The Carboniferous timescale: an introduction

2021 ◽  
pp. SP512-2021-160
Author(s):  
Spencer G. Lucas ◽  
Joerg W. Schneider ◽  
Svetlana Nikolaeva ◽  
Xiandong Wang
Keyword(s):  
Early Stage ◽  
Magnetic Polarity ◽  
Future Research ◽  
Global Correlation ◽  
O Isotopes ◽  
Isotope Stratigraphy ◽  
C And O Isotopes ◽  
Selection For ◽  
Further Development

AbstractThe Carboniferous chronostratigraphic scale consists of two subsystems, six series and seven stages. Precise numerical age control within the Carboniferous is uneven, and a global magnetic polarity timescale for the Carboniferous is far from established. Isotope stratigraphy based on Sr, C and O isotopes is in an early stage but has already identified a few Sr and C isotope events of use to global correlation. Cyclostratigraphy has created a workable astrochronology for part of Pennsylvanian time that needs better calibration. Chronostratigraphic definitions of most of the seven Carboniferous stages remain unfinished. Future research on the Carboniferous timescale should focus on GSSP selection for the remaining, undefined stage bases, definition and characterization of substages, and further development and integration of the Carboniferous chronostratigraphic scale with radioisotopic, magnetostratigraphic, chemostratigraphic and cyclostratigraphic tools for calibration and correlation and the cross correlation of nonmarine and marine chronologies.

scholarly journals Carbon and Oxygen Isotopic Composition of Saline Lacustrine Dolomite Cements and Its Palaeoenvironmental Significance: A Case Study of Paleogene Shahejie Formation, Bohai Sea

Minerals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 13 ◽  
Author(s):  
Hailong Meng ◽  
Zhengxiang Lv ◽  
Zhongmin Shen ◽  
Chenhao Xiong
Keyword(s):  
Early Stage ◽  
Oxygen Isotopic Composition ◽  
Lake Basin ◽  
Bohai Bay ◽  
O Isotopes ◽  
Shahejie Formation ◽  
Oxygen Isotopic ◽  
C And O Isotopes ◽  
Two Stages ◽  
Saline Lacustrine

The dolomite reservoirs in the Paleogene Shahejie Formation in the Bozhong area of the Bohai Bay Basin contain a large amount of dolomite cement. Petrologic and mineralogic studies have shown that the dolomite cements can be divided into three types according to their occurrence: coating dolomite (CD), pore-lining dolomite (LD), and pore-filling dolomite (FD). The laser microsampling technique was used to analyze the C and O isotopes in the carbonate minerals. This method is an effective way to produce CO2 gas from a particular carbonate structure in a thin section, and it has a spatial resolution of 20–50 µm and an optimal precision of approximately ±0.22σ for δ13C and δ18O in carbonate standard materials. The carbon and oxygen isotopic compositions and the oxygen isotopic geothermometer results showed that the dolomitization fluid is mainly low temperature fluid, the lake basin environment is relatively closed, and the salinity index Z value is greater than 120, which indicates the invasion of seawater. CD and early-stage LD crystals were mainly very fine crystals with faint cathodoluminescence, which indicates the early formation of diagenesis. The high temperatures of late-stage LD and FD measured by oxygen isotope thermometers indicates that they formed at a deeper depth. The dolomite cements in the study area may have formed in two stages: seepage-reflux dolomitization during the penecontemporaneous period and burial dolomitization.

The microbiome of the digestive system of ruminants – a review

2020 ◽  
Vol 21 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Paulina Cholewińska ◽  
Katarzyna Czyż ◽  
Piotr Nowakowski ◽  
Anna Wyrostek
Keyword(s):  
Feed Efficiency ◽  
Digestive System ◽  
Gradual Increase ◽  
Early Stage ◽  
Future Research ◽  
Main Step ◽  
Factors Affecting ◽  
To Come ◽  
The Relationship

AbstractThis review aims to explain the influence and characterization of the microbiome in the ruminant digestive system by presenting the knowledge collected so far. The knowledge presented in this work is focused on the main factors affecting the microbiome and the main dependencies that have been found in it so far. The microbiome in the rumen is the first to come into contact with the biomass of the forage and its main purpose is to decompose into smaller particles or compounds. With the gradual increase in knowledge about the microbiome, there is a chance to manipulate it so that the animal continues to live in a symbiotic relationship with it, while reducing greenhouse gas emissions to the environment as well as increasing feed efficiency. Therefore, understanding the influence of the ruminant microbiome is the main step to achieve such results. However, learning the relationship between microorganisms is only at an early stage, because research focuses mainly on taxonomy. Future research should focus on interactions in the ecosystem which is the microbiome, on explaining individual functions and on influence of environmental factors.

Parasite defense mechanisms in bees: behavior, immunity, antimicrobials, and symbionts

2019 ◽  
Vol 4 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Alison E. Fowler ◽  
Rebecca E. Irwin ◽  
Lynn S. Adler
Keyword(s):  
Defense Mechanisms ◽  
Poor Quality ◽  
Future Research ◽  
Immune Priming ◽  
Social Bees ◽  
Bee Health ◽  
Landscape Scales ◽  
And Function ◽  
Solitary Species

Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management.

scholarly journals Characterization of M dwarfs using optical mid-resolution spectra for exploration of small exoplanets

2020 ◽  
Author(s):  
Yohei Koizumi ◽  
Masayuki Kuzuhara ◽  
Masashi Omiya ◽  
Teruyuki Hirano ◽  
John Wisniewski ◽  
...  
Keyword(s):  
Sample Selection ◽  
Optical Spectra ◽  
Average Error ◽  
Spectral Energy ◽  
M Dwarfs ◽  
Energy Distributions ◽  
Fitting Procedures ◽  
Optical Region ◽  
Selection For

Abstract We present the optical spectra of 338 nearby M dwarfs, and compute their spectral types, effective temperatures (Teff), and radii. Our spectra were obtained using several optical spectrometers with spectral resolutions that range from 1200 to 10000. As many as 97% of the observed M-type dwarfs have a spectral type of M3–M6, with a typical error of 0.4 subtype, among which the spectral types M4–M5 are the most common. We infer the Teff of our sample by fitting our spectra with theoretical spectra from the PHOENIX model. Our inferred Teff is calibrated with the optical spectra of M dwarfs whose Teff have been well determined with the calibrations that are supported by previous interferometric observations. Our fitting procedures utilize the VO absorption band (7320–7570 Å) and the optical region (5000–8000 Å), yielding typical errors of 128 K (VO band) and 85 K (optical region). We also determine the radii of our sample from their spectral energy distributions. We find most of our sample stars have radii of <0.6 R⊙, with the average error being 3%. Our catalog enables efficient sample selection for exoplanet surveys around nearby M-type dwarfs.

A Taxonomy for Psycho-Oncological Intervention Techniques in an Acute Care Hospital in Germany

2021 ◽  
pp. 1-7
Author(s):  
Martina Madl ◽  
Marietta Lieb ◽  
Katharina Schieber ◽  
Tobias Hepp ◽  
Yesim Erim
Keyword(s):  
Acute Care ◽  
Interrater Reliability ◽  
Acute Care Hospital ◽  
Future Research ◽  
Systematic Research ◽  
Care Hospital ◽  
Certification System ◽  
Stepwise Procedure ◽  
Further Development

<b><i>Background:</i></b> Due to the establishment of a nationwide certification system for cancer centers in Germany, the availability of psycho-oncological services for cancer patients has increased substantially. However, little is known about the specific intervention techniques that are applied during sessions in an acute care hospital, since a standardized taxonomy is lacking. With this study, we aimed at the investigation of psycho-oncological intervention techniques and the development of a comprehensive and structured taxonomy thereof. <b><i>Methods:</i></b> In a stepwise procedure, a team of psycho-oncologists generated a data pool of interventions and definitions that were tested in clinical practice during a pilot phase. After an adaptation of intervention techniques, interrater reliability (IRR) was attained by rating 10 previously recorded psycho-oncological sessions. A classification of interventions into superordinate categories was performed, supported by cluster analysis. <b><i>Results:</i></b> Between April and June 2017, 980 psycho-oncological sessions took place. The experts agreed on a total number of 22 intervention techniques. An IRR of 89% for 2 independent psycho-oncological raters was reached. The 22 techniques were classified into 5 superordinate categories. <b><i>Discussion/Conclusion:</i></b> We developed a comprehensive and structured taxonomy of psycho-oncological intervention techniques in an acute care hospital that provides a standardized basis for systematic research and applied care. We expect our work to be continuously subjected to further development: future research should evaluate and expand our taxonomy to other contexts and care settings.

scholarly journals Crowdsourcing and open innovation: a systematic literature review, an integrated framework and a research agenda

2021 ◽  
Author(s):  
Livio Cricelli ◽  
Michele Grimaldi ◽  
Silvia Vermicelli
Keyword(s):  
Literature Review ◽  
Systematic Literature Review ◽  
Open Innovation ◽  
Innovation Management ◽  
Academic Research ◽  
Future Research ◽  
Four Dimensions ◽  
Word Analysis ◽  
The Relationship

AbstractIn recent years, Open Innovation (OI) and crowdsourcing have been very popular topics in the innovation management literature, attracting significant interest and attention, and inspiring a rich production of publications. Although these two topics share common themes and address similar managerial challenges, to the best of our knowledge, there is no systematic literature review that digs deep into the intersection of both fields. To fill in this gap a joint review of crowdsourcing and OI topics is both timely and of interest. Therefore, the main objective of this study is to carry out a comprehensive, systematic, and objective review of academic research to help shed light on the relationship between OI and crowdsourcing. For this purpose, we reviewed the literature published on these two topics between 2008 and 2019, applying two bibliometric techniques, co-citation and co-word analysis. We obtained the following results: (i) we provide a qualitative analysis of the emerging and trending themes, (ii) we discuss a characterization of the intersection between OI and crowdsourcing, identifying four dimensions (strategic, managerial, behavioral, and technological), (iii) we present a schematic reconceptualization of the thematic clusters, proposing an integrated view. We conclude by suggesting promising opportunities for future research.

scholarly journals Current hurdles to the translation of nanomedicines from bench to the clinic

2021 ◽  
Author(s):  
Snežana Đorđević ◽  
María Medel Gonzalez ◽  
Inmaculada Conejos-Sánchez ◽  
Barbara Carreira ◽  
Sabina Pozzi ◽  
...  
Keyword(s):  
Drug Product ◽  
Early Stage ◽  
Regulatory Agencies ◽  
Important Process ◽  
Close Collaboration ◽  
Critical Quality Attributes ◽  
Research Areas ◽  
Physical Chemical ◽  
Clinical Models ◽  
Further Development

AbstractThe field of nanomedicine has significantly influenced research areas such as drug delivery, diagnostics, theranostics, and regenerative medicine; however, the further development of this field will face significant challenges at the regulatory level if related guidance remains unclear and unconsolidated. This review describes those features and pathways crucial to the clinical translation of nanomedicine and highlights considerations for early-stage product development. These include identifying those critical quality attributes of the drug product essential for activity and safety, appropriate analytical methods (physical, chemical, biological) for characterization, important process parameters, and adequate pre-clinical models. Additional concerns include the evaluation of batch-to-batch consistency and considerations regarding scaling up that will ensure a successful reproducible manufacturing process. Furthermore, we advise close collaboration with regulatory agencies from the early stages of development to assure an aligned position to accelerate the development of future nanomedicines. Graphical abstract

scholarly journals Hyperinsulinemia and Its Pivotal Role in Aging, Obesity, Type 2 Diabetes, Cardiovascular Disease and Cancer

2021 ◽  
Vol 22 (15) ◽  
pp. 7797
Author(s):  
Joseph A. M. J. L. Janssen
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Cardiovascular Disease ◽  
Insulin Secretion ◽  
Early Stage ◽  
Insulin Clearance ◽  
Future Research ◽  
Age Related ◽  
Hepatic Insulin Clearance

For many years, the dogma has been that insulin resistance precedes the development of hyperinsulinemia. However, recent data suggest a reverse order and place hyperinsulinemia mechanistically upstream of insulin resistance. Genetic background, consumption of the “modern” Western diet and over-nutrition may increase insulin secretion, decrease insulin pulses and/or reduce hepatic insulin clearance, thereby causing hyperinsulinemia. Hyperinsulinemia disturbs the balance of the insulin–GH–IGF axis and shifts the insulin : GH ratio towards insulin and away from GH. This insulin–GH shift promotes energy storage and lipid synthesis and hinders lipid breakdown, resulting in obesity due to higher fat accumulation and lower energy expenditure. Hyperinsulinemia is an important etiological factor in the development of metabolic syndrome, type 2 diabetes, cardiovascular disease, cancer and premature mortality. It has been further hypothesized that nutritionally driven insulin exposure controls the rate of mammalian aging. Interventions that normalize/reduce plasma insulin concentrations might play a key role in the prevention and treatment of age-related decline, obesity, type 2 diabetes, cardiovascular disease and cancer. Caloric restriction, increasing hepatic insulin clearance and maximizing insulin sensitivity are at present the three main strategies available for managing hyperinsulinemia. This may slow down age-related physiological decline and prevent age-related diseases. Drugs that reduce insulin (hyper) secretion, normalize pulsatile insulin secretion and/or increase hepatic insulin clearance may also have the potential to prevent or delay the progression of hyperinsulinemia-mediated diseases. Future research should focus on new strategies to minimize hyperinsulinemia at an early stage, aiming at successfully preventing and treating hyperinsulinemia-mediated diseases.

Ferrous materials degradation: characterisation of rust by colour – an overview

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Desmond E. P. Klenam ◽  
Michael O. Bodunrin ◽  
Stefania Akromah ◽  
Emmanuel Gikunoo ◽  
Anthony Andrews ◽  
...  
Keyword(s):  
Yellow Rust ◽  
Brown Rust ◽  
Future Research ◽  
Stable Form ◽  
Low Oxygen ◽  
High Moisture ◽  
Oxygen Environment ◽  
Causative Factors ◽  
Analytical Tools

Abstract An overview of the characterisation of rust by colour is presented. Each distinct rust colour is caused by atmospheric impurities, high or low moisture content and high or low oxygen environment over time. Yellow rust is mainly due to the high moisture environment over a period of time, which drips. Brown rust is dry, crusty and due to water and oxygen contact with localised patches on component surfaces. Black rust, the most stable form, occurs in low moisture and low oxygen environment. The rust residue shows where the reaction started, especially in contact with chlorides. The causative factors of red rust are atmospheric and similar to black rust in a chloride-containing environment. The effect of packaging, manufacturing and environmental factors on rust colour is briefly discussed. Visual characterization of rust could pre-empt root causes and analytical tools for validation. The limitations of these concepts are mentioned and directions for future research highlighted.

Sign in / Sign up

Export Citation Format

Share Document