Accuracy of wearable physical activity trackers in people with Parkinson's disease

Introduction: The purpose of this study was to determine the accuracy of the Fitbit Charge HR (TM) and Garmin vivosmart (R) HR in measuring steps and reflecting intensity of activity in people with Parkinson's disease (PD).Methods: Thirty-three people with mild-moderate PD performed six, two-minute indoor walks at their self-selected walking pace, and at target cadences of 60, 80, 100, 120 and 140 beats/min. A 500 m outdoor walk with terrain challenges was also performed. Step count was recorded by the two wrist-worn activity trackers (Fitbit Charge HR (TM) and Garmin vivosmart (R) HR) and compared to an accelerometer (ActivPAL3 (TM)). Intensity was recorded by a portable breath-by-breath gas analyser (VO2), heart rate and Borg scale.Results: Both commercial activity trackers had low error ( 0.68; p = 80steps/min. The Fitbit had higher error was less consistent for all target cadences >= 80steps/min. Cadence measured by the Fitbit and Garmin weakly reflected increases in heart rate (ICCs 0.27-0.28; p 0.05).Conclusion: The Garmin device was more accurate at reflecting step count across a broader range of walking cadences than the Fitbit, but neither strongly reflected intensity of activity. While not intended to replace research grade devices, these wrist-worn devices may be a clinically useful adjunct to exercise therapy to increase physical activity in people with PD

Digging the New York City Skyline: Soil Fungal Communities in Green Roofs and City Parks

In urban environments, green roofs provide a number of benefits, including decreased urban heat island effects and reduced energy costs for buildings. However, little research has been done on the non-plant biota associated with green roofs, which likely affect their functionality. For the current study, we evaluated whether or not green roofs planted with two native plant communities in New York City functioned as habitats for soil fungal communities, and compared fungal communities in green roof growing media to soil microbial composition in five city parks, including Central Park and the High Line. Ten replicate roofs were sampled one year after planting; three of these roofs were more intensively sampled and compared to nearby city parks. Using Illumina sequencing of the fungal ITS region we found that green roofs supported a diverse fungal community, with numerous taxa belonging to fungal groups capable of surviving in disturbed and polluted habitats. Across roofs, there was significant biogeographical clustering of fungal communities, indicating that community assembly of roof microbes across the greater New York City area is locally variable. Green roof fungal communities were compositionally distinct from city parks and only 54% of the green roof taxa were also found in the park soils. Phospholipid fatty acid analysis revealed that park soils had greater microbial biomass and higher bacterial to fungal ratios than green roof substrates. City park soils were also more enriched with heavy metals, had lower pH, and lower quantities of total bases (Ca, K, and Mg) compared to green roof substrates. While fungal communities were compositionally distinct across green roofs, they did not differentiate by plant community. Together, these results suggest that fungi living in the growing medium of green roofs may be an underestimated component of these biotic systems functioning to support some of the valued ecological services of green roofs

Non-metric multidimensional scaling plots of fungal communities for the three green roofs that were more intensively sampled.

<p>Fungal communities were significantly clustered by roof (a), but not by plant community (b).</p

Plant species from the two native plant communities used in the experimental green roofs for this study.

<p>Plant species from the two native plant communities used in the experimental green roofs for this study.</p

Locations of the ten green roofs sampled in this study, which were distributed across all five boroughs of New York City.

<p>The map was created by Jeremy Law at Columbia University.</p

Sampling scheme for the general (a) and fine-scale (b) sampling with an image of a representative green roof.

<p>The general sampling scheme was used for all ten green roofs and the six cores were composited for three planting boxes on each roof. For the fine-scale sampling on the three target roofs, each core was treated as a separate sample.</p

The relative abundance of fungal phyla detected from green roof substrates and city park soils.

<p>Asterisks denote significant differences at p<0.05. Numerical values for the proportional abundances of each fungal phylum in the parks compared to the green roofs are displayed below each bar.</p

Concentrations (in ppm) of heavy metals from green roof substrates and park soils. Asterisks above the bars denote significant differences at p<0.05.

<p>Concentrations (in ppm) of heavy metals from green roof substrates and park soils. Asterisks above the bars denote significant differences at p<0.05.</p

Relative abundance of green roof OTUs aligning to fungal genera in the Glomeromycota (arbuscular mycorrhizal fungi).

<p>Relative abundance of green roof OTUs aligning to fungal genera in the Glomeromycota (arbuscular mycorrhizal fungi).</p

The most abundant fungal OTUs from the Central Park samples.

<p>Taxonomy is provided for the best match in Genbank. Only OTUs with sequences greater than 500 are reported.</p