PERFORMANCE AND BEHAVIOUR OF CHICKENS WITH DIFFERENT GROWING RATE REARED ACCORDING TO THE ORGANIC SYSTEM

The performance and the behaviour of three different chicken strains, reared according to the EEC-Regulation 1804/1999 organic system, were compared. The strains had very slow (Robusta maculata), slow (Kabir) and fast (Ross) growing rates, respectively. The trial was carried out on 200 chickens (male and female) per strain. Rearing lasted 81 days as required by the EEC Regulations. At slaughter age, 20 birds per group were killed. Robusta maculata and Kabir chickens showed more intense walking activity and better foraging aptitude; their antioxidant capacity was also superior. Ross chickens had a good growth rate and feed conversion index, reaching an excellent body weight, but the mortality and the culling rate were high indicating that fast-growing strains do not adapt well to organic production. Robusta maculata showed the worst productive performance although the mortality was low and Kabir birds gave intermediate results. The carcass traits were the best in Ross and the poorest in Robusta maculata. Male chickens were heavier and leaner than females

Stability of Ge-related point defects and complexes in Ge-doped SiO_2

We analyze Ge-related defects in Ge-doped SiO_2 using first-principles density functional techniques. Ge is incorporated at the level of ~ 1 mol % and above. The growth conditions of Ge:SiO_2 naturally set up oxygen deficiency, with vacancy concentration increasing by a factor 10^5 over undoped SiO_2, and O vacancies binding strongly to Ge impurities. All the centers considered exhibit potentially EPR-active states, candidates for the identification of the Ge(n) centers. Substitutional Ge produces an apparent gap shrinking via its extrinsic levels.Comment: RevTeX 4 pages, 2 ps figure

Relation between phase and dwell times for quantum tunneling of a relativistically propagating particle

The general and explicit relation between the phase time and the dwell time for quantum tunneling of a relativistically propagating particle is investigated and quantified. In analogy with previously obtained non-relativistic results, it is shown that the group delay can be described in terms of the dwell time and a self-interference delay. Lessons concerning the phenomenology of the relativistic tunneling are drawn

Potenzialita' e limiti degli archivi letterari digitali. Il caso del Walt Whitman Archive.

Potenzialita' e limiti degli archivi letterari digitali. Il caso del Walt Whitman Archive. La mia breve comunicazione si colloca all'interno del nascente ambito interdisciplinare delle cosiddette Digital Humanities. \uc9 solo da qualche decennio che gli accademici si stanno dedicando a studiare le nuove forme di produzione, disseminazione, fruizione e conservazione dei testi letterari offerte dai nuovi media digitali, e la conseguente riconfigurazione (in senso non solo metodologico, ma anche teorico e critico) delle discipline umanistiche stesse. Dopo aver delineato in via generale gli interessi di tale innovativo campo di studi, discuter\uf2 il concetto di archivio letterario digitale. Pur essendosi il termine \u201carchivio\u201d ormai consolidato nel linguaggio delle Digital Humanities, illustri studiosi delle questioni riguardanti la preservazione e diffusione dei testi letterari tramite media digitali, come Susan Hockey e Matthew G. Kirschenbaum , hanno infatti messo in discussione l'uso di tale termine per indicare le nuove risorse digitali che permettono di consultare anche integralmente documenti bibliografici online, in formato elettronico. Si dovrebbe piuttosto, a loro parere, parlare di \u201crepositories\u201d (\u201cdepositi\u201d) o \u201ccollections\u201d (\u201ccollezioni\u201d), trattandosi di modalit\ue0 di conservazione ben diverse da quelle dell\u2019archivistica cartacea classica, peraltro molto meno esposta alle continue trasformazioni e ai rischi di obsolescenza connessi alla continua evoluzione tecnologica dei software e hardware. Passer\uf2 a questo punto ad indagare la natura, le maggiori potenzialit\ue0 e allo stesso tempo i maggiori limiti di tali collezioni letterarie digitali, a mio parere definibili, in senso lato, come spazi culturali dinamici di natura non solo testuale ma anche contestuale (e dunque intratestuale, cotestuale, intertestuale, paratestuale, extratestuale) continuamente modificabili e ampliabili e altamente accessibili in senso non solo materiale, ma soprattutto relazionale (mi riferisco ad esempio alla possibilit\ue0 di entrare in contatto con altre risorse di sapere digitalizzato tramite semplici link) nonch\ue8 extra-accademico. Mi soffermer\uf2 in questo senso, in qualit\ue0 di studiosa e traduttrice dell'opera del poeta americano Walt Whitman, sul rivoluzionario ampliamento delle possibilit\ue0 di diffusione, approfondimento nonch\ue9 ricerca e didattica dell'opera whitmaniana negli Stati Uniti e nel mondo, offerto dal Walt Whitman Archive, integralmente e gratuitamente consultabile online ormai da oltre dieci anni, in versioni via via aggiornate, all'indirizzo www.whitmanarchive.org. (Approfitterei, se fosse possibile, di un collegamento internet in sala per illustrare a grandi linee la storia, la struttura e i contenuti di quello che tra i cosiddetti \u201carchivi\u201d letterari digitali, pu\uf2 essere considerato uno tra i pi\uf9 famosi, oltre che completi e validi, esemplari, alla stregua del Rossetti Archive, del Blake Archive, del Canterbury Tales Project e dei Dickinson Electronic Archives). Come scrivono, nella sezione dedicata alla storia del Whitman Archive, i suoi fondatori, Prof. Ed Folsom (University of Iowa) e Prof. Kenneth M. Price (University of Nebraska-Lincoln), la scelta di utilizzare il formato digitale per la pubblicazione dell'opera whitmaniana \ue8 risultata assai felice, dal momento che si tratta di un'opera vastissima e, soprattutto, fortemente caratterizzata da continue revisioni: esistono infatti ben sei edizioni successive, tutte molto diverse tra loro, delle Foglie d'erba , che andrebbero studiate proprio nelle loro singole versioni piuttosto che come un\u2019opera unitaria. Non solo l'archivio in questione, a differenza di qualsiasi altra risorsa a stampa contenente l'opera whitmaniana, presenta tutte le sei edizioni corredate di introduzioni critiche ed elenchi bibliografici delle loro traduzioni in altre lingue, nonch\ue9 delle recensioni, saggi, e studi ad esse dedicati a livello nazionale e internazionale dalla data della loro pubblicazione ad oggi, ma offre anche una biografia, una concordanza, la possibilit\ue0 di accedere alle foto dei diversi manoscritti che in America sono dislocati in pi\uf9 di sessanta biblioteche diverse e di consultare gli scritti di prosa, la corrispondenza e le fotografie del poeta, e persino alcuni inediti. Vi \ue8 infine anche una sezione straniera contenente traduzioni delle Leaves in varie lingue, tra cui lo spagnolo, il russo, il tedesco. L'obiettivo del sito \ue8 infatti quello di riuscire a pubblicare integralmente, col passare del tempo, tutta la produzione edita o inedita di Whitman e le traduzioni straniere delle Leaves fuori copyright o nate appositamente per la pubblicazione nel sito, nonch\ue9 di offrire il quadro aggiornato del sempre nuovo materiale critico, storico e comparatistico pi\uf9 o meno direttamente connesso all'opera whitmaniana. Si tratta insomma di uno strumento di approfondimento e di ricerca assai specifico, ma allo stesso tempo intertestuale, plurilinguistico e transculturale, che offre la possibilit\ue0 di consultare, leggere e studiare i testi whitmaniani a pi\uf9 livelli, di confrontarli con altri testi e di studiare la loro ricezione e diffusione tramite la traduzione in altre lingue. Del resto, come scrive Martha Nell Smith, \u201cUnderstanding the poetic and principles of electronic scholarly editing means understanding that the primary goal of this activity is not to dictate what can be seen but rather to open up ways of seeing\u201d . Nel caso dell'opera di Whitman, la scelta dell'archivio digitale si \ue8 mostrata finora assai fruttuosa. Certo \ue8 che anche il Whitman Archive, pur aderendo a standard internazionali, potrebbe andare incontro ad alcuni rischi dal punto di vista non solo di un invecchiamento tecnologico, ma anche di una sorta di ipertrofia contenutistica dovuta alla possibilit\ue0 di aggiungere in continuazione nuovi materiali e segnalare collegamenti utili. Ci\uf2 potrebbe minarne non solo la qualit\ue0 scientifica, ma anche la chiarezza e semplicit\ue0 di utilizzo che finora lo hanno contraddistinto. Il caso del Whitman Archive \ue8 dunque un buon punto di partenza per riconoscere le potenzialit\ue0 di applicazione del digitale alle pratiche accademiche e, pi\uf9 in generale, culturali e letterarie, tradizionali, ma anche per sollevare importanti interrogativi circa la natura, le finalit\ue0 e i limiti di tali pratiche, che necessitano di venir indagate in modo sempre pi\uf9 approfondito e specifico

Urban Services and Climate Change Adaptation. Applying a Novel Methodological Framework

The paper deals with adaptation to climate change in urban environments through the adoption of Soft-resilience strategies. It takes the moves from the distinction between hard and soft approach for built environment adaptation – and their complementarity – up to suggest that soft solutions would represent an effective option to respond to unprecedented emerging risks. The contribution opens with an interpretation of the still ongoing global crisis as an important lesson and introduces the hypothesis that urban services play a fundamental role as a support to human systems in coping with climate change impacts. This led to the research hypothesis for which these services would constitute by themselves a soft, low-regret and co-benefit adaptation strategy. The meta-design of new procedural models for the delivery and the operation of urban services aimed at improving climate resilience (and, thus, definable as Adaptation services), based on the optimal exploitation of re-organizational and information management strategies, represents an innovative research line. The paper goes through the development of a dedicated method to be applied for mapping potential transitions in specific territorial contexts. It provides for the in-depth analysis of four main aspects characterizing Adaptation services management: i) the organizational structure of the subjects involved; ii) the service supply chain; iii) information management processes; iv) multi-scale and multi-level interactions between different services. Some representative examples of the implementation of the method in Italian and European real cases are presented: urban greenery services in Milano, urban mobility in San Donato Milanese, Civil Protection in Novate Milanese, climate and consulting services in Hamburg. The convergence of insights collected from different sources (information triangulation), by means of systematic literature review, analysis of policy documents and a continuous dialogue with key stakeholders through semi-structured interviews and cooperation agreements, shall ensure the consistency of the research findings

Formation and stability of a two-dimensional nickel silicide on Ni (111) an Auger, LEED, STM, and high-resolution photoemission Study

Using low energy electron diffraction (LEED), Auger electron spectroscopy (AES), scanning tunnelling microscopy (STM) and high resolution photo-electron spectroscopy (HR-PES) techniques we have studied the annealing effect of one silicon monolayer deposited at room temperature onto a Ni (111) substrate. The variations of the Si surface concentration, recorded by AES at 300{\deg}C and 400{\deg}C, show at the beginning a rapid Si decreasing followed by a slowing down up to a plateau equivalent to about 1/3 silicon monolayer. STM images and LEED patterns, both recorded at room temperature just after annealing, reveal the formation of an ordered hexagonal superstructure(rot3xrot3)R30{\deg}-type. From these observations and from a quantitative analysis of HR-PES data, recorded before and after annealing, we propose that the (rot3 x rot3)R30{\deg}superstructure corresponds to a two dimensional (2D) Ni2Si surface silicide.Comment: Journal Physical Review B (2012

The coupling constants for an electroweak model with a SU(4)PS⊗SU(4)EWSU(4)_{PS} \otimes SU(4)_{EW} unification symmetry

We introduce the sequence of spontaneous symmetry breaking of a coupling between Pati-Salam and electroweak symmetries $SU(4)_{PS} \otimes SU(4)_{EW}$ in order to establish a mathematically consistent relation among the coupling constants at grand unification energy scale. With the values of baryon minus lepton quantum numbers of known quarks and leptons, by including right-handed neutrinos, we can find the mixing angle relations at different energy levels up to the electromagnetic $U(1)_{EM}$ scale.Comment: 8 page

The accretion environment of Supergiant Fast X-ray Transients probed with XMM-Newton

Supergiant fast X-ray transients (SFXTs) are characterized by a remarkable variability in the X-ray domain, widely ascribed to the accretion from a clumpy stellar wind. In this paper we performed a systematic and homogeneous analysis of sufficiently bright X-ray flares from the SFXTs observed with XMM-Newton to probe spectral variations on timescales as short as a few hundred of seconds. Our ultimate goal is to investigate if SFXT flares and outbursts are triggered by the presence of clumps and eventually reveal whether strongly or mildly dense clumps are required. For all sources, we employ a technique developed by our group, making use of an adaptive rebinned hardness ratio to optimally select the time intervals for the spectral extraction. A total of twelve observations performed in the direction of five SFXTs are reported. We show that both strongly and mildly dense clumps can trigger these events. In the former case, the local absorption column density may increase by a factor of >>3, while in the latter case, the increase is only by a factor of 2-3 (or lower). Overall, there seems to be no obvious correlation between the dynamic ranges in the X-ray fluxes and absorption column densities in SFXTs, with an indication that lower densities are recorded at the highest fluxes. This can be explained by the presence of accretion inhibition mechanism(s). We propose a classification of the flares/outbursts from these sources to drive future observational investigations. We suggest that the difference between the classes of flares/outbursts is related to the fact that the mechanism(s) inhibiting accretion can be overcome more easily in some sources compared to others. We also investigate the possibility that different stellar wind structures, rather than clumps, could provide the means to temporarily overcome the inhibition of accretion in SFXTs.Comment: Accepted for publication on A&

Naturalness and stability of the generalized Chaplygin gas in the seesaw cosmon scenario

The seesaw mechanism is conceived on the basis that a mass scale, $\xi$, and a dimensionless scale, $s$, can be fine-tuned in order to control the dynamics of active and sterile neutrinos through cosmon-type equations of motion: the seesaw cosmon equations. This allows for sterile neutrinos to be a dark matter candidate. In this scenario, the dynamical masses and energy densities of active and sterile neutrinos can be consistently embedded into the generalized Chaplygin gas (GCG), the unified dark sector model. In addition, dark matter adiabatically coupled to dark energy allows for a natural decoupling of the (active) mass varying neutrino (MaVaN) component from the dark sector. Thus MaVaN's turn into a secondary effect. Through the scale parameters, $\xi$ and $s$, the proposed scenario allows for a convergence among three distinct frameworks: the cosmon scenario, the seesaw mechanism for mass generation and the GCG model. It is found that the equation of state of the perturbations is the very one of the GCG background cosmology so that all the results from this approach are maintained, being smoothly modified by active neutrinos. Constrained by the seesaw relations, it is shown that the mass varying mechanism is responsible for the stability against linear perturbations and is indirectly related to the late time cosmological acceleration.Comment: 24 pages, 6 figure

Isolation and characterization of five microsatellite loci in Dolichopoda cave crickets (Orthoptera Rhaphidophoridae)

Five microsatellite loci are described for the cave cricket genus Dolichopoda. Preliminary data on allelic variation of these loci are presented for one population of D. schiavazzii and one population of D. laetitiae to test their usefulness in fine-scale studies of the genetic aspect of cave colonization. Cross-species amplifications were carried out in four other Dolichopoda species and in two species belonging to another cave cricket genus (Troglo-philus) to test the potential use of these microsatellite markers in studies of both congeneric species and species belonging to the same family