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1.
Phys Rev Lett ; 132(20): 202701, 2024 May 17.
Article in English | MEDLINE | ID: mdl-38829093

ABSTRACT

New astronomical observations point to a nucleosynthesis picture that goes beyond what was accepted until recently. The intermediate "i" process was proposed as a plausible scenario to explain some of the unusual abundance patterns observed in metal-poor stars. The most important nuclear physics properties entering i-process calculations are the neutron-capture cross sections and they are almost exclusively not known experimentally. Here we provide the first experimental constraints on the ^{139}Ba(n,γ)^{140}Ba reaction rate, which is the dominant source of uncertainty for the production of lanthanum, a key indicator of i-process conditions. This is an important step towards identifying the exact astrophysical site of stars carrying the i-process signature.

2.
Clin Neurophysiol ; 121(12): 2024-34, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20566300

ABSTRACT

OBJECTIVE: Brain processing at varying levels of functional complexity has been documented in vegetative state. In this study, data mining procedures are applied to identify significant changes in heart rate variability (an emerging objective descriptor of autonomic correlates of brain activation) in response to complex auditory stimuli with emotional value (music). METHODS: The heart rate of subjects in vegetative state from brain damage (n=6) or spontaneous hemorrhage (n=3) and 16 healthy controls was recorded while they passively listened to four pre-selected music samples by different authors (mean recording time: 3m and 36s±24s). The parametric and non-parametric frequency spectra were computed on the heart rate, spectra were compared within/across subjects and music authors, and the spectra descriptors were entered into a 1-R rules data mining procedure (WEKA software Leave One Out and Ten Fold Cross validation). The procedure independently classified the heart rate spectral patterns of both patients and controls and the emotions reported by healthy subjects as "positive" or "negative". RESULTS: In both healthy controls and vegetative state subjects, the power spectra while passively listening to music differed from baseline when compared irrespective of the music authorship and from each other when compared across music samples. Data mining sorted the nu_LF (normalized parameter unit of the spectrum low frequency range) as the significant descriptor of heart rate variability in the conditions of the study. The nu_LF classification of the healthy controls' HRV changes in response to music replicated that based on subjective reports with 75-93.7% accuracy. CONCLUSIONS: Although preliminary, these findings suggest that autonomic changes with possible emotional value can be induced by complex stimuli also in vegetative state, with implications on the residual responsiveness of these subjects. SIGNIFICANCE: Heart rate variability descriptors and data mining methods appear applicable to investigate brain function in the absence of consciousness.


Subject(s)
Artificial Intelligence , Brain/physiopathology , Data Mining , Heart Rate/physiology , Persistent Vegetative State/pathology , Persistent Vegetative State/physiopathology , Acoustic Stimulation/methods , Adolescent , Adult , Brain Injuries/complications , Data Mining/statistics & numerical data , Emotions/physiology , Female , Humans , Intracranial Hemorrhages/complications , Male , Middle Aged , Music , Photoplethysmography/methods , Statistics as Topic , Young Adult
3.
Brain Inj ; 22(7-8): 617-23, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18568716

ABSTRACT

BACKGROUND AND PURPOSE: Residual brain function has been documented in vegetative state patients, yet early prognosis remains difficult. The purpose of this study was to identify by artificial intelligence procedures (classification and regression trees, data-mining) the significant neurological signs correlated to and predictive of outcome. METHODS: Three hundred and thirty-three patients in vegetative state of traumatic or non-traumatic aetiology referred to the S.Anna Institute were retrospectively studied. Twenty-two neurological signs were assessed according to criteria included in the UNI ENI ISO 9001 : 2000 quality standards at admission (Time(0)) and after 50, 100 or 180 days and entered into a CART (classification and regression tree) data-mining procedure with a decisional tree j48 (Weka software and 10-fold cross-validation). Outcome was conventionally rated by the Glasgow outcome scale. RESULTS AND CONCLUSIONS: Re-appearance with proper timing of spontaneous motility, eye tracking and oculo-cephalic reflex and disappearance of oral automatisms proved highly correlated to outcome and allowed early and reliable prognosis. These findings are consistent with the brain functional organization thought to sustain consciousness and warrant systematic investigation. Classification and regression trees and data-mining procedures proved applicable in neurology to sort out significant clinical signs also in clinical conditions characterized by paucity of signs such as the vegetative state. Extended application in clinical medicine is conceivable based on the approach peculiarities.


Subject(s)
Decision Trees , Neurologic Examination/methods , Persistent Vegetative State/physiopathology , Adolescent , Adult , Aged , Electronic Data Processing/methods , Female , Glasgow Coma Scale , Humans , Male , Middle Aged , Persistent Vegetative State/classification , Predictive Value of Tests , Prognosis , Retrospective Studies
4.
Exp Eye Res ; 45(5): 647-54, 1987 Nov.
Article in English | MEDLINE | ID: mdl-3428390

ABSTRACT

The effects of the instillation of a PGE2-analogue (11-deoxy-13,14-didehydro-16 (S)-methyl PGE2 methylester: FCE 20700) in the conjunctival sac of the rabbit were studied by means of two methods. The former is a clinical study (Dohlman test), the latter is a morphological investigation (semithin sections) on specimens of the conjunctival mucosa. From both methods it was possible to demonstrate that the FCE 20700 instillation enhanced the mucous lacrimal secretion in rabbits.


Subject(s)
Conjunctiva/drug effects , Dinoprostone/analogs & derivatives , Prostaglandins E, Synthetic/pharmacology , Animals , Cell Count , Conjunctiva/cytology , Conjunctiva/metabolism , Cytoplasmic Granules/drug effects , Epithelial Cells , Epithelium/drug effects , Exocrine Glands/cytology , Male , Mucus/metabolism , Rabbits , Stimulation, Chemical , Tears/metabolism , Time Factors
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