Metal Toxicity During Short‐Term Sediment Resuspension and Redeposition in a Tropical Reservoir

Billings Complex is the largest water‐storage reservoir in São Paulo, Brazil, and has been contaminated since the 1960s. Periodically, Billings sediments are subjected to currents causing resuspension and subsequent release of metals. A short‐term (4‐h) resuspension was simulated using sediment flux exposure chambers (SeFECs) to better understand the fate, bioavailability, and transport of iron (Fe), manganese (Mn), and zinc (Zn) during these events, as well as possible organism toxicity. Daphnia magna and Hyalella azteca were exposed during the 4‐h resuspension, and were monitored after exposure for survival, growth, and reproduction. Resuspension rapidly deoxygenated the overlying water, decreased the pH, and resulted in elevated dissolved Zn above the US Environmental Protection Agency’s (2002) criteria for acute toxicity (120 µg L–1). However, Zn was scavenged (after 20 h) from solution as new sorption sites formed. Dissolved Mn increased during and after resuspension, with maximum values at 20 h post exposure. An initial release of Fe occurred, likely associated with oxidation of acid‐volatile sulfides, but decreased after 1 h of resuspension. The Fe decrease is likely due to precipitation as oxyhydroxides. No acute toxicity was observed during resuspension; however, mortality of D. magna and H. azteca occurred during the postexposure period. Daphnia magna also exhibited chronic toxicity, with decreased neonate production after exposure. This sublethal effect could lead to decreased zooplankton populations over a longer period in the reservoir. Environ Toxicol Chem 2019;38:1476–1485. © 2019 SETACConceptual model of metal (Me) speciation under different sediment redox states. During bedded conditions (A) metals are mainly bounded as insoluble sulfides or associated with organic carbon (OC). When resuspended (B), sulfide species are oxidized, mobilizing metals (such as Zn) into the overlying water (OW). However, the mobilized metal is scavenged by OC and freshly‐precipitated FexOx. As particles redeposit (C), and are returned to the benthic environment, further oxidation can occur in the aerobic sediment layer releasing Fe. High dissolved Fe concentrations in OW caused acute and chronic toxicity to D. magna. Ingestion of Zn caused growth inhibition and mortality to H. azteca.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149673/1/etc4434_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149673/2/etc4434.pd

Laboratory and Field‐Based Assessment of the Effects of Sediment Capping Materials on Zinc Flux, Bioavailability, and Toxicity

A former mining site has been the subject of extensive remediation and restoration, with a significant focus on disconnecting mine spoils from groundwater and managing the quantity and quality of runoff. A remaining task is ensuring concentrations of zinc (Zn) in the stream outflow of a pit lake are reduced below water quality standards. The efficacy of multiple capping materials for decreasing Zn dissolution from sediments was conducted under natural and reasonable worst‐case conditions (pH = 5.5). Capping materials included AquaBlok™, limestone, and limestone–bone char. Field exposures were conducted in limnocorrals that isolated overlying water columns above the sediment and capping treatments. Simultaneous in situ and ex situ toxicity tests were conducted using Daphnia magna, Hyalella azteca, and Chironomus dilutus. In situ caged organisms were protected from temperature shock (warm epilimnetic waters) by deploying within a Toxicity Assessment Container System (TACS). Organisms were exposed to surficial sediments, caps, and hypolimnetic overlying waters for 4 d. Ex situ testing was conducted in core tube mesocosms containing sediments and caps at similar temperatures (15–19 °C). Results demonstrated the usefulness of TACS deployment in stratified lake systems. There were no differences in responses between treatments involving sediment capping materials in both in situ and ex situ tests. The lack of differences was likely due to dissolved Zn in surface water being below the hardness‐adjusted threshold effects levels (164 μg L–1). This field‐ and laboratory‐based weight‐of‐evidence study provided site‐specific data to support the selection of an effective remedy, with reduced uncertainty compared to laboratory and chemistry‐only approaches. Environ Toxicol Chem 2019;39:240–249. © 2019 SETACPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152878/1/etc4612.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152878/2/etc4612_am.pd

Courageous Conversations finale with Tom Friedman

Monday, September 23, 2019 1:00 - 2:30 p.m. Cowles Auditorium Humphrey School of Public Affairs 301 19th Avenue South Minneapolis, MN 55455 All around Minnesota, communities are redefining what it means to have a healthy economy and an engaged workforce. Tom Friedman has been traveling to towns in Minnesota and around the country to wonder why some are prospering, while others are losing population and jobs. Tom Friedman’s presentation is the culmination of an 18-month event series, traveling around the state to explore how older workers could be part of the solution to our state’s workforce shortages as Baby Boomers retire. Join us for the series conclusion on September 23rd to hear best practices and ideas for reviving towns in Minnesota. Featuring: ● New York Times columnist Tom Friedman ● Courageous Conversations series moderator Gary Eichten ● Panelists from Southwest Minnesota, the Iron Range, and the Twin CitiesCenter for the Study of Politics and Governance McKnight Foundatio

Triggers of Lapse and Relapse of Diet and Exercise in Behavioral Weight Loss

OBJECTIVE: This study aimed to (1) develop instruments to evaluate situations that lead to lapse and relapse in diet and exercise and (2) prospectively investigate when and which psychosocial situations predict failure to lose weight in a clinical trial of intentional weight loss. METHODS: Participants were 469 individuals with overweight or obesity participating in a behavioral weight loss program (age: mean = 53.6 years, SD = 11.4; BMI: mean = 35.7 kg/m RESULTS: The Cronbach alphas for the Diet Lapse and Relapse Triggers Scale and the Exercise Lapse and Relapse Triggers Scale were 0.93 and 0.91, respectively. Subscale alphas ranged from 0.60 to 0.96. Lapse and relapse were assessed at 3 and 9 months for associations with weight loss at 12 months. At 9 months, diet triggers were negative emotional states (beta = 0.11, P = 0.02) and urges (beta = 0.14, P = 0.01). Predicted social situations showed the opposite (beta = -0.09, P = 0.02). Exercise subscales were all nonsignificant. CONCLUSIONS: Findings suggest the ongoing importance of addressing negative emotional states and the contributing influence of urges. The novel finding that participants whose difficulties arise in social situations may do better over time requires further study

Spatial immune profiling of glioblastoma identifies an inflammatory, perivascular phenotype associated with longer survival

ISSN:0001-6322ISSN:1432-053

Inhibition and facilitation in schizotypy

Participants scoring high and low on a schizotypy scale (n = 18 in each group) switched between naming words and naming colors in a Stroop task in congruent, neutral, and incongruent conditions. The findings were that, while being slower and less accurate overall than low schizotypes, the high schizotypy group did not display disproportionately greater Stroop inhibition or facilitation, suggesting intact selective attention. However, the high schizotypy group suffered disproportionately larger switching costs. The results provide evidence for similarities between schizotypy and schizophrenia, specifically that the problem in schizotypy is to do with switching rather than selecting attention, because of a difficulty either in selecting task-relevant information or in inhibiting inappropriate response alternatives. <br /