978 research outputs found
Breaking the silence of the 500-year-old smiling garden of everlasting flowers: The En Tibi book herbarium
We reveal the enigmatic origin of one of the earliest surviving botanical collections. The 16th-century Italian En Tibi herbarium is a large, luxurious book with c. 500 dried plants, made in the Renaissance scholarly circles that developed botany as a distinct discipline. Its Latin inscription, translated as “Here for you a smiling garden of everlasting flowers”, suggests that this herbarium was a gift for a patron of the emerging botanical science. We follow an integrative approach that includes a botanical similarity estimation of the En Tibi with contemporary herbaria (Aldrovandi, Cesalpino, “Cibo”, Merini, Estense) and analysis of the book’s watermark, paper, binding, handwriting, Latin inscription and the morphology and DNA of hairs mounted under specimens. Rejecting the previous origin hypothesis (Ferrara, 1542–1544), we show that the En Tibi was made in Bologna around 1558. We attribute the En Tibi herbarium to Francesco Petrollini, a neglected 16th-century botanist, to whom also belongs, as clarified herein, the controversial “Erbario Cibo” kept in Rome. The En Tibi was probably a work on commission for Petrollini, who provided the plant material for the book. Other people were apparently involved in the compilation and offering of this precious gift to a yet unknown person, possibly the Habsburg Emperor Ferdinand I. The En Tibi herbarium is a Renaissance masterpiece of art and science, representing the quest for truth in herbal medicine and botany. Our multidisciplinary approach can serve as a guideline for deciphering other anonymous herbaria, kept safely “hidden” in treasure rooms of universities, libraries and museums
Existential behavioral therapy for informal caregivers of palliative patients: Barriers and promoters of support utilization
AbstractObjective:Several interventions have been developed during recent years to support informal caregivers of palliative patients. However, these trials reported low enrollment rates. Employing a newly developed group intervention, existential behavioral therapy (EBT), one study reported that only 13.6% of approached informal caregivers participated. The purpose of our present study was to identify the reasons for this low enrollment rate in order to improve future support designs.Method:All participants in the EBT trial (intervention vs. standard-care control group) as well as those who declined participation during a 4-month recruitment period were studied prospectively over 12 months. Andersen's behavioral model of healthcare service use was employed to identify group differences between acceptors and decliners: predisposing (age, gender, education, family status, relationship), enabling (social support, distance to hospital, caring vs. bereaved), and need factors (psychological distress, quality of life) were evaluated in a binary-logistic model.Results:Some 94 decliners were compared to 160 EBT participants (n = 81 intervention, n = 79 control). Caregivers who took part were significantly more distressed and suffered from a lower quality of life compared to decliners. Not only these need factors but also predisposing (age <55 years) and enabling (use of social/professional support, familiarity with caregiving institution) factors were associated with EBT utilization. At the 12-month follow-up, EBT intervention participants reported greater quality of life improvements than decliners or controls (p = 0.05). While all groups had mean anxiety scores below the cutoff at 12-month follow-up, decliners showed better improvement in anxiety compared to EBT participants (intervention p = 0.04, controls p = 0.03).Significance of results:On average, decliners are less burdened: they may be more resilient, may have better coping strategies, or already have a sufficient support network in place. Screening caregivers with regard to their experienced quality of life and targeting those in need, especially younger caregivers with low levels of quality of life, may help to allocate resources more appropriately.</jats:sec
Liquid-Sensing Probe and Methods for Using the Same
A sensor assembly includes a main body, a sensor, and a filler. The main body includes an outer surface having a continuously-variable radius of curvature in at least one portion. A sensor in thermal communication with a region of that surface having relatively low radius of curvature is disposed in the assembly recessed from the outer surface. Liquid droplets adhered to the outer surface in this region tend to migrate to a distant location having a higher radius of curvature. The main body has low thermal conductivity. The filler has a relatively higher thermal conductivity and, in embodiments, fills an opening in the outer surface of the main body, providing a thermally-conductive pathway between the sensor and the surrounding environment via the opening. A probe having a plurality of such sensors, and methods of detecting the presence of liquid and phase transitions in a predetermined space are also disclosed
Self-induced ultrafast electron-hole plasma temperature oscillations in nanowire lasers
Nanowire lasers can be monolithically and site-selectively integrated onto
silicon photonic circuits. To assess their full potential for ultrafast
opto-electronic devices, a detailed understanding of their lasing dynamics is
crucial. However, the roles played by their resonator geometry and the
microscopic processes that mediate energy exchange between the photonic,
electronic, and phononic subsystems are largely unexplored. Here, we study the
dynamics of GaAs-AlGaAs core-shell nanowire lasers at cryogenic temperatures
using a combined experimental and theoretical approach. Our results indicate
that these NW lasers exhibit sustained intensity oscillations with frequencies
ranging from 160 GHz to 260 GHz. As the underlying physical mechanism, we
identified self-induced electron-hole plasma temperature oscillations resulting
from a dynamic competition between photoinduced carrier heating and cooling via
phonon scattering. These dynamics are intimately linked to the strong
interaction between the lasing mode and the gain material, which arises from
the wavelength-scale dimensions of these lasers. We anticipate that our results
could lead to new approaches for ultrafast intensity and phase modulation of
chip-integrated nanoscale semiconductor lasers.Comment: Revised manuscrip
Towards Loop Quantum Supergravity (LQSG) II. p-Form Sector
In our companion paper, we focussed on the quantisation of the
Rarita-Schwinger sector of Supergravity theories in various dimensions by using
an extension of Loop Quantum Gravity to all spacetime dimensions. In this
paper, we extend this analysis by considering the quantisation of additional
bosonic fields necessary to obtain a complete SUSY multiplet next to graviton
and gravitino in various dimensions. As a generic example, we study concretely
the quantisation of the 3-index photon of 11d SUGRA, but our methods easily
extend to more general p-form fields. Due to the presence of a Chern-Simons
term for the 3-index photon, which is due to local SUSY, the theory is
self-interacting and its quantisation far from straightforward. Nevertheless,
we show that a reduced phase space quantisation with respect to the 3-index
photon Gauss constraint is possible. Specifically, the Weyl algebra of
observables, which deviates from the usual CCR Weyl algebras by an interesting
twist contribution proportional to the level of the Chern-Simons theory, admits
a background independent state of the Narnhofer-Thirring type.Comment: 12 pages. v2: Journal version. Minor clarifications and correction
Coherent X-ray Scattering from Manganite Charge and Orbital Domains
We report coherent x-ray scattering studies of charge and orbital domains in
manganite systems. The experiments were carried out on LaMnO_3 and
Pr_{0.6}Ca_{0.4}MnO_3, with the incident photon energy tuned near the Mn K
edge. At room temperature, the orbital speckle pattern of LaMnO_3 was observed
to be constant over a timescale of at least minutes, which is indicative of
static orbital domains on this timescale. For Pr_{0.6}Ca_{0.4}MnO_3, both
charge and orbital speckle patterns were observed. The observation of the
latter rules out the presence of fast orbital fluctuations, while long time
series data-- on the order of several minutes-- were suggestive of slow dynamic
behavior. In contrast, the charge order speckle patterns were static.Comment: 6 pages, 4 figure
Interfaces in Diblocks: A Study of Miktoarm Star Copolymers
We study AB miktoarm star block copolymers in the strong segregation
limit, focussing on the role that the AB interface plays in determining the
phase behavior. We develop an extension of the kinked-path approach which
allows us to explore the energetic dependence on interfacial shape. We consider
a one-parameter family of interfaces to study the columnar to lamellar
transition in asymmetric stars. We compare with recent experimental results. We
discuss the stability of the A15 lattice of sphere-like micelles in the context
of interfacial energy minimization. We corroborate our theory by implementing a
numerically exact self-consistent field theory to probe the phase diagram and
the shape of the AB interface.Comment: 12 pages, 11 included figure
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