Effect of tsDCS applied with different electrode configurations on the lumbar spinal circuits

Spinal Cord Injury (SCI) is a severe injury to the central nervous system (CNS) which, despite a heavy post injury rehabilitation regime, often leaves patients bound to a wheelchair or with other impairments diminishing their quality of life. Trans-spinal direct current stimulation (tsDCS) is a promising new technique for the treatment of SCI. During tsDCS a small direct current is applied to the spinal cord via two or more stimulation electrodes, placed over the backbone of a subject. The technique aims to alter the response of the neural pathways in the spinal cord, which is hypothesized to have a positive effect on the recovery of the damaged spinal cord neuronal networks. The objective of this study, is to assess how tsDCS modulates the excitability of the spinal cord and whether this modulation is dependent on the electrode placement configurations. The primary goal is to compare a new electrode placement configuration with one that is commonly used in previous tsDCS studies. This is assessed using the H- Reflex, whereby the novel configuration is hypothesized to have a larger modulatory effect on the spinal circuits. The two different configurations are: 1) cathode and anode placed on the T11 vertebra and the left shoulder blade respectively (commonly used) and 2) the two electrodes placed over the spinal cord, 7 centimeters apart and centered around the 11 thoracic vertebra. TsDCS is applied on the lumbar spinal cord for a period of 15 minutes with a current of 2,5mA. The ascending part of the H-reflex recruitment curve is measured before, during and after tsDCS. We hereby present the outcome of the aforementioned study as well as the current progress of our laboratory with respect to the effect of tsDCS on the spinal circuits. We hope that our work will be able to contribute to the effectivity of tsDCS, which could possibly be applied in the rehabilitation of spinal cord injured subjects in the future

Contact force sensing in ablation of ventricular arrhythmias using a 56-hole open-irrigation catheter: a propensity-matched analysis.

PURPOSE: The effect of adding contact force (CF) sensing to 56-hole tip irrigation in ventricular arrhythmia (VA) ablation has not been previously studied. We aimed to compare outcomes with and without CF sensing in VA ablation using a 56-hole radiofrequency (RF) catheter. METHODS: A total of 164 patients who underwent first-time VA ablation using Thermocool SmartTouch Surround Flow (TC-STSF) catheter (Biosense-Webster, Diamond Bar, CA, USA) were propensity-matched in a 1:1 fashion to 164 patients who had first-time ablation using Thermocool Surround Flow (TC-SF) catheter. Patients were matched for age, gender, cardiac aetiology, ejection fraction and approach. Acute success, complications and long-term follow-up were compared. RESULTS: There was no difference between procedures utilising either TC-SF or TC-STSF in acute success (TC-SF: 134/164 (82%), TC-STSF: 141/164 (86%), p = 0.3), complications (TC-SF: 11/164 (6.7%), TC-STSF: 11/164 (6.7%), p = 1.0) or VA-free survival (TC-SF: mean arrhythmia-free survival time = 5.9 years, 95% CI = 5.4-6.4, TC-STSF: mean = 3.2 years, 95% CI = 3-3.5, log-rank p = 0.74). Fluoroscopy time was longer in normal hearts with TC-SF (19 min, IQR: 14-30) than TC-STSF (14 min, IQR: 8-25; p = 0.04). CONCLUSION: Both TC-SF and TC-STSF catheters are safe and effective in treating VAs. The use of CF sensing catheters did not improve safety or acute and long-term outcomes, but reduced fluoroscopy time in normal heart VA

Impact of Female Sex on Clinical Outcomes in the FIRE AND ICE Trial of Catheter Ablation for Atrial Fibrillation

BACKGROUND: Data on predictors of long-term clinical outcomes after catheter ablation of atrial fibrillation (AF) are limited. We sought to assess the association of baseline covariates with clinical outcomes in the 750 patients with drug-refractory paroxysmal AF enrolled in FIRE AND ICE. METHODS: In a 2-part analysis, univariate and multivariable Cox regression models were first used to identify baseline patient characteristics predictive of catheter ablation efficacy determined by the clinical end points of (1) atrial arrhythmia recurrence (primary efficacy failure), (2) cardiovascular rehospitalization, and (3) repeat ablation. Propensity score stratification methods were then used to account for differences in baseline characteristics between sexes. RESULTS: Female sex (hazard ratio [HR], 1.37; 95% confidence interval [CI], 1.08-1.73; P=0.010) and prior direct current cardioversion (HR, 1.40; 95% CI, 1.07-1.82; P=0.013) were independently associated with atrial arrhythmia recurrence. Female sex (HR, 1.36; 95% CI, 1.02-1.80; P=0.035) and hypertension (HR, 1.48; 95% CI, 1.09-2.00; P=0.013) independently predicted cardiovascular rehospitalization. A longer history of AF (HR, 1.03; 95% CI, 1.00-1.06; P=0.039) increased the rate of repeat ablation. Women continued to have higher rates of primary efficacy failure and cardiovascular rehospitalization after propensity score adjustment, with adjusted HRs of 1.51 (95% CI, 1.16-2.18; P<0.05) and 1.40 (95% CI, 1.15-2.17; P<0.05), respectively. CONCLUSIONS: After catheter ablation of paroxysmal AF, female sex was associated with an almost 40% increase in the risks of primary efficacy failure and cardiovascular rehospitalization. Primary efficacy failure was also adversely impacted by a history of direct current cardioversion, whereas hypertension had a negative impact on cardiovascular rehospitalization. History of AF was the only predictor of repeat ablation

The Implications of Sequential Investment in the Property Rights Theory of the Firm

In the property rights theory of the firm, control over assets (ownership) affords bargaining power in the case of re-negotiation, providing incentives for parties to make relationship specific investments. The models predict that property rights will be allocated so as to maximise surplus generated from investment. However, these models assume that investments are made simultaneously. In this thesis I extend the standard property-rights framework to allow for sequential investment; the model allows for two investment periods. If a party invests first (ex-ante), they sink their investment before any contracting is possible. The parties that invest second (ex-post) do so after some aspects of the project are tangible, so that they can contract on (at least some) of their investment costs. As well as being empirically relevant, sequencing has several important theoretical implications. First, if a party gets to invest second, then – ceteris paribus – it has a greater incentive to invest. Second, the investment of parties that invest first are affected by a more than one influence. Anticipating higher ex-post investment, they can have a greater incentive to increase their investments. However, higher ex-post investment leads to greater costs being borne by the ex-ante investors (via the cost sharing contracts); this reduces ex-ante incentives to invest. Overall either effect can dominate so that ex-ante investment can either increase or decrease as a result of sequential investment. Third, as noted, sequencing of investment provides the possibility to (partially) contract on ex-post investment and costs. This is an additional method of providing incentives to invest, beyond the allocation of property rights themselves. Consequently, ex-post investors can be protected (and be provided incentives to invest) via these contracts, whereas ex-ante investors –who can not contract on their investments at all – are more likely to require the protection of property rights (through the allocation of asset ownership). The addition of sequential investment alters some of the predictions of the standard models. For example, previously the literature found that if all assets are complements at the margin all agents should have access to all assets (Bel (2005)). However, when investment sequencing is possible, making a control structure more inclusive (increasing the number of agents who have access to assets) can reduce the incentives of the ex-ante investors, decreasing overall surplus; this is because increasing the property rights of ex-post investors increases the marginal costs borne by ex-ante investors, effectively reducing their claim on surplus, diminishing their incentives to invest. This result contradicts Bel (2005), and shows that even when all assets are complimentary at the margin allocating access rights can be detrimental to incentives. Furthermore, if assets are substitutes at the margin then transfer of assets from ex-ante investors to ex-post investors can increase ex-ante investment and surplus. This counter intuitive result can occur in the case when decreasing ex-post investment is necessary to provide an incentive to ex-ante investors to increase their investments.Discipline of Economic

Five-year outcome in 18 010 patients from the German Aortic Valve Registry

OBJECTIVES: To determine the 5-year outcome in patients treated by isolated transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (sAVR)—a prospective observational cohort study. METHODS: A total of 18 010 patients were included (n = 8942 TAVI and n = 9068 sAVR) in the German Aortic Valve Registry (GARY) who were treated in 2011 and 2012 at 92 sites in central Germany. Eligible patients with TAVI and sAVR were matched using propensity scores in a nearest-neighbour approach. Patients with repeat procedures or unequivocal indication for one treatment option (e.g. frailty) were excluded (n = 4785 for TAVI and n = 2 for sAVR). This led to 13 223 patients (4157 TAVI and 9066 sAVR) as an unmatched subcohort. The main outcome measure was the 5-year all-cause mortality. RESULTS: TAVI patients were significantly older (80.9 ± 6.1 vs 68.5 ± 11.1 years, P < 0.001), had a higher Society of Thoracic Surgeons (STS) score (6.3 ± 4.9 vs 2.6 ± 3.0, P < 0.001) and a higher 5-year all-cause mortality (49.8% vs 16.5%, P < 0.0001). There was no major difference in in-hospital stroke, in-hospital myocardial infarction, or temporary and chronic dialysis. In the propensity score-matched group (n = 3640), there were 763 deaths (41.9%) among 1820 TAVI patients compared with 552 (30.3%) among 1820 treated with sAVR during the 5-year follow-up (hazard ratio 1.51, 95% confidence interval 1.35–1.68; P < 0.0001). New pacemaker implantation was performed in 448 patients (24.6%) after TAVI and in 201 (11.0%) after sAVR (P < 0.0001). CONCLUSIONS: The 5-year follow-up data show that TAVI patients were significantly older and had a higher STS score than sAVR patients. After propensity score matching, TAVI with early-generation prosthesis was associated with significantly higher 5-year all-cause mortality than sAVR

Further Insight into Mechanisms of Ventricular Tachycardia from the Clinical Electrophysiology Laboratory

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72003/1/j.1540-8167.1991.tb01319.x.pd

A Comparative Assessment of Machine-Learning Techniques for Forest Degradation Caused by Selective Logging in an Amazon Region Using Multitemporal X-Band SAR Images.

Abstract: The near-real-time detection of selective logging in tropical forests is essential to support actions for reducing CO2 emissions and for monitoring timber extraction from forest concessions in tropical regions. Current operating systems rely on optical data that are constrained by persistent cloud-cover conditions in tropical regions. Synthetic aperture radar data represent an alternative to this technical constraint. This study aimed to evaluate the performance of three machine learning algorithms applied to multitemporal pairs of COSMO-SkyMed images to detect timber exploitation in a forest concession located in the Jamari National Forest, Rondônia State, Brazilian Amazon. The studied algorithms included random forest (RF), AdaBoost (AB), and multilayer perceptron artificial neural network (MLP-ANN). The geographical coordinates (latitude and longitude) of logged trees and the LiDAR point clouds before and after selective logging were used as ground truths. The best results were obtained when the MLP-ANN was applied with 50 neurons in the hidden layer, using the ReLu activation function and SGD weight optimizer, presenting 88% accuracy both for the pair of images used for training (images acquired in June and October) of the network and in the generalization test, applied on a second dataset (images acquired in January and June). This study showed that X-band SAR images processed by applying machine learning techniques can be accurately used for detecting selective logging activities in the Brazilian Amazon

A complex proinflammatory cascade mediates the activation of HSCs upon LPS exposure in vivo

Infections are a key source of stress to the hematopoietic system. While infections consume short-lived innate immune cells, their recovery depends on quiescent hematopoietic stem cells (HSCs) with long-term self-renewal capacity. Both chronic inflammatory stress and bacterial infections compromise competitive HSC capacity and cause bone marrow failure. However, our understanding of how HSCs act during acute and contained infections remains incomplete. Here, we used advanced chimeric and genetic mouse models in combination with pharmacological interventions to dissect the complex nature of the acute systemic response of HSCs to lipopolysaccharide (LPS), a well-established model for inducing inflammatory stress. Acute LPS challenge transiently induced proliferation of quiescent HSCs in vivo. This response was not only mediated via direct LPS-TLR4 conjugation on HSCs, but also involved indirect TLR4 signaling in CD115+ monocytic cells, inducing a complex pro-inflammatory cytokine cascade in the bone marrow. Downstream of LPS-TLR4 signaling, the combined action of pro-inflammatory cytokines such as IFNα, IFNγ, TNFα, IL-1α, IL-1β and many others is required to mediate full HSC activation in vivo. Together, our study reveals detailed mechanistic insights into the interplay of proinflammatory cytokine-induced molecular pathways and cell types that jointly orchestrate the complex process of emergency hematopoiesis and HSC activation upon LPS exposure in vivo