bluuebunny/crossref_metadata_2025 huggingface dataset:
Porphyromonas gingivalis displays a competitive advantage over Aggregatibacter actinomycetemcomitans in co‐cultured biofilm
Authors: Takasaki K. , Fujise O. , Miura M. , Hamachi T. , Maeda K.
Published: October 2012

Background and Objective

Biofilm formation occurs through the events of cooperative growth and competitive survival among multiple species. Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans are important periodontal pathogens. The aim of this study was to demonstrate competitive or cooperative interactions between these two species in co‐cultured biofilm.

Material and Methods

P. gingivalis strains and gingipain mutants were cultured with or without A. actinomycetemcomitans. Biofilms formed on glass surfaces were analyzed by crystal violet staining and colony counting. Preformed A. actinomycetemcomitans biofilms were treated with P. gingivalis culture supernatants. Growth and proteolytic activities of gingipains were also determined.

Results

Monocultured P. gingivalis strains exhibited a range of biofilm‐formation abilities and proteolytic activities. The ATCC33277 strain, noted for its high biofilm‐formation ability and proteolytic activity, was found to be dominant in biofilm co‐cultured with A. actinomycetemcomitans. In a time‐resolved assay, A. actinomycetemcomitans was primarily the dominant colonizer on a glass surface and subsequently detached in the presence of increasing numbers of ATCC33277. Detachment of preformed A. actinomycetemcomitans biofilm was observed by incubation with culture supernatants from highly proteolytic strains.

Conclusion

These results suggest that P. gingivalis possesses a competitive advantage over A. actinomycetemcomitans. As the required biofilm‐formation abilities and proteolytic activities vary among P. gingivalis strains, the diversity of the competitive advantage is likely to affect disease recurrence during periodontal maintenance.
Transformational leadership in nursing: towards a more critical interpretation
Authors: Hutchinson Marie , Jackson Debra
Published: October 2012

HUTCHINSON M and JACKSON D. Nursing Inquiry 2013; 20: 11–22  Transformational leadership in nursing: towards a more critical interpretation

Effective nurse leadership is positioned as an essential factor in achieving optimal patient outcomes and workplace enhancement. Over the last two decades, writing and research on nursing leadership has been dominated by one conceptual theory, that of transformational leadership. This theoretical framework has provided insight into various leader characteristics, with research findings presented as persuasive evidence. While elsewhere there has been robust debate on the merits of the transformational model of leadership, in the nursing literature, there has been little critical review of the model and the commonly used assessment instruments. In this article, we critically review more than a decade of nursing scholarship on the transformational model of leadership and its empirical evidence. Applying a critical lens to the literature, the conceptual and methodological weaknesses of much nursing research on this topic, we question whether the uncritical adoption of the transformational model has resulted in a limited interpretation of nursing leadership. Given the limitations of the model, we advocate embracing new ways of thinking about nursing leadership.
Reduction of Torque-Induced Bending Vibrations in Ball Screw-Driven Machines via Optimal Design of the Nut
Authors: Okwudire Chinedum E.
Published: October 2012

As a result of the push for sustainable machine designs, efforts are constantly being made to reduce the mass/inertia of moving machine components so as to minimize material usage and energy consumption. However, the reduction of structural stiffness that often accompanies such efforts gives rise to unwanted vibrations which must be effectively mitigated to ensure satisfactory performance of the designed machine. The ball screw mechanism (BSM) is commonly used in machines for motion and force transmission. Recent research has shown that, due to the coupling introduced by the nut, a torque applied to the shaft of a ball screw mechanism causes undesirable lateral (bending) vibrations of the screw, which adversely affect the fatigue life and positioning accuracy of ball screw-driven machines. In this paper, an analysis of the stiffness matrix connecting the screw to the nut is used to show that the entry/exit angle of the balls and the lead angle of the screw have the greatest influence on the coupling between the torsional and lateral directions. An objective function is proposed to minimize the static coupling between the applied torque and lateral deformations of the screw. The existence of local minima in the objective function is shown to be dependent on the cyclical characteristics of cross-coupling terms in the screw-nut interface stiffness matrix as a function of the entry/exit angle of the balls. Moreover, the sensitivity of the local minima to other nut/screw parameters is shown to highly depend on the lead angle. Simulations conducted on the finite element (FE) model of a single-axis ball screw-driven machine demonstrate that the optimally selected entry/exit angles result in a significant reduction of the low-frequency torque-induced vibrations of the machine compared to the unoptimized case, particularly when the lead angle is small. The proposed method is therefore suitable for reducing the torque-induced lateral vibrations of ball screws without increasing the diameter (i.e., inertia) of the screw, thus leading to more sustainable designs of ball screw-driven machines.
Error Analysis of the Radiative Power Determined From Flux Distributions Measured With a Camera in a Xe Arc Lamp-Based Solar Simulator
Authors: Alxneit Ivo
Published: October 2012

The CCD camera-based flux measurement at Paul Scherrer Institute's (PSI) high flux solar simulator (HFSS) is influenced by a spatially variable spectrum of the concentrated radiation characteristic for arc lamp-based solar simulators. This results in a substantial error in the radiative power determined by integration of the flux distribution. This systematic error is assessed by numerically modeling the response of the CCD camera in use. Measured spectra of concentrated radiation obtained at different points in the flux distribution, measured transmission characteristics of all optical elements, and published data for the spectral sensitivity of the CCD chip are applied in the model. The response of a water calorimeter is used as baseline case. It is shown that the magnitude of the error depends strongly on the region analyzed, i.e., on aperture size, on the wavelength band analyzed, and, unfortunately, also on the number of lamps in operation. A relative error in the range of 10–30% is observed if an aperture with 1 cm in diameter covering the region of peak concentration is considered. It will be shown that the error arises due to the fact that a photon counter (CCD camera) is used to determine the thermal power.
X-ray photoelectron spectroscopy study on the chemistry involved in tin oxide film growth during chemical vapor deposition processes
Authors: Mannie Gilbère J. A. , Gerritsen Gijsbert , Abbenhuis Hendrikus C. L. , van Deelen Joop , (Hans) Niemantsverdriet J. W. , Thüne Peter C.
Published: October 2012

The chemistry of atmospheric pressure chemical vapor deposition (APCVD) processes is believed to be complex, and detailed reports on reaction mechanisms are scarce. Here, the authors investigated the reaction mechanism of monobutyl tinchloride (MBTC) and water during SnO2 thin film growth using x-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). XPS results indicate an acid–base hydrolysis reaction mechanism, which is tested with multilayer experiments, demonstrating self-terminating growth. In-house developed TEM wafers are used to visualize nucleation during these multilayer experiments, and results are compared with TEM results of APCVD samples. Results show almost identical nucleation behavior implying that their growth mechanism is identical. Our experiments suggest that in APCVD, when using MBTC and water, SnO2 film growth occurs via a heterolytic bond splitting of the Sn-Cl bonds without the need to invoke gas-phase radical or coordination chemistry of the MBTC precursor.
The Science of Resilience: Implications for the Prevention and Treatment of Depression
Authors: Southwick Steven M. , Charney Dennis S.
Published: October 2012

Human responses to stress and trauma vary widely. Some people develop trauma-related psychological disorders, such as posttraumatic stress disorder (PTSD) and depression; others develop mild to moderate psychological symptoms that resolve rapidly; still others report no new psychological symptoms in response to traumatic stress. Individual variability in how animals and humans respond to stress and trauma depends on numerous genetic, developmental, cognitive, psychological, and neurobiological risk and protective factors.
The Efficacy of Student-Centered Instruction in Supporting Science Learning
Authors: Granger E. M. , Bevis T. H. , Saka Y. , Southerland S. A. , Sampson V. , Tate R. L.
Published: October 2012

Puzzling Through Gravity

Much of the excitement of scientific discovery seems to get lost when science is taught as facts by lectures.

Granger
et al.

(p.
105
) present a large study of outcomes comparing inquiry-based teaching with more traditional teaching methods. Over 2000 students were involved, in 125 classrooms of 4th- and 5th-graders. The classes studied space-science with a curriculum that uses models and evidence to entice students into improving their own understanding of the science. Students who were encouraged to use evidence to support their models seemed to develop improved knowledge of content.
A Local Proton Source Enhances CO
2
Electroreduction to CO by a Molecular Fe Catalyst
Authors: Costentin Cyrille , Drouet Samuel , Robert Marc , Savéant Jean-Michel
Published: October 2012

Lending a Hand to CO
2
Reduction

Although plants and microbes have been reducing CO
2
with ease for millennia, people still find it extremely challenging. A cost-effective synthetic scheme for transforming CO
2
into fuels and commodity chemicals would be a double boon, lowering atmospheric concentration of the greenhouse gas while supplementing (and perhaps ultimately replacing) dwindling petroleum feedstocks. Toward this end,

Costentin
et al.

(p.
90
) show that an iron catalyst for the electrochemical reduction of CO
2
to CO gets an efficiency boost from phenol substituents appended to the ligand framework.
Imaging the Homogeneous Nucleation During the Melting of Superheated Colloidal Crystals
Authors: Wang Ziren , Wang Feng , Peng Yi , Zheng Zhongyu , Han Yilong
Published: October 2012

Homogeneous Melting

The nucleation and melting of crystals are primarily driven by surfaces and defects, which can lower the thermodynamic barrier to a phase transition. A harder problem to study is when the transition occurs uniformly.

Wang
et al.

(p.
87
; see the Perspective by

Weeks

) imaged the homogeneous melting of superheated colloidal crystals using a laser to initiate the melting at the interior of the crystal. The authors were then able to track nucleation precursors and nucleus evolution and to find where defects and instabilities limited the homogeneous melting process.
Insect Herbivores Drive Real-Time Ecological and Evolutionary Change in Plant Populations
Authors: Agrawal Anurag A. , Hastings Amy P. , Johnson Marc T. J. , Maron John L. , Salminen Juha-Pekka
Published: October 2012

Plant Anti-Insect Armaments

Because individual plants are unable to relocate, they are subject to extreme selection by the insects feeding upon them. One means by which plants suppress herbivory is to produce toxic compounds to deter feeding (see the Perspective by

Hare

).

Agrawal
et al.

(p.
113
) compared pesticide–treated or untreated evening primroses. Over 5 years of pesticide treatment, the production of defensive chemicals in the fruit reduced and flowering times shifted, and the primrose's competitive ability against dandelions improved.

Züst
et al.

(p.
116
) examined large-scale geographic patterns in a polymorphic chemical defense locus in the model plant
Arabidopsis thaliana
and found that it is matched by changes in the relative abundance of two specialist aphids. Thus, herbivory has strong and immediate effects on the local genotypic composition of plants and traits associated with herbivore resistance.
Network Resets in Medial Prefrontal Cortex Mark the Onset of Behavioral Uncertainty
Authors: Karlsson Mattias P. , Tervo Dougal G. R. , Karpova Alla Y.
Published: October 2012

Changing Your Belief

The ability to display behavioral flexibility depends on an internal representation of the environment—a framework of beliefs that can be adjusted on the basis of experience. Recording from multiple electrodes in the rat medial prefrontal cortex,

Karlsson
et al.

(p.
135
) investigated how ensembles of neurons changed their activity during the performance of a task in which the animal had to update its knowledge of reward contingencies. The results suggest that changes in perceived action-outcome contingencies were associated with abrupt switches in neuronal representations in the rat medial prefrontal cortex.
Theory and Simulation in Neuroscience
Authors: Gerstner Wulfram , Sprekeler Henning , Deco Gustavo
Published: October 2012

Theory Drives Understanding

The role of theory and simulation in neuroscience has been hotly debated over the past few years, in particular in the context of the recent launch of several big projects aimed at creating artificial or virtual brains.

Gerstner
et al.

(p.
60
) review how theory and simulations have interacted over the years and how they have contributed to our present view of how the brain works.
How Insect Herbivores Drive the Evolution of Plants
Authors: Hare J. Daniel
Published: October 2012

The presence or absence of particular herbivore species influences which plant genotypes are favored by natural selection.
Melting Colloidal Crystals from the Inside Out
Authors: Weeks Eric R.
Published: October 2012

How crystals melt can be seen directly by studying size-tunable colloidal particles.
Researchers Struggle to Assess Responses to Ocean Acidification
Authors: Malakoff David
Published: October 2012

Scientists met last week to discuss how to build a better crystal ball to gauge the effects of rising CO
2
emissions on ocean acidity.
'Awesome' Synthesis Could Boost Protein-Based Drugs
Authors: Service Robert F.
Published: October 2012

Synthetic chemists reported last week that for the first time they had synthesized erythropoietin with a uniform coating of sugar chains that decorate the outside of the natural molecule.
How Are Memories Retrieved?
Authors: Miller Greg
Published: October 2012

New work suggests that memory is far more fluid than neuroscientists thought, and that memory retrieval plays a crucial role in shaping memory over time.
Why Is Mental Illness So Hard to Treat?
Authors: Miller Greg
Published: October 2012

The human brain is complex and difficult to study, which has impeded development of drug treatments for mental illnesses. But new tools and new ways of thinking could help the field gain new traction.
Why Are Our Brains So Big?
Authors: Balter Michael
Published: October 2012

The leading hypothesis for why humans have such large brains is that we live in large social groups, which requires considerable processing power. But which came first, the big groups or the big brains?
Why Are You and Your Brain Unique?
Authors: Miller Greg
Published: October 2012

Recent work has provided clues about the neural basis of individual differences in behavior, cognition, and even personality, but there's still much we don't know.
The Oral, Live Attenuated Enterotoxigenic Escherichia coli Vaccine ACE527 Reduces the Incidence and Severity of Diarrhea in a Human Challenge Model of Diarrheal Disease
Authors: Darsley Michael J. , Chakraborty Subhra , DeNearing Barbara , Sack David A. , Feller Andrea , Buchwaldt Charlotte , Bourgeois A. Louis , Walker Richard , Harro Clayton D.
Published: October 2012

An oral, live attenuated, three-strain recombinant bacterial vaccine, ACE527, was demonstrated to generate strong immune responses to colonization factor and toxin antigens of enterotoxigenic
Escherichia coli
(ETEC) in human volunteers. The vaccine was safe and well tolerated at doses of up to 10
11
CFU, administered in each of two doses given 21 days apart. These observations have now been extended in a phase 2b study with a total of 70 subjects. Fifty-six of these subjects were challenged 28 days after the second dose of vaccine with the highly virulent ETEC strain H10407 to obtain preliminary indicators of efficacy against disease and to support further development of the vaccine for both travelers and infants in countries where ETEC is endemic. The vaccine had a significant impact on intestinal colonization by the challenge strain, as measured by quantitative fecal culture 2 days after challenge, demonstrating the induction of a functional immune response to the CFA/I antigen. The incidence and severity of diarrhea were also reduced in vaccinees as measured by a number of secondary and
ad hoc
endpoints, although the 27% reduction seen in the primary endpoint, moderate to severe diarrhea, was not statistically significant. Together, these observations support the hypothesis that the ACE527 vaccine has a dual mode of action, targeting both colonization factors and the heat-labile enterotoxin (LT), and suggest that it should be further developed for more advanced trials to evaluate its impact on the burden of ETEC disease in field settings.
Novel Interpretation of Molecular Diagnosis of Congenital Toxoplasmosis According to Gestational Age at the Time of Maternal Infection
Authors: Sterkers Yvon , Pratlong Francine , Albaba Sahar , Loubersac Julie , Picot Marie-Christine , Pretet Vanessa , Issert Eric , Boulot Pierre , Bastien Patrick
Published: October 2012

From a prospective cohort of 344 women who seroconverted for toxoplasmosis during pregnancy, 344 amniotic fluid, 264 placenta, and 216 cord blood samples were tested for diagnosis of congenital toxoplasmosis using the same PCR assay. The sensitivity and negative predictive value of the PCR assay using amniotic fluid were 86.3% and 97.2%, respectively, and both specificity and positive predictive value were 100%. Using placenta and cord blood, sensitivities were 79.5% and 21.2%, and specificities were 92% and 100%, respectively. In addition, the calculation of pretest and posttest probabilities and the use of logistic regression allowed us to obtain curves that give a dynamic interpretation of the risk of congenital toxoplasmosis according to gestational age at maternal infection, as represented by the three sample types (amniotic fluid, placenta, and cord blood). Two examples are cited here: for a maternal infection at 25 weeks of amenorrhea, a negative result of prenatal diagnosis allowed estimation of the probability of congenital toxoplasmosis at 5% instead of an
a priori
(pretest) risk estimate of 33%. For an infection at 10 weeks of amenorrhea associated with a pretest congenital toxoplasmosis risk of 7%, a positive PCR result using placenta at birth yields a risk increase to 43%, while a negative result damps down the risk to 0.02%. Thus, with a molecular diagnosis performing at a high level, and in spite of the persistence of false negatives, posttest risk curves using both negative and positive results prove highly informative, allowing a better assessment of the actual risk of congenital toxoplasmosis and finally an improved decision guide to treatment.
Direct Detection and Genotyping of Klebsiella pneumoniae Carbapenemases from Urine by Use of a New DNA Microarray Test
Authors: Peter Harald , Berggrav Kathrine , Thomas Peter , Pfeifer Yvonne , Witte Wolfgang , Templeton Kate , Bachmann Till T.
Published: October 2012

Klebsiella pneumoniae
carbapenemases (KPCs) are considered a serious threat to antibiotic therapy, as they confer resistance to carbapenems, which are used to treat extended-spectrum beta-lactamase (ESBL)-producing bacteria. Here, we describe the development and evaluation of a DNA microarray for the detection and genotyping of KPC genes (
bla
KPC
) within a 5-h period. To test the whole assay procedure (DNA extraction plus a DNA microarray assay) directly from clinical specimens, we compared two commercial DNA extraction kits (the QIAprep Spin miniprep kit [Qiagen] and the urine bacterial DNA isolation kit [Norgen]) for the direct DNA extraction from urine samples (dilution series spiked in human urine). Reliable single nucleotide polymorphism (SNP) typing was demonstrated using 1 × 10
5
CFU/ml urine for
Escherichia coli
(Qiagen and Norgen) and 80 CFU/ml urine, on average, for
K. pneumoniae
(Norgen). This study presents, for the first time, the combination of a new KPC microarray with commercial sample preparation for detecting and genotyping microbial pathogens directly from clinical specimens; this paves the way toward tests providing epidemiological and diagnostic data, enabling better antimicrobial stewardship.
Comparative Assessment of a Commercial Kit and Two Laboratory-Developed PCR Assays for Molecular Diagnosis of Congenital Toxoplasmosis
Authors: Morelle Christelle , Varlet-Marie Emmanuelle , Brenier-Pinchart Marie-Pierre , Cassaing Sophie , Pelloux Hervé , Bastien Patrick , Sterkers Yvon
Published: October 2012

Toxoplasmosis is a worldwide infection that may cause severe disease and is regarded as a serious health problem in France. Detection of the parasite by molecular methods is crucial for diagnosing the disease. The extreme diversity of methods and performances of
Toxoplasma
PCR assays makes the use of commercial PCR kits an attractive alternative, as they offer a chance for standardization. We compared the performances of three molecular methods for the detection of
Toxoplasma gondii
DNA in amniotic fluid: a commercial method using nested PCR and two laboratory-developed methods, one using conventional PCR and the other one real-time PCR. This evaluation was based upon a
T. gondii
DNA serial dilution assay, three amniotic fluid samples spiked with
T. gondii
at different concentrations, and a clinical cohort of 33 amniotic fluid samples. The
T. gondii
DNA serial dilution assay showed a much lower sensitivity for the commercial kit than for the laboratory-developed methods. Moreover, out of 12 proven congenital toxoplasmosis cases, 91.7% were detected by the laboratory-developed assays, whereas only 50% were detected by the commercial kit. A lack of sensitivity of the method, partly due to the presence of PCR inhibitors, was the main drawback of the commercial method. This study emphasizes that commercial PCR diagnostic kits do not systematically perform better than carefully optimized laboratory-developed methods. There is a need for thorough evaluation of such kits by proficient groups, as well as for performance standards that commercial kits can be tested against to improve confidence in those selected by health care providers.
Characterization of a Verocytotoxin-Producing Enteroaggregative Escherichia coli Serogroup O111:H21 Strain Associated with a Household Outbreak in Northern Ireland
Authors: Dallman Tim , Smith Geoffrey P. , O'Brien Brendan , Chattaway Marie A. , Finlay David , Grant Kathie A. , Jenkins Claire
Published: October 2012

A strain of
Escherichia coli
O111:H21 recently isolated in the United Kingdom harbored the phage-encoded
vtx2c
gene and the aggregative adherence plasmid. Although exhibiting the same pathogenic profile as the
E. coli
O104:H4 strain linked to the outbreak in Germany, there were important differences in strain characteristics and in the epidemiological setting.
Comparison of Hybrid Capture II, Linear Array, and a Bead-Based Multiplex Genotyping Assay for Detection of Human Papillomavirus in Women with Negative Pap Test Results and Atypical Squamous Cells of Undetermined Significance
Authors: Comar Manola , Iannacone Michelle R. , Casalicchio Giorgia , McKay-Chopin Sandrine , Tommasino Massimo , Gheit Tarik
Published: October 2012

Many methods with different levels of analytical sensitivity and clinical specificity have been developed to detect the presence of high-risk (HR) types of the human papillomavirus (HPV) in cervical samples. The Hybrid Capture II (HC-II) assay is broadly used for primary screening. In addition, several HPV genotyping assays, based on PCR methods, display higher sensitivity than the HC-II and are also used in screening programs. We evaluated the performance of three HPV DNA tests, namely, the HC-II, the Linear Array (LA) HPV genotyping assay, and an HPV type-specific E7 PCR bead-based multiplex genotyping assay (TS-MPG) that is a laboratory-developed method for the detection of HPV, in 94 women with atypical squamous cells of undetermined significance (ASC-US) and in cytological samples from 86 women with a negative Pap test. The HPV prevalence with the TS-MPG assay was increased compared to the prevalence with the LA and HC-II assays. The HPV DNA prevalence in women with ASC-US was greater with the TS-MPG assay (46.2%) than with the LA (36.3%) and HC-II (29.7%) assays. The HPV DNA prevalence in the control group was greater with the TS-MPG assay (32.1%) than with the LA assay (10.7%). Two women with ASC-US who were HPV DNA negative by the HC-II and positive by the TS-MPG or/and LA assays had lesions that progressed to low-grade squamous intraepithelial and high-grade squamous intraepithelial lesions. This study shows that the TS-MPG assay exhibited higher analytical sensitivity than the LA and HC-II assays for the detection of HPV DNA, which reduces the potential to incorrectly identify a woman's HPV infection status.
Unusual “Flesh-Eating” Strains of Escherichia coli
Authors: Shaked Hila , Samra Zmira , Paul Michal , Madar-Shapiro Liora , Cohen Jonathan , Pitlik Silvio , Bishara Jihad
Published: October 2012

Monomicrobial necrotizing fasciitis (type II) is typically caused by group A streptococcus alone or in combination with
Staphylococcus aureus. Escherichia coli
has been isolated from polymicrobial or Fournier's gangrene but has rarely been reported in monomicrobial necrotizing fasciitis. We describe the clinical characteristics and outcomes of seven cases of monomicrobial
E. coli
necrotizing fasciitis and/or severe soft tissue infection diagnosed at a single institution during an 18-month period. Four isolates from three patients and two isolates from two patients with type I polymicrobial severe soft tissue infection (controls) were assayed by the randomly amplified polymorphic DNA (RAPD) analysis for fingerprinting and PCR amplification of primers in order to detect cytotoxic necrotizing factor 1 and 2 (
cnf1
and
cnf2
) genes. All patients had some type of immune suppression. The limb was the most commonly involved organ. In all cases,
E. coli
was isolated as a monomicrobial pathogen from blood, fascia, or both. All patients died during hospitalization, three within the first 48 h. The RAPD amplification assay showed a high degree of genetic diversity among the “flesh-eating” strains and controls. The
cnf1
toxin gene was identified in two out of three cases, but not in the controls.
cnf2
was not detected in any of the patients.
E. coli
may be responsible for life-threatening necrotizing fasciitis. Further research is needed to reveal relevant risk factors, reservoirs, and modes of transmission of
cnf1 E. coli
.
Hexaplex PCR Detection System for Identification of Five Human Plasmodium Species with an Internal Control
Authors: Chew Ching Hoong , Lim Yvonne Ai Lian , Lee Ping Chin , Mahmud Rohela , Chua Kek Heng
Published: October 2012

Malaria remains one of the major killers of humankind and persists to threaten the lives of more than one-third of the world's population. Given that human malaria can now be caused by five species ofPlasmodium, i.e.,Plasmodium falciparum,Plasmodium vivax,Plasmodium malariae,Plasmodium ovale, and the recently includedPlasmodium knowlesi, there is a critical need not only to augment global health efforts in malaria control but also, more importantly, to develop a rapid, accurate, species-sensitive/species-specific, and economically effective diagnostic method for malaria caused by these five species. Therefore, in the present study, a straightforward single-step hexaplex PCR system targeting five humanPlasmodium18S small-subunit rRNAs (ssu rRNAs) was designed, and the system successfully detected all five human malaria parasites. In addition, this system enables the differentiation of single infection as well as mixed infections up to the two-species level. This assay was validated with 50 randomly blinded test and 184 clinical samples suspected to indicate malaria. This hexaplex PCR system is not only an ideal alternative for routine malaria diagnosis in laboratories with conventional PCR machines but also adds value to diagnoses when there is a lack of an experienced microscopist or/and when the parasite morphology is confusing. Indeed, this system will definitely enhance the accuracy and accelerate the speed in the diagnosis of malaria, as well as improve the efficacy of malaria treatment and control, in addition to providing reliable data from epidemiological surveillance studies.
Should Varicella-Zoster Virus Culture Be Eliminated? A Comparison of Direct Immunofluorescence Antigen Detection, Culture, and PCR, with a Historical Review
Authors: Wilson D. A. , Yen-Lieberman B. , Schindler S. , Asamoto K. , Schold J. D. , Procop G. W.
Published: October 2012

A comparison of direct fluorescent-antibody assay (DFA), culture, and two PCR assays disclosed sensitivities of 87.8%, 46.3%, and 97.6% and 100%, respectively. We reviewed 1,150 results for clinical specimens submitted for DFA and culture and found that only 17 were culture positive/DFA negative. The incremental cost to detect these 17 positives was $3,078/specimen.
Discrepancy in patient-rated and oncologist-rated performance status on depression and anxiety in cancer: a prospective study protocol: Table A1
Authors: Mei Hsien Caryn Chan , Wan Azman Wan Azmad , Md Yusof Mastura , Ho Gwo Fuang , Krupat Edward
Published: October 2012

Objective

Psychological distress is common in patients with cancer. We need a rapid means of screening for and identifying depression and anxiety in patients with cancer. The present study evaluates the potential of the Eastern Cooperative Oncology Group (ECOG) performance status (PS) scoring as a brief screening tool to assess psychological distress in routine cancer care. The ECOG PS is widely used by oncologists and the WHO, as a standardised measure to assess general well-being in patients with cancer and quality of life in cancer trials. We examine the discrepancy between patient-rated and oncologist-rated PS scores on the ECOG in a comparative assessment against the Hospital Anxiety and Depression Scale (HADS).

Methods and design

This is a prospective evaluation of approximately 500 ambulatory adult cancer patients from a large academic medical centre. Participants will be asked to assess their own ECOG PS on a scale of 0–4, which will be compared to ECOG PS as rated by their oncologists. Higher ECOG PS scores indicate poorer daily functioning. Both patient-rated and oncologist-rated ECOG PS and their absolute differences will be tested for predictive and concurrent validity against the HADS. A HADS cut-off ≥15 will be used. Ethics approval for this study has been secured from the institutional ethics board. Outcomes are re-evaluated at 4-week to 6-week and 1-year follow-up.

Conclusion

This study holds practical significance for rapid screening of psychological distress in the cancer clinic with the use of the ECOG PS scoring. Given the high prevalence of anxiety and depression in patients with cancer, screening is important to increase its recognition, which will, in turn, help to direct referrals and deliver appropriate intervention. This study also generates greater insight into the association between psychosomatic complaints and psychological distress.

Trial registration number

MEC 896.52.
Managing Information to Support the Decision Making Process
Authors: Aldea Arantza , Bañares-Alcántara René , Skrzypczak Simon
Published: October 2012

Decision-making is a crucial activity during the planning, design and operation of artefacts. To make a decision several alternatives must be evaluated and compared, which are tasks that require information, knowledge and expertise. A system that organises and manages the knowledge associated with every alternative and links ideas, arguments and issues can greatly improve and facilitate the decision making process. This paper presents how an Issue Based Information System (IBIS) implemented in Compendium (http://compendium.open.ac.uk) has been extended with new functionalities such as access to a toolkit of Multi-Criteria Decision Methods (MCDM), the ability to propagate values throughout the decision records and to perform sensitivity analysis of the recommended decisions with respect to a parameter. These additional functionalities enable the applicability of the system in the support of decisions that require not only argumentation, but also numerical evaluation of the properties of the alternatives such as those proposed during the design, planning and operation of engineering artefacts.
Using Concept Maps to Assist Program Comprehension and Concept Location: An Empirical Study
Authors: Wilson Leon A. , Petrenko Maksym , Rajlich Václav
Published: October 2012

Program comprehension is an integral part of the evolution and maintenance of large software systems. As it is increasingly difficult to comprehend these systems completely, programmers have to rely on a partial and as-needed comprehension. We study partial comprehension and programmer learning with the use of concept maps as a tool for capturing programmer knowledge during concept location, which is one of the tasks of software evolution and maintenance, and it is a prerequisite of a software change. We conduct a user study to measure the performance of programmers using concept maps to assist with locating concepts. The results demonstrate that programmer learning occurs during concept location and that concept maps assisted programmers with capturing programmer learning and successful concept location.
The Effect of HRM Practices on MNC Subsidiaries' Knowledge Transfer in Thailand
Authors: Boonyarith Surapong
Published: October 2012

The study investigated how MNCs mobilise knowledge transfer fit in subsidiaries recipients. The hypotheses are developed that the knowledge transfer process via personnel aspects enhances the individual and organisational team competency to generate and transfer knowledge to fit with their recipients' needs. This empirical study is based on the data collected from two rounds of mailed questionnaire surveys of 600 MNC subsidiaries in Thailand. A total of 83 usable responses were returned, representing a response rate of 14%. The empirical results clarify some issues and propose the boundary conditions: (a) Firms should select people and orient with the kinds of knowledge to be transferred to take advantage of their effects on performance and (b) the importance of knowledge transfer through people's mobility across focal subsidiary as key drivers behind MNC's remarkable success. However, firms should not forget that in developing countries, there may be weaker informational capabilities and limited support industries.
Interactive Dynamics for Visual Analysis
Authors: Heer Jeffrey , Shneiderman Ben
Published: October 2012

The increasing scale and availability of digital data provides an extraordinary resource for informing public policy, scientific discovery, business strategy, and even our personal lives. To get the most out of such data, however, users must be able to make sense of it: to pursue questions, uncover patterns of interest, and identify (and potentially correct) errors. In concert with data-management systems and statistical algorithms, analysis requires contextualized human judgments regarding the domain-specific significance of the clusters, trends, and outliers discovered in data.
Increased TMEM16A-encoded calcium-activated chloride channel activity is associated with pulmonary hypertension
Authors: Forrest Abigail S. , Joyce Talia C. , Huebner Marissa L. , Ayon Ramon J. , Wiwchar Michael , Joyce John , Freitas Natalie , Davis Alison J. , Ye Linda , Duan Dayue D. , Singer Cherie A. , Valencik Maria L. , Greenwood Iain A. , Leblanc Normand
Published: October 2012

Pulmonary artery smooth muscle cells (PASMCs) are more depolarized and display higher Ca2+ levels in pulmonary hypertension (PH). Whether the functional properties and expression of Ca2+-activated Cl− channels (ClCa), an important excitatory mechanism in PASMCs, are altered in PH is unknown. The potential role of ClCa channels in PH was investigated using the monocrotaline (MCT)-induced PH model in the rat. Three weeks postinjection with a single dose of MCT (50 mg/kg ip), the animals developed right ventricular hypertrophy (heart weight measurements) and changes in pulmonary arterial flow (pulse-waved Doppler imaging) that were consistent with increased pulmonary arterial pressure and PH. Whole cell patch experiments revealed an increase in niflumic acid (NFA)-sensitive Ca2+-activated Cl− current [ ICl(Ca)] density in PASMCs from large conduit and small intralobar pulmonary arteries of MCT-treated rats vs. aged-matched saline-injected controls. Quantitative RT-PCR and Western blot analysis revealed that the alterations in ICl(Ca) were accompanied by parallel changes in the expression of TMEM16A, a gene recently shown to encode for ClCa channels. The contraction to serotonin of conduit and intralobar pulmonary arteries from MCT-treated rats exhibited greater sensitivity to nifedipine (1 μM), an l-type Ca2+ channel blocker, and NFA (30 or 100 μM, with or without 10 μM indomethacin to inhibit cyclooxygenases) or T16AInh-A01 (10 μM), TMEM16A/ClCa channel inhibitors, than that of control animals. In conclusion, augmented ClCa/TMEM16A channel activity is a major contributor to the changes in electromechanical coupling of PA in this model of PH. TMEM16A-encoded channels may therefore represent a novel therapeutic target in this disease.
K+-Cl− cotransporter-2 KCC2 in chicken cardiomyocytes
Authors: Antrobus Shane P. , Lytle Christian , Payne John A.
Published: October 2012

Using antibodies prepared against a unique region (exon 22–24) of rat K+-Cl− cotransporter-2 (KCC2), we confirmed that the ∼140-kDa KCC2 protein is exclusively expressed in rat brain, but in chicken, we observed strong reactivity not only with the ∼140-kDa KCC2 protein in brain but also a slightly larger ∼145-kDa protein in heart. In silico analysis showed that while exon 22 of KCC2 is unique to this isoform in therian mammals, it is retained in KCC2's closest paralog, KCC4, of lower vertebrates, including chicken. To eliminate potential cross-reactivity with chicken KCC4, the antibodies were preadsorbed with blocking peptides prepared over the only two regions showing significant sequence identity to chicken KCC4. This completely eliminated antibody recognition of exogenously expressed chicken KCC4 but not of the ∼145-kDa protein in chicken heart, indicating that chicken heart expresses KCC2. Real-time PCR confirmed robust KCC2 transcript expression in both chicken brain and heart. Chicken heart expressed predominantly the longer KCC2a splice variant consistent with the larger ∼145-kDa protein in chicken heart. Immunofluorescence microscopy revealed prominent plasma membrane KCC2 labeling in chicken ventricular cardiomyocytes. We hypothesize that KCC2 is an important Cl− extrusion pathway in avian cardiomyocytes that counters channel-mediated Cl− loading during high heart rates with β-adrenergic stimulation. While KCC2 is absent from mammalian cardiomyocytes, understanding the role that the other KCC isoforms play in Cl− homeostasis of these cells represents a nascent area of research.
High-performance execution of psychophysical tasks with complex visual stimuli in MATLAB
Authors: Asaad Wael F. , Santhanam Navaneethan , McClellan Steven , Freedman David J.
Published: October 2012

Behavioral, psychological, and physiological experiments often require the ability to present sensory stimuli, monitor and record subjects' responses, interface with a wide range of devices, and precisely control the timing of events within a behavioral task. Here, we describe our recent progress developing an accessible and full-featured software system for controlling such studies using the MATLAB environment. Compared with earlier reports on this software, key new features have been implemented to allow the presentation of more complex visual stimuli, increase temporal precision, and enhance user interaction. These features greatly improve the performance of the system and broaden its applicability to a wider range of possible experiments. This report describes these new features and improvements, current limitations, and quantifies the performance of the system in a real-world experimental setting.
Neural Crest Stem Cells from Dental Tissues: A New Hope for Dental and Neural Regeneration
Authors: Ibarretxe Gaskon , Crende Olatz , Aurrekoetxea Maitane , García-Murga Victoria , Etxaniz Javier , Unda Fernando
Published: October 2012

Several stem cell sources persist in the adult human body, which opens the doors to both allogeneic and autologous cell therapies. Tooth tissues have proven to be a surprisingly rich and accessible source of neural crest-derived ectomesenchymal stem cells (EMSCs), which may be employed to repair disease-affected oral tissues in advanced regenerative dentistry. Additionally, one area of medicine that demands intensive research on new sources of stem cells is nervous system regeneration, since this constitutes a therapeutic hope for patients affected by highly invalidating conditions such as spinal cord injury, stroke, or neurodegenerative diseases. However, endogenous adult sources of neural stem cells present major drawbacks, such as their scarcity and complicated obtention. In this context, EMSCs from dental tissues emerge as good alternative candidates, since they are preserved in adult human individuals, and retain both high proliferation ability and a neural-like phenotypein vitro. In this paper, we discuss some important aspects of tissue regeneration by cell therapy and point out some advantages that EMSCs provide for dental and neural regeneration. We will finally review some of the latest research featuring experimental approaches and benefits of dental stem cell therapy.
On the Computation of the Efficient Frontier of the Portfolio Selection Problem
Authors: Calvo Clara , Ivorra Carlos , Liern Vicente
Published: October 2012

An easy‐to‐use procedure is presented for improving the ε‐constraint method for computing the efficient frontier of the portfolio selection problem endowed with additional cardinality and semicontinuous variable constraints. The proposed method provides not only a numerical plotting of the frontier but also an analytical description of it, including the explicit equations of the arcs of parabola it comprises and the change points between them. This information is useful for performing a sensitivity analysis as well as for providing additional criteria to the investor in order to select an efficient portfolio. Computational results are provided to test the efficiency of the algorithm and to illustrate its applications. The procedure has been implemented in Mathematica.
Association of Perceived Stress with Stressful Life Events, Lifestyle and Sociodemographic Factors: A Large-Scale Community-Based Study Using Logistic Quantile Regression
Authors: Feizi Awat , Aliyari Roqayeh , Roohafza Hamidreza
Published: October 2012

Objective. The present paper aimed at investigating the association between perceived stress and major life events stressors in Iranian general population.Methods. In a cross-sectional large-scale community-based study, 4583 people aged 19 and older, living in Isfahan, Iran, were investigated. Logistic quantile regression was used for modeling perceived stress, measured by GHQ questionnaire, as the bounded outcome (dependent), variable, and as a function of most important stressful life events, as the predictor variables, controlling for major lifestyle and sociodemographic factors. This model provides empirical evidence of the predictors’ effects heterogeneity depending on individual location on the distribution of perceived stress.Results. The results showed that among four stressful life events, family conflicts and social problems were more correlated with level of perceived stress. Higher levels of education were negatively associated with perceived stress and its coefficients monotonically decrease beyond the 30th percentile. Also, higher levels of physical activity were associated with perception of low levels of stress. The pattern of gender’s coefficient over the majority of quantiles implied that females are more affected by stressors. Also high perceived stress was associated with low or middle levels of income.Conclusions. The results of current research suggested that in a developing society with high prevalence of stress, interventions targeted toward promoting financial and social equalities, social skills training, and healthy lifestyle may have the potential benefits for large parts of the population, most notably female and lower educated people.
Effects of Annealing Environments on the Solution‐Grown, Aligned Aluminium‐Doped Zinc Oxide Nanorod‐Array‐Based Ultraviolet Photoconductive Sensor
Authors: Mamat Mohamad Hafiz , Che Khalin Mohd Izzudin , Nik Mohammad Nik Noor Hafizah , Khusaimi Zuraida , Md Sin Nor Diyana , Shariffudin Shafinaz Sobihana , Mohamed Zahidi Musa , Mahmood Mohamad Rusop
Published: October 2012

We have fabricated metal‐semiconductor‐metal‐ (MSM‐) type ultraviolet (UV) photoconductive sensors using aluminium‐ (Al‐) doped zinc oxide (ZnO) nanorod arrays that were annealed in different environments: air, oxygen, or a vacuum. The Al‐doped ZnO nanorods had an average diameter of 60 nm with a thickness of approximately 600 nm that included the seed layer (with thickness ~200 nm). Our results show that the vacuum‐annealed nanorod‐array‐based UV photoconductive sensor has the highest photocurrent value of   2.43   ×   10−4 A. The high photocurrent is due to the high concentration of zinc (Zn) interstitials in the vacuum‐annealed nanorod arrays. In contrast, the oxygen‐annealing process applied to the Al‐doped ZnO nanorod arrays produced highly sensitive UV photoconductive sensors, in which the sensitivity reached 55.6, due to the surface properties of the oxygen‐annealed nanorods, which have a higher affinity for oxygen adsorption than the other samples and were thereby capable of reducing the sensor’s dark current. In addition, the sensor fabricated using the oxygen‐annealed nanorod arrays had the lowest rise and decay time constants. Our result shows that the annealing environment greatly affects the surface condition and properties of the Al‐doped ZnO nanorod arrays, which influences the performance of the UV photoconductive sensors.