bluuebunny/crossref_metadata_2025 huggingface dataset:
Enterobacteriaceae
Bloodstream Infections: Presence of Integrons, Risk Factors, and Outcome
Authors: Daikos George L. , Kosmidis Chris , Tassios Panayotis T. , Petrikkos George , Vasilakopoulou Alexandra , Psychogiou Mina , Stefanou Ioanna , Avlami Athina , Katsilambros Nikolaos
Published: April 2007

A prospective observational study was conducted to identify factors associated with bloodstream infections (BSIs) caused by integron-carrying
Enterobacteriaceae
and to evaluate the clinical significance of integron carriage. Consecutive patients with
Enterobacteriaceae
BSIs were identified and followed up until discharge or death. Identification of blood isolates and susceptibility testing were performed by the Wider I automated system.
int-1
-specific PCR, conserved-segment PCR, and DNA sequencing were used to determine the presence, length, and content of integrons. The relatedness among the isolates was examined by pulsed-field gel electrophoresis. Two hundred fifty episodes of
Enterobacteriaceae
BSI occurred in 233 patients; 109 (43.6%) were nosocomial, 82 (32.8%) were community acquired, and 59 (23.6%) were health care associated. Integrons were detected in 11 (13.4%) community-acquired, 24 (40.7%) health care-associated, and 46 (42.2%) nosocomial isolates. Integron-carrying organisms were more likely to exhibit resistance to three or more classes of antimicrobials (odds ratio [OR], 9.84; 95% confidence interval [95% CI], 5.31 to 18.23;
P
< 0.001) or to produce extended-spectrum β-lactamases (OR, 5.75; 95% CI, 2.38 to 13.89;
P
< 0.001) or a VIM-type metallo-β-lactamase (
P
, 0.003). Inter- or intraspecies integron transfer and cross-transmission of integron-carrying clones were observed. Use of cotrimoxazole (OR, 4.77; 95% CI, 1.81 to 12.54;
P
< 0.001) and a nosocomial or other health care setting (OR, 3.07; 95% CI, 1.30 to 7.22;
P
, 0.01) were independently associated with BSIs caused by integron-carrying
Enterobacteriaceae
. Patients with a nonurinary source of bacteremia (OR, 9.46; 95% CI, 2.77 to 32.32;
P
< 0.001) and a Pitt bacteremia score of ≥4 (OR, 23.36; 95% CI, 7.97 to 68.44;
P
< 0.001) had a significantly higher 14-day mortality rate, whereas integron carriage did not affect clinical outcomes. These findings may have implications affecting antibiotic policies and infection control measures.
Modular Structure of Microcin H47 and Colicin V
Authors: Azpiroz María F. , Laviña Magela
Published: April 2007

Microcins are gene-encoded peptide antibiotics produced by enterobacteria that act on strains of gram-negative bacteria. In this work, we concentrated on higher-molecular-mass microcins, i.e., those possessing 60 or more amino acids. They can be subdivided into unmodified and posttranslationally modified peptides. In both cases, they exhibit conserved C-terminal sequences that appear to be characteristic of each subgroup. In the hypothesis that these sequences could correspond to domains, gene fusions between the activity genes for the unmodified microcin colicin V and the modified microcin H47 were constructed. These two microcins differ in their mode of synthesis, uptake, target, and specific immunity. Through this experimental approach, chimeric peptides with exchanged C-terminal sequences were encoded. Cells carrying the fusions in different genetic contexts were then assayed for antibiotic production. Many of them produced antibiotic activities with recombinant properties: the toxicity of one microcin and the mode of uptake of the other. The results led to the identification of a modular structure of colicin V and microcin H47, with the recognition of two domains in their peptide chains: a toxic N-terminal domain and an uptake C-terminal domain. This modular design would be shared by other microcins from each subgroup.
Human Monoclonal Antibody AVP-21D9 to Protective Antigen Reduces Dissemination of the
Bacillus anthracis
Ames Strain from the Lungs in a Rabbit Model
Authors: Peterson Johnny W. , Comer Jason E. , Baze Wallace B. , Noffsinger David M. , Wenglikowski Autumn , Walberg Kristin G. , Hardcastle Jason , Pawlik Jennifer , Bush Kathryn , Taormina Joanna , Moen Scott , Thomas John , Chatuev Bagram M. , Sower Laurie , Chopra Ashok K. , Stanberry Lawrence R. , Sawada Ritsuko , Scholz Wolfgang W. , Sircar Jagadish
Published: April 2007

Dutch-belted and New Zealand White rabbits were passively immunized with AVP-21D9, a human monoclonal antibody to protective antigen (PA), at the time of
Bacillus anthracis
spore challenge using either nasal instillation or aerosol challenge techniques. AVP-21D9 (10 mg/kg) completely protected both rabbit strains against lethal infection with
Bacillus anthracis
Ames spores, regardless of the inoculation method. Further, all but one of the passively immunized animals (23/24) were completely resistant to rechallenge with spores by either respiratory challenge method at 5 weeks after primary challenge. Analysis of the sera at 5 weeks after primary challenge showed that residual human anti-PA levels decreased by 85 to 95%, but low titers of rabbit-specific anti-PA titers were also measured. Both sources of anti-PA could have contributed to protection from rechallenge. In a subsequent study, bacteriological and histopathology analyses revealed that
B. anthracis
disseminated to the bloodstream in some naïve animals as early as 24 h postchallenge and increased in frequency with time. AVP-21D9 significantly reduced the dissemination of the bacteria to the bloodstream and to various organs following infection. Examination of tissue sections from infected control animals, stained with hematoxylin-eosin and the Gram stain, showed edema and/or hemorrhage in the lungs and the presence of bacteria in mediastinal lymph nodes, with necrosis and inflammation. Tissue sections from infected rabbits dosed with AVP-21D9 appeared comparable to corresponding tissues from uninfected animals despite lethal challenge with
B. anthracis
Ames spores. Concomitant treatment with AVP-21D9 at the time of challenge conferred complete protection in the rabbit inhalation anthrax model. Early treatment increased the efficacy progressively and in a dose-dependent manner. Thus, AVP-21D9 could offer an adjunct or alternative clinical treatment regimen against inhalation anthrax.
Dynamics in Prophage Content of Invasive and Noninvasive M1 and M28
Streptococcus pyogenes
Isolates in The Netherlands from 1959 to 1996
Authors: Vlaminckx Bart J. M. , Schuren Frank H. J. , Montijn Roy C. , Caspers Martien P. M. , Beitsma M. M. , Wannet Wim J. B. , Schouls Leo M. , Verhoef Jan , Jansen Wouter T. M.
Published: April 2007

Invasive group A streptococcal (GAS) disease reemerged in The Netherlands in the late 1980s. To seek an explanation for this resurgence, the genetic compositions of 22 M1 and 19 M28 GAS strains isolated in The Netherlands between 1960s and the mid-1990s were analyzed by using a mixed-genome DNA microarray. During this four-decade period, M1 and especially M28 strains acquired prophages on at least eight occasions. All prophages carried a superantigen (s
peA2
,
spe
C,
spe
K) or a streptodornase (
sdaD2
,
sdn
), both associated with invasive GAS disease. Invasive and noninvasive GAS strains did not differ in prophage acquisition, suggesting that there was an overall increase in the pathogenicity of M1 and M28 strains over the last four decades rather than emergence of hypervirulent subclones. The increased overall pathogenic potential may have contributed to the reemergence of invasive GAS disease in The Netherlands.
Synthesis, Characterization and Catalytic Utilization of a Ferrocene Diamidodiphosphane
Authors: Štěpnička Petr , Schulz Jiří , Císařová Ivana , Fejfarová Karla
Published: April 2007

Amidation of 1'-(diphenylphosphanyl)ferrocene-1-carboxylic acid (Hdpf) with ethane-1,2-diamine afforded N,N'-ethylenebis[1'-(diphenylphosphanyl)ferrocene-1-carboxamide] (1), which was isolated in free and solvated form, 1·2AcOH. Both 1 and Hdpf were further converted to their respective phosphane sulfides, 2·2AcOH and 3 that were structurally characterized. Testing of the amidophosphane ligands in Suzuki-Miyaura cross-coupling reaction between phenylboronic acid and various aryl halides revealed that catalyst formed in situ from 1 and palladium(II) acetate is highly active in coupling reactions of aryl bromides whilst the corresponding aryl chlorides showed no or only poor conversions. The catalyst based on 2·2AcOH gave markedly lower yields of the coupling products.
APPLICATIONS OF GOLD NANOPARTICLES IN THE EARLY DETECTION OF CANCER
Authors: KHO KIANG WEI , KAH JAMES CHEN YONG , LEE CAROLINE GUAT LENG , SHEPPARD COLLIN JAMES RICHARD , SHEN ZE XIANG , SOO KHEE CHEE , OLIVO MALINI CAROLENE
Published: April 2007

Worldwide, oral cancer is the sixth most common cancer for both sexes. In Singapore, the 5-year survival rate of oral cancer is about 50%. The high mortality rate has been attributed to the difficulties in detecting the disease in an early treatable stage. Here, we present two application examples of gold nanoparticles in the early detection of oral cancer. In the first, gold nanoparticles were used as a reflective contrast agent for performing molecular imaging under confocal reflectance microscopy for the early diagnosis of epithelial carcinoma. While in the second, closely-packed gold nanoparticle, films were used as a bio-sensing surface for the chemical analysis of saliva via Surface Enhanced Raman Scattering. Preliminary results will be discussed.
ORTHOPEDIC SURGERY TRAINING SIMULATION
Authors: SOURINA OLGA , SOURIN ALEXEI , SEN HOWE TET
Published: April 2007

Surgical training is one of the most promising areas in medicine where 3-D computer graphics and virtual reality techniques are emerging. Orthopedic surgery is a discipline requiring appreciation and understanding of complex 3-dimensional bony structures and their relationships to nerves, blood vessels and other vital structures. Learning these spatial skills requires a lengthy period and much practice. In this paper, we present a software simulator which was developed to aid in the understanding of the complex 3-dimensional relationships between bones and implants. The developed software cuts down the learning curve and allows for better and more precise surgery by letting the surgeon practice the surgery in a virtual environment before undertaking the actual procedure.
MANUFACTURING AND NEAR-PHYSIOLOGICAL TESTING OF A BIODEGRADABLE METALLIC CORONARY STENT (BMCS)
Authors: LIM C. S. , YONG J. , TOH K. M.
Published: April 2007

Permanent metallic stents are frequently used in cardiovascular interventions, due to the many advantages metals possess in bulk and surface properties, design and chemistry, as well as their high modulus and ease of producing thin sections. However, the presence of foreign bodies in humans is associated with many long-term safety concerns; removal of the stent is therefore preferred through a second intervention after recovery. Based primarily on this consideration, biodegradable stents have been of significant interest in the past few years. This paper reports the manufacturing and near-physiological testing of a novel Biodegradable Metallic Coronary Stent (BMCS). To date, very limited literature is available on this aspect of research. Generally, magnesium is reactive and generally difficult to process. However, preliminary results demonstrate strong feasibility of fabricating low-profiled magnesium-based biodegradable coronary stents. Near-physiological tests based on a specially designed accelerated radial stent fatigue system were carried out. Results show that the biodegradable stents retained their arterial scaffolding functions for up to one year (simulated) before totally being resorbed into the biological fluid past its point of functionality. The results obtained so far show great promise for application.
Comparative genomic analysis of a mammalian β-defensin gene cluster
Authors: Radhakrishnan Yashwanth , Fares Mario A. , French Frank S. , Hall Susan H.
Published: April 2007

Comparative genomic analyses have yielded valuable insights into conserved and divergent aspects of gene function, regulation, and evolution. Herein, we describe the characterization of a mouse β-defensin gene cluster locus on chromosome 2F6. In addition, we present the evolutionary analysis of this cluster and its human, rhesus, and rat orthologs. Expression analysis in mouse revealed the occurrence of defensin cluster transcripts in multiple tissues, with the highest abundance in the urogenital tract. Molecular evolutionary analysis suggests that this cluster originated by a series of duplication events, and by positive selection occurring even after the rodent-primate split. In addition, the constraints analysis showed higher positive selection in rodents than in primates, especially distal to the six-cysteine array. Positive selection in the evolution of these defensins may relate not only to the evolving enhancement of ancestral host defense but also to functional innovations in reproduction. The multiplicity of defensins and their preferential overexpression in the urogenital tract indicate that defensins function in the protection and maintenance of fertility.
Incremental Benefit and Cost-Effectiveness of High-Dose Statin Therapy in High-Risk Patients With Coronary Artery Disease
Authors: Chan Paul S. , Nallamothu Brahmajee K. , Gurm Hitinder S. , Hayward Rodney A. , Vijan Sandeep
Published: April 2007

Background—

Recent clinical trials found that high-dose statin therapy, compared with conventional-dose statin therapy, reduces the risk of cardiovascular events in patients with acute coronary syndromes (ACS) and stable coronary artery disease (CAD). However, the actual benefit and cost-effectiveness of high-dose statin therapy are unknown.

Methods and Results—

We designed a Markov model to compare daily high-dose with conventional-dose statin therapy for hypothetical 60-year-old cohorts with ACS and stable CAD over patient lifetime. Pooled estimates for major clinical end points (all-cause mortality, myocardial infarction, stroke, rehospitalization, and revascularization) from relevant clinical trials were incorporated. Incremental benefit was quantified as quality-adjusted life-years (QALYs). Threshold analyses determined at what price difference high-dose statins would yield incremental cost-effective ratios below $50 000, $100 000, and $150 000 per QALY gained. In ACS patients, a high-dose versus conventional-dose statin strategy resulted in a gain of 0.35 QALYs. In threshold analyses, a high-dose statin strategy consistently yielded incremental cost-effective ratios below $30 000 per QALY even under conservative model assumptions. In stable CAD patients, a high-dose statin strategy yielded a gain of only 0.10 QALYs and was sensitive to model assumptions about statin efficacy. The daily cost difference between a high- and conventional-dose statin would need to be <$1.70, $2.65, and $3.55 to yield incremental cost-effective ratios below $50 000, $100 000, and $150 000 per QALY.

Conclusions—

High-dose statin therapy is potentially highly effective and cost-effective in patients with ACS. In patients with stable CAD, however, the cost-effectiveness of high-dose statin therapy is highly sensitive to model assumptions about statin efficacy and cost. Use of high-dose statins can be supported on health economic grounds in patients with ACS, but the case is less clear for patients with stable CAD.
Brachial Flow-Mediated Dilation Predicts Incident Cardiovascular Events in Older Adults
Authors: Yeboah Joseph , Crouse John R. , Hsu Fang-Chi , Burke Gregory L. , Herrington David M.
Published: April 2007

Background—

The relationship between impaired brachial flow-mediated dilation (FMD) and subsequent clinical cardiovascular events is not well established, especially in older adults whose FMD is often diminished. We assessed the hypothesis that FMD predicts incident cardiovascular events in a population-based cohort of older adults.

Methods and Results—

FMD was measured at the 1997 to 1998 Cardiovascular Health Study clinic visit in 2792 adults aged 72 to 98 years (82.7% white, 58.6% women) recruited at 4 clinic sites in the United States. Log-rank test and Cox proportional hazard models were used to examine the association between FMD and adjudicated cardiovascular events. A total of 674 subjects (24.1%) had an adjudicated event over the 5-year follow-up period. Event-free survival rates for cardiovascular events were significantly higher in subjects with FMD greater than the sex-specific medians than in subjects with FMD less than or equal to the sex-specific medians (78.3% versus 73.6%, log-rank
P
=0.006). FMD remained a significant predictor of cardiovascular events after adjustment for age, gender, diabetes mellitus, cigarette smoking, systolic and diastolic blood pressure, baseline cardiovascular disease status, and total cholesterol (hazard ratio, 0.91 [95% CI, 0.83 to 0.99],
P
=0.02 per unit SD of FMD) but added only ≈1% to the prognostic accuracy of the best Cox model. Brachial artery diameter was also predictive of CV events in the adjusted Cox proportional hazard model (hazard ratio, 1.12 [95% CI, 1.02 to 1.28],
P
=0.025) and also added ≈1% to the accuracy of our best Cox model.

Conclusions—

FMD is a predictor of future cardiovascular events but adds very little to the prognostic accuracy of traditional cardiovascular risk scores/factors in older adults. FMD and brachial artery diameter may have similar predictive values for cardiovascular events in older adults.
Hypoadiponectinemia as a Predictor for the Development of Hypertension
Authors: Chow Wing-Sun , Cheung Bernard M.Y. , Tso Annette W.K. , Xu Aimin , Wat Nelson M.S. , Fong Carol H.Y. , Ong Liza H.Y. , Tam Sidney , Tan Kathryn C.B. , Janus Edward D. , Lam Tai-Hing , Lam Karen S.L.
Published: April 2007

Low circulating levels of adiponectin, an adipokine with insulin-sensitizing, antiatherogenic, and anti-inflammatory properties, are found in hypertensive patients. Adiponectin replenishment ameliorated hypertension in adiponectin-deficient mice or obese, hypertensive mice with hypoadiponectinemia, suggesting an etiologic role of adiponectin in hypertension. We aimed to determine, in this 5-year prospective study, whether hypoadiponectinemia could predict the development of hypertension in a nondiabetic Chinese cohort. A total of 577 subjects (249 men and 328 women) were recruited from the population-based Hong Kong Cardiovascular Risk Factor Prevalence Study and prospectively followed up for 5 years. The relationship of serum adiponectin with the development of hypertension (sitting blood pressure ≥140/90 mm Hg) was investigated in a nested case–control study consisting of 70 subjects who had developed hypertension on follow-up and 140 age- and sex-matched control subjects who were normotensive both at baseline and at year 5. At baseline, serum adiponectin level in the lowest sex-specific tertile was more likely to be associated with hypertension (
P
=0.003 versus the highest tertile, after adjusting for age, body mass index, fasting insulin, and high-sensitivity C-reactive protein). At year 5, baseline serum adiponectin was a significant independent predictor of incident hypertension in the nested case–control study (
P
=0.015; age adjusted), together with mean arterial pressure (
P
<0.001), high-sensitivity C-reactive protein (
P
=0.018), and body mass index (
P
=0.004). Normotensive subjects with baseline serum adiponectin levels in the lowest sex-specific tertile had an increased risk of becoming hypertensive (adjusted odds ratio: 2.76; 95% CIs: 1.06 to 7.16;
P
=0.037 versus highest tertile). Our data suggest that hypoadiponectinaemia may be involved in the pathogenesis of hypertension in humans.
Synergism between the Low-Level Jet and Organized Convection at Its Exit Region
Authors: Saulo Celeste , Ruiz Juan , Skabar Yanina García
Published: April 2007

Previous studies suggest that the enhanced meridional extent of some South American low-level jet events (known as Chaco jets) is a consequence of a positive feedback between the low-level wind and strong convection that is usually observed at their exit region. To assess how this interaction takes place, a Chaco low-level jet event observed between 18 and 19 December 2002 (i.e., during the South America Low-Level Jet Experiment) and the associated mesoscale convective system that evolved at its exit region have been selected to perform numerical experiments where diabatic heating effects associated with phase changes can be quantified. This case study has also been used to analyze the diurnal oscillations related to planetary boundary layer (PBL) mechanisms in order to describe whether the observed evolution of the low-level wind can be explained either by PBL-related forcing or by the interaction with convection. The sensitivity experiments confirm that there is a positive feedback at low levels between convection and the northerly wind flow that becomes accelerated and also aids in the identification of a strong coupling between organized convection and the upper-level circulation, resulting in an increase of the upper-level jet strength downstream of the simulated precipitation area. A conceptual model of how these systems (i.e., convection, low- and upper-level jets) mutually interact is proposed, which differs from coupling mechanisms documented for the Great Plains low-level jet.
Meso-β-scale Pressure Dips Associated with Typhoons
Authors: Fudeyasu Hironori , Iizuka Satoshi , Hayashi Taiichi
Published: April 2007

Using a mesoscale model, the formation process of a pressure dip, which was characterized by a rapid decrease and subsequent increase in surface pressure lasting less than an hour, was investigated. A simulated pressure dip accompanied by Typhoon Zeb was closely related to warm potential temperature anomalies in the lower troposphere. As the typhoon moved into the midlatitude westerlies, the inflow of a dry air mass into the moist region of the typhoon occurred to the west of the typhoon center. Then, a downdraft developed due to evaporation and sublimation. Below the melting levels where there were fewer hydrometeors, however, evaporation was insufficient to offset the adiabatic warming. As a result, warm potential temperature anomalies were created in the lower level, resulting in the formation of a pressure dip. The features of a pressure dip associated with other typhoons observed over Japan were also examined. The features were summarized as follows: 1) the pressure dip was observed only on the western side of the typhoon center at a distance of 50–300 km from the center, 2) the pressure dip was accompanied by a sudden cessation of rainfall, and 3) all typhoons with a pressure dip were found during boreal autumn when large-scale environmental conditions were characterized by westerlies with a trough and a dry air mass to the west of Japan at upper levels and fronts at lower levels. The formation process of the simulated pressure dip in other typhoons was found to be similar to that of Typhoon Zeb. The present study suggests that pressure dip is an inherent feature of the asymmetric structure of a typhoon undergoing transition to a extratropical cyclone.
Comparison of Narrow Bipolar Events with Ordinary Lightning as Proxies for the Microwave-Radiometry Ice-Scattering Signature
Authors: Jacobson Abram R. , Boeck William , Jeffery Christopher
Published: April 2007

The narrow bipolar event (NBE) is a unique lightning discharge that has a short (∼10 μs) overall duration, lacks a prior leader phase, and produces too little light output to be visible by optical lightning detectors on satellites. NBEs thus have basic differences from ordinary lightning discharges, which occur in flashes lasting up to a fraction of a second, carry significant current in a “stroke” only after a leader stage that prepares the conductive channel, and produce copious light that is recordable from space. Thus, the authors are motivated to determine whether the meteorological setting of NBEs differs from, or is similar to, that of ordinary lightning. A previous paper started this project of comparing NBEs with ordinary lightning by comparing the placement of either type of lightning within spatial structures of cloud depth, as revealed by infrared cloud-top temperature. That previous study employed lightning data from the Los Alamos Sferic Array (LASA) in Florida. The present paper extends this approach to comparing LASA NBEs with ordinary lightning events’ spatial relationships to radiometric cloud imagery from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) 85-GHz channels. This form of radiometric imagery reveals the location of deep, active convective cores with more acute spatial selectivity than does the infrared cloud-top temperature. It was found that the behaviors of NBEs and ordinary lighting are, once again, indistinguishable, but with regard this time to proximity to deep convective cores as revealed by TMI.
Calibrated Surface Temperature Forecasts from the Canadian Ensemble Prediction System Using Bayesian Model Averaging
Authors: Wilson Laurence J. , Beauregard Stephane , Raftery Adrian E. , Verret Richard
Published: April 2007

Bayesian model averaging (BMA) has recently been proposed as a way of correcting underdispersion in ensemble forecasts. BMA is a standard statistical procedure for combining predictive distributions from different sources. The output of BMA is a probability density function (pdf), which is a weighted average of pdfs centered on the bias-corrected forecasts. The BMA weights reflect the relative contributions of the component models to the predictive skill over a training sample. The variance of the BMA pdf is made up of two components, the between-model variance, and the within-model error variance, both estimated from the training sample. This paper describes the results of experiments with BMA to calibrate surface temperature forecasts from the 16-member Canadian ensemble system. Using one year of ensemble forecasts, BMA was applied for different training periods ranging from 25 to 80 days. The method was trained on the most recent forecast period, then applied to the next day’s forecasts as an independent sample. This process was repeated through the year, and forecast quality was evaluated using rank histograms, the continuous rank probability score, and the continuous rank probability skill score. An examination of the BMA weights provided a useful comparative evaluation of the component models, both for the ensemble itself and for the ensemble augmented with the unperturbed control forecast and the higher-resolution deterministic forecast. Training periods around 40 days provided a good calibration of the ensemble dispersion. Both full regression and simple bias-correction methods worked well to correct the bias, except that the full regression failed to completely remove seasonal trend biases in spring and fall. Simple correction of the bias was sufficient to produce positive forecast skill out to 10 days with respect to climatology, which was improved by the BMA. The addition of the control forecast and the full-resolution model forecast to the ensemble produced modest improvement in the forecasts for ranges out to about 7 days. Finally, BMA produced significantly narrower 90% prediction intervals compared to a simple Gaussian bias correction, while achieving similar overall accuracy.
Tests of an Ensemble Kalman Filter for Mesoscale and Regional-Scale Data Assimilation. Part II: Imperfect Model Experiments
Authors: Meng Zhiyong , Zhang Fuqing
Published: April 2007

In Part I of this two-part work, the feasibility of using an ensemble Kalman filter (EnKF) for mesoscale and regional-scale data assimilation through various observing system simulation experiments was demonstrated assuming a perfect forecast model for a winter snowstorm event that occurred on 24–26 January 2000. The current study seeks to explore the performance of the EnKF for the same event in the presence of significant model errors due to physical parameterizations by assimilating synthetic sounding and surface observations with typical temporal and spatial resolutions. The EnKF performance with imperfect models is also examined for a warm-season mesoscale convective vortex (MCV) event that occurred on 10–13 June 2003. The significance of model error in both warm- and cold-season events is demonstrated when the use of different cumulus parameterization schemes within different ensembles results in significantly different forecasts in terms of both ensemble mean and spread. Nevertheless, the EnKF performed reasonably well in most experiments with the imperfect model assumption (though its performance can sometimes be significantly degraded). As in Part I, where the perfect model assumption was utilized, most analysis error reduction comes from larger scales. Results show that using a combination of different physical parameterization schemes in the ensemble forecast can significantly improve filter performance. A multischeme ensemble has the potential to provide better background error covariance estimation and a smaller ensemble bias. There are noticeable differences in the performance of the EnKF for different flow regimes. In the imperfect scenarios considered, the improvement over the reference ensembles (pure ensemble forecasts without data assimilation) after 24 h of assimilation for the winter snowstorm event ranges from 36% to 67%. This is higher than the 26%–45% improvement noted after 36 h of assimilation for the warm-season MCV event. Scale- and flow-dependent error growth dynamics and predictability are possible causes for the differences in improvement. Compared to the power spectrum analyses for the snowstorm, it is found that forecast errors and ensemble spreads in the warm-season MCV event have relatively smaller power at larger scales and an overall smaller growth rate.
Environmental Control of Cloud-to-Ground Lightning Polarity in Severe Storms
Authors: Carey Lawrence D. , Buffalo Kurt M.
Published: April 2007

In this study, it is hypothesized that the mesoscale environment can indirectly control the cloud-to-ground (CG) lightning polarity of severe storms by directly affecting their structural, dynamical, and microphysical properties, which in turn directly control cloud electrification and ground flash polarity. A more specific hypothesis, which has been supported by past observational and laboratory charging studies, suggests that broad, strong updrafts and associated large liquid water contents in severe storms lead to the generation of an inverted charge structure and enhanced +CG lightning production. The corollary is that environmental conditions favoring these kinematic and microphysical characteristics should support severe storms generating an anomalously high (>25%) percentage of +CG lightning (i.e., positive storms) while environmental conditions relatively less favorable should sustain storms characterized by a typical (≤25%) percentage of +CG lightning (i.e., negative storms). Forty-eight inflow proximity soundings were analyzed to characterize the environment of nine distinct mesoscale regions of severe storms (4 positive and 5 negative) on 6 days during May–June 2002 over the central United States. This analysis clearly demonstrated significant and systematic differences in the mesoscale environments of positive and negative storms, which were consistent with the stated hypothesis. When compared to negative storms, positive storms occurred in environments associated with a drier low to midtroposphere, higher cloud-base height, smaller warm cloud depth, stronger conditional instability, larger 0–3 km AGL wind shear, stronger 0–2 km AGL storm relative wind speed, and larger buoyancy in the mixed-phase zone, at a statistically significant level. Differences in the warm cloud depth of positive and negative storms were by far the most dramatic, suggesting an important role for this parameter in controlling CG lightning polarity. In this study, strong correlations between the mesoscale environment and CG lightning polarity were demonstrated. However, causality could not be verified due to a lack of in situ observations to confirm the hypothesized microphysical, dynamical, and electrical responses to variations in environmental conditions that ultimately determined the dominant CG polarity. Future observational field programs and cloud modeling studies should focus on these critical intermediary processes.
Theory and Applications of the Minimum Spanning Tree Rank Histogram
Authors: Gombos Daniel , Hansen James A. , Du Jun , McQueen Jeff
Published: April 2007

A minimum spanning tree (MST) rank histogram (RH) is a multidimensional ensemble reliability verification tool. The construction of debiased, decorrelated, and covariance-homogenized MST RHs is described. Experiments using Euclidean L2, variance, and Mahalanobis norms imply that, unless the number of ensemble members is less than or equal to the number of dimensions being verified, the Mahalanobis norm transforms the problem into a space where ensemble imperfections are most readily identified. Short-Range Ensemble Forecast Mahalanobis-normed MST RHs for a cluster of northeastern U.S. cities show that forecasts of the temperature–humidity index are the most reliable of those considered, followed by mean sea level pressure, 2-m temperature, and 10-m wind speed forecasts. MST RHs of a Southwest city cluster illustrate that 2-m temperature forecasts are the most reliable weather component in this region, followed by mean sea level pressure, 10-m wind speed, and the temperature–humidity index. Forecast reliabilities of the Southwest city cluster are generally less reliable than those of the Northeast cluster.
Scoring Probabilistic Forecasts: The Importance of Being Proper
Authors: Bröcker Jochen , Smith Leonard A.
Published: April 2007

Questions remain regarding how the skill of operational probabilistic forecasts is most usefully evaluated or compared, even though probability forecasts have been a long-standing aim in meteorological forecasting. This paper explains the importance of employing proper scores when selecting between the various measures of forecast skill. It is demonstrated that only proper scores provide internally consistent evaluations of probability forecasts, justifying the focus on proper scores independent of any attempt to influence the behavior of a forecaster. Another property of scores (i.e., locality) is discussed. Several scores are examined in this light. There is, effectively, only one proper, local score for probability forecasts of a continuous variable. It is also noted that operational needs of weather forecasts suggest that the current concept of a score may be too narrow; a possible generalization is motivated and discussed in the context of propriety and locality.
Application of Artificial Neural Network Forecasts to Predict Fog at Canberra International Airport
Authors: Fabbian Dustin , de Dear Richard , Lellyett Stephen
Published: April 2007

The occurrence of fog can significantly impact air transport operations, and plays an important role in aviation safety. The economic value of aviation forecasts for Sydney Airport alone in 1993 was estimated at $6.8 million (Australian dollars) for Quantas Airways. The prediction of fog remains difficult despite improvements in numerical weather prediction guidance and models of the fog phenomenon. This paper assesses the ability of artificial neural networks (ANNs) to provide accurate forecasts of such events at Canberra International Airport (YSCB). Unlike conventional statistical techniques, ANNs are well suited to problems involving complex nonlinear interactions and therefore have potential in application to fog prediction. A 44-yr database of standard meteorological observations obtained from the Australian Bureau of Meteorology was used to develop, train, test, and validate ANNs designed to predict fog occurrence. Fog forecasting aids were developed for 3-, 6-, 12-, and 18-h lead times from 0600 local standard time. The forecasting skill of various ANN architectures was assessed through analysis of relative operating characteristic curves. Results indicate that ANNs are able to offer good discrimination ability at all four lead times. The results were robust to error perturbation for various input parameters. It is recommended that such models be included when preparing forecasts for YSCB, and that the technique should be extended in its application to cover other similarly fog-prone aviation locations.
A Western Australian Survey On Public Attitudes Toward and Knowledge of Electroconvulsive Therapy
Authors: Teh Serene P.C. , Helmes Edward , Drake Deirdre G.
Published: April 2007

Aims: Healthcare professionals have debated the use and effects of electroconvulsive therapy (ECT) for more than 65 years. Yet, knowledge about, and attitudes towards, ECT have not been thoroughly researched within the Australian community. This study focused on a Western Australian perspective on these issues.

Method: The objectives were achieved with specifically developed questionnaires. Six hundred surveys were distributed across the metropolitan area of Perth, Australia.

Results: A total of 379 completed questionnaires indicated that more than 60% of respondents had some knowledge about the main aspects of ECT. Participants were generally opposed to the use of ECT on individuals with psychosocial issues, on children and on involuntary patients. Public perceptions of ECT were also found to be mainly negative.

Conclusion: The findings suggest that clinicians should ensure that individuals recommended for ECT are knowledgeable about basic ECT processes and implications in order to ensure their full informed consent.
Factors Influencing Attitudes Towards Seeking Professional Help Among East and Southeast Asian Immigrant and Refugee Women
Authors: Fung Kenneth , Wong Yuk-Lin Renita
Published: April 2007

Background and aims: It has been recognized that Asian immigrants in North America have lower rates of mental health service utilization. From the perspective of cross-cultural psychiatry, one of the most important cultural factors may be differences in the explanatory model of illness. This article examines the relationship of causal beliefs, perceived service accessibility and attitudes towards seeking mental health care.

Method: The sample consisted of 1000 immigrant and refugee women from five ethnic minority communities in Toronto, including three Chinese Canadian communities (Hong Kong, mainland China and Taiwan), Korean Canadians and Vietnamese Canadians. Data were acquired by a self-administered structured questionnaire. Quantitative data were analysed using MANOVA, ANOVA and stepwise multiple regression.

Results: The five ethnic minority groups of women differed in their explanatory models about mental illness and distress. In the full model where other variables were controlled for, the most significant factor predicting attitudes towards seeking professional help was perceived access for all groups except the Hong Kong Chinese. In the last group, those subscribing more to a Western stress model of illness had a more positive attitude towards seeking professional help, while those subscribing more to supernatural beliefs had a more negative attitude. Age and education were not significant predictors.

Conclusion: Perceived access is one of the main factors that influence attitudes toward seeking professional help. Explanatory models may predict help-seeking behaviours if perceived access to such services is available.
Psychological Distress in Caretakers or Relatives of Patients With Borderline Personality Disorder
Authors: Scheirs J.G.M. , Bok S.
Published: April 2007

Background and aims: Caregivers or relatives of mental patients often show increased levels of psychological distress. This study investigated whether this is also the case for caregivers of patients with borderline personality disorder.

Methods: The Symptom Check List (SCL-90) was administered to 64 Dutch volunteers, who were either biologically related (parents or siblings) or biologically unrelated caregivers (partners or friends) of patients with borderline personality disorder.

Results: The group of caregivers as a whole scored higher on all symptom dimensions of the SCL-90 than the general population. When controlling for caregiver sex and age, as well as for patient sex, there were no significant differences between the biologically related and unrelated caregiver groups on any dimension.

Conclusions: The results are in line with findings concerning distress in caregivers of patients suffering from personality disorders in general, posttraumatic stress disorder or schizophrenia. The mechanism behind the increased levels of distress in our sample is not clear, however. Either exposure to the problematic behaviour of the patient, selective mating or a combination of both might have been responsible for the effect.
Borderline Personality Disorder: Neo-Personality Inventory Ratings of Patients and Their Family Members
Authors: Hoffman Perry D. , Buteau Ellie , Fruzzetti Alan E.
Published: April 2007

Borderline personality disorder (BPD) is hallmarked by interpersonal problems. Conflicts with family members are no exception.

Methods: The NEO-Personality Inventory was administered to 25 pairs of patients and their family members. Both completed the questionnaire twice, responding about their own personality traits and responding about personality traits of the other.

Results: Patients and family members agreed on all five of the patient's personality traits. However, patients perceived the family members as being more neurotic, less extraverted and less open than the family members perceived themselves.

Conclusions: Discrepant perceptions of personality traits `may' create different relationship expectations and thus contribute to and intensify interpersonal difficulties.
The Import-Substitution Model
Authors: Silva Eduardo
Published: April 2007

The standard characterization of Latin America's import-substitution model of development and its “failure” overlooks two important issues. First, models of development do not spring forth full-blown with self-evident virtues or fatal flaws as politicized public policy analysts claim. They emerge over time as responses to international and domestic socioeconomic and political crises. They spring from attempts to restore economic growth and political order and are later formalized as models. In that sense, import-substitution industrialization had significant success for a number of decades. Secondly, given Latin America's situation of dependency, international economic crises before and after World War II and the characteristics of the world capitalist economy that emerged after the war had a significant impact on the rise and fall of import-substitution industrialization. However, there was considerable variation in the timing and sequencing of this impact and the extent to which these international factors affected the rise and fall of the model in Chile, Argentina, Mexico, and Brazil. Differences in domestic factors, such as state formation, party systems, and the social coalitions that supported and opposed import-substitution industrialization, account for that variation. Moreover, the decline of the model should be understood in terms of the degree of departure from industrial policy and inclusive social policy, not in terms of some intrinsic incapacity.
Noise levels and noise sources in acute care hospital wards
Authors: MacKenzie D.J. , Galbrun L.
Published: April 2007

Noise in hospital wards has the potential to slow down the recovery of patients. A comprehensive and systematic analysis of noise levels and noise sources has been carried out in two intensive care units and one high dependency unit in two Edinburgh hospitals (UK). Noise levels LAeq,1min and LAFmax were measured at 1 minute intervals for 24 hour periods, and noise sources responsible for LAFmax were identified. High noise levels were found in the three wards, the lowest LAeq,1min being measured in the modern ward tested, where an acoustic ceiling was present. A substantial number of noise sources have been observed and analysed statistically, many of which had never been identified by previous research. It was found that 34% of these are totally avoidable and 28% are partially avoidable. Noise control solutions are presented, with practical solutions affecting 48% of the noise sources, and staff education affecting 14% of the sources.

Practical application: The analysis and classification of noise sources obtained has lead to the identification and presentation of practical noise control solutions, some of which can be implemented at the design stage. This is of direct relevance to building services engineers who play a role in the design of hospital wards, and can therefore use this information.

It can also be noted that average and maximum noise levels measured in this study could form the basis for the development of noise guidelines in intensive care units and high dependency units, as current limits do not appear to be appropriate for such spaces.
Performing Users
Authors: Higgins Vaughan
Published: April 2007

This article draws on the concept of “performance” to argue for greater recognition of preexisting practices in the configuration of users. Through an Australian case study of a computer-based dairy decision-support system introduced via a two-day workshop to participating farmers, the article examines the assembling of imputed farmer users in the design of the software. It then explores how the designer and trainers attempt, through the decision-support system, to mobilize their network and align the imputed user with farmers' preexisting performances. The case study highlights that attempts to make workable on-farm the “new” performances of users inscribed in the software are highly contingent on farmers' preexisting knowledge practices. These “old” performances problematize the designer's and trainers' version of imputed users and contribute to partial translation of the decision-support system. A focus on performance is argued to provide a useful starting point in mapping the effects of preexisting knowledge practices on attempts to enroll users in technosocial programs.
Translating at Work
Authors: Shostak Sara
Published: April 2007

This paper examines processes of translation through which molecular genetic technologies and practices are incorporated into environmental health research and regulation. Specifically, it considers how scientists, risk assessors, and regulators have used genetically modified mouse models to translate across scientific disciplines, articulate emergent molecular forms, standards, and practices with the extant? gold standard,? and establish roles for molecular knowledge in risk assessment and regulation. Noting variation both within and between regulatory agencies in responses to data from these models, the article describes also the role of public-private networks and their effects on professional and institutional imperatives which shape regulators? responses to the potential applications of these models. The conclusions address the importance of translation for understanding the wider implications of the molecularization of environmental health science.
Negotiating Conception
Authors: Mamo Laura
Published: April 2007

Drawing on in-depth interviews with thirty-six lesbians, this article offers a feminist qualitative analysis of lesbian conception practices. The article examines the ways lesbian actors negotiate biomedical discourse in ways that reveal the co-constitutiveness of nature and culture, bodies and technologies, and biomedical and subjective knowledge. The article offers the concept of hybrid technologies, which are described as lesbian pragmatic negotiations of shifting control loci of technoscience. The author argues that lesbians' pathways to pregnancy are characterized by a negotiation of discursive elements from alternative health discourses and biomedical knowledge, of various forms of technology, and of what is often termed the authoritative, objective, and scientific with the subjugated, subjective, and the embodied. In doing so these actors complicate through multiple agencies what is often interpreted as a totalizing force of biomedicalization.