Bioaccumulation modelling and sensitivity analysis for discovering key players in contaminated food webs: the case study of PCBs in the Adriatic Sea

Modelling bioaccumulation processes at the food web level is the main step to analyse the effects of pollutants at the global ecosystem level. A crucial question is understanding which species play a key role in the trophic transfer of contaminants to disclose the contribution of feeding linkages and the importance of trophic dependencies in bioaccumulation dynamics. In this work we present a computational framework to model the bioaccumulation of organic chemicals in aquatic food webs, and to discover key species in polluted ecosystems. As a result, we reconstruct the first PCBs bioaccumulation model of the Adriatic food web, estimated after an extensive review of published concentration data. We define a novel index aimed to identify the key species in contaminated networks, Sensitivity Centrality, and based on sensitivity analysis. The index is computed from a dynamic ODE model parametrised from the estimated PCBs bioaccumulation model and compared with a set of established trophic indices of centrality. Results evidence the occurrence of PCBs biomagnification in the Adriatic food web, and highlight the dependence of bioaccumulation on trophic dynamics and external factors like fishing activity. We demonstrate the effectiveness of the introduced Sensitivity Centrality in identifying the set of species with the highest impact on the total contaminant flows and on the efficiency of contaminant transport within the food web

Las momias egipcias del Museo de La Plata

Uno de los temas que provocan más atracción por lo exótico, unción y respeto por su significado y hasta cierto temor por su tratamiento en museos y exposiciones, es el de las momias y cadáveres momificados, producto emergente de factores tan dispares como las elaboradas concepciones religiosas de las altas culturas de la antigüedad y las condiciones de extrema sequedad predominantes de los climas desérticos y semidesérticos. Pero siguiendo a Baines y Málek (1993), deducimos que ambos factores son dispares sólo en lo aparente.Sección: Tesoros del Museo.Fundación Museo La Plat

Las momias egipcias del Museo de La Plata

Uno de los temas que provocan más atracción por lo exótico, unción y respeto por su significado y hasta cierto temor por su tratamiento en museos y exposiciones, es el de las momias y cadáveres momificados, producto emergente de factores tan dispares como las elaboradas concepciones religiosas de las altas culturas de la antigüedad y las condiciones de extrema sequedad predominantes de los climas desérticos y semidesérticos. Pero siguiendo a Baines y Málek (1993), deducimos que ambos factores son dispares sólo en lo aparente.Sección: Tesoros del Museo.Fundación Museo La Plat

The life-cycle environmental performance of producing formate via electrochemical reduction of CO_{2} in ionic liquid

Carbon capture and utilisation provide a means to mitigate climate change caused by anthropogenic greenhouse gas emissions by delaying carbon emissions via temporary storage in goods. This article presents a comprehensive Life Cycle Assessment (LCA) study of a novel process that generates formate via electrochemical reduction of CO_{2} in ionic liquid. We performed a scenario analysis, covering uncertain parameters like the recycling rate of unreacted reagents and the market price of CO_{2}, and compared the environmental performance of the carbon utilisation system with that of the conventional process, which relies on fossil sources. Inventory data is obtained from a mix of literature sources and commercial LCA databases. Our analysis indicates that (i) the system needs to attain a 99.9% recycling rate to be competitive with the conventional process; (ii) a future negative market price of CO_{2} would substantially reduce the environmental impacts associated with formate; (iii) there are significant environmental trade-offs between the carbon utilisation system and the conventional process, with the former outperforming the latter in 6/8 out of the 14 impact categories investigated. It should be noted that our results are conservative because inventory data for the electrochemical reduction process is obtained from laboratory experiments

Can the use of captured CO2 lower the environmental impacts of formate production?

The majority of bulk chemicals (e.g. olefins and alcohols) are organic compounds that are almost exclusively produced from fossil feedstocks such as natural gas. Utilisation of carbon dioxide captured from anthropogenic sources, which are both inexpensive and abundantly available, represents an alternative pathway that is drawing increasing attention, mainly for its potential to decreasing emissions of greenhouse gases and resource depletion of chemicals production. Notably, carbon utilisation does not represent an approach to CO2 mitigation because it only delays its emissions rather than removing it over a long timescale; hence, the relevant question that we aim to address is: "Can captured CO2 be used as feedstock to reduce the environmental impacts of chemicals' production?". As a case study, this work focuses on the production of formate and presents a prospective comparative life cycle assessment (LCA) between the conventional fossil-based pathway and an innovative, CO2-based process, that involves the electro-catalytic reduction of CO2 using an ionic liquid as solvent. CO2 is assumed to originate from a natural gas-fired power plant and captured after combustion, through a conventional monoethanolamine absorption system. Ionic liquids are used to enanche the reduction of CO2 and its conversion to formate. The study adopts a cradle-to-gate perspective and analyses multiple impact categories including, but not limited to, global warming and resources depletion

20S proteasome mediated degradation of DHFR: implications in neurodegenerative disorders

The 20S proteasome is responsible for the degradation of protein substrates implicated in the onset and progression of neurodegenerative disorders, such as a-synuclein and tau protein. Here we show that the 20S proteasome isolated from bovine brain directly hydrolyzes, in vitro, the dihydrofolate reductase (DHFR), demonstrated to be involved in the pathogenesis of neurodegenerative diseases. Furthermore, the DHFR susceptibility to proteolysis is enhanced by oxidative conditions induced by peroxynitrite, mimicking the oxidative environment typical of these disorders. The results obtained suggest that the folate metabolism may be impaired by an increased degradation of DHFR, mediated by the 20S proteasome

Coupled system thermal Hydraulics/CFD models: General guidelines and applications to heavy liquid metals

This work aims to review the general guidelines to be adopted to perform coupled System Thermal Hydraulics (STH)/CFD calculations. The coupled analysis is often required when complex phenomena characterized by different characteristic time and length scales are investigated. Indeed, by STH/CFD coupling the main drawbacks of both stand-alone codes are overcome, reducing the computational cost and providing more realistic solutions. A review of several works available in literature and involving different coupling approaches, codes, time-advancing schemes and application fields is given. Besides STH/CFD coupling techniques, spatial domains and numerical schemes are analysed in detail. A brief description of applications to heavy liquid metal systems is also reported; lessons drawn in the frame of these and other works are then considered in order to develop a set of good practice guidelines for coupled STH/CFD applications

A successful local fluid-to-fluid similarity theory for heat transfer to supercritical pressure fluids: merits and limitations

A similarity theory, proposed with a limited success some years ago and subsequently refined in a more complex form in further efforts, has been applied in a recent published work to perform Direct Numerical Simulations (DNS) of heat transfer to turbulent flow, with four different fluids at supercritical pressure. The obtained results showed an exceptionally good behaviour of the theory in the addressed cases, suggesting that the initial proposal, though it had only limited success in the cases considered at that time, possibly caught some of the basic features to be preserved in scaling. The theory, based on dimensionless definitions that provided a reasonable degree of universality in the analysis of flow stability, found immediate difficulties to be applied with a comparable success to heat transfer problems. These difficulties mainly stemmed from the fact that, while it is relatively easy to scale fluid density, having a major role in stability analyses, it is definitely much harder to scale at a comparable level of accuracy the fluid thermo-physical properties, relevant in heat transfer. The very good results obtained in the recent work by DNS stimulated new reflections that shed light on the merits and limitations on the old theory. The present paper, starting from these recent results and discussing them in front of RANS calculations, is aimed to highlight the promising features of this theory, envisaging the missing steps that should be completed to make it more general, in order to give to its consequences a higher level of universality

Antiviral Property of the Fungal Metabolite 3-O-Methylfunicone in Bovine Herpesvirus 1 Infection

Bovine herpesvirus type-1 (BoHV-1) is a widespread pathogen that provokes infectious rhinotracheitis and polymicrobial infections in cattle, resulting in serious economic losses to the farm animal industry and trade restrictions. To date, non-toxic active drugs against BoHV-1 are not available. The exploitation of bioactive properties of microbial products is of great pharmaceutical interest. In fact, fungi are a promising source of novel drugs with a broad spectrum of activities and functions, including antiviral properties. Hence, the potential antiviral properties of 3-O-methylfunicone (OMF), a secondary metabolite produced by Talaromyces pinophilus, were evaluated on BoHV-1. In this study, during BoHV-1 infection in bovine cells (MDBK), the non-toxic concentration of 5 µM OMF considerably reduced signs of cell death and increased cell proliferation. Furthermore, OMF significantly decreased the virus titer as well as the cytopathic effect and strongly inhibited the expression of bICP0, the major regulatory protein in the BoHV-1 lytic cycle. These findings were accompanied by a considerable up-regulation in the expression of the aryl hydrocarbon receptor (AhR), a multifunctional transcription factor also linked to the host’s response to a herpesvirus infection. Overall, our results suggest that by involving AhR, OMF shows potential against a BoHV-1 infection

12-months prospective Pentraxin-3 and metabolomic evaluation in multiple sclerosis patients treated with glatiramer acetate

Background: Pentraxin-3 (PTX-3) is involved in acute immunological responses and it is a pro-inflammatory protein and a novel biomarker of inflammatory diseases. It is demonstrated that PTX-3 is higher in cerebrospinal fluid (CSF) of aggressive Multiple Sclerosis (MS). Metabolomics, the identification of small endogenous molecules, offers a molecular profile of MS. Glatiramer acetate (GA) is a widely used treatment for (MS) but its mechanism of action is not completely defined. The aim of our study is to analyze PTX-3 and metabolomic profile in MS patients compared to controls and to investigate the effect of GA on PXT-3 and metabolic molecules during treatment in responder and not responder MS patients. Methods: 28 unrelated MS patients and 27 age-and sex-matched controls were recruited. In serum, PTX-3 levels were measured by ELISA and Metabolomic panel was evaluated trough Nuclear Magnetic Resonance (NMR). According to clinical practice patients started GA treatment; PTX-3 and metabolomic identification were performed before and during treatment. Responders to treatment were identified if no evidence of instrumental, clinical relapses and disability progression (NEDA) occurred during follow up. Results: Serum PTX-3 levels were higher in MS patients compared to matched controls (7,85 ± 2,19 vs 6,20 ± 1,63 ng/ml) (p = 0,03); metabolomic evaluation shows higher levels of lactate and lower levels of valine, tyrosine and tryptophan in MS patients compared to controls. During therapy, PTX-3 levels have been reduced statistically significant (p = 0,001) at six months and one year of treatment. After one year, of the twenty patients that completed the study, 55% were considered fully responders to treatment; in these patients the mean reduction of PTX-3 at one year was higher respect to not responders (−3,82 ± 1,24 ng/ml vs −2,32 ± 1,03 ng/ml p = 0,02) and we observed a higher reduction of lactate, tyrosine and hypoxanthine and an increase of hydroxyproline and ADP as well as of three oxidative phosphorylation markers, citrulline, ornithine and tryptophan approaching the metabolic profile of healthy subjects. Discussion and conclusions: We demonstrated a metabolomic imbalance with mitochondrial dysfunction detected by higher levels of lactate and lower levels of tryptophan, tyrosine and valine in MS patients compared to healthy controls. The reduction of PTX-3 levels and the restoring of mitochondrial function, reducing oxidative stress by GA, allows to identify responder patients. Further and larger studies are needed to understand the predictive role of PTX-3 and metabolomic pattern in the identification of responder patients to GA