bluuebunny/crossref_metadata_2025 huggingface dataset:
Brain correlates of short‐term habituation to repetitive electrical noxious stimulation
Authors: Nickel F.T. , Ott S. , Möhringer S. , Saake M. , Dörfler A. , Seifert F. , Maihöfner C.
Published: May 2013

Background

Habituation to repetitive noxious stimuli is a well‐known phenomenon. We investigated brain correlates of habituation to pain in a transdermal electrical pain model using functional magnetic resonance imaging (fMRI).

Methods

Electrical painful stimulation with 1 Hz was applied to the volar forearm of 48 healthy subjects for 45 min. Before and after conditioning stimulation, psychophysical testing and fMRI were performed. During fMRI sessions, the subjects underwent blockwise painful electrical stimulation with a fixed percept‐adapted current intensity. After fMRI 1 and fMRI 2 subjects rated the individual pain intensity of the electrical stimulus.

Results

Substantial habituation occurred during conditioning electrical stimulation. Accordingly, areas typically involved in pain processing showed decreased activity after conditioning stimulation. The blood oxygen level‐dependent signal of the subgenual anterior cingulate gyrus, the superior parietal lobule and the supplemental motor area correlated positively with habituation. In contrast, activity in the periaqueductal grey, thalamus and insula correlated negatively. The results of the correlation analyses did not survive correction for multiple comparisons.

Conclusions

With this study, we identified central components associated with habituation to repetitive painful stimuli. The results suggest that an increase in tonic inhibitory activity in cortical pain processing areas is a major mechanism contributing to habituation to phasic noxious stimuli. Moreover, areas involved in descending pain modulation were differentially modulated. This may hint at a simultaneous activation of facilitating and inhibiting nociceptive systems that are both altered in the transdermal electrical pain model.
Platelet transfusions and bleeding complications associated with plasma exchange catheter placement in patients with presumed thrombotic thrombocytopenic purpura
Authors: Duffy Steven M. , Coyle Thomas E.
Published: May 2013

Introduction

Bleeding risk because of thrombocytopenia in patients with thrombotic thrombocytopenic purpura (TTP) often causes concern during placement of the central venous catheter for plasma exchange. This perceived risk of bleeding often triggers prophylactic platelet transfusion; however, the risk of platelet transfusion is unknown.

Methods

Single institution review of bleeding episodes after catheter insertion in patients with suspected TTP.

Results

Fifty‐five thrombocytopenic patients with presumed TTP underwent a total of 57 catheter insertion attempts. There were no major bleeding complications and no bleeding that required invasive intervention. Fourteen patients with a median platelet count of 12,000/µL were transfused with platelets prior to catheter placement. Five (35%) of the transfused patients had minor bleeding complications that did not require intervention. In the nontransfused group, 12 (28%) patients had minor bleeding that did not require invasive intervention and three patients experienced bleeding episodes that resolved after applying direct pressure. Eight (15%) patients died during admission. Mortality in the transfused group was 43% versus 5% in the nontransfused group. In general, patients receiving platelet transfusion prior to catheter insertion were more acutely ill.

Conclusion

There were no major bleeding complications associated with plasma exchange catheter insertion in thrombocytopenic patients with presumed TTP. In light of the uncertain risk of platelet transfusion in patients with TTP, it may be reasonable to forgo prophylactic platelet transfusion prior to catheter placement. J. Clin. Apheresis 28:356–358, 2013. © 2013 Wiley Periodicals, Inc.
Functional morphology of the fin rays of teleost fishes
Authors: Flammang Brooke E. , Alben Silas , Madden Peter G.A. , Lauder George V.
Published: May 2013

Ray‐finned fishes are notable for having flexible fins that allow for the control of fluid forces. A number of studies have addressed the muscular control, kinematics, and hydrodynamics of flexible fins, but little work has investigated just how flexible ray‐finned fish fin rays are, and how flexibility affects their response to environmental perturbations. Analysis of pectoral fin rays of bluegill sunfish showed that the more proximal portion of the fin ray is unsegmented while the distal 60% of the fin ray is segmented. We examined the range of motion and curvatures of the pectoral fin rays of bluegill sunfish during steady swimming, turning maneuvers, and hovering behaviors and during a vortex perturbation impacting the fin during the fin beat. Under normal swimming conditions, curvatures did not exceed 0.029 mm−1 in the proximal, unsegmented portion of the fin ray and 0.065 mm−1 in the distal, segmented portion of the fin ray. When perturbed by a vortex jet traveling at approximately 1 ms−1 (67 ± 2.3 mN s.e. of force at impact), the fin ray underwent a maximum curvature of 9.38 mm−1. Buckling of the fin ray was constrained to the area of impact and did not disrupt the motion of the pectoral fin during swimming. Flexural stiffness of the fin ray was calculated to be 565 × 10−6 Nm2. In computational fluid dynamic simulations of the fin‐vortex interaction, very flexible fin rays showed a combination of attraction and repulsion to impacting vortex dipoles. Due to their small bending rigidity (or flexural stiffness), impacting vortices transferred little force to the fin ray. Conversely, stiffer fin rays experienced rapid small‐amplitude oscillations from vortex impacts, with large impact forces all along the length of the fin ray. Segmentation is a key design feature of ray‐finned fish fin rays, and may serve as a means of making a flexible fin ray out of a rigid material (bone). This flexibility may offer intrinsic damping of environmental fluid perturbations encountered by swimming fish. J. Morphol. 274:1044–1059, 2013. © 2013 Wiley Periodicals, Inc.
Intra‐ and interscanner reliability and reproducibility of 3D whole‐brain pseudo‐continuous arterial spin‐labeling MR perfusion at 3T
Authors: Wu Bing , Lou Xin , Wu Xinhuai , Ma Lin
Published: May 2013

Purpose

To assess the reliability and reproducibility of pseudo‐continuous arterial spin labeling (pCASL). Intra‐ and interscanner reliability and reproducibility are essential before pooling perfusion imaging data.

Materials and Methods

Eight volunteers were scanned three times on two 3.0T magnetic resonance imaging (MRI) scanners using the pCASL technique. The first and third tests were conducted on scanner one, while the second test was on scanner two. The pCASL was acquired with postlabeling delay time (PLD) of 1.5 and 2.5 seconds. The cerebral blood flow (CBF) of gray matter, white matter, frontal lobe, parietal lobe, occipital lobe, temporal lobe, putamen, posterior cingulate, and thalamus were extracted for comparison. Reliability and reproducibility were measured using the intraclass correlation coefficient (ICC) and within‐subject coefficients of variation (wsCV), respectively.

Results

The pCASL consistently had high intra‐ and interscanner measurement reliability and reproducibility. Reproducibility of the CBF values was higher, with PLD 2.5 seconds than with PLD 1.5 seconds. Different PLDs had considerable influence on the reproducibility of the different regions of the brain.

Conclusion

Although excellent intra‐ and interscanner reliability and reproducibility could support the feasibility of cross‐site pooling of ASL data, pCASL with multiple PLDs may better assess the CBF of the human brain. J. Magn. Reson. Imaging 2014;39:402–409. © 2013 Wiley Periodicals, Inc.
1H‐MR spectroscopy characterization of the adipose tissue associated with colorectal tumor
Authors: Mosconi Elisa , Minicozzi Annamaria , Marzola Pasquina , Cordiano Claudio , Sbarbati Andrea
Published: May 2013

Purpose

To investigate colorectal tumor by looking at the lipid tissue around the lesion. Adipose tissue is not only an inert storage system for excess calories, but is involved in several pathological processes linked to tumor development.

Materials and Methods

We obtained 24 colorectal specimens after surgical excision from patients affected by colorectal cancer at different tumor stages. 1H‐MR spectoscopy (MRS) spectra were collected from two voxels, in proximity of the lesion and far from it, in each specimen with a preclinical scanner. We differentiated patients by pathological tumor stage, and we compared the chemical composition of adipose tissue between patient groups, both close the tumor and far from it.

Results

Monounsaturated fatty acids (MUFA) close the lesion are increased at higher tumor stages, while MUFA far from the lesion do not follow this trend. This study is really explorative due to the small numbers of subjects and we are cautious on the interpretation of the results. However, the approach of the present work allows a further insight in the tumor characterization.

Conclusion

Looking at the lipid tissue around a lesion through 1H‐MRS can return important information regarding its genesis and development. J. Magn. Reson. Imaging 2014;39:469–474. © 2013 Wiley Periodicals, Inc.
Texture analysis of ultrahigh field T2*‐weighted MR images of the brain: Application to Huntington's disease
Authors: Doan Nhat Trung , van den Bogaard Simon J.A. , Dumas Eve M. , Webb Andrew G. , van Buchem Mark A. , Roos Raymund A.C. , van der Grond Jeroen , Reiber Johan H.C. , Milles Julien
Published: May 2013

Purpose

To develop a framework for quantitative detection of between‐group textural differences in ultrahigh field T2*‐weighted MR images of the brain.

Materials and Methods

MR images were acquired using a three‐dimensional (3D) T2*‐weighted gradient echo sequence on a 7 Tesla MRI system. The phase images were high‐pass filtered to remove phase wraps. Thirteen textural features were computed for both the magnitude and phase images of a region of interest based on 3D Gray‐Level Co‐occurrence Matrix, and subsequently evaluated to detect between‐group differences using a Mann‐Whitney U‐test. We applied the framework to study textural differences in subcortical structures between premanifest Huntington's disease (HD), manifest HD patients, and controls.

Results

In premanifest HD, four phase‐based features showed a difference in the caudate nucleus. In manifest HD, 7 magnitude‐based features showed a difference in the pallidum, 6 phase‐based features in the caudate nucleus, and 10 phase‐based features in the putamen. After multiple comparison correction, significant differences were shown in the putamen in manifest HD by two phase‐based features (both adjusted P values = 0.04).

Conclusion

This study provides the first evidence of textural heterogeneity of subcortical structures in HD. Texture analysis of ultrahigh field T2*‐weighted MR images can be useful for noninvasive monitoring of neurodegenerative diseases. J. Magn. Reson. Imaging 2014;39:633–640. © 2013 Wiley Periodicals, Inc.
Cancer and inflammation: Differentiation by USPIO‐enhanced MR imaging
Authors: Seyfer Perla , Pagenstecher Axel , Mandic Robert , Klose Klaus‐Jochen , Heverhagen Johannes T.
Published: May 2013

Purpose

To assess ultrasmall superparamagnetic iron oxide particles (USPIO) ‐enhanced MR imaging for the differentiation of malignant from benign, inflammatory lesions.

Materials and Methods

In this study, approved by the local animal care committee, VX2 carcinoma and intramuscular abscesses were implanted into the hind thighs of New Zealand White rabbits. MR imaging was performed pre contrast and serially for 24 h after the injection of USPIO. MR findings were compared with histopathologic results based on Prussian blue stains for the presence of iron.

Results

Twenty‐four hours after the Ferumoxtran‐injection, no changes were observed in VX2 carcinomas, whereas a mean reduction of the contrast‐to‐noise ratio (CNR) of approximately 90% was noticed in abscesses as well as in necrotic tumors. On histopathologic examination, abscess and necrotic parts of the tumor were found to include iron‐containing monocytes demonstrating that the reduction in CNR was caused by USPIO‐tagged monocytes.

Conclusion

Our results prove the ability of USPIO‐enhanced MRI to differentiate benign, inflammatory from malignant lesions. J. Magn. Reson. Imaging 2014;39:665–672. © 2013 Wiley Periodicals, Inc.
Assessment of cardiac volumes using an isotropic whole‐heart dual cardiac phase sequence in pediatric patients
Authors: Delgado Jorge A. , Abad Pedro , Rascovsky Simon , Calvo Victor , Castrillon Gabriel , Greil Gerald , Uribe Sergio
Published: May 2013

Purpose

To evaluate the accuracy of a three‐dimensional dual phase (3D DP) whole‐heart technique for cardiac volumetric assessment in pediatric patients with cardiac abnormalities.

Materials and Methods

The institutional approved this study, and informed consent was obtained from patients or their guardians. This prospective study involved 31 pediatric patients (mean age, 7.9 years; range, 15 days to 15 years) for the assessment of cardiac abnormalities using cardiovascular MR. A standard protocol was performed for assessing cardiac anatomy and function. For evaluating the 3D DP technique, statistical comparison with a 2D cine multi‐slice technique (2D steady‐state free‐precession [SSFP]) was performed using linear regression, intraclass correlation coefficient, and Bland Altman plots.

Results

Left (LV) and right (RV) ventricular cardiac volumes obtained with the 3D DP technique were in strong agreement with those obtained with the 2D SSFP technique for small and large ventricular volumes. The intraclass correlation coefficients (ICC) between both techniques were 0.992 for the LV end‐diastolic volume (EDV), 0.983 for the LV end‐systolic volume (ESV), 0.952 for the LV‐systolic volume (SV), 0.992 for the RV‐EDV, 0.992 for the RV‐ESV, 0.928 for the RV‐SV. Interobserver analysis indicated good reproducibility for both the 2D SSFP and the 3D DP techniques.

Conclusion

The 3D DP technique provides as accurate cardiac volumes as the 2D SSFP technique in the pediatric population, but with the added benefits of easier data acquisition and detailed anatomical information of the whole heart and great vessels in a single free‐breathing scan. J. Magn. Reson. Imaging 2014;39:708–716. © 2013 Wiley Periodicals, Inc.
New dynamic three‐dimensional MRI technique for shoulder kinematic analysis
Authors: Pierrart Jérôme , Lefèvre‐Colau Marie‐Martine , Skalli Wafa , Vuillemin Valérie , Masmejean Emmanuel H. , Cuénod Charles A. , Gregory Thomas M.
Published: May 2013

Purpose

To establish a new imaging technique using dynamic MRI three‐dimensional (3D) volumetric acquisition in real‐time, on six normal shoulders for the analysis of the 3D shoulder kinematics during continuous motion.

Materials and Methods

At first, a standard static acquisition was performed. Then, fast images were obtained with a multi‐slice 3D balanced gradient echo sequence to get a real time series during the initial phase of shoulder abduction. Subsequently, the images were reconstructed; registered and the translational patterns of the humeral head relative to the glenoid and the size of the subacromial space were calculated. Additionally, the intraobserver reproducibility was tested.

Results

The maximal abduction was on average 43° (30° to 60°) and the mean width of the subacromial space was 7.7 mm (SD: ± 1.2 mm). Difference between extreme values and average values was low, respectively 2.5 mm on X‐axis, 2 mm on Y‐axis, 1.4 mm for the width of the subacromial space and 1.2° for the measure of the glenohumeral abduction.

Conclusion

This study reported a dynamic MRI protocol for the monitoring of shoulder 3D kinematics during continuous movement. The results suggest that there is no superior shift of the humeral head during the first phase of abduction. J. Magn. Reson. Imaging 2014;39:729–734. © 2013 Wiley Periodicals, Inc.
Black and Minority Ethnic Leaders in the Health Sector
Authors: Ashraf Fahmida
Published: May 2013

As several studies indicate, the National Health Service (NHS) in the United Kingdom is one of the largest employers for Black and minority ethnic (BME) people. Despite many positive action (PA) initiatives to support disadvantaged groups, only a handful of people have managed to progress to senior management. This article considers published literature in relation to BME leadership in NHS and the specific types of PA activities that have been set up to address some issues around inequality. In addition to PA activities, the article also considers the U.K. equality framework. Positive action is allowed under the U.K. legislation for organizations to recruit people from underrepresented communities on merit. It allows organizations to create different initiatives for people to gain appropriate qualifications, skills, and experience to compete for promotions or for better job opportunities.
Degrees of Success
Authors: Johnson Stacy , Scammell Janet , Serrant‐Green Laura
Published: May 2013

By the end of 2013, all programs leading to the registered nurse qualification in the United Kingdom will be at the bachelor's degree level. There is concern that all‐degree nursing education might threaten the diversity of the future nursing workforce in the United Kingdom.

This article reports on a qualitative pilot study exploring the critical issues for access, recruitment, and retention of Black and minority ethnic (BME) students in U.K. nursing degree programs from the students' perspective. The study utilized action research, and this article reports on the first two stages of the action research cycle, problem identification and identification of actions. The data were collected through focus groups and interviews with BME students and then analyzed with iterative thematic analysis.

The objective was to inform an action framework for U.K. universities devising access, recruitment, admission, and retention practice for BME students when U.K. nurse training becomes all degree.
Substance Abuse Needs Assessment
Authors: Lidster Olwyn , Cannon Violet M. P.
Published: May 2013

This article describes and reflects on a service evaluation of drug and alcohol provision for Gypsy and Traveller communities in a city in the north of England. Findings from the study are presented, along with findings from existing literature on engaging and supporting Gypsy and Traveller communities in accessing health care services. The article reports similarities between the current study and previous studies in regard to substance abuse problems in these communities and barriers to accessing services. Gypsy and Traveller perceptions of heath care provision are thematically analyzed, and recommendations for both future studies and service improvement are made based on these perceptions.

The findings from the study mirror results from existing studies regarding feelings of pride and shame being a barrier to accessing services as well as fear of discrimination. It is clear from the findings that some Gypsies and Travellers do have drug or alcohol problems, or both, in their communities and that they do not know where they can go for help. There were two overarching themes from the responses to all the questions asked: “shame” in admitting they had a problem and services not understanding their culture. Many suggested that people from their own community who understand them working in services would be helpful. The findings indicate issues that health care providers need to consider in preparing this population for effective, accessible substance abuse treatment.
A Comparative Analysis of Affirmative Action in the United Kingdom and United States
Authors: Archibong Uduak , Sharps Phyllis W.
Published: May 2013

Based on research conducted during a large‐scale European Commission project on international perspectives on positive/affirmative action measures, the authors provide a comparative analysis of the legal context and perceptions of the impact of positive action in the United Kingdom and the United States. The study adopted participatory methods including consensus workshops, interviews, and legal analysis to obtain data from those individuals responsible for designing and implementing positive action measures. Findings are discussed, conclusions drawn, and wide‐ranging recommendations are made at governmental and organizational levels. The authors conclude by suggesting possible implications for policy and argue for widespread awareness‐raising campaigns of both the need for positive action measures for disadvantaged groups and the benefits of such measures for wider society. They also recommend the adoption of a more coherent and collaborative approach to the utilization and evaluation of the effectiveness of positive or affirmative action.
Isolation and foaming functionality of acid‐soluble protein from lupin (Lupinus angustifolius) kernels
Authors: Wong Alester , Pitts Keith , Jayasena Vijay , Johnson Stuart
Published: May 2013

BACKGROUND

Australian sweet lupin (ASL) protein is conventionally isolated by alkaline extraction/acid precipitation, leaving a waste stream containing acid‐soluble proteins (ASPs) and contaminating raffinose family oligosaccharides (RFOs). The foaming functionality of ASP isolated from ASL is not known, but ASP from another lupin species has demonstrated high foaming functionality.

RESULTS

Pre‐soaking ASL kernels increased their protein/RFO ratio; however, some protein was lost by soaking. The foaming capacity of ASL protein isolated by different methods was ranked in the following order: alkaline extraction/isoelectric precipitation < direct acid extraction (novel ASP) < supernatant from isoelectric precipitation (conventional ASP) < ultrafiltered novel ASP = fresh egg white. Electrophoresis indicated enrichment of γ‐conglutin and albumin peptides in ASPs and of a single peptide in the fibre residue from alkaline extraction.

CONCLUSION

The high foaming capacity of ultrafiltered novel ASP, similar to that of fresh egg white, indicates the potential of this lupin protein as a food ingredient for foaming applications. © 2013 Society of Chemical Industry
SPE and purification of DNA using magnetic particles
Authors: Rittich Bohuslav , Španová Alena
Published: May 2013

Superparamagnetic particles have been attractive for molecular diagnostics and analytical chemistry applications due to their unique magnetic properties and their ability to interact with various biomolecules of interest. This paper presents a critical overview of magnetic nano‐ and microparticles used as a solid phase for extraction and purification of DNAs. The mechanisms of DNA binding to the surface of functionalised magnetic particles are described. The most widely used materials including silica supports, organic polymers and other materials, mostly containing magnetite or paramagnetic metallic elements are reviewed. The main application areas of magnetic particles for DNA separation are briefly described.
A facile and efficient one‐step strategy for the preparation of β‐cyclodextrin monoliths
Authors: Guo Jialiang , Zhang Qiaoxuan , Peng Yongbo , Liu Zhenghua , Rao Longyi , He Teng , Crommen Jacques , Sun Pinghua , Jiang Zhengjin
Published: May 2013

A novel, facile, and efficient one‐step copolymerization strategy was developed for the preparation of β‐cyclodextrin (β‐CD) methacrylate monolithic columns using click chemistry. The novel mono‐(1H‐1,2,3‐triazol‐4‐ylmethyl)‐2‐methylacryl‐β‐CD monomer was synthesized by a click reaction between propargyl methacrylate and mono‐6‐azido‐β‐CD, and then monolithic columns were prepared through a one‐step in situ copolymerization of the mono‐(1H‐1,2,3‐triazol‐4‐ylmethyl)‐2‐methylacryl‐β‐CD monomer and ethylene dimethacrylate. The physicochemical properties and column performance of the fabricated monolithic columns were characterized by elemental analysis, SEM, and micro‐HPLC. Satisfactory column permeability, efficiency, and separation performance were obtained for the optimized poly(mono‐(1H‐1,2,3‐triazol‐4‐ylmethyl)‐2‐methylacryl‐β‐CD‐co‐ethylene dimethacrylate) monolithic columns. Additionally, typical hydrophilic interaction chromatography retention behavior was observed on the monoliths at high acetonitrile content in the mobile phase. Although the enantioselectivity of our monolithic columns did not meet the level of other reported β‐CD monolithic columns, this one‐step strategy based on click chemistry still provides an interesting and effective model as it offers the possibility to easily prepare related novel CD methacrylate monoliths through a one‐step copolymerization strategy.
Molecular Biology and Inhibitors of Hepatitis A Virus
Authors: Debing Yannick , Neyts Johan , Thibaut Hendrik Jan
Published: May 2013

Hepatitis A virus (HAV) is a faeco‐orally transmitted picornavirus and is one of the main causes of acute hepatitis worldwide. An overview of the molecular biology of HAV is presented with an emphasis on recent findings. Immune evasion strategies and a possible correlation between HAV and atopy are discussed as well. Despite the availability of efficient vaccines, antiviral drugs targeting HAV are required to treat severe cases of fulminant hepatitis, contain outbreaks, and halt the potential spread of vaccine‐escape variants. Additionally, such drugs could be used to shorten the period of illness and decrease associated economical costs. Several known inhibitors of HAV with various mechanisms of action will be discussed. Since none of these molecules is readily useable in the clinic and since the availability of an anti‐HAV drug would be of clinical importance, increased efforts should be targeted toward discovery and development of such antivirals.
Adiabatic inversion pulses for myocardial T1 mapping
Authors: Kellman Peter , Herzka Daniel A. , Hansen Michael Schacht
Published: May 2013

Purpose

To evaluate the error in T1 estimates using inversion‐recovery‐based T1 mapping due to imperfect inversion and to perform a systematic study of adiabatic inversion pulse designs in order to maximize inversion efficiency for values of transverse relaxation (T2) in the myocardium subject to a peak power constraint.

Methods

The inversion factor for hyperbolic secant and tangent/hyperbolic tangent adiabatic full passage waveforms was calculated using Bloch equations. A brute‐force search was conducted for design parameters: pulse duration, frequency range, shape parameters, and peak amplitude. A design was selected that maximized the inversion factor over a specified range of amplitude and off‐resonance and validated using phantom measurements. Empirical correction for imperfect inversion was performed.

Results

The tangent/hyperbolic tangent adiabatic pulse was found to outperform hyperbolic secant designs and achieve an inversion factor of 0.96 within ±150 Hz over 25% amplitude range with 14.7 µT peak amplitude. T1 mapping errors of the selected design due to imperfect inversion was ∼4% and could be corrected to <1%.

Conclusions

Nonideal inversion leads to significant errors in inversion‐recovery‐based T1 mapping. The inversion efficiency of adiabatic pulses is sensitive to transverse relaxation. The tangent/hyperbolic tangent design achieved the best performance subject to the peak amplitude constraint. Magn Reson Med 71:1428–1434, 2014. © 2013 Wiley Periodicals, Inc.
A hybrid association rule mining approach for characterizing network traffic behaviour
Authors: Liu Bin , Li Yuefeng
Published: May 2013

Understanding network traffic behaviour is crucial for managing and securing computer networks. One important technique is to mine frequent patterns or association rules from analysed traffic data. On the one hand, association rule mining usually generates a huge number of patterns and rules, many of them meaningless or user‐unwanted; on the other hand, association rule mining can miss some necessary knowledge if it does not consider the hierarchy relationships in the network traffic data. Aiming to address such issues, this paper proposes a hybrid association rule mining method for characterizing network traffic behaviour. Rather than frequent patterns, the proposed method generates non‐similar closed frequent patterns from network traffic data, which can significantly reduce the number of patterns. This method also proposes to derive new attributes from the original data to discover novel knowledge according to hierarchy relationships in network traffic data and user interests. Experiments performed on real network traffic data show that the proposed method is promising and can be used in real applications. Copyright © 2013 John Wiley & Sons, Ltd.
One‐step Separation and Purification of Three Lignans and One Flavonol from Sinopodophyllum emodi by Medium‐pressure Liquid Chromatography and High‐speed Counter‐current Chromatography
Authors: Wang Ping , Liu Yongling , Chen Tao , Xu Wenhua , You Jinmao , Liu Yongjun , Li Yulin
Published: May 2013

Introduction

Lignans and flavonols are the primary constituents of Sinopodophyllum emodi and have been used as cathartic, anthelmintic, chemotherapeutic and anti‐hypertensive compounds. Although these compounds have been isolated, there have been no reports on the separation of 4′‐demethyl podophyllotoxin, podophyllotoxin, deoxypodophyllotoxin and kaempferol in one step by medium‐pressure liquid chromatography (MPLC) and high‐speed counter‐current chromatography (HSCCC).

Objective

Development of an efficient method for the preparative separation and purification of three lignans and one flavonol from S. emodi.

Methods

The precipitate of crude extracts was first separated by MPLC into four parts, numbered GJ‐1, GJ‐2, GJ‐3 and GJ‐4. GJ‐1 was separated and purified by HSCCC using a solvent system composed of n‐hexane:ethyl acetate:methanol:water (1.75:1.5:1:0.75, v/v/v/v). The purities of the target compounds were assessed using high‐performance liquid chromatography (HPLC) and chemical structures were identified by 1H‐NMR and 13C‐NMR.

Results

The HSCCC and MPLC methods were successfully used for the preparative separation and purification of 4′‐demethyl podophyllotoxin (8.5 mg, 92.4%), podophyllotoxin (40.1 mg, 92.1%), deoxypodophyllotoxin (4.6 mg, 98.1%), and kaempferol (1.6 mg, 96.7%) from a 100 mg sample.

Conclusion

Three lignans (4′‐demethyl podophyllotoxin, podophyllotoxin, deoxypodophyllotoxin) and one flavonol (kaempferol) were successfully isolated by HSCCC and MPLC in one step. Copyright © 2013 John Wiley & Sons, Ltd.
Effectiveness of cognitive behavioral therapy: An evaluation of therapies provided by trainees at a university psychotherapy training center
Authors: Hiltunen Arto J. , Kocys Elo , Perrin‐Wallqvist Renée
Published: May 2013

At the psychotherapy training center at Karlstad University, a study was carried out to examine the levels of symptom change and satisfaction with therapy in a heterogeneous population of clients treated using cognitive behavioral therapy (CBT) by less experienced trainee therapists with limited theoretical education. The clients received an average of 11 therapy sessions. The results suggested that CBT performed by less experienced trainee therapists can be effective. According to client estimations, a statistically significant reduction in symptoms, measured using the Symptoms Checklist, was achieved for seven of nine variables (p ≤ .006), as well as a significant increase in satisfaction with life (p ≤ .001). Also, the pre‐ and posttherapy measurements using the Montgomery–Åsberg Depression Rating Scale showed a statistically significant improvement in the clients' condition. According to the therapists' estimations, 64% (SD = 32.01) of the clients experienced a significant improvement in their condition. In addition, the results of a survey of client satisfaction demonstrated that the clients were very pleased with the therapy received. Also the therapists were, to a great extent, satisfied with the treatment process itself, including the supervision received, and very satisfied with the client alliance. A correlation analysis between the clients' perceived level of improvement and therapist satisfaction showed a strong correlation between the two variables (r = .50, p < .005). By including the Comparative Psychotherapy Process Scale (CPPS) in our study it was possible to measure trueness to therapy form. An analysis of the CPPS results confirmed that the form of therapy used at the training site was more strongly CBT than psychodynamic interpersonal treatment (p ≤ .001). The CBT subscale score indicated that the therapy was characteristic of CBT, confirming that the interventions used in the therapy belong to the CBT genre.
Polyamide 6–Cellulose Composites: Effect of Cellulose Composition on Melt Rheology and Crystallization Behavior
Authors: Kiziltas Alper , Nazari Behzad , Gardner Douglas J. , Bousfield Douglas W.
Published: May 2013

Melt rheology and crystallization behavior of polyamide 6 (PA 6) and microcrystalline cellulose (MCC) composites were systematically studied in this research. The incorporation of MCC into the PA 6 matrix resulted in higher complex viscosities (|η*|), storage modulus (G′), and shear viscosities than those of neat PA 6, especially at low frequencies. The orientation of rigid molecular chains in the composites introduced by the addition of MCC induced a strong shear thinning behavior with an increase in MCC loading. The non‐isothermal crystallization kinetics of PA 6 and MCC composites were investigated by differential scanning calorimetry. The Avrami and Tobin model were applied to describe the process of non‐isothermal crystallization and to determine the crystallization parameters of the composites. Analysis of the crystallization kinetics indicated that the Avrami (na) and Tobin exponent (nt) was altered by the MCC. It was also found that the Avrami and Tobin equations fit the empirical data well. POLYM. ENG. SCI., 54:739–746, 2014. © 2013 Society of Plastics Engineers
Systematic research on the pretreatment of peptides for quantitative proteomics using a C18 microcolumn
Authors: Zhai Linhui , Chang Cheng , Li Ning , Duong Duc M. , Chen Hao , Deng Zixin , Yang Jian , Hong Xuechuan , Zhu Yunping , Xu Ping
Published: May 2013

Reversed phase microcolumns have been widely used for peptide pretreatment to desalt and remove interferences before tandem LC–MS in proteomics studies. However, few studies have characterized the effects of experimental parameters as well as column characteristics on the composition of identified peptides. In this study, several parameters including the concentration of ACN in washing buffer, the microcolumn's purification effect, the peptide recovery rate, and the dynamic‐binding capacity were characterized in detail, based upon stable isotope labeling by amino acids in a cell culture quantitative approach. The results showed that peptide losses can be reduced with low ACN concentration in washing buffers resulting in a recovery rate of approximately 82%. Furthermore, the effects of ACN concentration and loading amount on the properties of identified peptides were also evaluated. We found that the dynamic‐binding capacity of the column was approximately 26 μg. With increased loading amounts, more hydrophilic peptides were replaced by hydrophobic peptides.
Digital Boundary Objects as Negotiation Facilitators: Spanning Boundaries in Virtual Engineering Project Networks
Authors: Alin Pauli , Iorio Josh , Taylor John E.
Published: May 2013

Advances in electronic communication tools have enabled collaborative engineering work to be conducted in virtual project networks that utilize “digital boundary objects” to exchange complex design knowledge. However, little is known about whether and how digital boundary objects facilitate negotiations in virtual settings that feature real-time communication. This article addresses this gap by exploring the role of digital boundary objects in negotiating complex design knowledge in a three-dimensional (3-D) virtual workspace. The authors found that digital boundary objects facilitate negotiations through a three-stage process of structuring negotiation space, structuring knowledge in the structured negotiation space, and framing combinations of structured knowledge.
Resource Commitment, Organizational Diversity, and Research Performance: A Case of the National Telecommunication Program in Taiwan
Authors: Hung Chia-Liang , Chou Jerome Chih-Lung
Published: May 2013

Traditionally, a project team's resource commitment and organizational diversity are thought to be helpful to project performance; however, this relationship may falter when the project performance is considered in light of both cost and benefit. This paper integrates data envelopment analysis (DEA) and analytical hierarchy process (AHP) to evaluate project performance and explores the relationship between project performance and resource commitment and organizational diversity. The empirical study of research teams in the Taiwan National Telecommunication Program shows mixed results of this relationship. Implications for project management and governmental subsidy policy in dealing with resource commitment and organizational diversity are discussed.
Effects of High Performance Work Practices on Job Performance in Project-Based Organizations
Authors: Wickramasinghe Vathsala , Liyanage Suyama
Published: May 2013

This article investigates high performance work practices used in project-based globally distributed software development firms in Sri Lanka and their effects on job performance. A random sample of 220 employees engaged full-time in globally distributed software development firms in Sri Lanka responded. For the data analysis, descriptive statistics, factor analysis, correlation analysis, and multiple regression analysis were used. Three main high performance work practices were identified by the analysis, namely, performance evaluation, learning and development, and involvement in decision making. These three practices significantly and positively predict job performance of employees attached to project-based globally distributed software development firms.
A Bayesian network‐based approach for learning attack strategies from intrusion alerts
Authors: Kavousi Fatemeh , Akbari Behzad
Published: May 2013

A tremendous number of low‐level alerts reported by information security systems clearly reflect the need for an advanced alert correlation system to reduce alert redundancy, correlate security alerts, detect attack strategies, and take appropriate actions against upcoming attacks. Up to now, a variety of alert correlation methods have been suggested. However, most of them rely on a priori and hard‐coded domain expert knowledge that leads to their difficult implementation and limited capabilities of detecting new attack strategies. To overcome the drawbacks of these approaches, the recent trend of research in alert correlation has gone towards extracting attack strategies through automatic analysis of intrusion alerts. In line with the recent researches, in this paper, we present new algorithms to automatically mine attack behavior patterns from historical alerts as accurately and efficiently as possible. Our system is composed of two main components. The first offline component automatically generates correlation rules by analyzing the previously observed alerts using a Bayesian causality analysis mechanism. Then, in the online alert correlation component, alerts are correlated using a hierarchical scheme and based on the extracted rules. Our experimental results clearly show efficiency of the proposed method in learning new attack strategies. Copyright © 2013 John Wiley & Sons, Ltd.
Security analysis of GCM for communication
Authors: Yap Wun‐She , Yeo Sze Ling , Heng Swee‐Huay , Henricksen Matt
Published: May 2013

The Galois/Counter Mode of operations (GCM) is constructed by combining the counter mode encryption and the authentication component (i.e., GTAG) to provide both privacy and authenticity. GTAG can be used as a stand‐alone message authentication code. In this paper, we analyze the security of GTAG and GCM with respect to the forgery and distinguishing attacks. More precisely,

We generalize the set of weak key classes proposed by Saarinen in FSE 2012 to include all subsets of nonzero keys. Hence, we remove the condition on the smoothness of 2n − 1, where n denotes the block size, for the existence of weak key classes.

By considering powers of suitable field elements and linearized polynomials, we further exploit some specific weak key classes to present a universal forgery attack on GTAG.

By invoking the birthday paradox arguments, we show that a chosen message attack can be used to distinguish GTAG from a random function.

To relax the assumptions required in the universal forgery attack, we show that we can utilize the uniqueness of the counter mode encryption to launch a known ciphertext attack against GCM itself when the initial vector is restricted to 96 bits.

The first three attacks can be applied to other Wegman–Carter polynomial message authentication codes. Copyright © 2013 John Wiley & Sons, Ltd.
A Metatheoretical Evaluation of Chaordic Systems Thinking
Authors: Edwards Mark G.
Published: May 2013

This paper presents a metatheoretical evaluation of chaordic systems thinking (ChST) as it applies to organizational transformation. The diversity of approaches to transformation means that it is rich territory for metatheoretical research. ChST can be regarded as a metatheoretical attempt to integrate conceptual lenses so that a richer conceptualisation of transformation can be developed. ChST aims to be an integrative and innovative theoretical contribution to understanding change. How might these claims be evaluated? A metatheoretical method called metatriangulation is applied here to evaluate the ChST framework. A review and analysis of 20 ChST texts was performed and found that the approach shares several lenses with other theories of organizational transformation, but it also omits some important lenses and only partially described others. Recommendations for the further development of ChST are presented. Although important for developing novel insights, metatheoretical research is rarely performed systematically. This paper presents an original approach to building and evaluating overarching frameworks for organizational transformation. Copyright © 2013 John Wiley & Sons, Ltd.
Stress differentially alters mu opioid receptor density and trafficking in parvalbumin‐containing interneurons in the female and male rat hippocampus
Authors: Milner Teresa A. , Burstein Suzanne R. , Marrone Gina F. , Khalid Sana , Gonzalez Andreina D. , Williams Tanya J. , Schierberl Kathryn C. , Torres‐Reveron Annelyn , Gonzales Keith L. , Mcewen Bruce S. , Waters Elizabeth M.
Published: May 2013

Stress differentially affects hippocampal‐dependent learning relevant to addiction and morphology in male and female rats. Mu opioid receptors (MORs), which are located in parvalbumin (PARV)‐containing GABAergic interneurons and are trafficked in response to changes in the hormonal environment, play a critical role in promoting principal cell excitability and long‐term potentiation. Here, we compared the effects of acute and chronic immobilization stress (AIS and CIS) on MOR trafficking in PARV‐containing neurons in the hilus of the dentate gyrus in female and male rats using dual label immunoelectron microscopy. Following AIS, the density of MOR silver‐intensified gold particles (SIGs) in the cytoplasm of PARV‐labeled dendrites was significantly reduced in females (estrus stage). Conversely, AIS significantly increased the proportion of cytoplasmic MOR SIGs in PARV‐labeled dendrites in male rats. CIS significantly reduced the number of PARV‐labeled neurons in the dentate hilus of males but not females. However, MOR/PARV‐labeled dendrites and terminals were significantly smaller in CIS females, but not males, compared with controls. Following CIS, the density of cytoplasmic MOR SIGs increased in PARV‐labeled dendrites and terminals in females. Moreover, the proportion of near‐plasmalemmal MOR SIGs relative to total decreased in large PARV‐labeled dendrites in females. After CIS, no changes in the density or trafficking of MOR SIGs were seen in PARV‐labeled dendrites or terminals in males. These data show that AIS and CIS differentially affect available MOR pools in PARV‐containing interneurons in female and male rats. Furthermore, they suggest that CIS could affect principal cell excitability in a manner that maintains learning processes in females but not males. Synapse 67:757–772, 2013. © 2013 Wiley Periodicals, Inc.
Motivation and Test Anxiety in Test Performance Across Three Testing Contexts: The CAEL, CET, and GEPT
Authors: Cheng Liying , Klinger Don , Fox Janna , Doe Christine , Jin Yan , Wu Jessica
Published: May 2013

This study examined test‐takers' motivation, test anxiety, and test performance across a range of social and educational contexts in three high‐stakes language tests: the Canadian Academic English Language (CAEL) Assessment in Canada, the College English Test (CET) in the People's Republic of China, and the General English Proficiency Test (GEPT) in Taiwan. The researchers issued a questionnaire exploring motivation, test anxiety, and perceptions of test importance and purpose to test‐takers in each of the three contexts. A total of 1,281 valid questionnaire responses were obtained: 255 from CAEL, 493 from CET, and 533 from GEPT. Questionnaire responses were linked to each test‐taker's respective test performance. The results illustrate complex interrelationships of test‐takers' motivation and test anxiety in their test performance. Differences in motivation and test anxiety emerged with regard to social variables (i.e., test importance to stakeholders and test purposes). Further, motivation and test anxiety, along with personal variables (i.e., gender and age), were associated with test performance. Given that motivation and test anxiety have typically been examined separately and in relation to a single testing context, this study addresses an important research gap.
First Steps in the Management of Pericardial Effusion: Who Was First to Relieve the Pericardial Sac—Larrey or Romero?
Authors: Tóth Imre , Rami‐Porta Ramon , Rendeki Szilárd , Molnár Tamás F.
Published: May 2013

Early reports told us that the first pericardiotomy was performed by Baron Dominique Jean Larrey, Napoleon’s chief military surgeon. In this article, we reveal a previous operation of that kind and its publication by Francisco Romero, who had a 9‐year head start over Larrey’s performance. The aim of this article was to briefly review the two‐century‐old history of pericardial fenestration.
NIPT in a Clinical Setting: An analysis of Uptake in the First Months of Clinical Availability
Authors: Taylor Joanne B. , Chock Valerie Y. , Hudgins Louanne
Published: May 2013

The objective of our study was to describe the clinical experience in offering noninvasive prenatal testing (NIPT) for aneuploidy to pregnant patients, highlighting the clinical utility, barriers to acceptance and limitations of this novel test. Data were collected from 961 patients offered NIPT from 3/1/12 to 9/30/12. Univariate and multivariate logistic regression analysis was performed. Twenty‐eight percent of patients elected NIPT and 72 % declined. Women continue to elect less sensitive and less specific screening through biochemical markers and nuchal translucency. Women considering all options at average risk for aneuploidy were less likely to accept NIPT testing than women who had a risk adjustment from an ultrasound marker or routine screening test. In our multi‐ethnic population, Filipina women were significantly less likely to elect NIPT compared to other ethnicities. Five percent of NIPT ordered failed analysis. Several chromosome abnormalities were detected through CVS or amniocentesis that would not have been detected by NIPT. Even though NIPT offers a non‐invasive, highly sensitive and specific analysis for aneuploidy, the majority of women in our study declined this option. NIPT should be offered in the context of genetic counseling so that women understand the limitations of the testing and make an educated decision about the testing option best suited to their situation.