scholarly journals A Review of the Effect of Trace Metals on Freshwater Cyanobacterial Growth and Toxin Production

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 643 ◽  
Author(s):  
Jordan A. Facey ◽  
Simon C. Apte ◽  
Simon M. Mitrovic
Keyword(s):  
Trace Metals ◽  
Current Knowledge ◽  
Cyanobacterial Bloom ◽  
Toxin Production ◽  
Cyanobacterial Blooms ◽  
Future Research ◽  
Limiting Factor ◽  
Bloom Formation ◽  
Wide Range

Cyanobacterial blooms are becoming more common in freshwater systems, causing ecological degradation and human health risks through exposure to cyanotoxins. The role of phosphorus and nitrogen in cyanobacterial bloom formation is well documented and these are regularly the focus of management plans. There is also strong evidence that trace metals are required for a wide range of cellular processes, however their importance as a limiting factor of cyanobacterial growth in ecological systems is unclear. Furthermore, some studies have suggested a direct link between cyanotoxin production and some trace metals. This review synthesises current knowledge on the following: (1) the biochemical role of trace metals (particularly iron, cobalt, copper, manganese, molybdenum and zinc), (2) the growth limitation of cyanobacteria by trace metals, (3) the trace metal regulation of the phytoplankton community structure and (4) the role of trace metals in cyanotoxin production. Iron dominated the literature and regularly influenced bloom formation, with 15 of 18 studies indicating limitation or colimitation of cyanobacterial growth. A range of other trace metals were found to have a demonstrated capacity to limit cyanobacterial growth, and these metals require further study. The effect of trace metals on cyanotoxin production is equivocal and highly variable. Better understanding the role of trace metals in cyanobacterial growth and bloom formation is an essential component of freshwater management and a direction for future research.

scholarly journals Role of Insulin in Health and Disease: An Update

2021 ◽  
Vol 22 (12) ◽  
pp. 6403
Author(s):  
Md Saidur Rahman ◽  
Khandkar Shaharina Hossain ◽  
Sharnali Das ◽  
Sushmita Kundu ◽  
Elikanah Olusayo Adegoke ◽  
...  
Keyword(s):  
Insulin Signaling ◽  
Basic Research ◽  
Future Research ◽  
Protective Effects ◽  
Glucose Levels ◽  
Physiological Processes ◽  
Blood Glucose Levels ◽  
Wide Range ◽  
Health And Disease

Insulin is a polypeptide hormone mainly secreted by β cells in the islets of Langerhans of the pancreas. The hormone potentially coordinates with glucagon to modulate blood glucose levels; insulin acts via an anabolic pathway, while glucagon performs catabolic functions. Insulin regulates glucose levels in the bloodstream and induces glucose storage in the liver, muscles, and adipose tissue, resulting in overall weight gain. The modulation of a wide range of physiological processes by insulin makes its synthesis and levels critical in the onset and progression of several chronic diseases. Although clinical and basic research has made significant progress in understanding the role of insulin in several pathophysiological processes, many aspects of these functions have yet to be elucidated. This review provides an update on insulin secretion and regulation, and its physiological roles and functions in different organs and cells, and implications to overall health. We cast light on recent advances in insulin-signaling targeted therapies, the protective effects of insulin signaling activators against disease, and recommendations and directions for future research.

Social capital in the theory and research of LIS professionals in the light of the literature on the subject. Review of current knowledge

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Maja Dorota Wojciechowska
Keyword(s):  
Social Capital ◽  
Current Knowledge ◽  
Future Research ◽  
Content Type ◽  
Individual Social Capital ◽  
Rural Libraries ◽  
The Subject ◽  
The Moment ◽  
The Impact

Purpose The purpose of the paper is to present the latest scholarly trends in the field of social capital in libraries, to review research concepts published by LIS professionals and to suggest further research possibilities in this area. Design/methodology/approach This paper presents a review and critical analysis of literature associated with research on social capital in libraries to highlight its importance for the development of LIS and its impact on the functioning of environments linked with various types of libraries. The goal of literature analysis was to determine the current condition of research on social capital in libraries. The main trends were identified and the need for further qualitative analyses, which are missing at the moment, was confirmed. Findings It was determined that, so far, LIS professionals have focussed mainly on the role of municipal libraries in developing social capital, the problem of building trust, especially in immigrant circles and the impact of libraries on promoting a civil society. Academic libraries, rural libraries, organisational capital in libraries and individual social capital of librarians were a much less frequent subject of research. The role of libraries in developing social capital in educational (primary and secondary education) and professional (non-university professionals) circles is practically non-existent in research, and it will require in-depth studies and analyses in the coming years. Originality/value This paper constitutes a synthetic review of the latest research concepts concerning social capital in libraries. It identifies the most important research trends and areas that so far have not been explored and suggests research methods to help LIS professionals design future research in this area more effectively.

Impact of perceived organizational support and green transformational leadership on sustainable organizational performance: a SEM approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Manita Kusi ◽  
Fuqiang Zhao ◽  
Dinesh Sukamani
Keyword(s):  
Transformational Leadership ◽  
Organizational Performance ◽  
Organizational Support ◽  
Perceived Organizational Support ◽  
Current Knowledge ◽  
Future Research ◽  
Content Type ◽  
The Relationship ◽  
Staff Level

PurposeThe study aims to scrutinize the concomitant associations between corporate social responsibility (CSR), perceived organizational support (POS), green transformational leadership (GTL) and organizational performance (OP). This paper aims to explore the role of intervening variable to measure the strength on the relationship between CSR and OP.Design/methodology/approachThis research administered a survey through self-administered questionnaire among the staff-level employees of construction companies of Nepal. Fully filled 305 responses from the participants were analyzed using a structural equation model. The study used self-structured questionnaire as research tool and face-to-face meetings as data collection technique.FindingsThe research indicates that POS showed competitive partial mediation relation between CSR and OP. Besides, a novel exploration of the moderation effect of GTL displays a supportive role in harmonizing the CSR with organizational support to achieve better OP. This study enriches empirical evidence to understand the linkage between CSR and POS in staff-level employees in the construction area. Moreover, the research shed a light on GTL 's moderating influence on the mediated model of CSR, POS and OP.Research limitations/implicationsAlthough the results of the study add to the current knowledge base, several limitations highlight avenues for future research. Future studies can explore the relationship in other study areas with added evidence on a similar result with different analysis patterns and study sample. The research model studied in the context of Nepal creating evidence as a representation for the developing countries.Originality/valueThe intervening role of POS and GTL gives new insight for the research-based organization based social behavior and performance

scholarly journals Harmful phytoplankton blooms and fish mortality in a eutrophicated reservoir of northeast Brazil

2008 ◽  
Vol 51 (4) ◽  
pp. 633-641 ◽  
Author(s):  
Naithirithi Tiruvenkatachary Chellappa ◽  
Sarah Laxhmi Chellappa ◽  
Sathyabama Chellappa
Keyword(s):  
Cyanobacterial Bloom ◽  
Hplc Method ◽  
Freshwater Ecosystems ◽  
Cyanobacterial Blooms ◽  
Fish Mortality ◽  
Cylindrospermopsis Raciborskii ◽  
Northeast Brazil ◽  
Cyanobacterial Toxin ◽  
Bloom Formation ◽  
Harmful Effects

The aim of this work was to study the eutrophication in the tropical freshwater ecosystems and the consequent cyanobacterial bloom formation and economical damage to fisheries and harmful effects to public health. Mass fish mortality due to toxin producing cyanobacterial blooms was registered during December 2003 in Marechal Dutra Reservoir, Acari/RN, Northeast Brazil. Phytoplankton and fish samplings were carried out on alternate days during the episode of fish mortality and monthly during January to June 2004. The cyanobacterial toxin was identified and quantified from the seston samples and liver of the dead fishes using the standard HPLC method. The results indicated that the toxic blooms of Cylindrospermopsis raciborskii and Microcystis aeruginosa were persistent for two weeks and represented 90% of the phytoplankton species assemblages. The lethally affected fishes were Oreochromis niloticus, Plagioscion squamosissimus, Cichla monoculus, Prochilodus brevis, Hoplias malabaricus and Leporinus friderici. The microcystin levels varied from 0.07 to 8.73µg L-1 the seston samples and from 0.01 to 2.59µg g-1in the liver samples of the fishes during the bloom period.

scholarly journals The role of microcystins in heavy cyanobacterial bloom formation

1998 ◽  
Vol 20 (4) ◽  
pp. 691-708 ◽  
Author(s):  
Bojan Sedmak ◽  
Gorazd Kosi
Keyword(s):  
Cyanobacterial Bloom ◽  
Bloom Formation

scholarly journals Emerging role of a novel small non-coding regulatory RNA: tRNA-derived small RNA

ExRNA ◽  
2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Fangfang Jin ◽  
Zhigang Guo
Keyword(s):  
Small Rna ◽  
Current Knowledge ◽  
Future Research ◽  
Regulatory Rna ◽  
Biological Functions ◽  
Research Directions ◽  
Non Coding Rna ◽  
Future Research Directions ◽  
Non Coding Rnas

Abstract The discovery of small non-coding RNAs, such as miRNA and piRNA, has dramatically changed our understanding of the role RNA plays in organisms. Recent studies show that a novel small non-coding RNA generated from cleavage of tRNA or pre-tRNA, called tRNA-derived small RNA (tsRNA), serves as a new regulator of gene expression. tsRNA has been determined participate in regulating some specific physiological and pathological processes. Although knowledge regarding the biological roles of miRNA and piRNA is expanding, whether tsRNAs play similar roles remains poorly understood. Here, we review the current knowledge regarding the mechanisms of action and biological functions of tsRNAs in intracellular, extracellular and intergenerational inheritance, and highlight the potential application of tsRNAs in human diseases, and present the current problems and future research directions.

scholarly journals A Brief Taxonomy of Hybrid Intelligence

Forecasting ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 633-643
Author(s):  
Niccolo Pescetelli
Keyword(s):  
Prediction Models ◽  
Collective Intelligence ◽  
Machine Intelligence ◽  
Future Research ◽  
Human Errors ◽  
Wide Range ◽  
Hybrid Intelligence ◽  
Forecasting System ◽  
Problem Solvers

As artificial intelligence becomes ubiquitous in our lives, so do the opportunities to combine machine and human intelligence to obtain more accurate and more resilient prediction models across a wide range of domains. Hybrid intelligence can be designed in many ways, depending on the role of the human and the algorithm in the hybrid system. This paper offers a brief taxonomy of hybrid intelligence, which describes possible relationships between human and machine intelligence for robust forecasting. In this taxonomy, biological intelligence represents one axis of variation, going from individual intelligence (one individual in isolation) to collective intelligence (several connected individuals). The second axis of variation represents increasingly sophisticated algorithms that can take into account more aspects of the forecasting system, from information to task to human problem-solvers. The novelty of the paper lies in the interpretation of recent studies in hybrid intelligence as precursors of a set of algorithms that are expected to be more prominent in the future. These algorithms promise to increase hybrid system’s resilience across a wide range of human errors and biases thanks to greater human-machine understanding. This work ends with a short overview for future research in this field.

scholarly journals Corporate Board Committees and Corporate Outcomes: An International Systematic Literature Review and Agenda for Future Research

2021 ◽  
pp. 2150001 ◽  
Author(s):  
Mohammed A. Alhossini ◽  
Collins G. Ntim ◽  
Alaa Mansour Zalata
Keyword(s):  
Literature Review ◽  
Empirical Evidence ◽  
Systematic Literature Review ◽  
Current Knowledge ◽  
Future Research ◽  
Applied Theory ◽  
Corporate Board ◽  
Theoretical Frameworks ◽  
Wide Range ◽  
The Individual

This paper comprehensively reviews the current body of international accounting literature regarding advisory/monitoring committees and corporate outcomes. Specifically, it synthesizes, appraises, and extends current knowledge on the (a) theoretical (i.e., economic, accounting/corporate governance, sociological and socio-psychological) perspectives and (b) empirical evidence of the observable and less visible attributes at both the individual and committee levels and their link with a wide range (financial/non-financial) of corporate outcomes. Using the systematic literature review method, 304 articles from 59 journals in the fields of accounting and finance that were published between January 1992 and December 2018 are reviewed. The main findings are as follows. First and theoretically, agency theory is the most dominant applied theory/studies with no application of theory at all (descriptive), while the application of integrated theoretical frameworks is lacking in the reviewed articles. Secondly, the existing empirical evidence focusses excessively on (a) monitoring instead of advisory committees and (b) observable rather than less visible committee attributes. Thirdly, scarcity of cross-country studies along with methodological limitations relating to measurement inconsistencies, insufficiency of variables, and dominance of quantitative studies, among others, are identified. Finally, promising future research avenues are outlined.

scholarly journals HYPOXIA AND REPRODUCTIVE HEALTH: The presence and role of hypoxia in the endometrium

Reproduction ◽  
2021 ◽  
Vol 161 (1) ◽  
pp. F1-F17
Author(s):  
Rocío Martínez-Aguilar ◽  
Lucy E Kershaw ◽  
Jane J Reavey ◽  
Hilary O D Critchley ◽  
Jacqueline A Maybin
Keyword(s):  
Current Knowledge ◽  
Abnormal Uterine Bleeding ◽  
Future Research ◽  
Hypoxic Episode ◽  
Optimal Function ◽  
Pros And Cons ◽  
The Impact ◽  
Review Current

The endometrium is a multicellular tissue that is exquisitely responsive to the ovarian hormones. The local mechanisms of endometrial regulation to ensure optimal function are less well characterised. Transient physiological hypoxia has been proposed as a critical regulator of endometrial function. Herein, we review the literature on hypoxia in the non-pregnant endometrium. We discuss the pros and cons of animal models, human laboratory studies and novel in vivo imaging for the study of endometrial hypoxia. These research tools provide mounting evidence of a transient hypoxic episode in the menstrual endometrium and suggest that endometrial hypoxia may be present at the time of implantation. This local hypoxia may modify the inflammatory environment, influence vascular remodelling and modulate endometrial proliferation to optimise endometrial function. Finally, we review current knowledge of the impact of this hypoxia on endometrial pathologies, with a focus on abnormal uterine bleeding. Throughout the manuscript areas for future research are highlighted with the aim of concentrating research efforts to maximise future benefits for women and society.

THE INTERACTIONS OF VERTEBRATES AND INVERTEBRATES IN PEATLANDS AND MARSHES

1987 ◽  
Vol 119 (S140) ◽  
pp. 15-30 ◽  
Author(s):  
Henry R. Murkin ◽  
Bruce D.J. Batt
Keyword(s):  
Current Knowledge ◽  
Life Cycles ◽  
Future Research ◽  
Aquatic Environments ◽  
Research Needs ◽  
Avian Community ◽  
Wide Range ◽  
Dead Plant ◽  
Living Organisms ◽  
And Function

AbstractThis paper reviews the interactions of vertebrates and invertebrates in peatlands and marshes to assess current knowledge and future research needs. Living organisms may interact through a number of direct trophic and nutrient pathways and a variety of non-trophic, habitat-dependent relationships. Freshwater marshes and peatlands are dynamic aquatic environments and organisms that occupy these areas must be adapted to a wide range of environmental conditions. The avian community illustrates the main interactions of invertebrates and vertebrates in peatlands and marshes. Waterfowl, along with fish and furbearers, are the most economically important vertebrates using these habitats. Each of these groups has important trophic and habitat links to the invertebrates within wetlands.The most common interaction between vertebrates and invertebrates is the use of invertebrates as food by vertebrates. Few studies, however, have dealt with trophic dynamics or secondary production within wetlands. Waterfowl, fish, and many other wetland vertebrates, during all or part of their life cycles, regularly feed on invertebrates. Some invertebrates are vectors of disease and parasites to vertebrates. Vertebrates can directly affect the structural substrate that invertebrates depend on as habitat through consumption of macrophytes or through the use of living and dead plant material in the construction of houses and nests. Conversely, herbivorous invertebrates may directly affect the survival and distribution of macrophytes in wetlands. Macrophyte distribution, in turn, is an important factor in determining vertebrate use of wetlands. The general lack of both taxonomic and ecological information on invertebrates in wetlands is the main hindrance to future elucidation of vertebrate–invertebrate interactions in these environments. Development of invertebrate sampling techniques suitable for wetland habitats also is necessary. More specific research needs must be met to develop a better understanding of the structure and function of these dynamic systems.

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