48 research outputs found
Tailoring laser pulses with spectral and fluence constraints using optimal control theory
Within the framework of optimal control theory we develop a simple iterative
scheme to determine optimal laser pulses with spectral and fluence constraints.
The algorithm is applied to a one-dimensional asymmetric double well where the
control target is to transfer a particle from the ground state, located in the
left well, to the first excited state, located in the right well. Extremely
high occupations of the first excited state are obtained for a variety of
spectral and/or energetic constraints. Even for the extreme case where no
resonance frequency is allowed in the pulse the algorithm achieves an
occupation of almost 100%
Formation and interactions of cold and ultracold molecules: new challenges for interdisciplinary physics
Progress on researches in the field of molecules at cold and ultracold
temperatures is reported in this review. It covers extensively the experimental
methods to produce, detect and characterize cold and ultracold molecules
including association of ultracold atoms, deceleration by external fields and
kinematic cooling. Confinement of molecules in different kinds of traps is also
discussed. The basic theoretical issues related to the knowledge of the
molecular structure, the atom-molecule and molecule-molecule mutual
interactions, and to their possible manipulation and control with external
fields, are reviewed. A short discussion on the broad area of applications
completes the review.Comment: to appear in Reports on Progress in Physic
The 3′-Terminal Hexamer Sequence of Classical swine fever virus RNA Plays a Role in Negatively Regulating the IRES-Mediated Translation
The 3′ untranslated region (UTR) is usually involved in the switch of the translation and replication for a positive-sense RNA virus. To understand the 3′ UTR involved in an internal ribosome entry site (IRES)-mediated translation in Classical swine fever virus (CSFV), we first confirmed the predicted secondary structure (designated as SLI, SLII, SLIII, and SLIV) by enzymatic probing. Using a reporter assay in which the luciferase expression is under the control of CSFV 5′ and 3′ UTRs, we found that the 3′ UTR harbors the positive and negative regulatory elements for translational control. Unlike other stem loops, SLI acts as a repressor for expression of the reporter gene. The negative cis-acting element in SLI is further mapped to the very 3′-end hexamer CGGCCC sequence. Further, the CSFV IRES-mediated translation can be enhanced by the heterologous 3′-ends such as the poly(A) or the 3′ UTR of Hepatitis C virus (HCV). Interestingly, such an enhancement was repressed by flanking this hexamer to the end of poly(A) or HCV 3′ UTR. After sequence comparison and alignment, we have found that this hexamer sequence could hypothetically base pair with the sequence in the IRES IIId1, the 40 S ribosomal subunit binding site for the translational initiation, located at the 5′ UTR. In conclusion, we have found that the 3′-end terminal sequence can play a role in regulating the translation of CSFV
Application of optical flow methods to aerated skimming flows above triangular and trapezoidal step cavities
The Alienated Human
Man and nature is a unity between body and individual in behavior. Humans are liberty, creative, happy subjects in behavior and labor. By behavior and labor, humans produce tools, spare parts, machines, and robots to replace internal organs, lengthen the senses, and lengthen defective body parts. Evolution is no longer a mutation in the body but the assembly of accessories into organs, senses, and body parts when needed. People use devices that are manufactured to be used for what people want depending on specific conditions and circumstances. Labor and behavior make objectification of people, but alienated behavior and alienated labor make humanize the object. The time to enjoy liberty, creativity, and happiness is human, and the time to perform alienated behavior and alienated labor is the time to live for the non-human. People are corrupted into slavery to standards, money. It is the process of self-torture, torturing oneself; and the nobility of standards, the wealth of money is the unhappy product of life. Humans are liberty, creative and happy subjects; alienated human beings are all helpless, unhappy, deceit. Money, standards are products of helplessness, unhappiness, lies. Standards, money remove people from life