Cavity QED determination of atomic number statistics in optical lattices

We study the reflection of two counter-propagating modes of the light field in a ring resonator by ultracold atoms either in the Mott insulator state or in the superfluid state of an optical lattice. We obtain exact numerical results for a simple two-well model and carry out statistical calculations appropriate for the full lattice case. We find that the dynamics of the reflected light strongly depends on both the lattice spacing and the state of the matter-wave field. Depending on the lattice spacing, the light field is sensitive to various density-density correlation functions of the atoms. The light field and the atoms become strongly entangled if the latter are in a superfluid state, in which case the photon statistics typically exhibit complicated multimodal structures.Comment: 10 pages revtex, 13 figure

Non-destructive cavity QED probe of Bloch oscillations in a gas of ultracold atoms

We describe a scheme for probing a gas of ultracold atoms trapped in an optical lattice and moving in the presence of an external potential. The probe is non-destructive and uses the existing lattice fields as the measurement device. Two counter-propagating cavity fields simultaneously set up a conservative lattice potential and a weak quantum probe of the atomic motion. Balanced heterodyne detection of the probe field at the cavity output along with integration in time and across the atomic cloud yield information about the atomic dynamics in a single run. The scheme is applied to a measurement of the Bloch oscillation frequency for atoms moving in the presence of the local gravitational potential. Signal-to-noise ratios are estimated to be as high as $10^4$.Comment: 8 pages, 6 figures, submitted to Phys. Rev.

Design and Fabrication of Three-Dimensional Scaffolds for Tissue Engineering of Human Heart Valves

We developed a new fabrication technique for 3-dimensional scaffolds for tissue engineering of human heart valve tissue. A human aortic homograft was scanned with an X-ray computer tomograph. The data derived from the X-ray computed tomogram were processed by a computer-aided design program to reconstruct a human heart valve 3-dimensionally. Based on this stereolithographic model, a silicone valve model resembling a human aortic valve was generated. By taking advantage of the thermoplastic properties of polyglycolic acid as scaffold material, we molded a 3-dimensional scaffold for tissue engineering of human heart valves. The valve scaffold showed a deviation of only +/- 3-4% in height, length and inner diameter compared with the homograft. The newly developed technique allows fabricating custom-made, patient-specific polymeric cardiovascular scaffolds for tissue engineering without requiring any suture materials. Copyright (c) 2008 S. Karger AG, Base

Portrayal of psychiatric genetics in Australian print news media, 1996-2009

Objective: To investigate how Australian print news media portray psychiatric genetics. Design and setting: Content and framing analysis of a structured sample of print news items about psychiatric genetics published in Australian newspapers between 1996 and 2009. Main outcome measures: Identify dominant discourses about aetiology of mental illness, and perceived clinical outcomes and implications of psychiatric genetics research. Results: We analysed 406 eligible items about the genetics of psychiatric disorders. News coverage of psychiatric genetics has steadily increased since 1996. Items attributing the aetiology of psychiatric disorders to gene-environment interactions (51%) outnumbered items attributing only genetic (30%) or only environmental factors (20%). Of items that referred to heritability of mental illness, frames of genetic determinism (78%) occurred more frequently than probabilistic frames (22%). Of frames related to genetic prophesy, genetic optimism frames (78%) were used more frequently than frames of genetic pessimism (22%). Psychosocial and ethical implications of psychiatric genetics received comparatively relatively little coverage (23%). The analysis identified 22 predictions about psychiatric genetic discoveries and the availability of molecular-based interventions in psychiatry, most of which (20/ 22, 91%) failed to manifest by the predicted year. Conclusions: Excessive optimism about the power of genetic technology in psychiatric health care, perceived clinical benefits, and largely unfulfilled predictions about availability of these benefits could encourage unrealistic expectations about future molecular-based treatment options for mental health

Active optical clock based on four-level quantum system

Active optical clock, a new conception of atomic clock, has been proposed recently. In this report, we propose a scheme of active optical clock based on four-level quantum system. The final accuracy and stability of two-level quantum system are limited by second-order Doppler shift of thermal atomic beam. To three-level quantum system, they are mainly limited by light shift of pumping laser field. These limitations can be avoided effectively by applying the scheme proposed here. Rubidium atom four-level quantum system, as a typical example, is discussed in this paper. The population inversion between $6S_{1/2}$ and $5P_{3/2}$ states can be built up at a time scale of $10^{-6}$s. With the mechanism of active optical clock, in which the cavity mode linewidth is much wider than that of the laser gain profile, it can output a laser with quantum-limited linewidth narrower than 1 Hz in theory. An experimental configuration is designed to realize this active optical clock.Comment: 5 page

Exploration of decision-making regarding the transfer of mosaic embryos following preimplantation genetic testing: A qualitative study

STUDY QUESTION: What are patients' reasoning and decisional needs in relation to the transfer of mosaic embryos following preimplantation genetic testing (PGT)? SUMMARY ANSWER: This study identified four themes, which were patients' reasoning behind decision-making, their decisional needs, the influence of the mosaic embryos on the decision-making and the role of health professionals. WHAT IS KNOWN ALREADY: To date, no study has investigated the reasoning of patients behind their decision-making and the influence of mosaic embryos. STUDY DESIGN, SIZE, DURATION: This is a cross-sectional study using a qualitative approach. Twenty participants were interviewed, and recruitment was ceased when no new information was identified in the data analysis. It ensured a sufficient sample size for a qualitative study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were females with mosaic embryos. Semi-structured in-depth interviews were conducted via telephone. MAIN RESULTS AND THE ROLE OF CHANCE: Four themes were identified: Reasoning behind decision-making, decisional needs, influence of mosaic embryos on decision-making and the role of health professionals. Potential risks of transferring mosaic embryos and prioritization of euploid embryos were the main reasons for not transferring mosaic embryos. A lack of alternatives, perceived benefits and risk tolerance were main reasons for transferring mosaic embryos. Patients reported that information on mosaic embryos, amniocentesis and termination was important to support their decision-making. Unmet needs relating to healthcare services and social support were reported. In addition, having mosaic embryos affected the patients' emotional and behavioural responses, discussions about prenatal testing, attitudes to termination and further IVF cycles and attitudes towards PGT. Health professionals were found to influence the patients' decision-making. LIMITATIONS, REASONS FOR CAUTION: Participants were recruited through one clinic, which may limit the transferability of results. Also, patients' experiences in relation to financial aspects of PGT may not be relevant to other jurisdictions due to different healthcare policies. WIDER IMPLICATIONS OF THE FINDINGS: The results may inform how clinicians provide healthcare services based on factors influencing patients' decision-making. Health professionals should be aware of the influence their attitudes can have on patients' decision-making and should present information accordingly. Also, providing all relevant information may help to facilitate informed decision-making. Provision of psychological support from professionals and support groups is also critical during the process of testing and transfer. Patients have educational needs regarding mosaic embryos, and educational resources including decision aids in plain language are needed. STUDY FUNDING/COMPETING INTEREST(S): B.M. was funded through a Senior Research Fellowship Level B (ID 1078523) from the National Health and Medical Research Council of Australia. L.C. was supported by a University International Postgraduate Award under the Australian Government Research Training Program (RTP) scholarship. No other funding was received for this study. The authors report no competing interests. TRIAL REGISTRATION NUMBER: N/A

Factors influencing patients’ decision-making about preimplantation genetic testing for monogenic disorders

STUDY QUESTION: What are the roles of individual and interpersonal factors in couples’ decision-making regarding preimplantation genetic testing for monogenic disorders (PGT-M)? SUMMARY ANSWER: Couples’ decision-making regarding PGT-M was associated with individual and interpersonal factors, that is the perceived consistency of information received, satisfaction with information, self-efficacy (individuals’ beliefs in their ability to make decisions), actual knowledge about PGT-M and social support from the partner. WHAT IS KNOWN ALREADY: Various factors have been shown to be associated with decision-making regarding PGT-M. However, PGT-M is experienced at an individual level, and to date, no studies have investigated the roles of the above-mentioned individual and interpersonal factors. STUDY DESIGN, SIZE, DURATION: This is a cross-sectional study with 279 participants. Participants were recruited through IVFAustralia, Sydney Children’s Hospital and support groups from May 2020 to November 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were women who had undergone or were considering PGT-M and their partners. Participants were recruited through IVFAustralia, Sydney Children’s Hospital and support groups to complete online questionnaires. Decisional regret, decisional satisfaction and decisional conflict were measured as outcome variables. Multiple linear regressions were performed to examine the association between factors and outcome variables. Mann–Whitney U tests were performed to test the differences between participants who had undergone PGT-M and those who were considering PGT-M. MAIN RESULTS AND THE ROLE OF CHANCE: For couples who had undergone PGT-M, decisional regret was significantly negatively associated with perceived consistency of information received (b = -0.26, P < 0.01), self-efficacy (b = -0.25, P < 0.01) and actual knowledge about PGT-M (b = -0.30, P < 0.001), while decisional satisfaction had positive association with satisfaction with information received (b = 0.37, P < 0.001) and self-efficacy (b = 0.24, P < 0.05). For couples who were considering PGT-M, decisional conflict was negatively associated with satisfaction with information received (b = -0.56, P < 0.001). For females who had undergone PGT-M, decisional regret was negatively associated with social support from the partner (b = -0.35, P < 0.05) in addition to perceived consistency of information received (b = -0.24, P < 0.05). In this group, decisional satisfaction was positively associated with women’s satisfaction with the information received (b = 0.34, P < 0.01), social support from the partner (b = 0.26, P < 0.05) and self-efficacy (b = 0.25, P < 0.05). For females who were considering PGT-M, decisional conflict was negatively associated with satisfaction with the information received (b = -0.43, P < 0.01) and social support from the partner (b = -0.30, P < 0.05). This study also identified those aspects of PGT-M that couples felt most concerned about in relation to their decision-making, in particular safety issues such as short- or long-term health problems for the baby and potential harms to the embryos and the mother’s health. The likelihood of getting pregnant and having a baby with a genetic condition being tested for were also important in couples’ decision-making. LIMITATIONS, REASONS FOR CAUTION: This study assessed the concerns of couples about having a baby with a variety of genetic conditions. However, condition-specific issues might not be covered. Furthermore, social support from the partner was assessed among females only. Male participants’ perceived social support from their partner and the association between mutual support and decision-making were not assessed due to the absence of dyadic data. WIDER IMPLICATIONS OF THE FINDINGS: Results highlight the importance of effective patient education on PGT-M and the need to provide high-quality and consistent information in the context of patient-centred care. Patients are likely to benefit from information that addresses their specific concerns in relation to PGT-M. From females’ perspective, support from partners is essential, and partners should, therefore, be encouraged to participate in all stages of the decision-making process. Suggestions for future studies were made