Assessing the Relative Role of Environmental Factors That Limit the Distribution of the Yucatan Rattlesnake (Crotalus tzabcan)

2020 ◽  
Vol 54 (2) ◽  
pp. 216
Author(s):  
Carlos Yañez-Arenas ◽  
Sandra Castaño-Quintero ◽  
Rodolfo Rioja-Nieto ◽  
Karla Rodríguez-Medina ◽  
Xavier Chiappa-Carrara
Keyword(s):  
Environmental Factors ◽  
Relative Role

The role of propagule pressure and environmental factors on the establishment of a large invasive cyprinid: black carp in the Laurentian Great Lakes basin

2021 ◽  
pp. 1-15
Author(s):  
Eric R.B. Smyth ◽  
D. Andrew R. Drake
Keyword(s):  
Environmental Factors ◽  
Great Lakes ◽  
Environmental Conditions ◽  
Propagule Pressure ◽  
Adult Survival ◽  
Relative Role ◽  
Joint Models ◽  
Black Carp ◽  
Invasive Fishes

Understanding the factors underlying species establishment is critical for the management of invasive fishes, yet the roles of propagule pressure and environmental factors are infrequently quantified in joint models. We estimated the establishment likelihood of the invasive black carp (Mylopharyngodon piceus) by examining the relative influence of propagule pressure (introduction size and age structure) and environmental factors (temperature-driven young-of-year [YOY] overwinter survival, adult survival, age at maturity, and longevity). Simulations demonstrated that both propagule pressure and environmental factors can act as non-linear bottlenecks to establishment. When the model was applied to 12 Great Lakes tributaries and nearshore areas, black carp establishment was probable with sufficient propagules and under most environmental conditions (median p = 0.21–0.73, 0.70–1.00, and 0.46–0.97 for 100 pairs of age 4, age 9, and age 16 fish, respectively), except for YOY (p < 0.01). Our analysis is one of the few studies to examine the relative role of propagule pressure and environmental conditions on establishment, indicating that both factors can lead to establishment failure independently or concurrently within an ecosystem.

scholarly journals PROCESS-RESPONSE MODELS FOR DEPOSITIONAL SHORELINES: THE GERMAN AND THE GEORGIA BIGHTS

1978 ◽  
Vol 1 (16) ◽  
pp. 70 ◽  
Author(s):  
Dag Nummedal ◽  
Ian A. Fischer
Keyword(s):  
Simple Model ◽  
Environmental Factors ◽  
High Tide ◽  
Relative Role ◽  
Tidal Inlets ◽  
Dispersal Patterns ◽  
Response Models ◽  
High Wave ◽  
Sediment Dispersal

Sediment dispersal patterns in tidal inlets within the German and the Georgia Bights are found to be controlled by three major environmental factors: (1) the tide range, (2) the nearshore wave energy, and (3) the geometry of the backbarrier bay. Both embayments chosen for study are characterized by high wave energies and low tide ranges on their flanks, and low wave energies and high tide ranges in their centers. The spatial variability in inlet morphology, therefore, contains information on the relative role of tides and waves in inlet sediment dispersal. The paper concludes by proposing a simple model for inlet morphologies for successively greater relative role of tidal currents in the sediment dispersal.

scholarly journals Sensitivity and resistance of communities: Evaluation on the example of the influence of edaphic, vegetation and spatial factors on soil macrofauna

2017 ◽  
Vol 25 (4) ◽  
Author(s):  
O. V. Zhukov ◽  
O. M. Kunah ◽  
Y. Y. Dubinina
Keyword(s):  
Environmental Factors ◽  
Species Interactions ◽  
Community Response ◽  
Ecological System ◽  
Environmental Stability ◽  
Relative Role ◽  
Soil Macrofauna ◽  
Floodplain Soil ◽  
Main Components

Environmental stability is a multifaceted concept and includes properties such as asymptotic stability, robustness, persistence, variability, elasticity and resistance. Resistance reflects the ability of a community or population to remain in a substantially unaltered state under external influence. The reverse of resistance is sensitivity. This article suggests a way to assess the sensitivity of animal communities to factors of various character and explain sensitivity and resistance of the macrofauna community near the floodplain of the river Dnieper within the "Dnipro-Orelsky" Nature Reserve to the effects of edaphic and plant factors, as well as spatial variables. It is shown that the regulatory impact of environmental factors is refracted through the properties of ecological systems themselves, namely resistance and sensitivity. If an ecological system does not react to changing environmental factors, such a system is indifferent with respect to these factors. In the case of regulatory influence of factors, there may be resistance, sensitivity and the proportionality of the response of the ecological system. The ratio of the specific role of a factor in the variability of a community to the contribution of the main components of the total variability of the attributive space makes it possible to assess the resistance, sensitivity and proportionality of response the ecological system to the action of that factor. If the ratio is >1, then this indicates sensitivity: level of variability of a community is higher than the relative role of environmental factors in the changing of the attributive space. If <1, this indicates resistance: the level of variability of a community is lower than the relative role of environmental factors in the changing of the attributive space. If the ratio =1 (≈1), changes in the community are proportional to the level of the main components of variation in comparison with other components. Ecological factors (both external environmental and internal due to species interactions and which have a neutral nature) cause different levels of community response to their impact. These differences refracted through different aspects of stability of a community can be described using the categories resistance, sensitivity and proportionality. The proposed procedure for quantification of specified properties of sustainability has established that the floodplain soil macrofauna is endowed with resistance to factors that prevail on the level of its variation. However, macrofauna is highly sensitive to minor factors. The community of the soil inhabitants is sensitive to fine-scale variations, which have a neutral nature.

Proceedings of the Biomedical Research Institute named after L. Gorky

1935 ◽  
Vol 31 (5) ◽  
pp. 670-671
Author(s):  
M. Andreev
Keyword(s):  
Environmental Factors ◽  
Biomedical Research ◽  
Twin Studies ◽  
Relative Role ◽  
Institute Of Medicine ◽  
The Third ◽  
Twin Method ◽  
Biomedical Research Institute ◽  
Research Institute

The Third Collection of Works of the Institute of Biology and Medicine (now called the Institute of Medicine and Genetics) contains 20 works; 10 of them are devoted to the study of the relative role of hereditary and environmental factors using the 'twin method' and represent a variety of twin studies.

The relative role of genetic and environmental factors in migraine without aura

Neurology ◽  
1999 ◽  
Vol 53 (5) ◽  
pp. 995-995 ◽  
Author(s):  
M. Gervil ◽  
V. Ulrich ◽  
J. Kaprio ◽  
J. Olesen ◽  
M. B. Russell
Keyword(s):  
Environmental Factors ◽  
Migraine Without Aura ◽  
Relative Role ◽  
Genetic And Environmental Factors

The relative role of environmental, spatial, and land-use patterns in explaining aquatic macrophyte community composition

2011 ◽  
Vol 68 (10) ◽  
pp. 1778-1789 ◽  
Author(s):  
Alison Mikulyuk ◽  
Sapna Sharma ◽  
Scott Van Egeren ◽  
Eric Erdmann ◽  
Michelle E. Nault ◽  
...  
Keyword(s):  
Land Use ◽  
Environmental Factors ◽  
Community Composition ◽  
Spatial Patterns ◽  
Aquatic Plant ◽  
Aquatic Macrophyte ◽  
Plant Distribution ◽  
Relative Role ◽  
Macrophyte Community

Quantifying the relative role of environmental and spatial factors to understand patterns in community composition is a fundamental goal of community ecology. We applied a tested and repeatable point-intercept sampling method to aquatic macrophyte assemblages in 225 Wisconsin lakes to understand the ability of environmental, land-use, and spatial patterns to explain aquatic plant distribution and abundance. Using a variation partitioning framework in conjunction with Moran eigenvector maps we found that environmental, land-use, and spatial patterns explained 31% of total adjusted variation in aquatic macrophyte assemblages across the landscape. Environmental factors were the most important (contributing 34% of the total explained variation), but all sources of variation were statistically significant. Community composition varied from north to south along a gradient of alkalinity and from disturbed to undisturbed lakes, diverging according to whether disturbance was urban or agricultural. The large amount of shared variation among predictor variables suggests causal relationships are complex and emphasizes the importance of considering space and land-use in addition to environmental factors when characterizing macrophyte assemblages. This work is the first to examine the joint and unique effects of environment, land-use, and spatial patterns on aquatic plant communities.

Questions on the role of biofilms for the adaptation of microorganisms to unfavorable environmental factors by the example of P. aeruginosa

2020 ◽  
Vol 99 (4) ◽  
pp. 379-383
Author(s):  
Vasily N. Afonyushkin ◽  
N. A. Donchenko ◽  
Ju. N. Kozlova ◽  
N. A. Davidova ◽  
V. Yu. Koptev ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Environmental Factors ◽  
Barrier Function ◽  
Infectious Agent ◽  
Antagonistic Activity ◽  
The Body ◽  
Main Function ◽  
Pathogenic Potential ◽  
The Face

Pseudomonas aeruginosa is a widely represented species of bacteria possessing of a pathogenic potential. This infectious agent is causing wound infections, fibrotic cystitis, fibrosing pneumonia, bacterial sepsis, etc. The microorganism is highly resistant to antiseptics, disinfectants, immune system responses of the body. The responses of a quorum sense of this kind of bacteria ensure the inclusion of many pathogenicity factors. The analysis of the scientific literature made it possible to formulate four questions concerning the role of biofilms for the adaptation of P. aeruginosa to adverse environmental factors: Is another person appears to be predominantly of a source an etiological agent or the source of P. aeruginosa infection in the environment? Does the formation of biofilms influence on the antibiotic resistance? How the antagonistic activity of microorganisms is realized in biofilm form? What is the main function of biofilms in the functioning of bacteria? A hypothesis has been put forward the effect of biofilms on the increase of antibiotic resistance of bacteria and, in particular, P. aeruginosa to be secondary in charcter. It is more likely a biofilmboth to fulfill the function of storing nutrients and provide topical competition in the face of food scarcity. In connection with the incompatibility of the molecular radii of most antibiotics and pores in biofilm, biofilm is doubtful to be capable of performing a barrier function for protecting against antibiotics. However, with respect to antibodies and immunocompetent cells, the barrier function is beyond doubt. The biofilm is more likely to fulfill the function of storing nutrients and providing topical competition in conditions of scarcity of food resources.

Role of environmental factors in the etiology of hepatocellular carcinoma

2010 ◽  
Vol 151 (28) ◽  
pp. 1132-1136 ◽  
Author(s):  
István Tornai
Keyword(s):  
Hepatocellular Carcinoma ◽  
Hepatitis B Virus ◽  
Environmental Factors ◽  
Hepatitis B ◽  
Hepatitis A ◽  
Virus Hepatitis ◽  
B Virus

A krónikus vírushepatitisek jelentik ma a legismertebb okokat a hepatocellularis carcinoma (HCC) kialakulásában. A krónikus B- és C-vírus-hepatitis a májrákok körülbelül 40-50%-át okozza. A nyugati típusú társadalmakban a HCC előfordulása folyamatosan növekvő tendenciát mutat. Az alkohol számít a környezeti tényezők közül a legfontosabbnak, bár az alkoholfogyasztás a legtöbb országban csökken. Ez aláhúzza az egyéb környezeti tényezők fontosságát is. Az elfogyasztott alkoholmennyiséggel egyenes arányban növekszik a cirrhosis és a következményes HCC gyakorisága nőkben és férfiakban egyaránt. A kémiai anyagok közül a legismertebb a Kínában és Afrikában elterjedt aflatoxin, amely a gabonaféléket szennyező mycotoxin. Hasonló területeken endémiás, mint a hepatitis B-vírus, együtt szinergista hatást fejtenek ki. A dohányzás is egyértelműen bizonyított hepatocarcinogen hatással rendelkezik. Ez is jelentősen fokozódik, ha alkoholfogyasztással vagy vírushepatitisszel társul. Társadalmilag talán a legfontosabb az elhízás, a következményes nem alkoholos zsírmáj, illetve steatohepatitis és a 2-es típusú cukorbetegség, amelyek prevalenciája egyre fokozódik. Feltehetően ezek állnak a növekvő HCC-gyakoriság hátterében. Az inzulinrezisztencia és az oxidatív stressz képezik a legfontosabb patogenetikai lépéseket a májsejtkárosodásban. További fontos rizikótényező az orális fogamzásgátlók elterjedt használata. Egyes foglalkozások esetén a tartós szervesoldószer-expozíció is növeli a HCC rizikóját. Védelmet jelenthetnek az antioxidánsok, a szelén, a gyógyszerek közül a statinok és a feketekávé-fogyasztás.

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