45 research outputs found
Taking the Metabolic Pulse of the World\u27s Coral Reefs
Worldwide, coral reef ecosystems are experiencing increasing pressure from a variety of anthropogenic perturbations including ocean warming and acidification, increased sedimentation, eutrophication, and overfishing, which could shift reefs to a condition of net calcium carbonate (CaCO3) dissolution and erosion. Herein, we determine the net calcification potential and the relative balance of net organic carbon metabolism (net community production; NCP) and net inorganic carbon metabolism (net community calcification; NCC) within 23 coral reef locations across the globe. In light of these results, we consider the suitability of using these two metrics developed from total alkalinity (TA) and dissolved inorganic carbon (DIC) measurements collected on different spatiotemporal scales to monitor coral reef biogeochemistry under anthropogenic change. All reefs in this study were net calcifying for the majority of observations as inferred from alkalinity depletion relative to offshore, although occasional observations of net dissolution occurred at most locations. However, reefs with lower net calcification potential (i.e., lower TA depletion) could shift towards net dissolution sooner than reefs with a higher potential. The percent influence of organic carbon fluxes on total changes in dissolved inorganic carbon (DIC) (i.e., NCP compared to the sum of NCP and NCC) ranged from 32% to 88% and reflected inherent biogeochemical differences between reefs. Reefs with the largest relative percentage of NCP experienced the largest variability in seawater pH for a given change in DIC, which is directly related to the reefs ability to elevate or suppress local pH relative to the open ocean. This work highlights the value of measuring coral reef carbonate chemistry when evaluating their susceptibility to ongoing global environmental change and offers a baseline from which to guide future conservation efforts aimed at preserving these valuable ecosystems
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ACUTE CONFUSIONAL SYNDROME FROM A DURAL ARTERIOVENOUS FISTULA
Abstract OBJECTIVE We describe a case of an acute confusional state associated with a right parietal dural arteriovenous fistula. CLINICAL PRESENTATION A 67-year-old man in his usual state of health experienced an acute confusion episode preceded by a valsalva maneuver. The episode lasted approximately 60 minutes. Afterward he was able to remember everything that occurred. A magnetic resonance imaging scan suggested a right parietal dural arteriovenous fistula, which was confirmed by angiography. A seizure was ruled out by clinical examination and an electroencephalogram. INTERVENTION The patient underwent therapeutic embolization and surgical ligation of the fistula. Feeding vessels to the malformation were cauterized within the leaves of the falx, and the draining vein was clipped with a titanium aneurysm clip and divided. An intraoperative angiogram was then performed, which showed obliteration of the fistula. There was no demonstrable confusion or memory loss noted postoperatively. CONCLUSION We propose that venous hypertension from the dural arteriovenous fistula in combination with a valsalva maneuver caused ischemia in the right parietal lobe, eliciting a deficit in attention
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Association of Low Ejection Fraction With Impaired Verbal Memory in Older Patients With Heart Failure
COVID-19 responses restricted abilities and aspirations for mobility and migration: insights from diverse cities in four continents
Abstract Research on the impacts of COVID-19 on mobility has focused primarily on the increased health vulnerabilities of involuntary migrant and displaced populations. But virtually all migration flows have been truncated and altered because of reduced economic and mobility opportunities of migrants. Here we use a well-established framework of migration decision-making, whereby individual decisions combine the aspiration and ability to migrate, to explain how public responses to the COVID-19 pandemic alter migration patterns among urban populations across the world. The principal responses to COVID-19 pandemic that affected migration are: 1) through travel restrictions and border closures, 2) by affecting abilities to move through economic and other means, and 3) by affecting aspirations to move. Using in-depth qualitative data collected in six cities in four continents (Accra, Amsterdam, Brussels, Dhaka, Maputo, and Worcester), we explore how populations with diverse levels of education and occupations were affected in their current and future mobility decisions. We use data from interviews with sample of internal and international migrants and non-migrants during the 2020 COVID-19 pandemic outbreak to identify the mechanisms through which the pandemic affected their mobility decisions. The results show common processes across the different geographical contexts: individuals perceived increased risks associated with further migration, which affected their migration aspirations, and had reduced abilities to migrate, all of which affected their migration decision-making processes. The results also reveal stark differences in perceived and experienced migration decision-making across precarious migrant groups compared to high-skilled and formally employed international migrants in all settings. This precarity of place is particularly evident in low-income marginalised populations
Psychosocial stress and cigarette smoking persistence, cessation, and relapse over 9–10 years: a prospective study of middle-aged adults in the United States
PURPOSE: Year-to-year decreases in smoking in the US have been observed only sporadically in recent years, which suggest a need for intensified efforts to identify those at risk for persistent smoking. To address this need, we examined the association between a variety of psychosocial stressors and smoking persistence, cessation, and relapse over 9–10 years among adults in the United States (N=4938, ages 25–74). METHODS: Using information provided at baseline and follow-up, participants were categorized as non-smokers, persistent smokers, ex-smokers, and relapsed smokers. Stressors related to relationships, finances, work-family conflict, perceived inequality, neighborhood, discrimination, and past-year family problems were assessed at baseline and follow-up. RESULTS: High stress at both assessments was associated with greater odds of persistent smoking for stressors related to relationships, finances, work, perceived inequality, past-year family problems, and a summary score. Among respondents who were smokers at baseline, high stress at both time-points for relationship stress, perceived inequality, and past-year family problems was associated with nearly double the odds of failure to quit. CONCLUSIONS: Interventions to address psychosocial stress may be important components within smoking cessation efforts
Taking the metabolic pulse of the world’s coral reefs
<div><p>Worldwide, coral reef ecosystems are experiencing increasing pressure from a variety of anthropogenic perturbations including ocean warming and acidification, increased sedimentation, eutrophication, and overfishing, which could shift reefs to a condition of net calcium carbonate (CaCO<sub>3</sub>) dissolution and erosion. Herein, we determine the net calcification potential and the relative balance of net organic carbon metabolism (net community production; NCP) and net inorganic carbon metabolism (net community calcification; NCC) within 23 coral reef locations across the globe. In light of these results, we consider the suitability of using these two metrics developed from total alkalinity (TA) and dissolved inorganic carbon (DIC) measurements collected on different spatiotemporal scales to monitor coral reef biogeochemistry under anthropogenic change. All reefs in this study were net calcifying for the majority of observations as inferred from alkalinity depletion relative to offshore, although occasional observations of net dissolution occurred at most locations. However, reefs with lower net calcification potential (i.e., lower TA depletion) could shift towards net dissolution sooner than reefs with a higher potential. The percent influence of organic carbon fluxes on total changes in dissolved inorganic carbon (DIC) (i.e., NCP compared to the sum of NCP and NCC) ranged from 32% to 88% and reflected inherent biogeochemical differences between reefs. Reefs with the largest relative percentage of NCP experienced the largest variability in seawater pH for a given change in DIC, which is directly related to the reefs ability to elevate or suppress local pH relative to the open ocean. This work highlights the value of measuring coral reef carbonate chemistry when evaluating their susceptibility to ongoing global environmental change and offers a baseline from which to guide future conservation efforts aimed at preserving these valuable ecosystems.</p></div