bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting Corporate Failure Using a Neural Network Approach
Authors: Boritz J.E. , Kennedy D.B. , Albuquerque Augusto de Miranda e
Published: March 2014

Abstract

This paper investigates the performance of Artificial Neural Networks for the classification and subsequent prediction of business entities into failed and non‐failed classes. Two techniques, back‐propagation and Optimal Estimation Theory (OET), are used to train the neural networks to predict bankruptcy filings. The data are drawn from Compustat data tapes representing a cross‐section of industries. The results obtained with the neural networks are compared with other well‐known bankruptcy prediction techniques such as discriminant analysis, probit and logit, as well as against benchmarks provided by directly applying the bankruptcy prediction models developed by Altman (1968) and Ohlson (1980) to our data set. We control the degree of ‘disproportionate sampling’ by creating ‘training’ and ‘testing’ populations with proportions of bankrupt firms ranging from 1% to 50%. For each population, we apply each technique 50 times to determine stable accuracy rates in terms of Type I, Type II and Total Error. We show that the performance of various classification techniques, in terms of their classification errors, depends on the proportions of bankrupt firms in the training and testing data sets, the variables used in the models, and assumptions about the relative costs of Type I and Type II errors. The neural network solutions do not achieve the ‘magical’ results that literature in this field often promises, although there are notable 'pockets' of superior performance by the neural networks, depending on particular combinations of proportions of bankrupt firms in training and testing data sets and assumptions about the relative costs of Type I and Type II errors. However, since we tested only one architecture for the neural network, it will be necessary to investigate potential improvements in neural network performance through systematic changes in neural network architecture.
The Definition and Diffusion of Expert Systems: An Empirical Survey of Belgian External Audit Firms
Authors: Acker Carine Van den , Vanthienen Jan
Published: March 2014

Abstract

This paper reports empirical results on the definition and diffusion of expert systems (ESs). The findings are based on a questionnaire that was sent to Belgian external audit firms in June 1993. Audit firms were chosen as the questionnaire's target group because another part of the survey was aimed at gathering information concerning the audit of ESs. The definition section deals with the importance of several ES characteristics as seen by the sample of practitioners. Results are compared with opinions from theoretical literature and reveal significant differences. The section on diffusion of ESs is intended to provide an indication of the extent of development and usage of ESs in todays business life. On the basis of the sample of audit firms that reported on their auditees' situations, diffusion rates are rather low. Each of these sections is introduced by a short literature review. As both sections are largely based on the results of a survey, relevant details are included in the first section.
Supporting the Process of Customer Consulting in the Field of Financial Services
Authors: Rossbach Peter
Published: March 2014

Abstract

An increase in competition and a change in customer needs has caused financial service companies to revise their operations and establish a coordinated product and market strategy. Customer consulting is a substantial part of this type of strategy. Due to the increasing number, complexity and diversity of financial products, the client adviser is confronted by a continuously expanding range of required expert knowledge, which in most cases extends beyond his capabilities. To deal with these problems, supporting the consulting process with information technology seems to be appropriate. At a glance, the usage of currently employed advisory support systems indicates that the system support does not fulfil the financial company's needs. For this reason we developed ALLFIWIB to actively support every phase of the client advisory process as well as to improve upon the quality of financial product supply. ALLFIWIB is designed as a blackboard‐based distributed problem‐solving system. Initial usage of ALLFIWIB has indicated that the system is capable of providing intelligent solutions to financial problems and thus considerably lessens the burden on the client adviser.
Ernest Everett Just: Egg and embryo as excitable systems
Authors: Byrnes W. Malcolm , Newman Stuart A.
Published: March 2014

Ernest Everett Just (1883–1941) was an African American embryologist of international standing whose research interests lay in the area of fertilization and early development in marine invertebrates. Perhaps best known for his discovery of the dynamical and structural blocks to polyspermy that sweep over the egg upon fertilization, E. E. Just also was the first to associate cell surface changes with stages of embryonic development. He was deeply familiar with the natural history of the animals whose eggs he studied, and his knowledge of natural settings led him to emphasize the importance of using laboratory conditions that closely match those in nature. Based on more than 30 years of work, he came to believe that it was the cell surface that played the most critical role in development, heredity, and evolution. He promoted a holistic view of cells and organisms in opposition to the gene‐centric view that was becoming more prevalent with the rise of genetics, but rejected the vitalism espoused by some biologists of his era, calling instead for “a physics and chemistry in a new dimension …superimposed upon the now known physics and chemistry” to account for biological phenomena. Just's incisive critique of genetic reductionism finds echoes in contemporary multiscale, systems approaches in biology. His speculations on the relationship between developmental and evolutionary mechanisms resonate with today's evolutionary developmental biology. After a brief biographical sketch, this paper outlines and discusses some of Just's scientific contributions, and shows how his ideas remain relevant today. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 191–201, 2014. © 2014 Wiley Periodicals, Inc.
Genomics, evolution and development of amphioxus and tunicates: The Goldilocks principle
Authors: Holland Linda Z.
Published: March 2014

Morphological comparisons among extant animals have long been used to infer their long‐extinct ancestors for which the fossil record is poor or non‐existent. For evolution of the vertebrates, the comparison has typically involved amphioxus and vertebrates. Both groups are evolving relatively slowly, and their genomes share a high level of synteny. Both vertebrates and amphioxus have regulative development in which cell fates become fixed only gradually during embryogenesis. Thus, their development fits a modified hourglass model in which constraints are greatest at the phylotypic stage (i.e., the late neurula/early larva), but are somewhat greater on earlier development than on later development. In contrast, the third group of chordates, the tunicates, which are sister group to vertebrates, are evolving rapidly. Constraints on evolution of tunicate genomes are relaxed, and they have discarded key developmental genes and organized much of their coding sequences into operons, which are transcribed as a single mRNA that undergoes trans‐splicing. This contrasts with vertebrates and amphioxus, whose genomes are not organized into operons. Concomitantly, tunicates have switched to determinant development with very early fixation of cell fates. Thus, tunicate development more closely fits a progressive divergence model (shaped more like a wine glass than an hourglass) in which the constraints on the zygote and very early development are greatest. This model can help explain why tunicate body plans are so very diverse. The relaxed constraints on development after early cleavage stages are correlated with relaxed constraints on genome evolution. The question remains: which came first? J. Exp. Zool. (Mol. Dev. Evol.) 324B: 342–352, 2015. © 2014 Wiley Periodicals, Inc.
A Convenient and Facile Synthesis of Isoxazolyl‐chromeno[4,3,2‐de]pyrimido[4,5‐h][1,6]napthyridinones
Authors: Rajanarendar Eligeti , Ramakrishna Saini , Kishore Baireddy
Published: March 2014

The ceric ammonium nitrate‐catalyzed synthesis of (E)‐5‐amino‐N‐(3‐methyl‐5‐styrylisoxazol‐4‐yl)‐2‐arylchromeno[4,3,2‐de][1,6]napthyridin‐4‐carboxamides 5 was simply achieved upon the one‐pot four‐component reaction of isoxazolyl cyanoacetamide 1 with malononitrile 2, 2‐hydroxy acetophenone 3, and aromatic aldehydes 4 in ethanol. Compounds 5 on heating with acetic anhydride underwent tandem N‐acetylation and cyclocondensation involving intramolecular cyclization to afford the title compounds (E)‐11‐methyl‐12‐(3‐methyl‐5‐styrylisoxazol‐4‐yl)‐2‐arylchromeno[4,3,2‐de][1,6]napthyridin‐13(12H)‐ones 6 in good yields. The chemical structures have been confirmed by analytical and spectral analyses.
An Exploration of Challenges Facing Muslim Americans’ Advancement to Leadership in the Legal Field
Authors: Kadi Ali S.
Published: March 2014

The purpose of this qualitative exploratory case study was to explore and identify obstacles that Muslim Americans in the United States working within the legal field experienced in advancing to leadership positions and to explore the influence of mentoring. The two cases included 10 Muslim Americans in leadership positions and 10 in nonleadership positions in the legal field in northern Virginia and Washington, D.C. Data were collected through structured and semi‐structured interviews, observations, and field notes. Themes and patterns were analyzed within and across data sources and cases for convergence, divergence, and triangulation. The results indicated that discrimination and the lack of opportunities, training, mentoring programs, support and guidance, and influential leaders hindered participants’ advancement to leadership positions. Results revealed common major barriers to the lack of opportunity, social support, and understanding. The support and guidance of a mentor and degree attainment contributed to advancement. Leaders and nonleaders experienced similar obstacles to and supports for advancement. Lack of leadership experience was a barrier for nonleaders. The findings confirmed current literature on negative attitudes Muslim Americans face working and living in the United States following the September 11, 2001, terrorist attacks.
Palatal myoclonus: Algorithm for management with botulinum toxin based on clinical disease characteristics
Authors: Sinclair Catherine F. , Gurey Lowell E. , Blitzer Andrew
Published: March 2014

Objectives/Hypothesis

To review the clinical characteristics and management of patients with palatal myoclonus and devise an algorithm for treatment with botulinum toxin based on presenting symptoms, clinical examination findings, and involved muscle groups.

Study Design

Retrospective chart review at two clinical research centers.

Methods

Between 1985 and 2011, 15 patients with a diagnosis of essential palatal myoclonus were assessed. Data were collected on patient demographics, disease characteristics, and treatment outcomes.

Results

Patients were more commonly female (60.0% vs. 40.0%) with average age at onset of 35.6 years. In 40.0% of patients, the myoclonus began after a viral upper respiratory tract infection. Two‐thirds of patients had been previously treated unsuccessfully with oral medications. Predominant presenting symptoms included clicking tinnitus (46.7%), nonaudible awareness of palatal movements ± rhinolalia (20.0%), or both (33.3%). Clinical examination revealed co‐incident involvement of pharyngeal musculature in 53.3%. Palatal site for initial botulinum toxin injection depended on the predominant presenting symptom: for tinnitus, 2.5 U were injected transorally into the tensor veli palatini muscle at the level of the pterygoid hamulus/lateral soft palate; for palatal movements, the injection was placed medially on either side of the uvula. Dose and location of subsequent injections were tailored depending on response to the toxin and location of subsequent observed maximal muscular contractions.

Conclusions

Palatal myoclonus can present with tinnitus or patient‐perceived palatal movements. Management with botulinum toxin can be tailored to address the muscles contributing to the predominant presenting symptoms.

Level of Evidence

4 Laryngoscope, 124:1164–1169, 2014
Comparison of the risk of postoperative infection between transurethral vaporesection and transurethral resection of the prostate
Authors: May Alexandre , Broggi Etienne , Lorphelin Henri , Tabchouri Nicolas , Giretti Giovani , Pereira Helder , Bruyere Franck
Published: March 2014

Background and Objective

We observed in our department at 3 months two episodes of bacteremia postoperatively to photoselective vaporization of the prostate (PVP). We decided to compare the frequency of postoperative urinary tract infections (POUTIs) in patients with preoperative bacterial colonization of urine between PVP and transurethral resection of the prostate (TURP).

Materials and Methods

From January 2010 to December 2011, we studied patients who underwent PVP or TURP for benign prostatic obstruction in our department. Preoperative urine culture (UC) was carried out for all patients and we included those with preoperative bacterial colonization of the urinary tract. Patients were treated preoperatively with an appropriate antibiotic treatment and/or inductive prophylactic antibiotics. Patients were diagnosed with POUTI if they had clinical signs of infections (e.g., fever) and a positive UC during the month after surgery.

Results

Patients were treated by PVP in 49 cases and TURP in 62 cases. A preoperative indwelling urinary catheter was inserted in 80% of the patients. During the postoperative period, eight episodes of fever were identified in the PVP group (16%), five (8%) in the TURP group (P = 0.18). We then studied the subgroup of patients with multiple bacteria strains present in the preoperative UC and identified significant differences. The risk of POUTI was significantly higher in patients treated by PVP than in those treated by TURP (P = 0.018).

Conclusions

We found significant differences between subgroups of patients with positive preoperative cultures (containing various bacterial strains). The risk of POUTI was significantly higher in patients treated by PVP. Lasers Surg. Med. 46:405–411, 2014. © 2014 Wiley Periodicals, Inc.
Hepatic venous congestion in living donor grafts in liver transplantation: Is there an effect on hepatocellular carcinoma recurrence?
Authors: Suh Suk-Won , Lee Jeong-Moo , You Tae , Choi Young Rok , Yi Nam-Joon , Lee Kwang-Woong , Suh Kyung-Suk
Published: March 2014

A certain degree of graft congestion in living donor liver transplantation (LDLT) using a right liver graft may be inevitable because of the mismatch between the inflow and outflow structures of the liver. The subsequent inflammatory reaction and rapid regeneration of the graft have been suggested as causes of tumor recurrence. Therefore, we investigated the influence of graft congestion on hepatocellular carcinoma (HCC) recurrence after LDLT. Two hundred eighty-nine LDLT patients for HCC within the University of California San Francisco criteria between November 1999 and February 2012 were investigated. Patients were assigned to groups on the basis of the degree of congestion (≤10% for group A and >10% for group B), which was determined by 3-dimensional reconstruction of posttransplant multidetector helical computed tomography within 2 weeks. Perioperative characteristics, regeneration rates after 6 months, and recurrence rates were compared between the groups, and a multivariate analysis of the influence of congestion on tumor recurrence was subsequently completed. No significant difference in demographics was found. Group B had more elevated peak posttransplant levels of aspartate aminotransferase (296.26 versus 227.53, P = 0.05), alanine aminotransferase (382.91 versus 276.98, P = 0.04), and highly selective C-reactive protein (5.41 versus 3.55, P < 0.001); a higher noncongestive section regeneration rate (25.8% versus 13.6%, P = 0.012); and a higher recurrence rate (30.4% versus 9.7%, P = 0.01) than group A. Graft congestion > 10% [hazard ratio (HR) = 3.10, 95% confidence interval (CI) = 1.15-8.35, P = 0.03], microvascular invasion (HR = 5.43, 95% CI = 2.04-14.44, P < 0.01), and an alpha-fetoprotein level > 200 IU/L (HR = 2.98, 95% CI = 1.10-8.03, P = 0.03) were significantly related to tumor recurrence. Liver congestion may promote the recurrence of HCC after LDLT; therefore, it should be minimized. Liver Transpl 20:784-790, 2014. © 2014 AASLD.
Synthesis and Characterization of Polymerized Ionic Liquids: Mechanical and Thermal Properties of a Novel Type of Hydrogels
Authors: Bandomir Jenny , Schulz André , Taguchi Satomi , Schmitt Lena , Ohno Hiroyuki , Sternberg Katrin , Schmitz Klaus‐Peter , Kragl Udo
Published: March 2014

An easy and efficient route to synthesize gel materials based on polymeric ionic liquids (PILs) is presented. The radical polymerization of imidazolium (Im)‐based ionic liquids (ILs) bearing a vinyl group ([VEIm][Br], [VEIm][Ac], [VBIm][Br], [VBIm][Cl]) with crosslinker (CL) N,N′‐methylenebisacrylamide (Bis) in water results in polyionic liquid hydrogels. Thermal and mechanical properties (tensile and compression tests) are investigated and compared with two different types of hydrogels. One is a polyacrylamide (PAAm) hydrogel having covalent‐type crosslinking. The other is an alginate‐based hydrogel having ionic‐type crosslinking. Prepared IL‐hydrogel materials provide favorable flexibility, adjustable by varying the CL ratio and water content. The higher the CL ratio is, the higher the fragility of the gel matrix. The gelation time of the hydrogels depends on the alkyl chain length, as well as the size of the anion.

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CRKL promotes lung cancer cell invasion through ERK‐MMP9 pathway
Authors: Lin Fu , Chengyao Xie , Qingchang Li , Qianze Dong , Enhua Wang , Yan Wang
Published: March 2014

CRKL is recently defined as a new oncogene, which plays a role in the lung cancer progression. However, the potential mechanism of CRKL in human non‐small cell lung cancer cell invasion is obscure. We investigated the potential mechanism of CRKL in lung cancer cell invasion using immunohistochemistry, plasmid transfection, Western blotting, real‐time PCR, matrigel invasion assay, chromatin immunoprecipitation assay, and luciferase reporter assay. CRKL expression is higher in lymph node metastatic tumor compared with primary tumor. CRKL overexpression enhanced cell invasion and MMP9 expression in both HBE and H1299 cell lines. There was a significant correlation between CRKL overexpression and high MMP9 expression in primary tumors. MMP‐9 antibody treatment significantly blocked cell invasion. CRKL overexpression also activated AP‐1 luciferase reporter activity, ERK phosphorylation and association of c‐fos to MMP9 promoter. Treatment with ERK inhibitor PD98059 in cells with CRKL transfection inhibited ERK activity, cell invasion, and MMP9 expression. These results suggested that overexpression of CRKL promoted cell invasion through upregulation of MMP9 expression and activation of ERK pathway. © 2014 Wiley Periodicals, Inc.
Quantifying iron‐oxide nanoparticles at high concentration based on longitudinal relaxation using a three‐dimensional SWIFT look‐locker sequence
Authors: Zhang Jinjin , Chamberlain Ryan , Etheridge Michael , Idiyatullin Djaudat , Corum Curtis , Bischof John , Garwood Michael
Published: March 2014

Purpose

Iron‐oxide nanoparticles (IONPs) have proven utility as contrast agents in many MRI applications. Previous quantitative IONP mapping has been performed using mainly T2* mapping methods. However, in applications requiring high IONP concentrations, such as magnetic nanoparticles based thermal therapies, conventional pulse sequences are unable to map T2* because the signal decays too rapidly. In this article, sweep imaging with Fourier transformation (SWIFT) sequence is combined with the Look‐Locker method to map T1 of IONPs in high concentrations.

Methods

T1 values of agar containing IONPs in different concentrations were measured with the SWIFT Look‐Locker method and with inversion recovery spectroscopy. Precisions of Look‐Locker and variable flip angle (VFA) methods were compared in simulations.

Results

The measured R1 (=1/T1) has a linear relationship with IONP concentration up to 53.6 mM of Fe. This concentration exceeds concentrations measured in previous work by almost an order of magnitude. Simulations show SWIFT Look‐Locker method is also much less sensitive to B1 inhomogeneity than the VFA method.

Conclusion

SWIFT Look‐Locker can accurately measure T1 of IONP concentrations ≤53.6 mM. By mapping T1 as a function of IONP concentration, IONP distribution maps might be used in the future to plan effective magnetic nanoparticle hyperthermia therapy. Magn Reson Med 71:1982–1988, 2014. © 2014 Wiley Periodicals, Inc.
Integrating the self‐growing concept in a self‐organizing wireless network for topology optimization
Authors: Kousaridas Apostolos , Kaloxylos Alexandros , Magdalinos Panagis , Makris Thanos , Koudouridis Georgios , Hedby Gunnar , Alonistioti Nancy
Published: March 2014

The concept of self‐organizing networks is considered one of the most promising approaches for the efficient management of future wireless networks that will support a large number of nodes and a plethora of services with diverse characteristics. Today, different types of networks (e.g. WLANs, wireless sensor networks) are deployed to serve different needs but do not interoperate. Their possible loose integration will provide opportunities that could be exploited through collaborative approaches to devise novel solutions to extend the capabilities and improve the performance of these networks. The self‐growing paradigm addresses this challenge by extending network nodes to dynamically evolve in terms of purpose and operational features. In this paper we describe the CONSERN architecture, which targets the realization of the self‐growing concept in the context of self‐organized networks. To test our ideas we designed and implemented a WLAN topology optimization scheme that provides the best coverage at a minimum energy consumption, through dynamic access point (AP) deactivation and reactivation. Using self‐growing mechanisms and typical motion detectors we present how the operation of the proposed topology optimization mechanism can be improved. The reduced energy consumption attained under the proposed scheme at the AP side, as well as the efficient utilization of network resources, are evaluated via a proof‐of‐concept implementation that we have deployed in a real office environment that consists of WLAN APs and motion sensors. Copyright © 2014 John Wiley & Sons, Ltd.
RECOGNIZING PRIVILEGE: RURAL, URBAN, AND INTERNATIONAL PERSPECTIVES
Authors: Munn Sunny L. , Rinfret Sara , Davitt Kendra
Published: March 2014

Forms of White oppression in the United States are hierarchically evaluated through male‐dominated society. This paper concentrates on a different perspective—White, female privilege through the experiences and self‐reflections of narratives from three geographical perspectives—rural, urban, and international. Within the theoretical frameworks of place and geography these stories come to life through an autoethnographic approach to establish that we can “unpack the invisible knapsack” in the arena of adult education.
Concept Maps: Practice Applications in Adult Education and Human Resource Development
Authors: Daley Barbara J.
Published: March 2014

Concept maps can be used as both a cognitive and constructivist learning strategy in teaching and learning in adult education and human resource development. The maps can be used to understand course readings, analyze case studies, develop reflective thinking and enhance research skills. The creation of concept maps can also be supported by the use of the CmapTools software.
Tandem high‐dose chemotherapy and autologous stem cell rescue in children with newly diagnosed high‐risk medulloblastoma or supratentorial primitive neuro‐ectodermic tumors
Authors: Dufour Christelle , Kieffer Virginie , Varlet Pascale , Raquin Marie Anne , Dhermain Frederic , Puget Stephanie , Valteau‐Couanet Dominique , Grill Jacques
Published: March 2014

Background

To assess the feasibility and effectiveness of high‐dose chemotherapy (HDC) with stem cell support followed by conventional craniospinal radiotherapy (RT) as treatment for children older than 5 years of age with newly diagnosed high‐risk medulloblastoma (MB) or supratentorial PNET (sPNET).

Procedure

Between May 2001 and April 2010, 24 children older than 5 years of age (MB = 21; sPNET = 3), fulfilling inclusion criteria at diagnosis, were treated at Gustave Roussy. After conventional chemotherapy, they received two courses of high‐dose thiotepa (600 mg/m2) followed by craniospinal RT.

Results

The median follow‐up was 4.4 years (range, 0.8–11.3 years). For children with metastatic MB, the 5‐year event‐free survival (EFS) and overall survival (OS) were 72% and 83%, respectively. The toxicity was manageable. No toxic death occurred. At the most recent evaluation, among the 24 children who had at least one Full Scale Intellectual Quotient (FSIQ) examination at a median follow‐up of 3.79 years after diagnosis, the mean estimated FSIQ was 82 (range, 56–114).

Conclusions

In children with metastatic MB, tandem HDCT with ASCT followed by conventional craniospinal RT proved its feasibility without jeopardizing survival. Pediatr Blood Cancer 2014; 61:1398–1402. © 2014 Wiley Periodicals, Inc.
Instrumental variable applications using nursing home prescribing preferences in comparative effectiveness research
Authors: Huybrechts Krista F. , Gerhard Tobias , Franklin Jessica M. , Levin Raisa , Crystal Stephen , Schneeweiss Sebastian
Published: March 2014

Purpose

Nursing home residents are of particular interest for comparative effectiveness research given their susceptibility to adverse treatment effects and systematic exclusion from trials. However, the risk of residual confounding because of unmeasured markers of declining health using conventional analytic methods is high. We evaluated the validity of instrumental variable (IV) methods based on nursing home prescribing preference to mitigate such confounding, using psychotropic medications to manage behavioral problems in dementia as a case study.

Methods

A cohort using linked data from Medicaid, Medicare, Minimum Data Set, and Online Survey, Certification and Reporting for 2001–2004 was established. Dual‐eligible patients ≥65 years who initiated psychotropic medication use after admission were selected. Nursing home prescribing preference was characterized using mixed‐effects logistic regression models. The plausibility of IV assumptions was explored, and the association between psychotropic medication class and 180‐day mortality was estimated.

Results

High‐prescribing and low‐prescribing nursing homes differed by a factor of 2. Each preference‐based IV measure described a substantial proportion of variation in psychotropic medication choice (β(IV → treatment): 0.22‐0.36). Measured patient characteristics were well balanced across patient groups based on instrument status (52% average reduction in Mahalanobis distance). There was no evidence that instrument status was associated with markers of nursing home quality of care.

Conclusion

Findings indicate that IV analyses using nursing home prescribing preference may be a useful approach in comparative effectiveness studies, and should extend naturally to analyses including untreated comparison groups, which are of great scientific interest but subject to even stronger confounding. Copyright © 2014 John Wiley & Sons, Ltd.
Species differences in sinusoidal and canalicular efflux transport of mycophenolic acid 7‐O‐glucuronide in sandwich‐cultured hepatocytes
Authors: Tetsuka Kazuhiro , Gerst Nicolas , Tamura Kouichi , Masters Jeffrey N.
Published: March 2014

Metabolism and sinusoidal/canalicular efflux of mycophenolic acid (MPA) was investigated using sandwich‐cultured hepatocytes (SCHs). After applying MPA to SCHs from humans, wild‐type rats, and multidrug resistance‐associated protein (Mrp) 2‐deficient rats, the MPA metabolites 7‐O‐glucuronide (MPAG) and acyl glucuronide (AcMPAG) were detected in the intracellular compartment of the SCHs. Sinusoidal efflux of MPAG was detected in all SCH preparations including Mrp2‐deficient rat SCHs, whereas canalicular efflux of MPAG was observed in wild‐type rat and human SCHs but not in Mrp2‐deficient rat SCHs. The ratio of canalicular efflux to net (canalicular plus sinusoidal) efflux was 37 ± 8% in wild‐type rat SCHs, while the ratio in human SCHs was significantly lower (20 ± 2%, P < 0.05), indicating species differences in the direction of hepatic MPAG transport. This 20% ratio in human SCHs corresponds to a high sinusoidal MPAG efflux (80%) that can in part account for the urine‐dominated recovery of MPAG in humans. Both sinusoidal and canalicular MPAG efflux in rat SCHs shows a good correspondence to urinary and biliary recovery of MPAG after MPA dosing. The sinusoidal efflux of AcMPAG in human SCHs was detected from one out of three donors, suggesting donor‐to‐donor variation. In conclusion, this study demonstrates the predictive value of SCHs for elucidating the interplay of metabolism and efflux transport, in addition to demonstrating a species difference between rat and human in sinusoidal and canalicular efflux of MPAG.
Low dark current and stable ultraviolet avalanche photodiode of organic (PEDOT:PSS)‐inorganic (ZnSSe) hybrid junction structure
Authors: Abe Tomoki , Ikadatsu Noriyuki , Inoue Ryoichi , Fujimoto Takeru , Tanaka Kenta , Tazue Akio , Inagaki Yusuke , Ebisu Masahiro , Kasada Hirofumi , Ando Koshi
Published: March 2014

We have developed organic‐inorganic hybrid avalanche photodiode (APD) with conducting polymer as a window layer on ZnSSe/n‐GaAs wafers. APD wafers used in this study were grown by molecular beam epitaxy (MBE). We used PEDOT:PSS as hole‐transport conducting polymer window layers formed by inkjet method. We have succeeded in fabrication of low dark current and stable ultraviolet hybrid APDs. The present device has exhibited very low voltage APD operation at 29 V and extremely low dark current of 10–11 A/mm2 in the avalanche breakdown region. The APD device also has shown maximum multiplication factor of 45 and high sensitivity ∼ 3 A/W at the ultraviolet region (∼ 300 nm). A stable device operation is established using polyimide passivation and sealed into package with N2 atmosphere. We also demonstrated integrated devices operation in PIN mode. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison in internal strain sensitivity between polariscopy and Raman scattering spectroscopy in a (110)‐oriented ZnTe single crystal
Authors: Takeuchi Hideo
Published: March 2014

We present the experimental fact that, in a (110)‐oriented ZnTe single crystal, polariscopy is highly sensitive to the internal strain, comparing with Raman scattering spectroscopy. We utilized X‐ray topography and X‐ray diffraction analysis to thoroughly investigate the crystal structure that is intimately associated with the internal strain. The two X‐ray structure analyses clarified that the misalignment from the [110] direction is formed in some regions. We obtained the following main result: The polariscopic analysis detects the internal strain formed by the misalignment, whereas the Raman scattering measurement is insensitive to the internal strain. We, therefore, conclude that polariscopy has the strain‐detection sensitivity higher than the Raman scattering spectroscopy. We have confirmed that the polariscopic analysis can detect the internal strain less than 0.5% in the ZnTe crystal. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of hydrogen partial pressure on growth of Cu2ZnSnS4 films sulfurized using diethyl sulfide
Authors: Tahashi Masahiro , Yamada Ryota , Ito Hiroaki , Yoshino Kenji , Takahashi Makoto , Goto Hideo
Published: March 2014

Polycrystalline Cu2ZnSnS4 films were prepared by thermal treatment of stacked Sn/Zn/Cu metallic precursors in the presence of diethyl sulfide, which is a less hazardous sulfur source than H2S gas. The effect of the hydrogen partial pressure on the crystal phases present in the films was investigated. It was found that sulfur and carbon atoms play an important role in film growth. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of substrate temperature upon the compositions of Mg and Se in Zn1‐xMgx Sey Te1‐y layer grown by MOVPE
Authors: Nishio M. , Saito K. , Ito R. , Tanaka K. , Urata K. , Nakamura Y. , Tanaka T. , Guo Q. X.
Published: March 2014

The growth of Zn1‐xMgx Sey Te1‐y layers was performed on (100) ZnTe substrate by metalorganic vapour phase epitaxy using dimethylzinc, bis‐methylcyclopentadienyl‐magnesium, diethyltelluride and diethylselenide. The effects of substrate temperature upon the compositions of Mg and Se have been investigated. The Mg composition in Zn1‐xMgx Sey Te1‐y layer is significantly enhanced at low substrate temperature. Although the Se composition decreases with decreasing the substrate temperature, Zn1‐xMgx Sey Te1‐y layer with a relatively high Se composition of 0.3 is obtainable at a low substrate temperature as low as 380 ºC. For all the layers, a two‐mode behaviour with ZnTe‐ and MgTe‐like longitudinal optical phonon modes is confirmed by Raman scattering. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of surface morphology on the field emission property of ZnO films
Authors: Zulkifli Zurita , Munisamy Subramanian , Yusop Mohd Zamri Mohd , Tanemura Masaki
Published: March 2014

Stable and high crystalline quality of ZnO nanocones have been successfully fabricated on glass substrates at room temperature. In 3 min irradiation by argon ion on ZnO thin film surface, ZnO nanocones with a number density of 8‐15 µm‐2 can be observed from SEM images. For a high performance of field emission (FE) device, an emission current stability test was carried out at a fixed electric field of 12 V/µm for 60 min. A stable current of 2.5 µA was observed after 30 min without any obvious irregular current flow. The current density of 1 µA cm‐2 was achieved at 9.8 V/µm and 7.8 V/µm before and after stability test, respectively. Even though some of the ZnO nanocones tip were melted due to Joule heating induced by high intensity of electric field, the field enhancement factor are still comparable with other types of nanostructure emitters. The surface morphology of ZnO nanocones after the stability test showed the nanocones of shorter length are not affected by the high electric field at the emission area in which this revealed the robustness of ZnO compared to CNTs/CNFs. The ZnO nanocones at out of the emission area are also not affected by the high electric field or by any heat generated in the vacuum chamber during field emission. Thus, due to the high thermal and mechanical stability, ZnO nanocones is reliable to be as a promising field emitter. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of p‐contact layers for BeZnSeTe/MgZnCdSe optical devices on InP substrates
Authors: Takamatsu Shingo , Nomura Ichirou , Kobayashi Toshiki , Murakami Keisuke , Shiraishi Tomohiro , Kishino Katsumi
Published: March 2014

ZnTe and ZnSeTe p‐contact layers were investigated for use in BeZnSeTe/MgZnCdSe optical devices on InP sub‐strates. The contact resistances (Rc) of Au electrodes to N‐doped p‐ZnTe and p‐ZnSeTe contact lay‐ers were evaluated using the circular transmission line model (c‐TLM) method. A lower Rc (3.1×10‐3 Ωcm2) was obtained for the ZnSeTe p‐contact sample than for the ZnTe sample (6.3×10‐3 Ωcm2). BeZnSeTe/MgZnCdSe yellow‐light‐emitting devices with a ZnTe or ZnSeTe p‐contact layer grown on InP substrates were characterized. A comparison of the current‐voltage (I‐V) characteristics of these devices showed that the turn‐on voltage of the ZnSeTe contact device was about 4 V lower than that of the ZnTe device. From the aging characteristics of these devices under direct‐current injection at room temperature, it was shown that the lifetime of the ZnSeTe contact device was 30 times longer than that of the ZnTe contact device. These results show that a ZnSeTe contact layer is more suitable for BeZnSeTe/MgZnCdSe optical devices on InP substrates than a ZnTe contact layer. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of charged defects for substitutionally doped chromium in hexagonal barium titanate from first‐principles theory
Authors: Nayak Sanjeev K. , Adeagbo Waheed A. , Langhammer Hans T. , Hergert Wolfram , Müller Thomas , Böttcher Rolf
Published: March 2014

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We have studied the defect properties of substitutionally doped chromium in hexagonal barium titanate using the density functional theory together with the generalized gradient approximation restricted to exclusively electronic compensation of the charged defect. The supercell used in our studies is large enough to mimic a chromium concentration of about 2 mol%, which corresponds to an amount typically applied in experiments. Chromium is found to prefer the Ti sites inside the face‐sharing oxygen octahedra compared with the other non‐equivalent Ti sites within the exclusively corner‐sharing octahedra of the hexagonal host lattice. Analysis of formation energy, derived from the total energies of defective supercells in various charge states and systematic post‐processing, shows that the charge state of –1 is stable for wide range of Fermi energy within the band gap. The charge state of 0 is only stable for a very low electron concentration, i.e. for highly oxidizing conditions. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of increased convective entrainment on Asian monsoon biases in the MetUM general circulation model
Authors: Bush Stephanie J. , Turner Andrew G. , Woolnough Steven J. , Martin Gill M. , Klingaman Nicholas P.
Published: March 2014

We demonstrate that summer precipitation biases in the South Asian monsoon domain are sensitive to increasing the convective parametrization's entrainment and detrainment rates in the Met Office Unified Model. We explore this sensitivity to improve our understanding of the biases and inform efforts to improve convective parametrization. We perform novel targeted experiments in which we increase the entrainment and detrainment rates in regions of especially large precipitation bias. We use these experiments to determine whether the sensitivity at a given location is a consequence of the local change to convection or is a remote response to the change elsewhere. We find that a local change leads to different mean‐state responses in comparable regions. When the entrainment and detrainment rates are increased globally, feedbacks between regions usually strengthen the local responses. We choose two regions of tropical ascent that show different mean‐state responses, the western equatorial Indian Ocean and western north Pacific, and analyse them as case‐studies to determine the mechanisms leading to the different responses. Our results indicate that several aspects of a region's mean state, including moisture content, sea surface temperature and circulation, play a role in local feedbacks which determine the response to increased entrainment and detrainment.
Bias in parametric estimation: reduction and useful side‐effects
Authors: Kosmidis Ioannis
Published: March 2014

The bias of an estimator is defined as the difference of its expected value from the parameter to be estimated, where the expectation is with respect to the model. Loosely speaking, small bias reflects the desire that if an experiment is repeated indefinitely then the average of all the resultant estimates will be close to the parameter value that is estimated. The current article is a review of the still‐expanding repository of methods that have been developed to reduce bias in the estimation of parametric models. The review provides a unifying framework where all those methods are seen as attempts to approximate the solution of a simple estimating equation. Of particular focus is the maximum likelihood estimator, which despite being asymptotically unbiased under the usual regularity conditions, has finite‐sample bias that can result in significant loss of performance of standard inferential procedures. An informal comparison of the methods is made revealing some useful practical side‐effects in the estimation of popular models in practice including: (1) shrinkage of the estimators in binomial and multinomial regression models that guarantees finiteness even in cases of data separation where the maximum likelihood estimator is infinite and (2) inferential benefits for models that require the estimation of dispersion or precision parameters.

This article is categorized under:

Data: Types and Structure > Categorical Data

Algorithms and Computational Methods > Maximum Likelihood Methods

Statistical and Graphical Methods of Data Analysis > Bootstrap and Resampling
The engineering of artificial cellular nanosystems using synthetic biology approaches
Authors: Wu Fan , Tan Cheemeng
Published: March 2014

Artificial cellular systems are minimal systems that mimic certain properties of natural cells, including signaling pathways, membranes, and metabolic pathways. These artificial cells (or protocells) can be constructed following a synthetic biology approach by assembling biomembranes, synthetic gene circuits, and cell‐free expression systems. As artificial cells are built from bottom‐up using minimal and a defined number of components, they are more amenable to predictive mathematical modeling and engineered controls when compared with natural cells. Indeed, artificial cells have been implemented as drug delivery machineries and in situ protein expression systems. Furthermore, artificial cells have been used as biomimetic systems to unveil new insights into functions of natural cells, which are otherwise difficult to investigate owing to their inherent complexity. It is our vision that the development of artificial cells would bring forth parallel advancements in synthetic biology, cell‐free systems, and in vitro systems biology.

This article is categorized under:

Nanotechnology Approaches to Biology > Cells at the Nanoscale

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
The multifaceted roles of RNA binding in APOBEC cytidine deaminase functions
Authors: Prohaska Kimberly M. , Bennett Ryan P. , Salter Jason D. , Smith Harold C.
Published: March 2014

Cytidine deaminases have important roles in the regulation of nucleoside/deoxynucleoside pools for DNA and RNA synthesis. The APOBEC family of cytidine deaminases (named after the first member of the family that was described, Apolipoprotein B mRNA Editing Catalytic Subunit 1, also known as APOBEC1 or A1) is a fascinating group of mutagenic proteins that use RNA and single‐stranded DNA (ssDNA) as substrates for their cytidine or deoxycytidine deaminase activities. APOBEC proteins and base‐modification nucleic acid editing have been the subject of numerous publications, reviews, and speculation. These proteins play diverse roles in host cell defense, protecting cells from invading genetic material, enabling the acquired immune response to antigens and changing protein expression at the level of the genetic code in mRNA or DNA. The amazing power these proteins have for interphase cell functions relies on structural and biochemical properties that are beginning to be understood. At the same time, the substrate selectivity of each member in the family and their regulation remains to be elucidated. This review of the APOBEC family will focus on an open question in regulation, namely what role the interactions of these proteins with RNA have in editing substrate recognition or allosteric regulation of DNA mutagenic and host‐defense activities. WIREs RNA 2014, 5:493–508. doi: 10.1002/wrna.1226

This article is categorized under:

RNA Interactions with Proteins and Other Molecules > Protein–RNA Recognition

RNA Interactions with Proteins and Other Molecules > Small Molecule–RNA Interactions

RNA Processing > RNA Editing and Modification

Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs
Synthesis and Structural Characterization of 1D and 2D Coordination Polymers based on Flexible 1, 3‐Adamantanediacetic Acid and Exo‐bidentate Organic Linkers
Authors: Haldar Ritesh , Maji Tapas Kumar
Published: March 2014

Five mixed‐linkers based coordination polymers, namely {M(1, 3‐Hadc)(bpy)(H2O)2}n [M = NiII (1), CoII (2)], {Zn(1, 3‐adc)(bpy)0.5}n (3), {Cd(1, 3‐Hadc)2(bpy)}n (4), and {Cu(1, 3‐Hadc)2(bpp)}n (5) [1, 3‐H2adc = 1, 3‐adamantanediacetic acid, bpy = 4, 4′‐bipyridine, bpp = 1, 3‐bis(4‐pyridyl)propane] were synthesized by solvent diffusion reactions. Their structures were determined by single‐crystal X‐ray diffraction analyses. Compounds 1 and 2 are isostructural and they have 1D linear coordination polymer structure that are further interdigitated via hydrogen bonding resulting in 2D extended networks. The dehydrated 1 shows type‐I profile for H2O vapor suggesting hydrophilic nature of the framework. In compound 3, a paddle‐wheel type secondary building unit (SBU) directs the overall structure to form a 2D square grid type structure. The 2D sheets further stack along the c axis in a AB fashion and leaves no void space. Compound 4 has a hexacoordinate CdII and forms a zigzag coordination polymer chain‐like structure and these chains form a 2D structure by hydrogen bonding interactions. Compound 5 contains a longer linker bpp compared to bpy and forms a 2D structure similar to that of 4. These results demonstrate that by changing the metal ions coordination mode versatile structures with different dimensionalities and network topologies can be realized in a same mixed linkers system.
Enhanced Recovery Pathway for Urgent Colectomy
Authors: Roulin Didier , Blanc Catherine , Muradbegovic Mirza , Hahnloser Dieter , Demartines Nicolas , Hübner Martin
Published: March 2014

Background

Enhanced recovery protocols have been proven to decrease complications and hospital stay following elective colorectal surgery. However, these principles have not yet been reported for urgent surgery procedures. We aimed to assess our initial experience with urgent colectomies performed within an established enhanced recovery pathway.

Methods

In a prospective cohort study, all patients undergoing colonic resection between April 2012 and March 2013 were treated according to a standardized enhanced recovery protocol. Urgent surgeries were compared with the elective procedures with regards to baseline characteristics, compliance with enhanced recovery items, and clinical outcome.

Results

Patients (N = 28) requiring urgent colonic resection were included and compared with patients undergoing elective colectomy (N = 63). Overall compliance with the protocol was 57 % for the urgent compared with 77 % for the elective procedures (p = 0.006). The pre‐operative compliance was 64 versus 96 % (p < 0.001), the intra‐operative compliance was 77 versus 86 % (p = 0.145), and the post‐operative compliance was 49 versus 67 % (p = 0.015), for the urgent and elective resections, respectively. Overall, 18 urgent patients (64 %) and 32 elective patients (51 %) developed postoperative complications (p = 0.261). Median postoperative length of stay was 8 days in the urgent setting compared with 5 days in the elective setting (p = 0.006).

Conclusions

Many of the intra‐operative and post‐operative enhanced recovery items can also be applied to urgent colectomy, entailing outcomes that approach the results achieved in the elective setting.