scholarly journals Disturbance triggers non-linear microbe–environment feedbacks

2021 ◽  
Vol 18 (16) ◽  
pp. 4773-4789
Author(s):  
Aditi Sengupta ◽  
Sarah J. Fansler ◽  
Rosalie K. Chu ◽  
Robert E. Danczak ◽  
Vanessa A. Garayburu-Caruso ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Thermodynamic Properties ◽  
Conceptual Framework ◽  
Hyporheic Zone ◽  
Archaeal Community ◽  
Community Property ◽  
Bacterial And Archaeal Communities ◽  
History Of ◽  
Environmental Component

Abstract. Conceptual frameworks linking microbial community membership, properties, and processes with the environment and emergent function have been proposed but remain untested. Here we refine and test a recent conceptual framework using hyporheic zone sediments exposed to wetting–drying transitions. Our refined framework includes relationships between cumulative properties of a microbial community (e.g., microbial membership, community assembly properties, and biogeochemical rates), environmental features (e.g., organic matter thermodynamics), and emergent ecosystem function. Our primary aim was to evaluate the hypothesized relationships that comprise the conceptual framework and contrast outcomes from the whole and putatively active bacterial and archaeal communities. Throughout the system we found threshold-like responses to the duration of desiccation. Membership of the putatively active community – but not the whole bacterial and archaeal community – responded due to enhanced deterministic selection (an emergent community property). Concurrently, the thermodynamic properties of organic matter (OM) became less favorable for oxidation (an environmental component), and respiration decreased (a microbial process). While these responses were step functions of desiccation, we found that in deterministically assembled active communities, respiration was lower and thermodynamic properties of OM were less favorable. Placing the results in context of our conceptual framework points to previously unrecognized internal feedbacks that are initiated by disturbance and mediated by thermodynamics and that cause the impacts of disturbance to be dependent on the history of disturbance.

scholarly journals Disturbance Triggers Non-Linear Microbe-Environment Feedbacks

2021 ◽  
Author(s):  
Aditi Sengupta ◽  
Sarah J. Fansler ◽  
Rosalie K. Chu ◽  
Robert E. Danczak ◽  
Vanessa A. Garayburu-Caruso ◽  
...  
Keyword(s):  
Organic Matter ◽  
Conceptual Framework ◽  
Community Assembly ◽  
Hyporheic Zone ◽  
Community Membership ◽  
Step Functions ◽  
Community Property ◽  
History Of ◽  
Environmental Component ◽  
Emergent Community

Abstract. Conceptual frameworks linking microbial community membership, properties, and processes with the environment and emergent function have been proposed but remain untested. Here we refine and test a recent conceptual framework using hyporheic zone sediments exposed to wetting/drying transitions. Throughout the system we found threshold-like responses to the duration of desiccation. Membership of the putatively active community – but not the whole community – responded due to enhanced deterministic selection (an emergent community property). Concurrently, the thermodynamic properties of organic matter became less favorable for oxidation (an environmental component) and respiration decreased (a microbial process). While these responses were step functions of desiccation, we observed continuous monotonic relationships among community assembly, respiration, and organic matter thermodynamics. Placing the results in context of our conceptual framework points to previously unrecognized internal feedbacks that are initiated by disturbance, mediated by thermodynamics, and that cause the impacts of disturbance to be dependent on the history of disturbance.

scholarly journals Disturbance Triggers Non-Linear Microbe-Environment Feedbacks

2020 ◽  
Author(s):  
Aditi Sengupta ◽  
Sarah J. Fansler ◽  
Rosalie K. Chu ◽  
Robert E. Danczak ◽  
Vanessa A. Garayburu-Caruso ◽  
...  
Keyword(s):  
Organic Matter ◽  
Conceptual Framework ◽  
Community Assembly ◽  
Hyporheic Zone ◽  
Community Membership ◽  
Step Functions ◽  
Community Property ◽  
History Of ◽  
Environmental Component ◽  
Emergent Community

AbstractConceptual frameworks linking microbial community membership, properties, and processes with the environment and emergent function have been proposed but remain untested. Here we refine and test a recent conceptual framework using hyporheic zone sediments exposed to wetting/drying transitions. Throughout the system we found threshold-like responses to the duration of desiccation. Membership of the putatively active community--but not the whole community--responded due to enhanced deterministic selection (an emergent community property). Concurrently, the thermodynamic properties of organic matter became less favorable for oxidation (an environmental component) and respiration decreased (a microbial process). While these responses were step functions of desiccation, we observed continuous monotonic relationships among community assembly, respiration, and organic matter thermodynamics. Placing the results in context of our conceptual framework points to previously unrecognized internal feedbacks that are initiated by disturbance, mediated by thermodynamics, and that cause the impacts of disturbance to be dependent on the history of disturbance.

scholarly journals Weaning Age Affects the Development of the Ruminal Bacterial and Archaeal Community in Hu Lambs During Early Life

2021 ◽  
Vol 12 ◽  
Author(s):  
Huiling Mao ◽  
Yanfang Zhang ◽  
Yan Yun ◽  
Wenwen Ji ◽  
Zhao Jin ◽  
...  
Keyword(s):  
Microbial Community ◽  
Relative Abundance ◽  
Age Groups ◽  
Lactate Concentration ◽  
Archaeal Community ◽  
Milk Replacer ◽  
Significant Difference ◽  
Weaning Age ◽  
Bacterial And Archaeal Communities ◽  
Positive Correlations

Weaning plays an important role in many animal processes, including the development of the rumen microbiota in ruminants. Attaining a better understanding of the development of the rumen microbial community at different weaning stages can aid the identification of the optimal weaning age. We investigated the effects of weaning age on ruminal bacterial and archaeal communities in Hu lambs. Thirty male Hu lambs were randomly assigned to two weaning-age groups: a group weaned at 30 days of age (W30) and a group weaned at 45 days of age (W45), with each group having five replicate pens. On the weaning day (day 30 for W30 and day 45 for W45) and at 5 days postweaning [day 35 for W30 (PW30) and day 50 for W45 (PW45)], one lamb from each replicate was randomly selected and sacrificed. Rumen contents were collected to examine the ruminal microbiota. Compared to W30, PW30 had a decreased relative abundance of Bacteroidetes. At genus level, the extended milk replacer feeding (W45 vs. W30) increased the relative abundance of Ruminococcus while decreased that of Prevotella and Dialister. Compared to W30, PW30 exhibited decreased relative abundances of Prevotella, Dialister and Bacteroides but an increased unclassified Coriobacteriaceae. No significant difference was noted in the detected archaeal taxa among the animals. The function “biosynthesis of secondary metabolites” was less predominant in PW30 than in W30, whereas the opposite held true for “metabolism of cofactors and vitamins.” Some bacterial genera were significantly correlated with rumen volatile fatty acid (VFA) concentration or other animal measures, including negative correlations between ruminal VFA concentration and unclassified Mogibacteriaceae and unclassified Veillonellaceae; positive correlations of ruminal papillae length with Fibrobacter and unclassified Lachnospiraceae, but negative correlations with Mitsuokella and Succiniclasticum; and negative correlations between plasma D-lactate concentration and Prevotella, unclassified Paraprevotellaceae, and Desulfovibrio. Our results revealed that the ruminal bacterial community underwent larger changes over time in lambs weaned at 30 days of age than in lambs weaned half a month later. Thus, extending milk replacer feeding to 45 days weaning was recommended from the perspective of the rumen microbial community in the Hu lamb industry.

Elements for a General Organology

Derrida Today ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 72-94
Author(s):  
Bernard Stiegler
Keyword(s):  
Organic Matter ◽  
Planetary Scale ◽  
General Account ◽  
Inorganic Matter ◽  
History Of

These lectures outline the project of a general organology, which is to say an account of life when it is no longer just biological but technical, or when it involves not just organic matter but organized inorganic matter. This organology is also shown to require a modified Simondonian account of the shift from vital individuation to a three-stranded process of psychic, collective and technical individuation. Furthermore, such an approach involves extending the Derridean reading of Socrates's discussion of writing as a pharmakon, so that it becomes a more general account of the pharmacological character of retention and protention. By going back to Leroi-Gourhan, we can recognize that this also means pursuing the history of retentional modifications unfolding in the course of the history of what, with Lotka, can also be called exosomatization. It is thus a question of how exteriorization can, today, in an epoch when it becomes digital, and in an epoch that produces vast amounts of entropy at the thermodynamic, biological and noetic levels, still possibly produce new forms of interiorization, that is, new forms of thought, care and desire, amounting to so many chances to struggle against the planetary-scale pharmacological crisis with which we are currently afflicted.

scholarly journals Microbial Community Structure Affects Marine Dissolved Organic Matter Composition

2016 ◽  
Vol 3 ◽  
Author(s):  
Elizabeth B. Kujawinski ◽  
Krista Longnecker ◽  
Katie L. Barott ◽  
Ralf J. M. Weber ◽  
Melissa C. Kido Soule
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Microbial Community ◽  
Dissolved Organic Matter ◽  
Microbial Community Structure ◽  
Organic Matter Composition

Exploring the boundaries of rhetoric

2014 ◽  
Vol 27 (5) ◽  
pp. 793-806 ◽  
Author(s):  
Eduard Bonet
Keyword(s):  
Social Sciences ◽  
Conceptual Framework ◽  
Design Methodology ◽  
The Self ◽  
History Of Rhetoric ◽  
Content Type ◽  
History Of ◽  
Practical Development ◽  
The Subject

Purpose – The purpose of this paper is to examine how the boundaries of rhetoric have excluded important theoretical and practical subjects and how these subjects are recuperated and extended since the twentieth century. Its purpose is to foster the awareness on emerging new trends of rhetoric. Design/methodology/approach – The methodology is based on an interpretation of the history of rhetoric and on the construction of a conceptual framework of the rhetoric of judgment, which is introduced in this paper. Findings – On the subject of the extension of rhetoric from public speeches to any kinds of persuasive situations, the paper emphasizes some stimulating relationships between the theory of communication and rhetoric. On the exclusion and recuperation of the subject of rhetorical arguments, it presents the changing relationships between rhetoric and dialectics and emphasizes the role of rhetoric in scientific research. On the introduction of rhetoric of judgment and meanings it creates a conceptual framework based on a re-examination of the concept of judgment and the phenomenological foundations of the interpretative methods of social sciences by Alfred Schutz, relating them to symbolic interactionism and theories of the self. Originality/value – The study on the changing boundaries of rhetoric and the introduction of the rhetoric of judgment offers a new view on the present theoretical and practical development of rhetoric, which opens new subjects of research and new fields of applications.

Functional role of earthworms to control the hydraulic conductivity of constructed wetlands 

2021 ◽  
Author(s):  
Océane Gilibert ◽  
Dan Tam Costa ◽  
Sabine Sauvage ◽  
Didier Orange ◽  
Yvan Capowiez ◽  
...  
Keyword(s):  
Organic Matter ◽  
Hydraulic Conductivity ◽  
Constructed Wetlands ◽  
Hyporheic Zone ◽  
Riparian Zone ◽  
Water Flux ◽  
Sediment Surface ◽  
Deep Soil ◽  
The Impact ◽  
Organic Matter Input

<p>Wetlands are known for their natural service of water quality regulation. The hyporheic zones of the rivers filter and purify the surface water from the stream and infiltrated waters in soil nearby through the riparian zone. This purification service occurs because of a synergy between the substrate and its biodiversity (including plants, bacteria and other invertebrates). Our study deals with constructed wetlands (CW) as a nature-based solution mimicking wetlands water purification process, to purify wastewaters. The REUSE technology of CW is based on the use of specific layers of gravels and sands inside a close concrete structure, planted with specific sub-aquatic plants, where wastewaters or runoff of stormwaters are introduced to be filtered. The technology of Vertical Flow Constructed Wetlands (VFCW) reproduces the water flux observed in the riparian zone with a gravity flow of water. It is composed of reeds planted on a sandy layer (Ø 0-4 mm) and succession of gravel layers. This substrate can be saturated or unsaturated to reproduce the functioning of the hyporheic zone or the riparian zone respectively. By the time, the substrate is colonized by a community of bacteria producing biofilms which capture the residual organic matter from wastewaters to mineralize them. However, the VFCW substrates tend to clog over time due to the accumulation of organic matter and biofilms. Many studies consider earthworms as one of the solutions to alleviate this clogging, thanks to their burrows recreating macropores and preferential channels which help to improve the dispersion of water into the deep soil. The main goal of this study is to assess the impact of earthworm activities on the hydraulic conductivity of columns composed with the same substrate used in the VFCW. Different densities of earthworms (Eisenia fetida) were introduced (0, 100, 500, 1000 g of earthworms/m²) in these columns to be monitored for 37 days. The hydraulic conductivity was measured every 7 days, aside from day 23 with the addition of 40 g of peat bedding on column surfaces to simulate a high organic matter input. Columns with earthworm density superior to 500 g/m² shows an amelioration of their hydraulic conductivity after 21 days. These densities are also able to restore the hydraulic conductivity of the column in less than 7 days after the setting of clogged condition due to the organic matter input (peat bedding) at the sediment surface. This study showed that the burrowing activity of E. fetida improves the hydraulic flux of a sandy substrate and this impact is dependent on the earthworm density introduced. So, the addition of earthworms in the VFCW could serve as a prevention against clogging.</p>

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