scholarly journals Estuarine gradients dictate spatiotemporal variations of microbiome networks in the Chesapeake Bay

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Hualong Wang ◽  
Feng Chen ◽  
Chuanlun Zhang ◽  
Min Wang ◽  
Jinjun Kan
Keyword(s):  
Chesapeake Bay ◽  
Structural Equation ◽  
Environmental Gradients ◽  
Seasonal Pattern ◽  
Temporal Variations ◽  
Equation Modeling ◽  
Spatiotemporal Variations ◽  
Particulate Carbon ◽  
Estuarine Ecosystem ◽  
Estuarine Gradients

Abstract Background Annually reoccurring microbial populations with strong spatial and temporal variations have been identified in estuarine environments, especially in those with long residence time such as the Chesapeake Bay (CB). However, it is unclear how microbial taxa cooccurr and how the inter-taxa networks respond to the strong environmental gradients in the estuaries. Results Here, we constructed co-occurrence networks on prokaryotic microbial communities in the CB, which included seasonal samples from seven spatial stations along the salinity gradients for three consecutive years. Our results showed that spatiotemporal variations of planktonic microbiomes promoted differentiations of the characteristics and stability of prokaryotic microbial networks in the CB estuary. Prokaryotic microbial networks exhibited a clear seasonal pattern where microbes were more closely connected during warm season compared to the associations during cold season. In addition, microbial networks were more stable in the lower Bay (ocean side) than those in the upper Bay (freshwater side). Multivariate regression tree (MRT) analysis and piecewise structural equation modeling (SEM) indicated that temperature, salinity and total suspended substances along with nutrient availability, particulate carbon and Chl a, affected the distribution and co-occurrence of microbial groups, such as Actinobacteria, Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia. Interestingly, compared to the abundant groups (such as SAR11, Saprospiraceae and Actinomarinaceae), the rare taxa including OM60 (NOR5) clade (Gammaproteobacteria), Micrococcales (Actinobacteria), and NS11-12 marine group (Bacteroidetes) contributed greatly to the stability of microbial co-occurrence in the Bay. Modularity and cluster structures of microbial networks varied spatiotemporally, which provided valuable insights into the ‘small world’ (a group of more interconnected species), network stability, and habitat partitioning/preferences. Conclusion Our results shed light on how estuarine gradients alter the spatiotemporal variations of prokaryotic microbial networks in the estuarine ecosystem, as well as their adaptability to environmental disturbances and co-occurrence network complexity and stability.

scholarly journals Estuarine Gradients Dictate Spatiotemporal Variations of Microbiome Networks in the Chesapeake Bay

2021 ◽  
Author(s):  
Hualong Wang ◽  
Feng Chen ◽  
Chuanlun Zhang ◽  
Min Wang ◽  
Jinjun Kan
Keyword(s):  
Chesapeake Bay ◽  
Structural Equation ◽  
Environmental Gradients ◽  
Seasonal Pattern ◽  
Temporal Variations ◽  
Equation Modeling ◽  
Spatiotemporal Variations ◽  
Particulate Carbon ◽  
Estuarine Ecosystem ◽  
Estuarine Gradients

Abstract Background: Annually reoccurring microbial populations with strong spatial and temporal variations have been identified in estuarine environments, especially in those with long residence time such as the Chesapeake Bay (CB). However, it is unclear how microbial taxa cooccurrence with each other and how the inter-taxa networks respond to the strong environmental gradients in the estuaries. Results: Here, we constructed co-occurrence networks on prokaryotic microbial communities in the CB, which included seasonal samples from seven spatial stations along the salinity gradients for three consecutive years. Our results showed that spatiotemporal variations of planktonic microbiomes promoted differentiations of the characteristics and stability of prokaryotic microbial networks in the CB estuary. Prokaryotic microbial networks exhibited a clear seasonal pattern where microbes were more closely connected during warm season compared to the associations during cold season. In addition, microbial networks were more stable in the lower Bay (ocean side) than those in the upper Bay (freshwater side). Multivariate regression tree (MRT) analysis and piecewise structural equation modeling (SEM) indicated that temperature, salinity and total suspended substances along with nutrient availability, particulate carbon and Chl a, affected the distribution and co-occurrence of microbial groups, such as Actinobacteria, Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia. Interestingly, compared to the abundant groups (such as SAR11, Saprospiraceae and Actinomarinaceae), the rare taxa including OM60(NOR5) clade (Gammaproteobacteria), Micrococcales (Actinobacteria), and NS11-12 marine group (Bacteroidetes) contributed greatly to the stability of microbial co-occurrence in the Bay. Modularity and cluster structures of microbial networks varied spatiotemporally, which provided valuable insights into the ‘small world’ (a group of more interconnected species), network stability, and habitat partitioning/preferences.Conclusion: Our results shed light on how estuarine gradients alter the spatiotemporal variations of prokaryotic microbial networks in the estuarine ecosystem, as well as their adaptability to environmental disturbances and co-occurrence network complexity and stability.

scholarly journals Spatiotemporal Variations Dictate Stable and Resilient Microbiome Interactions in the Chesapeake Bay

2020 ◽  
Author(s):  
Hualong Wang ◽  
Feng Chen ◽  
Chuanlun Zhang ◽  
Min Wang ◽  
Jinjun Kan
Keyword(s):  
Chesapeake Bay ◽  
Structural Equation ◽  
Regression Tree ◽  
Warm Season ◽  
Temporal Variations ◽  
Microbial Interactions ◽  
Equation Modeling ◽  
Spatiotemporal Variations ◽  
Particulate Carbon ◽  
Estuarine Ecosystem

Abstract Background: Annually reoccurring microbial populations with strong spatial and temporal variations have been identified in estuarine environments, especially in those with long residence time such as the Chesapeake Bay (CB). However, it is unclear how microbial taxa interact with each other (e.g., mutualistic and competitive interactions) and how these interactions respond to their surrounding environments. Specifically, there is a lack of understanding of how these interactions influence microbiome population dynamics, and its adaptability and resilience to estuarine gradients. Results: Here, we constructed co-occurrence networks on prokaryotic microbial communities in the Bay, which included seasonal samples from seven spatial stations along the salinity gradients for three consecutive years. Our results showed that spatiotemporal variations of planktonic microbiomes promoted differentiations of the characteristics and stability of prokaryotic microbial networks in the CB estuary. Prokaryotic microbial networks are more stable seasonally than spatially, and microbes were more strongly connected during warm season compared to the associations during cold season. In addition, microbial interactions were more stable in the lower Bay (ocean side) than those in the upper Bay (freshwater side). Interestingly, compared to the abundant groups, the rare taxa such as SAR116 clade, SAR11 clade III, and OM182 clade contributed greatly to the stability and resilience of prokaryotic microbial interactions in the Bay. Modularity and cluster structures of microbial networks varied spatiotemporally, which provided valuable insights into the ‘small world’ (a group of more interconnected species), network stability, and habitat partitioning/preferences. Multivariate regression tree (MRT) analysis and Piecewise structural equation modeling (SEM) indicated that temperature, salinity and total suspended substances directly or indirectly (through nutrient availability, particulate carbon and Chl a) affected the distribution and associations of microbial groups, such as Actinobacteria, Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia.Conclusion: Our results shed light on how spatiotemporal variations alter the nature and stability of prokaryotic microbial networks in the estuarine ecosystem, as well as the ability of planktonic microbiomes and their interactions to resist future disturbances.

scholarly journals Indirect drivers of plant diversity-productivity relationship in semiarid sandy grasslands

2012 ◽  
Vol 9 (4) ◽  
pp. 1277-1289 ◽  
Author(s):  
X. A. Zuo ◽  
J. M. H. Knops ◽  
X. Y. Zhao ◽  
H. L. Zhao ◽  
T. H. Zhang ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Plant Diversity ◽  
Structural Equation ◽  
Environmental Gradients ◽  
Northern China ◽  
Equation Modeling ◽  
Vegetation Composition ◽  
Wet Meadow ◽  
Positive Correlation ◽  
Sandy Grasslands

Abstract. Although patterns between plant diversity and ecosystem productivity have been much studied, a consistent relationship has not yet emerged. Differing patterns between plant diversity and productivity have been observed in response to spatial variability of environmental factors and vegetation composition. In this study, we measured vegetation cover, plant diversity, productivity, soil properties and site characteristics along an environmental gradient (mobile dune, semi-fixed dune, fixed dune, dry meadow, wet meadow and flood plain grasslands) of natural sandy grasslands in semiarid areas of northern China. We used multivariate analysis to examine the relationships between environmental factors, vegetation composition, plant diversity and productivity. We found a positive correlation between plant diversity and productivity. Vegetation composition aggregated by the ordination technique of non-metric multidimensional scaling had also a significantly positive correlation with plant diversity and productivity. Environmental gradients in relation to soil and topography affected the distribution patterns of vegetation composition, species diversity and productivity. However, environmental gradients were a better determinant of vegetation composition and productivity than of plant diversity. Structural equation modeling suggested that environmental factors determine vegetation composition, which in turn independently drives both plant diversity and productivity. Thus, the positive correlation between plant diversity and productivity is indirectly driven by vegetation composition, which is determined by environmental gradients in soil and topography.

scholarly journals Abundance and Distribution of Synechococcus spp. and Cyanophages in the Chesapeake Bay

2011 ◽  
Vol 77 (21) ◽  
pp. 7459-7468 ◽  
Author(s):  
Kui Wang ◽  
K. Eric Wommack ◽  
Feng Chen
Keyword(s):  
Chesapeake Bay ◽  
Environmental Gradients ◽  
Salinity Gradient ◽  
Most Probable Number ◽  
Estuarine Ecosystem ◽  
Probable Number ◽  
Content Type ◽  
Carbon Pump ◽  
Host Mortality ◽  
Host Virus Interactions

ABSTRACTDespite the increasing knowledge ofSynechococcusspp. and their co-occurring cyanophages in oceanic and coastal water, little is known about their abundance, distribution, and interactions in the Chesapeake Bay estuarine ecosystem. A 5-year interannual survey shows thatSynechococcusspp. and their phages are persistent and abundant members of Chesapeake Bay microbial communities.Synechococcusblooms (106cells ml−1) were often observed in summer throughout the Bay, contributing 20 to 40% of total phytoplankton chlorophylla. The distribution of phycoerythrin-containing (PE-rich)Synechococcuscells appeared to mostly correlate with the salinity gradient, with higher abundances at higher salinities. Cyanophages infectious toSynechococcuswere also abundant (up to 6 × 105viruses ml−1by the most probable number assay) during summer months in the Bay. The covariation in abundance ofSynechococcusspp. and cyanophages was evident, although the latitude of observed positive correlation varied in different years, mirroring the changing environmental conditions and therefore the host-virus interactions. The impacts of cyanophages on hostSynechococcuspopulations also varied spatially and temporally. Higher phage-relatedSynechococcusmortality was observed in drought years. Virus-mediated host mortality and subsequent liberation of dissolved organic matter (DOM) may substantially influence oceanic biogeochemical processing through the microbial loop as well as the microbial carbon pump. These observations emphasize the influence of environmental gradients on naturalSynechococcusspp. and their phage population dynamics in the estuarine ecosystem.

A Psychometric Study of the Quality Perception Questionnaire

2012 ◽  
Vol 71 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Raffaele Cioffi† ◽  
Anna Coluccia ◽  
Fabio Ferretti ◽  
Francesca Lorini ◽  
Aristide Saggino ◽  
...  
Keyword(s):  
Structural Equation ◽  
Factor Model ◽  
Equation Modeling ◽  
Fit Indices ◽  
Quality Perception ◽  
Italian Survey ◽  
Confirmatory Factor ◽  
Instrument Measuring ◽  
Hospital Structures

The present paper reexamines the psychometric properties of the Quality Perception Questionnaire (QPQ), an Italian survey instrument measuring patients’ perceptions of the quality of a recent hospital admission experience, in a sample of 4400 patients (Mage = 56.42 years; SD = 19.71 years, 48.8% females). The 14-item survey measures four factors: satisfaction with medical doctors, nursing staff, auxiliary staff, and hospital structures. First, we tested two models using a confirmatory factor analysis (structural equation modeling): a four orthogonal factor and a four oblique factor model. The SEM fit indices and the χ² difference suggested the acceptance of the second model. We then did a simulation using a bootstrap with 1000 replications. Results confirmed the four oblique factor solution. Third, we tested whether there were significant differences with respect to age or sex. The multivariate general linear model showed no significant differences in the factors with respect to sex or age.

Suicide Risk Among College Student

Crisis ◽  
2015 ◽  
Vol 36 (6) ◽  
pp. 416-423 ◽  
Author(s):  
Richard Shadick ◽  
Faedra Backus Dagirmanjian ◽  
Baptiste Barbot
Keyword(s):  
Sexual Minority ◽  
Students Of Color ◽  
Structural Equation ◽  
Suicide Risk ◽  
Equation Modeling ◽  
First Year ◽  
Chi Square ◽  
First Year College ◽  
Marginalized Groups ◽  
First Year College Students

Abstract. Background: Research on young adults in the general population has identified a relationship between sexual minority identification and risk for suicide. Differential rates of suicidal ideation and attempts have also been found across racial and ethnic groups. Aims: This study examined risk for suicide among university students, based on membership in one or more marginalized groups (sexual minority and racial minority identification). Method: Data were collected from first-year college students (N = 4,345) at an urban university. Structural equation modeling was employed to model a suicidality construct, based on which a "risk for suicide" category system was derived. Chi-square and logistic regression analyses were then conducted to estimate the relationship between the background variables of interest and suicide risk. Results: Students who identified as lesbian, gay, or bisexual (LGB) were associated with higher suicide risk than their heterosexual peers. Students of color were slightly less at risk than their heterosexual peers. However, LGB students of color were associated with elevated suicide risk relative to heterosexual peers. Conclusion: Results indicate that belonging to multiple marginalized groups may increase one's risk for suicide, though these effects are not simply additive. Findings highlight the complexity of the intersection between marginalized identities and suicidality.

Low Self-Control of Emotions as an Antecedent of Self-Reported Physical Symptoms: A Longitudinal Perspective

2001 ◽  
Vol 6 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Marja Kokkonen ◽  
Lea Pulkkinen ◽  
Taru Kinnunen
Keyword(s):  
Structural Equation ◽  
Negative Emotions ◽  
Physical Symptoms ◽  
Self Control ◽  
Personality Characteristics ◽  
Equation Modeling ◽  
Eysenck Personality Questionnaire ◽  
Positive Direction ◽  
Data Collections ◽  
Low Self Control

The study was part of the Jyväskylä Longitudinal Study of Personality and Social Development, underway since 1968, in which children's low self-control of emotions was studied using teacher ratings at age 8 in terms of inattentiveness, shifting moods, aggression, and anxiety. The study was based on data from 112 women and 112 men who participated in the previous data collections at ages 8, 27, and 36. At age 27, the participants had been assessed in Neuroticism (N) using the Eysenck Personality Questionnaire , and at age 36 they filled in several inventories measuring, among others, conscious and active attempts to repair negative emotions in a more positive direction as well as physical symptoms. The present study used structural equation modeling to test the hypothesis that personality characteristics indicating low self-control of emotions at ages 8 and 27 are antecedents of self-reported physical symptoms at age 36; and that this relationship is indirect, mediated by attempts to repair negative emotions in a more positive direction. The findings showed, albeit for men only, that inattentiveness at age 8 was positively related to self-reported physical symptoms at age 36 via high N at age 27 and low attempts to repair negative emotions at age 36. Additionally, N at age 27 was directly linked to self-reported physical symptoms at age 36. The mediation of an active attempt to repair negative emotions was not found for women. Correlations revealed, however, that shifting moods and aggression in girls were antecedents of self-reported physical symptoms in adulthood, particularly, pain and fatigue.

Validating the Factor Structure of the Stigma of Suicide Scale–Short Form Spanish Version Among Healthcare Students

Crisis ◽  
2020 ◽  
pp. 1-5
Author(s):  
Ruthmarie Hernández-Torres ◽  
Paola Carminelli-Corretjer ◽  
Nelmit Tollinchi-Natali ◽  
Ernesto Rosario-Hernández ◽  
Yovanska Duarté-Vélez ◽  
...  
Keyword(s):  
Factor Structure ◽  
Structural Equation ◽  
Short Form ◽  
Small Sample Size ◽  
Small Sample ◽  
Spanish Version ◽  
Equation Modeling ◽  
Cross Sectional ◽  
Healthcare Students ◽  
Spanish Speaking

Abstract. Background: Suicide is a leading cause of death among Spanish-speaking individuals. Suicide stigma can be a risk factor for suicide. A widely used measure is the Stigma of Suicide Scale-Short Form (SOSS-SF; Batterham, Calear, & Christensen, 2013 ). Although the SOSS-SF has established psychometric properties and factor structure in other languages and cultural contexts, no evidence is available from Spanish-speaking populations. Aim: This study aims to validate a Spanish translation of the SOSS-SF among a sample of Spanish-speaking healthcare students ( N = 277). Method: We implemented a cross-sectional design with quantitative techniques. Results: Following a structural equation modeling approach, a confirmatory factor analysis (CFA) supported the three-factor model proposed by Batterham and colleagues (2013) . Limitations: The study was limited by the small sample size and recruitment by availability. Conclusion: Findings suggest that the Spanish version of the SOSS-SF is a valid and reliable tool with which to examine suicide stigma among Spanish-speaking populations.

Risk Factors and Mediators of Suicidal Ideation Among Korean Adolescents

Crisis ◽  
2018 ◽  
Vol 39 (1) ◽  
pp. 4-12 ◽  
Author(s):  
Yi Jin Kim ◽  
Sung Seek Moon ◽  
Jang Hyun Lee ◽  
Joon Kyung Kim
Keyword(s):  
High School Students ◽  
Suicidal Ideation ◽  
Structural Equation ◽  
Equation Modeling ◽  
Outcome Variable ◽  
Suicidal Behaviors ◽  
Thwarted Belongingness ◽  
Perceived Burdensomeness ◽  
Korean Adolescents ◽  
Related Stress

Abstract. Background: A significant number of Korean adolescents have suicidal ideations and it is more prevalent among adolescents than any other age group in Korea. Aims: This study was conducted to attain a better understanding of the contributing factors to suicidal ideation among Korean adolescents. Method: We recruited 569 high school students in Grades 10 and 11 in Pyeongtaek, Korea. The Beck Scale for Suicidal Ideation was used to measure suicidal ideation as the outcome variable. The Interpersonal Needs Questionnaire, the Beck Hopelessness Scale, the School Related Stress Scale, the Olweus Bully/Victim Questionnaire, and the Youth Risk Behavior Surveillance questions were used to measure thwarted belongingness and perceived burdensomeness, hopelessness, school-related stress, bullying, and previous suicidal behaviors, respectively. Data analyses included descriptive statistics and structural equation modeling. Results: The findings suggest that perceived burdensomeness, hopelessness, school-related stress, and previous suicidal behaviors have significant direct effects on suicidal ideation. Hopelessness fully mediated the relation between thwarted belongingness and suicidal ideation, and partially mediated between perceived burdensomeness, school-related stress, and suicidal ideation. Conclusion: These findings provide more specific directions for a multidimensional suicide prevention program in order to be successful in reducing suicide rates among Korean adolescents.

Implicit Association Test: Separating Transsituationally Stable and Variable Components of Attitudes toward Gay Men

2003 ◽  
Vol 50 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Melanie C. Steffens ◽  
Axel Buchner
Keyword(s):  
Gay Men ◽  
Implicit Association Test ◽  
Structural Equation ◽  
Implicit Attitudes ◽  
Association Test ◽  
Situational Factors ◽  
Situational Factor ◽  
Equation Modeling ◽  
Implicit Attitude ◽  
Implicit Association

Implicit attitudes are conceived of as formed in childhood, suggesting extreme stability. At the same time, it has been shown that implicit attitudes are influenced by situational factors, suggesting variability by the moment. In the present article, using structural equation modeling, we decomposed implicit attitudes towards gay men into a person factor and a situational factor. The Implicit Association Test ( Greenwald, McGhee, & Schwartz, 1998 ), introduced as an instrument with which individual differences in implicit attitudes can be measured, was used. Measurement was repeated after one week (Experiment 1) or immediately (Experiment 2). Explicit attitudes towards gay men as assessed by way of questionnaires were positive and stable across situations. Implicit attitudes were relatively negative instead. Internal consistency of the implicit attitude assessment was exemplary. However, the within-situation consistency was accompanied by considerable unexplained between-situation variability. Consequently, it may not be adequate to interpret an individual implicit attitude measured at a given point in time as a person-related, trait-like factor.

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