Photoionization mass spectrometry of ω-phenylalkylamines: Role of radical cation-π interaction

Linear ω-phenylalkylamines of increasing alkyl chain length have been investigated employing synchrotron radiation in the photon energy range from 7 to 15 eV. These molecules have received considerable interest because they bear the skeleton of biologically relevant compounds including neurotransmitters and because of the possible interaction between the amino moiety and the phenyl ring. Recently, the contribution of this interaction has been assayed in both neutral and protonated species, pointing to a role of the polymethylene chain length. In this work, the ionization energy (IE) values of benzylamine (BA), 2-phenylethylamine (2-PEA), 3-phenylpropylamine (3-PPA), and 4-phenylbutylamine (4-PBA) were investigated in order to ascertain the impact of the different alkyl chain lengths and to verify an amino radical cation-π interaction. The IEs obtained experimentally, 8.54, 8.37, 8.29, and 8.31 eV for BA, 2-PEA, 3-PPA and 4-PBA, respectively, show a decreasing trend that is discussed employing calculations at the CBS-QB3 level. Moreover, the appearance energy values for major fragments produced by the photofragmentation process are reported

Rapeseed (canola) oil and other monounsaturated fatty acid-rich vegetable oils

Rapeseed (canola) and other monounsaturated fatty acid (MUFA)-rich oils are viewed as good candidates to replace, at least partially, the fish oil normally included in aquaculture feeds (aquafeeds). In fact, their utilization as a dietary lipid source for aquatic animals has some advantages over other readily available terrestrial alternative oils and fats; however, this is not without difficulties. MUFA are, indeed, easily digestible and a good source of available energy, and their deposition into fish flesh is considered to be less detrimental than other fatty acid classes, from a human nutritional viewpoint. This chapter attempts to review the principal information available regarding the utilization of MUFA-rich vegetable oil (VO) in aquaculture feed. Initially the chapter focuses on the rapeseed oil eRa) industry, agronomy, quality improvement, processing, and uses, and the main chemical and physical characteristics of rapeseed oil and other MUFA-rich va such as olive oil, peanut oil, and rice bran oil, amongst others. Following this, the potential advantages and challenges of using these alternative oils in the aquaculture feed industry are presented and discussed.<br /

Leptin and lipid metabolism in fish

The aim of this chapter is to highlight potential links between leptin and the lipid metabolism in fish, within the context of current research interests of the fish nutrition amd aquaculture sector. In fact, it is envisaged that the whole aquacuture and fish biology sector will significantly benefit from an increased knowledge of such a powerful hormone, and it is believed&nbsp;this will contribute in transforming current aquaculture industry into an environmental and economical means of producing nourishing fish and seafood for the growing global population. The context is framed by a brief introduction on the current challenges in aquaculture and fish nutrition, and susequently the chapter focuses on the potential roles of leptin on voluntary food intake and lipid digestion and absorption in fish. Following this, the possible roles of leptin on lipid deposition and utilisation and the fatty acid metabolism in fish are presented and discussed. Eventually the possible interrelationships between dietary lipids and leptin are analysed underlining how knowledge gained from human nutrition could be extremely useful to tentatively address current constraints and obstacles found in the aquaculture nutrition sector. The present analysis suggests that we are likely only able to see the tip of the iceberg, and great and significant breakthrough discoveries will be likely by fathoming such fascinating area of research

Fish oil replacement in starter, grow-out, and finishing feeds for farmed aquatic animals

As aquaculture production continues to grow, there will be an increased use of lipid resources (oils and fats) alternative to fish oil for feed production. The potential for the use of these alternatives varies depending on the feeds in which they are included according to the production phase of the animals to which they are being fed. In starter feeds, where rapid growth, high survival, and normal development are critical priorities, there will remain a need for the use of lipid resources high in omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA). Fish in this starter phase have a critical requirement for the n-3 LC-PUFA docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and fish oils remain the only cost-effective source of these nutrients in the volumes required. However, the greatest demand for lipids is in those diets for the grow-out phase. Most studies on alternative lipid use with animals in this part of the production phase show positive outcomes, in that there are few studies where all the added fish oil cannot be replaced. There are some species, however, where potential replacement levels are suggested to be more conservative, and a general substitution level in this production phase of 75% has been suggested. One of the key effects noted across the grow-out phase is that all alternatives affect the flesh fatty acid characteristics by reducing the level of n-3 LC-PUFA. This issue has provoked the concept of finisher diets, whereby a high n-3 LC-PUFA content diet is fed in order to restore the desired meat fatty acid profiles. Studies examining this concept have found that the tissue triacylglycerol fatty acids were greatly modified and responded in a simple dilution process to the added oil fatty acid composition, whereas the fatty acids of tissue phospholipids were less influenced by dietary fatty acid makeup.<br /

Time-resolved optical studies, heat dissipation and melting of Ag and Au nanoparticle systems and arrays

Transient absorption spectroscopy has been extensively used in recent years to examine the temporal response of isolated nanoparticles (NPs) to the absorption of light [1]. These studies are largely based on the use of the surface plasmon resonance (SPR) to monitor characteristics of the NP such as electronic and lattice temperature, shape and morphology as a function of time. In the case of extended Au/Ag NP structures the plasmon resonance is strongly distorted due to the inter-particle coupling effects. For example, we have observed this effect in Rhodamine dye functionalized Au nanoparticles which undergo self-assembly to form nanostructures due to the interactions between the dye molecules attached to the surfaces of the nanoparticles. Indeed the SPR splits into two with one resonance remaining in the vicinity of that of the isolated AuNPs and is generally called the transverse SPR while a second resonance due to an extended excitation spanning across multiple particles appears to the lower energies. The precise spectral energy and shape of the extended plasmon resonance depends on the inter-particle distance, the particle disposition and the number of particles involved. When the plasmon band or interband spectral region of the NP is excited by an intense pulse the photon energy absorbed by the electrons is transferred to the lattice of the NP as heat through electron-phonon coupling. Depending on the intensity of the light pulse and thus the initial electron temperature a number of outcomes are possible. The first aim of this work is to use low intensity pump pulses to study the wavelength dependence of the sub 10 ps dynamics which reflects the electron-photon scattering within the nanoparticle structure. On the other hand, the interaction of more intense light with the NPs can modify the morphology of NP systems, for example by reshaping gold nanorods into nanospheres or, in general, mediate the synthesis of metallic nanostructures. At medium intensities the initial temperature is sufficient to induce melting of the NPs which can lead to morphological changes of the NP structure. Higher intensities can cause other effects such as photofragmentation of the NPs, release of stabiliser molecules from the surface of the NPs or even Coulomb explosion due to multiple ionisation events. The second aim of this work is to concentrate on the effects of medium intensity laser excitation of a self-assembled Au/Ag NP systems. The NP system is excited by a femtosecond laser pulse of different wavelengths allowing selective deposition of energy and the subsequent heat dissipation through phonon-phonon coupling and morphological changes are monitored in time by recording transient absorption spectra in the visible range. This wavelength range makes it possible to follow the phonon-phonon coupling effects on the recovery of the bleaching of both the transverse and extended plasmon resonances of the NP system. As the intensity of the pump pulse is increased it can be seen that the NPs are no longer able to dissipate all of the heat before arrival of subsequent laser pulses thus leading to melting of the NP structure and strong changes in the plasmon response of the system. The overall aim of this study is to fully understand the delocalized electron-phonon coupling in the extended plasmon region of the NP structures and to use this knowledge to control the melting in nanostructures. The methods developed can be useful for plasmon mediated nano-engineerin

TRANS(FORM)STATION. Le nuove dimensioni della stazione verso l’alta velocità

Attraverso permanenze ed evoluzioni della stazione ferroviaria, insieme alle trasformazioni della città e le mutazioni delle sue componenti (nodi ed infrastrutture), seguiremo i processi di modificazione spaziale dalla stazione moderna alla stazione dell’alta velocità e le metamorfosi della città in un sistema di reti urbane. La città interpretata come rete, quindi, o meglio come sistema complesso di stratificazione di flussi, materiali ed immateriali, si rigenera al modificare della dimensione dei nodi e delle infrastrutture acquistando nuovi definizioni e significati. Il nodo (infrastrutturale), infatti, seguirà sviluppi multipli di tipo funzionale, spaziale ed urbano, diventando un “iper-polo” complesso e strategico della rete della mobilità, connettore urbano e scambiatore di flussi di una città. Tutto questo prenderà il nome di hub! L’hub sarà inteso, quindi, come nuova morfologia architettonica ed urbana delle grandi infrastrutture di trasporto che raccoglie i concetti di trasversalità, flessibilità, mutifunzionalità (mixité) ed interconnessione come principi fondamentali per il funzionamento e la “crescita” delle reti urbane verso una visione policentrica della città. Basta pensare alla grande sfida del Gran(d) Paris, un progetto pensato come una scommessa verso un Système de Grand Métropole, mettendo a confronto metodologie e strategie dei vari gruppi partecipanti (Rogers, MVRDV, Studio 08, Lin, Nouvel, Portzamparc, Grumbach), prevede un programma di sviluppo sostenibile ed una prefigurazione tesa a trasformare l'agglomerato della regione parigina in una metropoli policentrica e rafforzare lo sviluppo della rete della mobilità. Nello specifico l’hub oggetto di studio, quale cerniera ed articolazione sensibile tra rete e città, sarà la Stazione dell’Alta Velocità. Come per altre infrastrutture urbane (aeroporto, porto, fermate bus, stazione metropolitana o tranviaria) la Stazione AV verrà considerata come un “commutatore”, ovvero un connettore urbano di transizione tra la scala globale, metropolitana e locale, in grado di regolare i flussi in movimento della città e, al tempo stesso, stabilire con essa livelli differenziati d’integrazione. La stazione AV, così, assumerà i caratteri per diventare un progetto g-locale multidimensionale (3D-imensioni: Macro_Meso_Micro) di globalizzazione dei flussi e di localizzazione dei luoghi attraverso un processo di sintesi tra la logica del territorio, del “luogo”, e la logica delle reti e delle funzioni, e verrà a configurarsi come un sistema dinamico, “ d’interferenza tra linee di forza del campo esterno e specificità di flussi che lo interessano, secondo un procedimento di sintesi che si traduce in forme architettoniche specifiche, non eludibili entro un generico modello di controllo” (S. Sassen, "Globalizzati e scontenti. Il destino delle minoranze nel nuovo ordine mondiale", Il Saggiatore, Milano 2002). La stazione AV, infatti, supererà il concetto di “oggetto” architettonico inserito/da inserire in tessuti urbani consolidati o periferici, per diventare progetto in evoluzione in termini di estensione spaziale, ruolo, funzionamento e proprietà che generano degli effetti sul tessuto urbano. Sara importante, quindi, seguire l’evoluzione e la mutazione della Stazione AV come “infrastruttura” urbana e spaziale tridimensionale, non solo da un punto di vista tipologico-formale (storico), ma soprattutto in rapporto ai processi di trasformazione urbana, come già riscontrato nei numerosi contributi che riguardano le “Megastrutture” di Yona Friedman, Cedric Price, Fumihiko Maki, Kenzo Tange, Archigram e Paul Maymont, piuttosto che le nuove “Figure della mobilità” di Bernardo Secchi, o il sistema “rete-rizoma” di Gilles Deleuze e Felix Guattari. L’analisi critica e sistemica di alcuni progetti paradigmatici tra fallimenti, utopie, anticipazioni, proiezioni e visioni sarà fondamentale per comprendere i “segni” del cambiamento della stazione AV cercando di individuarne caratteri e proprietà. Il proporre una sintesi delle trasformazioni funzionali dei nodi d’interscambio infrastrutturale, in Italia, in Europa e nel mondo, rappresenta la volontà di coglierne l’evoluzione legata non solo alle innovazioni tecnologiche-costruttive e all’importanza dei flussi che l’attraversano, ma anche alla mutazione del rapporto tra rete infrastrutturale e città. Si tratta di comprendere il fenomeno e il processo di trasformazione delle reti stratificate di una città nelle sue articolazioni spaziali e relazionali, oltre che funzionali, per fornire gli strumenti di lettura per l’identificazione della staziove AV con l’hub e come “progetto in rete”. La ricerca mira all’individuazione degli elementi-componenti in una stazione AV, definendone l’interconnessione e l’inter-dipendenza con la propria rete, il sistema delle reti ad essa collegato ed i processi di rigenerazione e trasformazione della città attraverso l’individuazione di valori parametrici fondamentali e determinati in funzione della scala (dimensione scalare), dei livelli di scambio con il sistema (modi di scambio) e del tempo. Queste matrici (_3M), estrapolate dallo studio critico del complesso sistema di trasporto integrato che coinvolge fattori differenti in funzione principalmente dei legami tra le relazioni interne (spazio) ed esterne (contesto) della stazione AV, permetteranno di stabilire i caratteri prevalenti e complementari (_3C) della stazione stessa, quali multiscalarità, multimodalità e multiprogramma. Queste proprietà, infatti, racchiudono una molteplicità di valori che regolano i gradi d’interazione e le relazioni tra stazione AV e città a scale differenti (_3D-imensioni: Macro_Meso_Micro). La dimensione scalare della stazione AV, così, porterà con sé una capacità trasformazionale in grado d’innescare nuove dinamiche e sviluppi urbani. La riconnessione integrale tra i modi di trasporto moltiplicata per la contemporaneità delle funzioni e dei programmi (intesi come sequenza di azioni differenziate nel tempo) e per le differenti velocità dello spostamento (multitemporalità), genera un’ibridazione ed una contaminazione funzionale e sociale che configura la stazione AV come piattaforma complessa di collegamento performante e flessibile nello spazio-tempo. Il codex di classificazione determinato dall’approfondimento di questi temi porterà all’individuazione, non di un unico modello tipologico seppur flessibile, ma di 3 PROTO-TYPE, ovvero tre istanze prototipiche, che seguiranno sviluppi morfo-spaziali differenti e/o complementari: ponte abitato, piastra lineare, millefeuille (millestrati). Il “ponte abitato”, come spazio dell’attraversamento e boulevard urbano sospeso, è identificato come riconnessione e ricucitura urbana in grado di raccordare l’atopia dei luoghi urbani, ricostruire un paesaggio interrotto ed i frammenti ambientali presenti nella città attraverso il recupero dello spazio urbano che diventa abitato dalle persone in tempi differenti ed il rafforzamento della stazione come passage e portale della citta (Nodo AV di Roma Tiburtina, Stazione Porta Napoli ad Afragola, Ourense AVE Station a Galizia, Wuhan Station in Cina). La “piastra lineare”, intesa come polo di scambio dallo sviluppo prevalentemente orizzontale e lineare, è concepita come un continuum spaziale di collegamento “integrale” per la città e “collettore” di flussi dei percorsi urbani esistenti. La stazione diventa, così, percorso urbano, aperto ai flussi pedonali, e permeabile longitudinalmente e trasversalmente, attraverso un sistema di percorsi articolato su più livelli della città, trasformandosi in strada, in luogo di nuova urbanità ed evento collettivo (Nodo AV di Torino Porta Susa, New Guangzhou Station in Cina, New Delhi Railway Station, Kyoto Station Building). Il millefeuille (o millestrati), assimilato ad uno spazio stratificato in piani di attività e campi di movimento dallo sviluppo verticale, è generato da una stratificazione ed un intreccio di flussi in un sistema dinamico multilivelli e dai percorsi multipli. In questo spazio della “congestione” dominano Interferenze, concatenazioni di ritmi, velocità differenziate e sovrapposte dove coesistono movimento e variazione. Lo spazio risulta una “superagglomeration”, come in un condensatore urbano, dove integrazione ed interconnessione regolano il circuito interno (Stazione AV Firenze Belfiore, Kowloon Station ad Hong Kong, Gare Montparnasse a Parigi, Transbay Transit Center a San Francisco, Beijing South Railway Station a Pechino). Queste tre categorie definiscono, così, le possibili trasformazioni e combinazioni della stazione AV in un vero e proprio hub e le sue nuove dimensioni in termini spaziali e relazionali con la città alle diverse scale d’interconnessione urbana attraverso confluenze segniche e nuove progettualità ancora in corso di sperimentazione. L’obiettivo finale sarà, quindi, riuscire a dimostrare come la stazione AV, quale hub, è diventata un progetto g-locale che stabilisce un rapporto d’interconnessione e d’interdipendenza con la rete dalla quale non può prescindere per il suo funzionamento e l’accrescimento della rete stessa. I proto-tipi individuati segneranno questo fondamentale “passaggio” verso nuove sfide ma anche nuove frontiere della stazione AV

The acoustics of public square/places: a comparison between results from a computer simulation program and measurements in situ

http://www.odeon.dk/pdf/InterNoise2004.pd

Effect of dietary saturated and monounsaturated fatty acids in juvenile barramundi Lates calcarifer

Barramundi (Lates calcarifer), a catadromous teleost of commercial interest, perform well when fed a wide range of dietary oils. However, the range of alternative oils now being explored is typically rich in saturated and monounsaturated fatty acids (SFA and MUFA). In this study, the response of juvenile barramundi (47.0 g per fish initial weight) fed isolipidic and isoenergetic diets with 82 g kg-1 added oil was tested. The experimental test diets had a 2 : 1 or 1 : 2 ratio of SFA to MUFA (SFA-D and MUFA-D, respectively) compared to a control diet (CTRL-D) fed for 8 weeks. The diets containing mostly olive oil (dietary MUFA-D) and mostly refined palm oil (dietary SFA-D) did not impact the growth performance or feed utilization parameters of the barramundi. The in vivo beta-oxidation activity was consistent with the dietary fatty acid composition, with the most dominant FA being heavily beta-oxidized. Together, the in vivo whole-body mass balance of fatty acids showed that n-3 long-chain polyunsaturated fatty acids (LC-PUFA) were most efficiently utilized in the SFA-D- and MUFA-D-fed fish. This study provides evidence that additional dietary MUFA and SFA are suitable lipid classes for juvenile barramundi and they are both equally efficient at sparing LC-PUFA from an oxidative fate.

Alternative Lipid Sources in Aquafeeds

The global aquaculture industry is one of the fastest growing food production sectors with farmed seafood currently accounting for about 50% of all fish consumed in the world. It is estimated that aquaculture produces about 65 million tonnes of seafood valued at more than US$78 billion annually. Aquaculture is anticipated to play an increasingly important role in meeting the seafood demand of a growing human population. The rapid increase in aquaculture production worldwide has been fueled by the use of industrially manufactured aquafeeds. Conventionally, marine fish meal and fish oil are used as the major feed ingredients in the formulation of commercial aquafeeds to supply dietary protein and lipid, respectively. It is estimated that aquafeeds currently consume about 90% of the global supply of fish oil and many have predicted that the demand for fish oil from the aquaculture industry will imminently out strip supply. Marine fish oil production has not increased beyond 1.5 million tonnes for the past quarter of a century and in order to further expand, the global aquaculture industry cannot continue to rely solely on this source of lipid. The high demand, impending short supply and often times high prices makes dietary fish oil a bottle-neck in the farming of aquatic animals, and there is currently great urgency within the global aquafeed industry in finding suitable alternatives to replace marine fish oils. This article will give an overview of the various alternative lipid sources, grouped according to their main chemical characteristics. Their unique potential advantages and challenges for use in aquafeeds will be highlighted. The physiological effects of various lipid sources and their components on growth, lipid metabolism, health and post-harvest qualities of the farmed fish are briefly discussed

Thoughts for the Future of Aquaculture Nutrition: Realigning Perspectives to Reflect Contemporary Issues Related to Judicious Use of Marine Resources in Aquafeeds

In recent decades, aquaculture nutrition research has made major strides in identifying alternatives to the use of traditional marine‐origin resources. Feed manufacturers worldwide have used this information to replace increasing amounts of fish meal and fish oil in aquafeeds. However, reliance on marine resources remains an ongoing constraint, and the progress yielded by continued unidimensional research into alternative raw materials is becoming increasingly marginal. Feed formulation is not an exercise in identifying "substitutes" or "alternatives" but rather is a process of identifying different combinations of "complementary" raw materials—including fish meal, fish oil, and others—that collectively meet established nutrient requirements and other criteria for the aquafeed in question. Nutrient‐based formulation is the day‐to‐day reality of formulating industrially compounded aquafeeds, but this approach is less formally and explicitly addressed in aquaculture research and training programs. Here, we (re)introduce these topics and explore the reasons that marine‐origin ingredients have long been considered the "gold standards" of aquafeed formulation. We highlight a number of ways in which this approach is flawed and constrains innovation before delving into the need to assess raw materials based on their influence on aquafeed manufacturing techniques. We conclude with a brief commentary regarding the future funding and research landscape. Incremental progress may continue through the accumulation of small insights, but a more holistic research strategy—aligned with industry needs and focused on nutrient composition and ingredient complementarity—is what will spur future advancement in aquaculture nutrition.This article also appears in: World Fisheries Da