4,776 research outputs found
Layout level design for testability strategy applied to a CMOS cell library
The layout level design for testability (LLDFT) rules used here allow to avoid some hard to detect faults or even undetectable faults on a cell library by modifying the cell layout without changing their behavior and achieving a good level of reliability. These rules avoid some open faults or reduce their appearance probability. The main purpose has been to apply that set of LLDFT rules on the cells of the library designed at the Centre Nacional de Microelectronica (CNM) in order to obtain a highly testable cell library. The authors summarize the main results (area overhead and performance degradation) of the application of the LLDFT rules on the cell
Comprehensive Pain Management Using Opioids for Children and Adolescents: Still a Wild Goose to Chase?
Children and adolescents treated for acute and chronic pain represent particular vulnerable patients with distinct and unmet medical and psychosocial needs that continue even beyond the complexity of treating the diseases they suffer [...
On the Nature of MeV-blazars
Broad-band spectra of the FSRQ (flat-spectrum-radio quasars) detected in the
high energy gamma-ray band imply that there may be two types of such objects:
those with steep gamma-ray spectra, hereafter called MeV-blazars, and those
with flat gamma-ray spectra, GeV-blazars. We demonstrate that this difference
can be explained in the context of the ERC (external-radiation-Compton) model
using the same electron injection function. A satisfactory unification is
reachable, provided that: (a) spectra of GeV-blazars are produced by internal
shocks formed at the distances where cooling of relativistic electrons in a jet
is dominated by Comptonization of broad emission lines, whereas spectra of
MeV-blazars are produced at the distances where cooling of relativistic
electrons is dominated by Comptonization of near-IR radiation from hot dust;
(b) electrons are accelerated via a two step process and their injection
function takes the form of a double power-law, with the break corresponding to
the threshold energy for the diffusive shock acceleration. Direct predictions
of our model are that, on average, variability time scales of the MeV-blazars
should be longer than variability time scales of the GeV-blazars, and that both
types of the blazar phenomenon can appear in the same object.Comment: Accepted for publication in the Astrophysical Journa
Exact solution of the Zeeman effect in single-electron systems
Contrary to popular belief, the Zeeman effect can be treated exactly in
single-electron systems, for arbitrary magnetic field strengths, as long as the
term quadratic in the magnetic field can be ignored. These formulas were
actually derived already around 1927 by Darwin, using the classical picture of
angular momentum, and presented in their proper quantum-mechanical form in 1933
by Bethe, although without any proof. The expressions have since been more or
less lost from the literature; instead, the conventional treatment nowadays is
to present only the approximations for weak and strong fields, respectively.
However, in fusion research and other plasma physics applications, the magnetic
fields applied to control the shape and position of the plasma span the entire
region from weak to strong fields, and there is a need for a unified treatment.
In this paper we present the detailed quantum-mechanical derivation of the
exact eigenenergies and eigenstates of hydrogen-like atoms and ions in a static
magnetic field. Notably, these formulas are not much more complicated than the
better-known approximations. Moreover, the derivation allows the value of the
electron spin gyromagnetic ratio to be different from 2. For
completeness, we then review the details of dipole transitions between two
hydrogenic levels, and calculate the corresponding Zeeman spectrum. The various
approximations made in the derivation are also discussed in details.Comment: 18 pages, 4 figures. Submitted to Physica Script
Digital Phenotyping and Dynamic Monitoring of Adolescents Treated for Cancer to Guide Intervention: Embracing a New Era
The many faces of mitochondrial dysfunction in depression: From pathology to treatment
Introduction
The last years of neurobiological research have transformed the way we consider mental illnesses. We have gone from a deterministic genetic view to a broader vision that includes the involvement of non-cerebral systems. This is especially true for major depression (MD). Historically, MD has been perceived as a multifactorial disorder correlated to various neurobiological changes like neurotransmitter deficits, endocrine disturbances, impaired plasticity, and neural adaptation (Benatti et al., 2016). Indeed, the development and progression of depressive disorders has been conceived as the disruption of body allostasis, defined as the process of achieving stability of physiological and mental processes through dynamic change (Wang et al., 2019). The main player in the “allostatic game” is the brain, an organ designed to integrate signals from the periphery that anticipate fluctuations, changes, and needs and coordinates allostatic mediators in order to develop successful coping mechanisms that ultimately lead to an adaptative strategy and resilience (de Kloet et al., 2005).
The establishment and maintenance of these mechanisms requires large amounts of energy from the organism. Without energy, or in a partial lack of energy, the biological mechanisms necessary to respond appropriately to stimuli may not occur or be established incorrectly or abnormally.
Human and animal studies suggest an intriguing link between our body’s ability to produce energy and the brain’s ability to correctly perform the complex cellular and molecular processes involved in allostatic processes.
In eukaryotic cells, mitochondria are the powerhouse that produces and distributes energy to all other components. Functional or quantitative alterations of the ability of mitochondria to adequately supply energy can have important repercussions primarily on cellular processes and cascades of serial events (Herst et al., 2017) as well as on the correct functioning of the organism including mechanisms of brain plasticity, mood, and behavior in general (Allen et al., 2018). In this framework, it is particularly intriguing to think of the mitochondria as an active regulator of many of the biological phenomena involved in depression and in the efficacy of or resistance to the most widely used pharmacological treatments.
Once the energetic equilibrium is compromised, the body becomes more “vulnerable.” This is especially true for stress-related disorders, such as depression. In fact, depression is often associated with energetic imbalance leading to profound effects on the disease (Zuccoli et al., 2017). The driving questions then are as follows: What happens to the brain in the presence of an energetic imbalance? Does depression or depression-related symptoms impact mitochondrial energetic efficiency? Is antidepressant efficacy mediated by mitochondrial functionality
Narrative Review of the Complex Interaction between Pain and Trauma in Children: A Focus on Biological Memory, Preclinical Data, and Epigenetic Processes
The incidence and collective impact of early adverse experiences, trauma, and pain continue to increase. This underscores the urgent need for translational efforts between clinical and preclinical research to better understand the underlying mechanisms and develop effective therapeutic approaches. As our understanding of these issues improves from studies in children and adolescents, we can create more precise preclinical models and ultimately translate our findings back to clinical practice. A multidisciplinary approach is essential for addressing the complex and wide-ranging effects of these experiences on individuals and society. This narrative review aims to (1) define pain and trauma experiences in childhood and adolescents, (2) discuss the relationship between pain and trauma, (3) consider the role of biological memory, (4) decipher the relationship between pain and trauma using preclinical data, and (5) examine the role of the environment by introducing the importance of epigenetic processes. The ultimate scope is to better understand the wide-ranging effects of trauma, abuse, and chronic pain on children and adolescents, how they occur, and how to prevent or mitigate their effects and develop effective treatment strategies that address both the underlying causes and the associated physiological and psychological effects
Does the Blazar Gamma-Ray Spectrum Harden with Increasing Flux? Analysis of 9 Years of EGRET Data
The Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma-Ray
Observatory (CGRO) discovered gamma-ray emission from more than 67 blazars
during its 9 yr lifetime. We conducted an exhaustive search of the EGRET
archives and selected all the blazars that were observed multiple times and
were bright enough to enable a spectral analysis using standard power-law
models. The sample consists of 18 flat-spectrum radio quasars(FSRQs), 6
low-frequency peaked BL Lac objects (LBLs) and 2 high-frequency peaked BL Lac
objects (HBLs). We do not detect any clear pattern in the variation of spectral
index with flux. Some of the blazars do not show any statistical evidence for
spectral variability. The spectrum hardens with increasing flux in a few cases.
There is also evidence for a flux-hardness anticorrelation at low fluxes in
five blazars. The well-observed blazars (3C 279, 3C 273, PKS 0528+134, PKS
1622-297 PKS 0208-512) do not show any overall trend in the long-term spectral
dependence on flux, but the sample shows a mixture of hard and soft states. We
observed a previously unreported spectral hysteresis at weekly timescales in
all three FSRQs for which data from flares lasting for ~(3-4) weeks were
available. All three sources show a counterclockwise rotation, despite the
widely different flux profiles. We analyze the observed spectral behavior in
the context of various inverse Compton mechanisms believed to be responsible
for emission in the EGRET energy range. Our analysis uses the EGRET skymaps
that were regenerated to include the changes in performance during the mission
Universality in metallic nanocohesion: a quantum chaos approach
Convergent semiclassical trace formulae for the density of states and
cohesive force of a narrow constriction in an electron gas, whose classical
motion is either chaotic or integrable, are derived. It is shown that mode
quantization in a metallic point contact or nanowire leads to universal
oscillations in its cohesive force: the amplitude of the oscillations depends
only on a dimensionless quantum parameter describing the crossover from chaotic
to integrable motion, and is of order 1 nano-Newton, in agreement with recent
experiments. Interestingly, quantum tunneling is shown to be described
quantitatively in terms of the instability of the classical periodic orbits.Comment: corrects spelling of one author name on abstract page (paper is
unchanged
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