9 research outputs found
Recommended from our members
Multidecadal Climate Variability in the Southern Region of the California Current System During the Last 1,800 Years
How climate warming is going to affect the multidecadal climate variability in the North Pacific remains an open question. Here we present a record of this type of variability inferred from carbon productivity and sea surface temperature (SST) proxies in high-resolution sediment records from the Southern California Current System (CCS). The reconstruction covers similar to 1,800 years of the Common Era and is associated with the latitudinal migration of the CCS tropical boundary at multidecadal timescales. Inorganic carbon proxies and a Globigerinoides ruber Mg/Ca summer SST reconstruction are associated with the intrusion of the tropical waters in the Southern CCS and organic carbon proxies with the strength of the California Current (CC). From these and other sediment components, we derived a principal component that captures the balance between tropical and subarctic waters in the study region. This principal component record shows further connections with land moisture records, which suggests a link with Pacific basin scale climate reorganization. The results show periods of reduced Pacific multidecadal climate variability associated with cold periods in the Northern Hemisphere (NH). We propose a mechanism related with the southward migration of the westerlies during relatively cool periods in the NH and a southward shift of the North Pacific Current, which could have reduced the advection of subarctic waters to the subtropical region.Consejo Nacional de Ciencia y Tecnología, Paraguay6 month embargo; first published online 22 January 2020This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Recommended from our members
Oceanic Influence on Chiricahua Mountains Drought Observed in a 383-Year Douglas-Fir Reconstruction
Drought in the North American Southwest is a recurring phenomenon. The knowledge of drought recurrence and severity is crucial for sustainable water resource management in the region. Tree-ring reconstructions of climate variables provide valuable indirect evidence of climate variability and elucidate the relationship between large-scale circulation anomalies and the climate in the region. Here we have developed a May-July Palmer Drought Severity Index (PDSI) reconstruction from tree-ring chronologies of Pseudotsuga menziesii from the Chiricahua Mountains (southeastern Arizona) for the period 1634-2017 CE. The driest period occurred at the beginning of the 21st Century (2000-2005), followed by 1666-1670, 1952-1956, and 1729-1734. Reconstructed PDSI of the Chiricahua Mountains shows a weak correlation with the El Niño-Southern Oscillation, with intermittent influence as previous studies have reported. The Pacific Decadal Oscillation accounts for the majority of the variability in the Chiricahua hydroclimate, except for the period from 1860-1950 when the predominant driver was the North Atlantic Oscillation.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
An 1800-year alkenone-based reconstruction of sea surface temperature from the San Lazaro (Soledad) Basin Baja California, Mexico
PCM00-78 box (C) and Kasten (KII-IV) cores were taken in the San Lazaro Basin (SLB) (sometimes referred to as the Soledad Basin) at (25° 10'N, 112° 45'W). The SLB is a suboxic fault-bounded basin 50 km offshore of the Baja California peninsula, with a surface area of ~3000 km2 and a water depth of 540 m. Weak-to-absent bioturbation promotes the preservation of laminated sediments, facilitating high-resolution SST reconstruction. Box core PCM00-78C was stratigraphically tied to Kasten core PCM00-KI via natural Pb decay and reconstructed SST measurements are reported here on a composite depth scale covering all sediment cores. Additional age control is provided by 137Cs and radiocarbon measurements (see manuscript for further details)
Prognostic assessment of valvular surgery in active infective endocarditis: multicentric nationwide validation of a new score developed from a meta-analysis
OBJECTIVES
Several risk prediction models have been developed to estimate the risk of mortality after valve surgery for active infective endocarditis (IE), but few external validations have been conducted to assess their accuracy. We previously developed a systematic review and meta-analysis of the impact of IE-specific factors for the in-hospital mortality rate after IE valve surgery, whose obtained pooled estimations were the basis for the development of a new score (APORTEI). The aim of the present study was to assess its prognostic accuracy in a nationwide cohort.
METHODS
We analysed the prognostic utility of the APORTEI score using patient-level data from a multicentric national cohort. Patients who underwent surgery for active IE between 2008 and 2018 were included. Discrimination was evaluated using the area under the receiver operating characteristic curve, and the calibration was assessed using the calibration slope and the Hosmer-Lemeshow test. Agreement between the APORTEI and the EuroSCORE I was also analysed by Lin's concordance correlation coefficient (CCC), the Bland-Altman agreement analysis and a scatterplot graph.
RESULTS
The 11 variables that comprised the APORTEI score were analysed in the sample. The APORTEI score was calculated in 1338 patients. The overall observed surgical mortality rate was 25.56%. The score demonstrated adequate discrimination (area under the receiver operating characteristic curve = 0.75; 95% confidence interval 0.72-0.77) and calibration (calibration slope = 1.03; Hosmer-Lemeshow test P = 0.389). We found a lack of agreement between the APORTEI and EuroSCORE I (concordance correlation coefficient = 0.55).
CONCLUSIONS
The APORTEI score, developed from a systematic review and meta-analysis, showed an adequate estimation of the risk of mortality after IE valve surgery in a nationwide cohort
Contemporary use of cefazolin for MSSA infective endocarditis: analysis of a national prospective cohort
Objectives: This study aimed to assess the real use of cefazolin for methicillin-susceptible Staphylococcus aureus (MSSA) infective endocarditis (IE) in the Spanish National Endocarditis Database (GAMES) and to compare it with antistaphylococcal penicillin (ASP). Methods: Prospective cohort study with retrospective analysis of a cohort of MSSA IE treated with cloxacillin and/or cefazolin. Outcomes assessed were relapse; intra-hospital, overall, and endocarditis-related mortality; and adverse events. Risk of renal toxicity with each treatment was evaluated separately. Results: We included 631 IE episodes caused by MSSA treated with cloxacillin and/or cefazolin. Antibiotic treatment was cloxacillin, cefazolin, or both in 537 (85%), 57 (9%), and 37 (6%) episodes, respectively. Patients treated with cefazolin had significantly higher rates of comorbidities (median Charlson Index 7, P <0.01) and previous renal failure (57.9%, P <0.01). Patients treated with cloxacillin presented higher rates of septic shock (25%, P = 0.033) and new-onset or worsening renal failure (47.3%, P = 0.024) with significantly higher rates of in-hospital mortality (38.5%, P = 0.017). One-year IE-related mortality and rate of relapses were similar between treatment groups. None of the treatments were identified as risk or protective factors. Conclusion: Our results suggest that cefazolin is a valuable option for the treatment of MSSA IE, without differences in 1-year mortality or relapses compared with cloxacillin, and might be considered equally effective
Prosthetic Valve Candida spp. Endocarditis: New Insights Into Long-term Prognosis—The ESCAPE Study
International audienceBackground: Prosthetic valve endocarditis caused by Candida spp. (PVE-C) is rare and devastating, with international guidelines based on expert recommendations supporting the combination of surgery and subsequent azole treatment.Methods: We retrospectively analyzed PVE-C cases collected in Spain and France between 2001 and 2015, with a focus on management and outcome.Results: Forty-six cases were followed up for a median of 9 months. Twenty-two patients (48%) had a history of endocarditis, 30 cases (65%) were nosocomial or healthcare related, and 9 (20%) patients were intravenous drug users. "Induction" therapy consisted mainly of liposomal amphotericin B (L-amB)-based (n = 21) or echinocandin-based therapy (n = 13). Overall, 19 patients (41%) were operated on. Patients <66 years old and without cardiac failure were more likely to undergo cardiac surgery (adjusted odds ratios [aORs], 6.80 [95% confidence interval [CI], 1.59-29.13] and 10.92 [1.15-104.06], respectively). Surgery was not associated with better survival rates at 6 months. Patients who received L-amB alone had a better 6-month survival rate than those who received an echinocandin alone (aOR, 13.52; 95% CI, 1.03-838.10). "Maintenance" fluconazole therapy, prescribed in 21 patients for a median duration of 13 months (range, 2-84 months), led to minor adverse effects.Conclusion: L-amB induction treatment improves survival in patients with PVE-C. Medical treatment followed by long-term maintenance fluconazole may be the best treatment option for frail patients