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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.dsr.2010.05.007 Byline: S. Paul Hansard, Andrew W. Vermilyea, Bettina M. Voelker Keywords: Superoxide; Reactive oxygen species; Metal speciation; Chemiluminescence Abstract: Numerous laboratory studies have shown that superoxide radical (O.sub.2.sup.-) can have a profound influence on the redox speciation of dissolved metals, especially copper, manganese, and iron. We made direct measurements of O.sub.2.sup.- concentrations and decay kinetics in seawater samples collected from the Gulf of Alaska, using the recently developed method of methyl Cypridina luciferin analog (MCLA) chemiluminescence. Concentrations ranged from Our study was also the first to examine the reproducibility of measurements of in situ O.sub.2.sup.- concentrations and decay coefficients. Subsurface samples collected using GO-FLO bottles exhibited a systematic increase in concentration and decay rate coefficient with time, a possible artifact that should be considered in future studies. In contrast, measurements conducted using 'fish' samples under low or no light conditions were found to be reliably reproducible, and demonstrated substantial rates of biological O.sub.2.sup.- production. Author Affiliation: Department of Chemistry and Geochemistry, Coolbaugh Hall, Colorado School of Mines, Golden, CO 80401-1887, United States Article History: Received 3 February 2010; Revised 18 May 2010; Accepted 26 May 2010

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jue.2006.05.005 Byline: McKinley Blackburn (a), Todd Vermilyea (b) Keywords: Mortgage lending; Redlining; Information externalities Abstract: Theories of rational redlining suggest a low volume of sales should lead to greater uncertainty in house price appraisals, making the mortgage loan less attractive to lenders. This paper represents the first test of this 'information externality' theory using a well-specified model of lending. In our preferred model, information externalities are relevant but the marginal effect diminishes quickly, with only about 10 percent of applications materially disadvantaged by a low volume of sales. Our results also support the presence of bank-level economies of scale to reviewing applications in a given area, with increased bank-level applications associated with higher acceptance rates. Author Affiliation: (a) Department of Economics, University of South Carolina, Columbia, SC 29208, USA (b) Federal Reserve Bank of Philadelphia, Ten Independence Mall, Philadelphia, PA 19106, USA Article History: Received 22 August 2005; Revised 23 May 2006 Article Note: (footnote) [star] The views expressed in this paper do not necessarily represent those of the Federal Reserve Bank of Philadelphia or the Federal Reserve System, the Office of the Comptroller of the Currency or the Department of the Treasury.

• Disparate mercury yields from two glacierized watersheds point to bedrock differences. • Total Hg yield from the Mendenhall glacier is the highest in the literature. • Snow and glacial outflow data suggest subglacial Hg methylation. Mercury (Hg) export from glacierized watersheds is poorly understood, with very few studies worldwide on Hg concentration and speciation in glacier snow, ice, and meltwater, and on Hg fluxes to downstream freshwater and coastal ecosystems. In addition to bedrock-derived geogenic Hg, glaciers may be releasing legacy accumulations of natural and anthropogenically-sourced Hg trapped in glacier ice melt each summer season. Our prior work showed that a glacierized stream in southeast Alaska had the highest reported flux of inorganic mercury of all known non-mining impacted streams, highlighting the strong ability of glaciers to mobilize the trace metal. Here we present data on Hg concentrations, speciation, partitioning, and fluxes from two more glacierized watersheds (Herbert and Mendenhall Rivers), and we compare them to an adjacent non-glacierized, forested-wetland stream (Peterson Creek). Results show that the glacierized streams carried Hg largely in the particulate form, whereas the forested-wetland stream carried it largely in the filtered fraction, at 20 fold higher concentration than in the glacierized streams, and with a higher percent of Hg in its methylated form. Yet, considering the higher water and sediment yields (as mass per watershed area per year) of the glacierized streams during the summer melt season, the yield of total Hg (unfiltered) from the Mendenhall glacier was approximately 80 times higher than from the Herbert glacier and 50 times higher than in Peterson Creek and presents the highest watershed yields of total Hg and methyl-Hg reported in the literature to date. Incongruous yields out of the two glacierized streams can likely be explained by differences in underlying bedrock geology. Based on the sediments entrained in Mendenhall meltwater, the late Paleozoic to Paleocene metasedimentary and volcanic rocks being eroded in the terminal 3 km of the Mendenhall are elevated above mean crustal concentrations by at least 4–17 fold. Differences in speciation between the glacierized and non-glacierized streams are likely accounted for by glacial and watershed geochemical conditions that variably promote Hg methylation. [ABSTRACT FROM AUTHOR]

In this study, a stream from a glacially dominated watershed and one from a wetland, temperate forest dominated watershed in southeast Alaska were continuously monitored for turbidity and fluorescence from dissolved organic matter (FDOM) while grab samples for unfiltered (UTHg), particulate (PTHg), and filtered mercury (FTHg) where taken over three 4-day periods (May snowmelt, July glacial melt, and September rainy season) during 2010. Strong correlations were found between FDOM and UTHg concentrations in the wetland, temperate forest watershed (r 2 = 0.81), while turbidity and UTHg were highly correlated in the glacially dominated watershed (r 2 = 0.82). Both of these parameters (FDOM and turbidity) showed stronger correlations than concentration-discharge relationships for UTHg (r 2 = 0.55 for glacial stream, r 2 = 0.38 for wetland/forest stream), thus allowing for a more precise determination of temporal variability in UTHg concentrations and fluxes. The association of mercury with particles and dissolved organic matter (DOM) appears to depend on the watershed characteristics, such as physical weathering and biogeochemical processes regulating mercury transport. Thus employing watershed-specific proxies for UTHg (such as FDOM and turbidity) can be effective for quantifying mercury export from watersheds with variable landcover. The UTHg concentration in the forest/wetland stream was consistently higher than in the glacial stream, in which most of the mercury was associated with particles; however, due to the high specific discharge from the glacial stream during the melt season, the watershed area normalized flux of mercury from the glacial stream was 3–6 times greater than the wetland/forest stream for the three sampling campaigns. The annual specific flux for the glacial watershed was 19.9 g UTHg km − 2 y − 1 , which is higher than any non-mining impacted stream measured to date. This finding indicates that glacial watersheds of southeast Alaska may be important conduits of total mercury to the Gulf of Alaska. [ABSTRACT FROM AUTHOR]

At the moment of union in fertilization, sperm and oocyte are transcriptionally silent. The ensuing onset of embryonic transcription (embryonic genome activation [EGA]) is critical for development, yet its timing and profile remain elusive in any vertebrate species. We here dissect transcription during EGA by high-resolution single-cell RNA sequencing of precisely synchronized mouse one-cell embryos. This reveals a program of embryonic gene expression (immediate EGA [iEGA]) initiating within 4 h of fertilization. Expression during iEGA produces canonically spliced transcripts, occurs substantially from the maternal genome, and is mostly downregulated at the two-cell stage. Transcribed genes predict regulation by transcription factors (TFs) associated with cancer, including c-Myc. Blocking c-Myc or other predicted regulatory TF activities disrupts iEGA and induces acute developmental arrest. These findings illuminate intracellular mechanisms that regulate the onset of mammalian development and hold promise for the study of cancer. [Display omitted] • A gene expression program, iEGA, initiates within 4 h of mouse fertilization • Upregulated genes are normatively spliced, protein coded, and soon downregulated • iEGA genes predict cancer-associated pathways and transcription regulators • Inhibiting predicted transcription regulators acutely disrupts iEGA and development How and when embryonic transcription begins following fertilization remains elusive. Asami et al. generate a high-resolution time course to reveal a transcription program initiating within 4 h of fertilization in mouse one-cell embryos. The program predicts embryonic and cancer-associated pathway expression, and inhibiting inferred regulators acutely blocks transcription and development. [ABSTRACT FROM AUTHOR]

Accumulation of α-synuclein (α-syn) leading to the formation of insoluble intracellular aggregates named Lewy bodies is proposed to have a significant role in Parkinson's disease (PD) pathology. Nonhuman primate (NHP) models of PD have proven essential for understanding the neurobiological basis of the disease and for the preclinical evaluation of first-in-class and invasive therapies. In addition to neurotoxin, aging and intracerebral gene transfer models, a new generation of models using inoculations of α-syn formulations, as well as transgenic methods is emerging. Understanding of their advantages and limitations will be essential when choosing a platform to evaluate α-syn-related pathology and interpreting the test results of new treatments targeting α-syn aggregation. In this review we aim to provide insight on this issue by critically analyzing the differences in endogenous α-syn, as well as α-syn pathology in PD and PD NHP models. [ABSTRACT FROM AUTHOR]

Computer-automated time-lapse analysis has been shown to improve embryo selection by providing quantitative and objective information to supplement traditional morphology. In this multi-centre study, the relationship between such computer-derived outputs (High, Medium, Low scores), embryo implantation and clinical pregnancy were examined. Data were collected from six clinics, including 205 patients whose embryos were imaged by the Eeva™ System. The Eeva scores were blinded and not considered during embryo selection. Embryos with High and Medium scores had significantly higher implantation rates than those with Low scores (37% and 35% versus 15%; P < 0.0001; P = 0.0004). Similar trends in implantation rates were observed in different IVF centres each using their own protocols. Further analysis revealed that patients with at least one High embryo transferred had significantly higher clinical pregnancy rates than those with only Low embryos transferred (51% versus 34%; P = 0.02), although patients' clinical characteristics across groups were comparable. These data, together with previous research and clinical studies, confirm that computer-automated Eeva scores provide valuable information, which may improve the clinical outcome of IVF procedures and ultimately facilitate the trend of single embryo selection. [ABSTRACT FROM AUTHOR]

Abstract: Numerous laboratory studies have shown that superoxide radical () can have a profound influence on the redox speciation of dissolved metals, especially copper, manganese, and iron. We made direct measurements of concentrations and decay kinetics in seawater samples collected from the Gulf of Alaska, using the recently developed method of methyl Cypridina luciferin analog (MCLA) chemiluminescence. Concentrations ranged from <0.02 to ∼0.6nmolL−1, with higher concentrations typically observed in the upper 1–10m of the water column. Pseudo-first-order decay rate coefficients ranged 0.002–0.02s−1, and confirm that even in the open ocean, uncatalyzed dismutation is not the major fate of . Calculated production rates varied from <1 to ∼20nmolL−1 h−1 and appear to be primarily of biological origin. These results represent the first direct measurements of concentrations in a non-tropical region, and are broadly similar to recently published findings for the eastern equatorial Pacific, suggesting that biological production of may be a common feature of the ocean’s surface waters. Our study was also the first to examine the reproducibility of measurements of in situ concentrations and decay coefficients. Subsurface samples collected using GO-FLO bottles exhibited a systematic increase in concentration and decay rate coefficient with time, a possible artifact that should be considered in future studies. In contrast, measurements conducted using “fish” samples under low or no light conditions were found to be reliably reproducible, and demonstrated substantial rates of biological production. [ABSTRACT FROM AUTHOR]

STATEMENT OF PROBLEM: The rationale for using high noble alloys is based largely upon their alleged ability to resist corrosion. However, combining previously cast metal with new alloy might have a detrimental effect on the corrosion behavior of a high noble alloy. PURPOSE: The purpose of this study was to characterize the elemental composition of an as-received and recast high noble alloy and to examine the in vitro corrosion behavior in 2 media, using a potentiodynamic polarization technique. MATERIAL AND METHODS: Disk-shaped specimens, 6 mm in diameter and 3 mm thick, were prepared from a high noble alloy (Ney-Oro-B2) under 3 casting protocols, according to the proportion of as-received and recast gold alloy (n=26); the groups included an as-received (100% as-received metal) group, 50% to 50% group (50 wt% new metal, 50 wt% once-recast metal), and recast group (100% once-recast metal). The surface structures of 20 specimens from each group were examined under scanning electron microscopy (SEM), the elemental compositions were determined using x-ray energy-dispersive spectroscopy at 3 sites on the specimen, and the data were averaged. Further, the potentiodynamic cyclic polarization between -1000 and +1000 mV (SCE, or saturated calomel electrode) was performed for 6 specimens from each casting protocol in 0.09% NaCl solution (n=3) and Fusayama artificial saliva (n=3) at 37 degrees C. Zero-current potential and corrosion current density were determined. The data were analyzed with 1-way and 2-way analysis of variance and the Ryan-Einot-Gabriel-Welsch multiple-range t test (alpha=.05). RESULTS: Elemental composition was significantly different among the casting groups (P<.001). The mean weight percentage values were 72.7% to 75.7% Au, 4.5 to 7.0% Pd, 10.7% to 11.1% Ag, 7.8% to 8.4% Cu, and 1.0% to 1.4% Zn. The mean values for zero-current potential (ZCP) and corrosion current density (I(CORR)) for all the casting protocols were not significant (P=.67 and P=.51, respectively). Moreover, the mean values were not significant for corrosion current density with the electrolyte effect (P=.45). Only zero-current potential had a significant electrolyte effect (P<.001). Furthermore, the interaction between casting protocols and electrolyte were not significant among all corrosion parameters. CONCLUSIONS: High noble alloy in all casting protocols evaluated retained passivity under electrochemical conditions similar to the oral environment. (J Prosthet Dent 2008;100:34-40). [ABSTRACT FROM AUTHOR]

Can better methods be developed to evaluate the performance and characteristics of an artificial intelligence model for evaluating the likelihood of clinical pregnancy based on analysis of day-5 blastocyst-stage embryos, such that performance evaluation more closely reflects clinical use in IVF procedures, and correlations with known features of embryo quality are identified? De-identified images were provided retrospectively or collected prospectively by IVF clinics using the artificial intelligence model in clinical practice. A total of 9359 images were provided by 18 IVF clinics across six countries, from 4709 women who underwent IVF between 2011 and 2021. Main outcome measures included clinical pregnancy outcome (fetal heartbeat at first ultrasound scan), embryo morphology score, and/or pre-implantation genetic testing for aneuploidy (PGT-A) results. A positive linear correlation of artificial intelligence scores with pregnancy outcomes was found, and up to a 12.2% reduction in time to pregnancy (TTP) was observed when comparing the artificial intelligence model with standard morphological grading methods using a novel simulated cohort ranking method. Artificial intelligence scores were significantly correlated with known morphological features of embryo quality based on the Gardner score, and with previously unknown morphological features associated with embryo ploidy status, including chromosomal abnormalities indicative of severity when considering embryos for transfer during IVF. Improved methods for evaluating artificial intelligence for embryo selection were developed, and advantages of the artificial intelligence model over current grading approaches were highlighted, strongly supporting the use of the artificial intelligence model in a clinical setting. [ABSTRACT FROM AUTHOR]

An abstract of the article "Ploidy variation in trophectoderm biopsies from day 5, 6, and 7 blastocysts," by J. Nguyen and colleagues is presented.

Objective: To perform a series of analyses characterizing an artificial intelligence (AI) model for ranking blastocyst-stage embryos. The primary objective was to evaluate the benefit of the model for predicting clinical pregnancy, whereas the secondary objective was to identify limitations that may impact clinical use.Design: Retrospective study.Setting: Consortium of 11 assisted reproductive technology centers in the United States.Patient(s): Static images of 5,923 transferred blastocysts and 2,614 nontransferred aneuploid blastocysts.Intervention(s): None.Main Outcome Measure(s): Prediction of clinical pregnancy (fetal heartbeat).Result(s): The area under the curve of the AI model ranged from 0.6 to 0.7 and outperformed manual morphology grading overall and on a per-site basis. A bootstrapped study predicted improved pregnancy rates between +5% and +12% per site using AI compared with manual grading using an inverted microscope. One site that used a low-magnification stereo zoom microscope did not show predicted improvement with the AI. Visualization techniques and attribution algorithms revealed that the features learned by the AI model largely overlap with the features of manual grading systems. Two sources of bias relating to the type of microscope and presence of embryo holding micropipettes were identified and mitigated. The analysis of AI scores in relation to pregnancy rates showed that score differences of ≥0.1 (10%) correspond with improved pregnancy rates, whereas score differences of <0.1 may not be clinically meaningful.Conclusion(s): This study demonstrates the potential of AI for ranking blastocyst stage embryos and highlights potential limitations related to image quality, bias, and granularity of scores. [ABSTRACT FROM AUTHOR]