bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of different mass spectrometry techniques in the measurement of L‐[ring‐13C6]phenylalanine incorporation into mixed muscle proteins
Authors: Zabielski Piotr , Ford G. Charles , Persson X. Mai , Jaleel Abdul , Dewey Jerry D. , Nair K. Sreekumaran
Published: February 2013

Precise measurement of low enrichment of stable isotope labeled amino‐acid tracers in tissue samples is a prerequisite in measuring tissue protein synthesis rates. The challenge of this analysis is augmented when small sample size is a critical factor. Muscle samples from human participants following an 8 h intravenous infusion of L‐[ring‐13C6]phenylalanine and a bolus dose of L‐[ring‐13C6]phenylalanine in a mouse were utilized. Liquid chromatography tandem mass spectrometry (LC/MS/MS), gas chromatography (GC) MS/MS and GC/MS were compared to the GC‐combustion‐isotope ratio MS (GC/C/IRMS), to measure mixed muscle protein enrichment of [ring‐13C6]phenylalanine enrichment. The sample isotope enrichment ranged from 0.0091 to 0.1312 molar percent excess. As compared with GC/C/IRMS, LC/MS/MS, GC/MS/MS and GC/MS showed coefficients of determination of R2 = 0.9962 and R2 = 0.9942, and 0.9217 respectively. However, the precision of measurements (coefficients of variation) for intra‐assay are 13.0%, 1.7%, 6.3% and 13.5% and for inter‐assay are 9.2%, 3.2%, 10.2% and 25% for GC/C/IRMS, LC/MS/MS, GC/MS/MS and GC/MS, respectively. The muscle sample sizes required to obtain these results were 8 µg, 0.8 µg, 3 µg and 3 µg for GC/C/IRMS, LC/MS/MS, GC/MS/MS and GC/MS, respectively. We conclude that LC/MS/MS is optimally suited for precise measurements of L‐[ring‐13C6]phenylalanine tracer enrichment in low abundance and in small quantity samples. Copyright © 2013 John Wiley & Sons, Ltd.
Studies on the metabolism and detectability of the emerging drug of abuse diphenyl‐2‐pyrrolidinemethanol (D2PM) in rat urine using GC‐MS and LC‐HR‐MS/MS
Authors: Meyer Markus R. , Schmitt Sara , Maurer Hans H.
Published: February 2013

In the last years, the number of new psychoactive substances, so‐called ‘legal highs’, has enormously increased. They are sold via online shops often with inaccurate and false information about the content. The aim of this work was to study the metabolism and the detectability of the drug of abuse diphenyl‐2‐pyrrolidinemethanol (D2PM) in rat urine using gas chromatography‐mass spectrometry and liquid chromatography‐high resolution‐tandem mass spectrometry. Five phase I and two phase II metabolites were identified suggesting hydroxylation at the pyrrolidine and diphenyl part as the main metabolic steps. Assuming similar kinetics, an intake of D2PM should be detectable in human urine mainly via its metabolites. Copyright © 2013 John Wiley & Sons, Ltd.
Fatty acid neutral losses observed in tandem mass spectrometry with collision‐induced dissociation allows regiochemical assignment of sulfoquinovosyl‐diacylglycerols
Authors: Zianni Rosalia , Bianco Giuliana , Lelario Filomena , Losito Ilario , Palmisano Francesco , Cataldi Tommaso R.I.
Published: February 2013

A full characterization of sulfoquinovosyldiacylglycerols (SQDGs) in the lipid extract of spinach leaves has been achieved using liquid chromatography/electrospray ionization‐linear quadrupole ion trap mass spectrometry (MS). Low‐energy collision‐induced dissociation tandem MS (MS/MS) of the deprotonated species [M − H]− was exploited for a detailed study of sulfolipid fragmentation. Losses of neutral fatty acids from the acyl side chains (i.e. [M − H − RCOOH]−) were found to prevail over ketene losses ([M − H − R'CHCO]−) or carboxylates of long‐chain fatty acids ([RCOO]−), as expected for gas‐phase acidity of SQDG ions. A new concerted mechanism for RCOOH elimination, based on a charge‐remote fragmentation, is proposed. The preferential loss of a fatty acids molecule from the sn‐1 position (i.e. [M − H − R1COOH]−) of the glycerol backbone, most likely due to kinetic control of the gas‐phase fragmentation process, was exploited for the regiochemical assignment of the investigated sulfolipids. As a result, 24 SQDGs were detected and identified in the lipid extract of spinach leaves, their number and variety being unprecedented in the field of plant sulfolipids. Moreover, the prevailing presence of a palmitic acyl chain (16:0) on the glycerol sn‐2 position of spinach SQDGs suggests a prokaryotic or chloroplastic path as the main route for their biosynthesis. Copyright © 2013 John Wiley & Sons, Ltd.
Development and validation of an LC‐MS/MS method for quantification of Δ9‐tetrahydrocannabinolic acid A (THCA‐A), THC, CBN and CBD in hair
Authors: Roth Nadine , Moosmann Bjoern , Auwärter Volker
Published: February 2013

For analysis of hair samples derived from a pilot study (‘in vivo’ contamination of hair by sidestream marijuana smoke), an LC‐MS/MS method was developed and validated for the simultaneous quantification of Δ9‐tetrahydrocannabinolic acid A (THCA‐A), Δ9‐tetrahydrocannabinol (THC), cannabinol (CBN) and cannabidiol (CBD). Hair samples were extracted in methanol for 4 h under occasional shaking at room temperature, after adding THC‐D3, CBN‐D3, CBD‐D3 and THCA‐A‐D3 as an in‐house synthesized internal standard. The analytes were separated by gradient elution on a Luna C18 column using 0.1% HCOOH and ACN + 0.1% HCOOH. Data acquisition was performed on a QTrap 4000 in electrospray ionization‐multi reaction monitoring mode. Validation was carried out according to the guidelines of the German Society of Toxicological and Forensic Chemistry (GTFCh). Limit of detection and lower limit of quantification were 2.5 pg/mg for THCA‐A and 20 pg/mg for THC, CBN and CBD. A linear calibration model was applicable for all analytes over a range of 2.5 pg/mg or 20 pg/mg to 1000 pg/mg, using a weighting factor 1/x. Selectivity was shown for 12 blank hair samples from different sources. Accuracy and precision data were within the required limits for all analytes (bias between −0.2% and 6.4%, RSD between 3.7% and 11.5%). The dried hair extracts were stable over a time period of one to five days in the dark at room temperature. Processed sample stability (maximum decrease of analyte peak area below 25%) was considerably enhanced by adding 0.25% lecithin (w/v) in ACN + 0.1% HCOOH for reconstitution. Extraction efficiency for CBD was generally very low using methanol extraction. Hence, for effective extraction of CBD alkaline hydrolysis is recommended. Copyright © 2013 John Wiley & Sons, Ltd.
Molecular mechanisms involved in cochlear implantation trauma and the protection of hearing and auditory sensory cells by inhibition of c‐jun‐N‐terminal kinase signaling
Authors: Eshraghi Adrien A. , Gupta Chhavi , Van De Water Thomas R. , Bohorquez Jorge E. , Garnham Carolyn , Bas Esperanza , Talamo Victoria Maria
Published: February 2013

Objectives/Hypothesis:

To investigate the molecular mechanisms involved in electrode insertion trauma (EIT) and to test the otoprotective effect of locally delivered AM‐111.

Study Design:

An animal model of cochlear implantation.

Methods:

Guinea pigs' hearing thresholds were measured by auditory brainstem response (ABR) before and after cochlear implantation in four groups: EIT; pretreated with hyaluronate gel 30 minutes before EIT (EIT+Gel); pretreated with hyaluronate gel/AM‐111 30 minutes before EIT (EIT+AM‐111); and unoperated contralateral ears as controls. Neurofilament, synapsin, and fluorescein isothiocyanate (FITC)‐phalloidin staining for hair cell counts were performed at 90 days post‐EIT. Immunostaining for 4‐hydroxy‐2‐nonenal (HNE), activated caspase‐3, CellROX, and phospho‐c‐Jun were performed at 24 hours post‐EIT.

Results:

ABR thresholds increased post‐EIT in the cochleae of EIT only and EIT+Gel treated animals. There was no significant increase in hearing thresholds in cochleae from either EIT+AM‐111 treated or unoperated control ears. AM‐111 protection of organ of Corti sensory elements (i.e., hair cells [HCs], supporting cells [SCs], nerve fibers, and synapses) was documented at 3 months post‐EIT. Immunostaining of 24‐hour post‐EIT specimens demonstrated increased levels of HNE in HCs and SCs; increased levels of CellROX and activation of caspase‐3 was observed only in SCs, and phosphorylation of c‐Jun occurred only in HCs of the EIT‐only and EIT+Gel specimens. There was no immunostaining for either HNE, CellROX, caspase‐3, or phospho‐c‐Jun in the organ of Corti specimens from AM‐111 treated cochleae.

Conclusions:

Molecular mechanisms involved in programmed cell death of HCs are different than the ones involved in programmed cell death of SCs. Local delivery of AM‐111 provided a significant level of protection against EIT‐induced hearing losses, HC losses, and damage to neural elements. Laryngoscope, 123:S1–S14, 2013
Double‐blind randomized trial on the efficacy of the Gufoni maneuver for treatment of lateral canal BPPV
Authors: Mandalà Marco , Pepponi Emanuela , Santoro Giovanni Paolo , Cambi Jacopo , Casani Augusto , Faralli Mario , Giannoni Beatrice , Gufoni Mauro , Marcelli Vincenzo , Trabalzini Franco , Vannucchi Paolo , Nuti Daniele
Published: February 2013

Objectives/Hypothesis

The need for class I and II studies on the efficacy of liberatory maneuvers in the treatment of lateral canal benign paroxysmal positional vertigo (LC‐BPPV) motivated the present double‐blind randomized trial on the short‐term efficacy of the Gufoni liberatory maneuver (GLM).

Study Design

Double‐blind randomized controlled trial.

Methods

Seventy‐two patients with unilateral LC‐BPPV were recruited for a multicentric study. Patients were randomly assigned to treatment by GLM (n = 37) or sham treatment (n = 35). Subjects were followed up twice (at 1 hour and 24 hours) with the supine roll test by blinded examiners.

Results

At 1‐ and 24‐hour follow‐up, 75.7% and 83.8% of patients, respectively, undergoing GLM had recovered from vertigo, compared to around 10% of patients undergoing the sham maneuver (P < 0.0001).

Conclusion

To the best of our knowledge, this is the first class I study on the efficacy of the GLM in the treatment of LC‐BPPV in both geotropic and apogeotropic forms. GLM proved highly effective compared to the sham maneuver (P < 0.0001). The present class I study of the efficacy of the GLM changes the level of recommendation of the method for treating LC‐BPPV from level U to level B for the geotropic variant and from level B to level A for the apogeotropic variant of LC‐BPPV.

Level of Evidence

1b. Laryngoscope, 2013
Reactive mcl‐PHA: A Sustainable Alternative for Innovative Hybrid Materials
Authors: Moraes Raul P. , Smeets Niels M. B. , McKenzie Nathalie , Zhang Ying , Kontopoulou Marianna , Ramsay Bruce , Ramsay Juliana A. , McKenna Timothy F. L.
Published: February 2013

The ability to incorporate medium chain length poly(hydroxyalkanoate) (mcl‐PHA) in the styrene miniemulsion polymerization process was investigated. As a result, novel poly(hydroxyalkanoate)‐co‐poly(stryrene) (PHA‐co‐PS) copolymers were synthesized in the form of stable organic–organic hybrid latexes. Evidence of chemical grafting of mcl‐PHA and cross‐linking of the PHA grafts was obtained using NMR, differential scanning calorimetry (DSC), gel extraction, and rheological analysis. A high degree of mcl‐PHA grafting was achieved by maintaining proper miniemulsion polymerization conditions throughout the course of the polymerization. The incorporation of PHA grafts was a function of the level of PHA in the formulations as well as the reaction conditions, as evidenced by solvent extraction and rheological analysis. DSC showed shifts in the Tg of PS towards higher temperatures, indicating chemical interaction of PS‐PHA.

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Application of sodium triple‐quantum coherence NMR spectroscopy for the study of growth dynamics in cartilage tissue engineering
Authors: Kotecha Mrignayani , Ravindran Sriram , Schmid Thomas M , Vaidyanathan Aishwarya , George Anne , Magin Richard L
Published: February 2013

We studied the tissue growth dynamics of tissue‐engineered cartilage at an early growth stage after cell seeding for four weeks using sodium triple‐quantum coherence NMR spectroscopy. The following tissue‐engineering constructs were studied: 1) bovine chondrocytes cultured in alginate beads; 2) bovine chondrocytes cultured as pellets (scaffold‐free chondrocyte pellets); and 3) human marrow stromal cells (HMSCs) seeded in collagen/chitosan based biomimetic scaffolds. We found that the sodium triple‐quantum coherence spectroscopy could differentiate between different tissue‐engineered constructs and native tissues based on the fast and slow components of relaxation rate as well as on the average quadrupolar coupling. Both fast (Tf) and slow (Ts) relaxation times were found to be longer in chondrocyte pellets and biomimetic scaffolds compared to chondrocytes suspended in alginate beads and human articular cartilage tissues. In all cases, it was found that relaxation rates and motion of sodium ions measured from correlation times were dependent on the amount of macromolecules, high cell density and anisotropy of the cartilage tissue‐engineered constructs. Average quadrupolar couplings were found to be lower in the engineered tissue compared to native tissue, presumably due to the lack of order in collagen accumulated in the engineered tissue. These results support the use of sodium triple‐quantum coherence spectroscopy as a tool to investigate anisotropy and growth dynamics of cartilage tissue‐engineered constructs in a simple and reliable way. Copyright © 2013 John Wiley & Sons, Ltd.
The safety of cefepime and ceftazidime in pediatric oncology patients
Authors: Hoffman James M. , Frediani Jamie , Herr Michael , Flynn Patricia M. , Adderson Elisabeth E.
Published: February 2013

Background

Concern has been raised about possible increased mortality associated with the use of cefepime. There are limited data available on the pragmatic use of beta‐lactam antibiotics, especially in children.

Procedure

This retrospective study included 532 pediatric oncology patients. The outcomes of patients treated with cefepime for suspected serious bacterial infections were compared to those of patients treated with ceftazidime. Primary outcomes included 30‐ and 90‐day all‐cause mortality.

Results

The demographic and clinical characteristics of 337 patients treated with ceftazidime were similar to those of 195 patients receiving cefepime. Thirty‐day and 90‐day all cause mortality rates were comparable (30‐day OR for cefepime: 3.48, 95% CI 0.31–38.84, P = 0.3; 90‐day OR: 0.99, 95% CI 0.29–3.42, P = 1.0). There were also no differences in infection‐related mortality rates, secondary infections, or adverse drug events. Deaths occurring within 30 days of hospitalization were judged to be attributable to infection, but not the result of treatment failure or adverse drug events. Deaths occurring between 30 and 90 days were associated with progressive or new malignancy. Secondary infection was significantly associated with mortality.

Conclusions

The use of cefepime in pediatric oncology patients is not associated with increased mortality when compared to ceftazidime, however the small number of deaths in this study limits the strength of this conclusion. Previous associations between antimicrobial therapy and increased all‐cause mortality may have been confounded by patients' demographic characteristics and co‐morbid conditions. All‐cause mortality may be an insensitive outcome for studies examining the efficacy and safety of these agents. Pediatr Blood Cancer 2013; 60: 806–809. © 2013 Wiley Periodicals, Inc.
Lateral shifts of waves transmitted through a medium with periodically varying permittivity and permeability
Authors: Mao Hongmin , Zang Taocheng , Sun Jian , Pan Tao , Xu Guoding
Published: February 2013

Based on the invariant imbedding method and stationary phase approximation, we perform a theoretical investigation on the lateral shifts through an inhomogeneous medium, whose permittivity and permeability are sine functions of the thickness. We find the lateral shift is large near the angles of transmissivity resonances. Furthermore, using a numerical solution method, we discuss the dependence of lateral shift on the spatial period of permittivity, the angle of incidence, the slab's thickness and the signs of the permittivity and permeability, respectively. The results show that the angles of transmissivity resonance and the lateral shifts can be easily controlled by adjusting the parameters of the structure.
Selective area growth of GaN on r‐plane sapphire by MOCVD
Authors: Rozhavskaya Mariya M. , Lundin Wsevolod V. , Nikolaev Andrey E. , Zavarin Evgeniy E. , Troshkov Sergey I. , Brunkov Pavel N. , Tsatsulnikov Andrey F.
Published: February 2013

In this study we investigate the possibility of a‐GaN ELOG process and its peculiarities for stripes of various orientations. It is shown that stripe orientation allows governing such important parameters of ELOG‐process as lateral growth rate, voids high, fast growth direction. The intermediate orientations of stripe windows (differ from conventional (0001) and (1–100)) can be effectively used for double‐cross ELOG process. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
MOVPE growth of Inx Ga1‐xN (x ∼0.5) on Si(111) substrates with a pn junction on the surface
Authors: Yamamoto A. , Mihara A. , Hironaga D. , Sugita K. , Bhuiyan A. G. , Hashimoto A. , Shigekawa N. , Watanabe N.
Published: February 2013

This paper reports the MOVPE growth of InxGa1–xN (x ∼0.5) on Si(111) with a pn junction on the surface. By optimizing growth temperature and TMI/(TMI+TEG) molar ratio, InGaN films with In content up to 0.5 are successfully grown without phase separation and metallic In incorporation. No significant differences in tilt fluctuation in grown InGaN are found among three different substrates; GaN/α–Al2O3(0001) template, p–Si(111) and n‐Si(111) with a p‐type layer on the surface. The tilt fluctuation increases with increasing In content in InGaN and shows the maximum at around In composition 0.5. The n‐InGaN/p–Si structures show good ohmic characteristics and the resistance obtained from the slope of I‐V curves is markedly reduced with increasing In content in InGaN. The Si pn junction beneath the In0.42Ga0.58N layer behaves well as a solar cell with an InGaN filter. For both n‐InGaN/p‐Si and n‐InGaN/pn‐Si structures, the presence of an AlN interlayer between the epilayer and the substrate does not have a significant contribution to the series resistance. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular beam epitaxial growth of (1 1 ‐2 2) GaN on m‐plane sapphire
Authors: Rajpalke Mohana K. , Kumar Mahesh , Roul Basanta , Bhat Thirumaleshwara N. , Krupanidhi S. B.
Published: February 2013

The structural and optical properties of semipolar (1 1 ‐2 2) GaN grown on m‐plane (1 0 ‐1 0) sapphire substrates by molecular beam epitaxy were investigated. An inplane orientation relationship was found to be [1 ‐1 0 0] GaN || [1 2‐1 0] sapphire and [‐1 ‐1 2 3] GaN || [0 0 0 1] sapphire for semipolar GaN on m‐plane sapphire substrates. The near band emission (NBE) was found at 3.432 eV, which is slightly blue shifted compared to the bulk GaN. The Raman E2 (high) peak position observed at 569.1 cm–1, which indicates that film is compressively strained. Schottky barrier height (φb) and the ideality factor (η) for the Au/ semipolar GaN Schottky diode found to be 0.55 eV and 2.11, respectively obtained from the TE model. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lin28a Regulates Germ Cell Pool Size and Fertility
Authors: Shinoda Gen , De Soysa T. Yvanka , Seligson Marc T. , Yabuuchi Akiko , Fujiwara Yuko , Huang Pei Yi , Hagan John P. , Gregory Richard I. , Moss Eric G. , Daley George Q.
Published: February 2013

Overexpression of  LIN28A  is associated with human germ cell tumors and promotes primordial germ cell (PGC) development from embryonic stem cells in vitro and in chimeric mice. Knockdown of  Lin28a  inhibits PGC development in vitro, but how constitutional  Lin28a  deficiency affects the mammalian reproductive system in vivo remains unknown. Here, we generated  Lin28a  knockout (KO) mice and found that  Lin28a  deficiency compromises the size of the germ cell pool in both males and females by affecting PGC proliferation during embryogenesis. Interestingly however, in  Lin28a  KO males, the germ cell pool partially recovers during postnatal expansion, while fertility remains impaired in both males and females mated to wild-type mice. Embryonic overexpression of  let-7, a microRNA negatively regulated by  Lin28a, reduces the germ cell pool, corroborating the role of the  Lin28a/let-7  axis in regulating the germ lineage.
Wnt and Notch Signals Guide Embryonic Stem Cell Differentiation into the Intestinal Lineages
Authors: Ogaki Soichiro , Shiraki Nobuaki , Kume Kazuhiko , Kume Shoen
Published: February 2013

The studies of differentiation of mouse or human embryonic stem cells (hESCs) into specific cell types of the intestinal cells would provide insights to the understanding of intestinal development and ultimately yield cells for the use in future regenerative medicine. Here, using an in vitro differentiation procedure of pluripotent stem cells into definitive endoderm (DE), inductive signal pathways' guiding differentiation into intestinal cells was investigated. We found that activation of Wnt/β-catenin and inhibition of Notch signaling pathways, by simultaneous application of 6-bromoindirubin-3′-oxime (BIO), a glycogen synthase kinase-3β inhibitor, and N-[(3,5-Difluorophenyl)acetyl]-L-alanyl-2-phenylglycine-1,1-dimethylethyl ester (DAPT), a known γ-secretase inhibitor, efficiently induced intestinal differentiation of ESCs cultured on feeder cell. BIO and DAPT patterned the DE at graded concentrations. Upon prolonged culture on feeder cells, all four intestinal differentiated cell types, the absorptive enterocytes and three types of secretory cells (goblet cells, enteroendocrine cells, and Paneth cells), were efficiently differentiated from mouse and hESC-derived intestinal epithelium cells. Further investigation revealed that in the mouse ESCs, fibroblast growth factor (FGF) and bone morphogenetic protein (BMP) signaling act synergistically with BIO and DAPT to potentiate differentiation into the intestinal epithelium. However, in hESCs, FGF signaling inhibited, and BMP signaling did not affect differentiation into the intestinal epithelium. We concluded that Wnt and Notch signaling function to pattern the anterior-posterior axis of the DE and control intestinal differentiation.
Imaging high stage river‐water intrusion into a contaminated aquifer along a major river corridor using 2‐D time‐lapse surface electrical resistivity tomography
Authors: Wallin E. L. , Johnson T. C. , Greenwood W. J. , Zachara J. M.
Published: February 2013

Key Points

Inland high‐stage river water intrusion is imaged using time‐lapse ERT.

Transient water‐table elevation constraints enable accurate imaging.

River water intrusion is dominated by preferred flow pathways.
Urapidil in the Preoperative Treatment of Pheochromocytomas: A Safe and Cost‐effective Method
Authors: Habbe Nils , Ruger Florian , Bojunga Jorg , Bechstein Wolf Otto , Holzer Katharina
Published: February 2013

Background

Surgery for pheochromocytoma may lead to uncontrolled catecholamine secretion with severe hypertension and cardiac failure. Perioperative α1‐receptor‐blockade with orally administered phenoxybenzamine or intravenous urapidil therefore is a standard procedure in the treatment regime prior to surgery.

Methods

Medical records of 30 patients who underwent surgery for pheochromocytoma during the years 2002–2011 were retrospectively analyzed. We investigated the difference in the clinical course of patients undergoing surgery for pheochromocytoma with either phenoxybenzamine or urapidil pretreatment with special regard to the intraoperative course and length of hospital stay and costs.

Results

Nineteen (16 female, 3 male) patients (63 %) received a preoperative α‐block with orally administered phenoxybenzamine. Eleven patients (6 female, 5 male) (37 %) were treated with intravenous urapidil for 3 days prior to surgery. Intraoperative episodes of hypertension or hypotension did not differ significantly. The median total hospital stay in phenoxybenzamine‐treated patients was 17 days in contrast to 11 days in the urapidil group (p = 0.0087). Patients who received i.v. pretreatment spent significantly fewer days in the hospital prior to operation [median: 3 days (range: 3–7 days) versus 9 days (range: 3–21 days); p = 0.0001]. The reduction in the number of days in the hospital in the urapidil group led to a significantly elevated revenue per day (€637.49/day versus €412.50/day; p = 0.001).

Conclusions

Perioperative treatment with the selective α1 blocker urapidil remains a simple and cost effective method in the treatment regime of patients with pheochromocytoma.
Observed-Score Equating: An Overview
Authors: von Davier Alina A.
Published: February 2013

In this paper, an overview of the observed-score equating (OSE) process is provided from the perspective of a unifying equating framework (von Davier in von Davier (Ed.), Statistical models for test equating, scaling, and linking, Springer, New York, pp. 1–17, 2011b). The framework includes all OSE approaches. Issues related to the test, common items, and sampling designs and their relationship to measurement and equating are discussed. Challenges to the equating process, model assumptions, and approaches to equating evaluation are also presented. The equating process is illustrated step-by-step with a real data example from a licensure test.
Barriers to the use of evidence-based medicine: knowledge and skills, attitude, and
external factors
Authors: Zwolsman Sandra E. , Van Dijk Nynke , Te Pas Ellen , Wieringa-de Waard Margreet
Published: February 2013

Although efforts are made to integrate evidence-based medicine (EBM) into clinical
practice, physicians experience significant barriers to its implementation. The aim of
this study is to quantify the barriers that general practice (GP) trainees experience
when using EBM in practice. In September 2008, a questionnaire was administered to
140 GP trainees from three Dutch GP Speciality Training Institutes. The questionnaire
focused on barriers that GP trainees meet when using EBM in practice. Factor analysis
identified components in which barriers exist, and the validity and reliability of the
questionnaire were established. After removing four items that did not fit the
questionnaire structure, factor analysis identified three relevant components. All three
components had similar mean scores, indicating a similar negative influence of these
components on the practice of EBM: knowledge/skills (α = 0.72, mean score 2.9 ± 0.8),
attitude (α = 0.70, mean score 2.9 ± 0.6), and external factors (α = 0.66, mean score
3.0 ± 0.5). The barrier that trainees experienced most was lack of time to practise EBM.
Barriers to the use of EBM were present in three components: knowledge/skills, attitude,
and external factors.
Irreversible inactivation of snake venom l‐amino acid oxidase by covalent modification during catalysis of l‐propargylglycine
Authors: Mitra Jyotirmoy , Bhattacharyya Debasish
Published: February 2013

Snake venom l‐amino acid oxidase (SV‐LAAO, a flavor‐enzyme) has attracted considerable attention due to its multifunctional nature, which is manifest in diverse clinical and biological effects such as inhibition of platelet aggregation, induction of cell apoptosis and cytotoxicity against various cells. The majority of these effects are mediated by H2O2 generated during the catalytic conversion of l‐amino acids. The substrate analog l‐propargylglycine (LPG) irreversibly inhibited the enzyme from Crotalus adamanteus and Crotalus atrox in a dose‐ and time‐dependent manner. Inactivation was irreversible which was significantly protected by the substrate l‐phenylalanine. A Kitz–Wilson replot of the inhibition kinetics suggested formation of reversible enzyme–LPG complex, which occurred prior to modification and inactivation of the enzyme. UV–visible and fluorescence spectra of the enzyme and the cofactor strongly suggested formation of covalent adduct between LPG and an active site residue of the enzyme. A molecular modeling study revealed that the FAD‐binding, substrate‐binding and the helical domains are conserved in SV‐LAAOs and both His223 and Arg322 are the important active site residues that are likely to get modified by LPG. Chymotrypsin digest of the LPG inactivated enzyme followed by RP‐HPLC and MALDI mass analysis identified His223 as the site of modification. The findings reported here contribute towards complete inactivation of SV‐LAAO as a part of snake envenomation management.
Erfolgskriterien für die indikationsbezogene Integrierte Versorgung
Authors: Amelung Volker E. , Wolf Sascha
Published: February 2013

Einleitung

In der gesundheitspolitischen Diskussion steht die indikationsbezogene Integrierte Versorgung zumeist im Schatten von populationsorientierten Vollversorgungsprojekten. In der praktischen Umsetzung besitzen erstere jedoch erhebliche Vorteile: Behandlungsleitlinien können leichter entwickelt sowie Qualität und Kosten einfacher evaluiert werden. In der Versorgungsrealität sind es daher oftmals gerade die indikationsbezogenen Modelle, die auch in der Breite zu einer Verbesserung der medizinischen Versorgung beispielsweise von chronisch Kranken beitragen. Inzwischen ist das Angebot besonderer Versorgungsformen zu einem wichtigen Wettbewerbsinstrument der Krankenkassen geworden.
Maternal enhancement of cytotype regulation inDrosophila melanogasterby genetic interactions between telomericPelements and non-telomeric transgenicPelements
Authors: SIMMONS MICHAEL J. , RAGATZ LISA M. , SINCLAIR IAN R. , THORP MICHAEL W. , BUSCHETTE JARED T. , GRIMES CRAIG D.
Published: February 2013

The X-linked telomericPelements (TPs)TP5andTP6regulate the activity of the entirePelement family because they are inserted in a major locus for the production of Piwi-interacting RNAs (piRNAs). The potential for this cytotype regulation is significantly strengthened when eitherTP5orTP6is combined with a non-telomeric X-linked or autosomal transgene that contains aPelement. By themselves, none of the transgenicPelements have any regulatory ability. Synergism between the telomeric and transgenicPelements is much greater when the TP is derived from a female. Once an enhanced regulatory state is established in a female, it is transmitted to her offspring independently of either the telomeric or transgenicPelements – that is, it works through a strictly maternal effect. Synergistic regulation collapses when either the telomeric or the transgenicPelement is removed from the maternal genotype, and it is significantly impaired when the TPs come from stocks heterozygous for mutations in the genesaubergine,piwiorSu(var)205. The synergism between telomeric and transgenicPelements is consistent with a model in whichPpiRNAs are amplified by alternating, or ping-pong, targeting of primary piRNAs to sense and antisensePtranscripts, with the sense transcripts being derived from the transgenicPelement and the antisense transcripts being derived from the TP.
Estimation of breeding values for mean and dispersion, their variance and correlation using double hierarchical generalized linear models
Authors: FELLEKI M. , LEE D. , LEE Y. , GILMOUR A. R. , RÖNNEGÅRD L.
Published: February 2013

The possibility of breeding for uniform individuals by selecting animals expressing a small response to environment has been studied extensively in animal breeding. Bayesian methods for fitting models with genetic components in the residual variance have been developed for this purpose, but have limitations due to the computational demands. We use the hierarchical (h)-likelihood from the theory of double hierarchical generalized linear models (DHGLM) to derive an estimation algorithm that is computationally feasible for large datasets. Random effects for both the mean and residual variance parts of the model are estimated together with their variance/covariance components. An important feature of the algorithm is that it can fit a correlation between the random effects for mean and variance. An h-likelihood estimator is implemented in the R software and an iterative reweighted least square (IRWLS) approximation of the h-likelihood is implemented using ASReml. The difference in variance component estimates between the two implementations is investigated, as well as the potential bias of the methods, using simulations. IRWLS gives the same results as h-likelihood in simple cases with no severe indication of bias. For more complex cases, only IRWLS could be used, and bias did appear. The IRWLS is applied on the pig litter size data previously analysed by Sorensen & Waagepetersen (2003) using Bayesian methodology. The estimates we obtained by using IRWLS are similar to theirs, with the estimated correlation between the random genetic effects being −0·52 for IRWLS and −0·62 in Sorensen & Waagepetersen (2003).
First detection of Alaria alata mesocercariae in wild boars (Sus scrofa Linnaeus, 1758) from Bulgaria
Authors: Riehn K. , Lalkovski N. , Hamedy A. , Lücker Ernst
Published: February 2013

The trematode Alaria alata, an intestinal parasite of different carnivore species is widely distributed throughout Europe. The mesocercarial stages of Alaria spp. may infect almost all vertebrate species, including humans, and, in particular, omnivorous scavengers such as wild boars serve as paratenic hosts for the parasite. The introduction of the A. alata mesocercariae migration technique (AMT) opened the way to a reliable detection of Alaria spp. mesocercariae in different body tissues of their paratenic hosts. For the first time, it was possible to detect vital A. alata mesocercariae from two Bulgarian wild boars by means of this new method. In addition, polymerase chain reaction (PCR) examination of the respective parasitic DNA allowed the unequivocal species identification of the parasites as A. alata. Isolation and molecular biological identification of the parasite's developmental stages make significant contributions to completion of data on both the distribution of Alaria spp. in stocks of European game and the relationship between different Eurasian Alaria spp. isolates.
Key methods of identifying the horizontal facial nerve during difficult middle-ear surgery
Authors: Syed M I , Madurska M , O'Reilly B F
Published: February 2013

Background:

The key to avoiding damage to the horizontal facial nerve in middle-ear surgery is to formally identify the nerve in the early stages of the procedure.

Methods:

In the non-infected ear this can be achieved relatively easily by identifying the oval window niche. However, in the infected ear with cholesteatoma, the safest landmark to use is the processus cochleariformis, which can be identified by three different methods.

Conclusion:

In an infected ear that is full of granulation tissue and/or cholesteatoma, the horizontal facial nerve can be reliably identified by locating the processus cochleariformis using the three methods described. This avoids damage to the nerve and important structures around it.
THE CASE AGAINST THE CASE AGAINST RECASTS
Authors: Goo Jaemyung , Mackey Alison
Published: February 2013

In the previous 20 years, more than 60 studies have been carried out within the input and interaction approach to SLA (Long, 2007; Mackey 2012), many of which have found positive associations between different types of recasts and the learning of a range of linguistic forms for a number of different second languages (L2s), in different learning contexts, with adults and with children. However, the following claims also appear: (a) recasts are not effective, (b) recasts are effective only in laboratories and not in classrooms, and (c) other types of feedback are more effective when compared with recasts. We demonstrate important methodological and interpretative problems in the small number of studies on which these negative claims are based, including issues with (a) modified output opportunities, (b) single-versus-multiple comparisons, (c) form-focused instruction, (d) prior knowledge, and (e) out-of-experiment exposure. We conclude by suggesting that making a case against recasts is neither convincing nor useful for advancing the field and that more triangulated approaches to research on all types of corrective feedback, employing varied and rigorous methodological designs, are necessary to further our understanding of the role of corrective feedback in L2 learning.
Kant, the State, and Revolution
Authors: Maliks Reidar
Published: February 2013

This paper argues that, although no resistance or revolution is permitted in the Kantian state, very tyrannical regimes must not be obeyed because they do not qualify as states. The essay shows how a state ceases to be a state, argues that persons have a moral responsibility to judge about it and defends the compatibility of this with Kantian authority. The reconstructed Kantian view has implications for how we conceive authority and obligation. It calls for a morally demanding definition of the state and asserts that the primary personal responsibility is not to evaluate the morality of every single law but to evaluate the moral standing of the polity.
Freedom, Knowledge and Affection: Reply to Hogan
Authors: Stang Nicholas
Published: February 2013

In a recent paper, Desmond Hogan aims to explain how Kant could have consistently held that noumenal affection is not only compatible with noumenal ignorance (the doctrine that we have no knowledge of things in themselves) but also with the claim that experience requires causal affection of human cognitive agents by things in themselves. Hogan's argument includes the premise that human cognitive agents have empirical knowledge of one another's actions. Hogan's argument fails because the premise that we have empirical knowledge of one another's actions is ambiguous. On one reading, the argument is valid but its conclusion trivial. On the other, it is unsound on Kant's own view.
Grain Boundary Character Distribution of Nanocrystalline Cu Thin Films Using Stereological Analysis of Transmission Electron Microscope Orientation Maps
Authors: Darbal A.D. , Ganesh K.J. , Liu X. , Lee S.-B. , Ledonne J. , Sun T. , Yao B. , Warren A.P. , Rohrer G.S. , Rollett A.D. , Ferreira P.J. , Coffey K.R. , Barmak K.
Published: February 2013

Stereological analysis has been coupled with transmission electron microscope (TEM) orientation mapping to investigate the grain boundary character distribution in nanocrystalline copper thin films. The use of the nanosized (<5 nm) beam in the TEM for collecting spot diffraction patterns renders an order of magnitude improvement in spatial resolution compared to the analysis of electron backscatter diffraction patterns in the scanning electron microscope. Electron beam precession is used to reduce dynamical effects and increase the reliability of orientation solutions. The misorientation distribution function shows a strong misorientation texture with a peak at 60°/[111], corresponding to the Σ3 misorientation. The grain boundary plane distribution shows {111} as the most frequently occurring plane, indicating a significant population of coherent twin boundaries. This study demonstrates the use of nanoscale orientation mapping in the TEM to quantify the five-parameter grain boundary distribution in nanocrystalline materials.
Intravital Confocal and Two-Photon Imaging of Dual-Color Cells and Extracellular Matrix Mimics
Authors: Bal Ufuk , Andresen Volker , Baggett Brenda , Utzinger Urs
Published: February 2013

We report our efforts in identifying optimal scanning laser microscope parameters to study cells in three-dimensional culture. For this purpose we studied contrast of extracellular matrix (ECM) mimics, as well as signal attenuation, and bleaching of red and green fluorescent protein labeled cells. Confocal backscattering, second harmonic generation (SHG), and autofluorescence were sources of contrast in ECM mimics. All common ECM mimics exhibit contrast observable with confocal reflectance microscopy. SHG imaging on collagen I based hydrogels provides high contrast and good optical penetration depth. Agarose is a useful embedding medium because it allows for large optical penetration and exhibits minimal autofluorescence. We labeled breast cancer cells' outline with DsRed2 and nucleus with enhanced green fluorescent protein (eGFP). We observed significant difference both for the bleaching rates of eGFP and DsRed2 where bleaching is strongest during two-photon excitation (TPE) and smallest during confocal imaging. But for eGFP the bleaching rate difference is smaller than for DsRed2. After a few hundred microns depth in a collagen I hydrogel, TPE fluorescence of DsRed2 becomes twice as strong compared to confocal imaging. In fibrin and agarose gels, the imaging depth will need to be beyond 1 mm to notice a TPE advantage.
Teaching, learning and assessment of undergraduate radiography students: a strategy to develop progression towards competency
Authors: Chianese J. , Channon B.
Published: February 2013

A new clinical teaching, learning and assessment strategy for radiotherapy and diagnostic imaging undergraduates was developed by action research. Outcome-based competencies were used together with other strategies to progress students' learning through successive levels with the aim of developing essential and desirable attributes of the respective professions. The planning team consisted of academic and clinical staff resulting in a shared project. Specific outcomes for each profession were devised by subgroups of the original team. The radiotherapy scheme implemented formative staged outcomes and the report focuses mainly on this strategy. Evaluation reveals that discriminations can be made at an early stage between those students achieving and those who are not. Highlighting specific areas for improvement allows opportunities for remedial work and creation of individual action plans. Key clinical staff underwent specific training to facilitate students' development and act as effective gatekeepers to progression. Recommendations for further research are to survey graduates now in employment to investigate how well they feel the scheme has fitted them for practice. There is also the potential to survey those who left the course prior to completion to discover if the scheme has helped to develop transferable skills for life long learning.
On the cubic NLS on 3D compact domains
Authors: Planchon Fabrice
Published: February 2013

We prove bilinear estimates for the Schrödinger equation on 3D domains, with Dirichlet boundary conditions. On non-trapping domains, they match the ${ \mathbb{R} }^{3} $ case, while on bounded domains they match the generic boundaryless manifold case. We obtain, as an application, global well-posedness for the defocusing cubic NLS for data in ${ H}_{0}^{s} (\Omega )$, $1\lt s\leq 3$, with $\Omega $ any bounded domain with smooth boundary.
Changing Minds: A Psychodynamic Interpretation of Kuhnian Paradigm Change
Authors: Elad-Strenger Julia
Published: February 2013

Thomas Kuhn's model of the structure of scientific revolutions is, to this day, one of the most influential attempts to understand central processes in the history of science. While Kuhn coached his theory in historical and sociological terms, this article argues that modern existential psychology can be used to add a psychodynamic dimension to Kuhn's model. Specifically, while Kuhn famously claimed that scientific paradigms are worldviews held by scientists and described their pattern of change, terror management theory (TMT) emphasizes the existential importance of worldviews and specifies the conditions under which individuals will either radicalize or abandon their worldviews when they are faced with threat or negative evidence. This article shows that the stages Kuhn describes in the history of science can fruitfully be elucidated by central TMT concepts, and exemplifies their applicability through two examples in the history of psychology. The resulting psychological interpretation of scientists' existential attachment to their worldview might prove fruitful in understanding crucial dynamics in the history of science.
A Single Unexpected Change in Target- but Not Distractor Motion Impairs Multiple Object Tracking
Authors: Meyerhoff Hauke S. , Papenmeier Frank , Jahn Georg , Huff Markus
Published: February 2013

Recent research addresses the question whether motion information of multiple objects contributes to maintaining a selection of objects across a period of motion. Here, we investigate whether target and/or distractor motion information is used during attentive tracking. We asked participants to track four objects and changed either the motion direction of targets, the motion direction of distractors, neither, or both during a brief flash in the middle of a tracking interval. We observed that a single direction change of targets is sufficient to impair tracking performance. In contrast, changing the motion direction of distractors had no effect on performance. This indicates that target- but not distractor motion information is evaluated during tracking.
Radical Cascade Protocol for the Synthesis of (5'S)- and (5'R)-5',8-Cyclo-2'-deoxyguanosine Derivatives
Authors: Terzidis Michael A. , Chatgilialoglu Chryssostomos
Published: February 2013

The reaction of the appropriately substituted 8-bromo-2′-deoxyguanosine with Bu3SnH/2,2′-azobisisobutyronitrile (AIBN) can be favourably tuned to give the analogous 5′,8-cyclo-2′-deoxyguanosine derivatives in good yields, thus providing easy access to modified nucleosides that constitute an important DNA lesion. A large excess of AIBN is necessary. The creation of the new C5′–C8 bond is a non-chain radical cascade protocol.
Towards cost-effective estimation of soil carbon stocks at the field scale
Authors: Singh K. , Murphy B. W. , Marchant B. P.
Published: February 2013

Accurate estimates of soil carbon stocks at the field scale are required to run market-based instruments for soil carbon, but the soil measurements required to make these estimates are expensive. Therefore, efficient sample designs are required. We explored the costs associated with estimating the mean soil carbon stocks within a 68-ha field on the old alluvial soils of the Macquarie River in central-west New South Wales (Red Chromosols or Red Luvisols). The sampling required to achieve a particular degree of accuracy depends upon the variability of soil carbon within the field. We conducted a 100-site geostatistical survey to estimate the variogram of soil carbon. We then used this variogram to consider the efficiency with which simple random and stratified sample designs can achieve a standard error <2 t/ha for the mean carbon stock to 30 cm. The stratifications considered were either purely spatial or based upon auxiliary information such as landform or sensor data. The effectiveness of localised clustering or quadrats within designs was also considered. Formulae were devised to determine the costs of implementing the different designs, based upon our experience from conducting the geostatistical survey. Only weak correlations between carbon stocks and the auxiliary information were evident, and hence the stratifications were largely ineffective. Some benefits of using quadrats were evident, since analytical and field survey costs were reduced. However, the cost (AU$2500) required to achieve the target accuracy is still considerable. The sampled field has complex pedology, and we therefore expect that these costs are larger than average. Similar studies are required to calculate sampling requirements in different locations and to determine whether these requirements can be related to factors such as soil type, parent material, or land management history.