Physical activity self-management and coaching compared to social interaction in huntington disease: results from the ENGAGE-HD randomized, controlled, pilot feasibility trial.

Abstract Background: Self-management and self-efficacy for physical activity is not routinely considered in neurologic rehabilitation. Objective: We assessed feasibility and outcomes of a 14 week physical activity self-management and coaching intervention compared with social contact in Huntington's disease (HD) to inform the design of a future full-scale trial. Design: Assessor blind, multi-site, randomized pilot feasibility trial. Setting: Participants were recruited and assessed at baseline, 16 weeks following randomisation, and then again at 26 weeks in HD specialist clinics with intervention delivery by trained coaches in the participants’ homes. Patients and Intervention: People with HD were allocated to the ENGAGE-HD physical activity coaching intervention or a social interaction intervention. Measurements: Eligibility, recruitment, retention and intervention adherence were determined at 16 weeks. Other outcomes of interest included measures of functional, home and community mobility, self-efficacy, physical activity and disease-specific measures of motor and cognition. Fidelity and costs for both the physical activity and social comparator interventions were established. Results: Forty % (n=46) of eligible patients were enrolled and 22 randomised to the physical intervention and 24 to social intervention. Retention rates in the physical intervention and social intervention were 77% and 92% respectively. Minimum adherence criteria were achieved by 82% of participants in the physical intervention and 100% in the social intervention. There was no indication of between group treatment effects on function, however increases in self-efficacy for exercise and self-reported levels of physical activity in the physical intervention lends support to our pre-defined intervention logic model. Limitations: The use of self-report measures may have introduced bias. Conclusions: An HD physical activity self-management and coaching intervention is feasible and worthy of further investigation.Health and Care Research Wale

Development and Delivery of a Physical Activity Intervention for People With Huntington Disease:Facilitating Translation to Clinical Practice

Background and Purpose: We studied the development and delivery of a 14-week complex physical activity intervention for people with Huntington disease, where detailed information about the intervention was fully embedded in the trial design process. Methods: Intervention Development: The intervention was developed through a series of focus groups. The findings from the focus groups informed the development of a logic model for the physical activity intervention that was broadly consistent with the framework of self-determination theory. Intervention Delivery: Key components underpinning the delivery of the intervention were implemented including a defined coach training program and intervention fidelity assessment methods. Training of coaches (physical therapists, occupational therapists, research nurses, and exercise trainers) was delivered via group and 1:1 training sessions using a detailed coach's manual, and with ongoing support via video calls, and e-mail communication as needed. Detailed documentation was provided to determine costs of intervention development and coach training. Results: Intervention delivery coaches at 8 sites across the United Kingdom participated in the face-to-face training. Self-report checklists completed by each of the coaches indicated that all components of the intervention were delivered in accordance with the protocol. Mean (standard deviation) intervention fidelity scores (n = 15), as measured using a purpose-developed rating scale, was 11 (2.4) (out of 16 possible points). Coaches' perceptions of intervention fidelity were similarly high. The total cost of developing the intervention and providing training was [pounds]30,773 ($47,042 USD). Discussion and Conclusions: An important consideration in promoting translation of clinical research into practice is the ability to convey the detailed components of how the intervention was delivered to facilitate replication if the results are favorable. This report presents an illustrative example of a physical activity intervention, including the development and the training required to deliver it. This approach has the potential to facilitate reproducibility, evidence synthesis, and implementation in clinical practice

The Stellar Halos of Massive Elliptical Galaxies

We use the Mitchell Spectrograph (formerly VIRUS-P) on the McDonald Observatory 2.7m Harlan J. Smith Telescope to search for the chemical signatures of massive elliptical galaxy assembly. The Mitchell Spectrograph is an integral-field spectrograph with a uniquely wide field of view (107x107 sq arcsec), allowing us to achieve remarkably high signal-to-noise ratios of ~20-70 per pixel in radial bins of 2-2.5 times the effective radii of the eight galaxies in our sample. Focusing on a sample of massive elliptical galaxies with stellar velocity dispersions sigma* > 150 km/s, we study the radial dependence in the equivalent widths (EWs) of key metal absorption lines. By twice the effective radius, the Mgb EWs have dropped by ~50%, and only a weak correlation between sigma* and Mgb EW remains. The Mgb EWs at large radii are comparable to those seen in the centers of elliptical galaxies that are approximately an order of magnitude less massive. We find that the well-known metallicity gradients often observed within an effective radius continue smoothly to 2.5R_e, while the abundance ratio gradients remain flat. Much like the halo of the Milky Way, the stellar halos of our galaxies have low metallicities and high alpha-abundance ratios, as expected for very old stars formed in small stellar systems. Our observations support a picture in which the outer parts of massive elliptical galaxies are built by the accretion of much smaller systems whose star formation history was truncated at early times.Comment: To appear in ApJ, 15 pages, 9 figure

Causal and associational language in observational health research: a systematic evaluation

We estimated the degree to which language used in the high profile medical/public health/epidemiology literature implied causality using language linking exposures to outcomes and action recommendations; examined disconnects between language and recommendations; identified the most common linking phrases; and estimated how strongly linking phrases imply causality. We searched and screened for 1,170 articles from 18 high-profile journals (65 per journal) published from 2010-2019. Based on written framing and systematic guidance, three reviewers rated the degree of causality implied in abstracts and full text for exposure/outcome linking language and action recommendations. Reviewers rated the causal implication of exposure/outcome linking language as None (no causal implication) in 13.8%, Weak 34.2%, Moderate 33.2%, and Strong 18.7% of abstracts. The implied causality of action recommendations was higher than the implied causality of linking sentences for 44.5% or commensurate for 40.3% of articles. The most common linking word in abstracts was “associate” (45.7%). Reviewer’s ratings of linking word roots were highly heterogeneous; over half of reviewers rated “association” as having at least some causal implication. This research undercuts the assumption that avoiding “causal” words leads to clarity of interpretation in medical research

Terrestrial Paleoclimate of the Cenozoic: Insights from and Developments of the Soil Carbonate Clumped Isotope Thermometer

Thesis (Ph.D.)--University of Washington, 2019Land temperature at the surface of the Earth is a first-order parameter used to describe climate, but reliable and widespread measurements of this basic parameter through geologic time has eluded geochemists and geologists for decades. The carbonate clumped isotope geothermometer, which uses the bond-ordering of the carbon and oxygen isotopes in a carbonate mineral, is a relatively new tool that can be used to measure surface temperature on geologic timescales. Chapter 1 introduces carbonate clumped isotope geochemistry. In the subsequent four research chapters, this thesis first refines fundamental methodologies, then improves our understanding of the proxy-system by examining modern soil carbonates, and finally applies the thermometer to reconstruct terrestrial paleoclimate in the early Paleogene. In Chapter 2, I empirically create a clumped isotope-temperature relationship that can be used to estimate the growth temperature of natural carbonates. I rule out the two primary hypotheses that were proposed to explain discrepancies between existing ∆47 -temperature calibrations: 1) synthesis methods caused kinetic isotope effects in calibration samples, and/or 2) the temperature of the acid which was used to digest the calcite for analysis created an analytical artifact. I precipitated >56 synthetic calcite samples at known temperatures, replicating the methodologies used by previously published discrepant calibrations. I analyzed the samples by digesting the calcite at both 90 °C and 25 °C. My results showed that the temperature-∆47 relationship does not vary with precipitation method or acid digestion temperature. Instead, I suggest that the previously observed variations in empirical calibrations were largely due to poor sample replication and small number statistics. I also show the importance of using appropriate constants in the calculation of ∆47 to correct for the¬ mass interference between 13C and 17O during mass spectrometry (as described in companion paper, Schauer, Kelson et al., 2016). Through this research, I produced a new and robust empirical calibration that can be used to calculate growth temperatures from natural calcite materials. Chapter 3 investigates the seasonal bias in soil carbonates by re-examining in aggregate the published ∆47 -temperature data from >200 Holocene soil carbonate samples. In this synthesis, I re-calculate and update ∆47¬ values to reflect modern standards in methodology. The updated data confirm the general assumption that most soil carbonates have a ∆47 temperature that is warm-season biased. However, importantly, I show that modern soil carbonates have ∆47-temperatures that differ from mean annual air temperatures by -5 to 24 °C. The variation in the magnitude of seasonal bias can be partially explained by differences in the annual timing of rain/snow, the texture of the host soil matrix, and vegetative cover. This variation in seasonal bias has profound implications for using soil carbonate ∆47 in paleoclimate applications and underscores the need for a process-based understanding of soil carbonate formation. Chapter 4 builds an understanding of soil carbonate formation that is based in soil physics and chemistry by numerically predicting the timing of calcite growth in a 1D soil profile. Using a software package called HYDRUS-1D (Šimůnek et al., 2009), I calculate soil water content, soil temperatures, soil CO2 productions and concentrations, and carbonate chemistry. I show that the timing of large rain events controls the timing of carbonate accumulation in a soil profile. During storms, soil respiration increases, which increases soil CO2 and dissolves soil carbonate. The subsequent re-precipitation of soil carbonate as soil CO2 decreases post-storm makes up the majority of the total preserved soil carbonate. This result undermines the existing assumption that soil carbonates form slowly during evaporation during dry periods. I show that soil texture and the timing and character of rainfall will control the seasonal bias recorded by soil carbonates. This process-based understanding of soil carbonate formation will enable more nuanced and accurate interpretations of paleo-temperatures and meteoric waters. Chapter 5 uses the clumped isotope composition of fossilized soil carbonates collected in the Tornillo Basin of Big Bend National Park, Texas (30°N) to investigate the greenhouse climate of the Paleocene and early Eocene. I first use a combination of textural evidence and thermal modeling to identify that the isotopic signatures of the soil carbonates collected reflect primary environmental signals. The clumped isotope temperature record derived from these carbonates show an increase from 25 ± 4 to 32 ± 2 °C from the Paleocene to the Eocene, respectively, and a corresponding increase in calculated 18O of soil waters. These temperatures are lower than the temperatures predicted by global circulation models given the high pCO2 conditions and the subtropical location; they are also similar to modern summer temperatures. These results may suggest habitable, near-coast environments persisted even during the peak-CO2 conditions of the early Cenozoic. In conclusion, this thesis expands the ability to reconstruct terrestrial paleoclimates with carbonate clumped isotope thermometry and highlights future challenges. Applications of clumped isotope thermometry are no longer limited by analytical precision in most settings. Instead, robust paleoclimate reconstructions hinge upon accurate characterizations of the seasonal bias of the proxy and diagenetic alteration. A more complete understanding of the evolution of Cenozoic climate on land awaits further analyses from stratigraphic sections that are spatially diverse and temporally overlapping

Clumped Isotopes Record a Glacial‐Interglacial Shift in Seasonality of Soil Carbonate Accumulation in the San Luis Valley, Southern Rocky Mountains, USA

Abstract Clumped isotope paleothermometry using pedogenic carbonates is a powerful tool for investigating past climate changes. However, location‐specific seasonal patterns of precipitation and soil moisture cause systematic biases in the temperatures they record, hampering comparison of data across large areas or differing climate states. To account for biases, more systematic studies of carbonate forming processes are needed. We measured modern soil temperatures within the San Luis Valley of the Rocky Mountains and compared them to paleotemperatures determined using clumped isotopes. For Holocene‐age samples, clumped isotope results indicate carbonate accumulated at a range of temperatures with site averages similar to the annual mean. Paleotemperatures for late Pleistocene‐age samples (ranging 19–72 ka in age) yielded site averages only 2°C lower, despite evidence that annual temperatures during glacial periods were 5–9°C colder than modern. We use a 1D numerical model of soil physics to support the idea that differences in hydrologic conditions in interglacial versus glacial periods promote differences in the seasonal distribution of soil carbonate accumulation. Model simulations of modern (Holocene) conditions suggest that soil drying under low soil pCO2 favors year‐round carbonate accumulation in this region but peaking during post‐monsoon soil drying. During a “glacial” simulation with lowered temperatures and added snowpack, more carbonate accumulation shifted to the summer season. These experiments show that changing hydrologic regimes could change the seasonality of carbonate accumulation, which in this study blunts the use of clumped isotopes to quantify glacial‐interglacial temperature changes. This highlights the importance of understanding seasonal biases of climate proxies for accurate paleoenvironmental reconstruction

Reanalyzing carbonate clumped isotope calibration materials using robust carbonate standardization

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