bluuebunny/crossref_metadata_2025 huggingface dataset:
Offshore work: Oil, modularity, and the how of capitalism in Equatorial Guinea
Authors: APPEL HANNAH
Published: November 2012

Oil scholarship often focuses on oil as money, as if the industry were a mere revenue‐producing machine—a black box with predictable effects. Drawing on fieldwork in Equatorial Guinea, I take the industry as my object of analysis: infrastructures, labor regimes, forms of expertise and fantasy. Starting from a visit to an offshore rig, I explore the idea of “modularity”—mobile personnel, technologies, and legal structures that enable offshore work in Equatorial Guinea to function “just like” offshore work elsewhere. Anthropologists often characterize as naive the simplifications of modular processes, the evacuation of specificity they entail. Yet for the industry in Equatorial Guinea, this evacuation of specificity was neither mistake nor flaw. Tracing the making of modularity shows how corporations can appear removed from local entanglements and also helps to clarify the “how” of capitalism—the work required to frame heterogeneity and contingency into the profit and power found in many global capitalist projects.
Morphological characteristics of blood cells in monitor lizards: is erythrocyte size linked to actual body size?
Authors: FRÝDLOVÁ Petra , HNÍZDO Jan , CHYLÍKOVÁ Lenka , ŠIMKOVÁ Olga , CIKÁNOVÁ Veronika , VELENSKÝ Petr , FRYNTA Daniel
Published: October 2012

Blood cell morphology and count are not uniform across species. Recently, between‐species comparisons revealed that the size of red blood cells is associated with body size in some lizard taxa, and this finding was interpreted in the context of the metabolic theory. In the present study, we examined the numbers and the size of blood cells in 2 species of monitor lizards, the mangrove‐dwelling monitor (Varanus indicus) and the savannah monitor (V. exanthematicus), and we compared these traits in individuals of different body size. The results revealed that during the course of ontogeny, the size of red blood cells increases with body mass. Because the mass‐specific metabolic rate decreases with body size and the cell volume‐to‐surface ratio decreases with the cell size, changes in the erythrocyte size might be the result of oxygen transport adjustment.
Habitat use and locomotion of the François' langur (Trachypithecus francoisi) in limestone habitats of Nonggang, China
Authors: ZHOU Qihai , LUO Bang , WEI Fuwen , HUANG Chengming
Published: October 2012

We collected data on habitat use and locomotion of the François' langur (Trachypithecus francoisi) between August 2003 and July 2004 at Nonggang Nature Reserve, China. A total of 739 h of behavioral data were collected during this study. We tested 2 predictions: (1) that the langurs may have special patterns of habitat use and locomotion adaptive to the limestone habitat, and (2) the langurs may exhibit different patterns of habitat use and locomotion among different zones of limestone hill. Our results indicated that François– langurs spent more time in the low‐risk, relatively food‐poor cliff–hilltop areas. When young leaves and fruit were scarce in the dry season, the langurs increased their time in the high‐risk, food‐rich valley basin. François– langurs were semi‐terrestrial, and leaping and climbing were their main locomotor modes. These behavioral patterns are considered to be related to characteristics of topography and vegetation in limestone habitat, such as large areas of cliff and discontinuous canopy. Our results also supported Prediction 2. The langurs confined locomotion to the main canopy and frequently adopted leaping while traveling in the hillside and valley basin. While traveling in cliff–hilltop areas, they tended to stay in the lower stratus (≤5 m) or move on the ground, and walking and climbing were their dominant traveling modes.
Civilian Expertise and Civilian–Military Relations in Latin America
Authors: Weeks Gregory
Published: November 2012

Even as the era of military rule in Latin America fades well into the past, empirical and theoretical questions about civilian–military relations remain highly relevant. For the first time in the region's history, most governments have been working to manage civilian–military relations within a setting of democratic rule. This article is intended to contribute to the debate over the importance of civilian expertise in the relationship between Latin American civilians and the armed forces. Its main argument is that broader permanent defense‐related civilian positions in government contribute the most to democratic civilian–military relations, whereas nonpermanent positions are also important but transitory and do not necessarily foster long‐term democratic stability. The policy implication is that governments should focus on expanding the number of permanent civilian positions related to defense in both the executive and legislative branches.
Risk factors for surgical site infection in breast surgery
Authors: Teija‐Kaisa Aholaakko , Eija Metsälä , Marja Sihvonen , Outi Lyytikäinen
Published: November 2012

Aims and objectives

To study risks of surgical site infection in breast surgery. The objectives were to measure the association of postoperative infection with patient‐ and procedure‐related factors.

Background

The infection rate in breast surgery is expected to be low but it varies a lot. The variation is recommended to be assessed by measuring procedure‐related factors.

Design

A retrospective chart review of 982 breast surgery patients was completed.

Methods

The data on patient demographics, procedure types, patient and surgery‐related factors were collected. A multivariate logistic regression model for all breast operations (n = 982), lumpectomies (n = 700) and mastectomies (n = 282) was performed.

Results

The infection rate was 6·7%. In a multivariate logistic regression model for all operations, a contaminated or dirty wound, high American Society of Anesthesiologists score, high body mass index, use of surgical drains and re‐operation predicted increased infection risk. In lumpectomies high body mass index and use of surgical drains predicted increased risk. In mastectomies, the significant predictor was re‐operation.

Conclusions

The surgical site infection rate was high. In addition to the two classical risks (high wound class and anaesthesia risk), high body mass index, re‐operation and use of surgical drain increased the infection risk among all patients.

Relevance to clinical practice

In breast surgery careful assessment, documentation and adherence to aseptic practices are important with all patients. Patients with heavy weight need special attention. The need for antimicrobial prophylaxis in re‐operations and the need of surgical drains in lumpectomies are important to consider carefully.
Involvement of the apelin receptor APJ in Fas‐induced liver injury
Authors: Yasuzaki Hiroaki , Yoshida Shin‐ichirou , Hashimoto Tatsuo , Shibata Wataru , Inamori Masahiko , Toya Yoshiyuki , Tamura Kouichi , Maeda Shin , Umemura Satoshi
Published: November 2012

Background

Apelin‐APJ signalling is known to play important roles in heart physiology and pathology; however, its functions in liver physiology and pathology remain unclear. On the other hand, Fas is an important molecule in hepatitis and other liver disease that belongs to the death receptor family. The aim of this study was to assess the relationship between apelin‐APJ signaling and Fas‐mediated liver injury in mice.

Methods

APJ−/− mice and wild type (WT) mice were administered an intraperitoneal injection of an agonistic anti‐Fas antibody (clone; Jo2), and sacrificed after 3 or 6 h to assess the liver histology. The expression levels of apelin and APJ, plasma levels of transaminases, activities of hepatic caspases and activations of stress‐activated protein kinases were also analysed.

Results

Before the Jo2 injection, APJ was weakly expressed in the hepatocytes in spots; on the other hand, after the Jo2 injection, it had spread into whole hepatocytes. Moreover, the mRNA expression level of apelin and APJ in the liver increased after Jo2 injection. In the APJ−/− mice, the liver injuries and apoptotic changes were significantly inhibited as compared with those in the WT mice. Dramatic increase in JNK activation was observed in the WT mice after Jo2 injection, whereas such activation was completely absent in the APJ−/− mice. JNK inhibitor partially, but significantly suppressed Jo2‐mediated liver injury in WT mice.

Conclusion

Apelin‐APJ signalling may promote Fas‐induced liver injury at least partially via JNK activation, and may thus serve as a potential therapeutic target in cases of acute liver injury.
Effect of Sacral Neuromodulation Rate on Overactive Bladder Symptoms: A Randomized Crossover Feasibility Study
Authors: PETERS Kenneth M. , SHEN Lijuan , MCGUIRE Maureen
Published: October 2012

Objectives: This was a single‐center, institutional review board‐approved study, conducted in the USA that used a 3 × 3 orthogonal Latin squares crossover design to assess variability in overactive bladder symptoms and adverse events when subjects were exposed to three rate settings of sacral neuromodulation.

Methods: Thirteen female subjects who had urgency frequency and urinary urge incontinence were enrolled into the study. Twelve subjects completed the study. Upon enrollment, each subject was randomized to one of three rate‐setting sequences: 5.2, 14, and 25 Hz. Each rate setting was tested for 1 week in every subject.

Results: When subjects were programmed to 5.2, 14, and 25 Hz, they had an average of 3.83 ± 2.27, 2.37 ± 1.83, and 2.82 ± 2.1 incontinence episodes per day and an average of 2.61 ± 1.64, 1.84 ± 1.43, and 1.94 ± 1.61 pad changes per day, respectively. Rate had a statistically significant effect on the number of incontinent episodes (P < 0.001) and number of pad changes (P = 0.039) with more incontinent episodes in the 5.2‐Hz setting compared to the 14‐ and 25‐Hz settings (P < 0.04) for both measurements. Nine subjects reported 21 adverse events. None of the adverse events was considered either a serious or an unanticipated adverse device effect (UADE).

Conclusion: Rate significantly affected the number of incontinence episodes and pad changes per day. The number of adverse events was similar across the three rate settings with programming‐related adverse events lowest in the 14 Hz group.
Treatment of Vaginal Cuff Prolapses with Posterior Intravaginal Sling and Evaluation of Efficiency with International Consultation on Incontinence Questionnaire—Vaginal Symptoms Method in the Long Term: Preliminary Results
Authors: BALSAK Deniz , UYSAL Ahmet , CAVUS Yunus , INCE Zehra , ACAR Zuat , GÜNGÖR Ayşenur , HACIVELİOĞLU Servet
Published: October 2012

Objectives: The aim of this study was to research the efficiency of posterior intravaginal sling (PIVS) procedure in vaginal cuff prolapse, together with possible complications, long‐term effects and effects of the method on vaginal and sexual function and quality of life of patients. This retrospective study comprised 21 patients with vaginal cuff prolapse.

Methods: PIVS procedure was performed in 21 patients with vaginal cuff prolapse with quantification stages 2, 3, or 4 of pelvic organ prolapse. Patients were assessed according to the International Consultation on Incontinence Questionnaire—Vaginal Symptoms before and after operation.

Results: The average follow‐up period was 24.6 months. The rate of surgical success was 100%, the rate of mesh erosion was 14.2% and the rate of dyspareunia was 33.3%. Vaginal symptom, sexual matter and quality of life scores were statistically significant in the postoperative period compared to the preoperative period (P = 0.001, P = 0.001, P = 0.001, respectively).

Conclusion: PIVS is an effective and reliable method of treating vaginal cuff prolapse. However, its complication profile is not yet at an acceptable level. We believe that the rate of mesh erosion will regress to a more acceptable level with the improvement of mesh technology and postoperative method. The necessary incontinence surgery is easily performed together with PIVS procedure. PIVS restores the vaginal and sexual functions of patients and increases their quality of life significantly.
Alpha‐amylase is a human salivary protein with affinity to lipopolysaccharide of Aggregatibacter actinomycetemcomitans
Authors: Baik J.E. , Hong S.W. , Choi S. , Jeon J.H. , Park O.‐J. , Cho K. , Seo D.‐G. , Kum K.‐Y. , Yun C.‐H. , Han S.H.
Published: October 2012

Aggregatibacter actinomycetemcomitans lipopolysaccharide (Aa.LPS) is a major virulence factor associated with aggressive periodontitis. Although the recognition of Aa.LPS is potentially initiated by salivary proteins in the oral cavity, Aa.LPS‐binding proteins (Aa.LPS‐BPs) in saliva are poorly characterized. The purpose of this study was to capture and identify Aa.LPS‐BPs in human saliva using a LTQ‐Orbitrap hybrid Fourier transform mass spectrometry. Aa.LPS conjugated onto N‐hydroxysuccinimidyl‐Sepharose® 4 Fast Flow beads (Aa.LPS‐beads) activated Toll‐like receptor 4 and produced nitric oxide and Interferon gamma‐inducible protein‐10, implying that the conjugation process did not alter the biological properties of Aa.LPS. Aa.LPS‐BPs were subsequently isolated from the nine human saliva samples from healthy individuals with the Aa.LPS‐beads followed by identification with the mass spectrometry. Aa.LPS‐BPs include α‐amylase, serum albumin, cystatin, lysozyme C, submaxillary gland androgen‐regulated protein 3B, immunoglobulin subunits, polymeric immunoglobulin receptor, deleted in malignant brain tumors 1, prolactin‐inducible protein, lipocalin‐1, and basic salivary proline‐rich protein 2. Specific binding was validated using a pull‐down assay with α‐amylase which was captured at the highest frequency. Alpha‐amylase demonstrated to interfere with the adherence and biofilm formation of A. actinomycetemcomitans. Even heat‐inactivated α‐amylase showed the interference to the same extent. Conclusively, we identified unique Aa.LPS‐BPs that provide useful information to understand bacterial pathogenesis and host innate immunity in the oral cavity.
Comparison of health‐related quality of life between patients with chronic obstructive pulmonary disease and the general population
Authors: Bentsen Signe Berit , Rokne Berit , Wahl Astrid Klopstad
Published: November 2012

Background

Chronic obstructive pulmonary disease (COPD) is associated with lower health‐related quality of life (HRQOL). Previous research has focused primarily on HRQOL in these patients, whereas few studies have compared HRQOL between patients with COPD and the general population.

Aim

The aim of this study was to evaluate differences in HRQOL between patients with COPD stage 2 to COPD stage 4 waiting to begin an outpatient pulmonary rehabilitation (PR) programme and Norwegian individuals with and without other chronic conditions.

Methods

A comparative survey design was used in this study of 100 patients with COPD waiting to begin PR and 3594 individuals from the general population. The SF‐36 questionnaire was used to evaluate HRQOL.

Results

Compared with the healthy general population, COPD patients waiting to begin PR had lower scores on all SF‐36 components and on the physical and mental health summary components (p < 0.001). Scores for physical function, physical role, general health, vitality, social function, emotional role and the physical health component differed markedly between patients and the general population. Patients with COPD stage 4 had lower HRQOL than did the general population and those with COPD stage 2 and COPD stage 3.

Conclusions

The burden of COPD significantly affects HRQOL in patients with COPD waiting to begin PR, and those with COPD stage 4 are most affected. Action should be taken to support especially those patients with COPD stage 4.
Weight loss in overwintering below‐ground parts of Sonchus arvensis under current and temperature‐elevated climate scenarios in Sweden
Authors: VERWIJST T , ECKERSTEN H , ANBARI S , LUNDKVIST A , TORSSELL B
Published: November 2012

Weight loss in overwintering below‐ground parts of perennial weeds has been attributed to respiration, but neither its temperature dependence nor its relevance for biomass dynamics under changing climate conditions have been investigated. In two experiments, we quantified weight loss of the perennial weed Sonchus arvensis, by measuring weight changes over time of sprouting roots in dark rooms at temperatures of 4, 8 and 18°C. Dry weight loss rates were 0.47, 0.64 and 1.47% day−1 at 4, 8 and 18°C, respectively, giving a half‐life time of 149, 110 and 47 days, respectively. A factor by which weight loss rates increase for every 10° rise in temperature (Q10) was equal to about 2.3. Cumulative weight loss may comprise >40% of the below‐ground biomass during overwintering periods. Applying weight loss rates and Q10 to elevated soil temperature projections showed that losses during winter seasons in central Sweden will remain basically constant, the effect of increased weight loss at higher temperatures being balanced by shorter winters. This implies that need for control of S. arvensis in a changing climate will persist, but that shorter winter seasons will provide a longer time window for control of S. arvensis prior to sowing crops.
Transition Modeling for Vortex Generating Jets on Low-Pressure Turbine Profiles
Authors: Herbst Florian , Kožulović Dragan , Seume Joerg R.
Published: October 2012

Steady blowing vortex generating jets (VGJ) on highly-loaded low-pressure turbine profiles have shown to be a promising way to decrease total pressure losses at low Reynolds-numbers by reducing laminar separation. In the present paper, the state of the art turbomachinery design code TRACE with RANS turbulence closure and coupled γ-ReΘ transition model is applied to the prediction of typical aerodynamic design parameters of various VGJ configurations in steady simulations. High-speed cascade wind tunnel experiments for a wide range of Reynolds-numbers, two VGJ positions, and three jet blowing ratios are used for validation. Since the original transition model overpredicts separation and losses at Re2is≤100·103, an extra mode for VGJ induced transition is introduced. Whereas the criterion for transition is modeled by a filtered Q vortex criterion the transition development itself is modeled by a reduction of the local transition-onset momentum-thickness Reynolds number. The new model significantly improves the quality of the computational results by capturing the corresponding local transition process in a physically reasonable way. This is shown to yield an improved quantitative prediction of surface pressure distributions and total pressure losses.
Optimal Application of Riblets on Compressor Blades and Their Contamination Behavior
Authors: Lietmeyer Christoph , Oehlert Karsten , Seume Joerg R.
Published: October 2012

During the last decades, riblets have shown a potential for viscous drag reduction in turbulent boundary layers. Several investigations and measurements of skin-friction in the boundary layer over flat plates and on turbomachinery-type blades with ideal riblet geometry have been reported in the literature. The question of where riblets must be applied on the surface of a compressor blade is still not sufficiently answered. In a first step, the profile loss reduction by ideal triangular riblets with a trapezoidal groove and a constant geometry along the surface on the suction and pressure sides of a compressor blade is investigated. The results show a higher potential on the profile loss reduction by riblets on the suction side. In a second step, the effect of laser-structured ribs on the laminar separation bubble and the influence of these structures on the laminar boundary layer near the leading edge are investigated. After clarifying the best choices where riblets should be applied on the blade surface, a strategy for locally adapted riblets is presented. The suction side of a compressor blade is laser-structured with segmented riblets with a constant geometry in each segment. The measured profile loss reduction shows the increasing effect on the profile loss reduction of this locally adapted structure compared to a constant riblet-geometry along the surface. Furthermore, the particle deposition on a riblet-structured compressor blade is investigated and compared to the particle deposition on a smooth surface. Results show a primary particle deposition on the riblet tips followed by an agglomeration. The particle deposition on the smooth surface is stochastic.
Film Cooling on Highly Loaded Blades With Main Flow Separation—Part II: Overall Film Cooling Effectiveness
Authors: Gomes Reinaldo A. , Niehuis Reinhard
Published: October 2012

Film cooling experiments were run at the high speed cascade wind tunnel of the University of the Federal Armed Forces Munich. The investigations were carried out with a linear cascade of highly loaded turbine blades. The main targets of the tests were to assess the film cooling effectiveness and the heat transfer in zones with main flow separation. Therefore the blades were designed to force the flow to detach on the pressure side shortly downstream of the leading edge and it reattaches at about half of the axial chord. In this zone, film cooling rows are placed among others for reduction of the size of the separation bubble. The analyzed region on the blade is critical due to the high heat transfer present at the leading edge and at the reattachment line after main flow separation. Film cooling can contribute to a reduction of the size of the separation bubble reducing aerodynamic losses but increases in general heat transfer due to turbulent mixing. The reduction of the size of the separation bubble might also be two-fold since it acts like a thermal insulator on the blade and reducing the size of the bubble might lead to stronger heating of the blade. Film cooling should therefore take into account both: firstly, a proper protection of the surface, and secondly, reduce aerodynamic losses diminishing the extension of the main flow separation. The overall effectiveness of film cooling for a real engine has to combine heat transfer with film cooling effect. In this paper, the overall effectiveness of film cooling, combining results from measurements of the adiabatic film cooling effectiveness and the local heat transfer coefficient are shown. The tests comprise the analysis of the effect of different outlet Mach and Reynolds numbers at engine relevant values and film cooling ratio. A new parameter is introduced which allows for the evaluation of the effect of film cooling accounting at the same time for the change of local heat transfer coefficient. To the authors’ opinion this parameter allows a better, physically based assessment than the strategy using the so-called heat flux ratio. A parameter study is carried out in order to benchmark the effect of changes of the blade design.
Evaluation of Heat Transfer Effects on Turbocharger Performance
Authors: Sirakov Borislav , Casey Michael
Published: November 2012

Test data on several small turbochargers with different levels of heat transfer from the turbine to the compressor have been obtained through cooling of the turbocharger center housing and by testing in hot and cold test stands. This data identifies the strong effect of the heat transfer on the apparent efficiency of the compressor and turbine, particularly at low speeds and low mass flows. A simplified theory is used to explain the apparent effect of the heat transfer on the work input and efficiency. The results confirm that conventional performance maps underestimate the efficiency of the compressor stage and overestimate the efficiency of the turbine by as much as 20% points at low speeds. A correction procedure for this effect is defined which converts performance maps obtained with heat transfer to performance maps for adiabatic conditions (for both compressor and turbine) without any prior knowledge or measurement of the heat transfer. The practical significance of the results with regard to turbocharger performance and the relevance to a broader class of turbomachines is discussed.
Time-Dependent Deposition Characteristics of Fine Coal Fly Ash in a Laboratory Gas Turbine Environment
Authors: Laycock Robert G. , Fletcher Thomas H.
Published: November 2012

Time-dependent deposition characteristics of fine coal fly ash were measured in the Turbine Accelerated Deposition Facility (TADF) at Brigham Young University. Two samples of subbituminous coal fly ash, with mass mean diameters of 3 μm and 13 μm, were entrained in a hot gas flow with a gas temperature of 1288 °C and Mach number of 0.25. A nickel-based, superalloy metal coupon approximately 0.3 cm thick was held in a hot particle-laden gas stream to simulate deposition in a gas turbine. Tests were conducted with deposition times of 20, 40, and 60 min. Capture efficiencies and surface roughness characteristics (e.g., Ra) were obtained at different times. Capture efficiency increased exponentially with time, while Ra increased linearly with time. The increased deposition with time caused the surface temperature of the deposit to increase. The increased surface temperature caused more softening, increasing the propensity for impacting particles to stick to the surface. These data are important for improving models of deposition in turbines from syngas flows.
Effect of the amido Ti precursors on the atomic layer deposition of TiN with NH3
Authors: Cho Gihee , Rhee Shi-Woo
Published: November 2012

The effect of the amide Ti precursors, tetrakis dimethyl amido titanium (TDMAT), tetrakis ethylmethyl amido titanium (TEMAT), and tetrakis diethyl amido titanium (TDEAT) on the atomic layer deposition of TiN film with ammonia was studied. Surface decomposition mechanism of each precursor was studied with in-situ Fourier transform infrared spectroscopy. It was confirmed that ethyl ligand in the precursor was more stable than methyl and the surface decomposition temperature of TDMAT, TEMAT, and TDEAT was 175, 200, and 250 °C on the SiO2 surface, respectively. The resistivity of the film was decreased with the increase in the substrate temperature due to the film crystallization. The TiN film deposited with TDMAT gave the lowest resistivity even though the atomic layer deposition temperature window was lowest due to the largest amount of carbon incorporation. It was confirmed that carbon incorporation leads to TiC formation and suppressed the postdeposition oxygen uptake possibly due to the elimination of vacancy in the film.
Bidirectional local distance measure for comparing segmentations
Authors: Kim Hak Soo , Park Samuel B. , Lo Simon S. , Monroe James I. , Sohn Jason W.
Published: October 2012

Purpose:

To accurately quantify the local difference between two contour surfaces in two‐ or three‐dimensional space, a new, robust point‐to‐surface distance measure is developed.

Methods:

To evaluate and visualize the local surface differences, point‐to‐surface distance measures have been utilized. However, previously well‐known point‐to‐surface distance measures have critical shortfalls. Previous distance measures termed “normal distance (ND),” “radial distance,” or “minimum distance (MD)” can report erroneous results at certain points where the surfaces under comparison meet certain conditions. These skewed results are due to the monodirectional characteristics of these methods. ComGrad distance was also proposed to overcome asymmetric characteristics of previous point‐to‐surface distance measures, but their critical incapability of dealing with a fold or concave contours. In this regard, a new distance measure termed the bidirectional local distance (BLD) is proposed which minimizes errors of the previous methods by taking into account the bidirectional characteristics with the forward and backward directions. BLD measure works through three steps which calculate the maximum value between the forward minimum distance (FMinD) and the backward maximum distance (BMaxD) at each point. The first step calculates the FMinD as the minimum distance to the test surface from a point,pref on the reference surface. The second step involves calculating the minimum distances at every point on the test surface to the reference surface. During the last step, the BMaxD is calculated as the maximum distance among the minimum distances found at pref on the reference surface. Tests are performed on two‐ and three‐dimensional artificial contour sets in comparison to MD and ND measure techniques. Three‐dimensional tests performed on actual liver and head‐and‐neck cancer patients.

Results:

The proposed BLD measure provides local distances between segmentations, even in situations where ND, MD, or ComGrad measures fail. In particular, the standard deviation measure is not distorted at certain geometries where ND, MD, and ComGrad measures report skewed results.

Conclusions:

The proposed measure provides more reliable statistics on contour comparisons. From the statistics, specific local and global distances can be extracted. Bidirectional local distance is a reliable distance measure in comparing two‐ or three‐dimensional organ segmentations.
An image‐based technique to assess the perceptual quality of clinical chest radiographs
Authors: Lin Yuan , Luo Hui , Dobbins James T. , Page McAdams H. , Wang Xiaohui , Sehnert William J. , Barski Lori , Foos David H. , Samei Ehsan
Published: November 2012

Purpose:

Current clinical image quality assessment techniques mainly analyze image quality for the imaging system in terms of factors such as the capture system modulation transfer function, noise power spectrum, detective quantum efficiency, and the exposure technique. While these elements form the basic underlying components of image quality, when assessing a clinical image, radiologists seldom refer to these factors, but rather examine several specific regions of the displayed patient images, further impacted by a particular image processing method applied, to see whether the image is suitable for diagnosis. In this paper, the authors developed a novel strategy to simulate radiologists’ perceptual evaluation process on actual clinical chest images.

Methods:

Ten regional based perceptual attributes of chest radiographs were determined through an observer study. Those included lung grey level, lung detail, lung noise, rib‐lung contrast, rib sharpness, mediastinum detail, mediastinum noise, mediastinum alignment, subdiaphragm‐lung contrast, and subdiaphragm area. Each attribute was characterized in terms of a physical quantity measured from the image algorithmically using an automated process. A pilot observer study was performed on 333 digital chest radiographs, which included 179 PA images with 10:1 ratio grids (set 1) and 154 AP images without grids (set 2), to ascertain the correlation between image perceptual attributes and physical quantitative measurements. To determine the acceptable range of each perceptual attribute, a preliminary quality consistency range was defined based on the preferred 80% of images in set 1. Mean value difference (μ1 − μ2) and variance ratio () were investigated to further quantify the differences between the selected two image sets.

Results:

The pilot observer study demonstrated that our regional based physical quantity metrics of chest radiographs correlated very well with their corresponding perceptual attributes. The distribution comparisons, mean value difference estimations, and variance ratio estimations of each physical quantity between sets of images from two different techniques matched our expectation that the image quality of set 1 should be better than that of set 2.

Conclusions:

The measured physical quantities provide a robust reflection of perceptual image quality in clinical images. The methodology can be readily applied for automated evaluation of perceptual image quality in clinical chest radiographs.
Brain necrosis after fractionated radiation therapy: Is the halftime for repair longer than we thought?
Authors: Bender Edward T.
Published: November 2012

Purpose:

To derive a radiobiological model that enables the estimation of brain necrosis and spinal cord myelopathy rates for a variety of fractionation schemes, and to compare repair effects between brain and spinal cord.

Methods:

Sigmoidal dose response relationships for brain radiation necrosis and spinal cord myelopathy are derived from clinical data using nonlinear regression. Three different repair models are considered and the repair halftimes are included as regression parameters.

Results:

For radiation necrosis, a repair halftime of 38.1 (range 6.9–76) h is found with monoexponential repair, while for spinal cord myelopathy, a repair halftime of 4.1 (range 0–8) h is found. The best‐fit alpha beta ratio is 0.96 (range 0.24–1.73)

Conclusions:

A radiobiological model that includes repair corrections can describe the clinical data for a variety of fraction sizes, fractionation schedules, and total doses. Modeling suggests a relatively long repair halftime for brain necrosis. This study suggests that the repair halftime for late radiation effects in the brain may be longer than is currently thought. If confirmed in future studies, this may lead to a re‐evaluation of radiation fractionation schedules for some CNS diseases, particularly for those diseases where fractionated stereotactic radiation therapy is used.
Intravital Microscopy Through an Abdominal Imaging Window Reveals a Pre-Micrometastasis Stage During Liver Metastasis
Authors: Ritsma Laila , Steller Ernst J. A. , Beerling Evelyne , Loomans Cindy J. M. , Zomer Anoek , Gerlach Carmen , Vrisekoop Nienke , Seinstra Daniëlle , van Gurp Leon , Schäfer Ronny , Raats Daniëlle A. , de Graaff Anko , Schumacher Ton N. , de Koning Eelco J. P. , Rinkes Inne H. Borel , Kranenburg Onno , Rheenen Jacco van
Published: October 2012

An abdominal imaging window allows in vivo visualization of dynamic cellular processes, including liver metastasis and islet cell transplantation.
Immune Parameters Correlate with Protection Against Ebola Virus Infection in Rodents and Nonhuman Primates
Authors: Wong Gary , Richardson Jason S. , Pillet Stéphane , Patel Ami , Qiu Xiangguo , Alimonti Judie , Hogan Jeff , Zhang Yi , Takada Ayato , Feldmann Heinz , Kobinger Gary P.
Published: October 2012

Levels of specific antibodies induced by vaccination correlate with survival in Ebola-infected animals.
Back to the Future: The Mental Time Machine
Authors: Singh Manpreet K.
Published: October 2012

The areas of the brain used for memory and imagination in children are functionally connected while the brain is at rest.
Back to the Future for Dermatophyte Genomics
Authors: Rivera Zeyana S. , Losada Liliana , Nierman William C.
Published: October 2012

Dermatophytes are a uniquely pathogenic group of fungi that cause most common fungal infections globally. The major cause of athlete’s foot is
Trichophyton rubrum
, a pathogen of human skin. A recent paper in this journal reported the sequencing and analysis of five additional genome sequences, including that of
Trichophyton rubrum
. These five join the existing two additional genome sequences to bring the total to seven dermatophyte genome sequences, a notable milestone in the study of these fungi. These additional genomes set the stage for future genome-supported studies on the biology, pathogenicity, and host specificity of this important group of pathogens. To predict how this future might play out, we review the history of
Aspergillus
genomics since the initial publication of the first three
Aspergillus
genome sequences in 2005, an event that stimulated important studies of the pathogenic
Aspergillus
species. From these 7 years of
Aspergillus
history, we offer some speculation on the future of dermatophyte studies supported by the genome sequences given the similarities, differences, and relative levels of support for studies in these two groups of fungi and the diseases they cause.
Long-Term Changes of Diffusion Tensor Imaging and Behavioural Status after Acupuncture Treatment in Rats with Transient Focal Cerebral Ischaemia
Authors: Wu Zhiyuan , Hu Jinqing , Du Fang , Zhou Xiaoyan , Xiang Qiongyao , Miao Fei
Published: October 2012

Background

The effect of acupuncture treatment in cerebral ischaemia is controversial. A study was undertaken to assess its effects in rats with transient middle cerebral artery occlusion (tMCAO) and discuss its mechanisms.

Methods

21 Sprague–Dawley rats were divided into three groups. Group 1 underwent tMCAO and subsequently received acupuncture treatment, Group 2 underwent tMCAO without treatment and Group 3 only underwent sham operation. The evolution of diffusion tensor imaging (DTI) features in ischaemic lesions from acute to chronic periods was assessed and the correlations with behavioural tests and histopathological changes were examined.

Results

tMCAO rats displayed side-specific sensorimotor deficits after occlusion. Behavioural scores of rats in group 1 reduced gradually with acupuncture treatment. No significant difference in lesion size on T2-weighted imaging was found between the two tMCAO groups. Relative apparent diffusion coefficient (rADC) and relative fractional anisotropy (rFA) values in the centre and at the edge of the ischaemic lesions reduced at first and then increased to varying degrees. Only changes in the rFA value at the edge of the ischaemic lesions were significantly different between the two tMCAO groups. A more significant increase in growth-associated protein B-50 and synaptophysin protein expression was found in group 1 than in the other groups. No significant correlations were found between behavioural scores, DTI appearances and immunohistochemical results.

Conclusions

The acupuncture points applied were effective, and improving neuronal regeneration may have a role in the mechanism of acupuncture treatment of post-stroke paralysis of the limbs in rats. MRI, particularly the fractional anisotropy value of DTI, is an appropriate parameter to evaluate the recovery status.
Emergence of pneumococcal 19A empyema in UK children
Authors: Thomas Matthew F , Sheppard Carmen L , Guiver Malcolm , Slack Mary P E , George Robert C , Gorton Russell , Paton James Y , Simmister Clare , Cliff David , Elemraid Mohamed A , Clark Julia E , Rushton Stephen P , Spencer David Anthony
Published: October 2012

Introduction

Invasive pneumococcal disease due to serotype 19A has become a major concern, particularly in the USA and Asia. We describe the characteristics of pneumococcal serotype 19A related empyema and changes in its incidence in the UK.

Methods

Data from paediatric empyema patients between September 2006 and March 2011 were collected from 17 respiratory centres in the UK. Pneumococcal serotypes were identified as part of the Health Protection Agency enhanced paediatric empyema surveillance programme.

Results

Four serotypes accounted for over 80% of 136 cases (Serotype 1 : 43%, 3 : 21%, 7 : 11% and 19A:10%). The incidence of empyema due to serotype 19A quadrupled from 0.48 (0.16–1.13) cases per million children in 2006/2007 to 2.02 (1.25–3.09) in 2010/2011. Severity of disease was significantly increased in children with 19A infection when compared to other serotypes.

Conclusions

The incidence of empyema due to pneumococcal serotype 19A infection has increased significantly and is associated with substantial morbidity.
Thirty-years of screening for cystic fibrosis in East Anglia
Authors: Calvin Jacqui , Hogg Sarah L , McShane Donna , McAuley Sharon Anne , Iles Richard , Ross-Russell Robert , MacLean Fiona M , Heeley Mary E , Heeley Anthony F
Published: October 2012

Background

Newborn screening for cystic fibrosis (CF) relies on the measurement of immunoreactive trypsinogen (IRT) originating from the pancreas. The Norfolk, Suffolk and Cambridgeshire screening programme initially exploited the persistent increase in IRT seen in CF (IRT-IRT protocol) and later changed to include mutation analysis as a second tier test (IRT-DNA-IRT protocol).

Results

During a 30 year period 582 966 babies have been screened by IRT-IRT and 147 764 by IRT-DNA-IRT (total 730730), resulting in 296 screen positive cases of CF and 29 false negatives (including 10 false negatives with meconium ileus). Ten missed CF cases were pancreatic insufficient, however all were diagnosed before their first birthday, suggesting that a false negative result did not forestall appropriate clinical investigation. The IRT-DNA-IRT protocol had a much improved positive predictive value (PPV) of 85.9% compared to 67.3% for IRT-IRT, excluding CF babies with meconium ileus. The PPVs increased to 82.2% and 98.2% respectively if only well, term babies were considered. The main factor to account for this improvement in PPV has probably been the incorporation of DNA analysis in the second tier testing.

Conclusions

The diagnosis of screen-positive babies proved difficult in a minority of cases with the classification of some patients changing with evolving phenotype. Our results illustrate the importance of collecting outcome data over a long time period for accurate assessment of the screening programme. This study provides evidence that newborn screening for CF is a valid undertaking that detects 95% of unsuspected CF cases presenting before 3 years of age.
Management of paediatric head injury in remote Nepal
Authors: Mallinson Tom
Published: October 2012

Soo Jung Hospital in Doti, Far-Western Nepal is a small district hospital founded in 1994 and run as a private hospital with support from charity donations. It is staffed by two doctors, and two health assistants, supported by a team of nurses and nursing students. Approximately 50 people are seen as outpatients each day. There is a four bed emergency department and two inpatient wards which are able to accommodate 16 patients between them. Basic x-ray facilities are available, but for further imagining studies and surgical interventions patients must be referred to a tertiary centre, the nearest being 7–9 h away by road. Cases of major trauma must be managed with these limited facilities for prolonged periods of time. In addition to this, once a decision has been made to attempt an interhospital transfer, this is undertaken in a vehicle ill-equipped, or staffed, to perform medical interventions en route.
Cost-effectiveness of a European preventive cardiology programme in primary care: a Markov modelling approach
Authors: Mistry Hema , Morris Stephen , Dyer Matthew , Kotseva Kornelia , Wood David , Buxton Martin
Published: October 2012

Objective

To investigate the longer-term cost-effectiveness of a nurse-coordinated preventive cardiology programme for primary prevention of cardiovascular disease (CVD) compared to routine practice from a health service perspective.

Design

A matched, paired cluster-randomised controlled trial.

Setting

Six pairs of general practices in six countries.

Participants

1019 patients were randomised to the EUROACTION intervention programme and 1005 patients to usual care (UC) and who completed the 1-year follow-up.

Outcome measures

Evidence on health outcomes and costs was based on patient-level data from the study, which had a 1-year follow-up period. Future risk of CVD events was modelled, using published risk models based on patient characteristics. An individual-level Markov model for each patient was used to extrapolate beyond the end of the trial, which was populated with data from published sources. We used an 11-year time horizon and investigated the impact on the cost-effectiveness of varying the duration of the effect of the intervention beyond the end of the trial. Results are expressed as incremental cost per quality-adjusted life-year gained.

Results

Unadjusted results found the intervention to be more costly and also more effective than UC. However, after adjusting for differences in age, gender, country and baseline risk factors, the intervention was dominated by UC, but this analysis was not able to take into account the lifestyle changes in terms of diet and physical activity.

Conclusions

Although the EUROACTION study achieved healthier lifestyle changes and improvements in management of blood pressure and lipids for patients at high risk of CVD, compared to UC, it was not possible to show, using available risk equations which do not incorporate diet and physical activity, that the intervention reduced longer-term cardiovascular risk cost-effectively. Whether or not an intervention such as that offered by EUROACTION is cost-effective requires a longer-term trial with major cardiovascular events as the outcome.

Trial Registration number

ISRCTN 71715857.
Alu and LINE-1 methylation and lung function in the normative ageing study
Authors: Lange Nancy E , Sordillo Joanne , Tarantini Letizia , Bollati Valentina , Sparrow David , Vokonas Pantel , Zanobetti Antonella , Schwartz Joel , Baccarelli Andrea , Litonjua Augusto A , DeMeo Dawn L
Published: October 2012

Objectives

To investigate the association between methylation of transposable elementsAluand long-interspersed nuclear elements (LINE-1) and lung function.

Design

Cohort study.

Setting

Outpatient Veterans Administration facilities in greater Boston, Massachusetts, USA.

Participants

Individuals from the Veterans Administration Normative Aging Study, a longitudinal study of aging in men, evaluated between 1999 and 2007. The majority (97%) were white.

Primary and secondary outcome measures

Primary predictor was methylation, assessed using PCR-pyrosequencing after bisulphite treatment. Primary outcome was lung function as assessed by spirometry, performed according to American Thoracic Society/European Respiratory Society guidelines at the same visit as the blood draws.

Results

In multivariable models adjusted for age, height, body mass index (BMI), pack-years of smoking, current smoking and race,Aluhypomethylation was associated with lower forced expiratory volume in 1 s (FEV1) (β=28 ml per 1% change inAlumethylation, p=0.017) and showed a trend towards association with a lower forced vital capacity (FVC) (β=27 ml, p=0.06) and lower FEV1/FVC (β=0.3%, p=0.058). In multivariable models adjusted for age, height, BMI, pack-years of smoking, current smoking, per cent lymphocytes, race and baseline lung function, LINE-1 hypomethylation was associated with more rapid decline of FEV1(β=6.9 ml/year per 1% change in LINE-1 methylation, p=0.005) and of FVC (β=9.6 ml/year, p=0.002).

Conclusions

In multiple regression analysis,Aluhypomethylation was associated with lower lung function, and LINE-1 hypomethylation was associated with more rapid lung function decline in a cohort of older and primarily white men from North America. Future studies should aim to replicate these findings and determine ifAluor LINE-1 hypomethylation may be due to specific and modifiable environmental exposures.
Access to facility delivery and caesarean section in north-central Liberia: a cross-sectional community-based study
Authors: Gartland Matthew G , Taryor Victor D , Norman Andy M , Vermund Sten H
Published: November 2012

Objective

Rural north-central Liberia has one of the world's highest maternal mortality ratios. We studied health facility birthing service utilisation and the motives of women seeking or not seeking facility-based care in north-central Liberia.

Design

Cross-sectional community-based structured interviews and health facility medical record review.

Setting

A regional hospital and the surrounding communities in rural north-central Liberia.

Participants

A convenience sample of 307 women between 15 and 49 years participated in structured interviews. 1031 deliveries performed in the regional hospital were included in the record review.

Primary outcomes

Delivery within a health facility and caesarean delivery rates were used as indicators of direct utilisation of care and as markers of availability of maternal health services.

Results

Of 280 interview respondents with a prior childbirth, only 47 (16.8%) delivered their last child in a health facility. Women who did not use formal services cited cost, sudden labour and family tradition or religion as their principal reasons for home delivery. At the regional hospital, the caesarean delivery rate was 35.5%.

Conclusions

There is an enormous unmet need for maternal health services in north-central Liberia. Greater outreach and referral services as well as community-based education among women, family members and traditional midwives are vital to improve the timely utilisation of care.