Identification of a novel transporter for dicarboxylates and tricarboxylates in plant mitochondria. Bacterial expression, reconstitution, functional characterization, and tissue distribution.

A cDNA from Arabidopsis thaliana and four related cDNAs from Nicotiana tabacum that we have isolated encode hitherto unidentified members of the mitochondrial carrier family. These proteins have been overexpressed in bacteria and reconstituted into phospholipid vesicles. Their transport properties demonstrate that they are orthologs/isoforms of a novel mitochondrial carrier capable of transporting both dicarboxylates (such as malate, oxaloacetate, oxoglutarate, and maleate) and tricarboxylates (such as citrate, isocitrate, cis-aconitate, and trans-aconitate). The newly identified dicarboxylate-tricarboxylate carrier accepts only the single protonated form of citrate (H-citrate2-) and the unprotonated form of malate (malate2-) and catalyzes obligatory, electroneutral exchanges. Oxoglutarate, citrate, and malate are mutually competitive inhibitors, showing K(i) close to the respective K(m). The carrier is expressed in all plant tissues examined and is largely spread in the plant kingdom. Furthermore, nitrate supply to nitrogen-starved tobacco plants leads to an increase in its mRNA in roots and leaves. The dicarboxylate-tricarboxylate carrier may play a role in important plant metabolic functions requiring organic acid flux to or from the mitochondria, such as nitrogen assimilation, export of reducing equivalents from the mitochondria, and fatty acid elongation

Il rafforzamento della cooperazione giudiziaria in materia penale: da Eurojust al pubblico ministero europeo

2010 - 2011La necessità di una cooperazione giudiziaria in materia penale nell’Unione europea si è manifestata fin dal conseguimento dei primi successi raggiunti nell’ambito della costruzione comunitaria, e più che mai continua a manifestarsi oggi atteso il dilagare del crimine transnazionale. Proprio la realizzazione del mercato unico – e cioè, di uno spazio senza frontiere interne, nel quale assicurare i quattro principi fondamentali quali la libera circolazione delle merci, delle persone, dei servizi e dei capitali – ha, infatti, determinato una crescita esponenziale della criminalità ed una sua estensione non solo quantitativa ma soprattutto spaziale di essa. Se, in particolare, la cd. globalizzazione dei rapporti socioeconomici, la liberalizzazione delle regole relative agli spostamenti delle persone e, dei beni e, da ultimo, lo sviluppo delle relazioni umane, (anche grazie a strumenti tecnologici) ed informatici, hanno consentito un sempre più celere progresso sociale, al tempo stesso, hanno agevolato gli autori dei più svariati crimini, consentendo loro di estendere la propria attività delinquenziale oltre confine, in tal modo coinvolgendo interessi sia individuali sia collettivi riferibili a più ordinamenti nazionali. In tale contesto, un ruolo determinante ha assunto la differenza tra le legislazioni penali degli Stati membri, la quale, nel combinarsi con le singole libertà di circolazione, ha determinato una sorta di forum shopping criminoso, consentendo ai “soggetti criminali” di scegliere la giurisdizione e la legge penale più vantaggiose così sottraendo alla giustizia se stessi ed i proventi illeciti conseguiti.In questa nuova e complessa realtà sociale e criminologica, sono diventati obsoleti i principi della territorialità della legge e della giurisdizione, così come si sono dimostrati del tutto inadeguati ed inidonei gli strumenti tradizionalmente adottati nel campo della cooperazione giudiziaria internazionale (caratterizzata dal principio della richiesta, in base al quale uno Stato sovrano presenta una richiesta ad un altro Stato sovrano, che decide se darvi o meno seguito), sia per la loro lentezza, sia anche per la loro complessità rispetto allo sviluppo anche “criminale” dell’Unione europea. Questo percorso ha fatto si che progressivamente le autorità giudiziarie cominciassero ad avere un dialogo tra loro, e nel tempo, questa prospettiva si è modificata attraverso diversi fattori: l’efficacia riflessa delle norme comunitarie sugli ordinamenti nazionali; la individuazione di beni giuridici sovranazionali ( si pensi al tema dell’ambiente); le esigenze di cooperazione giudiziaria. Questi sono stati i tre grandi motori che hanno spinto verso la costruzione di uno spazio di libertà sicurezza e giustizia indicato da Amsterdam tra gli obiettivi fondanti dell’Unione europea. Il ventisette Paesi dell’UE hanno rappresentato lo spazio nel quale si è cercato, con una costruzione spesso faticosa, di creare una prospettiva di sicurezza, libertà e giustizia. In questo percorso di “metamorfosi dei diritti nazionali” si è inserito Eurojust, un organismo che ha facilitato la cooperazione giudiziaria e le indagini a carattere transnazionale. [a cura dell'autore]X n.s

Human Motion Trajectory Prediction: A Survey

With growing numbers of intelligent autonomous systems in human environments, the ability of such systems to perceive, understand and anticipate human behavior becomes increasingly important. Specifically, predicting future positions of dynamic agents and planning considering such predictions are key tasks for self-driving vehicles, service robots and advanced surveillance systems. This paper provides a survey of human motion trajectory prediction. We review, analyze and structure a large selection of work from different communities and propose a taxonomy that categorizes existing methods based on the motion modeling approach and level of contextual information used. We provide an overview of the existing datasets and performance metrics. We discuss limitations of the state of the art and outline directions for further research.Comment: Submitted to the International Journal of Robotics Research (IJRR), 37 page

Laser-induced softening analysis of a hardened aluminum alloy by physical simulation

AbstractThe study focuses on the analysis of the softening effects of the work-hardened aluminum alloy sheets EN AW 5754 H32 1.5 mm thick, through the physical simulation of thermal cycles induced in the material by laser heat treatments (LHTs). A numerical-experimental approach was implemented to define the laser thermal cycles and to subsequently reproduce them on the GleebleTM 3180 physical simulator. The obtained softening was measured by microhardness and metallographic analysis tests. For the definition of laser thermal cycles, preliminary tests with a 2.5 kW CO2 laser source have been realized, and a three-dimensional transient finite element thermal models were developed and calibrated with the experimental results. The investigated laser heat treatment parameters explored thermal cycles with different shape, interaction time, and peak temperature. Physical simulation tests were performed using laser thermal cycles that showed the maximum softening of the aluminum alloy. A three-dimensional transient finite element thermoelectric model was developed to design the shape of the Gleeble specimens, which satisfy the heating and cooling rate required by laser thermal cycles. Results obtained show that it is possible to physically simulate the investigated laser thermal cycles, reducing the cross section of the shaped part of the specimen. Softening effects depend on the thermal cycle shape. Greater softening is observed by increasing the interaction time and the peak temperature, but beyond a peak temperature threshold value, negligible effects are detected

The effect of network topologies on fully decentralized learning: a preliminary investigation

In a decentralized machine learning system, data is typically partitioned among multiple devices or nodes, each of which trains a local model using its own data. These local models are then shared and combined to create a global model that can make accurate predictions on new data. In this paper, we start exploring the role of the network topology connecting nodes on the performance of a Machine Learning model trained through direct collaboration between nodes. We investigate how different types of topologies impact the "spreading of knowledge", i.e., the ability of nodes to incorporate in their local model the knowledge derived by learning patterns in data available in other nodes across the networks. Specifically, we highlight the different roles in this process of more or less connected nodes (hubs and leaves), as well as that of macroscopic network properties (primarily, degree distribution and modularity). Among others, we show that, while it is known that even weak connectivity among network components is sufficient for information spread, it may not be sufficient for knowledge spread. More intuitively, we also find that hubs have a more significant role than leaves in spreading knowledge, although this manifests itself not only for heavy-tailed distributions but also when "hubs" have only moderately more connections than leaves. Finally, we show that tightly knit communities severely hinder knowledge spread

Identification in Saccharomyces cerevisiae of two isoforms of a novel mitochondrial transporter for 2-oxoadipate and 2-oxoglutarate.

The nuclear genome of Saccharomyces cerevisiae encodes 35 members of a family of membrane proteins. Known members transport substrates and products across the inner membranes of mitochondria. We have localized two hitherto unidentified family members, Odc1p and Odc2p, to the inner membranes of mitochondria. They are isoforms with 61% sequence identity, and we have shown in reconstituted liposomes that they transport the oxodicarboxylates 2-oxoadipate and 2-oxoglutarate by a strict counter exchange mechanism. Intraliposomal adipate and glutarate and to a lesser extent malate and citrate supported [14C]oxoglutarate uptake. The expression of Odc1p, the more abundant isoform, made in the presence of nonfermentable carbon sources, is repressed by glucose. The main physiological roles of Odc1p and Odc2p are probably to supply 2-oxoadipate and 2-oxoglutarate from the mitochondrial matrix to the cytosol where they are used in the biosynthesis of lysine and glutamate, respectively, and in lysine catabolism