2,053 research outputs found
Lending to Small Businesses: The Role of Loan Maturity in Adressing Information Problems
We investigate what determines the maturity of loans to small, informationally opaque businesses.We find that longer maturities are associated with collateral pledges, better financial condition, good credit history, and less informational opacity of the borrower.However, we do not find a positive association between stronger firm-creditor relationships (which can attenuate these information asymmetries) and longer maturities.The evidence suggests that creditors use shorter maturities to induce more frequent renegotiation of contract terms, thus enforcing closer monitoring of more informationally opaque and risky borrowers.Overall, our results are consistent with shorter loan maturities mitigating the consequences of borrower-lender informational asymmetries.small business;bank lending;loans;information
Territorios y textos en conflicto: Las novelas porteñas durante la Confederación Argentina
Después de la batalla de Caseros, Justo J. de Urquiza asumió el poder del Estado y su primer deseo fue concretar la redacción de la Constitución Nacional. Bajo el signo de la oposición porteña, viajó a Santa Fe en septiembre de 1852 y presidió el Congreso Constituyente, pero tres días después de su partida, una parte del ejército urquicista se sublevó y se unió a la dirigencia porteña disidente. A partir de entonces, Buenos Aires se declaró independiente de las demás provincias argentinas. A pesar de la situación crítica, la Constitución fue sancionada y nombraba a Buenos Aires como capital de la nación, pero dada la disidencia porteña, la Confederación Argentina designó a Paraná como cabeza del país y al general Urquiza como presidente del mismo. Los miembros del nuevo gobierno estaban de acuerdo con que había que modernizar al país y dar a la población garantías cívicas que favorecieran el progreso (Botana 50). Al mismo tiempo, era necesario encauzar a la Confederación en los carriles de la Constitución, una tarea nada sencilla porque la arbitrariedad y la violación de derechos conformaba una situación generalizada.Facultad de Humanidades y Ciencias de la Educació
Territorios y textos en conflicto: Las novelas porteñas durante la Confederación Argentina
Después de la batalla de Caseros, Justo J. de Urquiza asumió el poder del Estado y su primer deseo fue concretar la redacción de la Constitución Nacional. Bajo el signo de la oposición porteña, viajó a Santa Fe en septiembre de 1852 y presidió el Congreso Constituyente, pero tres días después de su partida, una parte del ejército urquicista se sublevó y se unió a la dirigencia porteña disidente. A partir de entonces, Buenos Aires se declaró independiente de las demás provincias argentinas. A pesar de la situación crítica, la Constitución fue sancionada y nombraba a Buenos Aires como capital de la nación, pero dada la disidencia porteña, la Confederación Argentina designó a Paraná como cabeza del país y al general Urquiza como presidente del mismo. Los miembros del nuevo gobierno estaban de acuerdo con que había que modernizar al país y dar a la población garantías cívicas que favorecieran el progreso (Botana 50). Al mismo tiempo, era necesario encauzar a la Confederación en los carriles de la Constitución, una tarea nada sencilla porque la arbitrariedad y la violación de derechos conformaba una situación generalizada.Facultad de Humanidades y Ciencias de la Educació
Models of the SL9 Impacts II. Radiative-hydrodynamic Modeling of the Plume Splashback
We model the plume "splashback" phase of the SL9 collisions with Jupiter
using the ZEUS-3D hydrodynamic code. We modified the Zeus code to include gray
radiative transport, and we present validation tests. We couple the infalling
mass and momentum fluxes of SL9 plume material (from paper I) to a jovian
atmospheric model. A strong and complex shock structure results. The modeled
shock temperatures agree well with observations, and the structure and
evolution of the modeled shocks account for the appearance of high excitation
molecular line emission after the peak of the continuum light curve. The
splashback region cools by radial expansion as well as by radiation. The
morphology of our synthetic continuum light curves agree with observations over
a broad wavelength range (0.9 to 12 microns). A feature of our ballistic plume
is a shell of mass at the highest velocities, which we term the "vanguard".
Portions of the vanguard ejected on shallow trajectories produce a lateral
shock front, whose initial expansion accounts for the "third precursors" seen
in the 2-micron light curves of the larger impacts, and for hot methane
emission at early times. Continued propagation of this lateral shock
approximately reproduces the radii, propagation speed, and centroid positions
of the large rings observed at 3-4 microns by McGregor et al. The portion of
the vanguard ejected closer to the vertical falls back with high z-component
velocities just after maximum light, producing CO emission and the "flare" seen
at 0.9 microns. The model also produces secondary maxima ("bounces") whose
amplitudes and periods are in agreement with observations.Comment: 13 pages, 9 figures (figs 3 and 4 in color), accepted for Ap.J.
latex, version including full figures at:
http://oobleck.tn.cornell.edu/jh/ast/papers/slplume2-20.ps.g
Towards interoperability through inter-enterprise collaboration architectures
Most enterprise architectures published so far are capable of
generating reasonably good descriptive models for individual enterprises to
enable integration, organization and synchronization of enterprise elements:
organizational structure, business processes, information systems and
technology infrastructure, among others. However, research in this field applied
to the extended enterprise or inter-enterprise architectures that takes into
account the growing trend towards complex collaborative environments is very
scarce. In this sense, this article seeks to analyze, link and synthesize the
researches that has addressed the disciplines of enterprise architecture and
business collaboration, in order to identify possible future research needs from
the conceptualization made.Vargas, A.; Boza Garcia, A.; Cuenca, L. (2011). Towards interoperability through inter-enterprise collaboration architectures. En On the Move to Meaningful Internet Systems: OTM 2011 Workshops. Springer Verlag (Germany). 7046:102-111. doi:10.1007/978-3-642-25126-9_18S1021117046Adam, O., Hofer, A., Zang, S., Hammer, C., Jerrentrup, M., Leinenbach, S.: A Collaboration Framework for Cross-enterprise Business Process Management. In: First International Conference on Interoperability of Enterprise Software and Application, Geneva (2005)Chalmeta, R., Grangel, R.: ARDIN extension for virtual enterprise integration. The Journal of Systems and Software 67, 141–152 (2003)Choi, Y., Kang, D., Chae, H., Kim, K.: An enterprise architecture framework for collaboration of virtual enterprise chains. The International Journal of Advanced Manufacturing Technology 35, 1065–1078 (2008)Schekkerman, J.: Extended Enterprise Architecture Framework Essentials Guide. Institute For Enterprise Architecture Developments, IFEAD (2006), http://www.enterprise-architecture.info/index.htmISO 15704. Industrial automation systems - Requirements for enterprise-reference architectures and methodologies.: International Organization for Standardization (2000)Kosanke, K., Vernadat, F., Zelm, M.: CIMOSA: Enterprise engineering and integration. Computers in Industry 40, 83–97 (1999)Cuenca, L.: Marco arquitectónico para la propuesta IE-GIP. Extensión de la arquitectura CIMOSA. Aplicación a una empresa del sector cerámico. PhD thesis. Universidad Politécnica de ValenciaMolina, A., Panetto, H., Chen, D., Whitman, L.: Enterprise Integration and Networking: challenges and trends. Studies in Informatics and Control 16(4), 353–368 (2007)Ortiz, A., Lario, F., Ros, L.: Enterprise Integration—Business Processes Integrated Management: a proposal for a methodology to develop Enterprise Integration Programs. Computers in Industry 40, 155–171 (1999)Chalmeta, R., Campos, C., Grangel, R.: References architectures for enterprise integration. The Journal of Systems and Software 57, 175–191 (2001)Vernadat, F.: Enterprise modeling and integration (EMI): Current status and research perspectives. Annual Reviews in Control 26, 15–25 (2002)Williams, T., Li, H.: PERA and GERAM enterprise reference architectures in enterprise integration. Information Infrastructure Systems for Manufacturing, 1–27 (1998)Lankhorst, M.: Enterprise Architecture at Work: Modelling, Communication and Analysis. Springer, Heidelberg (2009)Arango, M., Londoño, J., Zapata, J.: Arquitectura empresarial- Una visión general. Revista Ingenierías Universidad de Medellín 9(16), 101–111 (2010)Bernard, S.: An introduction to enterprise architecture. AuthorHouse, Bloomington (2005)Cuenca, L., Ortiz, A., Boza, A.: Arquitectura de Empresa. Visión General. In: IX Congreso de Ingeniería de Organización, Gijón (2005)Maya, E.: Arquitectura empresarial: un nuevo reto para las empresas de hoy. Centro de Investigación de las Telecomunicaciones. INTERACTIC: Interacción con la información (2010), http://www.interactic.org.co/THE OPEN GROUP.: ARCHIMATE, The Power of Enterprise Architecture (2009), http://www.archimate.org/en/home/Stelzer, D.: Enterprise Architecture Principles: Literature Review and Research Directions. In: Dan, A., Gittler, F., Toumani, F. (eds.) ICSOC/ServiceWave 2009. LNCS, vol. 6275, pp. 12–21. Springer, Heidelberg (2010)Schekkerman, J.: Enterprise architecture validation. Achieving business-aligned and validated enterprise architectures. Institute For Enterprise Architecture Developments, IFEAD (2004), http://www.enterprise-architecture.info/index.htmKosanke, K.: CIMOSA Primer on key concepts, purpose and business value (1996), http://cimosa.cnt.pl/Chen, D., Vallespir, B., Doumeingts, G.: GRAI integrated methodology and its mapping onto generic enterprise reference architecture and methodology. Computers in Industry 33, 387–394 (1997)Rathwell, G.: PERA Enterprise Integration Web Site (2005), http://www.pera.net/Williams, T., Rathwell, G., Li, H.: A handbook on master planning and implementation for enterprise integration programs. PERA Enterprise Integration Web Site (2001), http://www.pera.net/IFIP.: GERAM: Generalised Enterprise Reference Architecture and Methodology. International Federation for Information Processing (1999), http://dl.ifip.org/index.php/index/indexOrtiz, A.: Propuesta para el Desarrollo de Programas de Integración Empresarial en Empresas Industriales. Aplicación a una Empresa del Sector Cerámico. Universidad Politécnica de Valencia (1998)Cuenca, L., Boza, A., Ortiz, A.: Architecting business and IS/IT strategic alignment for extend enterprises. Studies in Informatics and Control 20(1), 7–18 (2011)The Open Group (2011), https://www.opengroup.org/index.htmGrangel, R.: Propuesta para el Modelado del Conocimiento Empresarial. PhD thesis Universidad Jaume I de Castello (2007)Scheer, A., Schneider, K.: ARIS – Architecture of Integrated Information. Handbook on Architectures of Information Systems. International Handbooks on Information Systems 3, 605–623 (2006)ISO/CEN 19439. Enterprise integration - Framework for enterprise modelling.: International Organization for Standardization (2006)Stadtler, H., Kilger, C.: Supply Chain Management and advance planning. Concepts, Models, Sofware and Cases Studies. Springer, Heidelberg (2002)Alarcón, F., Ortiz, A., Alemany, M., Lario, F.: Planificación Colaborativa en un contexto de varias Cadenas de Suministro: ventajas y desventajas. In: VIII Congreso de Ingeniería de Organización, Leganés, pp. 857–866 (2004)Alarcón, F.: Desarrollo de una Arquitectura para la definición del proceso de Comprometer Pedidos en contextos de Redes de Suministro Colaborativas. Aplicación a una Red compuesta por Cadenas de Suministro en los Sectores Cerámico y del Mueble. PhD thesis Universidad Politécnica de Valencia (2005)Petersen, K., Ragatz, G., Monczka, R.: An Examination of Collaborative Planning Effectiveness and Supply Chain Performance. The Journal of Supply Chain Management 41(2), 14–25 (2005)Ribas, I., Companys, R.: Estado del arte de la planificación colaborativa en la cadena de suministro: Contexto determinista e incierto. Intangible Capital, 91–121 (2007)Ribas, I., Lario, F., Companys, R.: Modelos para la planificación colaborativa en la cadena de suministro: contexto determinista e incierto. In: Congreso de ingeniería de organización, Valencia, pp. 1–10 (2006)Dudek, G.: Collaborative Planning in Supply Chains. Supply Chain Management and Collaborative Planning. Springer, Heidelberg (2009)Stadtler, H.: A framework for collaborative planning and state-of-the-art. OR Spectrum 31, 5–30 (2009)Kilger, C., Reuter, B., Stadtler, H.: Collaborative Planning. In: Stadtler, H., Kilger, C. (eds.) Supply Chain Management and Advanced Planning-—Concepts, Models Software and Case Studies, pp. 263–284. Springer, Heidelberg (2008)Audy, J., Lehoux, N., D’Amours, S.: A framework for an efficient implementation of logistics collaborations. International Transactions in Operational Research, 1–25 (2010)Zachman, J.: A Framework for Information Systems Architecture. IBM Systems Journal 26(3), 454–470 (1987
Newly impaired glucose metabolism and prognosis after percutaneous revascularization
Background: Clinical practice guidelines recommend ad hoc screening of diabetes in patients admitted for macrovascular disease; however, these recommendations are rarely followed in real practice. This study was undertaken to assess whether impaired glucose metabolism, newly diagnosed after percutaneous coronary intervention (PCI) or known diabetes, provides prognostic information. Methods: We studied 374 patients who underwent PCI. An oral glucose tolerance test was carried out in the known non-diabetic patients with fasting glucose < 7 mmol/L. Results: Eighty-one percent of the patients presented impaired glucose metabolism, from which 35.3% were previously diagnosed with diabetics, 21.4% were newly detected diabetics, and 24.3% were pre-diabetics. After a mean follow-up of 35.8 ± 13.4 months, only a known history of diabetes was an independent predictor of revascularization (OR = 2.03, p = 0.025), non-fatal acute myocardial infarction (OR = 2.70, p = 0.029) and readmission due to heart failure during the follow-up (OR = 3.82, p = 0.022). Conclusions: Screening for impaired glucose metabolism after PCI permits the detection of a high proportion of patients with abnormal glucose regulations. However, previously known diabetes remains the only independent predictor of cardiovascular events in the follow-up.
Models of the SL9 Impacts I. Ballistic Monte-Carlo Plume
We model the Comet Shoemaker-Levy 9 - Jupiter impact plumes to calculate
synthetic plume views, atmospheric infall fluxes, and debris patterns. Our
plume is a swarm of ballistic particles with one of several mass-velocity
distributions (MVD). The swarm is ejected instantaneously and uniformly into a
cone from its apex. Upon falling to the ejection altitude, particles slide with
horizontal deceleration following one of several schemes. The model ignores
hydrodynamic and Coriolis effects. We adjust plume tilt, opening angle, and
minimum velocity, and choose MVD and sliding schemes, to create impact patterns
that match observations. Our best match uses the power-law MVD from the
numerical impact model of Zahnle and Mac Low, with velocity cutoffs at 4.5 and
11.8 km/sec, cone opening angle of 75 degrees, cone tilt of 30 degrees from
vertical, and a sliding constant deceleration of 1.74 m/sec^2. A
mathematically-derived feature of Zahnle and Mac Low's published cumulative MVD
is a thin shell of mass at the maximum velocity, corresponding to the former
atmospheric shock front. This vanguard contains 22% of the mass and 45% of the
energy of the plume, and accounts for several previously-unexplained
observations, including the large, expanding ring seen at 3.2 microns by
McGregor et al. and the ``third precursors'' and ``flare'' seen near 300 and
1000 sec, respectively, in the infrared lightcurves. We present synthetic views
of the plumes in flight and after landing and derive infall fluxes of mass,
energy, and vertical momentum as a function of time and position on the
surface. These fluxes initialize a radiative-hydrodynamic atmosphere model
(Paper II of this series) that calculates the thermal and dynamical response of
the atmosphere and produces synthetic lightcurves.Comment: Accepted by ApJ. 15 pages, 12 figures, LaTeX/AASTeX. Fig. 10 (p. 12)
is color. Version with full-resolution figures available at
http://oobleck.tn.cornell.edu/jh/ast/papers/slplume1-20.ps.g
Differences between <i>Trypanosoma brucei gambiense</i> groups 1 and 2 in their resistance to killing by Trypanolytic factor 1
<p><b>Background:</b> The three sub-species of <i>Trypanosoma brucei</i> are important pathogens of sub-Saharan Africa. <i>T. b. brucei</i> is unable to infect humans due to sensitivity to trypanosome lytic factors (TLF) 1 and 2 found in human serum. <i>T. b. rhodesiense</i> and <i>T. b. gambiense</i> are able to resist lysis by TLF. There are two distinct sub-groups of <i>T. b. gambiense</i> that differ genetically and by human serum resistance phenotypes. Group 1 <i>T. b. gambiense</i> have an invariant phenotype whereas group 2 show variable resistance. Previous data indicated that group 1 <i>T. b. gambiense</i> are resistant to TLF-1 due in-part to reduced uptake of TLF-1 mediated by reduced expression of the TLF-1 receptor (the haptoglobin-hemoglobin receptor (<i>HpHbR</i>)) gene. Here we investigate if this is also true in group 2 parasites.</p>
<p><b>Methodology:</b> Isogenic resistant and sensitive group 2 <i>T. b. gambiense</i> were derived and compared to other T. brucei parasites. Both resistant and sensitive lines express the <i>HpHbR</i> gene at similar levels and internalized fluorescently labeled TLF-1 similar fashion to <i>T. b. brucei</i>. Both resistant and sensitive group 2, as well as group 1 <i>T. b. gambiense</i>, internalize recombinant APOL1, but only sensitive group 2 parasites are lysed.</p>
<p><b>Conclusions:</b> Our data indicate that, despite group 1 <i>T. b. gambiense</i> avoiding TLF-1, it is resistant to the main lytic component, APOL1. Similarly group 2 <i>T. b. gambiense</i> is innately resistant to APOL1, which could be based on the same mechanism. However, group 2 <i>T. b. gambiense</i> variably displays this phenotype and expression does not appear to correlate with a change in expression site or expression of <i>HpHbR</i>. Thus there are differences in the mechanism of human serum resistance between <i>T. b. gambiense</i> groups 1 and 2.</p>
Monte Carlo verification of radiotherapy treatments with CloudMC
Background
A new implementation has been made on CloudMC, a cloud-based platform presented in a previous work, in order to provide services for radiotherapy treatment verification by means of Monte Carlo in a fast, easy and economical way. A description of the architecture of the application and the new developments implemented is presented together with the results of the tests carried out to validate its performance.
Methods
CloudMC has been developed over Microsoft Azure cloud. It is based on a map/reduce implementation for Monte Carlo calculations distribution over a dynamic cluster of virtual machines in order to reduce calculation time. CloudMC has been updated with new methods to read and process the information related to radiotherapy treatment verification: CT image set, treatment plan, structures and dose distribution files in DICOM format. Some tests have been designed in order to determine, for the different tasks, the most suitable type of virtual machines from those available in Azure. Finally, the performance of Monte Carlo verification in CloudMC is studied through three real cases that involve different treatment techniques, linac models and Monte Carlo codes.
Results
Considering computational and economic factors, D1_v2 and G1 virtual machines were selected as the default type for the Worker Roles and the Reducer Role respectively. Calculation times up to 33 min and costs of 16 € were achieved for the verification cases presented when a statistical uncertainty below 2% (2σ) was required. The costs were reduced to 3–6 € when uncertainty requirements are relaxed to 4%.
Conclusions
Advantages like high computational power, scalability, easy access and pay-per-usage model, make Monte Carlo cloud-based solutions, like the one presented in this work, an important step forward to solve the long-lived problem of truly introducing the Monte Carlo algorithms in the daily routine of the radiotherapy planning process
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