Kidney injury and cell therapy: Preclinical study

The aim of this study is to show histological and immunofluorescence analysis of renal parenchyma of agoutis affected by gentamicin-induced renal disease after the infusion of bone marrow mononuclear cells (BMMC) stained with Hoechst (R). Nine agouti's males were divided into three groups: Test group (TG): renal disease by gentamicin induced (n = 3), cell therapy group (CTG): renal disease by gentamicin induced and BMMC infusion (n = 3), and control group (CG): nonrenal disease and BMMC infusion (n = 3). TG and CTG were submitted to the protocol of renal disease induction using weekly application of gentamicin sulfate for 4 months. CG and CTG received a 1 X 108 BMMC stained with Hoechst and were euthanized for kidney examination 21 days after BMMC injection and samples were collected for histology and immunofluorescence analysis. Histological analysis demonstrated typical interstitial lesions in kidney similarly to human disease, as tubular necrosis, glomerular destruction, atrophy tubular, fibrotic areas, and collagen deposition. We conclude that histological analysis suggest a positive application of agouti's as a model for a gentamicin inducing of kidney disease, beyond the immunofluorescence analysis suggest a significant migration of BMMC to sites of renal injury in CTG. Microsc. Res. Tech., 2012. (c) 2011 Wiley Periodicals, Inc.

Hydrochemical variability at the Upper Paraguay Basin and Pantanal wetland

Compartmentalization is a prerequisite to understand large wetlands that receive water from several sources. However, it faces the heterogeneity in space and time, resulting from physical, chemical and biological processes that are specific to wetlands. The Pantanal is a vast seasonally flooded continental wetland located in the centre of South America. The chemical composition of the waters that supply the Pantanal (70 rivers) has been studied in order to establish a compartmentalization of the wetland based on soil-water interactions. A PCA-based EMMA (End-Members Mixing Analysis) procedure shows that the chemistry of the rivers can be viewed as a mixture of 3 end-members, influenced by lithology and land use, and delimiting large regions. Although the chemical composition of the end-members changed between dry and wet seasons, their spatial distribution was maintained. The results were extended to the floodplain by simple tributary mixing calculation according to the hydrographical network and to the areas of influence for each river when in overflow conditions. The resulting map highlights areas of high geochemical contrast on either side of the river Cuiaba in the north, and of the rivers Aquidauana and Abobral in the south. The PCA-based treatment on a sampling conducted in the Nhecolandia, a large sub region of the Pantanal, allowed the identification and ordering of the processes that control the geochemical variability of the surface waters. Despite an enormous variability in electrical conductivity and pH, all data collected were in agreement with an evaporation process of the Taquari River water, which supplies the region. Evaporation and associated saline precipitations (Mg-calcite, Mg-silicates K-silicates) explained more than 77% of the total variability in the chemistry of the regional surface water sampling.

Estudo do Padrão Respiratório e Movimento Toracoabdominal em Valvopatia Mitral

FUNDAMENTO: pacientes com valvopatia mitral podem evoluir com congestão pulmonar, que aumenta o trabalho dos músculos respiratórios; essa sobrecarga pode alterar o padrão respiratório com predomínio do deslocamento torácico ou presença de movimentos paradoxais. OBJETIVO: a) estudar o padrão respiratório e movimento toracoabdominal (MTA) em pacientes com doença mitral b) estudar o efeito do posicionamento nos parâmetros respiratórios c) correlacionar hipertensão pulmonar com presença de incoordenação do MTA. MÉTODOS: o padrão respiratório e o MTA de pacientes com doença mitral foram avaliados por pletismografia respiratória por indutância, nas posições dorsal e sentada, durante dois minutos de respiração tranquila. Analisou-se volume corrente (Vc) e tempos respiratórios e as variáveis do MTA. RESULTADOS: de 65 pacientes incluídos, 10 foram retirados, 29 participaram do grupo estenose mitral e 26 do grupo insuficiência mitral. O Vc, a ventilação pulmonar e o fluxo inspiratório médio aumentaram significantemente na posição sentada, sem diferenças entre os grupos. O MTA manteve-se coordenado entre os grupos e as posições; no entanto, cinco pacientes na posição dorsal apresentaram incoordenação (três no grupo estenose mitral; dois no grupo insuficiência mitral) com correlação significante com valores de pressão de artéria pulmonar (r = 0,992, p = 0,007). CONCLUSÃO: o padrão respiratório e o MTA não apresentam diferenças entre pacientes com estenose ou insuficiência mitral. A posição sentada aumenta o Vc sem alterar os tempos respiratórios. A presença de incoordenação toracoabdominal na posição dorsal esteve associação à hipertensão pulmonar.

Body weight, metabolism and clock genes

Biological rhythms are present in the lives of almost all organisms ranging from plants to more evolved creatures. These oscillations allow the anticipation of many physiological and behavioral mechanisms thus enabling coordination of rhythms in a timely manner, adaption to environmental changes and more efficient organization of the cellular processes responsible for survival of both the individual and the species. Many components of energy homeostasis exhibit circadian rhythms, which are regulated by central (suprachiasmatic nucleus) and peripheral (located in other tissues) circadian clocks. Adipocyte plays an important role in the regulation of energy homeostasis, the signaling of satiety and cellular differentiation and proliferation. Also, the adipocyte circadian clock is probably involved in the control of many of these functions. Thus, circadian clocks are implicated in the control of energy balance, feeding behavior and consequently in the regulation of body weight. In this regard, alterations in clock genes and rhythms can interfere with the complex mechanism of metabolic and hormonal anticipation, contributing to multifactorial diseases such as obesity and diabetes. The aim of this review was to define circadian clocks by describing their functioning and role in the whole body and in adipocyte metabolism, as well as their influence on body weight control and the development of obesity.

A coordenação da assistência no controle da tuberculose

Estudo epidemiológico descritivo que analisa a coordenação da assistência ao doente de Tuberculose em Serviços de Atenção Primária segundo 23 doentes, 16 profissionais e 17 gestores em Ribeirão Preto-SP, através de instrumento adaptado para avaliar a tuberculose. De acordo com os informantes, a coordenação da assistência ao doente em tratamento pela equipe do programa de controle da tuberculose foi considerada satisfatória. No entanto, quando há necessidade de encaminhar o doente a outros pontos de atenção, a coordenação da assistência apresenta pontos deficientes como descontinuidade do fluxo de comunicação e participação incipiente do doente no processo de atenção, havendo necessidade de aumentar a responsabilização pelo cuidado do doente e estimulá-lo como agente ativo do processo.

Estratégias de sinalização da qualidade da carne suína ao consumidor final

A suinocultura destaca-se na economia brasileira. Contudo, avaliando-se o consumo interno da carne suína in natura, observa-se uma estagnação em patamares baixos. O artigo tem como objetivo analisar as principais iniciativas adotadas pelo Sistema Agroindustrial (SAG) da carne suína no Brasil visando sinalizar qualidade aos consumidores. Devido à marcante assimetria de informações, ressalta-se a importância da organização da cadeia produtiva, melhor direcionando esforços para a expansão do mercado interno. Este trabalho sugere ações visando aprimorar a coordenação deste SAG com vistas à melhoria na qualidade da carne ao consumidor e à redução da informalidade.

Adipose tissue-derived mesenchymal stem cells increase skin allograft survival and inhibit Th-17 immune response

Adipose tissue-derived mesenchymal stem cells (ADSC) exhibit immunosuppressive capabilities both in vitro and in vivo. Their use for therapy in the transplant field is attractive as they could render the use of immunosuppressive drugs unnecessary. The aim of this study was to investigate the effect of ADSC therapy on prolonging skin allograft survival. Animals that were treated with a single injection of donor allogeneic ADSC one day after transplantation showed an increase in donor skin graft survival by approximately one week. This improvement was associated with preserved histological morphology, an expansion of CD4(+) regulatory T cells (Treg) in draining lymph nodes, as well as heightened IL-10 expression and down-regulated IL-17 expression. In vitro, ADSC inhibit naïve CD4(+) T cell proliferation and constrain Th-1 and Th-17 polarization. In summary, infusion of ADSC one day post-transplantation dramatically increases skin allograft survival by inhibiting the Th-17 pathogenic immune response and enhancing the protective Treg immune response. Finally, these data suggest that ADSC therapy will open new opportunities for promoting drug-free allograft survival in clinical transplantation.

Controllo dell'atto di prensione: coinvolgimento dell'area V6A nell'orientamento del polso

Prehension in an act of coordinated reaching and grasping. The reaching component is concerned with bringing the hand to object to be grasped (transport phase); the grasping component refers to the shaping of the hand according to the object features (grasping phase) (Jeannerod, 1981). Reaching and grasping involve different muscles, proximal and distal muscles respectively, and are controlled by different parietofrontal circuit (Jeannerod et al., 1995): a medial circuit, involving area of superior parietal lobule and dorsal premotor area 6 (PMd) (dorsomedial visual stream), is mainly concerned with reaching; a lateral circuit, involving the inferior parietal lobule and ventral premotor area 6 (PMv) (dorsolateral visual stream), with grasping. Area V6A is located in the caudalmost part of the superior parietal lobule, so it belongs to the dorsomedial visual stream; it contains neurons sensitive to visual stimuli (Galletti et al. 1993, 1996, 1999) as well as cells sensitive to the direction of gaze (Galletti et al. 1995) and cells showing saccade-related activity (Nakamura et al. 1999; Kutz et al. 2003). Area V6A contains also arm-reaching neurons likely involved in the control of the direction of the arm during movements towards objects in the peripersonal space (Galletti et al. 1997; Fattori et al. 2001). The present results confirm this finding and demonstrate that during the reach-to-grasp the V6A neurons are also modulated by the orientation of the wrist. Experiments were approved by the Bioethical Committee of the University of Bologna and were performed in accordance with National laws on care and use of laboratory animals and with the European Communities Council Directive of 24th November 1986 (86/609/EEC), recently revised by the Council of Europe guidelines (Appendix A of Convention ETS 123). Experiments were performed in two awake Macaca fascicularis. Each monkey was trained to sit in a primate chair with the head restrained to perform reaching and grasping arm movements in complete darkness while gazing a small fixation point. The object to be grasped was a handle that could have different orientation. We recorded neural activity from 163 neurons of the anterior parietal sulcus; 116/163 (71%) neurons were modulated by the reach-to-grasp task during the execution of the forward movements toward the target (epoch MOV), 111/163 (68%) during the pulling of the handle (epoch HOLD) and 102/163 during the execution of backward movements (epoch M2) (t_test, p ≤ 0.05). About the 45% of the tested cells turned out to be sensitive to the orientation of the handle (one way ANOVA, p ≤ 0.05). To study how the distal components of the movement, such as the hand preshaping during the reaching of the handle, could influence the neuronal discharge, we compared the neuronal activity during the reaching movements towards the same spatial location in reach-to-point and reach-to-grasp tasks. Both tasks required proximal arm movements; only the reach-to-grasp task required distal movements to orient the wrist and to shape the hand to grasp the handle. The 56% of V6A cells showed significant differences in the neural discharge (one way ANOVA, p ≤ 0.05) between the reach-to-point and the reach-to-grasp tasks during MOV, 54% during HOLD and 52% during M2. These data show that reaching and grasping are processed by the same population of neurons, providing evidence that the coordination of reaching and grasping takes place much earlier than previously thought, i.e., in the parieto-occipital cortex. The data here reported are in agreement with results of lesions to the medial posterior parietal cortex in both monkeys and humans, and with recent imaging data in humans, all of them indicating a functional coupling in the control of reaching and grasping by the medial parietofrontal circuit.

Photo- and redox-active supramolecular systems containing metal complexes

The aim of this Ph.D. project has been the photophysical and photochemical characterization of new photo- and redox-active supramolecular systems. In particular we studied two different classes of compounds: metal complexes and dendrimers. Two different families of bis-cyclometalated neutral Ir(III) complexes are presented and their photophysical properties are discussed. The first family of complexes contains two 2-phenylpyridyl (ppy) or 2-(4,6-difluorophenyl)pyridyl (F2ppy) cyclometalated ligands and an ancillary ligand constituted by a phenol-oxazoline (phox), which can be substituted in the third position with a fluorine group (Fphox). In the second part of this study, we present another family of bis-cyclometalated Ir(III) complexes in which the ancillary ligand could be a chiral or an achiral bis-oxazoline (box). We report on their structural, electrochemical, photophysical, and photochemical properties. Complexes containing phox and Fphox ancillary ligands show blue luminescence with very high quantum yield, while complexes with box ligands do not show particularly interesting photophysical properties. Surprisingly these complexes give an unexpected photoreaction when irradiated with UV light in presence of dioxygen. This photoreaction originates a stable, strong blue emitting and particularly interesting photoproduct. Three successive generations of a family of polyethyleneglycol (PEG)-coated Pd(II) tetrabenzoporphyrin (PdTBP)-based dendritic nanoprobes are presented, and their ability to sensitize singlet oxygen and inflict cellular photodamage are discussed. It was found that the size of the dendrimer has practically no effect on the singlet oxygen sensitization efficiency, that approximate the unity, in spite of the strong attenuation of the triplet quenching rate with an increase in the dendrimer generation. Nevertheless, when compared against a commonly used singlet oxygen sensitizer, as Photofrin, the phosphorescent probes were found to be non-phototoxic. The lack of phototoxicity is presumably due to the inability of PEGylated probes to associate with cell surfaces and/or penetrate cellular membranes. The results suggest that protected phosphorescent probes can be safely used for oxygen measurements in biological systems in vivo. A new family of two photoswitchable (G0(Azo) and G1(Azo)) dendrimers with an azobenzene core, two cyclam units as coordination sites for metal ions, and luminescent naphthalene units at the periphery have been characterized and their coordination abilities have been studied. Because of their proximity, the various functional groups of the dendrimer may interact, so that the properties of the dendrimers are different from those exhibited by the separated functional units. Both the naphthalene fluorescence and the azobenzene photoisomerization can be observed in the dendrimer, but it has been shown that (i) the fluorescent excited state of the naphthalene units is substantially quenched by excimer and exciplex formation and by energy transfer to the azobenzene units, and (ii) in the latter case the fluorescence quenching is accompanied by the photosensitized isomerization of the trans → cis, and, with higher efficiency, the cis → trans reaction. Complexation of these dendrimers, both trans and cis isomers, with Zn(II) ions shows that complexes of 1:1 and 2:1 metal per dendrimer stoichiometry are formed showing different photophysical and photochemical properties compared to the corresponding free ligands. Practically unitary efficiency of the sensitized isomerization of trans → cis and cis → trans reaction is observed, as well as a slight increase in the naphthalene monomer emission. These results are consistent with the coordination of the cyclam amine units with Zn(II), which prevents exciplex formation. No indication of a concomitant coordination of both cyclam to a single metal ion has been obtained both for trans and cis isomer.

Die Überarbeitung der Fernsehrichtlinie unter Berücksichtigung der EuGH-Entscheidungen zur bisherigen Fassung

Gegenstand der vorliegenden Arbeit ist die Überarbeitung der Richtlinie 89/552/EWG des Rates zur Koordinierung bestimmter Rechts- und Verwaltungsvorschriften der Mitgliedstaaten über die Ausübung der Fernsehtätigkeit, welche aus praktikablen Gründen meist als „(EG-)Fernsehrichtlinie“ bezeichnet wird. Sie bildet den Eckpfeiler der audiovisuellen Politik der EU. Seit Erlass der Fernsehrichtlinie im Jahre 1989 bewirkt der technologische Fortschritt jedoch zunehmend enorme Veränderungen nicht nur im Bereich des klassischen Fernsehens, sondern auch und vor allem im Bereich der neuen Medien. Ausgangspunkt hierfür ist die Verbesserung der Digitaltechnologie, die ihrerseits wiederum technische Konvergenzprozesse begünstigt. Diese Entwicklungen führen nicht nur zu einer Vervielfachung von Übertragungskapazitäten und –techniken, sondern ermöglichen neben neuen Formen audiovisueller Angebote auch die Entstehung neuer Dienste. Unsere Medienlandschaft steht vor „epochalen Umbrüchen“. Im Hinblick auf diese Vorgänge wird seit geraumer Zeit eine Überarbeitung der EG-Fernsehrichtlinie angestrebt, um dem technologischen Fortschritt auch „regulatorisch“ gerecht werden zu können. Diesem Überarbeitungsprozess möchte sich die vorliegende Arbeit widmen, indem sie die Fernsehrichtlinie in einem ersten Teil sowohl inhaltlich wie auch hinsichtlich ihrer Entstehungsgeschichte und der zu ihr ergangenen EuGH-Entscheidungen erläutert. Anschließend werden alle Überarbeitungsvorgänge der Fernsehrichtlinie seit 1997 dargestellt, um sodann die aktuellen Reformansätze analysieren und bewerten zu können. Aus zeitlichen Gründen (der neue Richtlinienvorschlag der Kommission vom 13. Dezember 2005 wurde ca. 2 Wochen vor dem Abgabetermin der Arbeit verabschiedet) sind die Ausführungen zum Entwurf der neuen „Richtlinie über audiovisuelle Mediendienste“ allerdings relativ knapp gehalten.

Polysulfurated aromatic compounds: preparation and photophysical properties

The aim of this thesis was the synthesis and photophysical characterization of some new polysulfurated aromatic compounds: this class of molecules can offer intriguing properties, potentially useful for the construction of new materials for optoelectronic devices. Two main families of compounds have been synthesized: the first is represented by a series of small molecular asterisks, with peripheral aromatic units, showing luminescence in solid phase or in highly rigid conditions. All compounds with peripheral substituents display an AIE behavior (Aggregation Induced Emission) with radiative deactivation of the triplet states. Taking inspiration from these smaller asterisks, a larger molecule with the same geometry has been designed, decorated with terpyridyl moieties as the outermost units: this compound shows great affinity for the coordination of several transition metal ions, changing luminescence properties after the interaction with zinc ions. With the same intentions, a tetrasulfurated pyrene-core molecule with terpyridyl external units has been synthesized and isolated: this ligand exhibits good coordination capabilities towards transition metal ions, giving rise to luminescent nanoaggregates upon addition of zinc(II), characterized by DLS and AFM microscopy. In addition a NIR emission is recorded after coordination of neodymium(III), showing evidence of an intramolecular energy transfer process.

Cantate dialogiche e serenate (1706-1710) di Georg Friedrich Händel

La dissertazione è uno studio monografico delle cantate dialogiche e delle serenate a più voci e strumenti composte da Händel in Italia negli anni 1706-1710. Insieme ai drammi per musica e agli oratori coevi, le quattro cantate "Aminta e Fillide" HWV 83, "Clori, Tirsi e Fileno" HWV 96, "Il duello amoroso" HWV 82, "Apollo e Dafne" HWV 122 e le due serenate "Aci, Galatea e Polifemo" HWV 72 e "Olinto pastore arcade alle glorie del Tebro" HWV 143 costituiscono le prime importanti affermazioni di Händel come compositore di musica vocale. Le sei composizioni sono state studiate sotto l’aspetto storico-letterario, drammaturgico-musicale e della committenza, con l’obiettivo di individuare intersecazioni fra questi piani. I testi poetici, di cui si è curata l’edizione, sono stati analizzati da un punto di vista storico e stilistico e collocati nel particolare contesto romano del primo Settecento, in cui la proibizione di ogni spettacolo teatrale determinò, sotto la spinta di una raffinata committenza, un ‘drammatizzazione’ dei generi della cantata e della serenata. L’analisi musicale di ciascuna composizione è stata dunque finalizzata a una lettura ‘drammaturgica’, che ha portato alla individuazione dei dispositivi di ascendenza teatrale nella scelte compositive di Händel. Lo studio si conclude con un selettivo confronto con le cantate e le serenate scritte negli stessi anni a Roma da Alessandro Scarlatti.

"Tra centro e periferia" Istituzioni e processi di industrializzazione nella Sicilia del secondo dopoguerra

In Sicilia lo strumento principale che ha caratterizzato le modalità d’intervento dei poteri pubblici in economia è stato quello della partecipazione diretta o indiretta, quello cioè della Regione che si propone come ente fautore del sostegno allo sviluppo dell’industria e successivamente come soggetto imprenditore. Le formule organizzative attraverso le quali si è concretizzato l’intervento regionale in economia furono la società per azioni a partecipazione regionale, l’azienda autonoma regionale e l’ente pubblico regionale1. La storia dello sviluppo economico siciliano nel secondo dopoguerra conferma come il ricorso allo strumento dell’ente pubblico economico sia stato molto frequente nella realtà locale come, peraltro, anche in altre Regioni d’Italia. Tracce, queste, di una vicenda storica che intuiamo subito avere complesse implicazioni tali da generare la necessità di interrogarsi sul modo nel quale le istituzioni politiche hanno influito sulle dinamiche economiche siciliane nel secondo dopoguerra; per quanto noti e approfonditi siano stati infatti gli elementi caratterizzanti e i percorsi peculiari dello sviluppo economico siciliano, rimangono scarsamente approfonditi il tenore dei rapporti e i nessi politici, istituzionali ed economici tra centro e periferia, in altre parole rimane ancora parzialmente inesplorata quella parte dell’indagine inerente l’evoluzione dei processi di industrializzazione della Sicilia nel secondo dopoguerra attuata parallelamente dalle autorità regionali e dallo Stato attraverso i loro enti e strumenti. È lecito chiedersi quali siano stati i tempi, le modalità, gli ostacoli e gli eventuali risultati delle azioni di pianificazione intraprese dai poteri pubblici centrali e regionali nella prospettiva dello sviluppo economico del territorio; il coordinamento delle azioni di promozione del progresso industriale si presentava in tal senso, sin dall’inizio, come una delle sfide fondamentali per un adeguato e consistente rilancio economico delle aree più arretrate del Mezzogiorno italiano; ecco che lo studio dei provvedimenti legislativi emanati rappresenta un approfondimento indispensabile e obiettivo primario di questo lavoro.

Magnetische Wechselwirkung Spin-Austauschgekoppelter Systeme mit Nitroxid und Nitronyl-Nitroxid Radikalen

Bei der Untersuchung molekularer magnetischer Materialien spielen Metall-Radikal Verbindungen eine bedeutende Rolle. Ein Forschungsschwerpunkt stützt sich auf die Familie der Nitronyl-Nitroxid (NIT) Radikale, die sich durch eine hohe chemische Stabilität auszeichnen. Im sogenannten „Metall-Radikal Ansatz“ wurden die starken Austauschwechselwirkungen zwischen stabilen Radikalen und Übergangsmetallionen in mehrdimensionalen Netzwerken ausgiebig untersucht. Um diese Netzwerke mit NIT Radikalen aufzubauen, müssen zusätzliche funktionelle Gruppen, mit einem Abstand zur spintragenden Einheit, in das Molekül eingebaut werden. Dies kann zu einer zusätzlichen schwachen Spinaustauschwechselwirkung führen. Um diese Wechselwirkung zwischen Metalldimeren mit einem einzelnen Benzoat annalogen NIT-Radikal zu untersuchen, wurden dimere Mangan(II), Kobalt(II) und Zink(II) Komplexe mit dem Chelatliganden N,N,N',N'-Tetrakis(2-benzimid-azolylalkyl)-2-hydroxy-1,3-diamino-propan synthetisiert und zusätzlich über eine periphere Carboxylat Gruppe eines NIT Radikals verbrückt.rnDie Messungen der magnetischen Suszeptibilität weisen auf eine dominante antiferromagnetische Wechselwirkung in der Metall-Radikal Verbindung hin, bei der es sich um die Spin-Austauschwechselwirkung innerhalb des Metalldimers handelt. Durch den Vergleich mit analogen Nitrobenzoat- verbrückten Mangan(II) und Kobalt(II) Verbindungen konnte gezeigt werden, dass keine Metall-Radikal Wechselwirkung beobachtet wird, obwohl eine Wechselwirkung der pi*-orbitale mit den delokalisierten pi-System des Phenylrings durch Spin-Polarisation grundsätzlich möglich ist. Auch ESR - Messungen bestätigen dies, da der Spingrundzustand das anisotrope Signal des freien NIT Radikals aufweist. Das Radikal verhält sich somit wie ein isoliertes S=1/2 Spin-Zentrum, was zusätzlich durch DFT-Rechnungen bekräftigt werden konnte. Zusammenfassend führt also die Koordination eines NIT-Benzoats an ein antiferromagnetisch gekoppeltes Metalldimer nur zur Anhebung des Spingrundzustandes und hat keinen signifikanten Effekt auf die Austauschwechselwirkung. Um trotzdem eine Metall-Radikal Wechselwirkung beobachten zu können, ist es notwendig Koordinationsverbindungen zu synthetisieren in denen hohe Spingrundzustände besetzt werden. Dies trifft auf das analoge Kupferdimer zu, wofür eine ferromagnetische Wechselwirkung zu beobachten ist.rnNach den Regeln der Spin-Polarisation müsste die Verkürzung des Austauschpfades um eine Bindung zu einer Umkehrung des Vorzeichens der magnetischen Wechselwirkung führen. Diese Verkürzung kann man durch die Verwendung des alternativen stabilen NOA-Radikals (tert-Butyl Nitroxid) erreichen. Sowohl das NIT als auch das NOA-Radikal werden an ein Kupfer(II)-dimer koordiniert, das durch die Verwendung des oben erwähnten N6O-Liganden gebildet wurde. In der Modellverbindung, ohne einen paramagnetischen Substituenten am Benzoat, zeigen die Kupferionen eine ferromagnetische Wechselwirkung mit einem Triplett Grundzustand, dessen Existenz durch die Messung der magnetischen Suszeptibilität und ESR-Spektroskopie belegt werden kann. Aufgrund der nahezu identischen Koordinationsumgebung bleibt bei allen synthetisierten Verbindungen die Kupfer-Kupfer Wechselwirkung dabei gleich. Die Daten von ESR und magnetischen Messungen zeigen weiterhin auf eine signifikante zusätzliche Metall-Radikal Wechselwirkung hin. Bei der NIT-Verbindung ist diese Austauschwechselwirkung schwach antiferromagnetisch, während die NOA-Verbindung eine schwache ferromagnetische Kopplung aufzeigt. Diese Resultate können durch DFT Rechnungen bekräftigt werden. Der Vorzeichenwechsel des Kopplungsparameters kann durch die Verkürzung des Austauschpfades vom NIT zum NOA-Benzoat um eine Bindung erklärt werden. Durch die Wahl von geeigneten Radikal- Liganden und Metallionen, zeigt sich die Möglichkeit, Systeme zu erzeugen, in denen die Radikal-Metall Wechselwirkung auch über größere Distanzen den Spin-Grundzustand des gesamten Systems signifikant beeinflussen kann. die Anwendung dieses Konzeptes auf Metall-Radikal Cluster System sollte Von großem Interesse sein.rn

All'origine dello squilibrio di potere negoziale della parte agricola nella food supply chain: il caso della suinicoltura in Emilia-Romagna

Il settore suinicolo ricopre un ruolo rilevante nel contesto nazionale, con ricadute economiche e sociali di primaria importanza in varie regioni. Tuttavia da alcuni anni il settore si trova in crisi a causa dell’instabilità dei mercati internazionali, dello scarso coordinamento tra gli attori della filiera, della progressiva riduzione della redditività dei prodotti trasformati a Denominazione di Origine, della mancata valorizzazione dei tagli di carne fresca, nonché della difficoltà di aggredire i mercati esteri. Altre criticità riguardano la distribuzione del valore lungo la filiera e la scarsa efficacia delle politiche di coordinamento finora adottate. L'obiettivo della ricerca è quello di identificare gli elementi che possono garantire maggiore equilibrio di potere negoziale tra allevatori suinicoli e macellatori rispetto alla situazione attuale: verificati gli elementi critici che caratterizzano la relazione commerciale tra allevatori e macellatori, si avanzano alcune proposte operative utili al superamento delle fratture tra la componente agricola e quella dei macelli in Emilia Romagna. La struttura della tesi è la seguente: (capitolo 1) si descrive il quadro economico del settore suinicolo a livello internazionale e nazionale. Successivamente (capitolo 2) si passano in rassegna le teorie economiche utili a comprendere le ragioni alla base del malfunzionamento dei rapporti tra gli attori della filiera agroalimentare, mentre nel terzo capitolo è richiamato il quadro normativo comunitario, nazionale e regionale all’interno del quale tali relazioni si configurano. Nel quarto capitolo si elabora un modello interpretativo al fine di spiegare le fratture che oggi contraddistinguono le relazioni in essere tra gli attori della filiera: il “modello delle fratture”. Alla luce di questa concettualizzazione è stata svolta un’indagine diretta svolta presso gli operatori aderenti all’Organizzazione Interprofessionale del Gran Suino Italiano, i cui risultati hanno consentito di valutare l’efficacia del modello interpretativo e di fornire indicazioni migliorative della strategia di governance delle relazioni tra allevatori e macellatori.