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  1. Artikel ; Online: Extending the capabilities of vectorial ptychography to circular-polarizing materials such as cholesteric liquid crystals.

    Ferrand, Patrick / Mitov, Michel

    Optics letters

    2023  Band 48, Heft 19, Seite(n) 5081–5084

    Abstract: The problem of imaging materials with circular-polarization properties is discussed within the framework of vectorial ptychography. We demonstrate, both theoretically and numerically, that using linear polarizations to investigate such materials ... ...

    Abstract The problem of imaging materials with circular-polarization properties is discussed within the framework of vectorial ptychography. We demonstrate, both theoretically and numerically, that using linear polarizations to investigate such materials compromises the unicity of the solution provided by this computational method. To overcome this limitation, an improved measurement approach is proposed, which involves specific combinations of elliptical polarizations. The effectiveness of this strategy is demonstrated by numerical simulations and experimental measurements on cholesteric liquid crystal films, which possess unique polarization properties. With the help of Pauli matrices algebra, our results highlight the technique's ability to discern between the different types of circular polarizers, uniform vs. non-uniform, and determine their handedness.
    Sprache Englisch
    Erscheinungsdatum 2023-09-29
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 1539-4794
    ISSN (online) 1539-4794
    DOI 10.1364/OL.498655
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  2. Artikel ; Online: Reference-free quantitative microscopic imaging of coherent arbitrary vectorial light beams.

    Baroni, Arthur / Ferrand, Patrick

    Optics express

    2020  Band 28, Heft 23, Seite(n) 35339–35349

    Abstract: Precise spatial characterization of vectorial beams is crucial for many advanced optical experiments, but challenging when wavefront and polarization features are involved together. Here we propose a reference-free method aimed at extracting the map of ... ...

    Abstract Precise spatial characterization of vectorial beams is crucial for many advanced optical experiments, but challenging when wavefront and polarization features are involved together. Here we propose a reference-free method aimed at extracting the map of the complex-amplitude components of any coherent beam at an optical-microscopy resolution. Our method exploits recent advances in ptychographic imaging approaches. We emphasize its versatility by reconstructing successfully various experimental vectorial beams including polarization and phase vortices, the exit field of a multicore fiber and a speckle pattern.
    Sprache Englisch
    Erscheinungsdatum 2020-11-10
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ZDB-ID 1491859-6
    ISSN 1094-4087 ; 1094-4087
    ISSN (online) 1094-4087
    ISSN 1094-4087
    DOI 10.1364/OE.408665
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  3. Buch ; Online: The Efficacy of Transformer-based Adversarial Attacks in Security Domains

    Li, Kunyang / Domico, Kyle / Ferrand, Jean-Charles Noirot / McDaniel, Patrick

    2023  

    Abstract: Today, the security of many domains rely on the use of Machine Learning to detect threats, identify vulnerabilities, and safeguard systems from attacks. Recently, transformer architectures have improved the state-of-the-art performance on a wide range of ...

    Abstract Today, the security of many domains rely on the use of Machine Learning to detect threats, identify vulnerabilities, and safeguard systems from attacks. Recently, transformer architectures have improved the state-of-the-art performance on a wide range of tasks such as malware detection and network intrusion detection. But, before abandoning current approaches to transformers, it is crucial to understand their properties and implications on cybersecurity applications. In this paper, we evaluate the robustness of transformers to adversarial samples for system defenders (i.e., resiliency to adversarial perturbations generated on different types of architectures) and their adversarial strength for system attackers (i.e., transferability of adversarial samples generated by transformers to other target models). To that effect, we first fine-tune a set of pre-trained transformer, Convolutional Neural Network (CNN), and hybrid (an ensemble of transformer and CNN) models to solve different downstream image-based tasks. Then, we use an attack algorithm to craft 19,367 adversarial examples on each model for each task. The transferability of these adversarial examples is measured by evaluating each set on other models to determine which models offer more adversarial strength, and consequently, more robustness against these attacks. We find that the adversarial examples crafted on transformers offer the highest transferability rate (i.e., 25.7% higher than the average) onto other models. Similarly, adversarial examples crafted on other models have the lowest rate of transferability (i.e., 56.7% lower than the average) onto transformers. Our work emphasizes the importance of studying transformer architectures for attacking and defending models in security domains, and suggests using them as the primary architecture in transfer attack settings.

    Comment: Accepted to IEEE Military Communications Conference (MILCOM), AI for Cyber Workshop, 2023
    Schlagwörter Computer Science - Cryptography and Security ; Computer Science - Artificial Intelligence
    Thema/Rubrik (Code) 006
    Erscheinungsdatum 2023-10-17
    Erscheinungsland us
    Dokumenttyp Buch ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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  4. Artikel ; Online: PARP Inhibitor Inhibits the Vasculogenic Mimicry through a NF-κB-PTX3 Axis Signaling in Breast Cancer Cells.

    Chivot, Justine / Ferrand, Nathalie / Fert, Aude / Van Dreden, Patrick / Morichon, Romain / Sabbah, Michèle

    International journal of molecular sciences

    2022  Band 23, Heft 24

    Abstract: Poly (ADP-ribose) polymerase inhibitors (PARPi) are targeted therapies that inhibit PARP proteins which are involved in a variety of cell functions. PARPi may act as modulators of angiogenesis; however, the relationship between PARPi and the vasculogenic ...

    Abstract Poly (ADP-ribose) polymerase inhibitors (PARPi) are targeted therapies that inhibit PARP proteins which are involved in a variety of cell functions. PARPi may act as modulators of angiogenesis; however, the relationship between PARPi and the vasculogenic mimicry (VM) in breast cancer remains unclear. To determine whether PARPi regulate the vascular channel formation, we assessed whether the treatment with olaparib, talazoparib and veliparib inhibits the vascular channel formation by breast cancer cell lines. Here, we found that PARPi act as potent inhibitors of the VM formation in triple negative breast cancer cells, independently of the BRCA status. Mechanistically, we find that PARPi trigger and inhibit the NF-κB signaling, leading to the inhibition of the VM. We further show that PARPi decrease the expression of the angiogenic factor PTX3. Moreover, PTX3 rescued the PARPi-inhibited VM inhibition. In conclusion, our results indicate that PARPi, by targeting the VM, may provide a new therapeutic approach for triple negative breast cancer.
    Sprache Englisch
    Erscheinungsdatum 2022-12-18
    Erscheinungsland Switzerland
    Dokumenttyp Journal Article
    ZDB-ID 2019364-6
    ISSN 1422-0067 ; 1422-0067 ; 1661-6596
    ISSN (online) 1422-0067
    ISSN 1422-0067 ; 1661-6596
    DOI 10.3390/ijms232416171
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  5. Konferenzbeitrag ; Online: Quantitative phase microscopy for anisotropic materials

    Baroni, Arthur / Chamard, Virginie / Ferrand, Patrick

    Focus On Microscopy 2020 (FOM 2020) (Canceled Covid-19) ; https://hal-amu.archives-ouvertes.fr/hal-02537377 ; Focus On Microscopy 2020 (FOM 2020) (Canceled Covid-19), Apr 2020, Osaka, Japan ; http://www.focusonmicroscopy.org

    Structural imaging of biominerals

    2020  

    Abstract: International ... ...

    Abstract International audience
    Schlagwörter [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ; covid19
    Sprache Englisch
    Erscheinungsdatum 2020-04-05
    Verlag HAL CCSD
    Erscheinungsland fr
    Dokumenttyp Konferenzbeitrag ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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  6. Konferenzbeitrag ; Online: Three-dimensional imaging of arbitrary orbital angular momentum polarized fields by vectorial ptychography

    Baroni, Arthur / Chamard, Virginie / Ferrand, Patrick

    Focus On Microscopy 2020 (FOM 2020) (Canceled Covid-19) ; https://hal-amu.archives-ouvertes.fr/hal-02537376 ; Focus On Microscopy 2020 (FOM 2020) (Canceled Covid-19), Apr 2020, Osaka, Japan ; http://www.focusonmicroscopy.org

    2020  

    Abstract: International ... ...

    Abstract International audience
    Schlagwörter [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ; covid19
    Sprache Englisch
    Erscheinungsdatum 2020-04-05
    Verlag HAL CCSD
    Erscheinungsland fr
    Dokumenttyp Konferenzbeitrag ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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  7. Konferenzbeitrag ; Online: Three-dimensional imaging of arbitrary orbital angular momentum polarized fields by vectorial ptychography

    Baroni, Arthur / Chamard, Virginie / Ferrand, Patrick

    Focus On Microscopy 2020 (FOM 2020) (Canceled Covid-19) ; https://hal-amu.archives-ouvertes.fr/hal-02537376 ; Focus On Microscopy 2020 (FOM 2020) (Canceled Covid-19), Apr 2020, Osaka, Japan ; http://www.focusonmicroscopy.org

    2020  

    Abstract: International ... ...

    Abstract International audience
    Schlagwörter [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ; covid19
    Sprache Englisch
    Erscheinungsdatum 2020-04-05
    Verlag HAL CCSD
    Erscheinungsland fr
    Dokumenttyp Konferenzbeitrag ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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  8. Konferenzbeitrag ; Online: Quantitative phase microscopy for anisotropic materials

    Baroni, Arthur / Chamard, Virginie / Ferrand, Patrick

    Focus On Microscopy 2020 (FOM 2020) (Canceled Covid-19) ; https://hal-amu.archives-ouvertes.fr/hal-02537377 ; Focus On Microscopy 2020 (FOM 2020) (Canceled Covid-19), Apr 2020, Osaka, Japan ; http://www.focusonmicroscopy.org

    Structural imaging of biominerals

    2020  

    Abstract: International ... ...

    Abstract International audience
    Schlagwörter [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ; covid19
    Sprache Englisch
    Erscheinungsdatum 2020-04-05
    Verlag HAL CCSD
    Erscheinungsland fr
    Dokumenttyp Konferenzbeitrag ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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  9. Artikel ; Online: Quantitative imaging of anisotropic material properties with vectorial ptychography.

    Ferrand, Patrick / Baroni, Arthur / Allain, Marc / Chamard, Virginie

    Optics letters

    2018  Band 43, Heft 4, Seite(n) 763–766

    Abstract: Following the recent establishment of the formalism of vectorial ptychography [Opt. Lett.40, 5144 (2015)OPLEDP0146-959210.1364/OL.40.005144], first measurements, to the best of our knowledge, are reported in the optical range, demonstrating the ... ...

    Abstract Following the recent establishment of the formalism of vectorial ptychography [Opt. Lett.40, 5144 (2015)OPLEDP0146-959210.1364/OL.40.005144], first measurements, to the best of our knowledge, are reported in the optical range, demonstrating the capability of the proposed method to map the four parameters of the Jones matrix of an anisotropic specimen, and therefore to quantify a wide range of optical material properties, including power transmittance, optical path difference, diattenuation, retardance, and fast-axis orientation.
    Sprache Englisch
    Erscheinungsdatum 2018-02-15
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 1539-4794
    ISSN (online) 1539-4794
    DOI 10.1364/OL.43.000763
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  10. Artikel ; Online: La pauvreté en rural ; quels acteurs, quelles actions pour quels projets ?L’exemple de la région Auvergne-Rhône-Alpes

    Claire Delfosse / Mathilde Ferrand / Geneviève Ganivet / Patrick Grimault

    Bulletin de l’Association de Géographes Français, Vol 96, Iss 4, Pp 688-

    2019  Band 711

    Abstract: Concerns about poverty and precariousness phenomena in rural areas are being increasingly recognized ... nevertheless, the heterogeneity among rural areas constitutes an obstacle for taking care of them. And yet, some difficulties are specifically rurality- ...

    Abstract Concerns about poverty and precariousness phenomena in rural areas are being increasingly recognized

    nevertheless, the heterogeneity among rural areas constitutes an obstacle for taking care of them. And yet, some difficulties are specifically rurality-related matters. Deterioration of travel conditions reinforce the difficulties and limit access to basic human rights. Access to affordable housing and a strong inter-knowledge are additionnal factors compelling us to reconsider the best way to intervene in rural areas. Regarding poverty as well as the complexity of the forms it can take, actions aimed at improving the situation of people in precarious situations are diverse and mobilise a wide range of stakeholders in various fields with their very own scope of intervention. In order to adapt more efficiently to the specific features of their regions, stakeholders dealing with these issues are testing more territorialised and collaborative actions, often at the scale of inter-municipal associations. Innovative approaches are emerging. Although some territories and measures embed the fight against poverty within local projects and community development, these actions remain minimal.
    Schlagwörter Rural poverty ; Social action ; Territorialization ; Local development ; Geography (General) ; G1-922
    Thema/Rubrik (Code) 910
    Sprache Englisch
    Erscheinungsdatum 2019-12-01T00:00:00Z
    Verlag Association AGF
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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