2,243 research outputs found
Consejos de Catalina de Siena a las mujeres religiosas
This essay begins with the paradox that Catherine of Siena, perhaps the most famous uncloistered religious woman in the Middle Ages, became after her death an authority and model for cloistered monasticism for women during the Dominican reform movement. But the dissonance in the idea of Catherine as a model for cloistered religious women is heightened by false assumptions or oversimplifications of Catherine’s religious status, and of what it meant for Catherine to be a model for this or that form of religious life. This essay surveys Catherine’s letters to religious women, including letters to penitents or mantellate and letters to abbesses and nuns in monasteries. While Catherine’s letters to penitents and other women living in the world focus on the challenges of living without a formal religious rule, her letters to nuns focus on the importance of their maintaining claustration, following their rule, and on the dangers of wealth—a recognition of the generally higher social and economic standing of monastic women. Catherine seems also to identify certain kinds of prayer with monastic life. It is important to remember that Catherine herself founded a monastery, and while it remains unclear what precisely her intentions were for this community, it is another sign of Catherine’s interest in and commitment to cloistered religiosity. The essay concludes by arguing for a more nuanced understanding of what it might have meant for Catherine to be a model for specific forms of religious life.Este ensayo comienza con la paradoja de que Catalina de Siena, quizás la religiosa no enclaustrada más famosa de la Edad Media, se convirtió después de su muerte en una autoridad y modelo para el monaquismo enclaus-trado para mujeres durante el movimiento de reforma dominicano. Pero la disonancia en la idea de Catalina como modelo para las religiosas enclaustradas se ve acentuada por las suposiciones falsas o las simplificaciones excesivas del estatus religioso de Catalina, y de lo que significaba para Catalina ser un modelo para una u otra forma de vida religiosa. Este ensayo examina las cartas de Catalina a mujeres religiosas, incluyendo cartas a penitentes o manteladas y cartas a abadesas y monjas en monasterios. Mientras que las cartas de Catalina a las penitentes y otras mujeres que viven en el mundo se enfocan en los de-safíos de vivir sin regla religiosa formal, sus cartas a las monjas se enfocan en la importancia de mantener la clausura, seguir su regla, y en los peligros de la riqueza—un reconocimiento de la posición social y económica generalmente más alta de las mujeres monásticas. Catalina también parece identificar ciertos tipos de oración con la vida monástica. Es importante recordar que la propia Catalina fundó un monasterio, y aunque no está claro cuáles eran sus intenciones precisas para esta comunidad, es otra señal de su interés y compromiso con la religiosidad de clausura. El ensayo concluye abogando por una comprensión más matizada de lo que podría haber significado para Catalina ser un modelo para formas específicas de vida religiosa.Humanidade
Maximum turnaround radius in gravity
The accelerating behavior of cosmic fluid opposes to the gravitational
attraction, at present epoch, whereas standard gravity is dominant at small
scales. As a consequence, there exists a \emph{point} where the effects are
counterbalanced, dubbed \emph{turnaround radius}, . By
construction, it provides a bound on maximum structure sizes of the observed
universe. Once an upper bound on is provided, i.e.
, one can check whether cosmological models guarantee
structure formation. Here, we focus on gravity, without imposing \emph{a
priori} the form of . We thus provide an analytic expression for the
turnaround radius in the framework of models. To figure this out, we
compute the turnaround radius in two distinct cases: 1) under the hypothesis of
static and spherically symmetric space-time, and 2) by using the cosmological
perturbation theory. We thus find a criterion to enable large scale structures
to be stable in models, circumscribing the class of theories as
suitable alternative to dark energy. In particular, we get that for constant
curvature, the viability condition becomes , with and
respectively the observed cosmological constant and the Ricci
curvature. This prescription rules out models which do not pass the
aforementioned limit.Comment: 8 pages, 1 figur
On the mechanics of caldera resurgence of Ischia Island (southern Italy)
A model of caldera resurgence was applied to the Island of Ischia to explain uplift,
volcanic activity and tectonics on Mount Epomeo, as well as historical seismicity and slow
ground movements recorded for the past 2000 years. A two-dimensional mechanical model
was utilized for the crust, which was considered to be an elastic plate overlying a laccolith.
Geometric dimensions and mechanical parameters were constrained using geological,
geophysical and geochemical data.
We propose that a laccolith, with a diameter L of c. 10 km, and a depth of up to 1 km in the
centre of the island, triggered the caldera resurgence after the Mount Epomeo Green Tuff
eruption forming the caldera (55 000 a BP). A bending phase and a punched laccolith phase are
thought to have caused the observed deformations in the caldera. These processes control the
tectonics at the boundary of the Mount Epomeo resurgent structure, volcanic activity and
dynamics of the island
Folate-based single cell screening using surface enhanced Raman microimaging
Recent progress in nanotechnology and its application to biomedical settings have generated great advantages in dealing with early cancer diagnosis. The identification of the specific properties of cancer cells, such as the expression of particular plasma membrane molecular receptors, has become crucial in revealing the presence and in assessing the stage of development of the disease. Here we report a single cell screening approach based on Surface Enhanced Raman Scattering (SERS) microimaging. We fabricated a SERS-labelled nanovector based on the biofunctionalization of gold nanoparticles with folic acid. After treating the cells with the nanovector, we were able to distinguish three different cell populations from different cell lines (cancer HeLa and PC-3, and normal HaCaT lines), suitably chosen for their different expressions of folate binding proteins. The nanovector, indeed, binds much more efficiently on cancer cell lines than on normal ones, resulting in a higher SERS signal measured on cancer cells. These results pave the way for applications in single cell diagnostics and, potentially, in theranostic
Resurgence and flank failure of Mt. Epomeo, Ischia Island (Southern Italy)
Risorgenza e collasso laterale del Monte Epomeo, Isola
d’Ischia
Il Monte Epomeo (787 m a.s.l.), ubicato nel settore centrale dell’isola
d’Ischia, mostra lo smantellamento del settore meridionale, depositi
di debris e franamenti diffusi che testimoniano la natura instabile
del monte. A seguito dell’eruzione ignimbritica del Tufo Verde
dell’Epomeo (55.000 anni), che genera una struttura calderica (10x7
km2), inizia la risorgenza della caldera fino alla formazione del Monte
Epomeo. Il sollevamento, generato dall’intrusione di un laccolite fino
a circa 1 km di profondità, avrebbe determinato una forte instabilità
gravitativa del blocco risorgente e prodotto uno o più collassi laterali.
Questi hanno lasciato una struttura a ferro di cavallo, tipica di
processi da “avalancing”, aperta verso sud, e depositi con topografia
“hummocky” estesi a sud dell’Epomeo e rilevati recentemente da esplorazioni
sul fondo marino. Il processo che ha generato il collasso
e la formazione di un avalanche caldera è stato esaminato attraverso
l’analisi della dinamica e dei caratteri geologici, geomorfologici e
strutturali dell’area. Attualmente l’isola è caratterizzata da una fase di
stasi della risorgenza testimoniata da una condizione di moderata stabilità
dei versanti dell’Epomeo. Quanto osservato indicherebbe una
bassa dinamica endogena nell’isola
Sea level changes, ground deformations, human settlements in the bay of Naples
Ground deformations in active volcanoes are considered precursors of eruptions according to the most tested models; therefore monitoring networks of ground deformations are installed on inhabited dangerous volcanoes. Direct measurements of such deformations are carried out since 1861 when Luigi Palmieri monitored the eruption at Mt. Vesuvius with levelings along the shoreline near the town of Torre del Greco.
Relative sea level changes were measured at Serapeo in Pozzuoli in the middle of 19th century to record soil uplifts which are locally known as bradyseism. To enlarge the time series of data on these phenomena it is necessary to utilize historical and prehistorical informations on the location of shore-line of human settlements.
As regards the regions of active volcanoes as the Neapolitan one three processes contribute to sea level changes as eustatism, regional tectonics and local intrusive and effusive phenomena. Therefore at the same time the relative sea level should be different at far-away places only few kilometres according to the volcanic activity. In fact eustatic and tectonic processes contribute to sea level changes with very lesser rates than volcanic activity.
The Neapolitan region for its geological history is an excellent laboratory for testing the validation of new paradigms for some natural phenomena
Naked Singularities as Particle Accelerators II
We generalize here our earlier results on particle acceleration by naked
singularities. We showed recently[1] that the naked singularities that form due
to gravitational collapse of massive stars provide a suitable environment where
particles could get accelerated and collide at arbitrarily high center of mass
energies. However, we focussed there only on the spherically symmetric
gravitational collapse models, which were also assumed to be self-similar. In
this paper, we broaden and generalize the result to all gravitational collapse
models leading to the formation of a naked singularity as final state of
collapse, evolving from a regular initial data, without making any prior
restrictive assumptions about the spacetime symmetries such as above. We show
that when the particles interact and collide near the Cauchy horizon, the
energy of collision in the center of mass frame will be arbitrarily high, thus
offering a window to the Planck scale physics. We also consider the issue of
various possible physical mechanisms of generation of such very high energy
particles from the vicinity of naked singularity. We then construct a model of
gravitational collapse to a timelike naked singularity to demonstrate the
working of these ideas, where the pressure is allowed to be negative but the
energy conditions are respected. We show that a finite amount of mass-energy
density has to be necessarily radiated away from the vicinity of the naked
singularity as the collapse evolves. Therefore the nature of naked
singularities, both at classical and quantum level could play an important role
in the process of particle acceleration, explaining the occurrence of highly
energetic outgoing particles in the vicinity of Cauchy horizon that participate
in extreme high energy collisions.Comment: 13 pages, 5 figures, Accepted for publication in Phys. Rev. D,
Reference and Acknowledgments adde
Constant-depth circuits for Uniformly Controlled Gates and Boolean functions with application to quantum memory circuits
We explore the power of the unbounded Fan-Out gate and the Global Tunable
gates generated by Ising-type Hamiltonians in constructing constant-depth
quantum circuits, with particular attention to quantum memory devices. We
propose two types of constant-depth constructions for implementing Uniformly
Controlled Gates. These gates include the Fan-In gates defined by
for
and , where is a Boolean function. The first of our
constructions is based on computing the one-hot encoding of the control
register , while the second is based on Boolean analysis and
exploits different representations of such as its Fourier expansion. Via
these constructions, we obtain constant-depth circuits for the quantum
counterparts of read-only and read-write memory devices -- Quantum Random
Access Memory (QRAM) and Quantum Random Access Gate (QRAG) -- of memory size
. The implementation based on one-hot encoding requires either
ancillae and Fan-Out gates or
ancillae and Global Tunable gates. On the other hand, the
implementation based on Boolean analysis requires only Global Tunable gates
at the expense of ancillae.Comment: 50 pages, 10 figures. Comments are welcom
Quantum algorithm for stochastic optimal stopping problems with applications in finance
The famous least squares Monte Carlo (LSM) algorithm combines linear least
square regression with Monte Carlo simulation to approximately solve problems
in stochastic optimal stopping theory. In this work, we propose a quantum LSM
based on quantum access to a stochastic process, on quantum circuits for
computing the optimal stopping times, and on quantum techniques for Monte
Carlo. For this algorithm, we elucidate the intricate interplay of function
approximation and quantum algorithms for Monte Carlo. Our algorithm achieves a
nearly quadratic speedup in the runtime compared to the LSM algorithm under
some mild assumptions. Specifically, our quantum algorithm can be applied to
American option pricing and we analyze a case study for the common situation of
Brownian motion and geometric Brownian motion processes.Comment: 45 pages; v2: title slightly changed, typos fixed, references adde
TRPM6 is essential for magnesium uptake and epithelial cell function in the colon
Intestinal magnesium (Mg) uptake is essential for systemic Mg homeostasis. Colon cells express the two highly homologous transient receptor potential melastatin type (TRPM) 6 and 7 Mg2+ channels, but their precise function and the consequences of their mutual interaction are not clear. To explore the functional role of TRPM6 and TRPM7 in the colon, we used human colon cell lines that innately express both channels and analyzed the functional consequences of genetic knocking-down, by RNA interference, or pharmacological inhibition, by NS8593, of either channel. TRPM7 silencing caused an increase in Mg2+ influx, and correspondingly enhanced cell proliferation and migration, while downregulation of TRPM6 did not affect significantly either Mg2+ influx or cell proliferation. Exposure to the specific TRPM6/7 inhibitor NS8593 reduced Mg2+ influx, and consequently cell proliferation and migration, but Mg supplementation rescued the inhibition. We propose a model whereby in colon cells the functional Mg2+ channel at the plasma membrane may consist of both TRPM7 homomers and TRPM6/7 heteromers. A different expression ratio between the two proteins may result in different functional properties. Altogether, our findings confirm that TRPM6 cannot be replaced by TRPM7, and that TRPM6/7 complexes and TRPM6/7-mediated Mg2+ influx are indispensable in human epithelial colon cells
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