bluuebunny/crossref_metadata_2025 huggingface dataset:
Two Case Studies on Data Sensitivity of Wireless Sensor Network Algorithms and our Proposal on Scalable, Synthetic Data Generation
Authors: Yu Yan , Estrin Deborah , Govindan Ramesh , Rahimi Mohammad
Published: November 2006

Sensor network research is still in its infancy. There is a large volume of exploratory research. From lack of experimental data and sophisticated models derived from such data, many sensor network publications continue to use data generated from simple models in their algorithm evaluation. It is commonly agreed that data processing algorithms in sensor networks are sensitive to input data. However, no previous efforts have been devoted to quantitatively characterize the range of the algorithm performance when evaluated using different data input.

In this paper, we made the first attempt to quantify the algorithm's sensitivity to data. Our evaluation results demonstrated that different data input could change the algorithm performance by as much as an order of magnitude or even change the relative performance order of two alternative algorithms. This pointed out the need to evaluate sensor network systems with data representing a wide range of real-world scenarios. For each algorithm in our case study, we identified a small set of data characteristics essential to the algorithm's performance. This defined a unique feature of our synthetic data generation framework and made both synthetic data generation and evaluation scalable. To support systematic algorithm evaluation and robust algorithm design and deployment, our synthetic data generation toolbox can generate 1. irregular topology data based on empirical models which will maintain important features of the experimental data; and 2. data corresponding to a wide range of parameter values.
A conjunctive feature similarity effect for visual search
Authors: Takeda Yuji , Phillips Steven , Kumada Takatsune
Published: November 2006

Traditional models of visual search assume interitem similarity effects arise from within each feature dimension independently of other dimensions. In the present study, we examine whether distractor–distractor effects also depend on feature conjunctions (i.e., whether feature conjunctions form a separate “feature” dimension that influences interitem similarity). Spatial frequency and orientation feature dimensions were used to generate distractors. In the bound condition, the number of distractors sharing the same conjunction of features was higher than that in the unbound condition, but the sharing of features within frequency and orientation dimensions was the same across conditions. The results showed that the target was found more efficiently in the bound than in the unbound condition, indicating that distractor–distractor similarity is also influenced by conjunctive representations.
Sterility and Microbiological Assessment of Reused Single-Use Cardiac Electrophysiology Catheters
Authors: Tessarolo Francesco , Caola Iole , Caciagli Patrizio , Guarrera Giovanni M. , Nollo Giandomenico
Published: November 2006

Objective.

To assess the performance and limitations of a reprocessing protocol for nonlumen electrophysiology catheters by testing the sterility of reprocessed devices and defining the maximum number of reprocessing cycles sustainable by the device in hygienically safe conditions.

Design.

Simulated use, reprocessing, and testing of the catheters.

Setting.

Microbiology and virology department of a public health diagnostic laboratory.

Interventions.

Seventy-three catheters were collected after clinical use on patients. The first group of devices was tested for sterility after 1 cycle of reprocessing. By the repetition of simulated use (blood inoculated with bacteria) and reprocessing (decontamination, cleaning, and hydrogen peroxide gas plasma sterilization), we obtained 39 sample devices reprocessed 2 times, 26 reprocessed 3 times, 28 reprocessed 4 times, 36 reprocessed 5 times, and 22 reprocessed 6 times. Devices were cultured for 28 days in trypticase soy broth.

Results.

We tested 208 catheters with 6 cycles of reprocessing and 4 inoculated bacteria species. No devices tested positive for the inoculated strains until the fourth cycle of reprocessing. One of 35 catheters showed the growth of the inoculated strainBacillus subtilisafter 5 cycles of reprocessing, and 1 of 22 catheters showed growth of this organism 6 cycles. After the second reprocessing, 7 of 36 devices showed growth of gram-negative bacteria other than the strain inoculated.

Conclusions.

Reprocessing according to the reprocessing protocol was insufficient to guarantee device sterility after 5 reuses. Cleaning with enzymatic solution revealed good cleaning properties with efficient bioburden reduction. Storage intervals of longer than 24 hours during reprocessing should be avoided to limit contamination or bacterial overgrowth. Technical considerations suggest the introduction of reprocessing procedures only in hospitals with considerable workloads.
Preoperative Use of Mupirocin for the Prevention of Healthcare-AssociatedStaphylococcus aureusInfections: A Cost-Effectiveness Analysis
Authors: Young Lisa S. , Winston Lisa G.
Published: November 2006

Objective.

Staphylococcus aureusis the most common cause of healthcare-associated infections. Intranasal mupirocin treatment probably decreasesS. aureusinfections among colonized surgical patients. Using cost-effectiveness analysis, we evaluated the cost-effectiveness of preoperative use of mupirocin for the prevention of healthcare-associatedS. aureusinfections.

Methods.

Three strategies were compared: (1) screen with nasal culture and give treatment to carriers, (2) give treatment to all patients without screening, and (3) neither screen nor treat. A societal perspective was taken. Adverse outcomes included bloodstream infection, pneumonia, surgical site infection, death due to underlying illness or infection, readmission, and the need for home health care. Data inputs were obtained from an extensive MEDLINE review and from publicly available government data sources. The following base-case data inputs (and ranges) for sensitivity analysis were used: rate ofS. aureuscarriage, 23.1% (19%-55%); efficacy ofmupirocin treatment, 51% (8%-75%); mupirocin treatment cost, $48.36 ($24.18-$57.74); and hospital costs of bloodstream infection, $25,128 ($6,194-$40,211), pneumonia, $18,366 ($5,574-$28,952), and surgical site infection $16,256 ($5,119-$22,553). Widespread use ofmupirocin has been associated with high levels of mupirocin resistance; therefore, a broad range of estimates for efficacy was tested in the sensitivity analysis.

Patients.

The target population included patients undergoing nonemergent surgery requiring postoperative hospitalization.

Results.

Both the screen-and-treat and treat-all strategies were cost saving, saving $102 per patient screened and $88 per patient treated, respectively. In 1-way sensitivity analyses, the model was robust with respect to all data inputs except for the efficacy ofmupirocin treatment. If the efficacy is less than 16.1%, then the screen-and-treat strategy is cost incurring. A treat-all strategy was more cost saving if the rate ofS. aureuscarriage was greater than 42.7%, the mupirocin cost was less than $29.87, or nursing compensation was greater than $64.21 per hour.

Conclusion.

Administration of mupirocin before surgery is cost saving, primarily because healthcare-associated infections are very expensive. The level of mupirocin efficacy is critical to the cost-effectiveness of this intervention.
Surveillance for Surgical Site Infection After Hospital Discharge: A Surgical Procedure–Specific Perspective
Authors: Prospero E. , Cavicchi A. , Bacelli S. , Barbadoro P. , Tantucci L. , D'Errico M. M.
Published: November 2006

Objective.

To estimate the rate of surgical site infection (SSI) occurring after hospital discharge, to evaluate whether limiting surveillance to inpatients underestimates the true rate of SSI, and to select surgical procedures that should be included in a postdischarge surveillance program.

Design.

Prospective surveillance study.

Setting.

A surgical ward at a university teaching hospital in Italy.

Patients.

A total of 264 surgical patients were included in the study.

Results.

The global SSI rate was 10.6% (28 patients); 17 (60.2%) of patients with an SSI developed the infection after hospital discharge. The overall mean length of postoperative stay (±SD) for patients who acquired a postdischarge SSI was 4.9 ± 3.7 days, and SSI was diagnosed a mean duration (±SD) of 11.5 ± 4.5 days after surgery. Among procedures with postdischarge SSIs, those classified by the National Nosocomial Infections Surveillance system (NNIS) as herniorrhaphy, mastectomy, other endocrine system, and other integumentary system were associated with a mean postoperative stay that was less than the mean time between the operation and the onset of SSI. Four (36%) of in-hospital SSIs occurred after procedures with an NNIS risk index of 0, and 7 (64%) occurred after procedures with an NNIS risk index of 1 or higher. Of the 17 SSIs diagnosed after discharge, 14 procedures (82%) had an NNIS risk index of 0, compared with 3 procedures (18%) with an NNIS risk index of 1 or higher.

Conclusions.

Our results revealed an increased risk of postdischarge SSI after some types of surgical procedures and suggest that there is an important need to change from generalized to NNIS operative category-directed postdischarge surveillance, at least for procedures locally considered to be high-risk.
Procedure-Specific Surgical Site Infection Rates and Postdischarge Surveillance in Scotland
Authors: Reilly J. , Allardice G. , Bruce J. , Hill R. , McCoubrey J.
Published: November 2006

Objective.

To investigate the impact of postdischarge surveillance (PDS) on surgical-site infection (SSI) rates for selected surgical procedures in acute care hospitals in Scotland.

Design.

Prospective surveillance of SSI after selected surgical procedures.

Setting.

The Scottish Surveillance of Healthcare Associated Infection Programme (SSHAIP), which is based on the methodology of the Centers for Disease Control and Prevention (CDC) National Nosocomial Infections Surveillance system (NNIS). Thirty-two of 46 acute care hospitals throughout Scotland contributed data to SSHAIP for this study.

Methods.

Data were from 21,710 operations that took place between April 1, 2002, and June 30, 2004; nine categories of surgical procedures were analyzed. CDC NNIS system definitions and methods were used for SSI PDS. PDS is a voluntary component of the mandatory SSI surveillance program in Scotland. PDS was categorized as none, passive, active without direct observation, and active with direct observation.

Results.

From our study information, PDS data were available for 12,885 operations (59%). A total of 2,793 procedures (13%) were associated with passive PDS and 10,092 (46%) with active PDS. The SSI rate among the 8,825 operations with no PDS was 2.61% (95% confidence interval [CI], 2.3%-3.0%), which was significantly lower than the SSI rate found among the 12,885 operations for which PDS was performed (6.34% [95% CI, 5.9%-6.8%]). For breast surgery, cesarean section, hip replacement, and abdominal hysterectomy, the rate of SSI when PDS was performed was significantly higher than that when PDS was not performed (P< .01 for each procedure). No differences in SSI rates were found for surgery to repair fractured neck of the femur or for knee replacement. SSI rates were examined according to procedure type, performance of PDS, and NNIS risk index; rates of SSI increased with NNIS risk index within procedure group and PDS group. Logistic regression analyses confirmed that procedure type, performance of PDS, and NNIS risk index were all statistically independent predictors of report of an SSI (P< .05).

Conclusions.

This Scottish national data set incorporates a substantial amount of PDS data. We recommend a procedure-specific approach to PDS, with direct observation of patients after breast surgery, cesarean section, and hysterectomy, for which the length of stay is typically short. Readmission surveillance may be adequate to detect most SSIs after orthopedic surgery or vascular surgery, for which the length of stay is typically longer.
Effect of Optimized Antibiotic Prophylaxis on the Incidence of Surgical Site Infection
Authors: Manniën Judith , van Kasteren Marjo E. E. , Nagelkerke Nico J. , Gyssens Inge C. , Kullberg Bart Jan , Wille Jan C. , Boer Annette S. de
Published: November 2006

Objective.

To compare the rate of surgical site infection (SSI) before and after an intervention period in which an optimized policy for antibiotic prophylaxis was implemented. To demonstrate that a more prudent, restrictive policy would not have a detrimental effect on patient outcomes.

Design.

Before-after trial with prospective SSI surveillance in the Dutch nosocomial surveillance network (Preventie Ziekenhuisinfecties door Surveillance [PREZIES]), using the criteria of the Centers for Disease Control, including postdischarge surveillance for up to 1 year.

Methods.

During a preintervention period and a postintervention period (both 6-13 months), 12 Dutch hospitals collected data on antimicrobial prophylaxis and SSI rates. The study was limited to commonly performed surgical procedures in 4 specialties: vascular, intestinal, gynecological and orthopedic surgery. Selected risk factors for analysis were sex, age, American Society of Anesthesiologists classification, wound contamination class, duration of surgery, length of hospital stay before surgery, and urgency of surgery (elective or acute).

Results.

A total of 3,621 procedures were included in the study, of which 1,668 were performed before the intervention and 1,953 after. The overall SSI rate decreased from 5.4% to 4.5% (P = .22). Among the procedures included in the study, the largest proportion (55%) were total hip arthroplasty, and the smallest proportion (2%) were replacement of the head of the femur. SSI rates varied from 0% for vaginal hysterectomy to 21.1% for femoropopliteal or femorotibial bypass surgery. Crude and adjusted odds ratios showed that there were no significant changes in procedure-specific SSI rates after the intervention (P>.1).

Conclusions.

An optimized and restrictive antibiotic prophylaxis policy had no detrimental effect on the outcome of clean and clean contaminated surgery, as measured by SSI rate.
Reduction of Surgical Site Infection Rates Associated With Active Surveillance
Authors: Brandt C. , Sohr D. , Behnke M. , Daschner F. , Rüden H. , Gastmeier P.
Published: November 2006

Objective.

To evaluate whether surgical site infection (SSI) rates decrease in surgical departments as a result of performing active SSI surveillance.

Design.

Retrospective multiple logistic regression analyses.

Setting.

A group of 130 surgical departments of German hospitals participating in the Krankenhaus Infektions Surveillance System (KISS).

Methods.

Data for 19 categories of operative procedures performed between January 1997 and June 2004 were included (119,114 operations). Active SSI surveillance was performed according to National Nosocomial Infections Surveillance system (NNIS) methods and definitions. Departments' SSI rates were calculated individually for each year of surveillance and for each operative procedure category, taking into account when the individual departments had begun their surveillance activities. Multiple logistic regression analyses on a single operation basis were carried out with stepwise variable selection to predict outcomes for patients with SSI. The variables included were as follows: the department's year of participation, NNIS risk index variables, patients' age and sex, and the hospitals' structural characteristics, such as yearly operation frequency, number of beds, and academic status.

Results.

For 14 of 19 operative procedure categories analyzed, there was a tendency toward lower SSI rates that was associated with increasing duration of SSI surveillance. In multiple logistic regression analyses of pooled data for all operative procedures, the departments' participation in the surveillance system was a significant independent protective factor. Compared with the surveillance year 1, the SSI risk decreased in year 2 (odds ratio, 0.84; 95% confidence interval, 0.77-0.93) and in year 3 (odds ratio, 0.75; 95% confidence interval, 0.68-0.82), and there was no change in year 4.

Conclusion.

The SSI incidence was reduced by one quarter as a result of the surveillance-induced infection control efforts, which indicates the usefulness of a voluntary surveillance system.
Investigation of a Possible Iatrogenic Case of Creutzfeldt-Jakob Disease After a Neurosurgical Procedure
Authors: Keeler Natalie , Schonberger Lawrence B. , Belay Ermias D. , Sehulster Lynne , Turabelidze George , Sejvar James J.
Published: November 2006

Objective.

To investigate a case of Creutzfeldt-Jakob disease (CJD) possibly acquired from contaminated neurosurgical instruments.

Design.

Retrospective review of medical records, hospital databases, service log books, and state vital statistics.

Setting.

A tertiary care hospital (hospital A) in Missouri.

Patients.

The case patient was a 38-year-old African American woman with a 9-month history of progressive memory loss, visual disturbances, and dementia. She underwent neurosurgery in November 1996. CJD was confirmed in April 2004 by immunodiagnostic testing of brain biopsy samples. All patients who underwent neurosurgery at the same hospital within 6 months before or after the case patient's procedure were identified and investigated for preoperative or postoperative evidence of CJD.

Results.

We reviewed data on 268 neurosurgical procedures, 84 pathology log entries, and 60 death certificates for neurosurgical patients at hospital A and identified 2 suspected cases of CJD. Clinical features and definitive prion testing of stored brain biopsy samples excluded a diagnosis of CJD. Standard operating room procedures were in place, but specific protocols for handling instruments potentially contaminated with prions were not used.

Conclusions.

Neurosurgical instruments were not implicated as the source exposure for CJD in the case patient. The 2 patients with suspected CJD were identified from different data sources, suggesting good internal consistency in data collection. The key elements of this investigation are suggested for use in future investigations into potential cases of iatrogenic CJD.
Reduction in Surgical Antibiotic Prophylaxis Expenditure and the Rate of Surgical Site Infection by Means of a Protocol That Controls the Use of Prophylaxis
Authors: Gómez Marisa I. , Acosta-Gnass Silvia I. , Mosqueda-Barboza Luisa , Basualdo Juan A
Published: November 2006

Objective.

To evaluate the effectiveness of an intervention based on training and the use of a protocol with an automatic stop of antimicrobial prophylaxis to improve hospital compliance with surgical antibiotic prophylaxis guidelines.

Design.

An interventional study with a before-after trial was conducted in 3 stages: a 3-year initial stage (January 1999 to December 2001), during which a descriptive-prospective survey was performed to evaluate surgical antimicrobial prophylaxis and surgical site infections; a 6-month second stage (January to June 2002), during which an educational intervention was performed regarding the routine use of a surgical antimicrobial prophylaxis request form that included an automatic stop of prophylaxis (the “automatic-stop prophylaxis form”); and a 3-year final stage (July 2002 to June 2005), during which a descriptive-prospective survey of surgical antimicrobial prophylaxis and surgical site infections was again performed.

Setting.

An 88-bed teaching hospital in Entre Ríos, Argentina.

Patients.

A total of 3,496 patients who underwent surgery were included in the first stage of the study and 3,982 were included in the final stage.

Results.

Comparison of the first stage of the study with the final stage revealed that antimicrobial prophylaxis was given at the appropriate time to 55% and 88% of patients, respectively (relative risk [RR], 0.27 [95% confidence interval {CI}, 0.25-0.30]; P < .01); the antimicrobial regimen was adequate in 74% and 87% of patients, respectively (RR, 0.50 [95% CI, 0.45-0.55]; P < .01); duration of the prophylaxis was adequate in 44% and 55% of patients, respectively (RR, 0.80 [95% CI, 0.77-0.84]; P < .01); and the surgical site infection rates were 3.2% and 1.9%, respectively (RR, 0.59 [95% CI, 0.44-0.79]; P < .01). Antimicrobial expenditure was US$10,678.66 per 1,000 patient-days during the first stage and US$7,686.05 per 1,000 patient-days during the final stage (RR, 0.87 [95% CI, 0.86-0.89]; P<.01).

Conclusion.

The intervention based on training and application of a protocol with an automatic stop of prophylaxis favored compliance with the hospital's current surgical antibiotic prophylaxis guidelines before the intervention, achieving significant reductions of surgical site infection rates and substantial savings for the healthcare system.
Comparison of Routine Prophylaxis With Vancomycin or Cefazolin for Femoral Neck Fracture Surgery: Microbiological and Clinical Outcomes
Authors: Merrer Jacques , Desbouchages Laetitia , Serazin Valérie , Razafimamonjy Jimmy , Pauthier François , Leneveu Michel
Published: November 2006

Objective.

To assess the impact of antibiotic prophylaxis on the emergence of vancomycin-resistant strains of Enterococcus faecium, Enterococcus faecalis, and Staphylococcus aureus and the incidence of surgical site infection (SSI) after vancomycin or cefazolin prophylaxis for femoral neck fracture surgery.

Design.

Prospective cohort study.

Setting.

A hospital with a high prevalence of methicillin-resistant S. aureus (MRSA) carriage.

Patients.

All patients admitted with a femoral neck fracture from March 1, 2004 through February 28, 2005 were prospectively identified and screened for MRSA and vancomycin-resistant (VRE) carriage at admission and at day 7. Deep incisional and organ/space SSIs were also recorded.

Results.

Of 263 patients included in the study, 152 (58%) received cefazolin and 106 (40%) received vancomycin. At admission, the prevalence of MRSA carriage was 6.8%; it was 12% among patients with risk factors and 2.2% among patients with no risk factors (P = .002). At day 7 after surgery, there were 6 patients (2%) who had hospital-acquired MRSA, corresponding to 0.7% in the cefazolin group and 5% in the vancomycin group (P = .04); none of the MRSA isolates were resistant to glycopeptides. The rate of VRE carriage at admission was 0.4%. Three patients (1%) had acquired carriage of VRE (1 had E. faecium and 2 had E. faecalis); all 3 were in the cefazolin group (2% of patients) and none in the vancomycin group (P = .27). Eight SSIs (3%) occurred, 4% in the cefazolin group and 2% in the vancomycin group (P = .47).

Conclusions.

This preliminary study demonstrates that cefazolin and vancomycin prophylaxis have similar impacts on the emergence of glycopeptide-resistant pathogens. Neither MRSA infection nor increased rates of SSI with other bacteria were observed in the vancomycin group, suggesting that a larger multicenter study should be initiated.
Effect of Antimicrobial Prophylaxis on the Incidence of Infections in Clean Surgical Wounds in Hospitals Undergoing Renovation
Authors: Iribarren Osvaldo , Araujo Miguel
Published: November 2006

Objective.

To measure the effect of cephazolin prophylaxis on the rate of surgical site infection among patients with clean surgical wounds, categorized by risk group, in a hospital undergoing renovation.

Design.

Randomized, double-blind clinical trial.

Setting.

Saint Paul General Hospital, Coquimbo, Chile, during a period when it was undergoing significant interior remodeling.

Patients.

General surgery patients who received antibiotic prophylaxis before clean wound surgery between March 2003 and May 2004 and a matched control group of patients who did not receive such prophylaxis.

Results.

A total of 303 patients participated in the study. The rate of infection among patients with an American Society of Anesthesiologists (ASA) classification of 1 in the prophylaxis group was 7.3%, whereas among ASA 1 patients in a no-prophylaxis control group it was 10.3% (P= .40). In the prophylaxis group, the ASA 2 and ASA 3 patients combined had an infection rate of 10.5%, whereas in the no-prophylaxis group these patients had a rate of 30.0% (relative risk, 0.33 [95% confidence interval, 0.58-0.96];P= .03). Both the ASA 2 and ASA 3 patients were protected from infection by prophylaxis; these patients had 1.7 and 2.2 times, respectively, more risk of developing a surgical site infection than did ASA 1 patients after a clean surgical procedure, but the ASA 2 and ASA 3 patients who did not receive prophylaxis had 4.3 and 4.8 times, respectively, greater risk of infection (relative risk, 0.91 [95% confidence interval, 0.83-0.99];P= .02). Prophylaxis significantly reduced the rate of infection in the ASA 2 and ASA 3 groups.

Conclusions.

We recommend the use of antimicrobial prophylaxis with cephalosporins in ASA 2 and ASA 3 patients undergoing clean wound surgery during a period when significant renovations are being performed in the hospital.
Case-Control Study of Risk Factors for Mediastinitis After Cardiovascular Surgery
Authors: Gude M. J. López , Juan R. San , Aguado J. M. , Maroto L. , López-Medrano F. , Romero J. M. Cortina , Rufilanchas J. J.
Published: November 2006

We report results of a case-control study in which we evaluated 41 risk factors potentially associated with the development of post-surgical mediastinitis. There were 163 case patients and 326 control patients. Independent risk factors kept in the final multivariate logistic regression model were obesity (defined as a body mass index of greater than 30), diabetes mellitus, chronic obstructive pulmonary disease, preoperative stay longer than 1 week, pulmonary hypertension, perioperative myocardial infarction, and reoperation.
Efficient Cargo Sorting by ESCRT-I and the Subsequent Release of ESCRT-I from Multivesicular Bodies Requires the Subunit Mvb12
Authors: Curtiss Matt , Jones Charles , Babst Markus
Published: November 2006

The endosomal sorting complex required for transport (ESCRT)-I protein complex functions in recognition and sorting of ubiquitinated transmembrane proteins into multivesicular body (MVB) vesicles. It has been shown that ESCRT-I contains the vacuolar protein sorting (Vps) proteins Vps23, Vps28, and Vps37. We identified an additional subunit of yeast ESCRT-I called Mvb12, which seems to associate with ESCRT-I by binding to Vps37. Transient recruitment of ESCRT-I to MVBs results in the rapid degradation of Mvb12. In contrast to mutations in other ESCRT-I subunits, which result in strong defects in MVB cargo sorting, deletion of MVB12 resulted in only a partial sorting phenotype. This trafficking defect was fully suppressed by overexpression of the ESCRT-II complex. Mutations in MVB12 did not affect recruitment of ESCRT-I to MVBs, but they did result in delivery of ESCRT-I to the vacuolar lumen via the MVB pathway. Together, these observations suggest that Mvb12 may function in regulating the interactions of ESCRT-I with cargo and other proteins of the ESCRT machinery to efficiently coordinate cargo sorting and release of ESCRT-I from the MVB.
The Assembly Pathway of the 19S Regulatory Particle of the Yeast 26S Proteasome
Authors: Isono Erika , Nishihara Kiyoshi , Saeki Yasushi , Yashiroda Hideki , Kamata Naoko , Ge Liying , Ueda Takashi , Kikuchi Yoshiko , Tanaka Keiji , Nakano Akihiko , Toh-e Akio
Published: November 2006

The 26S proteasome consists of the 20S proteasome (core particle) and the 19S regulatory particle made of the base and lid substructures, and it is mainly localized in the nucleus in yeast. To examine how and where this huge enzyme complex is assembled, we performed biochemical and microscopic characterization of proteasomes produced in two lid mutants, rpn5-1 and rpn7-3, and a base mutant ΔN rpn2, of the yeast Saccharomyces cerevisiae. We found that, although lid formation was abolished in rpn5-1 mutant cells at the restrictive temperature, an apparently intact base was produced and localized in the nucleus. In contrast, in ΔN rpn2 cells, a free lid was formed and localized in the nucleus even at the restrictive temperature. These results indicate that the modules of the 26S proteasome, namely, the core particle, base, and lid, can be formed and imported into the nucleus independently of each other. Based on these observations, we propose a model for the assembly process of the yeast 26S proteasome.
The Metalloprotease Encoded byATP23Has a Dual Function in Processing and Assembly of Subunit 6 of Mitochondrial ATPase
Authors: Zeng Xiaomei , Neupert Walter , Tzagoloff Alexander
Published: November 2006

In the present study we have identified a new metalloprotease encoded by the nuclear ATP23 gene of Saccharomyces cerevisiae that is essential for expression of mitochondrial ATPase (F1-FOcomplex). Mutations in ATP23 cause the accumulation of the precursor form of subunit 6 and prevent assembly of FO. Atp23p is associated with the mitochondrial inner membrane and is conserved from yeast to humans. A mutant harboring proteolytically inactive Atp23p accumulates the subunit 6 precursor but is nonetheless able to assemble a functional ATPase complex. These results indicate that removal of the subunit 6 presequence is not an essential event for ATPase biogenesis and that Atp23p, in addition to its processing activity, must provide another important function in FOassembly. The product of the yeast ATP10 gene was previously shown to interact with subunit 6 and to be required for its association with the subunit 9 ring. In this study one extra copy of ATP23 was found to be an effective suppressor of an atp10 null mutant, suggesting an overlap in the functions of Atp23p and Atp10p. Atp23p may, therefore, also be a chaperone, which in conjunction with Atp10p mediates the association of subunit 6 with the subunit 9 ring.
Localization of a long-range cis-regulatory element of IL13 by allelic transcript ratio mapping
Authors: Forton Julian T. , Udalova Irina A. , Campino Susana , Rockett Kirk A. , Hull Jeremy , Kwiatkowski Dominic P.
Published: November 2006

It appears that, for many genes, the two alleles possessed by an individual may produce different amounts of transcript. When such allelic differences in transcription are observed for some individuals but not others, a plausible explanation is genetic variation in the cis-acting elements that regulate the gene in question. Here we describe a novel analytical approach that uses such observations, combined with genotyping data from the HapMap project, to define the genomic location of cis-acting regulatory elements. When applied to the human 5q31 chromosomal region, where complex regulatory mechanisms are known to exist, we demonstrate the sensitivity of this approach by locating a highly significant cis-regulatory element operating on IL13 at long range from a position 250 kb upstream from the gene (P = 2 × 10−6). As this method is unaffected by other sources of variation, such as environmental and trans-acting genetic factors, it provides a tractable approach for dissecting the complexities of genetic variation in gene regulation.
6-Azauracil Sensitivity Assay for Yeast
Authors: Tansey William P.
Published: December 2006

INTRODUCTION

Treatment of yeast with 6-Azauracil (6AU) leads to a reduction of intracellular GTP levels. The reduction in GTP levels is not itself lethal, but can block yeast growth when combined with mutations that affect transcriptional elongation. 6AU sensitivity thus can be used as a crude assay to test for mutations that affect transcriptional elongation. The assay described here requires growing saturated cultures of yeast, counting, and spotting serial dilutions of yeast on both CSM and CSM + 6AU plates.
Plating Cells for Microinjection
Authors: Dean David A.
Published: December 2006

INTRODUCTION

This protocol describes a method for plating cells for microinjection onto etched coverslips. The coverslips for microinjection must be marked so that microinjected cells can be identified at time points after injection. A procedure for etching coverslips is given below; alternatively, pre-etched coverslips can be purchased at slightly higher cost.
Preparation (Pulling) of Needles for Gene Delivery by Microinjection
Authors: Dean David A.
Published: December 2006

INTRODUCTION

This protocol contains methods for pulling microinjection needles using two different models of pipette pullers. The advantage of pulling needles in the laboratory is that a variety of different needle types can be pulled, depending on the samples and cells being injected. An added advantage is cost; once a pipette puller has been purchased, boxes of glass capillaries are inexpensive compared to premade microinjection needles. The advantages to buying preformed and sterilized needles include increased uniformity of needles from one to another, ease of use, high quality, and not having to invest in a pipette puller. The pipette puller models described in this article are the Flaming/Brown Pipette Puller Model P-97 (Sutter) and the PUL-1 Micropipette Puller (World Precision Instruments). The PUL-1 instrument is the less expensive of the two, but it requires more user input, and it cannot be used to pull Femtotip-like microinjection pipettes.
Transformation of Agrobacterium Using Electroporation
Authors: Weigel Detlef , Glazebrook Jane
Published: December 2006

INTRODUCTION

This protocol describes a method for transforming Agrobacterium with plasmid DNA using electroporation in a manner similar to that commonly used for Escherichia coli. Although the transformation efficiency for Agrobacterium is lower than that for E. coli, it is possible to obtain adequate numbers of Agrobacterium transformants with this technique.
C-23 Hydroxylation byArabidopsisCYP90C1 and CYP90D1 Reveals a Novel Shortcut in Brassinosteroid Biosynthesis
Authors: Ohnishi Toshiyuki , Szatmari Anna-Maria , Watanabe Bunta , Fujita Satomi , Bancos Simona , Koncz Csaba , Lafos Marcel , Shibata Kyomi , Yokota Takao , Sakata Kanzo , Szekeres Miklos , Mizutani Masaharu
Published: December 2006

Brassinosteroids (BRs) are biosynthesized from campesterol via several cytochrome P450 (P450)–catalyzed oxidative reactions. We report the functional characterization of two BR-biosynthetic P450s from Arabidopsis thaliana: CYP90C1/ROTUNDIFOLIA3 and CYP90D1. The cyp90c1 cyp90d1 double mutant exhibits the characteristic BR-deficient dwarf phenotype, although the individual mutants do not display this phenotype. These data suggest redundant roles for these P450s. In vitro biochemical assays using insect cell-expressed proteins revealed that both CYP90C1 and CYP90D1 catalyze C-23 hydroxylation of various 22-hydroxylated BRs with markedly different catalytic efficiencies. Both enzymes preferentially convert 3-epi-6-deoxocathasterone, (22S,24R)-22-hydroxy-5α-ergostan-3-one, and (22S,24R)-22-hydroxyergost-4-en-3-one to 23-hydroxylated products, whereas they are less active on 6-deoxocathasterone. Likewise, cyp90c1 cyp90d1 plants were deficient in 23-hydroxylated BRs, and in feeding experiments using exogenously supplied intermediates, only 23-hydroxylated BRs rescued the growth deficiency of the cyp90c1 cyp90d1 mutant. Thus, CYP90C1 and CYP90D1 are redundant BR C-23 hydroxylases. Moreover, their preferential substrates are present in the endogenous Arabidopsis BR pool. Based on these results, we propose C-23 hydroxylation shortcuts that bypass campestanol, 6-deoxocathasterone, and 6-deoxoteasterone and lead directly from (22S,24R)-22-hydroxy-5α-ergostan-3-one and 3-epi-6-deoxocathasterone to 3-dehydro-6-deoxoteasterone and 6-deoxotyphasterol.
Food‐dependent individual growth and population dynamics in fishes*
Authors: Persson L. , De Roos A. M.
Published: December 2006

It is long since well established that growth and development in fish individuals are heavily dependent on food intake. Yet, this dependence of individual development on food levels has only to a limited extent been taken into consideration when studying fish population and community processes. Using the modelling framework of physiologically structured population models and empirical data for a number of species configurations, how different size‐dependent processes may affect fish population dynamics and community structures are reviewed. Considering competitive interactions, cohort interactions will often give rise to cohort cycles driven by an inequality in competitive abilities between differently sized individuals. The addition of cannibalism may dampen these cycles, the extent to which is dependent on life‐history characteristics of the cannibals. The circumstance that individuals change their trophic position over their life cycle as a result of an increase in size gives rise to life history omnivory. In such omnivorous systems, food‐dependent growth demotes the potential for predatory and prey fishes to coexist. In tritrophic food chains, food‐dependent growth in the intermediate consumer may lead to the presence of bistability including sensitivity to catastrophic behaviour. These results shed new light on the drastic decreases observed in the stocks of many marine fish top predators including their inability to recover after fishing moratoria, and on the suggested presence of alternative states in freshwater fish communities.
Exploring the structure of genetic variation and the influences of demography on effective population size in the gag grouper Mycteroperca microlepi (Goode & Bean)
Authors: Jue N. K.
Published: December 2006

Using 11 microsatellite markers, genetic analyses of three successive year‐classes of gag Mycteroperca microlepis juveniles across the north‐eastern Gulf of Mexico revealed a lack of spatial structure and very little temporal variation between year‐classes. These results are consistent with long‐term effective population sizes on the order of 30 000 adults. The importance of reproductive‐style and sex‐ratio variation is discussed as an important influence on long‐term effective sizes.
Transfusion prevents acute chest syndrome predicted by elevated secretory phospholipase A2
Authors: Styles Lori A , Abboud Miguel , Larkin Sandra , Lo Margaret , Kuypers Frans A.
Published: November 2006

Acute pulmonary injury is known as acute chest syndrome (ACS) in patients with sickle cell disease (SCD). Secretory phospholipase A2 (sPLA2) was found to predict those at risk for ACS and a trial was designed to determine if red blood cell transfusion can be used to prevent ACS. Patients with an elevated sPLA2 were randomised to either receive a single transfusion or standard care. Five of the eight patients (63%) randomised to standard care developed ACS versus none of the seven patients randomised to the transfusion arm (P = 0·026, Odds ratio = 23·6, 95% confidence interval 1, 557). This study suggests that transfusion may prevent ACS.
Immunogenetic factors determining the evolution of T‐cell large granular lymphocyte leukaemia and associated cytopenias
Authors: Nearman Zachary P. , Wlodarski Marcin , Jankowska Anna M. , Howe Evan , Narvaez Yadira , Ball Edward , Maciejewski Jaroslaw P.
Published: November 2006

T‐cell large granular lymphocyte leukaemia (T‐LGL) is a chronic clonal proliferation of cytotoxic T lymphocytes (CTL). T‐LGL presents with cytopenias, often accompanied by autoimmune diseases, suggesting clonal transformation arising from an initially polyclonal immune response. Various immunogenetic predisposition factors, previously described for both immune‐mediated bone marrow failure and autoimmune conditions, may promote T‐LGL evolution and/or development of cytopenias. The association of T‐LGL was analysed with a number of immunogenetic factors in 66 patients, including human leucocyte antigen (HLA) and killer‐cell immunoglobulin‐like receptor (KIR) genotype, KIR/KIR‐L mismatch, CTLA‐4 (+49 A/G),CD16−158V/F, CD45 polymorphisms, cytokine single nucleotide polymorphisms including: TNF‐α (−308G/A), TGF‐β1 (codons 10 C/T, 25 G/C), IL‐10 (−1082 G/A), IL‐6 (−174 C/G), and IFN‐γ(+874 T/A). A statistically significant increase in A/A genotype for TNF‐α−308, IL‐10–1082, andCTLA‐4 +49 was observed in T‐LGL patients compared with control, suggesting that the G allele serves a protective role in each case. No association was found between specific KIR/HLA profile and disease. KIR/KIR‐L analysis revealed significant mismatches between KIR3DL2 and KIR2DS1 and their ligands HLA‐A3/11 and HLA‐C group 2 (P = 0·03 and 0·01 respectively); the biological relevance of this finding is questionable. The significance of additional genetic polymorphisms and their clinical correlation to evolution of T‐LGL requires future analysis.
Do Workplace Contracts Harm Labour Productivity Growth? A Reconsideration of the Macroeconomic Evidence from New Zealand
Authors: Perry L. J.
Published: November 2006

This article reconsiders the argument advanced or endorsed by a large number of leading Australian academics and others that labour productivity growth in New Zealand fell markedly during the period in which New Zealand's Employment Contracts Act 1991 (ECA) was operative—that is, for most of the 1990s. On the one hand, based on total economy estimates developed by The Conference Board and the Groningen Growth and Development Centre, labour productivity growth was unexceptional though a little higher than the New Zealand average of the last three decades or so. On the other hand, based on newly released official estimates of New Zealand's ‘measured sector’ (which accounts for about two‐thirds of the total economy), labour productivity growth was almost identical to that of Australia during the EC A period. This in turn suggests that New Zealand's labour productivity growth rose markedly for the measured sector during the EC A years. All in all, the evidence presented in this article is inconsistent with claims that the period of the EC A was associated with relatively weak New Zealand productivity growth. Selected issues arising from these findings are briefly canvassed.
Government Bond Seigniorage
Authors: Hu Yifan
Published: November 2006

Recent studies have indicated that government bonds are an imperfect substitute for money in providing transaction services. Based on these studies, this article develops a theoretical framework showing that, as with money seigniorage, the government can gain an interest benefit from issuing government bonds. The article terms this interest benefit as ‘government bond seigniorage’. Further, the article estimates government bond seigniorage in comparison with money seigniorage for five countries (Australia, Canada, France, Italy and the United States) during the period 1959–2001. It is found that government bond seigniorage accounts for a larger percentage of Gross Domestic Product than money seigniorage, but also experiences greater fluctuations for all sample countries.
Crime and Labour Market Opportunities in Italy (1993–2002)
Authors: Buonanno Paolo
Published: November 2006

Abstract.  This paper investigates the relationship between labour market conditions and crime in Italy accounting for both age and gender in the unemployment measure and considering regional disparities between the North‐Centre and the South of Italy. Using regional data over the period 1993–2002, we study the impact of wages and unemployment on different types of crime. To mitigate omitted variables bias, we control extensively for demographic and socio‐economic variables. Empirical results suggest that unemployment has a large and positive effect on crime rates in southern regions. Our results are robust to model specification, endogeneity, changes in the classification of crimes, and finally, to alternative definitions of unemployment.
Wage Commitment, Signalling, and Entry Deterrence or Accommodation
Authors: Pal Rupayan , Saha Bibhas
Published: November 2006

Abstract.  We analyse the wage choice of a monopoly union against entry threat. The wage carries information about market demand, which is crucial to an uninformed entrant, and in addition affects the entrant's post‐entry cost through labour market institutions. The union may wish to deter or accommodate entry depending on whether the entrant will hire from a different source or from the union. Equilibrium wage is distorted downwardly (upwardly) for deterrence (accommodation); but because of wage correlation a low (high) wage can also turn entry profitable (unprofitable). Therefore, separating equilibrium may not always exist, and entry outcomes may be inefficient.
The Gender Wage Gap and Poverty in Colombia
Authors: Angel‐Urdinola Diego F. , Wodon Quentin
Published: November 2006

Abstract.  Using 19 years of cross‐section wage data, we look at the trend of the ratio of male to female wages in Colombia. First, we observe a long‐term trend towards an increase in the gender wage gap that may be related to new labor regulations giving more protection to women and thereby raising the cost of female employment for firms. Second, we measure the impact on poverty of the increasing gap by producing estimates of the income distribution for the subsequent years had the wage gap remained at the low level it used to be in the early 1990s. As mainly low‐skilled women suffered from the increase in the wage gap, we find that the phenomenon contributed to an overall increase in poverty during the decade.
INFLATION IN CHINA: MODELLING A ROLLER COASTER RIDE
Authors: Funke Michael
Published: November 2006

Abstract.  The New Keynesian Phillips curve (NKPC) posits the dynamics of inflation as forward looking and related to marginal costs. In this paper we examine the empirical relevance of the NKPC for China. The empirical results indicate that an augmented (hybrid) NKPC gives results that are consistent with the data generating process. It is in this respect that the NKPC provides useful insights into the nature of inflation dynamics in China as well as useful insights for the conduct of monetary policy.
DETERMINANTS OF SCHOOL ATTENDANCE AMONG MIGRANT CHILDREN: SURVEY EVIDENCE FROM CHINA'S JIANGSU PROVINCE*
Authors: Nielsen Ingrid , Nyland Berenice , Nyland Chris , Smyth Russell , Zhang Mingqiong
Published: November 2006

Abstract. Across the developing world education is seen as a means of raising levels of everyday wellbeing and is being linked to improved measures of productivity and economic growth. This paper employs a household production function framework to examine the determinants of school attendance among migrant children using a unique dataset collected in China's Jiangsu province. The study finds that the main predictors of school attendance among migrant children in the sample were household income, mother's education, the length of residence of the child's mother in the city and whether both parents were working in the same city.
IS TECHNICAL ANALYSIS USEFUL FOR STOCK TRADERS IN CHINA? EVIDENCE FROM THE SZSE COMPONENT A‐SHARE INDEX
Authors: Chen Kong‐Jun , Li Xiao‐Ming
Published: November 2006

Abstract.  This paper uses daily stock prices and the trading volume of 39 constituent companies in the SZSE Component A‐Share Index on the Shenzhen Stock Exchange to examine the usefulness of technical analysis. It finds very weak evidence to support the view that traders and/or technical analysts can learn more about the future pattern of returns by actively using volume in conjunction with returns than those who only watch price movements.
FINANCIAL INTEGRATION IN EAST ASIAN EQUITY MARKETS
Authors: Chi Jing , Li Ke , Young Martin
Published: November 2006

Abstract.  This paper examines the degree of financial integration that exists in East Asian equity markets using the International Capital Asset Pricing Model methodology. We employ three market portfolios to test for integration: the weighted average equity index of all sample countries, the Japanese market index and the US market index. The study shows that the level of financial efficiency and the integration of sample countries is high and has improved significantly during 1991 to 2005, and they are more financially integrated within the region and with the Asian leading market (Japan) than with the world leading market (the USA).