Search

Groundwater supplies 50% of drinking water worldwide and 30% in the United States. Geogenic and anthropogenic contaminants can, however, compromise water quality, thus limiting groundwater availability. Reduction/oxidation (redox) processes and redox conditions affect groundwater quality by influencing the mobility and transport of common geogenic and anthropogenic contaminants. In the glacial aquifer system, northern United States (GLAC, 1.87 million km2), groundwater with high arsenic or manganese concentration is associated with reducing conditions and high nitrate with oxidizing conditions. This study uses machine learning to identify the relative influence of drivers of redox conditions (e.g., residence time vs. reactivity) across the glacial landscape. We developed three‐dimensional boosted regression tree models to predict redox conditions using the likelihood of low dissolved oxygen or high iron as indicators of anoxic conditions. Results indicate that variation in redox condition is controlled primarily by residence time (e.g., groundwater age and relative depth) and to a lesser extent by geochemical reactivity (e.g., subsurface contact time, soil carbon). Older water and deeper wells, along with more water storage or slower water movement was associated with higher probability of anoxic conditions. Mapped model results illustrate regions where anoxic redox conditions may mobilize geogenic contaminants or oxic conditions may limit denitrification potential. Results may also provide simplified redox input for process or predictive models of, for example, arsenic, manganese, or nitrate. Machine learning modeling methods can lead to improved understanding of contaminant occurrence and what drives redox conditions, and the methods may be transferable to other settings. Plain Language Summary: This study created a three‐dimensional machine learning model, and then maps, of predicted redox conditions in the northern United States system of glacial aquifers. Reduction/oxidation (redox) processes and redox conditions are an important consideration for understanding water availability because redox conditions influence the mobility, transport and toxicity of common geologic‐sourced and human‐produced contaminants (e.g., arsenic and manganese, and nitrate, respectively). Previous studies show that in the northern United States system of glacial aquifers, high arsenic, and manganese concentrations from geologic materials occur primarily in groundwater under reducing conditions. The human‐sourced contaminant nitrate, however, is more common at high concentration in groundwater under more oxidizing conditions. Our model results can be used to better understand the occurrence of common contaminants such as arsenic, manganese, or nitrate—or as simplified redox input to process or other models to more easily and accurately predict contaminants. Key Points: Anoxic conditions, predicted within much of the saturated thickness in some of the study area, influence geogenic contaminant mobilizationOxic conditions, predicted within the entire saturated thickness of large portions of the study area, limit denitrification potentialAnoxic conditions relate to groundwater residence time and chemical reactivity as captured in variables like groundwater age or soil C [ABSTRACT FROM AUTHOR]

Abstract: Iodine monoxide and ozone measurements were taken using long‐path differential optical absorption spectroscopy along the Gulf of Mexico coast near Galveston, Texas, in spring/summer of 2016. During the eight‐week campaign, half of the days were characterized by O3 between 12 and 25 ppb. These air masses coincided with onshore flow and had measurable levels of IO, with an average daily maximum around 0.8 ppt and values as high as 2 ppt. The presence of IO indicates the influence of iodine chemistry which catalytically destroys O3. Using observed IO and NO2 levels, along with model HO2 data, an O3 destruction rate between 1.5 and 2 ppb/day was calculated. Assuming a background O3 level of 30 ppb, it is very likely that iodine chemistry is responsible for destroying enough O3 along a 10‐day back trajectory through the Gulf of Mexico to explain the low mixing ratios frequently experienced along the Texas coast. [ABSTRACT FROM AUTHOR]

Agricultural crops with a C4 photosynthetic pathway rapidly expanded across North America as early as 800 A.D. Their distribution continues to expand globally as demands for food and biofuel production increase. These systems are highly productive, having a significant impact on carbon and water exchange between the land and atmosphere. Here, we investigate the relative impact of agricultural C4 vegetation on the 13CO2 photosynthetic discrimination and atmospheric isotopic forcing in the upper Midwest, United States. We address three questions: (1) What is the relative importance of C3 and C4 species to the CO2 budget? (2) How do these different photosynthetic pathways influence the photosynthetic discrimination within this heterogeneous landscape? (3) To what extent does land use change (i.e., a change in C4 crops) impact atmospheric isotopic forcing and the isotopic signature of the atmosphere? These questions are addressed using measurements obtained from the University of Minnesota tall tower (244 m) trace gas observatory (TGO) over the growing seasons of 2007 and 2008 and are supported with scaled-up values of discrimination and isotopic forcing based on ecosystem-scale eddy flux observations and high-resolution land use data. Our land use analyses indicate that local and regional C4 production was higher by 10% in 2007 due to increased demand for biofuel. The 2007 growing season was also characterized by moderate drought as a consequence of low antecedent soil water content. Isotopic flux ratio measurements from TGO provide evidence that the increase in C4 land use and drier soil conditions of 2007 had a significant impact on the growing season 13CO2 photosynthetic discrimination, which ranged from 11.5 to 14.8 in 2007 and 12.4‰ to 17.4‰ in 2008. Isotopic partitioning indicated that C4 species accounted for about 20 to 40% of the growing season gross photosynthetic CO2 exchange. The isoforcing analysis revealed that C3 discrimination dominated the atmospheric δ13a budget, especially during spring and fall. Estimates of 13CO2 photosynthetic discrimination for this region support recently published isotope modeling studies that explicitly accounted for increases in C4 cropland, which has significant implications for estimating the terrestrial carbon sink strength based on inverse modeling techniques. [ABSTRACT FROM AUTHOR]

We have identified cDNAs and characterized the expression of 13 novel cytochrome P450 genes of potential importance in host colonization and reproduction by the California fivespined ips, Ips paraconfusus. Twelve are of the Cyp4 family and one is of the Cyp9 family. Following feeding on host Pinus ponderosa phloem, bark beetle transcript levels of several of the Cyp4 genes increased or decreased in males only or in both sexes. In one instance (IparaCyp4A5) transcript accumulated significantly in females, but declined significantly in males. The Cyp9 gene (Cyp9T1) transcript levels in males were > 85 000 × higher at 8 h and > 25 000 × higher at 24 h after feeding compared with nonfed controls. Transcript levels in females were approximately 150 × higher at 24 h compared with nonfed controls. Cyp4G27 transcript was present constitutively regardless of sex or feeding and served as a better housekeeping gene than β-actin or 18S rRNA for the real-time TaqMan polymerase chain reaction analysis. The expression patterns of Cyp4AY1, Cyp4BG1, and, especially, Cyp9T1 in males suggest roles for these genes in male-specific aggregation pheromone production. The differential transcript accumulation patterns of these bark beetle P450s provide insight into ecological interactions of I. paraconfusus with its host pines. [ABSTRACT FROM AUTHOR]

Abstract Earthworms provide a major potential source of alternative food for polyphagous predators, such as carabid beetles, that are natural enemies of slugs, aphids and other agricultural pests. Non-pest prey may foster larger numbers of natural enemies, which then help to control pests, or alternatively may help to divert the predators away from pest control. An earthworm-specific monoclonal antibody was developed to study carabid–earthworm interactions in the field and assess the role of earthworms as alternative prey. The antibody could identify as little at 7 ng of earthworm protein in an ELISA, and could detect earthworm remains in the foregut of the carabid beetle Pterostichus melanarius for 64 h after consumption. Thirty-six per cent of field-collected beetles contained earthworm remains. Quantities of earthworm proteins in the beetle foreguts were negatively related to total foregut biomass, suggesting that earthworm consumption increased as total prey availability declined. There was also a negative relationship between foregut biomass and beetle numbers, but both quantities and concentrations of earthworm proteins in beetle foreguts were positively related to beetle numbers. This suggests that as beetle activity–density increased, total prey availability declined, or, as prey availability declined, beetles spent more time searching. In these circumstances, beetles fed to a greater extent on earthworms, an acceptable but nonpreferred food item. Earthworms may, therefore, provide an ideal alternative prey for P. melanarius, helping to sustain it when pest numbers are low but allowing it to perform a ‘lying-in-wait’ strategy, ready to switch back to feeding on pests when they become available. [ABSTRACT FROM AUTHOR]

Methyl cellulose (MC) and hydroxypropylmethylcellulose (HPMC) edible film materials were applied to marinated whole chicken strips either prior to breading, after breading, or were incorporated in the breading. Subsequently, the influence of an edible film's location relative to the crust on fried food product quality and the quality of the frying oil were determined. Films applied to chicken strips prior to the breading had fried crusts with higher fat and lower moisture levels. Decreased degradation of frying oils was recorded when product coated with HPMC (food grade E4M) films had been fried compared to non-coated product. It is postulated that these edible films hindered the migration of moisture and acetic acid into the frying oil and this activity was responsible for reduced free fatty acid generation in those oils used to fry the coated products. [ABSTRACT FROM AUTHOR]

The maximum rate of rise of right ventricular pressure (RV dP/dtmax) may change in response to physiological stress and thereby provide an appropriate parameter upon which to base rate adaptive pacing. Initial feasibility testing was carried out in six patients using externally closed loop rate adaptive pacing with a pressure sensing lead (Model 6220) and an investigational VVI pulse generator (Medtronic, Model 2451). During exercise, maximum positive RV dP/dtmax increased from 223 ± 55 to 405 ± 181 mmHg·sec· (P < 0.05). Based on these results, rate adaptive pulse generators using maximum positive RV dP/dt were implanted in 12 patients (Medtronic, Model 2503). Exercise treadmill testing in the VVI mode resulted in heart rates ranging from 69 ± 6 beats/min at rest to 79 ± 14 beats/min (n = 12; P > 0.05). In contrast, VVIR mode pacing rates ranged from 71 ± 11 beats/min to 115 ± 24 beats/min (n = 17; P < 0.05). Holier recording showed heart rates ranging from 51 ± 6 to 110 ± 22 beats/min during activities of normal daily living (n = 9; P < 0.05). Passive postural tilt resulted in rates of 69 ± 8 beats/min in the supine position increasing to 74 ± 14 beats/min with 60° upright tilt (n = 16; P > 0.05). With up to 5-year follow-up data, there have been no late failures of pacing but one lead showed insulation failure with over- and undersensing after 4.5 years. A number of deficiencies were identified in the prototypes leading to modifications of a subsequent generation of rate responsive pacemaker based on .RV dP/dtmax. These initial data demonstrate that rate adaptive pacing based on RV dP/dtmax responds in a physiological manner. This rate responsive system is of particular interest as it is based on a beat-to-beat parameter of cardiac mechanical function. [ABSTRACT FROM AUTHOR]

Chronic exposure to arsenic (As) via drinking groundwater is a human health concern worldwide. Probabilities of elevated geogenic As concentrations in groundwater were predicted in complex, glacial aquifers in Minnesota, north‐central USA, a region that commonly has elevated As concentrations in well water. Maps of elevated As hazard were created for depths typical of drinking water supply and with well construction attributes common for domestic wells. Conventional variables describing aquifer properties and materials, position on the hydrologic landscape, and soil geochemistry were among the most influential for predicting the probability of elevated As. We also found that certain well construction attributes were influential in predicting As hazard. Smaller distances between the top of the well screen and overlying aquitard (proximity) and shorter well screen lengths were each associated with higher probabilities of elevated As. Influential predictor variables, which are either mapped across the region or are well construction attributes, are proxies in the model for measurable physical or geochemical causes of elevated As (e.g., redox condition, till or aquifer sediment chemistry, and water chemistry), which are not mapped across the region. Our setting shares some important characteristics with deltaic and other high‐As aquifers in Southeast Asia: late Quaternary age, complex layering of coarse‐ and fine‐grained materials, low‐As sediment concentrations, and geochemical controls on As mobilization. Translating three‐dimensional geologic and geochemical understanding of As mobility to quantifiable variables for modeling with powerful, flexible statistical tools could improve predictions and help identify safer groundwater supply options in the USA, Southeast Asia, and elsewhere. Plain Language Summary: This study demonstrates that certain well construction attributes are influential in predicting arsenic (As) concentrations in drinking water wells. Smaller distances between the top of the well screen and overlying aquitard, and shorter well screen lengths, were each associated with higher probabilities of elevated As. Chronic exposure to As via drinking groundwater is a human health concern worldwide, and Minnesota, USA, commonly has elevated As concentrations in well water. This study describes a new, novel, and important finding from an As probability model: Controllable well construction choices (not just location or depth) influence As concentrations in drinking water from wells. Key Points: Developed successful probability model of elevated geogenic groundwater As concentrations in complex, glacial aquifers in Minnesota, USASetting has similar features to deltaic and other high‐As aquifers: age, layering, low‐As sediment, and geochemical control of As mobilizationControllable factors (well screen proximal to aquitard and shorter well screen length) were associated with higher likelihood of elevated As [ABSTRACT FROM AUTHOR]

Refractive index (RI) matching is a unique way of making clear emulsions to meet market trends. However, RI matching has not been sufficiently investigated in terms of physical principles and methodologies. Snell's law ( n2 sin r2 = n1 sin r1) is applicable to cosmetic emulsions. When oil phase and water phase have equal RI ( n2 = n1) values, light will not bend as it strikes obliquely at the emulsion interface. Instead, light is transmitted through the emulsion without refraction, which produces clarity. Theoretical RI values in solution can be calculated with summation of the product of the weight percentage and refractive index of each ingredient ( RImix = [ W1 × n1 + W2 × n2 + W3 × n3 + + Wn × nn]/ WT). Oil-phase RI values are normally at 1.4 or higher. Glycols are used to adjust the water phase RI, since they typically have larger RI values than water. Noticeable deviations from calculated RI values are seen in experimentally prepared solutions. Three basic deviation types are observed: negative, positive, and slightly negative or positive, which can occur in glycol aqueous solutions at different concentrations. The deviations are attributed to changes in molecular interaction between molecules in solution, which can lead to changes in specific gravity. Negative RI deviation corresponds to a decrease in specific gravity, and positive RI deviation corresponds to an increase in specific gravity. RI values will deviate from calculated values since an increase or decrease in specific gravity leads to a change in optical density. [ABSTRACT FROM AUTHOR]

An abstract of the study "The Safety and Efficacy of Repeated Doses of Levosimendan in Patients With Advanced Heart Failure," by N. M. Parle and colleagues is presented.

Background & Aims: Fibrosis stage is a strong predictor of nonalcoholic steatohepatitis (NASH) outcomes. Two blinded studies evaluated the pharmacokinetics, pharmacodynamics and safety of obeticholic acid (OCA) in subjects with staged NASH fibrosis or cirrhosis., Methods: Study 747-117 randomized 51 subjects with NASH (fibrosis stages F1-F4) to daily placebo, OCA 10 or OCA 25 mg (1:2:2) for 85 days. Study 747-118 randomized 24 subjects with NASH cirrhosis (F4; Child-Pugh [CP]-A) and normal liver control subjects matched for similar body weight to daily OCA 10 or OCA 25 mg (1:1) for 28 days. Individual and combined study data were analysed., Results: No severe or serious adverse events (AEs) or AEs leading to discontinuation or death occurred. Pruritus was the most frequent AE. Plasma OCA exposure (dose-normalized area under the curve) increased with fibrosis stage but was a relatively poor predictor of hepatic OCA exposure (primary site of action), which remained constant across fibrosis stages F1-F3 and increased 1.8-fold compared with F1 in subjects with cirrhosis due to NASH. Both cohorts showed robust changes in farnesoid X receptor activation markers with OCA treatment and marked decreases in alanine transaminase, aspartate transaminase and gamma-glutamyltransferase., Conclusions: Despite higher drug exposures in subjects with NASH cirrhosis, short-term daily treatment with OCA 10 or 25 mg was generally safe and well tolerated in subjects with NASH fibrosis or NASH CP-A cirrhosis. Both cohorts experienced improvements in nonhistologic pharmacodynamic markers consistent with previously conducted OCA phase 2 and phase 3 studies in NASH fibrosis., (© 2024 Intercept Pharmaceuticals. Liver International published by John Wiley & Sons Ltd.)

OBJECTIVES. Deficits in metacognition, or the ability to think about thinking, are common in schizophrenia and associated with functional impairment. Unknown are what elements of function are affected by what aspects of metacognition. DESIGN. This study explored whether participants with differing capacities for Mastery, a domain of metacognition that reflects the ability to use knowledge about mental states to respond to psychological challenges, had difficulties in different elements of daily function. METHODS. Participants were 98 adults with schizophrenia or schizoaffective disorder in a non-acute phase, classified into three groups on the basis of ratings of their capacity for metacognitive Mastery using the Metacognitive Assessment Scale: low Mastery (those unable to plausibly represent psychological challenges), Intermediate Mastery (those able to plausibly represent psychological problems but cope primarily through passive measures or avoidance), and high Mastery (those able to cope with plausible problems through cognitive means). Participants completed assessments of coping preference, insight, self-esteem, and anxiety. RESULTS. Multivariate Analysis of Variance (MANOVA) and Analysis of Variance (ANOVA) revealed that the high-Mastery group had a greater preference for coping with stressors by thinking and talking about them, and greater insight than all other groups, and higher levels of feeling accepted by peers than the intermediate-Mastery group. The intermediate-Mastery group reported higher levels of resignation when facing stressors and more social phobia than the other two groups. These findings of Mastery group differences in self-esteem and anxiety persisted when neurocognition was controlled for in an Analysis of Covariance (ANCOVA). CONCLUSIONS. Mastery appears linked to coping preference, insight, self-esteem, and anxiety in a generally non-linear manner., (©2011 The British Psychological Society.)

Estimates of observer agreement are necessary to assess the acceptability of interval data. A common method for assessing observer agreement, per cent agreement, includes several major weaknesses and varies as a function of the frequency of behavior recorded and the inclusion or exclusion of agreements on nonoccurrences. Also, agreements that might be expected to occur by chance are not taken into account. An alternative method for assessing observer agreement that determines the exact probability that the obtained number of agreements or better would have occurred by chance is presented and explained. Agreements on both occurrences and nonoccurrences of behavior are considered in the calculation of this probability.