The influence of nitrogen deficiency on microalgae-bacteria co-culture has been studied mostly with nitrogen-fixing bacteria. Photosynthetic bacteria (PSB), which are non-nitrogen-fixing bacteria, ...the impact of N deficiency on its co-culture with microalgae is unknown. In this study, Chlorella pyrenoidosa and Rhodobacter sphaeroides co-culture was cultivated photoheterotrophically with acetate. The impact of N starvation and different P supply levels on oil production were examined. When phosphorus was sufficient, N starvation increased the fatty acid methyl ester (FAME) content from 21.7 % to 28.2 %, and also increased the FAME yield (g CODFAME/g CODAcetate) from 0.17 to 0.22. However, the biomass and FAME productivities decreased. Sufficient phosphorus was also essential for a high growth rate and FAME productivity. Deficiencies in either N or P led to a decrease in the proportion of unsaturated FAMEs. iTRAQ analysis indicated N starvation promoted oil accumulation by driving the carbon flow to fatty acid synthesis in microalgae from co-culture. This study improves the understanding of biomass and lipid production via microalgae-PSB co-culture in photoheterotrophic cultivation. The mechanism of interaction between microalgae and bacteria needs further study.
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•N starvation enhanced the oil content and yield of microalgae-PSB co-culture.•Sufficient P was essential for a high growth rate and FAME productivity.•N starvation affected N and C metabolism in microalgae from co-culture.•N starvation drove the carbon flow to FA synthesis in microalgae from co-culture.
Imbalance between the production and clearance of amyloid-β (Aβ) promotes the development of Alzheimer's disease (AD). Presenilin-1 (PS1) is the catalytic subunit of γ-secretase, which is involved in ...the process of Aβ production. The profiles of autoantibodies are dysregulated in AD patients.
This study aims to investigate the relative levels and clinical relevance of naturally occurring antibodies to PS1 (NAbs-PS1) in AD.
A total of 55 subjects with AD (including both dementia and mild cognitive impairment due to AD), 28 subjects with cognitive impairment (including both dementia and mild cognitive impairment) not due to AD (non-AD CI), and 70 cognitively normal (CN) subjects were recruited. One-site ELISA was utilized to determine the relative levels of NAbs-PS1 in plasma.
AD subjects had lower plasma levels of NAbs-PS1 than CN and non-AD CI subjects. Plasma NAbs-PS1 were negatively associated with the brain Aβ load, as reflected by PET-PiB SUVR, and were positively associated with cognitive functions of participants. Plasma NAbs-PS1 discriminated AD patients from CN with an area under the curve (AUC) of 0.730, a sensitivity of 69.09%, and a specificity of 67.14%, and they discriminated AD patients from non-AD CI subjects with an AUC of 0.750, a specificity of 70.91%, and a sensitivity of 71.43%.
This study found an aberrant immunological phenotype in AD patients. Further investigations are needed to determine the pathophysiological functions of NAbs-PS1 in AD.
The global economy has been severely traumatized by the COVID-19 pandemic, and new ventures are under tremendous pressure to survive. This paper explores whether structured reading materials and ...mindfulness intervention can develop entrepreneurs' psychological capital and whether there are different effects on different development methods. We recruited 112 new venture entrepreneurs and carried out an online experiment using the experimental group, the control group, and the pre-test and post-test design; at last, 83 of whom participated in the process can be assessed for psychological capital development effect. The research findings indicated that structured reading materials could effectively improve the overall psychological capital of the subjects (
= -5.574，
< 0.01) and impact in every dimension, including self-efficacy (
= -2.858,
< 0.01), hope (
= -3.560,
< 0.01), resilience (
= -4.368,
< 0.01) and optimism (
= -3.300,
< 0.01). In comparison, mindfulness intervention can improve the subjects' overall psychological capital (
= -3.293,
< 0.01) and improve levels of self-efficacy (
= -2.285,
< 0.01), hope (
= -4.244,
< 0.01), resilience (
= -3.167,
< 0.01), but limited effect on the optimism (
= -1.955,
> 0.05); In addition, there is no significant difference between structured reading materials and mindfulness intervention according to the statistical analysis.
Fast Online EM for Big Topic Modeling Zeng, Jia; Liu, Zhi-Qiang; Cao, Xiao-Qin
IEEE transactions on knowledge and data engineering,
2016-March-1, 2016-3-1, 20160301, Volume:
28, Issue:
3
Journal Article
Peer reviewed
Open access
The expectation-maximization (EM) algorithm can compute the maximum-likelihood (ML) or maximum a posterior (MAP) point estimate of the mixture models or latent variable models such as latent ...Dirichlet allocation (LDA),which has been one of the most popular probabilistic topic modeling methods in the past decade. However, batch EM has high time and space complexities to learn big LDA models from big data streams. In this paper, we present a fast online EM (FOEM) algorithm that infers the topic distribution from the previously unseen documents incrementally with constant memory requirements. Within the stochastic approximation framework, we show that FOEM can converge to the local stationary point of the LDA's likelihood function. By dynamic scheduling for the fast speed and parameter streaming for the low memory usage, FOEM is more efficient for some lifelong topic modeling tasks than the state-of-the-art online LDA algorithms to handle both big data and big models (aka, big topic modeling) on just a PC.
Sepsis often causes organ dysfunction and is manifested in increased endothelial cell permeability in blood vessels. Early-stage inflammation is accompanied by metabolic changes, but it is unclear ...how the metabolic alterations in the endothelial cells following lipopolysaccharide (LPS) stimulation affect endothelial cell function. In this study, the effects of 1 μg/ml of LPS on the metabolism of human umbilical vein endothelial cells (HUVECs) were investigated, and the metabolic changes after LPS stimulation were explained from the perspective of mRNA expression, chromatin openness and metabolic flux. We found changes in the central metabolism of endothelial cells after LPS stimulation, such as enhanced glycolysis function, decreased mitochondrial membrane potential, and increased production of reactive oxygen species (ROS). Sphingolipid metabolic pathways change at the transcriptome level, and sphingosine-1-phosphatase 2 (SGPP2) was upregulated in LPS-stimulated endothelial cells and zebrafish models. Overexpression of SGPP2 improved cell barrier function, enhanced mitochondrial respiration capacity, but also produced oxidative respiration chain uncoupling. In addition, SGPP2 overexpression inhibited the degradation of HIF-1α protein. The molecular and biochemical processes identified in this study are not only beneficial for understanding the metabolic-related mechanisms of LPS-induced endothelial injury, but also for the discovery of general therapeutic targets for inflammation and inflammation-related diseases.
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•Warburg effect was produced in endothelial cells after LPS stimulation.•SGPP2 was up regulated in LPS induced HUVECs.•Overexpression of SGPP2 regulated mitochondrial respiration, reduced ROS, promoted cell proliferation and reduced cell permeability.•SGPP2 overexpression inhibited the degradation of HIF-1α.
To evaluate the interactions between polyfluoroalkyl substances (PFASs) and reproductive hormones and associated asthma, a total of 231 asthmatic and 225 non-asthmatic adolescents were selected from ...northern Taiwan in the Genetic and Biomarkers study for Childhood Asthma from 2009-2010. The interaction between PFASs and reproductive hormones on asthma was analyzed with a two-level binary logistic regression model. The results showed that, among asthmatics, PFASs were positively associated with estradiol levels and negatively associated with testosterone levels. However, only significant association was identified for PFNA and estradiol in control group. After controlling for hormone levels, associations between PFAS exposure and asthma were consistently stronger among children with higher than lower estradiol, with odds ratios (OR) for asthma ranging from 1.25 for PFOS (95% Confidence Interval CI: 0.90, 1.72) to 4.01 for PFDA (95% CI: 1.46, 11.06) among boys and 1.25 for PFOS (95% CI: 0.84, 1.86) to 4.16 for PFNA (95% CI: 1.36, 12.73) among girls. Notably, the interactions between estradiol and PFASs were significant for PFOS (p = 0.026) and PFNA (p = 0.043) among girls. However, testosterone significantly attenuated the association between PFOS and asthma across sex. In conclusions, our findings suggested that reproductive hormones amplify the association between PFASs and asthma among adolescents.
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•Two new crystal structures of copper porphyrins containing meso-tetra(ester and carboxyl) were obtained.•The two copper porphyrins were used to modify TiO2 for the first time.•The ...accumulated patterns of copper porphyrin molecules on the TiO2 surface is an important factor for the photocatalytic activity.•The peripheral groups of copper porphyrins influence their stacking patterns in solid state.
The accumulated patterns of porphyrin molecules on the surface of TiO2 have an important effect on the photoactivity of porphyrin/TiO2 photocatalysts. Herein, two copper porphyrins containing flexible peripheral functional groups (meso-tetra(ester, carboxy)), Cu(II)5,10,15,20-tetrakis4-(carboethoxymethyleneoxy)phenylporphyrin (CuPp(2a)) and Cu(II)5,10,15,20-tetrakis4-(carboxymethyleneoxy)phenylporphyrin (CuPp(2b)), were synthesized and characterized spectroscopically. Their crystal structures were also determined by single crystal X-ray diffraction. The Cu(II) porphyrinTiO2 composites were also prepared and characterized. The accumulated patterns of synthesized copper porphyrins on the surface of TiO2 were proposed for the first time. The photoactivity of the composites was investigated by carrying out the degradation of 4-nitrophenol (4-NP) in aqueous solution under UV–visible light. The results indicated that the CuPp(2b)TiO2 showed the higher photocatalytic activity than that of CuPp(2a)TiO2. Above all, it can be concluded that the accumulated patterns of porphyrins on the surface of TiO2 is an important factor for the photocatalytic efficiency of porphyrin/TiO2.
The spikelet is an inflorescence structure unique to grasses. The molecular mechanisms underlying spikelet development and evolution are unclear. In this study, we characterized three allelic ...recessive mutants in rice (
):
(
),
, and
In these mutants, organs such as the rudimentary glume, sterile lemma, palea, lodicule, and filament were elongated and/or widened, or transformed into lemma- and/or marginal region of the palea-like organs.
encoded a member of the C2H2 zinc finger protein family and was expressed mainly in the organ primordia of the spikelet. In the
mutant spikelet,
, and
were ectopically expressed in two or more organs, including the rudimentary glume, sterile lemma, palea, lodicule, and stamen, whereas
was downregulated in the rudimentary glume and sterile lemma. Furthermore, the NSG1 protein was able to bind to regulatory regions of
and then recruit the corepressor TOPLESS-RELATED PROTEIN to repress expression by downregulating histone acetylation levels of the chromatin. The results suggest that
plays a pivotal role in maintaining organ identities in the spikelet by repressing the expression of
,
, and
In Parkinson's disease (PD), reduced dopamine levels in the basal ganglia have been associated with altered neuronal firing and motor dysfunction. It remains unclear whether the altered firing rate ...or pattern of basal ganglia neurons leads to parkinsonism-associated motor dysfunction. In the present study, we show that increased histaminergic innervation of the entopeduncular nucleus (EPN) in the mouse model of PD leads to activation of EPN parvalbumin (PV) neurons projecting to the thalamic motor nucleus via hyperpolarization-activated cyclic nucleotide-gated (HCN) channels coupled to postsynaptic H
R. Simultaneously, this effect is negatively regulated by presynaptic H
R activation in subthalamic nucleus (STN) glutamatergic neurons projecting to the EPN. Notably, the activation of both types of receptors ameliorates parkinsonism-associated motor dysfunction. Pharmacological activation of H
R or genetic upregulation of HCN2 in EPN
neurons, which reduce neuronal burst firing, ameliorates parkinsonism-associated motor dysfunction independent of changes in the neuronal firing rate. In addition, optogenetic inhibition of EPN
neurons and pharmacological activation or genetic upregulation of H
R in EPN-projecting STN
neurons ameliorate parkinsonism-associated motor dysfunction by reducing the firing rate rather than altering the firing pattern of EPN
neurons. Thus, although a reduced firing rate and more regular firing pattern of EPN
neurons correlate with amelioration in parkinsonism-associated motor dysfunction, the firing pattern appears to be more critical in this context. These results also confirm that targeting H
R and its downstream HCN2 channel in EPN
neurons and H
R in EPN-projecting STN
neurons may represent potential therapeutic strategies for the clinical treatment of parkinsonism-associated motor dysfunction.
This paper deals with the problem of stability for aperiodically sampled-data control systems with constant communication delays. Less conservative results are derived by two main techniques. First, ...a new looped-functional-based Lyapunov function is proposed, which considers the information of intervals <inline-formula> <tex-math notation="LaTeX">x({t_{k}}) </tex-math></inline-formula> to <inline-formula> <tex-math notation="LaTeX">x(t) </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">x(t) </tex-math></inline-formula> to <inline-formula> <tex-math notation="LaTeX">x({t_{k + 1}}) </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">x(t_{k}-\tau) </tex-math></inline-formula> to <inline-formula> <tex-math notation="LaTeX">x(t-\tau) </tex-math></inline-formula>, and <inline-formula> <tex-math notation="LaTeX">x(t-\tau) </tex-math></inline-formula> to <inline-formula> <tex-math notation="LaTeX">x(t_{k+1}-\tau) </tex-math></inline-formula>. Second, in the derivative of the Lyapunov function, the integral term which has the information of sampling-period plus communication delay is divided into three parts. Then, by employing integral inequality techniques, some improved stability conditions are derived. The numerical examples demonstrate the validity of the proposed methods.
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