bluuebunny/crossref_metadata_2025 huggingface dataset:
Methicillin resistance in
Staphylococcus
aureus
requires glycosylated wall teichoic acids
Authors: Brown Stephanie , Xia Guoqing , Luhachack Lyly G. , Campbell Jennifer , Meredith Timothy C. , Chen Calvin , Winstel Volker , Gekeler Cordula , Irazoqui Javier E. , Peschel Andreas , Walker Suzanne
Published: October 2012

Staphylococcus
aureus
peptidoglycan (PG) is densely functionalized with anionic polymers called wall teichoic acids (WTAs). These polymers contain three tailoring modifications:
d
-alanylation, α-
O
-GlcNAcylation, and β-
O
-GlcNAcylation. Here we describe the discovery and biochemical characterization of a unique glycosyltransferase, TarS, that attaches β-
O
-GlcNAc (β-
O
-
N
-acetyl-
d
-glucosamine) residues to
S. aureus
WTAs. We report that methicillin resistant
S. aureus
(MRSA) is sensitized to β-lactams upon
tarS
deletion. Unlike strains completely lacking WTAs, which are also sensitive to β-lactams, Δ
tarS
strains have no growth or cell division defects. Because neither α-
O
-GlcNAc nor β-
O
-Glucose modifications can confer resistance, the resistance phenotype requires a highly specific chemical modification of the WTA backbone, β-
O
-GlcNAc residues. These data suggest β-
O
-GlcNAcylated WTAs scaffold factors required for MRSA resistance. The β-
O
-GlcNAc transferase identified here, TarS, is a unique target for antimicrobials that sensitize MRSA to β-lactams.
Rhetoric, Rationality, and Judicial Activism: The Case of Hillary Goodridge v. Department of Public Health
Authors: Tell Dave , Miller Eric Carl
Published: September 2012

This article considers the relationship between rhetoric and judicial activism. A term first coined by Arthur Schlesinger Jr. in 1947, the charge of judicial activism has become ubiquitous in modern political and legal discourse, frequently leveled at judicial opinions with which one disagrees. Despite focused attention from legal scholars in recent years, the term continues to defy easy definition. After surveying the relevant legal scholarship on judicial activism, this article considers a widely decried example of activism in action. Taking the 2003 case of Hillary Goodridge v. Department of Public Health as a case study, the authors examine the five judicial opinions, paying particular attention to how each justice justifies his or her decision with recourse to one of three rhetorical forms (legal analysis, the discourse of science, and public consensus). We conclude that the legitimacy of judicial activism is a function of particular rhetorical forms (and not others).
“Pardon Me for the Digression”: Robert Forten and James Forten Jr. Address the Philadelphia Female Anti-Slavery Society
Authors: McClish Glen
Published: September 2012

This study features two speeches by African American abolitionists Robert B. Forten and James Forten Jr., who in the 1830s addressed the Philadelphia Female Anti-Slavery Society. Their orations simultaneously appeal to conventional nineteenth-century, white, upper- and middle-class notions of womanhood while drawing upon arguments that more typically inform male abolitionist rhetoric. In addition, both men emphasize traditional racial differences while seeking to establish links with their listeners that transcend these differences. The development of a powerful collective sense of identity, achieved through the constitutive quality of their arguments, forms the speeches' best opportunity to serve abolition.
Consilium: A System to Address Deliberative Uncertainty in the Rhetoric of the Middle Ages
Authors: Ramsey Shawn D.
Published: September 2012

This article treats the idea of consilium as a concept in the rhetoric of the Western Middle Ages. The tradition of civic oratory in antiquity was associated with the deliberative genre, and civic speech was perpetuated in the Middle Ages but manifested itself as consilium. In the letters of Fulbert of Chartres, the rhetorical commentaries of Thierry of Chartres, and the rhetorical treatises of Albertanus of Brescia and Brunetto Latini, the concept of consilium (“counsel”) systematically describes persuasive human interaction to address deliberative uncertainty about future civic decisions. Medieval rhetoricians use the term consilium both synonymously with deliberation and to describe an activity of persuasion that is akin to deliberative oratory. In rhetorical texts describing the practice of counsel in the Middle Ages, we see a transition from counsel as a subject of rhetorical theory to counsel as a public practice.
Eu3+/Tb3+-codoped Y2O3 nanophosphors: Rietveld refinement, bandgap and photoluminescence optimization
Authors: Som S , Sharma S K
Published: September 2012

In this work, Eu-doped, Tb-doped and Eu, Tb-codoped Y2O3 nanophosphors were synthesized by the combustion synthesis method. The prepared phosphors were characterized by x-ray diffraction (XRD), Rietveld refinement and Fourier transform infrared (FTIR) spectroscopy. XRD studies and Rietveld refinement confirmed the body-centred cubic structure of doped and codoped phosphors. FTIR studies also confirmed the formation of these compounds. Thermal analysis results indicated that there was no phase transition for all the phosphors in the studied temperature range. In the optical properties, diffuse reflectance (DR) and photoluminescence (PL) measurements were performed. DR spectra were used to determine the bandgap and it increased in the doped and codoped samples due to the crystallite size effect. A strong characteristic emission from Eu3+ and Tb3+ ions was identified and the influence of doping concentration and annealing temperature on PL properties was systematically studied. Transfer of energy was observed from Tb3+ to Eu3+ ions in the codoped phosphor at room temperature.
A-site vacancy-induced giant strain and the electrical properties in non-stoichiometric ceramics Bi0.5+x(Na1−yKy)0.5−3xTiO3
Authors: Ni Feng , Luo Laihui , Li Weiping , Chen Hongbing
Published: September 2012

A-site vacancies were created in lead-free piezoelectric non-stoichiometric ceramics Bi0.5+x
(Na1−y
K
y
)0.5−3x
TiO3 and Bi0.5+x
(Na0.82K0.18)0.5TiO3, which were synthesized by a conventional solid-state reaction process. The ferroelectric properties, piezoelectric performances and strain behaviours of the as-prepared ceramics were characterized, and the effects of A-site vacancies on the ferroelectric properties, piezoelectric performances and strain behaviours of the ceramics were discussed. The results show that moderate A-site vacancies in the prepared ceramics enhance the piezoelectric performance of the ceramics, meanwhile, A-site vacancies lead to a decrement of depolarization temperature T
d. A large bipolar strain of 0.35% is achieved in the Bi0.505(Na0.74K0.26)0.485TiO3 ceramic at room temperature.
Piezoelectric properties of polyamide 11/NaNbO3 nanowire composites
Authors: David Charlotte , Capsal Jean-Fabien , Laffont Lydia , Dantras Eric , Lacabanne Colette
Published: September 2012

Polyamide 11(PA 11)/sodium niobate nanowire (NW) 0–3 composites with different volume fractions of NWs were synthesized. The electric polarization (P) was measured as a function of the applied electric field (E). The P–E hysteresis loop was used to work out the remanent polarization P
r of these materials. The dielectric permittivity and the piezoelectric strain constant were determined. Good impedance matching between inorganic and organic phases leads to higher electroactivity than conventional lead-free 0–3 composites. The piezoelectric voltage of the PA 11/NaNbO3 NW composites is of the same order as those obtained for fluorinated piezoelectric polymers. These composites could have some applications in flexible, low-cost, environmentally friendly piezoelectric sensors and actuators.
Epitaxial growth of ZnO film on Si(1 1 1) with CeO2(1 1 1) as buffer layer
Authors: Wong T I , Tan H R , Sentosa D , Wong L M , Wang S J , Feng Y P
Published: September 2012

ZnO(0 0 2) epitaxial films have been successfully grown on Si(1 1 1) with CeO2 as a buffer layer by pulsed laser deposition. In spite of large lattice mismatch between ZnO and CeO2, good film quality was achieved, as proven by Fourier filtered high-resolution transmission electron microscopy (HRTEM) image, due to reduction in interface strain by domain matching epitaxy. The epitaxial relationship of ZnO and CeO2 on the Si substrate was determined to be (0 0 2)[2 1 0]ZnO‖(1 1 1)[1 1 2]

(1 1 1)[1 1 2]Si. The HRTEM images show low defect concentrations in both the deposited ZnO film and CeO2 layer. Ordered crack lines are observed on the surface of the ZnO film which are due to A-type and B-type stackings of CeO2 on Si(1 1 1). Sharp near-band edge emission at 3.253 eV was detected for the ZnO film through photoluminiscence measurement at room temperature.
Transport and thermoelectric properties of n-type Ruddlesden–Popper phase (Sr1−xGdx)3(Ti1−yTay)2O7 oxides
Authors: Sun R R , Qin X Y , Li L L , Li D , Zhang J , Wang Q Q
Published: September 2012

The transport and thermoelectric properties of (Sr1−x
Gd
x
)3(Ti1−y
Ta
y
)2O7(x = 0.05, y = 0.05–0.15; x = 0.1, y = 0.05–0.1) compounds with Ruddlesden–Popper (RP) phase, prepared by a conventional solid-state reaction method plus spark plasma sintering (SPS), were investigated in the temperature range from 300 to 1000 K. The results indicate that the electrical resistivity ρ for all compounds increases with temperature, and has a relation ρ ∝ T

M
(i.e. the mobility μ ∝ T
−M
) with M = 1.58–1.92 at T ≳ 650 K, indicating that the phonon scattering is predominant. Basically, the absolute value of the Seebeck coefficient |S| increases almost linearly with temperature above ∼400 K, showing degenerated semiconducting behaviour. Moreover, both ρ and |S| decrease with the increase in both Ta and Gd content, which can be attributed to an increase in the carrier concentration. The lattice thermal conductivity κ
L of the compounds decreases monotonically with an increase in both Ta and Gd content due to mass-defect phonon scattering, and the lowest κ
L(κ
L = 3.3 W K−1m−1 at room temperature and 2.0 W K−1 m−1 at 1000 K) is achieved in (Sr0.9Gd0.1)3(Ti0.9Ta0.1)2O7. Among all the compounds investigated here, the largest dimensionless figure of merit ZT = 0.08 (at 1000 K) is obtained in the compound (Sr0.9Gd0.1)3(Ti0.95Ta0.05)2O7.
Permanent left atrial pacing therapy may improve symptoms in heart failure patients with preserved ejection fraction and atrial dyssynchrony: a pilot study prior to a national clinical research programme
Authors: Laurent Gabriel , Eicher Jean Christophe , Mathe Anaëlle , Bertaux Géraldine , Barthez Olivier , Debin Régine , Billard Clotilde , Philip Jean Luc , Wolf Jean Eric
Published: September 2012

Aims

Our group has recently shown that in some patients, heart failure with preserved ejection fraction (HFPEF) may be explained by ‘atrial dyssynchrony syndrome’ (ADS) due to interatrial conduction delay (IACD), a short left atrioventricular interval (LAVI), and increased left atrial (LA) stiffness. Our primary objective was to evaluate LA pacing therapy as a new treatment to restore left ventricular active filling in patients with no other known causes for HF than ADS.

Methods and results

Six patients with severe HFPEF with IACD (P wave duration >120 ms in lead II), short LAVI during electrophysiological studies (<70 ms), a restrictive filling pattern (E/e' >15), and no standard indication for a pacemaker were implanted with a lead screwed inside the coronary sinus for active LA pacing. After 3 months of active pacing, a 2 week randomized double‐blind crossover phase compared active vs. inactive LA pacing. After 3 months of pacing, the mean distance walked in 6 min (6MWD) was 21% greater (240 ± 25 m vs. 190 ± 15m, P < 0.05), mitral A wave duration was longer (104 ± 8 vs. 158 ± 25 ms, P = 0.002), and E/A and E/e' ratios were smaller (3.4 ± 1.3 vs. 1.8 ± 0.9, P = 0.009, and 22.6 ± 4.6 vs. 15.3 ± 4.3, P = 0.006, respectively). Inactivation of pacing for 1 week led to a significant reduction in the 6MWD, with an on/off response.

Conclusion

The beneficial effects of LA pacing observed in this pilot study will have to be confirmed by the randomized, controlled crossover ‘LEAD’ study.
Evolutionary game theory: an exposition
Authors: Lahkar Ratul
Published: September 2012

Purpose

This article aims to provide an exposition of evolutionary game theory which can be used for pedagogical purposes.

Design/methodology/approach

The exposition is presented as a mathematical model in order to cover the formal underpinnings of evolutionary game theory. The paper aims to illustrate the theory using some simple examples.

Findings

The paper discusses population games and describes the notion of revision protocols that agents use to change strategies. As an example of an evolutionary dynamic, the paper discusses the replicator dynamic in detail. It shows convergence of this dynamic to Nash equilibrium in simple 2 strategy games. The paper then applies this dynamic to a particular class of 3 strategy games to establish the possibility on cyclical behavior around a Nash equilibrium.

Originality/value

The paper can serve as an educational briefing for students and researchers who are new to the field of evolutionary game theory.
Impact of exchange rate volatility on sectoral exports of Pakistan: an ARDL investigation
Authors: Aftab Muhammad , Abbas Zaheer , Nawaz Kayani Farrukh
Published: September 2012

Purpose

The purpose of this paper is to explore the impact of exchange rate volatility at sectoral level on the exports trade of Pakistan. All the sectors involved in the export trade (proposed by the State Bank of Pakistan, by commodity), were used to study this relationship at a more minute level.

Design/methodology/approach

Quarterly data regarding research were collected over the period 2003 to 2010 from databases of State Bank of Pakistan and International Monetary Fund financial statistics. The bound testing approach proposed by Pesaran et al., was used to study the relationship between sectoral export and exchange rate volatility, while augmented Dickey Fuller (ADF) and Phillips Perron tests were used to test the unit root of series and GARCH,proposed by Bollerslev, was used to study exchange rate volatility.

Findings

The results show that exports are negatively influenced by exchange rate volatility and relative prices while positively affected by foreign income. This relationship holds for all sectors where bound testing revealed the existence of long‐ run relationship, although some equations results were not statistically significant.

Practical implications

The paper's findings can be used to form such policies which result in a stabilized and competitive exchange rate, so that Pakistan's exports can be increased.

Originality/value

Previous studies have been conducted on aggregated data set for exports in the Pakistani context, which hinders pertinent information; however this information is possible by studying disaggregated data. The paper fills a research gap by taking sectoral level data, to divulge the behavior of individual sectors against exchange rate volatility.
The development of internal auditing in Ethiopia: the role of institutional norms
Authors: Getie Mihret Dessalegn , Mula Joseph M. , James Kieran
Published: September 2012

Purpose

The purpose of this paper is to examine the extent to which institutional norms determine attributes of internal audit practices and how institutional changes explain the development of these practices.

Design/methodology/approach

The authors employed a qualitative research approach based on archival analysis and interview evidence.

Findings

Findings indicate that regulation‐based institutional norms explain the adoption of internal audit and the function's characteristics in Ethiopian organizations. Furthermore, innovative introduction of internal audit practices originate within individual organizations and eventually get institutionalized through diffusion. Such innovations are associated with organizational size, top management characteristics, internal audit advancement in technology, and exogenous input from the external environment. Widely accepted internal audit practices, as institutional norms, are not always taken‐for‐granted at the level of individual organizations. The institutional change perspective enables explaining how new internal audit approaches are introduced to supplant old ones.

Originality/value

This study theorizes the development of internal audit practices from an institutional change perspective. Being the first study to do so, it contributes to the understanding of key drivers of institutional change that initiate new institutional norms that foster the development of internal audit through introduction and diffusion of new audit practices as old ones are deinstitutionalized.
Tax waiver year effect on earnings management practices in Malaysia
Authors: Hashim Jafni , Nizal Haniff Mohd , Kamal Abdul Rahman Ibrahim
Published: September 2012

Purpose

The purpose of this paper is to address the question of whether Malaysian public listed companies manage their earnings in response to changes in tax polices. The context of this study is the tax waiver year of 1999 which came about from the introduction of the Self Assessment System (SAS) by the Inland Revenue Board of Malaysia (IRBM) in the year 2000. If companies are to minimize tax liabilities, then the tax waiver year of 1999 may provide a substantial incentive for these companies to manage earnings in 1999.

Design/methodology/approach

The modified Jones Model (adjusted) is used to obtain the discretionary current accruals which represent earnings management. It is hypothesized that there is a significant positive discretionary current accrual (income increasing earnings management) in the tax waiver year of 1999.

Findings

The results indicate that that there is a negative relationship between earnings management and the effect of the tax waiver year of 1999. These results suggest that the magnitude of discretionary current accrual is not related to the tax waiver year in a way that is consistent with tax‐motivated income shifting behavior. Instead companies tend to manipulate earnings downwards during severe economic downturn. This is in line with Healy's bonus maximization hypothesis.

Research limitations/implications

The test sample is limited to public listed companies only and some companies are excluded due to insufficient data. Therefore, the results cannot be a representation of Malaysian companies' practices.

Originality/value

The findings of this paper contribute to the sparse literature on tax‐induced earnings management practices in Malaysia. The findings could be of value to the IRBM in designing and improving on the plans for future tax‐based incentive schemes.
Some reflections on the breadth and depth of the field of humanitarian logistics and supply chain management
Authors: Tatham Peter
Published: September 2012

Purpose

The purpose of this paper is to reflect on current research in the field of humanitarian logistics and supply chain management (SCM).

Design/methodology/approach

The paper serves as the editorial for this issue of JHLSCM.

Findings

The paper stresses the importance of the role of publications such as JHLSCM to help to bridge the gap between the theoretician and the practitioner, and between the profit and non‐profit sectors. In this way, knowledge and experience from all of these sources can be combined to deliver a more efficient and effective logistic response to natural disasters and complex emergencies.

Originality/value

The paper provides an overview of some of the key challenges in the field of humanitarian logistics and SCM.
Hired‐labor demand on Chinese household farms
Authors: Rada Nicholas E. , Wang Chenggang , Qin Lijian
Published: September 2012

Purpose

The present article presents a first‐look into the hired‐labor market in Chinese household farms using data from a national household survey conducted by the Research Center for the Rural Economy (RCRE) at China's Ministry of Agriculture. More specifically, the purpose of this paper is to evaluate the scale and dispersion of China's farm‐household hired laborers among 15 commodities, and test whether market factors influence labor‐hiring decisions – an expectation of a well‐functioning labor market. This research contributes to the literature concerned with the labor constraints facing Chinese household farms, especially those producing seasonal commodities.

Design/methodology/approach

An econometric approach is employed to assess whether Chinese farms that hire labor are responding to market factors using two repeated cross‐sections (2006, 2007) of household survey data collected by the Research Center for Rural Economy at China's Ministry of Agriculture.

Findings

The paper finds hired labor use on very small‐scale farms is surprisingly prevalent, in contrast to previously published data. The regression results suggest that labor hiring by Chinese farm households, irrespective of farm size, responds strongly to market signals and resource constraints – more labor will be hired when the wage is lower, when output is higher, and among families with fewer family members available to farm work. And the response is particularly robust for wheat, rice, and maize, whose prices are predominant determinants of the food price index.

Research limitations/implications

This paper is limited in its time‐series dimension and data availability. Despite those limitations, the results hold implications for further understanding China's nascent labor market and the level to which market factors have impacted rural farm households.

Originality/value

Focusing on the as‐of‐yet unstudied market for hired labor on Chinese household farms, the present article makes a contribution by showing that hiring of labor in Chinese agriculture is much more prevalent than previously thought. It suggests that Chinese farm‐households are responding to certain labor‐market factors and that the household response does not weaken as the largest farms are omitted from the model, suggesting that even small farms are heeding market signals.
Evaluating the constraints affecting land access among urban crop farmers in metropolitan Lagos
Authors: Odudu Christopher O. , Omirin Modupe M.
Published: September 2012

Purpose

Urban crop farming as a variant of urban agriculture is a rising phenomenon in food and income generation especially in the developing countries. It is useful in fresh food supplies, recycling of urban wastes and poverty alleviation. However, as an informal activity, the greatest challenge it faces is accessibility to land. This tends to undermine the numerous contributions it can make to a city's development in terms of social, economic and environmental developments particularly its influence on climate change, fresh air supply and healthy living of the teaming urban population. There is therefore an urgent need to examine the potentials and risks associated with urban crop farming in order to identify factors that can enhance its productivity and economic viability by improving practitioners’ access to land. The purpose of the paper is to do this.

Design/methodology/approach

The study therefore conceptualized that land accessibility among urban crop farmers can be predicted from identified constraint variables. Respondents in some locations where urban crop farming was found to be thriving well within the Lagos Metropolis were randomly selected and administered with structured questionnaires.

Findings

The data collected were analyzed using factor (principal component) analysis which enabled the construction of a constraints analysis equation or regression equation.

Originality/value

The study identified five constraints affecting land accessibility among urban crop farmers with the most critical factors being affordability and security of tenure.
16S rRNA survey revealed complex bacterial communities and evidence of bacterial interference on human adenoids
Authors: Ren Tiantian , Glatt Dominique Ulrike , Nguyen Tam Nhu , Allen Emma Kaitlynn , Early Stephen V. , Sale Michele , Winther Birgit , Wu Martin
Published: September 2012

Adenoid microbiota plays an important role in the development of various infectious and non‐infectious diseases of the upper airways, such as otitis media, adenotonsillitis, rhinosinusitis and adenoid hypertrophy. Studies have suggested that adenoids could act as a potential reservoir of opportunistic pathogens. However, previous bacterial surveys of adenoids were mainly culture based and therefore might only provide an incomplete and potentially biased assessment of the microbial diversity. To develop an in‐depth and comprehensive understanding of the adenoid microbial communities and test the ‘pathogen reservoir hypothesis’, we carried out a 16S rRNA based, culture‐independent survey of bacterial communities on 67 human adenoids removed by surgery. Our survey revealed highly diverse adenoid bacterial communities distinct from those of other body habitats. Despite large interpersonal variations, adenoid microbiota shared a core set of taxa and can be classified into at least five major types based on its bacterial species composition. Our results support the ‘pathogen reservoir hypothesis’ as we found common pathogens of otitis media to be both prevalent and abundant. Co‐occurrence analyses revealed evidence consistent with the bacterial interference theory in that multiple common pathogens showed ‘non‐coexistence’ relationships with non‐pathogenic members of the commensal microflora.
Highways versus pipelines: contributions of two fungal transport mechanisms to efficient bioremediation
Authors: Banitz Thomas , Johst Karin , Wick Lukas Y. , Schamfuß Susan , Harms Hauke , Frank Karin
Published: September 2012

Based on experimental studies, two different fungus‐mediated transport mechanisms have been suggested to facilitate the bacterial degradation of organic soil pollutants: bacteria may use liquid films around fungal hyphae for quick dispersal (‘fungal highways’), and fungi may take up and translocate pollutants through their mycelial network (‘fungal pipelines’). Both mechanisms are anticipated to enhance the bioavailability of pollutants to degrading bacteria. Using a microbial simulation model, we therefore investigated their respective efficiency in increasing biodegradation performance. We analysed networks that act either as bacterial dispersal vectors or as pollutant translocation vectors or as a combination of both. Our results suggest that each mechanism can improve biodegradation performance. The degree of improvement, however, varies distinctly depending on the environmental conditions, and is even negligible under certain conditions. Mycelial networks acting as ‘highways’ allow bacteria to overcome motility restrictions and reach remote areas, whereas networks acting as ‘pipelines’ may initiate degradation by bringing remote pollutants to bacteria. As a consequence, highest biodegradation improvements often emerge from the combination of both mechanisms. We conclude that ‘fungal highways’ as well as ‘fungal pipelines’ should be considered for developing novel bioremediation strategies based on fungus‐mediated transport in soils.
Turning Up the Volume: An Experimental Investigation of the Role of Mutual Monitoring in Tournaments
Authors: Hannan R. Lynn , Towry Kristy L. , Zhang Yue (May)
Published: September 2012

This study investigates experimentally how mutual monitoring affects effort when employees are compensated via rank‐order tournaments. Theory and anecdotal evidence suggest that mutual monitoring may either decrease effort by facilitating collusion or increase effort by stimulating competition. In our first experiment, we find that mutual monitoring increases effort, because participants do not attempt to collude but rather behave competitively. This result leads us to expand our theory and develop hypotheses to predict that the effect of mutual monitoring depends on whether employees have the inclination to collude or compete. Specifically, we predict that mutual monitoring decreases effort when employees are inclined to collude and increases effort when employees are inclined to compete; that is, mutual monitoring will not change the basic inclination created by the workplace setting, but will “turn up the volume” on the effect that such inclination has on effort. Consistent with our predictions, our second experiment finds that mutual monitoring leads to lower effort when participants have a collusive inclination and (eventually) higher effort when they have a competitive inclination. Overall, the results from these two experiments suggest that allowing employees to observe each other's productive effort in tournament incentive settings may have positive or negative consequences for the firm, depending on whether environmental factors predispose employees to collude or compete.
Closed‐loop double‐vasopressor automated system to treat hypotension during spinal anaesthesia for caesarean section: a preliminary study
Authors: Sia A. T. H. , Tan H. S. , Sng B. L.
Published: September 2012

Hypotension occurs in most caesarean sections under spinal anaesthesia, necessitating vasopressor administration. However, the optimal dosing regimen remains unclear. We have developed a novel vasopressor delivery system that automatically administers phenylephrine or ephedrine based on continuous non‐invasive blood pressure monitoring. This prospective cohort study recruited 55 healthy women under standardised spinal anaesthesia with 2.2 ml hyperbaric bupivacaine 0.5%, 15 μg fentanyl and 100 μg morphine. A 50‐μg phenylephrine bolus was given at 1‐min intervals when systolic blood pressure fell below 90% of baseline, and a 4‐mg ephedrine bolus was given when hypotension developed with bradycardia (heart rate <60 beats.min−1). Systolic blood pressure was within 20% of baseline in 88% of all measurements. Six patients (11%) had one or more measurements above 120% of baseline (1% of all measurements), whereas 36 (65%) had at least one reading below 80% of baseline (11% of total measurements). The system maintained systolic blood pressure at a mean (SD) of −9.1 (7.0)% below baseline, with 5.4 (2.5)% fluctuation. Two patients (4%) experienced pre‐delivery nausea. All 5‐min Apgar scores were 9.
Foredeep palaeobathymetry and subsidence trends during advancing then retreating subduction: the Northern Apennine case (Oligocene‐Miocene, Italy)
Authors: Di Giulio A. , Mancin N. , Martelli L. , Sani F.
Published: September 2012

The Northern Apennines provide an example of long‐term deep‐water sedimentation in an underfilled pro‐foreland basin first linked to an advancing orogenic wedge and then to a retreating subduction zone during slab rollback. New palaeobathymetric and geohistory analyses of turbidite systems that accumulated in the foredeep during the Oligocene‐Miocene are used to unravel the basin subsidence history during this geodynamic change, and to investigate how it interplayed with sediment supply and basin tectonics in controlling foredeep filling. The results show an estimated ca. 2 km decrease in palaeowater depth at ca. 17 Ma. Moreover, a change in basin subsidence is documented during Langhian time, with an average decompacted subsidence rate, during individual depocentre life, that increased from <0.3 to 0.4–0.6 mm y−1, together with the appearance of a syndepositional backstripped subsidence bracketed between 0.1 and 0.2 mm y−1. This change prevented the basin from complete filling during late Miocene and is interpreted as the foredeep response to initial rollback of the downgoing Adriatic slab. Thus, the Northern Apennine system provides an example of a pro‐foreland basin that experienced both a slow‐ and high‐subsidence regime as a consequence of the advancing then retreating evolution of the collisional system.
Ex vivo antimicrobial efficacy of the EndoVac® system plus photodynamic therapy associated with calcium hydroxide against intracanal Enterococcus faecalis
Authors: Miranda R. G. , Santos E. B. , Souto R. M. , Gusman H. , Colombo A. P. V.
Published: September 2012

Aim

To evaluate the ex vivo efficacy of the EndoVac® system and photodynamic treatment (PDT) as adjuncts to chemomechanical debridement associated with calcium hydroxide (CaOH2) in reducing the levels of intracanal Enterococcus faecalis.

Methodology

One hundred and twenty‐five sterile premolar teeth were conventionally accessed, prepared and then contaminated with E. faecalis (ATCC 29212) for 30 days. Teeth were randomly divided into 4 groups: Control (chemomechanical debridement with conventional irrigation); Endovac (chemomechanical debridement with EndoVac® system); PDT (chemomechanical debridement with conventional irrigation and PDT) and Endovac+PDT (chemomechanical debridement with EndoVac® and PDT). The irrigants used in all groups were 5.25% sodium hypochlorite and 17% EDTA. After treatment, an intracanal dressing (CaOH2) was applied in all canals for 7 days. Samples were obtained before (T1) and after the therapeutic procedures (T2) and, after intracanal medication (T3), plated onto BHI media and incubated (37 °C, 48 h) to determine the colony‐forming units (CFU mL−1).

Results

The overall mean cell counts (CFU mL−1) of E. faecalis were high at the initial contamination (T1). A significant reduction (P < 0.05) of E. faecalis mean counts was observed in all groups from baseline (T1) to both post‐therapy samplings (T2 and T3); no differences amongst the groups were detected. No significant change in bacterial counts from T2 to T3 was detected.

Conclusion

The adjunctive use of the EndoVac® system and the photodynamic treatment, in combination or not, was as effective as the conventional chemomechanical debridement associated with CaOH2 on reducing the counts of intracanal E. faecalis.
Traumatic dental injury with treatment needs negatively affects the quality of life of Brazilian schoolchildren
Authors: Damé‐Teixeira Nailê , Alves Luana S. , Ardenghi Thiago M. , Susin Cristiano , Maltz Marisa
Published: September 2012

Background

Traumatic dental injury (TDI) has been considered a significant problem in youth, not only because of its consequences to the craniofacial structures but also for its potential impact on the quality of life of affected individuals.

Aim

The aim of this study was to investigate the impact of TDI with treatment needs on the oral health–related quality of life (OHRQoL) of South Brazilian schoolchildren.

Design

A cross‐sectional study was performed in Porto Alegre, Brazil, using a multistage probability sampling strategy. Of 1837 eligible 12‐year‐old schoolchildren attending public and private schools, 1528 were examined. OHRQoL was assessed by the Brazilian version of the Child Perceptions Questionnaire for 11‐to 14‐year‐old children (CPQ11–14) – 16‐item short form. Clinical examination was conducted to assess the presence of TDI in permanent incisors (Children's Dental Health Survey criteria), malocclusion, and dental caries. Parents/legal guardians answered questions on socioeconomic status. Statistical analyses were performed using Poisson regression models.

Results

The overall CPQ11–14 score was not associated with TDI. In the functional limitations domain, individuals presenting TDIs with treatment needs experienced significantly higher mean CPQ11–14 than individuals with no TDI or without treatment needs (RR = 1.21; 95% CI = 1.05–1.39), after adjusting for malocclusion, dental caries, gender, and socioeconomic status. No other domains were associated with TDI.

Conclusions

This study revealed that TDI with treatment needs negatively affects the OHRQoL in this population of 12‐year‐old schoolchildren and that this impact is related to oral functions.
Prophylactic ranitidine treatment in critically ill children – a population pharmacokinetic study
Authors: Hawwa Ahmed F. , Westwood Paul M. , Collier Paul S. , Millership Jeffrey S. , Yakkundi Shirish , Thurley Gillian , Shields Mike D. , Nunn Anthony J. , Halliday Henry L. , McElnay James C.
Published: September 2012

Aims

To characterize the population pharmacokinetics of ranitidine in critically ill children and to determine the influence of various clinical and demographic factors on its disposition.

Methods

Data were collected prospectively from 78 paediatric patients (n = 248 plasma samples) who received oral or intravenous ranitidine for prophylaxis against stress ulcers, gastrointestinal bleeding or the treatment of gastro‐oesophageal reflux. Plasma samples were analysed using high‐performance liquid chromatography, and the data were subjected to population pharmacokinetic analysis using nonlinear mixed‐effects modelling.

Results

A one‐compartment model best described the plasma concentration profile, with an exponential structure for interindividual errors and a proportional structure for intra‐individual error. After backward stepwise elimination, the final model showed a significant decrease in objective function value (−12.618; P < 0.001) compared with the weight‐corrected base model. Final parameter estimates for the population were 32.1 l h−1 for total clearance and 285 l for volume of distribution, both allometrically modelled for a 70 kg adult. Final estimates for absorption rate constant and bioavailability were 1.31 h−1 and 27.5%, respectively. No significant relationship was found between age and weight‐corrected ranitidine pharmacokinetic parameters in the final model, with the covariate for cardiac failure or surgery being shown to reduce clearance significantly by a factor of 0.46.

Conclusions

Currently, ranitidine dose recommendations are based on children's weights. However, our findings suggest that a dosing scheme that takes into consideration both weight and cardiac failure/surgery would be more appropriate in order to avoid administration of higher or more frequent doses than necessary.
Interval anisotropic parameter estimation from walkaway vertical seismic profiling data
Authors: Blias Emil
Published: September 2012

This paper presents a new explicit method for the estimation of layered vertical transverse isotropic (VTI) anisotropic parameters from walkaway VSP data. This method is based on Dix‐type normal moveout (NMO) inversion. To estimate interval anisotropic parameters above a receiver array, the method uses time arrivals of surface‐related double‐reflected downgoing waves. A three‐term NMO approximation function is used to estimate NMO velocity and a non‐hyperbolic parameter. Assuming the vertical velocity is known from zero‐offset VSP data, Dix‐type inversion is applied to estimate the layered Thomsen anisotropic parameters ɛ, δ above the receivers array. Model results show reasonable accuracy for estimates through Dix‐type inversion. Results also show that in many cases we can neglect the influence of the velocity gradient on anisotropy estimates. First breaks are used to estimate anisotropic parameters within the walkaway receiver interval. Analytical uncertainty analysis is performed to NMO parameter estimates. Its conclusions are confirmed by modelling.
Environmental and individual drivers of animal movement patterns across a wide geographical gradient
Authors: Avgar Tal , Mosser Anna , Brown Glen S. , Fryxell John M.
Published: September 2012

Within the rapidly developing field of movement ecology, much attention has been given to studying the movement of individuals within a subset of their population's occupied range. Our understanding of the effects of landscape heterogeneity on animal movement is still fairly limited as it requires studying the movement of multiple individuals across a variety of environmental conditions. Gaining deeper understanding of the environmental drivers of movement is a crucial component of predictive models of population spread and habitat selection and may help inform management and conservation.

In Ontario, woodland caribou (Rangifer tarandus caribou) occur along a wide geographical gradient ranging from the boreal forest to the Hudson Bay floodplains. We used high‐resolution GPS data, collected from 114 individuals across a 450 000 km2 area in northern Ontario, to link movement behaviour to underlying local environmental variables associated with habitat permeability, predation risk and forage availability.

We show that a great deal of observed variability in movement patterns across space and time can be attributed to local environmental conditions, with residual individual differences that may reflect spatial population structure.

We discuss our results in the context of current knowledge of movement and caribou ecology and highlight potential applications of our approach to the study of wide‐ranging animals.
A high proportion of blue light increases the photosynthesis capacity and leaf formation rate of Rosa × hybrida but does not affect time to flower opening
Authors: Terfa Meseret Tesema , Solhaug Knut Asbjørn , Gislerød Hans Ragnar , Olsen Jorunn Elisabeth , Torre Sissel
Published: September 2012

Alterations in light quality affect plant morphogenesis and photosynthetic responses but the effects vary significantly between species. Roses exhibit an irradiance‐dependent flowering control but knowledge on light quality responses is scarce. In this study we analyzed, the responses in morphology, photosynthesis and flowering of Rosa × hybrida to different blue (B) light proportions provided by light‐emitting diodes (LED, high B 20%) and high pressure sodium (HPS, low B 5%) lamps. There was a strong morphological and growth effect of the light sources but no significant difference in total dry matter production and flowering. HPS‐grown plants had significantly higher leaf area and plant height, yet a higher dry weight proportion was allocated to leaves than stems under LED. LED plants showed 20% higher photosynthetic capacity (Amax) and higher levels of soluble carbohydrates. The increase in Amax correlated with an increase in leaf mass per unit leaf area, higher stomata conductance and CO2 exchange, total chlorophyll (Chl) content per area and Chl a/b ratio. LED‐grown leaves also displayed a more sun‐type leaf anatomy with more and longer palisade cells and a higher stomata frequency. Although floral initiation occurred at a higher leaf number in LED, the time to open flowers was the same under both light conditions. Thereby the study shows that a higher portion of B light is efficient in increasing photosynthesis performance per unit leaf area, enhancing growth and morphological changes in roses but does not affect the total Dry Matter (DM) production or time to open flower.
Rebamipide ameliorates indomethacin‐induced small intestinal injury in rats via the inhibition of matrix metalloproteinases activity
Authors: Yamada Shinya , Naito Yuji , Takagi Tomohisa , Mizushima Katsura , Horie Ryusuke , Fukumoto Kohei , Inoue Ken , Harusato Akihito , Uchiyama Kazuhiko , Handa Osamu , Yagi Nobuaki , Ichikawa Hiroshi , Yoshikawa Toshikazu
Published: September 2012

Background and Aim

The pathogenesis of non‐steroidal anti‐inflammatory drugs (NSAIDs)‐induced small intestinal lesions remains unclear, although it is considered to be quite different from that of upper gastrointestinal tract ulcers due to the absence of acid and the presence of bacteria and bile in the small intestine. The aim of this study was to characterize specific gene expression profiles of intestinal mucosa in indomethacin‐induced small intestinal injury, and to investigate the effects of rebamipide on the expression of these genes.

Methods

Intestinal injury was induced in male Wistar rats by subcutaneous administration of indomethacin. Total RNA of the intestinal mucosa was extracted 24 h after indomethacin administration, gene expression was investigated using microarray analysis, and the identified genes were confirmed by real‐time polymerase chain reaction (PCR). In addition, we investigated whether the treatment with rebamipide altered the expression of these identified genes.

Results

The administration of indomethacin induced small intestine injuries, and these lesions were significantly inhibited by the treatment with rebamipide. Microarray analysis showed that the genes for several matrix metalloproteinases (MMPs) and several chemokine‐related genes were significantly upregulated, and metallothionein 1a (MT1a) was downregulated in the intestinal mucosa after administration of indomethacin. The expressions of these genes were reversed by the treatment with rebamipide.

Conclusion

These data suggest that MMPs, chemokines, and MT1a may play an important role in the intestinal mucosal injury induced by indomethacin. In particular, the inhibition of MMP genes and chemokine‐related genes by rebamipide may be important for the therapeutic effect against NSAIDs‐induced small intestinal injury.
Outcome and determinants of mortality in 269 patients with combination anti‐tuberculosis drug‐induced liver injury
Authors: Devarbhavi Harshad , Singh Rajvir , Patil Mallikarjun , Sheth Keyur , Adarsh Channagiri Krishnamurthy , Balaraju Girisha
Published: September 2012

Background and Aim

Worldwide anti‐tuberculosis (TB) drug‐induced liver disease (DILI) is an important cause of hepatotoxicity, and drug‐induced acute liver failure (ALF). Reported series on anti‐TB DILI are limited by a mix of cases with mild transaminase elevation or adaptation. Our aim was to analyze the clinical features, laboratory characteristics, outcome, and determine predictors of 90‐day mortality.

Methods

Single center analysis of consecutive cases of anti‐TB DILI following combination anti‐TB drugs exposure from 1997–2011.

Results

Of the 269 patients, 191 (71%) experienced jaundice and 69 (25.7%) accounted for ALF. The mean age and treatment duration was 41.3 years and 1.9 months, respectively; males constituted 55.7%. DILI occurred throughout the course of treatment; three‐quarters occurred within the first 2 months. HIV infection was present in 21 (7.8%). The 90‐day mortality was 22.7%. DILI accompanied by jaundice (n = 191), encephalopathy (n = 69) or ascites (n = 69) resulted in mortality in 30%, 69.6% and 50.7%, respectively (P < 0.001). Age, gender, transaminase levels, HIV or hepatitis B surface antigen (HBsAg) status did not influence survival. Treatment duration, encephalopathy, ascites, bilirubin, serum albumin, international normalized ratio (INR), serum creatinine and leukocyte count were associated with mortality (P < 0.001). Multivariate logistic regression model for mortality, incorporating encephalopathy, albumin, bilirubin, INR, and creatinine yielded a C‐statistic of 97%.

Conclusions

Anti‐TB DILI occurs throughout treatment duration progressing to ALF in a quarter of patients. The overall mortality is 22.7%, which is higher when accompanied by jaundice, ascites or encephalopathy. An anti‐TB DILI model, incorporating bilirubin, INR, encephalopathy, serum creatinine and albumin predicted mortality with C‐statistic of 97%.
Hepatitis B virus reactivation associated with anti‐neoplastic therapy
Authors: Yeo Winnie , Chan Henry LY
Published: September 2012

Reactivation of hepatitis B virus (HBV) infection is a known complication during and after anti‐cancer therapy. This condition can affect two patient populations: it is most commonly seen in patients who are seropositive for hepatitis B surface antigen (HBsAg), but it is also being increasingly reported among patients who are HBsAg‐negative but who have prior infection, as evident by seropositive status for antibody to hepatitis B core antigen (anti‐HBc), irrespective of their anti‐HBs (antibody to HBsAg) status. The clinical course can vary from asymptomatic hepatitis to fulminant hepatic failure that can be potentially fatal. With the increasing use of biological agents in addition to potent cytotoxic chemotherapy in the armamentarium of anti‐cancer treatments, reactivation of hepatitis B has become a common clinical situation that is faced by both oncologists and hepatologists especially in HBV endemic areas. In this review, we discuss the clinical course of reactivation in the two HBV‐infected sub‐populations, and the role of anti‐virals in the prevention and management of HBV reactivation in association with cytotoxic chemotherapy and biological therapies.