Geomagnetic activity forcing of the Northern Annular Mode via the stratosphere

We consider various aspects of the link between solar-modulated geomagnetic activity and the Northern Annular Mode (NAM). Our results indicate that the geomagnetic forcing of atmospheric circulation in the Northern Hemisphere is temporally and seasonally restricted, modulated by the Quasi-Biennial Oscillation (QBO), and reliant on stratosphere-troposphere coupling. When the data are restricted to January values after 1965, for years in which the January QBO is eastwards, the correlation coefficient between the geomagnetic AA index and the NAM is 0.85. These results can account for many of the enigmatic features of Northern Hemisphere circulation.<br><br> <b>Key words.</b> Meterology and atmospheric dynamics (general circulation, climatology

Role of glutathionylation in infection and inflammation

Glutathionylation, that is, the formation of mixed disulfides between protein cysteines and glutathione (GSH) cysteines, is a reversible post-translational modification catalyzed by dierent cellular oxidoreductases, by which the redox state of the cell modulates protein function. So far, most studies on the identification of glutathionylated proteins have focused on cellular proteins, including proteins involved in host response to infection, but there is a growing number of reports showing that microbial proteins also undergo glutathionylation, with modification of their characteristics and functions. In the present review, we highlight the signaling role of GSH through glutathionylation, particularly focusing on microbial (viral and bacterial) glutathionylated proteins (GSSPs) and host GSSPs involved in the immune/inflammatory response to infection; moreover, we discuss the biological role of the process in microbial infections and related host responses

An evaluation of airborne laser scan data for coalmine subsidence mapping

The accurate mapping of coalmine subsidence is necessary for the continued management of potential subsidence impacts. The use of airborne laser scan (ALS) data for subsidence mapping provides an alternative method to traditional ground-based approaches that affords increased accessibility and complete spatial coverage. This paper evaluates the suitability and potential of ALS data for subsidence mapping, primarily through the examination of two pre-mining surveys in a rugged, densely vegetated study site. Data quality, in terms of mean point spacing and coverage, is evaluated, along with the impact of interpolation methods, resolution, and terrain. It was assumed that minimal surface height changes occurred between the two pre-mining surfaces. Therefore any height changes between digital elevation models of the two ALS surveys were interpreted as errors associated with the use of ALS data for subsidence mapping. A mean absolute error of 0.23 m was observed, though this error may be exaggerated by the presence of a systematic 0.15 m offset between the two surveys. Very large (several metres) errors occur in areas of steep or dynamic terrain, such as along cliff lines and watercourses. Despite these errors, preliminary subsidence mapping, performed using a third, post-mining dataset, clearly demonstrates the potential benefits of ALS data for subsidence mapping, as well as some potential limitations and the need for further careful assessment and validation concerning data errors

Electrophysiology Model for a Human Heart with Ischemic Scar and Realistic Purkinje Network

The role of Purkinje fibres in the onset of arrhythmias is controversial and computer simulations may shed light on possible arrhythmic mechanisms involving the Purkinje fibres. However, few computational modelling studies currently include a detailed Purkinje network as part of the model. We present a coupled Purkinje-myocardium electrophysiology model that includes an explicit model for the ischemic scar plus a detailed Purkinje network, and compare simulated activation times to those obtained by electro-anatomical mapping in vivo during sinus rhythm pacing. The results illustrate the importance of using sufficiently dense Purkinje networks in patient-specific studies to capture correctly the myocardial early activation that may be influenced by surviving Purkinje fibres in the infarct region

Efficient Numerical Schemes for Computing Cardiac Electrical Activation over Realistic Purkinje Networks: Method and Verification

We present a numerical solver for the fast conduction system in the heart using both a CPU and a hybrid CPU/GPU implementation. To verify both implementations, we construct analytical solutions and show that the L2-error is similar in both implementations and decreases linearly with the spatial step size. Finally, we test the performance of the implementations with networks of varying complexity, where the hybrid implementation is, on average, 5.8 times faster

GSH-C4 acts as anti-inflammatory drug in different models of canonical and cell autonomous inflammation through NFκB inhibition

An imbalance in GSH/GSSG ratio represents a triggering event in pro-inflammatory cytokine production and inflammatory response. However, the molecular mechanism(s) through which GSH regulates macrophage and cell autonomous inflammation remains not deeply understood. Here, we investigated the effects of a derivative of GSH, the N-butanoyl glutathione (GSH-C4), a cell permeable compound, on lipopolisaccharide (LPS)-stimulated murine RAW 264.7 macrophages, and human macrophages. LPS alone induces a significant production of pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α and a significant decrement of GSH content. Such events were significantly abrogated by treatment with GSH-C4. Moreover, GSH-C4 was highly efficient in buffering cell autonomous inflammatory status of aged C2C12 myotubes and 3T3-L1 adipocytes by suppressing the production of pro-inflammatory cytokines. We found that inflammation was paralleled by a strong induction of the phosphorylated form of NFκB, which translocates into the nucleus; a process that was also efficiently inhibited by the treatment with GSH-C4. Overall, the evidence suggests that GSH decrement is required for efficient activation of an inflammatory condition and, at the same time, GSH-C4 can be envisaged as a good candidate to abrogate such process, expanding the anti-inflammatory role of this molecule in chronic inflammatory states