Abstract Weighted optimization framework (WOF) achieves variable dimensionality reduction by grouping variables and optimizing weights, playing an important role in large-scale multi-objective ...optimization problems. However, because of possible problems such as duplicate weight vectors in the selection process and loss of population diversity, the algorithm is susceptible to local optimization. Therefore, this paper develops an algorithm framework called multi-population multi-stage adaptive weighted optimization (MPSOF) to improve the performance of WOF in two aspects. First, the method of using multi-population is employed to address the issue of insufficient algorithmic diversity, while simultaneously reducing the likelihood of converging towards local optima. Secondly, a processing stage is incorporated into MPSOF, where a certain number of individuals are adaptively selected for updating based on the weight information and evolutionary status of different subpopulations, targeting different types of weights. This approach alleviates the impact of repetitive weights on the diversity of newly generated individuals, avoids the drawback of easily converging to local optima when using a single type of weight for updating, and effectively balances the diversity and convergence of subpopulations. Experiments of three types designed on several typical function sets demonstrate that MPSOF exceeds the comparison algorithms in the three metrics for Inverse Generation Distance, Hypervolume and Spacing.
The innate and adaptive branches of the immune system display changes with aging, a fact referred to as immunosenescence. Furthermore, it has been established that adaptive immunity is more ...susceptible to age-related changes than innate immunity. The most prominent phenotypic changes that reflect the specific differentiation and role of each T cell subpopulation are two-fold. They are a decreased number of naïve T cells that parallels an increase in memory T cells, mainly in the cytotoxic CD8+ T cell population, which can be subdivided into naïve, central, effector memory and TEMRA cells. The two main T cell properties that are the most affected with aging are the altered clonal expansion and decreased cytokine production, especially IL-2. These T cell functions have been shown to be affected in the early events of signaling. The aim of the present study was to investigate the influence of age on TCR- and CD28-dependent activation of the downstream signaling effectors Lck, SHP-1, Akt, PI3K p85α and mTOR in differentiated subpopulations of CD4+ and CD8+ T cells. Results showed that lymphocytes of elderly subjects were already in an activated state that could not be upregulated by external stimulation. Results also showed that the age-related signal transduction changes were more important than phenotype in the CD4+ and CD8+ T subpopulations. These observations suggested that age-related molecular and biochemical changes have a more significant influence on T cell functions than T cell phenotype.
•T lymphocytes of elderly subjects are already in an activated state.•Signal transduction changes are more related to age than to the phenotype in the CD4+ and CD8+ T subpopulations.•T cell subpopulations state of differentiation may support their specific role but not their functions with aging.
Cells release membrane enclosed nano-sized vesicles termed extracellular vesicles (EVs) that function as mediators of intercellular communication by transferring biological information between cells. ...Tumor-derived EVs have emerged as important mediators in cancer development and progression, mainly through transfer of their bioactive content which can include oncoproteins, oncogenes, chemokine receptors, as well as soluble factors, transcripts of proteins and miRNAs involved in angiogenesis or inflammation. This transfer has been shown to influence the metastatic behavior of primary tumors. Moreover, tumor-derived EVs have been shown to influence distant cellular niches, establishing favorable microenvironments that support growth of disseminated cancer cells upon their arrival at these pre-metastatic niches. It is generally accepted that cells release a number of major EV populations with distinct biophysical properties and biological functions. Exosomes, microvesicles, and apoptotic bodies are EV populations most widely studied and characterized. They are discriminated based primarily on their intracellular origin. However, increasing evidence suggests that even within these EV populations various subpopulations may exist. This heterogeneity introduces an extra level of complexity in the study of EV biology and function. For example, EV subpopulations could have unique roles in the intricate biological processes underlying cancer biology. Here, we discuss current knowledge regarding the role of subpopulations of EVs in cancer development and progression and highlight the relevance of EV heterogeneity. The position of tetraspanins and integrins therein will be highlighted. Since addressing EV heterogeneity has become essential for the EV field, current and novel techniques for isolating EV subpopulations will also be discussed. Further dissection of EV heterogeneity will advance our understanding of the critical roles of EVs in health and disease.
Aim
To collate prevalence estimates of fetal alcohol spectrum disorder (FASD) among special subpopulations (defined by service use).
Design
Systematic literature review and meta‐analysis of original, ...quantitative studies published between 1 November 1973 and 1 December 2018. The PRISMAGATHER were adhered to. The review protocol includes FASD prevalence in (a) general and (b) special populations is available on PROSPERO (registration number: CRD42016033837). Prevalence estimates were collated for all included studies with country‐, disorder‐ FASD and fetal alcohol syndrome (FAS) and population‐specific random‐effects meta‐analyses conducted.
Setting and Participants
A number of service‐defined subpopulations globally (see Findings).
Measurements
The main outcome was the prevalence of FASD among special subpopulations. The critical appraisal of each study was conducted using the Joanna Briggs Institute tool.
Findings
We identified 69 studies, comprising 6177 individuals diagnosed with FASD from 17 countries: Australia (n = 5), Brazil (n = 2), Canada (n = 15), Chile (n = 4), eastern Europe (Moldova, Romania and Ukraine; n = 1), Germany (n = 1), Israel (n = 1), Lithuania (n = 1), the Netherlands (n = 1), Poland (n = 1), Russia (n = 9), South Korea (n = 1), Spain (n = 1), Sweden (n = 1) and United States (n = 25). FAS and FASD prevalence rates were collated for the following five subpopulations: children in care, correctional, special education, specialized clinical and Aboriginal populations. The estimated prevalence of FASD in these special subpopulations was 10–40 times higher compared with the 7.7 per 1000 (95% confidence interval = 4.9–11.7) global FASD prevalence in the general population.
Conclusions
Global subpopulations of children in care, correctional, special education, specialized clinical and Aboriginal populations have a significantly higher prevalence of fetal alcohol spectrum disorder compared with the general population, which poses a substantial global health problem.
Background
HIV cure strategies aim to eliminate viral reservoirs that persist despite successful antiretroviral therapy (ART). We have previously described that 9% of HIV‐infected individuals who ...receive ART harbor low levels of provirus (LoViReTs).
Methods
We selected 22 LoViReTs matched with 22 controls ART suppressed for more than 3 years with fewer than 100 and more than 100 HIV‐DNA copies/106 CD4+ T cells, respectively. We measured HIV reservoirs in blood and host genetic factors. Fourteen LoViReTs underwent leukapheresis to analyze replication‐competent virus, and HIV‐DNA in CD4+ T‐cell subpopulations. Additionally, we measured HIV‐DNA in rectum and/or lymph node biopsies from nine of them.
Results
We found that LoViReTs harbored not only lower levels of total HIV‐DNA, but also significantly lower intact HIV‐DNA, cell‐associated HIV‐RNA, and ultrasensitive viral load than controls. The proportion of intact versus total proviruses was similar in both groups. We found no differences in the percentage of host factors. In peripheral blood, 71% of LoViReTs had undetectable replication‐competent virus. Minimum levels of total HIV‐DNA were found in rectal and lymph node biopsies compared with HIV‐infected individuals receiving ART. The main contributors to the reservoir were short‐lived transitional memory and effector memory T cells (47% and 29%, respectively), indicating an altered distribution of the HIV reservoir in the peripheral T‐cell subpopulations of LoViReTs.
Conclusion
In conclusion, LoViReTs are characterized by low levels of viral reservoir in peripheral blood and secondary lymphoid tissues, which might be explained by an altered distribution of the proviral HIV‐DNA towards more short‐lived memory T cells. LoViReTs can be considered exceptional candidates for future interventions aimed at curing HIV.
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