bluuebunny/crossref_metadata_2025 huggingface dataset:
Locational tying of complementary retail items
Authors: Maddah Bacel , Bish Ebru K.
Published: May 2009

We study a selling practice that we refer to as locational tying (LT), which seems to be gaining wide popularity among retailers. Under this strategy, a retailer “locationally ties” two complementary items that we denote by “primary” and “secondary.” The retailer sells the primary item in an appropriate “department” of his or her store. To stimulate demand, the secondary item is offered in the primary item's department, where it is displayed in very close proximity to the primary item. We consider two variations of LT: In the multilocation tying strategy (LT‐M), the secondary item is offered in its appropriate department in addition to the primary item's department, whereas in the single‐location tying strategy (LT‐S), it is offered only in the primary item's location. We compare these LT strategies to the traditional independent components (IC) strategy, in which the two items are sold independently (each in its own department), but the pricing/inventory decisions can be centralized (IC‐C) or decentralized (IC‐D). Assuming ample inventory, we compare and provide a ranking of the optimal prices of the four strategies. The main insight from this comparison is that relative to IC‐D, LT decreases the price of the primary item and adjusts the price of the secondary item up or down depending on its popularity in the primary item's department. We also perform a comparative statics analysis on the effect of demand and cost parameters on the optimal prices of various strategies, and identify the conditions that favor one strategy over others in terms of profitability. Then we study inventory decisions in LT under exogenous pricing by developing a model that accounts for the effect of the primary item's stock‐outs on the secondary item's demand. We find that, relative to IC‐D, LT increases the inventory level of the primary item. We also link the profitability of different strategies to the trade‐off between the increase in demand volume of the secondary item as a result of LT and the potential increase in inventory costs due to decentralizing the inventory of the secondary item. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009
Quality control chart design under Jidoka
Authors: Berk Emre , Toy Ayhan Özgür
Published: May 2009

We consider design of control charts in the presence of machine stoppages that are exogenously imposed (as under jidoka practices). Each stoppage creates an opportunity for inspection/repair at reduced cost. We first model a single machine facing opportunities arriving according to a Poisson process, develop the expressions for its operating characteristics and construct the optimization problem for economic design of a control chart. We, then, consider the multiple machine setting where individual machine stoppages may create inspection/repair opportunities for other machines. We develop exact expressions for the cases when all machines are either opportunity‐takers or not. On the basis of an approximation for the all‐taker case, we then propose an approximate model for the mixed case. In a numerical study, we examine the opportunity taking behavior of machines in both single and multiple machine settings and the impact of such practices on the design of an X – Q C chart. Our findings indicate that incorporating inspection/repair opportunities into QC chart design may provide considerable cost savings. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009
Optimal search for a moving target with the option to wait
Authors: Flesch János , Karagözoǧlu Emin , Perea Andrés
Published: May 2009

We investigate the problem in which an agent has to find an object that moves between two locations according to a discrete Markov process (Pollock, Operat Res 18 (1970) 883–903). At every period, the agent has three options: searching left, searching right, and waiting. We assume that waiting is costless whereas searching is costly. Moreover, when the agent searches the location that contains the object, he finds it with probability 1 (i.e. there is no overlooking). Waiting can be useful because it could induce a more favorable probability distribution over the two locations next period. We find an essentially unique (nearly) optimal strategy, and prove that it is characterized by two thresholds (as conjectured by Weber, J Appl Probab 23 (1986) 708–717). We show, moreover, that it can never be optimal to search the location with the lower probability of containing the object. The latter result is far from obvious and is in clear contrast with the example in Ross (1983) for the model without waiting. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009
A branch‐and‐cut algorithm for the nonpreemptive swapping problem
Authors: Bordenave Charles , Gendreau Michel , Laporte Gilbert
Published: May 2009

In the Swapping Problem (SP), we are given a complete graph, a set of object types, and a vehicle of unit capacity. An initial state specifies the object type currently located at each vertex (at most one type per vertex). A final state describes where these object types must be repositioned. In general, there exist several identical objects for a given object type, yielding multiple possible destinations for each object. The SP consists of finding a shortest vehicle route starting and ending at an arbitrary vertex, in such a way that each object is repositioned in its final state. This article exhibits some structural properties of optimal solutions and proposes a branch‐and‐cut algorithm based on a 0‐1 formulation of the problem. Computational results on random instances containing up to 200 vertices and eight object types are reported. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009
Convergence bounds of GMRES with Schwarz' preconditioner for the scattering problem
Authors: Ben Belgacem Faker , Gmati Nabil , Jelassi Faten
Published: May 2009

We consider the Jacobi preconditioner of the GMRES method introduced by Liu and Jin for the scattering problem (IEEE Trans. Ante. Prop. 2002; 50:132–140). We explain why it is a particular form of the Schwarz' preconditioner with a complete overlap and specific transmission conditions. So far, a superlinear convergence has been predicted by the general theory without any additional indication on the convergence rates. Here, we establish error bounds that provide accurate convergence rates in two and three dimensions. Courant–Weyl's min–max principle applied to some kernel operators together with some polynomial approximation estimates are the milestones for the proofs. Copyright © 2009 John Wiley & Sons, Ltd.
Assessment of preferences for treatment: Validation of a measure
Authors: Sidani Souraya , Epstein Dana R. , Bootzin Richard R. , Moritz Patricia , Miranda Joyal
Published: May 2009

Systematic measurement of treatment preferences is needed to obtain well‐informed preferences. Guided by a conceptualization of treatment preferences, a measure was developed to assess treatment acceptability and preference. The purpose of this study was to evaluate the psychometric properties of the treatment acceptability and preferences (TAP) measure. The TAP measure contains a description of each treatment under evaluation, items to rate its acceptability, and questions about participants' preferred treatment option. The items measuring treatment acceptability were internally consistent (alpha > .80) and demonstrated validity, evidenced by a one‐factor structure and differences in the scores between participants with preferences for particular interventions. The TAP measure has the potential for the assessment of acceptability and preferences for various behavioral interventions. © 2009 Wiley Periodicals, Inc. Res Nurs Health 32: 419–431, 2009
Intimate partner physical and mental health after sudden cardiac arrest and receipt of an implantable cardioverter defibrillator
Authors: Dougherty Cynthia M. , Thompson Elaine A.
Published: May 2009

The purpose of this study was to describe the physical and mental health of the intimate partners of persons receiving an implantable cardioverter defibrillator (ICD). A prospective longitudinal repeated measures design was used, with data collected at hospital discharge, and at 1, 3, 6, and 12 months after implantation. Intimate partners' physical health, symptoms, and depression significantly declined over the first year. Although anxiety was significantly reduced over time, it remained elevated in partners after 1 year. The impact of implantation of the ICD on the intimate relationship and care demands was most dramatic at hospital discharge. Health care use was low throughout the year. Intimate partners could benefit from an intervention that would assist in their psychological adjustment and provide strategies for dealing with caregiving demands at home. © 2009 Wiley Periodicals, Inc. Res Nurs Health 32: 432–442, 2009
Counteracting ambivalence: Nurses who smoke and their health promotion role with patients who smoke
Authors: Radsma Jenny , Bottorff Joan L.
Published: May 2009

Morbidity and mortality associated with smoking are major health problems. Nurses play an instrumental role in tobacco reduction, but their own smoking often interferes with this clinical opportunity. We conducted a grounded theory study with 23 nurses who smoked to describe how they managed the contradictions encountered when caring for tobacco‐dependent patients. Nurses counteracted ambivalence in one of four ways in relation to smoking policies: indifferent, evasive, engaged, and forced compliance. Influencing these approaches were nurses' perceptions of patients' need for tobacco‐dependence interventions and perceptions of their own vulnerability in addressing tobacco use. The challenge remains how best to support smoking nurses to enable them to become unambivalent participants in preventing and reducing tobacco dependence in their patients and themselves. © 2009 Wiley Periodicals, Inc. Res Nurs Health 32: 443–452, 2009
Social support, life stress, and anxiety as predictors of pregnancy complications in low‐income women
Authors: Zachariah Rachel
Published: May 2009

Prospective repeated measures were used to examine attachment, social support, life stress, anxiety, and psychological wellbeing among low‐income women in early and late pregnancy and the relationships of these variables to prenatal, intrapartum, and neonatal complications. One hundred and eleven medically healthy, low‐income, Medicaid‐eligible women ages 18–35 years, between 14 and 22 weeks of pregnancy were recruited from prenatal clinics. Self‐report questionnaires and hospital records were used to collect data. Discriminant analysis was performed. The most important discriminating factors for prenatal complications were state anxiety and total functional social support. The factors for neonatal complications were negative life events and the interaction of emotional support with negative life events. © 2009 Wiley Periodicals, Inc. Res Nurs Health 32: 391–404, 2009
Familial retinoblastoma in developing countries
Authors: Chantada Guillermo L. , Dunkel Ira J. , Qaddoumi Ibrahim , Antoneli Celia B.G. , Totah Alegria , Canturk Serife , Nawaiseh Ibrahim , Fandiño Adriana , Pífano Imelda , Peksayar Gonul , Ribeiro Karina Braga , Abramson David H.
Published: May 2009

Background

Although screening for familial retinoblastoma has been shown to be beneficial we suspected that such screening programs may be less than optimal in developing countries (DC).

Methods

Retrospective cohort study comparing patients with familial retinoblastoma from five centers in DC (Argentina, Brazil, Turkey, Jordan, and Venezuela) versus a reference center in the USA.

Results

Ninety‐two (32 from the USA and 60 from DC) patients were included. Forty‐one (44.6%) patients avoided enucleation, 42 (45.7%) had 1 eye removed, and 9 (9.8%) underwent bilateral enucleation. Eleven (11.9%) had major pathology risk factors at enucleation. There were no cases of metastatic disease at diagnosis. Detection via screening was significantly less common in DC than in the USA (23.3% vs. 71.8%, P < 0.0001). Patients in DC were diagnosed at a significantly later age and with more advanced intraocular disease that led to increased risk of bilateral enucleation. Patients detected by screening in DC were significantly younger at diagnosis, had less advanced intraocular disease, better ocular preservation rates and survival results than those whose retinoblastoma was not detected via early screening. Five‐year pEFS was 0.92 for the patients treated in the USA and 0.81 for the patients in DC (P = 0.42). Seven events occurred (extraocular relapse four in patients from DC and second malignancies in three).

Conclusions

Patients with familial retinoblastoma are less likely to be diagnosed by screening in DC and had higher morbidity and mortality caused by recurrent extraocular retinoblastoma. Pediatr Blood Cancer 2009;53:338–342. © 2009 Wiley‐Liss, Inc.
Secondary supratentorial primitive neuroectodermal tumor following treatment of childhood osteosarcoma
Authors: Fitzhugh Courtney D. , Wise Barbara , Baird Kristin , Tsokos Maria , Helman Lee , Mackall Crystal , Savage Sharon A. , Warren Katherine E.
Published: May 2009

A 16‐year‐old Caucasian male was diagnosed with a primitive neuroectodermal tumor (PNET) 5 years following the diagnosis of nonmetastatic osteosarcoma of the left proximal humerus. The patient was initially treated with standard chemotherapy and limb salvage resection for osteosarcoma. Nine months after the completion of therapy, he developed lung metastases for which he underwent surgical resection and received additional chemotherapy. Almost 5 years after the osteosarcoma diagnosis, the patient was diagnosed with a supratentorial PNET, which represents the first known case reported in a patient with osteosarcoma. Pediatr Blood Cancer 2009;53:496–498. Published 2009 Wiley‐Liss, Inc.
Risk factors for visual impairment registration due to diabetic retinopathy in Leeds, 2002–2005
Authors: Hayat H , Bodansky HJ , Nayak D , Ashiq A , McKibbin M , Goyder E
Published: May 2009

We undertook a retrospective study of case notes of those patients registered blind or partially sighted due to diabetic retinopathy in the Leeds metropolitan area in the years 2002 and 2005.

Both the incidence of visual impairment due to diabetic retinopathy and the relative contribution to total registrations are similar to those observed in other local and national studies. The main risk factors for registered visual impairment were poor glycaemic control prior to ophthalmic review, no prior retinopathy screening, late presentation with symptomatic visual loss, non‐compliance with planned review and laser treatment failure. Most of these risk factors are avoidable. Nearly two‐thirds of patients diagnosed with diabetes mellitus were being screened for diabetic retinopathy. These figures would suggest that the National Service Framework for Diabetes' proposed coverage of 80% by 2006 and 100% by the end of 2007 is achievable. The duration of diagnosed diabetes mellitus at the time of registration was an average of 16 years in this study. This reflects the slow development of sight‐threatening retinopathy and visual loss observed previously. Conventional therapy for diabetic retinopathy with laser photocoagulation reduces the risk of visual loss more effectively than it improves visual function. Despite the increased risk of early worsening of retinopathy seen with intensive glycaemic control in the Diabetes Control and Complications Trial and the UK Prospective Diabetes Study, improved control closer to the time of diagnosis of diabetes mellitus would have helped to provide a sustained reduction in the risk of retinopathy developing or progressing. Both laser treatment failure and non‐attendance may limit the benefits of improved screening coverage. Copyright © 2009 John Wiley & Sons.
Guidelines on the current best practice for the management of type 1 diabetes, sport and exercise
Authors: Perry E , Gallen IW
Published: May 2009

With the overwhelming health benefits of regular exercise and the increasing recognition that individuals with type 1 diabetes can compete in all types of sport and exercise at all levels, there is increasing demand for evidence‐based guidance on the management of type 1 diabetes, sport and exercise.

Although there have been a number of recent studies advancing our understanding of possible management strategies, there is currently little in the way of practical guidance available for health care professionals.

This article aims to empower health care professionals working in clinical practice within the field of type 1 diabetes, sport and exercise. The first section of the article summarises the physiological challenges to glucose homeostasis anticipated from different types of exercise in an individual with type 1 diabetes. The second section considers the current evidence base and recognised strategies available to overcome these physiological challenges.

Although this article does not cover ‘every insulin regimen’ or ‘every eventuality’ it provides health care professionals with the knowledge to predict the impact of different sports and exercises on glucose homeostasis in an individual with type 1 diabetes, and an awareness of the potential strategies available to allow safe and successful participation in sport and exercise without compromise to glycaemic control. Copyright © 2009 John Wiley & Sons.
Treatment refusal and abandonment in childhood acute lymphoblastic leukemia in Indonesia: an analysis of causes and consequences
Authors: Sitaresmi Mei Neni , Mostert Saskia , Schook Romane Milia , Sutaryo  , Veerman Anjo J. P.
Published: May 2009

Background: Treatment refusal and abandonment are common causes of treatment failure in childhood acute lymphoblastic leukemia (ALL) in many developing countries. In most studies reasons for abandonment were based on the opinion of health‐care providers (HCP), very few studies have focused on the parental point‐of‐view. Aims of the study were to analyze the parents' reasons of abandonment and to ascertain the fate of children who abandoned treatment in a pediatric oncology centre in Yogyakarta, Indonesia.

Methods: We conducted home‐visits to interview families of ALL patients, diagnosed between January 2004 and August 2007, who refused or abandoned treatment.

Results: From January 2004 to August 2007, 159 patients were diagnosed with ALL of which 40 children (25%) refused or abandoned therapy. Thirty‐seven (93%) of these children were home‐visited. Reasons for abandonment were complex. Most parents mentioned several reasons. Financial and transportation difficulties were not the only, or even the main reasons, for abandonment. Belief of ALL incurability, experience of severe side effects and dissatisfaction with HCP were also important considerations. Most patients (64%) abandoned treatment during the diagnostic‐evaluation or remission‐induction phase. Of the 37 patients who refused or abandoned treatment, 26 (70%) children died, and 11 (30%) children were still alive, 2 of them more than 2 years after abandonment.

Conclusions: Reducing treatment abandonment of childhood ALL in developing countries requires not only financial and transportation support, but also parental education, counseling and psychosocial support during therapy, improvement of quality‐of‐care and adequate management of side effects. Copyright © 2009 John Wiley & Sons, Ltd.
Gorham–Stout Syndrome with chylothorax: Successful remission by interferon alpha‐2b
Authors: Kose Mehmet , Pekcan Sevgi , Dogru Deniz , Akyuz Canan , Ozcelik Ugur , Ozsurekci Yasemin , Gulhan Bora , Demircin Metin , Kiper Nural
Published: May 2009

Gorham–Stout syndrome is a rare disease and most often recognized in children and young adults. Chylothorax is a serious complication of Gorham–Stout syndrome. The treatment of either Gorham–Stout syndrome or chylothorax is still a dilemma. We described a 9‐year‐old girl with Gorham–Stout syndrome and chylothorax who was admitted to our hospital because of dyspnea, orthopnea, and bone pain, and treated with interferon alpha‐2b. Pediatr Pulmonol. 2009; 44:613–615. © 2009 Wiley‐Liss, Inc.
Fungal pleural effusion secondary to a rare cause of pancreatic pseudocyst
Authors: Gupta Atul , Marrs Tom , Urquhart Donald , Clarke Simon , Rosenthal Mark , Bush Andrew
Published: May 2009

We report a case of fungal pleural effusion secondary to presumed valproate induced pancreatitis with pseudocyst and stricture formation. A child with dyskinetic cerebral palsy who had been on sodium valproate for several years was transferred for drainage of a left sided pleural effusion. Pleural fluid culture consistently grew Candida glabrata although the patient was treated with broad‐spectrum antibiotic and antifungal therapy. Clinical deterioration ensued with abdominal discomfort, feed intolerance, and re‐accumulation of the effusion. Investigations revealed a large pancreatic pseudocyst compressing the stomach and impairing pancreatic function. Subsequent therapeutic evacuation of pancreatic fluid demonstrated C. glabrata. This case underscores that pleural disease may be secondary to abdominal pathology, and always to consider rare side‐effects of medication in the face of a puzzling clinical picture. Pediatr Pulmonol. 2009; 44:616–618. © 2009 Wiley‐Liss, Inc.
Mucoid Inquilinus limosus in a young adult with cystic fibrosis
Authors: Hayes Don , Murphy Brian S. , Kuhn Robert J. , Anstead Michael I. , Feola David J.
Published: May 2009

Inquilinus limosus is a α‐proteobacterium that has been recently isolate in the airways of cystic fibrosis (CF) patients. We report the isolation of a mucoid strain of I. limosus from the sputum of a 20‐year‐old male patient with CF over 1 year that was associated with the clinical, spirometric, and radiographic decline in a previously healthy patient. Pediatr Pulmonol. 2009; 44:619–621. © 2009 Wiley‐Liss, Inc.
Inhibition of de novo purine synthesis in human prostate cells results in ATP depletion, AMPK activation and induces senescence
Authors: Obajimi Oluwakemi , Keen Judith Clancy , Melera Peter W.
Published: May 2009

BACKGROUND

4‐[2‐(2‐Amino‐4‐oxo‐4,6,7,8‐tetrahydro‐3H‐pyrimidino[5,4,6][1,4]thiazin‐6‐yl)‐(S)‐ethyl]‐2,5‐thienoylamino‐l‐glutamic acid (AG2034), is a classical antifolate shown to be an excellent inhibitor of glycinamide ribonucleotide formyltransferase (GARFT), ultimately inhibiting de novo purine synthesis. We examined some metabolic effects of this drug in prostate cancer cells, LNCaP, versus non‐tumorigenic prostatic epithelial cells, RWPE‐1.

METHODS AND RESULTS

Cells were cultured in medium containing 10 nM 5‐methyl‐tetrahydrofolate supplemented with/without 1.7 µM hypoxanthine/1.5 µM thymidine. Cytotoxicity of AG2034 was determined by clonogenic assays. Total ATP was quantified by reverse‐phase HPLC and [14C]‐glycine incorporation and [3H]‐hypoxanthine conversion into ATP by liquid scintillation counting. Protein expression levels were determined by Western blotting, cell cycle analysis by propidium iodide staining and cell‐senescence by β‐galactosidase staining. AG2034 inhibited LNCaP cell proliferation causing death in the absence of hypoxanthine and cytostasis in its presence. However, RWPE‐1 cells were resistant to AG2034 when hypoxanthine was present. AG2034 elevates AMP/ATP ratios but is unable to activate AMPK in RWPE‐1 when hypoxanthine is present. Drug exposure increased expression levels of p53, p21, p27, and p16 in both cell lines and increased senescence‐associated‐β‐gal staining in LNCaP with/without hypoxanthine, but primarily in its absence in RWPE‐1.

CONCLUSIONS

LNCaP cells primarily depend upon de novo while RWPE‐1 cells largely favor salvage synthesis for maintenance of their ATP pools. With AG2034 treatment, ATP synthesis via hypoxanthine salvage is insufficient to support growth of LNCaP but enough to restore ATP levels and support RWPE‐1 growth. The anti‐proliferative effect of AG2034 involves increasing phosphorylation of AMPK. These results indicate that AG2034 activates p53 and AMPK mediating the induction of signaling pathways leading to senescence. Prostate 69:1206–1221, 2009. © 2009 Wiley‐Liss, Inc.
Tranilast inhibits hormone refractory prostate cancer cell proliferation and suppresses transforming growth factor β1‐associated osteoblastic changes
Authors: Izumi Kouji , Mizokami Atsushi , Li You Qiang , Narimoto Kazutaka , Sugimoto Kazuhiro , Kadono Yoshifumi , Kitagawa Yasuhide , Konaka Hiroyuki , Koh Eitetsu , Keller Evan T. , Namiki Mikio
Published: May 2009

BACKGROUND

Tranilast is a therapeutic agent used in treatment of allergic diseases, although it has been reported to show anti‐tumor effects on some cancer cells. To elucidate the effects of tranilast on prostate cancer, we investigated the mechanisms of its anti‐tumor effect on prostate cancer.

METHODS

The anti‐tumor effects and related mechanisms of tranilast were investigated both in vitro on prostate cancer cell lines and bone‐derived stromal cells, and in vivo on severe combined immunodeficient (SCID) mice. We verified its clinical effect in patients with advanced hormone refractory prostate cancer (HRPC).

RESULTS

Tranilast inhibited the proliferation of LNCaP, LNCaP‐SF, and PC‐3 cells in a dose‐dependent manner and growth of the tumor formed by inoculation of LNCaP‐SF in the dorsal subcutis and in the tibia of castrated SCID mice. Flow cytometry and TUNEL assay revealed induction of cell cycle arrest and apoptosis by tranilast. Tranilast increased expression of proteins involved in induction of cell cycle arrest and apoptosis. Coculture with bone‐derived stromal cells induced proliferation of LNCaP‐SF cells. Tranilast also suppressed secretion of transforming growth factor β1 (TGF‐β1) from bone‐derived stromal cells, which induced their differentiation. Moreover, tranilast inhibited TGF‐β1‐mediated differentiation of bone‐derived stromal cells and LNCaP‐SF cell migration induced by osteopontin. In the clinical investigation, PSA progression was inhibited in 4 of 16 patients with advanced HRPC.

CONCLUSIONS

These observations suggest that tranilast may be a useful therapeutic agent for treatment of HRPC via the direct inhibitory effect on cancer cells and suppression of TGF‐β1‐associated osteoblastic changes in bone metastasis. Prostate 69:1222–1234, 2009. © 2009 Wiley‐Liss, Inc.
Structural study of Carcinus maenas hemocyanin by native ESI‐MS: Interaction with L‐lactate and divalent cations
Authors: Bruneaux Matthieu , Terrier Peran , Leize Emmanuelle , Mary Jean , Lallier François H. , Zal Franck
Published: May 2009

The interaction of L‐lactate and divalent cations with Carcinus maenas hemocyanin has been probed by electrospray ionization mass spectrometry under conditions preserving noncovalent interactions (native ESI‐MS). C. maenas native hemocyanin in the hemolymph occurs mainly as dodecamers and to a lesser extent as hexamers. A progressive acidification with formic acid after alkaline dissociation resulted in the preferential recruitment of the two lightest subunits into light dodecamers, a molecular complex absent from native hemolymph, in addition to regular dodecamers and hexamers. Addition of L‐lactic acid also induced the recruitment of these subunits, even at alkaline pH. A dodecamer‐specific subunit is needed to enable aggregation over the hexameric state. Experiments with EDTA suggested the existence of different binding sites and association constants for divalent cations within hexameric structures and at the interface between two hexamers. L‐lactic acid specific interaction with the lightest subunits was not inhibited by removal of the divalent cations. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Comparative modeling of human NSF reveals a possible binding mode of GABARAP and GATE‐16
Authors: Thielmann Yvonne , Weiergräber Oliver H. , Ma Peixiang , Schwarten Melanie , Mohrlüder Jeannine , Willbold Dieter
Published: May 2009

Vesicular trafficking is an important homeostatic process in eukaryotic cells which critically relies on membrane fusion. One of the essential components of the universal membrane fusion machinery is NSF (N‐ethylmaleimide‐sensitive factor), a large hexameric ATPase involved in disassembly of SNARE (soluble NSF attachment protein receptor) complexes. To improve our understanding of this sophisticated molecular machine, we have modeled the structure of the NSF hexamer in two alternative assemblies. Our data suggest a mechanistic concept of the operating mode of NSF which helps to explain the functional impact of post‐translational modifications and mutations reported previously. Furthermore, we propose a binding site for the ubiquitin‐like proteins GABARAP and GATE‐16, which is supported by experimental evidence, yielding a complex with favorable surface complementarity. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Antifeedant and sublethal effects of imidacloprid on Asian citrus psyllid, Diaphorina citri
Authors: Boina Dhana Raj , Onagbola Ebenezer O , Salyani Masoud , Stelinski Lukasz L
Published: May 2009

BACKGROUND: Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, transmits the causal bacteria of the devastating citrus disease huanglongbing (HLB). Because of the variation in spatial and temporal uptake and systemic distribution of imidacloprid applied to citrus trees and its degradation over time in citrus trees, ACP adults and nymphs are exposed to concentrations that may not cause immediate mortality but rather sublethal effects. The objective of this laboratory study was to determine the effects of sublethal concentrations of imidacloprid on ACP life stages.

RESULTS: Feeding by ACP adults and nymphs on plants treated daily with a sublethal concentration (0.1 µg mL−1) of imidacloprid significantly decreased adult longevity (8 days), fecundity (33%) and fertility (6%), as well as nymph survival (12%) and developmental rate compared with untreated controls. The magnitude of these negative effects was directly related to exposure duration and concentration. Furthermore, ACP adults that fed on citrus leaves treated systemically with lethal and sublethal concentrations of imidacloprid excreted significantly less honeydew (7–94%) compared with controls in a concentration‐dependent manner suggesting antifeedant activity of imidacloprid.

CONCLUSIONS: Sublethal concentrations of imidacloprid negatively affect development, reproduction, survival and longevity of ACP, which likely contributes to population reductions over time. Also, reduced feeding by ACP adults on plants treated with sublethal concentrations of imidacloprid may potentially decrease the capacity of ACP to successfully acquire and transmit the HLB causal pathogen. Copyright © 2009 Society of Chemical Industry
Current transport modeling of carbon nanotube field effect transistors
Authors: Srivastava Ashok , Marulanda Jose M. , Xu Yao , Sharma Ashwani K.
Published: May 2009

In the present work, analytical modeling equations describing the current transport in carbon nanotube field effect transistors (CNT‐FETs) have been developed from physical electronics, which have strong dependence on the chiral vector and device geometries. These model equations for the CNT‐FETs have been compared with the available experimental data and then used to generate voltage transfer characteristics of basic logic devices based on complementary CNT‐FETs. The voltage transfer characteristics exhibit characteristics similar to the voltage transfer characteristics of standard CMOS logic devices, with a sharp transition near the logic threshold voltage depending on the input conditions. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deposition temperature effects on the characteristics of a‐Si:H deposited by pulsed DC magnetron sputtering
Authors: Cherfi R. , Abdelmoumene A. , Kechouane M. , Rahal A. , Aoucher M. , Mohammed‐Brahim T.
Published: May 2009

In this study, the deposition temperature effects on the properties of hydrogenated amorphous silicon films are reported. The a‐Si:H thin films were deposited by DC magnetron sputtering technique, according to a new protocol of deposition. This last consists of a successively several thin layers deposition separated by a relaxation time between them without stopping plasma (a layer by layer procedure). The a‐Si:H samples elaborated at various deposition temperatures are characterized by a rather high microstructure parameter (ranging between 0.23 and 0.77), indicating that most of hydrogen incorporated into the films is in the form of dihydride bonds. An important increase in the proportion of the polyhydride complexes might favor the porous character of the material and therefore a decrease of its compactness. Otherwise, in the range of deposition temperature 300–400 °C, the microstructural parameters “R2000, R2090” and the dark conductivity “σd” present a particular evolution. Indeed, the earlier studies in our laboratory showed that the layers deposited according to the usual protocol, remain always amorphous until temperatures lower than 600 °C, we thus arrived at temperatures less significant (350 °C) to make a beginning of crystallization. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study on the photodoping effects in La1–xSrx MnO3/SrNby Ti1–yO3 p–n heterojunction
Authors: Liao Leng , Jin Kui‐juan , Lu Hui‐bin , Qiu Jie , Han Peng , Zhang Li‐li
Published: May 2009

The dynamic process of photodoping effect in the heterojunction of La0.9Sr0.1MnO3/SrNb0.01Ti0.99O3 is revealed theoretically. By solving Poisson Equation and time‐dependent carrier continuity equations, the evolutions of the carrier concentrations and the electrical potential are obtained self‐consistently. The calculated photovoltage evolution agrees well with the experimental data. The present results demonstrate that the large variation of carrier concentration mainly locates in the space‐charge region of the oxide heterojunction. It means that the photodoping effect mainly occurs in the space‐charge region of heterojunction. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
2D spectrochemical series of ML6 metal complexes for controlling the ligand field splitting
Authors: Ishii Tomohiko , Tsuboi Shino , Yukinari Shohei , Sakane Genta , Yamashita Masahiro , Breedlove Brian K.
Published: May 2009

We have studied a novel universal spectrochemical series of the six‐coordinated octahedral 3d transition metal complexes that can be used for any combinations of the central metal atoms and the ligand molecules. The spectrochemical series for the six‐coordinated octahedral metal complexes can be well explained by the energy level comparison between the metals and ligands using the DV‐Xα method. The two‐dimensional spectrochemical series can be applied for expecting of the ligand field splitting energy widths of not only the known compounds but also the unknown ones. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Review of multicomponent molecular orbital method for direct treatment of nuclear quantum effect
Authors: Ishimoto Takayoshi , Tachikawa Masanori , Nagashima Umpei
Published: May 2009

We present the methodology and applications of multicomponent molecular orbital (MC_MO) method, which can take into account of the quantum effect of light particles, such as proton and deuteron, directly. We summarize the equations of the MC_MO method at the Hartree–Fock (HF) level and beyond the HF. The methodology of the MC_MO with fragment molecular orbital (FMO) method for large molecular systems is also described. We discuss the development of nuclear basis function based on the GTF, which is used in MC_MO and FMO‐MC_MO calculations. We present the applications of MC_MO and FMO‐MC_MO method for the analysis of geometrical isotope effect and kinetic isotope effect induced by H/D isotope effect. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Molecular orbital study on a mechanism of adhesion between carbides and optical glass with high refractive index
Authors: Fujiwara Yasuhiro , Yoshioka Tomohiko , Tanaka Junzo
Published: May 2009

A mechanism of adhesion between carbide molds and optical glass species with high refractive index in precision molding was elucidated on the basis of DV‐Xα molecular orbital calculations. An interfacial cluster model comprising NbPNaO glass and glassy carbon (GC) was applied in order to examine the changes in the chemical bonds between atoms at the interface and the effect of the substitution of niobium with other transition metals (denoted with; MdI) at the interface. The bond overlap population (BOP) between oxygen atoms at the surface of the glass and carbon atoms at the surface of the GC increases when the surface of the glass approaches the GC, while that between MeIO correspondingly decreases. When introducing oxygen deficiency at the surface of the glass, the BOP of the MeIcarbon bonds against the MeIoxygen increased in the order of Nb<Ti<W, which mostly coincided with the experimentally obtained order of increased probability of occurrence of adhesion between the glass and the GC mold. This supports the validity of the model where adhesion between the glass and the carbide occurs following the reduction of the transition metal in the glass. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
A Gaussian quadrature method for total energy analysis in electronic state calculations
Authors: Fukushima Kimichika
Published: May 2009

This article reports studies by Fukushima and coworkers since 1980 concerning their highly accurate numerical integral method using Gaussian quadratures to evaluate the total energy in electronic state calculations. Gauss‐Legendre and Gauss‐Laguerre quadratures were used for integrals in the finite and infinite regions, respectively. Our previous article showed that, for diatomic molecules such as CO and FeO, elliptic coordinates efficiently achieved high numerical integral accuracy even with a numerical basis set including transition metal atomic orbitals. This article will generalize straightforward details for multiatomic systems with direct integrals in each decomposed elliptic coordinate determined from the nuclear positions of picked‐up atom pairs. Sample calculations were performed for the molecules O3 and H2O. This article will also try to present, in another coordinate, a numerical integral by partially using the Becke's decomposition published in 1988, but without the Becke's fuzzy cell generated by the polynomials of internuclear distance between the pair atoms. Instead, simple nuclear weights comprising exponential functions around nuclei are used. The one‐center integral is performed with a Gaussian quadrature pack in a spherical coordinate, included in the author's original program in around 1980. As for this decomposition into one‐center integrals, sample calculations are carried out for Li2. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Interface science in nanoparticles: An electronic structure view of photon‐in/photon‐out soft‐X‐ray spectroscopy
Authors: Guo Jinghua
Published: May 2009

The ability to control the particle size and morphology of nanoparticles is of crucial importance nowadays both from a fundamental and industrial point of view considering nanostructured 3d metal compounds in the applications of solar photovoltaic, sunlight water splitting and photoelectrochemical cells, chemical and biosensors, etc. In the soft X‐ray region, the question tends to be, what are the electrons doing as they migrated between the atoms? Soft‐X‐ray absorption and emission spectroscopy have basic features that are important to interface science. X‐ray is originating from an electronic transition between a localized core state and a valence state that makes this probe localized to one specific atomic site and gives the method chemical state sensitivity and further, particular symmetry information. The possibility to select the energy of the excitation has created an extra degree of freedom and opens a new field of study by disclosing many new possibilities of soft‐X‐ray resonant inelastic scattering. In this presentation, recent findings regarding X‐ray spectroscopic studies of various nanomaterials are presented. Also, in situ characterization of nanocrystal suspensions demonstrated the way for real‐time studies of nanomaterial growth and chemical reactions. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
High thermoelectric performance of metal‐substituted samples of α‐Fe2O3 and computation of their electronic structures by the DV‐Xα method
Authors: Sugihara Sunao , Suzuki Chikashi , Kameya Ryohei
Published: May 2009

We examined the effects of partial metal substitution on the electronic structure of α‐Fe2O3, with the aim of improving its thermoelectric performance. By powder metallurgy, we prepared samples of (Fe2,Li)2O3 in which part of the Fe was replaced by Li, added in the form of LiF. The electronic structures of the materials were examined by the DV‐Xα method. The lithium‐doped α‐Fe2O3 is a promising thermoelectric semiconductor with a thermoelectric power of −411 μV/K, a resistivity of 3 × 10−4 Ωm, and a thermal conductivity of 4 W/m K. The figure of merit is 0.13 × 10−3 at 870 K, which is superior to that of TiO2‐containing Fe2O3 (0.04 × 10−3). © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Robust fault detection and isolation for parameter‐dependent LFT systems
Authors: Cai Xuejing , Wu Fen
Published: May 2009

In this paper, we consider robust fault detection and isolation (FDI) problems for faulty linear systems with linear fractional transformation (LFT) parameter dependency and propose an observer‐based solution by using multiobjective optimization techniques. To simplify the design process, a general faulty LFT system will be constructed from the standard LFT description by converting actuator/system component faults into sensor faults first. Then a bank of parameter‐dependent FDI filters will be designed to identify each fault. Each FDI filter will generate a residual signal to track an individual fault with minimum error and to suppress the effects of disturbances, time‐varying parameters and other fault signals. The design of LFT parameter‐dependent FDI filters, as a multiobjective optimization problem, will be formulated in terms of linear matrix inequalities (LMIs) and can be solved efficiently. A numerical example is used to demonstrate the proposed fault detection and isolation approach for LFT systems with different parametric structures. Copyright © 2009 John Wiley & Sons, Ltd.
Data mining density of states spectra for crystal structure classification: An inverse problem approach
Authors: Broderick Scott R. , Aourag Hafid , Rajan Krishna
Published: May 2009

The ability to model the density of states has been a long‐standing problem in condensed matter physics. The classical methods that have been used are based on a variety of approaches, ranging from maximum entropy methods to recursion methods involving high dimensional data. In this work, we classify the crystal structure of an alloy based on the electronic structure, the inverse process of first principles calculations which calculate the electronic structure from crystal structure‐based inputs. Here the electronic structure is represented by the density of states, and the classification of crystal structures is achieved through data mining. In addition to classifying alloys by crystal structure, we can classify alloys based on the degree of tetragonality and stoichiometry using solely the density of states spectra. This work seeks to describe the relationship between crystal and electronic structure based on a quantitative interpretation of the density of states, while discussing how capturing the principal contributions of the density of states suggests future work in modeling the density of states using less computationally expensive data mining techniques. © 2009 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 1: 000‐000, 2009
Materials informatics: An emerging technology for materials development
Authors: LeSar Richard
Published: May 2009

The development of new materials has generally been a trial‐and‐error process, which is often long and costly. Computational materials science has progressed to the point that it is being embraced by materials engineering as a key part of the materials development process. Often referred to as integrated computational materials engineering, this new approach links computation with experiment and data to enhance and accelerate materials development. An important component of this integrated approach is materials informatics, in which advanced mining and analysis techniques are applied to experimental and model‐based data as one step of an information‐based process for understanding and exploring materials behavior. Here, we will discuss how, as bioinformatics does in biology, materials informatics offers a new approach to materials research and development. Copyright © 2009 Wiley Periodicals, Inc., A Wiley Company
Overview of the DVB‐SH specifications
Authors: Kelley Philip
Published: May 2009

This article provides an overview of the DVB‐SH specifications, and the context within which they have been developed. The main DVB‐SH configurations are introduced, with explanations of both the technical and frequency planning considerations that drive choices. Regulatory aspects in the European Union and United States of America are summarized. Then specific DVB‐SH issues are being addressed, involving reception conditions and channel characteristics, combining techniques for satellite and terrestrial signals, and synchronization and local content insertion. Some attention is paid to the reuse of DVB link and application layer features. Finally, a couple of likely service introduction scenarios are suggested. It is claimed that DVB‐SH fulfills the initial requirements of extending the present UHF‐based service offer to other frequencies below 3 GHz with a large area coverage, a reduced total network infrastructure cost and an expansion of the offer in terms of number of TV channels or multimedia services. Copyright © 2009 John Wiley & Sons, Ltd.
No evidence that a common pesticide impairs female mate choice in a freshwater amphipod
Authors: Cothran Rickey D. , Greco Raymond L. , Relyea Rick A.
Published: May 2009

Sublethal concentrations of pesticides may drastically alter the evolutionary trajectories of populations by interfering with mating behaviors. We used a median lethal concentration (LC50) experiment to test the sensitivity of three amphipod (Hyalella sp.) classes (females, small males, and large males) to five concentrations [10.4, 1.52, 0.16, 0.05, none detected (ND) μg/L] of the most commonly applied pesticide (malathion) in the United States. We then tested the sensitivity of female mate choice to sublethal concentrations (0.55, 0.38, and 0.05 μg/L) of malathion using a dichotomous choice test. Mortality was relatively high at low concentrations for all three amphipod classes with LC50s ranging from 0.06 μg/L in females to 0.19 μg/L in small males. There was overlap in the 95% CI of these estimates across amphipod classes suggesting no class‐specific differences in sensitivity to malathion. We found no evidence that malathion interferes with female choice in this species, suggesting that mating behavior may not always be a good indicator of sublethal pesticide contamination. © 2009 Wiley Periodicals, Inc. Environ Toxicol 2010.
Cardiac lineage selection: integrating biological complexity into computational models
Authors: Foley Ann
Published: May 2009

The emergence of techniques to study developmental processes using systems biology approaches offers exciting possibilities for the develpmental biologist. In particular cardiac lineage selection may be particularly amenable to these types of studies since the heart is the first fully functional organ to form in vertebrates. However there are many technical obstacles that need to be overcome for these studies to proceed. Here we present a brief overview of cardiomyocyte lineage deterimination and discuss how different aspects of this process either benefit from or present unique challenges for the development of systems biology approaches. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Developmental Biology > Developmental Processes in Health and Disease