The interaction between shellfish culture and ecosystem processes

2001 ◽  
Vol 58 (5) ◽  
pp. 991-1002 ◽  
Author(s):  
Aad Smaal ◽  
Marnix van Stralen ◽  
Egbertha Schuiling
Keyword(s):  
Primary Production ◽  
Negative Correlation ◽  
Large Scale ◽  
Standing Stock ◽  
Significant Negative Correlation ◽  
Engineering Project ◽  
Phytoplankton Species Composition ◽  
Before And After ◽  
Shellfish Culture ◽  
Annual Primary Production

The carrying capacity of the Oosterschelde ecosystem for the production of mussels (Mytilus edulis) was evaluated before and after completion of a large-scale coastal engineering project in 1987. This project caused hydrodynamic and water-quality changes; hence, phytoplankton-species composition changed and phytoplankton turnover increased, but primary production remained the same. In the prebarrier period (1980–1986), condition of mussels showed a significant negative correlation with the annual shellfish standing stock and a significant positive correlation with the annual primary production. The system was exploited at maximum capacity. In the postbarrier period (1987–1997), the significant correlation between mussel condition and primary production remained, but there was no longer a negative correlation between standing stock and condition. This indicates overstocking, but yields were maintained. This was explained by (i) feedbacks of the mussels in the Oosterschelde ecosystem—through their large filtration and nitrogen-regeneration capacity, increased phytoplankton turnover was induced; and (ii) adaptation to the new conditions by the shellfish farmers in their management of the mussel stocks. It was concluded that feedbacks by filter feeders and farmers have to be addressed in estimating the exploitation capacity of ecosystems.

scholarly journals P0299EVALUATION OF THE CORRELATION BETWEEN VITAMIN D LEVELS AND THROMBOCYTE MARKERS IN PATIENTS WITH DİALYSİS, CHRONIC RENAL DISEASE AND RENAL TRANSPLANTATION PATIENTS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
KÖNÜL AHMEDOVA ◽  
Garip SAHIN ◽  
Cengiz Bal ◽  
Rüya Mutluay
Keyword(s):  
Vitamin D ◽  
Renal Transplantation ◽  
Renal Disease ◽  
Negative Correlation ◽  
Chronic Renal Disease ◽  
Significant Negative Correlation ◽  
Vitamin D Supplementation ◽  
Control Group ◽  
Before And After ◽  
Grade 3

Abstract Background and Aims 25(OH)D3 levels are known to be lower in patients with chronic renal disease (CRD). Vitamin D supplementation has been shown to have beneficial effects on mortality in these patients. In our study, we have evaluated the pleiotropic effect of vitamin D on thrombocyte markers, which is known very little by most. Method The main thrombocyte function markers (MPV, PDW and PCT) were obtained in patients which underwent dialysis, renal transplantation and patients with grade 3-4 CRD before and after vitamin D supplementation. 40 healthy individuals were chosen as control group and 24 patients underwent renal transplantation, 25 patients underwent dialysis for at least 3 months, 32 patients were diagnosed as Grade 3-4 CRD. All of the patients above had 25(OH)D3 levels <20ng/mL (<50nmol/L). Thrombocyte markers were evaluated before and after vitamin D supplementation (which was given 50.000 IU orally once a week for 8 weeks). Results Statistically no significant difference were found between MPV values in- and across- group comparison before and after vitamin D supplementation. After the correlation analyses were reviewed, statistically significant negative correlation was found (r=-0,422 p<0.05) between ΔMPV and ΔVitamin D in renal transplantation group. Also statistically significant positive correlation was found between ΔPDW and ΔVitamin D. In the control group with healty participants, a statistically significant negative correlation was found (r=-0,493 p<0.05) between ΔVitamin D and ΔThrombocyte count. In the dialysis group a statistically significant negative correlation was found (r=-0,422 p<0.05) between ΔVitamin D and ΔMPV. Conclusion A significant correlation was found particularly between Vitamin D and MPV in dialysis and renal transplantation patients. In order to prevent cardiovascular events due to thrombosis caused by Vitamin D deficiency which increases MPV, it has been thought that Vitamin D supplementation and antiaggregant therapy might be beneficial.

Large scale importance of sea ice biology in the Southern Ocean

2004 ◽  
Vol 16 (4) ◽  
pp. 471-486 ◽  
Author(s):  
KEVIN R. ARRIGO ◽  
DAVID N. THOMAS
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Primary Production ◽  
Large Scale ◽  
Life Forms ◽  
Ice Algae ◽  
Visible Radiation ◽  
Sea Ice Algae ◽  
Physiological Adaptations ◽  
Annual Primary Production

Despite being one of the largest biomes on earth, sea ice ecosystems have only received intensive study over the past 30 years. Sea ice is a unique habitat for assemblages of bacteria, algae, protists, and invertebrates that grow within a matrix dominated by strong gradients in temperature, salinity, nutrients, and UV and visible radiation. A suite of physiological adaptations allow these organisms to thrive in ice, where their enormous biomass makes them a fundamental component of polar ecosystems. Sea ice algae are an important energy and nutritional source for invertebrates such as juvenile krill, accounting for up to 25% of total annual primary production in ice-covered waters. The ability of ice algae to produce large amounts of UV absorbing compounds such as mycosporine-like amino acids makes them even more important to organisms like krill that can incorporate these sunscreens into their own tissues. Furthermore, the nutrient and light conditions in which sea ice algae thrive induce them to synthesize enhanced concentrations of polyunsaturated fatty acids, a vital constituent of the diet of grazing organisms, especially during winter. Finally, sea ice bacteria and algae have become the focus of biotechnology, and are being considered as proxies of possible life forms on ice-covered extraterrestrial systems. An analysis of how the balance between sea ice and pelagic production might change under a warming scenario indicates that when current levels of primary production and changes in the areas of sea ice habitats are taken into account, the expected 25% loss of sea ice over the next century would increase primary production in the Southern Ocean by approximately 10%, resulting in a slight negative feedback on climate warming.

scholarly journals Aboveground Net Primary Production of tree cover at the post-disturbance area in the Tatra National Park, Slovakia

2015 ◽  
Vol 61 (3) ◽  
pp. 167-174
Author(s):  
Bohdan Konôpka ◽  
Jozef Pajtík ◽  
Vladimír Šebeň ◽  
Michal Bošeľa
Keyword(s):  
Primary Production ◽  
National Park ◽  
Large Scale ◽  
Net Primary Production ◽  
Standing Stock ◽  
Tree Cover ◽  
Negative Consequences ◽  
Aboveground Net Primary Production ◽  
Allometric Relations ◽  
Tatra National Park

Abstract Large-scale disturbances under the conditions of Slovakia, caused especially by storm and bark beetle, bring dramatic decline in carbon budget of the country, besides other negative consequences. The largest disturbance in modern history of the Slovak forestry was the storm damage that occurred in November 2004. The Tatra National Park (TNP) was one of the most affected regions. Thus, in this territory, two transects (T1 – the Danielov dom site and T2 – near the Horný Smokovec village) were established to survey basic dendrometric properties of trees in young stands established after the disaster. The standing stock of aboveground biomass in tree cover for the spring and autumn 2014 was calculated using the recorded variables, i.e. tree height and diameter measured at the stem base, together with the region-specific allometric relations. Then, the Aboveground Net Primary Production (ANPP) in tree cover was estimated with respect to its components (stem, branches and foliage). ANPP was 315 g m−2 per year (Transect T1), and 391 g m−2 per year (Transect T2). The differences in the structure of ANPP, i.e. contribution of tree components, were found between transects T1 and T2. They were caused by the contrasting tree species composition, specifically the ratios between Norway spruce and broadleaved species. Broadleaves allocated more biomass production to foliage than spruce. This phenomenon together with higher turnover (once a year) of foliage caused that broadleaves manifest higher share of fast-cycling carbon in comparison to the amount of carbon sequestrated in woody parts (stem and branches). High variability of ANPP was found within the transects, i.e. among the plots (microsites). As for the representative estimation of the standing stock of aboveground part of tree cover as well as ANPP at the post-disturbance area in the TNP territory, the survey should be performed on a net of research plots. Only this approach enables reliable estimates of carbon amount sequestrated in woody parts, eventually carbon yearly absorbed by young forest stands.

Does septoplasty change the dimensions of compensatory hypertrophy of the middle turbinate?

2016 ◽  
Vol 130 (6) ◽  
pp. 554-559 ◽  
Author(s):  
D Demir ◽  
K Asil ◽  
M Güven ◽  
Ü Erkorkmaz
Keyword(s):  
Negative Correlation ◽  
Middle Turbinate ◽  
Significant Negative Correlation ◽  
Compensatory Hypertrophy ◽  
Paired Sample ◽  
Nasal Septal Deviation ◽  
Wilcoxon Rank Sum Test ◽  
Before And After ◽  
One Year ◽  
Radiological Analysis

AbstractObjective:To measure the dimensions of compensatory hypertrophy of the middle turbinate in patients with nasal septal deviation, before and after septoplasty.Methods:The mucosal and bony structures of the middle turbinate and the angle of the septum were measured using radiological analysis before septoplasty and at least one year after septoplasty. All pre- and post-operative measurements of the middle turbinate were compared using the paired samplet-test and Wilcoxon rank sum test.Results:The dimensions of bony and mucosal components of the middle turbinate on concave and convex sides of the septum were not significantly changed by septoplasty. There was a significant negative correlation after septoplasty between the angle of the septum and the middle turbinate total area on the deviated side (p= 0.033).Conclusion:The present study findings suggest that compensatory hypertrophy of the middle turbinate is not affected by septoplasty, even after one year.

Dry air-induced constriction: effects of pharmacological intervention and temperature

1987 ◽  
Vol 62 (5) ◽  
pp. 1794-1800 ◽  
Author(s):  
A. N. Freed ◽  
D. Wang ◽  
H. A. Menkes
Keyword(s):  
Negative Correlation ◽  
Physiological Response ◽  
Significant Negative Correlation ◽  
Pharmacological Intervention ◽  
Airway Wall ◽  
Moist Air ◽  
Dry Air ◽  
Peripheral Lung ◽  
Before And After ◽  
Lung Periphery

We studied airway wall temperature (Taw) during dry air challenge of the canine lung periphery. We measured collateral resistance (Rcs) before and after periods of elevated airflow using a wedged bronchoscope technique. As flow rate increased, Taw dropped and postchallenge Rcs rose. A significant negative correlation was found between Taw recorded during challenge and Rcs observed 5 min after challenge. Repetitive dry air challenge produced similar changes in Rcs and Taw. However, responses to warm moist air were significantly lower than consecutive responses to dry air. Taw was significantly lower during dry air challenge than during moist air challenge. Indomethacin (5 mg/kg) and atropine (1 mg/kg) reduced responses to dry airflow challenge. Indomethacin did not affect Taw during the challenge, whereas atropine reduced the fall in Taw. We conclude that temperature correlates negatively with peripheral lung tone 5 min after dry air challenge. This correlation holds under conditions where airflow is increased, air is humidified, or atropine is administered. The dissociation between Taw and physiological response after indomethacin likely reflects a decrease in mediators released during challenge.

scholarly journals Primary Production and Fish Yield Estimation in the Meghna River System, Bangladesh

2005 ◽  
Vol 18 (2) ◽  
Author(s):  
K.K.U. AHMED ◽  
S.U. AHMED ◽  
G.C. HALDAR ◽  
M.R.A. HOSSAIN ◽  
T. AHMED
Keyword(s):  
Primary Production ◽  
Water Temperature ◽  
Negative Correlation ◽  
Net Primary Production ◽  
Gross Primary Production ◽  
Euphotic Zone ◽  
River System ◽  
Significant Negative Correlation ◽  
Fish Yield ◽  
The Mean

This study was carried out in four selected stations (Mohonpur, Kaligonj, Charludua and Daulatkhan) in the Meghna river system, Bangladesh between the latitude 22°35.494Ñ N - 23°23.987 N and longitude 90°35.793 E - 90°49.061Ñ E. Average net primary production (NPP) and gross primary production (GPP) (gC·m3 ·h) in the euphotic zone of the Meghna river were 0.089 ± 0.021 and 0.161 ± 0.025 respectively. The rate of conversion of GPP into NPP ranged between 48.17 and 62.63% with an average of 54.72%. The mean ratio of NPP to GPP (NPP:GPP), NPP:Respiration and average percent respiration rate to GPP were 0.549 ± 0.060, 1.251 ± 0.320 and 45.04 ± 6.02% respectively. The mean photosynthetic production for the day (gC·m3 ·day) and year (gC·m3 ·yr) were 1.930 and 704.45 respectively. Annual computed fish yield in relation to gross carbon synthesis was 7.0 kg fish·m3 ·year. The actual production of fish from the Meghna river is accounted about 0.21% of the estimated production. The gross energy production (Kcal energy·m3 ·day) by the producers was estimated about 18.0. The NPP of phytoplankton established a high significant negative correlation (r = -0.975; p < 0.01) with water temperature and low, but a definite negative correlation existed (r = -0.767) between GPP and water temperature.

Thrombin generation in paediatric patients with congenital heart disease

2008 ◽  
Vol 28 (S 01) ◽  
pp. S61-S66 ◽  
Author(s):  
G. Cvirn ◽  
A. Rosenkranz ◽  
B. Leschnik ◽  
W. Raith ◽  
W. Muntean ◽  
...  
Keyword(s):  
Congenital Heart Disease ◽  
Heart Disease ◽  
Negative Correlation ◽  
Congenital Heart ◽  
Thrombin Generation ◽  
Significant Negative Correlation ◽  
Peak Height ◽  
Global Test ◽  
Paediatric Patients ◽  
Age Range

SummaryThrombin generation was studied in paediatric patients with congenital heart disease (CHD) undergoing cardiac surgery using the calibrated automated thrombography (CAT) in terms of the lag time until the onset of thrombin formation, time to thrombin peak maximum (TTP), endogenous thrombin potential (ETP), and thrombin peak height. The suitability to determine the coagulation status of these patients was investigated. Patients, material, methods: CAT data of 40 patients with CHD (age range from newborn to 18 years) were compared to data using standard coagulation parameters such as prothrombin (FII), antithrombin (AT), tissue factor pathway inhibitor (TFPI), prothrombin fragment 1.2 (F 1.2), thrombin-antithrombin (TAT), activated partial thromboplastin time (aPTT), and prothrombin time (PT). Results: A significant positive correlation was seen between ETP and FII (p < 0.01; r = 0.369), as well as between peak height and F II (p < 0.01; r = 0.483). A significant negative correlation was seen between ETP and TFPI values (p < 0.05; r = –0.225) while no significant correlation was seen between peak height and TFPI. A significant negative correlation was seen between F 1.2 generation and ETP (p < 0.05; r = –0.254) and between F 1.2 generation and peak height (p < 0.05; r = –0.236). No correlation was seen between AT and ETP or peak. Conclusions: CAT is a good global test reflecting procoagulatory and inhibitory factors of the haemostatic system in paediatric patients with CHD.

The Effect of Active Site-inhibited Factor VIIa on Tissue Factor-initiated Coagulation Using Platelets before and after Aspirin Administration

1997 ◽  
Vol 78 (04) ◽  
pp. 1202-1208 ◽  
Author(s):  
Marianne Kjalke ◽  
Julie A Oliver ◽  
Dougald M Monroe ◽  
Maureane Hoffman ◽  
Mirella Ezban ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Active Site ◽  
Large Scale ◽  
Thrombin Generation ◽  
Factor Viia ◽  
Dependent Manner ◽  
Antithrombotic Agent ◽  
Before And After ◽  
Ic50 Values

SummaryActive site-inactivated factor VIIa has potential as an antithrombotic agent. The effects of D-Phe-L-Phe-L-Arg-chloromethyl ketone-treated factor VIla (FFR-FVIIa) were evaluated in a cell-based system mimicking in vivo initiation of coagulation. FFR-FVIIa inhibited platelet activation (as measured by expression of P-selectin) and subsequent large-scale thrombin generation in a dose-dependent manner with IC50 values of 1.4 ± 0.8 nM (n = 8) and 0.9 ± 0.7 nM (n = 7), respectively. Kd for factor VIIa binding to monocytes ki for FFR-FVIIa competing with factor VIIa were similar (11.4 ± 0.8 pM and 10.6 ± 1.1 pM, respectively), showing that FFR-FVIIa binds to tissue factor in the tenase complex with the same affinity as factor VIIa. Using platelets from volunteers before and after ingestion of aspirin (1.3 g), there were no significant differences in the IC50 values of FFR-FVIIa [after aspirin ingestion, the IC50 values were 1.7 ± 0.9 nM (n = 8) for P-selectin expression, p = 0.37, and 1.4 ± 1.3 nM (n = 7) for thrombin generation, p = 0.38]. This shows that aspirin treatment of platelets does not influence the inhibition of tissue factor-initiated coagulation by FFR-FVIIa, probably because thrombin activation of platelets is not entirely dependent upon expression of thromboxane A2.

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