RESUMEN
Perseverance's Mastcam-Z instrument provides high-resolution stereo and multispectral images with a unique combination of spatial resolution, spatial coverage, and wavelength coverage along the rover's traverse in Jezero crater, Mars. Images reveal rocks consistent with an igneous (including volcanic and/or volcaniclastic) and/or impactite origin and limited aqueous alteration, including polygonally fractured rocks with weathered coatings; massive boulder-forming bedrock consisting of mafic silicates, ferric oxides, and/or iron-bearing alteration minerals; and coarsely layered outcrops dominated by olivine. Pyroxene dominates the iron-bearing mineralogy in the fine-grained regolith, while olivine dominates the coarse-grained regolith. Solar and atmospheric imaging observations show significant intra- and intersol variations in dust optical depth and water ice clouds, as well as unique examples of boundary layer vortex action from both natural (dust devil) and Ingenuity helicopter-induced dust lifting. High-resolution stereo imaging also provides geologic context for rover operations, other instrument observations, and sample selection, characterization, and confirmation.
RESUMEN
OBJECTIVE: To test whether a reduction of third generation cephalosporin (3GC) use has a sustainable positive impact on the high endemic prevalence of 3GC resistant K. pneumoniae and E. coli. DESIGN: Segmented regression analysis of interrupted time series was used to analyse antibiotic consumption and resistance data 30 months before and 30 after the intervention. SETTING: Surgical intensive care unit (ICU) with 16-bed unit in a teaching hospital. INTERVENTION: In July 2004, 3GCs were switched to piperacillin in combination with a beta-lactamase-inhibitor as standard therapy for peritonitis and other intraabdominal infections. RESULTS: Segmented regression analysis showed that the intervention achieved a significant and sustainable decrease in the use of 3GCs of -110.2 daily defined doses (DDD)/1,000 pd. 3GC use decreased from a level of 178.9 DDD/1,000 pd before to 68.7 DDD/1,000 pd after the intervention. The intervention resulted in a mean estimated reduction in total antibiotic use of 27%. Piperacillin/tazobactam showed a significant increase in level of 64.4 DDD/1,000 pd, and continued to increase by 2.3 DDD/1,000 pd per month after the intervention. The intervention was not associated with a significant change in the resistance densities of 3GC resistant K. pneumoniae and E. coli. CONCLUSION: Reducing 3GCs does not necessarily impact positively on the resistance situation in the ICU setting. Likewise, replacing piperacillin with beta-lactamase inhibitor might provide a selection pressure on 3GC resistant E. coli and K. pneumoniae. To improve resistance, it might not be sufficient to restrict interventions to a risk area.
