Idealised Antenna Functions for Higher Order QCD Calculations

In this thesis, the infrared structure of squared matrix elements in quantum chromodynamics (QCD) is scrutinised. Specifically, the triple-collinear splitting functions are decomposed and improvements to antenna subtraction are sought through the construction of idealised antenna functions. The antenna-subtraction technique has demonstrated remarkable effectiveness in handling next-to-next-to-leading order (NNLO) infrared divergences for a wide range of QCD processes relevant for colliders. However, since antenna functions were historically extracted from matrix elements, they did not have uniform properties, which made the generation of subtraction terms complex. Antenna subtraction up to NNLO is reviewed, including the role of antenna functions. A general algorithm is detailed in order to re-build antenna functions, with idealised features, directly from a specified list of unresolved limits, for any number of real and virtual emissions. Using this general algorithm, together with the decomposition of the triple-collinear splitting functions, all the antenna functions required for NNLO QCD calculations in the final-final configuration are constructed and it is demonstrated that they form a consistent NNLO subtraction scheme. The idealised antenna functions should simplify the generation of subtraction terms and minimise the introduction of spurious limits. Additionally, the general algorithm sets out an initial blueprint for next-to-NNLO (N$^3$LO) idealised antennae for use in N$^3$LO QCD calculations

Factors influencing transfusion-associated HLA sensitization in patients bridged to heart transplantation using ventricular assist device.

BackgroundBridging heart failure patients with mechanical ventricular assist devices (VAD) enables access to transplantation. However, VAD is associated with increased risk for anti-HLA antibodies associated with rejection of subsequent allografts. Factors determining alloantibody formation in these patients remain undefined.MethodsWe performed a single-center retrospective cohort study of 164 patients undergoing heart transplantation from 2014 to 2017. Medical records including use of VAD, transfused blood products, anti-HLA antibody testing, crossmatch, and time to transplant were evaluated.ResultsPatients received an average of 13.8 red blood cell and 1.9 single-donor platelet units associated with VAD. There was a 28.7% increase in the incidence of anti-HLA antibodies after VAD. Development of anti-HLA antibodies did not correlate with volume or type of blood products, but with pre-VAD HLA sensitization status; relative risk of new alloantibodies in patients with pre-VAD antibodies was 3.5-fold higher than those without prior antibodies (P = .008). Development of new anti-HLA antibodies was associated with an increased time to transplant (169 vs 330 days, P = .013).ConclusionsOur findings indicate that the presence of anti-HLA antibodies pre-VAD was the most significant risk factor for developing additional antibodies post-VAD, suggesting that a subset of patients may be predisposed to alloantibody formation

Mild hypothermia does not attenuate platelet aggregation and may even increase ADP-stimulated platelet aggregation after clopidogrel treatment

<p>Abstract</p> <p>Background</p> <p>Mild hypothermia is currently standard of care for cardiac arrest patients in many hospitals and a common belief is that hypothermia attenuates platelet aggregation. We wanted to examine the effects of clopidogrel on platelet aggregation during hypothermia.</p> <p>Methods</p> <p>Platelet reactivity at 37°C and 33°C was evaluated by light transmission aggregometry and vasodilator-stimulated phosphoprotein (VASP) in blood from healthy volunteers before, and 24 hours after, a 600 mg loading dose of clopidogrel.</p> <p>Results</p> <p>Collagen, 5-HT, epinephrine, U46619 and ADP-induced platelet aggregation was unaltered or even increased by hypothermia. After clopidogrel, there was a significant increase in platelet aggregation for 5 and 20 μM ADP at 33°C compared to 37°C (46 ± 5 vs. 34 ± 5% and 58 ± 4 vs. 47 ± 4%, p < 0.001, n = 8). Hypothermia also increased ADP-induced aggregation after pretreatment with the P2Y₁antagonist MRS2500. The decreased responsiveness to clopidogrel during hypothermia could be overcome by addition of the reversible P2Y₁₂antagonist AZD6140. ADP-induced inhibition of VASP-phosphorylation was unaffected by hypothermia both in the presence and absence of clopidogrel. A dose-response curve for ADP-induced platelet aggregation revealed increased potency for ADP during hypothermia with no difference in efficacy.</p> <p>Conclusion</p> <p>Mild hypothermia did not attenuate platelet aggregation, instead it even increased ADP-stimulated platelet aggregation after clopidogrel treatment. Dual platelet inhibition with aspirin and a P2Y₁₂receptor antagonist is probably needed for patients with acute coronary syndromes treated with mild hypothermia, and it is possible that future ADP blockers could be of benefit.</p

Entropic equality for worst-case work at any protocol speed

We derive an equality for non-equilibrium statistical mechanics in finite-dimensional quantum systems. The equality concerns the worst-case work output of a time-dependent Hamiltonian protocol in the presence of a Markovian heat bath. It has has the form "worst-case work = penalty - optimum". The equality holds for all rates of changing the Hamiltonian and can be used to derive the optimum by setting the penalty to 0. The optimum term contains the max entropy of the initial state, rather than the von Neumann entropy, thus recovering recent results from single-shot statistical mechanics. Energy coherences can arise during the protocol but are assumed not to be present initially. We apply the equality to an electron box.Comment: 4 page + 14 page appendix; 8 figures; AA

A general algorithm to build real-radiation antenna functions for higher-order calculations

The antenna subtraction method has been successfully applied to a wide range of processes relevant for the Large Hadron Collider at next-to-next-to-leading order in αs (NNLO). We propose an algorithm for building antenna functions for any number of real emissions from an identified pair of hard radiator partons directly from a specified list of unresolved limits. We use the algorithm to explicitly build all single- and double-real QCD antenna functions and compare them to the previous antenna functions, which were extracted from matrix elements. The improved antenna functions should be more easily applicable to NNLO subtraction terms. Finally, we match the integration of the antenna functions over the final-final unresolved phase space to the previous incarnation, serving as an independent check on our results

A general algorithm to build mixed real and virtual antenna functions for higher-order calculations

The antenna-subtraction technique has demonstrated remarkable effectiveness in providing next-to-next-to-leading order in αs (NNLO) predictions for a wide range of processes relevant for the Large Hadron Collider. In a previous paper [1], we demonstrated how to build real-radiation antenna functions for any number of real emissions directly from a specified list of unresolved limits. Here, we extend this procedure to the mixed case of real and virtual radiation, for any number of real and virtual emissions. A novel feature of the algorithm is the requirement to match the antenna constructed with the correct unresolved limits to the other elements of the subtraction scheme. We discuss how this can be achieved and provide a full set of real-virtual NNLO antenna functions (together with their integration over the final-final unresolved phase space). We demonstrate that these antennae can be combined with the real-radiation antennae of ref. [1] to form a consistent NNLO subtraction scheme that cancels all explicit and implicit singularities at NNLO. We anticipate that the improved antenna functions should be more amenable to automation, thereby making the construction of subtraction terms for more complicated processes simpler at NNLO

A general algorithm to build mixed real and virtual antenna functions for higher-order calculations

The antenna-subtraction technique has demonstrated remarkable effectiveness in providing next-to-next-to-leading order in $\alpha_s$ (NNLO) predictions for a wide range of processes relevant for the Large Hadron Collider. In a previous paper [1], we demonstrated how to build real-radiation antenna functions for any number of real emissions directly from a specified list of unresolved limits. Here, we extend this procedure to the mixed case of real and virtual radiation, for any number of real and virtual emissions. A novel feature of the algorithm is the requirement to match the antenna constructed with the correct unresolved limits to the other elements of the subtraction scheme. We discuss how this can be achieved and provide a full set of real-virtual NNLO antenna functions (together with their integration over the final-final unresolved phase space). We demonstrate that these antennae can be combined with the real-radiation antennae of Ref. [1] to form a consistent NNLO subtraction scheme that cancels all explicit and implicit singularities at NNLO. We anticipate that the improved antenna functions should be more amenable to automation, thereby making the construction of subtraction terms for more complicated processes simpler at NNLO.Comment: 43 pages; matches version published in JHE

The Tribe Dysoniini Part V: The group Paraphidniae, with Three New Species from Guatemala and Ecuador (Orthoptera: Tettigoniidae: Phaneropterinae)

The moss-and-lichen mimic katydids of the group treated here are easily recognized by their long and slender wings held upward at an almost 45-degree angle. They live in rainforests of central and northern South America, with one species ranging southward to subtropical forest in NE Argentina. Here the recently introduced subgenus Anaphidna is raised to genus beside Paraphidnia, and three additional species are described: P. brevicristata n. sp. and P. tunki n. sp. from Ecuador, the latter along with the relatively complex male calling song, as well as A. obrieni n. sp. from Guatemala. P. gallina is redescribed. A key for the three species of Paraphidnia s. str. is included.Las esperanzas del grupo Paraphidniae que imitan musgo y líquenes son estudiadas en la presente contribución, estas se reconocen fácilmente por sus alas largas y delgadas que se proyectan hacia arriba en un ángulo cercano a los 40 o 45 grados. Estas son habitantes de las selvas tropicales de América Central y el norte de América del Sur, con una especie que llega hasta el sur, en el bosque subtropical del noreste de Argentina. El subgénero Anaphidna es elevado a la categoría de género, junto a Paraphidnia. Se redescribe a P. gallina y se describen tres nuevas especies: P. brevicristata n. sp. y P. tunki n. sp. provenientes del Ecuador, y A. obrieni n. sp. de Guatemala. También se describe el canto relativamente complejo del macho para P. tunki n. sp. Una clave para las actuales tres especies del género Paraphidnia es incluida.Facultad de Ciencias Naturales y Muse

La extensión universitaria en el desarrollo de las pymes porcinas

En razón de la naturaleza de los sistemas pecuarios en manos de pequeños y medianos productores, es prioritario que las actividades de extensión universitaria para el desarrollo de pymes porcinas sean realizadas con absoluta seriedad y responsabilidad. La lógica indica que es la investigación quien brinda datos precisos de las variables relevantes en este sector productivo para realizar una correcta intervención en los desarrollos locales. La extensión universitaria debe tener como meta la transformación de realidades. Para que ello suceda resulta necesario mantener un eje coherente de retroalimentación entre la investigación, la extensión y la docencia universitaria. Durante años se vinculó de manera marginal la extensión con respecto a las demás funciones del ámbito universitario, lo que dio como resultado una escasez de recursos para operar esta función básica, una vinculación débil con la docencia y la investigación, y un bajo nivel de calidad en sus productos y servicios.Fil: Braun, Rodolfo Oscar. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Ghiglione, Franco Alexis. Universidad Nacional de La Pampa. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Modelo de avaliação sistêmica na gestão integral de pequenas e médias empresas suinícolas

El presente artículo de investigación aborda en forma sistémica las problemáticas intrínsecas propias de la gestión cotidiana de las pequeñas y medianas empresas porcinas en la región semiárida de la provincia de La Pampa, Argentina. Mediante la utilización metodológica de un estudio de caso, bajo la óptica del Cuadro de Mando Integral, se construyó un conjunto de cuarenta y dos indicadores agrupados en cuatro perspectivas, los cuales permitieron realizar un adecuado diagnóstico de situación actual y establecer parámetros de mejora continua a mediano y largo plazo, para lograr los diecisiete objetivos estratégicos propuestos. El documento tiene como objeto presentar una metodología de evaluación genérica que pueda replicarse con éxito en otras empresas vinculadas a la cadena agroalimentaria porcina, teniendo en cuenta las particularidades de cualquier organización que desarrolla actividades productivas.This research article aproaches in a systematic way the intrinsic problems typical of the daily management of small and medium-sized pig companies in the semi-arid region of the province of La Pampa, Argentina. Through the methodological use of a case study, from the point of view of the Balanced Scorecard, a set of indicators was constructed, grouped into four perspectives, which allowed to develop an adequate diagnosis of the current situation and to establish parameters for continuous improvement in the medium and long term. deadline to achieve the proposed strategic objectives. The document aims to present a generic evaluation methodology, which can be successfully replicated in other companies related to the pig agrifood chain, taking into account the particularities of any organization that develops productive activities.Este artigo de pesquisa aborda sistematicamente os problemas intrínsecos da gestão cotidiana de pequenas e médias empresas suinícolas do semiárido da província de La Pampa, Argentina. Por meio da utilização metodológica de um estudo de caso, na perspectiva do Balanced Scorecard, foi construído um conjunto de quarenta e dois indicadores agrupados em quatro perspectivas, o que permitiu um diagnóstico adequado da situação atual e estabelecer parâmetros de melhoria contínua para médio e longo prazo, para atingir os dezessete objetivos estratégicos propostos. O objetivo do documento é apresentar uma metodologia de avaliação genérica que possa ser replicada com sucesso em outras empresas vinculadas à cadeia agroalimentar suína, levando em consideração as particularidades de qualquer organização que desenvolva atividades produtivas.Fil: Ghiglione, Franco Alexis. Universidad Nacional de La Pampa. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Braun, Rodolfo Oscar. Universidad Nacional de La Pampa. Facultad de Agronomía; Argentin