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In this paper, the solution to a bivariate Appell interpolation problem proposed in a previous work is given. Bounds of the truncation error are considered. Ten new interpolants for real, regular, bivariate functions are constructed. Numerical examples and comparisons with bivariate Bernstein polynomials are considered. [ABSTRACT FROM AUTHOR]

The causal link between ambient PM 2.5 and adverse health effects is still not clear enough, nor it is clear what factors (physical and/or chemical) contribute to PM 2.5 toxicity and by what mechanism(s). With a view on this, we launched the CARE experiment, during which we performed a comprehensive characterisation of the physicochemical properties of fine and ultrafine particles under exposure levels dominated by the urban combustion aerosol, and their toxicological assessment through in-vitro tests (lung epithelia cells cultured at the ALI) directly under ambient conditions, oxidative potential (determined through 2′,7′-dichlorouorescin, OP DCFH ), and human biomonitoring. We already reported about aerosol characterisation, and in-vitro model results during CARE. Building upon these, in this work we assess the combustion aerosol oxidative response through the analysis of consistency between the three independent aerosol oxidative responses obtained, and the exploration of any causality link with the combustion aerosol. This is the first time to our knowledge that combustion related PM 2.5 physicochemical properties and its OP DCFH are compared to the cellular-oxidative response (C-OR) obtained through the PM in-vitro test carried out (for the first time) directly under atmospheric ambient conditions, and to certain biomarkers of oxidative damage to DNA/RNA (8-oxo-7,8-dihydroguanine, 8-oxo-7,8-dihydro-2′-deoxyguanosine and 8-oxo-7,8 - dihydroguanosine). Our results provide a first evidence of a combustion-dependent association between the in vitro C-OR, the PM 2.5 OP DCFH , and the urinary excretion of the 8-Oxo-7,8-dihydroguanosine. Yet this is not a substantial basis for drawing any cause-effect relationship. However, our findings support previous literature suggesting a link between combustion and oxidative response of PM 2.5. Moreover, we add a consistency across completely independent oxidative response measurements with a possible dependence on the combustion traffic-related aerosol. This is a piece of information that may have important implications in the understanding of how combustion sources contribute to oxidative response related diseases. Image 1 [ABSTRACT FROM AUTHOR]

In this paper we use Bernoulli polynomials to derive a new spectral method to find the numerical solutions of second order linear boundary value problems. The proposed method has been applied to several BVPs with Dirichlet, Neumann and mixed types boundary conditions. Numerical examples provide favorable comparisons with other existing methods. [ABSTRACT FROM AUTHOR]

In this work, we characterize the Black Carbon (BC) aerosol in an urban airport vs. urban background environment with the objective to evaluate when and how the ultrafine BC dominates the bulk aerosol. Aerosol optical and microphysical properties were measured in a Mediterranean urban area (Rome) at sites impacted by BC sources including fossil fuels (FF), and biomass burning (BB). Experimental BC data were interpreted through measurement-constrained simulations of BC microphysics and optical properties. A “scheme” to separate the ultrafine BC was experimented on the basis of the relation found between changes in the BC partitioning between Aitken and accumulation mode particles, and relevant changes in particle size distribution and optical properties of the bulk aerosol. This separation scheme, applied to experimental data, proved useful to reveal the impact of airport and road traffic emissions. Findings may have important atmospheric implications. The experimented scheme can help separating different BC sources (FF, BB, “aged” BC) when BC size distributions may be very difficult to obtain (satellite, columnar observations, routine monitoring). Indeed, separating the ultrafine BC from the fine BC may provide significant benefits in addressing BC impact on air quality and climate. [ABSTRACT FROM AUTHOR]

In this paper an efficient numerical method for solving a class of multipoint boundary value problems with special boundary conditions of Birkhoff-type is presented. After a quick reference to Birkhoff-type interpolation polynomial which satisfies the particular conditions, and a result on the existence and uniqueness of solution of the given problem, an algorithm is introduced to find a polynomial that approximates the solution. It is a general collocation method. Then an a priori estimation of the error of this approximation is given. Finally, to show the efficiency and the applicability of the method, numerical results are presented. These numerical experiments provide favourable comparisons with the NDSolve command of Mathematica. [ABSTRACT FROM AUTHOR]

For the numerical solution of high order boundary value problems with special boundary conditions a general procedure to determine collocation methods is derived and studied. Computation of the integrals which appear in the coefficients is generated by a recurrence formula and no integrals are involved in the calculation. Several numerical examples are presented to demonstrate the practical usefulness of the proposed method. [ABSTRACT FROM AUTHOR]

Recently we have introduced a new technique for combining classical bivariate Shepard operators with three point polynomial interpolation operators (Dell'Accio and Di Tommaso, On the extension of the Shepard-Bernoulli operators to higher dimensions, unpublished). This technique is based on the association, to each sample point, of a triangle with a vertex in it and other ones in its neighborhood to minimize the error of the three point interpolation polynomial. The combination inherits both degree of exactness and interpolation conditions of the interpolation polynomial at each sample point, so that in Caira et al. (J Comput Appl Math 236:1691-1707, ) we generalized the notion of Lidstone Interpolation (LI) to scattered data sets by combining Shepard operators with the three point Lidstone interpolation polynomial (Costabile and Dell'Accio, Appl Numer Math 52:339-361, ). Complementary Lidstone Interpolation (CLI), which naturally complements Lidstone interpolation, was recently introduced by Costabile et al. (J Comput Appl Math 176:77-90, ) and drawn on by Agarwal et al. () and Agarwal and Wong (J Comput Appl Math 234:2543-2561, ). In this paper we generalize the notion of CLI to bivariate scattered data sets. Numerical results are provided. [ABSTRACT FROM AUTHOR]

A determinantal form for Δ-Appell sequences is proposed and general properties are obtained by using elementary linear algebra tools. As particular cases of Δ-Appell sequences the sequence of Bernoulli polynomials of second kind and the one of Boole polynomials are considered. A general linear interpolation problem, which generalizes the classical interpolation problem on equidistant points, is proposed. The solution of this problem is expressed by a basis of Δ-Appell polynomials. Numerical examples which justify theoretical results on the interpolation problem are given. [ABSTRACT FROM AUTHOR]

Abstract: For the numerical solution of initial value problems a general procedure to determine global integration methods is derived and studied. They are collocation methods which can be easily implemented and provide a high order accuracy. They further provide globally continuous differentiable solutions. Computation of the integrals which appear in the coefficients are generated by a recurrence formula and no integrals are involved in the calculation. Numerical experiments provide favorable comparisons with other existing methods. [Copyright &y& Elsevier]

Abstract: Economical Runge–Kutta schemes for the numerical solution of Stratonovich stochastic differential equations are proposed. The methods have strong global order 1. Numerical stability is studied and some examples are presented to support the theoretical results. [ABSTRACT FROM AUTHOR]

Abstract: This study presents, for the first time, long-term data of sub-μm particle number size distributions in the particle size range of 14–670 nm in the Mediterranean area of Rome. Data are analysed in terms of possible aerosol populations. A particular “event” including also measurements of nitrous acid mixing ratios in the atmosphere is further analysed. High statistical correlations are established: At daytime, between the unknown HONO formation rate and the product of NO2, , relative humidity, and sub-μm particle surface area concentration. At nighttime, between the volume concentration of the small Aitken mode particles and the HONO mixing ratios. The study would provide information on fine and ultrafine aerosol particle size distribution down to 14 nm in the Mediterranean suburban area of Rome. Besides, it would support previous works which have already provided several evidences for the existence of relations between the sub-μm aerosol populations and HONO. Our conclusions include speculations on possible daytime HONO formation mechanisms on particle surfaces in the accumulation mode size range, and nighttime mass formation mechanisms in common for the small Aitken mode particles and HONO. [ABSTRACT FROM AUTHOR]

A class of polynomials Lk(x), k=1, 2, ... of degree 2k satisfying the differential equation L''k(x)=Lk-1(x) and the initial condition L'k(0)=0 is introduced. A relationship with a particular sequence of Appell polynomials of even degree is given. For any choice of one more boundary condition, a special sequence of polynomials is obtained. Special sequences of these polynomials are the basis of an interpolatory problem related to a fixed linear functional. Some of these polynomials are well known in literature. Finally, the problem of the polynomial expansion in these basis of real C∞ functions is posed. Some examples are given. [ABSTRACT FROM AUTHOR]

The class of polynomials Lk(x), k=1, 2, ..., of degree 2k+1 satisfying the differential equation L''k(x)=Lk-1(x) and the initial condition Lk(0)=0 is introduced. For any choice of one more condition, we have a definite and special sequence of polynomials. The sequences of polynomials related to a linear functional F on C2k+1 are interesting, since they are the basis of a particular non-classic interpolatory problem. [ABSTRACT FROM AUTHOR]

Road transport has become by far the major source of environmental pollution and traffic congestion in urban areas. Though a lot of research has been done to investigate the functional relationship linking air quality and air pollution from transport, a further improvement in the knowing of this relationship is needed. The aim of this study was to analyze this relationship and to develop a more flexible framework to allow communication between transport emissions and air quality concentrations. This paper describes the development of this framework, suggests methodological tools to mitigate its problems and shows its application to the mega-city of Beijing, in P.R. China. The result of implementing this methodology would be a system providing high time/space resolution measurements of both air pollutant concentrations and traffic emissions data, as well as real-time transportation and dispersion modelling of those data. The key advantage of the system proposed would be the runtime integration of modelling, to interpret the data measured, with measurements, to validate the data modelled. The findings from the case-study of Beijing show that the integrated system can link traffic air pollution measurements through various modelling modules in order to automate transport-related air pollution assessment. [Copyright &y& Elsevier]

Abstract: For the numerical solution of boundary value problems a global method, based on two-point Taylor formula is proposed. A Mathematica package to compute approximate solution of BVPs is presented. Numerical examples provide favorable comparisons with other existing methods, especially with respect to accuracy. [Copyright &y& Elsevier]

The concentrations of air pollutants such as nitrogen oxides and ozone characterised by very fast chemical reactions can significantly vary within urban street-canyon due to the short distances between sources and receptor. With the primary objective to analyse this issue, NO, NO2, NO x , O3, BTX, and wind flow field were continuously measured for 1 week at two heights (a street-level yard and a 25-m-high rooftop) in an urban canyon in Suzhou (China). The yard ozone concentrations were found to be up to six times lower than on the roof. Different frequency distributions (FD), dynamical and chemical processes of the pollutant variations from yard to roof are discussed to explain the findings. The predominant factors for the dissimilar pollutant vertical diffusion at the two measurement locations were associated to dissimilar fluid-dynamic and heterogeneous removal effects that likely induced dissimilar ozone chemical processes relative to NO x and BTX precursors. [Copyright &y& Elsevier]

For the numerical solution of the second order nonlinear two-point boundary value problems a family of polynomial global methods is derived. Numerical examples provide favorable comparisons with other existing methods. [ABSTRACT FROM AUTHOR]

It is well-known that Muller’s method for the computation of the zeros of continuous functions has order ≈ 1.84 [10], and does not have the character of global convergence. Muller’s method is based on the interpolating polynomial built on the last three points of the iterative sequence. In this paper the authors take as nodes of the interpolating polynomial the last two points of the sequence and the middle point between them. The resulting method has order p=2 for regular functions. This method leads to a globally convergent algorithm because it uses dichotomic techniques. Many numerical examples are given to show how the proposed code improves on Muller’s method. [ABSTRACT FROM AUTHOR]

In [1], a class of global collocation methods for the numerical solution of systems of nonlinear first-order ordinary differential equations was derived.The favorable comparison with other existing methods stimulated us to study them in depth. So in this paper the equivalent implicit Runge-Kutta methods are derived and their stability is studied. Methods derived in [1] are A-stable at least at up to order 20. [Copyright &y& Elsevier]

In this paper, we prove asymptotic Komleva-type expansions valid for sequences of linear operators {Tn(·)} approximating the identity in supremum norm over the space of the continuous functions. In particular, under suitable mild conditions on the sequence {Tn(·)}, we obtain rational expansions for {Tn(f)} that are of special interest in a numerical analysis context. As special cases of these results, we find asymptotic expansions for exponential-type and De La Valle´e Poussin polynomial operators. The case of the Cesaro sums is discussed in connection with the Komleva theory, but the main asymptotic results are proved by using other tools coming from a context of structured linear algebra. Some numerical applications of the theoretical part are then discussed. [Copyright &y& Elsevier]

Air pollution and particulate matter (PM) are the leading environmental cause of death worldwide. Exposure limits have lowered to increase the protection of human health; accordingly, it becomes increasingly important to understand the toxicological mechanisms on cellular models at low airborne PM concentrations which are relevant for actual human exposure. The use of air liquid interface (ALI) models, which mimic the interaction between airborne pollutants and lung epithelia, is also gaining importance in inhalation toxicological studies. This study reports the effects of ALI direct exposure of bronchial epithelial cells BEAS-2B to ambient PM 1 (i.e. particles with aerodynamic diameter lower than 1 μm). Gene expression (HMOX, Cxcl-8, ATM, Gadd45-a and NQO1), interleukin (IL)-8 release, and DNA damage (Comet assay) were evaluated after 24 h of exposure. We report the dose-response curves of the selected toxicological outcomes, together with the concentration-response association and we show that the two curves differ for specific responses highlighting that concentration-response association may be not relevant for understanding toxicological outcomes. Noteworthy, we show that pro-oxidant effects may be driven by the deposition of freshly emitted particles, regardless of the airborne PM 1 mass concentration. Furthermore, we show that reference airborne PM 1 metrics, namely airborne mass concentration, may not always reflect the toxicological process triggered by the aerosol. These findings underscore the importance of considering different aerosol metrics to assess the toxicological potency of fine and ultrafine particles. To better protect human health additional metrics should be defined, than account for the properties of the entire aerosol mixture including specific as particle size (i.e. particles with aerodynamic diameter lower than 20 nm), the relevant aerosol sources (e.g., traffic combustion, secondary organic aerosol ...) as well as their atmospheric processing (freshly emitted vs aged ones). [Display omitted] • Oxidative responses are induced by freshly emitted combustion particles. • DNA damage responses are associated to organic aerosol species. • To be protective for health mass or number metrics must be associated with composition/aging information. • The black carbon to organic carbon ratio is a good proxy for composition/aging and relevant to understanding PM toxicology. • Effects reported as dose-response curves may differ from concentration-response ones. [ABSTRACT FROM AUTHOR]

Two new general classes of polynomial sequences called respectively odd and even Lidstone-type polynomials are considered. These classes include classic Lidstone polynomials of first and second kind. Some characterizations of the two classes are given, including matrix form, conjugate sequences, generating function, recurrence relations, and determinant forms. Some examples are presented and some applications are sketched. [ABSTRACT FROM AUTHOR]

Abstract We address observations of physical and chemical properties of Saharan dust advections (SDA) as observed in the Central Mediterranean basin, within the framework of the LIFE+10, DIAPASON project (www.diapason-life.eu). DIAPASON aimed at the definition of best practices and tools to detect and evaluate the contribution of Saharan dust to ground particulate matter (PM) loads. Polarization-sensitive, automated lidar-ceilometers (PLC) are one of the tools prototyped and used in the Rome area to reach this goal. The results presented in this study focus on: 1) the effectiveness of various observational tools at detecting and characterizing atmospheric dust plumes, and 2) processes and properties of Saharan dust advections reaching the central Mediterranean region. In this respect, the combination of numerical model forecasts and time-resolved (at least hourly) PLC or chemical observations was found to constitute an efficient way to predict and confirm the presence of Saharan dust. In the period 2011–2014, Saharan dust advections were observed to reach over Rome on about 32% of the days. In some 70% of these days the dust reached the ground in dry conditions, while 30% of advection days involved wet deposition. Dry (wet) deposition was found to maximize (minimize) in summer. The northern Sahara between Algeria and Tunisia (Grand Erg Oriental), was confirmed as the most frequent region of origin of the dust mobilized towards central Italy. Secondary source regions include northern Morocco and Libya. On a statistical basis, Saharan advections to Rome were preceded by increasing atmospheric pressure and stability. These conditions were found to favor the accumulation of aerosols related to local emission sources before the SDA reached the ground. Meteorology (precipitation and turbulence in primis) resulted to be an important modulator of PM concentrations during SDAs. Magnitude and timing of these factors should be well considered to correctly evaluate the dust share in PM loads or the related health effects. Saharan advections observed during DIAPASON affected particle concentrations down to diameters of about 0.6–1 μm, with number concentrations peaking at the 2.5 μm diameter range. These advections were associated with a significant increase in Si-rich particles containing a non-negligible fraction of water. Rainfall was observed to preferentially remove dust particles larger than 2 μm, causing a significant depletion in the Ca-rich fraction with respect to the Si-rich one. The increase in PLC depolarization ratios above 5%, as well as the hourly PIXE records of the Si/Ca ratio increasing above 1 were found to represent good markers for the actual presence of Saharan dust particulate matter, when Saharan advection conditions are occurring. Highlights • Saharan dust advections to Europe occur some 33% of the time in central Mediterranean. • Saharan advections are well identified by polarization lidar and numerical model sinergy. • Meteorology is important at modulating dust and pollution properties at receptor sites. • Selective wet-removal processes occur within dust-laden, precipitating clouds. • Polarization lidar-ceilometers provide optimal 24/7 remote-sensing of atmospheric dust. [ABSTRACT FROM AUTHOR]

CD19-targeted chimeric antigen receptor (CAR) T cells have transformed the treatment of patients with relapsed or refractory CD19-positive hematologic malignancies. However, a significant subset of these patients either fails to respond or eventually relapses. Moreover, patients who are candidates for CART-19 therapy often have symptomatic disease that requires some form of treatment to support them during the manufacture period. An ideal bridging therapy would simultaneously both (1) sensitize the tumor to CART-19 attack to increase antitumor control and (2) debulk the disease during manufacture. Radiotherapy (RT) is an established curative and palliative cancer treatment regimen, with approximately half of cancer patients with solid tumors receiving RT sometime during their disease. Several reports have underscored the existence of threshold doses (and regimens) that are able to switch on different damage programs that profoundly affect responses to therapy by eliciting potent immune modulatory effects, prompting immunologically mediated tumor cell death. These effects have been attributed to multiple pathways, including the activation of the cGMP-cAMP Synthetase (cGAS), Stimulator of Interferon Genes (STING) pathway with Type I Interferons expression, and tumor associated antigen (TAA) cross priming with anti-tumor CD8+ T cell elicitation, ultimately inducing "abscopal" effects. By virtue of the immunomodulatory effects of RT, we hypothesize that RT could serve as a successful bridging strategy for CAR T-cell therapy. To investigate this hypothesis, we established the A20 Lymphoma CART-19 therapy mouse model in our lab and used it to perform preliminaries experiments. A20 cells were implanted into both flanks of the animals. Mimicking human immune adjuvant doses used in our institute for RT bridging, 20 days after tumor cell implantation, we radiated one of the two tumors using a dose of 8Gy divided in two fractions of 4Gy each. Twenty-four hours later 1 × 10ep6 CART-19 cells were infused intravenously. While the effects of RT in combination with CART-19 have similar impact on the tumor growth of the irradiated mass, a significant increase of the antitumor effects of the single therapy was observed on the non-irradiated tumor. FACS studies demonstrated heavy leukocyte infiltration with increased presence of infused CART-19 as well indigenous T cells. To investigate possible molecular mechanisms involved in the increased effects on the non-irradiated tumor, we performed a qPCR array and observed increased expression of genes linked to cross priming, including IFN type I and Batf3. A20 cells express the ectopic retroviral antigen gp70 with well characterized AH1 immune-dominant epitope. AH1 tetramer staining on infiltrating T cells demonstrated increased staining in tumor from mice treated with the combination. Overall these results suggest RT may serve as optimal debulking and bridging therapy for CAR-T cell therapy. [ABSTRACT FROM AUTHOR]

In this source apportionment study, an original approach based on receptor modelling was tested to relate primary and secondary organic aerosol (OA) contributions - estimated from ACSM (Aerosol Chemical Speciation Monitor) measurements - to their emission sources. Moreover, thanks to the coupling of optical and chemical variables as input to the receptor model, information such as the impact of mineral dust to the aerosol absorption in the atmosphere and estimates for the absorption Ångström exponent (α) of the sources were retrieved. An advanced source apportionment study using the Multilinear Engine (ME-2) was performed on data collected during February 2017 in Rome (Italy), in the frame of the CARE (Carbonaceous Aerosol in Rome and Environs) experiment. A complete chemical characterisation (elements, non-refractory components, and carbonaceous components) was carried out, and the aerosol absorption coefficients b ap (λ) at 7 wavelengths (370, 470, 520, 590, 660, 880, and 950 nm) were retrieved by an Aethalometer AE33; all these variables (chemical + optical) were used as input to the receptor model. The final constrained solution consisted of nine factors which were assigned to major sources impacting on the investigated site (hereafter sources are referred to as: biomass burning, nitrate and aged aerosol, traffic exhaust, sulphate, mineral dust, marine aerosol, traffic non-exhaust, local source, and polluted marine aerosol), comprising both local urban sources and contributions from long-range transport. The bootstrap analysis supported the goodness of the solution. Total OA concentration from ACSM was apportioned by our receptor model and afterwards compared with HOA (hydrocarbon-like organic aerosol), BBOA (biomass burning-like organic aerosol), and OOA (oxygenated organic aerosol) concentrations obtained as results from an independent source apportionment study previously performed. As an original result of this work, insights on OA contributions were thus retrieved: (1) the contribution of organic aerosol assigned by ME-2 to the traffic exhaust source was fully comparable to HOA assessed by ACSM data analysis; (2) our source apportionment results gave the relevant indication that the OOA apportionment made on ACSM data likely includes a secondary OA contribution due to biomass burning. Other relevant results came from b ap apportionment obtained by our multi-variable source apportionment approach: traffic exhaust was the main contributor to aerosol absorption in the atmosphere, but mineral dust contribution was also notable when a not negligible mineral dust transport episode was registered at the measurement site. In addition, source dependent optical absorption parameters (i.e. the absorption Ångström exponent - α - and the mass absorption cross section at different wavelengths) were retrieved without any a-priori assumption. In perspective, our modelling approach paves the way to more powerful source apportionment approaches which have the potential of providing much more insights on aerosol properties and sources. Image 1 [ABSTRACT FROM AUTHOR]

The "Carbonaceous Aerosol in Rome and Environs" (CARE) experiment took place at a Mediterranean urban background site in Rome (Italy) deploying a variety of instrumentation to assess aerosol physical-chemical and optical properties with high-time resolution (from 1 min to 2 h). In this study, aerosol optical properties, chemical composition, and size distribution data were examined with a focus on the analysis of several intensive optical properties obtained from multi-wavelength measurements of aerosol scattering and absorption coefficients. The spectral behaviour of several quantities related to both aerosol composition and size was explored, analysing their high-time resolved temporal patterns and combining them in order to extract the maximum information from all the available data. A methodology to separate aerosol types using optical data only is here proposed and applied to an urban area characterised by a complex mixture of particles. A key is given to correctly disentangle cases that could not be distinguished observing only one or few parameters, but that can be clearly separated using a suitable ensemble of optical properties. The SSCAAE, i.e. the wavelength dependence of the Single Scattering co-albedo 1-SSA (where SSA is the Single Scattering Albedo) - that efficiently responds to both aerosol size and chemical composition – resulted to be the best optical intensive parameter to look at for the discrimination between episodes characterised by specific aerosol types (e.g. sea salt, Saharan dust) and more mixed conditions dominated by local emissions. However, this study also highlighted that it is necessary to combine temporal patterns of different optical parameters to robustly associate SSCAAE features to specific aerosol types. In addition, the complete chemical speciation and the high-time resolved size distribution were used to confirm the aerosol types identified via a combination of aerosol optical properties. Look-up tables with most suitable ranges of values for optical variables were produced; therefore, these pieces of information can be used at the same site or at locations with similar features to quickly identify the occurrence of aerosol episodes. Graphical frameworks (both from the literature and newly designed) are also proposed; for each scheme features, advantages, and limitations are discussed. • Combination of intensive optical parameters discriminates aerosol types. • High-time resolved composition and size distribution support the identification. • The methodology produces look-up tables useful for real-time implementation. • High PM events origin can be identified by optical parameters only. [ABSTRACT FROM AUTHOR]