BPS Quivers of Five-Dimensional SCFTs, Topological Strings and q-Painlevé Equations

We study the discrete flows generated by the symmetry group of the BPS quivers for Calabi–Yau geometries describing five-dimensional superconformal quantum field theories on a circle. These flows naturally describe the BPS particle spectrum of such theories and at the same time generate bilinear equations of q-difference type which, in the rank one case, are q-Painlevé equations. The solutions of these equations are shown to be given by grand canonical topological string partition functions which we identify with τ-functions of the cluster algebra associated to the quiver. We exemplify our construction in the case corresponding to five-dimensional SU(2) pure super Yang–Mills and Nf= 2 on a circle

Editorial: Grid Connection of Converters in Renewable Applications

Energy generated from renewable sources is fed into the grid by means of electronic power converters. These can be supervised at system (grid) level to coordinate all productions points together with storages and loads. Regulations impose power supply quality requirements regarding harmonics, grid fault response and low voltage ride through (LVRT). The progress of distributed generation presents challenges to converters such as island mode operation, voltage and frequency regulation, simulation, etc. New collaborative solutions for “more smart” microgrids must be included to improve power quality, reliability, service quality and duty. Wind turbines employing double-fed induction generators (DFIG) use two converters, one for the rotor side and one for the generator side. To improve the performance during severe grid failures, in Okedu and Barghash the advantages of using alternative configurations to the two-level converter, such as the parallel interleaved 2-level inverter, and the 3-level inverter, have been investigated. It has also been investigated to replace the classical dq-PLL with a new PLL, and to include a series dynamic braking resistor (SDBR) between the converters and the three-phase connections. Wind turbines must meet strict requirements, in terms of their behavior, in the event of grid failures, which are regulated by the LVRT regulations in each country. These regulations indicate, by means of voltage and time graphs, how long the wind turbines must remain connected depending on the depth of the faults. In addition, the limits of active and reactive power that can be exchanged during faults are established. The aim is to avoid cascading disconnections of wind turbines that would compromise the stability of the grid. In Okedu and Barghash, the effect of various elements in improving the behaviour of a DFIG against grid faults has been investigated. The first of these elements is the parameters of the IGBTs, concluding that the on-resistance has the greatest influence. The second is the use of a new PLL, and the third is the use of a SDBR during a grid failure. It was found that all of them could improve the performance of the generator in the event of a grid failure. When a wind turbine uses a permanent magnet synchronous generator (PMSG), 100% of the energy generated passes through both converters. In Okedu and Barghash, the control systems of the generator-side and grid-side converters have been considered; several scenarios regarding the turn on resistance of the IGBTs have been considered, and their behaviour during grid faults has been analysed. Generator performance has also been studied with and without the use of a DC-DC converter for overvoltage protection. The main generators used in wind turbines are DFIG and PMSG. In Okedu et al., a comparison of the behaviour of both wind turbines against grid faults has been carried out in various scenarios with different values of generator parameters. The number of converters, associated with renewable generation, connected to the grid has increased significantly lately. This can affect the dynamic response, especially during disturbances, but it can also provide new grid support functionalities if information on the oscillation characteristics is available. Through the use of artificial intelligence, in Baltas et al. the abilities to predict and damp electromechanical oscillations have been improved. With the constant increase in the number of wind turbines connected to the grid, it is very important to have the ability to maintain grid frequency control. In Okedu and Barghash, a work has been presented to stabilise the wind farm during periods of wind speed change by using capacitors connected via a DC-DC converter and a grid-connected DC-AC converter. It was concluded that higher values of the DC-DC converter time constant lead to better performances during load transients. A system including two steam turbines and two squirrel cage induction generators was used in the experiments. Microgrids bring power generation closer to the places of consumption to reduce the saturation of distribution lines. They consist of renewable generation, energy storage and fossil fuel generation. They have three levels of control, where the primary level is the closest to the converters, and the tertiary level, the most external and slowest, performs general monitoring functions. The paper (Buraimoh et al.) focuses on the secondary control functions related to grid failure performance. It proposes a distributed control between inverters and is based on fast detection techniques (fast Delayed Signal Cancellation, DSC), with the objective of a fast control of active and reactive power. A robust transition method between fault mode and normal mode is proposed. Accurate coordination and power sharing between distributed energy resources is achieved. Some energy conversion systems are so complex that they are very difficult to build and test in the laboratory. These include the study of high voltage direct current (HVDC) transmission when several modular multilevel converters (MMC) are involved together with DC grid failure protection elements. In Wang et al., a system including a simulated part (two digitally simulated MMC) and a physical part (two MMC) has been experimented with. The coupling between the two parts has been carried out by means of A/D and D/A converters and power amplifiers

Robust snubberless soft-switching power converter using SiC power MOSFETs and bespoke thermal design

A number of harsh-environment high-reliability applications are undergoing substantial electrification. The converters operating in such systems need to be designed to meet both stringent performance and reliability requirements. Semiconductor devices are central elements of power converters and key enablers of performance and reliability. This paper focuses on a DC–DC converter for novel avionic applications and considers both new semiconductor technologies and the application of design techniques to ensure, at the same time, that robustness is maximized and stress levels minimized. In this respect close attention is paid to the thermal management and an approach for the heatsink design aided by finite element modelling is shown

Synthesis and crystal structure of C2/c Ca(Co, Mg)Si2O6 pyroxenes : effect of the cationic substitution on the cell volume

A series of clinopyroxenes along the CaMgSi2O6-CaCoSi2O6 join was synthesized by quenching from melt at 1500\ub0C and subsequent annealing at 1250\ub0C (at 0.0001 GPa). This protocol proved to be the most effective to obtain homogenous, impurity free and stoichiometric pyroxenes as run products. Electron microprobe analyses in energy-dispersive mode were conducted and single-crystal X-ray diffraction data were collected on the Ca(CoxMg1-x)Si2O6 pyroxenes, with x = 0.2, 0.4, 0.5, 0.6; anisotropic structure refinements were performed. The effects of the cation substitution at the M1 site are described at the atomic level. The experimental findings of this study allowed us to extend the comparative analysis of the structural features of pyroxenes with divalent cations at the M1 and M2 sites

CDKN1A upregulation and cisplatin-pemetrexed resistance in non-small cell lung cancer cells

Cisplatin-pemetrexed is a frequently adopted first-line treatment for patients with advanced non-small cell lung cancer (NSCLC) ineligible for biological therapy, notwithstanding its limited efficacy. In the present study, the RAL cell line, an epidermal growth factor receptor (EGFR)-wild-type, p53- and KRAS-mutated model of NSCLC, was used to investigate novel biomarkers of resistance to this treatment. Cells were analyzed 96 h (96 h-post wo) and 21 days (21 days-post wo) after the combined treatment washout. Following an initial moderate sensitivity to the treatment, the cell growth proliferative capability had fully recovered. Gene expression analysis of the resistant surviving cells revealed a significant upregulation of CDKN1A expression in the cells at 96-h post-wo and, although to a lesser extent, in the cells at 21 days-post wo, accompanied by an enrichment of acetylated histone H3 in its promoter region. CDKN1A was also upregulated at the protein level, being mainly detected in the cytoplasm of the cells at 96 h-post wo. A marked increase in the number of apoptotic cells, together with a significant G1 phase block, were observed at 96-h post wo in the cells in which CDKN1A was knocked down, suggesting its involvement in the modulation of the response of RAL cells to the drug combination. On the whole, these data suggest that CDKN1A plays a role in the response to the cisplatin-pemetrexed combination in advanced KRAS-mutated NSCLC, thus suggesting that it may be used as a promising predictive marker

Immunotherapy of mesothelioma: the evolving change of a long-standing therapeutic dream

Pleural mesothelioma (PM) is an aggressive and rare disease, characterized by a very poor prognosis. For almost two decades, the world standard treatment regimen for unresectable PM has consisted of a platinum-based drug plus pemetrexed, leading to an overall survival of approximately 12 months. The dramatic therapeutic scenario of PM has recently changed with the entry into the clinic of immune checkpoint inhibition, which has proven to be an effective approach to improve the survival of PM patients. The aim of the present review is to provide a comprehensive overview of the most promising immunotherapeutic-based strategies currently under investigation for advanced PM

Bionic for training: Smart framework design for multisensor mechatronic platform validation

Home monitoring supports the continuous improvement of the therapy by sharing data with healthcare professionals. It is required when life-threatening events can still occur after hospital discharge such as neonatal apnea. However, multiple sources of external noise could affect data quality and/or increase the misdetection rate. In this study, we developed a mechatronic platform for sensor characterizations and a framework to manage data in the context of neonatal apnea. The platform can simulate the movement of the abdomen in different plausible newborn positions by merging data acquired simultaneously from three-axis accelerometers and infrared sensors. We simulated nine apnea conditions combining three different linear displacements and body postures in the presence of self-generated external noise, showing how it is possible to reduce errors near to zero in phenomena detection. Finally, the development of a smart 8Ws-based software and a customizable mobile application were proposed to facilitate data management and interpretation, classifying the alerts to guarantee the correct information sharing without specialized skills

Phase 2 study of NAB-paclitaxel in SensiTivE and refractory relapsed small cell lung cancer (SCLC) (NABSTER TRIAL)

Background: Despite sensitivity to first-line chemotherapy, most small-cell lung cancer (SCLC) patients relapse. In this setting, topotecan demonstrated modest activity with significant toxicity. Paclitaxel was also active. This study was designed to evaluate activity and safety of nab-paclitaxel in relapsed SCLC. Methods: In this multicentre prospective Phase 2 trial, patients with refractory or sensitive SCLC progressed to first-line platinum-based chemotherapy received nab-paclitaxel 100 mg/smq on days 1, 8, 15 every 4 weeks up to six cycles, progressive disease or intolerable toxicity. Primary endpoint was investigator-assessed objective tumour response. Secondary endpoints were toxicity, progression-free survival (PFS) and overall survival (OS). Results: Of the 68 patients treated, partial response was 8% in the refractory cohort and 14% in the sensitive cohort. Most common toxicities of any grade were fatigue (54%), anaemia (38%), neutropenia (29%), leukopenia (26%) and diarrhoea (21%). Median PFS was similar in both refractory (1.8 months) and sensitive cohorts (1.9 months), while median OS was longer in sensitive one (6.6 versus 3.6 months). Conclusions: Although nab-paclitaxel has shown some modest anti-tumour activity in relapsed SCLC, associated with a favourable toxicity profile, the primary end-point of the study was not met. Clinical Trial registration: Clinical Trial registration number is ClinicalTrials.gov Identifier: NCT03219762

Recursion and Ambiguity: a Linguistic and Computational Perspective

In this chapter I will be concerned with what characterizes human language and the parser that computes it in real communicative situations. I will start by discussing and dismissing Hauser, Chomsky and Fitch's(2002) (HC&F) disputed claim that the "only uniquely human component of the faculty of language" be "recursion". I will substantiate my rejection of HC&F's claims, with the fact that recursion only appears in mature and literate language - an opinion also shared by some papers in a book on recursion by Harry van der Hulst (2010). I will then present in detail Chomsky's proposal - now part of the Minimalist Theory (MT) - of the architecture of the human parser as being based on Phases. I will accept this part of the theory and compare it with the computational architecture contained in a system for deep text understanding called Getaruns (Delmonte,2007;2009). I will then argue in favour of what I regard the peculiar component of human language faculty that is "the ability to associate meaning to deficient propositions and generic linguistic expressions, which are highly ambiguous in their structure”. And this is also due to the presence of recursion (but not only). I will then speak in favour of a parser that takes "context" into account and strives for a "complete" syntactic representation. As to the problem of ambiguity, I will introduce the use of a computational device, a lookahead mechanism, which is presented in association with the need to specify UG parameters characterizing a given language. I will discuss the use of psychologically viable Parsing Strategies implemented in the parser to overcome ambiguity and prevent Garden Path, whenever possible. This will be highlighted by reference to peculiar features associated to different languages, Italian and English. Eventually, I will present a theory that encompasses all my previous proposals and is called LSLT