Spatial patterns in brown bear Ursus arctos diet: the role of geographical and environmental factors

Mammal Review ◽  
2011 ◽  
Vol 42 (2) ◽  
pp. 120-143 ◽  
Author(s):  
Katarzyna BOJARSKA ◽  
Nuria SELVA
Keyword(s):  
Environmental Factors ◽  
Spatial Patterns ◽  
Ursus Arctos ◽  
Brown Bear

scholarly journals The Role of Brown Bear (Ursus arctos) in the Plant Seed Dispersal of Golestan National Park

2018 ◽  
Vol 7 (2) ◽  
pp. 29-42
Author(s):  
S. karimi ◽  
M.R. Hemami ◽  
M. Tarkesh Esfahani ◽  
Ch. Baltzinger ◽  
◽  
...  
Keyword(s):  
Seed Dispersal ◽  
National Park ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Plant Seed

scholarly journals Seasonal Pattern of Prevalence and Excretion of Eggs of Baylisascaris transfuga in the Brown Bear (Ursus arctos)

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2428
Author(s):  
Ladislav Molnár ◽  
Alžbeta Königová ◽  
Peter Major ◽  
Zuzana Vasilková ◽  
Martina Tomková ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Seasonal Dynamics ◽  
Ursus Arctos ◽  
Seasonal Pattern ◽  
Brown Bear ◽  
Seasonal Prevalence ◽  
Mean Intensity ◽  
Mean Temperature ◽  
The Mean ◽  
Baylisascaris Transfuga

The seasonal dynamics of the prevalence, abundance, and mean intensity of egg excretion by the nematode parasite Baylisascaris transfuga in the European brown bear (Ursus arctos) were monitored relative to environmental factors (mean temperature, humidity, and temperature) over three years. The prevalence, abundance, and mean intensity of egg excretion tended to increase from spring to autumn throughout the monitoring period. The seasonal prevalence (84.2–90.6%), abundance (470.2–545.3 eggs per gramme (EPG) of faeces), mean intensity of excretion (558.3–602.1 EPG), and number of eggs (1150 EPG) were highest in autumn. The prevalence of eggs (up to 48.5%), abundance (37.8–60.6 EPG), and mean intensity of excretion (94.4–125.0 EPG) were high in winter, despite the period of hibernation. The seasonal dynamics of B. transfuga abundance in bears, the mean temperature between spring and autumn, and the seasonal trend of increase in intensity of egg excretion with temperature from winter to summer were interrelated. Abundance differed significantly between winter and autumn, spring and autumn, and summer and autumn (p < 0.0001) in all years and between spring and summer in 2016 (p < 0.005), 2017 (p < 0.05). B. transfuga abundance differed significantly between the seasons over the three years only in spring (p ≤ 0.0001).

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.

Brown Bear (Ursus arctos) Habitat Use and Food Resources on Elmendorf Air Force Base, Alaska

2007 ◽  
Author(s):  
Sean D. Farley ◽  
Herman Griese ◽  
Rick Sinnott ◽  
Jessica Coltrane ◽  
Chris Garner ◽  
...  
Keyword(s):  
Habitat Use ◽  
Air Force ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Food Resources ◽  
Air Force Base

scholarly journals Impact of Environmental Factors on Stilbene Biosynthesis

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 90
Author(s):  
Alessio Valletta ◽  
Lorenzo Maria Iozia ◽  
Francesca Leonelli
Keyword(s):  
Environmental Factors ◽  
Biosynthetic Pathway ◽  
In Planta ◽  
Organ Cultures ◽  
Related Plant ◽  
Valuable Compounds ◽  
Stilbene Compounds ◽  
Stilbene Biosynthesis ◽  
Abiotic Environmental Factors

Stilbenes are a small family of polyphenolic secondary metabolites that can be found in several distantly related plant species. These compounds act as phytoalexins, playing a crucial role in plant defense against phytopathogens, as well as being involved in the adaptation of plants to abiotic environmental factors. Among stilbenes, trans-resveratrol is certainly the most popular and extensively studied for its health properties. In recent years, an increasing number of stilbene compounds were subjected to investigations concerning their bioactivity. This review presents the most updated knowledge of the stilbene biosynthetic pathway, also focusing on the role of several environmental factors in eliciting stilbenes biosynthesis. The effects of ultraviolet radiation, visible light, ultrasonication, mechanical stress, salt stress, drought, temperature, ozone, and biotic stress are reviewed in the context of enhancing stilbene biosynthesis, both in planta and in plant cell and organ cultures. This knowledge may shed some light on stilbene biological roles and represents a useful tool to increase the accumulation of these valuable compounds.

Sign in / Sign up

Export Citation Format

Share Document