Extended Rotational Coherence of Polar Molecules in an Elliptically Polarized Trap.

We demonstrate long rotational coherence of individual polar molecules in the motional ground state of an optical trap. In the present, previously unexplored regime, the rotational eigenstates of molecules are dominantly quantized by trapping light rather than static fields, and the main source of decoherence is differential light shift. In an optical tweezer array of NaCs molecules, we achieve a three-orders-of-magnitude reduction in differential light shift by changing the trap's polarization from linear to a specific "magic" ellipticity. With spin-echo pulses, we measure a rotational coherence time of 62(3) ms (one pulse) and 250(40) ms (up to 72 pulses), surpassing the projected duration of resonant dipole-dipole entangling gates by orders of magnitude.

Assembly of a Rovibrational Ground State Molecule in an Optical Tweezer.

We demonstrate the coherent creation of a single NaCs molecule in its rotational, vibrational, and electronic (rovibronic) ground state in an optical tweezer. Starting with a weakly bound Feshbach molecule, we locate a two-photon transition via the |c^{3}Σ_{1},v^{'}=26⟩ excited state and drive coherent Rabi oscillations between the Feshbach state and a single hyperfine level of the NaCs rovibronic ground state |X^{1}Σ,v^{''}=0,N^{''}=0⟩ with a binding energy of D_{0}=h×147044.63(11) GHz. We measure a lifetime of 3.4±1.6 s for the rovibronic ground state molecule, which possesses a large molecule-frame dipole moment of 4.6D and occupies predominantly the motional ground state. These long-lived, fully quantum-state-controlled individual dipolar molecules provide a key resource for molecule-based quantum simulation and information processing.

Forming a Single Molecule by Magnetoassociation in an Optical Tweezer.

We demonstrate the formation of a single NaCs molecule in an optical tweezer by magnetoassociation through an s-wave Feshbach resonance at 864.11(5) G. Starting from single atoms cooled to their motional ground states, we achieve conversion efficiencies of 47(1)%, and measure a molecular lifetime of 4.7(7) ms. By construction, the single molecules are predominantly [77(5)%] in the center-of-mass motional ground state of the tweezer. Furthermore, we produce a single p-wave molecule near 807 G by first preparing one of the atoms with one quantum of motional excitation. Our creation of a single weakly bound molecule in a designated internal state in the motional ground state of an optical tweezer is a crucial step towards coherent control of single molecules in optical tweezer arrays.

Spatially-resolved luminescence and crystal structure of single core-shell nanowires measured in the as-grown geometry.

We report on the direct correlation between the structural and optical properties of single, as-grown core-multi-shell GaAs/In0.15Ga0.85As/GaAs/AlAs/GaAs nanowires. Fabricated by molecular beam epitaxy on a pre-patterned Si(111) substrate, on a row of well separated nucleation sites, it was possible to access individual nanowires in the as-grown geometry. The polytype distribution along the growth axis of the nanowires was revealed by synchrotron-based nanoprobe x-ray diffraction techniques monitoring the axial 111 Bragg reflection. For the same nanowires, the spatially-resolved emission properties were obtained by cathodoluminescence hyperspectral linescans in a scanning electron microscope. Correlating both measurements, we reveal a blueshift of the shell quantum well emission energy combined with an increased emission intensity for segments exhibiting a mixed structure of alternating wurtzite and zincblende stacking compared with the pure crystal polytypes. The presence of this mixed structure was independently confirmed by cross-sectional transmission electron microscopy.

Bandage soft contact lens barrier function: a clinical research note.

Corneal thickness pre- and post-operatively was measured on 18 volunteer subjects within the context of a clinical investigation of laser refractive surgery. All measurements were taken with regard for time of day, in order to counter any complicating diurnal influence on data accuracy. Of the 18 subjects, six lost or had accidently displaced their overnight bandage soft contact lenses the first night immediately after surgery, and 12 retained theirs. The individuals with lost bandage lenses exhibited uniformly thick, swollen corneas. In contrast, the other 12 subjects, with retained lenses, exhibited a stable corneal thickness map, displaying the characteristic relatively thick periphery that transitions to a thinner central region. Moreover, in the six affected subjects, application of a new overnight bandage lens resulted in recovery of the normal thickness pattern on day 2, as opposed to the uniform swelling or oedema of the previous day. In combination, these findings indicate a fluid barrier function on behalf of the bandage soft contact lenses, which allowed the corneal endothelial pump mechanism to counteract any extreme swelling or fluid accumulation. This previously unreported phenomenon helps explain the historical effectiveness of this treatment regimen for corneal bullous, or excessive fluid-retention, conditions.

Assistive technology and learning disabilities: today's realities and tomorrow's promises.

Many forms of technology, both "high" and "low," can help individuals with learning disabilities capitalize on their strengths and bypass, or compensate for, their disabilities. This article surveys the current status of assistive technology for this population and reflects on future promises and potential problems. In addition, a model is presented for conceptualizing assistive technology in terms of the types of barriers it helps persons with disabilities to surmount. Several current technologies are described and the research supporting their effectiveness reviewed: word processing, computer-based instruction in reading and other academic areas, interactive videodisc interventions for math, and technologies for daily life. In conclusion, three themes related to the future success of assistive technology applications are discussed: equity of access to technology; ease of technology, use; and emergent technologies, such as virtual reality.

Educational services for children with chronic illnesses: perspectives of educators and families.

Two parallel studies examined schools' and families' perceptions of the needs of children with chronic illnesses. Samples of 80 California school districts and 72 families were interviewed regarding types of chronic illnesses and school services, perceptions of and barriers to services, strategies for overcoming barriers, and fears and concerns of children with chronic illnesses. Most students were served in regular classes or at home. The most common barriers named by districts were funding and lack of public and staff awareness. Barriers named by families included teachers' misunderstanding of the child's needs and misinformation about the illness. Families focused on social-emotional issues and the impact of illness on their child's life; districts emphasized school absences and falling behind in schoolwork.

Neonatal cleft lip repair in Ayrshire; a contribution to the debate.

Neonatal cleft lip repair has been the normal practice in Ayrshire, Scotland, for the last 10 years. The surgical results are briefly presented. Anaesthetic and paediatric considerations are discussed. Assuming careful preoperative assessment is made, the procedure carries minimal morbidity, can give good results and is believed to offer distinct advantages to the parents and child.

Assessment of a scavenging device for use in paediatric anaesthesia.

We describe a scavenging device, primarily for use during inhalation induction of anaesthesia in children; it was designed to optimize the often conflicting requirements of clinical acceptability and adequate gas collection. The performance was assessed in three ways. The device reduced the nitrous oxide concentration in the breathing zone of the anaesthetist during inhalation induction to about 100 p.p.m. We also describe a method to measure the direct catchment of nitrous oxide expressed as a percentage of the total nitrous oxide used. In 46 patients the mean percentage collection was 82%. Using personal sampling devices, we found that comprehensive scavenging in paediatric anaesthesia can reduce the average exposure of anaesthetists to about 130 p.p.m. of nitrous oxide.

The Ruben circle anaesthesia system. An investigation of reverse flow of patient expired gas during spontaneous breathing.

The Ruben circle anaesthesia system was studied in the spontaneous breathing mode, and under certain conditions there was incompetence of the replaceable mushroom control valve. This causes a reverse flow of gas which results in rebreathing of expired gas when the system is used on spontaneously breathing patients. A patient simulator was used to investigate the way in which the reverse flow of gas depends on ventilatory parameters and fresh gas flow. The inspired concentration of carbon dioxide increased for increased fresh gas flow and for decreased tidal volume. These results were confirmed by observations on anaesthetised adult and paediatric patients during spontaneous breathing. We conclude that the system in its present form, is not suitable for use on spontaneously breathing paediatric patients.

Assessment of the presence of cytomegalovirus-neutralizing antibody by a plaque-reduction assay.

Evaluation of the in vitro neutralizing activity of 30 immunoglobulin G (IgG) preparations and seven batches of pooled plasma against human cytomegalovirus (CMV) was performed by plaque-reduction assays. There were definite differences detected by these methods that could permit the selection of preparations with highest titers for clinical trials. The addition of guinea pig complement to the plaque-reduction assay enhanced inhibition of CMV; thus, guinea pig complement should be used in assays of IgG preparations. There was no relationship between the ELISA-derived optical density values of the IgG samples and the titers determined by plaque neutralization. These data suggest that the results of plaque-reduction neutralization assays provide important information about preparations of antibody that may be selected for patient administration. The preparations selected for their high titers by neutralization assays differ significantly from those identified by another method.

Halothane hepatitis in a young child.

A 4-year-old girl developed severe hepatitis following the fourth administration of halothane in a period of 5 months. She was shown to have a circulating antibody which acted specifically against rabbit hepatocyte previously sensitized to halothane. The patient made a full recovery from the hepatitis, but 5 months later, developed diabetes mellitus.

Avian reticuloendotheliosis virus: identification of the hematopoietic target cell for transformation.

Non-virus-producing hematopoietic cells transformed in vitro by reticuloendotheliosis virus (REV-T) induce lethal "reticuloendotheliosis" when inoculated into histocompatible chickens. This is the first direct demonstration that an in vivo target cell of an avian acute leukemia virus can be transformed in vitro. The tumorigenic, REV-T-transformed non-virus-producing cells fail to express helper-virus-coded proteins. REV-T transformed tumorigenic cells therefore do not require helper-virus functions. Cells transformed in vivo or in vitro by REV-T have lymphoblastoid morphology and express low levels of terminal-deoxynucleotidyl-transferase activity and bursal-cell determinants. One clone synthesized Ig mu. The preferred target cells for REV-T transformation are therefore immature lymphoid cells that express B-cell determinants. We propose that the unique transforming sequence of REV-T be designated rel (lymphoid).

Characteristics of rheumatoid arthritis in a male population.

A population of males and females with definite or classical rheumatoid arthritis was studied. The males seem to have more severe disease with positive latex fixation, radiographic changes and rheumatoid nodules than is reported in the literature and the female comparison population. This difference can probably be explained because most studies have a female preponderance and our experience suggests that the disease is more severe in males.