Recycled concrete aggregates are an economic form of urban riparian erosion management with limited impacts on freshwater chemistry and microbial diversity.

Urban streams are at high risk of riparian erosion which impacts adjacent infrastructure stability. Methods to prevent stream erosion have been proposed including using recycled concrete (RC) materials to help stabilize the streambed; however, little is known about the environmental and biological impacts of using RC in urban streams. RC, new concrete (NC), and river rock controls were evaluated for their impact on water chemistry, water quality, and microbial community composition over 6.5 months in controlled laboratory mesocosms. Concentrations of 19 metals, nutrients, and pH of mesocosms containing RC were not significantly different from the river rock mesocosm throughout the experiment; however, NC mesocosms contained significantly higher (p < 0.05) concentrations of Co, As, Al, and V in mesocosm water samples compared to both RC and the river rock control. Microbial community diversity was not significantly impacted by mesocosm treatment. Microbial sequences mapping to taxa including Rhodoferax, Acidovorax, Nitrosomonas, and Novosphingobium were significantly more abundant (p < 0.01) in RC and NC mesocosm samples; however, the overall microbial community structure was similar across treatment types. Results from this study suggest that RC does not significantly alter the stream environment including microbial community diversity and is a viable option for use in stream restoration projects.

Antimicrobial Resistance Traits of Escherichia coli Isolated from Dairy Manure and Freshwater Ecosystems Are Similar to One Another but Differ from Associated Clinical Isolates.

Antimicrobial resistance (AMR) is a prevalent global health problem across human and veterinary medicine. The One Health approach to AMR is necessary to mitigate transmission between sources of resistance and decrease the spread of resistant bacteria among humans, animals, and the environment. Our primary goal was to identify associations in resistance traits between Escherichia coli isolated from clinical (n = 103), dairy manure (n = 65), and freshwater ecosystem (n = 64) environments within the same geographic location and timeframe. Clinical E. coli isolates showed the most phenotypic resistance (47.5%), followed by environmental isolates (15.6%) and manure isolates (7.7%), with the most common resistances to ampicillin, ampicillin-sulbactam, and cefotaxime antibiotics. An isolate subset was screened for extended spectrum beta-lactamase (ESBL) production resulting in the identification of 35 ESBL producers. The most common ESBL gene identified was blaTEM-1. Additionally, we found nine different plasmid replicon types including IncFIA-FIB, which were frequently associated with ESBL producer isolates. Molecular phylotyping revealed a significant portion of clinical E. coli were associated with phylotype B2, whereas manure and environmental isolates were more diverse. Manure and environmental isolates were significantly different from clinical isolates based on analyzed traits, suggesting more transmission occurs between these two sources in the sampled environment.

Identification and characterization of the unique guanine nucleotide exchange factor, SmgGDS, in vascular smooth muscle cells.

The guanine nucleotide exchange factor (GEF), SmgGDS, promotes nucleotide exchange by several GTPases in both the Ras and Rho families, especially by RhoA. Because RhoA plays an important role in regulating the contraction of vascular smooth muscle cells (VSMC), we examined the expression and function of SmgGDS in VSMC. SmgGDS is expressed in primary rat aortic smooth muscle (ASM) cells, primary bovine coronary artery smooth muscle (BCASM) cells, and the immortalized A7r5 line of rat ASM cells. Down regulation of SmgGDS expression by siRNA transfection resulted in a decrease of RhoA-GTP levels, enhanced cell spreading, and loss of the characteristic elongated morphology of VSMC. A similar morphology was also observed following treatment with the Rho-kinase inhibitor, Y27632. In contrast, cells with reduced RhoA expression exhibit an elongated shape. Subsequent immunofluorescent staining revealed a disruption of the myosin filament organization in the cells with reduced SmgGDS expression. Further studies analyzed the effect of SmgGDS siRNA transfection on the contraction of A7r5 cells and BCASM cells, which is also a Rho-regulated pathway. Transfection of SmgGDS siRNA or RhoA siRNA resulted in an impaired ability of the A7r5 and BCASM cells to undergo contraction in a collagen gel matrix. However, phosphorylation of the myosin-binding subunit of myosin phosphatase (MYPT1) or the light chain of myosin II (MLC) was not altered by downregulating expression of either SmgGDS or RhoA GTPase. Taken together these results identify SmgGDS as a novel regulator of myosin organization and contraction in VSMC.

Expression and function of fatty acid amide hydrolase in prostate cancer.

The hydrolysis of endocannabinoids has profound effects on the function of the endocannabinoid signaling system in the regulation of prostate carcinoma cells. Prostate carcinoma cells exhibit a wide range of hydrolysis activity for 2-arachidonoylglycerol (2-AG), the major endocannabinoid. However, enzyme(s) responsible for 2-AG hydrolysis and their functions in prostate cancer have not been characterized. In this study, we demonstrated that fatty acid amide hydrolase (FAAH) was differentially expressed in normal and prostate carcinoma cells. In PC-3 cells, overexpression of FAAH resulted in increased FAAH protein, 2-AG hydrolysis, cell invasion and cell migration. Conversely, small-interfering RNA (siRNA) knockdown of FAAH in LNCaP cells decreased FAAH protein, 2-AG hydrolysis and cell invasion. Furthermore, CAY10401, a FAAH inhibitor, decreased cell invasion and it enhanced the reduction of invasion in FAAH siRNA-transfected LNCaP cells. Immunohistochemistry staining of commercial tissue microarrays (TMAs) demonstrated FAAH staining in 109 of 157 cores of prostate adenocarcinomas but weak staining in 1 of 8 cores of normal prostate tissues. These results suggest that FAAH regulates 2-AG hydrolysis and invasion of prostate carcinoma cells and is potentially involved in prostate tumorigenesis.

A problem with double-blind photospread procedures: photospread administrators use one eyewitness's confidence to influence the identification of another eyewitness.

In Experiment 1, photospread administrators (PAs, N = 50) showed a target-absent photospread to a confederate eyewitness (CW), who was randomly assigned to identify one photo with either high or low confidence. PAs subsequently administered the same target-absent photospread to participant eyewitnesses (PWs, N = 50), all of whom had viewed a live staged crime 1 week earlier. CWs were rated by the PAs as significantly more confident in the high-confidence condition versus low-confidence condition. More importantly, the confidence of the CW affected the identification decision of the PW. In the low-confidence condition, the photo identified by the CW was identified by the PW significantly more than the other photos; there was no significant difference in photo choice in the high-confidence condition. In spite of the obvious influence exerted in the low-confidence condition, observers were not able to detect bias in the photospread procedures. A second experiment was conducted to test a post-hoc explanation for the results of Experiment 1: PAs exerted influence in the low-confidence condition because they perceived the task as more difficult for the eyewitness than in the high-confidence condition. Independent observers (N = 84) rated the difficulty of the confederate's task as higher in the low-confidence condition compared with the high-confidence condition, suggesting that expectations of task difficulty might be driving the effect observed in Experiment 1. Results support recommendations for double-blind photospreads and emphasize that the same investigator should not administer photo lineups to multiple eyewitnesses in an investigation.