Title: Input convex neural networks

Abstract:

This paper presents the input convex neural network architecture. These are scalar-valued (potentially deep) neural networks with constraints on the network parameters such that the output of the network is a convex function of (some of) the inputs. The networks allow for efficient inference via optimization over some inputs to the network given others, and can be applied to settings including structured prediction, data imputation, reinforcement learning, and others. In this paper we lay the basic groundwork for these models, proposing methods for inference, optimization and learning, and analyze their representational power. We show that many existing neural network architectures can be made input-convex with a minor modification, and develop specialized optimization algorithms tailored to this setting. Finally, we highlight the performance of the methods on multi-label prediction, image completion, and reinforcement learning problems, where we show improvement over the existing state of the art in many cases.

Biography:

Born in Nantong, Jiangsu, in 1963 Xu Lei studied ink painting at the Department of Fine Arts of Nanjing Art Academy and used to be a professional painter affiliated with the Jiangsu Institute of Chinese Painting. ... Xu was an active participant in the innovative art movements in China in the late 1980's.

Title: Integration of gold nanoparticles in PDMS microfluidics for lab-on-a-chip plasmonic biosensing of growth hormones

Abstract:

Gold nanoparticles were synthesized in a poly (dimethylsiloxane)(PDMS) microfluidic chip by using an in-situ method, on the basis of reductive properties of the cross-linking agent of PDMS. The proposed integrated device was further used as a sensitive and low-cost LSPR-based biosensor for the detection of polypeptides. Synthesis of nanoparticles in the microfluidic environment resulted in improvement of size distribution with only 8% variation, compared with the macro-environment that yields about 67% variation in size. The chemical kinetics of the in-situ reaction in the microfluidic environment was studied in detail and compared with the reaction carried out at the macro-scale. The effect of temperature and gold precursor concentration on the kinetics of the reaction was investigated and the apparent activation energy was estimated to be E a⁎= 30 kJ/mol. 

Biography:

Hamid Sadabadi is an entrepreneur and researcher in the field of Microfluidics, Lab-on-a-chip and sensors/biosensors. He has completed his PhD in microfluidic from Concordia University in Montreal. ... He is the currently CTO of Wireless Fluidics, a sensing technology development start-up.

Title: Electronic detection of specific protein binding using nanotube FET devices

Abstract:

We have used nanoscale field effect transistor devices with carbon nanotubes as the conducting channel to detect protein binding. A PEI/PEG polymer coating layer has been employed to avoid nonspecific binding, with attachment of biotin to the layer for specific molecular recognition. Biotin-streptavidin binding has been detected by changes in the device characteristic. Nonspecific binding was observed in devices without the polymer coating, while no binding was found for polymer-coated but not biotinylated devices. Streptavidin, in which the biotin-binding sites were blocked by reaction with excess biotin, produced essentially no change in device characteristic of the biotinylated polymer-coated devices.

Biography:

Dr Jean-Christophe P. Gabriel is one of CEA’s Research Director, the highest research position in CEA, in the field of Nanoscience. He is also currently a visiting Professor at NTU where he serves as co-director of the NTU Singapore CEA Alliance for Research in Circular Economy (SCARCE). He first joined the French Alternative Energy and Atomic Energy Commission (CEA) in 2007. There, he was CEA/LETI institute’s “Beyond CMOS” program manager as well as the business director of the academic- industry Caltech – LETI alliance, which led to the creation of the Startup Apix Technology (apixanalytics.com). From 2009 to 2016, he became deputy director of CEA’s Nanoscience program (budget: 1 M€/year). In parallel, from 2013 to 2018, he was co-principal investigator of the REE-CYCLE advanced ERC project (2013-2018), that aimed at developing new rare earth extraction/recycling processes, at least 10 times more efficient that current liquid-liquid extraction processes. In this REE-CYCLE laboratory in Grenoble, created in 2014, he was developing integrated microfluidic lab-on-chip that enable much faster exploration of multidimensional phase diagrams of complex fluids. Such lab-on-chip devices integrate various sensors as well as characterizations methods (such as FTIR in hollow waveguides, or Xray fluorescence).

Former student at the “Ecole Normale Supérieure” in Paris, he received his Ph. D. from Orsay’s University and his Habilitation from Joseph Fourier’s University in Grenoble. His career is a mixed academic – industrial one. He indeed started his career at CNRS (4 years at Jean Rouxel Institute, IMN, Nantes) followed by 6 years in the Californian startup Nanomix (nano.com) where he was one of the first employee. In this Berkeley spinoff he helped in the technology transfer of nanomaterials and carbon nanotubes technologies, helped raised $34 million of venture capital money and with his team was the first to put an integrated nanotube based electronic device on the market (a hydrogen sensor, in 2005).

Dr Jean-Christophe has published more than 60 papers in international peer reviewed journal and is co-inventor on more than 50 patents and patent applications, many of them dealing with nanomaterials, carbon nanotubes and graphene (~8400 citations). 

Title: Nano-FTIR absorption spectroscopy of molecular fingerprints at 20 nm spatial resolution

Abstract:

We demonstrate Fourier transform infrared nanospectroscopy (nano-FTIR) based on a scattering-type scanning near-field optical microscope (s-SNOM) equipped with a coherent-continuum infrared light source. We show that the method can straightforwardly determine the infrared absorption spectrum of organic samples with a spatial resolution of 20 nm, corresponding to a probed volume as small as 10 zeptoliter (10^–20 L). Corroborated by theory, the nano-FTIR absorption spectra correlate well with conventional FTIR absorption spectra, as experimentally demonstrated with poly(methyl methacrylate) (PMMA) samples. Nano-FTIR can thus make use of standard infrared databases of molecular vibrations to identify organic materials in ultrasmall quantities and at ultrahigh spatial resolution. As an application example we demonstrate the identification of a nanoscale PDMS contamination on a PMMA sample.

Biography:

Dr. Alexander Govyadinov has over 30 years of experience in various sensing platform development in academic and R&D industrial environments. Recent 14 years Alex works for Hewlett-Packard Printing, and after The Company split for HP Inc. in the Advanced Technology and Product Development Organization developing novel sensing and microfluidic solutions for inkjet applications. He is co-author of more than 100 publications and over 80 US Patents and patent applications.

Title: Defining the role of solid stress and matrix stiffness in cancer cell proliferation and metastasis

Abstract:

Solid tumors are characterized by an abnormal stroma that contributes to the development of biomechanical abnormalities in the tumor microenvironment. In particular, these abnormalities include an increase in matrix stiffness and an accumulation of solid stress in the tumor interior. So far, it is not clearly defined whether matrix stiffness and solid stress are strongly related to each other or they have distinct roles in tumor progression. Moreover, while the effects of stiffness on tumor progression are extensively studied compared to the contribution of solid stress, it is important to ascertain the biological outcomes of both abnormalities in tumorigenesis and metastasis. In this review, we discuss how each of these parameters is evolved during tumor growth and how are influenced by each other. We further review the effects of matrix stiffness and solid stress on the proliferative and metastatic potential of cancer and stromal cells, and summarize the in vitro experimental setups that have been designed to study the individual contribution of these parameters.

Biography:

Maria Kalli is a 2nd year PhD candidate, focusing on the effect of surfactants in microfluidic devices. She has been a long term UCL lover as she graduated with a first in MEng Chemical Engineering in 2018. She is a foodie (since day 1) and loves playing and listening to good music at gigs/concerts.