437 research outputs found
Response of arum lily calli to culture filtrate of Pectobacterium carotovorum subsp. carotovorum
This report demonstrated that culture filtrate of Pectobacterium carotovorum ssp. carotovorum isolate ZT0505, the pathogen of bacterial soft rot disease of arum lily (Zantedeschia sp.), contained extracellular enzymes and caused arum lily leaf tissue and callus maceration. Arum lily leaf tissue and callus sensitivity to culture filtrate coincided with the host susceptibility to the pathogen. The rates of survival of callus pieces were determined after exposure for various times to culture filtrate. Survival of callus pieces (%) increased with reduction of exposure time from 20 to 14 h and from 14 to 8 h. One out of 30 callus pieces was still viable after 3 cycles of 8 h exposure. Subsequently, the surviving cells in this callus pieces proliferated and differentiated into shoots. Based on this initial work, the callus screening using culture filtrate as selection agent may be useful for in vitro selection of soft rot resistant germplasm in arum lily
Reassessing values for emerging big data technologies: integrating design-based and application-based approaches
Through the exponential growth in digital devices and computational capabilities, big data technologies are putting pressure upon the boundaries of what can or cannot be considered acceptable from an ethical perspective. Much of the literature on ethical issues related to big data and big data technologies focuses on separate values such as privacy, human dignity, justice or autonomy. More holistic approaches, allowing a more comprehensive view and better balancing of values, usually focus on either a design-based approach, in which it is tried to implement values into the design of new technologies, or an application-based approach, in which it is tried to address the ways in which new technologies are used. Some integrated approaches do exist, but typically are more general in nature. This offers a broad scope of application, but may not always be tailored to the specific nature of big data related ethical issues. In this paper we distil a comprehensive set of ethical values from existing design-based and application-based ethical approaches for new technologies and further focus these values to the context of emerging big data technologies. A total of four value lists (from techno-moral values, value-sensitive design, anticipatory emerging technology ethics and biomedical ethics) were selected for this. The integrated list consists of a total of ten values: human welfare, autonomy, non-maleficence, justice, accountability, trustworthiness, privacy, dignity, solidarity and environmental welfare. Together, this set of values provides a comprehensive and in-depth overview of the values that are to be taken into account for emerging big data technologies.Horizon 2020(H2020)No 731873 (e-SIDES)Article / Letter to editorInstituut voor Metajuridic
Reassessing values for emerging big data technologies: integrating design-based and application-based approaches
Through the exponential growth in digital devices and computational capabilities, big data technologies are putting pressure upon the boundaries of what can or cannot be considered acceptable from an ethical perspective. Much of the literature on ethical issues related to big data and big data technologies focuses on separate values such as privacy, human dignity, justice or autonomy. More holistic approaches, allowing a more comprehensive view and better balancing of values, usually focus on either a design-based approach, in which it is tried to implement values into the design of new technologies, or an application-based approach, in which it is tried to address the ways in which new technologies are used. Some integrated approaches do exist, but typically are more general in nature. This offers a broad scope of application, but may not always be tailored to the specific nature of big data related ethical issues. In this paper we distil a comprehensive set of ethical values from existing design-based and application-based ethical approaches for new technologies and further focus these values to the context of emerging big data technologies. A total of four value lists (from techno-moral values, value-sensitive design, anticipatory emerging technology ethics and biomedical ethics) were selected for this. The integrated list consists of a total of ten values: human welfare, autonomy, non-maleficence, justice, accountability, trustworthiness, privacy, dignity, solidarity and environmental welfare. Together, this set of values provides a comprehensive and in-depth overview of the values that are to be taken into account for emerging big data technologies.Horizon 2020(H2020)No 731873 (e-SIDES)Article / Letter to editorInstituut voor Metajuridic
Magnetic-Field Induced Quantum Critical Point in YbRhSi
We report low-temperature calorimetric, magnetic and resistivity measurements
on the antiferromagnetic (AF) heavy-fermion metal YbRhSi ( 70
mK) as a function of magnetic field . While for fields exceeding the
critical value at which the low temperature resistivity
shows an dependence, a divergence of upon
reducing to suggests singular scattering at the whole Fermi
surface and a divergence of the heavy quasiparticle mass. The observations are
interpreted in terms of a new type of quantum critical point separating a
weakly AF ordered from a weakly polarized heavy Landau-Fermi liquid state.Comment: accepted for publication in Phys. Rev. Let
Scaling of the magnetic entropy and magnetization in YbRh_2(Si_{0.95}Ge_{0.05})_2
The magnetic entropy of YbRh_2(Si_{0.95}Ge_{0.05})_2 is derived from
low-temperature ( mK) specific heat measurements. Upon field-tuning
the system to its antiferromagnetic quantum critical point unique temperature
over magnetic field scaling is observed indicating the disintegration of heavy
quasiparticles. The field dependence of the entropy equals the temperature
dependence of the dc-magnetization as expected from the Maxwell relation. This
proves that the quantum-critical fluctuations affect the thermal and magnetic
properties in a consistent way.Comment: 6 pages, 2 figures, manuscript submitted to SCES2004 conferenc
Tuning Heavy Fermion Systems into Quantum Criticality by Magnetic Field
We discuss a series of thermodynamic, magnetic and electrical transport
experiments on the two heavy fermion compounds CeNi2Ge2 and YbRh2Si2 in which
magnetic fields, B, are used to tune the systems from a Non-Fermi liquid (NFL)
into a field-induced FL state. Upon approaching the quantum-critical points
from the FL side by reducing B we analyze the heavy quasiparticle (QP) mass and
QP-QP scattering cross sections. For CeNi2Ge2 the observed behavior agrees well
with the predictions of the spin-density wave (SDW) scenario for
three-dimensional (3D) critical spin-fluctuations. By contrast, the observed
singularity in YbRh2Si2 cannot be explained by the itinerant SDW theory for
neither 3D nor 2D critical spinfluctuations. Furthermore, we investigate the
magnetization M(B) at high magnetic fields. For CeNi2Ge2 a metamagnetic
transition is observed at 43 T, whereas for YbRh2Si2 a kink-like anomaly occurs
at 10 T in M vs B (applied along the easy basal plane) above which the heavy
fermion state is completely suppressed.Comment: 15 pages, 8 figures, submitted to Journal of Low Temperature Physics,
special Series on "High Magnetic Field Facilities
Divergence of the heavy quasiparticle mass at the antiferromagnetic quantum critical point in YbRh2Si2
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