5,905 research outputs found
Matter Wave Scattering from Ultracold Atoms in an Optical Lattice
We study matter wave scattering from an ultracold, many body atomic system
trapped in an optical lattice. We determine the angular cross section that a
matter wave probe sees and show that it is strongly affected by the many body
phase, superfluid or Mott insulator, of the target lattice. We determine these
cross sections analytically in the first Born approximation, and we examine the
variation at intermediate points in the phase transition by numerically
diagonalizing the Bose Hubbard Hamiltonian for a small lattice. We show that
matter wave scattering offers a convenient method for non-destructively probing
the quantum many body phase transition of atoms in an optical lattice.Comment: 4 pages, 2 figure
Secure local area network services for a high assurance multilevel network
To reduce the cost and complexity of the current DoD information infrastructure, a Multilevel Secure (MLS) network solution eliminating hardware redundancies is required. Implementing a high assurance MLS LAN requires the ability to extend a trusted path over a TCP/IP network. No high assurance network trusted path mechanisms currently exist. We present a design and proof- of-concept implementation for a Secure LAN Server that provides the trusted path between a trusted computing base extension (TCBE) servicing a COTS PC and protocol servers executing at single sensitivity levels on the XTS-300. The trusted path establishes high assurance communications (over a TCP/IP network) between a TCBE and the Secure LAN Server. This trusted channel is used first for user authentication, then as a trusted relay between the protocol server and TCBE. All transmitted data passed over the LAN can be protected by encryption, providing assurance of integrity and confidentiality for the data. This thesis documents the implementation of a demonstration prototype Secure LAN Server using existing technology, including high assurance systems, COTS hardware, and COTS software, to provide access to multilevel data in a user-friendly environment. Our accomplishment is crucial to the development of a full scale MLS LAN.http://archive.org/details/securelocalrenet1094513583U.S. Navy (U.S.N.) authors.Approved for public release; distribution is unlimited
The discovery of male Caligus brevicaudatus Scott, 1901 (Copepoda: Caligidae) parasitic on tub gurnard, Chelidonichthys lucerna (Linnaeus) from the eastern Mediterranean
© Institute of Parasitology, Biology Centre CAS. Folia Parasitologica is an open access journal since 2015, this article is published under the terms of a Creative Commons License (http://creativecommons.org/licenses/by/4.0/). The file attached is the published version of the article
Treatment-resistant CIDP in an IgG Tubulin Autoantibody Positive Patient: case report and review of the literature
Objectives: To describe a case of rapidly relapsing chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in the setting of positive serum IgG tubulin autoantibodies.
Methods: We wrote a case report and performed a literature review of IgG tubulin autoantibodies and the use of rituximab in treatment resistant CIDP.
Results: Our case report describes a 29-year-old woman with CIDP that was resistant to treatment with steroids, intravenous immunoglobulin, and plasma exchange. An extensive workup of her rapidly relapsing CIDP was negative, with the exception of positive serum IgG tubulin autoantibodies. She ultimately stabilized on oral steroids, plasma exchange and rituximab, with a regular recurrence of weakness occurring approximately every month that led to rehospitalization.
Conclusion: Anti-tubulin antibodies could be a marker of a subtype of CIDP that is treatment resistant. We detail her clinical course to serve as an example for other cases of IgG tubulin autoantibody positive CIDP patients that could be described in the future
Modification of the Tumor Microenvironment Enhances Anti-PD-1 Immunotherapy in Metastatic Melanoma
Resistance to checkpoint-blockade treatments is a challenge in the clinic. Both primary and acquired resistance have become major obstacles, greatly limiting the long-lasting effects and wide application of blockade therapy. Many patients with metastatic melanoma eventually require further therapy. The absence of T-cell infiltration to the tumor site is a well-accepted contributor limiting immune checkpoint inhibitor efficacy. In this study, we combined intratumoral injection of plasmid IL-12 with electrotransfer and anti-PD-1 in metastatic B16F10 melanoma tumor model to increase tumor-infiltrating lymphocytes and improve therapeutic efficacy. We showed that effective anti-tumor responses required a subset of tumor-infiltrating CD8+ and CD4+ T cells. Additionally, the combination therapy induced higher MHC-I surface expression on tumor cells to hamper tumor cells escaping from immune recognition. Furthermore, we found that activating T cells by exposure to IL-12 resulted in tumors sensitized to anti-PD-1 treatment, suggesting a therapeutic strategy to improve responses to checkpoint blockade
The Structure and Interpretation of Cosmology: Part I - General Relativistic Cosmology
The purpose of this work is to review, clarify, and critically analyse modern
mathematical cosmology. The emphasis is upon mathematical objects and
structures, rather than numerical computations. This paper concentrates on
general relativistic cosmology. The opening section reviews and clarifies the
Friedmann-Robertson-Walker models of general relativistic cosmology, while
Section 2 deals with the spatially homogeneous models. Particular attention is
paid in these opening sections to the topological and geometrical aspects of
cosmological models. Section 3 explains how the mathematical formalism can be
linked with astronomical observation. In particular, the informal,
observational notion of the celestial sphere is given a rigorous mathematical
implementation. Part II of this work will concentrate on inflationary cosmology
and quantum cosmology
Transcriptomic analysis of the lesser spotted catshark (Scyliorhinus canicula) pancreas, liver and brain reveals molecular level conservation of vertebrate pancreas function
BACKGROUND: Understanding the evolution of the vertebrate pancreas is key to understanding its functions. The chondrichthyes (cartilaginous fish such as sharks and rays) have often been suggested to possess the most ancient example of a distinct pancreas with both hormonal (endocrine) and digestive (exocrine) roles. The lack of genetic, genomic and transcriptomic data for cartilaginous fish has hindered a more thorough understanding of the molecular-level functions of the chondrichthyan pancreas, particularly with respect to their “unusual” energy metabolism (where ketone bodies and amino acids are the main oxidative fuel source) and their paradoxical ability to both maintain stable blood glucose levels and tolerate extensive periods of hypoglycemia. In order to shed light on some of these processes, we carried out the first large-scale comparative transcriptomic survey of multiple cartilaginous fish tissues: the pancreas, brain and liver of the lesser spotted catshark, Scyliorhinus canicula. RESULTS: We generated a mutli-tissue assembly comprising 86,006 contigs, of which 44,794 were assigned to a particular tissue or combination of tissues based on mapping of sequencing reads. We have characterised transcripts encoding genes involved in insulin regulation, glucose sensing, transcriptional regulation, signaling and digestion, as well as many peptide hormone precursors and their receptors for the first time. Comparisons to mammalian pancreas transcriptomes reveals that mechanisms of glucose sensing and insulin regulation used to establish and maintain a stable internal environment are conserved across jawed vertebrates and likely pre-date the vertebrate radiation. Conservation of pancreatic hormones and genes encoding digestive proteins support the single, early evolution of a distinct pancreatic gland with endocrine and exocrine functions in jawed vertebrates. In addition, we demonstrate that chondrichthyes lack pancreatic polypeptide (PP) and that reports of PP in the literature are likely due cross-reaction with PYY and/or NPY in the pancreas. A three hormone islet organ is therefore the ancestral jawed vertebrate condition, later elaborated upon only in the tetrapod lineage. CONCLUSIONS: The cartilaginous fish are a great untapped resource for the reconstruction of patterns and processes of vertebrate evolution and new approaches such as those described in this paper will greatly facilitate their incorporation into the rank of “model organism”. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-1074) contains supplementary material, which is available to authorized users
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