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The plasma amino acid profiles of 10 children with autism on gluten and casein restricted diets and 26 on unrestricted diets were reviewed. There was a trend for the children on restricted diets to have an increased prevalence of essential amino acid deficiencies and lower plasma levels of essential acids. (Contains references.) (Author/CR)

Anthropogenic salt sources have contributed to rising salinities in the Laurentian Great Lakes. In Lake Michigan, chloride concentrations have risen from ~ 1–2 mg L−1 in the 1800s to > 15 mg L−1 in 2020. The watersheds of the approximately 300 tributaries of Lake Michigan vary in size and represent a wide range of land use, from undeveloped forested watersheds to urbanized and agricultural areas. The spatial variability in both size and land cover among Lake Michigan's tributaries contributes to enormous variation in chloride concentrations and loads. We performed a spatial assessment of Lake Michigan tributaries to calculate total annual salt loading, infer future conditions based on current patterns, evaluate the use of synoptic sampling, and identify watershed characteristics that drive high chloride concentrations. We found that the tributary load to Lake Michigan is 1.08 Tg yr−1 of chloride, and that chloride concentrations in Lake Michigan will likely continue to slowly rise in the coming decades. [ABSTRACT FROM AUTHOR]

Several protein tyrosine phosphatases (PTPs) expressed in insulin sensitive-tissues are proposed to attenuate insulin action and could act as key regulators of the insulin receptor (IR) signaling pathway. Among these [...]

Introduction Harmful effects of exposure to elevated lead (Pb) levels on human health have been well documented. In particular, the skeletal system is thought to be at higher susceptibility to [...], BACKGROUND: Lead (Pb) exposure and obesity are co-occurring risk factors for decreased bone mass in the young, particularly in low socioeconomic communities. OBJECTIVES: The goal of this study was to determine whether the comorbidities of Pb exposure and high-fat diet-induced obesity amplify skeletal deficits independently associated with each of these risk factors, and to explore associated mechanisms of the observed deficiencies. METHODS: Five-week-old male C57BL/6J mice were placed on low-fat (10% kcal, LFD) or high-fat (60% kcal, HFD) diets for 12 weeks. Mice were exposed to lifetime Pb (50 ppm) through drinking water. RESULTS: HFD was associated with increased body mass and glucose intolerance. Both HFD and Pb increased fasting glucose and serum leptin levels. Pb and HFD each reduced trabecular bone quality and together had a further detrimental effect on these bone parameters. Mechanical bone properties of strength were depressed in Pb-exposed bones, but HFD had no significant effect. Both Pb and HFD altered progenitor cell differentiation, promoting osteoclastogenesis and increasing adipogenesis while suppressing osteoblastogenesis. In support of this lineage shift being mediated through altered Wnt signaling, Pb and non-esterified fatty acids in MC3T3 cells increased in vitro PPAR-γ activity and inhibited β-catenin activity. Combining Pb and non-esterified fatty acids enhanced these effects. CONCLUSIONS: Pb and HFD produced selective deficits in bone accrual that were associated with alterations in progenitor cell activity that may involve reduced Wnt signaling. This study emphasizes the need to assess toxicants together with other risk factors relevant to human health and disease. http://dx.doi.org/10.1289/ehp.l408581

Dissolved organic matter (DOM) is a complex mixture of many compounds and its composition dictates numerous reactions in the environment. Large lakes and marine coastlines receive DOM from watersheds that differ widely in their land cover, with potential implications for both the quantity and composition of carbon inputs. Seasonal variation in DOM quantity and composition may also differ among tributaries and be mediated by land cover. Here, we quantify spatially (i.e., among tributary) and seasonal variation in DOM concentration, DOM composition based on ultraviolet‐visible spectroscopy, and alkalinity across 101 tributaries of Lake Michigan, one of the world's largest lakes, using a synoptic sampling approach. Wetland land cover has the largest effect on DOM, producing high concentrations of DOM that are more aromatic and larger in apparent molecular weight. Seasonal variation is also pronounced, with concentrations and aromaticity of DOM peaking in fall across most tributaries. Watershed lithology and land cover both affect alkalinity, with higher values associated with the geography of carbonate bedrock and urbanized watersheds. Watershed land cover has a larger effect than season on all organic carbon parameters. However, seasonal variation is especially important for DOM composition. This disparity suggests that the environmental processing of DOM within river channels mediates its composition more than its concentrations. Considering the wide range of land cover and lithology around Lake Michigan and other large water bodies, accounting for both spatial and seasonal dynamics is essential for understanding controls on DOM delivery. Plain Language Summary: Tributaries carry important inputs of water, nutrients, and contaminants to the Great Lakes. We sampled >100 tributaries of Lake Michigan in each season to determine how the type of land surrounding each tributary affects the carbon it brings to Lake Michigan. We considered organic carbon concentration and composition, as well as alkalinity. Wetlands had the largest effect on organic carbon with tributaries from wetland‐dominated areas having a higher concentration of organic carbon and organic carbon composition consistent with that originating from the land. Both land cover and geology impact alkalinity with the amount of carbonate species underlying the watershed increasing the alkalinity in the tributary. The season of sample collection is significant for organic carbon but not for alkalinity. Additionally, the season of sample collection has a greater impact on organic carbon composition than it does on concentration. These results yield information about how the broader carbon cycle may be affected as a result of changing landscape types. Key Points: Concentrations of dissolved organic matter (DOM) range widely among tributaries of Lake Michigan, peaking in wetland‐dominated watersheds and during the fall seasonDOM is smaller in molecular weight and less aromatic in watersheds with little wetland land cover type and in the spring season, whereas alkalinity is positively correlated to urban land cover as well as underlying carbonate geologyDOM composition varies more in time (i.e., among seasons) than does either organic carbon concentrations or alkalinity [ABSTRACT FROM AUTHOR]

Presents a nonmathematical approach to help students understand that there are two types of coherence and to associate coherence as a property of the illumination at an object itself. The approach also lends itself to an introduction to the Fourier approach for analyzing imaging systems. (JN)

To provide an activity illustrating why they encounter conceptual difficulties in physics, students constructed a "world map" of physics which defines various "seas" and illustrates relationships between them. Salient features of this approach and physics concepts fostered are included. (JN)

Examines the effects of goal specificity and difficulty in the performance of badminton skills in children in Scotland. Attempts to control the effects of social comparison; Reference to the Locke's goal setting theory; Demonstration of staying power required to persevere with a task over time.