Search results for "methods"

Implications of irradiating the subventricular zone stem cell niche

2016

Radiation therapy is a standard treatment for brain tumor patients. However, it comes with side effects, such as neurological deficits. While likely multi-factorial, the effect may in part be associated with the impact of radiation on the neurogenic niches. In the adult mammalian brain, the neurogenic niches are localized in the subventricular zone (SVZ) of the lateral ventricles and the dentate gyrus of the hippocampus, where the neural stem cells (NSCs) reside. Several reports showed that radiation produces a drastic decrease in the proliferative capacity of these regions, which is related to functional decline. In particular, radiation to the SVZ led to a reduced long-term olfactory memo…

A systematic review of animal models for experimental neuroma

2015

Summary Peripheral neuromas can result in an unbearable neuropathic pain and functional impairment. Their treatment is still challenging, and their optimal management is to be defined. Experimental research still plays a major role, but - although numerous neuroma models have been proposed on different animals - there is still no single model recognised as being the reference. Several models show advantages over the others in specific aspects of neuroma physiopathology, prevention or treatment, making it unlikely that a single model could be of reference. A reproducible and standardised model of peripheral neuroma would allow better comparison of results from different studies. We present a…

Neuroticism may reflect emotional variability when correcting for the confound with the mean

2020

Kalokerinos et al. (1) demonstrate that emotional variability, as assessed via the SD, is not significantly associated with neuroticism once the confound with mean negative emotion is controlled for, r = 0.05. To control for this confound, the authors use the relative SD (RSD), which mathematically corrects for the nonlinear dependency between the SD and the mean (2). The authors prefer the RSD over including the SD and the mean of negative emotions in a model, given the nonlinearity of their association. While we agree that the RSD is an important addition to the field, we argue that including the mean of emotions is still necessary when examining the association between neuroticism and em…

The next-generation liquid-scintillator neutrino observatory LENA

2012

We propose the liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) as a next-generation neutrino observatory on the scale of 50 kt. The outstanding successes of the Borexino and KamLAND experiments demonstrate the large potential of liquid-scintillator detectors in low-energy neutrino physics. LENA's physics objectives comprise the observation of astrophysical and terrestrial neutrino sources as well as the investigation of neutrino oscillations. In the GeV energy range, the search for proton decay and long-baseline neutrino oscillation experiments complement the low-energy program. Based on the considerable expertise present in European and international research groups, the …

Nuovo realismo e metodi di ricerca misti

2014

Il nuovo realismo ha evidenziato i limiti del costruttivismo sociale e del cosiddetto «pensiero debole», che rischia di sfociare nel nichilismo. Sono stati recentemente rimossi dei pregiudizi che impedivano di cogliere la realtà dei fatti educativi nella sua concreta evidenza. Tuttavia un’apertura alla prospettiva metafisica offrirebbe al nuovo realismo ulteriori spazi epistemologici. In tale senso il contributo del realismo critico potrebbe aiutare a superare l’artificiosa antinomia tra il ruolo attivo del soggetto conoscente e la rilevazione oggettiva dei fatti educativi. Se si realizzasse questa apertura la conoscenza scientifica e la conoscenza corrente non sarebbero più viste come anti…

High-quality discretizations for microwave simulations

2016

We apply high-quality discretizations to simulate electromagnetic microwaves. Instead of the vector field presentations, we focus on differential forms and discretize the model in the spatial domain using the discrete exterior calculus. At the discrete level, both the Hodge operators and the time discretization are optimized for time-harmonic simulations. Non-uniform spatial and temporal discretization are applied in problems in which the wavelength is highly-variable and geometry contains sub-wavelength structures. peerReviewed

Signal-to-noise ratio in reproducing kernel Hilbert spaces

2018

This paper introduces the kernel signal-to-noise ratio (kSNR) for different machine learning and signal processing applications}. The kSNR seeks to maximize the signal variance while minimizing the estimated noise variance explicitly in a reproducing kernel Hilbert space (rkHs). The kSNR gives rise to considering complex signal-to-noise relations beyond additive noise models, and can be seen as a useful signal-to-noise regularizer for feature extraction and dimensionality reduction. We show that the kSNR generalizes kernel PCA (and other spectral dimensionality reduction methods), least squares SVM, and kernel ridge regression to deal with cases where signal and noise cannot be assumed inde…

Existence and uniqueness of nontrivial collocation solutions of implicitly linear homogeneous Volterra integral equations

2011

We analyze collocation methods for nonlinear homogeneous Volterra-Hammerstein integral equations with non-Lipschitz nonlinearity. We present different kinds of existence and uniqueness of nontrivial collocation solutions and we give conditions for such existence and uniqueness in some cases. Finally we illustrate these methods with an example of a collocation problem, and we give some examples of collocation problems that do not fit in the cases studied previously.

Distribution Dynamics and Nonlinear Growth

2003

Three dimensional reductions of four-dimensional quasilinear systems

2017

In this paper we show that integrable four dimensional linearly degenerate equations of second order possess infinitely many three dimensional hydrodynamic reductions. Furthermore, they are equipped infinitely many conservation laws and higher commuting flows. We show that the dispersionless limits of nonlocal KdV and nonlocal NLS equations (the so-called Breaking Soliton equations introduced by O.I. Bogoyavlenski) are one and two component reductions (respectively) of one of these four dimensional linearly degenerate equations.