Revisiting loop quantum gravity with selfdual variables: Classical theory

We review the classical formulation of general relativity as an SL(2,C) gauge theory in terms of Ashtekar's selfdual variables and reality conditions for the spatial metric (RCI) and its evolution (RCII), and we add some new observations and results. We first explain in detail how a connection taking values in the Lie algebra of the complex Lorentz group yields two Spin(3,1) connections, one selfdual and one anti-selfdual, without the need for a spin structure. We then demonstrate that the selfdual part of the complexified Palatini action in Ashtekar variables requires a holomorphic phase space description in order to obtain a non-degenerate symplectic structure. The holomorphic phase space does not allow for the implementation of the reality conditions as additional constraints, so they have to be taken care of "by hand" during the quantisation. We also observe that, due to the action being complex, there is an overall complex phase that can be chosen at will. We then review the canonical formulation and the consequences of the implementation of the reality conditions. We pay close attention to the transformation behaviour of the various fields under (complex) basis changes, as well as to complex analytic properties of the relevant functions on phase space.Comment: 40 page

Revisiting loop quantum gravity with selfdual variables: Hilbert space and first reality condition

We consider the quantization of gravity as an SL(2,C) gauge theory in terms of Ashtekar's selfdual variables and reality conditions for the spatial metric (RCI) and its evolution (RCII). We start from a holomorphic phase space formulation. It is then natural to push for a quantization in terms of holomorphic wave functions. Thus we consider holomorphic cylindrical wave functions over SL(2,C) connections. We use an overall phase ambiguity of the complex selfdual action to obtain Poisson brackets that mirror those of the real theory. We then show that there is a representation of the corresponding canonical commutation relations the space of holomorphic cylindrical functions. We describe a class of cylindrically consistent measures that implements RCI. We show that spin networks with SU(2) intertwiners form a basis for gauge invariant states. They are still mutually orthogonal, but the normalisation is different than for the Ashtekar-Lewandowski measure for SU(2). We do not consider RCII in the present article. Work on RCII is ongoing and will be presented elsewhere.Comment: 29 page

Silicon Oxycarbide Coatings Consisting of Defined Bottom–Up‐Grown Nanostructures

Silicon oxycarbide (SiOC) materials have arisen in the past few decades as a promising new class of glasses and glass-ceramics thanks to their advantageous chemical and thermal properties. Many applications, such as ion storage, sensing, filtering, or catalysis, require materials or coatings with high surface area and might benefit from the high thermal stability of SiOC. This work reports the first facile bottom–up approach to textured high surface area SiOC coatings obtained via direct pyrolysis of polysiloxane structures of well-defined shapes, such as nanofilaments or microrods. This work further investigates the thermal behavior of these structures by means of FT-IR, SEM, and EDX up to 1400 °C. The rods shrink in volume by ≈30% while their aspect ratio remains unaffected by pyrolysis until at least 1100 °C. The nano-sized filaments show signs of viscous flow already at a comparably low temperature of 900 °C which is very probably due to the nano-size effect. This might open a way to experimentally study the size-effect on the glass transition temperature of oxide glasses, an experimentally unexplored but very relevant topic. These structures have great potential, for example, as ion storage materials and supports in high temperature catalysis and CO2 conversion

Theory for nucleation at an interface and magnetization reversal of a two-layer nanowire

Nucleation at the interface between two adjoining regions with dissimilar physical properties is investigated using a model for magnetization reversal of a two-layer ferromagnetic nanowire. Each layer of the nanowire is considered to have a different degree of magnetic anisotropy, representing a hard magnetic layer exchange-coupled to a softer layer. A magnetic field applied along the easy axis causes the softer layer to reverse, forming a domain wall close to the interface. For small applied fields this state is metastable and complete reversal of the nanowire takes place via activation over a barrier. A reversal mechanism involving nucleation at an interface is proposed, whereby a domain wall changes in width as it passes from the soft layer to the hard layer during activation. Langer’s statistical theory for the decay of a metastable state is used to derive rates of magnetization reversal, and simple formulas are found in limiting cases for the activation energy, rate of reversal, and critical field at which the metastable state becomes unstable. These formulas depend on the anisotropy difference between each layer, and the behavior of the reversal rate prefactor is interpreted in terms of activation entropy and domain-wall dynamics

Rethinking the Core List of Journals for Libraries that Serve Schools and Colleges of Pharmacy.

The Core List of Journals for Libraries that Serve Schools and Colleges of Pharmacy is a guide for developing and maintaining pharmacy-affiliated library collections. A work group was created to update the list and design a process for updating that will streamline future revisions. Work group members searched the National Library of Medicine catalog for an initial list of journals and then applied inclusion criteria to narrow the list. The work group finalized the fifth edition of the list with 225 diverse publications and produced a sustainable set of criteria for journal inclusion, providing a structured, objective process for future updates

A Comprehensive Safety Trial of Chimeric Antibody 14.18 With GM-CSF, IL-2, and Isotretinoin in High-Risk Neuroblastoma Patients Following Myeloablative Therapy: Children\u27s Oncology Group Study ANBL0931

Purpose: A phase 3 randomized study (COG ANBL0032) demonstrated significantly improved outcome by adding immunotherapy with ch14.18 antibody to isotretinoin as post-consolidation therapy for high-risk neuroblastoma (NB). This study, ANBL0931, was designed to collect FDA-required safety/toxicity data to support FDA registration of ch14.18. Experimental design: Newly diagnosed high-risk NB patients who achieved at least a partial response to induction therapy and received myeloablative consolidation with stem cell rescue were enrolled to receive six courses of isotretinoin with five concomitant cycles of ch14.18 combined with GM-CSF or IL2. Ch14.18 infusion time was 10-20 h per dose. Blood was collected for cytokine analysis and its association with toxicities and outcome. Results: Of 105 patients enrolled, five patients developed protocol-defined unacceptable toxicities. The most common grade \u3e/= 3 non-hematologic toxicities of immunotherapy for cycles 1-5, respectively, were neuropathic pain (41, 28, 22, 31, 24%), hypotension (10, 17, 4, 14, 8%), allergic reactions (ARs) (3, 10, 5, 7, 2%), capillary leak syndrome (1, 4, 0, 2, 0%), and fever (21, 59, 6, 32, 5%). The 3-year event-free survival and overall survival were 67.6 +/- 4.8% and 79.1 +/- 4.2%, respectively. AR during course 1 was associated with elevated serum levels of IL-1Ra and IFNgamma, while severe hypotension during this course was associated with low IL5 and nitrate. Higher pretreatment CXCL9 level was associated with poorer event-free survival (EFS). Conclusion: This study has confirmed the significant, but manageable treatment-related toxicities of this immunotherapy and identified possible cytokine biomarkers associated with select toxicities and outcome. EFS and OS appear similar to that previously reported on ANBL0032