bluuebunny/crossref_metadata_2025 huggingface dataset:
Light pulse propagation in disordered thin films and mode selection for random lasers
Authors: Li Sheng , Wang Shuai , Sun Xin , Wang Zi-Jun , George Thomas F.
Published: March 2006

When a wide-gap semiconductor polycrystalline film is pumped by a pulsed laser, a special light pulse can be generated. During the propagation of this pulse, strong multiple scattering not only traps coherent and localized modes inside the sample, but also leaks noncoherent extensive modes outside. As the gain of the external laser pulse approaches a critical threshold value, the leaked energy, which is caused by noncoherent extensive modes, can be counteracted to drive the photons into a localized mode. Once the external gain surpasses the critical value, the localized mode serves as a laser mode to emit coherent radiation.
Wide operation margin of toggle mode switching for magnetic random access memory with preceding negative pulse writing scheme
Authors: Hung Chien-Chung , Lee Yuan-Jen , Kao Ming-Jer , Wang Yung-Hung , Huang Rei-Fu , Chen Wei-Chuan , Chen Young-Shying , Shen Kuei-Hung , Tsai Ming-Jinn , Lin Wen-Chin , Tang Denny Duan-Lee , Chao Shiuh
Published: March 2006

In this work, a writing scheme with preceding negative pulse wave form for toggle magnetic random access memory (MRAM) is proposed to enhance the switching yield and enable a low current switching. The failure mechanism of toggle switching is studied by micromagnetic analysis. As a result of broadened operation window and reduced switching current, the scalability of MRAM is feasible with the robust toggle operation.
Reversible thermochromic effects in poly(phenylene vinylene)-based polymers
Authors: Leger J. M. , Holt A. L. , Carter S. A.
Published: March 2006

We study the thermochromic response of poly [2-methoxy-5-(2 -ethylhexyloxy)-1,4-phenylenevinylene] (PPV) gel films. These films undergo a reversible, continuous color change from red to yellow in the practically relevant temperature range of 25–100°C. We show that the absorption and photoluminescence continuously decrease and blueshift along with an increase in both highest occupied molecular orbital and lowest unoccupied molecular orbital levels as the temperature is increased, and that this effect does not depend on glass transition temperature. Understanding the changes in this widely used, versatile class of materials at elevated temperatures is important in controlling the operation of polymer photovoltaics and has implications in the fundamental factors affecting emission color in PPV based materials.
Carbon nanotube field-effect transistor operation at microwave frequencies
Authors: Pesetski Aaron A. , Baumgardner James E. , Folk Erica , Przybysz John X. , Adam John D. , Zhang Hong
Published: March 2006

A top-gated carbon nanotube (CNT) field-effect transistor (FET) was fabricated on a quartz substrate. We used a novel measurement approach and demonstrated for the first time frequency-independent performance of a CNT FET for frequencies as high as 23GHz. This observed maximum operating frequency represents a significant breakthrough in the realization of carbon nanotube-based electronics for high frequency applications.
Fabrication of clean carbon nanotube field emitters
Authors: Hahn Joeoong , Jung Sung Mi , Jung Hyun Young , Heo Soo Bong , Shin Ji Hye , Suh Jung Sang
Published: March 2006

We have developed a method for fabricating a good carbon nanotube (CNT) field emitter using electrophoretic deposition and fissure formation techniques. A thin film of CNTs was deposited on a Ti substrate, by electrophoresis, from an aqueous mixture of CNT and detergent, dried naturally, and then pressed on the surface to make it smooth. By firing, it was changed to numerous microsized islands. As a result very clean CNT tips were generated from the fissures formed. The film showed good field emission properties. Our method affords a process of simple steps and does not need any postdeposition or activation process for field emission.
Comparison of medium-vacuum and plasma-activated low-temperature wafer bonding
Authors: Tan Cher Ming , Yu Weibo , Wei Jun
Published: March 2006

Two low-temperature wafer bonding methods, namely the medium-vacuum level wafer bonding (MVWB) and plasma-activated wafer bonding (PAWB), are performed. After low-temperature annealing (500°C) for a short time (<5h), the bond strength of these two low-temperature methods is improved as compared to the conventional air wafer bonding. The bond efficiency of MVWB is found to be better than the conventional air wafer bonding, but PAWB contains more bubbles. The qualitative mechanisms of these two low-temperature wafer bonding methods are proposed.
Nature of the abnormal band gap narrowing in highly crystalline Zn1−xCoxO nanorods
Authors: Qiu Xiaoqing , Li Liping , Li Guangshe
Published: March 2006

Highly crystalline Zn1−xCoxO nanorods were prepared using a hydrothermal method. With increasing Co2+ dopant concentration, the lattice volume enlarged considerably, which is associated with the enhanced repulsive interactions of defect dipole moments on the wall surfaces. This lattice modification produced a significant decrease in band gap energies with its magnitude that followed the relationship, ΔEg=ΔE0∙(e−xB−1), where x and B are Co2+ dopant concentration and a constant, respectively. The abnormal band gap energies were indicated to originate from the sp-d exchange interactions that are proportional to the square of lattice volume.
Low-frequency noise statistics for the breakdown characterization of ultrathin gate oxides
Authors: Butt N. Z. , Chang A. M. , Raza H. , Bashir R. , Liu J. , Kwong D. L.
Published: March 2006

We have investigated the statistics of low-frequency noise in the tunneling current of ultrathin oxides (2.5–4nm) in metal-oxide-semiconductor capacitors as a function of the applied voltage stress. The statistical analysis includes (i) non-Gaussianity (nG), which is a measure of the degree of temporal correlation in the noise, and (ii) ratio of integrated noise power to the dc leakage current (R). The occurrence of high peaks in nG indicates the appearance of new percolation paths, and the subsequent conduction through these paths is indicated by R. Our results show that the nG and R characteristics are generic for the oxides of different thickness and growth quality and have the potential, in conjunction with leakage itself, of being used as a prognosticator of oxide reliability.
Investigation of Ta film growth mechanisms and atomic structures on polymer and SiC amorphous substrates
Authors: Yang Shuo-Wang , Dai Ling , Chen Xian-Tong , Wu Ping , Tan V. B. C.
Published: March 2006

Large scale ab initio molecular dynamics simulations were undertaken to study the entire process of sputtering deposition of Ta atoms and Ta film formation on two different substrates, a low-k polymer and amorphous SiC. The calculation results gave insights into the Ta film growth mechanisms and their atomic ordering configurations on these substrates. Their effectiveness in blocking Cu diffusion was also investigated. Reasons for experimental observations of poor and good diffusion-barrier performances of Ta-polymer and Ta-SiC dielectric systems, respectively, were revealed from the simulations.
Effects of iron additions on filament growth and productivity of the cyanobacterium Lyngbya majuscula
Authors: Ahern Kathleen S. , O'Neil Judith M. , Udy James W. , Albert Simon
Published: March 2006

The bioavailability of iron, in combination with essential macronutrients such as phosphorus, has been hypothesised to be linked to nuisance blooms of the toxic cyanobacterium Lyngbya majuscula. The present laboratory study used two biological assay techniques to test whether various concentrations of added iron (inorganic and organically chelated) enhanced L. majuscula filament growth and productivity (14C-bicarbonate uptake rate). Organically chelated iron (FeEDTA) with adequate background concentrations of phosphorus and molybdenum caused the largest increases (up to 4.5 times the control) in L. majuscula productivity and filament growth. The addition of inorganic iron (without added phosphorus or molybdenum) also stimulated L. majuscula filament growth. However, overall the FeEDTA was substantially and significantly more effective in promoting L. majuscula growth than inorganic iron (FeCl3). The organic chelator (EDTA) alone and molybdenum alone also enhanced L. majuscula growth but to a lesser extent than the chelated iron. The results of the present laboratory study support the hypothesis that iron and chelating organic compounds may be important in promoting blooms of L. majuscula in coastal waters of Queensland, Australia.
Age, growth, maturity, longevity and natural mortality of the shortfin mako shark (Isurus oxyrinchus) in New Zealand waters
Authors: Bishop S. D. H. , Francis M. P. , Duffy C. , Montgomery J. C.
Published: March 2006

Shortfin mako sharks were aged by counting growth bands in sectioned vertebrae (n = 256), and assuming annual band-pair deposition. No systematic ageing bias was present and count precision was high. 0+ juveniles were identified from length–frequency plots and assigned ages based on a theoretical birth date of 1 October and their date of capture. A Schnute generalised growth model fitted to the combined vertebral and 0+ data described the growth patterns best. Shortfin makos grow very rapidly initially, increasing by ~39 cm fork length in their first year. Thereafter, males and females grow at similar but slower rates until about age 7 years, after which the relative growth of males declines. Longevity estimates were 29 and 28 years for males and females respectively. Natural mortality (M) is probably in the range of 0.10–0.15. Median ages at maturity were 7–9 years for males and 19–21 years for females. Comparisons of growth curves reported here and elsewhere suggest no regional differences in growth rates. The shortfin mako is a late-maturing species with moderate longevity and low natural mortality. With these life history characteristics and an unknown stock size and structure worldwide, management should be of a precautionary nature.
The effect of river regulation on floodplain wetland inundation, Murrumbidgee River, Australia
Authors: Frazier Paul , Page Ken
Published: March 2006

River regulation by headwater dams has altered the flow regime of rivers worldwide. For floodplain rivers, reduced connectivity between the main channel and floodplain wetlands has led to a decline in ecological health. Current river restoration theory advocates a return towards a more natural regime of floodplain wetland inundation. However, for many rivers, a poor understanding of the natural floodplain wetland inundation regime has hampered effective restoration management. This paper describes a technique for quantifying the effect of flow regulation on the inundation regime of floodplain wetlands on an extended reach of the Murrumbidgee River, Australia. A series of Landsat Thematic Mapper (TM) images, captured before and after a set of floods, was analysed to describe the relationship between flow and inundation for a 640 km river reach. These data were combined with historical regulated and modelled natural daily flow data to show that river regulation has reduced the duration and frequency of wetland inundation by ~40%. For the majority of wetlands the capture of small and medium floods in the headwater dams reduced wetland inundation substantially. However, for low connecting wetlands in reaches upstream of the main irrigation off-takes, summer irrigation flows have increased inundation.
Mortality of larval Murray cod (Maccullochella peelii peelii) and golden perch (Macquaria ambigua) associated with passage through two types of low-head weirs
Authors: Baumgartner Lee J. , Reynoldson Nathan , Gilligan Dean M.
Published: March 2006

Determining factors responsible for increases in the mortality of freshwater fish larvae are important for the conservation of recruitment processes and for the long-term sustainability of freshwater fish populations. To assess the impact of one such process, Murray cod (Maccullochella peelii peelii Mitchell) and golden perch (Macquaria ambigua Richardson) larvae were arranged into treatment and control groups and passed through different configurations (overshot and undershot) of a low-level weir. Passage through an undershot weir resulted in the death of 95 ± 1% golden perch and 52 ± 13% Murray cod. By comparison, mortality was significantly lower in the overshot treatment and both controls. The relatively large number of undershot weirs within the known distribution of these species could impact upon recruitment over a large scale. It is therefore recommended that water management authorities consider the potential threats of operating undershot gated weirs on the survival of larval fish until further research determines appropriate mitigatory measures for these and other species.
Investigating the potential for groundwater from different vegetation, soil and landuses to stimulate blooms of the cyanobacterium, Lyngbya majuscula, in coastal waters
Authors: Ahern Kathleen S. , Udy James W. , Pointon Shane M.
Published: March 2006

Over the past decade, toxic blooms of the cyanobacterium Lyngbya majuscula have increased in frequency and severity in south-east Queensland, Australia, with blooms in Deception Bay linked to increased inputs of dissolved nutrients and organic carbon from land-based sources. The current study investigates the potential for groundwater from ten combinations of vegetation, soil and landuses to stimulate L. majuscula growth in Deception Bay. The photosynthetic response (14C-bicarbonate uptake rate) of L. majuscula to diluted samples of groundwater (1 part groundwater to 19 parts seawater) was measured under laboratory conditions. The results from the present study show that groundwaters from vegetation/soil/landuse systems characterised by acid sulfate soils, exotic pine plantations and Melaleuca vegetation significantly stimulated L. majuscula photosynthesis. These areas typically have low pH and/or high dissolved organic carbon concentrations with strong iron complexation properties, favouring the bioavailability of nutrients. Data from the current study have been incorporated into models and hazard maps to identify areas most vulnerable to the export of nutrients of concern for L. majuscula growth. The hazard maps are part of the Harmful Algal Bloom Policy within the draft South-east Queensland Coastal Management Plan and are aimed at reducing the severity of L. majuscula blooms.
Demographic variation in the New Zealand abalone Haliotis iris
Authors: Naylor J. R. , Andrew N. L. , Kim S. W.
Published: March 2006

Growth data for the New Zealand abalone Haliotis iris were collected from 30 sites around the New Zealand coast by tag–recapture methods. Most data were collected to provide input into abalone stock assessments within discrete management areas, but had not been examined to determine the nature or extent of any large-scale patterns that might be useful to fishery managers. Sites spanned more than 10° of latitude and were subject to a large range of wave energies and temperatures. Mean monthly sea surface temperature (SST) and wave energy were estimated for each site and a generalised linear regression model was used to examine the relationship between variables. Size-at-maturity was also examined at ten sites. Initial length of abalone explained 35% of the variation in incremental growth, and a further 19% was explained by maximum SST, which also explained 60% of the variation in asymptotic length. Fastest growth was generally in areas with lower mean monthly maximum SST, and sites with the slowest growth had the highest mean monthly maximum SST. Size-at-maturity decreased with increasing temperature. The implications of these broad patterns upon abalone fisheries management strategies are discussed.
Population status of 14 shark species caught in the protective gillnets off KwaZulu - Natal beaches, South Africa, 1978 - 2003
Authors: Dudley Sheldon F. J. , Simpfendorfer Colin A.
Published: March 2006

Shark nets have been set off the beaches of KwaZulu–Natal, South Africa, since 1952 to reduce the risk of shark attack. The nets fish in fixed localities 400 m from shore and both directly affect local shark populations and act as fisheries-independent monitoring devices. Reliable catch information at the species level was available for the period 1978–2003. Trends in catch rate and size were used to assess the population status of 14 commonly caught shark species. In addition, a demographic modelling approach was used in conjunction with the catch information to assess the potential effect of the nets on populations. Catch rates of four species (Carcharhinus leucas, C. limbatus, Sphyrna lewini and S. mokarran) showed a significant decline, as did the mean or median length of three species (Carcharhinus amboinensis, C. limbatus and female Carcharodon carcharias). For three species that showed declining catch rates or length the potential effect of the shark nets was assessed to be low, suggesting that other sources of catch were responsible for the declining status. The potential effect of the shark nets was assessed to be high for two species (Carcharhinus obscurus and Carcharias taurus, neither of which showed declines in catch rate or length), because of very low intrinsic rates of population increase.
Effect of Nosocomial Vancomycin-Resistant Enterococcal Bacteremia on Mortality, Length of Stay, and Costs
Authors: Song Xiaoyan , Srinivasan Arjun , Plaut David , Perl Trish M.
Published: March 2006

Objective:

To determine the impact of vancomycin-resistant enterococcal bacteremia on patient outcomes and costs by assessing mortality, excess length of stay, and charges attributable to it.

Design:

A population-based, matched, historical cohort study.

Setting:

A 1,025-bed, university-based teaching facility and referral hospital.

Patients:

Two hundred seventy-seven vancomycin-resistant enterococcal bacteremia case-patients and 277 matched control-patients identified between 1993 and 2000.

Results:

The crude mortality rate was 50.2% and 19.9% for case-patients and control-patients, respectively, yielding a mortality rate of 30.3% attributable to vancomycin-resistant enterococcal bacteremia. The excess length of hospital stay attributable to vancomycin-resistant enterococcal bacteremia was 17 days, of which 12 days were spent in intensive care units. On average, $77,558 in extra charges was attributable to each vancomycin-resistant enterococcal bacteremia. To adjust for severity of illness, 159 pairs of case-patients and control-patients, who had the same severity of illness (All Patient Refined-Diagnosis Related Group complexity level), were further analyzed. When patients were stratified by severity of illness, the crude mortality rate was 50.3% among case-patients compared with 27.7% among control-patients, accounting for an attributable mortality rate of 22.6%. Attributable excess length of stay and charges were 17 days and $81,208, respectively.

Conclusion:

Vancomycin-resistant enterococcal bacteremia contributes significantly to excess mortality and economic loss, once severity of illness is considered. Efforts to prevent these infections will likely be cost-effective.
The Epidemiology of Vancomycin-ResistantEnterococcusColonization in a Medical Intensive Care Unit
Authors: Warren David K. , Kollef Marin H. , Seiler Sondra M. , Fridkin Scott K. , Fraser Victoria J.
Published: March 2006

Objective:

To determine the epidemiology of colonization with vancomycin-resistantEnterococcus(VRE) among intensive care unit (ICU) patients.

Design:

Ten-month prospective cohort study.

Setting:

A 19-bed medical ICU of a 1,440-bed teaching hospital.

Methods:

Patients admitted to the ICU had rectal swab cultures for VRE on admission and weekly thereafter. VRE-positive patients were cared for using contact precautions. Clinical data, including microbiology reports, were collected prospectively during the ICU stay.

Results:

Of 519 patients who had admission stool cultures, 127 (25%) had cultures that were positive for VRE. Risk factors for VRE colonization identified by multiple logistic regression analysis were hospital stay greater than 3 days prior to ICU admission (adjusted odds ratio [AOR], 3.6; 95% confidence interval [CI95], 2.3 to 5.7), chronic dialysis (AOR, 2.4; CI95, 1.2 to 4.5), and having been admitted to the study hospital one to two times (AOR, 2.3; CI95,1.4 to 3.8) or more than two times (AOR, 6.5; CI95, 3.7 to 11.6) within the past 12 months. Of the 352 VRE-negative patients who had one or more follow-up cultures, 74 (21%) became VRE positive during their ICU stay (27 cases per 1,000 patient-ICU days).

Conclusion:

The prevalence of VRE culture positivity on ICU admission was high and a sizable fraction of ICU patients became VRE positive during their ICU stay despite contact precautions for VRE-positive patients. This was likely due in large part to prior VRE exposures in the rest of the hospital where these control measures were not being used.
Bacterial Contamination of Computer Keyboards in a Teaching Hospital
Authors: Schultz Maureen , Gill Janet , Zubairi Sabiha , Huber Ruth , Gordin Fred
Published: March 2006

We tested 100 keyboards in 29 clinical areas for bacterial contamination. Ninety five were positive for microorganisms. Streptococcus, Clostridium perfringens, Enterococcus (including one vancomycin-resistant Enterococcus), Staphylococcus aureus, fungi, and gram-negative organisms were isolated. Computer equipment must be kept clean so it does not become another vehicle for transmission of pathogens to patients.
Implementation of the Canadian Contingency Plan for a Case of Suspected Viral Hemorrhagic Fever
Authors: Loeb Mark , MacPherson Douglas , Barton Michele , Olde Jan
Published: March 2006

Objective:

To describe the implementation of the Canadian contingency plan for viral hemorrhagic fever (VHF) in response to a suspected case.

Setting:

A 300-bed, tertiary-care, university-affiliated hospital.

Participants:

A 32-year-old Congolese woman admitted to the hospital with suspected VHF in February 2001. Contact evaluation included hospital healthcare workers and laboratory staff.

Intervention:

Enhanced isolation precautions were implemented in the patient care setting to prevent nosocomial transmission. Contact tracing and evaluation of close and high-risk contacts with symptoms was conducted. Laboratory precautions included barrier precautions and diversion of specimens. Communication occurred to both hospital employees and the media.

Results:

Three high-risk contacts, 13 close contacts, and 60 casual contacts were identified. Two close contacts became symptomatic and required evaluation. Challenging process issues included tracing of laboratory specimens, decontamination of laboratory equipment, and internal and external communication. After 5 days, a transmissible VHF of public health consequence was ruled out in the index case.

Conclusion:

Contingency plans for VHF can be implemented in an efficient and feasible manner. Contact tracing, laboratory issues, internal communication, and media interest can be anticipated to be the key challenges.
The Changing Epidemiology of Vancomycin-Resistant Enterococci
Authors: Lai Kwan Kew , Fontecchio Sally A. , Kelley Anita L. , Baker Stephen , Melvin Zita S.
Published: March 2006

Objective:

To determine the distribution of vancomycin-resistant enterococci (VRE) cases in our hospital and those from outside of our hospital from 1993 through 1998.

Methods:

Weekly rectal surveillance was instituted whenever there were two or more cases present in the units. Cases were divided into acquired in our hospital, acquired outside of our hospital (VRE positive after and within 72 hours of admission, respectively), and indeterminate. Hospital cases were attributed to the originating ward or intensive care unit (ICU) if patients were noted to be positive within 72 hours of transfer.

Results:

From 1993 to 1998, the rate of VRE per 1,000 admissions increased threefold, from 3.2 to 9.8, for the hospital. VRE cases acquired outside of the hospital increased by approximately 5% per year (r= 0.87;P= .03). The rate of VRE per 1,000 admissions increased 1.7-fold in the ICUs and 3.6-fold in the wards. The ICUs had an average of 75.3 cases per year, with the number of new cases per year increasing by approximately 9 (r= 0.80;P= .028). In the wards, there were an average of 22.0 new cases per year, with a slight upward trend of 3 additional new cases per year (r= 0.69;P= .64). There was a highly significant increasing linear trend (P= .0007) for VRE colonization and infection.

Conclusion:

Although VRE still predominate in the ICUs, cases originating from outside of our hospital and the wards are becoming more common. VRE colonization remained more frequent than infection.
The Epidemiology of Multidrug-ResistantAcinetobacter BaumanniiDoes the Community Represent a Reservoir?
Authors: Zeana Cosmina , Larson Elaine , Sahni Jyoti , Bayuga S. J. , Wu Fann , Della-Latta Phyllis
Published: March 2006

Objective:

To explore the role of the community as a potential reservoir forAcinetobacter baumannii.

Design:

Antimicrobial resistance patterns and genotypes ofA. baumanniiisolates from patients in two Manhattan hospitals were compared with those ofA. baumanniiisolates from the hands of community members.

Results:

A total of 103 isolates from two hospitals (hospital A, 81; hospital B, 22) and 23 isolates from community residents were studied. Of the hospital isolates, 36.6% were multidrug resistant (hospital A, 68.2%; hospital B, 27.8%). In contrast, there were no multidrug-resistant isolates from the community (P< .005 between hospital and community). The prevalence ofA. baumanniion the hands of community residents was 10.4% (23 of 222). By molecular typing, 42 strains of A.baumanniiwere identified. Of the isolates from hospital A and hospital B, 55.6% (45 of 81) and 68.2% (15 of 22), respectively, were indistinguishable or closely related. In contrast, most community (83.3%) isolates were unrelated (P= .001 between hospital and community).

Conclusion:

Acinetobacterisolates from the community, characterized by a large variety of unrelated strains (83.3%), were distinct from the hospital isolates, of which 58.3% were closely related. The absence of multidrug-resistant strains in the community compared with 36.6% prevalence among hospital isolates suggests that the reservoir for epidemic strains resides in the hospital environment itself. To our knowledge, this is the first study to examine the community as a potential reservoir for hospital strains ofA. baumannii.
Antimicrobial Proficiency Testing of National Nosocomial Infections Surveillance System Hospital Laboratories
Authors: Hageman Jeffrey C. , Fridkin Scott K. , Mohammed Jasmine M. , Steward Christine D. , Gaynes Robert P. , Tenover Fred C. ,   National Nosocomial Infections Surveillance (NNIS) System Hospitals
Published: March 2006

Objective:

The National Nosocomial Infections Surveillance (NNIS) System personnel report trends in antimicrobial-resistant pathogens. To validate select antimicrobial susceptibility testing results and to identify test methods that tend to produce errors, we conducted proficiency testing among NNIS System hospital laboratories.

Setting:

NNIS System hospital laboratories in the United States.

Methods:

Each laboratory received five organisms (ie, an imipenem-resistantSerratia marcescens,an oxacillin-resistantStaphylococcus aureus,a vancomycin-resistantEnterococcus faecalis,a vancomycin-intermediateStaphylococcus epidermidis,and an extended-spectrum beta-lactamase (ESβL)-producingKlebsiella pneumoniae).Testing results were compared with reference testing results from the Centers for Disease Control and Prevention.

Results:

Of 138 laboratories testing imipenem against theSerratia marcescensstrain, 110 (80%) correctly reported minimum inhibitory concentrations (MICs) or zone sizes in the resistant range. All 193 participating laboratories correctly reported theStaphylococcus aureusstrain as oxacillin resistant. Of the 193 laboratories, 169 (88%) reported correct MICs or zone sizes for the vancomycin-resistantEnterococcus faecalis.One hundred sixty-two (84%) of 193 laboratories demonstrated the ability to detect a vancomycin-intermediate strain ofStaphylococcus epidermidis;however, disk diffusion performed poorly when testing both staphylococci and enterococci with vancomycin. Although laboratory personnel correctly reported nonsusceptible extended-spectrum cephalosporins and aztreonam results forK. pneumoniae,only 98 (51%) of 193 correctly reported this organism as an ESβL producer.

Conclusion:

Overall, NNIS System hospital laboratory personnel detected most emerging resistance patterns. Disk diffusion continues to be unreliable for vancomycin testing of staphylococci and must be used cautiously for enterococci. Further education on the processing of ESβL-producing organisms is warranted.
Are There Regional Variations in the Diagnosis, Surveillance, and Control of Methicillin-ResistantStaphylococcus aureus?
Authors: Richet Hervé M. , Benbachir Mohamed , Brown Derek F. J. , Giamarellou Helen , Gould Ian , Gubina Marija , Heczko Piotr , Kalenic Smilja , Pana Marina , Pittet Didier , Redjeb Saida Ben , Schindler Jiri , Starling Carlos , Struelens Marc J. , Witte Wolfgang , Jarvis William R. ,   International Network for the Study and Prevention of Emerging Antimicrobial Resistance (INSPEAR)
Published: March 2006

Objective:

To assess the way healthcare facilities (HCFs) diagnose, survey, and control methicillin-resistantStaphylococcus aureus(MRSA).

Design:

Questionnaire.

Setting:

Ninety HCFs in 30 countries.

Results:

Evaluation of susceptibility testing methods showed that 8 laboratories (9%) used oxacillin disks with antimicrobial content different from the one recommended, 12 (13%) did not determine MRSA susceptibility to vancomycin, and 4 (4.5%) reported instances of isolation of vancomycin-resistantS. aureusbut neither confirmed this resistance nor alerted public health authorities. A MRSA control program was reported by 55 (61.1%) of the HCFs. The following isolation precautions were routinely used: hospitalization in a private room (34.4%), wearing of gloves (62.2%), wearing of gowns (44.4%), hand washing by healthcare workers (53.3%), use of an isolation sign on the patient's door (43%), or all four. When the characteristics of HCFs with low incidence rates (< 0.4 per 1,000 patient-days) were compared with those of HCFs with high incidence rates (P= 0.4 per 1,000 patient-days), having a higher mean number of beds per infection control nurse was the only factor significantly associated with HCFs with high incidence rates (834 vs 318 beds;P= .02).

Conclusion:

Our results emphasize the urgent need to strengthen the microbiologic and epidemiologic capacities of HCFs worldwide to prevent MRSA transmission and to prepare them to address the possible emergence of vancomycin-resistantS. aureus.
Predictive Value and Cost-Effectiveness Analysis of a Rapid Polymerase Chain Reaction for Preoperative Detection of Nasal Carriage ofStaphylococcus aureus
Authors: Shrestha Nabin K. , Shermock Kenneth M. , Gordon Steven M. , Tuohy Marion J. , Wilson Deborah A. , Cwynar Roberta E. , Banbury Michael K. , Longworth David L. , Isada Carlos M. , Mawhorter Steven D. , Procop Gary W.
Published: March 2006

Objective:

To determine the accuracy and cost-effectiveness of a polymerase chain reaction (PCR) for detecting nasal carriage ofStaphylococcus aureusdirectly from clinical specimens.

Cross-Sectional Study:

This occurred in a tertiary-care hospital in Cleveland, Ohio, and included 239 consecutive patients who were scheduled for a cardiothoracic surgical procedure. Conventional cultures and a PCR for S.aureusfrom nasal swabs were used as measurements.

Cost-Effectiveness Analysis:

Data sources were market prices and Bureau of Labor Statistics. The time horizon was the maximum period for availability of culture results (3 days). Interventions included universal mupirocin therapy without testing; initial therapy, with termination if PCR negative (treat-PCR); initial therapy, with termination if culture negative (treat-culture); treat PCR-positive carriers (PCR-guided treatment); and treat culture-positive carriers (culture-guided treatment). The perspective was institutional and costs and the length of time to treatment were outcome measures.

Results:

Sixty-seven (28%) of the 239 swabs grewS. aureus.Rapid PCR was 97.0% sensitive and 97.1% specific for the detection of S.aureus.For populations with prevalences of nasalS. aureuscarriage of up to 50%, the PCR assay had negative predictive values of greater than 97%. PCR-guided treatment had the lowest incremental cost-effectiveness ratio ($1.93 per additional day compared with the culture strategy). Among immediate treatment strategies, treat-PCR was most cost-effective. The universal therapy strategy cost $38.19 more per additional day gained with carrier identification compared with the PCR strategy.

Conclusion:

Rapid real-time PCR is an accurate, rapid, and cost-effective method for identifyingS. aureuscarriers for preoperative intervention.
The SBML ODE Solver Library: a native API for symbolic and fast numerical analysis of reaction networks
Authors: Machné Rainer , Finney Andrew , Müller Stefan , Lu James , Widder Stefanie , Flamm Christoph
Published: March 2006

The SBML ODE Solver Library (SOSlib) is a programming library for symbolic and numerical analysis of chemical reaction network models encoded in the Systems Biology Markup Language (SBML). It is written in ISO C and distributed under the open source LGPL license. The package employs libSBML structures for formula representation and associated functions to construct a system of ordinary differential equations, their Jacobian matrix and other derivatives. SUNDIALS' CVODES is incorporated for numerical integration and sensitivity analysis. Preliminary benchmarking results give a rough overview on the behavior of different tools and are discussed in the Supplementary Material. The native application program interface provides fine-grained interfaces to all internal data structures, symbolic operations and numerical routines, enabling the construction of very efficient analytic applications and hybrid or multi-scale solvers with interfaces to SBML and non SBML data sources. Optional modules based on XMGrace and Graphviz allow quick inspection of structure and dynamics.

Availability:  

Contact:  xtof@tbi.univie.ac.at

Supplementary information: Supplementary data are available at Bioinformatics online.
A generalization of the PST algorithm: modeling the sparse nature of protein sequences
Authors: Leonardi Florencia G.
Published: March 2006

Motivation: A central problem in genomics is to determine the function of a protein using the information contained in its amino acid sequence. Variable length Markov chains (VLMC) are a promising class of models that can effectively classify proteins into families and they can be estimated in linear time and space.

Results: We introduce a new algorithm, called Sparse Probabilistic Suffix Trees (SPST), that identifies equivalences between the contexts of a VLMC. We show that, in many cases, the identification of these equivalences can improve the classification rate of the classical Probabilistic Suffix Trees (PST) algorithm. We also show that better classification can be achieved by identifying representative fingerprints in the amino acid chains, and this variation in the SPST algorithm is called F-SPST.

Availability: The SPST algorithm can be freely downloaded from the site

Contact:  leonardi@ime.usp.br

Supplementary information: Supplementary data are available at Bioinformatics online.
The parenting of adolescents in Britain today
Authors: Coleman John C.
Published: March 2006

In this paper it is noted that increased attention has been paid to the topic of parenting in recent years. However, most of this attention has been concentrated on the parenting of young children, with the parenting of adolescents being largely ignored by both practitioners and academics. The paper reviews the available research on the parenting of teenagers, and shows how this could be of use to those who live with young people. The article concludes with some suggestions for new research, and argues that there is an urgent need for greater support and information for this group of parents.
Children, Crime, Policy and Practice: Neither Welfare nor Justice
Authors: Goldson Barry
Published: March 2006

In February 1993 when the Prime Minister proclaimed that ‘society needs to condemn a little more and understand a little less’, and the Home Secretary referred to ‘really persistent nasty little juveniles’ (Daily Mail, 22 February 1993), they set the tone for subsequent policy and practice in relation to children in trouble. It is a policy and practice which in ‘condemning more’ and ‘understanding less’ rides roughshod over the welfare needs of children and negates their claims to justice. Moreover, the representation of children as ‘really persistent nasty little juveniles’ has apparently served to legitimise the harsh excesses of government responses. This paper challenges such ‘legitimacy’ and calls for a fundamental change in the policy and practice relating to children in trouble.
Evidence‐based Medicine and Child Mental Health Services
Authors: McGuire Jacqueline Barnes , Stein Alan , Rosenberg William
Published: March 2006

There is increased focus on using research evidence to guide clinical practice in the provision of child mental health services, to allocate resources and to make policy decisions. Emphasis has been placed on randomised controlled trials, which are clearly vital. However, given the complexity of children's lives and the multiple systems relevant to their care, it is important to consider alternative research designs and to think creatively about outcomes. In the context of difficulties with random allocation a number of quasi‐experimental designs are described that may more closely reflect actual clinical work. In the context of ecological theory, the importance of taking a systems level approach to evaluation is highlighted, with examples from the US. Finally, the ways in which qualitative outcomes measures can be used to sensitively describe the effects of treatment are outlined, and their potential for giving voice to children and families as consumers of mental health services. These suggestions aim to lessen the tension between the requirements of the scientific investigations of treatment effectiveness and the realities of clinicians' daily experiences.
Is the Criminalisation of Child Harm and Injury in the Interests of the Child?
Authors: Wattam Corinne
Published: March 2006

The impetus to prosecute in cases of child harm and injury has increased considerably over recent years with earlier involvement of the police in child protection and incremental legal reform which aims for more child‐centred practices. Research on the implementation of the Memorandum of Good Practice is presented to propose that the prosecution of child abuse is neither achieved nor achievable in the majority of cases and that the assumption on which the criminalisation of child abuse is based should be challenged.
Five‐year‐olds' Perceptions of Why We Go to School
Authors: Sherman Ann
Published: March 2006

Drawing on a recent study intended to reflect the five‐olds' perspective of school this article addresses the question of ‘why we go to school’. Fifty children from five county council reception/year one classrooms were observed and then interviewed over a ten‐week period. There occurs a socialisation of these children to the view that schooling is essential for their preparation for the future. According to the children this takes place during activities identified as ‘work’ not ‘play’ and is emphasised by the compulsory nature of schooling.
Violence in children's programmes on British television
Authors: Gunter Barrie , Harrison Jackie
Published: March 2006

This paper presents a study of violence on children's television in Britain. A total of 943 children's programmes were coded in an exercise which content analysed more than 4,700 hours of programmes broadcast on eight television channels. Thirty nine per cent of these children's programmes contained violence. More than 4,000 violent acts and 7.2 hours of violence occurred in these programmes. More than half of the violence occurred in general children's programmes, with somewhat under half being found in children's cartoons. The violence mostly involved shootings or various forms of physical assault, using hand‐held weapons or the hand or foot. Much of the violence occurred in a crime context or following an argument between two or more individuals. Violence was usually committed for negative purposes, rather than to serve socially positive interests. Violent acts were rarely followed by painful consequences. Perpetrators of violence were most likely to be white, male, young adults, or cartoon characters. Results are discussed in relation to implications for effects upon children and those with responsibilities for children.
Early intervention and identification: finding the family
Authors: Carpenter Barry
Published: March 2006

Following the growth of early intervention programmes for very young children with special educational needs and their families in the 1960s and 1970s, there came a reflective period during which the efficacy of early intervention was questioned (Marfo and Kysela, 1985). This was followed in the 1990s by a challenge to narrow interpretations of effectiveness in favour of a more holistic analysis of the benefits of intervention programmes for the whole family (Buckley, 1994). It was suggested that more attention should be given to the quality of relationships being established between the child and family members and the context in which early intervention programmes are delivered. Families themselves have begun to assert this (Fitton, 1994; Hebden, 1985) and recent legislation, both in the UK and abroad, has underlined the need for strong interdisciplinary approaches to meet the diversity of special educational needs that exist in our child population. This multidisciplinary approach necessitates a change of focus. It recognises the parent, with their child, as central, implicit and fundamental to the early intervention team, and endorses their right to request appropriate access to services. The model also gives parents the freedom to expand the concept of the family to include extended family and friends (for example, Ballard, 1994). Other parent‐empowering initiatives include parent‐to‐parent schemes (Hornby, 1989 and 1995) which increase the capacity of families to provide resources to other families. The days of professionals as experts have passed. This change in approach to families of children with special educational needs will challenge some professionals and demand a radical reappraisal of the structure of their role and their style of delivery of early intervention, but, if we want quality early intervention, such a review is fundamental to re‐establishing its place as a valid and valuable resource to families.
With a little help from my friends? Integration and the role of mainstream pupils
Authors: Allan Julie
Published: March 2006

This paper examines the role of mainstream pupils in the integration of pupils with special educational needs (SEN), based on their accounts of this process. It is argued that mainstream pupils control the experiences of pupils with SEN in both positive and negative ways and that schools need to become more aware of this if integration is to be successful. The paper ends with some suggestions as to how schools might guide mainstream pupils' understanding of disability and promote good relationships.
Where are the children in home–school relations? Notes towards a research agenda
Authors: Edwards Rosalind , David Miriam
Published: March 2006

In this article we unpack the assumptions behind the dominant British research, policy and practice home‐school relations consensus that holds parents' involvement and participation in their children's education to be unquestionably necessary and beneficial. It presupposes a one‐way relationship between parents and children in which children are implicitly placed as dependent and inert recipients of the decisions and activities of parents and teachers. It does not take account of the impacts of the gender of children and their parents, ethnicity, age or family form. We draw on evidence from a diverse range of sources to show that children do have individual and collective interests and priorities in the process of home‐school relations, and that gender is particularly important in this. We argue for research on home‐school relations that takes an essentially child‐centred approach, treating children as competent informants on diverse aspects of parental involvement in their education.
Maintaining contact between parents and children in the public care
Authors: Masson Judith
Published: March 2006

Children looked after by local authorities are at risk of losing contact with parents and significant others despite emphasis in the Children Act 1989 on partnership and promoting contact. Work to maintain contact should address losses before as well as during care. Contact declines over time with lower rates for children in foster care and as social work support for families diminishes. Contact after adoption is increasing; methods of indirect contact developed by adoption agencies may help to maintain contact for looked after children. Lost contact can be restored with social work support.
Values: the curriculum of moral education
Authors: Tomlinson John
Published: March 2006

Against the background of public concern over the moral education of the young, the contemporary constructions imposed upon schools by politicians, the intellectual forces arising from post‐modernism and the pressures of a pluralistic society are examined. The deep structures and slow‐growing processes which can cultivate a sense of moral values in a human community are related to how some schools have successfully achieved a moral community, in which all are valued and can make a contribution. The personal vocation and professionalism of teachers are fundamental.
The provision of education and opportunities for future employment for pregnant schoolgirls and schoolgirl mothers in the UK
Authors: Dawson Nona
Published: March 2006

This paper will report on the results of three recent surveys into educational provision for pregnant schoolgirls and schoolgirl mothers: these surveys have examined the position in England and Wales, and for the first time, in Scotland and in Northern Ireland. As well as reporting what is currently available for young mothers in the UK, the paper will raise issues of entitlement to a full education for these young women, issues of equal opportunity and issues of access. It will seek to point to questions that need to be considered in terms of policy for young mothers and their children. The political debate in the UK has recently centred on the notion of these young women being a drain on the national purse. This paper will seek to address this notion, and will point to the need for access to credible courses leading to employment and childcare in order to increase the chances of these young women becoming taxpayers, and good parents.