Search results for " function"

Singular solutions to p-Laplacian type equations

1999

We construct singular solutions to equations $div\mathcal{A}(x,\nabla u) = 0,$ similar to the p-Laplacian, that tend to ∞ on a given closed set of p-capacity zero. Moreover, we show that every Gδ-set of vanishing p-capacity is the infinity set of some A-superharmonic function.

Real-Time Observation of “Soft” Magic-Size Clusters during Hydrolysis of the Model Metallodrug Bismuth Disalicylate

2021

International audience; Colloidal bismuth therapeutics have been used for hundreds of years, yet remain mysterious. Here we report an X-ray pair distribution function (PDF) study of the solvolysis of bismuth disalicylate, a model for the metallodrug bismuth subsalicylate (Pepto-Bismol). This reveals catalysis by traces of water, followed by multistep cluster growth. The ratio of the two major species, {Bi9O7} and {Bi38O44}, depends on exposure to air, time, and the solvent. The solution-phase cluster structures are of significantly higher symmetry in comparison to solid-state analogues, with reduced off-center Bi3+ displacements. This explains why such “magic-size” clusters can be both stab…

An expansion–coalescence model to track gas bubble populations in magmas

2016

Abstract We propose a kinetic model that statistically describes the growth by decompression, exsolution and coalescence of a polydisperse population of gas bubbles in a silicate melt. The model is homogeneous in space and its main variable is a distribution function representing the probability to find a bubble of volume v and mass m at time t. The volume and mass growth rates are described by a simplification of the classical monodisperse bubble growth model. This simplification, which shortens computational time, removes the coupling between mass evolution and an advection–diffusion equation describing the behavior of the volatile concentration in the melt. We formulate three coalescence…

Phytoplankton dynamics in permanent and temporary Mediterranean waters: is the game hard to play because of hydrological disturbance?

2012

Only few scientific investigations have been carried out, to our knowledge, on phytoplankton in Mediterranean temporary ponds. To test the hypothesis that climate forcing is the main factor affecting dynamics and structure of planktic algae in these peculiar ecosystems, and to assess the importance of human impacts on this basic component of the aquatic biota, phytoplankton structure and dynamics were analysed in two temporary, long lasting (9 months), ponds, and in a permanent one. The three studied water bodies can be classified as mesoeutrophic, which show extended macrophyte beds and are subjected to one or more human impacts, such as eutrophication, fish and plant introduction, and gar…

Evaluation of legendre functions of argument greater than one

1997

Abstract In this paper we present an algorithm to evaluate Legendre functions of the first and second kinds ( P v , Q v ) for integraland half-integral order and argument greater than one. The code is based on the calculation of the continued fraction for the Q 's. the Wronskian relating P 's and Q 's and the application of forward recurrence relations for the P 's and backward recurrence for the Q 's. We also show an application of these algorithms to the evaluation of the electrostatic field due to a charged toroidal conductor at potential V .

The complex cognitive system of executive functioning: A conceptual review

2018

Every day we are faced with a variety of situations that require the use of cognitive processes different, such as recognizing and memorizing stimuli, understanding and producing statements, solving problems. In recent decades, cognitive psychology and neuropsychology have made considerable advances in description of these processes and how they can be disrupted as a result of an injury to the nervous system central. However, it is clear that our adaptation to the environment is not limited to perceiving, reading, and speaking. A fundamental aspect of mental life is represented by the need to continuously modulate the use of these cognitive resources to contingent needs according to our goa…

2013

The amyloid-β42 (Aβ42) peptide plays a crucial role in the pathogenesis of Alzheimer’s disease (AD), the most common neurodegenerative disorder affecting the elderly. Over the past years, several approaches and compounds developed for the treatment of AD have failed in clinical studies, likely in part due to their low penetration of the blood–brain barrier (BBB). Since nanotechnology-based strategies offer new possibilities for the delivery of drugs to the brain, this technique is studied intensively for the treatment of AD and other neurological disorders. The Aβ42 lowering drug flurbiprofen was embedded in polylactide (PLA) nanoparticles by emulsification-diffusion technique and their pot…

Right-handers and left-handers have different representations of their own hand

1998

The visual control of our own hand when dealing with an object and the observation of interactions between other people's hand and objects can be involved in the construction of internal representations of our own hand, as well as in hand recognition processes. Therefore, a different effect on handedness recognition is expected when subjects are presented with hands holding objects with either a congruent or an incongruent type of grip. Such an experiment was carried out on right-handed and left-handed subjects. We expected that the different degree of lateralisation in motor activities observed in the two populations [J. Herron, Neuropsychology of left- handedness, Academic Press, New York…

The Interaction of Person-Affect-Cognition-Execution (I-PACE) model for addictive behaviors: Update, generalization to addictive behaviors beyond int…

2019

We propose an updated version of the Interaction of Person-Affect-Cognition-Execution (I-PACE) model, which we argue to be valid for several types of addictive behaviors, such as gambling, gaming, buying-shopping, and compulsive sexual behavior disorders. Based on recent empirical findings and theoretical considerations, we argue that addictive behaviors develop as a consequence of the interactions between predisposing variables, affective and cognitive responses to specific stimuli, and executive functions, such as inhibitory control and decision-making. In the process of addictive behaviors, the associations between cue-reactivity/craving and diminished inhibitory control contribute to th…

Musical training facilitates the neural discrimination of major versus minor chords in 13-year-old children

2012

Music practice since childhood affects the development of hearing skills. An important classification in Western music is the chords’ major-minor dichotomy. Its preattentive auditory discrimination was studied here using a mismatch negativity (MMN) paradigm in 13-year-olds with active hobbies, music-related (music group) or other (control group). In a context of root major chords, root minor chords and inverted major chords were presented infrequently. The interval structure of inverted majors differs more from root majors than the interval structure of root minors. However, the identity of the chords is the same in inverted and root majors (major), but different in root minors. The deviant…