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The authors demonstrate an all-optical method to control the polarization of light. Harnessing the Kerr nonlinearity in an optical resonator, this enables precise polarization control in photonic circuits.

Background: Racism is a public health crisis impacting the health and wellbeing of adolescents. Finding valid tools to measure race-based discrimination, a form of racism, is necessary to accurately assess the effectiveness of programs aimed to reduce those experiences. Objectives: Our objective was to evaluate measurement invariance of a race-based discrimination scale by gender among a sample of youth (ages 13-19) from historically marginalized groups and to assess associations of race-based discrimination with sexual violence victimization and perpetration. Methods: We used pooled cross-sectional baseline data from two sexual violence prevention programs from 2015 to 2019. Male and female participants were from Manhood 2.0 (a cluster randomized trial) and Sisterhood 2.0 (a quasi-experimental study), respectively. All participants were recruited through community organizations from the same neighborhoods. In this study, we included all non-white youth with completed responses to the 10-item Perceptions of Racism in Children and Youth (PRaCY) Scale. This study was approved by the University of Pittsburgh IRB. Results: We conducted confirmatory factor analysis (N = 749) and measurement invariance among male-identifying (n = 560) and female-identifying (n = 189) participants resulting in a unidimensional factor structure with weak factorial invariance by gender. Lifetime discriminatory experiences were common among all participants. Mean discrimination scores were associated with a significant increase in the odds of lifetime sexual violence victimization in males (OR = 3.03, 95%CI 1.43-6.42) and females (OR = 10.80, 95% CI 2.23-52.33), respectively. Conclusion: We confirmed construct validity of the PRaCY Scale among youth experiencing marginalization and found associations between experiences of discrimination and sexual violence victimization in both boys and girls.

Given the developmental benefits associated with higher sense of purpose, past work has aimed to understand how experiences of adversity relate to sense of purpose. With a specific focus on experiences of adversity that may impact individuals from marginalized groups, past work has found that discrimination is related to lower sense of purpose in life, but that these effects are weaker for Black adults relative to White adults. The current research aims to extend past work by examining how and for whom discrimination is related to sense of purpose in life. Moreover, the current work also aimed to understand the extent to which sense of purpose spans across generations and whether there are generational differences in the relationship between discrimination and sense of purpose. Using data from the St. Louis Personality and Aging Network study, 822 parents (G1 participants) and 654 children (G2 participants) completed measures for sense of purpose, major experiences of discrimination, and personality traits. Results found mixed evidence for a relationship between discrimination and sense of purpose, with little evidence for consistent moderators. In addition, while the current work found no evidence of intergenerational associations for sense of purpose, results showed that discrimination was positively associated across generations, suggesting a potential for an intergenerational cycle of marginalization.

Supporting student wellbeing in schools is increasingly becoming a global priority. However, research and initiatives primarily focus on general wellbeing rather than subject-specific experiences. Given the pervasive levels of mathematics anxiety, negative attitudes, and disengagement in mathematics education, we argue for a more contextualised wellbeing approach. We define 'mathematical wellbeing' (MWB) as the fulfilment of values whilst learning mathematics accompanied by positive feelings (e.g., enjoyment) and functioning (e.g., engagement) in the discipline. We report on 3073 New Zealand Year Three to Eight students' responses to a survey measuring their fulfilment of seven MWB values: accomplishments, cognitions, engagement, meaning, perseverance, positive emotions, and relationships. Students' MWB was highest for relationships and perseverance and lowest for engagement and positive emotions; MWB declined from Years Three to Eight; females often rated higher MWB than males; school sociodemographic status was mostly not significant, whilst engagement and positive emotions differed across ethnicities. Research implications include understanding target areas to improve diverse students' experiences and wellbeing in mathematics education.

Many scientists have begun to refer to the earth surface environment from the upper canopy to the depths of bedrock as the critical zone (CZ). Identification of the CZ as an integral object worthy of study implicitly posits that the study of the whole earth surface will provide benefits that do not arise when studying the individual parts. To study the CZ, however, requires prioritizing among the measurements that can be made – and we do not generally agree on the priorities. Currently, the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO) is expanding from a small original focus area (0.08 km2, Shale Hills catchment), to a larger watershed (164 km2, Shavers Creek watershed) and is grappling with the prioritization. This effort is an expansion from a monolithologic first-order forested catchment to a watershed that encompasses several lithologies (shale, sandstone, limestone) and land use types (forest, agriculture). The goal of the project remains the same: to understand water, energy, gas, solute, and sediment (WEGSS) fluxes that are occurring today in the context of the record of those fluxes over geologic time as recorded in soil profiles, the sedimentary record, and landscape morphology. Given the small size of the Shale Hills catchment, the original design incorporated measurement of as many parameters as possible at high temporal and spatial density. In the larger Shavers Creek watershed, however, we must focus the measurements. We describe a strategy of data collection and modeling based on a geomorphological and land use framework that builds on the hillslope as the basic unit. Interpolation and extrapolation beyond specific sites relies on geophysical surveying, remote sensing, geomorphic analysis, the study of natural integrators such as streams, groundwaters or air, and application of a suite of CZ models. We hypothesize that measurements of a few important variables at strategic locations within a geomorphological framework will allow development of predictive models of CZ behavior. In turn, the measurements and models will reveal how the larger watershed will respond to perturbations both now and into the future.

Current childhood obesity treatment programs do not address medically underserved populations or settings where all members of an interdisciplinary team may not exist - either within one organization or within the community. In this paper, we describe the use of a community-academic partnership to iteratively adapt Epstein's Traffic Light Diet (TLD), into Building Healthy Families (BHF), a community-placed evidence-based pediatric weight management intervention (PWMI) and evaluate its effectiveness in reducing BMI z scores. Nine cohorts of families completed BHF. Participants included children aged 6-12 years with obesity (M = 9.46, SD = 1.74). The Framework for Reporting Adaptations and Modifications-Expanded guided our classification of modifications across BHF cohorts. Using the FRAME reporting structure, the changes that were documented were (1) planned and occurred pre-implementation, (2) based on decisions from local stakeholders (e.g., school administrator, members of the implementation team), and (3) specific to changes in content and context - with a focus on implementation and potential for local scale-up. The nature of the adaptations included adding elements (whole of family approach), removing elements (calorie counting), and substituting elements (steps for minutes of physical activity). Across 9 cohorts, 84 families initiated the BHF program, 69 families successfully completed the 12-week program, and 45 families returned for 6-month follow-up assessments. Results indicated that the BMI z score in children was reduced by 0.31 ± 0.17 at 6 months across all cohorts. Reduction in BMI z score ranged from 0.41 in cohort 4 to 0.13 in cohort 5. Iterative adaptations to BHF were completed to improve the fit of BHF to the setting and participants and have contributed to a sustained community PWMI that adheres to the underlying principles and core elements of other evidence-based PWMIs. Monitoring adaptations and related changes to outcomes can play a role in long-term sustainability and effectiveness.

Despite the value of sense of purpose during older adulthood, this construct often declines with age. With some older adults reconsidering the relevance of purpose later in life, the measurement of purpose may suffer from variance issues with age. The current study investigated whether sense of purpose functions similarly across ages and evaluated if the predictive power of purpose on mental, physical, cognitive, and financial outcomes changes when accounting for a less age-affected measurement structure. Utilizing data from two nationwide panel studies (Health and Retirement Study: n = 14,481; Midlife in the United States: n = 4,030), the current study conducted local structural equation modeling and found two factors for the positively and negatively valenced purpose items in the Purpose in Life subscale (Ryff, 1989), deemed the purposeful and purposeless factor. These factors become less associated with each other at higher ages. When reproducing past findings with this two-factor structure, the current study found that the purposeful and purposeless factors predicted these outcomes in the same direction as would be suggested by past research, but the magnitude of these effects differed for some outcomes. The discussion focuses on the implications of what this means for our understanding of sense of purpose across the lifespan.

The water quality of rainfall and runoff is described for two catchments of two tributaries of the River Thames, the Pang and Lambourn. Rainfall chemistry is variable and concentrations of most determinands decrease with increasing volume of catch probably due to 'wash out' processes. Two rainfall sites have been monitored, one for each catchment. The rainfall site on the Lambourn shows higher chemical concentrations than the one for the Pang which probably reflects higher amounts of local inputs from agricultural activity. Rainfall quality data at a long-term rainfall site on the Pang (UK National Air Quality Archive) shows chemistries similar to that for the Lambourn site, but with some clear differences. Rainfall chemistries show considerable variation on an event-to-event basis. Average water quality concentrations and flow-weighted concentrations as well as fluxes vary across the sites, typically by about 30%. Stream chemistry is much less variable due to the main source of water coming from aquifer sources of high storage. The relationship between rainfall and runoff chemistry at the catchment outlet is described in terms of the relative proportions of atmospheric and within-catchment sources. Remarkably, in view of the quantity of agricultural and sewage inputs to the streams, the catchments appear to be retaining both P and N. Keywords: water quality, nitrate, ammonium, phosphorus, ammonia, nitrogen dioxide, pH, alkalinity, nutrients, trace metals, rainfall, river, Pang, Lambourn, LOCAR

The water quality of the Pang and Lambourn, tributaries of the River Thames, in south-eastern England, is described in relation to spatial and temporal dimensions. The river waters are supplied mainly from Chalk-fed aquifer sources and are, therefore, of a calcium-bicarbonate type. The major, minor and trace element chemistry of the rivers is controlled by a combination of atmospheric and pollutant inputs from agriculture and sewage sources superimposed on a background water quality signal linked to geological sources. Water quality does not vary greatly over time or space. However, in detail, there are differences in water quality between the Pang and Lambourn and between sites along the Pang and the Lambourn. These differences reflect hydrological processes, water flow pathways and water quality input fluxes. The Pang’s pattern of water quality change is more variable than that of the Lambourn. The flow hydrograph also shows both a cyclical and 'uniform pattern' characteristic of aquifer drainage with, superimposed, a series of 'flashier' spiked responses characteristic of karstic systems. The Lambourn, in contrast, shows simpler features without the 'flashier' responses. The results are discussed in relation to the newly developed UK community programme LOCAR dealing with Lowland Catchment Research. A descriptive and box model structure is provided to describe the key features of water quality variations in relation to soil, unsaturated and groundwater flows and storage both away from and close to the river. Keywords: water quality, nitrate, ammonium, phosphorus, pH, alkalinity, nutrients, major elements, trace elements, rainfall, river, Pang, Lambourn, LOCAR

The water quality of the Nant Tanllwyth stream in the Plynlimon region of mid-Wales is related to the key hydrobiogeological controls and the effects of conifer harvesting based on an analysis of rain, cloud, stream and groundwater measurements. The results show the normal patterns of stream water quality response to hydrology. Thus, there is a high damping of atmospheric inputs due to storage in a highly heterogeneous soil and groundwater system. Correspondingly, there is a highly dynamic response for components such as calcium, bicarbonate and aluminium. This response links to the relative inputs of acidic and aluminium-bearing soil waters under high flow conditions and base enriched bicarbonate bearing waters from the groundwater areas under baseflow conditions. The introduction of a deep borehole near the main stem of the river opened up a groundwater flow route to the stream and other parts of the catchment. There were two aspects to this. Firstly, it caused a change to the stream water quality, particularly under baseflow conditions, by increasing the concentrations of calcium and magnesium and by reducing the acidity. The monitoring shows that this change has persisted for over eight years and that there is no sign of reversion to pre-borehole times. Secondly, it caused a change in the groundwater level and chemistry at a borehole on the other side of the river. This feature shows that the fracture system is of hydrogeochemical and hydrogeological complexity. The effects of conifer harvesting are remarkable. At the local scale, felling leads to the expected short term increase in nitrate, ammonium and phosphate from the disturbance of the soil and the reduction in uptake into the vegetation. Correspondingly, there is a reduction in sodium and chloride linked to reduced scavenging of atmospheric inputs from cloud water by the vegetation and also due to increased dilution potential due to reductions in transpiration by the trees. However, within the main stream, virtually no change is observed in stream water quality with felling, except for a decrease rather than an expected increase in nitrate concentration. It seems that the increase in phosphate, for a system that is essentially phosphate limiting, has stimulated biological activity in the stream leading to increased uptake of nitrate and ammonium. However, there is little change in the sodium and chloride in the stream and there are important issues of the representative nature of studying small scale drainage areas. Boreholes, introduced to assess the impacts of the felling programme, show unexpected variations in groundwater chemistry. These variations are associated with the complexity of both flow routing and the chemical reactivity within the groundwater and lower soil zones, rather than changes that can be linked specifically to felling. The implications of the study are discussed in relation to both process understanding and forestry management practices. Keywords: water quality, acidification, conifer, harvesting, pH, nitrate, ammonium, phosphate, nutrients, alkalinity, Plynlimon, Wales, Tanllwyth, streams, groundwater

Results for long term water quality monitoring are described for the headwaters of the principal headwater stream of the River Severn, the Afon Hafren. The results are linked to within-catchment information to describe the influence of conifer harvesting on stream and shallow groundwater quality. A 19-year record of water quality data for the Hafren (a partially spruce forested catchment with podzolic soil) shows the classic patterns of hydrochemical change in relation to concentration and flow responses for upland forested systems. Progressive felling of almost two-thirds of the forest over the period of study resulted in little impact from harvesting and replanting in relation to stream water quality. However, at the local scale, a six years’ study of felling indicated significant release of nitrate into both surface and groundwater; this persisted for two or three years before declining. The study has shown two important features. Firstly, phased felling has led to minimal impacts on stream water. This contrasts with the results of an experimental clear fell for the adjacent catchment of the Afon Hore where a distinct water quality deterioration was observed for a few years. Secondly, there are localised zones with varying hydrology that link to groundwater sources with fracture flow properties. This variability makes extrapolation to the catchment scale difficult without very extensive monitoring. The implications of these findings are discussed in relation to strong support for the use of phased felling-based management of catchments and the complexities of within catchment processes. Keywords: deforestation, water quality, acidification, pH, nitrate, alkalinity, ANC, aluminium, dissolved organic carbon, Plynlimon, forest, spruce, Afon Hafren, podzol

Long term changes in the water quality of rainfall, cloud water and stream waters draining acidic and acid sensitive moorland and forested catchments at Plynlimon, mid-Wales, are examined for the period 1983 to 2001. Atmospheric inputs of chloride and sulphate are influenced by the relative inputs of clean maritime and polluted land based air masses. There is no systematic increase or decrease over time for chloride and non-sea-salt sulphate. Rather, there is a decadal scale process possibly representative of the influence of the North Atlantic Oscillation that affects the maritime and pollution climate of the Atlantic seaboard of the UK. Over 17 years of study, there may be a small decrease in non-sea-salt sulphate of about 10 μeq l-1 and a small improvement in acid neutralising capacity of about 20 to 30 μeq l-1 in rainfall. There is a clear improvement in cloud water chemistry with respect to pollutant components (ammonium, nitrate, non-sea-salt sulphate) and acidity (acid neutralising capacity improved by about 300 μeq l-1) through the study period. Many of the changes in cloud water chemistry are similar to rainfall over the same period except the magnitude of change is larger for the cloud water. Within the streams, there is some evidence for reductions in acidity as reflected by acid neutralising capacity becoming less negative. For one stream, deforestation occurred during the sampling period and this led to large increases in nitrate and smaller increases in aluminium midway through the study period. However, the climate and hydrological variability largely masked out other changes. The current analysis provides only a start to identifying trends for such a complex and variable environmental system. The need for strong statistical tools is emphasised to resolve issues of: (a) hydrological induced water quality variability, (b) changing soil and groundwater "endmember" chemistry contribution to the stream and (c) the non-linear patterns of change. Nonetheless, the analysis is enhanced by examining trends in chemistry for yearly averages and yearly average low catch and high catch rainfall and cloud water events as well as low and high flow stream chemistry. This approach allows trends to be examined within the context of endmember mixing. Keywords: Calcium, aluminium, ammonium, pH, Gran alkalinity, ANC, nitrate, chloride, sulphate, Plynlimon, cloud, mist, rainfall, stream, acidification, North Atlantic Oscillation, trends

Water quality data spanning 13 years and covering an extensive range of major, minor and trace elements in rain and stream waters at Plynlimon in mid Wales, are presented. Rainfall water chemistry is highly variable due to varying proportions of marine and pollutant derived constituents associated with patterns of atmospheric circulation. Stream waters, being composed of different proportions of waters from three chemically distinct sources at any one time (atmospheric deposition, the soil system and deeper groundwaters), are also chemically highly variable. For example, components predominantly derived from deposition such as chloride change only in response to sea-salt deposition episodes. Solutes associated with bedrock weathering such as calcium, magnesium, and alkalinity decrease with increasing flow, those associated with the upper soil layers such as aluminium, many transition metals, dissolved organic carbon and hydrogen ions increase with increasing flow. The nutrients (e.g. nitrate, boron, bromide and iodine) exhibit strong seasonal cycles associated with cycles of vegetation growth and decay. The changes in stream water chemistry resulting from tree harvesting in the Afon Hore catchment are shown to have run their course within a period of eight years. Nutrient increases in the first few years following the commencement of felling have returned to or fallen below pre-felling values. Aluminium changes are shown to be complicated by changes in nitrate and calcium. Aluminium concentrations initially increased and have fallen below their pre-felling value. Data for chloride suggest a reduction in capture of dry and mist deposition; this indicates the importance of understanding reduced deposition as a result of felling. Felling has also affected the soil micro-climate which experiences greater fluctuations in temperature and an increase in the concentration of constituents associated with organic matter. Input-output mass balance estimates show that atmospheric inputs of many constituents are retained strongly by the catchment (e.g. ammonium, phosphate, barium, boron, lead and iodine). In contrast, many of the transition elements as well as divalent base cations, aluminium and alkalinity show a net release from the catchment. Conservative constituents such as chloride and sodium show a net input-output balance.

Gastrointestinal (GI) dysfunction is a common comorbidity of autism spectrum disorders (ASD) and is associated with increased severity of characteristic autism-associated symptoms. However, the underlying biological mechanisms for GI dysfunction symptoms in children with ASD are unknown. This review explores potential explanations for these symptoms including altered enteric microbiota, impaired intestinal permeability, changes in immune homeostasis, and genetic factors such as single nucleotide polymorphisms. It was shown that genetic factors not only influence the development of altered enteric microbiota and impaired intestinal permeability, but also are a strong, independent contributor to GI dysfunction in ASD patients.