The Increasing Rotation Period of Comet 10P/Tempel 2

We imaged comet 10P/Tempel 2 on 32 nights from 1999 April through 2000 March. R-band lightcurves were obtained on 11 of these nights from 1999 April through 1999 June, prior to both the onset of significant coma activity and perihelion. Phasing of the data yields a double-peaked lightcurve and indicates a nucleus rotational period of 8.941 +/- 0.002 hr with a peak-to-peak amplitude of ~0.75 mag. Our data are sufficient to rule out all other possible double-peaked solutions as well as the single- and triple- peaked solutions. This rotation period agrees with one of five possible solutions found in post-perihelion data from 1994 by Mueller and Ferrin (1996, Icarus, 123, 463-477), and unambiguously eliminates their remaining four solutions. We applied our same techniques to published lightcurves from 1988 which were obtained at an equivalent orbital position and viewing geometry as in 1999. We found a rotation period of 8.932 +/- 0.001 hr in 1988, consistent with the findings of previous authors and incompatible with our 1999 solution. This reveals that Tempel 2 spun-down by ~32 s between 1988 and 1999 (two intervening perihelion passages). If the spin-down is due to a systematic torque, then the rotation period prior to perihelion during the 2010 apparition is expected to be an additional 32 s longer than in 1999.Comment: Accepted by The Astronomical Journal; 22 pages of text, 3 tables, 6 figure

Tackling an intractable problem: can greater taxon sampling help resolve relationships within the Stenopelmatoidea (Orthoptera: Ensifera)?

The relationships among and within the families that comprise the orthopteran superfamily Stenopelmatoidea (suborder Ensifera) remain poorly understood. We developed a phylogenetic hypothesis based on Bayesian analysis of two nuclear ribosomal and one mitochondrial gene for 118 individuals (84 de novo and 34 from GenBank). These included Gryllacrididae from North, Central, and South America, South Africa and Madagascar, Australia and Papua New Guinea; Stenopelmatidae from North and Central America and South Africa; Anostostomatidae from North and Central America, Papua New Guinea, New Zealand, Australia, and South Africa; members of the Australian endemic Cooloola (three species); and a representative of Lezina from the Middle East. We also included representatives of all other major ensiferan families: Prophalangopsidae, Rhaphidophoridae, Schizodactylidae, Tettigoniidae, Gryllidae, Gryllotalpidae and Myrmecophilidae and representatives of the suborder Caelifera as outgroups. Bayesian analyses of concatenated sequence data supported a clade of Stenopelmatoidea inclusive of all analyzed members of Gryllacrididae, Stenopelmatidae, Anostostomatidae, Lezina and Cooloola. We found Gryllacrididae worldwide to be monophyletic, while we did not recover a monophyletic Stenopelmatidae nor Anostostomatidae. Australian Cooloola clustered in a clade composed of Australian, New Zealand, and some (but not all) North American Anostostomatidae. Lezina was included in a clade of New World Anostostomatidae. Finally, we compiled and compared karyotypes and sound production characteristics for each supported group. Chromosome number, centromere position, drumming, and stridulation differed among some groups, but also show variation within groups. This preliminary trait information may contribute toward future studies of trait evolution. Despite greater taxon sampling within Stenopelmatoidea than previous efforts, some relationships among the families examined continue to remain elusive

Warm Parenting Throughout Adolescence Predicts Basal Parasympathetic Activity Among Mexican‐Origin Youths

Parenting that is warm and supportive has been consistently linked to better emotion regulation in children, but less is known about this association in adolescents. Adolescence is thought to be an important period for emotion regulation development given that it coincides with the emergence of mental health issues. Respiratory sinus arrhythmia (RSA) is a measure of parasympathetic regulation linked to emotion and behavior regulation. Despite the well-documented links between parenting practices and emotion regulation, and between RSA and emotion regulation, few studies have focused on the association between positive parenting and adolescent RSA or included both mothers and fathers. The current study analyzed the influence of warm parenting throughout adolescence (ages 10-16) on basal RSA at age 17 in 229 Mexican-origin youths. Latent-growth curve models were used to analyze associations between maternal and paternal warmth and baseline RSA. Changes in maternal, but not paternal, warmth from age 10 to 16 were related to youths' basal RSA at age 17. Specifically, youths who perceived increasing (or less decreasing) maternal warmth across adolescence had higher basal RSA. This finding suggests that positive maternal parenting experiences during adolescence "get under the skin" to enhance parasympathetic functioning that supports youths' emotion regulation capacities

Neural connectivity biotypes: associations with internalizing problems throughout adolescence.

BackgroundNeurophysiological patterns may distinguish which youth are at risk for the well-documented increase in internalizing symptoms during adolescence. Adolescents with internalizing problems exhibit altered resting-state functional connectivity (RSFC) of brain regions involved in socio-affective processing. Whether connectivity-based biotypes differentiate adolescents' levels of internalizing problems remains unknown.MethodSixty-eight adolescents (37 females) reported on their internalizing problems at ages 14, 16, and 18 years. A resting-state functional neuroimaging scan was collected at age 16. Time-series data of 15 internalizing-relevant brain regions were entered into the Subgroup-Group Iterative Multi-Model Estimation program to identify subgroups based on RSFC maps. Associations between internalizing problems and connectivity-based biotypes were tested with regression analyses.ResultsTwo connectivity-based biotypes were found: a Diffusely-connected biotype (N = 46), with long-range fronto-parietal paths, and a Hyper-connected biotype (N = 22), with paths between subcortical and medial frontal areas (e.g. affective and default-mode network regions). Higher levels of past (age 14) internalizing problems predicted a greater likelihood of belonging to the Hyper-connected biotype at age 16. The Hyper-connected biotype showed higher levels of concurrent problems (age 16) and future (age 18) internalizing problems.ConclusionsDifferential patterns of RSFC among socio-affective brain regions were predicted by earlier internalizing problems and predicted future internalizing problems in adolescence. Measuring connectivity-based biotypes in adolescence may offer insight into which youth face an elevated risk for internalizing disorders during this critical developmental period

Exposure to Violence as an Environmental Pathway Linking Low Socioeconomic Status with Altered Neural Processing of Threat and Adolescent Psychopathology

Low childhood socioeconomic status (SES) is associated with increased risk for psychopathology, in part because of heightened exposure to environmental adversity. Adverse experiences can be characterized along dimensions, including threat and deprivation, that contribute to psychopathology via distinct mechanisms. The current study investigated a neural mechanism through which threat and deprivation may contribute to socioeconomic disparities in psychopathology. Participants were 177 youths (83 girls) aged 10–13 years recruited from a cohort followed since the age of 3 years. SES was assessed using the income-to-needs ratio at the age of 3 years. At the age of 10–13 years, retrospective and current exposure to adverse experiences and symptoms of psychopathology were assessed. At this same time point, participants also com-pleted a face processing task (passive viewing of fearful and neutral faces) during an fMRI scan. Lower childhood SES was associated with greater exposure to threat and deprivation experiences. Both threat and deprivation were associated with higher depression symptoms, whereas threat experiences were uniquely linked to posttraumatic stress disorder symp-toms. Greater exposure to threat, but not deprivation, was associated with higher activation in dorsomedial pFC to fearful compared with neutral faces. The dorsomedial pFC is a hub of the default mode network thought to be involved in internally directed attention and cognition. Experiences of threat, but not deprivation, are associated with greater engagement of this region in response to threat cues. Threat-related adversity contributes to socioeconomic disparities in adolescent psychopathology through distinct mechanisms from deprivation

Contributions of Emotion Regulation and Brain Structure and Function to Adolescent Internalizing Problems and Stress Vulnerability During the COVID-19 Pandemic: A Longitudinal Study

Background: Adolescence is a period of increased vulnerability for internalizing problems, particularly following stressful life events. We examined how emotion regulation and brain structure and function were associated with internalizing problems during the COVID-19 pandemic and moderated the association between pandemic-related stressors and internalizing problems. Methods: Data are from a longitudinal sample (N = 145, age range, 10–15 years) strategically assessed at 3 crucial time points: before the COVID-19 pandemic, early during the stay-at-home order period, and again 6 months later. We examined associations of amygdala and hippocampal volume and amygdala activation during an emotional processing task before the pandemic, examined use of emotion regulation strategies before and during the pandemic, and examined pandemic-related stressors with internalizing problems. Results: Greater exposure to pandemic-related stressors was associated with higher internalizing problems both early and later in the COVID-19 pandemic. Youths who reported more frequent use of rumination before the pandemic and higher use of expressive suppression and lower use of cognitive reappraisal early in the pandemic had higher internalizing problems early in the pandemic. Higher left amygdala activation to neutral relative to fearful faces before the pandemic was associated with greater internalizing problems and a stronger link between pandemic-related stressors and internalizing problems early in the pandemic. Conclusions: Stressors related to the COVID-19 pandemic are strongly associated with adolescent internalizing problems, as are individual differences in emotional reactivity and regulation and their underlying neural mechanisms. Interventions that reduce pandemic-related stressors and foster adaptive emotion regulation skills may protect against adolescent psychopathology during this period of heightened exposure to stress

WISE/NEOWISE Preliminary Analysis and Highlights of the 67P/Churyumov-Gerasimenko Near Nucleus Environs

On January 18-19 and June 28-29 of 2010, the Wide-field Infrared Survey Explorer (WISE) spacecraft imaged the Rosetta mission target, comet 67P/Churyumov-Gerasimenko. We present a preliminary analysis of the images, which provide a characterization of the dust environment at heliocentric distances similar to those planned for the initial spacecraft encounter, but on the outbound leg of its orbit rather than the inbound. Broad-band photometry yields low levels of CO2 production at a comet heliocentric distance of 3.32 AU and no detectable production at 4.18 AU. We find that at these heliocentric distances, large dust grains with mean grain diameters on the order of a millimeter or greater dominate the coma and evolve to populate the tail. This is further supported by broad-band photometry centered on the nucleus, which yield an estimated differential dust particle size distribution with a power law relation that is considerably shallower than average. We set a 3-sigma upper limit constraint on the albedo of the large-grain dust at <= 0.12. Our best estimate of the nucleus radius (1.82 +/- 0.20 km) and albedo (0.04 +/- 0.01) are in agreement with measurements previously reported in the literature

Polymer-based paclitaxel-eluting stents reduce in-stent neointimal tissue proliferation A serial volumetric intravascular ultrasound analysis from the TAXUS-IV trial

ObjectivesThe aim of this study was to use serial volumetric intravascular ultrasound (IVUS) to evaluate the effects of polymer-based, paclitaxel-eluting stents on in-stent neointima formation and late incomplete stent apposition.BackgroundThe TAXUS-IV trial demonstrated that the slow-release, polymer-based, paclitaxel-eluting stent reduces angiographic restenosis and the need for repeat revascularization procedures. Serial IVUS studies reveal details of the pattern of vascular responses provoked by stent implantation that provide insight into device safety and efficacy.MethodsIn the TAXUS-IV trial, patients were randomized to the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or a bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). As part of a formal substudy, complete volumetric IVUS data were available in 170 patients, including 88 TAXUS patients and 82 controls, at implantation and at nine-month follow-up.ResultsNo baseline differences were present in the clinical characteristics or IVUS parameters between the control and TAXUS groups. At nine-month follow-up, IVUS lumen volumes were larger in the TAXUS group (123 ± 43 mm3vs. 104 ± 44 mm3, p = 0.005), due to a reduction in neointimal volume (18 ± 18 mm3vs. 41 ± 23 mm3, p < 0.001). Millimeter-by-millimeter analysis within the stent demonstrated uniform suppression of neointimal growth along the entire stent length. Late lumen loss was similar at the proximal edge of the stent between the two groups, and reduced with the TAXUS stent at the distal edge (p = 0.004). Incomplete stent apposition at nine months was observed in only 3.0% of control and 4.0% of TAXUS stents (p = 0.12).ConclusionsPolymer-based, paclitaxel-eluting TAXUS stents are effective in inhibiting neointimal tissue proliferation, and do not result in late incomplete stent apposition

A prudent path forward for genomic engineering and germline gene modification

A framework for open discourse on the use of CRISPR-Cas9 technology to manipulate the human genome is urgently needed

BRG1 co-localizes with DNA replication factors and is required for efficient replication fork progression

For DNA replication to occur, chromatin must be remodeled. Yet, we know very little about which proteins alter nucleosome occupancy at origins and replication forks and for what aspects of replication they are required. Here, we demonstrate that the BRG1 catalytic subunit of mammalian SWI/SNF-related complexes co-localizes with origin recognition complexes, GINS complexes, and proliferating cell nuclear antigen at sites of DNA replication on extended chromatin fibers. The specific pattern of BRG1 occupancy suggests it does not participate in origin selection but is involved in the firing of origins and the process of replication elongation. This latter function is confirmed by the fact that Brg1 mutant mouse embryos and RNAi knockdown cells exhibit a 50% reduction in replication fork progression rates, which is associated with decreased cell proliferation. This novel function of BRG1 is consistent with its requirement during embryogenesis and its role as a tumor suppressor to maintain genome stability and prevent cancer