scholarly journals Morphological Variations of Wild Populations of Brycon dentex (Characidae, Teleostei) in the Guayas Hydrographic Basin (Ecuador). The Impact of Fishing Policies and Environmental Conditions

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1901
Author(s):  
Ana Gonzalez-Martinez ◽  
Carmen De-Pablos-Heredero ◽  
Martin González ◽  
Jorge Rodriguez ◽  
Cecilio Barba ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Environmental Conditions ◽  
Anthropogenic Activity ◽  
Freshwater Species ◽  
Fishing Pressure ◽  
Wild Populations ◽  
Morphometric Variation ◽  
Morphological Variations ◽  
Body Development ◽  
The Impact

The Guayas, located in Ecuador, is the largest basin in the Pacific Ocean and has an inventory of 123 native freshwater species. Most of these are endemic species that are threatened or at-risk due to anthropogenic activity and the modification, fragmentation, and destruction of habitats. The aim of this study was to determine the morphometric variation in three wild populations of Brycon dentex in the Guayas basin rivers and their connections to fishing management and environmental conditions. A total of 200 mature fish were captured, and 26 morphometric parameters were measured. The fishing policies (Hypothesis 1) and environmental conditions (Hypothesis 2) were considered fixed factors and were validated by t-tests. The morphological variation among the three populations (Hypothesis 3) was validated through a discriminant analysis. Fishing policies and resource management were found to generate morphological differences associated with body development. In addition, the environmental conditions were found to influence the size and structure of Brycon dentex populations. The analyzed populations were discriminated by the generated morphometric models, which differentiated Cluster 1 (Quevedo and Mocache rivers) with high fishing pressure from Cluster 2 (Pintado river) with medium–low fishing pressure. Morphometric differentiation by discriminant analysis is a direct and economic methodology that can be applied as an indicator of diversity maintenance.

scholarly journals Morphological variation in Opuntia jaliscana (Cactaceae)

2017 ◽  
Vol 74 (1) ◽  
pp. 058
Author(s):  
Edgar Noel López-Borja ◽  
Rosa De Lourdes Romo-Campos ◽  
Hilda Julieta Arreola-Nava ◽  
Alejandro Muñoz Urias ◽  
Sofía Loza-Cornejo
Keyword(s):  
Discriminant Analysis ◽  
Morphological Variability ◽  
Fruit Size ◽  
Aridity Index ◽  
Wild Populations ◽  
Discriminant Functions ◽  
Morphological Variations ◽  
Quantitative Characters ◽  
Reproductive Characters ◽  
One Way Anova

The aim of this study was to describe morphological variations of Opuntia jaliscana in 5 wild populations in the state of Jalisco (Mexico). Populations were selected along an environmental aridity gradient, and 61 vegetative and reproductive characters from 25 individuals were measured per population. Quantitative characters were analyzed independently by a one-way ANOVA test using the site as variation factor. Subsequently, a discriminant analysis was performed. The discriminant analysis results showed that the 46% of the total variation was explained by the first four discriminant functions. The analysis of overall membership between populations indicated that individuals were correctly classified in 87% of cases. Pearson linear correlation between the most significant variables and the aridity index, showed a positive relationship to cladode thickness and diameter of the trunk. The population from Tierra Blanca shows an outlier behavior because of variation in cladode thickness and fruit size, which might be related to plasticity of individuals to have a greater availability of water, while in Los Vallejo the separation might be due to selection by management and use. The remaining populations exhibited some morphological variability without separation.

From Silent Spring to The Frog of War

2017 ◽  
Author(s):  
David K. Skelly
Keyword(s):  
Natural History ◽  
Laboratory Experiments ◽  
Wild Populations ◽  
Rachel Carson ◽  
Chemical Agents ◽  
Silent Spring ◽  
The World ◽  
History Information ◽  
Wildlife Populations ◽  
The Impact

This chapter presents two examples to demonstrate that natural history is the necessary basis of any reliable understanding of the world. More than a half century ago, Rachel Carson revolutionized the public’s view of pesticides. The foundation of her success was the careful use of natural history data, collated from across North America. The examples she assembled left little doubt that DDT and other pesticides were causing a widespread decline in birds. More recently, the case for the impact of atrazine on wildlife was based on laboratory experiments, without the advantage of natural history observations. For atrazine, natural history observations now suggest that other chemical agents are more likely to be responsible for feminization of wildlife populations. Developing expectations for scientists to collect natural history information can help to avoid over-extrapolating lab results to wild populations, a tendency often seen when those lab results conform to preconceptions about chemicals in the environment.

scholarly journals Ground-Based MAX-DOAS Observations of Tropospheric NO2 and HCHO During COVID-19 Lockdown and Spring Festival Over Shanghai, China

2021 ◽  
Vol 13 (3) ◽  
pp. 488
Author(s):  
Aimon Tanvir ◽  
Zeeshan Javed ◽  
Zhu Jian ◽  
Sanbao Zhang ◽  
Muhammad Bilal ◽  
...  
Keyword(s):  
Air Quality ◽  
Anthropogenic Activities ◽  
Anthropogenic Activity ◽  
Hysplit Model ◽  
Vertical Column ◽  
Weekly Cycle ◽  
Spring Festival ◽  
Level 1 ◽  
Reduced Mobility ◽  
The Impact

Reduced mobility and less anthropogenic activity under special case circumstances over various parts of the world have pronounced effects on air quality. The objective of this study is to investigate the impact of reduced anthropogenic activity on air quality in the mega city of Shanghai, China. Observations from the highly sophisticated multi-axis differential optical absorption spectroscope (MAX-DOAS) instrument were used for nitrogen dioxide (NO2) and formaldehyde (HCHO) column densities. In situ measurements for NO2, ozone (O3), particulate matter (PM2.5) and the air quality index (AQI) were also used. The concentration of trace gases in the atmosphere reduces significantly during annual Spring Festival holidays, whereby mobility is reduced and anthropogenic activities come to a halt. The COVID-19 lockdown during 2020 resulted in a considerable drop in vertical column densities (VCDs) of HCHO and NO2 during lockdown Level-1, which refers to strict lockdown, i.e., strict measures taken to reduce mobility (43% for NO2; 24% for HCHO), and lockdown Level-2, which refers to relaxed lockdown, i.e., when the mobility restrictions were relaxed somehow (20% for NO2; 22% for HCHO), compared with pre-lockdown days, as measured by the MAX-DOAS instrument. However, for 2019, a reduction in VCDs was found only during Level-1 (24% for NO2; 6.62% for HCHO), when the Spring Festival happened. The weekly cycle for NO2 and HCHO depicts no significant effect of weekends on the lockdown. After the start of the Spring Festival, the VCDs of NO2 and HCHO showed a decline for 2019 as well as 2020. Backward trajectories calculated using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model indicated more air masses coming from the sea after the Spring Festival for 2019 and 2020, implying that a low pollutant load was carried by them. No impact of anthropogenic activity was found on O3 concentration. The results indicate that the ratio of HCHO to NO2 (RFN) fell in the volatile organic compound (VOC)-limited regime.

scholarly journals Usefulness of Discriminant Analysis in the Morphometric Differentiation of Six Native Freshwater Species from Ecuador

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 111
Author(s):  
Ana Gonzalez-Martinez ◽  
Carmen De-Pablos-Heredero ◽  
Martin González ◽  
Jorge Rodriguez ◽  
Cecilio Barba ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Rural Communities ◽  
Development Program ◽  
Freshwater Species ◽  
Hydrographic Basin ◽  
Wilks Lambda ◽  
Morphological Variables ◽  
Morphometric Differentiation ◽  
Discriminant Power

The aim of this research was to find out the morphometric differentiation of six native freshwater species in the Guayas Hydrographic Basin (Ecuador) by means of discriminant analysis. A total of 1355 mature fishes (Cichlasoma festae, Andinoacara rivulatus, Dormitator latifrons, Bryncon dentex, Hoplias microlepis and Leporinus ecuadorensis) were captured and 27 morphometric measurements and 20 landmarks were used. Two-way analysis of variance with species and sex as fixed factors and discriminant analysis were applied. The selection of the most discriminant variables was made applying the F of Snedecor, Wilks’-Lambda and the 1-Tolerance. While sex within species had no significant effect on the morphology, differences among species were significant. Twenty-seven morphological variables showed highly significant differences among six native freshwater species. Nine biometric variables with high discriminant power were selected. The six species analyzed were discriminated by the morphometric models generated, thus showing that discriminant analysis was useful for differentiating species. The morphometric differentiation by discriminant analysis is a direct, simple and economic methodology to be applied in situ in rural communities. It favors the implementation of a livestock development program and it could be used with other native freshwater species in the Guayas Hydrographic Basin.

scholarly journals On the diverse and opposing effects of nutrition on pathogen virulence

2019 ◽  
Vol 286 (1906) ◽  
pp. 20191220 ◽  
Author(s):  
Victoria L. Pike ◽  
Katrina A. Lythgoe ◽  
Kayla C. King
Keyword(s):  
Infectious Disease ◽  
Immune System ◽  
Meta Analysis ◽  
Anthropogenic Factors ◽  
Anthropogenic Activity ◽  
Pathogen Virulence ◽  
Disease Outcomes ◽  
Host Nutrition ◽  
Opposing Effects ◽  
The Impact

Climate change and anthropogenic activity are currently driving large changes in nutritional availability across ecosystems, with consequences for infectious disease. An increase in host nutrition could lead to more resources for hosts to expend on the immune system or for pathogens to exploit. In this paper, we report a meta-analysis of studies on host–pathogen systems across the tree of life, to examine the impact of host nutritional quality and quantity on pathogen virulence. We did not find broad support across studies for a one-way effect of nutrient availability on pathogen virulence. We thus discuss a hypothesis that there is a balance between the effect of host nutrition on the immune system and on pathogen resources, with the pivot point of the balance differing for vertebrate and invertebrate hosts. Our results suggest that variation in nutrition, caused by natural or anthropogenic factors, can have diverse effects on infectious disease outcomes across species.

ASSESSING ENVIRONMENTAL IMPACTS DURING NATURAL DISASTER: THE DEVELOPMENT OF A RAPID ENVIRONMENTAL ASSESSMENT METHODOLOGY

2002 ◽  
Vol 04 (04) ◽  
pp. 475-492 ◽  
Author(s):  
CHARLES KELLY
Keyword(s):  
Environmental Impact ◽  
Impact Assessment ◽  
Environmental Impact Assessment ◽  
Environmental Conditions ◽  
Environmental Damage ◽  
Assessment Procedure ◽  
Disaster Victims ◽  
Wide Range ◽  
Negative Impacts ◽  
The Impact

The linkages between disaster and environmental damage are recognized as important to predicting, preventing and mitigating the impact of disasters. Environmental Impact Assessment (EIA) procedures are well developed for non-ndisaster situations. However, they are conceptually and operationally inappropriate for use in disaster conditions, particularly in the first 120 days after the disaster has begun. The paper provides a conceptual overview of the requirements for an environmental impact assessment procedure appropriate for disaster conditions. These requirements are captured in guidelines for a Rapid Environmental Impact Assessment (REA) for use in disasters. The REA guides the collection and assessment of a wide range of factors which can indicate: (1) the negative impacts of a disaster on the environment, (2) the impacts of environmental conditions on the magnitude of a disaster and, (3) the positive or negative impacts of relief efforts on environmental conditions. The REA also provides a foundation for recovery program EIAs, thus improving the overall post disaster recovery process. The REA is designed primarily for relief cadres, but is also expected to be usable as an assessment tool with disaster victims. The paper discusses the field testing of the REA under actual disaster conditions.

scholarly journals Ozone damage, detoxification and the role of isoprenoids – new impetus for integrated models

2016 ◽  
Vol 43 (4) ◽  
pp. 324 ◽  
Author(s):  
Supriya Tiwari ◽  
Rüdiger Grote ◽  
Galina Churkina ◽  
Tim Butler
Keyword(s):  
Stomatal Conductance ◽  
Environmental Conditions ◽  
Economic Losses ◽  
Plant Responses ◽  
Damage Scenarios ◽  
Biochemical Processes ◽  
Wide Range ◽  
Defence Responses ◽  
High Concentrations ◽  
The Impact

High concentrations of ozone (O3) can have significant impacts on the health and productivity of agricultural and forest ecosystems, leading to significant economic losses. In order to estimate this impact under a wide range of environmental conditions, the mechanisms of O3 impacts on physiological and biochemical processes have been intensively investigated. This includes the impact on stomatal conductance, the formation of reactive oxygen species and their effects on enzymes and membranes, as well as several induced and constitutive defence responses. This review summarises these processes, discusses their importance for O3 damage scenarios and assesses to which degree this knowledge is currently used in ecosystem models which are applied for impact analyses. We found that even in highly sophisticated models, feedbacks affecting regulation, detoxification capacity and vulnerability are generally not considered. This implies that O3 inflicted alterations in carbon and water balances cannot be sufficiently well described to cover immediate plant responses under changing environmental conditions. Therefore, we suggest conceptual models that link the depicted feedbacks to available process-based descriptions of stomatal conductance, photosynthesis and isoprenoid formation, particularly the linkage to isoprenoid models opens up new options for describing biosphere-atmosphere interactions.

Hydrodynamic Сonditions of the Bakalskaya Spit Degradation (Western Crimea) over the Past 30 Years

2021 ◽  
Vol 37 (3) ◽  
Author(s):  
B. V. Divinsky ◽  
R. D. Kosyan ◽  
◽  
Keyword(s):  
Discriminant Analysis ◽  
Coastal Zone ◽  
Satellite Images ◽  
Wind Waves ◽  
Total Duration ◽  
Wave Model ◽  
Statistical Characteristics ◽  
Wave Impact ◽  
Annual Variability ◽  
The Impact

Purpose. The paper is aimed at studying the morphodynamic features of the Bakalskaya Spit evolution being influenced by the sea wind waves and swell, namely assessment of inter-annual variations in the alluvial (erosion) areas of the Bakalskaya Spit coastline, analysis of inter-annual variability of the wind wave parameters, determination of the surface wave characteristics (or a combination of a few ones) responsible for the processes of the bottom material erosion or accumulation in the coastal zone. Methods and Results. Based on the analysis of satellite images for 1984–2016, the areas of the bottom material accumulation or erosion of the Bakalskaya Spit coastline were determined. Application of the spectral wave model permitted to obtain time series of the main parameters of wind waves and swell (significant wave heights and propagation directions) in the Bakalskaya Spit coastal zone with the 1 hr time resolution for the period from 1984 to 2016. The characteristics of surface waves responsible for the coastline deformation were revealed using the discriminant analysis. Conclusions. Analysis of satellite images of the spit made it possible to distinguish three periods in the history of the Bakalskaya Spit evolution: 1985–1997, 1998–2007 and 2007–2016. The first period was characterized by relative stability. The strongest erosion took place in 1998; after that the alluvial and erosion cases alternated for 10 years weakly tending to general erosion that constituted the second period. The third one that began in 2007 can be defined as the period of spit degradation accompanied by the irreversible loss of beach material. The basic parameters conditioning hydrodynamics of the Bakalskaya Spit water area are: total duration of storms; average and maximum values of significant heights of wind waves and swell. Statistical characteristics of the wind waves’ parameters are of a fairly strong inter-annual variability. According to the average and maximum indices, the wind waves directed close to the normal to the coastline (WSW and WNW) are the most developed. The applied discriminant analysis permitted to draw a statistically reliable conclusion that the direction of the final (average annual) wave impact on the coastal zone, conditioning the processes of sand accumulation or erosion was set by the waves directed to NNW, at that the swell contribution was dominant. The impact degree is conditioned by strong storms with the directions close to the normal to the coastline, namely, the WSW ones

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