196,519 research outputs found
Gli oggetti in metallo, osso lavorato e pasta vitrea
No full textNel contributo si presentano i risultati dell'analisi tipologica dei reperti in metallo, osso lavorato e pasta vitrea rinvenuti nel corso di indagini archeologiche all'interno della Cisterna 1 della Torre Mozza del Castello Carlo V di Lecc
De Novo Reconstitution of Skeletal Muscle Voltage-Induced Calcium Release
No full textDepolarization of vertebrate skeletal muscle causes intracellular calcium
release, an event depending on specialized junctions between the plasma
membrane (PM) and sarcoplasmic reticulum (SR). It is known that depolarization is ‘‘sensed’’ by a voltage-gated calcium channel located in the PM
and containing CaV1.1 as its principal subunit, that calcium is released
from the SR via RyR1, and that this does not require external Ca2þ entry.
Thus, it is thought that activation of RyR1 is driven by depolarizationinduced conformational changes in CaV1.1 which are mechanically transmitted to RyR1, either directly or via intervening proteins. Based on muscle
gene knockouts, at least two additional proteins are required for this conformational coupling, but knockouts cannot reveal whether yet-to-be identified
proteins, or sets of proteins with overlapping functions, are also critical.
Thus, we used reconstitution in tsA201 cells to identify a minimal set of proteins required for conformational coupling. We found that expression of junctophilin2 was effective at promoting ER-PM junctions, and that CaV1.1 and
RyR1 both targeted to these junctions in the presence of the CaV1.1 auxiliary
subunit b1a. Moreover, tsA201 cells expressing these four proteins, and the
adapter protein Stac3, produced depolarization-triggered Ca2þ transients
which were independent of extracellular Ca2þ entry and which increased in
amplitude as a saturating function of voltage, as expected for conformational
coupling. Additionally, freeze-fracture electron microscopy indicated that
CaV1.1 and RyR1 were physically linked in these cells, thus establishing
that the five expressed proteins are sufficient for conformational coupling.
The ability to reconstitute conformational coupling with a minimal set of proteins may provide a system for obtaining high resolutions structures of
CaV1.1 and RyR1 as part of a functioning complex, which will be necessary
for understanding the molecular mechanism of depolarization-evoked calcium release in skeletal muscle
De novo reconstitution reveals the proteins required for skeletal muscle voltage-induced Ca <sup>2+</sup> release
No full textSignificance
Excitation–contraction coupling (ECC) in vertebrate skeletal muscle depends upon specialized junctions at which Ca
V
1.1, a voltage-gated channel in the plasma membrane, interacts with RyR1, a calcium release channel in the sarcoplasmic reticulum. Because calcium flux via Ca
V
1.1 is unnecessary for ECC, Ca
V
1.1 is thought to “conformationally couple” to RyR1. Studies of muscle cells with gene knockouts have shown that additional, junctional proteins are also necessary, but are unable to reveal whether or not these complete the set of required proteins. Here, we show that conformational coupling can be conferred upon tsA201 cells by expressing five junctional proteins (Ca
V
1.1, RyR1, β1a, Stac3, and junctophilin2), thus establishing a minimum set of proteins supporting Ca
V
1.1–RyR1 conformational coupling in skeletal muscle.
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Extraforaminal disk herniation treatment with surgical exploration by unilateral intertransversarii microsurgical approach
No full textIn this study we evaluated the role of a unilateral intertransversarii microsurgical approach for the treatment of extraforaminal lumbar disk herniations (ELDHs), with short-, medium-, and long-term follow-up
Phylogenetic reappraisal and epitypification of Laccaria macrocystidiata (Hydnangiaceae, Basidiomycota)
No full textLaccaria macrocystidiata, a marasmioid species, originally described as Laccaria affinis f. macrocystidiata from Central Italy, was synonymised with the North American taxon Laccaria laccata var. pallidifolia, but only on a morphological basis. In this paper, the independent position of L. macrocystidiata from L. laccata var. pallidifolia and other species of Laccaria is pointed out on the basis of ITS-LSU phylogenetic analyses. According to our results, Laccaria macrocystidiata var. longispinosa is considered a synonym of Laccaria macrocystidiata. Laccaria macrocystidiata holotype consists of only one basidioma in poor condition; thus, a new epitype from an Italian collection was designated
Dispositivi di drenaggio forzato per lo scavo di una grande galleria
No full textVengono illustrati gli studi svolti e le tecnologie impiegate per l'esecuzione di una tratta della galleria ferroviaria dei Peloritani, m cui le metamorfiti fortemente tettonizzate, sono mteressate da una falda con carico di 5 bar. Per superare le difficolta' all'avanzamento sono state studtate vane soluzioni di consolidamento dei terreni, di congelamento, di abbassamento di falda dall'esterno. E' stato alfine adottato
uno schema dt presostegno con infilaggi, completato con un dispositivo di drenaggi ad aureola, nei quali si e' applicata una depressione di 0.5 bar (vacuum technique). Per verificarel'efficacia di tale soluzione, in funzione della lunghezza dei drenaggi e dell'applicazione della depressione e' stata condotta una sene di analisi di filtrazione ad elementi finiti in regime assialsimmetrico rispetto all'asse longitudinale della galleria. Si e' considerata la filtrazione m regime siapermanente che transitorio, individuando anche gli effetti sulla stabilita del fronte derivanti dalle possibili perdite di depressione net drenaggi. Le analisi elasto-plastiche condotte a questo scopo hanno permesso di ricavare la possibile estensione della zona plastica a tergo del fronte in assenza dei drenaggi. Essa e' risultata invece praticamente assente in presenza del sistema aspirante attivato.
L'appl!cazione del dispositivo ha consentito, pur in condizioni cccezionalmente difficili, di eseguire in sicurezza oltre 800 m di galleria con un avanzamento medio di 20 m/mese
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Influenza di alcune variabili operative (permeabilità dei film, atmosfera modificata non convenzionale) sulle proprietà qualitative di melone minimamente lavorato (IV gamma)
No full textInfluenza di alcune variabili operative (permeabilità dei film, atmosfera modificata non convenzionale) sulle proprietà qualitative di melone minimamente lavorato (IV gamma
Modeling of the mechanical behavior of stainless reinforcing steel
No full textStainless reinforcement is desirably corrosion-resistant, making structures safe, reliable and durable. In this paper, the constitutive model of stainless steel rebar including nonlinear buckling was presented. Consisting of four hardening rules such as kinematic rule, isotropic rule, saturation rule and memory rule, the Monti-Nuti Model could adopt the Menegotto-Pinto backbone curve to simulate accurately the monotonie and cyclic behaviour of the stainless reinforcing steel including buckling. Comparisons between the numerical results and experimental results were shown to demonstrate the validity
Risposta vegeto-produttiva di viti Sangiovese in terreno lavorato ed inerbito
No full textNel corso del triennio 2004-2006, è stato confrontato, in un vigneto in area collinare- argillosa del bolognese, il comportamento vegeto-produttivo di viti di Sangiovese sottoposte a inerbimento (Festuca pseudovina) e a lavorazione interfilare. Nel complesso le viti allevate su terreno inerbito hanno presentato, rispetto a quelle su terreno lavorato, una minore crescita dei germogli e una produzione inferiore associata a un maggior contenuto in solidi solubili e antociani totali delle uve. Nel 2006, il contenuto idrico del suolo sotto la fila è risultato più basso nella tesi inerbita e le viti hanno evidenziato un potenziale idrico inferiore rispetto alla tesi con lavorazione.[...
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