Evidence that process simulations reduce anxiety in patients receiving dental treatment: randomized exploratory trial

Process simulations – mental simulations that ask people to imagine the process of completing a task – have been shown to decrease anxiety in students facing hypothetical or psychological threats in the short term. The aim of the present study was to see whether process simulations could reduce anxiety in a sample of the general population attending a dental practice, and whether these effects could be sustained throughout treatment. Participants (N = 75) were randomized to an experimental condition where they were asked to simulate mentally the process of seeing the dentist, or to a control condition where they were asked to simulate mentally the outcome of seeing the dentist. Findings showed that participants in the experimental condition were significantly less anxious both before and after their consultations. Self-efficacy and self-esteem remained unchanged. This study suggests that process simulation is one active ingredient in anxiety treatment programs and further research is required to enhance its effects

The relationship between brain structure, motor performance, and early musical training

The current dissertation investigated the relationship between brain structure, motor performance, and musical training. Two structural magnetic resonance imaging (MRI) techniques were used: voxel-based morphometry (VBM) and diffusion tensor imaging (DTI). The first study examined the structural correlates of visuomotor synchronisation performance in normal adults. DTI analyses showed that individual differences in synchronisation performance were negatively correlated with white-matter integrity in a region underlying bilateral sensorimotor cortex. Performance was also positively correlated with radial diffusivity in this region, suggesting the influence of a crossing fibre tract. Fibre tractography identified two fibre populations in this region: the corticospinal tract and superior longitudinal fasciculus (SLF). The SLF links parietal and auditory cortical regions previously shown to be engaged during performance of this task in a functional MRI study with the same sample. VBM analyses showed that grey-matter volume in cerebellar regions important for learning was related to the rate of improvement in synchronisation during learning of the task. The second study explored how musical training during early childhood may have long-lasting effects on brain structure and sensorimotor synchronisation performance. DTI was used to compare white-matter structure in three groups: (1) early-trained musicians (ET; before age seven), (2) late-trained musicians (LT; after age seven), and (3) nonmusicians. Groups were also tested on a visuomotor synchronisation task. ET and LT were matched for years of musical training and experience to isolate the possible effect of age of onset of musical training. Behaviourally, ET outperformed LT and nonmusicians on the synchronisation task. DTI results showed that ET had greater white-matter integrity than LT in the posterior midbody of the corpus callosum, a region connecting bilateral sensorimotor cortices. Measures of white-matter integrity extracted from this region correlated with both synchronisation performance and age of onset of musical training. These findings provide evidence that musical training during a potential sensitive period in development can differentially influence white-matter structure and behavioural performance. Our results are consistent with literature supporting the links between individual differences in brain structure and performance, and training and structural plasticity. They suggest that brain structure is the result of interactions between pre-existing factors, developmental factors, and training and experience

Efforts to Reduce International Space Station Crew Maintenance for the Management of the Extravehicular Mobility Unit Transport Loop Water Quality

The EMU (Extravehicular Mobility Unit) contains a semi-closed-loop re-circulating water circuit (Transport Loop) to absorb heat into a LCVG (Liquid Coolant and Ventilation Garment) worn by the astronaut. A second, single-pass water circuit (Feed-water Loop) provides water to a cooling device (Sublimator) containing porous plates, and that water sublimates through the porous plates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. The quality of the EMU Transport Loop water is maintained through the use of a water processing kit (ALCLR Airlock Cooling Loop Remediation) that is used to periodically clean and disinfect the water circuit. Opportunities to reduce crew time associated with on-orbit ALCLR operations include a detailed review of the historical water quality data for evidence to support an extension to the implementation cycle. Furthermore, an EMU returned after 2-years of use on the ISS (International Space Station) is being used as a test bed to evaluate the results of extended and repeated ALCLR implementation cycles. Finally, design, use and on-orbit location enhancements to the ALCLR kit components are being considered to allow the implementation cycle to occur in parallel with other EMU maintenance and check-out activities, and to extend the life of the ALCLR kit components. These efforts are undertaken to reduce the crew-time and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a post-Shuttle 6-year service life

Introducing high-cost health care to patients: dentists' accounts of offering dental implant treatment

Objectives: The decision-making process within health care has been widely researched, with shared decision-making, where both patients and clinicians share technical and personal information, often being cited as the ideal model. To date, much of this research has focused on systems where patients receive their care and treatment free at the point of contact (either in government-funded schemes or in insurance-based schemes). Oral health care often involves patients making direct payments for their care and treatment, and less is known about how this payment affects the decision-making process. It is clear that patient characteristics influence decision-making, but previous evidence suggests that clinicians may assume characteristics rather than eliciting them directly. The aim was to explore the influences on how dentists' engaged in the decision-making process surrounding a high-cost item of health care, dental implant treatments (DITs). Methods: A qualitative study using semi-structured interviews was undertaken using a purposive sample of primary care dentists (n = 25). Thematic analysis was undertaken to reveal emerging key themes. Results: There were differences in how dentists discussed and offered implants. Dentists made decisions about whether to offer implants based on business factors, professional and legal obligations and whether they perceived the patient to be motivated to have treatment and their ability to pay. There was evidence that assessment of these characteristics was often based on assumptions derived from elements such as the appearance of the patient, the state of the patient's mouth and demographic details. The data suggest that there is a conflict between three elements of acting as a healthcare professional: minimizing provision of unneeded treatment, trying to fully involve patients in shared decisions and acting as a business person with the potential for financial gain. Conclusions: It might be expected that in the context of a high-cost healthcare intervention for which patients pay the bill themselves, that decision-making would be closer to an informed than a paternalistic model. Our research suggests that paternalistic decision-making is still practised and is influenced by assumptions about patient characteristics. Better tools and training may be required to support clinicians in this area of practice

Confirmation of mass-independent Ni isotopic variability in iron meteorites

Funding: NERC (NE/F007329/1), STFC (ST/F002734/1) and NHM.We report high-precision analyses of internally-normalised Ni isotope ratios in 12 bulk iron meteorites. Our measurements of 60Ni/61Ni, 62Ni/61Ni and 64Ni/61Ni normalised to 58Ni/61Ni and expressed in parts per ten thousand (‱) relative to NIST SRM 986 as ε60Ni586, ε62Ni5861 and ε64Ni5861 vary by 0.146, 0.228 and 0.687, respectively. The precision on a typical analysis is 0.03, 0.05nd 0.08‱ for ε60Ni5861,  ε62Ni5861 and ε64Ni5861, respectively, which is comparable to our sample reproducibility. We show that this ‘mass-independent’ Ni isotope variability cannot be ascribed to interferences, inaccurate correction of instrumental or natural mass-dependent fractionation, fractionation controlled by nuclear field shift effects, nor the influence of cosmic ray spallation. These results thus document the presence of mass-independent Ni isotopic heterogeneity in bulk meteoritic samples, as previously proposed by Regelous et al. (2008) (EPSL 272, 330–338), but our new analyses are more precise and include determination of 64Ni. Intriguingly, we find that terrestrial materials do not yield homogenous internally-normalised Ni isotope compositions, which, as pointed out by Young et al. (2002) (GCA 66, 1095–1104), may be the expected result of using the exponential (kinetic) law and atomic masses to normalise all fractionation processes. The certified Ni isotope reference material NIST SRM 986 defines zero in this study, while appropriate ratios for the bulk silicate Earth are given by the peridotites JP-1 and DTS-2 and, relative to NIST SRM 986, yield deviations in ε60Ni5861, ε62Ni5861 and ε64Ni5861 of −0.006, 0.036 and 0.119‱, respectively. There is a strong positive correlation between ε64Ni5861 and ε62Ni5861in iron meteorites analyses, with a slope of 3.03 ± 0.71. The variations of Ni isotope anomalies in iron meteorites are consistent with heterogeneous distribution of a nucleosynthetic component from a type Ia supernova into the proto-solar nebula.PostprintPeer reviewe

Asymptotics of Relativistic Spin Networks

The stationary phase technique is used to calculate asymptotic formulae for SO(4) Relativistic Spin Networks. For the tetrahedral spin network this gives the square of the Ponzano-Regge asymptotic formula for the SU(2) 6j symbol. For the 4-simplex (10j-symbol) the asymptotic formula is compared with numerical calculations of the Spin Network evaluation. Finally we discuss the asymptotics of the SO(3,1) 10j-symbol.Comment: 31 pages, latex. v3: minor clarification

Cosmic biology in perspective

Abstract: A series of astronomical observations obtained over the period 1986 to 2018 supports the idea that life is a cosmic rather than a purely terrestrial or planetary phenomenon. These include (1) the detection of biologically relevant molecules in interstellar clouds and in comets, (2) mid-infrared spectra of interstellar grains and the dust from comets, (3) a diverse set of data from comets including the Rosetta mission showing consistency with biology and (4) the frequency of Earth-like or habitable planets in the Galaxy. We argue that the conjunction of all the available data suggests the operation of cometary biology and interstellar panspermia rather than the much weaker hypothesis of comets being only the source of the chemical building blocks of life. We conclude with specific predictions on the properties expected of extra-terrestrial life if it is discovered on Enceladus, Europa or beyond. A radically different biochemistry elsewhere can be considered as a falsification of the theory of interstellar panspermia

A Sample of Very Young Field L Dwarfs and Implications for the Brown Dwarf "Lithium Test" at Early Ages

Using a large sample of optical spectra of late-type dwarfs, we identify a subset of late-M through L field dwarfs that, because of the presence of low-gravity features in their spectra, are believed to be unusually young. From a combined sample of 303 field L dwarfs, we find observationally that 7.6+/-1.6% are younger than 100 Myr. This percentage is in agreement with theoretical predictions once observing biases are taken into account. We find that these young L dwarfs tend to fall in the southern hemisphere (Dec < 0 deg) and may be previously unrecognized, low-mass members of nearby, young associations like Tucana-Horologium, TW Hydrae, beta Pictoris, and AB Doradus. We use a homogeneously observed sample of roughly one hundred and fifty 6300-10000 Angstrom spectra of L and T dwarfs taken with the Low-Resolution Imaging Spectrometer at the W. M. Keck Observatory to examine the strength of the 6708-A Li I line as a function of spectral type and further corroborate the trends noted by Kirkpatrick et al. (2000). We use our low-gravity spectra to investigate the strength of the Li I line as a function of age. The data weakly suggest that for early- to mid-L dwarfs the line strength reaches a maximum for a few 100 Myr, whereas for much older (few Gyr) and much younger (<100 Myr) L dwarfs the line is weaker or undetectable. We show that a weakening of lithium at lower gravities is predicted by model atmosphere calculations, an effect partially corroborated by existing observational data. Larger samples containing L dwarfs of well determined ages are needed to further test this empirically. If verified, this result would reinforce the caveat first cited in Kirkpatrick et al. (2006) that the lithium test should be used with caution when attempting to confirm the substellar nature of the youngest brown dwarfs.Comment: 73 pages with 22 figures; to appear in ApJ (Dec 20, 2008, v689n2 issue

`imaka - a ground-layer adaptive optics system on Maunakea

We present the integration status for `imaka, the ground-layer adaptive optics (GLAO) system on the University of Hawaii 2.2-meter telescope on Maunakea, Hawaii. This wide-field GLAO pathfinder system exploits Maunakea's highly confined ground layer and weak free-atmosphere to push the corrected field of view to ~1/3 of a degree, an areal field approaching an order of magnitude larger than any existing or planned GLAO system, with a FWHM ~ 0.33 arcseconds in the visible and near infrared. We discuss the unique design aspects of the instrument, the driving science cases and how they impact the system, and how we will demonstrate these cases on the sky.Comment: 9 pages, 5 figure