3,257 research outputs found

    Multipliers and Capital: What is the role of Imperfect Competition?

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    In static general equilibrium models considering imperfectly competitive goods markets, the effectiveness of fiscal policy to stir output is shown to be greater than in the walrasian case. However, labour is the only input in these models. Here, I develop a simple intertemporal model allowing us to study the steady-state role of optimal capital stock in the fiscal policy transmission mechanism. I demonstrate the results depend strongly on the set of parameter values chosen and on the output definition. Using plausible calibrations the multiplier is larger in the walrasian case for small initial government purchases, and smaller for intermediate values.Multiplier, Fiscal Policy, Imperfect Competition

    A Simple Business-Cycle Model with Schumpeterian Features

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    We develop a dynamic general equilibrium model of imperfect competition where a sunk cost of creating a new product regulates the type of entry that dominates in the economy: new products or more competition in existing industries. Considering the process of product innovation is irreversible, introduces hysteresis in the business cycle. Expansionary shocks may lead the economy to a new ‘prosperity plateau,’ but contractionary shocks only affect the market power of mature industriesEntry, Hysteresis, Mark-up

    A Simple Business-Cycle Model with Schumpeterian Features

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    We develop a dynamic general equilibrium model of imperfect competition where a sunk cost of creating a new product regulates the type of entry that dominates in the economy: new products or more competition in existing industries. Considering the process of product innovation is irreversible, introduces hysteresis in the business cycle. Expansionary shocks may lead the economy to a new 'prosperity plateau,' but contractionary shocks only affect the market power of mature industries.Entry; hysteresis, mark-up

    Exercise as a Time-conditioning Effector in Chronic Disease: a Complementary Treatment Strategy

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    Exercise has been widely believed to be a preventive and therapeutic aid in the treatment of various pathophysiological conditions such as cardiovascular disease and cancer. A common problem associated with such pathologies is cachexia, characterized by progressive weight loss and depletion of lean and fat body mass, and is linked to poor prognosis. As this syndrome comprises changes in many physiological systems, it is tempting to assume that the modulation of the psychoneuroimmunoendocrine axis could attenuate or even prevent cachexia progression in cancer patients. Cancer cachexia is characterized by a disruption in the rhythmic secretion of melatonin, an important time-conditioning effector. This hormone, secreted by the pineal gland, transmits circadian and seasonal information to all organs and cells of the body, synchronizing the organism with the photoperiod. Considering that exercise modulates the immune response through at least two different mechanisms—metabolic and neuroendocrine—we propose that the adoption of a regular exercise program as a complementary strategy in the treatment of cancer patients, with the exercise bouts regularly performed at the same time of the day, will ameliorate cachexia symptoms and increase survival and quality of life

    A simple business-cycle model with shumpeterian features

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    We develop a dynamic general equilibrium model of imperfect competition where a sunk cost of creating a new product regulates the type of entry that dominates in the economy: new products or more competition in existing industries. Considering the process of product innovation is irreversible, introduces hysteresis in the business cycle. Expansionary shocks may lead the economy to a new ‘prosperity plateau,’ but contractionary shocks only affect the market power of mature industries

    Automatic Segmentation of Monofilament Testing Sites in Plantar Images for Diabetic Foot Management

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    Diabetic peripheral neuropathy is a major complication of diabetes mellitus, and it is the leading cause of foot ulceration and amputations. The Semmes–Weinstein monofilament examination (SWME) is a widely used, low-cost, evidence-based tool for predicting the prognosis of diabetic foot patients. The examination can be quick, but due to the high prevalence of the disease, many healthcare professionals can be assigned to this task several days per month. In an ongoing project, it is our objective to minimize the intervention of humans in the SWME by using an automated testing system relying on computer vision. In this paper we present the project’s first part, constituting a system for automatically identifying the SWME testing sites from digital images. For this, we have created a database of plantar images and developed a segmentation system, based on image processing and deep learning—both of which are novelties. From the 9 testing sites, the system was able to correctly identify most 8 in more than 80% of the images, and 3 of the testing sites were correctly identified in more than 97.8% of the images.Partially supported by FCT-UIDB/04730/2020 and FCT-UIDB/50014/2020 projects.info:eu-repo/semantics/publishedVersio

    Non-smooth dynamics and multiple equilibria in a Cournot-Ramsey model with endogenous markups

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    We consider a Ramsey model with a continuum of Cournotian industries where free entry generates an endogenous markup. The model produces two different regimes, monopoly and oligopoly, resulting in non-smooth dynamics. We analyze the global dynamics of the model, demonstrating the model may exhibit heteroclinic orbits connecting multiple equilibria. Small transitory changes in parameters can lead to large permanent effects and there can be a Rostovian poverty trap separating a low-capital and high-markup equilibrium from a high-capital low-markup equilibrium. The paper applies recent results from applied mathematics for non-smooth dynamic systems

    Synthesis, structure, and optical properties of an alternating calix[4]arene-based meta-linked phenylene ethynylene copolymer

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    Novel alternating copolymers comprising biscalix[4]arene-p-phenylene ethynylene and m-phenylene ethynylene units (CALIX-m-PPE) were synthesized using the Sonogashira-Hagihara cross-coupling polymerization. Good isolated yields (60-80%) were achieved for the polymers that show M-n ranging from 1.4 x 10(4) to 5.1 x 10(4) gmol(-1) (gel permeation chromatography analysis), depending on specific polymerization conditions. The structural analysis of CALIX-m-PPE was performed by H-1, C-13, C-13-H-1 heteronuclear single quantum correlation (HSQC), C-13-H-1 heteronuclear multiple bond correlation (HMBC), correlation spectroscopy (COSY), and nuclear overhauser effect spectroscopy (NOESY) in addition to Fourier transform-Infrared spectroscopy and microanalysis allowing its full characterization. Depending on the reaction setup, variable amounts (16-45%) of diyne units were found in polymers although their photophysical properties are essentially the same. It is demonstrated that CALIX-m-PPE does not form ground-or excited-state interchain interactions owing to the highly crowded environment of the main-chain imparted by both calix[4]arene side units which behave as insulators inhibiting main-chain pi-pi staking. It was also found that the luminescent properties of CALIX-m-PPE are markedly different from those of an all-p-linked phenylene ethynylene copolymer (CALIX-p-PPE) previously reported. The unexpected appearance of a low-energy emission band at 426 nm, in addition to the locally excited-state emission (365 nm), together with a quite low fluorescence quantum yield (Phi = 0.02) and a double-exponential decay dynamics led to the formulation of an intramolecular exciplex as the new emissive species

    Susceptibilities of enterococcus faecalis biofilms to some antimicrobial medications

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    Enterococcus faecalis has bEnterococcus faecalis has been suggested to be an important etiological agent in endodontic failures. The purpose of this study was to evaluate the effectiveness of chlorhexidine- or antibiotics-based medications in eliminating E. faecalis biofilms. One-day and three-day biofilms of E. faecalis were induced on cellulose nitrate membrane filters. Each biofilm-containing membrane was thoroughly covered with 1 ml of the test medications and incubated for 1 day at 37°C. Treated biofilms were then aseptically transferred to vials containing a neutralizing agent in saline solution and vortexed. Suspensions were 10-fold diluted, seeded onto Mitis salivarius agar plates, and the colony-forming units counted after 48 h of incubation. There were significant differences between the formulations tested. The association of clindamycin with metronidazole significantly reduced the number of cells in 1-day biofilms. However of all medications tested, only 2% chlorhexidine-containing medications were able to thoroughly eliminate most of both 1-day and 3-day E. faecalis biofilms

    ECOLOGY OF POLYLEPIS SPP FORESTS, AND PROPOSAL FOR ITS CONSERVATION IN THE ANDEAN REGION OF TACNA, PERU

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    The forests of Polylepis (queñoales) is one of the most important Andean forest ecosystems and with the greatest impact due to human activities. The objectives of the study were to determine the distribution and diversity of queñoa forests in the Andean region of Tacna, Peru. With this information, We propose the restoration and conservation plan for the Polylepis spp. For this purpose plots of 500 m2 were established. The sampling was simple random, taking a population census in each of the sample units in the 4 provinces (Jorge Basadre, Tacna, Tarata and Candarave). The total evaluation area was 27,491 hectares. The presence of two Polylepis species was identified. Polylepis rugulosa Bitter was registered in 9 districts with an altitudinal range of 3050 to 4226 m.a.s.l. in 6 life zones. Polylepis tarapacana Phil is distributed in the provinces of Tarata and Tacna within 3 districts. P. tarapacana occurs in an altitudinal range between 4230 and 4750 m.a.s.l. in 5 life zones. The tall and diameter of tree were variable for two species. The human impact for P. rugulosa was recorded: Not Intervented (76%), Semi Intervening (21%) and Intervened (3%). For P. tarapacana it was: Not Intervented (77%), Semi Interventions (21%) and Intervened (2%). According to the data gathered, the conservation plan is proposed, consisting of 5 guidelines: 1) education, 2) communication and capacity building, 3) conservation and sustainable management, 4) policies and regulations, and 5) research and monitoring
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