• Title/Summary/Keyword: egg exposure

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Ionic currents elicited by the hypotonic solution in hamster eggs (저장성 용액에 노출된 햄스터 난자에 관찰되는 이온전류의 변화)

  • Choi, Won-yeong;Kim, Yang-mi;Haan, Jae-hee;Huh, Il-oh;Park, Choon-ok;Hong, Seong-geun;Pyu, Pan-dong;Kim, Jong-shu
    • Korean Journal of Veterinary Research
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    • v.36 no.2
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    • pp.305-312
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    • 1996
  • Cell volume regulatory mechanisms are usually disclosed by exposure of cell to anisotonic media. If a cell is suddenly exposed to hypotonic media, it swells initially like an osmometer but within minutes regains its original cell volume. This behavior has been labelled as regulatory cell volume decrease(RVD). RVD is believed to result from the loss of permeable ions through the membrane. In this study, we examined hypotonically induced changes in the membrance currents involved in RVD by using whole cell voltage clamp technique in the unfertilized hamster egg. At -40mV of the holding potential, the stationary current was maintained in the hamster egg exposed to isotonic solution composed of, mainly, 115mM NaCl and 40mM mannitol. Hypotonic solution was prepared by removing mannitol. Therefore, the concentrations of $Na^+$ and $Cl^-$ in this hypotonic media were the same as those in the isotonic solution. Following 30 to 60 sec after applying the hypotonic media to the egg, the inward current was evoked. This inward current was eliminated by $100{\mu}M$ 4-acetamido-4'-isothiocyanostil-bene-2,2'-disulfonic acid(SITS), an anion channel blocker, leaving the small outward current component. Further addition of 2mM $Ba^{2+}$, a broad $K^+$ channel blocker, completely abolished the small outward current left even in the presence of SITS during hypotonic stress. These results suggest that $K^+$ and $Cl^-$ move out of cells, resulting in RVD. To test the involvement of $Na^+$ in RVD, 20mM Na-isethionate was substituted for mannitol in isotonic media(135mM $Na^+$) and Na-isethionate (20mM) was freed the hypotonic solution. Only $Cl^-$ concentration in both isotonic and hypotonic media was kept constant at 115mM, whereas concentration of $Na^+$ was lowered in hypotonic solution to 115mM from 135mM in isotonic solution. Hypotonic medium induced the outward current in the egg equilibrated isotonically. This current was reduced by $100{\mu}M$ SITS but was augmented by 2 mM $Ba^{2+}$. In terms of RVD, these results imply that $Cl^-$ efflux is coupled with $K^+$, maybe for electroneutrality during hypotonic stress and/or with $Na^+$ via unknown transport mechanism(s). From the overall results, the hypotonic stress facilitates the movement of $Cl^-$ and $K^+$ out of the hamster egg to regain cellular volume with electroneutrality. If there exist a difference in $[Na^+]_0$ between isotonic and hypotonic solution, another transport mechanism concerned with $Na^+$ may, at least partly, participate in regulatory volume decrease.

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Comparative Efficacy of Antifungal Agents for Aquaculture Fish and their Eggs (양식 어류와 이들 난에 대한 항곰팡이성 약물들의 효과 비교)

  • Lee, Bo-Young;Lee, Deok-Chan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.1
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    • pp.34-40
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    • 2009
  • In fresh water fish hatcheries and farms, Saprolegniales often cause serious mortality to the fish and their eggs. Malachite green is an effective antifungal agent, but is carcinogenic to fish and humans. Alternative antifungal agents are needed. Presently, we tested various concentrations of MBT-01108 (Opuntia ficus-indica extracts) alone and in combination with bronopol, formalin and sodium chloride (MBT-01108 mixture) on in vitro mycelial growth and in vivo remediation of adult eel, Anguilla japonica, infected with Saprolegnia sp. and fertilized eggs of chum salmon, Oncorhynchus keta, to evaluate the compounds' antifungal efficacy on eyed-egg and hatching rates. MBT-Oll08 mixtures incorporating bronopol and formalin at respective concentrations of 50 and 30 parts per million (ppm), and 100 and 20 ppm were most effective in controlling Saprolegnia in vitro and in vivo (P<0.05). Repeated daily exposures to 50 ppm and 100 ppm MBT-01108 were more effective than exposure every 2-3 days post-fertilization for the inhibition of Saprolegnia infection of rainbow trout, Oncorhynchus mykiss eggs as compared with control (0 ppm).

Efficacy of Different Seed Kernels against Root Knot Nematode Meloidogyne incognita in Mulberry

  • Chowdary, N.B.;Mukherjee, Sanchayita
    • International Journal of Industrial Entomology and Biomaterials
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    • v.6 no.2
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    • pp.133-138
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    • 2003
  • Five seed kernel namely, Neem (Azadirachta indica A. Juss.), Pongamia (Pongamia glabra L. Pierre), Tamarind (Tamarindus indica L.), Mahua (Madhuca indica Gmel.) and Shikakai (Acacia cancinna De.) were tested against hatching of eggs and larval mortality of Meloidogyne incognita causing root knot disease in mulberry along with Furadan (Carbofuran) and Bionema (a bioformulation developed from Verticillium chlamydosporium) for comparison. Results revealed that highest hush-up of hatching was observed in Neem (77.40%) and Pongamia (75.99%) seed kernel extracts at 100% concentration over the check. Similarly, highest larval mortality was observed in Neem and Pongamia by 76.00% and 74.50%, respectively at 100% concentration after 72 hrs of exposure period. Pot culture studies revealed that pre-application of seed kernel powders (20 days before inoculation of nematode) found to be more effective in controlling the root knot disease than post application. In pre application of seed kernel powders, maximum reduction of root knots was observed in case of Neem seed kernel powder (54.85%) followed by Pongamia (51.9%). Similar trend was also observed in reduction of egg masses/plant and nematode population /250 cc soil. Rest of the seed kernel extracts was found to be less effective in suppression of hatching, enhancing the larval mortality and controlling the root knot disease. However, application of Furadan and Bionema tested for the comparison were found to be more effective than seed kernel powders. The generated information seems to be useful in developing an ecofriendly integrated approach for the control of root knot nematode disease in mulberry.

Design of EEG Signal Security Scheme based on Privacy-Preserving BCI for a Cloud Environment (클라우드 환경을 위한 Privacy-Preserving BCI 기반의 뇌파신호 보안기법 설계)

  • Cho, Kwon;Lee, Donghyeok;Park, Namje
    • Journal of KIISE
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    • v.45 no.1
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    • pp.45-52
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    • 2018
  • With the advent of BCI technology in recent years, various BCI products have been released. BCI technology enables brain information to be transmitted directly to a computer, and it will bring a lot of convenience to life. However, there is a problem with information protection. In particular, EEG data can raise issues about personal privacy. Collecting and analyzing big data on EEG reports raises serious concerns about personal information exposure. In this paper, we propose a secure privacy-preserving BCI model in a big data environment. The proposed model could prevent personal identification and protect EEG data in the cloud environment.

A Preliminary Study for Development of a Bioassay Protocol Using the Sperm of a Starfish, Asterias amurensis

  • Ryu, Tae-Kwon;Lee, Chang-Hoon;Park, Jin-Woo
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • 2003.10a
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    • pp.158-158
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    • 2003
  • Bioassays using gametes of sea urchins are widely used in ecotoxicological assessments of marine environments. Since most of sea urchin species in Korean coastal water spawn from spring to autumn, bioassay with them during the winter is impossible. In the course of developing standard methods for bioassays with Korean species, we found a winter-spawning starfish, Asterias amurensis, Since reproductive mode of asteroids is similar to echinoids, the bioassay protocol for sea urchins could be applied similarly to the starfish. Here, we tested and determined several conditions for the acceptability of bioassay with A. amurensis. The least required time for formation of fertilization membrane of fertilized eggs to be easily distinguished from unfertilized ones was 60 min. The threshold of sperm to egg ratio that could make acceptable fertilization rates in controls was 3000. The allowed time for manipulation of sperm after dilution in seawater was at most 3 hr. The optimal exposure time of sperms when the response against toxicant solution was relatively stable was in the range of 20-60 min. The tolerance range of sperms to the salinity of test solution was 26-38 psu. The sensitivity of A. amurensis sperm was intermediate among marine organisms commonly used in aquatic toxicity tests. The sperm bioassay with A. amurensis can be satisfactorily applied to toxicity assessments of marine environments.

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Inactivation of Salmonella on Eggshells by Chlorine Dioxide Gas

  • Kim, Hyobi;Yum, Bora;Yoon, Sung-Sik;Song, Kyoung-Ju;Kim, Jong-Rak;Myeong, Donghoon;Chang, Byungjoon;Choe, Nong-Hoon
    • Food Science of Animal Resources
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    • v.36 no.1
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    • pp.100-108
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    • 2016
  • Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella. ClO2 gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO2 each at 20 ppm, 40 ppm, and 80 ppm against S. Enteritidis; 40 ppm and 80 ppm against S. Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella, the most prevalent contaminant in the egg industry.

Discoloration of Lead Containing Pigments in Paintings(II) (회화에 사용되는 납 화합물 안료의 변색(II))

  • Hwang, In-sook
    • 한국문화재보존과학회:학술대회논문집
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    • 2004.10a
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    • pp.72-74
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    • 2004
  • The color change of lead-containing pigments is one of the most serious diseases in watercolor, oil paintings and wall paintings. These pigments have a tendency to darken or brighten. It was proved that oxidation of lead containing pigments in the formation of brown-colored lead dioxide is a photochemical reaction under high humidity conditions. Therefore, we carried out some analogic experiments on the color change of three typical lead containing pigments ; $Pb_3O_4$, Pbo and $PbCo_3{\cdot}Pb(OH)_2$ at the conditions of illuminations under the high humidity ($2PbCo_3{\cdot}Pb(OH)_2$ R. H.). The reason for the chemical reactions are discussed and the results of these experiments are shown in some spectrograms, micrographs and X-ray micro-diffraction patterns. Important conclusions were drawn in our research. Due to the formation of brown $PbO_2$, red lead $(Pb_3O_4)$ and massicot (PbO) turned brown or dark when they were illuminated light under high humidity. We noticed that the brightening of red lead occurred d to admixture with chalk or lead white in egg yolk or linseed oil medium on exposure to light. Lead white used in oil paintings turned yellowish on dark.

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The Mentum Deformity of C. plumosus Following Exposure to Endocrine Disruption Chemicals (내분비교란 물질에 노출된 C. plumosus (장수깔따구)의 하순기절 기형성)

  • Lee, Won-Choel;Kwak, Inn-Sil
    • Korean Journal of Ecology and Environment
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    • v.38 no.1 s.110
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    • pp.11-17
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    • 2005
  • Egg masses of C. plumosus were collected from Jungnang Stream in Seoul and reared in an incubator chamber. The larvae of C. plumosus were treated with potential endocrine disruption chemicals (EDCs) such as Diethylhexyl phthalate (DEHP), Bisphenol A (BPA) and Tebufenozide, and the effects of morphological abnormalities were observed. The deformities of the mentum following exposure to EDCs showed the smooth/round tooth, the loss of ${\ge}$1 tooth, reduced median lateral teeth (MLT) and light brown color. The incidence rates of the mentum deformity were associated with chemicals: BPA (73.7 ${\sim}$ 90.9%)>tebufenozide (57.6 ${\sim}$ 78.9%)>DEHP (46.2 ${\sim}$ 85.7%). The deformity type of the mentum showed MIX (MLT+LT, 32 ${\sim}$ 46%)>MLT (25 ${\sim}$ 34%)>LT (lateral teeth, 3 ${\sim}$ 7%). Also, the incidence of MIX type was in the order of BPA (46%)>DEHP (33%) >tebufenozide (32%), and that of MLT type showed DEHP (34%)>tebufenozide (31%)>BPA (25%). As the concentration of Tebufenozide increased, the incidence of light brown mentum was dose dependent. While the incidences of light brown mentum following exposure to BPA and DEHP were not associated with their concentrations.

Environmental Contamination by Echinococcus granulosus sensu lato Eggs in Relation to Slaughterhouses in Urban and Rural Areas in Tunisia

  • Chaabane-Banaoues, Raja;Oudni-M'rad, Myriam;M'rad, Selim;Mezhoud, Habib;Babba, Hamouda
    • Parasites, Hosts and Diseases
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    • v.54 no.1
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    • pp.113-118
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    • 2016
  • Hydatidosis has become a real concern for health care institutions and animal rearers in Tunisia. The Tunisian endemicity is aggravated by the growing number of dogs and the difficulty of getting rid of contaminated viscera because of the lack of equipment in most slaughterhouses. Therefore, microscopic and molecular tools were applied to evaluate the role of slaughterhouses in canine infection and Echinococcus granulosus sensu lato (s. l.) egg dissemination. Exposure risk to E. granulosus s. l. eggs in urban and rural areas was explored in order to implant preventive and adapted control strategies. Microscopic examinations detected taeniid eggs in 152 amongst 553 fecal samples. The copro-PCR demonstrated that 138 of 152 taeniid samples analyzed were positive for E. granulosus s. l. DNA. PCR-RFLP demonstrated that all isolated samples belonged to E. granulosus sensu stricto (s. s.). An important environmental contamination index (25.0%) by E. granulosus s. l. eggs was demonstrated. The average contamination index from the regions around slaughterhouses (23.3%; 95% CI: 17.7-28.9%) was in the same range as detected in areas located far from slaughterhouses (26.0%, 95% CI: 21.3-30.8%). Echinococcosis endemic areas were extended in both rural (29.9%, 95% CI: 24.8-34.9%) and urban locations (18.1%, 95% CI: 13.0-22.9%). The pathogen dissemination is related neither to the presence/absence of slaughterhouses nor to the location in urban or rural areas, but is probably influenced by human activities (home slaughtering) and behavior towards the infected viscera.

Comparison of Larval Fish Survival of Pale chub (Zacco platypus) Exposed to Different Levels Turbidity (탁수조건에 따른 피라미 치자어의 생존률 비교)

  • Moon, Woon-Ki;Bae, Dae-Yul;Jung, Myoung-Sook;Lee, Sang-Don;Kim, Jai-Ku
    • Korean Journal of Ecology and Environment
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    • v.45 no.3
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    • pp.314-321
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    • 2012
  • To quantitatively assess the effects of turbidity on egg development and larval fish survival, a laboratory fish rearing experiment was applied to different life stages (newly hatched larval stage, juvenile stage and pre-adult stage) of the Zacco platypus, one of the most universal and tolerant species in Korea. According to the stress index of turbidity in water with exposure time, three different treatments, including a reference condition (1~7 NTU) as well as intermediate (20~150 NTU) and high turbidity conditions (400~1,000 NTU) were applied, and egg hatching and larval fish mortality rates were observed. The mortality rates of newly hatched larval fish were significantly different among treatments (ANOVA, $F_{2,3}$=17.79, p<0.05). Average rates of survival to hatching were 20.9% (${\pm}0.1%$) for reference condition, 11% (${\pm}6.9%$) for intermediate level and 3.2% (${\pm}3.7%$) for high level conditions, respectively. A sudden change of mortality at the high level was observed within 5 days of the experiment. About 84% of juvenile fish survived until 20 experimental periods under conditions of reference turbidity, while survival under conditions of intermediate turbidity was over 80% of larval fish until day 13 of the experiment, but dropped to less than 10% after day 14 and 15 of two experiments. Fish mortality appeared from day 6 of the high turbidity experiment, and 50% mortality was achieved at day 9 to 10 of experiment. Full mortality occurred at day 14 of the experiment (RM-ANOVA, $F_{2,38}$, p<0.005). In the pre-adult stage experiment, no mortality was observed during the experiment at reference level treatment (20 days), while only slight mortality rates were observed for both intermediate and high levels until day 5 of the experiment, however, no further fish died in either experiment. It was significantly different compared to reference condition (RM-ANOVA, $F_{2,20}$=8.28, p<0.01), but no difference was observed between intermediate and high level conditions. Consequently, this tolerant species has been determined to be well adapted to high levels of turbidity in its adult stage, but more vulnerable throughout earlier life stages.