Decline of Native Unionid Bivalves in Lake St. Clair After Infestation by the Zebra Mussel, Dreissena polymorpha

1994 ◽  
Vol 51 (10) ◽  
pp. 2227-2233 ◽  
Author(s):  
Thomas F. Nalepa
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Extended Period ◽  
Light Weight ◽  
Short Term ◽  
Slow Increase ◽  
The Mean ◽  
The Relationship

To determine impacts of the zebra mussel, Dreissena polymorpha, on bivalves in Lake St. Clair, densities of Unionidae in 1990 and 1992 (after D. polymorpha invasion) were compared with densities in 1986 (before D. polymorpha). Declines in density occurred mainly at sites in the southeastern portion of the lake where unionids were highly infested with D. polymorpha. Unionid densities at highly infested sites declined from 2.4/m2 in 1986, to 1.8/m2 in 1990, and to 0/m2 in 1992. Unionid species with light-weight shells that brood larvae over an extended period declined more between 1986 and 1990 than heavy-shelled, short-term brooders. Unionid densities at lightly infested sites located mainly in the northwestern portion of the lake did not decline: mean densities were 1.4/m2 in 1986, 1.6/m2 in 1990, and 1.4/m2 in 1992. While the mean number of D. polymorpha per unionid was <1 at these lightly infested sites in 1990, it increased to 35 by 1992. Given this relatively slow increase in D. polymorpha per unionid in this portion of the lake, continued monitoring of populations should provide a better understanding of the relationship between the extent of infestations and unionid mortality.

Evaluation of the Efficacy of ST2 and NT-proBNP in the Diagnosis and Prediction of Short- Term Prognosis in Heart Failure with Reduced Ejection Fraction

2017 ◽  
Vol 9 (04) ◽  
Author(s):  
Shivananda B Nayak ◽  
Dharindra Sawh ◽  
Brandon Scott ◽  
Vestra Sears ◽  
Kareshma Seebalack ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Cardiac Biomarkers ◽  
Double Blind Study ◽  
Short Term ◽  
Double Blind ◽  
Reduced Ejection Fraction ◽  
The Mean ◽  
Design And Methods ◽  
The Relationship

Purpose: i) To determine the relationship between the cardiac biomarkers ST2 and NT-proBNP with ejection fraction (EF) in heart failure (HF) patients. ii) Assess whether a superiority existed between the aforementioned cardiac markers in diagnosing the HF with reduced EF. iii) Determine the efficacy of both biomarkers in predicting a 30-day cardiovascular event and rehospitalization in patients with HF with reduced EF iv) To assess the influence of age, gender, BMI, anaemia and renal failure on the ST2 and NT-proBNP levels. Design and Methods: A prospective double-blind study was conducted to obtain data from a sample of 64 cardiology patients. A blood sample was collected to test for ST2 and NT-proBNP. An echocardiogram (to obtain EF value), electrocardiogram and questionnaire were also obtained. Results: Of the 64 patients enrolled, 59.4% of the population had an EF less than 40%. At the end of the 30- day period, 7 patients were warded, 37 were not warded, one died and 17 were non respondent. Both biomarkers were efficacious at diagnosing HF with a reduced EF. However, neither of them were efficacious in predicting 30-day rehospitalization. The mean NT-proBNP values being: not rehospitalized (2114.7486) and 30 day rehospitalization (1008.42860) and the mean ST2 values being: not rehospitalized (336.1975), and 30-day rehospitalization. (281.9657). Conclusion: Neither ST2 or NT-proBNP was efficacious in predicting the short- term prognosis in HF with reduced EF. Both however were successful at confirming the diagnosis of HF in HF patients with reduced EF.

scholarly journals The Serum High-Sensitive C Reactive Protein and Homocysteine Levels to Evaluate the Prognosis of Acute Ischemic Stroke

2007 ◽  
Vol 2007 ◽  
pp. 1-5 ◽  
Author(s):  
Tahir Yoldas ◽  
Murat Gonen ◽  
Ahmet Godekmerdan ◽  
Fulya Ilhan ◽  
Ednan Bayram
Keyword(s):  
Ischemic Stroke ◽  
Clinical Status ◽  
Elevated Serum ◽  
Short Term ◽  
Reactive Protein ◽  
Control Subjects ◽  
Common Causes ◽  
Healthy Control ◽  
The Mean ◽  
The Relationship

Ischemic stroke is one of the most common causes of death worldwide and is most often caused by thrombotic processes. We investigated the changes in hsCRP and homocysteine levels, two of these risk factors, during the acute period of ischemic stroke and evaluated the relationship between these levels and the short-term prognosis. HsCRP and homocysteine levels were measured at the 2nd, 5th, and 10th days in forty patients admitted within second of an ischemic stroke. The clinical status of the patients was simultaneously evaluated with the Scandinavian stroke scale. The results were compared with 40 healthy control subjects whose age and sex were matched with the patients. The mean hsCRP levels of the patients were9.4±7.0mg/L on the 2nd day,11.0±7.4mg/L on the 5th day, and9.2±7.0mg/L on the 10th day. The mean hsCRP level of the control subjects was1.7±2.9mg/L. The mean hsCRP levels of the patients on the 2nd, 5th, and 10th days were significantly higher than the control subjects (P<.001). The patients' mean homocysteine levels were40.6±9.6μmol/L on the 2nd day,21.7±11.1μmol/L on the 5th day, and20.7±9.2μmol/L on the 10th day. The mean homocysteine level of the control subjects was11.2±1.1μmol/L. The homocysteine levels of the patients were higher than the control subjects at all times (P<.01). In conclusion, patients with stroke have a higher circulating serum hsCRP and homocysteine levels. Short-term unfavorable prognosis seems to be associated with elevated serum hsCRP levels in patients with stroke. Although serum homocysteine was found to be higher, homocysteine seems not related to prog nosis.

A method for reconstruction of zebra mussel (Dreissena polymorpha) length from shell fragments

1992 ◽  
Vol 70 (12) ◽  
pp. 2486-2490 ◽  
Author(s):  
Diana J. Hamilton
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Lake Erie ◽  
Strong Relationship ◽  
Zebra Mussels ◽  
Selective Predation ◽  
Diving Ducks ◽  
Point Pelee ◽  
The Relationship ◽  
Shell Fragments

Zebra mussels (Dreissena polymorpha) are subject to size-selective predation by several species of diving ducks and fish in Europe and North America. Ingested mussels are crushed, but the internal septum in the umbonal region of the mussel usually remains intact. Using mussels collected at Point Pelee, Lake Erie, I showed that there is a strong relationship between the length of the septum and of the mussel (r2 = 0.96). I compared this with a similar relationship developed for European zebra mussels and tested both models on mussels collected from Point Pelee and from Stoney Point, Lake St. Clair. Septal length relative to mussel length was greatest at Stoney Point and least at Point Pelee. The European estimates fell between the two. I concluded that to obtain accurate estimates of mussel length when investigating size-selective predation on zebra mussels, the relationship between mussel and septal lengths should be determined at each study location.

scholarly journals Analysis and Prediction on Vehicle Ownership Based on an Improved Stochastic Gompertz Diffusion Process

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Huapu Lu ◽  
He Ma ◽  
Zhiyuan Sun ◽  
Jing Wang
Keyword(s):  
Differential Equation ◽  
Stochastic Differential Equation ◽  
Real Data ◽  
Vehicle Ownership ◽  
Short Term ◽  
Slow Increase ◽  
Gompertz Equation ◽  
Initial Stage ◽  
New Process ◽  
The Relationship

This paper aims at introducing a new improved stochastic differential equation related to Gompertz curve for the projection of vehicle ownership growth. This diffusion model explains the relationship between vehicle ownership and GDP per capita, which has been studied as a Gompertz-like function before. The main innovations of the process lie in two parts: by modifying the deterministic part of the original Gompertz equation, the model can present the remaining slow increase when the S-shaped curve has reached its saturation level; by introducing the stochastic differential equation, the model can better fit the real data when there are fluctuations. Such comparisons are carried out based on data from US, UK, Japan, and Korea with a time span of 1960–2008. It turns out that the new process behaves better in fitting curves and predicting short term growth. Finally, a prediction of Chinese vehicle ownership up to 2025 is presented with the new model, as China is on the initial stage of motorization with much fluctuations in growth.

scholarly journals Short-term effects of metals on the filtration rate of the zebra mussel Dreissena polymorpha

1994 ◽  
Vol 84 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Michiel H.S. Kraak ◽  
Merel Toussaint ◽  
Daphna Lavy ◽  
C. Davids
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Filtration Rate ◽  
Short Term ◽  
Short Term Effects

A wall jet to measure the attachment strength of zebra mussels

1995 ◽  
Vol 52 (1) ◽  
pp. 126-135 ◽  
Author(s):  
Josef Daniel Ackerman ◽  
C. Ross Ethier ◽  
Jan K. Spelt ◽  
D. Grant Allen ◽  
Catherine M. Cottrell
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Zebra Mussels ◽  
Artificial Substrates ◽  
Environmentally Benign ◽  
Wall Jet ◽  
Dreissena Bugensis ◽  
Marine Bivalves ◽  
Attachment Strength ◽  
The Mean

A wall jet is presented as a novel means of measuring the attachment strength of zebra mussels. Attachment strength was inferred from a fluid detachment parameter (DP), defined as the nominal wall shear stress at the detachment site × mussel length2. DP varied significantly on natural and artificial substrates: in tests with 288 Dreissena bugensis (≈8–10 mm long), the mean (±SE) DP was 8.9 ± 0.9 mPa∙m2 on limestone/dolomite, 5.6 ± 0.5 mPa∙m2 on polyvinylchloride, 4.3 ± 0.4 mPa∙m2 on stainless steel, 4.2 ± 0.5 mPa∙m2 on aluminum, and 2.5 ± 0.3 mPa∙m2 on polymethylmethacrylate (Plexiglas). The attachment strength of postlarval mussels (plantigrades; <1 mm) was two orders of magnitude less than adult mussels. These results were validated with conventional tensile loadings, in which 633 Dreissena bugensis and 26 Dreissena polymorpha were pulled off substrates with a calibrated force scale. The tensile loadings results were comparable with those of marine bivalves. Good correlation between pull-off force and DP was observed. Information of this nature is useful for the implementation of environmentally benign zebra mussel controls.

Effects of current velocity on byssal-thread production in the zebra mussel (Dreissena polymorpha)

1996 ◽  
Vol 74 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Michael Clarke ◽  
Robert F. McMahon
Keyword(s):  
Shell Length ◽  
Current Velocity ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Wild Population ◽  
Byssal Thread ◽  
In The Wild ◽  
The Mean ◽  
Experimental Subjects ◽  
Similarities And Differences

The effect of current velocity on byssal-thread production by adult zebra mussels (Dreissena polymorpha) was investigated. The number of threads produced by 20 individuals at currents of 0.10, 0.15, 0.20, 0.27 m/s was recorded daily over 21 consecutive days, after which individual shell length and dry tissue masses were measured and the byssal complex was removed. Increasing the current velocity from 0.10 to 0.20 m/s significantly elevated rates of byssal-thread production, but the rate was reduced at 0.27 m/s. Current-induced suppression of byssal-thread production may be due to mechanical disturbance of attached mussels, interfering with their ability to press the tip of the foot against the substratum as the thread cures. The mean thread number in a newly formed byssal complex after 21 days was 52.5, 63.8, 73.3 and 60.4 at currents of 0.10, 0.15, 0.20 and 0.27 m/s, respectively. Current velocity had no effect on thread width. The mean number of threads found in the byssal complex of individuals from the wild taken from the same population from which experimental subjects were drawn was 148.3/mussel. There was no correlation between thread number and shell length in the wild population. Results indicate that there are both similarities and differences in the response of byssal-thread production to variable current velocity in freshwater dreissenids and marine mytilids.

scholarly journals Cardiovascular, respiratory, gastrointestinal and behavioral effects of intravenous lidocaine in healthy, conscious horses and evaluation of the relationship with lidocaine and monoethylglycinexylidide serum concentrations

2019 ◽  
Vol 88 (2) ◽  
pp. 67-76
Author(s):  
A. Salciccia ◽  
M. Lopez Arevalo ◽  
A. Maes ◽  
S. Croubels ◽  
V. Busoni ◽  
...  
Keyword(s):  
Serum Concentrations ◽  
Intravenous Lidocaine ◽  
Short Term ◽  
Non Invasive ◽  
Lidocaine Concentration ◽  
Blood Pressures ◽  
The Mean ◽  
Clinically Significant ◽  
The Relationship ◽  
Rate Infusion

This study aimed to evaluate the relationship between the serum concentrations of lidocaine/ monoethylglycinexylidide (MEGX) and their effects on several systems in horses. Five healthy, conscious horses received a two-hour placebo intravenous infusion followed by a two-hour lidocaine infusion (bolus of 1.3 mg/kg over ten minutes followed by a continuous rate infusion of 0.05 mg/kg/min). Lidocaine and MEGX serum concentrations were sampled every ten to fifteen minutes during the experiment, and the presence of muscle fasciculations and loss of balance as well as the respiratory, digestive and cardiovascular systems of the five horses were evaluated by means of different non-invasive methods. During the lidocaine infusion, the mean (± SD) lidocaine and MEGX concentrations were respectively 768.88 ± 93.32ng/ml and 163.08 ± 108.98 ng/ml. The infusion of lidocaine significantly influenced the presence of fasciculations, caused a statistically but non-clinically significant decrease of systolic and diastolic blood pressures, which were both correlated with lidocaine and MEGX serum concentrations, and it increased the duodenal contractions frequency, which was correlated with the serum lidocaine concentration. In this study, mild hypotensive and prokinetic effects of short-term lidocaine infusion were observed.

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