Quantitative Analysis and Performance Study of Ant Colony Optimization Models Applied to Multi-Mode Resource Constraint Project Scheduling Problem

Constraint Satisfaction Problems (CSP) belongs to this kind of traditional NP-hard problems with a high impact in both, research and industrial domains. However, due to the complexity that CSP problems exhibit, researchers are forced to use heuristic algorithms for solving the problems in a reasonable time. One of the most famous heuristic al- gorithms is Ant Colony Optimization (ACO) algorithm. The possible utilization of ACO algorithms to solve CSP problems requires the de- sign of a decision graph where the ACO is executed. Nevertheless, the classical approaches build a graph where the nodes represent the vari- able/value pairs and the edges connect those nodes whose variables are different. In order to solve this problem, a novel ACO model have been recently designed. The goal of this paper is to analyze the performance of this novelty algorithm when solving Multi-Mode Resource-Constraint Satisfaction Problems. Experimental results reveals that the new ACO model provides competitive results whereas the number of pheromones created in the system is drastically reduced

Comparative study of pheromone control heuristics in ACO algorithms for solving RCPSP problems

Constraint Satisfaction Problems (CSP) belong to a kind of traditional NP-hard problems with a high impact on both research and industrial domains. The goal of these problems is to find a feasible assignment for a group of variables where a set of imposed restrictions is satisfied. This family of NP-hard problems demands a huge amount of computational resources even for their simplest cases. For this reason, different heuristic methods have been studied so far in order to discover feasible solutions at an affordable complexity level. This paper elaborates on the application of Ant Colony Optimization (ACO) algorithms with a novel CSP-graph based model to solve Resource-Constrained Project Scheduling Problems (RCPSP). The main drawback of this ACO-based model is related to the high number of pheromones created in the system. To overcome this issue we propose two adaptive Oblivion Rate heuristics to control the number of pheromones: the first one, called Dynamic Oblivion Rate, takes into account the overall number of pheromones produced in the system, whereas the second one inspires from the recently contributed Coral Reef Optimization (CRO) solver. A thorough experimental analysis has been carried out using the public PSPLIB library, and the obtained results have been compared to those of the most relevant contributions from the related literature. The performed experiments reveal that the Oblivion Rate heuristic removes at least 79% of the pheromones in the system, whereas the ACO algorithm renders statistically better results than other algorithmic counterparts from the literature

Transitioning young adults from paediatric to adult care and the HIV care continuum in Atlanta, Georgia, USA: a retrospective cohort study

Introduction: The transition from paediatric to adult HIV care is a particularly highâ risk time for disengagement among young adults; however, empirical data are lacking.Methods: We reviewed medical records of 72 youth seen in both the paediatric and the adult clinics of the Grady Infectious Disease Program in Atlanta, Georgia, USA, from 2004 to 2014. We abstracted clinical data on linkage, retention and virologic suppression from the last two years in the paediatric clinic through the first two years in the adult clinic.Results: Of patients with at least one visit scheduled in adult clinic, 97% were eventually seen by an adult provider (median time between last paediatric and first adult clinic visit = 10 months, interquartile range 2â 18 months). Half of the patients were enrolled in paediatric care immediately prior to transition, while the other half experienced a gap in paediatric care and reâ enrolled in the clinic as adults. A total of 89% of patients were retained (at least two visits at least three months apart) in the first year and 56% in the second year after transition. Patients who were seen in adult clinic within three months of their last paediatric visit were more likely to be virologically suppressed after transition than those who took longer (Relative risk (RR): 1.76; 95% confidence interval (CI): 1.07â 2.9; p = 0.03). Patients with virologic suppression (HIVâ 1 RNA below the level of detection of the assay) at the last paediatric visit were also more likely to be suppressed at the most recent adult visit (RR: 2.3; 95% CI: 1.34â 3.9; p = 0.002).Conclusions: Retention rates once in adult care, though high initially, declined significantly by the second year after transition. Preâ transition viral suppression and shorter linkage time between paediatric and adult clinic were associated with better outcomes postâ transition. Optimizing transition will require intensive transition support for patients who are not virologically controlled, as well as support for youth beyond the first year in the adult setting.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138343/1/jia21848.pd

SUMOylation of nuclear actin

Actin, a major component of the cytoplasm, is also abundant in the nucleus. Nuclear actin is involved in a variety of nuclear processes including transcription, chromatin remodeling, and intranuclear transport. Nevertheless, the regulation of nuclear actin by posttranslational modifications has not been investigated. We now show that nuclear actin is modified by SUMO2 and SUMO3 and that computational modeling and site-directed mutagenesis identified K68 and K284 as critical sites for SUMOylating actin. We also present a model for the actin–SUMO complex and show that SUMOylation is required for the nuclear localization of actin

Structural covariance predictors of clinical improvement at 2-year follow-up in first-episode psychosis

Background: Neural correlates of psychotic disorders encompass multiple brain regions in multiple brain circuits, even at early stages. Previous research has characterized structural brain alterations in ¿rst-episode psychosis (FEP), but few studies have focused on the relationship between brain alterations and disease trajectories. First psychotic episodes typically evolve into a chronic course, affecting quality of life of patients and their families, with huge societal costs. Importantly, up to 80% of the patients relapse in the next five years after a first psychotic episode, with a significant risk of developing treatment resistance. Here, we investigated whether disease course may be predicted from brain structural assessments. Specifically, we measured structural covariance, a well-established approach to identify abnormal patterns of volumetric correlation across distant brain regions, which allows to incorporate network-level information to structural assessments. We performed a whole-brain structural covariance assessment of three bilateral regions form to three different cortical networks - dorsolateral prefrontal cortex (dlPFC) for the executive network, posterior cingulate cortex for the default mode network and insulae for the salience network - and subcortical structures (hippocampi, amygdalae and dorsomedial nucleus of the thalamus) that have shown to play a key role in schizophrenia. Methods: We assessed a sample of 74 subjects from a multicenter, naturalistic, prospective and longitudinal study designed to evaluate clinical, neuropsychological, neuroimaging, biochemical, environmental and pharmacogenetic variables in first episode psychotic patients (PEPs project). Magnetic resonance imaging (MRI) scans were acquired at baseline and at 2-year follow-up, as well as clinical assessments. Psychotic symptoms were assessed using the Positive and Negative Symptom Scale (PANSS) due its widespread use in clinical studies and its reliability in assessing psychopathology across a range of patient populations. The sample was split in two groups as a function of the clinical improvement at 2-year follow-up: responders (i.e. 40% reduction in PANSS global score from baseline; n=29) and non-responders (n=45). Results: Responder patients showed increase structural covariance between the left dlPFC and the left middle frontal gyrus, and between the right dlPFC and the right middle and superior gyrus, the left rectus and inferior frontal gyrus, the right hippocampus, and the vermis of the cerebellum. In addition, they showed increased structural covariance between the left anterior hippocampus and the ipsilateral middle occipital gyrus and the contralateral postcentral gyrus. Likewise, the structural covariance of right anterior hippocampus with right superior occipital gyrus and precentral gyrus was also increased in responder patients. Discussion: This study shows, for the first time in the literature, that increased structural covariance at baseline within the executive network and between the hippocampi and posterior brain regions was associated with a superior treatment response at two-year follow-up. These results indicate that the integrity of structural networks should be taken into account to predict treatment outcome in FEP patients

Two-Way Quantum Time Transfer: A Method for Daytime Space-Earth Links

Remote clock synchronization is crucial for many classical and quantum network applications. Current state-of-the-art remote clock synchronization techniques achieve femtosecond-scale clock stability utilizing frequency combs, which are supplementary to quantum-networking hardware. Demonstrating an alternative, we synchronize two remote clocks across our freespace testbed using a method called two-way quantum time transfer (QTT). In one second we reach picosecond-scale timing precision under very lossy and noisy channel conditions representative of daytime space-Earth links with commercial off-the-shelf quantum-photon sources and detection equipment. This work demonstrates how QTT is potentially relevant for daytime space-Earth quantum networking and/or providing high-precision secure timing in GPS-denied environments.Comment: arXiv admin note: text overlap with arXiv:2211.0073

Análisis de la incorporación de la categoría vejez en la decimoprimera Clasificación Internacional de Enfermedades (CIE-11) desde una perspectiva demográfica y de derechos humanos

El artículo se escribió como parte de la Red de Envejecimiento de la Asociación Latinoamericana de Población ALAP.Este documento surge como respuesta a la iniciativa de la Red de Envejecimiento de la Asociación Latinoamericana de Población (ALAP), que, tal como diversas asociaciones de geriatría y gerontología en el mundo, está preocupada por las consecuencias negativas que puede llegar a producir la utilización del término vejez en la nueva CIE. Por esta razón, la Red de Envejecimiento encomendó a una comisión ad hoc que analizara la bibliografía actualizada del tema. Sobre la base de este proceso de estudio y reflexión, la comisión elaboró el presente artículo, que tiene como objetivo analizar los argumentos a favor y en contra de esta decisión, y las implicancias que esto conlleva para el conjunto de la sociedad, desde una perspectiva demográfica y de derechos humanos.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Centro Centroamericano de Población (CCP

Regulation of the Intestinal Extra-Adrenal Steroidogenic Pathway Component LRH-1 by Glucocorticoids in Ulcerative Colitis

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) and can be treated with glucocorticoids (GC), although some patients are unresponsive to this therapy. The transcription factor LRH-1/NR5A2 is critical to intestinal cortisol production (intestinal steroidogenesis), being reduced in UC patients. However, the relationship between LRH-1 expression and distribution with altered corticosteroid responses is unknown. To address this, we categorized UC patients by their steroid response. Here, we found that steroid-dependent and refractory patients presented reduced glucocorticoid receptor (GR)-mediated intestinal steroidogenesis compared to healthy individuals and responder patients, possibly related to increased colonic mucosa GR isoform beta (GR beta) content and cytoplasmic LRH-1 levels in epithelial and lamina propria cells. Interestingly, an intestinal epithelium-specific GR-induced knockout (GR(iKO)) dextran sodium sulfate (DSS)-colitis mice model presented decreased epithelial LRH-1 expression, whilst it increased in the lamina propria compared to DSS-treated control mice. Mechanistically, GR directly induced NR5A2 gene expression in CCD841CoN cells and human colonic organoids. Furthermore, GR bound to two glucocorticoid-response elements within the NR5A2 promoter in dexamethasone-stimulated CCD841CoN cells. We conclude that GR contributes to intestinal steroidogenesis by inducing LRH-1 in epithelial cells, suggesting LRH-1 as a potential marker for glucocorticoid-impaired response in UC. However, further studies with a larger patient cohort will be necessary to confirm role of LRH-1 as a therapeutic biomarker