bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical protocols for ridge preservation after tooth extraction. A systematic review
Authors: Vignoletti Fabio , Matesanz Paula , Rodrigo Daniel , Figuero Elena , Martin Conchita , Sanz Mariano
Published: December 2011

Objective

This systematic review aims to evaluate the scientific evidence on the efficacy in the surgical protocols designed for preserving the alveolar ridge after tooth extraction and to evaluate how these techniques affect the placement of dental implants and the final implant supported restoration.

Material and methods

A thorough search in MEDLINE‐PubMed, Embase and the Cochrane Central Register of controlled trials (CENTRAL) was conducted up to February 2011. Randomized clinical trials and prospective cohort studies with a follow‐up of at least 3 months reporting changes on both the hard and soft tissues (height and/or width) of the alveolar process (mm or %) after tooth extraction were considered for inclusion.

Results

The screening of titles and abstracts resulted in 14 publications meeting the eligibility criteria. Data from nine of these 14 studies could be grouped in the meta‐analyses. Results from the meta‐analyses showed a statistically significant greater ridge reduction in bone height for control groups as compared to test groups (weighted mean differences, WMD = −1.47 mm; 95% CI [−1.982, −0.953]; P < 0.001; heterogeneity: I2 = 13.1%; χ2 P‐value = 0.314) and a significant greater reduction in bone width for control groups compared to the test groups (WMD = −1.830 mm; 95% CI [−2.947, −0.732]; P = 0.001; heterogeneity: I2 = 0%; χ2 P‐value = 0.837). Subgroup analysis was based on the surgical protocol used for the socket preservation (flapless/flapped, barrier membrane/no membrane, primary intention healing/no primary healing) and on the measurement method utilized to evaluate morphological changes. Meta‐regression analyses demonstrated a statistically significant difference favoring the flapped subgroup in terms of bone width (meta‐regression; slope = 2.26; 95% IC [1.01; 3.51]; P = 0.003).

Conclusions

The potential benefit of socket preservation therapies was demonstrated resulting in significantly less vertical and horizontal contraction of the alveolar bone crest. The scientific evidence does not provide clear guidelines in regards to the type of biomaterial, or surgical procedure, although a significant positive effect of the flapped surgery was observed. There are no data available to draw conclusions on the consequences of such benefits on the long‐term outcomes of implant therapy.
Species’ traits and environmental gradients interact to govern primary production in freshwater mussel communities
Authors: Spooner Daniel E. , Vaughn Caryn C.
Published: December 2011

We examined the effect of species identity on ecosystem function across an environmental gradient by manipulating the relative dominance of three freshwater mussel species with divergent thermal preferences in mesocosms across a temperature gradient (15, 25, 35°C). We measured a suite of individual performance (oxygen consumption, nutrient excretion) and ecosystem response metrics (community, water column, benthic gross primary production and nutrient concentrations) to determine if species performance across temperatures was governed by 1) physiological responses to temperature, 2) species interactions associated with dominant species, or 3) context‐dependent species interactions related to temperature (interaction of 1 and 2). Our results demonstrate that environmental context (temperature) combined with the functional traits of dominant species interactively influence the performance and services provided by other species, and that these shifts can have heightened effects on multiple compartments within an ecosystem. Therefore, in addition to declines in species richness, shifts in community dominance also should be considered when interpreting the effects of anthropogenic disturbances on the structure and functioning of ecosystems.
Shifts in the height‐related competitiveness of tree species following recent climate warming and implications for tree community composition: the case of common beech and sessile oak as predominant broadleaved species in Europe
Authors: Bontemps Jean‐Daniel , Herve Jean‐Christophe , Duplat Pierre , Dhôte Jean‐François
Published: December 2011

Height growth is a trait that contributes to tree species fitness. How height growth responds to environmental changes may therefore provide indications on species ability to compete and maintain, and on changes in tree community composition. Common beech Fagus sylvatica and sessile oak Quercus petraea are the predominant late‐successional broadleaved species in Europe, and they differ in their shade‐tolerance. On common beech (a shade tolerant species), recent observations across Europe have shown a growth decline during recent climate warming. Because sessile oak is a warmth‐ and light‐demanding species, we therefore hypothesised that it may gain in competitiveness relative to common beech.

We conducted analyses of historical height growth in several regions spanning the distributional range of the two species across a temperate‐continental gradient in France. Common beech and sessile oak were sampled in two and four regions, respectively, and were compared in two neighbouring regions. We documented the climatic and nutritional conditions of regional samples. Height growth of 408 trees of various ages was reconstituted from stem analyses. We estimated 20th‐century regional chronologies of height growth using a statistical modelling approach that filtered out the effects of ontogeny and site fertility. In regions where both species were sampled, modelled height trajectories were compared at different periods over the 20th century.

Growth chronologies revealed 1) long‐term growth rate increases of a magnitude of 50–100% over 100 years in both species, more acute in the continental domain, 2) recurrent historical inversions in growth fluctuations between species, 3) a recent divergence, with growth decline in common beech versus a dramatic growth increase in sessile oak, more acute in colder regions. The analysis of height trajectories indicated a recent reduction in common beech competitiveness relative to sessile oak. In the face of future climate warming, we conclude that increased prevalence of beech–oak mixtures may arise.
Microgeographic adaptation linked to forest fragmentation and habitat quality in the tropical fruit fly Drosophila birchii
Authors: Willi Yvonne , Hoffmann Ary A.
Published: December 2011

Little is known about the evolutionary implications of habitat fragmentation, although altered selection regimes could influence the genetic constitution of fragmented populations. In particular, fragmentation might lead to selection for enhanced stress resistance and tolerance of unfavorable environmental conditions. We investigated the evolutionary consequences of habitat fragmentation in Drosophila birchii flies from small fragments and the interior of large forests of northern Queensland, Australia, in three consecutive years. Evolved differences were detected in a common garden design. Flies from fragments were larger and less desiccation resistant, particularly in the first year, when they also developed faster, and had higher preadult survival under fluctuating temperatures. Furthermore, juvenile survival and adult body size were linked to a measure of habitat quality, the abundance of D. birchii in nature. The results support the hypothesis that fragmentation and habitat quality impose divergent selection. The results also bolster the conservation strategy of maintaining genetic variation for ecologically relevant traits, because persistence in fragmented habitats seems to depend on genetic variation in multiple expressed traits.
Neonatal mice do not have increased sensitivity to induction of squamous cell carcinomas
Authors: Lerche Catharina M. , Poulsen Thomas , Wulf Hans Christian
Published: December 2011

Background

Squamous cell carcinoma (SCC) is linked with the lifelong cumulative effect of ultraviolet radiation (UVR). In contrast, epidemiological data have shown that sunburn in childhood is a stronger risk factor for cutaneous malignant melanoma than continuous UVR, indicating a higher carcinogenic sensitivity early in life.

Methods

We investigated how a high neonatal dose of UVR affects the development of SCC in mice irradiated later in life. We used simulated solar radiation (sun) and solarium radiation (solarium). Ninety‐nine C3.Cg/TifBomTac‐immunocompetent hairless mice received 0, 25 or 35 standard erythema doses (SED) UVR when they were 4 days old followed by 4 SED sun or 4 SED solarium three times/weekly from 9 weeks of age.

Results

Tumours developed faster in mice treated with 35 SED UVR + 4 SED sun compared with 4 SED sun, but no change was observed in the cumulative dose required to achieve tumours. Tumours also developed faster in mice treated with 35 SED UVR + 4 SED solarium compared with 4 SED solarium, and a difference was also observed in the cumulative dose required to achieve tumours. If the Skin Cancer Utrecht‐Philadelphia‐murine spectrum was used to weigh the delivered irradiance instead of the International Commission on Illumination erythema action spectrum, tumours developed after the same accumulated dose.

Conclusion

In conclusion, this study does not indicate increased sensitivity to induction of SCC early in life.
Decentring 1788: Beyond Biotic Nativeness
Authors: HEAD LESLEY
Published: December 2011

The usefulness of the concept of biotic nativeness has been challenged in both the social and natural sciences, for different reasons. This paper explores the particular construction of nativeness in Australia in relation to plants, showing that the definition builds on and inscribes more deeply the boundary between humans and the rest of nature seen in the wider literature. In this context two further boundaries are etched: between some humans and others, and before and after European colonisation. Such a use of nativeness as an axiom of environmental management is argued to be problematic, foreclosing a number of future options just when we need to increase our capacity to deal with contingency and unpredictability. But if Australia has experienced distinctive historical processes of entrenching these boundaries, it also has a distinctive heritage of destabilisation in a range of geographic work. The paper discusses how we might build on this heritage to imagine more open futures in which the problematic boundaries were removed. Some of these futures resonate with vernacular recombinations of plants from diverse origins.
Resisting the Enforcement of Sexual Harassment Law
Authors: Tinkler Justine E.
Published: December 2011

Most people in the United States believe that sexual harassment should be illegal and that enforcement is necessary. In spite of such widespread support for antiharassment regulations, sexual harassment policy training provokes backlash and has been shown to activate traditional gender stereotypes. Using in-depth interviews and participant observations of sexual harassment policy training sessions, this study uncovers the micro-level mechanisms that underlie ambivalence about the enforcement of sexual harassment law. I find that while the different locations of men and women in the status hierarchy lead to different manifestations of resistance, gender stereotypes are used to buttress perceptions that sexual harassment laws threaten norms of interaction and status positions that men and women have an interest in maintaining. The research has implications for understanding the role of law in social change, legal compliance, and the potential/limits of law for reducing inequality.
Deconstructing hepatitis C virus infection in humanized mice
Authors: Dorner Marcus , Ploss Alexander
Published: December 2011

Hepatitis C virus is a major medical problem. Novel small‐animal models are likely to accelerate the development of more effective therapeutics and a vaccine.
Platelet‐activating Factor Does Not Mediate UVB‐induced Local Immune Suppression
Authors: Sahu Ravi P. , Yao Yongxue , Konger Raymond L. , Travers Jeffrey B.
Published: December 2011

The lipid mediator Platelet‐activating factor (PAF) and oxidized glycerophosphocholine PAF agonists produced by UVB have been demonstrated to play a pivotal role in UVB‐mediated systemic immunosuppression. Importantly, employing the ability of distant UVB irradiation to inhibit contact hypersensitivity (CHS) responses to the chemical antigen dinitrofluorobenzene (DNFB) to an area of unirradiated murine skin, we and others have demonstrated that UVB‐mediated systemic immunosuppression was only observed in PAF‐R expressing wild type (WT) mice and not in PAF‐R‐knockout (Pafr−/−) mice. As it is not known if PAF is involved in UVB‐mediated local immunosuppression, these studies compared local UVB on CHS responses in WT versus Pafr−/− mice. We demonstrate that the application of DNFB onto UVB‐exposed (locally) area of mouse skin resulted in a similar significant inhibition of subsequent CHS responses in both WT and Pafr−/− mice compared to sham‐irradiated control mice. Furthermore, the expression of langerin, a marker for the presence of Langerhans cells was substantially reduced equally in the epidermal ears of UVB‐irradiated WT and Pafr−/− mice compared to their respective sham control groups. These findings indicate that the PAF‐R is not involved UVB‐induced local immunosuppression.
Male Lower Urinary Tract Symptoms: Hypertension as a Risk Factor for Storage Symptoms, but Not Voiding Symptoms
Authors: ITO Hideaki , YOSHIYASU Takashi , YAMAGUCHI Osamu , YOKOYAMA Osamu
Published: December 2011

Objective: Both the presence of lower urinary tract symptom (LUTS) and that of hypertension (HT) increase with age. We investigated the associations between male LUTS and HT, and also whether α1‐blockers could allow for the alteration of symptoms.

Methods: The subjects comprised 10 744 men with LUTS in a multicenter Japan‐Tamsulosin International Prostate Symptom Score (IPSS) Survey to assess the long‐term effects of α1‐blockers. A total of 4828 men (mean age, 68.5 years) who received a 12‐week administration of tamsulosin (0.2 mg/day) were assessed using IPSS and quality of life (QOL) surveys before and after tamsulosin administration. Data were collected by self‐administered questionnaires including age, complete history and IPSS at the initial visit.

Results: HT was a more common comorbidity (25.9%) than diabetes mellitus (9.9%) or cardiac disease (7.2%). The presence of HT increased significantly with the degree of frequency (mild, 21%; severe, 29%) and nocturia (mild, 23%; severe, 28%), but did not increase with the degree of urgency. Tamsulosin significantly improved all storage and voiding symptoms in every age group above 40 years. The effect of tamsulosin on storage symptoms was more prominent in patients with HT than in patients without it. Concerning voiding symptoms, however, tamsulosin was as effective in patients with HT as it was in patients without HT.

Conclusion: HT represents a risk factor for the increased frequency and severity of storage symptoms and it also influences the efficacy of α1‐blockers.
Size estimation of chemical space: how big is it?
Authors: Drew Kurt L M , Baiman Hakim , Khwaounjoo Prashanna , Yu Bo , Reynisson Jóhannes
Published: December 2011

Objectives

To estimate the size of organic chemical space and its sub-regions, i.e. drug-like chemical space and known drug space (KDS).

Methods

Analysis of the growth of organic compounds as a function of their carbon atoms based on a power function (f(x) = A×B, C = x) and an exponential function (f(x) = AeBx). Also, the statistical distribution of KDS and drug-like chemical space (drugs with good oral-bioavailability) based on their carbon atom count was used to deduce their size.

Key findings

The power function (f(x) = A×B, C = x) gives a superior fit to the growth of organic compounds leading to an estimate of 3.4 × 109 populating chemical space. KDS is predicted to be 2.0 × 106 molecules and drug-like chemical space is calculated to be 1.1 × 106 compounds.

Conclusions

The values here are much smaller than previously reported. However, the numbers are large but not astronomical. A clear rationale on how we reach these numbers is given, which hopefully will lead to more refined predictions.
The CAM-LDPI method: a novel platform for the assessment of drug absorption
Authors: Tay Stephanie Li Mei , Heng Paul Wan Sia , Chan Lai Wah
Published: December 2011

Objectives

This study aimed to explore the use of the chicken chorioallantoic membrane (CAM) with laser doppler perfusion imaging (LDPI) as a platform to assess absorption of vasoactive drugs.

Methods

The optimal age of the CAM to be employed in the test and the indicator of vasoactivity were first established. Test substances that included common solvents and vasoactive drugs were tested on the CAM surface to determine their irritancy and blood perfusion effects.

Key Findings

Insignificant changes in blood perfusion were observed with deionized water, 0.9% w/v soldium chloride and 5% w/v glucose monohydrate, as well as theophylline and glucagon. Complex changes in blood perfusion were detected with ethanol, N-methyl-2-pyrrolidone, glycerin and propranolol. Both caffeine and glyceryl trinitrate resulted in a drop in blood perfusion.

Conclusions

It was concluded that the LDPI offers a rapid and non-invasive method to measure blood perfusion in the CAM. The latter provides a potentially useful platform in formulation studies to evaluate the effects of additives on drug absorption using caffeine or glyceryl trinitrate as model drugs.
Integrated Control of Rotating Stall and Surge in High-Speed Multistage Compression Systems
Authors: Eveker K. M. , Gysling D. L. , Nett C. N. , Sharma O. P.
Published: December 2011

Aeroengines operate in regimes for which both rotating stall and surge impose low-flow operability limits. Thus, active control strategies designed to enhance operability of aeroengines must address both rotating stall and surge as well as their interaction. In this paper, a previously developed nonlinear control strategy that achieves simultaneous active control of rotating stall and surge is applied to a high-speed three-stage axial flow compression system with operating parameters representative of modern aeroengines. The controller is experimentally validated for two compressor builds and its robustness to radial distortion assessed. For actuation, the control strategy utilizes an annulus-averaged bleed valve with bandwidth on the order of the rotor frequency. For sensing, measurements of the circumferential asymmetry and annulus-averaged unsteadiness of the flow through the compressor are used. Experimental validation of simultaneous control of rotating stall and surge in a high-speed environment with minimal sensing and actuation requirements is viewed as another important step toward applying active control to enhance operability of compression systems in modern aeroengines.
The Performance of a Centrifugal Compressor With High Inlet Prewhirl
Authors: Whitfield A. , Abdullah A. H.
Published: December 2011

The performance requirements of centrifugal compressors usually include a broad operating range between surge and choke. This becomes increasingly difficult to achieve as increased pressure ratio is demanded. In order to suppress the tendency to surge and extend the operating range at low flow rates, inlet swirl is often considered through the application of inlet guide vanes. To generate high inlet swirl angles efficiently, an inlet volute has been applied as the swirl generator, and a variable geometry design developed in order to provide zero swirl. The variable geometry approach can be applied to increase the swirl progressively or to switch rapidly from zero swirl to maximum swirl. The variable geometry volute and the swirl conditions generated are described. The performance of a small centrifugal compressor is presented for a wide range of inlet swirl angles. In addition to the basic performance characteristics of the compressor, the onsets of flow reversals at impeller inlet are presented, together with the development of pressure pulsations, in the inlet and discharge ducts, through to full surge. The flow rate at which surge occurred was shown, by the shift of the peak pressure condition and by the measurement of the pressure pulsations, to be reduced by over 40 percent.
Adiabatic Wall Effectiveness Measurements of Film-Cooling Holes With Expanded Exits
Authors: Gritsch M. , Schulz A. , Wittig S.
Published: December 2011

This paper presents detailed measurements of the film-cooling effectiveness for three single, scaled-up film-cooling hole geometries. The hole geometries investigated include a cylindrical hole and two holes with a diffuser-shaped exit portion (i.e., a fan-shaped and a laid-back fan-shaped hole). The flow conditions considered are the crossflow Mach number at the hole entrance side (up to 0.6), the crossflow Mach number at the hole exit side (up to 1.2), and the blowing ratio (up to 2). The coolant-to-mainflow temperature ratio is kept constant at 0.54. The measurements are performed by means of an infrared camera system, which provides a two-dimensional distribution of the film-cooling effectiveness in the near field of the cooling hole down to x/D = 10. As compared to the cylindrical hole, both expanded holes show significantly improved thermal protection of the surface downstream of the ejection location, particularly at high blowing ratios. The laidback fan-shaped hole provides a better lateral spreading of the ejected coolant than the fan-shaped hole, which leads to higher laterally averaged film-cooling effectiveness. Coolant passage cross-flow Mach number and orientation strongly affect the flowfield of the jet being ejected from the hole and, therefore, have an important impact on film-cooling performance.
Detection and Identification of Faults in NPP Instruments Using Kernel Principal Component Analysis
Authors: Ma Jianping , Jiang Jin
Published: December 2011

In this paper, kernel principal component analysis (KPCA) is studied for fault detection and identification of the instruments in nuclear power plants. A KPCA model for fault isolation and identification is proposed by using the average sensor reconstruction errors. Based on this model, faults in multiple sensors can be isolated and identified simultaneously. Performance of the KPCA-based method is demonstrated with real NPP measurements.
Modeling and Control Analysis of a 3-PUPU Dual Compliant Parallel Manipulator for Micro Positioning and Active Vibration Isolation
Authors: Yun Y. , Li Y.
Published: December 2011

In recent years, many applications in precision engineering require a careful isolation of the instrument from the vibration sources by adopting active vibration isolation system to achieve a very low remaining vibration level, especially for the very low frequency under 10 Hz vibration signals. This paper presents a 3-PUPU dual parallel manipulator for both rough positioning and active vibration isolation in a wide-range workspace based on our previous research experiences in the systematical modeling and study of parallel robots. The manipulator is designed as a kind of macro/micro hybrid robot. Both the kinematics model for macro motion and dynamics model for micro motion are established by using stiffness equation and the Kane’s method, respectively. An active vibration control strategy is described by using the H2 method. Moreover, numerical simulations on the inverse solution for macro motion, workspace, and the active vibration control effects are performed at the end of this paper.
Exhaust Pressure Estimation and Its Application to Detection and Isolation of Turbocharger System Faults for Internal Combustion Engines
Authors: Wang Yue-Yun , Haskara Ibrahim
Published: December 2011

Engine exhaust backpressure is a critical parameter in the calculation of the volumetric efficiency and exhaust gas recirculation flow of an internal combustion engine. The backpressure also needs to be controlled to a presetting limit under high speed and load engine operating conditions to avoid damaging a turbocharger. In this paper, a method is developed to estimate exhaust pressure for internal combustion engines equipped with variable geometry turbochargers. The method uses a model-based approach that applies a coordinate transformation to generate a turbine map for the estimation of exhaust pressure. This estimation can substitute for an expensive pressure sensor, thus saving significant cost for production vehicles. On the other hand, for internal combustion engines that have already installed exhaust pressure sensors, this estimation can be used to generate residual signals for model-based diagnostics. Cumulative sum algorithms are applied to residuals based on multiple sensor fusion, and with the help of signal processing, the algorithms are able to detect and isolate critical failure modes of a turbocharger system.
Effects of Pretreating Serum Samples on the Performance of a Latex Agglutination Test for Serodiagnosis of Paracoccidioidomycosis
Authors: Silveira-Gomes Fabíola , Marques-da-Silva Silvia Helena
Published: December 2011

Paracoccidioidomycosis (PCM) is a fungal disease caused byParacoccidioides brasiliensis, and Brazil is one of the principal countries where it is endemic. Diagnosis is based on the observation of buddingP. brasiliensisyeast in clinical specimens from patients; however, the sensitivity of the visualization of fungi is low, indicating that serological tests are used for early diagnosis. The double-immunodiffusion test (ID) is the “gold standard” test for serology in PCM, although the execution of this test requires the availability of laboratorial infrastructure. We report the improved performance of a latex agglutination test (LAT) by pretreating 30 serum samples from PCM patients and 71 controls (histoplasmosis and aspergillosis patients, patients with bacterial infections, and normal human sera) with a dilution buffer incubated at 37°C for 30 min. The sensitivity and specificity of the LAT test in the nonpretreated samples were 73% and 79%, respectively. However, when samples were pretreated, the sensitivity and specificity of the test increased to 90%. In this study, we did not observe cross-reactivity with histoplasmosis patient sera, but some reactions to sera from patients with aspergillosis and bacterial infections were noted. Normal human sera were not reactive in our tests. These results indicate the need for the elimination of heterologous reactions so that we can adequately use this method for screening cases of PCM.
Draft Genome Sequence of Leucobacter chromiiresistens, an Extremely Chromium-Tolerant Strain
Authors: Sturm Gunnar , Buchta Karl , Kurz Thorsten , Rensing Stefan A. , Gescher Johannes
Published: December 2011

Here we present the draft genome of
Leucobacter chromiiresistens
. This is the first genome sequence of an organism belonging to the genus
Leucobacter
.
L. chromiiresistens
was sequenced due to its capability to tolerate up to 300 mM Cr(VI) in the medium, which is so far a unique feature for microorganisms.
Complete Genome Sequence of the BTEX-Degrading Bacterium Pseudoxanthomonas spadix BD-a59
Authors: Lee Seung Hyeon , Jin Hyun Mi , Lee Hyo Jung , Kim Jeong Myeong , Jeon Che Ok
Published: December 2011

Pseudoxanthomonas spadix
BD-a59, able to metabolize all six BTEX (benzene, toluene, ethylbenzene, and
o
-,
m
-, and
p
-xylene) compounds, was isolated from gasoline-contaminated sediment. Here, we report the complete 3.45-Mb genome sequence and annotation of strain BD-a59. These advance the understanding of strain BD-a59's genomic properties and pollutant metabolic versatility.
Thymidine Auxotrophic Staphylococcus aureus Small-Colony Variant Endocarditis and Left Ventricular Assist Device Infection
Authors: Maduka-Ezeh Awele , Seville Maria Teresa , Kusne Shimon , Vikram Holenarasipur R. , Blair Janis E. , Greenwood-Quaintance Kerryl , Arabia Francisco , Patel Robin
Published: December 2011

We describe a thymidine-dependent small-colony variant ofStaphylococcus aureusassociated with left ventricular assist device infection and prosthetic valve and pacemaker endocarditis.
Differences in Methicillin-Resistant Staphylococcus aureus Strains Isolated from Pediatric and Adult Patients from Hospitals in a Large County in California
Authors: Hudson Lyndsey O. , Murphy Courtney R. , Spratt Brian G. , Enright Mark C. , Terpstra Leah , Gombosev Adrijana , Hannah Paul , Mikhail Lydia , Alexander Richard , Moore Douglas F. , Huang Susan S.
Published: December 2011

Studies of U.S. epidemics of community- and health care-associated methicillin-resistant
Staphylococcus aureus
(MRSA) suggested differences in MRSA strains in adults and those in children. Comprehensive population-based studies exploring these differences are lacking. We conducted a prospective cohort study of inpatients in Orange County, CA, collecting clinical MRSA isolates from 30 of 31 Orange County hospitals, to characterize differences in MRSA strains isolated from children compared to those isolated from adults. All isolates were characterized by
spa
typing. We collected 1,124 MRSA isolates from adults and 159 from children. Annual Orange County population estimates of MRSA inpatient clinical cultures were 119/100,000 adults and 22/100,000 children.
spa
types t008, t242, and t002 accounted for 83% of all isolates. The distribution of these three
spa
types among adults was significantly different from that among children (χ
2
= 52.29;
P
< 0.001). Forty-one percent of adult isolates were of t008 (USA300), compared to 69% of pediatric isolates. In multivariate analyses, specimens from pediatric patients, wounds, non-intensive care unit (ICU) wards, and hospitals with a high proportion of Medicaid-insured patients were significantly associated with the detection of t008 strains. While community- and health care-associated MRSA reservoirs have begun to merge, significant differences remain in pediatric and adult patient populations. Community-associated MRSA
spa
type t008 is significantly more common in pediatric patients.
Evidence of Diversity among Epidemiologically Related Carbapenemase-Producing Acinetobacter baumannii Strains Belonging to International Clonal Lineage II
Authors: Minandri Fabrizia , D'Arezzo Silvia , Antunes Luísa C. S. , Pourcel Christine , Principe Luigi , Petrosillo Nicola , Visca Paolo
Published: December 2011

Carbapenem-resistant
Acinetobacter baumannii
strains belonging to international clonal lineage II (ICL-II) have become predominant in intensive care units (ICUs) throughout Italy. Between 2005 and 2009, the carbapenem-hydrolyzing class D β-lactamase (CHDL)
bla
OXA-23
gene became more prevalent than
bla
OXA-58
among epidemic ICL-II strains showing extensive genetic similarity. These findings posed the question of whether CHDL gene replacement occurred in the homogeneous ICL-II population or a new OXA-23 clone(s) emerged and spread in ICUs. In this study, the changes in the ICL-II
A. baumannii
population and CHDL gene carriage were investigated in 30 genetically related isolates collected during the
bla
OXA-58
-to-
bla
OXA-23
transition period. Pulsotyping, randomly amplified polymorphic DNA (RAPD) analysis, and multilocus sequence typing (MLST) results were combined with multilocus variable-number tandem-repeat (VNTR) analysis (MLVA-8), siderotyping, and plasmid profiling to improve genotype-based discrimination between isolates. Pulsotyping, RAPD analysis, and MLST clustered isolates into a single type. MLVA-8 identified 19 types that clustered into three complexes. All OXA-23-producing isolates formed a single complex, while OXA-58 producers were split into two complexes. Southern blot analysis of the physical localization and genetic context of the CHDL genes showed that
bla
OXA-58
was invariably located on plasmids, while
bla
OXA-23
was present within Tn
2006
on the chromosome or both the chromosome and plasmids. These data indicate that the apparently homogeneous population of CHDL-producing ICL-II strains was composed of several independent strains and that, between 2005 and 2009, distinct OXA-23 producers displaced the preexisting OXA-58 producers. Thus, MLVA-8 appears to be a suitable tool not only for investigating
A. baumannii
population structure but also for high-resolution epidemiological typing.
Pooling Nasopharyngeal/Throat Swab Specimens To Increase Testing Capacity for Influenza Viruses by PCR
Authors: Van Tam T. , Miller Joseph , Warshauer David M. , Reisdorf Erik , Jernigan Daniel , Humes Rosemary , Shult Peter A.
Published: December 2011

Real-time PCR methodology can be applied to rapidly and accurately detect influenza viruses. During times of surge testing or enhanced pandemic surveillance, public health laboratories (PHLs) may experience overwhelming demand for testing, even while the prevalence of positive specimens remains low. To improve laboratory capacity and testing efficiency during surges, we evaluated whether nasopharyngeal (NP)/throat swab specimens can be pooled and tested for the presence of the 2009 H1N1 influenza virus without a reduction in sensitivity. Pools of 10 specimens were extracted and concentrated upon elution on the MagNA Pure LC instrument, and real-time PCR was performed on the Applied Biosystems 7500 Fast platform, using the CDC swine influenza virus real-time RT-PCR detection panel (rRT-PCR swine flu panel). Specimens in positive pools were singly re-extracted and retested by PCR to identify individual positive samples. Initial studies showed that spiking a pool of nine negative specimens (100 μl each) or 900 μl of virus transport medium with 100 μl of a positive clinical specimen caused no loss of sensitivity by rRT-PCR testing. Pools containing either multiple positive specimens or specimens positive for other respiratory viruses also showed no negative effect on crossing threshold (
C
T
) values. To test the robustness of the pooling protocol, a panel of 50 blinded samples was sent to three PHLs and tested in five pools of 10. All PHLs correctly identified the positive specimens. This study demonstrates the feasibility of using a pooling strategy to increase capacity and conserve resources during surge testing and periods of enhanced influenza surveillance when the prevalence is low.
Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry-Based Functional Assay for Rapid Detection of Resistance against β-Lactam Antibiotics
Authors: Sparbier Katrin , Schubert Sören , Weller Ulrich , Boogen Christiane , Kostrzewa Markus
Published: December 2011

Resistance against β-lactam antibiotics is a growing challenge for managing severe bacterial infections. The rapid and cost-efficient determination of β-lactam resistance is an important prerequisite for the choice of an adequate antibiotic therapy. β-Lactam resistance is based mainly on the expression/overexpression of β-lactamases, which destroy the central β-lactam ring of these drugs by hydrolysis. Hydrolysis corresponds to a mass shift of +18 Da, which can be easily detected by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Therefore, a MALDI-TOF MS-based assay was set up to investigate different enterobacteria for resistance against different β-lactam antibiotics: ampicillin, piperacillin, cefotaxime, ceftazidime, ertapenem, imipenem, and meropenem. β-Lactamases are enzymes that have a high turnover rate. Therefore, hydrolysis can be detected by MALDI-TOF MS already after a few hours of incubation of the bacteria to be tested with the given antibiotic. The comparison of the MS-derived data with the data from the routine procedure revealed identical classification of the bacteria according to sensitivity and resistance. The MALDI-TOF MS-based assay delivers the results on the same day. The approved routine procedures require at least an additional overnight incubation.
Individual Plasmodium vivax
msp1
Variants within Polyclonal P. vivax Infections Display Different Propensities for Relapse
Authors: Lin Jessica T. , Juliano Jonathan J. , Kharabora Oksana , Sem Rithy , Lin Feng-Chang , Muth Sinuon , Ménard Didier , Wongsrichanalai Chansuda , Rogers William O. , Meshnick Steven R.
Published: December 2011

Using a newly developed
Plasmodium vivax
merozoite surface protein 1 gene (
Pvmsp1
) heteroduplex tracking assay, we genotyped 107
P. vivax
infections in individuals from Cambodia, 45 of whom developed recurrent parasitemia within 42 days. The majority of isolates were polyclonal, but recurrent parasitemias displayed fewer variants compared to initial parasitemias. Two
Pvmsp1
gene variants occurred more frequently in the initial genotypes of those who developed recurrent parasitemia, representing the first time
P. vivax
variants associated with a higher risk of relapse have been described.
Self-Assembly of Viral Capsid Protein and RNA Molecules of Different Sizes: Requirement for a Specific High Protein/RNA Mass Ratio
Authors: Cadena-Nava Ruben D. , Comas-Garcia Mauricio , Garmann Rees F. , Rao A. L. N. , Knobler Charles M. , Gelbart William M.
Published: December 2011

Virus-like particles can be formed by self-assembly of capsid protein (CP) with RNA molecules of increasing length. If the protein “insisted” on a single radius of curvature, the capsids would be identical in size, independent of RNA length. However, there would be a limit to length of the RNA, and one would not expect RNA much shorter than native viral RNA to be packaged unless multiple copies were packaged. On the other hand, if the protein did not favor predetermined capsid size, one would expect the capsid diameter to increase with increase in RNA length. Here we examine the self-assembly of CP from cowpea chlorotic mottle virus with RNA molecules ranging in length from 140 to 12,000 nucleotides (nt). Each of these RNAs is completely packaged if and only if the protein/RNA mass ratio is sufficiently high; this critical value is the same for all of the RNAs and corresponds to equal RNA and N-terminal-protein charges in the assembly mix. For RNAs much shorter in length than the 3,000 nt of the viral RNA, two or more molecules are assembled into 24- and 26-nm-diameter capsids, whereas for much longer RNAs (>4,500 nt), a single RNA molecule is shared/packaged by two or more capsids with diameters as large as 30 nm. For intermediate lengths, a single RNA is assembled into 26-nm-diameter capsids, the size associated with T=3 wild-type virus. The significance of these assembly results is discussed in relation to likely factors that maintain T=3 symmetry
in vivo
.
FINITE TIME BLOW-UP FOR THE NONLINEAR FOURTH-ORDER DISPERSIVE-DISSIPATIVE WAVE EQUATION AT HIGH ENERGY LEVEL
Authors: XU RUNZHANG , YANG YANBING
Published: December 2011

In this paper, we investigate the initial boundary value problem of the nonlinear fourth-order dispersive-dissipative wave equation. By using the concavity method, we establish a blow-up result for certain solutions with arbitrary positive initial energy.
Chronic hypoxia upregulates pulmonary arterial ASIC1: a novel mechanism of enhanced store-operated Ca2+ entry and receptor-dependent vasoconstriction
Authors: Jernigan Nikki L. , Herbert Lindsay M. , Walker Benjimen R. , Resta Thomas C.
Published: December 2011

Acid-sensing ion channel 1 (ASIC1) is a newly characterized contributor to store-operated Ca2+ entry (SOCE) in pulmonary vascular smooth muscle (VSM). Since SOCE is implicated in elevated basal VSM intracellular Ca2+ concentration ([Ca2+]i) and augmented vasoconstriction in chronic hypoxia (CH)-induced pulmonary hypertension, we hypothesized that ASIC1 contributes to these responses. To test this hypothesis, we examined effects of the specific pharmacologic ASIC1a inhibitor, psalmotoxin 1 (PcTX1), on vasoconstrictor and vessel wall [Ca2+]i responses to UTP and KCl (depolarizing stimulus) in fura-2-loaded, pressurized small pulmonary arteries from control and CH (4 wk at 0.5 atm) Wistar rats. PcTX1 had no effect on basal vessel wall [Ca2+]i, but attenuated vasoconstriction and increases in vessel wall [Ca2+]i to UTP in arteries from control and CH rats; normalizing responses between groups. In contrast, responses to the depolarizing stimulus, KCl, were unaffected by CH exposure or PcTX1. Upon examining potential Ca2+ influx mechanisms, we found that PcTX1 prevented augmented SOCE following CH. Exposure to CH resulted in a significant increase in pulmonary arterial ASIC1 protein. This study supports a novel role of ASIC1 in elevated receptor-stimulated vasoconstriction following CH which is likely mediated through increased ASIC1 expression and SOCE.
Hardy operator with variable limits on monotone functions
Authors: Stepanov Vladimir D. , Ushakova Elena P.
Published: December 2011

We characterize weighted Lp − Lq inequalities with the Hardy operator of the form with a non‐negative weight function u, restricted to the cone of monotone functions on the semiaxis. The proof is based on the Sawyer criterion and the boundedness of generalized Hardy operator with variable limits.
lp,q‐bounded sequences in function spaces
Authors: Novikov S. Ya.
Published: December 2011

A sequence of measurable functions {fn} is called lp,q‐bounded sequence, 0 < p < ∞,   0 < q ≤ ∞, if for any sequence of real numbers a = {αn} ∈ lp,q we have ., for any sequence {Fn} such that for every n functions fn anf Fn are equimeasurable. The main result gives necessary and sufficient conditions for the sequence being lp,q‐bounded.
A new proof of Donoghue′s interpolation theorem
Authors: Ameur Yacin
Published: December 2011

We give a new proof and new interpretation of Donoghue′s interpolation theorem; for an intermediate Hilbert space H∗ to be exact interpolation with respect to a regular Hilbert couple it is necessary and sufficient that the norm in H∗ be representable in the form with some positive Radon measure ρ on the compactified half‐line [0, ∞]. The result was re‐proved in [1] in the finite‐dimensional case. The purpose of this note is to extend the proof given in [1] to cover the infinite‐dimensional case. Moreover, the presentation of the aforementioned proof in [1] was slightly flawed, because we forgot to include a reference to ‘Donoghue′s Lemma’, which is implicitly used in the proof. Hence we take this opportunity to correct that flaw.
Quantitative functional calculus in Sobolev spaces
Authors: Morosi Carlo , Pizzocchero Livio
Published: December 2011

In the frame work of Sobolev (Bessel potential) spaces Hn(Rd, R or C), we consider the nonlinear Nemytskij operator sending a function x ∈ Rd ↦ f(x) into a composite function x ∈ Rd ↦ G(f(x), x). Assuming sufficient smoothness for G, we give a “tame” bound on the Hn norm of this composite function in terms of a linear function of the Hn norm of f, with a coefficient depending on G and on the Ha norm of f, for all integers n, a, d with a > d/2. In comparison with previous results on this subject, our bound is fully explicit, allowing to estimate quantitatively the Hn norm of the function x ↦ G(f(x), x). When applied to the case G(f(x), x) = f2(x), this bound agrees with a previous result of ours on the pointwise product of functions in Sobolev spaces.
New frames of Besov and Triebel‐Lizorkin spaces
Authors: Yang Dachun
Published: December 2011

Let s≺0. The author obtains some new frames for Besov spaces with 1 ≤ p, q ≤ ∞ and Triebel‐Lizorkin spaces with 1≺p≺∞ and 1≺q ≤ ∞ by a dual method via the subatomic characterizations of these spaces when s≻0.
Equivalent norms of Herz‐type Besov and Triebel‐Lizorkin spaces
Authors: Xu Jingshi
Published: December 2011

In this paper the author obtains equivalent norms of Herz‐type Besov and Triebel‐Lizorkin spaces, which are generalizations of well‐known Herz‐type spaces and inhomogeneous Besov and Triebel‐Lizorkin spaces.
Traces of multipliers in pairs of weighted Sobolev spaces
Authors: Maz′ya Vladimir , Shaposhnikova Tatyana
Published: December 2011

We prove that the pointwise multipliers acting in a pair of fractional Sobolev spaces form the space of boundary traces of multipliers in a pair of weighted Sobolev space of functions in a domain.
Two‐scale convergence with respect to measures and homogenization of monotone operators
Authors: Lukkassen Dag , Wall Peter
Published: December 2011

In 1989 Nguetseng introduced two‐scale convergence, which now is a frequently used tool in homogenization of partial differential operators. In this paper we discuss the notion of two‐scale convergence with respect to measures. We make an exposition of the basic facts of this theory and develope it in various ways. In particular, we consider both variable Lp spaces and variable Sobolev spaces. Moreover, we apply the results to a homogenization problem connected to a class of monotone operators.
Box dimension, oscillation and smoothness in function spaces
Authors: Carvalho Abel
Published: December 2011

The aim of this paper is twofold. First we relate upper and lower box dimensions with oscillation spaces, and we develop embeddings or inclusions between oscillation spaces and Besov spaces. Secondly, given a point in the (, s)‐plane we determine maximal and minimal values for the upper box dimension (also the maximal value for lower box dimension) for the graphs of continuous real functions with a compact support, represented by this point.
N‐harmonic extensions of weighted integrable distributions
Authors: Alvarez Josefina , Guzmán-Partida Martha , Pérez-Esteva Salvador
Published: December 2011

We obtain n‐harmonic extensions to the Cartesian product of ncopies of the upper half‐plane, of distributions in the weighted space , which is known to be the optimal space of tempered distributions that are ‐convolvable with a natural product domain version of the Poisson kernel.
Non‐equivalent greedy and almost greedy bases in lp
Authors: Dilworth Stephen J. , Hoffmann Mark , Kutzarova Denka N.
Published: December 2011

For 1 < p < 8 and p ? 2 we construct a family of mutually non‐equivalent greedy bases in lp having the cardinality of the continuum. In fact, no basis from this family is equivalent to a rearranged subsequence of any other basis thereof. We are able to extend this statement to the spaces Lp and H1. Moreover, the technique used in the proof adapts to the setting of almost greedy bases where similar results are obtained.
[Retracted] Nonlinear eigenvalue problems in Sobolev spaces with variable exponent
Authors: Dinu Teodora-Liliana
Published: December 2011

We study the boundary value problem −div?((|?u|p1(x)−2 + |?u|p2(x)−2)?u) = f(x, u) in O, u = 0 on ?O, where O is a smooth bounded domain in RN. We focus on the cases when f±(x, ??u) = ±(−?|u|m(x)−2u + |u|q(x)−2u), where for any . In the first case we show the existence of infinitely many weak solutions for any ? > 0. In the second case we prove that if ? is large enough then there exists a nontrivial weak solution. Our approach relies on the variable exponent theory of generalized Lebesgue‐Sobolev spaces, combined with a Z2‐symmetric version for even functionals of the Mountain Pass Lemma and some adequate variational methods.
New proof of Nagnibida′s theorem
Authors: Karaev Mubariz T.
Published: December 2011

Using the Duhamel product for holomorphic functions we give a new proof of Nagnibida’s theorem on unicellularity of integration operator , acting in the space .
QK type spaces of analytic functions
Authors: Wulan Hasi , Zhou Jizhen
Published: December 2011

For a nondecreasing function K : [0, 8)?[0, 8) and 0 < p < 8, −2 < q < 8, we introduce QK(p, q), a QK type space of functions analytic in the unit disk and study the characterizations of QK(p, q). Necessary and sufficient conditions on K such that QK(p, q) become some known spaces are given.
Optimal codomains for the Laplace operator and the product Laplace operator
Authors: Alvarez Josefina , S. Moyo Lloyd Edgar
Published: December 2011

An optimal codomain for an operator P (∂) with fundamental solution E, is a maximal space of distributions T for which it is possible to define the convolution E*T and thus to solve the equation P (∂)S = T. We identify optimal codomains for the Laplace operator in the Euclidean case and for the product Laplace operator in the product domain case. The convolution is understood in the sense of the S′‐convolution.