Bibliografías temáticas / Neural border

Literatura académica sobre el tema "Neural border"

Autor: Grafiati

Publicado: 18 de mayo de 2024

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros

Elija tipo de fuente:

Índice

Artículos de revistas
Tesis
Libros
Capítulos de libros
Actas de conferencias
Informes

Consulte las listas temáticas de artículos, libros, tesis, actas de conferencias y otras fuentes académicas sobre el tema "Neural border".

Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.

También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.

Artículos de revistas sobre el tema "Neural border"

Li, Yongbin, Di Zhao, Takeo Horie, Geng Chen, Hongcun Bao, Siyu Chen, Weihong Liu et al. "Conserved gene regulatory module specifies lateral neural borders across bilaterians". Proceedings of the National Academy of Sciences 114, n.º 31 (17 de julio de 2017): E6352—E6360. http://dx.doi.org/10.1073/pnas.1704194114.

Texto completo

Resumen

The lateral neural plate border (NPB), the neural part of the vertebrate neural border, is composed of central nervous system (CNS) progenitors and peripheral nervous system (PNS) progenitors. In invertebrates, PNS progenitors are also juxtaposed to the lateral boundary of the CNS. Whether there are conserved molecular mechanisms determining vertebrate and invertebrate lateral neural borders remains unclear. Using single-cell-resolution gene-expression profiling and genetic analysis, we present evidence that orthologs of the NPB specification module specify the invertebrate lateral neural border, which is composed of CNS and PNS progenitors. First, like in vertebrates, the conserved neuroectoderm lateral border specifier Msx/vab-15 specifies lateral neuroblasts in Caenorhabditis elegans. Second, orthologs of the vertebrate NPB specification module (Msx/vab-15, Pax3/7/pax-3, and Zic/ref-2) are significantly enriched in worm lateral neuroblasts. In addition, like in other bilaterians, the expression domain of Msx/vab-15 is more lateral than those of Pax3/7/pax-3 and Zic/ref-2 in C. elegans. Third, we show that Msx/vab-15 regulates the development of mechanosensory neurons derived from lateral neural progenitors in multiple invertebrate species, including C. elegans, Drosophila melanogaster, and Ciona intestinalis. We also identify a novel lateral neural border specifier, ZNF703/tlp-1, which functions synergistically with Msx/vab-15 in both C. elegans and Xenopus laevis. These data suggest a common origin of the molecular mechanism specifying lateral neural borders across bilaterians.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Zaaboub, Wala, Lotfi Tlig, Mounir Sayadi y Basel Solaiman. "Neural Network-based System for Automatic Passport Stamp Classification". Information Technology And Control 49, n.º 4 (19 de diciembre de 2020): 583–607. http://dx.doi.org/10.5755/j01.itc.49.4.25919.

Texto completo

Resumen

The international tourism growth forces governments to make a big effort to improve the security of national borders. The compulsory passport stamping is used in guaranteeing the safekeeping of the entry point of the border. For each passenger, the border police must check the existence of exit stamps and/or the entry stamps of the country that the passenger visits, in all the pages of his passport. However, the systematic control considerably slows the operations of the border police. Protecting the borders from illegal immigrants and simplifying border checkpoints for law-abiding citizens and visitors is a delicate compromise. The purpose of this paper is to perform a flexible and scalable system that ensures faster, safer and more efficient stamp controlling. An automatic system of stamp extraction for travel documents is proposed. We incorporate several methods from the field of artificial intelligence, image processing and pattern recognition. At first, texture feature extraction is performed in order to find potential stamps. Next, image segmentation aimed at detecting objects of specific textures are employed. Then, isolated objects are extracted and classified using multi-layer perceptron artificial network. Promising results are obtained in terms of accuracy, with a maximum average of 0.945 among all the images, improving the performance of MLP neural network in all cases.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Craft, Edward, Hartmut Schütze, Ernst Niebur y Rüdiger von der Heydt. "A Neural Model of Figure–Ground Organization". Journal of Neurophysiology 97, n.º 6 (junio de 2007): 4310–26. http://dx.doi.org/10.1152/jn.00203.2007.

Texto completo

Resumen

Psychophysical studies suggest that figure–ground organization is a largely autonomous process that guides—and thus precedes—allocation of attention and object recognition. The discovery of border-ownership representation in single neurons of early visual cortex has confirmed this view. Recent theoretical studies have demonstrated that border-ownership assignment can be modeled as a process of self-organization by lateral interactions within V2 cortex. However, the mechanism proposed relies on propagation of signals through horizontal fibers, which would result in increasing delays of the border-ownership signal with increasing size of the visual stimulus, in contradiction with experimental findings. It also remains unclear how the resulting border-ownership representation would interact with attention mechanisms to guide further processing. Here we present a model of border-ownership coding based on dedicated neural circuits for contour grouping that produce border-ownership assignment and also provide handles for mechanisms of selective attention. The results are consistent with neurophysiological and psychophysical findings. The model makes predictions about the hypothetical grouping circuits and the role of feedback between cortical areas.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Milet, Cécile y Anne H. Monsoro-Burq. "Neural crest induction at the neural plate border in vertebrates". Developmental Biology 366, n.º 1 (junio de 2012): 22–33. http://dx.doi.org/10.1016/j.ydbio.2012.01.013.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Shen, Jianjun. "Research on the International Trade Performance Evaluation of Cross-Border e-Commerce Based on the Deep Neural Network Model". Journal of Sensors 2022 (8 de octubre de 2022): 1–9. http://dx.doi.org/10.1155/2022/3006907.

Texto completo

Resumen

The rapid development of e-commerce international trade has driven the rapid growth of the economic system of international trade enterprises. This also means that industry competition is gradually intensifying, which also makes performance evaluation the key to cross-border e-commerce international trade. At present, my country’s research on the performance evaluation of cross-border e-commerce international trade is in a blank state. Therefore, this paper takes the international trade performance evaluation of cross-border e-commerce as the research object and, based on the deep neural network model, develops a cross-border international trade performance evaluation model, changes trade strategies, and improves trade performance. This paper first analyzes various neural network models, such as artificial neural network, “BP” neuron model, and LSTM neural network. This paper summarizes a deep neural network model that is conducive to the development of cross-border e-commerce and points out the problems in the current performance evaluation of cross-border e-commerce international trade: the e-commerce market supervision system is not perfect; the second is the inconsistent evaluation indicators; the third is the evaluation system. There are some differences with the actual. Finally, this paper puts forward relevant suggestions for the performance evaluation of cross-border e-commerce international trade and points out the advantages and disadvantages of various neural networks, as well as their roles in cross-border e-commerce performance evaluation, and compares these neural networks through experiments. Experiments show that among these neural network models, the deep neural network model is the best and has the highest accuracy and stability in e-commerce trade performance evaluation. In the later stage, we will improve the global logistics system, strengthen the application of big data technology, and improve the overall performance of global operations. First, a set of indicators is designed to evaluate the performance of e-commerce systems, using the enterprise key factor model concept. In addition, this evaluation method is different from the commonly used expert evaluation method and physical evaluation method in evaluating the construction quality, cost, education and growth ability, and performance level of the international business system of cross-border e-commerce.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Birgbauer, E., J. Sechrist, M. Bronner-Fraser y S. Fraser. "Rhombomeric origin and rostrocaudal reassortment of neural crest cells revealed by intravital microscopy". Development 121, n.º 4 (1 de abril de 1995): 935–45. http://dx.doi.org/10.1242/dev.121.4.935.

Texto completo

Resumen

Neural crest cell migration in the hindbrain is segmental, with prominent streams of migrating cells adjacent to rhombomeres (r) r2, r4 and r6, but not r3 or r5. This migratory pattern cannot be explained by the failure of r3 and r5 to produce neural crest, since focal injections of the lipophilic dye, DiI, into the neural folds clearly demonstrate that all rhombomeres produce neural crest cells. Here, we examine the dynamics of hindbrain neural crest cell emigration and movement by iontophoretically injecting DiI into small numbers of cells. The intensely labeled cells and their progeny were repeatedly imaged using low-light-level epifluorescence microscopy, permitting their movement to be followed in living embryos over time. These intravital images definitively show that neural crest cells move both rostrally and caudally from r3 and r5 to emerge as a part of the streams adjacent to r2, r4, and/or r6. Within the first few hours, cells labeled in r3 move within and/or along the dorsal neural tube surface, either rostrally toward the r2/3 border or caudally toward the r3/4 border. The labeled cells exit the surface of the neural tube near these borders and migrate toward the first or second branchial arches several hours after initial labeling. Focal DiI injections into r5 resulted in neural crest cell contributions to both the second and third branchial arches, again via rostrocaudal movements of the cells before migration into the periphery. These results demonstrate conclusively that all rhombomeres give rise to neural crest cells, and that rostrocaudal rearrangement of the cells contributes to the segmental migration of neural crest cells adjacent to r2, r4, and r6. Furthermore, it appears that there are consistent exit points of neural crest cell emigration; for example, cells arising from r3 emigrate almost exclusively from the rostral or caudal borders of that rhombomere.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Rideaux, Reuben y William J. Harrison. "Border ownership-dependent tilt aftereffect for shape defined by binocular disparity and motion parallax". Journal of Neurophysiology 121, n.º 5 (1 de mayo de 2019): 1917–23. http://dx.doi.org/10.1152/jn.00111.2019.

Texto completo

Resumen

Discerning objects from their surrounds (i.e., figure-ground segmentation) in a way that guides adaptive behaviors is a fundamental task of the brain. Neurophysiological work has revealed a class of cells in the macaque visual cortex that may be ideally suited to support this neural computation: border ownership cells (Zhou H, Friedman HS, von der Heydt R. J Neurosci 20: 6594–6611, 2000). These orientation-tuned cells appear to respond conditionally to the borders of objects. A behavioral correlate supporting the existence of these cells in humans was demonstrated with two-dimensional luminance-defined objects (von der Heydt R, Macuda T, Qiu FT. J Opt Soc Am A Opt Image Sci Vis 22: 2222–2229, 2005). However, objects in our natural visual environments are often signaled by complex cues, such as motion and binocular disparity. Thus for border ownership systems to effectively support figure-ground segmentation and object depth ordering, they must have access to information from multiple depth cues with strict depth order selectivity. Here we measured in humans (of both sexes) border ownership-dependent tilt aftereffects after adaptation to figures defined by either motion parallax or binocular disparity. We find that both depth cues produce a tilt aftereffect that is selective for figure-ground depth order. Furthermore, we find that the effects of adaptation are transferable between cues, suggesting that these systems may combine depth cues to reduce uncertainty (Bülthoff HH, Mallot HA. J Opt Soc Am A 5: 1749–1758, 1988). These results suggest that border ownership mechanisms have strict depth order selectivity and access to multiple depth cues that are jointly encoded, providing compelling psychophysical support for their role in figure-ground segmentation in natural visual environments. NEW & NOTEWORTHY Figure-ground segmentation is a critical function that may be supported by “border ownership” neural systems that conditionally respond to object borders. We measured border ownership-dependent tilt aftereffects to figures defined by motion parallax or binocular disparity and found aftereffects for both cues. These effects were transferable between cues but selective for figure-ground depth order, suggesting that the neural systems supporting figure-ground segmentation have strict depth order selectivity and access to multiple depth cues that are jointly encoded.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Li, Yanting. "A Cloud Computing-Based Intelligent Forecasting Method for Cross-Border E-Commerce Logistics Costs". Advances in Mathematical Physics 2022 (29 de marzo de 2022): 1–10. http://dx.doi.org/10.1155/2022/3838293.

Texto completo

Resumen

Aiming at the problems of poor forecasting effect and low accuracy and low efficiency in current cross-border e-commerce logistics cost prediction methods, a cloud computing-based intelligent method for cross-border e-commerce logistics cost prediction is proposed. Analyze cloud computing concepts, characteristics, and service models, study cloud computing-related technologies, and train BP neural network algorithms based on BP neural network principles. The BP neural network structure is obtained by determining the number of neurons in the input layer, the number of neurons in the hidden layer, the number of neurons in the output layer, and the activation function of the neural network. Normalize the input data samples of the input layer, and select the initial weight, threshold, and learning rate parameters of the BP neural network to determine the momentum coefficient. This paper uses neural network model combined with Spark cloud computing platform to realize the intelligent prediction of cross-border e-commerce logistics cost. This method has good predictive ability. After a large amount of data input and output relationship training, it has obtained the most suitable model for prediction. The experimental results show that the cross-border e-commerce logistics cost prediction effect of the proposed method is good, and it can effectively improve the accuracy and efficiency of cross-border e-commerce logistics cost prediction.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Long, Gerald M. y Philip M. Garvey. "The Effects of Target Borders on Dynamic Visual Acuity: Practical and Theoretical Implications". Perception 17, n.º 6 (diciembre de 1988): 745–51. http://dx.doi.org/10.1068/p170745.

Texto completo

Resumen

The effects of target borders on the ability of observers to resolve moving targets (Landolt Cs) under a range of conditions were examined. Contrary to reported findings with stationary targets, it was predicted that the presence of borders would improve acuity for slow-moving targets because (i) overall stimulus energy is kept relatively constant as target detail varies, and (ii) a low-spatial-frequency component is held constant as target detail varies. In an experiment in which a two-sided border (above and below the target) was used, the predicted beneficial effect of the border at slow speeds was obtained. The results are discussed in terms of practical implications for the assessment of dynamic visual acuity as well as the potential neural mechanisms underlying performance.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Zhao, ShuTong, Zhenjie Yin y Pingping Xie. "Multi-angle perception and convolutional neural network for service quality evaluation of cross-border e-commerce logistics enterprise". PeerJ Computer Science 10 (29 de febrero de 2024): e1911. http://dx.doi.org/10.7717/peerj-cs.1911.

Texto completo

Resumen

The development of cross-border e-commerce logistics services has injected new vitality into the development of international trade, and therefore has become a new hot spot in theoretical research. In order to ensure the healthy development of cross-border e-commerce, it is urgent to build a set of scientific and effective evaluation mechanisms to scientifically evaluate the logistics service quality of cross-border e-commerce. Multi-angle perceptual convolutional neural network is a framework for service scene identification of cross-border e-commerce logistics enterprises based on deep convolutional neural network and multi-angle perceptual width learning. In this article, both shallow features and deep features were input into the deep perception model (DPM) to obtain a set of distinguishable features with causal structure, which was used to completely describe the high-level semantic information of cross-border e-commerce logistics enterprise services. Among them, DPM mainly adopts the fusion strategy of shallow feature and deep feature. Meanwhile, the feature representation is input into the width learning pattern recognition system for training and classification, so as to evaluate the service quality of cross-border e-commerce logistics enterprises. The multi-angle perceptual convolutional neural network can effectively solve the problems of high similarity between service classes of cross-border e-commerce logistics enterprises and large differences within the class, and achieve better generalization performance and algorithm complexity than support vector machine, random forest and convolutional neural network.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Más fuentes

Tesis sobre el tema "Neural border"

Blair, Joel. "Building a better Placode: Modeling Neural Plate Border interactions with hPSCs". University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1627663141272833.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Patthey, Cédric. "Induction of the isthmic organizer and specification of the neural plate border". Doctoral thesis, Umeå universitet, Umeå centrum för molekylär medicin (UCMM), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1811.

Texto completo

Resumen

The vertebrate nervous system is extremely complex and contains a wide diversity of cell types. The formation of a functional nervous system requires the differential specification of progenitor cells at the right time and place. The generation of many different types of neurons along the rostro-caudal axis of the CNS begins with the initial specification of a few progenitor domains. This initial coarse pattern is refined by so-called secondary organizers arising at boundaries between these domains. The Isthmic Organizer (IsO) is a secondary organizer located at the boundary between the midbrain and the hindbrain. Although the function and maintenance of the IsO are well understood, the processes underlying its initial specification have remained elusive. In the present work we provide evidence that convergent Wnt and FGF signals initiate the specification of the IsO during late gastrulation as part of the neural caudalization process. The initial step in the generation of the nervous system is the division of the embryonic ectoderm into three cell populations: neural cells giving rise to the CNS, neural plate border cells giving rise to the peripheral nervous system, and epidermal cells giving rise to the outer layer of the skin. While the choice between neural and epidermal fate has been well studied, the mechanism by which neural plate border cells are generated is less well understood. At rostral levels of the neuraxis, the neural plate border gives rise to the olfactory and lens placodes, thickenings of the surface ectoderm from which sensory organs are derived. More caudally, the neural plate border generates neural crest cells, a transient population that migrates extensively and contributes to neurons and glia of the peripheral nervous system. How the early patterning of the central and peripheral nervous systems are coordinated has remained poorly understood. Here we show that the generation of neural plate border cells is initiated at the late blastula stage and involves two phases. During the first phase, neural plate border cells are exposed to Wnt signals in the absence of BMP signals. Simultaneous exposure to Wnt and BMP signals at this early stage leads to epidermal induction. Wnt signals induce expression of Bmp4, thereby regulating the sequential exposure of cells to Wnt and BMP signals. During the second phase, at the late gastrula stage, BMP signals play an instructive role to specify neural plate border cells of either placodal or neural crest character depending on the status of Wnt signaling. At this stage, Wnt signals promote caudal character simultaneously in the neural plate border and in the neural ectoderm. Thus, the choice between epidermal and neural plate border specification is mediated by an interplay of Wnt and BMP signals that represents a novel mechanism involving temporal control of BMP activity by Wnt signals. Moreover, the early development of the central and peripheral nervous systems are coordinated by simultaneous caudalization by Wnt signals.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Patthey, Cédric. "Induction of the isthmic organizer and specification of the neural plate border /". Umeå : Univ, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1811.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Herng, Eduardo Wu Jyh. "Detecção de bordas em imagens de ecocardiografia utilizando redes neurais artificiais". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/98/98131/tde-04062012-083028/.

Texto completo

Resumen

Por ser não-invasiva e de baixo custo, a Ecocardiografia tem se tornado uma técnica de diagnóstico muito utilizada para a determinação dos volumes sistólicos e diastólicos do ventrículo esquerdo a fim de se calcular, indiretamente, o volume de ejeção do ventrículo esquerdo, a razão de contração muscular das cavidades cardíacas, a fração de ejeção regional e global, a espessura do miocárdio e a massa ventricular. Para isso, torna-se necessária a detecção das bordas endocárdicas do ventrículo esquerdo, o que é dificultada pelo fato da imagem de Ecocardiografia possuir ruídos que prejudicam sua definição. Apesar de haver várias técnicas de segmentação de imagem, este trabalho propõe detectar as bordas do ventrículo esquerdo de imagens ecocardiográficas utilizando uma rede neural artificial para reconhecer padrões de bordas. A fim de acelerar o processo e facilitar o processamento, uma área retangular centrada dentro da janela acústica do paciente é determinada pelo operador com o uso do \'mouse\' na qual serão realizadas todas as análises e reconhecimentos de borda pela rede neural. Após a marcação dos pontos reconhecidos pela rede neural como bordas, utilizam-se técnicas de gradientes e contorno móvel para se conectar os pontos de maior probabilidade e traçar a borda do ventrículo esquerdo. Esta técnica mostrou-se eficaz quando comparados com as bordas traçadas pelo especialista, sendo um fator importante a prática do operador ao escolher adequadamente a área a ser analisada. Após treinamento com 50 amostras de padrões de \"borda\" e 10 amostras de padrões de \"não borda\", a técnica foi testada em 108 imagens, alcançando resultados com boa precisão e rapidez quando comparamos os resultados na determinação da área do ventrículo esquerdo com outras técnicas citadas na literatura nacional e internacional.
Being non-invasive and having low cost, the echocardiography has been largely applied as diagnostic technique for left ventricle systolic and diastolic volumes determination that indirectly are used to calculate the left ventricle ejection volume, the cardiac cavities muscular contraction, the regional and global ejection fraction, the myocardial thickness, the ventricular mass, etc. For this reason, the detection of the left ventricle endocardial borders become necessary, but hampered by the noise that impairs the echocardiography images definition. In spite of having many image segmentation techniques, this work intend to detect the borders of left ventricle on echocardiography images by using a artificial neural network to recognize border patterns. To accelerate the process and facilitate the procedure, the operator uses the mouse to define a rectangular region inside the acoustic window of the pacient where all analyses and border recognitions will be accomplished. After labeling the recognized points as \'border\', gradient techniques and mobile boundary are used to connect the points of greater probability and delineate the left ventricle border. This technique has proved to be efficient when compared to the borders traced by the specialist. The ability of the operator is important in choosing of the region to be analyzed. After training with 50 samples of \"border\" pattern and 10 samples of \"no-border\" pattern, this technique was tested on 108 images, achieving good results on precision and velocitiy when we compared the calculated left ventricle area with the results of other techniques published on national and international literature.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Rossi, Christy Cortez. "Early development of two cell populations at the neural plate border : rohon-beard sensory neurons and neural crest cells /". Connect to full text via ProQuest. Limited to UCD Anschutz Medical Campus, 2008.

Buscar texto completo

Resumen

Thesis (Ph.D. in Neuroscience) -- University of Colorado Denver, 2008.
Includes bibliographical references (leaves 112-120). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;

Los estilos APA, Harvard, Vancouver, ISO, etc.

Liu, Boqi. "The gene regulatory network in the anterior neural plate border of ascidian embryos". Kyoto University, 2020. http://hdl.handle.net/2433/253119.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

White, Cory B. "A Neural Network Approach to Border Gateway Protocol Peer Failure Detection and Prediction". DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/215.

Texto completo

Resumen

The size and speed of computer networks continue to expand at a rapid pace, as do the corresponding errors, failures, and faults inherent within such extensive networks. This thesis introduces a novel approach to interface Border Gateway Protocol (BGP) computer networks with neural networks to learn the precursor connectivity patterns that emerge prior to a node failure. Details of the design and construction of a framework that utilizes neural networks to learn and monitor BGP connection states as a means of detecting and predicting BGP peer node failure are presented. Moreover, this framework is used to monitor a BGP network and a suite of tests are conducted to establish that this neural network approach as a viable strategy for predicting BGP peer node failure. For all performed experiments both of the proposed neural network architectures succeed in memorizing and utilizing the network connectivity patterns. Lastly, a discussion of this framework's generic design is presented to acknowledge how other types of networks and alternate machine learning techniques can be accommodated with relative ease.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Grieves, Roderick McKinlay. "The neural basis of a cognitive map". Thesis, University of Stirling, 2015. http://hdl.handle.net/1893/21878.

Texto completo

Resumen

It has been proposed that as animals explore their environment they build and maintain a cognitive map, an internal representation of their surroundings (Tolman, 1948). We tested this hypothesis using a task designed to assess the ability of rats to make a spatial inference (take a novel shortcut)(Roberts et al., 2007). Our findings suggest that rats are unable to make a spontaneous spatial inference. Furthermore, they bear similarities to experiments which have been similarly unable to replicate or support Tolman’s (1948) findings. An inability to take novel shortcuts suggests that rats do not possess a cognitive map (Bennett, 1996). However, we found evidence of alternative learning strategies, such as latent learning (Tolman & Honzik, 1930b) , which suggest that rats may still be building such a representation, although it does not appear they are able to utilise this information to make complex spatial computations. Neurons found in the hippocampus show remarkable spatial modulation of their firing rate and have been suggested as a possible neural substrate for a cognitive map (O'Keefe & Nadel, 1978). However, the firing of these place cells often appears to be modulated by features of an animal’s behaviour (Ainge, Tamosiunaite, et al., 2007; Wood, Dudchenko, Robitsek, & Eichenbaum, 2000). For instance, previous experiments have demonstrated that the firing rate of place fields in the start box of some mazes are predictive of the animal’s final destination (Ainge, Tamosiunaite, et al., 2007; Ferbinteanu & Shapiro, 2003). We sought to understand whether this prospective firing is in fact related to the goal the rat is planning to navigate to or the route the rat is planning to take. Our results provide strong evidence for the latter, suggesting that rats may not be aware of the location of specific goals and may not be aware of their environment in the form of a contiguous map. However, we also found behavioural evidence that rats are aware of specific goal locations, suggesting that place cells in the hippocampus may not be responsible for this representation and that it may reside elsewhere (Hok, Chah, Save, & Poucet, 2013). Unlike their typical activity in an open field, place cells often have multiple place fields in geometrically similar areas of a multicompartment environment (Derdikman et al., 2009; Spiers et al., 2013). For example, Spiers et al. (2013) found that in an environment composed of four parallel compartments, place cells often fired similarly in multiple compartments, despite the active movement of the rat between them. We were able to replicate this phenomenon, furthermore, we were also able to show that if the compartments are arranged in a radial configuration this repetitive firing does not occur as frequently. We suggest that this place field repetition is driven by inputs from Boundary Vector Cells (BVCs) in neighbouring brain regions which are in turn greatly modulated by inputs from the head direction system. This is supported by a novel BVC model of place cell firing which predicts our observed results accurately. If place cells form the neural basis of a cognitive map one would predict spatial learning to be difficult in an environment where repetitive firing is observed frequently (Spiers et al., 2013). We tested this hypothesis by training animals on an odour discrimination task in the maze environments described above. We found that rats trained in the parallel version of the task were significantly impaired when compared to the radial version. These results support the hypothesis that place cells form the neural basis of a cognitive map; in environments where it is difficult to discriminate compartments based on the firing of place cells, rats find it similarly difficult to discriminate these compartments as shown by their behaviour. The experiments reported here are discussed in terms of a cognitive map, the likelihood that such a construct exists and the possibility that place cells form the neural basis of such a representation. Although the results of our experiments could be interpreted as evidence that animals do not possess a cognitive map, ultimately they suggest that animals do have a cognitive map and that place cells form a more than adequate substrate for this representation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

An, Min. "Positional cloning and functional analysis of the SF3B1gene in zebrafish". Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1180528932.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Ghimouz, Rym. "Caractérisation du rôle des facteurs de transcription Homez et CBFbeta au cours de la neurogenèse et de la formation de la crête neurale chez Xenopus laevis". Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209568.

Texto completo

Resumen

Le but des recherches du laboratoire de génétique du développement est de mieux comprendre les mécanismes moléculaires qui contrôlent le développement neural des vertébrés. C’est la raison pour la quelle, j’ai identifié deux EST (BC071005 et BC077938) spécifiques de l’expression génique chez le Xenopus laevis. Sur base de la littérature, ces deux gènes présentent des profils d’expression intéressants, caractéristiques des gènes impliqués dans la neurogenèse.

Le premier clone d’ADNc code pour l’homologue du facteur de transcription Homez, contenant trois homéodomaines et deux motifs leucine zipper et dont la fonction est inconnue. Mes résultats ont montré que chez l’embryon de xénope au stade neurula, Homez est exprimé préférentiellement dans la plaque neurale, l’expression la plus forte étant détectée dans les domaines où les neurones primaires apparaissent. Plus tard, Homez est détecté dans le tube neural dans des cellules neurales postmitotiques en cours de différenciation. En accord avec ce profil d’expression, j’ai observé que Homez est régulé positivement par l’atténuation des signaux BMPs et par le facteur proneural Ngnr1 et négativement par la voie Notch. Bien que le facteur Homez ne soit pas suffisant pour induire une expression ectopique de marqueurs neuronaux dans l’embryon de xénope, j’ai pu montrer, en utilisant une approche de morpholino antisens, que celui-ci est requis en aval du facteur Ngnr1 pour la différenciation des précurseurs neuraux en neurones primaires.

Le deuxième clone code pour l’homologue du facteur CBFβ qui s’associe avec une famille de protéines CBFα1-3/Aml1-3/Runx1-3 pour former un complexe hétérodimérique liant l’ADN. Alors que chez la souris, les facteurs Runx1 et Runx3 jouent un rôle important dans la neurogenèse dans les ganglions spinaux et que chez le xénope, Runx1 est requis pour la formation des neurones Rohon-Beard, le rôle de CBFβ au cours du développement du système nerveux est actuellement mal connu. Mes résultats ont montré que chez l’embryon de xénope au stade neurula, CBFβ est coexprimé avec les facteurs Runx1-3 en bordure de la plaque neurale, mais de manière plus étendue et plus précoce. Comme attendu pour un marqueur de la bordure de la plaque neurale, j’ai observé que l’expression de CBFβ est régulée par les signaux BMP, Wnt, FGF et Notch. De manière intéressante, son expression est induite par les facteurs proneuraux alors que celle de Runx1 est inhibée. Des expériences de perte de fonction à l’aide de morpholinos antisens bloquant la traduction de CBFβ ont été réalisées. Ces expériences suggèrent que le facteur CBFβ est nécessaire à la mise en place de la CN et à la différenciation des neurones de Rohon-Beard.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Los estilos APA, Harvard, Vancouver, ISO, etc.

Más fuentes

Libros sobre el tema "Neural border"

Chappell, Michael, Bradley MacIntosh y Thomas Okell. Introduction to Perfusion Quantification using Arterial Spin Labelling. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198793816.001.0001.

Texto completo

Resumen

Arterial spin labeling (ASL) magnetic resonance imaging (MRI) is unique in being a completely non-invasive method for imaging perfusion in the brain. Relying upon a blood-borne tracer that is created by the MRI scanner itself, ASL is becoming a popular tool to study cerebral perfusion, as well as how this perfusion changes in response to neuronal activity or in disease. This primer provides an introduction to perfusion quantification using ASL MRI, focusing both on the methods needed to extract perfusion-weighted images and on how to quantify perfusion and other hemodynamic parameters. Starting with the simplest implementation of ASL, the primer details all the common acquisition methods, as well as the subsequent analysis steps required to quantify perfusion in an individual, detect changes in perfusion in response to neural activity or pharmacological intervention, and examine perfusion variations across groups of individuals. This is supported with examples from real data illustrating all the major steps in the analysis process, linked to online material where the reader can undertake the same analysis for themselves.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Rijpma, Jorrit J. Brave New Borders: The EU’s Use of New Technologies for the Management of Migration and Asylum. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780198807216.003.0007.

Texto completo

Resumen

This chapter shows how in the 21st century new technologies and new bureaucracies have become part and parcel of the EU’s migration and asylum policy, and how these two are intimately linked. Together they have allowed the EU and its Member States to tighten their grip over the movement of people. The use of technology has transformed the nature of the European border and has reinforced the agencies in charge of its management. This has largely been done without a clearly defined vision or grand design. Rather, it was technology itself that enabled this development and has greatly helped to shape it. While technology has often been portrayed as value-neutral, it may now pose challenges to some of the EU’s fundamental rights, most notably the right to data protection.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Altman, Meryl. The Grand Rectification. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190608811.003.0008.

Texto completo

Resumen

This chapter praises the 2010 translation of The Second Sex, driven by criticism of H.M. Parshley’s original translation by writers like Toril Moi, which was received with mixed reviews, reigniting the old controversy over the success of the English translation of Beauvoir’s message. In her review, Meryl Altman defends not only the choice of translators, but also the integrity of their work. In fact, Altman observes, Borde and Malovany-Chevallier’s lack of “professional stakes” in the translation prevented them from adding words here and there to generate a “more opinionated” translation. Rather, she claims, Borde and Malovany-Chevallier remain neutral and resist the temptation of modernizing Beauvoir by importing anachronisms that would have obscured the meaning of Beauvoir’s key philosophical insights. Ultimately, Altman argues that the new translation succeeds at refreshing sections of the text, restoring the many authors that Beauvoir cites, and rekindling an interest in Beauvoir and feminism.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Agius, Christine. Rescuing the State? Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190644031.003.0005.

Texto completo

Resumen

This chapter explores how two middle powers, Sweden and Australia, deploy the politics of protection in different ways. Sweden’s efforts to remake the state is viewed through a gender lens as part of efforts to disentangle its former neutral profile through more robust military applications, whilst embodying a peaceful self-narrative linked to military non-alignment, active internationalism and a ‘feminist foreign policy’. The second case explores efforts to reclaim a bounded concept of the sovereign state in Australia's masculinist and militarized approach to securing its borders with respect to asylum seekers. Australia seeks to reclaim a more traditional imagining of the state, or a return to ‘restoring’ state sovereignty perceived to be under threat by globalising forces. Both case studies explore the inherently gendered and securitized reworking and revisioning of the state, and the tensions and contradictions that emerge in questions of security, sovereignty and identity.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Kurevska, Līga. Designing Regulatory Framework for Demand Response Service Integration in Baltic Electricity Markets. RTU Press, 2022. http://dx.doi.org/10.7250/9789934227974.

Texto completo

Resumen

Mitigating climate change is one our generation’s greatest challenges; however, similarly to many public goods where benefits are enjoyed by many while the costs are born by few, finding a balance between the pace of the change and cost borne by society can be complicated. To raise to this challenge, policy makers must reconcile naturally conflicting objectives – technical system reliability, uptake of new, climate-neutral technology, and low energy costs. The tools developed during the research as well as the findings can support policy makers in developing market regulation and decide on the necessity for additional stimulus to accelerate the pace of demand response service participation in electricity markets.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Bindemann, Markus, ed. Forensic Face Matching. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198837749.001.0001.

Texto completo

Resumen

Person identification at passport control, at borders, in police investigations, and in criminal trials relies critically on the identity verification of people via image-to-image or person-to-image comparison. While this task is known as ‘facial image comparison’ in forensic settings, it has been studied as ‘unfamiliar face matching’ in cognitive science. This book brings together expertise from practitioners, and academics in psychology and law, to draw together what is currently known about these tasks. It explains the problem of identity impostors and how within-person variability and between-person similarity, due to factors such as image quality, lighting direction, and view, affect identification. A framework to develop a cognitive theory of face matching is offered. The face-matching abilities of untrained lay observers, facial reviewers, facial examiners, and super-recognizers are analysed and contrasted. Individual differences between observers, learning and training for face recognition and face matching, and personnel selection are reviewed. The admissibility criteria of evidence from face matching in legal settings are considered, focusing on aspects such as the requirement of relevance, the prohibition on evidence of opinion, and reliability. Key concepts relevant to automatic face recognition algorithms at airports and in police investigations are explained, such as deep convolutional neural networks, biometrics, and human–computer interaction. Finally, new security threats in the form of hyper-realistic mask disguises are considered, including the impact these have on person identification in applied and laboratory settings.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Capítulos de libros sobre el tema "Neural border"

Nakata, Yusuke y Ko Sakai. "Structures of Surround Modulation for the Border-Ownership Selectivity of V2 Cells". En Neural Information Processing, 383–91. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-34475-6_46.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Zainal, Zaem Arif y Shunji Satoh. "Formulation of Border-Ownership Assignment in Area V2 as an Optimization Problem". En Neural Information Processing, 859–66. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-70090-8_87.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Bronner-Fraser, Marianne. "The Neural Crest: Migrating from the Border". En Cell Migration in Development and Disease, 155–71. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2005. http://dx.doi.org/10.1002/3527604669.ch9.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Sakai, Ko y Shunsuke Michii. "Latency Modulation of Border Ownership Selective Cells in V1-V2 Feed-Forward Model". En Neural Information Processing, 291–300. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-42051-1_37.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Kikuchi, Masayuki y Youhei Akashi. "A Model of Border-Ownership Coding in Early Vision". En Artificial Neural Networks — ICANN 2001, 1069–74. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/3-540-44668-0_148.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Hosoya, Haruo. "Bayesian Interpretation of Border-Ownership Signals in Early Visual Cortex". En Neural Information Processing. Theory and Algorithms, 1–8. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-17537-4_1.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Wagatsuma, Nobuhiko y Hirotoshi Konno. "The Effects of Feedback Signals Mediated by NMDA-Type Synapses for Modulating Border-Ownership Selective Neurons in Visual Cortex". En Neural Information Processing, 563–70. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-04167-0_51.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Wagatsuma, Nobuhiko y Ko Sakai. "Roles of Early Vision for the Dynamics of Border-Ownership Selective Neurons". En Neural Information Processing. Theory and Algorithms, 99–106. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-17537-4_13.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Rana, Mashud y Irena Koprinska. "Wavelet Neural Networks for Electricity Load Forecasting – Dealing with Border Distortion and Shift Invariance". En Artificial Neural Networks and Machine Learning – ICANN 2013, 571–78. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-40728-4_71.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Jadhav, Ashwin R., Arun G. Ghontale y Vimal K. Shrivastava. "Segmentation and Border Detection of Melanoma Lesions Using Convolutional Neural Network and SVM". En Computational Intelligence: Theories, Applications and Future Directions - Volume I, 97–108. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-1132-1_8.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Actas de conferencias sobre el tema "Neural border"

Carlos-Roca, Laura Rodriguez, Isabelle Hupont Torres y Carles Fernandez Tena. "Facial recognition application for border control". En 2018 International Joint Conference on Neural Networks (IJCNN). IEEE, 2018. http://dx.doi.org/10.1109/ijcnn.2018.8489113.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Karimi, Mohsen, Ali Jahanshahi, Abbas Mazloumi y Hadi Zamani Sabzi. "Border Gateway Protocol Anomaly Detection Using Neural Network". En 2019 IEEE International Conference on Big Data (Big Data). IEEE, 2019. http://dx.doi.org/10.1109/bigdata47090.2019.9006201.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Hsu, Chih-Chieh y Alice C. Parker. "Border ownership in a nano-neuromorphic circuit using nonlinear dendritic computations". En 2014 International Joint Conference on Neural Networks (IJCNN). IEEE, 2014. http://dx.doi.org/10.1109/ijcnn.2014.6889690.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Quan, Yu, Zhixin Li, Canlong Zhang y Huifang Ma. "Object Detection by Integrating Scene-Level Semantic Information and Border Regression Reinforcement". En 2020 International Joint Conference on Neural Networks (IJCNN). IEEE, 2020. http://dx.doi.org/10.1109/ijcnn48605.2020.9206636.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Liu, Tianying, Yang Wang, Siyun Hou, Wengen Li, Jihong Guan, Shuigeng Zhou y Rufu Qin. "RBA-CenterNet: Feature Enhancement by Rotated Border Alignment for Oriented Object Detection". En 2021 International Joint Conference on Neural Networks (IJCNN). IEEE, 2021. http://dx.doi.org/10.1109/ijcnn52387.2021.9534400.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Mishra, A., K. Sudan y H. Soliman. "Detecting border intrusion using wireless sensor network and artificial neural network". En 2010 International Conference on Distributed Computing in Sensor Systems Workshops (DCOSSW 2010). IEEE, 2010. http://dx.doi.org/10.1109/dcossw.2010.5593287.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Krigel, Tina, RA Benjamin Schitze y Jonathan Stoklas. "Legal, ethical and social impact on the use of computational intelligence based systems for land border crossings". En 2018 International Joint Conference on Neural Networks (IJCNN). IEEE, 2018. http://dx.doi.org/10.1109/ijcnn.2018.8489349.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Pawlicki, Marek, Rafał Kozik y Michał Choraś. "Improving Siamese Neural Networks with Border Extraction Sampling for the use in Real-Time Network Intrusion Detection". En 2023 International Joint Conference on Neural Networks (IJCNN). IEEE, 2023. http://dx.doi.org/10.1109/ijcnn54540.2023.10191496.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Ali, Abder-Rahman, Jingpeng Li, Sally Jane O'Shea, Guang Yang, Thomas Trappenberg y Xujiong Ye. "A Deep Learning Based Approach to Skin Lesion Border Extraction With a Novel Edge Detector in Dermoscopy Images". En 2019 International Joint Conference on Neural Networks (IJCNN). IEEE, 2019. http://dx.doi.org/10.1109/ijcnn.2019.8852134.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Okel, Sanne E., Fons van der Sommen, Endi Selmanaj, Joost A. van der Putten, Maarten R. Struyvenberg, Jacques J. Bergman y Peter H. N. de With. "Tissue-border detection in volumetric laser endomicroscopy using bi-directional gated recurrent neural networks". En Computer-Aided Diagnosis, editado por Karen Drukker y Maciej A. Mazurowski. SPIE, 2021. http://dx.doi.org/10.1117/12.2579751.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Informes sobre el tema "Neural border"

Willson. L51756 State of the Art Intelligent Control for Large Engines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), septiembre de 1996. http://dx.doi.org/10.55274/r0010423.

Texto completo

Resumen

Computers have become a vital part of the control of pipeline compressors and compressor stations. For many tasks, computers have helped to improve accuracy, reliability, and safety, and have reduced operating costs. Computers excel at repetitive, precise tasks that humans perform poorly - calculation, measurement, statistical analysis, control, etc. Computers are used to perform these type of precise tasks at compressor stations: engine / turbine speed control, ignition control, horsepower estimation, or control of complicated sequences of events during startup and/or shutdown. For other tasks, however, computers perform very poorly at tasks that humans find to be trivial. A discussion of the differences in the way humans and computer process information is crucial to an understanding of the field of artificial intelligence. In this project, several artificial intelligence/ intelligent control systems were examined: heuristic search techniques, adaptive control, expert systems, fuzzy logic, neural networks, and genetic algorithms. Of these, neural networks showed the most potential for use on large bore engines because of their ability to recognize patterns in incomplete, noisy data. Two sets of experimental tests were conducted to test the predictive capabilities of neural networks. The first involved predicting the ignition timing from combustion pressure histories; the best networks responded within a specified tolerance level 90% to 98.8% of the time. In the second experiment, neural networks were used to predict NOx, A/F ratio, and fuel consumption. NOx prediction accuracy was 91.4%, A/F ratio accuracy was 82.9%, and fuel consumption accuracy was 52.9%. This report documents the assessment of the state of the art of artificial intelligence for application to the monitoring and control of large-bore natural gas engines.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Olsen y Willson. L51916 Pressure Based Parametric Emission Monitoring Systems (PEMS). Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), abril de 2002. http://dx.doi.org/10.55274/r0010181.

Texto completo

Resumen

The natural gas industry operates over 8000 stationary large bore (bore greater than 14 in) natural gas engines for natural gas compression on pipelines and power generation. As emissions regulations become increasingly more stringent, the need for low cost methods for compliance demonstration arises. A PEMS model is one such approach. Research in this area has increased significantly during the last decade. PEMS models for this application utilize parameters commonly measured on industrial engines in the field to predict engine-out emissions. Monitoring emissions in this manner represents a significant cost savings over the periodic use of chemiluminescence NOX analyzers, which are not standard equipment in natural gas compressor stations. PEMS model accuracy is dependent on the quality of the input data, both the training NOX measurements and the selection of input parameters. Hence, it is important to have both reliable data measurement methods and an understanding of engine operating parameters relation to NOX. This work is part of the body of work referred to as the Integrated Test Plan (ITP), performed at the Engines and Energy Conversion Laboratory (EECL). This report details an investigation into Parametric Emissions Monitoring System (PEMS) models. It is the final document to be delivered under the ITP program. Much of the work performed under the ITP program focused on Hazardous Air Pollutants (HAPs) research. However, the emphasis of the PEMS work is on the prediction of oxides of nitrogen (NOX) emissions from large bore natural gas engines. In this work two different PEMS models are developed, a semi-empirical model and a neural network model. The semi-empirical model is based on general relationships between NOX emissions and engine parameters, but contains empirical constants that are determined based on the best fit to engine experimental data. The neural network model utilizes a similar set of input parameters, but relies on the neural network code to determine the relationships between input parameters and measured NOX emissions. The neural network model also contains empirical constants. The mathematics involved in both models is described. A single term semi-empirical model, which has been utilized in the literature as a PEMS model, is applied for comparative purposes.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Irudayaraj, Joseph, Ze'ev Schmilovitch, Amos Mizrach, Giora Kritzman y Chitrita DebRoy. Rapid detection of food borne pathogens and non-pathogens in fresh produce using FT-IRS and raman spectroscopy. United States Department of Agriculture, octubre de 2004. http://dx.doi.org/10.32747/2004.7587221.bard.

Texto completo

Resumen

Rapid detection of pathogens and hazardous elements in fresh fruits and vegetables after harvest requires the use of advanced sensor technology at each step in the farm-to-consumer or farm-to-processing sequence. Fourier-transform infrared (FTIR) spectroscopy and the complementary Raman spectroscopy, an advanced optical technique based on light scattering will be investigated for rapid and on-site assessment of produce safety. Paving the way toward the development of this innovative methodology, specific original objectives were to (1) identify and distinguish different serotypes of Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Bacillus cereus by FTIR and Raman spectroscopy, (2) develop spectroscopic fingerprint patterns and detection methodology for fungi such as Aspergillus, Rhizopus, Fusarium, and Penicillium (3) to validate a universal spectroscopic procedure to detect foodborne pathogens and non-pathogens in food systems. The original objectives proposed were very ambitious hence modifications were necessary to fit with the funding. Elaborate experiments were conducted for sensitivity, additionally, testing a wide range of pathogens (more than selected list proposed) was also necessary to demonstrate the robustness of the instruments, most crucially, algorithms for differentiating a specific organism of interest in mixed cultures was conceptualized and validated, and finally neural network and chemometric models were tested on a variety of applications. Food systems tested were apple juice and buffer systems. Pathogens tested include Enterococcus faecium, Salmonella enteritidis, Salmonella typhimurium, Bacillus cereus, Yersinia enterocolitis, Shigella boydii, Staphylococus aureus, Serratiamarcescens, Pseudomonas vulgaris, Vibrio cholerae, Hafniaalvei, Enterobacter cloacae, Enterobacter aerogenes, E. coli (O103, O55, O121, O30 and O26), Aspergillus niger (NRRL 326) and Fusarium verticilliodes (NRRL 13586), Saccharomyces cerevisiae (ATCC 24859), Lactobacillus casei (ATCC 11443), Erwinia carotovora pv. carotovora and Clavibacter michiganense. Sensitivity of the FTIR detection was 103CFU/ml and a clear differentiation was obtained between the different organisms both at the species as well as at the strain level for the tested pathogens. A very crucial step in the direction of analyzing mixed cultures was taken. The vector based algorithm was able to identify a target pathogen of interest in a mixture of up to three organisms. Efforts will be made to extend this to 10-12 key pathogens. The experience gained was very helpful in laying the foundations for extracting the true fingerprint of a specific pathogen irrespective of the background substrate. This is very crucial especially when experimenting with solid samples as well as complex food matrices. Spectroscopic techniques, especially FTIR and Raman methods are being pursued by agencies such as DARPA and Department of Defense to combat homeland security. Through the BARD US-3296-02 feasibility grant, the foundations for detection, sample handling, and the needed algorithms and models were developed. Successive efforts will be made in transferring the methodology to fruit surfaces and to other complex food matrices which can be accomplished with creative sampling methods and experimentation. Even a marginal success in this direction will result in a very significant breakthrough because FTIR and Raman methods, in spite of their limitations are still one of most rapid and nondestructive methods available. Continued interest and efforts in improving the components as well as the refinement of the procedures is bound to result in a significant breakthrough in sensor technology for food safety and biosecurity.

Los estilos APA, Harvard, Vancouver, ISO, etc.

UK, Ipsos. Survey of public attitudes towards precision breeding. Food Standards Agency, octubre de 2022. http://dx.doi.org/10.46756/sci.fsa.ouv127.

Texto completo

Resumen

The Genetic Technology (Precision Breeding) Bill is currently going through Parliament. Although this bill is ‘England only’ and food and feed safety and hygiene is a devolved issue, the Food Standards Agency (FSA) will introduce a separate regulatory framework for precision bred organisms (PBOs), should the Bill become law. The FSA will also work with stakeholders in Scotland, Wales and Northern Ireland to ensure consumers’ interests are protected in relation to PBOs. The FSA / Food Standard Scotland (FSS) is science and evidence led. In August 2022, the FSA and FSS commissioned Ipsos UK to conduct a two-phase social research project on precision breeding. Phase One, now complete, involved a survey of 4,177 UK residents with robust samples in each UK nation to allow comparisons between and within nations. Phase Two, scheduled to start in September 2022 and report in early 2023, will comprise a series of Citizens’ Forums in England, Wales and Northern Ireland(footnote 1). The overall aims of this project are to: explore consumer attitudes towards precision breeding gather consumer views on the FSA’s proposed regulatory framework understand consumer information needs inform how to communicate with consumers about precision breeding. This document presents interim findings for this project, reporting descriptive data from Phase One. Phase One’s core aims were to provide a snapshot of consumers’ awareness and self-assessed knowledge of precision breeding, its perceived acceptability, risks and benefits, and consumer appetite for information about this production method. These data show that awareness of precision breeding is very low, something which should be borne in mind when considering these findings. While these data reveal that there is a general openness to trying precision bred foods across the UK, with more people anticipating benefits than disbenefits from the use of precision breeding, there is a large degree of uncertainty about what impact precision bred foods may have on the different parts of the food system. This is reflected in the relatively large proportions of people taking a neutral stance or indicating they do not know enough to answer survey questions and in the strong appetite expressed for information about precision breeding to be provided. The next phase of this project will be essential for the FSA’s ability to interpret these findings’ implications, and to understand what is informing consumers’ views. The purpose of Phase One has always been to let the FSA know ‘what’ consumers think about precision breeding; Phase Two’s purpose is to build our understanding ‘why’ they think it. This will allow the FSA to develop a more nuanced understanding of consumers’ needs and incorporate this into the design of the future regulatory framework and any engagement with consumers on precision breeding. FSS will be carrying out further research in Scotland.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Ofrecemos descuentos en todos los planes premium para autores cuyas obras están incluidas en selecciones literarias temáticas. ¡Contáctenos para obtener un código promocional único!