bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistically-based damage detection in geometrically-complex structures using ultrasonic interrogation
Authors: Haynes Colin , Todd Michael D , Flynn Eric , Croxford Anthony
Published: December 2012

This article introduces a novel approach to damage detection in the context of a structural health monitoring system. A statistical model of the ultrasonic guided wave interrogation process was developed and used to formulate a likelihood ratio test. From the likelihood ratio test, the optimal detector for distinguishing damaged and undamaged states of the structure was derived and found to be a metric related to signal energy. That result was confirmed using a data-driven approach based on using receiver-operating characteristic curves to compare the energy metric to other metrics found in the literature. The data in this study were generated from instrumenting two separate, geometrically complex structures with ultrasonic sensor–actuators. A three-story bolted-frame structure was constructed in the laboratory to test the approach for connections that produce highly uncertain wave paths, with damage being introduced through local impedance changes and bolt loosening. The second test structure was a section of a fuselage rib taken from a commercial aircraft in which holes and cracks were introduced to provide a testbed with a high degree of realism. The detection performance in both structures was quantified and presented. Finally, different sensor fusion strategies were implemented and the ability of such techniques to increase the statistical distinction between damaged and undamaged cases was quantified.
Comparison of metrics to monitor and compensate for piezoceramic debonding in structural health monitoring
Authors: Mulligan Kyle R , Quaegebeur Nicolas , Ostiguy Pierre-Claude , Masson Patrice , Létourneau Sylvain
Published: December 2012

This article investigates metrics to assess and compensate for the degradation of the adhesive layer of surface-bonded piezoceramic transducers for structural health-monitoring applications. Capacitance, resonance frequency, and modal damping parameters are derived from admittance curves using a lumped parameter model to monitor the degradation of the transducer adhesive layer. A pitch-catch configuration is then used to discriminate the effect of bonding degradation on actuation and sensing. It is shown that below the first mechanical resonance frequency of the piezoceramic transducers, the degradation causes a decrease in the amplitude of the transmitted and received signals, while above resonance, in addition to a decrease in the amplitude of the transmitted and received signals, a linear phase shift is observed. A signal-correction factor is proposed to adjust signals based on adhesive degradation evaluated using the measured modal damping. The benefits of the signal-correction factor are demonstrated in the frequency domain for both the A0 and S0 modes.
Child Sexual Abuse in the Etiology of Anxiety Disorders
Authors: Maniglio Roberto
Published: December 2012

There is considerable controversy about the role of child sexual abuse in the etiology of anxiety disorders. Although a growing number of research studies have been published, these have produced inconsistent results and conclusions regarding the nature of the associations between child sexual abuse and the various forms of anxiety problems as well as the potential effects of third variables, such as moderators, mediators, or confounders. This article provides a systematic review of the several reviews that have investigated the literature on the role of child sexual abuse in the etiology of anxiety disorders. Seven databases were searched, supplemented with hand search of reference lists from retrieved papers. Four meta-analyses, including 3,214,482 subjects from 171 studies, were analyzed. There is evidence that child sexual abuse is a significant, although general and nonspecific, risk factor for anxiety disorders, especially posttraumatic stress disorder, regardless of gender of the victim and severity of abuse. Additional biological or psychosocial risk factors (such as alterations in brain structure or function, information processing biases, parental anxiety disorders, family dysfunction, and other forms of child abuse) may interact with child sexual abuse or act independently to cause anxiety disorders in victims in abuse survivors. However, child sexual abuse may sometimes confer additional risk of developing anxiety disorders either as a distal and indirect cause or as a proximal and direct cause. Child sexual abuse should be considered one of the several risk factors for anxiety disorders and included in multifactorial etiological models for anxiety disorders.
A New Measure of State Government Ideology, and Evidence that Both the New Measure and an Old Measure Are Valid
Authors: Berry William D. , Fording Richard C. , Ringquist Evan J. , Hanson Russell L. , Klarner Carl
Published: December 2012

We modify Berry et al.‘s congressional-delegation-based measure of state government ideology to construct a new measure—which we call the state-legislative-based state government ideology measure—by relying on Shor and McCarty's National Political Awareness Test common space estimates of the ideal points of U.S. state legislators. We conduct tests of convergent and construct validity for the two measures. We find that they correlate highly in each year for which the state-legislative-based indicator is available (1995–2008), and when observations are pooled across all years. We also replicate numerous published studies assessing the impact of state government ideology using each indicator of ideology and find that the two measures nearly always yield similar conclusions about the effect of government ideology. Because the state-legislative-based measure is based on more direct estimates of the ideal points of state legislators than is the congressional-delegation-based measure—which uses estimates of ideal points for members of Congress from the same state as a proxy—we believe the state-legislative-based measure is superior, and we recommend that scholars use it when it is available for the state-years being studied. Because our empirical evidence indicates that Berry et al.‘s congressional-delegation-based measure is also valid—and it is available for a much longer period (annually beginning in 1960)—we advise that it be used when the state-legislative-based measure is not available.
Multimodal Therapy Concept and Aerobic Training in Breast Cancer Patients With Chronic Cancer-Related Fatigue
Authors: Kröz Matthias , Fink Matthias , Reif Marcus , Grobbecker Siglinde , Zerm Roland , Quetz Michaele , Frühwirth Matthias , Brinkhaus Benno , Bartsch Christian , Girke Matthias , Gutenbrunner Christoph
Published: December 2012

Hypothese:

Cancer-related fatigue (CRF) and sleep disorders are some of the most wearing and common symptoms in disease-free breast cancer patients (BC). Aerobic training (AT) is the treatment with the best available evidence, even though it seems to be insufficient with regards to improvements in cognitive fatigue. We introduced a new multimodal therapy concept (MM) consisting of psycho-, sleep-education and new approaches based on anthroposophic medicine such as eurythmy and painting therapy.

Study design:

This pilot study will test the implementation of MM and yield first results of the MM and AE in our centres.

Methods:

31 out of 34 patients suffering from BC and CRF were fully assessed in a ten-week intervention study. 21 patients chose MM and 10 decided on AT. CRF was measured with the help of the Cancer Fatigue Scale (CFS-D), and the global quality of sleep was measured with the Pittsburgh Sleep Quality Index (PSQI). We also captured autonomic regulation (aR) and patients’ satisfaction with questionnaires. Statistical analysis was done with SAS 9.1.3 for windows.

Results:

The new MM therapy can be implemented with high satisfaction among patients. Significant improvements were found in the MM group with regards to CFS-D, global quality of sleep, sleep efficiency (PSQI), aR and rest/activity regulation compared to baseline (all p<0.05). In the AT group aR orthostatic-circulatory and rest/activity regulation improved significantly (p<0.05), too. However, no improvement in cognitive fatigue was seen in either group.

Conclusion:

The multimodal therapy concept was feasible and improved cancer fatigue, sleep quality, autonomic and rest-/activity regulation in breast cancer patients. It may therefore constitute a valuable treatment option in addition to aerobic training for BC patients with CRF. A further study with larger sample size needs to be carried out to assess the efficacy of combined multimodal-aerobic therapy.
Immersive Simulated Learning Environments for Researching Critical Incidents
Authors: Alison Laurence , van den Heuvel Claudia , Waring Sara , Power Nicola , Long Amy , O’Hara Terence , Crego Jonathan
Published: December 2012

This article provides an integration and synthesis of the strengths and weaknesses of utilizing simulation-based training environments for research. It provides information for researchers interested in exploring complex, dynamic, and high-stakes decision making in critical incidents. The article proposes that immersive simulated learning environments (ISLEs) are an effective naturalistic decision making tool for examining strategic and tactical multiteam decision making. Specifically, they are useful for researching environments whereby decision characteristics of anticipation, preparation, mitigation, adaptation, and coping are treated as interconnected elements. The article presents the simulation tool Hydra as an example of an ISLE by describing a worked example known as Operation Pandora. It demonstrates how the use of ISLEs can assist research on expert, high-stakes, and high-consequence critical incident decisions.
How Can Collaboration Assist School Leaders in Effectively Implementing New Programs?
Authors: Guesno Erin
Published: December 2012

Elementary school students at a suburban K-12 charter school are facing a difficult transition into the secondary program. In an effort to ease this transition and retain students, the principal requires the secondary teachers to implement a study skills program into the daily curriculum. Initially, the teachers do not voice any objections to the principal, but as the workload increases, their frustration is communicated in a staff meeting. Moreover, students have displayed a negative attitude toward the program. The principal understands that he must diffuse the resentment of the teachers and gain student support to preserve the positive culture of the school.
Principal Pressure in the Middle of Accountability
Authors: Derrington Mary Lynne , Larsen Donald E.
Published: December 2012

When a new superintendent is hired, Tom Thompson, middle school principal, is squeezed between complying with the demands of the district and cultivating a positive culture in his school. He wrestles with the stress of facing tough leadership choices that take a toll on his physical and mental health. Tom realizes that a career-ending move might result from a miscalculation of available options. This case discusses the role of the principal in the district hierarchy, the impact on school staff resulting from punitive district personnel policies, the development of relationships with a new supervisor, and the ethics of test administration underlying administrative decision making.
Tangled Narratives and Wicked Problems
Authors: Nguyen Thu Suong Thi , Scribner Samantha M. Paredes , Crow Gary M.
Published: December 2012

The case of Allen Elementary School presents tangled narratives and wicked problems describing the multidimensionality of school community work. Using multiple converging and diverging vignettes, the case points to the distinctiveness of individual experience in schools; the ways institutionalized organizational narratives become cultural resources for framing, scripting, and revising problems as plots; and the interdependence of micro- and macro processes. Drawing from work on organizational narratives, situated problems, and politics, the case asks students to consider (a) the improvisational character of organizational narratives authored by leaders for particular publics with particular interests, (b) the social and cultural construction of leadership, and (c) how organizational narratives and the construction of leadership play into public engagement by enlarging/diminishing scope of conflict.
Responding to Fiscal Tensions and a Changing Educational Context
Authors: Willmott Kristen E. , Wall Andrew F.
Published: December 2012

This case explores various entrepreneurial initiatives introduced by Dr. Ron Dow, dean of libraries, at a private, research-extensive institution in the northeastern United States. The case serves as an example of how entrepreneurial ideas can be applied within educational contexts, specifically, the academic support context of the university library. The accompanying teaching notes facilitate analysis of the potential and limits of entrepreneurial practice for educational leaders who operate within the ever-changing fiscal landscape of academe.
“Why Do They Hate Us?”
Authors: Karpinski Carol F.
Published: December 2012

Laura Dannon, an educator with experience as teacher, assistant principal, and principal, enjoys her profession. Faculty camaraderie and student/teacher busyness at her school have led her to think all is well. A sudden outburst by a new teacher causes her to reflect on what is really happening. What has changed? Have media criticism, movements against education, attacks on teacher unions, criticisms of college education teacher preparation programs, and a severe economic downturn created an environment in which she needs to rethink her priorities? How does one lead amid criticism, crisis, and disrespect? How can one be a successful leader at the micro level when the broader narrative is dominated by negativism and perceptions of failure?
The “New” Section 504
Authors: Hardcastle Lisa A. , Zirkel Perry A.
Published: December 2012

School leaders are familiar with the Individuals With Disabilities Education Act, but they also need to be legally literate about Section 504 of the Rehabilitation Act. This need is particularly pressing in the wake of significant recent changes in Section 504 as a result of the Americans With Disabilities Amendments Act. This case illustrates the eligibility and entitlement of a student with attention deficit hyperactivity disorder under Section 504 before and after these amendments. Would you be able to take the legally correct course of action if you were Amy Davidson? Do you have legally current and defensible answers to the discussion questions?
Carnegie Units and High School Attendance Policies
Authors: Outhouse Craig Michael
Published: December 2012

This case was developed as part of a doctoral course for educational administration students who were specializing in K-12 educational administration. It could be used in a leadership, special education, or policy course for future school leaders or teachers. Currently, most educational institutions use Carnegie Units to structure how students earn credit throughout the year. In addition, many schools have an attendance policy delineating specific guidelines that students must meet to earn credit. Recently, two high school seniors had their graduation jeopardized due to issues with Carnegie Units and a district’s attendance policy. Drawing from the case of Matthew and Jerry, this article will explore attendance policies and the usage of Carnegie Units.
Why Do Standardized Tests Underpredict Women’s Academic Performance? The Role of Conscientiousness
Authors: Kling Kristen C. , Noftle Erik E. , Robins Richard W.
Published: December 2012

Women typically earn higher grades than men, even though they tend to score lower than men on the SAT, a pattern known as the female underprediction effect (FUE). In three samples, we tested our hypothesis that gender differences in Conscientiousness can explain this effect. Within each sample, we created a regression-based measure of under (vs. over) prediction, which reflects the extent to which an individual student’s actual grade point average (GPA) exceeded (or fell below) the GPA predicted by his or her SAT score. Significant gender differences in this measure documented the presence of the FUE. Next, we demonstrated that Conscientiousness significantly mediated the link between gender and underprediction. Specifically, women were higher in Conscientiousness, and students who were more conscientious earned grades that were higher than their SAT scores would predict. Thus, our expectation that Conscientiousness is a partial explanation for the FUE was confirmed.
Familial Self as a Potent Source of Affirmation
Authors: Cai Huajian , Sedikides Constantine , Jiang Lixin
Published: December 2012

Does affirmation of familial self have a distinct buffering function compared to affirmation of close other (friend, partner) self or individual self? We addressed this question in an East-Asian culture (China) that places particularly high value on familial self. Familial self-affirmation (compared to other forms of self-affirmation as well as low affirmation) curtailed the mortality salience–induced intolerance to birth-control policy (Experiment 1), reduced female participants’ performance detriments—due to stereotype threat—on mental rotation (Experiment 2), and diminished the disadvantageous influence of negative feedback on further interest in information about one’s weaknesses (Experiment 3). Close other self-affirmation, devoid of family context, was no more potent than individual self-affirmation or low affirmation. The findings underscore the utility of distinguishing among different sources of self-affirmation, highlight the relevance of familial self-affirmation to self-affirmation theory, and call for research testing the germaneness of familial self (and, more generally, the construct of family) in other Eastern, as well as Western, cultures.
Does Posting Facebook Status Updates Increase or Decrease Loneliness? An Online Social Networking Experiment
Authors: Deters Fenne große , Mehl Matthias R.
Published: December 2012

Online social networking is a pervasive but empirically understudied phenomenon. Strong public opinions on its consequences exist but are backed up by little empirical evidence and almost no causally conclusive, experimental research. The current study tested the psychological effects of posting status updates on Facebook using an experimental design. For 1 week, participants in the experimental condition were asked to post more than they usually do, whereas participants in the control condition received no instructions. Participants added a lab “Research Profile” as a Facebook friend allowing for the objective documentation of protocol compliance, participants’ status updates, and friends’ responses. Results revealed (1) that the experimentally induced increase in status updating activity reduced loneliness, (2) that the decrease in loneliness was due to participants feeling more connected to their friends on a daily basis, and (3) that the effect of posting on loneliness was independent of direct social feedback (i.e., responses) by friends.
The Psychological Benefits of Income are Contingent on Individual-Level and Culture-Level Religiosity
Authors: Gebauer Jochen E. , Nehrlich Andreas D. , Sedikides Constantine , Neberich Wiebke
Published: December 2012

Higher income is related to better psychological adjustment. We propose that religiosity attenuates this relation. First, in comforting the poor, religious teachings de-emphasize the importance of money, which would buffer low-income's psychological harms (religiosity as poverty buffer account). Second, religious teachings convey antiwealth norms, which would reduce income's psychological benefits (religiosity as antiwealth norms account). A study involving 187,957 respondents from 11 religiously diverse cultures showed that individual-level, as well as culture-level, religiosity weakens the relation between personal income and psychological adjustment in accordance with the religiosity as antiwealth norms account. Performance self-esteem mediated this relation. Religiosity's moderating effects were so pervasive that religious individuals in religious cultures reported better psychological adjustment when their income was low than high.
Facial Stereotype Visualization Through Image Averaging
Authors: Oldmeadow Julian A. , Sutherland Clare A. M. , Young Andrew W.
Published: December 2012

Facial stereotypes are cognitive representations of the facial characteristics of members of social groups. In this study, we examined the extent to which facial stereotypes for occupational groups were based on physiognomic cues to stereotypical social characteristics. In Experiment 1, participants rated the occupational stereotypicality of naturalistic face images. These ratings were then regressed onto independent ratings of the faces on 16 separate traits. These traits, particularly those relevant to the occupational stereotype, explained the majority of variance in occupational stereotypicality ratings. In Experiments 2 and 3, we used trait ratings to reconstruct stereotypical occupation faces from a separate set of images, using face averaging techniques. These reconstructed facial stereotypes were validated by separate groups of participants as conforming to the occupational stereotype. These results indicate that facial cues and group stereotypes are integrated through shared semantic content in the cognitive representations of groups.
Lithium: the pharmacodynamic actions of the amazing ion
Authors: Brown Kayleigh M. , Tracy Derek K.
Published: December 2012

Lithium has been used for the treatment of mood disorders for over 60 years, yet the exact mechanisms by which it exerts its therapeutic effects remain unclear. Two enzymatic chains or pathways emerge as targets for lithium: inositol monophosphatase within the phosphatidylinositol signalling pathway and the protein kinase glycogen synthase kinase 3. Lithium inhibits these enzymes through displacing the normal cofactor magnesium, a vital regulator of numerous signalling pathways. Here we provide an overview of evidence, supporting a role for the inhibition of glycogen synthase kinase 3 and inositol monophosphatase in the pharmacodynamic actions of lithium. We also explore how inhibition of these enzymes by lithium can lead to downstream effects of clinical relevance, both for mood disorders and neurodegenerative diseases. Establishing a better understanding of lithium’s mechanisms of action may allow the development of more effective and more tolerable pharmacological agents for the treatment of a range of mental illnesses, and provide clearer insight into the pathophysiology of such disorders.
Gene-expression signatures differ between different clinical forms of familial hemophagocytic lymphohistiocytosis
Authors: Sumegi Janos , Nestheide Shawnagay V. , Barnes Michael G. , Villanueva Joyce , Zhang Kejian , Grom Alexei A. , Filipovich Alexandra H.
Published: December 2012

Key Points

Distinct gene expression signatures are associated with genetic and clinical subtypes of hemophagocytic lymphohistiocytosis.
Antiviral effects of autologous CD4 T cells genetically modified with a conditionally replicating lentiviral vector expressing long antisense to HIV
Authors: Tebas Pablo , Stein David , Binder-Scholl Gwendolyn , Mukherjee Rithun , Brady Troy , Rebello Tessio , Humeau Laurent , Kalos Michael , Papasavvas Emmanouil , Montaner Luis J. , Schullery Daniel , Shaheen Farida , Brennan Andrea L. , Zheng Zhaohui , Cotte Julio , Slepushkin Vladimir , Veloso Elizabeth , Mackley Adonna , Hwang Wei-Ting , Aberra Faten , Zhan Jenny , Boyer Jean , Collman Ronald G. , Bushman Frederic D. , Levine Bruce L. , June Carl H.
Published: December 2012

Key Points

Adoptive transfer of autologous lentiviral-engineered T cells expressing an antisense is safe in chronic HIV infection. Conditionally replicating lentiviral vector was associated with antiviral effects in patients as assessed by viral evolution and viral load.
Evidence for the interaction of fibroblast growth factor-2 with the lymphatic endothelial cell marker LYVE-1
Authors: Platonova Natalia , Miquel Geraldine , Regenfuss Birgit , Taouji Said , Cursiefen Claus , Chevet Eric , Bikfalvi Andreas
Published: December 2012

Key Points

FGF2 is able to directly interact with LYVE-1 and glycosylation of LYVE-1 is important for the interaction with FGF2. LYVE-1 inhibits FGF2-dependent lymphangiogenesis and FGF2 modulates LYVE-1's endogenous expression and reverses the effect of TNFβ.
Defining bacterial species in the genomic era: insights from the genus Acinetobacter
Authors: Chan Jacqueline Z-M , Halachev Mihail R , Loman Nicholas J , Constantinidou Chrystala , Pallen Mark J
Published: December 2012

Background

Microbial taxonomy remains a conservative discipline, relying on phenotypic information derived from growth in pure culture and techniques that are time-consuming and difficult to standardize, particularly when compared to the ease of modern high-throughput genome sequencing. Here, drawing on the genus Acinetobacter as a test case, we examine whether bacterial taxonomy could abandon phenotypic approaches and DNA-DNA hybridization and, instead, rely exclusively on analyses of genome sequence data.

Results

In pursuit of this goal, we generated a set of thirteen new draft genome sequences, representing ten species, combined them with other publically available genome sequences and analyzed these 38 strains belonging to the genus. We found that analyses based on 16S rRNA gene sequences were not capable of delineating accepted species. However, a core genome phylogenetic tree proved consistent with the currently accepted taxonomy of the genus, while also identifying three misclassifications of strains in collections or databases. Among rapid distance-based methods, we found average-nucleotide identity (ANI) analyses delivered results consistent with traditional and phylogenetic classifications, whereas gene content based approaches appear to be too strongly influenced by the effects of horizontal gene transfer to agree with previously accepted species.

Conclusion

We believe a combination of core genome phylogenetic analysis and ANI provides an appropriate method for bacterial species delineation, whereby bacterial species are defined as monophyletic groups of isolates with genomes that exhibit at least 95% pair-wise ANI. The proposed method is backwards compatible; it provides a scalable and uniform approach that works for both culturable and non-culturable species; is faster and cheaper than traditional taxonomic methods; is easily replicable and transferable among research institutions; and lastly, falls in line with Darwin’s vision of classification becoming, as far as is possible, genealogical.
Application of protein purification methods for the enrichment of a cytotoxin from Campylobacter jejuni
Authors: Gatsos Xenia , Steer David L , Junaid Thamradeen A , Smith A Ian , Adler Ben , Albert M John
Published: December 2012

Background

Campylobater jejuni, a major foodborne diarrhoeal pathogen is reported to produce a number of cytotoxins of which only a cytolethal distending toxin (CDT) has been characterised so far. One or more additional cytotoxins other than CDT, including a Chinese hamster ovary (CHO) cell active, Vero cell inactive cytotoxin, may mediate inflammatory diarrhoea. Our objective was to develop a method to enrich and thus partially characterise this cytotoxin, as a pathway to the eventual identification and characterisation of the toxin.

Results

A number of biochemical methods including cation- and anion-exchange chromatography were evaluated to enrich the cytotoxin from a cell lysate of a known cytotoxin-producing C. jejuni, C31. The cytotoxin in crude lysate was initially prepared by size-exclusion desalting and then subjected to high pressure liquid chromatography (HPLC) ion-exchange fractionation. One pooled fraction (pool B) was cytotoxic for CHO cells equivalent to crude toxin (tissue culture infectivity dose 50 [TCID50] of 1–2 μg/ml). The proteins of pool B were identified by mass spectrometry (MS) after separation by SDS-PAGE and trypsin digestion. Also, pool B was directly digested with trypsin and then subjected to liquid chromatography tandem mass spectrometry (LCMS) analysis for identification of lesser abundant proteins in the fraction. A total of 41 proteins were found in the fraction, which included enzymes involved in metabolic and transport functions. Eighteen non-cytoplasmic proteins including 2 major antigenic peptide proteins (PEB2 and PEB3) and 3 proteins of unknown function were also identified in the screen. Cytotoxicity in pool B was trypsin-sensitive indicating its protein nature. The cytotoxic activity was heat-stable to 50°C, and partially inactivated at 60-70°C. The pool B fraction also induced fluid accumulation in the adult rabbit ileal loop assay with cytotoxicity for mucosa confirming the presence of the cytotoxin.

Conclusions

We report the enrichment and partial purification of C. jejuni cytotoxin by HPLC ion-exchange chromatography. Further purification may be achieved using additional complementary chromatographic techniques. A short-list of six candidate cytotoxin proteins was identified using an LCMS screen of pool B. Successful isolation of the cytotoxin will initiate steps for the determination of the role of this cytotoxin in the pathogenesis of C. jejuni diarrhoea.
Ciprofloxacin-resistant Escherichia coli in Central Greece: mechanisms of resistance and molecular identification
Authors: Mavroidi Angeliki , Miriagou Vivi , Liakopoulos Apostolos , Tzelepi Εva , Stefos Angelos , Dalekos George N , Petinaki Efthymia
Published: December 2012

Background

Fluoroquinolone resistant E. coli isolates, that are also resistant to other classes of antibiotics, is a significant challenge to antibiotic treatment and infection control policies. In Central Greece a significant increase of ciprofloxacin-resistant Escherichia coli has occurred during 2011, indicating the need for further analysis.

Methods

A total of 106 ciprofloxacin-resistant out of 505 E. coli isolates consecutively collected during an eight months period in a tertiary Greek hospital of Central Greece were studied. Antimicrobial susceptibility patterns and mechanisms of resistance to quinolones were assessed, whereas selected isolates were further characterized by multilocus sequence typing and β-lactamase content.

Results

Sequence analysis of the quinolone-resistance determining region of the gyrA and parC genes has revealed that 63% of the ciprofloxacin-resistant E. coli harbored a distinct amino acid substitution pattern (GyrA:S83L + D87N; ParC:S80I + E84V), while 34% and 3% carried the patterns GyrA:S83L + D87N; ParC:S80I and GyrA:S83L + D87N; ParC:S80I + E84G respectively. The aac (6’)-1b-cr plasmid-mediated quinolone resistance determinant was also detected; none of the isolates was found to carry the qnrA, qnrB and qnrS.

Genotyping of a subset of 35 selected ciprofloxacin-resistant E. coli by multilocus sequence typing has revealed the presence of nine sequence types; ST131 and ST410 were the most prevalent and were exclusively correlated with hospital and health care associated infections, while strains belonging to STs 393, 361 and 162 were associated with community acquired infections. The GyrA:S83L + D87N; ParC:S80I + E84V substitution pattern was found exclusively among ST131 ciprofloxacin-resistant E. coli. Extended-spectrum β-lactamase-positive ST131 ciprofloxacin-resistant isolates produced CTX-M-type enzymes; eight the CTX-M-15 and one the CTX-M-3 variant. CTX-M-1 like and KPC-2 enzymes were detected in five and four ST410 ciprofloxacin-resistant E. coli isolates, respectively.

Conclusions

Our findings suggest that, ST131 and ST410 predominate in the ciprofloxacin resistant E. coli population.
Genetic diversity of Mycobacterium tuberculosis isolates from Beijing, China assessed by Spoligotyping, LSPs and VNTR profiles
Authors: Lu Bing , Zhao Ping , Liu Binbin , Dong Haiyan , Yu Qin , Zhao Xiuqin , Wan Kanglin
Published: December 2012

Background

Tuberculosis is one of the most infectious diseases in the world. Molecular typing methods such as spoligotyping, and VNTR (variable number tandem repeats), IS6110 in the NTF region and LSP (large sequence polymorphisms) analysis are generally useful tools for the resolution of various issues related to the classical epidemiology of Mycobacterium tuberculosis (M. tuberculosis).

Methods

To determine the transmission characteristics of M. tuberculosis strains isolated in Beijing, China, and their genetic relationships, especially those among Beijing family strains, 260 M. tuberculosis strains isolated from patients presenting pulmonary tuberculosis were analyzed by spoligotyping, and by examining 22 VNTR loci and the presence/absence of IS6110 in the NTF region, RD105 and RD181.

Results

81% (211 strains) of the isolates studied were Beijing family strains, 174 (82.5%) of which were identified as modern Beijing strains based on the presence of IS6110 upstream of the NTF region. RD181 was intact in 9 of the other 37 (17.5%) ancestral Beijing strains. The percentage of Beijing family strains in this study was consistent with previous reports. There are many differences, however, in allele diversity among VNTR loci between reports on strains from different areas.

Conclusions

The Beijing family is the most prevalent genotype in Beijing city and the predominance of Beijing family strains has not altered in almost twenty years. Differences in the alleles and discrimination ability of VNTR loci between different regions is likely due to population differences in the regions where these M. tuberculosis strains were isolated or to differences in sampling times.
Epidemic of Klebsiella pneumoniae ST11 Clone Coproducing KPC-2 and 16S rRNA Methylase RmtB in a Chinese University Hospital
Authors: Li Jun-Jie , Sheng Zi-Ke , Deng Mei , Bi Sheng , Hu Fei-Shu , Miao Hai-Feng , Ji Zhong-Kang , Sheng Ji-Fang , Li Lan-Juan
Published: December 2012

Background

Emergence of rmtB-positive Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) poses a great threat to antimicrobial treatment options.

Methods

From January 2010 to December 2010, non-duplicate KPC-KP isolates from our hospital were screened for rmtB and multiple other resistance determinants with PCR. Subsequent studies included MIC determination, PFGE, and multilocus sequence typing. Records from patients with KPC-KP isolated were retrospectively reviewed. Comparisons of molecular and clinical characteristics between rmtB-positive and rmtB–negative isolates were systematically performed, as well as the environmental colonization study in ICU wards.

Results

A total of 84 KPC-KP strains were collected, including 48 rmtB-positive KPC-KP (RPKP) and 36 rmtB-negative KPC-KP (RNKP) isolates. All KPC-KP isolates were multidrug resistant, with colistin and tigecycline being the most active agents. Compared with RNKP, RPKP displayed a much severer resistance phenotype. Susceptibility rates for amikacin (0% for RPKP versus 88.9% for RNKP, p < 0.01), fosfomycin (8.5% for RPKP versus 88.9% for RNKP, p < 0.01), and minocycline (6.7% for RPKP versus 52.8% for RNKP, p < 0.01), were all significantly lower in RPKP strains. Isolates belonging to PFGE pulsetype A and sequence type 11 were predominant in both groups, including 39 (81.3%) RPKP and 22 (61.1%) RNKP isolates. Nevertheless, RNKP showed more complex genetic backgrounds compared with RPKP. Diverse clinical characteristics were found in both cohorts, however, no significant differences were observed between RPKP and RNKP patients.

Conclusions

RPKP strains have spread widely and gradually replaced RNKP in our hospital. They seemed to show much severer resistance phenotypes compared with RNKP and had a bigger dissemination potential. Prudent use of available active agents combined with good control practices is therefore mandatory.
An automated method for analysis of microcirculation videos for accurate assessment of tissue perfusion
Authors: Demir Sumeyra U , Hakimzadeh Roya , Hargraves Rosalyn Hobson , Ward Kevin R , Myer Eric V , Najarian Kayvan
Published: December 2012

Background

Imaging of the human microcirculation in real-time has the potential to detect injuries and illnesses that disturb the microcirculation at earlier stages and may improve the efficacy of resuscitation. Despite advanced imaging techniques to monitor the microcirculation, there are currently no tools for the near real-time analysis of the videos produced by these imaging systems. An automated system tool that can extract microvasculature information and monitor changes in tissue perfusion quantitatively might be invaluable as a diagnostic and therapeutic endpoint for resuscitation.

Methods

The experimental algorithm automatically extracts microvascular network and quantitatively measures changes in the microcirculation. There are two main parts in the algorithm: video processing and vessel segmentation. Microcirculatory videos are first stabilized in a video processing step to remove motion artifacts. In the vessel segmentation process, the microvascular network is extracted using multiple level thresholding and pixel verification techniques. Threshold levels are selected using histogram information of a set of training video recordings. Pixel-by-pixel differences are calculated throughout the frames to identify active blood vessels and capillaries with flow.

Results

Sublingual microcirculatory videos are recorded from anesthetized swine at baseline and during hemorrhage using a hand-held Side-stream Dark Field (SDF) imaging device to track changes in the microvasculature during hemorrhage. Automatically segmented vessels in the recordings are analyzed visually and the functional capillary density (FCD) values calculated by the algorithm are compared for both health baseline and hemorrhagic conditions. These results were compared to independently made FCD measurements using a well-known semi-automated method. Results of the fully automated algorithm demonstrated a significant decrease of FCD values. Similar, but more variable FCD values were calculated using a commercially available software program requiring manual editing.

Conclusions

An entirely automated system for analyzing microcirculation videos to reduce human interaction and computation time is developed. The algorithm successfully stabilizes video recordings, segments blood vessels, identifies vessels without flow and calculates FCD in a fully automated process. The automated process provides an equal or better separation between healthy and hemorrhagic FCD values compared to currently available semi-automatic techniques. The proposed method shows promise for the quantitative measurement of changes occurring in microcirculation during injury.
Positive genetic interactors of HMG2 identify a new set of genetic perturbations for improving sesquiterpene production in Saccharomyces cerevisiae
Authors: Ignea Codruta , Trikka Fotini A , Kourtzelis Ioannis , Argiriou Anagnostis , Kanellis Angelos K , Kampranis Sotirios C , Makris Antonios M
Published: December 2012

Background

Terpenoids and isoprenoids are an important class of natural products, which includes currently used drugs, high value bioactive and industrial compounds, and fuel candidates. Due to their industrial application, there is increasing interest in the development of S. cerevisiae strains capable of producing high levels of terpenoids.

Results

Aiming to identify new gene targets which can be manipulated to increase sesquiterpene production, a set of HMG2 positive genetic interactors were assessed as single and digenic heterozygous deletions in the presence or absence of stable HMG2(K6R) overexpression. Upon single allele deletion, most genes examined led to increased sesquiterpene production in yeast cells. Tandem heterozygous deletion of a set of three genes, the ubiquitin ligases ubc7 and ssm4/doa10, and the ER resident protein pho86, led to an 11-fold increase in caryophyllene yields (125 mg/L in shake flasks) compared to cells lacking these modifications. The effect of the heterozygous deletions appears to be due to Hmg1p and Hmg2p stabilization.

Conclusion

Heterozygous deletions cause significant reductions in protein levels but do not lead to growth impediments frequently seen in haploid strains. By exploiting desirable haploinsufficiencies in yeast, we identified a new set of genes that can be disrupted in tandem and cause significant stabilization of Hmgp and a substantial increase in sesquiterpene production. The approach presented here allows new genetic perturbations to be compiled on yeast cell factory strains without negatively impacting cell growth and viability.
Degradation of a textile reactive azo dye by a combined biological-photocatalytic process: Candida tropicalis Jks2 -Tio2/Uv
Authors: Jafari Narjes , Kasra-Kermanshahi Rouha , Soudi Mohammad Reza , Mahvi Amir Hossein , Gharavi Sara
Published: December 2012

In the present study, the decolorization and degradation of Reactive Black 5 (RB5) azo dye was investigated by biological, photocatalytic (UV/TiO2) and combined processes. Application of Candida tropicalis JKS2 in treatment of the synthetic medium containing RB5 indicated complete decolorization of the dye with 200 mg/L in less than 24 h. Degradation of the aromatic rings, resulting from the destruction of the dye, did not occur during the biological treatment. Mineralization of 50 mg/L RB5 solution was obtained after 80 min by photocatalytic process (in presence of 0.2 g/L TiO2). COD (chemical oxygen demand) was not detectable after complete decolorization of 50 mg/L RB5 solution. However, photocatalytic process was not effective in the removal of the dye at high concentrations (≥200 mg/L). With 200 mg/L concentration, 74.9% of decolorization was achieved after 4 h illumination under photocatalytic process and the absorbance peak in UV region (attributed to aromatic rings) was not completely removed. A two-step treatment process, namely, biological treatment by yeast followed by photocatalytic degradation, was also assessed. In the combined process (with 200 mg/L RB5), absorbance peak in UV region significantly disappeared after 2 h illumination and about 60% COD removal was achieved in the biological step. It is suggested that the combined process is more effective than the biological and photocatalytic treatments in the remediation of aromatic rings.
L-glutamate released from activated microglia downregulates astrocytic L-glutamate transporter expression in neuroinflammation: the ‘collusion’ hypothesis for increased extracellular L-glutamate concentration in neuroinflammation
Authors: Takaki Junpei , Fujimori Koki , Miura Marie , Suzuki Takeshi , Sekino Yuko , Sato Kaoru
Published: December 2012

Background

In the central nervous system, astrocytic L-glutamate (L-Glu) transporters maintain extracellular L-Glu below neurotoxic levels, but their function is impaired with neuroinflammation. Microglia become activated with inflammation; however, the correlation between activated microglia and the impairment of L-Glu transporters is unknown.

Methods

We used a mixed culture composed of astrocytes, microglia, and neurons. To quantify L-Glu transporter function, we measured the extracellular L-Glu that remained 30 min after an application of L-Glu to the medium (the starting concentration was 100 μM). We determined the optimal conditions of lipopolysaccharide (LPS) treatment to establish an inflammation model without cell death. We examined the predominant subtypes of L-Glu transporters and the changes in the expression levels of these transporters in this inflammation model. We then investigated the role of activated microglia in the changes in L-Glu transporter expression and the underlying mechanisms in this inflammation model.

Results

Because LPS (10 ng/mL, 72 h) caused a significant increase in the levels of L-Glu remaining but did not affect cell viability, we adopted this condition for our inflammation model without cell death. GLAST was the predominant L-Glu transporter subtype, and its expression decreased in this inflammation model. As a result of their release of L-Glu, activated microglia were shown to be essential for the significant decrease in L-Glu uptake. The serial application of L-Glu caused a significant decrease in L-Glu uptake and GLAST expression in the astrocyte culture. The hemichannel inhibitor carbenoxolone (CBX) inhibited L-Glu release from activated microglia and ameliorated the decrease in GLAST expression in the inflammation model. In addition, the elevation of the astrocytic intracellular L-Glu itself caused the downregulation of GLAST.

Conclusions

Our findings suggest that activated microglia trigger the elevation of extracellular L-Glu through their own release of L-Glu, and astrocyte L-Glu transporters are downregulated as a result of the elevation of astrocytic intracellular L-Glu levels, causing a further increase of extracellular L-Glu. Our data suggest the new hypothesis that activated microglia collude with astrocytes to cause the elevation of extracellular L-Glu in the early stages of neuroinflammation.
ERCC1 mRNA levels can predict the response to cisplatin-based concurrent chemoradiotherapy of locally advanced cervical squamous cell carcinoma
Authors: Bai Zhou-lan , Wang Yan-yang , Zhe Hong , He Jian-li , Hai Ping
Published: December 2012

Background

The purpose of this study was to investigate whether the excision repair cross-complementation group 1 (ERCC1) mRNA expression could predict treatment response of patients with locally advanced cervical squamous cell carcinoma (LACSCC) who underwent cisplatin-based concurrent chemoradiotherapy (CCCRT).

Methods

A total of sixty LACSCC patients, treated with radical CCCRT from a single institution were evaluated. ERCC1 mRNA expression was determined by quantitative real-time RT-PCR in pre-treatment tumor tissues. The association of ERCC1 status with clinicopathological characteristics (age, histological grade, tumor size, parametrial invasion, lymph node metastasis and FIGO stage) and treatment response were analyzed.

Results

No significant association between ERCC1 mRNA expression and clinicopathological characteristics were observed. Patients with low ERCC1 mRNA level had a significantly higher rate of complete response (86.21%) than patients with high level of ERCC1 expression (19.36%; p < 0.001). In the logistic regression analysis, low ERCC1 mRNA level retained an independent role in predicting complete response to CCCRT (P < 0.001). An ERCC1 expression level of 0.0901 was determined as an optimal cutoff value to identify complete response patients to CCCRT treatment. The sensitivity for detection of a complete response was 81.48% with a specificity of 96.97% (area under the curve, 0.893; 95% confidence interval, 0.804–0.983).

Conclusions

This is the first analysis of the association between ERCC1 mRNA levels and treatment response in patients with LACSCC. Low ERCC1 mRNA level appears to be a highly specific predictor of response to CCCRT in LACSCC.