Giordano Bruno contro l'abitudine a credere.

"Mi sono messo ancora una volta sulle orme del Nolano e ho scoperto altri sentieri di umanità intrecciata alla sua inquieta filosofia". Così il medico e filosofo napoletano Guido del Giudice parla del suo nuovo libro. L' Acrotismus, un neologismo bruniano che si riferisce alla summa della critica anti-aristotelica del Nolano, viene qui presentato nella sua prima traduzione integrale. Pubblicato a Wittenberg nel 1587, l'opera costituisce la riproposizione ampliata delle tesi discusse dal filosofo a Parigi due anni prima, nel corso di una tumultuosa disputa accademica tenutasi presso il College de Cambrai

Suspect screening of natural toxins in surface water reservoirs

[eng] Natural toxins include a multitude of toxic secondary metabolites produced by animals, bacteria, fungi algae, and plants that are generally not intended as environmental contaminants of concern for water quality. However, the presence of anthropogenic waste in the aquatic environment, both with the climate changes and the increase of temperatures, is creating favorable conditions for the development of undesired organisms able to produce natural toxins that sum with other well known anthropogenic pollutants such as pesticides. Among them, natural toxins produced by algae (cyanotoxins), fungi (mycotoxins), and plants (phytotoxins) are the most encountered in surface water environments. Some of them have various toxic effects on the human body. Carcinogenic, dermotoxic, and neurotoxic effects are generally associated with these compounds. Concern about the effects of cyanobacteria on human health has recently grown in many countries. Several human and livestock poisoning events, due to the contamination of water sources (especially lakes) attributed to toxic cyanobacterial bloom, resulted in a dramatic rise of interest in these toxins. Despite that, their presence in surface water was not evenly regulated, and only the highly toxic microcystin-LR was limited at 1 µg/L by the Drinking Water Directive (Consolidated text: Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption) of the World Health Organization. Additionally, studies on their occurrence, chemical persistence, buoyancy, and the algal blooms onset prediction in the environment are still scarce. The environmental risk assessment is difficult and the degree of toxicity into surface water ecosystems is still poorly studied. Their fate in the environment can be described by distribution coefficients such as the octanol-water partitioning (Kow). Other data able to define other distribution and partition parameters are generally obtained using in-silico prediction tools. The identification and quantification are still difficult due to the availability of certified standards. Moreover, these compounds are found mixed with other groups of chemicals at low concentrations. Most of the published methods for their determination are specifically designed to identify a single compound or a group of toxins with similar characteristics, making stressful and time-consuming the process to identify other known-unknown compounds using non-targeted approaches. Since the dangerousness of natural toxins in surface water was recently reported by different authors, valuable data were produced and published to assess their presence and concentration in surface water environments. Several analytical techniques have been reported for their qualitative and quantitative analysis, among them MALDI- TOF/MS, LC-ESI/HRMS, LC-ESI-QqQ are the most used. However, due to the thousands of compounds and their extreme heterogeneity, suspect screening has taken a central role as screening purposes. Over the years, the suspect screening involved the use of in-silico approaches for the tentative identification of natural toxins, becoming one of the preferred methods for the suspect analysis of known-unknown compounds in surface water. It is of primary importance to develop and optimize new methods able to identify natural toxins in a various range of polarities, ranging from the most hydrophobic to the highest water affine. The screening approaches are generally focused on cyanotoxins with no implementations regarding plant toxins and mycotoxins which are very poorly studied in surface water. In this framework, this thesis has aimed to increase the knowledge about natural toxins in surface water. The first part of the study was focused on the recent advances in the detection of natural toxins retrieving a multitude of analytical approaches for their determination in surface and drinking water. Finally, two suspect screening approaches using suspect and target analysis with data- dependent (DDA) and data-independent acquisition (DIA) methods exploring the performances for the determination of multitargeted compounds have been proposed. The tentative compounds have been firstly filtered using a suspect list of 2784 compounds retrieved by different databases available in the literature. The validated methods were then applied to analyse surface water samples coming from different sites in Europe. The presence of natural toxins produced by both plants, fungi, and cyanobacteria is a reality in different water environments showing their presence at low levels also in unexpected zones with not favorable conditions for their production. Almost 80% of the natural toxins encountered were phytotoxins, while a small number of cyanotoxins and mycotoxins have been tentatively identified. The chemical diversity is generally driven by the botanical diversity and the anthropization of the area. Besides, the seasonality and the precipitations are crucial parameters to understand the presence of phytotoxins respect to the cyanotoxins which have been encountered also in unexpected seasons. However, the quantification was not possible for all natural toxins, since only 32 standards were available in our study. In conclusion, the work presented in this thesis, allowed to fill some of the gaps in the analysis of natural toxins presenting two approaches to increase the knowledge about the identification of natural toxins in surface waters. In the future, should be crucial to update the latest determination approaches with the newest quantification strategies to finally implement the suspect screening approaches and reach both determination and quantification of suspect compounds when standards are not available.[cat] La presència de residus antropogènics al medi aquàtic, tant amb els canvis climàtics com a l’augment de les temperatures, crea condicions favorables per al desenvolupament d’organismes no desitjats capaços de produir toxines naturals que es combinen amb els altres contaminants antropogènics coneguts. Les toxines naturals inclouen multitud de metabòlits secundaris tòxics produïts per animals, bacteris, algues fongs i plantes que no solen estar concebuts com a contaminants ambientals que preocupin la qualitat de l’aigua. Entre elles, les toxines naturals produïdes per algues (cianotoxines), fongs (micotoxines) i plantes (fitotoxines) són les més freqüents en entorns d’aigües superficials. Alguns d’ells expliquen diversos efectes tòxics contra el cos humà. Els efectes cancerígens, dermotòxics i neurotòxics s’associen generalment a aquests compostos. La preocupació pels efectes dels cianobacteris sobre la salut humana ha crescut en molts països en els darrers anys per diversos motius. Aquests inclouen casos d’intoxicacions atribuïdes a cianobacteris tòxics i la consciència de la contaminació de les fonts d’aigua (especialment els llacs) que es tradueix en un augment del creixement de la cianobacteria. Malgrat això, la seva presència a les aigües superficials no estava regulada ni limitada de manera uniforme, i només la microcistina-LR altament tòxica estava limitada a 1 µg / L per la Directiva sobre aigua potable (Text consolidat: Directiva 98/83 / CE del Consell, de 3 de novembre de 1998 sobre la qualitat de l’aigua destinada al consum humà) de l’Organització Mundial de la Salut. A més, els estudis sobre la seva aparició, persistència química, flotabilitat i predicció de l'aparició de les flors d'algues al medi ambient encara són escassos. L'avaluació del risc ambiental és difícil i el grau de toxicitat en els ecosistemes d'aigües superficials encara està poc estudiat. La identificació i quantificació són difícils a causa de la manca d’estàndards certificats disponibles i el seu destí a l’entorn es pot descriure mitjançant coeficients de distribució com el repartiment octanol-aigua (Kow). Altres dades capaces de definir altres paràmetres de distribució i partició s’obtenen generalment mitjançant eines de predicció in silico. A més, aquests compostos es troben barrejats amb altres grups de productes químics a baixes concentracions. La majoria dels mètodes publicats per a la seva determinació estan dissenyats específicament per identificar un sol compost o un grup de toxines amb característiques similars, cosa que fa que el procés d’identificació de diferents compostos sigui estressant i requereixi temps mitjançant enfocaments específics. Atès que s’ha determinat la perillositat de les toxines naturals a l’aigua superficial, es van produir i publicar dades valuoses per avaluar-ne la presència i la concentració. S'han informat de diverses tècniques analítiques per a la seva anàlisi quantitativa, entre les quals s'utilitzen MALDI-TOF/MS, LC-ESI/HRMS, LC-ESI-QqQ. No obstant això, a causa dels milers de compostos i de la seva extrema heterogeneïtat, el “suspect screening” ha tingut un paper central com a propòsit de idenficació de compostos desconeguts. Al llarg dels anys, el "suspect screening” va implicar l’ús de metòdiques “in-silico” per a la identificació provisional de toxines naturals, convertint-se en un dels mètodes preferits per a l’anàlisi sospitós de compostos desconeguts en aigües superficials. És de primera importància desenvolupar i optimitzar nous mètodes capaços d’identificar toxines naturals en diversos rangs de polaritats, des de les més hidròfobes fins a les més afines a l’aigua. Les proves es centren generalment en cianotoxines sense implementacions quant a toxines vegetals i les micotoxines que estan molt poc estudiades en aigües superficials. En aquest marc, aquesta tesi té com a objectiu augmentar el coneixement sobre les toxines naturals de les aigües superficials. La primera part de l’estudi es va centrar en els recents avenços en la detecció de toxines naturals que recuperen multitud d’enfocaments analítics per a la seva determinació en aigua superficial i potable. Finalment, s’han introduït dos enfocaments de detecció de sospitosos que utilitzen anàlisis de sospitosos i objectius amb mètodes d’adquisició dependents de dades (DDA) i d’adquisició independent de dades (DIA) que exploren el rendiment per a la determinació de compostos multidirectius. Els compostos provisionals s'han filtrat en primer lloc mitjançant una llista sospitosa de 2784 compostos recuperats per diferents bases de dades disponibles a la literatura. A continuació, es van aplicar els mètodes validats per analitzar mostres d’aigua superficial procedents de diferents llocs d’Europa. La presència de toxines naturals produïdes per les plantes, els fongs i els cianobacteris és una realitat en diferents ambients aquàtics que mostren la seva presència a nivells baixos també en zones inesperades amb condicions no favorables per a la seva producció. Gairebé el 80% de les toxines naturals trobades eren fitotoxines, mentre que només s’han identificat provisionalment poques cianotoxines i micotoxines. La diversitat química es basa generalment en la diversitat botànica i l'antropització de la zona. A més, l'estacionalitat i les precipitacions són paràmetres crucials per entendre la presència de fitotoxines respecte a les cianotoxines que s'han trobat també en estacions inesperades. No obstant això, la quantificació no va ser possible per a totes les toxines naturals, ja que només hi havia 32 estàndards disponibles al nostre estudi. En conclusió, el treball presentat en aquesta tesi va permetre omplir alguns dels buits de l’anàlisi de toxines naturals presentant dos enfocaments per augmentar el coneixement sobre la identificació de toxines naturals en aigües superficials. En el futur, hauria de ser crucial actualitzar el darrer enfocament de determinació amb mètodes de quantificació més nous implementant les metòdiques analítiques fent possible la caracterització i la quantificació amb el mateix mètode

Traditional Biocidal Replacement Viability of Microcrystalline Silver Chloride

The antimicrobial effects of silver ions and silver chloride nanoparticles have been well established while the efficacy of microcrystalline silver chloride has been less studied. Certex-AM, a microcrystalline silver chloride product produced by Cerion, Rochester, NY, was tested for its antimicrobial properties as a possible replacement for traditional biocidal techniques used in water cooling towers. The minimum inhibitory concentration (MIC) of the compound was determined using a microtiter broth assay. The compound was found to have inhibitory effects on bacterial growth for all tested organisms at concentrations greater than 9 ppm. Additional testing simulating a water cooling system showed the effectiveness of reducing an established wild population at concentrations of 10 ppm of the microcrystalline silver chloride. Certex-AM was found to be a promising replacement for traditional biocides as well as for other applications. Introduction of effective antimicrobial compounds such as this could reduce the pathogenic risk to humans associated with water cooling towers

Brecha digital en el sector educativo salvadoreño: retos y estrategias

El siguiente artículo presenta tres escenarios de análisis para auscultar la brecha digital en El Salvador: el teológico, el educativo y el educativo, tecnológico, precedidos por una reflexión sobre las TIC y la brecha digital; inicialmente, para concluir se proponen un conjunto de estrategias institucionales desarrolladas de índole tecnológico a modo de contrapeso de los grandes problemas de la brecha existent

Preferential Sampling of Elastic Chains in Turbulent Flows

A string of tracers, interacting elastically, in a turbulent flow is shown to have a dramatically different behaviour when compared to the non-interacting case. In particular, such an elastic chain shows strong preferential sampling of the turbulent flow unlike the usual tracer limit: an elastic chain is trapped in the vortical regions and not the straining ones. The degree of preferential sampling and its dependence on the elasticity of the chain is quantified via the Okubo-Weiss parameter. The effect of modifying the deformability of the chain, via the number of links that form it, is also examined.Comment: 6 pages, 4 figure

EU-Japan: A Partnership of Renewed Importance. EU Centre Background, Brief 20th July 2018

This background brief explores the prospect of a stronger European Union’s (EU) economic and political leverage in the Asia Pacific region through the analysis of EU-Japan relations. The paper delves into the main drivers and implications of the two bilateral treaties recently concluded between the EU and Japan, the Economic Partnership Agreement (EPA) and Strategic Partnership Agreement (SPA). The political environment that surrounded the agreements is deeply marked by crisis and uncertainty. However, this paper develops the view that increased bilateral cooperation between the EU and Japan offers opportunities for the EU to boost its presence in Asia as well as increases both parties’ ability to face new challenges and adapt to a fast-changing international system

Influence of the sebaceous gland density on the stratum corneum lipidome

The skin surface lipids (SSL) result from the blending of sebaceous and epidermal lipids, which derive from the sebaceous gland (SG) secretion and the permeability barrier of the stratum corneum (SC), respectively. In humans, the composition of the SSL is distinctive of the anatomical distribution of the SG. Thus, the abundance of sebum biomarkers is consistent with the density of the SG. Limited evidence on the influence that the SG exerts on the SC lipidome is available. We explored the differential amounts of sebaceous and epidermal lipids in areas at different SG density with lipidomics approaches. SC was sampled with adhesive patches from forearm, chest, and forehead of 10 healthy adults (8F, 2M) after mechanical removal of sebum with absorbing paper. Lipid extracts of SC were analysed by HPLC/(-)ESI-TOF-MS. In the untargeted approach, the naïve molecular features extraction algorithm was used to extract meaningful entities. Aligned and normalized data were evaluated by univariate and multivariate statistics. Quantitative analysis of free fatty acids (FFA) and cholesterol sulfate (CHS) was performed by targeted HPLC/(-)ESI-TOF-MS, whereas cholesterol and squalene were quantified by GC-MS. Untargeted approaches demonstrated that the relative abundance of numerous lipid species was distinctive of SC depending upon the different SG density. The discriminating species included FFA, CHS, and ceramides. Targeted analyses confirmed that sebaceous FFA and epidermal FFA were increased and decreased, respectively, in areas at high SG density. CHS and squalene, which are biomarkers of epidermal and sebaceous lipid matrices, respectively, were both significantly higher in areas at elevated SG density. Overall, results indicated that the SG secretion intervenes in shaping the lipid composition of the epidermal permeability barrier. © 2018, The Author(s)