bluuebunny/crossref_metadata_2025 huggingface dataset:
Copying of RNA Sequences without Pre‐Activation
Authors: Jauker Mario , Griesser Helmut , Richert Clemens
Published: October 2015

Template‐directed incorporation of nucleotides at the terminus of a growing complementary strand is the basis of replication. For RNA, this process can occur in the absence of enzymes, if the ribonucleotides are first converted to an active species with a leaving group. Thus far, the activation required a separate chemical step, complicating prebiotically plausible scenarios. Here we show that a combination of a carbodiimide and an organocatalyst induces near‐quantitative incorporation of any of the four ribonucleotides. Upon in situ activation, adenosine monophosphate was found to also form oligomers in aqueous solution. So, both de novo strand formation and sequence‐specific copying can occur without an artificial synthetic step.
Spontaneous Formation of RNA Strands, Peptidyl RNA, and Cofactors
Authors: Jauker Mario , Griesser Helmut , Richert Clemens
Published: October 2015

How the biochemical machinery evolved from simple precursors is an open question. Here we show that ribonucleotides and amino acids condense to peptidyl RNAs in the absence of enzymes under conditions established for genetic copying. Untemplated formation of RNA strands that can encode genetic information, formation of peptidyl chains linked to RNA, and formation of the cofactors NAD+, FAD, and ATP all occur under the same conditions. In the peptidyl RNAs, the peptide chains are phosphoramidate‐linked to a ribonucleotide. Peptidyl RNAs with long peptide chains were selected from an initial pool when a lipophilic phase simulating the interior of membranes was offered, and free peptides were released upon acidification. Our results show that key molecules of genetics, catalysis, and metabolism can emerge under the same conditions, without a mineral surface, without an enzyme, and without the need for chemical pre‐activation.
Synthesis of a Series of Zinc Porphyrins and Spectroscopic Changes upon Coordination Reaction with Imidazole Derivatives
Authors: Wang Shu‐Jun , Peng Yu‐Ling , Zhang Cheng‐Gen , Li Yong‐Bing , Liu Chao
Published: October 2015

Three metal‐free porphyrins modified with Boc‐l‐threonine and their zinc analogs were synthesized and characterized by elemental analysis,
1H NMR, UV/vis, and fluorescence spectroscopies. The binding of imidazole derivatives to these zinc porphyrins was studied, with emphasis on the binding mechanism in CH2Cl2
solution, by means of UV/vis spectroscopy and quantum chemical methods. Both experimental results and theoretical calculations showed that a coordination reaction occurred between the zinc porphyrins and imidazole derivatives. The association constants between the zinc porphyrins and imidazole derivatives decreased in the order N‐MeIm>Im. Increasing the temperature disfavored the interaction. Thermodynamic parameters calculated by the van't Hoff equation showed that the driving force for the reaction was the enthalpy change. The fluorescence changes associated with the interaction between the zinc porphyrins and imidazole derivatives were also studied by fluorescence spectroscopy. The experimental results showed significant quenching between the various zinc porphyrins and imidazole derivatives.
Dual Lewis Acidic/Basic Pd0.5Ru0.5–Poly(N‐vinyl‐2‐pyrrolidone) Alloyed Nanoparticle: Outstanding Catalytic Activity and Selectivity in Suzuki–Miyaura Cross‐Coupling Reaction
Authors: Kutubi Md. Shahajahan , Sato Katsutoshi , Wada Kenji , Yamamoto Tomokazu , Matsumura Syo , Kusada Kohei , Kobayashi Hirokazu , Kitagawa Hiroshi , Nagaoka Katsutoshi
Published: October 2015

This article anticipates the development of dual Lewis acidic/basic alloyed nanoparticle (NP) of poly(N‐vinyl‐2‐pyrrolidone)‐stabilized Pd0.5Ru0.5 solid solution, revealing equivalent Pdδ+ and Ruδ− on the NP surface. This unsupported NP disclosed excellent catalytic efficiency with high turnover frequency, 15 000 h−1 in Suzuki–Miyaura cross‐coupling under notable drop of both Pd loading (0.08 mol %) and time (5 min) in air, attributed for its bifunctional acidic/basic modes. The bifunctional modes exposed the most interesting new reaction mechanism ascribed by the inductive effects of p‐substituents in arylboronic acid, accelerated reactivity by electron‐withdrawing group, revealing an opposite reactivity trend relative to other Pd‐based catalysts. Besides, the significant drops of Pd loading and reaction time impeded the metal leaching associated with no changes in NP surface composition/structure after the 3rd cycle (>99 % efficiency), revealing a line‐up for this NP in the environmental sustainability.
Thermomechanical Treatment of Metal Composite Fractions
Authors: Rotheut Martin , Horst Thomas , Quicker Peter
Published: October 2015

The investigation focuses on shredder light fractions, electrical waste, and metal concentrates from landfills that can be treated mechanically only with difficulty. The fractions were input to a combined thermomechanical treatment to procure a high degree of composite component separation. Suitable process parameters were identified and the respective treatment outcomes evaluated. Overall, it was possible to verify the basic suitability of the thermomechanical treatment of metal‐rich composite mixtures for recovering the metals contained.
Reductive Smelting of Red Mud for Iron Recovery
Authors: Kaußen Frank , Friedrich Bernd
Published: October 2015

The reductive smelting of red mud is calculated and investigated regarding the necessary amount of reduction agents and the final composition of the pig iron phase and the mineral (slag) phase as products of the process. Liquidus temperatures of slags with three different compositions are calculated during the reduction process and in dependency of the remaining sodium content in the slag. All calculations were done with FactSage and the results are confirmed by smelting experiments in a lab scale electric arc furnace.
Experiments and a three‐phase computational fluid dynamics (CFD) simulation coupled with population balance equations of a stirred tank bioreactor for high cell density cultivation
Authors: Azargoshasb Hamidreza , Mousavi Seyyed Mohammad , Jamialahmadi Oveis , Shojaosadati Seyed Abbas , Mousavi Seyyed Babak
Published: October 2015

This research describes a three dimensional (3‐D) computational fluid dynamics (CFD) simulation coupled with population balance equations (PBE) to study hydrodynamics and biomass production in a laboratory‐scale stirred‐tank bioreactor. The gas‐liquid‐solid flow was modelled using a Eulerian multiphase and turbulence (RNG) model. The energy dissipation rates, gas holdup, flow patterns, Sauter mean bubble diameter, and volumetric mass transfer coefficient were investigated for three different types of impeller using a multiple reference frame (MRF) model within the whole multiphase bioreactor. The effects of aeration rate and impeller speed on gas holdup and volumetric mass transfer coefficient were investigated owing to oxygen limitation in high cell density cultivation (HCDC). As high viscosity puts a limit on the efficiency of the bioreactor, the influences of viscosity on Sauter mean diameter, gas holdup, and volumetric mass transfer coefficient were also assessed. To determine growth kinetics as well as gas holdup, a set of experiments was performed. The numerical results of gas holdup and kLa were compared with the experimental data. Obtained results suggest that the Scaba impeller results in higher values of volumetric mass transfer coefficient, and subsequently higher biomass concentrations. One of the greatest problems in HCDC is feed accumulation in particular places. As depletion of substrate occurs near the impeller, the best spot for feeding purposes is in the vicinity of the impeller. Current research gives insight into the determination of the optimal operating conditions of HCDC in stirred bioreactors.
Propargylated novolac resins for fibre‐reinforced plastics: Processing aspects
Authors: Bulgakov Boris , Kalugin Denis , Babkin Alexander , Makarenko Irina , Malakho Artem , Kepman Alexey , Avdeev Victor , Garadja Nikita , Rogozin Alexey
Published: October 2015

Propargylated novolac resins (PN) are known polymer binders for fibre‐reinforced plastic production. Unlike common phenolic resins, PNs are able to cure without volatiles, avoiding porosity formation in the final material. Otherwise, PN curing proceeds with a high exothermal effect (up to 1200 J/g), causing overheating that may result in destruction of material and equipment damage. The specific heat release limit was found with a curing kinetic study complemented with mathematical calculations to be 660 J/g for a quick and safe moulding process. A new commercially‐available catalyst for PN curing based on Ni(II) salts is recommended for composite pressing. Use of this catalyst helps to spread exothermal effects and simplify the curing process. It was shown that by varying reaction conditions, it is possible to adjust material properties such as Tg, char yield, curing temperature, and processing time.
Body size but not warning signal luminance influences predation risk in recently metamorphosed poison frogs
Authors: Flores Eric E. , Stevens Martin , Moore Allen J. , Rowland Hannah M. , Blount Jonathan D.
Published: October 2015

During early development, many aposematic species have bright and conspicuous warning appearance, but have yet to acquire chemical defenses, a phenotypic state which presumably makes them vulnerable to predation. Body size and signal luminance in particular are known to be sensitive to variation in early nutrition. However, the relative importance of these traits as determinants of predation risk in juveniles is not known. To address this question, we utilized computer‐assisted design (CAD) and information on putative predator visual sensitivities to produce artificial models of postmetamorphic froglets that varied in terms of body size and signal luminance. We then deployed the artificial models in the field and measured rates of attack by birds and unknown predators. Our results indicate that body size was a significant predictor of artificial prey survival. Rates of attack by bird predators were significantly higher on smaller models. However, predation by birds did not differ between artificial models of varying signal luminance. This suggests that at the completion of metamorphosis, smaller froglets may be at a selective disadvantage, potentially because predators can discern they have relatively low levels of chemical defense compared to larger froglets. There is likely to be a premium on efficient foraging, giving rise to rapid growth and the acquisition of toxins from dietary sources in juvenile poison frogs.
The controversial existence of the human superior fronto‐occipital fasciculus: Connectome‐based tractographic study with microdissection validation
Authors: Meola Antonio , Comert Ayhan , Yeh Fang‐Cheng , Stefaneanu Lucia , Fernandez‐Miranda Juan C.
Published: October 2015

The superior fronto‐occipital fasciculus (SFOF), a long association bundle that connects frontal and occipital lobes, is well‐documented in monkeys but is controversial in human brain. Its assumed role is in visual processing and spatial awareness. To date, anatomical and neuroimaging studies on human and animal brains are not in agreement about the existence, course, and terminations of SFOF. To clarify the existence of the SFOF in human brains, we applied deterministic fiber tractography to a template of 488 healthy subjects and to 80 individual subjects from the Human Connectome Project (HCP) and validated the results with white matter microdissection of post‐mortem human brains. The imaging results showed that previous reconstructions of the SFOF were generated by two false continuations, namely between superior thalamic peduncle (STP) and stria terminalis (ST), and ST and posterior thalamic peduncle. The anatomical microdissection confirmed this finding. No other fiber tracts in the previously described location of the SFOF were identified. Hence, our data suggest that the SFOF does not exist in the human brain. Hum Brain Mapp 36:4964–4971, 2015. © 2015 Wiley Periodicals, Inc.
Measuring Communication Skills: The STEM Interpersonal Communication Skills Assessment Battery
Authors: Wilkins Kerrie G. , Bernstein Bianca L. , Bekki Jennifer M.
Published: October 2015

Background

Effective interpersonal communication skills in the advisor‐advisee relationship context are important to the success of graduate students. Few instruments have previously been developed to assess students' communication skills in this context.

Purpose/Hypothesis

This study reports the development and validation of the Science, Technology, Engineering, and Math Interpersonal Communication Skills Assessment Battery (STEM ICSAB) for women doctoral students in engineering, mathematics, computer sciences, and the physical sciences. The STEM ICSAB consists of three instruments: the Interpersonal Communication Knowledge Assessment, Interpersonal Communication Coping Self‐Efficacy Assessment, and the Interpersonal Communication Skills Assessment.

Design/Method

The STEM ICSAB was developed in three stages. Stage I consisted of item generation and establishment of content validity. In Stage II, an exploratory analysis with a convenience sample of undergraduate and graduate students determined the initial factor structure of each instrument. In Stage III, a confirmatory factor analysis with a sample of women doctoral students further examined the factor structures derived from Stage II.

Results

The Knowledge assessment has 20 items, the Coping Self‐Efficacy assessment has 12 items, and the Skills assessment has five items. All three measures fit a unidimensional factor structure and demonstrate moderate to high internal consistency.

Conclusion

This study provides initial support for the psychometric properties of the STEM ICSAB. Use of the STEM ICSAB will improve opportunities for women doctoral students to learn, practice, and improve critical interpersonal communication skills.
Analysis‐preserving video microscopy compression via correlation and mathematical morphology
Authors: Shao Chong , Zhong Alfred , Cribb Jeremy , Osborne Lukas D. , O'Brien E. Timothy , Superfine Richard , Mayer‐Patel Ketan , Taylor Russell M.
Published: October 2015

The large amount video data produced by multi‐channel, high‐resolution microscopy system drives the need for a new high‐performance domain‐specific video compression technique. We describe a novel compression method for video microscopy data. The method is based on Pearson's correlation and mathematical morphology. The method makes use of the point‐spread function (PSF) in the microscopy video acquisition phase. We compare our method to other lossless compression methods and to lossy JPEG, JPEG2000, and H.264 compression for various kinds of video microscopy data including fluorescence video and brightfield video. We find that for certain data sets, the new method compresses much better than lossless compression with no impact on analysis results. It achieved a best compressed size of 0.77% of the original size, 25× smaller than the best lossless technique (which yields 20% for the same video). The compressed size scales with the video's scientific data content. Further testing showed that existing lossy algorithms greatly impacted data analysis at similar compression sizes. Microsc. Res. Tech. 78:1055–1061, 2015. © 2015 Wiley Periodicals, Inc.
Synthesis of Novel Tetrazole Containing Quinoline and 2,3,4,9‐Tetrahydro‐1H‐β‐Carboline Derivatives
Authors: Ghandi Mehdi , Rahimi Shahnaz , Zarezadeh Nahid
Published: October 2015

This presentation describes the successful synthesis of novel tetrazole‐based quinoline and tetrahydro‐1H‐β‐carboline derivatives via one‐pot multicomponent reactions in moderate to good yields. These reactions have presumably proceeded through Ugi‐azide or Ugi‐azide/Pictet–Spengler processes, respectively.
An evaluation of physician predictions of discharge on a general medicine service
Authors: Sullivan Brian , Ming David , Boggan Joel C. , Schulteis Ryan D. , Thomas Samantha , Choi Josh , Bae Jonathan
Published: October 2015

The goal of this study was to evaluate general medicine physicians' ability to predict hospital discharge. We prospectively asked study subjects to predict whether each patient under their care would be discharged on the next day, on the same day, or neither. Discharge predictions were recorded at 3 time points: mornings (7–9 am), midday (12–2 pm), or afternoons (5–7 pm), for a total of 2641 predictions. For predictions of next‐day discharge, the sensitivity (SN) and positive predictive value (PPV) were lowest in the morning (27% and 33%, respectively), but increased by the afternoon (SN 67%, PPV 69%). Similarly, for same‐day discharge predictions, SN and PPV were highest at midday (88% and 79%, respectively). We found that although physicians have difficulty predicting next‐day discharges in the morning prior to the day of expected discharge, their ability to correctly predict discharges continually improved as the time to actual discharge decreased. Journal of Hospital Medicine 2015;10:808–810. © 2015 Society of Hospital Medicine
Observational investigation of relationships between moisture surges and mesoscale‐ to large‐scale convection during the North American monsoon
Authors: Mejia John F. , Douglas Michael W. , Lamb Peter J.
Published: October 2015

This article consists of a comprehensive climatological study of moisture surges (MSs) in the North American monsoon (NAM) core region using a multiyear (1990–2006) set of surges, surface and upper air data, satellite‐estimated mesoscale convective systems (MCSs), and North American Regional Reanalysis (NARR) products. Composites of surges are created with respect to MCSs occurrence in the NAM core region. MSs are further stratified based on co‐occurrence with tropical easterly waves and tropical storms/tropical cyclones. These results provide new insights into the nature of the Gulf of California (GoC) moisture flux variability and describe the influence of these multi‐scale processes on the occurrence and intensity of surges and the GoC diurnal circulations – especially the Gulf of California low‐level jet (GCLLJ). Results show that over the GoC Coastal Plain, MCSs modulate the diurnal cycle of the GoC low‐level circulation during ‘major surge’, ‘minor surge’, and ‘non‐surge’ environments. We found that MCS activity enhances the offshore flow along the eastern GoC coast, which then enhances the GCLLJ. On the other hand, immediately before major surges onset, the occurrence of MCSs over the southern GoC produces more intense surges. It is also shown that this relationship holds regardless of the intensity and type of tropical synoptic‐scale disturbance forcing the surge.
Sortable silt cycles in Svalbard slope sediments 74–0 ka
Authors: Jessen Simon P. , Rasmussen Tine L.
Published: October 2015

The grain size of sortable silt (SS, 10–63 μm) was studied in sediment core JM04‐025PC from a sediment drift on the lower part of the western Svalbard slope. The study aims to reconstruct the bottom current activity and intermediate water circulation in the Greenland Sea. The SS record covers the last 74 ka and shows consistent millennial‐scale oscillations in grain size. The youngest part of the record (<25 ka) is well correlated with the few available previously published reconstructions of grain size from the North Atlantic Ocean and the Nordic seas. Fining of SS occurs during four well‐known regional cold climatic intervals, the 8.2‐ka cold spell, the Younger Dryas and North Atlantic Heinrich Events H1 and H2, as well as during a local meltwater event at 14.4–14.7 ka, possibly coinciding with the Older Dryas. Also before 25 ka, grain size oscillated in pace with the Northern Hemisphere climate with finer grain sizes during cold periods and coarser grain sizes during warm periods. The fining of SS indicates reduced bottom current strength and reduced water exchange between the Greenland Sea and the Arctic Ocean during regional climate cooling events, and probably also reduced deep ocean convection in the Greenland Sea gyre.
The impact of transoral robotic surgery on the overall treatment of oropharyngeal cancer patients
Authors: Smith Richard V. , Schiff Bradley A. , Garg Madhur , Haigentz Missak
Published: October 2015

Objectives/Hypothesis

To assess adjuvant therapy in patients undergoing surgical management of oropharyngeal squamous cell carcinoma (OPSCCA) with transoral robotic surgery (TORS) and neck dissection.

Study Design

A prospective, nonrandomized, consecutive patient series from two separate protocols in a tertiary academic medical center.

Methods

Patients undergoing treatment for OPSCCA were selected from a prospective protocol evaluating functional and oncologic outcomes following TORS with a comparator group of OPSCCA patients receiving definitive chemoradiotherapy (CRT) participating in a separate prospective protocol.

Results

Forty‐two patients represented the TORS group and 38 the CRT group. Twenty (48%) of the TORS patients received surgery only, whereas nine (21%) underwent adjuvant radiotherapy and 13 (31%) adjuvant CRT. Adjuvant therapy patients had a higher overall T (P =.0007) and N (P < .0001) stage than the TORS‐only group. Surgery resulted in stage changes in 18 (43%) patients, leading to alteration in therapy for nine (21%) patients. The 3‐year overall survival (OS), disease‐specific survival (DSS), and locoregional control was 74% versus 90% (P = .30), 94% versus 94% (P = .91), and 72% versus 91% (P = .19) for the TORS‐alone versus TORS plus adjuvant therapy groups, respectively. Comparison with the CRT group revealed a survival benefit in the TORS group approaching significance, with a 3‐year OS of 83% versus 57% (P = .06) and DSS of 94% versus 85% (P = .08), respectively.

Conclusions

Primary surgical management of OPSCCA with TORS and neck dissection provides accurate staging information, which can lead to the appropriate selection of subsequent therapy. This approach does not compromise survival and warrants additional investigation.

Level of Evidence

3b. Laryngoscope, 125:S1–S15, 2015
Characterization of Mycobacterium smegmatis sigF mutant and its regulon: overexpression of SigF antagonist (MSMEG_1803) in M. smegmatis mimics sigF mutant phenotype, loss of pigmentation, and sensitivity to oxidative stress
Authors: Singh Anirudh K. , Dutta Debashis , Singh Vandana , Srivastava Vishal , Biswas Rajesh K. , Singh Bhupendra N.
Published: October 2015

In Mycobacterium smegmatis, sigF is widely expressed during different growth stages and plays role in adaptation to stationary phase and oxidative stress. Using a sigF deletion mutant of M. smegmatis mc2155, we demonstrate that SigF is not essential for growth of bacterium. Deletion of sigF results in loss of carotenoid pigmentation which rendered increased susceptibility to H2O2 induced oxidative stress in M. smegmatis. SigF modulates the cell surface architecture and lipid biosynthesis extending the repertoire of SigF function in this species. M. smegmatis SigF regulon included variety of genes expressed during exponential and stationary phases of growth and those responsible for oxidative stress, lipid biosynthesis, energy, and central intermediary metabolism. Furthermore, we report the identification of a SigF antagonist, an anti‐sigma factor (RsbW), which upon overexpression in M. smegmatis wild type strain produced a phenotype similar to M. smegmatis mc2155 ΔsigF strain. The SigF‐anti‐SigF interaction is duly validated using bacterial two‐hybrid and pull down assays. In addition, anti‐sigma factor antagonists, RsfA and RsfB were identified and their interactions with anti‐sigma factor were experimentally validated. Identification of these proteins will help decode regulatory circuit of this alternate sigma factor.
A distinctive oral phenotype points to FAM20A mutations not identified by Sanger sequencing
Authors: Poulter James A. , Smith Claire E. L. , Murrillo Gina , Silva Sandra , Feather Sally , Howell Marianella , Crinnion Laura , Bonthron David T. , Carr Ian M. , Watson Christopher M. , Inglehearn Chris F. , Mighell Alan J.
Published: October 2015

Biallelic FAM20A mutations cause two conditions where Amelogenesis Imperfecta (AI) is the presenting feature: Amelogenesis Imperfecta and Gingival Fibromatosis Syndrome; and Enamel Renal Syndrome. A distinctive oral phenotype is shared in both conditions. On Sanger sequencing of FAM20A in cases with that phenotype, we identified two probands with single, likely pathogenic heterozygous mutations. Given the recessive inheritance pattern seen in all previous FAM20A mutation‐positive families and the potential for renal disease, further screening was carried out to look for a second pathogenic allele. Reverse transcriptase‐PCR on cDNA was used to determine transcript levels. CNVseq was used to screen for genomic insertions and deletions. In one family, FAM20A cDNA screening revealed only a single mutated FAM20A allele with the wild‐type allele not transcribed. In the second family, CNV detection by whole genome sequencing (CNVseq) revealed a heterozygous 54.7 kb duplication encompassing exons 1 to 4 of FAM20A. This study confirms the link between biallelic FAM20A mutations and the characteristic oral phenotype. It highlights for the first time examples of FAM20A mutations missed by the most commonly used mutation screening techniques. This information informed renal assessment and ongoing clinical care.
Patient perceptions of nurse mentors facilitating the Aussie Heart Guide: A home‐based cardiac rehabilitation programme for rural patients.
Authors: Frohmader Terence John , Lin Frances , Chaboyer Wendy
Published: October 2015

Aim

To explore and describe long‐term thoughts and perceptions of the Aussie Heart Guide Programme including the role of the mentor, held by patients recovering from myocardial infarction.

Design

A qualitative design.

Methods

Thirteen patients recovering from myocardial infarction who were unable to attend a hospital‐based or affiliated outpatient cardiac rehabilitation programme were interviewed by telephone at the completion of the programme and asked to describe the relationship with their assigned nurse mentor and their perception of the audiovisual used in the programme.

Results

Three themes emerged; assisting me to cope, supporting me and my family and tailoring the programme to my needs. Patients were satisfied with the programme and appreciative of the supportive and caring relationships provided by mentors during their hospitalization through to their discharge from the programme.
Treatment of Glycine and Proline in Late Ar‐O2 Afterglow
Authors: Nominé Anna V. , Mafra Marcio , Frache Gilles , Belmonte Thierry
Published: October 2015

Glycine and proline have been treated in Ar‐O2 afterglows at low temperature to study their modification in highly reactive non‐equilibrium media. These two amino‐acids can be efficiently etched in suited conditions. In the case of glycine, O(3P) is the main reactive species responsible for the etching mechanism. It reacts preferentially with the CH2 group instead of the amine group NH2. Further oxidation processes are observed but they are not rate‐limiting. Etching of proline is a multi‐step process, probably initiated by O(3P) and then followed by reactions which control the etch‐rate, the opening of the non‐aromatic ring of proline being a probable route.
Thin Film Deposition on Open‐Cell Foams by Atmospheric Pressure Dielectric Barrier Discharges
Authors: Fanelli Fiorenza , Fracassi Francesco
Published: October 2015

Thin films are deposited on open‐cell polyurethane (PU) foams using an atmospheric pressure dielectric barrier discharge (DBD) fed with helium and hexafluoropropene (C3F6). During deposition processes, a foam substrate is sandwiched between the dielectric‐covered electrodes of a parallel plate DBD reactor, so that the discharge can ignite also inside its three‐dimensional (3D) interconnected porous structure. This affords the deposition of a fluorocarbon coating on both the exterior and interior of the foam. Scanning electron microscopy (SEM) observations allow estimating the thickness of the coating deposited on the foam struts, while X‐ray photoelectron spectroscopy (XPS) analyses show moderate changes in surface chemical composition moving from the outer to the inner surfaces of the plasma‐treated foams under all explored experimental conditions.
Role of aberrant IgG glycosylation in the pathogenesis of inflammatory bowel disease
Authors: Miyoshi Eiji , Shinzaki Shinichiro , Fujii Hironobu , Iijima Hideki , Kamada Yoshihiro , Takehara Tetsuo
Published: October 2015

The intestine is one of the most important organs associated with the immune system. It is thought that disruption of intestinal immunity causes inflammatory bowel disease (IBD). Recent advances in immune glycobiology have provided novel insights into many human diseases. For example, studies of glycosylation remodeling in mice have underscored the importance of oligosaccharides in the pathogenesis of IBD. Furthermore, aberrant glycosylation of IgG is a good serum marker of IBD activity. In this review, we examine current understanding of the role of aberrant glycosylation in the pathogenesis of IBD in terms of our original data and recent reports.
Structure of the N‐terminal domain of the metalloprotease PrtV from Vibrio cholerae
Authors: Edwin Aaron , Persson Cecilia , Mayzel Maxim , Wai Sun Nyunt , Öhman Anders , Karlsson B. Göran , Sauer‐Eriksson A. Elisabeth
Published: October 2015

The metalloprotease PrtV from Vibrio cholerae serves an important function for the ability of bacteria to invade the mammalian host cell. The protein belongs to the family of M6 proteases, with a characteristic zinc ion in the catalytic active site. PrtV constitutes a 918 amino acids (102 kDa) multidomain pre‐pro‐protein that undergoes several N‐ and C‐terminal modifications to form a catalytically active protease. We report here the NMR structure of the PrtV N‐terminal domain (residues 23–103) that contains two short α‐helices in a coiled coil motif. The helices are held together by a cluster of hydrophobic residues. Approximately 30 residues at the C‐terminal end, which were predicted to form a third helical structure, are disordered. These residues are highly conserved within the genus Vibrio, which suggests that they might be functionally important.
Adaptive truncated weighting for improving marginal structural model estimation of treatment effects informally censored by subsequent therapy
Authors: Bai Xiaofei , Liu Jingyi , Li Li , Faries Douglas
Published: October 2015

Randomized clinical trials are designed to estimate the direct effect of a treatment by randomly assigning patients to receive either treatment or control. However, in some trials, patients who discontinued their initial randomized treatment are allowed to switch to another treatment. Therefore, the direct treatment effect of interest may be confounded by subsequent treatment. Moreover, the decision on whether to initiate a second‐line treatment is typically made based on time‐dependent factors that may be affected by prior treatment history. Due to these time‐dependent confounders, traditional time‐dependent Cox models may produce biased estimators of the direct treatment effect. Marginal structural models (MSMs) have been applied to estimate causal treatment effects even in the presence of time‐dependent confounders. However, the occurrence of extremely large weights can inflate the variance of the MSM estimators. In this article, we proposed a new method for estimating weights in MSMs by adaptively truncating the longitudinal inverse probabilities. This method provides balance in the bias variance trade‐off when large weights are inevitable, without the ad hoc removal of selected observations. We conducted simulation studies to explore the performance of different methods by comparing bias, standard deviation, confidence interval coverage rates, and mean square error under various scenarios. We also applied these methods to a randomized, open‐label, phase III study of patients with nonsquamous non‐small cell lung cancer. Copyright © 2015 John Wiley & Sons, Ltd.
Adaptive finite‐time control for nonlinear teleoperation systems with asymmetric time‐varying delays
Authors: Zhai Di‐Hua , Xia Yuanqing
Published: October 2015

This paper addresses the adaptive finite‐time control problem of nonlinear teleoperation system in the presence of asymmetric time‐varying delays. To achieve the finite‐time position tracking, a novel adaptive finite‐time coordination algorithm based on subsystem decomposition is developed. By introducing a switching‐technique‐based error filtering into our design framework, the complete closed‐loop master (slave) teleoperation system is modeled as a special class of switched system, which is composed of two subsystems. To analyze such system, a finite‐time state‐independent input‐to‐output stability criterion is first developed for some normal switched nonlinear delayed systems. Then based on the classical Lyapunov–Krasovskii method, the stability of complete closed‐loop systems is obtained. It is shown that the proposed scheme can make the position errors converge into a deterministic domain in finite time when the robots continuously contact with human operator and/or the environment in the presence of asymmetric time‐varying delays. Finally, the simulation results are given to demonstrate the effectiveness. Copyright © 2015 John Wiley & Sons, Ltd.
Energy compensation‐based approach for solving the HJI equation in the nonlinear H∞ synthesis
Authors: Han C. , Guo J. , Pechev A.
Published: October 2015

The H∞ framework provides an efficient and systemic method for the design of controllers for both linear and nonlinear systems. In the nonlinear controller synthesis, however, the limitation of this method is usually associated with the existence of a solution to the Hamilton–Jacobi–Isaac (HJI) equation. In this paper, an innovative energy compensation‐based approach to the solution of the HJI equations is presented and compared with the existing methods relying on Taylor series expansion. This new approach provides an efficient methodology that ensures the existence of a solution to the HJI equation. Numerical application to spacecraft attitude control is presented to validate the developments. Copyright © 2015 John Wiley & Sons, Ltd.
Zooming in: A practical manual for identifying geographic clusters
Authors: Alcácer Juan , Zhao Minyuan
Published: October 2015

Research summary: This paper advances strategic management research by taking a close look at the reasons, procedures, and results of cluster identification methods, focusing on a density‐based algorithm that organically define clusters from actual locations of economic activities. Despite being a popular research topic and analytical tool, geographic clusters are often studied with little consideration given to the underlying economic activities, the unique cluster boundaries, or the appropriate benchmark of economic concentration. Our goal is to increase awareness of the complexities behind cluster identification, and to provide concrete insights and methodologies applicable to various empirical settings. The method we propose is especially useful when researchers work in global settings, where data available at different geographic units complicates comparisons across countries.

Managerial summary: Geographic proximity has been recognized as a fundamental factor driving firm performance, especially in knowledge‐intensive industries. However, despite increasing interest in the study of geographic clusters—locations with a high concentration of economic activity—we as researchers have not given sufficient consideration to the underlying economic activity, the unique cluster boundaries, or even the definition of economic concentration. In this paper, we carefully examined the existing methodologies for cluster identification and proposed a method that defines clusters based on the actual location of economic activity. This new method is applicable to various empirical settings beyond geographic clusters. In addition, because clusters are defined by actual economic activity rather than administrative boundaries, it allows for meaningful comparison across countries. Copyright © 2015 John Wiley & Sons, Ltd.
Scientific apophenia in strategic management research: Significance tests & mistaken inference
Authors: Goldfarb Brent , King Andrew A.
Published: October 2015

Research summary: This article uses distributional matching and posterior predictive checks to estimate the extent of false and inflated findings in empirical research on strategic management. Based on a sample of 300 papers in top outlets for research on strategic management, we estimate that if each study were repeated, 24–40 percent of significant coefficients would become insignificant at the five percent level. Our best guess is that for about half of these, the true coefficient is very close to 0. The remaining coefficients are likely directionally correct but inflated in magnitude. We offer several practical individual and field level suggestions for reducing scientific apophenia, that is, our tendency to find and publish evidence of order where none exists.

Managerial summary: This article analyzes the degree to which statistics in research on strategic management provide meaningful evidence for decision-making. Based on a sample of 300 papers, we estimate that 24%–40% of reported results would probably not be confirmed if the study were repeated. Our best guess is that about half of the reported results are wrong (B∼ = 0) and the other half of results too weak to find repeatedly. We conclude that scientific apophenia—the tendency to find evidence of order where none exists—is a serious problem in the literature on strategic management. We recommend replication of empirical studies to insure that they provide evidence for guiding managers. We also provide guidance for avoiding scientific apophenia in empirical research. Copyright © 2015 John Wiley & Sons, Ltd.
A stochastic power curve for wind turbines with reduced variability using conditional copula
Authors: Bai Guanghan , Fleck Brian , Zuo Ming J.
Published: October 2015

It has been observed that a large variability exists between wind speed and wind power in real metrological conditions. To reduce this substantial variability, this study developed a stochastic wind turbine power curve by incorporating various exogenous factors. Four measurements, namely, wind azimuth, wind elevation, air density and solar radiation are chosen as exogenous influence factors. A recursive formula based on conditional copulas is used to capture the complex dependency structure between wind speed and wind power with reduced variability. A procedure of selecting a proper form for each factor and its corresponding copula models is given. Through a case study on the small wind turbine located in southeast of Edmonton, Alberta, Canada, we demonstrate that the variability can be reduced significantly by incorporating these influence factors. Wind turbine operators can apply the method reported in this study to construct a stochastic power curve for local wind farms and use it to achieve more accurate power forecasting and health condition monitoring of the turbine. Copyright © 2015 John Wiley & Sons, Ltd.
Revealing the impact of local access-site complications and upper extremity dysfunction post transradial percutaneous coronary procedures
Authors: Zwaan E.M. , Koopman A.G.M.M. , Holtzer C.A.J. , Zijlstra F. , Ritt M.J.P.F. , Amoroso G. , Moerman E. , Kofflard M.J.M. , IJsselmuiden A.A.J.
Published: October 2015

Objectives

Little is known about local access-site complications and upper extremity dysfunction after transradial percutaneous coronary procedures (TR-PCP). This systematic review study aimed to summarise the current knowledge on the incidences of access-site complications and upper extremity dysfunction after TR-PCP.

Methods

Two independent, trained investigators searched MEDLINE, EMBASE and CENTRAL for eligible studies published before 1 January 2015. Also, they hand-searched the conference proceedings of the annual scientific sessions of the American College of Cardiology, the American Heart Association, European Society of Cardiology, and the Trans-catheter Cardiovascular Therapeutics. Inclusion criteria were cohort studies and clinical trials discussing the incidence of access-site complications and upper extremity function after transradial percutaneous coronary intervention (TR-PCI) and/or transradial coronary angiography (TR-CAG) as endpoints.

Results

176 articles described access-site complications. The incidence is up to 9.6 %. Fourteen articles described upper extremity dysfunction, with an incidence of up to 1.7 %. Upper extremity dysfunction was rarely investigated, hardly ever as primary endpoint, and if investigated not thoroughly enough.

Conclusion

Upper extremity dysfunction in TR-PCP has never been properly investigated and is therefore underestimated. Further studies are needed to investigate the magnitude, prevention and best treatment of upper extremity dysfunction. Optimising TR-PCP might be achieved by using slender techniques, detection of upper extremity dysfunction and early referral to a hand rehabilitation centre.
Do Targeted Stipend Programs Reduce Gender and Socioeconomic Inequalities in Schooling Attainment? Insights From Rural Bangladesh
Authors: Behrman Julia Andrea
Published: October 2015

Social investment in schooling in low-income countries has increased greatly in the 1990s and 2000s because of the robust associations among schooling and demographic, economic, and health outcomes. This analysis investigates whether targeted school-attendance stipend programs succeeded in reducing gender and socioeconomic inequalities in school attainment among a sample of the rural poor in Bangladesh. Multivariate analyses find that targeted stipend programs helped to reduce the gender attainment gap. Females had an increased probability of participating in stipend programs, and returns to stipend participation were significantly higher for females. However, stipend programs failed to reduce the relative achievement gap between children of different socioeconomic backgrounds: low socioeconomic status (SES) was associated with a decreased probability of stipend participation, and stipend-related schooling gains for lower-SES females were matched by comparable gains for higher–SES females. Meanwhile, there was no significant association between stipend participation and schooling attainment for males.
The prevalence of community-associated methicillin-resistant Staphylococcus aureus among outpatient children in a tertiary hospital
Authors: Alaklobi F. , Aljobair F. , Alrashod A. , Alhababi R. , Alshamrani M. , Alamin W. , Lytvyn Lyubov , Alrouki F. , Mertz D.
Published: October 2015

Background and objectives:

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) infections among previously healthy persons in community settings, without exposure to health care facilities, has been noted recently. Colonization rates of community-associated MRSA (CA-MRSA) have been reported to range from 0 to 9.2 percent. The nose and open skin areas are considered the most important sites for colonization. The aim of our study was to assess the prevalence and to describe the antibiotic susceptibility pattern of CA-MRSA among outpatient children.

Patients and methods:

We prospectively screened every third consecutive child presenting to our pediatric emergency department of King Saud Medical City, a 275 bed tertiary care teach-ing hospital in Riyadh, Saudi Arabia, from March through July 2015.

Results:

We analyzed a total of 830 screening results (n = 478 males, 57.6%). Most of the screened patients were from Riyadh (n = 824, 99.3%). A total of 164 (19.8%) were found to be colonized with S. aureus, and of these 38 (4.6%) with MRSA. Thus, the MRSA rate amongst all S. aureus carriers was 23.2%. All MRSA were susceptible to vancomycin, (94.7%) were suscep-tible to linezolid, (65.8%) to clindamycin, and (89.5%) to trimethoprim/sulfamethoxazole.

Conclusion:

The rate of MRSA carriage among children in Riyadh province was within the range reported internationally. As the MRSA rate among S. aureus infected children was 23.2%, empirical MRSA coverage should be considered in children with suspected S. aureus infections. Copyright © 2015, King Faisal Specialist Hospital & Research Centre (General Organization), Saudi Arabia. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
CT enterography in the evaluation of Crohn's disease
Authors: dos Santos Carlos Henrique Marques , da Silva Menezes Jovino Nogueira , Nunes Thiago Franchi , de Assis Martins Letícia
Published: October 2015

Proposition Crohn's disease (CD) is a chronic inflammatory process that affects various parts of the gastrointestinal tract, from the mouth to the anus with unknown etiology and variable clinical presentation. CD diagnosis is based on clinical and complementary tests. Among the complementary tests, enterography with CT enterography has shown good results in the evaluation of this disease.

Methods The patients evaluated were submitted to a questionnaire on the clinical manifestations of the disease and an CT enterography was obtained. The studies were reviewed by an experienced radiologist looking for radiological signs of CD.

Results The mean age was 40 years, with a predominance of women. The main clinical manifestations are diarrhea in 24 (70%), hematochezia in 19 (55%), abdominal pain in 29 (85%) and weight loss in 22 (64%) patients. The main findings on CT enterography were an intestinal wall enhancement signal in 23 patients (67%), vascular engorgement (vasa recta) in 20 (58%), parenteral fat densification in 14 (41%), intestinal wall thickening in 22 (64%), and lymph node enlargement in 17 (50%) of patients.

Conclusion This study showed that CT enterography presents a good assessment of intestinal involvement by CD.
The dilemmas of organisational capacity
Authors: Anne Tiernan
Published: October 2015

For 40 years public sector reformers have lamented the lack of ‘leadership skills’ in career bureaucracies. They have brought successive waves of change aimed at making the public service more efficient, agile and responsive. An extensive scholarly literature acknowledges the problematic nature of ‘leadership’ in a public sector context — the difficulties inherent to a model premised on responsibility and accountability being shared by elected and career officials. But these insights seem lost on politicians, whose efforts to exert greater control over career officials have brought a range of unintended consequences, mainly because management reforms do not recognise the primacy of politics, nor the stewardship obligations of public sector leaders. In this article, I argue that ambiguities in the roles, responsibilities and relationships between ministers and senior officials must be addressed as a prerequisite for reform. A reimagined partnership between elected and unelected officials is essential to improve policy capacity.
Organizational political capacity as learning
Authors: Dunlop Claire A
Published: October 2015

In this article, we examine how agencies build organizational political capacities (OPC) for reputation management, where capacity building is treated as a challenge underpinned by the learning relationships that exist between key governance actors. This challenge requires the development of four types of OPC: absorptive capacity (ACAP); administrative capacity (ADCAP); analytical capacity (ANCAP) and communicative capacity (COMCAP). Analytically, we link each of these capacities to one particular type of policy learning — reflexive learning — which characterises politicised situations where an agencies reputation is under threat and citizens are the main governance partners. Empirically, we demonstrate how agencies learn to develop these OPCs with governance partners using the case of the UK Health and Safety Executive (HSE) which increasingly aims to engage citizens in a dialogue to combat the negative images attached to health and safety regulation. We conclude asking what a learning approach tells us about how agencies can develop OPC.