bluuebunny/crossref_metadata_2025 huggingface dataset:
The optimal number of lymph nodes examined in stage II colorectal cancer and its impact of on outcomes
Authors: Choi Hok Kwok , Law Wai Lun , Poon Jensen TC
Published: June 2010

Background

Lymph node status is the most important prognostic factor for colorectal cancer. The number of lymph nodes that should be histologically examined has been controversial. The aims of this study were to assess the impact of the number of lymph nodes examined on survival of patients with stage II colorectal cancer and to determine the optimal number of lymph nodes that should be examined.

Methods

The study included 664 patients who underwent resection for stage II colorectal cancer. The clinical and histopathologic data of the patients were prospectively collected and analyzed.

Results

The median number of lymph nodes examined was 12 (range: 1 to 58). The 5-year disease free survival rate was significantly higher for patients with 12 or more lymph nodes examined compared to those with less than 12 lymph nodes examined. The significant difference in 5-year disease free survival persisted if the dividing number increased progressively from 12 to 23. However, the difference in survival was most significant (lowest p value and highest hazard ratio) for the number 21. The 5-year disease free survival of patients with 21 or more lymph nodes examined was 80% whereas that of patients with less than 21 lymph nodes examined was 60% (p = 0.001, hazard ratio 2.08). Multivariate analysis showed that 21 or more lymph nodes examined was a factor that independently influenced survival. The 5-year disease free survival also increased progressively with the number of lymph node examined up to the number 21. After the number 21, the survival rate did not increase further. It was likely that 21 was the optimal number, at and above which the chance of lymph node metastasis was minimal.

Conclusions

The number of lymph nodes examined in colorectal cancer specimen significantly influences survival. It is recommended that at least 21 lymph nodes should be examined for accurate diagnosis of stage II colorectal cancer.
Active site plasticity revealed from the structure of the enterobacterial N-ribohydrolase RihA bound to a competitive inhibitor
Authors: Garau Gianpiero , Muzzolini Laura , Tornaghi Paola , Degano Massimo
Published: June 2010

Background

Pyrimidine-preferring N-ribohydrolases (CU-NHs) are a class of Ca2+-dependent enzymes that catalyze the hydrolytic cleavage of the N-glycosidic bond in pyrimidine nucleosides. With the exception of few selected organisms, their physiological relevance in prokaryotes and eukaryotes is yet under investigation.

Results

Here, we report the first crystal structure of a CU-NH bound to a competitive inhibitor, the complex between the Escherichia coli enzyme RihA bound to 3, 4-diaminophenyl-iminoribitol (DAPIR) to a resolution of 2.1 Å. The ligand can bind at the active site in two distinct orientations, and the stabilization of two flexible active site regions is pivotal to establish the interactions required for substrate discrimination and catalysis.

Conclusions

A comparison with the product-bound RihA structure allows a rationalization of the structural rearrangements required for an enzymatic catalytic cycle, highlighting a substrate-assisted cooperative motion, and suggesting a yet overlooked role of the conserved His82 residue in modulating product release. Differences in the structural features of the active sites in the two homologous CU-NHs RihA and RihB from E. coli provide a rationale for their fine differences in substrate specificity. These new findings hint at a possible role of CU-NHs in the breakdown of modified nucleosides derived from RNA molecules.
Analysis of factors influencing the outpatient workload at Chinese health centres
Authors: Xu Jing , Wang Wenxin , Li Yongbin , Zhang Juan , Pavlova Milena , Liu Hua , Yin Ping , Lu Zuxun
Published: June 2010

Background

Although the community health service system is now established in China, the utilisation of the community health service institutions is low due to the lack of a gate-keeping role of the primary health service providers and referrals among the three-tiered health service institutions. In addition to this, patients who can afford to pay, often seek best services in big hospitals to guarantee the quality of care. Thus, the need of guiding the patients to the community health services and increasing the utilisation of the community health service institutions is becoming an urgent problem, which hinders the future development of community health services. This study focuses on the question of how to increase the utilisation of Chinese community health centres (HCs).

Methods

A cross-sectional Base-line Survey of Chinese City Community Health Service System Building using the multi-staged cluster sampling was conducted to collect data from all HCs in 28 key contact cities. Relevant indicators of totally 1790 HCs were analysed. The statistical methods included ANONVA and logistic regression.

Results and Conclusions

The analysis suggested several key factors for increasing the outpatient workload (OW) at the HCs: establishing an adequate referral system among the different levels of the health system; enhancing the qualification of health personnel and increasing the compensation by the health insurance for services provided at HCs. Other key factors with a positive effect on the OW included: the government ownership of the HCs, the scale of the institutions, the medical equipment used, the mix of health services provided, and the women in childbearing age in the residence.
Household headship and child death: Evidence from Nepal
Authors: Adhikari Ramesh , Podhisita Chai
Published: June 2010

Background

Nepal has seen substantial improvements in its reproductive health outcomes, but infant and child mortality are still high. This study attempts to examine the prevalence and factors influencing the experience of child death of mothers who have given birth during a five-year period. More specifically, this paper aims to investigate whether household headship has an impact on child death in Nepal.

Methods

This paper reports on data drawn from the Nepal Demographic and Health Survey (NDHS 2006), a nationally representative sample survey. The analysis is confined to women who had given birth during the five years preceding the survey (n = 4066). The association between experience of child death of mother and the explanatory variables was assessed via bivariate analysis using a chi-square test. The variables were also examined using multivariate analysis (binary logistic regression) to assess the net effect of household headship on child death after controlling for the other variables.

Results

Out of all the mothers who had given birth during a five-years period, 3,229 (79.4%) were from male-headed households; the remaining 837 (20.6%) were from female-headed households. A significantly higher proportion of mothers from male-headed households (6.5%) than female-headed households (4.5%) had experienced the death of a child over the five years preceding the survey. Several socio-demographic, economic, and cultural variables were significant predicators for death of a child. For instance, women who had given birth to three or more children and who were Hindu were more likely to experience a child's death than were their counterparts. On the other hand, women who were literate, who had ever used family planning methods, who had visited a health facility, who utilized antenatal care for the last pregnancy, and who were from female-headed households were less likely to see a child die than were women in their comparison group. Notably, keeping all other control variables constant in the logistic model, women from female-headed households were 31 percent less likely to experience the death of a child (odds ratio = 0.69) than were women from male-headed households.

Conclusion

The death of children is not uncommon in Nepal. No single factor can account for the high child mortality in the country; many factors contribute to the problem. After controlling for other variables, this study found that, among many other factors, household headship was a strong predictor. Programs seeking to help remedy this problem should focus on the issues identified here regarding women's autonomy, such as reducing the number of children born, increasing women's literacy status, increasing the use of family planning, increasing the use of antenatal care, and increasing female household headship so that child mortality will decrease and the overall well-being of the family can be maintained and enhance.
Proteomic analysis of the fish pathogen Flavobacterium columnare
Authors: Dumpala Pradeep R , Gülsoy Nagihan , Lawrence Mark L , Karsi Attila
Published: June 2010

Background

Flavobacterium columnare causes columnaris disease in cultured and wild fish populations worldwide. Columnaris is the second most prevalent bacterial disease of commercial channel catfish industry in the United States. Despite its economic importance, little is known about the expressed proteins and virulence mechanisms of F. columnare. Here, we report the first high throughput proteomic analysis of F. columnare using 2-D LC ESI MS/MS and 2-DE MALDI TOF/TOF MS.

Results

Proteins identified in this study and predicted from the draft F. columnare genome were clustered into functional groups using clusters of orthologous groups (COGs), and their subcellular locations were predicted. Possible functional relations among the identified proteins were determined using pathway analysis. The total number of unique F. columnare proteins identified using both 2-D LC and 2-DE approaches was 621, of which 10.95% (68) were identified by both methods, while 77.29% (480) and 11.76% (73) were unique in 2-D LC and 2-DE, respectively. COG groupings and subcellular localizations were similar between our data set and proteins predicted from the whole genome. Twenty eight pathways were significantly represented in our dataset (P < 0.05).

Conclusion

Results from this study provide experimental evidence for many proteins that were predicted from the F. columnare genome annotation, and they should accelerate functional and comparative studies aimed at understanding virulence mechanisms of this important pathogen.
Disability status and quality of life in multiple sclerosis: non-linearity of the Expanded Disability Status Scale (EDSS)
Authors: Twork Sabine , Wiesmeth Susanne , Spindler Milena , Wirtz Markus , Schipper Sabine , Pöhlau Dieter , Klewer Jörg , Kugler Joachim
Published: June 2010

Background

Progression in disability as measured by increase in the Expanded Disability Status Scale (EDSS) is commonly used as outcome variable in clinical trials concerning multiple sclerosis (MS). In this study, we addressed the question, whether there is a linear relationship between disability status and health related quality of life (HRQOL) in MS.

Methods

7305 MS patients were sent a questionnaire containing a German version of the "Multiple Sclerosis Quality of Life (MSQOL)-54" and an assessment of self-reported disability status analogous to the EDSS. 3157 patients participated in the study. Patients were allocated to three groups according to disability status.

Results

Regarding the physical health composite and the mental health composite as well as most MSQOL-54 subscales, the differences between EDSS 4.5-6.5 and EDSS >= 7 were clearly smaller than the differences between EDSS <= 4 and EDSS 4.5-6.5.

Conclusion

These results indicate a non-linear relationship between disability status and HRQOL in MS. The EDSS does not seem to be interval scaled as is commonly assumed. Consequently, absolute increase in EDSS does not seem to be a suitable outcome variable in MS studies.
Cloning, expression and characterization of gE protein of Duck plague virus
Authors: Chang Hua , Cheng Anchun , Wang Mingshu , Zhu Dekang , Jia Renyong , Liu Fei , Chen Zhengli , Luo Qihui , Chen Xiaoyue , Zhou Yi
Published: June 2010

Background

The gE protein of duck plague virus is the important membrane glycoprotein, its protein characterization has not been reported. In this study, we expressed and presented the characterization of the DPV gE product.

Results

According to the sequence of the gE gene, a pair of primers were designed, and the DNA product with 1490bp in size was amplified by using the polymerase chain reaction (PCR). The PCR product was cloned into pMD18-T vector, and subcloned into pET32a(+), generating the recombinant plasmid pET32a/DPV-gE. SDS-PAGE analysis showed that the fusion pET32a/DPV-gE protein was highly expressed after induction by 0.2 mM IPTG at 30°C for 4.5 h in Rosseta host cells. Over expressed 6×His-gE fusion protein was purified by nickel affinity chromatography, and used to immunize the rabbits for the preparation of polyclonal antibody. The result of the intracellular localization revealed that the gE protein was appeared to be in the cytoplasm region. The real time PCR, RT-PCR analysis and Western blotting revealed that the gE gene was produced most abundantly during the late phase of replication in DPV-infected cells.

Conclusions

In this work, the DPV gE protein was successfully expressed in a prokaryotic expression system, and we presented the basic properties of the DPV gE product for the first time. These properties of the gE protein provided a prerequisite for further functional analysis of this gene.
Effects of Ranolazine on Wild-Type and Mutant hNav1.7 Channels and on DRG Neuron Excitability
Authors: Estacion Mark , Waxman Stephen G , Dib-Hajj Sulayman D
Published: June 2010

Background:

A direct role of sodium channels in pain has recently been confirmed by establishing a monogenic link between SCN9A, the gene which encodes sodium channel Nav1.7, and pain disorders in humans, with gain-of-function mutations causing severe pain syndromes, and loss-of-function mutations causing congenital indifference to pain. Expression of sodium channel Nav1.8 in DRG neurons has also been shown to be essential for the manifestation of mutant Nav1.7-induced neuronal hyperexcitability. These findings have confirmed key roles of Nav1.7 and Nav1.8 in pain and identify these channels as novel targets for pain therapeutic development. Ranolazine preferentially blocks cardiac late sodium currents at concentrations that do not significantly reduce peak sodium current. Ranolazine also blocks wild-type Nav1.7 and Nav1.8 channels in a use-dependent manner. However, ranolazine's effects on gain-of-function mutations of Nav1.7 and on DRG neuron excitability have not been investigated. We used voltage- and current-clamp recordings to evaluate the hypothesis that ranolazine may be effective in regulating Nav1.7-induced DRG neuron hyperexcitability.

Results:

We show that ranolazine produces comparable block of peak and ramp currents of wild-type Nav1.7 and mutant Nav1.7 channels linked to Inherited Erythromelalgia and Paroxysmal Extreme Pain Disorder. We also show that ranolazine, at a clinically-relevant concentration, blocks high-frequency firing of DRG neurons expressing wild-type but not mutant channels.

Conclusions:

Our data suggest that ranalozine can attenuate hyperexcitability of DRG neurons over-expressing wild-type Nav1.7 channels, as occurs in acquired neuropathic and inflammatory pain, and thus merits further study as an alternative to existing non-selective sodium channel blockers.
Evaluating the control of HPAIV H5N1 in Vietnam: virus transmission within infected flocks reported before and after vaccination
Authors: Soares Magalhães Ricardo J , Pfeiffer Dirk U , Otte Joachim
Published: June 2010

Background

Currently, the highly pathogenic avian influenza virus (HPAIV) of the subtype H5N1 is believed to have reached an endemic cycle in Vietnam. We used routine surveillance data on HPAIV H5N1 poultry outbreaks in Vietnam to estimate and compare the within-flock reproductive number of infection (R

0
) for periods before (second epidemic wave, 2004-5; depopulation-based disease control) and during (fourth epidemic wave, beginning 2007; vaccination-based disease control) vaccination.

Results

Our results show that infected premises (IPs) in the initial (exponential) phases of outbreak periods have the highest R

0
estimates. The IPs reported during the outbreak period when depopulation-based disease control was implemented had higher R

0
estimates than IPs reported during the outbreak period when vaccination-based disease control was used. In the latter period, in some flocks of a defined size and species composition, within-flock transmission estimates were not significantly below the threshold for transmission (R

0
< 1).

Conclusions

Our results indicate that the current control policy based on depopulation plus vaccination has protected the majority of poultry flocks against infection. However, in some flocks the determinants associated with suboptimal protection need to be further investigated as these may explain the current pattern of infection in animal and human populations.
From project aid to sustainable HIV services: a case study from Zambia
Authors: Torpey Kwasi , Mwenda Lona , Thompson Catherine , Wamuwi Edgar , van Damme Wim
Published: June 2010

Introduction

Sustainable service delivery is a major challenge in the HIV response that is often not adequately addressed in project implementation. Sustainable strategies must be built into project design and implementation to enable HIV efforts to continue long after donor‐supported projects are completed.

Case description

This paper presents the experiences in operational sustainability of Family Health International's Zambia Prevention, Care and Treatment Partnership in Zambia, which is supported by the US President's Emergency Plan for AIDS Relief through United States Agency for International Development (October 2004 to September 2009). The partnership worked with Zambia's Ministry of Health to scale up HIV clinical services in five of the country's nine provinces, reaching 35 districts and 219 facilities. It provided technical and financial support from within the ministry's systems and structures. By completion of the project, 10 of the 35 districts had graduated beyond receiving ongoing technical support.

Discussion and evaluation

By working within the ministry's policies, structures and systems, the partnership was able to increase the ministry's capacity to add a comprehensive HIV service delivery component to its health services. Ministry structures were improved through renovations of health facilities, training of healthcare workers, procurement of essential equipment, and establishment of a quality assurance plan to ensure continued quality of care. The quality assurance tools were implemented by both the ministry and project staff as the foundation for technical graduation. Facilities that met all the quality criteria for more than six months were graduated from project technical support, as were districts where most supported facilities met the criteria. The district health offices then provided ongoing supervision of services. This predetermined “graduation” exit strategy, with buy in of the provincial and district health offices, set the stage for continued delivery of high‐quality HIV services.

Conclusions

Achieving operational sustainability in a resource‐limited setting is feasible. Developing and institutionalizing a quality assurance/quality improvement system is the basis on which facilities and districts can move beyond project support and, therefore, sustain services. Quality assurance/quality improvement tools should be based on national standards, and project implementation should use and improve existing health system structures.
Disassociated relation between plasma tumor necrosis factor-α, interleukin-6 and increased body weight in Amerindian women: A long-term prospective study of natural body weight variation and impaired glucose tolerance
Authors: Lindgärde Folke , Gottsäter Anders , Ahrén Bo
Published: June 2010

Background

Inflammatory cytokines are linked to obesity-related insulin resistance and may predict type 2 diabetes independently of obesity. We previously reported that a majority of a cohort of 73 non-diabetic women with normal plasma (p-)glucose with Amerindian heritage in Lima, Peru, during a 5-year period increased both body weight and p-glucose levels, yet p-insulin was unaltered. A high proportion of palmitoleic acid (16:1n-7) in serum (s) and systolic blood pressure (SBP) were independent predictors of high p-glucose. Whether cytokines also contributed is, however, not known.

Methods

During 5 years we prospectively investigated the relation between changed concentrations of p-tumor necrosis factor (TNF)-α, p-interleukin (IL)-6 and circulating insulin and glucose in relation to the natural variation of body weight. Study variables included anthropometric measurements, p-insulin, TNF-α, IL-6, SBP and the proportion of 16:1n-7 in s-fatty acid composition.

Results

Weight and waist differences correlated negatively to the difference in p-TNF-α but positively to differences in p-IL-6 and p-insulin, whereas the increase of p-glucose from baseline to follow-up did not correlate with changes in levels of the two cytokines. In multiple regression analysis changes of TNF-α and insulin contributed independently to the variance in weight. P-insulin at baseline and weight change were determinants of fasting p-insulin at follow-up. Multiple regression analysis revealed that weight change (t-value = - 2.42; P = 0.018) and waist change (t-value = 2.41; P = 0.019) together with S-16:1n-7 (p < 0.0001) and SBP (p = 0.0005) at baseline were significant predictors of p-glucose at follow-up.

Conclusion

Our prospective study of Amerindian women revealed disassociations between changes in p-TNF-α and p-IL-6 in relation to variation in body weight. A high proportion of s-16:1n-7, SBP at baseline together with weight and waist changes were independent predictors of p-glucose at follow-up. The exact role of the opposite effects and clinical impact of p-TNF-α and p-IL-6 on loss and gain of body weight and indirectly on the development of glucose intolerance is not known.
Phase II Study to Evaluate the Efficacy and Safety of Neoadjuvant Lapatinib Plus Paclitaxel in Patients With Inflammatory Breast Cancer
Authors: Boussen Hamouda , Cristofanilli Massimo , Zaks Tal , DeSilvio Michelle , Salazar Vanessa , Spector Neil
Published: June 2010

Purpose

We conducted a phase II, open-label, multicenter study to evaluate the efficacy, safety, and tolerability of daily lapatinib plus weekly paclitaxel in treatment-naïve patients with inflammatory breast cancer (IBC).

Patients and Methods

The primary end point was pathologic complete response (pCR). Secondary end points included combined clinical response rate (based on Response Evaluation Criteria in Solid Tumors (RECIST) criteria and clinically evaluable skin disease criteria). Patients were assigned to either cohort A (human epidermal growth factor receptor 2 [HER2] 2+ or 3+ by immunohistochemistry [IHC] or fluorescent in situ hybridization [FISH] –amplified ± epidermal growth factor receptor [EGFR] expression) or cohort B (HER2-negative/EGFR-positive). A subpopulation of cohort A considered HER2-positive by the current definition of overexpression (3+ by IHC or FISH-amplified) was also analyzed. Patients received lapatinib at 1,500 mg/d for 14 days, then lapatinib at 1,500 mg/d plus weekly paclitaxel (80 mg/m2) for 12 weeks, followed by surgical resection or additional chemotherapy.

Results

Forty-nine women were enrolled (cohort A, n = 42; cohort B, n = 7). Cohort B was terminated because of slow accrual and lack of efficacy observed in IBC patients with HER2-negative/EGFR-positive tumors enrolled onto the parallel study, EGF103009. pCR occurred in 18.2% (95% CI, 5.2% to 40.3%) of cohort A patients. Combined clinical response rate was 78.6% (95% CI, 63.2% to 89.7%) in all cohort A patients and 78.1% (95% CI, 60.0% to 90.7%) in the HER2-positive subset. Common adverse events included diarrhea, rash, alopecia, and nausea (> 50% of patients in both cohorts). The incidence of grade 3 diarrhea was 55%.

Conclusion

Lapatinib monotherapy for 14 days followed by lapatinib plus paclitaxel for 12 weeks provided clinical benefit in IBC patients with HER2-overexpressing tumors without unexpected toxicity.
Frizzled-5, a receptor for the synaptic organizer Wnt7a, regulates activity-mediated synaptogenesis
Authors: Sahores Macarena , Gibb Alasdair , Salinas Patricia C.
Published: June 2010

Wnt proteins play a crucial role in several aspects of neuronal circuit formation. Wnts can signal through different receptors including Frizzled, Ryk and Ror2. In the hippocampus, Wnt7a stimulates the formation of synapses; however, its receptor remains poorly characterized. Here, we demonstrate that Frizzled-5 (Fz5) is expressed during the peak of synaptogenesis in the mouse hippocampus. Fz5 is present in synaptosomes and colocalizes with the pre- and postsynaptic markers vGlut1 and PSD-95. Expression of Fz5 during early stages of synaptogenesis increases the number of presynaptic sites in hippocampal neurons. Conversely, Fz5 knockdown or the soluble Fz5-CRD domain (Fz5CRD), which binds to Wnt7a, block the ability of Wnt7a to stimulate synaptogenesis. Increased neuronal activity induced by K+ depolarization or by high-frequency stimulation (HFS), known to induce synapse formation, raises the levels of Fz5 at the cell surface. Importantly, both stimuli increase the localization of Fz5 at synapses, an effect that is blocked by Wnt antagonists or Fz5CRD. Conversely, low-frequency stimulation, which reduces the number of synapses, decreases the levels of surface Fz5 and the percentage of synapses containing the receptor. Interestingly, Fz5CRD abolishes HFS-induced synapse formation. Our results indicate that Fz5 mediates the synaptogenic effect of Wnt7a and that its localization to synapses is regulated by neuronal activity, a process that depends on endogenous Wnts. These findings support a model where neuronal activity and Wnts increase the responsiveness of neurons to Wnt signalling by recruiting Fz5 receptor at synaptic sites.
The Drosophila serine protease homologue Scarface regulates JNK signalling in a negative-feedback loop during epithelial morphogenesis
Authors: Rousset Raphaël , Bono-Lauriol Sophie , Gettings Melanie , Suzanne Magali , Spéder Pauline , Noselli Stéphane
Published: June 2010

In Drosophila melanogaster, dorsal closure is a model of tissue morphogenesis leading to the dorsal migration and sealing of the embryonic ectoderm. The activation of the JNK signal transduction pathway, specifically in the leading edge cells, is essential to this process. In a genome-wide microarray screen, we identified new JNK target genes during dorsal closure. One of them is the gene scarface (scaf), which belongs to the large family of trypsin-like serine proteases. Some proteins of this family, like Scaf, bear an inactive catalytic site, representing a subgroup of serine protease homologues (SPH) whose functions are poorly understood. Here, we show that scaf is a general transcriptional target of the JNK pathway coding for a secreted SPH. scaf loss-of-function induces defects in JNK-controlled morphogenetic events such as embryonic dorsal closure and adult male terminalia rotation. Live imaging of the latter process reveals that, like for dorsal closure, JNK directs the dorsal fusion of two epithelial layers in the pupal genital disc. Genetic data show that scaf loss-of-function mimics JNK over-activity. Moreover, scaf ectopic expression aggravates the effect of the JNK negative regulator puc on male genitalia rotation. We finally demonstrate that scaf acts as an antagonist by negatively regulating JNK activity. Overall, our results identify the SPH-encoding gene scaf as a new transcriptional target of JNK signalling and reveal the first secreted regulator of the JNK pathway acting in a negative-feedback loop during epithelial morphogenesis.
An electric powertrain modelling of a fuel cell hybrid electric vehicle and development of a power distribution algorithm using H∞ control
Authors: Ryu J-H , Lee H-J , Sunwoo M-H
Published: June 2010

This paper presents an electric powertrain model of a parallel-type fuel cell hybrid electric vehicle (FCHEV) and its robust H∞ controller for efficient power distribution between a fuel cell and a battery. The electric powertrain of the parallel-type FCHEV is composed of a fuel cell stack system, a d.c.-to-d.c. converter, and a battery. The fuel cell stack system is connected to the battery through the d.c.-to-d.c. converter, which is a key component for power distribution between the fuel cell and the battery. In this study, the electric powertrain model of the FCHEV was derived from the dynamic differential equations of the equivalent-circuit model that describes the electric powertrain. Using this model, the robust H∞ controller was designed to control the power distribution between the fuel cell and the battery efficiently. Finally, the results of driving-cycle simulation verified the performance of the proposed robust H∞ controller.
A predictive capability for the aerodynamic deformation of convertible car roofs
Authors: Knight J J , Lucey A D , Shaw C T
Published: June 2010

The flow-induced deformation of a membrane in a flow is studied using experimental and computational approaches in a configuration that represents the effect of the aerodynamic load on a convertible car roof. The computational method couples a commercial computational fluid dynamics code with an in-house structural code to predict membrane deformation. A converged statically deformed state, within 1 per cent difference in the displacement variable, is reached after three iterations between the fluid and structural codes. The predictions of membrane deformation are shown to agree well with the experimental results. The key outcome is the demonstration of a methodology that will be useful in the engineering design of convertible car roofs.
Batter's behaviour during training when facing a bowling machine and when facing a bowler
Authors: Cork A , Justham L , West A A
Published: June 2010

In cricket, expert batters must develop anticipatory skills to enable them to respond effectively to a delivery by the bowler. The batter is required to judge the delivery and to move into an appropriate position to respond to it within a limited time (i.e. the delivery transit time can be as little as 450ms for fast-paced bowlers). In training, the batter therefore needs to face numerous deliveries to hone this skill. However, because of the natural variation that occurs in bowling and the high impact experienced by the bowler, bowling machines are often employed to provide numerous similar deliveries for practice and to minimize the occurrence of overuse injuries to the bowler. The purpose of the study presented within this paper was to investigate how the batter reacts differently when facing a bowler and when facing a bowling machine. In a controlled single-subject pilot study a batter faced an unfamiliar bowler and also faced a bowling machine. The batter and the bowler or bowling machine were synchronously filmed using high-speed video cameras operating at 500frames/s and the reaction of the batter was analysed under both conditions. It was seen that the batter lifted his bat backwards significantly earlier (0.999s as opposed to 0.838s before ball release) and lifted his front foot significantly later (0.002s as opposed to 0.153s before ball release) when facing the bowling machine and when facing the bowler respectively.
Mass Spectrometric Analysis, Automated Identification and Complete Annotation of O-Linked Glycopeptides
Authors: Darula Zsuzsa , Chalkley Robert J. , Baker Peter , Burlingame Alma L. , Medzihradszky Katalin F.
Published: June 2010

Complex mixtures containing O-linked glycopeptides bearing SA1–0GalGalNAc structures, or single GalNAc units were subjected to collision-induced dissociation (CID) and electron transfer dissociation (ETD) analysis on a linear ion trap-Orbitrap mass spectrometer and the resulting data was analyzed using the Protein Prospector software. An overview of the structural information provided by the different fragmentation techniques, as well as their limitations, is presented. We illustrate the importance of the complementary information in the mass spectrometry survey scans as well as the different tandem mass spectrometry techniques. We also present some unique features offered by Protein Prospector that are advantageous in glycopeptide analysis: (i) considering a modification that will produce a neutral loss, without “labeling” the original modification site; (ii) merging CID and ETD search results; (iii) permitting the comparison of different modification site-assignments. Although these data were obtained from secreted glycopeptides, the observations and conclusions are also valid for the intracellular regulatory O-GlcNAc modification.
Petroleomics: A Test Bed for Ultra-High-Resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry
Authors: Marshall Alan G. , Blakney Greg T. , Beu Steven C. , Hendrickson Christopher L. , McKenna Amy M. , Purcell Jeremiah M. , Rodgers Ryan P. , Xian Feng
Published: June 2010

Within a relative abundance dynamic range of ~10,000: 1, the world's most compositionally complex organic mixture is petroleum crude oil. As such, it provides the most challenging target for mass spectral resolution and identification of molecules below m/z 2000. The mass “splits” in petroleum include most of those that also appear in proteomics, metabolomics and other complex organic mixture analysis. Therefore, petroleum provides an excellent test bed for optimizing mass spectrometer performance in general. The presence of multiple elemental compositions spanning less than 1 Da in mass facilitates mapping and correction of rf phase variation across a Fourier transform ion cyclotron resonance mass spectrum, as well as exposing otherwise inaccessible systematic mass deviations, for additional improvement in mass resolving power and mass accuracy by a factor of up to 5. Internal mass calibration, combined with systematic peak assignment for successive homologous series, enables automated elemental composition assignment of tens of thousands of peaks in a single mass spectrum.
Development of Multi-Turn Time-of-Flight Mass Spectrometers and Their Applications
Authors: Toyoda Michisato
Published: June 2010

The mass resolution of a time-of-flight (ToF) mass spectrometer is directly proportional to its total flight path length. We have developed multi-turn ToF mass spectrometers, where ions are stored in a fixed orbit within electrostatic sectors and allowed to propagate the said orbit numerous times. With each successive orbit, the flight path is correspondingly increasing. The first multi-turn ToF mass spectrometer, the MULTUM Linear plus, was developed for cometary exploration. The spectrometer consists of four cylindrical electrostatic sectors and 28 electrostatic quadrupole lenses. The size of the analyzer is 40 cm square. Mass resolution is demonstrated to increase according to the number of ion cycles. A mass resolution of greater than 350,000 was achieved after 501.5 cycles. Another multi-turn ToF mass spectrometer, the MULTUM II, which consists of only four toroidal electrostatic sectors, was also developed in an effort to reduce the number of quadrupole lenses. We are developing various types of mass spectrometer based on the MULTUM II technology, a ToF/ToF mass spectrometer “MULTUM-TOF/TOF”, a stigmatic imaging mass spectrometer “MULTUM-IMG” and miniature mass spectrometers of high mass resolving power, the “MULTUM-S” series.
Challenging Developments in Three Decades of Accelerator Mass Spectrometry at ETH: From Large Particle Accelerators to Table Size Instruments
Authors: Suter Martin
Published: June 2010

Accelerator mass spectrometry (AMS) was invented for the detection of radiocarbon at natural isotopic concentrations (10−12 to 10−15) more than 30 years ago. Meanwhile, this method has also been applied for the analysis of many other long-lived radioisotopes, which are found at very low concentrations. The first investigations were made at large tandem accelerators, originally built for nuclear physics research and operating at voltages of 6–12 MV. Today, dedicated instruments are mostly used for AMS, which are optimised for associated applications. In the past 15 years, a new generation of much smaller instruments has been developed. For many years it was believed that accelerators with voltages of 2MV or higher are needed to eliminate the molecular interferences. At these energies the ions are predominantly stripped to charge state 3+, thereby removing the binding electrons of the molecules. In contrast, the new compact facilities use 1+ or 2+ ions. In this case, the molecular destruction process is based on molecule–atom collisions in the gas cell. The cross sections for this destruction are sufficiently large that the intensity of molecular components such as 12CH2 and 13CH can be reduced by 10 orders of magnitude. These new facilities can be built much smaller due to the lower energies. Universal instruments providing analysis for many isotopes over the whole range of periodic table have a space requirement of about 4 × 6 m2; dedicated radiocarbon facilities based on a 200 kV accelerator have a footprint of about 2.5 × 3 m2. This smallest category of instruments use special technologies: the high voltage terminal with the gas stripper canal is vacuum insulated and the gas is pumped to ground potential through a ceramic pipe. A conventional 200 kV power supply provides the terminal voltage from outside. A review of this new generation of compact AMS facilities is given. Design considerations and performance of these new instruments will be presented. With these developments, new AMS instruments are not much larger than conventional mass spectrometers, allowing a significant reduction in cost.
American Government Finance in the Long Run: 1790 to 1990
Authors: Wallis John Joseph
Published: June 2010

Government in America has gone through three distinct fiscal systems in the last two hundred years. Each system utilized a dominant revenue source, and had a distinctly active level of government. The changing structure of government by level seems to be related to changing revenue structures. When new taxes become important, the relative importance of each level of government changes. On the other hand, growth in the overall size of government is not directly related to the structure of revenues or the distribution of activity by level of government. Government growth is the result of long term commitments to provide education, transportation, social welfare services, old age security, and military forces.
Policy Watch: The Repeal of Glass-Steagall and the Advent of Broad Banking
Authors: Barth James R , Dan Brumbaugh R , Wilcox James A
Published: June 2010

Enactment of the Gramm-Leach-Bliley Act (GLBA) in November 1999 effectively repealed the long-standing prohibitions on the mixing of banking with securities or insurance businesses and thus permits “broad banking.” We attribute repeal of these prohibitions to the increasingly persuasive evidence from academic studies of the pre-Glass-Steagall era, the recent favorable experience in the United States following partial deregulation of banking activities, the experience of banking systems abroad with broader scopes for banking activities, and rapid technological change in telecommunications and data processing. How regulators will in practice coordinate their efforts so that the safety and soundness of the banking system is maintained efficiently remains to be seen.
Data Watch: The U.S. National Income and Product Accounts
Authors: Popkin Joel
Published: June 2010

GDP is arguably the most widely used economic statistic. It is part of the National Income and Product Accounts (NIPAs). The concepts, methods and source data for the NIPAs are described in this article. It contains citations to more detailed information obtainable from the publications and web sites of the U.S. Bureau of Economic Analysis, the agency responsible for the NIPAs. A brief history describes the evolution of the accounts. It explains the growing congruence between the U.S. accounts and the UN's System of National Accounts (SNA). The integration of financial and satellite accounts into the NIPAs is summarized.
Collective Action and the Evolution of Social Norms
Authors: Ostrom Elinor
Published: June 2010

I assume multiple types of players--“rational egoists,” as well as “conditional cooperators” and “willing punishers”--in models of nonmarket behavior. I use an indirect evolutionary approach to explain how multiple types of players could survive and flourish in social dilemma situations. Contextual variables that enhance knowledge about past behavior assist in explaining the origin of collective action. Among the important contextual variables are types of goods, types of groups, and rules that groups use to provide and allocate goods. Finally, I reexamine a series of design principles that were derived earlier from an examination of extensive case materials.
Vickrey Auctions in Practice: From Nineteenth-Century Philately to Twenty-First-Century E-Commerce
Authors: Lucking-Reiley David
Published: June 2010

William Vickrey (1961) proposed an auction mechanism in which bidders submit sealed bids, and the highest bidder wins the good in return for payment of the second-highest bid amount. For decades, economists have credited Vickrey with inventing this auction format, and have believed that the Vickrey auction is rarely used in practice. This paper presents evidence that Vickrey auctions have long been the predominant auction format for mail sales of collectible postage stamps. Stamp auctioneers developed this auction format on their own, as early as 1893, even before Vickrey was born.
The Political Economy of the Budget Surplus in the United States
Authors: Alesina Alberto
Published: June 2010

Current surpluses in the U.S. have been achieved by a combination of a strong economy, low interest rates, and sharp cuts in defense spending. These surpluses follow a period (the 1980s) of rather exceptional budget deficit. This paper investigates the origin, size, and expected future patterns of the U.S. budget balance. It discusses how different political forces may generate alternative fiscal scenarios for the U.S. in the next decade.
The Economics of Sports Facilities and Their Communities
Authors: Siegfried John , Zimbalist Andrew
Published: June 2010

Since the 1950s, taxpayers have been the primary investors in stadia built for the use of privately-owned professional sports teams. Team owners have argued that sports facilities boost local economic activity; however, economic reasoning and empirical evidence suggest the opposite. Public support for stadia is also driven by demand for community image, and owners of sports teams supply a scarce input into image enhancement--participation in the major league--for which they have been able to extract monopoly rents from dispersed taxpayers. We suggest reforms to dissipate the monopoly sports leagues exercise when negotiating with host communities for their teams.
Beyond Computation: Information Technology, Organizational Transformation and Business Performance
Authors: Brynjolfsson Erik , Hitt Lorin M
Published: June 2010

To understand the economic value of computers, one must broaden the traditional definition of both the technology and its effects. Case studies and firm-level econometric evidence suggest that: 1) organizational “investments” have a large influence on the value of IT investments; and 2) the benefits of IT investment are often intangible and disproportionately difficult to measure. Our analysis suggests that the link between IT and increased productivity emerged well before the recent surge in the aggregate productivity statistics and that the current macroeconomic productivity revival may in part reflect the contributions of intangible capital accumulated in the past.
Does the “New Economy” Measure up to the Great Inventions of the Past?
Authors: Gordon Robert J
Published: June 2010

During the four years 1995-99 U.S. productivity growth experienced a strong revival and achieved growth rates exceeding that of the “golden age” of 1913-72. Accordingly many observers have declared the “New Economy” to be an Industrial Revolution even more important than the Second Industrial Revolution of 1860-1900, which made the golden age of productivity growth possible. This paper dissects the recent productivity revival, subtracts out a cyclical component, and concludes that there is no revival of the productivity growth trend in the 88 percent of the private economy lying outside of the durables manufacturing sector. The paper explains this surprising finding by pointing to limitations in computers and the internet in comparison with the great inventions of the past.
The Impact of NAFTA on the United States
Authors: Burfisher Mary E , Robinson Sherman , Thierfelder Karen
Published: June 2010

We describe the main economic arguments posed for and against the North American Free Trade Agreement (NAFTA) during the U.S. policy debate. To evaluate these arguments, we analyze recent trade data and survey post-NAFTA studies. We find that both the U.S. and Mexico benefit from NAFTA, with much larger relative benefits for Mexico. NAFTA also has had little effect on the U.S. labor market. These results confirm the consensus opinion of economists at the time of the debate. Finally, studies find that trade creation greatly exceeds trade diversion in the region under NAFTA, especially in intermediate goods.
The Venture Capital Revolution
Authors: Gompers Paul , Lerner Josh
Published: June 2010

Venture capital has emerged as an important intermediary in financial markets, providing capital to young high-technology firms that might have otherwise gone unfunded. Venture capitalists have developed a variety of mechanisms to overcome the problems that emerge at each stage of the investment process. At the same time, the venture capital process is also subject to various pathologies from time to time, which can create problems for investors or entrepreneurs. This article reviews the recent empirical literature on these organizations and points out area where further research is needed.
Distinguished Lecture on Economics in Government—Exchange Rate Regimes: Is the Bipolar View Correct?
Authors: Fischer Stanley
Published: June 2010

The bipolar or two-corner solution view of exchange rates is that intermediate policy regimes between hard pegs and floating are not sustainable. This paper argues that the proponents of the bipolar view have probably exaggerated their point. The right statement is that for countries open to international capital flows, softly pegged exchange rates are crisis-prone and not sustainable over long periods. However, a wide variety of flexible rate arrangements remains possible. Monetary and exchange rate policy in most countries should not and will not be indifferent to exchange rate movements.
Bridging the Trade-Environment Divide
Authors: Esty Daniel C
Published: June 2010

Perceived conflict between trade liberalization and environmental protection can be traced to a number of issues. Some tensions relate to the environmental Kuznets curve and whether economic growth yields environmental benefits. Other concerns arise from efforts to address transboundary externalities and disputes over the role of trade measures as an environmental enforcement tool. Another set of issues centers on the risk of a race-toward-the-bottom regulatory dynamic and the limits of legitimate comparative advantage. This paper argues that, in an ecologically and economically interdependent world, trade and environmental policies are inescapably linked as a matter of descriptive reality and normative necessity.
GARCH 101: The Use of ARCH/GARCH Models in Applied Econometrics
Authors: Engle Robert
Published: June 2010

ARCH and GARCH models have become important tools in the analysis of time series data, particularly in financial applications. These models are especially useful when the goal of the study is to analyze and forecast volatility. This paper gives the motivation behind the simplest GARCH model and illustrates its usefulness in examining portfolio risk. Extensions are briefly discussed.