DUST POLARIZATION IN PROTOPLANETARY DISKS: EVIDENCE FOR MULTIPLE MECHANISMS AT WORK

The surfaces of astronomical dust grains are a crucial site for chemical reactions. Observations of polarized emission from dust grains provide a powerful tool for investigating the sizes and distribution of dust grains in protoplanetary disks. We present ALMA observations of three protostellar disks at 3 mm and 870 $\mu$m: Haro 6-13, RY Tau, and MWC 480. At 870 $\mu$m, all three disks show polarization morphologies consistent with those produced by self-scattering. At 3 mm, Haro 6-13 shows a polarization morphology that may indicate radiative or mechanical alignment of grains, while RY Tau and MWC 480 still show polarization patterns that are consistent with scattering. Additionally, we present models of the polarization patterns different polarization mechanisms would be expected to produce in these disks

MAGNETIC FIELDS IN PROTOPLANETARY DISKS: NEW LIMITS FROM ZEEMAN SPLITTING OBSERVATIONS

Magnetic fields are thought to play a crucial role in the formation and evolution of protoplanetary disks by providing a means of angular momentum transport through the magnetorotational instability and/or magnetically driven winds. However, finding observational evidence for the presence of magnetic fields in disks has proven difficult. Zeeman splitting observations offer a way to directly measure or put upper limits on line-of-sight magnetic field strengths in astronomical sources, as the circularly polarized signal produced by Zeeman splitting depends directly on the magnetic field strength along the line of sight. We present the results of ALMA observations of the CN 2-1 line in two disks: AS 209 and V4046 Sgr. The upper limits on net line-of-sight magnetic field strengths derived from these observations and their implications for the overall disk magnetic field strength and morphology will be discussed

DUST POLARIZATION IN THREE PROTOSTELLAR DISKS

We present 1.3 mm ALMA dust polarization observations of three T Tauri stars: DG Tauri, DL Tauri, and LkCA 15. All three sources show some degree of polarization at a resolution of ~0.5". DL Tauri shows a polarization morphology that is consistent with polarization produced by dust scattering. DG Tauri and LkCa 15 have polarization morphologies that may be produced by dust grain alignment with the disk's radiation field and/or magnetic field. Dust grains can serve as a site for chemical reactions in protostellar disks. Observations of dust polarization can constrain the distribution and properties of dust within the disk, which would provide insight into the chemical evolution of protostellar disks

Human factors and data logging processes with the use of advanced technology for adults with type 1 diabetes (T1DM): A systematic integrative review

Background: People with T1DM are confronted with self-management tasks and strategies to reduce risks of long-term complications against the risk of hypoglycemic events. The potential of advanced and evolving technology to address these issues involves consideration of psychological and behavioral constructs alongside the usability of devices. Access and uptake of advanced technology is further influenced by economic factors and health care provider capacity to support such interventions. Previous reviews have focused upon either clinical outcomes or descriptively scoped the literature or have synthesized studies on adults with children and young people where human factors are different. Objective: The objective of this review was to describe the relationship between human factors and adherence with technology for data logging processes in adults (> 18 years) with T1DM and to explore the factors which influence this association. Methods: A systematic literature review. Results: 18 studies were included in the review following a literature search using the PRISMA guidelines and a quality appraisal process. This included 3320 participants with a mean age of 42 years. Overall, adults felt more satisfied with their treatment on transition to advanced technology (insulin pump and CGM), the most significant contributing factor was when BG levels were consistently < 7.00mmol/l (P =.009). However, participants spent considerable time on their diabetes self-care. There was evidence that logging of data was positively correlated with increasing age with the use of an app that provided meaningful feedback (regression coefficient = 55.8 recordings/ year; P = 0.009). Furthermore, there were benefits of CGM use for older adults in mediating complexities and their fears of hypoglycemia with reported significant differences in well-being (P= .009). Qualitative studies within the review aimed to explore the use and uptake of technology within the context of everyday lives. Participants experienced ‘frustrations’ with CGM, CSII, calibration of devices and alarms. In addition, there were implications for ‘body image’ when carrying and using a device. This takes into account wide variations in individual use and interaction with technology across a continuum of sociocultural contexts. This has implications for the way in which future technologies are designed. Conclusions: Many of the quantitative studies in the review were limited by small sample sizes. This may make it difficult to generalize findings to other contexts. This is further limited by a sample that was predominantly Caucasian, well-controlled and engaged with their self-care. However, the use of critical appraisal frameworks has highlighted areas where research into human factors and data logging processes of individuals could be improved. This includes engaging people in the design of the technology, and further exploration of the way in which significant others impact on the behavior and attitude of the individual towards technology use

ALMA CN Zeeman Observations of AS 209: Limits on Magnetic Field Strength and Magnetically Driven Accretion Rate

While magnetic fields likely play an important role in driving the evolution of protoplanetary disks through angular momentum transport, observational evidence of magnetic fields has only been found in a small number of disks. Although dust continuum linear polarization has been detected in an increasing number of disks, its pattern is more consistent with that from dust scattering than from magnetically aligned grains in the vast majority of cases. Continuum linear polarization from dust grains aligned to a magnetic field can reveal information about the magnetic field´s direction, but not its strength. On the other hand, observations of circular polarization in molecular lines produced by Zeeman splitting offer a direct measure of the line-of-sight magnetic field strength in disks. We present upper limits on the net toroidal and vertical magnetic field strengths in the protoplanetary disk AS 209 derived from Zeeman splitting observations of the CN 2-1 line. The 3σ upper limit on the net line-of-sight magnetic field strength in AS 209 is 5.0 mG on the redshifted side of the disk and 4.2 mG on the blueshifted side of the disk. Given the disk´s inclination angle, we set a 3σ upper limit on the net toroidal magnetic field strength of 8.7 and 7.3 mG for the red and blue sides of the disk, respectively, and 6.2 and 5.2 mG on the net vertical magnetic field on the red and blue sides of the disk. If magnetic disk winds are a significant mechanism of angular momentum transport in the disk, magnetic fields of a strength close to the upper limits would be sufficient to drive accretion at the rate previously inferred for regions near the protostar.Fil: Harrison, Rachel. University of Illinois at Urbana; Estados UnidosFil: Looney, L. W.. University of Illinois at Urbana; Estados UnidosFil: Stephens, I. W.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Li, Z.-Y.. University of Virginia; Estados UnidosFil: Teague, Richard. Department Of Astronomy; Estados UnidosFil: Crutcher, Richard. University of Illinois at Urbana; Estados UnidosFil: Yang, H.. Tsinghua University; ChinaFil: Cox, E. G.. Northwestern University; Estados UnidosFil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Shinnaga, H.. Kagoshima University; Japó

Cyclotron resonance in the layered perovskite superconductor Sr2RuO4

We report a detailed study of the magnetic-field-orientation dependence of the millimetre-wave magnetoconductivity of the superconductor Sr2RuO4 We find two harmonic series of cyclotron resonances. We assign the first, corresponding to a quasiparticle mass of $4.29 \pm 0.05 m_{\rm e}$, where $m_{\rm e}$ is the free-electron mass, to the $\beta$ Fermi-surface section. We assign the second series, which contains only odd harmonics, to cyclotron resonance of the $\gamma$ Fermi-surface section, yielding a quasiparticle mass of $12.35 \pm 0.20 m_{\rm e}$. A third, single cyclotron resonance, corresponding to a quasiparticle mass of $5.60 \pm 0.03 m_{\rm e}$, is attributed to the $\alpha$ Fermi-surface section. In addition, we find a very strong absorption mode in the presence of a magnetic field component parallel to the quasi-two-dimensional planes of the sample. Its dependence on the orientation of the magnetic field cannot be described in the context of conventional cyclotron resonance, and the origin of this mode is not yet clear.Comment: Submitted to J. Phys. Cond. Ma

Maximising response to postal questionnaires – A systematic review of randomised trials in health research

Background Postal self-completion questionnaires offer one of the least expensive modes of collecting patient based outcomes in health care research. The purpose of this review is to assess the efficacy of methods of increasing response to postal questionnaires in health care studies on patient populations. Methods The following databases were searched: Medline, Embase, CENTRAL, CDSR, PsycINFO, NRR and ZETOC. Reference lists of relevant reviews and relevant journals were hand searched. Inclusion criteria were randomised trials of strategies to improve questionnaire response in health care research on patient populations. Response rate was defined as the percentage of questionnaires returned after all follow-up efforts. Study quality was assessed by two independent reviewers. The Mantel-Haenszel method was used to calculate the pooled odds ratios. Results Thirteen studies reporting fifteen trials were included. Implementation of reminder letters and telephone contact had the most significant effect on response rates (odds ratio 3.7, 95% confidence interval 2.30 to 5.97 p = <0.00001). Shorter questionnaires also improved response rates to a lesser degree (odds ratio 1.4, 95% confidence interval 1.19 to 1.54). No evidence was found that incentives, re-ordering of questions or including an information brochure with the questionnaire confer any additional advantage. Conclusion Implementing repeat mailing strategies and/or telephone reminders may improve response to postal questionnaires in health care research. Making the questionnaire shorter may also improve response rates. There is a lack of evidence to suggest that incentives are useful. In the context of health care research all strategies to improve response to postal questionnaires require further evaluation

Identification of 4-amino-thieno[2,3-d]pyrimidines as QcrB inhibitors in Mycobacterium tuberculosis

Antibiotic resistance is a global crisis that threatens our ability to treat bacterial infections, such as tuberculosis, caused b