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Engineered cerium oxide nanoparticles (CeO 2 NPs) are widely used in biomedical and engineering manufacturing industries. Previous research has shown the ability of CeO 2 NPs to act as a redox catalyst, suggesting potential to both induce and alleviate oxidative stress in organisms. In this study, Caenorhabditis elegans and zebrafish ( Danio rerio ) were dosed with commercially available CeO 2 NPs. Non-nano cerium oxide powder (CeO 2 ) was used as a positive control for cerium toxicity. CeO 2 NPs suspended in standard United States Environmental Protection Agency reconstituted moderately hard water, used to culture the C. elegans , quickly formed large polydisperse aggregates. Dosing solutions were renewed daily for 3 days. Exposure of wild-type nematodes resulted in dose-dependent growth inhibition detected for all 3 days ( p  < 0.0001). Non-nano CeO 2 also caused significant growth inhibition ( p  < 0.0001), but the scale of inhibition was less at equivalent mass exposures compared with CeO 2 NP exposure. Some metal and oxidative stress-sensitive mutant nematode strains showed mildly altered growth relative to the wild-type when dosed with 5 mg/L CeO 2 NPs on days 2 and 3, thus providing weak evidence for a role for oxidative stress or metal sensitivity in CeO 2 NP toxicity. Zebrafish microinjected with CeO 2 NPs or CeO 2 did not exhibit increased gross developmental defects compared with controls. Hyperspectral imaging showed that CeO 2 NPs were ingested but not detectable inside the cells of C. elegans . Growth inhibition observed in C. elegans may be explained at least in part by a non-specific inhibition of feeding caused by CeO 2 NPs aggregating around bacterial food and/or inside the gut tract.

Selenium (Se) is an essential micronutrient that can be found at toxic concentrations in surface waters contaminated by runoff from agriculture and coal mining. Zebrafish (Danio rerio) embryos were exposed to aqueous Se in the form of selenate, selenite, and L-selenomethionine (SeMet) in an attempt to determine if oxidative stress plays a role in selenium embryo toxicity. Selenate and selenite exposure did not induce embryo deformities (lordosis and craniofacial malformation). L-selenomethionine, however, induced significantly higher deformity rates at 100 µg/L compared with controls. SeMet exposure induced a dose-dependent increase in the catalytic subunit of glutamate-cysteine ligase (gclc) and reached an 11.7-fold increase at 100 µg/L. SeMet exposure also reduced concentrations of TGSH, RGSH, and the TGSH:GSSG ratio. Pretreatment with 100 µM N-acetylcysteine significantly reduced deformities in the zebrafish embryos secondarily treated with 400 µg/L SeMet from approximately 50–10 % as well as rescued all three of the significant glutathione level differences seen with SeMet alone. Selenite exposure induced a 6.6-fold increase in expression of the glutathione-S-transferase pi class 2 (gstp2) gene, which is involved in xenobiotic transformation and possibly oxidative stress. These results suggest that aqueous exposure to SeMet can induce significant embryonic teratogenesis in zebrafish that are at least partially attributed to oxidative stress.

A major contaminant of concern for mountaintop removal/valley fill (MTR/VF) coal mining is selenium (Se), an essential micronutrient that can be toxic to fish. Creek chubs (Semotilus atromaculatus), green sunfish (Lepomis cyanellus), and composite insect samples were collected in March-July, 2011–2013 at two sites within the Mud River, West Virginia. One site (MR7) receives MTR/VF coal mining effluent, while the reference site (LFMR) does not. MR7 water had significantly higher concentrations of soluble Se (p < 0.01) and conductivity (p < 0.005) compared to LFMR. MR7 whole insects contained significantly higher concentrations of Se compared to LFMR insects (p < 0.001). MR7 creek chubs had significantly higher Se in fillets, liver, and ovary tissues compared to LFMR samples (p < 0.0001, p < 0.0001, and p < 0.02, respectively). MR7 green sunfish fillets contained significantly higher Se (p < 0.0001). Histological examination showed LFMR creek chub gills contained a typical amount of parasitic infestations; however MR7 gills contained minimal to no visible parasites. X-ray absorption spectroscopic analyses revealed that MR7 whole insects and creek chub tissues primarily contained organic Se and selenite. These two species of Mud River fish were shown to specifically accumulate Se differently in tissues compartments. Tissue-specific concentrations of Se may be useful in determining potential reproductive consequences of Se exposure in wild fish populations.

Our objectives were to determine whether peripheral quantitative computed tomography (pQCT)-derived lower leg muscle density and area, and basic functional mobility differ between communitydwelling older women who do and do not report recent falls. Matched case-control comparison. Academic biomedical imaging laboratory. 147 Women, 60 years or older (mean age 74.3 y, SD 7.7) recruited from a longitudinal, population-based cohort representing community-dwelling residents in the area of Saskatoon, Canada. A cross-sectional pQCT scan of the non-dominant lower leg was acquired to determine muscle density and area. Basic functional mobility (Timed Up and Go Test [TUG]) and SF36 health status were also measured. Fallers (one or more falls) and non-fallers (no falls) were grouped according to a 12-month retrospective survey and matched on measured covariates. The muscle density of fallers (n = 35) was a median of 2.1 mg/cm3 lower (P = 0.019, 95% C.I. −3.9 to −0.1) than non-fallers (n = 78) after matching and adjusting for age, body mass index, and SF36 general health scores. Muscle area and TUG did not differ between fallers and non-fallers. Muscle density may serve as a physiological marker in the assessment of lower leg muscular health and fall risk in community-dwelling elderly women. These results are limited to our study population who were mostly Caucasian. Prospective studies are required for verification.

Summary Muscle density is a risk factor for fractures in older adults; however, its association with falls is not well described. After adjusting for biologically relevant confounding factors, a unit decrease in muscle density was associated with a 17 % increase in odds of reporting a fall, independent of functional mobility. Introduction Falls are the leading cause of injury, disability, and fractures in older adults. Low muscle density (i.e., caused by muscle adiposity) and functional mobility have been identified as risk factors for incident disability and fractures in older adults; however, it is not known if these are also independently associated with falls. The purpose of this study was to explore the associations of muscle density and functional mobility with fall status. Methods Cross-sectional observational study of 183 men and women aged 60–98 years. Descriptive data, including a 12-month fall recall, Timed Up and Go (TUG) test performance, lower leg muscle area, and density. Odds ratio (OR) of being a faller were calculated, adjusted for age, sex, body mass index, general health status, diabetes, and comorbidities. Results Every mg/cm 3 increase in muscle density (mean 70.2, SD 2.6 mg/cm 3 ) independently reduced the odds of being a faller by 19 % (OR 0.81 [95 % CI 0.67 to 0.97]), and every 1 s longer TUG test time (mean 9.8, SD 2.6 s) independently increased the odds by 17 % (OR 1.17 [95 % CI 1.01 to 1.37]). When both muscle density and TUG test time were included in the same model, only age (OR 0.93 [95 % CI 0.87 to 0.99]) and muscle density (OR 0.83 [95 % CI 0.69 to 0.99]) were independently associated with fall status. Conclusions Muscle density was associated with fall status, independent of functional mobility. Muscle density may compliment functional mobility tests as a biometric outcome for assessing fall risk in well-functioning older adults.

Background. Individuals with acute infections experience a range of symptoms including fatigue, malaise, muscle aches, and difficulties with concentration and memory that are usually self-limited. This cluster of symptoms is otherwise, similar to those that characterize chronic fatigue syndrome (CFS). The goal of the present study was to evaluate the cognitive and psychological functioning of CFS patients and normal controls (NCs) when they both were experiencing acute influenza-like symptoms. To induce influenza-like symptoms, we administered interleukin-6 (IL-6), a cytokine that temporarily activates the acute phase immunological and endocrine responses. Methods. Nineteen patients who met the 1994 International CFS Study Group Criteria and ten normal controls (NCs) completed routine clinical evaluations, neuropsychological tests of short-term memory, selective attention, and executive control, and self-ratings of somatic symptoms and psychological mood before, shortly following, and 1 day after IL-6 administration. Results. CFS patients consistently reported more somatic symptoms, even when both groups perceived that they were ill. Both groups somatic symptoms increased during the IL-6 challenge, but the CFS patients symptoms increased more rapidly than controls. In general, the CFS patients performed similarly to NCs on the cognitive measures before, during, and after the IL-6. In contrast to predictions, IL-6 provocation did not impair the cognitive performance of either CFS patients or NCs. Conclusions. The IL-6 provocation exacerbated the patients self-reported symptoms but did not reveal notable cognitive impairments between patients and controls during cytokine-induced acute influenza-like symptoms.

Microbial nutrient limitation was investigated in a 53-year-old field experiment in the Central-West of Burkina Faso under sorghum–cowpea rotation, comparing three fertilization practices: mineral fertilizer (MIN), mineral fertilizer and farmyard manure (MINFYM), and a non-fertilized control (CON). We assessed microbial N and P limitation after removal of C limitation by (i) determining microbial N and P, (ii) assessing respiration kinetics in incubated soil samples amended with easily available C (glucose) alone or in combination with N and/or P, or not amended, and (iii) evaluating changes in microbial biomass and community composition at the peak of microbial respiration by microbial P and phospholipid fatty acid (PLFA) analyses. Microbial N and P were very low in all fertilization practices, but greater in MINFYM than in CON. Easily available C was the first factor limiting microorganisms in all fertilization practices. After removal of C limitation, most indicators suggested N and P co-limitation in CON. In contrast, respiration kinetics in MINFYM and MIN were only N-limited, while biomass formation in MINFYM was also P-limited. PLFA analyses indicated preferential fungal growth on the added C, and P limitation of changes in microbial community composition in MIN. Long-term application of fertilizers mostly alleviated secondary microbial nutrient limitation by P but not by N, and C always remained the primary limiting factor for microbial growth.

Property theorists hypothesize a trend of evolution toward efficiency and conventionally hold formal privatization out as the logical endpoint of this trend. Oystering, in particular, has often been cited as a context in which privatization is highly efficient. Nonetheless, in the nineteenth century, public ownership of Connecticut's valuable oyster grounds persisted throughout decades of economic and technological change. The history of Connecticut's hybrid regime in oyster grounds, which variably applied enclosure and common ownership to otherwise similarly situated areas, shows that such regimes can emerge and thrive for both economic and political reasons.

Summary Distal radius (wrist) fracture (DRF) in women over age 50 years is an early sign of bone fragility. Women with a recent DRF compared to women without DRF demonstrated lower bone strength, muscle density, and strength, but no difference in dual-energy x-ray absorptiometry (DXA) measures, suggesting DXA alone may not be a sufficient predictor for DRF risk. Introduction The objective of this study was to investigate differences in bone and muscle properties between women with and without a recent DRF. Methods One hundred sixty-six postmenopausal women (50–78 years) were recruited. Participants were excluded if they had taken bone-altering medications in the past 6 months or had medical conditions that severely affected daily living or the upper extremity. Seventy-seven age-matched women with a fracture in the past 6–24 months (Fx, n  = 32) and without fracture (NFx, n  = 45) were measured for bone and muscle properties using the nondominant (NFx) or non-fractured limb (Fx). Peripheral quantitative computed tomography (pQCT) was used to estimate bone strength in compression (BSI c ) at the distal radius and tibia, bone strength in torsion (SSIp) at the shaft sites, muscle density, and area at the forearm and lower leg. Areal bone mineral density at the ultradistal forearm, spine, and femoral neck was measured by DXA. Grip strength and the 30-s chair stand test were used as estimates of upper and lower extremity muscle strength. Limb-specific between-group differences were compared using multivariate analysis of variance (MANOVA). Results There was a significant group difference ( p  < 0.05) for the forearm and lower leg, with the Fx group demonstrating 16 and 19 % lower BSI c , 3 and 6 % lower muscle density, and 20 and 21 % lower muscle strength at the upper and lower extremities, respectively. There were no differences between groups for DXA measures. Conclusions Women with recent DRF had lower pQCT-derived estimated bone strength at the distal radius and tibia and lower muscle density and strength at both extremities.