4,865 research outputs found
Status and prospects for the LHCb upgrade
High-precision measurements performed by the LHCb collaboration have opened a
new era in charm physics. Several crucial measurements, particularly in
spectroscopy, rare decays and CP violation, can benefit from the increased
statistical power of an upgraded LHCb detector. The upgrade of LHCb detector,
its software infrastructure, and the impact on charm physics are discussed in
detail.Comment: to appear in the proceedings of The 6th International Workshop on
Charm Physics (CHARM 2013
LikeStarter: a Smart-contract based Social DAO for Crowdfunding
Crowdfunding has become a popular form of collective funding, in which small
donations or investments, made by groups of people, support the development of
new projects in exchange of free products or different types of recognition.
Social network sites, on the other hand, promote user cooperation and currently
are at the basis of any individuals cyber-interactions. In this paper, we
present LikeStarter, a blockchain-based decentralized platform that combines
social interactions with crowdfunding mechanisms, allowing any user to raise
funds while becoming popular in the social network. Being built over the
Ethereum blockchain, LikeStarter is structured as a Decentralized Autonomous
Organization (DAO), that fosters crowdfunding without the intervention of any
central authority, and recognizes the active role of donors, enabling them to
support artists or projects, while making profits.Comment: Proceedings of the 2st Workshop on Cryptocurrencies and Blockchains
for Distributed Systems (CryBlock'19). Paris, France, 29 April, 201
Pozzi sacri: ipotesi ricostruttive
Già dal 1974 mi ero posto il problema della ricostruzione grafica, o restituzione che dir si voglia, dei pozzi sacri (o "templi a pozzo") della Sardegna nuragica; ma solo nel 1980 avevo tradotto graficamente la mia ipotesi in un disegno - che per gran parte qui riconfermo nella sua relativa validità - concernente la struttura generale originaria di questa categoria di monumenti. Tutto ciò riguardava anche le fonti sacre, che, per essere l'acqua
sorgiva più facilmente accessibile rispetto a quella che viene da falda freatica, e perciò necessitando - quand'anche essa ci sia - di una scala molto breve, risultano essere, per dir così, dei pozzi sacri in miniatura.
Nella mia ricostruzione grafica, sia passata che presente, del pozzo sacro di Santa Vittoria di Serri-NU mi sono
limitato agli elementi principali dell'architettura, trascurando persino, volutamente, sia il recinto o temenos ellittico che racchiude l'edificio - data la sua modesta rilevanza architettonica e perché
deve trattarsi di un'aggiunta successiva, piuttosto recente - sia il problema della sistemazione originaria di altri elementi non direttamente riferibili all'edificio: quali i betili-torre, o modellini in pietra di nuraghi, e i bronzetti; e infine le due statue di toro in calcare
(conservate in due distinti frammenti). Comunque questi due tori potevano stare, uno per lato davanti alle due ante, sulla fronte del pozzo, all'incirca come i leoni alati assiri del palazzo di Nimrud o quelli stilofori delle chiese romaniche
Studi sul genere Agaricus. II. A. heterocystis Heinem et Goos., una specie africana naturalizzata in Sardegna ed A. fragilivolvatus, nuova specie della sezione Clarkeinda
Agaricus heterocystis, una espècie d'origen africà que pertany a la secció Arvenses, sembla haver-se natural itzat a Sardenya, on ha estat recol·lectada diverses vegades. Es presenta una descripció d'aquesta espècie feta a partir del material sard. Es descriu A. fragilivolvatus com a espècie nova de la secció Clarkeinda, i es discuteix la seva delimitació respecte dels taxons propers.Agaricus heterocystis, an african species belonging in the section Arvenses, seems to be naturalized in Sardinia where it has often been recorded. A description of the sardinian collections of the species is given. A. fragilivolvatus is described as a new species into the section Clarkeinda and the delimitation from similar entities is discussed
Studi sul genere Agaricus. II. A. heterocystis Heinem et Goos., una specie africana naturalizzata in Sardegna ed A. fragilivolvatus, nuova specie della sezione Clarkeinda
Agaricus heterocystis, una espècie d'origen africà que pertany a la secció Arvenses, sembla haver-se natural itzat a Sardenya, on ha estat recol·lectada diverses vegades. Es presenta una descripció d'aquesta espècie feta a partir del material sard. Es descriu A. fragilivolvatus com a espècie nova de la secció Clarkeinda, i es discuteix la seva delimitació respecte dels taxons propers.Agaricus heterocystis, an african species belonging in the section Arvenses, seems to be naturalized in Sardinia where it has often been recorded. A description of the sardinian collections of the species is given. A. fragilivolvatus is described as a new species into the section Clarkeinda and the delimitation from similar entities is discussed
Ecologia e tassonomia del genere Rhodocybe R. Maire (Basidiomycetes, Entolomataceae) in Sardegna
The species of the genus Rhodocybe occurring in Sardinia are keyed-in, described and taxonomically discussed. At the time being 16 entities are known to occurr in the Isle
Ecologia e tassonomia del genere Rhodocybe R. Maire (Basidiomycetes, Entolomataceae) in Sardegna
The species of the genus Rhodocybe occurring in Sardinia are keyed-in, described and taxonomically discussed. At the time being 16 entities are known to occurr in the Isle
Il Sostegno italiano alla causa nazionale egiziana nel XIX secolo
Le relazioni tra l’Egitto e l’Italia affondano le radici nell’antichità romana e ancora in epoche più remote, se si accetta l’identificazione dei nomi di alcuni dei “Popoli del Mare”, che le fonti dell’Egitto faraonico riportano,
con gli abitanti presenti in certe regioni italiane prima dell’emergere di Roma: Teresh - Etruschi in Toscana ed Etruria, Sheklesh - Siculi in Sicilia e Sherden/Shardana - Sardi in Sardegna. I rapporti tra queste due sponde del
Mediterraneo vengono consolidate in epoca medioevale quando le città marinare italiane Venezia, Genova, Pisa e Amalfi fondano i loro empori commerciali d’Oriente e l’Egitto diviene uno snodo essenziale delle merci e
dei prodotti provenienti dall’Oriente e dall’India, dall’Arabia e dall’Africa Orientale, rimanendo un punto di forza dei traffici commerciali per la Repubblica di Venezia e per la Toscana fino a verso la metà del 1700.
Proiettato al centro delle relazioni internazionali dalla spedizione di Napoleone Bonaparte nel 1798, l’Egitto attira l’immediato interesse delle potenze europee ed in particolare della Gran Bretagna e della Francia, che
agli inizi del XIX puntano a spartirsi la gran parte dei territori dell’Asia e dell’Africa, continuando quella linea espansiva dell’Europa che nei secoli precedenti aveva portato alla colonizzazione delle Americhe. Dopo il ritiro
dei Francesi dall’Egitto (1801), obbligati ad abbandonare il Paese dai loroantagonisti britannici e dall’azione dell’esercito turco ottomano, la Porta nomina il comandante albanese Muḥammad ‘Alī, nel 1805, Pascià d’Egitto.
L’epoca di Muḥammad ‘Alī e la sua opera di riforme e di rinnovamento viene considerata dalle correnti storiografiche egiziane nazionaliste, il principio della storia moderna dell’Egitto. La modernizzazione che il nuovo
sovrano inizia, pur nell’ambito della sovranità formale dell’Impero ottomano al quale l’Egitto rimane legato, tocca i settori più importanti dell’economia e della società egiziana. Lo stato diviene proprietario delle
terre sottratte al controllo degli appaltatori (Multazimūn), viene stabilito un sistema di monopolio, si iniziano a costruire industrie finalizzate alla produzione dell’armamento dell’esercito, riorganizzato secondo modelli
europei, si pongono le basi per una industrializzazione dell’agricoltura, si scavano canali, si progetta una rete viaria nazionale, si gettano le fondamenta di un’istruzione laica di tipo europeo, si inviano e si ricevono
missioni in/e dall’Europa per studiare, conoscere e addestrarsi militarmente, secondo le tecniche più moderne.
Con i successori di Muḥammad ‘Alī, che governa dal 1805 al 1848, ‘Abbās I (1848-54), Sa‘īd (1854-63) e Ismā‘īl (1863-79) l’opera di modernizzazione verrà continuata e avrà nell’approvazione del progetto del taglio dell’Istmo di Suez e nei forti investimenti in agricoltura i simboli più
visibili. Saranno proprio i forti debiti contratti dalla Casa regnante per la realizzazione del Canale di Suez, inaugurato nel 1869, e il crollo dei prezzi
in agricoltura, trascinati al ribasso dal tracollo del cotone egiziano (1866), ad alimentare una grave crisi economica che metterà il Paese alla mercé dei
creditori europei. Questa epoca, fatta coincidere con l’arrivo al potere di Muḥammad ‘Alī, viene chiamata Nahḍa o ‘Risorgimento’ arabo e produce la nascita di una coscienza nazionale egiziana che avrà nella Thawra ‘urābiyya
(la ‘Rivoluzione di Aḥmad ‘Urābī 8 ) degli anni 1879-82 il primo dei momenti culminanti in cui si esprimerà al massimo grado. L’arco di tempo e gli avvenimenti compresi tra l’avvento al potere di Muḥammad ‘Alī e la rivolta
di Aḥmad ‘Urābī saranno i limiti in cui cercheremo di illustrare la posizione assunta dagli Italiani rispetto all’Egitto, basandoci prevalentemente sui documenti dell’Archivio Storico del Ministero degli Affari Esteri di Roma
Influence of Amphetamine-type stimulants in the Central Nervous System: abuse and neurotoxicity
Amphetamines are synthetic drugs characterized by their psychostimulants effects on the central nervous system (CNS), and include a wide range of substances such as alpha-methylphenethylamine or amphetamine (AMPH), N-methylamphetamine or methamphetamine (METH) and 3,4 methylenedioxymethamphetamine (MDMA) also known as “ecstasy”. The ATS, structurally, are a group of substances related to the compound known as β-phenethylamine (β-PEA), a naturally neurotransmitter in the body. Structural modifications on the aromatic ring of β-PEA create multiple synthetic derivatives with different pharmacological properties.
Various hypotheses regarding the mechanism responsible for METH and MDMA-induced neurotoxicity, have been proposed, including high release of monoamines (Dopamine (DA), serotonin (5-HT)), DA quinones formation synthesized by oxidation of the catechol ring of DA, excitatory amino acid glutamate (GLU) release and hyperthermia (Cadet et al., 2003; Miyazaki et al., 2006). It is likely that interactions between these factors trigger neurotoxicity induced by METH or MDMA. In addition, METH causes substantial changes in gene expression in some brain regions including the cortex, the dorsal caudate-putamen (CPu), and the midbrain (Cadet et al., 2009). These molecular changes include transient increases and decreases in the expression of various transcription factors, neuropeptides, and genes that participate in several biological functions (cell cycle, cell differentiation, signaling transduction), (Jayanthi et al., 2005).
In order to better understand the molecular mechanism that control the compulsive drug use, in collaboration with National Institutes on Drug abuse (NIDA, Baltimore) we have used the Self-administration (SA) paradigm in association with footshocks to induce negative consequences during METH SA. We investigated whether the compulsive METH taking under punishment can increase the expression of immediate early genes (IEGs) in the rat Nucleus Accumbens (NAc) and Prefrontal cortex (PFC), that are important areas involved in reward, memory, executive function, motivation and contribute to some of the differences in the circuit of addiction (Volkow & Morales 2015; Volkow et al., 2012; Adinoff 2004).
In the second and third study, performed at the University of Cagliari, we focused on MDMA treatment in mice in order to clarify the role played by this drug on neurotoxicity and motor behavior resulting from MDMA administration. Specifically, in the second study, considering the influence of the Ras Homolog enriched in striatum protein (Rhes) very important in the striatal functions, we studied the age-related survival of DA neurons in the substantia nigra (SNc) after MDMA treatment and the implication of this protein in neurodegenerative disease such as Parkinson Disease (PD). We have investigated the basal and the MDMA-induced neurotoxic effects in Rhes knock-out mice, male and female at different ages. Moreover, in an attempt to link neurochemical changes with behavioural modifications, this study investigated the motor activity.
The third study investigated the possible neuroprotective effect of metformin, an antidiabetic drug, against short and long-term neurotoxicity induced by MDMA, together with its role on MDMA-induced hyperthermia
SPATIAL ORGANIZATION OF LAMIN A/C IN HODGKIN’S LYMPHOMA AND MULTIPLE MYELOMA
Genomic Instability is a complex phenomenon observed both at the DNA and the chromosome level. It is responsible for the generation of mutations and chromosomal rearrangements, which can potentially lead to tumor development. A common genomic instability feature found in some malignant tumors is the shortening of the telomeres, the end of the chromosomes. Shortening of telomeres leads to the formation of anaphase bridges, subsequent breakage and initiation new breakage-bridge-fusion (BFB) cycles. Classical Hodgkin’s lymphoma (cHL) and Multiple Myeloma (MM) are two blood tumor both characterized by genomic instability. cHL is a B-Cell lymphoma comprised of mononuclear Hodgkin cells (H) and bi- to multi-nucleated Reed-Sternberg (RS) cells, both characterized by numerical (nCIN) and structural chromosomal instability (sCIN). Transition from H to RS cells is correlated with aberrant number of mitotic spindles, aberrant 3D telomere organization, increase in the number of telomere aggregates and telomere loss. Advanced shortening of telomeres leads disruption of 3D interaction of the telomere with TRF2, a member of the shelterin proteins responsible for the protection of the chromosome ends from the DNA damage repair system. MM, an incurable plasma cell disorder, is also characterized by CIN, microsatellite instability (MSI), and telomere attrition. Lamin A/C, a nuclear envelope protein and component of the nuclear matrix, is important for the assembly of the mitotic spindles and for the maintenance of the 3D telomeres architecture by binding the shelterin protein TRF2. Due to lamin A/C involvement in the maintenance of genomic stability, our goal was to investigate lamin A/C 3D spatial organization in cHL and MM, and understand whether the localized uncapping of TRF2 from telomeres leads to their detachment from the nuclear matrix component lamin A/C causing genomic instability. Western blot analysis and qRT-PCR analysis revealed that H and RS are characterized by an overall overexpression of lamin A/C when compared to the B-lymphocytes control. Three dimensional (3D) fluorescent microscopy in cHL and MM cells revealed that the regular homogeneous lamin A/C pattern identified in normal activated B-lymphocytes, was replaced by an aberrant lamin A/C 3D spatial distribution characterized by the presence of internal lamin A/C structures. Different lamin A/C patterns where observed where the internal lamin A/C sub-divided the nucleus in to two or multiple compartments, suggesting a possible involvement of lamin A/C in the multi-nucleation process. To investigate lamin A/C involvement in the multinucleation process and transition from H to RS, the downregulation of lamin A/C with siRNA was performed. Downregulation of lamin A/C affected the transition from H to RS cells, as the number of RS cells found after lamin silencing was decreased. Telomere 3D structure and nuclear organization were also affected by the deregulation of lamin A/C. H and RS cells were also characterized by unbinding of telomere-TRF2-lamin A/C when compared to the healthy control.
Lack of co-localization of telomere-TRF2-lamin A/C confirms lamin A/C involvement in genomic instability, and suggests that localized absence of TRF2 could be causal to the genome remodeling in cHL
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