Bryozoan-rich stromatolites (“bryoliths”) from the Silurian of Gotland and their relation to climate-related perturbations of the carbon cycle

2020 ◽  
Author(s):  
Anna Lene Claussen ◽  
Axel Munnecke ◽  
Andrej Ernst
Keyword(s):  
Stable Isotope ◽  
Carbon Cycle ◽  
High Abundance ◽  
Common Features ◽  
Fossil Remains ◽  
Reef Type ◽  
Environmental Requirements ◽  
Favorable Conditions ◽  
Microbial Crusts

<p>A small but rather unique reef type occurs in the Silurian of Gotland mainly composed of encrusting bryozoans and microbial crusts, forming a complex intergrowth, which can be characterized as bryozoan-rich stromatolites, so-called “bryoliths”. The alternation of bryozoans and microbes is assumingly driven by a repeated change of hostile and more favorable conditions for metazoan growth. The surfaces of the reef bodies are composed of characteristic cauliflower structures, created by bryozoans, which are performing a finger-like growth in every direction. Other common features are bioerosion (mostly by bivalves), enigmatic encrusting echinoderms, a high abundance of organophosphatic fossil remains such as bryozoan pearls and discinid brachiopods, a high abundance of epi- and endobionts, vadose silt, and gypsum pseudomorphs.</p><p>Altogether, ten of these special reefs have been identified on Gotland so far. All of them were formed during periods of strong positive δ <sup>13</sup>C excursions at the Ireviken and Lau isotope excursions in the early Wenlock and late Ludlow, respectively. The unusual features of the bryoliths as well as their occurrence exclusively during strong positive δ <sup>13</sup>C excursions indicate very specific environmental requirements. This leads to the assumption, that whatever caused the isotope excursions also has affected these reef systems. Hence, investigating the bryoliths will hopefully increase our knowledge to what has happened during the – still enigmatic – Silurian stable isotope excursions.</p>

Automated reverse engineering control system model

2020 ◽  
pp. 39-43
Author(s):  
A. V. Vinnichenko ◽  
S. A. Nazarevich ◽  
I. R. Karpova
Keyword(s):  
Control System ◽  
Reverse Engineering ◽  
Flaw Detection ◽  
Production Capacity ◽  
Speed Up ◽  
Environmental Requirements ◽  
Traditional Technologies ◽  
The Moment ◽  
Control System Model ◽  
Favorable Conditions

The article deals with the task of simplifying the reverse design process by implementing three-point 3D scanning, which allows you to speed up the technological stages of reverse design to the moment of product manufacture, as well as simplify the procedure for defecating finished products and create favorable conditions for the implementation of the principles of unification. The model of the control system in this article refers to the structuring of elements of the technological organization of the process of creating 3D prototyping of existing copies created by the use of reverse engineering. For this purpose, the problems of traditional technologies that do not allow timely coping with changes in the technical system under the influence of in accordance with the requirements of regulatory documents and environmental requirements were considered. We also analyzed not only the principles of operation of traditional technologies, but also the zone of reverse engineering, which allows you to achieve an increased level of production capacity by identifying a group of key defects based on the process of flaw detection and statistical analysis.

scholarly journals Variación en la abundancia de árboles maderables por efecto de borde en un bosque tropical subcaducifolio

2019 ◽  
Vol 97 (1) ◽  
pp. 35 ◽  
Author(s):  
Víctor Abraham Vargas-Vázquez ◽  
Crystian Sadiel Venegas-Barrera ◽  
Arturo Mora-Olivo ◽  
José Guadalupe Martínez-Ávalos ◽  
Eduardo Alanís-Rodríguez ◽  
...  
Keyword(s):  
Edge Effect ◽  
Environmental Conditions ◽  
Life Stage ◽  
Life Stages ◽  
Cedrela Odorata ◽  
Economic Implications ◽  
Bursera Simaruba ◽  
Environmental Requirements ◽  
Guazuma Ulmifolia ◽  
Favorable Conditions

<p><strong>Background: </strong>The edge effect differentially affects the species in their life stages. We analyzed the environmental conditions associated with the abundance by life stage of four species of timber trees on the edge of a subdeciduous tropical forest.<strong></strong></p><p><strong>Hypothesis:</strong> The edges have higher light incidence and temperature, favorable conditions for the seedlings, so it is expected that the edge will have more abundance of seedlings with respect to the forest interior.</p><p><strong>Species under study:</strong> <em>Bursera simaruba</em> (L.) Sarg.<em>, Cedrela odorata</em> L.<em>, Guazuma ulmifolia </em>Lam.<em>, Lysiloma divaricatum </em>(Jacq.) J.F. Macbr.</p><p><strong>Study site and dates:</strong> Reserva de la Biosfera "El Cielo" (Tamaulipas), Mexico. January-December 2016.</p><p><strong>Methods: </strong>The abundance by life stages and environmental conditions were quantified within the gradient. These variables were correlated, in addition the requirements between stages were contrasted and they were associated with the identified environments.</p><p><strong>Results:</strong> <em>Guazuma ulmifolia</em> showed a negative response to the edge effect, while <em>Cedrela</em> <em>odorata</em> responded positively. The environmental requirements differed between the first life stages and adults. The abundance of the seedlings was associated to conditions of higher light incidence.</p><strong>Conclusions:</strong> Environmental requirements differentially affect each life stage. The abundance of seedlings increases in conditions of higher light incidence, but not in the rest of the stages, except in <em>C. odorata</em>. The loss of cover and the consequent formation of borders can lead to a reduction in the abundance of these species, with economic implications.

Onset of Oceanic Anoxic Event 2 in the Lower Saxony Basin – Insights fromhigh-resolution stable isotope stratigraphy and geochemical modelling

2021 ◽  
Author(s):  
Pia Müller ◽  
Ulrich Heimhofer ◽  
Christian Ostertag-Henning
Keyword(s):  
Organic Matter ◽  
High Resolution ◽  
Stable Isotope ◽  
Carbon Cycle ◽  
Geochemical Modelling ◽  
Positive Anomaly ◽  
Lower Saxony ◽  
Data Set ◽  
Oceanic Anoxic Event ◽  
Anoxic Event

&lt;p&gt;The Oceanic Anoxic Event (OAE) 2 spanning the Cenomanian-Turonian boundary (93.5 Ma)&lt;br&gt;represents a major perturbation of the global carbon cycle and is marked by organic-rich&lt;br&gt;sediments deposited under oxygen-depleted conditions. In many studies the eruption of the&lt;br&gt;Caribbean LIP is considered to be the cause for rapidly increasing CO2 concentrations and&lt;br&gt;resulting global warming accompanied by widespread oceanic anoxia. In the Lower Saxony&lt;br&gt;Basin of northern Germany, the deposits of the OAE 2 are exposed in several industry drill&lt;br&gt;cores. In this study, the lower part of the OAE 2 has been studied in the HOLCIM 2011-3 drill&lt;br&gt;core. Sedimentary rocks are composed of limestones, marly limestones, marls and black&lt;br&gt;shales and have been analysed with a high-resolution stable isotope approach&lt;br&gt;(approximately one sample every 2 cm) combined with geochemical modelling. Using stable&lt;br&gt;carbon isotopes, bulk rock parameters and petrographic analysis, the onset of OAE 2 has&lt;br&gt;been investigated in detail. The high-resolution &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C curve exhibits overall stable values&lt;br&gt;around 3 &amp;#8240; before the onset of the Plenus event. This background level is interrupted by&lt;br&gt;three short-lived and small but significant negative carbon isotope excursions (CIEs) down to&lt;br&gt;&amp;#948;&lt;sup&gt;13&lt;/sup&gt;C values of 2.5 &amp;#8240;, 2.7 &amp;#8240; and 1.9 &amp;#8240;. Immediately before the main rise in the Plenus bed,&lt;br&gt;a longer-lasting negative CIE down to 2.8 &amp;#8240; is observed, preceding the large positive CIE of&lt;br&gt;the OAE 2 to values of 5.2 &amp;#8240; over 33 ka. Thereafter, the &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C values decrease to 3.5 &amp;#8240; over&lt;br&gt;a period of approximately 130 ka. The results can be correlated with the lower-resolution&lt;br&gt;data set of Voigt et al. (2008) but enable a more accurate characterization of the subtle&lt;br&gt;features of the CIE and hence events before and during this time interval. Carbon cycle&lt;br&gt;modelling with the modelling software SIMILE using a model based on Kump &amp; Arthur (1999)&lt;br&gt;reveals that the negative excursion before the Plenus bed can be explained by a massive&lt;br&gt;volcanic pulse releasing of 0.95*10&lt;sup&gt;18&lt;/sup&gt; mol CO2 within 14 ka. This amount corresponds to only&lt;br&gt;81 % of the calculated volume of CO&lt;sub&gt;2&lt;/sub&gt; release during emplacement of the Caribbean LIP by&lt;br&gt;Joo et al. (2020). In the model the volcanic exhalation increases atmospheric CO&lt;sub&gt;2&lt;/sub&gt;&lt;br&gt;concentrations. This will increase global temperatures, intensify the hydrological cycle and&lt;br&gt;thus increase nutrient input into the ocean, resulting in an expansion of the oxygen minimum&lt;br&gt;zone, the development of anoxic conditions and an increase in the preservation potential for&lt;br&gt;organic material. In the model enhanced primary productivity and organic matter preservation&lt;br&gt;can be controlled by the implemented riverine phosphate input and the preservation factor for&lt;br&gt;organic matter. For the positive anomaly, the riverine phosphate input must be nearly&lt;br&gt;doubled (from 0.01 &amp;#956;mol/kg PO&lt;sub&gt;4 &lt;/sub&gt;to 0.019 &amp;#956;mol/kg) for the period of the increasing &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C&lt;br&gt;values (app. 33 ka), with a concomitant rise of the preservation factor from 1 % to 2 %. This&lt;br&gt;model scenario accurately reproduces the major features of the new high-resolution &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C&lt;br&gt;record over the onset of the OAE 2 CIE.&lt;/p&gt;

scholarly journals The Essence of the Competitiveness of Coastal Regions

2021 ◽  
Vol 1 (47) ◽  
pp. 45-51
Author(s):  
A. P. Bezkhlibna ◽  
Keyword(s):  
Coastal Region ◽  
Ecosystem Approach ◽  
Coastal Regions ◽  
Theoretical Concepts ◽  
Current State ◽  
Territorial Unit ◽  
Environmental Requirements ◽  
New Interpretation ◽  
Historical Heritage ◽  
Favorable Conditions

The article aims at defining the key theoretical concepts related to providing the competitiveness of coastal regions and studying the essence of the terms "coastal region", "competitiveness", "competitiveness of the coastal region". The features and characteristics of the coastal region are determined, the classification of the region's competitiveness is expanded, which has helped to suggest a new interpretation of the "coastal region" term. A coastal region is an administrative-territorial unit that due to its geographic position has access to the sea coast with its own waters, specializes in coastal economic and ecosystem activities, creates its own maritime complex of industries with the appropriate infrastructure, faces specific social problems and environmental requirements, has its own cultural and historical heritage, the latter reflecting the maritime theme. A binary understanding of the “coastal region” term is suggested: coastal regions are treated as oblasts and as territorial communities, the administrative boundaries of which extend to the coastline. It has been found out that the competitiveness of a coastal region is an indicator emphasizing the region's ability to respond to external challenges; ensuring the use of ecosystem approach to designing the best possible region's economic structure; overcoming seasonality in tourism and recreation; taking into account the specifics of social and environmental problems of the region; preserving the cultural and mental identity of the region to create favorable conditions for the inhabitants. To create a concept for ensuring the competitiveness of coastal regions it is necessary to make not only theoretical generalizations, but also a comprehensive diagnosis of the current state of competitiveness, which is impossible without discussing the components of competitiveness, as comprehensive assessment will be done with regard to them.

Stable isotope evidence from archived fish scales indicates carbon cycle changes over the four-decade history of the Římov Reservoir (Czechia)

2021 ◽  
Vol 755 ◽  
pp. 142550
Author(s):  
Mojmír Vašek ◽  
Allan T. Souza ◽  
Milan Říha ◽  
Jan Kubečka ◽  
Petr Znachor ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Carbon Cycle ◽  
Fish Scales ◽  
History Of ◽  
Isotope Evidence ◽  
Římov Reservoir

scholarly journals Stable isotope constraints on Holocene carbon cycle changes from an Antarctic ice core

Nature ◽  
2009 ◽  
Vol 461 (7263) ◽  
pp. 507-510 ◽  
Author(s):  
Joachim Elsig ◽  
Jochen Schmitt ◽  
Daiana Leuenberger ◽  
Robert Schneider ◽  
Marc Eyer ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Carbon Cycle ◽  
Ice Core

Modelling prehistoric land use and carbon budgets

The Holocene ◽  
2011 ◽  
Vol 21 (5) ◽  
pp. 715-722 ◽  
Author(s):  
John F. Boyle ◽  
Marie-José Gaillard ◽  
Jed O. Kaplan ◽  
John A. Dearing
Keyword(s):  
Land Use ◽  
Stable Isotope ◽  
Carbon Cycle ◽  
Information Sources ◽  
Ice Core ◽  
Population Estimates ◽  
Global Level ◽  
Early Farming ◽  
Global Population ◽  
Early Land

An evaluation of modelled estimates for C release following early land clearance at the global level based on new model assumptions suggests that earlier studies may have underestimated its magnitude, chiefly because of underestimation of the mid-Holocene global population. Alternative information sources for population and land utilisation support both a greater total CO2 release and a greater Neolithic contribution. Indeed, we show that the quantity of terrestrial C release due to early farming, even using the most conservative assumptions, greatly exceeds the net terrestrial C release estimated by inverse modelling of ice core data by Elsig et al. (Elsig J, Schmitt J, Leuenberger D, Schneider R, Eyer M, Leuenberger M et al. (2009) Stable isotope constraints on Holocene carbon cycle changes from an Antarctic ice core. Nature 461: 507–510), though uncertainty about past global population estimates precludes calculation of a precise value.

scholarly journals Temperature and light intensity interaction on Cercospora coffeicola sporulation and conidia germination

2016 ◽  
Vol 40 (2) ◽  
pp. 198-204 ◽  
Author(s):  
Marília Goulart da Silva ◽  
Edson Ampélio Pozza ◽  
Caio Vitor Rodrigues Vaz de Lima ◽  
Tales Jesus Fernandes
Keyword(s):  
Light Intensity ◽  
Significant Interaction ◽  
Limiting Factor ◽  
Dark Treatment ◽  
Different Temperatures ◽  
Cercospora Coffeicola ◽  
Environmental Requirements ◽  
Favorable Conditions ◽  
Sporulation Rate

ABSTRACT Difficulty in obtaining abundant sporulation in culture of many species of Cercospora may be the limiting factor for studies of biology, systematics, and inoculation of the genus. Therefore, it is necessary to understand the nutritional and environmental requirements that influence mycelial growth, sporulation and germination. As it is difficult to obtain conidia of Cercospora coffeicola in vitro, different temperatures (17, 22, 27, and 32 °C) and light intensities (80, 160, 240, and 320 μmol m-2 s-1) were evaluated to optimize pathogen sporulation and assess favorable conditions for spore germination, aiming for a strategy of disease control. The dark treatment (0 μmol m-2 s-1) was added for sporulation. A significant interaction was found between temperature and light intensity for both variables. The highest sporulation rate of C. coffeicola occurred at a light intensity of 240 μmol m-2 s-1 and air temperature of 22 °C, reaching 5.9x106 con mL-1. Germination was higher at temperature 17 °C and light intensity of 320 μmol m-2 s-1, reaching 52%. Interaction between light intensity and temperature proved to influence the processes of sporulation and germination of C. coffeicola.

A stable isotope toolbox for water and inorganic carbon cycle studies

2021 ◽  
Vol 2 (10) ◽  
pp. 699-719
Author(s):  
Claude Hillaire-Marcel ◽  
Sang-Tae Kim ◽  
Amaëlle Landais ◽  
Prosenjit Ghosh ◽  
Sergey Assonov ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Carbon Cycle ◽  
Inorganic Carbon ◽  
Inorganic Carbon Cycle

PROVISION OF SOIL TREATMENT TECHNOLOGIES WITH INTELLIGENT TOOLS AND CONTROL METHODS

2020 ◽  
Keyword(s):  
New Technologies ◽  
Economic Assessment ◽  
Energy Assessment ◽  
Industry Standards ◽  
Treatment Technologies ◽  
Environmental Requirements ◽  
Intelligent Tools ◽  
Almost All ◽  
Favorable Conditions ◽  
And Control

Increasing productivity in agriculture is unthinkable without the use of digital technologies based on the Internet and advanced technologies. Analysis of agrotechnical and environmental requirements for various technologies of tillage, both traditional and promising means of mechanization, shows that the timely registration, preservation and transmission of this data to the head computer requires using the most modern instruments and equipment. Devices designed for testing and operation of tillage machines and software for calculating operational and technological indicators, currently produced in small batches, meet the tasks set for them, meet the current domestic industry standards, but their high cost and narrow specialization limits their use . The use of devices is carried out during the tests of tillage equipment during technical expertise, agrotechnical and operational - technological types of assessments, during energy assessment, reliability assessment, safety and economic assessment of the structure, the use of universal controls, also used in testing almost all agricultural machinery and tractors. Similar equipment of foreign production requires knowledge of a foreign language, necessary experience with foreign computing equipment and software. Creating favorable conditions for growing crops during the entire growing season, observing all the necessary tillage techniques, including tools with elements of digital control and regulation, taking into account the physical properties of the soil, its debris, mechanical composition and erosion, predecessors and features of new technologies of cultivation, will allow to achieve high results without additional investment.

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