Taking the good with the bad?: Social Media and Online Racial Discrimination Influences on Psychological and Academic Functioning in Black and Hispanic Youth.

Though increasing attention is being paid to adolescents' social media use, racially/ethnically-marginalized youth remain under-represented in that literature, and the effect of social media and its mechanism on these youth remain unclear. This study examined the effects of social media use on Black and Hispanic youth's psychological and academic functioning, with an attempt to investigate the role of online racial discrimination in accounting for these associations. Participants consisted of 356 Black and Hispanic youth (Mage = 16.01 years, SD = 1.60), and 78% female. The findings revealed a positive association between social media use and academic self-efficacy. A negative indirect association also emerged where social media use was associated with more exposure to vicarious, but not individual, online racial discrimination, which was related to more depressive symptoms and in turn lower academic self-efficacy. There was no direct effect of social media use on Black and Hispanic youth's anxiety symptoms, but its effect occurred indirectly via both individual and vicarious online racial discrimination. There was no evidence of group differences between Black and Hispanic youth. The findings confirm that social media is a space that proffers positive and negative effects on adolescents' psychological and academic functioning, suggesting the need for unique protections for racially/ethnically marginalized youth as they explore these online environments.

Purpose Trajectories During Middle Adolescence: The Roles of Family, Teacher, and Peer Support.

While studies on youth's purpose have flourished in the last two decades, the work was mostly cross-sectional and derived from Western settings. This research examined the developmental trajectories of purpose exploration and commitment of Taiwanese youth during middle adolescence, with a focus on how they associate with youth's psychological functioning in terms of life satisfaction and depressive symptoms and whether social support moderates such development. A total of 369 vocational high school students in Taiwan (45% females; Mage = 15.82 years) participated in a four-wave study spanning two years with a one-semester interval. The results of piecewise growth curve modeling in the context of structural equation modeling suggested that purpose commitment increased over 10th grade, decreased initially in 11th grade, and then continued to increase. Purpose exploration similarly increased over 10th grade, but after the initial 11th grade dip remained stable. In addition to the higher initial levels, the steeper the rate of purpose exploration and commitment ascent and the slighter the rate of reduction predicted enhanced youth life satisfaction. The trajectory of purpose commitment also predicted reduced depressive symptoms, but such effects did not occur for purpose exploration. Moreover, multi-group analyses revealed that the more family, teacher, and peer support youth perceived, the more likely youth explored and committed to purpose over time.

Why is Self-Esteem Higher Among American than Chinese Early Adolescents? The Role of Psychologically Controlling Parenting.

Little is known about why American youth tend to have higher self-esteem than do Chinese youth. This research examined the role of psychologically controlling parenting during early adolescence. 825 youth (48% females; Mage = 12.73 years) in the United States and China reported on their self-esteem and parents' psychological control every 6 months from the fall of 7th grade to spring of 8th grade. Both American and Chinese youth's self-esteem decreased over time, but American youth consistently had higher self-esteem. American parents were less psychologically controlling than were Chinese parents who, unlike American parents, became more psychologically controlling over time. These differences in psychologically controlling parenting contributed to the tendency for American youth to have higher self-esteem than their Chinese counterparts.

Developmental trajectory of purpose identification during adolescence: Links to life satisfaction and depressive symptoms.

INTRODUCTION: Whereas evidence has shown that a sense of purpose is linked to optimal adjustment, longitudinal work investigating the development of purpose identification as well as its effect on psychological functioning among non-Western samples during adolescence is needed. METHODS: Three hundred and eighty-seven senior high school students (253 female, 65.37%; mean age = 15.76 years at the first investigation) from Taiwan completed surveys four times beginning in the fall of tenth grade and ending in the spring of eleventh grade with a six-month interval. Using self-ratings, purpose identification was evaluated in all four assessments and psychological functioning was examined through life satisfaction and depressive symptoms in the first and the last survey. RESULTS: Growth curve analyses revealed an increased slope in purpose identification over the first two years of high school, and such a trajectory was similar across boys and girls. Additionally, increases in purpose identification predicted enhanced life satisfaction and reduced depressive symptoms among both boys and girls. There was only one gender difference: The negative association between purpose identification trajectory and depressive symptoms was stronger for girls than for boys. CONCLUSIONS: There is an increase in the development of identified purpose during middle adolescence among high school students in Taiwan. Such change not only promotes life satisfaction in adolescents but is also preventive of adolescent depression. As such, the current findings highlight the significance for adolescents to discover and commit to a purpose.

Non-fullerene electron acceptors for use in organic solar cells.

The active layer in a solution processed organic photovoltaic device comprises a light absorbing electron donor semiconductor, typically a polymer, and an electron accepting fullerene acceptor. Although there has been huge effort targeted to optimize the absorbing, energetic, and transport properties of the donor material, fullerenes remain as the exclusive electron acceptor in all high performance devices. Very recently, some new non-fullerene acceptors have been demonstrated to outperform fullerenes in comparative devices. This Account describes this progress, discussing molecular design considerations and the structure-property relationships that are emerging. The motivation to replace fullerene acceptors stems from their synthetic inflexibility, leading to constraints in manipulating frontier energy levels, as well as poor absorption in the solar spectrum range, and an inherent tendency to undergo postfabrication crystallization, resulting in device instability. New acceptors have to address these limitations, providing tunable absorption with high extinction coefficients, thus contributing to device photocurrent. The ability to vary and optimize the lowest unoccupied molecular orbital (LUMO) energy level for a specific donor polymer is also an important requirement, ensuring minimal energy loss on electron transfer and as high an internal voltage as possible. Initially perylene diimide acceptors were evaluated as promising acceptor materials. These electron deficient aromatic molecules can exhibit good electron transport, facilitated by close packed herringbone crystal motifs, and their energy levels can be synthetically tuned. The principal drawback of this class of materials, their tendency to crystallize on too large a length scale for an optimal heterojunction nanostructure, has been shown to be overcome through introduction of conformation twisting through steric effects. This has been primarily achieved by coupling two units together, forming dimers with a large intramolecular twist, which suppresses both nucleation and crystal growth. The generic design concept of rotationally symmetrical aromatic small molecules with extended π orbital delocalization, including polyaromatic hydrocarbons, phthalocyanines, etc., has also provided some excellent small molecule acceptors. In most cases, additional electron withdrawing functionality, such as imide or ester groups, can be incorporated to stabilize the LUMO and improve properties. New calamitic acceptors have been developed, where molecular orbital hybridization of electron rich and poor segments can be judiciously employed to precisely control energy levels. Conformation and intermolecular associations can be controlled by peripheral functionalization leading to optimization of crystallization length scales. In particular, the use of rhodanine end groups, coupled electronically through short bridged aromatic chains, has been a successful strategy, with promising device efficiencies attributed to high lying LUMO energy levels and subsequently large open circuit voltages.

Topological Distribution of Wound Stiffness Modulates Wound-Induced Hair Follicle Neogenesis.

In the large full-thickness mouse skin regeneration model, wound-induced hair neogenesis (WIHN) occurs in the wound center. This implies a spatial regulation of hair regeneration. The role of mechanotransduction during tissue regeneration is poorly understood. Here, we created wounds with equal area but different shapes to understand if perturbing mechanical forces change the area and quantity of de novo hair regeneration. Atomic force microscopy of wound stiffness demonstrated a stiffness gradient across the wound with the wound center softer than the margin. Reducing mechanotransduction signals using FAK or myosin II inhibitors significantly increased WIHN and, conversely, enhancing these signals with an actin stabilizer reduced WIHN. Here, α-SMA was downregulated in FAK inhibitor-treated wounds and lowered wound stiffness. Wound center epithelial cells exhibited a spherical morphology relative to wound margin cells. Differential gene expression analysis of FAK inhibitor-treated wound RNAseq data showed that cytoskeleton-, integrin-, and matrix-associated genes were downregulated, while hair follicular neogenesis, cell proliferation, and cell signaling genes were upregulated. Immunohistochemistry staining showed that FAK inhibition increased pSTAT3 nuclear staining in the regenerative wound center, implying enhanced signaling for hair follicular neogenesis. These findings suggest that controlling wound stiffness modulates tissue regeneration encompassing epithelial competence, tissue patterning, and regeneration during wound healing.

Parental Psychological Control and Children's Relational Aggression: Examining the Roles of Gender and Normative Beliefs about Relational Aggression.

Drawing on the information processing model for the development of aggression, children's acquisition of aggressive responses could be associated with parenting that communicated norms favoring aggression. Extending this view, the present study examined the mediating role of children's normative beliefs about relational aggression (NBRA) on the association between psychologically controlling parenting and children's relational aggression (RA), and further explored whether this possible indirect effect would be contingent on the child's gender. 341 upper elementary school students (174 boys and 166 girls) reported perceived paternal psychological control (PPC) and maternal psychological control (MPC) during their fifth-grade fall semester, rated their NBRA during their sixth-grade fall semester, and assessed RA through a peer-nomination procedure during their sixth-grade spring semester. Results demonstrated that the indirect effects of perceived PPC and MPC on children's RA via their NBRA were both significant among the entire sample. However, by means of conditional process analysis, we found that whereas perceived PPC positively predicted boys' and girls' NBRA, perceived MPC positively predicted boys' but not girls' NBRA. In addition, children's NBRA was only positively predictive of RA for girls. As such, the indirect effect was exclusively significant for perceived PPC among girls.

Fused electron deficient semiconducting polymers for air stable electron transport.

Conventional semiconducting polymer synthesis typically involves transition metal-mediated coupling reactions that link aromatic units with single bonds along the backbone. Rotation around these bonds contributes to conformational and energetic disorder and therefore potentially limits charge delocalisation, whereas the use of transition metals presents difficulties for sustainability and application in biological environments. Here we show that a simple aldol condensation reaction can prepare polymers where double bonds lock-in a rigid backbone conformation, thus eliminating free rotation along the conjugated backbone. This polymerisation route requires neither organometallic monomers nor transition metal catalysts and offers a reliable design strategy to facilitate delocalisation of frontier molecular orbitals, elimination of energetic disorder arising from rotational torsion and allowing closer interchain electronic coupling. These characteristics are desirable for high charge carrier mobilities. Our polymers with a high electron affinity display long wavelength NIR absorption with air stable electron transport in solution processed organic thin film transistors.

Tuning the effective spin-orbit coupling in molecular semiconductors.

The control of spins and spin to charge conversion in organics requires understanding the molecular spin-orbit coupling (SOC), and a means to tune its strength. However, quantifying SOC strengths indirectly through spin relaxation effects has proven difficult due to competing relaxation mechanisms. Here we present a systematic study of the g-tensor shift in molecular semiconductors and link it directly to the SOC strength in a series of high-mobility molecular semiconductors with strong potential for future devices. The results demonstrate a rich variability of the molecular g-shifts with the effective SOC, depending on subtle aspects of molecular composition and structure. We correlate the above g-shifts to spin-lattice relaxation times over four orders of magnitude, from 200 to 0.15 µs, for isolated molecules in solution and relate our findings for isolated molecules in solution to the spin relaxation mechanisms that are likely to be relevant in solid state systems.

A thieno[3,2-b][1]benzothiophene isoindigo building block for additive- and annealing-free high-performance polymer solar cells.

A novel photoactive polymer with two different molecular weights is reported, based on a new building block: thieno[3,2-b][1]benzothiophene isoindigo. Due to the improved crystallinity, optimal blend morphology, and higher charge mobility, solar-cell devices of the high-molecular-weight polymer exhibit a superior performance, affording efficiencies of 9.1% without the need for additives, annealing, or additional extraction layers during device fabrication.

Rare solvent annealing effective benzo(1,2-b:4,5-b')dithiophene-based low band-gap polymer for bulk heterojunction organic photovoltaics.

A newly synthesized benzo(1,2-b:4,5-b')dithiophene-based low band-gap copolymer pBCN is amenable to solvent annealing in the fabrication of organic photovoltaics, of which power conversion efficiency is greatly improved to 4.2% with PC(61)BM or 4.9% with PC(71)BM.