bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of simulated browsing on growth and leaf chemical properties in Colophospermum mopane saplings
Authors: Kohi Edward M. , De Boer Willem F. , Slot Martijn , Van Wieren Sipke E. , Ferwerda Jelle G. , Grant Rina C. , Heitkönig Ignas M. A. , De Knegt Henjo J. , Knox Nicky , Van Langevelde Frank , Peel Mike , Slotow Rob , Van Der Waal Cornelis , Prins Herbert H. T. 
Published: September 2009

AbstractBrowsing intensity influences a plant’s response to herbivory. Plants face a trade‐off between investment in the production of secondary compounds and investment in growth. To elucidate this trade‐off, we simulated four browsing intensities (0%, 50%, 75% and 100%) on mopane saplings, Colophospermum mopane (J.Kirk ex Benth.) J.Léonard, in a greenhouse experiment. This showed that, with increasing defoliation intensity, plants change their investment strategy. At intermediate levels of defoliation (50%), mopane saplings increased the synthesis of condensed tannins, so that tannin concentrations followed a hump‐shaped relation with defoliation intensity, with significantly higher tannin concentration at intermediate defoliation levels. When defoliated heavily (75% and 100%), tannin concentrations dropped, and plants were carbon stressed as indicated by a reduced growth rate of the stem diameter, and leaf production and mean individual leaf mass were reduced. This suggests that, at intermediate defoliation intensity, the strategy of the plants is towards induced chemical defences. With increasing defoliation, the relative costs of the secondary metabolite synthesis become too high, and therefore, the plants change their growing strategy. Hence, browsers should be able to benefit from earlier browsing by either adopting a low or a relatively high browsing pressure.
Response of Faidherbia albida (Del.) A. Chev., Acacia nigrescens Oliver. and Acacia nilotica (L.) Willd ex Del. seedlings to simulated cotyledon and shoot herbivory in a semi‐arid savanna in Zimbabwe
Authors: Dube Sijabulile , Mlambo Donald , Sebata Allan 
Published: September 2009

AbstractWoody plant seedling establishment is constrained by herbivory in many semi‐arid savannas. We clipped shoots and cotyledons of three woody species 5‐day (=‘early’) or 28‐day (= ‘late’) post‐emergence to simulate herbivory. Seedlings had shoot apex, one or two cotyledon(s) removed, or were retained intact. Survival rates were ≥80%, ≥40% and ≥20% for Acacia nilotica, Acacia nigrescens and Faidherbia albida respectively. F. albida mobilized stored cotyledon reserves faster and consequently shed the cotyledons earlier than the two Acacia species. Cotyledons were shed off as late as 70 days post‐emergence with 5‐day shedding earlier than 28‐day and cotyledon life‐span decreasing with intensity of defoliation. Shoot apex removal 28‐day resulted in higher compensatory growth than 5‐day in all three species. Cotyledon removal had no effect on shoot length, while shoot apex removal reduced shoot length. In F. albida root growth was stimulated by shoot apex removal. We conclude that potential tolerance to herbivory in terms of seedling survival was of the order A. nilotica > A. nigrescens > F. albida, timing of shoot apex and cotyledon removal influenced seedling growth in terms of biomass and that shoot apex removal stimulated compensatory growth which is critical to seedling survival.
Roadside conditions as predictor for wildlife crossing probability in a Central African rainforest
Authors: Van Der Hoeven Christiaan A. , De Boer Willem F. , Prins Herbert H. T. 
Published: September 2009

AbstractThe negative effects of roads on wildlife in tropical rainforests are poorly understood. Road construction has high priority in Africa, while negative impacts of roads on wildlife movement often are neglected. This study aims at providing information on the effects of roads on crossing behaviour of rainforest wildlife. The probability that wildlife would cross forest roads was analysed for association with ten different factors that were linked to road presence or construction. Factors were divided into three classes: vegetation cover, topography and human influence. A trackplot survey was done in southern Cameroon, Africa. Trackplots were laid along a 32 km unpaved logging road that intersects Campo‐Ma’an National Park. Tracks of several species were found frequently (e.g. genets and porcupines); while others were found only sporadically (e.g. forest duikers and apes). The actual physical obstacles found along the road (e.g. logs, banks, etc.) were highly negatively correlated with crossing probabilities. For all wildlife species high vegetation cover was positively correlated to crossing probability. This study indicates that roads have a large impact on wildlife, and suggests which factors could be altered during road construction and maintenance in order to mitigate these impacts.
Differences in stable isotope composition within and among zooplanktivorous Utaka cichlid populations from Lake Malawi
Authors: Anseeuw Dieter , Guelinckx Jef , Snoeks Jos 
Published: September 2009

AbstractStable isotope analysis was used to determine whether five sympatric zooplanktivorous cichlids of the Utaka assemblage from Lake Malawi vary in isotopic signature as an indication of possible differences in food resource composition. The isotopic composition of the Utaka in combination with literature data about diet composition suggests that these species exploit a narrow range of zooplanktonic prey types. At five sampling locations, significant differences in δ13C and δ15N were detected among species but a consistent pattern across locations was absent. Significant intraspecific differences between locations were found. These differences were relatively low in view of the large geographic distances between the populations and there was no consistent spatial pattern among the species. The observed differences may be indicative of local variations in diet composition, which may help in reducing niche overlap among these zooplanktivores.
Suppression of methanogenesis by dissimilatory Fe(III)‐reducing bacteria in tropical rain forest soils: implications for ecosystem methane flux
Authors: TEH YIT ARN , DUBINSKY ERIC A. , SILVER WHENDEE L. , CARLSON CHARLOTTE M. 
Published: September 2009

AbstractTropical forests are an important source of atmospheric methane (CH4), and recent work suggests that CH4 fluxes from humid tropical environments are driven by variations in CH4 production, rather than by bacterial CH4 oxidation. Competition for acetate between methanogenic archaea and Fe(III)‐reducing bacteria is one of the principal controls on CH4 flux in many Fe‐rich anoxic environments. Upland humid tropical forests are also abundant in Fe and are characterized by high organic matter inputs, steep soil oxygen (O2) gradients, and fluctuating redox conditions, yielding concomitant methanogenesis and bacterial Fe(III) reduction. However, whether Fe(III)‐reducing bacteria coexist with methanogens or competitively suppress methanogenic acetate use in wet tropical soils is uncertain. To address this question, we conducted a process‐based laboratory experiment to determine if competition for acetate between methanogens and Fe(III)‐reducing bacteria influenced CH4 production and C isotope composition in humid tropical forest soils. We collected soils from a poor to moderately drained upland rain forest and incubated them with combinations of 13C‐bicarbonate, 13C‐methyl labeled acetate (13CH3COO−), poorly crystalline Fe(III), or fluoroacetate. CH4 production showed a greater proportional increase than Fe2+ production after competition for acetate was alleviated, suggesting that Fe(III)‐reducing bacteria were suppressing methanogenesis. Methanogenesis increased by approximately 67 times while Fe2+ production only doubled after the addition of 13CH3COO−. Large increases in both CH4 and Fe2+ production also indicate that the two process were acetate limited, suggesting that acetate may be a key substrate for anoxic carbon (C) metabolism in humid tropical forest soils. C isotope analysis suggests that competition for acetate was not the only factor driving CH4 production, as 13C partitioning did not vary significantly between 13CH3COO− and 13CH3COO−+Fe(III) treatments. This suggests that dissimilatory Fe(III)‐reduction suppressed both hydrogenotrophic and aceticlastic methanogenesis. These findings have implications for understanding the CH4 biogeochemistry of highly weathered wet tropical soils, where CH4 efflux is driven largely by CH4 production.
Polymerization stress, flow and dentine bond strength of two resin‐based root canal sealers
Authors: Souza S. F. C. , Bombana A. C. , Francci C. , Gonçalves F. , Castellan C. , Braga R. R. 
Published: September 2009

AbstractAim  To compare two resin‐based root canal sealers (AH Plus and dual cure Epiphany) in terms of flow, polymerization stress and bond strength to dentine.Methodology  Flow was evaluated by measuring the diameter of uncured discs of sealer (0.5 mL) after 7 min compression (20N) between two glass plates (n = 5). Polymerization stress was monitored for 60 min in 1‐mm thick discs bonded to two glass rods (Ø = 5 mm) attached to a universal testing machine (n = 3). Bond strength was analyzed through micropush‐out test (n = 10) and failure mode was examined with scanning electron microscope (100× and 2500×). Data were statistically analyzed using the Student’s t‐test (α = 0.05).Results  Polymerization stress was 0.32 ± 0.07 MPa for Epiphany self‐cure, 0.65 ± 0.08 MPa for Epiphany light‐cure and zero for AH Plus (P < 0.05). Flow data and bond strength values were 30.9 ± 1.1, 28.6 ± 0.7 mm and 6.3 ± 5.3, 17.8 ± 7.5 MPa for Epiphany and AH Plus, respectively (P < 0.001). Failure mode was predominantly cohesive in the sealer for both materials.Conclusions  Epiphany had higher flow and polymerization stress and lower bond strength values to dentine than AH Plus. In view of these findings it can be implied that AH Plus would provide a better seal.
Evaluation of the cost‐effectiveness of root canal treatment using conventional approaches versus replacement with an implant
Authors: Pennington M. W. , Vernazza C. R. , Shackley P. , Armstrong N. T. , Whitworth J. M. , Steele J. G. 
Published: September 2009

AbstractAim To evaluate the cost‐effectiveness of root canal treatment for a maxillary incisor tooth with a pulp infection, in comparison with extraction and replacement with a bridge, denture or implant supported restoration.Methodology A Markov model was built to simulate the lifetime path of restorations placed on the maxillary incisor following the initial treatment decision. It was assumed that the goal of treatment was the preservation of a fixed platform support for a crown without involving the adjacent teeth. Consequently, the model estimates the lifetime costs and the total longevity of toothandimplant supported crowns at the maxillary incisor site. The model considers the initial treatment decisions, and the various subsequent treatment decisions that might be taken if initial restorations fail.Results Root canal treatment extended the life of the tooth at an additional cost of £5–8 per year of tooth life. Provision of orthograde re‐treatment, if the root canal treatment fails returns further extension of the expected life of the tooth at a cost of £12–15 per year. Surgical re‐treatment is not cost‐effective; it is cheaper, per year, to extend the life of the crown by replacement with a single implant restoration if orthograde endodontic treatment fails.Conclusion Modelling the available clinical and cost data indicates that, root canal treatment is highly cost‐effective as a first line intervention. Orthograde re‐treatment is also cost‐effective, if a root treatment subsequently fails, but surgical re‐treatment is not. Implants may have a role as a third line intervention if re‐treatment fails.
An in vivo experimental model to assess furcal lesions as a result of perforation
Authors: Silva M. J. B. , Caliari M. V. , Sobrinho A. P. R. , Vieira L. Q. , Arantes R. M. E. 
Published: September 2009

AbstractAim  To design and validate a rat molar model of furcal perforation to allow investigation of the biological phenomena that follow and to explore its potential for evaluating repair materials under standardized conditions.Methodology  Eighteen male Wistar rats were used. Surgical aseptic procedures were carried out in order to open the pulp chamber of a first molar tooth. A cavity was prepared on the floor of the pulp chamber using a ¼ round bur that created a communication between the furcation and the periodontal tissues. Six animals for each time point were sacrificed on days 14, 21 and 28 to assay morphological changes at the furcation region of molars. Maxillary bone was processed, removed and sectioned. Cellular infiltration, collagen deposition and bone resorption were assessed by histological analysis. Cellularity in the lesion area was determined by morphometric analysis. Data were analysed using parametric Student’s t‐test.Results  A furcal perforation model was standardized in which both radiological outcome and periodontal tissue reactions could be assessed through evaluation of cellularity, osteoclast activity and collagen deposition. The morphometric analysis revealed a greater number of cells 21 day post‐surgery when compared with 14 days.Conclusion  This animal model was suitable for radiological and histological evaluation of the processes that accompany surgical furcal perforation.
The morphology of the apical foramen in posterior teeth in a North Indian population
Authors: Arora S. , Tewari S. 
Published: September 2009

AbstractAim  To determine the position and shape of the apical foramina in posterior teeth derived from an Indian population.Methodology  A total of 800 freshly extracted maxillary and mandibular premolar and molar teeth from a native Haryana population were collected. Apices of teeth were stained with methylene blue and then examined stereomicroscopically (40×). The following observations were made: number of apical foramina; size and shape of the minor apical foramen; accessory foramina frequency, and deviation of the minor apical foramina (frequency and distance) from the apex.Results  The mean maximum and minimum diameter of the minor apical foramina ranged from 0.158 to 0.323 mm. The most common minor apical foramen shape was oval (81%). Frequency of accessory foramina was between 2% and 41% for the various tooth types. The frequency of deviation of the minor apical foramina from the anatomic apex varied from 43% to 83% and the distance of deviation in all the teeth was between 0.052 and 2.921 mm.Conclusions  The incidence of oval canals was higher in this Indian population compared to other populations. In 92% and 96% of teeth the difference between the maximum and the minimum diameter of all foramina was less than or equal to 0.20 and 0.25 mm, respectively. Therefore, four to five instrument sizes larger than the first binding file would have been necessary to shape the minor apical foramen of more than 95% of the teeth included in this study to make them round.
Carbon dioxide laser irradiation stimulates mineralization in rat dental pulp cells
Authors: Yasuda Y. , Ohtomo E. , Tsukuba T. , Okamoto K. , Saito T. 
Published: September 2009

AbstractAim  To examine the effect of carbon dioxide laser irradiation on mineralization in dental pulp cells.Methodology  Rat dental pulp cells were irradiated with a carbon dioxide laser at 2 W output power for 20, 40 and 60 s, and were cultured in ascorbic acid and β‐glycerophosphate containing media. Cell viability was examined 24 h after laser irradiation by a modified MTT assay. Alizarin Red S staining was performed 10 days after laser irradiation. The amounts of secreted collagen from the cells after irradiation were quantified following Sirius Red staining. The expression levels of collagen type I and HSP47, collagen‐binding stress protein, were analysed by real‐time PCR. HSP47 protein expression was examined by Western blotting. Statistical analysis was performed using one‐way analysis of variance (anova) followed by the Tukey’s multiple comparison test.Results  The cell viability was not affected by laser irradiation at 2 W for up to 40 s. However, it was significantly decreased by 20% at 60 s (P < 0.05). The amount of mineralization after 10 days of irradiation at 2 W for 40 s was significantly increased in comparison to the other conditions (P < 0.05). The extracellular collagen production was significantly increased by 73% on day 2 and 38% on day 4 after laser irradiation (P < 0.05). Although collagen type I gene expression was not changed by laser irradiation, HSP47 gene and protein expression was induced within 12 and 24 h, respectively.Conclusions  These results suggested that carbon dioxide laser irradiation stimulated mineralization in dental pulp cells. The laser irradiation also increased HSP47 expression but not collagen gene expression.
The health of children with cerebral palsy and stress in their parents
Authors: Parkes Jackie , McCullough Nichola , Madden Ann , McCahey Elaine 
Published: September 2009

AbstractTitle.  The health of children with cerebral palsy and stress in their parents. Aim.  This paper is a report of a study conducted to describe the health of children with cerebral palsy and investigate predictors of stress in their parents.Background.  Children with severe cerebral palsy tend to have poorer health than their able‐bodied peers, and their parents are more likely to be stressed and have poorer health.Method.  A cross‐sectional survey with home visits using standard questionnaires was administered to parents in 2004–05. A total of 102/199 (51%) children and parents participated. The children were compared with a normative sample.Results.  Children with cerebral palsy had poorer physical health, and 79% of parents reported that their child had moderate to severe pain. Their poorer health, in comparison with the normal sample and measured by the Child Health Questionnaire, was related to feeding problems and seizures, general health perceptions to intellectual and feeding impairment, and family activities with severe motor, intellectual and feeding impairment. Poorer psychological well‐being on the hyperactivity domain of the Strengths & Difficulties Questionnaire was related to feeding difficulties, on the prosocial domain to more severe forms of all child impairments, and on the social impairment scale to intellectual impairment. Children with psychological problems had statistically significantly increased odds (OR = 7·2, 95% CIs 2·6–20·3) of having parents with high stress.Conclusion.  Children with cerebral palsy and associated impairments are at higher risk of poorer health and family well‐being. A family‐centred approach to the care of children with cerebral palsy and their families is essential to ensure both receive adequate care and support.
Variations in nursing care quality across hospitals
Authors: Lucero Robert J. , Lake Eileen T. , Aiken Linda H. 
Published: September 2009

AbstractTitle.  Variations in nursing care quality across hospitals. Aims.  The aim of the study was to describe Registered Nurses’ reports of unmet nursing care needs and examine the variation of nursing care quality across hospitals.Background.  Large proportions of Registered Nurses have reported leaving necessary care activities undone because they lacked the time to complete the activities. Nursing care left undone can be expected to adversely affect the quality of care. However, little is known about the degree of variation in the quality of nursing care across hospitals.Methods.  In 2008, a secondary analysis of a 1999 survey of Registered Nurses (n = 10,184) was conducted using descriptive and comparative statistics. Data were derived from inpatient staff nurses working in acute care hospital settings (n = 168). A hospital‐level measure (i.e. unmet nursing care needs) of the quality of nursing care was developed from care needs left undone among all nurses.Results.  Across hospitals there was a wide range in the proportion of Registered Nurses who reported leaving each nursing care need undone. They reported leaving two of seven necessary nursing care activities undone during their last shift. After controlling for nurses’ demographic information, we found statistically significant variations in the quality of nursing care across hospitals.Conclusion.  Differences in nursing care quality across hospitals appear to be closely associated with variations in the quality of care environments. Understanding the determinants of unmet nursing care needs can support policy decisions on systems and human resources management to enhance nurses’ awareness of their care practices and the care environment.
Expert nursing practice: a mathematical explanation of Benner’s 5th stage of practice development
Authors: Lyneham Joy , Parkinson Camillus , Denholm Carey 
Published: September 2009

AbstractTitle. Expert nursing practice: a mathematical explanation of Benner’s 5th stage of practice development.Aim. This paper is a theoretical discussion of a mathematical explanation for Benner’s theory of practice development.Background. Benner’s practice development theory demonstrates how a nurse moves from a beginning, rule‐based practice through to expert care. Her notion of expert practice as intuitive has not been well‐accepted or understood in nursing. A new description of expert practice includes three types of intuitive practice (cognitive, transitional and embodied), the development of which are dependent on knowledge, experience and reflective time.Data sources. This paper is based on phenomenological research conducted in 2000–2003 and Benner’s publications, as well as recent discussions about the relationship between mathematics and phenomenology.Discussion. The mathematical explanation for Benner’s theory of practice development relates reflective time and knowledge to the mathematical power of experience and links the unique components of intuitive practice to expert care. On reaching expert practice, the three types of intuition include previously identified themes (knowledge, experience, connection, feeling, syncretism and trust) as differentials along the reflective time axis. When graphically represented, expert practice becomes a three‐dimensional figure as practice becomes more complex, rather than a two‐dimensional one as seen in previous stages.Conclusion. Having the intuitive component of expert practice further clarified from Benner’s first vision confirms it as a valid component of practice. It is important to recognize that experience is a powerful component of practice and that it is essential to the development of expertise. Although this discussion has been nested within nursing practice, it has wide implications for medical, psychological and educational practice.