bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential responses of bumblebees and diurnal Lepidoptera to vegetation succession in long‐term set‐aside
Authors: Alanen Eeva‐Liisa , Hyvönen Terho , Lindgren Sami , Härmä Oskari , Kuussaari Mikko 
Published: June 2011

Summary1. Establishing temporal habitat patches, such as long‐term set‐aside, is potentially a valuable approach to support pollinator populations in intensively cultivated landscapes. The benefits of this approach are expected to differ between pollinator groups, because of fundamental differences in their ecology.2. We studied the responses of two pollinator groups, bumblebees and diurnal Lepidoptera (butterflies and diurnal moths), to the vegetation succession in experimental set‐aside during six consecutive years. The pollinators were monitored in 24 large treatment plots (50 × 50 m), sown with three different seed mixtures (competitive and two alternatives) and unmanaged or managed by mowing, and on 10 surrounding field margins.3. The responses of the two pollinator groups to vegetation succession were distinctly different. Bumblebees showed a very strong positive response to the diverse seed mixture with abundant floral resources, and their abundance peaked in the first year. The species richness and abundance of Lepidoptera were increased gradually, suggesting differential colonization speeds of species and a gradual establishment of populations. Lepidopteran abundance reached the level of the field margins in 3 years, whereas the corresponding species richness level was not reached. The benefits of the alternative seed mixtures were less pronounced in Lepidoptera than in bumblebees. No effects of the mowing treatment on either species group were detected.4. Within both pollinator groups, the response to vegetation succession was associated with species traits. In bumblebees, long‐tongued species (indicating specialization) were increased during succession. In butterflies and diurnal moths, colonization success of species was strongly correlated with their wing span (indicating mobility). The most successful colonizers in butterflies were grass feeders and in diurnal moths the species feeding on leguminous plants at the larval stage.5. Synthesis and applications.The ecological requirements of different pollinator groups should be taken into account when establishing set‐aside. Supporting bumblebees is possible even on short‐term set‐aside, assuming nectar and pollen sources are made available. The occurrence of butterflies and diurnal moths is strongly driven by additional factors, such as the availability of larval host plants as well as adult mobility, which calls for set‐aside management regimes to be in place for several years.
Boundary matters: clinical leadership and the distinctive disciplinary contribution of nursing to multidisciplinary care
Authors: McNamara Martin S , Fealy Gerard M , Casey Mary , Geraghty Ruth , Johnson Maree , Halligan Phil , Treacy Pearl , Butler Michelle 
Published: June 2011

Aims.  To describe Irish nurses’ views of clinical leadership and to describe their clinical leadership development needs.Background.  Nurses are often unclear about the precise nature of clinical leadership and its impact on the processes and outcomes of care and little is known about their self‐perceived clinical leadership development needs.Design.  Seventeen focus group interviews were conducted with a purposive sample of 144 nurses from 13 practice settings. A conceptual lens was provided by the work of Bernstein and Young who emphasise the epistemological, practical and relational significance of boundaries and how they relate in fundamental ways to professionals’ sense of their distinctive disciplinary identities and membership of specialised communities of practice.Methods.  Focus group data were collected using semi‐structured topic guides. Analysis was facilitated by NVivo 7© and interpretation was informed by a conceptual framework arising from the interplay of emerging themes and the literature review.Results.  The implications for clinical leadership development of two critical concepts, ‘representing nursing’ and ‘compensatory action’, are discussed in detail.Conclusions.  Clinical leadership development should emphasise the development of all nurses as clinical leaders in the context of the delineation, clarification and articulation of their distinctive contribution in multidisciplinary care settings.Relevance to clinical practice.  Clinical leaders are recognised as practice experts and as leaders in their particular fields. Recognition and influence in and beyond the immediate context of care depends greatly on their ability to articulate the distinct nursing contribution to patient care. This ability provides an essential resource to resist the ongoing blurring, effacement and dilution of nurses’ roles.
Forecasting the ward climate: a study from a dementia care unit
Authors: Edvardsson David , Sandman Per‐Olof , Rasmussen Birgit 
Published: June 2011

Aims and objectives.  This article present findings from a study aiming to explore the psychosocial climate and its influence on the well‐being of people with dementia in a psycho‐geriatric hospital unit.Background.  Environmental influence in dementia is well explored in relation to the physical environment; however, few studies have explored the psychosocial environment and its influence on well‐being.Design.  The study had a grounded theory design.Methods.  Participant observations were conducted in a psycho‐geriatric ward for assessment and treatment of people with dementia in Sweden (n = 36 hours). Data were collected and analysed in a dialectical fashion using the principles of grounded theory methodology.Results.  The basic social process that best accounted for the variation in the psychosocial climate and well‐being of patients at the unit was ‘staff presence or absence’, conceptualised as the core category. Three categories emerged in relation to the core category; ‘sharing place and moment’, ‘sharing place but not moment’ and ‘sharing neither place nor moment’.Conclusions.  Staff were catalysts for the psychosocial climate and when being present and engaged they could create a climate interpreted as at‐homeness which supported patient well‐being. When being absent, the climate quickly became anxious and this facilitated patient ill‐being. To provide quality care for people with dementia staff need to be aware of their role in setting the emotional tone of the psychosocial climate and also that this emotional tone significantly influences patient well‐being.Relevance to clinical practice.  The findings are clinically relevant and can be operationalised and applied in clinical practice. Awareness of the intimate connection between staff presence and absence, the psychosocial climate and patient well‐being highlights an ethical responsibility to question: routines that promote staff absence; a culture of merely ‘doing for’; and nursing tasks which involve a minimum of staff–patient interaction. The findings have implications for managers as well as for clinical staff.
The pathogenic persona of community‐associated oral streptococci
Authors: Whitmore Sarah E. , Lamont Richard J. 
Published: June 2011

SummaryThe mitis group streptococci (MGS) are widespread in the oral cavity and are traditionally associated with oral health. However, these organisms have many attributes that contribute to the development of pathogenic oral communities. MGS adhere rapidly to saliva‐coated tooth surfaces, thereby providing an attachment substratum for more overtly pathogenic organisms such as Porphyromonas gingivalis, and the two species assemble into heterotypic communities. Close physical association facilitates physiologic support, and pathogens such as Aggregatibacter actinomycetemcomitans display resource partitioning to favour carbon sources generated by streptococcal metabolism. MGS exchange information with community members through a number of interspecies signalling systems including AI‐2 and contact dependent mechanisms. Signal transduction systems induced in P. gingivalis are based on protein dephosphorylation mediated by the tyrosine phosphatase Ltp1, and converge on a LuxR‐family transcriptional regulator, CdhR. Phenotypic responses in P. gingivalis include regulation of hemin uptake systems and gingipain activity, processes that are intimately linked to the virulence of the organism. Furthermore, communities of S. gordonii with P. gingivalis or with A. actinomycetemcomitans are more pathogenic in animal models than the constituent species alone. We propose that MGS should be considered accessory pathogens, organisms whose pathogenic potential only becomes evident in the context of a heterotypic microbial community.
Loss of co‐chaperone TopJ impacts adhesin P1 presentation and terminal organelle maturation in Mycoplasma pneumoniae
Authors: Cloward Jason M. , Krause Duncan C. 
Published: June 2011

Summary Mycoplasma pneumoniae is a wall‐less human respiratory tract pathogen that colonizes mucosal epithelium via a polar terminal organelle having a central electron‐dense core and adhesin‐related proteins clustered at a terminal button. A mutant lacking J‐domain co‐chaperone TopJ is non‐cytadherent and non‐motile, despite having a core and normal levels of the major cytadherence‐associated proteins. J‐domain co‐chaperones work with DnaK to catalyse polypeptide binding and subsequent protein folding. Here we compared features of the topJ mutant with other cytadherence mutants to elucidate the contribution of TopJ to cytadherence function. The topJ mutant was similar ultrastructurally to a non‐cytadherent mutant lacking terminal organelle proteins B/C, including aberrant core positioning and cell morphology in thin sections, but exhibited a hybrid satellite growth pattern with features of mutants both having and lacking a core. Time‐lapse images of mycoplasmas expressing a YFP fusion with terminal organelle protein P41 suggested that terminal organelle formation/positioning was delayed or poorly co‐ordinated with cell growth in the absence of TopJ. TopJ required a core for localization, perhaps involving HMW1. P1 trypsin accessibility on other non‐cytadherent mutants was significantly enhanced over wild type but unexpectedly was reduced with topJ mutant cells, suggesting impaired processing, translocation and/or folding of this adhesin.
Vanadate and triclosan synergistically induce alginate production by Pseudomonas aeruginosa strain PAO1
Authors: Damron F. Heath , Davis Jr Michael R. , Withers T. Ryan , Ernst Robert K. , Goldberg Joanna B. , Yu Guangli , Yu Hongwei D. 
Published: June 2011

SummaryAlginate overproduction by P. aeruginosa strains, also known as mucoidy, is associated with chronic lung infections in cystic fibrosis (CF). It is not clear how alginate induction occurs in the wild‐type (wt) mucA strains. When grown on Pseudomonas isolation agar (PIA), P. aeruginosa strains PAO1 and PA14 are non‐mucoid, producing minimal amounts of alginate. Here we report the addition of ammonium metavanadate (AMV), a phosphatase inhibitor, to PIA (PIA‐AMV) induced mucoidy in both these laboratory strains and early lung colonizing non‐mucoid isolates with a wt mucA. This phenotypic switch was reversible depending on the availability of vanadate salts and triclosan, a component of PIA. Alginate induction in PAO1 on PIA‐AMV was correlated with increased proteolytic degradation of MucA, and required envelope proteases AlgW or MucP, and a two‐component phosphate regulator, PhoP. Other changes included the addition of palmitate to lipid A, a phenotype also observed in chronic CF isolates. Proteomic analysis revealed the upregulation of stress chaperones, which was confirmed by increased expression of the chaperone/protease MucD. Altogether, these findings suggest a model of alginate induction and the PIA‐AMV medium may be suitable for examining early lung colonization phenotypes in CF before the selection of the mucA mutants.
Inside‐out Z rings – constriction with and without GTP hydrolysis
Authors: Osawa Masaki , Erickson Harold P. 
Published: June 2011

SummaryThe bacterial tubulin homologue FtsZ forms a ring‐like structure called the Z ring that drives cytokinesis. We showed previously that FtsZ–YFP–mts, which has a short amphipathic helix (mts) on its C terminus that inserts into the membrane, can assemble contractile Z rings in tubular liposomes without any other protein. Here we study mts–FtsZ–YFP, where the membrane tether is switched to the opposite side of the protofilament. This assembled ‘inside‐out’ Z rings that wrapped around the outside surface of tubular liposomes. The inside‐out Z rings were highly dynamic, and generated a constriction force that squeezed the tubular liposomes from outside. This is consistent with models where the constriction force is generated by curved protofilaments bending the membrane. We used this system to test how GTP hydrolysis by FtsZ is involved in Z‐ring constriction. Without GTP hydrolysis, Z rings could still assemble and generate an initial constriction. However, the constriction quickly stopped, suggesting that Z rings became rigidly stabilized in the absence of GTP hydrolysis. We propose that remodelling of the Z ring, mediated by GTP hydrolysis and exchange of subunits, is necessary for the continuous constriction.
Regulation of transcription by DNA supercoiling in Mycoplasma genitalium: global control in the smallest known self‐replicating genome
Authors: Dorman Charles J. 
Published: June 2011

SummaryThe mollicute Mycoplasma genitalium causes sexually transmitted disease in humans. It has recently come to widespread public attention through its involvement in pioneering synthetic biology experiments. The 580‐kilo‐base‐pair genome of M. genitalium contains just 470 genes, few of which seem to encode conventional transcription regulators. This raises the important question of how does this simple organism control its gene expression? The finding that the transcription of an osmotically inducible gene encoding a lipoprotein is sensitive to antibiotics that inhibit the activity of DNA gyrase, the enzyme that introduces negative supercoiling into DNA, raises the possibility that changes in DNA supercoiling provide a regulatory mechanism for controlling transcription in M. genitalium.
Is there an important role for reactive oxygen species and redox regulation during floral senescence?
Authors: ROGERS HILARY J. 
Published: June 2011

ABSTRACTSenescence is a highly regulated process terminating with programmed cell death (PCD). Floral senescence, and in particular petal senescence, forms an interesting model to study this process in that floral lifespan is species specific and linked to biological function. A feature of petal senescence is a rise in reactive oxygen species (ROS) and a change in redox balance. A key question is whether this is merely a consequence of de‐regulation of antioxidant systems as cells enter PCD, or whether the rise in ROS may have a regulatory or signalling function. An important division in the physiology of floral senescence is between species in which ethylene is a key regulator, and those in which it appears not to perform an important regulatory role. Another important question we can therefore ask is whether the redox and ROS changes have the same significance in species with different physiologies. Transcriptomic studies in ethylene‐sensitive and ‐insensitive species allow us to further determine whether changes in the activity of ROS‐scavenging enzymes are transcriptionally regulated during floral senescence. Finally, it is important to assess how a signalling role for ROS or redox status would fit with known plant growth regulator (PGR) control of floral senescence.
Ethanol consumption and pineal melatonin daily profile in rats
Authors: Peres Rafael , do Amaral Fernanda Gaspar , Madrigrano Thiago Cardoso , Scialfa Julieta Helena , Bordin Silvana , Afeche Solange Castro , Cipolla‐Neto José 
Published: June 2011

ABSTRACTIt is well known that melatonin participates in the regulation of many important physiological functions such as sleep–wakefulness cycle, motor coordination and neural plasticity, and cognition. However, as there are contradictory results regarding the melatonin production diurnal profile under alcohol consumption, the aim of this paper was to study the phenomenology and mechanisms of the putative modifications on the daily profile of melatonin production in rats submitted to chronic alcohol intake. The present results show that rats receiving 10% ethanol in drinking water for 35 days display an altered daily profile of melatonin production, with a phase delay and a reduction in the nocturnal peak. This can be partially explained by a loss of the daily rhythm and the 25% reduction in tryptophan hydroxylase activity and, mainly, by a phase delay in arylalkylamine N‐acetyltransferase gene expression and a 70% reduction in its peak activity. Upstream in the melatonin synthesis pathway, the results showed that noradrenergic signaling is impaired as well, with a decrease in β1 and α1 adrenergic receptors' mRNA contents and in vitro sustained loss of noradrenergic‐stimulated melatonin production by glands from alcohol‐treated rats. Together, these results confirm the alterations in the daily melatonin profile of alcoholic rats and suggest the possible mechanisms for the observed melatonin synthesis modification.
Dry matter and calcium digestibility in captive veiled chameleons (Chamaeleo calyptratus)
Authors: Hoby S. , Clauss M. , Aebischer A. , Wenker C. , Robert N. , Liesegang A. 
Published: June 2011

SummaryAlthough metabolic bone disease (MBD) is a very common disease in reptiles kept as pets, empirical data on the calcium (Ca) metabolism of reptiles are still scarce. We used the opportunity of a large‐scale experimental study on growth and clinical manifestations of MBD in captive veiled chameleons (Chamaeleo calyptratus) to measure the apparent dry matter (DM) and Ca digestibility in 19 animals (6–49 g), receiving locust nymphs (Locusta migratoria) of two size classes (0.05 and 0.5 g) with or without supplementation of Ca, vitamin A and cholecalciferol (Group A: Ca 0.04‐0.09%DM; Group B: Ca 0.47‐0.84%DM). Dry matter digestibility was significantly lower for animals receiving smaller‐sized prey. A regression analysis of dietary Ca vs. digestible Ca content revealed a complete ‘true’ digestibility of Ca for the range of investigated diets, which might indicate that requirements for this mineral were not yet exceeded by the diets used (so that a reduction in Ca absorption would be induced). Options of higher dietary Ca provision, and reactions of chameleons to such diets, should be further investigated.
Effects of dietary carbohydrate sources on plasma glucose, insulin and IGF‐I levels in multiparous sows
Authors: Wientjes J. G. M. , Soede N. M. , Aarsse F. , Laurenssen B. F. A. , Koopmanschap R. E. , van den Brand H. , Kemp B. 
Published: June 2011

SummaryEffects of different carbohydrate sources on plasma glucose, insulin and insulin‐like growth factor‐I (IGF‐I) levels were compared to subsequently be able to study effects of insulin‐stimulating diets on follicle development in sows. The following feed components were tested in 12 sows during six consecutive test periods of 9.5 days: dextrose (DEX), sucrose (SUC), lactose (LAC), dextrose plus lactose (DL), sucrose plus lactose (SL), dextrose plus sugarbeet pulp (DSBP) and control (CON). On day 2, 5 and 9 of each test period, plasma glucose (only at day 9), insulin and IGF‐I profiles were determined. Despite similar glucose profiles for all diets, the postprandial insulin response was higher for DL and SL compared with CON and LAC; the other diets were intermediate. Plasma IGF‐I levels were higher in CON, LAC and SL compared with DSBP, but differences were only marginal. It was concluded that dextrose and sucrose have the potential to stimulate fast and high insulin peaks, especially when combined with additional lactose. Despite the high dextrose in the DSBP diet, the insulin response was flattened, probably due to the viscosity of sugarbeet pulp. The results show that modulation of plasma insulin levels by dietary carbohydrates seems possible in anabolic sows, but IGF‐I levels are less easily modified.
What people say about travelling outdoors after their stroke: A qualitative study
Authors: Barnsley Lara , McCluskey Annie , Middleton Sandy 
Published: June 2011

Background/aim: Reduced walking ability and loss of confidence are common after stroke. Many people cannot drive or use public transport, which can restrict participation. This qualitative study aimed to explore the experiences and attitudes of people following stroke to travelling outdoors early after hospital discharge.Methods: Two semi‐structured interviews were conducted with 19 people post‐stroke, all of whom were receiving rehabilitation to increase outdoor travel. Mean age was 68.6 years (SD 11.7 years). Eight significant others also participated. Interviews were conducted at home (median 21 days post‐discharge), with a second interview three months later. Questions focussed on common destinations, modes of travel including driving when relevant and factors that influenced outdoor travel. Qualitative data were analysed using constant comparative (grounded theory) methods, resulting in themes and categories.Results: People with stroke were categorised as either ahesitantorconfident explorer, in relation to walking, catching public transport and driving. Factors influencing outdoor travel included their emotional disposition, having meaningful destinations, expectations of recovery and the sphere of influence, including family and therapists. These factors could have an enabling or restricting effect. A pre‐stroke walking habit also positively contributed to outdoor travel. Gate‐keeping by therapists, general practitioners and family members seemed to adversely affect travel.Conclusions: This emerging theory offers insights into the experiences and attitudes to outdoor travel of people who were ambulant and participating in community rehabilitation following a stroke. Future research could explore the experiences of people with more severe mobility, cognitive and communication problems.
Receptor dependent immobilization of spermatozoa by sperm immobilization factor isolated from Escherichia coli: Proof of evidence
Authors: Kumar Vijay , Prabha Vijay , Kaur Siftjit , Kaur Kiranjeet , Singh SK 
Published: June 2011

Objective:  To examine the receptor‐ligand interaction between E. coli and spermatozoa resulting in sperm immobilization.Methods:  Sperm immobilization factor (SIF) was isolated and purified from filtrate of E. coli suspension. Receptor on human spermatozoa for SIF was made to isolated and purified by salt extraction, gel permeation and ion exchange chromatography. Receptor dependent immobilization of spermatozoa by SIF was confirmed by competitive inhibition by addition of the purified receptor and binding to sperm receptor by Fluorescin Isothiocynate (FITC) labelled SIF using fluorescence microscopy.Results:  Heat labile, non‐dialyzable, sperm immobilization factor of ∼56 kDa was isolated and purified from E. coli. Using SIF as a tool, receptor of 113 kDa could be isolated and purified from human spermatozoa. Addition of purified receptor completely inhibited sperm immobilization and death induced by SIF suggesting receptor‐dependent immobilization of spermatozoa. Further incubation of sperm with FITC labelled SIF resulted in staining of whole sperm.Conclusion:  The study provides evidence of receptor‐ligand interaction between E. coli and spermatozoa.