Contribution of primary motor cortex to compensatory balance reactions

<p>Abstract</p> <p>Background</p> <p>Rapid compensatory arm reactions represent important response strategies following an unexpected loss of balance. While it has been assumed that early corrective actions arise largely from sub-cortical networks, recent findings have prompted speculation about the potential role of cortical involvement. To test the idea that cortical motor regions are involved in early compensatory arm reactions, we used continuous theta burst stimulation (cTBS) to temporarily suppress the hand area of primary motor cortex (M1) in participants prior to evoking upper limb balance reactions in response to whole body perturbation. We hypothesized that following cTBS to the M1 hand area evoked EMG responses in the stimulated hand would be diminished. To isolate balance reactions to the upper limb participants were seated in an elevated tilt-chair while holding a stable handle with both hands. The chair was held vertical by a magnet and was triggered to fall backward unpredictably. To regain balance, participants used the handle to restore upright stability as quickly as possible with both hands. Muscle activity was recorded from proximal and distal muscles of both upper limbs.</p> <p>Results</p> <p>Our results revealed an impact of cTBS on the amplitude of the EMG responses in the stimulated hand muscles often manifest as inhibition in the stimulated hand. The change in EMG amplitude was specific to the target hand muscles and occasionally their homologous pairs on the non-stimulated hand with no consistent effects on the remaining more proximal arm muscles.</p> <p>Conclusions</p> <p>Present findings offer support for cortical contributions to the control of early compensatory arm reactions following whole-body perturbation.</p

Carbon-sensitive pedotransfer functions for plant available water

Currently accepted pedotransfer functions show negligible effect of management-induced changes to soil organic carbon (SOC) on plant available water holding capacity (θAWHC), while some studies show the ability to substantially increase θAWHC through management. The Soil Health Institute\u27s North America Project to Evaluate Soil Health Measurements measured water content at field capacity using intact soil cores across 124 long-term research sites that contained increases in SOC as a result of management treatments such as reduced tillage and cover cropping. Pedotransfer functions were created for volumetric water content at field capacity (θFC) and permanent wilting point (θPWP). New pedotransfer functions had predictions of θAWHC that were similarly accurate compared with Saxton and Rawls when tested on samples from the National Soil Characterization database. Further, the new pedotransfer functions showed substantial effects of soil calcareousness and SOC on θAWHC. For an increase in SOC of 10 g kg–1 (1%) in noncalcareous soils, an average increase in θAWHC of 3.0 mm 100 mm–1 soil (0.03 m3 m–3) on average across all soil texture classes was found. This SOC related increase in θAWHC is about double previous estimates. Calcareous soils had an increase in θAWHC of 1.2 mm 100 mm–1 soil associated with a 10 g kg–1 increase in SOC, across all soil texture classes. New equations can aid in quantifying benefits of soil management practices that increase SOC and can be used to model the effect of changes in management on drought resilience

Linking soil microbial community structure to potential carbon mineralization: A continental scale assessment of reduced tillage

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical disturbance, and soil pH influenced microbial sensitivity to physical disturbance. Furthermore, 28% of amplicon sequence variants (ASVs), which were important in modeling Cmin, were enriched under soils managed with minimal physical disturbance. Sequences identified as enriched under minimal disturbance and important for modeling Cmin, were linked to organisms which could produce extracellular polymeric substances and contained metabolic strategies suited for tolerating environmental stressors. Understanding how physical disturbance shapes microbial communities across climates and inherent soil properties and drives changes in Cmin provides the context necessary to evaluate management impacts on standardized measures of soil microbial activity

Robust and persistent reactivation of SIV and HIV by N-803 and depletion of CD8+ cells

Human immunodeficiency virus (HIV) persists indefinitely in individuals with HIV who receive antiretroviral therapy (ART) owing to a reservoir of latently infected cells that contain replication-competent virus1–4. Here, to better understand the mechanisms responsible for latency persistence and reversal, we used the interleukin-15 superagonist N-803 in conjunction with the depletion of CD8+ lymphocytes in ART-treated macaques infected with simian immunodeficiency virus (SIV). Although N-803 alone did not reactivate virus production, its administration after the depletion of CD8+ lymphocytes in conjunction with ART treatment induced robust and persistent reactivation of the virus in vivo. We found viraemia of more than 60 copies per ml in all macaques (n = 14; 100%) and in 41 out of a total of 56 samples (73.2%) that were collected each week after N-803 administration. Notably, concordant results were obtained in ART-treated HIV-infected humanized mice. In addition, we observed that co-culture with CD8+ T cells blocked the in vitro latency-reversing effect of N-803 on primary human CD4+ T cells that were latently infected with HIV. These results advance our understanding of the mechanisms responsible for latency reversal and lentivirus reactivation during ART-suppressed infection

Quality of Life Improves with Alemtuzumab Over 6 Years in Relapsing-Remitting Multiple Sclerosis Patients with or without Autoimmune Thyroid Adverse Events: Post Hoc Analysis of the CARE-MS Studies

Introduction In clinical trials of alemtuzumab, autoimmune thyroid adverse events (AEs) were frequent. Here, we assess the impact of thyroid AEs on health-related quality of life (HRQL) in alemtuzumab-treated patients with relapsing-remitting multiple sclerosis (RRMS). Methods In phase 3 CARE-MS I (NCT00530348) and II (NCT00548405) trials, patients with RRMS were administered alemtuzumab 12 mg/day on 5 consecutive days at baseline and on 3 consecutive days 12 months later. Patients could participate in an extension study (NCT00930553) through year 6. HRQL was assessed at baseline and annually using the Functional Assessment of Multiple Sclerosis (FAMS), EuroQoL-5 Dimension Visual Analog Scale (EQ-5D VAS), and 36-Item Short-Form Survey (SF-36) questionnaires. Outcomes were analyzed in patients with or without thyroid AEs (nonserious or serious). A subset of patients with thyroid AEs was analyzed to assess HRQL before and during the onset of thyroid AEs. Results A total of 811 CARE-MS patients were treated with alemtuzumab. Of these, 342 (42%) patients experienced thyroid AEs over 6 years; serious thyroid AEs occurred in 44 (5%) patients. At year 6, HRQL outcomes generally remained slightly improved or similar to core study baseline in alemtuzumab-treated patients with or without thyroid AEs: FAMS (least-squares mean change from baseline without thyroid AEs, 0.7; with nonserious thyroid AEs, 5.1; with serious thyroid AEs, − 5.3), EQ-5D VAS (2.0; 3.0; − 6.8), SF-36 mental component summary (MCS [0.6; 1.6; − 2.8]), SF-36 physical component summary (PCS [0.8; 1.0; 1.1]). Over 6 years, 63–82% of patients in each group had improved/stable SF-36 MCS and PCS scores. Among patients with thyroid AE onset in year 3 (peak incidence), there were minimal differences between HRQL outcomes before onset (year 2) and after onset (year 3). Conclusion Autoimmune thyroid AEs (serious and nonserious) had minimal impact on HRQL in alemtuzumab-treated patients. These data may aid therapeutic decisions in patients with relapsing MS