572 research outputs found

    Alterations in functional connectivity for language in prematurely born adolescents

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    Recent data suggest recovery of language systems but persistent structural abnormalities in the prematurely born. We tested the hypothesis that subjects who were born prematurely develop alternative networks for processing language. Subjects who were born prematurely (n = 22; 600–1250 g birth weight), without neonatal brain injury on neonatal cranial ultrasound, and 26 term control subjects were examined with a functional magnetic resonance imaging (fMRI) semantic association task, the Wechsler Intelligence Scale for Children-III (WISC-III) and the Clinical Evaluation of Language Fundamentals (CELF). In-magnet task accuracy and response times were calculated, and fMRI data were evaluated for the effect of group on blood oxygen level dependent (BOLD) activation, the correlation between task accuracy and activation and the functional connectivity between regions activating to task. Although there were differences in verbal IQ and CELF scores between the preterm (PT) and term control groups, there were no significant differences for either accuracy or response time for the in-magnet task. Both groups activated classic semantic processing areas including the left superior and middle temporal gyri and inferior frontal gyrus, and there was no significant difference in activation patterns between groups. Clear differences between the groups were observed in the correlation between task accuracy and activation to task at P < 0.01, corrected for multiple comparisons. Left inferior frontal gyrus correlated with accuracy only for term controls and left sensory motor areas correlated with accuracy only for PT subjects. Left middle temporal gyri correlated with task accuracy for both groups. Connectivity analyses at P < 0.001 revealed the importance of a circuit between left middle temporal gyri and inferior frontal gyrus for both groups. In addition, the PT subjects evidenced greater connectivity between traditional language areas and sensory motor areas but significantly fewer correlated areas within the frontal lobes when compared to term controls. We conclude that at 12 years of age, children born prematurely and children born at term had no difference in performance on a simple lexical semantic processing task and activated similar areas. Connectivity analyses, however, suggested that PT subjects rely upon different neural pathways for lexical semantic processing when compared to term controls. Plasticity in network connections may provide the substrate for improving language skills in the prematurely born

    Unified traction and battery charging systems for electric vehicles: a sustainability perspective

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    This paper presents an analysis of unified traction and battery charging systems for electric vehicles (EVs), both in terms of operation modes and in terms of implementation cost, when compared to dedicated solutions that perform the same operation modes. Regarding the connection of the EV battery charging system with the power grid, four operation modes are analyzed: (1) Grid–to–Vehicle (G2V); (2) Vehicle–to–Grid (V2G); (3) Vehicle–to–Home (V2H); and (4) Vehicle–for–Grid (V4G). With an EV unified system, each of these operation modes can be used in single–phase and three–phase power grids. Furthermore, a cost estimation is performed for an EV unified system and for dedicated systems that can perform the same functionalities, in order to prove the benefits of the EV unified approach. The cost estimation comprises two power levels, namely 6Β kW, single–phase, related to domestic installations, and 50Β kW, three–phase, related to industrial installations. The relevance of unified traction and battery charging systems for EVs is proven for single–phase and three–phase power grids.This work has been supported by FCT – Fundação para a CiΓͺncia e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work has been supported by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017, and by the FCT Project new ERA4GRIDs PTDC/EEI-EEE/30283/2017

    Automated, high-accuracy classification of textured microstructures using a convolutional neural network

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    Crystallographic texture is an important descriptor of material properties but requires time-intensive electron backscatter diffraction (EBSD) for identifying grain orientations. While some metrics such as grain size or grain aspect ratio can distinguish textured microstructures from untextured microstructures after significant grain growth, such morphological differences are not always visually observable. This paper explores the use of deep learning to classify experimentally measured textured microstructures without knowledge of crystallographic orientation. A deep convolutional neural network is used to extract high-order morphological features from binary images to distinguish textured microstructures from untextured microstructures. The convolutional neural network results are compared with a statistical Kolmogorov–Smirnov tests with traditional morphological metrics for describing microstructures. Results show that the convolutional neural network achieves a significantly improved classification accuracy, particularly at early stages of grain growth, highlighting the capability of deep learning to identify the subtle morphological patterns resulting from texture. The results demonstrate the potential of a convolutional neural network as a tool for reliable and automated microstructure classification with minimal preprocessing

    Multidisciplinary clinic approach improves overall survival outcomes of patients with metastatic germ-cell tumors

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    Background To report our experience utilizing a multidisciplinary clinic (MDC) at Indiana University (IU) since the publication of the International Germ Cell Cancer Collaborative Group (IGCCCG), and to compare our overall survival (OS) to that of the National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) Program. Patients and methods We conducted a retrospective analysis of all patients with metastatic germ-cell tumor (GCT) seen at IU from 1998 to 2014. A total of 1611 consecutive patients were identified, of whom 704 patients received an initial evaluation by our MDC (including medical oncology, pathology, urology and thoracic surgery) and started first-line chemotherapy at IU. These 704 patients were eligible for analysis. All patients in this cohort were treated with cisplatin–etoposide-based combination chemotherapy. We compared the progression-free survival (PFS) and OS of patients treated at IU with that of the published IGCCCG cohort. OS of the IU testis cancer primary cohort (n = 622) was further compared with the SEER data of 1283 patients labeled with β€˜distant’ disease. The Kaplan–Meier method was used to estimate PFS and OS. Results With a median follow-up of 4.4 years, patients with good, intermediate, and poor risk disease by IGCCCG criteria treated at IU had 5-year PFS of 90%, 84%, and 54% and 5-year OS of 97%, 92%, and 73%, respectively. The 5-year PFS for all patients in the IU cohort was 79% [95% confidence interval (CI) 76% to 82%]. The 5-year OS for the IU cohort was 90% (95% CI 87% to 92%). IU testis cohort had 5-year OS 94% (95% CI 91% to 96%) versus 75% (95% CI 73% to 78%) for the SEER β€˜distant’ cohort between 2000 and 2014, P-value <0.0001. Conclusion The MDC approach to GCT at high-volume cancer center associated with improved OS outcomes in this contemporary dataset. OS is significantly higher in the IU cohort compared with the IGCCCG and SEER β€˜distant’ cohort

    Impact of the development of an endoscopic eradication program for Barrett's esophagus with high grade dysplasia or early adenocarcinoma on the frequency of surgery

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    Background and aims  The impact of the advent of an institutional endoscopic eradication therapy (EET) program on surgical practice for Barrett's esophagus (BE)-associated high grade dysplasia (HGD) or suspected T1a esophageal adenocarcinoma (EAC) is unknown. The aims of this study are to evaluate the different endoscopic modalities used during development of our EET program and factors associated with the use of EET or surgery for these patients after its development. Methods  Patients who underwent primary endoscopic or surgical treatment for BE-HGD or early EAC at our hospital between January 1992 and December 2014 were retrospectively identified. They were categorized by their initial modality of treatment during the first year, and the impact over time for choice of therapy was assessed by multivariable logistic regression. Results  We identified 386 patients and 80 patients who underwent EET and surgery, respectively. EET included single modality therapy in 254 (66β€Š%) patients and multimodal therapy in 132 (34β€Š%) patients. Multivariable logistic regression showed that, for each subsequent study year, EET was more likely to be performed in patients who were older ( P β€Š=β€Š0.0009), with shorter BE lengths ( P β€Š<β€Š0.0001), and with a pretreatment diagnosis of HGD ( P β€Š=β€Š0.0054) compared to surgical patients. The diagnosis of EAC did not increase the utilization of EET compared to surgery as time progressed ( P β€Š=β€Š0.8165). Conclusion  The introduction of an EET program at our hospital increased the odds of utilizing EET versus surgery over time for initial treatment of patients who were older, had shorter BE lengths or the diagnosis of BE-HGD, but not in patients with EAC

    Contributions of high- and low-quality patches to a metapopulation with stochastic disturbance

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    Β© The Author(s), 2010. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Theoretical Ecology 5 (2012): 167-179, doi:10.1007/s12080-010-0106-9.Studies of time-invariant matrix metapopulation models indicate that metapopulation growth rate is usually more sensitive to the vital rates of individuals in high-quality (i.e., good) patches than in low-quality (i.e., bad) patches. This suggests that, given a choice, management efforts should focus on good rather than bad patches. Here, we examine the sensitivity of metapopulation growth rate for a two-patch matrix metapopulation model with and without stochastic disturbance and found cases where managers can more efficiently increase metapopulation growth rate by focusing efforts on the bad patch. In our model, net reproductive rate differs between the two patches so that in the absence of dispersal, one patch is high quality and the other low quality. Disturbance, when present, reduces net reproductive rate with equal frequency and intensity in both patches. The stochastic disturbance model gives qualitatively similar results to the deterministic model. In most cases, metapopulation growth rate was elastic to changes in net reproductive rate of individuals in the good patch than the bad patch. However, when the majority of individuals are located in the bad patch, metapopulation growth rate can be most elastic to net reproductive rate in the bad patch. We expand the model to include two stages and parameterize the patches using data for the softshell clam, Mya arenaria. With a two-stage demographic model, the elasticities of metapopulation growth rate to parameters in the bad patch increase, while elasticities to the same parameters in the good patch decrease. Metapopulation growth rate is most elastic to adult survival in the population of the good patch for all scenarios we examine. If the majority of the metapopulation is located in the bad patch, the elasticity to parameters of that population increase but do not surpass elasticity to parameters in the good patch. This model can be expanded to include additional patches, multiple stages, stochastic dispersal, and complex demography.Financial support was provided by the Woods Hole Oceanographic Institution Academic Programs Office; National Science Foundation grants OCE-0326734, OCE- 0215905, OCE-0349177, DEB-0235692, DEB-0816514, DMS- 0532378, OCE-1031256, and ATM-0428122; and by National Oceanic and Atmospheric Administration National Sea Grant College Program Office, Department of Commerce, under Grant No. NA86RG0075 (Woods Hole Oceanographic Institution Sea Grant Project No. R/0-32), and Grant No. NA16RG2273 (Woods Hole Oceanographic Institution Sea Grant Project No. R/0-35)

    Integrated system for traction and battery charging of electric vehicles with universal interface to the power grid

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    This paper proposes an integrated system for traction and battery charging of electric vehicles (EVs) with universal interface to the power grid. In the proposed system, the power electronics converters comprising the traction drive system are also used for the battery charging system, reducing the required hardware, meaning the integrated characteristic of the system. Besides, this interface is universal, since it can be performed with the three main types of power grids, namely: (1) Single-phase AC power grids; (2) Three-phase AC power grids; (3) DC power grids. In these three types of interfaces with the power grid, as well as in the traction drive operation mode, bidirectional operation is possible, framing the integration of this system into an EV in the context of smart grids. Moreover, the proposed system endows an EV with an on-board fast battery charger, whose operation allows either fast or slow battery charging. The main contributes of the proposed system are detailed in the paper, and simulation results are presented in order to attain the feasibility of the proposed system.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT -Fundacao para a Ciencia e Tecnologia within the Project Scope: UID/CEC/00319/2013. This work has been supported by FCT within the Project Scope DAIPESEV - Development of Advanced Integrated Power Electronic Systems for Electric Vehicles: PTDC/EEI-EEE/30382/2017. Mr. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency. This work is part of the FCT project 0302836 NORTE-01-0145-FEDER-030283

    Sport fans' roles in value co-creation

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    Research question The sports industry has witnessed sustained growth. The cultural, symbolic and stakeholder-embedded nature of sport provides a dynamic setting for developing service research. In this context, an evolution in the logic of value creation can be observed; fans are no longer passive receivers of value but, instead, can be active value co-creators. The sport fan exhibits distinctive characteristics and an ability and willingness to integrate resources and co-produce value propositions, which necessitates an understanding of fan value co-creation. We answer one key research question: what is the role of fans in value co-creation in sports? We do so by conceptually exploring the processes through which sport fans co-create and provide value propositions. Research methods We use case exemplars to provide a base for the theoretical consideration of the role of sport fans in value co-creation. We verify and consolidate the service-dominant logic (SDL) in the sport context. However, due to the high level of abstraction of the SDL as a general theory, we utilize consumer culture theory (CCT) as a middle range theory (MRT) to bridge the gap between contextual descriptions of the role of fans and the SDL. Results and findings Fans evaluate, redefine and reposition value propositions in different sport settings. The three roles of assimilators, adaptors and authenticators in value co-creation are identified through five case exemplars. We extend the theoretical understanding of the processes through which sport fans co-create value. Implications Knowledge of the distinctive characteristics of sport fans and their roles in value co-creation will assist managers in developing effective marketing propositions. Our theoretical contribution will generate new lines of research in the field
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