Il tesoro di Hoxne

In un momento imprecisato delle prima metà del V secolo d.C., in un baule ligneo misurante circa 60x 45x 30 cm, qualcuno aveva depositato per poi sotterrarli insieme al contenitore stesso, più di 150 oggetti in metallo prezioso tra gioielli in oro e vasellame e posate in argento, insieme a più di 15.000 monete, pure in oro e argento. Circa 27 kg, quindi, di metallo prezioso sottoforma di oggetti di grande valore che dovevano costituire il patrimonio non è possibile dire con certezza se familiare o di uno o più singoli individui, che decisero di affidarlo temporaneamente alla terra per proteggerlo e con l’intento di venirlo poi a recuperare. Il tutto in quell’area della provincia di Britannia oggi conosciuta come la contea del Suffolk, nei pressi dell’odierna cittadina di Hoxne, nell'East Anglia. Questo lavoro si prefigge come obiettivo quello di fornire al tesoro di Hoxne un contesto il più possibile completo, che aiuti a comprendere appieno non solo la natura del tesoro stesso, ma anche le motivazioni che potrebbero stare alla base della sua deposizione e che, in generale, starebbero alla base della deposizione del notevole numero di tesori (più di un centinaio) deposti nella stessa area (quella dell’East Anglia) proprio in quest’epoca (la seconda metà del IV e l’inizio del V secolo). Il punto di partenza di quest’analisi è indubbiamente la catalogazione degli oggetti stessi che compongono il tesoro. Divisi per materiale e tipologia ed analizzati sulla base della loro funzione, stato di conservazione e modalità di deposizione, questi ci forniscono una prima serie di informazioni e indizi sui possibili proprietari, sulla possibile cronologia e sulle modalità del loro utilizzo durante la loro “vita”. Dal punto di vista stilistico, manca un tesoro di riferimento a cui paragonare quello di Hoxne (il tesoro proveniente dalla Britannia romana più simile conosciuto, dal punto di vista soprattutto della modalità di lavorazione di certi oggetti, è quello di Thetford) e non sempre, pertanto, è possibile trovare dei parallelismi per questi oggetti. Laddove particolari analogie sono state rinvenute con oggetti di altri tesori romani della Britannia o dell'area gallica, queste sono state messe in rilievo, soprattutto allo scopo di attestare parallelismi tipologici più che cronologici. Il punto di partenza per delle ipotesi cronologiche è, invece, il terminus post quem determinato dalle monete più recenti del 407-408 d.C. Nella seconda parte di questo scritto, dopo una breve premessa sui precedenti trecento anni di romanità della Britannia, si analizzano in dettaglio gli avvenimenti storici dalla seconda metà del IV secolo in poi, per cercare di raccogliere il maggior numero di informazioni possibile sull’epoca in cui il tesoro fu deposto. Questa analisi storica, accompagnata da quella topografica e stratigrafica, permette di delineare un quadro abbastanza completo attorno alla deposizione del tesoro stesso, tale da contestualizzarlo ed inserirlo tra altri numerosi tesori analogamente deposti nella stessa area geografica nel corso della stessa epoca. Solo nell’ambito di un contesto il più possibile completo, infatti, è possibile comprendere appieno il tesoro non solo come accumulo di oggetti preziosi che aggiunge un elemento fondamentale alla cultura materiale della Britannia romana, ma anche come parte di un fenomeno storico più ampio che ha le sue radici nello spinoso problema della fine della provincia romana di Britannia. Il grande valore e l’eccezionalità del tesoro di Hoxne stanno, infatti, sia nella preziosità intrinseca degli oggetti stessi e nel loro notevole numero, sia nel fatto che, appartenendo ad un’epoca così povera di fonti scritte e di informazioni storiche, esso costituisce un elemento fondamentale per ricostruire un’importantissima parte della storia dell’Impero Romano

Enzyme kinetics, structural analysis and molecular modeling studies on a series of Schistosoma mansoni PNP inhibitors

The enzyme purine nucleoside phosphorylase from Schistosoma mansoni (SmPNP) is an attractive molecular target for the development of novel drugs against schistosomiasis, a neglected tropical disease that affects about 200 million people worldwide. In the present work, enzyme kinetic studies were carried out in order to determine the potency and mechanism of inhibition of a series of SmPNP inhibitors. In addition to the biochemical investigations, crystallographic and molecular modeling studies revealed important molecular features for binding affinity towards the target enzyme, leading to the development of structure-activity relationships (SAR).A enzima purina nucleosídeo fosforilase do parasita Schistosoma mansoni (SmPNP) é um alvo molecular atrativo para o desenvolvimento de candidatos a novos fármacos para o tratamento da esquistossomose, doença tropical negligenciada que afeta mais de 200 milhões de pessoas em todo mundo. No presente trabalho, estudos de cinética enzimática foram conduzidos para a determinação da potência e do mecanismo de inibição de uma série de inibidores da enzima SmPNP. Além das investigações bioquímicas, estudos cristalográficos e de modelagem molecular revelaram importantes bases moleculares para a afinidade de ligação frente à enzima alvo, levando ao desenvolvimento de relações entre a estrutura e atividade (SAR).(FAPESP) São Paulo Research FoundationFundação de Amparo à Pesquisa do Estado da Bahia (FAPESB)(CNPq) National Council for Scientific and Technological Developmen

Finding What Works, Works; But Doing It Requires Self-Control: An Evaluation of a Solution-Focused Online Intervention to Increase Goal Striving

Solution-Focus (SF) is an evidence-based interviewing protocol that increases goal commitment and facilitates goal striving, yet few attempts have been made to use it in scalable interventions. This study tested a SF-inspired online intervention (Solution-Focus with Implementation Intentions, SFII) designed to enhance academic goal striving. SFII led students to find study strategies that worked for them and then it directed them to formulate implementation intentions (II) specifying when and where to replicate those strategies. Undergraduate students (N = 170) were randomly assigned to either SFII or an essay-writing condition. Daily study goal achievement for the following week was not significantly different between the two groups; however, students who carried out II did better in achieving their study goal than those who did not execute them, both within the SFII condition (d = 0.55, p = .042) and across the sample (partial h2 = .02, p = .047). Students in the SFII condition who followed through had on average higher levels of self-control than those who did not (d = 0.73, p = .003). These findings suggest that the SF distinctive approach might have helped in the formulation of effective II, and that carrying them out was mostly a matter of self-control

Acute effect of pore-forming Clostridium perfringens ε-toxin on compound action potentials of optic nerve of mouse

ε-Toxin is a pore forming toxin produced by Clostridium perfringens types B and D. It is synthesized as a less active prototoxin form that becomes fully active upon proteolytic activation. The toxin produces highly lethal enterotoxaemia in ruminants, has the ability to cross the blood–brain barrier (BBB) and specifically binds to myelinated fibers. We discovered that the toxin induced a release of ATP from isolated mice optic nerves, which are composed of myelinated fibers that are extended from the central nervous system. We also investigated the effect of the toxin on compound action potentials (CAPs) in isolated mice optic nerves. When nerves were stimulated at 100 Hz during 200 ms, the decrease of the amplitude and the area of the CAPs was attenuated in the presence of ε-toxin. The computational modelling of myelinated fibers of mouse optic nerve revealed that the experimental results can be mimicked by an increase of the conductance of myelin and agrees with the pore forming activity of the toxin which binds to myelin and could drill it by making pores. The intimate ultrastructure of myelin was not modified during the periods of time investigated. In summary, the acute action of the toxin produces a subtle functional impact on the propagation of the nerve action potential in myelinated fibers of the central nervous system with an eventual desynchronization of the information. These results may agree with the hypothesis that the toxin could be an environmental trigger of multiple sclerosis (MS)

An innovative bio-engineering retaining structure for supporting unstable soil

The paper presents a new prefabricated bio-engineering structure for the support of unstable soil. This prefabricated structure is made of a steel frame which is completely filled with soil and a face made of tree trunks among which scions or autochthonous bushes are planted. Due to the difficulties in interpreting the complex interaction between soil and structure during the installation and lifetime, an in situ test was carried out in order to evaluate the state of stress in the steel frame and to understand the global behavior of the structure under service loads. On the basis of the obtained results, a procedure for checking the structure safety was proposed and discussed. An easy design method was developed during the research. Moreover, the use of this type of prefabricated structure shows several advantages, such as good performances in terms of stabilizing effects, and easy assembly and transport

Galaxy clusters in different dynamical state: a multiband view from MeerKAT and uGMRT

Galaxy clusters are the largest gravitationally bound systems in the Universe, they are special laboratories where is it possible to investigate the evolution and the properties of galaxies in different environments, starting from their centre, going out to the virial radius and beyond. The properties of radio galaxies can be related to their environment and its dynamical status: nowdays, understand whether the observed properties of radio galaxies arise at formation (nature scenario), or they are an end-product of physical processes (nurture scenario) coming into play after galaxies have become part of a `group' or a `cluster' is difficult and much debated. We started this work, analyzing a sample of eleven Brightes Cluster Galaxies (BCGs) from ten galaxy clusters in the redshift range 0.2 < z < 0.4. They were selected because of the overlap between the Extended GMRT Radio Halo Survey (EGRHS) and the Cluster Lensing and Supernovae Survey with Hubble (CLASH). The main aim is to examine the radio properties of these galaxies considered `special' because of their position at the very centre of galaxy cluster potential well. In particular, to understand whether the main mechanism responsible for the radio emission, when detected, is mainly due to AGN activity or to Star Formation activity and which is the interplay between the two mechanisms, since both are of fundamental importance for the feedback phenomena

Axon terminals control endolysosome diffusion to support synaptic remodelling

Endolysosomes are acidic organelles formed by the fusion ofendosomes with lysosomes. In the presynaptic compartment theycontribute to protein homeostasis, the maintenance of vesiclepools and synaptic stability. Here, we evaluated the mobility ofendolysosomes found in axon terminals of olfactory sensoryneurons ofXenopus tropicalistadpoles. F-actin restricts themotion of these presynaptic acidic organelles which is characterized by a diffusion coefficient of 6.7 × 1023μm2⋅s21. Local injection of secreted protein acidic and rich in cysteine (SPARC) inthe glomerular layer of the olfactory bulb disrupts the structureof synaptic F-actin patches and increases the presence andmobility of endolysosomal organelles found in axon terminals.The increased motion of endolysosomes is localized to the presynaptic compartment and does not promote their access toaxonal regions for retrograde transportation to the cell body. Local activation of synaptic degradation mechanisms mediated by SPARC coincides with a loss of the ability of tadpoles to detect waterborne odorants. Together, these observations show that the diffusion of presynaptic endolysosomes increases during conditions of synaptic remodelling to support their local degradativeactivity

Abnormal expression and distribution of MMP2 at initial stages of Alzheimer's disease-related pathology

Previous studies have shown that metalloproteinases (MMPs) participate in the clearance of amyloid-β (Aβ) in Alzheimer's disease (AD); MMP2 and MMP3 cleave soluble Aβ, and both MMP9 and MT1-MMP are able to degrade soluble and fibrillar forms of Aβ. The present study shows increased expression levels of active MMP2 in the entorhinal cortex at early stages of AD-related pathology (Braak and Braak stages I/II-0 and III/IV-A) as revealed by western blotting and gelatin zymography. Confocal microscopy discloses co-localization of MMP2 and phospho-tau in neurofibrillary tangles and dystrophic neurites. MMP2 has the capacity to cleave recombinant tau in vitro in a dose-dependent manner, consistent with a physiological function of MMP2 in normal tau proteolysis. However, MMP2 does not cleave hyperphosphorylated and dephosphorylated tau from enriched paired helical filament fractions. These observations raise the possibility that accumulation of MMP2 in neurofibrillary tangles and concomitant loss of proteolytic capacity on tau protein is a response geared to eliminating production of toxic truncated tau species in AD brains. Keywords: Alzheimer's disease, metalloproteinases, MMP2, neurofibrillary tangles, ta