The Dwarfs Beyond: The Stellar-to-Halo Mass Relation for a New Sample of Intermediate Redshift Low Mass Galaxies

A number of recent challenges to the standard Lambda-CDM paradigm relate to discrepancies that arise in comparing the abundance and kinematics of local dwarf galaxies with the predictions of numerical simulations. Such arguments rely heavily on the assumption that the local dwarf and satellite galaxies form a representative distribution in terms of their stellar-to-halo mass ratios. To address this question, we present new, deep spectroscopy using DEIMOS on Keck for 82 low mass (10^7-10^9 solar masses) star-forming galaxies at intermediate redshift (z=0.2-1). For 50 percent of these we are able to determine resolved rotation curves using nebular emission lines and thereby construct the stellar mass Tully-Fisher relation to masses as low as 10^7 solar masses. Using scaling relations determined from weak lensing data, we convert this to a stellar-to-halo mass (SHM) relation for comparison with abundance matching predictions. We find a discrepancy between the propagated predictions from simulations compared to our observations, and suggest possible reasons for this as well as future tests that will be more effective.Comment: 11 pages, 7 figures, submitted to ApJ, comments welcom

A short note on the presence of spurious states in finite basis approximations

The genesis of spurious solutions in finite basis approximations to operators which possess a continuum and a point spectrum is discussed and a simple solution for identifying these solutions is suggested

Improving the Convergence of an Iterative Algorithm Proposed By Waxman

In the iterative algorithm recently proposed by Waxman for solving eigenvalue problems, we point out that the convergence rate may be improved. For many non-singular symmetric potentials which vanish asymptotically, a simple analytical relationship between the coupling constant of the potential and the ground state eigenvalue is obtained which can be used to make the algorithm more efficient

A Dialogue of Forms: The Display of Thinking in George Eliot’s ‘Poetry and Prose, From the Notebook of an Eccentric’ and Impressions of Theophrastus Such

This article rereads George Eliot's Impressions of Theophrastus Such in the light of her early series of journalism “Poetry and Prose, from the Notebook of an Eccentric.” Rather than viewing these texts as experimental deviations, this article casts these texts as part of larger patterns evident in Eliot's canon as a whole. Building on recent studies on Eliot and Victorian perfectionism, it argues that Eliot united an appreciation for complex and diverse configurations of form with her interest in individual development and the extension of sympathy. In these texts, we can see a reflection of Eliot's interest in the attempt to capture and display human thinking processes in order to advance her project of extending the sympathies of her readership. It examines Eliot's organicist views on form and consciousness and suggests that these are key to making sense of the apparently “aberrant” nature of these texts. Eliot, influenced by Ludwig Feuerbach, held to the idea that just as the highest form of organicism was the most complex, so also was the highest form of art the most structurally varied and intricate. From this viewpoint, the texts are eminently successful. Moreover, they point the way to achieving a fuller understanding of the apparent problematics of form that have concerned critics in regard to Eliot's better-known fictional works since their original publication

miR-34a-/- mice are susceptible to diet-induced obesity

Objective: MicroRNA (miR)−34a regulates inflammatory pathways, and increased transcripts have been observed in serum and subcutaneous adipose of subjects who have obesity and type 2 diabetes. Therefore, the role of miR-34a in adipose tissue inflammation and lipid metabolism in murine diet-induced obesity was investigated. Methods: Wild-type (WT) and miR-34a−/− mice were fed chow or high-fat diet (HFD) for 24 weeks. WT and miR-34a−/− bone marrow-derived macrophages were cultured in vitro with macrophage colony-stimulating factor (M-CSF). Brown and white preadipocytes were cultured from the stromal vascular fraction (SVF) of intrascapular brown and epididymal white adipose tissue (eWAT), with rosiglitazone. Results: HFD-fed miR-34a−/− mice were significantly heavier with a greater increase in eWAT weight than WT. miR-34a−/− eWAT had a smaller adipocyte area, which significantly increased with HFD. miR-34a−/− eWAT showed basal increases in Cd36, Hmgcr, Lxrα, Pgc1α, and Fasn. miR-34a−/− intrascapular brown adipose tissue had basal reductions in c/ebpα and c/ebpβ, with in vitro miR-34a−/− white adipocytes showing increased lipid content. An F4/80high macrophage population was present in HFD miR-34a−/− eWAT, with increased IL-10 transcripts and serum IL-5 protein. Finally, miR-34a−/− bone marrow-derived macrophages showed an ablated CXCL1 response to tumor necrosis factor-α. Conclusions: These findings suggest a multifactorial role of miR-34a in controlling susceptibility to obesity, by regulating inflammatory and metabolic pathways

On the Absence of Spurious Eigenstates in an Iterative Algorithm Proposed By Waxman

We discuss a remarkable property of an iterative algorithm for eigenvalue problems recently advanced by Waxman that constitutes a clear advantage over other iterative procedures. In quantum mechanics, as well as in other fields, it is often necessary to deal with operators exhibiting both a continuum and a discrete spectrum. For this kind of operators, the problem of identifying spurious eigenpairs which appear in iterative algorithms like the Lanczos algorithm does not occur in the algorithm proposed by Waxman

A Modified Version of the Waxman Algorithm

The iterative algorithm recently proposed by Waxman for solving eigenvalue problems, which relies on the method of moments, has been modified to improve its convergence considerably without sacrificing its benefits or elegance. The suggested modification is based on methods to calculate low-lying eigenpairs of large bounded hermitian operators or matrices