bluuebunny/crossref_metadata_2025 huggingface dataset:
Investment in employer shares, incentive alignment, and monitoring
Authors: SOUMARÉ ISSOUF
Published: June 2007

It is well documented that US defined contribution pension plans are largely invested in the shares of their employer. I argue that when the (single representative) worker holds shares in the firm, he tends to monitor the manager. On the one hand, the manager and shareholders gain from the productivity of the worker. On the other hand, the manager bears the cost of being monitored by the worker, and the shareholders loose part of their ownership power to the worker. Therefore, there is an optimal ownership limit for the worker from the viewpoint of the firm. I derive conditions under which the worker will never invest in the firm's stock if he has the freedom to do so. Nevertheless, under alternative conditions, it will be advantageous for the worker to invest his pension assets heavily in company stock, even if the under-diversification cost is very high.
Can professors afford to retire? Evidence from a survey of Canadian university pension plans
Authors: GOSS ALLEN
Published: June 2007

I explore the diversity among pension plans offered to faculty at 52 Canadian universities. Far from displaying homogeneity, I find marked differences between the plans, both in their structure (DB, DC, and hybrid) and in the replacement ratios from those plans. Using financial simulations I construct representative pension payoff profiles for each plan and find expected replacement ratios (the annual annuity stream available at retirement expressed as a percentage of final wages) ranging from 54.3% to 88.2% and internal rates of return on contributions varying from 10.39% to 18%.
Hf isotope compositions of U.S. Geological Survey reference materials
Authors: Weis Dominique , Kieffer Bruno , Hanano Diane , Nobre Silva Inês , Barling Jane , Pretorius Wilma , Maerschalk Claude , Mattielli Nadine
Published: June 2007

A systematic multi‐isotopic and trace element characterization of U.S. Geological Survey reference materials has been carried out at the Pacific Centre for Isotopic and Geochemical Research, University of British Columbia. Values of 176Hf/177Hf are recommended for the following reference materials (mean ±2 SD): G‐2: 0.282523 ± 6; G‐3: 0.282518 ± 1; GSP‐2: 0.281949 ± 8; RGM‐1: 0.283017 ± 13; STM‐1: 0.283019 ± 12; STM‐2: 0.283021 ± 5; BCR‐1: 0.282875 ± 8; BCR‐2: 0.282870 ± 8; BHVO‐1: 0.283106 ± 12; BHVO‐2: 0.283105 ± 11; AGV‐1: 0.282979 ± 6; and AGV‐2: 0.282984 ± 9. Reproducibility is better than 50 ppm for the granitoid compositions and better than 40 ppm for the basaltic/andesitic compositions. For the isotopic analyses acquired early in this project on glass columns, Hf isotopic analyses from several of the reference materials were significantly less reproducible than Nd and Sr isotopic analyses determined from the same sample dissolution. The 176Hf/177Hf ratios for relatively radiogenic compositions (BCR‐1, 2; BHVO‐1, 2; RGM‐1) were shifted systematically toward lower values by 100–150 ppm when a borosilicate primary column was used. Although systematic, the shift for felsic compositions was generally within analytical error, except for GSP‐2, which has a very low Hf isotopic ratio, where the shift was to higher 176Hf/177Hf. Trace element and isotopic characterization of the borosilicate glass column, borosilicate frits, and quartz columns reveals extremely variable levels of trace elements. The 176Hf/177Hf ratios for these materials are very unradiogenic (borosilicate glass <0.28220; frit = 0.28193 ± 4). The borosilicate frit material appears to be the most variable in elemental concentration and isotopic composition. The quartz material has very low levels (<ppm) of all trace elements. Low 176Hf/177Hf and high Hf concentrations of the borosilicate glass column (16 ppm) and frit material (22 ppm) indicate that only small amounts of such unradiogenic material could cause significant contamination of small samples. For the basaltic (BCR‐1, 2; BHVO‐1, 2) and rhyolitic (RGM‐1) samples, approximately 3 ng of Hf from the column or frit would be enough to produce the observed 100–150 ppm shift. Accurate, high‐precision 176Hf/177Hf data can only be acquired if samples are processed using all PTFE Teflon® labware, or quartz and polypropylene.
Summertime ENSO–North African–Asian Jet teleconnection and implications for the Indian monsoons
Authors: Shaman Jeffrey , Tziperman Eli
Published: June 2007

Recent findings indicate that ENSO may modulate the strength of the Indian monsoons by altering the meridional tropospheric temperature gradient between Asia and the equatorial Indian Ocean. Here we show that during northern hemisphere summertime El Niño events both colder upper tropospheric temperatures and increased vorticity anomalies are observed within the North African‐Asian (NAA) jet. The temperature response within the NAA jet is the dominant ENSO‐related change to the meridional tropospheric temperature gradient between Asia and the equatorial Indian Ocean. Forced solutions of the linearized barotropic vorticity equation indicate that these anomalies within the NAA jet are a response to northern hemisphere summertime El Niño‐related convective activity over the equatorial Pacific Ocean. Additional experiments indicate that westward propagating anomalies in both the tropics and middle latitudes produce the anomaly response within the NAA jet. These findings suggest that the teleconnection linking ENSO and the monsoons is mediated by the response of the NAA jet to westward propagating Rossby waves.
Nitrogen oxide measurements at rural sites in Switzerland: Bias of conventional measurement techniques
Authors: Steinbacher M. , Zellweger C. , Schwarzenbach B. , Bugmann S. , Buchmann B. , Ordóñez C. , Prevot A. S. H. , Hueglin C.
Published: June 2007

Nitrogen oxides (NOx = NO + NO2) in the atmosphere are often measured using instruments equipped with molybdenum converters. NO2 is catalytically converted to NO on a heated molybdenum surface and subsequently measured by chemiluminescence after reaction with ozone. The drawback of this technique is that other oxidized nitrogen compounds such as peroxyacetyl nitrate and nitric acid are also partly converted to NO. Thus such NO2 measurements are really surrogate NO2 measurements because the resultant values systematically overestimate the true value because of interferences of these compounds, especially when sampling photochemically aged air masses. However, molybdenum converters are widely used, and a dense network of surrogate NO2 measurements exists. As an alternative with far less interference, photolytic converters using ultraviolet light are nowadays applicable also for long‐term measurements. This work presents long‐term collocated NO2 measurements using molybdenum and photolytic converters at two rural sites in Switzerland. On a relative scale, the molybdenum converter instruments overestimate the NO2 concentrations most during spring/summer because of prevalent photochemistry. On a monthly basis, only 70–83% of the “surrogate” NO2 can be attributed to “real” NO2 at the non‐elevated site and even less (43–76%) at the elevated one. The observed interferences have to be taken into account for monitoring and regulatory issues and to be considered when using these data for ground‐truthing of satellite data or for validation of chemical transport models. Alternatively, an increased availability of artifact‐free data would also be beneficial for these issues.
Apatite fission track data from central Anatolian granitoids (Turkey): Constraints on Neo‐Tethyan closure
Authors: Boztuğ Durmuş , Jonckheere Raymond C.
Published: June 2007

Apatite fission track age versus elevation profiles and temperature‐time‐path modeling indicate an early to middle Paleocene (57–62 Ma) rapid exhumation of the Middle to Late Cretaceous granitoids in central Anatolia and an Oligocene (28–30 Ma) rapid exhumation of the Eocene Kösedağ batholith in the NE Sivas region, part of eastern central Pontides. The early to middle Paleocene rapid exhumation is thought to result from a regional compressional regime following the collision of the Eurasian Plate and the Tauride‐Anatolide Platform at the closure of the Izmir‐Ankara‐Erzincan branch of the northern Neo‐Tethys. The Oligocene accelerated exhumation of the Kösedağ batholith is contemporaneous with the Oligo‐Miocene closure of the southern Neo‐Tethys which juxtaposed the amalgamated Eurasian and Tauride‐Anatolide Platform and the African‐Arabian Plate along the Bitlis‐Zagros suture in southeast Anatolia. The compressional regime due to this collision affected a large area between the Greater Caucasus in the north and northern African‐Arabian Plate in the south.
Multiobjective sensitivity analysis of sediment and nitrogen processes with a watershed model
Authors: Arabi Mazdak , Govindaraju Rao S. , Engel Bernie , Hantush Mohamed
Published: June 2007

This paper presents a computational analysis for evaluating critical non‐point‐source sediment and nutrient (specifically nitrogen) processes and management actions at the watershed scale. In the analysis, model parameters that bear key uncertainties were presumed to reflect the importance of natural processes and/or management actions that they represent. The multiobjective generalized sensitivity analysis and the tree‐structured density estimation procedures were used in combination to investigate correlation structure in the parameter space while accounting for multiple objectives. Using the Soil and Water Assessment Tool, this framework was applied to the Dreisbach watershed in Indiana in the Midwestern portion of the United States. Results showed that incorporation of parameter interactions and multiple objectives is essential to obtaining conclusive information about critical system processes and management actions. Interactions between surface runoff volume and within‐channel processes were critical to describe transport of sediments in the study watershed. Key management actions for total nitrogen control were found to be nitrogen fertilizer application and upland farming practices. The sensitivity analysis reported herein could be used to derive a list of key non‐point‐source best management practices for development of watershed management plans. Implications of the analysis that are relevant to calibration of complex watershed models are discussed.
Probabilistic structure of storm surface runoff considering the dependence between average intensity and storm duration of rainfall events
Authors: Kao Shih‐Chieh , Govindaraju Rao S.
Published: June 2007

The probabilistic nature of rainfall and surface runoff events forms the basis of hydrologic design. Two defining characteristics of rainfall events, average intensity and duration, are selected to construct the probabilistic structure of storms using Gumbel's bivariate exponential distribution. This bivariate stochastic rainfall model is then utilized to derive the probabilistic structure of surface runoff using the Soil Conservation Service rainfall runoff model. The zero‐runoff probability, mean, and standard deviation of rainfall excess are evaluated. Copulas serve as an alternative way to derive zero‐runoff probability. The results indicate that the dependence between average intensity and duration has a significant effect on statistical properties of rainfall excess. The advantage of using copulas for complicated multivariate stochastic models is demonstrated. The proposed model is associated with land use and soil type information from the geographic information system to produce maps of statistical properties of rainfall excess. A case study of model application is performed for the state of Indiana, United States. Results show that while the mean and standard deviation of rainfall excess increase with curve number, these quantities are very sensitive to the dependence between average intensity and duration of storm events.
Bromoform in tropical Atlantic air from 25°N to 25°S
Authors: Carpenter Lucy J. , Wevill David J. , Hopkins James R. , Dunk Rachel M. , Jones Charlotte E. , Hornsby Karen E. , McQuaid James B.
Published: June 2007

Atmospheric mixing ratios of bromoform (CHBr3) measured over the eastern Atlantic Ocean were enhanced (4 to 13 pptv) between 8–25°N, 17–21°W, in air masses advected over the NW African coast/upwelling zone. The highest mixing ratios at 8–10°N were associated with a biomass burning plume from the African savannah belt. Airborne samples taken over Nigeria showed however that biomass burning here is not a source of CHBr3. Previously reported water samples taken near to the NW African upwelling zone do not support the very high levels of atmospheric CHBr3 observed, unless there is significant surface stratification of the atmospheric boundary layer. Other potential explanations include coastal macroalgae and/or sources within continental Africa. It is important to ascertain the nature of tropical sources of CHBr3 in order to establish the mechanisms of suggested feedbacks between organic bromine and climate change.
Chronic 5‐HT6 receptor modulation by E‐6837 induces hypophagia and sustained weight loss in diet‐induced obese rats
Authors: Fisas A , Codony X , Romero G , Dordal A , Giraldo J , Mercé R , Holenz J , Vrang N , Sørensen R V , Heal D , Buschmann H , Pauwels P J
Published: June 2007

British Journal of Pharmacology (2007) 151, 564; doi:10.1038/sj.bjp.0707268
Stimulation of rat erythrocyte P2X7receptor induces the release of epoxyeicosatrienoic acids
Authors: Jiang H , Zhu A G , Mamczur M , Falck J R , Lerea K M , McGiff J C
Published: June 2007

Background and purpose:

Red blood cells (RBCs) are reservoirs of vasodilatory, antiaggregatory, and antiinflammatory lipid mediators—epoxyeicosatrienoic acids (EETs). This study addresses the formation and release of erythrocyte‐derived EETs in response to ATP receptor stimulation that may represent an important mechanism regarding circulatory regulation.

Experimental approach:

Erythrocyte EET formation and release were investigated by incubating rat RBCs in physiological salt solution with agents that effected ATP release via P2 receptor stimulation of phospholipase A2 and epoxygenase‐like activities with activation of the ATP secretory mechanism. EETs were analyzed by gas and liquid chromatography‐mass spectrometry.

Key results:

EETs were released from rat RBCs: 14,15‐, 11,12‐, 8,9‐ and 5,6‐EETs in a ratio of 1.2:1.0:0.9:0.8. EETs were produced by epoxidation of arachidonic acid catalyzed by hemoglobin. Spontaneous release of EETs, 0.66±0.14 ng per 109RBCs, was dose‐dependently increased by an ATP analog, BzATP, and inhibited by P2X7receptor antagonists. 5 μM ATP increased release of EETs over 20% to 0.83±0.15 ng per 109RBCs; 10 μM BzATP tripled the amount of EET release to 1.87±0.20 ng per 109RBCs. EET release by ATP or BzATP was not associated with hemolysis. Carbenoxolone, a gap junction inhibitor that inhibits ATP release, and glibenclamide, an inhibitor of the cystic fibrosis transmembrane conductance regulator (CFTR), which is required for ATP release, inhibited the spontaneous and stimulated EET release from RBCs.

Conclusions and implications:

EETs are produced and released from RBCs via a mechanism that is mediated by ATP stimulation of P2X7receptors coupled to ATP transporters, pannexin‐1 and CFTR.

British Journal of Pharmacology(2007)151, 1033–1040; doi:10.1038/sj.bjp.0707311
Cardiovascular gene therapy: current status and therapeutic potential
Authors: Gaffney M M , Hynes S O , Barry F , O'Brien T
Published: June 2007

Gene therapy is emerging as a potential treatment option in patients suffering from a wide spectrum of cardiovascular diseases including coronary artery disease, peripheral vascular disease, vein graft failure and in‐stent restenosis. Thus far preclinical studies have shown promise for a wide variety of genes, in particular the delivery of genes encoding growth factors such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) to treat ischaemic vascular disease both peripherally and in coronary artery disease. VEGF as well as other genes such as TIMPs have been used to target the development of neointimal hyperplasia to successfully prevent vein graft failure and in‐stent restenosis in animal models. Subsequent phase I trials to examine safety of these therapies have been successful with low levels of serious adverse effects, and albeit in the absence of a placebo group some suggestion of efficacy. Phase 2 studies, which have incorporated a placebo group, have not confirmed this early promise of efficacy. In the next generation of clinical gene therapy trials for cardiovascular disease, many parameters will need to be adjusted in the search for an effective therapy, including the identification of a suitable vector, appropriate gene or genes and an effective vector delivery system for a specific disease target. Here we review the current status of cardiovascular gene therapy and the potential for this approach to become a viable treatment option.

British Journal of Pharmacology (2007) 152, 175–188; doi:10.1038/sj.bjp.0707315
Modulation by simvastatin of iberiotoxin‐sensitive, Ca2+‐activated K+ channels of porcine coronary artery smooth muscle cells
Authors: Seto S W , Au A L S , Lam T Y , Chim S S C , Lee S M Y , Wan S , Tjiu D C S , Shigemura N , Yim A P C , Chan S W , Tsui S K W , Leung G P H , Kwan Y W
Published: June 2007

Background and Purpose:

Statins (3‐hydroxy‐3‐methyl‐glutaryl coenzyme A (HMG CoA) reductase inhibitors) have been demonstrated to reduce cardiovascular mortality. It is unclear how the expression level of HMG CoA reductase in cardiovascular tissues compares with that in cells derived from the liver. We hypothesized that this enzyme exists in different cardiovascular tissues, and simvastatin modulates the vascular iberiotoxin‐sensitive Ca2+‐activated K+ (BKCa) channels.

Experimental Approaches:

Expression of HMG CoA reductase in different cardiovascular preparations was measured. Effects of simvastatin on BKCa channel gatings of porcine coronary artery smooth muscle cells were evaluated.

Key Results:

Western immunoblots revealed the biochemical existence of HMG CoA reductase in human cardiovascular tissues and porcine coronary artery. In porcine coronary artery smooth muscle cells, extracellular simvastatin (1, 3 and 10 μM) (hydrophobic), but not simvastatin Na+ (hydrophilic), inhibited the BKCa channels with a minimal recovery upon washout. Isopimaric acid (10 μM)‐mediated enhancement of the BKCa amplitude was reversed by external simvastatin. Simvastatin Na+ (10 μM, applied internally), markedly attenuated isopimaric acid (10 μM)‐induced enhancement of the BKCa amplitude. Reduced glutathione (5 mM; in the pipette solution) abolished simvastatin ‐elicited inhibition. Mevalonolactone (500 μM) and geranylgeranyl pyrophosphate (20 μM) only prevented simvastatin (1 and 3 μM)‐induced responses. simvastatin (10 μM) caused a rottlerin (1 μM)‐sensitive (cycloheximide (10 μM)‐insensitive) increase of PKC‐δ protein expression.

Conclusions and Implications:

Our results demonstrated the biochemical presence of HMG CoA reductase in different cardiovascular tissues, and that simvastatin inhibited the BKCa channels of the arterial smooth muscle cells through multiple intracellular pathways.

British Journal of Pharmacology (2007) 151, 987–997; doi:10.1038/sj.bjp.0707327
Quantitative and Qualitative Follow-Up Outcomes From a Preschool Audiologic Screening Program: Perspectives Over a Decade
Authors: Serpanos Yula C. , Jarmel Fredi
Published: June 2007

Purpose

This investigation reports on quantitative and qualitative follow-up information obtained from a preschool audiologic screening program covering a 10-year period (1995 to 2004).

Method

The audiologic screening consisted of a hearing (pure tone) and tympanometry screening. A total of 34,979 children, 3 to 5 years of age, were screened.

Results

Eighteen percent (6,337) of the children were referred for further hearing and/or medical ear evaluation. Of 1,421 follow-up responses received, 93% complied with the follow-up recommendations while 7% did not. Of 1,316 children in the follow-up group, outer and/or middle ear disorder in one or both ears was medically confirmed for 37%. Unilateral or bilateral hearing loss was diagnosed in 18% as conductive (12%), sensorineural (1%), mixed (0.4%), or unspecified (5%). Overall, hearing loss and/or otologic disorder was confirmed in 49% of the follow-up group, suggesting a prevalence of 1.8% in a preschool-age population. A small (n= 32) sample of unsolicited comments indicated that physicians most influenced noncompliance with hearing evaluation follow-up.

Conclusions

The quantitative hearing and otologic follow-up outcome data affirm the importance of audiologic screening in the preschool population. Qualitative data suggest that some physicians may not be advocating appropriate screening follow-up services.
Cochlear Implants in Young Children: Informed Consent as a Process and Current Practices
Authors: Berg Abbey L. , Ip Suzie Catherine , Hurst Marsha , Herb Alice
Published: June 2007

Purpose

This study examined the types of information that pediatric cochlear implant (PCI) centers and teams provide to parents of deaf children and the extent to which the informed consent process extends beyond medical issues to include social and cultural aspects. A second purpose was to determine the extent to which centers are applying selected new practices in cochlear implantation: younger age at implantation and bilateral implantation.

Method

A 23-question survey was sent to 445 cochlear implant centers in the United States. Of the 445 centers contacted, 188 (42%) were excluded as ineligible (nonpediatric), 257 (58%) were determined eligible, and 121 (47%) of these completed the survey. Survey topics included characteristics of PCI centers and teams; the role and importance of professionals/consultants; types of medical, educational, Deaf culture, and identity information and perspectives provided to parents; and current practices regarding age of implantation and bilateral implantation.

Results

All of the PCI teams completing the survey presented medical/surgical risks, audiologic information, and variability of communication/educational options; fewer than half (45%) presented Deaf culture and emerging autonomy/identity issues to parents. Most PCI centers felt the optimal age to implant a child was 10–15 months. The majority of PCI centers, regardless of affiliation with a teaching hospital, responded that they rarely or never implanted bilaterally, and few discussed bilateral implants with parents.

Conclusions

Audiologists are the only nonsurgical professionals always represented on the cochlear implant team. In order to best prepare audiologists for this role, graduate audiology programs need to address more extensively the Deaf culture and perspective, as well as genetics of hearing loss. Increased attention to educational audiology and evidence-based research regarding best age to implant and bilateral implantation needs to be included in the discussion with parents. Audiologists play a crucial role in informing parents and coordinating care, and should therefore carefully consider their role in the informed consent process.
Evaluating Families' Satisfaction With Early Hearing Detection and Intervention Services in Massachusetts
Authors: MacNeil Jessica R. , Liu Chia-ling , Stone Sarah , Farrell Janet
Published: June 2007

Purpose

To determine levels of families' satisfaction and anxiety associated with the early hearing detection and intervention (EHDI) process in Massachusetts, and to assess the relationship between a child’s hearing status and levels of family satisfaction.

Method

Surveys were mailed to families whose infants (a) passed their initial hearing screening (Group 1), (b) did not pass their initial screening but subsequently passed an outpatient rescreen or diagnostic evaluation (Group 2), or (c) were identified with permanent hearing loss (Group 3). Survey instruments measured families' satisfaction and anxiety associated with each stage of the EHDI process.

Results

Of the 4,138 families surveyed, 1,106 (27%) responded. Families reported satisfaction with screening services (Group 1 = 88%; Group 2 = 86%; Group 3 = 75%), and few reported anxiety prior to the hearing screening (Group 1= 4%; Group 2 = 15%; Group 3 = 19%). Among families requiring retesting services, 97% of Group 2 and 87% of Group 3 families were satisfied. Among Group 3 families, 94% reported satisfaction with the care their audiologist was providing, and 79% were satisfied with their early intervention services overall.

Conclusions

Families reported satisfaction with the EHDI services they received in Massachusetts and expressed strong support for the universal newborn hearing screening initiative.
Parental Narratives of Genetic Testing for Hearing Loss: Audiologic Implications for Clinical Work With Children and Families
Authors: Steinberg Annie , Kaimal Girija , Ewing Rachel , Soslow Lisa P. , Lewis Kathleen M. , Krantz Ian , Li Yuelin
Published: June 2007

Purpose

Few studies have examined how parents personalize the possibility of genetic hearing loss in their children and whether they actually intend to pursue testing for their child. This article addresses the audiologist’s important role in the genetic testing referral and follow-up processes.

Method

Twenty-four parents whose children were referred to genetic testing for hearing loss were interviewed in depth. Parents were selected to include a diverse range of races, ethnicities, and socioeconomic levels. Interviews were coded and analyzed using qualitative methods.

Results

Parental associations with genetic testing included feeling personally responsible, feeling relief, and considering metaphysical attributions for their child’s hearing loss. Parental attitudes were related to perceptions and experiences with deafness. Many misconceptions about genetics were also found.

Conclusions

Audiologists need to be sensitized to parents' personal and sociocultural contexts when discussing genetic testing and should tailor informational and emotional support to parents' requirements when confronting the possibility of their child having a genetic hearing loss.
Thermal buckling parametric analysis for a diamond disk for a x-ray beamline at the Advanced Photon Source
Authors: Nian H. L. Thomas , Kuzay Tuncer M. , Sheng I. C.
Published: June 2007

A thermal buckling analysis for a diamond disk in the commissioning window assembly designed for x-ray beamlines at the Advanced Photon Source is presented. The analytical solution together with associated numerical analysis help to predict the critical temperature of the diamond disk before a thermal buckle occurs.
Spatial imaging of monochromatic hard x-rays from an APS undulator by the Kohzu double-crystal monochromator (abstract)
Authors: Mills D.M. , Lee W.K. , Keeffe M. , Haeffner D.R. , Fernandez P.
Published: June 2007

The spatial distribution of monochromatic x-rays produced by an APS undulator was imaged on a fluorescent screen and recorded with a video camera while commissioning the Kohzu double-crystal monochromator (DCM). Two sets of images were recorded: Case 1 in which the spectral output of the undulator is fixed (constant magnetic gap) and the monochromator is scanned in energy, and Case 2 in which the monochromator energy is held fixed and the spectral output of the undulator is varied by changing the magnetic gap of the insertion device. Because of the performance of the Kohzu monochromator, the mechanical conditions required to maintain the twice-diffracted beam could be preserved as the DCM was scanned in energy, allowing the evolution as a function of energy. The images are compared with the calculated spatial distributions of monochromatic undulator radiation.
Importance of components cleaning in the ultrahigh vacuum performance of beamline front ends
Authors: Liu C. , Collins J. T. , Nielsen R. W. , Kruy T. L. , Ramanathan M. , Kuzay T. M.
Published: June 2007

The Advanced Photon Source (APS) has 40 beamline front ends in its initial phase of operations; eventually a total of 69 beamline front ends will be connected to the storage ring. The ultrahigh vacuum performance of these front ends will have a significant impact on the storage ring vacuum and on the lifetime of the positron beam. In this paper we emphasize the importance of proper component cleaning to the ultrahigh vacuum performance of beamline front ends. Critical issues in the cleaning process include using environmentally friendly cleaning agents and applications of ultrasonic agitation, thorough deionized water rinsing, and vacuum furnace baking. A simple and cost-effective cleaning facility consisting of ultrasonic cleaning tanks, a drying tank, and a vacuum furnace has been set up. The effectiveness of component cleaning is evaluated by the base pressure achievable in comparison to what is expected according to vacuum calculations using available outgassing rates for the components. Each major component is vacuum tested before final assembly. Vacuum comparisons in some vendor-provided components before and after additional cleaning will be discussed.
Design of the commissioning filter/mask/window assembly for undulator beamline front ends at the Advanced Photon Source
Authors: Shu Deming , Kuzay Tuncer M.
Published: June 2007

A compact filter/mask/window assembly has been designed for undulator beamline commissioning activity at the Advanced Photon Source beamlines. The assembly consists of one 300-μm graphite filter, one 127-μm CVD diamond filter and two 250-μm beryllium windows. A water-cooled Glidcop fixed mask with a 4.5 mm×4.5 mm output optical aperture and a 0.96 mrad×1.6 mrad beam missteering acceptance is a major part in the assembly. The CVD diamond filter, which is mounted on the downstream side of the fixed mask, is designed to also function as a transmitting x-ray beam position monitor. The sum signal from the latter can be used to monitor the physical condition of the graphite filter and prevent any possible chain reaction damage to the beryllium windows downstream. In this paper, the design concept as well as the detailed structural design of the commissioning window are presented. Further applications of the commissioning window components are also discussed.
Analysis of Independent Risk Factors for Death Among Pediatric Patients With Candidemia and a Central Venous Catheter in Place
Authors: Pasqualotto Alessandro C. , de Moraes Anaelena B. , Zanini Roselaine R. , Severo Luiz Carlos
Published: June 2007

Objective.

To use multivariate analysis to determine risk factors for death among pediatric patients with candidemia and a central venous catheter in place.

Design.

Retrospective cohort study conducted at Santa Casa Complexo Hospitalar, a 1,200-bed teaching hospital in southern Brazil.

Methods.

All cases of candidemia in pediatric patients (age, ≤ 13 years) at our medical center over a 9-year period were reviewed. A diagnosis of sepsis was required for inclusion in the study. Severity of illness was confirmed by the presence of hypotension requiring inotropes and according to the following scores: the Pediatric Risk of Mortality (PRISM) II score, the PRISM III score, and the Pediatric Logistic Organic Dysfunction score. The following 2 outcomes were evaluated: early death, defined as death occurring within 7 days after candidemia was diagnosed, and late death, defined as death 8-30 days after candidemia was diagnosed.

Results.

A total of 61 patients were included in the study, including 14 neonates. Most (63.9%) of these patients were girls, and the median age was 0.3 years. A total of 80.3% of candidemia cases were due to species other than Candida albicans, primarily Candida parapsilosis (32.8% of cases) and Candida tropicalis (24.6% of cases). Using multivariate analysis, we demonstrated that failure to remove the central venous catheter was an independent risk factor for early death among pediatric patients with candidemia. However, patients whose catheters were retained were sicker than patients whose catheters were removed, and catheter removal had no impact on late death. Instead, severity of illness determined using the PRISM III score was also an independent predictor of late death.

Conclusions.

Results from this study suggest that systematic removal of catheters from pediatric patients with candidemia does not reduce the occurrence of late death.
Validation of Coronary Artery Bypass Graft Surgical Site Infection Surveillance Data From a Statewide Surveillance System in Australia
Authors: Friedman N. Deborah , Russo Philip L. , Bull Ann L. , Richards Michael J. , Kelly Heath
Published: June 2007

Objective.

To measure the accuracy and determine the positive predictive value (PPV) and negative predictive value (NPV) of data submitted to a statewide surveillance system for identifying surgical site infection (SSI) complicating coronary artery bypass graft (CABG) surgery.

Design.

Retrospective review of hospital medical records comparing SSI data with surveillance data submitted by infection control consultants (ICCs).

Setting.

Victorian Hospital Acquired Infection Surveillance System (VICNISS) Coordinating Centre in Victoria, Australia.

Patients.

All patients reported to have an SSI following CABG surgery and a random sample of approximately 10% of patients reported not to have an SSI following CABG surgery.

Results.

The VICNISS ascertainment rate for CABG procedures in Victoria was 95%. One hundred sixty-nine medical records were reviewed, and reviewers agreed with ICCs about 46 (96%) of the patients reported as infected by the ICCs and 31 (91%) of the patients identified with a sternal SSI by the ICCs. In one-third of SSIs, the depth of SSI documented by ICCs was discordant with that documented by the reviewers. Disagreement about patients with donor site SSI was frequent. When the review findings were used as the reference standard, the PPV for ICC-reported SSI was 96% (95% confidence interval [CI], 86%-99%), and the NPV was 97% (95% CI, 92%-99%). For ICC-reported sternal SSI, the PPV was 91% (95% CI, 76%-98%) and the NPV was 98% (95% CI, 94%-100%).

Conclusions.

There was broad agreement on the number of infected patients and the number of patients with sternal SSI. However, discordance was frequent with respect to the depth of sternal SSI and the identification of donor site SSI. We recommend modifications to the methodology for National Noscomial Infection Surveillance System-based surveillance for SSI following CABG surgery.
Is Targeted Surveillance Effective for Surgical Site-Infection Control? Results in Digestive Tract Surgery from the Incidence des Infections du Site Opératoire Network
Authors: Olivier Marion , Grandbastien Bruno , Astagneau Pascal
Published: June 2007

We used 6 years of surgical site infection (SSI) data collected by a surveillance system in northern France to compare targeted and pooled surveillance models. Digestive tract surgery wards were ranked according to SSI risk for herniorraphy, appendectomy, and cholecystectomy. The pooled and targeted models were correlated, despite differences in the number of outlier wards detected, indicating that the ranking of wards according to whether they have met a specified benchmark SSI rate depends on the strategy chosen.
Microbiology of Ventilator–Associated Pneumonia Compared With That of Hospital-Acquired Pneumonia
Authors: Weber David J. , Rutala William A. , Sickbert-Bennett Emily E. , Samsa Gregory P. , Brown Vickie , Niederman Michael S.
Published: June 2007

Objective.

Nosocomial pneumonia is the leading cause of mortality attributed to nosocomial infection. Appropriate empirical therapy has been associated with improved survival, but data are limited regarding the etiologic agents of hospital-acquired pneumonia in non-ventilated patients (HAP). This evaluation assessed whether the currently recommended empirical therapy is appropriate for both ventilator-associated pneumonia (VAP) and HAP by evaluating the infecting flora.

Design.

Prospectively collected hospitalwide surveillance data was obtained by infection control professionals using standard Centers for Disease Control and Prevention definitions.

Setting.

A tertiary care academic hospital.

Patients.

All patients admitted from 2000 through 2003.

Results.

A total of 588 episodes of pneumonia were reported in 556 patients: 327 episodes of VAP in 309 patients, and 261 episodes of HAP in 247 Patients. The infecting flora in ventilated patients included gram-positive cocci (32.0% [oxacillin-susceptible Staphylococcus aureus {OSSA}, 9.25%; oxacillin-resistant Staphylococcus aureus {ORSA}, 17.75%]), gram-negative bacilli (59.0% {Pseudomonas aeruginosa, 17.50%; Stenotrophomonas maltophilia, 6.75%; Acinetobacter species, 7.75%), and miscellaneous pathogens (9.0%). The infecting flora in nonventilated patients included gram-positive cocci (42.59% [OSSA, 13.33%; ORSA, 20.37%]), gram-negative bacilli (39.63% [P. aeruginosa, 9.26%; S. maltophilia, 1.11%; Acinetobacter species, 3.33%), and miscellaneous pathogens (17.78%).

Conclusions.

Our data demonstrated that patients with HAP, compared with those with VAP, had a similar frequency of infection with ORSA but less commonly had infections due to P. aeruginosa, Acinetobacter species, and S. maltophilia. However, the overall frequency of infection with these pathogens was sufficiently high to warrant the use of empirical therapy likely to be active against them. Our data supports using the currently recommended empirical therapy for both HAP and VAP.
Methicillin-ResistantStaphylococcus aureusInfection and Colonization Among Hospitalized Prisoners
Authors: Wright Marc-Oliver , Furuno Jon P. , Venezia Richard A. , Johnson Jennifer K. , Standiford Harold C. , Hebden Joan N. , Hill Judith , Hartley David M. , Harris Anthony D. , Perencevich Eli N.
Published: June 2007

We assessed methicillin-resistantStaphylococcus aureus(MRSA) infection and colonization in hospitalized prisoners. Of 434 admission surveillance cultures, 58 (13%) were positive for MRSA. The sensitivity of admission surveillance cultures of samples from the anterior nares was 72% and increased to 84% when the calculation included cultures of wound samples. Hospitalized prisoners are at high risk for MRSA infection and colonization, and surveillance should include cultures of nares and wound samples.
Risk Factors for and Outcomes of Healthcare-Associated Infection Due to Extended-Spectrum β-Lactamase-Producing Escherichia coli or Klebsiella pneumoniae in Thailand
Authors: Apisarnthanarak Anucha , Kiratisin Pattarachai , Saifon Payawan , Kitphati Rungrueng , Dejsirilert Surang , Mundy Linda M.
Published: June 2007

A matched case-control study was performed to evaluate the risk factors for and outcomes of healthcare-associated infection due to extended-spectrum β-lactamase-producing Escherichia coli or extended-spectrum β-lactamase-producing Klebsiella pneumoniae in Thailand. By multivariable analysis, prior exposure to third-generation cephalosporins and transfer from another hospital were risk factors associated with infection. Receipt of inadequate antimicrobial therapy was a predictor of mortality.
Controlling a Multicenter Outbreak Involving the New York/Japan Methicillin-ResistantStaphylococcus aureusClone
Authors: Coombs G. W. , Van Gessel H. , Pearson J. C. , Godsell M.-R. , O'Brien F. G. , Christiansen K. J.
Published: June 2007

Objective.

To describe the control of an outbreak of infection and colonization with the New York/Japan methicillin-resistantStaphylococcus aureus(MRSA) clone in multiple healthcare facilities, and to demonstrate the importance of making an MRSA management policy involving molecular typing of MRSA into a statewide public health responsibility.

Setting.

A range of healthcare facilities, including 2 metropolitan teaching hospitals and a regional hospital, as well as several community hospitals and long-term care facilities in a nonmetropolitan healthcare region.

Interventions.

A comprehensive, statewide MRSA epidemiological investigation and management policy.

Results.

In May 2005, there were 3 isolates referred to the Western Australian Gram-Positive Bacteria Typing and Research Unit that were identified as the New York/Japan MRSA clone, a pandemic MRSA clone with the ability to spread and replace existing clones in a region. Subsequent investigation identified 28 additional cases of infection and/or colonization dating from 2002 onward, including 1 involving a colonized healthcare worker (HCW) who had previously been hospitalized overseas. Of the 31 isolates detected, 25 were linked epidemiologically and via molecular typing to the isolate recovered from the colonized HCW. Four isolates appeared to have been introduced separately from overseas. Although the isolate from the single remaining case patient was genetically indistinct from the isolates that spread within Western Australia, no specific epidemiological link could be established. The application of standard outbreak management strategies reduced further spread.

Conclusions.

The elimination of the New/York Japan MRSA clone in a healthcare region demonstrates the importance of incorporating MRSA management policy into statewide public health programs. The mainstays of such programs should include a comprehensive and effective outbreak identification and management policy (including pre-employment screening of HCWs, where applicable) and MRSA clone identification by multilocus sequence typing.
Diagnostic Characteristics of Routine Surveillance Cultures of Endotracheal Aspirate Samples in Cases of Late-Onset Ventilator-Associated Pneumonia Due to Acinetobacter baumannii
Authors: Malacarne Paolo , Corini Marzia , Maremmani Paolo , Viaggi Bruno , Verdigi Simone
Published: June 2007

Of 20 consecutive episodes of ventilator-associated pneumonia due to Acinetobacter baumannii, 18 were preceded by tracheobronchial colonization with strains ofA. baumannii that had the same antibiotic susceptibility pattern. When the results of routine surveillance cultures of endotracheal aspirate samples were compared with the results of bronchoalveolar lavage fluid cultures performed for patients who developed late-onset ventilator-associated pneumonia, the sensitivity of the surveillance cultures was 90%, and the negative predictive value was 96%. The positive predictive value of surveillance cultures for identifying causative pathogens in cases of pneumonia due to A. baumannii was good.
Hepatitis B Vaccination Coverage Levels Among Healthcare Workers in the United States, 2002-2003
Authors: Simard Edgar P. , Miller Jeremy T. , George Prethibha A. , Wasley Annemarie , Alter Miriam J. , Bell Beth P. , Finelli Lyn
Published: June 2007

Background.

Hepatitis B virus (HBV) infection is a well recognized risk for healthcare workers (HCWs), and routine vaccination of HCWs has been recommended since 1982. By 1995, the level of vaccination coverage among HCWs was only 67%.

Objective.

To obtain an accurate estimate of hepatitis B vaccination coverage levels among HCWs and to describe the hospital characteristics and hepatitis B vaccination policies associated with various coverage levels.

Design.

Cross-sectional survey.

Methods.

A representative sample of 425 of 6,116 American Hospital Association member hospitals was selected to participate, using probability-proportional-to-size methods during 2002-2003. The data collected included information regarding each hospital's hepatitis B vaccination policies. Vaccination coverage levels were estimated from a systematic sample of 25 HCWs from each hospital whose medical records were reviewed for demographic and vaccination data. The main outcome measure was hepatitis B vaccination coverage levels.

Results.

Among at-risk HCWs, 75% had received 3 or more doses of the hepatitis B vaccine, corresponding to an estimated 2.5 million vaccinated hospital-based HCWs. The coverage level was 81% among staff physicians and nurses. Compared with nurses, coverage was significantly lower among phlebotomists (71.1%) and nurses' aides and/or other patient care staff (70.9%; P < .05). Hepatitis B vaccination coverage was highest among white HCWs (79.5%) and lowest among black HCWs (67.6%; P < .05). Compared with HCWs who worked in hospitals that required vaccination only of HCWs with identified risk for exposure to blood or other potentially infectious material, hepatitis B vaccination coverage was significantly lower among HCWs who worked in hospitals that required vaccination of HCWs without identified risk for exposure to blood or other potentially infectious material (76.6% vs 62.4%; P < .05).

Conclusions.

In the United States, an estimated 75% of HCWs have been vaccinated against hepatitis B. Important differences in coverage levels exist among various demographic groups. Hospitals need to identify methods to improve hepatitis B vaccination coverage levels and should consider developing targeted vaccination programs directed at unvaccinated, at-risk HCWs who have frequent or potential exposure to blood or other potentially infectious material.
Role of Environmental Surveillance in Determining the Risk of Hospital-Acquired Legionellosis: A National Surveillance Study With Clinical Correlations
Authors: Stout Janet E. , Muder Robert R. , Mietzner Sue , Wagener Marilyn M. , Perri Mary Beth , DeRoos Kathleen , Goodrich Dona , Arnold William , Williamson Theresa , Ruark Ola , Treadway Christine , Eckstein Elizabeth C. , Marshall Debra , Rafferty Mary Ellen , Sarro Kathleen , Page Joann , Jenkins Robert , Oda Gina , Shimoda Kathleen J. , Zervos Marcus J. , Bittner Marvin , Camhi Sharon L. , Panwalker Anand P. , Donskey Curtis J. , Nguyen Minh-Hong , Holodniy Mark , Yu Victor L. ,   Legionella Study Group
Published: June 2007

Objective.

Hospital-acquired Legionella pneumonia has a fatality rate of 28%, and the source is the water distribution system. Two prevention strategies have been advocated. One approach to prevention is clinical surveillance for disease without routine environmental monitoring. Another approach recommends environmental monitoring even in the absence of known cases of Legionella pneumonia. We determined the Legionella colonization status of water systems in hospitals to establish whether the results of environmental surveillance correlated with discovery of disease. None of these hospitals had previously experienced endemic hospital-acquired Legionella pneumonia.

Design.

Cohort study.

Setting.

Twenty US hospitals in 13 states.

Interventions.

Hospitals performed clinical and environmental surveillance for Legionella from 2000 through 2002. All specimens were shipped to the Special Pathogens Laboratory at the Veterans Affairs Pittsburgh Medical Center.

Results.

Legionella pneumophila and Legionella anisa were isolated from 14 (70%) of 20 hospital water systems. Of 676 environmental samples, 198 (29%) were positive for Legionella species. High-level colonization of the water system (30% or more of the distal outlets were positive for L. pneumophila) was demonstrated for 6 (43%) of the 14 hospitals with positive findings. L. pneumophila serogroup 1 was detected in 5 of these 6 hospitals, whereas 1 hospital was colonized with L. pneumophila serogroup 5. A total of 633 patients were evaluated for Legionella pneumonia from 12 (60%) of the 20 hospitals: 377 by urinary antigen testing and 577 by sputum culture. Hospital-acquired Legionella pneumonia was identified in 4 hospitals, all of which were hospitals with L. pneumophila serogroup 1 found in 30% or more of the distal outlets. No cases of disease due to other serogroups or species (L. anisa) were identified.

Conclusion.

Environmental monitoring followed by clinical surveillance was successful in uncovering previously unrecognized cases of hospital-acquired Legionella pneumonia.
Regularity of growth and the class 𝒮
Authors: Drasin D.
Published: June 2007

Given

1

/

2
≤
μ
≤
ρ
≤
∞

1/2\leq \mu \leq \rho \leq \infty

, there is an entire function

f
(
z
)

f(z)

in the Speiser class

S

\mathcal {S}

of order

ρ
\rho

, lower order

μ
\mu

.

f
f

may have as few as three singular values.