Assessing cercarial transmission of Cyathocotyle bushiensis and Sphaeridiotrema pseudoglobulus by use of sentinel snails

1994 ◽  
Vol 72 (5) ◽  
pp. 885-891 ◽  
Author(s):  
Dwayne A. W. Lepitzki ◽  
Marilyn E. Scott ◽  
J. Daniel McLaughlin
Keyword(s):  
Spatial Heterogeneity ◽  
Temporal Variation ◽  
Spatial And Temporal Variation ◽  
Temporal Differences ◽  
Size Classes ◽  
Naturally Occurring ◽  
Bithynia Tentaculata ◽  
Low Levels ◽  
Different Levels ◽  
Cyathocotyle Bushiensis

Sentinel snails (Bithynia tentaculata) were used to assess spatial and temporal variation in cercarial transmission of Cyathocotyle bushiensis and Sphaeridiotrema pseudoglobulus at two field locations in southern Quebec and southeastern Ontario from mid-August to the end of October, 1989. Sentinels acquired infections with both digeneans; however, low levels of metacercariae of C. bushiensis precluded any conclusions regarding transmission of this parasite from being reached. In contrast, extensive spatial heterogeneity existed in the S. pseudoglobulus – snail system. Sentinel snails within 10 m of each other were apparently exposed to vastly different levels of naturally occurring cercariae. All size classes of sentinels were apparently equally susceptible to cercarial infections but no consistent temporal differences in infection levels were found.

scholarly journals Spatial and Temporal Variation Characteristics of Snowfall in the Haihe River Basin from 1960 to 2016

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1798
Author(s):  
Xu Wu ◽  
Su Li ◽  
Bin Liu ◽  
Dan Xu
Keyword(s):  
Temporal Variation ◽  
River Basin ◽  
Spatial And Temporal Variation ◽  
Haihe River Basin ◽  
Temperature Threshold ◽  
Threshold Method ◽  
Exponential Equation ◽  
Haihe River ◽  
The Haihe River Basin ◽  
Different Levels

The spatio-temporal variation of precipitation under global warming had been a research hotspot. Snowfall is an important part of precipitation, and its variabilities and trends in different regions have received great attention. In this paper, the Haihe River Basin is used as a case, and we employ the K-means clustering method to divide the basin into four sub-regions. The double temperature threshold method in the form of the exponential equation is used in this study to identify precipitation phase states, based on daily temperature, snowfall, and precipitation data from 43 meteorological stations in and around the Haihe River Basin from 1960 to 1979. Then, daily snowfall data from 1960 to 2016 are established, and the spatial and temporal variation of snowfall in the Haihe River Basin are analyzed according to the snowfall levels as determined by the national meteorological department. The results evalueted in four different zones show that (1) the snowfall at each meteorological station can be effectively estimated at an annual scale through the exponential equation, for which the correlation coefficient of each division is above 0.95, and the relative error is within 5%. (2) Except for the average snowfall and light snowfall, the snowfall and snowfall days of moderate snow, heavy snow, and snowstorm in each division are in the order of Zones III > IV > I > II. (3) The snowfall and the number of snowfall days at different levels both show a decreasing trend, except for the increasing trend of snowfall in Zone I. (4) The interannual variation trend in the snowfall at the different levels are not obvious, except for Zone III, which shows a significant decreasing trend.

The Effect of Copper Ions on Clot Lysis Time in the Fibrinolytic Assay of Streptokinase

1965 ◽  
Vol 13 (02) ◽  
pp. 477-483
Author(s):  
Alwin B. Bogert
Keyword(s):  
Copper Ions ◽  
Borate Buffer ◽  
Fibrinolytic System ◽  
Clot Lysis ◽  
Distilled Water ◽  
Naturally Occurring ◽  
Lysis Time ◽  
Low Levels ◽  
Effect Of Copper ◽  
Clot Lysis Time

SummaryExperiments were conducted to determine why different lots of Borate Buffer reagent affect the clot lysis times obtained in the fibrinolytic assay of Streptokinase. Minerals naturally occurring in distilled water were screened individually to determine their influence on lysis. Copper was found to have a very pronounced effect in this regard on the fibrinolytic system in that low levels reduce the lysis time and high levels increase it.

scholarly journals 77 The effect of naturally occurring levels of multiple mycotoxins on growth performance and carcass parameters of grow-finish pigs

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 54-55
Author(s):  
Leigh Ruckman ◽  
Stacie Gould ◽  
John Patience
Keyword(s):  
Growth Performance ◽  
Economic Impact ◽  
Environmental Conditions ◽  
Fixed Effects ◽  
Control Diet ◽  
Naturally Occurring ◽  
Carcass Parameters ◽  
Low Levels ◽  
Dietary Treatments ◽  
Over Time

Abstract Mycotoxins may not be an issue every year, but the proper environmental conditions can cause a spike in contaminated grains and cause severe economic impact on pork producers. The objective of this study was to determine the effect of naturally occurring infections of deoxynivalenol, zearalenone and fumonisins (DZF) on growth performance and carcass parameters in grow/finish pigs. One hundred pigs (BW 34.0 ± 0.9 kg; L337 × Camborough, PIC, Hendersonville, TN) were randomly assigned to 1 of 2 dietary treatments with 10 split-sex pens/treatment. The control diet (CTL) contained low levels of DZF and the CTL+DFZ diet contained high levels of DZF. Diets were fed in 4 phases over the 126-d experiment period. The CTL diet contained 1.6, 1.6, 1.8 and 1.2 mg deoxynivalenol/kg and CTL+DZF contained 9.2, 6.9, 5.8 and 3.8 mg deoxynivalenol/kg in the 4 diet phases, respectively. The CTL contained 0.30, 0.32, 0.51 and 0.32 mg zearalenone/kg and 0.7, 0.8, 0.8 and 0.9 mg total fumonisins/kg; CTL+DFZ contained 0.59, 0.72, 0.86 and 0.57 mg zearalenone/kg and 1.0, 1.1, 1.2 and 0.9 mg total fumonisins/kg for phases one through four, respectively. Data were analyzed using PROC MIXED of SAS (9.4) with treatment, sex, and their interaction as fixed effects. Compared to CTL, feeding CTL+DFZ decreased final BW (130.3 vs 120.5 kg; P< 0.001), ADG (0.95 vs 0.79 kg/d; P< 0.001), ADFI (2.73 vs 2.49 kg/d; P=0.016), and G:F (0.35 vs 0.32; P=0.043). Feeding CTL+DFZ decreased HCW (92.3 vs 89.4 kg; P=0.024) and increased dressing percentage (70.9 vs 74.3%; P=0.009) and tended to reduce loin depth (7.0 vs 6.8 cm; P=0.057) compared to CTL. Diet did not affect backfat depth or lean percentage (P >0.10). In conclusion, diets naturally contaminated with multiple mycotoxins reduced growth performance and adversely affected carcass parameters; pigs did not adapt over time to the mycotoxins.

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