4,282 research outputs found

    Metastatic intraocular hemangiopericytoma in a dog

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    A 10-year-old Labrador Retriever who had been undergoing therapy for a recurrent hemangiopericytoma of the right flank presented to the Kansas State University Ophthalmology service for evaluation of a painful left eye. Examination revealed secondary glaucoma and irreversible blindness of the affected eye and multifocal chorioretinal lesions in the fellow eye. Therapeutic and diagnostic enucleation of the left eye was performed and histopathologic examination demonstrated the presence of a presumed metastatic spindle cell sarcoma. Further immunohistochemical staining confirmed the intraocular neoplasia to be metastatic spread from the previously removed flank mass. Rapid progression in size and number of chorioretinal lesions in the right eye was noted in the post-operative period until the patient was euthanized one month after surgery. This case report is the first to document intraocular metastasis of hemangiopericytoma in a veterinary patient

    Contribution of an SFK-Mediated Signaling Pathway in the Dorsal Hippocampus to Cocaine-Memory Reconsolidation in Rats

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    Environmentally induced relapse to cocaine seeking requires the retrieval of context–response–cocaine associative memories. These memories become labile when retrieved and must undergo reconsolidation into long-term memory storage to be maintained. Identification of the molecular underpinnings of cocaine-memory reconsolidation will likely facilitate the development of treatments that mitigate the impact of cocaine memories on relapse vulnerability. Here, we used the rat extinction-reinstatement procedure to test the hypothesis that the Src family of tyrosine kinases (SFK) in the dorsal hippocampus (DH) critically controls contextual cocaine-memory reconsolidation. To this end, we evaluated the effects of bilateral intra-DH microinfusions of the SFK inhibitor, PP2 (62.5 ng per 0.5 μl per hemisphere), following re-exposure to a cocaine-associated (cocaine-memory reactivation) or an unpaired context (no memory reactivation) on subsequent drug context-induced instrumental cocaine-seeking behavior. We also assessed alterations in the phosphorylation state of SFK targets, including GluN2A and GluN2B N-methyl-D-aspartate (NMDA) and GluA2 α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunits at the putative time of memory restabilization and following PP2 treatment. Finally, we evaluated the effects of intra-DH PEAQX (2.5 μg per 0.5 μl per hemisphere), a GluN2A-subunit-selective NMDAR antagonist, following, or in the absence of, cocaine-memory reactivation on subsequent drug context-induced cocaine-seeking behavior. GluN2A phosphorylation increased in the DH during putative memory restabilization, and intra-DH PP2 treatment inhibited this effect. Furthermore, PP2—as well as PEAQX—attenuated subsequent drug context-induced cocaine-seeking behavior, in a memory reactivation-dependent manner, relative to VEH. These findings suggest that hippocampal SFKs contribute to the long-term stability of cocaine-related memories that underlie contextual stimulus control over cocaine-seeking behavior

    Closing of the Induced Gap in a Hybrid Superconductor-Semiconductor Nanowire

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    Hybrid superconductor-semiconductor nanowires are predicted to undergo a field-induced phase transition from a trivial to a topological superconductor, marked by the closure and re-opening of the excitation gap, followed by the emergence of Majorana bound states at the nanowire ends. Many local density-of-states measurements have reported signatures of the topological phase, however this interpretation has been challenged by alternative explanations. Here, by measuring nonlocal conductance, we identify the closure of the excitation gap in the bulk of the semiconductor before the emergence of zero-bias peaks. This observation is inconsistent with scenarios where zero-bias peaks occur due to end-states with a trivially gapped bulk, which have been extensively considered in the theoretical and experimental literature. We observe that after the gap closes, nonlocal signals fluctuate strongly and persist irrespective of the presence of local-conductance zero-bias peaks. Thus, our observations are also incompatible with a simple picture of clean topological superconductivity. This work presents a new experimental approach for probing the spatial extent of states in Majorana wires, and reveals the presence of a regime with a continuum of spatially extended states and uncorrelated zero-bias peaks

    Pre-transplant antibody screening and anti-CD154 costimulation blockade promote long-term xenograft survival in a pig-to-primate kidney transplant model

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    Xenotransplantation has the potential to alleviate the organ shortage that prevents many patients with end-stage renal disease from enjoying the benefits of kidney transplantation. Despite significant advances in other models, pig-to-primate kidney xenotransplantation has met limited success. Preformed anti-pig antibodies are an important component of the xenogeneic immune response. To address this, we screened a cohort of 34 rhesus macaques for anti-pig antibody levels. We then selected animals with both low and high titers of anti-pig antibodies to proceed with kidney transplant from galactose-α1,3-galactose knockout/CD55 transgenic pig donors. All animals received T-cell depletion followed by maintenance therapy with costimulation blockade (either anti-CD154 mAb or belatacept), mycophenolate mofetil, and steroid. The animal with the high titer of anti-pig antibody rejected the kidney xenograft within the first week. Low-titer animals treated with anti-CD154 antibody, but not belatacept exhibited prolonged kidney xenograft survival (>133 and >126 vs. 14 and 21 days, respectively). Long-term surviving animals treated with the anti-CD154-based regimen continue to have normal kidney function and preserved renal architecture without evidence of rejection on biopsies sampled at day 100. This description of the longest reported survival of pig-to-non-human primate kidney xenotransplantation, now >125 days, provides promise for further study and potential clinical translation

    J. L. Austin and literal meaning

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    Alice Crary has recently developed a radical reading of J. L. Austin's philosophy of language. The central contention of Crary's reading is that Austin gives convincing reasons to reject the idea that sentences have context-invariant literal meaning. While I am in sympathy with Crary about the continuing importance of Austin's work, and I think Crary's reading is deep and interesting, I do not think literal sentence meaning is one of Austin's targets, and the arguments that Crary attributes to Austin or finds Austinian in spirit do not provide convincing reasons to reject literal sentence meaning. In this paper, I challenge Crary's reading of Austin and defend the idea of literal sentence meaning

    Subjects, Topics, and Anchoring to the Context

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    The article discusses the connection between the syntactic and semantic properties of weak, strong, and referential DP subjects. In particular, I argue that nominal expressions possess a situation argument and that their interpretation and their distribution follow from the presuppositional requirements that the determiner imposes on the individual argument and situation argument of its complement nominal. These presuppositional requirements, I then argue, are embodied by local relations of the subject to a distinct head in the C domain, Fin(0) in the system of Rizzi 1997, where specific referential values of discourse antecedents are accessible

    Nanometer-scale characterization of laser-driven compression, shocks, and phase transitions, by x-ray scattering using free electron lasers

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    We study the feasibility of using small angle X-ray scattering (SAXS) as a new experimental diagnostic for intense laser-solid interactions. By using X-ray pulses from a hard X-ray free electron laser, we can simultaneously achieve nanometer and femtosecond resolution of laser-driven samples. This is an important new capability for the Helmholtz international beamline for extreme fields at the high energy density endstation currently built at the European X-ray free electron laser. We review the relevant SAXS theory and its application to transient processes in solid density plasmas and report on first experimental results that confirm the feasibility of the method. We present results of two test experiments where the first experiment employs ultra-short laser pulses for studying relativistic laser plasma interactions, and the second one focuses on shock compression studies with a nanosecond laser system
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