bluuebunny/crossref_metadata_2025 huggingface dataset:
Combined Esophageal Multichannel Intraluminal Impedance and pH Monitoring After Repair of Esophageal Atresia
Authors: Fröhlich Thorsten , Otto Stephanie , Weber Peter , Pilic Denisa , Schmidt‐Choudhury Anjona , Wenzl Tobias G , Köhler Henrik
Published: October 2008

Objective:

Gastroesophageal reflux disease and impaired esophageal motility is a frequent problem after repair of esophageal atresia (EA). Combined multichannel intraluminal impedance (MII) and pH measurement identifies acidic and weakly acidic esophageal bolus movements. Our aim was to evaluate gastroesophageal reflux and its association with gastrointestinal or extraintestinal symptoms using combined MII‐pH measurement.

Patients and Methods:

In all, 24 patients (4 months–23 years; 17 male, 7 female) with repaired EA were included in this study. A single catheter with 6 impedance channels and 1 pH channel was used to perform the 24‐hour MII‐pH study. Symptoms were recorded during the study as events and with a standardized questionnaire. In a subgroup of patients, an impedance swallowing test evaluating liquid and viscous bolus movements was performed.

Results:

We detected a total of 911 episodes of retrograde bolus movement, 379 acidic and 532 weakly acidic bolus movements. In all, 201 symptom events were recorded. Of these events, 42% were associated with retrograde bolus movements. More symptom events were associated with weakly acidic reflux (26%) than with acid reflux episodes (16%). There was a poor correlation between symptoms and MII‐pH study findings. In comparison with patients without esophageal surgery, EA patients showed significantly fewer complete swallows of liquid (42% vs 98%) and viscous material (18% vs 87%).

Conclusions:

In patients with corrected EA, half of the reflux events could be detected only by MII. We also demonstrated that weakly acidic reflux can be responsible for the patients' symptoms. However, patients may have few or no symptoms despite poor esophageal function and extensive gastroesophageal reflux disease.
Effects of Infliximab and Parenteral Nutrition on Albumin and Fibrinogen Synthesis Rates in Pediatric Crohn Disease
Authors: Steiner Steven J , Pfefferkorn Marian D , Fitzgerald Joseph F , Denne Scott C
Published: October 2008

Objectives:

Tumor necrosis factor‐α (TNF‐α) may play a significant role in growth disturbance in pediatric Crohn disease. The aim of this study was to determine the effects of anti‐TNF‐α therapy on albumin and fibrinogen synthesis during both fasting and parenteral nutrition infusion in pediatric patients with active Crohn disease.

Patients and Methods:

Children with active Crohn disease scheduled for their initial dose of infliximab underwent assessment immediately before and 2 weeks following infliximab infusion. Using the stable isotope [d5] phenylalanine, rates of fractional and absolute albumin and fibrinogen synthesis were calculated. Measurements were made in both the fasting and parenterally fed states.

Results:

Fifteen children (mean age 14.9 ± 0.3) completed the study. The mean serum albumin changed from 3.59 ± 0.08 to 3.66 ± 0.04 g/dL, and the mean fibrinogen level decreased from 230 ± 17 to 187 ± 8 mg/dL (P < 0.05) following infliximab therapy. During fasting, there were no changes in albumin and fibrinogen synthesis rates following infliximab. During parenteral nutrition infusion, the fractional albumin synthesis rate changed from 11.8% to 15.1%/day (P = 0.06), and the absolute albumin synthesis rate increased from 192 to 248 mg · kg−1 · day−1 (P < 0.05), whereas no changes in fibrinogen synthesis rates were observed. Synthesis rates of albumin and fibrinogen were increased during parenteral nutrition infusion compared with the fasting state.

Conclusions:

Following infliximab therapy, during parenteral nutrition infusion, albumin synthesis increased significantly. Conversely, serum fibrinogen levels decreased following infliximab therapy in the absence of significant change in synthesis rates.
Duodenal Bulb Biopsies in Celiac Disease: A Multicenter Study
Authors: Bonamico Margherita , Thanasi Enina , Mariani Paolo , Nenna Raffaella , Luparia Rita Pia Lara , Barbera Cristiana , Morra Isabella , Lerro Pietro , Guariso Graziella , De Giacomo Costantino , Scotta Serenella , Pontone Stefano , Carpino Francesco , Magliocca Fabio Massimo ,   Società Italiana di Gastroenterologica, Epatologia, e Nutrizione Pediatrica
Published: October 2008

Objectives:

Celiac disease (CD)–related lesions have been reported in duodenal bulb biopsies, sometimes the bulb mucosa being the only one affected. The aim was to verify in a significant series whether histological lesions are always present in the bulb of celiac patients, what is the prevalence of lesions when isolated to the bulb, and if similar lesions are present in nonceliac subjects.

Methods:

We studied 665 children with CD (241 males, range 9 months–15 years, 8 months), at diagnosis on a gluten‐containing diet, and 348 age‐ and sex‐matched gastroenterological controls submitted to upper endoscopy for gastroenterological complaints. During endoscopy, multiple biopsies (1 bulb and 4 distal duodenum samples) were taken. Anti‐endomysium antibodies were evaluated by immunofluorescence method, anti–human tissue–transglutaminase antibodies by an enzyme‐linked immunosorbent assay or radioimmunoassay. Human leukocyte antigen‐DRB1, ‐DQA1, and ‐DQB1 genes were typed by polymerase chain reaction sequence–specific primers repeat method.

Results:

In all of the patients with CD, histological lesions were present in the bulb sample; in 16 of them, the lesions were present only in the bulb. Patchy villous atrophy was found in 20 children. All of the patients with CD were anti‐endomysium and/or anti‐transglutaminase positive. The controls showed neither autoantibody positivity nor mucosal changes compatible with CD.

Conclusions:

This study demonstrated that CD‐related histological lesions are always present in the bulb; sometimes this specific site is the only one affected. Therefore, we suggest taking 2 biopsies from the bulb and 2 from the distal duodenum for CD diagnosis.
Induction of Arginase II by Intestinal Epithelium Promotes the Uptake of L‐Arginine From the Lumen ofCryptosporidium parvum–infected Porcine Ileum
Authors: Gookin Jody L , Stauffer Stephen H , Stone Maria R
Published: October 2008

Objectives:

To determine the specific transport system activities and expression of transporter genes responsible for uptake of L‐arginine from the lumen of normal andCryptosporidium parvum–infected neonatal porcine ileum and the influence of L‐arginine catabolic pathways on L‐arginine uptake.

Methods:

Intact sheets of ileal mucosa from control andC parvum–infected neonatal piglets were mounted in Ussing chambers and the uptake of14C‐L‐arginine was determined under initial rate conditions and in the presence of transport system–selective inhibitors. Epithelial expression of L‐arginine transporter genes was quantified by real‐time reverse transcription polymerase chain reaction. L‐Arginine catabolic enzyme expression was examined by immunoblotting epithelial lysates for arginase I and II. The role of intracellular catabolism in promoting the uptake of L‐arginine was determined by pharmacological inhibition of nitric oxide synthase and arginase activities.

Results:

C parvum–infected ileum transported L‐arginine at rates equivalent to uninfected epithelium despite profound villous atrophy. This was attributed to enhanced uptake of L‐arginine by individual epithelial cells in the infection. There were no differences in L‐arginine transport system activities (y+and B0,+) or level of transporter gene expression (CAT‐1, CAT‐2A, and ATB0,+) between uninfected andC parvum–infected epithelial cells. However, infected epithelia had induced expression of the L‐arginine hydrolytic enzyme arginase II and lower concentrations of L‐arginine. Furthermore, transport of L‐arginine by the infected epithelium was significantly inhibited by pharmacological blockade of arginase.

Conclusions:

Intracellular catabolism by arginase II, the induction of which has not been described previously for intestinal epithelium, facilitates uptake of L‐arginine by infected epithelium using transport systems that do not differ from those of uninfected cells. Induction of arginase II may limit nitric oxide synthesis by competing with nitric oxide synthase for utilization of L‐arginine or promote use of L‐arginine for the synthesis of reparative polyamines.
Drug‐related Hepatotoxicity and Acute Liver Failure
Authors: Murray Karen F , Hadzic Nedim , Wirth Stefan , Bassett Mikelle , Kelly Deirdre
Published: October 2008

Drug‐induced acute liver failure (ALF) accounts for approximately 20% of ALF in children and a higher percentage of ALF in adults. Although most patients experience milder drug hepatotoxic reactions such as hepatitis, cholestasis, or asymptomatic enzyme elevation, it is important to recognize the potential for progression to ALF. The most common cause of drug‐induced ALF in children is acetaminophen (15% of all ALF in children in the United Kingdom and the United States), whereas other drugs such as antituberculous and antiepileptic therapy account for 5%. The pathogenesis of liver injury includes direct hepatotoxicity and idiosyncratic reactions for most drugs, although for others the mechanism of injury is assumed on the basis of clinical presentation and hepatic histological findings. We review the adult and pediatric literature of drug‐induced hepatotoxicity and ALF, with special attention to commonly used or offending medications, mechanism of the toxicity, clinical presentation, diagnosis, treatment, and prognosis. Although most of the available information is based on experience in adult patients, we have included that which is applicable to children, or we have cited pediatric examples. Enhanced awareness of the potential hepatotoxicity of commonly prescribed medications may minimize the frequency of serious hepatotoxicity and ALF in pediatric patients.
Irreversible Intestinal Failure: Prevalence and Prognostic Factors
Authors: Diamanti Antonella , Sole Basso Maria , Castro Massimo , Di Ciommo Vincenzo , Bracci Fiammetta , Ferretti Francesca , Pietrobattista Andrea , Gambarara Manuela
Published: October 2008

Background and Aim:

Parenteral nutrition (PN) is the primary treatment for intestinal failure, which is considered irreversible in patients who remain partially or fully dependent on PN. Causes of irreversible intestinal failure are short bowel syndrome (SBS), motility disorders (MD), and severe protracted diarrhea (SPD). The aim of this study was to report the clinical outcome in these patients in relation to the underlying disease.

Patients and Methods:

From January 1, 1989 to December 31, 2006, 218 intestinal failure patients were observed in our center, but only 96 (48 SBS, 39 SPD, and 9 MD) were included because they required at least 50% of their total calories as PN for not less than 3 months. In these patients, survival and complication rates were evaluated.

Results:

The survival rate was significantly higher in SBS patients than in the other groups (P < 0.01). SBS patients showed a higher rate of major complications, although only intestinal failure–associated liver disease was significantly higher (P < 0.001). In our series, MD was the main cause of irreversible intestinal failure.

Conclusions:

The potential for bowel adaptation is higher in surgical than in medical causes of intestinal failure and does not seem to be influenced by complications of intestinal failure. SBS, although worsened by the major number of complications, was not the main category contributing to intestinal failure.
MRI in Identifying Hepatic Steatosis in Obese Children and Relation to Ultrasonography and Metabolic Findings
Authors: Pozzato Carlo , Radaelli Giovanni , Dall'Asta Chiara , Verduci Elvira , Villa Anna , Villa Chiara , Scaglioni Silvia , Riva Enrica , Pontiroli Antonio E , Cornalba Gianpaolo , Giovannini Marcello
Published: October 2008

Objectives:

The aim of this study was to identify nonalcoholic fatty liver in obese children by magnetic resonance imaging (MRI) and to compare the findings with the data from ultrasonography and from clinical and laboratory testing.

Patients and Methods:

Sixty obese children, 6 to 14 years old, underwent hepatic MRI and abdominal ultrasonography. Biochemistry determinations included serum aminotransferases, lipid profile, glucose, and insulin. Anthropometry included body mass index, total and trunk fat, and fat‐free mass obtained by dual‐energy radiographic absorptiometry. Hepatic steatosis, judged as hepatic fat fraction by MRI, was ≥9%.

Results:

By MRI, 14 (23%) children had hepatic steatosis; of those, 5 had a fat fraction of 9% to 18%, and 9 had a fat fraction >18%. At univariate analysis, fat fraction was positively associated with being male, serum alanine aminotransferase, aspartate aminotransferase, and γ‐glutamyltransferase, body mass indexzscore, insulin, systolic pressure, and total and trunk fat mass. Hepatic steatosis was independently associated with alanine aminotransferase (P< 0.01). Overall, liver echogenicity on ultrasonography correlated well with fat fraction by MRI (correlation coefficient 0.527,P< 0.0001). Among the 27 children with increased liver echogenicity, 13 (48%) had hepatic fat fraction ≥9%, and 89% of children with echogenicity graded 2 or 3 had fat fraction >18%. All of the children (n = 9) with fat fraction >18% had increased liver echogenicity, and in 8 of them it was graded 2 or 3, but the MRI fat fraction ranged greatly (28%–45%).

Conclusions:

In obese children, nonalcoholic hepatic steatosis may be associated with the metabolic syndrome. Ultrasonography may be valuable in identifying high hepatic fat accumulation, but its ability to identify lower fat accumulation in the liver is scanty compared with MRI.
Antigliadin Immunoglobulin A Best in Finding Celiac Disease in Children Younger Than 18 Months of Age
Authors: Lagerqvist Carina , Dahlbom Ingrid , Hansson Tony , Jidell Erik , Juto Per , Olcén Per , Stenlund Hans , Hernell Olle , Ivarsson Anneli
Published: October 2008

Objectives:

The aim was to investigate age‐dependent serum levels and occurrence of elevated celiac disease (CD)–related antibodies in young children, to define the optimal serological procedure when selecting for small intestinal biopsy.

Patients and Methods:

Included were 428 children with biopsy verified CD (median age 16 months; range 7.5 months–14 years) and 216 controls (median age 2.7 years; range 8.5 months–14.6 years). Immunoglobulin (Ig) A antibodies against gliadin (AGA‐IgA), tissue transglutaminase (tTG‐IgA), and endomysium (EMA‐IgA) were analysed.

Results:

Increased serum AGA‐IgA levels were found in 411 of 428 CD cases, tTG‐IgA in 385 of 428, and EMA‐IgA in 383 of 428. In the control group, 11 of 216 had increased levels of AGA‐IgA, 5 of 216 of tTG‐IgA, and 8 of 216 of EMA‐IgA. In CD children younger than 18 months, elevated AGA‐IgA occurred in 97% and elevated tTG‐IgA and EMA‐IgA were found in 83% of the cases. Conversely, in CD children older than 18 months, elevated AGA‐IgA occurred in 94%, and elevated tTG‐IgA and EMA‐IgA were found in 99% of the cases.

Conclusions:

In children older than 18 months, both tTG‐IgA and EMA‐IgA are sufficiently accurate to be used as a single antibody marker, whereas a large proportion of younger children with CD lack these antibodies. Therefore, when selecting children for small intestinal biopsy, the detection of a combination of AGA‐IgA and tTG‐IgA is optimal for identifying untreated CD in children younger than 18 months.
Altered Eicosanoid Metabolism in the Cystic Fibrosis Mouse Small Intestine
Authors: De Lisle Robert C , Meldi Lauren , Flynn Maureen , Jansson Kyle
Published: October 2008

Objectives:

Imbalances in essential fatty acid levels have been reported in cystic fibrosis (CF), which may relate to elevated proinflammatory eicosanoid generation. The aim of this work was to better define eicosanoid metabolism in the CF intestine.

Materials and Methods:

We used the small intestine of the cystic fibrosis transmembrane conductance regulator knockout mouse (CF mouse) to measure eicosanoid metabolic gene expression by quantitative reverse transcription polymerase chain reaction and Western blot, and eicosanoid levels by enzyme immunoassay, as compared with wild‐type (WT) littermates.

Results:

In the CF small intestine, expression of the secretory phospholipase A2Pla2g5 mRNA was upregulated to 980% of WT levels. The following were downregulated: leukotriene C4 synthase Ltc4s (mRNA 55% of WT); ω‐hydroxylase cytochrome P450s Cyp2c40 (mRNA 54% of WT), and Cyp4a10 (mRNA 4% of WT); and the major prostaglandin degradative enzymes prostaglandin dehydrogenase Hpgd (mRNA 27% of WT) and leukotriene B4 12‐hydroxydehydrogenase/15‐oxo‐prostaglandin 13‐reductase Ltb4dh (mRNA 64% and protein 30% of WT). The prostaglandins PGE2 and PGF2α were increased to 400% to 600% of WT levels in the CF mouse intestine, and the hydroxyeicosatetraenoic acids (HETEs) 12‐, 15‐, and 20‐HETE were decreased to 3% to 20% of WT levels.

Conclusions:

There are changes in eicosanoid metabolic gene expression that are accompanied by significant changes in specific eicosanoid levels. These changes are expected to play important roles in the pathophysiology of CF in the intestine.
Cytokeratin 18, a Marker of Cell Death, Is Increased in Children With Suspected Nonalcoholic Fatty Liver Disease
Authors: Vos Miriam B , Barve Shirish , Joshi‐Barve Swati , Carew John D , Whitington Peter F , McClain Craig J
Published: October 2008

Objectives:

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with obesity, and is now the most common liver disease in the United States. Cytokeratin 18 (CK18) is an intracellular protein released into the blood by both necrosis and apoptosis of hepatocytes. Levels of CK18 have not been reported previously in children with NAFLD.

Methods:

In a cross‐sectional analysis of 62 children (28 normal weight, 14 obese, and 20 suspected NAFLD), we measured CK18 levels as well as alanine aminotransferase, fasting glucose, fasting insulin, and tumor necrosis factor‐α.

Results:

CK18 was significantly elevated in the children with suspected NAFLD compared with obese controls and normal weight controls (median = 424 U/L compared with 243 and 214 respectively, P < 0.001). In multiple logistic regression analysis, CK18 was the best single predictor of suspected NAFLD (prediction accuracy = 84.1%).

Conclusions:

CK18 is elevated in children with suspected NAFLD and should be investigated as a potential diagnostic marker of NAFLD.
Mast Cell–Nerve Interactions in Children With Functional Dyspepsia
Authors: Schäppi Michela G , Borrelli Osvaldo , Knafelz Daniela , Williams Sue , Smith Virpi V , Milla Peter J , Lindley Keith J
Published: October 2008

Background and Aims:

Functional dyspepsia in childhood is commonly triggered by food allergen in sensitised individuals. We investigated the topography of eosinophils and mast cells in gastric antral lamina propria, the interaction of mast cell products with mucosal nerve fibres, and changes in gastric antral muscle slow wave activity in children with atopy and non–atopy‐related functional dyspepsia.

Patients and Methods:

Open label study of gastric mucosal cow's milk challenge in 10 atopic and 6 nonatopic children (ages 2–12 years) investigated consecutively with gastroscopy for functional dyspepsia. Simultaneous surface electrogastrography and milk challenge were undertaken and laser scanning fluorescence microscopy used to examine the association of mast cell tryptase with mucosal nerves in the gastric mucosa before and after challenge.

Results:

Eosinophils and mast cells within the lamina propria were increased in number in children with atopic functional dyspepsia and degranulated rapidly after cow's milk challenge in the atopic group. For degranulating eosinophils, median = 13.0% (interquartile range = 3.7–31.0) premilk versus 32.0% (12.0–42.0) after milk biopsies (P < 0.05); for degranulating mast cells, 5.35% (2.7–10.9) premilk biopsies versus 18.75% (12.9–22.1) after milk biopsies (P < 0.05). No such differences were seen in nonatopic patients. Mast cells were closely associated with mucosal nerve fibres and released tryptase, which colocalised with proteinase‐activated receptors on mucosal nerve fibres. The gastric antral slow wave became abnormal within 2 minutes of antigen challenge in atopics with an increase in dominant frequency instability coefficient (P < 0.005), decrease in 3 cycles per minute myoelectrical activity (P < 0.01), and increase in bradygastria (P < 0.01).

Conclusions:

Early‐onset neuroimmune interactions induced by cow's milk in the gastric mucosa of atopic children are associated with rapid disturbance of gastric myoelectrical activity and dyspeptic symptoms.
Vocal cues of ovulation in human females
Authors: Bryant Gregory A , Haselton Martie G
Published: October 2008

Recent research has documented a variety of ovulatory cues in humans, and in many nonhuman species, the vocal channel provides cues of reproductive state. We collected two sets of vocal samples from 69 normally ovulating women: one set during the follicular (high-fertility) phase of the cycle and one set during the luteal (low-fertility) phase, with ovulation confirmed by luteinizing hormone tests. In these samples we measured fundamental frequency (pitch), formant dispersion, jitter, shimmer, harmonics-to-noise ratio and speech rate. When speaking a simple introductory sentence, women's pitch increased during high- as compared with low-fertility, and this difference was the greatest for women whose voices were recorded on the two highest fertility days within the fertile window (the 2 days just before ovulation). This pattern did not occur when the same women produced vowels. The high- versus low-fertility difference in pitch was associated with the approach of ovulation and not menstrual onset, thus representing, to our knowledge, the first research to show a specific cyclic fertility cue in the human voice. We interpret this finding as evidence of a fertility-related enhancement of femininity consistent with other research documenting attractiveness-related changes associated with ovulation.
Genome-wide nucleotide-level mammalian ancestor reconstruction
Authors: Paten Benedict , Herrero Javier , Fitzgerald Stephen , Beal Kathryn , Flicek Paul , Holmes Ian , Birney Ewan
Published: October 2008

Recently attention has been turned to the problem of reconstructing complete ancestral sequences from large multiple alignments. Successful generation of these genome-wide reconstructions will facilitate a greater knowledge of the events that have driven evolution. We present a new evolutionary alignment modeler, called “Ortheus,” for inferring the evolutionary history of a multiple alignment, in terms of both substitutions and, importantly, insertions and deletions. Based on a multiple sequence probabilistic transducer model of the type proposed by Holmes, Ortheus uses efficient stochastic graph-based dynamic programming methods. Unlike other methods, Ortheus does not rely on a single fixed alignment from which to work. Ortheus is also more scaleable than previous methods while being fast, stable, and open source. Large-scale simulations show that Ortheus performs close to optimally on a deep mammalian phylogeny. Simulations also indicate that significant proportions of errors due to insertions and deletions can be avoided by not assuming a fixed alignment. We additionally use a challenging hold-out cross-validation procedure to test the method; using the reconstructions to predict extant sequence bases, we demonstrate significant improvements over using closest extant neighbor sequences. Accompanying this paper, a new, public, and genome-wide set of Ortheus ancestor alignments provide an intriguing new resource for evolutionary studies in mammals. As a first piece of analysis, we attempt to recover “fossilized” ancestral pseudogenes. We confidently find 31 cases in which the ancestral sequence had a more complete sequence than any of the extant sequences.
NAC Family Proteins NARS1/NAC2 and NARS2/NAM in the Outer Integument Regulate Embryogenesis inArabidopsis
Authors: Kunieda Tadashi , Mitsuda Nobutaka , Ohme-Takagi Masaru , Takeda Seiji , Aida Mitsuhiro , Tasaka Masao , Kondo Maki , Nishimura Mikio , Hara-Nishimura Ikuko
Published: October 2008

Seed morphogenesis consists of embryogenesis and the development of maternal tissues such as the inner and outer integuments, both of which give rise to seed coats. We show that expression of chimeric repressors derived from NAC-REGULATED SEED MORPHOLOGY1 and -2 (NARS1 and NARS2, also known as NAC2 and NAM, respectively) caused aberrant seed shapes in Arabidopsis thaliana. Double knockout mutant nars1 nars2 exhibited abnormally shaped seeds; moreover, neither nars1 nor nars2 produced abnormal seeds, indicating that NARS1 and NARS2 redundantly regulate seed morphogenesis. Degeneration of the integuments in nars1 nars2 was markedly delayed, while that of the wild type occurred around the torpedo-shaped embryo stage. Additionally, nars1 nars2 showed a defect in embryogenesis: some nars1 nars2 embryos were developmentally arrested at the torpedo-shaped embryo stage. Unexpectedly, however, neither NARS1 nor NARS2 was expressed in the embryo at this stage, although they were found to be expressed in the outer integument. Wild-type pistils pollinated with nars1 nars2 pollen generated normal seeds, while the reverse crossing generated abnormal seeds. Taken together, these results indicate that NARS1 and NARS2 regulate embryogenesis by regulating the development and degeneration of ovule integuments. Our findings suggest that there is an intertissue communication between the embryo and the maternal integument.
Reconstructing three-dimensional shape envelopes from time-resolved small-angle X-ray scattering data
Authors: Lamb Jessica , Kwok Lisa , Qiu Xiangyun , Andresen Kurt , Park Hye Yoon , Pollack Lois
Published: October 2008

Modern computing power has made it possible to reconstruct low-resolution, three-dimensional shapes from solution small-angle X-ray scattering (SAXS) data on biomolecules withouta prioriknowledge of the structure. In conjunction with rapid mixing techniques, SAXS has been applied to time resolve conformational changes accompanying important biological processes, such as biomolecular folding. In response to the widespread interest in SAXS reconstructions, their value in conjunction with such time-resolved data has been examined. The group I intron fromTetrahymena thermophilaand its P4–P6 subdomain are ideal model systems for investigation owing to extensive previous studies, including crystal structures. The goal of this paper is to assay the quality of reconstructions from time-resolved data given the sacrifice in signal-to-noise required to obtain sharp time resolution.
Total-scattering-based automatic centring of capillary samples within powder diffractometers
Authors: Cranswick L. M. D. , Donaberger R. L.
Published: October 2008

A computer-controlled method for the automatic mechanical centring of a powder capillary sample onto the rotation centre of a powder diffractometer, using total scattering of the radiation beam into one-dimensional or two-dimensional detectors, and only a 90° rotation of the sample stage, is described. This method is particularly useful for situations where powder capillaries are within non-ambient experimental apparatus or loadedviaan automatic sample changer. Irregularly shaped samples, potentially subject to absorption effects, are aligned and centred on the sample's `scattering centre'.
AutoSherlock: a program for effective crystallization data analysis
Authors: Nagel Raymond M. , Luft Joseph R. , Snell Edward H.
Published: October 2008

A program,AutoSherlock, has been developed to present crystallization screening results in terms of chemical space. This facilitates identification of lead conditions, rational interpretation of results and directions for the optimization of crystallization conditions.
X-ray tomographic reconstruction of macromolecular samples
Authors: Brockhauser Sandor , Di Michiel Marco , McGeehan John E. , McCarthy Andrew A. , Ravelli Raimond B. G.
Published: October 2008

The anomalous scattering properties of innate sulfur for proteins and phosphorus for DNA and RNA can be used to solve the phase problem in macromolecular crystallography (MX)viathe single-wavelength anomalous dispersion method (SAD). However, this method, which is carried out at longer X-ray wavelengths (1.5–2.5 Å), is still not a routine tool in MX. The increased absorption from both air and sample associated with the use of longer X-ray wavelengths presents a key difficulty. The absorption can be corrected for through empirical algorithms, provided truly redundant data are available. Unfortunately, weakly diffracting macromolecular crystals suffer from radiation damage, resulting in a dose-dependent non-isomorphism which violates the assumption upon which these empirical algorithms are based. In this report, X-ray microtomography is used to reconstruct the three-dimensional shapes of vitrified macromolecular crystals including the surrounding solvent and sample holder. The setup can be integrated within an MX beamline environment and exploits both absorption and phase contrast. The dose needed for the tomographic measurements could be low enough to allow the technique to be used for crystal integrity characterization and alignment. X-ray tomography has some major benefits compared with the optical-light-based crystal alignment protocols currently used.
X-ray powder diffraction quantitative analysis of an amorphous SiO2–poly(methyl methacrylate) nanocomposite
Authors: Riello P. , Munarin M. , Silvestrini S. , Moretti E. , Storaro L.
Published: October 2008

Quantification of individual phases within a multiphase amorphous material has been achieved using a newly developed technique based on X-ray powder diffraction. The quantification method was developed during a study of an amorphous silica–poly(methyl methacrylate) (SiO2–PMMA) hybrid nanocomposite. The efficiency of the method as a quantifying tool for individual phases was demonstrated for samples of SiO2–PMMA prepared either by polymerization of methyl methacrylate in the presence of amorphous SiO2or by mechanically mixing known quantities of the individual and pre-prepared SiO2and PMMA materials. The weight percentages of amorphous SiO2in the nanocomposites as determined by application of the new technique were analogously found to be 29%, a result that was supported by thermogravimetric analysis and helium picnometry measurements.
DuMond analysis of bending in single crystals by Laue diffraction using σ–π polarization geometry
Authors: Serrano Jorge , Ferrero Claudio , Servidori Marco , Härtwig Jürgen , Krisch Michael
Published: October 2008

A DuMond analysis of X-ray diffraction patterns has been carried out in the case of a combined σ–π polarization configuration, obtained using a setup with a double-crystal monochromator in reflection (Bragg) geometry and an analyser in transmission (Laue) geometry. The derived analytical expressions allow the characterization of the bending of the analyser and the quantitative estimation of the curvature radius and its sign from the width of the crystal rocking curves. The theoretical analysis is applied to the case of a thin, accidentally bent, Si crystal.
Technology usage and innovation
Authors: Hamilton Leonora C. , Asundi Ramachandra
Published: October 2008

Purpose

The purpose of this paper is to determine if firms that invest in information technology (IT) and innovate are more profitable than those that do not and to analyze how firms in general and on the island of Puerto Rico, in particular, have found an avenue to compete, grow, and become profitable using technology in production and service, and by extending into the use of electronic commerce. Some recent investigations find that investments in IT do not lead to productivity improvements as measured by accounting standards. Earlier research identified four factors that can lead to such a paradoxical finding.

Design/methodology/approach

The present investigation was undertaken to evaluate, utilizing a case method approach, the extent to which small and medium firms in different industries are prone to this paradoxical condition. Six firms identified in Puerto Rico were contacted to obtain both qualitative and quantitative information from senior officers and CEOs through personal and telephone interviews.

Findings

Utilizing the four factor influence on productivity output of IT investment in each of the present case, the findings show that their effect and subsequent limitations on the broadly defined output measure is minimal. Thus the findings show improved productivity and growth in each of the cases.

Research limitations/implications

A major limitation of the present study is the lack of (proper) quantitative data both at the input stage of IT investment and the output stage of quantitative measures.

Originality/value

The paper is of value in illustrating how small and medium enterprises can successfully adopt and incorporate IT while assuming the necessary investment costs, reaping the benefits of productivity, profitability, and growth within a reasonable span of time.
Multi‐objective harmonious colony‐decision algorithm for more efficiently evaluating assembly sequences
Authors: Zhang Kai‐Fu , Cheng Hui , Li Yuan
Published: October 2008

Purpose

Complex products, such as aircrafts and ships, are assembled from many parts and there are many available assembly sequences. Selecting the best from the available assembly sequences is challenging because of many factors, such as assembly performance, assemblability, assembly cost, assembly quality and assembly time. The purpose of this paper is to investigate a new and efficient algorithm aimed at this goal.

Design/methodology/approach

A new and efficient algorithm evaluating assembly sequences based on multi‐objective harmonious colony‐decision method is presented. This algorithm mainly includes three key steps: first, presenting the priority relationship between assembly sequences and the coefficient matrix for these objectives: assembly performance, assemblability, assembly cost, assembly quality, assembly time, and so on by several experts; second, calculating the maximum of harmonious values and harmonious priority value; third, if the maximum of harmonious priority value is not negative, the algorithm ends. Then the priority relationships of assembly sequences are obtained and the optimal assembly sequence can be selected.

Findings

This algorithm can efficiently support several experts to evaluate assembly sequences according to plenty of evaluation objectives and then to output a harmonious and recognized priority relationship of assembly sequences.

Practical implications

The algorithm is applied successfully to evaluate assembly sequences and select the optimal assembly sequence for component of aircraft's wing with fixtures.

Originality/value

This algorithm provides a new method to synthetically evaluate assembly sequences for complex product according to multi‐objectives.
Weeding: facing the fears
Authors: Dubicki Eleonora
Published: October 2008

Purpose

The purpose of this paper is to provide librarians with an approach to weeding, which reduces librarians' fears and concerns of withdrawing books from an academic collection.

Design/methodology/approach

The paper takes the form of a case study.

Findings

The paper outlines specific steps for implementing a weeding project, including developing criteria and procedures, garnering the support of administration, building librarian confidence in performing weeding, and encouraging teaching faculty involvement.

Originality/value

The paper provides insights into the nature of the concerns and fears librarians face in weeding an academic library collection, and offers suggestions on how to build confidence and support for weeding among both librarians and academic faculty.
Indicators for collection evaluation: a new dimensional framework
Authors: Borin Jacqueline , Yi Hua
Published: October 2008

Purpose

Currently there is a need for an updated assessment model that addresses and reflects the ongoing diversity of issues related to collection evaluation in academic libraries. The purpose of this paper is to provide conceptual guidelines and a model to support collection evaluation and assessment in this time of unstable and constantly changing patterns of information.

Design/methodology/approach

The paper provides a literature review of the collection evaluation and assessment. Based on an analytical study of environmental factors and their relationship to, and impact on, the library collection, the authors propose a new model of collection evaluation to address the needs of the current environment.

Findings

The paper identifies environmental factors in collection evaluation, establishes a set of ratios that need to be addressed and finally, provides a set of indicators for collection evaluation and assessment that can be selected from, and adapted to each library's needs.

Research limitations/implications

This paper bridges two different collection evaluation models, collection‐based and user‐based. It identifies that there is not a single appropriate collection evaluation method. It provides a different perspective to a body of literature that is mostly best practice‐based.

Practical implications

With this research a new model is suggested that provides flexibility and adaptability. It offers a multidimensional approach that libraries can use and adapt to their specific situation.

Originality/value

The new model suggested here addresses a current need generated by a changing information environment. It adds a new approach to the body of literature in the area of collection evaluation.
C.S. Lewis: a guide to resources
Authors: Beard Marcie
Published: October 2008

Purpose

Many bibliographies of books about C.S. Lewis' works and life have been compiled in the past, but a bibliography of recent literary criticism addressing Lewis and his work is hard to come by. The purpose of this paper is to provide a bibliography of the best works recently published about C.S. Lewis and his writings.

Design/methodology/approach

Many different sources were used to find current popular works about C.S. Lewis and his writings. The author searched several databases, read several book reviews, and looked through the source itself when available in order to compile an annotated list of current works, which are viewed to be important additions to the literature about C.S. Lewis and his works.

Practical implications

The resulting bibliography is not a complete list of everything written about C.S. Lewis in the past few years. Instead, the intent is to compile a research guide of the sources considered to be the most useful contributions to the works about C.S. Lewis that already exist.

Findings

Included in this research guide is a list of quality biographies and literary criticism found in reference sources; a sample of book‐length resources focusing on Lewis' life, thought, and writings; short descriptions of periodicals that frequently discuss Lewis' work; and examples of popular databases and web resources dedicated to C.S. Lewis.

Originality/value

In addition to being intended for students, faculty, and those of the general public who are interested in reading about or doing research on C.S. Lewis and his works, this guide is designed for librarians who are trying to develop, maintain, or evaluate a collection on the topic.
Guest editorial
Authors: Harridge‐March Sally
Published: October 2008

Purpose

The purpose of this paper is to show how interactive capability enabled by Web 2.0 has increased the potential for organisations to add value to their offerings by allowing customers to interact with the organisation and other customers of that organisation.

Design/methodology/approach

The paper briefly outlines the content of four articles contained within this special issue.

Findings

Technology has, and will continue to have, a great impact on the banking sector. However much financial service organisations want their customers to use technology, they must remember that technology should be there to enhance the service offering. It must be attractive to customers and offer them something of value. Once customers adopt internet banking and all it has to offer, organisations should continue to monitor operations to ensure that they are providing the best possible service to customers.

Originality/value

It is not enough for the organisation to benefit from reduced costs and speedier processes, the technology must be useful and helpful for customers. Customers need to feel reassured that the organisation and the technology are trustworthy, so that they will not expose themselves to risk when using it.
Perceived risk and Chinese consumers' internet banking services adoption
Authors: Lifen Zhao Anita , Hanmer‐Lloyd Stuart , Ward Philippa , Goode Mark M.H.
Published: October 2008

Purpose

The purpose of this paper is to identify risk factors that discourage Chinese consumers from adopting internet banking services (IBS). This market is experiencing fast growth; however, an in‐depth understanding of Chinese consumers within this is lacking. Perceived risk is a key construct in Western consumer decision making, whereas whether this is true in China's IBS market is rarely researched. An exploration of this dynamic market is therefore critical to develop theoretical and practical implications.

Design/methodology/approach

To maximise the comparability with existing Western findings, the current research adopts a quantitative approach to measure Chinese consumers' risk perception. However, as the existing literature provides limited guidelines associated with the current context, exploratory research was conducted to establish a general understanding and to identify additional elements of this particular market. A detailed instrument was developed and examined Chinese consumers' risk perception in depth. Primary data were collected by self‐administered questionnaires containing 504 respondents from southern China. Exploratory factor analysis is employed to identify critical risk factors.

Findings

Results indicate that the concept of perceived risk has merit in explaining Chinese consumers' decisions on whether to use IBS. Results clearly reveal that the significant risk barriers identified are influenced by culture and do not simply follow predominant Western patterns. Suggestions for banks are developed in an attempt to overcome these risk barriers.

Originality/value

The current research adds value to the existing literature in that findings reinforce the need to (re)examine Western theories from a more critical perspective. This also leads to a discussion addressing further areas for open debate and research.
Cross‐autocorrelations among asset classes
Authors: Miller Edward M. , Prather Larry J. , Imtiaz Mazumder M.
Published: October 2008

Purpose

The purpose of this paper is to examine asset class cross‐autocorrelations at the macro‐level by exploring the return associations among mutual fund asset classes. The low transactions costs of trading mutual funds make this extension important since informed traders can potentially use mutual funds to exploit asset class return cross‐autocorrelations that were not exploitable with individual securities.

Design/methodology/approach

The Granger causality tests and correlation results are employed to ascertain whether significant relationships exist among asset classes. Using a time series of 2,739 daily returns for 641 mutual funds comprising 20 asset classes, trading strategies are developed using the initial sample and evaluated out‐of‐sample on a risk‐adjusted basis.

Findings

Both the cross‐autocorrelations and Granger causality tests suggest that most of the domestic equity asset class returns can predict future global and international equity returns. Further, the trading‐rule portfolios provide a greater return per unit of risk (Sharpe and Treynor ratios) thus dominating all buy‐and‐hold portfolios. Risk‐adjusted excess returns (Jensen's α) of the trading rules are positive and statistically significant at the 1 per cent level. The results of trading strategies also reveal that there are no statistically significant return differences between load and no‐load funds.

Research limitations/implications

Redemption fees seem to be standard practice now, except for money market funds and funds specially designed for market timers. Thus, the trading strategy returns of this paper overestimate actual returns. However, investors may still find the proposed trading strategies beneficial because redemptions fees can be avoided if investors get the opportunities to trade in mutual fund supermarkets. The trading strategies may have implications for other international markets where the sizes and styles of the mutual funds' assets are increasing enormously with a few trading restrictions.

Originality/value

A noteworthy and original contribution of this study is the two‐day Granger causality test. This paper documents that the duration of mutual funds' return predictability extends beyond a one‐day horizon. The duration of daily mutual fund return predictability is believed to be unexplored and should be of considerable relevance to practitioners and regulators.
Service failures and complaints in the family travel market: a justice dimension approach
Authors: Park Oun‐Joung , Lehto Xinran , Park Jung‐Kun
Published: October 2008

Purpose

This study attempts to provide insights into three justice dimensions that constitute a negative family travel experience and to examine the differences existing in industry sectors, service failure settings, and compensation types across the dimensions.

Design/methodology/approach

The research dissected service failures in the family travel market based on the three dimensions of the justice theory. Qualitative data were collected and analyzed utilizing a modified procedure of the critical incident technique. Differences in industry sector, complaint setting, and compensation type were investigated through comparisons of service failure themes within the three justice dimensions using correspondence analysis.

Findings

Critical incidents of family travelers were divided into distributional, procedural, and interpersonal justice categories. The distributive justice dimension showed the highest complaint frequency. Significant differences in justice dimensions were found in the industrial sector, complaint settings, and desired compensation types.

Research limitations/implications

The study is based on data collected from only four public domains. For further research, log data could be collected to triangulate the result from public domains and improve the reliability of the research.

Practical implications

The study has merit in pioneering an examination of the distinct dimensions of family travel service failures across all industry sectors. The results of this study will help tourism suppliers to provide total tourism products for family travelers.

Originality/value

The paper serves as the first exploratory research and contributes to methodological advances in the family travel market by combining justice dimension theory, the CIT approach, and more quantitative tools.