bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial variation in selection on corolla shape in a generalist plant is promoted by the preference patterns of its local pollinators
Authors: Gómez José M , Bosch Jordi , Perfectti Francisco , Fernández J.D , Abdelaziz Mohamed , Camacho J.P.M
Published: June 2008

An adaptive role of corolla shape has been often asserted without an empirical demonstration of how natural selection acts on this trait. In generalist plants, in which flowers are visited by diverse pollinator fauna that commonly vary spatially, detecting pollinator-mediated selection on corolla shape is even more difficult. In this study, we explore the mechanisms promoting selection on corolla shape in the generalist cruciferErysimum mediohispanicumPolatschek (Brassicaceae). We found that the main pollinators ofE. mediohispanicum(large bees, small bees and bee flies) discriminate between different corolla shapes when offered artificial flowers without reward. Importantly, different pollinators prefer different shapes: bees prefer flowers with narrow petals, whereas bee flies prefer flowers with rounded overlapping petals. We also found that flowers with narrow petals (those preferred by bees) produce both more pollen and nectar than those with rounded petals. Finally, different plant populations were visited by different faunas. As a result, we found spatial variation in the selection acting on corolla shape. Selection favoured flowers with narrow petals in the populations where large or small bees are the most abundant pollinator groups. Our study suggests that pollinators, by preferring flowers with high reward, exert strong selection on theE. mediohispanicumcorolla shape. The geographical variation in the pollinator-mediated selection onE. mediohispanicumcorolla shape suggests that phenotypic evolution and diversification can occur in this complex floral trait even without specialization.
Phylogenetic distributions of British birds of conservation concern
Authors: Thomas Gavin H
Published: June 2008

Recent studies suggest that species' life histories and ecology can be used to forecast future extinction risk. Threatened species often share similar traits such that if a trait predisposing a species to decline or extinction is evolutionarily conserved, then close relatives of threatened species are themselves likely to be at risk. The phylogenetic distribution of current threat has been argued to provide insight into the species that could be threatened in the future when trait data are not available. Conservation criteria are typically based on multiple indices that capture different symptoms of threat including population trends and range contraction. However, there is no reason to assume consistent phylogenetic distributions of different symptoms. I construct a molecular phylogeny of 249 species of British birds (more than 93% of the breeding and wintering species) and use this to show that the species that are threatened due to population declines are phylogenetically more closely related than expected by chance alone. However, species that are listed for other reasons, including range contraction, are distributed randomly with respect to phylogeny. I suggest that while phylogeny can be informative with respect to identifying clades that are susceptible to some measures of extinction risk, such patterns are likely to be idiosyncratic with respect to symptom and taxa.
‘Kids who Smoke Think that They Can Be Adults as Well’: Children's Smoking and Transitions to Adulthood
Authors: Milton Beth S. , Dugdill Lindsey , Porcellato Lorna A. , Springett R. Jane
Published: June 2008

This article aims to explore the ways in which preadolescents associate smoking with transitions to adulthood, in the context of sociological theories of childhood, using data from the Liverpool Longitudinal Study of Smoking. The research found that at age 9 many of the cohort argued that smoking was more acceptable for adults because they had bigger bodies than children. Some children also suggested that smoking was appropriate for adults because adults were competent to make important decisions and to balance risks. By age 11, when several of the cohort had actually tried smoking, children's views about the risks smoking posed to their bodies had altered, and many children were aware of smoking‐related disease among adults. The cohort also suggested that some children might take up smoking to demonstrate that they are ‘grown up’ too. In the UK, legal restrictions on the age of tobacco purchase are reinforced by social norms that construct smoking as an activity that is only suitable for adults. The goal of legal restrictions that ban the sale of cigarettes to children is to protect their health. The unintended outcome, however, is that for many young people smoking is a way of demonstrating maturity and adult status.
Children as ‘Being and Becomings’: Children, Childhood and Temporality
Authors: Uprichard Emma
Published: June 2008

Notions of ‘being’ and ‘becoming’ are intrinsic to childhood research. Whilst the ‘being’ child is seen as a social actor actively constructing ‘childhood’, the ‘becoming’ child is seen as an ‘adult in the making’, lacking competencies of the ‘adult’ that he or she will ‘become’. However, I argue that both approaches are in themselves problematic. Instead, theorising children as ‘being and becomings’ not only addresses the temporality of childhood that children themselves voice, but presents a conceptually realistic construction suitable to both childhood researchers and practitioners.
Local injection of botulinum toxin A for palmar hyperhidrosis: Usefulness and efficacy in relation to severity
Authors: YAMASHITA Noriko , SHIMIZU Hirokazu , KAWADA Morihiro , YANAGISHITA Takeshi , WATANABE Daisuke , TAMADA Yasuhiko , MATSUMOTO Yoshinari
Published: June 2008

Botulinum toxin A is widely used in Europe and the USA for the treatment of localized hyperhidrosis, and its efficacy has been recognized. In this study, botulinum toxin A (Botox) was locally injected at 30 sites (2 U/injection) on the right palm in 27 patients with palmar hyperhidrosis (14 severe patients, 13 mild patients), and the results confirmed the efficacy of injection. The amount of sweat was then quantified for the left and right hands every month after local injection. The quantity of sweat on the treated hand was approximately one‐fifth that on the untreated hand. In addition, the quantity of sweat on the untreated hand decreased slightly. Over time, the quantity of sweat on the treated hand increased slightly, but the quantity of sweat on the treated hand at 6 months after injection was less than half that before injection, and there were significant differences before and after injection. In the present study, severe sweating was defined as 1 mg/cm2/min or more and mild sweating as less than 1 mg/cm2/min, and the therapeutic effects of botulinum toxin A were analyzed in relation to severity. When compared to the mild cases, the quantity of sweat remained higher in the severe cases after botulinum toxin A therapy. Therefore, to achieve satisfactory effects in severe cases, it would be necessary to increase the number of injection sites, as well as injection dose.
p120 catenin is associated with desmogleins when desmosomes are assembled in high‐Ca2+ medium but not when disassembled in low‐Ca2+ medium in DJM‐1 cells
Authors: KANNO Miho , AOYAMA Yumi , ISA Yasuka , YAMAMOTO Yukari , KITAJIMA Yasuo
Published: June 2008

We recently showed that p120 catenin (p120ctn), which is an armadillo family protein member that binds to E‐cadherin (E‐cad), is also localized to desmosomes by directly or indirectly binding to desmogleins (Dsg). We examined whether p120ctn is associated with Dsg1 and Dsg3, as compared with E‐cad and plakoglobin (PG), in keratinocytes grown in high or low Ca2+, using a human squamous cell carcinoma cell line, DJM‐1 cells. The cell lysate of DJM‐1 cells grown in high‐ or low‐Ca2+ media was immunoprecipitated with anti‐Dsg1/2 and Dsg3 antibodies, and we examined whether p120ctn is associated with Dsg1 and Dsg3. Then, we observed the co‐localization between Dsg3 and p120ctn in cells grown in high‐ or low‐Ca2+ medium on double‐staining immunofluorescence microscopy using anti‐p120ctn and anti‐Dsg3 antibodies. Immunoprecipitates with anti‐Dsg1/2 and Dsg3 antibodies in cells grown in high‐Ca2+ medium contained p120ctn. In contrast, in low‐Ca2+ medium, p120ctn was co‐immunoprecipitated with neither Dsg1 nor Dsg3, but was co‐immunoprecipitated with E‐cad in cells grown in both high‐ and low‐Ca2+ media. Dsg3 was associated with PG in cells grown in both low‐ and high‐Ca2+ media. On immunofluorescence microscopy, p120ctn and Dsg3 were independently observed in cells grown in low‐Ca2+ medium; p120ctn, but not Dsg3, was observed in a linear pattern at the cell–cell boundary. However, they were co‐localized at cell–cell contacts in cells grown in high‐Ca2+ medium. Thus, these proteins are not co‐localized in low Ca2+ medium. These results suggest that p120ctn plays an important role in Ca2+‐induced desmosome formation.
Alcohol consumption patterns and risk factors among childhood cancer survivors compared to siblings and general population peers
Authors: Lown E. Anne , Goldsby Robert , Mertens Ann C. , Greenfield Thomas , Bond Jason , Whitton John , Korcha Rachael , Robison Leslie L. , Zeltzer Lonnie K.
Published: June 2008

Aims  This study describes alcohol consumption among adult survivors of pediatric cancer compared to sibling controls and a national sample of healthy peers. Risk factors for heavy drinking among survivors are described.

Design, setting and participants  Cross‐sectional data were utilized from the Childhood Cancer Survivor Study including adult survivors of pediatric cancer (n = 10 398) and a sibling cohort (n = 3034). Comparison data were drawn from the National Alcohol Survey (n = 4774).

Measurement  Alcohol consumption, demographic, cancer diagnosis, treatment and psychosocial factors were measured.

Findings  Compared to peers, survivors were slightly less likely to be risky [adjusted odds ratio (ORadj) = 0.9; confidence interval (CI) 0.8–1.0] and heavy drinkers (ORadj = 0.8; CI 0.7–0.9) and more likely to be current drinkers. Compared to siblings, survivors were less likely to be current, risky and heavy drinkers. Risk factors for survivors' heavy drinking included being age 18–21 years (ORadj = 2.0; 95% CI 1.5–2.6), male (ORadj = 2.1; 95% CI 1.8–2.6), having high school education or less (ORadj = 3.4; 95% CI 2.7–4.4) and drinking initiation before age 14 (ORadj = 6.9; 95% CI 4.4–10.8). Among survivors, symptoms of depression, anxiety or somatization, fair or poor self‐assessed health, activity limitations and anxiety about cancer were associated with heavy drinking. Cognitively compromising treatment, brain tumors and older age at diagnosis were protective.

Conclusions  Adult survivors of childhood cancer show only a modest reduction in alcohol consumption compared to peers despite their more vulnerable health status. Distress and poorer health are associated with survivor heavy drinking. Screening for alcohol consumption should be instituted in long‐term follow‐up care and interventions among survivors and siblings should be established to reduce risk for early drinking.
A prospective audit of regional anaesthesia failure in 5080 Caesarean sections*
Authors: Kinsella S. M.
Published: June 2008

Anaesthesia for Caesarean section was audited over a 5 year period: 5080 cases were performed using spinal 63%, epidural top‐up 26%, combined spinal‐epidural 5% and primary general anaesthesia 5%. The rate of general anaesthesia conversion of regional anaesthesia was 0.8% for elective and 4.9% for emergency Caesarean section compared to Royal College of Anaesthetists targets of 1% and 3%. The rate of conversion of regional to general anaesthesia in category 1 Caesarean section was 20%. A total of 8% of women had general anaesthesia when both primary general and conversion of regional anaesthesia were combined. The rate of failure to achieve a pain‐free operation was 6% with spinals, 24% with epidural top‐up and 18% with combined spinal‐epidural. Besides the type of anaesthesia and operative urgency, other factors associated with pre‐operative failure of regional anaesthesia included body mass index, no previous Caesareans, and indication for Caesarean of acute fetal distress or maternal medical condition. Inadequacy of pre‐operative anaesthetic block and duration of surgery were important risk factors for intra‐operative failure. For spinal anaesthesia, use of a spinal opioid was associated with less pre‐operative failure. For epidural top‐up anaesthesia, lower epidural top‐up volume was associated with less pre‐operative failure, and use of adrenaline was associated with both less pre‐operative and intra‐operative failure. The rate of serious adverse incidents was 1 : 126 with general anaesthesia and 1 : 501 with regional anaesthesia.
Syntaxin‐11 is expressed in primary human monocytes/macrophages and acts as a negative regulator of macrophage engulfment of apoptotic cells and IgG‐opsonized target cells
Authors: Zhang Shouting , Ma Daoxin , Wang Xiangling , Celkan Tiraje , Nordenskjöld Magnus , Henter Jan‐Inge , Fadeel Bengt , Zheng Chengyun
Published: June 2008

Syntaxin‐11 is a member of a family of membrane‐trafficking proteins referred to as soluble N‐ethylmaleimide‐sensitive factor attachment protein receptors (SNAREs). Recent studies have shown that syntaxin‐11 is expressed in natural killer cells and cytotoxic T cells and is likely to play a role in the granule exocytosis pathway. However, the biological role of syntaxin‐11 in other immune cells has remained elusive. This study found that stimulation with interferon‐γ upregulated syntaxin‐11 expression in primary monocytes. Experiments using monocytes from patients with familial haemophagocytic lymphohistiocytosis harbouring mutations in the gene encoding syntaxin‐11 (STX11), or monocytes from healthy individuals in which syntaxin‐11 was downregulated using specific short‐interfering RNA, demonstrated that syntaxin‐11 was not required for antibody‐dependent cellular cytotoxicity. On the other hand, silencing of syntaxin‐11 expression in primary macrophages enhanced the phagocytosis of apoptotic target cells with a concomitant increase in macrophage secretion of tumour necrosis factor‐α. Moreover, Fcγ‐receptor‐mediated uptake of target cells was also enhanced following silencing of syntaxin‐11 expression in macrophages. In addition, syntaxin‐11 localized to the plasma membrane in macrophages ingesting apoptotic cell corpses. Syntaxin‐11 thus appears to act as a negative regulator of human macrophage engulfment of apoptotic cells and IgG‐opsonized red blood cells.
Reliability of the MDRD method for estimating glomerular filtration rate in relation to gender, body mass index and extracellular fluid volume
Authors: Bird N. J. , Peters C. , Michell A. R. , Peters A. M.
Published: June 2008

Background The accuracy of estimating glomerular filtration rate from plasma creatinine (eGFR) has been questioned but it is unclear how much covert error in several reference methods that have been used has contributed to this perceived inaccuracy. The aim of the study was to evaluate eGFR in comparison with a second ‘gold standard’ to test the performance of the primary gold standard and to examine the influence of patient demographics (age, body mass index (BMI), extracellular fluid volume (ECV) and gender).

Design Non‐fasting multisample GFR and ECV were measured in 80 subjects simultaneously and independently with Cr‐51‐EDTA (GFREDTA) and iohexol (GFRiohexol). Percentage bias and imprecision in the prediction of, and disagreement with, GFREDTAwere compared between eGFR and GFRiohexol. Another simplified method for measuring GFR, the slope‐only method (SOGFR), was also evaluated against multisample GFR (measured with the opposing indicator). Accuracies were assessed in all subjects and across age, BMI and ECV boundaries of 65 y, 29 kg m−2and 14 L.

Results eGFR was less precise than GFRiohexol(imprecisions of 22·3% and 12·9%;P < 0·01). The precision ofSOGFR was intermediate between eGFR and GFRiohexol. Both GFRiohexoland eGFR were less precise in the elderly, the obese and men, but minimally influenced by ECV.SOGFR was minimally influenced by subject demographics.

Conclusion Although eGFR does not predict GFR (based on a primary gold standard) as accurately as a second gold standard, a significant component of its poor performance is the result of inaccuracy in the primary gold standard.SOGFR measured with Cr‐51‐EDTA is superior to eGFR.
Exogenous nitric oxide regulates activity and synthesis of vascular endothelial nitric oxide synthase
Authors: Schmidt A. , Bilgasem S. , Lorkowski S. , Vischer P. , Völker W. , Breithardt G. , Siegel G. , Buddecke E.
Published: June 2008

Background  Nitric oxide (NO) – a major signalling molecule of the vascular system – is constitutively produced in endothelial cells (EC) by the endothelial NO synthase (eNOS). Since a reduced NO synthesis is an early sign of endothelial dysfunction and NO delivering drugs are used to substitute the impaired endothelial NO production, we addressed the effect of exogenous NO on eNOS in human umbilical venous endothelial cell cultures.

Materials and methods  The synthetic NO donor DETA/NO (trade name, but in the following we refer to detNO), that releases NO in a strictly first order reaction with a half life of 20 h, was used in our experiments.

Results  Short‐term (20–30 min) detNO treatment of EC increases the Ser1177 phosphorylation of the constitutively expressed endothelial NOS and the production of endogenous NO generated by eNOS from [3H]arginine. The phosphorylation of eNOS is Akt‐dependent and completely reverted by the phosphatidylinositol‐3 kinase (PI‐3K) inhibitor LY294002. A prolonged continuous exposure of EC to detNO 150 µmol L−1 over a period of 24–48 h causes a reversible cell cycle arrest at G1‐phase associated with a larger cell volume and increased cell protein content (hypertrophic phenotype of EC). The eNOS protein and mRNA of the hypertrophic cells and the generation of endogenous NO are reduced but eNOS phosphorylation could still be elevated by stimulation with vascular endothelial growth factor.

Conclusions  Our data explain clinical studies describing a short‐term but not a long‐term benefit of NO treatment for patients with cardiovascular risk factors. The results could be a rational approach to develop a generation of NO donors accomplishing a retarded release from NO donors that mimic the low continuous pulsatile stress‐induced release of endogenous NO.
Sex and muscle structural lipids in obese subjects – an impact on insulin action?
Authors: Haugaard S. B. , Vaag A. , Høy C.‐E. , Madsbad S.
Published: June 2008

Background   Long‐chain polyunsaturated fatty acid (LCPUFA) especially the n‐3‐FA of skeletal muscle phospholipids may facilitate insulin action, whereas saturated and trans‐FA act oppositely. Community studies show that non‐diabetic weight matched obese men and women display similar insulin resistance, despite the fact that an android fat distribution is detrimental to insulin action. The increased extramyocellular fat mass of obese women may act in a paracrine manner such that its release of free FA and cytokines may hamper in situ desaturation and elongation of FA in skeletal muscle phospholipids.

Material and methods   To test the hypothesis that obese women may display an inferior FA composition compared to obese men, the FA composition of skeletal muscle phospholipids was determined in vastus lateralis biopsies obtained from 12 non‐diabetic obese women with a typical gynoid fat distribution, nine non‐diabetic obese men with a typical android fat distribution and 12 (seven females) lean age matched healthy controls (body mass index 34·6 ± 1·0 kg m−2, 36·5 ± 1·2 and 22·5 ± 0·5; age 47 ± 2 years, 51 ± 3 and 49 ± 2).

Results   Obese women displayed decreased LCPUFA n‐3 and ratio of n‐3/n‐6 PUFA, whereas trans‐FA and palmitic‐FA (C16 : 0) were increased compared to obese men and controls (all Ps < 0·05). Plasma high‐density lipoprotein cholesterol (HDL‐C), triglycerides and a marker of insulin sensitivity were similar between obese women and men but impaired compared to controls (Ps < 0·05).

Conclusions   The data support the hypothesis that insulin resistant non‐diabetic obese men display a more optimal skeletal muscle phospholipid FA composition than their female counterparts, which may be a mechanism to compensate the detrimental effect on insulin action of an android fat distribution.
CANu1, a novel nucleolar protein, accumulated on centromere in response to DNA damage
Authors: Sihn Choong‐Ryoul , Lee Yeon‐Su , Jeong Jin‐Sook , Park Kyunghee , Kim Sang Hoon
Published: June 2008

Single nucleotide polymorphism is known to be an ideal marker to detect human diseases. We isolated a novel human gene, to be called as CANu1, by the large‐scale genome‐wide association analysis to screen specific Single nucleotide polymorphisms in colon cancer. It is mapped to chromosome 14q11.2 and its transcript contains a 948‐nt open reading frame encoding a protein of 315 aa. Here, we observed that green fluorescence protein (GFP)‐fused CANu1 protein was localized to nucleoli and the C‐termini of CANu1 protein were essential for its localization. Moreover, the silencing of the CANu1 gene by siRNA caused ribosomal stress leading to G1 cell cycle arrest, the induction of p53 protein, and the translocation of B23 protein. In addition, CANu1 protein was translocated from nucleolus to nuclear foci in response to UV damage. Interestingly, the mobility of a GFP‐CANu1 protein in the UV damaged cells was two times faster than non‐irradiated cells. Taken together, we report that a novel nucleolar protein, CANu1, is essential to maintain ribosomal structure and responsive upon UV damage.
Using an airgun array in a land reservoir as the seismic source for seismotectonic studies in northern China: experiments and preliminary results
Authors: Chen Yong , Liu Lanbo , Ge Hongkui , Liu Baojun , Qiu Xuelin
Published: June 2008

This paper reports the field setup and preliminary results of experiments utilizing an airgun array in a reservoir in north China for a seismotectonic study. Commonly used in offshore petroleum resource exploration, the airgun source was found to be more useful than a traditional explosive source for large‐scale and long offset land seismic surveys. The airgun array, formed by four 1,500 in3 airguns (a total of 6,000 in3 in volume) was placed at a depth of 6–9 m into the reservoir to generate the pressure impulse. No direct evidence was found that the airgun source adversely affected the fish in the reservoir. The peak ground acceleration recorded on the top of the reservoir dam 100 m away was 17.8 gal in the horizontal direction; this is much less than the designed earthquake‐resistance threshold of 125 gal for this dam. The energy for one shot of this airgun array is about 6.68 MJ, equivalent to firing a 1.7 kg explosive. The seismic waves generated by the airgun source were recorded by receivers of the regional seismic networks and a temporary wide‐angle reflection and refraction profile formed by 100 short‐period seismometers with the maximum source‐receiver offset of 206 km. The seismic wave signature at these long‐offset stations is equivalent to that generated by a traditional blast source in a borehole with a 1,000–2,000 kg explosive. Preliminary results showed clear seismic phases from refractions from the multi‐layer crustal structures in the north China region. Forward modelling using numerical simulation confirms that the seismic arrivals are indeed from lower crustal interfaces. The airgun source is efficient, economical, environmentally friendly and suitable for being used in urbanized areas. It has many advantages over an explosive source for seismotectonic studies such as the high repeatability that is supreme for stacking to improve signal qualities. The disadvantage is that the source is limited to existing lakes or reservoirs, which may restrict experimental geometry.
Merging active and passive data sets in traveltime tomography: The case study of Campi Flegrei caldera (Southern Italy)
Authors: Battaglia Jean , Zollo Aldo , Virieux Jean , Dello Iacono Dario
Published: June 2008

We propose a strategy for merging both active and passive data sets in linearized tomographic inversion. We illustrate this in the reconstruction of 3D images of a complex volcanic structure, the Campi Flegrei caldera, located in the vicinity of the city of Naples, southern Italy. The caldera is occasionally the site of significant unrests characterized by large ground uplifts and seismicity. The P and S velocity models of the caldera structure are obtained by a tomographic inversion based on travel times recorded during two distinct experiments. The first data set is composed of 606 earthquakes recorded in 1984 and the second set is composed of recordings for 1528 shots produced during the SERAPIS experiment in 2001. The tomographic inversion is performed using an improved method based on an accurate finite‐difference traveltime computation and a simultaneous inversion of both velocity models and earthquake locations. In order to determine the adequate inversion parameters and relative data weighting factors, we perform massive synthetic simulations allowing one to merge the two types of data optimally. The proper merging provides high resolution velocity models, which allow one to reliably retrieve velocity anomalies over a large part of the tomography area. The obtained images confirm the presence of a high P velocity ring in the southern part of the bay of Pozzuoli and extends its trace inland as compared to previous results. This annular anomaly represents the buried trace of the rim of the Campi Flegrei caldera. Its shape at 1.5 km depth is in good agreement with the location of hydrothermalized lava inferred by gravimetric data modelling. The Vp/Vs model confirms the presence of two characteristic features. At about 1 km depth a very high Vp/Vs anomaly is observed below the town of Pozzuoli and is interpreted as due to the presence of rocks that contain fluids in the liquid phase. A low Vp/Vs body extending at about 3–4 km depth below a large part of the caldera is interpreted as the top of formations that are enriched in gas under supercritical conditions.
Depth and morphology of reflectors from the non‐linear inversion of arrival‐time and waveform semblance data. Part I: method and applications to synthetic data
Authors: Vassallo Maurizio , Zollo Aldo
Published: June 2008

We propose a two‐dimensional, non‐linear method for the inversion of reflected/converted traveltimes and waveform semblance designed to obtain the location and morphology of seismic reflectors in a lateral heterogeneous medium and in any source‐to‐receiver acquisition lay‐out. This method uses a scheme of non‐linear optimization for the determination of the interface parameters where the calculation of the traveltimes is carried out using a finite‐difference solver of the Eikonal equation, assuming an a priori known background velocity model. For the search for the optimal interface model, we used a multiscale approach and the genetic algorithm global optimization technique. During the initial stages of inversion, we used the arrival times of the reflection phase to retrieve the interface model that is defined by a small number of parameters. In the successive steps, the inversion is based on the optimization of the semblance value determined along the calculated traveltime curves. Errors in the final model parameters and the criteria for the choice of the best‐fit model are also estimated from the shape of the semblance function in the model parameter space. The method is tested and validated on a synthetic dataset that simulates the acquisition of reflection data in a complex volcanic structure. This study shows that the proposed inversion approach is a valid tool for geophysical investigations in complex geological environments, in order to obtain the morphology and positions of embedded discontinuities.
Potential and limits of double‐difference tomographic methods
Authors: Got Jean‐Luc , Monteiller Vadim , Virieux Jean , Operto Stéphane
Published: June 2008

Double‐difference tomographic methods use directly accurate time delays computed between similar signals. Such methods are designed to image very heterogeneous media, such as volcanoes or fault zones. In seismological applications, similar signals are recorded at a given station from earthquakes sharing similar and close‐by sources. In seismic exploration experiments, similar signals are often recorded at neighbouring receivers. After a brief presentation of the tomographic algorithm used, a seismological application is summarized. The potential and limits of double‐difference tomographic methods are explored using various numerical experiments. They show that two effects are competing in double‐difference tomography: (i) the degradation of the stability of the inversion due to the geometrical proximity of the rays used in the differentiation and (ii) the decrease in modelling error, which allows improving the stability of the inversion and using smaller quantities of a priori information when data are sufficiently accurate. The best resolution is obtained for an optimal value of the inter‐source or inter‐receiver distance. For optimal values of these distances and a priori information, tomography using traveltime differences provides significantly better resolved results than using traveltimes.
First‐arrival traveltime tomography using second generation wavelets
Authors: Delost Matthieu , Virieux Jean , Operto Stéphane
Published: June 2008

Wavelet decomposition of the slowness model allows a multiscale description of the seismic first‐arrival time tomography. We propose the introduction of the so‐called second generation wavelets that could be used for any mesh structure and do not require a number of samples, such as the power of two in each direction for fast wavelet transform. A linearized procedure for inverting delayed travel‐times considering either slowness coefficients or wavelet coefficients has been set up with an efficient ray tracing at each iteration of the inversion procedure. Wavelet decomposition over constant patches (Haar wavelet) or over linear patches (Battle‐Lemarie wavelet) of coefficients at different scales are inverted as unknowns of the tomographic linearized system. Reconstruction of these coefficients depends dynamically on the local resolution when considering dense ray coverage. On simple synthetic examples, it has been found necessary to perform a local resolution analysis for specifying wavelet coefficients to be inverted. This resolution analysis could be performed for an initial smooth reconstructed medium and by designing a bit mask operator it allows fine scales to be inverted in specific areas of the model where the resolution is high while not being inverted in other areas where the resolution is poor: the wavelet decomposition will ease the multiscale reconstruction. A few synthetic examples, such as crosshole tomography or surface‐surface tomography illustrate the multiscale feature of wavelet tomography. The second generation wavelet approach seems to be a flexible and rather promising tool for controlling the resolution variation of seismic first‐arrival tomography.
Three‐dimensional kinematic depth migration of converted waves: application to the 2002 Molise aftershock sequence (southern Italy)
Authors: Latorre Diana , De Gori Pasquale , Chiarabba Claudio , Amato Alessandro , Virieux Jean , Monfret Tony
Published: June 2008

Migration techniques, currently used in seismic exploration, are still scarcely applied in earthquake seismology due to the poor source knowledge and sparse, irregular acquisition geometries. At the crustal scale, classical seismological studies often perform inversions based on the arrival time of primary phases (P‐ and S‐waves) but seldom exploit other information included in seismic records. Here we show how migration techniques can be adapted to earthquake seismology for converted wave analysis. As an example, we used data recorded by a dense local seismic network during the 2002 Molise aftershock sequence. In October and November 2002, two moderate magnitude earthquakes struck the Molise region (southern Italy), followed by an aftershock sequence lasting for about one month. Local earthquake tomography has provided earthquake hypocenter locations and three‐dimensional models of P and S velocity fields. Strong secondary signals have been detected between first‐arrivals of P‐ and S‐waves and identified as SP transmitted waves. In order to analyse these waves, we apply a prestack depth migration scheme based on the Kirchhoff summation technique. Since source parameters are unknown, seismograms are equalized and only kinematic aspects of the migration process are considered. Converted wave traveltimes are calculated in the three‐dimensional (3D) tomographic models using a finite‐difference eikonal solver and back ray tracing. In the migrated images, the area of dominant energy conversion corresponds to a strong seismic horizon that we interpreted as the top of the Apulia Carbonate Platform and whose geometry and position at depth is consistent with current structural models from existing commercial seismic profiles, gravimetric and well data.
Histological evaluation of direct pulp capping with a self‐etching adhesive and calcium hydroxide on human pulp tissue
Authors: Lu Y. , Liu T. , Li H. , Pi G.
Published: June 2008

Aim  To evaluate human pulp tissue response following direct pulp capping with a self‐etching adhesive: Clearfil SE BOND (SB).

Methodology  Forty‐five sound teeth from 20 subjects were used. Forty‐one teeth had their pulp mechanically exposed at the base of a Class 1 cavity preparation and were divided into two groups: group 1, teeth were capped with SB (n = 21), and group 2, with calcium hydroxide cement (CH) (n = 20). Four teeth were maintained intact as an untreated control group. After 7, 30 and 90 days, respectively, 15 teeth were extracted and processed for light microscopic examination. Pulp healing and bacterial microleakage were assessed by haematoxylin and eosin, Masson trichrome and Brown and Brenn stain techniques. The data were analysed statistically by using the Mann–Whitney U test.

Results  After the 7‐day observation period, the inflammatory reaction in the SB group was slight and significantly less severe than that of the CH group (P < 0.05). After the 30‐ and 90‐day observation periods, the inflammatory reaction was slight in both groups, but specimens with dentine bridge formation in the SB group were significantly less common than those in the CH group (P < 0.05).

Conclusions  Clearfil SB had good biocompatibility with human pulp tissue, but its ability to induce reparative dentine was significantly lower than that of calcium hydroxide.
Do bioactive glasses convey a disinfecting mechanism beyond a mere increase in pH?
Authors: Gubler M. , Brunner T. J. , Zehnder M. , Waltimo T. , Sener B. , Stark W. J.
Published: June 2008

Aim  To test whether bioactive glasses kill microbiota via mineralization or the release of ions other than sodium.

Methodology  Flame‐spray synthesis was applied to produce nanometric glasses of different sodium content and constant Ca/P ratio: 28S5, 45S5 and 77S. Calcium hydroxide and nanometric tricalcium phosphate (TCP) were used as controls. Apatite induction was monitored by Raman spectroscopy. Bovine dentine disks with adherent Enterococcus faecalis cells were exposed to test and control suspensions or buffered solutions for 1 h, 1 day and 1 week. Colony‐forming units were counted and disks were inspected using scanning electron microscopy. Suspension supernatants and solutions were analysed for their pH, osmolarity, calcium and silicon content.

Results  Sodium containing glasses induced pH levels above 12, compared with less than pH 9 with sodium‐free 77S. Calcium hydroxide, 45S5 and 28S5 killed all bacteria after 1 day and lysed them after 1 week. TCP caused the highest apatite induction and substantial calcification on bacteria adhering to dentine, but did not reduce viable counts. 77S achieved disinfection after 1 week without visible apatite formation, whilst the buffer solution at pH 9 caused only minimal reduction in counts.

Conclusion  Bioactive glasses have a directly and an indirectly pH‐related antibacterial effect. The effect not directly linked to pH is because of ion release rather than mineralization.
Technical quality of root fillings performed by dental students at the dental teaching centre in Reims, France
Authors: Moussa‐Badran S. , Roy B. , Bessart du Parc A. S. , Bruyant M. , Lefevre B. , Maurin J. C.
Published: June 2008

Aim  To evaluate the technical quality of root fillings performed by undergraduate students at a dental teaching centre in France.

Methodology  A random sample of 419 records of patients who received dental treatment at the dental service of the teaching Hospital, in Reims, France between 2005 and 2006 was investigated. Evaluation of root filled was based on radiographical criteria defined by the French National Health Service. The length of root fillings, the radiodensity and the presence of voids in the root filling or between root filling and root canal walls were recorded and scored. Chi‐square analysis was used to determine statistically significant differences between the technical quality of root fillings and tooth type.

Results  Of the 304 teeth included in the study, 69% had an adequate length of root filling and 42.7% had a dense root filling without voids; only 30.3% of teeth fulfilled these criteria at the same time. The relationship between the technical quality of root fillings and tooth type was statistically significant (P < 0.001), the highest percentage of adequate root fillings occurred in single‐rooted teeth (36.1%). The highest percentage of inadequate root fillings according to the criteria of root filling length and lateral adaptation was found in molar teeth (71.9%).

Conclusion  Overall, the technical quality of root fillings performed by undergraduate students was poor.
Determination of pulp vitality in vivo with pulse oximetry
Authors: Calil E. , Caldeira C. L. , Gavini G. , Lemos E. M.
Published: June 2008

Aim  To evaluate the use of pulse oximetry as a test for pulp vitality, by comparing in the same patient, the levels of oxygen saturation of the index finger and of the maxillary central incisor and canine teeth without clinically detectable pulp inflammation.

Methodology  Seventeen male and female patients aged between 26 and 38 years participated and a total of 32 maxillary central incisor and 32 canine teeth were analysed. Selection criteria required the teeth to have healthy crowns, or with restorations no more than 2 mm in diameter and no clinical and radiographical signs or symptoms of pulp or periapical inflammatory changes. The negative control group consisted of 10 root filled teeth. Measurements were first taken from the index finger of patients. Their teeth were then subjected to a thermal test with refrigerant gas and then to a vitality test with pulse oximetry. Data were analysed by Pearson’s and paired t‐tests.

Results  There were no significant statistical correlations between blood oxygen levels in the index finger and in the teeth of the patient (P > 0.05). There was a statistically significant difference in the oxygen levels between the two tooth groups studied and the index finger (P ≤ 0.002). Mean oxygen values in the index finger of patients were 95% (SD = 1.6), oxygen values in the maxillary central incisor were 91.29% (SD = 2.61) and mean oxygen values in maxillary canine were 90.69% (SD = 2.71).

Conclusion  The method determined consistently the level of blood oxygen saturation of the pulp in maxillary central incisor and canine teeth and can therefore be used for pulp vitality testing. Further studies are required to assess the effectiveness and validity of pulse oximetry in determining pulp vitality in traumatized teeth.
Opinions and attitudes of endodontists and general dental practitioners in the UK towards the intracanal fracture of endodontic instruments: part 1
Authors: Madarati A. A. , Watts D. C. , Qualtrough A. J. E.
Published: June 2008

Aim  To investigate the attitudes and opinions of general dental practitioners (GDPs) and endodontists in the UK towards fracture of endodontic instruments. It was hypothesized that there would be no significant difference between GDPs and endodontists regarding their experience of fracture of endodontic instruments.

Methodology  A pilot questionnaire was carried out on 20 postgraduate dental students to ensure that the questions were easily understood. This was followed by a further pilot survey on a group of GDPs and endodontists (50) to facilitate sample size calculation. The sample size comprised 330 systematically selected GDPs, and all endodontic specialists working in the UK (170). The questionnaire comprised both close‐ended and partially close‐ended questions in four categories: demographics; pattern of practice and experience of instrument fracture; management of fractured instruments; and unsuccessful management of fractured instruments. Nonrespondents were sent another two mailings (first and second reminders). After collecting the responses, data were analysed using chi‐square and Linear‐by‐Linear Association tests at the 0.05 level of significance.

Results  The overall response rate was 75% (82.82% for endodontists and 70.92% for GDPs). Overall, 88.8% of respondents had experienced fractured instruments with a significantly higher proportion of endodontists (94.8%) compared with that of GDPs (85.1%).

Conclusion  Both endodontists and GDPs were aware of most factors contributing to endodontic instrument fracture. With experience and knowledge, fracture of endodontic instruments was associated with the number of root canal treatments performed.
The determinants of nurses’ therapeutic attitude to patients who use illicit drugs and implications for workforce development
Authors: Ford Rosemary , Bammer Gabriele , Becker Niels
Published: June 2008

Aim.  To examine the determinants of generalist nurses’ therapeutic attitude to patients who use illicit drugs, and to model workforce development initiatives.

Background.  Individuals who use illicit drugs rely heavily on healthcare in emergency departments and inpatient hospital wards. Little is known about the determinants of generalist nurses’ therapeutic attitude to provide care, therefore limiting our understanding of the important issues for workforce development.

Design.  The study was a cross‐sectional survey of registrants on the Australian Capital Territory Nurses Registration Roll 2002 (N = 3241, 50% response rate). The associations between variables and nurses’ therapeutic attitude were examined by multi‐variable linear regression analysis.

Method.  Nurses’ therapeutic attitude was assessed using a modified version of the Alcohol and Alcohol Problems Perception Questionnaire. Personal characteristics, attitudes to illicit drugs and professional practice variables such as drug and alcohol education, experience with the patient group and role support were examined using a mix of standardised and new questions.

Results.  Professional practice variables explained 53% of the variation of nurses’ therapeutic attitude, the most important being role support. Although a negative attitude to illicit drugs had a statistically significant association with therapeutic attitude, it added less than 1% to the variation explained. Personal characteristics showed no association.

Conclusions.  Generalist nurses struggle to provide care to this patient group. Role support was found to be the strongest driver of nurses’ therapeutic attitude, and workplace illicit drug education was only useful in combination with high role support.

Relevance to clinical practice.  Nurses’ caring role with patients who use illicit drugs is complex and demanding. Nursing workforce development must focus on increasing nurses’ role support, in terms of appropriately skilled staff readily available for consultation and advice. Support for nurses, in the form of evidence‐based practice standards and appropriate time allocation, is also important.
Association of spinal deformity and vaccine‐induced abdominal lesions in harvest‐sized Atlantic salmon, Salmo salar L.
Authors: Aunsmo A , Guttvik A , Midtlyng P J , Larssen R B , Evensen Ø , Skjerve E
Published: June 2008

Spinal deformities in Atlantic salmon, Salmo salar L., have been described as a disease of multifactorial origin for which vaccines and time of vaccination have been suggested as risk factors. A vaccine efficacy trial where spinal deformity became evident was continued by the observational study reported here. In the preharvest part of the study 17 months post‐sea transfer, there was a prevalence of 11.3% spinal deformity, with deformities present only in one vaccine group indicating a strong vaccine involvement. At slaughter, the prevalence of spinal deformities was 11.7%, and deformed fish had only 62% of normal slaughter weight. Visual analogue scales (VAS) were used for continuous recordings of vaccine‐induced abdominal lesions and deformity. A logistic regression model associating presence of spinal deformity with markers of abdominal lesions was developed. The odds ratio for spinal deformity was 5.7 (95% CI: 3.4–9.4) for each unit increase in adhesion score (0–6) and 4.9 (2.9–3.4) for each unit increase in melanin on abdominal organs (0–3). Lesions in the dorsal caudal part of the abdomen gave an odds ratio for spinal deformity of 2.2.
Effect of dietary administration of Porphyridium cruentum on the respiratory burst activity of sole, Solea senegalensis (Kaup), phagocytes
Authors: Díaz‐Rosales P , Chabrillón M , Abdala R T , Figueroa F L , Balebona M C , Moriñigo M A
Published: June 2008

The stimulatory effect of the red microalga Porphyridium cruentum on respiratory burst activity of sole phagocytes was evaluated in vivo. Oral administration of a diet supplemented with lyophilized P. cruentum cells (10 g kg−1) stimulated respiratory burst activity after 4 weeks feeding in sole vaccinated with Photobacterium damselae subsp. piscicida bacterin.
Plasmodium falciparum origin recognition complex subunit 5: functional characterization and role in DNA replication foci formation
Authors: Gupta Ashish , Mehra Parul , Dhar Suman Kumar
Published: June 2008

The mechanism of DNA replication initiation and progression is poorly understood in the parasites, including human malaria parasite Plasmodium falciparum. Using bioinformatics tools and yeast complementation assay, we identified a putative homologue of Saccharomyces cerevisiaeorigin recognition complex subunit 5 in P. falciparum (PfORC5). PfORC5 forms distinct nuclear foci colocalized with the replication foci marker proliferating cell nuclear antigen (PfPCNA) and co‐immunoprecipitates with PCNA during early‐to‐mid trophozoite stage replicating parasites. Interestingly, these proteins separate from each other at the non‐replicating late schizont stage, citing the evidence of the presence of both PCNA and ORC components in replication foci during eukaryotic DNA replication. PfORC1, another ORC subunit, colocalizes with PfPCNA and PfORC5 at the beginning of DNA replication, but gets degraded at the late schizont stage, ensuring the regulation of DNA replication in the parasites. Further, we have identified putative PCNA‐interacting protein box in PfORC1 that may explain in part the colocalization of PfORC and PfPCNA. Additionally, use of specific DNA replication inhibitor hydroxyurea affects ORC5/PCNA foci formation and parasitic growth. These results strongly favour replication factory model in the parasites and confer great potential to understand the co‐ordination between ORC and PCNA during eukaryotic DNA replication in general.