5,629 research outputs found
Distributed Lagrangian Methods for Network Resource Allocation
Motivated by a variety of applications in control engineering and information
sciences, we study network resource allocation problems where the goal is to
optimally allocate a fixed amount of resource over a network of nodes. In these
problems, due to the large scale of the network and complicated
inter-connections between nodes, any solution must be implemented in parallel
and based only on local data resulting in a need for distributed algorithms. In
this paper, we propose a novel distributed Lagrangian method, which requires
only local computation and communication. Our focus is to understand the
performance of this algorithm on the underlying network topology. Specifically,
we obtain an upper bound on the rate of convergence of the algorithm as a
function of the size and the topology of the underlying network. The
effectiveness and applicability of the proposed method is demonstrated by its
use in solving the important economic dispatch problem in power systems,
specifically on the benchmark IEEE-14 and IEEE-118 bus systems
On the convergence rate of distributed gradient methods for finite-sum optimization under communication delays
Motivated by applications in machine learning and statistics, we study
distributed optimization problems over a network of processors, where the goal
is to optimize a global objective composed of a sum of local functions. In
these problems, due to the large scale of the data sets, the data and
computation must be distributed over processors resulting in the need for
distributed algorithms. In this paper, we consider a popular distributed
gradient-based consensus algorithm, which only requires local computation and
communication. An important problem in this area is to analyze the convergence
rate of such algorithms in the presence of communication delays that are
inevitable in distributed systems. We prove the convergence of the
gradient-based consensus algorithm in the presence of uniform, but possibly
arbitrarily large, communication delays between the processors. Moreover, we
obtain an upper bound on the rate of convergence of the algorithm as a function
of the network size, topology, and the inter-processor communication delays
Study of process variables associated with manufacturing hermetically sealed nickel-cadmium cells
Formation time, specific gravity of solution, and overcharge amount associated with electrochemical cleaning or formation operation in manufacturing nickel cadmium cell
The transcriptional repressor protein growth factor independence-1B in T lymphopoiesis.
T lymphopoiesis has been an intense focus of immunological research since the discovery of the major histocompatibility complex (MHC) and T cell mediated transplant rejection. Additionally, researchers have long appreciated the role of T cells, and their development, in autoimmune disorders. Interest in this field has increased upon the realization that many leukemic oncoproteins are the very factors that control normal T cell development. Thus, the transcriptional networks that drive the function and development of T lymphocytes are closely linked with disease states.Growth Factor Independence 1 (GFI1) and GFI1B are two very similar transcriptional repressor oncoproteins that are encoded by two different genes. Though nearly identical in their DNA binding and repressor domains, GFI1 and GFI1B are differentially expressed in normal tissues and in tumors of lymphoid lineage. GFI1 is frequently activated in mouse T cell leukemias, whereas GFI1B has not been found in T cell tumors. The work described in this dissertation provides insight into this phenomenon by delineating functional differences for GFI1 and GFI1B in T cells.The first set of experiments compares the phenotypes engendered by transgenic expression of either GFI1 or GFI1B in developing and mature T lymphocytes. These analyses revealed that GFI1 enhances the response to T cell activation, whereas GFI1B decreases this response. Furthermore, transgenic GFI1B causes defects in thymocyte development, some of which result from a lack of survival signals. These defects can be corrected by transgenic expression of either BCL2, an inhibitor of apoptosis, or GFI1, suggesting that GFI1 and GFI1B play opposing roles in T cell survival.At least part of the effect of transgenic GFI1B results from GFI1B-mediated repression of Gfi1 transcription. We show that the transcription of Gfi1 is repressed in T cells by both GFI1 and GFI1B and that this is the result of direct binding to evolutionarily conserved GFI1/GFI1B recognition sequences in the Gfi1 promoter. Furthermore, we provide evidence that endogenous GFI1 regulates its own promoter in T cells, but not in a myeloid lineage cell line.Finally, a more detailed analysis of the effect of GFI1B in T lymphopoiesis confirms a role for GFI1B in the survival and differentiation of thymocytes. This analysis revealed that transgenic expression of GFI1B results in altered expression of several members of T cell receptor (TCR) signaling pathways that are largely responsible for the survival and differentiation of thymocytes. The activity of the downstream effectors of these pathways appears to be decreased, providing mechanistic insight in to the function of GFI1B in T cells.Our work is the first to describe a role for GFIB in T cells. We demonstrate that GFI1B negatively regulates the cellular response to activation through the TCR complex and provide preliminary evidence of a mechanism by which GFI1B mediates these effects. Furthermore, we delineate functional differences for GFI1 and GFI1B in T cells, providing insight into the differential expression of these two transcription factors
Interpersonal emotion regulation: a review of social and developmental components
A staple theme in clinical psychology, emotion regulation, or the ability to manage one's emotions, is directly linked with personal wellbeing and the ability to effectively navigate the social world. Until recently, this concept has been limited to a focus on intrapersonal processes, such as suppression. Less emphasis has been placed on developmental, social, and cultural aspects of emotion regulation. We argue here that as social beings, our engagement in emotion regulation may often occur interpersonally, with trusted others helping us to regulate our emotions. This review will highlight recent research on interpersonal emotion regulation processes.Dr Hofmann receives financial support from the Alexander von Humboldt Foundation (as part of the Humboldt Prize), NIH/NCCIH (R01AT007257), NIH/NIMH (R01MH099021, U01MH108168), and the James S. McDonnell Foundation 21st Century Science Initiative in Understanding Human Cognition - Special Initiative. He receives compensation for his work as an advisor from the Palo Alto Health Sciences and for his work as a Subject Matter Expert from John Wiley & Sons, Inc. and SilverCloud Health, Inc. He also receives royalties and payments for his editorial work from various publishers. (Alexander von Humboldt Foundation; R01AT007257 - NIH/NCCIH; R01MH099021 - NIH/NIMH; U01MH108168 - NIH/NIMH; James S. McDonnell Foundation 21st Century Science Initiative in Understanding Human Cognition - Special Initiative)Accepted manuscrip
Re-Orienting Planning Practice
This commentary reflects on the articles in the thematic issue on queering urban planning and municipal governance and the ways that they suggest that planning practice must be re-oriented to be more inclusive and incorporate more insurgent perspectives. Planning practice is susceptible to capture by neo-liberal corporate interests that marginalize vulnerable queer populations. More insurgent planning approaches are needed to resist the corporate take-over of queer spaces by empowering the voices of LGBTQ+ people
Low-Energy Polymeric Phases of Alanates
Low-energy structures of alanates are currently known to be described by
patterns of isolated, nearly ideal tetrahedral [AlH] anions and metal
cations. We discover that the novel polymeric motif recently proposed for
LiAlH plays a dominant role in a series of alanates, including LiAlH,
NaAlH, KAlH, Mg(AlH), Ca(AlH) and Sr(AlH). In
particular, most of the low-energy structures discovered for the whole series
are characterized by networks of corner-sharing [AlH] octahedra, forming
wires and/or planes throughout the materials. Finally, for Mg(AlH) and
Sr(AlH), we identify two polymeric phases to be lowest in energy at low
temperatures.Comment: 9 pages, 8 figures, 2 tables, including supplemental materia
NORTH AMERICAN INTEGRATION IN AGRICULTURE: A SURVEY PAPER
This paper surveys the economic literature about North American integration in the agri-food sector. The purpose of this survey is two-fold: it summarizes the lessons learned, and it identifies areas where further research could provide valuable input into policy discussions. As the integration of North American agriculture progresses, the range of agri-food policies with strictly domestic effects becomes increasingly narrow. Thus, policymakers in North America need to consider the effects that their decisions will have on other NAFTA countries, as well as the impact that decisions by other NAFTA governments will have at home. The paper is organized as follows. Section 2 identifies the major factors contributing to integration and comments on their relative importance. Section 3 summarizes research into the indicators of integration. These studies focus on price co-movements and trade flow data. Section 4 outlines the state of current knowledge regarding foreign direct investment in the agri-food sector, while Section 5 assesses the impact of integration on the structure and performance of the sector. Section 6 discusses opportunities for further integration in the sector, and Section 7 concludes the paper. Throughout the paper, gaps in the knowledge base are highlighted, along with suggested areas for further research.Industrial Organization,
First-principles predicted low-energy structures of NaSc(BH4)4
According to previous interpretations of experimental data, sodium-scandium
double-cation borohydride NaSc(BH) crystallizes in the crystallographic
space group where each sodium (scandium) atom is surrounded by six
scandium (sodium) atoms. A careful investigation of this phase based on
\textit{ab initio} calculations indicates that the structure is dynamically
unstable and gives rise to an energetically and dynamically more favorable
phase with symmetry and nearly identical x-ray diffraction pattern. By
additionally performing extensive structural searches with the minima-hopping
method we discover a class of new low-energy structures exhibiting a novel
structural motif in which each sodium (scandium) atom is surrounded by four
scandium (sodium) atoms arranged at the corners of either a rectangle with
nearly equal sides or a tetrahedron. These new phases are all predicted to be
insulators with band gaps of eV. Finally, we estimate the influence
of these structures on the hydrogen-storage performance of NaSc(BH).Comment: Version publishe
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