28 research outputs found
Distributed Stochastic Subgradient Optimization Algorithms Over Random and Noisy Networks
We study distributed stochastic optimization by networked nodes to
cooperatively minimize a sum of convex cost functions. The network is modeled
by a sequence of time-varying random digraphs with each node representing a
local optimizer and each edge representing a communication link. We consider
the distributed subgradient optimization algorithm with noisy measurements of
local cost functions' subgradients, additive and multiplicative noises among
information exchanging between each pair of nodes. By stochastic Lyapunov
method, convex analysis, algebraic graph theory and martingale convergence
theory, it is proved that if the local subgradient functions grow linearly and
the sequence of digraphs is conditionally balanced and uniformly conditionally
jointly connected, then proper algorithm step sizes can be designed so that all
nodes' states converge to the global optimal solution almost surely
Brain Structural Alterations in Left-Behind Children: A Magnetic Resonance Imaging Study
Parental migration has caused millions of children left behind, especially in China and India. Left-behind children (LBC) have a high risk of mental disorders and may present negative life outcomes in the future. However, little is known whether there are cerebral structural alterations in LBC in relative to those with parents. This study is to explore the effect of parental migration on brain maturation by comparing gray matter volume (GMV) and fractional anisotropy (FA) of LBC with well-matched non-LBC. Thirty-eight LBC (21 boys, age = 9.60 ± 1.8 years) and 30 non-LBC (19 boys, age = 10.00 ± 1.95 years) were recruited and underwent brain scans in 3.0 T MR. Intelligence quotient and other factors including family income, guardians’ educational level and separation time were also acquired. GMV and FA were measured for each participant and compared between groups using 2-sample t-tests with atlas-based analysis. Compared to non-LBC, LBC exhibited greater GMV in emotional and cortico-striato-thalamo-cortical circuits, and altered FA in bilateral superior occipitofrontal fasciculi and right medial lemniscus (p < 0.05, Cohen’s d > 0.89, corrected for false-discovery rate). Other factors including family income, guardians’ educational level and separation time were not associated with these brain changes. Our study provides empirical evidence of altered brain structure in LBC compared to non-LBC, responsible for emotion regulation and processing, which may account for mental disorders and negative life outcome of LBC. Our study suggests that absence of direct biological parental care may impact children’s brain development. Therefore, public health efforts may be needed to provide additional academic and social/emotional supports to LBC when their parents migrate to seeking better economic circumstances, which has become increasingly common in developing countries
Initiation of the Hypothalamic–Pituitary–Gonadal Axis in Young Girls Undergoing Central Precocious Puberty Exerts Remodeling Effects on the Prefrontal Cortex
Central precocious puberty (CPP) has been shown to exert significant effects on psychosocial development. These early puberty-related hormones and psychosocial functional changes are considered to be associated with specific brain development. However, the biological mechanisms underlying the sculpting of human brain architecture and modulation of psychosocial transformation by puberty-related hormonal maturation remain elusive, especially during the early phase of CPP. The current investigation aims to specify the brain regions in which early hormone-related maturation effects occur during CPP and their relationships with psychological functions. 65 young girls (aged 4.3–8.0 years) underwent structural imaging on a 3T MR system, completed psychological tests and performed the gonadotropin-releasing hormone (GnRH) stimulation test to identify hormonal manifestations of hypothalamic–pituitary–gonadal axis (HPG axis) activation. Based on the GnRH test, 28 young girls were identified with CPP, whereas the other 37 girls were identified with non-central precocious puberty (NCPP). Cortical parameters were calculated and compared between the two groups after adjusting for age, weight, and height. Brain regions showing group differences were extracted and correlated with serum hormone levels and psychological parameters. The CPP girls showed thinner cortices primarily in the right rostral middle frontal cortex. This morphological difference was positively correlated with stimulated estradiol (E2) levels. Further, higher E2 levels were significantly associated with higher hyperactivity scores. Premature HPG axis activation in CPP girls at an early stage appears to exert remodeling effects on brain anatomy, primarily in the prefrontal cortex, which may affect psychological development following the emergence of robust changes in sex hormones
Decentralized Online Regularized Learning Over Random Time-Varying Graphs
We study the decentralized online regularized linear regression algorithm
over random time-varying graphs. At each time step, every node runs an online
estimation algorithm consisting of an innovation term processing its own new
measurement, a consensus term taking a weighted sum of estimations of its own
and its neighbors with additive and multiplicative communication noises and a
regularization term preventing over-fitting. It is not required that the
regression matrices and graphs satisfy special statistical assumptions such as
mutual independence, spatio-temporal independence or stationarity. We develop
the nonnegative supermartingale inequality of the estimation error, and prove
that the estimations of all nodes converge to the unknown true parameter vector
almost surely if the algorithm gains, graphs and regression matrices jointly
satisfy the sample path spatio-temporal persistence of excitation condition.
Especially, this condition holds by choosing appropriate algorithm gains if the
graphs are uniformly conditionally jointly connected and conditionally
balanced, and the regression models of all nodes are uniformly conditionally
spatio-temporally jointly observable, under which the algorithm converges in
mean square and almost surely. In addition, we prove that the regret upper
bound , where is a constant
depending on the algorithm gains
Feasibility investigation of using waste laminated packaging as bitumen performance enhancer
Millions of tons of laminated packaging are extensively utilized in aseptic food packaging due to its advantages in transporting and storing liquid foods, leading to the annual generation of waste laminated packaging (WLP). To address this concern, this study processes WLP recycled from milk and fruit juice packages into particles. The properties of WLP-modified bitumen were characterized through conventional and rheological tests, and the results were compared with those of the base bitumen. The tests reveal that the addition of WLP increases the softening point and peak force while decreasing penetration and ductility. Additionally, higher WLP content results in a larger modification index, higher failure temperature, lower non-recoverable creep compliance, and lower stress sensitivity. Furthermore, the stabilizing effect of low-density polyethylene in WLP, combined with the complete cross-linking of cellulose fibers, contributes to enhancing the fatigue life of the bitumen
DataSheet_1_Microdiversity sustains the distribution of rhizosphere-associated bacterial species from the root surface to the bulk soil region in maize crop fields.docx
Over the years, the microbial community of maize (Zea mays) rhizosphere has been extensively studied; however, the role of microdiversity sustain rhizosphere-associated microbial species distribution from root surface to bulk soil in mature maize is still unclear. Although operational taxonomic units (OTUs) have been used to classify species, amplicon sequence variants (ASVs) have been shown to be effective in representing microdiversity within OTUs at a finer genetic scale. Therefore, the aim of this study was to examine the role of microdiversity in influencing the distribution of rhizosphere-associated microbial species across environmental gradients from root surface to bulk soil at the OTU and ASV levels. Here, the microbial community structures of bulk, loosely bound, and tightly bound soil samples from maize rhizosphere were examined at OTU and ASV levels. The results showed that OTU and ASV methods exhibited similar microbial community structures in rhizosphere. Additionally, different ecotypes with varying distributions and habitat preferences were observed within the same bacterial OTU at the ASV level, indicating a rich bacterial microdiversity. In contrast, the fungal community exhibited low microdiversity, with no significant relationship between fungal microdiversity and persistence and variability. Moreover, the ecotypes observed within the bacterial OTUs were found to be positively or negatively associated with environmental factors, such as soil organic carbon (SOC), NO3−–N, NH4+–N contents, and pH. Overall, the results showed that the rich microdiversity could sustain the distribution of rhizosphere-associated bacterial species across environmental gradients from root surface to bulk soil. Further genetic analyses of rhizosphere-associated bacterial species could have considerable implications for potential mediation of microdiversity for sustainable crop production.</p
DataSheet_2_Microdiversity sustains the distribution of rhizosphere-associated bacterial species from the root surface to the bulk soil region in maize crop fields.xlsx
Over the years, the microbial community of maize (Zea mays) rhizosphere has been extensively studied; however, the role of microdiversity sustain rhizosphere-associated microbial species distribution from root surface to bulk soil in mature maize is still unclear. Although operational taxonomic units (OTUs) have been used to classify species, amplicon sequence variants (ASVs) have been shown to be effective in representing microdiversity within OTUs at a finer genetic scale. Therefore, the aim of this study was to examine the role of microdiversity in influencing the distribution of rhizosphere-associated microbial species across environmental gradients from root surface to bulk soil at the OTU and ASV levels. Here, the microbial community structures of bulk, loosely bound, and tightly bound soil samples from maize rhizosphere were examined at OTU and ASV levels. The results showed that OTU and ASV methods exhibited similar microbial community structures in rhizosphere. Additionally, different ecotypes with varying distributions and habitat preferences were observed within the same bacterial OTU at the ASV level, indicating a rich bacterial microdiversity. In contrast, the fungal community exhibited low microdiversity, with no significant relationship between fungal microdiversity and persistence and variability. Moreover, the ecotypes observed within the bacterial OTUs were found to be positively or negatively associated with environmental factors, such as soil organic carbon (SOC), NO3−–N, NH4+–N contents, and pH. Overall, the results showed that the rich microdiversity could sustain the distribution of rhizosphere-associated bacterial species across environmental gradients from root surface to bulk soil. Further genetic analyses of rhizosphere-associated bacterial species could have considerable implications for potential mediation of microdiversity for sustainable crop production.</p
DataSheet_3_Microdiversity sustains the distribution of rhizosphere-associated bacterial species from the root surface to the bulk soil region in maize crop fields.xlsx
Over the years, the microbial community of maize (Zea mays) rhizosphere has been extensively studied; however, the role of microdiversity sustain rhizosphere-associated microbial species distribution from root surface to bulk soil in mature maize is still unclear. Although operational taxonomic units (OTUs) have been used to classify species, amplicon sequence variants (ASVs) have been shown to be effective in representing microdiversity within OTUs at a finer genetic scale. Therefore, the aim of this study was to examine the role of microdiversity in influencing the distribution of rhizosphere-associated microbial species across environmental gradients from root surface to bulk soil at the OTU and ASV levels. Here, the microbial community structures of bulk, loosely bound, and tightly bound soil samples from maize rhizosphere were examined at OTU and ASV levels. The results showed that OTU and ASV methods exhibited similar microbial community structures in rhizosphere. Additionally, different ecotypes with varying distributions and habitat preferences were observed within the same bacterial OTU at the ASV level, indicating a rich bacterial microdiversity. In contrast, the fungal community exhibited low microdiversity, with no significant relationship between fungal microdiversity and persistence and variability. Moreover, the ecotypes observed within the bacterial OTUs were found to be positively or negatively associated with environmental factors, such as soil organic carbon (SOC), NO3−–N, NH4+–N contents, and pH. Overall, the results showed that the rich microdiversity could sustain the distribution of rhizosphere-associated bacterial species across environmental gradients from root surface to bulk soil. Further genetic analyses of rhizosphere-associated bacterial species could have considerable implications for potential mediation of microdiversity for sustainable crop production.</p
The Current Immunohistochemistry Markers in the Resected Tissues of Non-small Cell Lung Cancer Could Not Predict Prognosis
Background and objective It has been drawn much attention to identify the molecular markers by immunohistochemistry (IHC) for evaluating the prognosis of non-small cell lung cancer (NSCLC) following resection. The aim of this study is to retrospectively associate ever tested IHC markers and prognosis of NSCLC after resection. Methods A total of 722 NSCLC patients underwent surgery by single surgeon team from 2008 to 2013. Twelve molecular markers had been examined by IHC and the staining signals was re-scored with unified standard. Survival analysis by univariate and multivariate was carried out to assess the significance of these markers in prognosis of NSCLC in our prospective database with strict follow-up. Results The following twelve IHC markers had been tested between 2008 and 2013, including platelet-derived growth factor receptor (PDGFR)(n=124), excision repair cross complementing 1 (ERCC1)(n=124), epithelial growth factor receptor (EGFR)(n=131), vascular endothelial growth factor receptor 3 (VEGFR3)(n=142), NM23 (n=129), MRP (n=109), P170 (n=104), TS (n=143), Tubulin (n=133), ribonucleotide reductase M1 (RRM1)(n=131), ribonucleotide reductase M1 (COX2)(n=138), and TOPII (n=127). Only VEGFR3 expression was correlated with prognosis of the patients by univariate analysis, with 5-yrs survival rate being 77.6% and 65.0% (positive vs. negative) respectively (P=0.042). However, VEGFR3 was not an independent prognostic factor for this series of NSCLC patients in multivariate analysis. Conclusion These twelve IHC markers could not predict prognosis of NSCLC patients after surgery in our series
Alterations in Cortical Thickness and White Matter Integrity in Mild-to-Moderate Communicating Hydrocephalic School-Aged Children Measured by Whole-Brain Cortical Thickness Mapping and DTI
Follow-up observation is required for mild-to-moderate hydrocephalic patients because of the potential damage to brain. However, effects of mild-to-moderate hydrocephalus on gray and white matter remain unclear in vivo. Using structural MRI and diffusion tensor imaging (DTI), current study compared the cortical thickness and white matter integrity between children with mild-to-moderate communicating hydrocephalus and healthy controls. The relationships between cortical changes and intelligence quota were also examined in patients. We found that cortical thickness in the left middle temporal and left rostral middle frontal gyrus was significantly lower in the hydrocephalus group compared with that of controls. Fractional anisotropy in the right corpus callosum body was significantly lower in the hydrocephalus group compared with that of controls. In addition, there was no association of cortical thinning or white matter fractional anisotropy with intelligence quota in either group. Thus, our findings provide clues to that mild-to-moderate hydrocephalus could lead to structural brain deficits especially in the middle temporal and middle frontal gyrus prior to the behavior changes