483 research outputs found
Coherence phenomena between initial and final state radiation in a dense QCD medium
In this work we investigate medium modifications to the interference pattern
between initial and final state radiation. We compute single gluon production
off a highly energetic parton that undergoes a hard scattering and subsequently
crosses a dense QCD medium of finite size. We extend our previous studies
obtained at first order in opacity by providing general results for multiple
soft scatterings and their specific formulation within the harmonic oscillator
approximation. We show that there is a gradual onset of decoherence between the
initial and final state radiation due to multiple scatterings, that opens the
phase space for large angle emissions. By examining the multiplicity of
produced gluons, we observe a potentially large double logarithmic enhancement
for dense media and small opening angles. This result points to a possible
modification of the evolution equations due to a QCD medium of finite size. We
briefly comment on the phenomenological consequences of this setup in
high-energy nuclear collisions.Comment: 33 pages, 2 figures. Fix typos and updated references. Discussion in
the introduction updated. Accepted for publication in JHE
Coherence and broadening effects in medium induced gluon radiation
Interferences between different emitters in the multi-parton shower is the
building block of QCD jet physics in vacuum. The presence of a hot medium made
of quarks and gluons is expected to alter this interference pattern. To study
such effects, we derive the gluon emission spectrum off an "asymptotic quark"
traversing a hot and dense QCD medium at first order in the medium density. The
resulting induced gluon distribution gets modified when the new interference
terms between the initial and final quark are included. We comment on the
possible phenomenological consequences of this new contribution for jet
observables in heavy-ion collisions.Comment: 4 pages. To appear in the Proceedings of the conference Hard Probes
2012 - Sardinia - Italy - May 27 -June 1 201
Medium-induced radiation with vacuum propagation in the pre-hydrodynamics phase
The recent discovery of the potential of jet quenching observables to
constrain the initial stages after a heavy-ion collision makes imperative to
have a better understanding of the process of medium-induced radiation before
the formation of the quark-gluon plasma (QGP) and its impact on observables at
high-. In this work, we generalize the BDMPS-Z framework for
medium-induced radiation to account for additional emissions occurring before
the creation of the QGP. For simplicity, we assume that during the
pre-hydrodynamics phase the hard parton propagates as in vacuum. This set-up,
allows us to isolate the contribution from the additional initial radiation by
comparing with the usual scenarios in which the emitter is created inside the
medium but with different starting points. Using both a numerical
implementation of the fully resummed emission spectrum and the usual analytical
approximations, we find that replacing an initial slab of the medium by vacuum
yields to a significant reduction of the emission spectrum for low radiated
gluon energies, while the high-energy tails remain largely unmodified. Finally,
we assess the effect of replacing the initial medium by vacuum propagation on
the single-inclusive particle suppression and high- azimuthal
asymmetry . Our findings indicate that considering vacuum propagation
prior to hydrodynamization leads to an increase in the , thus
corroborating the importance of the treatment of jet quenching in the initial
stages for the correct description of both observables.Comment: 25 pages, 9 figures. Matches published version in JHE
PolinMuebles S.A.: Piensa verde y realza tu ambiente
Seminario Desarrollo de Emprendedores. 2013. Carrera Ingeniería Industrial . Docente Lic. Reyes Barreda, Abel.Empresa elaboradora de muebles ecológicos a base de polines usados. El producto resultante es de calidad y a su vez amigable con el ambiente. Para el proceso de elaboración la madera de los polines, la cual es de pino, es tratada y protegida, se le efectúa un lijado exhaustivo, limando las imperfecciones, y de esta forma se obtiene una superficie suave sin astillas. Los tipos de muebles elaborados son: de entretenimiento, trabajo, oficina; incluso hasta maceteras, estantes de cocinas, entre otros. Su mercado potencial son las personas mayores de 25 años, económicamente activas y que habitan en las ciudades de Managua, Masaya y Granada
Immunity related genes in dipterans share common enrichment of AT-rich motifs in their 5' regulatory regions that are potentially involved in nucleosome formation
<p>Abstract</p> <p>Background</p> <p>Understanding the transcriptional regulation mechanisms in response to environmental challenges is of fundamental importance in biology. Transcription factors associated to response elements and the chromatin structure had proven to play important roles in gene expression regulation. We have analyzed promoter regions of dipteran genes induced in response to immune challenge, in search for particular sequence patterns involved in their transcriptional regulation.</p> <p>Results</p> <p>5' upstream regions of <it>D. melanogaster </it>and <it>A. gambiae </it>immunity-induced genes and their corresponding orthologous genes in 11 non-melanogaster drosophilid species and <it>Ae. aegypti </it>share enrichment in AT-rich short motifs. AT-rich motifs are associated with nucleosome formation as predicted by two different algorithms. In <it>A. gambiae </it>and <it>D. melanogaster</it>, many immunity genes 5' upstream sequences also showed NFκB response elements, located within 500 bp from the transcription start site. In <it>A. gambiae</it>, the frequency of ATAA motif near the NFκB response elements was increased, suggesting a functional link between nucleosome formation/remodelling and NFκB regulation of transcription.</p> <p>Conclusion</p> <p>AT-rich motif enrichment in 5' upstream sequences in <it>A. gambiae, Ae. aegypti </it>and the <it>Drosophila </it>genus immunity genes suggests a particular pattern of nucleosome formation/chromatin organization. The co-occurrence of such motifs with the NFκB response elements suggests that these sequence signatures may be functionally involved in transcriptional activation during dipteran immune response. AT-rich motif enrichment in regulatory regions in this group of co-regulated genes could represent an evolutionary constrained signature in dipterans and perhaps other distantly species.</p
Propuesta en Supply Chain Management y Logística en la empresa Esgrim.
En la actualidad el mundo empresarial ha tenido una evolución y un cambio paradigmático gracias a la revolución tecnológica e industrial en la que nos encontramos envueltos. A partir de estos escenarios contemporáneos las empresas necesariamente han tenido que ir mejorando e incorporando sustancialmente diferentes procesos y estrategias modernas que gracias a los diversos aportes que podemos encontrar con la implementación del modelo de supply chain management han transformado el uso de recursos y herramientas en una empresa permitiendo alcanzar el objetivo principal de las redes de valor, aprovechando el potencial de nuevos vínculos, alianzas y procesos que facilitan la sincronización de información y la integración entre los proveedores, distribuidores y clientes finales.
La recopilación de este trabajo tiene como objetivo ofrecer un acercamiento global a los temas más importantes de la propuesta realizada en supply chain management y logística orientada y desarrollada a la empresa esgrim. En ese sentido, el grupo colaborativo procede a realizar la escogencia de la empresa, partiendo del conocimiento de la estrategia corporativa y el enfoque de la organización que ofrece estrategias y soluciones integrales e innovadoras en gestión de riesgos, calidad y ambiente, buscando superar las necesidades y expectativas de sus clientes y principales aliados, ubicados en los diferentes sectores económicos; soportado en un equipo de profesionales especializados, con amplio conocimiento y experiencia, y en alianzas con entidades estratégicas.
Esta propuesta demostró la pertinencia de incorporar este método de supply chain management y logística en las organizaciones que mejorara significativamente su estructura interna porque permitirá su evolución y los hará perdurables en el tiempo adaptándose a las necesidades del mercado actual con el desarrollo tecnológico, gracias a la buena gestión de la cadena de suministros la cual desarrollara una ventaja competitiva sostenible.
Por su parte, los inventarios se consideran como la cantidad con que se dispone de un producto o material. Partiendo del hecho que la demanda no es constante en el tiempo, ninguna empresa tiene certeza de la cantidad de productos que va a vender un día cualquiera, pero si puede realizar pronósticos al respecto. Lo ideal es que se debe dar un equilibrio entre los productos que más se venden y los que no, pues para cualquier negocio es fundamental tener un buen flujo de caja, es decir, las empresas quieren y necesitan que sus productos se vendan rápido y así poder pagar puntualmente a sus proveedores, préstamos, entre otros.
Por otro lado, al analizar el conjunto de elementos que interactuan en cualquier organización que coadyuvan a lograr sus objetivos, se pueden tener en cuenta dos opciones: el modelo SCOR del Supply Chain Council y el modelo GSCF de Supply Chain Forum. El primero con 5 procesos busca la colaboración entre las empresas cuya experiencia permite que dicho modelo evolucione con el tiempo. Mientras que el segundo con 8 procesos, se enfoca en la reducción de costos y aumento en la utilidad mediante una armoniosa relación entre los clientes y proveedores en pro de diseñar toda la red y monitorear las actividades claves que generen valor a dicha red.Today the business world has undergone an evolution and a paradigmatic shift thanks to the technological and industrial revolution in which we are involved. From these contemporary scenarios, companies have necessarily had to improve and substantially incorporate different modern processes and strategies that, thanks to the various contributions that we can find with the implementation of the supply chain management model, have transformed the use of resources and tools into a company allowing the main objective of value networks to be achieved, taking advantage of the potential of new links, alliances and processes that facilitate the synchronization of information and integration between suppliers, distributors and end customers.
The compilation of this work aims to offer a global approach to the most important issues of the proposal made in supply chain management and logistics oriented and developed to the fencing company. In this sense, the collaborative group proceeds to make the choice of the company, based on the knowledge of the corporate strategy and the approach of the organization that offers comprehensive and innovative strategies and solutions in risk management, quality and environment, seeking to overcome the needs and expectations of its clients and main allies, located in the different economic sectors; supported by a team of specialized professionals, with extensive knowledge and experience, and in alliances with strategic entities.
This proposal demonstrated the relevance of incorporating this method of supply chain management and logistics in organizations that would significantly improve their internal structure because it will allow their evolution and will make them durable over time, adapting to the needs of the current market with technological development, thanks to the good management of the supply chain which will develop a sustainable competitive advantage.
For its part, inventories are considered as the quantity with which a product or material is available. Based on the fact that demand is not constant over time, no company is certain of the number of products it will sell on any given day, but it can make forecasts about it. Ideally, there should be a balance between the products that are sold the most and those that do not, because for any business it is essential to have a good cash flow, that is, companies want and need their products to sell quickly and thus to be able to pay their suppliers, loans, among others on time.
On the other hand, when analyzing the set of elements that interact in any organization that contribute to achieving its objectives, two options can be taken into account: the SCOR model of the Supply Chain Council and the GSCF model of the Supply Chain Forum. The first with 5 processes seeks collaboration between companies whose experience allows this model to evolve over time. While the second with 8 processes, focuses on reducing costs and increasing profits through a harmonious relationship between customers and suppliers in order to design the entire network and monitor the key activities that generate value to said network
Impacto do aquecimento global no custo de produção de carne bovina no Brasil
Global warming is affecting agribusiness in its economic aspects. Therefore, the prediction of the evolution of Brazilian beef cattle production cost was made using the IPCC forecast scenario for global warming. The methodology consisted of two steps: (i) the development of a fuzzy model that estimated the grazing land capacity (RP) decrease risk as a function of the changes in the average total rain index, air temperature and increase in extension of the dry season; and (ii) the design of an algorithm for predicting the decrease in production as function of the RPfuzzy model, that results in the impact in beef cattle productivity, and consequent increase in production costs. Historical environmental data from important producing counties in the Cerrado were organized and a set of fuzzy Gaussian functions were developed, and three possible settings (optimistic, medium and pessimistic) were considered. The decrease in beef cattle productivity was estimated using the losses in production due to the increase in air temperature and vulnerability of pasture capacity. The boundary settings for the total increase of production cost scenario used the number of animals per area of grazing land, the adoption of grain supplement and its future scenario; and the result output function pointed to a threshold within a variation from an increase in production cost of 80% (optimistic) to 160% (pessimistic). Under the optimistic scenario the total cost of Brazilian beef cattle production in the Cerrado became near to US 4.16 kg-1, challenging the international competitiveness of this economic segment.O aquecimento global afeta o agronegócio em seus aspectos econômicos. Foi feita previsão daevolução do custo de produção de carne bovina brasileira usando a predição de aquecimento global do IPCC. A metodologia consistiu de duas etapas: (i) o desenvolvimento de modelo fuzzy que estimou o risco de decréscimo da capacidade de pastagens (RP) em função das mudanças no índice pluviométrico total, na temperatura do ar e na extensão da estação de seca; e (ii) o desenvolvimento de um algoritmo para predição do decréscimo da produção em função de um modelo fuzzy de RP que resulte no impacto na produtividade bovina de corte e conseqüente aumento no custo de produção. Foram organizados os dados históricos de fatores ambientais dos municípios importante produção no Cerrado e um conjunto de funções Gaussianas fuzzy foi desenvolvido e três estimativas possíveis (otimista, média e negativa) foram consideradas. O decréscimo na produtividade do gado foi estimado usando as perdas de produção devido ao acréscimo da temperatura bem como da vulnerabilidade da capacidade de pastagem. O estabelecimento dos limites para o cenário do acréscimo do custo de produção usou o número de unidade animal por área de pastagem, a adoção de suplemento de grãos e o cenário de produção futura; e o resultado da função de saída apontou para uma variação do acréscimo do custo de produção de 80% (otimista) até 160% (pessimista). Sob o cenário otimista, o custo total da produção brasileira de carne bovina no Cerrado chega a US 4,16 kg-1, o que pode comprometer a competitividade internacional do setor
Intraoperative radiotherapy electron boost followed by moderate doses of external beam radiotherapy in resected soft-tissue sarcoma of the extremities
To analyze the patterns of failure and the toxicity profile of
intraoperative electron beam radiotherapy (IOERT) after resection of soft tissue
sarcomas of the extremities (STS). PATIENTS AND METHODS: Forty-five patients with
extremity STS were treated with IOERT and moderate-dose postoperative
radiotherapy (45-50 Gy). Twenty-six patients were treated for primary disease
(PD) and 19 patients for an isolated recurrence (ILR). Tumor size was >5 cm
(maximum diameter) in 36 patients (80%), and high-grade histology in PD patients
was present in 14 patients (54%). In nine patients, IOERT was used alone, due to
previous irradiation or patient refusal. Chemotherapy (neoadjuvant and/or
adjuvant) was mainly given to high-grade tumors. RESULTS: Nine patients relapsed
in the extremity (20%), and 12 patients in distant sites (28%). Actuarial local
control at 5 years was 88% for patients with negative/close margins and 57% for
patients presenting positive margins (P=0.04). Five patients (11%) developed
neuropathy associated with the treatment. Extremity preservation was achieved in
40 patients (88%). With a median follow-up of 93 months (range: 27-143 months)
for the patients at risk, 25 patients remain alive (a 7-year actuarial survival
rate of 75% for PD and 47% for ILR; P=0.01). CONCLUSIONS: IOERT combined with
moderate doses of external beam irradiation yields high local control and
extremity preservation rates in resected extremity STS. Peripheral nerves in the
IOERT field are dose-limiting structures requiring a dose compromise in the IOERT
component to avoid severe neurological damage
Do Clinical Trials Meet Current Care Needs? Views of Digestive Oncology Specialists in Galicia (Spain) Using the Delphi Method
Background: In recent years, abundant scientific evidence has been generated based on clinical trials (CT) in the field of oncology. The general objective of this paper is to find out the extent to which decision making is based on knowledge of the most recent CT. Its specific objectives are to pinpoint difficulties with decision making based on the CT performed and find out the motivations patients and clinicians have when taking part in a CT. Methodology: Combined, prospective study, based on the Delphi method. A lack of correspondence between the people who take part in CT and patients who come for consultation has been identified. A need for training in analysing and interpreting CT has also been identified and a lack of trust in the results of CT financed by the pharmaceutical industry itself has been perceived. Conclusions: There is a difficulty in selecting oncological treatment due to the lack of correspondence between the patients included in the CT and patients seen in consultation. In this process, real world data studies may be highly useful, as they may provide this group with greater training in interpreting CT and their results.S
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