3,849 research outputs found

    Economic system dynamics

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    We provide the reader with a qualitative summary of the main ideas from econophysics and finance theory, starting with a thorough criticism of the standard ideas taught in typical economics textbooks. The emphasis is on the Galilean or physicists' approach to market synamics, as opposed to the standard nonempirical postulatory one.Utility; equilibrium; supply and demand curves; business cycles; market dynamics

    Laparoscopic resection of gastric GISTs. Where do we stand now? A single-centered experience

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    Introduction. Gastrointestinal stromal tumors (GISTs) represent a rare type of gastrointestinal neoplasms. Resection with negative margins has been established as a mainstay treatment, but laparoscopic resections are still open to debate. Material and method. This retrospective study was conducted at a single institution, with data collected over 2 years (01.01.2017-01.01.2019). The variables examined were age, tumor location with regard to the gastric wall, the results of the intraoperative endoscopy, intraoperative and postoperative complications, the surgical technique, and histopathological reports. Results. We identified 12 relevant cases, of which 8 were females and 4 males. The average tumor diameter was 2.3 cm. The majority of the lesions were located on the anterior gastric wall (8 cases), on the small curvature (2 cases), and in the pyloric region (2 cases). Intraoperative endoscopy was performed successfully in 10 cases in order to identify the lesions and guide the resection. The average operative time was 120 minutes and the average hospital stay was 5 days. The gastric wall with the lesion was resected using an Ultrasonic device, a 2-cm oncological safety margin was preserved. Conclusion. Complete surgical resection independent from the tumor size represents the current optimal treatment. From a surgical point of view, these tumors must be considered malignant and the surgeon must respect principles of oncological surgery. Maintaining tumor integrity at dissection is critical for the patient’s long-term prognosis. Laparoscopic resection independent of the tumor size is feasible

    SONTRAC—A low background, large area solar neutron spectrometer

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    SONTRAC is a scintillating fiber neutron detector designed to measure solar flare neutrons from a balloon or spacecraft platform. The instrument is comprised of alternating orthogonal planes of scintillator fibers viewed by photomultiplier tubes and image intensifier/CCD camera optics. It operates by tracking the paths of recoil protons from the double scatter of 20 to 200 MeV neutrons off hydrogen in the plastic scintillator, thereby providing the necessary information to determine the incident neutron direction and energy. SONTRAC is also capable of detecting and measuring high-energy gamma rays \u3e20 MeV as a “solid-state spark chamber.” The self-triggering and track imaging features of a prototype for tracking in two dimensions have been demonstrated in calibrations with cosmic-ray muons, 14 to ∼65 MeV neutrons and ∼20 MeV protons

    The Saccharomyces cerevisiae Mob2p-Cbk1p kinase complex promotes polarized growth and acts with the mitotic exit network to facilitate daughter cell-specific localization of Ace2p transcription factor.

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    The Saccharomyces cerevisiae mitotic exit network (MEN) is a conserved signaling network that coordinates events associated with the M to G1 transition. We investigated the function of two S. cerevisiae proteins related to the MEN proteins Mob1p and Dbf2p kinase. Previous work indicates that cells lacking the Dbf2p-related protein Cbk1p fail to sustain polarized growth during early bud morphogenesis and mating projection formation (Bidlingmaier, S., E.L. Weiss, C. Seidel, D.G. Drubin, and M. Snyder. 2001. Mol. Cell. Biol. 21:2449-2462). Cbk1p is also required for Ace2p-dependent transcription of genes involved in mother/daughter separation after cytokinesis. Here we show that the Mob1p-related protein Mob2p physically associates with Cbk1p kinase throughout the cell cycle and is required for full Cbk1p kinase activity, which is periodically activated during polarized growth and mitosis. Both Mob2p and Cbk1p localize interdependently to the bud cortex during polarized growth and to the bud neck and daughter cell nucleus during late mitosis. We found that Ace2p is restricted to daughter cell nuclei via a novel mechanism requiring Mob2p, Cbk1p, and a functional nuclear export pathway. Furthermore, nuclear localization of Mob2p and Ace2p does not occur in mob1-77 or cdc14-1 mutants, which are defective in MEN signaling, even when cell cycle arrest is bypassed. Collectively, these data indicate that Mob2p-Cbk1p functions to (a) maintain polarized cell growth, (b) prevent the nuclear export of Ace2p from the daughter cell nucleus after mitotic exit, and (c) coordinate Ace2p-dependent transcription with MEN activation. These findings may implicate related proteins in linking the regulation of cell morphology and cell cycle transitions with cell fate determination and development

    L. Tucker to Cornelia L. Littlefield (31 March 1824)

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    Lillia Skipwith Tucker (daughter of Sir Peyton Skipwith, baronet, of Mecklenburg County, VA/ Prestwould Plantation and his first wife, Ann Miller), writes to her sister-in-law, Cornelia L. Littlefield. Lillia married first George Carter and then St. George Tucker, and Cornelia was married to Lillia\u27s brother Peyton (her second marriage). Lillia\u27s is a life with many medical hardships, both her own and those of her family and friends. She asks for news of other family members.https://egrove.olemiss.edu/skipwith/1009/thumbnail.jp

    Developing Entrepreneurial Rural Communities

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    Rural communities in the United States have diversified and their dependence onagriculture has decreased substantially. In the 1980s, rural deindustrialization occurredand rural areas continued to become more service oriented: employment opportunitiesdeclined because of shifts in the world and U.S. economies, and anti-rural publicpolicies. In response, some rural communities have become entrepreneurial communities,whose characteristics include: healthy acceptance of controversy; a degree ofeconomic surplus to allow for risk-taking; willingness of community to tax itself tomaintain infrastructure and schools; the ability to define community broadly and tonetwork both vertically and horizontally to obtain resources; and dispersed communityleadership. Entrepreneurial behavior in the context of more favorable state and federalpolicies could help stabilize many rural communities

    Mechanistic analysis of an asymmetric palladium-catalyzed conjugate addition of arylboronic acids to β-substituted cyclic enones.

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    An asymmetric palladium-catalyzed conjugate addition reaction of arylboronic acids to enone substrates was investigated mechanistically. Desorption electrospray ionization coupled to mass spectrometry was used to identify intermediates of the catalytic cycle and delineate differences in substrate reactivity. Our findings provide evidence for the catalytic cycle proceeding through formation of an arylpalladium(II) cation, subsequent formation of an arylpalladium-enone complex, and, ultimately, formation of the new C-C bond. Reaction monitoring in both positive and negative ion modes revealed that 4-iodophenylboronic acid formed a relatively stable trimeric species under the reaction conditions

    Immunological Insights in Equine Recurrent Uveitis

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    Horses worldwide suffer from equine recurrent uveitis (ERU), an organ-specific, immune-mediated disease with painful, remitting-relapsing inflammatory attacks alternating with periods of quiescence, which ultimately leads to blindness. In course of disease, both eyes can eventually be affected and since blind horses pose a threat to themselves and their surroundings, these animals have to be killed. Therefore, this disease is highly relevant for veterinary medicine. Additionally, ERU shows strong clinical and pathological resemblance to autoimmune uveitis in man. The exact cause for the onset of ERU is unclear to date. T cells are believed to be the main effector cells in this disease, as they overcome the blood retinal barrier to invade the eye, an organ physiologically devoid of peripheral immune cells. These cells cause severe intraocular inflammation, especially in their primary target, the retina. With every inflammatory episode, retinal degeneration increases until eyesight is completely lost. In ERU, T cells show an activated phenotype, with enhanced deformability and migration ability, which is reflected in the composition of their proteome and downstream interaction pathways even in quiescent stage of disease. Besides the dysregulation of adaptive immune cells, emerging evidence suggests that cells of the innate immune system may also directly contribute to ERU pathogenesis. As investigations in both the target organ and the periphery have rapidly evolved in recent years, giving new insights on pathogenesis-associated processes on cellular and molecular level, this review summarizes latest developments in ERU research

    Prototype for SONTRAC: a scintillating plastic fiber detector for solar neutron spectroscopy

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    We report the scientific motivation for and performance measurements of a prototype detector system for SONTRAC, a solar neutron tracking experiment designed to study high- energy solar flare processes. The full SONTRAC instrument will measure the energy and direction of 20 to 200 MeV neutrons by imaging the ionization tracks of the recoil protons in a densely packed bundle of scintillating plastic fibers. The prototype detector consists of a 12.7 mm square bundle of 250 micrometer scintillating plastic fibers, 10 cm long. A photomultiplier detects scintillation light from one end of the fiber bundle and provides a detection trigger to an image intensifier/CCD camera system at the opposite end. The image of the scintillation light is recorded. By tracking the recoil protons from individual neutrons the kinematics of the scattering are determined, providing a high signal to noise measurement. The predicted energy resolution is 10% at 20 MeV, improving with energy. This energy resolution translates into an uncertainty in the production time of the neutron at the Sun of 30 s for a 20 MeV neutron, also improving with energy. A SONTRAC instrument will also be capable of detecting and measuring high-energy gamma rays greater than 20 MeV as a \u27solid-state spark chamber.\u27 The self-triggering and track imaging features of the prototype are demonstrated with cosmic ray muons and 14 MeV neutrons. Design considerations for a space flight instrument are presented

    Pengaruh Pemberian Biopestisida Terhadap Jenis Hama yang Menyerang Tanaman Tumpang Sari Sawi Sendok (Brassica rapa L.)

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    This study aims to determine the effect of giving biopesticides of papaya leaves with various concentrations to the death of insects that attack the mustard plant (Brassica rapa L.). This study used a completely random design consisting of 1 treatment consisting of 3 levels, with three repeats, each treatment consisting of 10 plants so that it takes 120 units of experiments. Treatments A0 (Control), A1 (100 grams), A2 (200 grams), A3(300 grams). The results showed that in the first spraying concentration of 100 grams, 200 grams, 300 grams had no real effect on the spoon mustard plant in the rainy season, then spraying was less than optimal. In the second spraying, the concentration of 100,200,300gr affects the attack of mustard plant pests, it can be seen that the pest attack has been reduced, but that makes the attack very heavy due to the presence of destructive human factors. A type of insect-resistant to treatment is the Wood Grasshopper (Valanga nigricornis). Referring to the study results, spraying biopesticides is expected to be done thoroughly to the bottom of the leaves because pests generally place their leaves under the surface of the leaves. The research process should be done when the weather is sunny, or the research land is given optimal shade value
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