Search

The goal of the current study was to examine the protective role that maternal media monitoring might have for adolescents. This was done by considering whether styles of media monitoring either directly reduced media use, or whether they buffered the associations between aggressive media use and adolescents' prosocial behavior, aggression, and delinquency. Participants were 681 adolescents from two cities in the United States (51% female; 73% white), and their mothers, who provided data at two different time points, 2 years apart (when adolescents were roughly ages 13 and 15). Mixture modeling results revealed that mothers used four different styles of media monitoring made up of combinations of active and restrictive monitoring as well as forms of co-use. Styles that included active monitoring and connective co-use (i.e., engaging in media with the intent to connect with children) were directly associated with less media use, and moderated links between adolescents' media use and behavioral outcomes concurrently but not longitudinally. The discussion was focused on the strength of considering multiple strategies of media monitoring together, and how this approach can inform future research in the area of parental media monitoring.

This study examined growth trajectories of texting (and other media) over a 6-year time period. Participants were 425 adolescents from Washington, USA (age 13 at Time 1, age 18 at Time 6; 48% male, 68% European American). Analyses suggested a curvilinear pattern for texting and social media use, with rates peaking during midadolescence. There was also considerable heterogeneity in trajectories of texting. A growth mixture model revealed four distinct classes of individuals: perpetuals (14%), decreasers (7%), moderates (68%), and increasers (11%). Higher levels of depression, being a male, and coming from a single-parent family predicted being a "perpetual" texter. Perpetuals had the most problematic outcomes compared to other classes, including higher depression, anxiety, aggression, and poor relationships with fathers., (© 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.)

Zika virus (ZIKV) shares a high degree of homology with dengue virus (DENV), suggesting that preexisting immunity to DENV could affect immune responses to ZIKV. We have tracked the evolution of ZIKV-induced B cell responses in three DENV-experienced donors. The acute antibody (plasmablast) responses were characterized by relatively high somatic hypermutation and a bias toward DENV binding and neutralization, implying the early activation of DENV clones. A DENV-naïve donor in contrast showed a classical primary plasmablast response. Five months after infection, the DENV-experienced donors developed potent type-specific ZIKV neutralizing antibody responses in addition to DENV cross-reactive responses. Because cross-reactive responses were poorly neutralizing and associated with enhanced ZIKV infection in vitro, preexisting DENV immunity could negatively affect protective antibody responses to ZIKV. The observed effects are epitope-dependent, suggesting that a ZIKV vaccine should be carefully designed for DENV-seropositive populations., (Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

The present study examined age-trends and longitudinal bidirectional relations in self-esteem and prosocial behavior toward strangers, friends, and family over a four-year time period (age 11 to 14). A total of 681 adolescents were recruited in the United States (51% girls, 28% single parent families). A longitudinal panel model was conducted and the results showed that adolescent self-esteem was associated longitudinally with subsequent prosocial behavior toward strangers, and earlier prosocial behavior toward strangers promoted subsequent self-esteem. There were no such bidirectional relations between self-esteem and prosocial behavior toward friends and family. Findings also highlight the complexity of adolescent development of selfesteem and the multidimensional nature of prosocial behavior. Discussion focuses on understanding the dynamic interplay between adolescent selfesteem and prosocial behavior., (Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.)

Respiratory syncytial virus (RSV) causes substantial morbidity and mortality in young children and the elderly. There are currently no licensed RSV vaccines, and passive prophylaxis with the monoclonal antibody palivizumab is restricted to high-risk infants in part due to its modest efficacy. Although it is widely agreed that an effective RSV vaccine will require the induction of a potent neutralizing antibody response against the RSV fusion (F) glycoprotein, little is known about the specificities and functional activities of RSV F-specific antibodies induced by natural infection. Here, we have comprehensively profiled the human antibody response to RSV F by isolating and characterizing 364 RSV F-specific monoclonal antibodies from the memory B cells of three healthy adult donors. In all donors, the antibody response to RSV F is comprised of a broad diversity of clones that target several antigenic sites. Nearly half of the most potent antibodies target a previously undefined site of vulnerability near the apex of the prefusion conformation of RSV F (preF), providing strong support for the development of RSV vaccine candidates that preserve the membrane-distal hemisphere of the preF protein. Additionally, the antibodies targeting this new site display convergent sequence features, thus providing a future means to rapidly detect the presence of these antibodies in human vaccine samples. Many of the antibodies that bind preF-specific surfaces are over 100 times more potent than palivizumab, and several cross-neutralize human metapneumovirus (HMPV). Taken together, the results have implications for the design and evaluation of RSV vaccine candidates and offer new options for passive prophylaxis.

Species identification in the myxomycetes (plasmodial slime molds or myxogastrids) poses particular challenges to researchers as a result of their morphological plasticity and frequent alteration between sexual and asexual life strategies. Traditionally, myxomycete morphology has been used as the primary method of species delimitation. However, with the increasing availability of genetic information, traditional myxomycete taxonomy is being increasingly challenged, and new hypotheses continue to emerge. Due to conflicts that sometimes occur between traditional and more modern species concepts that are based largely on molecular data, there is a pressing need to revisit the discussion surrounding the species concept used for myxomycetes. Biological diversity is being increasingly studied with molecular methods and data accumulates at ever-faster rates, making resolution of this matter urgent. In this review, currently used and potentially useful species concepts (biological, morphological, phylogenetic and ecological) are reviewed, and an integrated approach to resolve the myxomycete species problem is discussed., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

The current study examined the influence that parental warmth/support and verbal hostility had on adolescents' prosocial behavior toward multiple targets (stranger, friend, family) using multiple reporters (self, parent, observations). Data were taken from Times 2 and 3 of a longitudinal project and included 500 adolescents and their parents (M age of child at Time 2 = 12.34). Structural equation models suggested that mother warmth was associated with prosocial behavior toward family, while father warmth was associated with prosocial behavior toward friends. Findings also suggested that adolescents' prosocial behavior was more consistently influenced by father hostility than it was by father warmth. Finally, observational reports of father hostility were associated with adolescent prosocial behavior more consistently than self- or child-reported parenting. The discussion focuses on the importance of considering target of prosocial behavior, the differences between mothers and fathers, and the role of self-reports compared to observations., ((c) 2016 APA, all rights reserved).)

Antibodies targeting the Ebola virus surface glycoprotein (EBOV GP) are implicated in protection against lethal disease, but the characteristics of the human antibody response to EBOV GP remain poorly understood. We isolated and characterized 349 GP-specific monoclonal antibodies (mAbs) from the peripheral B cells of a convalescent donor who survived the 2014 EBOV Zaire outbreak. Remarkably, 77% of the mAbs neutralize live EBOV, and several mAbs exhibit unprecedented potency. Structures of selected mAbs in complex with GP reveal a site of vulnerability located in the GP stalk region proximal to the viral membrane. Neutralizing antibodies targeting this site show potent therapeutic efficacy against lethal EBOV challenge in mice. The results provide a framework for the design of new EBOV vaccine candidates and immunotherapies., (Copyright © 2016, American Association for the Advancement of Science.)

The current study examined bidirectional, longitudinal links between prosocial and problem behavior. Participants (N = 500) were recruited from a Northwestern city in the United States and assessed for 3 consecutive years from 2009 to 2011 (M(age) of youth at Time 1 = 13.32, SD = 1.05; 52% girls; 67% European American, 33% single-parent families). Results suggested that effects of earlier prosocial behavior toward family and strangers were predictive of fewer problem behaviors 2 years later, while results for prosocial behavior toward friends were more mixed. Results also suggested depression predicted lower prosocial behavior toward family members and anxiety predicted higher prosocial behavior toward friends. Findings show a complex pattern of relations that demonstrate the need to consider targets of helping., (© 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.)

Siblings play an important role in relational and individual development throughout adolescence and beyond through several mechanisms. Central to this role and the mechanisms of sibling influence is the notion that siblings provide a constant and meaningful frame of reference for social comparison. This study examined the role of sibling social comparison orientation, or the tendency of siblings to compare themselves to one another, on youths' depressive symptoms and family relationships, both directly and by moderating links with parental differential treatment. Participants included 338 youth (M age = 18.34, SD = 1.03; 52 % female). Using hierarchical ordinary least squares regression, we found that a higher sibling social comparison orientation was linked with more depressive symptoms, warmer sibling relationships, and more sibling conflict. Additionally, sibling social comparison orientation moderated links of parental differential treatment with depressive symptoms and prosocial behavior toward family members such that effects were more salient for those with a high comparison orientation. The discussion focuses on the role of sibling comparison in the ways that siblings influence one another's development.

The current study examined longitudinal cross-lagged associations between prosocial TV (content and time) and prosocial and aggressive behavior during adolescence, and explored the mediating role of empathic concern and self-regulation. Participants were 441 adolescents who reported on their 3 favorite TV shows at 2 time points, approximately 2 years apart (M age of child at Time 3 = 13.31, SD = 1.06; 52% female; M age of child at Time 5 = 15.27, SD = 1.06). Results suggested that prosocial content at Time 3 was negatively associated with aggressive behavior 2 years later, and aggressive behavior at Time 3 was positively associated with aggressive content 2 years later. Results also suggested that prosocial behavior toward strangers at Time 3 was associated with both empathic concern and self-regulation at Time 4, which were in turn associated with prosocial and aggressive content at Time 5. Discussion focuses on the important role of behavior and prosocial personality on media selection during adolescence and the relevance of the target of prosocial behavior., ((c) 2015 APA, all rights reserved).)

A new species of myxomycete, Perichaena longipes, is described from 56 sporocarp specimens that appeared in moist chamber cultures prepared with samples of decaying plant materials collected in Panama, Costa Rica and Brazil. This new species is distinguished from the morphologically similar species P. pedata on the basis of the much longer stipe, lighter peridium and the unique ornamentation of the capillitium. The nuc 18S ribosomal DNA sequences obtained from four specimens of P. longipes support the distinction of this new taxon and its separation from P. pedata. Furthermore, maximum likelihood phylogeny supports earlier evidence that species currently within the genus Perichaena do not form a monophyletic clade. Instead they appear to form three separate branches within the bright-spored clade. The first clade includes P. longipes together with several species of Trichia and Metatrichia, the second includes P. pedata and P. chrysosperma, and the third clade is composed of P. corticalis, P. depressa and P. luteola., (© 2015 by The Mycological Society of America.)

Four hundred Danish emerging adults ages 17-29 were surveyed regarding their conceptions of adulthood and their self-assessments of their adult status. A majority of the 17-24-year-olds and nearly half the 25-29-year-olds viewed themselves as being adults in some ways but not others. Participants reported feeling most adult when with co-workers or romantic partners, and least adult with mothers, fathers, or friends. The most widely-endorsed criteria for adulthood were accepting responsibility for one's self, making independent decisions, and becoming financially independent. Among the least-endorsed criteria were the traditional transition events of entering marriage and parenthood, as well as "avoid becoming drunk.", (Copyright © 2014 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.)

Despite numerous attempts over many years to develop an HIV vaccine based on classical strategies, none has convincingly succeeded to date. A number of approaches are being pursued in the field, including building upon possible efficacy indicated by the recent RV144 clinical trial, which combined two HIV vaccines. Here, we argue for an approach based, in part, on understanding the HIV envelope spike and its interaction with broadly neutralizing antibodies (bnAbs) at the molecular level and using this understanding to design immunogens as possible vaccines. BnAbs can protect against virus challenge in animal models, and many such antibodies have been isolated recently. We further propose that studies focused on how best to provide T cell help to B cells that produce bnAbs are crucial for optimal immunization strategies. The synthesis of rational immunogen design and immunization strategies, together with iterative improvements, offers great promise for advancing toward an HIV vaccine., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Variable regions 1 and 2 (V1/V2) of human immunodeficiency virus-1 (HIV-1) gp120 envelope glycoprotein are critical for viral evasion of antibody neutralization, and are themselves protected by extraordinary sequence diversity and N-linked glycosylation. Human antibodies such as PG9 nonetheless engage V1/V2 and neutralize 80% of HIV-1 isolates. Here we report the structure of V1/V2 in complex with PG9. V1/V2 forms a four-stranded β-sheet domain, in which sequence diversity and glycosylation are largely segregated to strand-connecting loops. PG9 recognition involves electrostatic, sequence-independent and glycan interactions: the latter account for over half the interactive surface but are of sufficiently weak affinity to avoid autoreactivity. The structures of V1/V2-directed antibodies CH04 and PGT145 indicate that they share a common mode of glycan penetration by extended anionic loops. In addition to structurally defining V1/V2, the results thus identify a paradigm of antibody recognition for highly glycosylated antigens, which-with PG9-involves a site of vulnerability comprising just two glycans and a strand.

Broadly neutralizing antibodies against highly variable viral pathogens are much sought after to treat or protect against global circulating viruses. Here we probed the neutralizing antibody repertoires of four human immunodeficiency virus (HIV)-infected donors with remarkably broad and potent neutralizing responses and rescued 17 new monoclonal antibodies that neutralize broadly across clades. Many of the new monoclonal antibodies are almost tenfold more potent than the recently described PG9, PG16 and VRC01 broadly neutralizing monoclonal antibodies and 100-fold more potent than the original prototype HIV broadly neutralizing monoclonal antibodies. The monoclonal antibodies largely recapitulate the neutralization breadth found in the corresponding donor serum and many recognize novel epitopes on envelope (Env) glycoprotein gp120, illuminating new targets for vaccine design. Analysis of neutralization by the full complement of anti-HIV broadly neutralizing monoclonal antibodies now available reveals that certain combinations of antibodies should offer markedly more favourable coverage of the enormous diversity of global circulating viruses than others and these combinations might be sought in active or passive immunization regimes. Overall, the isolation of multiple HIV broadly neutralizing monoclonal antibodies from several donors that, in aggregate, provide broad coverage at low concentrations is a highly positive indicator for the eventual design of an effective antibody-based HIV vaccine., (© 2011 Macmillan Publishers Limited. All rights reserved)

Purpose: Video game use has been associated with several behavioral and health outcomes for adolescents. The aim of the current study was to assess the relationship between parental co-play of video games and behavioral and family outcomes., Method: Participants consisted of 287 adolescents and their parents who completed a number of video game-, behavioral-, and family-related questionnaires as part of a wider study. Most constructs included child, mother, and father reports., Results: At the bivariate level, time spent playing video games was associated with several negative outcomes, including heightened internalizing and aggressive behavior and lowered prosocial behavior. However, co-playing video games with parents was associated with decreased levels of internalizing and aggressive behaviors, and heightened prosocial behavior for girls only. Co-playing video games was also marginally related to parent-child connectedness for girls, even after controlling for age-inappropriate games played with parents., Conclusions: This is the first study to show positive associations for co-playing video games between girls and their parents., (Copyright © 2011 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

The current study examined the role of adolescents' self-regulation as a mediator between sibling relationship quality and adolescent outcomes, after controlling for the quality of the parent-child relationship. Participants were 395 families (282 two parent; 113 single parent) with an adolescent child (M age of child at Time 1 = 11.15, SD = .96, 49% female) who took part in [project name masked for blind review] at both Time 1 and Time 2. Path analysis via structural equation modeling suggested that sibling affection was longitudinally and positively related to self-regulation and prosocial behaviors, and negatively related to externalizing behaviors; while sibling hostility was positively, and having a sister was negatively related to internalizing behaviors (in general, paths were stronger for adolescents from two- vs. single-parent families). There was also evidence that adolescents' self-regulation partially mediated the relation between sibling affection and positive and negative adolescent outcomes. The discussion focuses on the importance of continued research examining the mechanisms through which the sibling relationship influences development during adolescence.

Development of an effective vaccine against HIV-1 will likely require elicitation of broad and potent neutralizing antibodies against the trimeric surface envelope glycoprotein (Env). Monoclonal antibodies (mAbs) PG9 and PG16 neutralize approximately 80% of HIV-1 isolates across all clades with extraordinary potency and target novel epitopes preferentially expressed on Env trimers. As these neutralization properties are ideal for a vaccine-elicited antibody response to HIV-1, their structural basis was investigated. The crystal structure of the antigen-binding fragment (Fab) of PG16 at 2.5 A resolution revealed its unusually long, 28-residue, complementarity determining region (CDR) H3 forms a unique, stable subdomain that towers above the antibody surface. A 7-residue "specificity loop" on the "hammerhead" subdomain was identified that, when transplanted from PG16 to PG9 and vice versa, accounted for differences in the fine specificity and neutralization of these two mAbs. The PG16 electron density maps also revealed that a CDR H3 tyrosine was sulfated, which was confirmed for both PG9 (doubly) and PG16 (singly) by mass spectral analysis. We further showed that tyrosine sulfation plays a role in binding and neutralization. An N-linked glycan modification is observed in the variable light chain, but not required for antigen recognition. Further, the crystal structure of the PG9 light chain at 3.0 A facilitated homology modeling to support the presence of these unusual features in PG9. Thus, PG9 and PG16 use unique structural features to mediate potent neutralization of HIV-1 that may be of utility in antibody engineering and for high-affinity recognition of a variety of therapeutic targets.

Many antiviral vaccines elicit neutralizing antibodies as a correlate of protection. For HIV, given the huge variability of the virus, it is widely believed that the induction of a broadly neutralizing antibody (bNAb) response will be crucial in a successful vaccine against the virus. Unfortunately, despite many efforts, the development of an immunogen that elicits bNAbs remains elusive. However, recent structural studies of HIV-1 Env proteins, generation of novel bNAbs, maturation of technologies for the isolation of further antibodies, insights into the requirements for antibody-mediated protection, and novel vaccination approaches are providing grounds for renewed optimism., (Copyright 2010 Elsevier Ltd. All rights reserved.)

The purpose of the current study was to explore how mother's and father's connectedness and involvement individually and collectively influence the lives of their children. Specifically, we asked how fathers' and mothers' parent-child connectedness and behavioral involvement influenced both problem behaviors (externalizing and internalizing behaviors) and positive outcomes (prosocial behaviors and hope) during early adolescence. Data for this study were taken from the Flourishing Families Project, from which 349 mothers and fathers were selected, along with their early adolescent child (mean age = 11.23 years, SD = .96). Hierarchical regression analyses revealed (even after controlling for child age, gender, and self-regulation) that mothers' and fathers' contributions differed, primarily as a function of child outcome. Namely, father (but not mother) connectedness and involvement were negatively related to adolescents' internalizing and externalizing behaviors, whereas mother (but not father) connectedness and involvement were positively related to adolescents' prosocial behaviors and hope. We also found that when one parent's involvement was low (for whatever reason), the other parent's involvement made a significant and important contribution to the child's well-being, particularly in the area of internalizing behaviors.

Broadly neutralizing antibodies (bNAbs), which develop over time in some HIV-1-infected individuals, define critical epitopes for HIV vaccine design. Using a systematic approach, we have examined neutralization breadth in the sera of about 1800 HIV-1-infected individuals, primarily infected with non-clade B viruses, and have selected donors for monoclonal antibody (mAb) generation. We then used a high-throughput neutralization screen of antibody-containing culture supernatants from about 30,000 activated memory B cells from a clade A-infected African donor to isolate two potent mAbs that target a broadly neutralizing epitope. This epitope is preferentially expressed on trimeric Envelope protein and spans conserved regions of variable loops of the gp120 subunit. The results provide a framework for the design of new vaccine candidates for the elicitation of bNAb responses.

Yeast display is a powerful technology for the isolation of monoclonal antibodies (mAbs) against a target antigen. Antibody libraries have been displayed on the surface of yeast as both single-chain variable fragment (scFv) and antigen binding fragment (Fab). Here, we combine these two formats to display well-characterized mAbs as single-chain Fabs (scFabs) on the surface of yeast and construct the first scFab yeast display antibody library. When expressed on the surface of yeast, two out of three anti-human immunodeficiency virus (HIV)-1 mAbs bound with higher affinity as scFabs than scFvs. Also, the soluble scFab preparations exhibited binding and neutralization profiles comparable to that of the corresponding Fab fragments. Display of an immune HIV-1 scFab library on the surface of yeast, followed by rounds of sorting against HIV-1 gp120, allowed for the selection of 13 antigen-specific clones. When the same cDNA was used to construct the library in an scFv format, a similar number but a lower affinity set of clones were selected. Based on these results, yeast-displayed scFab libraries can be constructed and selected with high efficiency, characterized without the need for a reformatting step, and used to isolate higher-affinity antibodies than scFv libraries.

The Mre11-Rad50-Nbs1 (MRN) complex functions in the repair of DNA double-strand breaks (DSBs) by homologous recombination (HR) at postreplicative stages of the cell cycle. During HR, the MRN complex functions directly in the repair of DNA DSBs and in the initiation of DSB responses through activation of the ataxia telangiectasia-mutated (ATM) serine-threonine kinase. Whether MRN functions in DNA damage responses before DNA replication in G0/G1 phase cells has been less clear. In developing G1-phase lymphocytes, DNA DSBs are generated by the Rag endonuclease and repaired during the assembly of antigen receptor genes by the process of V(D)J recombination. Mice and humans deficient in MRN function exhibit lymphoid phenotypes that are suggestive of defects in V(D)J recombination. We show that during V(D)J recombination, MRN deficiency leads to the aberrant joining of Rag DSBs and to the accumulation of unrepaired coding ends, thus establishing a functional role for MRN in the repair of Rag-mediated DNA DSBs. Moreover, these defects in V(D)J recombination are remarkably similar to those observed in ATM-deficient lymphocytes, suggesting that ATM and MRN function in the same DNA DSB response pathways during lymphocyte antigen receptor gene assembly.

The purpose of the current study was to examine adolescents' perceptions of the appropriateness of maternal discipline across social domains and how domain-appropriateness was related to adolescents' prosocial and antisocial behaviors via adolescents' personal prosocial values. A total of 133 adolescents (54% girls; mean age = 16.23 years, SD = 1.27) completed questionnaires in their classrooms at school. Results suggest that adolescents perceived mothers as responding differently to their misbehavior and perceived different maternal discipline as appropriate as a function of the domain into which the misbehavior fit. Findings also suggest that domain-appropriateness of maternal discipline was related to adolescent outcomes (directly, and indirectly via personal values), suggesting the importance of domain-appropriate maternal discipline during adolescence.