468 research outputs found

    General Formulation of Quantum Analysis

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    A general formulation of noncommutative or quantum derivatives for operators in a Banach space is given on the basis of the Leibniz rule, irrespective of their explicit representations such as the G\^ateaux derivative or commutators. This yields a unified formulation of quantum analysis, namely the invariance of quantum derivatives, which are expressed by multiple integrals of ordinary higher derivatives with hyperoperator variables. Multivariate quantum analysis is also formulated in the present unified scheme by introducing a partial inner derivation and a rearrangement formula. Operator Taylor expansion formulas are also given by introducing the two hyperoperators δABδA1δB \delta_{A \to B} \equiv -\delta_A^{-1} \delta_B and dABδ(δA1B);Ad_{A \to B} \equiv \delta_{(-\delta_A^{-1}B) ; A} with the inner derivation δA:Q[A,Q]AQQA\delta_A : Q \mapsto [A,Q] \equiv AQ-QA. Physically the present noncommutative derivatives express quantum fluctuations and responses.Comment: Latex file, 29 pages, no figur

    Speriolin Is a Novel Spermatogenic Cell-specific Centrosomal Protein Associated with the Seventh WD Motif of Cdc20

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    The fundamental mechanisms of mitosis are conserved throughout evolution in eukaryotes, including ubiquitin-mediated proteolysis of cell cycle regulators by the anaphase-promoting complex/cyclosome. The spindle checkpoint protein Cdc20 activates the anaphase-promoting complex/cyclosome in a substrate-specific manner. It is present in the cytoplasm and concentrated in the centrosomes throughout the cell cycle, accumulates at the kinetochores in metaphase, and is no longer detected following anaphase. However, it is unknown whether Cdc20 has the same activities and distribution during meiosis in male germ cells. We found that in mice, Cdc20 accumulates in the cytoplasm of pachytene spermatocytes during meiosis I, is distributed throughout spermatocytes undergoing meiotic division, and is present in the cytoplasm of postmeiotic spermatids. Several proteins bind to and regulate the function of Cdc20 during mitosis. We identified speriolin and determined that it is a novel spermatogenic cell-specific Cdc20-binding protein, is present in the cytoplasm, and is concentrated at the centrosomes of spermatocytes and spermatids and that a leucine zipper domain is required to target speriolin to the centrosome. The seven tandem WD motifs of Cdc20 probably fold into a seven-blade beta-propeller structure, and we determined that they are required for speriolin binding and for localization of Cdc20 to the centrosomes and nucleus, suggesting that speriolin might regulate or stabilize the folding of Cdc20 during meiosis in spermatogenic cells

    Symmetry Properties on Magnetization in the Hubbard Model at Finite Temperatures

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    By making use of some symmetry properties of the relevant Hamiltonian, two fundamental relations between the ferromagnetic magnetization and a spin correlation function are derived for the d(=1,2,3)d (=1,2,3)-dimensional Hubbard model at finite temperatures. These can be viewed as a kind of Ward-Takahashi identities. The properties of the magnetization as a function of the applied field are discussed. The results thus obtained hold true for both repulsive and attractive on-site Coulomb interactions, and for arbitrary electron fillings.Comment: Latex file, no figur

    Off-Diagonal Long-Range Order in Bose Liquids: Irrotational Flow and Quantization of Circulation

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    On the basis of gauge invariance, it is proven in an elementary and straightforward manner, but without invoking any {\it ad hoc} assumption, that the existence of off-diagonal long-range order in one-particle reduced density matrix in Bose liquids implies both the irrotational flow in a simply connected region and the quantization of circulation in a multiply connected region, the two fundamental properties of a Bose superfluid. The origin for both is the phase coherence of condensate wave-functions. Some relevant issues are also addressed.Comment: Revtex, 4 pages, no figure

    International Veterinary Epilepsy Task Force recommendations for systematic sampling and processing of brains from epileptic dogs and cats

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    Traditionally, histological investigations of the epileptic brain are required to identify epileptogenic brain lesions, to evaluate the impact of seizure activity, to search for mechanisms of drug-resistance and to look for comorbidities. For many instances, however, neuropathological studies fail to add substantial data on patients with complete clinical work-up. This may be due to sparse training in epilepsy pathology and or due to lack of neuropathological guidelines for companion animals. The protocols introduced herein shall facilitate systematic sampling and processing of epileptic brains and therefore increase the efficacy, reliability and reproducibility of morphological studies in animals suffering from seizures. Brain dissection protocols of two neuropathological centres with research focus in epilepsy have been optimised with regards to their diagnostic yield and accuracy, their practicability and their feasibility concerning clinical research requirements. The recommended guidelines allow for easy, standardised and ubiquitous collection of brain regions, relevant for seizure generation. Tissues harvested the prescribed way will increase the diagnostic efficacy and provide reliable material for scientific investigations

    Thickening of the pulmonary artery wall in acute intramural hematoma of the ascending aorta

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    BACKGROUND: The occurrence of pulmonary artery obstruction in the course of acute aortic dissection is an unusual complication. The mechanism implicated is the rupture of the outer layer of the aorta and the subsequent hemorrhage into the adventitia of the pulmonary artery that causes its wall thickening and, at times, produces extrinsic obstruction of the vessel. There are no reports of this complication in acute intramural hematoma. CASE PRESENTATION: An 87-year-old woman was admitted to the hospital in shock after having had severe chest pain followed by syncope. An urgent transesophageal echocardiogram revealed the presence of acute intramural hematoma, no evidence of aortic dissection, severe pericardial effusion with cardiac tamponade, and periaortic hematoma that involved the pulmonary artery generating circumferential wall thickening of its trunk and right branch with no evidence of flow obstruction. Urgent surgery was performed but the patient died in the operating room. The post mortem examination, in the operating room, confirmed that there was an extensive hematoma around the aorta and beneath the adventitial layer of the pulmonary artery, with no evidence of flow obstruction. CONCLUSION: This is the first time that this rare complication is reported in the scenario of acute intramural hematoma and with the transesophageal echocardiogram as the diagnostic tool

    Pituitary Adenylate Cyclase-Activating Polypeptide Stimulates Glucose Production via the Hepatic Sympathetic Innervation in Rats

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    OBJECTIVE-The unraveling of the elaborate brain networks that control glucose metabolism presents one of the current challenges in diabetes research. Within the central nervous system, the hypothalamus is regarded as the key brain area to regulate energy homeostasis. The aim of the present study was to investigate the hypothalamic mechanism involved in the hyperglycemic effects of the neuropeptide pituitary adenylyl cyclase-activating polypeptide (PACAP). RESEARCH DESIGN AND METHODS-Endogenous glucose production (EGP) was determined during intracerebroventricular infusions of PACAP-38, vasoactive intestinal peptide (VIP), or their receptor agonists. The specificity of their receptors was examined by coinfusions of receptor antagonists. The possible neuronal pathway involved was investigated by 1) local injections in hypothalamic nuclei, 2) retrograde neuronal tracing from the thoracic spinal cord to hypothalamic preautonomic neurons together with Fos immunoreactivity, and 3) specific hepatic sympathetic or parasympathetic denervation to block the autonomic neuronal input to liver. LTS-Intracerebroventiicular infusion of PACAP-38 increased EGP to a similar extent as a VIP/PACAP-2 (VPAC2) receptor agonist, and intracerebroventricular administration of VIP had significantly less influence on EGP. The PACAP-38 induced increase of EGP was significantly suppressed by preinfusion of a VPAC2 but not a PAC1 receptor antagonist, as well as by hepatic sympathetic but not parasympathetic denervation. In the hypothalamus, Fos immunoreactivity induced by PACAP-38 was colocalized within autonomic neurons in paraventricular nuclei projecting to preganglionic sympathetic neurons in the spinal cord. Local infusion of PACAP-38 directly into the PVN induced a significant increase of EGP. CONCLUSIONS-This study demonstrates that PACAP-38 signaling via sympathetic preautonomic neurons located in the paraventricular nucleus is an important component in the hypothalamic control of hepatic glucose production. Diabetes 59: 1591-1600, 201

    A Novel Screening System for Claudin Binder Using Baculoviral Display

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    Recent progress in cell biology has provided new insight into the claudin (CL) family of integral membrane proteins, which contains more than 20 members, as a target for pharmaceutical therapy. Few ligands for CL have been identified because it is difficult to prepare CL in an intact form. In the present study, we developed a method to screen for CL binders by using the budded baculovirus (BV) display system. CL4-displaying BV interacted with a CL4 binder, the C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE), but it did not interact with C-CPE that was mutated in its CL4-binding region. C-CPE did not interact with BV and CL1-displaying BV. We used CL4-displaying BV to select CL4-binding phage in a mixture of a scFv-phage and C-CPE-phage. The percentage of C-CPE-phage in the phage mixture increased from 16.7% before selection to 92% after selection, indicating that CL-displaying BV may be useful for the selection of CL binders. We prepared a C-CPE phage library by mutating the functional amino acids. We screened the library for CL4 binders by affinity to CL4-displaying BV, and we found that the novel CL4 binders modulated the tight-junction barrier. These findings indicate that the CL-displaying BV system may be a promising method to produce a novel CL binder and modulator

    Financial risk tolerance of Chinese American families

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    This chapter investigates the factors that affect financial risk tolerance of Chinese American households. Research on the economic well-being of Chinese American households is extremely limited. Few national datasets differentiate Chinese Americans from other race/ethnicity groups. For this study, a survey of Chinese American households residing in Midwestern states was conducted. The results showed that about 80.5 % of the sample households expressed a willingness to take at least some financial risks. Factors that have an impact on financial risk tolerance of Chinese American households included gender, non-financial assets, income, and investment time horizon. Chinese Americans represents a small but fast-growing population in the USA. More research should be done to better serve the financial needs of this group.Includes bibliographical references
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