associated with virulence, drug resistance and cell‐wall biosynthesis were expressed only at stationary phase. By screening 108 C. albicans transcription factor and cell‐wall mutants we identified 17 genes essential for either entry or survival in stationary phase at 30°C.
CsrA of Bacillus subtilis regulates translation initiation of the gene encoding the flagellin protein (hag) by blocking ribosome binding
Authors: Yakhnin Helen , Pandit Pallavi , Petty Tom J. , Baker Carol S. , Romeo Tony , Babitzke Paul 
Published: June 2007

SummaryThe global regulatory Csr (carbon storage regulator) and the homologous Rsm (repressor of secondary metabolites) systems of Gram‐negative bacteria typically consist of an RNA‐binding protein (CsrA/RsmA) and at least one sRNA that functions as a CsrA antagonist. CsrA modulates gene expression post‐transcriptionally by regulating translation initiation and/or mRNA stability of target transcripts. While Csr has been extensively studied in Gram‐negative bacteria, until now Csr has not been characterized in any Gram‐positive organism. csrA of Bacillus subtilis is the last gene of a flagellum biosynthetic operon. In addition to the previously identified σD‐dependent promoter that controls expression of the entire operon, a σA‐dependent promoter was identified that temporally controls expression of the last two genes of the operon (fliW‐csrA); expression peaks 1 h after cell growth deviates from exponential phase. hag, the gene encoding flagellin, was identified as a CsrA‐regulated gene. CsrA was found to repress hag′–′lacZ expression, while overexpression of csrA reduces cell motility. In vitro binding studies identified two CsrA binding sites in the hag leader transcript, one of which overlaps the hag Shine–Dalgarno sequence. Toeprint and cell‐free translation studies demonstrate that bound CsrA prevents ribosome binding to the hag transcript, thereby inhibiting translation initiation and Hag synthesis.
Parenchyma cell respiration and survival in secondary xylem: does metabolic activity decline with cell age?
Authors: SPICER R. , HOLBROOK N. M. 
Published: June 2007

ABSTRACTSapwood respiration often declines towards the sapwood/heartwood boundary, but it is not known if parenchyma metabolic activity declines with cell age. We measured sapwood respiration in five temperate species (sapwood age range of 5–64 years) and expressed respiration on a live cell basis by quantifying living parenchyma. We found no effect of parenchyma age on respiration in two conifers (Pinus strobus, Tsuga canadensis), both of which had significant amounts of dead parenchyma in the sapwood. In angiosperms (Acer rubrum, Fraxinus americana, Quercus rubra), both bulk tissue and live cell respiration were reduced by about one‐half in the oldest relative to the youngest sapwood, and all sapwood parenchyma remained alive. Conifers and angiosperms had similar bulk tissue respiration despite a smaller proportion of parenchyma in conifers (5% versus 15–25% in angiosperms), such that conifer parenchyma respired at rates about three times those of angiosperms. The fact that 5‐year‐old parenchyma cells respired at the same rate as 25‐year‐old cells in conifers suggests that there is no inherent or intrinsic decline in respiration as a result of cellular ageing. In contrast, it is not known whether differences observed in cellular respiration rates of angiosperms are a function of age per se, or whether active regulation of metabolic rate or positional effects (e.g. proximity to resources and/or hormones) could be the cause of reduced respiration in older sapwood.
ANAC012, a member of the plant‐specific NAC transcription factor family, negatively regulates xylary fiber development in Arabidopsis thaliana
Authors: Ko Jae‐Heung , Yang Seung Hwan , Park Andrew H. , Lerouxel Olivier , Han Kyung‐Hwan 
Published: June 2007

SummaryVascular plants evolved to have xylem that provides physical support for their growing body and serves as a conduit for water and nutrient transport. In a previous study, we used comparative‐transcriptome analyses to select a group of genes that were upregulated in xylem of Arabidopsis plants undergoing secondary growth. Subsequent analyses identified a plant‐specific NAC‐domain transcription factor gene (ANAC012) as a candidate for genetic regulation of xylem formation. Promoter‐GUS analyses showed that ANAC012 expression was preferentially localized in the (pro)cambium region of inflorescence stem and root. Using yeast transactivation analyses, we confirmed the function of ANAC012 as a transcriptional activator, and identified an activation domain in the C terminus. Ectopic overexpression of ANAC012 in Arabidopsis (35S::ANAC012 plants) dramatically suppressed secondary wall deposition in the xylary fiber and slightly increased cell‐wall thickness in the xylem vessels. Cellulose compositions of the cell wall were decreased in the inflorescent stems and roots of 35S::ANAC012 plants, probably resulting from defects in xylary fiber formation. Our data suggest that ANAC012 may act as a negative regulator of secondary wall thickening in xylary fibers.
Ethylene receptor degradation controls the timing of ripening in tomato fruit
Authors: Kevany Brian M. , Tieman Denise M. , Taylor Mark G. , Cin Valeriano Dal , Klee Harry J. 
Published: June 2007

SummaryFruit ripening in tomato requires the coordination of both developmental cues and the phytohormone ethylene. The multigene ethylene receptor family has been shown to negatively regulate ethylene signal transduction and suppress ethylene responses. Here we demonstrate that reduction in the levels of either of two family members, LeETR4 or LeETR6, causes an early‐ripening phenotype. We provide evidence that the receptors are rapidly degraded in the presence of ethylene, and that degradation probably occurs through the 26S proteasome‐dependent pathway. Ethylene exposure of immature fruits causes a reduction in the amount of receptor protein and earlier ripening. The results are consistent with a model in which receptor levels modulate timing of the onset of fruit ripening by measuring cumulative ethylene exposure.
Is there a right to donate blood? Patient rights; donor responsibilities
Authors: Franklin Ian M. 
Published: June 2007

summary The objective of this study was to analyse and assess critically whether there is a right to donate blood in the UK.The aim was to provide a basis for blood services, in particular within the UK and European Union (EU), to address claims from deferred donors that there is a right to donate.Recent and ongoing campaigns to change the current life‐long deferral from blood donation in the UK, Canada and USA of men who have/have had sex with men (MSM) have highlighted issues over whether individuals have a right to donate blood. The issue is complicated by allegations of discriminatory behaviour, and in some countries politicians have contributed to the argument. As anti‐discrimination and equality legislation is strengthened in the UK, other groups in addition to MSM may wish to claim a right to donate blood.The methods adopted included discussions with colleagues in UK and European blood services and a review of the medical literature and wider sources using Internet search engines.No clear right to donate blood is apparent, although it is recommended that donor deferral criteria should have a sound basis of evidence. Potential donors have a right to expect a clear explanation of the reason(s) for refusing a donation. Legal safeguards for recipients to receive safe blood transfusions exist.It is concluded that blood recipients in the EU have a right to receive safe blood, and that this should be viewed as the overriding responsibility of blood services.