Between 1983 and 2005, continuous oceanic CO2 observations at two time series sites in the North Atlantic Ocean near Bermuda indicate that surface seawater dissolved inorganic carbon (DIC) and pCO2 ...increased annually at rates similar to that expected from oceanic equilibration with increasing CO2 in the atmosphere. In addition, seawater pH, CO32− ion concentrations, and CaCO3 saturation states have also decreased over time. There was considerable seasonal asymmetry in the oceanic CO2 sink or source rates, with wintertime air‐to‐sea CO2 influx greater than the summertime sea‐to‐air CO2 efflux. On an annual basis, the region was an oceanic sink for CO2, with a mean net annual air‐sea CO2 flux rate of −815 ± 251 and −1295 ± 294 mmol CO2 m−2 yr−1, respectively, estimated using different synoptic and data assimilation model wind speed data sets. Peak‐to‐peak variability of ∼850–1950 mmol CO2 m−2 yr−1 represented an interannual variability of ∼0.2–0.3 Pg C yr−1 in the oceanic CO2 sink scaled to the subtropical gyre of North Atlantic Ocean. The long‐term trend over the 1983–2005 period was a slight increase in the oceanic CO2 sink, associated primarily with a gradual increase in wind speed over the same period. Interannual variability of summertime (June–September) and fall (October–December) air‐sea CO2 flux rates were correlated to the North Atlantic Oscillation (NAO) and strongly influenced by wind events such as hurricanes. Wintertime (January–May) air‐sea CO2 flux rates were poorly correlated with the NAO and Arctic Oscillation (AO), although gas exchange rates were ∼11–40% higher during concurrent El Niño periods compared to La Niña periods.
The executive summary of the American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions coronary artery revascularization guideline provides ...the top 10 items readers should know about the guideline. In the full guideline, the recommendations replace the 2011 coronary artery bypass graft surgery guideline and the 2011 and 2015 percutaneous coronary intervention guidelines. This summary offers a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization, as well as the supporting documentation to encourage their use.
A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered. Structure: Recommendations from the earlier percutaneous coronary intervention and coronary artery bypass graft surgery guidelines have been updated with new evidence to guide clinicians in caring for patients undergoing coronary revascularization. This summary includes recommendations, tables, and figures from the full guideline that relate to the top 10 take-home messages. The reader is referred to the full guideline for graphical flow charts, supportive text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in the development of this guideline.
Controlling monkeypox effectively requires clinicians have knowledge of monkeypox, attitudes supporting of controlling it, and intentions to adopt practices to address it. Little is known, however, ...about levels of knowledge, attitudes, and practices (KAPs) in clinician populations in Ohio, United States.
A cross-sectional, internet-based questionnaire assessed knowledge related to monkeypox, attitudes toward ability to control monkeypox and the threat of monkeypox, and prior relevant practices of having received a smallpox vaccine or having knowledge of monkeypox before 2022, intentions to adopt preventive practices, and demographics. Frequency reporting was used to assess overall knowledge and attitudes. Binary logistic regression was used to predict which KAPs were associated with behavioral intentions.
A total of 197 clinicians participated. No demographic factor was associated with KAPs. Clinicians had relatively poor levels of knowledge. Participants expressed mixed attitudes about eventual control of monkeypox and about threat posed by monkeypox. About one in four participants reported previous knowledge of monkeypox, and about 40 % had received a smallpox vaccine Clinicians reported insufficient levels of intention to adopt preventive practices. Binary regression analysis suggests only perceptions of the threat of monkeypox to public health were associated with intentions to vaccinate self or others.
Educational interventions with clinicians should address inadequate knowledge to support correct diagnosis and treatment. Efforts to enhance the perception of threat of monkeypox to public health may support adherence to preventive recommendations.
The mitochondrial ATP synthase emerges as key hub of cellular functions controlling the production of ATP, cellular signaling, and fate. It is regulated by the ATPase inhibitory factor 1 (IF1), which ...is highly abundant in neurons. Herein, we ablated or overexpressed IF1 in mouse neurons to show that IF1 dose defines the fraction of active/inactive enzyme in vivo, thereby controlling mitochondrial function and the production of mitochondrial reactive oxygen species (mtROS). Transcriptomic, proteomic, and metabolomic analyses indicate that IF1 dose regulates mitochondrial metabolism, synaptic function, and cognition. Ablation of IF1 impairs memory, whereas synaptic transmission and learning are enhanced by IF1 overexpression. Mechanistically, quenching the IF1-mediated increase in mtROS production in mice overexpressing IF1 reduces the increased synaptic transmission and obliterates the learning advantage afforded by the higher IF1 content. Overall, IF1 plays a key role in neuronal function by regulating the fraction of ATP synthase responsible for mitohormetic mtROS signaling.
COVID-19 threatens health systems worldwide, but Venezuela's system is particularly vulnerable. To prevent the spread of COVID-19, individuals must adopt preventive behaviors. However, to encourage ...behavior change, we must first understand current knowledge, attitudes, and practices (KAPs) that inform response to this health threat.
We explored KAPs among Venezuelans using a cross-sectional, internet-based questionnaire. The questionnaire explored individuals' knowledge about COVID-19; their attitudes toward the world's and the Venezuelan authorities' abilities to control it; and their self-reported practices. We also collected demographic data. Binomial logistic regression analyses were used to predict the adoption of preventive behaviors based on demographic variables, individual knowledge level, and individual attitudes.
3122 individuals completed the questionnaire. Participants had a high level of knowledge about COVID-19. They expressed high levels of optimism that the world would eventually control COVID-19, but they were very pessimistic about the public authorities in Venezuela. Most participants adopted preventive practices. Binomial regression suggests younger people, less educated people, and manual laborers hold lower levels of knowledge, and these groups, as well as men, were less likely to adopt preventive practices. Knowledge, by itself, had no association with optimism and little association with self-reported practices.
As other KAP studies in Latin America found, knowledge is not sufficient to prompt behavior change. Venezuelans' pessimism about their own country's ability should be explored in greater depth. Health promotion in Venezuela may wish to target the most at risk groups: men, younger people, less educated people, and manual laborers.
Life on the margin Andersson, Andreas J.; Mackenzie, Fred T.; Bates, Nicholas R.
Marine ecology. Progress series,
12/2008, Letnik:
373
Journal Article
Recenzirano
Odprti dostop
Future anthropogenic emissions of CO₂ and the resulting ocean acidification may have severe consequences for marine calcifying organisms and ecosystems. Marine calcifiers depositing calcitic hard ...parts that contain significant concentrations of magnesium, i.e. Mg-calcite, and calcifying organisms living in high latitude and/or cold-water environments are at immediate risk to ocean acidification and decreasing seawater carbonate saturation because they are currently immersed in seawater that is just slightly supersaturated with respect to the carbonate phases they secrete. Under the present rate of CO₂ emissions, model calculations show that high latitude ocean waters could reach undersaturation with respect to aragonite in just a few decades. Thus, before this happens these waters will be undersaturated with respect to Mg-calcite minerals of higher solubility than that of aragonite. Similarly, tropical surface seawater could become undersaturated with respect to Mgcalcite minerals containing ≥12 mole percent (mol%) MgCO₃ during this century. As a result of these changes in surface seawater chemistry and further penetration of anthropogenic CO₂ into the ocean interior, we suggest that (1) the magnesium content of calcitic hard parts will decrease in many ocean environments, (2) the relative proportion of calcifiers depositing stable carbonate minerals, such as calcite and low Mg-calcite, will increase and (3) the average magnesium content of carbonate sediments will decrease. Furthermore, the highest latitude and deepest depth at which cold-water corals and other calcifiers currently exist will move towards lower latitudes and shallower depth, respectively. These changes suggest that anthropogenic emissions of CO₂ may be currently pushing the oceans towards an episode characteristic of a ‘calcite sea.’
Ocean ecosystem models predict that warming and increased surface ocean stratification will trigger a series of ecosystem events, reducing the biological export of particulate carbon to the ocean ...interior. We present a nearly three-decade time series from the open ocean that documents a biological response to ocean warming and nutrient reductions wherein particulate carbon export is maintained, counter to expectations. Carbon export is maintained through a combination of phytoplankton community change to favor cyanobacteria with high cellular carbon-to-phosphorus ratios and enhanced shallow phosphorus recycling leading to increased nutrient use efficiency. These results suggest that surface ocean ecosystems may be more responsive and adapt more rapidly to changes in the hydrographic system than is currently envisioned in earth ecosystem models, with positive consequences for ocean carbon uptake.
The Chukchi Sea, a shallow sea‐ice covered coastal sea adjacent to the Arctic Ocean, exhibits an intense bloom of phytoplankton each year due to the exposure of nutrient‐laden surface waters during ...the brief summertime retreat and melting of sea‐ice. The impact of phytoplankton production and other factors on the seasonal dynamics of carbon and air‐sea CO2 fluxes were investigated during two survey cruises (5 May–15 June 2002, and 17 July–26 August 2002), as part of the Western Arctic Shelf‐Basins‐Interactions (SBI) project. In springtime, most of the Chukchi Sea was sea‐ice covered (>95%) and remnant winter water was present across the shelf. Surface layer seawater partial pressure of CO2 (pCO2) ranged from ∼200–320 μatm, indicative of undersaturation with respect to atmospheric pCO2, although sea‐ice cover kept rates of air‐to‐sea CO2 flux generally low (<1 mmoles CO2 m2 d−1). By summertime, after sea‐ice retreat, seawater pCO2 contents had decreased to very low values (<80–220 μatm) in response to high rates of localized primary and net community production (NCP) and biological uptake of dissolved inorganic carbon (DIC). In the seasonally sea‐ice free regions of the Chukchi Sea shelf, rates of air‐to‐sea CO2 fluxes, determined using the quadratic wind speed‐transfer velocity relationships of Wanninkhof (1992), were high, ranging from ∼30–90 mmoles CO2 m−2 d−1. In regions of the Chukchi Sea slope (and western Beaufort Sea shelf and Arctic Ocean basin) where sea‐ice cover remained high (>80%), air‐to‐sea CO2 fluxes remained generally low (<2 mmoles CO2 m−2 d−1). Seasonal (i.e., May to September) and annual net air‐to‐sea CO2 fluxes from the Chukchi Sea shelf were estimated at ∼27 ± 7 Tg C yr−1, and 38 ± 7 Tg C yr−1, respectively. The Chukchi Sea represents the largest oceanic CO2 sink in the marginal coastal seas adjacent to the Arctic Ocean. An active continental shelf pump of carbon, driven by the northward transport of nutrient‐rich water of Pacific Ocean origin, high rates of primary and net community production during the sea‐ice free period, and lateral export of organic carbon, maintains the Chukchi Sea shelf and slope as a perennial ocean CO2 sink.
Ticagrelor is a platelet P2Y
receptor inhibitor approved for use in patients with acute coronary syndromes, coronary artery disease, and low-moderate risk acute ischemic stroke or high-risk transient ...ischemic attack. Clinical trials have evaluated the efficacy and safety of ticagrelor on ischemic and bleeding outcomes for different indications and with varying treatment approaches. As a result, there is a large body of clinical evidence demonstrating different degrees of net clinical benefit compared with other platelet inhibitor drugs based on indication, patient characteristics, clinical presentation, treatment duration, and other factors. We provide a review of the major trials of ticagrelor in the context of other randomized trials of clopidogrel and prasugrel to organize the volume of available information, elevate corroborating and conflicting data, and identify potential gaps as areas for further exploration of optimal antiplatelet treatment.
We conducted a randomized, controlled trial of circumferential pulmonary-vein ablation for the treatment of chronic atrial fibrillation.
A total of 146 patients with a mean (+/-SD) age of 57+/-9 ...years who had chronic atrial fibrillation were randomly assigned to receive amiodarone and undergo two cardioversions during the first three months alone (the control group) or in combination with circumferential pulmonary-vein ablation. Cardiac rhythm was assessed with daily telephonic transmissions for one year. The left atrial diameter and the severity of symptoms were assessed at 12 months.
Among the 77 patients assigned to undergo circumferential pulmonary-vein ablation, ablation was repeated because of recurrent atrial fibrillation in 26 percent of patients and atypical atrial flutter in 6 percent. An intention-to-treat analysis showed that 74 percent of patients in the ablation group and 58 percent of those in the control group were free of recurrent atrial fibrillation or flutter without antiarrhythmic-drug therapy at one year (P=0.05). Among the 69 patients in the control group, 53 (77 percent) crossed over to undergo circumferential pulmonary-vein ablation for recurrent atrial fibrillation by one year and only 3 (4 percent) were in sinus rhythm without antiarrhythmic-drug therapy or ablation. There were significant decreases in the left atrial diameter (12+/-11 percent, P<0.001) and the symptom severity score (59+/-21 percent, P<0.001) among patients who remained in sinus rhythm after circumferential pulmonary-vein ablation. Except for atypical atrial flutter, there were no complications attributable to circumferential pulmonary-vein ablation.
Sinus rhythm can be maintained long term in the majority of patients with chronic atrial fibrillation by means of circumferential pulmonary-vein ablation independently of the effects of antiarrhythmic-drug therapy, cardioversion, or both. The maintenance of sinus rhythm is associated with a significant decrease in both the severity of symptoms and the left atrial diameter.