FLUXNET comprises globally distributed eddy-covariance-based estimates of carbon fluxes between the biosphere and the atmosphere. Since eddy covariance flux towers have a relatively small footprint ...and are distributed unevenly across the world, upscaling the observations is necessary to obtain global-scale estimates of biosphere-atmosphere exchange. Based on cross-consistency checks with atmospheric inversions, sun-induced fluorescence (SIF) and dynamic global vegetation models (DGVMs), here we provide a systematic assessment of the latest upscaling efforts for gross primary production (GPP) and net ecosystem exchange (NEE) of the FLUXCOM initiative, where different machine learning methods, forcing data sets and sets of predictor variables were employed.
We consider dissipativity properties of interconnected systems in the context of distributed economic model predictive control (MPC), with the subsystems being interconnected through their stage cost ...functions. The isolated subsystems, i.e., when neglecting the coupled portion of the individual stage costs, are assumed to be dissipative with respect to a specific supply rate related to their local stage cost function, which is commonly used in an economic MPC context. Based on these local dissipativity properties and the interconnection structure, a corresponding (approximate) dissipativity property for the overall system is inferred, which is structured and provides performance bounds for overall system operation. The resulting structured dissipativity property is exploited in the design and analysis of a distributed economic MPC algorithm. Numerical examples visualize the theoretical findings and the effectiveness of the proposed algorithm.
Heater-cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical ...field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
First global retrievals of sun-induced chlorophyll fluorescence (F 8 ) have been achieved in the last years by using data from the Fourier transform spectrometer (FTS) onboard the Japanese Greenhouse ...Gases Observing Satellite (GOSAT). The high spectral resolution (approximately 0.025 nm) of the FTS enables measurements of F 8 by the evaluation of the in-filling of solar Fraunhofer lines around 755 nm. This study presents a new F 8 retrieval algorithm (GARLiC, for GOSAT retrieval of chlorophyll fluorescence) and compares its results to F 8 from two previously implemented approaches. GARLiC is intended to simplify some of the assumptions of existing retrieval approaches without a loss in retrieval accuracy. We show that GARLiC F 8 retrievals are comparable to the previously used methods. We also assess the effect of clouds on F 8 retrieval from GOSAT data through the analysis of the effect of different cloud filter thresholds on F 8 time series. Our results show a low sensitivity of Fraunhofer-line-based F 8 retrievals to cloud contamination.
Invasive fungal infections are gaining increasing importance in intensive care medicine. The aim of this article is to present an update on recent developments in the field of invasive fungal ...infection in critically ill patients. Particular emphasis is placed on the recently described invasive mold infections in patients with acute respiratory distress syndrome due to influenza or COVID-19. Detecting high-risk patients and the optimal diagnostic and therapeutic strategies play a decisive role to improve outcome.
Glacial algae blooms on the Greenland ice sheet darken the surface albedo, enhancing surface melt. Sentinel-3 data was the first to highlight the extent of these blooms, which are expected to become ...larger as climate changes. Here we propose a novel use of solar-induced chlorophyll fluorescence (SIF) data from TROPOMI to confirm the Sentinel-based maps and extend the data to daily levels to understand year-to-year variations in algae blooms. We combine the SIF data with a random walker algorithm to identify algae-covered areas. The SIF-based maps are found to be highly correlated with the Sentinel-based ones. The extent and the timing of the algae bloom are consistent between 2018 and 2020. This work opens the door to a new, complementary method for the monitoring of algae blooms on ice sheets and improving our understanding of their impact on glacier melt rate.
Production of TNF-α and IL-1 in infectious and autoimmune diseases is associated with fever, fatigue, and sleep disturbances, which are collectively referred to as sickness behavior syndrome. In mice ...TNF-α and IL-1 increase nonrapid eye movement sleep. Because clock genes regulate the circadian rhythm and thereby locomotor activity and may alter sleep architecture we assessed the influence of TNF-α on the circadian timing system. TNF-α is shown here to suppress the expression of the PAR bZip clock-controlled genes Dbp, Tef, and Hlf and of the period genes Per1, Per2, and Per3 in fibroblasts in vitro and in vivo in the liver of mice infused with the cytokine. The effect of TNF-α on clock genes is shared by IL-1β, but not by IFN-α, and IL-6. Furthermore, TNF-α interferes with the expression of Dbp in the suprachiasmatic nucleus and causes prolonged rest periods in the dark when mice show spontaneous locomotor activity. Using clock reporter genes TNF-α is found here to inhibit CLOCK-BMAL1-induced activation of E-box regulatory elements-dependent clock gene promoters. We suggest that the increase of TNF-α and IL-1β, as seen in infectious and autoimmune diseases, impairs clock gene functions and causes fatigue.
BACKGROUND Mortality associated with infections caused by carbapenem-resistant Enterobacteriaceae (CRE) is higher than mortality due to carbapenem-sensitive pathogens. OBJECTIVE To examine the ...association between mortality from bacteremia caused by carbapenem-resistant (CRKP) and carbapenem-sensitive Klebsiella pneumoniae (CSKP) and to assess the impact of appropriate initial antibiotic therapy (IAT) on mortality. DESIGN Systematic review and meta-analysis METHODS We searched MEDLINE, EMBASE, CINAHL, and Wiley Cochrane databases through August 31, 2016, for observational studies reporting mortality among adult patients with CRKP and CSKP bacteremia. Search terms were related to Klebsiella, carbapenem-resistance, and infection. Studies including fewer than 10 patients per group were excluded. A random-effects model and meta-regression were used to assess the relationship between carbapenem-resistance, appropriateness of IAT, and mortality. RESULTS Mortality was higher in patients who had CRKP bacteremia than in patients with CSKP bacteremia (15 studies; 1,019 CRKP and 1,148 CSKP patients; unadjusted odds ratio OR, 2.2; 95% confidence interval CI, 1.8-2.6; I2=0). Mortality was lower in patients with appropriate IAT than in those without appropriate IAT (7 studies; 658 patients; unadjusted OR, 0.5; 95% CI, 0.3-0.8; I2=36%). CRKP patients (11 studies; 1,326 patients; 8-year period) were consistently less likely to receive appropriate IAT (unadjusted OR, 0.5; 95% CI, 0.3-0.7; I2=43%). Our meta-regression analysis identified a significant association between the difference in appropriate IAT and mortality (OR per 10% difference in IAT, 1.3; 95% CI, 1.0-1.6). CONCLUSIONS Appropriateness of IAT is an important contributor to the observed difference in mortality between patients with CRKP bacteremia and patients with CSKP bacteremia. Infect Control Hosp Epidemiol 2017;38:1319-1328.
Gross primary productivity (GPP) is the sum of leaf photosynthesis and represents a crucial component of the global carbon cycle. Space-borne estimates of GPP typically rely on observable quantities ...that co-vary with GPP such as vegetation indices using reflectance measurements (e.g., normalized difference vegetation index, NDVI, near-infrared reflectance of terrestrial vegetation, NIRv, and kernel normalized difference vegetation index, kNDVI). Recent work has also utilized measurements of solar-induced chlorophyll fluorescence (SIF) as a proxy for GPP. However, these SIF measurements are typically coarse resolution, while many processes influencing GPP occur at fine spatial scales. Here, we develop a convolutional neural network (CNN), named SIFnet, that increases the resolution of SIF from the TROPOspheric Monitoring Instrument (TROPOMI) on board of the satellite Sentinel-5P by a factor of 10 to a spatial resolution of 500 m. SIFnet utilizes coarse SIF observations together with high-resolution auxiliary data. The auxiliary data used here may carry information related to GPP and SIF. We use training data from non-US regions between April 2018 until March 2021 and evaluate our CNN over the conterminous United States (CONUS). We show that SIFnet is able to increase the resolution of TROPOMI SIF by a factor of 10 with a r2 and RMSE metrics of 0.92 and 0.17 mW m−2 sr−1 nm−1, respectively. We further compare SIFnet against a recently developed downscaling approach and evaluate both methods against independent SIF measurements from Orbiting Carbon Observatory 2 and 3 (together OCO-2/3). SIFnet performs systematically better than the downscaling approach (r=0.78 for SIFnet, r=0.72 for downscaling), indicating that it is picking up on key features related to SIF and GPP. Examination of the feature importance in the neural network indicates a few key parameters and the spatial regions in which these parameters matter. Namely, the CNN finds low-resolution SIF data to be the most significant parameter with the NIRv vegetation index as the second most important parameter. NIRv consistently outperforms the recently proposed kNDVI vegetation index. Advantages and limitations of SIFnet are investigated and presented through a series of case studies across the United States. SIFnet represents a robust method to infer continuous, high-spatial-resolution SIF data.
The first total synthesis of a chromodorolide marine diterpenoid is described. The core of the diterpenoid is constructed by a bimolecular radical addition/cyclization/fragmentation cascade that ...unites two complex fragments and forms two C–C bonds and four contiguous stereogenic centers of (−)-chromodorolide B in a single step. This coupling step is initiated by visible-light photocatalytic fragmentation of a redox-active ester, which can be accomplished in the presence of an iridium or a less-precious electron-rich dicyanobenzene photocatalyst, and employs equimolar amounts of the two addends. Computational studies guided the development of this central step of the synthesis and provide insight into the origin of the observed stereoselectivity.
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