bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adolescent mothers: resilience, family health work and health‐promoting practices
Authors: Black Claire , Ford‐Gilboe Marilyn 
Published: October 2004

Aims.  This paper reports a study examining the relationships among mother's resilience, family health promotion (i.e. health work) and mother's health‐promoting lifestyle practices in single‐parent families led by adolescent mothers by testing hypotheses derived from the Developmental Model of Health and Nursing.Background.  Research on families led by adolescent mothers has focussed primarily on negative maternal and child outcomes while ignoring the capacities of these families, including their efforts to promote the health and well‐being of both mothers and children.Methods.  This replication study was conducted with convenience sample of 41 adolescent mothers recruited using a variety of strategies. Mothers were asked to provide verbal responses to items on three study instruments: The Resilience Scale, a measure of mother's resilience, the Health Options Scale, a measure of family health work and the Health Promoting Lifestyle Profile a measure of mother's health promoting lifestyle practices, as well as a demographic questionnaire.Results.  Consistent with the theory, moderate positive relationships were observed between mothers’ resilience and both family health work (r = 0·34, P = 0·01) and mothers’ health‐promoting lifestyle practices (r = 0·42, P < 0·001). As predicted, moderate correlations were also observed between health work and mother's health promoting lifestyle practices (r = 0·62, P < 0·001). With the effects of employment status and professional support held constant, mother's resilience and health work explained 30·2% of the variance in mother's health‐promoting lifestyle practices.Conclusions.  The study validates theoretical relationships among concepts in the developmental model of health and nursing and contributes to better understanding health promotion in families led by adolescent mothers.
Methodological rigour within a qualitative framework
Authors: Tobin Gerard A. , Begley Cecily M. 
Published: October 2004

Aim.  This paper discusses the literature on establishing rigour in research studies. It describes the methodological trinity of reliability, validity and generalization and explores some of the issues relating to establishing rigour in naturalistic inquiry.Background.  Those working within the naturalistic paradigm have questioned the issue of using validity, reliability and generalizability to demonstrate robustness of qualitative research. Triangulation has been used to demonstrate confirmability and completeness and has been one means of ensuring acceptability across paradigms. Emerging criteria such as goodness and trustworthiness can be used to evaluate the robustness of naturalistic inquiry.Discussion.  It is argued that the transference of terms across paradigms is inappropriate; however, if we reject the concepts of validity and reliability, we reject the concept of rigour. Rejection of rigour undermines acceptance of qualitative research as a systematic process that can contribute to the advancement of knowledge. Emerging criteria for demonstrating robustness in qualitative inquiry, such as authenticity, trustworthiness and goodness, need to be considered. Goodness, when not seen as a separate construct but as an integral and embedded component of the research process, should be useful in assuring quality of the entire study. Triangulation is a tried and tested means of offering completeness, particularly in mixed‐method research. When multiple types of triangulation are used appropriately as the ‘triangulation state of mind’, they approach the concept of crystallization, which allows for infinite variety of angles of approach.Conclusion.  Qualitative researchers need to be explicit about how and why they choose specific legitimizing criteria in ensuring the robustness of their inquiries. A shift from a position of fundamentalism to a more pluralistic approach as a means of legitimizing naturalistic inquiry is advocated.
A new measurement of oesophago‐gastric junction competence
Authors: McMahon B. P. , Frøkjær J. B. , Drewes A. M. , Gregersen H. 
Published: October 2004

AbstractKnowledge of the competence of the oesophago‐gastric junction (OGJ) is fundamental to the understanding of gastro‐oesophageal reflux disease (GORD), a disorder with a high incidence among the general population. A catheter with a bag 9.5 cms long mounted towards the distal end was swallowed by three volunteers. Using manometry readings and the point of respiratory inversion as a guide the probe was placed in the OGJ. The bag was distended with saline at a fixed rate volume before and after the administration of butylscopolamine to block cholinergic‐mediated contractile smooth muscle activity. Using impedance planimetry three cross‐sectional areas (CSA) measurements were made between three pairs of electrodes with 4 mm between each electrode on the catheter placed inside the ballon. Using the law of Laplace, CSA and pressure data could be calculated to give wall tension. Tension rose in all volunteers as the radius increased and it was higher towards the proximal end of the OGJ indicating that this measurement can be used to show the distensibility of the OGJ at different degrees of opening. This technique could be useful in identifying changes in the competence of the lower oesophageal sphincter in some patients with GORD.
Mechanism of butyrate‐induced hyperpolarization of cultured rat myenteric neurones
Authors: Hamodeh S. A. , Rehn M. , Haschke G. , Diener M. 
Published: October 2004

AbstractShort‐chain fatty acids produced by the bacterial fermentation of carbohydrates are present in high concentrations within the colonic lumen and have been shown to alter the excitability of enteric neurones. The present study was designed to investigate the mechanisms of butyrate‐induced changes in membrane potential of myenteric neurones. Myenteric neurones from 4–10‐day‐old rats were isolated from the small and large intestine by an enzymatic digestion with collagenase and kept in culture. Membrane potential was measured with the whole‐cell patch‐clamp technique and the intracellular Ca2+ concentration was measured with the fura‐2 method. The short‐chain fatty acid butyrate (10–100 mmol L−1) induced a reversible and concentration‐dependent hyperpolarization of the membrane with a half‐maximal effect at 30 mmol L−1. The hyperpolarization evoked by butyrate (50 mmol L−1) was strongly inhibited by charybdotoxin (10−7 mol L−1), a specific blocker of Ca2+‐dependent K+ channels. The butyrate‐induced hyperpolarization was resistant against blockade of phospholipase C by U‐73122 (10−5 mol L−1), and resistant against inclusion of heparin (6 × 10−6 mol L−1), an inositol‐1,4,5‐trisphosphate receptor antagonist, in the patch‐pipette. In contrast, ruthenium red (3 × 10−5 mol L−1), an inhibitor of ryanodine receptors, significantly reduced both the hyperpolarization of the membrane as well as the increase in the intracellular Ca2+ concentration evoked by butyrate. Even in neurones permeabilized with saponin (10 mg L−1), butyrate was able to stimulate a release of stored intracellular Ca2+ suggesting a direct action of the short‐chain fatty acid at the stores without mediation of a soluble intracellular second messenger.
Mediators of non‐adrenergic non‐cholinergic inhibitory neurotransmission in porcine jejunum
Authors: Matsuda N. M. , Miller S. M. , Sha L. , Farrugia G. , Szurszewski J. H. 
Published: October 2004

AbstractThe purpose of this study was to determine the non‐adrenergic non‐cholinergic inhibitory neurotransmitter in pig jejunum. Intracellular electrical activity was recorded from circular smooth muscle cells. Inhibitory junction potentials (IJPs) evoked by electrical field stimulation were inhibited by tetrodotoxin (1 μmol L−1), ω‐conotoxin GVIA (0.1 μmol L−1) tetrodotoxin, apamin (1 μ mol L−1), 1‐[6‐((17β‐3‐methoxyestra‐1,3,5(10)‐trien‐17‐yl)amino)hexyl]‐1H‐pyrrole‐2,5‐dione (U‐73122; 10 μmol L−1) but not by N ω‐nitro‐l‐arginine (l‐NNA; 100 μ mol L−1), haemoglobin (10 μ mol L−1), 1H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐1‐one (ODQ; 10 μ mol L−1) or 9‐(tetrahydro‐2‐furyl)adenine (SQ‐22536; 10 μmol L−1). S‐nitroso‐N‐acetylpenicillamine (SNAP) hyperpolarized the membrane potential. This was inhibited by ODQ (3 μmol L−1) and charybdotoxin (0.1 μ mol L−1). Adenosine‐5‐triphosphate (ATP; 100 μ mol L−1) and 2‐methylthio ATP (2‐MeS‐ATP; 100 μmol L−1) did not hyperpolarize the membrane potential and 6‐N‐N‐diethyl‐β‐ γ ‐dibromomethylene‐d‐adenosine‐5′‐triphosphate (ARL67156; 100 μ mol L−1) did not modify IJPs. Carbon monoxide (CO; 10%) and tricarbonyl dichlororuthenium dimer ([Ru(CO3Cl2)]2; 100 μ mol L−1) hyperpolarized the membrane potential however zinc, copper and tin protoporphyrin IX (100 μmol L−1) did not alter IJPs. Vasoactive intestinal peptide (VIP) hyperpolarized the membrane potential but 4‐Cl‐d‐Phe6‐Leu17‐VIP (1 μmol L−1) did not modify IJPs. Pituitary adenylate cyclase activating peptide (PACAP)38 (0.5 μ mol L−1) hyperpolarized the membrane potential. This was inhibited by apamin (1 μmol L−1) but not by tetrodotoxin (1 μ mol L−1). Pituitary adenylate cyclase activating peptide6‐38 (1 μ mol L−1) inhibited IJPs. These data suggest that inhibitory neurotransmission in pig jejunum is mediated partly by PACAP.
Quantitative changes in gastric mucosal glycoproteins: effect of cholinergic agonist and vagal nerve stimulation in the rat
Authors: Yusuf S. , Nok A. J. , Ameh D. A. , Adelaiye A. B. , Balogun E. O. 
Published: October 2004

AbstractThe role of the vagus nerve and cholinergic mechanisms in the control of the rat gastric mucin and protein (PROT) release in vivo was investigated. Under urethane anaesthesia (1.25 g kg−1), the rats had their gastric lumen perfused with saline. Mucus secretion was measured as a function of adherent mucus on the mucosa surface and the luminal content of sialic acids (SIA), galactose (GAL), pyruvate and PROT. Electrical stimulation of the vagi significantly increased the levels of mucus (3.23 ± 025 μg g−1 tissue, P < 0.05), free sialic acid (FS) (0.18 ± 0.04 mg mL−1, P < 0.05) and PROT (0.25 ± 0.003 mg mL−1, P < 0.05) when compared with control animals. Bilateral cervical vagotomy had no significant effect on adherent mucus or basal levels of PROT, SIA and GAL (P > 0.05) with respect to the control. In both vagotomized and vagal intact animals, the cholinergic agonist (carbachol, 200 mg kg−1) significantly increased PROT, adherent mucus and FS (P < 0.05) and decreased bound sialic acid (P > 0.05). There were no visible haemorrhagic streaks on the gastric mucosa of vagotomized, vagal intact and carbachol‐treated animals. The results suggest that vagus nerve does not exert a tonic control on gastric glycoprotein secretion in vivo and that cholinergic effect on the mucus secreting cells may be implemented via the intrinsic nerves of the enteric nervous system.
Tandem inverted repeat system for selection of effective transgenic RNAi strains in Chlamydomonas
Authors: Rohr Jennifer , Sarkar Nandita , Balenger Susan , Jeong Byeong‐ryool , Cerutti Heriberto 
Published: October 2004

SummaryRNA interference (RNAi), the double‐stranded RNA (dsRNA) triggered post‐transcriptional gene silencing, is becoming a powerful tool for reverse genetics studies. Stable RNAi, induced by the expression of inverted repeat (IR) transgenes, has been achieved in protozoa, algae, fungi, plants, and metazoans. However, the level of gene silencing is often quite variable, depending on the type of construct, transgene copy number, site of integration, and target gene. This is a hindrance in functional genomics studies, where it is desirable to suppress target genes reliably to analyze unknown phenotypes. Consequently, we explored strategies for direct selection of effective transgenic RNAi lines in Chlamydomonas reinhardtii. We initially attempted to suppress expression of the Rubisco small subunit multigene family by placing an IR, homologous to the conserved coding sequence, in the 3′UTR of a transgene conferring resistance to bleomycin. However, this approach was fairly inefficient at inducing RNAi as many strains displayed defective transgene integration, resulting in partial or complete deletion of the IR, or low levels of dsRNA expression, presumably due to transcriptional silencing of the integrated IR transgenes. To overcome these problems we designed a system consisting of tandem IR transgenes that consistently triggered co‐silencing of a gene with a selectable RNAi‐induced phenotype (encoding tryptophan synthase β subunit) and another gene of interest (encoding either Ku80, an RNA‐binding protein, or a thioredoxin isoform). We anticipate that this approach will be useful for generating stable hypomorphic epi‐mutants in high‐throughput phenotypic screens.
Stress hormone‐independent activation and nuclear translocation of mitogen‐activated protein kinases in Arabidopsis thaliana during ozone exposure
Authors: Ahlfors Reetta , Macioszek Violetta , Rudd Jason , Brosché Mikael , Schlichting Rita , Scheel Dierk , Kangasjärvi Jaakko 
Published: October 2004

SummaryChanging environmental conditions, atmospheric pollutants and resistance reactions to pathogens cause production of reactive oxygen species (ROS) in plants. ROS in turn trigger the activation of signaling cascades such as the mitogen‐activated protein kinase (MAPK) cascade and accumulation of plant hormones, jasmonic acid, salicylic acid (SA), and ethylene (ET). We have used ozone (O3) to generate ROS in the apoplast of wild‐type Col‐0 and hormonal signaling mutants of Arabidopsis thaliana and show that this treatment caused a transient activation of 43 and 45 kDa MAPKs. These were identified as AtMPK3 and AtMPK6. We also demonstrate that initial AtMPK3 and AtMPK6 activation in response to O3 was not dependent on ET signaling, but that ET is likely to have secondary effects on AtMPK3 and AtMPK6 function, whereas functional SA signaling was needed for full‐level AtMPK3 activation by O3. In addition, we show that AtMPK3, but not AtMPK6, responded to O3 transcriptionally and translationally during O3 exposure. Finally, we show in planta that activated AtMPK3 and AtMPK6 are translocated to the nucleus during the early stages of O3 treatment. The use of O3 to induce apoplastic ROS formation offers a non‐invasive in planta system amenable to reverse genetics that can be used for the study of stress‐responsive MAPK signaling in plants.
Mycobacterium goodiiinfection in a dog with concurrent hyperadrenocorticism
Authors: BRYDEN SHARON L. , BURROWS AMANDA K. , O'HARA AMANDA J. 
Published: October 2004

Abstract A 9‐year‐old Boston terrier was diagnosed with multifocal, nodular panniculitis caused by an organism belonging to theMycobacterium smegmatisgroup by histological evaluation and bacteriological identification. The mycobacterial species was identified by direct gene sequence analysis and confirmed to beMycobacterium goodii.Treatment using doxycycline and ciprofloxacin was successfully implemented for the mycobacterial panniculitis over a period of 9 months. Concurrent pituitary‐dependent hyperadrenocorticism (Cushing's disease) was also identified using routine diagnostic methods and mitotane therapy was implemented. There was follow‐up for 14 months after cessation of antimicrobial therapy with no recurrence of mycobacterial infection. Although cutaneous infections are frequently recognized as complications of canine pituitary‐dependent hyperadrenocorticism, concurrent mycobacterial panniculitis due to any rapidly growing mycobacterium has not previously been reported. This is the first confirmed case of mycobacterial panniculitis due toM. goodiiinfection in a dog and also the first of any rapidly growing mycobacterial infection in a dog with concurrent endogenous Cushing's disease.
A herd level analysis of aCorynebacterium pseudotuberculosisoutbreak in a dairy cattle herd
Authors: YERUHAM ISRAEL , FRIEDMAN SAMUEL , PERL SAMUEL , ELAD DANIEL , BERKOVICH YAIR , KALGARD YORAM 
Published: October 2004

Abstract Corynebacterium pseudotuberculosisinfection in an Israeli dairy cattle herd is described. The disease was characterized by ulcerative granulomatous lesions, which occurred in an epidemic form. Thirty‐two cows and two heifers were affected, the ratio of the number affected to number at risk being 17.5 : 1 and 9.5 : 1, respectively. The culling rate was 50% of the affected animals. Most of the affected animals were cows (91.2%), with one first‐calving cow (2.9%) and two heifers (5.9%) also affected. The infection occurred during the summer to autumn months (August–December), and lasted 118 days. The incubation period is about 2 months. The disease appeared in two clinical forms – cutaneous and mastitic – or as a mixed form.C. pseudotuberculosisorganisms that were isolated from the ulcerative granulomatous lesions and from milk samples failed to reduce nitrate. A decrease in milk production (4%) and an increase in the bulk‐milk somatic cell count from a herd mean of 240 × 103 mL−1to 460 × 103 mL−1were noted during the morbidity period. The organism was isolated from milk samples of eight animals (25%). Clinical, epizootiological and microbiological aspects of the infection are described.
Treatment of canine Alopecia X with trilostane
Authors: CERUNDOLO ROSARIO , LLOYD DAVID H. , PERSECHINO ANGELO , EVANS HELEN , CAUVIN ANDRIA 
Published: October 2004

Abstract Sixteen Pomeranians and eight miniature poodles presenting with clinical signs of alopecia X, elevated blood concentrations of 17‐hydroxyprogesterone post stimulation with adrenocorticotropic hormone and increased urinary cortisol/creatinine ratios were treated with trilostane, a competitive inhibitor of 3β‐hydroxysteroid dehydrogenase. Trilostane was given once or twice daily at a mean dose of 10.85 mg kg−1 day−1. Adrenal function was evaluated with a follow‐up of 28 months in the Pomeranians and 33 months in the miniature poodles. Treatment with trilostane led to complete hair re‐growth in 85% of the Pomeranians and in all of the miniature poodles within 4 to 8 weeks. No adverse events attributed to treatment with trilostane were recognized. The hair re‐growth might have been the result of a down‐regulation of adrenal steroids and/or of the noncompetitive inhibition of the oestrogen receptors at the hair follicle level.
OPEN PROBLEMS IN SOAP BUBBLE GEOMETRY
Authors: SULLIVAN JOHN M. , MORGAN FRANK 
Published: October 2004

The Burlington Mathfest in August 1995 included an AMS Special Session on Soap Bubble Geometry, organized by Frank Morgan. At the end of the session, participants were asked to pose open problems related to bubble geometry. We have collected those problems here, adding a few introductory comments. Participants in the special session included the following: Fred Almgren, Princeton U. Megan Barber, Williams C. Ken Brakke, Susquehanna U. John Cahn, NIST Joel Foisy, Duke U. Christopher French, U.Chicago Scott Greenleaf, SUNY Stony Brook Karsten Groeß-Brauckmann, Bonn Joel Hass, UC Davis Aladár Heppes, Budapest Michael Hutchings, Harvard U. Jenny Kelley, Rutgers U. Andy Kraynik, Sandia Rob Kusner, U.Massachusetts Rafael Lopez, Granada Joe Masters, U.Texas Helen Moore, Bowdoin C. Frank Morgan, Williams C. Ivars Peterson, Science News Robert Phelan, Dublin Joel Shore, McGill U. John Sullivan, U.Minnesota Italo Tamanini, Trento Jean Taylor, Rutgers U. Jennifer Tice, Williams C. Brian Wecht, Williams C. Henry Wente, U.Toledo Brian White, Stanford U.
SYMPLECTIC STRUCTURES AND QUANTUM MECHANICS
Authors: MARMO GIUSEPPE , VILASI GAETANO 
Published: October 2004

Canonical coordinates for the Schrödinger equation are introduced, making more transparent its Hamiltonian structure. It is shown that the Schrödinger equation, considered as a classical field theory, shares with Liouville completely integrable field theories the existence of a recursion operator which allows for the infinitely many conserved functionals pairwise commuting with respect to the corresponding Poisson bracket. The approach may provide a good starting point to get a clear interpretation of Quantum Mechanics in the general setting, provided by Stone–von Neumann theorem, of Symplectic Mechanics. It may give new tools to solve in the general case the inverse problem of quantum mechanics whose solution is given up to now only for one-dimensional systems by the Gel’fand-Levitan-Marchenko formula.
ON THE EVOLUTION OF A MASSLESS SCALAR FIELD IN A SCHWARZSCHILD BACKGROUND: A NEW LOOK AT HAWKING RADIATION AND THE INFORMATION PARADOX
Authors: MELNIKOV KIRILL , WEINSTEIN MARVIN 
Published: October 2004

We exhibit an explicit foliation of Schwarzschild space–time by spacelike hypersurfaces which extend from Schwarzschild r=0 to r=∞. This allows us to compute the values of a massless scalar field for all space–time points which lie in the future of the surface on which we initially quantize the theory. This is to be contrasted with approaches which start at past null infinity and propagate to future null infinity. One of its virtues is that this method allows us to discuss both asymptotic Hawking radiation and what is happening at finite distances from the black hole. In order to explain the techniques we use, we begin by discussing variants of the flat-space moving mirror9 problem. Then we discuss the canonical quantization of the massless scalar field theory and the geometric optics approximation which we use to solve the Heisenberg equations of motion in the black hole background. Using the example of an infalling mirror, an analogue of the moving mirror problem, we show that, although our spacelike slices extend to r=0, we can avoid discussing an initial state which extends through the horizon. Furthermore, we show that in the same way we avoid having to deal with the singularity at r=0 when we first quantize the system. This discussion naturally leads to a suggestion of how to handle the question of what is happening when the mirror hits the singularity. In the last section of the paper we discuss a discretization of the computation which behaves in the manner we suggest and yet exhibits Hawking radiation.5 This formulation of the problem allows us to discuss all the issues in an explicitly unitary setting. The resulting picture raises some interesting questions about the information paradox.
Inter-residue distances derived from fold contact propensities correlate with evolutionary substitution costs
Authors: Williams Gareth , Doherty Patrick 
Published: October 2004

Abstract
Background
The wealth of information on protein structure has led to a variety of statistical analyses of the role played by individual amino acid types in the protein fold. In particular, the contact propensities between the various amino acids can be converted into folding energies that have proved useful in structure prediction. The present study addresses the relationship of protein folding propensities to the evolutionary relationship between residues.

Results
The contact preferences of residue types observed in a representative sample of protein structures are converted into a residue similarity matrix or inter-residue distance matrix. Remarkably, these distances correlate excellently with evolutionary substitution costs. Residue vectors are derived from the distance matrix. The residue vectors give a concrete picture of the grouping of residues into families sharing properties crucial for protein folding.

Conclusions
Inter-residue distances have proved useful in showing the explicit relationship between contact preferences and evolutionary substitution rates. It is proposed that the distance matrix derived from structural analysis may be useful in aligning proteins where remote homologs share structural features. Residue vectors derived from the distance matrix illustrate the spatial arrangement of residues and point to ways in which they can be grouped.