bluuebunny/crossref_metadata_2025 huggingface dataset:
A robust detail preserving anisotropic diffusion for speckle reduction in ultrasound images
Authors: Liu Xiaoming , Liu Jun , Xu Xin , Chun Lei , Tang Jinshan , Deng Youping
Published: December 2011

Background

Speckles in ultrasound imaging affect image quality and can make the post-processing difficult. Speckle reduction technologies have been employed for removing speckles for some time. One of the effective speckle reduction technologies is anisotropic diffusion. Anisotropic diffusion technology can remove the speckles effectively while preserving the edges of the image and thus has drawn great attention from image processing scientists. However, the proposed methods in the past have different disadvantages, such as being sensitive to the number of iterations or low capability of preserving the details of the ultrasound images. Thus a detail preserved anisotropic diffusion speckle reduction with less sensitive to the number of iterations is needed. This paper aims to develop this kind of technologies.

Results

In this paper, we propose a robust detail preserving anisotropic diffusion filter (RDPAD) for speckle reduction. In order to get robust diffusion, the proposed method integrates Tukey error norm function into the detail preserving anisotropic diffusion filter (DPAD) developed recently. The proposed method could prohibit over-diffusion and thus is less sensitive to the number of iterations

Conclusions

The proposed anisotropic diffusion can preserve the important structure information of the original image while reducing speckles. It is also less sensitive to the number of iterations. Experimental results on real ultrasound images show the effectiveness of the proposed anisotropic diffusion filter.
Model-based PEEP optimisation in mechanical ventilation
Authors: Chiew Yeong Shiong , Chase J Geoffrey , Shaw Geoffrey M , Sundaresan Ashwath , Desaive Thomas
Published: December 2011

Background

Acute Respiratory Distress Syndrome (ARDS) patients require mechanical ventilation (MV) for breathing support. Patient-specific PEEP is encouraged for treating different patients but there is no well established method in optimal PEEP selection.

Methods

A study of 10 patients diagnosed with ALI/ARDS whom underwent recruitment manoeuvre is carried out. Airway pressure and flow data are used to identify patient-specific constant lung elastance (E

lung
) and time-variant dynamic lung elastance (E

drs
) at each PEEP level (increments of 5cmH

2

O), for a single compartment linear lung model using integral-based methods. Optimal PEEP is estimated using E

lung
versus PEEP, E

drs
-Pressure curve and E

drs
Area at minimum elastance (maximum compliance) and the inflection of the curves (diminishing return). Results are compared to clinically selected PEEP values. The trials and use of the data were approved by the New Zealand South Island Regional Ethics Committee.

Results

Median absolute percentage fitting error to the data when estimating time-variant E

drs
is 0.9% (IQR = 0.5-2.4) and 5.6% [IQR: 1.8-11.3] when estimating constant E

lung
. Both E

lung
and E

drs
decrease with PEEP to a minimum, before rising, and indicating potential over-inflation. Median E

drs
over all patients across all PEEP values was 32.2 cmH

2

O/l [IQR: 26.1-46.6], reflecting the heterogeneity of ALI/ARDS patients, and their response to PEEP, that complicates standard approaches to PEEP selection. All E

drs
-Pressure curves have a clear inflection point before minimum E

drs
, making PEEP selection straightforward. Model-based selected PEEP using the proposed metrics were higher than clinically selected values in 7/10 cases.

Conclusion

Continuous monitoring of the patient-specific E

lung
and E

drs
and minimally invasive PEEP titration provide a unique, patient-specific and physiologically relevant metric to optimize PEEP selection with minimal disruption of MV therapy.
Education in mental health promotion and its impact on the participants' attitudes and perceived mental health
Authors: Tomaras Vlassis D , Ginieri-Coccossis Maria , Vassiliadou Maria , Malliori Melpomeni , Ferentinos Spyros , Soldatos Constantin R , Tylee Andre
Published: December 2011

Background

Although the promotion of mental health (MHP) through education and training is widely accepted, there is scarce evidence for its effectiveness in the literature from outcome studies worldwide. The present study aimed to assess the effect of a three-semester MHP educational program on the recipients' opinions towards mental illness and on their own self-assessed health.

Methods

Respondents were 78 attendees who completed the assessment battery at the first (baseline) and the last session (end) of the training course. They were primary care physicians or other professionals, or key community agents, working in the greater Athens area. The course consisted of 44 sessions (4 h each), over a 3-semester period, focusing on the principles and methods of mental health promotion, the main aspects of major psychiatric disorders, and on relevant to health skills. Assessment instruments included the Opinion about Mental Illness (OMI) scale and the General Health Questionnaire (GHQ-28).

Results

The mean scores of three OMI factors, that is, social discrimination, social restriction and social integration, and the two GHQ-28 subscales, that is, anxiety/insomnia and social dysfunction, were significantly improved by the end of the training course.

Conclusions

The results of this study provide evidence, with limitations, for the short-term effectiveness of the implemented educational MHP program on an adult group of recipients-key agents in their community. Because interventions for strengthening positive opinions about mental illness and enhancing self-assessed health constitute priority aims of mental health promotion, it would be beneficial to further investigate the sustainability of the observed positive changes. In addition it would be useful to examine (a) the possible interplay between the two outcome measures, that is, the effect of opinions of recipients about mental health on their perceived health, and (b) the applicability of this intervention in individuals with different sociodemographic profiles.
Polymerase chain reaction and histology in diagnosis of placental malaria in an area of unstable malaria transmission in Central Sudan
Authors: Elbashir Haggar M , Salih Magdi M , Elhassan Elhassan M , Mohmmed Ahmed A , Elbashir Mustafa I , Adam Ishag
Published: December 2011

Background

Prevalence of placental malaria has been widely used as a standard indicator to characterize malaria infection in epidemiologic surveys. Placental malaria poses a greater diagnostic challenge, accurate and sensitive diagnostic tool for malaria infections in pregnancy is needed.

Methods

A cross sectional study was conducted at Medani Hospital, which serves catchment area which is characterized by unstable malaria transmission. One hundred and seven placentae were investigated for malaria infection using polymerase chain reaction (PCR) and histology.

Results

out of 107 investigated placentae, 33 (30.8%) and 34 (31.8%) were positive for malaria by histology (two (2%) and 31(29.0%) were acute and past infections, respectively) and PCR, respectively. Out of 33 positive by histology, 15 were positive by the PCR while 18 were negative. The sensitivity of the PCR was 45.5% (95% CI: 29.2%- 62.5%). Out of 74 which were negative by histology, 19 were positive by the PCR. This is translated in specificity of 74.3% (95% CI: 63.5%- 83.3%). Of those tested positive by the PCR, 15 were positive by the histology, while 19 were negative. This is translated into a positive predictive value of 44.1% (95% CI: 28.3%- 61.0%). Of those 73 tested negative by the PCR, 55 were negative according to histology while 23 were positive. This is translated into a negative predictive value of 75.3% (95% CI: 64.5%-84.2%).

Conclusion

PCR had low sensitivity and specificity in comparison to placental histology, perhaps because the vast majority of the placental infections were past infections. Further research is needed.
Exploring virus relationships based on virus-host protein-protein interaction network
Authors: Xu Feng , Zhao Chen , Li Yuhua , Li Jiang , Deng Youping , Shi Tieliu
Published: December 2011

Background

Currently, several systems have been proposed to classify viruses and indicate the relationships between different ones, though each system has its limitations because of the complexity of viral origins and their rapid evolution rate. We hereby propose a new method to explore the relationships between different viruses.

Method

A new method, which is based on the virus-host protein-protein interaction network, is proposed in this paper to categorize viruses. The distances between 114 human viruses, including 48 HIV-1 and HIV-2 viruses, are estimated according to the protein-protein interaction network between these viruses and humans.

Conclusions/significance

The results demonstrated that our method can disclose not only relationships consistent with the taxonomic results of currently used systems of classification but also the potential relationships that the current virus classification systems have not revealed. Moreover, the method points to a new direction where the functional relationships between viruses and hosts can be used to explore the virus relationships on a systematic level.
A comprehensive network and pathway analysis of candidate genes in major depressive disorder
Authors: Jia Peilin , Kao Chung-Feng , Kuo Po-Hsiu , Zhao Zhongming
Published: December 2011

Background

Numerous genetic and genomic datasets related to complex diseases have been made available during the last decade. It is now a great challenge to assess such heterogeneous datasets to prioritize disease genes and perform follow up functional analysis and validation. Among complex disease studies, psychiatric disorders such as major depressive disorder (MDD) are especially in need of robust integrative analysis because these diseases are more complex than others, with weak genetic factors at various levels, including genetic markers, transcription (gene expression), epigenetics (methylation), protein, pathways and networks.

Results

In this study, we proposed a comprehensive analysis framework at the systems level and demonstrated it in MDD using a set of candidate genes that have recently been prioritized based on multiple lines of evidence including association, linkage, gene expression (both human and animal studies), regulatory pathway, and literature search. In the network analysis, we explored the topological characteristics of these genes in the context of the human interactome and compared them with two other complex diseases. The network topological features indicated that MDD is similar to schizophrenia compared to cancer. In the functional analysis, we performed the gene set enrichment analysis for both Gene Ontology categories and canonical pathways. Moreover, we proposed a unique pathway crosstalk approach to examine the dynamic interactions among biological pathways. Our pathway enrichment and crosstalk analyses revealed two unique pathway interaction modules that were significantly enriched with MDD genes. These two modules are neuro-transmission and immune system related, supporting the neuropathology hypothesis of MDD. Finally, we constructed a MDD-specific subnetwork, which recruited novel candidate genes with association signals from a major MDD GWAS dataset.

Conclusions

This study is the first systematic network and pathway analysis of candidate genes in MDD, providing abundant important information about gene interaction and regulation in a major psychiatric disease. The results suggest potential functional components underlying the molecular mechanisms of MDD and, thus, facilitate generation of novel hypotheses in this disease. The systems biology based strategy in this study can be applied to many other complex diseases.
State Space Model with hidden variables for reconstruction of gene regulatory networks
Authors: Wu Xi , Li Peng , Wang Nan , Gong Ping , Perkins Edward J , Deng Youping , Zhang Chaoyang
Published: December 2011

Background

State Space Model (SSM) is a relatively new approach to inferring gene regulatory networks. It requires less computational time than Dynamic Bayesian Networks (DBN). There are two types of variables in the linear SSM, observed variables and hidden variables. SSM uses an iterative method, namely Expectation-Maximization, to infer regulatory relationships from microarray datasets. The hidden variables cannot be directly observed from experiments. How to determine the number of hidden variables has a significant impact on the accuracy of network inference. In this study, we used SSM to infer Gene regulatory networks (GRNs) from synthetic time series datasets, investigated Bayesian Information Criterion (BIC) and Principle Component Analysis (PCA) approaches to determining the number of hidden variables in SSM, and evaluated the performance of SSM in comparison with DBN.

Method

True GRNs and synthetic gene expression datasets were generated using GeneNetWeaver. Both DBN and linear SSM were used to infer GRNs from the synthetic datasets. The inferred networks were compared with the true networks.

Results

Our results show that inference precision varied with the number of hidden variables. For some regulatory networks, the inference precision of DBN was higher but SSM performed better in other cases. Although the overall performance of the two approaches is compatible, SSM is much faster and capable of inferring much larger networks than DBN.

Conclusion

This study provides useful information in handling the hidden variables and improving the inference precision.
The Broad Street pump revisited: dairy farms and an ongoing outbreak of inflammatory bowel disease in Forest, Virginia
Authors: Pierce Ellen S , Borowitz Stephen M , Naser Saleh A
Published: December 2011

We report an ongoing outbreak of ulcerative colitis and Crohn's disease in Forest, Virginia involving 15 unrelated children and teenagers who resided in close proximity to dairy farms. Some of our cases demonstrated serologic evidence of Mycobacterium avium subspecies paratuberculosis infection, suggesting its potential role as an etiologic agent.
DNA methylation is associated with downregulation of the organic cation transporter OCT1 (SLC22A1) in human hepatocellular carcinoma
Authors: Schaeffeler Elke , Hellerbrand Claus , Nies Anne T , Winter Stefan , Kruck Stephan , Hofmann Ute , van der Kuip Heiko , Zanger Ulrich M , Koepsell Hermann , Schwab Matthias
Published: December 2011

Background

Organic cation transporters (OCTs) determine not only physiological processes but are also involved in the cellular uptake of anticancer agents. Based on microarray analyses in hepatocellular carcinoma (HCC), SLC22A1/OCT1 mRNA seems to be downregulated, but systematic protein expression data are currently missing. Moreover, the underlying molecular mechanisms responsible for altered SLC22A1 expression in HCC are not fully understood. Therefore, we investigated the role of DNA methylation in the transcriptional regulation of the family members SLC22A1/OCT1, SLC22A2/OCT2 and SLC22A3/OCT3 in HCC.

Methods

Semiquantitative immunohistochemistry of SLC22A1 protein expression was performed in paired HCC and histological normal adjacent liver tissues (n = 71) using tissue microarray analyses, and the results were correlated with clinicopathological features. DNA methylation, quantified by MALDI-TOF mass spectrometry and gene expression of SLC22A1, SLC22A2 and SLC22A3 were investigated using fresh-frozen HCC (n = 22) and non-tumor adjacent liver tissues as well as histologically normal liver samples (n = 120) from a large-scale liverbank.

Results

Based on tissue microarray analyses, we observed a significant downregulation of SLC22A1 protein expression in HCC compared to normal adjacent tissue (P < 0.0001). SLC22A1 expression was significantly inverse correlated with expression of the proliferation marker MIB1/Ki-67 (rs = -0.464, P < 0.0001). DNA methylation of SLC22A1 was significantly higher in HCC compared with non-tumor adjacent liver tissue and was lowest in histologically normal liver tissue. Methylation levels for SLC22A1 in combination with RASSF1A resulted in a specificity of > 90% and a sensitivity of 82% for discriminating HCC and tumor-free liver tissue.

Conclusions

DNA methylation of SLC22A1 is associated with downregulation of SLC22A1 in HCC and might be a new biomarker for HCC diagnosis and prognosis. Moreover, targeting SLC22A1 methylation by demethylating agents may offer a novel strategy for anticancer therapy of HCC.
Psychosis incidence through the prism of early intervention services
Authors: Kirkbride J. B. , Stubbins C. , Jones P. B.
Published: December 2011

We know little about first-episode psychosis epidemiology beyond cities or when measured through early intervention in psychosis services. We present results from 18 months of the 3-year Social Epidemiology of Psychoses in East Anglia (SEPEA) study of incepted incidence observed through five early intervention services. We identified 378 eligible individuals (incidence: 45.1/100 000 person-years, 95% CI 40.8–49.9). Rates varied across these services, but were 2–3 times higher than those on which services were commissioned. Risk decreased with age, was nearly doubled among men and differed by ethnic group; doubled in people of mixed ethnicity but lower for those of Asian origin, compared with White British people. Psychosis risk among ethnic minorities was lower than reported in urban settings, which has potential implications for aetiology. Our data suggest considerable psychosis morbidity in diverse, rural communities.
Sleep and circadian rhythm disruption in schizophrenia
Authors: Wulff Katharina , Dijk Derk-Jan , Middleton Benita , Foster Russell G. , Joyce Eileen M.
Published: December 2011

Background

Sleep disturbances comparable with insomnia occur in up to 80% of people with schizophrenia, but very little is known about the contribution of circadian coordination to these prevalent disruptions.

Aims

A systematic exploration of circadian time patterns in individuals with schizophrenia with recurrent sleep disruption.

Method

We examined the relationship between sleep–wake activity, recorded actigraphically over 6 weeks, along with ambient light exposure and simultaneous circadian clock timing, by collecting weekly 48 h profiles of a urinary metabolite of melatonin in 20 out-patients with schizophrenia and 21 healthy control individuals matched for age, gender and being unemployed.

Results

Significant sleep/circadian disruption occurred in all the participants with schizophrenia. Half these individuals showed severe circadian misalignment ranging from phase-advance/delay to non-24 h periods in sleep–wake and melatonin cycles, and the other half showed patterns from excessive sleep to highly irregular and fragmented sleep epochs but with normally timed melatonin production.

Conclusions

Severe circadian sleep/wake disruptions exist despite stability in mood, mental state and newer antipsychotic treatment. They cannot be explained by the individuals' level of everyday function.
Loss of epidermal hypoxia-inducible factor-1α accelerates epidermal aging and affects re-epithelialization in human and mouse
Authors: Rezvani Hamid Reza , Ali Nsrein , Serrano-Sanchez Martin , Dubus Pierre , Varon Christine , Ged Cécile , Pain Catherine , Cario-André Muriel , Seneschal Julien , Taïeb Alain , de Verneuil Hubert , Mazurier Frédéric
Published: December 2011

In mouse and human skin, HIF-1α is constitutively expressed in the epidermis, mainly in the basal layer. HIF-1α has been shown to have crucial systemic functions: regulation of kidney erythropoietin production in mice with constitutive HIF-1α epidermal deletion, and hypervascularity following epidermal HIF-1α overexpression. However, its local role in keratinocyte physiology has not been clearly defined. To address the function of HIF-1α in the epidermis, we used the mouse model of HIF-1α knockout targeted to keratinocytes (K14-Cre/Hif1aflox/flox). These mice had a delayed skin phenotype characterized by skin atrophy and pruritic inflammation, partly mediated by basement membrane disturbances involving laminin-332 (Ln-332) and integrins. We also investigated the relevance of results of studies in mice to human skin using reconstructed epidermis and showed that HIF-1α knockdown in human keratinocytes impairs the formation of a viable reconstructed epidermis. A diminution of keratinocyte growth potential, following HIF-1α silencing, was associated with a decreased expression of Ln-322 and α6 integrin and β1 integrin. Overall, these results indicate a role of HIF-1α in skin homeostasis especially during epidermal aging.
BubR1 blocks substrate recruitment to the APC/C in a KEN-box-dependent manner
Authors: Lara-Gonzalez Pablo , Scott Maria I. F. , Diez Maria , Sen Onur , Taylor Stephen S.
Published: December 2011

The spindle assembly checkpoint (SAC) is a signalling network that delays anaphase onset until all the chromosomes are attached to the mitotic spindle through their kinetochores. The downstream target of the spindle checkpoint is the anaphase-promoting complex/cyclosome (APC/C), an E3 ubiquitin ligase that targets several anaphase inhibitors for proteolysis, including securin and cyclin B1. In the presence of unattached kinetochores, the APC/C is inhibited by the mitotic checkpoint complex (MCC), a tetrameric complex composed of three SAC components, namely BubR1, Bub3 and Mad2, and the APC/C co-activator Cdc20. The molecular mechanisms underlying exactly how unattached kinetochores catalyse MCC formation and how the MCC then inhibits the APC/C remain obscure. Here, using RNAi complementation and in vitro ubiquitylation assays, we investigate the domains in BubR1 required for APC/C inhibition. We observe that kinetochore localisation of BubR1 is required for efficient MCC assembly and SAC response. Furthermore, in contrast to previous studies, we show that the N-terminal domain of BubR1 is the only domain involved in binding to Cdc20–Mad2 and the APC/C. Within this region, an N-terminal KEN box (KEN1) is essential for these interactions. By contrast, mutation of the second KEN box (KEN2) of BubR1 does not interfere with MCC assembly or APC/C binding. However, both in cells and in vitro, the KEN2 box is required for inhibition of APC/C when activated by Cdc20 (APC/CCdc20). Indeed, we show that this second KEN box promotes SAC function by blocking the recruitment of substrates to the APC/C. Thus, we propose a model in which the BubR1 KEN boxes play two very different roles, the first to promote MCC assembly and the second to block substrate recruitment to APC/CCdc20.
Water-Soluble Fluorinated Polymer Nanoparticle as 19F MRI Contrast Agent Prepared by Living Random Copolymerization from Dendrimer Initiator
Authors: Ogawa Michihiro , Kataoka Hiromasa , Nitahara Satoshi , Fujimoto Hiroyuki , Aoki Hiroyuki , Ito Shinzaburo , Narazaki Michiko , Matsuda Tetsuya
Published: December 2011

Water-soluble fluorinated polymer nanoparticles (PNPs) with well-defined structure were successfully prepared as a 19F MRI contrast agent by living radical copolymerization of 2,2,3,3-tetrafluoropropyl methacrylate (TFPMA) and tert-butyl methacrylate (tBMA) initiated from a dendritic macroinitiator. The obtained polymers were hydrolyzed and then converted into a sodium salt, yielding water-soluble fluorinated dendritic-star copolymers (PAMAM-g-PTFPMA-co-PMANa). The copolymer showed a sphere-like structure and the diameter increased in the range of 12–25 nm with the increase of the molecular weight. In 19F NMR properties, the T1 and T2 relaxation times were evaluated to be 400 and 70–80 ms, respectively, and were not significantly affected by the molecular weight of the copolymers. 19F MRI in vitro signals can be visualized at the lowest concentration of 0.5 mM (F atom) and detectable even at concentrations lower than 0.2 µM (particle concentration) under this experimental condition, indicating the high sensitivity due to the accumulated fluorine atoms into nanoparticle. Furthermore, in vivo MRI demonstrated the feasibility of the water-soluble fluorinated PNP as a new type of 19F MRI contrast agent.
Nanoarchitectonics for Mesoporous Materials
Authors: Ariga Katsuhiko , Vinu Ajayan , Yamauchi Yusuke , Ji Qingmin , Hill Jonathan P
Published: December 2011

Although mesoporous materials have well-defined pore structures, these fine materials can surprisingly be produced by employing a set of conventional and simple procedures such as mixing, heating, filtration, and washing, using low-cost materials. They can be regarded as easy-to-make bulk nanostructured materials. Mesoporous materials have great potential for use in both macroscopic applications and nanotechnology. In this account, we introduce examples of recent developments in mesoporous materials involving innovations in their components and structural designs and concentrating on our own recent progress. These examples include syntheses of mesoporous silica, metal oxides, semiconductive materials, metals, alloys, organic composites, biomaterial composites, carbon, carbon nitride, and boron nitride, as innovative components. As structural innovations for mesoporous materials, various film preparations, pore alignments, and hierarchic structures are described together with their related functions including sensing and controlled release of target molecules.
Lower value of glycated haemoglobin relative to glycaemic control in diabetic patients with end-stage renal disease not on haemodialysis
Authors: Shima Kenji , Chujo Keiko , Yamada Mayumi , Komatsu Machiko , Noma Yoshihiko , Mizuguchi Takashi
Published: December 2011

Background

Glycated haemoglobin (HbA1c) concentration is lower relative to glyacemic control in diabetic patients on haemodialysis. However, it is unknown as to whether this is also true for diabetic patients with end-stage renal disease but not on haemodialysis.

Methods

Correlations between HbA1c or glycated albumin (GA) and estimated glomerular filtration rate (eGFR) (determined by serum creatinine concentration, sex and age) were investigated in 86 diabetic patients with renal dysfunction not on dialysis. The mean values of HbA1c and of red blood cell (RBC) lifespan were compared among four groups of patients: Group 1 ( n = 30, eGFR ≥ 60 mL/min/1.73 m2), Group 2 ( n = 30, eGFR < 60 mL/min/1.73 m2 but ≥30 mL/min/1.73 m2), Group 3 ( n = 13, eGFR < 30 mL/min/1.73 m2 but ≥15 mL/min/1.73 m2) and Group 4 ( n = 13, eGFR < 15 mL/min/1.73 m2 without haemodialysis). RBC lifespan was determined in each subject from the difference between alveolar carbon monoxide (CO) concentration and atmospheric CO concentration.

Results

HbA1c was significantly correlated with eGFR ( r = 0.37, P = 0.0004), but GA was not. The HbA1c values in Group 3 (6.8 ± 0.6%) and Group 4 (6.3 ± 0.5%) were significantly lower than that in Group 1 (7.4 ± 0.8%), but there was no difference between Group 2 (7.2 ± 0.7%) and Group 1. There was a significant correlation between RBC lifespan and eGFR, and the mean RBC lifespan in Group 3 (96 ± 35 d) and Group 4 (94 ± 30 d) were significantly shorter than that in Group 1 (127 ± 30 d).

Conclusions

Diabetic patients with stage 4 or 5 chronic kidney disease not on haemodialysis had significantly lower values of HbA1c and shorter RBC lifespan compared with diabetic patients without renal dysfunction.
Readability and Content of Postoperative Tonsillectomy Instructions Given to Patients in Scotland, a Completed Audit Cycle
Authors: Mcallister K A , Clement W A
Published: December 2011

The aim of this study was to assess the impact of the recommendations and interventions of the 2003 audit of ‘readability and content of postoperative tonsillectomy instructions, given to patients in Scotland’. A two-cycle audit of readability and content of postoperative tonsillectomy instructions was undertaken. All National Health Service (NHS) hospital wards and associated Otolaryngology Departments in Scotland where tonsillectomies were being performed were contacted. Interventions following the first cycle included the mailing copies of original audit results and conclusions to all ear, nose and throat wards in Scotland, presentation at a National Meeting and publication of results in a peer reviewed journal. While changes had occurred in 61% of the information sheets, and with six of the 31 (19%) postoperative information sheets now being written at or below the recommended reading level, the average reading grade/age required to understand these information sheets still remains above those recommended by patient education experts. In conclusion, the majority of postoperative tonsillectomy information sheets in Scotland remain written at a level above those recommended by patient education experts. The interventions undertaken in this audit were of limited success. The ENT-UK Tonsillectomy Information sheets (2006) are written at reasonable reading levels, have good content levels and we continue to recommend these information sheets.
Walk or run? is high-intensity exercise more effective than moderate-intensity exercise at reducing cardiovascular risk?
Authors: Rankin A J , Rankin A C , Macintyre P , Hillis W S
Published: December 2011

The benefits of exercise in the prevention of cardiovascular disease are irrefutable. However, the optimum ‘dose’ of exercise in order to derive the maximum cardiovascular benefit is not certain. Current national and international guidelines advocate the benefits of moderate-intensity exercise. The relative benefits of vigorous versus moderate-intensity exercise have been studied in large epidemiological studies, addressing coronary heart disease and mortality, as well as smaller randomized clinical trials which assessed effects on cardiovascular risk factors. There is evidence that exercise intensity, rather than duration or frequency, is the most important variable in determining cardioprotection. Applying this evidence into practice must take into account the impact of baseline fitness, compliance and the independent risk associated with a sedentary lifestyle. This review aims to evaluate the role of exercise intensity in the reduction of cardiovascular risk, and answer the question: should you be advising your patients to walk or run?
Outpatient Imaging for Pulmonary Embolism May Only be Suitable for a Minority
Authors: Cameron A , Ogilvie C , Teckchandani S , Mckay G
Published: December 2011

In this study we model the impact of introducing outpatient investigation of pulmonary thromboembolism (PTE) to the acute medical unit (AMU) using the Pulmonary Embolism Severity Index (PESI) decision rule. Specifically, we ask what proportion of patients requiring imaging could be investigated without admission, and how many bed-days this would save. We obtained records for all medical patients who had imaging for PTE in a six-month period at a large teaching hospital with a 40-bedded AMU. The patients were categorized into suitability for outpatient investigation using a combination of the PESI rule and practical considerations. Three hundred and fifty-nine separate presentations were identified. From available records, 31 patients (9.2%, 95% confidence interval [CI] 6.6–12.8%) had no contraindications to outpatient management. These patients used a total of 79 bed-days in the six-month period, or 1.1% (95% CI 0.8–1.5%) of the maximum AMU bed occupancy. Around 10% of patients who require imaging for suspected PTE could be triaged to outpatient investigation using the PESI tool. Adopting this method to triage patients of ambulatory care, would have only a modest effect on acute medical bed occupancy, but remains a valid option for motivated patients in the low-risk category.
A role for transcription from a piRNA cluster in de novo piRNA production
Authors: Kawaoka Shinpei , Mitsutake Hiroshi , Kiuchi Takashi , Kobayashi Maki , Yoshikawa Mayu , Suzuki Yutaka , Sugano Sumio , Shimada Toru , Kobayashi Jun , Tomari Yukihide , Katsuma Susumu
Published: December 2011

PIWI-interacting RNAs (piRNAs) are at the heart of the nucleic acid–based adaptive immune system against transposons in animal gonads. To date, how the piRNA pathway senses an element as a substrate and how de novo piRNA production is initiated remain elusive. Here, by utilizing a GFP transgene, we screened and obtained clonal silkworm BmN4 cell lines producing massively amplified GFP-derived piRNAs capable of silencing GFP in trans. In multiple independent cell lines where GFP expression was silenced by the piRNA pathway, we detected a common transcript from an endogenous piRNA cluster, in which a part of the cluster is uniquely fused with an antisense GFP sequence. Bioinformatic analyses suggest that the fusion transcript is a source of GFP primary piRNAs. Our data implicate a role for transcription from a piRNA cluster in initiating de novo piRNA production against a new insertion.
A range of complex probabilistic models for RNA secondary structure prediction that includes the nearest-neighbor model and more
Authors: Rivas Elena , Lang Raymond , Eddy Sean R.
Published: December 2011

The standard approach for single-sequence RNA secondary structure prediction uses a nearest-neighbor thermodynamic model with several thousand experimentally determined energy parameters. An attractive alternative is to use statistical approaches with parameters estimated from growing databases of structural RNAs. Good results have been reported for discriminative statistical methods using complex nearest-neighbor models, including CONTRAfold, Simfold, and ContextFold. Little work has been reported on generative probabilistic models (stochastic context-free grammars [SCFGs]) of comparable complexity, although probabilistic models are generally easier to train and to use. To explore a range of probabilistic models of increasing complexity, and to directly compare probabilistic, thermodynamic, and discriminative approaches, we created TORNADO, a computational tool that can parse a wide spectrum of RNA grammar architectures (including the standard nearest-neighbor model and more) using a generalized super-grammar that can be parameterized with probabilities, energies, or arbitrary scores. By using TORNADO, we find that probabilistic nearest-neighbor models perform comparably to (but not significantly better than) discriminative methods. We find that complex statistical models are prone to overfitting RNA structure and that evaluations should use structurally nonhomologous training and test data sets. Overfitting has affected at least one published method (ContextFold). The most important barrier to improving statistical approaches for RNA secondary structure prediction is the lack of diversity of well-curated single-sequence RNA secondary structures in current RNA databases.
Prolonged α-amanitin treatment of cells for studying mutated polymerases causes degradation of DSIF160 and other proteins
Authors: Tsao David C. , Park Noh Jin , Nag Anita , Martinson Harold G.
Published: December 2011

A useful method for studying the function of the mammalian RNA polymerase II takes advantage of the extreme sensitivity of its largest subunit, Rpb1, to α-amanitin. Mutations of interest are introduced into an α-amanitin-resistant version of Rpb1, which is then expressed ectopically in cells. The phenotypes of these cells are then examined after inhibiting the endogenous wild-type polymerase with α-amanitin. Here, we show that cells that are enabled to grow in α-amanitin by expression of an α-amanitin-resistant Rpb1 exhibit changes in cell physiology that can lead to misleading experimental outcomes. The changes we have characterized include the accelerated degradation of some proteins, such as DSIF160, and the reduced rate of synthesis of others. In one series of experiments, we examined an α-amanitin-resistant construct, with a mutant C-terminal domain (CTD), that was unable to direct poly(A)-dependent transcription termination in cells growing in α-amanitin. The potential interpretation that the termination defect in this construct is due to the mutation in the CTD was rejected when the construct was found to be termination-competent in cells grown in the absence of α-amanitin. Instead, it appears that certain termination factors become limiting when the cells are grown in α-amanitin, presumably due to the α-amanitin-induced degradation we have characterized and/or to the inadequate transcription of certain genes by the α-amanitin-resistant Rpb1-containing polymerase.
Does the Rolodex Matter? Corporate Elite's Small World and the Effectiveness of Boards of Directors
Authors: Nguyen Bang Dang
Published: December 2011

This paper investigates the impact of social ties on the effectiveness of boards of directors. When the chief executive officer (CEO) and a number of directors belong to the same social networks, the CEO is less likely to be dismissed for poor performance. The results are robust to different measures of performance and networks, and consistent after controlling for CEO ability and connected boards' superior information. Although being ousted is costly for all CEOs—who must then devote time to finding new employment and only succeed in 62% of cases—socially connected CEOs are more likely to find new and better employment after a forced departure. Evidence from this paper suggests that close social ties between board members and CEOs impact the workings of the board of directors.

This paper was accepted by Brad Barber, Teck Ho, and Terrance Odean, special issue editors.
The Impact of Group Purchasing Organizations on Healthcare-Product Supply Chains
Authors: Hu Qiaohai (Joice) , Schwarz Leroy B. , Uhan Nelson A.
Published: December 2011

This paper examines the impact of group purchasing organizations (GPOs) on healthcare-product supply chains. The supply chain we study consists of a profit-maximizing manufacturer with a quantity-discount schedule that is nonincreasing in quantity and ensures nondecreasing revenue, a profit-maximizing GPO, a competitive source selling at a fixed unit price, and n providers (e.g., hospitals) with fixed demands for a single product. Each provider seeks to minimize its total purchasing cost (i.e., the cost of the goods plus the provider's own fixed transaction cost). Buying through the GPO offers providers possible cost reductions but may involve a membership fee. Selling through the GPO offers the manufacturer possibly higher volumes, but requires that the manufacturer pay the GPO a contract administration fee (CAF), i.e., a percentage of all revenue contracted through it. Using a game-theoretic model, we examine questions about this supply chain, including how the presence of a GPO affects the providers' total purchasing costs. We also address the controversy about whether Congress should amend the Social Security Act, which, under current law, permits CAFs. Among other things, we conclude that although CAFs affect the distribution of profits between manufacturers and GPOs, they do not affect the providers' total purchasing costs.
The Microevolution of Routines: How Problem Solving and Social Preferences Interact
Authors: Loch Christoph H. , Sengupta Kishore , Ahmad M. Ghufran
Published: December 2011

Routines are repetitive patterns of activity within a group, action patterns that help the group to solve problems and organize its way of functioning. Routines address issues of problem solving as well as issues of internal integration, such as regulating group identity, status distribution, and relationships. This study uses an experiment with three-person groups to examine how routines evolve in the interaction of problem-solving and internal integration dynamics.

In line with previous work, we find that groups do indeed develop problem-solving routines over time and use them consistently. Furthermore, group members internalize and retain routines in their individual decisions. The formation and retention of these routines is, however, affected by social comparisons. Groups that have a strong sense of group identity use their problem-solving routines more consistently. Their members also better retain the routines in their individual decisions. In contrast, we find that differentiated status within a group distorts its problem-solving routines by overweighting the influence of the high-status member. Status also interferes with the formation and retention of routines, in that groups are relatively less consistent in using them and their members show lower retention of the routine in their individual decisions. Finally, a strong relationship between two of the three members in a group (leaving the third group member out) enables the two to engage in consistent problem solving, but concomitantly, the group as a whole is less able to apply its routines consistently, and group retention of routines also suffers.
Promoting Incentives: Performance Improvement in Container Port Terminals
Authors: Saurí Sergi , Robusté Francesc
Published: December 2011

Most ports in developed countries have undergone the process of privatization. One of the often-cited drawbacks of this phenomenon is that, in the case of little competition among private operators, privatization simply represents a change from a public monopoly to a private one. This paper focuses on concessions of container terminals with market power. The aim is to define incentive mechanisms to encourage a private terminal operator and a stevedore company to reduce tariffs and increase the terminal's productivity at such a level as if they were in competition. For this purpose, the problem has been analyzed in the context of the principal-agent theory. Particularly, a moral hazard problem with hidden information has been used. The model was successfully applied to a container terminal concession. The results suggest that an improvement both in the terminal's productivity and in tariffs is possible through an annual fee that is based on an estimation of the terminal's cost and tariffs in a competitive market and is paid by the private operator to the port authority.
Addressing Passenger Risk Uncertainty for Aviation Security Screening
Authors: Lee Adrian J. , Jacobson Sheldon H.
Published: December 2011

Within the aviation security system, the preeminent objective of passenger and baggage screening is to prevent prohibited items from entering the airport terminal and getting put onboard a commercial aircraft. Because of limited budget and personnel resources, as well as constraints on the screening device capacities, only a fraction of the passengers may be screened at the highest security levels. Sequential passenger assignment policies have been formulated through dynamic programming and nonlinear control. However, both of these approaches rely on a known distribution of passenger risk. This paper presents estimation algorithms that address various levels of uncertainty in the passenger risk distribution, which can be applied to existing passenger assignment policies. Simulation results are reported to illustrate the sensitivity to variations in the unknown distribution parameter and to demonstrate that the prudent practice of overestimating the overall population risk level produces a larger number of improperly screened passengers and a lower level of security in comparison to underestimating passenger risk. The key contribution of this work is the finding that integrating online estimation of passenger risk into security screening assignment decisions increases the overall expected security and decreases the sensitivity to variations in the overall population risk level.
Serum MicroRNA Expression Profile as a Biomarker in the Diagnosis and Prognosis of Pancreatic Cancer
Authors: Liu Rui , Chen Xi , Du Yiqi , Yao Weiyan , Shen Lin , Wang Cheng , Hu Zhibin , Zhuang Rui , Ning Guang , Zhang Chunni , Yuan Yaozong , Li Zhaoshen , Zen Ke , Ba Yi , Zhang Chen-Yu
Published: December 2011

BACKGROUND

Detection of pancreatic cancer (PaC), particularly at early stages, remains a great challenge owing to lack of specific biomarkers. We sought to identify a PaC-specific serum microRNA (miRNA) expression profile and test its specificity and sensitivity as a biomarker in the diagnosis and prognosis of PaC.

METHODS

We obtained serum samples from 197 PaC cases and 158 age- and sex-matched cancer-free controls. We screened the differentially expressed serum miRNAs with Illumina sequencing by synthesis technology using pooled serum samples followed by RT-qPCR validation of a large number of samples arranged in multiple stages. We used risk score analysis to evaluate the diagnostic value of the serum miRNA profiling system. To assess the serum miRNA–based biomarker accuracy in predicting PaC, we performed additional double-blind testing in 77 PaC cases and 52 controls and diagnostic classification in 55 cases with clinically suspected PaC.

RESULTS

After the selection and validation process, 7 miRNAs displayed significantly different expression levels in PaC compared with controls. This 7 miRNA–based biomarker had high sensitivity and specificity for distinguishing various stages of PaC from cancer-free controls and also accurately discriminated PaC patients from chronic pancreatitis (CP) patients. Among the 7 miRNAs, miR-21 levels in serum were significantly associated with overall PaC survival. The diagnostic accuracy rate of the 7-miRNA profile was 83.6% in correctly classifying 55 cases with clinically suspected PaC.

CONCLUSIONS

These data demonstrate that the 7 miRNA–based biomarker can serve as a novel noninvasive approach for PaC diagnosis and prognosis.
Compressive Creep of Reinforced Polymeric Piling
Authors: Bozorg-Haddad Amir , Iskander Magued
Published: December 2011

Reinforced polymeric piling (RPP) is a sustainable piling product that is gaining attention for use instead of timber piling in coastal and waterfront applications. However, unlike conventional construction materials that have well-documented creep behavior, there is virtually no reliable data on the compressive creep behavior of RPP. RPP is composed of a recycled plastic matrix made of high density polyethylene (HDPE) that is reinforced with steel or fiber reinforced polymer rods (FRP, E-glass, or fiberglass). In this study, an accelerated test method to predict the compressive creep of both recycled HDPE and FRP is employed. The method is based on the equivalence of strain energy density (SED) between conventional constant-stress creep tests and stress-strain tests, conducted at different strain rates. Test results indicate that the tested recycled HDPE exhibited a pronounced viscoelastic or viscoplastic response, at low strains, when loaded in compression. At room temperature, SED predicts that recycled HDPE will creep about 1.1 % in 100 years when loaded at an ultimate stress of 8.3 MPa (1200 psi). FRP exhibits a small viscoelastic tendency. SED predicts that the FRP loaded in compression will creep by less than 0.5 % in 100 years when loaded at an ultimate stress of 88 MPa (12 800 psi). The stress-strain behavior of RPP depends on strain compatibility of both HDPE and FRP. Creep of RPP will depend on the percentage of FRP reinforcement in the cross section. Creep of RPP is estimated to be on the order of 0.2 % to 1.8 % in 100 years under loading and reinforcement ratios employed for this research.
Stability of Metallic Glasses: Criteria and Prediction of Ductile-Brittle Transition and Crystallization
Authors: Zaichenko S. G. , Glezer A. M. , Filippova V. P.
Published: December 2011

A close correlation between the mechanical behavior changes of metal-metalloid glasses and their relaxation spectrum heat emissions has been found. The criteria of crystallization and ductile-brittle transition for these kinds of metallic glasses (MGs) have been established. They correspond to the heat emission balance between the low- and high-temperature parts of the relaxation spectrum. The model of MGs as a system constituting an additive sum of elementary two-level transitions with continuously distributed activation energies is proposed for the analytical description of the relaxation spectrum and its parameters. The methods developed in the approximation of the model permit the determination of the current state of MG materials at an arbitrary temperature, as well as forecasting of their ductile-brittle transition and crystallization according to heat emission alterations of the relaxation spectrum.