Pervasive subduction zone devolatilization recycles CO₂ into the forearc

The fate of subducted CO₂ remains the subject of widespread disagreement, with different models predicting either wholesale (up to 99%) decarbonation of the subducting slab or extremely limited carbon loss and, consequently, massive deep subduction of CO₂. The fluid history of subducted rocks lies at the heart of this debate: rocks that experience significant infiltration by a water-bearing fluid may release orders of magnitude more CO₂ than rocks that are metamorphosed in a closed chemical system. Numerical models make a wide range of predictions regarding water mobility, and further progress has been limited by a lack of direct observations. Here we present a comprehensive field-based study of decarbonation efficiency in a subducting slab (Cyclades, Greece), and show that ~40% to ~65% of the CO₂ in subducting crust is released via metamorphic decarbonation reactions at forearc depths. This result precludes extensive deep subduction of most CO₂ and suggests that the mantle has become more depleted in carbon over geologic time

Pervasive subduction zone devolatilization recycles CO₂ into the forearc

The fate of subducted CO₂ remains the subject of widespread disagreement, with different models predicting either wholesale (up to 99%) decarbonation of the subducting slab or extremely limited carbon loss and, consequently, massive deep subduction of CO₂. The fluid history of subducted rocks lies at the heart of this debate: rocks that experience significant infiltration by a water-bearing fluid may release orders of magnitude more CO₂ than rocks that are metamorphosed in a closed chemical system. Numerical models make a wide range of predictions regarding water mobility, and further progress has been limited by a lack of direct observations. Here we present a comprehensive field-based study of decarbonation efficiency in a subducting slab (Cyclades, Greece), and show that ~40% to ~65% of the CO₂ in subducting crust is released via metamorphic decarbonation reactions at forearc depths. This result precludes extensive deep subduction of most CO₂ and suggests that the mantle has become more depleted in carbon over geologic time

Cryptococcal choroiditis in advanced AIDS with clinicopathologic correlation.

PurposeTo describe a case of disseminated cryptococcal meningitis with multifocal choroiditis and provide optical coherence tomography (OCT) findings correlated with described histopathology in a patient with advanced acquired immunodeficiency syndrome (AIDS).ObservationsThe patient was a 54-year-old man with AIDS who presented with dyspnea and headache followed by acute vision loss. OCT demonstrated a lesion with a small area of fluid that was limited by a more prominent and irregular external limiting membrane with underlying nodular choroidal thickening, mild RPE disorganization, and hyperreflectivity of the overlying photoreceptor layer. Patient was found to have disseminated cryptococcal infection and passed away despite aggressive therapy. Autopsy was performed including bilateral enucleation and a Cryptococcus lesion was confirmed on histopathology.Conclusion and importanceThis case highlights the clinical, imaging, and histopathologic findings of cryptococcal choroiditis and provides a review of the updated treatment recommendations for disseminated infection in a patient with advanced AIDS. Although currently fundoscopy has proven most useful in directing the diagnostic algorithm in choroiditis in the setting of advanced immunosuppression, OCT may provide insight into the spread of Cryptococcus within the eye

Cardiovascular Risk Factors as Differential Predictors of Incident Atypical and Typical Major Depressive Disorder in U.S. Adults

Objectives While the association between major depressive disorder (MDD) and future cardiovascular disease (CVD) is established, less is known about the relationship between CVD risk factors and future depression, and no studies have examined MDD subtypes. Our objective was to determine whether hypertension, tobacco use, and body mass index (BMI) differentially predict atypical and typical MDD in a national sample of U.S. adults. Methods We examined prospective data from 22,915 adults with no depressive disorder history at baseline who participated in Wave 1 (2001-2002) and Wave 2 (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). CVD risk factors (Wave 1) and incident MDD subtypes (Wave 2) were determined by structured interviews. Results There were 252 atypical and 991 typical MDD cases. In fully-adjusted models, baseline hypertension (OR=0.58, 95% CI: 0.43-0.76), former tobacco use (OR=1.46, 95% CI: 1.20-1.78), and BMI (OR=1.32, 95% CI: 1.25-1.40; all p’s<0.001) predicted incident atypical MDD versus no MDD, whereas no CVD risk factor predicted incident typical MDD. Baseline hypertension (OR=0.52, 95% CI: 0.39-0.70), former tobacco use (OR=1.53, 95% CI: 1.22-1.93), and BMI (OR=1.26, 95% CI: 1.18-1.36; all p’s<0.001) also predicted incident atypical MDD versus typical MDD. Conclusions Our study is the first to report that CVD risk factors differentially predict MDD subtypes, with hypertension (protective factor), former tobacco use (risk factor), and BMI (risk factor) being stronger predictors of incident atypical versus typical MDD. Such evidence could provide insights into the etiologies of MDD subtypes and inform interventions tailored to MDD subtype

Retro American

Diesel exhaust is a suggested risk factor for ischemic heart disease (IHD), but evidence from cohorts using quantitative exposure metrics is limited. We examined the impact of respirable elemental carbon (REC), a key surrogate for diesel exhaust, and respirable dust (RD) on IHD mortality, using data from the Diesel Exhaust in Miners Study in the United States. Using data from a cohort of male workers followed from 1948–1968 until 1997, we fitted Cox proportional hazards models to estimate hazard ratios for IHD mortality for cumulative and average intensity of exposure to REC and RD. Segmented linear regression models allowed for nonmonotonicity. Hazard ratios for cumulative and average REC exposure declined relative to the lowest exposure category before increasing to 0.79 and 1.25, respectively, in the highest category. Relative to the category containing the segmented regression change points, hazard ratios for the highest category were 1.69 and 1.54 for cumulative and average REC exposure, respectively. Hazard ratios for RD exposure increased across the full exposure range to 1.33 and 2.69 for cumulative and average RD exposure, respectively. Tests for trend were statistically significant for cumulative REC exposure (above the change point) and for average RD exposure. Our findings suggest excess risk of IHD mortality in relation to increased exposure to REC and RD. © 2018 Oxford University Press. All Rights Reserved

Physicians' use of the 5As in counseling obese patients: is the quality of counseling associated with patients' motivation and intention to lose weight?

<p>Abstract</p> <p>Background</p> <p>Physicians are encouraged to counsel obese patients to lose weight, but studies measuring the quality of physicians' counseling are rare. We sought to describe the quality of physicians' obesity counseling and to determine associations between the quality of counseling and obese patients' motivation and intentions to lose weight, key predictors of behavior change.</p> <p>Methods</p> <p>We conducted post-visit surveys with obese patients to assess physician's use of 5As counseling techniques and the overall patient-centeredness of the physician.. Patients also reported on their motivation to lose weight and their intentions to eat healthier and exercise. One-way ANOVAs were used to describe mean differences in number of counseling practices across levels of self-rated intention and motivation. Logistic regression analyses were conducted to assess associations between number of 5As counseling practices used and patient intention and motivation.</p> <p>Results</p> <p>137 patients of 23 physicians were included in the analysis. While 85% of the patients were counseled about obesity, physicians used only a mean of 5.3 (SD = 4.6) of 18 possible 5As counseling practices. Patients with higher levels of motivation and intentions reported receiving more 5As counseling techniques than those with lower levels. Each additional counseling practice was associated with higher odds of being motivated to lose weight (OR 1.31, CI 1.11-1.55), intending to eat better (OR 1.23, CI 1.06-1.44), and intending to exercise regularly (OR 1.14, CI 1.00-1.31). Patient centeredness of the physician was also positively associated with intentions to eat better (OR 2.96, CI 1.03-8.47) and exercise (OR 26.07, CI 3.70-83.93).</p> <p>Conclusions</p> <p>Quality of physician counseling (as measured using the 5As counseling framework and patient-centeredness scales) was associated with motivation to lose weight and intentions to change behavior. Future studies should determine whether higher quality obesity counseling leads to improved behavioral and weight outcomes.</p