One-loop triple collinear splitting amplitudes in QCD

We study the factorisation properties of one-loop scattering amplitudes in the triple collinear limit and extract the universal splitting amplitudes for processes initiated by a gluon. The splitting amplitudes are derived from the analytic Higgs plus four partons amplitudes. We present compact results for primitive helicity splitting amplitudes making use of super-symmetric decompositions. The universality of the collinear factorisation is checked numerically against the full colour six parton squared matrix elements

recent progress in higher order computations for the physics of the higgs boson

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GOSAM-2.0: a tool for automated one-loop calculations within theStandard Model and beyond

We present the version 2.0 of the program pack-ageGoSamfor the automated calculation of one-loop ampli-tudes.GoSamis devised to compute one-loop QCD and/orelectroweak corrections to multi-particle processes withinand beyond the Standard Model. The new code containsimprovements in the generation and in the reduction of theamplitudes, performs better in computing time and numer-ical accuracy, and has an extended range of applicability.The extended version of the “Binoth-Les-Houches-Accord”interface to Monte Carlo programs is also implemented. Wegive a detailed description of installation and usage of thecode, and illustrate the new features in dedicated examples

Event generators for high-energy physics experiments

We provide an overview of the status of Monte-Carlo event generators for high-energy particle physics. Guided by the experimental needs and requirements, we highlight areas of active development, and opportunities for future improvements. Particular emphasis is given to physics models and algorithms that are employed across a variety of experiments. These common themes in event generator development lead to a more comprehensive understanding of physics at the highest energies and intensities, and allow models to be tested against a wealth of data that have been accumulated over the past decades. A cohesive approach to event generator development will allow these models to be further improved and systematic uncertainties to be reduced, directly contributing to future experimental success. Event generators are part of a much larger ecosystem of computational tools. They typically involve a number of unknown model parameters that must be tuned to experimental data, while maintaining the integrity of the underlying physics models. Making both these data, and the analyses with which they have been obtained accessible to future users is an essential aspect of open science and data preservation. It ensures the consistency of physics models across a variety of experiments

Event generators for high-energy physics experiments

We provide an overview of the status of Monte-Carlo event generators for high-energy particle physics. Guided by the experimental needs and requirements, we highlight areas of active development, and opportunities for future improvements. Particular emphasis is given to physics models and algorithms that are employed across a variety of experiments. These common themes in event generator development lead to a more comprehensive understanding of physics at the highest energies and intensities, and allow models to be tested against a wealth of data that have been accumulated over the past decades. A cohesive approach to event generator development will allow these models to be further improved and systematic uncertainties to be reduced, directly contributing to future experimental success. Event generators are part of a much larger ecosystem of computational tools. They typically involve a number of unknown model parameters that must be tuned to experimental data, while maintaining the integrity of the underlying physics models. Making both these data, and the analyses with which they have been obtained accessible to future users is an essential aspect of open science and data preservation. It ensures the consistency of physics models across a variety of experiments

Dissecting the Effects of Concentrated Carbohydrate Solutions on Protein Diffusion, Hydration, and Internal Dynamics

We present herein a thorough description of the effects of high glucose concentrations on the diffusion, hydration and internal dynamics of ubiquitin, as predicted from extensive molecular dynamics simulations on several systems described at fully atomistic level. We observe that the protein acts as a seed that speeds up the natural propensity of glucose to cluster at high concentration; the sugar molecules thus aggregate around the protein trapping it inside a dynamic cage. This process extensively dehydrates the protein surface, restricts the motions of the remaining water molecules, and drags the large-scale, collective motions of protein atoms slowing down the rate of exploration of the conformational space despite only a slight dampening of fast, local dynamics. We discuss how these effects could be relevant to the function of sugars as preservation agents in biological materials, and how crowding by small sticky molecules could modulate proteins across different reaction coordinates inside the cellular cytosol

Dissecting the Effects of Concentrated Carbohydrate Solutions on Protein Diffusion, Hydration, and Internal Dynamics

We present herein a thorough description of the effects of high glucose concentrations on the diffusion, hydration and internal dynamics of ubiquitin, as predicted from extensive molecular dynamics simulations on several systems described at fully atomistic level. We observe that the protein acts as a seed that speeds up the natural propensity of glucose to cluster at high concentration; the sugar molecules thus aggregate around the protein trapping it inside a dynamic cage. This process extensively dehydrates the protein surface, restricts the motions of the remaining water molecules, and drags the large-scale, collective motions of protein atoms slowing down the rate of exploration of the conformational space despite only a slight dampening of fast, local dynamics. We discuss how these effects could be relevant to the function of sugars as preservation agents in biological materials, and how crowding by small sticky molecules could modulate proteins across different reaction coordinates inside the cellular cytosol

Preimplantation Histological Score Associates with 6-Month GFR in Recipients of Perfused, Older Kidney Grafts: Results from a Pilot Study

&lt;b&gt;&lt;i&gt;Background:&lt;/i&gt;&lt;/b&gt; Biopsy-guided selection of older kidneys safely expands the organ pool, and pretransplant perfusion improves the preservation of these fragile organs. Herein, we studied morphofunctional variables associated with graft outcomes in perfused, histologically evaluated older kidneys. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; This single-center prospective cohort pilot study evaluated the relationships between preimplantation histologic scores and renal perfusion parameters during hypothermic, pulsatile, machine perfusion (MP) and assessed whether these morphofunctional parameters associated with GFR (iohexol plasma clearance) at 6 months after transplantation in 20 consecutive consenting recipients of a biopsy-guided single or dual kidney transplant from &amp;#x3e;60-year-old deceased donors. &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; The donor and recipient age was 70.4 ± 6.5 and 63.6 ± 7.9 years (&lt;i&gt;p&lt;/i&gt; = 0.005), respectively. The kidney donor profile index (KDPI) was 93.3 ± 8.4% (&amp;#x3e;80% in 19 cases), histologic score 4.4 ± 1.4, and median (IQR) cold ischemia time 19.8 (17.8–22.8 h; &amp;#x3e;24 h in 5 cases). The 6-month GFR was 41.2 (34.9–55.7) mL/min. Vascular resistances positively correlated with global histologic score (&lt;i&gt;p&lt;/i&gt; = 0.018) at MP start and then decreased from 0.88 ± 0.43 to 0.36 ± 0.13 mm Hg/mL/min (&lt;i&gt;p&lt;/i&gt; &amp;#x3c; 0.001) in parallel with a three-fold renal flow increase from 24.0 ± 14.7 to 74.7 ± 31.8 mL/min (&lt;i&gt;p&lt;/i&gt; &amp;#x3c; 0.001). Consistently, vascular resistance reductions positively correlated with global histologic score (&lt;i&gt;p&lt;/i&gt; = 0.009, &lt;i&gt;r&lt;/i&gt; = −0.429). Unlike KDPI or vascular resistances, histologic score was independently associated with 6-month GFR (beta standardized coefficient: −0.894, &lt;i&gt;p&lt;/i&gt; = 0.005). &lt;b&gt;&lt;i&gt;Conclusions:&lt;/i&gt;&lt;/b&gt; MP safely improves graft perfusion, particularly in kidneys with severe histologic changes that would not be considered for transplantation because of high KDPI. The preimplantation histologic score associates with the functional recovery of older kidneys even in the context of a standardized program of pulsatile perfusion. </jats:p