bluuebunny/crossref_metadata_2025 huggingface dataset:
Just What the Doctor Ordered. Review of the Evidence of the Impact of Computerized Physician Order Entry System on Medication Errors
Authors: Shamliyan Tatyana A. , Duval Sue , Du Jing , Kane Robert L.
Published: June 2007

Objective. To examine the association between computerization of physician orders and prescribing medication errors.

Data Sources. Studies published in English language were identified through MEDLINE (1990 through December 2005), Cochrane Central Register of Controlled Trials, and bibliographies of retrieved articles. Of 252 identified in the search, 12 (4.8 percent) original investigations that compared rates of prescribing medication errors with handwritten and computerized physician orders were included.

Data Collection. Information on study design, participant characteristics, clinical settings, and outcomes rates were abstracted independently by two investigators using a standardized protocol.

Principal Findings. Compared with handwritten orders, 80 percent of studies (8/10 studies) reported a significant reduction in total prescribing errors, 43 percent in dosing errors (3/7 studies), and 37.5 percent in adverse drug events (3/8 studies). The use of computerized orders was associated with a 66 percent reduction in total prescribing errors in adults (odds ratio [OR]=0.34; 95 percent confidence interval [CI] 0.22–0.52) and a positive tendency in children (p for interaction=.028). The benefit of computerized orders was larger when the rate of errors was more than 12 percent with handwritten orders (p for interaction=.022). Significant heterogeneity in the results compromised pooled relative risks. One randomized controlled intervention demonstrated the greatest benefits of computerized orders on total prescribing errors (OR=0.02, 95 percent CI 0.01–0.02) and dosing errors (OR=0.28; 95 percent CI 0.15–0.52) with 775 avoided prescribing errors (95 percent CI 752–811) per 1,000 orders in a pediatric hospital.

Conclusions. Computerization of physicians' orders shows great promise. It will be more effective when linked to other computerized systems to detect and prevent prescribing errors.
IdentifiableHelicobacter pyloriStrains or Factors Important in the Development of Duodenal Ulcer Disease
Authors: Figura Natale
Published: June 2007

Background.

Helicobacter pyloriis a primary pathogen as its presence in the stomach almost always is associated with a strong mucosal and systemic immune response. Putative virulence factors ofH. pyloriare numerous. In this article, we evaluate whether currently available evidence supports the existence of factors important in the development of duodenal ulcer disease.

Methods.

The evaluation is conducted by a review of the literature onH. pyloritoxins and virulence factors.

Results.

Most putativeH. pylorivirulence factors are present in all isolates examined, though some are present only in, or are expressed more intensively by, determined strains. Urease is the main virulence determinant ofH. pylori. It generates ammonia from the gastric urea, which in turn injures the gastric mucosa either directly by forming ammonium hydroxide or indirectly by stimulating polymorphonuclear leukocytes and inhibiting cell proliferation. Other enzymes (e.g., mucinase, phospholipases, alcohol dehydrogenase, neuraminidase) could promote tissue erosion and ulceration by destroying the integrity of mucus, by inducing lipid peroxidation, and the like.

H. pyloristrains that express the vacuolating toxinvacA and the associated proteincagA are calledtype Iand are considered to be endowed with increased ulcerogenic and inflammatory potential. Exploration of the structure of thevacA gene has shown that the degree of toxicity is regulated at the molecular level. Type IH. pyloristrains carry a 40‐kb genomic fragment calledcagthat is absent from type II strains (vacA‐ andcagA‐negative).cagis considered a pathogenicity island because it contains numerous genes that are highly homologous to virulence genes of classic bacterial pathogens and because it has been suggested that it is acquired through recombination events.CagAis part of the pathogenicity island.CagA‐positive strains are more likely to be isolated from patients with duodenal ulcer and other severe digestive pathological processes.

Conclusions.

The use of simple serological tests to identify patients infected with type IH. pyloristrains could help to calculate the risk of development of severe gastroduodenal diseases and, possibly, to prevent such severe diseases.
Clinical Relevance of Culture: Why, How, and When
Authors: Holton John
Published: June 2007

Background.

Culture for Helicobacter pylori is undertaken for research and industrial and diagnostic purposes, including antibiotic sensitivity testing of the isolate. The objective of this review is to evaluate the clinical relevance of culture for H. pylori.

Methods.

The clinical relevance of culture for H. pylori is explored by a critical review of the literature.

Results.

Primary isolation of the organism from specimens has direct clinical relevance in terms both of detecting colonization and of determining the antibiotic sensitivity of the isolate, which information is used for patient management and for local, national, or international prevalence rates and trends. It is suggested that when endoscopy is undertaken as part of a management algorithm, a biopsy should always be obtained for culture and sensitivity testing. H. pylori can be cultured from specimens on a variety of selective media, which are selected on the basis of the growth requirement of the organism. Standardization of culture media, culturing methods, and interpretive values for sensitivity testing of isolated strains is lacking. Culture of H. pylori on an industrial scale requires fermenter technology and media that maximize the production of bacterial products that can be easily purified and used as diagnostic or therapeutic agents.

Conclusions.

Culture of laboratory strains of H. pylori for investigation of the organism’s metabolism and virulence factors has only indirect clinical relevance but has led to the identification of targets for therapeutic intervention.
Perturbations in Gastric Physiology inHelicobacter pyloriDuodenal Ulcer: Are They All Epiphenomena?
Authors: Graham David Y. , Dore Maria Pina
Published: June 2007

Background.

The Holy Grail of physiological studies in acid secretion has been to identify a specific abnormality in gastroduodenal physiology responsible for the development of duodenal ulcer disease.

Methods.

We review the available data relating duodenal ulcer andHelicobacter pyloriinfection to perturbations in gastric physiology, especially acid secretion.

Results.

It is known now that elevated serum pepsinogen levels, reduced inhibition of acid secretion with antral acidification or distention, exaggerated gastrin response to meals or infusion of bombesin or gastric‐releasing peptide, exaggerated acid output in response to gastric‐releasing peptide, and abnormalities in duodenal bicarbonate secretion in response to instillation of acid are reversible epiphenomena related to theH. pyloriinfection and are not in themselves responsible for duodenal ulcer disease.H. pyloriis inhibited by bile, yet can thrive in the duodenal bulb of duodenal ulcer patients. Glycine‐conjugated bile acids are precipitated by acid; thus, any mechanism that would increase the duodenal acid load may remove the inhibitory bile and allow unrestrained growth ofH. pylori.

Conclusion.

These data and speculations offer one possible explanation for why duodenal ulcer occurs in only some people—those with high acid secretion—and suggest that the combination of high duodenal acid load andH. pyloriinfection is sufficient to result in duodenal ulcer disease.
The Association Between Helicobacter pylori Infection and Ischemic Heart Disease: Facts or Fancy?
Authors: Parente Fabrizio , Porro Gabriele Bianchi
Published: June 2007

Background.

Helicobacter pylori infection has been associated recently with an increased risk of developing ischemic heart disease.

Methods.

We critically reviewed the literature on the association between Helicobacter and ischemic heart disease.

Results.

It has been suggested that a persistent low‐grade inflammatory response resulting from chronic gastritis caused by H. pylori may increase the concentration of certain coagulation factors, such as fibrinogen, which are predictors of ischemic heart disease. After the appearance of the first studies indicating a moderately strong association, other researchers have investigated the potential association between these two conditions, yielding conflicting results. It must be emphasized that a relationship between fibrinogen or other hemostatic factors and H. pylori infection has been demonstrated only in cross‐sectional studies, many of which included ischemic heart disease patients.

Conclusion.

The present evidence supporting the association between H. pylori infection and ischemic heart disease is based on cross‐sectional surveys, in which it is difficult to separate cause and effect. The high prevalence in the population of both H. pylori and ischemic heart disease makes it very difficult to establish a causal association. Prospective or interventional studies eventually might help to clarify the question.
Coronary Artery Fistula: Single‐Center Experience Spanning 17 Years
Authors: ABDELMONEIM SAHAR S. , MOOKADAM FAROUK , MOUSTAFA SHERIF , ZEHR KENTON J. , MOOKADAM MARTINA , MAALOUF JOSEPH F. , HOLMES DAVID R.
Published: June 2007

Background:

Coronary artery fistula (CAF) is an uncommon form of congenital heart disease. It is often diagnosed incidentally during angiograms. We have reported on clinical characteristics, diagnosis, and management of CAF.

Methods:

Retrospective review of a tertiary referral institution's database identified 30 patients with CAF between 1987 and 2004. Mean follow‐up was 31.61 ± 48.03 months.

Results:

Mean age was 60 ± 12.7 years. Most common site of CAF origin was the left anterior descending artery (LAD) (14, 46.7%). The most common site of drainage was the main pulmonary artery (15, 50%). Therapeutic strategies were based on symptoms and shunt size. Conservative management was the option in 17 patients (56.7%) with small shunts and mild or no symptoms. Patients with moderate/severe symptoms and/or large shunts were treated with either percutaneous embolization (6, 20%) or surgical ligation (7, 23.3%). Four patients (13.3%) died during follow‐up. No deaths were reported in the embolization group, two patients died of cancer in the conservative management group, and two patients died in the surgical group due to cardiac tamponade and cancer, respectively.

Conclusions:

Origin of CAF was predominantly from the left system. Clinical presentations were variable depending on type, size of fistula, and the presence of other cardiac conditions. Management of CAF is still controversial and treatment of adult asymptomatic patients with nonsignificant shunting is still a matter of debate. Newer imaging modalities may enhance noninvasive diagnosis. A national registry is necessary for further insights into optimal treatment for large fistulae and the natural history of smaller fistulae.
Clinical Follow‐Up of Paclitaxel‐Eluting (TAXUS™) Stents for the Treatment of Saphenous Vein Graft Disease
Authors: RUCHIN P.E. , FADDY S.C. , MULLER D.W.M. , BARON D.W. , ROY P.R. , WILSON S.H.
Published: June 2007

Background:Randomized trials in selected patient populations have demonstrated dramatic reductions in the incidence of in‐stent restenosis (ISR) following implantation of paclitaxel‐eluting (PE) coronary stents compared with bare metal stents in native coronary disease. The clinical outcome following implantation of PE stents for saphenous vein graft (SVG) stenosis is largely unknown.

Aim:To assess the safety and efficacy of PE coronary stents for the treatment of SVG stenosis in an unselected population.

Methods:All patients who received PE stents for the treatment of SVG disease from May 1, 2003, to May 1, 2005, were entered into a prospectively collected database. Fifty‐five patients were identified with 69 lesions. In‐hospital and late major adverse cardiac events (MACE) including death, myocardial infarction (MI), and target lesion revascularization (TLR) were recorded as well as the rate of target vessel revascularization (TVR).

Results:Mean follow‐up was 13 months with 54 of the 55 patients contacted. The number of stents implanted was 1.12 ± 0.37 per lesion and 1.38 ± 0.59 per patient. Clinically significant procedural MACE was 0%. The late MACE rate was 9% with a 2% clinically driven TLR, a 4% coronary artery bypass graft (CABG), and a 4% TVR rate. There were four deaths, two cardiac and two noncardiac.

Conclusion:PE stents appear safe and effective in the treatment of SVG disease at a mean follow‐up time of 13 months. Randomized studies are needed to further delineate the optimal management of this high‐risk group.
Ezra Pound's Cantos: A Compact History of Twentieth‐Century Authorship, Publishing and Editing
Authors: Byron Mark
Published: June 2007

This paper forms part of a Literature Compass cluster on Modern Book History. The full cluster is made up of the following articles:

‘Between Then and Now: Modern Book History’, Kate Longworth, Literature Compass 4 (2007), 10.1111/j.1741‐4113.2007.00474.x.

‘Ezra Pound's Cantos: A Compact History of Twentieth‐Century Authorship, Publishing and Editing’, Mark Byron, Literature Compass 4 (2007), 10.1111/j.1741‐4113.2007.00475.x.

‘ “The Making of the Book”: Roy Fisher, the Circle Press and the Poetics of Book Art’, Matthew Sperling, Literature Compass 4 (2007), 10.1111/j.1741‐4113.2007.00476.x.

‘Bakhtinian “Journalization” and the Mid‐Victorian Literary Marketplace’, Dallas Liddle, Literature Compass 4 (2007), 10.1111/j.1741‐4113.2007.00477.x.

‘Manuscript in Print: The Materiality of Alternative Comics’, Emma Tinker, Literature Compass 4 (2007), 10.1111/j.1741‐4113.2007.00478.x.

‘Lost in a World of Books: Reading and Identity in Pre‐War Japan’, Susan C. Townsend, Literature Compass 4 (2007), 10.1111/j.1741‐4113.2007.00479.x.

***

Ezra Pound's modernist epic poem, The Cantos, was composed over almost six decades of the twentieth century. Its publication history – from the earliest instalments in little magazines in the nineteen‐teens to collected and posthumous editions – entails several challenges to traditional notions of literary completion, authorial control, justified (and unjustified) editorial intervention, and collaboration between authors and scholars intent on ‘cleaning‐up’ apparently corrupted texts. Pound's cultural engagements (particularly politics and economics), creative pursuits and personal history inflect some of these aspects of his text's literary and bibliographical career over the last ninety years (for example, his incarceration by the United States Army during the Second World War and the subsequent loss of his status as the legal owner of his written words). In this paper I will indicate some challenges to literary and bibliographical convention arising from Pound's text as well as from his personal circumstances and his relations with his principal editors: T. S. Eliot at Faber and Faber, and James Laughlin at New Directions. I will also address some challenges to editing Pound's text today: the ways in which competing printed versions and ancillary materials might be brought to bear on persistent questions of status and permissible editorial agency; the role of technology in attempts to ‘clean up’ Pound's text; and the way in which editorial theory might assist in reflecting upon the kind(s) of authorial status and editorial mediation at work in this distillation of so much history and cultural production. Pound's epic poem can be seen to challenge the very boundaries of the text and the book in radical ways, both in modernist and in contemporary (including electronic) modes.
Implementation of CDC’s School Health Index in 3 Midwest Middle Schools: Motivation for Change
Authors: Sherwood‐Puzzello Catherine M. , Miller Michelle , Lohrmann David , Gregory Patricia
Published: June 2007

Background:  The Centers for Disease Control and Prevention’s School Health Index (SHI), a guide for completing a coordinated school‐based program needs assessment relative to healthy eating, physical activity, a tobacco‐free lifestyle, and prevention of other health risk behaviors and conditions, was used to assess current programming at 3 midwestern middle schools.

Methods:  Employing somewhat different procedures, data were collected from focus groups comprising school administrators, teachers, parents, community members, and students. Participants responded to SHI module questions and provided comments based on their perceptions. Both quantitative and qualitative data were recorded for each module, after which participants answered 3 planning questions intended to guide prioritization of actions to improve policies and programs based on importance, cost, time, commitment, and feasibility.

Results:  Each school developed recommendations and strategies based on highest priority needs related to community involvement, professional development, health screenings, and health education materials in classrooms.

Conclusions:  The experience of completing the SHI in 3 different schools provided important insights about the data collection process as well as assessment results that have implications for the design and implementation of prevention programs.
Staff‐ and School‐Level Predictors of School Organizational Health: A Multilevel Analysis
Authors: Bevans Katherine , Bradshaw Catherine , Miech Richard , Leaf Philip
Published: June 2007

Background:  An organizationally healthy school environment is associated with favorable student and staff outcomes and thus is often targeted by school improvement initiatives. However, few studies have differentiated staff‐level from school‐level predictors of organizational health. Social disorganization theory suggests that school‐level factors, such as faculty turnover, student mobility, and concentration of student poverty, would be negatively associated with school organizational health, but these relationships may be moderated by staff‐level factors.

Methods:  The present study examined the association among school‐ and staff‐level predictors of staff‐perceived school organizational health (eg, academic emphasis, collegial leadership, and staff affiliation), as measured by the Organizational Health Inventory.

Results:  Multilevel analyses on data from 1395 staff across 37 elementary schools indicated that school membership accounted for between 26% and 35% of the variance in different components of staff‐perceived organizational health. Two‐level hierarchical analyses indicated that both school‐ and staff‐level characteristics are important predictors of organizational health. Furthermore, some school and staff characteristics interacted to predict staff affiliation and collegial leadership.

Conclusions:  Findings suggest that factors at both the school and staff level are important potential targets for school improvement. Administrators aiming to improve relationships among staff members should be cognizant of staff‐level characteristics (race, age, and role in school) associated with less favorable perceptions of the school environment, whereas efforts to enhance student work ethic and discipline should target schools with specific school‐level characteristics (high rates of faculty turnover and student mobility).
Study of Health Outcomes in School Children: Key Challenges and Lessons Learned From The Framingham Schools’ Natural History of Nevi Study
Authors: Geller Alan C. , Oliveria Susan A. , Bishop Marilyn , Buckminster Marcia , Brooks Katie R. , Halpern Allan C.
Published: June 2007

Background:  We describe the planning, recruitment, key challenges, and lessons learned in the development of a study of the evolution of nevi (moles) among children in a school setting.

Methods:  This population‐based study of digital photography and dermoscopy of the child’s back (overview, close‐up, and dermoscopic images) and genetic specimens took place among fifth graders in the Framingham, Massachusetts School System. Schoolchildren and their parents completed baseline surveys on sun protection practices, sunburns, and past ultraviolet exposures, including summer and vacation experiences.

Results:  Prestudy outreach was conducted with children, parents, nurses, administrators, and pediatricians. Of the 691 Framingham families with a fifth grader (aged 10‐11), 443 consented to complete surveys and undergo digital photography and dermoscopy during the school’s routine scoliosis testing. Of the 443 families providing consent, 369 agreed to genetic testing. We identified key factors to consider when implementing school‐based studies: (a) pilot studies to demonstrate feasibility, (b) inclusion of school administration and parents, (c) grassroots approach with multiple contacts, and (d) embedding research studies within preexisting school health services.

Conclusions:  Launching an observational study within the school environment required an academic/school collaboration across numerous disciplines including dermatology, epidemiology, genetics, medical photography, school health, community health education, and most notably, the need for the presence of a full‐time study nurse in the school. A large school system proved to be an excellent resource to conduct this first prospective study on the evolution of moles in US schoolchildren. The key challenges and lessons learned may be applicable to other investigators launching school‐based initiatives.
SEPARATING SOUTHERN BLUE WHALE SUBSPECIES BASED ON LENGTH FREQUENCIES OF SEXUALLY MATURE FEMALES
Authors: Branch T. A. , Abubaker E. M. N. , Mkango S. , Butterworth D. S.
Published: June 2007

Abstract

When sexually mature, Antarctic (true) blue whales are substantially longer than pygmy blue whales. To estimate the proportions of these two subspecies in various regions, Bayesian mixture models were fitted to catch length frequencies of sexually mature females. The extent of rounding to 5‐ft intervals was also estimated. Antarctic blue whales dominated (99.2%) pelagic catches south of 52°S, whereas pygmy blue whales dominated (99.9%) north of 52°S and in 35°–180°E. South of 60°S, only 0.7% (95% credibility interval 0.5%–1.0%) were pygmy blue whales, lower than the 7% upper bound currently assumed. Shore‐based catches from SW Africa and those before 1937 from South Georgia and the South Shetlands were estimated to contain 90%–92% Antarctic blue whales. Actual proportions were probably higher, but these data show evidence of rounding (up to 19% of records), poor length‐estimation methods, and other problems. The mean length of sexually mature female Chilean blue whales (77.1 ft, 23.5 m) was intermediate between pygmy (68.9 ft, 21.0 m) and Antarctic blue whales (83.4–86.3 ft, 25.4–26.6 m). A good fit to these data was obtained only by assuming that the Chilean whales are a separate subspecies or distinctive population. This finding is also consistent with their discrete distribution, and genetic and call type differences, compared to Antarctic and pygmy blue whales.
ESTIMATING POPULATION SIZE IN ASYNCHRONOUS AGGREGATIONS: A BAYESIAN APPROACH AND TEST WITH ELEPHANT SEAL CENSUSES
Authors: Condit Richard , Le Boeuf Burney J. , Morris Patricia A. , Sylvan Marshall
Published: June 2007

Abstract

Many organisms reproduce in temporary aggregations where estimates of colony size can be made by direct counts. When individuals are not synchronous, however, early breeders depart before the last arrive, so counts underestimate the total breeding population. We present a model describing a colony's census as a function of arrival, breeding tenure, and the correlation between them, and we use it to illustrate how variance in arrival and tenure affect the census. Counts of breeding female northern elephant seals (Mirounga angustirostris) from 1975 to 2007 were used to test the model. Four of the model's parameters—population size, mean and variance of arrival date, and the correlation between arrival date and breeding tenure—could be estimated from census data using a Bayesian approach; prior estimates of two other parameters—mean tenure and its variance—had to be used to avoid overparameterization. The model's predictions fit observed censuses well and produced reliable estimates of population size and arrival behavior, showing that the maximum census was 8%–16% below the total number of breeding females. This method could be used for estimating abundance in any asynchronous aggregation, given independent information on one of the defining distributions: arrival, tenure, or departure.
Places of Work, Scales of Organising: A Review of Labour Geography
Authors: Lier David Christoffer
Published: June 2007

Labour has for a long time been an important concept in economic geography, but more often as a cost that influences investment decisions than as a social force in its own right. Recently, however, some geographers have begun putting the politics of labour at the forefront of the analysis. Labour geography can be understood as a discernible strand of research which, throughout the last decade or so, has begun to emerge from a wider Anglo‐American Marxist‐inspired geography tradition. In this article, I will critically review this emerging literature, which represents a fresh approach to the recent changes in the world of work and to the close relationships between workers, firms, the state and the wider community. Particularly interesting – from a geographical point of view – are the strategies of organised labour in creating new scales of organising, and in rethinking old ones.
Light Absorption Properties of the Rabbit Cornea Repeatedly Irradiated with UVB Rays
Authors: Čejka Čestmír , Pláteník Jan , Guryca Vilém , Širc Jakub , Michálek Jiří , Brůnová Blanka , Čejková Jitka
Published: June 2007

Under normal conditions, the cornea absorbs the majority of UVB (ultraviolet B, 280–320 nm) rays, which is very important for the protection of the inner eye against their damaging effect. Our previous studies have shown that repeated irradiation of the rabbit cornea with UVB rays for 5 days (daily dose of 1.01 J cm−2) caused photokeratitis accompanied by swelling (hydration) of the corneal stroma, thinning of the corneal epithelium and decrease in antioxidants. The purpose of this study was to examine the light absorption properties of such damaged rabbit cornea. Results of both spectrophotometry of the whole corneal buttons and corneal tissue dissolved in sodium hydroxide show that because of above mentioned disturbances, UVB‐irradiated cornea absorbs more light throughout the whole measurable UV–VIS spectral range than the normal cornea. Increased corneal thickness (result of hydration), changes of corneal transparency (the cornea becomes grayish) and some increase in protein content all contribute to the increased light absorption of UVB irradiated corneas. We suggest that the UVB‐irradiated cornea, although damaged and nearly without antioxidants, might actually through its higher UV absorbance protect the inner eye against further damage from UVB rays.
Photodynamic Therapy Resistant Human Colon Carcinoma HT29 Cells Show Cross‐Resistance to UVA but not UVC Light
Authors: Zacal Natalie , Rainbow Andrew J.
Published: June 2007

The isolation of photodynamic therapy (PDT)‐resistant HT29 human colon adenocarcinoma cells has been reported previously. These PDT‐resistant variants show increased expression of the Hsp27 and BNip3 proteins and a decreased expression of mutant p53 protein compared with parental HT29 cells. Because mutant p53 and increased expression of Hsp27 have been associated with resistance to various chemotherapeutic agents, whereas BNip3 is a potent inducer of apoptosis, we were interested in determining whether these PDT‐resistant cells were cross‐resistant to other cytotoxic agents. In the present report, we examined the colony survival of the PDT‐resistant HT29 variants and several other clonal variants of HT29 cells to ultraviolet light (UV) treatment. The HT29 PDT‐resistant variants showed cross‐resistance to long‐wavelength UVA (320–400 nm) but not to short‐wavelength UVC (200–280 nm) light. Cell sensitivity to UVA or UVC was then correlated with Hsp27, BNip3 and mutant p53 protein levels in the PDT‐resistant variants as well as in several clonal variants of HT29 cells that express different levels of Hsp27, BNip3 and mutant p53. We show that increased expression of Hsp27 and BNip3 and decreased expression of mutant p53 correlated with increased resistance to UVA. In contrast, increased expression of Hsp27 and BNip3 correlated with increased sensitivity to UVC, whereas increased expression of mutant p53 showed no significant correlation with sensitivity to UVC. These results suggest that the PDT‐resistant HT29 cell variants are differentially sensitized to UVA compared with UVC due, in part at least, through the altered expression levels of BNip3, Hsp27 and mutant p53.
DNA Cleavage Induced by Photoexcited Antimalarial Drugs: A Photophysical and Photobiological Study
Authors: Aloisi Gian Gaetano , Amelia Matteo , Barbafina Arianna , Latterini Loredana , Elisei Fausto , Dall’Acqua Francesco , Vedaldi Daniela , Faccio Anita , Viola Giampietro
Published: June 2007

The interactions and the photosensitizing activity of three antimalarial drugs quinine (Q), mefloquine (MQ) and quinacrine (QC) toward DNA was studied. Evidences obtained by absorption and emission spectroscopy and by linear dichroism measurements indicate that these derivatives bind the macromolecule with a high affinity (binding constants Ka ∼ 105 M−1). The absorption characteristics of the drugs changed markedly by addition of DNA and their fluorescence was quenched with rate constants higher than that of diffusion. The geometry of binding involves predominantly the intercalation into the double helix. The DNA photocleavage properties of antimalarials was investigated using plasmid DNA as a model, at different [drug]/[DNA] ratios. The results indicate that mainly MQ and Q are able to induce significant photodamage to DNA. In particular the marked effect of the former drug is evidenced after treatment of photosensitized DNA by two base excision repair enzymes, formamydo‐pyrimidine glycosilase (Fpg) and Endonuclease III (Endo III). From a mechanistic point of view, experiments carried out in different experimental conditions indicate that these drugs photoinduce DNA damage through singlet oxygen and/or radical cation production. These findings are further supported by the determination of two photoproducts of 2′‐deoxyguanosine, which are diagnostic for Type I and Type II pathways, namely 2,2‐diamino(2‐deoxy‐β‐d‐erythro‐pentofuranosyl)‐4‐amino‐5(2H)‐oxazolone and (R,S)4‐hydroxy‐8‐oxo‐4,8‐dihydro‐2′‐deoxyguanosine (4‐OH‐8‐oxo‐dGuo). Laser flash photolysis experiments carried out in the presence of DNA indicates that the excitation produces mainly the triplet state for Q and the triplet and radical cation for QC. Moreover the singlet and triplet states and radical cations of the drugs are quenched by 2′‐deoxyguanosine monophosphate. The absorbances of these transients decrease with increasing DNA concentration.
Glycolysis inhibitors negatively bias blood glucose measurements: potential impact on the reported prevalence of diabetes mellitus
Authors: Waring W S , Evans L E , Kirkpatrick C T
Published: June 2007

Background:Blood glucose concentrations are essential in defining diabetes mellitus. Recent guidelines advocate either of two discrete methods for sample collection and processing. One of these involves addition of glycolysis inhibitors, such as sodium fluoride–potassium oxalate (NaF–KOx) to sample collection tubes, whereas the other requires immediate refrigeration and sample separation.

Aims:To examine whether the choice of the preanalytical process has any impact on subsequent glucose determinations.

Methods:62 healthy men participated in the study during screening for diabetes. Paired venous blood samples were collected in a serum-gel tube and a tube containing NaF–KOx (both Sarstedt, Leicester, UK). Serum was promptly separated from gel tube samples and refrigerated, whereas NaF–KOx samples were not separated until immediately before analysis. Glucose concentrations were determined using an Olympus AU 2700 analyser incorporating an automated hexokinase method.

Results:Mean (95% CI) glucose concentration in serum-gel tube samples was 5.2 mmol/l (5.0 to 5.4 mmol/l), whereas the concentration in tubes containing NaF–KOx was 4.9 mmol/l (4.8 to 5.1 mmol/l). A negative bias of 0.23 mmol/l (0.16 to 0.30 mmol/l) and relative negative bias of 4.7 % (3.2% to 6.3%) were observed for samples collected in NaF–KOx tubes, consistent with the combined effects of glycolysis and dilution.

Conclusions:Bias associated with the use of NaF–KOx tubes may have a significant impact on the prevalence of fasting hyperglycaemia, according to current diagnostic criteria. The small but significant difference between preanalytical processes should be considered when screening for the presence of diabetes mellitus.
THE VISCOUS MODEL OF QUANTUM HYDRODYNAMICS IN SEVERAL DIMENSIONS
Authors: CHEN LI , DREHER MICHAEL
Published: June 2007

We investigate the viscous model of quantum hydrodynamics in one and higher space dimensions. Exploiting the entropy dissipation method, we prove the exponential decay to the thermal equilibrium state in one, two, and three dimensions, provided that the domain is a box. Further, we show the local in time existence of a solution in the one-dimensional case; and in the case of higher dimensions under the assumption of periodic boundary conditions. Finally, we prove the global existence in a one-dimensional setting under additional assumptions.
EXISTENCE, UNIQUENESS AND APPROXIMATION OF A DOUBLY-DEGENERATE NONLINEAR PARABOLIC SYSTEM MODELLING BACTERIAL EVOLUTION
Authors: BARRETT JOHN W. , DECKELNICK KLAUS
Published: June 2007

We consider the following nonlinear parabolic system [Formula: see text] subject to no flux boundary conditions, and non-negative initial data u0and v0on u and v. Here we assume that c > 0, θ ≥ 0 and that [Formula: see text] is increasing with f(0) = 0. The system is possibly doubly-degenerate in that [Formula: see text] is only non-negative, and ψ ∈ C1([0,∞)) ∩ C2((0,∞)) is convex, strictly increasing with ψ(0) = 0 and possibly ψ'(0) = 0. The above models the spatiotemporal evolution of a bacterium species on a thin film of nutrient, where u is the nutrient concentration and v is the bacterial cell density. Under some further mild technical assumptions on b and ψ, we prove the existence and uniqueness of a weak solution to the above system. Moreover, we prove error bounds for a fully practical finite element approximation of this system. All of our results apply to the choices b(r) ≔ rqand ψ(r) ≔ rpwith q ≥ 2 and p ≥ 1, for example.
A PLASMA EXPANSION MODEL BASED ON THE FULL EULER–POISSON SYSTEM
Authors: CRISPEL P. , DEGOND P. , VIGNAL M. H.
Published: June 2007

In this paper, we consider a quasi-neutral plasma expanding in the vacuum gap separating two electrodes. During the expansion, some particles are emitted from the plasma-vacuum interface and form a beam in the vacuum. Starting from the two-fluid full Euler–Poisson model, we derive an asymptotic model. This asymptotic model consists of a quasi-neutral model in the plasma region, a Child–Langmuir law in the beam region and connection relations at the plasma-beam interface. For this model, we propose a numerical scheme which accounts for the motion of the plasma-beam interface and is much more efficient than the resolution of the original two-fluid Euler–Poisson problem. We demonstrate the efficiency of the model by means of numerical simulations for two different one-dimensional test cases.
SECONDHAND SMOKE REDUCES CORTICAL BONE FRACTURE TOUGHNESS
Authors: PORTER D. S. , FRANCE J. C. , KISH V. L. , CLOVIS N. B. , SMITH E. S. , NORMAN TIMOTHY L.
Published: June 2007

Cigarette smoking is commonly recognized for its carcinogenic effects. Clinical studies have found that smoking also increases the risk of stress fracture and decreases the fusion rate during bone healing. Nicotine is the most well-known chemical found in cigarettes, and has been implicated in the debilitating effects of smoking. This study investigated the effect of nicotine and secondhand smoke on the fracture resistance of cortical bone taken from rabbit tibias. Nicotine was delivered via a transdermal nicotine patch and a smoking chamber. There were three groups in this study: the control group, a 5-week nicotine patch group, and a 5-week smoking group. The results of this study showed that rabbits exposed to secondhand smoke for 5 weeks had a significant reduction in cortical bone fracture toughness compared to control rabbits, while the fracture toughness of rabbits exposed to nicotine alone was not significantly different than the fracture toughness of the control group.
BIOMECHANICS OF THE NORMAL AND DISEASED METACARPOPHALANGEAL JOINT: IMPLICATIONS ON THE DESIGN OF JOINT REPLACEMENT IMPLANTS
Authors: PYLIOS T. , SHEPHERD DUNCAN E. T.
Published: June 2007

The metacarpophalangeal (MCP) joint is crucial for hand function, but is frequently affected by arthritis, leading to pain and disability. This paper reviews the biomechanics of the normal and diseased joint in order to help consider the design of improved MCP joint replacement implants. The normal MCP joint enables a large range of motion in flexion/extension and abduction/adduction as well as a few degrees of rotation. A normal joint typically allows 90° flexion, with a grip strength of up to 672 N. The diseased joint has a reduced range of motion (typically 30° flexion) and reduced hand strength compared to the normal joint. Current MCP joint replacement implants generally try to recreate the range of motion of the normal joint; however, many designs are prone to fracture, as they are unable to withstand the conditions of the diseased joint. It may be beneficial for future implant designs to provide just a functional range of motion. Future designs of MCP joint replacement implants need to be more durable and last longer. Careful consideration of the diseased joint, rather than the normal joint, may help to better define the requirements for such implants.
GEOMETRIC QUANTIZATION OF HAMILTONIAN ACTIONS OF LIE ALGEBROIDS AND LIE GROUPOIDS
Authors: BOS ROGIER
Published: June 2007

We construct Hermitian representations of Lie algebroids and associated unitary representations of Lie groupoids by a geometric quantization procedure. For this purpose, we introduce a new notion of Hamiltonian Lie algebroid actions. The first step of our procedure consists of the construction of a prequantization line bundle. Next, we discuss a version of Kähler quantization suitable for this setting. We proceed by defining a Marsden–Weinstein quotient for our setting and prove a "quantization commutes with reduction" theorem. We explain how our geometric quantization procedure relates to a possible orbit method for Lie groupoids. Our theory encompasses the geometric quantization of symplectic manifolds, Hamiltonian Lie algebra actions, actions of bundles of Lie groups, and foliations, as well as some general constructions from differential geometry.
THE KERR THEOREM AND MULTI-PARTICLE KERR–SCHILD SOLUTIONS
Authors: BURINSKII ALEXANDER
Published: June 2007

We discuss an extended version of the Kerr theorem which allows one to construct the exact solutions of the Einstein–Maxwell field equations from a holomorphic generating function F of twistor variables. The exact multi-particle Kerr–Schild solutions are obtained from generating function of the form [Formula: see text], where Fi are partial generating functions for the spinning particles i = 1 ⋯ k. Solutions have an unusual multi-sheeted structure. Twistorial structures of the ith and jth particles do not feel each other, forming a type of its internal space. Gravitational and electromagnetic interaction of the particles occurs via the light-like singular twistor lines. As a result, each particle turns out to be "dressed" by singular pp-strings connecting it to other particles. We argue that this solution may have a relation to quantum theory.
SOLUTION TO $\overline{\partial}$-EQUATIONS WITH EXACT SUPPORT ON PSEUDO-CONVEX MANIFOLDS
Authors: ABDELKADER OSAMA , SABER SAYED
Published: June 2007

We obtain a solution to the [Formula: see text]-equation with exact support in a domain Ω with C1-smooth boundary satisfying property B in a complex manifold. This is done for complex-valued forms of type (r,s), s ≥ 1 and for forms of type (r,s), q ≤ s ≤ n - q, with values in a holomorphic vector bundle when the domain Ω is strongly q-convex.
ON BOOSTED SPACE-TIMES WITH COSMOLOGICAL CONSTANT AND THEIR ULTRARELATIVISTIC LIMIT
Authors: ESPOSITO GIAMPIERO , PETTORINO ROBERTO , SCUDELLARO PAOLO
Published: June 2007

The problem of deriving a shock-wave geometry with cosmological constant by boosting a Schwarzschild-de Sitter (or anti-de Sitter) black hole is re-examined. Unlike previous works in the literature, we deal with the exact Schwarzschild-de Sitter (or anti-de Sitter) metric. In this exact calculation, where the metric does not depend linearly on the mass parameter, we find a singularity of distributional nature on a null hypersurface, which corresponds to a shock-wave geometry derived in a fully non-perturbative way. The result agrees with previous calculations, where the metric had been linearized in the mass parameter.
THE SUNDA MEGATHRUST — PAST, PRESENT AND FUTURE
Authors: SIEH KERRY
Published: June 2007

After lying dormant for about a thousand years, sudden slippage of a 1600-km long section of the Sunda megathrust fault caused uplift of the seafloor between Aceh and Myanmar, resulting in a great earthquake and the horrific Indian Ocean tsunami of 2004. Three months later and just to the south, sudden slippage of a 350-km length of the megathrust beneath Simeulue and Nias islands caused another destructive great earthquake and lesser tsunami. Because it takes centuries for tectonic strains to build up again after such big earthquakes, these two events are unlikely to recur within the next hundred years. Farther south, however, offshore West Sumatra and Bengkulu provinces, another great earthquake and tsunami will likely occur within the next few decades. We are trying to characterize that future earthquake and tsunami, to encourage and to focus preparations for and mitigation of the coming disaster. Similar efforts need to be initiated throughout much of south and southeast Asia, if the disastrous effects of future large earthquakes and tsunamis are to be mitigated.
THE SUMATRAN FAULT ZONE — FROM SOURCE TO HAZARD
Authors: NATAWIDJAJA DANNY HILMAN , TRIYOSO WAHYU
Published: June 2007

The substantial portion of the dextral component of the Sumatran oblique convergence is accommodated by the Sumatran fault. This 1900 km-long active strike-slip fault zone runs along the backbone of Sumatra pose seismic and fault hazards to dense population on and around the fault zones. The Sumatran fault is highly segmented, and consists of 20 major geometrically defined segments, which range in length from about 60 to 200 km. These segment lengths influenced seismic source dimensions and have limited the magnitudes of large historical fault ruptures to between Mw6.5 and about 7.7. Slip rates along the fault increase northwestward, from about 5 mm/yr around the Sunda Strait to 27 mm/yr around Toba Lake. These sliprate values provide a quantitative basis for calculation of average expected recurrence periods for large earthquakes on each segment. Deterministic and probabilistic hazard assessments are constructed based on these active fault data.
SEISMIC SHAKING IN SINGAPORE DUE TO PAST SUMATRAN EARTHQUAKES
Authors: PAN TSO-CHIEN , MEGAWATI KUSNOWIDJAJA , LIM CHEE LEONG
Published: June 2007

In 1996, the Meteorological Service of Singapore (MSS) installed a network of seven seismic stations. Nanyang Technological University (NTU) has also installed two additional seismic stations. Together, the nine stations form a network called the Singapore Array for Earthquake Response (SAFER). One of the stations installed by NTU consists of two sets of four accelerometers installed in a 66-storey commercial building for the study of building response to far-field earthquakes.

This paper summarizes the research work that has been developed from the network of sensors. During the operation of the SAFER array, far-field earthquake ground motions have been recorded for many Sumatra earthquake events. From this, local site characteristics have been studied and hazard maps showing the amplified peak ground acceleration of the earthquake has been developed for the local sites. A case study for the hazard map due to the Bengkulu earthquake (Mw= 7.7) of June 4, 2000, is shown. Based on numerical studies of typical building structures in Singapore, an additional response map showing spatial variation of approximate base shear of buildings has been developed for Singapore. A case study of the response map due to the Bengkulu earthquake (Mw= 7.7) of June 4, 2000, is also shown.

For future seismic hazard assessments of Singapore, a set of attenuation relationships that can reasonably predict the ground-motion intensity in Singapore generated by potential seismic sources have to be established. These attenuation relationships have to be developed using synthetic seismograms because the ground motion data that have been recorded within the last 10 years is not sufficient to develop them empirically. However, the available ground motions play a critical role in validating the synthetic attenuation relationships.

The ultimate objective of this continuing research work is to incorporate a real-time monitoring system with the ground motion prediction models into hazard and response maps for scenario earthquakes. Such an integrated system when developed may assist in the planning of emergency responses to various earthquake scenarios.
Tissue-dependent loss of phosphofructokinase-M in mice with interrupted activity of the distal promoter: impairment in insulin secretion
Authors: Richard Ann-Marie T. , Webb Dominic-Luc , Goodman Jessie M. , Schultz Vera , Flanagan John N. , Getty-Kaushik Lisa , Deeney Jude T. , Yaney Gordon C. , Dunaway George A. , Berggren Per-Olof , Tornheim Keith
Published: June 2007

Phosphofructokinase is a key enzyme of glycolysis that exists as homo- and heterotetramers of three subunit isoforms: muscle, liver, and C type. Mice with a disrupting tag inserted near the distal promoter of the phosphofructokinase-M gene showed tissue-dependent differences in loss of that isoform: 99% in brain and 95–98% in islets, but only 50–75% in skeletal muscle and little if any loss in heart. This correlated with the continued presence of proximal transcripts specifically in muscle tissues. These data strongly support the proposed two-promoter system of the gene, with ubiquitous use of the distal promoter and additional use of the proximal promoter selectively in muscle. Interestingly, the mice were glucose intolerant and had somewhat elevated fasting and fed blood glucose levels; however, they did not have an abnormal insulin tolerance test, consistent with the less pronounced loss of phosphofructokinase-M in muscle. Isolated perifused islets showed about 50% decreased glucose-stimulated insulin secretion and reduced amplitude and regularity of secretory oscillations. Oscillations in cytoplasmic free Ca2+and the rise in the ATP/ADP ratio appeared normal. Secretory oscillations still occurred in the presence of diazoxide and high KCl, indicating an oscillation mechanism not requiring dynamic Ca2+changes. The results suggest the importance of phosphofructokinase-M for insulin secretion, although glucokinase is the overall rate-limiting glucose sensor. Whether the Ca2+oscillations and residual insulin oscillations in this mouse model are due to the residual 2–5% phosphofructokinase-M or to other phosphofructokinase isoforms present in islets or involve another metabolic oscillator remains to be determined.