Correlation between tectonic CO2 Earth degassing and seismicity is revealed by a 10-year record in the Apennines, Italy.

Deep CO2 emissions characterize many nonvolcanic, seismically active regions worldwide, and the involvement of deep CO2 in the earthquake cycle is now generally recognized. However, no long-time records of such emissions have been published, and the temporal relations between earthquake occurrence and tectonic CO2 release remain enigmatic. Here, we report a 10-year record (2009-2018) of tectonic CO2 flux in the Apennines (Italy) during intense seismicity. The gas emission correlates with the evolution of the seismic sequences: Peaks in the deep CO2 flux are observed in periods of high seismicity and decays as the energy and number of earthquakes decrease. We propose that the evolution of seismicity is modulated by the ascent of CO2 accumulated in crustal reservoirs and originating from the melting of subducted carbonates. This large-scale, continuous process of CO2 production favors the formation of overpressurized CO2-rich reservoirs potentially able to trigger earthquakes at crustal depth.

PaTre: a method for paralogy trees construction.

Genomes can be described as a collection of clusters, the gene families, whose members are called paralogs. Paralogs are genes that most probably share duplication history and show a significant similarity in their sequences, even if they perform slightly different biological function. Among the different mechanisms that have led to an increase of the genomic information during biological evolution, gene duplication is probably the most important. To better understand duplication events, the first step is to investigate the history of the gene families in order to detect which duplication events have taken place, and in which relative (partial) order. Here we present a method, called PaTre, that, given a gene family, attempts to construct the paralogy tree of the family. We will work under the hypothesis that every family member derives from a duplication process of another member. By the term paralogy tree, we mean a directed tree in which the root represents the most ancient paralog of the family and each oriented arc (a, b) represents the existence of a duplication event from the template gene a to its copy b. Notice that gene a survives the event and can serve as a template of more than one duplication event; in fact, there can be more than one arc leaving a. PaTre uses new algorithmic techniques motivated by the specific application at hand. The reliability of the inferential process has been tested by means of a simulator that implements different hypotheses on the duplication-with-modification paradigm and on three examples of different biological gene families, belonging either to lower and higher organisms.

Intraperitoneal hydrostatic pressure and volume in peritoneal dialysis patients.

Dialysate Intraperitoneal Volume (IPV) represents one of the major determinants of Peritoneal Dialysis (PD) efficiency, but most adult patients are currently treated with the same standard IPV, regardless of body size. In order to evaluate the tolerability of different IPV, we adapted the current connection in use at our Institution to produce a simple method to directly measure Intraperitoneal Hydrostatic Pressure (IPP). We studied the relationship between IPV and IPP in 30 adult (age 19-77 years) patients (19 males) of various body sizes, on PD between 17 +/- 17 months. Mean end-inspiratory and end-expiratory IPP with different IPV were measured in each patient in the IPV range of clinical interest. A total of 210 individual measurements showed a statistically significant positive relationship between BSA-normalised IPV and IPP (r = 0.355, p < 0.001). Interpatient variability was high, thus suggesting that individualization of IPV according to body size is not accurate, IPP being often higher in larger body size. Direct IPP measurement with different IPV in the single patient is a simple, safe and reproducible procedure, allowing an individually tailored IPV prescription which should optimise PD efficiency while monitoring for IPP related complications.