scholarly journals Effect of terrigenous sediments on macroalgae functional-form groups of coral reefs in Capurganá, Colombian Caribbean

2021 ◽  
Vol 85 (2) ◽  
pp. 125-135
Author(s):  
Ibis Tarini López-Jiménez ◽  
Lizette Irene Quan-Young ◽  
Lennin Florez-Leiva
Keyword(s):  
Coral Reefs ◽  
Coralline Algae ◽  
In Situ Experiment ◽  
Terrigenous Sediments ◽  
Current State ◽  
Wide Range ◽  
Key Factor ◽  
Negative Effect ◽  
Sediment Addition ◽  
The Impact

Increased sedimentation in the marine environment has been described as a key factor in the degradation of coral reefs. One of the most important biological components of coral reefs is macroalgae. The objective of this study was to determine whether the effects of terrigenous sediments on macroalgae affect the current state of the coral reef ecosystem. In an in situ experiment in Capurganá Bay, terrigenous sediments were added to artificial plates and the impact on the recruitment and growth of the macroalgae was examined. In this experiment, three treatments were used: sediment addition and two natural conditions, one up to 10 m distance from the sediment addition (control 1) and one between 15 and 20 m distance from the sediment addition (control 2). The results indicated a high complexity and variability in the response of reef algae to the effects of sedimentation depending on the sediment grade size deposited. The addition had a positive effect on the recruitment and growth of filamentous algae, primarily red algae, whereas it had a negative effect on coralline algae. The sediments found on the plates did not significantly change the macroalgal structure (P>0.05). However, a trend was observed in the change of the algal cover in each treatment. These results indicate that there is a wide range of response of the algae depending on the functional groups and the nature of the sediment.

scholarly journals Climate-dependent propagation of precipitation uncertainty into the water cycle

2020 ◽  
Author(s):  
Ali Fallah ◽  
Sungmin O ◽  
Rene Orth
Keyword(s):  
Hydrological Model ◽  
Water Cycle ◽  
State Of The Art ◽  
Rain Gauge ◽  
Multiple Sources ◽  
Current State ◽  
Wide Range ◽  
The Impact ◽  
Conceptual Hydrological Model

Abstract. Precipitation is a crucial variable for hydro-meteorological applications. Unfortunately, rain gauge measurements are sparse and unevenly distributed, which substantially hampers the use of in-situ precipitation data in many regions of the world. The increasing availability of high-resolution gridded precipitation products presents a valuable alternative, especially over gauge-sparse regions. Nevertheless, uncertainties and corresponding differences across products can limit the applicability of these data. This study examines the usefulness of current state-of-the-art precipitation datasets in hydrological modelling. For this purpose, we force a conceptual hydrological model with multiple precipitation datasets in > 200 European catchments. We consider a wide range of precipitation products, which are generated via (1) interpolation of gauge measurements (E-OBS and GPCC V.2018), (2) combination of multiple sources (MSWEP V2) and (3) data assimilation into reanalysis models (ERA-Interim, ERA5, and CFSR). For each catchment, runoff and evapotranspiration simulations are obtained by forcing the model with the various precipitation products. Evaluation is done at the monthly time scale during the period of 1984–2007. We find that simulated runoff values are highly dependent on the accuracy of precipitation inputs, and thus show significant differences between the simulations. By contrast, simulated evapotranspiration is generally much less influenced. The results are further analysed with respect to different hydro-climatic regimes. We find that the impact of precipitation uncertainty on simulated runoff increases towards wetter regions, while the opposite is observed in the case of evapotranspiration. Finally, we perform an indirect performance evaluation of the precipitation datasets by comparing the runoff simulations with streamflow observations. Thereby, E-OBS yields the best agreement, while furthermore ERA5, GPCC V.2018 and MSWEP V2 show good performance. In summary, our findings highlight a climate-dependent propagation of precipitation uncertainty through the water cycle; while runoff is strongly impacted in comparatively wet regions such as Central Europe, there are increasing implications on evapotranspiration towards drier regions.

scholarly journals Some results of studying the impact of digital technologies upon learning activities

2020 ◽  
pp. 1-14
Author(s):  
Elvira Vitaljevna Burtseva ◽  
Olga Chepak ◽  
Olga Kulikova
Keyword(s):  
Higher Education ◽  
Social Networks ◽  
Negative Impact ◽  
Digital Technologies ◽  
Educational Process ◽  
Learning Activities ◽  
Key Factor ◽  
Negative Effect ◽  
The Subject ◽  
The Impact

The subject of this research is the implementation of digital technologies in educational process of a university. The goal consists in studying the impact of digital technologies upon the students’ learning activities. The article presents the results of questionnaire-based survey among students by the three question pools. In the course of research, the author examines such aspects of the problem, as the positive and negative impact of technologies upon learning activities of the students of digital generation. Particular attention is given to consideration of students’ attitude on digitalization of higher education. The opinions of pedagogues on the results of conducted research are presented. The scientific novelty lies in mainstreaming the question on the negative impact of digital technologies upon learning activities of the modern generation of students that deserves special attention. On the background of common passion of the scholars of researchers and pedagogues for the ideas of digitalization of education, when digital technologies are viewed as virtually the key factor for modernization of educational process; second come the problems of growing pathological dependence of youth on digital technologies, undesired to switch to digitalized educational process to the disadvantage of communication in social networks and pleasant pastime online. The problem of the negative effect of digital technologies on learning activities must be recognized in order to find the ways for its solution.

scholarly journals The hidden army: corallivorous crown-of-thorns seastars can spend years as herbivorous juveniles

2020 ◽  
Vol 16 (4) ◽  
pp. 20190849 ◽  
Author(s):  
Dione J. Deaker ◽  
Antonio Agüera ◽  
Huang-An Lin ◽  
Corinne Lawson ◽  
Claire Budden ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Exponential Growth ◽  
Black Box ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Major Threat ◽  
Asymptotic Size ◽  
The Impact

Crown-of-thorns seastar (COTS) outbreaks are a major threat to coral reefs. Although the herbivorous juveniles and their switch to corallivory are key to seeding outbreaks, they remain a black box in our understanding of COTS. We investigated the impact of a delay in diet transition due to coral scarcity in cohorts reared on crustose coralline algae for 10 months and 6.5 years before being offered coral. Both cohorts achieved an asymptotic size (16–18 mm diameter) on algae and had similar exponential growth on coral. After 6.5 years of herbivory, COTS were competent coral predators. This trophic and growth plasticity results in a marked age–size disconnect adding unappreciated complexity to COTS boom–bust dynamics. The potential that herbivorous juveniles accumulate in the reef infrastructure to seed outbreaks when favourable conditions arise has implications for management of COTS populations.

scholarly journals Internal R&D and Acquisition Performance of Chinese Pharmaceutical Firms: Moderation Effect of Acquisition Motive and Corporate Ownership

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 292 ◽  
Author(s):  
Qi Yue ◽  
Xing Hua ◽  
Jianyuan Li
Keyword(s):  
Path Dependence ◽  
Corporate Ownership ◽  
Acquisition Performance ◽  
Moderation Effect ◽  
Pharmaceutical Firms ◽  
Key Factor ◽  
Negative Effect ◽  
The Impact ◽  
The Relationship

Although corporate capability has been recognized as a key factor affecting corporate acquisition performance, the role of R&D capability in acquisition performance has not been fully explained. The aim of this paper was to research the impact of internal R&D on acquisition performance according to a sample of 215 acquisitions of Chinese listed pharmaceutical companies from 2012 to 2016. First, it was found that R&D has a significant negative effect on acquisition performance. Furthermore, it was confirmed that the acquisition motive and the ownership of the acquiring firm have a moderating effect on the relationship between R&D and acquisition performance. Compared to non-technical acquisitions, the negative effect of internal R&D on acquisition performance was reduced for technical acquisitions. Compared with non-state-owned-enterprise acquisition, the negative effect of internal R&D on the acquisition performance of state-owned enterprises was weakened. Our study enriches the research of the path dependence theory on the acquisition performance of enterprises and also the interpretation of acquisition performance on the basis of internal and external innovation and the institutional theory.

scholarly journals Speech synthesis systems: disadvantages and limitations

2018 ◽  
Vol 7 (2.28) ◽  
pp. 234 ◽  
Author(s):  
Karolina Kuligowska ◽  
Paweł Kisielewicz ◽  
Aleksandra Włodarz
Keyword(s):  
Text Analysis ◽  
Speech Synthesis ◽  
Analysis Problem ◽  
Current State ◽  
Wide Range ◽  
Current Classification ◽  
Weak Points ◽  
The Impact ◽  
Further Development ◽  
Insight Into

The present speech synthesis systems can be successfully used for a wide range of diverse purposes. However, there are serious and important limitations in using various synthesizers. Many of these problems can be identified and resolved. The aim of this paper is to present the current state of development of speech synthesis systems and to examine their drawbacks and limitations. The paper dis-cusses the current classification, construction and functioning of speech synthesis systems, which gives an insight into synthesizers implemented so far. The analysis of disadvantages and limitations of speech synthesis systems focuses on identification of weak points of these systems, namely: the impact of emotions and prosody, spontaneous speech in terms of naturalness and intelligibility, preprocessing and text analysis, problem of ambiguity, natural sounding, adaptation to the situation, variety of systems, sparsely spoken languages, speech synthesis for older people, and some other minor limitations. Solving these problems stimulates further development of speech synthesis domain. 

scholarly journals Production of Adenosine by Ectonucleotidases: A Key Factor in Tumor Immunoescape

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
François Ghiringhelli ◽  
Mélanie Bruchard ◽  
Fanny Chalmin ◽  
Cédric Rébé
Keyword(s):  
Immune Response ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Stromal Cells ◽  
T Cell Response ◽  
Antitumor Immune Response ◽  
Tumor Bed ◽  
Wide Range ◽  
Key Factor ◽  
The Impact

It is now well known that tumor immunosurveillance contributes to the control of cancer growth. Many mechanisms can be used by cancer cells to avoid the antitumor immune response. One such mechanism relies on the capacity of cancer cells or more generally of the tumor microenvironment to generate adenosine, a major molecule involved in antitumor T cell response suppression. Adenosine is generated by the dephosphorylation of extracellular ATP released by dying tumor cells. The conversion of ATP into adenosine is mediated by ectonucleotidase molecules, namely, CD73 and CD39. These molecules are frequently expressed in the tumor bed by a wide range of cells including tumor cells, regulatory T cells, Th17 cells, myeloid cells, and stromal cells. Recent evidence suggests that targeting adenosine by inhibiting ectonucleotidases may restore the resident antitumor immune response or enhance the efficacy of antitumor therapies. This paper will underline the impact of adenosine and ectonucleotidases on the antitumor response.

scholarly journals The Impact of Atopic Dermatitis on Quality of Life

2015 ◽  
Vol 66 (Suppl. 1) ◽  
pp. 34-40 ◽  
Author(s):  
Carlos Lifschitz
Keyword(s):  
Quality Of Life ◽  
Atopic Dermatitis ◽  
Skin Diseases ◽  
Well Being ◽  
Broad Concept ◽  
Wide Range ◽  
Health Related Qol ◽  
Negative Effect ◽  
The Impact

Approximately 5-20% of children worldwide suffer from atopic dermatitis (AD), a kind of dermatitis characterized as an inflammatory, relapsing, noncontagious and itchy skin disorder. Children often develop AD during their first year of life. An increased rate of sensitization to both food and aeroallergens has been shown to coexist in patients with AD. Sensitization to well-known allergens such as cow's milk protein can occur on average in 50% of children with AD. In general, quality of life (QoL) is perceived as the quality of an individual's daily life, that is, an assessment of their well-being or lack thereof. QoL is a broad concept that includes such things as standard of living, community, and family life. Patients with skin diseases experience a wide range of symptoms ranging from trivial problems to major handicaps which affect their lives. The misery of living with AD cannot be overstated for it may have a profoundly negative effect on the health-related QoL of children and their families in many cases. Physicians taking care of children with AD should consult parents on how their child's illness has impacted their lifestyle and recommend professional intervention if deemed necessary.

scholarly journals A possible link between coral reef success, crustose coralline algae and the evolution of herbivory

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sebastian Teichert ◽  
Manuel Steinbauer ◽  
Wolfgang Kiessling
Keyword(s):  
Coral Reefs ◽  
Coralline Algae ◽  
Time Interval ◽  
Crustose Coralline Algae ◽  
Coralline Red Algae ◽  
Potential Capacity ◽  
Morphological Adaptations ◽  
Geological Past ◽  
Tropical Coral ◽  
Negative Effect

Abstract Crustose coralline red algae (CCA) play a key role in the consolidation of many modern tropical coral reefs. It is unclear, however, if their function as reef consolidators was equally pronounced in the geological past. Using a comprehensive database on ancient reefs, we show a strong correlation between the presence of CCA and the formation of true coral reefs throughout the last 150 Ma. We investigated if repeated breakdowns in the potential capacity of CCA to spur reef development were associated with sea level, ocean temperature, CO2 concentration, CCA species diversity, and/or the evolution of major herbivore groups. Model results show that the correlation between the occurrence of CCA and the development of true coral reefs increased with CCA diversity and cooler ocean temperatures while the diversification of herbivores had a transient negative effect. The evolution of novel herbivore groups compromised the interaction between CCA and true reef growth at least three times in the investigated time interval. These crises have been overcome by morphological adaptations of CCA.

scholarly journals Changing the game: a case for gamifying knowledge management

2017 ◽  
Vol 14 (2/3) ◽  
pp. 143-154 ◽  
Author(s):  
Agnessa Shpakova ◽  
Viktor Dörfler ◽  
Jill MacBryde
Keyword(s):  
Knowledge Management ◽  
Literature Review ◽  
Knowledge Workers ◽  
Content Type ◽  
Collaborative Environment ◽  
Current State ◽  
Starting Point ◽  
Wide Range ◽  
The Impact ◽  
A Company

Purpose This exploratory paper investigates gamification as a medium for knowledge workers to interact with each other. The purpose of this paper is to open the discussion around the sustaining impact that gamification might have on knowledge management (KM). Design/methodology/approach The paper employs an exploratory literature review investigating the current state of the art in relation to KM and gamification; this literature review serves as the starting point of subsequent theorizing. Findings Based on the literature review the authors theorize that the use of gamification in KM can go far beyond the motivational aspects. To name just a few uses of gamification, it can help in: supporting flexibility, facilitating transparency and therefore improving trust, visualizing skills and competences as well as generating requirements for new competences and promoting a collaborative environment among the knowledge workers. Research limitations/implications This paper opens the discussion around KM and gamification and suggests a wide range of areas for further research. Practical implications In this paper the authors argue that by looking at gamification as more than just a set of tools for improving motivation and engagement a company can address some pitfalls of a particular type of knowledge workers. Originality/value Gamification is a new, but increasingly popular approach, which has been shown to be powerful in many areas. This paper is novel in that it initiates a dialogue around the impact that gamification might have on KM.

Identification of Fragile Microscopic Structures during Mineral Transformations in Wet Supercritical CO2

2013 ◽  
Vol 19 (2) ◽  
pp. 268-275 ◽  
Author(s):  
Bruce W. Arey ◽  
Libor Kovarik ◽  
Odeta Qafoku ◽  
Zheming Wang ◽  
Nancy J. Hess ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Water Content ◽  
Ion Beam ◽  
Magnesium Carbonate ◽  
Interfacial Structure ◽  
Reaction Products ◽  
Wide Range ◽  
Key Factor ◽  
Mineral Transformations ◽  
The Impact

AbstractThis study examines the nature of highly fragile reaction products that form in low water content supercritical carbon dioxide (scCO2) using a combination of focus ion beam/scanning electron microscopy, confocal Raman spectroscopy, helium ion microscopy (HeIM), and transmission electron microscopy (TEM). HeIM images show these precipitates are fragile rosettes. Using the TEM revealed details on the interfacial structure between the newly formed surface precipitates and the underlying initial solid phases. Detailed microscopy analysis revealed that growth of the precipitates either followed a tip growth mechanism, with precipitates forming directly on the forsterite surface if the initial solid was nonporous (natural forsterite) or growth from the surface of the precipitates, where fluid was conducted through the porous (nanoforsterite) agglomerates to the growth center. Identification of the mechanism of formation of hydrated/hydroxylated magnesium carbonate compound phases is a key factor in unraveling the impact of water recycling on mineral reactivity in low water content scCO2 solutions, which has received a great deal of attention as a result of the potential for CO2 to act as an atmospheric greenhouse gas. Techniques used here to examine these fragile structures are also used to examine a wide range of fragile material surfaces.

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