A frequency-adjustable electromagnet for hyperthermia measurements on magnetic nanoparticles

We describe a low-cost and simple setup for hyperthermia measurements on colloidal solutions of magnetic nanoparticles (ferrofluids) with a frequency-adjustable magnetic field in the range 5-500 kHz produced by an electromagnet. By optimizing the general conception and each component (nature of the wires, design of the electromagnet), a highly efficient setup is obtained. For instance, in a useful gap of 1.1 cm, a magnetic field of 4.8 mT is generated at 100 kHz and 500 kHz with an output power of 3.4 W and 75 W, respectively. A maximum magnetic field of 30 mT is obtained at 100 kHz. The temperature of the colloidal solution is measured using optical fiber sensors. To remove contributions due to heating of the electromagnet, a differential measurement is used. In this configuration the sensitivity is better than 1.5 mW at 100 kHz and 19.3 mT. This setup allows one to measure weak heating powers on highly diluted colloidal solutions. The hyperthermia characteristics of a solution of Fe nanoparticles are described, where both the magnetic field and the frequency dependence of heating power have been measured

On Being Bound Thereby

Part of Symposium: The United States Constitution (rev. ed.) How would you rewrite the United States Constitution

Temporal Imperialism

Issues of time and temporality pervade American constitutional adjudication, at both a doctrinal and a broader, structural level. The doctrinal issue concerns the extent to which judicial decisions operate forward, backward, or some combination of both across time. The structural issue concerns the related and overarching question of how the Supreme Court, as a court, operates in time, and the temporal division of authority between courts and legislatures. In both contexts, the Supreme Court is an actor in time. This Article examines the Court’s treatment of temporal issues through three case studies: (1) a pair of early decisions in which the Court confronted both the transition from the colonial to the republican constitutional regime, and the temporal scope of legislative acts; (2) the Court’s twentieth-century doctrine on adjudicative retroactivity; and (3) the recent case of Grutter v. Bollinger, in which the Court’s temporal imperialism led it to claim ever-greater power to define the relevant timeframe for antidiscrimination law. The Court’s institutional self-presentation suggests that it is immortal and therefore not temporally bound, and that claim of continuity typically extends to its decisions. But the causal flow from institutional to doctrinal continuity sometimes breaks down. Perhaps not surprisingly, these moments of disjunction tend to arise when the Court chooses to allow them to. Even in situations that call into question the continuity of a particular doctrine, therefore, the Court remains master of time in that it as an institution determines when and how the façade of doctrinal continuity is to be breached

High Dimensional Classification with combined Adaptive Sparse PLS and Logistic Regression

Motivation: The high dimensionality of genomic data calls for the development of specific classification methodologies, especially to prevent over-optimistic predictions. This challenge can be tackled by compression and variable selection, which combined constitute a powerful framework for classification, as well as data visualization and interpretation. However, current proposed combinations lead to instable and non convergent methods due to inappropriate computational frameworks. We hereby propose a stable and convergent approach for classification in high dimensional based on sparse Partial Least Squares (sparse PLS). Results: We start by proposing a new solution for the sparse PLS problem that is based on proximal operators for the case of univariate responses. Then we develop an adaptive version of the sparse PLS for classification, which combines iterative optimization of logistic regression and sparse PLS to ensure convergence and stability. Our results are confirmed on synthetic and experimental data. In particular we show how crucial convergence and stability can be when cross-validation is involved for calibration purposes. Using gene expression data we explore the prediction of breast cancer relapse. We also propose a multicategorial version of our method on the prediction of cell-types based on single-cell expression data. Availability: Our approach is implemented in the plsgenomics R-package.Comment: 9 pages, 3 figures, 4 tables + Supplementary Materials 8 pages, 3 figures, 10 table

Quadruplexes In ‘Dicty’: Crystal Structure Of A Four-Quartet G-Quadruplex Formed By G-Rich Motif Found In The Dictyostelium Discoideum Genome

Guanine-rich DNA has the potential to fold into non-canonical G-quadruplex (G4) structures. Analysis of the genome of the social amoeba Dictyostelium discoideum indicates a low number of sequences with G4-forming potential (249–1055). Therefore, D. discoideum is a perfect model organism to investigate the relationship between the presence of G4s and their biological functions. As a first step in this investigation, we crystallized the dGGGGGAGGGGTACAGGGGTACAGGGG sequence from the putative promoter region of two divergent genes in D. discoideum. According to the crystal structure, this sequence folds into a four-quartet intramolecular antiparallel G4 with two lateral and one diagonal loops. The G-quadruplex core is further stabilized by a G-C Watson–Crick base pair and a A–T–A triad and displays high thermal stability (Tm \u3e 90°C at 100 mM KCl). Biophysical characterization of the native sequence and loop mutants suggests that the DNA adopts the same structure in solution and in crystalline form, and that loop interactions are important for the G4 stability but not for its folding. Four-tetrad G4 structures are sparse. Thus, our work advances understanding of the structural diversity of G-quadruplexes and yields coordinates for in silico drug screening programs and G4 predictive tools

Functional approach for pairing in finite systems: How to define restoration of broken symmetries in Energy Density Functional theory ?

The Multi-Reference Energy Density Functional (MR-EDF) approach (also called configuration mixing or Generator Coordinate Method), that is commonly used to treat pairing in finite nuclei and project onto particle number, is re-analyzed. It is shown that, under certain conditions, the MR-EDF energy can be interpreted as a functional of the one-body density matrix of the projected state with good particle number. Based on this observation, we propose a new approach, called Symmetry-Conserving EDF (SC-EDF), where the breaking and restoration of symmetry are accounted for simultaneously. We show, that such an approach is free from pathologies recently observed in MR-EDF and can be used with a large flexibility on the density dependence of the functional.Comment: proceeding of the conference "Many body correlations from dilute to dense Nuclear systems", Paris, February 201