bluuebunny/crossref_metadata_2025 huggingface dataset:
Well-Being in Dinka Refugee Women of Southern Sudan
Authors: Baird Martha B. , Boyle Joyceen S.
Published: November 2011

The purpose of this study was to understand the health and well-being of Sudanese refugee women who were resettled with their children to the United States. The design was an interpretive ethnography using individual interviews and participant observation with extensive field notes. The findings describe personal factors as well as community and social conditions that influenced the health and well-being of the refugee women and their families. These influences are captured in the three themes that emerged from the study: (1) liminality—living between two cultures, (2) self-support—standing on our own two legs, and (3) hope for the future. These themes describe a process of how refugee women achieve well-being in the transition to a new country and culture. The study contributes to our theoretical understanding of how to develop culturally congruent interventions for resettled refugees.
Perceptions of Health and Well-Being Held by Native Hawaiian Migrants
Authors: Lassetter Jane H. , Callister Lynn C. , Miyamoto Shemnon Z.
Published: November 2011

Background and Purpose: Migration is often a challenging process. Native Hawaiians migrate from Hawaii to Las Vegas at an impressive rate, but no research has explored how migration affects their health and well-being. The purpose was to describe how Native Hawaiians in Las Vegas perceive their health and well-being and any changes therein since migrating. Design: Using a qualitative descriptive design, 27 participants took part in semistructured interviews. Findings/Results: Most participants perceived no changes in health and minor changes in well-being. Many maintained their well-being by adapting valued activities to their new circumstances. However, 5 participants were deeply burdened by life in Las Vegas or longing for Hawaii, and their well-being suffered. They tended to identify barriers to well-being rather than ways to foster it. Conclusion: Health care providers can help Native Hawaiian migrants by encouraging early access to the health care system in their new location and facilitating participation in helpful, adaptive behaviors.
Total Ischemia Time Alters the Longitudinal and Circumferential Shortening of the Right Ventricle in Transplanted Hearts
Authors: Ahlgren Bryan , Puskas Ferenc , Seres Tamas
Published: November 2011

Objectives. Ischemia time is a risk factor for mortality and right ventricular (RV) failure after heart transplantation. The purpose of this study was to determine the effect of ischemia time on known transesophageal echocardiography (TEE) parameters of RV function and on a novel quantitative measurement of RV circumferential shortening. Methods. Right and left ventricular (LV) function was evaluated retrospectively in 20 consecutive patients after heart transplant using known TEE parameters as well as a quantitative measurement of circumferential contraction. The control group consisted of 20 patients undergoing coronary artery bypass grafting (CABG) with no documented RV dysfunction. Results. Posttransplant TEE parameters of RV function were depressed compared with post–cardiopulmonary bypass CABG patients. Significant correlation was observed between tricuspid annular planar systolic excursion, basal, mid, and global circumferential shortening and total ischemia time. Conclusion. Total ischemia time of the transplanted heart may play a role in deterioration of longitudinal and circumferential shortening of the RV.
Progressive resistance training did not improve walking but can improve muscle performance, quality of life and fatigue in adults with multiple sclerosis: a randomized controlled trial
Authors: Dodd KJ , Taylor NF , Shields N , Prasad D , McDonald E , Gillon A
Published: November 2011

Background: Few high-quality trials have examined the effects of progressive resistance training (PRT) on people with multiple sclerosis (MS).

Objective: To determine the effectiveness of PRT for people with MS, focusing on improving the gait deficits common in this population.

Methods: Using a single blind randomized controlled trial, people with relapsing–remitting MS were randomly allocated to either a PRT program targeting the lower limb muscles twice a week for 10 weeks ( n = 36), or usual care plus an attention and social program conducted once a week for 10 weeks ( n = 35). Outcomes were recorded at baseline, week 10 and week 22.

Results: Participants attended 92% of training sessions, with no serious adverse events. At 10 weeks, no differences were detected in walking performance. However, compared with the comparison group PRT demonstrated increased leg press strength (16.8%, SD 4.5), increased reverse leg press strength (29.8%, SD 12.7), and increased muscle endurance of the reverse leg press (38.7%, SD 32.8). Improvements in favor of PRT were also found for physical fatigue (Mean difference −3.9 units, 95%CI −6.6 to −1.3), and the physical health domain of quality of life (Mean difference 1.5 units, 95%CI 0.1 to 2.9). At week 22 almost no between-group differences remained.

Conclusion: PRT is a relatively safe intervention that can have short-term effects on reducing physical fatigue, increasing muscle endurance and can lead to small improvements in muscle strength and quality of life in people with relapsing–remitting MS. However, no improvements in walking performance were observed and benefits do not appear to persist if training is completely stopped.
Events of the Body Politic: A Nancian Reading of Asylum-seekers’ Bodily Choreographies and Resistance
Authors: Puumala Eeva , Väyrynen Tarja , Kynsilehto Anitta , Pehkonen Samu
Published: November 2011

This article thinks the place of the body, agency and movement in politics through the body of the asylum-seeker. Asylum-seekers do not have ample space to politically voice their experiences, but their bodies and ways of taking agency are fluid. The Agambenian idea of exceptional space and bare life privileges the power of the sovereign, leaving little space for agency for its subjects. It leads to an impasse, as it offers no viable option of thinking the possibilities of opposing sovereign rule. We have resorted to Jean-Luc Nancy’s philosophy in order to read to the contrary: to sketch the potential of the body to move beyond the reach of sovereign power and to communicate itself and its relations to others. The untenability of the sovereign subject pointed to by Nancy’s ontology of bodies allows seeing the asylum-seeker’s body as expressive and moving body that reorganizes its relations to others and turns it to an active agent from which events of the body politic emerge. With its focus on crisscrossing movement of the body and between bodies, the notion of choreography assists us in envisioning that the space for political agency and community do not pre-exist, but are articulated through bodies’ movements. We argue that either purely textual analysis or focus on administrative rationality is bound to leave possible expressions of political agency aside, and thus to ignore the challenge the bodily choreographies of asylum-seekers pose to political theory. We illustrate our argument with vignettes from Fernand Melgar’s 2008 documentary film The Fortress.
Using rival effects to identify synergies and improve merger typologies
Authors: Clougherty Joseph A. , Duso Tomaso
Published: November 2011

Differentiation of collusive and efficiency-based synergies in horizontal mergers has proven difficult. The authors propose a theory-backed methodological approach to classify mergers that yields greater information on merger types and merger effects. Moreover, the methodological approach distinguishes between mergers characterized largely by collusion-based synergies and those characterized largely by efficiency-based synergies. Crucial to the proposed method is that it considers the impact of merger events not only on merging firms, as is common in the literature, but also on non-merging rivals. The authors demonstrate how the proposed approach clarifies the nature of merger activity through an event-study procedure based on stock market data on samples of large horizontal mergers drawn from the US and UK (an Anglo-American sub-sample) and from the European continent the authors demonstrate how the proposed schematic clarifies the nature of merger activity.
Climate on Cable
Authors: Feldman Lauren , Maibach Edward W. , Roser-Renouf Connie , Leiserowitz Anthony
Published: November 2011

This study examines climate change coverage on the three major cable news channels and assesses the relationship between viewership of these channels and beliefs about global warming. Evidence from a content analysis of climate change coverage on Fox News, CNN, and MSNBC during 2007 and 2008 demonstrates that Fox takes a more dismissive tone toward climate change than CNN and MSNBC. Fox also interviews a greater ratio of climate change doubters to believers. An analysis of 2008 survey data from a nationally representative sample of U.S. adults finds a negative association between Fox News viewership and acceptance of global warming, even after controlling for numerous potential confounding factors. Conversely, viewing CNN and MSNBC is associated with greater acceptance of global warming. Further analyses reveal that the relationship between cable news viewership (both Fox and CNN/MSNBC) and global warming acceptance is stronger among Republicans than among Democrats. That is, the views of Republicans are strongly linked with the news outlet they watch, regardless of how well that outlet aligns with their political predispositions. In contrast, Democrats don’t vary much in their beliefs as a function of cable news use. This asymmetry suggests that some Republicans, who as a group tend to be predisposed toward global warming skepticism, are less skeptical when exposed to information on the reality and urgency of climate change.
Comparison of the Efficacy Between Oral Rinse, Oral Gargle, and Oral Spray
Authors: Lin Carren Teh Sui , Raman Rajagopalan
Published: November 2011

Introduction and Aims: Patients with sore throats are often treated with oral gargles or oral sprays. Some may rinse instead of gargle, leading to unsatisfactory outcome. The authors studied the efficacy of oral rinses, gargles, and sprays and the effect of Friedman palate position on the outcome. Methods: Ten subjects used specially prepared solutions to rinse, gargle, and then spray their oral cavities at 2-hour intervals. The blue dye indicated the areas stained by the solution, which were scored. Results: Although there was no difference in reaching the oropharynx between the gargles and sprays, they were both better than were the oral rinses ( P < .001). The difference in Friedman palate position did not have an effect on the efficacy of the different modalities. Conclusion: Oral gargles and sprays have been shown to be significantly better than are oral rinses if the oropharynx is the targeted site, and the size of the oral airway does not impede their efficacy.
mTORC1 and mTORC2 differentially regulate homeostasis of neoplastic and non-neoplastic human mast cells
Authors: Smrž Daniel , Kim Mi-Sun , Zhang Shuling , Mock Beverly A. , Smržová Šárka , DuBois Wendy , Simakova Olga , Maric Irina , Wilson Todd M. , Metcalfe Dean D. , Gilfillan Alasdair M.
Published: November 2011

Increased mast cell burden is observed in the inflamed tissues and affected organs and tissues of patients with mast cell proliferative disorders. However, normal mast cells participate in host defense, so approaches to preferentially target clonally expanding mast cells are needed. We found that mammalian target of rapamycin complex 1 (mTORC1) and 2 (mTORC2) are up-regulated in neoplastic and developing immature mast cells compared with their terminally differentiated counterparts. Elevated mTOR mRNA was also observed in bone marrow mononuclear cells of patients exhibiting mast-cell hyperplasia. Selective inhibition of mTORC1 and mTORC2 through genetic and pharmacologic manipulation revealed that, whereas mTORC1 may contribute to mast-cell survival, mTORC2 was only critical for homeostasis of neoplastic and dividing immature mast cells. The cytostatic effect of mTORC2 down-regulation in proliferating mast cells was determined to be via inhibition of cell-cycle progression. Because mTORC2 was observed to play little role in the homeostasis of differentiated, nonproliferating, mature mast cells, these data provide a rationale for adopting a targeted approaching selectively inhibiting mTORC2 to effectively reduce the proliferation of mast cells associated with inflammation and disorders of mast cell proliferation while leaving normal differentiated mast cells largely unaffected.
Inactivation of polycomb repressive complex 2 components in myeloproliferative and myelodysplastic/myeloproliferative neoplasms
Authors: Score Joannah , Hidalgo-Curtis Claire , Jones Amy V. , Winkelmann Nils , Skinner Alison , Ward Daniel , Zoi Katerina , Ernst Thomas , Stegelmann Frank , Döhner Konstanze , Chase Andrew , Cross Nicholas C. P.
Published: November 2011

The polycomb repressive complex 2 (PRC2) is a highly conserved histone H3 lysine 27 methyltransferase that regulates the expression of developmental genes. Inactivating mutations of the catalytic component of PRC2, EZH2, are seen in myeloid disorders. We reasoned that the other 2 core PRC2 components, SUZ12 and EED, may also be mutational targets in these diseases, as well as associated factors such as JARID2. SUZ12 mutations were identified in 1 of 2 patients with myelodysplastic syndrome/myeloproliferative neoplasms with 17q acquired uniparental disomy and in 2 of 2 myelofibrosis cases with focal 17q11 deletions. All 3 were missense mutations affecting the highly conserved VEFS domain. Analysis of a further 146 myelodysplastic syndrome/myeloproliferative neoplasm patients revealed an additional VEFS domain mutant, yielding a total mutation frequency of 1.4% (2 of 148). We did not find mutations of JARID2 or EED in association with acquired uniparental disomy for chromosome 6p or 11q, respectively; however, screening unselected cases identified missense mutations in EED (1 of 148; 1%) and JARID2 (3 of 148; 2%). All 3 SUZ12 mutations tested and the EED mutation reduced PRC2 histone methyltransferase activity in vitro, demonstrating that PRC2 function may be compromised in myeloid disorders by mutation of distinct genes.
Rituximab blocks protective serologic response to influenza A (H1N1) 2009 vaccination in lymphoma patients during or within 6 months after treatment
Authors: Yri Olav Erich , Torfoss Dag , Hungnes Olav , Tierens Anne , Waalen Kristian , Nordøy Tone , Dudman Susanne , Kilander Anette , Wader Karin Fahl , Østenstad Bjørn , Ekanger Roald , Meyer Peter , Kolstad Arne
Published: November 2011

Cancer patients are often encouraged to receive seasonal influenza vaccination. The monoclonal antibody rituximab is widely used in treatment of non-Hodgkin lymphoma. This results in a prolonged depletion of normal B cells, which might impair humoral responses. The aim of the present study was to investigate whether lymphoma patients undergoing rituximab-containing treatment regimens or having received such regimens within the past 6 months were able to mount protective antibody responses to the influenza A(H1N1) 2009 virus vaccine Pandemrix during the 2009 “swine flu” pandemic. Contrary to the control group, where 82% responded adequately to the vaccine, none of the 67 patients achieved protective antibody titers, suggesting that lymphoma patients receiving rituximab-containing regimens might not benefit from this vaccine. It is important that doctors who care for such patients are aware that they may fail to respond not only to the influenza vaccine, but also to other common vaccines.
Molecular cloning, expression and biochemical characterisation of a cold-adapted novel recombinant chitinase from Glaciozyma antarctica PI12
Authors: Ramli Aizi NorMazila , Mahadi Nor Muhammad , Rabu Amir , Murad Abdul MunirAbdul , Bakar Farah DibaAbu , Illias Rosli Md
Published: November 2011

Background

Cold-adapted enzymes are proteins produced by psychrophilic organisms that display a high catalytic efficiency at extremely low temperatures. Chitin consists of the insoluble homopolysaccharide β-(1, 4)-linked N-acetylglucosamine, which is the second most abundant biopolymer found in nature. Chitinases (EC 3.2.1.14) play an important role in chitin recycling in nature. Biodegradation of chitin by the action of cold-adapted chitinases offers significant advantages in industrial applications such as the treatment of chitin-rich waste at low temperatures, the biocontrol of phytopathogens in cold environments and the biocontrol of microbial spoilage of refrigerated food.

Results

A gene encoding a cold-adapted chitinase (CHI II) from Glaciozyma antarctica PI12 was isolated using Rapid Amplification of cDNA Ends (RACE) and RT-PCR techniques. The isolated gene was successfully expressed in the Pichia pastoris expression system. Analysis of the nucleotide sequence revealed the presence of an open reading frame of 1,215 bp, which encodes a 404 amino acid protein. The recombinant chitinase was secreted into the medium when induced with 1% methanol in BMMY medium at 25°C. The purified recombinant chitinase exhibited two bands, corresponding to the non-glycosylated and glycosylated proteins, by SDS-PAGE with molecular masses of approximately 39 and 50 kDa, respectively. The enzyme displayed an acidic pH characteristic with an optimum pH at 4.0 and an optimum temperature at 15°C. The enzyme was stable between pH 3.0-4.5 and was able to retain its activity from 5 to 25°C. The presence of K+, Mn2+ and Co2+ ions increased the enzyme activity up to 20%. Analysis of the insoluble substrates showed that the purified recombinant chitinase had a strong affinity towards colloidal chitin and little effect on glycol chitosan. CHI II recombinant chitinase exhibited higher Vmax and Kcat values toward colloidal chitin than other substrates at low temperatures.

Conclusion

By taking advantage of its high activity at low temperatures and its acidic pH optimum, this recombinant chitinase will be valuable in various biotechnological applications under low temperature and acidic pH conditions.
Air pollution and anemia as risk factors for pneumonia in ecuadorian children: a retrospective cohort analysis
Authors: Harris Aaron M , Sempértegui Fernando , Estrella Bertha , Narváez Ximena , Egas Juan , Woodin Mark , Durant John L , Naumova Elena N , Griffiths Jeffrey K
Published: November 2011

Background

Ambient air pollution and malnutrition, particularly anemia, are risk factors for pneumonia, a leading cause of death in children under five. We simultaneously assessed these risk factors in Quito, Ecuador.

Methods

In 2005, we studied two socioeconomically similar neighborhoods in Quito: Lucha de los Pobres (LP) and Jaime Roldos (JR). LP had relatively high levels of air pollution (annual median PM2.5 = 20.4 μg/m3; NO2 = 29.5 μg/m3) compared to JR (annual median PM2.5 = 15.3 μg/m3; NO2 = 16.6 μg/m3). We enrolled 408 children from LP (more polluted) and 413 children from JR (less polluted). All subjects were aged 18-42 months. We obtained medical histories of prior physician visits and hospitalizations during the previous year, anthropometric nutrition data, hemoglobin levels, and hemoglobin oxygen saturation via oximetry.

Results

In anemic children, higher pollution exposure was significantly associated with pneumonia hospitalization (OR = 6.82, 95%CI = 1.45-32.00; P = 0.015). In non-anemic children, no difference in hospitalizations by pollution exposure status was detected (OR = 1.04, NS). Children exposed to higher levels of air pollution had more pneumonia hospitalizations (OR = 3.68, 1.09-12.44; P = 0.036), total respiratory illness (OR = 2.93, 95% CI 1.92-4.47; P < 0.001), stunting (OR = 1.88, 1.36-2.60; P < 0.001) and anemia (OR = 1.45, 1.09-1.93; P = 0.013) compared to children exposed to lower levels of air pollution. Also, children exposed to higher levels of air pollution had significantly lower oxygen saturation (92.2% ± 2.6% vs. 95.8% ± 2.2%; P < 0.0001), consistent with air pollution related dyshemoglobinemia.

Conclusions

Ambient air pollution is associated with rates of hospitalization for pneumonia and with physician's consultations for acute respiratory infections. Anemia may interact with air pollution to increase pneumonia hospitalizations. If confirmed in larger studies, improving nutrition-related anemia, as well as decreasing the levels of air pollution in Quito, may reduce pneumonia incidence.
Biomonitoring of bisphenol A concentrations in maternal and umbilical cord blood in regard to birth outcomes and adipokine expression: a birth cohort study in Taiwan
Authors: Chou Wei-Chun , Chen Jyh-Larng , Lin Chung-Fen , Chen Yi-Chun , Shih Feng-Cheng , Chuang Chun-Yu
Published: November 2011

Background

Bisphenol A (BPA) is a sealant and flux of plastic materials and has been determined to be an endocrine-disrupting chemical. Prenatal exposure to BPA can lead to substantial adverse effects on fetal growth and development. This study was conducted to assess BPA concentration in pregnant women and umbilical cord blood, and to investigate whether maternal BPA exposure affected fetal outcomes including lower birth weight (LBW), smaller size for gestational age (SGA), and high leptin (HLP) and low adiponectin (LAD) secretion.

Methods

We measured the BPA levels of maternal blood (n = 97) and umbilical cord blood (n = 97) with a high-performance liquid chromatography/UV detector. The protein secretion of leptin and adiponectin were separately determined using enzyme-linked immunosorbent assay. A logistic regression was performed to estimate the effects of maternal exposure to BPA on LBW, SGA, and adverse action of adipokines in newborns.

Results

The geometric means of BPA concentration in maternal blood and fetal cord blood were 2.5 ng/ml and 0.5 ng/ml, respectively. Elevated risks of LBW (OR 2.42, 95% confidence interval (CI) 1.72-3.36), SGA (OR 2.01, 95% CI 1.39-3.01), and adverse action of leptin (OR 1.67, 95% CI 1.12-2.25) and adiponectin (OR 1.25, 95% CI 1.52-3.97) were observed in male neonates in the highest quartile of maternal BPA exposure.

Conclusions

Elevated prenatal BPA exposure increased the risk of LBW, SGA, and adverse actions of adipokines in neonates, especially in male infants. These results provide further evidence that maternal exposure is correlated with adverse birth outcomes.
Novel genetic reassortants in H9N2 influenza A viruses and their diverse pathogenicity to mice
Authors: Bi Yuhai , Lu Lu , Li Jing , Yin Yanbo , Zhang Yi , Gao Huijie , Qin Zhuoming , Zeshan Basit , Liu Jinhua , Sun Lei , Liu Wenjun
Published: November 2011

Background

H9N2 influenza A viruses have undergone extensive reassortments in different host species, and could lead to the epidemics or pandemics with the potential emergence of novel viruses.

Methods

To understand the genetic and pathogenic features of early and current circulating H9N2 viruses, 15 representative H9N2 viruses isolated from diseased chickens in northern China between 1998 and 2010 were characterized and compared with all Chinese H9N2 viruses available in the NCBI database. Then, the representative viruses of different genotypes were selected to study the pathogenicity in mice with the aim to investigate the adaptation and the potential pathogenicity of the novel H9N2 reassortants to mammals.

Results

Our results demonstrated that most of the 15 isolates were reassortants and generated four novel genotypes (B62-B65), which incorporated the gene segments from Eurasian H9N2 lineage, North American H9N2 branch, and H5N1 viruses. It was noteworthy that the newly identified genotype B65 has been prevalent in China since 2007, and more importantly, different H9N2 influenza viruses displayed a diverse pathogenicity to mice. The isolates of the 2008-2010 epidemic (genotypes B55 and B65) were lowly infectious, while two representative viruses of genotypes B0 and G2 isolated from the late 1990s were highly pathogenic to mice. In addition, Ck/SD/LY-1/08 (genotype 63, containing H5N1-like NP and PA genes) was able to replicate well in mouse lungs with high virus titers but caused mild clinical signs.

Conclusion

Several lines of evidence indicated that the H9N2 influenza viruses constantly change their genetics and pathogenicity. Thus, the genetic evolution of H9N2 viruses and their pathogenicity to mammals should be closely monitored to prevent the emergence of novel pandemic viruses.
Protocol: methodology for chromatin immunoprecipitation (ChIP) in Chlamydomonas reinhardtii
Authors: Strenkert Daniela , Schmollinger Stefan , Schroda Michael
Published: November 2011

We report on a detailed chromatin immunoprecipitation (ChIP) protocol for the unicellular green alga Chlamydomonas reinhardtii. The protocol is suitable for the analysis of nucleosome occupancy, histone modifications and transcription factor binding sites at the level of mononucleosomes for targeted and genome-wide studies. We describe the optimization of conditions for crosslinking, chromatin fragmentation and antibody titer determination and provide recommendations and an example for the normalization of ChIP results as determined by real-time PCR.
The CUL3-KLHL18 ligase regulates mitotic entry and ubiquitylates Aurora-A
Authors: Moghe Saili , Jiang Fei , Miura Yoshie , Cerny Ronald L. , Tsai Ming-Ying , Furukawa Manabu
Published: November 2011

The cullin-RING family of ubiquitin ligases regulates diverse cellular functions, such as cell cycle control, via ubiquitylation of specific substrates. CUL3 targets its substrates through BTB proteins. Here we show that depletion of CUL3 and the BTB protein KLHL18 causes a delay in mitotic entry. Centrosomal activation of Aurora-A, a kinase whose activity is required for entry into mitosis, is also delayed in depleted cells. Moreover, we identify Aurora-A as a KLHL18-interacting partner. Overexpression of KLHL18 and CUL3 promotes Aurora-A ubiquitylation in vivo, and the CUL3-KLHL18-ROC1 ligase ubiquitylates Aurora-A in vitro. Our study reveals that the CUL3-KLHL18 ligase is required for timely entry into mitosis, as well as for the activation of Aurora-A at centrosomes. We propose that the CUL3-KLHL18 ligase regulates mitotic entry through an Aurora-A-dependent pathway.
Expression of hsp70, hsp90 and hsf1 in the reef coral Acropora digitifera under prospective acidified conditions over the next several decades
Authors: Nakamura Masako , Morita Masaya , Kurihara Haruko , Mitarai Satoshi
Published: November 2011

Ocean acidification is an ongoing threat for marine organisms due to the increasing atmospheric CO2 concentration. Seawater acidification has a serious impact on physiologic processes in marine organisms at all life stages. On the other hand, potential tolerance to external pH changes has been reported in coral larvae. Information about the possible mechanisms underlying such tolerance responses, however, is scarce. In the present study, we examined the effects of acidified seawater on the larvae of Acropora digitifera at the molecular level. We targeted two heat shock proteins, Hsp70 and Hsp90, and a heat shock transcription factor, Hsf1, because of their importance in stress responses and in early life developmental stages. Coral larvae were maintained under the ambient and elevated CO2 conditions that are expected to occur within next 100 years, and then we evaluated the expression of hsps and hsf1 by quantitative real-time polymerase chain reaction (PCR). Expression levels of these molecules significantly differed among target genes, but they did not change significantly between CO2 conditions. These findings indicate that the expression of hsps is not changed due to external pH changes, and suggest that tolerance to acidified seawater in coral larvae may not be related to hsp expression.
Research Note—Performance-Based Advertising: Advertising as Signals of Product Quality
Authors: Feng Juan , Xie Jinhong
Published: November 2011

Performance-based advertising is becoming increasingly popular in the online advertising industry, where advertisers pay the publisher only when the advertisement generates an “action” (e.g., a click-through or a purchase). This paper illustrates that adopting this emerging advertising scheme has profound impacts on one fundamental function of advertising—signaling product quality. We identify several important dimensions that affect the signaling function of performance-based advertising relative to its traditional counterpart (impression-based advertising). These include: (1) information—total advertising expenditure is determined after the demand is realized, so it is unobservable to consumers when making purchase decisions; (2) ad performance—the measured “performance” (e.g., recorded click-throughs) includes actions generated by first-time buyers (i.e., advertising performance) and actions generated by repeat buyers (i.e., product performance), which increases the cost of signaling through advertising; (3) demand uncertainty—the merchant pays only when a response to the advertisement is generated, which reduces the merchant's advertising uncertainty. We build a model of performance-based advertising by explicitly incorporating these factors, and we derive the conditions under which switching to performance-based advertising will (a) disable or strengthen the signaling function of advertising, (b) help or hurt the merchant, and (c) lead to a higher or lower advertising expenditure.
Advancing Public Trust Relationships in Electronic Government: The Singapore E-Filing Journey
Authors: Lim Eric T. K. , Tan Chee-Wee , Cyr Dianne , Pan Shan L. , Xiao Bo
Published: November 2011

E-governments have become an increasingly integral part of the virtual economic landscape. However, e-government systems have been plagued by an unsatisfactory, or even a decreasing, level of trust among citizen users. The political exclusivity and longstanding bureaucracy of governmental institutions have amplified the level of difficulty in gaining citizens' acceptance of e-government systems. Through the synthesis of trust-building processes with trust relational forms, we construct a multidimensional, integrated analytical framework to guide our investigation of how e-government systems can be structured to restore trust in citizen-government relationships. Specifically, the analytical framework identifies trust-building strategies (calculative-based, prediction-based, intentionality-based, capability-based, and transference-based trust) to be enacted for restoring public trust via e-government systems. Applying the analytical framework to the case of Singapore's Electronic Tax-Filing (E-Filing) system, we advance an e-government developmental model that yields both developmental prescriptions and technological specifications for the realization of these trust-building strategies. Further, we highlight the impact of sociopolitical climates on the speed of e-government maturity.
The Effects of Social Network Structure on Enterprise Systems Success: A Longitudinal Multilevel Analysis
Authors: Sasidharan Sharath , Santhanam Radhika , Brass Daniel J. , Sambamurthy Vallabh
Published: November 2011

The implementation of enterprise systems has yielded mixed and unpredictable outcomes in organizations. Although the focus of prior research has been on training and individual self-efficacy as important enablers, we examine the roles that the social network structures of employees, and the organizational units where they work, play in influencing the postimplementation success. Data were gathered across several units within a large organization: immediately after the implementation, six months after the implementation, and one year after the implementation. Social network analysis was used to understand the effects of network structures, and hierarchical linear modeling was used to capture the multilevel effects at unit and individual levels. At the unit level of analysis, we found that centralized structures inhibit implementation success. At the individual level of analysis, employees with high in-degree and betweenness centrality reported high task impact and information quality. We also found a cross-level effect such that central employees in centralized units reported implementation success. This suggests that individual-level success can occur even within a unit structure that is detrimental to unit-level success. Our research has significant implications for the implementation of enterprise systems in large organizations.
A comparison of methods of post-operative analgesia in children undergoing limb reconstruction with circular frames
Authors: Wells-Cole E. , Griffiths A. , Fines D. , Zenios M.
Published: November 2011

This retrospective study compared post-operative epidural analgesia (E), continuous peripheral nerve blocks (CPNB) and morphine infusion (M) in 68 children undergoing limb reconstruction with circular frames. The data collected included episodes of severe pain, post-operative duration of analgesia, requirement for top-up analgesia, number of osteotomies, side effects and complications. There was a significant difference between the number of episodes of severe pain in patients receiving a morphine infusion and those receiving epidurals or CPNB (M vs E, p < 0.0001; M vs CPNB, p = 0.018). The CPNB group was associated with the lowest incidence of episodes of severe pain and top-up analgesia. Epidural analgesia was associated with significantly more nausea and vomiting than morphine infusion (p = 0.053) and CPNB (p = 0.023). It also had a significantly higher incidence of motor blockade than CPNB (p < 0.01). We found that the most effective method of post-operative analgesia for children undergoing lower limb reconstruction was sciatic nerve catheterisation and continuous infusion.
Revision surgery following total shoulder arthroplasty
Authors: Singh J. A. , Sperling J. W. , Cofield R. H.
Published: November 2011

Our objective was to examine the rate of revision and its predictive factors in patients undergoing total shoulder arthroplasty (TSA). We used prospectively collected data from the Mayo Clinic Total Joint Registry to examine five-, ten- and 20-year revision-free survival following TSA and the predictive factors. We examined patient characteristics (age, gender, body mass index, comorbidity), implant fixation (cemented versus uncemented), American Society of Anesthesiologists class and underlying diagnosis. Univariate and multivariable adjusted hazard rates were calculated using Cox regression analysis. A total of 2207 patients underwent 2588 TSAs. Their mean age was 65.0 years (19 to 91) and 1163 (53%) were women; osteoarthritis was the underlying diagnosis in 1640 shoulders (63%). In all, 212 TSAs (8.2%) were revised during the follow-up period. At five, ten and 20 years, survival rates were 94.2% (95% confidence interval (CI) 93.2 to 95.3), 90.2% (95% CI 88.7 to 91.7) and 81.4% (95% CI 78.4 to 84.5), respectively. In multivariable analyses men had a higher hazard ratio of revision of 1.72 (95% CI 1.28 to 2.31) (p < 0.01) compared with women, and those with rotator cuff disease had a hazard ratio of 4.71 (95% CI 2.09 to 10.59) (p < 0.001) compared with patients with rheumatoid arthritis. We concluded that male gender and rotator cuff disease are independent risk factors for revision after TSA. Future studies are needed to understand the biological rationale for these differences.
Anatomy of the medial femoral circumflex artery with respect to the vascularity of the femoral head
Authors: Zlotorowicz M. , Szczodry M. , Czubak J. , Ciszek B.
Published: November 2011

We performed a series of 16 anatomical dissections on Caucasian cadaver material to determine the surgical anatomy of the medial femoral circumflex artery (MFCA) and its anastomoses. These confirmed that the femoral head receives its blood supply primarily from the MFCA via a group of posterior superior nutrient arteries and the posterior inferior nutrient artery. In terms of anastomoses that may also contribute to the blood supply, the anastomosis with the inferior gluteal artery, via the piriformis branch, is the most important. These dissections provide a base of knowledge for further radiological studies on the vascularity of the normal femoral head and its vascularity after dislocation of the hip.
Efficacy of less invasive posterior lumbar interbody fusion as revision surgery for patients with recurrent symptoms after discectomy
Authors: Lakkol S. , Bhatia C. , Taranu R. , Pollock R. , Hadgaonkar S. , Krishna M.
Published: November 2011

Recurrence of back or leg pain after discectomy is a well-recognised problem with an incidence of up to 28%. Once conservative measures have failed, several surgical options are available and have been tried with varying degrees of success. In this study, 42 patients with recurrent symptoms after discectomy underwent less invasive posterior lumbar interbody fusion (LI-PLIF). Clinical outcome was measured using the Oswestry Disability Index (ODI), Short Form 36 (SF-36) questionnaires and visual analogue scales for back (VAS-BP) and leg pain (VAS-LP). There was a statistically significant improvement in all outcome measures (p < 0.001). The debate around which procedure is the most effective for these patients remains controversial.

Our results show that LI-PLIF is as effective as any other surgical procedure. However, given that it is less invasive, we feel that it should be considered as the preferred option.
Intramedullary and total femur replacement in revision arthroplasty as a last limb-saving option
Authors: Hoell S. , Butschek S. , Gosheger G. , Dedy N. , Dieckmann R. , Henrichs M. , Daniilidis K. , Hardes J.
Published: November 2011

There has been a substantial increase in the number of hip and knee prostheses implanted in recent years, with a consequent increase in the number of revisions required. Total femur replacement (TFR) following destruction of the entire femur, usually after several previous revision operations, is a rare procedure but is the only way of avoiding amputation. Intramedullary femur replacement (IFR) with preservation of the femoral diaphysis is a modification of TFR. Between 1999 and 2010, 27 patients with non-oncological conditions underwent surgery in our department with either IFR (n = 15) or TFR (n = 12) and were included in this study retrospectively. The aim of the study was to assess the indications, complications and outcomes of IFR and TFR in revision cases. The mean follow-up period was 31.3 months (6 to 90). Complications developed in 37% of cases, 33% in the IFR group and 4% in the TFR group. Despite a trend towards a slightly better functional outcome compared with TFR, the indication for intramedullary femur replacement should be established on a very strict basis in view of the procedure’s much higher complication rate.
The long-term results of a two-stage protocol for revision of an infected total knee replacement
Authors: Macheras G. A. , Kateros K. , Galanakos S. P. , Koutsostathis S. D. , Kontou E. , Papadakis S. A.
Published: November 2011

We report the long-term results of the management of neglected chronically infected total knee replacements with a two-stage re-implantation protocol. In 18 of 34 patients (53%) a resistant organism was isolated. All cases were treated by the same surgical team in a specialist centre and had a mean follow-up of 12.1 years (10 to 14). They were evaluated clinically and radiologically using the Knee Society Score (KSS) and the American Knee Society Roentgenographic scoring system, respectively. One patient died after eight years from an unrelated cause and two were lost to follow-up. Three patients (8.8%) developed a recurrent infection for which further surgery was required. The infection was eradicated successfully in 31 patients (91.1%). There was one case of aseptic loosening after 13 years. We found a significant improvement in the KSS at final follow-up (p < 0.001).
Progressive limitation of knee flexion secondary to an accessory quinticeps femoris muscle in a child
Authors: Labbé J.-L. , Peres O. , Leclair O. , Goulon R. , Scemama P. , Jourdel F. , Duparc B.
Published: November 2011

We describe a symptomatic, progressive restriction of knee flexion due to an accessory quadriceps femoris in a nine-year-old girl. There was no history or findings of post-injection fibrosis, nor any obvious swelling of the affected quadriceps. At arthroscopy no intra-articular pathology was found. An accessory ‘quinticeps femoris’ was diagnosed by ultrasonography and MRI. Following excision of the muscle and tendon full flexion of the knee was regained and there was no recurrence of the contracture.
Simultaneous cemented and cementless total knee replacement in the same patients
Authors: Park J.-W. , Kim Y.-H.
Published: November 2011

The purpose of this prospective, randomised study was to evaluate the clinical and radiological results comparing the identical cemented or cementless NexGen total knee prostheses implanted bilaterally in the same patient. Sequential simultaneous bilateral total knee replacements were performed in 50 patients (100 knees). There were 39 women and 11 men with a mean age of 58.4 years (51 to 67) who received a cemented prosthesis in one knee and a cementless prosthesis in the other. The mean follow-up was 13.6 years (13 to 14). At final review, the mean Knee Society scores (96.2 (82 to 100) versus 97.7 (90 to 100)), the mean Western Ontario and McMaster Universities osteoarthritis index (34.5 (4 to 59) versus 35.6 (5 to 51)), the mean ranges of knee movement (124° (100° to 140°) versus 128° (110° to 140°)), mean patient satisfaction (8.1 (sd 1.9) versus 8.3 (sd 1.7)), and radiological results were similar in both groups. The rate of survival of the femoral components was 100% in both groups at 14 years. The rate of survival of the cemented tibial component was 100% and 98% in the cementless tibial component. No osteolysis was identified in either group. Our data have shown no advantage of cementless over cemented components in total knee replacement.
The effect of aspirin and low-molecular-weight heparin on venous thromboembolism after hip replacement
Authors: Jameson S. S. , Charman S. C. , Gregg P. J. , Reed M. R. , van der Meulen J. H.
Published: November 2011

We compared thromboembolic events, major haemorrhage and death after total hip replacement in patients receiving either aspirin or low-molecular-weight heparin (LMWH). We analysed data from the National Joint Registry for England and Wales linked to an administrative database of hospital admissions in the English National Health Service. A total of 108 584 patients operated on between April 2003 and September 2008 were included and followed up for 90 days. Multivariable risk modelling and propensity score matching were used to estimate odds ratios (OR) adjusted for baseline risk factors. An OR <  1 indicates that rates are lower with LMWH than with aspirin. In all, 21.1% of patients were prescribed aspirin and 78.9% LMWH. Without adjustment, we found no statistically significant differences. The rate of pulmonary embolism was 0.68% in both groups and 90-day mortality was 0.65% with aspirin and 0.61% with LMWH (OR 0.93; 95% CI 0.77 to 1.11). With risk adjustment, the difference in mortality increased (OR 0.84; 95% CI 0.69 to 1.01). With propensity score matching the mortality difference increased even further to 0.65% with aspirin and 0.51% with LMWH (OR 0.77; 95% CI 0.61 to 0.98). These results should be considered when the conflicting recommendations of existing guidelines for thromboprophylaxis after hip replacement are being addressed.
Heterotopic ossification after total ankle arthroplasty
Authors: Choi W. J. , Lee J. W.
Published: November 2011

We evaluated the incidence of heterotopic ossification following total ankle replacement to determine whether the degree of ossification was associated with the clinical outcome. We evaluated 90 ankles in 81 consecutive patients who underwent total ankle replacement, and heterotopic ossification was assessed according to proportional involvement of the ankle joint. Correlation analysis was used to investigate the association between heterotopic ossification and outcome.

No significant association was found between the formation of heterotopic ossification and the clinical outcome. The degree of heterotopic ossification in the posterior ankle joint was not significantly correlated with posterior ankle pain (p = 0.929), the American Orthopaedic Foot and Ankle Society score (p = 0.454) or range of movement (p = 0.283).

This study indicates that caution should be observed in attributing symptoms and functional limitation to the presence of heterotopic ossification in the posterior ankle joint when considering excision of heterotopic bone after total ankle replacement.
A Study of Physician Recommendations for Reversible Contraceptive Methods Using Standardized Patients
Authors: Dehlendorf Christine , Grumbach Kevin , Vittinghoff Eric , Ruskin Rachel , Steinauer Jody
Published: November 2011

CONTEXT: Health care providers may influence patients’ choice of contraceptive method, yet little is known about the recommendations they make to their patients.

METHODS: In 2007–2008, a total of 468 physicians at four family medicine and obstetrics and gynecology meetings were randomly assigned to view one of 18 videos of a patient seeking contraceptive advice; the patients were standardized for most relevant behaviors and characteristics, but differed by race and ethnicity, socioeconomic status and gynecologic history. Participants provided their demographic and practice characteristics and completed a survey about their contraceptive recommendations for the patient. Multivariate logistic regression analyses were conducted to identify associations between physician characteristics and recommendations for specific contraceptive methods.

RESULTS: The most frequently recommended methods were the pill (89%) and ring (80%), followed by the levonor‐gestrel IUD (64%), patch (56%), injectable (49%) and copper IUD (45%). Oral contraceptives were more likely to be recommended by private practice physicians than by academic physicians (odds ratio, 2.9). Recommendations for the ring were less common among family physicians and those 56 or older than among obstetrician‐gynecologists and those 35 or younger (0.6 and 0.3, respectively), and more common among physicians in private practice than among those in academia (2.4). The patch and injectable were more commonly recommended by family physicians than by obstetrician‐gynecologists (2.6 and 2.5, respectively). Both IUD types were recommended less often by physicians 36 or older than by younger ones (0.2–0.5).

DISCUSSION: The advice women receive about contraception may vary according to the characteristics of their provider. Research on the reasons for these differences is needed.