bluuebunny/crossref_metadata_2025 huggingface dataset:
EDUCATIONAL TESTING AND TEST‐FORM FACTORS
Authors: Vernon Philip E.
Published: August 2014

Evidence is here brought together suggesting that educational and other psychological tests are appreciably dependent not only on the abilities that they are supposed to measure, but on the form and material of the tests and their items, sets and attitudes in the testees, and various conditions of testing. The factors that emerge when tests are inter‐correlated represent to some extent these formal characteristics rather than desired intellectual functions. In particular this applies to current educational tests which, for sound educational reasons, avoid simpler, more factual, items and prefer complex comprehension‐type or problem items.

Part II shows that, while tests of the same objectives employing different forms tend to give discrepant results (e.g., essay and new‐type), tests in the same form which are aimed at different school subjects or different intellectual functions inter‐correlate very highly. This detracts from their validity, especially in counseling or differentiating abilities along different lines. For many purposes the simpler tests show superior validity, and it is doubtful how far the more complex ones do bring in the ‘higher’ intellectual functions at which they are aimed.

Part III argues that, in like manner, most of the cognitive factors established by psychologists show little relevance to educational or other external criteria, possibly because they represent factors within paper‐and‐pencil tests rather than genuine factors of intellect.

Part IV. A first essential is to map out more precisely the extent and nature of form influences, so that, in so far as they prove to be important, account can be taken of them in test construction. A number of types of predictive measures are discussed which might add more to the validity of educational selection, particularly at college level, than do complex forms of reading tests. These include: better use of essay examinations and school grades, listening comprehension tests, speed and error scores, indices of study habits, tests based on learning situations, and tests of rational thinking, flexibility and creativity. When tests are used primarily for evaluation rather than prediction, investigations should be guided by the conception of intrinsic or construct validity, which – unlike logical or face validity – involves the collection of empirical evidence. Some of the more promising approaches to such problems are through factorial studies of educational tests along with tests of psychological factors and ‘real‐life’ criteria, and experimental studies of group differences and of the gains brought about by different types of teaching.
NOTE ON “TESTS OF THE SAME LENGTH DO HAVE THE SAME STANDARD ERROR OF MEASUREMENT”1
Authors: Swineford Frances
Published: August 2014

Lord has reported a high relation between the K‐R (20) standard error of measurement and test length. The present inquiry leads to an expression of this relation in terms of item variances and covariances and indicates the ranges of these values normally found for ETS tests.
AN INDEX OF THE DISCRIMINATING POWER OF A TEST AT DIFFERENT PARTS OF THE SCORE RANGE
Authors: Levine Richard , Lord Frederic M.
Published: August 2014

An important characteristic of any test is its ability to discriminate among examinees who differ in ability. The conventional reliability and validity coefficients are indices of discrimination for the test as a whole; however, except under certain limited conditions, these over‐all indices do not apply at all points along the score scale. The purpose of the present paper is to provide such an index and illustrate its use.
FURTHER IMPLICATIONS OF MUNDY‐CASTLE'S CORRELATIONS BETWEEN EEG AND WECHSLER‐BELLEVUE VARIABLES1
Authors: Saunders D. R.
Published: August 2014

Factor analysis is re‐applied, using relatively more rigorous methods, to a 15 × 15 correlation matrix reported by Mundy‐Castle and containing 11 Wechsler‐Bellevue subtest variables, 2 EEG variables, age and occupational level, for a sample of 34 employees of the South African National Institute for Personnel Research. Six common factors were extracted and subjected to orthogonal rotation in search of meaningful simple structure.

Two age‐related factors were found and respectively identified as “Experience” and “Deterioration.” (Factors I and II.)

Within the residual four‐space, the vectors for alpha Frequency in the EEG and Digit Span performance in the W‐B were found to be comparable. (Factor III.) This result is discussed in relation to the excitability cycle hypothesis, primary vs. secondary function, and externalization vs. internalization.

The vector for alpha Index was found to have a near perfect communality in the residual three‐space, and is interpreted as measuring (inversely) strength of “Conditioned Attentiveness.” (Factor IV.) Picture Completion in the W‐B is judged to depend partially on this factor.

The remaining two factors are of minor interest since they are probably mixtures of things that could not be distinguished in this study using only 15 variables and 34 cases.

It is suggested that a proper interpretation for common factors, when there have not been enough variables to preclude the existence of specific factors, is in terms of dynamic mechanisms presumptive of a cause‐effect relationship between loaded variables, rather than in terms of hypothetical underlying variables. Factors I, IV, and V can be used to illustrate this principle.
Mechanical characterization of a bifunctional Tetronic hydrogel adhesive for soft tissues
Authors: Sanders Lindsey , Stone Roland , Webb Kenneth , Mefford Thompson , Nagatomi Jiro
Published: August 2014

Although a number of tissue adhesives and sealants for surgical use are currently available, attaining a useful balance in high strength, high compliance, and low swelling has proven difficult. Recent studies have demonstrated that a four‐arm poly(propylene oxide)‐poly(ethylene oxide) block copolymer, Tetronic, can be chemically modified to form a hydrogel tissue adhesive (Cho et al., Acta Biomater 2012;8:2223–2232; Barrett et al., Adv Health Mater 2012;1–11; Balakrishnan, Evaluating mechanical performance of hydrogel‐based adhesives for soft tissue applications. Clemson University, All Theses, Paper 1574: Tiger Prints; 2013). Building on the success of these studies, this study explored bifunctionalization of Tetronic with acrylates for chemical crosslinking of the hydrogel and N‐hydroxysuccinimide (NHS) for reaction with tissue amines. The adhesive bond strengths of various uni and bifunctional Tetronic blends (T1107 ACR: T1107 ACR/NHS) determined by lap shear testing ranged between 8 and 74 kPa, with the 75:25 (T1107 ACR: T1107 ACR/NHS) blend displaying the highest value. These results indicated that addition of NHS led to improvement of tissue bond strength over acrylation alone. Furthermore, ex vivo pressure tests using the rat bladder demonstrated that the bifunctional Tetronic adhesive exhibited high compliance and maintained pressures under hundreds of filling and emptying cycles. Together, the results of this study provided evidence that the bifunctional Tetronic adhesive with a proper blend ratio may be used to achieve an accurate balance in bulk and tissue bond strengths, as well as the compliance and durability for soft tissue such as the bladder. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 861–868, 2015.
Extracellular matrix components of adipose derived stromal cells promote alignment, organization, and maturation of cardiomyocytes in vitro
Authors: Przybyt Ewa , van Luyn Marja J. A. , Harmsen Martin C.
Published: August 2014

Adipose derived stromal cells (ADSC) are relevant therapeutic agents to treat myocardial infarction (MI) in clinical trials. Soluble factors secreted by ADSC, such as growth factors and cytokines, suppress inflammation and apoptosis while promoting angiogenesis and the proliferation of cardiomyocytes (CM). Moreover, ADSC synthesize extracellular matrix (ECM) components into the intercellular space which might contribute to their therapeutic capacity. Thus, ADSC might directly modulate the post‐MI microenvironment through a combination of paracrine and juxtacrine signaling. In this study, the juxtacrine role of ADSC and ADSC‐derived ECM on the organization and maturation of CM was investiagated. Human ADSC synthesized and deposited a heterogenous and complex mixture of ECM components such as collagen I, III, IV, fibronectin, elastin as well as the matricellular protein periostin. Cocultures of rodent CM with human ADSC or with human ADSC‐derived ECM components enhanced the cardiomyocyte alignment, their intercellular connections and the maturation of their sarcomeres, while the proliferation rate of the CM was increased and their level of hypertrophy reduced. The use of human ADSC‐derived ECM could serve both to augment in vitro tissue‐engineered myocardial constructs and to improve myocardial remodeling after infarction. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1840–1848, 2015.
HEAD START ENROLLMENT AND CHILDREN'S MENTAL HEALTH TREATMENT
Authors: Lee Kyunghee
Published: August 2014

This secondary data analysis from a Head Start program examines the association between children's entry age and enrollment duration and the likelihood of mental health treatment. Study questions are as follows: (a) Do baseline characteristics differ among three groups of Head Start children? (children who enrolled at 3 years of age and stayed for 1 year [group 1], enrolled at 4 years of age and stayed for 1 year [group 2], and enrolled at 3 years of age and stayed for 2 years [group 3]); (b) Does the likelihood of children's mental health treatment differ among the groups?; and (c) Are baseline characteristics associated with the likelihood of mental health treatment? Except ethnicity and family size, other baseline characteristics did not differ across the three groups. Groups 1 and 3 received more mental health treatment than group 2. Different percentages of mental health treatment were found, depending on children's gender, ethnicity, family income, special needs, and bilingual status.
HOW THEATER WITHIN A TRANSFORMATIVE ORGANIZING FRAMEWORK CULTIVATES INDIVIDUAL AND COLLECTIVE EMPOWERMENT AMONG LGBTQQ YOUTH
Authors: Wernick Laura J. , Kulick Alex , Woodford Michael R.
Published: August 2014

Lesbian, gay, bisexual, transgender, queer, and questioning (LGBTQQ) youth experience oppression in their schools and communities, which creates barriers to their healthy development. Emerging research documents strategies to support LGBTQQ youth, but little is known about developing LGBTQQ youth empowerment. This study extracts qualitative data (key informant interviews, n = 8, and a focus group, n = 8) from a larger case study of an LGBTQQ youth organization that uses theater within a transformative organizing model to make their schools safer and more inclusive. Findings suggest that theater–both theater games used within the group and scripted performances for adult stakeholders–uniquely contributed to developing individual and collective empowerment through an iterative process of building community, cultivating critical consciousness, and providing opportunities to effect change. Encouraging creative expression alongside developing LGBTQQ youth's capacity to create change can contribute to the positive development of LGBTQQ youth.
A new model army: Emerging fish models to study the genomics of vertebrate Evo‐Devo
Authors: Braasch Ingo , Peterson Samuel M. , Desvignes Thomas , McCluskey Braedan M. , Batzel Peter , Postlethwait John H.
Published: August 2014

Many fields of biology—including vertebrate Evo‐Devo research—are facing an explosion of genomic and transcriptomic sequence information and a multitude of fish species are now swimming in this “genomic tsunami.” Here, we first give an overview of recent developments in sequencing fish genomes and transcriptomes that identify properties of fish genomes requiring particular attention and propose strategies to overcome common challenges in fish genomics. We suggest that the generation of chromosome‐level genome assemblies—for which we introduce the term “chromonome”—should be a key component of genomic investigations in fish because they enable large‐scale conserved synteny analyses that inform orthology detection, a process critical for connectivity of genomes. Orthology calls in vertebrates, especially in teleost fish, are complicated by divergent evolution of gene repertoires and functions following two rounds of genome duplication in the ancestor of vertebrates and a third round at the base of teleost fish. Second, using examples of spotted gar, basal teleosts, zebrafish‐related cyprinids, cavefish, livebearers, icefish, and lobefin fish, we illustrate how next generation sequencing technologies liberate emerging fish systems from genomic ignorance and transform them into a new model army to answer longstanding questions on the genomic and developmental basis of their biodiversity. Finally, we discuss recent progress in the genetic toolbox for the major fish models for functional analysis, zebrafish, and medaka, that can be transferred to many other fish species to study in vivo the functional effect of evolutionary genomic change as Evo‐Devo research enters the postgenomic era. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 316–341, 2015. © 2014 Wiley Periodicals, Inc.
Characterization of the 1970s climate shift in South America
Authors: Jacques‐Coper Martín , Garreaud René D.
Published: August 2014

The 1976–1977 cold‐to‐warm sea surface temperature (SST) shift in the tropical Pacific Ocean, which has been associated with a phase change of the Pacific Decadal Oscillation (PDO) index, separated a ‘La Niña‐like’ decadal regime from an ‘El Niño‐like’ one. In this article, we analyse the differences of mean of annual and austral‐summer (DJF) temperature, precipitation, and sea‐level pressure (SLP) over South America (SA) between 1961–1973 and 1978–1990, and explore the occurrence of significant shifts in their time series. Our sources are instrumental records, gridded interpolated data, and reanalyses. Although major regional differences in the intensity of the signal are detected, the climate shift is identified in all variables. In the mid‐1970s at annual level, reanalysis SLP data reveal the onset of a step‐like anticyclonic circulation anomaly in the southern tip of SA and an abrupt weakening of the Southeast Pacific Subtropical Anticyclone (SEPA). This latter feature may have partly induced the rapid warming observed along the tropical–extratropical west coast of the continent through the weakening of the cold Humboldt current system. An abrupt warming was also detected in surface air temperature (SAT) composites located along the coast of the northern part of SA and in Southeastern SA (SESA). During summer, we found a particularly conspicuous shift‐like warming over Southern South America (SSA, comprising Patagonia). Besides, a shift‐like increase (decrease) in annual mean precipitation is observed over Central Argentina and in the tropics, to the south (north) of 10°S. In line with previous studies, we conclude that both the interannual (El Niño‐Southern Oscillation, ENSO) and the interdecadal (PDO) variability modes seem to have had an incidence in the manifestation of the 1970s climate shift, and that its magnitude appears to be unprecedented during the 20th century, as shown in particular by century‐long SAT composites from northern Chile and SSA.
Outcomes in operative management of pancreatic cancer
Authors: Bliss Lindsay A. , Witkowski Elan R. , Yang Catherine J. , Tseng Jennifer F.
Published: August 2014

Pancreatic cancer is a highly lethal malignancy that often presents at an advanced stage. Surgical resection can prolong survival and offers the only potential for cure. However, pancreatectomy is associated with significant morbidity and mortality. This article reviews perioperative outcomes, post‐resection long‐term survival, and innovations in the surgical management of pancreatic cancer. J. Surg. Oncol. 2014 110:592–598. © 2014 Wiley Periodicals, Inc.
Ultrasensitive terahertz/infrared waveguide modulators based on multilayer graphene metamaterials
Authors: Khromova Irina , Andryieuski Andrei , Lavrinenko Andrei
Published: August 2014

This paper studies and classifies the electromagnetic regimes of multilayer graphene‐dielectric artificial metamaterials in the terahertz/infrared range. The employment of such composites for waveguide‐integrated modulators is analysed and three examples of novel tunable devices are presented. The first one is a modulator with excellent ON‐state transmission and very high modulation depth: >38 dB at 70 meV graphene's electrochemical potential (Fermi energy) change. The second one is a modulator with extreme sensitivity towards graphene's Fermi energy ‐ a minute 1 meV variation of the latter leads to >13.2 dB modulation depth. The third one is a tunable waveguide‐based passband filter. The narrow‐band cut‐off conditions around the ON‐state allow the latter to shift its central frequency by 1.25% per every meV graphene's Fermi energy change.
Kinetic Analysis of Mechanochemical Chain Scission of Linear Poly(phthalaldehyde)
Authors: Peterson Gregory I. , Boydston Andrew J.
Published: August 2014

The kinetics of mechanochemical chain scission of poly(phthalaldehyde) (PPA) are investigated. Ultrasound‐induced cavitation is capable of causing chain scission in the PPA backbone that ultimately leads to rapid depolymerization of each resulting polymer fragment when above the polymer's ceiling temperature (Tc). An interesting feature of the mechanochemical breakdown of PPA is that “half‐chain” daughter fragments are not observed, since the depolymerization is rapid following chain scission. These features facilitate the determination of rate constants of activation for multiple molecular weights from a single sonication experiment. Additionally, the degradation kinetics are modified with chain‐end trapping agents through variation of the nature and amount of small molecule nucleophile or electrophile.

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In vivo gastric detection of α‐synuclein inclusions in Parkinson's disease
Authors: Sánchez‐Ferro Álvaro , Rábano Alberto , Catalán María José , Rodríguez‐Valcárcel Fernando Canga , Díez Servando Fernández , Herreros‐Rodríguez Jaime , García‐Cobos Elvira , Álvarez‐Santullano Marina Mata , López‐Manzanares Lydia , Mosqueira Antonio J. , Desojo Lydia Vela , López‐Lozano Juan José , López‐Valdés Eva , Sánchez‐Sánchez Rafael , Molina‐Arjona José Antonio
Published: August 2014

α‐Synuclein inclusions have been identified in the brain and some parts of the enteric nervous system in Parkinson's disease cases. We aimed to assess these inclusions in gastric mucosa samples from patients with symptomatic Parkinson's disease. Random biopsies were performed by gastroscopy in 28 patients with Parkinson's disease and in 29 age‐ and sex‐matched controls. Gastroscopy was performed to start enteral levodopa (l‐dopa) therapy in cases and for diagnostic purposes in controls (gastroesophageal reflux, anemia, and abdominal pain were the main indications). The clinical definition of cases and controls was made a priori. Six controls had data suggestive of “mild presymptomatic parkinsonism”. Biopsy specimens were immunostained for α‐synuclein. The neuropathological diagnosis was established post hoc. No differences were found in the baseline characteristics of the groups. Positive fibers for the α‐synuclein protein were observed in 17 of 28 (60.7%) Parkinson's disease patients, 1 of 23 controls (4.3%), and 1 of 6 (16.7%) cases of incident “mild presymptomatic parkinsonism.” Neuropathological diagnosis based on α‐synuclein immunostaining showed a sensitivity of 85% (95% confidence interval [CI] 62.1‐96.8), specificity of 95% (95% CI 76.2‐99.9) and area under the receiver operating characteristics curve (AUC) of 0.90 (95% CI 0.80‐1.00). No adverse events occurred. Detection of α‐synuclein inclusions in the gastric mucosa is a useful and safe tool providing in vivo evidence of the underlying neurodegenerative peripheral involvement linked to Parkinson's disease. Further studies are warranted to determine its pathophysiological implications. © 2014 International Parkinson and Movement Disorder Society
Simultaneous T1 and T2 quantification of the myocardium using cardiac balanced‐SSFP inversion recovery with interleaved sampling acquisition (CABIRIA)
Authors: Santini Francesco , Kawel‐Boehm N. , Greiser A. , Bremerich J. , Bieri O.
Published: August 2014

Purpose

To develop a novel sequence for simultaneous quantification of T1 and T2 relaxation times in the myocardium based on the transient phase of the balanced steady‐state free precession.

Methods

A new prototype sequence, named “cardiac balanced‐SSFP inversion recovery with interleaved sampling acquisition” (CABIRIA) was developed based on a single‐shot bSSFP readout following an inversion pulse. With this method, T1 and T2 values can be calculated from the analysis of signal evolution. The scan duration for a single slice in vivo was 8 heartbeats, thus feasible in a breath‐hold. The sequence was validated both in vitro by comparing it to conventional inversion recovery and multi‐echo spin‐echo methods and in 5 healthy volunteers by comparing it to the Modified Look‐Locker Inversion Recovery (MOLLI) sequence and to a T2 quantification sequence based on multi‐T2‐prepared bSSFP.

Results

The method showed good agreement with conventional methods for both T1 and T2 measurements (concordance correlation coefficient ≥ 0.99) in vitro. In healthy volunteers the measured T1 values were 1227 ± 68 ms and T2 values 37.9 ± 2.4 ms, with similar inter‐ and intrasubject variability with respect to existing methods.

Conclusion

The proposed CABIRIA method enables simultaneous quantification of myocardial T1 and T2 values with good accuracy and precision. Magn Reson Med 74:365–371, 2015. © 2014 Wiley Periodicals, Inc.
Power spectral changes of the superimposed M wave during isometric voluntary contractions of increasing strength
Authors: Rodriguez‐Falces Javier , Place Nicolas
Published: August 2014

Introduction: We examined the power spectral changes of the compound muscle action potential (M wave) evoked during isometric contractions of increasing strength. Methods: Surface electromyography (sEMG) of the vastus lateralis and medialis was recorded from 20 volunteers who performed 4‐s step‐wise isometric contractions of different intensities. A maximal M wave was elicited by a single stimulus to the femoral nerve and superimposed on the voluntary contractions. The spectral characteristics (Fmean and Fmedian) of sEMG and M‐wave signals were calculated. Results: M‐wave spectral indicators increased systematically with contraction intensity up to 60% MVC and then leveled off at higher forces. Over the 10–60% MVC range, the increase in spectral indicators was 3 times higher for M waves (36%) than for sEMG (12%). Conclusions: The consistent increase in M‐wave spectral characteristics with force is due to the fact that the number of motor units recruited by the superimposed supramaximal stimulus is approximately stable. Muscle Nerve 51: 580–591, 2015
The National ALS Registry: A recruitment tool for research
Authors: Malek Angela M. , Stickler David E. , Antao Vinicius C. , Horton D. Kevin
Published: August 2014

Introduction: Subject recruitment is critical for understanding fatal diseases like ALS, however linking patients with researchers can be challenging. The U.S. population‐based National ALS Registry allows recruitment of persons with ALS (PALS) for research opportunities. Methods: The Registry's Research Notification Mechanism was used to recruit PALS aged ≥21 years; participants completed a Web‐based epidemiologic survey. PALS (n = 2,232) were sent an email describing the study, and 268 surveys were completed. Results: The mean age (± SD) of eligible participants was 57.7 ± 9.3 years for men and 61.5 ± 8.9 for women. Most were men (63%) and Caucasian (92%). Of 256 potentially eligible participants, 37.5% (n = 96) returned an authorization to disclose protected health information. ALS was confirmed for 94% (83/88) from physician responses. Conclusions: This analysis demonstrates the National ALS Registry's usefulness in recruiting PALS for research. This recruitment source can potentially foster the discovery of better treatment options and therapies, and of prevention strategies. Muscle Nerve 50: 830–834, 2014
Structural and mutational studies on an aldo‐keto reductase AKR5C3 from Gluconobacter oxydans
Authors: Liu Xu , Wang Chao , Zhang Lujia , Yao Zhiqiang , Cui Dongbing , Wu Liang , Lin Jinping , Yuan Yu‐Ren Adam , Wei Dongzhi
Published: August 2014

An aldo‐keto reductase AKR5C3 from Gluconobacter oxydans (designated as Gox0644) is a useful enzyme with various substrates, including aldehydes, diacetyl, keto esters, and α‐ketocarbonyl compounds. The crystal structures of AKR5C3 in apoform in complex with NADPH and the D53A mutant (AKR5C3‐D53A) in complex with NADPH are presented herein. Structure comparison and site‐directed mutagenesis combined with biochemical kinetics analysis reveal that the conserved Asp53 in the AKR5C3 catalytic tetrad has a crucial role in securing active pocket conformation. The gain‐of‐function Asp53 to Ala mutation triggers conformational changes on the Trp30 and Trp191 side chains, improving NADPH affinity to AKR5C3, which helps increase catalytic efficiency. The highly conserved Trp30 and Trp191 residues interact with the nicotinamide moiety of NADPH and help form the NADPH‐binding pocket. The AKR5C3‐W30A and AKR5C3‐W191Y mutants show decreased activities, confirming that both residues facilitate catalysis. Residue Trp191 is in the loop structure, and the AKR5C3‐W191Y mutant does not react with benzaldehyde, which might also determine substrate recognition. Arg192, which is involved in the substrate binding, is another important residue. The introduction of R192G increases substrate‐binding affinity by improving hydrophobicity in the substrate‐binding pocket. These results not only supplement the AKRs superfamily with crystal structures but also provide useful information for understanding the catalytic properties of AKR5C3 and guiding further engineering of this enzyme.
Grip it and rip it: Structural mechanisms of DNA helicase substrate binding and unwinding
Authors: Bhattacharyya Basudeb , Keck James L.
Published: August 2014

Maintenance and faithful transmission of genomic information depends on the efficient execution of numerous DNA replication, recombination, and repair pathways. Many of the enzymes that catalyze steps within these pathways require access to sequence information that is buried in the interior of the DNA double helix, which makes DNA unwinding an essential cellular reaction. The unwinding process is mediated by specialized molecular motors called DNA helicases that couple the chemical energy derived from nucleoside triphosphate hydrolysis to the otherwise non‐spontaneous unwinding reaction. An impressive number of high‐resolution helicase structures are now available that, together with equally important mechanistic studies, have begun to define the features that allow this class of enzymes to function as molecular motors. In this review, we explore the structural features within DNA helicases that are used to bind and unwind DNA. We focus in particular on “aromatic‐rich loops” that allow some helicases to couple single‐stranded DNA binding to ATP hydrolysis and “wedge/pin” elements that provide mechanical tools for DNA strand separation when connected to translocating motor domains.
Conformational and aggregation properties of the 1–93 fragment of apolipoprotein A‐I
Authors: Petrlova Jitka , Bhattacherjee Arnab , Boomsma Wouter , Wallin Stefan , Lagerstedt Jens O. , Irbäck Anders
Published: August 2014

Several disease‐linked mutations of apolipoprotein A‐I, the major protein in high‐density lipoprotein (HDL), are known to be amyloidogenic, and the fibrils often contain N‐terminal fragments of the protein. Here, we present a combined computational and experimental study of the fibril‐associated disordered 1–93 fragment of this protein, in wild‐type and mutated (G26R, S36A, K40L, W50R) forms. In atomic‐level Monte Carlo simulations of the free monomer, validated by circular dichroism spectroscopy, we observe changes in the position‐dependent β‐strand probability induced by mutations. We find that these conformational shifts match well with the effects of these mutations in thioflavin T fluorescence and transmission electron microscopy experiments. Together, our results point to molecular mechanisms that may have a key role in disease‐linked aggregation of apolipoprotein A‐I.
A novel comprehensive steganalysis of transmission control protocol/Internet protocol covert channels based on protocol behaviors and support vector machine
Authors: Shen Yao , Huang Liusheng , Lu Xiaorong , Yang Wei
Published: August 2014

Covert channels are malicious conversations disguised in legitimate network communications, allowing information leak to the unauthorized or unknown receiver. Various network steganographic schemes that modify the header fields of transmission control protocol/Internet protocol (TCP/IP) have been proposed in recent years. People before conducted detection research based on the surface content of the header field and did not take into account the differences between the behavior characters of covert channels and the inherent behavior regularities of the header fields. Up to date, there is little comprehensive research on the steganalysis against the storage covert channels. In this paper, we focus on the detection of storage covert channels and introduce a novel comprehensive detection method based on the protocol behaviors. The protocol behavior characters are utilized to evaluate the regularities or correlations of header fields between adjacent packets according to the conventional use. First, the behavior features of the header fields in TCP/IP are extracted; a support vector machine is then applied to the behavior feature sets for discovering the existence of covert channels. Some recognized covert channel tools are detected in our detection experiment. Experimental results and discussion show that our detection method is of effectiveness. Copyright © 2014 John Wiley & Sons, Ltd.
Enhanced Fluorescence of Gold Nanoclusters Composed of HAuCl4 and Histidine by Glutathione: Glutathione Detection and Selective Cancer Cell Imaging
Authors: Zhang Xiaodong , Wu Fu‐Gen , Liu Peidang , Gu Ning , Chen Zhan
Published: August 2014

Glutathione (GSH) can significantly and selectively enhance the fluorescence intensity of Au nanoclusters (NCs) prepared by blending HAuCl4 and histidine in solution. The quantum yield of the Au NCs after adding GSH can reach above 10%. Besides, GSH capping shifts the excitation peak of Au NCs from ultraviolet (386 nm) to visible light (414 nm) and improves the stability of the Au NCs. The cytotoxicities of the Au NCs with and without GSH for normal lung cells (ATII) and cancerous lung cells (A549) are evaluated. The GSH‐capped Au NCs have much less cytotoxicity to both normal and cancer cells, as compared to those without GSH. For Au NCs without GSH, less cytotoxicity is observed in cancer cells than in normal cells. In addtion, the Au NCs can selectively detect GSH over cysteine and homocysteine, the two biothiols which commonly exist in cells that can seriously affect GSH detection. Most importantly, Au NCs without GSH can selectively image the cancer cells, especially for the liver cancer cells whose GSH content is much higher than other cell types. This property makes the Au NCs a powerful probe to distinguish cancer cells from normal cells.
Concise Review: Understanding Clonal Dynamics in Homeostasis and Injury Through Multicolor Lineage Tracing
Authors: Roy Edwige , Neufeld Zoltan , Livet Jean , Khosrotehrani Kiarash
Published: August 2014

Lineage tracing is an essential tool to study stem cell fate. Although traditional lineage tracing techniques have considerably advanced our understanding of stem cell behavior, they pose significant limitations for identification and longitudinal tracking of the progeny of individual stem cells, to compare their behaviors. This is of importance given the well-established heterogeneity among stem cells both in terms of potentialities and proliferative capacities. The recent development of multicolor genetic reporters addressable to specific cell populations largely overcomes these issues. These new “rainbow” technologies provide increased resolution in clonal identification and offer the possibility to study the relative distribution, contacts, tiled arrangement, and competitive interactions among cells or groups of cells of the same type. Stem Cells  2014;32:3046–3054
The effect of online collaboration on middle school student science misconceptions as an aspect of science literacy
Authors: Wendt Jillian L. , Rockinson‐Szapkiw Amanda
Published: August 2014

This quantitative, quasi‐experimental pretest/posttest control group design examined the effects of online collaborative learning on middle school students' science literacy. For a 9‐week period, students in the control group participated in collaborative face‐to‐face activities whereas students in the experimental group participated in online collaborative activities using the Edmodo educational platform. Students at a public middle school in central Virginia completed both a pretest and a posttest consisting of the Misconceptions‐Oriented Standards‐Based Assessment Resources for Teachers (MOSART) assessment to measure science misconceptions as an aspect of science literacy. Results indicated that the students who participated in collaborative activities in the traditional classroom had fewer science misconceptions than students who participated in collaborative activities in the online environment. Moreover, from pretest to posttest, the students in the experimental group increased in their science misconceptions. Suggestions for practice and future research are discussed in light of these results. © 2014 Wiley Periodicals, Inc. J Res Sci Teach 51: 1103–1118, 2014
Wake modelling of a VAWT in dynamic stall: impact on the prediction of flow and induction fields
Authors: Zanon Alessandro , Giannattasio Pietro , Simão Ferreira Carlos J.
Published: August 2014

Dynamic stall is a relevant phenomenon in the design and operation of a vertical axis wind turbine (VAWT) as it impacts loading, control and wake dynamics. Although streamtube models and single‐wake vortex models are commonly used for VAWT simulation, they either do not explicitly simulate the distribution of vorticity in the wake (streamtube models) or simplify it into a single‐wake release point (single‐wake vortex models). This can lead to inaccurate predictions of the vorticity distribution and wake dynamics, and therefore of the induction field, rotor loading and wake development, including wake mixing and re‐energizing. In this work, we use a double‐wake panel model developed for the simulation of dynamic stall in a VAWT to analyse (i) what is the flow field in dynamic stall, including the induction field, (ii) what is the error due to assuming a simplified wake, in both vorticity distribution and induction and (iii) how an incorrect simulation of the vorticity distribution can affect the prediction of the dynamics of the near and far wake. The results demonstrate that for mild separation (tip speed ratio λ≥3), single‐wake models can produce acceptable results. However, for lower tip speed ratios (λ < 3), the inaccuracy in the prediction of loads, induction field and vorticity distribution becomes significant because of an inadequate representation of the wake dynamics. These results imply that using lower order models can lead to inaccurate estimations of loads, performance and power control requirements at low tip speed ratios. Copyright © 2014 John Wiley & Sons, Ltd.
Diurnal space use and seasonal movement patterns of greater sage‐grouse in Northeastern California
Authors: Davis Dawn M. , Reese Kerry P. , Gardner Scott C.
Published: August 2014

Greater sage‐grouse (Centrocercus urophasianus) populations have declined throughout their geographic range, are considered a candidate species under the U.S. Endangered Species Act, and are regarded as a species of special concern in California, USA. Demographic parameters have been well‐documented for this species, but populations occupying the western periphery of their range have largely remained unstudied. We examined diurnal space use and seasonal movement patterns of greater sage‐grouse in northeastern California. We collected 3,072 diurnal locations from 132 greater sage‐grouse radiomarked between 2007 and 2009. Greater sage‐grouse in our study used large areas and exhibited wide‐ranging seasonal movements. Female greater sage‐grouse sought suitable nesting habitat within 5 km of a lek; however, of the 27% (n = 20/74) of females nesting >5 km from an occupied lek site, 53% (n = 10/19) nested successfully. This suggests the proportion of nesting females located >5 km from an active lek is important for population viability in northeastern California. Moreover, the annual range of movements indicates that conserving greater sage‐grouse habitat within 5 km of active lek sites is insufficient to maintain long‐term population persistence. Larger areas of habitat are needed to conserve greater sage‐grouse in northeastern California to accommodate seasonal movements, annual variation in habitat requirements, and to maintain connectivity between lek complexes. © 2014 The Wildlife Society.
Thermo‐mechanical couplings in elastomers – experiments and modelling
Authors: Dippel B. , Johlitz M. , Lion A.
Published: August 2014

Elastomers take an important role in many industrial applications. In the automotive industries for example, elastomers are used in various bearings, where they inhibit vibration propagation and thereby significantly enhance driving performance and comfort. Several models have been developed to simulate the material's mechanical response to various stresses and strains a component may undergo during its lifetime. So far, these models are commonly developed under isothermal conditions. In this contribution it is shown that the mechanical properties significantly depend on the temperature and that the material heats up under large dynamic deformations. Therefore, an elastomer's behaviour is not described sufficiently with an isothermal approach, a detailed thermo‐viscoelastic modelling is required. In this contribution, the behaviour of elastomers is experimentally investigated in order to gain informations about the time‐ and temperature‐dependent mechanical properties. We perform different tests on a natural rubber to emphasize the temperature dependence of the equilibrium stress‐strain relation as well as the time‐dependent behaviour in relaxation tests. As it is necessary for parameterising a material model, thermal tests are carried out to determine the specific heat capacity, the thermal expansion coefficient and the thermal conductivity. In a second step, we introduce a material model which is able to represent the temperature‐dependent viscoelastic material behaviour including large deformations, as well as the self‐heating of the material. The model's mechanical parameters are identified on tension tests. In first FE calculations, the applicability of the introduced model is proven by depicting the experimental results of several tension tests at different temperatures. Besides these validations, the self‐heating under dynamic load, depending on the loads amplitude and frequency as well as the surrounding temperature is calculated.
Ten years of the international Pompe survey: patient reported outcomes as a reliable tool for studying treated and untreated children and adults with non‐classic Pompe disease
Authors: van der Meijden J. C. , Güngör D. , Kruijshaar M. E. , Muir A. D. J. , Broekgaarden H. A. , van der Ploeg A. T.
Published: August 2014

Pompe disease is a rare, progressive lysosomal storage disorder for which enzyme therapy (ERT) became available in 2006. Four years earlier, the IPA/Erasmus MC survey, an international longitudinal prospective survey, was established to collect information on the natural course of the disease and its burden on patients. The survey is a collaboration between Erasmus MC University Medical Center and the International Pompe Association (IPA) and comprises an annual questionnaire that was specifically designed to assess the symptoms and problems of the disease. Here we review our results of over 10 years of follow‐up, and discuss the survey's contribution to the field. Tracking 408 Pompe patients between 2002 and 2013, the cumulative data reveals the broad range of clinical manifestations that interfere with patients’ lives. The survey allowed us to quantify the rate of disease progression and the positive effects of ERT on patients’ quality of life, fatigue, and participation in daily life. Furthermore, it showed for the first time that survival is reduced in adult Pompe disease and improved by ERT. Our results show that a patient survey can serve as a valuable and reliable tool for obtaining quantifiable information on the natural course of a rare disease and on the effects of therapy in a large cohort over a very long time. Most importantly, by working with patient reported outcomes, the survey provides the data that is truly relevant to the patient and complementary to clinical datasets.
Adenylosuccinate lyase deficiency
Authors: Jurecka Agnieszka , Zikanova Marie , Kmoch Stanislav , Tylki‐Szymańska Anna
Published: August 2014

Adenylosuccinate lyase ADSL) deficiency is a defect of purine metabolism affecting purinosome assembly and reducing metabolite fluxes through purine de novo synthesis and purine nucleotide recycling pathways. Biochemically this defect manifests by the presence in the biologic fluids of two dephosphorylated substrates of ADSL enzyme: succinylaminoimidazole carboxamide riboside (SAICAr) and succinyladenosine (S‐Ado). More than 80 individuals with ADSL deficiency have been identified, but incidence of the disease remains unknown. The disorder shows a wide spectrum of symptoms from slowly to rapidly progressing forms. The fatal neonatal form has onset from birth and presents with fatal neonatal encephalopathy with a lack of spontaneous movement, respiratory failure, and intractable seizures resulting in early death within the first weeks of life. Patients with type I (severe form) present with a purely neurologic clinical picture characterized by severe psychomotor retardation, microcephaly, early onset of seizures, and autistic features. A more slowly progressing form has also been described (type II, moderate or mild form), as having later onset, usually within the first years of life, slight to moderate psychomotor retardation and transient contact disturbances. Diagnosis is facilitated by demonstration of SAICAr and S‐Ado in extracellular fluids such as plasma, cerebrospinal fluid and/or followed by genomic and/or cDNA sequencing and characterization of mutant proteins. Over 50 ADSL mutations have been identified and their effects on protein biogenesis, structural stability and activity as well as on purinosome assembly were characterized. To date there is no specific and effective therapy for ADSL deficiency.
Assessment of fitness costs of resistance against the parasitoid Leptopilina victoriae in Drosophila bipectinata
Authors: Takigahira Tomohiro , Suwito Awit , Kimura Masahito T.
Published: August 2014

How insects evolve resistance or counter‐resistance against antagonists is a basic issue in the study of host‐parasitoid coevolution. One of the factors that affect their coevolution is fitness costs of resistance and counter‐resistance. Here, we assess fitness costs of resistance against the parasitoid Leptopilina victoriae in Drosophila bipectinata on the basis of selection experiments. We made a base population by mixing three geographic fly populations that differed in resistance. The established base population was divided into four populations, two for selection of resistance against a L. victoriae population and two for control. Resistance increased rapidly in response to selection and reached a very high level within four generations in the selected populations, while resistance of the control populations remained low during 20 generations. High resistance of the selected populations was maintained at least for 10 generations after selection was stopped. Both selected populations had lower female longevity than the control populations, and at least one of the selected populations had shorter thorax length, lower female desiccation tolerance and adult heat tolerance than both or either of the control populations. On the other hand, the selected populations had higher male starvation tolerance and longevity than the control populations. There were no significant differences in resistance against another population of L. victoriae and two other parasitoid species between the selected and control populations. These results suggest that the resistance against the L. victoriae population in D. bipectinata may incur some but not so high costs and act parasitoid‐species‐ and/or parasitoid‐population‐specifically.
Modern Instrumentation of the Pediatric Occiput and Upper Cervical Spine
Authors: Hedequist Daniel
Published: August 2014

Background

Rigid screw rod techniques for cervical stabilization are widely used in adults. The benefits of rigid internal fixation include increased fusion rates, improvements in deformity correction, and diminished immobilization requirements. Applications of these techniques in children are challenging due to size constraints and the pathologic conditions encountered which require instrumented cervical fusions. Preparation as well as thorough understanding of the anatomy and surgical techniques is paramount to surgical safety in pediatric patients.

Questions/Purposes

This review article serves as an educational tool regarding the use of modern posterior instrumentation techniques for pediatric cervical deformity.

Methods

Expert review based on clinical expertise and literature review.

Results

The use of rigid screw rod instrumentation for the pediatric occiput and upper cervical spine is discussed. Preoperative imaging requirements for pediatric patients undergoing cervical spine surgery are reviewed. Anatomy, morphologic studies, and surgical techniques are discussed for each area of instrumentation.

Conclusions

Modern posterior cervical instrumentation techniques can be safely applied to the majority of pediatric patients who require an instrumented posterior cervical fusion. Patient safety revolves around thorough preoperative imaging tests, understanding of upper cervical anatomy, and meticulous surgical technique. Modern instrumentation leads to an improvement in fusion rates and a diminishment in immobilization requirements.