The Relation of Oxygen Consumption to Substrate Particle Size in Two Burrowing Mayflies

1963 ◽  
Vol 40 (3) ◽  
pp. 447-454
Author(s):  
CLYDE H. ERIKSEN
Keyword(s):  
Particle Size ◽  
Oxygen Consumption ◽  
Inverse Relationship ◽  
Standard Technique ◽  
Substrate Selection ◽  
Selection Experiments ◽  
Selection For ◽  
Hexagenia Limbata ◽  
The Relationship ◽  
Substrate Particle

1. This study is concerned with the relation of oxygen consumption to substrate particle size in the morphologically similar burrowing mafies Ephemera simulansand Hexagenia limbata. 2. Nymphs, 16-24 mm. in length, were placed at 13.0°C. for 24 hr. before experimentation. Oxygen consumption experiments employed the standard ‘oxygen consumed in a closed bottle ’ technique and a modification. The standard technique was referred to as the ‘blank-bottle’ method, while the modification was called the ‘substrate-bottle’ method (washed substrate fractions were placed in the bottle). 3. The relationship between substrate particle size and oxygen consumption was indicated by a bimodal curve. The oxygen consumption fell, rose and fell once more as the particle size decreased from χ - 4 to χ + 5. 4. Substrate selection experiments with E. simulans nymphs revealed an inverse relationship between selection for particle size and oxygen consumption. 5. The burrowing front legs of the nymphs seem to be modified for a given substrate (coarse for E. simulans; fine for H. limbata) and, the less favourable the substrate, the more work that must be done to gain admittance or to burrow further. The particle size in which the nymphs showed the least oxygen consumption was considered to be an ‘optimal substrate’(χ- 1 for E. simulans and probably silt for H. limbata).

Quantification of the kinetic differences between communities isolated from completely mixed activated sludge systems operated with or without a selector using a novel respirometric method

1994 ◽  
Vol 30 (11) ◽  
pp. 255-261 ◽  
Author(s):  
Barth F. Smets ◽  
Timothy G. Ellis ◽  
Stephanie Brau ◽  
Richard W. Sanders ◽  
C. P. Leslie Grady
Keyword(s):  
Oxygen Consumption ◽  
Activated Sludge ◽  
Physiological Changes ◽  
Biodegradation Kinetics ◽  
Substrate Removal ◽  
Biomass Yields ◽  
Selection For ◽  
Single Oxygen ◽  
Activated Sludge Systems

This study quantified the kinetic differences in microbial communities isolated from completely mixed activated sludge (CMAS) systems that were operated either with or without an aerobic selector preceding the main reactor. A new respirometric method was employed that allowed the determination of biodegradation kinetics from single oxygen consumption curves, thereby minimizing physiological changes to the examined communities during the assay. Results indicated that increased values for Ks and μmax for acetate, phenol, and 4-chlorophenol degradation were measured in the CMAS system operated with a selector. The biomass yields on acetate, phenol, and 4-chlorophenol were very similar in both systems. These findings indicate that the operation of CMAS systems with aerobic selectors may result in the selection for degrading populations with higher Ks and μmax values for both biogenic and xenobiotic organic compounds, and that substrate storage in the selector only partially contributes to increased substrate removal rates.

Association between Social Media Use for Health Purpose and Depressive Symptoms: A Cross-Sectional Survey (Preprint)

2020 ◽  
Author(s):  
Hee Yun Lee ◽  
Yan Luo ◽  
Cho Rong Won ◽  
Jiyoung Lee ◽  
Jeongwon Baik
Keyword(s):  
Social Media ◽  
Depressive Symptoms ◽  
Social Networking Sites ◽  
Inverse Relationship ◽  
Age Groups ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Use Of Social Media ◽  
The Relationship ◽  
Health Purpose

BACKGROUND The use of social media or social networking sites (SNS) is increasing across all age groups, and one of the primary motives of using SNS is to seek health-related information. Although previous research examining the effect of SNS use on depression exist, studies regarding the effect of SNS use for health purpose on depression is limited. OBJECTIVE Our study aims to explore the relationship between SNS use for health purpose and depression across the four age groups (18-34 years old, 35-49 years old, 50-64 years old, and above 65 years old). METHODS A sample of 6,789 adults aged 18 and older was extracted from a 2017 and 2018 Health Information National Trends Survey (HINTS). Univariate and bivariate analyses to examine the association between each variable and four age groups were conducted. Multiple linear regression analyses to predict depression level among participants with use of SNS for health purpose were conducted. RESULTS SNS use for health purpose and depression were positively associated for three age groups but not for those 65 years or older (=0.13, P<0.05; =0.08, P<0.05; =0.09, P<0.05). Income and self-reported health status indicated an inverse relationship for all age groups. The relationship with marital status differed based on age group with 18 and 34 years old showing an inverse relationship (=-0.13, P<0.01) while 65 years or older showing a positive relationship (=0.06, P<0.05). Gender was positively associated among those in the 35-49 years old (=0.09, P<0.05) and 65 years or older (=0.07, P<0.05). Being Non-Hispanic White was positively associated with depression among 50-64 years old (=0.07, P<0.001) and 65 years or older (=0.08, P<0.05). CONCLUSIONS Age-tailored education on determining accurate and reliable information shared via SNS is needed to reduce depressive symptoms.

Simulation on Extrusion Comminution Model of Roller Press

2010 ◽  
Vol 156-157 ◽  
pp. 1702-1707
Author(s):  
Xiang Wen Cheng ◽  
Jinchao Liu ◽  
Qi Zhi Ding ◽  
Li Ming Song ◽  
Zhan Lin Wang
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Field Experiments ◽  
Size Ratio ◽  
Optimum Operating ◽  
Extrusion Force ◽  
Particle Size Ratio ◽  
Small Constant ◽  
Working Parameters ◽  
The Relationship

How to predict the relationship among particle size and among product size, to establish the relationship between the granularity and working parameters in the process of grinding and to determine the optimum operating parameters. With proposing BS squeeze crush model by L. Bass and the idea of roll surface division as the material uneven extrusion force are adopted. Based on field experiments the experimental data is analyzed, the select function and the breakage functions are fitted with MATLAB software, and obtaining their model. The comminution model is determined by the roller division. We obtain the model parameter through the experimental data. Through model analysis shows: the relationship between particle breakage and energy absorption, namely the smaller size of the same power, the lower broken; the breakage diminishes with the decrease of particle size ratio and it will be tending to a small constant when the smaller particle size ratio. The breakage functions rapidly decrease within ratio of between 0.2-0.7. This shows: the energy consumption will rapidly increase when the particle size of less than 0.2 in broken; the selection diminish with the decrease of particle size. Pressure (8-9MPa) should be the most appropriate value.

scholarly journals Regulating the Regulators: Mechanisms of Substrate Selection of the O-GlcNAc Cycling Enzymes OGT and OGA

Glycobiology ◽  
2021 ◽  
Author(s):  
Hannah M Stephen ◽  
Trevor M Adams ◽  
Lance Wells
Keyword(s):  
Nutrient Sensing ◽  
Substrate Selection ◽  
Disease States ◽  
Dynamic Modification ◽  
Selection For ◽  
Outstanding Question ◽  
Glcnac Transferase ◽  
Future Work ◽  
Partner Proteins ◽  
Selection Of

Abstract Thousands of nuclear and cytosolic proteins are modified with a single β-N-acetylglucosamine on serine and threonine residues in mammals, a modification termed O-GlcNAc. This modification is essential for normal development and plays important roles in virtually all intracellular processes. Additionally, O-GlcNAc is involved in many disease states, including cancer, diabetes, and X-linked intellectual disability. Given the myriad of functions of the O-GlcNAc modification, it is therefore somewhat surprising that O-GlcNAc cycling is mediated by only two enzymes: the O-GlcNAc transferase (OGT), which adds O-GlcNAc, and the O-GlcNAcase (OGA), which removes it. A significant outstanding question in the O-GlcNAc field is how do only two enzymes mediate such an abundant and dynamic modification. In this review, we explore the current understanding of mechanisms for substrate selection for the O-GlcNAc cycling enzymes. These mechanisms include direct substrate interaction with specific domains of OGT or OGA, selection of interactors via partner proteins, posttranslational modification of OGT or OGA, nutrient sensing, and localization alteration. Altogether, current research paints a picture of an exquisitely regulated and complex system by which OGT and OGA select substrates. We also make recommendations for future work, toward the goal of identifying interaction mechanisms for specific substrates that may be able to be exploited for various research and medical treatment goals.

scholarly journals Macronutrient Quality and All-Cause Mortality in the SUN Cohort

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 972
Author(s):  
Susana Santiago ◽  
Itziar Zazpe ◽  
Cesar I. Fernandez-Lazaro ◽  
Víctor de la de la O ◽  
Maira Bes-Rastrollo ◽  
...  
Keyword(s):  
Quality Index ◽  
Inverse Relationship ◽  
A Priori ◽  
The Sun ◽  
Significant Inverse Relationship ◽  
Carbohydrate Quality ◽  
All Cause Mortality ◽  
Middle Aged Adults ◽  
The Relationship

No previous study has assessed the relationship between overall macronutrient quality and all-cause mortality. We aimed to prospectively examine the association between a multidimensional macronutrient quality index (MQI) and all-cause mortality in the SUN (Seguimiento Universidad de Navarra) (University of Navarra Follow-Up) study, a Mediterranean cohort of middle-aged adults. Dietary intake information was obtained from a validated 136-item semi-quantitative food-frequency questionnaire. We calculated the MQI (categorized in quartiles) based on three quality indexes: the carbohydrate quality index (CQI), the fat quality index (FQI), and the healthy plate protein source quality index (HPPQI). Among 19,083 participants (mean age 38.4, 59.9% female), 440 deaths from all causes were observed during a median follow-up of 12.2 years (IQR, 8.3–14.9). No significant association was found between the MQI and mortality risk with multivariable-adjusted hazard ratio (HR) for the highest vs. the lowest quartile of 0.79 (95% CI, 0.59–1.06; Ptrend = 0.199). The CQI was the only component of the MQI associated with mortality showing a significant inverse relationship, with HR between extreme quartiles of 0.64 (95% CI, 0.45–0.90; Ptrend = 0.021). In this Mediterranean cohort, a new and multidimensional MQI defined a priori was not associated with all-cause mortality. Among its three sub-indexes, only the CQI showed a significant inverse relationship with the risk of all-cause mortality.

scholarly journals CHARACTERISTICS AND ADSORPTION PERFORMANCE OF FORMULATED TRIKOTAC FILTER AIDS

2019 ◽  
Vol 81 (3) ◽  
Author(s):  
N. Masdiana ◽  
M. Rashid ◽  
S. Hajar ◽  
M. R. Ammar
Keyword(s):  
Particle Size ◽  
Activated Carbon ◽  
Particle Density ◽  
Adsorption Properties ◽  
The Other ◽  
Bet Surface Area ◽  
Adsorption Performance ◽  
Filtration System ◽  
Filter Aids ◽  
The Relationship

TrikotAC filter aids is a combination of a pre-coating material PreKot™ with two adsorbents; activated carbon and lime and their characteristics were investigated in this study. TrikotAC was formulated into three different weight ratios of 5:1:94, 10:1:89 and 10:5:85, respectively. The relationship between adsorption properties and characteristics of the formulated materials particle size distribution, particle density, bulk density, and BET surface area were investigated. The results showed that the adsorption capacity for TrikotAC 10:5:85 (11.88 mg/g) was higher than for the other formulated filter aids samples, and the formulated filter aids material TrikotAC showed promising characteristic as a filter aids and adsorbent for organic compound in fabric filtration system.

scholarly journals Particle Size Distribution Based Occurrence Features of Organic Components in Printing and Dyeing Wastewater Under a Treatment Process

2019 ◽  
Vol 118 ◽  
pp. 04009
Author(s):  
Yuan Li ◽  
Jie Liu ◽  
Yibiao Yu ◽  
Hao Zhu ◽  
Zheng Shen ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Reverse Osmosis ◽  
Treatment Process ◽  
Dyeing Wastewater ◽  
Wastewater Treatment Process ◽  
Printing And Dyeing Wastewater ◽  
Sedimentation Tank ◽  
The Relationship

A more detailed occurrence features of organic matters in the printing and dyeing wastewater, based on its particle size distribution (PSD) and along with a wastewater treatment process, was conducted to provide a support for advanced treatment. Results suggested that, (1) In the dyeing wastewater, the occurrence characteristic of COD was: soluble>supra colloidal>colloidal>settleable; However, for protein, the supra colloidal was dominant, followed by the soluble. The feature of the polysaccharide was consistent with COD’s. In the wastewater, 29.66% of COD could be attributed to proteins and 3.45% of the COD could be attributed to polysaccharides. (2) The relationship among the forms of COD in the primary sedimentation tank, aerobic tank, secondary sedimentation tank, and reverse osmosis-treated concentrated effluent was consistent, that was: soluble>colloidal>supra colloidal>settleable. (3) In the primary sedimentation tank, the settleable COD was almost completely removed; In the aerobic tank, the residual super colloidal COD was not much; After MBR-RO treatment, the COD in the reverse osmosis concentrated water was almost dissolved and only a little presented in other forms.

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