bluuebunny/crossref_metadata_2025 huggingface dataset:
The Determinant of Potyvirus Ability to Overcome the RTM Resistance of Arabidopsis thaliana Maps to the N-Terminal Region of the Coat Protein
Authors: Decroocq V. , Salvador B. , Sicard O. , Glasa M. , Cosson P. , Svanella-Dumas L. , Revers F. , García J. A. , Candresse T.
Published: September 2009

In Arabidopsis thaliana Columbia (Col-0) plants, the restriction of Tobacco etch virus (TEV) long-distance movement involves at least three dominant RTM (restricted TEV movement) genes named RTM1, RTM2, and RTM3. Previous work has established that, while the RTM-mediated resistance is also effective against other potyviruses, such as Plum pox virus (PPV) and Lettuce mosaic virus (LMV), some isolates of these viruses are able to overcome the RTM mechanism. In order to identify the viral determinant of this RTM-resistance breaking, the biological properties of recombinants between PPV-R, which systemically infects Col-0, and PPV-PSes, restricted by the RTM resistance, were evaluated. Recombinants that contain the PPV-R coat protein (CP) sequence in an RTM-restricted background are able to systemically infect Col-0. The use of recombinants carrying chimeric CP genes indicated that one or more PPV resistance-breaking determinants map to the 5′ half of the CP gene. In the case of LMV, sequencing of independent RTM-breaking variants recovered after serial passages of the LMV AF199 isolate on Col-0 plants revealed, in each case, amino acid changes in the CP N-terminal region, close to the DAG motif. Taken together, these findings demonstrate that the potyvirus CP N-terminal region determines the outcome of the interaction with the RTM-mediated resistance.
The Influence of RNA-Dependent RNA Polymerase 1 on Potato virus Y Infection and on Other Antiviral Response Genes
Authors: Rakhshandehroo Farshad , Takeshita Minoru , Squires Julie , Palukaitis Peter
Published: September 2009

The gene encoding RNA-dependent RNA polymerase 1 (RDR1) is involved in basal resistance to several viruses. Expression of the RDR1 gene also is induced in resistance to Tobacco mosaic virus (TMV) mediated by the N gene in tobacco (Nicotiana tabacum cv. Samsun NN) in an incompatible hypersensitive response, as well as in a compatible response against Potato virus Y (PVY). Reducing the accumulation of NtRDR1 transcripts by RNA inhibition mediated by transgenic expression of a double-stranded RNA hairpin corresponding to part of the RDR1 gene resulted in little or no induction of accumulation of RDR1 transcripts after infection by PVY. Plants with lower accumulation of RDR1 transcripts showed much higher accumulation levels of PVY. Reduced accumulation of NtRDR1 transcripts also resulted in lower or no induced expression of three other antiviral, defense-related genes after infection by PVY. These genes encoded a mitochondrial alternative oxidase, an inhibitor of virus replication (IVR), and a transcription factor, ERF5, all involved in resistance to infection by TMV, as well as RDR6, involved in RNA silencing. The extent of the effect on the induced NtIVR and NtERF5 genes correlated with the extent of suppression of the NtRDR1 gene.
Reconsidering the Division of Household Labor: Incorporating Volunteer Work and Informal Support
Authors: L. Hook Jennifer
Published: September 2009

The gendered division of household labor is more multifaceted than the allocation of paid work and domestic work. People also engage in volunteer work and informal support. I investigate the applicability of household labor allocation theories—specifically the time constraints, economic, and “doing gender” perspectives—to all unpaid work. I analyze the 1997 Australian Time Use Survey diaries of 1,797 married couples using logistic, ordinary least squares, and seemingly unrelated regressions. Analyses show that volunteer work and support work are substantial expenditures associated with paid work and housework, but they do not create a “third shift.” Volunteer work and support work are part of the gendered household labor allocation process determined, in part, by time constraints and by gender.
The Power of Older Women and Men in Egyptian and Tunisian Families
Authors: Yount Kathryn M. , Agree Emily M.
Published: September 2009

We adapt resource theory to compare involvement in family decisions by older women and men in the more patriarchal setting of Egypt and the more egalitarian setting of Tunisia. Data from the World Health Organization Collaborative Study on Social and Health Aspects of Aging are analyzed. In Egypt, women participate less often than men in most decisions, whereas participation is more gender equitable in Tunisia. Increasing age and declining health are negatively associated with participation in daily and life course decisions, particularly for Egyptian women. Although women participate less often than men in life course decisions in Egypt, involvement is more frequent among widows and those owning their homes. Future research should examine the relationship of resources, support, and the family power of older adults across normative contexts.
Parenting Practices as Moderators of the Relationship Between Peers and Adolescent Marijuana Use
Authors: Dorius Cassandra J. , Bahr Stephen J. , Hoffmann John P. , Harmon Elizabeth Lovelady
Published: September 2009

Using data from a probability sample of 4,987 adolescents, we examine the degree to which closeness to mother, closeness to father, parental support, and parental monitoring buffer the relationship between peer drug use and adolescent marijuana use. The relationship between peer drug use and adolescent marijuana use was attenuated by both closeness to father and the perception that parents would catch them for major rule violations. These findings confirm the value of conceptualizing certain family characteristics as separate variables and verify that authoritative parenting may help insulate adolescents from peer pressure to use drugs.
Welfare Reform and Teenage Pregnancy, Childbirth, and School Dropout
Authors: Hao Lingxin , Cherlin Andrew J.
Published: September 2009

This study estimates the effect of welfare reform on adolescent behaviors using a difference‐in‐differences approach. After defining the prereform and reform cohorts and considering the life course development of adolescent behavior by following each cohort from age 14 to age 16, we compare the welfare‐target and nontarget populations in the two cohorts. The difference‐in‐differences estimates are obtained using an event history model. Our analysis suggests that welfare reform has not reduced teenage fertility and school dropout. We find modest evidence that welfare reform is associated with higher risk of teenage births for girls in welfare families and higher risk of school dropout for girls in poor families. A combination of a difference‐in‐differences approach and a life course perspective can be a useful way to delineate the effect of societal‐level change on family phenomena.
Cohabitation and Children's Family Instability
Authors: Kelly Raley R. , Wildsmith Elizabeth
Published: September 2009

This study estimates how much children's family instability is missed when we do not count transitions into and out of cohabitation, and examines early life course trajectories of children to see whether children who experience maternal cohabitation face more family instability than children who do not. Using data from the 1995 National Survey of Family Growth, analyses show that adding transitions into and out of cohabitation to those into and out of marriage increases our measure of family instability by about 30% for White children (N = 1575) and over 100% for Black children (N = 774). We conclude that future research on the impact of children's family composition while growing up should take into account transitions into and out of cohabitation.
Information and Communications Technology and Auditing: Current Implications and Future Directions
Authors: Omoteso Kamil , Patel Ashok , Scott Peter
Published: September 2009

This exploratory study assesses, from a structuration theory perspective, the impact information and communications technology (ICT) tools and techniques are currently having on audit tasks, auditors (internal and external) and the organisations they work for from the point of view of coordination, control, authority and structure. Based on a triangulation of interview and questionnaire techniques, the findings indicate that ICT is re‐shaping auditors' roles and outputs as well as audit organisations' structures. The findings also project the view that continuous auditing, artificial intelligence and CobiT are expected to gain more prominence while a need was also seen for new software development to help auditors match the complexity of their clients' information systems. The study's results reveal the current state of affairs of the relationship between ICT and auditing against the backdrop of continuous global ICT sophistication thereby updating ICT audit literature and the likely future direction of this relationship.
The carboxy‐terminal tail of Aeromonas sobria serine protease is associated with the chaperone
Authors: Kobayashi Hidetomo , Tateishi Arisa , Tsuge Hideaki , Takahashi Eizo , Okamoto Keinosuke , Yamanaka Hiroyasu
Published: September 2009

ASP is the only bacterial protease in the kexin group of the subtilisin family. Previous studies have revealed that the ORF2 protein encoded at the 3′ end of the asp operon is required for ASP to change from a nascent form into an active form in the periplasm. However, the mechanism by which ORF2 makes contact and interacts with ASP in the maturation process remains unknown. The present study examined the effect of mutations in the carboxy‐terminal region of ASP on the ASP maturation process. Both deletion‐mutation and amino acid‐substitution studies have demonstrated that the histidine residue at position 595 (His‐595), the sixth residue from the carboxyl terminus of ASP, is highly involved in the generation of active ASP molecules. An analysis by pull‐down assay revealed that mutation at His‐595 reduces the efficacy of nascent ASP to transition into active ASP by reducing the ability of ASP to make contact and interact with ORF2. Thus, it appears likely that nascent ASP in the periplasm interacts with ORF2 via the carboxy‐terminal region, and His‐595 of ASP appears to be an indispensable residue in this interaction.
Suppression of gastric cancer dissemination by ephrin‐B1‐derived peptide
Authors: Tanaka Masamitsu , Kamata Reiko , Yanagihara Kazuyoshi , Sakai Ryuichi
Published: September 2009

Interaction of the Eph family of receptor protein tyrosine kinases and their ligands, ephrin family members, induces bidirectional signaling through cell–cell contacts. High expression of B‐type ephrin is associated with high invasion potential of tumors, and we previously observed that signaling through the C‐terminus of ephrin‐B1 mediates the migration and invasion of cells, and is involved in the promotion of carcinomatous peritonitis in vivo. Here we show that the intracellular introduction of a synthetic peptide derived from ephrin‐B1 C‐terminus blocks ephrin‐B1 mediated signaling in scirrhous gastric cancer cells. Treatment of cancer cells with a fusion peptide consisting of HIV‐TAT and amino acids 331–346 of ephrin‐B1 (PTD‐EFNB1‐C) suppressed the activation of RhoA, mediated by the association of ephrin‐B1 with an adaptor protein Dishevelled, and also inhibited extracellular secretion of metalloproteinase. Moreover, injection of PTD‐EFNB1‐C peptide into the peritoneal cavity of nude mice suppressed carcinomatous peritonitis of intraperitoneally transplanted scirrhous gastric cancer cells. These results indicate the possible application of ephrin‐B1 C‐terminal peptide to develop novel protein therapy for scirrhous gastric carcinoma, especially in the stage of tumor progression, including peritoneal dissemination. (Cancer Sci 2009)
Expression of thioredoxin during progression of hamster and human cholangiocarcinoma
Authors: Yoon Byung‐Il , Kim Yeong‐Hun , Yi Jung‐Yeon , Kang Min‐Soo , Jang Ja‐June , Joo Kyoung‐Hwan , Kim Yongbaek , McHugh Law J. , Kim Dae‐Yong
Published: September 2009

Thioredoxin (Trx) is a multifunctional redox protein that has growth‐promoting and anti‐apoptotic effects on cells and protects cells from endogenous and exogenous free radicals. Recently, altered expression of Trx has been reported in various cancers. In the present study, we investigated altered expression of Trx at the precancerous and carcinogenic phases during cholangiocarcinogenesis in a hamster cholangiocarcinoma (ChC) model, using semiquantitative immunohistochemical and Western blot analyses. Moreover, to determine if the results correlated well with those in human ChCs, we carried out a comparative immunohistochemical study for Trx in tissue‐arrayed human ChCs with different grades of tumor cell differentiation. Trx was found highly expressed in the cytoplasm of dysplastic bile ducts with highly abnormal growth patterns and ChCs irrespective of tumor type or tumor cell differentiation. Overexpression of Trx at the precancerous and carcinogenic phases was further supported by significant elevation of Trx protein in Western blotting. The results from the hamster ChCs were in good agreement with those from human ChCs. Our results strongly suggested that the redox regulatory function of Trx plays an important role in bile duct cell transformation and tumor progression during cholangiocarcinogenesis. (Cancer Sci 2009)
Susceptibility of human T‐cell leukemia virus type I‐infected cells to humanized anti‐CD30 monoclonal antibodies in vitro and in vivo
Authors: Maeda Naoyoshi , Muta Hiromi , Oflazoglu Ezogelin , Yoshikai Yasunobu
Published: September 2009

Adult T‐cell leukemia (ATL) is an aggressive malignancy of activated CD4+ T cells associated with human T‐cell leukemia virus type I (HTLV‐I) infection. No conventional chemotherapy regimen has appeared successful in patients with ATL, thus establishing effective therapy is urgently required. In some cases, ATL tumor cells express CD30 on the cell surface, therefore, a therapy with mAb against CD30 would be beneficial. To investigate the effect of CD30‐mediated therapy on ATL, we assessed SGN‐30, a chimeric anti‐CD30 mAb, and SGN‐35, a monomethyl auristatin E‐conjugated anti‐CD30 mAb, in vitro and in vivo. Three HTLV‐I‐infected cell lines were co‐cultured with SGN‐30 or SGN‐35, and the growth‐inhibitory effects on the HTLV‐I‐infected cells were evaluated using an in vitro cell proliferation assay and cell cycle analysis. SGN‐30 and SGN‐35 showed growth‐inhibitory activity against the HTLV‐I‐infected cell lines by apoptosis and/or cell growth arrest in vitro. To further investigate the effects of SGN‐30 and SGN‐35 on HTLV‐I‐infected cells in vivo, we used NOD/SCID mice subcutaneously engrafted with HTLV‐I‐infected cells. Both mAbs significantly inhibited the growth of HTLV‐I‐infected cell tumors in the NOD/SCID murine xenograft models. These data suggest that CD30‐mediated therapy with SGN‐30 or SGN‐35 would be useful for patients with ATL. (Cancer Sci 2009)
Preventing heavy alcohol use in adolescents (PAS): cluster randomized trial of a parent and student intervention offered separately and simultaneously
Authors: Koning Ina M. , Vollebergh Wilma A. M. , Smit Filip , Verdurmen Jacqueline E. E. , Van Den Eijnden Regina J. J. M. , Ter Bogt Tom F. M. , Stattin Håkan , Engels Rutger C. M. E.
Published: September 2009

Aims  To evaluate the effectiveness of two preventive interventions to reduce heavy drinking in first‐ and second‐year high school students.

Design and setting  Cluster randomized controlled trial using four conditions for comparing two active interventions with a control group from 152 classes of 19 high schools in the Netherlands.

Participants  A total of 3490 first‐year high school students (mean 12.68 years, SD = 0.51) and their parents.

Intervention conditions  (i) Parent intervention (modelled on the Swedish Örebro Prevention Program) aimed at encouraging parental rule‐setting concerning their children's alcohol consumption; (ii) student intervention consisting of four digital lessons based on the principles of the theory of planned behaviour and social cognitive theory; (iii) interventions 1 and 2 combined; and (iv) the regular curriculum as control condition.

Main outcome measures  Incidence of (heavy) weekly alcohol use and frequency of monthly drinking at 10 and 22 months after baseline measurement.

Findings  A total of 2937 students were eligible for analyses in this study. At first follow‐up, only the combined student–parent intervention showed substantial and statistically significant effects on heavy weekly drinking, weekly drinking and frequency of drinking. At second follow‐up these results were replicated, except for the effects of the combined intervention on heavy weekly drinking. These findings were consistent across intention‐to‐treat and completers‐only analyses.

Conclusions  Results suggest that adolescents as well as their parents should be targeted in order to delay the onset of drinking, preferably prior to onset of weekly drinking.
Interplay of genetic risk factors and parent monitoring in risk for nicotine dependence
Authors: Chen Li‐Shiun , Johnson Eric O. , Breslau Naomi , Hatsukami Dorothy , Saccone Nancy L. , Grucza Richard A. , Wang Jen C. , Hinrichs Anthony L. , Fox Louis , Goate Alison M. , Rice John P. , Bierut Laura J.
Published: September 2009

Background  Several studies have found replicable associations between nicotine dependence and specific variants in the nicotinic receptor genes CHRNA5(rs16969968) and CHRNA3(rs3743078). How these newly identified genetic risks combine with known environmental risks is unknown. This study examined whether the level of parent monitoring during early adolescence modified the risk of nicotine dependence associated with these genetic variants.

Methods  In a cross‐sectional case–control study of US‐based community sample of 2027 subjects, we use a systematic series of regression models to examine the effect of parent monitoring on risk associated with two distinct variants in the nicotinic receptor genes CHRNA5(rs16969968) and CHRNA3(rs3743078).

Results  Low parent monitoring as well as the previously identified genetic variants were associated with an increased risk of nicotine dependence. An interaction was found between the SNP(rs16969968) and parent monitoring (P = 0.034). The risk for nicotine dependence increased significantly with the risk genotype of SNP(rs16969968) when combined with lowest‐quartile parent monitoring. In contrast, there was no evidence of an interaction between SNP(rs3743078) and parent monitoring (P = 0.80).

Conclusions  The genetic risk of nicotine dependence associated with rs16969968 was modified by level of parent monitoring, while the genetic risk associated with rs3743078 was not, suggesting that the increased risk due to some genes may be mitigated by environmental factors such as parent monitoring.
Legislation to institutionalize resources for tobacco control: the 1987 Victorian Tobacco Act
Authors: Borland Ron , Winstanley Margaret , Reading Dorothy
Published: September 2009

Aim  To describe the process surrounding the creation of the first organization in the world to be funded from an earmarked tax on tobacco products, the Victorian Health Promotion Foundation (VicHealth), and to outline briefly its subsequent history.

Description  The genesis of VicHealth came from an interest of the Minister for Health in the Victorian State Government to address the tobacco problem, and the strategic capacity of Dr Nigel Gray from the Anti‐Cancer Council of Victoria to provide a vehicle and help the government to muster support for its implementation. Success involved working with government to construct a Bill it was happy with and then working with the community to support the implementation and to counter industry attempts to derail it. The successful Bill led to the creation of VicHealth. VicHealth has played a creative and important role in promoting health not only in Victoria (Australia), but has been a stimulus for similar initiatives in other parts of the world.

Conclusions  Enacting novel advances in public policy is made easier when there is a creative alliance between advocates outside government working closely with governments to develop a proposal that is politically achievable and then to work together to sell it. Health promotion agencies, once established, can play an important role in advancing issues like tobacco control.
Microarray analysis and functional tests suggest the involvement of expansins in the early stages of symbiosis of the arbuscular mycorrhizal fungus Glomus intraradices on tomato (Solanum lycopersicum)
Authors: DERMATSEV VLADIMIR , WEINGARTEN‐BAROR CARMIYA , RESNICK NATHALIE , GADKAR VIJAY , WININGER SMADAR , KOLOTILIN IGOR , MAYZLISH‐GATI EINAV , ZILBERSTEIN AVIA , KOLTAI HINANIT , KAPULNIK YORAM
Published: September 2009

Arbuscular mycorrhizal (AM) symbiosis occurs between fungi of the phylum Glomeromycota and most terrestrial plants. However, little is known about the molecular symbiotic signalling between AM fungi (AMFs) and non‐leguminous plant species. We sought to further elucidate the molecular events occurring in tomato, a non‐leguminous host plant, during the early, pre‐symbiotic stage of AM symbiosis, i.e. immediately before and after contact between the AMF (Glomus intraradices) and the host. We adopted a semi‐synchronized AMF root infection protocol, followed by genomic‐scale, microarray‐based, gene expression profiling at several defined time points during pre‐symbiotic AM stages. The microarray results suggested differences in the number of differentially expressed genes and in the differential regulation of several functional groups of genes at the different time points examined. The microarray results were validated and one of the genes induced during contact between AMF and tomato, the expansin‐like EXLB1, was functionally analysed. Expansins, encoded by a large multigene family, facilitate plant cell expansion. However, no biological or biochemical function has yet been established for plant‐originated expansin‐like proteins. EXLB1 transcripts were localized early during the association to cells that may perceive the fungal signal, and later during the association in close proximity to sites of AMF hypha–root colonization. Moreover, in transgenic roots, we demonstrated that a reduction in the steady‐state level of EXLB1 transcript was correlated with a reduced rate of infection, reduced arbuscule expansion and reduced AMF spore formation.
Aboveground biomass estimation of the shrubs, Echiochilon fruticosum (Desf.) and Helianthemum kahiricum (Del.) in the arid zone rangelands of Tunisia
Authors: Idi Abdelkader , Ali Ferchichi , Mohamed Chaieb
Published: September 2009

The knowledge of the plant biomass is very important for the assessment of the rangeland productivity. It could help to select the appropriate species for the improvement of natural ecosystems (rehabilitation, restoration and seedling). By examining different correlations between the biomass production and the volume parameters of two North African shrub species of high range value (Echiochilon fruticosum Desf. and Helianthemum kahiricum Del.), we aimed to establish the appropriate regression models, which could be useful for the prediction of the productivity of these species. The data showed a significant relationship between the total biomass (TB) production and the mean diameter (MD) of the studied species (R2 = 0.65 for Echiochilon and R2 = 0.75 for Helianthemum). Likewise, annual fresh production (leaves and current‐year shoots) was well correlated with MD of Helianthemum (R2 = 0.82). However, the correlation between these two parameters was relatively low for Echiochilon (R2 = 0.42).
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

Browsing 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

Woody 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

The 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

Stable 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

Tropical 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

Aim  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

Aim 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

Aim  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

Aim  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

Aim  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

Title.  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

Title.  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

Title. 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.
Hope, self‐efficacy, spiritual well‐being and job satisfaction
Authors: Duggleby Wendy , Cooper Dan , Penz Kelly
Published: September 2009

Title.  Hope, self‐efficacy, spiritual well‐being and job satisfaction.

Aim.  This paper is a report of a study of the relations of spiritual well‐being, global job satisfaction, and general self‐efficacy to hope in Continuing Care Assistants.

Background.  Healthcare providers have described their hope as an important part of their work and a form of work motivation. Hope may be an important factor in preventing burnout and improving job satisfaction.

Methods.  A concurrent triangulation mixed method design was used. Sixty‐four Continuing Care Assistants (personal care aides) who registered for a ‘Living with Hope’ Conference completed a demographic form, Herth Hope Index, Global Job Satisfaction Questionnaire, Spiritual Well‐Being Scale, General Self‐Efficacy Scale, and a hope questionnaire. Data were collected in 2007. The response rate was 58%.

Results.  Using linear regression, 29·9% of the variance in Herth Hope Index score was accounted for by scores from the General Self‐Efficacy Scale and Spiritual Well‐Being Scale. General Self‐efficacy scores (positive relationship) and Spiritual Well‐Being scores (negative relationship) accounted for a significant part of the variance. Qualitative data supported all findings, with the exception of the negative relationship between hope and spiritual well‐being; participants wrote that faith, relationships, helping others and positive thinking helped them to have hope. They also wrote that hope had a positive influence on their job satisfaction and performance.

Conclusion.  Hope is an important concept in the work life of Continuing Care Assistants. Supportive relationships, adequate resources, encouragement by others, and improving perceptions of self‐efficacy (ability to achieve goals in their workplace) may foster their hope.