Black Adolescent Self-Perceptions: The Roles of Ethnic Identity and Stress Exposure.

Ethnic identity is associated with various positive outcomes for Black adolescents, but more information is needed about its potential to protect adolescents exposed to stress. Stressful life events predict a range of health outcomes, yet few studies have examined their association with adolescent self-perception. Ethnic identity may serve as protection from stress. This study examines longitudinal data to understand relationships between ethnic identity, stressful life events, and self-perception (i.e., social competence, behavioral conduct, and global self-worth). The sample included 140 adolescents (65% female; 93% Black) with an average age of 12.55 (SD = 0.85). Results indicate stressful life events are associated with behavioral conduct self-perception, and ethnic identity is associated with global self-worth. Ethnic identity behavior and other group orientation are associated with self-perception. Ethnic identity and ethnic identity behavior moderate the relationship between stressful life events and behavioral conduct self-perception. Understanding the connections between adolescent stressors and strengths provides insight into research, practice, and policy directions to promote positive outcomes.

Sports Participation, Frequency, and Competence Differentially Impact Youth Depressive, Anxious, and Somatic Symptoms: Gender, Neighborhood, and Sports Type Effects.

Mental health problems are prevalent in adolescence, but sports participation may offer mental health benefits through this developmental period and beyond. Characteristics of sports participation including perceived frequency and competence may differentially predict adolescent depressive, anxious, and somatic symptoms over time and results may further vary according to gender, neighborhood context, and type of sport engagement. Data were collected at two time-points six months apart from an ethnically diverse sample of adolescents (N = 183, female = 51%). Youth sports participation and symptoms were measured using the Youth Self-Report (YSR; Achenbach & Rescorla, 2001). Path analyses were used to test for main and moderating effects of sports on symptoms. Results showed that categorical sports participation did not prospectively predict any type of internalizing symptoms, but perceived frequency and competence did. Competence predicted lower levels of symptoms while frequency predicted higher levels of symptoms. These results were further moderated by gender, neighborhood, and sport type such that frequency and competence predicted symptoms for girls and for youth in more resourced neighborhoods and who participated in team sports. These findings highlight the impact that sports participation can have on adolescent mental health in an ethnically diverse sample of urban youth.

New Insights into the Phototoxicity of Anthracene-Based Chromophores: The Chloride Salt Effect†.

Unraveling the causes underlying polycyclic aromatic hydrocarbon phototoxicity is an essential step in understanding the harmful effects of these compounds in nature. Toward this end, we have studied the DNA interactions and photochemistry of N1-(anthracen-9-ylmethyl)ethane-1,2-diaminium dichloride in the presence and absence of NaF, KF, NaCl, KCl, NaBr, KBr, NaI, and KI (350 nm hν, pH 7.0). Exposing pUC19 plasmid to UV light in solutions containing 400 mM KCl formed significantly more direct strand breaks in DNA compared to no-salt control reactions. In contrast, NaCl increased DNA damage moderately, while the sodium(I) and potassium(I) fluoride, bromide, and iodide salts generally inhibited cleavage (I- > Br- > F-). A halide anion-induced heavy-atom effect was indicated by monitoring anthracene photodegradation and by employing the hydroxyl radical (•OH) probe hydroxyphenyl fluorescein (HPF). These studies revealed that among no-salt controls and the eight halide salts, only NaCl and KCl enabled the anthracene to photosensitize the production of high levels of DNA-damaging reactive oxygen species (ROS). Pre-irradiation of N1-(anthracen-9-ylmethyl)ethane-1,2-diaminium dichloride at 350 nm increased the amounts of chloride salt-induced •OH detected by HPF in subsequent anthracene photoactivation experiments. Taking into consideration that •OH and other highly reactive ROS are extremely short-lived, this result suggests that the pre-irradiation step might lead to the formation of oxidized anthracene photoproducts that are exceedingly redox-active. The fluorometric probes HPF and Singlet Oxygen Sensor Green revealed that KCl concentrations ranging from 150 to 400 mM and from 100 to 400 mM, respectively, enhanced N1-(anthracen-9-ylmethyl)ethane-1,2-diaminium dichloride photosensitized •OH and singlet oxygen (1O2) production over no-salt controls. Considering the relatively high levels of Na+, K+, and Cl- ions that exist in the environment and in living organisms, our findings may be relevant to the phototoxic effects exhibited by anthracenes and other polycyclic hydrocarbons in vivo.

Latinx adolescents' trust in adults: A precursor to psychological well-being via mentoring relational quality and self-esteem.

This study aimed to test a longitudinal model of trust in adults and psychological well-being among Latinx adolescents, a population that has received little attention in the trust literature. The participants were urban, low-income Latinx (N = 294) students at two urban, Midwestern high schools who indicated they had at least one natural mentor in 9th grade. Participants completed surveys at two-time points, in 9th and 10th grade, and responded to measures of their feelings toward adults, quality of their natural mentoring relationships, self-esteem, intrinsic academic motivation, and coping self-efficacy. More trust in adults was indirectly, but not directly, associated with higher coping self-efficacy via higher mentoring relational quality and self-esteem. Positive expectations of adults may open Latinx youth to closeness in natural mentoring relationships and positive self-perceptions, which may, in turn, bolster coping ability.

DNA Photocleavage in the Near-Infrared Wavelength Range by 2-Quinolinium Dicarbocyanine Dyes.

Here, we report the syntheses of two pentamethine cyanine dyes containing quinolinium rings and substituted with either hydrogen (3) or bromine (4) at the meso carbon. The electron withdrawing bromine atom stabilizes dye 4 in aqueous buffer, allowing complex formation to occur between the dye and double-helical DNA. UV-visible, CD, and fluorescence spectra recorded at low DNA concentrations suggest that dye 4 initially binds to the DNA as a high-order aggregate. As the ratio of DNA to dye is increased, the aggregate is converted to monomeric and other low-order dye forms that interact with DNA in a non-intercalative fashion. The brominated dye 4 is relatively unreactive in the dark, but, under 707-759 nm illumination, generates hydroxyl radicals that cleave DNA in high yield (pH 7.0, 22 °C). Dye 4 is also taken up by ES2 ovarian carcinoma cells, where it is non-toxic under dark conditions. Upon irradiation of the ES2 cells at 694 nm, the brominated cyanine reduces cell viability from 100 ± 10% to 14 ± 1%. Our results suggest that 2-quinolinium-based carbocyanine dyes equipped with stabilizing electron withdrawing groups may have the potential to serve as sensitizing agents in long-wavelength phototherapeutic applications.

The impact of social support on adolescent coping in the context of urban poverty.

OBJECTIVE: This study used a mixed method, prospective, multi-informant design to (a) identify coping strategies used by youth residing in urban poverty and (b) test whether these coping strategies buffer the effects of stress exposure when adult support is present and when absent. METHOD: There were 286 youth ages 10 to 16 (mean age at Time 1 = 13; 65% female; 34% male; 1% not identified; 46% African American; 25% Latino; 11% European American; 8% Asian American, 4% Mixed/Biracial, 6% Other) and their parents who participated. Thematic analyses were used to code adolescent interviews about protective factors to identify specific coping strategies used. Hierarchical regression analyses tested whether these coping strategies moderate the association between stress exposure and psychological symptoms for youth with and without adult support. RESULTS: Youth identified multiple coping strategies as protective including Expressing Oneself, Self-Soothing, Seeking Help, Seeking Safety, Distraction, Problem-Solving, Self-Care, and Avoidance. A number of these coping strategies (Expressing Oneself, Self-Soothing, Seeking Help, and Seeking Safety) attenuated the association between stressors and psychological symptoms over time for youth with adult support. For youth without adult support, a number of the strategies they identified as protective (Distraction, Problem-Solving, and Self-Care) accentuated the association between stress exposure and psychological symptoms over time. The only strategy that proved protective for youth without adult support was avoidance. CONCLUSIONS: Findings suggest that youth require adult support to effectively make use of a range of coping strategies and that avoidance is the sole effective strategy for youth without support. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The Structure of the Barley Husk Influences Its Resistance to Mechanical Stress.

This paper explores the links between genotype, plant development, plant structure and plant material properties. The barley husk has two organs, the lemma and the palea, which protect the grain. When the husk is exposed to mechanical stress, such as during harvesting, it can be damaged or detached. This is known as grain skinning, which is detrimental to grain quality and has a significant economic impact on industry. This study focused on the lemma, the husk organ which is most susceptible to grain skinning. This study tested three hypotheses: (1) genotype and plant development determine lemma structure, (2) lemma structure influences the material properties of the lemma, and (3) the material properties of the lemma determine grain skinning risk. The effect of genotype was investigated by using plant material from four malting barley varieties: two with a high risk of grain skinning, two with a low risk. Plant material was assessed at two stages of plant development (anthesis, GS 65; grain filling, GS 77). Structure was assessed using light microscopy to measure three physiological features: thickness, vasculature and cell area. Material properties were approximated using a controlled impact assay and by analyzing fragmentation behavior. Genotype had a significant effect on lemma structure and material properties from anthesis. This indicates that differences between genotypes were established during floral development. The lemma was significantly thinner in high risk genotypes, compared to low risk genotypes. Consequently, in high risk genotypes, the lemma was significantly more likely to fragment. This indicates a relationship between reduced lemma thickness and increased fragmentation. Traditionally, a thin husk has been considered beneficial for malting quality, due to an association with malt extract. However, this study finds a thin lemma is less resistant to mechanical stress. This may explain the differences in grain skinning risk in the genotypes studied.

Single photon DNA photocleavage at 830 nm by quinoline dicarbocyanine dyes.

We have synthesized symmetrical carbocyanine dyes in which two 4-quinolinium rings are joined by a pentamethine bridge that is meso-substituted with H or Cl. Irradiation of the halogenated dye at 830 nm produces hydroxyl radicals that generate DNA direct strand breaks. This represents the first reported example of DNA photocleavage upon single photon excitation of a chromophore at wavelengths above 800 nm.

Environmental stress and socioeconomic status: Does parent and adolescent stress influence executive functioning in urban youth?

This study examined whether parental and adolescent stress act as mediators between socio-economic status (SES) and adolescent executive functioning (EF) in urban youth. Two hundred and sixty-seven 6th-11th grade students (ages 11-16, 55.4% female; 49.1% Black/African American) attending racially and socioeconomically diverse schools in Chicago, Illinois, completed self-report measures on urban stress and EF. Parents of adolescents completed measures on parental chronic stress and demographic information on the family's socioeconomic status. Results indicated that parent stress was directly related to adolescent stress, while adolescent stress was directly related to behavior components of EF (i.e., emotion control, set shifting, and inhibition). Although parental stress was related to adolescent's ability to shift from one task to another, no relationship was found with adolescent's ability to modulate mood or delay impulsive behaviors. Implications for socio-ecological mental health interventions for youth residing in urban environments are discussed.

Metal-Assisted Hydrolysis Reactions Involving Lipids: A Review.

This report covers major advances in the use of metal ions and complexes to hydrolyze ester and phosphate ester lipid bonds. These metal-based Lewis acids have been investigated as catalysts to isolate fatty acids from biological sources, as probes to study phospholipid bilayer properties, as tools to examine signal transduction pathways, and as lead compounds toward the discovery of therapeutic agents. Metal ions that accelerate phosphate ester hydrolysis under mild conditions of temperature and pH may have the potential to mimic phospholipase activity in biochemical applications.

Trauma Intervention in Sub-Saharan African Children: A Systematic Literature Review.

Sub-Saharan Africa is a part of the world that is highly affected by a large number of atrocities, causing a myriad of financial, physical health, and mental health consequences. Yet, unfortunately, according to the World Health Organization (WHO), this is also the part of the world that is least served by mental health services. In response, the WHO has created mandates to increase mental health resources and capacity in all countries. Researchers have taken on the work of introducing and adapting treatments in various sub-Saharan African countries with an aim to create sustainable, evidence-based treatment in a part of the world with high need. The current qualitative systematic review of the literature examines 20 articles that report on research conducted in sub-Saharan African countries with children who have suffered different types of traumas. This review answers questions concerning the types of treatments used, the people administering the treatments, the measures they take to adapt these treatments, and the types of outcomes that are seen. Overall, the majority of treatments being used are shown to be effective with the associated populations.

Taking on the stress-depression link: Meaning as a resource in adolescence.

We investigated how meaning in life affects the link between stress and depression symptoms in adolescents. Adolescents (N = 177; 58.4% female, mean age = 14.75 years) reported on their meaning in life, exposure to stressors, and depression symptomatology. Higher meaning in life predicted lower depression symptoms. Importantly, meaning in life moderated the relationship between stress exposure and depressive symptoms: stress exposure was associated with higher depression when meaning in life was low, when meaning in life was high, there was no association between stressors and depression. These findings indicate the importance of having a sense of meaning in life adolescence. A positive relationship was found between stress exposure and depression symptomatology levels at a time-point seven months earlier. This lends a longitudinal perspective; meaning in life moderated a relationship that had been present for seven months. Therapeutic implications for protecting at-risk youth are discussed.

Negative cognitive style and cortisol recovery accentuate the relationship between life stress and depressive symptoms.

When exposed to stressful life events, a significant number of adolescents will experience depressive symptoms. One model of depression suggests that individuals with a negative cognitive style are most vulnerable to depression following life stress. Alternatively, altered activation of the hypothalamic-pituitary-adrenal axis may explain vulnerability to depression following life stress. Each of these models plausibly explains the emergence of depressive symptoms during adolescence and have been investigated largely independently. The current study recruited a sample of urban adolescents (N = 179) to evaluate whether cortisol response to a laboratory stress induction and negative cognitive style are related and whether they independently interact with exposure to stressful life events to predict symptoms of depression. Negative cognitive style was not associated with cortisol response to the laboratory stressor. Rather, negative cognitive style and cortisol recovery independently interacted with stressful life events to predict current symptoms of depression. Results support a heterogeneous etiology of depression.

Exposure to Community Violence and the Trajectory of Internalizing and Externalizing Symptoms in a Sample of Low-Income Urban Youth.

This study examined trajectories of psychopathology in a sample of low-income urban youth and tested exposure to community violence as a predictor of these trajectories. Self-report and parent-report survey measures of psychological problems and exposure to community violence were collected annually over 3 years from a sample of 364 fifth- to ninth-grade low-income urban youth (64% female; 95% youth of color). Linear growth models showed that youth experienced declines in both internalizing and externalizing symptoms across adolescence. Exposure to community violence was more strongly associated with externalizing symptoms than with internalizing symptoms but predicted declines in both types of symptoms. Results also indicated that youth reported more internalizing and externalizing symptoms than their parents reported for them. Exposure to community violence may explain unique trajectories of mental health problems among low-income urban youth. In addition, youth efforts to adopt a tough façade in the face of community violence could lead to higher rates of externalizing problems relative to internalizing problems, whereas desensitization processes may better explain reductions in both types of symptoms over time. Finally, youth report may be more valid than parent report in the context of urban poverty.

Violence and Vigilance: The Acute Effects of Community Violent Crime on Sleep and Cortisol.

The data combine objectively measured sleep and thrice-daily salivary cortisol collected from a 4-day diary study in a large Midwestern city with location data on all violent crimes recorded during the same time period for N = 82 children (Mage  = 14.90, range = 11.27-18.11). The primary empirical strategy uses a within-person design to measure the change in sleep and cortisol from the person's typical pattern on the night/day immediately following a local violent crime. On the night following a violent crime, children have later bedtimes. Children also have disrupted cortisol patterns the following morning. Supplementary analyses using varying distances of the crime to the child's home address confirm more proximate crimes correspond to later bedtimes.

Adolescents' technology and face-to-face time use predict objective sleep outcomes.

OBJECTIVES: The present study examined both within- and between-person associations between adolescents' time use (technology-based activities and face-to-face interactions with friends and family) and sleep behaviors. We also assessed whether age moderated associations between adolescents' time use with friends and family and sleep. DESIGN: Adolescents wore an actigraph monitor and completed brief evening surveys daily for 3 consecutive days. PARTICIPANTS: Adolescents (N=71; mean age=14.50 years old, SD=1.84; 43.7% female) were recruited from 3 public high schools in the Midwest. MEASURES: We assessed 8 technology-based activities (eg, texting, working on a computer), as well as time spent engaged in face-to-face interactions with friends and family, via questions on adolescents' evening surveys. Actigraph monitors assessed 3 sleep behaviors: sleep latency, sleep hours, and sleep efficiency. RESULTS: Hierarchical linear models indicated that texting and working on the computer were associated with shorter sleep, whereas time spent talking on the phone predicted longer sleep. Time spent with friends predicted shorter sleep latencies, while family time predicted longer sleep latencies. Age moderated the association between time spent with friends and sleep efficiency, as well as between family time and sleep efficiency. Specifically, longer time spent interacting with friends was associated with higher sleep efficiency but only among younger adolescents. Furthermore, longer family time was associated with higher sleep efficiency but only for older adolescents. CONCLUSION: Findings are discussed in terms of the importance of regulating adolescents' technology use and improving opportunities for face-to-face interactions with friends, particularly for younger adolescents.

An unlikely DNA cleaving agent: A photo-active trinuclear Cu(II) complex based on hexaazatriphenylene.

This paper describes the synthesis of a trinuclear Cu(II) complex (4) containing a central 1,4,5,8,9,12-hexaazatriphenylene-hexacarboxylate (hat) core (3). Low, micromolar concentrations of the negatively charged parent ligand 3 and the neutral trinuclear complex 4 were found to photocleave negatively charged pUC19 plasmid DNA with high efficiency at neutral pH (350nm, 50min, 22°C). The interactions of complex 4 with double-helical DNA were studied in detail. Scavenger and colorimetric assays pointed to the formation of Cu(I), superoxide anion radicals, hydrogen peroxide, and hydroxyl radicals during photocleavage reactions. UV-visible absorption, circular dichroism, DNA thermal denaturation, and fluorescence data suggested that the Cu(II) complex contacts double-stranded DNA in an external fashion. The persistent association of ligand 3 and complex 4 with Na(I) and/or other cations in aqueous solution might facilitate electrostatic DNA interactions.

Real-time electrochemical LAMP: a rational comparative study of different DNA intercalating and non-intercalating redox probes.

We present a comparative study of ten redox-active probes for use in real-time electrochemical loop-mediated isothermal amplification (LAMP). Our main objectives were to establish the criteria that need to be fulfilled for minimizing some of the current limitations of the technique and to provide future guidelines in the search for ideal redox reporters. To ensure a reliable comparative study, each redox probe was tested under similar conditions using the same LAMP reaction and the same entirely automatized custom-made real-time electrochemical device (designed for electrochemically monitoring in real-time and in parallel up to 48 LAMP samples). Electrochemical melt curve analyses were recorded immediately at the end of each LAMP reaction. Our results show that there are a number of intercalating and non-intercalating redox compounds suitable for real-time electrochemical LAMP and that the best candidates are those able to intercalate strongly into ds-DNA but not too much to avoid inhibition of the LAMP reaction. The strongest intercalating redox probes were finally shown to provide higher LAMP sensitivity, speed, greater signal amplitude, and cleaner-cut DNA melting curves than the non-intercalating molecules.

The Costs and Benefits of Active Coping for Adolescents Residing in Urban Poverty.

The present study addresses the lack of specificity and diversity highlighted in recent stress literature reviews by examining active coping in relationships between exposure to violence and internalizing and externalizing symptoms in a sample of urban youth from predominantly low-income, African American and Latino backgrounds. Two hundred and forty-one youth (mean age at Time 1 = 13 years; 66 % female; 41 % African American, 28 % Latino, 14 % European American, 6 % Asian American, 7 % mixed/biracial, 1 % American Indian/native American, .5 % Hawaiian/Pacific Islander, 2 % other) and their parents participated in this three-wave study. Hierarchical regression analyses tested for moderation, and a cross lag panel path analysis tested for mediation. The results provide greater support for active coping as a variable that changes the relationship between exposure to community violence and externalizing symptoms, or moderation, rather than one that explains or mediates it. Further, specificity did not emerge for type of psychological outcome but did emerge for gender, such that active coping exacerbated the association between exposure to community violence and both internalizing and externalizing symptoms for girls, but not boys. These findings highlight the importance of contextual and demographic factors in influencing stress and coping processes during adolescence.

Development of an Empirically Based Preventive Intervention for Depression in Preadolescent African American Girls.

We describe the development, feasibility, and acceptability of a novel preventive intervention for depression in African American girls living in urban poverty. Our approach targeted individual and interpersonal vulnerabilities that have been shown to confer risk for depression in samples of African American girls living in low-income, urban settings, including suppression of negative emotion and lack of assertiveness with peers, memory for positive emotion, active coping, and family connection. Focus groups and an open trial were conducted to refine the goals and mechanisms for skill building. A randomized controlled trial (RCT) of the new program (Cities Mother-Daughter Project) was conducted with 3rd-5th grade students from Chicago Public Schools (CPS). Three cycles of screening, randomization, and deployment were conducted to assess feasibility, satisfaction, and usability. Results indicate that feasibility was weak; whereas, satisfaction and usability were high. Future directions for testing efficacy are discussed.