bluuebunny/crossref_metadata_2025 huggingface dataset:
A clinically relevant validation method for implant placement after virtual planning
Authors: Verhamme Luc M. , Meijer Gert J. , Boumans Tiny , Schutyser Filip , Bergé Stefaan J. , Maal Thomas J. J.
Published: August 2012

Purpose

To design a relevant method to compare the virtual planned implant position to the ultimately achieved implant position and to evaluate, in case of discrepancy, the cause for this.

Materials and Methods

Five consecutive edentulous patients with retention problems of the upper denture received four implants in the maxilla. Preoperatively, first a cone‐beam CT (CBCT) scan was acquired, followed by virtual implant planning. Then, a surgical template was designed and endosseous implants were flapless installed using the template as a guide. To inventory any differences in position, the postoperative CBCT scan was matched to the preoperative scan. The accuracy of implant placement was validated three‐dimensionally (3D) and the Implant Position Orthogonal Projection (IPOP) validation method was applied to project the results to a bucco‐lingual and mesio‐distal plane. Subsequently, errors introduced by virtual planning, surgical instruments, and validation process were evaluated.

Results

The bucco‐lingual deviations were less obvious than mesio‐distal deviations. A maximum linear tip deviation of 2.84 mm, shoulder deviation of 2.42 mm, and angular deviation of 3.41° were calculated in mesio‐distal direction. Deviations included errors in planning software (maximum 0.15 mm), for surgical procedure (maximum 2.94°), and validation process (maximum 0.10 mm).

Conclusions

This study provides the IPOP validation method as an accurate method to evaluate implant positions and to elucidate inaccuracies in virtual implant planning systems.
Maternal obesity and breastfeeding intention, initiation, intensity and duration: a systematic review
Authors: Turcksin Rivka , Bel Sarah , Galjaard Sander , Devlieger Roland
Published: August 2012

This systematic review investigates the relationship between maternal obesity and breastfeeding intention, initiation, intensity, duration and milk supply. A comprehensive search was performed through three major databases, including Medline, Cochrane Library and Cumulative Index For Nursing and Allied Health Literature, and by screening reference lists of the relevant publications. Selection criteria were: report of original research, studies on low‐risk obese mothers and the comparison with normal weight mothers which met at least two of the following primary outcomes: breastfeeding intention; initiation; intensity; duration and/or milk supply. Furthermore, the included reports had to contain a clear definition of pre‐pregnant obesity, use compensation mechanisms for potential confounding factors, have a prospective cohort design and had to have been published between 1997 and 2011 and in English, French or Dutch. Effects of obesity on breastfeeding intention, initiation, intensity, duration and milk supply were analysed, tabulated and summarised in this review. Studies have found that obese women are less likely to intend to breastfeed and that maternal obesity seems to be associated with a decreased initiation of breastfeeding, a shortened duration of breastfeeding, a less adequate milk supply and delayed onset of lactogenesis II, compared with their normal weight counterparts. This systematic review indicates therefore that maternal obesity is an adverse determinant for breastfeeding success.
Maternal HIV is associated with reduced growth in the first year of life among infants in the Eastern region of Ghana: the Research to Improve Infant Nutrition and Growth (RIING) Project
Authors: Lartey Anna , Marquis Grace S. , Mazur Robert , Perez‐Escamilla Rafael , Brakohiapa Lucy , Ampofo William , Sellen Daniel , Adu‐Afarwuah Seth
Published: August 2012

Children of HIV‐infected mothers experience poor growth, but not much is understood about the extent to which such children are affected. The Research to Improve Infant Nutrition and Growth (RIING) Project used a longitudinal study design to investigate the association between maternal HIV status and growth among Ghanaian infants in the first year of life. Pregnant women in their third trimester were enrolled into three groups: HIV‐negative (HIV‐N, n = 185), HIV‐positive (HIV‐P, n = 190) and HIV‐unknown (HIV‐U, n = 177). Socioeconomic data were collected. Infant weight and length were measured at birth and every month until 12 months of age. Weight‐for‐age (WAZ), weight‐for‐length (WLZ) and length‐for‐age (LAZ) z‐scores were compared using analysis of covariance. Infant HIV status was not known as most mothers declined to test their children's status at 12 months. Adjusted mean WAZ and LAZ at birth were significantly higher for infants of HIV‐N compared with infants of HIV‐P mothers. The prevalence of underweight at 12 months in the HIV‐N, HIV‐P and HIV‐U were 6.6%, 27.5% and 9.9% (P < 0.05), respectively. By 12 months, the prevalence of stunting was significantly different (HIV‐N = 6.0%, HIV‐P = 26.5% and HIV‐U = 5.0%, P < 0.05). The adjusted mean ± SE LAZ (0.57 ± 0.11 vs. −0.95 ± 0.12; P < 0.005) was significantly greater for infants of HIV‐N mothers than infants of HIV‐P mothers. Maternal HIV is associated with reduce infant growth in weight and length throughout the first year of life. Children of HIV‐P mothers living in socioeconomically deprived communities need special support to mitigate any negative effect on growth performance.
The effect and safety of dressing composed by nylon threads covered with metallic silver in wound treatment
Authors: Brogliato Ariane R , Borges Paula A , Barros Janaina F , Lanzetti Manuela , Valença Samuel , Oliveira Nesser C , Izário‐Filho Hélcio J , Benjamim Claudia F
Published: August 2012

Silver is used worldwide in dressings for wound management. Silver has demonstrated great efficacy against a broad range of microorganisms, but there is very little data about the systemic absorption and toxicity of silver in vivo. In this study, the antimicrobial effect of the silver‐coated dressing (SilverCoat®) was evaluated in vitro against the most common microorganisms found in wounds, including Pseudomonas aeruginosa, Candida albicans, Staphylococcus aureus, Methicillin‐resistant Staphylococcus aureus and Klebsiella pneumoniae. We also performed an excisional skin lesion assay in mice to evaluate wound healing after 14 days of treatment with a silver‐coated dressing, and we measured the amount of silver in the blood, the kidneys and the liver after treatment. Our data demonstrated that the nylon threads coated with metallic silver have a satisfactory antimicrobial effect in vitro, and the prolonged use of these threads did not lead to systemic silver absorption, did not induce toxicity in the kidneys and the liver and were not detrimental to the normal wound‐healing process.
Natural Obsidian Glass as an External Accuracy Reference Material in Laser Ablation‐Inductively Coupled Plasma‐Mass Spectrometry
Authors: Ulrich Thomas , Kamber Balz S.
Published: August 2012

Compared with solution ICP‐MS, LA‐ICP‐MS studies have thus far reported comparatively few external reference data for accuracy estimates of experiments. This is largely the result of a paucity of available reference materials of natural composition. Here, we report an evaluation of natural glass (obsidian) as an inexpensive and widely available external reference material. The homogeneity of over forty elements in six different obsidian samples was assessed by LA‐ICP‐MS. Accuracy was tested with two obsidian samples that were fully characterised by electron probe microanalysis and solution ICP‐MS. Laser ablation experiments were performed with a variety of ablation parameters (fluence, spot sizes, ablation repetition rates) and calibration approaches (natural vs. synthetic reference materials, and different internal standard elements) to determine the best practice for obsidian analysis. Furthermore, the samples were analysed using two different laser wavelengths (193 nm and 213 nm) to compare the effect of potential ablation‐related phenomena (e.g., fractionation). Our data indicate that ablation with fluences larger than 6 J cm−2 and repetition rates of 5 or 10 Hz resulted in the most accurate results. Furthermore, synthetic NIST SRM 611 and 612 glasses worked better as reference materials compared with lower SiO2 content reference materials (e.g., BHVO‐2G or GOR128‐G). The very similar SiO2 content of the NIST SRM glasses and obsidian (i.e., matrix and compositional match) seems to be the first‐order control on the ablation behaviour and, hence, the accuracy of the data. The use of different internal standard elements for the quantification of the obsidian data showed that Si and Na yielded accurate results for most elements. Nevertheless, for the analysis of samples with high SiO2 concentrations, it is recommended to use Si as the internal standard because it can be more precisely determined by electron probe microanalysis. At the scale of typical LA analyses, the six obsidian samples proved to be surprisingly homogenous. Analyses with a spot size of 80 μm resulted in relative standard deviations (% RSD) better than 8% for all but the most depleted elements (e.g., Sc, V, Ni, Cr, Cu, Cd) in these evolved glasses. The combined characteristics render obsidian a suitable, inexpensive and widely available, external quality‐control material in LA‐ICP‐MS analysis for many applications. Moreover, obsidian glass is suited for tuning purposes, and well‐characterised obsidian could even be used as a matrix‐matched reference material for a considerable number of elements in studies of samples with high SiO2 contents.
Iron therapy in cancer‐induced anemia
Authors: GASCÓN PERE
Published: August 2012

Erythropoiesis‐stimulating agents (ESAs) are widely used in oncology to correct the anemia associated with chemotherapy, although only 50–70% of patients show an optimal response, mostly because of functional iron deficiency (FID). As intravenous (IV) iron can overcome this FID, it has become an important adjunct to obtaining and maintaining adequate hemoglobin levels in patients with cancer receiving chemotherapy. In fact, six out of seven published randomized, controlled trials performed in cancer patients have demonstrated that IV iron given concomitantly to ESAs induces a faster and much more robust response than with ESAs alone. The possibility that giving only IV iron can also produce adequate hemoglobin responses requires further studies. However, there still exists some reluctance among many oncologists to use IV iron because of the poor safety profile observed in the past with the old iron preparations, in particular high‐molecular‐weight iron dextran. As the efficacy and safety of the new iron preparations have been proven, the use of IV iron should be considered in the management of anemia secondary to chemotherapy treatments.
Myosin‐driven rescue of contractile reserve and energetics in mouse hearts bearing familial hypertrophic cardiomyopathy‐associated mutant troponin T is mutation‐specific
Authors: He Huamei , Hoyer Kirsten , Tao Hai , Rice Ronald , Jimenez Jesus , Tardiff Jil C. , Ingwall Joanne S.
Published: August 2012

Key points

Familial hypertrophic cardiomyopathy (FHC)‐associated missense mutations in the tail portion of cardiac troponin T (cTnT) lead to a phenotype characterized by an increased cost of cardiac contraction, contractile dysfunction and impaired energetics.

Arginine 92 (R92) in cTnT is a ‘hotspot’ with many FHC‐associated missense mutations; each mutation leads to a clinically distinct cardiomyopathy. Both R92Q and R92L cTnT mutant mouse hearts exhibit the FHC phenotype.

Here we found that genetically remodelling the sarcomere by substituting αα‐myosin heavy chain (αα‐MyHC) with ββ‐MyHC normalizes the increased cost of cardiac contraction, rescuing both contractile dysfunction and energetic abnormalities, in R92Q cTnT mutant hearts, while wild‐type R92 and R92L cTnT mutant hearts were unaffected.

Our results demonstrate that the conformation of the tropomyosin‐binding domain of cTnT induced by each unique amino acid substitution at R92 is a major determinant of sarcomere function.

Abstract  The thin filament protein troponin T (TnT) is a regulator of sarcomere function. Whole heart energetics and contractile reserve are compromised in transgenic mice bearing missense mutations at R92 within the tropomyosin‐binding domain of cTnT, despite being distal to the ATP hydrolysis domain of myosin. These mutations are associated with familial hypertrophic cardiomyopathy (FHC). Here we test the hypothesis that genetically replacing murine αα‐MyHC with murine ββ‐MyHC in hearts bearing the R92Q cTnT mutation, a particularly lethal FHC‐associated mutation, leads to sufficiently large perturbations in sarcomere function to rescue whole heart energetics and decrease the cost of contraction. By comparing R92Q cTnT and R92L cTnT mutant hearts, we also test whether any rescue is mutation‐specific. We defined the energetic state of the isolated perfused heart using 31P‐NMR spectroscopy while simultaneously measuring contractile performance at four work states. We found that the cost of increasing contraction in intact mouse hearts with R92Q cTnT depends on the type of myosin present in the thick filament. We also found that the salutary effect of this manoeuvre is mutation‐specific, demonstrating the major regulatory role of cTnT on sarcomere function at the whole heart level.
Sustained NMDA receptor activation by spreading depolarizations can initiate excitotoxic injury in metabolically compromised neurons
Authors: Aiba Isamu , Shuttleworth C. William
Published: August 2012

Key points

Spreading depolarization (SD) is a profound neuronal and glial depolarization implicated in the progression of acute brain injury.

In metabolically compromised tissue, SD can trigger irrecoverable injury; however, the underlying cellular mechanisms are not well established.

We investigated consequences of SD in hippocampal brain slices, using a combination of electrophysiological and single‐cell imaging methods.

We characterized a brief period of prolonged NMDA receptor (NMDAR) activation after SD onset, which appeared to underlie extended Ca2+ elevations in dendrites.

Prolonged NMDAR activation was sufficient to cause injury after SD in metabolically compromised neurons, and therefore may contribute to deleterious consequences of SD in pathological conditions.

Abstract  Spreading depolarizations (SDs) are slowly propagating waves of near‐complete neuronal and glial depolarization. SDs have been recorded in patients with brain injury, and the incidence of SD significantly correlates with outcome severity. Although it is well accepted that the ionic dyshomeostasis of SD presents a severe metabolic burden, there is currently limited understanding of SD‐induced injury processes at a cellular level. In the current study we characterized events accompanying SD in the hippocampal CA1 region of murine brain slices, using whole‐cell recordings and single‐cell Ca2+ imaging. We identified an excitatory phase that persisted for approximately 2 min following SD onset, and accompanied with delayed dendritic ionic dyshomeostasis. The excitatory phase coincided with a significant increase in presynaptic glutamate release, evidenced by a transient increase in spontaneous EPSC frequency and paired‐pulse depression of evoked EPSCs. Activation of NMDA receptors (NMDARs) during this late excitatory phase contributed to the duration of individual neuronal depolarizations and delayed recovery of extracellular slow potential changes. Selectively targeting the NMDAR activation following SD onset (by delayed pressure application of a competitive NMDAR antagonist) significantly decreased the duration of cellular depolarizations. Recovery of dendritic Ca2+ elevations following SD were also sensitive to delayed NMDA antagonist application. Partial inhibition of neuronal energy metabolism converted SD into an irrecoverable event with persistent Ca2+ overload and membrane compromise. Delayed NMDAR block was sufficient to prevent these acute injurious events in metabolically compromised neurons. These results identify a significant contribution of a late component of SD that could underlie neuronal injury in pathological circumstances.
Stability of Frictional Sliding With the Coefficient of Friction Depended on the Temperature
Authors: Mortazavi Vahid , Wang Chuanfeng , Nosonovsky Michael
Published: August 2012

Friction-induced instabilities can be caused by different separate mechanisms such as elastodynamic or thermoelastic. This paper suggests another type of instability due to the temperature dependency of the coefficient of friction. The perturbations imposed on the surface temperature field during the frictional sliding can grow or decay. A stability criterion is formulated and a case study of a brake disk is performed with a simple model without including effects of transforming layer and chemical/physical properties change with temperature. The disk is rigid and the coefficient of friction depends on temperature. We show that the mechanism of instability can contribute to poor reproducibility of aircraft disk brake tests reported in the literature. We propose a method to increase the reproducibility by dividing the disk into several sectors with decreased thermal conductivity between the sectors.
Investigation of the Linear Stability Problem of Electrified Jets, Inviscid Analysis
Authors: Özgen Serkan , Uzol Oguz
Published: August 2012

The instability characteristics of a liquid jet discharging from a nozzle into a stagnant gas are investigated using the linear stability theory. Starting with the equations of motion for incompressible, inviscid, axisymmetric flows in cylindrical coordinates, a dispersion relation is obtained, where the amplification factor of the disturbance is related to its wave number. The parameters of the problem are the laminar velocity profile shape parameter, surface tension, fluid densities, and electrical charge of the liquid jet. The dispersion relation is numerically solved as a function of the wave number. The growth of instabilities occurs in two modes, the Rayleigh and atomization modes. For rWe<1 (where We represents the Weber number and r represents the gas-to-liquid density ratio) corresponds to a Rayleigh or long wave instability, where atomization does not occur. On the contrary, for rWe>>1 the waves at the liquid-gas interface are shorter and when they reach a threshold amplitude the jet breaks down or atomizes. The surface tension stabilizes the flow in the atomization regime, while the density stratification and electric charges destabilize it. Additionally, a fully developed flow is more stable compared to an underdeveloped one. For the Rayleigh regime, both the surface tension and electric charges destabilize the flow.
Brief Review of Exact Solutions for Slip-Flow in Ducts and Channels
Authors: Wang C. Y.
Published: August 2012

Slip flow in ducts is important in numerous contemporary applications, especially microchannel flow. This Note reviews the existing exact solutions for slip flow. These solutions serve as accuracy standards for approximate methods including numerical or semi-numerical means. Some new solutions are also introduced.
Single-Phase and Two-Phase Flow Through Thin and Thick Orifices in Horizontal Pipes
Authors: Roul Manmatha K. , Dash Sukanta K.
Published: August 2012

Two-phase flow pressure drops through thin and thick orifices have been numerically investigated with air–water flows in horizontal pipes. Two-phase computational fluid dynamics (CFD) calculations, using the Eulerian–Eulerian model have been employed to calculate the pressure drop through orifices. The operating conditions cover the gas and liquid superficial velocity ranges Vsg = 0.3–4 m/s and Vsl = 0.6–2 m/s, respectively. The local pressure drops have been obtained by means of extrapolation from the computed upstream and downstream linearized pressure profiles to the orifice section. Simulations for the single-phase flow of water have been carried out for local liquid Reynolds number (Re based on orifice diameter) ranging from 3 × 104 to 2 × 105 to obtain the discharge coefficient and the two-phase local multiplier, which when multiplied with the pressure drop of water (for same mass flow of water and two phase mixture) will reproduce the pressure drop for two phase flow through the orifice. The effect of orifice geometry on two-phase pressure losses has been considered by selecting two pipes of 60 mm and 40 mm inner diameter and eight different orifice plates (for each pipe) with two area ratios (σ = 0.73 and σ = 0.54) and four different thicknesses (s/d = 0.025–0.59). The results obtained from numerical simulations are validated against experimental data from the literature and are found to be in good agreement.
Hippo Responds to GPCRs
Authors: Foley John F.
Published: August 2012

G protein–coupled receptors can activate or inhibit the Hippo pathway in a G protein–dependent manner.
Changing Epidemiology of Extended-Spectrum β-Lactamases in Argentina: Emergence of CTX-M-15
Authors: Sennati S. , Santella G. , Di Conza J. , Pallecchi L. , Pino M. , Ghiglione B. , Rossolini G. M. , Radice M. , Gutkind G.
Published: August 2012

A multicenter survey, carried out in 2010 in Argentina, showed an increased prevalence of extended-spectrum β-lactamase (ESBL)-producing enterobacteria, with some changes in the molecular epidemiology of circulating ESBLs. While enzymes of the CTX-M-2 group remain endemic, the emergence of CTX-M-15 and of enzymes of the CTX-M-8 and CTX-M-9 groups was observed. The CTX-M-15-positive isolates represented 40% of CTX-M producers and included representatives of
Escherichia coli
ST131 and
Klebsiella pneumoniae
ST11.
A Randomized, Evaluator-Blind, Phase 2 Study Comparing the Safety and Efficacy of Omadacycline to Those of Linezolid for Treatment of Complicated Skin and Skin Structure Infections
Authors: Noel Gary J. , Draper Michael P. , Hait Howard , Tanaka S. Ken , Arbeit Robert D.
Published: August 2012

A randomized, investigator-blind, multicenter phase 2 trial involving patients with complicated skin and skin structure infections (cSSSI) compared the safety and efficacy of omadacycline, a broad-spectrum agent with activity against methicillin-resistant
Staphylococcus aureus
(MRSA), to those of linezolid (with or without aztreonam). Patients were randomized 1:1 to omadacycline (100 mg intravenously [i.v.] once a day [QD] with an option to transition to 200 mg orally QD) or linezolid (600 mg i.v. twice daily [BID] with an option to transition to 600 mg orally BID) at 11 U.S. sites. Patients suspected or documented to have infections caused by Gram-negative bacteria were given aztreonam (2 g i.v. every 12 h [q12h]) if randomized to linezolid or matching placebo infusions if randomized to omadacycline. Adverse events were reported in 46 (41.4%) omadacycline-treated and 55 (50.9%) linezolid-treated patients. Adverse events related to treatment were assessed by investigators in 24 (21.6%) omadacycline-treated and 33 (30.6%) linezolid-treated patients. The gastrointestinal tract was most commonly involved, with adverse events reported in 21 (18.9%) patients exposed to omadacycline and 20 (18.5%) exposed to linezolid. Rates of successful clinical response in the intent-to-treat (ITT) and clinical evaluable (CE) populations favored omadacycline (ITT, 88.3% versus 75.9%; 95% confidence interval [CI], 1.9 to 22.9; CE, 98.0% versus 93.2%; 95% CI, −1.7 to 11.3). For microbiologically evaluable (ME) patients with
S. aureus
infections, the clinical success rates were 97.2% (70/72) in omadacycline-treated and 92.7% (51/55) in linezolid-treated patients. This phase 2 experience supports conclusions that omadacycline is well tolerated in cSSSI patients and that this aminomethylcycline has potential to be an effective treatment for serious skin infections.
Evaluation of the Novel Combination of High-Dose Daptomycin plus Trimethoprim-Sulfamethoxazole against Daptomycin-Nonsusceptible Methicillin-Resistant Staphylococcus aureus Using an
In Vitro
Pharmacokinetic/Pharmacodynamic Model of Simulated Endocardial Vegetations
Authors: Steed Molly E. , Werth Brian J. , Ireland Cortney E. , Rybak Michael J.
Published: August 2012

Daptomycin-nonsusceptible (DNS)
Staphylococcus aureus
is found in difficult-to-treat infections, and the optimal therapy is unknown. We investigated the activity of high-dose (HD) daptomycin plus trimethoprim-sulfamethoxazole de-escalated to HD daptomycin or trimethoprim-sulfamethoxazole against 4 clinical DNS methicillin-resistant
S. aureus
(MRSA) isolates in an
in vitro
pharmacokinetic/pharmacodynamic model of simulated endocardial vegetations (10
9
CFU/g). Simulated regimens included HD daptomycin at 10 mg/kg/day for 14 days, trimethoprim-sulfamethoxazole at 160/800 mg every 12 h for 14 days, HD daptomycin plus trimethoprim-sulfamethoxazole for 14 days, and the combination for 7 days de-escalated to HD daptomycin for 7 days and de-escalated to trimethoprim-sulfamethoxazole for 7 days. Differences in CFU/g (at 168 and 336 h) were evaluated by analysis of variance (ANOVA) with a Tukey's
post hoc
test. Daptomycin MICs were 4 μg/ml (SA H9749-1, vancomycin-intermediate
Staphylococcus aureus
; R6212, heteroresistant vancomycin-intermediate
Staphylococcus aureus
) and 2 μg/ml (R5599 and R5563). Trimethoprim-sulfamethoxazole MICs were ≤0.06/1.19 μg/ml. HD daptomycin plus trimethoprim-sulfamethoxazole displayed rapid bactericidal activity against SA H9749-1 (at 7 h) and R6212 (at 6 h) and bactericidal activity against R5599 (at 72 h) and R5563 (at 36 h). A ≥8 log
10
CFU/g decrease was observed with HD daptomycin plus trimethoprim-sulfamethoxazole against all strains (at 48 to 144 h), which was maintained with de-escalation to HD daptomycin or trimethoprim-sulfamethoxazole at 336 h. The combination for 14 days and the combination for 7 days de-escalated to HD daptomycin or trimethoprim-sulfamethoxazole was significantly better than daptomycin monotherapy (
P
< 0.05) and trimethoprim-sulfamethoxazole monotherapy (
P
< 0.05) at 168 and 336 h. Combination therapy followed by de-escalation offers a novel bactericidal therapeutic alternative for high-inoculum, serious DNS MRSA infections.
Kinetic and Crystallographic Studies of Extended-Spectrum GES-11, GES-12, and GES-14 β-Lactamases
Authors: Delbrück Heinrich , Bogaerts Pierre , Kupper Michaël B. , Rezende de Castro Roberta , Bennink Sandra , Glupczynski Youri , Galleni Moreno , Hoffmann Kurt M. , Bebrone Carine
Published: August 2012

GES-1 is a class A extended-spectrum β-lactamase conferring resistance to penicillins, narrow- and expanded-spectrum cephalosporins, and ceftazidime. However, GES-1 poorly hydrolyzes aztreonam and cephamycins and exhibits very low
k
cat
values for carbapenems. Twenty-two GES variants have been discovered thus far, differing from each other by 1 to 3 amino acid substitutions that affect substrate specificity. GES-11 possesses a Gly243Ala substitution which seems to confer to this variant an increased activity against aztreonam and ceftazidime. GES-12 differs from GES-11 by a single Thr237Ala substitution, while GES-14 differs from GES-11 by the Gly170Ser mutation, which is known to confer increased carbapenemase activity. GES-11 and GES-12 were kinetically characterized and compared to GES-1 and GES-14. Purified GES-11 and GES-12 showed strong activities against most tested β-lactams, with the exception of temocillin, cefoxitin, and carbapenems. Both variants showed a significantly increased rate of hydrolysis of cefotaxime, ceftazidime, and aztreonam. On the other hand, GES-11 and GES-12 (and GES-14) variants all containing Ala243 exhibited increased susceptibility to classical inhibitors. The crystallographic structures of the GES-11 and GES-14 β-lactamases were solved. The overall structures of GES-11 and GES-14 are similar to that of GES-1. The Gly243Ala substitution caused only subtle local rearrangements, notably in the typical carbapenemase disulfide bond. The active sites of GES-14 and GES-11 are very similar, with the Gly170Ser substitution leading only to the formation of additional hydrogen bonds of the Ser residue with hydrolytic water and the Glu166 residue.
Initial reactions to the Woman's Condom by potential user groups in Shanghai, China
Authors: Coffey Patricia S , Kilbourne-Brook Maggie , Junqing Wu , Yufeng Zhang , Hongxin Zhao , Bin Wen , Na Li , Rui Zhao , Yuyan Li
Published: August 2012

Background

The Woman's Condom, a second-generation female condom, is currently being manufactured in China by the Shanghai Dahua Medical Apparatus Company. The manufacturer plans to launch the product in China.

Methods

A survey and focus group discussions were conducted with 73 women and 57 men from nine potential user groups in the Shanghai area to explore, on the basis of visual inspection of the Woman's Condom and product information, their perceptions and attitudes toward the Woman's Condom and lubricant. The potential user groups were male and female university students, male and female college-educated young people, married women and men, migrant women and men, and women working in the entertainment industry.

Results

Female condoms were a new concept for almost all study participants. Women (49%) and men (51%) reported that the Woman's Condom would make “some” or a “great” difference in their lives. Participants reported interest in using the Woman's Condom for sexually transmitted infection (STI) (50%) or dual protection (43%) rather than for pregnancy prevention alone (33%). Findings highlighted comfort, partner approval and lubricant as possible concerns.

Conclusions

Product introduction activities should be oriented toward the most likely early adopter groups (i.e. university students, college-educated young people, migrant women and women working in the entertainment industry). Lack of interest in using the new device by married women/men and migrant men may indicate that they do not perceive a need for a dual protection product since they are already using a contraceptive method and/or do not perceive themselves at risk of STIs.
Physical and temporal factors controlling the development of near-surface ground ice at Illisarvik, western Arctic coast, Canada
Authors: O’Neill H. Brendan , Burn C.R.
Published: August 2012

Near-surface permafrost was sampled in summer 2010 at 26 sites in the Illisarvik drained-lake basin and nine sites in the surrounding tundra on Richards Island, NWT, to investigate the growth of segregated near-surface ground ice. Permafrost and ground ice have developed in the lake basin since drainage in 1978. The lake bed soils are predominantly silts of varying moisture and organic-matter contents, with sandier soils near the lake margins. Excess-ice contents in the basin were also variable, and ice enrichment was observed to a maximum depth of 60 cm below the 2010 permafrost table. Shrub-covered, wet areas had the highest mean excess-ice content in the top 50 cm of permafrost (10%), while grassy, dryer areas (4%) and poorly vegetated marginal areas (<1%) were less enriched with ice. Site wetness was the most important variable associated with near-surface excess-ice content in the lake basin. Silt content was a secondary variable. Mean excess-ice content in the top 50 cm of permafrost at tundra sites (25%) was much greater than in the basin, with ice enrichment to greater depths, likely a result of the time available for permafrost aggradation since the early Holocene climatic optimum.
Effect of short-term exercise training on intramyocellular lipid content
Authors: Bajpeyi Sudip , Reed Melissa A. , Molskness Sara , Newton Christopher , Tanner Charles J. , McCartney Jennifer S. , Houmard Joseph A.
Published: August 2012

The purpose of this study was to investigate the influence of exercise training on intramyocellular lipid (IMCL) content and test the hypothesis that the effect of endurance-oriented exercise training on IMCL is dependent on characteristics of the population studied. Lean (N = 11, body mass index (BMI) = 22.2 ± 0.7 kg·m–2), obese (N = 14, BMI = 38.8 ± 1.7 kg·m–2), and type 2 diabetic (N = 9, BMI = 35.5 ± 2.5 kg·m–2) participants were examined before and after 10 consecutive days of endurance-oriented (60 min·day–1 at ~70% [Formula: see text]O2peak) exercise training. IMCL and muscle glycogen were measured by Oil-Red-O and periodic acid – Schiff staining, respectively. The results indicated that IMCL was elevated (p < 0.05) in the obese and diabetic groups compared with the lean subjects prior to training. After training, IMCL content decreased (–35%) in the participants with type 2 diabetes; there were no changes in IMCL in the lean or obese groups. Muscle glycogen content was lower in the diabetic subjects than in the lean subjects both before and after training. These data indicate that changes in IMCL with exercise training do not exhibit a universal response but rather depend on the metabolic status of the population studied.
Examination of the Moxus Modular Metabolic System by the Douglas-bag technique
Authors: Medbø Jon Ingulf , Mamen Asgeir , Beltrami Fernando G.
Published: August 2012

The purpose of this study was to examine the performance of the Moxus Modular Metabolic System from AEI Technologies, Inc. using the Douglas-bag method as reference. To achieve this, eight moderately trained subjects cycled for 5 min at constant powers from 50 to 300 W in increments of 50 W. The O2uptake was measured simultaneously by both systems during the last minute of each stage. The O2uptake reported by the Moxus system was 83 ± 78 mL·min–1higher (mean ± SD; ≈3%, +62 µmol·s–1, P < 0.001) than that reported by the Douglas-bag method; the bias varied by ≈2% between the subjects. The higher O2uptake of the Moxus system was a consequence of 1.4% ± 3.0% higher reported ventilation and 2% ± 3% higher reported O2extraction per volume of air breathed. The respiratory exchange ratio (R value) reported by the Moxus system rose proportionally to that of the Douglas-bag method and was 1% ± 2% higher for the range examined (0.75–1.10). Repeated tests of the maximal O2uptake showed a variability (coefficient of variation) of 2.5%. The study concluded that measurements by the Moxus system showed some bias and residual variation and, in addition, some systematic differences between the subjects in the O2uptake. The R value was reported quite accurately with moderate random error. Although there were some computer software and hardware instability problems that need to be solved, the Moxus system worked quite well and provided data more reliable than those of most commercial instruments.
Development and implementation of a benchmarking and metrics program for construction performance and productivity improvement1This paper is one of a selection of papers in this Special Issue on Construction Engineering and Management.
Authors: Nasir Hassan , Haas Carl T. , Rankin Jeff H. , Fayek Aminah Robinson , Forgues Daniel , Ruwanpura Janaka
Published: August 2012

To improve construction productivity and performance, it must be measured. The Construction Sector Council (CSC) has started a Labour Productivity and Project Performance Benchmarking Program for the infrastructure sector of the construction industry in Canada. Metrics were developed for project cost, time, safety, and quality performance; labour productivity; rework; project conditions; and management practices related to health and safety. Data from 19 projects located in different regions of Canada were collected and analyzed. Based on the results and on industry feedback, additional metrics for practices related to project planning, materials management, and construction supervisory skills development were developed. This paper describes the development of the program. Lessons learned during the development and implementation of the benchmarking and metrics program are summarized and steps to establish a sustainable program are identified. It is concluded that a successful program is feasible and has the potential to have broad impact.
Multiobjective genetic algorithm to allocate budgetary resources for condition assessment of water and sewer networks1This paper is one of a selection of papers in this Special Issue on Construction Engineering and Management.
Authors: Atef Ahmed , Osman Hesham , Moselhi Osama
Published: August 2012

This paper presents a framework for optimizing condition assessment policies by balancing the revealed value of information with the cost of obtaining such information. The computational platform is based on augmenting the asset condition state with an expected level of accuracy. Inaccuracies due to condition assessment reliability are evaluated using the partially observable Markov decision process. The single objective genetic algorithm is used to select the most cost-effective assets to assess considering information inaccuracy under a fixed budget. The model is extended using multiobjective genetic algorithms and fuzzy set theory to include minimizing the risk exposure based on asset consequence of failure. This methodology takes into consideration direct and indirect costs of sudden infrastructure failure and reduced level of service costs. A case study is presented using the City of Hamilton, Canada, water network to demonstrate the capabilities of the model.
Generational differences on craft workers’ perceptions of the factors affecting labour productivity1This paper is one of a selection of papers in this Special Issue on Construction Engineering and Management.
Authors: Dai Jiukun , Goodrum Paul M.
Published: August 2012

Although the current economic downturn has eased the stress of broad skilled labour shortages, it is reasonable to believe that the shortage will return when the U.S. economy rebounds. The shortage could become more substantial because the U.S. construction industry is poised to make a significant demographic shift with Baby Boomer workers approaching retirement and Generation Y workers joining the workforce. This paper investigates how different generations of craft workers perceive the factors affecting labour productivity. The data was collected through a survey of 1996 craft workers on 28 U.S. construction sites in 2004 and 2005. The analysis results reveal that: (1) Generation Y, Generation X, and Baby Boomers actually have consensus on the relative impact of productivity factors; and (2) significant differences were also observed on individual productivity factors and the primary differences among the generations were associated with tools and consumables, labour, engineering drawing management, and project policy.
DISORDER INDUCED ORDER IN AN ARRAY OF CHAOTIC DUFFING OSCILLATORS
Authors: LEI YOUMING , GUAN FULI
Published: August 2012

This paper addresses the issue of disorder induced order in an array of coupled chaotic Duffing oscillators which are excited by harmonic parametric excitations. In order to investigate the effect of phase disorder on dynamics of the array, we take into account that individual uncoupled Duffing oscillator with a parametric excitation is chaotic no matter what the initial phase of the excitation is. It is shown that phase disorder by randomly choosing the initial phases of excitations can suppress spatio-temporal chaos in the system coupled by chaotic Duffing oscillators. When all the phases are the same and deterministic, the oscillators remain chaotic and asynchronous no matter what the common phase is. When driven asynchronously by introducing phase disorder, the oscillators coupled in the array appear more regular with increase of the amplitude of random phase, and the highest level of synchrony between them is induced by intermediate phase disorder, displaying a resonance like phenomenon caused from the transition of the coupled oscillators from chaos to periodic motion. Since varying the initial phases of excitations is more feasible than altering parameters intrinsic to the oscillators coupled in an array, this study provides a practical method for control and synchronization of chaotic dynamics in high-dimensional, spatially extended systems, which might have potential applications in engineering, neuroscience and biology.
A SEMI-ON-LINE SCHEDULING PROBLEM OF TWO PARALLEL MACHINES WITH COMMON MAINTENANCE TIME
Authors: CAI YUHUA , FENG QI , LI WENJIE
Published: August 2012

In this paper, we consider a semi-on-line scheduling problem of two identical machines with common maintenance time interval and nonresumable availability. We prove a lower bound of 2.79129 on the competitive ratio and give an on-line algorithm with competitive ratio 2.79633 for this problem.
RADIATION EMISSION AND RE-ABSORPTION MECHANISMS IN DENSE MEDIUMS
Authors: MAHDAVI M. , GHAZIZADEH S. F.
Published: August 2012

In this paper, the Bremsstrahlung emission and re-absorption mechanisms are studied mainly through Inverse Bremsstrahlung and Compton Scattering. The Radiation Specific Power is calculated numerically assuming the suitable forms of Energy Distribution Function in plasma conditions. The calculation of Spectral Emission shows that, the Bremsstrahlung emission is strongly forward and backward peak relative to electron direction in overdense and high temperature plasma. Finally, some of the conditions for dominant of the re-absorption mechanism are explained.
THE CONCENTRATION PROTOCOL OF A TWO-PARTICLE NON-MAXIMALLY ENTANGLED STATE AMONG THREE CAVITIES
Authors: XU PENG , YE LIU
Published: August 2012

We propose a scheme for concentrating an arbitrary two-particle non-maximally entangled state into a maximally entangled state assisted with three cavities. The scheme involves two interaction–detection cycles and resonant interaction between atom and cavity mode. With the help of the atom trapped in the cavity, the concentration of a two-particle non-maximally entangled state trapped in separate cavities can be realized with a certain probability according to the results of photon detectors. The important feature of our scheme is that we can realize the concentration of an arbitrary two-atom non-maximally entangled state and we do not perform Bell-state measurements.
FIRST-PRINCIPLE CALCULATION OF STRUCTURAL AND ELECTRONIC PROPERTIES OF ZINC-BLENDE ByAlxGa1-x-yN MATCHED TO AlN SUBSTRATE
Authors: DJOUDI LAKHDAR , LACHEBI ABDELHADI , MERABET BOUALEM , ABID HAMZA
Published: August 2012

The full-potential linearized augmented plane wave method (FP-LAPW) within density functional theory, using the generalized gradient approximation, is used to study the structural and electronic properties of zinc-blende B y Al x Ga 1-x-y N quaternary alloys that match the lattice of an AlN substrate. The range of compositions, for which the lattice of the alloy matches AlN , is determined. Our calculated band structure, density of states, electron density and lattice parameter for B y Al x Ga 1-x-y N allow to accurately evaluate the profound effect that the incorporation of small amounts of Boron have on structural and electronic properties of Al x Ga 1-x N alloys. A comparison of the ground state properties with the available experimental and theoretical data is made for the compounds related to B y Al x Ga 1-x-y N and of the Al x Ga 1-x N alloys. The results show a strong dependence of the band gap (as well as the lattice parameter) on the Boron content, which might make B y Al x Ga 1-x-y N materials promising and useful for optoelectronic applications.
ON FREE ALGEBRAS IN VARIETIES GENERATED BY ITERATED SEMIDIRECT PRODUCTS OF SEMILATTICES
Authors: HORVÁTH GÁBOR , KÁTAI-URBÁN KAMILLA , PACH PÉTER PÁL , PLUHÁR GABRIELLA , PONGRÁCZ ANDRÁS , SZABÓ CSABA
Published: August 2012

We present a new solution of the word problem of free algebras in varieties generated by iterated semidirect products of semilattices. As a consequence, we provide asymptotical bounds for free spectra of these varieties. In particular, each finite [Formula: see text]-trivial (and, dually, each finite [Formula: see text]-trivial) semigroup has a free spectrum whose logarithm is bounded above by a polynomial function.
ON THE CONTROL OF THE MOTION OF A BOAT
Authors: GLASS OLIVIER , ROSIER LIONEL
Published: August 2012

In this paper we study the control of the motion of a boat, viewed as a rigid body S with one axis of symmetry, which is surrounded by an inviscid incompressible fluid filling ℝ2\S. We take as control input the flow of the fluid through a part of the boundary of the boat. We prove that the position, orientation, and velocity of the boat are locally controllable with a bidimensional control input, even if the flow displays some vorticity.
A DRIFT–DIFFUSION–REACTION MODEL FOR EXCITONIC PHOTOVOLTAIC BILAYERS: ASYMPTOTIC ANALYSIS AND A 2D HDG FINITE ELEMENT SCHEME
Authors: BRINKMAN DANIEL , FELLNER KLEMENS , MARKOWICH PETER A. , WOLFRAM MARIE-THERESE
Published: August 2012

We present and discuss a mathematical model for the operation of bilayer organic photovoltaic devices. Our model couples drift–diffusion–recombination equations for the charge carriers (specifically, electrons and holes) with a reaction–diffusion equation for the excitons/polaron pairs and Poisson's equation for the self-consistent electrostatic potential. The material difference (i.e. the HOMO/LUMO gap) of the two organic substrates forming the bilayer device is included as a work-function potential. Firstly, we perform an asymptotic analysis of the scaled one-dimensional stationary state system: (i) with focus on the dynamics on the interface and (ii) with the goal of simplifying the bulk dynamics away from the interface. Secondly, we present a two-dimensional hybrid discontinuous Galerkin finite element numerical scheme which is very well suited to resolve: (i) the material changes, (ii) the resulting strong variation over the interface, and (iii) the necessary upwinding in the discretization of drift–diffusion equations. Finally, we compare the numerical results with the approximating asymptotics.
HOMOGENIZATION OF ELASTIC WAVES IN FLUID-SATURATED POROUS MEDIA USING THE BIOT MODEL
Authors: MIELKE ALEXANDER , ROHAN EDUARD
Published: August 2012

We consider periodically heterogeneous fluid-saturated poroelastic media described by the Biot model with inertia effects. The weak and semistrong formulations for displacement, seepage and pressure fields involve three equations expressing the momentum and mass balance and the Darcy law. Using the two-scale homogenization method, we obtain the limit two-scale problem and prove the existence and uniqueness of its weak solutions. The Laplace transformation in time is used to decouple the macroscopic and microscopic scales. It is shown that the seepage velocity is eliminated from the macroscopic equations involving strain and pressure fields only. The plane harmonic wave propagation is studied using an example of layered medium. Illustrations show some influence of the orthotropy on the dispersion phenomena.