Reproductive immunology in viviparous mammals: evolutionary paradox of interactions among immune mechanisms and autologous or allogeneic gametes and semiallogeneic foetuses.

Literally, reproductive immunology was born in bovine on-farm reproduction where seminal experiments intended for developing methods for embryo transfer in cattle were performed. Actually, these experiments led to two of major concepts and fundamental principles of reproductive immunology using the bovine species as a model for biomedical research, namely the concept of acquired immunological tolerance and the paradox of the semiallogeneic bovine foetus whereby such organism can develop within an immunologically competent host. Peter Medawar, a scientist who together with Frank Macfarlande Burnet shared the 1960 Nobel Prize in physiology or medicine for discovery of acquired immunological tolerance, while studying dizygotic cattle twins, thereby giving birth to reproductive immunology. Also, these findings significantly influenced development of organ transplants and showed that using farm animals as models for studying transplantation immunology had general relevance for mammalian biology and health including those of humans. However, the interest for further research of the fascinating maternal immune influences on pregnancy and perinatal outcomes and of the prevention and treatment of immunologically mediated reproductive disorders in viviparous mammals of veterinary relevance by veterinary immunologists and reproductive clinicians have been very scarce regarding the application of nonspecific immunomodulatory agents for prevention and treatment of subfertility and infertility in pigs and cattle, but still broadening knowledge in this area and hold great potential for improving such therapy in the future. The aim of the current overview is to provide up-to-date information and explaining/translating relevant immunology phenomena into veterinary practice for specialists and scientists/clinicians in reproduction of animals.

Linking the rotation of a rigid body to the Schrödinger equation: The quantum tennis racket effect and beyond.

The design of efficient and robust pulse sequences is a fundamental requirement in quantum control. Numerical methods can be used for this purpose, but with relatively little insight into the control mechanism. Here, we show that the free rotation of a classical rigid body plays a fundamental role in the control of two-level quantum systems by means of external electromagnetic pulses. For a state to state transfer, we derive a family of control fields depending upon two free parameters, which allow us to adjust the efficiency, the time and the robustness of the control process. As an illustrative example, we consider the quantum analog of the tennis racket effect, which is a geometric property of any classical rigid body. This effect is demonstrated experimentally for the control of a spin 1/2 particle by using techniques of Nuclear Magnetic Resonance. We also show that the dynamics of a rigid body can be used to implement one-qubit quantum gates. In particular, non-adiabatic geometric quantum phase gates can be realized based on the Montgomery phase of a rigid body. The robustness issue of the gates is discussed.

GRIN VII: gradient-index optical imaging systems.

The Seventh Topical Meeting on Gradient-Index Optical Imaging Systems was held in Reno, NV, 15-16 Jan. 1987. A profile of the papers presented at that meeting and those published in this issue (1 Feb. 1988) is given.

Helping the young stroke victim.

Cerebrovascular accidents, or strokes, are a major source of disability; some 500,000 new cases are diagnosed annually. Though the number of young stroke victims is small, the cost in medical expenses and human suffering can be staggering. Causes of stroke are explained and information concerning survival rates, recovery, and rehabilitation is presented. Contributions to the integration and acceptance of the young stroke survivor by administrators, counselors, students, teachers, and school nurses are examined.

Correction of chromatic aberrations in GRIN endoscopes.

A gradient-index (GRIN) endoscope can be constructed by substituting for the usual objective and relay sections suitable cylindrical index-distribution rod lenses. Currently available GRIN lenses exhibit large amounts of chromatic aberration. Axial color arises mostly from the relay lens, while lateral color is due to the objective lens. A negative lens cemented to a shortened GRIN relay lens can simultaneously correct axial and lateral chromatic aberrations with commercially available components. This correction system reduces the requirements for mechanical centration better than do color correctors that are incorporated into the ocular design. Monochromatic aberrations are also considered.

Real-time phase microscopy using a phase-lock interferometer.

A phase-lock interference microscope (PLIM) has been designed and constructed. The instrument measures optical phase in real time with analog output voltages proportional to phase and position. The PLIM has been used to measure gradient index profiles in optical fibers, wall thicknesses of microballoons for laser induced fusion, the phase of biological specimens, and the surface finish of optical surfaces. The peak-to-peak noise of the instrument is lambda/50.