In Defence of Transcendentism

How do objects persist through time? According to endurantism, objects persist through time and do not have temporal parts. According to the transcendentist version of endurantism, objects exist at times by participating in events that occur at those times. This version of transcendentism offers specific metaphysical and semantical advantages over other versions of endurantism. In this paper, we defend transcendentist endurantism against a series of criticisms that have been recently offered by Kristie Miller.     

Polyamine concentration, transglutaminase activity and changes in protein synthesis during cryopreservation of shoot tips of apple variety Annurca

Changes in metabolism and protein expression were analysed during cryopreservation of the ancient apple variety Annurca. Our experiments concerned transglutaminase activity, polyamine levels and protein expression associated with shoot tip dehydration. Cryopreserved shoot tips displayed 72% regrowth after treatment in liquid medium with 0.75 M sucrose for 1 day followed by dehydration to 19% moisture content (fresh weight basis). After dehydration, the concentration of polyamines putrescine and spermidine decreased compared with untreated controls, while spermine concentration remained unaffected. Transglutaminase activity was slightly reduced in treated samples, while post-thaw regrowth enzyme activity approached control values. We also detected significant changes in protein expression profiles and identified six proteins related with stress response or involved in the slowing down of the cell cycle. The relationship between biochemical parameters, protein synthesis and cryotolerance is discussed.     

Parameterizing correlations: a geometric interpretation

^** Email: francesco.rapisarda{at}ubs.com In this paper, we present a new interpretation of the parameterizationof a correlation matrix proposed earlier by some authors (Jäckel& Rebonato, 1999). This interpretation is based on viewingany correlation matrix as the result of the scalar productsof a suitable set of unit vectors in a multidimensional space,each rotated from all the others by generalized Euler angles.It is possible to exploit the intuitive nature of this approachin order to obtain more efficient optimization schemes whencalibrating a reduced-form model to a desired correlation structure.     

Luminescent silica nanoparticles: extending the frontiers of brightness

Silica nanoparticles are versatile platforms with many intrinsic features, such as low toxicity. Proper design and derivatization yields particularly stable colloids, even in physiological conditions, and provides them with multiple functions. A suitable choice of dyes and synthetic strategy may, in particular, yield a very bright nanosystem. Silica nanoparticles thus offer unique potential in the nanotechnology arena, and further improvement and optimization could substantially increase their application in fields of high social and economic impact, such as medical diagnostics and therapy, environmental and food analysis, and security. This paper describes silica-based, multicomponent nanosystems with intrinsic directional energy- and electron-transfer processes, on which highly valued functions like light harvesting and signal amplification are based.     

Release and speciation of uranium in low-ionic-strength groundwaters at an abandoned uranium mine in Val Vedello (Orobic Alp—Italy) by adsorptive cathodic stripping voltammetry

Adsorptive cathodic stripping voltammetry (AdCSV) with HDME and a chloranilic acid ligand was used in the trace analysis of uranyl ions at pH?=?2 in low-ionic-strength groundwaters around mining areas. Upon optimization, the limit of detection around 0.10?µg?L^?1 was found with linearity up to 10?µg?L^?1. In the abandoned mining area of Val Vedello (Orobic Alps, Italy), measured uranium concentrations in water ranged from 0.3?µg?L^?1 above the uranium mineralization levels to 145?µg?L^?1 in groundwaters percolating from mine galleries. Such uranium concentrations are related to natural weathering effects of CO₂ and/or hydrogen carbonate ion on uranium mineralizations under oxic conditions. A marked seasonal dependence was then found, in agreement with literature data on a pre-operational survey dating back to 1980–1981. No significant chemical impact of the abandoned mining activity on groundwater quality could be found. Accordingly, no significant increase in contaminants derived from the heat-burn of explosives, such as chloride and nitrate, in groundwaters from mine galleries was found.     

Design and development of a low cost,high performance UV digester prototype: Application to the determination of trace elements by stripping voltammetry

A low cost, high performance ultraviolet digester was developed and tested in our laboratory. Its main features include limited costs (around 600 € for all the parts) and high efficiency toward total organic carbon (TOC) abatement. As a result the TOC of typical natural waters is reduced to less than 10% of its initial value with half an hour treatment. Easiness of use, temperature control and flexibility in sample size (up to 25 mL) and number (up to twelve 12 mL test tube) are other important characteristics of the developed UV digester.This apparatus was tested as a pretreatment method for the determination of the total content of trace elements such as copper, uranium and platinum in natural waters by cathodic adsorptive stripping voltammetry. The voltammetric technique was chosen because it is strongly interfered by the presence of even low levels of natural organic complexing molecules. As a result, a 30 minute UV treatment yielded results non distinguishable from ICP-MS data.     

Mild, convenient and versatile Cu-mediated synthesis of N-aryl-2-imidazolidinones

A mild, general, convenient and practical methodology for the selective copper-mediated mono N-arylation of unprotected 2-imidazolidinone was developed. Strong electron-donating groups and free hydroxy and amino groups on the aryl iodide substrates were well tolerated. The use of n-butanol as the solvent for the copper-catalysed mono-arylation of 2-imidazolidinone is unprecedented.     

Optimal asset allocation aid system: From “one-size” vs “tailor-made” performance ratio

Optimal asset allocation well-fitting investors’ goals is a pressing challenge in risk management. Making a step forward to the Sharpe ratio, the parameter-dependent Sortino–Satchell, Generalized Rachev and Farinelli–Tibiletti performance ratios are suggested for personalizing asset allocation. Tailor-made optimal asset paths for five different investor risk profiles are traced over a rolling 12 month investing horizon. Our simulations show a satisfactorily good match between asset allocation and correspondent risk profile. Specifically, Generalized Rachev ratios outperform in personalized allocation for “extreme” risk profiles, i.e. conservative and aggressive investors, whereas Sortino–Satchell and Farinelli–Tibiletti ratios for those that are more moderate. Sharpe ratio confirms its ability in constructing steady-diversified portfolios, although underperformed.     

Cathodic pseudopolarography: A new tool for the identification and quantification of cysteine,cystine and other low molecular weight thiols in seawater

Thiols are compounds of paramount importance in the cellular metabolism due to their double detoxifying role as radical scavengers and trace metal ligands. However, we have scarce information about their extracellular cycling as limited data are available about their concentration, stability and speciation in the aquatic medium. In natural waters, they form part of the pool of reduced sulfur substance (RSS) whose presence has been documented by voltammetric and chromatographic methods. Traditional use of cathodic stripping voltammetry (CSV) for the analysis of RSS could only give an overall concentration due to the coalescence of their CSV peaks. Recently, it has been shown that the use of multiple deposition potentials could take voltammetry of RSS to a higher level, permitting the identification and quantification of the mixtures of RSS despite showing as a single coalescent peak. Here, due to its similarity with classical pseudopolarography, we propose to rename this analytical strategy as cathodic pseudopolarography (CP) and we present for the first time its use for the analysis of mixes of low molecular weight thiols (LMWT) at the nanomolar level. Despite limitations caused by the identical behavior of some LMWT, the CP allowed to isolate the contribution of cysteine and cystine from a coalescent signal in LMWT mixtures. Sample handling with clean protocols allowed the direct determination of the cystine:cysteine ratio without sample modification. Finally, we show the application of CP to identify LMWT in seawater samples extracted from benthic chambers and suggest future applications in other areas of environmental electroanalysis.     

Adler–Bardeen theorem and manifest anomaly cancellation to all orders in gauge theories

We reconsider the Adler–Bardeen theorem for the cancellation of gauge anomalies to all orders, when they vanish at one loop. Using the Batalin–Vilkovisky formalism and combining the dimensional-regularization technique with the higher-derivative gauge invariant regularization, we prove the theorem in the most general perturbatively unitary renormalizable gauge theories coupled to matter in four dimensions, and we identify the subtraction scheme where anomaly cancellation to all orders is manifest, namely no subtractions of finite local counterterms are required from two loops onwards. Our approach is based on an order-by-order analysis of renormalization, and, differently from most derivations existing in the literature, does not make use of arguments based on the properties of the renormalization group. As a consequence, the proof we give also applies to conformal field theories and finite theories.