Parent-child relationships in context: an application of the person-process-context-time model to the development of low-income toddlers' social-emotional adjustment

2016 Summer.Includes bibliographical references.This dual manuscript dissertation addresses current empirical evidence and developmental theory that acknowledges the active role of the toddler in shaping ontogeny. As such, both studies utilized cross-lagged panel models to investigate the longitudinal, bidirectional associations among different features of the microsystem and the child, using repeated measures data from the Early Head Start and Evaluation Research Project (EHSREP; 1996-2010). In the first study, transactional relations between observed maternal supportiveness and child emotion regulation at age 14-, 24-, and 36-months were evaluated. Results supported extant research that establishes significant longitudinal associations between more supportive mother behavior and higher levels of child emotion regulation, net the stability in these constructs over time; there was no evidence to support child-driven pathways, or a developmental transaction. This model was then assessed with the addition of the total home environment measure across time points. Both child emotion regulation and the home environment significantly predicted each other from child age 2 to 3, while maternal supportiveness remained a significant predictor of emotion regulation, but only at age 2. These results suggest that different facets of the child’s microsystem may become more salient at different times in development, and the child emerges as an influence on the microsystem in his or her own right. Findings also underscore the need for research that compares the predictive utility of parent-child interaction measures and the home environment for diverse developmental outcomes. The second study incorporated toddlers’ negative emotionality into a cross-lagged panel model of maternal depressive symptoms, maternal supportiveness, and child externalizing behaviors. A central goal of this study was to incorporate process-oriented questions about the linkage between individual differences in child temperament, maternal risk, parenting, and child externalizing behaviors (mediation), while also addressing questions about for whom these pathways are most relevant (moderation). Maternal depressive symptoms predicted subsequent child behavior problems; in turn, child behavior problems predicted later depressive symptoms. Child negative emotionality at 14 months demonstrated an indirect effect on maternal depressive symptoms at 3 years by way of externalizing behavior at 2 years. Nonsignificant tests of moderation rendered the current study unable to generate support for diathesis-stress or differential susceptibility models in the current sample. Results imply the emergence of parent-driven transactions between maternal depressive symptoms and child externalizing behaviors within the first few years of life. Moreover, the temperamental characteristic of negative emotionality connotes further risk for maladjustment for both mother and child. Collectively, both studies highlight the need for continued research and interventions that consider the child’s contributions to the dynamic process of development during toddlerhood

Different Outcomes of Experimental Hepatitis E Virus Infection in Diverse Mouse Strains, Wistar Rats, and Rabbits

Hepatitis E virus (HEV) is the causative agent of acute hepatitis E in humans in developing countries, but autochthonous cases of zoonotic genotype 3 (HEV-3) infection also occur in industrialized countries. In contrast to swine, rats, and rabbits, natural HEV infections in mice have not yet been demonstrated. The pig represents a well-established large animal model for HEV-3 infection, but a suitable small animal model mimicking natural HEV-3 infection is currently missing. Therefore, we experimentally inoculated C57BL/6 mice (wild-type, IFNAR−/−, CD4−/−, CD8−/−) and BALB/c nude (nu/nu) mice, Wistar rats, and European rabbits with a wild boar-derived HEV-3 strain and monitored virus replication and shedding, as well as humoral immune responses. HEV RNA and anti-HEV antibodies were detected in one and two out of eight of the rats and all rabbits inoculated, respectively, but not in any of the mouse strains tested. Remarkably, immunosuppressive dexamethasone treatment of rats did not enhance their susceptibility to HEV infection. In rabbits, immunization with recombinant HEV-3 and ratHEV capsid proteins induced protection against HEV-3 challenge. In conclusion, the rabbit model for HEV-3 infection may serve as a suitable alternative to the non-human primate and swine models, and as an appropriate basis for vaccine evaluation studies

Against the current - Clearfield® oilseed rape in Germany

The introduction of imidazolinone-tolerant oilseed rape (Clearfield® system, CL; OSR) meets with scepticism in Germany. Frequently mentioned as a major drawback for growing CL-OSR in Germany is the possible occurrence of herbicide resistant CL-volunteers which could run out of control. A monitoring was started by BASF in the seasons 2011/2012/2013 on farms in Germany prior to commercial launching of the Clearfield® system. Aim of this phase was, among others, to analyse the potential for occurrence and survival of volunteers, and to identify factors which promote or minimize volunteers. The University of Hohenheim monitored 41 farms in nearly all regions of Germany during spring 2013 in the crops following to CL-OSR (harvested in summer 2012), mostly winter wheat. Volunteer OSR was counted on the fields and molecularbiologically analysed, and the soil seed bank was investigated in 0 – 30 cm soil depth. Additionally, data about field history and cultivation were gathered. Several CL-varieties were tested at the same time in the laboratory for secondary dormancy. First results showed variation in dormancy from high (>90%) to nearly no dormancy of the tested CL-varieties, similar to common varieties. The situation on farmers fields corresponded to dormancy values: 40 – 49% of all farms had no CL-soil seedbank or volunteers at all, and a maximum of 1000 CL seeds m-2 and two CL-volunteers m-2 were observed on the other farms. Conventional seed banks and volunteers additionally occurred on the majority of the farms. Overall, seed survival and volunteer emergence of CL-OSR can be assessed as medium-low compared to previous studies with conventional varieties. Volunteers observed after CL growing do not necessarily originate from this crop. The regression analysis showed no clear effects, probably because of the low number of sampling sites. This monitoring did not reveal specific disadvantages linked with CL-oilseed rape in terms of volunteers.Keywords: Brassica napus, Clearfield®, dormancy, soil seed bank, variety, volunteersGegen den Strom – Clearfield-Raps in DeutschlandZusammenfassungDie Einführung von Imidazolinon-tolerantem Raps (Clearfield®-System, CL-Raps) stößt in Deutschland auf Skepsis. Ein häufig genannter Nachteil des CL-Rapses in Deutschland ist das mögliche Auftreten von herbizidtolerantem und schwer bekämpfbarem CL-Durchwuchs. Daher wurde von der BASF in den Jahren 2011/2012/2013 vor der Einführung des Clearfield®-Systems ein Probeanbau und ein Monitoring auf landwirtschaftlichen Betrieben in ganz Deutschland vorgenommen. Ziel war unter anderem, das Potential für das Auftreten von Durchwuchsraps zu analysieren und Faktoren zu identifizieren, die zu Durchwuchsraps führen. Die Universität Hohenheim hat bei diesem Monitoring im Frühjahr 2013 Flächen (überwiegend Winterweizen) auf 41 Betrieben in ganz Deutschland untersucht, auf denen im Vorjahr CL-Raps geerntet worden war. Durchwuchsraps wurde gezählt und molekularbiologisch analysiert; weiterhin erfolgte eine Bodenprobennahme in einer Bodentiefe von 0 – 30 cm auf 20 Flächen zur Bestimmung des Bodensamenvorrats an Raps. Über einen Fragebogen wurden zusätzliche Informationen zu Schlaghistorie und Anbauverfahren abgefragt. Parallel dazu wurden die angebauten sowie weitere CL-Sorten im Labor auf sekundäre Dormanz getestet. Zwischen den Sorten zeigten sich die schon bei konventionellem Raps bekannten Unterschiede in der Dormanz, die von hoch dormant (> 90 %) bis nahezu nicht dormant reichten. Auf den Praxisbetrieben ergab sich ein ähnliches Bild: auf 40 – 49 % der Betriebe wurden weder ein CL-Bodensamenvorrat bzw. noch CL-Durchwuchsraps gefunden. Der Durchwuchs auf den anderen Betrieben belief sich auf maximal rund zwei CL-Durchwuchspflanzen m-2, und knapp 1000 CL-Samen m-2 waren maximal im Samenvorrat. Auf den meisten Flächen fanden sich zusätzlich konventioneller Durchwuchsraps bzw. Bodensamenvorrat oder Kreuzungen zwischen konventionellem und CL-Raps. Insgesamt kann der Besatz mit CL-Durchwuchs im Vergleich zu Studien mit konventionellem Durchwuchs als mittel bis gering eingestuft werden. Die Regressionsanalyse ergab bei der geringen Anzahl geprüfter Flächen wenig einheitliche und eindeutige Ergebnisse. Mit dem Anbau von CL-Raps scheinen auf den Monitoringflächen keine besonderen Nachteile im Hinblick auf Durchwuchsraps verbunden gewesen zu sein.Stichwörter: Brassica napus, Bodensamenvorrat, Clearfield®, Dormanz, Durchwuchs, Sort

Formation of Topological Defects in a Second Order Phase Transition

The classical evolution equations of the Abelian Higgs model are studied at temperatures below the Ginsburg temperature of a phase transition which is assumed to be second order. It is shown that the initial thermal fluctuations provide a domain structure which is stable against late time fluctuations. This result lends support to the Kibble mechanism for the formation of topological defects.Comment: Brown preprint BROWN-HET-934 (March 1994), 12 pages, uses phyzz

Математическое моделирование процессов тепло- и массопереноса в условиях интенсивного локального лазерного нагрева многослойной полиметаллической пластины.

Проведено математическое моделирование процессов теплопереноса, протекающих совместно в условиях интенсивных фазовых превращений (плавление и испарение металлов) при лазерном воздействии на диметаллическую мишень. По результатам численного моделирования установлено, что мощность лазера оказывает существенное влияние на динамику процесса плавления. Показано, что испарение металла в пограничный слой пластины также может оказывать существенное влияние на характеристики теплопереноса. Установлено, что металлические пары, формируя в пристеночной области газовую смесь могут поглощать лазерное излучение и вызывать явление оптического резонанса при повышении их концентрации критического значения, другими словами, при плавлении металла возможен оптический пробой.Mathematical modeling of heat transfer processes proceeding together under conditions of intense phase transformations (melting and evaporation of metals) under laser action on a dimetallic target has been carried out. Based on the results of numerical simulation, it is established that the laser power exerts a significant influence on the dynamics of the melting process. It is shown that evaporation of metal in the boundary layer of the plate can also have a significant effect on the heat transfer characteristics. It is established that metal vapors forming a gas mixture in the near-wall region can absorb laser radiation and cause the phenomenon of optical resonance with increasing their critical concentration, in other words, when the metal melts, optical breakdown is possible

Inhibition of HIV-1 in Cell Culture by Synthetic Humate Analogues Derived from Hydroquinone: Mechanism of Inhibition

AbstractHumic acids are natural constituents of soil and ground water and mainly consist of mixtures of polycyclic phenolic compounds. A similar complex of compounds with a mean size of about 1000 Da, designated HS-1500, was synthesized by oxidation of hydroquinone. HS-1500 inhibited HIV-1 infection of MT-2 cells with an IC50of 50–300 ng/ml and showed a mean cell toxicity of about 600 μg/ml. Inhibition of HIV-induced syncytium formation was observed at 10–50 μg/ml. Treatment of free and cell-attached HIV with HS-1500 irreversibly reduced its infectivity, whereas the susceptibility of target cells for the virus was not impaired by treatment prior to infection. The HIV envelope protein gp120SU bound to sepharose-coupled HS-1500 and could be eluted by high salt and detergent. HS-1500 interfered with the CD4-induced proteolytic cleavage of the V3 loop of virion gp120SU. Furthermore, binding of V3 loop-specific antibodies was irreversibly inhibited, whereas binding of soluble CD4 to gp120SU on virus and infected cells was not affected. In conclusion, our data suggest, that the synthetic humic acid analogue inhibits the infectivity of HIV particles by interference with a V3 loop-mediated step of virus entry