873 research outputs found
Response potential in the strong-interaction limit of DFT: Analysis and comparison with the coupling-constant average
Using the formalism of the conditional amplitude, we study the response part
of the exchange-correlation potential in the strong-coupling limit of density
functional theory, analysing its peculiar features and comparing it with the
response potential averaged over the coupling constant for small atoms and for
the hydrogen molecule. We also use a simple one-dimensional model of a
stretched heteronuclear molecule to derive exact properties of the response
potential in the strong-coupling limit. The simplicity of the model allows us
to unveil relevant features also of the exact Kohn-Sham potential and its
different components, namely the appearance of a second peak in the correlation
kinetic potential on the side of the most electronegative atom.Comment: 18 pages, 13 figures. New version where we have corrected some error
Influence of insulating materials on green building rating system results
This paper analyzes the impact of a change in the thermal insulating material on both the energy and environmental performance of a building, evaluated through two different green building assessment methods: Leadership in Energy and Environmental Design (LEED) and Istituto per l'innovazione e Trasparenza degli Appalti e la Compatibilità Ambientale (ITACA). LEED is one of the most qualified rating systems at an international level; it assesses building sustainability thanks to a point-based system where credits are divided into six different categories. One of these is fully related to building materials. The ITACA procedure derives from the international evaluation system Sustainable Building Tool (SBTool), modified according to the Italian context. In the region of Umbria, ITACA certification is composed of 20 technical sheets, which are classified into five macro-areas. The analysis was developed on a residential building located in the central Italy. It was built taking into account the principles of sustainability as far as both structural and technical solutions are concerned. In order to evaluate the influence of thermal insulating material, different configurations of the envelope were considered, replacing the original material (glass wool) with a synthetic one (expanded polystyrene, EPS) and two natural materials (wood fiber and kenaf). The study aims to highlight how the materials characteristics can affect building energy and environmental performance and to point out the different approaches of the analyzed protocols
Sum-rules of the response potential in the strongly-interacting limit of DFT
The response part of the exchange-correlation potential of Kohn-Sham density
functional theory plays a very important role, for example for the calculation
of accurate band gaps and excitation energies. Here we analyze this part of the
potential in the limit of infinite interaction in density functional theory,
showing that in the one-dimensional case it satisfies a very simple sum rule.Comment: 7 page
Episodic and semantic autobiographical memory in temporal lobe epilepsy
Autobiographical memory (AM) is understood as the retrieval of personal experiences that occurred in specific time and space. To date, there is no consensus on the role of medial temporal lobe structures in AM. Therefore, we investigated AM in medial temporal lobe epilepsy (TLE) patients. Twenty TLE patients candidates for surgical treatment, 10 right (RTLE) and 10 left (LTLE), and 20 healthy controls were examined with a version of the Autobiographical Interview adapted to Spanish language. Episodic and semantic AM were analyzed during five life periods through two conditions: recall and specific probe. AM scores were compared with clinical and cognitive data. TLE patients showed lower performance in episodic AM than healthy controls, being significantly worst in RTLE group and after specific probe. In relation to semantic AM, LTLE retrieved higher amount of total semantic details compared to controls during recall, but not after specific probe. No significant differences were found between RTLE and LTLE, but a trend towards poorer performance in RTLE group was found. TLE patients obtained lower scores for adolescence period memories after specific probe. Our findings support the idea that the right hippocampus would play a more important role in episodic retrieval than the left, regardless of a temporal gradient.Fil: Múnera MartÃnez, Claudia Patricia. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos MejÃa"; ArgentinaFil: Lomlomdjian, Ana Carolina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos MejÃa"; ArgentinaFil: Gori, MarÃa Belén. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos MejÃa"; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Terpiluk, Veronica. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos MejÃa"; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Medel, Nancy Ruth. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos MejÃa"; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Solis, Patricia. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos MejÃa"; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Kochen, Sara Silvia. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos MejÃa"; Argentin
One-class support vector machines identify the language and default mode regions as common patterns of structural alterations in young children with autism spectrum disorders
The identification of reliable brain endophenotypes of autism spectrum disorders (ASD) has been hampered to date by the heterogeneity in the neuroanatomical abnormalities detected in this condition. To handle the complexity of neuroimaging data and to convert brain images in informative biomarkers of pathology, multivariate analysis techniques based on Support Vector Machines (SVM) have been widely used in several disease conditions. They are usually trained to distinguish patients from healthy control subjects by making a binary classification. Here, we propose the use of the One-Class Classification (OCC) or Data Description method that, in contrast to two-class classification, is based on a description of one class of objects only. This approach, by defining a multivariate normative rule on one class of subjects, allows recognizing examples from a different category as outliers. We applied the OCC to 314 regional features extracted from brain structural Magnetic Resonance Imaging (MRI) scans of young children with ASD (21 males and 20 females) and control subjects (20 males and 20 females), matched on age [range: 22-72 months of age; mean = 49 months] and non-verbal intelligence quotient (NVIQ) [range: 31-123; mean = 73]. We demonstrated that a common pattern of features characterize the ASD population. The OCC SVM trained on the group of ASD subjects showed the following performances in the ASD vs. controls separation: the area under the receiver operating characteristic curve (AUC) was 0.74 for the male and 0.68 for the female population, respectively. Notably, the ASD vs. controls discrimination results were maximized when evaluated on the subsamples of subjects with NVIQ = 70, leading to AUC = 0.81 for the male and AUC = 0.72 for the female populations, respectively. Language regions and regions from the default mode network-posterior cingulate cortex, pars opercularis and pars triangularis of the inferior frontal gyrus, and transverse temporal gyrus-contributed most to distinguishing individuals with ASD from controls, arguing for the crucial role of these areas in the ASD pathophysiology. The observed brain patterns associate preschoolers with ASD independently of their age, gender and NVIQ and therefore they are expected to constitute part of the ASD brain endophenotype
Communication:Strong-interaction limit of an adiabatic connection in Hartree-Fock theory
We show that the leading term in the strong-interaction limit of the adiabatic connection that has as weak-interaction expansion the Møller-Plesset perturbation theory can be fully determined from a functional of the Hartree-Fock density. We analyze this functional and highlight similarities and differences with the strong-interaction limit of the density-fixed adiabatic connection case of Kohn-Sham density functional theory
Multisensory Perception and Learning: Linking Pedagogy, Psychophysics, and Human–Computer Interaction
In this review, we discuss how specific sensory channels can mediate the learning of properties of the environment. In recent years, schools have increasingly been using multisensory technology for teaching. However, it still needs to be sufficiently grounded in neuroscientific and pedagogical evidence. Researchers have recently renewed understanding around the role of communication between sensory modalities during development. In the current review, we outline four principles that will aid technological development based on theoretical models of multisensory development and embodiment to foster in-depth, perceptual, and conceptual learning of mathematics. We also discuss how a multidisciplinary approach offers a unique contribution to development of new practical solutions for learning in school. Scientists, engineers, and pedagogical experts offer their interdisciplinary points of view on this topic. At the end of the review, we present our results, showing that one can use multiple sensory inputs and sensorimotor associations in multisensory technology to improve the discrimination of angles, but also possibly for educational purposes. Finally, we present an application, the ‘RobotAngle’ developed for primary (i.e., elementary) school children, which uses sounds and body movements to learn about angles
Dissecting Adaptation Mechanisms to Contrasting Solar Irradiance in the Mediterranean Shrub Cistus incanus
Molecular mechanisms that are the base of the strategies adopted by Mediterranean plants to cope with the challenges imposed by limited or excessive solar radiation during the summer season have received limited attention. In our study, conducted on C. incanus plants growing in the shade or in full sunlight, we performed measurements of relevant physiological traits, such as leaf water potential, gas exchange and PSII photochemistry, RNA-Seq with de-novo assembly, and the analysis of differentially expressed genes. We also identified and quantified photosynthetic pigments, abscisic acid, and flavonoids. Here, we show major mechanisms regulating light perception and signaling which, in turn, sustain the shade avoidance syndrome displayed by the ‘sun loving’ C. incanus. We offer clear evidence of the detrimental effects of excessive light on both the assembly and the stability of PSII, and the activation of a suite of both repair and effective antioxidant mechanisms in sun-adapted leaves. For instance, our study supports the view of major antioxidant functions of zeaxanthin in sunny plants concomitantly challenged by severe drought stress. Finally, our study confirms the multiple functions served by flavonoids, both flavonols and flavanols, in the adaptive mechanisms of plants to the environmental pressures associated to Mediterranean climate
Assessing Social Anxiety Disorder : Psychometric Properties of the Italian Social Phobia Inventory (I-SPIN)
Social Phobia, one of the most common psychological disorders, can cause serious discomfort and impairment in a person’s life. The importance of assessing the specific features of this disorder is well-known. This paper assesses the psychometric properties of the Italian version of the Social Phobia Inventory (I-SPIN)
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