scholarly journals Aspectos ecológicos, taxonómicos y de distribución de cianobacterias bentónicas en ríos de la región central de México

2020 ◽  
Author(s):  
Mariana Guadalupe Cartajena Alcántara ◽  
Javier Carmona Jiménez ◽  
Elvira Perona Urizar
Keyword(s):  
Major Ions ◽  
Benthic Communities ◽  
Specific Conductivity ◽  
Sustainable Use ◽  
Distribution Patterns ◽  
Future Research ◽  
Mean Values ◽  
Cyanobacterial Species ◽  
Microenvironmental Factors ◽  
Calcareous Streams

Resumen:Antecedentes y Objetivos: Las cianobacterias son algas procariontes oxifotótrofas presentes en gran variedad de hábitats y son componentes importantes de las comunidades bentónicas en muchos ambientes continentales y marinos. En México su diversidad en ríos es poco conocida; por ello, este estudio contribuye al conocimiento ficoflorístico en cinco ríos de la región central de México. Se incluyen descripciones e ilustraciones, estimaciones de su diversidad, un análisis de las relaciones entre formas de crecimiento y factores microambientales, y se discute la validez de su caracterización morfológica y ecológica en la delimitación de las especies encontradas.Métodos: Se realizaron muestreos en secas y lluvias en dos ríos silíceos y tres ríos calcáreos del centro de México. Se registró la temperatura del agua, conductividad específica y pH, se analizaron iones mayores (Ca2+, Mg2+, K+, Na+, Si-SiO2, HCO3-, Cl-, SO43-) y nutrientes (NH4+,NO2-, NO32-, PO43-), se estimó la diversidad de las cianobacterias registradas con el índice de Shannon-Weaver y se describieron sus hábitats y microhábitats. La identificación taxonómica se realizó utilizando literatura especializada.Resultados clave: Se identificaron cuatro asociaciones y nueve especies pertenecientes a tres órdenes, siete familias y siete géneros. Se distinguieron dos grupos: el formado por Nostoc parmelioides-Coleodesmium wrangelii y Phormidium lividum-Leptolyngbya truncata en ríos silíceos de montaña y el compuesto por Schizothrix mexicana-Phormidium subfuscum, Homoeothrix juliana-Heteroleibleinia fontana y Nostoc verrucosum en ríos calcáreos cálidos. Se reconocieron dos patrones de distribución ecológica: 1) las especies del orden Nostocales presentes en condiciones estresantes de luz y velocidad de corriente y 2) los taxa de los órdenes Oscillatoriales y Synechococcales registrados en sitios con valores promedio de luz y flujo de agua.Conclusiones: La caracterización morfológica y ecológica de especies de cianobacterias contribuye a su conocimiento ficoflorístico y es la base para futuras investigaciones sobre taxonomía, sistemática y uso sustentable de recursos algales.Palabras clave: asociaciones, diversidad, ríos calcáreos, ríos silíceos. Abstract:Background and Aims: Cyanobacteria are oxyphototrophic prokariotic algae present in great variety of habitats and they are important components of the benthic communities in many continental and marine environments. In Mexico, their diversity in streams is less known; therefore, this study contributes to phycofloristic knowledge in five streams of the central region of Mexico. Descriptions and illustrations, estimations of their diversity, an analysis of the relationships between growth forms and microenvironmental factors are included, and the validity of their morphological and ecological characterization in the delimitation of the species found is discussed.Methods: Sampling was carried out in dry and rainy seasons in two siliceous streams and three calcareous streams of central Mexico. Water temperature, specific conductivity and pH were recorded, major ions (Ca2+, Mg2+, K+, Na+, Si-SiO2, HCO3-,Cl-, SO43-) and nutrients (NH4+,NO2-, NO32-, PO43-) were analyzed, the diversity was estimated of the cyanobacteria registered with the Shannon-Weaver index, and their habitats and microhabitats were described. Taxonomic identification was carried out with specialized literature.Key results: Four associations and nine species belonging to three orders, seven families and seven genera were identified. Two groups were distinguished: one formed by Nostoc parmelioides-Coleodesmium wrangelii, Phormidium lividum-Leptolyngbya truncata in siliceous and mountain streams, and one composed by Schizothrix mexicana-Phormidium subfuscum, Homoeothrix juliana-Heteroleibleinia fontana and Nostoc verrucosum in calcareous, warm streams. Two ecological distribution patterns were recognized: 1) the Nostocales species present in stressful conditions of light and current velocity and 2) the taxa of Oscillatoriales and Synechoccales registered in sites with mean values of light and water flow.Conclusions: Morphological and ecological characterization of cyanobacterial species contributes to their phycofloristic knowledge and the base for future research on taxonomy, systematics and sustainable use of algal resources.Key words: associations, calcareous streams, diversity, siliceous streams.

HEAVY METALS IN WATER, SEDIMENTS AND MARINE FISHES FROM BULGARIAN BLACK SEA

2017 ◽  
Author(s):  
Katya Peycheva ◽  
Katya Peycheva ◽  
Mona Stancheva ◽  
Mona Stancheva ◽  
Stanislava Georgieva ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Black Sea ◽  
Fish Species ◽  
Distribution Patterns ◽  
Marine Fishes ◽  
Marine Water ◽  
Mean Values ◽  
Sprattus Sprattus ◽  
Cu And Zn

In this study, the ecosystem marine water-sediment-biota was investigated and the pollution was assessed. The concentrations of eight elements were determined in marine water, sediments and four fish species collected from Black Sea (Varna), Bulgaria during 2013. Marine water recorded the highest concentrations of Zn (15-22 μg/L), As (1.1–1.2 μg/L) and Pb (0.7-0.8 μg/L) while Zn (31-52 μg/g), Pb (21-29 μg/g) and Cu (20-34 μg/g) and show the highest concentrations in sediments. Water and sediments showed similar spatial distribution patterns for the highest mean values of the different metals. In the analysed fish species, the highest concentration of the metals Cu and Zn were found in Trachurus Mediterrneus (0.42 mg/kg w.w) and in Sprattus Sprattus (12.7 mg/kg w.w), respectively while the heavy metals As and Hg were found with maximum values in Pseta Maxima (3.99 mg/kg w.w and 0.08 mg/kg w.w respectively). The results from this study were compared with our data for a previous period (2004-2006) and they show decrease in the levels of heavy metal.

Contribution a la rationalisation du reseau qualite de l’eau de la Baie James

1977 ◽  
Vol 12 (1) ◽  
pp. 51-76
Author(s):  
B. Bobée ◽  
D. Cluis ◽  
A. Tessier
Keyword(s):  
Correspondence Analysis ◽  
Major Ions ◽  
Base Station ◽  
Base Stations ◽  
James Bay ◽  
Mean Values ◽  
Multivariate Technique ◽  
Qualité De L’Eau ◽  
Concentration Changes ◽  
The Relationship

Abstract A water quality sampling programme for James Bay territory established in a previous study has been carried out for the Department of Natural Resources of the Province of Quebec. The network is composed of 5 base-stations, sampled every fortnight to determine the variability with time of the parameters and 16 satellite-stations, sampled five times yearly with a view to determine the spatial variability. The data (major ions and certain nutrients) gathered during the 1974–1975 field survey are subjected to an analysis by a multivariate technique (correspondence analysis) in addition to certain classical statistical methods. The latter have shown that the mean values obtained at satellite stations were representative of the annual mean. In addition, the results permit the determination for a given parameter, of the relationship between stations and, for a given station, the relationship between parameters. In both cases, the formulation of predictive equations was attempted. An overall evaluation of the data by correspondence analysis has permitted: - a more precise definition of the qualitative behaviour of the different sub-basins of the James Bay territory and characterization of their waters;- a proof of the existence of gradual concentration changes in both East-West and North-South directions. Within the original objectives of the network, the results of the study have led to the following recommendations: - to continue synchronised samplings;- to transform a base station with a low information content into a satellite station;- to create a new base station in the eastern part of the territory.

scholarly journals A Regional Review of Genetic Resource Access and Benefit Sharing – Key Issues and Research Gaps

2021 ◽  
pp. 1-24
Author(s):  
Clare Morrison ◽  
Fran Humphries ◽  
Charles Lawson
Keyword(s):  
Intellectual Property ◽  
Traditional Knowledge ◽  
Biological Diversity ◽  
National Level ◽  
Sustainable Use ◽  
Benefit Sharing ◽  
Comparative Approach ◽  
Future Research ◽  
Access And Benefit Sharing ◽  
Legal Mechanism

Countries are increasingly using access and benefit sharing (ABS) as a legal mechanism to support the conservation and sustainable use of the world’s biological diversity. ABS regulates collection and/or use of genetic resources/traditional knowledge and sharing benefits from their use with the provider. The purpose of this review is to assess the trends, biases and gaps of ABS literature using a regional comparative approach about the key topics of concern between each region. It analyses four key topic groupings: (1) implementation of international, regional and national ABS policy and law; (2) intellectual property and ABS; (3) traditional knowledge; and (4) research, development and commercialisation. Findings included gaps in: (1) analysing effectiveness of national level implementation; (2) addressing apparent conflicts between support for intellectual property promoting exclusivity for traditional knowledge and challenges to intellectual property exclusivity for patents; (3) examining traditional knowledge of local communities (in contrast to Indigenous Peoples); and (4) lack of practical examples that quantify benefit sharing from research and commercialisation outcomes. We conclude that future research addressing the identified gaps and biases can promote more informed understanding among stakeholders about the ABS concept and whether it is capable of delivering concrete biological conservation, sustainable use and equity outcomes.

scholarly journals Plant Biostimulants from Cyanobacteria: An Emerging Strategy to Improve Yields and Sustainability in Agriculture

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 643
Author(s):  
Gaia Santini ◽  
Natascia Biondi ◽  
Liliana Rodolfi ◽  
Mario R. Tredici
Keyword(s):  
Nutrient Use Efficiency ◽  
Biologically Active ◽  
Future Research ◽  
Plant Tolerance ◽  
Metabolic Plasticity ◽  
Nutrient Use ◽  
Cyanobacterial Species ◽  
Use Efficiency ◽  
Promising Source ◽  
Plant Treatment

Cyanobacteria can be considered a promising source for the development of new biostimulants as they are known to produce a variety of biologically active molecules that can positively affect plant growth, nutrient use efficiency, qualitative traits of the final product, and increase plant tolerance to abiotic stresses. Moreover, the cultivation of cyanobacteria in controlled and confined systems, along with their metabolic plasticity, provides the possibility to improve and standardize composition and effects on plants of derived biostimulant extracts or hydrolysates, which is one of the most critical aspects in the production of commercial biostimulants. Faced with these opportunities, research on biostimulant properties of cyanobacteria has undergone a significant growth in recent years. However, research in this field is still scarce, especially as regards the number of investigated cyanobacterial species. Future research should focus on reducing the costs of cyanobacterial biomass production and plant treatment and on identifying the molecules that mediate the biostimulant effects in order to optimize their content and stability in the final product. Furthermore, the extension of agronomic trials to a wider number of plant species, different application doses, and environmental conditions would allow the development of tailored microbial biostimulants, thus facilitating the diffusion of these products among farmers.

scholarly journals Diversity, distribution and spatial structure of the cold-water coral fauna of the Azores (NE Atlantic)

2013 ◽  
Vol 10 (6) ◽  
pp. 4009-4036 ◽  
Author(s):  
A. Braga-Henriques ◽  
F. M. Porteiro ◽  
P. A. Ribeiro ◽  
V. de Matos ◽  
Í. Sampaio ◽  
...  
Keyword(s):  
Spatial Structure ◽  
Cold Water ◽  
Current Knowledge ◽  
Fish Habitat ◽  
Sustainable Use ◽  
Distribution Patterns ◽  
Taxonomic Diversity ◽  
Conservation Policies ◽  
Coral Fauna ◽  
By Catch

Abstract. Cold-water corals are widely considered as important structural components of benthic habitats, potentially enhancing local abundance in a variety of fish and invertebrate species. Yet, current knowledge of the taxonomic diversity and distribution patterns of these vulnerable, slow-growing organisms is scarce and fragmented, limiting the effectiveness of spatial management and conservation measures. We have conducted an exhaustive compilation of records of alcyonaceans, antipatharians, scleractinians and stylasterids available through present day to assess the diversity, distribution and spatial structure of coral assemblages in the Azores exclusive economic zone (EEZ). The resulting database comprises 2501 entries concerning historical oceanographic expeditions and other published sources, as well as unpublished data from bottom longline by-catch. Our taxonomic inventory appears to be fairly complete for the explored habitats, accounting for 164 species (79 alcyonaceans, 58 scleractinians, 18 antipatharians and 9 stylasterids), nine of which were documented for the first time. The Azores EEZ harbours a mixed coral fauna with several zoogeographic origins, showing the closest affinity with the Lusitanian–Mediterranean region. Very few apparent endemics were found (14%), and only in part supported by consistent sampling. Coral diversity is particularly high between 300 and 900 m depths, in areas recognized as traditional fishing grounds or exploitable fish habitat within the 100-mile limit of the EEZ. The composition of coral assemblages shows significant geographical structure among longitudinal sections of the study area at comparable depths (100–1500 m). There is no evidence of a possible role of the Mid-Atlantic Ridge or latitudinal effects underlying this pattern, which suggests that it may instead reflect assemblage variability among features. Stronger changes in species composition were found along the bathymetric gradient. Notwithstanding the mix of partially overlapping steno- and eurybathic species that characterize the vertical distribution of corals, there is a distinct transition from shallow (100–600 m) to intermediate (600–1000 m) depths. The analysis presented here constitutes a valuable contribution for efficient conservation policies of coral-associated vulnerable marine ecosystems and their sustainable use as fishing areas.

scholarly journals Quality of life in a sample of Brazilian adults using the generic SF-12 questionnaire

2018 ◽  
Vol 64 (3) ◽  
pp. 234-242 ◽  
Author(s):  
Alessandro Gonçalves Campolina ◽  
Rossana Veronica Mendoza Lopez ◽  
Elene Paltrinieri Nardi ◽  
Marcos Bosi Ferraz
Keyword(s):  
Quality Of Life ◽  
Skin Color ◽  
Short Form ◽  
Mean Value ◽  
Life Assessment ◽  
Future Research ◽  
Mean Values ◽  
Socio Demographic Factors ◽  
Assess Quality

Summary Objective: This study describes the summary scores of the Short Form-12 (SF-12) questionnaire, according to socio-demographic factors obtained in a probabilistic and representative sample of the Brazilian urban population. Method: Five thousand (5,000) individuals, over the age of 15, were assessed in 16 capital cities, in the five regions of the country. The selection of households was random. Face-to-face approach was applied in the household interviews. The SF-12 questionnaire was used to assess quality of life. Demographic and socioeconomic characteristics were also evaluated: gender, age, marital status, skin color, region of the country and use of the public health service. Results: The mean value (SD) of the SF-12 for the entire population was 49.3 (8.7) for the physical component (PCS-12) and 52.7 (9.7) for the mental component (MCS-12). Statistical differences were found for gender (PCS-12 and MCS-12), age (PCS-12) and working status (PCS-12 and MCS-12). Women, elderly, widowed and unemployed individuals, those with lower income and with complaints in the last seven days showed lower mean values (PCS-12 and MCS-12). Conclusion: From this point forward, we can provide the basis for comparisons with future research that use the SF-12 for quality of life assessment in Brazil. The Brazilian population has a lower degree of quality of life related do the physical component, and the SF-12 is a useful and discriminative instrument for assessing quality of life in different socio-demographic groups.

scholarly journals Autoeficácia em Professores do Ensino Superior

2019 ◽  
Vol 20 (3) ◽  
pp. 319
Author(s):  
José Ricardo Claudino Ribeiro ◽  
Camila Cristina Fonseca Bicalho ◽  
Marcos Teixeira de Abreu Soares Onofre ◽  
Franco Noce
Keyword(s):  
Biological Sciences ◽  
Higher Education ◽  
Self Efficacy ◽  
Minas Gerais ◽  
The Self ◽  
University Education ◽  
Future Research ◽  
Mean Values ◽  
Private Network ◽  
Social Persuasion

O objetivo deste estudo foi avaliar a percepção de autoeficácia em professores do Ensino Superior e avaliar as propriedades psicométricas da Escala de Autoeficácia para Professores do Ensino Superior para o contexto brasileiro. Participaram deste estudo 188 professores do Ensino Superior de instituições da rede privada de Minas Gerais. Os professores lecionavam nas áreas da Educação Física, Nutrição, Ciências Biológicas, Geografia, Fisioterapia, Medicina, Análise de Sistemas, Enfermagem, Turismo e Pedagogia. A amostra foi composta por 61,5% de professores do sexo masculino. Em relação à formação, foi predominante a participação de professores com especialização Lato Sensu (52,9%). Todos os professores responderam a Escala de Autoeficácia para Docentes do Ensino Superior-EADES. Os resultados mostraram que a escala está adequada para a avaliação da autoeficácia em professores (α=0,92). Em relação ao quanto os professores se sentem capazes de realizar suas tarefas docentes, foram verificados valores médios entre 5,01 e 5,65, o que representa um alto valor de percepção de autoeficácia pelos professores. Conclui-se que os principais fatores responsáveis pela autoeficácia dos professores são a Satisfação, a Persuasão Social e as Experiências Pregressas. Estes aspectos fornecem uma importante sugestão sobre as possibilidades de exploração destes fatores no que diz respeito às futuras aquisições, programas de formação e pesquisas futuras. Palavras-chave: Validação. Eficácia Docente. Educação Superior. AbstractThe aim of this study was to evaluate the perception of self-efficacy in higher education teachers and to evaluate the psychometric properties of the Self-efficacy Scale for higher education teachers in the Brazilian context. A total of 188 higher education teachers from institutions of the private network of Minas Gerais participated in this study. Teachers taught in the areas of Physical Education, Nutrition, Biological Sciences, Geography, Physiotherapy, Medicine, Systems Analysis, Nursing, Tourism and Pedagogy. The sample consisted of 61.5% male teachers. All teachers answered the Self-Efficacy Scale for Teachers of Higher Education-EADES. Lato Sensu teachers (52.9%), followed by master teachers (34.8%), doctors (9.6%) and graduates (2.7%) predominated. The results showed that the scale is adequate for the evaluation of self-efficacy in teachers (α=0.92). In relation to how much teachers feel capable of performing their teaching tasks, mean values between 5.01 and 5.65 were verified, which represents a high value of self-efficacy perception among teachers. It is concluded that the main factors responsible for teachers' self-efficacy are satisfaction, social persuasion and previous experiences. These aspects provide an important suggestion about the possibilities of exploring these factors with regard to future acquisitions, training programs and future research. Keywords: Validation. Professor Efficacy. University Education. 

scholarly journals AN EX-ANTE ASSESSMENT OF CITY DISTRIBUTION ALTERNATIVES BASED ON MULTI ACTOR MULTI CRITERIA FRAMEWORK

2020 ◽  
Vol 8 (5) ◽  
pp. 4241-4272
Author(s):  
Türkan Müge ÖZBEKLER ◽  
Arzu KARAMAN AKGÜL
Keyword(s):  
Urban Areas ◽  
Noise Pollution ◽  
Distribution Patterns ◽  
Distribution Networks ◽  
Future Research ◽  
Negative Externalities ◽  
Novel Approach ◽  
Load Factors ◽  
Ex Ante ◽  
Urban Consolidation

Recently, urban areas face challenges that result from negative externalities of traditional distribution networks. Especially, city actors increasingly suffer from issues as inefficient load factors in operations, traffic volume on roads, and noise pollution. To overcome these problems, modern city distribution patterns integrated with the consolidation strategy have the potential to provide satisfying solutions. Align with city actors’ expectations, alternatives of consolidation-distribution schemes can offer improvements in both economic, social, and environmental issues. In particular, this study aims at an ex-ante evaluation of city distribution alternatives on the typology of consolidation-distribution schemes ensuring win-win solutions to each city actor. This paper adopts Multi Actor Multi-Criteria Analysis (MAMCA) as a novel approach to evaluating different city actors’ objectives and a set of city distribution alternatives comprehensively. The paper results highlight that micro consolidation centre facilities can be more suitable in response to city actors’ expectations among distribution alternatives to urban consolidation centre and mobile depot. Finally, future research in this topic can focus on evaluating distribution alternatives on a sector basis and marketing types such as B2B and B2C.  

scholarly journals ‘Pre-Neolithic’ in Southeast Europe: a Bulgarian perspective

2014 ◽  
Vol 41 ◽  
pp. 95-109 ◽  
Author(s):  
Maria Gurova ◽  
Clive Bonsall
Keyword(s):  
Black Sea ◽  
Resource Availability ◽  
Environmental Conditions ◽  
Distribution Patterns ◽  
Balkan Peninsula ◽  
The Black Sea ◽  
Future Research ◽  
Upper Palaeolithic ◽  
Southeast Europe ◽  
Site Distribution

 This paper discusses why large areas of the central and northern Balkans lack evidence of Mesolithic settlement and what implications this holds for future research into the Neolithization of the region. A marked shift in site distribution patterns between Upper Palaeolithic and Mesolithic is interpreted as a response to changing environmental conditions and resource availability. It is suggested that some important questions of the pattern, processes and timing of the transition to farming across the Balkan Peninsula may only be answered through new archaeological surveys of the Lower Danube valley and exploration of submerged landscapes along the Black Sea, Aegean and Adriatic coasts.

Application of Fuzzy Numbers to Assessment Processes

2018 ◽  
pp. 3215-3225
Author(s):  
Michael Voskoglou
Keyword(s):  
Assessment Tool ◽  
Special Kind ◽  
Assessment Method ◽  
Future Research ◽  
Grade Point ◽  
Mean Values ◽  
The Subject ◽  
The Mean ◽  
Fuzzy Assessment ◽  
Classical Arithmetic

A Fuzzy Number (FN) is a special kind of FS on the set R of real numbers. The four classical arithmetic operations can be defined on FNs, which play an important role in fuzzy mathematics analogous to the role played by the ordinary numbers in crisp mathematics (Kaufmann & Gupta, 1991). The simplest form of FNs is the Triangular FNs (TFNs), while the Trapezoidal FNs (TpFNs) are straightforward generalizations of the TFNs. In the present work a combination of the COG defuzzification technique and of the TFNs (or TpFNs) is used as an assessment tool. Examples of assessing student problem-solving abilities and basket-ball player skills are also presented illustrating in practice the results obtained. This new fuzzy assessment method is validated by comparing its outcomes in the above examples with the corresponding outcomes of two commonly used assessment methods of the traditional logic, the calculation of the mean values and of the Grade Point Average (GPA) index. Finally, the perspectives of future research on the subject are discussed.

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