WorldWideScience

Sample records for temperature embryo age

  1. Effects of breeder age, strain, and eggshell temperature on nutrient metabolism of broiler embryos.

    Science.gov (United States)

    Nangsuay, A; Meijerhof, R; van den Anker, I; Heetkamp, M J W; Kemp, B; van den Brand, H

    2017-06-01

    Breeder age and broiler strain influence the availability of nutrients and oxygen through yolk size and eggshell conductance, and the effects of these egg characteristics on nutrient metabolism might be influenced by eggshell temperature (EST). This study aims to determine effects of breeder age, strain, and EST on nutrient metabolism of embryos. A study was designed as a 2 × 2 × 2 factorial arrangement using four batches of in total 4,464 hatching eggs of 2 flock ages at 29 to 30 wk (young) and 54 to 55 wk (old) of Ross 308 and Cobb 500. EST of 37.8 (normal) or 38.9°C (high) was applied from incubation day 7 (E7) until hatching. Wet yolk weight was determined mainly by breeder age (P = 0.043). Energy content in yolk (P = 0.004) and albumen + yolk (P = 0.005) were higher in old flock eggs than in young flock eggs, but did not differ between broiler strains. Eggshell conductance was higher in Ross 308 eggs than in Cobb 500 eggs (P availability of oxygen could have contributed to these differences. © 2016 Poultry Science Association Inc.

  2. Effects of breeder age, broiler strain, and eggshell temperature on development and physiological status of embryos and hatchlings.

    Science.gov (United States)

    Nangsuay, A; Meijerhof, R; van den Anker, I; Heetkamp, M J W; Morita, V De Souza; Kemp, B; van den Brand, H

    2016-07-01

    Breeder age and broiler strain can influence the availability of nutrients and oxygen, particularly through differences in yolk size and shell conductance. We hypothesized that these egg characteristics might affect embryonic responses to changes in eggshell temperature (EST). This study aimed to investigate the effect of breeder age, broiler strain, and EST on development and physiological status of embryos. A study was designed as a 2 × 2 × 2 factorial arrangement using 4 batches of 1,116 hatching eggs of 2 flock ages at 29 to 30 wk (young) and 54 to 55 wk (old) of Ross 308 and Cobb 500. EST of 37.8 (normal) or 38.9°C (high) was applied from incubation d 7 (E7) until hatching. The results showed that breeder age rather than broiler strain had an influence on yolk size (P = 0.043). The shell conductance was higher in Ross 308 than in Cobb 500 (P Cobb 500 eggs yielded embryos with a lower YFBM at E14, E18, and 3 h after hatch (all P < 0.05) than Ross 308 eggs. Breeder age had no effect on YFBM, but the RSY weight was higher in embryos from the old flock compared to the young flock embryos at E14 and E16 (both P < 0.05). A 3-way interaction among breeder age, strain, and EST was found, especially for incubation duration, navel quality, and relative heart and stomach weights at 3 h after hatch (all P < 0.05). Based on the results obtained, we conclude that oxygen availability rather than nutrient availability determines embryonic development, and the egg characteristics affected embryonic responses to changes of EST, especially for variables related to chick quality. © 2016 Poultry Science Association Inc.

  3. Effects of breeder age, strain, and eggshell temperature on nutrient metabolism of broiler embryos

    NARCIS (Netherlands)

    Nangsuay, A.; Meijerhof, R.; Anker-Hensen, van den I.; Heetkamp, M.J.W.; Kemp, B.; Brand, van den H.

    2017-01-01

    Breeder age and broiler strain influence the availability of nutrients and oxygen through yolk size and eggshell conductance, and the effects of these egg characteristics on nutrient metabolism might be influenced by eggshell temperature (EST). This study aims to determine effects of breeder age,

  4. Effects of breeder age, broiler strain, and eggshell temperature on development and physiological status of embryos and hatchlings

    NARCIS (Netherlands)

    Nangsuay, A.; Meijerhof, R.; Anker-Hensen, van den Ilona; Heetkamp, M.J.W.; Souza Morita, De V.; Kemp, B.; Brand, Van Den H.

    2016-01-01

    Breeder age and broiler strain can influence the availability of nutrients and oxygen, particularly through differences in yolk size and shell conductance. We hypothesized that these egg characteristics might affect embryonic responses to changes in eggshell temperature (EST). This study aimed to

  5. High incubation temperatures enhance mitochondrial energy metabolism in reptile embryos.

    Science.gov (United States)

    Sun, Bao-Jun; Li, Teng; Gao, Jing; Ma, Liang; Du, Wei-Guo

    2015-03-09

    Developmental rate increases exponentially with increasing temperature in ectothermic animals, but the biochemical basis underlying this thermal dependence is largely unexplored. We measured mitochondrial respiration and metabolic enzyme activities of turtle embryos (Pelodiscus sinensis) incubated at different temperatures to identify the metabolic basis of the rapid development occurring at high temperatures in reptile embryos. Developmental rate increased with increasing incubation temperatures in the embryos of P. sinensis. Correspondingly, in addition to the thermal dependence of mitochondrial respiration and metabolic enzyme activities, high-temperature incubation further enhanced mitochondrial respiration and COX activities in the embryos. This suggests that embryos may adjust mitochondrial respiration and metabolic enzyme activities in response to developmental temperature to achieve high developmental rates at high temperatures. Our study highlights the importance of biochemical investigations in understanding the proximate mechanisms by which temperature affects embryonic development.

  6. The role of growth regulators, embryo age and genotypes on ...

    African Journals Online (AJOL)

    One of the most important problem of tomato breeders is lengthy seed to seed cycle in a breeding program. In vitro techiques provide a lot of advantages for breeders. The objective of this work was to determine the effect of growth regulators and immature embryo age on embryo germination and rapid generation ...

  7. The role of growth regulators, embryo age and genotypes on ...

    African Journals Online (AJOL)

    Administrator

    2011-06-06

    Jun 6, 2011 ... Key words: Growth regulators, immature embryo culture, embryo age, tomato, kinetin, IAA, shortened breeding cycle. INTRODUCTION. Tomato is ... toes suffer from many biotic and abiotic stress factors which also limit tomato production. ... and washed twice with sterile distilled water. Sterilized fruits were.

  8. Temperature and photoperiod responses of soybean embryos cultured in vitro

    Science.gov (United States)

    Raper, C. D. Jr; Patterson, R. P.; Raper CD, J. r. (Principal Investigator)

    1986-01-01

    Temperature and photoperiod each have direct effects on growth rate of excised embryos of soybean (Glycine max (L.) Merrill). To determine if the effects of photoperiod are altered by temperature, embryos of 'Ransom II' were cultured in vitro at 18, 24, and 30 degrees C under photoperiod durations of 12 and 18 h at an irradiance of 9 W m-2 (700 to 850 nm) and a photosynthetic photon flux density of 58 micromoles m-2 s-1 (400 to 700 nm). Accumulation rates of fresh and dry weight were greater under 18-h than 12-h photoperiods over the entire range of temperature. Water content of the culture embryos was not affected by photoperiod but was greater at 18 and 30 than 24 degrees C. The accumulation rate of dry weight increased from 18 to 26 but declined at 30 degrees C.

  9. Effects of elevated ambient temperature on embryo implantation in rats

    African Journals Online (AJOL)

    Yomi

    2012-03-22

    Mar 22, 2012 ... Effects of elevated ambient temperature on embryo implantation in rats. Huda Yahia Hamid1,2, Md Zuki Abu Bakar Zakaria2*, Nurhusien Yimer3, Goh Yong Meng2, Abd. Wahid Haron4 and Noordin Mohamed Mustapha5. 1Department of Anatomy, Faculty of Veterinary Medicine, University of Khartoum, ...

  10. Effect of women's age on embryo morphology, cleavage rate and competence-A multicenter cohort study

    DEFF Research Database (Denmark)

    Grøndahl, Marie Louise; Christiansen, Sofie Lindgren; Kesmodel, Ulrik Schiøler

    2017-01-01

    .0001) with increasing age. Maternal age had no effect on cleavage parameters or on the morphology of the embryo day 2 post insemination. Interestingly, initial hCG value after single embryo transfer followed by ongoing pregnancy was increased with age in both IVF (p = 0.007) and ICSI (p = 0.001) cycles. For the first...... time, we show that a woman's age does impose a significant footprint on early embryo morphological development (3PN). In addition, the developmentally competent embryos were associated with increased initial hCG values as the age of the women increased. Further studies are needed to elucidate......This multicenter cohort study on embryo assessment and outcome data from 11,744 IVF/ICSI cycles with 104,830 oocytes and 42,074 embryos, presents the effect of women's age on oocyte, zygote, embryo morphology and cleavage parameters, as well as cycle outcome measures corrected for confounding...

  11. [Influence of patient age and the number of good-quality-embryos transferred on multiple gestation in in vitro fertilization and embryo transfer].

    Science.gov (United States)

    Zhang, Shun-Ji; Gong, Fei; Lin, Ge; Lu, Chang-Fu; Xiao, Hong-Mei; Lu, Guang-Xiu

    2008-08-01

    To observe the influence of patient's age, and the number of transferred-good-quality-embryos on multiple gestation rates in in vitro fertilization and embryo transfer (IVF-ET) cycles. In this retrospective study, a total of 4,395 patients who transferred fresh embryo between Jan 2004 and Nov 2006 was analyzed. According to the age, the patients were divided into 2 groups: aged or= 35 (953 cycles). We regularly transferred 2 - 3 embryos. If the patients had only one embryo, one was transferred. And those patients who had only 2 embryos, even if they were more than 35 years old or it would be the second time for them to transfer, were transferred 2 embryos. The influence of female age and the number of good quality embryos transferred on the multiple gestation rates in IVF-ET cycle was analyzed. (1) The multiple gestation rate of the groups of 1 good quality embryo, 2 good quality embryos, or 3 good quality embryos transferred were 21.08% (35/166), 31.41% (413/1315), and 42.37% (75/177), respectively in women aged good quality embryos transferred group and 3 good quality embryos transferred group. (2) The multiple gestation rates of the groups of 1 good quality embryo, 2 good quality embryos, or 3 good quality embryos transferred were 19.51% (8/41), 20.65% (19/92), and 40.66% (74/182), respectively, in women aged >or= 35; there were no significant differences between 1 good quality embryo transferred group and 2 good quality embryos transferred group. The pregnancy rates of these groups were 19.07% (41/215), 33.70% (92/273), and 39.14% (182/465), respectively; there were no significant differences between 2 good quality embryos transferred group and 3 good quality embryos transferred group. (3) The pregnancy rate of the patients aged or= 35 [33.05% (315/953)]. The transfer of 2 good quality embryos results in similar pregnancy rates and significantly reduced multiple gestation rates when compared to the transfer of 3 good quality embryos in women regardless of their

  12. Effect of women's age on embryo morphology, cleavage rate and competence-A multicenter cohort study

    DEFF Research Database (Denmark)

    Grøndahl, Marie Louise; Christiansen, Sofie Lindgren; Kesmodel, Ulrik Schiøler

    2017-01-01

    .0001) with increasing age. Maternal age had no effect on cleavage parameters or on the morphology of the embryo day 2 post insemination. Interestingly, initial hCG value after single embryo transfer followed by ongoing pregnancy was increased with age in both IVF (p = 0.007) and ICSI (p = 0.001) cycles. For the first...... time, we show that a woman's age does impose a significant footprint on early embryo morphological development (3PN). In addition, the developmentally competent embryos were associated with increased initial hCG values as the age of the women increased. Further studies are needed to elucidate......, if this increase in initial hCG value with advancing maternal age is connected to the embryo or the uterus....

  13. The effect of embryo donor age and parity on the superovulatory ...

    African Journals Online (AJOL)

    This study was conducted to evaluate the effect of the age and parity of the embryo donor on the superovulatory response and embryo recovery rate in Boer goat does. The oestrous cycles of seven maiden does (young, 1 - 2 years) and nine multiparous does (adult, 3 - 4 years) were synchronised using controlled internal ...

  14. Effects of temperature on gene expression in embryos of the coral Montastraea faveolata.

    KAUST Repository

    Voolstra, Christian R.

    2009-12-23

    Coral reefs are expected to be severely impacted by rising seawater temperatures associated with climate change. This study used cDNA microarrays to investigate transcriptional effects of thermal stress in embryos of the coral Montastraea faveolata. Embryos were exposed to 27.5 degrees C, 29.0 degrees C, and 31.5 degrees C directly after fertilization. Differences in gene expression were measured after 12 and 48 hours.

  15. Effects of temperature on gene expression in embryos of the coral Montastraea faveolata

    Directory of Open Access Journals (Sweden)

    Randall Carly J

    2009-12-01

    Full Text Available Abstract Background Coral reefs are expected to be severely impacted by rising seawater temperatures associated with climate change. This study used cDNA microarrays to investigate transcriptional effects of thermal stress in embryos of the coral Montastraea faveolata. Embryos were exposed to 27.5°C, 29.0°C, and 31.5°C directly after fertilization. Differences in gene expression were measured after 12 and 48 hours. Results Analysis of differentially expressed genes indicated that increased temperatures may lead to oxidative stress, apoptosis, and a structural reconfiguration of the cytoskeletal network. Metabolic processes were downregulated, and the action of histones and zinc finger-containing proteins may have played a role in the long-term regulation upon heat stress. Conclusions Embryos responded differently depending on exposure time and temperature level. Embryos showed expression of stress-related genes already at a temperature of 29.0°C, but seemed to be able to counteract the initial response over time. By contrast, embryos at 31.5°C displayed continuous expression of stress genes. The genes that played a role in the response to elevated temperatures consisted of both highly conserved and coral-specific genes. These genes might serve as a basis for research into coral-specific adaptations to stress responses and global climate change.

  16. Embryos in the fast lane: high-temperature heart rates of turtles decline after hatching.

    Directory of Open Access Journals (Sweden)

    Wei-Guo Du

    Full Text Available In ectotherms such as turtles, the relationship between cardiovascular function and temperature may be subject to different selective pressures in different life-history stages. Because embryos benefit by developing as rapidly as possible, and can "afford" to expend energy to do so (because they have access to the yolk for nutrition, they benefit from rapid heart (and thus, developmental rates. In contrast, hatchlings do not have a guaranteed food supply, and maximal growth rates may not enhance fitness--and so, we might expect a lower heart rate, especially at high temperatures where metabolic costs are greatest. Our data on two species of emydid turtles, Chrysemys picta, and Graptemys pseudogeographica kohnii, support these predictions. Heart rates of embryos and hatchlings were similar at low temperatures, but heart rates at higher temperatures were much greater before than after hatching.

  17. Age as A Predictor of Embryo Quality Regardless of The Quantitative Ovarian Response.

    Science.gov (United States)

    Scheffer, Juliano Brum; Scheffer, Bruno Brum; de Carvalho, Rafaela Friche; Rodrigues, Joyce; Grynberg, Michael; Mendez Lozano, Daniel H

    2017-01-01

    One determining factor of a successful in vitro fertilization (IVF) cycle is embryo quality. The aim of the present study was to evaluate associations of embryo quality and reserve markers like age, FSH and AMH. In this prospective study, 120 infertile women, aged 21-44 years, undergoing routine exploration during an unstimulated cycle preceding assisted reproductive technology (ART) at our center were studied prospectively, from February 2011 to December 2014. Descriptive parameters and patient characteristics were reported as mean (SD) or median (range) depending on the distribution. Student's t test was performed for continuous variables, Wilcoxon and Pearson's Test were used for not distributed variables and Fisher's Test was performed for categorical variables. P<0.05 was considered statistically significant. Overall, at the time of investigation, patients had a mean age of 33.03 ± 4.15 years old. On cycle day three, serum anti-Mullerian hormone (AMH) level was 3.50 ± 1.54 ng/mL, serum follicle-stimulating hormone (FSH) level was 6.29 ± 1.53 mUI/ mL, at baseline, women had 16.57 ± 7.0 antral follicles. The mean of collected oocytes was 11.80 ± 5.25, embryo I+II was 2.46 ± 2.11. A greater number of embryos I+II was observed in young patients. By evaluating 120 patients, a significant relationship was observed between age and FSH (r=0.24, P=0.01), age with AMH (r=-0.22, P=0.02), age with collected oocytes (r=-0.23, P=0.03) and age with embryo I+II (r=-0.22, P=0.03). A significant relationship was also observed between antral follicle count (AFC) and AMH (r=0.29, P=0.01), AFC and the number of transferred embryo (r=-0.18, P=0.03), AFC and total dose of the drugs (r=-0.23, P=0.03). Significant relationship of FSH with total dose of drugs (r=0.19, P=0.02) was also observed. In addition, we determined significant relationships between AMH and the number of collected oocytes (r=0.38, P=0.01), AMH and the number of metaphase II oocytes (r= 0.35, P=0.01), AMH and

  18. Influence of female age on blastulation rate of embryo produced by ICSI

    Directory of Open Access Journals (Sweden)

    Jonathas Borges Soares

    2003-03-01

    Full Text Available OBJECTIVES: There is a tendency to adopt prolonged culture inolder patients; however there are no conclusive results about theinfluence of age on blastulation rate. Therefore, we decided to analyzethe influence of female age on prolonged culture results. METHODS:One hundred and seven ICSI procedures performed in our centerfrom January 1999 to December 2000 were retrospectively analyzed.The blastulation rate was verified and correlated with patient age.RESULTS: In average, 2.8 blastocysts/patient were transferred. Theblastulation rate for each age group was: 180 (32% in the group 40 years. The statistical analysis demonstrated a significantdifference (p < 0.05. CONCLUSION: The percentage of embryosthat achieved the blastocyst stage was different in each age groupand this percentage dropped as patient age increased. Female agemay influence on blastulation rate of pre-embryos, observing a dropin this rate as patient age increased.

  19. Effects of cryopreservation at various temperatures on the survival of kelp grouper (Epinephelus moara) embryos from fertilization with cryopreserved sperm.

    Science.gov (United States)

    Tian, Yongsheng; Chen, Zhangfan; Tang, Jiang; Duan, Huimin; Zhai, Jieming; Li, Bo; Ma, Wenhui; Liu, Jiangchun; Hou, Yunxia; Sun, Zhengxiang

    2017-04-01

    Fish embryo cryopreservation is highly important for the long-term preservation of genomic and genetic information; however, few successful cases of fish embryo cryopreservation have been reported over the past 60 years. This is the first study to use Epinephelus moara embryos from fertilization with cryopreserved sperm as experimental material. Embryos that developed to the 16-22 somite stage and tail-bud stage were treated with the vitrification solution PMG3T according to a five-step equilibration method and cryopreserved at various temperatures and storage duration. Only 19.9 ± 9.2% of 16-22 somite stage embryos and 1.3 ± 1.1% of tail-bud stage embryos survived when cooled at 4 °C for 60 min. In total, 8.0 ± 3.0% of 16-22 somite stage embryos survived when cooled at -25.7 °C for 30 min, 22.4 ± 4.7% of tail-bud stage embryos survived after 45 min of cooling at -25.7 °C, and none survived after 60 min. Only 2.0 ± 2.7% of embryos survived when cryopreserved at -140 °C for 20 min. However, 9.7% of tail-bud stage embryos survived after cryopreservation in liquid nitrogen (-196 °C) for 2 h. Most surviving embryos developed normally. Embryonic volume decreased and spherical segments appeared when embryos were treated with higher concentrations of vitrification solution. Additionally, the volume recovered gradually after rinsing with sucrose and seawater. This is the first estimate of the survival of E. moara embryos and larvae after cryopreservation. These findings provide a foundation for further explorations of fish embryo cryopreservation techniques. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Oocyte or embryo donation to women of advanced reproductive age: an Ethics Committee opinion.

    Science.gov (United States)

    2016-10-01

    Advanced reproductive age (ARA) is a risk factor for female infertility, pregnancy loss, fetal anomalies, stillbirth, and obstetric complications. Oocyte donation reverses the age-related decline in implantation and birth rates of women in their 40s and 50s and restores pregnancy potential beyond menopause. However, obstetrical complications in older patients remain high, particularly related to operative delivery and hypertensive and cardiovascular risks. Physicians should perform a thorough medical evaluation designed to assess the physical fitness of a patient for pregnancy before deciding to attempt transfer of embryos to any woman of advanced reproductive age (>45 years). Embryo transfer should be strongly discouraged or denied to women of ARA with underlying conditions that increase or exacerbate obstetrical risks. Because of concerns related to the high-risk nature of pregnancy, as well as longevity, treatment of women over the age of 55 should generally be discouraged. This statement replaces the earlier ASRM Ethics Committee document of the same name, last published in 2013 (Fertil Steril 2013;100:337-40). Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  1. Considerations on Temperature, Longevity and Aging

    OpenAIRE

    Conti, Bruno

    2008-01-01

    A modest reduction in body temperature prolongs longevity and possibly retards aging in both poikilotherm and homeotherm animals. Some of the possible mechanisms mediating these effects are considered here with respect to major aging models and theories.

  2. Considerations on temperature, longevity and aging.

    Science.gov (United States)

    Conti, B

    2008-06-01

    A modest reduction in body temperature prolongs longevity and may retard aging in both poikilotherm and homeotherm animals. Some of the possible mechanisms mediating these effects are considered here with respect to major aging models and theories.

  3. Temperature during the last week of incubation. III. Effects on chicken embryo physiology.

    Science.gov (United States)

    Maatjens, C M; van Roovert-Reijrink, I A M; Engel, B; van der Pol, C W; Kemp, B; van den Brand, H

    2017-05-01

    We investigated effects of eggshell temperature (EST) of 35.6, 36.7, 37.8, or 38.9°C applied from d of incubation (E) 15, E17, or E19 onward on chicken embryo physiology. A total of 2,850 first-grade eggs of a 43-week-old Ross 308 broiler breeder flock were incubated at an EST of 37.8°C until E15. From E15, E17, or E19 onward, eggs were incubated at an EST of 35.6, 36.7, 37.8, or 38.9°C. Plasma glucose, uric acid, and lactate concentrations, and hepatic glycogen amount and concentration were measured at E15, E17, E19, internal pipping (IP), external pipping (EP), and hatch.An EST of 38.9°C applied from E15 onward decreased the amount of hepatic glycogen from E19 to IP and resulted in a lower glycogen amount at IP compared to all other EST. At EP, when oxygen (O2) becomes largely available, an EST of 38.9°C resulted in a higher glycogen amount and concentration compared to IP, which suggests that plasma glucose between IP and EP might be used for building up hepatic glycogen reserves. However, hepatic glycogen levels remained considerably lower at IP, EP, and hatch at an EST of 38.9°C, compared to an EST of 35.6 and 36.7°C.Opposite to an EST of 38.9°C, from IP onward, an EST of 35.6°C resulted in a higher glycogen amount and concentration compared to all other EST, which might be caused by the higher O2 availability relative to the lower metabolic rate, which provided time to build up glycogen stores from excessive glucose. A higher availability of hepatic glycogen might contribute to an improved physiological status of the broiler chicken embryo toward hatch. Hepatic gluconeogenesis is crucial for developing embryos, as glucose is the major energy source from IP until hatch. At hatch, no effect of EST was found for glucose, uric acid, or lactate.Results of this study emphasize that EST of 35.6 and 36.7°C from E15 onward appear to be beneficial for chicken embryo physiology. © 2016 Poultry Science Association Inc.

  4. Vitrification of in vitro produced bovine embryos at different ages using one- and three-step addition of cryoprotective additives.

    Science.gov (United States)

    Saha, S; Suzuki, T

    1997-01-01

    The effect of embryo age on development and ratio of live: dead cells after vitrification and warming was examined. One-step and three-step addition of cryoprotectants in vitrification solution (40% ethylene glycol, 0.3 M trehalose and 12% polyvinylpyrrolidone) were compared using in vitro produced (IVP) bovine blastocysts and expanded blastocysts. Rates of development and hatching were 74.2% and 41.9% for Day 7, 57.8% and 23.8% for Day 8, 33.7% and 6.1% for Day 9 embryos with one-step addition. In three-step addition, those rates were 86.2% and 77.3% for Day 7, 72.3% and 39.0% for Day 8, 47.3% and 10.5% for Day 9 embryos. Day 7 embryos showed highest (P embryos with three-step addition was higher (P embryos (P bovine embryos against vitrification and the potential for three-step addition of cryoprotectants to yield a higher survival rate after warming than with one-step addition.

  5. Embryo sac chromosome doubling in Populus alba × P. glandulosa induced by high temperature exposure to produce triploids.

    Science.gov (United States)

    Li, Yanjie; Tian, Mengdi; Zhang, Pingdong

    2017-06-01

    To determine the effects of the hours after pollination and the treatment durations on triploid production and reveal the effective stages of embryo sac chromosome doubling by high temperature exposure. At least three catkins were sampled, and 80 ovules were used for the determination of the embryo sac developmental process. Catkins (2-74 h after pollination) were treated to induce embryo sac chromosome doubling. Cytological observations revealed that the embryo sac development was a consecutive and asynchronous process. Fertilization occurred 50 h after pollination. In the offspring seedlings, 167 triploids were detected and the highest efficiency of triploid production was 87.0%. Among all the induced triploids, the most effective treatment period of inducing embryo sac chromosome doubling is from 26 to 50 h after pollination, and 121 triploids were obtained, representing 72.46% of the sum of all triploids. GLM-Univariate analysis indicated significant differences among the hours after pollination (F = 4.516, p = 0.045). However, the differences between the treatment durations (F = 0.077, p = 0.791) were not significant. Correlation analysis between the proportion of each embryo sac's developmental stage and the percentage of triploid production indicated that the third mitotic division may be the most effective stage for 2n female gamete induction.

  6. High environmental temperature increases glucose requirement in the developing chicken embryo.

    Directory of Open Access Journals (Sweden)

    Roos Molenaar

    Full Text Available Environmental conditions during the perinatal period influence metabolic and developmental processes in mammals and avian species, which could impact pre- and postnatal survival and development. The current study investigated the effect of eggshell temperature (EST on glucose metabolism in broiler chicken embryos. Broiler eggs were incubated at a high (38.9°C or normal (37.8°C EST from day 10.5 of incubation onward and were injected with a bolus of [U-(13C]glucose in the chorio-allantoic fluid at day 17.5 of incubation. After [U-(13C]glucose administration, (13C enrichment was determined in intermediate pools and end-products of glucose metabolism. Oxidation of labeled glucose occurred for approximately 3 days after injection. Glucose oxidation was higher in the high than in the normal EST treatment from day 17.6 until 17.8 of incubation. The overall recovery of (13CO2 tended to be 4.7% higher in the high than in the normal EST treatment. An increase in EST (38.9°C vs 37.8°C increased (13C enrichment in plasma lactate at day 17.8 of incubation and (13C in hepatic glycogen at day 18.8 of incubation. Furthermore, high compared to normal EST resulted in a lower yolk-free body mass at day 20.9 (-2.74 g and 21.7 (-3.81 g of incubation, a lower hepatic glycogen concentration at day 18.2 (-4.37 mg/g and 18.8 (-4.59 mg/g of incubation, and a higher plasma uric acid concentration (+2.8 mg/mL/+43% at day 21.6 of incubation. These results indicate that the glucose oxidation pattern is relatively slow, but the intensity increased consistently with an increase in developmental stage of the embryo. High environmental temperatures in the perinatal period of chicken embryos increased glucose oxidation and decreased hepatic glycogen prior to the hatching process. This may limit glucose availability for successful hatching and could impact body development, probably by increased gluconeogenesis from glucogenic amino acids to allow anaerobic glycolysis.

  7. Long-term, large scale banking of citrus species embryos: comparisons between cryopreservation and other seed banking temperatures.

    Science.gov (United States)

    Malik, S K; Chaudhury, R; Pritchard, H W

    2012-01-01

    The long-term, large scale application of embryo cryopreservation has been assessed rarely and comparisons of viability loss for partially dried material with conventional seed bank storage conditions infrequently made. Five citrus species were cryopreserved following air drying of embryos (seed minus the testa) and embryonic axes: rough lemon (Citrus jambhiri), pommelo (C. grandis), mandarin (C. reticulata), citron (C. medica) and kagzi lime (C. aurantifolia). Although drying rates to c. 10 percent moisture content (MC) were approximately 10-times faster for isolated axes compared to embryos, the optimum MCs for cryopreservation were generally similar within a species, varying from c. 10 percent (C. jambhiri) to c. 20 percent (C. medica). Nonetheless, the hydration window for cryopreservation of the axis was usually wider than for the embryo. For all species, embryo or axis survival after cryopreservation ranged from 65 to 96 percent (C. medica axes), producing normal healthy seedlings from embryos and plantlets from axes without intervening callus growth in vitro. Whilst partially dried embryos of all five species survived fully liquid nitrogen vapour storage for 120 days, viability loss was rapid at -20 degree C, 5 degree C and ambient temperature, with a maximum interpolated half-life across these temperatures of c. 80 days for C. grandis at 5 degree C. The developed cryopreservation protocols were applied routinely to cryobank 377 accessions of Citrus germplasm from field genebanks, farmer's orchards, semi-wild and wild sources. After an average of 6.3 to 8.4 years cryo-storage, between 69 and 81 percent of accessions per species retained > 70 percent of the viability after desiccation. The results provide irrevocable evidence for the importance of cryopreservation for the banking of seeds of higher plants.

  8. [Pregnancy and obstetric outcomes of fresh embryo transfer versus frozen-thawed embryo transfer in women below 35 years of age].

    Science.gov (United States)

    Sun, Ling; Chen, Zhi-Heng; Yin, Min-Na; Deng, Yu

    2017-07-20

    To compare the obstetric and perinatal outcomes between fresh embryo transfer (ET) and frozen-thawed ET (the "freeze-all" strategy) and evaluate the benefits of the "freeze-all" embryo strategy for young patients. We reviewed a total of 2091 ET cycles performed between January, 2011 and December, 2015 in women aged 20-35 years, including 1295 fresh ET cycles and 796 frozen-thawed ET cycles. The demographic characteristics, ovarian stimulation syndrome, clinical pregnancy rates, live birth rate and the obstetric outcomes (gestational age, preterm delivery rate and mean birth weight) were compared between the two groups. The mean age of the patients receiving frozen-thawed ET cycles had a significantly younger age than those having fresh ET cycles (29.5 vs 30.2 years, P0.05), live birth rate (50.3% vs 47.0%; P>0.05), mean birth weight or gestational age between the two groups. The freeze-all policy produces similar pregnancy and obstetric outcomes with those of fresh ET. Our results support the hypothesis that the freeze-all strategy help to prevent OHSS with a good pregnancy rate.

  9. Proteomic Analysis Reveals Different Involvement of Embryo and Endosperm Proteins during Aging of Yliangyou 2 Hybrid Rice Seeds

    Science.gov (United States)

    Zhang, Ying-Xue; Xu, Heng-Heng; Liu, Shu-Jun; Li, Ni; Wang, Wei-Qing; Møller, Ian M.; Song, Song-Quan

    2016-01-01

    Seed aging is a process that results in a delayed germination, a decreased germination percentage, and finally a total loss of seed viability. However, the mechanism of seed aging is poorly understood. In the present study, Yliangyou 2 hybrid rice (Oryza sativa L.) seeds were artificially aged at 100% relative humidity and 40°C, and the effect of artificial aging on germination, germination time course and the change in protein profiles of embryo and endosperm was studied to understand the molecular mechanism behind seed aging. With an increasing duration of artificial aging, the germination percentage and germination rate of hybrid rice seeds decreased. By comparing the protein profiles from the seeds aged for 0, 10 and 25 days, a total of 91 and 100 protein spots were found to show a significant change of more than 2-fold (P rice seeds during artificial aging is caused by the development of hypoxic conditions in the embryos followed by ethanol accumulation. PMID:27708655

  10. Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate

    Science.gov (United States)

    Martin, Thomas E.; Ton, Riccardo; Nikilson, Alina

    2013-01-01

    Intrinsic processes are assumed to underlie life history expression and trade-offs, but extrinsic inputs are theorised to shift trait expression and mask trade-offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass-specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade-off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade-offs across species.

  11. Effect of maternal age on the ratio of cleavage and mitochondrial DNA copy number in early developmental stage bovine embryos.

    Science.gov (United States)

    Takeo, Shun; Goto, Hiroya; Kuwayama, Takehito; Monji, Yasunori; Iwata, Hisataka

    2013-01-01

    Age-associated deterioration in both the quality and quantity of mitochondria occurs in older women. The main aim of this study was to examine the effect of age on mitochondrial DNA copy number (mtDNA number) in early developmental stage bovine embryos as well as the dynamics of mtDNA number during early embryo development. Real-time PCR was used to determine mtDNA number. In vitro-produced embryos 48 h after insemination derived from Japanese black cows, ranging in age from 25 to 209 months were categorized based on their cleavage status. There was an overall negative relationship between the age of the cow and cleavage status, to the extent that the ratio of embryos cleaved over the 4-cell stage was greater in younger cows. The mtDNA number did not differ among the cleaved status of embryos. In the next experiment, oocytes collected from each donor cow were divided into 2 groups containing 10 oocytes each, in order to compare the mtDNA number of mature oocytes and early developmental stage embryos within individuals. Upon comparing the mtDNA number between oocytes at the M2 stage and early developmental stage 48 h post insemination, mtDNA number was found to decrease in most cows, but was found to increase in some cows. In conclusion, age affects the cleaving ability of oocytes, and very old cows (> 180 months) tend to have lower mtDNA numbers in their oocytes. The change in mtDNA number during early development varied among individual cows, although overall, it showed a tendency to decrease.

  12. Systolic and diastolic ventricular function in zebrafish embryos: Influence of norepenephrine, MS-222 and temperature

    Directory of Open Access Journals (Sweden)

    Mullins John J

    2008-02-01

    Full Text Available Abstract Background Zebrafish are increasingly used to study the influences of gene mutation and manipulation on cardiac development, structure and function. In this study, a video edge detection system was used to characterise, continuously, cardiac ventricle function in 2–5 days old zebrafish embryos embedded in 0.6% agar and examined under light microscopy at room temperature (22°C. Using video edge detection software (IonOptix Inc, the motion of a small region of the cardiac ventricle wall was converted to a continuous chart trace allowing analysis of wall motion amplitude (WMA and myocardial wall velocity during systole (MWVs and diastole (MWVd. Results Cardiac wall motion characteristics changed progressively from day 2 to 5 (WMA, 2-days, 17.6 ± 4.4 μm vs 5-days, 24.6 ± 4.7 μm, p Conclusion Video edge detection appears sufficiently sensitive to detect subtle changes in diastolic and systolic cardiac function during development and changes resulting from pharmacological and environmental interventions. Such measurements could be valuable in assessment of altered cardiac function after genetic manipulation.

  13. The effect of embryo donor age and parity on the superovulatory ...

    African Journals Online (AJOL)

    UFS

    does (young, 1 - 2 years) and nine multiparous does (adult, 3 - 4 years) were synchronised using controlled ... embryos was, however, lower due to the lower total number of embryos produced by the young donor does ..... Drion, P.V., De Roover, R., Houtain, J., McNamara, E.M., Remy, B., Sulon, J. & Beckers, J., 2001.

  14. Optimizing the number of cleavage stage embryos to transfer on day 3 in women 38 years of age and older: a Society for Assisted Reproductive Technology database study.

    Science.gov (United States)

    Stern, Judy E; Goldman, Marlene B; Hatasaka, Harry; MacKenzie, Todd A; Surrey, Eric S; Racowsky, Catherine

    2009-03-01

    To determine the optimal number of day 3 embryos to transfer in women >or=38 years by conducting an evidence-based evaluation. Retrospective analysis of 2000-2004 national SART data. National writing group. A total of 36,103 day 3 embryo transfers in women >or=38 years undergoing their first assisted reproductive technology cycle. None. Logistic regression was used to model the probability of pregnancy, delivery, and multiple births (twin or high order) based on age- and cycle-specific parameters. Pregnancy rates, delivery rates, and multiple rates increased up to transfer of three embryos in 38-year-olds and four in 39-year-olds; beyond this number, only multiple rates increased. In women >or=40 years, delivery rates and multiple rates climbed steadily with increasing numbers transferred. Multivariate analysis confirmed the statistically significant effect of age, number of oocytes retrieved, and embryo cryopreservation on delivery and multiple rates. Maximum FSH level was not an independent predictor by multivariate analysis. Use of intracytoplasmic sperm injection was associated with lowered delivery rate. No more than three or four embryos should be transferred in 38- and 39-year-olds, respectively, whereas up to five embryos could be transferred in >or=40-year-olds. Numbers of embryos to transfer should be adjusted according to number of oocytes retrieved and availability of excess embryos for cryopreservation.

  15. Influence of temperature and humidity in a equine embryo transfer program, in the Baixada Fluminense, Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Jhonnatha Paulo Oliveira

    2015-06-01

    Full Text Available ABSTRACT. Oliveira J.P., Jacob J.C.F., Jesus V.L.T. & Silva P.C.A. [Influence of temperature and humidity in a equine embryo transfer program, in the Baixada Fluminense, Rio de Janeiro.] Influência da temperatura e umidade ambiente em um programa de transferência de embriões equinos, na Baixada Fluminense, Rio de Janeiro. Revista Brasileira de Medicina Veterinária, 37(2:158- 162, 2015. Departamento de Reprodução e Avaliação Animal, Universidade Federal Rural do Rio de Janeiro, BR 465, Km 7, Seropédica, RJ 23890-970, Brasil. E-mail: juliorep@ufrrj.br This study aimed to evaluate the relationship between high environment temperature and humidity and reproductive rates in a equine embryo transfer program in Baixada Fluminense RJ. We evaluated the reproductive history of 60 donor mares and 111 recipient mares during summer of breeding seasons of 2008/2009, 2009/2010 and 2010/2011. Daily climatics data of environmental temperature (°C and relative humidity (% for the each breeding seasons were obtained from the web site of the National Institute of Meteorology (INMET, based on these data we calculated the temperature x humidity index (TUI wich measures the thermal comfort zone. The reproductive parameters assessed were embryo recovery rate (RR and pregnancy rate (PR. After the computation of reproductive and climatic data, these were compared to establish relationships between high temperatures and humidity on reproductive rates. There was a negative relationship between RR and high environmental temperatures, especially in the summer time, greater RR at 26°C (71% and lower RR at 27°C (51.4% (p <0.05. To PR there was a negative relationship to high environmental temperatures, the higher PR was obtained at 24°C (81.5% and lowest PG (35% at 27°C (p <0.05. We conclude that there are relationships between environmental variables and ET success.

  16. Comparative proteomic analysis of seed embryo proteins associated with seed storability in rice (Oryza sativa L) during natural aging.

    Science.gov (United States)

    Gao, Jiadong; Fu, Hua; Zhou, Xinqiao; Chen, Zhongjian; Luo, Yi; Cui, Baiyuan; Chen, Guanghui; Liu, Jun

    2016-06-01

    Seed storability is considered an important trait in rice breeding; however, the underlying regulating mechanisms remain largely unknown. Here, we carried out a physiological and proteomic study to identify proteins possibly related to seed storability under natural conditions. Two hybrid cultivars, IIYou998 (IIY998) and BoYou998 (BY998), were analyzed in parallel because they share the same restorer line but have significant differences in seed storability. After a 2-year storage period, the germination percentage of IIY998 was significantly lower than that of BY998, whereas the level of malondialdehyde was reversed, indicating that IIY998 seeds may suffer from more severe damage than BY998 during storage. However, we did not find correlation between activities of antioxidant enzymes of superoxide dismutase, peroxidase, and catalase and seed storability. We identified 78 embryo proteins in embryo whose abundance varied more than 3-fold different during storage or between IIY998 and BY998. More proteins changed in abundance in IIY998 embryo (67 proteins) during storage than in BY998 (10 proteins). Several redox regulation proteins, mainly glutathione-related proteins, exhibited different degree of change during storage between BY998 and IIY998 and might play an important role protecting embryo proteins from oxidation. In addition, some disease/defense proteins, including DNA-damage-repair/toleration proteins, and a putative late embryogenesis abundant protein were significantly downregulated in IIY998, whereas their levels did not change in BY998, indicating that they might be correlated with seed storability. Further studies on these candidate seed storage proteins might help improve our understanding of seed aging. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Embryo splitting

    Directory of Open Access Journals (Sweden)

    Karl Illmensee

    2010-04-01

    Full Text Available Mammalian embryo splitting has successfully been established in farm animals. Embryo splitting is safely and efficiently used for assisted reproduction in several livestock species. In the mouse, efficient embryo splitting as well as single blastomere cloning have been developed in this animal system. In nonhuman primates embryo splitting has resulted in several pregnancies. Human embryo splitting has been reported recently. Microsurgical embryo splitting under Institutional Review Board approval has been carried out to determine its efficiency for blastocyst development. Embryo splitting at the 6–8 cell stage provided a much higher developmental efficiency compared to splitting at the 2–5 cell stage. Embryo splitting may be advantageous for providing additional embryos to be cryopreserved and for patients with low response to hormonal stimulation in assisted reproduction programs. Social and ethical issues concerning embryo splitting are included regarding ethics committee guidelines. Prognostic perspectives are presented for human embryo splitting in reproductive medicine.

  18. Drifting Away of a FET Endpoint: The Heart Rate in Danio rerio Embryos is Extremely Sensitive to Variation in Ambient Temperature.

    Science.gov (United States)

    Schweizer, Mona; Dieterich, Andreas; Triebskorn, Rita; Köhler, Heinz-R

    2017-10-20

    Beyond the mere detection of presence or absence of heart beat in zebrafish (Danio rerio) embryos in a fish embryo test conducted referring to the OECD TG 236 at 48 hpf (hours post fertilization) onwards, embryo heart rate may serve as an additional and very sensitive endpoint in ecotoxicological studies. But by including heart rate as a sublethal endpoint, care has to be taken of separating effects exerted by a tested compound from those exerted by temperature. Therefore, profound knowledge on the natural variation of zebrafish heart rates at defined temperatures as a basis for the assessment of gained results is mandatorily needed. As such continuous information in D. rerio is lacking from the literature, we designed a study covering a span of 12°C (from 18 to 30°C in steps of 2°C) to quantify the relationship between heart rate and temperature in D. rerio embryos 48 hpf. Conducting a multiple regression analysis, we found a considerably strong relationship between treatment temperature and the log10 of the heart rate, ranging from 82.8 beats per minute at 18°C to 218.0 beats per minute at 30°C. Our results therefore may serve as a reference for heart rates measured under normal conditions to be able to detect potential effects of contaminants in other studies when working under certain temperatures.

  19. Carry-over effects of multiple stressors on benthic embryos are mediated by larval exposure to elevated UVB and temperature.

    Science.gov (United States)

    Fischer, Jeannine; Phillips, Nicole E

    2014-07-01

    Damaging effects of UVB in conjunction with other stressors associated with global change are well-established, with many studies focused on vulnerable early life stages and immediate effects (e.g., mortality, developmental abnormalities). However, for organisms with complex life cycles, experiences at one life stage can have carry-over effects on later life stages, such that sublethal effects may mediate later vulnerability to further stress. Here, we exposed embryos in benthic egg masses of the New Zealand intertidal gastropod Siphonaria australis to treatments of either periodic stress (e.g., elevated UVB, salinity, and water temperature mimicking tidepool conditions in which egg masses are commonly found during summer) or control conditions (low UVB, ambient salinity, and water temperatures). Although there was high mortality from stressed egg masses, 24% of larvae hatched successfully. We then exposed the hatching larvae from both egg mass treatments to different combinations of water temperature (15 or 20 °C) and light (high UVB or shade) 12 h per day for 10 days. The most stressful larval conditions of 20 °C/high UVB resulted in low survival and stunted growth. Carry-over effects on survival were apparent for shaded larvae exposed to elevated temperature, where those from stressed egg masses had 1.8× higher mortality than those from control egg masses. Shaded larvae were also larger and had longer velar cilia if they were from control egg masses, independent of larval temperature. These results demonstrate that previous experience of environmental stress can influence vulnerability of later life stages to further stress, and that focus on a single life stage will underestimate cumulative effects of agents of global change. © 2013 John Wiley & Sons Ltd.

  20. Intravenous intralipid therapy is not beneficial in having a live delivery in women aged 40-42 years with a previous history of miscarriage or failure to conceive despite embryo transfer undergoing in vitro fertilization-embryo transfer.

    Science.gov (United States)

    Check, J H; Check, D L

    2016-01-01

    To evaluate the efficacy of intralipid intravenous infusion in achieving a live pregnancy following IVF--embryo transfer in women of advanced reproductive age (40-42 years). A matched control was performed. Women aged 40-42 with a previous history of miscarriage or who failed to conceive despite previous embryo transfer who entered an IVF program were offered intravenous intralipid therapy (four ml of 20% liposyn II in 100 ml normal saline over one hour) during the mid-follicular phase. Clinical pregnancy rates (eight weeks with viable gestation) and live delivered pregnancy rates were then determined and compared. The results were evaluated after ten matched cycles. There were no clinical pregnancies in those receiving intralipid vs. a 40% clinical and a 30% live delivered pregnancy rate in the untreated controls (p = 0.087, Fisher's exact test). The study was terminated because of these preliminary data. In the test tube, adding intralipid to natural killer cells can inhibit their cytolytic action. However, the use of intravenous intralipid to suppress natural killer cell activity does not seem to improve the chance of a live delivery in women aged 40-42 years with a previous history of miscarriage. In fact this therapy may actually be detrimental in this age group. Since efficacy of this therapy was not found in a group of advanced reproductive age, it is not clear why this should be effective for a younger population. A controlled study for the younger group is needed. Perhaps such a study could be limited to only those with miscarriage rather than also concluding failure to conceive despite embryo transfer. Intralipid failed to improve live delivered pregnancy rates in women with prior miscarriage or previous failure with embryo transfer.

  1. Genetic variation underlies temperature tolerance of embryos in the sea urchin Heliocidaris erythrogramma armigera.

    Science.gov (United States)

    Lymbery, R A; Evans, J P

    2013-10-01

    Ocean warming can alter natural selection on marine systems, and in many cases, the long-term persistence of affected populations will depend on genetic adaptation. In this study, we assess the potential for adaptation in the sea urchin Heliocidaris erythrogramma armigera, an Australian endemic, that is experiencing unprecedented increases in ocean temperatures. We used a factorial breeding design to assess the level of heritable variation in larval hatching success at two temperatures. Fertilized eggs from each full-sibling family were tested at 22 °C (current spawning temperature) and 25 °C (upper limit of predicted warming this century). Hatching success was significantly lower at higher temperatures, confirming that ocean warming is likely to exert selection on this life-history stage. Our analyses revealed significant additive genetic variance and genotype-by-environment interactions underlying hatching success. Consistent with prior work, we detected significant nonadditive (sire-by-dam) variance in hatching success, but additionally found that these interactions were modified by temperature. Although these findings suggest the potential for genetic adaptation, any evolutionary responses are likely to be influenced (and possibly constrained) by complex genotype-by-environment and sire-by-dam interactions and will additionally depend on patterns of genetic covariation with other fitness traits. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  2. Temperature, age, and recurrence of febrile seizure

    NARCIS (Netherlands)

    M. van Stuijvenberg (Margriet); E.W. Steyerberg (Ewout); G. Derksen-Lubsen (Gerarda); H.A. Moll (Henriëtte)

    1998-01-01

    textabstractOBJECTIVE: Prediction of a recurrent febrile seizure during subsequent episodes of fever. DESIGN: Study of the data of the temperatures, seizure recurrences, and baseline patient characteristics that were collected at a randomized placebo controlled trial of ibuprofen

  3. Acetylcholinesterase-positive innervation is present at undifferentiated stages of the sea turtle Lepidochelis olivacea embryo gonads: implications for temperature-dependent sex determination.

    Science.gov (United States)

    Gutiérrez-Ospina, G; Jiménez-Trejo, F J; Favila, R; Moreno-Mendoza, N A; Granados Rojas, L; Barrios, F A; Díaz-Cintra, S; Merchant-Larios, H

    1999-07-19

    In embryos of different reptile species, incubation temperature triggers a cascade of endocrine events that lead to gonad sex differentiation. The cellular and molecular mechanisms by which temperature sets in motion this process are still controversial. Here, we begin evaluating the possible participation of the nervous system in temperature-dependent sex determination by showing the existence and origin of acetylcholinesterase (AchE)-positive nerve fibers in undifferentiated gonads of the Lepidochelys olivacea (L. olivacea) sea turtle putative male and female embryos, along the thermosensitive period for sex determination (TPSD; stages 20-27). AChE-positive nerve bundles and fibers were readily visualized until developmental stage 24 and thereafter. DiI injections and confocal imaging showed that some of these gonadal nerves arise from the lower thoracic and upper lumbar spinal cord levels, and might thus be sensory in nature. Because the vertebrate spinal cord is capable of integrating by itself thermoregulatory responses with no intervention of uppermost levels of the central nervous system, we also evaluated spinal cord maturation during the TPSD. The maturation of the spinal cord was more advanced in putative female than in male embryos, when sex determination is taking place for each sex; this process starts and ends earlier in male than in female embryos. Together these observations open the possibility that the spinal cord and the innervation derived from it could play a direct role in driving or modulating the process of temperature-dependent gonad sex determination and/or differentiation, particularly in female L. olivacea embryos.

  4. Critical windows in embryonic development: Shifting incubation temperatures alter heart rate and oxygen consumption of Lake Whitefish (Coregonus clupeaformis) embryos and hatchlings.

    Science.gov (United States)

    Eme, J; Mueller, C A; Manzon, R G; Somers, C M; Boreham, D R; Wilson, J Y

    2015-01-01

    Critical windows are periods of developmental susceptibility when the phenotype of an embryonic, juvenile or adult animal may be vulnerable to environmental fluctuations. Temperature has pervasive effects on poikilotherm physiology, and embryos are especially vulnerable to temperature shifts. To identify critical windows, we incubated whitefish embryos at control temperatures of 2°C, 5°C, or 8°C, and shifted treatments among temperatures at the end of gastrulation or organogenesis. Heart rate (fH) and oxygen consumption ( [Formula: see text] ) were measured across embryonic development, and [Formula: see text] was measured in 1-day old hatchlings. Thermal shifts, up or down, from initial incubation temperatures caused persistent changes in fH and [Formula: see text] compared to control embryos measured at the same temperature (2°C, 5°C, or 8°C). Most prominently, when embryos were measured at organogenesis, shifting incubation temperature after gastrulation significantly lowered [Formula: see text] or fH. Incubation at 2°C or 5°C through gastrulation significantly lowered [Formula: see text] (42% decrease) and fH (20% decrease) at 8°C, incubation at 2°C significantly lowered [Formula: see text] (40% decrease) and fH (30% decrease) at 5°C, and incubation at 5°C and 8°C significantly lowered [Formula: see text] at 2°C (27% decrease). Through the latter half of development, [Formula: see text] and fH in embryos were not different from control values for thermally shifted treatments. However, in hatchlings measured at 2°C, [Formula: see text] was higher in groups incubated at 5°C or 8°C through organogenesis, compared to 2°C controls (43 or 65% increase, respectively). Collectively, these data suggest that embryonic development through organogenesis represents a critical window of embryonic and hatchling phenotypic plasticity. This study presents an experimental design that identified thermally sensitive periods for fish embryos. Crown Copyright

  5. Interchangeable effects of gibberellic acid and temperature on embryo growth, seed germination and epicotyl emergence in Ribes multiflorum ssp. sandalioticum (Grossulariaceae).

    Science.gov (United States)

    Mattana, E; Pritchard, H W; Porceddu, M; Stuppy, W H; Bacchetta, G

    2012-01-01

    Morphophysiological dormancy was investigated in seeds of Ribes multiflorum Kit ex Roem et Schult. ssp. sandalioticum Arrigoni, a rare mountain species endemic to Sardinia (Italy). There were no differences in imbibition rates between intact and scarified seeds, suggesting a lack of physical dormancy, while methylene blue solution (0.5%) highlighted a preferential pathway for solution entrance through the raphe. Embryos were small at seed dispersal, with an initial embryo:seed ratio (E:S) of ca. 0.2 (embryo length, ca. 0.5 mm), whereas the critical E:S ratio for germination was three times longer (ca. 0.6). Gibberellic acid (GA(3), 250 mg · l(-1)) and warm stratification (25 °C for 3 months) followed by low temperature (<15 °C) enhanced embryo growth rate (maximum of ca. 0.04 mm · day(-1) at 10 °C) and subsequent seed germination (radicle emergence; ca. 80% at 10 °C). Low germination occurred at warmer temperatures, and cold stratification (5 °C for 3 months) induced secondary dormancy. After radicle emergence, epicotyl emergence was delayed for ca. 2 months for seeds from three different populations. Mean time of epicotyl emergence was affected by GA(3) . Seeds of this species showed non-deep simple (root) - non-deep simple (epicotyl) morphophysiological dormancy, highlighting a high synchronisation with Mediterranean seasonality in all the investigated populations. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  6. Physiology and Endocrinology Symposium: influence of cattle genotype (Bos indicus vs. Bos taurus) on oocyte and preimplantation embryo resistance to increased temperature.

    Science.gov (United States)

    Paula-Lopes, F F; Lima, R S; Satrapa, R A; Barros, C M

    2013-03-01

    High environmental temperatures during the hot months of the year reduce reproductive performance in cattle. Summer heat stress depression in fertility is a multifactorial problem; however, there is evidence that the bovine germinal vesicle and maturing oocyte, as well as the early embryo, are major targets of the deleterious effects of heat stress. Such adverse effects are less pronounced in heat-tolerant breeds (Bos indicus) than heat-sensitive breeds (Bos taurus). This genetic variation results from the greater thermoregulatory ability and cellular thermoresistance of heat-tolerant breeds. Heat-induced oocyte cellular damage occurs in both cytoplasmic and nuclear compartments. Heat shock has been shown to reduce oocyte nuclear maturation, induce apoptosis, compromise oocyte cytoskeleton, and impair oocyte mitochondrial function and developmental competence. However, the oocyte cytoplasm is more susceptible to heat shock than the nucleus. This effect is greater for Bos taurus than Bos indicus oocytes. The detrimental effects of heat shock are also critical during the first cleavage divisions when most of the embryonic genome is inactive; however, the bovine embryo becomes more resistant to increased temperature as it proceeds through development. Several studies demonstrated that Bos indicus embryos are more thermotolerant than Bos taurus embryos. Adaptive changes involved in acquisition of thermotolerance are likely derived from changes in gene expression and (or) activity of biochemical molecules that control cellular functions against stress. Recently, molecules such as IGF-I and caspase inhibitor z-DEVD-fmk have been shown to exert a thermoprotective role, rescuing heat-induced oocyte and embryo cellular damage and developmental competence. Therefore, cattle genotype and thermoprotective molecules can be considered as an alternative to modulate the effects of increased temperature in reproductive function.

  7. Mathematical models for growth in alligator (Alligator mississippiensis) embryos developing at different incubation temperatures.

    Science.gov (United States)

    Bardsley, W G; Ackerman, R A; Bukhari, N A; Deeming, D C; Ferguson, M W

    1995-08-01

    A variety of model-based (growth models) and model-free (cubic splines, exponentials) equations were fitted using weighted-nonlinear least squares regression to embryonic growth data from Alligator mississippiensis eggs incubated at 30 and 33 degrees C. Goodness of fit was estimated using a chi 2 on the sum of squared, weighted residuals, and run and sign tests on the residuals. One of the growth models used (Preece & Baines, 1978) was found to be superior to the classical growth models (exponential, monomolecular, logistic, Gompertz, von Bertalanffy) and gave an adequate fit to all longitudinal measures taken from the embryonic body and embryonic mass. However, measurements taken from the head could not be fitted by growth models but were adequately fitted by weighted least squares cubic splines. Data for the stage of development were best fitted by a sum of 2 exponentials with a transition point. Comparison of the maximum growth rates and parameter values, indicated that the growth data at 30 degrees C could be scaled to 33 degrees C to multiplying the time by a scaling factor of 1.2. This is equivalent to a Q10 of about 1.86 or, after solving the Arrhenius equation, an E++ of 46.9 kJmol-1. This may be interpreted as indicating a common rate-limiting step in development at the 2 temperatures.

  8. Chill sensitivity of honey bee, Apis mellifera, embryos.

    Science.gov (United States)

    Collins, Anita M; Mazur, Peter

    2006-08-01

    Improved methods for preservation of honey bee, Apis mellifera L., germplasm would be very welcome to beekeeping industry queen breeders. The introduction of two parasites and the emergence of an antibiotic resistant disease have increased demands for resistant stock. Techniques for artificial insemination of queens are available, and semen has been cryopreserved with limited success. However, cryopreservation of embryos for rearing queens would mesh well with current practices and also provide drones (haploid males). Eggs at five ages between twenty-four hours and sixty-two hours were exposed to 0, -6.6, and/or -15 degrees C for various times, and successful hatch measured. Honey bee embryos show chill sensitivity as do other insect embryos, and the rate of chill injury increases dramatically with decrease in holding temperature. The 48 h embryos in both groups showed the greatest tolerance to chilling, although 44 h embryos were only slightly less so.

  9. INFLUENCE OF A LOW TEMPERATURE AGEING ON THE ...

    African Journals Online (AJOL)

    The effect of a low temperature ageing treatment on the hardness, tensile and corrosion characteristics of sand cast Al-6.5%Si-0.35%Mg alloy was studied. The temper conditions are low temperature ageing at 90oC, 95oC, 100oCand 105oC respectively followed by ageing to 180oC for 2 hrs. This was compared with the ...

  10. Effects of recipient oocyte age and interval from fusion to activation on development of buffalo (Bubalus bubalis) nuclear transfer embryos derived from fetal fibroblasts.

    Science.gov (United States)

    Lu, F; Jiang, J; Li, N; Zhang, S; Sun, H; Luo, C; Wei, Y; Shi, D

    2011-09-15

    The objective was to investigate the effect of recipient oocyte age and the interval from activation to fusion on developmental competence of buffalo nuclear transfer (NT) embryos. Buffalo oocytes matured in vitro for 22 h were enucleated by micromanipulation under the spindle view system, and a fetal fibroblast (pretreated with 0.1 μg/mL aphidicolin for 24 h, followed by culture for 48 h in 0.5% fetal bovine serum) was introduced into the enucleated oocyte, followed by electrofusion. Both oocytes and NT embryos were activated by exposure to 5 μM ionomycin for 5 min, followed by culture in 2 mM 6-dimethyl-aminopurine for 3 h. When oocytes matured in vitro for 28, 29, 30, 31, or 32 h were activated, more oocytes matured in vitro for 30 h developed into blastocysts in comparison with oocytes matured in vitro for 32 h (31.3 vs 19.9%, P fusion (P fusion. However, 3 of 16 recipients were pregnant following transfer of blastocysts developed from the NT embryos activated at 3 h after fusion, and two of these recipients maintained pregnancy to term. We concluded that the developmental potential of buffalo NT embryos was related to recipient oocyte age and the interval from fusion to activation. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Competence classification of cumulus and granulosa cell transcriptome in embryos matched by morphology and female age

    DEFF Research Database (Denmark)

    Borup, Rehannah; Thuesen, Lea Langhoff; Andersen, Claus Yding

    2016-01-01

    compartments. DESIGN: A case-control study. SETTING: University based facilities for clinical services and research. PATIENTS: MGC and CC samples from 60 women undergoing IVF treatment following the long GnRH-agonist protocol were collected. Samples from 16 oocytes where live birth was achieved and 16 age...... prediction analysis using machine learning algorithms (support vector machines) with performance estimation by leave-one-out cross validation and independent validation on an external data set. RESULTS: We defined a signature of 30 genes expressed in CC predictive of live birth. This live birth prediction...

  12. Ongoing and cumulative pregnancy rate after cleavage-stage versus blastocyst-stage embryo transfer using vitrification for cryopreservation: impact of age on the results.

    Science.gov (United States)

    Fernández-Shaw, S; Cercas, R; Braña, C; Villas, C; Pons, I

    2015-02-01

    To determine if blastocyst transfer increases the ongoing and cumulative pregnancy rates, compared with day 3 embryo transfer, in women of all ages when at least 4 zygotes are obtained. Prospective study including patients undergoing a first IVF/ICSI treatment and assigned to cleavage stage (n = 46) or blastocyst (n = 58) embryo transfer. Supernumerary embryos were vitrified and patients failing to achieve an ongoing pregnancy after fresh embryo transfer would go through cryopreserved cycles. The main outcome measure was the ongoing pregnancy rate after the fresh IVF/ICSI transfer and the cumulative ongoing pregnancy rate. Results were also analyzed according to age (under 35 and 35 or older). A majority of patients (96.6 %) had a blastocyst transfer when at least 4 zygotes were obtained. The ongoing pregnancy rate was significantly higher in the day-5 group compared with the day-3 group (43.1 % vs. 24 %, p = 0.041). The cumulative ongoing pregnancy rate was higher (but not significantly) with blastocyst than with cleavage stage embryos (56.8 % vs. 43.4 %, p = 0.174). When analysed by age, patients 35 or older showed significantly higher ongoing pregnancy rate (48.4 % vs. 19.3 %, p = 0.016) and cumulative ongoing pregnancy rate (58 % vs. 25.8 %, p = 0.01) in the day-5 group compared to the day-3 group, while no such differences were observed in women under 35. Blastocyst transfer can be suggested whenever there are at least 4 zygotes. While there are no differences in women under 35, the benefit of this option over cleavage stage transfer could be significant in women 35 or older.

  13. Effect of two activation treatments and age of blastomere karyoplasts on in vitro development of bovine nuclear transfer embryos

    DEFF Research Database (Denmark)

    Booth, P J; Holm, P; Vajta, G

    2001-01-01

    .7 +/- 5.1 vs. 31.4 +/- 4.5 [mean +/- SEM]). In contrast, nuclear transfer blastocyst rates per fused embryo were lower (P rates using day 3, 4, and 5 donors and using CHX and DMAP activation treatments were 31.9 +/- 5.0, 31.7 +/- 6.2, 20.......4 +/- 7.3 and 27.8 +/- 4.7, 20.1 +/- 7.5, 12.7 +/- 8.3, respectively. Blastocyst rate per fused embryo was negatively correlated (P = 0.0091) with the total number of blastomeres per donor embryo. Despite this inverse relationship, the calculated potential blastocyst yield per donor embryo was positively...

  14. Effects of Aging Temperature on Moisture Absorption of Perforated GFRP

    National Research Council Canada - National Science Library

    Eslami, Shiva; Taheri-Behrooz, Fathollah; Taheri, Farid

    2012-01-01

      This paper examines the effects of aging on the flexural stiffness and bending loading capacity of a perforated glass fiber-reinforced epoxy composite subjected to combined moisture and elevated temperature...

  15. Aging meat at room and cold temperatures on meat quality and aging loss of sheep carcass

    Directory of Open Access Journals (Sweden)

    Roswita Sunarlim

    2001-03-01

    Full Text Available The aim of this research is to compare the quality of meat of local carcass sheep between fresh and aging meat stored at room temperature for 12 hours, at 4oC for one day and one week. For that purpose a study of aging carcass involving 12 local sheep (male and female with different ages was carried out by separating carcass into two parts: (1 the right portion was aged on 4oC for one day and one week, room temperature for 12 hours, and (2 the left portion as control without aging. A factorial design 2x2 (2 sexes and aging vs without aging for three kinds of aging on quality of meat. A factorial design 2x3 (2 sexes and 3 kinds of aging on aging loss. Replicate twice was carried out with different ages (old and young sheep. Parameter measured were pH, warter-holding capacity, cooking loss, color, tenderness, carcass weight loss. There was decrease in pH, increase in tenderness value for aged meat that stored at room temperature for 12 hours (1.84 kg, at cold temperature for one day (2.03 kg, but tenderness value was the most (0.92 kg at cold temperature for one week compared to fresh meat (3.41, 4.06, and 3.66 kg. Lightness color (l, red color (a and yellow color (b for aged meat is usually increase compare to fresh meat, except for aged meat stored at room temperature for 12 hours was decrease significant. Water-holding capacity and cooking loss value of aged meat was not significant compared to fresh meat. Aging loss of aged meat stored at 4oC for one week (13.58% was significant compared to aged meat stored at room temperature (2.42% and 4oC for one day (2.90%.

  16. [Cryopreservation of early human embryo stages].

    Science.gov (United States)

    Vökler, T; Fliess, F R

    1988-01-01

    A short review of freezing procedures applied to early human embryos is given. It is noted that human embryos survived freezing and thawing at a developmental stage of 1. cell to blastocyst. But it seems to be necessary to use for any developmental stage of early embryo a special freezing and thawing method. Embryo survival is correlated with their morphologic features where as neither age of embryos nor developmental stage were involved in freezing and thawing ability.

  17. Semmes-Weinstein Monofilaments: Influence of Temperature, Humidity, and Age

    NARCIS (Netherlands)

    Haloua, Max H.; Sierevelt, Inger; Theuvenet, Willem J.

    2011-01-01

    Purpose: To determine whether the buckling force of Semmes-Weinstein monofilaments is influenced by changes in temperature, humidity, and aging. Methods: We tested 16 Semmes-Weinstein monofflaments from North Coast Medical, varying in age from new to 12 years old. From each kit, we used the

  18. The effect of aging temperature on natural zeolite modification

    Science.gov (United States)

    Purbaningtias, Tri Esti; Wiyantoko, Bayu; Kurniawati, Puji; Prasetyoko, Didik; Suprapto

    2017-12-01

    This study investigated the effect of aging temperature on the development of natural zeolite. Natural zeolite was modified by surfactant treatment using cetyltrimethylammonium bromide as the cationic surfactant for mesopore template. Characterization materials used XRD, FTIR and nitrogen physisorption. XRD diffractograms showed variations aging temperature caused the crystallinity and mesopores structure of natural zeolite (MZ). All FTIR spectra showed the presence of silanol and siloxane in the sample MZ and modified of natural zeolite (MMZ). It is proved that all the samples MZ and MMZ on any variation is economical silica-based material. Meanwhile, physisorption nitrogen profiles gave information that the addition of aging temperatures increased the surface area of the modified material but at a temperature of 100°C, the surface area of MMZ becomes smaller due to the water loss system.

  19. Impact of genotype, age of tree and environmental temperature on ...

    African Journals Online (AJOL)

    Flow cytogenetic analysis of androgenic embryos originating from anther and microspore culture was done after a first generation of regenerants. All androgenic embryos, the first generation from microspore culture were haploid, while 50% of the regenerants originating from anther culture were haploid, and the other half ...

  20. Development of rabbit embryos during a 96-h period of in vitro culture after superovulatory treatment under conditions of elevated ambient temperature.

    Science.gov (United States)

    Cheng, H; Dooley, M P; Hopkins, S M; Anderson, L L; Yibchok-anun, S; Hsu, W H

    1999-08-16

    The effects of elevated ambient temperature on the response to exogenous gonadotropins were evaluated in female New Zealand White rabbits exposed to 33+/-1 degrees C (mean +/- SE) and 10-30% relative humidity (8 h/day) during a 5-day period. Does were treated with pFSH (0.3 mg/0.3 ml Standard Armour) twice daily during three consecutive days with a minimum interval of 8 h between injections. Six hours after the last FSH injection all does were removed from the experimental chamber, given hCG (25 IU/kg) and paired overnight. Nineteen hours after pairing, embryos were flushed from the reproductive tracts, evaluated, and subjected to in vitro culture during a 96-h period. The ovulatory responses to exogenous gonadotropins and fertilization rates did not differ significantly under conditions of elevated ambient temperature, whereas fewer blastocysts and increased number of degenerate embryos were observed after culture. We conclude that although hyperthermia was induced during exposure to elevated ambient temperature, it did not alter the ovulatory responses to gonadotropin treatment and plasma concentrations of FSH and LH compared with does in a thermoneutral environment. Exposure of donor rabbits to elevated ambient temperature before mating, however, increased embryonic degeneration.

  1. Microstructural Evolution and Mechanical Behavior of High Temperature Solders: Effects of High Temperature Aging

    Science.gov (United States)

    Hasnine, M.; Tolla, B.; Vahora, N.

    2017-12-01

    This paper explores the effects of aging on the mechanical behavior, microstructure evolution and IMC formation on different surface finishes of two high temperature solders, Sn-5 wt.% Ag and Sn-5 wt.% Sb. High temperature aging showed significant degradation of Sn-5 wt.% Ag solder hardness (34%) while aging has little effect on Sn-5 wt.% Sb solder. Sn-5 wt.% Ag experienced rapid grain growth as well as the coarsening of particles during aging. Sn-5 wt.% Sb showed a stable microstructure due to solid solution strengthening and the stable nature of SnSb precipitates. The increase of intermetallic compound (IMC) thickness during aging follows a parabolic relationship with time. Regression analysis (time exponent, n) indicated that IMC growth kinetics is controlled by a diffusion mechanism. The results have important implications in the selection of high temperature solders used in high temperature applications.

  2. Antral follicle populations and embryo production--in vitro and in vivo--of Bos indicus-taurus donors from weaning to yearling ages.

    Science.gov (United States)

    Silva-Santos, K C; Santos, G M G; Koetz Júnior, C; Morotti, F; Siloto, L S; Marcantonio, T N; Urbano, M R; Oliveira, R L; Lima, D C M; Seneda, M M

    2014-04-01

    Interest in indicus-taurus cattle has been increasing, as these animals are likely to present the best characteristics of Zebu and European bovine breeds. The aim of this study was to compare the embryo production of indicus-taurus donors with high vs low antral follicle counts obtained by ovum pickup/in vitro production (OPU/IVP) and superovulation (SOV)/embryo collection. Braford females at weaning age (3/8 Nelore × 5/8 Hereford, n = 137, 9 ± 1 month old) were subjected to six serial ovarian ultrasonographs and were assigned to two groups according to the number of antral follicles ≥ 3 mm as follows: G-High antral follicular count (AFC, n = 20, mean ≥ 40 follicles) and G-Low AFC (n = 20, mean ≤ 10 follicles). When the females (n = 40) reached 24 months of age, they were subjected to both OPU/IVP and SOV/embryo collection. The average number of follicles remained highly stable throughout all of the ultrasound evaluations (range 0.90-0.92). The mean number of COCs recovered (36.90 ± 13.68 vs 5.80 ± 3.40) was higher (p taurus females. © 2014 Blackwell Verlag GmbH.

  3. Holding equine oocytes in a commercial embryo-holding medium: New perspective on holding temperature and maturation time.

    Science.gov (United States)

    Dini, Pouya; Bogado Pascottini, Osvaldo; Ducheyne, Kaatje; Hostens, Miel; Daels, Peter

    2016-09-15

    In the present study, we examined the effect of holding equine oocytes in Syngro embryo holding medium (EHM) overnight at either 4 °C, 17 °C, or 22 °C to 25 °C, on the time to maturation and developmental competence. We also examined the effect of placing denuded oocyte without extruded polar body back in maturation condition on subsequent maturation rate. In experiment 1, cumulus-oocyte complexes (COCs) were recovered postmortem and placed in EHM at 22 °C to 25 °C for 18 to 20 hours (OH) or placed directly in maturation (DM). The maturation rate was assessed after 22, 24, or 28 hours of culture. After denuding cumulus cells at 22 or 24 hours, oocytes without obvious polar body were placed back into culture and reassessed at subsequent time points. At 22 hours, a higher proportion of oocytes placed in OH achieved nuclear maturation than those placed in DM (63% and 37%, respectively, P = 0.008). At 24 and 28 hours, no significant differences in the % MII stage oocytes were observed between OH and DM. The nuclear maturation rate for OH oocytes was similar at 22, 24, and 28 hours, indicating that the maximum maturation rate was reached at an earlier time than that in DM. Oocytes fertilized by intracytoplasmic sperm injection resulted in a 7.1% and 6.3% blastocyst rate for OH and DM, respectively. Denuding oocytes after 22 hours or more of culture did not have an adverse effect on the final nuclear maturation rate. After 28 hours of culture, the same nuclear maturation rate (MII) was reached for nondenuded oocytes and oocytes denuded after 22 hours of 24 hours of culture. In experiment 2, COCs were held overnight at room temperature in EHM, then placed in maturation for 20, 22, and 28 hours. Nuclear maturation rate was significantly lower at 20 hours than 22 and 28 hours of culture and was similar at 22 and 28 hours, suggesting that at least 22 hours of culture is required to reach maximal maturation rate for stored oocytes (43%, 62%, and 65% at 20, 22

  4. Growth temperature and plant age influence on nutritional quality of ...

    African Journals Online (AJOL)

    As a leafy vegetable, Amaranthus can be harvested at different stages of plant growth, ranging from young seedlings to the late juvenile stage, but data on the changes in leaf nutritional value with plant age are scanty. The objective of this study was to determine the effect of growth temperature on Amaranthus leaf yield and ...

  5. Investigation of temperature dependence of development and aging

    Science.gov (United States)

    Sacher, G. A.

    1969-01-01

    Temperature dependence of maturation and metabolic rates in insects, and the failure of vital processes during development were investigated. The paper presented advances the general hypothesis that aging in biological systems is a consequence of the production of entropy concomitant with metabolic activity.

  6. Analysis on High Temperature Aging Property of Self-brazing Aluminum Honeycomb Core at Middle Temperature

    Directory of Open Access Journals (Sweden)

    ZHAO Huan

    2016-11-01

    Full Text Available Tension-shear test was carried out on middle temperature self-brazing aluminum honeycomb cores after high temperature aging by micro mechanical test system, and the microstructure and component of the joints were observed and analyzed using scanning electron microscopy and energy dispersive spectroscopy to study the relationship between brazing seam microstructure, component and high temperature aging properties. Results show that the tensile-shear strength of aluminum honeycomb core joints brazed by 1060 aluminum foil and aluminum composite brazing plate after high temperature aging(200℃/12h, 200℃/24h, 200℃/36h is similar to that of as-welded joints, and the weak part of the joint is the base metal which is near the brazing joint. The observation and analysis of the aluminum honeycomb core microstructure and component show that the component of Zn, Sn at brazing seam is not much affected and no compound phase formed after high temperature aging; therefore, the main reason for good high temperature aging performance of self-brazing aluminum honeycomb core is that no obvious change of brazing seam microstructure and component occurs.

  7. Acetosyringone, pH and temperature effects on transient genetic transformation of immature embryos of Brazilian wheat genotypes by Agrobacterium tumefaciens

    Directory of Open Access Journals (Sweden)

    Ernandes Manfroi

    2015-01-01

    Full Text Available AbstractLow transformation efficiency is one of the main limiting factors in the establishment of genetic transformation of wheat via Agrobacterium tumefaciens. To determine more favorable conditions for T-DNA delivery and explant regeneration after infection, this study investigated combinations of acetosyringone concentration and pH variation in the inoculation and co-cultivation media and co-culture temperatures using immature embryos from two Brazilian genotypes (BR 18 Terena and PF 020037. Based on transient expression of uidA, the most favorable conditions for T-DNA delivery were culture media with pH 5.0 and 5.4 combined with co-culture temperatures of 22 °C and 25 °C, and a 400 μM acetosyringone supplement. These conditions resulted in blue foci in 81% of the embryos. Media with more acidic pH also presented reduced A. tumefaciensovergrowth during co-culture, and improved regeneration frequency of the inoculated explants. BR 18 Terena was more susceptible to infection by A. tumefaciens than PF 020037. We found that it is possible to improve T-DNA delivery and explant regeneration by adjusting factors involved in the early stages of A. tumefaciens infection. This can contribute to establishing a stable transformation procedure in the future.

  8. Embryos, genes, and birth defects

    National Research Council Canada - National Science Library

    Ferretti, Patrizia

    2006-01-01

    ... Structural anomalies The genesis of chromosome abnormalities Embryo survival The cause of high levels of chromosome abnormality in human embryos Relative parental risks - age, translocations, inversions, gonadal and germinal mosaics 33 33 34 35 36 44 44 45 4 Identification and Analysis of Genes Involved in Congenital Malformation Syndromes Peter J. Scambler Ge...

  9. A deterministic simulation study of embryo marker-assisted selection for age at first calving in Nellore (Bos indicus beef cattle

    Directory of Open Access Journals (Sweden)

    Artur J.M. Rosa

    2007-01-01

    Full Text Available We used deterministic simulation of four alternative multiple ovulation and embryo manipulation (MOET closed nucleus schemes to investigate the benefits of using marker-assisted selection (MAS of Nellore (Bos indicus beef cattle embryos prior to transplantation to reduce the age at first calving (AFC. We found that MAS resulted in increased genetic gain as compared to selection without AFC quantitative trait loci (AFC-QTL information. With single-stage selection the genetic response (GR increased as follows: GR = 0.68% when the AFC-QTL explained 0.02 of the AFC additive genetic variance (sigma2A; GR = 1.76% for AFC-QTL explaining 0.05 sigma2A; GR = 3.7% for AFC-QTL explaining 0.1 sigma2A; and GR = 55.76% for AFC-QTL explaining 0.95 sigma2A. At the same total selected proportion, two-stage selection resulted in less genetic gain than single stage MAS at two-years of age. A single stage selection responses of > 95% occurred with pre-selected proportions of 0.4 (0.1 sigma2A explained by AFC-QTL, 0.2 (0.3 sigma2A explained by AFC-QTL and 0.1 (0.5 sigma2A explained by AFC-QTL, indicating that the combined use of MAS and pre-selection can substantially reduce the cost of keeping recipient heifers in MOET breeding schemes. When the number of recipients was kept constant, the benefit of increasing embryo production was greater for the QTL explaining a higher proportion of the additive genetic variance. However this advantage had a diminishing return especially for QTL explaining a small proportion of the additive genetic variance. Thus, marker assisted selection of embryos can be used to achieve increased genetic gain or a similar genetic response at reduced expense by decreasing the number of recipient cows and number of offspring raised to two-years of age.

  10. Foot temperature in healthy individuals: effects of ambient temperature and age.

    Science.gov (United States)

    Nardin, Rachel A; Fogerson, Patricia M; Nie, Rui; Rutkove, Seward B

    2010-01-01

    Patient complaints of excessively warm or cold feet are common in medical practice. Such symptoms can be caused by underlying vascular or neurologic disease, and measurement of foot temperature during daily activity and sleep could provide a deeper understanding of their actual thermal basis. We used a Thermochron iButton to assess surface foot temperature variation and its relationship to ambient temperature during the day with activity and at night during sleep in 39 healthy individuals aged 18 to 65 years in a temperate region of the United States. We simultaneously used actigraphy to record leg movement. We identified a mean +/- SD awake temperature of 30.6 degrees +/- 2.6 degrees C and asleep temperature of 34.0 degrees +/- 1.8 degrees C, with values reaching as low as 15.9 degrees C in the winter and as high as 37.5 degrees C in the summer. Foot temperature was found to be independent of foot movement or sex; however, there was, as expected, a strong association between foot temperature and ambient temperature (r = .59, P sleep. These results provide data on the normal variation of foot temperature in individuals living in a temperate climate and demonstrate the potential use of Thermochron iButton technology in clinical contexts, including the evaluation of patients with excessively warm or cold feet.

  11. Genetic divergence in cellular resistance to heat shock in cattle: differences between breeds developed in temperate versus hot climates in responses of preimplantation embryos, reproductive tract tissues and lymphocytes to increased culture temperatures.

    Science.gov (United States)

    Paula-Lopes, F F; Chase, C C; Al-Katanani, Y M; Krininger, C E; Rivera, R M; Tekin, S; Majewski, A C; Ocon, O M; Olson, T A; Hansen, P J

    2003-02-01

    The detrimental effects of heat stress on fertility in cattle are less pronounced in heat-tolerant breeds. Although these genetic differences reflect differences in thermoregulation, cells from heat-tolerant breeds are less adversely compromised by increased temperature (that is, heat shock) than cells from heat-sensitive breeds. Experiments were performed to test the hypothesis that cells and tissues from two thermotolerant breeds (Brahman and Senepol) are better able to survive and function after exposure to increased temperature than cells and tissues from two thermosensitive breeds (Holstein and Angus). Exposure of embryos at>eight-cell stage at day 5 after insemination to heat shock of 41.0 degrees C for 6 h decreased development to the blastocyst stage and the number of cells per embryo. However, the deleterious effect of heat shock on blastocyst formation and the number of cells per embryo was less pronounced for Brahman than for Holstein and Angus breeds. Embryos from Senepol cows had very low development and it was not possible to determine heat shock effects in this breed. In contrast to the sensitivity of embryos to heat shock, there was no effect of a 41.0 degrees C heat shock on [(3)H]leucine incorporation into proteins secreted by oviductal or endometrial explants. Lymphocytes from Brahman and Senepol cows were more resistant to heat-induced apoptosis than lymphocytes from other breeds. Heat shock reduced lymphocyte glutathione content but the magnitude of the decrease was not affected by breed. In conclusion, embryos from Brahman cows are more resistant to heat shock than embryos from Holstein or Angus cows. Genetic differences are also present in thermotolerance for apoptosis response in lymphocytes, with Brahman and Senepol cattle being more resistant to heat shock than Angus and Holstein breeds. It is likely that the evolutionary forces that led to the Brahman and Senepol breeds being adapted to hot climates resulted in the selection of genes

  12. Carbon monoxide and the embryo.

    Science.gov (United States)

    Robkin, M A

    1997-04-01

    Mammals are homeotherms and expend considerable energy maintaining their body temperatures. The temperature of a mammalian embryo on the other hand is maintained by the mother and the embryo can devote its metabolic energy to growth and development. The mammalian embryo is acting as a poikilotherm and its energy needs are thus considerably less than if it were a comparably sized homeotherm. The energy requirements of the preimplantation rat embryo are generated by anaerobic metabolism. As it grows, aerobic metabolism develops. In culture, the addition of carbon monoxide to the perfusing gas for early rat embryos has a much smaller effect than decreasing the oxygen concentration. Carbon monoxide appears to be a relatively mild toxicant until the embryo is much larger, is depending much more on transport of oxygen by red blood cells, and the fraction of required metabolic energy produced by anaerobic metabolism has become quite small. The effect from smoking during gestation may be either by the concomitant reduction in food intake or a more direct toxic effect from some components in the smoke. Carbon monoxide does not seem to be the culprit. The possible mitigating effect of a compensatory increase in fetal hematocrit in response to any hypoxia must also be considered. Humans have no yolk sac placenta as rodents do, but if the switch from anaerobic to aerobic metabolism is correlated with the stage of development, then carbon monoxide exposure should not represent any significant risk to the human embryo until later in gestation.

  13. Ocular Surface Temperature in Age-Related Macular Degeneration

    Science.gov (United States)

    Sodi, Andrea; Giacomelli, Giovanni; Corvi, Andrea; Menchini, Ugo

    2014-01-01

    Background. The aim of this study is to investigate the ocular thermographic profiles in age-related macular degeneration (AMD) eyes and age-matched controls to detect possible hemodynamic abnormalities, which could be involved in the pathogenesis of the disease. Methods. 32 eyes with early AMD, 37 eyes with atrophic AMD, 30 eyes affected by untreated neovascular AMD, and 43 eyes with fibrotic AMD were included. The control group consisted of 44 healthy eyes. Exclusion criteria were represented by any other ocular diseases other than AMD, tear film abnormalities, systemic cardiovascular abnormalities, diabetes mellitus, and a body temperature higher than 37.5°C. A total of 186 eyes without pupil dilation were investigated by infrared thermography (FLIR A320). The ocular surface temperature (OST) of three ocular points was calculated by means of an image processing technique from the infrared images. Two-sample t-test and one-way analysis of variance (ANOVA) test were used for statistical analyses. Results. ANOVA analyses showed no significant differences among AMD groups (P value >0.272). OST in AMD patients was significantly lower than in controls (P > 0.05). Conclusions. Considering the possible relationship between ocular blood flow and OST, these findings might support the central role of ischemia in the pathogenesis of AMD. PMID:25436140

  14. Ocular Surface Temperature in Age-Related Macular Degeneration

    Directory of Open Access Journals (Sweden)

    Andrea Sodi

    2014-01-01

    Full Text Available Background. The aim of this study is to investigate the ocular thermographic profiles in age-related macular degeneration (AMD eyes and age-matched controls to detect possible hemodynamic abnormalities, which could be involved in the pathogenesis of the disease. Methods. 32 eyes with early AMD, 37 eyes with atrophic AMD, 30 eyes affected by untreated neovascular AMD, and 43 eyes with fibrotic AMD were included. The control group consisted of 44 healthy eyes. Exclusion criteria were represented by any other ocular diseases other than AMD, tear film abnormalities, systemic cardiovascular abnormalities, diabetes mellitus, and a body temperature higher than 37.5°C. A total of 186 eyes without pupil dilation were investigated by infrared thermography (FLIR A320. The ocular surface temperature (OST of three ocular points was calculated by means of an image processing technique from the infrared images. Two-sample t-test and one-way analysis of variance (ANOVA test were used for statistical analyses. Results. ANOVA analyses showed no significant differences among AMD groups (P value >0.272. OST in AMD patients was significantly lower than in controls (P>0.05. Conclusions. Considering the possible relationship between ocular blood flow and OST, these findings might support the central role of ischemia in the pathogenesis of AMD.

  15. Room Temperature Dynamic Strain Aging in Ultrafine-Grained Titanium

    Science.gov (United States)

    Lopes, Felipe Perissé D.; Lu, Chia Hui; Zhao, Shiteng; Monteiro, Sergio N.; Meyers, Marc A.

    2015-10-01

    Dynamic strain aging (DSA) in coarse-grained (CG) titanium is usually observed at intermediate to high temperatures 473 K to 973 K (200 °C to 700 °C) and is characterized by serrations in the stress vs strain curves. In the present work, despite the absence of apparent serrations, ultrafine-grained titanium (UFG Ti) undergoes DSA at room temperature, exhibited through an abnormal increase in the elastic limit and negative strain rate sensitivity. This effect is observed at 293 K (20 °C) in the strain rate interval of 10-4 to 10-2 s-1, and at 203 K (-70 °C) and 373 K (100 °C) in a distinct strain rate range. Based on a calculated activation energy of 17.3 kJ/mol and microstructural observations by transmission electron microscopy, it is proposed that the dominant mechanism for DSA in UFG Ti involves interstitial solutes interacting with dislocations emitted from grain boundaries. The interstitials migrate from the grain boundaries along dislocation lines bowing out as they are emitted from the boundaries, a mechanism with a low calculated activation energy which is comparable with the experimental measurements. The dislocation velocities and interstitial diffusion along the dislocation cores are consistent.

  16. Embryo selection in IVF

    National Research Council Canada - National Science Library

    Mastenbroek, Sebastiaan; van der Veen, Fulco; Aflatoonian, Abbas; Shapiro, Bruce; Bossuyt, Patrick; Repping, Sjoerd

    2011-01-01

    To optimize success rates of IVF, selection of the most viable embryo(s) for transfer has always been essential, as embryos that are cryopreserved are thought to have a reduced chance of implanting after thawing...

  17. Temperature- vs. estrogen-induced sex determination in Caiman latirostris embryos: Both females, but with different expression patterns of key molecules involved in ovarian development.

    Science.gov (United States)

    Canesini, Guillermina; Stoker, Cora; Galoppo, Germán H; Durando, Milena L; Tschopp, María V; Luque, Enrique H; Muñoz-de-Toro, Mónica M; Ramos, Jorge G

    2018-04-01

    Caiman latirostris is a species with temperature dependent sex determination (TSD), which implies that the incubation temperature of the eggs is the main factor that determines the sex during a thermo-sensitive period (TSP). However, estrogens play a critical role in this process. The administration of 17β-estradiol (E 2 ) previous to TSP overrides the effects of male incubation temperature, producing phenotypic females. This effect has been defined as sex reversal or estrogen-induced sex determination (E 2 SD). The aim of the present study is to describe similarities and differences in the effects of TSD and E 2 SD treatment conditions on ovary development. Our results show that the two treatment conditions studied are able to produce different ovaries. Treatment with E 2 modified the expression pattern of estrogen receptor alpha and progesterone receptor, and expression of the enzyme aromatase. Moreover, in E 2 SD females, the proliferation/apoptosis dynamic was also altered and high expression of TAp63 was observed suggesting the presence of greater DNA damage in germ cells. To the best of our knowledge, this is the first report that describes the morphology of the female gonad of C. latirostris in three stages of embryonic development and shows the expression of TAp63 during the gonad development of a reptile. It is important to emphasize that the changes demonstrated in E 2 SD female gonads of embryos show that environmental compounds with proven estrogenic activity alter the follicular dynamics of C. latirostris in neonatal as much as in juvenile animals, endangering their reproductive health and possibly bringing consequences to ecology and evolution. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Ageing and temperature effect on the fatigue performance of bituminous mixtures

    Directory of Open Access Journals (Sweden)

    T. López-Montero

    2017-06-01

    Full Text Available The ageing of asphalt mixes, together with their exposure to low temperatures, causes a progressive increase of cracking. In this paper, the effect of ageing and temperature on the fatigue of asphalt concretes made with two types of binders, conventional (50/70 and polymer modified bitumen (PMB, is studied. For this purpose, specimens previously subjected to an accelerated laboratory ageing process were tested by a strain sweep test at different temperatures (-5ºC, 5ºC and 20°C. Results were compared with the obtained from the unaged specimens showing the relative importance of ageing, temperature and type of bitumen on the parameters that determine the fatigue life of the mixture. The mixtures behaviour becomes more brittle with ageing and the decrease of temperature. However, ageing hardly has an effect on fatigue at lower temperatures. In general, mixtures made with polymer modified bitumen have a better fatigue performance to ageing and temperature.

  19. Holding immature bovine oocytes in a commercial embryo holding medium: High developmental competence for up to 10 h at room temperature.

    Science.gov (United States)

    Pascottini, Osvaldo Bogado; Catteeuw, Maaike; Van Soom, Ann; Opsomer, Geert

    2017-11-04

    Bovine in vitro embryo production (IVP) following Ovum Pick Up (OPU) is all too often hampered by a large time gap between the harvest of oocytes of the first and last OPU session of the day. Immediately after retrieval, oocyte maturation is initiated, resulting in oocytes maturing at different time points which necessitates laborious scheduling of the IVP process. In this study, the potential of a commercial embryo holding medium (EHM; Syngro, Bioniche Inc.) to hold immature bovine oocytes was validated. We assessed the effect of holding time and temperature on (1) oocytes' maturation; (2) blastocyst development and quality at day 8 post insemination; and (3) blastocyst yield in small groups of oocytes/zygotes simulating OPU settings. Oocytes, harvested from slaughterhouse ovaries, were held for 6 h (either at 4 °C, room temperature [RT; 22-25 °C], or 38.5 °C), for 10 h (at 4 °C or RT), and for 14 h (only at RT) in 1 mL sterile glass osmometer tubes filled with EHM prior to standard maturation (22 h at 38.5 °C) and subsequent IVP. Results were compared with controls in which no prior holding was applied. Differences between the treated and control groups were assessed by generalized mixed-effects models and considered significant at P h in EHM at different temperatures remained at the germinal vesicle stage. Holding immature oocytes in EHM for 6 h at 38.5 °C and for 10 h at 4 °C significantly decreased maturation (57.1 ± 4.1% VS 80.9 ± 3.2% and 68.6 ± 3.5% VS 80.7 ± 2.9%; respectively), and development (11.0 ± 1.8% VS 36.2 ± 2.8% and 20.1 ± 3.3% VS 40.6 ± 4.6%) (P h at RT, did not affect the maturation rates (83.2 ± 2.9% and 78.9 ± 3.2%) nor day 8 blastocyst rates (35.2 ± 2.7% and 40.2 ± 4.5%). Prolonging holding time to 14 h in RT decreased maturation and day 8 blastocyst yield (71.9 ± 3.5% VS 84.5 ± 2.7% and 25.7 ± 2.5% VS 39.5 ± 2.8%, respectively) (P h at RT. When subsequently

  20. Modelling fracture of aged graphite bricks under radiation and temperature

    Directory of Open Access Journals (Sweden)

    Atheer Hashim

    2017-05-01

    Full Text Available The graphite bricks of the UK carbon dioxide gas cooled nuclear reactors are subjected to neutron irradiation and radiolytic oxidation during operation which will affect thermal and mechanical material properties and may lead to structural failure. In this paper, an empirical equation is obtained and used to represent the reduction in the thermal conductivity as a result of temperature and neutron dose. A 2D finite element thermal analysis was carried out using Abaqus to obtain temperature distribution across the graphite brick. Although thermal conductivity could be reduced by up to 75% under certain conditions of dose and temperature, analysis has shown that it has no significant effect on the temperature distribution. It was found that the temperature distribution within the graphite brick is non-radial, different from the steady state temperature distribution used in the previous studies [1,2]. To investigate the significance of this non-radial temperature distribution on the failure of graphite bricks, a subsequent mechanical analysis was also carried out with the nodal temperature information obtained from the thermal analysis. To predict the formation of cracks within the brick and the subsequent propagation, a linear traction–separation cohesive model in conjunction with the extended finite element method (XFEM is used. Compared to the analysis with steady state radial temperature distribution, the crack initiation time for the model with non-radial temperature distribution is delayed by almost one year in service, and the maximum crack length is also shorter by around 20%.

  1. Methanol as a cryoprotectant for equine embryos.

    Science.gov (United States)

    Bass, L D; Denniston, D J; Maclellan, L J; McCue, P M; Seidel, G E; Squires, E L

    2004-09-15

    Equine embryos (n=43) were recovered nonsurgically 7-8 days after ovulation and randomly assigned to be cryopreserved in one of two cryoprotectants: 48% (15M) methanol (n=22) or 10% (136 M) glycerol (n=21). Embryos (300-1000 microm) were measured at five intervals after exposure to glycerol (0, 2, 5, 10 and 15 min) or methanol (0, 15, 35, 75 and 10 min) to determine changes (%) in diameter over time (+/-S.D.). Embryos were loaded into 0.25-ml plastic straws, sealed, placed in a programmable cell freezer and cooled from room temperature (22 degrees C) to -6 degrees C. Straws were then seeded, held at -6 degrees C for 10 min and then cooled to -33 degrees C before being plunged into liquid nitrogen. Two or three embryos within a treatment group were thawed and assigned to be either cultured for 12 h prior to transfer or immediately nonsurgically transferred to a single mare. Embryo diameter decreased in all embryos upon initial exposure to cryoprotectant. Embryos in methanol shrank and recovered slightly to 76+/-8 % of their original diameter; however, embryos in glycerol continued to shrink, reaching 57+/-6 % of their original diameter prior to cryopreservation. Survival rates of embryos through Day 16 of pregnancy were 38 and 23%, respectively (P>0.05) for embryos cryopreserved in the presence of glycerol or methanol. There was no difference in pregnancy rates of mares receiving embryos that were cultured prior to transfer or not cultured (P>0.05). Preliminary experiments indicated that 48% methanol was not toxic to fresh equine embryos but methanol provided no advantage over glycerol as a cryoprotectant for equine blastocysts.

  2. Effects of temperature and maternal and grandmaternal age on wing shape in parthenogenetic Drosophila mercatorum

    DEFF Research Database (Denmark)

    Kjaersgaard, Anders; Faurby, Soren; Andersen, Ditte Holm

    2007-01-01

    The effects a stressful developmental temperature and maternal and grandmaternal age was investigated on plasticity of wing shape, using the Procrustes method, in two parthenogenetic strains of Drosophila mercatorum. Shape was significantly modified by both factors. Maternal and grandmaternal age...

  3. A new method to estimate ice age temperatures

    NARCIS (Netherlands)

    Bintanja, R.; Wal, R.S.W. van de; Oerlemans, J.

    2005-01-01

    On glacial time scales, the waxing and waning of the Eurasian and North American ice sheets depend largely on variations in atmospheric temperature. As global sea level is primarily determined by the volume of these ice sheets, there is a direct (yet complex)relation between global sea level and

  4. Effects of Short-Term Aging on Asphalt Binders and Hot Mix Asphalt at Elevated Temperatures and Extended Aging Time

    Directory of Open Access Journals (Sweden)

    Lolly Rubben

    2017-01-01

    Full Text Available The production process of Hot Mix Asphalt (HMA causes a short term aging (STA to asphalt binder due to the heating of both asphalt binder and aggregates before mixing together. Laboratory protocols are followed to simulate the STA conditions for both asphalt binders and asphalt mixtures. STA protocols expose asphalt binders or asphalt mixtures to specific aging temperature for a specific period of time to produce stiffening that is similar to that of actual production conditions. Successful construction of HMA in cold season/regions may require elevating the production temperature of HAM to achieve proper compaction of HMA layers. Producing HMA mixtures at elevated temperatures may cause further increase in the binder stiffness and negatively affect the future field performance of asphalt pavements. This negative affect can be even worse especially if it is coupled with extended exposer time increase. This study aims to investigate effect of elevated production (mixing and STA temperatures and exposure time on the stiffening of binders and asphalt mixtures. The binder experiment involved aging of two Performance Graded (PG binders (PG 76-16 and PG 64-22 at two different temperatures and aging durations. The asphalt mixture experiment involved the STA of asphalt mixtures produced in the laboratory at mixing and STA temperatures 25°F above standard practice and aging time 2 and 4 hours longer than standard practices. The effect of different aging times and temperatures was investigated by running viscosity tests on binders and dynamic modulus |E*| and Indirect Diametrical Strength (IDT tests on asphalt mixtures. The results showed that increasing the mixing and STA temperatures by 25°F seems to have no significant effect on the asphalt mixture properties while doubling the standard STA time seems to have a significant effect on binder and asphalt mixture properties.

  5. Characterization of Al-Mg Alloy Aged at Low Temperatures

    Science.gov (United States)

    Yi, Gaosong; Cullen, David A.; Littrell, Kenneth C.; Golumbfskie, William; Sundberg, Erik; Free, Michael L.

    2017-04-01

    Long-term aged [343 K (70 °C) for 30 months and natural exposure for over 10 years] Al 5456 H116 samples were characterized using electron backscatter diffraction (EBSD), scanning transmission electron microscopy (STEM), state-of-the-art energy-dispersive X-ray spectroscopy (EDS) systems, and small-angle neutron scattering (SANS). ASTM G-67 mass loss tests of the sensitized Al 5456 alloy samples were conducted. Intragranular Mg-rich precipitates, such as Guinier-Preston (GP) zones, were confirmed in Al 5456 H116 aged at 343 K (70 °C) for 30 months, and the volume of these precipitates is 1.39 pct. β' phase is identified at the grain boundary of a navy ship sample, while high-resolution STEM results reveal no intragranular precipitates. Intergranular corrosion (IGC) of Al 5456 was found to be related to the continuity of intergranular precipitates.

  6. Estimation of temperature change and of gas age-ice age difference, 108 kyr B.P., at Vostok, Antarctica

    Science.gov (United States)

    Caillon, N.; Severinghaus, J. P.; Barnola, J.-M.; Chappellaz, J.; Jouzel, J.; Parrenin, F.

    2001-12-01

    Air trapped in ice core bubbles provides our primary source of information about past atmospheres. Air isotopic composition (15N/14N and 40Ar/36Ar) permits an estimate of the temperature shifts associated with abrupt climate changes because of isotope fractionation occurring in response to temperature gradients in the snow layer on top of polar ice sheets. A rapid surface temperature change modifies temporarily the firn temperature gradient, which causes a detectable anomaly in the isotopic composition of nitrogen and argon. The location of this anomaly in depth characterizes the gas age-ice age difference (Δage) during an abrupt event by correlation with the δD (or δ18O) anomaly in the ice. We focus this study on the marine isotope stage 5d/5c transition (108 kyr B.P.), a climate warming which was one of the most abrupt events in the Vostok (Antarctica) ice isotopic record [Petit et al., 1999]. A steplike decrease in δ15N and δ40Ar/4 from 0.49 to 0.47‰ (possibly a gravitational signal due to a change in firn thickness) is preceded by a small but detectable δ15N peak (possibly a thermal diffusion signal). We obtain an estimate of 5350±300 yr for Δage, close to the model estimate of 5000 years obtained using the Vostok glaciological timescale. Our results also suggest that the use of the present-day spatial isotope-temperature relationship slightly underestimates (but by no more than 20±15%) the Vostok temperature change from present day at that time, which is in contrast to the temperature estimate based on borehole temperature measurements in Vostok which suggests that Antarctic temperature changes are underestimated by up to 50% [Salamatin et al, 1998].

  7. influence of a low temperature ageing on the properties of al-6.5%si ...

    African Journals Online (AJOL)

    user

    The effect of a low temperature ageing treatment on the hardness, tensile and corrosion characteristics of sand cast. Al-6.5%Si-0.35%Mg alloy was studied. The temper conditions are low temperature ageing at 90oC, 95oC, 100oCand. 105oC respectively followed by ageing to 180oC for 2 hrs. This was compared with the ...

  8. Temperature-maternal age interactions on wing traits in outbred Drosophila mercatorum

    DEFF Research Database (Denmark)

    Kjaersgaard, Anders; Faurby, Soren; Krag, Kristian

    2010-01-01

    Drosophilid wings have often been used to investigate maternal effects of age and phenotypic plasticity in response to developmental temperature. However, temperature-maternal age interactions have been given little attention despite their potentially important role in driving evolution. Climatic...... change and anthropogenic intervention can possibly influence the age structure of a population, leading to a larger proportion of individuals reproducing at old age due to low recruitment. Here we investigated the morphometric traits wing length and wing width as well as the composite trait wing aspect...... (wing width/wing length) of the offspring of young (3 to 6 d) and old (15 to 18 d) mothers at 3 rearing temperatures (20, 25 and 28 degrees C). We used 2 different strains of highly heterozygous, yet genetically identical, individuals. We found significant effects of maternal age and rearing temperature...

  9. A Model for the Prediction of Tobacco Temperature and Oxygen Profiles in Warehouse Aging Process

    Directory of Open Access Journals (Sweden)

    Zheng Y

    2014-12-01

    Full Text Available A mathematical model on the temperature and oxygen profiles for the tobacco warehouse aging process was formulated and solved by numeric analysis. The model parameters were obtained using the non-linear regression method by fitting several years measured temperatures to the model. The R square value between measured and calculated tobacco temperatures in warehouse aging process are all over 0.95. The proposed model can be used to predict the tobacco hogshead temperature profile at different time and positions with ambient temperature, tobacco moisture contents and pH. At the same time, the model also predicts the oxygen profile in the hogshead. The effects of the ambient temperature, pH, void fraction, the reaction active energy, oxygen diffusivity, and the oxygen consumption rate constant on the temperature profile were studied.

  10. Memory of Multiple Aging Stages above the Freezing Temperature in the Relaxor Ferroelectric PLZT

    Science.gov (United States)

    Cordero, F.; Craciun, F.; Franco, A.; Piazza, D.; Galassi, C.

    2004-08-01

    The dynamic dielectric susceptibility and the elastic compliance of the relaxor ferroelectric lanthanum lead zirconate titanate (PLZT) 9/65/35 have been measured under different cooling and heating protocols in order to study aging and memory. The memory of multiple aging stages at different temperatures has been found (several dips in the susceptibility curves on heating), as in spin glass systems below the glass transition. Remarkably, in PLZT the memory of several aging stages is retained also above the freezing temperature deduced from the dynamic susceptibilities. The results are discussed in light of the existing models of aging and memory in spin and dipolar glasses.

  11. Possible Role of Coryneform Bacteria in Age Gelation of Ultrahigh-Temperature-Processed Milk

    OpenAIRE

    Keogh, Barbara P.; Pettingill, G.

    1982-01-01

    Two strains of psychrotrophic, gram-positive, proteolytic bacteria isolated from raw milk were identified as Arthrobacter or closely related coryneform species. We inoculated raw-milk samples with the strains (one strain per sample) and compared rates of gelation after ultrahigh-temperature processing with that of ultrahigh-temperature-processed controls. The trial indicated that either organism could play a role in age gelation of ultrahigh-temperature-processed milk.

  12. Cryopreservation of preimplantation embryos of cattle, sheep, and goats.

    Science.gov (United States)

    Youngs, Curtis R

    2011-08-05

    Preimplantation embryos from cattle, sheep, and goats may be cryopreserved for short- or long-term storage. Preimplantation embryos consist predominantly of water, and the avoidance of intracellular ice crystal formation during the cryopreservation process is of paramount importance to maintain embryo viability. Embryos are placed into a hypertonic solution (1.4 - 1.5 M) of a cryoprotective agent (CPA) such as ethylene glycol (EG) or glycerol (GLYC) to create an osmotic gradient that facilitates cellular dehydration. After embryos reach osmotic equilibrium in the CPA solution, they are individually loaded in the hypertonic CPA solution into 0.25 ml plastic straws for freezing. Embryos are placed into a controlled rate freezer at a temperature of -6°C. Ice crystal formation is induced in the CPA solution surrounding the embryo, and crystallization causes an increase in the concentration of CPA outside of the embryo, causing further cellular dehydration. Embryos are cooled at a rate of 0.5°C/min, enabling further dehydration, to a temperature of -34°C before being plunged into liquid nitrogen (-196°C). Cryopreserved embryos must be thawed prior to transfer to a recipient (surrogate) female. Straws containing the embryos are removed from the liquid nitrogen dewar, held in room temperature air for 3 to 5 sec, and placed into a 37°C water bath for 25 to 30 sec. Embryos cryopreserved in GLYC are placed into a 1 M solution of sucrose for 10 min for removal of the CPA before transfer to a recipient (surrogate) female. Embryos cryopreserved in EG, however, may be directly transferred to the uterus of a recipient.

  13. Circadian and age-related modulation of thermoreception and temperature regulation: mechanisms and functional implications

    NARCIS (Netherlands)

    Someren, E.J.W. van; Raymann, R.J.E.M.; Scherder, E.J.A.; Daanen, H.A.M.; Swaab, D.F.

    2002-01-01

    At older ages, the circadian rhythm of body temperature shows a decreased amplitude, an advanced phase, and decreased stability. The present review evaluates to what extent these changes may result from age-related deficiencies at several levels of the thermoregulatory system, including

  14. Time-Dependent Behavior of Shrinkage Strain for Early Age Concrete Affected by Temperature Variation

    Directory of Open Access Journals (Sweden)

    Yu Qin

    2017-01-01

    Full Text Available Shrinkage has been proven to be an important property of early age concrete. The shrinkage strain leads to inherent engineering problems, such as cracking and loss of prestress. Atmospheric temperature is an important factor in shrinkage strain. However, current research does not provide much attention to the effect of atmospheric temperature on shrinkage of early age concrete. In this paper, a laboratory study was undertaken to present the time-dependent shrinkage of early age concrete under temperature variation. A newly developed Material Deformation Tester (MDT, which can simulate consecutive variation of atmospheric temperature, was used to collect the shrinkage strain of specimens and temperature data. A numerical model was established to describe the thermoelastic strain of a specimen. The results show that (1 there are several sharp shrinkages up to 600 μ for early age concrete in the first 3 days; (2 the absolute value of shrinkage strain is larger than thermal strain; and (3 the difference of shrinkage strain under temperature variation or constant temperature is up to 500 μ.

  15. Weak temperature dependence of ageing of structural properties in atomistic model glassformers

    Science.gov (United States)

    Jenkinson, Thomas; Crowther, Peter; Turci, Francesco; Royall, C. Patrick

    2017-08-01

    Ageing phenomena are investigated from a structural perspective in two binary Lennard-Jones glassformers, the Kob-Andersen and Wahnström mixtures. In both, the geometric motif assumed by the glassformer upon supercooling, the locally favoured structure (LFS), has been established. The Kob-Andersen mixture forms bicapped square antiprisms; the Wahnström model forms icosahedra. Upon ageing, we find that the structural relaxation time has a time-dependence consistent with a power law. However, the LFS population and potential energy increase and decrease, respectively, in a logarithmic fashion. Remarkably, over the time scales investigated, which correspond to a factor of 104 change in relaxation times, the rate at which these quantities age appears almost independent of temperature. Only at temperatures far below the Vogel-Fulcher-Tamman temperature do the ageing dynamics slow.

  16. Age-related changes of serum mitochondrial uncoupling 1, rumen and rectal temperature in goats.

    Science.gov (United States)

    Arfuso, Francesca; Rizzo, Maria; Giannetto, Claudia; Giudice, Elisabetta; Fazio, Francesco; Piccione, Giuseppe

    2016-07-01

    Thermoregulatory processes are induced not only by exposure to cold or heat but also by a variety of physiological situations including age, fasting and food intake that result in changes in body temperature. The aim of the present study was to evaluate the differences in serum mitochondrial uncoupling protein 1 (UCP1), rumen temperature (TRUMEN) and rectal temperature (TRECTAL) values between adult and kids goats. Ten adult male Maltese goats aged 3-5 years old (Group A) and 30 male kids, raised for meat, were enrolled in this study. The kids were equally divided into 3 groups according to their age: Group B included kids aged 3 months, Group C included kids aged 4 months and Group D included kids aged 5 months. Blood samples and measurements of TRUMEN and TRECTAL were obtained from each animal. One-way repeated measures analysis of variance (ANOVA) was applied to evaluate the effect of age on the studied parameters. Statistically significant higher serum UCP1 levels (Pgoats have good control of body temperature suggesting that further details about the thermogenic capacity and the function of UCP1 in kids and adult goats are worth exploring. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Low Temperature Performance Characteristics of Reclaimed Asphalt Pavement (RAP Mortars with Virgin and Aged Soft Binders

    Directory of Open Access Journals (Sweden)

    Feipeng Xiao

    2017-03-01

    Full Text Available Reclaimed asphalt pavement (RAP has many advantages and is utilized to improve the high temperature properties of asphalt mixtures. Low temperature cracking is a predominant distress in asphalt pavements containing RAP materials. Thus, the evaluation of fracture resistance for asphalt mixtures containing RAP is of interest. The objective of this research is to explore the low temperature performance characteristics of RAP mortars containing sieved RAP and soft binders at three aged states. The stiffness values and m-values from bending beam rheometer (BBR tests at three test temperatures of −18 °C, −12 °C and −6 °C were obtained to conduct the minimum low temperature grades. RAP mortar with a higher aged binder content had a higher minimum low temperature regardless of RAP source. In addition, RAP mortars with virgin soft binder had the best low temperature resistance followed by the RAP mortars with rolling thin film oven (RTFO and pressure-aged vessel (PAV binders.

  18. Effect of Temperature and Age of Concrete on Strength – Porosity Relation

    Directory of Open Access Journals (Sweden)

    T. Zadražil

    2004-01-01

    Full Text Available The compressive strengths of unsealed samples of concrete at the age of 180 days and have been measured at temperatures 20 °C, 300 °C, 600 °C and 900 °C. All of tests were performed for cold material. We compared our results with those obtained in [10] for the same type of concrete (age 28, resp. 90 days and measured at temperature ranging from 20 °C to 280 °C. Dependencies of compressive strength and porosity were correlated together and compared for the samples of age 28, 90 and 180 days. Behaviour of concrete of the age 90, resp. 180 days confirms generally accepted hypothesis that with increasing porosity strength of the concrete decreases. It has to be stressed out, howerer, that concrete samples of the age 28 days exhibit totally opposite dependency. 

  19. Microstructure and nanoindentation analyses of low-temperature aging on the zirconia-porcelain interface.

    Science.gov (United States)

    Peng, M D; Wei, J Q; Wang, Y N; Li, Q

    2017-02-01

    The aim of the present study was to investigate the effects of low-temperature aging on the micro-mechanical and micro-structural properties of zirconia-porcelain interface. In total, thirty-three Y-TZP zirconia blocks were fabricated by using CAD/CAM technology, veneered with porcelains. Specimens were submitted to low-temperature aging in an autoclave at 134°C, additional 0.2MPa pressure for 0h, 5h, or 10h. Flexural strength was obtained by using three-point bending test. Micro-mechanical properties (nano-hardness (H) and reduced modulus (E r )) were investigated by nanoindentation tests. Scanning electron microscopy and X-ray diffraction analyses were performed to identify the micro-structure and fracture behavior. The flexure strength, modulus and hardness of zirconia increased after 5h aging and decreased after 10h aging. No significant alterations of the reduced modulus or hardness of porcelain were detected in the whole aging duration. Width of the zirconia-porcelain interface was extended towards the bulk of zirconia. The detachment and cracks could be observed in zirconia, and the crystal alignment was disorganized in porcelain after 5h aging and 10h aging. Mechanical properties of the veneering porcelain are not affected by low-temperature aging. However, the expansion and the alterations of micro-mechanical and micro-structural properties of zirconia-porcelain interface were detected. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. EVALUATION OF ETHINYLESTRADIOL (EE2 EFFECT ON EMBRYO DEVELOPMENT IN COMMON CARP (CYPRINUS CARPIO

    Directory of Open Access Journals (Sweden)

    GABI DUMITRESCU

    2009-10-01

    Full Text Available Worldwide, the scientific researches performed during the last years are focused on the determination of the negative effects caused by natural and antropogeneous chemical compounds on aquatic species; these species are more exposed to most pollutants than the land species, for the simple reason that the aquatic environment is the last destination for most residues. Our research team proposed to test the toxic effect caused by ethinylestradiol on embryo development in common carp (Cyprinus carpio. Common carp embryos were purchased from the fish farm S.C. Acva Prod S.R.L. Cefa, Bihor County these were obtained by artificial reproduction. After taking and selection, the fecundated spawns were introduced in 10 Nunk culture plates of 45 ml, where we introduced 40 ml water, too. We created 3 batches, with two replications, namely: batch 1 – control, batch 2 – in water, we added ethinylestradiol (EE2 in concentration of 1.5 ng L-1 and batch 3 – we added in water a concentration of 7 ng L-1 EE2. During the incubation, the Nunk plates were kept in breeding aquariums, at a temperature of 24°C. Successive to the supervision of embryos in batch 3, 48 hours post-fecundation, we could observe evolution stagnations, 70% of them being in the stage of 40 somites of the segmentation period. At the same age, 100% of the control batch- embryos entered the stage of advanced faringula, and in batch 2 all embryos were in the stage of incipient faringula. 60-72 hours post-fecundation, all embryos in the batch 3 died, 90% in the 40 somite stage of the segmentation period and 10% in the stage of incipient faringula. 85 hours post-fecundation, all embryos belonging to the control batch were in the larva stage, while in batch 2, 90% were in the larva stage and 10% died in the stage of advanced faringula.

  1. Differences in egg nutrient availability, development, and nutrient metabolism of broiler and layer embryos.

    Science.gov (United States)

    Nangsuay, A; Molenaar, R; Meijerhof, R; van den Anker, I; Heetkamp, M J W; Kemp, B; van den Brand, H

    2015-03-01

    Selection for production traits of broilers and layers leads to physiological differences, which may already be present during incubation. This study aimed to investigate the influence of strain (broiler vs layer) on egg nutrient availability, embryonic development and nutrient metabolism. A total of 480 eggs with an egg weight range of 62.0 to 64.0 g from Lohmann Brown Lite and Ross 308 breeder flocks of 41 or 42 weeks of age were selected in two batches of 120 eggs per batch per strain. For each batch, 30 eggs per strain were used to determine egg composition, including nutrient and energy content, and 90 eggs per strain were separately incubated in one of two climate respiration chambers at an eggshell temperature of 37.8°C. The results showed that broiler eggs had a higher ratio of yolk: albumen with 2.41 g more yolk and 1.48 g less albumen than layers. The yolk energy content of broiler eggs was 46.32 kJ higher than that of layer eggs, whereas total energy content of broiler eggs was 47.85 kJ higher compared to layer eggs. Yolk-free body mass at incubation day 16 and chick weight and length at hatch were higher in broilers compared to layers. Respiration quotient of broiler embryos was higher than layer embryos during incubation day 8 to incubation day 10. A 0.24 g lower residual yolk at the hatch of broiler embryos than for the layer embryos indicated that broiler embryos used more yolk and had a higher energy utilization and energy deposition in yolk-free body mass. Heat production of broiler embryos was higher than that of layer embryos from incubation day 12 to incubation day 18, but efficiency of converting egg energy used by embryos to form yolk-free body mass was similar. In conclusion, broiler and layer embryos have different embryonic development patterns, which affect energy utilization and embryonic heat production. However, the embryos are equal in efficiency of converting the energy used to yolk-free body mass. © 2015 Poultry Science

  2. Motor excitability measurements: the influence of gender, body mass index, age and temperature in healthy controls.

    Science.gov (United States)

    Casanova, I; Diaz, A; Pinto, S; de Carvalho, M

    2014-04-01

    The technique of threshold tracking to test axonal excitability gives information about nodal and internodal ion channel function. We aimed to investigate variability of the motor excitability measurements in healthy controls, taking into account age, gender, body mass index (BMI) and small changes in skin temperature. We examined the left median nerve of 47 healthy controls using the automated threshold-tacking program, QTRAC. Statistical multiple regression analysis was applied to test relationship between nerve excitability measurements and subject variables. Comparisons between genders did not find any significant difference (P>0.2 for all comparisons). Multiple regression analysis showed that motor amplitude decreases with age and temperature, stimulus-response slope decreases with age and BMI, and that accommodation half-time decrease with age and temperature. The changes related to demographic features on TRONDE protocol parameters are small and less important than in conventional nerve conduction studies. Nonetheless, our results underscore the relevance of careful temperature control, and indicate that interpretation of stimulus-response slope and accommodation half-time should take into account age and BMI. In contrast, gender is not of major relevance to axonal threshold findings in motor nerves. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  3. Temperature dependence of direct current conductivity in Ag-ED20 nanocomposite films

    Science.gov (United States)

    Novikov, G. F.; Rabenok, E. V.; Bogdanova, L. M.; Irzhak, V. I.

    2017-10-01

    The effect of silver nanoparticles (NPs) in the concentration range of ≤0.8 wt % have on direct current conductivity σdc of Ag-ED20 nanocomposite is studied by method of broadband dielectric spectroscopy (10-2-105 Hz) method of broadband dielectric spectroscopy. It is found that temperature dependence σdc consists of two sections: above the glass transition temperature ( T g), the dependence corresponds to the empirical Vogel-Fulcher-Tammann law (Vogel temperature T 0 does not depend on the NP concentration); below T g, the dependence is Arrhenius with activation energy E a ≈ 1.2 eV. In the region where T > T g, the σdc value grows along with NP concentration. It is concluded that the observed broken form of the temperature dependence is apparently due to a change in the conduction mechanism after the freezing of ion mobility at temperatures below T g.

  4. Effect of Reinforcement on Early-Age Concrete Temperature Stress: Preliminary Experimental Investigation and Analytical Simulation

    Directory of Open Access Journals (Sweden)

    Jianda Xin

    2015-01-01

    Full Text Available For concrete under short-term loading, effect of reinforcement on concrete crack resistance capability is usually negligible; however, recent research results show that extension of this viewpoint to concrete under long-term loading (temperature variation may be unsuitable. In order to investigate this phenomenon, this paper presents the experimental and analytical results of early-age reinforced concrete temperature stress development under uniaxial restraint. The experiments were carried out on a temperature stress testing machine (TSTM. Experimental results show that the coupling of reinforcement and concrete creep behavior influenced the concrete temperature stress development, and nearly 16% of concrete stress was reduced in the current research. Moreover, the cracking time of reinforced concrete was also delayed. Finally, based on the principle of superposition, analytical simulations of effect of reinforcement on concrete temperature stress have been performed.

  5. Temperature of foods sent by parents of preschool-aged children.

    Science.gov (United States)

    Almansour, Fawaz D; Sweitzer, Sara J; Magness, Allison A; Calloway, Eric E; McAllaster, Michael R; Roberts-Gray, Cynthia R; Hoelscher, Deanna M; Briley, Margaret E

    2011-09-01

    To measure the temperatures of foods in sack lunches of preschool-aged children before consumption at child care centers. All parents of 3- to 5-year-old children in full-time child care at 9 central Texas centers were invited to participate in the study. Foods packed by the parents for lunch were individually removed from the sack and immediately measured with noncontact temperature guns 1.5 hours before food was served to the children. Type of food and number of ice packs in the lunch sack were also recorded. Descriptive analyses were conducted by using SPSS 13.0 for Windows. Lunches, with at least 1 perishable item in each, were assessed from 235 parent-child dyads. Approximately 39% (n = 276) of the 705 lunches analyzed had no ice packs, 45.1% (n = 318) had 1 ice pack, and 88.2% (n = 622) of lunches were at ambient temperatures. Only 1.6% (n = 22) of perishable items (n = 1361) were in the safe temperature zone. Even with multiple ice packs, the majority of lunch items (>90%) were at unsafe temperatures. These results provide initial data on how frequently sack lunches sent by parents of preschool-aged children are kept at unsafe temperatures. Education of parents and the public must be focused on methods of packing lunches that allow the food to remain in the safe temperature zone to prevent foodborne illness.

  6. The Influence of Aging Period, Freezing Temperature and Packaging Material on Frozen Beef Chemical Quality

    Directory of Open Access Journals (Sweden)

    Aris Sri Widati

    2012-04-01

    Full Text Available The objective of the study was to evaluate the influences of aging period, freezing temperature and packaging material on the frozen beef chemical quality. The material of the study was 2-3 years old Ongole grade beef of the Longissimus dorsi part,  and was then classified into 3 treat­ments, namely A (aging periode; 0, 12 and 24 hours, B (freezing temperature; -10°C and -20°C and C (packaging material; aluminum foil (Al, polyprophylene (PP, poly­ethylene (PE and without packaging material. The ob­served variables were water content, crude protein, fat, ash content. The data were analyzed by the Completely Randomized Design (CRD in the Factorial (3x2x4 pattern. The results indicated that the aging periode de­creased the water content, and ash content significantly (P<0.05, and decreased the crude protein but increased the fat content insignificantly. The lower freezing temperature prevented the decreases of the water content, and ash content significantly (P<0.05, but prevented the decrease of crude protein, fat content insignificantly. The packaging material could prevent the decreases of water content, ash content sig­nificantly (P<0.05, but prevent the decreases of protein, and fat content insignificantly. A significant interaction (P<0.05 occured between the freezing temperature and packaging material factors on ash content of the frozen beef. The conclusion was the frozen beef without aging has a high of water content, protein, and ash, but has a low fat content.Temperature at -200C and using aluminium foil packaging can prevent decreasing quality of frozen beef. Keywords : Aging period, freezing temperature,  packaging material

  7. Embryo-maternal communication

    DEFF Research Database (Denmark)

    Østrup, Esben; Hyttel, Poul; Østrup, Olga

    2011-01-01

    Communication during early pregnancy is essential for successful reproduction. In this review we address the beginning of the communication between mother and developing embryo; including morphological and transcriptional changes in the endometrium as well as epigenetic regulation mechanisms...... directing the placentation. An increasing knowledge of the embryo-maternal communication might not only help to improve the fertility of our farm animals but also our understanding of human health and reproduction....

  8. Cryopreservation of canine embryos.

    Science.gov (United States)

    Abe, Yasuyuki; Suwa, Yoshinori; Asano, Tomoyoshi; Ueta, Yoshiko Yanagimoto; Kobayashi, Nanae; Ohshima, Natsumi; Shirasuna, Saori; Abdel-Ghani, Mohammed Ali; Oi, Maya; Kobayashi, Yoshiyasu; Miyoshi, Masafumi; Miyahara, Kazuro; Suzuki, Hiroshi

    2011-02-01

    The assisted reproductive techniques (ARTs) such as in vitro fertilization, embryo transfer, and cryopreservation of gametes have contributed considerably to the development of biomedical sciences in addition to improving infertility treatments in humans as well as the breeding of domestic animals. However, ARTs used in canine species have strictly limited utility when compared with other mammalian species, including humans. Although successful somatic cell cloning has been reported, artificial insemination by frozen semen to date is only available for the improved breeding and reproduction for companion and working dogs as well as guide dogs for the blind. We describe here the successful cryopreservation of embryos and subsequent embryo transfer in dogs. Canine embryos were collected from excised reproductive organs after artificial insemination and subsequently cryopreserved by a vitrification method. When the 4-cell to morula stage of cryopreserved embryos were nonsurgically transferred into the uteri of nine recipient bitches using a cystoscope, five recipients became pregnant and four of them delivered a total of seven pups. The cryopreservation of embryos in canine species will facilitate the transportation and storage of genetic materials and will aid in the elimination of vertically transmitted diseases in dogs. In addition, this technique will contribute to the improved breeding of companion and working dogs such as guide dogs, drug-detecting dogs, and quarantine dogs.

  9. Asphalt Pavement Aging and Temperature Dependent Properties Using Functionally Graded Viscoelastic Model

    Science.gov (United States)

    Dave, Eshan V.

    2009-01-01

    Asphalt concrete pavements are inherently graded viscoelastic structures. Oxidative aging of asphalt binder and temperature cycling due to climatic conditions being the major cause of non-homogeneity. Current pavement analysis and simulation procedures dwell on the use of layered approach to account for these non-homogeneities. The conventional…

  10. Embryo development and embryo transfer in the European mink (Mustela lutreola), an endangered mustelid species.

    Science.gov (United States)

    Amstislavsky, S; Kizilova, E; Ternovskaya, Y; Zudova, G; Lindeberg, H; Aalto, J; Valtonen, M

    2006-01-01

    The European mink is an endangered Mustelidae species and thus requires effective conservation measures, although little is known about reproduction in this species. In particular, preimplantation development has not been studied and, therefore, embryonic development and the growth of embryos was documented in the present study for European mink using light and fluorescent microscopy. Embryos develop in the oviducts and then migrate into the uterus on Day 6 post coitum (p.c.) at the morula stage. Embryos expanded as blastocysts from Day 7 until implantation on Day 12 p.c. Based on these findings, the use of embryo transfer for a conservation programme for the European mink was evaluated. Embryos were flushed from European mink resource females and transferred into the uterine horns of recipient hybrid females (honoriks and nohoriks). These hybrids were obtained by mating European polecat males with European mink females and vice versa. A total of 40 embryos was transferred and 20 live kits were born. The rates of pre- and postnatal survival were 50% and 70%, respectively. Both male and female offspring were lighter at birth in the embryo transfer group compared with naturally born controls, but there was no difference at 3 months of age.

  11. Comparison of influence of ageing on low-temperature characteristics of asphalt mixtures

    Science.gov (United States)

    Vacková, Pavla; Valentin, Jan; Benešová, Lucie

    2017-09-01

    Ability of relaxation of asphalt mixtures and thus its resilience to climate change and traffic load is decreasing by influence of aging - in this case aging of bituminous binder. Binder exposed to climate and UV ages and becomes more fragile and susceptible to damage. The results of the research presented in this paper are aimed to finding a correlation between low-temperature properties of referential and aged asphalt mixture specimens and characteristics (not low-temperature) of bituminous binders. In this research there were used conventional road binders, commonly used modified binders and binders additionally modified in the laboratory. The low-temperature characteristics were determined by strength flexural test, commonly used in the Czech Republic for High Modulus Asphalt Mixtures (TP 151), and semi-cylindrical bending test (EN 12697-44). Both of the tests were extended by specimens exposed to artificial long-term aging (EN 12697-52) - storing at 85° C for 5 days. The results were compared with characteristics of binders for finding a suitable correlation between characteristics of binders and asphalt mixtures.

  12. Embryo manipulation and experimentation.

    Science.gov (United States)

    Warren, M A

    1991-09-01

    I have argued that early human embryos are not human beings, and do not have normal rights. Like human sperm and ova, they are both alive and biologically human. However, they lack the physiological development necessary to sustain a capacity for sentience. If Ford is right, then they are not yet individual human organisms. But the more important point is that their lack of a capacity for sentience makes them inappropriate candidates for the ascription of moral rights. Thus, research on human embryos produced in vitro is not a wrong against them--at least so long as experimentally manipulated embryos are not returned to the womb, or artificially gestated to a stage at which they might become sentient. Some of the more difficult issues about embryo experimentation involve the rights of women as experimental subject and donors. The consent of both male and female gamete donors should normally be required for the production or experimental use of IVF embryos. (Possible exceptions might include cases in which one or both progenitors have died, and the survivor or other responsible family member wished to donate the (frozen) IVF embryos for research or other uses.) However, it is women's rights that are most apt to be endangered, for example, if the large scale therapeutic or commercial use of human embryos leads to a demand for large numbers of ova. Thus, it is vital that researchers and policy-makers heed feminist concerns about embryo research and the new biomedical technologies it may yield. Given adequate information and appropriate procedural protections, women are capable of making autonomous decisions about donating ova or embryos for biomedical research. But regulatory safeguards are needed to ensure against their being coerced, deceived, or manipulated into becoming ovum or embryo donors. As Daniel Callahan has detailed, biomedical technology has reached the point where we can no longer afford to provide everyone with all of the innovative therapies that might

  13. Microstructural evolution of René N4 during high temperature creep and aging

    Directory of Open Access Journals (Sweden)

    Alessandro Giorgetti

    Full Text Available The main scope of this work is to describe the microstructure evolution of single-crystal (SX superalloy René N4 during creep and static aging at high temperatures, in function of time, stress and temperature. During creep at high temperatures, SX microstructure evolves from a dense and ordered distribution of cuboidal γ′ particles to a configuration characterized by alternate rafts of γ′ phase and γ matrix, through a process known as rafting. The microstructural evolution of superalloys is very important to derive models able to predict service conditions of a component through microstructural analysis. In this work two microstructural parameters were identified and analyzed for René N4: matrix channels width w along the [001] lattice direction and periodicity width λ, given by the sum of w and the width of the γ′ precipitates along [001]. Both parameters were measured on some creep-damaged and some statically aged specimens, as well as on the virgin material to analyze their trends in function of time, temperature and stress. In particular, the parameter Δλ looks independent of both the stress level and the microstructural morphology and could be used in future works to develop microstructural evolution model of René N4 in function of service time and temperature. Keywords: Single-crystal, Superalloy, Microstructure, René N4

  14. Room temperature aging to guarantee microbiological safety of Brazilian artisan Canastra cheese

    Directory of Open Access Journals (Sweden)

    Milene Therezinha das Dores

    2013-03-01

    Full Text Available Canastra cheese is one of the oldest and most traditional cheeses made from raw milk in Brazil. However, this type of practice may have severe consequences for human health. According to the current legislation, any cheese made from raw milk must be aged for at least 60 days. Traditionally, Canastra cheese is consumed after different ripening periods, but consumers usually prefer those that are aged less than eight days. This study aimed to evaluate the effects of physicochemical and microbiological parameters, with emphasis on the pathogenic microbiota regulated by law, on cheese aged at room temperature and under refrigeration. Cheese samples were collected from eight different cheese producers located in the Serra da Canastra region twice a year (rainy and dry seasons and analyzed with 8, 15, 22, 29, 36, and 64 days of ripening. Room temperature aging effectively reduced pathogens, reaching the total count established by law in 22 days, regardless of the season. However, ripening under refrigeration, it was ineffective in reducing the Staphylococcus aureus counts to the legislation limits, even after 64 days. Therefore, Canastra cheese should be ripened for at least 22 days at room temperature in order to fulfill the safety regulatory limits.

  15. Is there a relationship between fledge age and nest temperature in Western Bluebirds (Sialia mexicana)?

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Emily Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Thompson, Brent E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hathcock, Charles Dean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-30

    Extensive research has been done on temperature during bird incubation periods, but little has been done during nestling development, and to our knowledge, no studies have been done on Western Bluebird (Sialia mexicana) nestling development. In this study, dataloggers were used to monitor nest temperatures during the nestling development phase of Western Bluebirds to determine if there was a relationship between fledge age and temperature. The study was conducted in an existing nestbox network at Los Alamos National Laboratory and the surrounding area in north-central New Mexico. Based on the age of the nestlings at fledging, the nestboxes (n=65) were split into three groups: early (16 and 17 days old, n=13), average (fledged at or between 18 and 20 days old, n=32), and late (21 days or older, n=20). The temperatures of the early and average (n=45) groups were not significantly different (p=0.32, W=3831000). There was a significant difference in the temperatures between the early and late groups (p=0.000, W=2965600). The early and average groups were then combined, tested against the late group, and were found to be significantly different (p=0.000, W=11315000). Analysis showed a difference within the first seven days post-hatch of 1.42°C between the early/average and late groupings. The results suggest that warmer nest temperatures during the nestling stage may influence the fledge date and may lead to faster fledging. There may be numerous explanations for this, such as a correlation with nestling development, and higher temperatures may allow for faster development. Brood size was non-significant and was not factored into the analysis. Future work should be directed in this area.

  16. Effects of aging temperature on microstructural evolution at dissimilar metal weld interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kyoung Joon; Yoo, Seung Chang; Kim, Taeho [School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Bahn, Chi Bum [School of Mechanical Engineering, Pusan National University (PNU), Busandaehak-ro 63, Beon-gil, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Kim, Ji Hyun, E-mail: kimjh@unist.ac.kr [School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of)

    2015-07-15

    From the earlier study which characterized the region of a fusion boundary between a low-alloy steel (LAS) and a Ni-based weld metal of as-welded and aged samples at 450 °C for a 30-y-equivalent time, it was observed in the microstructure that the aging treatment induced the formation and growth of Cr precipitates in the fusion boundary region because of the thermodynamic driving force. Now, this research extends the text matrix and continues the previous study by compiling all the test data, with an additional aging heat treatment conducted at 400 °C for 15- and 30-y-equivalent times (6450 and 12,911 h, respectively). The results for the extended test matrix primarily represent the common features of and disparities in the effects of thermal aging on the aged samples at two different heat-treatment temperatures (400 and 450 °C). Although no difference was expected between the samples, because the heat treatment conditions simulate thermal aging effects during the same service time of 30 y, the sample aged at 450 °C exhibited slightly more severe effects of thermal aging than the sample aged at 400 °C. Nevertheless, the trends for these effects are similar and the simulation of thermal aging effects for a light-water reactor appears to be reliable. However, according to a simulation of the same degree of thermal aging effects, it appears that the activation energy for Cr diffusion should be larger than the numerical value used in this study.

  17. Effects of aging temperature on microstructural evolution at dissimilar metal weld interfaces

    Science.gov (United States)

    Choi, Kyoung Joon; Yoo, Seung Chang; Kim, Taeho; Bahn, Chi Bum; Kim, Ji Hyun

    2015-07-01

    From the earlier study which characterized the region of a fusion boundary between a low-alloy steel (LAS) and a Ni-based weld metal of as-welded and aged samples at 450 °C for a 30-y-equivalent time, it was observed in the microstructure that the aging treatment induced the formation and growth of Cr precipitates in the fusion boundary region because of the thermodynamic driving force. Now, this research extends the text matrix and continues the previous study by compiling all the test data, with an additional aging heat treatment conducted at 400 °C for 15- and 30-y-equivalent times (6450 and 12,911 h, respectively). The results for the extended test matrix primarily represent the common features of and disparities in the effects of thermal aging on the aged samples at two different heat-treatment temperatures (400 and 450 °C). Although no difference was expected between the samples, because the heat treatment conditions simulate thermal aging effects during the same service time of 30 y, the sample aged at 450 °C exhibited slightly more severe effects of thermal aging than the sample aged at 400 °C. Nevertheless, the trends for these effects are similar and the simulation of thermal aging effects for a light-water reactor appears to be reliable. However, according to a simulation of the same degree of thermal aging effects, it appears that the activation energy for Cr diffusion should be larger than the numerical value used in this study.

  18. Change in the microstructure and mechanical properties of drawn pearlitic steel with low-temperature aging

    Science.gov (United States)

    Hirakami, D.; Ushioda, K.; Manabe, T.; Noguchi, K.; Takai, K.; Hata, Y.; Hata, S.; Nakashima, H.

    2017-07-01

    Hydrogen embrittlement is a serious problem in high-strength steels. Drawn pearlitic steel shows excellent resistance to hydrogen embrittlement despite its high strength, and aging treatment at a low temperature can simultaneously improve its strength and hydrogen-embrittlement resistance. To clarify the mechanism for this we have used thermal desorption analysis (TDA) and the newly developed precession electron diffraction analysis method in the transmission electron microscope. After aging at 100 °C for 10 min, the amount of hydrogen seen amount on the TDA curve reduced at around 100 °C. In contrast, when aging was performed at 300 °C, the hydrogen amount further reduced at around 100 °C and the unevenly deformed lamellar ferrite zone was locally recovered. For the samples that were aged at the low temperature, we confirmed that their yield strength and relaxation stress ratios increased simultaneously with improvement in the hydrogen-embrittlement property. We infer that segregation of carbon or formation of very fine carbide in dislocations during aging is the cause of these behaviors.

  19. Dilemmas encountered with preimplantation diagnosis of aneuploidy in human embryos.

    Science.gov (United States)

    Allan, John; Edirisinghe, Rohini; Anderson, Jasen; Jemmott, Rodney; Nandini, A V; Gattas, Michael

    2004-04-01

    An increased embryo aneuploidy rate is associated with advancing maternal age. Preimplantation genetic diagnosis (PGD) using fluorescence in situ hybridisation (FISH) coupled with in vitro fertilisation (IVF)/embryo biopsy provides a powerful tool to improve the take home baby rates for this poor prognostic group. To report the preliminary findings of a PGD study for aneuploidy screening and to discuss the dilemmas encountered. Preimplantation genetic diagnosis was offered in egg pick up-PGD and frozen embryo transfer-PGD cycles. Embryo biopsy was carried out on day 3 and FISH was used to detect chromosomal abnormalities. The outcome of 75 patients, 100 treatment cycles; 62 egg pick up-PGD and 38 frozen embryo transfer-PGD are presented. The embryo biopsy rate, blastomere survival, presence of nuclei and successful FISH rates for egg pick-up and frozen embryo transfer cycles were similar giving a chromosomal abnormality rate of 57.5 and 51.2% for the respective treatment group. The positive pregnancy, clinical pregnancy and implantation rates were, for egg pick up-PGD 22.7, 13.6 and 21.1% and for frozen embryo transfer-PGD 13.8, 10.3 and 10.0%, respectively. Preimplantation genetic diagnosis coupled with IVF treatment seems to give satisfactory pregnancy rates. The high embryo aneuploidy rates, chromosomal mosaicism and other issues have presented significant ethical and management dilemmas for our physicians and patients alike. These issues highlight the importance of skillful pretreatment counselling for patients considering PGD.

  20. Temperature dependence of the transverse piezoelectric coefficient of thin films and aging effects

    Energy Technology Data Exchange (ETDEWEB)

    Rossel, C., E-mail: rsl@zurich.ibm.com; Sousa, M.; Abel, S.; Caimi, D. [IBM Research—Zurich, CH-8803 Rüschlikon (Switzerland); Suhm, A.; Abergel, J.; Le Rhun, G.; Defay, E. [CEA-LETI, Minatec, 17 rue des Martyrs, F-38054 Grenoble (France)

    2014-01-21

    We present a technique to measure the temperature dependence of the transverse piezoelectric coefficient e{sub 31,f} of thin films of lead zirconate titanate (PZT), aluminum nitride, and BaTiO{sub 3} deposited on Si wafers. It is based on the collection of electric charges induced by the deflection of a Si cantilever coated with the piezoelectric film. The aim of this work is to assess the role of temperature in the decay of the remnant polarization of these materials, in particular, in optimized gradient-free PZT with composition PbZr{sub 0.52}Ti{sub 0.48}O{sub 3}. It is found that in contrast to theoretical predictions, e{sub 31,f} decreases with temperature because of the dominance of relaxation effects. The observation of steps in the logarithmic aging decay law is reminiscent of memory effects seen in frustrated spin glasses.

  1. Strain rate and temperature effects on crack initiation of direct aged 718 Alloy

    OpenAIRE

    Perrais Maxime; Burteau Anthony; Seror Alexandre; Poquillon Dominique; Andrieu Eric

    2014-01-01

    During mechanical tests at high temperature in an oxidizing atmosphere, the effects of strain rate on crack initiation are noticeable. This effect is due to a coupling between local mechanical loading and oxidation. Samples were machined in a turbine disk made of direct aged alloy 718. Tests were performed to understand the effect of these couplings on crack initiation and to ensure lifetime is optimized. This study compared the cracking resistance of two different specimen geometries at a gi...

  2. Ovarian hyperstimulation syndrome and prophylactic human embryo cryopreservation: analysis of reproductive outcome following thawed embryo transfer

    Directory of Open Access Journals (Sweden)

    Sills Eric

    2008-11-01

    Full Text Available Abstract Objective To review utilisation of elective embryo cryopreservation in the expectant management of patients at risk for developing ovarian hyperstimulation syndrome (OHSS, and report on reproductive outcome following transfer of thawed embryos. Materials and methods Medical records were reviewed for patients undergoing IVF from 2000–2008 to identify cases at risk for OHSS where cryopreservation was electively performed on all embryos at the 2 pn stage. Patient age, total number of oocytes retrieved, number of 2 pn embryos cryopreserved, interval between retrieval and thaw/transfer, number (and developmental stage of embryos transferred (ET, and delivery rate after IVF were recorded for all patients. Results From a total of 2892 IVF cycles undertaken during the study period, 51 IVF cases (1.8% were noted where follicle number exceeded 20 and pelvic fluid collection was present. Elective embryo freeze was performed as OHSS prophylaxis in each instance. Mean (± SD age of these patients was 32 ± 3.8 yrs. Average number of oocytes retrieved in this group was 23 ± 8.7, which after fertilisation yielded an average of 14 ± 5.7 embryos cryopreserved per patient. Thaw and ET was performed an average of 115 ± 65 d (range 30–377 d after oocyte retrieval with a mean of 2 ± 0.6 embryos transferred. Grow-out to blastocyst stage was achieved in 88.2% of cases. Delivery/livebirth rate was 33.3% per initiated cycle and 43.6% per transfer. Non-transferred blastocysts remained in cryostorage for 24 of 51 patients (46.1% after ET, with an average of 3 ± 3 blastocysts refrozen per patient. Conclusion OHSS prophylaxis was used in 1.8% of IVF cycles at this institution; no serious OHSS complications were encountered during the study period. Management based on elective 2 pn embryo cryopreservation with subsequent thaw and grow-out to blastocyst stage for transfer did not appear to compromise embryo viability or overall reproductive outcome. For

  3. Influence of coating on nanocrystalline magnetic properties during high temperature thermal ageing

    Energy Technology Data Exchange (ETDEWEB)

    Lekdim, Atef, E-mail: atef.lekdim@univ-lyon1.fr; Morel, Laurent; Raulet, Marie-Ange

    2017-05-15

    Since their birth or mergence the late 1980s, the nanocrystalline ultrasoft magnetic materials are taking a great importance in power electronic systems conception. One of the main advantages that make them more attractive nowadays is their ability to be packaged since the reduction of the magnetostrictive constant to almost zero. In aircraft applications, due to the high component compactness and to their location (for example near the jet engine), the operating temperature increases and may reach easily 200 °C and more. Consequently, the magnetic thermal ageing may occur but is, unfortunately, weakly studied. This paper focuses on the influence of the coating (packaging type) on the magnetic nanocrystalline performances during a thermal ageing. This study is based on monitoring the magnetic characteristics of two types of nanocrystalline cores (naked and coated) during a thermal activated ageing (100, 150 and 200 °C). Based on a dedicated monitoring protocol, a large magnetic characterization has been done and analyzed. Elsewhere, X-Ray Diffraction and magnetostriction measurements were carried out to support the study of the anisotropy energies evolution with ageing. This latter is discussed in this paper to explain and give hypothesis about the ageing phenomena. - Highlights: • The coating impacts drastically the magnetic properties during thermal ageing. • Irreversible ageing phenomena after the total coating breakage. • The deteriorations are related to the storage of the magnetoelastic anisotropy.

  4. The Potential Roles of the G1LEA and G3LEA Proteins in Early Embryo Development and in Response to Low Temperature and High Salinity in Artemia sinica.

    Directory of Open Access Journals (Sweden)

    Wei Zhao

    Full Text Available Late embryogenesis abundant proteins (LEA are stress resistance-related proteins that play crucial roles in protecting against desiccation, cold and high salinity in a variety of animals and plants. However, the expression pattern, distribution and functions of LEA proteins in the post-diapause period of Artemia sinica, and under high salinity and low temperature stresses, remain unknown. In this study, the complete cDNA sequences of the group 1 LEA (As-g1lea and group 3 LEA (As-g3lea genes from A. sinica were cloned. The expression patterns and location of As-G1LEA and As-G1LEA were investigated. The protein abundances of As-G1LEA, As-G3LEA and Trehalase were analyzed during different developmental stages of the embryo and under low temperature and high salinity stresses in A. sinica. The full-length cDNA of As-g1lea was 960 bp, encoding a 182 amino acid protein, and As-g3lea was 2089 bp, encoding a 364 amino acid protein. As-g1lea and As-g3lea showed their highest expressions at 0 h of embryonic development and both showed higher relative expression in embryonic, rather than adult, development stages. The abundances of As-G1LEA, As-G3LEA and trehalose were upregulated under low temperature and downregulated under high salinity stress. These two genes did not show any tissue or organ specific expression. Our results suggested that these LEA proteins might play a pivotal role in stress tolerance in A. sinica.

  5. The First Human Cloned Embryo.

    Science.gov (United States)

    Cibelli, Jose B.; Lanza, Robert P.; West, Michael D.; Ezzell, Carol

    2002-01-01

    Describes a process known as parthenogenesis which produces cloned, early-stage embryos and human embryos generated only from eggs. Speculates that this technology puts therapeutic cloning within reach. (DDR)

  6. Geotropic sensitivity exhibited by single hornets: The influence of caste, age, light and temperature

    Science.gov (United States)

    Ishay, Jacob S.; Rosenzweig, Eyal; Abir, Irit

    Hornet (Vespa orientalis, Hymenoptera: Vespinae) workers, queens and males, aged 0-24 hours (i.e. juveniles) and 24 hours and more (i.e. adults) were tested for their responses to changes in the direction of the gravitational force while placed on a flat surface gradually tilted between 0.5° and 180°. The tests were run on non-blind and blind hornets, at temperatures ranging between 18°C and 35°C, in daylight as well as in the dark. Up to 18 hours of age, negative phototaxis prevailed among the hornets, which displayed a clear preference for remaining in the dark regardless of the geotropic position. Between 18-24 hours of age, there was gradual appearance of a sensitivity to change in the geotropic position. Above 24 hr of age, the hornets became sensitive to changes in their declinations, with workers becoming sensitive at a 3-5° declination, queens at 4-5° and males at a declination of 8-19° from the horizontal. Hornet response takes the form of an upward climb, to the highest point of the test surface. Such response required a temperature exceeding 24.8-25°C for workers, 23.2°C for queens and 20.8-21°C for males.

  7. Direct temperature mass spectrometric study on the depth-dependent compositional gradients of aged triterpenoid varnishes

    Science.gov (United States)

    Theodorakopoulos, Charis; Boon, Jaap J.; Zafiropulos, Vassilis

    2009-07-01

    The depth profiles of aged dammar and mastic films, which were uncovered by optimized KrF excimer laser ablation (248 nm, 25 ns), were examined by direct temperature-resolved mass spectrometry (DTMS). The results establish the generation of depth-dependent compositional gradients in triterpenoid resins as a consequence of aging, for the first time on the molecular level. Electron ionization DTMS total ion currents show that the required temperature to volatilize the polar compounds and the relative amount of pyrolysis products of the high molecular weight condensed fraction is reduced when the upper layer of varying thickness of the films had been removed by the laser. The relative abundance of characteristic ion fragments of known oxidized triterpenoid compounds gradually decreased with depth. In contrast, the ion fragments of original resin molecules became more abundant with depth. The mass spectra of the bulk of the films resembled that of the control samples, which were not subjected to aging. Multivariant factor discriminant analysis quantified the oxidative gradients and showed that a depth of 15 [mu]m from the surface of the aged films is the threshold between highly and much less deteriorated material.

  8. Laser-assisted vitrification of large equine embryos.

    Science.gov (United States)

    Scherzer, J; Davis, C; Hurley, D J

    2011-12-01

    The major difficulty in providing the benefits of embryo cryopreservation for equine agriculture is the mismatch between the optimal embryo age for collection from the mare (7-8 days after ovulation was detected) and the optimal age for freezing under current methods (6.5 days after ovulation). To overcome this limitation, we tested a method to enhance penetration of cryopreservative across the capsule and trophoblast of day 7 and 8 embryos combined with rapid freezing by vitrification. Six small embryos (laser system used to create a small opening in the embryonic capsule and trophectoderm. All embryos were vitrified using a CryoLeaf freezing support. After recovery from freezing and embryo transfer, three of four small untreated embryos (300 μm in diameter, 44%) resulted in a vesicle as detected by ultrasonography approximately one week after transfer. However, only one recipient mare was still pregnant on day 23, and she delivered a live foal. Further investigation is required to determine why most of the embryos in this experiment were lost between day 13 and day 23 of gestation. © 2011 Blackwell Verlag GmbH.

  9. Effects of embryo temperature estimation methodology on the determination of eggshell conductance values in Ross 708 broiler hatching eggs with consideration given to eggshell pigmentation variation.

    Science.gov (United States)

    Olojede, O C; To, S D Filip; McDaniel, C D; Peebles, E D

    2017-09-01

    In a preliminary experiment, the influence of pigment color variation on the temperature readings of the shells (EST) of live embryonated Ross 708 broiler hatching eggs was tested. Prior to set, eggshell color in L*, a*, and b* coordinates were measured at the equator of each egg. Eggshell pigmentation was found not to influence EST from zero through 18 d of incubation (DOI). In a subsequent experiment, EST, as well as air cell (ACT) and cloaca (CLT) temperature measurements were used for the calculation of absolute (GH2O) and specific (gH20) eggshell conductance values for these same types of eggs. An infrared thermometer was used to determine EST from zero to 19 DOI, ACT was measured using a transponder from 12 to 19 DOI, and CLT was determined using a transponder at 4:00 PM at 19 DOI. In the 12 to 19 DOI interval, the values for GH2O as well as for gH20 that were calculated using either EST or ACT were significantly correlated (r ≥ 0.99; P Poultry Science Association Inc.

  10. Ovarian stimulation and embryo quality

    NARCIS (Netherlands)

    Baart, Esther; Macklon, Nick S.; Fauser, Bart J. C. M.

    To Study the effects of different ovarian stimulation approaches on oocyte and embryo quality, it is imperative to assess embryo quality with a reliable and objective method. Embryos rated as high quality by standardized morphological assessment are associated with higher implantation and pregnancy

  11. impact on embryo quality

    Directory of Open Access Journals (Sweden)

    Marijan Tandara

    2013-05-01

    Conclusions: In men with poorer semen quality, evaluated by standard semen parameters, a higher proportion of sperm with damaged DNA can also be expected. Higher sperm DNA damage, established by Halosperm test, also had an impact on embryo quality in this group of patients.

  12. Effects of caffeine, cumulus cell removal and aging on polyspermy and embryo development on in vitro matured and fertilized ovine oocytes.

    Science.gov (United States)

    Maalouf, W E; Lee, J-H; Campbell, K H S

    2009-04-15

    The objectives of these studies were to determine the effects of cumulus cell removal and caffeine treatment on the development of in vitro matured ovine oocytes aged in vitro until until fertilization. Oocytes were denuded (DO) at 24h post-onset of maturation (hpm), control cumulus oocyte complexes (COC's) and DO groups were fertilized at 24 hpm or returned to culture in the presence or absence of 10mM caffeine and fertilized at 30 hpm. Removal of cumulus cells and aging both increased polyspermy, caffeine reduced this increase, however, with the exception of DO's (30 hpm) vs. COC's (24 hpm) the differences were not statistically significant. Aging significantly decreased cleavage between COC groups at 24 hpm and 30 hpm and caffeine did not affect this (68.4%, 73.4%, 74.0% respectively). In contrast, the frequency of cleavage was significantly reduced in the DO (24 hpm) group as compared to COC controls (45.6% vs. 68.4% (P0.05)). In summary caffeine treatment of aged COC's had no significant effect on the frequency of development, however, in aged DO's caffeine treatment statistically increased development to blastocyst and lowered the frequency of polyspermy.

  13. Death of embryos from 2300-year-old quinoa seeds found in an archaeological site.

    Science.gov (United States)

    Burrieza, Hernán Pablo; Sanguinetti, Agustín; Michieli, Catalina Teresa; Bertero, Héctor Daniel; Maldonado, Sara

    2016-12-01

    In the 1970s, during excavations at Los Morrillos, San Juan, Argentina, quinoa seeds were found within ancient pumpkin crocks protected from the light and high temperatures, and preserved in the very dry conditions of the region. The radiocarbon dates confirmed the age of these seeds at around 2300 years. Sectioning of some of these seeds showed reddish-brown embryos, different from the white embryos of recently harvested quinoa seeds. The ancient seeds did not germinate. The structure of the embryo cells was examined using light and transmission electron microscopy; proteins were analyzed by electrophoresis followed by Coomassie blue and periodic acid Schiff staining and fatty acids by gas chromatography. The state of nuclear DNA was investigated by TUNEL assay, DAPI staining, ladder agarose electrophoresis and flow cytometry. Results suggest that, although the embryo tissues contained very low water content, death occurred by a cell death program in which heterochromatin density was dramatically reduced, total DNA was degraded into small fragments of less than 500bp, and some proteins were modified by non-enzymatic glycation, generating Maillard products. Polyunsaturated fatty acids decreased and became fragmented, which could be attributable to the extensive oxidation of the most sensitive species (linolenic and linoleic acids) and associated with a collapse of lipid bodies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Cryopreservation of mouse embryos by ethylene glycol-based vitrification.

    Science.gov (United States)

    Mochida, Keiji; Hasegawa, Ayumi; Taguma, Kyuichi; Yoshiki, Atsushi; Ogura, Atsuo

    2011-11-18

    Cryopreservation of mouse embryos is a technological basis that supports biomedical sciences, because many strains of mice have been produced by genetic modifications and the number is consistently increasing year by year. Its technical development started with slow freezing methods in the 1970s(1), then followed by vitrification methods developed in the late 1980s(2). Generally, the latter technique is advantageous in its quickness, simplicity, and high survivability of recovered embryos. However, the cryoprotectants contained are highly toxic and may affect subsequent embryo development. Therefore, the technique was not applicable to certain strains of mice, even when the solutions are cooled to 4°C to mitigate the toxic effect during embryo handling. At the RIKEN BioResource Center, more than 5000 mouse strains with different genetic backgrounds and phenotypes are maintained(3), and therefore we have optimized a vitrification technique with which we can cryopreserve embryos from many different strains of mice, with the benefits of high embryo survival after vitrifying and thawing (or liquefying, more precisely) at the ambient temperature(4). Here, we present a vitrification method for mouse embryos that has been successfully used at our center. The cryopreservation solution contains ethylene glycol instead of DMSO to minimize the toxicity to embryos(5). It also contains Ficoll and sucrose for prevention of devitrification and osmotic adjustment, respectively. Embryos can be handled at room temperature and transferred into liquid nitrogen within 5 min. Because the original method was optimized for plastic straws as containers, we have slightly modified the protocol for cryotubes, which are more easily accessible in laboratories and more resistant to physical damages. We also describe the procedure of thawing vitrified embryos in detail because it is a critical step for efficient recovery of live mice. These methodologies would be helpful to researchers and

  15. Cryopreservation of Mouse Embryos by Ethylene Glycol-Based Vitrification

    Science.gov (United States)

    Mochida, Keiji; Hasegawa, Ayumi; Taguma, Kyuichi; Yoshiki, Atsushi; Ogura, Atsuo

    2011-01-01

    Cryopreservation of mouse embryos is a technological basis that supports biomedical sciences, because many strains of mice have been produced by genetic modifications and the number is consistently increasing year by year. Its technical development started with slow freezing methods in the 1970s1, then followed by vitrification methods developed in the late 1980s2. Generally, the latter technique is advantageous in its quickness, simplicity, and high survivability of recovered embryos. However, the cryoprotectants contained are highly toxic and may affect subsequent embryo development. Therefore, the technique was not applicable to certain strains of mice, even when the solutions are cooled to 4°C to mitigate the toxic effect during embryo handling. At the RIKEN BioResource Center, more than 5000 mouse strains with different genetic backgrounds and phenotypes are maintained3, and therefore we have optimized a vitrification technique with which we can cryopreserve embryos from many different strains of mice, with the benefits of high embryo survival after vitrifying and thawing (or liquefying, more precisely) at the ambient temperature4. Here, we present a vitrification method for mouse embryos that has been successfully used at our center. The cryopreservation solution contains ethylene glycol instead of DMSO to minimize the toxicity to embryos5. It also contains Ficoll and sucrose for prevention of devitrification and osmotic adjustment, respectively. Embryos can be handled at room temperature and transferred into liquid nitrogen within 5 min. Because the original method was optimized for plastic straws as containers, we have slightly modified the protocol for cryotubes, which are more easily accessible in laboratories and more resistant to physical damages. We also describe the procedure of thawing vitrified embryos in detail because it is a critical step for efficient recovery of live mice. These methodologies would be helpful to researchers and technicians who

  16. Embryo Aggregation in Pig Improves Cloning Efficiency and Embryo Quality.

    Science.gov (United States)

    Buemo, Carla Paola; Gambini, Andrés; Moro, Lucia Natalia; Hiriart, María Inés; Fernández-Martín, Rafael; Collas, Philippe; Salamone, Daniel Felipe

    2016-01-01

    In this study, we analyzed the effects of the cloned embryo aggregation on in vitro embryo development and embryo quality by measuring blastocyst diameter and cell number, DNA fragmentation levels and the expression of genes associated with pluripotency, apoptosis, trophoblast and DNA methylation in the porcine. Zona-free reconstructed cloned embryos were cultured in the well of the well system, placing one (1x non aggregated group) or three (3x group) embryos per microwell. Our results showed that aggregation of three embryos increased blastocyst formation rate and blastocyst diameter of cloned pig embryos. DNA fragmentation levels in 3x aggregated cloned blastocysts were significantly decreased compared to 1x blastocysts. Levels of Oct4, Klf4, Igf2, Bax and Dnmt 1 transcripts were significantly higher in aggregated embryos, whereas Nanog levels were not affected. Transcripts of Cdx2 and Bcl-xl were essentially non-detectable. Our study suggests that embryo aggregation in the porcine may be beneficial for cloned embryo development and embryo quality, through a reduction in apoptotic levels and an improvement in cell reprogramming.

  17. Elevated temperature strength, aging response and creep of aluminum matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, R.B.; Amateau, M.F.; House, M.B.; Meinert, K.C.; Nisson, P. (Pennsylvania State University, State College (United States))

    1992-01-01

    The effect of reinforcement on the high-temperature performance of aluminum matrix composites was investigated using samples of 6061 aluminum alloy reinforced with planar-random graphite fibers, SiC whiskers, or alumina particles, which were aged at 150 and 200 C for up to 500 hrs. As indicated by the results of microhardness tests, all specimens exhibited accelerated aging response, with the response depending on the characteristics of the reinforcement. Both the graphite-fiber- and SiC-whisker-reinforced composites showed a substantially increased strengths over that of the wrought 6061 Al at all temperatures. The graphite-fiber- and the SiC-whisker-reinforced composites were found to retain their tensile strength and stiffness in the overaged condition of the matrix. The whisker-reinforced composite showed significant resistance to creep at temperatures between 232 and 350 C under stresses of up to 100 MPa, while the particulate composite had a moderate increase in creep resistance. 51 refs.

  18. The association between embryo quality and perinatal outcome of singletons born after single embryo transfers: a pilot study.

    Science.gov (United States)

    Oron, Galia; Son, Weon-Young; Buckett, William; Tulandi, Togas; Holzer, Hananel

    2014-07-01

    Does the quality of a single transferred embryo have an effect on the pregnancy outcome? After adjusting for confounding maternal variables, poor embryo quality was not associated with adverse obstetric or perinatal outcome in this small pilot study. Embryo quality is a major predictor of the success of in vitro fertilization treatment and studies have demonstrated a strong association between embryo morphology, implantation and clinical pregnancy rates. However, the association with obstetric and perinatal outcomes has not been evaluated. This single center, retrospective cohort study included 1541 fresh single embryo transfers (SETs) using non-donor oocytes in women ≤40 years between December 2008 and 2012. We compared the cycle outcome and singleton live births resulting from the transfer of a single fresh good quality (Grade 2) embryo with those resulting from the transfer of a single poor quality (fair, Grade 3 or poor, Grade 4) embryo in the cleavage or blastocyst stages. The cycle outcome parameters were biochemical pregnancy and clinical intrauterine pregnancy. The pregnancy outcomes were live birth, miscarriages and stillbirths after 20 weeks of gestation. Among the live births, perinatal outcome parameters included birthweight, small for gestational age, preterm delivery, pre-eclampsia, placental abruption and neonatal complications. Covariates were maternal age, body mass index, smoking status, parity and gender of the baby. There were 1193 good quality SETs and 348 poor quality embryo transfers. SETs performed during the study period resulted in 563 pregnancies and 440 singleton births. There was a higher clinical pregnancy rate (41.5%) and live birth rate (32.3%) in the good quality embryo transfer group compared with that in the poor quality transfer group (19.2 and 15.5%, respectively; P quality embryo. Multivariable logistic regression analyses for pregnancy complications revealed no increased risk of maternal or neonatal complications with the

  19. Improving tribological performance of gray cast iron by laser peening in dynamic strain aging temperature regime

    Science.gov (United States)

    Feng, Xu; Zhou, Jianzhong; Mei, Yufen; Huang, Shu; Sheng, Jie; Zhu, Weili

    2015-09-01

    A high and stable brake disc friction coefficient is needed for automobile safety, while the coefficient degrades due to elevated temperature during the braking process. There is no better solution except changes in material composition and shape design optimization. In the dynamic strain aging(DSA) temperature regime of gray cast iron, micro-dimples with different dimple depth over diameter and surface area density are fabricated on the material surface by laser peening(LP) which is an LST method. Friction behavior and wear mechanism are investigated to evaluate the effects of surface texturing on the tribological performance of specimens under dry conditions. Through LP impacts assisted by DSA, the friction coefficients of the LPed specimens increase noticeably both at room temperature and elevated temperature in comparison to untreated specimens. Moreover, the coefficient of specimen with dimple depth over diameter of 0.03 and surface area density of 30% is up to 0.351 at room temperature, which dramatically rises up to 1.33 times that of untextured specimen and the value is still up to 0.3305 at 400°C with an increasing ratio of 35% compared to that of untreated specimen. The surface of textured specimen shows better wear resistance compared to untreated specimen. Wear mechanism includes adhesive wear, abrasive wear and oxidation wear. It is demonstrated that LP assisted by DSA can substantially improve wear resistance, raise the friction coefficient as well as its stability of gray cast iron under elevated temperatures. Heat fade and premature wear can be effectively relieved by this surface modification method.

  20. Influence of coating on nanocrystalline magnetic properties during high temperature thermal ageing

    Science.gov (United States)

    Lekdim, Atef; Morel, Laurent; Raulet, Marie-Ange

    2017-05-01

    Since their birth or mergence the late 1980s, the nanocrystalline ultrasoft magnetic materials are taking a great importance in power electronic systems conception. One of the main advantages that make them more attractive nowadays is their ability to be packaged since the reduction of the magnetostrictive constant to almost zero. In aircraft applications, due to the high component compactness and to their location (for example near the jet engine), the operating temperature increases and may reach easily 200 °C and more. Consequently, the magnetic thermal ageing may occur but is, unfortunately, weakly studied. This paper focuses on the influence of the coating (packaging type) on the magnetic nanocrystalline performances during a thermal ageing. This study is based on monitoring the magnetic characteristics of two types of nanocrystalline cores (naked and coated) during a thermal activated ageing (100, 150 and 200 °C). Based on a dedicated monitoring protocol, a large magnetic characterization has been done and analyzed. Elsewhere, X-Ray Diffraction and magnetostriction measurements were carried out to support the study of the anisotropy energies evolution with ageing. This latter is discussed in this paper to explain and give hypothesis about the ageing phenomena.

  1. Sex determination of duck embryos: observations on syrinx development

    Science.gov (United States)

    Wilson, Robert E.; Sonsthagen, Sarah A.; Franson, J. Christian

    2013-01-01

    Ducks exhibit sexual dimorphism in vocal anatomy. Asymmetrical ossification of the syrinx (bulla syringealis) is discernable at about 10 days of age in male Pekin duck (Anas platyrhynchos domestica) embryos, but information is lacking on the early development of the bulla in wild ducks. To evaluate the reliability of this characteristic for sexing developing embryos, we examined the syrinx of dead embryos and compared results with molecular sexing techniques in high arctic nesting Common Eiders (Somateria mollissima). Embryos 8 days or older were accurately (100%) sexed based on the presence/absence of a bulla, 2 days earlier than Pekin duck. The use of the tracheal bulla can be a valuable technique when sex identification of embryos or young ducklings is required.

  2. [Effect of environmental temperature, cryopreservation and aging on Plasmodium vivax sporozoites developing into exoerythrocytic stages].

    Science.gov (United States)

    Liu, D; Lou, S; Shu, H; Fu, R; Ye, B

    1995-01-01

    After Anopheles stephensi mosquitoes with salivary infection of Plasmodium vivax were put in environments with temperatures of 30 +/- 1 degrees C, 26 +/- 1 degrees C or 13 +/- 1 degrees C for 5 d, their glands were aseptically dissected and sporozoites were collected and inoculated into HepG2-A16 cell monolayers. Seven days post-inoculation the cultured materials were harvested and the exoerythrocytic schizonts and hypnozoites were observed under the microscope by using immunoperoxidase staining technique. The results showed that the sporozoite developing rate of 30 +/- 1 degrees C group and 13 +/- 1 degrees C group was significantly lower than that of 26 +/- 1 degrees C group (0.33%, 0.35% and 0.75% respectively). The proportion of hypnozoites in the total number of EE forms was the highest in the low temperature group (62.5%) compared with 26 +/- 1 degrees C and 30 +/- 1 degrees C group (40.1% and 42.7% respectively). Suggesting that the low environmental temperature first affected the viability of tachysporozoites or the phenotype of sporozoites and thus resulted in heightened hypnozoite rate. This is parallel to the epidemiological data that in the regions of high latitute vivax malaria with long incubation period was more frequently observed. When the sporozoites within the body of mosquito were cryopreserved at -70 degrees C or in liquid nitrogen for 24 h or 5 d respectively, the proportion of hypnozoite increased 87.4% and 82.4%, respectively. However, cryopreservation did not inactivate all of the tachysporozoites, indicating that the resistance to ultralow temperature in bradysporozoite was much greater than that in tachysporozoites. Aging of sporozoites decreased their developing rate and the exoerythrocytic (EE) schizonts were found to grow sluggishly and asynchronously, indicating that the size of EE schizont and the age of sporozoites are in negative correlation. Meantime, proportion of the hyponozoite decreased significantly.

  3. Manure source and age affect survival of zoonotic pathogens during aerobic composting at sublethal temperatures.

    Science.gov (United States)

    Erickson, Marilyn C; Smith, Chris; Jiang, Xiuping; Flitcroft, Ian D; Doyle, Michael P

    2015-02-01

    Heat is the primary mechanism by which aerobic composting inactivates zoonotic bacterial pathogens residing within animal manures, but at sublethal temperatures, the time necessary to hold the compost materials to ensure pathogen inactivation is uncertain. To determine the influence of the type of nitrogen amendment on inactivation of Salmonella, Listeria monocytogenes, and Escherichia coli O157:H7 in compost mixtures stored at sublethal temperatures, specific variables investigated in these studies included the animal source of the manure, the initial carbon/nitrogen (C:N) ratio of the compost mixture, and the age of the manure. Salmonella and L. monocytogenes were both inactivated more rapidly in chicken and swine compost mixtures stored at 20°C when formulated to an initial C:N ratio of 20:1 compared with 40:1, whereas a C:N ratio did not have an effect on inactivation of these pathogens in cow compost mixtures. Pathogen inactivation was related to the elevated pH of the samples that likely arises from ammonia produced by the indigenous microflora in the compost mixtures. Indigenous microbial activity was reduced when compost mixtures were stored at 30°C and drier conditions (compost mixtures prepared with aged chicken litter compared with fresh chicken litter, whereas E. coli O157:H7 survived to similar extents in compost mixtures prepared with either fresh or aged cow manure. The different responses observed when different sources of manure were used in compost mixtures reveal that guidelines with times required for pathogen inactivation in compost mixtures stored at sublethal temperatures should be dependent on the source of nitrogen, i.e., type of animal manure, present.

  4. Oxidation assisted intergranular cracking under loading at dynamic strain aging temperatures in Inconel 718 superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Rezende, M.C., E-mail: monica_crezende@hotmail.com [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalúrgica e de Materiais, C.P. 68505, Rio de Janeiro 21945-970 (Brazil); Araújo, L.S.; Gabriel, S.B. [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalúrgica e de Materiais, C.P. 68505, Rio de Janeiro 21945-970 (Brazil); Dille, J. [Université Libre de Bruxelles, 4MAT Department, Av. F. Roosevelt 50, C.P. 194/03, Brussels (Belgium); Almeida, L.H. de [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalúrgica e de Materiais, C.P. 68505, Rio de Janeiro 21945-970 (Brazil)

    2015-09-15

    Highlights: • Mechanical properties are controlled by DSA, precipitation hardening and OAIC. • Between 600 and 700 °C the critical strain for serrations increases with temperature. • This is related to the consumption of matrix elements (especially Nb: for γ′ and γ″). • A reduction in ductility occurs (related to the OAIC) when the DSA is no longer effective. • This reduction is accompanied by an increase in intergranular brittle fracture. - Abstract: It is well established that 718 superalloy exhibits brittle intergranular cracking when deformed under tension at temperatures above 600 °C. This embrittlement effect is related with grain boundary penetration by oxygen (Oxygen Assisted Intergranular Cracking – OAIC). Simultaneously, impacting on its mechanical properties, the precipitation of coherent γ′ and γ″ phases occur above 650 °C and Dynamic Strain Aging (DSA) occurs in the temperature range between 200 and 800 °C. Although literature indicates that OAIC is the mechanism that controls mechanical properties at high temperatures, its interactions with DSA and precipitation are still under discussion. The objective of this work is to investigate the interactions between the embrittlement phenomena (OAIC and DSA) and the hardening mechanism of γ′ and γ″ precipitation on the mechanical properties of an annealed 718 superalloy. Tensile tests were performed at a strain rate of 3.2 × 10{sup −4} s{sup −1} under secondary vacuum, in temperatures ranging from 200 to 800 °C. Fracture surfaces were observed by scanning electron microscopy (SEM) and precipitation by transmission electron microscopy (TEM). The effect of DSA and precipitation on the strength and of OAIC on the ductility was verified.

  5. Mixing times towards demographic equilibrium in insect populations with temperature variable age structures.

    Science.gov (United States)

    Damos, Petros

    2015-08-01

    In this study, we use entropy related mixing rate modules to measure the effects of temperature on insect population stability and demographic breakdown. The uncertainty in the age of the mother of a randomly chosen newborn, and how it is moved after a finite act of time steps, is modeled using a stochastic transformation of the Leslie matrix. Age classes are represented as a cycle graph and its transitions towards the stable age distribution are brought forth as an exact Markov chain. The dynamics of divergence, from a non equilibrium state towards equilibrium, are evaluated using the Kolmogorov-Sinai entropy. Moreover, Kullback-Leibler distance is applied as information-theoretic measure to estimate exact mixing times of age transitions probabilities towards equilibrium. Using empirically data, we show that on the initial conditions and simulated projection's trough time, that population entropy can effectively be applied to detect demographic variability towards equilibrium under different temperature conditions. Changes in entropy are correlated with the fluctuations of the insect population decay rates (i.e. demographic stability towards equilibrium). Moreover, shorter mixing times are directly linked to lower entropy rates and vice versa. This may be linked to the properties of the insect model system, which in contrast to warm blooded animals has the ability to greatly change its metabolic and demographic rates. Moreover, population entropy and the related distance measures that are applied, provide a means to measure these rates. The current results and model projections provide clear biological evidence why dynamic population entropy may be useful to measure population stability. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Effect of aging temperature on formation of sol-gel derived fluor-hydroxyapatite nanoparticles.

    Science.gov (United States)

    Joughehdoust, S; Behnamghader, A; Jahandideh, R; Manafi, S

    2010-04-01

    Synthetic hydroxyapatite (HA) has been recognized as one of the most important bone substitute materials in orthopaedics and dentistry over past few decades because of its chemical and biological similarity to the mineral phase of human bone. One solution for reduction the solubility of HA in biological environments is replacing F- by OH in HA structure and forming fluor-hydroxyapatite (FHA) solid solution. In this paper, FHA nanoparticles were successfully synthesized by a sol-gel method. Also, the influence of aging temperature on formation of FHA powder was studied. Equimolar solutions of calcium nitrate tetrahydrate, triethyl phosphite and ammonium fluoride in ethanol were used as Ca, P and F precursors. After aging at different temperatures, the synthesized powders were heat treated at 550 degrees C. The powders were investigated with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), selected area electron diffraction pattern (SAED), energy dispersive analysis of X-ray (EDAX) and zetasizer measurement. The results of XRD proved the presence of fluorapatite (FA) and HA in all samples. In addition, the formation of FHA was confirmed by FT-IR results. XRD studies also showed that the crystallites were in nanometric scale. At the same time, this result was in good agreement with the result of zetasizer analysis.

  7. Glacial age precipitation and temperature estimates for the tropical Guatemalan highlands

    Science.gov (United States)

    Roy, A. J.; Lachniet, M. S.

    2007-12-01

    The Sierra Cuchumatanes of Western Guatemala supported a large ice cap of approximately 44 square km area, and a group of 5-6 small valley glaciers during the local last glacial maximum (LLGM). We propose that a temperature reduction during the Guatemalan LLGM was between -4.5 degrees C and -6.0 degrees C from present accompanied by precipitation totals that fall between 80-100% of present day levels. Our new field work on moraine limits expands upon previous reconnaissance-level studies. Here we present a comprehensive reconstruction of the Guatemalan glacial geomorphology on a high limestone plateau; including delineations between morphologically different moraine sequences, boundaries of sub-glacial till deposits and locations of dry moraine dammed lakes. The glacial geologic map was produced via field mapping and GPS surveying, coupled with aerial photographic analysis. A 50m digital elevation model (DEM) created for the mapping portion was employed as input for a physically based GIS mass-balance model, developed by Plummer and Phillips (2003). The mass-balance model data was calculated for varying precipitation, temperature, environmental lapse rates, cloudiness, wind speed and humidity. A sensitivity analysis using variations in temperature and precipitation provided constraints on Guatemalan highland paleoclimate. Although the ages of the glaciations are unconstrained, a qualitative assessment of moraine morphology suggests correlation with the LLGM (20 - 17.5 ka) moraines of Mexico.

  8. Effect of aging temperature on phase decomposition and mechanical properties in cast duplex stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Mburu, Sarah; Kolli, R. Prakash; Perea, Daniel E.; Schwarm, Samuel C.; Eaton, Arielle; Liu, Jia; Patel, Shiv; Bartrand, Jonah; Ankem, Sreeramamurthy

    2017-04-01

    The microstructure and mechanical properties in unaged and thermally aged (at 280 oC, 320 oC, 360 oC, and 400 oC to 4300 h) CF–3 and CF–8 cast duplex stainless steels (CDSS) are investigated. The unaged CF–8 steel has Cr-rich M23C6 carbides located at the δ–ferrite/γ– austenite heterophase interfaces that were not observed in the CF–3 steel and this corresponds to a difference in mechanical properties. Both unaged steels exhibit incipient spinodal decomposition into Fe-rich α–domains and Cr-rich α’–domains. During aging, spinodal decomposition progresses and the mean wavelength (MW) and mean amplitude (MA) of the compositional fluctuations increase as a function of aging temperature. Additionally, G–phase precipitates form between the spinodal decomposition domains in CF–3 at 360 oC and 400 oC and in CF–8 at 400 oC. The microstructural evolution is correlated to changes in mechanical properties.

  9. Age- and temperature-dependent somatic mutation accumulation in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Ana Maria Garcia

    2010-05-01

    Full Text Available Using a transgenic mouse model harboring a mutation reporter gene that can be efficiently recovered from genomic DNA, we previously demonstrated that mutations accumulate in aging mice in a tissue-specific manner. Applying a recently developed, similar reporter-based assay in Drosophila melanogaster, we now show that the mutation frequency at the lacZ locus in somatic tissue of flies is about three times as high as in mouse tissues, with a much higher fraction of large genome rearrangements. Similar to mice, somatic mutations in the fly also accumulate as a function of age, but they do so much more quickly at higher temperature, a condition which in invertebrates is associated with decreased life span. Most mutations were found to accumulate in the thorax and less in abdomen, suggesting the highly oxidative flight muscles as a possible source of genotoxic stress. These results show that somatic mutation loads in short-lived flies are much more severe than in the much longer-lived mice, with the mutation rate in flies proportional to biological rather than chronological aging.

  10. Relationship of age and body mass index to skin temperature and skin perfusion in primary Raynaud's phenomenon.

    Science.gov (United States)

    Giurgea, Georgiana-Aura; Mlekusch, Wolfgang; Charwat-Resl, Silvia; Mueller, Markus; Hammer, Alexandra; Gschwandtner, Michael E; Koppensteiner, Renate; Schlager, Oliver

    2015-01-01

    To assess the relationship of age and body mass index (BMI) to skin temperature and perfusion in patients with primary Raynaud's phenomenon (RP) compared with controls. Patients with RP as well as age- and sex-matched controls underwent external cold provocation by exposure to 20 °C water for 1 minute. Before and after cold provocation, skin temperature and skin perfusion were measured. Twenty-six patients with RP (20 women and 6 men; median age 41.9 years) and 22 controls (17 women and 5 men; median age 42.9 years) were studied. In RP patients, cold exposure led to a median change in skin temperature of -7% (interquartile range [IQR] -13.1, -4.1) and to a median change in skin perfusion of -26.4% (IQR -36.2, 2.9). In controls, skin temperature changed by -15.7% (IQR -18.3, -11.6) and skin perfusion by -33% (IQR -53.3, -1.1) upon cold exposure. In patients with RP, age and BMI were related to skin temperature (for age, r = 0.683, P skin perfusion (for age, r = 0.595, P = 0.002; for BMI, r = 0.653, P skin temperature was inversely related to age (r = -0.518, P = 0.003) and BMI (r = -0.662, P skin perfusion was not related to age or BMI in either group. The cold-induced decrease in skin temperature is related to age and BMI in patients with RP but not in controls. Further studies are needed to clarify the pathophysiology of digital ischemia in primary RP. Copyright © 2015 by the American College of Rheumatology.

  11. Gender determination of avian embryo

    Energy Technology Data Exchange (ETDEWEB)

    Daum, Keith A. (Idaho Falls, ID); Atkinson, David A. (Idaho Falls, ID)

    2002-01-01

    Disclosed is a method for gender determination of avian embryos. During the embryo incubation process, the outer hard shells of eggs are drilled and samples of allantoic fluid are removed. The allantoic fluids are directly introduced into an ion mobility spectrometer (IMS) for analysis. The resulting spectra contain the relevant marker peaks in the positive or negative mode which correlate with unique mobilities which are sex-specific. This way, the gender of the embryo can be determined.

  12. embryos subjected to different drying temperatures

    African Journals Online (AJOL)

    CERRADONLINE

    2012-06-07

    Jun 7, 2012 ... Bra. Sem., 9: 109-114. Ferreira SAN, Santos LA (1993). Efeito da velocidade de secagem sobre a emergência e vigor de sementes de pupunha. Acta Amaz.,. 23: 3-8. Hu CY, Ferreira AG (1998). Cultura de embriões. In: Torres AC, Caldas. LS, Buso JA (Ed.). Cultura de tecidos e transformação genética de.

  13. Temperature- and age-dependent survival, development, and oviposition rates of the pupal parasitoid Spalangia cameroni (Hymenoptera: Pteromalidae)

    DEFF Research Database (Denmark)

    Skovgård, Henrik; Nachman, Gösta

    2016-01-01

    The combined effect of temperature and age on development, survival, attack rate, and oviposition of the parasitoid Spalangia cameroni (Perkins) (Hymenoptera: Pteromalidae) exploiting house fly pupae was investigated by conducting life-table experiments at 15, 20, 25, 30 and 35°C. Temperature had...

  14. Dynamic strain aging in the high-temperature low-cycle fatigue of SA508 Cl. 3 forging steel

    Science.gov (United States)

    Lee, Byung Ho; Kim, In Sup

    1995-10-01

    The effect of dynamic strain aging on cyclic stress response and fatigue resistance of ASME SA508 Cl.3 forging steel for nuclear reactor pressure vessels has been evaluated in the temperature range of room temperature to 500°C. Total strain ranges and strain rates were varied from 0.7 to 2.0% and from 4 × 10 -4 to 1 × 10 -2 s -1, respectively. The cyclic stress response depended on the testing temperature, strain rate, and range. Generally, the initial cyclic hardening was immediately followed by cyclic softening at all strain rates. However, at 300°C, the operating temperature of nuclear reactor pressure vessels, the variation of cyclic stress amplitude showed the primary and secondary hardening stages dependent on the strain rate and strain range. Dynamic strain aging was manifested by enhanced cyclic hardening, distinguished secondary hardening, and negative strain rate sensitivity. A modified cell shutting model was described for the onset of the secondary hardening due to the dynamic strain aging and it was in good agreement with the experimental results. Fatigue life increased in strain rate at all testing temperatures. Specifically the fatigue life was longer at the dynamic strain aging temperature. Further, the dynamic strain aging was easy to initiate the crack, while crack propagation was retarded by crack branching and suppression of plastic zone, hence the dynamic strain aging caused the improvement of fatigue resistance.

  15. Embryo quality is the main factor affecting cumulative live birth rate after elective single embryo transfer in fresh stimulation cycles.

    Science.gov (United States)

    Niinimäki, Maarit; Veleva, Zdravka; Martikainen, Hannu

    2015-11-01

    The study was aimed to evaluate which factors affect the cumulative live birth rate after elective single embryo transfer in women younger than 36 years. Additionally, number of children in women with more than one delivery per ovum pick-up after fresh elective single embryo transfer and subsequent frozen embryo transfers was assessed. Retrospective cohort study analysing data of a university hospital's infertility clinic in 2001-2010. A total of 739 IVF/ICSI cycles with elective single embryo transfer were included. Analyses were made per ovum pick-up including fresh and subsequent frozen embryo transfers. Factors affecting cumulative live birth rates were examined in uni- and multivariate analyses. A secondary endpoint was the number of children born after all treatments. In the fresh cycles, the live birth rate was 29.2% and the cumulative live birth rate was 51.3%, with a twin rate of 3.4%. In the multivariate analysis, having two (odds ratio (OR) 1.73; 95% confidence interval (CI) 1.12-2.67) or ≥3 top embryos (OR 2.66; 95% CI 1.79-3.95) was associated with higher odds for live birth after fresh and frozen embryo cycles. Age, body mass index, duration of infertility, diagnosis or total gonadotropin dose were not associated with the cumulative live birth rate. In cycles with one top embryo, the cumulative live birth rate was 40.2%, whereas it was 64.1% in those with at least three top embryos. Of women who had a live birth in the fresh cycle, 20.4% had more than one child after all frozen embryo transfers. Among women with three or more top embryos after ovum pick-up, 16.1% gave birth to more than one child. The cumulative live birth rate in this age group varies from 40% to 64% and is dependent on the quality of embryos. Women with three or more top embryos have good chance of having more than one child per ovum pick-up without elevated risk of multiple pregnancies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  16. Effects of Operating Temperatures and Accelerated Environmental Ageing on the Mechanical Properties of a Glass-Vinylester Composite

    Science.gov (United States)

    Klasztorny, M.; Nycz, D. B.; Romanowski, R. K.; Gotowicki, P.; Kiczko, A.; Rudnik, D.

    2017-07-01

    Experimental identification of the mechanical properties of a selected glass-vinylester structural composite is developed, performed, and analysed taking into account accelerated environmental ageing and three operating temperatures (-20, 20, and 55°C) corresponding to the operating temperature range for composite footbridges in the Central Europe. The main constituents of the composite fabricated using infusion technology are a bidirectional balanced stitched E-glass fabric and a flame retardant, vinylester resin. After homogenization, the composite reinforced with one fabric forms a single lamina and is modeled as a linear elastic-brittle orthotropic material. Full sets of material constants were identified for the initial and aged composites at the selected operating temperatures. The accelerated environmental ageing of the composite was performed on 4-layer symmetric laminate platelets protected with a 300-mm-thick gelcoat layer, using an ageing chamber and a relevant ageing programme. A comparative analysis was carried out in order to determine the effects of operating temperature and accelerated environmental ageing on the material constants of the GFRP composite. It is found that the composite tested can be modeled as a linear elastic-brittle orthotropic material to the level of 20% of its strength in each strength test. The impact of the accelerated environmental ageing and operating temperature in the range from -20 to 55°C on the elastic/strength/ultimate strain constants of the selected E-glass/vinylester composite can be significant and different for individual constants.

  17. Effects of aging temperature on electrical conductivity and hardness of Cu-3 at. pct Ti alloy aged in a hydrogen atmosphere

    KAUST Repository

    Semboshi, S.

    2011-08-01

    To improve the balance of the electrical conductivity and mechanical strength for dilute Cu-Ti alloys by aging in a hydrogen atmosphere, the influence of aging temperature ranging from 673 K to 773 K (400 °C to 500 °C) on the properties of Cu-3 at. pct Ti alloy was studied. The Vickers hardness increases steadily with aging time and starts to fall at 3 hours at 773 K (500 °C), 10 hours at 723 K (450 °C), or over 620 hours at 673 K (400 °C), which is the same as the case of conventional aging in vacuum. The maximum hardness increases from 220 to 236 with the decrease of aging temperature, which is slightly lower than aging at the same temperature in vacuum. The electrical conductivity at the maximum hardness also increases from 18 to 32 pct of pure copper with the decrease of the temperature, which is enhanced by a factor of 1.3 to 1.5 in comparison to aging in vacuum. Thus, aging at 673 K (400 °C) in a hydrogen atmosphere renders fairly good balance of strength and conductivity, although it takes nearly a month to achieve. The microstructural changes during aging were examined by transmission electron microscopy (TEM) and atom-probe tomography (APT), it was confirmed that precipitation of the Cu4Ti phase occurs first and then particles of TiH2 form as the third phase, thereby efficiently removing the Ti solutes in the matrix.

  18. Desiccation and Cold Hardening of Date Palm Somatic Embryos Improve Germination.

    Science.gov (United States)

    Shareef, Hussein J

    2017-01-01

    Embryogenic suspension cultures of date palm are ideal for mass propagation of somatic embryos; however, the low percentage of germination of somatic embryos (SE) remains an impediment. This chapter focuses on two important physical factors to improve germination of date palm somatic embryos: the use of partial desiccation (3 h) of somatic embryos and the exposure to low temperature (4 °C for 24 h). High germination percentage (41%) is achieved by desiccation for 3 h. Moreover, adding 0.3 g/L activated charcoal (AC) to the liquid medium further improves somatic embryo number and weight as well as the percentage of germination. Moreover, partial desiccation and low temperature exposure tend to increase proline content. This improved protocol for somatic embryo germination is potentially applicable for commercial micropropagation of date palm.

  19. Who abandons embryos after IVF?

    LENUS (Irish Health Repository)

    Walsh, A P H

    2010-04-01

    This investigation describes features of in vitro fertilisation (IVF) patients who never returned to claim their embryos following cryopreservation. Frozen embryo data were reviewed to establish communication patterns between patient and clinic; embryos were considered abandoned when 1) an IVF patient with frozen embryo\\/s stored at our facility failed to make contact with our clinic for > 2 yrs and 2) the patient could not be located after a multi-modal outreach effort was undertaken. For these patients, telephone numbers had been disconnected and no forwarding address was available. Patient, spouse and emergency family contact\\/s all escaped detection efforts despite an exhaustive public database search including death records and Internet directory portals. From 3244 IVF cycles completed from 2000 to 2008, > or = 1 embryo was frozen in 1159 cases (35.7%). Those without correspondence for > 2 yrs accounted for 292 (25.2%) patients with frozen embryos; 281 were contacted by methods including registered (signature involving abandoned embryos did not differ substantially from other patients. The goal of having a baby was achieved by 10\\/11 patients either by spontaneous conception, adoption or IVF. One patient moved away with conception status unconfirmed. The overall rate of embryo abandonment was 11\\/1159 (< 1%) in this IVF population. Pre-IVF counselling minimises, but does not totally eliminate, the problem of abandoned embryos. As the number of abandoned embryos from IVF accumulates, their fate urgently requires clarification. We propose that clinicians develop a policy consistent with relevant Irish Constitutional provisions to address this medical dilemma.

  20. The assessment of the age of scleractinian coral species (Anthozoa: Scleractinia) based on the temperature ranges of their habitat

    Science.gov (United States)

    Os'kina, N. S.; Keller, N. B.; Nikolaev, S. D.

    2010-12-01

    Until now, the age of deep-water scleractinians was determined based only on rare finds of these corals in terrestrial sequences, which constitute <10% of their known diversity. Inasmuch as most of the non-zooxanthellate coral species dwell in the ocean beyond the shelf zone (up to the abyssal depths) and their fossil remains are missing from terrestrial sections, we propose a new approach to the assessment of their age based on paleoecological features: the seawater temperatures in the geological past and the habitat temperature ranges established for 53 coral species. The study confirmed our previous assumption concerning the very young age of the deep-water fauna.

  1. Microstructure and high temperature stability of age hardenable AA2219 aluminium alloy modified by Sc, Mg and Zr additions

    Energy Technology Data Exchange (ETDEWEB)

    Naga Raju, P. [Metallurgical and Materials Engineering Department, IIT-Madras, Chennai 600036 (India)], E-mail: puvvala_nagaraju@yahoo.com; Srinivasa Rao, K. [Metallurgical Engineering Department, Andhra University, Visakapatnam 530003 (India); Reddy, G.M. [Defence Metallurgical Research Laboratory, Hyderabad 500258 (India); Kamaraj, M.; Prasad Rao, K. [Metallurgical and Materials Engineering Department, IIT-Madras, Chennai 600036 (India)

    2007-08-25

    The present work pertains to the improvement of high temperature stability of age hardenable AA2219 aluminium-copper (6.3%) alloy. Addition of scandium, magnesium and zirconium to the base metal AA2219 was adopted to improve this high temperature stability. These additions were systematically varied by preparing alloys of different composition using gas tungsten arc melting. Long time ageing studies and impression creep technique were used to study the high temperature stability of the alloys. These modified compositions of the alloy resulted in fine equiaxed grains, refined eutectics, large number of high temperature stable and finer precipitates. Among all the compositions, 0.8% Sc + 0.45% Mg + 0.2% Zr addition was found to be significant in improving the high temperature stability of AA2219 alloy. This may be attributed to the possible microstructural changes, solute enrichment of the matrix and pinning of the grain boundaries by the finer precipitates.

  2. Hydra, the everlasting embryo, confronts aging.

    Science.gov (United States)

    Martínez, Daniel E; Bridge, Diane

    2012-01-01

    Existing data imply that the cnidarian Hydra vulgaris does not undergo senescence. In contrast, the related species Hydra oligactis shows increased mortality and physiological deterioration following sexual reproduction. Hydra thus offers the chance to study a striking difference in lifespan in members of the same genus. Adult Hydra possess three well-characterized stem cell populations, one of which gives rise to both somatic cells and gametes. The lack of senescence in Hydra vulgaris raises the question of how these stem cell populations are maintained over long periods of time. Investigation of the roles in Hydra of proteins involved in cellular stress responses in other organisms should provide insight into this issue. Proteins of particular interest include the Hsp70 family proteins and the transcription factor FoxO.

  3. Associations between changes in city and address specific temperature and QT interval--the VA Normative Aging Study.

    Directory of Open Access Journals (Sweden)

    Amar J Mehta

    Full Text Available BACKGROUND: The underlying mechanisms of the association between ambient temperature and cardiovascular morbidity and mortality are not well understood, particularly for daily temperature variability. We evaluated if daily mean temperature and standard deviation of temperature was associated with heart rate-corrected QT interval (QTc duration, a marker of ventricular repolarization in a prospective cohort of older men. METHODS: This longitudinal analysis included 487 older men participating in the VA Normative Aging Study with up to three visits between 2000-2008 (n = 743. We analyzed associations between QTc and moving averages (1-7, 14, 21, and 28 days of the 24-hour mean and standard deviation of temperature as measured from a local weather monitor, and the 24-hour mean temperature estimated from a spatiotemporal prediction model, in time-varying linear mixed-effect regression. Effect modification by season, diabetes, coronary heart disease, obesity, and age was also evaluated. RESULTS: Higher mean temperature as measured from the local monitor, and estimated from the prediction model, was associated with longer QTc at moving averages of 21 and 28 days. Increased 24-hr standard deviation of temperature was associated with longer QTc at moving averages from 4 and up to 28 days; a 1.9°C interquartile range increase in 4-day moving average standard deviation of temperature was associated with a 2.8 msec (95%CI: 0.4, 5.2 longer QTc. Associations between 24-hr standard deviation of temperature and QTc were stronger in colder months, and in participants with diabetes and coronary heart disease. CONCLUSION/SIGNIFICANCE: In this sample of older men, elevated mean temperature was associated with longer QTc, and increased variability of temperature was associated with longer QTc, particularly during colder months and among individuals with diabetes and coronary heart disease. These findings may offer insight of an important underlying mechanism of

  4. Assessing the relationship between global warming and mortality: Lag effects of temperature fluctuations by age and mortality categories

    Energy Technology Data Exchange (ETDEWEB)

    Yu Weiwei, E-mail: weiwei.yu@qut.edu.au [School of Public Health and Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD 4050, Brisbane (Australia); Mengersen, Kerrie [Discipline of Mathematical Sciences, Faculty of Science and Technology, Queensland University of Technology, Brisbane (Australia); Hu Wenbiao [School of Population Health and Institute of Health and Biomedical Innovation, University of Queensland, Brisbane (Australia); Guo Yuming [School of Public Health and Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD 4050, Brisbane (Australia); Pan Xiaochuan [School of Public Health, Peking University, Beijing 100191 (China); Tong Shilu, E-mail: s.tong@qut.edu.au [School of Public Health and Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD 4050, Brisbane (Australia)

    2011-07-15

    Although interests in assessing the relationship between temperature and mortality have arisen due to climate change, relatively few data are available on lag structure of temperature-mortality relationship, particularly in the Southern Hemisphere. This study identified the lag effects of mean temperature on mortality among age groups and death categories using polynomial distributed lag models in Brisbane, Australia, a subtropical city, 1996-2004. For a 1 deg. C increase above the threshold, the highest percent increase in mortality on the current day occurred among people over 85 years (7.2% (95% CI: 4.3%, 10.2%)). The effect estimates among cardiovascular deaths were higher than those among all-cause mortality. For a 1 deg. C decrease below the threshold, the percent increases in mortality at 21 lag days were 3.9% (95% CI: 1.9%, 6.0%) and 3.4% (95% CI: 0.9%, 6.0%) for people aged over 85 years and with cardiovascular diseases, respectively. These findings may have implications for developing intervention strategies to reduce and prevent temperature-related mortality. - Highlights: > A longer lag effects in cold days and shorter lag effects in hot days. > The very old people were most vulnerable to temperature stress. > The cardiovascular mortality was also sensitive to the temperature variation. - In Brisbane, the lag effects lasted longer for cold temperatures, and shorter for hot temperatures. Elderly people and cardiovascular mortality were vulnerable to temperature stress.

  5. Strain rate and temperature effects on crack initiation of direct aged 718 Alloy

    Directory of Open Access Journals (Sweden)

    Perrais Maxime

    2014-01-01

    Full Text Available During mechanical tests at high temperature in an oxidizing atmosphere, the effects of strain rate on crack initiation are noticeable. This effect is due to a coupling between local mechanical loading and oxidation. Samples were machined in a turbine disk made of direct aged alloy 718. Tests were performed to understand the effect of these couplings on crack initiation and to ensure lifetime is optimized. This study compared the cracking resistance of two different specimen geometries at a given plastic strain and performed quantitative measurement of the mechanical loading conditions inducing crack initiation between 600 ∘C and 650 ∘C. Sample geometries consisted in tensile flat specimens and V-shaped samples. This specific geometry was used to localize strain and damage in the apex of the V and to reach strain rates lower than those possible on standard specimens. Digital image correlation technique was used to provide strain measurements. For each temperature and strain rate, finite element calculations using the identified constitutive law were performed to get a refined level of strain in different areas at the V apex. Tests were stopped after an imposed displacement corresponding to a given plastic strain distribution. SEM observations of the surface of the flat tensile samples revealed no crack initiation. On the contrary, SEM observations at the apex of V specimens for which the level of cumulative strain was close to the level of cumulative strain of flat samples reveal the presence of intergranular damage when the strain rate used was below a given level.

  6. Transformation behavior and shape memory properties of Ti{sub 50}Ni{sub 15}Pd{sub 25}Cu{sub 10} high temperature shape memory alloy at various aging temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Rehman, Saif ur, E-mail: saifur.rehman@smme.nust.edu.pk [School of Mechanical and Manufacturing Engineering, National University of Science and Technology, Islamabad (Pakistan); Khan, Mushtaq [School of Mechanical and Manufacturing Engineering, National University of Science and Technology, Islamabad (Pakistan); Nusair Khan, A.; Ali, Liaqat; Zaman, Sabah; Waseem, Muhammad [Institute of Industrial Control System, Rawalpindi (Pakistan); Ali, Liaqat; Jaffery, Syed Husain Imran [School of Mechanical and Manufacturing Engineering, National University of Science and Technology, Islamabad (Pakistan)

    2014-12-01

    This research presents an insight into the effect of various aging temperatures on the microstructure, hardness, phase transformation behavior and shape memory properties of Ti{sub 50}Ni{sub 15}Pd{sub 25}Cu{sub 10} high temperature shape memory alloy. The aging temperature was varied from 350 °C to 750 °C, whereas the shape memory properties were evaluated at 100–500 MPa. It was observed that the mentioned properties were strongly dependent on the aging temperatures. Based on the results obtained from scanning electron microscopy, X-ray diffractometry, microhardness testing, differential scanning calorimetry and thermomechanical testing, the aging temperatures can be divided into three ranges. At low aging temperatures (350 °C and below), the properties of the alloy remained the same as were found for solution treated sample, however at intermediate aging temperatures (400–600 °C) the properties of the alloy were changed significantly. Due to the formation of precipitates, the hardness was increased, whereas the phase transformation temperatures and work output were decreased considerably. The recovery ratio was found to be improved for intermediate aging temperatures. At high aging temperatures (650 °C and above), the hardness was decreased and the phase transformation temperatures were increased. Phase transformation temperature at the aging temperature of 750 °C was found to be increased significantly as compared to solution treated sample.

  7. Fusion of blastomeres in mouse embryos under the action of femtosecond laser radiation. Efficiency of blastocyst formation and embryo development

    Energy Technology Data Exchange (ETDEWEB)

    Osychenko, A A; Zalesskii, A D; Krivokharchenko, A S; Zhakhbazyan, A K; Nadtochenko, V A [N N Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow (Russian Federation); Ryabova, A V [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-05-31

    Using the method of femtosecond laser surgery we study the fusion of two-cell mouse embryos under the action of tightly focused femtosecond laser radiation with the fusion efficiency reaching 60%. The detailed statistical analysis of the efficiency of blastomere fusion and development of the embryo up to the blastocyst stage after exposure of the embryos from different mice to a femtosecond pulse is presented. It is shown that the efficiency of blastocyst formation essentially depends on the biological characteristics of the embryo, namely, the strain and age of the donor mouse. The possibility of obtaining hexaploid embryonal cells using the methods of femtosecond laser surgery is demonstrated. (extreme light fields and their applications)

  8. Interactive effects of biochar ageing in soils related to feedstock, pyrolysis temperature, and historic charcoal production.

    Science.gov (United States)

    Heitkötter, Julian; Marschner, Bernd

    2015-04-01

    Biochar is suggested for soil amelioration and carbon sequestration, based on its assumed role as the key factor for the long-term fertility of Terra preta soils. Several studies have shown that certain biochar properties can undergo changes through ageing processes, especially regarding charge characteristics. However, only a few studies determined the changes of different biochars under the same incubation conditions and in different soils. The objective of this study was to characterize the changes of pine chip (PC)- and corn digestate (CD)-derived biochars pyrolyzed at 400 or 600 °C during 100 days of laboratory incubation in a historical kiln soil and an adjacent control soil. Separation between soil and biochar was ensured by using mesh bags. Especially, changes in charge characteristics depended on initial biochar properties affected by feedstock and pyrolysis temperature and on soil properties affected by historic charcoal production. While the cation exchange capacity (CEC) markedly increased for both CD biochars during incubation, PC biochars showed no or only slight increases in CEC. Corresponding to the changes in CEC, ageing of biochars also increased the amount of acid functional groups with increases being in average about 2-fold higher in CD biochars than in PC biochars. Further and in contrast to other studies, the surface areas of biochars increased during ageing, likely due to ash leaching and degradation of tar residues. Changes in CEC and surface acidity of CD biochars were more pronounced after incubation in the control soil, while surface area increase was higher in the kiln soil. Since the two acidic forest soils used in this this study did not greatly differ in physical or chemical properties, the main process for inducing these differences in the buried biochar most likely is related to the differences in dissolved organic carbon (DOC). Although the kiln soil contained about 50% more soil organic carbon due to the presence of charcoal

  9. Hysteroscopic Subendometrial Embryo Delivery (SEED,Mechanical Embryo Implantation

    Directory of Open Access Journals (Sweden)

    Michael Kamrava

    2010-01-01

    Full Text Available Background: A major hurdle to improved in vitro fertilization (IVF success rate is defectiveendometrial receptivity and implantation. Various techniques have been advocated to increaseimplantation while reducing side effects. Currently, embryo transfer (ET is performed blindlywithout direct visualization. As such, we sought to develop a technique utilizing a flexible minihysteroscopewith a flexible catheter for direct implantation of the blastocyst(s.Materials and Methods: This was a case study performed at West Coast IVF Clinic, Inc., BeverlyHills, California 90212. A total of 15 IVF Cycles in 13 patients (average age = 29 underwentvisually directed ET and endometrial implantation. All women received luteal support.The main outcome measure in this study, both clinically and procedurally, was the relevantdevelopment and assessment of a novel surgical technology.Results: In this study, eight (60% pregnancies ensued [5 (62.5% clinical and 3 (37.5%biochemical]. Of note, there was no uterine scratching, uterine bleeding, or ectopic pregnancies.Significantly, high-order pregnancies were decreased; only one twin was conceived.Conclusion: Preliminary data suggest mechanically assisting implantation with a hysteroscopicblastocyst ET (SEED offers a viable option for improving pregnancy outcome.

  10. Toxicity of cryoprotectants on Prochilodus lineatus (Valenciennes, 1837 (curimba embryos in an experimental incubator (Characiformes: Prochilodontidae

    Directory of Open Access Journals (Sweden)

    Daniella A. J. Paula

    Full Text Available This paper investigated the effect of cryoprotectant substances on Prochilodus lineatus embryos in an experimental incubator. The prospective study applied combinations of polyvinyl alcohol, hydroxyethyl cellulose, gelatin and fetal bovine serum with dimethyl sulfoxide and ethylene glycol in a new experimental incubator. The morphology of embryos, larval viability and the efficiency of experimental incubators in maintaining the quality of embryos were evaluated. This study demonstrates the efficient association between hydroxyethylcellulose and dimethyl sulfoxide as greater viability (p<0.05 was found for embryos (72.9 ± 23.9%. It should also be noted the permeation of cryoprotectants in embryos through the changes found in chorion diameter, embryo diameter and embryo volume comparing the treatments versus control group (water (p<0.05, this results can help in future cryopreservation protocols. Although the temperature and oxygenation differed between the usual and experimental incubators (p<0.05, the results showed a high fertilization rate (79.6 ± 13.2% for experimental incubators (p<0.05 which is sufficient for the maintenance of embryos in a cryoprotective environment and effectively allows experimentation for long periods with cryoprotectant substances. Cryopreservation of fish embryos has not been accomplished yet and new approaches are required for understanding the permeability of teleost embryos, especially in Brazilian native species.

  11. Response to Selection at Two Temperatures for Fast and Slow Growth from Five to Nine Weeks of Age in Poultry

    OpenAIRE

    Bohren, B. B.; Carson, J. R.; Rogler, J. C.

    1981-01-01

    Cornell Control White Leghorn chicks were grown in a common environment to five weeks of age and selected for fast and slow gain in body weight from five to nine weeks of age at two temperatures, 21.1° (cold) and 32.2° (hot), during which time a constant 50% relative humidity was maintained. All lines were tested each generation in both temperature environments. Selection continued for four generations, with a second replicate started six weeks after the first replicate in each generation. In...

  12. Future aspects of micromanipualtion with embryos for

    African Journals Online (AJOL)

    implantation embryos which are then aggregated within one. Figure 3 ... Aggregating the two. \\sr. Figure 7 Scheme for producing chimeras by microsurgery. Embryo ll. A. (( %)). \\\\% tl. \\/. I oenuoins tne. Y embryo. Table 1a Results after transfer of half-embryos (review) .... After isolation and dissociation of the inner cell mass,.

  13. Effects of temperature and food quality on age and size at maturity in ectotherms: an experimental test with Atlantic salmon.

    Science.gov (United States)

    Jonsson, Bror; Jonsson, Nina; Finstad, Anders G

    2013-01-01

    The reaction norm between growth rate, age and size at maturity in ectotherms is widely debated in ecological literature. It has been proposed that the effect depends on whether growth is affected by food quality or temperature (called the Berrigan-Charnov puzzle). The present experiment tested this for Atlantic salmon (Salmo salar). We enhanced growth rates by increasing temperature and ratio of lipids to proteins in the food for groups of Atlantic salmon. Both treatments gave higher percentages of early mature and therefore smaller adults in contrast to the proposed Berrigan-Charnov puzzle. There was a difference between sexes in that males could attain maturity 1 year younger than females when reared under similar environmental conditions. Males that matured during the first year in sea water were smaller than similar aged immature males. The probability of that Atlantic salmon attained maturity for the first time during their second year in sea increased with growth rate during the preceding winter and if fed a high-lipid diet. Increased summer temperature exhibited no additional effect. Similar aged fish reared at elevated temperature and fed high-lipid diet attained maturity at a larger body mass and exhibited higher mass-length-ratios than those reared at natural temperature and fed a low-lipid diet, indicating that structural growth has priority over lipid deposits. Increased growth rate before the onset of maturation, whether this is owing to enhanced lipid content in food or increased water temperature, decreased age and therefore size at maturity. Enhanced lipid relative to protein content in food, but not temperature, had an additive positive effect on early maturation probability, likely due to increased amounts of reserve energy. These results may be general for ectotherm organisms. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

  14. Expectant Fathers, Abortion, and Embryos.

    Science.gov (United States)

    Purvis, Dara E

    2015-01-01

    One thread of abortion criticism, arguing that gender equality requires that men be allowed to terminate legal parental status and obligations, has reinforced the stereotype of men as uninterested in fatherhood. As courts facing disputes over stored pre-embryos weigh the equities of allowing implantation of the pre-embryos, this same gender stereotype has been increasingly incorporated into a legal balancing test, leading to troubling implications for ART and family law. © 2015 American Society of Law, Medicine & Ethics, Inc.

  15. Mechanical behavior of a Y-TZP ceramic for monolithic restorations: effect of grinding and low-temperature aging

    NARCIS (Netherlands)

    Pereira, G.K.R.; Silvestri, T.; Camargo, R.; Rippe, M.P.; Amaral, M.; Kleverlaan, C.J.; Valandro, L.F.

    2016-01-01

    This study aimed to investigate the effects of grinding with diamond burs and low-temperature aging on the mechanical behavior (biaxial flexural strength and structural reliability), surface topography, and phase transformation of a Y-TZP ceramic for monolithic dental restorations. Disc-shaped

  16. Age and temperature of shock metamorphism of Martian meteorite Los Angeles from (U-Th)/He thermochronometry

    Science.gov (United States)

    Min, Kyoungwon; Reiners, Peter W.; Nicolescu, Stefan; Greenwood, James P.

    2004-08-01

    Mineralogic features attributed to impact-induced shock metamorphism are commonly observed in meteorites and terrestrial impact craters. Partly because the duration of shock metamorphism is very short, constraining the timing and temperature of shock events has been problematic. We measured (U-Th)/He ages of single grains of merrillite and chlorapatite from the Martian meteorite Los Angeles (LA). Merrillite and chlorapatite ages cluster at 3.28 ± 0.15 Ma (2σ) and 2.18 ± 0.19 (2σ) Ma, respectively. The mean age of the merrillites, which are larger than chlorapatites, is indistinguishable from cosmic-ray exposure ages (3.1 ± 0.2 Ma), suggesting that impact-induced shock metamorphism was coeval with ejection of the LA precursor from Mars. To constrain the initial temperature of shock metamorphism in the LA precursor body, we modeled diffusive loss of He from merrillite as a function of diffusion domain size, LA precursor body size, and ablation depth. From these calculations, we suggest that the metamorphic temperature of the shock event was higher than 450 °C. These results support the idea that shock pressures of the Martian meteorite Shergotty were higher than 45 GPa, as inferred from the presence of post-stishovite SiO2 polymorphs. Single-grain (U-Th)/He dating of phosphates may provide unique constraints on the timing and pressure-temperature dynamics of shock metamorphism in a wide variety of extraterrestrial materials.

  17. Superovulation and embryo recovery in Boer goats treated with ...

    African Journals Online (AJOL)

    Lehloenya

    ICPbio Ltd, Auckland, New. Zealand) solution for a period of five minutes at room temperature to equilibrate. Thereafter, embryos were loaded in groups of two or four into 0.25 mL plastic straws (IMV®, L'Aigle, France). All straws were sealed.

  18. Microspore derived embryo formation and doubled haploid plant ...

    African Journals Online (AJOL)

    Microspore-derived embryos (MDE) formation was influenced by the strength of the NLN medium, the microelement and sugar concentration, and the heat shock temperature and period. The 0.5XNLN liquid medium was the most favorable for MDE formation. The most efficient formation of MDE was observed in the 0.5X ...

  19. Impact of the Ageing on Viscoelastic Properties of Bitumen with the Liquid Surface Active Agent at Operating Temperatures

    Science.gov (United States)

    Iwański, Marek; Cholewińska, Malgorzata; Mazurek, Grzegorz

    2017-10-01

    The paper presents the influence of the ageing on viscoelastic properties of the bitumen at road pavement operating temperatures. The ageing process of bituminous binders causes changes in physical and mechanical properties of the bitumen. This phenomenon takes place in all stages of bituminous mixtures manufacturing, namely: mixing, storage, transport, placing. Nevertheless, during the service life it occurs the increase in stiffness of asphalt binder that is caused by the physical hardening of bitumen as well as the influence of oxidation. Therefore, it is important to identify the binder properties at a high and low operating temperatures of asphalt pavement after simulation of an ageing process. In the experiment as a reference bitumen, the polymer modified bitumen PMB 45/80-65 was used. The liquid surface active agent FA (fatty amine) was used as a bitumen viscosity-reducing modifier. It was added in the amount of 0,2%, 0,4% and 0,6% by the bitumen mass. All binder properties have been determined before ageing (NEAT) and after long-term ageing simulated by the Pressure Ageing Vessel method (PAV). To determine the binder properties at high temperatures the dynamic viscosity at 60°C was tested. On the basis of test results coming from the dynamic viscosity test it was calculated the binder hardening index. The properties at a low temperature were determined by measuring the creep modulus using Bending Beam Rheometer (BBR) at four temperatures: -10°C, -16°C, -22°C and -28°C. The stiffness creep modulus “S” and parameter “m” were determined. On the basis of dynamic viscosity test it was found that the ageing process caused a slight decrease in a dynamic viscosity. The level of a hardening index considerably increased at 0.6% fatty amine content. The long-term ageing process had a minor effect on stiffening of a polymer modified bitumen with FA additive regardless of a low temperature and an amount of fatty amine content.

  20. Early-type galaxy archeology: Ages, abundance ratios, and effective temperatures from full-spectrum fitting

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, Charlie [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Graves, Genevieve J. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Van Dokkum, Pieter G. [Department of Astrophysical Sciences, Yale University, New Haven, CT 06511 (United States)

    2014-01-01

    The stellar populations of galaxies hold vital clues to their formation histories. In this paper we present results based on modeling stacked spectra of early-type galaxies drawn from the Sloan Digital Sky Survey as a function of velocity dispersion, σ, from 90 km s{sup –1} to 300 km s{sup –1}. The spectra are of extremely high quality, with typical signal-to-noise ratio of 1000 Å{sup –1}, and a wavelength coverage of 4000 Å –8800 Å. Our population synthesis model includes variation in 16 elements from C to Ba, a two-component star formation history, the shift in effective temperature, Δ T {sub eff}, of the stars with respect to a solar metallicity isochrone, and the stellar initial mass function, among other parameters. In our approach we fit the full optical spectra rather than a select number of spectral indices and are able to, for the first time, measure the abundances of the elements V, Cr, Mn, Co, and Ni from the integrated light of distant galaxies. Our main results are as follows: (1) light-weighted stellar ages range from 6-12 Gyr from low to high σ; (2) [Fe/H] varies by less than 0.1 dex across the entire sample; (3) Mg closely tracks O, and both increase from ≈0.0 at low σ to ∼0.25 at high σ; Si and Ti show a shallower rise with σ, and Ca tracks Fe rather than O; (4) the iron peak elements V, Cr, Mn, and Ni track Fe, while Co tracks O, suggesting that Co forms primarily in massive stars; (5) C and N track O over the full sample and [C/Fe] and [N/Fe] exceed 0.2 at high σ; and (6) the variation in Δ T {sub eff} with total metallicity closely follows theoretical predictions based on stellar evolution theory. This last result is significant because it implies that we are robustly solving not only for the detailed abundance patterns but also the detailed temperature distributions (i.e., isochrones) of the stars in these galaxies. A variety of tests reveal that the systematic uncertainties in our measurements are probably 0.05 dex or

  1. New Tools for Embryo Selection: Comprehensive Chromosome Screening by Array Comparative Genomic Hybridization

    Science.gov (United States)

    Cobo, Ana Cristina; Milán, Miguel; Al-Asmar, Nasser; García-Herrero, Sandra; Mir, Pere; Simón, Carlos

    2014-01-01

    The objective of this study was to evaluate the usefulness of comprehensive chromosome screening (CCS) using array comparative genomic hybridization (aCGH). The study included 1420 CCS cycles for recurrent miscarriage (n = 203); repetitive implantation failure (n = 188); severe male factor (n = 116); previous trisomic pregnancy (n = 33); and advanced maternal age (n = 880). CCS was performed in cycles with fresh oocytes and embryos (n = 774); mixed cycles with fresh and vitrified oocytes (n = 320); mixed cycles with fresh and vitrified day-2 embryos (n = 235); and mixed cycles with fresh and vitrified day-3 embryos (n = 91). Day-3 embryo biopsy was performed and analyzed by aCGH followed by day-5 embryo transfer. Consistent implantation (range: 40.5–54.2%) and pregnancy rates per transfer (range: 46.0–62.9%) were obtained for all the indications and independently of the origin of the oocytes or embryos. However, a lower delivery rate per cycle was achieved in women aged over 40 years (18.1%) due to the higher percentage of aneuploid embryos (85.3%) and lower number of cycles with at least one euploid embryo available per transfer (40.3%). We concluded that aneuploidy is one of the major factors which affect embryo implantation. PMID:24877108

  2. New Tools for Embryo Selection: Comprehensive Chromosome Screening by Array Comparative Genomic Hybridization

    Directory of Open Access Journals (Sweden)

    Lorena Rodrigo

    2014-01-01

    Full Text Available The objective of this study was to evaluate the usefulness of comprehensive chromosome screening (CCS using array comparative genomic hybridization (aCGH. The study included 1420 CCS cycles for recurrent miscarriage (n=203; repetitive implantation failure (n=188; severe male factor (n=116; previous trisomic pregnancy (n=33; and advanced maternal age (n=880. CCS was performed in cycles with fresh oocytes and embryos (n=774; mixed cycles with fresh and vitrified oocytes (n=320; mixed cycles with fresh and vitrified day-2 embryos (n=235; and mixed cycles with fresh and vitrified day-3 embryos (n=91. Day-3 embryo biopsy was performed and analyzed by aCGH followed by day-5 embryo transfer. Consistent implantation (range: 40.5–54.2% and pregnancy rates per transfer (range: 46.0–62.9% were obtained for all the indications and independently of the origin of the oocytes or embryos. However, a lower delivery rate per cycle was achieved in women aged over 40 years (18.1% due to the higher percentage of aneuploid embryos (85.3% and lower number of cycles with at least one euploid embryo available per transfer (40.3%. We concluded that aneuploidy is one of the major factors which affect embryo implantation.

  3. Lessons from Embryos: Haeckel's Embryo Drawings, Evolution, and Secondary Biology Textbooks

    Science.gov (United States)

    Wellner, Karen L.

    2014-01-01

    In 1997, developmental biologist Michael Richardson compared his research team's embryo photographs to Ernst Haeckel's 1874 embryo drawings and called Haeckel's work "noncredible". "Science" soon published "Haeckel's Embryos: Fraud Rediscovered," and Richardson's comments further reinvigorated criticism of Haeckel by…

  4. Development block of golden hamster ICSI embryos is associated with decreased expression of HDAC1, HSPA1A and MYC.

    Science.gov (United States)

    Pan, Xiaoyan; Kong, Delong; Liu, Limei; Gao, Fei; Zhang, Xueming; Tang, Bo; Li, Ziyi

    2014-11-01

    We have investigated the mechanism for embryo development block in vitro and to improve the development rate of golden hamster embryos in vitro. Intracytoplasmic sperm injection (ICSI) technique was used to produce golden hamster ICSI embryos. The changes in the histone acetylation and the expression of histone deacetylase and related genes were analyzed by immunocytochemical staining and real-time PCR both in golden hamster in vivo embryos and in ICSI embryos. Aged oocytes significantly increased the oocyte spontaneous activation rate. In vitro cultured ICSI embryos suffered from severe development block in M199TE medium. Expression of histone deacetylase 1 (HDAC1) was significantly decreased in the nuclei of the arrested ICSI 2-cell embryos, and its nuclear and cytoplasmic expression pattern was also markedly altered. The acetylation level of H4K5, however, was not significantly changed between golden hamster in vivo embryos and ICSI embryos. HSPA1A and MYC, the marker genes for zygotic genome activation (ZGA), were transcriptionally decreased in arrested ICSI 2-cell embryos. Transcription of HDAC1 was also downregulated in these embryos, whereas the mRNA expression of the proapoptotic gene, BAX, was not changed. These results indicate that the golden hamster ICSI embryo development block during ZGA is associated with decreased nuclear expression and altered expression of HDAC1. HSPA1A, MYC, and HDAC1 mRNA levels, which decrease, resulting in ZGA failure. © 2014 International Federation for Cell Biology.

  5. The influence of the type of embryo culture medium on neonatal birthweight after single embryo transfer in IVF.

    Science.gov (United States)

    Vergouw, Carlijn G; Kostelijk, E Hanna; Doejaaren, Els; Hompes, Peter G A; Lambalk, Cornelis B; Schats, Roel

    2012-09-01

    Does the type of medium used to culture fresh and frozen-thawed embryos influence neonatal birthweight after single embryo transfer (SET) in IVF? A comparison of two commercially available culture media showed no significant influence on mean birthweight and mean birthweight adjusted for gestational age, gender and parity (z-scores) of singletons born after a fresh or frozen-thawed SET. Furthermore, we show that embryo freezing and thawing cycles may lead to a significantly higher mean birthweight. Animal studies have shown that culture media constituents are responsible for changes in birthweight of offspring. In human IVF, there is still little knowledge of the effect of medium type on birthweight. Until now, only a small number of commercially available culture media have been investigated (Vitrolife, Cook(®) Medical and IVF online medium). Our study adds new information: it has a larger population of singleton births compared with the previously published studies, it includes outcomes of other media types (HTF and Sage(®)), not previously analysed, and it includes data on frozen-thawed SETs. This study was a retrospective analysis of birthweights of singleton newborns after fresh (Day 3) or frozen-thawed (Day 5) SET cycles, using embryos cultured in either of two different types of commercially available culture media, between 2008 and 2011. Before January 2009, a single-step culture medium was used: human tubal fluid (HTF) with 4 mg/ml human serum albumin. From January 2009 onwards, a commercially available sequential medium was introduced: Sage(®), Quinn's advantage protein plus medium. Singletons born after a fresh SET (99 embryos cultured in HTF and 259 in Sage(®)) and singletons born after a frozen-thawed SET (32 embryos cultured in HTF only, 41 in HTF and Sage(®) and 86 in Sage(®) only) were analysed. Only patients using autologous gametes without the use of a gestational carrier were considered. Also excluded were (vanishing) twins, triplets

  6. Influence of Eco-Friendly Mineral Additives on Early Age Compressive Strength and Temperature Development of High-Performance Concrete

    Science.gov (United States)

    Kaszynska, Maria; Skibicki, Szymon

    2017-12-01

    High-performance concrete (HPC) which contains increased amount of both higher grade cement and pozzolanic additives generates more hydration heat than the ordinary concrete. Prolonged periods of elevated temperature influence the rate of hydration process in result affecting the development of early-age strength and subsequent mechanical properties. The purpose of the presented research is to determine the relationship between the kinetics of the heat generation process and the compressive strength of early-age high performance concrete. All mixes were based on the Portland Cement CEM I 52.5 with between 7.5% to 15% of the cement mass replaced by the silica fume or metakaolin. Two characteristic for HPC water/binder ratios of w/b = 0.2 and w/b = 0.3 were chosen. A superplasticizer was used to maintain a 20-50 mm slump. Compressive strength was determined at 8h, 24h, 3, 7 and 28 days on 10x10x10 cm specimens that were cured in a calorimeter in a constant temperature of T = 20°C. The temperature inside the concrete was monitored continuously for 7 days. The study determined that the early-age strength (tage compressive strength of concrete. Concretes with additives reached the maximum temperature later than the concretes without them.

  7. Embryo density may affect embryo quality during in vitro culture in a microwell group culture dish.

    Science.gov (United States)

    Lehner, Adam; Kaszas, Zita; Murber, Akos; Rigo, Janos; Urbancsek, Janos; Fancsovits, Peter

    2017-08-01

    Culturing embryos in groups is a common practice in mammalian embryology. Since the introduction of different microwell dishes, it is possible to identify oocytes or embryos individually. As embryo density (embryo-to-volume ratio) may affect the development and viability of the embryos, the purpose of this study was to assess the effect of different embryo densities on embryo quality. Data of 1337 embryos from 228 in vitro fertilization treatment cycles were retrospectively analyzed. Embryos were cultured in a 25 μl microdrop in a microwell group culture dish containing 9 microwells. Three density groups were defined: Group 1 with 2-4 (6.3-12.5 μl/embryo), Group 2 with 5-6 (4.2-5.0 μl/embryo), and Group 3 with 7-9 (2.8-3.6 μl/embryo) embryos. Proportion of good quality embryos was higher in Group 2 on both days (D2: 18.9 vs. 31.5 vs. 24.7%; p Culturing 5-6 embryos together in a culture volume of 25 μl may benefit embryo quality. As low egg number, position, and distance of the embryos may influence embryo quality, results should be interpreted with caution.

  8. Single top quality embryo transfer as a model for prediction of early pregnancy outcome.

    Science.gov (United States)

    De Neubourg, D; Gerris, J; Mangelschots, K; Van Royen, E; Vercruyssen, M; Elseviers, M

    2004-06-01

    Single embryo transfer (particularly of a top quality embryo) is an excellent model to correlate embryo quality in terms of morphological criteria to early pregnancy. We investigated whether this model could provide us with more information on what happens after implantation in the first trimester of pregnancy. The outcome of 370 consecutive single top quality embryo transfers in patients younger than 38 years was analysed for pregnancy and first-trimester pregnancy loss (FTPL) before 13 weeks of gestation. Analysis was done on each cohort of embryos from which the transferred top quality embryo was selected. Serum HCG levels were measured on day 8 and day 12 after day 3 embryo transfer. The HCG index was calculated as the level of HCG on day 12/HCG on day 8. The pregnancy rate after single top quality embryo transfer was 51.9%. This was independent of the patients' age. FTPL, however, appeared to be age dependent: 15.4% for the whole group, 9% in patients younger than 30 years and 19% in patients above 30 years. The pregnancy rate was 50% in IVF cycles and 52% in ICSI cycles; FTPL was 19% in IVF cycles and 10% in ICSI cycles. Multiple regression analysis showed that these differences originated from age differences between both populations rather than from technique-related factors. An HCG level >or=45 IU/l on day 12 was predictive for ongoing pregnancy with 75.6% sensitivity and 100% specificity; an HCG index >or=3.5 similarly predicted ongoing pregnancy with 72.3% sensitivity and 100% specificity. These data show that embryo selection for transfer on day 3 can be used as an excellent tool for prediction of pregnancy but not for prediction of FTPL. The pregnancy rate of a single top quality embryo is not related to age, whereas FTPL is age dependent.

  9. Strengthening mechanisms in ultrafine grained Al-Mg-Si alloy processed by hydrostatic extrusion – Influence of ageing temperature

    Energy Technology Data Exchange (ETDEWEB)

    Chrominski, Witold, E-mail: wichr@inmat.pw.edu.pl [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland); Wenner, Sigurd [Department of Physics, Norwegian University of Science and Technology (NTNU), 7491 Trondheim (Norway); Marioara, Calin D. [SINTEF Materials and Chemistry, 7465 Trondheim (Norway); Holmestad, Randi [Department of Physics, Norwegian University of Science and Technology (NTNU), 7491 Trondheim (Norway); Lewandowska, Malgorzata [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland)

    2016-07-04

    Microstructure of hydrostatically extruded Al-Mg-Si alloy was studied by the combination of electron backscattered diffraction and transmission electron microscopy. Three different grain types which feature various defects arrangements were detected. Post deformation ageing at two temperatures caused different precipitation phenomena which were strongly dependent on type of grain boundaries in the considered grain types. Thus, a combination of plastic deformation and ageing resulted in a material with complex microstructure. Based on transmission electron microscopy observations, contributions of different strengthening mechanisms were estimated and compared to experimental results. A good agreement between obtained data points confirmed that depending on grain type, different strengthening mechanisms are operative and the overall strength is a sum of hardening given by each of them. Ageing of ultrafine grain structure results in efficient precipitation strengthening. On the other hand ageing causes annihilation of low and high angle grains boundaries in which leads to softening of investigated material. This effect cannot be compensated by precipitation hardening.

  10. The human embryo: ethical and legal aspects.

    Science.gov (United States)

    Knoppers, Bartha Maria; Bordet, Sylvie; Isasi, Rosario

    2009-01-01

    This paper analyses the status of the embryo in Canadian law. First, a brief overview of some ethical issues raised by research with embryos, focusing on the moral status of the embryo, is presented. A survey of the regulatory framework applicable to embryo research in Canada follows, so as to delineate the legal status of the embryo in Canada and its ethical underpinnings. A summary of applicable regulation in Germany, the United Kingdom, and the United States is also undertaken, illustrating the lack of consensus on this issue in Western countries. Finally, recent developments in stem cell research are considered, focusing on current alternatives to embryo destruction.

  11. Transfer of European mink (Mustela lutreola) embryos into hybrid recipients.

    Science.gov (United States)

    Amstislavsky, Sergei; Aalto, Jussi; Järvinen, Mikko; Lindeberg, Heli; Valtonen, Maija; Zudova, Galina; Ternovskaya, Yulia

    2004-08-01

    The European mink is considered as a highly endangered Mustelidae species. The objective of this study was to explore the intriguing possibility of embryo transfer from European mink to closely related Mustelidae recipient females. To overcome interspecies pregnancy failure, embryos of European mink (Mustela lutreola) were transferred into hybrid females obtained after mating of European polecat (Mustela putorius) males and European mink (M. lutreola) females and vice versa. A total of 32 blastocysts were surgically flushed from the uteri of nine European mink donors and surgically transferred into six pseudopregnant hybrid recipients. One of the recipients received a single embryo and did not whelp. The remaining five recipients each received five to eight embryos and delivered kits. The overall success rate was 50% (16 kits/32 transferred embryos). For both male and female offspring, the average birth weight was lower in ET group when compared with naturally bred control population of European mink. The postnatal mortality rate was significantly higher in ET group as compared to controls: only 9 of 16 kits survived past the first week. At 10 days of age, the average weight for male offspring from the ET and control groups did not differ, although differences still persisted at this age for female offspring. At 3 months of age, the weight of male and female offspring in the ET group did not differ from European minks born after natural mating. We propose that transfer of European mink embryos to hybrid recipients be considered as a new experimental tool within the framework of ex situ approach conservation of this aboriginal European mustelid.

  12. Fundamental cryobiology of mouse ova and embryos

    Energy Technology Data Exchange (ETDEWEB)

    Leibo, S. P.

    1977-01-01

    An increasing fraction of mouse ova and embryos are killed as the rate at which they are cooled to -196/sup 0/C is increased. The survival of these cells depends not only on cooling rate, but also on the minimum subzero temperature to which the cells are cooled. Low temperature microscopy demonstrates that lethal cooling rates are coincident with those that produce intracellular ice formation, and that the lethal temperature appears to be that at which intracellular ice forms. Furthermore, the microscopy shows that ova do not dehydrate when cooled at rates that produce intracellular ice and cell death, but undergo substantial shrinkage when cooled at rates that produce little intracellular ice and high survival. Measurements of the water permeability of mouse ova and the temperature coefficient of that permeability can be used to test a mathematical model formulated to describe the kinetics of water loss at subzero temperatures from a hypothetical cell. The observed dehydration of ova cooled to subzero temperatures at given rates is approximately predicted by the mathematical model, although there is some quantitative discrepancy between the observed and calculated responses.

  13. The endo-siRNA pathway is essential for robust development of the Drosophila embryo.

    Directory of Open Access Journals (Sweden)

    Elena M Lucchetta

    2009-10-01

    Full Text Available Robustness to natural temperature fluctuations is critical to proper development in embryos and to cellular functions in adult organisms. However, mechanisms and pathways which govern temperature compensation remain largely unknown beyond circadian rhythms. Pathways which ensure robustness against temperature fluctuations may appear to be nonessential under favorable, uniform environmental conditions used in conventional laboratory experiments where there is little variation for which to compensate. The endo-siRNA pathway, which produces small double-stranded RNAs in Drosophila, appears to be nonessential for robust development of the embryo under ambient uniform temperature and to be necessary only for viral defense. Embryos lacking a functional endo-siRNA pathway develop into phenotypically normal adults. However, we hypothesized that small RNAs may regulate the embryo's response to temperature, as a ribonucleoprotein complex has been previously shown to mediate mammalian cell response to heat shock.Here, we show that the genes DICER-2 and ARGONAUTE2, which code for integral protein components of the endo-siRNA pathway, are essential for robust development and temperature compensation in the Drosophila embryo when exposed to temperature perturbations. The regulatory functions of DICER-2 and ARGONAUTE2 were uncovered by using microfluidics to expose developing Drosophila embryos to a temperature step, in which each half of the embryo develops at a different temperature through developmental cycle 14. Under this temperature perturbation, dicer-2 or argonaute2 embryos displayed abnormal segmentation. The abnormalities in segmentation are presumably due to the inability of the embryo to compensate for temperature-induced differences in rate of development and to coordinate developmental timing in the anterior and posterior halves. A deregulation of the length of nuclear division cycles 10-14 is also observed in dicer-2 embryos at high temperatures

  14. Effect of aging heat time and annealing temperature on the properties of nanocrystalline tin dioxide thin films

    Science.gov (United States)

    Kadhim, Imad H.; Abu Hassan, H.

    2017-04-01

    Nanocrystalline tin dioxide (SnO2) thin films have been successfully prepared by sol-gel spin-coating technique on p-type Si (100) substrates. A stable solution was prepared by mixing tin(II) chloride dihydrate, pure ethanol, and glycerin. Temperature affects the properties of SnO2 thin films, particularly the crystallite size where the crystallization of SnO2 with tetragonal rutile structure is achieved when thin films that prepared under different aging heat times are annealed at 400∘C. By increasing aging heat time in the presence of annealing temperatures the FESEM images indicated that the thickness of the fabricated film was directly proportional to solution viscosity, increasing from approximately 380 nm to 744 nm, as well as the crystallization of the thin films improved and reduced defects.

  15. Frequency of chromosomal aneuploidy in high quality embryos from young couples using preimplantation genetic screening

    Directory of Open Access Journals (Sweden)

    Farzaneh Fesahat

    2017-09-01

    Full Text Available Background: Selection of the best embryo for transfer is very important in assisted reproductive technology (ART. Using morphological assessment for this selection demonstrated that the correlation between embryo morphology and implantation potential is relatively weak. On the other hand, aneuploidy is a key genetic factor that can influence human reproductive success in ART. Objective: The aim of this lab trial study was to evaluate the incidence of aneuploidies in five chromosomes in the morphologically high-quality embryos from young patients undergoing ART for sex selection. Materials and Methods: A total of 97 high quality embryos from 23 women at the age of 37or younger years that had previously undergone preimplantation genetic screening for sex selection were included in this study. After washing, the slides of blastomeres from embryos of patients were reanalyzed by fluorescence in-situ hybridization for chromosomes 13, 18 and 21. Results: There was a significant rate of aneuploidy determination in the embryos using preimplantation genetic screening for both sex and three evaluated autosomal chromosomes compared to preimplantation genetic screening for only sex chromosomes (62.9% vs. 24.7%, p=0.000. The most frequent detected chromosomal aneuploidy was trisomy or monosomy of chromosome 13. Conclusion: There is considerable numbers of chromosomal abnormalities in embryos generated in vitro which cause in vitro fertilization failure and it seems that morphological characterization of embryos is not a suitable method for choosing the embryos without these abnormalities

  16. Frequency of chromosomal aneuploidy in high quality embryos from young couples using preimplantation genetic screening.

    Science.gov (United States)

    Fesahat, Farzaneh; Montazeri, Fatemeh; Sheikhha, Mohammad Hasan; Saeedi, Hojjatollah; Dehghani Firouzabadi, Razieh; Kalantar, Seyed Mehdi

    2017-05-01

    Selection of the best embryo for transfer is very important in assisted reproductive technology (ART). Using morphological assessment for this selection demonstrated that the correlation between embryo morphology and implantation potential is relatively weak. On the other hand, aneuploidy is a key genetic factor that can influence human reproductive success in ART. The aim of this lab trial study was to evaluate the incidence of aneuploidies in five chromosomes in the morphologically high-quality embryos from young patients undergoing ART for sex selection. A total of 97 high quality embryos from 23 women at the age of 37or younger years that had previously undergone preimplantation genetic screening for sex selection were included in this study. After washing, the slides of blastomeres from embryos of patients were reanalyzed by fluorescence in-situ hybridization for chromosomes 13, 18 and 21. There was a significant rate of aneuploidy determination in the embryos using preimplantation genetic screening for both sex and three evaluated autosomal chromosomes compared to preimplantation genetic screening for only sex chromosomes (62.9% vs. 24.7%, p=0.000). The most frequent detected chromosomal aneuploidy was trisomy or monosomy of chromosome 13. There is considerable numbers of chromosomal abnormalities in embryos generated in vitro which cause in vitro fertilization failure and it seems that morphological characterization of embryos is not a suitable method for choosing the embryos without these abnormalities.

  17. A Computational Design of UHS Maraging Stainless Steels Incorporating Composition as well as Austenitisation and Ageing Temperatures as Optimisation Parameters

    OpenAIRE

    Xu, Wei; Rivera-Diaz-Del-Castillo, P.E. J.; van der Zwaag, Sybrand

    2009-01-01

    Abstract An extended integral alloy design approach for the development of new ultra high strength maraging steels is presented which incorporates not only chemical composition effects but also criteria accounting for the influence of the entire heat treatment. The approach accounts for the desired strengthening precipitates formed during the final ageing treatment as well as undesirable equilibrium phases present during the preceding high temperature homogenisation treatment. The...

  18. Coupling between atmospheric CO2 and temperature during the onset of the Little Ice Age

    NARCIS (Netherlands)

    Hoof, T.B. van

    2004-01-01

    Present day global warming is primarily caused by the greenhouse effect of the increased CO2 emissions since the onset of the industrial revolution. A coupling between temperature and the greenhouse gas CO2 has also been observed in several ice-core records on a glacial-interglacial timescale as

  19. Numerical modeling of hydration process and temperature evolution in early age concrete

    NARCIS (Netherlands)

    Caggiano, A.; Pepe, M.; Koenders, E.A.B.; Martinelli, E.; Etse, G.J.

    2012-01-01

    Heat production induced by the hydration reaction and the resulting temperature evolution in the early phases of setting and hardening processes are critical phenomena, often leading to premature cracking of concrete members. However, the interest for simulating such phenomena is also related to the

  20. Effect of Embryo Banking on U.S. National Assisted Reproductive Technology Live Birth Rates.

    Science.gov (United States)

    Kushnir, Vitaly A; Barad, David H; Albertini, David F; Darmon, Sarah K; Gleicher, Norbert

    2016-01-01

    Assisted Reproductive Technology (ART) reports generated by the Centers for Disease Control and Prevention (CDC) exclude embryo banking cycles from outcome calculations. We examined data reported to the CDC in 2013 for the impact of embryo banking exclusion on national ART outcomes by recalculating autologous oocyte ART live birth rates. Inflation of reported fresh ART cycle live birth rates was assessed for all age groups of infertile women as the difference between fresh cycle live births with reference to number of initiated fresh cycles (excluding embryo banking cycles), as typically reported by the CDC, and fresh cycle live births with reference to total initiated fresh ART cycles (including embryo banking cycles). During 2013, out of 121,351 fresh non-donor ART cycles 27,564 (22.7%) involved embryo banking. The proportion of banking cycles increased with female age from 15.5% in women 44 years. Concomitantly, the proportion of thawed cycles decreased with advancing female age (P banking cycles led to inflation of live birth rates in fresh ART cycles, increasing in size in parallel to advancing female age and utilization of embryo banking, reaching 56.3% in women age >44. The inflation of live birth rates in thawed cycles could not be calculated from the publically available CDC data but appears to be even greater. Utilization of embryo banking increased during 2013 with advancing female age, suggesting a potential age selection bias. Exclusion of embryo banking cycles from national ART outcome reports significantly inflated national ART success rates, especially among older women. Exclusion of embryo banking cycles from US National Assisted Reproductive Technology outcome reports significantly inflates reported success rates especially in older women.

  1. L10 ordered structures in Al-Cu-(Mg) alloys at the early stages of elevated temperature aging

    Energy Technology Data Exchange (ETDEWEB)

    Fuzhong, X.; Mingpu, W.

    2016-07-01

    This study concerns the precipitation structures of Al-3Cu and Al-3Cu-1.78Mg (wt. %) alloys at the early stages of elevated temperature aging. The Al-3Cu and Al-3Cu-1.78 Mg alloys were solution treated at 540 °C and 500 °C for 2 h, respectively, and then aged at 190 °C for 2 min. The precipitation structures in aged Al-3Cu-(1.78Mg) alloys were characterized by Transmission Electron Microscopy (TEM) and High Resolution Transmission Electron Microscopy (HTREM). 001 zone axis Selected area electron diffraction patterns indicate that L10 ordered structures are formed in the two aged alloys. HRTEM experiments reveal the partial dislocations on the interfaces of L10 ordered structures. From comparing experimental results with that in the literature, it is concluded that the L10 ordered structures in aged Al-3Cu alloy consist of Al and Cu atoms, and they are comprised by Al, Cu and Mg atoms together in the aged Al-3Cu-1.78Mg alloy. On the basis of precipitate growing thermodynamics, it is thought the L10 ordered structures act as nuclei for GP zones in Al-Cu-(Mg) alloys during aging. (Author)

  2. Chromatin remodeling in mammalian embryos.

    Science.gov (United States)

    Cabot, Birgit; Cabot, Ryan A

    2018-03-01

    The mammalian embryo undergoes a dramatic amount of epigenetic remodeling during the first week of development. In this review, we discuss several epigenetic changes that happen over the course of cleavage development, focusing on covalent marks (e.g., histone methylation and acetylation) and non-covalent remodeling (chromatin remodeling via remodeling complexes; e.g., SWI/SNF-mediated chromatin remodeling). Comparisons are also drawn between remodeling events that occur in embryos from a variety of mammalian species. © 2018 Society for Reproduction and Fertility.

  3. Identification of the glycerol kinase gene and its role in diapause embryo restart and early embryo development of Artemia sinica.

    Science.gov (United States)

    Cheng, Cheng; Yao, Feng; Chu, Bing; Li, Xuejie; Liu, Yan; Wu, Yang; Mei, Yanli; Wang, Peisheng; Hou, Lin; Zou, Xiangyang

    2014-03-01

    Glycerol kinase (GK) catalyzes the rate-limiting step in glycerol utilization by transferring a phosphate from ATP to glycerol, yielding glycerol 3-phosphate, which is an important intermediate for both energy metabolism and glycerolipid production. Artemia sinica has an unusual diapause process under stress conditions of high salinity, low temperature and lack of food. In the process, diapause embryos of A. sinica (brine shrimp) accumulate high concentrations of glycerol as a cryoprotectant to prevent low temperature damage to embryos. Upon embryo restart, glycerol is converted into glucose and other carbohydrates. Therefore, GK plays an important role in the diapause embryo restart process. However, the role of GK in diapause termination of embryo development in A. sinica remains unknown. In the present study, a 2096 bp full-length cDNA of gk from A. sinica (As-gk) was obtained, encoding putative 551 amino acids, 60.6 kDa protein. As a crucial enzyme in glycerol uptake and metabolism, GK has been conserved structurally and functionally during evolution. The expression pattern of As-gk was investigated by quantitative real-time PCR and Western blotting. Expression locations of As-gk were analyzed using in situ hybridization. As-gk was widely distributed in the early embryo and several main parts of Artemia after differentiation. The expression of As-GK was also induced by stresses such as cold exposure and high salinity. This initial research into the expression pattern and stress response of GK in Artemia provides a sound basis for further understanding of the function and regulation of genes in early embryonic development in A. sinica and the stress response. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Which set of embryo variables is most predictive for live birth? A prospective study in 6252 single embryo transfers to construct an embryo score for the ranking and selection of embryos.

    Science.gov (United States)

    Rhenman, A; Berglund, L; Brodin, T; Olovsson, M; Milton, K; Hadziosmanovic, N; Holte, J

    2015-01-01

    Which embryo score variables are most powerful for predicting live birth after single embryo transfer (SET) at the early cleavage stage? This large prospective study of visual embryo scoring variables shows that blastomere number (BL), the proportion of mononucleated blastomeres (NU) and the degree of fragmentation (FR) have independent prognostic power to predict live birth. Other studies suggest prognostic power, at least univariately and for implantation potential, for all five variables. A previous study from the same centre on double embryo transfers with implantation as the end-point resulted in the integrated morphology cleavage (IMC) score, which incorporates BL, NU and EQ. A prospective cohort study of IVF/ICSI SET on Day 2 (n = 6252) during a 6-year period (2006-2012). The five variables (BL NU, FR, EQ and symmetry of cleavage (SY)) were scored in 3- to 5-step scales and subsequently related to clinical pregnancy and LBR. A total of 4304 women undergoing IVF/ICSI in a university-affiliated private fertility clinic were included. Generalized estimating equation models evaluated live birth (yes/no) as primary outcome using the embryo variables as predictors. Odds ratios with 95% confidence intervals and P-values were presented for each predictor. The C statistic (i.e. area under receiver operating characteristic curve) was calculated for each model. Model calibration was assessed with the Hosmer-Lemeshow test. A shrinkage method was applied to remove bias in c statistics due to over-fitting. LBR was 27.1% (1693/6252). BL, NU, FR and EQ were univariately highly significantly associated with LBR. In a multivariate model, BL, NU and FR were independently significant, with c statistic 0.579 (age-adjusted c statistic 0.637). EQ did not retain significance in the multivariate model. Prediction model calibration was good for both pregnancy and live birth. We present a ranking tree with combinations of values of the BL, NU and FR embryo variables for optimal

  5. Irradiation/temperature synergy effects on degradation and ageing of chlorosulphonated polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Foucault, F.; Esnouf, S. E-mail: esnouf@drecam.cea.fr; Le Moeel, A

    2001-12-01

    Chlorosulphonated polyethylene (CSPE) irradiated with 2.5 MeV {beta} particles has been studied by means of FTIR spectroscopy. The effects of dose rate, temperature and atmosphere on molecular changes were investigated. The main modifications were loss of sulphonyl chloride groups, formation of trans-vinylene groups and in the presence of oxygen formation of oxidation products. Results were discussed in terms of interspur and intraspur reactions.

  6. Irradiation/temperature synergy effects on degradation and ageing of chlorosulphonated polyethylene

    Science.gov (United States)

    Foucault, F.; Esnouf, S.; Le Moël, A.

    2001-12-01

    Chlorosulphonated polyethylene (CSPE) irradiated with 2.5 MeV β particles has been studied by means of FTIR spectroscopy. The effects of dose rate, temperature and atmosphere on molecular changes were investigated. The main modifications were loss of sulphonyl chloride groups, formation of trans-vinylene groups and in the presence of oxygen formation of oxidation products. Results were discussed in terms of interspur and intraspur reactions.

  7. The effect of maternal and grandmaternal age in benign and high temperature environments

    DEFF Research Database (Denmark)

    Faurby, S; Kjaersgaard, A; Pertoldi, C

    2005-01-01

    Maternal age is known to be of importance for the fitness of the offspring. Few studies have, however, been able to analyse this phenomenon as an isolated effect without confounding effects through genetic variation. This difficulty can be circumvented by working with parthenogenetic organisms. We...... all the traits. Two opposing factors seem to shape the effects of maternal age. Senescence in older mothers leads to a reduction in offspring fitness, whereas, plastic responses lead to more competitive and stress resistant offspring from older mothers. The relative importance of these factors...

  8. Correlation analysis of human embryo LeY glycan antigen expression and embryo quality.

    Science.gov (United States)

    Gu, Juan; Sui, Linlin; Ma, Yanni; Guo, Zhenzhen; Zhang, Man; Zhu, Chenyang; Cai, Zhu; Kong, Ying

    2017-07-01

    This study assessed the feasibility of using LeY glycan secretion level in human embryos as a method of judging embryo quality. Embryo culture media from patients receiving in vitro fertilization-embryo transfer was collected, and quality scores of embryos were recorded. Secretions of LeY in the culture media in different development stages (from 4-cell to 10-cell), embryos in the same development stage of the same patients (8-cell/I) and embryos in the same development stage of different patients (8-cell/I) were examined by dot-blot. Embryos were divided into a hypersecretion group and hyposecretion group, based on their LeY secretion level. The embryo quality was evaluated by clinical observations, the number which developed to D3 cell stage and the number of successful embryo transplantations. LeY secretion increased as embryos developed from 4-cell to 10-cell (PLeY of 8/I is not identical; development speed of embryos with different secretion level of LeY was also different. The number of embryos which developed to 6-cell or higher was 82.2% in the LeY hypersecretion group but only 60% in the hyposecretion group. The rate of successful transplantation was significantly higher in the hypersecretion group (71.1 vs. 40%). In conclusion, LeY glycan secretion level in human embryos is closely related to embryo quality. LeY may become a useful measure to evaluate embryo quality in the future.

  9. Survival of mouse embryos after vitrification depending on the cooling rate of the cryoprotectant solution.

    Science.gov (United States)

    Hredzák, R; Ostró, A; Zdilová, Viera; Maracek, I; Kacmárik, J

    2006-03-01

    The aim of the study was to determine the relationship between the rate of cooling of eight-cell mouse embryos to the temperature of liquid nitrogen (-196 degrees C) and their developmental capacity after thawing on the basis of their ability to leave the zona pellucida ('hatching') during in vitro culturing. Eight-cell embryos were obtained from superovulated female mice and divided into three experimental and one control group. Embryos from the experimental groups were cryopreserved by the vitrification method using ethylene glycol as cryoprotectant. The vitrification protocols used in the study differed in the rate of cooling of the cryoprotectant solution. Embryos from the first group were frozen in conventional 0.25-ml plastic straws, those from the second group in pipetting 'tips', and embryos from the third group, placed in vitrification solution, were introduced dropwise directly into liquid nitrogen. The control group of embryos was cultured in vitro without freezing in a culturing medium in an environment consisting of 95% air and 5% CO2. The developmental capacity of thawed embryos was assessed on the basis of their ability to leave the zona pellucida ('hatching') after three days of in vitro culturing. In the control group 95.1% of embryos 'hatched'. A significantly higher number of embryos that 'hatched' after thawing was observed in the group introduced dropwise directly into liquid nitrogen (60.0%) compared to the group frozen in pipetting 'tips' (37.9%). The group frozen in straws yielded significantly the lowest proportion of 'hatching' embryos (8.1%). These results showed that increasing cooling rates during vitrification of embryos improved their survival.

  10. Embryo growth in mature celery seeds

    NARCIS (Netherlands)

    Toorn, van der P.

    1989-01-01

    Germination of celery seeds is slow, due to the need for embryo growth before radicle protrusion can occur. Germination rate was correlated with embryo growth rate. Celery seeds with different embryo growth rates were obtained with fluid density separation of a seed lot. Low density seeds

  11. Mechanistic dissection of plant embryo initiation

    NARCIS (Netherlands)

    Radoeva, T.M.

    2016-01-01

    Land plants can reproduce sexually by developing an embryo from a fertilized egg cell, the zygote. After fertilization, the zygote undergoes several rounds of controlled cell divisions to generate a mature embryo. However, embryo formation can also be induced in a variety of other cell types in many

  12. Large baby syndrome in singletons born after frozen embryo transfer (FET)

    DEFF Research Database (Denmark)

    Pinborg, Anja; Henningsen, AA; Loft, A

    2013-01-01

    Are singletons born after frozen embryo transfer (FET) at increased risk of being born large for gestational age (LGA) and if so, is this caused by intrinsic maternal factors or related to the freezing/thawing procedures?...

  13. Evaluation and Response of Aged Flexible Airfield Pavements at Ambient Temperatures Using the Falling Weight Deflectometer

    Science.gov (United States)

    1988-01-01

    3) accessibilty to the airfield, especially during the day, was virtually unlimited, 4) the entire airfield, excluding parking aprons, was comprised...role. 135 LU C4 Cy! C CU 0 C*4O LU - CC-) 0 - AUla j? cc IL 0 01 tn in P4 4 Lui ( tn to4- .~0 N U LLL 0m Sr CHAPTER 6 ANALYSES OF FIELD MEASURED FWD...tempera- tures were virtually the same for both sites. This showed that as the degree of cracking in the asphalt concrete diminished, temperature

  14. Reexamining age, race, site, and thermometer type as variables affecting temperature measurement in adults – A comparison study

    Directory of Open Access Journals (Sweden)

    Smith Linda S

    2003-06-01

    Full Text Available Abstract Background As a result of the recent international vigilance regarding disease assessment, accurate measurement of body temperature has become increasingly important. Yet, trusted low-tech, portable mercury glass thermometers are no longer available. Thus, comparing accuracy of mercury-free thermometers with mercury devices is essential. Study purposes were 1 to examine age, race, site as variables affecting temperature measurement in adults, and 2 to compare clinical accuracy of low-tech Galinstan-in-glass device to mercury-in-glass at oral, axillary, groin, and rectal sites in adults. Methods Setting 176 bed accredited healthcare facility, rural northwest US Participants Convenience sample (N = 120 of hospitalized persons ≥ 18 years old. Instruments Temperatures (°F measured at oral, skin (simultaneous, immediately followed by rectal sites with four each mercury-glass (BD and Galinstan-glass (Geratherm thermometers; 10 minute dwell times. Results Participants averaged 61.6 years (SD 17.9, 188 pounds (SD 55.3; 61% female; race: 85% White, 8.3% Native Am., 4.2% Hispanic, 1.7 % Asian, 0.8% Black. For both mercury and Galinstan-glass thermometers, within-subject temperature readings were highest rectally; followed by oral, then skin sites. Galinstan assessments demonstrated rectal sites 0.91°F > oral and ≅ 1.3°F > skin sites. Devices strongly correlated between and across sites. Site difference scores between devices showed greatest variability at skin sites; least at rectal site. 95% confidence intervals of difference scores by site (°F: oral (0.142 – 0.265, axilla (0.167 – 0.339, groin (0.037 – 0.321, and rectal (-0.111 – 0.111. Race correlated with age, temperature readings each site and device. Conclusion Temperature readings varied by age, race. Mercury readings correlated with Galinstan thermometer readings at all sites. Site mean differences between devices were considered clinically insignificant. Still considered

  15. Effects of different hatcher temperatures on hatching traits of broiler ...

    African Journals Online (AJOL)

    Hatching time, hatchability, age of mortality and the incidence of embryo malpositions were recorded as percentage of fertile eggs. The highest mean embryonic heat production or eggshell surface temperature occurred in the hatching cabinets operated at 39.9 °C and lowest at 36.1 °C. Eggs incubated at 37.2 °C and 38.3 ...

  16. TWIN PREGNANCY AFTER THE TRANSFER OF TWO EMBRYOS

    Directory of Open Access Journals (Sweden)

    Lili Bačer Kermavner

    2003-12-01

    Full Text Available Background. Twin pregnancy rates following the transfer of two embryos in in vitro fertilization (IVF treatment are high. Therefore, the aim of this study was to evaluate twin pregnancy rates in regard to the developmental stage of the embryo, patient age, and cause of infertility.Methods. A retrospective analysis involved 1222 IVF procedures. Overall pregnancy rates and twin pregnancy rates following the transfer of two blastocysts or two cleavage-stage embryos were assessed. The blastocyst group was divided into four age subgroups, and into four subgroups by the cause of infertility.Results. After the transfer of two blastocysts or two cleavagestage embryos the overall pregnancy rates (45% vs. 9% and the twin pregnancy rates (18% vs. 5% were significantly higher in the blastocyst group. The effects of patient age and the transfer of two blastocysts on the overall pregnancy and twin pregnancy rates were significantly greater in the subgroups of patients aged ≤ 30 years (21% and 31–34 years (20% than in older patients (35–38 years = 15.7%; ≥ 39 years = 9%. In the blastocyst group the twin pregnancy rate was significantly higher in patients with tubal (21% and endocrinological causes of infertility (24.5% than in patients with endometriosis (7% and uterine malformations (12.5%.Conclusions. After the transfer of two blastocysts twin pregnancy rates are significantly higher in patients with tubal factor or endocrinological causes of infertility younger than 34 years. In this population of women the risk of twin pregnancy can be avoided by the transfer of a single embryo – most developed blastocyst.

  17. Metamizole Sodium Induces Neural Tube Defects in a Chick Embryo Model.

    Science.gov (United States)

    Guvenc, Yahya; Billur, Deniz; Aydin, Sevim; Ozeren, Ersin; Demirci, Adnan; Alagoz, Fatih; Dalgic, Ali; Belen, Deniz

    The aim of this study was to investigate the effects of metamizole sodium on neural tube development in the early stage chick embryo model that complies with the first month of embryonic development in mammals. A total of 40 fertilized chicken eggs were divided into 4 equal groups. The eggs were incubated in the incubator at a temperature of 37.8±2°C with 60±5% humidity. Group A was the control, Group B was administered physiological saline, Group C was administered 30 mg/kg metamizole sodium (based on the therapeutic index range of it used in humans) and Group D was administered 90 mg/kg metamizole sodium. All embryos were removed from the egg at the 48th hour and morphologically and histologically examined. Normal development was seen and the neural tube was closed in 17 embryos in Groups A and B. A neural tube defect was seen in 2 embryos in group A and in 1 embryo in group B. A neural tube closure defect was seen in all embryos in group C and 9 embryos in group D. There was 1 dead embryo in Group D. Metamizole sodium was seen to produce a neural tube defect in the chicken embyro model.

  18. Role of temperature and hosts (Sitotroga cereallela and Corcyra cephalonica egg age on the quality production of Trichogramma chilonis

    Directory of Open Access Journals (Sweden)

    Farzana Perveen

    2012-12-01

    Full Text Available The present study was conducted for efficient and quality production of the stingless wasp, Trichogramma chilonis Ishii with respect to rearing temperature and host egg age of the angoumois grain moth, Sitotroga cereallela (Olivier and the rice meal moth, Corcyra cephalonica (Stainton on its biology. Maximum parasitism was observed 95.7 and 84.3% at 28 C degree, while minimum parasitism was 61.3 and 39.6% at 32 C degree on S. cereallela and C. cephalonica eggs, respectively. The most favorable temperature was 28 oC on which maximum parasitism and adult emergence were obtained from S. cereallela eggs. Maximum parasitism was observed 97.4 and 79.4% in 2 h old, while minimum parasitism was 24.6 and 17.3% in 72 h old eggs of S. cereallela and C. cephalonica eggs, respectively. Parasitism by T. chilonis decreased with increasing host eggs age. Maximum adult T. chilonis emergence was 98.2% in 2 h old eggs, while minimum emergence was 21.5% on 72 h old eggs of S. cereallela. Adult T. chilonis longevity on the host eggs of different ages of female wasp was non-significantly different to each other except the 2 and 12 h old eggs which were significantly different from rest of the treatments in both hosts' eggs of different ages. Maximum female longevity was 4.0 d on 2 h fresh eggs C. cephalonica, while minimum was 3.0 d on 24-48 h old S. cereallela eggs. The female ratio for different host eggs age was almost non-significant to each other except 2 h old eggs with maximum number of female (64. The results showed that T. chilonis preferred young eggs when offered older eggs, simultaneously.

  19. Does the number of oocytes retrieved influence pregnancy after fresh embryo transfer?

    Directory of Open Access Journals (Sweden)

    Qianfang Cai

    Full Text Available BACKGROUND: The nature of the association between the number of oocytes retrieved and in vitro fertilization (IVF outcomes after fresh embryo transfer remains unclear because of conflicting results reported in the studies on this subject. In addition, the influence of the quality of the embryos transferred is usually neglected. The objective of this study is to assess the relationships of the number of oocytes retrieved, the number and quality of embryos transferred, and the prospects of pregnancy after fresh embryo transfer. METHODS: The data on 3131 infertile women undergoing their first IVF treatment cycle between January 2009 and December 2010 were collected retrospectively. Restricted cubic splines and stratified analyses were used to explore the relationships between the number of oocytes retrieved, the number and quality of embryos transferred, and the IVF outcomes. RESULTS: When stratified by the number and quality of transferred embryos, no significant differences in the chances for clinical pregnancy and live birth were found in three groups of oocytes yielded (≤6, 7-14, or ≥15. The relationship between the number of oocytes retrieved and pregnancy is nearly a reflection of the pattern of the relationship between the number of oocytes retrieved and the probability of having two good-quality embryos transferred. The patients with the "optimal" number of oocytes were not only younger but also had the highest probability of having two good-quality embryos replaced. CONCLUSIONS: Similarly aged patients have similar pregnancy prospects after fresh embryo transfer when the same number and quality of embryos are replaced, irrespective of their number of oocytes. Selecting the desired number of good-quality embryos for transfer is the key to IVF success. Thus, aiming at retrieving an optimal number of oocytes to maximize IVF outcomes in a fresh cycle could place undue stress on the patients and may not be the best medical decision.

  20. Nitrogen release from differently aged Raphanus sativus L. nitrate catch crops during mineralization at autumn temperatures

    DEFF Research Database (Denmark)

    Thomsen, Ingrid Kaag; Elsgaard, Lars; Olesen, Jørgen Eivind

    2016-01-01

    radish (Raphanus sativus, L.) has emerged as a promising nitrate catch crop in cereal cropping, although the course of remineralization of residue N following termination of this frost-sensitive crucifer remains obscured. We incubated radish residues of different age (different planting and harvest dates......) with a loamy sand soil; mineralization of residue N was determined after 1, 2, 4 and 7 months of incubation at 2 °C and 10 °C. Incubations with soil only and with residues of white mustard (Sinapis alba, L) and perennial ryegrass (Lolium perenne, L.) were included as references. Using linear regression, net N...

  1. Differences in gene expression profiles between human preimplantation embryos cultured in two different IVF culture media.

    Science.gov (United States)

    Kleijkers, Sander H M; Eijssen, Lars M T; Coonen, Edith; Derhaag, Josien G; Mantikou, Eleni; Jonker, Martijs J; Mastenbroek, Sebastiaan; Repping, Sjoerd; Evers, Johannes L H; Dumoulin, John C M; van Montfoort, Aafke P A

    2015-10-01

    Is gene expression in human preimplantation embryos affected by the medium used for embryo culture in vitro during an IVF treatment? Six days of in vitro culture of human preimplantation embryos resulted in medium-dependent differences in expression level of genes involved in apoptosis, protein degradation, metabolism and cell-cycle regulation. Several human studies have shown an effect of culture medium on embryo development, pregnancy outcome and birthweight. However, the underlying mechanisms in human embryos are still unknown. In animal models of human development, it has been demonstrated that culture of preimplantation embryos in vitro affects gene expression. In humans, it has been found that culture medium affects gene expression of cryopreserved embryos that, after thawing, were cultured in two different media for 2 more days. In a multicenter trial, women were randomly assigned to two culture medium groups [G5 and human tubal fluid (HTF)]. Data on embryonic development were collected for all embryos. In one center, embryos originating from two pronuclei (2PN) zygotes that were not selected for transfer or cryopreservation on Day 2 or 3 because of lower morphological quality, were cultured until Day 6 and used in this study, if couples consented. Ten blastocysts each from the G5 and HTF study groups, matched for fertilization method, maternal age and blastocyst quality, were selected and their mRNA was isolated and amplified. Embryos were examined individually for genome-wide gene expression using Agilent microarrays and PathVisio was used to identify the pathways that showed a culture medium-dependent activity. Expression of 951 genes differed significantly (P differences observed between the study groups are caused by factors that we did not investigate. Extrapolation of these results to embryos used for transfer demands caution as in the present study embryos that were not selected for either embryo transfer or cryopreservation have been used for the

  2. Factors that affect the reproductive efficiency of the recipient within a bovine embryo transfer program

    Directory of Open Access Journals (Sweden)

    Arturo Duica A.

    2007-12-01

    Full Text Available The embryo transfer is a biotechnological technique that allows increasing the descendant of animals with high genetic value. The positive results, represented in pregnancy after the application of this technique, are affected by some factors that are inherent to the donor, the embryo, the technique, and the recipients which receive a strange embryo in the uterus allowing pregnancy. This review describes some factors affecting the reproductive efficiency of the recipients of bovine embryos within a program of embryo transfer. Its important to evaluate the parameters in this kind of recipients, as race, age, physiological status, health status, weight, reproductive tract integrity and management, and also too monitoring the ovarian structures while the estrus synchronization, and within previous and posterior stages in embryo transfer procedure. Therefore an optimum follicular development will be determinant to corpus luteum formation which generates enough serum progesterone concentrations to offer a right uterine environment allowing the optimum embryo development. Controlling the factors that affect the efficiency of the embryo transfer, it will obtain an increasing of positive results represented in pregnancies and births of individuals come from animals with high genetic value.

  3. Age

    Science.gov (United States)

    ... distressing side effects. Do anesthesia risks increase in older adults? One concern for older patients is that the aging brain is more ... related surgery risks that are more common in older people: ... problems with memory and paying attention. It may not start until a few days ...

  4. The effect of irradiation, annealing temperature, and artificial aging on the oxidation, mechanical properties, and fracture mechanisms of UHMWPE.

    Science.gov (United States)

    Luisetto, Yannick; Wesslen, Bengt; Maurer, Frans; Lidgren, Lars

    2003-12-01

    UHMWPE crosslinked using Gamma radiation is believed to have improved wear properties, and this has been extensively studied during the past 10 years. Mechanical properties, oxidation, and wear properties of UHMWPE materials subjected to various thermal treatments have been investigated immediately after irradiation as well as after several years of aging. Nevertheless, the relationship between all these parameters is not yet fully understood. The aim of this study was to investigate the relationship between the thermal treatments that could be applied to irradiated UHMWPE [lower (gamma 60) or higher (gamma 150) than 140 degrees C, the melting temperature of the polymer] and the mechanical properties, the oxidation and the fracture behavior of the material. The effect of artificial aging on these properties was also investigated. This study concludes that immediately after the annealing, the mechanical properties (UTS and epsilon) of the irradiated and annealed material are improved compared with those of nonirradiated material. Although nonirradiated material has higher fracture toughness than irradiated and annealed materials, the materials break according to the same mechanism of fracture. After aging, no changes could be observed in any of the measured properties for nonirradiated material. On the other hand, important changes could be seen in both irradiated and annealed material after aging. Both UTS and epsilon decreased, much more so in the case of gamma 60. Furthermore, the aging induced a subsurface peak of oxidation in both irradiated and annealed materials, twice as intense for gamma 60 than for gamma 150. The mechanism of fracture of these materials changed drastically after aging, probably due to the presence of the oxidation peak, which seems to occur at a location where cracks initiate easily compared with the nonoxidized bulk of the material. In the case of gamma 60, it seems clear that a correlation between mechanical property, oxidation, and

  5. PLANETARY EMBRYO BOW SHOCKS AS A MECHANISM FOR CHONDRULE FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Christopher R.; Boley, Aaron C. [Department of Physics and Astronomy University of British Columbia Vancouver, BC V6T 1Z1 (Canada); Morris, Melissa A. [Physics Department State University of New York at Cortland Cortland, NY 13045 (United States)

    2016-02-20

    We use radiation hydrodynamics with direct particle integration to explore the feasibility of chondrule formation in planetary embryo bow shocks. The calculations presented here are used to explore the consequences of a Mars-size planetary embryo traveling on a moderately excited orbit through the dusty, early environment of the solar system. The embryo’s eccentric orbit produces a range of supersonic relative velocities between the embryo and the circularly orbiting gas and dust, prompting the formation of bow shocks. Temporary atmospheres around these embryos, which can be created via volatile outgassing and gas capture from the surrounding nebula, can non-trivially affect thermal profiles of solids entering the shock. We explore the thermal environment of solids that traverse the bow shock at different impact radii, the effects that planetoid atmospheres have on shock morphologies, and the stripping efficiency of planetoidal atmospheres in the presence of high relative winds. Simulations are run using adiabatic and radiative conditions, with multiple treatments for the local opacities. Shock speeds of 5, 6, and 7 km s{sup −1} are explored. We find that a high-mass atmosphere and inefficient radiative conditions can produce peak temperatures and cooling rates that are consistent with the constraints set by chondrule furnace studies. For most conditions, the derived cooling rates are potentially too high to be consistent with chondrule formation.

  6. The reliability of the repair weld joints of aged high temperature components in fossil power boilers

    Energy Technology Data Exchange (ETDEWEB)

    Okamura, Hiroyuki [Science Univ. of Tokyo (Japan); Ohtani, Ryuichi [Kyoto Univ. (Japan); Fujii, Kazuya [Japan Power Engineering and Inspection Corp., Tokyo (Japan); Yokoyama, Tomomitsu; Nishimura, Nobuhiko [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Suzuki, Komei [Japan Steel Works Ltd., Tokyo (Japan)

    1998-11-01

    It is of fundamental engineering importance to be able to give reliable assessments of the effective service life of the critical components used within fossil power plants, particularly for those operating for prolonged periods. It is common practice for such assessments to have been estimated using destructive tests, typically the stress rupture test, this having been recognized as one of the most reliable evaluation methods available. Its only drawback is that it often does not permit the component to be in use following the sampling of the test specimen without repairing. The current piece of work focuses on the reliability of the repair welds of components for specimens taken from fossil power plants, having been in service for prolonged periods. Several such repairs to welds have been made to an old power boiler, in particular to a superheater header which is fabricated from 2.25Cr-1Mo steel. Under close examination the repairs to the girth weldment showed susceptibilities of weld cracking, similar to that observed in as-manufactured material. Within the repaired region of the welded joint the microstructure, tensile properties and toughness seemed to be unaffected. The hardness attained its minimum value within the heat affected zone, HAZ of the repair weld, overlapping that of original girth weld HAZ. Furthermore, the stress rupture strength achieved its minimum value at the same position taking on the same value as the strength associated with the aged girth welded joint. (orig.)

  7. No effect of embryo culture media on birthweight and length of newborns.

    Science.gov (United States)

    Lin, Shengli; Li, Ming; Lian, Ying; Chen, Lixue; Liu, Ping

    2013-07-01

    Does the type of media used to culture embryos for IVF influence the birthweight and length of neonates? No significant differences were observed in birthweight and length among the three embryo culture media used for in vitro embryo culture. Since the establishment of IVF as an assisted reproductive technology (ART), many different culture systems have been used for the development of human embryos. Some studies have shown that the types of culture media influence the newborn birthweight; however, other studies have shown no effect. To further explore this contradictory issue, we compared the birthweight and length of neonates born after the transfer of embryos cultured in one of three commercially available media. This retrospective analysis of birthweight and length of newborns included 1201 women who delivered singletons and 445 women who delivered twins. The following three commercially available culture media were used: G5™, Global and Quinn's advantage media. Women who underwent IVF-ET cycles between 2008 and 2010 were analyzed. Patients younger than 40 years of age with a body mass index (BMI) culture medium. Inter-twin mean birthweight and length disparities were analyzed, but were not shown to be significantly different. Multiple linear regression analysis showed that maternal weight, maternal height, gestational age and infant gender were significantly related to birthweight, and paternal height, gestational age and newborn complications were significantly associated with birth length. The current study showed that birthweight and length of newborns were not associated with the embryo culture medium. More research needs to be performed to analyze the effects of other culture medium formulations and to evaluate the long-term effects of embryo culture medium on the health of children conceived through ART. WIDER IMPLICATIONS OF THESE FINDINGS: Our retrospective study suggests that embryo culture medium does not influence neonatal birthweight and length

  8. Real-time observation of perturbation of a Drosophila embryo's early cleavage cycles with microfluidics.

    Science.gov (United States)

    Bai, Zeqing; Bao, Hongcun; Yuan, Yingying; Yang, Xiaohang; Xi, Yongmei; Wang, Min

    2017-08-22

    It is of great importance to understand biochemical system's behavior toward environmental perturbation during the development of living organisms. Here a microfluidic platform for Drosophila embryo's online development and observation is presented. The system is capable of developing the embryo's anterior and posterior halves controlled at different temperature environments, and it can be easily coupled with a confocal microscope for real-time image acquisition. The microfluidic chip is consisted of a polymethylmethacrylate (PMMA) substrate with a thickness of 4.0 mm and a polydimethylsiloxane (PDMS) cover designed with a typical 'Y' channel with a depth of 400 μm, width of 800 μm. Temperature gradients were created across the anterior half and posterior half of the embryo by utilizing two streams of laminar flow with different temperatures. It was found that thermal gradient would result in asynchronous development of the two halves of the embryos, and the developing difference was related to the direction of thermal gradient. This may result from the presence of an unknown mechanism located in the anterior half of the embryo, which oversees nuclear division synchronicity. These observations would help better understand compensatory mechanisms of Drosophila embryo's development under environmental perturbations. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Pollination and embryo development in Brassica rapa L. in microgravity

    Science.gov (United States)

    Kuang, A.; Popova, A.; Xiao, Y.; Musgrave, M. E.

    2000-01-01

    Plant reproduction under spaceflight conditions has been problematic in the past. In order to determine what aspect of reproductive development is affected by microgravity, we studied pollination and embryo development in Brassica rapa L. during 16 d in microgravity on the space shuttle (STS-87). Brassica is self-incompatible and requires mechanical transfer of pollen. Short-duration access to microgravity during parabolic flights on the KC-135A aircraft was used initially to confirm that equal numbers of pollen grains could be collected and transferred in the absence of gravity. Brassica was grown in the Plant Growth Facility flight hardware as follows. Three chambers each contained six plants that were 13 d old at launch. As these plants flowered, thin colored tape was used to indicate the date of hand pollination, resulting in silique populations aged 8-15 d postpollination at the end of the 16-d mission. The remaining three chambers contained dry seeds that germinated on orbit to produce 14-d-old plants just beginning to flower at the time of landing. Pollen produced by these plants had comparable viability (93%) with that produced in the 2-d-delayed ground control. Matched-age siliques yielded embryos of equivalent developmental stage in the spaceflight and ground control treatments. Carbohydrate and protein storage reserves in the embryos, assessed by cytochemical localization, were also comparable. In the spaceflight material, growth and development by embryos rescued from siliques 15 d after pollination lagged behind the ground controls by 12 d; however, in the subsequent generation, no differences between the two treatments were found. The results demonstrate that while no stage of reproductive development in Brassica is absolutely dependent upon gravity, lower embryo quality may result following development in microgravity.

  10. Evaluation of day one embryo quality and IVF outcome – a comparison of two scoring systems

    Directory of Open Access Journals (Sweden)

    Svobodova Magda

    2009-02-01

    Full Text Available Abstract Background The aim of our retrospective study was to compare the clinical usefulness of two non-invasive embryo scoring systems based either on a simplified pronuclear morphology of the zygote or on early cleavage rate, as well as their combination, for the selection of embryos with the best implantation potential in embryo transfer (ET. Methods Over a period of five years, the quality of 2708 embryos from 364 IVF cycles in women under the age of 39 years was assessed using these scoring systems in a university assisted reproduction centre. ET was always performed on day 3 of cultivation. The outcome of ETs of 702 embryos scored in the respective systems or their combination was retrospectively analyzed in terms of biochemical (bPR and clinical pregnancy rates (cPR and implantation rate (IR. Mann-Whitney U test and t-test for differences between relative values were used, p Results There was no difference in outcome parameters in 109 cycles where only Pattern "0" zygotes, according to our simplified pronuclear morphology classification, were transferred and 140 cycles where only "other" pattern zygotes were transferred, regardless of their cleavage rate. On the contrary, significantly greater cPR and IR (p = 0.003 and p = 0.006, respectively were achieved in 120 cycles where only early cleavage (EC embryos were transferred compared with 152 cycles where only non early cleavage (NEC embryos were transferred regardless of their pronuclear morphology. The best outcome in terms of cPR (56% and IR (43% was found in 50 cycles when Pattern "0" and EC embryos only were used for transfer. Conclusion The results indicate that early cleavage is a better independent marker of implantation potential than zygote morphology. The best outcome can be achieved if both embryo scoring systems are used jointly and the embryo is classified as EC and Pattern "0".

  11. A new model for the estimation of time of death from vitreous potassium levels corrected for age and temperature.

    Science.gov (United States)

    Zilg, B; Bernard, S; Alkass, K; Berg, S; Druid, H

    2015-09-01

    Analysis of potassium concentration in the vitreous fluid of the eye is frequently used by forensic pathologists to estimate the postmortem interval (PMI), particularly when other methods commonly used in the early phase of an investigation can no longer be applied. The postmortem rise in vitreous potassium has been recognized for several decades and is readily explained by a diffusion of potassium from surrounding cells into the vitreous fluid. However, there is no consensus regarding the mathematical equation that best describes this increase. The existing models assume a linear increase, but different slopes and starting points have been proposed. In this study, vitreous potassium levels, and a number of factors that may influence these levels, were examined in 462 cases with known postmortem intervals that ranged from 2h to 17 days. We found that the postmortem rise in potassium followed a non-linear curve and that decedent age and ambient temperature influenced the variability by 16% and 5%, respectively. A long duration of agony and a high alcohol level at the time of death contributed less than 1% variability, and evaluation of additional possible factors revealed no detectable impact on the rise of vitreous potassium. Two equations were subsequently generated, one that represents the best fit of the potassium concentrations alone, and a second that represents potassium concentrations with correction for decedent age and/or ambient temperature. The former was associated with narrow confidence intervals in the early postmortem phase, but the intervals gradually increased with longer PMIs. For the latter equation, the confidence intervals were reduced at all PMIs. Therefore, the model that best describes the observed postmortem rise in vitreous potassium levels includes potassium concentration, decedent age, and ambient temperature. Furthermore, the precision of these equations, particularly for long PMIs, is expected to gradually improve by adjusting the

  12. Reptile Embryos Lack the Opportunity to Thermoregulate by Moving within the Egg.

    Science.gov (United States)

    Telemeco, Rory S; Gangloff, Eric J; Cordero, Gerardo A; Mitchell, Timothy S; Bodensteiner, Brooke L; Holden, Kaitlyn G; Mitchell, Sarah M; Polich, Rebecca L; Janzen, Fredric J

    2016-07-01

    Historically, egg-bound reptile embryos were thought to passively thermoconform to the nest environment. However, recent observations of thermal taxis by embryos of multiple reptile species have led to the widely discussed hypothesis that embryos behaviorally thermoregulate. Because temperature affects development, such thermoregulation could allow embryos to control their fate far more than historically assumed. We assessed the opportunity for embryos to behaviorally thermoregulate in nature by examining thermal gradients within natural nests and eggs of the common snapping turtle (Chelydra serpentina; which displays embryonic thermal taxis) and by simulating thermal gradients within nests across a range of nest depths, egg sizes, and soil types. We observed little spatial thermal variation within nests, and thermal gradients were poorly transferred to eggs. Furthermore, thermal gradients sufficiently large and constant for behavioral thermoregulation were not predicted to occur in our simulations. Gradients of biologically relevant magnitude have limited global occurrence and reverse direction twice daily when they do exist, which is substantially faster than embryos can shift position within the egg. Our results imply that reptile embryos will rarely, if ever, have the opportunity to behaviorally thermoregulate by moving within the egg. We suggest that embryonic thermal taxis instead represents a play behavior, which may be adaptive or selectively neutral, and results from the mechanisms for behavioral thermoregulation in free-living stages coming online prior to hatching.

  13. Palaeontology: pterosaur embryo from the Early Cretaceous.

    Science.gov (United States)

    Wang, Xiaolin; Zhou, Zhonghe

    2004-06-10

    Dinosaur embryos have been discovered all over the world, but so far no pterosaur embryos have been reported. Here we describe a Chinese fossil from the Early Cretaceous period containing an embryo that is unambiguously a pterosaur. The embryonic skeleton, which is exquisitely preserved in its egg, is associated with eggshell fragments, wing membranes and skin imprints. This discovery confirms that pterosaurs were egg-layers and sheds new light on our understanding of pterosaur development.

  14. Survival of Macrobrachium amazonicum embryos submitted to cooling.

    Science.gov (United States)

    Ferreira, Arthur Vinícius Lourenço; Martins, Moisés Fernandes; Martins de Sousa, Míriam Luzia Nogueira; Soares Filho, Aldeney Andrade; Sampaio, Célia Maria de Souza

    2017-06-01

    Cooling techniques have several applications for reproduction in aquaculture. However, few studies have sought to create protocols for cooling and cryopreservation of Macrobrachium amazonicum embryos. Thus, the objective of this work was to verify the survival of M. amazonicum embryos and the correlation between embryonic volume and mortality of M. amazonicum embryos after cooling. Embryo pools were collected from three females and divided into two treatment groups: dimethyl sulfoxide (DMSO) 3% and ethylene glycol (EG) 0.5%, both of them associated with 2 M sucrose. Positive and negative control groups consisted of seawater 10%. Aliquots of 10 µg of embryos were placed in Falcon® tubes containing a cryoprotectant solution and submitted directly to the test temperature of 2°C for 2 and 6 h of cooling. Further analysis of survival and embryonic volume were performed under a stereoscopic microscope. Data were subjected to analysis of variance (ANOVA), and means were compared using the Tukey test at 5%. The highest embryonic survival rate was observed after the shortest storage time for both the DMSO 3% and the 0.5% EG groups, with survival rates of 84.8 ± 3.9 and 79.7 ± 2.8%, respectively. There was a reduction in survival after 24 h, with the DMSO 3% group presenting a survival rate of 71.7 ± 6.6%, and the EG 0.5% group, 66 ± 6.9%. Survival showed a statistically significant difference when compared with the positive controls after 2 h and 24 h of cooling, with 99 ± 0.5% and 95.8 ± 1.5% survival rates, respectively. There was no significant statistical difference in the embryonic volume, but it was possible to observe a change in the appearance of the embryos, from a translucent coloration to an opaque white or brownish coloration, after 24 h in incubators. Thus, it can be concluded that survival is inversely proportional to storage time and that, although there was no change in the embryonic volume after cooling, a change in the appearance of embryos could

  15. A Chemically Defined Medium for Rabbit Embryo Cryopreservation

    Science.gov (United States)

    Bruyère, Pierre; Baudot, Anne; Joly, Thierry; Commin, Loris; Pillet, Elodie; Guérin, Pierre; Louis, Gérard; Josson-Schramme, Anne; Buff, Samuel

    2013-01-01

    This study evaluates a new synthetic substitute (CRYO3, Ref. 5617, Stem Alpha, France) for animal-based products in rabbit embryo cryopreservation solutions. This evaluation was performed using two approaches: a thermodynamic approach using differential scanning calorimetry and a biological approach using rabbit embryo slow-freezing. During the experiment, foetal calf serum (FCS) was used as a reference. Because FCS varies widely by supplier, three different FCS were selected for the thermodynamic approach. The rabbit embryo slow-freezing solutions were made from Dulbecco's phosphate buffer saline containing 1.5 M Dimethyl Sulfoxide and 18% (v.v−1) of CRYO3 or 18% (v.v−1) of FCS. These solutions were evaluated using four characteristics: the end of melting temperature, the enthalpy of crystallisation (thermodynamic approach) and the embryo survival rates after culture and embryo transfer (biological approach). In the thermodynamic approach, the solutions containing one of the three different FCS had similar mean thermodynamic characteristics but had different variabilities in the overall data with aberrant values. The solution containing CRYO3 had similar thermodynamic properties when compared to those containing FCS. Moreover, no aberrant value was measured in the solution containing CRYO3. This solution appears to be more stable than the solutions containing a FCS. In the biological approach, the in vitro embryo survival rates obtained with the solution containing CRYO3 (73.7% and 81.3%) and with the solution containing a FCS (77.6% and 71.9%) were similar (p = 0.7). Nevertheless, during the in vivo evaluation, the implantation rate (21.8%) and the live-foetuses rate (18.8%) of the CRYO3 group were significantly higher than the implantation rate (7.1%, p = 0.0002) and the live-foetuses rate (5.3%, p = 0.0002) of the FCS group. The pregnancy rate was also higher in the CRYO3 group compared to the FCS group (81.3% and 43.8%, respectively, p = 0

  16. Somatic embryogenesis and plant regeneration from embryo rescue ...

    African Journals Online (AJOL)

    The application of tissue culture techniques, particularly in the area of embryo rescue, has had a major impact on the maintenance and development of hybrid embryo from wide crosses. Embryo rescue techniques are directed towards obtaining more efficient survival of embryos in situations where very immature embryos ...

  17. Interactive effects of ambient temperature and light sources at high relative humidity on growth performance and blood physiological variables in broilers grown to 42 day of age

    Science.gov (United States)

    The interactive effects of ambient temperature and light sources at high relative humidity on growth performance and blood physiological reactions in broilers grown to 42 day of age were investigated. The experiment consisted of 2 levels (Moderate=21.1, High=26.7 °C) of temperatures and 2 light sour...

  18. A comparison of live birth rates and perinatal outcomes between cryopreserved oocytes and cryopreserved embryos.

    Science.gov (United States)

    Ho, Jacqueline R; Woo, Irene; Louie, Kristin; Salem, Wael; Jabara, Sami I; Bendikson, Kristin A; Paulson, Richard J; Chung, Karine

    2017-10-01

    Prior studies suggest that pregnancy outcomes after autologous oocyte cryopreservation are similar to fresh in vitro fertilization (IVF) cycles. It is unknown whether there are differences in pregnancy and perinatal outcomes between cryopreserved oocytes and cryopreserved embryos. This is a retrospective cohort study comparing pregnancy and perinatal outcomes between oocyte and embryo cryopreservation at a university-based fertility center. We included 42 patients and 68 embryo transfers in patients who underwent embryo transfer after elective oocyte preservation (frozen oocyte-derived embryo transfer (FOET)) from 2005 to 2015. We compared this group to 286 patients and 446 cycles in women undergoing cryopreserved embryo transfer (frozen embryo transfer (FET)) from 2012 to 2015. Five hundred fourteen transfer cycles were included in our analysis. The mean age was lower in the FOET vs FET group (34.3 vs 36.0 years), but there were no differences in ovarian reserve markers. Thawed oocytes had lower survival than embryos (79.1 vs 90.1%); however, fertilization rates were similar (76.2 vs 72.8%). In the FOET vs FET groups, clinical pregnancies were 26.5 and 30%, and live birth rates were 25 and 25.1%. Miscarriages were higher in the FET group, 8.1 vs 1.5%. There were no differences in perinatal outcomes between the two groups. The mean gestational age at delivery was 39.1 vs 38.6 weeks, mean birth weight 3284.2 vs 3161.1 gms, preterm gestation rate 5.9 vs 13.4%, and multiple gestation rate 5.9 vs 11.6%. In our study, live birth rates and perinatal outcomes were not significantly different in patients after oocyte and embryo cryopreservation.

  19. Transmission of Campylobacter coli in chicken embryos

    Directory of Open Access Journals (Sweden)

    Daise Aparecida Rossi

    2012-06-01

    Full Text Available Campylobacter coli is an important species involved in human cases of enteritis, and chickens are carriers of the pathogen mainly in developing country. The current study aimed to evaluate the transmission of C. coli and its pathogenic effects in chicken embryos. Breeder hens were inoculated intra-esophageally with C. coli isolated from chickens, and their eggs and embryos were analyzed for the presence of bacteria using real-time PCR and plate culture. The viability of embryos was verified. In parallel, SPF eggs were inoculated with C. coli in the air sac; after incubation, the embryos were submitted to the same analysis as the embryos from breeder hens. In embryos and fertile eggs from breeder hens, the bacterium was only identified by molecular methods; in the SPF eggs, however, the bacterium was detected by both techniques. The results showed no relationship between embryo mortality and positivity for C. coli in the embryos from breeder hens. However, the presence of bacteria is a cause of precocious mortality for SPF embryos. This study revealed that although the vertical transmission is a possible event, the bacteria can not grow in embryonic field samples.

  20. Embryo Implantation: War in Times of Love.

    Science.gov (United States)

    Ashary, Nancy; Tiwari, Abhishek; Modi, Deepak

    2018-02-01

    Contrary to widespread belief, the implantation of an embryo for the initiation of pregnancy is like a battle, in that the embryo uses a variety of coercive tactics to force its acceptance by the endometrium. We propose that embryo implantation involves a three-step process: (1) identification of a receptive endometrium; (2) superimposition of a blastocyst-derived signature onto the receptive endometrium before implantation; and finally (3) breaching by the embryo and trophoblast invasion, culminating in decidualization and placentation. We review here the story that is beginning to emerge, focusing primarily on the cells that are in "combat" during this process. Copyright © 2018 Endocrine Society.

  1. Effect of Layer and Film Thickness and Temperature on the Mechanical Property of Micro- and Nano-Layered PC/PMMA Films Subjected to Thermal Aging

    Directory of Open Access Journals (Sweden)

    Ahmed Abdel-Mohti

    2015-04-01

    Full Text Available Multilayered polymer films with biomimicking, layered structures have unique microstructures and many potential applications. However, a major limitation of polymer films is the deterioration of mechanical properties in working environments. To facilitate the design and development of multilayered polymer films, the impact of thermal aging on the mechanical behavior of micro- and nano-layered polymer films has been investigated experimentally. The composition of the polymer films that have been studied is 50 vol% polycarbonate (PC and 50 vol% poly(methyl methacrylate (PMMA. The current study focuses on the effect of film and layer thickness and temperature on the mechanical properties of the materials subjected to thermal aging. To study the effect of film and layer thickness, films with the same thickness, but various layer thicknesses, and films with the same layer thickness, but various film thicknesses, were thermally aged at 100 °C in a constant temperature oven for up to six weeks. The results show that as the layer thickness decreases to 31 nm, the film has a higher stiffness and strength, and the trend of the mechanical properties is relatively stable over aging. The ductility of all of the films decreases with aging time. To study the effect of temperature, the films with 4,096 layers (31 nm thick for each layer were aged at 100 °C, 115 °C and 125 °C for up to four weeks. While the 100 °C aging results in a slight increase of the stiffness and strength of the films, the higher aging temperature caused a decrease of the stiffness and strength of the films. The ductility decreases with the aging time for all of the temperatures. The films become more brittle for higher aging temperatures.

  2. Flight mill performance of the lacewing Chrysoperla sinica (Neuroptera: Chrysopidae) as a function of age, temperature, and relative humidity.

    Science.gov (United States)

    Liu, Zhongfang; McNeil, Jeremy N; Wu, Kongming

    2011-02-01

    The lacewing Chrysoperla sinica (Tjeder) (Neuroptera: Chrysopidae) is an important predator of several insect pests in China and has considerable potential as a biological control agent. An inoculative approach would be the releasing adults early in the season to ensure that populations are present before pest densities increase. However, an understanding of adult flight activity under different conditions is necessary to develop appropriate release strategies. Therefore, we used a 32-channel, computer-monitored flight mill system to determine the effect of age on the flight activity of unmated female and male adults. Both sexes had high total flight activity levels as well as the longest individual flight bouts 2 and 3 d after emergence. The effects of temperature (between 13 and 33 degrees C at 75% RH) and relative humidity (between 30 and 90% RH at 23 degrees C) on the flight activity of 3-d-old unmated adults also were determined. Flight activity declined at the lowest (13 degrees C) and highest (33 degrees C) temperatures tested, as well as at the lowest relative humidity (30% RH). These findings are discussed within the context of selecting the appropriate environmental conditions for releasing C. sinica.

  3. Aging and Curing Temperature Effects on Compressive Strength of Mortar Containing Lime Stone Quarry Dust and Industrial Granite Sludge

    Directory of Open Access Journals (Sweden)

    Muhammad Nasir Amin

    2017-06-01

    Full Text Available In this study, the researchers investigated the potential use of locally available waste materials from the lime stone quarry and the granite industry as a partial replacement of cement. Quarry sites and granite industry in the eastern province of Saudi Arabia produces tons of powder wastes in the form of quarry dust (QD and granite sludge (GS, respectively, causing serious environmental problems along with frequent dust storms in the area. According to ASTM C109, identical 50-mm3 specimens were cast throughout this study to evaluate the compressive strength development of mortars (7, 28 and 91 days containing these waste materials. Experimental variables included different percentage replacement of cement with waste materials (GS, QD, fineness of GS, various curing temperatures (20, 40 and 60 °C as local normal and hot environmental temperatures and curing moisture (continuously moist and partially moist followed by air curing. Finally, the results of mortar containing waste materials were compared to corresponding results of control mortar (CM and mortar containing fly ash (FA. The test results indicated that under normal curing (20 °C, moist cured, the compressive strength of mortar containing the different percentage of waste materials (QD, GS, FA and their combinations remained lower than that of CM at all ages. However, the compressive strength of mortar containing waste materials slightly increased with increased fineness of GS and significantly increased under high curing temperatures. It was recommended that more fineness of GS be achieved to use its high percentage replacement with cement (30% or more incorporating local environmental conditions.

  4. Aging and Curing Temperature Effects on Compressive Strength of Mortar Containing Lime Stone Quarry Dust and Industrial Granite Sludge

    Science.gov (United States)

    Amin, Muhammad Nasir; Khan, Kaffayatullah; Saleem, Muhammad Umair; Khurram, Nauman; Niazi, Muhammad Umar Khan

    2017-01-01

    In this study, the researchers investigated the potential use of locally available waste materials from the lime stone quarry and the granite industry as a partial replacement of cement. Quarry sites and granite industry in the eastern province of Saudi Arabia produces tons of powder wastes in the form of quarry dust (QD) and granite sludge (GS), respectively, causing serious environmental problems along with frequent dust storms in the area. According to ASTM C109, identical 50-mm3 specimens were cast throughout this study to evaluate the compressive strength development of mortars (7, 28 and 91 days) containing these waste materials. Experimental variables included different percentage replacement of cement with waste materials (GS, QD), fineness of GS, various curing temperatures (20, 40 and 60 °C as local normal and hot environmental temperatures) and curing moisture (continuously moist and partially moist followed by air curing). Finally, the results of mortar containing waste materials were compared to corresponding results of control mortar (CM) and mortar containing fly ash (FA). The test results indicated that under normal curing (20 °C, moist cured), the compressive strength of mortar containing the different percentage of waste materials (QD, GS, FA and their combinations) remained lower than that of CM at all ages. However, the compressive strength of mortar containing waste materials slightly increased with increased fineness of GS and significantly increased under high curing temperatures. It was recommended that more fineness of GS be achieved to use its high percentage replacement with cement (30% or more) incorporating local environmental conditions. PMID:28772999

  5. In vitro culture and embryo metabolism of cattle and sheep embryos - a decade of achievement.

    Science.gov (United States)

    Thompson, J G

    2000-07-02

    At the beginning of the 1990s, co-culture of cattle and sheep embryos was the most favoured method to support embryo development, but the use of this system has hampered progress in raising the efficiency of embryo production. Furthermore, little was known of the requirements of embryos and the biochemistry of early embryo development. As the decade progressed, energy metabolism studies improved our understanding of the energy substrate requirements for embryo development. Furthermore, an appreciation of the reproductive tract environment increased. This resulted in more "defined" systems, which have evolved further in the development of "sequential" media systems, where components change in accordance to the needs of the embryo. Nevertheless, wholly defined systems, such as the replacement of albumin with PVA, are less able to support similar levels of development as protein-containing medium, and the resulting embryos are metabolically compromised. This highlights the nutritive role of albumin. One area in which much work has been conducted, but yet no unifying theory has emerged, is that of the interactive roles of growth factors (including autocrine/paracrine), cytokines and extra-cellular matrix molecules in the development of a viable embryo. A new concept is that of regulation of energy metabolism. Compounds such as ethylenediamine tetraacetic acid (EDTA), NaN(3) and 2,4-dinitrophenol have been shown to increase embryo development and quality of resulting embryos. This demonstrates that the process of ATP production is a key regulator of in vitro embryo development.

  6. P63 expression plays a role in developmental rate, embryo size, and local morphogenesis.

    Science.gov (United States)

    Boughner, Julia C; van Eede, Matthijs C; Spring, Shoshana; Yu, Lisa X; Rostampour, Nasim; Henkelman, R Mark

    2018-02-03

    The p63 gene is integral to the development of many body parts including limb, palate, teeth and urogenital tract. Loss of p63 expression may alter developmental rate, which is crucial to normal morphogenesis. To validate a novel, unbiased embryo phenotyping software tool, we tested whether delayed development contributes to the pathological phenotype of a p63 mouse mutant (p63 -/- ). We quantified dysmorphology in p63 -/- embryos and tested for universal growth delay relative to wild type (WT) embryos. Fixed embryos (n=6, p63 -/- ) aged day (E) 15.5 were micro-CT scanned and quantitatively analyzed using a digital WT atlas that defined volumetric differences between p63 -/- and WT embryos. p63 -/- embryos showed a growth delay of about 22 hours (0.9 days). Among the E15.5 mutants, overall size was closest to WT E14.6 mice but shape was closest to WT E14.0. The atlas clearly identified in p63 -/- embryos malformations of epithelial derivatives including limbs, tail, urogenital structures, brain, face and tooth. The software atlas technique described the p63 -/- phenotype as a combination of developmental delay (i.e., heterochrony) and malformation (i.e., pathological shape; failed organogenesis). This study identifies for the first time global and local roles for p63 in prenatal growth and development. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

  7. Cardio-respiratory development in bird embryos: new insights from a venerable animal model

    Directory of Open Access Journals (Sweden)

    Warren W. Burggren

    Full Text Available ABSTRACT The avian embryo is a time-honored animal model for understanding vertebrate development. A key area of extensive study using bird embryos centers on developmental phenotypic plasticity of the cardio-respiratory system and how its normal development can be affected by abiotic factors such as temperature and oxygen availability. Through the investigation of the plasticity of development, we gain a better understanding of both the regulation of the developmental process and the embryo's capacity for self-repair. Additionally, experiments with abiotic and biotic stressors during development have helped delineate not just critical windows for avian cardio-respiratory development, but the general characteristics (e.g., timing and dose-dependence of critical windows in all developing vertebrates. Avian embryos are useful in exploring fetal programming, in which early developmental experiences have implications (usually negative later in life. The ability to experimentally manipulate the avian embryo without the interference of maternal behavior or physiology makes it particularly useful in future studies of fetal programming. The bird embryo is also a key participant in studies of transgenerational epigenetics, whether by egg provisioning or effects on the germline that are transmitted to the F1 generation (or beyond. Finally, the avian embryo is heavily exploited in toxicology, in which both toxicological testing of potential consumer products as well as the consequences of exposure to anthropogenic pollutants are routinely carried out in the avian embryo. The avian embryo thus proves useful on numerous experimental fronts as an animal model that is concurrently both of adequate complexity and sufficient simplicity for probing vertebrate cardio-respiratory development.

  8. Adoption first? The disposition of human embryos.

    Science.gov (United States)

    Murphy, Timothy F

    2014-06-01

    Anja Karnein has suggested that because of the importance of respect for persons, law and policy should require some human embryos created in vitro to be available for adoption for a period of time. If no one comes forward to adopt the embryos during that time, they may be destroyed (in the case of embryos left over from fertility medicine) or used in research (in the case of embryos created for that purpose or left over from fertility medicine). This adoption option would increase the number of embryos available for couples looking for help in having children, but that effect is less important--Karnein argues--than the observance of respect for human persons. As possible persons, she holds that embryos ought to be treated, as if they will become children, if only for a while. If enacted as a matter of law and policy, an 'adoption option' would wrongly interfere with the dispositional rights women and men ought to have over embryos they create in the course of trying to have children. Karnein's proposal would also deprive researchers of certainty that the embryos they create for research would actually be available that way, leading to increased burdens of time and money and maybe even to more embryos than would otherwise be produced. Karnein's analysis does not show, moreover, that any duty of rescue applies to embryos. No woman is required to adopt any embryo, which significantly undercuts the justification for an obligatory adoption period. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. Use of the Coelomic Grafting Technique for Prolonged ex utero Cultivation of Late Preprimitive Streak-Stage Rabbit Embryos.

    Science.gov (United States)

    Püschel, Bernd; Männer, Jörg

    2016-01-01

    Due to its morphological similarity with the early human embryo, the pregastrulation-stage rabbit may represent an appropriate mammalian model for studying processes involved in early human development. The usability of mammalian embryos for experimental studies depends on the availability of whole embryo culture methods facilitating prolonged ex utero development. While currently used culture methods yield high success rates for embryos from primitive streak stages onward, the success rate of extended cultivation of preprimitive streak-stage mammalian embryos is low for all previously established methods and for all studied species. This limits the usability of preprimitive streak-stage rabbit embryos in experimental embryology. We have tested whether the extraembryonic coelom of 4-day-old chick embryos may be used for prolonged ex utero culture of preprimitive streak-stage rabbit embryos (stage 2, 6.2 days post coitum). We found that, within this environment, stage 2 rabbit blastocysts can be cultured at decreasing success rates (55% after 1 day, 35% after 2 days, 15% after 3 days) up to a maximum of 72 h. Grafted blastocysts can continue development from the onset of gastrulation to early organogenesis and thereby form all structures characterizing age-matched controls (e.g. neural tube, somites, beating heart). Compared to normal controls, successfully cultured embryos developed at a slower rate and finally showed some structural and gross morphological anomalies. The method presented here was originally developed for whole embryo culture of mouse embryos by Gluecksohn-Schoenheimer in 1941. It is a simple and inexpensive method that may represent a useful extension to presently available ex utero culture systems for rabbit embryos. © 2016 S. Karger AG, Basel.

  10. 9 CFR 98.16 - The embryo collection unit.

    Science.gov (United States)

    2010-01-01

    ... a table or countertop that is impervious to moisture. The room also must contain a microscope with a minimum of 50x magnification, and equipment for freezing the embryos. (d) Embryo storage area. The embryo...

  11. Daily temperature change in relation to the risk of childhood bacillary dysentery among different age groups and sexes in a temperate city in China.

    Science.gov (United States)

    Li, K; Zhao, K; Shi, L; Wen, L; Yang, H; Cheng, J; Wang, X; Su, H

    2016-02-01

    In recent years, many studies have found that ambient temperature is significantly associated with bacillary dysentery (BD). However, there is limited evidence on the relationship between temperature and childhood BD in temperate areas. To investigate the relationship between daily mean temperature (MT) and childhood BD in China. Data on daily MT and childhood BD between 2006 and 2012 were collected from the Bureau of Meteorology and the Centre for Disease Control and Prevention in Hefei, Anhui Province, China. A Poisson generalized linear regression model combined with a distributed lag non-linear model was used to analyse the effects of temperature on childhood BD across different age and sex subgroups. An increase in temperature was significantly associated with childhood BD, and each 1 °C increase corresponded to an increase of 1.58% [95% confidence interval (CI) 0.46-2.71%] in the number of cases of BD. Children aged 0-5 years and girls were particularly sensitive to the effects of temperature. High temperatures may increase the risk of childhood BD in Hefei. Children aged 0-5 years and girls appear to be particularly sensitive to the effects of high temperature. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  12. Dependency of seed dormancy types on embryo traits and environmental conditions in Ribes species.

    Science.gov (United States)

    Mattana, E; Stuppy, W H; Fraser, R; Waller, J; Pritchard, H W

    2014-07-01

    The hypothesis that seed dormancy may be dependent on environmental conditions and seed morphological traits was tested for six Ribes species, across an altitudinal gradient of 1300 m and a longitudinal separation of 120°. Embryo measurements and seed germination experiments were conducted for R. alpinum L., R. hudsonianum Richardson var. petiolare (Douglas) Jancz., R. nevadaense Kellogg, R. roezlii Regel var. cruentum (Greene) Rehder and R. speciosum Pursh, and data taken from the literature for R. multiflorum Kit. ex Schult. ssp. sandalioticum Arrigoni. Germination was compared with seed viability to reveal proportional seed dormancy, which was then correlated to seed/embryo morphological traits and these traits related to the seed provenance environment. The embryos of all the investigated species are linear underdeveloped and all had a morphological component of seed dormancy (MD). Seeds of R. roezlii, R. hudsonianum and R. nevadaense required a temperature and/or hormone pre-treatment in order to germinate, highlighting morphophysiological seed dormancy (MPD). Seed dormancy was found to be strongly negatively correlated with embryo length, but not with embryo to seed (E:S) ratio or seed mass. Initial embryo length was positively related to mean annual temperature. Seed dormancy in the investigated Ribes species could be quantified and predicted by the interaction of embryo traits and environmental conditions. This approach may be helpful in assessing and predicting seed dormancy in the Ribes genus and in other genera and families with underdeveloped embryos. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  13. Radionuclide Exposure of the Embryo/Fetus

    Energy Technology Data Exchange (ETDEWEB)

    Blundell, Helen

    1999-06-01

    This report addresses the determination of radiation dose to the embryo (the conceptus from fertilisation to organogenesis) and the fetus (post-organogenesis to birth) from radionuclides that are present in the woman before her pregnancy or that enter her during her pregnancy. This exposure may be via nuclear medicine procedures, occupational exposures or environmental sources that may affect the general population. The effects of radiation on the embryo/fetus are greatly influenced by the dependence on stage of gestation, which affects the transfer of radioactivity from the pregnant woman to the fetoplacental system, the distribution of the activity and the developmental effects of the resulting radiation absorbed doses. A chapter is therefore devoted to a detailed discussion of development of the embryo/fetus through the stages of pre-implantation, implantation and post-implantation development and the fetal period. To an non-expert the anatomical detail and nomenclature are rather difficult, but diagrams are clear and well labelled and a useful glossary of terms is provided. Mechanisms of maternal-fetal exchange and the effects of the maternal organs and placenta as external sources of radiation are then discussed, though it is stressed here - as throughout the report - that most information about the distribution and retention of materials during pregnancy has been obtained from studies in experimental animals. Extrapolation of animal data to humans is difficult and potentially inaccurate. The effects of prenatal irradiation are categorised as early, delayed and late effects. Early effects are further divided into the pre-implantation period (blastogenesis), period of organ formation (organogenesis) and period of the fetus (fetogenesis). Chapters 7 and 8 deal with compartmental modelling, dosimetry and estimation of embryo/fetus dose in radiation protection practice. The ICRP and MIRD methodologies are discussed, both of which differentiate source and target

  14. Developmental stages in human embryos: revised and new measurements.

    Science.gov (United States)

    O'Rahilly, Ronan; Müller, Fabiola

    2010-01-01

    The staging of human embryos, as distinct from seriation, depends on a morphological scheme devised by Streeter and completed by O'Rahilly, who proposed the term Carnegie stages. To avoid misconceptions and errors, and to place new findings in perspective, it is necessary to summarize the essentials of the Carnegie system: (1) Twenty-three stages cover the embryonic period, i. e. the first 8 postfertilizational weeks of development. (2) The system is based on internal as well as external features, and the use of only external criteria is subject to serious limitations. For example, precise delineation of stages 19-23 and of the embryonic-fetal transition depends on histological examination. (3) Prenatal measurements are not an integral component of the staging system, and hence a stage should never be assigned merely on the basis of embryonic length. A 20-mm embryo, for example, could belong to any of three stages. Measurements, however, are important for the assessment of age, and very few measurements are available for staged embryos. Presented here and based on accurate staging are the maximum diameter of the chorionic sac, the crown-heel length, the greatest length exclusive of the lower limbs, the biparietal diameter, the head circumference, the length of the hindbrain, the total length of the brain, and the lengths of the limbs as well as of their segments, including the foot length. (4) Prenatal ages are also not an integral part of the staging system and hence a stage should never be assigned merely on the basis of prenatal age. Ages, however, are of clinical importance and their estimate has been rendered more precise by accurate timing of fertilization followed by ultrasonography. Prenatal age is postfertilizational and hence some 2 weeks less than the postmenstrual interval. The term gestational age is ambiguous and should be discarded. Presented here is a new graph showing proposed estimates of age in relation to stages and based on current information

  15. Interspecies embryo reconstruction in Tibetan antelope Pantholops ...

    African Journals Online (AJOL)

    user

    2011-03-21

    Mar 21, 2011 ... Interspecies implantation and mitochondria fate of panda-rabbit cloned embryos. Biol. Reprod. 67: 637-642. Dominko T, Ramalho-Santos J, Chan A, Moreno R, Luetjens C, Simerly. C, Hewitson L, Takahashi D, Martinovich C, White J (1999). Optimization strategies for production of mammalian embryos by.

  16. Human stem cell ethics: beyond the embryo.

    Science.gov (United States)

    Sugarman, Jeremy

    2008-06-05

    Human embryonic stem cell research has elicited powerful debates about the morality of destroying human embryos. However, there are important ethical issues related to stem cell research that are unrelated to embryo destruction. These include particular issues involving different types of cells used, the procurement of such cells, in vivo use of stem cells, intellectual property, and conflicts of interest.

  17. Embryo transfer using cryopreserved Boer goat blastocysts ...

    African Journals Online (AJOL)

    The aim of this trial was to evaluate the effect of embryo cryopreservation techniques on the survivability of embryos and fertility following transfer to Boer goat does. The oestrous cycles of 27 mature recipients Boer goat does were synchronised using controlled internal drug release dispensers (CIDR's) for 16 days. At CIDR ...

  18. Alcohol consumption and quality of embryos obtained in programmes of in vitro fertilization

    Directory of Open Access Journals (Sweden)

    Artur Wdowiak

    2014-06-01

    Full Text Available introduction. Infertility is defined as a state when a couple fails to conceive a pregnancy after one year of regular intercourse without the use of contraception. Alcohol consumption is one of the main stimulants which negatively affect the female and male reproductive system. objective. The objective of the study was analysis of the effect of alcohol consumption by the examined women on the quality of embryos obtained during in vitro fertilization programmes. material and methods. The study covered 54 women who received treatment due to infertility. The database and statistical analyses were performed using computer software STATISTICA 7.1 (StatSoft, Poland. results. The study showed that 42.59% from among 100% of the women in the study consumed alcohol. In the group of women who consumed alcohol, class A embryos constituted 4.35%, class B embryos – 86.96%, while embryos of class C – 8.69%. A statistically significant difference was observed between the classes of embryos and alcohol consumption by the women examined (p=0.001. In addition, a statistically significant relationship was found between the amount of alcohol consumed and the classes of embryos (p=0.005. A significantly larger number of class B embryos came from women who consumed more than 25 grams of ethyl alcohol daily (72.72%, compared to those who consumed alcohol sporadically (44.44%, or those who abstained entirely from alcohol (30.00%. conclusions. Alcohol consumption causes the development of poorer quality embryos. Significantly more embryos of class B came from oocytes of women who consumed alcohol, compared to class A. An active campaign against alcohol consumption should be carried out among women at reproductive age to safeguard their fertility and future motherhood.

  19. Rape embryogenesis. III. Embryo development in time

    Directory of Open Access Journals (Sweden)

    Teresa Tykarska

    2014-01-01

    Full Text Available It was found that the growth curve of the rape embryo axis is of triple sigmoid type. Embryo growth occurs in 3 phases corresponding to 3 different periods of development. Phase I includes growth of the apical cell up to it's division into two layers of octants. Phase II comprises the increase of the spherical proembryo to the change of its symmetry from radial to bilateral. Phase III includes, growth of the embryo from the heart stage up to the end of embryogenesis. In each phase the relative growth rate increases drastically and then diminishes. The differences in growth intensity during the same phase are several-fold. The growth intensity maximum of the embryo axis occurs in phase II. The phasic growth intensity maxima occur: in phase I during apical cell elongation, :before its division, and in phases II and III in the periods of cell division ;growth in globular and torpedo-shaped -shaped embryos.

  20. Nucleolar ultrastructure in bovine nuclear transfer embryos

    DEFF Research Database (Denmark)

    Kaňka, Jiří; Smith, Steven Dale; Soloy, Eva

    1999-01-01

    (nonactivated) or S phase (activated) cytoplasts. Control embryos were fixed at the two-, four-, early eight- and late eight-cell stages; nuclear transfer embryos were fixed at 1 and 3 hr post fusion and at the two-, four-, and eight-cell stages. Control embryos possessed a nucleolar precursor body throughout...... at 1 hr after fusion and, by 3 hr after fusion, it was restored again. At this time, the reticulated fibrillo-granular nucleolus had an almost round shape. The nucleolar precursor body seen in the two-cell stage nuclear transfer embryos consisted of intermingled filamentous components and secondary...... time intervals after fusion. In the two-cell stage nuclear transfer embryo, the originally reticulated nucleolus of the donor blastomere had changed into a typical nucleolar precursor body consisting of a homogeneous fibrillar structure. A primary vacuole appeared in the four-cell stage nuclear...

  1. Embryo transfer in domestic South American camelids.

    Science.gov (United States)

    Sumar, Julio B

    2013-01-10

    Intraspecific and interspecific embryo transfer in domestic South American camelids is developing into a well-established technique. Reports reveal many benefits of using reproductive biotechnologies to allow rapid propagation of alpacas and llamas of high genetic merit (e.g., high fiber quality, preserve color variation). The objective of this review is to provide up-to-date information about embryo transfer in domestic South American camelids. Specific information is provided on criteria for male selection, donor and recipient synchronization, the practice of single- vs. super-ovulation protocols, embryo recovery and transfer techniques, advances in cryopreservation of embryos, results of intra- and inter-specific transfer, and the future of the embryo transfer in domestic South American camelids. Copyright © 2012. Published by Elsevier B.V.

  2. Noninvasive metabolomic profiling as an adjunct to morphology for noninvasive embryo assessment in women undergoing single embryo transfer

    NARCIS (Netherlands)

    Seli, E.; Vergouw, C.G.; Morita, H.; Botros, L.; Roos, P.; Lambalk, C.B.; Yamashita, N.; Kato, O.; Sakkas, D.

    2010-01-01

    Objective: To determine whether metabolomic profiling of spent embryo culture media correlates with reproductive potential of human embryos. Design: Retrospective study. Setting: Academic and a private assisted reproductive technology (ART) programs. Patient(s): Women undergoing single embryo

  3. L10 ordered structures in Al-Cu-(Mg alloys at the early stages of elevated temperature aging

    Directory of Open Access Journals (Sweden)

    Fuzhong, Xia

    2016-09-01

    Full Text Available This study concerns the precipitation structures of Al-3Cu and Al-3Cu-1.78Mg (wt. % alloys at the early stages of elevated temperature aging. The Al-3Cu and Al-3Cu-1.78 Mg alloys were solution treated at 540 °C and 500 °C for 2 h, respectively, and then aged at 190 °C for 2 min. The precipitation structures in aged Al-3Cu-(1.78Mg alloys were characterized by Transmission Electron Microscopy (TEM and High Resolution Transmission Electron Microscopy (HTREM. 001 zone axis Selected area electron diffraction patterns indicate that L10 ordered structures are formed in the two aged alloys. HRTEM experiments reveal the partial dislocations on the interfaces of L10 ordered structures. From comparing experimental results with that in the literature, it is concluded that the L10 ordered structures in aged Al-3Cu alloy consist of Al and Cu atoms, and they are comprised by Al, Cu and Mg atoms together in the aged Al-3Cu-1.78Mg alloy. On the basis of precipitate growing thermodynamics, it is thought the L10 ordered structures act as nuclei for GP zones in Al-Cu-(Mg alloys during aging.En este trabajo se estudian las estructuras de precipitación en Al-3Cu y Al-3Cu-1,78Mg (% en peso en los estados iniciales de envejecimiento a temperatura elevada. Las aleaciones Al-3Cu y Al-3Cu-1.78 Mg fueron sometidas a un tratamiento térmico de solución de 2 h a 540 °C y 500 °C, respectivamente, y posteriormente envejecidas 2 min a 190 °C. Las estructuras de precipitación en Al-3Cu-(1.78Mg envejecido fueron caracterizadas por microscopía electrónica de transmisión (TEM y por microscopía electrónica de transmisión de alta resolución (HTREM. Los diagramas de difracción de electrones de área seleccionada indican que se forman estructuras ordenadas L10 en las dos aleaciones envejecidas. Experimentos de HRTEM revelan la presencia de dislocaciones parciales en las intercaras de las estructuras L10 ordenadas. Comparando estos resultados experimentales con la

  4. Assisted reproduction technique outcomes for fresh versus deferred cryopreserved day-2 embryo transfer: a retrospective matched cohort study.

    Science.gov (United States)

    Bourdon, Mathilde; Santulli, Pietro; Gayet, Vanessa; Maignien, Chloé; Marcellin, Louis; Pocate-Cheriet, Khaled; Chapron, Charles

    2017-03-01

    Ovarian stimulation could adversely affect endometrial receptivity and consequently embryo implantation. One emerging strategy is the 'freeze-all' approach. Most studies have focused on blastocyst transfers, with limited research on day-2 deferred cryopreserved embryo transfers. In this large retrospective cohort study, outcomes were compared between day-2 fresh versus deferred cryopreserved embryo transfers. After matching by age and number of previous cycles, 325 cycles were included in the fresh group and 325 in the deferred cryopreserved embryo transfers group: no significant differences were found between groups in implantation (0.20 ± 0.33 versus 0.17 ± 0.31, respectively) and ongoing pregnancy rates (21.85% versus 18.46%). Independent predictors for ongoing pregnancy after a multiple logistic regression analysis were the women's age (OR = 0.92; 95% CI 0.88 to 0.97), body mass index (OR = 0.94; 95% CI 0.89 to 0.99), the number of two pronuclei embryos (OR = 1.19; 95% CI 1.04 to 1.40) and at least one grade 1 embryo transferred (OR = 1.97; 95% CI 1.26 to 3.05). In the case of a day-2 embryo transfer, outcomes after treatment with assisted reproduction techniques are similar for fresh versus deferred cryopreserved embryo transfers when pre-transfer progesterone exposures are similar in the two groups. Copyright © 2016 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  5. Potential of human twin embryos generated by embryo splitting in assisted reproduction and research.

    Science.gov (United States)

    Noli, Laila; Ogilvie, Caroline; Khalaf, Yacoub; Ilic, Dusko

    2017-03-01

    Embryo splitting or twinning has been widely used in veterinary medicine over 20 years to generate monozygotic twins with desirable genetic characteristics. The first human embryo splitting, reported in 1993, triggered fierce ethical debate on human embryo cloning. Since Dolly the sheep was born in 1997, the international community has acknowledged the complexity of the moral arguments related to this research and has expressed concerns about the potential for reproductive cloning in humans. A number of countries have formulated bans either through laws, decrees or official statements. However, in general, these laws specifically define cloning as an embryo that is generated via nuclear transfer (NT) and do not mention embryo splitting. Only the UK includes under cloning both embryo splitting and NT in the same legislation. On the contrary, the Ethics Committee of the American Society for Reproductive Medicine does not have a major ethical objection to transferring two or more artificially created embryos with the same genome with the aim of producing a single pregnancy, stating that 'since embryo splitting has the potential to improve the efficacy of IVF treatments for infertility, research to investigate the technique is ethically acceptable'. Embryo splitting has been introduced successfully to the veterinary medicine several decades ago and today is a part of standard practice. We present here an overview of embryo splitting experiments in humans and non-human primates and discuss the potential of this technology in assisted reproduction and research. A comprehensive literature search was carried out using PUBMED and Google Scholar databases to identify studies on embryo splitting in humans and non-human primates. 'Embryo splitting' and 'embryo twinning' were used as the keywords, alone or in combination with other search phrases relevant to the topics of biology of preimplantation embryos. A very limited number of studies have been conducted in humans and non

  6. Spectroscopic analysis of embryo culture media for predicting reproductive potential in patients undergoing in vitro fertilization.

    Science.gov (United States)

    Baştu, Ercan; Parlatan, Uğur; Başar, Günay; Yumru, Harika; Bavili, Nima; Sağ, Fatih; Bulgurcuoğlu, Sibel; Buyru, Faruk

    2017-09-01

    To predict the reproductive potential of embryos via Raman spectroscopy evaluation of the spent culture media as well as with a conventional morphologic evaluation. Women of reproductive age (n=31) who were treated for unexplained infertility and scheduled for single embryo transfer were invited to participate in this prospective study. After the embryos were removed from the culture, the spent culture media were stored at -80 °C after snap-freezing in liquid nitrogen. Fifteen patients were clinically pregnant, and 16 patients were clinically non-pregnant. Clinical pregnancy was predicted using Raman spectroscopy in 93% (14/15) of clinically pregnant patients, and in 62.5% (10 out of 16) of clinically non-pregnant patients. The sensitivity of the Raman spectroscopic analysis was 93% and the specificity was 62.5%. Metabolomic evaluation of spent embryo culture media is an emerging technique with promising objective results. However, there is clearly room for improvement.

  7. Interlaboratory evaluation of embryotoxicity in the postimplantation rat embryo culture.

    Science.gov (United States)

    Piersma, A H; Attenon, P; Bechter, R; Govers, M J; Krafft, N; Schmid, B P; Stadler, J; Verhoef, A; Verseil, C

    1995-01-01

    The embryotoxicity of eight xenobiotic compounds in rat postimplantation whole embryo culture was blindly tested in four laboratories according to a standard protocol. The results show that the four nonteratogens amaranth, penicillin, isoniazid, and saccharin did not affect embryogenesis apart from general toxicity at very high concentrations in culture for amaranth and isoniazid. There was good concordance of results across the laboratories. The four teratogens (retinoic acid, 6-aminonicotinamide, acetylsalicylic acid, and vincristine) induced a variety of specific embryotoxic effects, which were in most cases similar in all laboratories. These results indicate that the definition for specific embryotoxicity used, as well as the culture duration and embryonic age are crucial for concordant scoring. Other methodologic differences did not significantly influence scoring of embryotoxicity. Therefore, within the limits of the end points and embryonic stage represented in the method, embryo culture appears as a useful method for embryotoxicity screening, which can be reproducibly applied in different laboratories.

  8. The effects of embryo culture media on the birthweight of singletons via fresh or frozen-thawed embryo transfer: a large-scale retrospective study.

    Science.gov (United States)

    Gu, Fang; Deng, Mingfen; Gao, Jun; Wang, Zilian; Ding, Chenhui; Xu, Yanwen; Zhou, Canquan

    2016-09-19

    Embryo culture media used for IVF treatment might affect fetal growth and thus birthweight of the newborns. A retrospective study was conducted in South China using data from 2370 singleton neonates born after IVF/ICSI between 2009 and 2012. Two culture media, i.e., either Vitrolife or SAGE were used as embryo culture media during the study period. Neonates' birthweights were compared between the two embryo culture media groups. Among the 2370 singletons, 1755 cases came from fresh cleavage embryo transfer while 615 were from frozen-thawed cleavage embryo transfer. Within the fresh embryo transfer newborns, no statistical difference was observed in either birthweight (mean ± SD: 3196.0 ± 468.9 versus 3168.4 ± 462.0g, p > 0.05) or adjusted birthweight controlled for gestational age and gender (z-score mean ± SD: 0.11 ± 1.02 versus 0.11 ± 0.99 g, P > 0.05) between the Vitrolife (n = 419) and the SAGE group (n = 1336). Likewise within frozen embryo transfer neotates, no statistical difference of the birthweight (3300.6 ± 441.3 vs.3256.0 ± 466.7 g, P > 0.05) and adjusted birthweight (0.30 ± 0.99 g versus 0.29 ± 0.97 g, P > 0.05) was found between the Vitrolife (n = 202) and the SAGE group (n = 413). The sex ratio [OR1.17, 95 % CI (0.94-1.46)/OR1.1, 95 % CI (0.78-1.54)], rate of small for gestational age [OR1.14, 95 % CI (0.82-1.59)/OR1.06, 95 % CI (0.56-2.02)] and large for gestational age [OR1.07, 95 % CI (0.64-1.76)/OR0.98, 95 % CI (0.47-2.02)] in fresh and frozen-thawed subgourps are all comparable respectively between the two culture media. No group differences were found in the rate of low birthweight and macosomia. Multiple linear regression analysis demonstrated that maternal weight, gestational age, frozen-thawed embryo transfer and infant gender were significantly related to neonatal birthweight (P cultured in SAGE or Vitrolife media after fresh or frozen-thawed cleavage

  9. Effect of extreme sea surface temperature events on the demography of an age-structured albatross population.

    Science.gov (United States)

    Pardo, Deborah; Jenouvrier, Stéphanie; Weimerskirch, Henri; Barbraud, Christophe

    2017-06-19

    Climate changes include concurrent changes in environmental mean, variance and extremes, and it is challenging to understand their respective impact on wild populations, especially when contrasted age-dependent responses to climate occur. We assessed how changes in mean and standard deviation of sea surface temperature (SST), frequency and magnitude of warm SST extreme climatic events (ECE) influenced the stochastic population growth rate log(λs) and age structure of a black-browed albatross population. For changes in SST around historical levels observed since 1982, changes in standard deviation had a larger (threefold) and negative impact on log(λs) compared to changes in mean. By contrast, the mean had a positive impact on log(λs). The historical SST mean was lower than the optimal SST value for which log(λs) was maximized. Thus, a larger environmental mean increased the occurrence of SST close to this optimum that buffered the negative effect of ECE. This 'climate safety margin' (i.e. difference between optimal and historical climatic conditions) and the specific shape of the population growth rate response to climate for a species determine how ECE affect the population. For a wider range in SST, both the mean and standard deviation had negative impact on log(λs), with changes in the mean having a greater effect than the standard deviation. Furthermore, around SST historical levels increases in either mean or standard deviation of the SST distribution led to a younger population, with potentially important conservation implications for black-browed albatrosses.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

  10. Positron annihilation lifetime spectroscopy study on the structural relaxation of phenylmethylsiloxane-modified epoxy hybrids at different aging temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Chia-Wen [Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan (China); Ma, Chen-Chi M., E-mail: ccma@che.nthu.edu.tw [Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Tan, Chung-Sung [Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Li, Hsun-Tien [Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan (China)

    2015-07-15

    The cured network conformations and structural relaxation behaviours of the diglycidyl ether of bisphenol A (DGEBA)-methylhexahydrophthalic anhydride (MHHPA) modified with phenylmethylsiloxane-modified epoxy (PMSE) at different aging temperatures were studied using dynamic mechanical analysis (DMA) and positron annihilation lifetime spectroscopy (PALS). The DMA results revealed that the cured PMSE network can insert into the cured DGEBA network to form interpenetrating polymer networks (IPNs). The structural relaxation behaviours of DGEBA–PMSE-0.4 produced using DGEBA, PMSE, and MHHPA at a ratio of 0.6:0.4:1 by equivalent weight were studied using PALS at 150 °C and 55 °C. The aging-induced free volume relaxation parameters of DGEBA–PMSE-0.4 at 150 °C and 55 °C were investigated using the double additive exponential model and the Kohlrausch–Williams–Watts exponential model. For double additive exponential model, only one relaxation time (ζ) of 584.5 h was found at 150 °C; By contrast, there were two separate relaxation times of 37.4 h (ζ{sub 1}) and 753.6 h (ζ{sub 2}) at 55 °C. The ζ{sub 1} of the IPNs hybrid can be attributed to the network relaxation of PMSE, and the ζ{sub 2} can be attributed to the network relaxation of DGEBA at 55 °C. The results suggested the double additive exponential model can effectively predict DGEBA–PMSE hybrid relaxation behaviours. - Highlights: • The cured network conformations of DGEBA–PMSE hybrids were studied using DMA. • The structural relaxation behaviours of DGEBA–PMSE hybrids were studied using PALS. • The cured DGEBA–PMSE hybrids were interpenetrating polymer networks (IPNs). • PALS studies provided a quantitative demonstration of relaxation behaviours. • Double additive exponential model effectively predicted the relaxation times of hybrids.

  11. Chilling curves for Piaractus mesopotamicus (Holmberg, 1887) embryos stored at -8°C.

    Science.gov (United States)

    Lopes, Taís da S; Streit, Danilo Pedro; Fornari, Darci Carlos; de Oliveira, Diego; Ribeiro, Ricardo Pereira; Romagosa, Elizabeth

    2013-11-01

    The present study investigates the effect of different slow chilling curves on the storage of pacu (Piaractus mesopotamicus) embryos submitted to chilling at -8°C. Embryos at the blastopore closure stage were divided into two groups: G1 - embryos exposed to cryoprotectant solution containing methanol (10%) and sucrose (0.5 M), treated as follows: (T1) taken directly from room temperature to the refrigerator without being submitted to the curve; (T2) chilling curve of 0.5°C/min; and (T3) chilling curve of 1°C/min; and G2 - the cryoprotectant solution alone was submitted to these same temperatures, receiving the embryos only after temperature had decreased, corresponding to treatments T4, T5 and T6, respectively. Treatments were kept at -8°C for a period of 6 h. Embryo development was evaluated for each treatment, with six replicates in an entirely randomized design. Survival among embryos not submitted to refrigeration was 94.3 ± 8.05%. Percentage of total larvae (TL) and addled eggs (AE) did not differ statistically between the groups, although percentage of swimming larvae (SL) exhibited higher values in G1 for the 1°C/min curve. Furthermore, when comparing the three chilling curves, a decrease of 1°C/min resulted in the highest TL percentage (90.85%), followed by the 0.5°C/min curve (78.52%). Thus, the use of 1°C/min chilling curves is recommended for P. mesopotamicus embryos stored for 6 h at -8°C.

  12. The effects of genetic line (broilers vs. layers) on embryo development.

    Science.gov (United States)

    Druyan, S

    2010-07-01

    Recent decades were characterized by genetic selection of broiler and layer chickens for enhanced growth rate and meat yield or intensified egg production, respectively. It is to be expected that genetic selection for various traits would also influence embryo development and growth patterns that affect metabolism. The objective of the present study was to examine the effects of broiler (Cobb and Ross) and layer (Lohmann) lines and parent flock age (31 and 38 wk) on embryonic development, heart rate, O2 consumption, and blood parameters. For each line, 2 incubation sets, from flocks aged 31 and 38 wk, with 500 eggs per set, were studied. Development patterns differed between layers and broilers: layers hatched 1 d later and their relative embryonic weight at hatch was significantly lower, probably because of their longer period until hatch, although yolk relative weights were similar. Oxygen consumption of layer embryos was lower than that of broilers, and plasma triiodothyronine concentration, hematocrit, and hemoglobin levels were lower in layers than in broilers. However, layer embryo heart rate was higher from embryonic d (E) 15 onward. Differences were found between the Ross and Cobb lines in embryonic development. Oxygen consumption of Ross embryos was slightly higher than that of Cobb from E16 to E19. Heart rate of Ross embryos was significantly higher than that of Cobb. Furthermore, plasma triiodothyronine concentration of Ross embryos was significantly higher on E14, E16, and hatch. These differences suggest that the genetic selection for rapid growth rate in the 2 broiler lines did not cause differences between their embryonic growth patterns, but it did affect their metabolic rate. Oxygen consumption was higher in embryos from the 38-wk-old flock. The results suggest that genetic selection affected not only production traits but also the developmental pattern of the embryo and its metabolic characteristics.

  13. Embryo cryopreservation and preeclampsia risk.

    Science.gov (United States)

    Sites, Cynthia K; Wilson, Donna; Barsky, Maya; Bernson, Dana; Bernstein, Ira M; Boulet, Sheree; Zhang, Yujia

    2017-11-01

    To determine whether assisted reproductive technology (ART) cycles involving cryopreserved-warmed embryos are associated with the development of preeclampsia. Retrospective cohort study. IVF clinics and hospitals. A total of 15,937 births from ART: 9,417 singleton and 6,520 twin. We used linked ART surveillance, birth certificate, and maternal hospitalization discharge data, considering resident singleton and twin births from autologous or donor eggs from 2005-2010. We compared the frequency of preeclampsia diagnosis for cryopreserved-warmed versus fresh ET and used multivariable logistic regression to adjust for confounders. Among pregnancies conceived with autologous eggs resulting in singletons, preeclampsia was greater after cryopreserved-warmed versus fresh ET (7.51% vs. 4.29%, adjusted odds ratio = 2.17 [95% CI 1.67-2.82]). Preeclampsia without and with severe features, preeclampsia with preterm delivery, and chronic hypertension with superimposed preeclampsia were more frequent after cryopreserved-warmed versus fresh ET (3.99% vs. 2.55%; 2.95% vs. 1.41%; 2.76 vs. 1.48%; and 0.95% vs. 0.43%, respectively). Among pregnancies from autologous eggs resulting in twins, the frequency of preeclampsia with severe features (9.26% vs. 5.70%) and preeclampsia with preterm delivery (14.81% vs. 11.74%) was higher after cryopreserved versus fresh transfers. Among donor egg pregnancies, rates of preeclampsia did not differ significantly between cryopreserved-warmed and fresh ET (10.78% vs. 12.13% for singletons and 28.0% vs. 25.15% for twins). Among ART pregnancies conceived using autologous eggs resulting in live births, those involving transfer of cryopreserved-warmed embryos, as compared with fresh ETs, had increased risk for preeclampsia with severe features and preeclampsia with preterm delivery. Copyright © 2017 American Society for Reproductive Medicine. All rights reserved.

  14. The effects of summer temperature, age and socioeconomic circumstance on Acute Myocardial Infarction admissions in Melbourne, Australia

    Directory of Open Access Journals (Sweden)

    Tapper Nigel J

    2010-08-01

    Full Text Available Abstract Background Published literature detailing the effects of heatwaves on human health is readily available. However literature describing the effects of heat on morbidity is less plentiful, as is research describing events in the southern hemisphere and Australia in particular. To identify susceptible populations and direct public health responses research must move beyond description of the temperature morbidity relationship to include social and spatial risk factors. This paper presents a spatial and socio-demographic picture of the effects of hot weather on persons admitted to hospital with acute myocardial infarction (AMI in Melbourne. Results In this study, the use of a spatial and socio-economic perspective has identified two groups within the population that have an increased 'risk' of AMI admissions to hospital during hot weather. AMI increases during hot weather were only identified in the most disadvantaged and the least disadvantaged areas. Districts with higher AMI admissions rates during hot weather also had larger proportions of older residents. Age provided some explanation for the spatial distribution of AMI admissions on single hot days whereas socio-economic circumstance did not. During short periods (3-days of hot weather, age explained the spatial distribution of AMI admissions slightly better than socioeconomic circumstance. Conclusions This study has demonstrated that both age and socioeconomic inequality contribute to AMI admissions to hospital in Melbourne during hot weather. By using socioeconomic circumstance to define quintiles, differences in AMI admissions were quantified and demographic differences in AMI admissions were described. Including disease specificity into climate-health research methods is necessary to identify climate-sensitive diseases and highlight the burden of climate-sensitive disease in the community. Cardiac disease is a major cause of death and disability and identifying cardiac

  15. [Association of human chorionic gonadotropin level in embryo culture media with early embryo development].

    Science.gov (United States)

    Wang, Haiying; Zhang, Renli; Han, Dong; Liu, Caixia; Cai, Jiajie; Bi, Yanling; Wen, Anmin; Quan, Song

    2014-06-01

    To investigate the association of human chorionic gonadotropin (HCG) level on day 3 of embryo culture with embryo development. Spent culture media were collected from individually cultured embryos on day 3 of in vitro fertilization and embryo transfer (IVF-ET) cycles. HCG concentration in the culture media was measured using an ELISA kit and its association with embryo development was assessed. In the 163 samples of embryo culture media from 60 patients, HCG was positive in 153 sample (93.8%) with a mean level of 0.85 ± 0.43 mIU/ml. The concentration of hCG in the culture media increased gradually as the number of blastomeres increased (F=2.273, P=0.03), and decreased as the morphological grade of the embryo was lowered (F=3.900, P=0.02). ELISA is capable of detecting HCG levels in spent culture media of embryos on day 3 of in vitro culture. The concentration of HCG in spent culture media is positively correlated with the status of early embryo development and implantation rate and thus serves as a useful marker for embryo selection in IVF-ET procedure.

  16. Dynamin regulates metaphase furrow formation and plasma membrane compartmentalization in the syncytial Drosophila embryo

    Directory of Open Access Journals (Sweden)

    Richa Rikhy

    2015-02-01

    Full Text Available The successive nuclear division cycles in the syncytial Drosophila embryo are accompanied by ingression and regression of plasma membrane furrows, which surround individual nuclei at the embryo periphery, playing a central role in embryo compartmentalization prior to cellularization. Here, we demonstrate that cell cycle changes in dynamin localization and activity at the plasma membrane (PM regulate metaphase furrow formation and PM organization in the syncytial embryo. Dynamin was localized on short PM furrows during interphase, mediating endocytosis of PM components. Dynamin redistributed off ingressed PM furrows in metaphase, correlating with stabilized PM components and the associated actin regulatory machinery on long furrows. Acute inhibition of dynamin in the temperature sensitive shibire mutant embryo resulted in morphogenetic consequences in the syncytial division cycle. These included inhibition of metaphase furrow ingression, randomization of proteins normally polarized to intercap PM and disruption of the diffusion barrier separating PM domains above nuclei. Based on these findings, we propose that cell cycle changes in dynamin orchestrate recruitment of actin regulatory machinery for PM furrow dynamics during the early mitotic cycles in the Drosophila embryo.

  17. Toward embedded laboratory automation for smart Lab-on-a-Chip embryo arrays.

    Science.gov (United States)

    Wang, Kevin I-Kai; Salcic, Zoran; Yeh, Johnny; Akagi, Jin; Zhu, Feng; Hall, Chris J; Crosier, Kathryn E; Crosier, Philip S; Wlodkowic, Donald

    2013-10-15

    Lab-on-a-Chip (LOC) biomicrofluidic technologies are rapidly emerging bioanalytical tools that can miniaturize and revolutionize in situ research on embryos of small vertebrate model organisms such as zebrafish (Danio rerio) and clawed African frog (Xenopus laevis). Despite considerable progress being made in fabrication techniques of chip-based devices, they usually still require excessive and manual actuation and data acquisition that significantly reduce throughput and introduce operator-related analytical bias. This work describes the development of a proof-of-concept embedded platform that integrates an innovative LOC zebrafish embryo array technology with an electronic interface to provide higher levels of laboratory automation for in situ biotests. The integrated platform was designed to perform automatic immobilization, culture and treatment of developing zebrafish embryos during fish embryo toxicity (FET) biotests. The system was equipped with a stepper motor driven stage, solenoid-actuated pinch valves, miniaturized peristaltic pumps as well as Peltier heating module. Furthermore, a Field Programmable Gate Array (FPGA) was used to implement an embedded hardware/software solution and interface to enable real-time control over embryo loading and immobilization; accurate microfluidic flow control; temperature stabilization and also automatic time-resolved image acquisition of developing zebrafish embryos. This work presents evidence that integration of embedded electronic interfaces with microfluidic chip-based technologies can bring the Lab-on-a-Chip a step closer to fully automated analytical systems. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Glassfrog embryos hatch early after parental desertion.

    Science.gov (United States)

    Delia, Jesse R J; Ramírez-Bautista, Aurelio; Summers, Kyle

    2014-06-22

    Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations.

  19. Nucleolar remodeling in nuclear transfer embryos

    DEFF Research Database (Denmark)

    Laurincik, Jozef; Maddox-Hyttel, Poul

    2007-01-01

    Transcription of the ribosomal RNA (rRNA) genes occurs in the nucleolus and results in ribosome biogenesis. The rRNA gene activation and the associated nucleolus formation may be used as a marker for the activation of the embryonic genome in mammalian embryos and, thus serve to evaluate the devel...... reprogramming and may help to explain the abnormalities observed in a proportion of fetuses and offspring derived from nuclear transfer embryos....... the developmental potential of embryos originating from varied nuclear transfer protocols. In bovine in vivo developed embryos, functional ribosome-synthesizing nucleoli become structurally distinct toward the end of the 4th post-fertilization cell cycle. In embryonic cell nuclear transfer embryos, fully developed...... nucleoli are not apparent until the 5th cell cycle, whereas in somatic cell nuclear transfer embryos the functional nucleoli emerge already during the 3rd cell cycle. Intergeneric reconstructed embryos produced by the fusion of bovine differentiated somatic cell to a nonactivated ovine cytoplast fail...

  20. Water Intake by Outdoor Temperature Among Children Aged 1-10 Years: Implications for Community Water Fluoridation in the U.S.

    Science.gov (United States)

    Beltrán-Aguilar, Eugenio D; Barker, Laurie; Sohn, Woosung; Wei, Liang

    2015-01-01

    The U.S. water fluoridation recommendations, which have been in place since 1962, were based in part on findings from the 1950s that children's water intake increased with outdoor temperature. We examined whether or not water intake is associated with outdoor temperature. Using linked data from the National Health and Nutrition Examination Survey (NHANES) 1999-2004 and the National Oceanic and Atmospheric Administration, we examined reported 24-hour total and plain water intake in milliliters per kilogram of body weight per day of children aged 1-10 years by maximum outdoor temperature on the day of reported water intake, unadjusted and adjusted for age, sex, race/ethnicity, and poverty status. We applied linear regression methods that were used in previously reported analyses of data from NHANES 1988-1994 and from the 1950s. We found that total water intake was not associated with temperature. Plain water intake was weakly associated with temperature in unadjusted (coefficient 5 0.2, p=0.015) and adjusted (coefficient 5 0.2, p=0.013) linear regression models. However, these models explained little of the individual variation in plain water intake (unadjusted: R(2)=0.005; adjusted: R(2)=0.023). Optimal fluoride concentration in drinking water to prevent caries need not be based on outdoor temperature, given the lack of association between total water intake and outdoor temperature, the weak association between plain water intake and outdoor temperature, and the minimal amount of individual variance in plain water intake explained by outdoor temperature. These findings support the change in the U.S. Public Health Service recommendation for fluoride concentration in drinking water for the prevention of dental caries from temperature-related concentrations to a single concentration that is not related to outdoor temperature.

  1. Water Intake by Outdoor Temperature Among Children Aged 1–10 Years: Implications for Community Water Fluoridation in the U.S.

    Science.gov (United States)

    Beltrán-Aguilar, Eugenio D.; Sohn, Woosung; Wei, Liang

    2015-01-01

    Objective The U.S. water fluoridation recommendations, which have been in place since 1962, were based in part on findings from the 1950s that children's water intake increased with outdoor temperature. We examined whether or not water intake is associated with outdoor temperature. Methods Using linked data from the National Health and Nutrition Examination Survey (NHANES) 1999–2004 and the National Oceanic and Atmospheric Administration, we examined reported 24-hour total and plain water intake in milliliters per kilogram of body weight per day of children aged 1–10 years by maximum outdoor temperature on the day of reported water intake, unadjusted and adjusted for age, sex, race/ethnicity, and poverty status. We applied linear regression methods that were used in previously reported analyses of data from NHANES 1988–1994 and from the 1950s. Results We found that total water intake was not associated with temperature. Plain water intake was weakly associated with temperature in unadjusted (coefficient 5 0.2, p=0.015) and adjusted (coefficient 5 0.2, p=0.013) linear regression models. However, these models explained little of the individual variation in plain water intake (unadjusted: R2=0.005; adjusted: R2=0.023). Conclusion Optimal fluoride concentration in drinking water to prevent caries need not be based on outdoor temperature, given the lack of association between total water intake and outdoor temperature, the weak association between plain water intake and outdoor temperature, and the minimal amount of individual variance in plain water intake explained by outdoor temperature. These findings support the change in the U.S. Public Health Service recommendation for fluoride concentration in drinking water for the prevention of dental caries from temperature-related concentrations to a single concentration that is not related to outdoor temperature. PMID:26346578

  2. Proteomic analysis of zebrafish embryos exposed to simulated-microgravity

    Science.gov (United States)

    Hang, Xiaoming; Ma, Wenwen; Wang, Wei; Liu, Cong; Sun, Yeqing

    Microgravity can induce a serial of physiological and pathological changes in human body, such as cardiovascular functional disorder, bone loss, muscular atrophy and impaired immune system function, etc. In this research, we focus on the influence of microgravity to vertebrate embryo development. As a powerful model for studying vertebrate development, zebrafish embryos at 8 hpf (hour past fertilization) and 24 hpf were placed into a NASA developed bioreac-tor (RCCS) to simulate microgravity for 64 and 48 hours, respectively. The same number of control embryos from the same parents were placed in a tissue culture dish at the same temper-ature of 28° C. Each experiment was repeated 3 times and analyzed by two-dimensional (2-D) gel electrophoresis. Image analysis of silver stained 2-D gels revealed that 64 from total 292 protein spots showed quantitative and qualitative variations that were significantly (P<0.05) and reproducibly different between simulate-microgravity treatment and the stationary control samples. 4 protein spots with significant expression alteration (P<0.01) were excised from 2-D gels and analyzed by MALDI-TOF/TOF mass spectra primarily. Of these proteins, 3 down-regulated proteins were identified as bectin 2, centrosomal protein of 135kDa and tropomyosin 4, while the up-regulated protein was identified as creatine kinase muscle B. Other protein spots showed significant expression alteration will be identified successively and the corresponding genes expression will also be measured by Q-PCR method at different development stages. The data presented in this study illustrate that zebrafish embryo can be significantly induced by microgravity on the expression of proteins involved in bone and muscle formation. Key Words: Danio rerio; Simulated-microgravity; Proteomics

  3. Lineage specification in the early mouse embryo.

    Science.gov (United States)

    Lanner, Fredrik

    2014-02-01

    Before the mammalian embryo is ready to implant in the uterine wall, the single cell zygote must divide and differentiate into three distinct tissues; trophectoderm (prospective placenta), primitive endoderm (prospective yolk sac), and pluripotent epiblast cells which will form the embryo proper. In this review I will discuss our current understanding of how positional information, cell polarization, signaling pathways, and transcription factor networks converge to drive and regulate the progressive segregation of the first three cell types in the mouse embryo. © 2013 Published by Elsevier Inc.

  4. Successful pregnancy rates achieved with day 4 embryo transfers.

    Science.gov (United States)

    Skorupski, Josh C; Stein, Daniel E; Acholonu, Uchenna; Field, Heather; Keltz, Martin

    2007-04-01

    To assess the success of day 4 embryo transfers (ETs) following IVF at one institution. Retrospective analysis. A university hospital IVF program. Two hundred nondonor, fresh IVF cycles. None. Outcomes of IVF. Outcome assessments after day 4 ETs included rates of implantation, clinical pregnancy, and singleton and multiple live births. The overall live-birth rate was 54.4%. Implantation rates were highest in younger age groups, and similar in patients 35-40 years of age. Pregnancy and live-birth rates were similar across all age groups up to age 40 years. Multiple gestations were highest in women < or =40 years of age. Acceptable pregnancy rates can be achieved with day 4 ETs.

  5. Cleavage events and sperm dynamics in chick intrauterine embryos.

    Directory of Open Access Journals (Sweden)

    Hyung Chul Lee

    Full Text Available This study was undertaken to elucidate detailed event of early embryogenesis in chicken embryos using a noninvasive egg retrieval technique before oviposition. White Leghorn intrauterine eggs were retrieved from 95 cyclic hens aged up to 54-56 weeks and morphogenetic observation was made under both bright field and fluorescent image in a time course manner. Differing from mammals, asymmetric cleavage to yield preblastodermal cells was observed throughout early embryogenesis. The first two divisions occurred synchronously and four polarized preblastodermal cells resulted after cruciform cleavage. Then, asynchronous cleavage continued in a radial manner and overall cell size in the initial cleavage region was smaller than that in the distal area. Numerous sperms were visible, regardless of zygotic nuclei formation. Condensed sperm heads were present mainly in the perivitelline space and cytoplasm, and rarely in the yolk region, while decondensed sperm heads were only visible in the yolk. In conclusion, apparent differences in sperm dynamics and early cleavage events compared with mammalian embryos were detected in chick embryo development, which demonstrated polarized cleavage with penetrating supernumerary sperm into multiple regions.

  6. (U-Th)/He ages of phosphates from Zagami and ALHA77005 Martian meteorites: Implications to shock temperatures

    Science.gov (United States)

    Min, Kyoungwon; Farah, Annette E.; Lee, Seung Ryeol; Lee, Jong Ik

    2017-01-01

    Shock conditions of Martian meteorites provide crucial information about ejection dynamics and original features of the Martian rocks. To better constrain equilibrium shock temperatures (Tequi-shock) of Martian meteorites, we investigated (U-Th)/He systematics of moderately-shocked (Zagami) and intensively shocked (ALHA77005) Martian meteorites. Multiple phosphate aggregates from Zagami and ALHA77005 yielded overall (U-Th)/He ages 92.2 ± 4.4 Ma (2σ) and 8.4 ± 1.2 Ma, respectively. These ages correspond to fractional losses of 0.49 ± 0.03 (Zagami) and 0.97 ± 0.01 (ALHA77005), assuming that the ejection-related shock event at ∼3 Ma is solely responsible for diffusive helium loss since crystallization. For He diffusion modeling, the diffusion domain radius is estimated based on detailed examination of fracture patterns in phosphates using a scanning electron microscope. For Zagami, the diffusion domain radius is estimated to be ∼2-9 μm, which is generally consistent with calculations from isothermal heating experiments (1-4 μm). For ALHA77005, the diffusion domain radius of ∼4-20 μm is estimated. Using the newly constrained (U-Th)/He data, diffusion domain radii, and other previously estimated parameters, the conductive cooling models yield Tequi-shock estimates of 360-410 °C and 460-560 °C for Zagami and ALHA77005, respectively. According to the sensitivity test, the estimated Tequi-shock values are relatively robust to input parameters. The Tequi-shock estimates for Zagami are more robust than those for ALHA77005, primarily because Zagami yielded intermediate fHe value (0.49) compared to ALHA77005 (0.97). For less intensively shocked Zagami, the He diffusion-based Tequi-shock estimates (this study) are significantly higher than expected from previously reported Tpost-shock values. For intensively shocked ALHA77005, the two independent approaches yielded generally consistent results. Using two other examples of previously studied Martian meteorites

  7. ( Zea mays l .) from mature zygotic embryo through callus initiation

    African Journals Online (AJOL)

    The use of immature zygotic embryos as an explant for maize regeneration has been hampered by the strictly limited suitable duration of immature embryos for culture. In contrast, mature zygotic embryos harvested from dry seeds are ubiquitous. However, generally mature embryos and especially tropical maize genotypes ...

  8. Ultrastructural changes in goat interspecies and intraspecies reconstructed early embryos

    DEFF Research Database (Denmark)

    Tao, Yong; Gheng, Lizi; Zhang, Meiling

    2008-01-01

    development. The zona pellucida (ZP) in all three types of embryos became thinner and ZP pores in both GC and GG embryos showed an increased rate of development, especially for GC embryos, while in vivo-produced embryos had smooth ZP. The Golgi apparatus (Gi) and rough endoplasmic reticulum (RER) of the two...

  9. Insights into the Morphological Instability of Bulk Heterojunction PTB7-Th/PCBM Solar Cells upon High-Temperature Aging

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Yen-Ju; Huang, Yu-Ching; Liu, Wei-Shin; Su, Yu-An; Tsao, Cheng-Si; Rwei, Syang-Peng; Wang, Leeyih

    2017-04-18

    The impact of the morphological stability of the donor/acceptor mixture under thermal stress on the photovoltaic properties of bulk heterojunction (BHJ) solar cells based on the poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']-di-thiophene-2,6-diyl-alt-(4-(2 ethylhexyl)-3-fluorothieno[3,4-b]-thiophene)-2-carboxylate-2,6-diyl]/phenyl-C61-butyric acid methylester (PTB7-Th/PC61BM) blend is extensively investigated. Both optical microscopy and transmission electron microscopy micrographs show that long-term high-temperature aging stimulates the formation of microscale clusters, the size of which, however, is about 1 order of magnitude smaller than those observed in thermally annealed poly(3hexylthiophene)/PC61BM composite film. The multilength-scale evolution of the morphology of PTB7-Th/PC61BM film from the scattering profiles of grazing incidence small-angle and wide-angle X-ray scattering indicates the PC61BM molecules spatially confine the self-organization of polymer chains into large domains during cast drying and upon thermal activation. Moreover, some PC61BM molecules accumulate into ~30-40 nm clusters, the number of which increases with heating time. Therefore, the hole mobility in the active layer decays much more rapidly than the electron mobility, leading to unbalanced charge transport and degraded cell performance. Importantly, the three-component blend that is formed by replacing a small amount of PC61BM in the active layer with the bis-adduct of PC61BM (bis-P61M) exhibits robust morphology against thermal stress. Accordingly, the PTB7-Th/PC61BM:bis-PC61BM (8 wt %) device has an extremely stable power conversion efficiency.

  10. Insights into the Morphological Instability of Bulk Heterojunction PTB7-Th/PCBM Solar Cells upon High-Temperature Aging.

    Science.gov (United States)

    Hsieh, Yen-Ju; Huang, Yu-Ching; Liu, Wei-Shin; Su, Yu-An; Tsao, Cheng-Si; Rwei, Syang-Peng; Wang, Leeyih

    2017-05-03

    The impact of the morphological stability of the donor/acceptor mixture under thermal stress on the photovoltaic properties of bulk heterojunction (BHJ) solar cells based on the poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']-dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]-thiophene)-2-carboxylate-2,6-diyl]/phenyl-C61-butyric acid methyl ester (PTB7-Th/PC61BM) blend is extensively investigated. Both optical microscopy and transmission electron microscopy micrographs show that long-term high-temperature aging stimulates the formation of microscale clusters, the size of which, however, is about 1 order of magnitude smaller than those observed in thermally annealed poly(3-hexylthiophene)/PC61BM composite film. The multilength-scale evolution of the morphology of PTB7-Th/PC61BM film from the scattering profiles of grazing incidence small-angle and wide-angle X-ray scattering indicates the PC61BM molecules spatially confine the self-organization of polymer chains into large domains during cast drying and upon thermal activation. Moreover, some PC61BM molecules accumulate into ∼30-40 nm clusters, the number of which increases with heating time. Therefore, the hole mobility in the active layer decays much more rapidly than the electron mobility, leading to unbalanced charge transport and degraded cell performance. Importantly, the three-component blend that is formed by replacing a small amount of PC61BM in the active layer with the bis-adduct of PC61BM (bis-PC61BM) exhibits robust morphology against thermal stress. Accordingly, the PTB7-Th/PC61BM:bis-PC61BM (8 wt %) device has an extremely stable power conversion efficiency.

  11. Serum free embryo culture medium improves in vitro survival of bovine blastocysts to vitrification.

    Science.gov (United States)

    Gómez, E; Rodríguez, A; Muñoz, M; Caamaño, J N; Hidalgo, C O; Morán, E; Facal, N; Díez, C

    2008-05-01

    The aim of this study was to examine the effects of co-culture with Vero cells during the in vitro maturation (IVM) and three culture media, B2+5% fetal calf serum (FCS) on Vero cells, synthetic oviduct fluid (SOF)+5% FCS, and SOF+20 gL(-1) bovine serum albumin (BSA), on the developmental competence of the embryos and their ability to survive vitrification/warming. We also tested the effect of morphological quality and the age of the embryo on its sensitivity to vitrification. The IVM system neither affects the embryo development up to Day 7 nor survival rates after vitrification. The culture of embryos in SOF+FCS and in Vero cells+B2 allowed obtaining more Day 6 and Day 7 blastocysts, and a higher % of Day 7 blastocysts vitrified than culture in SOF+BSA. Contrarily, on Day 8, more blastocysts were vitrified in SOF+BSA than in SOF+FCS. Blastocysts quality affected development after vitrification/warming, and Day 7 embryos showed higher survival rates than their Day 8 counterparts. Day 7 blastocysts produced in Vero cells or in SOF+BSA survived at higher rates than those produced in SOF+FCS at 24 and 48 h after warming. Embryo culture with BSA allows obtaining hatching rates after vitrification/warming higher than those obtained after co-culture with Vero cells in B2 and FCS. Moreover, this system provides hatching rates from Day 8 blastocysts comparable to those obtained on Day 7 in Vero cells. Further studies, including embryo transfer to recipients, are needed to clarify factors affecting the freezability of in vitro produced bovine embryos.

  12. Timing embryo biopsy for PGD - before or after cryopreservation?

    Science.gov (United States)

    Shinar, S; Kornecki, N; Schwartz, T; Mey-Raz, N; Amir, H; Almog, B; Shavit, T; Hasson, J

    2016-09-01

    Pre-implantation genetic diagnosis (PGD) is required in order to screen and diagnose embryos of patients at risk of having a genetically affected offspring. A biopsy to diagnose the genetic profile of the embryo may be performed either before or after cryopreservation. The aim of this study was to determine which biopsy timing yields higher embryo survival rates. Retrospective cohort study of all PGD patients in a public IVF unit between 2010 and 2013. Inclusion criteria were patients with good-quality embryos available for cryopreservation by the slow freezing method. Embryos were divided into two groups: biopsy before and biopsy after cryopreservation. The primary outcome was embryo survival rates post thawing. Sixty-five patients met inclusion criteria. 145 embryos were biopsied before cryopreservation and 228 embryos were cryopreserved and biopsied after thawing. Embryo survival was significantly greater in the latter group (77% vs. 68%, p Cryopreservation preceding biopsy results in better embryo survival compared to biopsy before cryopreservation.

  13. Advanced optical imaging in living embryos

    OpenAIRE

    Canaria, Christie A.; Lansford, Rusty

    2010-01-01

    Developmental biology investigations have evolved from static studies of embryo anatomy and into dynamic studies of the genetic and cellular mechanisms responsible for shaping the embryo anatomy. With the advancement of fluorescent protein fusions, the ability to visualize and comprehend how thousands to millions of cells interact with one another to form tissues and organs in three dimensions (xyz) over time (t) is just beginning to be realized and exploited. In this review, we explore recen...

  14. Embryo disposition and the new death scene

    Directory of Open Access Journals (Sweden)

    Ellison, David

    2011-01-01

    Full Text Available In the IVF clinic - a place designed principally for the production and implantation of embryos - scientists and IVF recipients are faced with decisions regarding the disposition of frozen embryos. At this time there are hundred of thousands of cryopreserved embryos awaiting such determinations. They may be thawed for transfer to the woman herself, they may be donated for research or for use by other infertile couples, they may remain in frozen storage, or they may variously be discarded by being allowed to 'succumb', or 'perish'. Where the choice is discard, some IVF clients have chosen to formalise the process through ceremony. A new language is emerging in response to the desires of the would-be-parents who might wish to characterise the discard experience as a ‘good death’. This article examines the procedure known as ‘compassionate transfer’ where the embryo to be discarded is placed in the woman’s vagina where it is clear that it will not develop further. An alternate method has the embryo transferred in the usual manner but without the benefit of fertility-enhancing hormones at a point in the cycle unreceptive to implantation. The embryo destined for disposal is thus removed from the realm of technological possibility and ‘returned’ to the female body for a homely death. While debates continue about whether or not embryos constitute life, new practices are developing in response to the emotional experience of embryo discard. We argue that compassionate transfer is a death scene taking shape. In this article, we take the measure of this new death scene’s fabrication, and consider the form, significance, and legal complexity of its ceremonies.

  15. Aging of secondary organic aerosol generated from the ozonolysis of α-pinene: effects of ozone, light and temperature

    National Research Council Canada - National Science Library

    Denjean, C; Formenti, P; Picquet-Varrault, B; Camredon, M; Pangui, E; Zapf, P; Katrib, Y; Giorio, C; Tapparo, A; Temime-Roussel, B; Monod, A; Aumont, B; Doussin, J. F

    2015-01-01

    ...) during different forcings. The present experiments represent a first attempt to comprehensively investigate the influence of oxidative processing , photochemistry, and diurnal temperature cycling upon SOA properties...

  16. The effect of biopsy during precompacted morula stage on post vitrification development of blastocyst derived bovine embryos.

    Science.gov (United States)

    Shirazi, Abolfazl; Borjian, Sara; Ahmadi, Ebrahim; Nazari, Hassan; Heidari, Banafsheh

    2010-04-01

    Improvements on embryo micromanipulation techniques led to the use of embryo biopsy in commercial embryo transfer programs for genetic analysis of preimplantation bovine embryos. The aim of this study was to evaluate the quality of bovine blastocyst derived from embryos biopsied at different pre-compacted morulae stages by assessment of cryosurvivability of the resulting blastocysts. The in vitro produced bovine embryos were subjected to biopsy at days 2, 3, and 4 post-insemination with different cell numbers (4 to 16-cells). Embryo cell biopsy was carried out in a 100 µl drop of H-SOF following pronase drilling by aspiration of one blastomere. The biopsied embryos were then cultured in SOFaaBSA co-cultured with oviduct cells-monolayer until blastocyst formation. The blastocysts were cryopreserved at room temperature after exposure of equilibration (glycerol 1.4 M for 5 min and then glycerol 1.4 M and ethylene glycol 3.6 M for 5 min) and vitrification solutions (3.4 M glycerol and 4.6 M ethylene glycol). The blastocysts were loaded into the center of 0.25 ml straws separated by air bubbles from 2 columns of sucrose 0.5 M and plunged immediately into liquid nitrogen. There was no significant difference in cryosurvivability of vitrified-warmed blastocysts derived form biopsied embryos at different pre-compacted morula stages. The quality of biopsy derived blastocysts was identical to that of non-biopsy derived ones in terms of post vitrifcation survival and hatching rates. In conclusion there was no preference between different times of embryo biopsy at precompacted morula stages in term of cryosurvivability of biopsy derived bovine blastocysts.

  17. Effects of aging temperature and time on the corrosion protection provided by trivalent chromium process coatings on AA2024-T3.

    Science.gov (United States)

    Li, Liangliang; Swain, Greg M

    2013-08-28

    The effects of aging temperature and time on the physical structure of and corrosion protection provided by trivalent chromium process (TCP) coatings on AA2024-T3 are reported. The TCP coating forms a partially blocking barrier layer on the alloy surface that consists of hydrated channels and or defects. It is through these channels and defects that ions and dissolved O2 can be transported to small areas of the underlying alloy. Reactions initiate at these sites, which can ultimately lead to undercutting of the coating and localized corrosion. We tested the hypothesis that collapsing the channels and or reducing the number of defects in the coating might be possible through post-deposition heat treatment, and that this would enhance the corrosion protection provided by the coating. This was tested by aging the TCP-coated AA2024 alloys in air overnight at room temperature (RT), 55, 100, or 150 °C. The TCP coating became dehydrated and thinner at the high temperatures (55 and 100 °C). This improved the corrosion protection as evidenced by a 2× increase in the charge transfer resistance. Aging at 150 °C caused excessive coating dehydration and shrinkage. This led to severe cracking and detachment of the coating from the surface. The TCP-coated AA2024 samples were also aged in air at RT from 1 to 7 days. There was no thinning of the coating, but the corrosion protection was enhanced with a longer aging period as evidenced by a 4× increase in the charge transfer resistance. The coating became more hydrophobic after aging at elevated temperature (up to 100 °C) and with aging time at RT as evidenced by an increased water contact angle from 7 to 100 °C.

  18. Foam nests provide context-dependent thermal insulation to embryos of three leptodactylid frogs.

    Science.gov (United States)

    Méndez-Narváez, J; Flechas, S V; Amézquita, A

    2015-01-01

    The choice of adequate breeding habitat and its associated thermoregulatory conditions are thought to be important in the evolution of amphibian reproductive strategies. Among leptodactylid frogs, there is a terrestrial cline in the oviposition sites chosen to build foam nests for eggs. Although several functions have been attributed to foam nests, their role in temperature regulation for embryos is unclear. Here we tested the hypothesis that foam nests buffer embryos from variation in air temperature. We examined the degree of terrestrial nest sites in three species, finding a terrestrial cline of sites in terms of distance from water. We tested whether this nest-insulation effect varied among these species that differ in the degree of terrestrial nest sites and whether translocating nests impacted embryonic mortality. Our results demonstrate a negative effect of translocating aquatic nests to land, inferred from the highest hatching success in natural nests sites. All nests attenuated environmental thermal variation, but more terrestrial nests buffered embryos from a greater range of temperatures than did aquatic ones. Altogether, our data indicate that foam nests insulate embryos from daily temperature fluctuations among leptodactylid frogs with different degrees of terrestrial nests, which may well have contributed to the evolution of this reproductive strategy.

  19. Effect of thermal aging on grain structural characteristic and Ductile-to-Brittle transition temperature of CLAM steel at 550 °C

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); University of Science and Technology of China, Hefei, Anhui, 230031 (China); Chen, Jianwei [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); Xu, Gang, E-mail: gang.xu@fds.org.cn [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China)

    2017-02-15

    Highlights: • The grain boundary length per unit area decreased with the increasing aging time. • The fraction of LABs increased obviously after thermal aging. • Prior austenitic grain refinement is more important to improve low temperature toughness. - Abstract: In this work, electron backscatter diffraction (EBSD) was used to investigate the grain structure evolution of China low activation martensitic (CLAM) steel samples which were aged at 550 °C for 0 h, 2000 h, 4000 h and 10,000 h. The results showed that the prior austenitic grain size increased with the aging time, which led to the decrease of grain boundary length. The fraction of misorientation angle in a range from about 4 to 10° increased obviously after thermal aging for 10,000 h, and it indicated that the fine subgrains formed in the CLAM steel during the long-term thermal exposure. Furthermore, Charpy impact experiments were carried out to analyze the toughness of the CLAM steel before and after aging, particularly the Ductile-to-Brittle Transition Temperature (DBTT). Though amounts of fine subgrians formed in matrix, a substantial increase in DBTT (∼40.1 °C) had been noticed after aging for 10,000 h. The results showed that the high angle boundaries such as prior austenitic grain boundaries are more effective in retarding the propagation of cleavage crack than subgrain boundaries.

  20. Miniaturized embryo array for automated trapping, immobilization and microperfusion of zebrafish embryos.

    Directory of Open Access Journals (Sweden)

    Jin Akagi

    Full Text Available Zebrafish (Danio rerio has recently emerged as a powerful experimental model in drug discovery and environmental toxicology. Drug discovery screens performed on zebrafish embryos mirror with a high level of accuracy the tests usually performed on mammalian animal models, and fish embryo toxicity assay (FET is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, automated in-situ analysis of zebrafish embryos is still deeply in its infancy. This is mostly due to the inherent limitations of conventional techniques and the fact that metazoan organisms are not easily susceptible to laboratory automation. In this work, we describe the development of an innovative miniaturized chip-based device for the in-situ analysis of zebrafish embryos. We present evidence that automatic, hydrodynamic positioning, trapping and long-term immobilization of single embryos inside the microfluidic chips can be combined with time-lapse imaging to provide real-time developmental analysis. Our platform, fabricated using biocompatible polymer molding technology, enables rapid trapping of embryos in low shear stress zones, uniform drug microperfusion and high-resolution imaging without the need of manual embryo handling at various developmental stages. The device provides a highly controllable fluidic microenvironment and post-analysis eleuthero-embryo stage recovery. Throughout the incubation, the position of individual embryos is registered. Importantly, we also for first time show that microfluidic embryo array technology can be effectively used for the analysis of anti-angiogenic compounds using transgenic zebrafish line (fli1a:EGFP. The work provides a new rationale for rapid and automated manipulation and analysis of developing zebrafish embryos at a large scale.

  1. Temperature manipulation during layer chick embryogenesis

    NARCIS (Netherlands)

    Walstra, I.; Napel, ten J.; Kemp, B.; Brand, van den H.

    2010-01-01

    The current study investigated the effects of temperature manipulation (TM) during late embryogenesis on temperature preference, response to high environmental temperature, behavior, and performance in young layer chicks. Control (CC) embryos (n = 96) were incubated at 37.8°C eggshell temperature

  2. [Effect of early pregnancy electromagnetic field exposure on embryo growth ceasing].

    Science.gov (United States)

    Han, Jingxiu; Cao, Zhaojin; Liu, Xinyan; Zhang, Wenli; Zhang, Shuzhen

    2010-05-01

    To study the effect of electromagnetic exposure during the first three months of pregnancy on embryo growth ceasing. The cases were defined as embryo growth ceasing, exclude the cases caused by maternal chromosomal abnormalities, maternal and child exclusion and genital malformations. The controls were selected in the termly delivery puerperas with normal newborn in the same hospital and matched by age (+/- 2 years). The analysis was conduct based on the interview of 138 embryo growth ceasing cases and the matched control (age +/- 2 years) by using multifactor conditional Logistic regression analysis. The proportion of watching TV, using mobile telephone, using copycat > or =6 minutes/week or microwave oven, electromagnetic equipment near the dwell or work place, e.g., high voltage line safety protection when using the appliances, e.g., distance protection.

  3. In vitro and in vivo Development of Cloned Ovine Embryos using in vitro and in vivo Matured Oocytes

    DEFF Research Database (Denmark)

    Holm, P; Nagashima, H; Sun, F-J

    1995-01-01

    Cloning of sheep embryos by nucleus transplantation can be achieved by using in vivo matured (oviductal) oocytes and in vivo culture. However, these steps involve cumbersome procedures. Therefore, the effects of in vivo vs. the equivalent in vitro procedures on the pre-implantation development...... matured oocytes were enucleated and fused with inserted blastomeres from donor embryos. In vitro matured oocytes were enucleated and allowed to age prior to blastomere insertion and electrofusion. Fused embryos were cultured for approximately 132 h either in vivo in ligated sheep oviducts or in vitro...

  4. Complexity of the relationships between the sintering-temperature-dependent grain size, airborne-particle abrasion, ageing and strength of 3Y-TZP ceramics.

    Science.gov (United States)

    Cotič, Jasna; Jevnikar, Peter; Kocjan, Andraž; Kosmač, Tomaž

    2016-04-01

    This study was designed to explore the complex relationships between the sintering-temperature-dependent grain size, airborne-particle abrasion, ageing and strength of 3Y-TZP ceramics. Biomedical grade 3Y-TZP powder was used to fabricate 180 discs. Half of them were sintered at 1400°C for 2h and half at 1500°C for 2h. A total of 18 groups of 10 were formed and subjected to the fully crossed experimental protocol of airborne-particle abrasion with Al2O3 at 2.5bar (no abrasion, 50μm, 110μm) and accelerated ageing at 134°C (no ageing, 12h, 48h). The relative amount of monoclinic phase was determined with XRD. The biaxial flexural strength was measured and statistically analyzed using the three-way ANOVA followed by predetermined contrasts and Tukey's HSD test (α=0.05). The low-temperature-sintered, fine-grained ceramic exhibited an excellent ageing resistance, while the high-temperature-sintered, coarse-grained ceramic experienced a higher surface strengthening and a substantially improved ageing resistance with respect to the airborne-particle abrasion. The overall performance of this material was superior. Our results show that the sintering temperature has a minor effect on the flexural strength, but it plays a crucial role in the surface strengthening and the ageing behaviour of 3Y-TZP dental ceramics. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Increasing The Number of Embryos Transferred from Two to Three, Does not Increase Pregnancy Rates in Good Prognosis Patients

    Directory of Open Access Journals (Sweden)

    Mahnaz Ashrafi

    2015-10-01

    Full Text Available Background: To compare the pregnancy outcomes after two embryos versus three embryos transfers (ETs in women undergoing in vitro fertilization (IVF/intracytoplasmic sperm injection (ICSI cycles. Materials and Methods: This retrospective study was performed on three hundred eighty seven women with primary infertility and with at least one fresh embryo in good quality in order to transfer at each IVF/ICSI cycle, from September 2006 to June 2010. Patients were categorized into two groups according to the number of ET as follows: ET2 and ET3 groups, indicating two and three embryos were respectively transferred. Pregnancy outcomes were compared between ET2 and ET3 groups. Chi square and student t tests were used for data analysis. Results: Clinical pregnancy and live birth rates were similar between two groups. The rates of multiple pregnancies were 27 and 45.2% in ET2 and ET3 groups, respectively. The rate of multiple pregnancies in young women was significantly increased when triple instead of double embryos were transferred. Logistic regression analysis indicated two significant prognostic variables for live birth that included number and quality of transferred embryos; it means that the chance of live birth following ICSI treatment increased 3.2-fold when the embryo with top quality (grade A was transferred, but the number of ET had an inverse relationship with live birth rate; it means that probability of live birth in women with transfer of two embryos was three times greater than those who had three ET. Conclusion: Due to the difficulty of implementation of the elective single-ET technique in some infertility centers in the world, we suggest transfer of double instead of triple embryos when at least one good quality embryo is available for transfer in women aged 39 years or younger. However, to reduce the rate of multiple pregnancies, it is recommended to consider the elective single ET strategy.

  6. Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Chen, Zhiqiang; Guirguis, Cherif; Akinade, Kola

    2017-10-01

    The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases with higher electric power condition, which brings the component into an elevated temperature environment, thus introducing another consideration factor for mechanical stability of interconnection joints. Since most of the shock performance data available were produced at room temperature, the effect of elevated temperature is of interest to ensure the reliability of the device in a mechanical shock environment. To achieve a stable␣interconnect in a dynamic shock environment, the interconnections must tolerate mechanical strain, which is induced by the shock wave input and reaches the particular component interconnect joint. In this study, large body size (52.5 × 52.5 mm2) FCBGA components assembled on 2.4-mm-thick boards were tested with various isothermal pre-conditions and testing conditions. With a heating element embedded in the test board, a test temperature range from room temperature to 100°C was established. The effects of elevated temperature on mechanical shock performance were investigated. Failure and degradation mechanisms are identified and discussed based on the microstructure evolution and grain structure transformations.

  7. Meanings of the embryo in Japan: narratives of IVF experience and embryo ownership

    NARCIS (Netherlands)

    Kato, M.; Sleeboom-Faulkner, M.

    2011-01-01

    This article explores the sociocultural meanings of the embryo implied in the narratives of 58 women who have undergone in vitro fertilisation in Japan over a period from 2006 to 2008. We argue that a lack of sufficient analysis of the sociocultural meanings of the embryo result in a situation where

  8. Is preimplantation genetic diagnosis the ideal embryo selection method in aneuploidy screening?

    Science.gov (United States)

    Sahin, Levent; Bozkurt, Murat; Sahin, Hilal; Gürel, Aykut; Yumru, Ayse Ender

    2014-10-01

    To select cytogenetically normal embryos, preimplantation genetic diagnosis (PGD) aneuploidy screening (AS) is used in numerous centers around the world. Chromosomal abnormalities lead to developmental problems, implantation failure, and early abortion of embryos. The usefulness of PGD in identifying single-gene diseases, human leukocyte antigen typing, X-linked diseases, and specific genetic diseases is well-known. In this review, preimplantation embryo genetics, PGD research studies, and the European Society of Human Reproduction and Embryology PGD Consortium studies and reports are examined. In addition, criteria for embryo selection, technical aspects of PGD-AS, and potential noninvasive embryo selection methods are described. Indications for PGD and possible causes of discordant PGD results between the centers are discussed. The limitations of fluorescence in situ hybridization, and the advantages of the array comparative genomic hybridization are included in this review. Although PGD-AS for patients of advanced maternal age has been shown to improve in vitro fertilization outcomes in some studies, to our knowledge, there is not sufficient evidence to use advanced maternal age as the sole indication for PGD-AS. PGD-AS might be harmful and may not increase the success rates of in vitro fertilization. At the same time PGD, is not recommended for recurrent implantation failure and unexplained recurrent pregnancy loss. Copyright © 2014. Published by Elsevier Taiwan.

  9. Is preimplantation genetic diagnosis the ideal embryo selection method in aneuploidy screening?

    Directory of Open Access Journals (Sweden)

    Levent Sahin

    2014-10-01

    Full Text Available To select cytogenetically normal embryos, preimplantation genetic diagnosis (PGD aneuploidy screening (AS is used in numerous centers around the world. Chromosomal abnormalities lead to developmental problems, implantation failure, and early abortion of embryos. The usefulness of PGD in identifying single-gene diseases, human leukocyte antigen typing, X-linked diseases, and specific genetic diseases is well-known. In this review, preimplantation embryo genetics, PGD research studies, and the European Society of Human Reproduction and Embryology PGD Consortium studies and reports are examined. In addition, criteria for embryo selection, technical aspects of PGD-AS, and potential noninvasive embryo selection methods are described. Indications for PGD and possible causes of discordant PGD results between the centers are discussed. The limitations of fluorescence in situ hybridization, and the advantages of the array comparative genomic hybridization are included in this review. Although PGD-AS for patients of advanced maternal age has been shown to improve in vitro fertilization outcomes in some studies, to our knowledge, there is not sufficient evidence to use advanced maternal age as the sole indication for PGD-AS. PGD-AS might be harmful and may not increase the success rates of in vitro fertilization. At the same time PGD, is not recommended for recurrent implantation failure and unexplained recurrent pregnancy loss.

  10. Integrated chip-based physiometer for automated fish embryo toxicity biotests in pharmaceutical screening and ecotoxicology.

    Science.gov (United States)

    Akagi, Jin; Zhu, Feng; Hall, Chris J; Crosier, Kathryn E; Crosier, Philip S; Wlodkowic, Donald

    2014-06-01

    Transgenic zebrafish (Danio rerio) models of human diseases have recently emerged as innovative experimental systems in drug discovery and molecular pathology. None of the currently available technologies, however, allow for automated immobilization and treatment of large numbers of spatially encoded transgenic embryos during real-time developmental analysis. This work describes the proof-of-concept design and validation of an integrated 3D microfluidic chip-based system fabricated directly in the poly(methyl methacrylate) transparent thermoplastic using infrared laser micromachining. At its core, the device utilizes an array of 3D micromechanical traps to actively capture and immobilize single embryos using a low-pressure suction. It also features built-in piezoelectric microdiaphragm pumps, embryo-trapping suction manifold, drug delivery manifold, and optically transparent indium tin oxide heating element to provide optimal temperature during embryo development. Furthermore, we present design of the proof-of-concept off-chip electronic interface equipped with robotic servo actuator driven stage, innovative servomotor-actuated pinch valves, and embedded miniaturized fluorescent USB microscope. Our results showed that the innovative device has 100% embryo-trapping efficiency while supporting normal embryo development for up to 72 hr in a confined microfluidic environment. We also showed data that this microfluidic system can be readily applied to kinetic analysis of a panel of investigational antiangiogenic agents in transgenic zebrafish lines. The optical transparency and embryo immobilization allow for convenient visualization of developing vasculature patterns in response to drug treatment without the need for specimen re-positioning. The integrated electronic interfaces bring the lab-on-a-chip systems a step closer to realization of complete analytical automation. © 2014 International Society for Advancement of Cytometry.

  11. Developmental competence of porcine chimeric embryos produced by aggregation

    DEFF Research Database (Denmark)

    Li, Juan; Jakobsen, Jannik E.; Xiong, Qiang

    2015-01-01

    The purpose of our study was to compare the developmental competence and blastomere allocation of porcine chimeric embryos formed by micro-well aggregation. Chimeras were created by aggregating either two blastomeres originating from 2-cell embryos or two whole embryos, where embryos were produced...... either by parthenogenetic activation (PA) or handmade cloning (HMC). Results showed that the developmental competence of chimeric embryos, evaluated based on their blastocyst rate and total cell number per blastocyst, was increased when two whole 2-cell stage embryos (PA or HMC) were aggregated....... In comparison, when two blastomeres were aggregated, the developmental competence of the chimeric embryos decreased if the blastomeres were either from PA or from HMC embryos, but not if they were from different sources, i.e. one PA and one HMC blastomere. To evaluate the cell contribution in embryo formation...

  12. Patients' Attitudes towards the Surplus Frozen Embryos in China

    Directory of Open Access Journals (Sweden)

    Xuan Jin

    2013-01-01

    Full Text Available Background. Assisted reproductive techniques have been used in China for more than 20 years. This study investigates the attitudes of surplus embryo holders towards embryos storage and donation for medical research. Methods. A total of 363 couples who had completed in vitro fertilization (IVF treatment and had already had biological children but who still had frozen embryos in storage were invited to participate. Interviews were conducted by clinics in a narrative style. Results. Family size was the major reason for participants’ (discontinuation of embryo storage; moreover, the moral status of embryos was an important factor for couples choosing embryo storage, while the storage fee was an important factor for couples choosing embryo disposal. Most couples discontinued the storage of their embryos once their children were older than 3 years. In our study, 58.8% of the couples preferred to dispose of surplus embryos rather than donate them to research, citing a lack of information and distrust in science as significant reasons for their decision. Conclusions. Interviews regarding frozen embryos, including patients’ expectations for embryo storage and information to assist them with decisions regarding embryo disposal, are beneficial for policies addressing embryo disposition and embryo donation in China.

  13. Metabolite profiling of somatic embryos of Cyclamen persicum in comparison to zygotic embryos, endosperm and testa

    Directory of Open Access Journals (Sweden)

    Traud eWinkelmann

    2015-08-01

    Full Text Available Somatic embryogenesis has been shown to be an efficient in vitro plant regeneration system for many crops such as the important ornamental plant Cyclamen persicum, for which this regeneration pathway of somatic embryogenesis is of interest for the vegetative propagation of parental lines as well as elite plants. However, somatic embryogenesis is not commercially used in many crops due to several unsolved problems, such as malformations, asynchronous development, deficiencies in maturation and germination of somatic embryos. In contrast, zygotic embryos in seeds develop and germinate without abnormalities in most cases. Instead of time-consuming and labor-intensive experiments involving tests of different in vitro culture conditions and plant growth regulator supplements, we follow a more directed approach. Zygotic embryos served as a reference and were compared to somatic embryos in metabolomic analyses allowing the future optimization of the in vitro system. The aims of this study were to detect differences in the metabolite profiles of torpedo stage somatic and zygotic embryos of C. persicum. Moreover, major metabolites in endosperm and testa were identified and quantified.Two sets of extracts of two to four biological replicates each were analyzed. In total 52 metabolites were identified and quantified in the different tissues. One of the most significant differences between somatic and zygotic embryos was that the proline concentration in the zygotic embryos was about 40 times higher than that found in somatic embryos. Epicatechin, a scavenger for reactive oxygen species, was found in highest abundance in the testa. Sucrose, the most abundant metabolite was detected in significantly higher concentrations in zygotic embryos. Also, a yet unknown trisaccharide, was significantly enriched in zygotic embryos.

  14. Formation of somatic embryos in Persea americana Mill var Catalina from immature zygotic embryos.

    Directory of Open Access Journals (Sweden)

    Lillien Fajardo Rosabal

    2005-04-01

    Full Text Available The establishment of embryogenic culture of avocado have been achieved in different genotypes, usually the immature zygotic embryos are the initial explants and the process has been described in several variety. In the present paper the induction of the somatic embryogenesis in avocado (Catalina variety from zygotic embryos is proposed. Zygotic embryos taken from unripe fruits were used as explants . The fruits were divided into five groups according to their size. The embryos were cultured in a medium containing 4-amino-3,5,6 trichlorpicolinic acid (Picloram in concentrations of 0.1, 0.4, and 0.6 uM. The culture medium used for the induction of the somatic embryogenesis consisted of: Macro B5, Micro MS, thiamine (0.8 mg.l-1, myo-inositol (100 mg.l-1, sucrose (30g.l-1 and pH 5.7. The number of zygotic embryos with opened cotyledonal leaves was evaluated starting from the third day of culture. It was also evaluated the number of fenolized zygotic embryos at the third week of culture and the presence of somatic embryos five weeks after the culture initiation. The formation of somatic embryos was achieved in all the treatments. The highest number of explants that formed somatic embryos was achieved when a concentration of 0.6 uM of Picloram was used and the second group of size (0.71 x 0.65 mm observing significant differences between the different groups of fruit size. Keywords: avocado, cotyledonal leafs, somatic embryo,

  15. Metabolite profiling of somatic embryos of Cyclamen persicum in comparison to zygotic embryos, endosperm, and testa

    Science.gov (United States)

    Winkelmann, Traud; Ratjens, Svenja; Bartsch, Melanie; Rode, Christina; Niehaus, Karsten; Bednarz, Hanna

    2015-01-01

    Somatic embryogenesis has been shown to be an efficient in vitro plant regeneration system for many crops such as the important ornamental plant Cyclamen persicum, for which this regeneration pathway of somatic embryogenesis is of interest for the vegetative propagation of parental lines as well as elite plants. However, somatic embryogenesis is not commercially used in many crops due to several unsolved problems, such as malformations, asynchronous development, deficiencies in maturation and germination of somatic embryos. In contrast, zygotic embryos in seeds develop and germinate without abnormalities in most cases. Instead of time-consuming and labor-intensive experiments involving tests of different in vitro culture conditions and plant growth regulator supplements, we follow a more directed approach. Zygotic embryos served as a reference and were compared to somatic embryos in metabolomic analyses allowing the future optimization of the in vitro system. The aims of this study were to detect differences in the metabolite profiles of torpedo stage somatic and zygotic embryos of C. persicum. Moreover, major metabolites in endosperm and testa were identified and quantified. Two sets of extracts of two to four biological replicates each were analyzed. In total 52 metabolites were identified and quantified in the different tissues. One of the most significant differences between somatic and zygotic embryos was that the proline concentration in the zygotic embryos was about 40 times higher than that found in somatic embryos. Epicatechin, a scavenger for reactive oxygen species, was found in highest abundance in the testa. Sucrose, the most abundant metabolite was detected in significantly higher concentrations in zygotic embryos. Also, a yet unknown trisaccharide, was significantly enriched in zygotic embryos. PMID:26300898

  16. Impact of needle age on the response of respiration in Scots pine to long-term elevation of carbon dioxide concentration and temperature.

    Science.gov (United States)

    Zha, Tianshan; Wang, Kai-Yun; Ryyppö, Aija; Kellomäki, Seppo

    2002-12-01

    Sixteen 20-year-old Scots pine (Pinus sylvestris L.) trees growing in the field were enclosed in environment-controlled chambers that for 4 years maintained: (1) ambient conditions (CON); (2) elevated atmospheric carbon dioxide concentration [CO2] (ambient + 350 micromol mol-1; EC); (3) elevated temperature (ambient + 2-3 degrees C; ET); or (4) elevated [CO2] and temperature (EC+ET). Dark respiration rate, specific leaf area (SLA) and the concentrations of starch and soluble sugars in needles were measured in the fourth year. Respiration rates, on both an area and a mass basis, and SLA decreased in EC relative to CON, but increased in ET and EC+ET, regardless of needle age class. Starch and soluble sugar concentrations for a given needle age class increased in EC, but decreased slightly in ET and EC+ET. Respiration rates and SLA were highest in current-year needles in all treatments, whereas starch and soluble sugar concentrations were highest in 1-year-old needles. Relative to that of older needles, respiration of current-year needles was inhibited less by EC, but increased in response to ET and EC+ET. All treatments enhanced the difference in respiration between current-year and older needles relative to that in CON. Age had a greater effect on needle respiration than any of the treatments. There were no differences in carbohydrate concentration or SLA between needle age classes in response to any treatment. Relative to CON, the temperature coefficient (Q10) of respiration increased slightly in EC, regardless of age, but declined significantly in ET and EC+ET, indicating acclimation of respiration to temperature.

  17. Biosensors for detecting stress in developing embryos

    Science.gov (United States)

    Purdey, Malcolm S.; Saini, Avishkar; McLennan, Hanna J.; Pullen, Benjamin J.; Schartner, Erik P.; Sutton-McDowall, Melanie L.; Thompson, Jeremy G.; Monro, Tanya M.; Nicholls, Stephen J.; Abell, Andrew D.

    2016-12-01

    Reactive Oxygen Species (ROS) cause DNA damage and defective function in sperm and also affects the developmental competence of embryos. It is therefore critical to monitor ROS in sperm, oocytes and developing embryos. In particular, hydrogen peroxide (H2O2) is a ROS important to normal cell function and signalling as well as its role in oxidative stress. Here we report the development of a fluorescent sensor for H2O2 using carboxyperoxyfluor-1 (CPF1) in solution and attached to a glass slide or multi-mode optical fibre. CPF1 increases in fluorescence upon reaction with H2O2 to non-invasively detect H2O2 near developing embryos. These probes are constructed by immobilising CPF1 to the optical fibre tip a polyacrylamide layer. Also reported is a new dual optical fibre sensor for detecting both H2O2 and pH that is functional at biologically concentrations of H2O2 and can sense pH to 0.1 units. This research shows promise for the use of optical fibre sensors for monitoring the health of developing embryos. Furthermore, these sensors are applicable for use beyond embryos such as detecting stress in endothelial cells involved in cardiovascular dysfunction.

  18. Low-cost silicone imaging casts for zebrafish embryos and larvae.

    Science.gov (United States)

    Masselink, Wouter; Wong, Jin Cheng; Liu, Boyin; Fu, Jing; Currie, Peter David

    2014-02-01

    Due to their size and optical clarity, zebrafish embryos have long been appreciated for their usefulness in time-lapse confocal microscopy. Current methods of mounting zebrafish embryos and larvae for imaging consist mainly of mounting in low percentage, low melting temperature agarose in a Petri dish. Whereas imaging methods have advanced greatly over the last two decades, the methods for mounting embryos have not changed significantly. In this article, we describe the development and use of 3D printed plastic molds. These molds can be used to create silicone casts and allow embryos and larvae to be mounted with a consistent and reproducible angle, and position in X, Y, and Z. These molds are made on a 3D printer and can be easily and cheaply reproduced by anyone with access to a 3D printer, making this method accessible to the entire zebrafish community. Molds can be reused to create additional casts, which can be reused after imaging. These casts are compatible with any upright microscope and can be adapted for use on an inverted microscope, taking the working distance of the objective used into account. This technique should prove to be useful to any researcher imaging zebrafish embryos.

  19. Cryopreservation of bovine in vitro produced embryos using ethylene glycol in controlled freezing or vitrification.

    Science.gov (United States)

    Sommerfeld, V; Niemann, H

    1999-03-01

    In this study, the cryoprotectant ethylene glycol (EG) was tested for its ability to improve and facilitate the cryopreservation of in vitro produced (IVP) bovine embryos. Embryos were cryopreserved in EG solutions supplemented with either newborn calf serum (NBCS) or polyvinyl alcohol (PVA). To assess EG toxicity, the embryos were equilibrated in EG concentrations from 1.8 to 8.9 M at room temperature for 10 min and then cultured for 72 h on a cumulus cell monolayer. The hatching rate was highest for day 7 blastocysts frozen in 3.6 M EG (98%) and was not different from the control group (85%). The controlled freezing (0.3 degrees C/min to -35 degrees C) of expanded day 7 blastocysts resulted in a hatching rate of 81%, which was similar to that of the nonfrozen controls (76%). Differential staining revealed only very few degenerate blastomeres attributed to freezing and thawing. Upon direct nonsurgical transfer of day 7 expanded blastocysts frozen in 3.6 M EG, a pregnancy rate of 43% was achieved, while the pregnancy rate after transfer of other developmental stages was significantly lower (22% with expanded day 8 blastocysts). When bovine IVP embryos were incubated at room temperature in 7.2 M EG preceded by preequilibration in 3.6 M EG, the hatching rate of day 7 expanded blastocysts reached 93%. Upon vitrification of IVP day 7 and day 8 blastocysts and expanded blastocysts in 7.2 M EG, the latter showed a higher hatching rate (42%) than blastocysts (12%). Overall, PVA as supplement to the basic freezing solution instead of NBCS had deleterious effects on survival after controlled freezing or vitrification. The simple cryopreservation protocol employed in this study and the low toxicity of ethylene glycol highlight the usefulness of this approach for controlled freezing of IVP embryos. However, further experiments are needed to improve the pregnancy rate following embryo transfer and to enhance survival after vitrification. Copyright 1999 Academic Press.

  20. Development of a new clinically applicable device for embryo evaluation which measures embryo oxygen consumption.

    Science.gov (United States)

    Kurosawa, Hiroki; Utsunomiya, Hiroki; Shiga, Naomi; Takahashi, Aiko; Ihara, Motomasa; Ishibashi, Masumi; Nishimoto, Mitsuo; Watanabe, Zen; Abe, Hiroyuki; Kumagai, Jin; Terada, Yukihiro; Igarashi, Hideki; Takahashi, Toshifumi; Fukui, Atsushi; Suganuma, Ryota; Tachibana, Masahito; Yaegashi, Nobuo

    2016-10-01

    Does a new system-the chip-sensing embryo respiration monitoring system (CERMs)-enable evaluation of embryo viability for potential application in a clinical IVF setting? The system enabled the oxygen consumption rate of spheroids, bovine embryos and frozen-thawed human embryos to be measured, and this rate corresponded to the developmental potential of embryos. To date, no reliable and clinically suitable objective evaluation methods for embryos are available, which circumvent the differences in inter-observer subjective view. Existing systems such as the scanning electrochemical microscopy (SECM) technique, which enables the measurement of oxygen consumption rate in embryos, need improvement in usability before they can be applied to a clinical setting. This is a prospective original research study. The feasibility of measuring the oxygen consumption rate was assessed using CERMs for 9 spheroids, 9 bovine embryos and 30 redundant frozen-thawed human embryos. The endpoints for the study were whether CERMs could detect a dissolved oxygen gradient with high sensitivity, had comparable accuracy to the SECM measuring system with improved usability, and could predict the development of an embryo to a blastocyst by measuring the oxygen consumption rate. The relationship between the oxygen consumption rate and standard morphological evaluation was also examined. We developed a new CERMs, which enables the oxygen consumption rate to be measured automatically using an electrochemical method. The device was initially used for measuring a dissolved oxygen concentration gradient in order to calculate oxygen consumption rate using nine spheroids. Next, we evaluated data correlation between the CERMs and the SECM measuring systems using nine bovine embryos. Finally, the oxygen consumption rates of 30 human embryos, which were frozen-thawed on 2nd day after fertilization, were measured by CERMs at 6, 24, 48, 72 and 96 h after thawing with standard morphological evaluation

  1. Effect of Initial Backfill Temperature on the Deformation Behavior of Early Age Cemented Paste Backfill That Contains Sodium Silicate

    Directory of Open Access Journals (Sweden)

    Aixiang Wu

    2016-01-01

    Full Text Available Enhancing the knowledge on the deformation behavior of cemented paste backfill (CPB in terms of stress-strain relations and modulus of elasticity is significant for economic and safety reasons. In this paper, the effect of the initial backfill temperature on the CPB’s stress-strain behavior and modulus of elasticity is investigated. Results show that the stress-strain relationship and the modulus of elasticity behavior of CPB are significantly affected by the curing time and initial temperature of CPB. Additionally, the relationship between the modulus of elasticity and unconfined compressive strength (UCS and the degree of hydration was evaluated and discussed. The increase of UCS and hydration degree leads to an increase in the modulus of elasticity, which is not significantly affected by the initial temperature.

  2. Development of horse embryos up to twenty two days after ovulation: observations on fresh specimens.

    Science.gov (United States)

    Betteridge, K J; Eaglesome, M D; Mitchell, D; Flood, P F; Beriault, R

    1982-01-01

    Forty nine embryos, twenty unfertilized eggs and five other fresh eggs of 'doubtful' status have been recovered from 58 pony mares in 122 flushes up to 22 days after ovulation. The fresh egg or embryo recovery rate was 78% with surgical methods (or at slaughter) and 40-60% with non-surgical methods of recovery. The fertilization rate was about 70%. It has been confirmed that horse embryos normally enter the uterus as blastocysts 5-6 days after ovulation. Three features of early embryo morphology have become clearer upon comparison with unfertilized eggs of similar ages; early embryos are often ellipsoidal in shape; dispersal of most of a thick gel coat seems to be hastened by fertilization; gradual disappearance of refractile granules from the perivitelline space is similar in fertilized and unfertilized eggs. A tense, transparent, acellular capsule (considered to be different from the zona pellucida) is acquired by the spherical blastocysts within the uterus and persists at least until a diameter of 34 mm is attained (at 21 days in the present series). The capsule seems to be analogous, in part, with the 'neozona' described in rabbit blastocyst before attachment, and trophoblastic cells appear to be involved in its formation. Cleavage stages of oviductal embryos and diameters of uterine blastocysts from this series have been described and illustrated and used to extend previous knowledge of early growth patterns in horse embryos. Images Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 Fig. 20 Fig. 21 Fig. 22 Fig. 23 Fig. 24 Fig. 25 Fig. 26 Fig. 27 Fig. 28 Fig. 29 Fig. 30 Figs. 31-32 Figs. 33-34 Fig. 35 Fig. 36 Fig. 37 Fig. 38 Fig. 39 Fig. 40 Fig. 41 PMID:7130052

  3. Identification of chromosomal errors in human preimplantation embryos with oligonucleotide DNA microarray.

    Directory of Open Access Journals (Sweden)

    Lifeng Liang

    Full Text Available A previous study comparing the performance of different platforms for DNA microarray found that the oligonucleotide (oligo microarray platform containing 385K isothermal probes had the best performance when evaluating dosage sensitivity, precision, specificity, sensitivity and copy number variations border definition. Although oligo microarray platform has been used in some research fields and clinics, it has not been used for aneuploidy screening in human embryos. The present study was designed to use this new microarray platform for preimplantation genetic screening in the human. A total of 383 blastocysts from 72 infertility patients with either advanced maternal age or with previous miscarriage were analyzed after biopsy and microarray. Euploid blastocysts were transferred to patients and clinical pregnancy and implantation rates were measured. Chromosomes in some aneuploid blastocysts were further analyzed by fluorescence in-situ hybridization (FISH to evaluate accuracy of the results. We found that most (58.1% of the blastocysts had chromosomal abnormalities that included single or multiple gains and/or losses of chromosome(s, partial chromosome deletions and/or duplications in both euploid and aneuploid embryos. Transfer of normal euploid blastocysts in 34 cycles resulted in 58.8% clinical pregnancy and 54.4% implantation rates. Examination of abnormal blastocysts by FISH showed that all embryos had matching results comparing microarray and FISH analysis. The present study indicates that oligo microarray conducted with a higher resolution and a greater number of probes is able to detect not only aneuploidy, but also minor chromosomal abnormalities, such as partial chromosome deletion and/or duplication in human embryos. Preimplantation genetic screening of the aneuploidy by DNA microarray is an advanced technology used to select embryos for transfer and improved embryo implantation can be obtained after transfer of the screened normal

  4. RESEARCHES REGARDING THE INFLUENCE OF RECOVERY MEDIA ON THE IN VITRO DEVELOPMENT CAPACITY OF THE PREIMPLANTATIONAL MOUSE EMBRYO

    Directory of Open Access Journals (Sweden)

    ADA CEAN

    2009-05-01

    Full Text Available Phosphate Bufered Saline with 0.4% BSA and M2 medium are one of the most common media used in embryorecovery. The aim of our paper was to investigate if the recovery media used for the recovery of the mouseembryo is influencing in vitro developmental capacity. As biological material we used 10 used were mousefemales, age 2 months superovulated with 5UI PMSG (Pregnant Mare Serum Gonadotropine and 5 UI hCG(human Corionic Gonadotropine. The embryos used were recovered, by oviduct flushing, at 24 hours from theidentification of the vaginal plug. The majority of the embryos (78.3% were in two cells stage. A total of 123, 2cells embryos were cultivated in M16 medium. The evolution of the embryos was examined at 24, 48 and 72hours interval. The proportion of hatched blastocyst was higher at the embryos recovered with M2 (53.7%compared with the embryos recovered with PBS 0.4% BSA. The difference is statistically very significant(p<0.001. Embryos recovered in M2 media have a higher in vitro developmental capacity compared with theembryos recovered in PBS media supplemented with 0,4% BSA, possibly because of the sodium bicarbonate andlactate used in M2 media for pH regulation.

  5. POST-HARVEST EMBRYO DEVELOPMENT IN GINSENG SEEDS INCREASES DESICCATION SENSITIVITY AND NARROWS THE HYDRATION WINDOW FOR CRYOPRESERVATION.

    Science.gov (United States)

    Han, E; Popova, E; Cho, G; Park, S; Lee, S; Pritchard, H W; Kim, H H

    Despite its self-pollinating characteristics, Korean ginseng germplasm is mainly maintained in clonal gene banks as there is no defined approach to the long-term conservation of its seed, including the most appropriate stage of embryo development for storage. The aim of this study was to reveal the effect of embryo development on desiccation tolerance and cryopreservation success in ginseng seeds. Seeds of Korean ginseng (Panax ginseng C.A. Meyer) at three post-harvest stages (immediately after harvesting and following treatments to enable internal growth of the embryo) were desiccated and cryopreserved. The hydration window for the >80% dehiscence and germination of cryopreserved ginseng seeds varied with embryo developmental stage: 3-9% moisture content (MC) for both unpulped and undehisced seeds when the embryo was 0.1 the length of the endosperm, 7-10% MC for dehisced seeds (0.5 embryo:endosperm) and 9-11% MC for seeds with fully developed embryos (0.9 embryo:endosperm). Whilst dried (4-8% moisture content) and undehisced seeds within fruits (unpulped seeds) lost more than half their viability during 1 year's storage at room temperature, cryopreservation enabled germination levels of c. 90%. Overall, 432 accessions of Korean ginseng landraces have been cryopreserved using undehisced seeds with or without fruits. Post-harvest treatment of Korean ginseng seeds to enable embryo development decreases tolerance of very low MCs, and thus narrows the hydration window for cryopreservation. Fresh-harvested and unpulped seeds that have been dried to c. 5% MC are recommended for long-term cryogenic storage.

  6. Are there optimal numbers of oocytes, spermatozoa and embryos in assisted reproduction?

    Science.gov (United States)

    Milachich, Tanya; Shterev, Atanas

    2016-08-01

    The aim of this overview is to discuss the current information about the search for the optimum yield of gametes in assisted reproduction, as one of the major pillars of IVF success. The first topic is focused on the number of male gametes and the possible impact of some genetic traits on these parameters. The number of spermatozoa did not seem to be crucial when there is no severe male factor of infertility. Genetic testing prior to using those sperm cells is very important. Different methods were applied in order to elect the "best" spermatozoa according to specific indications. The next problem discussed is the importance of the number of oocytes collected. Several studies have agreed that "15 oocytes is the perfect number," as the number of mature oocytes is more important. However, if elective single embryo transfer is performed, the optimal number of oocytes will enable a proper embryo selection. The third problem discussed concerns fertility preservation. Many educational programs promote and encourage procreation at maternal ages between 20-35 years, since assisted reproduction is unable to fully overcome the effects of female aging and fertility loss after that age. It is also strongly recommended to ensure a reasonable number of cryopreserved mature oocytes, preferably in younger ages (<35), for which an average of two stimulation cycles are likely required. For embryo cryopreservation, the "freeze all" strategy suggests the vitrification of good embryos, therefore quality is prior to number and patient recruitment for this strategy should be performed cautiously.

  7. Stage selection and restricted oviposition period improves cryopreservation of Dipteran embryos

    Science.gov (United States)

    Embryos of two dipteran species (Musca domestica, and Lucilia sericata) were assessed for an effective sampling time that would result in the highest post cryopreservation hatch proportion. Additionally, the effects of cryopreservation pretreatment viz. permeabilization, on the embryonic age and the...

  8. Viscoplastic behavior of zirconium alloys in the temperatures range 20 deg C - 400 deg C: characterization and modeling of strain ageing phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Graff, St

    2006-10-15

    The anomalous strain rate sensitivity of zirconium alloys over the temperatures range 20-600 C has been widely reported in the literature. This unconventional behavior is related to the existence of strain ageing phenomenon which results from the combined action of thermally activated diffusion of foreign atoms to and along dislocation cores and the long range of dislocations interactions. The important role of interstitial and substitutional atoms in zirconium alloys, responsible for strain ageing and the lack of information about the domain where strain ageing is active have not been yet adequately characterized because of the multiplicity of alloying elements and chemical impurities. The aim of this work is to characterize experimentally the range of temperatures and strain rates where strain ageing is active on the macroscopic and mesoscopic scales. We propose also a predictive approach of the strain ageing effects, using the macroscopic strain ageing model suggested by McCormick (McCormick, 1988; Zhang et al., 2000). Specific zirconium alloys were elaborated starting from a crystal bar of zirconium with 2.2 wt% hafnium and very low oxygen content (80 wt ppm), called ZrHf. Another substitutional atom was added to the solid solution under the form of 1 wt% niobium. Some zirconium alloys were doped with oxygen, others were not. All of them were characterized by various mechanical tests (standard tensile tests, tensile tests with strain rate changes, relaxation tests with unloading). The experimental results were compared with those for the standard oxygen doped zirconium alloy (1300 wt ppm) studied by Pujol (Pujol, 1994) and called Zr702. The following experimental evidences of the age-hardening phenomena were collected and then modeled: 1) low and/or negative strain rate sensitivity around 200-300 C, 2) creep arrest at 200 C, 3) relaxation arrest at 200 C and 300 C, 4) plastic strain heterogeneities observed in laser extensometry on the millimeter scale

  9. Arabidopsis mitochondrial protein slow embryo development1 is essential for embryo development

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Yan; Liu, Chunying; Lu, Wenwen; Zhang, Quan; Sodmergen, E-mail: sodmergn@pku.edu.cn

    2016-05-27

    The plant seeds formation are crucial parts in reproductive process in seed plants as well as food source for humans. Proper embryo development ensure viable seed formation. Here, we showed an Arabidopsis T-DNA insertion mutant slow embryo development1 (sed1) which exhibited retarded embryogenesis, led to aborted seeds. Embryo without SED1 developed slower compared to normal one and could be recognized at early globular stage by its white appearance. In later development stage, storage accumulated poorly with less protein and lipid body production. In vitro culture did not rescue albino embryo. SED1 encoded a protein targeted to mitochondria. Transmission electron microscopic analysis revealed that mitochondria developed abnormally, and more strikingly plastid failed to construct grana in time in sed1/sed1 embryo. These data indicated that SED1 is indispensable for embryogenesis in Arabidopsis, and the mitochondria may be involved in the regulation of many aspects of seed development. -- Highlights: •Arabidopsis SED1 is essential for embryo development. •The sed1 embryo accumulates less storage and has abnormal ultrastructure. •SED1 localizes to the mitochondrion.

  10. RECYCLING OF CATHETER FOR EMBRYO RECOVERY: A TOOL FOR COSTS REDUCTION IN EQUINE EMBRYO TRANSFER

    Directory of Open Access Journals (Sweden)

    Alberto Lopes Gusmao

    2010-06-01

    Full Text Available The embryo transfer is becoming a widespread practice.Most embryos are collected from spontaneous single ovulatingmares and result in 50% of embryo recovery, increasing the costsof production. To illustrate, the price of a catheter for embryosrecovery range from US$ 194.00 to US$ 250.00 (R$ 350.00 to R$450.00. Therefore, the aim of this work was to verify if catheterwith damaged balloon can be recuperated and reused withoutaltering its efficiency. For this study, two groups were used: acontrol group (GI, n=10, on which the nonsurgical recovery of theembryos of mares was performed with the catheter with originalballoon; and another group (GII, n=20, in which a restored catheterwas utilized. The mares of GI had an embryo recovery rate of60%, and GII mares had an embryo recovery rate of 55%. Therewas not statistical difference between groups I and II (P>0.05.Considering that the material used to restore the catheter costsUS$16.66 (R$30.00, this data show that the recuperation of thecatheters for embryo recovery in mares may reduce costs withoutcompromising the rates of embryo recovery.

  11. Toxicity of chlorine to zebrafish embryos

    Science.gov (United States)

    Kent, Michael L.; Buchner, Cari; Barton, Carrie; Tanguay, Robert L.

    2014-01-01

    Surface disinfection of fertilized fish eggs is widely used in aquaculture to reduce extraovum pathogens that may be released from brood fish during spawning, and this is routinely used in zebrafish (Danio rerio) research laboratories. Most laboratories use approximately 25 – 50 ppm unbuffered chlorine solution for 5 – 10 min. Treatment of embryos with chlorine has significant germicidal effects for many Gram-negative bacteria, viruses, and trophozoite stages of protozoa, it has reduced efficacy against cyst or spore stages of protozoa and certain Mycobacterium spp. Therefore, we evaluated the toxicity of unbufferred and buffered chlorine solution to embryos exposed at 6 or 24 hours post-fertilization (hpf) to determine if higher concentrations can be used for treating zebrafish embryos. Most of our experiments entailed using an outbred line (5D), with both mortality and malformations as endpoints. We found that 6 hpf embryos consistently were more resistant than 24 hpf embryos to the toxic effects of chlorine. Chlorine is more toxic and germicidal at lower pHs, and chlorine causes elevated pH. Consistent with this, we found that unbufferred chlorine solutions (pH ca 8–9) were less toxic at corresponding concentrations than solutions buffered to pH 7. Based on our findings here, we recommend treating 6 hpf embryos for 10 min and 24 hpf for 5 min with unbuffered chlorine solution at 100 ppm. One trial indicated that AB fish, a popular outbred line, are more susceptible to toxicity than 5Ds. This suggests that variability between zebrafish lines occurs, and researchers should evaluate each line or strain under their particular laboratory conditions for selection of the optimum chlorine treatment procedure. PMID:24429474

  12. Start-up of UASB reactors treating municipal wastewater and effect of temperature/sludge age and hydraulic retention time (HRT on its performance

    Directory of Open Access Journals (Sweden)

    Hina Rizvi

    2015-11-01

    Full Text Available The upflow anaerobic sludge blanket reactors seeded with cow dung manure (UASBCD and activated sludge of a dairy wastewater treatment plant (UASBASDIT were used to treat raw domestic wastewater of medium strength. The UASBCD reactor required a period of 120 days to start up. In case of UASBASDIT reactor, sludge bed was stabilized in a period of 80 days. The performance of both reactors to treat wastewater was enhanced with an increase in the sludge age and temperature. Under psychrophilic temperature (17 °C and at early sludge age (60 days, chemical oxygen demand (COD and biochemical oxygen demand (BOD removal by the reactors were in the range of 57–62% and 61–66%, respectively. However, chemical oxygen demand (COD and biochemical oxygen demand (BOD removal efficiency of the reactors elevated to the range of 79–81% and 77–83%, respectively at sludge age of 150 days and temperature of 30 °C. In short, overall performance of both reactors was optimum at sludge age ranging from 120 to 150 days and temperature varying between 25 and 30 °C. At hydraulic retention time (HRT of 9 h the chemical oxygen demand (COD, total suspended solids (TSS and sulfate removal efficiency of UASBCD reactor reached 81%, 75% and 76%, respectively and 77%, 74% and 69%, respectively for UASBASDIT. The rate of removal of these parameters however, gradually declined with increasing hydraulic retention time. The UASB technology provides a low-cost system for the direct treatment of municipal wastewater and can be applied in small communities.

  13. Serum free embryo culture medium improves in vitro survival of bovine blastocysts to vitrification

    OpenAIRE

    Gómez, E.; Rodríguez, A; Muñoz, M.; Caamaño, J.N. (José); Hidalgo, C.O. (Carlos); Morán, E.; Facal, Nieves; Díez, C.

    2013-01-01

    The aim of this study was to examine the effects of co-culture with Vero cells during the in vitro maturation (IVM) and three culture media, B2+5% fetal calf serum (FCS) on Vero cells, synthetic oviduct fluid (SOF)+5% FCS, and SOF+20 gL(-1) bovine serum albumin (BSA), on the developmental competence of the embryos and their ability to survive vitrification/warming. We also tested the effect of morphological quality and the age of the embryo on its sensitivity to vitrification. The IVM system ...

  14. Comparison of different low-temperature aging protocols: its effects on the mechanical behavior of Y-TZP ceramics

    NARCIS (Netherlands)

    Pereira, G.K.R.; Muller, C.; Wandscher, V.F.; Rippe, M.P.; Kleverlaan, C.J.; Valandro, L.F.

    2016-01-01

    This study evaluated the effect of different protocols of low-temperature degradation simulation on the mechanical behavior (structural reliability and flexural strength), the surface topography (roughness), and phase transformation of a Y-TZP ceramic. Disc-shaped specimens (1.2 mm×12 mm, Lava

  15. Effect of Different Storage Periods and Temperatures on the Hatchability of Broiler Breeder Eggs

    Directory of Open Access Journals (Sweden)

    A. Mahmud*, M. Z. U. Khan1, Saima1 and M. A. Javed

    2011-01-01

    Full Text Available Temperature and humidity have been the two most common variables used to manipulate the storage environment of hatching eggs. To ascertain the effects of different egg storage periods and temperatures on hatchability; 400 eggs were obtained from a broiler breeder flock of 32 weeks of age on a single day collection basis. These eggs were randomly divided into 5 equal groups of 80 eggs each. After collection these were cleaned, fumigated and stored on four temperatures viz 4oC, 16oC, room temperature (25oC and ambient temperature (29oC. Each group was further subdivided into 4 replicates having 20 eggs each. Eggs of Group A (control were set in incubator with temperature of 37.5oC and relative humidity 60% after the storage of one day. Eggs of rest of the four groups were set in the incubator after the storage of 3, 6, 9 and 12 days. Subsequently, these were shifted to hatchers on 18th day where the temperature and humidity were maintained at 36.5oC and 75%, respectively. The data on hatchability and dead-in-shell embryos for various groups were recorded. The results revealed that as the storage period increased at different temperatures, the hatchability decreased significantly (P<0.01. Similarly, as the storage time increased, the percentage of dead-in-shell embryos increased (P<0.01.

  16. Aging of secondary organic aerosol generated from the ozonolysis of α-pinene: effects of ozone, light and temperature

    Science.gov (United States)

    Denjean, C.; Formenti, P.; Picquet-Varrault, B.; Camredon, M.; Pangui, E.; Zapf, P.; Katrib, Y.; Giorio, C.; Tapparo, A.; Temime-Roussel, B.; Monod, A.; Aumont, B.; Doussin, J. F.

    2015-01-01

    A series of experiments was conducted in the CESAM (French acronym for Experimental Multiphasic Atmospheric Simulation Chamber) simulation chamber to investigate the evolution of the physical and chemical properties of secondary organic aerosols (SOAs) during different forcings. The present experiments represent a first attempt to comprehensively investigate the influence of oxidative processing, photochemistry, and diurnal temperature cycling upon SOA properties. SOAs generated from the ozonolysis of α-pinene were exposed under dry conditions (ozone concentrations, (2) light (under controlled temperature conditions) or (3) light and heat (6 °C light-induced temperature increase), and the resultant changes in SOA optical properties (i.e. absorption and scattering), hygroscopicity and chemical composition were measured using a suite of instrumentation interfaced to the CESAM chamber. The complex refractive index (CRI) was derived from integrated nephelometer measurements of 525 nm wavelength, using Mie scattering calculations and measured number size distributions. The particle size growth factor (GF) was measured with a hygroscopic tandem differential mobility analyzer (H-TDMA). An aerosol mass spectrometer (AMS) was used for the determination of the f44 / f43 and O : C ratio of the particles bulk. No change in SOA size or chemical composition was observed during O3 and light exposure at constant temperature; in addition, GF and CRI of the SOA remained constant with forcing. On the contrary, illumination of SOAs in the absence of temperature control led to an increase in the real part of the CRI from 1.35 (±0.03) to 1.49 (±0.03), an increase of the GF from 1.04 (±0.02) to 1.14 (±0.02) and an increase of the f44 / f43 ratio from 1.73 (±0.03) to 2.23 (±0.03). The simulation of the experiments using the master chemical mechanism (MCM) and the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) shows that these changes resulted

  17. Comet assay on thawed embryos: An optimized technique to evaluate DNA damage in mouse embryos.

    Science.gov (United States)

    Rolland, L; Courbiere, B; Tassistro, V; Sansoni, A; Orsière, T; Liu, W; Di Giorgio, C; Perrin, J

    2017-10-01

    Our objective was to optimize the CA technique on mammal embryos. 1000 frozen 2-cell embryos from B6CBA mice were used. Based on a literature review, and after checking post-thaw embryo viability, the main outcome measures included: 1) comparison of the embryo recovery rate between 2 CA protocols (2 agarose layers and 3 agarose layers); 2) comparison of DNA damage by the CA on embryos with (ZP+) and without (ZP-) zona pellucida; and 3) comparison of DNA damage in embryos exposed to 2 genotoxic agents (H2O2 and simulated sunlight irradiation (SSI)). DNA damage was quantified by the % tail DNA. 1) The recovery rate was 3,3% (n=5/150) with the 2 agarose layers protocol and 71,3% (n=266/371) with the 3 agarose layers protocol. 2) DNA damage did not differ statistically significantly between ZP- and ZP+ embryos (12.60±2.53% Tail DNA vs 11.04±1.50 (p=0.583) for the control group and 49.23±4.16 vs 41.13±4.31 (p=0.182) for the H2O2 group); 3) H2O2 and SSI induced a statistically significant increase in DNA damage compared with the control group (41.13±4.31% Tail DNA, 36.33±3.02 and 11.04±1.50 (p<0.0001)). The CA on mammal embryos was optimized by using thawed embryos, by avoiding ZP removal and by the adjunction of a third agarose layer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. To transfer fresh or thawed embryos?

    DEFF Research Database (Denmark)

    Pinborg, Anja

    2012-01-01

    and multiple pregnancies, thereby increasing the safety for mother and child. Finally the article describes the accumulating literature on perinatal and long-term child outcome after transfer of frozen/thawed embryos, including a discussion on the concerns regarding cryo techniques and their possible roles...... and cons of FER versus fresh-embryo transfer with regard to both single-cycle and cumulative pregnancy and delivery rates. The review discusses the obvious advantages of FER: minimizing the proportion of pharmacological and surgical treatments, and lowering the risk of ovarian hyperstimulation syndrome...

  19. Transcriptome analysis of embryo maturation in maize.

    Science.gov (United States)

    Teoh, Keat Thomas; Requesens, Deborah Vicuna; Devaiah, Shivakumar P; Johnson, Daniel; Huang, Xiuzhen; Howard, John A; Hood, Elizabeth E

    2013-02-04

    Maize is one of the most important crops in the world. With the exponentially increasing population and the need for ever increased food and feed production, an increased yield of maize grain (as well as rice, wheat and other grains) will be critical. Maize grain development is understood from the perspective of morphology, hormone responses, and storage reserve accumulation. This includes various studies on gene expression during embryo development and maturation but a global study of gene expression of the embryo has not been possible until recently. Transcriptome analysis is a powerful new tool that can be used to understand the genetic basis of embryo maturation. We undertook a transcriptomic analysis of normal maturing embryos at 15, 21 and 27 days after pollination (DAP), of one elite maize germplasm line that was utilized in crosses to transgenic plants. More than 19,000 genes were analyzed by this method and the challenge was to select subsets of genes that are vitally important to embryo development and maturation for the initial analysis. We describe the changes in expression for genes relating to primary metabolic pathways, DNA synthesis, late embryogenesis proteins and embryo storage proteins, shown through transcriptome analysis and confirmed levels of transcription for some genes in the transcriptome using qRT-PCR. Numerous genes involved in embryo maturation have been identified, many of which show changes in expression level during the progression from 15 to 27 DAP. An expected array of genes involved in primary metabolism was identified. Moreover, more than 30% of transcripts represented un-annotated genes, leaving many functions to be discovered. Of particular interest are the storage protein genes, globulin-1, globulin-2 and an unidentified cupin family gene. When expressing foreign proteins in maize, the globulin-1 promoter is most often used, but this cupin family gene has much higher expression and may be a better candidate for foreign gene

  20. Effects of aging time and annealing temperature on structural and optical properties of sol-gel ZnO thin films

    Directory of Open Access Journals (Sweden)

    Jitao Li

    2017-06-01

    Full Text Available The ZnO thin films have been prepared by sol-gel method at different annealing temperatures and aging time. The structural properties of ZnO thin films were investigated by X-ray diffraction (XRD patterns and atomic force microscope (AFM images. The results indicated that the film possess a hexagonal wurtzite structure with preferred orientation along the (002 direction. The crystalline quality of films improved with increasing post-annealing temperature, while gradually worsened with prolonging aging time. The optical properties of ZnO thin films were studied by the ultra-violet transmittance (UV-Vis and photoluminescence (PL spectra. The variations of UV-Vis transmittance and energy gap accorded well with the tendency presented in XRD patterns and AFM images. The PL spectra appeared the apparent ultraviolet emission and visible emissions. As the annealing temperature increased, the ultraviolet and visible emissions of films enhanced and decreased respectively. However, as the sol aging time prolonged, the PL emission presented an opposite tendency.

  1. Dehydroepiandrosterone (DHEA) reduces embryo aneuploidy: direct evidence from preimplantation genetic screening (PGS).

    Science.gov (United States)

    Gleicher, Norbert; Weghofer, Andrea; Barad, David H

    2010-11-10

    Dehydroepiandrosterone (DHEA) has been reported to improve pregnancy chances in women with diminished ovarian reserve (DOR), and to reduce miscarriage rates by 50-80%. Such an effect is mathematically inconceivable without beneficial effects on embryo ploidy. This study, therefore, assesses effects of DHEA on embryo aneuploidy. In a 1:2, matched case control study 22 consecutive women with DOR, supplemented with DHEA, underwent preimplantation genetic screening (PGS) of embryos during in vitro fertilization (IVF) cycles. Each was matched by patient age and time period of IVF with two control IVF cycles without DHEA supplementation (n = 44). PGS was performed for chromosomes X, Y, 13, 16, 18, 21 and 22, and involved determination of numbers and percentages of aneuploid embryos. DHEA supplementation to a significant degree reduced number (P = 0.029) and percentages (P DHEA effects on DOR patients, at least partially, are the likely consequence of lower embryo aneuploidy. DHEA supplementation also deserves investigation in older fertile women, attempting to conceive, where a similar effect, potentially, could positively affect public health.

  2. Effect of oxygen concentration on human embryo development evaluated by time-lapse monitoring

    DEFF Research Database (Denmark)

    Ingerslev, Hans Jakob; Hindkjær, Johnny Juhl; Kirkegaard, Kirstine

    2012-01-01

    was to evaluate the influence of oxygen tension on human pre-implantation development using time-lapse monitoring. Materials and methods: Human embryos were cultured to the blastocyst stage in a time-lapse incubator (EmbryoScope™) in 20% O2 (group 1), 20% O2 for 24 hours followed by culture in 5% O2 (group 2......) or in 5% O2 (group 3). Eligible were patients with age 8 oocytes retrieved. Group 1 consisted of 120 IVF/ICSI embryos from 26 patients recruited to a study conducted to evaluate the safety of the time-lapse incubator by randomising 1:1 embryos from a patient to culture......-points for each cell division and blastocyst stages were registered until 120 hours after oocyte retrieval. Only 2PN embryos completing the first cleavage were evaluated. The groups were compared using one-way ANOVA or Kruskall-Wallis test. Estimates are reported as medians with 95% confidence intervals. Time...

  3. Dehydroepiandrosterone (DHEA reduces embryo aneuploidy: direct evidence from preimplantation genetic screening (PGS

    Directory of Open Access Journals (Sweden)

    Weghofer Andrea

    2010-11-01

    Full Text Available Abstract Background Dehydroepiandrosterone (DHEA has been reported to improve pregnancy chances in women with diminished ovarian reserve (DOR, and to reduce miscarriage rates by 50-80%. Such an effect is mathematically inconceivable without beneficial effects on embryo ploidy. This study, therefore, assesses effects of DHEA on embryo aneuploidy. Methods In a 1:2, matched case control study 22 consecutive women with DOR, supplemented with DHEA, underwent preimplantation genetic screening (PGS of embryos during in vitro fertilization (IVF cycles. Each was matched by patient age and time period of IVF with two control IVF cycles without DHEA supplementation (n = 44. PGS was performed for chromosomes X, Y, 13, 16, 18, 21 and 22, and involved determination of numbers and percentages of aneuploid embryos. Results DHEA supplementation to a significant degree reduced number (P = 0.029 and percentages (P Discussion Beneficial DHEA effects on DOR patients, at least partially, are the likely consequence of lower embryo aneuploidy. DHEA supplementation also deserves investigation in older fertile women, attempting to conceive, where a similar effect, potentially, could positively affect public health.

  4. Morphometric analysis of human embryos to predict developmental competence

    DEFF Research Database (Denmark)

    Ziebe, Søren

    2013-01-01

    Morphometric and morphokinetic approaches toward embryo quality assessment have for many years been difficult due to technical limitations. Today, with improvements in laboratory techniques and subsequent quality, we have a better understanding of the morphometric and kinetics of embryo development...

  5. Cryopreservation of embryos and oocytes in human assisted reproduction.

    Science.gov (United States)

    Konc, János; Kanyó, Katalin; Kriston, Rita; Somoskői, Bence; Cseh, Sándor

    2014-01-01

    Both sperm and embryo cryopreservation have become routine procedures in human assisted reproduction and oocyte cryopreservation is being introduced into clinical practice and is getting more and more widely used. Embryo cryopreservation has decreased the number of fresh embryo transfers and maximized the effectiveness of the IVF cycle. The data shows that women who had transfers of fresh and frozen embryos obtained 8% additional births by using their cryopreserved embryos. Oocyte cryopreservation offers more advantages compared to embryo freezing, such as fertility preservation in women at risk of losing fertility due to oncological treatment or chronic disease, egg donation, and postponing childbirth, and eliminates religious and/or other ethical, legal, and moral concerns of embryo freezing. In this review, the basic principles, methodology, and practical experiences as well as safety and other aspects concerning slow cooling and ultrarapid cooling (vitrification) of human embryos and oocytes are summarized.

  6. Using fertile couples as embryo donors: An ethical dilemma.

    Science.gov (United States)

    Alizadeh, Leila; Omani Samani, Reza

    2014-03-01

    The use of donated embryos has offered hope for infertile couples who have no other means to have children. In Iran, fertility centers use fertile couples as embryo donors. In this paper, the advantages and disadvantages of this procedure will be discussed. We conclude that embryo-donation should be performed with frozen embryos thus preventing healthy donors from being harmed by fertility drugs. There must be guidelines for choosing the appropriate donor families. In countries where commercial egg donation is acceptable, fertile couples can be procured as embryo donors thus fulfilling the possible shortage of good quality embryos. Using frozen embryos seems to have less ethical, religious and legal problems when compared to the use of fertile embryo donors.

  7. [Ectopic pregnancy following in vitro fertilization and embryo transfer].

    Science.gov (United States)

    Sudik, R; Fliess, F R; Bernt, W D; Meissner, J; Kunkel, S

    1984-01-01

    A report is given about one case of ectopic pregnancy after in vitro fertilization and transfer of three embryos. Possible causes of ectopic pregnancies following embryo transfer and conclusions are discussed.

  8. Advances in embryo culture platforms: novel approaches to improve preimplantation embryo development through modifications of the microenvironment.

    Science.gov (United States)

    Swain, J E; Smith, G D

    2011-01-01

    The majority of research aimed at improving embryo development in vitro has focused on manipulation of the chemical environment, examining details such as energy substrate composition and impact of various growth factors or other supplements. In comparison, relatively little work has been done examining the physical requirements of preimplantation embryos and the role culture platforms or devices can play in influencing embryo development. Electronic searches were performed using keywords centered on embryo culture techniques using PUBMED through June 2010 and references were searched for additional research articles. Various approaches to in vitro embryo culture that involve manipulations of the physical culture environment are emerging. Novel culture platforms being developed examine issues such as media volume and embryo spacing. Furthermore, methods to permit dynamic embryo culture with fluid flow and embryo movement are now available, and novel culture surfaces are being tested. Although several factors remain to be studied to optimize efficiency, manipulations of the embryo culture microenvironment through novel culture devices may offer a means to improve embryo development in vitro. Reduced volume systems that reduce embryo spacing, such as the well-of-the-well approach, appear beneficial, although more work is needed to verify the source of their true benefit in human embryos. Emerging microfluidic technology appears to be a promising approach. However, along with the work on specialized culture surfaces, more information is required to determine the impact on human embryo development.

  9. Sourcing human embryos for embryonic stem cell lines: Problems & perspectives

    Directory of Open Access Journals (Sweden)

    Rajvi H Mehta

    2014-01-01

    Full Text Available The ability to successfully derive human embryonic stem cells (hESC lines from human embryos following in vitro fertilization (IVF opened up a plethora of potential applications of this technique. These cell lines could have been successfully used to increase our understanding of human developmental biology, transplantation medicine and the emerging science of regenerative medicine. The main source for human embryos has been ′discarded′ or ′spare′ fresh or frozen human embryos following IVF. It is a common practice to stimulate the ovaries of women undergoing any of the assisted reproductive technologies (ART and retrieve multiple oocytes which subsequently lead to multiple embryos. Of these, only two or maximum of three embryos are transferred while the rest are cryopreserved as per the decision of the couple. In case a couple does not desire to ′cryopreserve′ their embryos then all the embryos remaining following embryo transfer can be considered ′spare′ or if a couple is no longer in need of the ′cryopreserved′ embryos then these also can be considered as ′spare′. But, the question raised by the ethicists is, "what about ′slightly′ over-stimulating a woman to get a few extra eggs and embryos? The decision becomes more difficult when it comes to ′discarded′ embryos. As of today, the quality of the embryos is primarily assessed based on morphology and the rate of development mainly judged by single point assessment. Despite many criteria described in the literature, the quality assessment is purely subjective. The question that arises is on the decision of ′discarding′ embryos. What would be the criteria for discarding embryos and the potential ′use′ of ESC derived from the ′abnormal appearing′ embryos? This paper discusses some of the newer methods to procure embryos for the derivation of embryonic stem cell lines which will respect the ethical concerns but still provide the source material.

  10. Embryo transfer and related technologies in sheep reproduction

    OpenAIRE

    Loi, Pasqualino; Ptak, Grazyna; Dattena, Maria; Ledda, Sergio; Naitana, Salvatore; Cappai, Pietro

    1998-01-01

    This paper reviews the status of embryo transfer and the major technologies applied to preimplantation of embryos in sheep. Embryo production from superovulated ewes is hindered by an unpredictable response to hormonal treatment. Progress in this area should be expected by an appropriated control of follicular development with gonadotropin-releasing hormone (GnRH) agonist or antagonist prior to gonadotrophin administration. Simple protocols for the cryopreservation of sheep embryos by vitrifi...

  11. Monazite trumps zircon: applying SHRIMP U-Pb geochronology to systematically evaluate emplacement ages of leucocratic, low-temperature granites in a complex Precambrian orogen

    Science.gov (United States)

    Piechocka, Agnieszka M.; Gregory, Courtney J.; Zi, Jian-Wei; Sheppard, Stephen; Wingate, Michael T. D.; Rasmussen, Birger

    2017-08-01

    Although zircon is the most widely used geochronometer to determine the crystallisation ages of granites, it can be unreliable for low-temperature melts because they may not crystallise new zircon. For leucocratic granites U-Pb zircon dates, therefore, may reflect the ages of the source rocks rather than the igneous crystallisation age. In the Proterozoic Capricorn Orogen of Western Australia, leucocratic granites are associated with several pulses of intracontinental magmatism spanning 800 million years. In several instances, SHRIMP U-Pb zircon dating of these leucocratic granites either yielded ages that were inconclusive (e.g., multiple concordant ages) or incompatible with other geochronological data. To overcome this we used SHRIMP U-Th-Pb monazite geochronology to obtain igneous crystallisation ages that are consistent with the geological and geochronological framework of the orogen. The U-Th-Pb monazite geochronology has resolved the time interval over which two granitic supersuites were emplaced; a Paleoproterozoic supersuite thought to span 80 million years was emplaced in less than half that time (1688-1659 Ma) and a small Meso- to Neoproterozoic supersuite considered to have been intruded over 70 million years was instead assembled over 130 million years and outlasted associated regional metamorphism by 100 million years. Both findings have consequences for the duration of associated orogenic events and any estimates for magma generation rates. The monazite geochronology has contributed to a more reliable tectonic history for a complex, long-lived orogen. Our results emphasise the benefit of monazite as a geochronometer for leucocratic granites derived by low-temperature crustal melting and are relevant to other orogens worldwide.

  12. Sexing bovine pre-implantation embryos using the polymerase ...

    African Journals Online (AJOL)

    The paper aims to present a bovine model for human embryo sexing. Cows were super-ovulated, artificially inseminated and embryos were recovered 7 days later. Embryo biopsy was performed; DNA was extracted from blastomeres and amplified using bovine-specific and bovine-Y-chromosomespecific primers, followed ...

  13. Bovine in-vitro embryo production and its contribution towards ...

    African Journals Online (AJOL)

    Mimi

    ... of the Kenyan livestock farmers and boost food security. It discusses the technical aspects of the procedures involved in the in-vitro production of bovine embryos and embryo transfer, with special reference to the application of the techniques in Kenya. MATERIALS AND METHODS. Production of embryos in the laboratory ...

  14. Endometrial preparation methods in frozen-thawed embryo transfer

    NARCIS (Netherlands)

    Groenewoud, E.R.

    2017-01-01

    One in six couples suffer from infertility, and many undergo treatment with in-vitro fertilization (IVF). Given that IVF often results in more embryos than can be transferred during one embryo transfer cryopreservation of the supernumerary embryos has been an important addition to IVF. In recent

  15. Retrograde tubal transfer of human embryos.

    Science.gov (United States)

    Risquez, F; Boyer, P; Rolet, F; Magnani, M; Guichard, A; Cedard, L; Zorn, J R

    1990-02-01

    This preliminary study was designed to evaluate retrograde cannulation of the Fallopian tubes up to the isthmo-interstitial junction using the new technique of tubal embryo stage transfer (TEST). Follicular aspiration was performed under the guidance of a vaginal ultrasound probe in 51 women treated with GnRH + HMG. The oocytes retrieved were inseminated in vitro with 50,000 motile spermatozoa and kept in Menezo B2 medium without serum, at 37 degrees C, in an atmosphere of air + 5% CO2. The eggs were checked 24 and 36 h after insemination. No fertilization occurred in 23 patients. Cleaved embryos were obtained in the 28 other patients. One to seven embryos at the 2-4-cell stage were transferred with the 'Baudelocque Black Catheter' (BBC) into one tube and spare embryos were frozen. Five pregnancies occurred after retrograde TEST, for a pregnancy rate of 9.8% per cycle and 17.9% per transfer. One patient has given birth to a normal full-term baby. One singleton and one twin pregnancy are ongoing (8 months in June 1989). The other two pregnancies were ectopic.

  16. Effects of fluoxetine on human embryo development

    NARCIS (Netherlands)

    Kaihola, Helena; Yaldir, Fatma G.; Hreinsson, Julius; Hornaeus, Katarina; Bergquist, Jonas; Olivier, Jocelien D. A.; Akerud, Helena; Sundstrom-Poromaa, Inger

    2016-01-01

    The use of antidepressant treatment during pregnancy is increasing, and selective serotonin reuptake inhibitors (SSRIs) are the most widely prescribed antidepressants in pregnant women. Serotonin plays a role in embryogenesis, and serotonin transporters are expressed in two-cell mouse embryos. Thus,

  17. Culture of Cells from Amphibian Embryos.

    Science.gov (United States)

    Stanisstreet, Martin

    1983-01-01

    Describes a method for in vitro culturing of cells from amphibian early embryos. Such cells can be used to demonstrate such properties of eukaryote cells as cell motility, adhesion, differentiation, and cell sorting into tissues. The technique may be extended to investigate other factors. (Author/JN)

  18. Genetic transformation of olive somatic embryos through ...

    African Journals Online (AJOL)

    Administrator

    2011-06-20

    Jun 20, 2011 ... Full Length Research Paper. Genetic transformation of olive somatic embryos through Agrobacterium tumefaciens and regeneration of transgenic plants. Mahboobeh Jafarzadeh-Bajestani 1#, Maryam Khodai-Kalaki 1#, Nasrin Motamed1*, Omidreza. Noorayin2. 1The University College of science, Faculty ...

  19. Transcervical Embryo recovery by transcervical technique in ...

    African Journals Online (AJOL)

    Vicente Freitas

    Laboratory of Physiology and Control of Reproduction, State University of Ceará - Faculty of Veterinary Science. Fortaleza - CE, 60.740-000, .... Data of recovered embryos were transformed to a log function and the means were compared by ANOVA followed by .... prostaglandin F2α and oxytocin. J. Anim. Sci. 76, 360-363.

  20. The endometrial factor in human embryo implantation

    NARCIS (Netherlands)

    Boomsma, C.M.

    2009-01-01

    The studies presented in this thesis aimed to explore the role of the endometrium in the implantation process. At present, embryo implantation is the major rate-limiting step for success in fertility treatment. Clinicians have sought to develop clinical interventions aimed at enhancing implantation

  1. Mapping selection within Drosophila melanogaster embryo's anatomy

    DEFF Research Database (Denmark)

    Salvador-Martínez, Irepan; Coronado-Zamora, Marta; Castellano, David

    2018-01-01

    We present a survey of selection across Drosophila melanogaster embryonic anatomy. Our approach integrates genomic variation, spatial gene expression patterns and development, with the aim of mapping adaptation over the entire embryo's anatomy. Our adaptation map is based on analyzing spatial gene...

  2. Formation of planetary embryos from planetesimals

    Science.gov (United States)

    Rafikov, Roman Ravilevich

    This thesis is devoted to studying some aspects of the formation of terrestrial planets. Although it is currently widely accepted that terrestrial planets form by agglomeration of a large number of rocky or icy bodies called planetesimals there is still a number of unresolved issues hindering our understanding of this process. I concentrate my research on the dynamical interaction of planetesimal disk with the planetary embryos—precursors of protoplanets. I investigate the development of nonuniformities in the planetesimal disk using analytical techniques employing the methods of statistical mechanics, which is justified by the huge number of planetesimals under consideration. This treatment self-consistently accounts for the evolution of the planetesimal kinematic properties, which is coupled to spatial redistribution of planetesimals in the disk. Planetesimal-planetesimal and embryo- planetesimal interactions are studied in two different velocity regimes: when the average approach velocities of interacting bodies are dominated by their epicyclic motion (dispersion-dominated regime) and when they are dominated by the differential shear in the disk (shear- dominated regime). The intermediate regime is modeled by interpolation. I show that the embryo always tries to repel planetesimals away and produce a depression in planetesimal surface density around its semimajor axis, while the planetesimal-planetesimal scattering acts as a source of effective viscosity which opposes this tendency and tries to smooth any inhomogeneities in the disk. The mutual gravitational interaction between planetesimals also increases their epicyclic motion throughout the disk. Embryo-planetesimal interaction leads to the same dynamical effect but localized spatially in the narrow zone around the embryo's orbit. The formation of inhomogeneities and excitation of planetesimal epicyclic motion in the disk nearby strongly affects the accretion rate of the embryo. I demonstrate that the

  3. Differentiation and thermal history of the post-collapse magma reservoir at Yellowstone caldera as revealed by combining the temperature-age-compositional history of zircons

    Science.gov (United States)

    Vazquez, J. A.; Reid, M. R.; Kyriazis, S. F.

    2006-12-01

    Coupling the age and compositional history recorded between and within single accessory minerals, such as zircon or allanite, may provide a high-resolution perspective on the thermochemical evolution of voluminous magma reservoirs in the prelude to eruption. At Yellowstone caldera, USA, more than 900km3 of high- silica rhyolite erupted sequentially in the aftermath of caldera collapse from an evolving magma reservoir. At least 21 lavas and tuffs comprise the voluminous Central Plateau Member (CPM) of the Plateau Rhyolite which erupted between 160 ka and 70 ka. 238U-230Th disequilibrium and U-Pb dating reveal that CPM zircons crystallized approximately 0 to 60 thousand years prior to their respective K-Ar eruption ages, and contain little inheritance from the caldera-forming magma. To obtain a temperature-time-compositional history for CPM zircons and evaluate the applicability of the zircon thermometry to high-silica rhyolites, we performed ion microprobe analyses of trace element concentrations in >65 of the dated zircons from four lavas representing early, middle, and late tapping of the CPM reservoir. Most CPM zircons contain typical REE patterns with chondrite-normalized Lu/La of up to 30,000, and with Eu/Eu* as low as 0.03. A subset of the results (~45%) yield elevated light REE, Ti, and Fe concentrations where sampled zircon domains included small inclusions of Fe-Ti oxides, chevkinite, and/or monazite. Application of Ti-in-zircon thermometry to dated zircons that are unaffected by inclusions yield temperatures that have a range of approximately 70 degrees. Calculated temperatures would largely fall within the range of 800°-840°C for CPM magmas obtained by Zr-glass, zircon saturation, and QUILF thermometry if an essentially fixed melt aTiO2 of 0.3 due to ilmenite saturation is assumed. Where analyzed, the rims of single zircons yield temperatures that are 10°-20° lower than their cores. Our combination of zircon thermometry, age, and composition reveals

  4. Hematocrit and blood osmolality in developing chicken embryos (Gallus gallus): in vivo and in vitro regulation.

    Science.gov (United States)

    Andrewartha, Sarah J; Tazawa, Hiroshi; Burggren, Warren W

    2011-12-15

    Hematocrit (Hct) regulation is a complex process involving potentially many factors. How such regulation develops in vertebrate embryos is still poorly understood. Thus, we investigated the role of blood pH in the regulation of Hct across developmental time in chicken embryos. We hypothesized that blood pH alterations in vitro (i.e., in a test tube) would affect Hct far more than in vivo because of in vivo compensatory regulatory processes for Hct. Large changes in Hct (through mean corpuscular volume (MCV)) and blood osmolality (Osm) occur when the blood was exposed to varying ambient temperatures (T(a)'s) and P(CO2) in vitro alongside an experimentally induced blood pH change from ~7.3 to 8.2. However, homeostatic regulatory mechanisms apparently limited these alterations in vivo. Changes in blood pH in vitro were accompanied by hydration or dehydration of red blood cells depending on embryonic age, resulting in changes in Hct that also were specific to developmental stage, due likely to initial blood gas and [HCO(3)(-)](v) values. Significant linear relationships between Hct and pH (Hct/ΔpH=-21.4%/(pH unit)), Hct and [HCO(3)(-)] (ΔHct/Δ[HCO(3)(-)]=1.6%/(mEq L(-1))) and the mean buffer value (Δ[HCO(3)(-)]/ΔpH=-13.4 (mEq L(-1))/(pH unit)) demonstrate that both pH and [HCO(3)(-)] likely play a role in the regulation of Hct through MCV at least in vitro. Low T(a) (24°C) resulted in relatively large changes in pH with small changes in Hct and Osm in vitro with increased T(a) (42°C) conversely resulting in larger changes in both Hct and Osm. In vivo exposure to altered T(a) caused age-dependent changes in Hct, demonstrating a trend towards increased Hct at higher T(a). Further, exposing embryos to a gas mixture where P(CO2) = 5.1 kPa for >4 h period at T(a) of 37 or 42°C also did not elicit a change in Hct or Osm. Presumably, homeostatic mechanisms ensured that in vivo Hct was stable during a 4-6 h temperature and/or hypercapnic stress. Thus, although blood p

  5. The effects of host age, host nuclear background and temperature on phenotypic effects of the virulent Wolbachia strain popcorn in Drosophila melanogaster.

    Science.gov (United States)

    Reynolds, K Tracy; Thomson, Linda J; Hoffmann, Ary A

    2003-07-01

    Because of their obligate endosymbiotic nature, Wolbachia strains by necessity are defined by their phenotypic effects upon their host. Nevertheless, studies on the influence of host background and environmental conditions upon the manifestation of Wolbachia effects are relatively uncommon. Here we examine the behavior of the overreplicating Wolbachia strain popcorn in four different Drosophila melanogaster backgrounds at two temperatures. Unlike other strains of Wolbachia in Drosophila, popcorn has a major fitness impact upon its hosts. The rapid proliferation of popcorn causes cells to rupture, resulting in the premature death of adult hosts. Apart from this effect, we found that popcorn delayed development time, and host background influenced both this trait and the rate of mortality associated with infection. Temperature influenced the impact of popcorn upon host mortality, with no reduction in life span occurring in flies reared at 19 degrees. No effect upon fecundity was found. Contrary to earlier reports, popcorn induced high levels of incompatibility when young males were used in tests, and CI levels declined rapidly with male age. The population dynamics of popcorn-type infections will therefore depend on environmental temperature, host background, and the age structure of the population.

  6. Association between growth dynamics, morphological parameters, the chromosomal status of the blastocysts, and clinical outcomes in IVF PGS cycles with single embryo transfer.

    Science.gov (United States)

    Barash, Oleksii O; Ivani, Kristen A; Willman, Susan P; Rosenbluth, Evan M; Wachs, Deborah S; Hinckley, Mary D; Pittenger Reid, Sara; Weckstein, Louis N

    2017-08-01

    The purpose of the present study is to examine interconnection between speed of embryo development, the genetic status of the blastocysts, and clinical outcomes in IVF preimplantation genetic screening (PGS) cycles with single embryo transfer (SET). The retrospective comparative study has been performed between January 2013 and January 2016. Seven hundred thirty-seven cycles of IVF treatment with PGS, followed by 503 SETs, were included in the study. Normally fertilized oocytes were hatched on day 3, were cultured to the blastocyst stage, and were biopsied only when at least three to seven cells were herniating from zona pellucida on the morning of day 5 (≤118 h) or day 6 (≥139 h). A total of 3705 embryos were analyzed for euploidy rates and blastocyst morphology. All embryos were vitrified after the biopsy, and selected embryos were subsequently thawed for a hormone replacement frozen embryo transfer cycle. The euploidy rate was significantly higher among embryos biopsied on day 5 versus day 6: 59.44 ± 4.1 and 48.19 ± 3.8, respectively, p < 0.05. The difference in euploidy rates between embryos biopsied on day 5 versus day 6 in matched age groups increased from 5.83 to 25.46% with advancing maternal age. Our data demonstrated no statistically significant difference in euploidy rates between good-quality embryos biopsied on day 5 in the group of patients <38 years old and embryos in PGS cycles using donor oocytes: 71.12% (336/472) and 75.68% (221/292), respectively, p = 0.174, χ (2) = 1.848. In 270 out of 503 SETs, transferred embryos were biopsied on day 5 (ongoing pregnancy rate was 64.6% in a group of patients <38 years old, and in a group of patients ≥38 years old, ongoing PR was 64.2%). In 233 out of 503 cycles, transferred embryos were biopsied on day 6 (ongoing PR was 46.6% in a group of patients <38 years old, and in a group of patients ≥38 years old, ongoing PR was 50.8%). In all study groups, the ongoing pregnancy rate was

  7. Thermal aging of traditional and additively manufactured foams: analysis by time-temperature-superposition, constitutive, and finite-element models

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Weisgraber, T. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Small, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lewicki, J. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Duoss, E. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Spadaccini, C. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pearson, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chinn, S. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wilson, T. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Maxwell, R. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-12-08

    Cellular solids or foams are a very important class of materials with diverse applications ranging from thermal insulation and shock absorbing support cushions, to light-weight structural and floatation components, and constitute crucial components in a large number of industries including automotive, aerospace, electronics, marine, biomedical, packaging, and defense. In many of these applications the foam material is subjected to long periods of continuous stress, which can, over time, lead to a permanent change in structure and a degradation in performance. In this report we summarize our modeling efforts to date on polysiloxane foam materials that form an important component in our systems. Aging of the materials was characterized by two measured quantities, i.e., compression set and load retention. Results of accelerated aging experiments were analyzed by an automated time-temperaturesuperposition (TTS) approach, which creates a master curve that can be used for long-term predictions (over decades) under ambient conditions. When comparing such master curves for traditional (stochastic) foams with those for recently 3D-printed (i.e., additively manufactured, or AM) foams, it became clear that AM foams have superior aging behavior. To gain deeper understanding, we imaged the microstructure of both foams using X-ray computed tomography, and performed finite-element analysis of the mechanical response within these microstructures. This indicates a wider stress variation in the stochastic foam with points of more extreme local stress as compared to the 3D printed material.

  8. The fate of the mosaic embryo: Chromosomal constitution and development of Day 4, 5 and 8 human embryos

    NARCIS (Netherlands)

    M.A. Santos; G. Teklenburg (Gijs); N.S. Macklon (Nick); D. van Opstal (Diane); G.H. Schuring-Blom (Heleen); P-J. Krijtenburg (Pieter-Jaap); J. de Vreeden-Elbertse (Johanna); B.C.J.M. Fauser (Bart); E.B. Baart (Esther)

    2010-01-01

    textabstractBackground: Post-zygotic chromosome segregation errors are very common in human embryos after in vitro fertilization, resulting in mosaic embryos. However, the significance of mosaicism for the developmental potential of early embryos is unknown. We assessed chromosomal constitution and

  9. Gender, Age and Season as Modifiers of the Effects of Diurnal Temperature Range on Emergency Room Admissions for Cause-Specific Cardiovascular Disease among the Elderly in Beijing.

    Science.gov (United States)

    Zheng, Shan; Wang, Minzhen; Li, Bei; Wang, Shigong; He, Shilin; Yin, Ling; Shang, Kezheng; Li, Tanshi

    2016-04-27

    Diurnal temperature range (DTR) is an important index of climate change and variability. It is also a risk factor affecting human health. However, limited evidence is available to illustrate the effect of DTR modification on cause-specific cardiovascular disease among the elderly. A semi-parametric generalized additive model (GAM) was used to analyze the exposure-effect relationship between DTR and daily emergency room (ER) admissions for cause-specific cardiovascular diseases among the elderly from 2009 to 2011 in Beijing. We examined the effects of DTR for stratified groups by gender and age, and examined the effects of DTR in the warm season and cold season for cause-specific cardiovascular diseases. Significant associations were found between DTR and ER admissions for all cardiovascular and cerebrovascular disease among elderly males, while DTR was significantly associated with ER admissions for all cardiovascular disease, ischemic heart disease and cerebrovascular disease among elderly females. People aged 75 years and older were more vulnerable to DTR. DTR caused greater adverse effects on both genders in the warm season, whereas the effect estimates on females were higher in cold season than in warm season. A short-term increase of DTR was significantly associated with ER admissions for cause-specific cardiovascular disease among the elderly in Beijing. Gender, age and season may modify the acute health effect of DTR. Some prevention programs that target the high risk subgroups in the elderly for impending large temperature changes may reduce the impact of DTR on people's health.

  10. Effect of Aging, Antioxidant, and Mono- and Divalent Ions at High Temperature on the Rheology of New Polyacrylamide-Based Co-Polymers

    Directory of Open Access Journals (Sweden)

    Saeed Akbari

    2017-10-01

    Full Text Available The viscosity of four new polymers was investigated for the effect of aging at high temperature, with varying degrees of salinity and hardness. The four sulfonated based polyacrylamide co-polymers were FLOCOMB C7035; AN132 VHM; SUPERPUSHER SAV55; and THERMOASSOCIATIF copolymers. All polymer samples were aged at 80 °C for varying times (from zero to at least 90 days with and without isobutyl alcohol (IBA as an antioxidant. To see the effect of divalent ions on the polymer solution viscosity, parallel experiments were performed in a mixture of CaCl2-NaCl of the same ionic strength as 5 wt % NaCl. The polymers without IBA showed severe viscosity reduction after aging for 90 days in both types of preparation (5 wt % NaCl or CaCl2-NaCl. In the presence of IBA, viscosity was increased when aging time was increased for 5 wt % NaCl. In CaCl2-NaCl, on the other hand, a viscosity reduction was observed as aging time was increased. This behavior was observed for all polymers except AN132 VHM.

  11. Effects of developmental age, ambient temperature, and dietary alterations on delta(12) desaturase activity in the house cricket, Acheta domesticus.

    Science.gov (United States)

    Batcabe, J P; Howell, J D; Blomquist, G J; Borgeson, C E

    2000-07-01

    Double bond formation in polyunsaturated fatty acids (PUFA) is mediated by desaturase enzymes. Certain insect species have been found to possess a Delta(12) desaturase, previously thought to occur exclusively in plants. We have begun to characterize this enzyme to determine its relatedness to those found in plants and animals. Desaturase activity can be altered significantly by a number of environmental factors in protozoa, cyanobacteria, plants, fish, and rats. We present evidence here that Delta(12) desaturase activity in Acheta domesticus is affected by developmental stage, starvation, dietary alterations, and fluctuations in ambient temperature. Highest activity is observed during the middle of the penultimate instar and 3 to 6 days after adult emergence. Starvation markedly decreases Delta(12) activity, whereas resumption of feeding on fat-free or low fat diets increases activity.

  12. "Naturalization" of Routine Assisted Reproductive Technologies by In Vitro Culture of Embryos with Microvibration: Sex Ratio, Body Length, and Weight of 2,456 Live-Birth Deliveries after Transfer of 9,624 Embryos In Vitro Cultured in Static System and with Microvibration.

    Science.gov (United States)

    Isachenko, Vladimir; Sterzik, Karl; Isachenko, Evgenia; Maettner, Robert; Todorov, Plamen; Rahimi, Gohar; Mallmann, Peter; Strehler, Erwin; Pereligin, Igor; Alabart, José Luis; Merzenich, Markus

    2017-01-01

    Aim was to determine whether there is any difference in the sex ratio, body length, and body weight of 2,456 deliveries after transfer of 9,624 embryos derived using in vitro culture under static and mechanical microvibration conditions. Pronuclear embryos from 4435 patients were cultured in vitro under two different conditions: without ( n = 4821) and with mechanical agitation ( n = 4803). Sex ratio, body length, and weight of 2,456 live-birth deliveries after transfer of 9,624 embryos were noted. The proportion of males at birth was significantly associated with mode of in vitro culture of embryos only among women aged 40 years and older. The rate "body length" was significantly associated with mode of in vitro culture of embryos only among women aged 29 and younger. In the same time, among twins, this ratio positively associated with in vitro culture of embryos under microvibration only among women aged 30-34 years as well as ≥40 years and negatively among women aged 35-39 years. It was concluded that birth weight of infants was positively associated with mode of in vitro culture of embryos under microvibration among women of all age groups. This trial registration number is ISRCTN13773904, registered 6 April 2016.

  13. Effect of Aging Time and Temperature on Microstructure and Mechanical Properties of Ti-39Nb-6Zr Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyun Jun; Lim, Ka Ram; Lee, Yong Tae; Kim, Seung Eon [Korea Institute of Materials Science, Changwon (Korea, Republic of); Lee, Dong Geun [Sunchon National University, Sunchon (Korea, Republic of); Lee, Jun Hee [Dong-A University, Busan (Korea, Republic of)

    2016-12-15

    The aim of this study is to optimize the microstructure and mechanical properties of Ti-39Nb-6Zr (TNZ40) for bio-implant applications. TNZ40 was designed to have a low elastic modulus (⁓40GPa) and good biocompatibility. However, the alloy shows relatively low strength compared to other titanium alloys for bio-implant. In the present study, we tried to obtain the proper combination of elastic modulus and strength by tailoring the direct aging conditions after severe plastic deformation. The mechanical properties are closely linked to characteristics including the distribution and volume fraction of precipitates.

  14. Low-temperature synthesis of CuFeO{sub 2} (delafossite) at 70 °C: A new process solely by precipitation and ageing

    Energy Technology Data Exchange (ETDEWEB)

    John, Melanie, E-mail: melanie.john@min.uni-muenchen.de [Section Mineralogy, Petrology & Geochemistry, Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Theresienstr. 41, 80333 Munich (Germany); Heuss-Aßbichler, Soraya [Section Mineralogy, Petrology & Geochemistry, Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Theresienstr. 41, 80333 Munich (Germany); Park, So-Hyun [Section Crystallography, Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Theresienstr. 41, 80333 Munich (Germany); Ullrich, Aladin [Experimental Physics II, University of Augsburg, Universitätsstr. 1, 86159 Augsburg (Germany); Benka, Georg [Physics Department, Technical University Munich, James-Franck-Straße 1, 85748 Garching (Germany); Petersen, Nikolai [Section Geophysics, Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Theresienstr. 41, 80333 Munich (Germany); Rettenwander, Daniel [Department of Materials Research & Physics, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg (Austria); Horn, Siegfried R. [Experimental Physics II, University of Augsburg, Universitätsstr. 1, 86159 Augsburg (Germany)

    2016-01-15

    This study presents a new low temperature synthesis method to obtain pure delafossite (Cu{sup 1+}Fe{sup 3+}O{sub 2}) at a temperature of 70 °C within 24 h. For the first time delafossite is synthesized solely by precipitation and subsequent ageing process and without usage of any additives controlling the oxidation state of copper. The synthesized material, called LT-delafossite, consists of pure Cu{sup 1+}Fe{sup 3+}O{sub 2} exclusive of any side products. Rietveld analysis confirms the presence of both 3R (space group (SG): R-3m) and 2H (SG: P6{sub 3}/mmc) polytypes in LT-delafossite. Electron microscopy images show nanometer-sized hexagonal plates with a diameter <500 nm and a thickness of <30 nm. Measurements of the magnetic susceptibility from 2 K to 350 K in zero-field show one peak ∼18.5 K, which is attributed to an AFM phase transition. Zero-field-cooled magnetization data between −14 T and +14 T at 2 K revealed an s-shape form around the origin having no remanent magnetization. - Highlights: • New process: low temperature synthesis of pure CuFeO{sub 2} nanoparticles. • Synthesis at 70 °C within 24 h solely by precipitation and ageing. • Nanoparticle characterization by XRD, FTIR, SEM, ICP–OES, TEM and Mößbauer. • Special magnetic properties of nano-sized CuFeO{sub 2} synthesized at low temperatures.

  15. Somatic Embryos in Catharanthus roseus: A Scanning Electron Microscopic Study

    Directory of Open Access Journals (Sweden)

    Junaid ASLAM

    2014-06-01

    Full Text Available Catharanthus roseus (L. G. Don is an important medicinal plant as it contains several anti-cancerous compounds, like vinblastine and vincristine. Plant tissue culture technology (organogenesis and embryogenesis has currently been used in fast mass propagating raw materials for secondary metabolite synthesis. In this present communication, scanning electron microscopic (SEM study of somatic embryos was conducted and discussed. The embryogenic callus was first induced from hypocotyls of in vitro germinated seeds on which somatic embryos, differentiated in numbers, particularly on 2,4-D (1.0 mg/L Murashige and Skoog (MS was medium. To understand more about the regeneration method and in vitro formed embryos SEM was performed. The SEM study revealed normal somatic embryo origin and development from globular to heart-, torpedo- and then into cotyledonary-stage of embryos. At early stage, the embryos were clustered together in a callus mass and could not easily be detached from the parental tissue. The embryos were often long cylindrical structure with or without typical notch at the tip. Secondary embryos were also formed on primary embryo structure. The advanced cotyledonary embryos showed prominent roots and shoot axis, which germinated into plantlets. The morphology, structure and other details of somatic embryos at various stages were presented.

  16. Tissue densities in developing avian embryos. [under acceleration stresses

    Science.gov (United States)

    Smith, A. H.; Abbott, U. K.; Morzenti, A.

    1984-01-01

    The density changes in the components of the incubated egg, the embryo, and the embryo's body parts were measured in the course of 21 days of incubation. In the first two-thirds of the incubation period there is a sequence of increasing density among egg contents: amniotic fluid, embryo, yolk, and albumin. As a result, the embryo is located at the bottom of the amniotic fluid, but at the top of the albumin. This position provides the embryo with mechanical protection and a proximity to the egg's air cell. The observed density changes and the asymmetry of these changes among various body parts of the embryo suggest a functional relationship. The density distributions among the body parts are particularly important in gravitational investigations of embryogenesis since they will produce forces tending to dislocate parts of the embryo.

  17. Nucleolar changes in bovine nucleotransferred embryos.

    Science.gov (United States)

    Baran, V; Vignon, X; LeBourhis, D; Renard, J P; Fléchon, J E

    2002-02-01

    This study focused on nucleolar changes in bovine embryos reconstructed from enucleated mature oocytes fused with blastomeres of morulae or with cultured, serum unstarved bovine fetal skin fibroblasts (embryonic vs. somatic cloning). The nucleotransferred (NT) embryos were collected and fixed at time intervals of 1-2 h (early 1-cell stage), 10-15 h (late 1-cell stage), 22-24 h (2-cell stage), 37-38 h (4-cell stage), 40-41 h (early 8-cell stage), 47-48 h (late 8-cell stage), and 55 h (16-cell stage) after fusion. Immunocytochemistry by light and electron microscopy was used for structure-function characterization of nucleolar components. Antibodies against RNA, protein B23, protein C23, and fibrillarin were applied. In addition, DNA was localized by the terminal deoxynucleotidyl transferase (TdT) technique, and the functional organization of chromatin was determined with the nick-translation immunogold approach. The results show that fully reticulated (active) nucleoli observed in donor cells immediately before fusion as well as in the early 1-cell stage after fusion were progressively transformed into nucleolar bodies displaying decreasing numbers of vacuoles from the 2- to 4-cell stage in both types of reconstructed embryos. At the late 8-cell stage, morphological signs of resuming nucleolar activity were detected. Numerous new small vacuoles appeared, and chromatin blocks reassociated with the nucleolar body. During this period, nick-translation technique revealed numerous active DNA sites in the periphery of chromatin blocks associated with the nucleolar body. Fully reticulated nucleoli were again observed as early as the 16-cell stage of embryonic cloned embryos. In comparison, the embryos obtained by fetal cloning displayed a lower tendency to develop, mainly during the first cell cycle and during the period of presumed reactivation. Correlatively, the changes in nucleolar morphology (desegregation and rebuilding) were at least delayed in many somatic NT

  18. A direct temperature-resolved tandem mass spectrometry study of cholesterol oxidation products in light-aged egg tempera paints with examples from works of art

    Science.gov (United States)

    van den Brink, Oscar F.; Ferreira, Ester S. B.; van der Horst, Jerre; Boon, Jaap J.

    2009-07-01

    Cholesterol (1) constitutes approximately 5% of the lipid fraction of eggs. The compound is therefore abundant in fresh egg tempera paints. The fate of cholesterol upon light ageing of egg tempera paint binding medium was investigated by direct temperature resolved mass spectrometry (DTMS) and tandem mass spectrometry (DTMSMS). Cholesterol oxidation products (COPs) such as 5,6-epoxycholestan-3-ol (2) and 3-hydroxycholest-5-en-7-one (3) were positively identified in light-aged egg binding medium. Given the fast rate of oxidation of cholesterol, the corresponding oxidation products are better markers for egg tempera than the cholesterol molecule itself. Cholesterol and COPs were discovered in paints on German baroque altar pieces from the 16th and 18th C and in a 20th C glaze on a Mark Rothko Seagram Mural painting at Tate by DTMS fingerprinting analysis of paint microsamples.

  19. Vitrification of early-stage bovine and equine embryos.

    Science.gov (United States)

    Campos-Chillòn, L F; Suh, T K; Barcelo-Fimbres, M; Seidel, G E; Carnevale, E M

    2009-01-15

    The objectives of this study were to: (1) determine an optimal method and stage of development for vitrification of bovine zygotes or early embryos; and (2) use the optimal procedure for bovine embryos to establish equine pregnancies after vitrification and warming of early embryos. Initially, bovine embryos produced by in-vitro fertilization (IVF) were frozen and vitrified in 0.25mL straws with minimal success. A subsequent experiment was done using two vitrification methods and super open pulled straws (OPS) with 1- or 8-cell bovine embryos. In Method 1 (EG-O), embryos were exposed to 1.5M ethylene glycol (EG) for 5min, 7M ethylene glycol and 0.6M galactose for 30s, loaded in an OPS, and plunged into liquid nitrogen. In Method 2 (EG-DMSO), embryos were exposed to 1.1M ethylene glycol and 1.1M dimethyl sulfoxide (DMSO) for 3min, 2.5M ethylene glycol, 2.5M DMSO and 0.5M galactose for 30s, and loaded and plunged as for EG-O. Cryoprotectants were removed after warming in three steps. One- and eight-cell bovine embryos were cultured for 7 and 4.5 d, respectively, after warming, and control embryos were cultured without vitrification. Cleavage rates of 1-cell embryos were similar (P>0.05) for vitrified and control embryos, although the blastocyst rates for EG-O and control embryos were similar and higher (Pvitrification and warming. In summary, a successful method was established for vitrification of early-stage bovine embryos, and this method was used to establish equine pregnancies after vitrification and warming of 2- to 8-cell embryos produced by ICSI.

  20. The effects of thermal manipulations during embryogenesis of broiler chicks on growth of embryo and skeletal traits

    Energy Technology Data Exchange (ETDEWEB)

    Aygün, Ali, E-mail: aaygun@selcuk.edu.tr [Selcuk University, Faculty of Agriculture, Department of Animal Science, Konya, 42075 (Turkey); Narinç, Doğan, E-mail: narincd@gmail.com [Namik Kemal University, Faculty of Veterinary Medicine, Department of Genetics, Tekirdag, 59100 (Turkey)

    2016-04-18

    Incubation temperature is one of the important environmental factors that can induce epigenetic thermal adaptation of different physiological control systems. Thus, post hatch thermo tolerance ability of birds may be gained using these manipulations during different incubation periods. The current study was carried out to reveal the effects of temperature manipulations during early and late embryogenesis on weight of embryo and size of skeletal bilateral traits (face, wings, metatarsus, tibia, and femur) in broiler chicken embryos. One thousand commercial broiler eggs from 46 week old breeder flock were used in study. Treatments consisted of eggs incubated at 37.8°C and 55% relative humidity throughout (control; DG1), heated to 36.9°C and supplied 60% relative humidity for 6 hours daily from day 0 to 8 (DG2), heated to 36.9°C and supplied 60% relative humidity for 6 hours daily from day 10 to 18 (DG3), heated to 41°C and supplied 65% relative humidity for 3 hours daily from day 8 to 10 (DG4), and heated to 41°C and supplied 65% relative humidity for 3 hours daily from day 16 to 18 (DG5). Measurements of embryo weight and bilateral traits were obtained at 20 day of incubation and at hatch (at day 21). It was determined that the live weights of embryo and chick were affected significantly by treatment; DG3 group has shown higher mean values than the other treatment groups (P<0.05). There were differences in lengths of femur, tibia and metatarsus among treatment groups at hatch. Particularly, the high incubator temperatures at the second half of incubation accelerated growth of body and bone in embryos. These consequences of the treatments performed at different temperatures and times indicate that the different metabolic shifts realized by the embryos.

  1. Late-onset temperature reduction can retard the aging process in aged fish via a combined action of an anti-oxidant system and the insulin/insulin-like growth factor 1 signaling pathway.

    Science.gov (United States)

    Wang, Xia; Chang, Qingyun; Wang, Yu; Su, Feng; Zhang, Shicui

    2014-12-01

    Two different mechanisms are considered to be related to aging. Cumulative molecular damage caused by reactive oxygen species (ROS), the by-products of oxidative phosphorylation, is one of these mechanisms (ROS concept). Deregulated nutrient sensing by the insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) pathway is the second mechanism (IIS concept). Temperature reduction (TR) is known to modulate aging and prolong life span in a variety of organisms, but the mechanisms remain poorly defined. Here we first demonstrate that late-onset TR from 26 °C to 22 °C extends mean life span and maximum life span by approximately 5.2 and 3 weeks, respectively, in the annual fish Nothobranchius guentheri. We then show that TR is able to decrease the accumulation of the histological aging markers senescence-associated β-galactosidase (SA-β-Gal) in the epithelium and lipofuscin (LF) in the liver and to reduce protein oxidation and lipid peroxidation levels in the muscle. We also show that TR can enhance the activities of catalase, glutathione peroxidase, and superoxide dismutase, and stimulate the synthesis of SirT1 and FOXO3A/FOXO1A, both of which are the downstream regulators of the IIS pathway. Taken together, our findings suggest that late-onset TR, a simple non-intrusion intervention, can retard the aging process in aged fish, resulting in their life span extension, via a synergistic action of an anti-oxidant system and the IIS pathway. This also suggests that combined assessment of the ROS and IIS concepts will contribute to providing a more comprehensive view of the anti-aging process.

  2. Inducing triploids and tetraploids with high temperatures in Populus sect. Tacamahaca.

    Science.gov (United States)

    Guo, Liqin; Xu, Wenting; Zhang, Yan; Zhang, Jinfeng; Wei, Zunzheng

    2017-02-01

    This study is the first to report that triploids and tetraploids have been successfully produced through embryo sac and zygotic embryo chromosome doubling with high temperatures in P. simonii Carr. and its hybrid. A new synthetic polyploid induced by hybridization with unreduced gametes and heterozygotic embryo chromosome doubling can effectively combine polyploidy and heterosis, which can provide two major breeding advantages. In Populus, successfully creating and cultivating new polyploid varieties have economic and ecological production value. This was the first successful study in which embryo sac and zygotic embryo chromosome doubling was induced using high temperatures to produce triploids and tetraploids in Populus simonii Carr. and its hybrid, P. simonii × P. nigra var. Italica, of Populus sect. Tacamahaca. The relationship between flower bud morphological characteristics (time after pollination) and female meiotic stage (embryo sac and zygotic embryo development) was established to guide the induction treatment period. In the resulting progeny, 37 triploids and 12 tetraploids were obtained and identified using flow cytometry. The optimal temperatures for embryo sac and zygotic embryo chromosome doubling were 38 and 41 °C, respectively. Cytogenetic analysis revealed that 66-72 h after pollination (HAP), a period characterized by a high proportion of one-nucleate and two-nucleate embryo sacs, was the optimal period for embryo sac chromosome doubling. For zygotic embryo chromosome doubling, 168 HAP was the optimal induction period, as there was a high proportion of two-cell and four-cell proembryos. The results indicate that inducing embryo sac and zygotic embryo chromosome doubling is an ideal method for producing polyploids. The methods for inducing polyploids and for evaluating ploidy and offspring with different ploidies and heterozygosity in this study will be useful for genetic research and Populus breeding programmes.

  3. Selecting embryos with the highest implantation potential using data mining and decision tree based on classical embryo morphology and morphokinetics.

    Science.gov (United States)

    Carrasco, Beatriz; Arroyo, Gemma; Gil, Yolanda; Gómez, Mª José; Rodríguez, Ignacio; Barri, Pedro N; Veiga, Anna; Boada, Montserrat

    2017-08-01

    The objective of this work was to determine which embryonic morphokinetic parameters up to D3 of in vitro development have predictive value for implantation for the selection of embryos for transfer in clinical practice based upon information generated from embryo transfers with known implantation data (KID). A total of 800 KID embryos (100% implantation rate (IR) per transfer and 0% IR per transfer) cultured in an incubator with Time-Lapse system were retrospectively analysed. Of them, 140 embryos implanted, whereas 660 did not. The analysis of morphokinetic parameters, together with the embryo morphology assessment on D3, enabled us to develop a hierarchical model that places the classical morphological score, the t4 and t8 morphokinetic values, as the variables with the best prognosis of implantation. In our decision tree, the classical morphological score is the most predictive parameter. Among embryos with better morphological scores, morphokinetics permits deselection of embryos with the lowest implantation potential.

  4. Echinoderm eggs and embryos: procurement and culture.

    Science.gov (United States)

    Foltz, Kathy R; Adams, Nikki L; Runft, Linda L

    2004-01-01

    The protocols outlined here hopefully will provide researchers with healthy, beautiful echinoderm oocytes, eggs, and embryos for experimental use. The large size of echinoderm oocytes and eggs, the ease with which they can be manipulated, and (in many species) their optical clarity, make them an ideal model system for studying not only the events specific to oocyte maturation and fertilization, but also for investigating more general questions regarding cell cycle regulation in an in vivo system. The quick rate at which development proceeds after fertilization to produce transparent embryos and larva makes the echinoderm an advantageous organism for studying deuterostome embryogenesis. Continued use of the echinoderms as model systems will undoubtedly uncover exciting answers to questions regarding fertilization, cell cycle regulation, morphogenesis, and how developmental events are controlled.

  5. New device for the vitrification and in-straw warming of in vitro produced bovine embryos.

    Science.gov (United States)

    Morató, Roser; Mogas, Teresa

    2014-04-01

    Two experiments were designed to test the use of a new device designed to vitrify and in-straw warm in vitro produced (IVP) embryos, which can potentially be used for their direct transfer to recipient females in field conditions. In experiment 1, IVP embryos from both prepubertal and adult animals were vitrified on cryotops and warmed in steps (1, 0.5 and 0M sucrose; protocol W3) or directly in 0.5M (protocol W1/0.5) or 0M sucrose (protocol W1/0). Similar survival rates were recorded 24h after warming for calf embryos irrespective of the warming procedure (W3: 79.2%, W1/0.5: 62.5%, W1/0: 66.7%). For cow embryos, survival rates at 24h post-warming were significantly higher when embryos were warmed using the W3 (85.7%) or W1/0.5 (89.1%) protocols compared to the W1/0 protocol (70.5%). In experiment 2, IVP embryos were vitrified on the new designed device followed by their in-straw cryoprotectant (0.5M sucrose) dilution/warming and different warming temperatures (45, 50, 60 and 70°C) were tested. When warming solution passed through the new vitrification/warming device at 45°C, 61.5% of blastocysts were fully re-expanded or hatched at 24h post-warming, being not significantly different to the control (65%). Other warming temperatures triggered significantly lower survival rates at 24h post-warming. No significant differences were detected in total cell numbers and blastocyst apoptosis indices in response to vitrification followed by warming at 45°C respect to the control. Our findings indicate that the new device allows vitrification and in-straw warming of IVP bovine embryos, being a useful option for their direct transfer in field conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Further Development and Validation of the Frog Embryo Teratogenesis Assay-Xenopus (FETAX).

    Science.gov (United States)

    1992-11-23

    high osmosis water to culture the adults with no temperature bake oven in which glassware can be apparent adverse effects on results. Only non- heated...Toxicol 14(1&2):143-160, 199 1. Laevis. Bull Environ Contain Toxicol 22:159-166, 1979. Friedman M, Rayburn JR, Bantle JA: Developmental toxicology of potato ...160. Friedman, M., Rayburn, J.R., and Bantle, J.A. 1990. Developmental toxicology of potato alkaloids in the Frog Embryo Teratogenesis Assay-Xenopus

  7. Neurogenesis in zebrafish - from embryo to adult

    OpenAIRE

    Schmidt, R; Strähle, U; Scholpp, S.

    2013-01-01

    Neurogenesis in the developing central nervous system consists of the induction and proliferation of neural progenitor cells and their subsequent differentiation into mature neurons. External as well as internal cues orchestrate neurogenesis in a precise temporal and spatial way. In the last 20 years, the zebrafish has proven to be an excellent model organism to study neurogenesis in the embryo. Recently, this vertebrate has also become a model for the investigation of adult neurogenesis and ...

  8. Human embryo cloning prohibited in Hong Kong.

    Science.gov (United States)

    Liu, Athena

    2005-12-01

    Since the birth of Dolly (the cloned sheep) in 1997, debates have arisen on the ethical and legal questions of cloning-for-biomedical-research (more commonly termed "therapeutic cloning") and of reproductive cloning using human gametes. Hong Kong enacted the Human Reproductive Technology Ordinance (Cap 561) in 2000. Section 15(1)(e) of this Ordinance prohibits the "replacing of the nucleus of a cell of an embryo with a nucleus taken from any other cell," i.e., nucleus substitution. Section 15(1)(f) prohibits the cloning of any embryo. The scope of the latter, therefore, is arguably the widest, prohibiting all cloning techniques such as cell nucleus replacement, embryo splitting, parthenogenesis, and cloning using stem cell lines. Although the Human Reproductive Technology Ordinance is not yet fully operative, this article examines how these prohibitions may adversely impact on basic research and the vision of the Hong Kong scientific community. It concludes that in light of recent scientific developments, it is time to review if the law offers a coherent set of policies in this area.

  9. Genetic analysis of embryo dormancy. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Galau, G.

    1998-09-01

    Primary dormancy is the inability of mature seed to immediately germinate until specific environmental stimuli are perceived that predict that future conditions will support plant growth and seed set. The analysis of abscisic acid deficient and insensitive mutants, in particular in Arabidopsis, suggests that embryo abscisic acid may be directly involved in the development of primary dormancy. Other studies implicate the continued accumulation of LEA proteins as inhibiting germination in dormant embryos. The results of these physiological, molecular and genetic approaches are complex and equivocal. There is a real need for approaches that test the separate nature of vivipary inhibition and primary dormancy and deliberately seed to decouple and dissect them. These approaches should be of help in understanding both late embryo development and primary dormancy. The approach taken here is to directly isolate mutants of Arabidopsis that appear to be deficient only in primary dormancy, that is fresh seed that germinate rapidly without the normally-required cold-stratification. The authors have isolated at least 8 independent, rapidly germinating RGM mutants of Arabidopsis. All others aspects of plant growth and development appear normal in these lines, suggesting that the rgm mutants are defective only in the establishment or maintenance of primary dormancy. At least one of these may be tagged with T-DNA. In addition, about 50 RGM isolates have been recovered from EMS-treated seed.

  10. Characterization of embryo-specific genes

    Energy Technology Data Exchange (ETDEWEB)

    Sung, R.

    1992-06-12

    The objective of the proposed research is to characterize the function and regulation of a set of embryonic genes which are expressed in the embryos, not in the plants. 22 cDNA clones were isolated from a cDNA library we constructed using mRNAS of -carrot somatic embryos. These cDNA clones identified mRNA species that are present in the somatic and zygotic embryos, but not in adult plants. The sequence of all 22cDNA clones were determined; genomic clones for three cDNA clones, DC8, DC59, and DC49 were isolated and gene sequences determined. DC8, DC49, and several other genes identified by the cDNA sequences belong to the category of late embryogenesis abundant protein genes, Lea. The function of these gens have not yet been determined, but they share common structural features, are regulated by ABA and are speculated to play a role in seed desiccation.

  11. Addition of ascorbate during cryopreservation stimulates subsequent embryo development.

    Science.gov (United States)

    Lane, Michelle; Maybach, Jeffery M; Gardner, David K

    2002-10-01

    Embryo development following cryopreservation is reduced compared with fresh embryos. One of the traumas that cryopreservation imparts on embryos is an increase in oxidative stress. Therefore, this study investigated the effects of the addition of the antioxidant ascorbate to the cryopreservation solutions on subsequent embryo development. Mouse embryos at the 2-cell and blastocyst stages were either slow-frozen or vitrified in solutions containing either no ascorbate or 0.1 or 0.5 mmol/l ascorbate. The effects on the levels of hydrogen peroxide and subsequent embryo development and physiology were assessed. Addition of ascorbate to the cryopreservation solutions reduced the levels of hydrogen peroxide in embryos. Furthermore, addition of 0.1 mmol/l ascorbate significantly enhanced inner cell mass development in blastocysts. Embryos cryopreserved with ascorbate had significantly lower levels of lactate dehydrogenase leakage, and increased rates of metabolism compared with those cryopreserved in the absence of ascorbate. The benefits of ascorbate were significantly greater in embryos that were slow-frozen compared with those that were vitrified. These data indicate that the addition of 0.1 mmol/l ascorbate to the cryopreservation solutions for the mammalian embryo would be of significant value.

  12. Cryopreservation of embryos of Lucilia sericata (Diptera: Calliphoridae).

    Science.gov (United States)

    Rajamohan, Arun; Rinehart, Joseph P; Leopold, Roger A

    2014-03-01

    Embryos of Lucilia (Phaenicia) sericata (Meigen) (Diptera Calliphoridae), the green blowfly, were successfully cryopreserved by vitrification in liquid nitrogen and stored for 8 yr. Embryos incubated at 19 degrees C for 17 h after oviposition were found to be the most appropriate stage to cryopreserve. Removal of the embryonic surface water was done using 2-propanol before the alkane treatment to permeabilize the embryo. Exposure to 2-propanol for > 10 s caused necrotic tissue damage in the embryos. Among the alkanes used, hexane was found to be a superior permeabilizing solvent compared with heptane or octane, with embryo hatching rates on par with the controls. Treatment with the vitrification solution for < 12 min was insufficient to vitrify the embryos. Treatment time in the solution beyond 15 min reduced embryo viability. However, the percentage of embryos vitrifying upon exposure to liquid nitrogen vapor remained constant after 12 min of treatment. Long-term storage was initiated in 2004, and the mean hatch percentage recorded then for the short-term cryopreserved embryos was 9.51%. When the long-term stored samples were retrieved in 2012, 8.47% of the embryos hatched, 66.36% larvae pupariated, and 36.96% of the pupae eclosed. Recent optimization of the technique has resulted in a hatch rate of 34.08 +/- 15.5%, of which 67.5% of the larvae pupariated and 72% of the pupae eclosed to normal flies.

  13. Germination ecology of the endemic Iberian daffodil Narcissus radinganorum (Amaryllidaceae. Dormancy induction by cold stratification or desiccation in late stages of embryo growth

    Directory of Open Access Journals (Sweden)

    José María Herranz

    2015-04-01

    Full Text Available Aim of study: We studied the germination ecology of a threatened daffodil in order to develop a protocol to produce plants ex-situ from seeds, a key tool for population reinforcement. Area of study: Experiments were carried out both outdoors and in the laboratory in Albacete (Spain. Material and methods: Embryo length, radicle and shoot emergence were analyzed to determine the level of morphophysiological dormancy (MPD. Effects on germination of cold stratification or desiccation in late stages of embryo growth were also studied. Main results: Mean embryo length in fresh seeds was 1.36 mm, needing to grow up to 2.20 mm to be able to germinate. In the laboratory, embryo growth occurred during warm stratification (28/14, 25/10 ºC, and then radicle emerged when temperatures went down (15/4 ºC in darkness. Phenology study in outdoors conditions revealed that embryo grew during summer-early autumn, short time after seed dispersal in nature (i.e., May; radicle emerged in autumn. The shoot however did not emerge until late winter-early spring, because it was physiologically dormant and required a cold (5 ºC period of 30 days to break dormancy. Early cold temperatures interrupted the embryo growth and induced dormancy in seeds whose embryo had grown 30% with respect to the initial length. Desiccation in seeds whose embryo had grown 30% did not induce dormancy, but did it when the embryo growth reached 70%. Research highlights: Seeds of Narcissus radinganorum have deep simple epicotyl MPD.

  14. Effect of heat stress on development in vitro and in vivo and on synthesis of heat shock proteins in porcine embryos.

    Science.gov (United States)

    Kojima, T; Udagawa, K; Onishi, A; Iwahashi, H; Komatsu, Y

    1996-04-01

    The present study was conducted (1) to examine the effect of an acute increase in ambient temperature on the development of porcine day 6 embryos in culture and after transfer to recipient gilts, and (2) to analyze intracellular production of heat shock proteins (hsps). The viability of porcine day 6 embryos following a temporary acute elevation in ambient temperature (at 42 degrees-45.5 degrees C and for 10-180 min) was examined. Synthesis of 70 kDa hsp (hsp70) and 90 kDa hsp (hsp90) was determined by SDS-PAGE and Western blot analysis in porcine day 6 embryos subjected to heat stresses. Nonheat-stressed embryos were considered as control. Significantly higher numbers of viable nuclei were observed in treatment groups of 42 degrees C-10 min (236.6 +/- 71.4; P heat stress compared to control (82.5 +/- 47.3 microns), while heat stress with 43 degrees C for > or = 60 min, 44 degrees-44.5 degrees C for > or = 30 min, or 45 degrees-45.5 degrees C for > or = 10 min impaired their survival, as assessed by differences in number of viable nuclei. The embryos subjected to heat stresses under the conditions of 42 degrees C-180 min, 43 degrees C-10 min, 43 degrees C-30 min, 44 degrees C-10 min, or 45 degrees C-10 min developed to normal piglets after transfer to recipient gilts. Overall pregnancy rate was 75% (6/8), and farrowing rate 62.5% (5/8). Of heat-stressed embryos transferred, 59% (36/61) developed to normal piglets. Heat-stress conditions of 42 degrees C for 180 min, 43 degrees C for 30 min, 44 degrees C for 10 min, and 45 degrees C for 10 min were determined as critical with respect to the in vitro and in vivo survival of porcine embryos. Porcine day 6 embryos constitutively synthesized hsp70 even without heat stress, while hsp90 was detected only at trace level. Neither hsp70 nor hsp90 levels increased in the embryos subjected to heat stresses. In conclusion, porcine day 6 embryos could continue to develop in vivo or during in vitro culture after exposure to acute

  15. Propylthiouracil is teratogenic in murine embryos.

    Directory of Open Access Journals (Sweden)

    Valeria C Benavides

    Full Text Available BACKGROUND: Hyperthyroidism during pregnancy is treated with the antithyroid drugs (ATD propylthiouracil (PTU and methimazole (MMI. PTU currently is recommended as the drug of choice during early pregnancy. Yet, despite widespread ATD use in pregnancy, formal studies of ATD teratogenic effects have not been performed. METHODS: We examined the teratogenic effects of PTU and MMI during embryogenesis in mice. To span different periods of embryogenesis, dams were treated with compounds or vehicle daily from embryonic day (E 7.5 to 9.5 or from E3.5 to E7.5. Embryos were examined for gross malformations at E10.5 or E18.5 followed by histological and micro-CT analysis. Influences of PTU on gene expression levels were examined by RNA microarray analysis. RESULTS: When dams were treated from E7.5 to E9.5 with PTU, neural tube and cardiac abnormalities were observed at E10.5. Cranial neural tube defects were significantly more common among the PTU-exposed embryos than those exposed to MMI or vehicle. Blood in the pericardial sac, which is a feature indicative of abnormal cardiac function and/or abnormal vasculature, was observed more frequently in PTU-treated than MMI-treated or vehicle-treated embryos. Following PTU treatment, a total of 134 differentially expressed genes were identified. Disrupted genetic pathways were those associated with cytoskeleton remodeling and keratin filaments. At E 18.5, no gross malformations were evident in either ATD group, but the number of viable PTU embryos per dam at E18.5 was significantly lower from those at E10.5, indicating loss of malformed embryos. These data show that PTU exposure during embryogenesis is associated with delayed neural tube closure and cardiac abnormalities. In contrast, we did not observe structural or cardiac defects associated with MMI exposure except at the higher dose. We find that PTU exposure during embryogenesis is associated with fetal loss. These observations suggest that PTU has

  16. Gender, Age and Season as Modifiers of the Effects of Diurnal Temperature Range on Emergency Room Admissions for Cause-Specific Cardiovascular Disease among the Elderly in Beijing

    Directory of Open Access Journals (Sweden)

    Shan Zheng

    2016-04-01

    Full Text Available Background: Diurnal temperature range (DTR is an important index of climate change and variability. It is also a risk factor affecting human health. However, limited evidence is available to illustrate the effect of DTR modification on cause-specific cardiovascular disease among the elderly. Methods: A semi-parametric generalized additive model (GAM was used to analyze the exposure-effect relationship between DTR and daily emergency room (ER admissions for cause-specific cardiovascular diseases among the elderly from 2009 to 2011 in Beijing. We examined the effects of DTR for stratified groups by gender and age, and examined the effects of DTR in the warm season and cold season for cause-specific cardiovascular diseases. Results: Significant associations were found between DTR and ER admissions for all cardiovascular and cerebrovascular disease among elderly males, while DTR was significantly associated with ER admissions for all cardiovascular disease, ischemic heart disease and cerebrovascular disease among elderly females. People aged 75 years and older were more vulnerable to DTR. DTR caused greater adverse effects on both genders in the warm season, whereas the effect estimates on females were higher in cold season than in warm season. Conclusions: A short-term increase of DTR was significantly associated with ER admissions for cause-specific cardiovascular disease among the elderly in Beijing. Gender, age and season may modify the acute health effect of DTR. Some prevention programs that target the high risk subgroups in the elderly for impending large temperature changes may reduce the impact of DTR on people’s health.

  17. The Embryo Project: an integrated approach to history, practices, and social contexts of embryo research.

    Science.gov (United States)

    Maienschein, Jane; Laubichler, Manfred D

    2010-01-01

    This essay describes the approach and early results of the collaborative Embryo Project and its on-line encyclopedia (http://embryo.asu.edu). The project is based on a relational database that allows federated searches and inclusion of multiple types of objects targeted for multiple user groups. The emphasis is on the history and varied contexts of developmental biology, focusing on people, places, institutions, techniques, literature, images, and other aspects of study of embryos. This essay introduces the ways of working as well as the long-term goals of the project. We invite others to join the effort, both in this particular project and in joining together in digital collection, archiving, and knowledge generation at the borders of biology and history.

  18. Embryo quality and impact of specific embryo characteristics on ongoing implantation in unselected embryos derived from modified natural cycle in vitro fertilization

    NARCIS (Netherlands)

    Pelinck, Marie-Jose; Hoek, Annemieke; Simons, Arnold H. M.; Heineman, Maas Jan; van Echten-Arends, Janny; Arts, Eus G. J. M.

    Objective: To study the implantation potential of unselected embryos derived from modified natural cycle IVF according to their morphological characteristics. Design: Cohort study. Setting: Academic department of reproductive medicine. Patient(S): A series of 449 single embryo transfers derived from

  19. Interactions of acid-base balance and hematocrit regulation during environmental respiratory gas challenges in developing chicken embryos (Gallus gallus).

    Science.gov (United States)

    Burggren, Warren W; Andrewartha, Sarah J; Tazawa, Hiroshi

    2012-08-15

    How the determinants of hematocrit (Hct) - alterations in mean corpuscular volume (MCV) and/or red blood cell concentration ([RBC]) - are influenced by acid-base balance adjustments across development in the chicken embryo is poorly understood. We hypothesized, based on oxygen transport needs of the embryos, that Hct will increase during 1 day of hypercapnic hypoxia (5%CO(2), 15%O(2)) or hypoxia alone (0%CO(2), 15%O(2)), but decrease in response to hyperoxia (0%CO(2), 40%O(2)). Further, age-related differences in acid-base disturbances and Hct regulation may arise, because the O(2) transport and hematological regulatory systems are still developing in embryonic chickens. Our studies showed that during 1 day of hypoxia (with or without hypercapnia) Hct increased through both increased MCV and [RBC] in day 15 (d15) embryo, but only through increased MCV in d17 embryo and therefore enhancement of O(2) transport was age-dependent. Hypercapnia alone caused a ≈ 14% decrease in Hct through decreased [RBC] and therefore did not compensate for decreased blood oxygen affinity resulting from the Bohr shift. The 11% (d15) and 14% (d17) decrease in Hct during hyperoxia in advanced embryos was because of an 8% and 9% decrease, respectively, in [RBC], coupled with an associated 3% and 5% decrease in MCV. Younger, d13 embryos were able to metabolically compensate for respiratory acidosis induced by hypercapnic hypoxia, and so were more tolerant of disturbances in acid-base status induced via alterations in environmental respiratory gas composition than their more advanced counterparts. This counter-intuitive increased tolerance likely results from the relatively low [Formula: see text] and immature physiological functions of younger embryos. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Comparison between Conventional Blind Embryo Transfer and Embryo Transfer Based on Previously Measured Uterine Length

    Directory of Open Access Journals (Sweden)

    Nasrin Saharkhiz

    2014-11-01

    Full Text Available Background: Embryo transfer (ET is one of the most important steps in assisted reproductive technology (ART cycles and affected by many factors namely the depth of embryo deposition in uterus. In this study, the outcomes of intracytoplasmic sperm injection (ICSI cycles after blind embryo transfer and embryo transfer based on previously measured uterine length using vaginal ultrasound were compared. Materials and Methods: This prospective randomised clinical trial included one hundred and forty non-donor fresh embryo transfers during January 2010 to June 2011. In group I, ET was performed using conventional (blind method at 5-6cm from the external os, and in group II, ET was done at a depth of 1-1.5 cm from the uterine fundus based on previously measured uterine length using vaginal sonography. Appropriate statistical analysis was performed using Student’s t test and Chi-square or Fisher’s exact test. The software that we used was PASW statistics version 18. A p value <0.05 was considered statistically significant. Results: Chemical pregnancy rate was 28.7% in group I and 42.1% in group II, while the difference was not statistically significant (p=0.105. Clinical pregnancy, ongoing pregnancy and implantation rates for group I were 21.2%, 17.7%, and 12.8%, while for group II were 33.9%, 33.9%, and 22.1, respectively. In group I and group II, abortion rates were 34.7% and 0%, respectively, indicating a statistically significant difference (p<0.005. No ectopic pregnancy occurred in two groups. Conclusion: The use of uterine length measurement during treatment cycle in order to place embryos at depth of 1-1.5cm from fundus significantly increases clinical and ongoing pregnancy and implantation rates, while leads to a decrease in abortion rate (Registration Number: IRCT2014032512494N1.

  1. Effects of embryo-derived exosomes on the development of bovine cloned embryos.

    Science.gov (United States)

    Qu, Pengxiang; Qing, Suzhu; Liu, Ruiqi; Qin, Hongyu; Wang, Weiwei; Qiao, Fang; Ge, Hui; Liu, Jun; Zhang, Yong; Cui, Wei; Wang, Yongsheng

    2017-01-01

    The developmental competence of in vitro cultured (IVC) embryos is markedly lower than that of their in vivo counterparts, suggesting the need for optimization of IVC protocols. Embryo culture medium is routinely replaced three days after initial culture in bovine, however, whether this protocol is superior to continuous nonrenewal culture method under current conditions remains unclear. Using bovine somatic cell nuclear transfer (SCNT) embryos as the model, our results showed that compared with routine renewal treatment, nonrenewal culture system significantly improved blastocyst formation, blastocyst quality (increased total cell number, decreased stress and apoptosis, enhanced Oct-4 expression and ratio of ICM/TE), as well as following development to term. Existence and function of SCNT embryo-derived exosomes were then investigated to reveal the cause of impaired development induced by culture medium replacement. Exosomes were successfully isolated through differential centrifugation and identified by both electron microscopy and immunostaining against exosomal membrane marker CD9. Supplementation of extracted exosomes into freshly renewed medium significantly rescued not only blastocyst formation and quality (in vitro development), but also following growth to term (in vivo development). Notably, ratio of ICM/TE and calving rate were enhanced to a similar level as that in nonrenewal group. In conclusion, our results for the first time indicate that 1: bovine SCNT embryos can secrete exosomes into chemically defined culture medium during IVC; 2: secreted exosomes are essential for SCNT blastocyst formation, blastocyst quality, and following development to term; 3: removal of exosomes induced by culture medium replacement impairs SCNT embryo development, which can be avoided by nonrenewal culture procedure or markedly recovered by exosome supplementation.

  2. Low-temperature thermal evolution of the Azov Massif (Ukrainian Shield Ukraine) — Implications for interpreting (U Th)/He and fission track ages from cratons

    Science.gov (United States)

    Danišík, Martin; Sachsenhofer, Reinhard F.; Privalov, Vitaliy A.; Panova, Elena A.; Frisch, Wolfgang; Spiegel, Cornelia

    2008-08-01

    The low-temperature thermal evolution of the Azov Massif (eastern part of the Ukrainian Shield, Ukraine) is investigated by combined zircon fission track (ZFT), apatite fission track (AFT) and apatite (U-Th)/He (AHe) thermochronology. The data help to better understand the geodynamic evolution of the Azov Massif and the adjacent intra-cratonic rift basin (Dniepr-Donets Basin) as follows: ZFT data reveal that the Precambrian crystalline basement of the Azov Massif was heated to temperatures close to ˜ 240 °C during the Late Palaeozoic. The heating event is interpreted in terms of burial of the basement beneath a several kilometres thick pile of Devonian and Carboniferous sedimentary deposits of the adjacent Dniepr-Donets Basin. During Permo-Triassic times, large parts of the basement were affected by a thermal event related to mantle upwelling, associated magmatic activity and increased heat flow in the adjacent rift. The major part of the basement cooled to near-surface conditions in the Early to Middle Triassic and since then was thermally stable as suggested by AFT and AHe data. Further, AFT data confirm Late Triassic magmatic activity in the Azov Massif, which, however, did not influence regional thermal pattern. The northern part of the basement and its sedimentary cover record a cooling event in the Jurassic, which was probably related to erosion. However, although Ar-Ar data of Jurassic magmatic activity in the Donbas Foldbelt are about 20 My younger than the AFT data, thermal relaxation after elevated heat flow associated with this magmatic event cannot be completely ruled out. Our results reveal apparent inconsistencies between AFT and AHe data: the AHe ages corrected for alpha ejection according to the standard procedure [Farley, K.A., Wolf, R.A., Silver, L.T., 1996. The effect of long alpha-stopping distances on (U-Th)/He ages. Geochim. Cosmochim. Acta 60(21), 4223-4229.; Farley, K.A., 2002. (U-Th)/He dating: Techniques, calibrations, and applications

  3. Objective Assessments of Temperature Maintenance Using In Vitro Culture Techniques

    OpenAIRE

    Cooke, Simon; Tyler, John P. P.; Driscoll, Geoff

    2002-01-01

    Purpose: To assess the ability of various facets of embryo culture (microscope stage warmers, volumes of culture media, culture vessel lids, and type of culture incubator) to maintain a constant temperature in vitro.

  4. In vitro culture of individual mouse preimplantation embryos: the role of embryo density, microwells, oxygen, timing and conditioned media.

    Science.gov (United States)

    Kelley, Rebecca L; Gardner, David K

    2017-05-01

    Single embryo culture is suboptimal compared with group culture, but necessary for embryo monitoring, and culture systems should be improved for single embryos. Pronucleate mouse embryos were used to assess the effect of culture conditions on single embryo development. Single culture either before or after compaction reduced cell numbers (112.2 ± 3.1; 110.2 ± 3.5) compared with group culture throughout (127.0 ± 3.4; P media volume from 20 µl to 2 µl increased blastocyst cell numbers in single embryos cultured in 5% oxygen (84.4 ± 3.2 versus 97.8 ± 2.8; P Culture in microwell plates for the EmbryoScope and Primo Vision time-lapse systems changed cleavage timings and increased inner cell mass cell number (24.1 ± 1.0; 23.4 ± 1.2) compared with a 2 µl microdrop (18.4 ± 1.0; P media to single embryos increased hatching rate and blastocyst cell number (91.5 ± 4.7 versus 113.1 ± 4.4; P culture before or after compaction is therefore detrimental; oxygen, media volume and microwells influence single embryo development; and embryo-conditioned media may substitute for group culture. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  5. Fabrication of Transparent Conductive Zinc Oxide Co-Doped with Fluorine and Zirconium Thin Solid Films by Ultrasonic Chemical Pyrolysis: Effects of Precursor Solution Aging and Substrate Temperature

    Directory of Open Access Journals (Sweden)

    Luis Castañeda

    2013-01-01

    Full Text Available Highly transparent, conducting zinc oxide [ZnO] thin films co-doped with fluorine and zirconium have been deposited on glass substrates by the ultrasonic chemical spraying technique. The effects of aging of the starting solution and substrate temperature on the structural, morphological, and electrical properties of the ZnO:F:Zr films have been studied. The resistivity of the films decreases with the aging time of the starting solution until the seventeenth day reaching a minimum of about 1.2×10−2 Ω cm and then increases. Though all the samples are of polycrystalline hexagonal wurtzite type and grow preferentially with (002 plane parallel to the substrate, their morphology depends strongly on the aging time of the reaction solution. The optical transmittance of all the films remained around 80% in the visible spectral range. These highly transparent, low resistive thin films are expected to be highly useful as transparent electrodes in the fabrication of thin film solar cells.

  6. When no choice of embryos exists, the multiple pregnancy risk is still high.

    LENUS (Irish Health Repository)

    Wong, V V

    2012-10-01

    Multiple pregnancies arising from assisted reproduction are known to be associated with increased medical, psychological, economical and social risks. If only two embryos develop after culture, how should the couple be counselled in relation to the risk of multiple pregnancy? We performed a retrospective review of all IVF\\/ICSI treatments performed between 1 January 2005 and 31 December 2007, that resulted in double embryos transfer (DET). We identified 623 cycles with a fortuitous DET (Group I) and 635 cycles with an elective DET (Group II). Group II were significantly more likely to have twins when compared with Group I, irrespective of age. Twin rates in Group I were higher in IVF compared with ICSI; 33.3% vs 16.6% in < 35 years old and 16.2% vs 7.6% in 35-40 years old. Therefore, single embryo transfer should be considered for IVF patients below 35 years old, even if only two good quality embryos are available.

  7. [Effects of basic orange II on proliferation and differentiation of limb bud cells in rat embryos].

    Science.gov (United States)

    Zheng, Lixin; Feng, Jiawang; Tian, Shimin

    2015-01-01

    To explore the effects of basic orange II on proliferation and differentiation of limb bud cells. Limb bud cell were separated from SD rat embryo at 13-day gestational age, limb bud cell were exposed to basic orange II at concentrations of 0.0, 12.5, 25.0, 50.0, 100.0, 200, 0 and 400.0 mg/L in the culture medium. The effect of basic orange II on limb bud cell proliferation was detected by Cell Counting Kit-8, the effect of basic orange II on limb bud cell differentiation was assessed by Alcian Blue 8GX. With the increasing of basic orange II concentration, the proliferation and differentiation of embryo limb bud cells were poorer and poorer in vitro, and there was the dose-effect relationship. The pID50 and dLD50 of basic orange II on limb bud cells were 240.6 mg/L and 69.3 mg/L respectively. The inhibition of basic orange II on cell differentiation might exceed that on cell proliferation. Basic orange II could inhibit proliferation and differentiation of embryo limb bud cells. It might be a potential developmental toxic substance in rat embryo.

  8. Genetic comparison of water molds from embryos of amphibians Rana cascadae, Bufo boreas and Pseudacris regilla.

    Science.gov (United States)

    Ault, Kori K; Johnson, James E; Pinkart, Holly C; Wagner, R Steven

    2012-06-13

    Water molds that cause the disease saprolegniasis have been implicated in widespread mortality of amphibian embryos. However, because of the limitations of traditional identification methods, water mold species involved in die-offs or utilized in ecological studies often remain unidentified or identified only as Saprolegnia ferax. Furthermore, water mold taxonomy requires revision, so very distinct organisms may all be called S. ferax. Recent DNA-based studies indicate that the diversity of water molds infecting amphibian embryos is significantly higher than what was previously known, but these studies rely on culture methods, which may be biased towards taxa that grow best under laboratory conditions. In this study, total embryo-associated DNA was extracted from 3 amphibian species in a pond in central Washington, USA. The internal transcribed spacer (ITS) region of DNA was amplified with primers capable of amplifying a broad array of eukaryotic microorgansisms, and was used to construct clone libraries. Individual clones were sequenced and relationships among newly recovered sequences and previously studied taxa were analyzed using phylogenetics. These methods recovered several new taxa in association with amphibian embryos. Samples grouped into 11 distinct phylotypes with ITS sequence differences ranging from 4 to 28%. The water mold communities recovered differed among Rana cascadae, Bufo boreas, and Pseudacris regilla egg masses. Furthermore, the diversity of water molds increased as egg masses aged, and members comprising this diversity changed over time.

  9. Re-Thinking Elective Single Embryo Transfer: Increased Risk of Monochorionic Twinning - A Systematic Review.

    Science.gov (United States)

    Dziadosz, Margaret; Evans, Mark I

    2017-01-01

    Multiple pregnancies have tripled in the United States over the past 3 decades. Attributed to increasing maternal age at delivery but more so assisted reproductive technological advances, an effort has been made to decrease twinning through elective single embryo transfer. We sought to review and evaluate risks of monochorionic twinning as a predictable consequence of increasing utilization of elective single embryo transfer on perinatal outcomes. Primary outcomes included twinning rates, fetal anomalies, growth, preterm birth, and mortality. Secondary outcomes included neurological and pulmonary disability, intrauterine growth restriction, and congenital cardiac anomalies and twin-twin transfusion syndrome. PubMed and Embase. A total of 106 studies identified by systematic search met the inclusion criteria. The trend for lower numbers of embryos transferred has inadvertently led to an increase in monochorionic twinning. This is associated with worse outcomes compared to dichorionic twinning and singleton gestations for all outcomes studied. Of great concern for monochorionic twins is the risk profile of significant morbidity and mortality. Transfer of 2 embryos should be considered to avoid higher risks inherent to the shared placental phenomena related to monochorionic twins. © 2017 S. Karger AG, Basel.

  10. The Effect of Prolonged Culture of Chromosomally Abnormal Human Embryos on The Rate of Diploid Cells

    Directory of Open Access Journals (Sweden)

    Masood Bazrgar

    2016-12-01

    Full Text Available Background: A decrease in aneuploidy rate following a prolonged co-culture of human blastocysts has been reported. As co-culture is not routinely used in assisted reproductive technology, the present study aimed to evaluate the effect of the prolonged single culture on the rate of diploid cells in human embryos with aneuploidies. Materials and Methods: In this cohort study, we used fluorescence in situ hybridization (FISH to reanalyze surplus blastocysts undergoing preimplantation genetic diagnosis (PGD on day 3 postfertilization. They were randomly studied on days 6 or 7 following fertilization. Results: Of the 30 analyzed blastocysts, mosaicism was observed in 26(86.6%, while 2(6.7% were diploid, and 2(6.7% were triploid. Of those with mosaicism, 23(88.5% were determined to be diploid-aneuploid and 3(11.5% were aneuploid mosaic. The total frequency of embryos with more than 50% diploid cells was 33.3% that was lower on day 7 in comparison with the related value on day 6 (P<0.05; however, there were no differences when the embryos were classified according to maternal age, blastocyst developmental stage, total cell number on day 3, and embryo quality. Conclusion: Although mosaicism is frequently observed in blastocysts, the prolonged single culture of blastocysts does not seem to increase the rate of normal cells.

  11. Exposure to high ambient temperatures alters embryology in rabbits

    Science.gov (United States)

    García, M. L.; Argente, M. J.

    2017-09-01

    High ambient temperatures are a determining factor in the deterioration of embryo quality and survival in mammals. The aim of this study was to evaluate the effect of heat stress on embryo development, embryonic size and size of the embryonic coats in rabbits. A total of 310 embryos from 33 females in thermal comfort zone and 264 embryos of 28 females in heat stress conditions were used in the experiment. The traits studied were ovulation rate, percentage of total embryos, percentage of normal embryos, embryo area, zona pellucida thickness and mucin coat thickness. Traits were measured at 24 and 48 h post-coitum (hpc); mucin coat thickness was only measured at 48 hpc. The embryos were classified as zygotes or two-cell embryos at 24 hpc, and 16-cells or early morulae at 48 hpc. The ovulation rate was one oocyte lower in heat stress conditions than in thermal comfort. Percentage of normal embryos was lower in heat stress conditions at 24 hpc (17.2%) and 48 hpc (13.2%). No differences in percentage of zygotes or two-cell embryos were found at 24 hpc. The embryo development and area was affected by heat stress at 48 hpc (10% higher percentage of 16-cells and 883 μm2 smaller, respectively). Zona pellucida was thicker under thermal stress at 24 hpc (1.2 μm) and 48 hpc (1.5 μm). No differences in mucin coat thickness were found. In conclusion, heat stress appears to alter embryology in rabbits.

  12. Vibrational properties characterization of mouse embryo during microinjection

    Directory of Open Access Journals (Sweden)

    Hedrih Anđelka N.

    2013-01-01

    Full Text Available To determine the vibration characteristics (natural frequencies and mode shapes of a mouse embryo during microinjection the modal analysis is used. The spherical mouse embryo 60 μm in diameter is modeled as elastic finite elements biostructure consisting of 6μm thick micromembrane and 38 μm in diameter nucleus. Embryo modeling and modal analysis were based on the use of the finite elements method in the modal analysis system of ANSYS software. The modal analysis was carried out for first six modes of embryo natural frequencies. The numerical analysis of dependence of embryo own frequencies on the boundary conditions and external loads are presented. The relevant illustrations of the typical variations of the shape, deformation and particle velocities of vibrating embryo are given. [Projekat Ministarstva nauke Republike Srbije, br. OI174001: Dynamics of hybrid systems with complex structures: Mechanics of materials

  13. Cutin fluorescence in early embryos of Pinus and Tsuga

    Directory of Open Access Journals (Sweden)

    Ewa Szczuka

    2014-01-01

    Full Text Available Embryos of Pinus nigra Arnold and Tsuga canadensis Carr. (Pinaceae at different stages of development were dissected from fresh, unfixed seeds and examined in a fluorescence microscope with 400 nm excitation light. The embryos of the investigated species showed cutin fluorescence after auramine 0 staining. At first the fluorescing cutin layer was formed on the apical part of the embryo with a well developed secondary suspensor, then it extended over the lateral surface of the embryo; the suspensor remained nonfluorescent. The fluorescing cutin layer occurred on the apical and side surface of the embryo, undergoing differentiation into the shoot axis and root initials. It is assumed that polarization and nutrition of the embryo may be influenced by presence of the cuticle.

  14. Globulin gene expression in embryos of maize viviparous mutants

    Energy Technology Data Exchange (ETDEWEB)

    Kriz, A.R.; Wallace, M.S.; Paiva, R. (Univ. of Illinois, Urbana (USA))

    1990-02-01

    Expression of genes encoding the major Zea mays embryo globulins was examined in the maize precocious germination viviparous (vp) mutants. Comparison of globulin protein profiles of precociously germinating mutant embryos with those of normally germinating mature embryos revealed substantial differences with respect to the proteins encoded by the Glb1 gene. Analysis of Glb1 transcript levels in vp/vp embryos suggests that these mutants do not fully switch from a program of embryo maturation to one of germination. These preliminary studies indicate that the vp mutants provide an excellent system for the study of embryo maturation in maize. We also provide evidence for the positive regulation of Glb1 expression by the plant growth regulator abscisic acid.

  15. Embryo sac development in some South African Lantana species (Verbenaceae

    Directory of Open Access Journals (Sweden)

    J. J. Spies

    1984-12-01

    Full Text Available Evidence that the South African Lantana camara L. complex only produces sexual embryo sacs is provided. It is shown that the archesporium occasionally divides mitotically and that both archesporia form tetrads. The chalazal megaspore of one tetrad and the micropylar megaspore of the second tetrad develop into Polygonum type embryo sacs. L. rugosa Thunb. also forms Polygonum type embryo sacs. The L. rugosa embryo sac has a much more densely packed cytoplasm, smaller vacuole and the position of the polar nuclei differs from that of the L. camara embryo sac. It is possible to distinguish between  L. camara and  L. rugosa on their embryo sac morphology alone.

  16. Effect of embryo freezing on perinatal outcome after assisted reproduction techniques: lessons from the Latin American Registry of Assisted Reproduction.

    Science.gov (United States)

    Schwarze, Juan-Enrique; Crosby, Javier A; Zegers-Hochschild, Fernando

    2015-07-01

    Embryo cryopreservation is an integral part of assisted reproduction techniques; it allows the sequential transfer of all embryos, thus diminishing the risk of multiple pregnancies and associated perinatal complications. To address concerns about the safety of this procedure, neonatal outcome after 43,070 fresh embryo transfers was compared with 12,068 frozen-thawed embryo transfers (FET). After adjusting for maternal age, gestational age, embryo development at time of transfer, number of babies born and gestational order, FET was not found to be associated with an increase in perinatal mortality (odds ratio [OR] 1.72, 95% confidence interval [CI] 0.81 to 3.62); preterm birth (OR 1.05, 95% CI 0.93 to 1.18); or extreme preterm birth (OR 0.82, 95% CI 0.64 to 1.06). Furthermore, after correcting for known confounding factors, FET was found to be associated with an increase in neonatal weight of 39.7 g (95% CI 1.54 to 64.10; P Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  17. Available phosphorus levels in diets supplemented with phytase for male broilers aged 22 to 42 days kept in a high-temperature environment

    Directory of Open Access Journals (Sweden)

    Tarciso Tizziani

    2016-02-01

    Full Text Available ABSTRACT This study was conducted to evaluate the effect of reduction of the available phosphorus (avP in diets supplemented with 500 FTU/kg phytase on performance, carcass characteristics, and bone mineralization of broilers aged 22 to 42 days kept in a high-temperature environment. A total of 336 Cobb broilers with an average initial weight of 0.883±0.005 kg were distributed in a completely randomized design with six treatments - a positive control (0.354 and 0.309% avP without addition of bacterial phytase for the phases of 22 to 33 and 34 to 42 days, respectively, and another five diets with inclusion of phytase (500 FTU and reduction of the level of avP (0.354, 0.294, 0.233, 0.173, and 0.112%; and 0.309, 0.258, 0.207, 0.156, and 0.106% for the phases of 22 to 33 and 34 to 42 days, respectively - eight replicates, and seven birds per cage. The experimental diets were formulated to meet all nutritional requirements, except for avP and calcium. Birds were kept in climatic chambers at a temperature of 32.2±0.4 °C and air humidity of 65.3±5.9%. Phytase acted by making the phytate P available in diets with reduction in the levels of avP, keeping feed intake, weight gain, feed:gain, and carcass characteristics unchanged. Treatments affected ash and calcium deposition and the Ca:P ratio in the bone; the group fed the diets with 0.112 and 0.106%, from 22 to 33 and 34 to 42 days of age, respectively, obtained the lowest values, although the phosphorus deposition in the bone was not affected. Diets supplemented with 500 FTU of phytase, with available phosphorus reduced to 0.173 and 0.156%, and a fixed Ca:avP ratio of 2.1:1, meet the requirements of broilers aged 22 to 33 and 34 to 42 days, respectively, reared in a high-temperature environment.

  18. Effects of vitrification medium composition on the survival of bovine in vitro produced embryos, following in straw-dilution, in vitro and in vivo following transfer.

    Science.gov (United States)

    Pugh, P A; Tervit, H R; Niemann, H

    2000-02-28

    This study examined the effects of adding a macromolecule, polyvinylpyrrolidone (10% PVP) and a sugar (0.3 M trehalose) to vitrification solutions (VS) containing either one (40% ethylene glycol [EG], two (25% EG+25% DMSO) or three (20% EG+20% DMSO+10% 1, 3-butanediol [BD]) permeable cryoprotectants on the survival and hatching of IVP bovine embryos, following vitrification, warming and in-straw cryoprotectant dilution. Grade 1 and 2 compact morulae and blastocysts were selected on Day 7 (Day 0=IVF) of culture in SOFaaBSA and equilibrated for 10 min at room temperature in 10% EG. Following exposure, for up to 1 min at 4 degrees C, to one of the above VS (with or without PVP+trehalose), the embryos were loaded into straws and immersed in liquid nitrogen. Following warming and in-straw cryoprotectant dilution, the embryos were cultured for 48 h to assess hatching. There was no effect of VS on the survival of embryos after 24 h, however fewer compact morulae than blastocysts survived after 24 h (24% vs. 75%; Pvitrification (fresh vs. vitrified; 1/5 [20%] vs. 3/18 [17]). These data demonstrate that a VS comprising three cryoprotectants, rather than one, enables more embryos to hatch during post-thaw culture and that the survival, following direct transfer of these vitrified embryos, is not different to non-vitrified embryos.

  19. Embryonic control of heart rate: examining developmental patterns and temperature and oxygenation influences using embryonic avian models.

    Science.gov (United States)

    Andrewartha, Sarah J; Tazawa, Hiroshi; Burggren, Warren W

    2011-08-31

    Long-term measurements (days and weeks) of heart rate (HR) have elucidated infradian rhythms in chicken embryos and circadian rhythms in chicken hatchlings. However, such rhythms are lacking in emu embryos and only rarely observed in emu hatchlings. Parasympathetic control of HR (instantaneous heart rate (IHR) decelerations) occurs at ∼60% of incubation in both precocial and altricial avian embryos, with sympathetic control (IHR accelerations) becoming more prevalent close to hatching. A large increase in avian embryonic HR occurs during hatching (presumably an energetically expensive process, i.e. increased oxygen consumption M(O) ₂), beginning during pipping when a physical barrier to O(2) conductance is removed. Alterations in ambient O(2) have little effect on early embryonic HR, likely due to the low rate of M(O)₂ of early embryos and the fact that adequate O(2) delivery can occur via diffusion. As M(O)₂ increases in advanced embryos and circulatory convection becomes important for O(2) delivery, alterations in ambient O(2) have more profound effects on embryonic HR. Early embryos demonstrate a wide ambient temperature (T(a)) tolerance range compared with older embryos. In response to a rapid decrease in T(a), embryonic HR decreases (stroke volume and blood flow are preserved) in an exponential fashion to a steady state (from which it can potentially recover if re-warmed). A more severe decrease in T(a) results in complete cessation of HR; however, depending on developmental age, embryos are able to survive severe cold exposure and cessation of HR for up to 24h in some instances. The development of endothermy can be tracked by measuring baseline HR during T(a) changes. HR patterns change from thermo-conformity to thermoregulation (reverse to T(a) changes). Further, IHR low frequency oscillations mediated by the autonomic nervous system are augmented at low T(a)s in hatchlings. Transitions of baseline HR during endothermic development are unique to

  20. In vitro production of horse embryos: fundamental aspects

    OpenAIRE

    López Tremoleda, Jordi

    2003-01-01

    Developments in assisted reproduction have provided valuable tools for sub-fertility treatment and for selective breeding in animals. In horses, techniques such as artificial insemination and embryo transfer are used successfully to aid genetic progress but the commercial application of other assisted reproductive techniques, such as in vitro production of embryos (IVP), has been severely restricted by their low efficiency. The development of culture systems that can support embryo developmen...

  1. Ultra-Structural Alterations in In Vitro Produced Four-Cell Bovine Embryos Following Controlled Slow Freezing or Vitrification.

    Science.gov (United States)

    Cavusoglu, T; Popken, J; Guengoer, T; Yilmaz, O; Uyanikgil, Y; Ates, U; Baka, M; Oztas, E; Zakhartchenko, V

    2016-08-01

    Cryopreservation is the process of freezing and preserving cells and tissues at low temperatures. Controlled slow freezing and vitrification have successfully been used for cryopreservation of mammalian embryos. We investigated the effect of these two cryopreservation methods on in vitro produced four-cell stage bovine embryos which were classified according to their quality and separated into three groups. The first group was maintained as untreated controls (n = 350). Embryos of the second (n = 385) and the third (n = 385) groups were cryopreserved either by controlled slow freezing or by vitrification. Embryos in groups 2 and 3 were thawed after 1 day. Hundred embryos were randomly selected from the control group, and 100 morphologically intact embryos from the second and third group were thawed after 1 day and cultured to observe the development up to the blastocyst stage. The blastocyst development rate was 22% in the control group, 1% in the slow-freezing group and 3% in the vitrification group. Remaining embryos of all three groups were examined by light microscopy, transmission electron microscopy and immunofluorescence confocal microscopy with subsequent histological staining procedures. Cryopreservation caused degenerative changes at the ultra-structural level. Compared with vitrification, slow freezing caused an increased mitochondrial degeneration, cytoplasmic vacuolization, disruption of the nuclear and plasma membrane integrity, organelle disintegration, cytoskeletal damage, a reduced thickness of the zona pellucida and a formation of fractures in the zona pellucida. Further studies are required to understand and decrease the harmful effects of cryopreservation. © 2015 Blackwell Verlag GmbH.

  2. Dynamic analysis of angiogenesis in transgenic zebrafish embryos using a 3D multilayer chip-based technology

    Science.gov (United States)

    Akagi, Jin; Zhu, Feng; Hall, Chris J.; Khoshmanesh, Khashayar; Kalantar-Zadeh, Kourosh; Mitchell, Arnan; Crosier, Kathryn E.; Crosier, Philip S.; Wlodkowic, Donald

    2013-03-01

    Transgenic zebrafish (Danio rerio) models of human diseases have recently emerged as innovative experimental systems in drug discovery and molecular pathology. None of the currently available technologies, however, allow for automated immobilization and treatment of large numbers of spatially encoded transgenic embryos during real-time developmental analysis. This work describes the proof-of-concept design and validation of an integrated 3D microfluidic chip-based system fabricated directly in the poly(methyl methacrylate) transparent thermoplastic using infrared laser micromachining. At its core, the device utilizes an array of 3D micro-mechanical traps to actively capture and immobilize single embryos using a low-pressure suction. It also features built-in piezoelectric microdiaphragm pumps, embryo trapping suction manifold, drug delivery manifold and optically transparent indium tin oxide (ITO) heating element to provide optimal temperature during embryo development. Furthermore, we present design of the proof-of-concept off-chip electronic interface equipped with robotic servo actuator driven stage, innovative servomotor-actuated pinch valves and miniaturized fluorescent USB microscope. Our results show that the innovative device has 100% embryo trapping efficiency while supporting normal embryo development for up to 72 hours in a confined microfluidic environment. We also present data that this microfluidic system can be readily applied to kinetic analysis of a panel of investigational anti-angiogenic agents in transgenic zebrafish Tg(fli1a:EGFP) line. The optical transparency and embryo immobilization allow for convenient visualization of developing vasculature patterns in response to drug treatment without the need for specimen re-positioning. The integrated electronic interfaces bring the Lab-on-a-Chip systems a step closer to realization of complete analytical automation.

  3. Genetic variation in resistance of the preimplantation bovine embryo to heat shock.

    Science.gov (United States)

    Hansen, Peter J

    2014-12-01

    Reproduction is among the physiological functions in mammals most susceptible to disruption by hyperthermia. Many of the effects of heat stress on function of the oocyte and embryo involve direct effects of elevated temperature (i.e. heat shock) on cellular function. Mammals limit the effects of heat shock by tightly regulating body temperature. This ability is genetically controlled: lines of domestic animals have been developed with superior ability to regulate body temperature during heat stress. Through experimentation in cattle, it is also evident that there is genetic variation in the resistance of cells to the deleterious effects of elevated temperature. Several breeds that were developed in hot climates, including Bos indicus (Brahman, Gir, Nelore and Sahiwal) and Bos taurus (Romosinuano and Senepol) are more resistant to the effects of elevated temperature on cellular function than breeds that evolved in cooler climates (Angus, Holstein and Jersey). Genetic differences are expressed in the preimplantation embryo by Day 4-5 of development (after embryonic genome activation). It is not clear whether genetic differences are expressed in cells in which transcription is repressed (oocytes >100 µm in diameter or embryos at stages before embryonic genome activation). The molecular basis for cellular thermotolerance has also not been established, although there is some suggestion for involvement of heat shock protein 90 and the insulin-like growth factor 1 system. Given the availability of genomic tools for genetic selection, identification of genes controlling cellular resistance to elevated temperature could be followed by progress in selection for those genes within the populations in which they exist. It could also be possible to introduce genes from thermotolerant breeds into thermally sensitive breeds. The ability to edit the genome makes it possible to design new genes that confer protection of cells from stresses like heat shock.

  4. Improved cryopreservation of in vitro-produced bovine embryos using a chemically defined freezing medium.

    Science.gov (United States)

    Bruyère, P; Baudot, A; Guyader-Joly, C; Guérin, P; Louis, G; Buff, S

    2012-10-01

    This study evaluates a new synthetic substitute (CRYO3, Ref. 5617, Stem Alpha, France) for animal-based products in bovine embryo cryopreservation solutions. During the experiment, fetal calf serum (FCS) and bovine serum albumin (BSA) were used as references. A combination of a thermodynamic approach using differential scanning calorimetry and a biological approach using in vitro-produced bovine embryo slow-freezing was used to characterize cryopreservation solutions containing CRYO3, FCS and BSA. The CRYO3 and fetal calf serum (FCS) slow-freezing solutions were made from Dulbecco's phosphate-buffered saline containing 1.5 m ethylene glycol, 0.1 m sucrose and 20% (v.v(-1)) of CRYO3 or FCS. The bovine serum albumin (BSA) solution was made by adding 0.1 m sucrose to a commercial solution containing 1.5 m ethylene glycol and 4 g L(-1) BSA. These solutions were evaluated using three characteristics: the end of melting temperature, the enthalpy of crystallization (thermodynamic approach) and the embryo survival and hatching rates after in vitro culture (biological approach). The CRYO3 and FCS solutions had similar thermodynamic properties. In contrast, the thermodynamic characteristics of the BSA solution were different from those of the FCS and CRYO3 solutions. Nevertheless, the embryo survival and hatching rates obtained with the BSA and FCS solutions were not different. Similar biological properties can thus be obtained with slow freezing solutions that have different physical properties within a defined range. The embryo survival rate after 48 h of in vitro culture obtained with the CRYO3 solution (81.5%) was higher than that obtained with the BSA (42.2%, P = 0.000 12) and FCS solutions (58%, P = 0.016). Similarly, the embryo hatching rate after 72 h of in vitro culture was higher with the CRYO3 solution (61.1%) than with the BSA (31.1%, P = 0.0055) and FCS solutions (36%, P = 0.018). We conclude that CRYO3 can be used as a chemically defined substitute for animal

  5. Air bubble migration is a random event post embryo transfer.

    Science.gov (United States)

    Confino, E; Zhang, J; Risquez, F

    2007-06-01

    Air bubble location following embryo transfer (ET) is the presumable placement spot of embryos. The purpose of this study was to document endometrial air bubble position and migration following embryo transfer. Multicenter prospective case study. Eighty-eight embryo transfers were performed under abdominal ultrasound guidance in two countries by two authors. A single or double air bubble was loaded with the embryos using a soft, coaxial, end opened catheters. The embryos were slowly injected 10-20 mm from the fundus. Air bubble position was recorded immediately, 30 minutes later and when the patient stood up. Bubble marker location analysis revealed a random distribution without visible gravity effect when the patients stood up. The bubble markers demonstrated splitting, moving in all directions and dispersion. Air bubbles move and split frequently post ET with the patient in the horizontal position, suggestive of active uterine contractions. Bubble migration analysis supports a rather random movement of the bubbles and possibly the embryos. Standing up changed somewhat bubble configuration and distribution in the uterine cavity. Gravity related bubble motion was uncommon, suggesting that horizontal rest post ET may not be necessary. This report challenges the common belief that a very accurate ultrasound guided embryo placement is mandatory. The very random bubble movement observed in this two-center study suggests that a large "window" of embryo placement maybe present.

  6. Preimplantation death of xenomitochondrial mouse embryo harbouring bovine mitochondria

    Science.gov (United States)

    Kawahara, Manabu; Koyama, Shiori; Iimura, Satomi; Yamazaki, Wataru; Tanaka, Aiko; Kohri, Nanami; Sasaki, Keisuke; Takahashi, Masashi

    2015-01-01

    Mitochondria, cellular organelles playing essential roles in eukaryotic cell metabolism, are thought to have evolved from bacteria. The organization of mtDNA is remarkably uniform across species, reflecting its vital and conserved role in oxidative phosphorylation (OXPHOS). Our objectives were to evaluate the compatibility of xenogeneic mitochondria in the development of preimplantation embryos in mammals. Mouse embryos harbouring bovine mitochondria (mtB-M embryos) were prepared by the cell-fusion technique employing the haemagglutinating virus of Japan (HVJ). The mtB-M embryos showed developmental delay at embryonic days (E) 3.5 after insemination. Furthermore, none of the mtB-M embryos could implant into the maternal uterus after embryo transfer, whereas control mouse embryos into which mitochondria from another mouse had been transferred developed as well as did non-manipulated embryos. When we performed quantitative PCR (qPCR) of mouse and bovine ND5, we found that the mtB-M embryos contained 8.3% of bovine mitochondria at the blastocyst stage. Thus, contamination with mitochondria from another species induces embryonic lethality prior to implantation into the maternal uterus. The heteroplasmic state of these xenogeneic mitochondria could have detrimental effects on preimplantation development, leading to preservation of species-specific mitochondrial integrity in mammals. PMID:26416548

  7. Cryopreservation of somatic embryos of paradise tree (Melia azedarach L.).

    Science.gov (United States)

    Scocchi, Adriana; Vila, Silvia; Mroginski, Luis; Engelmann, Florent

    2007-01-01

    In paradise tree (Melia azedarach L.), immature zygotic embryos sampled from immature fruits are the starting material for the production of somatic embryos. These somatic embryos are employed for freezing experiments. Immature fruits could be stored at 25 degrees C for up to 80 days without impairing the embryogenic potential of zygotic embryos, which represents a four-fold increase in immature fruit storage duration, compared with previous studies. Among the three cryopreservation techniques tested for freezing paradise tree somatic embryos, namely desiccation, encapsulation-dehydration and pregrowth-dehydration, only encapsulation-dehydration and pregrowth-dehydration led to successful results. The optimal protocol was the following: i) somatic embryos (encapsulated or not) pretreated in liquid Murashige & Skoog medium with daily increasing sucrose concentration (0.5 M/0.75 M/1.0 M); ii) dehydrated with silica gel to 21 - 26% moisture content (fresh weight basis), for encapsulation-dehydration, or to 19% moisture content, for pregrowth-dehydration; iii) frozen at 1 degree C/min from 20 degrees C to -30 degrees C with a programmable freezing apparatus; iv) rapid immersion in liquid nitrogen. The highest recovery achieved was 36% with encapsulation-dehydration and 30% with pregrowth-dehydration. Regrowth of frozen embryos was direct in most cases, as secondary embryogenesis originating from the root pole was observed on only around 10% of cryopreserved somatic embryos. Plants recovered from cryopreserved embryos presented the same phenotypic traits as non-frozen control plants.

  8. In vitro production of embryos in South American camelids.

    Science.gov (United States)

    Trasorras, V; Giuliano, S; Miragaya, M

    2013-01-10

    Studies in reproductive biotechnology techniques have been minimal in South American camelids (SAC). Complex reproductive characteristics of these species contribute to slow progress. Nevertheless, some techniques, such as in vitro fertilization, intracytoplasmic sperm injection and nuclear transfer have been applied and have produced advances in knowledge on embryo environment and in vitro conditions necessary for development. Embryo production may have a high impact in both domestic and wild camelids population. Studies addressed to improve in vitro embryo production and oocyte collection could be a potential key to develop IVF and embryo production as a routine procedure in camelids. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Low-temperature synthesis of CuFeO2 (delafossite) at 70 °C: A new process solely by precipitation and ageing

    Science.gov (United States)

    John, Melanie; Heuss-Aßbichler, Soraya; Park, So-Hyun; Ullrich, Aladin; Benka, Georg; Petersen, Nikolai; Rettenwander, Daniel; Horn, Siegfried R.

    2016-01-01

    This study presents a new low temperature synthesis method to obtain pure delafossite (Cu1+Fe3+O2) at a temperature of 70 °C within 24 h. For the first time delafossite is synthesized solely by precipitation and subsequent ageing process and without usage of any additives controlling the oxidation state of copper. The synthesized material, called LT-delafossite, consists of pure Cu1+Fe3+O2 exclusive of any side products. Rietveld analysis confirms the presence of both 3R (space group (SG): R-3m) and 2H (SG: P63/mmc) polytypes in LT-delafossite. Electron microscopy images show nanometer-sized hexagonal plates with a diameter <500 nm and a thickness of <30 nm. Measurements of the magnetic susceptibility from 2 K to 350 K in zero-field show one peak ∼18.5 K, which is attributed to an AFM phase transition. Zero-field-cooled magnetization data between -14 T and +14 T at 2 K revealed an s-shape form around the origin having no remanent magnetization.

  10. Neurogenesis in zebrafish - from embryo to adult.

    Science.gov (United States)

    Schmidt, Rebecca; Strähle, Uwe; Scholpp, Steffen

    2013-02-21

    Neurogenesis in the developing central nervous system consists of the induction and proliferation of neural progenitor cells and their subsequent differentiation into mature neurons. External as well as internal cues orchestrate neurogenesis in a precise temporal and spatial way. In the last 20 years, the zebrafish has proven to be an excellent model organism to study neurogenesis in the embryo. Recently, this vertebrate has also become a model for the investigation of adult neurogenesis and neural regeneration. Here, we summarize the contributions of zebrafish in neural development and adult neurogenesis.

  11. Obtention of somatic embryos of Parajubaea cocoides Burret from immature zygotic embryos

    Directory of Open Access Journals (Sweden)

    Verónica Sánchez

    2015-01-01

    Full Text Available Cumbé coconut palm (Parajubaea cocoides Burret is an ornamental species endemic of Ecuador. It is threatened by environmental and socioeconomic factors. Your sexual propagation by seed, is not effective. Tissue culture can become an alternative and within this, somatic embryogenesis. The objective of this research was to obtain somatic embryos in semi-solid and liquid media culture from immature zygotic embryos. The explants were collected from mature plants and fruits were placed to form calli in culture medium with different concentrations of 2,4-D and activated carbon. Callus with embryogenic structures were used to form embryos in semisolid medium with BAP and kinetin and in liquid culture medium with BAP. The results showed that in treatments without activated carbon or low concentrations of 2,4-D no callus were formed. With 60 mg l-1 2,4-D and 1 g l-1 activated charcoal, friable callus were obtained. It was possible to obtain somatic embryos in semisolid and liquid culture medium, with higher number in liquid. The results provide the basis for propagating this species by somatic embryogenesis. Key words: calli, ornamental, growth regulators, palm

  12. Factors affecting survival rates of in vitro produced bovine embryos after vitrification and direct in-straw rehydration.

    Science.gov (United States)

    Vajta, G; Holm, P; Greve, T; Callesen, H

    1996-12-16

    The aim of this work was to investigate the possibilities of simplification, and to outline the limits of application, of a vitrification method for cow embryos. Morulae and blastocysts were produced by in vitro fertilization of slaughterhouse-derived, in vitro matured oocytes with frozen-thawed bull semen, and subsequent culture on a granulosa cell monolayer. Vitrification was performed by equilibration of embryos with 12.5% ethylene glycol and 12.5% dimethylsulphoxide at 20-22 degrees C for 60 s, then with 25% ethylene glycol and 25% dimethylsulphoxide at 4 degrees C for another 60 s. Embryos were then loaded in straws, placed in liquid nitrogen vapour for 2 min, and then plunged. Straws were thawed in a 22 degrees C water-bath, the embryos were directly rehydrated and further incubated in straw, and were then expelled and cultured in vitro for 72 h. In the first experiment, embryos of different age and developmental stage (Day 5 compacted morulae, Day 6 early blastocysts, Days 6 and 7 blastocysts, Day 7 expanded blastocysts and Day 8 hatched blastocysts) as well as Days 7 and 5 blastocysts previously subjected to partial zone dissection were vitrified. After thawing, the re-expansion rates of blastocysts and zona-dissected embryos did not differ (67 and 87%, respectively), and hatching was more frequent for blastocysts frozen in advanced developmental stages (34, 47 and 63% for early blastocysts, blastocysts and expanded blastocysts, respectively). The re-expansion rate of morulae was lower (10%) and no hatching of these embryos was observed. In the second experiment, Day 7 expanded blastocysts were vitrified using PBS, PBS+albumin, TCM199 and TCM199+calf serum as holding media. No differences in re-expansion and hatching rates were seen. However, when incubation with the concentrated cryoprotectant solution was performed at 20-22 degrees C, the embryo survival rate decreased (PBS+albumin) or no embryo survived (TCM199+calf serum) the vitrification procedure. In

  13. Estimation of the {beta}+ dose to the embryo resulting from {sup 18}F-FDG administration during early pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Zanotti-Fregonara, P.; Trebossen, R.; Maroy, R. [CEA, DSV, I2BM, SHFJ, LIME, Orsay (France); Champion, C. [Univ Paul Verlaine Metz, Inst Phys, Lab Phys Mol et Collis, Metz (France); Hindie, E. [Univ Paris 07, IUH, Ecole Doctorale B2T, Paris (France); Hindie, E. [Hop St Louis, AP-HP, Nucl Med Serv, F-75475 Paris 10 (France)

    2008-07-01

    Although {sup 18}F-FDG examinations are widely used, data are lacking on the dose to human embryo tissues in cases of exposure in early pregnancy. Although the photon component can easily be estimated from available data on the pharmacokinetics of {sup 18}F-FDG in female organs and from phantom measurements (considering the uterus as the target organ), the intensity of embryo tissue uptake, which is essential for deriving the {beta}+ dose, is not known. We report the case of a patient who underwent {sup 18}F-FDG PET/CT for tumor surveillance and who was later found to have been pregnant at the time of the examination(embryo age, 8 wk). Methods: The patient received 320 MBq of {sup 18}F-FDG. Imaging started with an unenhanced CT scan 1 h after the injection, followed by PET acquisition. PET images were used to compute the total number of {beta}+ emissions in embryo tissues per unit of injected activity, from standardized uptake value (SUV) measurements corrected for partial-volume effects. A Monte Carlo track structure code was then used to derive the {beta}+ self-dose and the {beta}+ cross-dose from amniotic fluid. The photon and CT doses were added to obtain the final dose received by the embryo. Results: The mean SUV in embryo tissues was 2.7, after correction for the partial-volume effect. The mean corrected SUV of amniotic fluid was 1.1. Monte Carlo simulation showed that the {beta}+ dose to the embryo (self-dose plus cross-dose from amniotic fluid) was 1.8 E-2 mGy per MBq of injected {sup 18}F-FDG. Based on MIRD data for the photon dose to the uterus, the estimated photon dose to the embryo was 1.5 E-2 mGy/MBq. Thus, the specific {sup 18}F-FDG dose to the embryo was 3.3 E-2 mGy/MBq (10.6 mGy in this patient). The CT scan added a further 8.3 mGy. Conclusion: The dose to the embryo is 3.3 E-2 mGy/MBq of {sup 18}F-FDG. The {beta}+ dose contributes 55% of the total dose. This value is higher than previous estimates in late nonhuman-primate pregnancies. (authors)

  14. Excised Embryo Rambutan (Nephelium Lappaceum L.) Dan Kepekaannya Terhadap Pengeringan*[desiccation Sensitivity of Rambutan (Nephelium Lappaceum L.) Excised Embryo

    OpenAIRE

    Soetisna, Usep; Zebua, Lisye Iriana

    2005-01-01

    A study on desiccation sensitivity of rambutan (Nephelium lappaceum L.)excised embryo has been conducted.Excised embryos were desiccated into target moisture content of 30%, 25%, 20%, 15% and 10% respectively.Results shown that the critical level for moisture content was 20% with 60% viability and 7.431% per etmal growth rate and 929ms electric conduction Further study is needed as to investigate on how long the embryo will withstand subsequent storage treatments.

  15. Long bone development in the Japanese quail (Coturnix coturnixjaponica) embryos.

    Science.gov (United States)

    Ahmed, Yasser A; Soliman, Soha A

    2013-09-15

    The current study was undertaken to describe the main histological development stages of long bones (tibia and femur) from Japanese quail (Coturnix coturnix japonica) embryos. Whole Limbs or just tibia and femur of fifty Japanese quail embryos of different ages were fixed and embedded in paraffin or Spurr's resin. Paraffin and semi-thin, respectively, were undertaken and examined with light microscopy. Limb bud was established at day 5 of incubation. Mesenchymal cells differentiated into chondrocytes forming a cartilage template in the position of the future tibia and femur at day 6 of incubation. At day 7 of incubation, the cartilage template enlarged and had the shape and position of the future tibia and femur. At day 8, central chondrocytes underwent hypertrophy and were surrounded by a periosteal bone collar. Cellular and vascular invasion from the bone collar into the central zone of the cartilage template, cartilage resorption and formation of marrow tunnel and finally peripheral calcification was seen. Vascular cartilage canals penetrating the epiphysis were observed at day 9 and the canals gradually increased in thickness and number toward the hatching day. Articular epiphyseal growth cartilage with resting, proliferative and hypertrophic zones was clearly established by day 10 of incubation. After 17 days of incubation, the zonation of the articular epiphyseal cartilage were much clear, many cartilage canals were present within the epiphyses. In epiphyses of tibia but not femur, foci of chondrocytes hypertrophy were noticed close to the cartilage canals. The current study timed the main histological sequences of development of tibia and femur of embryonic quail.

  16. AFSC/RACE/FBEP/Laurel: Role of temperature on lipid/fatty acid composition in Pacific cod (Gadus macrocephalus) eggs and unfed larvae

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is from a laboratory experiment examining whether marine fish embryos physiologically adapt to changing temperature environments.

  17. The effects of fluctuating temperature regimes on the embryonic development of lake whitefish (Coregonus clupeaformis).

    Science.gov (United States)

    Lim, Michael Y-T; Manzon, Richard G; Somers, Christopher M; Boreham, Douglas R; Wilson, Joanna Y

    2017-12-01

    Fluctuating incubation temperatures may have significant effects on fish embryogenesis; yet most laboratory-based studies use constant temperatures. For species that experience large, natural seasonal temperature changes during embryogenesis, such as lake whitefish (Coregonus clupeaformis), seasonal temperature regimes are likely optimal for development. Anthropogenic activities can increase average and/or variability of natural incubation temperatures over large (e.g. through climate change) or smaller (e.g. thermal effluent discharge) geographic scales. To investigate this, we incubated lake whitefish embryos under constant (2, 5, or 8°C) and fluctuating temperature regimes. Fluctuating temperature regimes had a base temperature of 2°C with: 1) seasonal temperature changes that modeled natural declines/inclines; 2) tri-weekly +3°C, 1h temperature spikes; or 3) both seasonal temperature changes and temperature spikes. We compared mortality to hatch, morphometrics, and heart rate at three developmental stages. Mortality rate was similar for embryos incubated at constant 2°C, constant 5°C, or with seasonal temperatures, but was significantly greater at constant 8°C. Embryos incubated constantly at >2°C had reduced body growth and yolk consumption compared to embryos incubated with seasonal temperature changes. When measured at the common base temperature of 2°C, embryos incubated at constant 2°C had lower heart rates than embryos incubated with both seasonal temperature changes and temperature spikes. Our study suggests that incubating lake whitefish embryos with constant temperatures may significantly alter development, growth, and heart rate compared to incubating with seasonal temperature changes, emphasizing the need to include seasonal temperature changes in laboratory-based studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Phytohemagglutinin facilitates the aggregation of blastomere pairs from Day 5 donor embryos with Day 4 host embryos for chimeric bovine embryo multiplication.

    Science.gov (United States)

    Simmet, Kilian; Reichenbach, Myriam; Reichenbach, Horst-Dieter; Wolf, Eckhard

    2015-12-01

    Multiplication of bovine embryos by the production of aggregation chimeras is based on the concept that few blastomeres of a donor embryo form the inner cell mass (ICM) and thus the embryo proper, whereas cells of a host embryo preferentially contribute to the trophectoderm (TE), the progenitor cells of the embryonic part of the placenta. We aggregated two fluorescent blastomeres from enhanced green fluorescent protein (eGFP) transgenic Day 5 morulae with two Day 4 embryos that did not complete their first cleavage until 27 hours after IVF and tested the effect of phytohemagglutinin-L (PHA) on chimeric embryo formation. The resulting blastocysts were characterized by differential staining of cell lineages using the TE-specific factor CDX2 and confocal laser scanning microscopy to facilitate the precise localization of eGFP-positive cells. The proportions of blastocyst development of sandwich aggregates with (n = 99) and without PHA (n = 46) were 85.9% and 54.3% (P multiplication of genetically valuable donor embryos. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Biophysical Characteristics of Successful Oilseed Embryo Cryoprotection and Cryopreservation Using Vacuum Infiltration Vitrification: An Innovation in Plant Cell Preservation

    Science.gov (United States)

    Nadarajan, Jayanthi; Pritchard, Hugh W.

    2014-01-01

    Heterogeneity in morphology, physiology and cellular chemistry of plant tissues can compromise successful cryoprotection and cryopreservation. Cryoprotection is a function of exposure time × temperature × permeability for the chosen protectant and diffusion pathway length, as determined by specimen geometry, to provide sufficient dehydration whilst avoiding excessive chemical toxicity. We have developed an innovative method of vacuum infiltration vitrification (VIV) at 381 mm (15 in) Hg (50 kPa) that ensures the rapid (5 min), uniform permeation of Plant Vitrification Solution 2 (PVS2) cryoprotectant into plant embryos and their successful cryopreservation, as judged by regrowth in vitro. This method was validated on zygotic embryos/embryonic axes of three species (Carica papaya, Passiflora edulis and Laurus nobilis) up to 1.6 mg dry mass and 5.6 mm in length, with varying physiology (desiccation tolerances) and 80°C variation in lipid thermal profiles, i.e., visco-elasticity properties, as determined by differential scanning calorimetry. Comparisons between the melting features of cryoprotected embryos and embryo regrowth indicated an optimal internal PVS2 concentration of about 60% of full strength. The physiological vigour of surviving embryos was directly related to the proportion of survivors. Compared with conventional vitrification, VIV-cryopreservation offered a ∼ 10-fold reduction in PVS2 exposure times, higher embryo viability and regrowth and greater effectiveness at two pre-treatment temperatures (0°C and 25°C). VIV-cryopreservation may form the basis of a generic, high throughput technology for the ex situ conservation of plant genetic resources, aiding food security and protection of species from diverse habitats and at risk of extinction. PMID:24788797

  20. Shifting Climate Modes and a Warm Little Ice Age: Paleo Productivity and Temperature Determinations from the Southern California Current Over the Last Millennium

    Science.gov (United States)

    Kelly, C. S.; Herbert, T.; O'Mara, N. A.; Abella-Gutiérrez, J. L.; Herguera, J. C.

    2016-12-01

    The ocean dynamical thermostat hypothesis predicts that stronger [weaker] equatorial radiation forces warmer [cooler] western Pacific sea surface temperatures (SSTs) and a cooler [warmer] Eastern Equatorial Pacific (EEP) through air-sea coupling of the Walker circulation. Although proxy data offers some support for this prediction, recent SST reconstructions from the EEP suggest complex relationships between Northern Hemisphere (NH) and EEP temperature during the last millennium (Rustic et al. 2015), with EEP SSTs positively covarying with NH temperature during the Medieval Warm Period but negatively covarying during the Little Ice Age (LIA). Whereas most proxy reconstructions have focused on the EEP upwelling zone, few high-resolution studies exist from the California Current (CC)—a region whose oceanography displays exceptional fidelity to the El Niño Southern Oscillation and the Pacific Decadal Oscillation. In particular, southern CC oceanography reflects a balance between tropically-sourced and more northerly, temperate waters. Teasing these signals apart across past centuries can provide insight as to how a more complex dynamical thermostat affects the subtropics. Does the subtropical eastern Pacific track EEP SST across multiple centuries and climatic transitions? We present a record from the San Lazaro Basin (25N, 112.5W) in the subtropical eastern Pacific off Baja, Mexico of SST and marine paleoproductivity based upon alkenone saturation and concentrations (C37tot) over the last millennium. By combining these analyses on laminated sediment cores with newly published productivity records from the same site, we provide the first sub decadal paleoceanographic record from the southern California upwelling zone. We observe quasi-periodic short-lived cold excursions, centennial modulation of multidecadal periodicities, and an inverse relationship between C37tot and SST at lower frequencies. Our SST record displays a warm Little Ice Age, similar to but 100

  1. Genetic Screening for EMS-Induced Maize Embryo-Specific Mutants Altered in Embryo Morphogenesis.

    Science.gov (United States)

    Brunelle, Dale C; Clark, Janice K; Sheridan, William F

    2017-11-06

    We have previously identified embryo-specific (emb) mutations that resulted in maize kernels containing abnormal embryos with normal-appearing endosperm among the progeny of active Robertson's Mutator stocks. Our rationale for the mutant screen described here is that it should be possible to produce ethyl methane sulfonate (EMS)-induced emb mutations at a frequency higher than that obtained by transposon mutagenesis and with greater ease. This proved to be the case when we screened for mutations that are embryo-specific among progeny of materials generated with EMS-treated pollen. The EMS-induced emb mutation frequency reported here is nearly three times the 4.5% we obtained with the transposable element stocks. The 45 mutants reported here were all tested for germination capacity and nearly all were lethal. The embryo phenotypes of 34 mutations were examined by dissection of the mature embryos. All were found to be retarded in development and morphologically abnormal. Half of the mutants in this group were blocked in the proembryo and transition stages. They likely include mutations in nuclear genes coding for plastid proteins. The other 17 are mainly blocked in the coleoptilar stage, or in later stages with a low frequency. This group likely includes mutations in genes regulating the completion of shoot apical meristem (SAM) development and accompanying morphogenetic events. Most of the complementation tests using 19 of the mutations in 35 unique combinations complimented each other, except for two pairs of mutations with similar phenotypes. Our results provide additional evidence for the presence of many emb loci in the maize genome. Copyright © 2017 Brunelle et al.

  2. Mitochondrial DNA copy number in cumulus cells is a strong predictor of obtaining good-quality embryos after IVF.

    Science.gov (United States)

    Ogino, Mai; Tsubamoto, Hiroshi; Sakata, Kazuko; Oohama, Naoko; Hayakawa, Hitomi; Kojima, Teruhito; Shigeta, Minoru; Shibahara, Hiroaki

    2016-03-01

    The aim of this study was to establish a simple tool to predict good-quality embryos in in vitro fertilization (IVF) by using cumulus cells (CCs) or peripheral blood cells (PBCs). Mitochondrial DNA was extracted from CCs and PBCs in patients undergoing IVF. Using real-time polymerase chain reaction, mtDNA copy number in a single cell was calculated. Embryo quality was assessed when it was transferred or frozen. CCs were obtained from 60 oocyte cumulus-cell complexes (OCCCs) in 30 women, and PBCs were collected from 18 women. For the 30 women in the study, the median age was 37 years old (range, 24-43), and the mean body mass index was 21.4 (standard error, 2.0). mtDNA content of CCs and PBCs was highly correlated (Pearson's r = 0.900, p good- and poor-quality embryos was 140 and 57, respectively (p good- and poor-quality embryos was 36 and 13, respectively (p = 0.604). The logistic regression model indicated that mtDNA content in CCs was the only parameter that predicted good-quality embryos (p = 0.020). The receiver operating characteristic curve for obtaining good-quality embryos by mtDNA copy number in CCs had an area under the curve of 0.823, and using a threshold of 86, positive and negative predictive values were 84.4 and 82.1 %, respectively. The determination of mtDNA content in CCs can be used to predict good-quality embryos.

  3. Carbon-activated gas filtration during in vitro culture increased pregnancy rate following transfer of in vitro-produced bovine embryos.

    Science.gov (United States)

    Merton, J S; Vermeulen, Z L; Otter, T; Mullaart, E; de Ruigh, L; Hasler, J F

    2007-04-15

    Many environmental conditions for in vitro embryo production (IVP) systems for cattle have been relatively standardised, e.g. media composition, temperature, pH, water quality, and atmospheric composition. However, little attention has been paid to the quality of ambient laboratory air and the gas environment in incubators. Although a few studies have examined the effects of chemical air contamination on IVP of human embryos, there are no published accounts for domestic animal embryos. Therefore, this study investigated the effects of an intra-incubator carbon-activated air filtration system (CODA) during in vitro culture (IVC) on embryonic development and subsequent pregnancy rate of bovine embryos. Immature cumulus-oocyte-complexes (COCs) were obtained twice-weekly by ultrasonic-guided transvaginal oocyte aspiration. The COCs were matured in TCM199/FCS/LH/FSH, fertilized with frozen-thawed Percoll-separated semen, and subsequently cultured for 7 day in SOFaaBSA. Day 7 embryos were transferred either fresh or frozen/thawed. The experimental design was a 2 x 2 factorial; presumptive zygotes were placed either in a conventional CO(2)-O(2)-N(2) incubator (Control group) or in an identical CO(2)-O(2)-N(2) incubator with a CODA intra-incubator air purification unit (CODA group) for IVC. The embryo production rate at Day 7 was not affected by the CODA air purification unit (23.4 and 24.7% morulae and blastocysts per oocyte for control and CODA, respectively) nor was there any significant effect on embryo stage or quality. However, the pregnancy rate was improved (P=0.043) for both fresh (46.3% versus 41.0%) and frozen/thawed embryos (40.8% versus 35.6%). In conclusion, atmospheric purification by the CODA intra-incubator air purification unit significantly increased pregnancy rate following transfer of in vitro-produced bovine embryos.

  4. Studies of In Vitro Embryo Culture of Guppy (Poecilia reticulata).

    Science.gov (United States)

    Liu, LiLi; Lee, Ki-Young

    2014-09-01

    Different with other fishes, the guppies (Poecilia reticulata) is ovoviviparity, which retain their fertilized eggs within the follicle throughout gestation. The synchronously growing diplotene oocytes store nutrients in droplets and yolk, before their maturation and fertilization. The lecithotrophic strategy of development entails the provisioning of embryos with resources from the maternal yolk deposit rather than from a placenta, it allows the extracorporeal culture of guppy embryo. Studies on their early development of live bearers like the guppy including lineage tracing and genetic manipulations, have been limited. Therefore, to optimize conditions of embryo in vitro culture, explanted embryos from pregnant females were incubated in embryo medium (L-15 medium, supplemented with 5, 10, 15, 20% fetal bovine serum, respectively). We investigated whether the contents of FBS in vitro culture medium impact the development of embryos, and whether they would hatch in vitro. Our study found that in 5% of FBS of the medium, although embryos developed significantly slower in vitro than in the ovary, it was impossible to exactly quantify the developmental delay in culture, due to the obvious spread in developmental stage within each batch of eggs, and embryos can only be maintained until the early-eyed. And although in culture with 20% FBS the embryos can sustain rapid development of early stage, but cannot be cultured for the entire period of their embryonic development and ultimately died. In the medium with 10% and 15% FBS, the embryos seems well developed, even some can continue to grow after follicle ruptures until it can be fed. We also observed that embryonic in these two culture conditions were significantly different in development speed, in 15% it is faster than 10%. But 10% FBS appears to be more optimizing condition than 15% one on development process of embryos and survival rate to larvae stage.

  5. Cryopreservation of coffee zygotic embryos: dehydration and osmotic rehydration

    Directory of Open Access Journals (Sweden)

    Maísa de Siqueira Pinto

    Full Text Available ABSTRACT Conservation of plant genetic resources is important to prevent genetic erosion. Seed banks are the most common method of ex situ conservation; however, coffee seeds can not be stored by conventional methods. Cryopreservation is a viable alternative for long-term conservation of species that produce intermediate or recalcitrant seeds, as coffee. The aim of this work was to cryopreserve Coffea arabica L. cv Catuaí Vermelho IAC 144 zygotic embryos, and analyse the effects of dehydration prior cryopreservation and osmotic rehydration after thawing, in embryos germination and seedlings formation after cryopreservation. Prior to cryopreservation, different dehydration times (0, 15, 30, 60 and 120 min were tested. Dehydrated embryos were cryopreserved in liquid nitrogen for 1 hour, and after thawing were rehydrated by osmotic solutions. Dehydrated and non-cryopreserved embryos were also analysed. The test with 2,3,5 triphenyl tetrazolium chloride (TTC was used to evaluate the embryos viability. Non-dehydrated embryos did not survive after freezing. Embryos that were dehydrated until 20% of the moisture content did not germinate when osmotic rehydration was not performed. In contrast, cryopreserved embryos with the same moisture content presented 98% germination when they were rehydrated slowly in osmotic solution. According to tetrazolium tests, embryos presented maximum viability (75% after dehydration for 60 minutes (23% moisture content. Therefore, coffee zygotic embryos (Coffea arabica L. cv. Catuaí Vermelho can be successfully cryopreserved using physical dehydration in silica gel for 60 minutes (23% moisture content, followed by osmotic rehydration after thawing. This method allowed a germination of 98% of cryopreserved zygotic embryos.

  6. Precocious germination and its regulation in embryos of triticale caryopses

    Directory of Open Access Journals (Sweden)

    Stanisław Weidner

    2014-01-01

    Full Text Available Triticale var. Lasko embryos, isolated from grain gathered at milk ripeness, the beginning of wax ripeness and at full ripeness, were allowed to germinate for 48 h on agar with glucose. The highest incorporation of tritiated adenosine into polyribosomal RNA during germination was found in the ribosome fractions from embryos of grain gathered at full ripeness, lower incorporation was in preparations from embryos of milk ripe grain and the lowest in preparations from embryos of wax ripe grain. Different tendencies were observed in respect to the synthesis of ribosomal proteins. The highest incorporation of 14C-amino acids into ribosomal proteins was found in preparations of ribosome fractions from embryos of milk ripe grain, lower in preparations of embryos from fully ripe grain, the lowest in preparations of embryos from wax ripe grain. ABA (10-4 M completely inhibited the external symptoms of germination of immature embryos, while its inhibition of the synthesis of polyribosomal RNA and ribosomal proteins was greater the more mature the embryos that were germinated. The greatest stimulation of precocious germination by exogenous BA and GA3 was demonstrated in the least mature embryos isolated from milk ripe grain. Under the influence of both stimulators, an increase of the proportion of polyribosomes in the total ribosome fraction occurred in this sample, as did a rise in the intensity of ribosomal protein synthesis. The incorporation of 3H-adenosine into polyribosomal RNA, however, was lower than in the control sample. The results obtained suggest that the regulation of precocious germination of triticale embryos by phyto-hormones is not directly related to transcription.

  7. Effects of the ageing of microporous heat-insulating materials on temperature control in steel casting ladles; Auswirkungen der Alterung von mikroporoesen Waermedaemmstoffen auf die Temperaturfuehrung von Stahlgiesspfannen

    Energy Technology Data Exchange (ETDEWEB)

    Buhr, A.; Felsch, T.; Hoever, P. [Thyssen Krupp Stahl AG, Dortmund (Germany); Bauer, W. [Duisburg Univ. (Gesamthochschule) (Germany). Fachbereich Huettentechnik und Giessereitechnik; Feja, D. [Muenster Univ. (Germany). Inst. fuer Mineralogie

    1998-12-15

    With steel casting ladles developing from pure transfer vessels into metallurgical reactors, the exact control of the melt temperature in the ladles has become co-decisive for the production of high-grade quality steel. A thermal model used for such temperature control was to undergo verification by comparing the shell temperature calculated and measured for high-alumina- and basic-lined steel casting ladles. The shell temperature calculated in the thermal model for the steel casting ladles during circulation was verified by infrared thermography. While there is a good concurrence for high-alumina-lined steel casting ladles, with maximum variations of 15 K emerging, appreciable variations as great as some 45 K were found for basic-lined ladles. The cause of these variations lies in material changes in the form of shrinkage, carbon deposits and single particle growth of the microporous panels utilised for heat insulation. This results in increased thermal conductivity. The variations are reduced to a maximum of 8 K, also for basic-lined ladles, with corrected material data. Given the progressive ageing of the insulating panels in the permanent safety lining, it appears advisable to set a maximum operating time as a function of the conditions prevailing in the steel plant in each case so as to avoid excessive heat losses. (orig.) [Deutsch] Mit der Entwicklung der Stahlgiesspfanne vom reinen Transportgefaess zum metallurgischen Reaktor wurde die exakte Temperaturfuehrung der Schmelze in der Pfanne mitentscheidend fuer die Erzeugung qualitativ hochwertigen Stahls. Ein zur Temperaturfuehrung eingesetztes waermetechnisches Modell sollte durch Vergleich von berechneter und gemessener Manteltemperatur von aluminareich und basisch zugestellten Stahlgiesspfannen ueberprueft werden. Die im waermetechnischen Modell berechnete Manteltemperatur der Stahlgiesspfannen waehrend des Umlaufs wurde mit Infrarotthermografie ueberprueft. Waehrend bei aluminareich zugestellten

  8. Was the Little Ice Age more or less El Niño-like than the Medieval Climate Anomaly? Evidence from hydrological and temperature proxy data

    Science.gov (United States)

    Henke, Lilo M. K.; Lambert, F. Hugo; Charman, Dan J.

    2017-03-01

    The El Niño-Southern Oscillation (ENSO) is the most important source of global climate variability on interannual timescales and has substantial environmental and socio-economic consequences. However, it is unclear how it interacts with large-scale climate states over longer (decadal to centennial) timescales. The instrumental ENSO record is too short for analysing long-term trends and variability and climate models are unable to accurately simulate past ENSO states. Proxy data are used to extend the record, but different proxy sources have produced dissimilar reconstructions of long-term ENSO-like climate change, with some evidence for a temperature-precipitation divergence in ENSO-like climate over the past millennium, in particular during the Medieval Climate Anomaly (MCA; AD ˜ 800-1300) and the Little Ice Age (LIA; AD ˜ 1400-1850). This throws into question the stability of the modern ENSO system and its links to the global climate, which has implications for future projections. Here we use a new statistical approach using weighting based on empirical orthogonal function (EOF) to create two new large-scale reconstructions of ENSO-like climate change derived independently from precipitation proxies and temperature proxies. The method is developed and validated using model-derived pseudo-proxy experiments that address the effects of proxy dating error, resolution, and noise to improve uncertainty estimations. We find no evidence that temperature and precipitation disagree over the ENSO-like state over the past millennium, but neither do they agree strongly. There is no statistically significant difference between the MCA and the LIA in either reconstruction. However, the temperature reconstruction suffers from a lack of high-quality proxy records located in ENSO-sensitive regions, which limits its ability to capture the large-scale ENSO signal. Further expansion of the palaeo-database and improvements to instrumental, satellite, and model representations of

  9. Macroevolutionary developmental biology: Embryos, fossils, and phylogenies.

    Science.gov (United States)

    Organ, Chris L; Cooper, Lisa Noelle; Hieronymus, Tobin L

    2015-10-01

    The field of evolutionary developmental biology is broadly focused on identifying the genetic and developmental mechanisms underlying morphological diversity. Connecting the genotype with the phenotype means that evo-devo research often considers a wide range of evidence, from genetics and morphology to fossils. In this commentary, we provide an overview and framework for integrating fossil ontogenetic data with developmental data using phylogenetic comparative methods to test macroevolutionary hypotheses. We survey the vertebrate fossil record of preserved embryos and discuss how phylogenetic comparative methods can integrate data from developmental genetics and paleontology. Fossil embryos provide limited, yet critical, developmental data from deep time. They help constrain when developmental innovations first appeared during the history of life and also reveal the order in which related morphologies evolved. Phylogenetic comparative methods provide a powerful statistical approach that allows evo-devo researchers to infer the presence of nonpreserved developmental traits in fossil species and to detect discordant evolutionary patterns and processes across levels of biological organization. © 2015 Wiley Periodicals, Inc.

  10. Tracking individual nanodiamonds in Drosophila melanogaster embryos

    CERN Document Server

    Simpson, David A; Kowarsky, Mark; Zeeshan, Nida F; Barson, Michael S J; Hall, Liam; Yan, Yan; Kaufmann, Stefan; Johnson, Brett C; Ohshima, Takeshi; Caruso, Frank; Scholten, Robert; Saint, Robert B; Murray, Michael J; Hollenberg, Lloyd C L

    2013-01-01

    Tracking the dynamics of fluorescent nanoparticles during embryonic development allows insights into the physical state of the embryo and, potentially, molecular processes governing developmental mechanisms. In this work, we investigate the motion of individual fluorescent nanodiamonds micro-injected into Drosophila melanogaster embryos prior to cellularisation. Fluorescence correlation spectroscopy and wide-field imaging techniques are applied to individual fluorescent nanodiamonds in blastoderm cells during stage 5 of development to a depth of ~40 \\mu m. The majority of nanodiamonds in the blastoderm cells during cellularisation exhibit free diffusion with an average diffusion coefficient of (6 $\\pm$ 3) x 10$^{-3}$ \\mu m$^2$/s, (mean $\\pm$ SD). Driven motion in the blastoderm cells was also observed with an average velocity of 0.13 $\\pm$ 0.10 \\mu m/s (mean $\\pm$ SD) \\mu m/s and an average applied force of 0.07 $\\pm$ 0.05 pN (mean $\\pm$ SD). Nanodiamonds in the periplasm between the nuclei and yolk were also...

  11. The factors affecting the outcome of frozen–thawed embryo transfer cycle

    Directory of Open Access Journals (Sweden)

    Mahnaz Ashrafi

    2011-06-01

    Conclusion: Protocol type, gonadotrophin preparations, fresh-cycle outcome, endometrial thickness and the numbers of obtained oocytes, embryos, and high-quality thawed embryos transferred are the factors affecting pregnancy outcome of frozen–thawed embryo transfer.

  12. Principles guiding embryo selection following genome-wide haplotyping of preimplantation embryos.

    Science.gov (United States)

    Dimitriadou, Eftychia; Melotte, Cindy; Debrock, Sophie; Esteki, Masoud Zamani; Dierickx, Kris; Voet, Thierry; Devriendt, Koen; de Ravel, Thomy; Legius, Eric; Peeraer, Karen; Meuleman, Christel; Vermeesch, Joris Robert

    2017-03-01

    How to select and prioritize embryos during PGD following genome-wide haplotyping? In addition to genetic disease-specific information, the embryo selected for transfer is based on ranking criteria including the existence of mitotic and/or meiotic aneuploidies, but not carriership of mutations causing recessive disorders. Embryo selection for monogenic diseases has been mainly performed using targeted disease-specific assays. Recently, these targeted approaches are being complemented by generic genome-wide genetic analysis methods such as karyomapping or haplarithmisis, which are based on genomic haplotype reconstruction of cell(s) biopsied from embryos. This provides not only information about the inheritance of Mendelian disease alleles but also about numerical and structural chromosome anomalies and haplotypes genome-wide. Reflections on how to use this information in the diagnostic laboratory are lacking. We present the results of the first 101 PGD cycles (373 embryos) using haplarithmisis, performed in the Centre for Human Genetics, UZ Leuven. The questions raised were addressed by a multidisciplinary team of clinical geneticist, fertility specialists and ethicists. Sixty-three couples enrolled in the genome-wide haplotyping-based PGD program. Families presented with either inherited genetic variants causing known disorders and/or chromosomal rearrangements that could lead to unbalanced translocations in the offspring. Embryos were selected based on the absence or presence of the disease allele, a trisomy or other chromosomal abnormality leading to known developmental disorders. In addition, morphologically normal Day 5 embryos were prioritized for transfer based on the presence of other chromosomal imbalances and/or carrier information. Some of the choices made and principles put forward are specific for cleavage-stage-based genetic testing. The proposed guidelines are subject to continuous update based on the accumulating knowledge from the implementation of

  13. Embryo cryopreservation and in vitro culture of preimplantation embryos in Campbell's hamster (Phodopus campbelli).

    Science.gov (United States)

    Amstislavsky, Sergei; Brusentsev, Eugeny; Kizilova, Elena; Igonina, Tatyana; Abramova, Tatyana; Rozhkova, Irina

    2015-04-01

    The aims of this study were to compare different protocols of Campbell's hamster (Phodopus campbelli) embryos freezing-thawing and to explore the possibilities of their in vitro culture. First, the embryos were flushed from the reproductive ducts 2 days post coitum at the two-cell stage and cultured in rat one-cell embryo culture medium (R1ECM) for 48 hours. Most (86.7%) of the two-cell embryos developed to blastocysts in R1ECM. Second, the embryos at the two- to eight-cell stages were flushed on the third day post coitum. The eight-cell embryos were frozen in 0.25 mL straws according to standard procedures of slow cooling. Ethylene glycol (EG) was used either as a single cryoprotectant or in a mixture with sucrose. The survival of frozen-thawed embryos was assessed by double staining with fluorescein diacetate and propidium iodide. The use of EG as a single cryoprotectant resulted in fewer alive embryos when compared with control (fresh embryos), but combined use of EG and sucrose improved the survival rate after thawing. Furthermore, granulocyte-macrophage colony-stimulating factor rat (2 ng/mL) improved the rate of the hamster frozen-thawed embryo development in vitro by increasing the final cell number and alleviating nuclear fragmentation. Our data show the first attempt in freezing and thawing Campbell's hamster embryos and report the possibility of successful in vitro culture for this species in R1ECM supplemented with granulocyte-macrophage colony-stimulating factor. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Successful pregnancies from vitrified embryos in the dromedary camel: Avoidance of a possible toxic effect of sucrose on embryos.

    Science.gov (United States)

    Herrid, M; Billah, M; Skidmore, J A

    2017-12-01

    Successful embryo cryopreservation facilitates the wider application of assisted reproduction technologies and also provides a useful method for gene banking of valuable genetics. Unfortunately attempts to establish an effective cryopreservation protocol for camelid embryos have been unsuccessful. In the current study, a modified vitrification protocol with three steps was investigated, whereby embryos were exposed to solutions containing increasing amounts of glycerol and ethylene glycol for fixed time periods. Embryos were then loaded into an Open Pull Straw (OPS) and plunged directly into liquid nitrogen for storage. Three experiments were designed to investigate the effect of 1) artificial shrinkage (AS) of embryos, 2) the addition of sucrose to the vitrification solutions, and 3) the replacement of sucrose by galactose in the warming solution, on the outcome of vitrification. The results showed that neither AS of hatched embryos prior to vitrification, nor the addition of sucrose into vitrification solutions improves the outcome of vitrification, while replacement of sucrose with galactose in warming solution increases the survival and developmental rates of vitrified embryos in culture. Transfer of vitrified embryos that were warmed in galactose resulted in a pregnancy rate of 42.8% per embryo or 46.1% per recipient. Collectively, these results suggest a possible species-specific toxic effect of sucrose on camel embryos, and that avoiding its use either in vitrification or warming solution is critical for establishing an effective protocol. This study may also be applicable to the vitrification of embryos of other camelid species including alpaca and llamas. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Embryo rescue of crosses between diploid and tetraploid grape ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-19

    Dec 19, 2011 ... tetraploid grapes can be a good way to obtain new triploid germplasm. However, there exists a severe mating obstacle in crosses between diploid and tetraploid grape. The embryo rescue technique may prevent the early stage abortion of triploid young embryo, so triploid plants can be produced (Pan et al., ...

  16. Sexing bovine pre-implantation embryos using the polymerase ...

    African Journals Online (AJOL)

    Yomi

    2012-03-06

    Mar 6, 2012 ... can also be applied to human embryos, using different primers, designed for human DNA. Key words: sexing, embryo, PCR, bovine. INTRODUCTION. In vitro fertilization represents nowadays a modern assisted reproductive technology that can be applied to couples with fertility problems that make natural ...

  17. Factors affecting conception rates in cattle following embryo transfer ...

    African Journals Online (AJOL)

    Embryo Transfer Technology (ETT) plays an important role in improving productivity of dairy cattle (Bos indicus). Embryo Transfer Technology allows top quality female livestock to improve a herd or flock in much the same way that artificial insemination has allowed greater use of superior sires. The technology hastens ...

  18. Fruit, seed and embryo development of different cassava (Manihot ...

    African Journals Online (AJOL)

    Fruit, seed and embryo developments of different cassava (Manihot esculenta Crantz) genotypes, as well as embryo rescue, were investigated. The fruits of three genotypes after uncontrolled open pollination presented the same progressive development with similar sizes at different stages. There are large differences in ...

  19. In vitro bulblet regeneration from immature embryos of Muscari ...

    African Journals Online (AJOL)

    A high frequency bulblet regeneration was achieved for endemic and endangered ornamental plant Muscari azureum using immature embryos. Immature embryos of M. azureum were cultured on callus induction medium consisting of N6 mineral salts and vitamins, 400 mg/L casein + 40 g/L sucrose + 2 g/l L-proline, 2 mg/L ...

  20. Plant regeneration from immature embryos of Kenyan maize inbred ...

    African Journals Online (AJOL)

    Field grown, self pollinated maize genotypes were planted in KARI (Kiboko and Kabete) research stations between January 2004 and May 2005. Immature maize embryos from twelve parental inbred lines and their respective single cross hybrids were evaluated for their ability form callus, somatic embryos and subsequent ...

  1. Mouse embryos cultured in amniotic fluid | Oettle | South African ...

    African Journals Online (AJOL)

    One thousand mouse embryos were collected over a period of 6 weeks·and randomly assigned to either amniotic fluid aspirated during routine amniocentesis from normal 16 weeks pregnant patients or Earle's medium. The embryos were cultured for 72 hours at 37°C in 5% carbon dioxide in air. Osmolarity, pH, partial ...

  2. Induction of microspore-derived embryos by anther culture in ...

    African Journals Online (AJOL)

    Five pepper genotypes (A71, A269, A313, A109 and A74) and four different culture media were tested in this study carried out at the University of Çukurova, Turkey. The anthers were cultured at different periods in order to optimize the frequency of embryo production. Moreover, the embryos that were unable to complete ...

  3. Early embryo development in Fucus distichus is auxin sensitive

    Science.gov (United States)

    Basu, Swati; Sun, Haiguo; Brian, Leigh; Quatrano, Ralph L.; Muday, Gloria K.

    2002-01-01

    Auxin and polar auxin transport have been implicated in controlling embryo development in land plants. The goal of these studies was to determine if auxin and auxin transport are also important during the earliest stages of development in embryos of the brown alga Fucus distichus. Indole-3-acetic acid (IAA) was identified in F. distichus embryos and mature tissues by gas chromatography-mass spectroscopy. F. distichus embryos accumulate [(3)H]IAA and an inhibitor of IAA efflux, naphthylphthalamic acid (NPA), elevates IAA accumulation, suggesting the presence of an auxin efflux protein complex similar to that found in land plants. F. distichus embryos normally develop with a single unbranched rhizoid, but growth on IAA leads to formation of multiple rhizoids and growth on NPA leads to formation of embryos with branched rhizoids, at concentrations that are active in auxin accumulation assays. The effects of IAA and NPA are complete before 6 h after fertilization (AF), which is before rhizoid germination and cell division. The maximal effects of IAA and NPA are between 3.5 and 5 h AF and 4 and 5.5 h AF, respectively. Although, the location of the planes of cell division was significantly altered in NPA- and IAA-treated embryos, these abnormal divisions occurred after abnormal rhizoid initiation and branching was observed. The results of this study suggest that auxin acts in the formation of apical basal patterns in F. distichus embryo development.

  4. Epigenetics and chromosome segregation in human pre-implantation embryos

    NARCIS (Netherlands)

    C. van de Werken (Christine)

    2015-01-01

    markdownabstractAbstract Chapter 1 Currently, the average pregnancy rate per embryo transfer after in vitro fertilization (IVF) is around 32%. In order to achieve better results in the future, we need to gain knowledge on all aspects of the treatment, including pre-implantation embryo

  5. The role of auxin signaling in early embryo pattern formation

    NARCIS (Netherlands)

    Smit, Margot E.; Weijers, Dolf

    2015-01-01

    Pattern formation of the early Arabidopsis embryo generates precursors to all major cell types, and is profoundly controlled by the signaling molecule auxin. Here we discuss recent milestones in our understanding of auxin-dependent embryo patterning. Auxin biosynthesis, transport and response

  6. Storage oil breakdown during embryo development of Brassica napus (L.).

    Science.gov (United States)

    Chia, Tansy Y P; Pike, Marilyn J; Rawsthorne, Stephen

    2005-05-01

    In this study it is shown that at least 10% of the major storage product of developing embryos of Brassica napus (L.), triacylglycerol, is lost during the desiccation phase of seed development. The metabolism of this lipid was studied by measurements of the fate of label from [1-(14)C]decanoate supplied to isolated embryos, and by measurements of the activities of enzymes of fatty acid catabolism. Measurements on desiccating embryos have been compared with those made on embryos during lipid accumulation and on germinating seedlings. Enzymes of beta-oxidation and the glyoxylate cycle, and phosphoenolpyruvate carboxykinase were present in embryos during oil accumulation, and increased in activity and abundance as the seeds matured and became desiccated. Although the activities were less than those measured during germination, they were at least comparable to the in vivo rate of fatty acid synthesis in the embryo during development. The pattern of labelling, following metabolism of decanoate by isolated embryos, indicated a much greater involvement of the glyoxylate cycle during desiccation than earlier in oil accumulation, and showed that much of the (14)C-label from decanoate was released as CO(2) at both stages. Sucrose was not a product of decanoate metabolism during embryo development, and therefore lipid degradation was not associated with net gluconeogenic activity. These observations are discussed in the context of seed development, oil yield, and the synthesis of novel fatty acids in plants.

  7. Lack of carbon air filtration impacts early embryo development.

    Science.gov (United States)

    Munch, Erika M; Sparks, Amy E; Duran, Hakan E; Van Voorhis, Bradley J

    2015-07-01

    To assess human fertilization and preimplantation embryo development in the presence and in the absence of carbon filtration This is a retrospective cohort analysis of fresh, controlled ovarian hyperstimulation cycles as well as previously cryopreserved pronuclear stage embryo transfer cycles in a single IVF center. Embryo development and cycle-based outcomes were compared among three groups: 1) when carbon filtration was present, 2) when carbon filtration was absent, and 3) when carbon filtration had been restored. A total of 524 fresh cycles and 156 cryopreserved embryo cycles were analyzed. Fertilization, cleavage, and blastocyst conversion rates for fresh cycles all declined during the period of absent carbon filtration and recovered after the restoration of carbon filtration. Cryopreserved embryos that were thawed and cultured during the period of absent filtration did not have changes in cleavage or blastocyst conversion rates compared to periods where carbon filtration was present. Clinical pregnancy and live birth rates were unchanged among the three time periods. The absence of carbon filtration in an IVF laboratory air handler is associated with poor fertilization and early embryo development for fresh cycles. Because development of previously frozen pronuclear stage embryos was unaffected, the lack of carbon filtration may preferentially affect embryos in the peri-fertilization period. Carbon filtration is an integral part to a successful human in-vitro fertilization laboratory.

  8. Effects of LeY glycan expression on embryo implantation.

    Science.gov (United States)

    Gu, J; Sui, L-L; Cui, D; Ma, Y-N; Zhu, C-Y; Kong, Y

    2016-08-01

    To investigate the correlation between LeY glycan expression and embryo implantation. Uterine epithelial cells before implantation were transfected with FUT1siRNA to inhibit FUT1 (the gene encoding the key enzyme of LeY synthesis) expression and treated with 10 ng/ml leukemia inhibitory factor (LIF). Murine embryo implantation model in vitro was prepared by late blastocysts with identical morphology and treated uterine epithelial cells co-culture. Using RT-PCR, dot blot and observation of embryo attachment to analyze FUT1 gene expression and LeY synthesis of uterine epithelial cells and studied further the correlation of LeY expression level and embryo implantation. FUT1 gene expression and LeY synthesis declined after cells were transfected with FUT1siRNA, and LIF promoted FUT1 expression and LeY synthesis. After expression of FUT1 gene was inhibited, attachment rate of embryos lowered, but LIF up-regulated FUT1 expression and increased the attachment rate of embryos. These results indicated regulating FUT1 expression affected LeY synthesis, and then LeY regulated the recognition and attachment of uterus-embryo and participates in embryo implantation further.

  9. The development of ovary in quail's embryo | Rong | African Journal ...

    African Journals Online (AJOL)

    The results showed that when embryo was hatched for 4 days, lots of primordial germ cells (PGCs) clustered in the region where gonad would be formed. On the 5th day of hatching, the gonad of the embryo began to be formed and exhibited the feature of ovary or testis. On the 7th hatching day, the right ovary began to ...

  10. Development of the ventral body wall in the human embryo

    NARCIS (Netherlands)

    Mekonen, Hayelom K.; Hikspoors, Jill P. J. M.; Mommen, Greet; Köhler, S. Eleonore; Lamers, Wouter H.

    2015-01-01

    Migratory failure of somitic cells is the commonest explanation for ventral body wall defects. However, the embryo increases ~ 25-fold in volume in the period that the ventral body wall forms, so that differential growth may, instead, account for the observed changes in topography. Human embryos

  11. Closure of the vertebral canal in human embryos and fetuses

    NARCIS (Netherlands)

    Mekonen, Hayelom K.; Hikspoors, Jill P. J. M.; Mommen, Greet; Kruepunga, Nutmethee; Köhler, S. Eleonore; Lamers, Wouter H.

    2017-01-01

    The vertebral column is the paradigm of the metameric architecture of the vertebrate body. Because the number of somites is a convenient parameter to stage early human embryos, we explored whether the closure of the vertebral canal could be used similarly for staging embryos between 7 and 10weeks of

  12. Optimal developmental stage for vitrification of parthenogenetically activated porcine embryos

    DEFF Research Database (Denmark)

    Li, Rong; Li, Juan; Liu, Ying

    2012-01-01

    -lapse monitored for 24 h or analyzed by diffential staining. After warming, the embryos had to be cultured for at least 8 h before their survival rates were stabilized. Both the survival rate and 8 h and the hatching rate at 24 h of Day 4 embryos were significantly higher than those vitrified on Day5 or Day 6 (P...

  13. Chromosomal mosaicism in human preimplantation embryos : a systematic review

    NARCIS (Netherlands)

    van Echten-Arends, Jannie; Mastenbroek, Sebastiaan; Sikkema-Raddatz, Birgit; Korevaar, Johanna C.; Heineman, Maas Jan; van der Veen, Fulco; Repping, Sjoerd

    2011-01-01

    BACKGROUND: Although chromosomal mosaicism in human preimplantation embryos has been described for almost two decades, its exact prevalence is still unknown. The prevalence of mosaicism is important in the context of preimplantation genetic screening in which the chromosomal status of an embryo is

  14. Superovulation and embryo recovery in Boer goats treated with ...

    African Journals Online (AJOL)

    Lehloenya

    semen were performed 36 h and 48 h following CIDR removal and the embryos surgically flushed six days after the second AI. The oestrous response, onset- and ..... Increased embryo development and metabolism following short term storage of bovine IVP blastocysts at 25 ºC in EmcareTM compared to ovum culture.

  15. Embryo implantation: Shedding light on the roles of ovarian ...

    African Journals Online (AJOL)

    Successful implantation requires coordinated interactions between the blastocyst and uterus. Uterine receptivity for embryo implantation is regulated by the ovarian hormones estrogen and progesterone. Some cytokines and growth factors play important roles in embryo implantation under the influence of ovarian hormones.

  16. Human embryo-conditioned medium stimulates in vitro endometrial angiogenesis

    NARCIS (Netherlands)

    Kapiteijn, K.; Koolwijk, P.; Weiden, R.M.F. van der; Nieuw Amerongen, G. van; Plaisier, M.; Hinsbergh, V.W.M. van; Helmerhorst, F.M.

    2006-01-01

    Objective: Successful implantation and placentation depend on the interaction between the endometrium and the embryo. Angiogenesis is crucial at this time. In this article we investigate the direct influence of the human embryo on in vitro endometrial angiogenesis. Design: In vitro study. Setting:

  17. Use of blue crab (Callinectes sapidus) embryos for toxicity testing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, R.; O`Malley, K. [Skidaway Inst. of Oceanography, Savannah, GA (United States)

    1995-12-31

    After fertilization, blue crab embryos develop in egg sacs attached to the female pleopods, often referred to as the sponge. Lipovitellin and lipid droplets in the egg sacs provide energy and nutrition for the developing embryos. Embryos were removed from the sponge and transferred to 24 well culture plates containing sea water with or without toxicants, Each well contained 10 embryos. After 7 to 10 days, embryos hatched to swimming zoea. The effects of toxicants at various concentrations on hatching were determined and the EC{sub 50} calculated. For example, the EC{sub 50} for tributyltin, fenvalerate and mercuric chloride were 50, 30 and 90 ng/liter, respectively. The hatching success of control embryos ranged from 95 to 98%. Formation of the heart, eyespot formation, appendage formation and utilization rate of lipovitellin were also effected by exposure to toxicants. At a low concentration of mercuric ion (30ng/liter) the heart formed, but there was no heart beat. Eyespot formation was abnormal in the presence of high concentrations of cadmium (2 {micro}g/liter) and zinc (5 {micro}g/liter), Crab embryos offer many advantages for toxicity testing of pure compounds or mixtures in water, including toxicity testing of sediment pore water. The crab embryos may also serve as models to understand the effect of specific toxicants on the heart and eye spots of crustaceans.

  18. Chromosomal polymorphisms are independently associated with multinucleated embryo formation.

    Science.gov (United States)

    Sun, Ling; Chen, Zhi-Heng; Yang, Li; Yi, Cui-Xing; Liu, Jun; Ou, Chun-Quan

    2017-09-12

    The purpose of this study is to explore the factors associated with embryo multinucleation, particularly focused on the influence of parental chromosomal polymorphisms in embryo multinucleation. This is a retrospective case-control study involving 1260 infertile couples undergoing their first IVF/ICSI cycles. Couples were screened for abnormalities in their karyotype and were evaluated for blastomere persistence of multinucleation. Demographic characteristics, stimulation protocol, and pregnant outcomes were analyzed using logistic regression analysis. The level of basal FSH was lower in the multinucleated embryos group (5.37 vs 5.72 IU/L). The Multinucleated embryos group received less gonadotropins (1788.5 vs 1891.3 IU), and the level of LH on day of HCG triggering was lower (1.09 vs 1.30 IU/L). More oocytes were recovered in the multinucleated embryos group (11.51 vs 9.23). Chromosomal polymorphisms were seen in at least 1 out of 163 (12.9%) couples. Multivariate logistic regression analysis revealed that chromosomal polymorphisms were independently associated with an increase in the occurrence risk of multinucleated embryos (OR = 1.61, 95% CI, 1.06-2.44) in the first IVF/ICSI cycle. The miscarriage rate in the multinucleated embryos group was 10% higher than that of the control group. Chromosomal polymorphisms were independently associated with multinucleation embryo formation. A higher LH level on the day of HCG triggering was associated with a decreased chance of multinucleation.

  19. Successful pregnancy following trans-myometrial embryo transfer ...

    African Journals Online (AJOL)

    ... factor infertility (poor motility). Routine mock embryo transfer indicated severe cervical stenosis which was confirmed at hysteroscopy. She subsequently had trans-myometrial embryo transfer. Blood pregnancy test at 2 weeks was positive and interval transvaginal ultrasound confirmed 2 viable intrauterine foetal poles.