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We investigate the possibility of optimization of ultrashort laser pulses by spectral phase modulation using machine learning algorithms. We compare the efficiency of two algorithms: Grey Wolf Optimizer and Genetic Algorithm.

This experiment aimed to characterize Gain-Managed Nonlinear amplification (GMN) in Erbium-doped fibers. This effect has so far been presented in Ytterbium-doped fibers and only simulated on Erbium-doped fibers.

Background and Hypothesis: Psychopathic traits play an important role in schizophrenia, particularly for violent behavior. There have been very few functional imaging studies (fMRI) examining the impact of brain dysfunction on psychopathic traits in schizophrenia. Our goal was to evaluate neural abnormalities underlying these traits through fMRI in violent subjects with schizophrenia (VS) and in 3 comparison groups: healthy controls (HC), nonviolent patients (NV), and nonpsychotic violent subjects (NPV)., Study Design: fMRI imaging was used to measure blood-oxygen-level-dependent activation in 95 subjects while they performed a Go/NoGo task: 26 VS, 25 NPV, 26 HC, and 18 NVS. Psychopathy was evaluated through the 2 factors of the Psychopathy Checklist (PCL:SV). The subjects were also evaluated for psychiatric symptoms and for educational achievement., Study Results: Hypoactivation of brain areas involved in response inhibition was related to the severity of psychopathic traits in the violent patients with schizophrenia. These areas included frontal regions, cingulate cortex, insula, precuneus, and basal ganglia. This association was very strong for the first PCL:SV factor, the affective-interpersonal traits, and moderate for the second PCL:SV factor, the antisocial-impulsive traits. The latter traits were also linked to poor educational achievement., Conclusions: The 2 psychopathic factors have different antecedents and are dissociable at the neural level in schizophrenia. Brain dysfunction is more strongly associated with the affective-interpersonal traits while the antisocial traits are associated with various factors. This has important implications for the conceptualization and treatment of violence in patients with schizophrenia., (© The Author(s) 2023. Published by Oxford University Press on behalf of the University of Maryland's school of medicine, Maryland Psychiatric Research Center.)

Several structural brain abnormalities have been associated with aggression in patients with schizophrenia. However, little is known about shared and distinct abnormalities underlying aggression in these subjects and non-psychotic violent individuals. We applied a region-of-interest volumetric analysis of the amygdala, hippocampus, and thalamus bilaterally, as well as whole brain and ventricular volumes to investigate violent (n = 37) and non-violent chronic patients (n = 26) with schizophrenia, non-psychotic violent (n = 24) as well as healthy control subjects (n = 24). Shared and distinct volumetric abnormalities were probed by analysis of variance with the factors violence (non-violent versus violent) and diagnosis (non-psychotic versus psychotic), adjusted for substance abuse, age, academic achievement and negative psychotic symptoms. Patients showed elevated vCSF volume, smaller left hippocampus and smaller left thalamus volumes. This was particularly the case for non-violent individuals diagnosed with schizophrenia. Furthermore, patients had reduction in right thalamus size. With regard to left amygdala, we found an interaction between violence and diagnosis. More specifically, we report a double dissociation with smaller amygdala size linked to violence in non-psychotic individuals, while for psychotic patients smaller size was linked to non-violence. Importantly, the double dissociation appeared to be mostly driven by substance abuse. Overall, we found widespread morphometric abnormalities in subcortical regions in schizophrenia. No evidence for shared volumetric abnormalities in individuals with a history of violence was found. Finally, left amygdala abnormalities in non-psychotic violent individuals were largely accounted for by substance abuse. This might be an indication that the association between amygdala reduction and violence is mediated by substance abuse. Our results indicate the importance of structural abnormalities in aggressive individuals., Competing Interests: The authors have declared that no competing interests exist.

Objective: Increased susceptibility to emotional triggers and poor response inhibition are important in the etiology of violence in schizophrenia. Our goal was to evaluate abnormalities in neurophysiological mechanisms underlying response inhibition and emotional processing in violent patients with schizophrenia (VS) and 3 different comparison groups: nonviolent patients (NV), healthy controls (HC) and nonpsychotic violent subjects (NPV)., Methods: We recorded high-density Event-Related Potentials (ERPs) and behavioral responses during an Emotional Go/NoGo Task in 35 VS, 24 NV, 28 HC and 31 NPV subjects. We also evaluated psychiatric symptoms and impulsivity., Results: The neural and behavioral deficits in violent patients were most pronounced when they were presented with negative emotional stimuli: They responded more quickly than NV when they made commission errors (ie, failure of inhibition), and evidenced N2 increases and P3 decreases. In contrast, NVs showed little change in reaction time or ERP amplitude with emotional stimuli. These N2 and P3 amplitude changes in VSs showed a strong association with greater impulsivity. Besides these group specific changes, VSs shared deficits with NV, mostly N2 reduction, and with violent nonpsychotic subjects, particularly P3 reduction., Conclusion: Negative affective triggers have a strong impact on violent patients with schizophrenia which may have both behavioral and neural manifestations. The resulting activation could interfere with response inhibition. The affective disruption of response inhibition, identified in this study, may index an important pathway to violence in schizophrenia and suggest new modes of treatment., (© The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Difficulties with affect regulation and impulse control have a strong influence on violence. The objective of this study was to determine whether baseline depression and impulsivity predict aggression and whether they predict differential response to antiaggressive treatment. This is important, as we lack knowledge as to the selection of antipsychotics for the treatment of aggression., Methods: Physically aggressive inpatients with schizophrenia who received an evaluation of depression and impulsivity at baseline were randomly assigned in a double-blind, parallel group, 12-week trial to clozapine, olanzapine, or haloperidol. Trait impulsivity was measured by the Barratt Impulsiveness Scale; depression by the Positive and Negative Syndrome Scale Depression factor. The number and severity of aggressive events, as measured by the Modified Overt Aggression Scale (MOAS), were the outcome measures., Results: Baseline depression and impulsivity predicted higher levels of aggression, as measured by the MOAS total score, over the 12-week treatment period across all 3 medication groups. In addition, there was a strong interaction effect between baseline depression/impulsivity and medication grouping in predicting MOAS score. In particular, when higher depression and impulsivity were present at baseline, patients on haloperidol presented with more aggression than patients on the other 3 medications., Conclusions: Depression and impulsivity are important predictors of aggression and of differential response to antiaggressive treatment. This is most likely due to the medications' dissimilar neurotransmitter profiles. By identifying patients who will respond better to a given medication, we will be able to develop individualized strategies for the treatment of violent behavior., (© The Author 2013. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Individuals with schizophrenia are more prone to violent behaviors than the general population. It is increasingly recognized that processing of emotionally valenced stimuli is impaired in schizophrenia, a deficit that may play a role in aggressive behavior. Our goal was to establish whether patients with a history of violence would show more severe deficits in processing emotionally valenced inputs than non-violent patients. Using event-related potentials, we measured how early during processing of emotional valence, evidence of aberrant function was observed. A total of 42 schizophrenia patients (21 with history of violence; 21 without) and 28 healthy controls were tested. Participants performed an inhibitory control task, making speeded responses to pictorial stimuli. Pictures occasionally repeated twice and participants withheld responses to these repeats. Valenced pictures from the International Affective Picture System were presented. Results in controls showed modulations during the earliest phases of sensory processing (<100 ms) for negatively valenced pictures. A cascade of modulations ensued, involving sensory and perceptual processing stages. In contrast, neither schizophrenia group showed early differentiation. Non-violent patients showed earliest modulations beginning ∼150 ms. For violent patients, however, earliest modulations were further delayed and highly attenuated. The current study reveals sensory-perceptual processing dysfunction for negatively valenced inputs, which is particularly pronounced in aggressive patients.

Objectives: To better understand the relationship between suicidal behavior and violence directed toward others among patients with major psychiatric disorders, this study examined how suicide attempts and violent behaviors were associated with various psychosocial problems., Methods: Participants were inpatients in two psychiatric state hospitals. They included 216 inpatients who had physically assaulted another patient or a staff member and a comparison group of 81 inpatients who had not assaulted anyone. History of suicide attempts and historical information about various risk factors for violence and suicide were obtained through chart review and patient interviews., Results: Patients in the violent group did not differ from those in the nonviolent group in whether they had attempted suicide. Suicide attempts and violence were associated with different historical variables. Suicide attempts were associated with a history of head trauma, harsh parental discipline, and parental psychopathology. Violence against others was associated with having a history of school truancy and foster home placement., Conclusions: Among inpatients with major psychiatric disorders, violence and suicide attempts were not related to each other and were associated with dissimilar psychosocial risk factors.