scholarly journals Microbial Hotspots in Lithic Microhabitats Inferred from DNA Fractionation and Metagenomics in the Atacama Desert

2021 ◽  
Vol 9 (5) ◽  
pp. 1038
Author(s):  
Dirk Schulze-Makuch ◽  
Daniel Lipus ◽  
Felix L. Arens ◽  
Mickael Baqué ◽  
Till L. V. Bornemann ◽  
...  
Keyword(s):  
Microbial Activity ◽  
Time Use ◽  
Arid Regions ◽  
Atacama Desert ◽  
Soil Heterogeneities ◽  
Total Dna ◽  
Temporal And Spatial ◽  
Study Sites ◽  
First Time ◽  
Microbial Hotspots

The existence of microbial activity hotspots in temperate regions of Earth is driven by soil heterogeneities, especially the temporal and spatial availability of nutrients. Here we investigate whether microbial activity hotspots also exist in lithic microhabitats in one of the most arid regions of the world, the Atacama Desert in Chile. While previous studies evaluated the total DNA fraction to elucidate the microbial communities, we here for the first time use a DNA separation approach on lithic microhabitats, together with metagenomics and other analysis methods (i.e., ATP, PLFA, and metabolite analysis) to specifically gain insights on the living and potentially active microbial community. Our results show that hypolith colonized rocks are microbial hotspots in the desert environment. In contrast, our data do not support such a conclusion for gypsum crust and salt rock environments, because only limited microbial activity could be observed. The hypolith community is dominated by phototrophs, mostly Cyanobacteria and Chloroflexi, at both study sites. The gypsum crusts are dominated by methylotrophs and heterotrophic phototrophs, mostly Chloroflexi, and the salt rocks (halite nodules) by phototrophic and halotolerant endoliths, mostly Cyanobacteria and Archaea. The major environmental constraints in the organic-poor arid and hyperarid Atacama Desert are water availability and UV irradiation, allowing phototrophs and other extremophiles to play a key role in desert ecology.

Application of an Improved Colored Petri Net Modeling Method in Certain Missile Training System

2015 ◽  
Vol 742 ◽  
pp. 330-334
Author(s):  
Chun Jian Wang ◽  
Wei Yue ◽  
Hai Yan Ji
Keyword(s):  
Complex System ◽  
Petri Net ◽  
Time Use ◽  
Training System ◽  
New Method ◽  
Mathematics Model ◽  
Research Approach ◽  
Complex Environments ◽  
Training Simulator ◽  
First Time

In allusion to the need of analyzing complex system, we have proposed a method named multi-grade color Petri net. We for the first time use this new method to analyze a missile training simulator system. This model can accurately reflect the complex environments of the system and avoid the difficulty occurring often in developing accurate mathematics model by using classical research approach.

scholarly journals Presence of Mycobacterium avium Subspecies paratuberculosis Monitored Over Varying Temporal and Spatial Scales in River Catchments: Persistent Routes for Human Exposure

2019 ◽  
Vol 7 (5) ◽  
pp. 136 ◽  
Author(s):  
Hollian Richardson ◽  
Glenn Rhodes ◽  
Peter Henrys ◽  
Luigi Sedda ◽  
Andrew J. Weightman ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Human Exposure ◽  
Infected Animal ◽  
Wastewater Treatment Plants ◽  
Mycobacterium Avium Subspecies Paratuberculosis ◽  
Spatial Scales ◽  
Adequate Representation ◽  
Temporal And Spatial ◽  
First Time ◽  
River Catchments

Mycobacterium avium subspecies paratuberculosis (Map) was monitored by quantitative PCR over a range of temporal and spatial scales in the River Tywi catchment. This study shows the persistence of Map over a 10-year period with little change, which correlates with the recognised levels of Johne’s disease in British herds over that period (aim 1). Map was quantified within the river at up to 108 cell equivalents L−1 and was shown to be consistently present when monitored over finer timescales (aim 4). Small wastewater treatment plants where the ingress of human-associated Map might be expected had no significant effect (aim 2). Map was found for the first time to be located in natural river foams providing another route for spread via aerosols (aim 5). This study provides evidence for the environmental continuum of Map from the grazing infected animal via rain driven runoff through field drains and streams into main rivers; with detection at a high frequency throughout the year. Should Map need to be monitored in the future, we recommend that weekly or monthly sampling from a fixed location on a river will capture an adequate representation of the flow dynamics of Map in a catchment (aim 3). The human exposure to Map during this process and its impact on human health remains unquantified.

scholarly journals Rhythmic neural activity is comodulated with short-term gait modifications during first-time use of a dummy prosthesis: a pilot study

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Vera G. M. Kooiman ◽  
Helco G. van Keeken ◽  
Natasha M. Maurits ◽  
Vivian Weerdesteyn ◽  
Teodoro Solis-Escalante
Keyword(s):  
Time Use ◽  
Ground Reaction Force ◽  
Gait Cycle ◽  
Reaction Force ◽  
Swing Phase ◽  
Experimental Session ◽  
Cycle Duration ◽  
Short Term ◽  
Gamma Rhythms ◽  
First Time

Abstract Background After transfemoral amputation, many hours of practice are needed to re-learn walking with a prosthesis. The long adaptation process that consolidates a novel gait pattern seems to depend on cerebellar function for reinforcement of specific gait modifications, but the precise, step-by-step gait modifications (e.g., foot placement) most likely rely on top-down commands from the brainstem and cerebral cortex. The aim of this study was to identify, in able-bodied individuals, the specific modulations of cortical rhythms that accompany short-term gait modifications during first-time use of a dummy prosthesis. Methods Fourteen naïve participants walked on a treadmill without (one block, 4 min) and with a dummy prosthesis (three blocks, 3 × 4 min), while ground reaction forces and 32-channel EEG were recorded. Gait cycle duration, stance phase duration, step width, maximal ground reaction force and, ground reaction force trace over time were measured to identify gait modifications. Independent component analysis of EEG data isolated brain-related activity from distinct anatomical sources. The source-level data were segmented into gait cycles and analyzed in the time–frequency domain to reveal relative enhancement or suppression of intrinsic cortical oscillations. Differences between walking conditions were evaluated with one-way ANOVA and post-hoc testing (α = 0.05). Results Immediate modifications occurred in the gait parameters when participants were introduced to the dummy prosthesis. Except for gait cycle duration, these modifications remained throughout the duration of the experimental session. Power modulations of the theta, mu, beta, and gamma rhythms, of sources presumably from the fronto-central and the parietal cortices, were found across the experimental session. Significant power modulations of the theta, beta, and gamma rhythms within the gait cycle were predominately found around the heel strike of both feet and the swing phase of the right (prosthetic) leg. Conclusions The modulations of cortical activity could be related to whole-body coordination, including the swing phase and placing of the prosthesis, and the bodyweight transfer between legs and arms. Reduced power modulation of the gamma rhythm within the experimental session may indicate initial motor memories being formed. Better understanding of the sensorimotor processes behind gait modifications may inform the development of neurofeedback strategies to assist gait rehabilitation.

scholarly journals Application of dendroclimatology in evaluation of climatic changes

2018 ◽  
Vol 64 (No. 3) ◽  
pp. 139-147 ◽  
Author(s):  
Khaleghi Mohammad Reza
Keyword(s):  
Climate Change ◽  
Tree Rings ◽  
Arid Regions ◽  
Ring Width ◽  
Climatic Changes ◽  
The Past ◽  
Temperature And Precipitation ◽  
Temporal And Spatial ◽  
Artificial Neural Network Ann ◽  
High Degree

The present study tends to describe the survey of climatic changes in the case of the Bojnourd region of North Khorasan, Iran. Climate change due to a fragile ecosystem in semi-arid and arid regions such as Iran is one of the most challenging climatological and hydrological problems. Dendrochronology, which uses tree rings to their exact year of formation to analyse temporal and spatial patterns of processes in the physical and cultural sciences, can be used to evaluate the effects of climate change. In this study, the effects of climate change were simulated using dendrochronology (tree rings) and an artificial neural network (ANN) for the period from 1800 to 2015. The present study was executed using the Quercus castaneifolia C.A. Meyer. Tree-ring width, temperature, and precipitation were the input parameters for the study, and climate change parameters were the outputs. After the training process, the model was verified. The verified network and tree rings were used to simulate climatic parameter changes during the past times. The results showed that the integration of dendroclimatology and an ANN renders a high degree of accuracy and efficiency in the simulation of climate change. The results showed that in the last two centuries, the climate of the study area changed from semiarid to arid, and its annual precipitation decreased significantly.

Analysis of Interface between Free-Standing Diamond Films and Mo Substrates

2005 ◽  
Vol 475-479 ◽  
pp. 3615-3618
Author(s):  
Hui Qing Li ◽  
Cheng Ming Li ◽  
Guang Chao Chen ◽  
Fan Xiu Lu ◽  
Yu Mei Tong
Keyword(s):  
Phase Composition ◽  
Amorphous Carbon ◽  
Time Use ◽  
Diamond Films ◽  
Plasma Jet ◽  
Arc Plasma ◽  
Free Standing ◽  
Dc Arc ◽  
First Time ◽  
Gas Recycling

Interfaces between Mo substrate and free-standing diamond films prepared by DC arc plasma jet operated at gas recycling mode were investigated, including for the first time used and multi-time used substrate. The morphology, phase composition and bonding state of elements in the interface between substrates and diamond films were examined by optical microscopy, XRD and XPS. The profiles of carbon concentration of Mo substrates were measured by GDOES. It showed that Mo2C and MoC were formed on the first time used Mo substrate, and MoC was found on diamond films nucleation side after detachment. It suggested that MoC was peeled off from Mo substrate. The stable Mo2C on Mo substrate was formed after multi-time use of Mo substrate. However, MoC has not been found on it. The thickness of carburizing layer on the first time used Mo substrate is up to 30µm, and the carburizing layer on the multi-time used substrate is much thicker than that on the first used. The amorphous carbon in the surface of the substrate and nucleation side of diamond films was found by XPS, including for the first time used and multi-time used substrate.

scholarly journals Infant Strangulation from an Amber Teething Necklace

CJEM ◽  
2016 ◽  
Vol 19 (5) ◽  
pp. 400-403 ◽  
Author(s):  
Catherine Cox ◽  
Neil Petrie ◽  
Katrina F. Hurley
Keyword(s):  
Time Use ◽  
Professional Organizations ◽  
Infants And Toddlers ◽  
Aspiration Risk ◽  
Health Canada ◽  
First Time

AbstractAmber teething necklaces supposedly provide analgesia for teething infants. Their use is becoming more widespread, despite lack of peer-reviewed evidence and warnings from Health Canada that they pose a strangulation and aspiration risk. To date, there have been no published reports of strangulation secondary to amber teething necklaces. In this report we present a case of non-fatal infant strangulation from the first time use of an amber teething necklace. We will also discuss the role of physicians as advocates in reporting similar cases and educating families. Finally, we will comment on the responsibility of all professionals and professional organizations that work with infants and toddlers to advocate for children by raising concerns and counselling parents.

scholarly journals Timing of First-Time use of Biologics and Healthcare Costs and Utilization in Psoriasis

2015 ◽  
Vol 18 (3) ◽  
pp. A296
Author(s):  
S.R. Feldman ◽  
V. Herrera ◽  
Y. Zhao ◽  
L. Shi
Keyword(s):  
Time Use ◽  
Healthcare Costs ◽  
First Time

Mid-Holocene Climate and Culture Change in the Atacama Desert, Northern Chile

1997 ◽  
Vol 48 (2) ◽  
pp. 239-246 ◽  
Author(s):  
Martin Grosjean ◽  
Lautaro Núñez ◽  
Isabel Cartajena ◽  
Bruno Messerli
Keyword(s):  
Atacama Desert ◽  
Cultural Tradition ◽  
Northern Chile ◽  
Late Archaic ◽  
Human Occupation ◽  
Rainfall Events ◽  
Adaptive Process ◽  
Early Archaic ◽  
First Time ◽  
Heavy Rainfall Events

AbstractTwenty archaeological campsites intercalated between more than 30 debris flows caused by heavy rainfall events between 6200 and 3100 14C yr B.P. have recently been discovered at Quebrada Puripica in the Atacama Desert of northern Chile. This record provides detailed information about extreme, short-lived climatic events during the hyperarid mid-Holocene period. For the first time, we found evidence of continuous human occupation in this area, filling the regional hiatus in the Atacama basin (“Silencio Arqueologico”) between 8000 and 4800 14C yr B.P. The transformation of Early Archaic hunters into the complex Late Archaic cultural tradition was an adaptive process. During this time, the site was a local ecological refuge with abundant resources in a generally hostile environment.

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