bluuebunny/crossref_metadata_2025 huggingface dataset:
Stimulation of the CLIP-170–dependent capture of membrane organelles by microtubules through fine tuning of microtubule assembly dynamics
Authors: Lomakin Alexis J. , Kraikivski Pavel , Semenova Irina , Ikeda Kazuho , Zaliapin Ilya , Tirnauer Jennifer S. , Akhmanova Anna , Rodionov Vladimir
Published: September 2011

Cytoplasmic microtubules (MTs) continuously grow and shorten at their free plus ends, a behavior that allows them to capture membrane organelles destined for MT minus end–directed transport. In Xenopus melanophores, the capture of pigment granules (melanosomes) involves the +TIP CLIP-170, which is enriched at growing MT plus ends. Here we used Xenopus melanophores to test whether signals that stimulate minus end MT transport also enhance CLIP-170–dependent binding of melanosomes to MT tips. We found that these signals significantly (>twofold) increased the number of growing MT plus ends and their density at the cell periphery, thereby enhancing the likelihood of interaction with dispersed melanosomes. Computational simulations showed that local and global increases in the density of CLIP-170–decorated MT plus ends could reduce the half-time of melanosome aggregation by ∼50%. We conclude that pigment granule aggregation signals in melanophores stimulate MT minus end–directed transport by the increasing number of growing MT plus ends decorated with CLIP-170 and redistributing these ends to more efficiently capture melanosomes throughout the cytoplasm.
Nuclear transporters in a multinucleated organism: functional and localization analyses in Aspergillus nidulans
Authors: Markina-Iñarrairaegui Ane , Etxebeste Oier , Herrero-García Erika , Araújo-Bazán Lidia , Fernández-Martínez Javier , Flores Jairo A. , Osmani Stephen A. , Espeso Eduardo A.
Published: September 2011

Nuclear transporters mediate bidirectional macromolecule traffic through the nuclear pore complex (NPC), thus participating in vital processes of eukaryotic cells. A systematic functional analysis in Aspergillus nidulans permitted the identification of 4 essential nuclear transport pathways of a hypothetical number of 14. The absence of phenotypes for most deletants indicates redundant roles for these nuclear receptors. Subcellular distribution studies of these carriers show three main distributions: nuclear, nucleocytoplasmic, and in association with the nuclear envelope. These locations are not specific to predicted roles as exportins or importins but indicate that bidirectional transport may occur coordinately in all nuclei of a syncytium. Coinciding with mitotic NPC rearrangements, transporters dynamically modified their localizations, suggesting supplementary roles to nucleocytoplasmic transport specifically during mitosis. Loss of transportin-SR and Mex/TAP from the nuclear envelope indicates absence of RNA transport during the partially open mitosis of Aspergillus, whereas nucleolar accumulation of Kap121 and Kap123 homologues suggests a role in nucleolar disassembly. This work provides new insight into the roles of nuclear transporters and opens an avenue for future studies of the molecular mechanisms of transport among nuclei within a common cytoplasm, using A. nidulans as a model organism.
Effects of Ostracism and Social Connection-Related Activities on Adolescents' Motivation to Eat and Energy Intake
Authors: Salvy Sarah-Jeanne , Bowker Julie C. , Nitecki Lauren A. , Kluczynski Melissa A. , Germeroth Lisa J. , Roemmich James N.
Published: September 2011

Objective Assess the effect of ostracism and social connection-related activities on adolescents' motivation to eat and their energy intake. Methods Participants (n = 103;M age = 13.6 years) were either ostracized or included when playing a computer game, Cyberball. Next, they wrote about their friend (social-connection), watched television (distraction), or completed Sudoku puzzles (cognitive-load), and then completed a task to earn points toward snack food and/or socializing. Afterwards, participants were given access to food and social activities. Results Ostracized adolescents were more motivated to earn food than adolescents who were in the included/control condition. Follow-up contrasts indicated that ostracized adolescents who wrote about friends worked more for food points and consumed more food than other adolescents. Conclusion Results suggest that social connection-related activities following ostracism may further deplete self-regulatory resources, thereby resulting in increased unhealthy food patterns. Study limitations as well as clinical implications of these findings are discussed.
Adaptive evolution of sexual systems in pedunculate barnacles
Authors: Yusa Yoichi , Yoshikawa Mai , Kitaura Jun , Kawane Masako , Ozaki Yuki , Yamato Shigeyuki , Høeg Jens T.
Published: September 2011

How and why diverse sexual systems evolve are fascinating evolutionary questions, but few empirical studies have dealt with these questions in animals. Pedunculate (gooseneck) barnacles show such diversity, including simultaneous hermaphroditism, coexistence of dwarf males and hermaphrodites (androdioecy), and coexistence of dwarf males and females (dioecy). Here, we report the first phylogenetically controlled test of the hypothesis that the ultimate cause of the diverse sexual systems and presence of dwarf males in this group is limited mating opportunities for non-dwarf individuals, owing to mating in small groups. Within the pedunculate barnacle phylogeny, dwarf males and females have evolved repeatedly. Females are more likely to evolve in androdioecious than hermaphroditic populations, suggesting that evolution of dwarf males has preceded that of females in pedunculates. Both dwarf males and females are associated with a higher proportion of solitary individuals in the population, corroborating the hypothesis that limited mating opportunities have favoured evolution of these diverse sexual systems, which have puzzled biologists since Darwin.
Communication gaps in knowledge of freshwater fish biodiversity: implications for the management and conservation of Mexican biosphere reserves
Authors: Pino‐Del‐Carpio A. , Villarroya A. , Ariño A. H. , Puig J. , Miranda R.
Published: September 2011

To detect differences in the information available on freshwater fish species found in Mexican biosphere reserves, the number of species considered in three sources of information: management programmes, Global Biodiversity Information Facility (GBIF) and the scientific literature were compared. Additionally, management actions for the reserves were evaluated. More than 55% of freshwater fish species registered for the reserves were found only in one of the three sources of information, while just 12% was shared among all the three. Fifteen threatened species were registered in GBIF and the scientific literature that were not found in management programmes. Although all the management programmes described conservation actions, none of them gave details about how they would be implemented. Lack of communication among the sources studied, unawareness of the existence of threatened species and the absence of detailed management actions hinder the development of adequate conservation strategies.
miR‐92 is a key oncogenic component of the miR‐17–92 cluster in colon cancer
Authors: Tsuchida Akihiko , Ohno Shinichiro , Wu Weihong , Borjigin Nariso , Fujita Koji , Aoki Tastuya , Ueda Shinobu , Takanashi Masakatsu , Kuroda Masahiko
Published: September 2011

MicroRNAs (miRNAs) belong to a class of endogenously expressed non‐coding small RNAs that function primarily as gene regulators. Growing evidence suggests that miRNAs play a significant role in tumor development, making them potential biomarkers for cancer diagnosis and prognosis. The miR‐17–92 cluster has emerged as an important locus, being highly overexpressed in several cancers in association with cancer development and progression. The miR‐17–92 miRNA cluster generates a single polycistronic primary transcript that yields six mature miRNAs: miR‐17, miR‐18a, miR‐19a, miR‐20a, miR‐19b, and miR‐92a. In colon cancer development, the pathophysiologic roles of these transcripts and their targets are largely unknown. In the present study, we performed copy number analyses of the six miRNAs transcribed from the miR‐17–92 cluster in colon tumor tissues. We determined that miR‐92a was transcribed at higher levels than the other five miRNAs in both adenomas and carcinoma. In addition, miR‐92a directly targeted the anti‐apoptotic molecule BCL‐2‐interacting mediator of cell death (BIM) in colon cancer tissues. An anti‐miR‐92a antagomir induced apoptosis of colon cancer‐derived cell lines. These data indicate that miR‐92a plays a pivotal role in the development of colorectal carcinoma. (Cancer Sci 2011; 102: 2264–2271)
Antitumor effects of α‐bisabolol against pancreatic cancer
Authors: Seki Takashi , Kokuryo Toshio , Yokoyama Yukihiro , Suzuki Hisanori , Itatsu Keita , Nakagawa Akifumi , Mizutani Tetsushi , Miyake Takashi , Uno Masanori , Yamauchi Kohei , Nagino Masato
Published: September 2011

In the present study, we investigated whether α‐bisabolol, a sesquiterpene alcohol present in essential oils derived from a variety of plants, has antitumor effects against pancreatic cancer. α‐Bisabolol induced a decrease in cell proliferation and viability in pancreatic cancer cell lines (KLM1, KP4, Panc1, MIA Paca2), but not in pancreatic epithelial cells (ACBRI515). α‐Bisabolol treatment induced apoptosis and suppressed Akt activation in pancreatic cancer cell lines. Furthermore, α‐bisabolol treatment induced the overexpression of early growth response‐1 (EGR1), whereas EGR1 siRNA decreased the α‐bisabolol‐induced cell death of KLM1 cells. Tumor growth in both subcutaneous and peritoneal xenograft nude mouse models was significantly inhibited by intragastric administration of 1000 mg/kg of α‐bisabolol, once a week for three weeks. The results indicate that α‐bisabolol could be a novel therapeutic option for the treatment of pancreatic cancer. (Cancer Sci 2011; 102: 2199–2205)
Low‐dose desmopressin improves hypothermia‐induced impairment of primary haemostasis in healthy volunteers*
Authors: Ng K. F. J. , Cheung C. W. , Lee Y. , Leung S. W. S.
Published: September 2011

Mild hypothermia (34–35 °C) increases peri‐operative blood loss. We have previously demonstrated the beneficial effect of in vitro desmopressin on impairment of primary haemostasis associated with hypothermia. This study evaluated subcutaneous desmopressin in 52 healthy volunteers, randomly assigned to receive either normal saline or desmopressin 1.5, 5 or 15 μg (with 13 in each group). Blood samples were collected before and 2 h after drug administration and incubated at 32 and 37 °C. Platelet function analyser PFA‐100® closure times were measured. Hypothermia at 32 °C prolonged mean (95% CI) closure times (for adenosine diphosphate/collagen by 11.3% (7.5–15.2%) and for adrenaline/collagen by 16.2% (11.3–21.2%); these changes were reversed by desmopressin. A very small dose was found to be effective (1.5 μg); this dose did not significantly change closure times at 37 °C, but fully prevented its prolongation at 32 °C. Subcutaneous desmopressin prevents the development of hypothermia‐induced impairment of primary haemostasis.

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A functional genomic approach to the study of the milking ability in dairy sheep
Authors: Dhorne‐Pollet S. , Robert‐Granié C. , Aurel M. R. , Marie‐Etancelin C.
Published: September 2011

To understand the mechanisms underlying milk ability and more precisely the kinetics of milk emission, we compared teat transcriptome profiles from Lacaune ewes in the tails of the milk flow phenotypic distribution. Two different arrays containing respectively 1896 and 13 168 PCR products selected from several tissue‐specific cDNA libraries, including mammary gland, allowed the identification of 73 differentially expressed genes between teats from high and low milk flow ewes. Genes involved in muscle contraction were identified as over‐expressed, and genes encoding collagen were found to be under‐expressed in teats from low milk flow ewes. We confirmed this underexpression of COL1A1 and COL1A2 in low‐milk flow ewes using RT‐qPCR. These results suggest that milking ability may be due to the capacity of the teat sphincter to relax during mechanical milking. We propose that an optimal condition for mechanical milking may require proper relaxation of the teats. To our knowledge, this is the first transcriptomic analysis studying milking ability, using udder tissue for gene expression profiling, which demonstrates that mechanical milking ability is not only determined by morphological features but also by tissue composition.
Pre‐hypertension: how low to go and do drugs have a role?
Authors: McInnes Gordon
Published: September 2011

People with pre‐hypertension (high blood pressure but below the conventional threshold for intervention with antihypertensive drugs) undoubtedly have increased risk of cardiovascular and other complications. However, the vast majority has low absolute risk and whether treatment would be beneficial is uncertain. While pharmacotherapy has attractions from a public health perspective, clinicians and crucially those with pre‐hypertension require robust evidence that drug treatment will lead to short term as well as long term gains. Any changes in recommendations should await adequately powered outcome studies which provide solid evidence of the magnitude of absolute risk reduction in treating pre‐hypertension and assessment of the cost‐effectiveness.
Impact of genetic factors (VKORC1, CYP2C9, CYP4F2 and EPHX1) on the anticoagulation response to fluindione
Authors: Lacut Karine , Ayme‐Dietrich Estelle , Gourhant Lenaick , Poulhazan Elise , Andro Marion , Becquemont Laurent , Mottier Dominique , Le Gal Gregoire , Verstuyft Celine
Published: September 2011

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• CYP2C9 and VKORC1 genetic variants contribute to differences in patients' responses to anticoagulant coumarin derivatives. Patients carrying the VKORC1 1173TT genotype have a decreased time to the first INR within the therapeutic range and to the first INR >4, and also require lower warfarin maintenance doses. Patients carrying the *2 or *3 CYP2C9 allele have lower maintenance warfarin requirements than those carrying the wild‐type allele. The role of CYP2C9 and VKORC1 genetic variants in fluindione response is unknown.

WHAT THIS STUDY ADDS

• Our results showed that VKORC1 genotype had a significant impact on early anticoagulation (INR value ≥2 after the first two intakes) (P < 0.0001), on the time required to reach a first INR within the therapeutic range (P < 0.0001), on the time to obtain a first INR value >4 (P= 0.0002) and on the average daily dose of fluindione during the first period of stability (19.8 mg (±5.5) for VKORC1 CC, 14.7 mg (±6.2) for VKORC1 CT and 8.2 mg (±2.5) for VKORC1 TT, P < 0.0001). CYP2C9, CYP4F2 and EPHX1 genotypes did not significantly influence the response to fluindione. This report provides new information on the respective role of common genetic polymorphisms on anticoagulation induced by another class of anticoagulant drugs rather than coumarin derivatives.

AIM Genetic variants of the enzyme that metabolizes warfarin, cytochrome P‐450 2C9 (CYP2C9) and of a key pharmacologic target of vitamin K antagonists, vitamin K epoxide reductase (VKORC1), contribute to differences in patients' responses to coumarin derivatives. The role of these variants in fluindione response is unknown. Our aim was to assess whether genetic factors contribute to the variability in the response to fluindione.

METHODS Four hundred sixty‐five patients with a venous thromboembolic event treated by fluindione for at least 3 months with a target international normalized ratio (INR) of 2.0 to 3.0 were studied. VKORC1, CYP2C9, CYP4F2 and EPHX1 genotypes were assessed. INR checks, fluindione doses and bleeding events were collected.

RESULTS VKORC1 genotype had a significant impact on early anticoagulation (INR value ≥2 after the first two intakes) (P < 0.0001), on the time required to reach a first INR within the therapeutic range (P < 0.0001) and on the time to obtain a first INR value > 4 (P= 0.0002). The average daily dose of fluindione during the first period of stability was significantly associated with the VKORC1 genotype: 19.8 mg (±5.5) for VKORC1 CC, 14.7 mg (±6.2) for VKORC1 CT and 8.2 mg (±2.5) for VKORC1 TT (P < 0.0001). CYP2C9, CYP4F2 and EPHX1 genotypes did not significantly influence the response to fluindione.

CONCLUSIONS VKORC1 genotype strongly affected anticoagulation induced by fluindione whereas CYP2C9, CYP4F2 and EPHX1 genotypes seemed less determining.
An increase in serum tryptase even below 11.4 ng/mL may indicate a mast cell‐mediated hypersensitivity reaction: a prospective study in Hymenoptera venom allergic patients
Authors: Borer‐Reinhold M. , Haeberli G. , Bitzenhofer M. , Jandus P. , Hausmann O. , Fricker M. , Helbling A. , Müller U.
Published: September 2011

Background

During a systemic hypersensitivity reaction (SR), an increase in serum tryptase compared to the baseline value is an indicator of mast cell activation, most often due to an IgE‐mediated mechanism.

Objective

To study the relevance of an increase in serum tryptase below the upper normal value of 11.4 ng/mL.

Methods

Serum tryptase levels were measured in 35 patients with Hymenoptera venom hypersensitivity before and during venom exposure. Of these, 20 developed SR to stings or following venom injections during immunotherapy (reactors), while 15 tolerated reexposure to stings or venom injections during immunotherapy without SR (non‐reactors). Serum tryptase was estimated at 2, 5 and 24 h after exposure and was compared to a baseline value obtained before or at least 72 h after exposure.

Results

Considering circadian variation of serum tryptase, a relative increase to ≥135% of the baseline value (relative delta bound) was defined to indicate mast cell activation. Such an increase was observed in 17 of 20 reactors (85%), but none of 15 non‐reactors. A serum tryptase of ≥11.4 ng/mL following venom exposure was observed in eight of the 20 reactors (40%) and 2 (13.3%) of the 15 non‐reactors. Both these non‐reactors also had an elevated baseline serum tryptase.

Conclusions and Clinical Relevance

Serum tryptase values obtained during a suspected hypersensitivity reaction must always be compared to a baseline value. A relative tryptase increase to ≥135% of the baseline value during a suspected hypersensitivity reaction indicates mast cell activation even below 11.4 ng/mL.
Impaired gallbladder motility and the effect of metformin therapy in patients with polycystic ovary syndrome
Authors: Isik Serhat , Ozcan Hatice N. , Ozuguz Ufuk , Berker Dilek , Tutuncu Yasemin , Akbaba Gulhan , Guler Serdar
Published: September 2011

Objective  Impaired gallbladder (GB) emptying is a well‐documented contributor to gallstone formation. The aim of this study was to evaluate GB motility in patients with polycystic ovary syndrome (PCOS).

Methods  The study population consisted of 36 PCOS patients and 20 healthy controls. GB volume was calculated using the ellipsoid formula (π/6 × L × D × W) after three‐dimensional measurements were made by ultrasound [length (L), width (W) and depth (D)]. Following the determination of fasting GB volume (V0), patients were given a standard liquid meal. GB volume measurement was then repeated after 10, 20, 30, 40, 50, 60, 75 and 90 min. Gallbladder ejection fraction (GBEF) was calculated after each measurement. PCOS patients were re‐evaluated after a 12‐week course of metformin therapy at a dose of 1000 mg/day.

Results  Mean baseline GB volume (V0) was significantly higher in the patient group compared to the control group (27·2 ± 12·5 cm3vs 13·3 ± 7·0 cm3, P < 0·001). While baseline GBEF values were similar between groups, increases in GBEF were significantly lower in the PCOS group starting from 20 min after consumption of a standard test meal. A 12‐week course of metformin therapy resulted in significant improvements in GB volume and GBEF values with a reversal of metabolic and hormonal abnormalities.

Conclusion  For the first time in the literature, we managed to demonstrate impaired GB motility in patients with PCOS. Metformin therapy not only improves the metabolic and hormonal imbalances associated with PCOS but also has a positive influence on GB motility.
Environmental context alters ecological trade‐offs controlling ant coexistence in a spatially heterogeneous region
Authors: WIESCHER PHILIPP T. , PEARCE‐DUVET JESSICA M. C. , FEENER DONALD H.
Published: September 2011

1. Ecological trade‐offs in ant (Hymenoptera: Formicidae) assemblages and their implications for coexistence boast a rich history in entomology. Yet investigations of trade‐offs have largely been limited to homogeneous environments. We examined how environmental context modifies trade‐off expression in an ant assemblage spanning a heterogeneous region in central Florida, U.S.A.

2. We examined how trade‐off expression is altered among two contrasting habitat types: open shrub and forest. We tested for the presence of the dominance‐discovery trade‐off and two dominance‐thermal tolerance trade‐offs by estimating behavioral dominance, discovery ability, and thermal tolerance (foraging thermal limit, lethal temperature, and maximal abundance temperature) for a wide range of interacting ant species.

3. We found significantly linear dominance hierarchies in both shrub and forest habitats, showing dominant species out‐compete subordinates for food resources. In thermally stressful shrub habitats, subordinates exhibit higher thermal tolerances, take greater thermal risks, and reach maximum forager abundances at higher temperatures than do dominant species. This suggests temperature mediated trade‐offs control coexistence in shrub habitat. In thermally moderate forest habitat, we found limited evidence for trade‐offs between competitive dominance and resource discovery or between dominance and thermal traits, implying other processes control coexistence. These results demonstrate that trade‐offs controlling ant coexistence may be contingent on environmental context.
Precision of age estimates derived from scales and pectoral fin rays of blue sucker
Authors: LABAY S. R. , KRAL J. G. , STUKEL S. M.
Published: September 2011

Abstract  Evaluating the response of fish populations to environmental influences requires precise age estimation. Pectoral fin rays and scales were compared to determine which is more precise for estimating age of blue sucker, Cycleptus elongatus (Lesueur), from the Missouri River, USA. Mean coefficient of variation was significantly lower for fin rays both among three novice readers (rays 19.9%; scales 23.1%) and among three reads by a single experienced reader (rays 11.8%; scales 18.6%). Additionally, exact per cent agreement (rays 20.0%; scales 14.3%) and within‐1‐year per cent agreement (rays 89.1%; scales 73.9%) were higher for fin rays compared with scales for multiple reads by the same experienced reader. Age–bias plots revealed that scale ages were lower than fin‐ray ages >7. The use of fin rays is recommended for estimating ages of blue sucker until validation procedures are conducted.
Handling dip discrimination phenomenon in common‐reflection‐surface stack via combination of output‐imaging‐scheme and migration/demigration
Authors: Yang Kai , Chen Bao‐shu , Wang Xiao‐jiang , Yang Xiao‐chun , Liu Jun‐rong
Published: September 2011

In the application of a conventional common‐reflection‐surface (CRS) stack, it is well‐known that only one optimum stacking operator is determined for each zero‐offset sample to be simulated. As a result, the conflicting dip situations are not taken into account and only the most prominent event contributes to any a particular stack sample. In this paper, we name this phenomenon caused by conflicting dip problems as ‘dip discrimination phenomenon’. This phenomenon is not welcome because it not only leads to the loss of weak reflections and tips of diffractions in the final zero‐offset‐CRS stacked section but also to a deteriorated quality in subsequent migration.

The common‐reflection‐surface stack with the output imaging scheme (CRS‐OIS) is a novel technique to implement a CRS stack based on a unified Kirchhoff imaging approach. As far as dealing with conflicting dip problems is concerned, the CRS‐OIS is a better option than a conventional CRS stack. However, we think the CRS‐OIS can do more in this aspect. In this paper, we propose a workflow to handle the dip discrimination phenomenon based on a cascaded implementation of prestack time migration, CRS‐OIS and prestack time demigration. Firstly, a common offset prestack time migration is implemented. Then, a CRS‐OIS is applied to the time‐migrated common offset gather. Afterwards, a prestack time demigration is performed to reconstruct each unmigrated common offset gather with its reflections being greatly enhanced and diffractions being well preserved.

Compared with existing techniques dealing with conflicting dip problems, the technique presented in this paper preserves most of the diffractions and accounts for reflections from all possible dips properly. More importantly, both the post‐stacked data set and prestacked data set can be of much better quality after the implementation of the presented scheme. It serves as a promising alternative to other techniques except that it cannot provide the typical CRS wavefield attributes. The numerical tests on a synthetic Marmousi data set and a real 2D marine data set demonstrated its effectiveness and robustness.
Break through the limits of vibroseis data quality
Authors: Wei Zhouhong , Phillips Thomas F.
Published: September 2011

The vibroseis method has become the principal data acquisition method in land seismic exploration. It seems that this method has been extended to its limits as the search for energy resources continues. Many practical issues arising from field operations have remained theoretically unexplained, for example, variations in wavelet arrival time, inaccurate wavelet estimation and harmonics in the wavelet itself. The focus of this paper is the proposal of a new model, which is referred to as the vibrator‐coupled ground model, to simulate the filtering effects of a complex coupling system consisting of the coupling between the baseplate and the ground as well as the coupling between the captured ground mass near the vibrator baseplate and the surrounding earth. With this vibrator‐coupled ground model many of the practical issues mentioned above were reasonably addressed. Furthermore, it was demonstrated from experimental tests that both the pilot sweep and the weighted‐sum groundforce, when filtered by the vibrator‐coupled ground model, are proportional to the far‐field particle velocity whereas the unfiltered signals are not. The harmonics on the filtered weighted‐sum groundforce successfully maintain a proportional relationship with the harmonics seen in the far‐field signal.
Joint inversion of rock properties from sonic, resistivity and density well‐log measurements
Authors: Dell’Aversana Paolo , Bernasconi Giancarlo , Miotti Fabio , Rovetta Diego
Published: September 2011

Well‐log data are processed in order to derive subsurface physical parameters, namely rock porosity, fluid saturations and permeability. This step involves the selection and inversion of experimental constitutive equations, which are the link between the rock parameters and geophysical measurements. In this paper we investigate the rock parameter observability and the reliability of well‐log data processing. We present a visual analysis of the constitutive equations and of the inverse problem conditioning, when using independently, or jointly, log data from different domains. The existence of a common set of rock properties (cross‐properties) that influence different measurements, makes it possible to reduce the ambiguities of the interpretation. We select a test case in a reservoir scenario and we explore how to determine rock porosity and fluid saturation from sonic, conductivity and density logs. We propose a Bayesian joint inversion procedure, which is able to control the conditioning problems, to efficiently take into account input data and model uncertainty and to provide a confidence interval for the solution. The inversion procedure is validated on a real well‐log data set.
Reconstruction of geologic bodies in depth associated with a sedimentary basin using gravity and magnetic data
Authors: Barbosa Valéria C. F. , Silva João B. C.
Published: September 2011

We present a comprehensive review of the most common gravity and magnetic interpretation methods to in depth retrieval of the geometry of geologic bodies associated with a sedimentary basin. We identify three types of bodies: 1) the sedimentary basement relief, 2) salt bodies and 3) mafic intrusions in a sedimentary section. In reconstructing basement topography through gravity and/or magnetic data we identify three groups of methods: the automatic, the spectral and the nonspectral methods. The reconstruction of salt bodies from gravity data usually uses interactive forward modelling but recently gravity inversion methods have been developed to interpret this kind of geologic environment. Finally, the problem of reconstructing intrusive bodies using magnetic and/or gravity data employs three strategies to interpret mafic or ultramafic intrusions in a sedimentary section: the automatic methods, interactive forward modelling and the inversion methods.
Hybrid modelling of gravity, gravity gradients and magnetic fields
Authors: Schmidt S. , Plonka C. , Götze H.‐J. , Lahmeyer B.
Published: September 2011

Modern geophysical interpretation requires an interdisciplinary approach and software capable of handling multiple geophysical data types such as seismic, full tensor gravity gradiometry, magnetics and magnetotellurics. We use the IGMAS+ (Interactive Gravity and Magnetic Application System) geo‐modelling software that is designed for 3D gravity, gravity gradient and magnetic modelling. This paper deals with a special aspect of potential field modelling, combining conventional triangulated model geometries (building polyhedrons) with voxel cubes.

The hybrid modelling combines the advantages of both the vector and raster modelling system: both may be used alone (polyhedrons without voxels, voxels without polyhedrons) or simultaneously by superposition of both effects, which provides flexibility towards full interoperability. The key idea of our approach is, on the one hand to use two different, completely independent geometries (vector and raster) and give on the other hand the possibility to link both on demand for either editing the voxel model or to combine a large number of voxel cells under a common physical parameter function – which results in more reliable parameter inversion results.
Traveltime parameters in a tilted elliptical anisotropic medium‡
Authors: Golikov Pavel , Stovas Alexey
Published: September 2011

In this paper, we derive analytical expressions for one‐way and two‐way kinematical parameters in elliptical tilted transverse isotropy media. We show that the homogeneous elliptical tilted transverse isotropy models result in hyperbolic moveout with a reflection point sideslip x0, which can be considered as an additional traveltime parameter for one‐way wave propagation. For homogeneous elliptical tilted transverse isotropy models we show that the inversion of one‐way traveltime parameters suffers from the ambiguity for large tilts. It is shown that the accuracy of the inversion is sensitive to the error in x0. We also derive and invert the traveltime parameters for a vertically heterogeneous elliptical tilted transverse isotropy model with a tilt gradually changing with depth. The a priori knowledge of parameter δ is very important for inversion. The wrong choise of this parameter results in significant errors in inverted model parameters.
Fire‐induced tree mortality in a neotropical forest: the roles of bark traits, tree size, wood density and fire behavior
Authors: Brando Paulo M. , Nepstad Daniel C. , Balch Jennifer K. , Bolker Benjamin , Christman Mary C. , Coe Michael , Putz Francis E.
Published: September 2011

Large‐scale wildfires are expected to accelerate forest dieback in Amazônia, but the fire vulnerability of tree species remains uncertain, in part due to the lack of studies relating fire‐induced mortality to both fire behavior and plant traits. To address this gap, we established two sets of experiments in southern Amazonia. First, we tested which bark traits best predict heat transfer rates (R) through bark during experimental bole heating. Second, using data from a large‐scale fire experiment, we tested the effects of tree wood density (WD), size, and estimated R (inverse of cambium insulation) on tree mortality after one to five fires. In the first experiment, bark thickness explained 82% of the variance in R, while the presence of water in the bark reduced the difference in temperature between the heat source and the vascular cambium, perhaps because of high latent heat of vaporization. This novel finding provides an important insight for improving mechanistic models of fire‐induced cambium damage from tropical to temperate regions. In the second experiment, tree mortality increased with increasing fire intensity (i.e. as indicated by bark char height on tree boles), which was higher along the forest edge, during the 2007 drought, and when the fire return interval was 3 years instead of one. Contrary to other tropical studies, the relationship between mortality and fire intensity was strongest in the year following the fires, but continued for 3 years afterwards. Tree mortality was low (≤20%) for thick‐barked individuals (≥18 mm) subjected to medium‐intensity fires, and significantly decreased as a function of increasing tree diameter, height and wood density. Hence, fire‐induced tree mortality was influenced not only by cambium insulation but also by other traits that reduce the indirect effects of fire. These results can be used to improve assessments of fire vulnerability of tropical forests.
Bacterial killing by several root filling materials and methods in an ex vivo infected root canal model
Authors: Özcan E. , Eldeniz A. U. , Arı H.
Published: September 2011

Özcan E, Eldeniz AU, Arı H. Bacterial killing by several root filling materials and methods in an ex vivo infected root canal model. International Endodontic Journal, 44, 1102–1109, 2011.

Aim  To evaluate the ability of two root canal sealers (Epoxy resin‐based AH Plus® or polydimethylsiloxane‐based GuttaFlow®) and five root filling techniques (continuous wave of condensation, Thermafil®, lateral condensation, matched taper single gutta‐percha point, laterally condensed‐matched taper gutta‐percha point) to kill bacteria in experimentally infected dentinal tubules.

Methodology  An infected dentine block model was used. One hundred and twenty extracted, single‐rooted human teeth were randomly divided into 10 test (n = 10) and 2 control (n = 10) groups. The roots, except negative controls, were infected with Enterococcus faecalis for 21 days. The root canals were then filled using the test materials and methods. Positive controls were not filled. Sterile roots were used as negative controls. Dentine powder was obtained from all root canals using gates glidden drills using a standard method. The dentine powder was diluted and inoculated into bacterial growth media. Total colony‐forming units (CFU) were calculated for each sample. Statistical analysis was performed using the Kruskal–Wallis and Mann–Whitney U test.

Results  The epoxy resin‐based sealer was effective in killing E. faecalis except when using Thermafil (P < 0.05), but the polydimethylsiloxane‐based sealer was not effective in killing this microorganism except in the continuous wave group (P < 0.05).

Conclusions  In the test model, AH Plus killed bacteria in infected dentine more effectively than GuttaFlow. The filling method was less important than the sealer material.
A triadic interplay between academics, practitioners and students in the nursing theory and practice dialectic
Authors: Chan Engle Angela , Chan Kitty , Liu Yat Wa Justina
Published: September 2011

chan e.a., chan k. & liu y.w.j. (2011) A triadic interplay between academics, practitioners and students in the nursing theory and practice dialectic. Journal of Advanced Nursing 68(5), 1038–1049.

Aim.  This article is a report of a descriptive study of the effectiveness of classroom teaching by clinical nurse specialists on students’ transfer of theory into practice.

Background.  Ongoing concern about a theory‐practice merger in nursing has led to collaborative initiatives between academics and practitioners globally. There are different forms of collaborative efforts, but information on their evaluation is scarce and inconclusive. Integration of theory and practice is important for an outcome‐based approach, which emphasizes students’ clinical competence as the measure of success. The limited nursing discussion on theory and practice collaboration in education was our impetus for the study.

Methods.  Between 2007 and 2008, focus group interviews were held, first with 75 and then with 35 from the same group of first‐year students, regarding their learning experience from the lectures of the two clinical nurse specialists in diabetes and colostomy care, respectively, prior to and after their clinical placements. Six of their clinical instructors and the two clinical nurse specialists were also interviewed. The audiotaped interviews were transcribed verbatim and analysed using content analysis.

Findings.  Three themes were identified: impact of students’ vicarious learning from clinical nurse specialists’ stories of experience; improving the collaboration between clinical nurse specialists and subject lecturers for junior students’ learning experience; continuity in the clinical integration of theory‐practice as dialectic through an interplay between academics, practitioners and students.

Conclusion.  The theory and practice issue is best addressed as a triadic paradigm in a community of practice with the collaboration among academics, practitioners and students.
A comparison of patient and family caregiver prospective control over lung cancer
Authors: Lobchuk Michelle M. , McPherson Christine J. , McClement Susan E. , Cheang Mary
Published: September 2011

lobchuk m.m., mcpherson c.j., mcclement s.e. & cheang m. (2011) A comparison of patient and family caregiver prospective control over lung cancer. Journal of Advanced Nursing 68(5), 1122–1133.

Aim.  This paper is a report of our secondary analysis of patient and family caregiver prospective control in lung cancer.

Background.  Control beliefs underlie self‐care in sickness and health. Self‐care often involves ‘shared’ activities between the afflicted individual and caregiving family and friends. However, depending on how control is perceived, conflicts can occur in decision‐making thus jeopardizing optimal self‐care. We need to comprehend how control beliefs compare between patients and caregivers and how their control beliefs are linked with dealing with serious illness.

Methods.  Based on questionnaire data collected in our larger study between September 2005 and February 2009, we conducted exploratory comparative analyses of 304 patients’ and caregivers’ control beliefs in managing lung cancer. Eight 5‐point response items captured prospective control. Exploratory factor analysis with promax rotation was conducted to compare dyadic perceptions on the dimensionality of prospective control. We also conducted exploratory correlations between control beliefs and smoking cessation, attributional reactions, caregiver helping and symptom reports.

Results.  Principal component analysis identified the same factors for patients and caregivers: factor 1, Fate control and factor 2, Team control. Patient and caregiver ‘Fate’ and ‘Team’ control sub‐scales were respectively associated with hope, caregiver helping and patient smoking cessation.

Conclusion.  Clinicians need to support, adapt or develop a philosophy of cancer care that is inclusive of partnerships, drawing on beliefs of patients and caregivers that controlling lung cancer is a team effort which in turn is tentatively linked to patient smoking cessation, positive emotions and caregiver helping.
Bayesian inference on age‐specific survival for censored and truncated data
Authors: Colchero Fernando , Clark James S.
Published: September 2011

1. Traditional estimation of age‐specific survival and mortality rates in vertebrates is limited to individuals with known age. Although this subject has been studied extensively using effective capture–recapture and capture–recovery models, inference remains challenging because of large numbers of incomplete records (i.e. unknown age of many individuals) and because of the inadequate duration of the studies.

2. Here, we present a hierarchical model for capture–recapture/recovery (CRR) data sets with large proportions of unknown times of birth and death. The model uses a Bayesian framework to draw inference on population‐level age‐specific demographic rates using parametric survival functions and applies this information to reconstruct times of birth and death for individuals with unknown age.

3. We simulated a set of CRR data sets with varying study span and proportions of individuals with known age, and varying recapture and recovery probabilities. We used these data sets to compare our method to a traditional CRR model, which requires knowledge of individual ages. Subsequently, we applied our method to a subset of a long‐term CRR data set on Soay sheep.

4. Our results show that this method performs better than the common CRR model when sample sizes are low. Still, our model is sensitive to the choice of priors with low recapture probability and short studies. In such cases, priors that overestimate survival perform better than those that underestimate it. Also, the model was able to estimate accurately ages at death for Soay sheep, with an average error of 0·94 years and to identify differences in mortality rate between sexes.

5. Although many of the problems in the estimation of age‐specific survival can be reduced through more efficient sampling schemes, most ecological data sets are still sparse and with a large proportion of missing records. Thus, improved sampling needs still to be combined with statistical models capable of overcoming the unavoidable limitations of any fieldwork. We show that our approach provides reliable estimates of parameters and unknown times of birth and death even with the most incomplete data sets while being flexible enough to accommodate multiple recapture probabilities and covariates.
Phylogeography at large spatial scales: incongruent patterns of population structure and demography of Pan‐American butterflies associated with weedy habitats
Authors: Runquist Erik B. , Forister Matthew L. , Shapiro Arthur M.
Published: September 2011

Aim  Few studies of comparative phylogeography have been conducted at very large spatial scales, encompassing species that are distributed across multiple continents. Several Pan‐American butterfly species associated with weedy, human‐modified habitats were studied using comparative phylogeographic tools to test for the congruence of demographic histories across a range of spatial scales and to investigate the effects of human‐facilitated range expansion.

Location  North and South America, mainly the southern United States, Brazil and Argentina.

Methods  The mitochondrial DNA cytochrome c oxidase subunit II region (COII) was sequenced for Hylephila phyleus, Lerodea eufala, Erynnis funeralis and Agraulis vanillae across their North and South American ranges. Data from these conspecifics were compared with variation in COII sequences between allopatric congener pairs on both continents whose ranges approximate the conspecifics and also share similar weedy habitat associations: Ancyloxypha numitor versus Ancyloxypha nitedula, Vanessa annabella versus Vanessa carye, and Euptoieta claudia versus Euptoieta hortensia. We tested for similarities in demographic histories within and across continents for each species using pairwise distances, population genetic statistics, mismatch distributions and deviations from mutation‐drift equilibrium.

Results  Mean pairwise divergence across continents was lower for Lerodea eufala and Hylephila phyleus (with several shared Pan‐American haplotypes each) compared with Erynnis funeralis and Agraulis vanillae (both with no shared haplotypes). Differentiation between congeneric species pairs was generally significantly higher than conspecific divergence across continents, but North and South American populations of A. vanillae were more divergent than V. annabella and V. carye. We found deviations from mutation‐drift equilibrium in A. vanillae. Population‐level variation was greater than the variation across continents for H. phyleus and L. eufala.

Main conclusions  We find little congruence in phylogeographic patterns among these taxa across continents, although similar demographic patterns can be detected at smaller regional levels. Except for Californian populations of some species, the North American distributions of these weedy butterfly species appear to largely pre‐date the influences of human‐facilitated range expansion.
Life is back to normal and yet not – partners’ and patient’s experiences of life of the first year after colorectal cancer surgery
Authors: Ohlsson‐Nevo Emma , Andershed Birgitta , Nilsson Ulrica , Anderzén‐Carlsson Agneta
Published: September 2011

Aim.  To describe the experience of life the first year after surgery from the perspective of persons treated for colorectal cancer and their partners.

Background.  Colorectal cancer is a common cancer form, and treatment can cause unpleasant side effects such as sexual dysfunction and bowel problems. Partners struggle to keep family life normal and provide support. Little is known about couples’ experiences a year after treatment for colorectal cancer.

Design.  Qualitative descriptive.

Methods.  Individual semi‐structured interviews with 13 persons treated for colorectal cancer and their partners, a total of 26 participants.

Results.  One theme was identified in the study; ‘Life is back to normal and yet not’: participants described living a normal but different life than before. Three subthemes were identified; ‘Life has a shadow of death’, ‘The treated body sets the rules’ and ‘To share or not share the illness’.

Conclusions.  Findings showed that both the patients’ and their partners’ lives were influenced by uncertainty and the condition of the patient. Attitudes varied towards sharing the illness. It was found that information needs varied both within and between couples. A future challenge to healthcare personnel is the obligation to meet the needs of both patients and their partners on the illness trajectory and recovery after treatment for colorectal cancer.

Relevance to clinical practice.  Findings enhance the understanding of the impact of colorectal cancer on both patients and partners. Healthcare personnel need to assess both the patient’s and partner’s need for information, support and assistance. Support groups could be an effective tool for providing information, communication and support. Future studies are needed to evaluate such groups.