1,810 research outputs found
Ocular-based automatic summarization of documents: is re-reading informative about the importance of a sentence?
Automatic document summarization (ADS) has been introduced as a viable solution for reducing the time and the effort needed to read the ever-increasing textual content that is disseminated. However, a successful universal ADS algorithm has not yet been developed. Also, despite progress in the field, many ADS techniques do not take into account the needs of different readers, providing a summary without internal consistency and the consequent need to re-read the original document. The present study was aimed at investigating the usefulness of using eye tracking for increasing the quality of ADS. The general idea was of that of finding ocular behavioural indicators that could be easily implemented in ADS algorithms. For instance, the time spent in re-reading a sentence might reflect the relative importance of that sentence, thus providing a hint for the selection of text contributing to the summary. We have tested this hypothesis by comparing metrics based on the analysis of eye movements of 30 readers with the highlights they made afterward. Results showed that the time spent reading a sentence was not significantly related to its subjective value, thus frustrating our attempt. Results also showed that the length of a sentence is an unavoidable confounding because longer sentences have both the highest probability of containing units of text judged as important, and receive more fixations and re-fixations
Effects of abscisic acid on ethylene biosynthesis and perception in Hibiscus rosa-sinensis L. flower development
The effect of the complex relationship between ethylene and abscisic acid (ABA) on flower development and
senescence in Hibiscus rosa-sinensis L. was investigated. Ethylene biosynthetic (HrsACS and HrsACO) and receptor
(HrsETR and HrsERS) genes were isolated and their expression evaluated in three different floral tissues (petals,
style\u2013stigma plus stamens, and ovaries) of detached buds and open flowers. This was achieved through treatment
with 0.1 mM 1-aminocyclopropane-1-carboxylic acid (ACC) solution, 500 nl l21 methylcyclopropene (1-MCP), and
0.1 mM ABA solution. Treatment with ACC and 1-MCP confirmed that flower senescence in hibiscus is ethylene
dependent, and treatment with exogenous ABA suggested that ABA may play a role in this process. The 1-MCP
impeded petal in-rolling and decreased ABA content in detached open flowers after 9 h. This was preceded by an
earlier and sequential increase in ABA content in 1-MCP-treated petals and style\u2013stigma plus stamens between 1 h
and 6 h. ACC treatment markedly accelerated flower senescence and increased ethylene production after 6 h and
9 h, particularly in style\u2013stigma plus stamens. Ethylene evolution was positively correlated in these floral tissues
with the induction of the gene expression of ethylene biosynthetic and receptor genes. Finally, ABA negatively
affected the ethylene biosynthetic pathway and tissue sensitivity in all flower tissues. Transcript abundance of
HrsACS, HrsACO, HrsETR, and HrsERS was reduced by exogenous ABA treatment. This research underlines the
regulatory effect of ABA on the ethylene biosynthetic and perception machinery at a physiological and molecular
level when inhibitors or promoters of senescence are exogenously applied
Strategic lesions in the anterior thalamic radiation and apathy in early Alzheimer's disease
BACKGROUND
Behavioural disorders and psychological symptoms of Dementia (BPSD) are commonly observed in Alzheimer's disease (AD), and strongly contribute to increasing patients' disability. Using voxel-lesion-symptom mapping (VLSM), we investigated the impact of white matter lesions (WMLs) on the severity of BPSD in patients with amnestic mild cognitive impairment (a-MCI).
METHODS
Thirty-one a-MCI patients (with a conversion rate to AD of 32% at 2 year follow-up) and 26 healthy controls underwent magnetic resonance imaging (MRI) examination at 3T, including T2-weighted and fluid-attenuated-inversion-recovery images, and T1-weighted volumes. In the patient group, BPSD was assessed using the Neuropsychiatric Inventory-12. After quantitative definition of WMLs, their distribution was investigated, without an a priori anatomical hypothesis, against patients' behavioural symptoms. Unbiased regional grey matter volumetrics was also used to assess the contribution of grey matter atrophy to BPSD.
RESULTS
Apathy, irritability, depression/dysphoria, anxiety and agitation were shown to be the most common symptoms in the patient sample. Despite a more widespread anatomical distribution, a-MCI patients did not differ from controls in WML volumes. VLSM revealed a strict association between the presence of lesions in the anterior thalamic radiations (ATRs) and the severity of apathy. Regional grey matter atrophy did not account for any BPSD.
CONCLUSIONS
This study indicates that damage to the ATRs is strategic for the occurrence of apathy in patients with a-MCI. Disconnection between the prefrontal cortex and the mediodorsal and anterior thalamic nuclei might represent the pathophysiological substrate for apathy, which is one of the most common psychopathological symptoms observed in dementia
Eksperimentalno ponašanje prototipa matričnog pretvarača izvedenog s novim energetskim modulima
This paper describes the design and the solutions adopted for a matrix converter prototype of 10 kW, based on new integrated power modules. The performance of the converter is verified by means of experimental tests.Članak opisuje projekt i rješenja usvojena za prototip 10 kW matričnog pretvarača, izvedenog s novim integriranim energetskim modulima. Svojstva pretvarača provjerena su eksperimentalnim ispitivanjima
Eksperimentalno ponašanje prototipa matričnog pretvarača izvedenog s novim energetskim modulima
This paper describes the design and the solutions adopted for a matrix converter prototype of 10 kW, based on new integrated power modules. The performance of the converter is verified by means of experimental tests.Članak opisuje projekt i rješenja usvojena za prototip 10 kW matričnog pretvarača, izvedenog s novim integriranim energetskim modulima. Svojstva pretvarača provjerena su eksperimentalnim ispitivanjima
The social role of pediatrics in the past and present times
Pediatrics and society are closely related. This link is as old as the history of Pediatrics, and dates to the second half of the eighteenth century. The vocation of the first European pediatric schools, indeed, was clinical and scientific, as well as social. The founding fathers of Pediatrics were scientists of great talent, and many of them benefactors and philanthropists. They spent their lives assisting the suffering childhood, and became promoters and organizers of social securities for the poorest and most vulnerable categories. The attention to the problems of abandonment was closely linked to study, prevention, and treatment of pathologies (especially infectious, deficiency and neurological ones). The profile and activity of pediatricians grew in the following decades after the birth of the first pediatric schools. The University institutions contributed to provide a further impulse to childcare as well as cultural authority, also thanks to the foundation of the first chairs and scientific journals of Pediatrics. The relevance and prestige of the studies performed rapidly spread throughout Europe, and also reached our country, contributing to a progressive and relevant improvement in the quality of children’s care, and in the meantime to the decrease of neonatal and infant mortality rates.
Today’s pediatricians, as in the past, must spend his efforts to face the needs of children and their families, be their social receptor, interpreter if necessary, and credible and authoritative interlocutor beside institutions. The current coronavirus pandemic dramatically exposed social inequalities and inequities. In this new scenario, the pediatrician’s role of defender of all children becomes even more necessary and indispensable. Here we trace the historical steps which led to the birth and development of pediatrics, as independent medical discipline with ethical and social vocation. Its rise within the University institutions is analyzed, as well as the contribution of the greatest European and Italian masters. Finally, the role of today’s pediatrician is described, his responsibilities also in dealing with new health critical issues, related to the biological, cultural, and psychological changes of the patients of present days. He must have holistic competences, to effectively take care of all children. In addition, he must socially act to guarantee the best possible context for the well-being of the child
Enhancement of three-mode optomechanical interaction by feedback-controlled light
We realise a feedback-controlled optical Fabry-Perot cavity in which the
transmitted cavity output is used to modulate the input amplitude fluctuations.
The resulting phase-dependent fluctuations of the in-loop optical field, which
may be either sub-shot- or super-shot-noise, can be engineered to favorably
affect the optomechanical interaction with a nanomechanical membrane placed
within the cavity. Here we show that in the super-shot-noise regime
("anti-squashed light") the in-loop field has a strongly reduced effective
cavity linewidth, corresponding to an increased optomechanical cooperativity.
In this regime feedback improves the simultaneous resolved sideband cooling of
two nearly degenerate membrane mechanical modes by one order of magnitude.Comment: 16 pages, 11 figure
Enhancing sideband cooling by feedback--controlled light
We realise a phase-sensitive closed-loop control scheme to engineer the
fluctuations of the pump field which drives an optomechanical system, and show
that the corresponding cooling dynamics can be significantly improved. In
particular, operating in the counter-intuitive "anti-squashing" regime of
positive feedback and increased field fluctuations, sideband cooling of a
nanomechanical membrane within an optical cavity can be improved by 7.5~dB with
respect to the case without feedback. Close to the quantum regime of reduced
thermal noise, such feedback-controlled light would allow going well below the
quantum backaction cooling limit
Normal--mode splitting in a weakly coupled optomechanical system
Normal--mode splitting is the most evident signature of strong coupling
between two interacting subsystems. It occurs when two subsystems exchange
energy between themselves faster than they dissipate it to the environment.
Here we experimentally show that a weakly coupled optomechanical system at room
temperature can manifest normal--mode splitting when the pump field
fluctuations are anti-squashed by a phase-sensitive feedback loop operating
close to its instability threshold. Under these conditions the optical cavity
exhibits an effectively reduced decay rate, so that the system is effectively
promoted to the strong coupling regime
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