bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of reconstruction and acquisition parameters for GRAPPA‐based parallel imaging on the image quality
Authors: Bauer S. , Markl M. , Honal M. , Jung B. A.
Published: March 2011

Parallel imaging based on generalized autocalibrating partially parallel acquisitions is widely used in the clinical routine. To date, no detailed analysis has been presented describing the dependence of the image quality on the reconstruction and acquisition parameters such as the number of autocalibration signal (ACS) lines NACS, the reconstruction kernel size (bx × by), and the undersampling factor R. To evaluate their influence on the performance of generalized autocalibrating partially parallel acquisitions, two phantom data sets acquired with 12‐channel and 32‐channel receive coils and three in vivo measurements were analyzed. Reconstruction parameters were systematically varied between R = 2–4, NACS = 4–64, bx = 1–9, and by = 2–10 to characterize their influence on image quality and noise. A main aspect of the analysis was to optimize the parameter set with respect to the effectively achieved net image acceleration. Selecting the undersampling factor R as small as possible for a given net acceleration yielded the best result in a clear majority of cases. For all data sets and coil geometries, the optimal kernel sizes and number of ACS lines were similar for a chosen undersampling factor R. In summary, the number of ACS lines should not be chosen below NACS = 10–16. A robust choice for the kernel size was bx = 9 and by = 2–4. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Uncertainty quantification in homogenization of heterogeneous microstructures modeled by XFEM
Authors: Hiriyur Badri , Waisman Haim , Deodatis George
Published: March 2011

An extended finite element method (XFEM) coupled with a Monte Carlo approach is proposed to quantify the uncertainty in the homogenized effective elastic properties of multiphase materials. The methodology allows for an arbitrary number, aspect ratio, location and orientation of elliptic inclusions within a matrix, without the need for fine meshes in the vicinity of tightly packed inclusions and especially without the need to remesh for every different generated realization of the microstructure. Moreover, the number of degrees of freedom in the enriched elements is dynamically reallocated for each Monte Carlo sample run based on the given volume fraction. The main advantage of the proposed XFEM‐based methodology is a major reduction in the computational effort in extensive Monte Carlo simulations compared with the standard FEM approach. Monte Carlo and XFEM appear to work extremely efficiently together. The Monte Carlo approach allows for the modeling of the size, aspect ratios, orientations, and spatial distribution of the elliptical inclusions as random variables with any prescribed probability distributions. Numerical results are presented and the uncertainty of the homogenized elastic properties is discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Optimal locations for MR dampers in civil structures using improved Ant Colony algorithm
Authors: Amini F. , Ghaderi P.
Published: March 2011

This paper studies a design problem concerning installation locations for a number of structural magneto‐rheological (MR) dampers. The mechanical characteristic of each MR damper is functional dependent to an input current, which is regulated by a Fuzzy Logic controller. It is demanded that the chosen arrangement of dampers should change the dynamic response of the structure to meet certain constraints expressed in terms of minimization of an objective function. For this purpose, an improved version of Ant Colony Optimization algorithm is presented. The modified algorithm also utilizes additional heuristic data derivable from a pre‐analysis of the structure in the optimization procedure. Further improvements regarding convergence speed of search algorithm are proposed as well, provided numerical examples study the functionality of the algorithm in different cases. With an acceptable probability from a structural designer's point of view, the proposed method finds qualified solutions during a reasonable number of search iterations. Copyright © 2011 John Wiley & Sons, Ltd.
Hematopoietic cell transplantation with autologous cord blood in patients with severe aplastic anemia: An opportunity to revisit the controversy regarding cord blood banking for private use
Authors: Rosenthal Joseph , Woolfrey Ann E. , Pawlowska Anna , Thomas Sandra H. , Appelbaum Frederick , Forman Stephen
Published: March 2011

The controversy surrounding private banking of umbilical cord blood units (CBU), as a safeguard against future malignancy or other life‐threatening conditions, raises many questions in pediatric clinical practice. Recent favorable experiences with autologous transplantation for severe aplastic anemia using privately stored CBU, suggested a possible utility. While private banking is difficult to justify statistically or empirically, there may exist rare cases where autologous transplant of stored umbilical CBU could be beneficial. The reality of privately banked CBU and the possibility for future discovery of additional indications for autologous cord blood transplant, motivated us to re‐examine our attitudes towards private cord blood banking. Pediatr Blood Cancer 2011;56:1009–1012. © 2011 Wiley‐Liss, Inc.
Communication and language challenges experienced by Chinese and South Asian immigrant parents of children with cancer in Canada: Implications for health services delivery
Authors: Gulati Sonia , Watt Lisa , Shaw Nicola , Sung Lillian , Poureslami Iraj M. , Klaassen Robert , Dix David , Klassen Anne F.
Published: March 2011

Background

Language is an important aspect of health literacy and plays a vital role in families' ability to access and use health information and resources. Our study explored the role of communication and language in the healthcare experiences of immigrant parents of children with cancer living in Canada.

Procedure

We used a grounded theory approach. Chinese and South Asian parents of children 6 months post‐diagnosis were recruited from six Canadian pediatric oncology centers. Semi‐structured interviews were conducted in Cantonese, Mandarin, Hindi, Punjabi, Urdu, or English. Questions relevant to communication included: how parents navigated the healthcare system; nature of interpreter services and translated materials; and suggestions about how to improve services. Analysis involved line‐by‐line, focused and theoretical coding, and constant comparison.

Results

Thirty‐one (62%) parents reported no difficulty communicating with healthcare providers in English, while 13 (26%) parents struggled with English, and six (12%) parents could not communicate in English. Communication challenges influenced parents' role in caring for their child and made it difficult to learn complex medical terminology. Interpreting services were sometimes inadequate or not accessible. Parents occasionally missed out on services and resources, reported limited availability of linguistically and culturally appropriate information, and experienced a lack of social integration in the healthcare process.

Conclusion

Language ability played an essential role in parents' healthcare experiences for pragmatic and social purposes. Language challenges can heighten systemic and socio‐cultural barriers to accessing health information and resources. The provision of enhanced culturally and linguistically sensitive services may support immigrant families in their caregiving role. Pediatr Blood Cancer 2012; 58: 572–578. © 2011 Wiley Periodicals, Inc.
Supratentorial ependymoma in children: To observe or to treat following gross total resection?
Authors: Venkatramani Rajkumar , Dhall Girish , Patel Moneil , Grimm John , Hawkins Cynthia , McComb Gordon , Krieger Mark , Wong Kenneth , O'Neil Sharon , Finlay Jonathan L.
Published: March 2011

Background

The standard treatment for ependymoma is surgical resection followed by postoperative irradiation to the local site. The role of radiation therapy in completely resected supratentorial ependymoma has been questioned over the past two decades.

Procedure

Retrospective review of the medical records of all consecutively diagnosed supratentorial ependymoma patients at Children's Hospital Los Angeles between January 1999 and December 2009.

Results

Ten patients (three females) were included. The median age at presentation was 5.6 years (range 1.8–15.6 years). Reviewed histology was anaplastic ependymoma in seven patients and cellular ependymoma in three patients. Gross total resection was achieved in six patients; five were observed and one received chemotherapy. In the four patients who underwent subtotal resection, one was observed, two received local irradiation and one received irradiation and chemotherapy. The median length of follow up was 43 (range 22–81) months. Four relapses were observed; two patients who underwent initial gross total resection. All patients who underwent gross total resection were alive at the time of preparation of this article. The 5‐year progression‐free and overall survival rates were 53 ± 19% and 86 ± 13% respectively.

Conclusions

Radiation therapy was avoided in five patients following gross total resection, four of whom had anaplastic histology. In some children with completely resected supratentorial ependymoma, surgery alone may be an acceptable treatment option. Pediatr Blood Cancer 2012; 58: 380–383. © 2011 Wiley Periodicals, Inc.
Effect of fiber loading and orientation on mechanical and erosion wear behaviors of glass–epoxy composites
Authors: Biswas Sandhyarani , Deo Basu , Patnaik Amar , Satapathy Alok
Published: March 2011

For a composite material, its mechanical behavior and surface damage by solid particle erosion depend on many factors. One of the most important factors is the fiber content. Similarly, these properties are also greatly affected by the fiber orientation. In this work, a series of experiments were carried out to investigate the influence of fiber loading and fiber orientation on mechanical and erosion behavior of glass fiber‐reinforced epoxy composites. The composites were fabricated with three different fiber loadings (20, 30, and 40 wt%) and at four different fiber orientations (15°, 30°, 45°, and 60°). The conclusions drawn on the basis of the experimental findings are discussed, and composite with 30° fiber orientation shows better microhardness compared with other fiber orientations irrespective of fiber loading. Similar observations are also noticed for other mechanical properties of the composites, such as tensile strength, flexural strength, interlaminar shear strength, impact strength, etc. Finally, the morphology of eroded surfaces is examined using scanning electron microscopy (SEM), and possible erosion mechanisms are identified. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Alternating copolymers incorporating cyclopenta[2,1‐b:3,4‐b′]dithiophene unit and organic dyes for photovoltaic applications
Authors: Cheng Yen‐Ju , Hung Lung‐Chang , Cao Fong‐Yi , Kao Wei‐Shun , Chang Chih‐Yu , Hsu Chain‐Shu
Published: March 2011

We have synthesized six p‐type copolymers, CPDT‐co‐TPADCN, CPDT‐co‐TPADTA, CPDT‐co‐TPATCN, CPDT‐co‐DFADCN, CPDT‐co‐DFADTA, and CPDT‐co‐DFATCN, consisting of a cyclopenta[2,1‐b:3,4‐b′]dithiophene (CPDT) unit and an organic dye in an alternating arrangement. Triphenylamine (TPA) or difluorenylphenyl amine (DFA) units serve as the electron donors, whereas dicyanovinyl (DCN), 1,3‐diethyl‐2‐thiobarbituric acid, or tricyanovinyl (TCN) units act as the electron acceptors in the dyes. The target polymers were prepared via Stille coupling, followed by postfunctionalization to introduce the electron acceptors to the side chains. Because of the strongest withdrawing ability of TCN acceptor to induce efficient intramolecular charge transfer, CPDT‐co‐TPATCN and CPDT‐co‐DFATCN exhibit the broader absorption spectra covering from 400 to 900 nm and the narrower optical band gaps of 1.34 eV. However, the CPDT‐co‐TPATCN:PC71BM and CPDT‐co‐DFATCN:PC71BM based solar cells showed the power conversion efficiencies (PCEs) of 0.22 and 0.31%, respectively, due to the inefficient exciton dissociation. The DFA‐based polymers possess deeper‐lying HOMO energy levels than the TPA‐based polymer analogues, leading to the higher Voc values and better efficiencies. The device based on CPDT‐co‐DFADTA:PC71BM blend achieved the best PCE of 1.38% with a Voc of 0.7 V, a Jsc of 4.57 mA/cm2, and a fill factor of 0.43. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis, two‐photon absorption, and optical power limiting of new linear and hyperbranched conjugated polyynes based on bithiazole and triphenylamine
Authors: Jiang Yihua , Wang Yaochuan , Yang Jiabao , Hua Jianli , Wang Bing , Qian Shiqiong , Tian He
Published: March 2011

Two new linear and hyperbranched conjugated polymers P1 and P2 have been synthesized by Sonogashira coupling reaction, in which the main chain consists of bithiazole moieties as electron acceptors and triphenylamino groups as donors. The conjugated polymers were characterized by TGA, UV–vis absorption, fluorescence emission, electrochemical cyclic voltammetry, and two‐photon absorption measurements. They exhibited excellent solubility in organic solvents and high thermal stability (5% of weight loss at 299 °C). The two‐photon absorption cross sections (σ) measured by the open aperture Z‐scan technique using 140 femtosecond (fs) pulse were determined to be 1014 and 552 GM per repeating unit for P1 and P2, respectively. This result shows that the σ of linear conjugated P1 is higher than that of hyperbranched P2, indicating that the linear polymer offers better intramolecular charge transfer ability. In THF, P1 and P2 exhibit intense frequency up‐converted fluorescence under the excitation of 140 fs pulses at 800 nm with the peaks located at 580 and 548 nm, respectively. Meanwhile, the optical limiting behaviors for the polymers were studied by using a focused 800 nm laser beam of 140 fs duration. It was found that these polymers also exhibit good optical‐limiting properties and make them potential candidates for optical limiters in the photonic fields. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Separation of ethylene‐propylene copolymers and ethylene‐propylene‐diene terpolymers using high‐temperature interactive liquid chromatography
Authors: Chitta Rajesh , Macko Tibor , Brüll Robert , Van Doremaele Gerard , Heinz Lars‐Christian
Published: March 2011

Ethylene‐propylene‐diene terpolymers (EPDM) are generally amorphous and, therefore, do not crystallize from solution. Consequently, fractionation techniques based on crystallization, such as crystallization analysis fractionation or temperature rising elution fractionation, cannot be used to analyze their chemical composition distribution. Moreover, no suitable chromatographic system was known, which would enable to separate them according to their chemical composition. In this study, two different sorbent/solvent systems are tested with regard to the capability to separate EPDM‐terpolymers and ethylene‐propylene (EP)‐copolymers according to chemical composition. While porous graphite/1‐decanol system is selective towards ethylene and ethylidene‐2‐norbornene, carbon coated zirconia/2‐ethyl‐1‐hexanol is preferentially selective towards ethylene. Consequently, the earlier system enables to separate both EP copolymers and EPDM according to the chemical composition and the latter mainly according to the ethylene content. The results prove that the chromatographic separation in both sorbent/solvent systems is not influenced by molar mass of a sample or by its long chain branching. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and photovoltaic properties of functional dendritic oligothiophenes
Authors: Zhang Weifeng , Ng Ging Meng , Tam Hoi Lam , Wong Man Shing , Zhu Furong
Published: March 2011

Novel p‐type and low bandgap functional dendritic oligothiophenes bearing hole‐transporting carbazole as peripheral substituents and an electron‐withdrawing dicyanovinyl core group, namely, DCT(n)‐DCN, where n = 1 or 2 for solution‐processable photovoltaic (PV) applications have been synthesized. With electron‐donating carbazole surface‐functionalized moieties conjugated with dicyanovinyl core group, the optical bandgap of these functional dendritic oligothiophene thin‐films greatly reduces to 1.74 eV with a strong spectral broadening and a high ionization potential at ∼5.5 eV as determined by UV photoelectron spectroscopy. The bulk heterojunction PV cells fabricated from these dendrimers blended with PC71BM as an acceptor showed a power conversion efficiency up to 1.64% with an open circuit voltage of (Voc) = 0.93 V in the annealed device. We have demonstrated that the desirable molecular and PV properties of dendritic oligothiophenes can be obtained/tuned by the incorporation of functional group(s) onto peripheral of the dendron and into the core. In addition, these functional dendritic oligothiophenes show superior functional properties even at low dendritic generation as compared to the unsubstituted higher generation dendritic oligothiophenes as a p‐type, low‐bandgap semiconductor for solution‐processable bulk heterojunction PV cells. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Magnetic‐targeted pH‐responsive drug delivery system via layer‐by‐layer self‐assembly of polyelectrolytes onto drug‐containing emulsion droplets and its controlled release
Authors: Mu Bin , Liu Peng , Du Pengcheng , Dong Yun , Lu Chunyin
Published: March 2011

Novel magnetic‐targeted pH‐responsive drug delivery system have been designed by the layer‐by‐layer self‐ assembly of the polyelectrolytes (oligochitosan as the polycation and sodium alginate as the polyanion) via the electrostatic interaction with the oil‐in‐water type hybrid emulsion droplets containing the superparamagnetic ferroferric oxide nanoparticles and drug molecules [dipyridamole (DIP)] as cores. Here the drug molecules were directly encapsulated into the interior of droplets without etching the templates and refilling with the desired guest molecules. The drug‐delivery system showed high encapsulation efficiency of drugs and drug‐loading capacity. The cumulative release ratio of dipyridamole from the oligochitosan/sodium alginate multilayer‐encapsulated magnetic hybrid emulsion droplets (DIP/Fe3O4‐OA/OA)@(OCS/SAL)4 was up to almost 100% after 31 h at pH 1.8. However, the cumulative release ratio was only 3.3% at pH 7.4 even after 48 h. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
The psychological impact of a cancer diagnosed during pregnancy: determinants of long‐term distress
Authors: Henry Melissa , Huang Lina N. , Sproule Barbara J. , Cardonick Elyce H.
Published: March 2011

Background: Cancer occurs during one in 1000–5000 of the approximately 6 million yearly US pregnancies identified by the American Pregnancy Association. Although a newly diagnosed cancer is associated with substantial distress, little is known about cancer's emotional impact on women when diagnosed during pregnancy, and no studies have been conducted on the subject.

Objective: The Cancer and Pregnancy Registry was developed by Elyce H. Cardonick MD, specialist in Maternal and Fetal Medicine and Associate Professor of Obstetrics and Gynecology at Robert Wood Johnson Medical School, to examine the consequences of maternal cancer diagnosis and treatment during pregnancy on maternal, fetal, and neonatal outcomes, including the impact of in utero exposure to chemotherapy.

Methods: Participants were asked to complete questionnaires, including measures of psychological distress, permitting the examination of variables associated with long‐term psychological distress in women following a cancer diagnosis in pregnancy.

Results: Seventy‐four women completed the Brief Symptom Inventory‐18 and Impact of Event Scale on average 3.8 years (SD 2.5) following their cancer diagnosis. Potential variables related to distress included information on: sociodemographics, disease, pregnancy, birth, cancer treatment, and health status. Multiple regression analyses revealed that women were at higher risk of long‐term distress if they had not received fertility assistance, had been advised to terminate the pregnancy, had had a preterm baby, had had a cesarean delivery, had not produced sufficient milk to breastfeed, had been experiencing a recurrence, and/or had undergone surgery post‐pregnancy.

Conclusion: Results are discussed in light of our current knowledge of the normal developmental phase of pregnancy and motherhood. Copyright © 2011 John Wiley & Sons, Ltd.
Vascular proteomics and the discovery process of clinical biomarkers: The case of TWEAK
Authors: Blanco‐Colio Luis M. , Martín‐Ventura Jose L. , Carrero Juan J. , Yilmaz Mahmut I. , Moreno Juan A. , Gómez‐Guerrero Carmen , Ortiz Alberto , Egido Jesús
Published: March 2011

In the last years, big efforts are devoted to the search of novel biomarkers. Proteomic approaches in healthy and pathological samples may help us to discern differential protein expression patterns. These identified proteins include potential culprits in pathological pathways and/or clinical biomarkers to identify individuals at risk. However, extensively validation must be carried out before their implementation into the clinical practice. Biomarkers need to discriminate between health and disease, detect preclinical disease stages, have impact on survival prediction, and add predictive value beyond traditional risk factors and global risk algorithms. Now, we summarize the data of soluble tumor necrosis factor‐like weak inducer of apoptosis (sTWEAK), a new cardiovascular biomarker identified by proteomic analysis. Decreased sTWEAK concentrations have been shown in patients with carotid atherosclerosis, coronary artery disease, congestive heart failure, peripheral artery disease, or chronic kidney disease (CKD). sTWEAK predicted adverse outcomes in patients with heart failure, myocardial infarction, and CKD. Finally, different drug regimens were able to modify sTWEAK plasma levels in patients with CKD. Although sTWEAK seems so far to fulfill the requisites in the development of a new biomarker, more large‐scale studies are warranted to consolidate its usefulness.
Proteomic analysis of urinary upper gastrointestinal cancer markers
Authors: Husi Holger , Stephens Nathan , Cronshaw Andrew , MacDonald Alisdair , Gallagher Iain , Greig Carolyn , Fearon Kenneth C. H. , Ross James A.
Published: March 2011

Purpose: We have investigated the use of human urine as a non‐invasive medium to screen for molecular biomarkers of carcinomas of the upper gastrointestinal (uGI) tract using SELDI‐TOF‐MS.

Experimental design: A total of 120 urine specimens from 60 control and 60 uGI cancer patients were analysed to establish a potential biomarker fingerprint for the weak cation exchanger CM10 chip surface, which was validated by blind testing using a further 59 samples from 33 control and 26 uGI cancer patients.

Results: Using Biomarker Pattern software, we established a model with a sensitivity of 98% and specificity of 95% for the learning sample set, and a sensitivity of 96% and specificity of 72% for the validation data set. Model variable importance included six peptides with m/z of 10 230, 10 436, 10 574, 10 311, 10 467, and 1 0118 of which the 10 230 molecular species was the main decider (sensitivity 86% and specificity 80%). Initial protein database searching identified 10 230 as S100‐A6, 10 436 as S100‐P, 10 467 as S100‐A9, and 10 574 as S100‐A12 of which S100‐A6 and S100‐A9 were confirmed by Western blotting.

Conclusions and clinical relevance: We have demonstrated that SELDI‐TOF‐MS as a screening tool is a rapid and valid methodology in the search for urinary cancer biomarkers, and is potentially useful in defining and consolidating biomarker patterns for uGI cancer screening.
Intercalation of the herbicide atrazine in layered double hydroxides for controlled‐release applications
Authors: Touloupakis Eleftherios , Margelou Asimina , Ghanotakis Demetrios F
Published: March 2011

BACKGROUND: The herbicide atrazine was intercalated in the interlayer region of Mg/Al layered double hydroxides in order to produce a nanohybrid that could be used in controlled‐release applications.

RESULTS: The hydrophobic herbicide was incorporated in artificial membranes formed in the interlayer of the inorganic host by using palmitic acid. The synthetic nanohybrid material was characterised by various techniques, and release studies were carried out. In addition, the photosynthetic alga Chlamydomonas reinhardtii Dang. was treated with the atrazine‐containing nanohybrid, which exerted an herbicidal efficacy similar to that of the free herbicide.

CONCLUSION: The herbicide containing nanohybrid could enable a controlled release of the herbicide. In addition, the herbicide would be delivered close to its site of uptake, enhancing efficiency and reducing the required doses. Copyright © 2011 Society of Chemical Industry
In vitro and in vivo antifungal activity of synthetic pure isothiocyanates against Sclerotinia sclerotiorum
Authors: Kurt Şener , Güneş Ufuk , Soylu Emine M
Published: March 2011

BACKGROUND: Isothiocyanates (ITCs) released by the enzymatic hydrolysis of glucosinolates in the Brassicaceae are potentially useful for controlling fungal pathogens. In vitro activity of pure ITCs against Sclerotinia sclerotiorum (Lib.) de Bary was studied by adding them to glass filters in petri dishes and dissolving them in the growing media.

RESULTS: Methyl, allyl and benzyl ITCs were the most fungitoxic of the compounds in bioassays with S. sclerotiorum isolate Ss31. In the volatile phase, mycelial growth was completely inhibited by these three compounds. Aromatic ITCs were less toxic in the petri dishes but were more toxic than aliphatic ITCs when dissolved in the agar. Benzyl ITC exhibited the highest inhibitory effect on sclerotial germination, with an EC50 value of 75.1 µmol L−1. Butyl and benzyl ITCs reduced apothecial production of S. sclerotiorum by 92.5% at the highest concentration. In in vivo assay, only allyl and 2‐phenylethyl ITCs reduced disease incidence (by 76.7 and 70% respectively) at low concentrations.

CONCLUSION: Sclerotinia sclerotiorum in the soil might be suppressed by the higher concentrations of allyl and benzyl ITCs released from decomposition of Brassica juncea, B. carinata, B. nigra and Sinapis spp. Copyright © 2011 Society of Chemical Industry
Viscosity Estimations of Multi‐Component Slags
Authors: Shu Qifeng , Wang Zhen , Chou Kuochih
Published: March 2011

A model for viscosity estimation of molten aluminosilicate slag, which was developed in our previous study, was extended to estimate viscosity of multi‐component slag containing alkali oxide and calcium fluoride in this study. The charge compensations of alkali oxides for Al tetrahedral ions are explicitly taken into account in the equations. The effect of calcium fluoride on the viscosity of slag was modeled by considering Ca‐2F species and no network‐breaking effect of CaF2 were considered. The present model was applied to estimate the viscosity of slags within Al2O3‐CaO‐FeO‐MgO‐SiO2‐CaF2‐Na2O‐K2O system. A good agreement with a mean deviation of ∼20% was achieved by comparison between estimated and measured values.
The Controlled Generation of Functional Basal Forebrain Cholinergic Neurons from Human Embryonic Stem Cells
Authors: Bissonnette Christopher J. , Lyass Ljuba , Bhattacharyya Bula J. , Belmadani Abdelhak , Miller Richard J. , Kessler John A.
Published: March 2011

An early substantial loss of basal forebrain cholinergic neurons (BFCN) is a constant feature of Alzheimer's disease and is associated with deficits in spatial learning and memory. The ability to selectively control the differentiation of human embryonic stem cells (hESCs) into BFCN would be a significant step toward a cell replacement therapy. We demonstrate here a method for the derivation of a predominantly pure population of BFCN from hESC cells using diffusible ligands present in the forebrain at developmentally relevant time periods. Overexpression of two relevant human transcription factors in hESC-derived neural progenitors also generates BFCN. These neurons express only those markers characteristic of BFCN, generate action potentials, and form functional cholinergic synapses in murine hippocampal slice cultures. siRNA-mediated knockdown of the transcription factors blocks BFCN generation by the diffusible ligands, clearly demonstrating the factors both necessary and sufficient for the controlled derivation of this neuronal population. The ability to selectively control the differentiation of hESCs into BFCN is a significant step both for understanding mechanisms regulating BFCN lineage commitment and for the development of both cell transplant-mediated therapeutic interventions for Alzheimer's disease and high-throughput screening for agents that promote BFCN survival.
Effects of cypermethrin on Allium cepa
Authors: Çavuşoğlu Kültiğin , Kaya Arzu , Yilmaz Fadime , Yalçin Emine
Published: March 2011

In this study, toxic effects of the cypermethrin in Allium cepa L. cells were investigated. For this aim, we investigated the changes in pigment contents, antioxidant enzymes, mitotic index and chromosomal abnormalities as indicators of toxicity. The seeds were treated with different doses (1.5, 3.0, 6.0 ppm) of cypermethrin for 72 h. The result showed that there was a significant alteration in the tested parameters depending on treatment dose in the seeds exposed to cypermethrin when compared to the control group. Cypermethrin exposure significantly reduced the carotenoid, chlorophyll a and b pigments in all treatment groups. The activity of superoxide dismutase showed a concentration‐time dependent increase and the maximum increase was observed on day 15 of treatment at 6.0 ppm cypermethrin exposure. The activity of catalase increased gradually with increasing cypermethrin concentration, but a soft decrease in CAT activity was decreased after 15 days of 1.5 ppm and 3.0 ppm cypermethrin treatment. In the roots treated with 1.5, 3.0, and 6.0 ppm cypermethrin, the level of malondialdehyde was about 1.8, 2.4, and 3.4 times higher than the control group, respectively. It was also found that cypermethrin has a mitodepressive action on mitosis, and the MI was decreased depending on the dose of cyprmethrin. All of the concentrations of cypermethrin induced chromosomal abnormalities and the most common abnormality observed in the present study was chromosome bridges. © 2011 Wiley Periodicals, Inc. Environ Toxicol 2012.
Transdermal nitroglycerin in patients with severe pre‐eclampsia with placental insufficiency: effect on uterine, umbilical and fetal middle cerebral artery resistance indices
Authors: Trapani A. , Gonçalves L. F. , Pires M. M. de S.
Published: March 2011

Objectives

To evaluate the effect of transdermal nitroglycerin on Doppler velocity waveforms of the uterine, umbilical and fetal middle cerebral arteries in patients with severe pre‐eclampsia.

Methods

This was a prospective study of 30 singleton pregnancies (gestational age range: 24–31 weeks) with severe pre‐eclampsia and abnormal uterine and umbilical artery Doppler waveforms. We compared maternal blood pressure as well as the resistance index (RI) and the pulsatility index (PI) of the uterine, umbilical and fetal middle cerebral arteries before and after application of a transdermal nitroglycerin patch (average dose 0.4 mg/h) for a period of 3 days. Intra‐day comparisons before and after administration of nitroglycerin and a comparison between days 0 (no patch) and 3 after administration of the first dose of nitroglycerin were performed using ANOVA for paired samples.

Results

A significant decrease in the PI and RI of the uterine (25.3 ± 4.9% and 21.2 ± 6.2%, respectively, P < 0.001) and umbilical (23.1 ± 6.9% and 19.7 ± 6.1%, respectively, P < 0.001) arteries was noted when comparing the first day without medication against the third day with the patch. No significant change in the PI and RI of the middle cerebral artery was observed. The mean arterial blood pressure decreased from 119.5 ± 4.5 mmHg to 114.8 ± 4.4 mmHg (P < 0.05).

Conclusion

The use of transdermal nitroglycerin in patients with severe pre‐eclampsia is associated with a significant reduction in the RI and PI of the uterine and umbilical arteries, as well as of maternal blood pressure. Transdermal nitroglycerin does not affect the RI and PI of the fetal middle cerebral artery. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Visual attention
Authors: Evans Karla K. , Horowitz Todd S. , Howe Piers , Pedersini Roccardo , Reijnen Ester , Pinto Yair , Kuzmova Yoana , Wolfe Jeremy M.
Published: March 2011

A typical visual scene we encounter in everyday life is complex and filled with a huge amount of perceptual information. The term, ‘visual attention’ describes a set of mechanisms that limit some processing to a subset of incoming stimuli. Attentional mechanisms shape what we see and what we can act upon. They allow for concurrent selection of some (preferably, relevant) information and inhibition of other information. This selection permits the reduction of complexity and informational overload. Selection can be determined both by the ‘bottom‐up’ saliency of information from the environment and by the ‘top‐down’ state and goals of the perceiver. Attentional effects can take the form of modulating or enhancing the selected information. A central role for selective attention is to enable the ‘binding’ of selected information into unified and coherent representations of objects in the outside world. In the overview on visual attention presented here we review the mechanisms and consequences of selection and inhibition over space and time. We examine theoretical, behavioral and neurophysiologic work done on visual attention. We also discuss the relations between attention and other cognitive processes such as automaticity and awareness.WIREs Cogni Sci2011 2 503–514 DOI: 10.1002/wcs.127

This article is categorized under:

Psychology > Attention
Strukturanalytische Untersuchungen P‐substituierter 1,3,2‐Diazaphospholidine
Authors: Puntigam Oliver , Hajdók Imre , Nieger Martin , Niemeyer Mark , Strobel Sabine , Gudat Dietrich
Published: March 2011

2‐Diphenylphosphanyl‐1,3,2‐diazaphospholidines were prepared via metathesis from 2‐chloro‐1,3,2‐diazaphospholidines and LiPPh2. For some of the products, symmetrisation to tetraphenyldiphosphane and 2,2′‐bis‐1,3,2‐diazaphospholidinyls was observed. Most of the derivatives were characterised by single‐crystal X‐ray diffraction, which showed that all compounds studied feature elongated exocyclic P–Cl or P–P‐bonds, respectively. The extent of this bond lengthening is in the P‐phosphanyl‐substituted species similar and in the P‐chloro‐derivatives less pronounced than in corresponding CC‐unsaturated 1,3,2‐diazaphospholenes. Structure correlation involving comparison of exocyclic P–X and endocyclic P–N distances suggests that n(N)/σ*(P–X) hyperconjugation contributes strongly to the bond lengthening and induces a perceptible weakening of the P–P bonds in 2‐diphenylphosphanyl‐1,3,2‐diazaphospholidines, which should render these compounds interesting substrates for P–P bond activation reactions.
Development and Evaluation of a Decision Aid for BRCA Carriers with Breast Cancer
Authors: Culver Julie O. , MacDonald Deborah J. , Thornton Andrea A. , Sand Sharon R. , Grant Marcia , Bowen Deborah J. , Burke Harry , Garcia Nellie , Metcalfe Kelly A. , Weitzel Jeffrey N.
Published: March 2011

BRCA+ breast cancer patients face high risk for a second breast cancer and ovarian cancer. Helping these women decide among risk‐reducing options requires effectively conveying complex, emotionally‐laden, information. To support their decision‐making needs, we developed a web‐based decision aid (DA) as an adjunct to genetic counseling. Phase 1 used focus groups to determine decision‐making needs. These findings and the Ottawa Decision Support Framework guided the DA development. Phase 2 involved nine focus groups of four stakeholder types (BRCA+ breast cancer patients, breast cancer advocates, and genetics and oncology professionals) to evaluate the DA's decision‐making utility, information content, visual display, and implementation. Overall, feedback was very favorable about the DA, especially a values and preferences ranking‐exercise and an output page displaying personalized responses. Stakeholders were divided as to whether the DA should be offered at‐home versus only in a clinical setting. This well‐received DA will be further tested to determine accessibility and effectiveness.
Effect of dioxin exposure on several indices of blood redox status in lactating buffalo cows
Authors: Spagnuolo Maria Stefania , Sarubbi Fiorella , Rossetti Cristina , Grazioli Giuseppe , Di Meo Giulia Pia , Iannuzzi Leopoldo
Published: March 2011

Dioxins are lipophilic compounds with a small molecular weight and are highly persistent, bioaccumulative and toxic. Dioxin detoxification is associated with an increased production of reactive oxygen species (ROS). In physiological conditions the body is protected against ROS and their toxic products by a wide range of antioxidant systems. We hypothesize that the imbalance between ROS production, associated with dioxin exposure, and the antioxidant defence capacity, may lead to oxidative stress, with consequent increased consumption of antioxidants and accumulation of toxic compounds in blood and tissues. The objective of this study was to evaluate the effect of exposure to dioxins on the plasma redox status of lactating buffalo cows. To this aim, the major liposoluble (retinol and α-tocopherol) and water-soluble (ascorbate) antioxidants, the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, the total antioxidant capacity (TAC), as well as specific protein oxidation markers (protein bound carbonyls and nitro-tyrosine) and lipid oxidation markers (hydroperoxides), were chosen as indices of blood redox status. The concentration of antioxidants, protein-bound carbonyls (PC), nitro-tyrosine (N-Tyr), and hydroperoxides (LPO), the SOD and GPx activity, and the TAC were measured in plasma samples obtained from buffalo cows exposed to environmental levels of dioxins higher (n=21, group A) or lower (n=29; group B) than those permitted. Plasma titres of antioxidants, as measured by HPLC, and the total antioxidant capacity, as measured by trolox equivalents capacity, were higher in group B than in A. Similarly, SOD and GPx activities were higher in group B than in A. Conversely, plasma levels of PC, N-Tyr and LPO, as measured by ELISA, were higher in group A than in B. Our results suggest that exposure to dioxins impairs the plasma antioxidant defence system of lactating buffalo cows, and that metabolic processes associated with dioxin detoxification might induce or enhance oxidation of protein and lipids. This adverse effect on blood redox status might have negative implications for animal health and reproduction, and might compromise animal welfare.
Constructing ageing and age identities: a case study of newspaper discourses
Authors: FEALY GERARD , McNAMARA MARTIN , TREACY MARGARET PEARL , LYONS IMOGEN
Published: March 2011

Public discourses concerning older people are available in a variety of texts, including popular media, and these discourses position older people with particular age identities. This study examined discursive formations of ageing and age identities in print media in Ireland. Constituting a single media event, newspaper texts concerned with revised welfare provision for older people were subjected to critical discourse analysis and revealed particular ways of naming and referencing older people and distinct constructions of ageing and age identities. The use of nouns and phrases to name and reference older people positioned them as a distinct demographic group and a latent ageism was discernible in texts that deployed collective names like ‘grannies and grandads’ and ‘little old ladies’. Five distinct identity types were available in the texts, variously constructing older people as ‘victims’; ‘frail, infirm and vulnerable’; ‘radicalised citizens’; ‘deserving old’ and ‘undeserving old’. The discourses made available subject positions that collectively produced identities of implied dependency and otherness, thereby placing older people outside mainstream Irish society. The proposition that older people might be healthy, self-reliant and capable of autonomous living was largely absent in the discourses. Newspaper discourses betray taken-for-granted assumptions and reveal dominant social constructions of ageing and age identity that have consequences for older people's behaviour and for the way that society behaves towards them.
Comparison of EMG-based and Accelerometer-based Speed Estimation Methods in Pedestrian Dead Reckoning
Authors: Chen Wei , Chen Ruizhi , Chen Xiang , Zhang Xu , Chen Yuwei , Wang Jianyu , Fu Zhongqian
Published: March 2011

In low-cost self-contained pedestrian navigation systems, traditional Pedestrian Dead Reckoning (PDR) solutions utilize accelerometers to derive the speed as well as the distance travelled, and obtain the walking heading from magnetic compasses or gyros. However, these measurements are sensitive to instrument errors and disturbances from ambient environment. To be totally different from these signals in nature, the electromyography (EMG) signal is a typical kind of biomedical signal that measures electrical potentials generated by muscle contractions from the human body. This kind of signal would reflect muscle activities during human locomotion, so that it can not only be used for speed estimation, but also disclose the azimuth information from the contractions of lumbar muscles when changing the direction of walking. Therefore, investigating how to utilize the EMG signal for PDR is interesting and promising. In this paper, a novel EMG-based speed estimation method is presented, including setup of the EMG equipment, pre-processing procedure, stride detection and stride length estimation. Furthermore, this method suggested is compared with the traditional one based on accelerometers by means of several field tests. The results demonstrate that the EMG-based method is effective and its performance in PDR can be comparable to that of the accelerometer-based method.
Personal Robust Navigation in Challenging Applications
Authors: Renaudin Valérie , Gilliéron Pierre-Yves
Published: March 2011

Personal navigation has grown rapidly with the introduction of ubiquitous computing and the new generation of smart phones. Appropriate localisation is nowadays a central element for many applications and mobile services. However the proper estimation of the user's location remains a challenge. This paper presents an innovative concept for accurate and reliable positioning in challenging applications. It consists of three components: an absolute geographical reference, the hybridisation of complementary technologies and specific motion models. Two different applications illustrate this concept: urban displacement of blind people and guidance of firefighters. The validity of the concept is assessed with indoor experimental results. Finally the conclusion gives a prospective view of robust personal navigation.
Airport Surface Movement – Critical Analysis of Navigation System Performance Requirements
Authors: Schuster Wolfgang , Ochieng Washington
Published: March 2011

The CNS/ATM concept envisages reliance on global satellite navigation systems to underpin future air traffic management that is able to cope with the ever-increasing demand for air travel without jeopardising safety and the environment. In order to benefit from GNSS, it is crucial that the navigation performance required of air navigation systems is derived and agreed, based on sound principles. Significant work has been undertaken to date and agreement reached on the navigation requirements for the phases of flight up to Category I (CAT-I) precision approach, and proposals are under discussion for CAT-III precision approach. This paper completes a typical flight profile by addressing airport surface movement, and proposing the requirements based on operational requirements for each airport category, to support operations in zero visibility conditions. The benefits of the approach taken in the derivation of the requirements are discussed relative to the existing navigation requirements.
The Empirical Reconstruction of Columbus' Navigational Log and Track of his 1492–1493 Discovery Voyage
Authors: Peck Douglas T.
Published: March 2011

This study is a brief report of the only re-sailing of Columbus' 1492–1493 Voyage following the data in his log in a scientifically controlled research voyage by a professional and experienced global and ocean navigator. The study is follow-on to the article: “The Controversial Skill of Columbus as a Navigator: An Enduring Historical Enigma,” published in The Journal of Navigation (2009) Vol. 62, 417–4251.
Uncertainty in Personal Navigation Services
Authors: Karimi Hassan A. , Roongpiboonsopit Duangduen , Kasemsuppakorn Piyawan
Published: March 2011

The demand for navigation assistance and advances in several technologies has been paving the way for Personal Navigation Services (PerNavs). As users increasingly rely on PerNavs for navigation assistance, they gain a better understanding of what PerNavs can offer and how they operate. This trend, consequently, will increase the demand for PerNav that can provide high quality solutions. While there have been studies addressing uncertainties associated with selected individual navigation modules, there is a void in the literature addressing the overall uncertainty in PerNavs. In this paper, we discuss uncertainty in PerNavs by analyzing uncertainties associated with each of its modules and how they propagate and impact other modules. A Bayesian network is presented as one possible model to manage (by developers) and communicate (to users) uncertainty in PerNavs.
Where Do People Drive? Navigation System Use by Typical Drivers and Auto Experts
Authors: Lo Victor Ei-Wen , Green Paul A. , Franzblau Alfred
Published: March 2011

To effectively design navigation and travel information systems, car manufacturers need data on how these systems are typically used. In this study, researchers surveyed thirty typical drivers and eleven auto experts to determine previously visited destinations, favourite destinations, and other information. Unexpectedly, subjects predominantly reported they used navigation systems to reach familiar destinations (typical drivers: 61%; auto experts: 89%).Historywas self-reported to be a very common entry method (typical drivers: 30%; auto experts: 24%), which conflicted with data retrieved from navigation systems (both groups: <1%). Based on the history list, common trip purposes includedShoppingand visitingFriends' Houses.
Seasonal pattern and genotype distribution of sapovirus infection in Japan, 2003–2009
Authors: DEY S. K. , PHATHAMMAVONG O. , NGUYEN T. D. , THONGPRACHUM A. , CHAN-IT W. , OKITSU S. , MIZUGUCHI M. , USHIJIMA H.
Published: March 2011

Sapovirus, a member of the family Caliciviridae, is one of the major causative agents of viral gastroenteritis affecting all age groups. A total of 3232 faecal specimens collected from infants and children with gastroenteritis in five different regions of Japan during 2003–2009 were examined for sapovirus by reverse transcription–polymerase chain reaction. Sapoviruses were detected in 131 (4·05%) patients with the peak observed mainly in the cold season (November–March) in Japan during 2003–2009. During the last 6 years, sapovirus GI/1 was the predominant strain in Japan followed by GIV, GII/3, GII/6, GII/2, GII/12 and GI, respectively.
Quantification of Subsurface Damage in a Brittle Insulating Ceramic by Three-Dimensional Focused Ion Beam Tomography
Authors: Payraudeau N. , McGrouther D. , O'Kelly K.U.
Published: March 2011

In this study, we present a fully automated method to investigate and reconstruct the three-dimensional crack structure beneath an indent in a highly insulating material. This work concentrates on issues arising from a long automatic acquisition process, the insulating nature of the specimen, and the introduction of minimal damage to the original cracks resulting from indentation.