scholarly journals 4 SPECIES OF BACTERIA DETERMINISTICALLY FORM A STABLE BIOFILM IN A MILLIFLUIDIC CHANNEL: ASSEMBLY PRINCIPLES

2021 ◽  
Author(s):  
Amaury Monmeyran ◽  
Wafa Benyoussef ◽  
Philippe Thomen ◽  
Narimane Dahmane ◽  
Aurelie Baliarda ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Environmental Parameters ◽  
Individual Species ◽  
Interspecies Interactions ◽  
Laboratory Setup ◽  
Quantitative Measurements ◽  
Channel Assembly ◽  
Emergence Of Complexity ◽  
And Control ◽  
Assembly Principles

Multispecies microbial adherent communities are widespread in nature and organisms but the principles of their assembly and development remain unclear. Yet, the demand to understand and predict the responses of such living communities to environmental changes is increasing, calling for new approaches. Here, we test the possibility to establish a simplified but relevant model of multispecies biofilm in a laboratory setup enabling in situ real-time monitoring of the community development and control of the environmental parameters in order to decipher the mechanisms underlying the formation of the community. Using video-microscopy and species combinatorial approach, we assess the global and individual species spatiotemporal development in millifluidic channels under constant flow of nutrients. Based on quantitative measurements of expansion kinetics, local dynamics and spatial distribution, we demonstrate that the four chosen species (Bacillus thuringiensis, Pseudomonas fluorescens, Kocuria varians and Rhodocyclus sp.) form a dynamical community that deterministically reaches its equilibrium after about 30 hours of growth. We evidence the emergence of complexity in this simplified community as reported by spatial heterogeneity rise and non-monotonic developmental kinetics. We find interspecies interactions consisting in competition for resources - in particular oxygen - and both direct and indirect physical interactions but no positive feedback. Thereby, we introduce a model of multispecies adherent community where effective couplings result from individual species quest for fitness optimization in a moving and heterogenous environment. This control and the understanding of this simplified experimental model shall open new avenues to apprehend adherent bacterial communities behavior in a context of rapid global change.

scholarly journals Distribution and Control of Bacterial Community Composition in Marian Cove Surface Waters, King George Island, Antarctica during the Summer of 2018

2020 ◽  
Vol 8 (8) ◽  
pp. 1115
Author(s):  
Soyeon Kim ◽  
Ju-Hyoung Kim ◽  
Jae-Hyun Lim ◽  
Jin-Hyun Jeong ◽  
Jang-Mu Heo ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Spatial Variation ◽  
Community Composition ◽  
Surface Waters ◽  
Bacterial Communities ◽  
Environmental Changes ◽  
Bacterial Community Composition ◽  
Environmental Parameters ◽  
And Control ◽  
The Antarctic

Marian Cove is experiencing some of the most rapid environmental changes in the Antarctic region; however, little is known about the response of bacterial communities to these changes. The main purpose of this study was to investigate the spatial variation of physical–biogeochemical–bacterial community features in the Marian Cove surface waters and the environmental parameters governing the spatial variation in the bacterial community composition during the summer of 2018. The Marian Cove surface waters are largely composed of two different characteristics of water masses: relatively low-temperature, -salinity, and -nutrient surface glacier water (named SGW) and relatively high-temperature, -salinity, and -nutrient surface Maxwell Bay water (named SMBW). The SGW bacterial communities were dominated by unclassified Cryomorphaceae, Sedimenticola, and Salibacter genera, while the SMBW bacterial communities were dominated by Sulfitobacter, Arcobacter, and Odoribacter genera. Spatial variations in bacterial community composition were mainly attributed to physical and biogeochemical characteristics, suggesting that the bacterial community composition of the Marian Cove surface waters is mainly determined by environmental characteristics. These findings provide a foundation to improve the understanding of bacterial community variations in response to a rapidly changing Marian Cove in the Antarctic.

scholarly journals Four species of bacteria deterministically assemble to form a stable biofilm in a millifluidic channel

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
A. Monmeyran ◽  
W. Benyoussef ◽  
P. Thomen ◽  
N. Dahmane ◽  
A. Baliarda ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Interspecies Interactions ◽  
Relevant Model ◽  
Non Invasive ◽  
Laboratory Setup ◽  
Multispecies Biofilm ◽  
Physical Interactions ◽  
Emergence Of Complexity ◽  
Dynamic Community ◽  
Competition For Resources

AbstractMultispecies microbial adherent communities are widespread in nature and organisms, although the principles of their assembly and development remain unclear. Here, we test the possibility of establishing a simplified but relevant model of multispecies biofilm in a non-invasive laboratory setup for the real-time monitoring of community development. We demonstrate that the four chosen species (Bacillus thuringiensis, Pseudomonas fluorescens, Kocuria varians, and Rhodocyclus sp.) form a dynamic community that deterministically reaches its equilibrium after ~30 h of growth. We reveal the emergence of complexity in this simplified community as reported by an increase in spatial heterogeneity and non-monotonic developmental kinetics. Importantly, we find interspecies interactions consisting of competition for resources—particularly oxygen—and both direct and indirect physical interactions. The simplified experimental model opens new avenues to the study of adherent bacterial communities and their behavior in the context of rapid global change.

Recirculation versus flow-through rainbow trout laboratory Flavobacterium columnare challenge

2020 ◽  
Vol 139 ◽  
pp. 213-221
Author(s):  
C Birkett ◽  
R Lipscomb ◽  
T Moreland ◽  
T Leeds ◽  
JP Evenhuis
Keyword(s):  
Rainbow Trout ◽  
Environmental Parameters ◽  
Cumulative Effects ◽  
Flavobacterium Columnare ◽  
Replacement Rate ◽  
Bacterial Concentration ◽  
Water Replacement ◽  
Dose Concentration ◽  
Flow Through ◽  
And Control

Flavobacterium columnare immersion challenges are affected by water-related environmental parameters and thus are difficult to reproduce. Whereas these challenges are typically conducted using flow-through systems, use of a recirculating challenge system to control environmental parameters may improve reproducibility. We compared mortality, bacterial concentration, and environmental parameters between flow-through and recirculating immersion challenge systems under laboratory conditions using 20 rainbow trout families. Despite identical dose concentration (1:75 dilution), duration of challenge, lot of fish, and temperature, average mortality in the recirculating system (42%) was lower (p < 0.01) compared to the flow-through system (77%), and there was low correlation (r = 0.24) of family mortality. Mean days to death (3.25 vs. 2.99 d) and aquaria-to-aquaria variation (9.6 vs. 10.4%) in the recirculating and flow-through systems, respectively, did not differ (p ≥ 0.30). Despite 10-fold lower water replacement rate in the recirculating (0.4 exchanges h-1) compared to flow-through system (4 exchanges h-1), differences in bacterial concentration between the 2 systems were modest (≤0.6 orders of magnitude) and inconsistent throughout the 21 d challenge. Compared to the flow-through system, dissolved oxygen during the 1 h exposure and pH were greater (p ≤ 0.02), and calcium and hardness were lower (p ≤ 0.03), in the recirculating system. Although this study was not designed to test effects of specific environmental parameters on mortality, it demonstrates that the cumulative effects of these parameters result in poor reproducibility. A recirculating immersion challenge model may be warranted to empirically identify and control environmental parameters affecting mortality and thus may serve as a more repeatable laboratory challenge model.

scholarly journals The intensity of slope and fluvial processes after a catastrophic windthrow event in small catchments in the Tatra Mountains

2021 ◽  
Vol 18 (6) ◽  
pp. 1405-1423
Author(s):  
Dariusz Strzyżowski ◽  
Elżbieta Gorczyca ◽  
Kazimierz Krzemień ◽  
Mirosław Żelazny
Keyword(s):  
Environmental Changes ◽  
Bedload Transport ◽  
Strong Wind ◽  
Tatra Mountains ◽  
Salvage Logging ◽  
Fluvial Processes ◽  
Wind Events ◽  
And Control ◽  
The Tatra Mountains ◽  
The Impact

AbstractStrong wind events frequently result in creating large areas of windthrow, which causes abrupt environmental changes. Bare soil surfaces within pits and root plates potentially expose soil to erosion. Absence of forest may alter the dynamics of water circulation. In this study we attempt to answer the question of whether extensive windthrows influence the magnitude of geomorphic processes in 6 small second- to third-order catchments with area ranging from 0.09 km2 to 0.8 km2. Three of the catchments were significantly affected by a windthrow which occurred in December 2013 in the Polish part of the Tatra Mountains, and the other three catchments were mostly forested and served as control catchments. We mapped the pits created by the windthrow and the linear scars created by salvage logging operations in search of any signs of erosion within them. We also mapped all post-windthrow landslides created in the windthrow-affected catchments. The impact of the windthrow on the fluvial system was investigated by measuring a set of channel characteristics and determining bedload transport intensity using painted tracers in all the windthrow-affected and control catchments. Both pits and linear scars created by harvesting tend to become overgrown by vegetation in the first several years after the windthrow. The only signs of erosion were observed in 10% of the pits located on convergent slopes. During the period from the windthrow event in 2013 until 2019, 5 very small (total area <100 m2) shallow landslides were created. The mean distance of bedload transport was similar (t-test, p=0.05) in most of the windthrow-affected and control catchments. The mapping of channels revealed many cases of root plates fallen into a channel and pits created near a channel. A significant amount of woody debris delivered into the channels influenced the activity of fluvial processes by creating alternating zones of erosion and accumulation.

scholarly journals Virus-Like Particles Produced Using the Brome Mosaic Virus Recombinant Capsid Protein Expressed in a Bacterial System

2021 ◽  
Vol 22 (6) ◽  
pp. 3098
Author(s):  
Aleksander Strugała ◽  
Jakub Jagielski ◽  
Karol Kamel ◽  
Grzegorz Nowaczyk ◽  
Marcin Radom ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Mosaic Virus ◽  
Capsid Protein ◽  
Self Assembly ◽  
Environmental Changes ◽  
Expression System ◽  
Brome Mosaic Virus ◽  
Virus Like Particles ◽  
Assembly Principles ◽  
The Impact

Virus-like particles (VLPs), due to their nanoscale dimensions, presence of interior cavities, self-organization abilities and responsiveness to environmental changes, are of interest in the field of nanotechnology. Nevertheless, comprehensive knowledge of VLP self-assembly principles is incomplete. VLP formation is governed by two types of interactions: protein–cargo and protein–protein. These interactions can be modulated by the physicochemical properties of the surroundings. Here, we used brome mosaic virus (BMV) capsid protein produced in an E. coli expression system to study the impact of ionic strength, pH and encapsulated cargo on the assembly of VLPs and their features. We showed that empty VLP assembly strongly depends on pH whereas ionic strength of the buffer plays secondary but significant role. Comparison of VLPs containing tRNA and polystyrene sulfonic acid (PSS) revealed that the structured tRNA profoundly increases VLPs stability. We also designed and produced mutated BMV capsid proteins that formed VLPs showing altered diameters and stability compared to VLPs composed of unmodified proteins. We also observed that VLPs containing unstructured polyelectrolyte (PSS) adopt compact but not necessarily more stable structures. Thus, our methodology of VLP production allows for obtaining different VLP variants and their adjustment to the incorporated cargo.

A Design of Coal Mine Security Monitoring Substation Based on ZIGBEE and CAN Bus

2014 ◽  
Vol 971-973 ◽  
pp. 1033-1036
Author(s):  
Hui Jun Wang ◽  
Zhi Qun Yong
Keyword(s):  
Coal Mine ◽  
Can Bus ◽  
Measurement Data ◽  
Environmental Parameters ◽  
Monitoring And Control ◽  
Monitoring And Control System ◽  
Security Monitoring ◽  
Mine Development ◽  
Security Monitoring System ◽  
And Control

In view of the shortcoming such as wiring difficulties, poor scalability, and big cable usage in present mine security monitoring system, this paper puts forward a kind of substation monitoring and control system based on ZIGBEE and CAN. With the core of core, The system collects various measurement data of sensors through the ZIGBEE wireless network, realizes the to collect, and then through the CAN bus to realize the transmission of control commands and data of the up and down machine, and monitor the production parameters and environmental parameters in the coal mine. Experiments show that the monitoring substation is of high real-time performance, good stability, strong expansibility, etc., and can meet the requirements of the coal mine development and mining.

Experimental Study on the Recirculation of Homogeneous and Stratified Fluid Layers in the Advanced Solar Pond

1994 ◽  
Vol 116 (2) ◽  
pp. 74-78 ◽  
Author(s):  
Y. Keren ◽  
H. Rubin ◽  
G. A. Bemporad
Keyword(s):  
Double Diffusion ◽  
Stratified Fluid ◽  
Experimental Investigations ◽  
Laboratory Setup ◽  
Solar Pond ◽  
Fluid Layers ◽  
Data Density ◽  
And Control ◽  
Stable Flow ◽  
Transient And Steady State

The practical possibilities of constructing and operating a stable flow of homogeneous and stratified fluid layers in a solar pond were investigated in this study. A laboratory setup was prepared to carry out the experimental investigations. Transient and steady-state conditions were analyzed. A numerical model was developed to simulate heat, salt, and momentum transfer in the water body. The model was calibrated with the experimental data. Density and temperature measurements along the laboratory setup showed the configuration to be stable in all of the conditions which were analyzed. These experimental results indicated that through a proper multiselective injection and withdrawal procedure it was possible to create and control the double-diffusion stratified fluid layers, which characterizes the advanced solar pond.

scholarly journals DESIGN AND CONTROL OF SPIDER ROBOT MODEL

2019 ◽  
Vol 1 (1) ◽  
pp. 90-93
Author(s):  
Tan Thanh Nguyen ◽  
Duy Khanh Nguyen
Keyword(s):  
Operating System ◽  
High Stability ◽  
Low Cost ◽  
Environmental Parameters ◽  
Environmental Data ◽  
Control Methods ◽  
Multiple Control ◽  
Android Operating System ◽  
And Control ◽  
Mit App Inventor

Robots imitating spider’s moving have many advantages such as flexible movement, high stability, diversity in movements performed, especially in terrain  crossing, in military reconnaissance, in surveying and collecting environmental data in dangerous areas,.... In this article  with the main objective is to exploit multiple control methods to support applications of a spider robot with low-cost, a spider robot with 6 legs and 18 joints was designed. The ESPWROOM-32 module (ESP32-D0WDQ6 chip) and MIT App Inventor were used as the main tools for conducting this research. As a result, the robot is controlled via Bluetooth and Wifi to move, making some actions by self-written software running on the Android operating system. In addition, the robot has the capacity of self-propelled to avoid simple obstacles and send some environmental parameters to the software, including obstacles distance, humidity and temperature.

scholarly journals Can the subterranean fauna be used as proxy for past environmental changes? – the example of the Carpathians cave fauna

2018 ◽  
Vol 1 ◽  
Author(s):  
Oana Teodora Moldovan ◽  
Ionut Cornel Mirea ◽  
Marius Kenesz
Keyword(s):  
Environmental Changes ◽  
Regional Scale ◽  
Environmental Parameters ◽  
General View ◽  
Carpathian Mountains ◽  
Small Areas ◽  
The Carpathians ◽  
Cave Fauna ◽  
Historical Processes ◽  
Geological Units

Carpathian Mountains were one of the main refuge areas during the climate changes of the Pleistocene and the Holocene in Europe and one of the richest regions in the world in subterranean (caves and associated habitats) endemic species. Nevertheless, the Carpathian Mountains subterranean fauna importance is underestimated especially due to dispersed information on its diversity and the scarcity of molecular studies in the area. Here, we present a first general view of the cave fauna hotspot represented by the Romanian Carpathians and the geological and historical processes that shaped the patterns of subterranean distribution and diversity at regional scale. The Carpathians are an amalgam of various geological units with complex paleogeographical evolution that is reflected in completely different species assemblages dominated by unit specific fauna groups. Phylogeography of Coleoptera and environmental parameters are adding to the general view at regional scale and offer additional explanation for this exceptional subterranean diversification in a non-Mediterranean region. We also use the example of the Carpathians cave fauna as proxy for past environmental changes in the area. Troglobionts are endemic on small areas and by studying their present distributions and phylogeny, past processes of landscape evolution on the surface can be better understood.

Human-Environmental Influences and Interactions in Shifting Agriculture When Farmers Form Expectations Rationally

1993 ◽  
Vol 25 (1) ◽  
pp. 121-136 ◽  
Author(s):  
D W Jones ◽  
R V O'Neill
Keyword(s):  
Interest Rates ◽  
Environmental Changes ◽  
Initial Period ◽  
Environmental Parameters ◽  
Land Rent ◽  
Fallow Period ◽  
Shifting Agriculture ◽  
Current Period ◽  
Expectations Formation ◽  
Future Value

This paper contains a study of the response of shifting agriculture to several social and environmental changes in circumstances in which farmers form in a relatively sophisticated manner their expectations of the future values of key economic variables. Farmers are ‘given’ a model of expectations formation in which the expected future value of variables interact in the same manner as in the current period. With this structure of expectations, the responses of the length of fallow period (the inverse of the percentage of available land cultivated in the initial period), the total area of land under cultivation and lying fallow in the initial period of a rotational cycle, and the initial-period wage rate and spatial structure of land rent to changes in several social and environmental parameters are examined. Several salient characteristics commonly attributed to shifting, or rotational, agriculture are replicated. Higher crop prices and increased population shorten fallow periods. Those same changes also increase the total area of land under shifting agriculture. Higher interest rates also shorten fallow periods. Fallows are longer at locations farther from central markets. Less commonly recognized is that social feedbacks operate to reduce pressure on more fragile land, although this does not imply that, other things being equal, fragile tropical land will not be ‘overused’ in an ecological sense.

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