Abstract Hodics TM, Nakatsuka K, Upreti B, Alex A, Smith PS, Pezzullo JC. Wolf Motor Function Test for characterizing moderate to severe hemiparesis in stroke patients. Objective To extend the ...applicability of the Wolf Motor Function Test (WMFT) to describe the residual functional abilities of moderate to severely affected stroke patients. Design Data were collected as part of 2 double-blind, sham-controlled, randomized interventional studies: the Transcranial Direct Current Stimulation (tDCS) in Chronic Stroke Recovery and the tDCS Enhanced Stroke Recovery and Cortical Reorganization. Stroke patients were evaluated with the upper extremity Fugl-Meyer (UFM) and the WMFT in the same setting before treatment. Setting University inpatient rehabilitation and outpatient clinic. Participants Stroke patients (N=32) with moderate to severe hemiparesis enrolled in the tDCS in Chronic Stroke Recovery and the tDCS Enhanced Stroke Recovery and Cortical Reorganization studies. Interventions Not applicable. Main Outcome Measures WMFT scores were calculated using (1) median performance times and (2) a new calculation using the mean rate of performance. We compared the distribution of values from the 2 methods and examined the WMFT-UFM correlation for the traditional and the new calculation. Results WMFT rate values were more evenly distributed across their range than median WMFT time scores. The association between the WMFT rate and UFM was as good as the association between the median WMFT time scores and UFM (Spearman ρ, .84 vs −.79). Conclusions The new WMFT mean rate of performance is valid and a more sensitive measure in describing the functional activities of the moderate to severely affected upper extremity of stroke subjects and avoids the pitfalls of the median WMFT time calculations.
Mitochondrial dysfunction often leads to neurodegeneration and is considered one of the main causes of neurological disorders, such as Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) ...and other age-related diseases. Mitochondrial dysfunction is tightly linked to oxidative stress and accumulating evidence suggests the association between oxidative stress and neurological disorders. However, there is insufficient knowledge about the role of pro-oxidative shift in cellular redox and impairment of redox-sensitive signaling in the development of neurodegenerative pathological conditions. To gain a more complete understanding of the relationship between mitochondria, redox status, and neurodegenerative disorders, we investigated the effect of mitochondrial thiol-dependent peroxidases, peroxiredoxins (Prxs), on the physiological characteristics of flies, which change with pathologies such as PD, ALS and during aging. We previously found that through their ability to sense changes in redox and regulate redox-sensitive signaling, Prxs play a critical role in maintaining global thiol homeostasis, preventing age-related apoptosis and chronic activation of the immune response. We also found that the phenotype of flies under-expressing Prxs in mitochondria shares many characteristics with the phenotype of
models of neurological disorders such as ALS, including impaired locomotor activity and compromised redox balance. Here, we expanded the study and found that under-expression of mitochondrial Prxs leads to behavioral changes associated with neural function, including locomotor ability, sleep-wake behavior, and temperature-sensitive paralysis. We also found that under-expression of mitochondrial Prxs with a motor-neuron-specific driver, D42-GAL4, was a determining factor in the development of the phenotype of shortened lifespan and impaired motor activity in flies. The results of the study suggest a causal link between mitochondrial Prx activity and the development of neurological disorders and pre-mature aging.
Previously, we have shown that flies under-expressing the two mitochondrial peroxiredoxins (Prxs), dPrx3 and dPrx5, display increases in tissue-specific apoptosis and dramatically shortened life ...span, associated with a redox crisis, manifested as changes in GSH:GSSG and accumulation of protein mixed disulfides. To identify specific pathways responsible for the observed biological effects, we performed a transcriptome analysis. Functional clustering revealed a prominent group enriched for immunity-related genes, including a considerable number of NF-kB-dependent antimicrobial peptides (AMP) that are up-regulated in the Prx double mutant. Using qRT-PCR analysis we determined that the age-dependent changes in AMP levels in mutant flies were similar to those observed in controls when scaled to percentage of life span. To further clarify the role of Prx-dependent mitochondrial signaling, we expressed different forms of dPrx5, which unlike the uniquely mitochondrial dPrx3 is found in multiple subcellular compartments, including mitochondrion, nucleus and cytosol. Ectopic expression of dPrx5 in mitochondria but not nucleus or cytosol partially extended longevity under normal or oxidative stress conditions while complete restoration of life span occurred when all three forms of dPrx5 were expressed from the wild type dPrx5 transgene. When dPrx5 was expressed in mitochondria or in all three compartments, it substantially delayed the development of hyperactive immunity while expression of cytosolic or nuclear forms had no effect on the immune phenotype. The data suggest a critical role of mitochondria in development of chronic activation of the immune response triggered by impaired redox control.
•Underexpression of mitochondrial peroxiredoxins induces the immune response.•Mitochondrial peroxiredoxin 5 delays the onset of hyperactive immunity.•Mitochondrial peroxiredoxin 5 partially protects from oxidative stress.•Shortened longevity of the double dprx3&5 mutant is rescued by mitochondrial dPrx5.
Tidal wetlands play an important role in global carbon cycling by storing carbon in sediment at millennial time scales, transporting dissolved carbon into coastal waters, and contributing ...significantly to global CH4 budgets. However, these ecosystems' greenhouse gas monitoring and predictions are challenging due to spatial heterogeneity and tidal flooding. We utilized eddy covariance and chamber measurements to quantify fluxes of CO2 and CH4 at a restored tidal saltmarsh across spatial and temporal scales. Eddy covariance data revealed that the site was a strong net sink for CO2 (−387 g C‐CO2 m−2 yr−1, SD = 46) and a small net source of CH4 (0.7 g C‐CH4 m−2 yr−1, SD = 0.4). After partitioning net ecosystem exchange of CO2 into gross primary production and ecosystem respiration, we found that high net uptake of CO2 was due to low respiration emissions rather than high photosynthetic rates. We also found that respiration rates varied between land covers with increased respiration in mudflats compared to vegetated areas. Daytime soil chamber measurements revealed that the greatest CO2 emission was from higher elevation mudflat soils (0.5 μmol m−2s−1, SE = 1.3) and CH4 emission was greatest from lower elevation Spartina foliosa soils (1.6 nmol m−2s−1, SD = 8.2). Overall, these results highlight the importance of the relationships between wetland plant community and elevation, and inundation for CO2 and CH4 fluxes. Future research should include the use of high‐resolution imagery, automated chambers, and a focus on quantifying carbon exported in tidal waters.
Plain Language Summary
At the ecosystem level, a restored tidal salt marsh in the South San Francisco Bay California took in more carbon dioxide (CO2) from the atmosphere through photosynthetic activity than it emitted through respiration, and it emitted very small amounts of methane (CH4). This site appears to be a stronger sink for CO2 compared to other tidal marsh sites due to the very low rate of CO2 being lost through respiration to the atmosphere, rather than strong photosynthetic rates. We also found that ecosystem level CO2 emissions and the responses to temperature and light varied based on land cover type. By measuring soil surface emissions from each of the main land cover types of pickleweed, cordgrass, and mudflats we found that on average soils with lower elevation where cordgrass grows were stronger sources of CH4 while mudflat soils with greater elevation were stronger sources of CO2.
Key Points
Soil chamber measurements were able to detect significant differences in CO2 and CH4 fluxes between land cover types
Vegetation and microtopography are drivers of the spatially heterogeneous CO2 and CH4 emissions within the wetland
At the ecosystem level, high net uptake of CO2 was the result of low respiration emissions, suggesting lateral transport of dissolved CO2
Abstract
Tidal wetlands play an important role in global carbon cycling by storing carbon in sediment at millennial time scales, transporting dissolved carbon into coastal waters, and contributing ...significantly to global CH
4
budgets. However, these ecosystems' greenhouse gas monitoring and predictions are challenging due to spatial heterogeneity and tidal flooding. We utilized eddy covariance and chamber measurements to quantify fluxes of CO
2
and CH
4
at a restored tidal saltmarsh across spatial and temporal scales. Eddy covariance data revealed that the site was a strong net sink for CO
2
(−387 g C‐CO
2
m
−2
yr
−1
, SD = 46) and a small net source of CH
4
(0.7 g C‐CH
4
m
−2
yr
−1
, SD = 0.4). After partitioning net ecosystem exchange of CO
2
into gross primary production and ecosystem respiration, we found that high net uptake of CO
2
was due to low respiration emissions rather than high photosynthetic rates. We also found that respiration rates varied between land covers with increased respiration in mudflats compared to vegetated areas. Daytime soil chamber measurements revealed that the greatest CO
2
emission was from higher elevation mudflat soils (0.5 μmol m
−2
s
−1
, SE = 1.3) and CH
4
emission was greatest from lower elevation
Spartina foliosa
soils (1.6 nmol m
−2
s
−1
, SD = 8.2). Overall, these results highlight the importance of the relationships between wetland plant community and elevation, and inundation for CO
2
and CH
4
fluxes. Future research should include the use of high‐resolution imagery, automated chambers, and a focus on quantifying carbon exported in tidal waters.
Plain Language Summary
At the ecosystem level, a restored tidal salt marsh in the South San Francisco Bay California took in more carbon dioxide (CO
2
) from the atmosphere through photosynthetic activity than it emitted through respiration, and it emitted very small amounts of methane (CH
4
). This site appears to be a stronger sink for CO
2
compared to other tidal marsh sites due to the very low rate of CO
2
being lost through respiration to the atmosphere, rather than strong photosynthetic rates. We also found that ecosystem level CO
2
emissions and the responses to temperature and light varied based on land cover type. By measuring soil surface emissions from each of the main land cover types of pickleweed, cordgrass, and mudflats we found that on average soils with lower elevation where cordgrass grows were stronger sources of CH
4
while mudflat soils with greater elevation were stronger sources of CO
2
.
Key Points
Soil chamber measurements were able to detect significant differences in CO
2
and CH
4
fluxes between land cover types
Vegetation and microtopography are drivers of the spatially heterogeneous CO
2
and CH
4
emissions within the wetland
At the ecosystem level, high net uptake of CO
2
was the result of low respiration emissions, suggesting lateral transport of dissolved CO
2
PDF
