The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform

Andrea D Schreier - One of the best experts on this subject based on the ideXlab platform.

  • Mechanical Shock during egg de adhesion and post ovulatory ageing contribute to spontaneous autopolyploidy in white sturgeon culture acipenser transmontanus
    Aquaculture, 2020
    Co-Authors: Joel P Van Eenennaam, Aviva J Fiske, Michaiah J Leal, Chessie Cooleyrieders, Anne E Todgham, Fred S Conte, Andrea D Schreier
    Abstract:

    Abstract Spontaneous autopolyploidy, a 1.5x increase in genome size resulting from second polar body retention after fertilization, has been documented in cultured sturgeons, with the proportion of spontaneous autopolyploid progeny ranging widely among maternal families. Sturgeon farms wish to reduce the number of spontaneous autopolyploids because their progeny, when crossed with a normal ploidy parent, exhibit intermediate ploidies, resulting in reproductive abnormalities. However, there is limited knowledge of the causes of the second polar body retention in sturgeon culture. In this study, we report the results of experiments performed from 2015 to 2019 aimed at identifying the sources of spontaneous autopolyploidy in white sturgeon (Acipenser transmontanus) culture. In collaboration with several sturgeon farms, we tested whether post-ovulatory ageing, Mechanical Shock during egg de-adhesion, and the combined effects of both factors increased spontaneous autopolyploidy. To test the effect of post-ovulatory ageing, eggs were collected from females and either fertilized at the industry normative time (2–5 h post-oviposition) or stored in ovarian fluid at 15 °C for 6–8 h before fertilization. To test the effect of Mechanical Shock, eggs were collected, fertilized 2–5 h post-oviposition and exposed to either gentle or vigorous mixing during the 60 min de-adhesion treatment. Results from this work reveal that post-ovulatory ageing does increase the incidence of spontaneous autopolyploidy in some females, but overall the proportions produced were low (range 0–15%). Proportions of spontaneous autopolyploids in eggs exposed to vigorous mixing were also variable (1–92%) but significantly higher in 75% of the females when compared to their respective controls or gentle mixing treatments, indicating that Mechanical Shock during egg de-adhesion is likely the primary cause of spontaneous autopolyploidy. To our knowledge this is the first study to document Mechanical Shock to eggs during de-adhesion as a cause of abnormal ploidy in cultured fishes. We observed high variability in egg quality among females and a significant relationship between embryo mortality and the incidence of spontaneous autopolyploidy when eggs were exposed to Mechanical Shock. Repeated spawning of a female that produced a high proportion of spontaneous autopolyploids provided preliminary evidence that genetic background may influence the likelihood that a female's eggs will be prone to second polar body retention when subjected to Mechanical Shock. Although spontaneous autopolyploidy in sturgeon culture will likely never be eliminated entirely, we provide practical recommendations to sturgeon producers to reduce its incidence in a production setting.

Nikhilesh Chawla - One of the best experts on this subject based on the ideXlab platform.

  • rate dependent behavior of sn alloy cu couples effects of microstructure and composition on Mechanical Shock resistance
    Acta Materialia, 2012
    Co-Authors: Kyle Yazzie, Huiyang Fei, Hanqing Jiang, Nikhilesh Chawla
    Abstract:

    Abstract Solders serve as electrical and Mechanical interconnects in electronic packaging. The Mechanical Shock behavior of a Pb-free solder joint is quite complex, since the influences of solder microstructure, intermetallic compound (IMC) layer thickness, and strain rate on the overall dynamic solder joint strength need to be quantified. Dynamic solder joint strength is hypothesized to be controlled by two factors. At low strain rates it should be controlled by the bulk solder, whereas at high strain rates it may be controlled by the brittle intermetallic compound layer. In this paper, the dynamic solder joint strength of Sn–3.9 Ag–0.7 Cu solder joints was experimentally measured over the strain rate range 10 −3 –12 s −1 . The influences of changes in solder microstructure and IMC layer on dynamic solder joint strength were quantified, and visualized in three dimensions. Fracture mechanisms operating in the solder-controlled and IMC layer-controlled dynamic strength regimes are discussed. Finally, qualitative numerical simulations were conducted, which accurately depict the experimentally observed fracture behaviors.

  • thermoMechanical behaviour of environmentally benign pb free solders
    International Materials Reviews, 2009
    Co-Authors: Nikhilesh Chawla
    Abstract:

    Electronic packaging is a critical part of products such as computers, cellular phones, automotive components and other electronic devices. The package must be tailored to incorporate as many input/output interconnects as possible, in a limited amount of space. Until recently, most solder balls were made of a eutectic Pb–Sn alloy, because of its low melting point, excellent wetting characteristics and adequate creep and thermal fatigue strength. The potential health hazards associated with the toxicity of lead are significant. Given the widespread use of Pb–Sn solder in the manufacture and assembly of circuit boards, the development and reliability of new Pb-free solders is crucial for the successful substitution of these materials in the electronics industry. Pbfree solder alloys are complex materials with various important microstructural attributes. These include the nanoscale precipitates of Ag3Sn in Sn–Ag–Cu or Sn–Ag alloys, as well as Cu6Sn5 intermetallic formed at the interface between the solder and Cu metallisation. The Mechanical behaviour of solder alloys is extremely important because solder joints must retain their Mechanical integrity under a myriad of conditions such as creep, thermal fatigue, and Mechanical Shock and drop resistance. A significant amount of work has been carried out on the monotonic shear, creep and thermal fatigue resistance of these materials. An important new area of research is the Mechanical Shock and vibration fatigue behaviour of Pb-free solders. The developments in all these areas are critically examined in this paper.

  • microstructure and Mechanical behavior of novel rare earth containing pb free solders
    Journal of Electronic Materials, 2006
    Co-Authors: M A Dudek, Nikhilesh Chawla, Rajen S Sidhu, M Renavikar
    Abstract:

    Sn-rich solders have been shown to have superior Mechanical properties when compared to the Pb-Sn system. Much work remains to be done in developing these materials for electronic packaging. In this paper, we report on the microstructure and Mechanical properties of La-containing Sn-3.9Ag-0.7Cu alloys. The addition of small amounts of La (up to 0.5 wt.%) to Sn-Ag-Cu refined the microstructure by decreasing the length and spacing of the Sn dendrites and decreased the thickness of the Cu6Sn5 intermetallic layer at the Cu/solder interface. As a result of the change in the microstructure, Sn-Ag-Cu alloys with La additions exhibited a small decrease in ultimate shear strength but significantly higher elongations compared with Sn-Ag-Cu. The influence of LaSn3 intermetallics on microstructural refinement and damage evolution in these novel solders is discussed. Our results have profound implications for improving the Mechanical Shock resistance of Pb-free solders.

Joel P Van Eenennaam - One of the best experts on this subject based on the ideXlab platform.

  • Mechanical Shock during egg de adhesion and post ovulatory ageing contribute to spontaneous autopolyploidy in white sturgeon culture acipenser transmontanus
    Aquaculture, 2020
    Co-Authors: Joel P Van Eenennaam, Aviva J Fiske, Michaiah J Leal, Chessie Cooleyrieders, Anne E Todgham, Fred S Conte, Andrea D Schreier
    Abstract:

    Abstract Spontaneous autopolyploidy, a 1.5x increase in genome size resulting from second polar body retention after fertilization, has been documented in cultured sturgeons, with the proportion of spontaneous autopolyploid progeny ranging widely among maternal families. Sturgeon farms wish to reduce the number of spontaneous autopolyploids because their progeny, when crossed with a normal ploidy parent, exhibit intermediate ploidies, resulting in reproductive abnormalities. However, there is limited knowledge of the causes of the second polar body retention in sturgeon culture. In this study, we report the results of experiments performed from 2015 to 2019 aimed at identifying the sources of spontaneous autopolyploidy in white sturgeon (Acipenser transmontanus) culture. In collaboration with several sturgeon farms, we tested whether post-ovulatory ageing, Mechanical Shock during egg de-adhesion, and the combined effects of both factors increased spontaneous autopolyploidy. To test the effect of post-ovulatory ageing, eggs were collected from females and either fertilized at the industry normative time (2–5 h post-oviposition) or stored in ovarian fluid at 15 °C for 6–8 h before fertilization. To test the effect of Mechanical Shock, eggs were collected, fertilized 2–5 h post-oviposition and exposed to either gentle or vigorous mixing during the 60 min de-adhesion treatment. Results from this work reveal that post-ovulatory ageing does increase the incidence of spontaneous autopolyploidy in some females, but overall the proportions produced were low (range 0–15%). Proportions of spontaneous autopolyploids in eggs exposed to vigorous mixing were also variable (1–92%) but significantly higher in 75% of the females when compared to their respective controls or gentle mixing treatments, indicating that Mechanical Shock during egg de-adhesion is likely the primary cause of spontaneous autopolyploidy. To our knowledge this is the first study to document Mechanical Shock to eggs during de-adhesion as a cause of abnormal ploidy in cultured fishes. We observed high variability in egg quality among females and a significant relationship between embryo mortality and the incidence of spontaneous autopolyploidy when eggs were exposed to Mechanical Shock. Repeated spawning of a female that produced a high proportion of spontaneous autopolyploids provided preliminary evidence that genetic background may influence the likelihood that a female's eggs will be prone to second polar body retention when subjected to Mechanical Shock. Although spontaneous autopolyploidy in sturgeon culture will likely never be eliminated entirely, we provide practical recommendations to sturgeon producers to reduce its incidence in a production setting.

  • Mechanical Shock during egg de-adhesion and post-ovulatory ageing contribute to spontaneous autopolyploidy in white sturgeon culture (Acipenser transmontanus)
    eScholarship University of California, 2020
    Co-Authors: Joel P Van Eenennaam, Aviva J Fiske, Anne E Todgham, Mj Leal, Cooley-rieders C, Fs Conte, Ad Schreie
    Abstract:

    © 2019 The Authors Spontaneous autopolyploidy, a 1.5x increase in genome size resulting from second polar body retention after fertilization, has been documented in cultured sturgeons, with the proportion of spontaneous autopolyploid progeny ranging widely among maternal families. Sturgeon farms wish to reduce the number of spontaneous autopolyploids because their progeny, when crossed with a normal ploidy parent, exhibit intermediate ploidies, resulting in reproductive abnormalities. However, there is limited knowledge of the causes of the second polar body retention in sturgeon culture. In this study, we report the results of experiments performed from 2015 to 2019 aimed at identifying the sources of spontaneous autopolyploidy in white sturgeon (Acipenser transmontanus) culture. In collaboration with several sturgeon farms, we tested whether post-ovulatory ageing, Mechanical Shock during egg de-adhesion, and the combined effects of both factors increased spontaneous autopolyploidy. To test the effect of post-ovulatory ageing, eggs were collected from females and either fertilized at the industry normative time (2–5 h post-oviposition) or stored in ovarian fluid at 15 °C for 6–8 h before fertilization. To test the effect of Mechanical Shock, eggs were collected, fertilized 2–5 h post-oviposition and exposed to either gentle or vigorous mixing during the 60 min de-adhesion treatment. Results from this work reveal that post-ovulatory ageing does increase the incidence of spontaneous autopolyploidy in some females, but overall the proportions produced were low (range 0–15%). Proportions of spontaneous autopolyploids in eggs exposed to vigorous mixing were also variable (1–92%) but significantly higher in 75% of the females when compared to their respective controls or gentle mixing treatments, indicating that Mechanical Shock during egg de-adhesion is likely the primary cause of spontaneous autopolyploidy. To our knowledge this is the first study to document Mechanical Shock to eggs during de-adhesion as a cause of abnormal ploidy in cultured fishes. We observed high variability in egg quality among females and a significant relationship between embryo mortality and the incidence of spontaneous autopolyploidy when eggs were exposed to Mechanical Shock. Repeated spawning of a female that produced a high proportion of spontaneous autopolyploids provided preliminary evidence that genetic background may influence the likelihood that a female's eggs will be prone to second polar body retention when subjected to Mechanical Shock. Although spontaneous autopolyploidy in sturgeon culture will likely never be eliminated entirely, we provide practical recommendations to sturgeon producers to reduce its incidence in a production setting

Anne E Todgham - One of the best experts on this subject based on the ideXlab platform.

  • Mechanical Shock during egg de adhesion and post ovulatory ageing contribute to spontaneous autopolyploidy in white sturgeon culture acipenser transmontanus
    Aquaculture, 2020
    Co-Authors: Joel P Van Eenennaam, Aviva J Fiske, Michaiah J Leal, Chessie Cooleyrieders, Anne E Todgham, Fred S Conte, Andrea D Schreier
    Abstract:

    Abstract Spontaneous autopolyploidy, a 1.5x increase in genome size resulting from second polar body retention after fertilization, has been documented in cultured sturgeons, with the proportion of spontaneous autopolyploid progeny ranging widely among maternal families. Sturgeon farms wish to reduce the number of spontaneous autopolyploids because their progeny, when crossed with a normal ploidy parent, exhibit intermediate ploidies, resulting in reproductive abnormalities. However, there is limited knowledge of the causes of the second polar body retention in sturgeon culture. In this study, we report the results of experiments performed from 2015 to 2019 aimed at identifying the sources of spontaneous autopolyploidy in white sturgeon (Acipenser transmontanus) culture. In collaboration with several sturgeon farms, we tested whether post-ovulatory ageing, Mechanical Shock during egg de-adhesion, and the combined effects of both factors increased spontaneous autopolyploidy. To test the effect of post-ovulatory ageing, eggs were collected from females and either fertilized at the industry normative time (2–5 h post-oviposition) or stored in ovarian fluid at 15 °C for 6–8 h before fertilization. To test the effect of Mechanical Shock, eggs were collected, fertilized 2–5 h post-oviposition and exposed to either gentle or vigorous mixing during the 60 min de-adhesion treatment. Results from this work reveal that post-ovulatory ageing does increase the incidence of spontaneous autopolyploidy in some females, but overall the proportions produced were low (range 0–15%). Proportions of spontaneous autopolyploids in eggs exposed to vigorous mixing were also variable (1–92%) but significantly higher in 75% of the females when compared to their respective controls or gentle mixing treatments, indicating that Mechanical Shock during egg de-adhesion is likely the primary cause of spontaneous autopolyploidy. To our knowledge this is the first study to document Mechanical Shock to eggs during de-adhesion as a cause of abnormal ploidy in cultured fishes. We observed high variability in egg quality among females and a significant relationship between embryo mortality and the incidence of spontaneous autopolyploidy when eggs were exposed to Mechanical Shock. Repeated spawning of a female that produced a high proportion of spontaneous autopolyploids provided preliminary evidence that genetic background may influence the likelihood that a female's eggs will be prone to second polar body retention when subjected to Mechanical Shock. Although spontaneous autopolyploidy in sturgeon culture will likely never be eliminated entirely, we provide practical recommendations to sturgeon producers to reduce its incidence in a production setting.

  • Mechanical Shock during egg de-adhesion and post-ovulatory ageing contribute to spontaneous autopolyploidy in white sturgeon culture (Acipenser transmontanus)
    eScholarship University of California, 2020
    Co-Authors: Joel P Van Eenennaam, Aviva J Fiske, Anne E Todgham, Mj Leal, Cooley-rieders C, Fs Conte, Ad Schreie
    Abstract:

    © 2019 The Authors Spontaneous autopolyploidy, a 1.5x increase in genome size resulting from second polar body retention after fertilization, has been documented in cultured sturgeons, with the proportion of spontaneous autopolyploid progeny ranging widely among maternal families. Sturgeon farms wish to reduce the number of spontaneous autopolyploids because their progeny, when crossed with a normal ploidy parent, exhibit intermediate ploidies, resulting in reproductive abnormalities. However, there is limited knowledge of the causes of the second polar body retention in sturgeon culture. In this study, we report the results of experiments performed from 2015 to 2019 aimed at identifying the sources of spontaneous autopolyploidy in white sturgeon (Acipenser transmontanus) culture. In collaboration with several sturgeon farms, we tested whether post-ovulatory ageing, Mechanical Shock during egg de-adhesion, and the combined effects of both factors increased spontaneous autopolyploidy. To test the effect of post-ovulatory ageing, eggs were collected from females and either fertilized at the industry normative time (2–5 h post-oviposition) or stored in ovarian fluid at 15 °C for 6–8 h before fertilization. To test the effect of Mechanical Shock, eggs were collected, fertilized 2–5 h post-oviposition and exposed to either gentle or vigorous mixing during the 60 min de-adhesion treatment. Results from this work reveal that post-ovulatory ageing does increase the incidence of spontaneous autopolyploidy in some females, but overall the proportions produced were low (range 0–15%). Proportions of spontaneous autopolyploids in eggs exposed to vigorous mixing were also variable (1–92%) but significantly higher in 75% of the females when compared to their respective controls or gentle mixing treatments, indicating that Mechanical Shock during egg de-adhesion is likely the primary cause of spontaneous autopolyploidy. To our knowledge this is the first study to document Mechanical Shock to eggs during de-adhesion as a cause of abnormal ploidy in cultured fishes. We observed high variability in egg quality among females and a significant relationship between embryo mortality and the incidence of spontaneous autopolyploidy when eggs were exposed to Mechanical Shock. Repeated spawning of a female that produced a high proportion of spontaneous autopolyploids provided preliminary evidence that genetic background may influence the likelihood that a female's eggs will be prone to second polar body retention when subjected to Mechanical Shock. Although spontaneous autopolyploidy in sturgeon culture will likely never be eliminated entirely, we provide practical recommendations to sturgeon producers to reduce its incidence in a production setting

Aviva J Fiske - One of the best experts on this subject based on the ideXlab platform.

  • Mechanical Shock during egg de adhesion and post ovulatory ageing contribute to spontaneous autopolyploidy in white sturgeon culture acipenser transmontanus
    Aquaculture, 2020
    Co-Authors: Joel P Van Eenennaam, Aviva J Fiske, Michaiah J Leal, Chessie Cooleyrieders, Anne E Todgham, Fred S Conte, Andrea D Schreier
    Abstract:

    Abstract Spontaneous autopolyploidy, a 1.5x increase in genome size resulting from second polar body retention after fertilization, has been documented in cultured sturgeons, with the proportion of spontaneous autopolyploid progeny ranging widely among maternal families. Sturgeon farms wish to reduce the number of spontaneous autopolyploids because their progeny, when crossed with a normal ploidy parent, exhibit intermediate ploidies, resulting in reproductive abnormalities. However, there is limited knowledge of the causes of the second polar body retention in sturgeon culture. In this study, we report the results of experiments performed from 2015 to 2019 aimed at identifying the sources of spontaneous autopolyploidy in white sturgeon (Acipenser transmontanus) culture. In collaboration with several sturgeon farms, we tested whether post-ovulatory ageing, Mechanical Shock during egg de-adhesion, and the combined effects of both factors increased spontaneous autopolyploidy. To test the effect of post-ovulatory ageing, eggs were collected from females and either fertilized at the industry normative time (2–5 h post-oviposition) or stored in ovarian fluid at 15 °C for 6–8 h before fertilization. To test the effect of Mechanical Shock, eggs were collected, fertilized 2–5 h post-oviposition and exposed to either gentle or vigorous mixing during the 60 min de-adhesion treatment. Results from this work reveal that post-ovulatory ageing does increase the incidence of spontaneous autopolyploidy in some females, but overall the proportions produced were low (range 0–15%). Proportions of spontaneous autopolyploids in eggs exposed to vigorous mixing were also variable (1–92%) but significantly higher in 75% of the females when compared to their respective controls or gentle mixing treatments, indicating that Mechanical Shock during egg de-adhesion is likely the primary cause of spontaneous autopolyploidy. To our knowledge this is the first study to document Mechanical Shock to eggs during de-adhesion as a cause of abnormal ploidy in cultured fishes. We observed high variability in egg quality among females and a significant relationship between embryo mortality and the incidence of spontaneous autopolyploidy when eggs were exposed to Mechanical Shock. Repeated spawning of a female that produced a high proportion of spontaneous autopolyploids provided preliminary evidence that genetic background may influence the likelihood that a female's eggs will be prone to second polar body retention when subjected to Mechanical Shock. Although spontaneous autopolyploidy in sturgeon culture will likely never be eliminated entirely, we provide practical recommendations to sturgeon producers to reduce its incidence in a production setting.

  • Mechanical Shock during egg de-adhesion and post-ovulatory ageing contribute to spontaneous autopolyploidy in white sturgeon culture (Acipenser transmontanus)
    eScholarship University of California, 2020
    Co-Authors: Joel P Van Eenennaam, Aviva J Fiske, Anne E Todgham, Mj Leal, Cooley-rieders C, Fs Conte, Ad Schreie
    Abstract:

    © 2019 The Authors Spontaneous autopolyploidy, a 1.5x increase in genome size resulting from second polar body retention after fertilization, has been documented in cultured sturgeons, with the proportion of spontaneous autopolyploid progeny ranging widely among maternal families. Sturgeon farms wish to reduce the number of spontaneous autopolyploids because their progeny, when crossed with a normal ploidy parent, exhibit intermediate ploidies, resulting in reproductive abnormalities. However, there is limited knowledge of the causes of the second polar body retention in sturgeon culture. In this study, we report the results of experiments performed from 2015 to 2019 aimed at identifying the sources of spontaneous autopolyploidy in white sturgeon (Acipenser transmontanus) culture. In collaboration with several sturgeon farms, we tested whether post-ovulatory ageing, Mechanical Shock during egg de-adhesion, and the combined effects of both factors increased spontaneous autopolyploidy. To test the effect of post-ovulatory ageing, eggs were collected from females and either fertilized at the industry normative time (2–5 h post-oviposition) or stored in ovarian fluid at 15 °C for 6–8 h before fertilization. To test the effect of Mechanical Shock, eggs were collected, fertilized 2–5 h post-oviposition and exposed to either gentle or vigorous mixing during the 60 min de-adhesion treatment. Results from this work reveal that post-ovulatory ageing does increase the incidence of spontaneous autopolyploidy in some females, but overall the proportions produced were low (range 0–15%). Proportions of spontaneous autopolyploids in eggs exposed to vigorous mixing were also variable (1–92%) but significantly higher in 75% of the females when compared to their respective controls or gentle mixing treatments, indicating that Mechanical Shock during egg de-adhesion is likely the primary cause of spontaneous autopolyploidy. To our knowledge this is the first study to document Mechanical Shock to eggs during de-adhesion as a cause of abnormal ploidy in cultured fishes. We observed high variability in egg quality among females and a significant relationship between embryo mortality and the incidence of spontaneous autopolyploidy when eggs were exposed to Mechanical Shock. Repeated spawning of a female that produced a high proportion of spontaneous autopolyploids provided preliminary evidence that genetic background may influence the likelihood that a female's eggs will be prone to second polar body retention when subjected to Mechanical Shock. Although spontaneous autopolyploidy in sturgeon culture will likely never be eliminated entirely, we provide practical recommendations to sturgeon producers to reduce its incidence in a production setting