Environmental controls on the distribution of Atrypoidea species in Upper Silurian strata of arctic Canada

1984 ◽  
Vol 21 (2) ◽  
pp. 131-144 ◽  
Author(s):  
Brian Jones ◽  
G. M. Narbonne
Keyword(s):  
Environmental Factors ◽  
Environmental Parameters ◽  
Arctic Canada ◽  
Subtidal Area ◽  
Environmental Controls ◽  
Subtidal Environment ◽  
Close Proximity ◽  
Utmost Care ◽  
Shallow Subtidal ◽  
Upper Silurian

Evidence from numerous localities throughout the Upper Silurian strata of arctic Canada suggests that the ranges of the various species of Atrypoidea were controlled primarily by environmental factors. Atrypoidea bioherma n. sp. occurred only on and immediately around bioherms. Atrypoidea foxi inhabited subtidal areas in an offshore position, and especially those areas between the bioherms with which A. bioherma were associated. Atrypoidea phoca apparently lived in a shallow subtidal area in close proximity to the shoreline. Atrypoidea erebus inhabited environments ranging from the low intertidal to shallow subtidal. Atrypoidea netserki lived in a shallow subtidal environment close to shore.Fluctuations in bathymetry and other environmental parameters during the deposition of the Upper Silurian strata resulted in an apparent zonation of Atrypoidea species. These zones, however, are ecologically controlled and can therefore only be utilized for biostratigraphic purposes with the utmost care.

Silurian trilobites from arctic Canada

1979 ◽  
Vol 116 (1) ◽  
pp. 1-19 ◽  
Author(s):  
A. T. Thomas ◽  
G. M. Narbonne
Keyword(s):  
New Species ◽  
Arctic Canada ◽  
Subtidal Environment ◽  
Storm Wave ◽  
Shallow Subtidal ◽  
Cornwallis Island

SummaryTrilobites of upper Ludlow age are described from Member A of the Read Bay Formation on Cornwallis Island. Four new species are represented: Helokybe spio gen. et sp.nov. (Dechenellinae), Encrinurus hyperboreus sp. nov., Kailia? capra sp.nov. (Encrinurinae) and Hemiarges echinatus sp.nov. Other taxa present are: an effaced scutelluid; Cyphaspis sp.; a warburgelline; two more encrinurids; two other forms of Hemiarges. The trilobites occur in sediments indicative of a shallow subtidal environment, with the exception of the warburgelline which occurs in sediments deposited under deeper subtidal conditions below storm wave-base.

scholarly journals Predicting the Presence of Leptospires in Rodents from Environmental Indicators Opens Up Opportunities for Environmental Monitoring of Human Leptospirosis

2021 ◽  
Vol 13 (2) ◽  
pp. 325
Author(s):  
Leon Biscornet ◽  
Christophe Révillion ◽  
Sylvaine Jégo ◽  
Erwan Lagadec ◽  
Yann Gomard ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Environmental Factors ◽  
Control Strategies ◽  
Sampling Site ◽  
Rattus Rattus ◽  
Environmental Parameters ◽  
Environmental Indicators ◽  
Small Island ◽  
Urban Landscapes ◽  
Infection Prevalence

Leptospirosis, an environmental infectious disease of bacterial origin, is the infectious disease with the highest associated mortality in Seychelles. In small island territories, the occurrence of the disease is spatially heterogeneous and a better understanding of the environmental factors that contribute to the presence of the bacteria would help implement targeted control. The present study aimed at identifying the main environmental parameters correlated with animal reservoirs distribution and Leptospira infection in order to delineate habitats with highest prevalence. We used a previously published dataset produced from a large collection of rodents trapped during the dry and wet seasons in most habitats of Mahé, the main island of Seychelles. A land use/land cover analysis was realized in order to describe the various environments using SPOT-5 images by remote sensing (object-based image analysis). At each sampling site, landscape indices were calculated and combined with other geographical parameters together with rainfall records to be used in a multivariate statistical analysis. Several environmental factors were found to be associated with the carriage of leptospires in Rattus rattus and Rattus norvegicus, namely low elevations, fragmented landscapes, the proximity of urbanized areas, an increased distance from forests and, above all, increased precipitation in the three months preceding trapping. The analysis indicated that Leptospira renal carriage could be predicted using the species identification and a description of landscape fragmentation and rainfall, with infection prevalence being positively correlated with these two environmental variables. This model may help decision makers in implementing policies affecting urban landscapes and/or in balancing conservation efforts when designing pest control strategies that should also aim at reducing human contact with Leptospira-laden rats while limiting their impact on the autochthonous fauna.

scholarly journals Risk and Environmental Factors Associated with the Presence of Canine Parvovirus Type 2 in Diarrheic Dogs from Thessaly, Central Greece

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 590
Author(s):  
Maria Kantere ◽  
Labrini V. Athanasiou ◽  
Alexios Giannakopoulos ◽  
Vassilis Skampardonis ◽  
Marina Sofia ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Clinical Symptoms ◽  
Gastrointestinal Disease ◽  
Environmental Parameters ◽  
Canine Parvovirus ◽  
Geographical Information ◽  
Factors Associated ◽  
Working Dogs ◽  
Canine Parvovirus Type 2

Canine parvovirus type 2 (CPV-2) primarily infects dogs, which are the main host reservoir, causing severe gastrointestinal disease associated with immunosuppression. The present study was conducted in Thessaly, Greece and aimed to identify risk and environmental factors associated with CPV-2 infection in diarrheic dogs. Fecal samples were collected from 116 dogs presenting diarrhea and were tested by polymerase chain reaction (PCR) for the presence of CPV-2 DNA. Supplementary data regarding clinical symptoms, individual features, management factors and medical history were also gathered for each animal during clinical evaluation. Sixty-eight diarrheic dogs were found to be positive for the virus DNA in their feces. Statistical analysis revealed that CPV-2 DNA was less likely to be detected in senior dogs, while working dogs, namely hounds and shepherds, had higher odds to be positive for the virus. Livestock density and land uses, specifically the categories of discontinuous urban fabric and of human population density, were identified as significant environmental parameters associated with CPV-2 infection by using Geographical Information System (GIS) together with the Ecological Niche Model (ENM). This is the first description of the environmental variables associated with the presence of CPV-2 DNA in dogs’ feces in Greece.

scholarly journals Relationships between Environmental Factors and Pathogenic Vibrios in the Northern Gulf of Mexico

2010 ◽  
Vol 76 (21) ◽  
pp. 7076-7084 ◽  
Author(s):  
C. N. Johnson ◽  
A. R. Flowers ◽  
N. F. Noriea ◽  
A. M. Zimmerman ◽  
J. C. Bowers ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Water Column ◽  
Vibrio Vulnificus ◽  
Environmental Parameters ◽  
Sampling Period ◽  
Pathogenicity Factor ◽  
Hemolysin Gene ◽  
Thermostable Direct Hemolysin ◽  
Pathogenic Vibrios ◽  
Abundance And Distribution

ABSTRACT Although autochthonous vibrio densities are known to be influenced by water temperature and salinity, little is understood about other environmental factors associated with their abundance and distribution. Densities of culturable Vibrio vulnificus containing vvh (V. vulnificus hemolysin gene) and V. parahaemolyticus containing tlh (thermolabile hemolysin gene, ubiquitous in V. parahaemolyticus), tdh (thermostable direct hemolysin gene, V. parahaemolyticus pathogenicity factor), and trh (tdh-related hemolysin gene, V. parahaemolyticus pathogenicity factor) were measured in coastal waters of Mississippi and Alabama. Over a 19-month sampling period, vibrio densities in water, oysters, and sediment varied significantly with sea surface temperature (SST). On average, tdh-to-tlh ratios were significantly higher than trh-to-tlh ratios in water and oysters but not in sediment. Although tlh densities were lower than vvh densities in water and in oysters, the opposite was true in sediment. Regression analysis indicated that SST had a significant association with vvh and tlh densities in water and oysters, while salinity was significantly related to vibrio densities in the water column. Chlorophyll a levels in the water were correlated significantly with vvh in sediment and oysters and with pathogenic V. parahaemolyticus (tdh and trh) in the water column. Furthermore, turbidity was a significant predictor of V. parahaemolyticus density in all sample types (water, oyster, and sediment), and its role in predicting the risk of V. parahaemolyticus illness may be more important than previously realized. This study identified (i) culturable vibrios in winter sediment samples, (ii) niche-based differences in the abundance of vibrios, and (iii) predictive signatures resulting from correlations between environmental parameters and vibrio densities.

scholarly journals The impact of environmental variables on the spread of COVID-19 in the Republic of Korea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong Kwan Lim ◽  
Oh Joo Kweon ◽  
Hye Ryoun Kim ◽  
Tae-Hyoung Kim ◽  
Mi-Kyung Lee
Keyword(s):  
Environmental Factors ◽  
Virus Disease ◽  
Environmental Parameters ◽  
Environmental Data ◽  
Republic Of Korea ◽  
Metropolitan Region ◽  
Health Concern ◽  
Ozone Level ◽  
The Republic ◽  
The Impact

AbstractCorona virus disease 2019 (COVID-19) has been declared a global pandemic and is a major public health concern worldwide. In this study, we aimed to determine the role of environmental factors, such as climate and air pollutants, in the transmission of COVID-19 in the Republic of Korea. We collected epidemiological and environmental data from two regions of the Republic of Korea, namely Seoul metropolitan region (SMR) and Daegu-Gyeongbuk region (DGR) from February 2020 to July 2020. The data was then analyzed to identify correlations between each environmental factor with confirmed daily COVID-19 cases. Among the various environmental parameters, the duration of sunshine and ozone level were found to positively correlate with COVID-19 cases in both regions. However, the association of temperature variables with COVID-19 transmission revealed contradictory results when comparing the data from SMR and DGR. Moreover, statistical bias may have arisen due to an extensive epidemiological investigation and altered socio-behaviors that occurred in response to a COVID-19 outbreak. Nevertheless, our results suggest that various environmental factors may play a role in COVID-19 transmission.

Floristic study and assessment of the environmental factors governing the distribution of riparian plants in the Zat sub-Basin: Tensift Watershed, Morocco

2020 ◽  
Vol 45 (2) ◽  
pp. 7900-7915
Author(s):  
Mostakim Lahcen ◽  
Fetnassi Nidal ◽  
Ghamizi Mohamed
Keyword(s):  
Environmental Factors ◽  
Pearson Correlation ◽  
Ecological Status ◽  
Environmental Parameters ◽  
Quality Parameters ◽  
Phosphorus Concentration ◽  
Factors Affecting ◽  
Riparian Plants ◽  
Emergent Plants ◽  
Significant Difference

Measuring the phytodiversity and determining environmental factors affecting the abundance and distribution of riparian plants of Zat sub-basin in Morocco were carried out in this study. A hypothesis was tested whether there is any statistically significant difference in environmental parameters and plants communities among the Zat River and its tributaries. For this purpose, water quality parameters such as temperature, pH, salinity, electrical conductivity, Dissolved Oxygen, nitrate and phosphorus concentration, and riparian plants diversity were estimated at 17 stations along the Zat River and its tributaries during the periods (2018 and 2019). The Canonical Correspondence Analysis (CCA) and Pearson correlation were preformed to assess the relationship between environmental parameters, and the distribution and abundance of riparian plants inventoried. The presence of 113 species was recorded, distributed between 43 families and 97 genera, 9 of which were floating-leaved, 24 submerged, and 80 emergent plants. The rare and threatened species inventoried were represented by 7 taxa, whereas 6 species are reported as endemic. Raunkiaer classification showed a dominance of therophytes (38.39%) over the other groups. According to CCA, the abiotic parameters (DO, elevation, salinity and nitrate concentration) were statistically significant parameters governing the distribution and abundance of the riparian plants inventoried. The results obtained reveal the state of the riparian vegetation in the Zat subBasin, therefore we can consider them as a reliable component for the assessment of the ecological status of the aquatic environment.

scholarly journals Environmental controls on the <i>Emiliania huxleyi</i> calcite mass

2014 ◽  
Vol 11 (8) ◽  
pp. 2295-2308 ◽  
Author(s):  
M. T. Horigome ◽  
P. Ziveri ◽  
M. Grelaud ◽  
K.-H. Baumann ◽  
G. Marino ◽  
...  
Keyword(s):  
Seawater Temperature ◽  
World Ocean ◽  
Environmental Parameters ◽  
Abundant Species ◽  
Emiliania Huxleyi ◽  
Ion Concentration ◽  
Carbonate Chemistry ◽  
Environmental Controls ◽  
Carbonate Ion ◽  
Phosphate Availability

Abstract. Although ocean acidification is expected to impact (bio) calcification by decreasing the seawater carbonate ion concentration, [CO32−], there is evidence of nonuniform response of marine calcifying plankton to low seawater [CO32−]. This raises questions about the role of environmental factors other than acidification and about the complex physiological responses behind calcification. Here we investigate the synergistic effect of multiple environmental parameters, including seawater temperature, nutrient (nitrate and phosphate) availability, and carbonate chemistry on the coccolith calcite mass of the cosmopolitan coccolithophore Emiliania huxleyi, the most abundant species in the world ocean. We use a suite of surface (late Holocene) sediment samples from the South Atlantic and southwestern Indian Ocean taken from depths lying above the modern lysocline (with the exception of eight samples that are located at or below the lysocline). The coccolith calcite mass in our results presents a latitudinal distribution pattern that mimics the main oceanographic features, thereby pointing to the potential importance of seawater nutrient availability (phosphate and nitrate) and carbonate chemistry (pH and pCO2) in determining coccolith mass by affecting primary calcification and/or the geographic distribution of E. huxleyi morphotypes. Our study highlights the importance of evaluating the combined effect of several environmental stressors on calcifying organisms to project their physiological response(s) in a high-CO2 world and improve interpretation of paleorecords.

scholarly journals Effects of environmental factors on Tigriopus fulvus, Fischer 1860, a Mediterranean harpacticoid copepod

2018 ◽  
Vol 91 (1) ◽  
Author(s):  
Guido Bonello ◽  
Cristiano Angelini ◽  
Luigi Pane
Keyword(s):  
Climate Change ◽  
Life Cycle ◽  
Environmental Factors ◽  
Population Density ◽  
Harpacticoid Copepod ◽  
Environmental Parameters ◽  
Chemical Parameters ◽  
Climate Change Effects ◽  
Physical Chemical ◽  
Extinction Event

Tigriopus fulvus (Fischer, 1860) is a benthic harpacticoid copepod of the Mediterranean supralittoral zone. The transitional characteristics of this environment forced this species to develop high resistance to changes of environmental parameters. Nevertheless, Tigriopus fulvus life-cycle is influenced from the splashpools physical-chemical parameters. In this paper, we present the results of a supralittoral monitoring performed in 2014, confirming the influence of some of these environmental parameters on population buildups. Because of recent worldwide climate change effects, a threat might have been posed on this particularly exposed organism, whose population density decreased of a sixfold value in the last 30 years. During the three pools (A, B, C) monitoring, the maximum copepod density recorded was 1456 Ind/l (September 2014, Pool C), alongside first records of extinction event for Tigriopus fulvus.

Highly stretchable and sensitive strain sensors based on carbon nanotube–elastomer nanocomposites: the effect of environmental factors on strain sensing performance

2020 ◽  
Vol 8 (18) ◽  
pp. 6185-6195 ◽  
Author(s):  
Mohammad Nankali ◽  
Norouz Mohammad Nouri ◽  
Mahdi Navidbakhsh ◽  
Nima Geran Malek ◽  
Mohammad Amin Amindehghan ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Environmental Factors ◽  
Environmental Parameters ◽  
Strain Sensors ◽  
Sensitive Strain ◽  
Effect Of Temperature ◽  
Strain Sensing ◽  
Highly Stretchable ◽  
The Impact ◽  
Sensing Performance

The impact of environmental parameters on the sensing behavior of carbon nanotube–elastomer nanocomposite strain sensors has been investigated, revealing significant effect of temperature and humidity variations on the sensing performance.

scholarly journals ENVIRONMENTAL CONTROLS ON LITTORAL SAND TRANSPORT

1988 ◽  
Vol 1 (21) ◽  
pp. 92 ◽  
Author(s):  
Paul D. Komar
Keyword(s):  
Environmental Factors ◽  
Field Data ◽  
Measurement Techniques ◽  
Breaking Waves ◽  
Total Power ◽  
Sand Transport ◽  
Longshore Current ◽  
Data Set ◽  
Environmental Controls ◽  
Gravel Beaches

Quantities of sand transported along beaches are generally related to the "longshore component of wave power", F^, through the proportionality is = KF£ where l8 is the immersed-weight sand transport rate and K is a dimensionless proportionality factor. A more-generally applicable relationship is that of Bagnold, ls = K'(ECn)bvL/um where (ECn)b is the energy flux or total power of the breaking waves, y^ is the longshore current, um is the mean orbital velocity under the waves, and K' is another dimensionless coefficient. It is apparent that sediment transport rates on beaches should depend on environmental factors such as the grain diameter or settling velocity, and possibly on factors such as the beach slope or wave steepness. However, examinations of such dependencies for K and K' within the field data are hampered by problems with large random scatter within any one data set, and by systematic differences between separate studies which have employed diverse measurement techniques. Examinations of the field data for K and K' variations indicate that meaningful dependencies on sediment grain diameters and other factors cannot be established with confidence in the sand-size range. Limited data available from gravel beaches support the expected decreases in K and K' with increasing grain sizes. These data are too few in numbers to establish firm trends, but do suggest that future investigations to establish dependencies on environmental factors would be most profitably undertaken on gravel beaches. The measurements collected in recent years from sand beaches suggest revisions in average K and K' coefficients to be used in transport evaluations, but such revisions must be coordinated such that K/K' = 2.7 so as to maintain agreement with the longshore current data.

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