bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear Extension of Multiproduct Expansion Schemes and Applications to Rigid Bodies
Authors: Geiser Jürgen
Published: September 2013

In this paper we discuss time integrators for nonlinear differential equations. In recent years, splitting approaches have become an important tool for reducing the computational time needed to solve differential equations. Moreover, nonlinearity is a challenge to splitting schemes, while one has to extend the exp-functions in terms of a nonlinear Magnus expansion. Here we discuss a novel extension of the so-called multiproduct expansion methods, which is used to improve the standard Strang splitting schemes as to their nonlinearity. We present an extension of linear splitting schemes and concentrate on nonlinear systems of differential equations and generalise in this respect the recent MPE method; see (Chin and Geiser, 2011). Some first numerical examples, of rigid body problems, are given as benchmarks.
A Novel Neuron in Kernel Domain
Authors: Khandan Zahra , Sadoghi Yazdi Hadi
Published: September 2013

Kernel-based neural network (KNN) is proposed as a neuron that is applicable in online learning with adaptive parameters. This neuron with adaptive kernel parameter can classify data accurately instead of using a multilayer error backpropagation neural network. The proposed method, whose heart is kernel least-mean-square, can reduce memory requirement with sparsification technique, and the kernel can adaptively spread. Our experiments will reveal that this method is much faster and more accurate than previous online learning algorithms.
2-Hour Postload Serum Glucose Levels and Maternal Blood Pressure as Independent Predictors of Birth Weight in “Appropriate for Gestational Age” Neonates in Healthy Nondiabetic Pregnancies
Authors: Saleh Jumana , Machado Lovina , Razvi Zahra
Published: September 2013

Introduction. Increased neonatal birth weight (NBW), often associated with diabetic pregnancies, is a recognized indicator of childhood obesity and future metabolic risk. Predictors of NBW in healthy non-diabetic pregnancies are not yet established. Here, we investigated the association of maternal parameters of healthy non-diabetic mothers with NBW of their “appropriate-for-gestational age” neonates.Methods. The study involved 36 healthy mother/infant pairs. Examined parameters included NBW, maternal age, first and last trimester (BMI), weight gain, fasting serum lipids and glucose, 2-hour postload glucose levels and blood pressure.Results. Postload-glucose levels were significantly higher in mothers of heavier neonates. ANOVA results indicated that 15% increase in postload-glucose levels corresponded to more than 0.5 Kg increase in NBW in the third tertile. NBW correlated positively with postload glucose levels, and negatively with systolic blood pressure. Regression analysis showed that the main predictors of NBW were postload-glucose levels (B=0.455,P=0.003), followed by systolic blood pressure (B=−0.447,P=0.004), together predicting 31.7% NBW variation.Conclusion. This study highlights that increased maternal postload sugar levels and blood pressure, within the normal range, highly predicts NBW of healthy mothers. These findings may provide focus for early dietary intervention measures to avoid future risks to the mother and baby.
Thin Film CIGS Solar Cells, Photovoltaic Modules, and the Problems of Modeling
Authors: Parisi Antonino , Curcio Luciano , Rocca Vincenzo , Stivala Salvatore , Cino Alfonso C. , Busacca Alessandro C. , Cipriani Giovanni , La Cascia Diego , Di Dio Vincenzo , Miceli Rosario , Ricco Galluzzo Giuseppe
Published: September 2013

Starting from the results regarding a nonvacuum technique to fabricate CIGS thin films for solar cells by means of single-step electrodeposition, we focus on the methodological problems of modeling at cell structure and photovoltaic module levels. As a matter of fact, electrodeposition is known as a practical alternative to costly vacuum-based technologies for semiconductor processing in the photovoltaic device sector, but it can lead to quite different structural and electrical properties. For this reason, a greater effort is required to ensure that the perspectives of the electrical engineer and the material scientist are given an opportunity for a closer comparison and a common language. Derived parameters from ongoing experiments have been used for simulation with the different approaches, in order to develop a set of tools which can be used to put together modeling both at single cell structure and complete module levels.
Adaptive Synchronization of Complex Dynamical Networks Governed by Local Lipschitz Nonlinearlity on Switching Topology
Authors: Liu Bo , Wang Xiaoling , Gao Yanping , Xie Guangming , Su Housheng
Published: September 2013

This paper investigates the adaptive synchronization of complex dynamical networks satisfying the local Lipschitz condition with switching topology. Based on differential inclusion and nonsmooth analysis, it is proved that all nodes can converge to the synchronous state, even though only one node is informed by the synchronous state via introducing decentralized adaptive strategies to the coupling strengths and feedback gains. Finally, some numerical simulations are worked out to illustrate the analytical results.
A Multiobjective Optimization Model in Automotive Supply Chain Networks
Authors: Sadrnia Abdolhossein , Ismail Napsiah , Zulkifli Norzima , Ariffin M. K. A. , Nezamabadi-pour Hossein , Mirabi Hamed
Published: September 2013

In the new decade, green investment decisions are attracting more interest in design supply chains due to the hidden economic benefits and environmental legislative barriers. In this paper, a supply chain network design problem with both economic and environmental concerns is presented. Therefore, a multiobjective optimization model that captures the trade-off between the total logistics cost and CO2emissions is proposed. With regard to the complexity of logistic networks, a new multiobjective swarm intelligence algorithm known as a multiobjective Gravitational search algorithm (MOGSA) has been implemented for solving the proposed mathematical model. To evaluate the effectiveness of the model, a comprehensive set of numerical experiments is explained. The results obtained show that the proposed model can be applied as an effective tool in strategic planning for optimizing cost and CO2emissions in an environmentally friendly automotive supply chain.
Synthesis and Properties of Macrocyclic Butanoic Acid Conjugates as a Promising Delivery Formulation for the Nutrition of Colon
Authors: Cheng Jingui , Li Benpeng , Ma Peipei , Liu Mengying , Wang Zhizhong
Published: September 2013

Butanoic acid plays a significant role in the maintenance of mucosal health and is the preferred energy substrate for the cells in the colon. Here, butanoic acid was selectively conjugated to the secondary hydroxyl group of β‐cyclodextrin through ester bond using sodium hydride as the deprotonation reagent. The preliminary release behaviors of butanoic acid in rat gastrointestinal tract contents were investigated at 37°C within 12 h. In the contents of stomach, the conjugates did seldom release butanoic acid, released butanoic acid only 5.8% in the contents of small intestine, and released butanoic acid significantly up to 38.4% in the contents of colon. These results indicate that the conjugate activation took place site specifically in the rat colonic contents, via the biodegradation by glycosidases and hydrolases in the colon. Therefore, the β‐cyclodextrin conjugates of butanoic acid may be of value as an orally administered colon‐specific formulation for the nutrition of colon.
Osseointegrated Supported Prosthesis and Interdisciplinary Approach for Prosthodontic Rehabilitation of a Young Patient with Ectodermal Dysplasia
Authors: Sadashiva Karthik M. , Shetty N. Sridhar , Hegde Rakshith , Karthik Mallika M.
Published: September 2013

Anhidrotic ectodermal dysplasia is a triad of hypodontia or anodontia, hypotrichosis, and hypohydrosis, associated with other problems that result from the defective development of structures of ectodermal origin (Freire-Maia, Pinheiro (1988)). Early and extensive dental treatment is needed keeping in mind the effect on the craniofacial growth. Due to rapid growth of the jaws, the patients are rehabilitated using removable prostheses (Tarjan et al. (2005)). Hence for a young patient in this case report, the placement of endosseous osseointegrated implants was delayed till adulthood. Finally a definitive fixed tooth-supported and osseointegrated implant supported fixed partial denture therapy was used to rehabilitate the patient satisfactorily after she had completed her growth (Sweeney et al. (2005)). A review of the current literature relevant to several aspects of syndromic hypodontia, patient selection, and implant planning is discussed.
Helicobacter pylori Protein–Specific Antibodies and Risk of Colorectal Cancer
Authors: Epplein Meira , Pawlita Michael , Michel Angelika , Peek Richard M. , Cai Qiuyin , Blot William J.
Published: September 2013

Background: There is biologic plausibility as to why infection with Helicobacter pylori, the leading cause of gastric cancer, may also increase the risk of colorectal cancer, but the epidemiologic findings have been inconsistent. We assessed the association of H. pylori protein–specific infection and colorectal cancer risk in the prospective cohort, the Southern Community Cohort Study.

Methods: Multiplex serology was used to measure antibodies to 15 H. pylori proteins in prediagnostic blood among 188 incident colorectal cancer cases and 370 controls matched by age, race, sex, and blood collection timing. Conditional logistic regression was used to calculate ORs and 95% confidence intervals (CI).

Results: Overall H. pylori prevalence was not associated with colorectal cancer risk (OR, 1.03; 95% CI, 0.59–1.77). However, seropositivity to any of five specific H. pylori proteins (VacA, HP231, HP305, NapA, and HcpC) was associated with a significant 60% to 80% increase in odds of risk. These associations became even stronger when limited to colon cancer risk, particularly for the known H. pylori toxin VacA (OR, 2.24; 95% CI, 1.22–4.11), including a significant, positive dose–response association by VacA antibody levels in quartiles (P < 0.05). Associations with VacA seropositivity were especially strong for early-onset and late-stage cancers.

Conclusions: The findings raise the hypothesis that individuals with high levels of antibodies to specific H. pylori proteins may be at higher risk of colon cancer.

Impact: Further investigation of the H. pylori–colorectal cancer association is warranted to determine the possibility of protein-specific antibody levels as a risk biomarker. Cancer Epidemiol Biomarkers Prev; 22(11); 1964–74. ©2013 AACR.
Efficacy of BET Bromodomain Inhibition in Kras-Mutant Non–Small Cell Lung Cancer
Authors: Shimamura Takeshi , Chen Zhao , Soucheray Margaret , Carretero Julian , Kikuchi Eiki , Tchaicha Jeremy H. , Gao Yandi , Cheng Katherine A. , Cohoon Travis J. , Qi Jun , Akbay Esra , Kimmelman Alec C. , Kung Andrew L. , Bradner James E. , Wong Kwok-Kin
Published: September 2013

Purpose: Amplification of MYC is one of the most common genetic alterations in lung cancer, contributing to a myriad of phenotypes associated with growth, invasion, and drug resistance. Murine genetics has established both the centrality of somatic alterations of Kras in lung cancer, as well as the dependency of mutant Kras tumors on MYC function. Unfortunately, drug-like small-molecule inhibitors of KRAS and MYC have yet to be realized. The recent discovery, in hematologic malignancies, that bromodomain and extra-terminal (BET) bromodomain inhibition impairs MYC expression and MYC transcriptional function established the rationale of targeting KRAS-driven non–small cell lung cancer (NSCLC) with BET inhibition.

Experimental Design: We performed functional assays to evaluate the effects of JQ1 in genetically defined NSCLC cell lines harboring KRAS and/or LKB1 mutations. Furthermore, we evaluated JQ1 in transgenic mouse lung cancer models expressing mutant kras or concurrent mutant kras and lkb1. Effects of bromodomain inhibition on transcriptional pathways were explored and validated by expression analysis.

Results: Although JQ1 is broadly active in NSCLC cells, activity of JQ1 in mutant KRAS NSCLC is abrogated by concurrent alteration or genetic knockdown of LKB1. In sensitive NSCLC models, JQ1 treatment results in the coordinate downregulation of the MYC-dependent transcriptional program. We found that JQ1 treatment produces significant tumor regression in mutant kras mice. As predicted, tumors from mutant kras and lkb1 mice did not respond to JQ1.

Conclusion: Bromodomain inhibition comprises a promising therapeutic strategy for KRAS-mutant NSCLC with wild-type LKB1, via inhibition of MYC function. Clinical studies of BET bromodomain inhibitors in aggressive NSCLC will be actively pursued. Clin Cancer Res; 19(22); 6183–92. ©2013 AACR.
Overcoming IGF1R/IR Resistance through Inhibition of MEK Signaling in Colorectal Cancer Models
Authors: Flanigan Sara A. , Pitts Todd M. , Newton Timothy P. , Kulikowski Gillian N. , Tan Aik Choon , McManus Martine C. , Spreafico Anna , Kachaeva Maria I. , Selby Heather M. , Tentler John J. , Eckhardt S. Gail , Leong Stephen
Published: September 2013

Purpose: Results from clinical trials involving resistance to molecularly targeted therapies have revealed the importance of rational single-agent and combination treatment strategies. In this study, we tested the efficacy of a type 1 insulin-like growth factor receptor (IGF1R)/insulin receptor (IR) tyrosine kinase inhibitor, OSI-906, in combination with a mitogen–activated protein (MAP)–ERK kinase (MEK) 1/2 inhibitor based on evidence that the MAP kinase pathway was upregulated in colorectal cancer cell lines that were resistant to OSI-906.

Experimental Design: The antiproliferative effects of OSI-906 and the MEK 1/2 inhibitor U0126 were analyzed both as single agents and in combination in 13 colorectal cancer cell lines in vitro. Apoptosis, downstream effector proteins, and cell cycle were also assessed. In addition, the efficacy of OSI-906 combined with the MEK 1/2 inhibitor selumetinib (AZD6244, ARRY-142886) was evaluated in vivo using human colorectal cancer xenograft models.

Results: The combination of OSI-906 and U0126 resulted in synergistic effects in 11 of 13 colorectal cancer cell lines tested. This synergy was variably associated with apoptosis or cell-cycle arrest in addition to molecular effects on prosurvival pathways. The synergy was also reflected in the in vivo xenograft studies following treatment with the combination of OSI-906 and selumetinib.

Conclusions: Results from this study demonstrate synergistic antiproliferative effects in response to the combination of OSI-906 with an MEK 1/2 inhibitor in colorectal cancer cell line models both in vitro and in vivo, which supports the rational combination of OSI-906 with an MEK inhibitor in patients with colorectal cancer. Clin Cancer Res; 19(22); 6219–29. ©2013 AACR.
Dual CDK4/CDK6 Inhibition Induces Cell-Cycle Arrest and Senescence in Neuroblastoma
Authors: Rader JulieAnn , Russell Mike R. , Hart Lori S. , Nakazawa Michael S. , Belcastro Lili T. , Martinez Daniel , Li Yimei , Carpenter Erica L. , Attiyeh Edward F. , Diskin Sharon J. , Kim Sunkyu , Parasuraman Sudha , Caponigro Giordano , Schnepp Robert W. , Wood Andrew C. , Pawel Bruce , Cole Kristina A. , Maris John M.
Published: September 2013

Purpose: Neuroblastoma is a pediatric cancer that continues to exact significant morbidity and mortality. Recently, a number of cell-cycle proteins, particularly those within the Cyclin D/CDK4/CDK6/RB network, have been shown to exert oncogenic roles in neuroblastoma, suggesting that their therapeutic exploitation might improve patient outcomes.

Experimental Procedures: We evaluated the effect of dual CDK4/CDK6 inhibition on neuroblastoma viability using LEE011 (Novartis Oncology), a highly specific CDK4/6 inhibitor.

Results: Treatment with LEE011 significantly reduced proliferation in 12 of 17 human neuroblastoma-derived cell lines by inducing cytostasis at nanomolar concentrations (mean IC50 = 307 ± 68 nmol/L in sensitive lines). LEE011 caused cell-cycle arrest and cellular senescence that was attributed to dose-dependent decreases in phosphorylated RB and FOXM1, respectively. In addition, responsiveness of neuroblastoma xenografts to LEE011 translated to the in vivo setting in that there was a direct correlation of in vitro IC50 values with degree of subcutaneous xenograft growth delay. Although our data indicate that neuroblastomas sensitive to LEE011 were more likely to contain genomic amplification of MYCN (P = 0.01), the identification of additional clinically accessible biomarkers is of high importance.

Conclusions: Taken together, our data show that LEE011 is active in a large subset of neuroblastoma cell line and xenograft models, and supports the clinical development of this CDK4/6 inhibitor as a therapy for patients with this disease. Clin Cancer Res; 19(22); 6173–82. ©2013 AACR.
Escalating Regulation of 5T4-Specific IFN-γ+ CD4+ T Cells Distinguishes Colorectal Cancer Patients from Healthy Controls and Provides a Target for In Vivo Therapy
Authors: Scurr Martin , Bloom Anja , Pembroke Tom , Srinivasan Rohit , Brown Clare , Smart Kathryn , Bridgeman Hayley , Davies Mike , Hargest Rachel , Phillips Simon , Christian Adam , Hockey Tom , Gallimore Awen , Godkin Andrew
Published: September 2013

The relationship between the adaptive CD4+ T-cell response and human cancer is unclear. The oncofetal antigen 5T4 is expressed in many human carcinomas, including colorectal cancer cells, but has limited expression on normal tissues. We previously identified anti-5T4 CD4+ T cells in a proportion of patients with colorectal cancer, and we extended this study to examine whether the quality or quantity of the T-cell response reflects tumor stage. An overlapping peptide library spanning 5T4 was used as a target to enumerate cognate IFN-γ+ CD4+ T cells [measured as spot-forming cells (SFC)/105 cultured T cells] in peripheral blood–derived lymphocytes following a 14-day in vitro culture period comparing patients preoperatively (n = 27) to healthy controls (n = 17). Robust 5T4-specific T-cell responses were present in 100% of healthy donors. There was a steady loss of T-cell responses with advancing tumors with a significant negative correlation from stage I to III (P = 0.008). The predictability of the decline meant <200 SFC/105 were only found in subjects with stage III colorectal cancer. The mechanism of loss of T-cell response is independent of HLA-DR type or patient age but does correspond to increases in Foxp3+ regulatory T cells (Treg). Using low-dose cyclophosphamide to reduce the proportion of Tregs in vivo resulted in increased anti-5T4 T-cell responses in patients with colorectal cancer. The selective loss of 5T4-specific IFN-γ+ CD4+ T-cell responses implies a link between tumor stage and antitumor Th1 effector function; depleting Tregs can enhance such responses. Cancer Immunol Res; 1(6); 416–25. ©2013 AACR.
Validity of Discharge Diagnoses in the Surveillance of Stroke
Authors: Ramalle-Gomara Enrique , Ruiz Elena , Serrano Marta , Bartulos Monica , Gonzalez Maria-Angeles , Matute Belinda
Published: September 2013

Background: Hospital administrative data have been suggested as a valuable cost-effective tool for providing information about the stroke burden. Nevertheless, the choice of the diagnosis codes has been a critical issue in the development of case ascertainment algorithms. Methods: In this study, the Minimum Basic Data Set administrative database was used to analyze the accuracy of different ICD-9-CM algorithms based on the neurologist's clinical judgement as the ‘gold standard'. Results: The most accurate algorithm observed in our study involved the selection of ICD-9-CM codes 430-438 in the primary diagnosis. It yielded a sensitivity of 96.1%, a specificity of 87.5% and a positive predictive value of 82.5%. Conclusions: The Minimum Basic Data Set is a valuable source to evaluate stroke frequency when using an accurate algorithm to select events.
Molecular and Gene Network Analysis of Thyroid Transcription Factor 1 (TTF1) and Enhanced at Puberty (EAP1) Genes in Patients with GnRH-Dependent Pubertal Disorders
Authors: Cukier Priscilla , Wright Hollis , Rulfs Tomke , Silveira Leticia Ferreira Gontijo , Teles Milena Gurgel , Mendonca Berenice Bilharinho , Arnhold Ivo J.P. , Heger Sabine , Latronico Ana Claudia , Ojeda Sergio R. , Brito Vinicius Nahime
Published: September 2013

Background/Aim: TTF1 and EAP1 are transcription factors that modulate gonadotropin-releasing hormone expression. We investigated the contribution of TTF1 and EAP1 genes to central pubertal disorders. Patients and Methods: 133 patients with central pubertal disorders were studied: 86 with central precocious puberty and 47 with normosmic isolated hypogonadotropic hypogonadism. The coding region of TTF1 and EAP1 were sequenced. Variations of polyglutamine and polyalanine repeats in EAP1 were analyzed by GeneScan software. Association of TTF1 and EAP1 to genes implicated in timing of puberty was investigated by meta-network framework GeneMANIA and Cytoscape software. Results: Direct sequencing of the TTF1 did not reveal any mutation or polymorphisms. Four EAP1 synonymous variants were identified with similar frequencies among groups. The most common EAP1 5′-distal polyalanine genotype was the homozygous 12/12, but the genotype 12/9 was identified in 2 central precocious puberty sisters without functional alteration in EAP1 transcriptional activity. TTF1 and EAP1 were connected, via genetic networks, to genes implicated in the control of menarche. Conclusion: No TTF1 or EAP1 germline mutations were associated with central pubertal disorders. TTF1 and EAP1 may affect puberty by changing expression in response to other members of puberty-associated gene networks, or by differentially affecting the expression of gene components of these networks.
Effectiveness of Platelet Transfusion in Dengue Fever: A Randomized Controlled Trial
Authors: Assir Muhammad Zaman Khan , Kamran Umair , Ahmad Hafiz Ijaz , Bashir Sadia , Mansoor Hassan , Anees Saad Bin , Akram Javed
Published: September 2013

Background: Scientific data regarding effects of platelet transfusion on platelet count in dengue-related thrombocytopenia is scanty. Methods: A single center, randomized non-blinded trial was conducted on adult patients with dengue fever and platelet counts less than 30,000/μl. Patients were randomized to treatment and control group. Treatment group received single donor platelets. Patients with post-transfusion platelet increment (PPI) ≥10,000/μl and/or corrected count increment (CCI) ≥5,000/μl 1 h post-transfusion were considered responders. Primary outcome was platelet count increments at 24 and 72 h. Results: 87 patients were enrolled, and 43 (48.2%) received platelet transfusion. Mean PPI and CCI at 1 h post-transfusion in the treatment group were 18,800/μl and 7,000/μl respectively. 22 (53.6%) patients in the treatment group were non-responders. Mean platelet increments at 24 and 72 h were higher in the treatment group as compared to the control group. Responders showed significantly higher increments when compared to non-responders and the control group at 24 h (p = 0.004 and p < 0.001, respectively) and 72 h (p = 0.001 and p < 0.001, respectively). Significant differences were found between non-responders and the control group at 24 h (p < 0.001), but not at 72 h (p = 0.104). Patients with lower baseline platelet count were more likely to be non-responders. Platelet transfusion neither prevented development of severe bleeding nor shortened time to cessation of bleeding. Three severe transfusion reactions and two deaths occurred in treatment group. Conclusion: In this trial, almost half the patients showed no response to a high-dose platelet transfusion. Platelet transfusion did not prevent development of severe bleeding or shorten time to cessation of bleeding and was associated with significant side effects. Therefore, platelet transfusion should not be routinely done in the management of dengue fever.
Digestive Disease Management in Japan: A Report on The 6th Diagnostic Pathology Summer Fest in 2012
Authors: Ichikawa Kazuhito , Fujimori Takahiro , Moriya Takuya , Ochiai Atsushi , Yoshinaga Shigetaka , Kushima Ryouji , Nagahama Ryuji , Ohkura Yasuo , Tanaka Shinji , Ajioka Yoichi , Hirata Ichiro , Tanaka Masanori , Hoshihara Yoshio , Kinoshita Yoshikazu , Sasano Hironobu , Iwashita Akinori , Tomita Shigeki , Hirota Seiichi , Yao Takashi , Fujii Shigehiko , Matsuda Takahisa , Ueno Hideki , Ishikawa Yuichi , Takubo Kaiyo , Fukushima Noriyoshi , Sugai Tamotsu , Iwafuchi Mitsuya , Imura Jhoji , Manabe Toshiaki , Fukayama Masahisa
Published: September 2013

The 6th Diagnostic Pathology Summer Fest, held in Tokyo on August 25-26, 2012, opened its gates for everyone in the medical profession. Basic pathology training can contribute to the improvement of algorithms for diagnosis and treatment. The 6th Summer Fest with the theme ‘Pathology and Clinical Treatment of Gastrointestinal Diseases' was held at the Ito International Research Center, The University of Tokyo. On August 25, ‘Treatment of Early Gastrointestinal Cancer and New Guidelines' was discussed in the first session, followed by ‘Biopsy Diagnosis of Digestive Tract: Key Points of Pathological Diagnosis for Inflammation and Their Clinical Significance' in the second session. On August 26, cases were discussed in the third session, and issues on pathological diagnosis and classification of neuroendorcrine tumor in the fourth session. The summaries of speeches and discussions are introduced along with the statements of each speaker. This meeting was not a formal evidence-based consensus conference, and 20 experts gave talks on their areas of specialty. Discussion was focused on how the management strategy should be standardized on the algorithm of patient care.
Randomized Trial of Conventional Transseptal Needle Versus Radiofrequency Energy Needle Puncture for Left Atrial Access (the TRAVERSE‐LA Study)
Authors: Hsu Jonathan C. , Badhwar Nitish , Gerstenfeld Edward P. , Lee Randall J. , Mandyam Mala C. , Dewland Thomas A. , Imburgia Kourtney E. , Hoffmayer Kurt S. , Vedantham Vasanth , Lee Byron K. , Tseng Zian H. , Scheinman Melvin M. , Olgin Jeffrey E. , Marcus Gregory M.
Published: September 2013

Background

Transseptal puncture is a critical step in achieving left atrial (
LA
) access for a variety of cardiac procedures. Although the mechanical
B
rockenbrough needle has historically been used for this procedure, a needle employing radiofrequency (
RF
) energy has more recently been approved for clinical use. We sought to investigate the comparative effectiveness of an
RF
versus conventional needle for transseptal
LA
access.

Methods and Results

In this prospective, single‐blinded, controlled trial, 72 patients were randomized in a 1:1 fashion to an
RF
versus conventional (
BRK
‐1) transseptal needle. In an intention‐to‐treat analysis, the primary outcome was time required for transseptal
LA
access. Secondary outcomes included failure of the assigned needle, visible plastic dilator shavings from needle introduction, and any procedural complication. The median transseptal puncture time was 68% shorter using the
RF
needle compared with the conventional needle (2.3 minutes [interquartile range {
IQR
}, 1.7 to 3.8 minutes] versus 7.3 minutes [
IQR
, 2.7 to 14.1 minutes],
P
=0.005). Failure to achieve transseptal
LA
access with the assigned needle was less common using the
RF
versus conventional needle (0/36 [0%] versus 10/36 [27.8%],
P
<0.001). Plastic shavings were grossly visible after needle advancement through the dilator and sheath in 0 (0%)
RF
needle cases and 12 (33.3%) conventional needle cases (
P
<0.001). There were no differences in procedural complications (1/36 [2.8%] versus 1/36 [2.8%]).

Conclusions

Use of an
RF
needle resulted in shorter time to transseptal
LA
access, less failure in achieving transseptal
LA
access, and fewer visible plastic shavings.

Clinical Trial Registration

URL
:
http://www.clinicaltrials.gov
. Unique identifier:
NCT
01209260.
Recurrent Processing Enhances Visual Awareness but Is Not Necessary for Fast Categorization of Natural Scenes
Authors: Koivisto Mika , Kastrati Granit , Revonsuo Antti
Published: September 2013

Humans are rapid in categorizing natural scenes. Electrophysiological recordings reveal that scenes containing animals can be categorized within 150 msec, which has been interpreted to indicate that feedforward flow of information from V1 to higher visual areas is sufficient for visual categorization. However, recent studies suggest that recurrent interactions between higher and lower levels in the visual hierarchy may also be involved in categorization. To clarify the role of recurrent processing in scene categorization, we recorded EEG and manipulated recurrent processing with object substitution masking while the participants performed a go/no-go animal/nonanimal categorization task. The quality of visual awareness was measured with a perceptual awareness scale after each trial. Masking reduced the clarity of perceptual awareness, slowed down categorization speed for scenes that were not clearly perceived, and reduced the electrophysiological difference elicited by animal and nonanimal scenes after 150 msec. The results imply that recurrent processes enhance the resolution of conscious representations and thus support categorization of stimuli that are difficult to categorize on the basis of the coarse feedforward representations alone.
Embodied Comprehension of Stories: Interactions between Language Regions and Modality-specific Neural Systems
Authors: Chow Ho Ming , Mar Raymond A. , Xu Yisheng , Liu Siyuan , Wagage Suraji , Braun Allen R.
Published: September 2013

The embodied view of language processing proposes that comprehension involves multimodal simulations, a process that retrieves a comprehender's perceptual, motor, and affective knowledge through reactivation of the neural systems responsible for perception, action, and emotion. Although evidence in support of this idea is growing, the contemporary neuroanatomical model of language suggests that comprehension largely emerges as a result of interactions between frontotemporal language areas in the left hemisphere. If modality-specific neural systems are involved in comprehension, they are not likely to operate in isolation but should interact with the brain regions critical to language processing. However, little is known about the ways in which language and modality-specific neural systems interact. To investigate this issue, we conducted a functional MRI study in which participants listened to stories that contained visually vivid, action-based, and emotionally charged content. Activity of neural systems associated with visual-spatial, motor, and affective processing were selectively modulated by the relevant story content. Importantly, when functional connectivity patterns associated with the left inferior frontal gyrus (LIFG), the left posterior middle temporal gyrus (pMTG), and the bilateral anterior temporal lobes (aTL) were compared, both LIFG and pMTG, but not the aTL, showed enhanced connectivity with the three modality-specific systems relevant to the story content. Taken together, our results suggest that language regions are engaged in perceptual, motor, and affective simulations of the described situation, which manifest through their interactions with modality-specific systems. On the basis of our results and past research, we propose that the LIFG and pMTG play unique roles in multimodal simulations during story comprehension.
A Dorsal Visual Route Necessary for Global Form Perception: Evidence from Neuropsychological fMRI
Authors: Lestou Vaia , Lam Judith Mi Lin , Humphreys Katie , Kourtzi Zoe , Humphreys Glyn W.
Published: September 2013

Hierarchical models of visual processing assume that global pattern recognition is contingent on the progressive integration of local elements across larger spatial regions, operating from early through intermediate to higher-level cortical regions. Here, we present results from neuropsychological fMRI that refute such models. We report two patients, one with lesions to intermediate ventral regions and the other with damage around the intraparietal sulcus (IPS). The patient with ventral damage showed normal behavioral and BOLD responses to global Glass patterns. The patient with IPS damage was impaired in discriminating global patterns and showed a lack of significant responses to these patterns in intermediate visual regions spared by the lesion. However, this patient did show BOLD activity to translational patterns, where local element relations are important. These results suggest that activation of intermediate ventral regions is not necessary to code global patterns; instead global patterns are coded in a heterarchical fashion. High-level regions of dorsal cortex are necessary to generate global pattern coding in intermediate ventral regions; in contrast, local integration processes are not sufficient.
Attention to Detail: Why Considering Task Demands Is Essential for Single-Trial Analysis of BOLD Correlates of the Visual P1 and N1
Authors: Warbrick Tracy , Arrubla Jorge , Boers Franks , Neuner Irene , Shah N. Jon
Published: September 2013

Single-trial fluctuations in the EEG signal have been shown to temporally correlate with the fMRI BOLD response and are valuable for modeling trial-to-trial fluctuations in responses. The P1 and N1 components of the visual ERP are sensitive to different attentional modulations, suggesting that different aspects of stimulus processing can be modeled with these ERP parameters. As such, different patterns of BOLD covariation for P1 and N1 informed regressors would be expected; however, current findings are equivocal. We investigate the effects of variations in attention on P1 and N1 informed BOLD activation in a visual oddball task. Simultaneous EEG-fMRI data were recorded from 13 healthy participants during three conditions of a visual oddball task: Passive, Count, and Respond. We show that the P1 and N1 components of the visual ERP can be used in the integration-by-prediction method of EEG-fMRI data integration to highlight brain regions related to target detection and response production. Our data suggest that the P1 component of the ERP reflects changes in sensory encoding of stimulus features and is more informative for the Passive and Count conditions. The N1, on the other hand, was more informative for the Respond condition, suggesting that it can be used to model the processing of stimulus, meaning specifically discriminating one type of stimulus from another, and processes involved in integrating sensory information with response selection. Our results show that an understanding of the underlying electrophysiology is necessary for a thorough interpretation of EEG-informed fMRI analysis.
Generic Inhibition of the Selected Movement and Constrained Inhibition of Nonselected Movements during Response Preparation
Authors: Labruna Ludovica , Lebon Florent , Duque Julie , Klein Pierre-Alexandre , Cazares Christian , Ivry Richard B.
Published: September 2013

Previous studies have identified two inhibitory mechanisms that operate during action selection and preparation. One mechanism, competition resolution, is manifest in the inhibition of the nonselected response and attributed to competition between candidate actions. The second mechanism, impulse control, is manifest in the inhibition of the selected response and is presumably invoked to prevent premature response. To identify constraints on the operation of these two inhibitory mechanisms, we manipulated the effectors used for the response alternatives, measuring changes in corticospinal excitability with motor-evoked potentials to TMS. Inhibition of the selected response (impulse control) was independent of the task context, consistent with a model in which this form of inhibition is automatically triggered as part of response preparation. In contrast, inhibition of the nonselected response (competition resolution) was context-dependent. Inhibition of the nonselected response was observed when the response alternatives involved movements of the upper limbs but was absent when one response alternative involved an upper limb and the other involved a lower limb. Interestingly, competition resolution for pairs of upper limbs did not require homologous effectors, observed when a left index finger response was pitted with either a nonhomologous right index finger movement or a right arm movement. These results argue against models in which competition resolution is viewed as a generic or fully flexible process, as well as models based on strong anatomical constraints. Rather, they are consistent with models in which inhibition for action selection is constrained by the similarity between the potential responses, perhaps reflecting an experience-dependent mechanism sensitive to the past history of competitive interactions.
Deficient GABAergic Gliotransmission May Cause Broader Sensory Tuning in Schizophrenia
Authors: Hoshino Osamu
Published: September 2013

We examined how the depression of intracortical inhibition due to a reduction in ambient GABA concentration impairs perceptual information processing in schizophrenia. A neural network model with a gliotransmission-mediated ambient GABA regulatory mechanism was simulated. In the network, interneuron-to-glial-cell and principal-cell-to-glial-cell synaptic contacts were made. The former hyperpolarized glial cells and let their transporters import (remove) GABA from the extracellular space, thereby lowering ambient GABA concentration, reducing extrasynaptic GABAa receptor-mediated tonic inhibitory current, and thus exciting principal cells. In contrast, the latter depolarized the glial cells and let the transporters export GABA into the extracellular space, thereby elevating the ambient GABA concentration and thus inhibiting the principal cells. A reduction in ambient GABA concentration was assumed for a schizophrenia network. Multiple dynamic cell assemblies were organized as sensory feature columns. Each cell assembly responded to one specific feature stimulus. The tuning performance of the network to an applied feature stimulus was evaluated in relation to the level of ambient GABA. Transporter-deficient glial cells caused a deficit in GABAergic gliotransmission and reduced ambient GABA concentration, which markedly deteriorated the tuning performance of the network, broadening the sensory tuning. Interestingly, the GABAergic gliotransmission mechanism could regulate local ambient GABA levels: it augmented ambient GABA around stimulus-irrelevant principal cells, while reducing ambient GABA around stimulus-relevant principal cells, thereby ensuring their selective responsiveness to the applied stimulus. We suggest that a deficit in GABAergic gliotransmission may cause a reduction in ambient GABA concentration, leading to a broadening of sensory tuning in schizophrenia. The GABAergic gliotransmission mechanism proposed here may have an important role in the regulation of local ambient GABA levels, thereby improving the sensory tuning performance of the cortex.
Bayesian Sparse Partial Least Squares
Authors: Vidaurre Diego , van Gerven Marcel A. J. , Bielza Concha , Larrañaga Pedro , Heskes Tom
Published: September 2013

Partial least squares (PLS) is a class of methods that makes use of a set of latent or unobserved variables to model the relation between (typically) two sets of input and output variables, respectively. Several flavors, depending on how the latent variables or components are computed, have been developed over the last years. In this letter, we propose a Bayesian formulation of PLS along with some extensions. In a nutshell, we provide sparsity at the input space level and an automatic estimation of the optimal number of latent components. We follow the variational approach to infer the parameter distributions. We have successfully tested the proposed methods on a synthetic data benchmark and on electrocorticogram data associated with several motor outputs in monkeys.
A molecular perspective on generic concepts in the Hypotrachyna clade (Parmeliaceae, Ascomycota)
Authors: DIVAKAR PRADEEP K. , CRESPO ANA , NÚÑEZ-ZAPATA JANO , FLAKUS ADAM , SIPMAN HARRIE J.M. , ELIX JOHN A. , LUMBSCH H. THORSTEN
Published: September 2013

Recently, molecular phylogenetic studies have revolutionized the generic concepts in Parmeliaceae and in lichen forming fungi in general. In the present study, the generic delimitation in the Hypotrachyna clade is revised using a molecular phylogeny of nuclear ITS, LSU and mitochondrial SSU rDNA sequences of 88 hypotrachynoid taxa. Morphological and chemical features are also revised in each group. 118 sequences are newly generated for this study. Our phylogenetic analyses show the polyphyly of Hypotrachyna as currently circumscribed which falls into four well-supported and one unsupported clade. Cetrariastrum, Everniastrum and Parmelinopsis are nested within Hypotrachyna s. lat., Parmelinopsis being also polyphyletic and nested in one of the Hypotrachyna clades. Cetrariastrum is monophyletic but clustered within Everniastrum. Two alternative hypotheses tests significantly rejected the monophyly of these three genera. As a consequence, the genera Cetrariastrum, Everniastrum, and Parmelinopsis are reduced to synonymy with Hypotrachyna. Furthermore, we here propose an alternative classification to recognize the well-supported clades at subgeneric level and leave the remaining species unclassified within the genus. Five new subgenera are proposed: Hypotrachyna subgen. Cetrariastrum, Hypotrachyna subgen. Everniastrum, Hypotrachyna subgen. Longilobae, Hypotrachyna subgen. Parmelinopsis, and Hypotrachyna subgen. Sinuosae. Forty-nine new combinations are proposed.
The Assimilation of Observations from the Advanced Microwave Sounding Unit over Sea Ice in the French Global Numerical Weather Prediction System
Authors: Karbou Fatima , Rabier Florence , Prigent Catherine
Published: September 2013

The aim of this study is to test the feasibility of assimilating microwave observations from the Advanced Microwave Sounding Units (AMSU-A and AMSU-B) through the implementation of an appropriate parameterization of sea ice emissivity. AMSU observations are relevant to the description of air temperature and humidity, and their assimilation into numerical weather prediction (NWP) helps better constrain models in regions where very few observations are assimilated. A sea ice emissivity model suitable for AMSU-A and AMSU-B data is described in this paper and its impact is studied through two assimilation experiments run during the period of the Arctic winter. The first experiment is representative of the operational version of the Météo-France NWP model whereas the second simulation uses the sea ice emissivity parameterization and assimilates a selection of AMSU channels above polar regions. The assimilation of AMSU observations over sea ice is shown to have a significant effect on atmospheric analyses (in particular those of temperature and humidity). The effect on temperature induces a warming in the lower troposphere, especially around 850 hPa. This leads to an increase in the Arctic inversion strength over the ice cap by almost 2 K. An improvement in medium-range forecasts is also noticed when the NWP model assimilates AMSU observations over sea ice.
Predicting Summer Rainfall over the Yangtze–Huai Region Based on Time-Scale Decomposition Statistical Downscaling
Authors: Liu Na , Li Shuanglin
Published: September 2013

A statistical downscaling scheme based on time-scale decomposition is adapted for summer rainfall prediction over the Yangtze–Huai River region of east China. The predictors are selected from atmospheric circulation variables outputted from the dynamic system models attending the Development of a European Multimodel Ensemble System for Seasonal to Interannual Prediction program (DEMETER) or observational datasets. Both the predictand and the predictors are decomposed into interannual and decadal components. Two distinct statistical downscaling models are built for the separated time scales and the predicted results are combined to represent the total prediction. The efficiency of this approach was assessed through comparisons with the models’ raw hindcasts as well as that from one parallel statistical downscaling scheme without time-scale decomposition. The results display that the time-scale decomposition scheme leads to significant improvements in the spatial and temporal correlation coefficients (CCs) and the root-mean-square errors (RMSEs) as well. The multiyear averaged spatial CCs reach up to 0.49 for all the individual models and their multimodel ensemble (MME), and the temporal CCs at each station are significantly higher with the coefficients from 0.46 to 0.7. Furthermore, two cases, the years 1998 and 1999, are selected for comparison. The former is a relatively easy predictable case and nearly all models predicted successfully, whereas the latter is a difficult case and nearly all models failed. The results suggest significant improvements for both cases. Thus, the present statistical downscaling scheme with time-scale decomposition may be appropriate for operational predictions.
Establishing trimester-specific maternal thyroid function reference intervals
Authors: Khalid Azy S , Marchocki Zbigniew , Hayes Kevin , Lutomski Jennifer E , Joyce Caroline , Stapleton Mary , O’Mullane John , O’Donoghue Keelin
Published: September 2013

Background

Thyroid disorders are common in women of childbearing age and are associated with adverse pregnancy outcomes. Physiological changes in pregnancy and the lack of pregnancy-specific reference ranges make managing thyroid disorders in pregnancy challenging. Our aim was to establish trimester-specific thyroid function reference intervals throughout pregnancy, and to examine the prevalence of thyroid autoimmunity in otherwise euthyroid women.

Method

This was a prospective, cross-sectional study of thyroid function tests (TFTs) in pregnant women attending a large, tertiary referral maternity hospital. Patients with known thyroid disorders, autoimmune disease, recurrent miscarriage, hyperemesis gravidarum and pre-eclampsia were excluded. TFTs were analysed in the CUH biochemistry laboratory using Roche Modular E170 electrochemiluminescent immunoassay. Trimester-specific reference ranges (2.5th, 50th and 97.5th centiles) were calculated.

Results

Three-hundred-and-fifty-one women were included into the analysis. Median maternal age was 30. Thyroid-stimulating hormone concentrations showed slightly increasing median centile throughout gestation. Free thyroxine (T4) and T3 decreased throughout gestation. Table 1 demonstrates the calculated percentiles according to gestational weeks.

Conclusion

We established pregnancy-specific thyroid function reference intervals for our pregnant population, for use in clinical practice.
A review on the mechanical behaviour of curvilinear fibre composite laminated panels
Authors: Ribeiro Pedro , Akhavan Hamed , Teter Andrzej , Warmiński Jerzy
Published: September 2013

A review on works that investigate the mechanical behaviour of variable stiffness composite laminated panels is carried out in this paper. The review mostly focuses on buckling, failure and vibrations in laminates reinforced by curvilinear fibres, although other issues related to variable stiffness laminates are also addressed. The peculiarities in the formulation of curvilinear fibre reinforced plates are briefly described. As an illustration, the natural frequencies of vibration of variable stiffness composite laminated plates with curvilinear fibres are computed by an h-version type finite element code and are compared with the ones calculated using another model, based on a Third-order Shear Deformation Theory. Areas of research to explore on variable stiffness composite laminates are suggested.