On the convergence of Nekrasov functions

In this note we present some results on the convergence of Nekrasov partition functions as power series in the instanton counting parameter. We focus on $U(N)$ ${\mathcal N}=2$ gauge theories in four dimensions with matter in the adjoint and in the fundamental representations of the gauge group respectively and find rigorous lower bounds for the convergence radius in the two cases: if the theory is {\it conformal}, then the series has at least a {\it finite} radius of convergence, while if it is {\it asymptotically free} it has {\it infinite} radius of convergence. Via AGT correspondence, this implies that the related irregular conformal blocks of $W_N$ algebrae admit a power expansion in the modulus converging in the whole plane. By specifying to the $SU(2)$ case, we apply our results to analyse the convergence properties of the corresponding Painlev\'e $\tau$-functions.Comment: 1+25 pages, comments welcome. v2 published versio

Virtual Testing of Counterbalance Forklift Trucks: Implementation and Experimental Validation of a Numerical Multibody Model

This study investigates the dynamic behavior of a recently developed counterbalance forklift truck. The final objective is creating virtual testing tools based on numerical multibody models to evaluate the dynamic stresses experienced by the forklift family of interest during a reference operating cycle, defined by the manufacturer\u2019s testing protocols. This work aims at defining sufficiently accurate and easy-to-implement modelling approaches and validation procedures. It focuses on a specific test, namely the passage of a speed-bump-like obstacle at high velocity, which represents one of the most severe conditions within the reference cycle. Indeed, unlike most of the other wheeled vehicles, forklifts typically do not have advanced suspension systems and their dynamic response is significantly affected by ground irregularities. To this end, a preliminary model of the complete forklift, featuring rigid bodies and a simplified tire\u2013ground contact model, is implemented with a commercial software. Experimental tests are conducted on the forklift to measure the vehicle vibrations when running on the obstacle, for model validation purposes. After model updating, the results provided by the numerical simulations match the experimental data satisfactorily. Hence, the modelling and validation strategies are proven viable and effective

Supply Chain and Virtual Enterprises: the Beer Game evolution

Our aim is to create a simulation based on the rules of the Beer Game which includes the variables of a virtual enterprise, VirtuE in particular, and risk management, in order to understand the strategies underlying the subjects behavior in the face of risk within a means-end chain. This study shows the tests carried out on the original game, the variables that we proposed and the simulation results

From Supply Chains to Supply Networks: the Beer Game evolution

The new trends in inter-organisation configurations are challenging the traditional concept of supply chain. Concepts such as Virtual Enterprise have been introduced to describe scenarios in which manufacturers operate as nodes in a network of suppliers, customers, engineers, and other specialised service functions Our aim is to create a simulation based on the rules of the Beer Game which includes the variables of a virtual enterprise, VirtuE in particular, and risk management, in order to understand the strategies underlying the subjects behavior in the face of risk within a means-end chain. This study shows the tests carried out on the original game, the variables that we proposed and the simulation results.The new trends in inter-organisation configurations are challenging the traditional concept of supply chain. Concepts such as Virtual Enterprise have been introduced to describe scenarios in which manufacturers operate as nodes in a network of suppliers, customers, engineers, and other specialised service functions Our aim is to create a simulation based on the rules of the Beer Game which includes the variables of a virtual enterprise, VirtuE in particular, and risk management, in order to understand the strategies underlying the subjects behavior in the face of risk within a means-end chain. This study shows the tests carried out on the original game, the variables that we proposed and the simulation results.Uninvited Submission

Hybridisation of forklift trucks

In the past years, forklift manufacturers have started to hybridise their products under the worldwide interest toward electrification. This is generally made starting from existing standard products, and converting them into hybrid versions, rather than start from scratch and designing fully new vehicles. This approach involves several gaps from the inaccurate evaluation of the powertrain architecture and relative energy management strategy, up to a rough sizing of components. Therefore, this study suggests a structured methodology to follow, aimed to properly design hybrid forklift trucks. The first step is the analysis of the conventional working machine to hybridise, identifying one set of duty cycles. Then, the design of the new powertrain architecture, with a proper energy management strategy, and the definition of a numerical simulation model realised through a multiphysics object-oriented software package, to properly size the new powertrain components, and to verify energy and power flows. Finally, it is also presented a brief-cost–benefit analysis, as last verification of the proposed methodology, to verify the cost-effectiveness to bring the new products to the market. Results have shown the general feasibility of the operation since the significant reduction in fuel consumption is combined with sustainable costs of the new electrified components

Skin dendritic cells increase in number during early response to wounding

Among the cells that may participate to wound response and wound healing, coordinate with other cell types, dendritic cells have been little studied until now and the least so in humans. This issue has been addressed on samples of wounded and control skin taken at autopsy and analyzed by immunohistochemistry and morphometry. Langerhans cell number in the epidermis and the relative volume of MHC II+ cells in the dermis increased transiently upon wounding, with a significant peak in the first and the second half hour after wounding respectively. Dermal MHC II+ cells became part of a perivascular mononuclear cell infiltrate visible in the subpapillary dermis since between 30 and 60 after wounding and which contained also MC. Cells at the periphery of the infiltrates were also DC-SIGN+ and CD11c+, i.e. were well differentiated connective tissue dendritic cells. Mast cells underwent degranulation associated to an increase in number in the first hours after wounding. These modifications of dendritic cells and mast cells and the respective tissue course suggest that epidermal and dermal dendritic cells participate to the early response to wounding in humans, coordinately with mast cells and possibly stimulating the recruitment and activation of the cells involved in injury response at later time points

Diode-pumped passively mode-locked Yb:YLF laser.

We demonstrate passive mode-locking by means of a semiconductor saturable-absorber mirror in a diode-pumped Yb:YLF laser. We present crystal growth process, spectroscopic measurements, and investigation of mode-locking performance. Pulse trains with minimum duration of 196 fs, average power of 54 mW and a repetition rate of 55 MHz were obtained. The optical spectrum, centered at 1028 nm, has a 7.1-nm bandwidth leading to nearly transform-limited pulses. (C) 2008 Optical Society of America

Cell interactions between mast cells and dendritic cells in human skin wounds

The response to wounding passes through different phases and mast cells (MC) respond to injury since early [1]. These cells can interact with dendritic cells (DC) and lymphocytes in vitro to control immune responses [2], but possible interactions between MC and DC in the early response to wounding in vivo have not yet been investigated. To address this issue, cryosections of skin wounded since 0-24 h taken at autopsy were stained with fluorescent avidin (MC) and UEA-1 (Ulex europaeus-1 lectin: endothelium), and immunolabeled for MHC-II (DC), CD1a (Langerhans cells, i.e. epidermal DC) and PDGF (endothelium). Fluorescence microscopy was followed by computerized image analysis. Intact neighbor skin was used as control. Langerhans cells number increased significantly with a peak 5 min after wounding. The intensity of MHC-II expression and the relative volume of MHC-II+ cells in the dermis increased significantly since 5 min after wounding and remained high for several hours. These cells became part of a perivascular mononuclear cell infiltrate visible in the subpapillary dermis since 60 min after wounding, which contained also MC strictly close to MHC-II positive cells. Upon wounding the number of capillaries labeled by UEA-1 and for PDGF increased markedly. The results suggest that: immature cells residing in the epidermis may come to express CD1a quickly; DC recruitment and redistribution in the dermis may occur quite fast upon injury; the latter cells participate to the response to wounding since the early steps, coordinately with MC and close to capillaries. Therefore DC, together with MC, may be candidate to regulate early injury response in human skin. [1] Bacci et al. J. Forensic. Sci. 2011 (in press) [2] Dudeck et al. Eur. J. Immunol. 2011; doi: 10.1002/eji.201040994

Abdominal Fat Characteristics and Mortality in Rectal Cancer: A Retrospective Study

: The aim of this study was to evaluate the association of adipose tissue characteristics with survival in rectal cancer patients. All consecutive patients, diagnosed with stage II-IV rectal cancer between 2010-2016 using baseline unenhanced Computed Tomography (CT), were included. Baseline total, subcutaneous and visceral adipose tissue areas (TAT, SAT, VAT) and densities (TATd, SATd, VATd) at third lumbar vertebra (L3) were retrospectively measured. The association of these tissues with cancer-specific and progression-free survival (CCS, PFS) was assessed by using competitive risk models adjusted by age, sex and stage. Among the 274 included patients (median age 70 years, 41.2% females), the protective effect of increasing adipose tissue area on survival could be due to random fluctuations (e.g., sub-distribution hazard ratio-SHR for one cm2 increase in SAT = 0.997; 95%confidence interval-CI = 0.994-1.000; p = 0.057, for CSS), while increasing density was associated with poorer survival (e.g., SHR for one Hounsfield Unit-HU increase in SATd = 1.03, 95% CI = 1.01-1.05, p = 0.002, for CSS). In models considering each adipose tissue area and respective density, the association with CSS tended to disappear for areas, while it did not change for TATd and SATd. No association was found with PFS. In conclusion, adipose tissue density influenced survival in rectal cancer patients, raising awareness on a routinely measurable variable that requires more research efforts