scholarly journals Effects of Hypoxia on the Distribution of Calanoid Copepod Eggs in the Seabed Sediments of the Eutrophic Masan Bay, Korea

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3116
Author(s):  
Seo Yeol Choi ◽  
Bonggil Hyun ◽  
Pung-Guk Jang ◽  
Kyoungsoon Shin ◽  
Ho Young Soh ◽  
...  
Keyword(s):  
Calanoid Copepod ◽  
Hatching Success ◽  
Low Ph ◽  
Water Interface ◽  
Hypoxic Conditions ◽  
Sulphide Concentration ◽  
Significant Difference ◽  
South Sea ◽  
Copepod Eggs ◽  
Seabed Sediments

In this study, we investigate the distribution of calanoid copepod eggs in the sediments of Masan Bay (South Sea, Korea), in which hypoxic conditions occur every summer. In August (2011), hypoxia was observed at all stations, while normoxia was observed in April (2012). The pH and hydrogen sulphide concentration at the sediment-water interface in the inner bay during August were 7.7 and >20 mol L−1, respectively, and there was no significant difference between the stations in April. The abundance of eggs in the sediment ranged from 0.69 to 1.49 × 106 eggs m−2 in August, and from 0.59 to 1.08 × 106 eggs m−2 in April. Notably, the proportion of abnormal eggs was high (a maximum of 77.1%) in August, and a uniform distribution of normal eggs (>80%) was observed in April. A generation of abnormal eggs hatched with deformed nauplii in Masan Bay during the summer, and a failure to hatch was likely due to the high H2S concentration and low pH caused by hypoxia. In this paper, we discuss the effects of hypoxia and seabed environments on the hatching success of calanoid copepod eggs.

Reproductive Success of Amnicola limosa (Gastropoda) in Low Alkalinity Lakes in South-Central Ontario

1989 ◽  
Vol 46 (5) ◽  
pp. 863-869 ◽  
Author(s):  
Margo A. Shaw ◽  
Gerald L. Mackie
Keyword(s):  
Life Cycle ◽  
Reproductive Success ◽  
Hatching Success ◽  
Low Ph ◽  
Critical Stage ◽  
Percent Survival ◽  
South Central ◽  
Order Of Magnitude ◽  
Magnitude Difference

The reproductive success of the gastropod Amnicola limosa was examined in six lakes ranging in pH from 4.62 to 7.42 to determine which stages in the life cycle were most sensitive to acidification. Although fecundity was significantly greater (p < 0.01) for adults reared at pH 7.42 than at pH 5.89–6.64, a failure to oviposit was documented only at pH 4.62. Hatching success was uniformly high (88–97%) at pH 5.59 to 7.42, while embryos incubated at pH 4.62 suffered complete mortality. The most critical stage in the life cycle is the newly hatched stage. Survival during the 20 d post hatch ranged from 23% at pH 5.59 to 69% at pH 7.42. There was an order of magnitude difference in the cumulative percent survival of recruits in lakes ranging in pH from 5.59 (5.1%) to 7.42 (44.0%). Juveniles raised at low pH (5.59–5.70) were on average 0.20 mm (20%) smaller than those in circumneutral lakes (pH 6.64–7.42). The present low densities of Amnicola limosa in Heney Lake (pH 5.59) can be explained by low recruitment since 1980. Evidence presented suggests that the disappearance of this species from clear low pH lakes (pH < 5.8) is due to reductions in fecundity and hatchling survival.

scholarly journals Effects of water pH on susceptibility of whiteleg shrimp (Litopenaeus vannamei) to acute hepatopancreatic necrosis disease Vibrio parahaemolyticus

2019 ◽  
Vol 02 ◽  
pp. 88-96
Author(s):  
Tuan V. Vo
Keyword(s):  
Litopenaeus Vannamei ◽  
Respiratory Burst ◽  
Vibrio Parahaemolyticus ◽  
Low Ph ◽  
Water Levels ◽  
Cumulative Mortality ◽  
High Ph ◽  
Significant Difference ◽  
Water Ph ◽  
Acute Hepatopancreatic Necrosis Disease

Effect of water pH on susceptibility of whiteleg shrimp Litopenaeus vannamei to acute hepatopancreatic necrosis disease caused by Vibrio parahaemolyticus was carried out in laboratory condition. White leg shrimp (2 - 3 g) were challenged by immersion for 2 h with tryptic soy broth (TSB)-grown Vibrio parahaemolyticus at 10 times lower dose of LD50. The results showed that the cumulative mortality of V. parahaemolyticus-immersed shrimp after 240 h was increased from low to high pH water levels (23.3 ± 5.8% in pH 6.3; 30.0 ± 20.0% in pH 7.3; 86.7 ± 15.3 in pH 9.3, respectively). The cumulative mortality of shrimp that held in pH = 8.3 was the lowest (20.0 ± 0.0%). In another experiment, immune parameters such as total haemocytes count and respiratory burst of Litopenaeus vannamei held at different pH levels were examined at 0, 24, 48, 72 and 96 h. The results indicated that no significant difference of total haemocytes count was observed at different pH water levels (pH 6.3, 7.3, 8.3, 9.3) at 0 - 72 hpc (hour post challenge). At 96 hpc, total haemocytes count at high pH water level (9.3) was increased and significant difference in comparison with the total haemocytes count recorded in low pH water levels (6.3, 7.3, 8.3). Respiratory burst was also not different at different pH water levels at 0 hpc. However, respiratory burst of shrimp that held at low pH water levels (pH 6.3 and 7.3) was rapidly reduced and significant difference in compared with the shrimp that held in high pH water levels (pH 8.3 and 9.3). It was therefore concluded that low and high pH stress decrease the resistance of Litopenaeus vannamei against V. parahaemolyticus and decrease several parameters of the immune response.

scholarly journals Is hatching success of copepod eggs diatom density-dependent?

1996 ◽  
Vol 144 ◽  
pp. 185-193 ◽  
Author(s):  
Y Chaudron ◽  
SA Poulet ◽  
M Laabir ◽  
A Ianora ◽  
A Miralto
Keyword(s):  
Hatching Success ◽  
Density Dependent ◽  
Diatom Density ◽  
Copepod Eggs

scholarly journals PENGARUH PEMBERIAN LARUTAN SARI KURMA (PHOENIX DACTYLIFERA L.) DAN LARUTAN FLUOR TERHADAP KEKERASAN EMAIL GIGI SETELAH DIRENDAM DALAM MINUMAN RINGAN BERKARBONASI

2021 ◽  
Vol 2 (1) ◽  
pp. 56-64
Author(s):  
Mety Dwi Putri Eszy ◽  
Afriwardi Afriwardi ◽  
Susi Susi
Keyword(s):  
Tooth Enamel ◽  
Soft Drink ◽  
Surface Hardness ◽  
Phoenix Dactylifera ◽  
Low Ph ◽  
Phoenix Dactylifera L ◽  
Palm Juice ◽  
Significant Difference ◽  
Initial Hardness ◽  
Experimental Laboratory

Soft drink with low pH (5,5) causes tooth erosion. Erosion may result in a decrease in surface hardness of tooth enamel. This research will be used a solution of palm juice and solution of fluoride to increase the surface hardness of tooth enamel. The purpose of this study was to evaluate effect of using a solution of palm juice 100%, 75%, 50%, 25% and APF 1,23% to the surface hardness of tooth enamel. The methode used in this research is the experimental laboratory and were tested for their hardness using Vicker Hardness Tester.Measurement performed three times, initial hardness, after all specimens was soaked in soft drink for 25 hours and were then applied with 100%, 75%, 50%, 25% solution of palm juice dan APF 1,23%. Data was analyzed by using SPSS with Repeated ANOVA.The result showed that a significant decrease in tooth enamel hardness on immersion in carbonated soft drink (p<0,05) and increased hardness of surface enamel after application with 100% solution of palm juice with a mean increase of microhardness 42,91VHN, 38,46 VHN with 75% solution of palm juice, 35,836 VHN with 50% solution of palm juice,29,41 VHN with 25% solution of palm juice dan 23,94 VHN in APF 1,23%.The result of this study is there is no significant difference enamel hardness after applied with 100%, 75%, 50%, 25% solution of palm juice and APF 1,23%.

scholarly journals Effect of Hyperbaric Oxygen Exposure on Bacterial Toxin Antigen and Collagen Induced Arthritis in Animal Model

2019 ◽  
Vol 21 (3) ◽  
pp. 167-172 ◽  
Author(s):  
Titut Harnanik ◽  
J. Soeroso ◽  
M.G. Suryokusumo ◽  
T. Juliandhy
Keyword(s):  
Animal Model ◽  
Hyperbaric Oxygen ◽  
Therapeutic Potential ◽  
Bacterial Toxin ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Collagen Induced Arthritis ◽  
Hypoxic Conditions ◽  
Interleukin 17A ◽  
Significant Difference

Anti-cyclic citrullinated peptide antibody (ACPA) is a specific autoantibody that binds with citrullineamino acid in rheumatoid arthritis (RA). Interleukin-17a (IL-17a) is one of the cytokines that play an important role in chronic inflammation during the process of autoimmune diseases. Bacterial toxin antigen and collagen induced arthritis (ACIA) is the gold standard of RA animal model. The aim of this study was to see the effect of hyperbaric oxygen (HBO) exposure on ACIA animal models. ACIA model was made by combined antigens (bacterial toxin and collagen). A total of 24 male Balb/Cmice modelled on ACIA were divided into three groups. Eight mice did not receive HBO exposure (control group, indicated as G1), eight mice (indicated as G2) received HBO exposure for 10 days while remaining eight mice (indicated as G3) for five days. G2 mice were exposed to HBO 2.4 ATA oxygen 100% for 90 minutes (30 minutes each with two intervals of five minutes breathing with normal air) for 10 consecutive days while G3 mice were exposed only for five days. The indicators of arthritis i.e. ACPA and IL-17a were measured by enzyme-linked immunosorbent assay (ELISA) technique. A significant decrease in ACPA and IL-17a levels was seen in both HBO exposed groups (G2 and G3) compared to G1 (p<0.05). There was no significant difference in levels of ACPA and IL-17a in G3 mice and G2 mice (p > 0.05). HBO reduced inflammation in ACIA by decreasing ACPA andIL-17a levels through improvement of hypoxic conditions and showed therapeutic potential for the treatment of RA.

scholarly journals The Distribution of Vascular Endothelial Growth Factor (VEGF), Human Beta-Defensin-2 (HBD-2), and Hepatocyte Growth Factor (HGF) in Intra-Abdominal Adhesions in Children under One Year of Age

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Anna Junga ◽  
Māra Pilmane ◽  
Zane Ābola ◽  
Olafs Volrāts
Keyword(s):  
Growth Factor ◽  
Control Group ◽  
Relative Distribution ◽  
Abdominal Adhesions ◽  
Related Factors ◽  
Hypoxic Conditions ◽  
Significant Difference ◽  
Group A ◽  
One Year ◽  
Endothelial Growth Factor

The regulatory role between ischemia related factors and antimicrobial peptides in congenital intra-abdominal adhesions has not yet been defined. The aim of this research was to investigate the appearance and relative distribution of VEGF, HBD-2, and HGF in congenital intra-abdominal adhesions compared with relatively healthy tissue controls. The study group material was obtained from 48 patients who underwent abdominal surgery due to partial or complete bowel obstruction. VEGF, HBD-2, and HGF were detected using immunohistochemistry methods and their relative distribution was evaluated by means of the semiquantitative counting method. The results were analyzed using nonparametric statistic methods. A moderate number of VEGF positive endotheliocytes were detected, but there was no statistically significant difference between the groups. In the experimental group, a moderate to high number of VEGF positive macrophages was observed. In control group tissues, such macrophages were seen in significantly lower number (U = 61.0, p = 0.001). The increase of VEGF positive cells indicates support of angiogenesis due to the hypoxic conditions in case of adhesion disease. The number of HBD-2 marked fibroblasts and macrophages was moderate to high, but only few positive endotheliocytes were observed. Persisting appearance of HBD-2 positive structures might be a result of the inflammatory process. Most specimens showed occasional HGF positive macrophages and fibroblasts and there was no statistically significant difference between the groups. The relatively weak appearance of HGF suggests that the lack of this factor promotes the formation of fibrotic changes in case of intra-abdominal adhesions.

AN AUREOMYCIN-ROSE BENGAL AGAR FOR ENUMERATION OF YEAST AND MOLD IN COTTAGE CHEESE

1969 ◽  
Vol 32 (11) ◽  
pp. 442-445 ◽  
Author(s):  
W. W. Overcast ◽  
David J. Weakley
Keyword(s):  
Bacterial Growth ◽  
Rose Bengal ◽  
Low Ph ◽  
Potato Dextrose Agar ◽  
Cottage Cheese ◽  
Significant Difference ◽  
The Mean ◽  
Mold And Yeast

A peptone dextrose agar containing 20 ppm of aureomycin and 20 ppm of rose bengal was compared to acidified potato dextrose agar for the enumeration of yeast and mold. Mold and yeast isolates, as well as yeast and mold from Cottage cheese, were compared on the two agars. The results of the study showed no statistically significant difference between the mean counts on the agars and tests for bacterial growth of five species were all negative. The aureomycin-rose bengal agar had several advantages over the potato dextrose (PD) agar; spreading mold colonies were eliminated, there was no precipitation of casein to interfere with counting colonies, the possibility of some yeast and mold species not growing because of the low pH of the acidified PD medium was eliminated, and the red background aided in detecting colonies of yeast and mold.

scholarly journals Isolation by sugar flotation has no direct effect on the hatching success of zooplankton resting eggs

2016 ◽  
Author(s):  
Dunja Lukic ◽  
Csaba F. Vad ◽  
Zsófia Horváth
Keyword(s):  
Hatching Success ◽  
Resting Eggs ◽  
Accurate Estimation ◽  
Temporary Waters ◽  
Large Branchiopods ◽  
Triops Cancriformis ◽  
Significant Difference ◽  
Flotation Method ◽  
Active Communities ◽  
Sugar Flotation

<p>Zooplankton in temporary waters produces resting stages to survive recurrent dry periods. Branchiopod crustaceans (i.e., cladocerans, large branchiopods) overcome these periods in the form of resting eggs buried in the sediment. Examining the diversity in the resting egg banks allows for a more accurate estimation of biodiversity of aquatic ecosystems than looking only at the active communities. The isolation of resting eggs from the sediment may be achieved by the sugar flotation method, which usually results in higher density and diversity than untreated samples (i.e., incubated in the sediment). We tested the effect of sugar isolation and centrifugation on the hatching success of resting eggs already isolated from sediment in order to reveal any direct effects on hatching success. We used four different branchiopod species, <em>Daphnia magna</em>, <em>Moina brachiata</em>, <em>Branchinecta orientalis</em>, and <em>Triops cancriformis</em>. Although we hypothesised that osmotic stress caused by sugar and centrifuging influence the hatching success either positively (e.g., faster activation as a response to osmotic changes) or negatively (destroyed by centrifugation), we found no significant difference either in the timing or rate of hatching between centrifuged and non-centrifuged eggs. Once the eggs are exposed to light and/or oxygen availability by being removed from the sediment, the centrifugation process does not have any additional effect on their hatching. Regardless of treatment, we found a significant difference in the hatching timing in the two major groups, with large branchiopods hatching earlier than cladocerans. We found that the sugar flotation method itself does not influence the hatching fraction of branchiopod resting eggs (implying no adverse effect on their viability) and its success in enhancing hatching can be attributed to its efficiency in removing eggs from the sediment.</p>

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