Keeping all options open: Parents' approaches to advance care planning.

Science.gov (United States)

Beecham, Emma; Oostendorp, Linda; Crocker, Joanna; Kelly, Paula; Dinsdale, Andrew; Hemsley, June; Russell, Jessica; Jones, Louise; Bluebond-Langner, Myra

2017-08-01

Early engagement in advance care planning (ACP) is seen as fundamental for ensuring the highest standard of care for children and young people with a life-limiting condition (LLC). However, most families have little knowledge or experience of ACP. To investigate how parents of children and young people with LLCs approach and experience ACP. Open-ended, semi-structured interviews were conducted with parents of 18 children; nine children who were currently receiving palliative care services, and nine children who had received palliative care and died. Verbatim transcripts of audiotaped interviews were analysed following principles of grounded theory while acknowledging the use of deductive strategies, taking account of both the child's condition, and the timing and nature of decisions made. Parents reported having discussions and making decisions about the place of care, place of death and the limitation of treatment. Most decisions were made relatively late in the illness and by parents who wished to keep their options open. Parents reported different levels of involvement in a range of decisions; many wished to be involved in decision making but did not always feel able to do so. This study highlights that parents' approaches to decision making vary by the type of decision required. Their views may change over time, and it is important to allow them to keep their options open. We recommend that clinicians have regular discussions over the course of the illness in an effort to understand parents' approaches to particular decisions rather than to drive to closure prematurely. © 2016 The Authors Health Expectations Published by John Wiley & Sons Ltd.

Neutron star/red giant encounters in globular clusters

International Nuclear Information System (INIS)

Bailyn, C.D.

1988-01-01

The author presents a simple expression for the amount by which xsub(crit) is diminished as a star evolves xsub(crit) Rsub(crit)/R*, where Rsub(crit) is the maximum distance of closest approach between two stars for which the tidal energy is sufficient to bind the system, and R* is the radius of the star on which tides are being raised. Also it is concluded that tidal capture of giants by neutron stars resulting in binary systems is unlikely in globular clusters. However, collisions between neutron stars and red giants, or an alternative process involving tidal capture of a main-sequence star into an initially detached binary system, may result either in rapidly rotating neutron stars or in white dwarf/neutron star binaries. (author)

Using Consumer Preference Information to Increase the Reach and Impact of Media-Based Parenting Interventions in a Public Health Approach to Parenting Support

Science.gov (United States)

Metzler, Carol W.; Sanders, Matthew R.; Rusby, Julie C.; Crowley, Ryann N.

2012-01-01

Within a public health approach to improving parenting, the mass media offer a potentially more efficient and affordable format for directly reaching a large number of parents with evidence-based parenting information than do traditional approaches to parenting interventions that require delivery by a practitioner. Little is known, however, about…

Field O stars: formed in situ or as runaways?

Science.gov (United States)

Gvaramadze, V. V.; Weidner, C.; Kroupa, P.; Pflamm-Altenburg, J.

2012-08-01

A significant fraction of massive stars in the Milky Way and other galaxies are located far from star clusters and star-forming regions. It is known that some of these stars are runaways, i.e. possess high space velocities (determined through the proper motion and/or radial velocity measurements), and therefore most likely were formed in embedded clusters and then ejected into the field because of dynamical few-body interactions or binary-supernova explosions. However, there exists a group of field O stars whose runaway status is difficult to prove via direct proper motion measurements (e.g. in the Magellanic Clouds) or whose (measured) low space velocities and/or young ages appear to be incompatible with their large separation from known star clusters. The existence of this group led some authors to believe that field O stars can form in situ. Since the question of whether or not O stars can form in isolation is of crucial importance for star formation theory, it is important to thoroughly test candidates of such stars in order to improve the theory. In this paper, we examine the runaway status of the best candidates for isolated formation of massive stars in the Milky Way and the Magellanic Clouds by searching for bow shocks around them, by using the new reduction of the Hipparcos data, and by searching for stellar systems from which they could originate within their lifetimes. We show that most of the known O stars thought to have formed in isolation are instead very likely runaways. We show also that the field must contain a population of O stars whose low space velocities and/or young ages are in apparent contradiction to the large separation of these stars from their parent clusters and/or the ages of these clusters. These stars (the descendants of runaway massive binaries) cannot be traced back to their parent clusters and therefore can be mistakenly considered as having formed in situ. We argue also that some field O stars could be detected in optical

STARDUST FROM ASYMPTOTIC GIANT BRANCH STARS

International Nuclear Information System (INIS)

Gail, H.-P.; Zhukovska, S. V.; Hoppe, P.; Trieloff, M.

2009-01-01

The formation of dust in the outflows of low- and intermediate-mass stars on the first giant branch and asymptotic giant branch (AGB) is studied and the relative contributions of stars of different initial masses and metallicities to the interstellar medium (ISM) at the instant of solar system formation are derived. These predictions are compared with the characteristics of the parent stars of presolar dust grains found in primitive meteorites and interplanetary dust particles (IDPs) inferred from their isotopic compositions. For this purpose, model calculations for dust condensation in stellar outflows are combined with synthetic models of stellar evolution on the first giant branch and AGB and an evolution model of the Milky Way for the solar neighborhood. The dust components considered are olivine, pyroxene, carbon, SiC, and iron. The corresponding dust production rates are derived for the solar vicinity. From these rates and taking into account dust destruction by supernova shocks in the ISM, the contributions to the inventory of presolar dust grains in the solar system are derived for stars of different initial masses and metallicities. It is shown that stars on the first giant branch and the early AGB are not expected to form dust, in accord with astronomical observations. Dust formation is concentrated in the last phase of evolution, the thermally pulsing AGB. Due to the limited lifetime of dust grains in the ISM only parent stars from a narrow range of metallicities are expected to contribute to the population of presolar dust grains. Silicate and silicon carbide dust grains are predicted to come from parent stars with metallicities not less than about Z ∼ 0.008 (0.6 x solar). This metallicity limit is higher than that inferred from presolar SiC grain isotope data. The population of presolar carbon dust grains is predicted to originate from a wider range of metallicities, down to Z ∼ 0.004. Masses of AGB stars that produce C-rich dust are in the range �

Thermodynamics of compact-star matter within an Ising approach

International Nuclear Information System (INIS)

Chomaz, P.; Ducoin, C.; Gulminelli, F.; Hasnaoui, K.; Napolitani, P.

2007-01-01

In the formation and evolution of compact stars, nuclear matter explores high thermal excursions and is the site of intense neutrino emission. Neutrino transport as well as structural properties of this matter depend on the presence of inhomogeneous phases (named 'pasta' phases), which are the result of Coulomb frustration of the Liquid-Gas phase transition. We take into account charge fluctuations by employing a frustrated lattice-gas model to which we impose a neutrality constraint by the addition of an homogeneous background of charge, representing delocalized electrons. Within this schematic model we highlight a generic feature of the phase-transition phenomenology: the temperature interval where pasta phases are formed is enhanced by Coulomb-frustration effects. This result is at variance with the behaviour of frustrated ferromagnetic systems as well as hot nuclei and mean-field approaches. Moreover, the region of phase coexistence is not found to end upon a critical point, indicating that no critical opalescence can occur in compact-star matter

Thermodynamics of compact-star matter within an Ising approach

Energy Technology Data Exchange (ETDEWEB)

Chomaz, P. [Ganil (DSM-CEA/IN2P3-CNRS), Blvd. H. Becquerel, BP 55027, F-14076 Caen cedex 5 (France); Ducoin, C. [Ganil (DSM-CEA/IN2P3-CNRS), Blvd. H. Becquerel, BP 55027, F-14076 Caen cedex 5 (France); LPC - IN2P3-CNRS/Ensicaen et Universite, F-14076 Caen cedex (France); Gulminelli, F. [LPC - IN2P3-CNRS/Ensicaen et Universite, F-14076 Caen cedex (France); Hasnaoui, K. [Ganil (DSM-CEA/IN2P3-CNRS), Blvd. H. Becquerel, BP 55027, F-14076 Caen cedex 5 (France); Napolitani, P. [Ganil (DSM-CEA/IN2P3-CNRS), Blvd. H. Becquerel, BP 55027, F-14076 Caen cedex 5 (France); LPC - IN2P3-CNRS/Ensicaen et Universite, F-14076 Caen cedex (France)

2007-05-01

In the formation and evolution of compact stars, nuclear matter explores high thermal excursions and is the site of intense neutrino emission. Neutrino transport as well as structural properties of this matter depend on the presence of inhomogeneous phases (named 'pasta' phases), which are the result of Coulomb frustration of the Liquid-Gas phase transition. We take into account charge fluctuations by employing a frustrated lattice-gas model to which we impose a neutrality constraint by the addition of an homogeneous background of charge, representing delocalized electrons. Within this schematic model we highlight a generic feature of the phase-transition phenomenology: the temperature interval where pasta phases are formed is enhanced by Coulomb-frustration effects. This result is at variance with the behaviour of frustrated ferromagnetic systems as well as hot nuclei and mean-field approaches. Moreover, the region of phase coexistence is not found to end upon a critical point, indicating that no critical opalescence can occur in compact-star matter.

Thermodynamics of compact-star matter within an Ising approach

Science.gov (United States)

Chomaz, P.; Ducoin, C.; Gulminelli, F.; Hasnaoui, K.; Napolitani, P.

2007-05-01

In the formation and evolution of compact stars, nuclear matter explores high thermal excursions and is the site of intense neutrino emission. Neutrino transport as well as structural properties of this matter depend on the presence of inhomogeneous phases (named "pasta" phases), which are the result of Coulomb frustration of the Liquid-Gas phase transition. We take into account charge fluctuations by employing a frustrated lattice-gas model to which we impose a neutrality constraint by the addition of an homogeneous background of charge, representing delocalised electrons. Within this schematic model we highlight a generaic feature of the phase-transition phenomenology: the temperature interval where pasta phases are formed is enhanced by Coulomb-frustration effects. This result is at variance with the behaviour of frustrated ferromagnetic systems as well as hot nuclei and mean-field approaches. Moreover, the region of phase coexistence is not found to end upon a critical point, indicating that no critical opalescence can occur in compact-star matter.

Parenting approaches and digital technology use of preschool age children in a Chinese community.

Science.gov (United States)

Wu, Cynthia Sau Ting; Fowler, Cathrine; Lam, Winsome Yuk Yin; Wong, Ho Ting; Wong, Charmaine Hei Man; Yuen Loke, Alice

2014-05-07

Young children are using digital technology (DT) devices anytime and anywhere, especially with the invention of smart phones and the replacement of desktop computers with digital tablets. Although research has shown that parents play an important role in fostering and supporting preschoolers' developing maturity and decisions about DT use, and in protecting them from potential risk due to excessive DT exposure, there have been limited studies conducted in Hong Kong focusing on parent-child DT use. This study had three objectives: 1) to explore parental use of DTs with their preschool children; 2) to identify the DT content that associated with child behavioral problems; and 3) to investigate the relationships between approaches adopted by parents to control children's DT use and related preschooler behavioral problems. This exploratory quantitative study was conducted in Hong Kong with 202 parents or guardians of preschool children between the ages of 3 and 6 attending kindergarten. The questionnaire was focused on four aspects, including 1) participants' demographics; 2) pattern of DT use; 3) parenting approach to manage the child's DT use; and 4) child behavioral and health problems related to DT use. Multiple regression analysis was adopted as the main data analysis method for identifying the DT or parental approach-related predictors of the preschooler behavioral problems. In the multiple linear regression model, the 'restrictive approach score' was the only predictor among the three parental approaches (B:1.66, 95% CI: [0.21, 3.11], p children also significantly increased the tendency of children to have behavioral problem (B:3.84, 95% CI: [1.66, 6.02], p children's cognitive and functional abilities are still in the developmental stage, parents play a crucial role in fostering appropriate and safe DT use. It is suggested that parents practice a combination of restrictive, instructive and co-using approaches, rather than a predominately restrictive

CAF: Cluster algorithm and a-star with fuzzy approach for lifetime enhancement in wireless sensor networks

KAUST Repository

Yuan, Y.; Li, C.; Yang, Y.; Zhang, Xiangliang; Li, L.

2014-01-01

Energy is a major factor in designing wireless sensor networks (WSNs). In particular, in the real world, battery energy is limited; thus the effective improvement of the energy becomes the key of the routing protocols. Besides, the sensor nodes are always deployed far away from the base station and the transmission energy consumption is index times increasing with the increase of distance as well. This paper proposes a new routing method for WSNs to extend the network lifetime using a combination of a clustering algorithm, a fuzzy approach, and an A-star method. The proposal is divided into two steps. Firstly, WSNs are separated into clusters using the Stable Election Protocol (SEP) method. Secondly, the combined methods of fuzzy inference and A-star algorithm are adopted, taking into account the factors such as the remaining power, the minimum hops, and the traffic numbers of nodes. Simulation results demonstrate that the proposed method has significant effectiveness in terms of balancing energy consumption as well as maximizing the network lifetime by comparing the performance of the A-star and fuzzy (AF) approach, cluster and fuzzy (CF)method, cluster and A-star (CA)method, A-star method, and SEP algorithm under the same routing criteria. 2014 Yali Yuan et al.

CAF: Cluster algorithm and a-star with fuzzy approach for lifetime enhancement in wireless sensor networks

KAUST Repository

Yuan, Y.

2014-04-28

Energy is a major factor in designing wireless sensor networks (WSNs). In particular, in the real world, battery energy is limited; thus the effective improvement of the energy becomes the key of the routing protocols. Besides, the sensor nodes are always deployed far away from the base station and the transmission energy consumption is index times increasing with the increase of distance as well. This paper proposes a new routing method for WSNs to extend the network lifetime using a combination of a clustering algorithm, a fuzzy approach, and an A-star method. The proposal is divided into two steps. Firstly, WSNs are separated into clusters using the Stable Election Protocol (SEP) method. Secondly, the combined methods of fuzzy inference and A-star algorithm are adopted, taking into account the factors such as the remaining power, the minimum hops, and the traffic numbers of nodes. Simulation results demonstrate that the proposed method has significant effectiveness in terms of balancing energy consumption as well as maximizing the network lifetime by comparing the performance of the A-star and fuzzy (AF) approach, cluster and fuzzy (CF)method, cluster and A-star (CA)method, A-star method, and SEP algorithm under the same routing criteria. 2014 Yali Yuan et al.

Parental Reflective Functioning: An Approach to Enhancing Parent-Child Relationships in Pediatric Primary Care.

Science.gov (United States)

Ordway, Monica Roosa; Webb, Denise; Sadler, Lois S; Slade, Arietta

2015-01-01

The current state of science suggests that safe, responsive, and nurturing parent-child relationships early in children's lives promotes healthy brain and child development and protection against lifelong disease by reducing toxic stress and promoting foundational social-emotional health. Pediatric health care providers (HCPs) have a unique opportunity to foster these relationships. However, such a role requires a shift in pediatric health care from a focus only on children to one that includes families and communities, as well as the inclusion of children's social and emotional health with their physical health. To foster healthy parent-child relationships, HCPs must develop the expertise to integrate approaches that support the family's socioemotional health into pediatric primary care. This article suggests ways in which pediatric HCPs can integrate a focus on parental reflective functioning into their clinical work, helping parents to understand some of the thoughts and feelings that underlie their children's behavior. Copyright © 2015 National Association of Pediatric Nurse Practitioners. Published by Elsevier Inc. All rights reserved.

RADIAL STABILITY IN STRATIFIED STARS

International Nuclear Information System (INIS)

Pereira, Jonas P.; Rueda, Jorge A.

2015-01-01

We formulate within a generalized distributional approach the treatment of the stability against radial perturbations for both neutral and charged stratified stars in Newtonian and Einstein's gravity. We obtain from this approach the boundary conditions connecting any two phases within a star and underline its relevance for realistic models of compact stars with phase transitions, owing to the modification of the star's set of eigenmodes with respect to the continuous case

Complementary and alternative approaches used by parents of children with epilepsy on epilepsy management.

Science.gov (United States)

Işler, Ayşegül; Turan, Fatma Dilek; Gözüm, Sebahat; Oncel, Selma

2014-03-01

The aim of this study was to determine the complementary and alternative approaches used by parents of children with epilepsy on epilepsy management. This descriptive study included a total of 304 parents of children with epilepsy aged between 0 and 18years evaluated at the Pediatric Neurology Clinic of Akdeniz University Hospital in Turkey between January and May 2013. Data were collected by using a questionnaire developed by the researchers. It was determined that all the parents use complementary and alternative approaches for their children with epilepsy, and the most common approaches are praying (99.3%); keeping their children away from the effects of smoking (79.8%); feeding their children walnuts (79.6%), butter (59.2%), and bone marrow (58.6%); providing their children with good quality sleep (58.6%); and enabling their children to play games (51%). The approaches commonly applied during seizures include praying (96.2%), comforting their children in their arms and showing affection (55.6%), waiting for seizures to finish at home (45.7%), and laying children on their side (41.1%). Of parents, 98% stated that alternative approaches enable them to control their child's seizures, 100% said that alternative approaches have no adverse effect, and 98.4% stated that they will continue to use these approaches. The children's approaches to cope with epilepsy included looking after pets (72.7%), listening to music (70.1%), watching television (64.5%), playing games (55.3%), praying (51%), and spending time with friends (48.7%). Most of the approaches used by parents and children with epilepsy for the management of illness are determined to consist of complementary approaches that may contribute to management of epilepsy. Knowing the approaches of parents and children with epilepsy that could adversely affect disease management is important for educating parents and children to avoid these potentially harmful interventions. Copyright © 2013 Elsevier Inc. All rights

Perceptions about parents' relationship and parenting quality, attachment styles, and young adults' intimate expectations: a cluster analytic approach.

Science.gov (United States)

Einav, Michal

2014-01-01

This study examines the associations between young adults' perceptions of their parents' intimate relationship and the quality of their parenting as predictors of their children's expectations about intimacy in their own future relationships. A sample of 111 young adults completed questionnaires assessing their perceptions regarding their parents' intimate relationship and parenting quality, their own attachment styles, and their own expectations regarding intimate relationships. A correlational analysis revealed a positive link between the parents' relationship and parenting quality, and between parenting quality and expectations about intimacy, which supports the attachment theory. A cluster analysis identified three distinct groups of parental profiles interrelated with attachment styles that had varying effects on their children's expectations about intimacy. These findings emphasize the unique characteristics of parental relations in the family of origin relations, which have an enduring effect on the interpersonal styles of adult children, providing additional support to an integrated, intergenerational approach to family dynamics.

The STAR project: context, objectives and approaches

NARCIS (Netherlands)

Furse, M.; Hering, D.; Moog, O.; Verdonschot, P.F.M.; Johnson, R.K.; Brabec, K.; Gritzalis, K.; Buffagni, A.; Pinto, P.; Friberg, N.; Murray-Bligh, J.; Kokes, J.; Alber, R.; Usseglio-Polatera, P.; Haase, P.; Sweeting, R.; Bis, B.; Szoszkiewicz, K.; Soszka, H.; Springe, G.; Sporka, F.; Krno, I.

2006-01-01

STAR is a European Commission Framework V project (EVK1-CT-2001-00089). The project aim is to provide practical advice and solutions with regard to many of the issues associated with the Water Framework Directive. This paper provides a context for the STAR research programme through a review of the

Parent insights into atypicalities of social approach behaviour in Williams syndrome.

Science.gov (United States)

Lough, E; Rodgers, J; Janes, E; Little, K; Riby, D M

2016-11-01

Individuals with Williams syndrome have been reported to show high levels of social interest and a desire to interact with others irrespective of their familiarity. This high social motivation, when combined with reduced intellectual capacity and a profile of atypical social behaviour, is important in terms of social vulnerability of individuals with the disorder. Therefore, social approach to unfamiliar people and the role of this behaviour within the Williams syndrome (WS) social phenotype warrant further research to inform social skills' intervention design. The current study used parent interviews (n = 21) to probe aspects of social behaviour and interactions with strangers, as well as the impact of such behaviour on the family. Using thematic analysis, it was possible to explore themes that emerged from the interviews, offering qualitatively rich insight into the variability of social approach behaviour in WS. Thematic analysis confirmed a significant desire to interact with strangers as well as a lack of awareness of appropriate social boundaries. However, parental reports about their child's social approach behaviour varied considerably. The within-syndrome variability of the sample was emphasised in parental reports of their child's personality characteristics (e.g. levels of impulsiveness), as well as the level of parental supervision employed. These in-depth parent insights can help target the needs of individuals with WS and emphasise that an individual approach to intervention will be essential because of the heterogeneity of the WS social profile. © 2016 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

Communicating with parents of children with autism about vaccines and complementary and alternative approaches.

Science.gov (United States)

Gupta, Vidya Bhushan

2010-05-01

Despite incontrovertible evidence that vaccines do not cause autism, some parents continue to refuse them and many parents of children with autism seek hope in unproven and potentially harmful complementary and alternative (CAM) approaches. This commentary explores the reasons for such behaviors and proposes that pediatricians may support parents in their pursuit of hope in unproven treatments as long as these are not potentially harmful to the child or prohibitively expensive. While respecting parental autonomy and hope the pediatricians should share with parents their concerns about lack of scientific evidence about CAM and potential for harm by some approaches.

I-Love relations for incompressible stars and realistic stars

Science.gov (United States)

Chan, T. K.; Chan, AtMa P. O.; Leung, P. T.

2015-02-01

In spite of the diversity in the equations of state of nuclear matter, the recently discovered I-Love-Q relations [Yagi and Yunes, Science 341, 365 (2013), 10.1126/science.1236462], which relate the moment of inertia, tidal Love number (deformability), and the spin-induced quadrupole moment of compact stars, hold for various kinds of realistic neutron stars and quark stars. While the physical origin of such universality is still a current issue, the observation that the I-Love-Q relations of incompressible stars can well approximate those of realistic compact stars hints at a new direction to approach the problem. In this paper, by establishing recursive post-Minkowskian expansion for the moment of inertia and the tidal deformability of incompressible stars, we analytically derive the I-Love relation for incompressible stars and show that the so-obtained formula can be used to accurately predict the behavior of realistic compact stars from the Newtonian limit to the maximum mass limit.

Parenting approaches, family functionality, and internet addiction among Hong Kong adolescents.

Science.gov (United States)

Wu, Cynthia Sau Ting; Wong, Ho Ting; Yu, Kin Fai; Fok, Ka Wing; Yeung, Sheung Man; Lam, Cheuk Ho; Liu, Ka Man

2016-08-18

Internet addiction (IA) among adolescents has become a global health problem, and public awareness of it is increasing. Many IA risk factors relate to parents and the family environment. This study examined the relationship between IA and parenting approaches and family functionality. A cross-sectional study was conducted with 2021 secondary students to identify the prevalence of IA and to explore the association between adolescent IA and familial variables, including parents' marital status, family income, family conflict, family functionality, and parenting approaches. The results revealed that 25.3 % of the adolescent respondents exhibited IA, and logistic regression positively predicted the IA of adolescents from divorced families, low-income families, families in which family conflict existed, and severely dysfunctional families. Interestingly, adolescents with restricted Internet use were almost 1.9 times more likely to have IA than those whose use was not restricted. Internet addiction is common among Chinese adolescents in Hong Kong, and family-based prevention strategies should be aligned with the risk factors of IA.

Achieving Population-Level Change Through a System-Contextual Approach to Supporting Competent Parenting.

Science.gov (United States)

Sanders, Matthew R; Burke, Kylie; Prinz, Ronald J; Morawska, Alina

2017-03-01

The quality of parenting children receive affects a diverse range of child and youth outcomes. Addressing the quality of parenting on a broad scale is a critical part of producing a more nurturing society. To achieve a meaningful population-level reduction in the prevalence rates of child maltreatment and social and emotional problems that are directly or indirectly influenced by parenting practices requires the adoption of a broad ecological perspective in supporting families to raise children. We make the case for adopting a multilevel, whole of population approach to enhance competent parenting and describe the essential tasks that must be accomplished for the approach to be successful and its effects measurable. We describe how a theoretically integrated system of parenting support based on social learning and cognitive behavioral principles can be further strengthened when the broader community supports parental participation. Implications for policy and practice are discussed.

Parent Stars of Extrasolar Planets - XIV. Strong Evidence of Li Abundance Deficit

OpenAIRE

Gonzalez, Guillermo

2014-01-01

We report the results of our analysis of new high resolution spectra of 30 late-F to early-G dwarf field stars for the purpose of deriving their Li abundances. They were selected from the subsample of stars in the Valenti and Fischer compilation that are lacking detected planets. These new data serve to expand our comparison sample used to test whether stars with Doppler-detected giant planets display Li abundance anomalies. Our results continue to show that Li is deficient among stars with p...

Helping Parents Cope with Suicide Threats: An Approach Based on Nonviolent Resistance.

Science.gov (United States)

Omer, Haim; Dolberger, Dan Isaac

2015-09-01

Parent training in nonviolent resistance was adapted to deal with situations of suicide threat by children, adolescents, and young adults. The approach aims at reducing the risk potential and the mutual distress surrounding the threat-interaction. Parent training in nonviolent resistance has been shown to help parents move from helplessness to presence, from isolation to connectedness, from submission to resistance, from escalation to self-control, and from mutual distancing and hostility to care and support. Those emphases can be crucial for the diminution of suicide risk. Parents show good ability to implement the approach and report gains on various areas over and beyond the reduction in suicide threat. A particular advantage is that the method can be used also in cases where the young person threatening suicide is not willing to cooperate. © 2015 Family Process Institute.

A Play Therapy Approach Focusing on Parent-Child Relationship: Filial Therapy

Directory of Open Access Journals (Sweden)

Banu Tortamis Ozkaya

2015-06-01

Full Text Available Filial therapy is a structured, short-term, and evidence-based play therapy model that aims to train and supervise parents in conducting child-centered play therapy sessions with their children. Filial therapy strengthens the relationship among all family members -in particular the relationship between the parent and the child- and helps parents acquire new and effective parenting skills. Thus parents gain a powerful tool to cope with the difficulties they experience even after therapy sessions end. In this review, filial therapy is explained within the context of its theoretical background and therapy process. Several adaptations of the model and research studies on its effectiveness are also discussed briefly. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2015; 7(2: 208-220

Star Masses and Star-Planet Distances for Earth-like Habitability.

Science.gov (United States)

Waltham, David

2017-01-01

This paper presents statistical estimates for the location and duration of habitable zones (HZs) around stars of different mass. The approach is based upon the assumption that Earth's location, and the Sun's mass, should not be highly atypical of inhabited planets. The results support climate-model-based estimates for the location of the Sun's HZ except models giving a present-day outer-edge beyond 1.64 AU. The statistical approach also demonstrates that there is a habitability issue for stars smaller than 0.65 solar masses since, otherwise, Earth would be an extremely atypical inhabited world. It is difficult to remove this anomaly using the assumption that poor habitability of planets orbiting low-mass stars results from unfavorable radiation regimes either before, or after, their stars enter the main sequence. However, the anomaly is well explained if poor habitability results from tidal locking of planets in the HZs of small stars. The expected host-star mass for planets with intelligent life then has a 95% confidence range of 0.78 M ⊙ planets with at least simple life is 0.57 M ⊙  < M < 1.64 M ⊙ . Key Words: Habitability-Habitable zone-Anthropic-Red dwarfs-Initial mass function. Astrobiology 17, 61-77.

Understand B-type stars

Science.gov (United States)

1982-01-01

When observations of B stars made from space are added to observations made from the ground and the total body of observational information is confronted with theoretical expectations about B stars, it is clear that nonthermal phenomena occur in the atmospheres of B stars. The nature of these phenomena and what they imply about the physical state of a B star and how a B star evolves are examined using knowledge of the spectrum of a B star as a key to obtaining an understanding of what a B star is like. Three approaches to modeling stellar structure (atmospheres) are considered, the characteristic properties of a mantle, and B stars and evolution are discussed.

Discovery of a New Wolf-Rayet Star Using SAGE-LMC

Science.gov (United States)

Gvaramadze, V. V.; Chené, A.-N.; Kniazev, A. Y.; Schnurr, O.

2012-12-01

We report the first-ever discovery of an extragalactic Wolf-Rayet (WR) star with Spitzer. A new WR star in the Large Magellanic Cloud (LMC) was revealed via detection of its circumstellar shell using 24 μm images obtained in the framework of the Spitzer Survey of the Large Magellanic Cloud (SAGE-LMC). Subsequent spectroscopic observations with the Gemini South resolved the central star in two components, one of which is a WN3b+abs star, while the second one is a B0 V star. We consider the lopsided brightness distribution over the circumstellar shell as an indication that the WR star is a runaway and use this interpretation to identify a possible parent cluster of the star.

Influence of a Parent-Child Interaction Focused Bookmaking Approach on Maternal Parenting Self-Efficacy

Science.gov (United States)

Boyce, Lisa K.; Seedall, Ryan B.; Innocenti, Mark S.; Roggman, Lori A.; Cook, Gina A.; Hagman, Amanda M.; Jump Norman, Vonda K.

2017-01-01

We examined the effects of our parent-child interaction focused bookmaking intervention with 89 families and their toddlers receiving early intervention services. Participating early intervention providers (N = 24) were assigned to either continue providing services as usual or participate in training to implement the bookmaking approach in their…

Factors Associated with Successful Mentoring of Parents Addressing Childhood Obesity: A Mixed Methods Approach

Directory of Open Access Journals (Sweden)

Gabriela Abigail Villanueva

2016-01-01

Full Text Available Objective. Parents mentoring other parents as a behavioral intervention for child obesity is novel with limited data describing the experience and dynamics of this approach. This study aimed to describe the experiences of parent mentors and the self-efficacy and attitudes of their mentees in the context of a clinical trial for childhood obesity. Methods. The context for this study was a randomized clinical trial using either parent mentors or a community health worker engaging parents of obese children in behavioral change over six months. Parent mentors were interviewed at the mid-point of the intervention using a semistructured questionnaire to elicit their perceptions and experiences during the process of mentoring. Parent mentees completed a survey assessing their self-efficacy, perception of the parent mentor, and attitudes and beliefs related to their child’s weight. Results. The qualitative analysis of parent mentor interviews indicated high commitment despite their nonprofessional status, facing challenges of engagement with fellow parents and attitudes of persistence and being nonjudgmental. The parent mentee ratings of parent mentors were overall very high and similar to the ratings of a community health worker (paraprofessional. Conclusion. The data suggest that a parent mentor model of intervention for child obesity is an acceptable mode of approaching behavior change in the Hispanic population around childhood obesity with potential for scalability if proven effective.

Parent-child Communication-centered Rehabilitative Approach for Pediatric Functional Somatic Symptoms.

Science.gov (United States)

Gerner, Maya; Barak, Sharon; Landa, Jana; Eisenstein, Etzyona

2016-01-01

Functional somatic symptoms (FSS) are a type of somatization phenomenon. Integrative rehabilitation approaches are the preferred treatment for pediatric FSS. Parental roles in the treatment process have not been established. to present 1) a parent-focused treatment (PFT) for pediatric FSS and 2) the approach's preliminary results. The sample included 50 children with physical disabilities due to FSS. All children received PFT including physical and psychological therapy. A detailed description of the program's course and guiding principles is provided. FSS extinction and age-appropriate functioning. Post-program, 84% of participants did not exhibit FSS and 94% returned to age-appropriate functioning. At one-year follow-up, only 5% of participants experienced symptom recurrence. No associations were found between pre-admission symptoms and intervention duration. PFT is beneficial in treating pediatric FSS. Therefore, intensive parental involvement in rehabilitation may be cardinal.

Stability of boson stars

International Nuclear Information System (INIS)

Gleiser, M.

1988-01-01

Boson stars are gravitationally bound, spherically symmetric equilibrium configurations of cold, free, or interacting complex scalar fields phi. As these equilibrium configurations naturally present local anisotropy, it is sensible to expect departures from the well-known stability criteria for fluid stars. With this in mind, I investigate the dynamical instability of boson stars against charge-conserving, small radial perturbations. Following the method developed by Chandrasekhar, a variational base for determining the eigenfrequencies of the perturbations is found. This approach allows one to find numerically an upper bound for the central density where dynamical instability occurs. As applications of the formalism, I study the stability of equilibrium configurations obtained both for the free and for the self-interacting [with V(phi) = (λ/4)chemical bondphichemical bond 4 ] massive scalar field phi. Instabilities are found to occur not for the critical central density as in fluid stars but for central densities considerably higher. The departure from the results for fluid stars is sensitive to the coupling λ; the higher the value of λ, the more the stability properties of boson stars approach those of a fluid star. These results are linked to the fractional anisotropy at the radius of the configuration

A hybrid ensemble learning approach to star-galaxy classification

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Kim, Edward J.; Brunner, Robert J.; Carrasco Kind, Matias

2015-10-01

There exist a variety of star-galaxy classification techniques, each with their own strengths and weaknesses. In this paper, we present a novel meta-classification framework that combines and fully exploits different techniques to produce a more robust star-galaxy classification. To demonstrate this hybrid, ensemble approach, we combine a purely morphological classifier, a supervised machine learning method based on random forest, an unsupervised machine learning method based on self-organizing maps, and a hierarchical Bayesian template-fitting method. Using data from the CFHTLenS survey (Canada-France-Hawaii Telescope Lensing Survey), we consider different scenarios: when a high-quality training set is available with spectroscopic labels from DEEP2 (Deep Extragalactic Evolutionary Probe Phase 2 ), SDSS (Sloan Digital Sky Survey), VIPERS (VIMOS Public Extragalactic Redshift Survey), and VVDS (VIMOS VLT Deep Survey), and when the demographics of sources in a low-quality training set do not match the demographics of objects in the test data set. We demonstrate that our Bayesian combination technique improves the overall performance over any individual classification method in these scenarios. Thus, strategies that combine the predictions of different classifiers may prove to be optimal in currently ongoing and forthcoming photometric surveys, such as the Dark Energy Survey and the Large Synoptic Survey Telescope.

Rates of star formation

International Nuclear Information System (INIS)

Larson, R.B.

1977-01-01

It is illustrated that a theoretical understanding of the formation and evolution of galaxies depends on an understanding of star formation, and especially of the factors influencing the rate of star formation. Some of the theoretical problems of star formation in galaxies, some approaches that have been considered in models of galaxy evolution, and some possible observational tests that may help to clarify which processes or models are most relevant are reviewed. The material is presented under the following headings: power-law models for star formation, star formation processes (conditions required, ways of achieving these conditions), observational indications and tests, and measures of star formation rates in galaxies. 49 references

Design and application of star map simulation system for star sensors

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Wu, Feng; Shen, Weimin; Zhu, Xifang; Chen, Yuheng; Xu, Qinquan

2013-12-01

Modern star sensors are powerful to measure attitude automatically which assure a perfect performance of spacecrafts. They achieve very accurate attitudes by applying algorithms to process star maps obtained by the star camera mounted on them. Therefore, star maps play an important role in designing star cameras and developing procession algorithms. Furthermore, star maps supply significant supports to exam the performance of star sensors completely before their launch. However, it is not always convenient to supply abundant star maps by taking pictures of the sky. Thus, star map simulation with the aid of computer attracts a lot of interests by virtue of its low price and good convenience. A method to simulate star maps by programming and extending the function of the optical design program ZEMAX is proposed. The star map simulation system is established. Firstly, based on analyzing the working procedures of star sensors to measure attitudes and the basic method to design optical system by ZEMAX, the principle of simulating star sensor imaging is given out in detail. The theory about adding false stars and noises, and outputting maps is discussed and the corresponding approaches are proposed. Then, by external programming, the star map simulation program is designed and produced. Its user interference and operation are introduced. Applications of star map simulation method in evaluating optical system, star image extraction algorithm and star identification algorithm, and calibrating system errors are presented completely. It was proved that the proposed simulation method provides magnificent supports to the study on star sensors, and improves the performance of star sensors efficiently.

New York: Les ecoles entre SURR et STAR (New York: Schools between SURR and STAR).

Science.gov (United States)

Ueberschlag, Roger

1994-01-01

Three problems of New York City (New York) schools--overpopulation, low academic standards, violence--are examined, and an effort led by parent and teacher organizations to improve conditions is described. Threatened closings (schools under registration review, SURR) and a program of violence reduction (Straight Talk about Risks, STAR) are noted.…

Parent Communication Prompt to Increase Shared Decision-Making: A New Intervention Approach

Directory of Open Access Journals (Sweden)

Lauren M. Hubner

2018-03-01

intervention group.ConclusionsParent and clinician enrollment and data collection with minimal loss suggest that this novel approach is easy to use and could be employed in future outpatient studies exploring SDM. In this clinical setting, both intervention and comparison group parents reported high levels of SDM participation and no main group effect was detected. Further study of this novel parent-directed SDM intervention approach is needed in a larger sample with greater variability in parent-reported SDM to determine its efficacy.

55 CANCRI: A COPLANAR PLANETARY SYSTEM THAT IS LIKELY MISALIGNED WITH ITS STAR

International Nuclear Information System (INIS)

Kaib, Nathan A.; Duncan, Martin J.; Raymond, Sean N.

2011-01-01

Although the 55 Cnc system contains multiple, closely packed planets that are presumably in a coplanar configuration, we use numerical simulations to demonstrate that they are likely to be highly inclined to their parent star's spin axis. Due to perturbations from its distant binary companion, this planetary system precesses like a rigid body about its parent star. Consequently, the parent star's spin axis and the planetary orbit normal likely diverged long ago. Because only the projected separation of the binary is known, we study this effect statistically, assuming an isotropic distribution for wide binary orbits. We find that the most likely projected spin-orbit angle is ∼50°, with a ∼30% chance of a retrograde configuration. Transit observations of the innermost planet—55 Cnc e—may be used to verify these findings via the Rossiter-McLaughlin effect. 55 Cancri may thus represent a new class of planetary systems with well-ordered, coplanar orbits that are inclined with respect to the stellar equator.

OUTCOMES AND DURATION OF TIDAL EVOLUTION IN A STAR-PLANET-MOON SYSTEM

International Nuclear Information System (INIS)

Sasaki, Takashi; Barnes, Jason W.; O'Brien, David P.

2012-01-01

We formulated tidal decay lifetimes for hypothetical moons orbiting extrasolar planets with both lunar and stellar tides. Previous works neglected the effect of lunar tides on planet rotation, and are therefore applicable only to systems in which the moon's mass is much less than that of the planet. This work, in contrast, can be applied to the relatively large moons that might be detected around newly discovered Neptune-mass and super-Earth planets. We conclude that moons are more stable when the planet/moon systems are further from the parent star, the planets are heavier, or the parent stars are lighter. Inclusion of lunar tides allows for significantly longer lifetimes for a massive moon relative to prior formulations. We expect that the semimajor axis of the planet hosting the first detected exomoon around a G-type star is 0.4-0.6 AU and is 0.2-0.4 AU for an M-type star.

Successful approaches. Sports stars and HEAPS.

Science.gov (United States)

1996-01-01

In western Samoa, football stars are being used in the fight against acquired immunodeficiency syndrome (AIDS). Originally recruited by Palanitina Toelupe, chief health educator of the Health Education and Promotion Section (HEAPS), to assist with an anti-smoking campaign, the players became sensitized to issues regarding AIDS and agreed to visit high schools where they could urge young people to "Learn the Facts (about AIDS) and Pass the Word." With assistance from the SPC, HEAPS produced and broadcast radio and TV spots featuring the athletes; a poster was printed and distributed. Sports stars travel regionally and internationally; those with knowledge of AIDS and unsafe sex behavior can reinforce responsible sexual behavior among their teammates. Sports people should be targeted for AIDS and sexually transmitted disease (STD) education and prevention.

Approaches used by parents to keep their children safe at home: a qualitative study to explore the perspectives of parents with children aged under five years.

Science.gov (United States)

Ablewhite, Joanne; McDaid, Lisa; Hawkins, Adrian; Peel, Isabel; Goodenough, Trudy; Deave, Toity; Stewart, Jane; Watson, Michael; Kendrick, Denise

2015-09-29

Childhood unintentional injury represents an important global health problem. Many unintentional injuries experienced by children aged under 5 years occur within the home and are preventable. The aim of this study was to explore the approaches used by parents of children under five in order to help prevent unintentional injuries in the home and the factors which influence their use. Understanding how parents approach risk-management in the home has important implications for injury practitioners. A multi-centre qualitative study using semi-structured interviews. A thematic approach was used to analyse the data. Sixty five parents of children aged under 5 years, from four study areas were interviewed: Bristol, Newcastle, Norwich and Nottingham. Three main injury prevention strategies used by parents were: a) Environmental such as removal of hazards, and use of safety equipment; b) parental supervision; and c) teaching, for example, teaching children about safety and use of rules and routine. Strategies were often used in combination due to their individual limitations. Parental assessment of injury risk, use of strategy and perceived effectiveness were fluid processes dependent on a child's character, developmental age and the prior experiences of both parent and child. Some parents were more proactive in their approach to home safety while others only reacted if their child demonstrated an interest in a particular object or activity perceived as being an injury risk. Parents' injury prevention practices encompass a range of strategies that are fluid in line with the child's age and stage of development; however, parents report that they still find it challenging to decide which strategy to use and when.

Modeling jet and outflow feedback during star cluster formation

Energy Technology Data Exchange (ETDEWEB)

Federrath, Christoph [Monash Centre for Astrophysics, School of Mathematical Sciences, Monash University, VIC 3800 (Australia); Schrön, Martin [Department of Computational Hydrosystems, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, D-04318 Leipzig (Germany); Banerjee, Robi [Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg (Germany); Klessen, Ralf S., E-mail: christoph.federrath@monash.edu [Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Ueberle-Strasse 2, D-69120 Heidelberg (Germany)

2014-08-01

Powerful jets and outflows are launched from the protostellar disks around newborn stars. These outflows carry enough mass and momentum to transform the structure of their parent molecular cloud and to potentially control star formation itself. Despite their importance, we have not been able to fully quantify the impact of jets and outflows during the formation of a star cluster. The main problem lies in limited computing power. We would have to resolve the magnetic jet-launching mechanism close to the protostar and at the same time follow the evolution of a parsec-size cloud for a million years. Current computer power and codes fall orders of magnitude short of achieving this. In order to overcome this problem, we implement a subgrid-scale (SGS) model for launching jets and outflows, which demonstrably converges and reproduces the mass, linear and angular momentum transfer, and the speed of real jets, with ∼1000 times lower resolution than would be required without the SGS model. We apply the new SGS model to turbulent, magnetized star cluster formation and show that jets and outflows (1) eject about one-fourth of their parent molecular clump in high-speed jets, quickly reaching distances of more than a parsec, (2) reduce the star formation rate by about a factor of two, and (3) lead to the formation of ∼1.5 times as many stars compared to the no-outflow case. Most importantly, we find that jets and outflows reduce the average star mass by a factor of ∼ three and may thus be essential for understanding the characteristic mass of the stellar initial mass function.

The parent-child-therapist alliance: A case study using a strategic approach.

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Naidu, Thirusha; Behari, Sheethal

2010-06-01

In this paper we present a single case study of a clinical approach that addresses the needs of parents and their children in psychotherapy. The approach begins by addressing the child's and parent's concerns separately at first by establishing strong therapeutic alliances with each, and then proceeds to address the concerns of the parent-child dyad. The basic premise is that the therapeutic alliance is the central element to successful outcomes in psychotherapy. The nature of alliance-building and its associated methods and techniques have been extensively considered for adult therapy. However, there is considerably less written on the therapeutic alliance with children and adolescents in the context of family interventions. We briefly examine some theoretical dimensions and applications of the therapeutic alliance in psychotherapy with children/adolescents and their parents. A three-phase alliance-building psychotherapy strategy, founded on the idea that each therapeutic relationship warrants an effective working alliance, is proposed. The case of a single mother and her adolescent daughter is employed to illustrate the strategy.

Capturing Parenting as a Multidimensional and Dynamic Construct with a Person-Oriented Approach.

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Zheng, Yao; Pasalich, Dave S; Oberth, Carla; McMahon, Robert J; Pinderhughes, Ellen E

2017-04-01

Although parenting is one of the most commonly studied predictors of child problem behavior, few studies have examined parenting as a multidimensional and dynamic construct. This study investigated different patterns of developmental trajectories of two parenting dimensions (harsh discipline [HD] and parental warmth [PW]) with a person-oriented approach and examined the associations between different parenting patterns and child externalizing problems and callous-unemotional traits. Data were drawn from the combined high-risk control and normative sample (n = 753) of the Fast Track Project. Parent-reported HD and observer-reported PW from kindergarten to grade 2 were fit to growth mixture models. Two subgroups were identified for HD (low decreasing, 83.0 %; high stable, 17.0 %) and PW (high increasing, 78.7 %; low increasing, 21.3 %). The majority of parents (67.0 %) demonstrated the low decreasing HD and high increasing PW pattern, while the prevalence of the high stable HD and low increasing PW pattern was the lowest (6.8 %). Parenting satisfaction, parental depression, family socioeconomic status, and neighborhood safety predicted group memberships jointly defined by the two dimensions. Children from the high stable HD and low increasing PW pattern showed the highest levels of externalizing problems in grades 4 and 5. Children from the low decreasing HD and low increasing PW pattern showed the highest levels of callous-unemotional traits in grade 7. These findings demonstrate the utility and significance of a person-oriented approach to measuring parenting as a multidimensional and dynamic construct and reveal the interplay between HD and PW in terms of their influences on child developmental outcomes.

Students, Parents, Educators: An Approach to Conflict of Rights.

Science.gov (United States)

Magsino, Romulo F.

1982-01-01

Attempts by courts in the United States and Canada to define the rights of children, parents, and educators are described, and their shortcomings and contradictions are pointed out. The author suggests another approach based on utilitarian values and pre-suppositions presented in works by John Stuart Mill. (PP)

Phosphorus Chemistry in Oxygen Rich Stars

Science.gov (United States)

Bernal, Jacob; Schmidt, Deborah; Anderson, Julie; Ziurys, Lucy M.

2017-06-01

Observations of PO and PN have been carried out at the Arizona Radio Observatory at 1, 2, and 3 mm. Multiple transitions of PO and PN have been detected towards the O-rich AGB stars TX Cam and RCas. Data obtained toward supergiant stars VY Canis Majoris and NML Cyg have also been analyzed. Abundances were obtained for these molecules in all four objects using the radiative transfer code ESCAPADE, which is suitable for symmetric and asymmetric stellar outflows. The abundances of PN and PO were found to be in the range 10^{-8} - 10^{-7} relative to H_{2}. While PN appears to be a parent molecule formed by LTE chemistry near the stellar photosphere, PO appears to be created further out from the star at r > 400 R_*.

Massive runaway stars in the Small Magellanic Cloud

Science.gov (United States)

Gvaramadze, V. V.; Pflamm-Altenburg, J.; Kroupa, P.

2011-01-01

Using archival Spitzer Space Telescope data, we identified for the first time a dozen runaway OB stars in the Small Magellanic Cloud (SMC) through the detection of their bow shocks. The geometry of detected bow shocks allows us to infer the direction of motion of the associated stars and to determine their possible parent clusters and associations. One of the identified runaway stars, AzV 471, was already known as a high-velocity star on the basis of its high peculiar radial velocity, which is offset by ≃ 40 km s-1 from the local systemic velocity. We discuss implications of our findings for the problem of the origin of field OB stars. Several of the bow shock-producing stars are found in the confines of associations, suggesting that these may be “alien” stars contributing to the age spread observed for some young stellar systems. We also report the discovery of a kidney-shaped nebula attached to the early WN-type star SMC-WR3 (AzV 60a). We interpreted this nebula as an interstellar structure created owing to the interaction between the stellar wind and the ambient interstellar medium.

A review of the nurtured heart approach to parenting: evaluation of its theoretical and empirical foundations.

Science.gov (United States)

Hektner, Joel M; Brennan, Alison L; Brotherson, Sean E

2013-09-01

The Nurtured Heart Approach to parenting (NHA; Glasser & Easley, 2008) is summarized and evaluated in terms of its alignment with current theoretical perspectives and empirical evidence in family studies and developmental science. Originally conceived and promoted as a behavior management approach for parents of difficult children (i.e., with behavior disorders), NHA is increasingly offered as a valuable strategy for parents of any children, despite a lack of published empirical support. Parents using NHA are trained to minimize attention to undesired behaviors, provide positive attention and praise for compliance with rules, help children be successful by scaffolding and shaping desired behavior, and establish a set of clear rules and consequences. Many elements of the approach have strong support in the theoretical and empirical literature; however, some of the assumptions are more questionable, such as that negative child behavior can always be attributed to unintentional positive reinforcement by parents responding with negative attention. On balance, NHA appears to promote effective and validated parenting practices, but its effectiveness now needs to be tested empirically. © FPI, Inc.

DRIVING TURBULENCE AND TRIGGERING STAR FORMATION BY IONIZING RADIATION

International Nuclear Information System (INIS)

Gritschneder, Matthias; Naab, Thorsten; Walch, Stefanie; Burkert, Andreas; Heitsch, Fabian

2009-01-01

We present high-resolution simulations on the impact of ionizing radiation of massive O stars on the surrounding turbulent interstellar medium (ISM). The simulations are performed with the newly developed software iVINE which combines ionization with smoothed particle hydrodynamics (SPH) and gravitational forces. We show that radiation from hot stars penetrates the ISM, efficiently heats cold low-density gas and amplifies overdensities seeded by the initial turbulence. The formation of observed pillar-like structures in star-forming regions (e.g. in M16) can be explained by this scenario. At the tip of the pillars gravitational collapse can be induced, eventually leading to the formation of low-mass stars. Detailed analysis of the evolution of the turbulence spectra shows that UV radiation of O stars indeed provides an excellent mechanism to sustain and even drive turbulence in the parental molecular cloud.

Motion-blurred star acquisition method of the star tracker under high dynamic conditions.

Science.gov (United States)

Sun, Ting; Xing, Fei; You, Zheng; Wei, Minsong

2013-08-26

The star tracker is one of the most promising attitude measurement devices used in spacecraft due to its extremely high accuracy. However, high dynamic performance is still one of its constraints. Smearing appears, making it more difficult to distinguish the energy dispersive star point from the noise. An effective star acquisition approach for motion-blurred star image is proposed in this work. The correlation filter and mathematical morphology algorithm is combined to enhance the signal energy and evaluate slowly varying background noise. The star point can be separated from most types of noise in this manner, making extraction and recognition easier. Partial image differentiation is then utilized to obtain the motion parameters from only one image of the star tracker based on the above process. Considering the motion model, the reference window is adopted to perform centroid determination. Star acquisition results of real on-orbit star images and laboratory validation experiments demonstrate that the method described in this work is effective and the dynamic performance of the star tracker could be improved along with more identified stars and guaranteed position accuracy of the star point.

Relationships among Taiwanese Children's Computer Game Use, Academic Achievement and Parental Governing Approach

Science.gov (United States)

Yeh, Duen-Yian; Cheng, Ching-Hsue

2016-01-01

This study examined the relationships among children's computer game use, academic achievement and parental governing approach to propose probable answers for the doubts of Taiwanese parents. 355 children (ages 11-14) were randomly sampled from 20 elementary schools in a typically urbanised county in Taiwan. Questionnaire survey (five questions)…

The impact of front-of-pack marketing attributes versus nutrition and health information on parents' food choices.

Science.gov (United States)

Georgina Russell, Catherine; Burke, Paul F; Waller, David S; Wei, Edward

2017-09-01

Front-of-pack attributes have the potential to affect parents' food choices on behalf of their children and form one avenue through which strategies to address the obesogenic environment can be developed. Previous work has focused on the isolated effects of nutrition and health information (e.g. labeling systems, health claims), and how parents trade off this information against co-occurring marketing features (e.g. product imagery, cartoons) is unclear. A Discrete Choice Experiment was utilized to understand how front-of-pack nutrition, health and marketing attributes, as well as pricing, influenced parents' choices of cereal for their child. Packages varied with respect to the two elements of the Australian Health Star Rating system (stars and nutrient facts panel), along with written claims, product visuals, additional visuals, and price. A total of 520 parents (53% male) with a child aged between five and eleven years were recruited via an online panel company and completed the survey. Product visuals, followed by star ratings, were found to be the most significant attributes in driving choice, while written claims and other visuals were the least significant. Use of the Health Star Rating (HSR) system and other features were related to the child's fussiness level and parents' concerns about their child's weight with parents of fussy children, in particular, being less influenced by the HSR star information and price. The findings suggest that front-of-pack health labeling systems can affect choice when parents trade this information off against marketing attributes, yet some marketing attributes can be more influential, and not all parents utilize this information in the same way. Copyright © 2017. Published by Elsevier Ltd.

Parents' experiences of being in the Solihull Approach parenting group, 'Understanding Your Child's Behaviour': an interpretative phenomenological analysis.

Science.gov (United States)

Vella, L R; Butterworth, R E; Johnson, R; Law, G Urquhart

2015-11-01

Empirical evidence suggests that the Solihull Approach parenting group, 'Understanding Your Child's Behaviour' (UYCB), can improve child behaviour and parental well-being. However, little is known about parents' in-depth experience of participating in the UYCB programme. This study provides an in-depth qualitative evaluation of UYCB, focussing on possible moderating factors and mechanisms of change that may inform programme development. Ten parents (eight mothers and two fathers), recruited from seven UYCB groups across two locations, were interviewed within 7 weeks of completing the group and again 10 months later. Data were analysed using interpretative phenomenological analysis. Four themes were identified: 'Two Tiers of Satisfaction', 'Development as a Parent', 'Improved Self-belief' and 'The "Matthew Effect"'. In summary, the majority of parents were immensely satisfied at both completion and follow-up: they valued an experience of containment and social support and perceived improvement in specific child difficulties, their experience of parenting, their confidence and their coping. Most parents appeared to have developed more reflective and empathic parenting styles, with self-reported improved behaviour management. Theoretical material was well received, although some struggled with technical language. Positive outcomes appeared to be maintained, even reinforced, at follow-up, and were associated with having few initial child difficulties, perceiving improvement at completion and persevering with the recommendations. Two participants, whose children had the most severe difficulties, perceived deterioration and felt that the group was insufficient for their level of difficulties. Through in-depth analysis of parental experiences, UYCB appears to achieve its aims and communicate well its theoretical principles, although change may also occur through processes common to other group programmes (e.g. social support). Recommendations, stemming from the

A Person-Centered Approach to Studying the Linkages among Parent-Child Differences in Cultural Orientation, Supportive Parenting, and Adolescent Depressive Symptoms in Chinese American Families

Science.gov (United States)

Weaver, Scott R.; Kim, Su Yeong

2008-01-01

This longitudinal study examined whether supportive parenting mediates relations between parent-child differences in cultural orientation (generational dissonance) and depressive symptoms with a sample of 451 first and second generation Chinese American parents and adolescents (12-15 years old at time 1). Using a person-centered approach,…

Parent-only vs. parent-child (family-focused) approaches for weight loss in obese and overweight children: a systematic review and meta-analysis.

Science.gov (United States)

Jull, A; Chen, R

2013-09-01

Families are recommended as the agents of change for weight loss in overweight and obese children; family approaches are more effective than those that focus on the child alone. However, interventions that focus on parents alone have not been summarized. The objective of this review was to assess the effectiveness of interventions that compared a parent-only (PO) condition with a parent-child (PC) condition. Four trials using a similar between-group background approaches to overweight and obese children's weight loss met the inclusion criteria, but only one trial reported sufficient data for meta-analysis. Further information was obtained from authors. Meta-analysis showed no significant difference in z-BMI from baseline to end of treatment between the conditions (three trials) or to end of follow up (two trials). The trials were at risk of bias and no single trial was at lower risk of bias than others. There is an absence of high quality evidence regarding the effect of parent-only interventions for weight loss in children compared to parent-child interventions, but current evidence suggests the need for further investigation. © 2013 The Authors. obesity reviews © 2013 International Association for the Study of Obesity.

Negative (but not Positive) Parenting Interacts with Infant Negative Affect to Predict Infant Approach: Evidence of Diathesis-Stress.

Science.gov (United States)

Holzman, Jacob B; Burt, Nicole M; Edwards, Erin S; Rosinski, Leanna D; Bridgett, David J

2018-01-01

Temperament by parenting interactions may reflect that individuals with greater risk are more likely to experience negative outcomes in adverse contexts (diathesis-stress) or that these individuals are more susceptible to contextual influences in a 'for better or for worse' pattern (differential susceptibility). Although such interactions have been identified for a variety of child outcomes, prior research has not examined approach characteristics - excitement and approach toward pleasurable activities - in the first year of life. Therefore, the current study investigated whether 6-month maternal reported infant negative affect - a phenotypic marker of risk/susceptibility - interacted with 8-month observed parenting behaviors (positive parenting, negative parenting) to predict 12-month infant behavioral approach. Based a sample of mothers and their infants ( N =150), results indicated that negative parenting was inversely associated with subsequent approach for infants with high, but not low, levels of early negative affect. Similar results did not occur regarding positive parenting. These findings better fit a diathesis-stress model rather than a differential susceptibility model. Implications and limitations of these findings are discussed.

A Synthesis of Behavioral and Communication Approaches to Child Rearing for Parenting Skills Classes. Practicum II.

Science.gov (United States)

Silverman, Marvin

This report describes the design, implementation and evaluation of a class on effective parenting skills that combined behavioral and communication based (client-centered and Adlerian) approaches to child rearing. Seventeen parents of elementary school age children attended the class; twelve parents attended five or more sessions. The class…

Parental Involvement in the Musical Education of Violin Students: Suzuki and "Traditional" Approaches Compared

Science.gov (United States)

Bugeja, Clare

2009-01-01

This article investigates parental involvement in the musical education of violin students and the changing role of the parents' across the learning process. Two contexts were compared, one emphasising the Suzuki methodology and the other a "traditional" approach. Students learning "traditionally" are typically taught note reading from the…

Cultural distance between parents' and children's creativity: A within-country approach in Taiwan.

Science.gov (United States)

Chang, Jen-Ho; Su, Jenny C; Chen, Hsueh-Chih

2015-07-01

The present study adopted a within-country approach to investigate the relation of cultural distance to general creativity and math creativity in Taiwan. First, we conducted a pilot study of 201 young adolescents with parents from one of the 3 largest subethnic groups in Taiwan, namely Min-nan Taiwanese, Ha-kka Taiwanese, and Outside-Province Taiwanese. The results revealed that young Taiwanese adolescents perceived the cultural distance between Min-nan Taiwanese and Outside-Province Taiwanese as larger than the cultural distance between the other subethnic groups. The main study revealed that 610 young adolescents from large cultural distance families (i.e., those comprising 1 Min-nan Taiwanese parent and 1 Outside-Province Taiwanese parent) outperformed those from small cultural distance families (i.e., those comprising 2 Min-nan Taiwanese parents, and those comprising 1 Min-nan Taiwanese parent and 1 Ha-kka Taiwanese parent) on both general creativity and math creativity. This pattern remained even after controlling for family socioeconomic status, parents' education level, and adolescents' school mathematical performance. Implications and limitations are discussed. (c) 2015 APA, all rights reserved).

Science Through ARts (STAR)

Science.gov (United States)

Kolecki, Joseph; Petersen, Ruth; Williams, Lawrence

2002-01-01

Science Through ARts (STAR) is an educational initiative designed to teach students through a multidisciplinary approach to learning. This presentation describes the STAR pilot project, which will use Mars exploration as the topic to be integrated. Schools from the United Kingdom, Japan, the United States, and possibly eastern Europe are expected to participate in the pilot project.

Hot Jupiters and cool stars

International Nuclear Information System (INIS)

Villaver, Eva; Mustill, Alexander J.; Livio, Mario; Siess, Lionel

2014-01-01

Close-in planets are in jeopardy, as their host stars evolve off the main sequence (MS) to the subgiant and red giant phases. In this paper, we explore the influences of the stellar mass (in the range 1.5-2 M ☉ ), mass-loss prescription, planet mass (from Neptune up to 10 Jupiter masses), and eccentricity on the orbital evolution of planets as their parent stars evolve to become subgiants and red giants. We find that planet engulfment along the red giant branch is not very sensitive to the stellar mass or mass-loss rates adopted in the calculations, but quite sensitive to the planetary mass. The range of initial separations for planet engulfment increases with decreasing mass-loss rates or stellar masses and increasing planetary masses. Regarding the planet's orbital eccentricity, we find that as the star evolves into the red giant phase, stellar tides start to dominate over planetary tides. As a consequence, a transient population of moderately eccentric close-in Jovian planets is created that otherwise would have been expected to be absent from MS stars. We find that very eccentric and distant planets do not experience much eccentricity decay, and that planet engulfment is primarily determined by the pericenter distance and the maximum stellar radius.

Socioeconomic Status, Parenting, and Externalizing Problems in African American Single-Mother Homes: A Person-Oriented Approach

Science.gov (United States)

Anton, Margaret T.; Jones, Deborah J.; Youngstrom, Eric A.

2016-01-01

African American youth, particularly those from single-mother homes, are overrepresented in statistics on externalizing problems. The family is a central context in which to understand externalizing problems; however, reliance on variable-oriented approaches to the study of parenting, which originate from work with intact, middle-income, European American families, may obscure important information regarding variability in parenting styles among African American single mothers, and in turn, variability in youth outcomes as well. The current study demonstrated that within African American single-mother families: (a) a person-, rather than variable-, oriented approach to measuring parenting style may further elucidate variability; (b) socioeconomic status may provide 1 context within which to understanding variability in parenting style; and (c) 1 marker of socioeconomic status, income, and parenting style may each explain variability in youth externalizing problems; however, the interaction between income and parenting style was not significant. Findings have potential implications for better understanding the specific contexts in which externalizing problems may be most likely to occur within this at-risk and underserved group. PMID:26053349

Socioeconomic status, parenting, and externalizing problems in African American single-mother homes: A person-oriented approach.

Science.gov (United States)

Anton, Margaret T; Jones, Deborah J; Youngstrom, Eric A

2015-06-01

African American youth, particularly those from single-mother homes, are overrepresented in statistics on externalizing problems. The family is a central context in which to understand externalizing problems; however, reliance on variable-oriented approaches to the study of parenting, which originate from work with intact, middle-income, European American families, may obscure important information regarding variability in parenting styles among African American single mothers, and in turn, variability in youth outcomes as well. The current study demonstrated that within African American single-mother families: (a) a person-, rather than variable-, oriented approach to measuring parenting style may further elucidate variability; (b) socioeconomic status may provide 1 context within which to understanding variability in parenting style; and (c) 1 marker of socioeconomic status, income, and parenting style may each explain variability in youth externalizing problems; however, the interaction between income and parenting style was not significant. Findings have potential implications for better understanding the specific contexts in which externalizing problems may be most likely to occur within this at-risk and underserved group. (c) 2015 APA, all rights reserved).

Rational Emotive Approaches to the Problems of Parents with Exceptional Children: A Brief Overview.

Science.gov (United States)

McInerney, John F.

Parents of exceptional children face numerous challenges in their efforts to meet the needs of their child. Reaction to the realization that a problem exists in the child's development or educational achievement may lead to emotional distress which can be self-defeating. Such parents often benefit from a direct approach to addressing these issues…

Parent Perspectives on Rehabilitation Services for Their Children with Disabilities: A Mixed Methods Approach

Science.gov (United States)

Schreiber, Joseph; Benger, Jennifer; Salls, Joyce; Marchetti, Gregory; Reed, Lindsey

2011-01-01

Health care providers have adopted a family-centered care (FCC) approach. Parent satisfaction is an indicator of the effectiveness of FCC. The purpose of this project was to describe parent perceptions of the extent to which FCC behaviors occurred in an outpatient pediatric rehabilitation facility. The Measure of Processes of Care (MPOC)-20, a…

Revisiting video game ratings: Shift from content-centric to parent-centric approach

Directory of Open Access Journals (Sweden)

Jiow Hee Jhee

2017-01-01

Full Text Available The rapid adoption of video gaming among children has placed tremendous strain on parents’ ability to manage their children’s consumption. While parents refer online to video games ratings (VGR information to support their mediation efforts, there are many difficulties associated with such practice. This paper explores the popular VGR sites, and highlights the inadequacies of VGRs to capture the parents’ concerns, such as time displacement, social interactions, financial spending and various video game effects, beyond the widespread panics over content issues, that is subjective, ever-changing and irrelevant. As such, this paper argues for a shift from content-centric to a parent-centric approach in VGRs, that captures the evolving nature of video gaming, and support parents, the main users of VGRs, in their management of their young video gaming children. This paper proposes a Video Games Repository for Parents to represent that shift.

Orphan Stars Found in Long Galaxy Tail

Science.gov (United States)

2007-09-01

Astronomers have found evidence that stars have been forming in a long tail of gas that extends well outside its parent galaxy. This discovery suggests that such "orphan" stars may be much more prevalent than previously thought. The comet-like tail was observed in X-ray light with NASA's Chandra X-ray Observatory and in optical light with the Southern Astrophysical Research (SOAR) telescope in Chile. The feature extends for more than 200,000 light years and was created as gas was stripped from a galaxy called ESO 137-001 that is plunging toward the center of Abell 3627, a giant cluster of galaxies. "This is one of the longest tails like this we have ever seen," said Ming Sun of Michigan State University, who led the study. "And, it turns out that this is a giant wake of creation, not of destruction." Chandra X-ray Image of ESO 137-001 and Tail in Abell 3627 Chandra X-ray Image of ESO 137-001 and Tail in Abell 3627 The observations indicate that the gas in the tail has formed millions of stars. Because the large amounts of gas and dust needed to form stars are typically found only within galaxies, astronomers have previously thought it unlikely that large numbers of stars would form outside a galaxy. "This isn't the first time that stars have been seen to form between galaxies," said team member Megan Donahue, also of MSU. "But the number of stars forming here is unprecedented." The evidence for star formation in this tail includes 29 regions of ionized hydrogen glowing in optical light, thought to be from newly formed stars. These regions are all downstream of the galaxy, located in or near the tail. Two Chandra X-ray sources are near these regions, another indication of star formation activity. The researchers believe the orphan stars formed within the last 10 million years or so. The stars in the tail of this fast-moving galaxy, which is some 220 million light years away, would be much more isolated than the vast majority of stars in galaxies. H-alpha Image of

The STAR experiment at RHIC

International Nuclear Information System (INIS)

Marx, J.N.

1994-01-01

STAR (Solenoidal Tracker at RHIC) will be one of two large, sophisticated experiments ready to take data when the Relativistic Heavy Ion Collider (RHIC) comes on-line in 1999. The design of STAR, its construction and commissioning and the physics program using the detector are the responsibility of a collaboration of over 250 members from 30 institutions, world-wide. The overall approach of the STAR Collaboration to the physics challenge of studying collisions of highly relativistic nuclei is to focus on measurements of the properties of the many hadrons produced in the collisions. The STAR detector is optimized to detect and identify hadrons over a large solid angle so that individual events can be characterized, in detail, based on their hadronic content. The broad capabilities of the STAR detector will permit an examination of a wide variety of proposed signatures for the Quark Gluon Plasma (QGP), using the sample of events which, on an event-by-event basis, appear to come from collisions resulting in a large energy density over a nuclear volume. In order to achieve this goal, the STAR experiment is based on a solenoid geometry with tracking detectors using the time projection chamber approach and covering a large range of pseudo-rapidity so that individual tracks can be seen within the very high track density expected in central collisions at RHIC. STAR also uses particle identification by the dE/dx technique and by time-of-flight. Electromagnetic energy is detected in a large, solid-angle calorimeter. The construction of STAR, which will be located in the Wide Angle Hall at the 6 o'clock position at RHIC, formally began in early 1993

Very massive runaway stars from three-body encounters

Science.gov (United States)

Gvaramadze, Vasilii V.; Gualandris, Alessia

2011-01-01

Very massive stars preferentially reside in the cores of their parent clusters and form binary or multiple systems. We study the role of tight very massive binaries in the origin of the field population of very massive stars. We performed numerical simulations of dynamical encounters between single (massive) stars and a very massive binary with parameters similar to those of the most massive known Galactic binaries, WR 20a and NGC 3603-A1. We found that these three-body encounters could be responsible for the origin of high peculiar velocities (≥70 km s-1) observed for some very massive (≥60-70 M⊙) runaway stars in the Milky Way and the Large Magellanic Cloud (e.g. λ Cep, BD+43°3654, Sk -67°22, BI 237, 30 Dor 016), which can hardly be explained within the framework of the binary-supernova scenario. The production of high-velocity massive stars via three-body encounters is accompanied by the recoil of the binary in the opposite direction to the ejected star. We show that the relative position of the very massive binary R145 and the runaway early B-type star Sk-69°206 on the sky is consistent with the possibility that both objects were ejected from the central cluster, R136, of the star-forming region 30 Doradus via the same dynamical event - a three-body encounter.

Counsellor Use of the Adlerian-Dreikurs Approach with Parents in the School Setting.

Science.gov (United States)

Van Hesteren, Frank

1979-01-01

Involvement with parents constitutes an important dimension of the elementary school counselor's role. The Adlerian-Dreikurs approach is described in terms of its underlying theory and the means by which it can be implemented by school counselors. Certain advantages of using the approach in the schools are also discussed. (Author)

Parenting and psychiatric rehabilitation: Can parents with severe mental illness benefit from a new approach? : 1-3 October

NARCIS (Netherlands)

Joanne Nicholson; dr. P.C. van der Ende; Jaap van Weeghel; Dr. Lies Korevaar; Jooske T. van Busschbach

2015-01-01

Can parents with severe mental illness benefit from a new approach? XIthENMESH International Conference in Málaga (Spain). 1-3 October, 2015. With these results at hand we developed a new program and evaluated it . In this presentation we will reflect on the merits of this program but also share

Nuclear processing during star formation

International Nuclear Information System (INIS)

Newman, M.J.

1978-01-01

A preliminary survey was conducted of the thermonuclear energy release expected during star formation. The destruction of primordial deuterium provides substantial amounts of energy at surprisingly low temperatures, and must be considered in any meaningful treatment of star formation carried to stages in which the internal temperature exceeds a few hundred thousand degrees. Significant energy generation from consumption of initial lithium requires higher temperatures, of the order of a few million degrees. Depletion of primordial beryllium and boron may never provide an important energy source. The approach to equilibrium of the carbon--nitrogen cycle is dominant at temperatures approaching those characteristic of the central regions of main sequence stars. The present calculation should serve as a useful guide in choosing those nuclear processes to be included in a more detailed study. 8 figures, 2 tables

Terminal velocities for a large sample of O stars, B supergiants, and Wolf-Rayet stars

International Nuclear Information System (INIS)

Prinja, R.K.; Barlow, M.J.; Howarth, I.D.

1990-01-01

It is argued that easily measured, reliable estimates of terminal velocities for early-type stars are provided by the central velocity asymptotically approached by narrow absorption features and by the violet limit of zero residual intensity in saturated P Cygni profiles. These estimators are used to determine terminal velocities, v(infinity), for 181 O stars, 70 early B supergiants, and 35 Wolf-Rayet stars. For OB stars, the values are typically 15-20 percent smaller than the extreme violet edge velocities, v(edge), while for WR stars v(infinity) = 0.76 v(edge) on average. New mass-loss rates for WR stars which are thermal radio emitters are given, taking into account the new terminal velocities and recent revisions to estimates of distances and to the mean nuclear mass per electron. The relationships between v(infinity), the surface escape velocities, and effective temperatures are examined. 67 refs

Nearby stars of the Galactic disc and halo - IV

Science.gov (United States)

Fuhrmann, Klaus

2008-02-01

The Milky Way Galaxy has an age of about 13 billion years. Solar-type stars evolve all the long way to the realm of degenerate objects on essentially this time-scale. This, as well as the particular advantage that the Sun offers through reliable differential spectroscopic analyses, render these stars the ideal tracers for the fossil record of our parent spiral. Astrophysics is a science that is known to be notoriously plagued by selection effects. The present work - with a major focus in this fourth contribution on model atmosphere analyses of spectroscopic binaries and multiple star systems - aims at a volume-complete sample of about 300 nearby F-, G-, and K-type stars that particularly avoids any kinematical or chemical pre-selection from the outset. It thereby provides an unbiased record of the local stellar populations - the ancient thick disc and the much younger thin disc. On this base, the detailed individual scrutiny of the long-lived stars of both populations unveils the thick disc as a single-burst component with a local normalization of no less than 20 per cent. This enormous fraction, combined with its much larger scaleheight, implies a mass for the thick disc that is comparable to that of the thin disc. On account of its completely different mass-to-light ratio the thick disc thereby becomes the dark side of the Milky Way, an ideal major source for baryonic dark matter. This massive, ancient population consequently challenges any gradual build-up scenario for our parent spiral. Even more, on the supposition that the Galaxy is not unusual, the thick disc - as it emerges from this unbiased spectroscopic work - particularly challenges the hierarchical cold-dark-matter-dominated formation picture for spiral galaxies in general.

The Spacelab IPS Star Simulator

Science.gov (United States)

Wessling, Francis C., III

The cost of doing business in space is very high. If errors occur while in orbit the costs grow and desired scientific data may be corrupted or even lost. The Spacelab Instrument Pointing System (IPS) Star Simulator is a unique test bed that allows star trackers to interface with simulated stars in a laboratory before going into orbit. This hardware-in-the loop testing of equipment on earth increases the probability of success while in space. The IPS Star Simulator provides three fields of view 2.55 x 2.55 degrees each for input into star trackers. The fields of view are produced on three separate monitors. Each monitor has 4096 x 4096 addressable points and can display 50 stars (pixels) maximum at a given time. The pixel refresh rate is 1000 Hz. The spectral output is approximately 550 nm. The available relative visual magnitude range is 2 to 8 visual magnitudes. The star size is less than 100 arc seconds. The minimum star movement is less than 5 arc seconds and the relative position accuracy is approximately 40 arc seconds. The purpose of this paper is to describe the LPS Star Simulator design and to provide an operational scenario so others may gain from the approach and possible use of the system.

Improving survey response rates from parents in school-based research using a multi-level approach.

Science.gov (United States)

Schilpzand, Elizabeth J; Sciberras, Emma; Efron, Daryl; Anderson, Vicki; Nicholson, Jan M

2015-01-01

While schools can provide a comprehensive sampling frame for community-based studies of children and their families, recruitment is challenging. Multi-level approaches which engage multiple school stakeholders have been recommended but few studies have documented their effects. This paper compares the impact of a standard versus enhanced engagement approach on multiple indicators of recruitment: parent response rates, response times, reminders required and sample characteristics. Parents and teachers were distributed a brief screening questionnaire as a first step for recruitment to a longitudinal study, with two cohorts recruited in consecutive years (cohort 1 2011, cohort 2 2012). For cohort 2, additional engagement strategies included the use of pre-notification postcards, improved study materials, and recruitment progress graphs provided to school staff. Chi-square and t-tests were used to examine cohort differences. Compared to cohort 1, a higher proportion of cohort 2 parents responded to the survey (76% versus 69%; p value of investing in a relatively simple multi-level strategy to maximise parent response rates, and potentially reduce recruitment time and costs.

Topological magnon bands in ferromagnetic star lattice

International Nuclear Information System (INIS)

Owerre, S A

2017-01-01

The experimental observation of topological magnon bands and thermal Hall effect in a kagomé lattice ferromagnet Cu(1–3, bdc) has inspired the search for topological magnon effects in various insulating ferromagnets that lack an inversion center allowing a Dzyaloshinskii–Moriya (DM) spin–orbit interaction. The star lattice (also known as the decorated honeycomb lattice) ferromagnet is an ideal candidate for this purpose because it is a variant of the kagomé lattice with additional links that connect the up-pointing and down-pointing triangles. This gives rise to twice the unit cell of the kagomé lattice, and hence more interesting topological magnon effects. In particular, the triangular bridges on the star lattice can be coupled either ferromagnetically or antiferromagnetically which is not possible on the kagomé lattice ferromagnets. Here, we study DM-induced topological magnon bands, chiral edge modes, and thermal magnon Hall effect on the star lattice ferromagnet in different parameter regimes. The star lattice can also be visualized as the parent material from which topological magnon bands can be realized for the kagomé and honeycomb lattices in some limiting cases. (paper)

Topological magnon bands in ferromagnetic star lattice.

Science.gov (United States)

Owerre, S A

2017-05-10

The experimental observation of topological magnon bands and thermal Hall effect in a kagomé lattice ferromagnet Cu(1-3, bdc) has inspired the search for topological magnon effects in various insulating ferromagnets that lack an inversion center allowing a Dzyaloshinskii-Moriya (DM) spin-orbit interaction. The star lattice (also known as the decorated honeycomb lattice) ferromagnet is an ideal candidate for this purpose because it is a variant of the kagomé lattice with additional links that connect the up-pointing and down-pointing triangles. This gives rise to twice the unit cell of the kagomé lattice, and hence more interesting topological magnon effects. In particular, the triangular bridges on the star lattice can be coupled either ferromagnetically or antiferromagnetically which is not possible on the kagomé lattice ferromagnets. Here, we study DM-induced topological magnon bands, chiral edge modes, and thermal magnon Hall effect on the star lattice ferromagnet in different parameter regimes. The star lattice can also be visualized as the parent material from which topological magnon bands can be realized for the kagomé and honeycomb lattices in some limiting cases.

Improving survey response rates from parents in school-based research using a multi-level approach.

Directory of Open Access Journals (Sweden)

Elizabeth J Schilpzand

Full Text Available While schools can provide a comprehensive sampling frame for community-based studies of children and their families, recruitment is challenging. Multi-level approaches which engage multiple school stakeholders have been recommended but few studies have documented their effects. This paper compares the impact of a standard versus enhanced engagement approach on multiple indicators of recruitment: parent response rates, response times, reminders required and sample characteristics.Parents and teachers were distributed a brief screening questionnaire as a first step for recruitment to a longitudinal study, with two cohorts recruited in consecutive years (cohort 1 2011, cohort 2 2012. For cohort 2, additional engagement strategies included the use of pre-notification postcards, improved study materials, and recruitment progress graphs provided to school staff. Chi-square and t-tests were used to examine cohort differences.Compared to cohort 1, a higher proportion of cohort 2 parents responded to the survey (76% versus 69%; p < 0.001, consented to participate (71% versus 56%; p < 0.001, agreed to teacher participation (90% versus 82%; p < 0.001 and agreed to follow-up contact (91% versus 80%; p < 0.001. Fewer cohort 2 parents required reminders (52% versus 63%; p < 0.001, and cohort 2 parents responded more promptly than cohort 1 parents (mean difference: 19.4 days, 95% CI: 18.0 to 20.9, p < 0.001.These results illustrate the value of investing in a relatively simple multi-level strategy to maximise parent response rates, and potentially reduce recruitment time and costs.

Visualization and spectral synthesis of rotationally distorted stars

International Nuclear Information System (INIS)

Dall, T H; Sbordone, L

2011-01-01

Simple spherical, non-rotating stellar models are inadequate when describing real stars in the limit of very fast rotation: Both the observable spectrum and the geometrical shape of the star deviate strongly from simple models. We attempt to approach the problem of modeling geometrically distorted, rapidly rotating stars from a new angle: By constructing distorted geometrical models and integrating standard stellar models with varying temperature, gravity, and abundances, over the entire surface, we attempt a semi-empirical approach to modeling. Here we present our methodology, and present simple examples of applications.

Helping families improve: an evaluation of two primary care approaches to parenting support in the Netherlands

NARCIS (Netherlands)

Graaf, I.M. de; Onrust, S.A.; Haverman, M.C.C.; Janssens, J.M.A.M.

2009-01-01

The present study evaluated two primary care parenting interventions. First, we evaluated the most widely used Dutch practices for primary care parenting support. Second, we assessed the applicability of the Primary Care Triple P approach, which is now being utilized in a wide variety of primary

Statistical approach to thermal evolution of neutron stars

International Nuclear Information System (INIS)

Beznogov, M V; Yakovlev, D G

2015-01-01

Studying thermal evolution of neutron stars (NSs) is one of a few ways to investigate the properties of superdense matter in their cores. We study the cooling of isolated NSs (INSs) and deep crustal heating of transiently accreting NSs in X-ray transients (XRTs, binary systems with low-mass companions). Currently, nearly 50 of such NSs are observed, and one can apply statistical methods to analyze the whole dataset. We propose a method for such analysis based on thermal evolution theory for individual stars and on averaging the results over NS mass distributions. We calculate the distributions of INSs and accreting NSs (ANSs) in XRTs over cooling and heating diagrams respectively. Comparing theoretical and observational distributions one can infer information on physical properties of superdense matter and on mass distributions of INSs and ANSs. (paper)

The great escape - II. Exoplanet ejection from dying multiple-star systems

Science.gov (United States)

Veras, Dimitri; Tout, Christopher A.

2012-05-01

Extrasolar planets and belts of debris orbiting post-main-sequence single stars may become unbound as the evolving star loses mass. In multiple-star systems, the presence or co-evolution of the additional stars can significantly complicate the prospects for orbital excitation and escape. Here, we investigate the dynamical consequences of multi-phasic, non-linear mass loss and establish a criterion for a system of any stellar multiplicity to retain a planet whose orbit surrounds all of the parent stars. For single stars which become white dwarfs, this criterion can be combined with the Chandrasekhar Limit to establish the maximum allowable mass-loss rate for planet retention. We then apply the criterion to circumbinary planets in evolving binary systems over the entire stellar mass phase space. Through about 105 stellar evolutionary track realizations, we characterize planetary ejection prospects as a function of binary separation, stellar mass and metallicity. This investigation reveals that planets residing at just a few tens of au from a central concentration of stars are susceptible to escape in a wide variety of multiple systems. Further, planets are significantly more susceptible to ejection from multiple-star systems than from single-star systems for a given system mass. For system masses greater than about 2 M⊙, multiple-star systems represent the greater source of free-floating planets.

Models of symbiotic stars

Science.gov (United States)

Friedjung, Michael

1993-01-01

One of the most important features of symbiotic stars is the coexistence of a cool spectral component that is apparently very similar to the spectrum of a cool giant, with at least one hot continuum, and emission lines from very different stages of ionization. The cool component dominates the infrared spectrum of S-type symbiotics; it tends to be veiled in this wavelength range by what appears to be excess emission in D-type symbiotics, this excess usually being attributed to circumstellar dust. The hot continuum (or continua) dominates the ultraviolet. X-rays have sometimes also been observed. Another important feature of symbiotic stars that needs to be explained is the variability. Different forms occur, some variability being periodic. This type of variability can, in a few cases, strongly suggest the presence of eclipses of a binary system. One of the most characteristic forms of variability is that characterizing the active phases. This basic form of variation is traditionally associated in the optical with the veiling of the cool spectrum and the disappearance of high-ionization emission lines, the latter progressively appearing (in classical cases, reappearing) later. Such spectral changes recall those of novae, but spectroscopic signatures of the high-ejection velocities observed for novae are not usually detected in symbiotic stars. However, the light curves of the 'symbiotic nova' subclass recall those of novae. We may also mention in this connection that radio observations (or, in a few cases, optical observations) of nebulae indicate ejection from symbiotic stars, with deviations from spherical symmetry. We shall give a historical overview of the proposed models for symbiotic stars and make a critical analysis in the light of the observations of symbiotic stars. We describe the empirical approach to models and use the observational data to diagnose the physical conditions in the symbiotics stars. Finally, we compare the results of this empirical

Relation between initial and minimum final white dwarf mass for Population I stars

Energy Technology Data Exchange (ETDEWEB)

Mazzitelli, I.; Dantona, F.

1986-12-01

The evolutionary paths for Population I stars having initial masses 1, 2.5, 3, 4, and 5 solar masses were computed from the homogeneous main sequence to the onset of the first major thermal pulse to evaluate the minimum mass and the chemical stratification of the remnant white dwarf (WD) associated with each parent mass. The helium flash phase was followed in detail for a 2.5 solar masses star, whereas for the 1 solar mass star the flash was bypassed, and the models at the beginning of the steady central helium burning phase were obtained by means of a scaling procedure upon the properly computed total and core masses. The results show that for a parent ranging between 1-3 solar masses the core mass at the first thermal pulse ranges only from 0.64-0.69 solar mass. If some very fast mass-loss mechanism is triggered in connection with the early stages of the thermal pulse phase, as suggested by the observed deficiency of asymptotic giant branch stars, the relation between final and initial mass is almost flat at least up to an initial mass of 3 solar masses, and the mass spectrum of the WDs is narrow and heavily peaked around 0.65 solar mass. 53 references.

Relation between initial and minimum final white dwarf mass for Population I stars

International Nuclear Information System (INIS)

Mazzitelli, I.; Dantona, F.; CNR, Istituto di Astrofisica Spaziale, Frascati; Roma, Osservatorio Astronomico, Rome, Italy)

1986-01-01

The evolutionary paths for Population I stars having initial masses 1, 2.5, 3, 4, and 5 solar masses were computed from the homogeneous main sequence to the onset of the first major thermal pulse to evaluate the minimum mass and the chemical stratification of the remnant white dwarf (WD) associated with each parent mass. The helium flash phase was followed in detail for a 2.5 solar masses star, whereas for the 1 solar mass star the flash was bypassed, and the models at the beginning of the steady central helium burning phase were obtained by means of a scaling procedure upon the properly computed total and core masses. The results show that for a parent ranging between 1-3 solar masses the core mass at the first thermal pulse ranges only from 0.64-0.69 solar mass. If some very fast mass-loss mechanism is triggered in connection with the early stages of the thermal pulse phase, as suggested by the observed deficiency of asymptotic giant branch stars, the relation between final and initial mass is almost flat at least up to an initial mass of 3 solar masses, and the mass spectrum of the WDs is narrow and heavily peaked around 0.65 solar mass. 53 references

Aboriginal parent support: A partnership approach.

Science.gov (United States)

Munns, Ailsa; Toye, Christine; Hegney, Desley; Kickett, Marion; Marriott, Rhonda; Walker, Roz

2018-02-01

This study was positioned within a larger action research study relating to a peer-led Aboriginal home visiting parent support program in an urban Western Australian setting. The aims for this study component were to identify program elements, exploring participants' perceptions of the program's suitability, feasibility, acceptability and effectiveness to inform program model recommendations and add to the body of knowledge on effective Aboriginal peer-led program models. The ability of Aboriginal parents to develop positive family environments is crucial, with parent support needing to be reflexive to local needs and sociocultural influences. Culturally appropriate service provision needs meaningful and acceptable strategies. This study was situated within a critical paradigm supporting Participatory Action Research methodology, using Action Learning Sets as the participant engagement and data collection setting. Within ten Action Learning Sets, focus group interviews were carried out with Aboriginal peer support workers, a non-Aboriginal parent support worker, an Aboriginal program coordinator, an Aboriginal education support officer and non-Aboriginal program managers (n = 8), and individual interviews with parents (n = 2) and community agencies (n = 4). Data were analysed using thematic analysis. Five themes were derived from peer support worker and community agency cohorts: peer support worker home visiting skills; responding to impacts of social determinants of health; client support and engagement; interagency collaboration; and issues addressing program sustainability. Parent responses augmented these themes. Participants identified five key elements relating to peer-led home visiting support for Aboriginal parents. These are uniquely placed to inform ongoing program development as there is little additional evidence in wider national and international contexts. Engagement with communities and peer support workers to develop culturally relevant

Spectrophotometry of ring nebulae around Wolf-Rayet stars

International Nuclear Information System (INIS)

Kwitter, K.B.

1979-01-01

Spectrophotometric observations of four ring nebulae surrounding population I Wolf-Rayet (WN) stars have been obtained, and four additional filamentary nebulae in order to determine the physical conditions and chemical abundances in these objects. It was concluded that the ring nebulae are enriched in nitrogen and helium as a result of contamination of the ambient interstellar medium by the helium- and nitrogen-rich wind from the central Wolf-Rayet star. Of the additional nebulae studied, two were found to be Peimbert Type I planetary nebulae, overabundant in nitrogen and helium due to mixing of CNO processed material into the parent envelope prior to ejection. One of the remaining objects, a shell around an Oef star, is found to have normal abundances; the other, a small H II region around an early Be star, also exhibits normal abundances. It was attempted to interpret the ring nebulae and the Oef shell as interstellar bubbles, according to recent theory; it met with varying degrees of success. For two of the ring nebulae, the fraction of nebular mass contributed by the central star can be estimated from published stellar abundances. It was found that in these two cases, the stellar wind has provided less than 10% of the observed nebular mass

StarLogo TNG

Science.gov (United States)

Klopfer, Eric; Scheintaub, Hal; Huang, Wendy; Wendel, Daniel

Computational approaches to science are radically altering the nature of scientific investigatiogn. Yet these computer programs and simulations are sparsely used in science education, and when they are used, they are typically “canned” simulations which are black boxes to students. StarLogo The Next Generation (TNG) was developed to make programming of simulations more accessible for students and teachers. StarLogo TNG builds on the StarLogo tradition of agent-based modeling for students and teachers, with the added features of a graphical programming environment and a three-dimensional (3D) world. The graphical programming environment reduces the learning curve of programming, especially syntax. The 3D graphics make for a more immersive and engaging experience for students, including making it easy to design and program their own video games. Another change to StarLogo TNG is a fundamental restructuring of the virtual machine to make it more transparent. As a result of these changes, classroom use of TNG is expanding to new areas. This chapter is concluded with a description of field tests conducted in middle and high school science classes.

Star cluster formation in a turbulent molecular cloud self-regulated by photoionization feedback

Science.gov (United States)

Gavagnin, Elena; Bleuler, Andreas; Rosdahl, Joakim; Teyssier, Romain

2017-12-01

Most stars in the Galaxy are believed to be formed within star clusters from collapsing molecular clouds. However, the complete process of star formation, from the parent cloud to a gas-free star cluster, is still poorly understood. We perform radiation-hydrodynamical simulations of the collapse of a turbulent molecular cloud using the RAMSES-RT code. Stars are modelled using sink particles, from which we self-consistently follow the propagation of the ionizing radiation. We study how different feedback models affect the gas expulsion from the cloud and how they shape the final properties of the emerging star cluster. We find that the star formation efficiency is lower for stronger feedback models. Feedback also changes the high-mass end of the stellar mass function. Stronger feedback also allows the establishment of a lower density star cluster, which can maintain a virial or sub-virial state. In the absence of feedback, the star formation efficiency is very high, as well as the final stellar density. As a result, high-energy close encounters make the cluster evaporate quickly. Other indicators, such as mass segregation, statistics of multiple systems and escaping stars confirm this picture. Observations of young star clusters are in best agreement with our strong feedback simulation.

Authoritative parenting and parental stress in parents of pre-school and older children with developmental disabilities.

Science.gov (United States)

Woolfson, L; Grant, E

2006-03-01

Rearing a child with a developmental disability is associated with increased parental stress. Theories of stress and adjustment and bi-directional theories of child development suggest that parenting could influence these negative outcomes. Relationships between parenting approaches and stress in parents of children with developmental disabilities (DD) (N = 53) were examined across two age groups, 3-5 years and 9-11 years and compared with a contrast group of typically developing children (TD) (N = 60). Measures used were the Parenting Stress Index-Short Form and Rickel and Biasatti's modification of Block's Child Rearing Practices Report, classified into Baumrind's parenting styles using Reitman and Gross's method. Parents in the older DD group used Authoritative parenting less than parents in the younger DD group, while the opposite developmental pattern was seen in the TD group. Multivariate analysis of variance showed a significant group x parenting style interaction for Parental Distress, Parent-Child Dysfunctional Interaction and Difficult Child. Stress measures were higher for the DD group and seemed to be associated with Authoritative parenting approaches, an effect that was not observed in the TD group. Findings suggest that the well-established effect of group on stress may be moderated by parenting style. Authoritative parenting may be highly stressful for parents of children with DD to implement, resulting in a decrease in its use across the two age groups.

Parents' explanatory models and hopes for outcomes of occupational therapy using a sensory integration approach.

Science.gov (United States)

Cohn, Ellen S; Kramer, Jessica; Schub, Jamie A; May-Benson, Teresa

2014-01-01

PURPOSE. To describe parents' concerns and hopes for their children who would be receiving occupational therapy using a sensory integration approach. METHOD. Content analysis of 275 parental responses to three open-ended questions on developmental-sensory history intake forms. FINDINGS. Parents' descriptions of why they sought for their children were categorized into four overarching concerns about their children's challenges: self-regulation, interacting with peers, participating in skilled motor activities, and self-confidence. Parents often linked these concerns together, revealing explanatory models of how they make sense of potential relationships among their children's challenges and how these challenges affect occupational performance. Parents hoped occupational therapy would help their children develop self-understanding and frustration tolerance to self-regulate their behavior in socially acceptable ways. IMPLICATIONS. Assessment and intervention should explicitly focus on links among self-regulation, social participation, skills, and perceived competence to address parents' expectations. Copyright © 2014 by the American Occupational Therapy Association, Inc.

Agreement between two different approaches to assess parent-reported sleep bruxism in children

Directory of Open Access Journals (Sweden)

Joyce Duarte

Full Text Available Introduction: Parents' report is the most used method for the study of sleep bruxism (SB in children, especially in research with large samples. However, there is no consensus about the questions used to assess SB, what may difficult the comparisons between studies. Objective: The aim of this research was to evaluate the agreement between two different approaches to assess possible sleep bruxism (PSB in children using parents' report. Methods: This cross-sectional study was conducted with 201 parents/caregivers. Prior to the questionnaire completion, all participants received a standard explanation of SB concept. Subsequently, the parents/caregivers answered a general question (GQ and a frequency-time question (FTQ about SB, and the answers were compared. Results: The majority of the participants were the children's mothers (73% and the childrens mean age was 7.5 years (SD: 2.25. PSB frequency in children did not differ statistically through the two questions [GQ: 30.7% (CI95%: 24.2 - 37.1 and FTQ: 26.6% (CI95%: 20.4 - 32.8], and an almost perfect agreement was observed between the answers (kp=0.812. Nevertheless, the FTQ showed a more coherent relation with the factors already recognized as associated with childhood bruxism than GQ. Conclusions: Different approaches result in similar PSB frequency, however, they show different ability to identify PSB associated factors and suggest the need of questions including frequency and time in further studies.

One or more bound planets per Milky Way star from microlensing observations.

Science.gov (United States)

Cassan, A; Kubas, D; Beaulieu, J-P; Dominik, M; Horne, K; Greenhill, J; Wambsganss, J; Menzies, J; Williams, A; Jørgensen, U G; Udalski, A; Bennett, D P; Albrow, M D; Batista, V; Brillant, S; Caldwell, J A R; Cole, A; Coutures, Ch; Cook, K H; Dieters, S; Prester, D Dominis; Donatowicz, J; Fouqué, P; Hill, K; Kains, N; Kane, S; Marquette, J-B; Martin, R; Pollard, K R; Sahu, K C; Vinter, C; Warren, D; Watson, B; Zub, M; Sumi, T; Szymański, M K; Kubiak, M; Poleski, R; Soszynski, I; Ulaczyk, K; Pietrzyński, G; Wyrzykowski, L

2012-01-11

Most known extrasolar planets (exoplanets) have been discovered using the radial velocity or transit methods. Both are biased towards planets that are relatively close to their parent stars, and studies find that around 17-30% (refs 4, 5) of solar-like stars host a planet. Gravitational microlensing, on the other hand, probes planets that are further away from their stars. Recently, a population of planets that are unbound or very far from their stars was discovered by microlensing. These planets are at least as numerous as the stars in the Milky Way. Here we report a statistical analysis of microlensing data (gathered in 2002-07) that reveals the fraction of bound planets 0.5-10 AU (Sun-Earth distance) from their stars. We find that 17(+6)(-9)% of stars host Jupiter-mass planets (0.3-10 M(J), where M(J) = 318 M(⊕) and M(⊕) is Earth's mass). Cool Neptunes (10-30 M(⊕)) and super-Earths (5-10 M(⊕)) are even more common: their respective abundances per star are 52(+22)(-29)% and 62(+35)(-37)%. We conclude that stars are orbited by planets as a rule, rather than the exception.

Observational constraints on neutron star masses and radii

Energy Technology Data Exchange (ETDEWEB)

Coleman Miller, M. [University of Maryland, Department of Astronomy and Joint Space-Science Institute, College Park, MD (United States); Lamb, Frederick K. [University of Illinois at Urbana-Champaign, Center for Theoretical Astrophysics and Department of Physics, Urbana, IL (United States); University of Illinois at Urbana-Champaign, Department of Astronomy, Urbana, IL (United States)

2016-03-15

Precise and reliable measurements of the masses and radii of neutron stars with a variety of masses would provide valuable guidance for improving models of the properties of cold matter with densities above the saturation density of nuclear matter. Several different approaches for measuring the masses and radii of neutron stars have been tried or proposed, including analyzing the X-ray fluxes and spectra of the emission from neutron stars in quiescent low-mass X-ray binary systems and thermonuclear burst sources; fitting the energy-dependent X-ray waveforms of rotation-powered millisecond pulsars, burst oscillations with millisecond periods, and accretion-powered millisecond pulsars; and modeling the gravitational radiation waveforms of coalescing double neutron star and neutron star - black hole binary systems. We describe the strengths and weaknesses of these approaches, most of which currently have substantial systematic errors, and discuss the prospects for decreasing the systematic errors in each method. (orig.)

Experiences of parents of children with special needs at school entry: a mixed method approach.

Science.gov (United States)

Siddiqua, A; Janus, M

2017-07-01

The transition from pre-school to kindergarten can be complex for children who need special assistance due to mental or physical disabilities (children with 'special needs'). We used a convergent mixed method approach to explore parents' experiences with service provision as their children transitioned to school. Parents (including one grandparent) of 37 children aged 4 to 6 years completed measures assessing their perceptions of and satisfaction with services. Semi-structured interviews were also conducted with 10 parents to understand their experience with services. Post transition, parents reported lower perceptions of services and decreased satisfaction than pre-transition. The following themes emerged from the qualitative data: qualities of services and service providers, communication and information transfer, parent advocacy, uncertainty about services, and contrasts and contradictions in satisfaction. The qualitative findings indicate that parents were both satisfied and concerned with aspects of the post-transition service provision. While the quantitative results suggested that parents' experience with services became less positive after their children entered school, the qualitative findings illustrated the variability in parents' experiences and components of service provision that require improvements to facilitate a successful school entry. © 2017 John Wiley & Sons Ltd.

Two Approaches to Estimating the Effect of Parenting on the Development of Executive Function in Early Childhood

Science.gov (United States)

Blair, Clancy; Raver, C. Cybele; Berry, Daniel J.

2015-01-01

In the current article, we contrast 2 analytical approaches to estimate the relation of parenting to executive function development in a sample of 1,292 children assessed longitudinally between the ages of 36 and 60 months of age. Children were administered a newly developed and validated battery of 6 executive function tasks tapping inhibitory control, working memory, and attention shifting. Residualized change analysis indicated that higher quality parenting as indicated by higher scores on widely used measures of parenting at both earlier and later time points predicted more positive gain in executive function at 60 months. Latent change score models in which parenting and executive function over time were held to standards of longitudinal measurement invariance provided additional evidence of the association between change in parenting quality and change in executive function. In these models, cross-lagged paths indicated that in addition to parenting predicting change in executive function, executive function bidirectionally predicted change in parenting quality. Results were robust with the addition of covariates, including child sex, race, maternal education, and household income-to-need. Strengths and drawbacks of the 2 analytic approaches are discussed, and the findings are considered in light of emerging methodological innovations for testing the extent to which executive function is malleable and open to the influence of experience. PMID:23834294

Neutron Stars and NuSTAR

Science.gov (United States)

Bhalerao, Varun

2012-05-01

My thesis centers around the study of neutron stars, especially those in massive binary systems. To this end, it has two distinct components: the observational study of neutron stars in massive binaries with a goal of measuring neutron star masses and participation in NuSTAR, the first imaging hard X-ray mission, one that is extremely well suited to the study of massive binaries and compact objects in our Galaxy. The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will carry the first focusing high energy X-ray telescope to orbit. NuSTAR has an order-of-magnitude better angular resolution and has two orders of magnitude higher sensitivity than any currently orbiting hard X-ray telescope. I worked to develop, calibrate, and test CdZnTe detectors for NuSTAR. I describe the CdZnTe detectors in comprehensive detail here - from readout procedures to data analysis. Detailed calibration of detectors is necessary for analyzing astrophysical source data obtained by the NuSTAR. I discuss the design and implementation of an automated setup for calibrating flight detectors, followed by calibration procedures and results. Neutron stars are an excellent probe of fundamental physics. The maximum mass of a neutron star can put stringent constraints on the equation of state of matter at extreme pressures and densities. From an astrophysical perspective, there are several open questions in our understanding of neutron stars. What are the birth masses of neutron stars? How do they change in binary evolution? Are there multiple mechanisms for the formation of neutron stars? Measuring masses of neutron stars helps answer these questions. Neutron stars in high-mass X-ray binaries have masses close to their birth mass, providing an opportunity to disentangle the role of "nature" and "nurture" in the observed mass distributions. In 2006, masses had been measured for only six such objects, but this small sample showed the greatest diversity in masses

Fluidic Manufacture of Star-Shaped Gold Nanoparticles.

Science.gov (United States)

Silvestri, Alessandro; Lay, Luigi; Psaro, Rinaldo; Polito, Laura; Evangelisti, Claudio

2017-07-21

Star-shaped gold nanoparticles (StarAuNPs) are extremely attractive nanomaterials, characterized by localized surface plasmon resonance which could be potentially employed in a large number of applications. However, the lack of a reliable and reproducible synthetic protocols for the production of StarAuNPs is the major limitation to their spreading. For the first time, here we present a robust protocol to manufacture reproducible StarAuNPs by exploiting a fluidic approach. Star-shaped AuNPs have been synthesized by means of a seed-less protocol, employing ascorbic acid as reducing agent at room temperature. Moreover, the versatility of the bench-top microfluidic protocol has been exploited to afford hydrophilic, hydrophobic and solid-supported engineered StarAuNPs, by avoiding intermediate NP purifications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effortful Control and Parents' Emotion Socialization Patterns Predict Children's Positive Social Behavior: A Person-Centered Approach

Science.gov (United States)

Miller, Rachel L.; Dunsmore, Julie C.; Smith, Cynthia L.

2015-01-01

Research Findings: We examined relations of effortful control with parent emotion socialization practices and child social behavior using a person-centered approach in children ages 18 months to 5 years. A total of 76 parents (66 mothers, 10 fathers) completed questionnaires at screening and 6-month follow-up. There were no age differences in…

Heartbeat stars and the ringing of tidal pulsations

OpenAIRE

García, RA; Hambleton, K; Kurtz, DW; Prsa, A; Fuller, J; Thompson (SU), S; Ballot, J

2015-01-01

With the advent of high precision photometry from satellites such as Kepler and CoRoT, a whole new layer of interesting and astounding astronomical objects has been revealed: heartbeat stars are an example of such objects. Heartbeat stars are eccen- tric ellipsoidal variables that undergo strong tidal interactions when the stars are almost in contact at the time of closest approach. These interactions deform of the stars and cause a notable light curve variation in the form of a tidal pulse. ...

Universal size properties of a star-ring polymer structure in disordered environments

Science.gov (United States)

Haydukivska, K.; Blavatska, V.

2018-03-01

We consider the complex polymer system, consisting of a ring polymer connected to the f1-branched starlike structure, in a good solvent in the presence of structural inhomogeneities. In particular cases f1=1 and f1=2 , such a system restores the synthesized tadpole-shaped polystyrenes [Doi et al., Macromolecules 46, 1075 (2013), 10.1021/ma302511j]. We assume that structural defects are correlated at large distances x according to a power law x-a. Applying the direct polymer renormalization approach, we evaluate the universal size characteristics such as the ratio of the radii of gyration of star-ring and star topologies, and compare the effective sizes of single arms in complex structures and isolated polymers of the same total molecular weight. The nontrivial impact of disorder on these quantities is analyzed.

Five-Star Schools: Defining Quality in Early Childhood Programs

Science.gov (United States)

Hertzog, Nancy B.

2012-01-01

Hakeem, Emily, Jose, and Latisha are all entering preschool in the fall. Their mothers are looking for the highest quality early childhood program they can find. Is there a guide for them to find a five-star program? Are all certified or accredited programs of equal quality? How do these parents and guardians know what defines quality in early…

Parental Bonding

Directory of Open Access Journals (Sweden)

T. Paul de Cock

2014-08-01

Full Text Available Estimating the early parent–child bonding relationship can be valuable in research and practice. Retrospective dimensional measures of parental bonding provide a means for assessing the experience of the early parent–child relationship. However, combinations of dimensional scores may provide information that is not readily captured with a dimensional approach. This study was designed to assess the presence of homogeneous groups in the population with similar profiles on parental bonding dimensions. Using a short version of the Parental Bonding Instrument (PBI, three parental bonding dimensions (care, authoritarianism, and overprotection were used to assess the presence of unobserved groups in the population using latent profile analysis. The class solutions were regressed on 23 covariates (demographics, parental psychopathology, loss events, and childhood contextual factors to assess the validity of the class solution. The results indicated four distinct profiles of parental bonding for fathers as well as mothers. Parental bonding profiles were significantly associated with a broad range of covariates. This person-centered approach to parental bonding has broad utility in future research which takes into account the effect of parent–child bonding, especially with regard to “affectionless control” style parenting.

The signatures of the parental cluster on field planetary systems

Science.gov (United States)

Cai, Maxwell Xu; Portegies Zwart, Simon; van Elteren, Arjen

2018-03-01

Due to the high stellar densities in young clusters, planetary systems formed in these environments are likely to have experienced perturbations from encounters with other stars. We carry out direct N-body simulations of multiplanet systems in star clusters to study the combined effects of stellar encounters and internal planetary dynamics. These planetary systems eventually become part of the Galactic field population as the parental cluster dissolves, which is where most presently known exoplanets are observed. We show that perturbations induced by stellar encounters lead to distinct signatures in the field planetary systems, most prominently, the excited orbital inclinations and eccentricities. Planetary systems that form within the cluster's half-mass radius are more prone to such perturbations. The orbital elements are most strongly excited in the outermost orbit, but the effect propagates to the entire planetary system through secular evolution. Planet ejections may occur long after a stellar encounter. The surviving planets in these reduced systems tend to have, on average, higher inclinations and larger eccentricities compared to systems that were perturbed less strongly. As soon as the parental star cluster dissolves, external perturbations stop affecting the escaped planetary systems, and further evolution proceeds on a relaxation time-scale. The outer regions of these ejected planetary systems tend to relax so slowly that their state carries the memory of their last strong encounter in the star cluster. Regardless of the stellar density, we observe a robust anticorrelation between multiplicity and mean inclination/eccentricity. We speculate that the `Kepler dichotomy' observed in field planetary systems is a natural consequence of their early evolution in the parental cluster.

Observational Constraints on Quark Matter in Neutron Stars

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

We study the observational constraints of mass and redshift on the properties of the equation of state (EOS) for quark matter in compact stars based on the quasi-particle description. We discuss two scenarios: strange stars and hybrid stars. We construct the equations of state utilizing an extended MIT bag model taking the medium effect into account for quark matter and the relativistic mean field theory for hadron matter. We show that quark matter may exist in strange stars and in the interior of neutron stars. The bag constant is a key parameter that affects strongly the mass of strange stars. The medium effect can lead to the stiffer hybrid-star EOS approaching the pure hadronic EOS, due to the reduction of quark matter, and hence the existence of heavy hybrid stars. We find that a middle range coupling constant may be the best choice for the hybrid stars being compatible with the observational constraints.

Unveiling hidden properties of young star clusters: differential reddening, star-formation spread, and binary fraction

Science.gov (United States)

Bonatto, C.; Lima, E. F.; Bica, E.

2012-04-01

Context. Usually, important parameters of young, low-mass star clusters are very difficult to obtain by means of photometry, especially when differential reddening and/or binaries occur in large amounts. Aims: We present a semi-analytical approach (ASAmin) that, when applied to the Hess diagram of a young star cluster, is able to retrieve the values of mass, age, star-formation spread, distance modulus, foreground and differential reddening, and binary fraction. Methods: The global optimisation method known as adaptive simulated annealing (ASA) is used to minimise the residuals between the observed and simulated Hess diagrams of a star cluster. The simulations are realistic and take the most relevant parameters of young clusters into account. Important features of the simulations are a normal (Gaussian) differential reddening distribution, a time-decreasing star-formation rate, the unresolved binaries, and the smearing effect produced by photometric uncertainties on Hess diagrams. Free parameters are cluster mass, age, distance modulus, star-formation spread, foreground and differential reddening, and binary fraction. Results: Tests with model clusters built with parameters spanning a broad range of values show that ASAmin retrieves the input values with a high precision for cluster mass, distance modulus, and foreground reddening, but they are somewhat lower for the remaining parameters. Given the statistical nature of the simulations, several runs should be performed to obtain significant convergence patterns. Specifically, we find that the retrieved (absolute minimum) parameters converge to mean values with a low dispersion as the Hess residuals decrease. When applied to actual young clusters, the retrieved parameters follow convergence patterns similar to the models. We show how the stochasticity associated with the early phases may affect the results, especially in low-mass clusters. This effect can be minimised by averaging out several twin clusters in the

Radial Velocity Survey of T Tauri Stars in Taurus-Auriga

Science.gov (United States)

Crockett, Christopher; Mahmud, N.; Huerta, M.; Prato, L.; Johns-Krull, C.; Hartigan, P.; Jaffe, D.

2009-01-01

Is the frequency of giant planet companions to young stars similar to that seen around old stars? Is the "brown dwarf desert" a product of how low-mass companion objects form, or of how they evolve? Some models indicate that both giant planets and brown dwarfs should be common at young ages within 3 AU of a primary star, but migration induced by massive disks drive brown dwarfs into the parent stars, leaving behind proportionally more giant planets. Our radial velocity survey of young stars will provide a census of the young giant planet and brown dwarf population in Taurus-Auriga. In this poster we present our progress in quantifying how spurious radial velocity signatures are caused by stellar activity and in developing models to help distinguish between companion induced and spot induced radial velocity variations. Early results stress the importance of complementary observations in both visible light and NIR. We present our technique to determine radial velocities by fitting telluric features and model stellar features to our observed spectra. Finally, we discuss ongoing observations at McDonald Observatory, KPNO, and the IRTF, and several new exoplanet host candidates.

Parent Counseling in Music Therapy for parents of children with Autism

DEFF Research Database (Denmark)

Gottfried, Tali

Music Therapy has consolidated it's position as an effective treatment approach for children with ASD. The use of MT way of thinking and MT-like techniques by the parents in everyday life, can contribute to improve their understanding of their child's needs, and help to cope with daily challanges....... The lecture will present a Parent Counseling approach upon an extensive clinical experience in working with parents of children with ASD, and will conclude examples from counseling sessions. This approach is now tested through research....

Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

Energy Technology Data Exchange (ETDEWEB)

Theodorakis, P E [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Avgeropoulos, A [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Freire, J J [Departamento de Ciencias y Tecnicas FisicoquImicas, Universidad Nacional de Educacion a Distancia, Facultad de Ciencias, Senda del Rey 9, 28040 Madrid (Spain); Kosmas, M [Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece); Vlahos, C [Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece)

2007-11-21

The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results.

Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

Science.gov (United States)

Theodorakis, P. E.; Avgeropoulos, A.; Freire, J. J.; Kosmas, M.; Vlahos, C.

2007-11-01

The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results.

Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

International Nuclear Information System (INIS)

Theodorakis, P E; Avgeropoulos, A; Freire, J J; Kosmas, M; Vlahos, C

2007-01-01

The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results

Association between parental guilt and oral health problems in preschool children: a hierarchical approach.

Science.gov (United States)

Gomes, Monalisa Cesarino; Clementino, Marayza Alves; Pinto-Sarmento, Tassia Cristina de Almeida; Martins, Carolina Castro; Granville-Garcia, Ana Flávia; Paiva, Saul Martins

2014-08-16

Dental caries and traumatic dental injury (TDI) can play an important role in the emergence of parental guilt, since parents feel responsible for their child's health. The aim of the present study was to evaluate the influence of oral health problems among preschool children on parental guilt. A preschool-based, cross-sectional study was carried out with 832 preschool children between three and five years of age in the city of Campina Grande, Brazil. Parents/caregivers answered the Brazilian version of the Early Childhood Oral Health Impact Scale (B-ECOHIS). The item "parental guilt" was the dependent variable. Questionnaires addressing socio-demographic variables (child's sex, child's age, parent's/caregiver's age, mother's schooling, type of preschool and household income), history of toothache and health perceptions (general and oral) were also administered. Clinical exams for dental caries and TDI were performed by three dentists who had undergone a training and calibration exercise (Kappa: 0.85-0.90). Poisson hierarchical regression was used to determine the significance of associations between parental guilt and oral health problems (α = 5%). The multivariate model was carried out on three levels using a hierarchical approach from distal to proximal determinants: 1) socio-demographic aspects; 2) health perceptions; and 3) oral health problems. The frequency of parental guilt was 22.8%. The following variables were significantly associated with parental guilt: parental perception of child's oral health as poor (PR = 2.010; 95% CI: 1.502-2.688), history of toothache (PR = 2.344; 95% CI: 1.755-3.130), cavitated lesions (PR = 2.002; 95% CI: 1.388-2.887), avulsion/luxation (PR = 2.029; 95% CI: 1.141-3.610) and tooth discoloration (PR = 1.540; 95% CI: 1.169-2.028). Based on the present findings, parental guilt increases with the occurrence of oral health problems that require treatment, such as dental caries and TDI of greater severity. Parental perceptions of

Novel approach to parental permission and child assent for research: improving comprehension.

Science.gov (United States)

O'Lonergan, Theresa A; Forster-Harwood, Jeri E

2011-05-01

The aim of this research was to test a multimedia permission/assent (P/A) process. The overall hypothesis was that children and their parents exposed to a multimedia P/A process would have better comprehension compared with those exposed to a text-based process. Traditional and multimedia P/A processes were created by using an innovative learning-objective approach. A total of 194 parent-child dyads (children aged 11-14 years) were enrolled: 24 dyads in a prestudy testing P/A components for preference and effect on comprehension and 170 dyads in a randomized trial of a multimedia or paper P/A process for a hypothetical study. Participants were predominantly white and were from a metropolitan area served by a tertiary care pediatric hospital and outpatient facility. Comprehension of 8 essential elements of the P/A process was assessed. The majority of prestudy subjects preferred the video version of the dual-energy radiograph absorptiometry description over the animated and paper versions combined (41 of 48 [85%]; P better overall comprehension compared with the paper P/A process (P = .0009), and there were highly significant differences in understanding of study procedures (P = .0002) and risks (P multimedia group had significantly better overall comprehension (P = .03). Multimedia approaches to the research P/A process may improve overall understanding of research participation for children and parents. Improved understanding of study-specific research components (rather than research rights) may improve overall comprehension.

The Need for an Ecological Approach to Parental Stress in Autism Spectrum Disorders: The Combined Role of Individual and Environmental Factors

Science.gov (United States)

Derguy, C.; M'Bailara, K.; Michel, G.; Roux, S.; Bouvard, M.

2016-01-01

This study aimed to identify parental stress predictors in ASD by considering individual and environmental factors in an ecological approach. Participants were 115 parents of children with ASD aged from 3 to 10 years. Multiple regression analyses were conducted to determine the best predictors of parental stress among child-related, parent-related…

Hyperon-mixed neutron stars

International Nuclear Information System (INIS)

Takatsuka, Tatsuyuki

2004-01-01

Hyperon mixing in neutron star matter is investigated by the G-matrix-based effective interaction approach under the attention to use the YN and the YY potentials compatible with hypernuclear data and is shown to occur at densities relevant to neutron star cores, together with discussions to clarify the mechanism of hyperon contamination. It is remarked that developed Y-mixed phase causes a dramatic softening of the neutron star equation of state and leads to the serious problem that the resulting maximum mass M max for neutron star model contradicts the observed neutron star mass (M max obs = 1.44 M Θ ), suggesting the necessity of some extra repulsion'' in hypernuclear system. It is shown that the introduction of three-body repulsion similar to that in nuclear system can resolve the serious situation and under the consistency with observation (M max > M obs ) the threshold densities for Λ and Σ - are pushed to higher density side, from 2ρ 0 to ∼ 4ρ 0 (ρ 0 being the nuclear density). On the basis of a realistic Y-mixed neutron star model, occurrence of Y-superfluidity essential for ''hyperon cooling'' scenario is studied and both of Λ- and Σ - -superfluids are shown to be realized with their critical temperatures 10 8-9 K, meaning that the hyperon cooling'' is a promising candidate for a fast non-standard cooling demanded for some neutron stars with low surface temperature. A comment is given as to the consequence of less attractive ΛΛ interaction suggested by the ''NAGARA event'' ΛΛ 6 He. (author)

Communicating in complex situations: a normative approach to HIV-related talk among parents who are HIV+.

Science.gov (United States)

Edwards, Laura L; Donovan-Kicken, Erin; Reis, Janet S

2014-01-01

Parents with HIV/AIDS are confronted with unique challenges when discussing HIV-related information with their children. Strategies for navigating these challenges effectively have not been systematically examined. In this study, we conducted in-depth interviews with 76 parents with HIV/AIDS who had children ages 10-18 years. Guided by O'Keefe and Delia's definition of a complex communication situation and Goldsmith's normative approach to interpersonal communication, we examined parents' goals for discussing HIV-related information, factors that made conversations challenging, and instances where these conversational purposes conflicted with one another. Our data reveal the following parent-adolescent communication predicaments: relaying safety information about HIV while minimizing child anxiety, modeling open family communication without damaging one's parental identity, and balancing parent-child relational needs amid living with an unpredictable health condition. Parents also described a variety of strategies for mitigating challenges when discussing HIV-related topics. Strategies parents perceived as effective included reframing HIV as a chronic, manageable illness; keeping talk educational; and embedding HIV-related topics within more general conversations. The theoretical and practical applications of these findings are discussed with regard to their relevance to health communication scholars and HIV care professionals.

Dynamics of H II regions around exiled O stars

Science.gov (United States)

Mackey, Jonathan; Langer, Norbert; Gvaramadze, Vasilii V.

2013-11-01

At least 25 per cent of massive stars are ejected from their parent cluster, becoming runaways or exiles, travelling with often-supersonic space velocities through the interstellar medium (ISM). Their overpressurized H II regions impart kinetic energy and momentum to the ISM, compress and/or evaporate dense clouds, and can constrain properties of both the star and the ISM. Here, we present one-, two- and (the first) three-dimensional simulations of the H II region around a massive star moving supersonically through a uniform, magnetized ISM, with properties appropriate for the nearby O star ζ Oph. The H II region leaves an expanding overdense shell behind the star and, inside this, an underdense wake that should be filled with hot gas from the shocked stellar wind. The gas column density in the shell is strongly influenced by the ISM magnetic field strength and orientation. Hα emission maps show that H II region remains roughly circular, although the star is displaced somewhat from the centre of emission. For our model parameters, the kinetic energy feedback from the H II region is comparable to the mechanical luminosity of the stellar wind, and the momentum feedback rate is >100 times larger than that from the wind and ≈10 times larger than the total momentum input rate available from radiation pressure. Compared to the star's eventual supernova explosion, the kinetic energy feedback from the H II region over the star's main-sequence lifetime is >100 times less, but the momentum feedback is up to 4 times larger. H II region dynamics are found to have only a small effect on the ISM conditions that a bow shock close to the star would encounter.

STARS experiential group intervention: a complex trauma treatment approach for survivors of human trafficking.

Science.gov (United States)

Hopper, Elizabeth K; Azar, Naomi; Bhattacharyya, Sriya; Malebranche, Dominique A; Brennan, Kelsey E

2018-01-01

This is the abstract that was submitted online with the paper: Despite the fact that many survivors of human trafficking have experienced complex trauma, there are no established interventions designed to specifically address these impacts. Leaders in the field of complex trauma have advocated for the need for somatic approaches to intervention. This paper presents STARS Experiential Group treatment, the first structured bodybased group intervention that has been designed to address complex trauma in survivors of human trafficking. Three pilot groups were run in residential settings with adolescent and adult survivors of sex trafficking. Two adaptations were utilized, with one focusing on application of expressive arts modalities and the other incorporating theater games. Qualitative results, using thematic analysis, identified several themes related to challenges and potential benefits of these groups. Potential benefits of the STARS groups were found in the areas of Interpersonal Relationships, Regulation, and Self/ Identity, with fourteen sub-themes further describing positive impacts. Challenges within these areas are explored, to inform the development of group interventions for trafficking survivors. The results of this paper suggest that experiential, somatically-oriented group treatment shows promise as an important element of holistic intervention with trafficking survivors.

The influence of parent's body mass index on peer selection: an experimental approach using virtual reality.

Science.gov (United States)

Martarelli, Corinna S; Borter, Natalie; Bryjova, Jana; Mast, Fred W; Munsch, Simone

2015-11-30

Relatively little is known about the influence of psychosocial factors, such as familial role modeling and social network on the development and maintenance of childhood obesity. We investigated peer selection using an immersive virtual reality environment. In a virtual schoolyard, children were confronted with normal weight and overweight avatars either eating or playing. Fifty-seven children aged 7-13 participated. Interpersonal distance to the avatars, child's BMI, self-perception, eating behavior and parental BMI were assessed. Parental BMI was the strongest predictor for the children's minimal distance to the avatars. Specifically, a higher mothers' BMI was associated with greater interpersonal distance and children approached closer to overweight eating avatars. A higher father's BMI was associated with a lower interpersonal distance to the avatars. These children approached normal weight playing and overweight eating avatar peers closest. The importance of parental BMI for the child's social approach/avoidance behavior can be explained through social modeling mechanisms. Differential effects of paternal and maternal BMI might be due to gender specific beauty ideals. Interventions to promote social interaction with peer groups could foster weight stabilization or weight loss in children. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Parental Identification by the Adolescent: A Social Power Approach

Science.gov (United States)

McDonald, Gerald W.

1977-01-01

A social power theory of parental identification is presented, in contrast to sex-role theories of identification, which argues that the more parental power each parent is perceived to have, the higher the degree of adolescent identification with that parent. (Author)

Financial literacy among Turkish college students: the role of formal education, learning approaches, and parental teaching.

Science.gov (United States)

Akben-Selcuk, Elif; Altiok-Yilmaz, Ayse

2014-10-01

This study assessed financial literacy and its correlates among Turkish college students, with special emphasis on the role of formal education, learning approaches, and parental influences. Financial literacy was measured by the College Student Financial Literacy Survey, which assesses knowledge in four areas: general financial management, saving and borrowing, insurance, and investing. 853 Turkish university students were administered the survey (416 men, 437 women; M age = 20.3 yr., SD = 0.6). The mean percentage of correct responses was 45% (SD = 12.8%). Regression results showed that formal finance education in college, a deep approach to learning, and direct financial teaching by parents were significantly associated with higher financial literacy scores.

How neutron stars constrain the nuclear equation of state

Directory of Open Access Journals (Sweden)

Hell Thomas

2014-03-01

Full Text Available Recent neutron star observations set new constraints for the equation of state of baryonic matter. A chiral effective field theory approach is used for the description of neutron-dominated nuclear matter present in the outer core of neutron stars. Possible hybrid stars with quark matter in the inner core are discussed using a three-flavor Nambu–Jona-Lasinio model.

Neutron stars

International Nuclear Information System (INIS)

Irvine, J.M.

1978-01-01

The subject is covered in chapters entitled: introduction (resume of stellar evolution, gross characteristics of neutron stars); pulsars (pulsar characteristics, pulsars as neutron stars); neutron star temperatures (neutron star cooling, superfluidity and superconductivity in neutron stars); the exterior of neutron stars (the magnetosphere, the neutron star 'atmosphere', pulses); neutron star structure; neutron star equations of state. (U.K.)

Star marketer’s impact on the market strategy choice

OpenAIRE

Goran, Vlašić; Hair, Joe F.; Krupka, Zoran

2017-01-01

We focus on understanding the role of star marketers in pursuing a market-driven vs. a market-driving strategy. Results indicate that market-driving and market-driven strategies are two approaches that can be pursued by market-oriented firms. A star marketer has a robust positive influence on market-driving strategy. In contrast, a star marketer has no meaningful influence on market-driven strategy. In short, while star marketers are very important for market-driving strategy and long term su...

Heartbeat Stars and the Ringing of Tidally Induced Pulsations

OpenAIRE

Hambleton, K.; Kurtz, D.; Prša, A.; Fuller, J.; Thompson, S.

2015-01-01

With the advent of high precision photometry from satellites such as Kepler and CoRoT, a whole new layer of interesting and astounding astronomical objects has been revealed: heartbeat stars are a prime example of such objects. Heartbeat stars are eccentric ellipsoidal variables that undergo strong tidal interactions at the time of closest approach, when the stars are almost in contact. These interactions cause a significant variation in the surface areas of the stars and are observed in the ...

CARBON NEUTRON STAR ATMOSPHERES

International Nuclear Information System (INIS)

Suleimanov, V. F.; Klochkov, D.; Werner, K.; Pavlov, G. G.

2014-01-01

The accuracy of measuring the basic parameters of neutron stars is limited in particular by uncertainties in the chemical composition of their atmospheres. For example, the atmospheres of thermally emitting neutron stars in supernova remnants might have exotic chemical compositions, and for one of them, the neutron star in Cas A, a pure carbon atmosphere has recently been suggested by Ho and Heinke. To test this composition for other similar sources, a publicly available detailed grid of the carbon model atmosphere spectra is needed. We have computed this grid using the standard local thermodynamic equilibrium approximation and assuming that the magnetic field does not exceed 10 8  G. The opacities and pressure ionization effects are calculated using the Opacity Project approach. We describe the properties of our models and investigate the impact of the adopted assumptions and approximations on the emergent spectra

Different Strokes for Different Folks? Contrasting Approaches to Cultural Adaptation of Parenting Interventions.

Science.gov (United States)

Mejia, Anilena; Leijten, Patty; Lachman, Jamie M; Parra-Cardona, José Ruben

2017-08-01

Relevant achievements have been accomplished in prevention science with regard to disseminating efficacious parenting interventions among underserved populations. However, widespread disparities in availability of parenting services continue to negatively impact diverse populations in high-income countries (e.g., the USA) and low- and middle-income countries. As a result, a scholarly debate on cultural adaptation has evolved over the years. Specifically, some scholars have argued that in diverse cultural contexts, existing evidence-based parenting interventions should be delivered with strict fidelity to ensure effectiveness. Others have emphasized the need for cultural adaptations of interventions when disseminated among diverse populations. In this paper, we propose that discussions on cultural adaptation should be conceptualized as a "both-and," rather than an "either-or" process. To justify this stance, we describe three distinct parenting intervention projects to illustrate how cultural adaptation and efficacy of evidence-based interventions can be achieved using contrasting approaches and frameworks, depending on cultural preferences and available resources of local contexts. Further, we suggest the need to develop guidelines for consistent reporting of cultural adaptation procedures as a critical component of future investigations. This discussion is relevant for the broader public health field and prevention science.

Optical System Error Analysis and Calibration Method of High-Accuracy Star Trackers

Directory of Open Access Journals (Sweden)

Zheng You

2013-04-01

Full Text Available The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers.

Optical system error analysis and calibration method of high-accuracy star trackers.

Science.gov (United States)

Sun, Ting; Xing, Fei; You, Zheng

2013-04-08

The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers.

Noether's stars in f (R) gravity

Science.gov (United States)

De Laurentis, Mariafelicia

2018-05-01

The Noether Symmetry Approach can be used to construct spherically symmetric solutions in f (R) gravity. Specifically, the Noether conserved quantity is related to the gravitational mass and a gravitational radius that reduces to the Schwarzschild radius in the limit f (R) → R. We show that it is possible to construct the M- R relation for neutron stars depending on the Noether conserved quantity and the associated gravitational radius. This approach enables the recovery of extreme massive stars that could not be stable in the standard Tolman-Oppenheimer-Volkoff based on General Relativity. Examples are given for some power law f (R) gravity models.

Integrating Faith-based and Community-based Participatory Research Approaches to Adapt the Korean Parent Training Program.

Science.gov (United States)

Kim, Eunjung; Boutain, Doris; Kim, Sangho; Chun, Jin-Joo; Im, Hyesang

Faith and community based inquiry approaches are rarely used to develop research interventions. The purpose of this article is to present how a research team worked with six Korean American Christian churches to revise the prototype Korean Parent Training Program (KPTP), based upon the Bright Futures Parenting Program. The collaboration was sought to better integrate and align the KPTP with Korean culture and faith. The KPTP was developed to promote positive parenting practices and decrease mental health disparities of Korean American children. Sixteen church participants completed a Delphi survey, a workshop series, Community Theaters, and focus groups. The participants suggested adding Korean traditional parenting virtues, Christian parenting principles, and revising the standardized parent training and program philosophy. Revisions made KPTP sensitive to Korean culture and faith, and promoted program acceptability. The process demonstrated the importance of working with church volunteers to develop faith-based and community-based health promotion interventions targeting Korean American faith communities. This research presents significant and meaningful implications for working with other faith communities from minority backgrounds. Copyright © 2017 Elsevier Inc. All rights reserved.

The gravitational interaction between N-body (star clusters) and hydrodynamic (ISM) codes in disk galaxy simulations

International Nuclear Information System (INIS)

Schroeder, M.C.; Comins, N.F.

1986-01-01

During the past twenty years, three approaches to numerical simulations of the evolution of galaxies have been developed. The first approach, N-body programs, models the motion of clusters of stars as point particles which interact via their gravitational potentials to determine the system dynamics. Some N-body codes model molecular clouds as colliding, inelastic particles. The second approach, hydrodynamic models of galactic dynamics, simulates the activity of the interstellar medium as a compressible gas. These models presently do not include stars, the effect of gravitational fields, or allow for stellar evolution and exchange of mass or angular momentum between stars and the interstellar medium. The third approach, stochastic star formation simulations of disk galaxies, allows for the interaction between stars and interstellar gas, but does not allow the star particles to move under the influence of gravity

The Gravitational Million-Body Problem: A Multidisciplinary Approach to Star Cluster Dynamics

International Nuclear Information System (INIS)

Tremaine, Scott

2003-01-01

focus on N 10 6 for two main reasons: first, direct numerical integrations of N-body systems are beginning to approach this threshold, and second, globular star clusters provide remarkably accurate physical instantiations of the idealized N-body problem with N = 10 5 - 10 6 . The authors are distinguished contributors to the study of star-cluster dynamics and the gravitational N-body problem. The book contains lucid and concise descriptions of most of the important tools in the subject, with only a modest bias towards the authors' own interests. These tools include the two-body relaxation approximation, the Vlasov and Fokker-Planck equations, regularization of close encounters, conducting fluid models, Hill's approximation, Heggie's law for binary star evolution, symplectic integration algorithms, Liapunov exponents, and so on. The book also provides an up-to-date description of the principal processes that drive the evolution of idealized N-body systems - two-body relaxation, mass segregation, escape, core collapse and core bounce, binary star hardening, gravothermal oscillations - as well as additional processes such as stellar collisions and tidal shocks that affect real star clusters but not idealized N-body systems. In a relatively short (300 pages plus appendices) book such as this, many topics have to be omitted. The reader who is hoping to learn about the phenomenology of star clusters will be disappointed, as the description of their properties is limited to only a page of text; there is also almost no discussion of other, equally interesting N-body systems such as galaxies(N ∼ 10 6 - 10 12 ), open clusters (N ≅ 10 2 - 10 4 ), planetary systems, or the star clusters surrounding black holes that are found in the centres of most galaxies. All of these omissions are defensible decisions. Less defensible is the uneven set of references in the text; for example, nowhere is the reader informed that the classic predecessor to this work was Spitzer's 1987 monograph

Parent disclosure of complementary health approaches used for children with autism spectrum disorder: Barriers and facilitators.

Science.gov (United States)

Lindly, Olivia; Thorburn, Sheryl; Heisler, Karen; Reyes, Nuri; Zuckerman, Katharine

2017-12-01

Complementary health approaches (CHA) are widely used among children with autism spectrum disorder (ASD). As part of shared treatment decision-making, healthcare providers are encouraged to discuss CHA with parents of children with ASD. Yet prior research suggests that parents often do not disclose CHA used for children, and their reasons for nondisclosure are poorly understood. We, therefore, aimed to identify barriers and facilitators to parent disclosure of CHA used for children with ASD. In-depth interviews were conducted with 31 parents who reported that they were currently using CHA for their child's ASD in Denver, Colorado or Portland, Oregon. We used content analysis to identify six main themes indicating that the following factors play a role in disclosure: parents' drive to optimize their child's health, parent self-efficacy discussing CHA with healthcare providers, parent beliefs about the effectiveness of CHA, parent-provider relationship quality, provider attitudes and knowledge regarding CHA and ASD, and visit characteristics. Study findings suggest that family and health system factors, together, influence parent disclosure of CHA used for children with ASD. Multifaceted intervention concurrently targeting the CHA-related knowledge, beliefs, and self-efficacy of parents whose children have been recently diagnosed with ASD, in addition to the CHA-related attitudes and knowledge of their healthcare providers may promote disclosure and shared treatment decision-making about the use of CHA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neutron Star Science with the NuSTAR

Energy Technology Data Exchange (ETDEWEB)

Vogel, J. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-10-16

The Nuclear Spectroscopic Telescope Array (NuSTAR), launched in June 2012, helped scientists obtain for the first time a sensitive high-­energy X-­ray map of the sky with extraordinary resolution. This pioneering telescope has aided in the understanding of how stars explode and neutron stars are born. LLNL is a founding member of the NuSTAR project, with key personnel on its optics and science team. We used NuSTAR to observe and analyze the observations of different neutron star classes identified in the last decade that are still poorly understood. These studies not only help to comprehend newly discovered astrophysical phenomena and emission processes for members of the neutron star family, but also expand the utility of such observations for addressing broader questions in astrophysics and other physics disciplines. For example, neutron stars provide an excellent laboratory to study exotic and extreme phenomena, such as the equation of state of the densest matter known, the behavior of matter in extreme magnetic fields, and the effects of general relativity. At the same time, knowing their accurate populations has profound implications for understanding the life cycle of massive stars, star collapse, and overall galactic evolution.

REMAINING LIFE TIME PREDICTION OF BEARINGS USING K-STAR ALGORITHM – A STATISTICAL APPROACH

Directory of Open Access Journals (Sweden)

R. SATISHKUMAR

2017-01-01

Full Text Available The role of bearings is significant in reducing the down time of all rotating machineries. The increasing trend of bearing failures in recent times has triggered the need and importance of deployment of condition monitoring. There are multiple factors associated to a bearing failure while it is in operation. Hence, a predictive strategy is required to evaluate the current state of the bearings in operation. In past, predictive models with regression techniques were widely used for bearing lifetime estimations. The Objective of this paper is to estimate the remaining useful life of bearings through a machine learning approach. The ultimate objective of this study is to strengthen the predictive maintenance. The present study was done using classification approach following the concepts of machine learning and a predictive model was built to calculate the residual lifetime of bearings in operation. Vibration signals were acquired on a continuous basis from an experiment wherein the bearings are made to run till it fails naturally. It should be noted that the experiment was carried out with new bearings at pre-defined load and speed conditions until the bearing fails on its own. In the present work, statistical features were deployed and feature selection process was carried out using J48 decision tree and selected features were used to develop the prognostic model. The K-Star classification algorithm, a supervised machine learning technique is made use of in building a predictive model to estimate the lifetime of bearings. The performance of classifier was cross validated with distinct data. The result shows that the K-Star classification model gives 98.56% classification accuracy with selected features.

Counseling parents of difficult adolescents.

Science.gov (United States)

Joseph-DiCaprio, Julia

2010-09-01

The relationship between parent and child changes during adolescence. During that transition time, some youths may be challenging rules, engaging in risky behaviors, or failing to disclose their activities to their parents. Physicians and other health care providers are in a position to counsel not only youths about problem behaviors but also parents about how to more effectively deal with their children. One of the things they can recommend is an approach known as authoritative parenting. This approach has been shown to promote higher school achievement and self-esteem, and result in less depression and anxiety and more self-reliance among youths. This article describes the approach and offers physicians tips about what they can say to parents.

O stars and Wolf-Rayet stars

International Nuclear Information System (INIS)

Conti, P.S.; Underhill, A.B.; Jordan, S.; Thomas, R.

1988-01-01

Basic information is given about O and Wolf-Rayet stars indicating how these stars are defined and what their chief observable properties are. Part 2 of the volume discussed four related themes pertaining to the hottest and most luminous stars. Presented are: an observational overview of the spectroscopic classification and extrinsic properties of O and Wolf-Rayet stars; the intrinsic parameters of luminosity, effective temperature, mass, and composition of the stars, and a discussion of their viability; stellar wind properties; and the related issues concerning the efforts of stellar radiation and wind on the immediate interstellar environment are presented

O stars and Wolf-Rayet stars

Science.gov (United States)

Conti, Peter S.; Underhill, Anne B.; Jordan, Stuart (Editor); Thomas, Richard (Editor)

1988-01-01

Basic information is given about O and Wolf-Rayet stars indicating how these stars are defined and what their chief observable properties are. Part 2 of the volume discussed four related themes pertaining to the hottest and most luminous stars. Presented are: an observational overview of the spectroscopic classification and extrinsic properties of O and Wolf-Rayet stars; the intrinsic parameters of luminosity, effective temperature, mass, and composition of the stars, and a discussion of their viability; stellar wind properties; and the related issues concerning the efforts of stellar radiation and wind on the immediate interstellar environment are presented.

A robust star identification algorithm with star shortlisting

Science.gov (United States)

Mehta, Deval Samirbhai; Chen, Shoushun; Low, Kay Soon

2018-05-01

A star tracker provides the most accurate attitude solution in terms of arc seconds compared to the other existing attitude sensors. When no prior attitude information is available, it operates in "Lost-In-Space (LIS)" mode. Star pattern recognition, also known as star identification algorithm, forms the most crucial part of a star tracker in the LIS mode. Recognition reliability and speed are the two most important parameters of a star pattern recognition technique. In this paper, a novel star identification algorithm with star ID shortlisting is proposed. Firstly, the star IDs are shortlisted based on worst-case patch mismatch, and later stars are identified in the image by an initial match confirmed with a running sequential angular match technique. The proposed idea is tested on 16,200 simulated star images having magnitude uncertainty, noise stars, positional deviation, and varying size of the field of view. The proposed idea is also benchmarked with the state-of-the-art star pattern recognition techniques. Finally, the real-time performance of the proposed technique is tested on the 3104 real star images captured by a star tracker SST-20S currently mounted on a satellite. The proposed technique can achieve an identification accuracy of 98% and takes only 8.2 ms for identification on real images. Simulation and real-time results depict that the proposed technique is highly robust and achieves a high speed of identification suitable for actual space applications.

Star-Branched Polymers (Star Polymers)

KAUST Repository

Hirao, Akira

2015-09-01

The synthesis of well-defined regular and asymmetric mixed arm (hereinafter miktoarm) star-branched polymers by the living anionic polymerization is reviewed in this chapter. In particular, much attention is being devoted to the synthetic development of miktoarm star polymers since 2000. At the present time, the almost all types of multiarmed and multicomponent miktoarm star polymers have become feasible by using recently developed iterative strategy. For example, the following well-defined stars have been successfully synthesized: 3-arm ABC, 4-arm ABCD, 5-arm ABCDE, 6-arm ABCDEF, 7-arm ABCDEFG, 6-arm ABC, 9-arm ABC, 12-arm ABC, 13-arm ABCD, 9-arm AB, 17-arm AB, 33-arm AB, 7-arm ABC, 15-arm ABCD, and 31-arm ABCDE miktoarm star polymers, most of which are quite new and difficult to synthesize by the end of the 1990s. Several new specialty functional star polymers composed of vinyl polymer segments and rigid rodlike poly(acetylene) arms, helical polypeptide, or helical poly(hexyl isocyanate) arms are introduced.

Bringing parenting interventions back to the future: How randomized microtrials may benefit parenting intervention efficacy

NARCIS (Netherlands)

Leijten, P.; Dishion, T.J.; Thomaes, S.; Raaijmakers, M.A.J.; Orobio de Castro, B.; Matthys, W.

2015-01-01

A novel approach is needed to promote the efficacy of parenting interventions designed to improve children's mental health. The proposed approach bridges developmental and intervention science to test which intervention elements contribute to parenting intervention program efficacy. The approach

Parents' perspectives on a collaborative approach to the application of the Handwriting Without Tears(®) programme with children with Down syndrome.

Science.gov (United States)

Patton, Sandra; Hutton, Eve

2016-08-01

The active involvement of parents and children in goal setting and intervention is integral to contemporary occupational therapy process models. However, parental perspectives on collaborative handwriting intervention are limited. This paper presents parental perspectives on a three-way collaboration involving teachers, parents and an occupational therapist in the application of Handwriting Without Tears(®) (HWT(®) ) with children with Down syndrome. Within a larger mixed methods study, 44 parents completed purpose-designed questionnaires and six parents participated in a focus group, post 8 months of programme implementation. Both methods gathered parent's perspectives on the usefulness and limitations of applying HWT(®) . The focus group explored collaboration in depth. Analysis involved triangulation of data from descriptive analysis of numerical data with content analysis of open-ended questions and focus group data. Enablers of parent-child engagement in HWT(®) were identified as; the parent-child-friendly aspects of HWT(®) , the teacher involvement ensuring continuity which eased demands on parents, the ongoing support/guidance of the occupational therapist and the child's involvement in HWT(®) group intervention. The occupational therapists' involvement was reported as essential to encouraging teacher/parent involvement. Barriers to child-parent engagement included fluctuations in child health, mood, attention span and time limitations including the child's involvement in other therapy programmes. Parents perceived the HWT(®) and the three-way collaborative approach as enabling active parent-child engagement in handwriting intervention. This approach warrants further investigation. Findings have the potential to inform practice guidelines and pre- and post-graduation education related to collaborative handwriting intervention with children with Down syndrome and their families. © 2016 Occupational Therapy Australia.

A weight limit emerges for neutron stars

Science.gov (United States)

Cho, Adrian

2018-02-01

Astrophysicists have long wondered how massive a neutron star—the corpse of certain exploding stars—could be without collapsing under its own gravity to form a black hole. Now, four teams have independently deduced a mass limit for neutron stars of about 2.2 times the mass of the sun. To do so, all four groups analyzed last year's blockbuster observations of the merger of two neutron stars, spied on 17 September 2017 by dozens of observatories. That approach may seem unpromising, as it might appear that the merging neutron stars would have immediately produced a black hole. However, the researchers argue that the merger first produced a spinning, overweight neutron star momentarily propped up by centrifugal force. They deduce that just before it collapsed, the short-lived neutron star had to be near the maximum mass for one spinning as a solid body. That inference allowed them to use a scaling relationship to estimate the maximum mass of a nonrotating, stable neutron star, starting from the total mass of the original pair and the amount of matter spewed into space.

Statistical investigation of flare stars. III. Flare stars in the general galactic star field

International Nuclear Information System (INIS)

Mirzoyan, L.V.; Ambaryan, V.V.; Garibdzhanyan, A.T.; Mirzoyan, A.L.

1989-01-01

Some questions relating to the existence of a large number of flare stars in the general star field of the Galaxy are discussed. It is shown that only a small proportion of them can be found by photographic observations, and the fraction of field flare stars among such stars found in the regions of star clusters and associations does not exceed 10%. The ratio of the numbers of flare stars of the foreground and the background for a particular system depends on its distance, reaching zero at a distance of about 500 pc. The spatial density of flare stars in the Pleiades is at least two orders of magnitude greater than in the general galactic field. A lower limit for the number of flare stars in the Galaxy is estimated at 4.2 ·10 9 , and the number of nonflare red dwarfs at 2.1·10 10 . There are grounds for believing that they were all formed in star clusters and associations

Parenting and Child Development in Adoptive Families: Does Parental Sexual Orientation Matter?

OpenAIRE

Farr, Rachel H.; Forssell, Stephen L.; Patterson, Charlotte J.

2010-01-01

This study, funded by Williams Institute, investigated child development and parenting in 106 families headed by 27 lesbian, 29 gay, and 50 heterosexual couples with young adopted children. Parents and teachers reported that, on average, children were developing in typical ways. Measures of children’s adjustment, parenting approaches, parenting stress, and couple relationship adjustment were not significantly associated with parental sexual orientation. However, several family process variabl...

Symbiotic stars

International Nuclear Information System (INIS)

Boyarchuk, A.A.

1975-01-01

There are some arguments that the symbiotic stars are binary, where one component is a red giant and the other component is a small hot star which is exciting a nebula. The symbiotic stars belong to the old disc population. Probably, symbiotic stars are just such an evolutionary stage for double stars as planetary nebulae for single stars. (Auth.)

An exploration of Singaporean parental experiences in managing school-aged children's postoperative pain: a descriptive qualitative approach.

Science.gov (United States)

Lim, Siew Hoon; Mackey, Sandra; Liam, Joanne Li Wee; He, Hong-Gu

2012-03-01

To enhance understanding of the experience of parents in managing their children's postoperative pain in Singapore. Parents play a significant role in their hospitalised child's postoperative pain care. Their active involvement may contribute to accurate pain assessment and effective pain management for their child. However, there is a lack of in-depth research exploring the experience of parents involved in their children's postoperative pain management. This study adopted a descriptive qualitative approach, which is situated in the interpretive paradigm. Semi-structured interviews were conducted to collect data from 14 parents whose children were hospitalised in one of the three paediatric surgical wards in a hospital in Singapore in December 2009. Thematic analysis was used to analyse the data. Three themes were identified: 'Actions used by parents to alleviate their child's postoperative pain', 'Factors influencing parents' management of their child's postoperative pain' and 'Parents' needs in the process of caring for their child's postoperative pain'. Parents used a range of non-pharmacological pain relief interventions for their child. Parental roles and expectations, bond between parent and child, support from nurses, family and own religious beliefs, as well as children's age and maturity level were factors which promoted parental participation, whereas parents' negative feelings, knowledge deficit and nurses' busy schedule were hindering factors. Parents expressed needs for more involvement in their child's care, adequate rest and information support from nurses. This study highlights the importance of involving parents in their child's postoperative pain management. It provides evidence for health care professionals to pay attention to factors that may influence parental participation and, therefore, guide their practice. Nurses need to provide parents with support and education to facilitate their roles and improve their child's postoperative pain

Effects of Neutron-Star Dynamic Tides on Gravitational Waveforms within the Effective-One-Body Approach.

Science.gov (United States)

Hinderer, Tanja; Taracchini, Andrea; Foucart, Francois; Buonanno, Alessandra; Steinhoff, Jan; Duez, Matthew; Kidder, Lawrence E; Pfeiffer, Harald P; Scheel, Mark A; Szilagyi, Bela; Hotokezaka, Kenta; Kyutoku, Koutarou; Shibata, Masaru; Carpenter, Cory W

2016-05-06

Extracting the unique information on ultradense nuclear matter from the gravitational waves emitted by merging neutron-star binaries requires robust theoretical models of the signal. We develop a novel effective-one-body waveform model that includes, for the first time, dynamic (instead of only adiabatic) tides of the neutron star as well as the merger signal for neutron-star-black-hole binaries. We demonstrate the importance of the dynamic tides by comparing our model against new numerical-relativity simulations of nonspinning neutron-star-black-hole binaries spanning more than 24 gravitational-wave cycles, and to other existing numerical simulations for double neutron-star systems. Furthermore, we derive an effective description that makes explicit the dependence of matter effects on two key parameters: tidal deformability and fundamental oscillation frequency.

Effects of Neutron-Star Dynamic Tides on Gravitational Waveforms within the Effective-One-Body Approach

Science.gov (United States)

Hinderer, Tanja; Taracchini, Andrea; Foucart, Francois; Buonanno, Alessandra; Steinhoff, Jan; Duez, Matthew; Kidder, Lawrence E.; Pfeiffer, Harald P.; Scheel, Mark A.; Szilagyi, Bela; Hotokezaka, Kenta; Kyutoku, Koutarou; Shibata, Masaru; Carpenter, Cory W.

2016-05-01

Extracting the unique information on ultradense nuclear matter from the gravitational waves emitted by merging neutron-star binaries requires robust theoretical models of the signal. We develop a novel effective-one-body waveform model that includes, for the first time, dynamic (instead of only adiabatic) tides of the neutron star as well as the merger signal for neutron-star-black-hole binaries. We demonstrate the importance of the dynamic tides by comparing our model against new numerical-relativity simulations of nonspinning neutron-star-black-hole binaries spanning more than 24 gravitational-wave cycles, and to other existing numerical simulations for double neutron-star systems. Furthermore, we derive an effective description that makes explicit the dependence of matter effects on two key parameters: tidal deformability and fundamental oscillation frequency.

Common Warm Dust Temperatures Around Main Sequence Stars

Science.gov (United States)

Morales, Farisa; Rieke, George; Werner, Michael; Stapelfeldt, Karl; Bryden, Geoffrey; Su, Kate

2011-01-01

We compare the properties of warm dust emission from a sample of main-sequence A-type stars (B8-A7) to those of dust around solar-type stars (F5-KO) with similar Spitzer Space Telescope Infrared Spectrograph/MIPS data and similar ages. Both samples include stars with sources with infrared spectral energy distributions that show evidence of multiple components. Over the range of stellar types considered, we obtain nearly the same characteristic dust temperatures (∼ 190 K and ∼60 K for the inner and outer dust components, respectively)-slightly above the ice evaporation temperature for the inner belts. The warm inner dust temperature is readily explained if populations of small grains are being released by sublimation of ice from icy planetesimals. Evaporation of low-eccentricity icy bodies at ∼ 150 K can deposit particles into an inner/warm belt, where the small grains are heated to dust Temperatures of -190 K. Alternatively, enhanced collisional processing of an asteroid belt-like system of parent planetesimals just interior to the snow line may account for the observed uniformity in dust temperature. The similarity in temperature of the warmer dust across our B8-KO stellar sample strongly suggests that dust-producing planetesimals are not found at similar radial locations around all stars, but that dust production is favored at a characteristic temperature horizon.

Promoting positive parenting: an annotated bibliography.

Science.gov (United States)

Ahmann, Elizabeth

2002-01-01

Positive parenting is built on respect for children and helps develop self-esteem, inner discipline, self-confidence, responsibility, and resourcefulness. Positive parenting is also good for parents: parents feel good about parenting well. It builds a sense of dignity. Positive parenting can be learned. Understanding normal development is a first step, so that parents can distinguish common behaviors in a stage of development from "problems." Central to positive parenting is developing thoughtful approaches to child guidance that can be used in place of anger, manipulation, punishment, and rewards. Support for developing creative and loving approaches to meet special parenting challenges, such as temperament, disabilities, separation and loss, and adoption, is sometimes necessary as well. This annotated bibliography offers resources to professionals helping parents and to parents wishing to develop positive parenting skills.

Relaxation near Supermassive Black Holes Driven by Nuclear Spiral Arms: Anisotropic Hypervelocity Stars, S-stars, and Tidal Disruption Events

Energy Technology Data Exchange (ETDEWEB)

Hamers, Adrian S. [Institute for Advanced Study, School of Natural Sciences, Einstein Drive, Princeton, NJ 08540 (United States); Perets, Hagai B., E-mail: hamers@ias.edu [Technion—Israel Institute of Technology, Haifa 32000 (Israel)

2017-09-10

Nuclear spiral arms are small-scale transient spiral structures found in the centers of galaxies. Similarly to their galactic-scale counterparts, nuclear spiral arms can perturb the orbits of stars. In the case of the Galactic center (GC), these perturbations can affect the orbits of stars and binaries in a region extending to several hundred parsecs around the supermassive black hole (SMBH), causing diffusion in orbital energy and angular momentum. This diffusion process can drive stars and binaries to close approaches with the SMBH, disrupting single stars in tidal disruption events (TDEs), or disrupting binaries, leaving a star tightly bound to the SMBH and an unbound star escaping the galaxy, i.e., a hypervelocity star (HVS). Here, we consider diffusion by nuclear spiral arms in galactic nuclei, specifically the Milky Way GC. We determine nuclear-spiral-arm-driven diffusion rates using test-particle integrations and compute disruption rates. Our TDE rates are up to 20% higher compared to relaxation by single stars. For binaries, the enhancement is up to a factor of ∼100, and our rates are comparable to the observed numbers of HVSs and S-stars. Our scenario is complementary to relaxation driven by massive perturbers. In addition, our rates depend on the inclination of the binary with respect to the Galactic plane. Therefore, our scenario provides a novel potential source for the observed anisotropic distribution of HVSs. Nuclear spiral arms may also be important for accelerating the coalescence of binary SMBHs and for supplying nuclear star clusters with stars and gas.

Quark core stars, quark stars and strange stars

International Nuclear Information System (INIS)

Grassi, F.

1988-01-01

A recent one flavor quark matter equation of state is generalized to several flavors. It is shown that quarks undergo a first order phase transition. In addition, this equation of state depends on just one parameter in the two flavor case, two parameters in the three flavor case, and these parameters are constrained by phenomenology. This equation of state is then applied to the hadron-quark transition in neutron stars and the determination of quark star stability, the investigation of strange matter stability and possible strange star existence. 43 refs., 6 figs

Star pattern recognition algorithm aided by inertial information

Science.gov (United States)

Liu, Bao; Wang, Ke-dong; Zhang, Chao

2011-08-01

Star pattern recognition is one of the key problems of the celestial navigation. The traditional star pattern recognition approaches, such as the triangle algorithm and the star angular distance algorithm, are a kind of all-sky matching method whose recognition speed is slow and recognition success rate is not high. Therefore, the real time and reliability of CNS (Celestial Navigation System) is reduced to some extent, especially for the maneuvering spacecraft. However, if the direction of the camera optical axis can be estimated by other navigation systems such as INS (Inertial Navigation System), the star pattern recognition can be fulfilled in the vicinity of the estimated direction of the optical axis. The benefits of the INS-aided star pattern recognition algorithm include at least the improved matching speed and the improved success rate. In this paper, the direction of the camera optical axis, the local matching sky, and the projection of stars on the image plane are estimated by the aiding of INS firstly. Then, the local star catalog for the star pattern recognition is established in real time dynamically. The star images extracted in the camera plane are matched in the local sky. Compared to the traditional all-sky star pattern recognition algorithms, the memory of storing the star catalog is reduced significantly. Finally, the INS-aided star pattern recognition algorithm is validated by simulations. The results of simulations show that the algorithm's computation time is reduced sharply and its matching success rate is improved greatly.

MASSIVE INFANT STARS ROCK THEIR CRADLE

Science.gov (United States)

2002-01-01

Extremely intense radiation from newly born, ultra-bright stars has blown a glowing spherical bubble in the nebula N83B, also known as NGC 1748. A new NASA Hubble Space Telescope image has helped to decipher the complex interplay of gas and radiation of a star-forming region in a nearby galaxy. The image graphically illustrates just how these massive stars sculpt their environment by generating powerful winds that alter the shape of the parent gaseous nebula. These processes are also seen in our Milky Way in regions like the Orion Nebula. The Hubble telescope is famous for its contribution to our knowledge about star formation in very distant galaxies. Although most of the stars in the Universe were born several billions of years ago, when the Universe was young, star formation still continues today. This new Hubble image shows a very compact star-forming region in a small part of one of our neighboring galaxies - the Large Magellanic Cloud. This galaxy lies only 165,000 light-years from our Milky Way and can easily be seen with the naked eye from the Southern Hemisphere. Young, massive, ultra-bright stars are seen here just as they are born and emerge from the shelter of their pre-natal molecular cloud. Catching these hefty stars at their birthplace is not as easy as it may seem. Their high mass means that the young stars evolve very rapidly and are hard to find at this critical stage. Furthermore, they spend a good fraction of their youth hidden from view, shrouded by large quantities of dust in a molecular cloud. The only chance is to observe them just as they start to emerge from their cocoon - and then only with very high-resolution telescopes. Astronomers from France, the U.S., and Germany have used Hubble to study the fascinating interplay between gas, dust, and radiation from the newly born stars in this nebula. Its peculiar and turbulent structure has been revealed for the first time. This high-resolution study has also uncovered several individual stars

Kinematic and spatial distributions of barium stars - are the barium stars and Am stars related?

International Nuclear Information System (INIS)

Hakkila, J.

1989-01-01

The possibility of an evolutionary link between Am stars and barium stars is considered, and an examination of previous data suggests that barium star precursors are main-sequence stars of intermediate mass, are most likely A and/or F dwarfs, and are intermediate-mass binaries with close to intermediate orbital separations. The possible role of mass transfer in the later development of Am systems is explored. Mass transfer and loss from systems with a range of masses and orbital separations may explain such statistical peculiarities of barium stars as the large dispersion in absolute magnitude, the large range of elemental abundances from star to star, and the small number of stars with large peculiar velocities. 93 refs

Asymmetric nuclear matter and neutron star properties within the extended Brueckner theory

Energy Technology Data Exchange (ETDEWEB)

Hassaneen, Khaled S.A. [Sohag University, Physics Department, Faculty of Science, Sohag (Egypt); Taif University, Physics Department, Faculty of Science, Taif (Saudi Arabia)

2017-01-15

Microscopically, the equation of state (EOS) and other properties of asymmetric nuclear matter at zero temperature have been investigated extensively by adopting the non-relativistic Brueckner-Hartree-Fock (BHF) and the extended BHF approaches by using the self-consistent Green's function approach or by including a phenomenological three-body force. Once three-body forces are introduced, the phenomenological saturation point is reproduced and the theory is applied to the study of neutron star properties. We can calculate the total mass and radius for neutron stars using various equations of state at high densities in β-equilibrium without hyperons. A comparison with other microscopic predictions based on non-relativistic and density-dependent relativistic mean-field calculations has been done. It is found that relativistic EOS yields however larger mass and radius for neutron star than predictions based on non-relativistic approaches. Also the three-body force plays a crucial role to deduce the theoretical value of the maximum mass of neutron stars in agreement with recent measurements of the neutron star mass. (orig.)

Massive stars, x-ray ridge, and galactic 26Al gamma-ray line emission

International Nuclear Information System (INIS)

Montmerle, T.

1986-07-01

Massive stars interact with their parent molecular cloud by means of their ionizing flux and strong winds, thereby creating giant, hollow HII regions. To account for the observed structure of these HII regions, it appears necessary that all the wind energy be dissipated. Dorland and Montmerle have recently proposed a new dissipation mechanism, in the process, diffuse hard X-rays are emitted. If the observed galactic X-ray ''ridge'' results from this process on a galactic scale, it can be accounted for by the interaction of ∼3000 Wolf-Rayet stars (mostly within a ∼6.5 kpc ring) with their surrounding interstellar gas. This result is essentially consistent with the suggestion by Prantzos and Casse that the galactic 26 Al γ-ray line emission originates in Wolf-Rayet stars

Order parameter analysis of synchronization transitions on star networks

Science.gov (United States)

Chen, Hong-Bin; Sun, Yu-Ting; Gao, Jian; Xu, Can; Zheng, Zhi-Gang

2017-12-01

The collective behaviors of populations of coupled oscillators have attracted significant attention in recent years. In this paper, an order parameter approach is proposed to study the low-dimensional dynamical mechanism of collective synchronizations, by adopting the star-topology of coupled oscillators as a prototype system. The order parameter equation of star-linked phase oscillators can be obtained in terms of the Watanabe-Strogatz transformation, Ott-Antonsen ansatz, and the ensemble order parameter approach. Different solutions of the order parameter equation correspond to the diverse collective states, and different bifurcations reveal various transitions among these collective states. The properties of various transitions in the star-network model are revealed by using tools of nonlinear dynamics such as time reversibility analysis and linear stability analysis.

Parental alienation and the Brazilian justice system: an empirical approach

Directory of Open Access Journals (Sweden)

Mariana Cunha de Andrade

2016-08-01

Full Text Available This research addresses the judiciary's role in the conflict resolution involving parental alienation. How the judiciary faces the allegations of parental alienation or sexual abuse? What is the predominant gender of alienating parents? What acts of parental alienation are alleged by the parties? Which measures the judges take to avoid parental alienation? The answers to these questions are gathered using an empirical research. For this purpose, we performed a data collection of cases involving parental alienation in the Courts of Appeal in the states of São Paulo and Minas Gerais, between 2009 and 2014. It is a demographic and quantitative empirical study that seeks to provide an overview of actions involving the parental alienation phenomenon.

Star Formation in Merging Galaxies Using FIRE

Science.gov (United States)

Perez, Adrianna; Hung, Chao-Ling; Naiman, Jill; Moreno, Jorge; Hopkins, Philip

2018-01-01

Galaxy interactions and mergers are efficient mechanisms to birth stars at rates that are significantly higher than found in our Milky Way galaxy. The Kennicut-Schmidt (KS) relation is an empirical relationship between the star-forming rate and gas surface densities of galaxies (Schmidt 1959; Kennicutt 1998). Although most galaxies follow the KS relation, the high levels of star formation in galaxy mergers places them outside of this otherwise tight relationship. The goal of this research is to analyze the gas content and star formation of simulated merging galaxies. Our work utilizes the Feedback In Realistic Environments (FIRE) model (Hopkins et al., 2014). The FIRE project is a high-resolution cosmological simulation that resolves star-forming regions and incorporates stellar feedback in a physically realistic way. In this work, we have noticed a significant increase in the star formation rate at first and second passage, when the two black holes of each galaxy approach one other. Next, we will analyze spatially resolved star-forming regions over the course of the interacting system. Then, we can study when and how the rates that gas converts into stars deviate from the standard KS. These analyses will provide important insights into the physical mechanisms that regulate star formation of normal and merging galaxies and valuable theoretical predictions that can be used to compare with current and future observations from ALMA or the James Webb Space Telescope.

Infra-red data of extended sources as a measure of the star formation rate

International Nuclear Information System (INIS)

Puget, J.-L.

1985-01-01

Molecular cloud complexes are gravitationally bound systems which contain molecular clouds, HII regions and possibly OB associations after they evaporated their parent cloud. A large fraction of the energy (50%) radiated by the O and B stars is converted into infra-red. Less massive stars still embedded in molecular clouds or still in their vicinity will also see most of their radiation absorbed by dust and reemitted in the infra-red. The two quantities the author deduces directly from the data are: the ratio of the far-infra-red luminosity due to recently formed stars to the mass of gas, as a measure of the star formation rate; and the infra-red excess (IRE): the ratio of the far-infra-red luminosity to the luminosity of HII regions in the Lyman α line, which gives information on the initial mass function. Finally he discusses the possible links between star formation and some of the relevant physical conditions in the molecular clouds: amount and temperature distribution of dust. (Auth.)

The thermodynamics of molecular cloud fragmentation : Star formation under non-Milky Way conditions

NARCIS (Netherlands)

Hocuk, S.; Spaans, M.

Context. Properties of candidate stars, forming out of molecular clouds, depend on the ambient conditions of the parent cloud. We present a series of 2D and 3D simulations of fragmentation of molecular clouds in starburst regions, as well as of clouds under conditions in dwarf galaxies, leading to

The Rose-red Glow of Star Formation

Science.gov (United States)

2011-03-01

The vivid red cloud in this new image from ESO's Very Large Telescope is a region of glowing hydrogen surrounding the star cluster NGC 371. This stellar nursery lies in our neighbouring galaxy, the Small Magellanic Cloud. The object dominating this image may resemble a pool of spilled blood, but rather than being associated with death, such regions of ionised hydrogen - known as HII regions - are sites of creation with high rates of recent star birth. NGC 371 is an example of this; it is an open cluster surrounded by a nebula. The stars in open clusters all originate from the same diffuse HII region, and over time the majority of the hydrogen is used up by star formation, leaving behind a shell of hydrogen such as the one in this image, along with a cluster of hot young stars. The host galaxy to NGC 371, the Small Magellanic Cloud, is a dwarf galaxy a mere 200 000 light-years away, which makes it one of the closest galaxies to the Milky Way. In addition, the Small Magellanic Cloud contains stars at all stages of their evolution; from the highly luminous young stars found in NGC 371 to supernova remnants of dead stars. These energetic youngsters emit copious amounts of ultraviolet radiation causing surrounding gas, such as leftover hydrogen from their parent nebula, to light up with a colourful glow that extends for hundreds of light-years in every direction. The phenomenon is depicted beautifully in this image, taken using the FORS1 instrument on ESO's Very Large Telescope (VLT). Open clusters are by no means rare; there are numerous fine examples in our own Milky Way. However, NGC 371 is of particular interest due to the unexpectedly large number of variable stars it contains. These are stars that change in brightness over time. A particularly interesting type of variable star, known as slowly pulsating B stars, can also be used to study the interior of stars through asteroseismology [1], and several of these have been confirmed in this cluster. Variable stars

A new Wolf-Rayet star and its circumstellar nebula in Aquila

Science.gov (United States)

Gvaramadze, V. V.; Kniazev, A. Y.; Hamann, W.-R.; Berdnikov, L. N.; Fabrika, S.; Valeev, A. F.

2010-04-01

We report the discovery of a new Wolf-Rayet star in Aquila via detection of its circumstellar nebula (reminiscent of ring nebulae associated with late WN stars) using the Spitzer Space Telescope archival data. Our spectroscopic follow-up of the central point source associated with the nebula showed that it is a WN7h star (we named it WR121b). We analysed the spectrum of WR121b by using the Potsdam Wolf-Rayet model atmospheres, obtaining a stellar temperature of ~=50kK. The stellar wind composition is dominated by helium with ~20 per cent of hydrogen. The stellar spectrum is highly reddened [E(B - V) = 2.85mag]. Adopting an absolute magnitude of Mv = -5.7, the star has a luminosity of logL/Lsolar = 5.75 and a mass-loss rate of 10-4.7Msolaryr-1, and resides at a distance of 6.3kpc. We searched for a possible parent cluster of WR121b and found that this star is located at ~=1° from the young star cluster embedded in the giant HII region W43 (containing a WN7+a/OB? star - WR121a). We also discovered a bow shock around the O9.5III star ALS9956, located at from the cluster. We discuss the possibility that WR121b and ALS9956 are runaway stars ejected from the cluster in W43. Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie Heidelberg and the Instituto de Astrofísica de Andalucía (CSIC). E-mail: vgvaram@mx.iki.rssi.ru (VVG); akniazev@saao.ac.za (AYK); wrh@astro.physik.uni-potsdam.de (WRH); berdnik@sai.msu.ru (LNB); fabrika@sao.ru (SF); azamat@sao.ru (AFV)

Cyclotron Lines in Accreting Neutron Star Spectra

Science.gov (United States)

Wilms, Jörn; Schönherr, Gabriele; Schmid, Julia; Dauser, Thomas; Kreykenbohm, Ingo

2009-05-01

Cyclotron lines are formed through transitions of electrons between discrete Landau levels in the accretion columns of accreting neutron stars with strong (1012 G) magnetic fields. We summarize recent results on the formation of the spectral continuum of such systems, describe recent advances in the modeling of the lines based on a modification of the commonly used Monte Carlo approach, and discuss new results on the dependence of the measured cyclotron line energy from the luminosity of transient neutron star systems. Finally, we show that Simbol-X will be ideally suited to build and improve the observational database of accreting and strongly magnetized neutron stars.

I-Love-Q relations: from compact stars to black holes

International Nuclear Information System (INIS)

Yagi, Kent; Yunes, Nicolás

2016-01-01

The relations between most observables associated with a compact star, such as the mass and radius of a neutron star or a quark star, typically depend strongly on their unknown internal structure. The recently discovered I-Love-Q relations (between the moment of inertia, the tidal deformability and the quadrupole moment) are however approximately insensitive to this structure. These relations become exact for stationary black holes (BHs) in General Relativity as shown by the no-hair theorems, mainly because BHs are vacuum solutions with event horizons. In this paper, we take the first steps toward studying how the approximate I-Love-Q relations become exact in the limit as compact stars become BHs. To do so, we consider a toy model for compact stars, i.e. incompressible stars with anisotropic pressure, which allows us to model an equilibrium sequence of stars with ever increasing compactness that approaches the BH limit arbitrarily closely. We numerically construct such a sequence in the slow-rotation and in the small-tide approximations by extending the Hartle–Thorne formalism, and then extract the I-Love-Q trio from the asymptotic behavior of the metric tensor at spatial infinity. We find that the I-Love-Q relations approach the BH limit in a nontrivial way, with the quadrupole moment and the tidal deformability changing sign as the compactness and the amount of anisotropy are increased. Through a generalization of Maclaurin spheroids to anisotropic stars, we show that the multipole moments also change sign in the Newtonian limit as the amount of anisotropy is increased because the star becomes prolate. We also prove analytically that the stellar moment of inertia reaches the BH limit as the compactness reaches a critical BH value in the strongly anisotropic limit. Modeling the BH limit through a sequence of anisotropic stars, however, can fail when considering other theories of gravity. We calculate the scalar dipole charge and the moment of inertia in a

Young stellar population and star formation history ofW4 HII region/Cluster Complex

Science.gov (United States)

Panwar, Neelam

2018-04-01

The HII region/cluster complex has been a subject of numerous investigations to study the feedback effect of massive stars on their surroundings. Massive stars not only alter the morphology of the parental molecular clouds, but also influence star formation, circumstellar disks and the mass function of low-mass stars in their vicinity. However, most of the studies of low-mass stellar content of the HII regions are limited only to the nearby regions. We study the star formation in the W4 HII region using deep optical observations obtained with the archival data from Canada - France - Hawaii Telescope, Two-Micron All Sky Survey, Spitzer, Herschel and Chandra. We investigate the spatial distribution of young stellar objects in the region, their association with the remnant molecular clouds, and search for the clustering to establish the sites of recent star formation. Our analysis suggests that the influence of massive stars on circumstellar disks is significant only to thei! r immediate neighborhood. The spatial correlation of the young stars with the distribution of gas and dust of the complex indicate that the clusters would have formed in a large filamentary cloud. The observing facilities at the 3.6-m Devasthal Optical Telescope (DOT), providing high-resolution spectral and imaging capabilities, will fulfill the major objectives in the study of HII regions.

Galactic Doppelgängers: The Chemical Similarity Among Field Stars and Among Stars with a Common Birth Origin

Science.gov (United States)

Ness, M.; Rix, H.-W.; Hogg, David W.; Casey, A. R.; Holtzman, J.; Fouesneau, M.; Zasowski, G.; Geisler, D.; Shetrone, M.; Minniti, D.; Frinchaboy, Peter M.; Roman-Lopes, Alexandre

2018-02-01

We explore to what extent stars within Galactic disk open clusters resemble each other in the high-dimensional space of their photospheric element abundances and contrast this with pairs of field stars. Our analysis is based on abundances for 20 elements, homogeneously derived from APOGEE spectra (with carefully quantified uncertainties of typically 0.03 dex). We consider 90 red giant stars in seven open clusters and find that most stars within a cluster have abundances in most elements that are indistinguishable (in a {χ }2-sense) from those of the other members, as expected for stellar birth siblings. An analogous analysis among pairs of > 1000 field stars shows that highly significant abundance differences in the 20 dimensional space can be established for the vast majority of these pairs, and that the APOGEE-based abundance measurements have high discriminating power. However, pairs of field stars whose abundances are indistinguishable even at 0.03 dex precision exist: ∼0.3% of all field star pairs and ∼1.0% of field star pairs at the same (solar) metallicity [Fe/H] = 0 ± 0.02. Most of these pairs are presumably not birth siblings from the same cluster, but rather doppelgängers. Our analysis implies that “chemical tagging” in the strict sense, identifying birth siblings for typical disk stars through their abundance similarity alone, will not work with such data. However, our approach shows that abundances have extremely valuable information for probabilistic chemo-orbital modeling, and combined with velocities, we have identified new cluster members from the field.

Variations in Perceived Parenting Education Preferences: A Person-Centred Approach

Science.gov (United States)

Kim, YaeBin

2015-01-01

Parenting education needs assessment surveys were collected from a large group of the parents or caregivers of 698 0-5-year-old children in southern Nevada. Survey questions addressed parenting education interests, family characteristics, and preferred delivery methods of parenting education. Cluster analysis was used to empirically determine if…

Star marketer’s impact on the market strategy choice

Directory of Open Access Journals (Sweden)

Vlašić Goran

2017-01-01

Full Text Available We focus on understanding the role of star marketers in pursuing a market-driven vs. a market-driving strategy. Results indicate that market-driving and market-driven strategies are two approaches that can be pursued by market-oriented firms. A star marketer has a robust positive influence on market-driving strategy. In contrast, a star marketer has no meaningful influence on market-driven strategy. In short, while star marketers are very important for market-driving strategy and long term success, they represent an unnecessary cost and provide no added value to companies focusing on market-driven strategies and short term results.

Single event and TREE latchup mitigation for a star tracker sensor: An innovative approach to system level latchup mitigation

International Nuclear Information System (INIS)

Kimbrough, J.R.; Colella, N.J.; Davis, R.W.; Bruener, D.B.; Coakley, P.G.; Lutjens, S.W.; Mallon, C.E.

1994-08-01

Electronic packages designed for spacecraft should be fault-tolerant and operate without ground control intervention through extremes in the space radiation environment. If designed for military use, the electronics must survive and function in a nuclear radiation environment. This paper presents an innovative ''blink'' approach rather than the typical ''operate through'' approach to achieve system level latchup mitigation on a prototype star tracker camera. Included are circuit designs, flash x-ray test data, and heavy ion data demonstrating latchup mitigation protecting micro-electronics from current latchup and burnout due to Single Event Latchup (SEL) and Transient Radiation Effects on Electronics (TREE)

Young star clusters in nearby molecular clouds

Science.gov (United States)

Getman, K. V.; Kuhn, M. A.; Feigelson, E. D.; Broos, P. S.; Bate, M. R.; Garmire, G. P.

2018-06-01

The SFiNCs (Star Formation in Nearby Clouds) project is an X-ray/infrared study of the young stellar populations in 22 star-forming regions with distances ≲ 1 kpc designed to extend our earlier MYStIX (Massive Young Star-Forming Complex Study in Infrared and X-ray) survey of more distant clusters. Our central goal is to give empirical constraints on cluster formation mechanisms. Using parametric mixture models applied homogeneously to the catalogue of SFiNCs young stars, we identify 52 SFiNCs clusters and 19 unclustered stellar structures. The procedure gives cluster properties including location, population, morphology, association with molecular clouds, absorption, age (AgeJX), and infrared spectral energy distribution (SED) slope. Absorption, SED slope, and AgeJX are age indicators. SFiNCs clusters are examined individually, and collectively with MYStIX clusters, to give the following results. (1) SFiNCs is dominated by smaller, younger, and more heavily obscured clusters than MYStIX. (2) SFiNCs cloud-associated clusters have the high ellipticities aligned with their host molecular filaments indicating morphology inherited from their parental clouds. (3) The effect of cluster expansion is evident from the radius-age, radius-absorption, and radius-SED correlations. Core radii increase dramatically from ˜0.08 to ˜0.9 pc over the age range 1-3.5 Myr. Inferred gas removal time-scales are longer than 1 Myr. (4) Rich, spatially distributed stellar populations are present in SFiNCs clouds representing early generations of star formation. An appendix compares the performance of the mixture models and non-parametric minimum spanning tree to identify clusters. This work is a foundation for future SFiNCs/MYStIX studies including disc longevity, age gradients, and dynamical modelling.

Modelling ultraviolet-line diagnostics of stars, the ionized and the neutral interstellar medium in star-forming galaxies

Science.gov (United States)

Vidal-García, A.; Charlot, S.; Bruzual, G.; Hubeny, I.

2017-09-01

We combine state-of-the-art models for the production of stellar radiation and its transfer through the interstellar medium (ISM) to investigate ultraviolet-line diagnostics of stars, the ionized and the neutral ISM in star-forming galaxies. We start by assessing the reliability of our stellar population synthesis modelling by fitting absorption-line indices in the ISM-free ultraviolet spectra of 10 Large Magellanic Cloud clusters. In doing so, we find that neglecting stochastic sampling of the stellar initial mass function in these young (∼10-100 Myr), low-mass clusters affects negligibly ultraviolet-based age and metallicity estimates but can lead to significant overestimates of stellar mass. Then, we proceed and develop a simple approach, based on an idealized description of the main features of the ISM, to compute in a physically consistent way the combined influence of nebular emission and interstellar absorption on ultraviolet spectra of star-forming galaxies. Our model accounts for the transfer of radiation through the ionized interiors and outer neutral envelopes of short-lived stellar birth clouds, as well as for radiative transfer through a diffuse intercloud medium. We use this approach to explore the entangled signatures of stars, the ionized and the neutral ISM in ultraviolet spectra of star-forming galaxies. We find that, aside from a few notable exceptions, most standard ultraviolet indices defined in the spectra of ISM-free stellar populations are prone to significant contamination by the ISM, which increases with metallicity. We also identify several nebular-emission and interstellar-absorption features, which stand out as particularly clean tracers of the different phases of the ISM.

Constraining neutron star matter with Quantum Chromodynamics

CERN Document Server

Kurkela, Aleksi; Schaffner-Bielich, Jurgen; Vuorinen, Aleksi

2014-01-01

In recent years, there have been several successful attempts to constrain the equation of state of neutron star matter using input from low-energy nuclear physics and observational data. We demonstrate that significant further restrictions can be placed by additionally requiring the pressure to approach that of deconfined quark matter at high densities. Remarkably, the new constraints turn out to be highly insensitive to the amount --- or even presence --- of quark matter inside the stars.

Entropy-induced separation of star polymers in porous media

International Nuclear Information System (INIS)

Blavats'ka, V.; Ferber, C. von; Holovatch, Yu.

2006-01-01

We present a quantitative picture of the separation of star polymers in a solution where part of the volume is influenced by a porous medium. To this end, we study the impact of long-range-correlated quenched disorder on the entropy and scaling properties of f-arm star polymers in a good solvent. We assume that the disorder is correlated on the polymer length scale with a power-law decay of the pair correlation function g(r)∼r -a . Applying the field-theoretical renormalization group approach we show in a double expansion in ε=4-d and δ=4-a that there is a range of correlation strengths δ for which the disorder changes the scaling behavior of star polymers. In a second approach we calculate for fixed space dimension d=3 and different values of the correlation parameter a the corresponding scaling exponents γ f that govern entropic effects. We find that γ f -1, the deviation of γ f from its mean field value is amplified by the disorder once we increase δ beyond a threshold. The consequences for a solution of diluted chain and star polymers of equal molecular weight inside a porous medium are that star polymers exert a higher osmotic pressure than chain polymers and in general higher branched star polymers are expelled more strongly from the correlated porous medium. Surprisingly, polymer chains will prefer a stronger correlated medium to a less or uncorrelated medium of the same density while the opposite is the case for star polymers

A Brightness-Referenced Star Identification Algorithm for APS Star Trackers

Science.gov (United States)

Zhang, Peng; Zhao, Qile; Liu, Jingnan; Liu, Ning

2014-01-01

Star trackers are currently the most accurate spacecraft attitude sensors. As a result, they are widely used in remote sensing satellites. Since traditional charge-coupled device (CCD)-based star trackers have a limited sensitivity range and dynamic range, the matching process for a star tracker is typically not very sensitive to star brightness. For active pixel sensor (APS) star trackers, the intensity of an imaged star is valuable information that can be used in star identification process. In this paper an improved brightness referenced star identification algorithm is presented. This algorithm utilizes the k-vector search theory and adds imaged stars' intensities to narrow the search scope and therefore increase the efficiency of the matching process. Based on different imaging conditions (slew, bright bodies, etc.) the developed matching algorithm operates in one of two identification modes: a three-star mode, and a four-star mode. If the reference bright stars (the stars brighter than three magnitude) show up, the algorithm runs the three-star mode and efficiency is further improved. The proposed method was compared with other two distinctive methods the pyramid and geometric voting methods. All three methods were tested with simulation data and actual in orbit data from the APS star tracker of ZY-3. Using a catalog composed of 1500 stars, the results show that without false stars the efficiency of this new method is 4∼5 times that of the pyramid method and 35∼37 times that of the geometric method. PMID:25299950

ABIOTIC O2 LEVELS ON PLANETS AROUND F, G, K, AND M STARS: POSSIBLE FALSE POSITIVES FOR LIFE?

International Nuclear Information System (INIS)

Harman, C. E.; Kasting, J. F.; Schwieterman, E. W.; Schottelkotte, J. C.

2015-01-01

In the search for life on Earth-like planets around other stars, the first (and likely only) information will come from the spectroscopic characterization of the planet's atmosphere. Of the countless number of chemical species terrestrial life produces, only a few have the distinct spectral features and the necessary atmospheric abundance to be detectable. The easiest of these species to observe in Earth's atmosphere is O 2 (and its photochemical byproduct, O 3 ). However, O 2 can also be produced abiotically by photolysis of CO 2 , followed by recombination of O atoms with each other. CO is produced in stoichiometric proportions. Whether O 2 and CO can accumulate to appreciable concentrations depends on the ratio of far-ultraviolet (FUV) to near-ultraviolet (NUV) radiation coming from the planet's parent star and on what happens to these gases when they dissolve in a planet's oceans. Using a one-dimensional photochemical model, we demonstrate that O 2 derived from CO 2 photolysis should not accumulate to measurable concentrations on planets around F- and G-type stars. K-star, and especially M-star planets, however, may build up O 2 because of the low NUV flux from their parent stars, in agreement with some previous studies. On such planets, a “false positive” for life is possible if recombination of dissolved CO and O 2 in the oceans is slow and if other O 2 sinks (e.g., reduced volcanic gases or dissolved ferrous iron) are small. O 3 , on the other hand, could be detectable at UV wavelengths (λ < 300 nm) for a much broader range of boundary conditions and stellar types

Parental overprotection, perceived child vulnerability, and parenting stress: a cross-illness comparison.

Science.gov (United States)

Hullmann, Stephanie E; Wolfe-Christensen, Cortney; Ryan, Jamie L; Fedele, David A; Rambo, Philip L; Chaney, John M; Mullins, Larry L

2010-12-01

The current study sought to investigate differences in parenting capacity variables across four disease groups. Parents (N = 425), the majority of whom were mothers, of children with either cancer, asthma, Type 1 diabetes, or cystic fibrosis, completed measures of parental overprotection, perceived child vulnerability, and parenting stress. After controlling for significant demographic variables, parents of children with cystic fibrosis and asthma reported higher perceived child vulnerability than parents of children with either diabetes or cancer, while parents of children with asthma and diabetes reported higher parenting stress than parents of children with cancer or cystic fibrosis. No differences between disease groups were found for parental overprotection. The current study provides support for an illness-specific approach to understanding parenting capacity variables in the context of childhood chronic illnesses.

Approaching the adolescent-headed family: a review of teen parenting.

Science.gov (United States)

Savio Beers, Lee A; Hollo, Ruth E

2009-10-01

In the USA, as many as 1 in 6 women nationwide become adolescent mothers, making adolescent pregnancy and childbearing issues a frequently encountered occurrence by pediatricians and adolescent medicine health care providers. Both social and medical programs focus on prevention and management of adolescent pregnancies; however, caring for the adolescent-headed family is less well understood. For many teen parents, various environmental and behavioral risks contributed to early childbearing and parenting. Following delivery of the infant, many of these same psycho-social, environmental, and educational factors continue to play a role in the teen's ability to parent effectively. This review explores these factors in relation to teen parenting as well as describes the limited data available on outcomes of adolescent mothers and their infants. Despite negative social stereotypes regarding adolescent fathers, research suggesting that most fathers desire involvement with their infants and the impact of and factors influencing father involvement is explored. Understanding the dynamics of the coparenting relationship, an expanding field of study, will aid practitioners in strengthening and supporting teen parenting by both mothers and fathers. As most teen parents continue to reside with their families, teen parenting has an important impact on the multi-generational family structure. These relationships can serve both to support and at times to hinder the adolescent parents' development as an individual and as a parent. Successful interventions and programs to support the adolescent-headed family take on various forms but are usually comprehensive and multidisciplinary and consider the developmental status of both the parent and the child. To best care for adolescent-headed families, pediatricians and adolescent medicine providers should understand the psychosocial, developmental, educational, and relationship issues that influence adolescent parenting.

Regular Generalized Star Star closed sets in Bitopological Spaces

OpenAIRE

K. Kannan; D. Narasimhan; K. Chandrasekhara Rao; R. Ravikumar

2011-01-01

The aim of this paper is to introduce the concepts of τ1τ2-regular generalized star star closed sets , τ1τ2-regular generalized star star open sets and study their basic properties in bitopological spaces.

Parenting styles, feeding styles and food-related parenting practices in relation to toddlers' eating styles: A cluster-analytic approach.

Science.gov (United States)

van der Horst, Klazine; Sleddens, Ester F C

2017-01-01

Toddlers' eating behaviors are influenced by the way parents interact with their children. The objective of this study was to explore how five major constructs of general parenting behavior cluster in parents of toddlers. These parenting clusters were further explored to see how they differed in the use of feeding strategies (i.e. feeding styles and food parenting practices) and by reported child eating styles. An online survey with 1005 mothers/caregivers (legal guardians) with at least one child between 12 and 36 months old was conducted in the United States in 2012, assessing general parenting behavior, feeding style, food parenting practices and the child eating styles. A three cluster solution of parenting style was found and clusters were labelled as overprotective/supervising, authoritarian, and authoritative. The clusters differed in terms of general parenting behaviors. Both overprotective and authoritative clusters showed high scores on structure, behavioral control, and nurturance. The overprotective cluster scored high on overprotection. The 'authoritarian' cluster showed lowest levels of nurturance, structure and behavioral control. Overprotective and authoritative parents showed very similar patterns in the use of food parenting practices, e.g. monitoring food intake, modeling, and promoting healthy food intake and availability at home. Overprotective parents also reported higher use of pressure to eat and involvement. Authoritarian parents reported high use of giving the child control over their food behaviors, emotion regulation, using food as a reward, and controlling food intake for weight control. Children's eating styles did not largely vary by parenting cluster. This study showed that a relatively new parenting style of overprotection is relevant for children's eating behaviors. Overprotective parents reported food parenting practices that are known to be beneficial for children's food intake, such as modelling healthy food intake, as well as

Parenting styles, feeding styles and food-related parenting practices in relation to toddlers' eating styles: A cluster-analytic approach.

Directory of Open Access Journals (Sweden)

Klazine van der Horst

Full Text Available Toddlers' eating behaviors are influenced by the way parents interact with their children. The objective of this study was to explore how five major constructs of general parenting behavior cluster in parents of toddlers. These parenting clusters were further explored to see how they differed in the use of feeding strategies (i.e. feeding styles and food parenting practices and by reported child eating styles.An online survey with 1005 mothers/caregivers (legal guardians with at least one child between 12 and 36 months old was conducted in the United States in 2012, assessing general parenting behavior, feeding style, food parenting practices and the child eating styles.A three cluster solution of parenting style was found and clusters were labelled as overprotective/supervising, authoritarian, and authoritative. The clusters differed in terms of general parenting behaviors. Both overprotective and authoritative clusters showed high scores on structure, behavioral control, and nurturance. The overprotective cluster scored high on overprotection. The 'authoritarian' cluster showed lowest levels of nurturance, structure and behavioral control. Overprotective and authoritative parents showed very similar patterns in the use of food parenting practices, e.g. monitoring food intake, modeling, and promoting healthy food intake and availability at home. Overprotective parents also reported higher use of pressure to eat and involvement. Authoritarian parents reported high use of giving the child control over their food behaviors, emotion regulation, using food as a reward, and controlling food intake for weight control. Children's eating styles did not largely vary by parenting cluster.This study showed that a relatively new parenting style of overprotection is relevant for children's eating behaviors. Overprotective parents reported food parenting practices that are known to be beneficial for children's food intake, such as modelling healthy food

Maternal role satisfaction: a new approach to assessing parenting.

Science.gov (United States)

Ohashi, J P

1992-01-01

There is a need to study the maternal role beyond the child's first year of life. This investigation, using a framework of Locke's expectancy theory, describes the expectations, surprises, values, and satisfactions experienced by 102 mothers of teens. Content analysis of written narratives describing surprises encountered by these mothers is also presented. Data were collected by questionnaire. Findings offer support for Locke's theory in two ways: (1) expectation for role was less important than value attainment in predicting the level of maternal role satisfaction, and (2) encountering at least one positive surprise was associated with a higher level of maternal role satisfaction. These variables are offered as a useful nursing approach to the assessment of the parenting experience. Knowledge of the satisfactions reported may be encouraging to mothers anticipating this stage of life.

The meaning of early intervention: A parent's experience and reflection on interactions with professionals using a phenomenological ethnographic approach.

Science.gov (United States)

Lee, Yoon H

2015-01-01

The purpose of this study is to describe how a parent's partnership with professionals progresses and evolves throughout the service provisioning process. Using a phenomenological ethnographic approach, the lived reality of a family is depicted as the parent walks through different stages of the Individualized Family Service Plan process over a 6-month period. Data concerning parent-professional interactions were obtained via observation notes and document reviews whereas data regarding parent perceptions were collected through multiple individual interviews. Overall, the parent conveyed her satisfaction with actual services especially regarding the professionals' knowledge and parental advocacy. However, the parent also indicated frustration with the early intervention planning process and "obligated" partnerships with providers. In particular, the providers' lack of sensitivity was noted, and greater emotional and psychological support was suggested. The overall process of developing partnerships with professionals can be excessively intrusive to the family's lives. Future research directions are offered as a contribution for the development of improved policies for early intervention programs regarding family-centered practice, utilizing the perspectives of families.

A new model of spiral galaxies based on propagating star formation

Science.gov (United States)

Sleath, John

1996-01-01

Many models exist in the literature of either star formation or galactic structure, but the former concentrate on small-scale details, whilst the latter, if they include star formation at all, adopt a very simple approach, for example by assuming a power law relationship between the rate of star formation and the gas density (a Schmidt Law). The new model described in this dissertation bridges the gap between these two extremes by adopting a simple, but not simplistic, approach to the detailed physics, allowing the effects of star formation on the broader scale to be investigated. 'Propagating star formation' considers the collapse of molecular clouds (and subsequent creation of new stars) to be triggered by the passage of a shock wave resulting from the supernovae explosions of members of the previous generation of stars. The approach taken is a stochastic one, i.e. we determine from the mass of a cloud the probability of star formation occurring, given that it has been shocked. Models using a similar approach have been described before, but the new model is unique in that it uses a particulate representation of the gas clouds and stellar associations. This permits us to simulate collisions between the particles as they orbit in a realistic galactic gravitational potential and more importantly, to impose a spiral density wave perturbation in a natural way. Such waves arise naturally in N-body simulations where the collective forces between particles are considered explicitly, but we are more interested in its effect on the star formation rate, and hence to make the code more manageable, impose the perturbation by hand. The model has been extremely successful; for example, predicting accurately, with no free parameters, the cluster formation rate for the Milky Way. A Schmidt Law arises as a natural consequence and with a power law index which is consistent with observational constraints. A wide range of galactic morphologies can be produced, including long

The Globular Cluster NGC 6402 (M14). II. Variable Stars

DEFF Research Database (Denmark)

Contreras Peña, C.; Catelan, M.; Grundahl, F.

2018-01-01

approaches for the calibration of the absolute magnitudes of RR Lyrae stars. The possible presence of second-overtone RR Lyrae in M14 is critically addressed, with our results arguing against this possibility. By considering all of the RR Lyrae stars as members of the cluster, we derive =0.589 {{d...

SOVCAN STAR: An international satellite system

Science.gov (United States)

Skatchkov, Valery A.

SOVCAN STAR is a Russian-Canadian cooperative venture company formed to manufacture, test, launch and operate a Ku-band satellite system. Drawing on the more than twenty years communications satellite experience of the founding companies, the SOVCAN STAR satellites are being designed to be competitive and cost effective. They will be equipped with 24 transponders and four steerable antennas. The design allows the operators to switch individual transponders between the various antenna coverage beams. These satellites will offer a high degree of operational flexibility and performance. The SOVCAN STAR strategy is to develop a network of satellites in parallel with the growth and evolution of the traffic requirements. Such an approach minimizes the technical, schedule and program risks while at the same time significantly reduces the financial exposure. The first SOVCAN STAR satellite will be commissioned in 1996 and operated at 14 deg W. The beams will be aligned to North America and Europe offering International service between Canada, the Eastern U.S.A., Europe, Russia and the Western C.I.S. Republics. The second SOVCAN STAR satellite will be commissioned a year later and operated at 145 deg E. This satellite will cover the Western Pacific Ocean, Eastern Asia and Australasia.

Parenting styles, feeding styles and food-related parenting practices in relation to toddlers’ eating styles: A cluster-analytic approach

Science.gov (United States)

Sleddens, Ester F. C.

2017-01-01

Introduction Toddlers’ eating behaviors are influenced by the way parents interact with their children. The objective of this study was to explore how five major constructs of general parenting behavior cluster in parents of toddlers. These parenting clusters were further explored to see how they differed in the use of feeding strategies (i.e. feeding styles and food parenting practices) and by reported child eating styles. Methods An online survey with 1005 mothers/caregivers (legal guardians) with at least one child between 12 and 36 months old was conducted in the United States in 2012, assessing general parenting behavior, feeding style, food parenting practices and the child eating styles. Results A three cluster solution of parenting style was found and clusters were labelled as overprotective/supervising, authoritarian, and authoritative. The clusters differed in terms of general parenting behaviors. Both overprotective and authoritative clusters showed high scores on structure, behavioral control, and nurturance. The overprotective cluster scored high on overprotection. The ‘authoritarian’ cluster showed lowest levels of nurturance, structure and behavioral control. Overprotective and authoritative parents showed very similar patterns in the use of food parenting practices, e.g. monitoring food intake, modeling, and promoting healthy food intake and availability at home. Overprotective parents also reported higher use of pressure to eat and involvement. Authoritarian parents reported high use of giving the child control over their food behaviors, emotion regulation, using food as a reward, and controlling food intake for weight control. Children’s eating styles did not largely vary by parenting cluster. Conclusion This study showed that a relatively new parenting style of overprotection is relevant for children’s eating behaviors. Overprotective parents reported food parenting practices that are known to be beneficial for children’s food intake

LARGER PLANET RADII INFERRED FROM STELLAR ''FLICKER'' BRIGHTNESS VARIATIONS OF BRIGHT PLANET-HOST STARS

International Nuclear Information System (INIS)

Bastien, Fabienne A.; Stassun, Keivan G.; Pepper, Joshua

2014-01-01

Most extrasolar planets have been detected by their influence on their parent star, typically either gravitationally (the Doppler method) or by the small dip in brightness as the planet blocks a portion of the star (the transit method). Therefore, the accuracy with which we know the masses and radii of extrasolar planets depends directly on how well we know those of the stars, the latter usually determined from the measured stellar surface gravity, log g. Recent work has demonstrated that the short-timescale brightness variations ( f licker ) of stars can be used to measure log g to a high accuracy of ∼0.1-0.2 dex. Here, we use flicker measurements of 289 bright (Kepmag < 13) candidate planet-hosting stars with T eff = 4500-6650 K to re-assess the stellar parameters and determine the resulting impact on derived planet properties. This re-assessment reveals that for the brightest planet-host stars, Malmquist bias contaminates the stellar sample with evolved stars: nearly 50% of the bright planet-host stars are subgiants. As a result, the stellar radii, and hence the radii of the planets orbiting these stars, are on average 20%-30% larger than previous measurements had suggested

A model for the infrared emission from an OB star cluster environment

International Nuclear Information System (INIS)

Leisawitz, D.

1990-01-01

Researchers developed an interactive radiative transfer code that predicts the infrared emission from an HII region containing diffuse ionized and atomic gas and dense molecular clouds. This model complements the investigation of the redistribution of OB star luminosity in the interstellar medium (Leisawitz and Hauser 1988, Ap. J., 332, 954). The model can be used as a diagnostic tool to probe the radiation field and matter density in an HII region, place constraints on the proximity and orientation of an illuminated molecular cloud with respect to the ionizing stars, test for the presence of small, transiently heated dust grains, and determine whether the dust-to-gas ratio is normal. Predictions of the model agree qualitatively and quantitatively with observations of blister-type HII regions ionized by well-studied OB clusters in which the distribution of dense neutral material is known. This is illustrated by a model for Infrared Astronomy Satellite (IRAS) observations of the region around NGC 7380 (S142). Researchers plan to use the model in a survey of regions of massive star formation in the outer Galaxy to study OB stars embedded to various degrees in their parental molecular clouds

The Influence of Parents and Teachers on the Deep Learning Approach of Pupils in Norwegian Upper-Secondary Schools

Science.gov (United States)

Elstad, Eyvind; Christophersen, Knut-Andreas; Turmo, Are

2012-01-01

Introduction: The purpose of this article was to explore the influence of parents and teachers on the deep learning approach of pupils by estimating the strength of the relationships between these factors and the motivation, volition and deep learning approach of Norwegian 16-year-olds. Method: Structural equation modeling for cross-sectional…

Parenting and psychiatric rehabilitation : Can parents with severe mental illness benefit from a new approach?

NARCIS (Netherlands)

J.T. van Busschbach; Dr. Lies Korevaar; J. van Weeghel; Dr. Peter van der Ende; Joanne Nicholson

2014-01-01

Abstract: Objective: The aim of this pilot implementation study was to explore the initial experiences with and impact of Parenting with Success and Satisfaction (PARSS), a psychiatric rehabilitation and recoverybased, guided self-help intervention, for parents with severe mental illnesses. Methods:

Parenting and psychiatric rehabilitation: Can parents with severe mental illness benefit from a new approach?

NARCIS (Netherlands)

Jaap van Weeghel; Dr. Peter C. van der Ende; Dr. Lies Korevaar; Jooske T. van Busschbach; Joanne Nicholson

2014-01-01

Abstract: Objective: The aim of this pilot implementation study was to explore the initial experiences with and impact of Parenting with Success and Satisfaction (PARSS), a psychiatric rehabilitation and recovery-based, guided self-help intervention, for parents with severe mental illnesses.

Parent Education Programs as a Psychiatric Approach to Children with Conduct Disorder: An Evaluation through Two Samples

Directory of Open Access Journals (Sweden)

Burcu Arkan

2009-08-01

Full Text Available Conduct disorder is a category to describe the behaviors which have an adverse affect on the individual, family or society, violate the basic rights of other people and ignore the age-appropriate social norms and rules. Parental behaviors should be shaped as well as those of the children in order for conduct disorder to be treated. The reason for this is that parental attitudes play a key role in emergence of anti-social behaviors among children. Therefore, parent programs have been undertaken for the last thirty years. It has been proved that parent programs are effective in children with conduct disorder who display highly disruptive behaviors. The two best parent programs implemented on the parents of children diagnosed with conduct disorder are Triple P and Incredible Years which cooperate with families and the society, reduce the risk factors, support the protective factors, have a multi-disciplinary approach (psychiatrist, psychologist, nurse, child development and educationalist, social service specialist, psychological consultant, teacher, etc., having high evidence standards, use randomized controlled studies and yield long-term results. For that reason, this literature review was conducted in order to evaluate the efficacy of these two programs, to determine the differences, what is known about the issue.

Leaders' limitations and approaches to creating conditions for interaction and communication in parental groups: A qualitative study.

Science.gov (United States)

Frykedal, Karin Forslund; Rosander, Michael; Barimani, Mia; Berlin, Anita

2018-01-01

The aim of this study was to describe and understand parental group (PG) leaders' experiences of creating conditions for interaction and communication. The data consisted of 10 interviews with 14 leaders. The transcribed interviews were analysed using thematic analysis. The results showed that the leaders' ambition was to create a parent-centred learning environment by establishing conditions for interaction and communication between the parents in the PGs. However, the leaders' experience was that their professional competencies were insufficient and that they lacked pedagogical tools to create constructive group discussions. Nevertheless, they found other ways to facilitate interactive processes. Based on their experience in the PG, the leaders constructed informal socio-emotional roles for themselves (e.g. caring role and personal role) and let their more formal task roles (e.g. professional role, group leader and consulting role) recede into the background, so as to remove the imbalance of power between the leaders and the parents. They believed this would make the parents feel more confident and make it easier for them to start communicating and interacting. This personal approach places them in a vulnerable position in the PG, in which it is easy for them to feel offended by parents' criticism, questioning or silence.

Search for OB stars running away from young star clusters. II. The NGC 6357 star-forming region

Science.gov (United States)

Gvaramadze, V. V.; Kniazev, A. Y.; Kroupa, P.; Oh, S.

2011-11-01

Dynamical few-body encounters in the dense cores of young massive star clusters are responsible for the loss of a significant fraction of their massive stellar content. Some of the escaping (runaway) stars move through the ambient medium supersonically and can be revealed via detection of their bow shocks (visible in the infrared, optical or radio). In this paper, which is the second of a series of papers devoted to the search for OB stars running away from young ( ≲ several Myr) Galactic clusters and OB associations, we present the results of the search for bow shocks around the star-forming region NGC 6357. Using the archival data of the Midcourse Space Experiment (MSX) satellite and the Spitzer Space Telescope, and the preliminary data release of the Wide-Field Infrared Survey Explorer (WISE), we discovered seven bow shocks, whose geometry is consistent with the possibility that they are generated by stars expelled from the young (~1-2 Myr) star clusters, Pismis 24 and AH03 J1725-34.4, associated with NGC 6357. Two of the seven bow shocks are driven by the already known OB stars, HD 319881 and [N78] 34. Follow-up spectroscopy of three other bow-shock-producing stars showed that they are massive (O-type) stars as well, while the 2MASS photometry of the remaining two stars suggests that they could be B0 V stars, provided that both are located at the same distance as NGC 6357. Detection of numerous massive stars ejected from the very young clusters is consistent with the theoretical expectation that star clusters can effectively lose massive stars at the very beginning of their dynamical evolution (long before the second mechanism for production of runaway stars, based on a supernova explosion in a massive tight binary system, begins to operate) and lends strong support to the idea that probably all field OB stars have been dynamically ejected from their birth clusters. A by-product of our search for bow shocks around NGC 6357 is the detection of three circular

Unsupervised classification of variable stars

Science.gov (United States)

Valenzuela, Lucas; Pichara, Karim

2018-03-01

During the past 10 years, a considerable amount of effort has been made to develop algorithms for automatic classification of variable stars. That has been primarily achieved by applying machine learning methods to photometric data sets where objects are represented as light curves. Classifiers require training sets to learn the underlying patterns that allow the separation among classes. Unfortunately, building training sets is an expensive process that demands a lot of human efforts. Every time data come from new surveys; the only available training instances are the ones that have a cross-match with previously labelled objects, consequently generating insufficient training sets compared with the large amounts of unlabelled sources. In this work, we present an algorithm that performs unsupervised classification of variable stars, relying only on the similarity among light curves. We tackle the unsupervised classification problem by proposing an untraditional approach. Instead of trying to match classes of stars with clusters found by a clustering algorithm, we propose a query-based method where astronomers can find groups of variable stars ranked by similarity. We also develop a fast similarity function specific for light curves, based on a novel data structure that allows scaling the search over the entire data set of unlabelled objects. Experiments show that our unsupervised model achieves high accuracy in the classification of different types of variable stars and that the proposed algorithm scales up to massive amounts of light curves.

Do All O Stars Form in Star Clusters?

Science.gov (United States)

Weidner, C.; Gvaramadze, V. V.; Kroupa, P.; Pflamm-Altenburg, J.

The question whether or not massive stars can form in isolation or only in star clusters is of great importance for the theory of (massive) star formation as well as for the stellar initial mass function of whole galaxies (IGIMF-theory). While a seemingly easy question it is rather difficult to answer. Several physical processes (e.g. star-loss due to stellar dynamics or gas expulsion) and observational limitations (e.g. dust obscuration of young clusters, resolution) pose severe challenges to answer this question. In this contribution we will present the current arguments in favour and against the idea that all O stars form in clusters.

Parent-child aggression: association with child abuse potential and parenting styles.

Science.gov (United States)

Rodriguez, Christina M

2010-01-01

The present investigation predicted that greater use of corporal punishment as well as physical maltreatment would be associated with child abuse potential and selected parenting styles. Three independent studies were examined, two with community samples and a third with a clinical at-risk sample of parents. Parents across all studies anonymously completed the Child Abuse Potential Inventory, the Parent-Child Conflict Tactics Scale to assess physical discipline and maltreatment, as well as the Parenting Scale to measure dysfunctional parenting styles. Findings support that overall parent-child aggression, as well as physical maltreatment behaviors specifically, were associated with child abuse potential. Parent-child aggression was also related to dysfunctional parenting styles, particularly an overreactive, authoritarian parenting style. Permissive parenting was also identified as potentially associated with physical maltreatment, although the findings regarding such lax parenting styles are less clear. Intriguing findings emerged regarding the connection of psychological aggression to both child abuse potential and dysfunctional parenting style. Child abuse potential was also associated with dysfunctional parenting style, particularly harsh, overreactive approaches. Recommendations for future study with at-risk samples and additional research on permissive parenting and psychological aggression are discussed.

Relating follicly-challenged compact stars to bald black holes: A link between two no-hair properties

Science.gov (United States)

Yagi, Kent; Yunes, Nicolás

2015-05-01

Compact stars satisfy certain no-hair relations through which their multipole moments are given by their mass, spin and quadrupole moment. These relations are approximately independent of their equation of state, relating pressure to density. Such relations are similar to the black hole no-hair theorems, but these possess event horizons inside which information that led to their formation can hide. Compact stars do not possess horizons, so whether their no-hair relations are related to the black hole ones is unclear. We investigate how the two relations are related by studying relations among multipole moments for compact stars with anisotropic pressure as a toy model, which allows such stars to be more compact than those with isotropic pressure. We here show numerically that the compact star no-hair relations approach the black hole ones as the compactness approaches that of a black hole. We also prove analytically that the current dipole moment exactly reaches the black hole limit quadratically in compactness as strongly anisotropic stars approach the black hole limit. We moreover show that compact stars become progressively oblate in this limit, even if prolate at low compactness due to strong anisotropies.

Parenting and Psychiatric Rehabilitation : Can Parents With Severe Mental Illness Benefit From a New Approach?

NARCIS (Netherlands)

van der Ende, Peter C.; van Busschbach, Jooske T.; Nicholson, Joanne; Korevaar, Eliza L.; van Weeghel, Jaap

Objective: The aim of this pilot implementation study was to explore the initial experiences with and impact of Parenting with Success and Satisfaction (PARSS), a psychiatric rehabilitation and recovery-based, guided self-help intervention, for parents with severe mental illnesses. Methods: Changes

Giant CP stars

International Nuclear Information System (INIS)

Loden, L.O.; Sundman, A.

1989-01-01

This study is part of an investigation of the possibility of using chemically peculiar (CP) stars to map local galactic structure. Correct luminosities of these stars are therefore crucial. CP stars are generally regarded as main-sequence or near-main-sequence objects. However, some CP stars have been classified as giants. A selection of stars, classified in literature as CP giants, are compared to normal stars in the same effective temperature interval and to ordinary 'non giant' CP stars. There is no clear confirmation of a higher luminosity for 'CP giants', than for CP stars in general. In addition, CP characteristics seem to be individual properties not repeated in a component star or other cluster members. (author). 50 refs., 5 tabs., 3 figs

Bursting star formation and the overabundance of Wolf-Rayet stars

International Nuclear Information System (INIS)

Bodigfee, G.; Deloore, C.

1985-01-01

The ratio of the number of WR-stars to their OB progenitors appears to be significantly higher in some extragalactic systems than in our Galaxy. This overabundance of Wolf-Rayet-stars can be explained as a consequence of a recent burst of star formation. It is suggested that this burst is the manifestation of a long period nonlinear oscillation in the star formation process, produced by positive feedback effects between young stars and the interstellar medium. Star burst galaxies with large numbers of WR-stars must generate gamma fluxes but due to the distance, all of them are beyond the reach of present-day detectors, except probably 30 Dor

Bulk yields of nucleosynthesis from massive stars

International Nuclear Information System (INIS)

Arnett, W.D.

1978-01-01

Preliminary estimates are made of the absolute yields of abundant nuclei synthesized in observed stars. The compositions of nine helium stars of mass 3 or =10M/sub sun/ is estimated. A variety of choices for the initial mass function (IMF) are used to calculate the yield per stellar generation. For standard choices of the (IMF) the absolute and relative yields of 12 C, 16 O, 20 Ne, 24 Mg, the Si to Ca group, and the iron group agree with solar system values, to the accuracy of the calculations. The relative yields are surprisingly insensitive to the slope of the IMF. In a second approach, using standard estimates (Ostriker, Richstone, and Thuan) for the current rate of stellar death, I find the present rate of nucleosynthesis in the solar neighborhood to be about 10%of the average rate over galactic history. This result is consistent with many standard models of galactic evolution (for example, the Schmidt model in which star formation goes as gas density squared). It appears that if the star formation rate is high enough to produce the stars we see around us, then the nucleosynthesis rate is large enough to produce the processed nuclei (except 4 He) seen in those stars. The typical nucleosynthesis source is massive (Mapprox. =30 M/sub sun/); the death rate of such stars is a small fraction (3-10%) of recent estimates of the total rate of supernovae

Authoritative Parenting, Parenting Stress, and Self-Care in Pre-Adolescents with Type 1 Diabetes

OpenAIRE

Monaghan, Maureen; Horn, Ivor B.; Alvarez, Vanessa; Cogen, Fran R.; Streisand, Randi

2012-01-01

Parent involvement in type 1 diabetes (T1DM) care leads to improved adherence; however, the manner in which parents approach illness management interactions with children must also be considered. It was hypothesized that greater use of an authoritative parenting style and less parenting stress would be associated with greater behavioral adherence and better metabolic control. Ninety-five primary caregivers of preadolescents (ages 8-11) with T1DM completed questionnaires assessing parenting st...

TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

Energy Technology Data Exchange (ETDEWEB)

Liu Tie; Wu Yuefang; Zhang Huawei [Department of Astronomy, Peking University, 100871 Beijing (China); Qin Shengli, E-mail: liutiepku@gmail.com [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

2012-05-20

The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10{sup 3} cm{sup -3} and kinematic temperature {approx}20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

International Nuclear Information System (INIS)

Liu Tie; Wu Yuefang; Zhang Huawei; Qin Shengli

2012-01-01

The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10 3 cm –3 and kinematic temperature ∼20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

Information theoretical methods as discerning quantifiers of the equations of state of neutron stars

Energy Technology Data Exchange (ETDEWEB)

Avellar, M.G.B. de, E-mail: mgb.avellar@iag.usp.br [Instituto de Astronomia, Geofísica e Ciências Atmosféricas – Universidade de São Paulo, Rua do Matão 1226, Cidade Universitária, 05508-090, São Paulo, SP (Brazil); Souza, R.A. de, E-mail: rodrigo.souza@usp.br [Instituto de Astronomia, Geofísica e Ciências Atmosféricas – Universidade de São Paulo, Rua do Matão 1226, Cidade Universitária, 05508-090, São Paulo, SP (Brazil); Horvath, J.E., E-mail: foton@iag.usp.br [Instituto de Astronomia, Geofísica e Ciências Atmosféricas – Universidade de São Paulo, Rua do Matão 1226, Cidade Universitária, 05508-090, São Paulo, SP (Brazil); Paret, D.M., E-mail: dmanreza@fisica.uh.cu [Facultad de Física, Universidad de la Habana, San Lázaro y L, Vedado La Habana, 10400 (Cuba)

2014-11-07

In this work we use the statistical measures of information entropy, disequilibrium and complexity to discriminate different approaches and parametrizations for different equations of state for quark stars. We confirm the usefulness of such quantities to quantify the role of interactions in such stars. We find that within this approach, a quark matter equation of state such as SU(2) NJL with vectorial coupling and phase transition is slightly favoured and deserves deeper studies. - Highlights: • We used information theory tools to discern different compositions for compact stars. • Hadronic and quark stars analogues behave differently when analyzed with these tools. • The effects of different equations of state are singled out in this work.

Parental Involvement in Elementary Children's Religious Education: A Phenomenological Approach

Science.gov (United States)

Bunnell, Peter Wayne

2016-01-01

The issue of parental involvement in religious education is an important one for the family, the church, the Christian school, and society. The purpose of this phenomenological study was to describe parents' concepts and practices of involvement in their children's religious education as evangelical Christian parents in Midwestern communities.…

A Strength-Based Approach to Parent Education for Children with Autism

Science.gov (United States)

Steiner, Amanda Mossman

2011-01-01

Despite the ubiquitous nature of parent education in autism treatment, relatively few studies directly address "how" parent education should be conducted. Given that the literature on parental well-being suggests that treatments that facilitate positive parental adaptation to their child's disability may be beneficial, this study…

Star Polymers.

Science.gov (United States)

Ren, Jing M; McKenzie, Thomas G; Fu, Qiang; Wong, Edgar H H; Xu, Jiangtao; An, Zesheng; Shanmugam, Sivaprakash; Davis, Thomas P; Boyer, Cyrille; Qiao, Greg G

2016-06-22

Recent advances in controlled/living polymerization techniques and highly efficient coupling chemistries have enabled the facile synthesis of complex polymer architectures with controlled dimensions and functionality. As an example, star polymers consist of many linear polymers fused at a central point with a large number of chain end functionalities. Owing to this exclusive structure, star polymers exhibit some remarkable characteristics and properties unattainable by simple linear polymers. Hence, they constitute a unique class of technologically important nanomaterials that have been utilized or are currently under audition for many applications in life sciences and nanotechnologies. This article first provides a comprehensive summary of synthetic strategies towards star polymers, then reviews the latest developments in the synthesis and characterization methods of star macromolecules, and lastly outlines emerging applications and current commercial use of star-shaped polymers. The aim of this work is to promote star polymer research, generate new avenues of scientific investigation, and provide contemporary perspectives on chemical innovation that may expedite the commercialization of new star nanomaterials. We envision in the not-too-distant future star polymers will play an increasingly important role in materials science and nanotechnology in both academic and industrial settings.

BOOK REVIEW: The Gravitational Million-Body Problem: A Multidisciplinary Approach to Star Cluster Dynamics

Science.gov (United States)

Heggie, D.; Hut, P.

2003-10-01

focus on N = 106 for two main reasons: first, direct numerical integrations of N-body systems are beginning to approach this threshold, and second, globular star clusters provide remarkably accurate physical instantiations of the idealized N-body problem with N = 105 - 106. The authors are distinguished contributors to the study of star-cluster dynamics and the gravitational N-body problem. The book contains lucid and concise descriptions of most of the important tools in the subject, with only a modest bias towards the authors' own interests. These tools include the two-body relaxation approximation, the Vlasov and Fokker-Planck equations, regularization of close encounters, conducting fluid models, Hill's approximation, Heggie's law for binary star evolution, symplectic integration algorithms, Liapunov exponents, and so on. The book also provides an up-to-date description of the principal processes that drive the evolution of idealized N-body systems - two-body relaxation, mass segregation, escape, core collapse and core bounce, binary star hardening, gravothermal oscillations - as well as additional processes such as stellar collisions and tidal shocks that affect real star clusters but not idealized N-body systems. In a relatively short (300 pages plus appendices) book such as this, many topics have to be omitted. The reader who is hoping to learn about the phenomenology of star clusters will be disappointed, as the description of their properties is limited to only a page of text; there is also almost no discussion of other, equally interesting N-body systems such as galaxies(N approx 106 - 1012), open clusters (N simeq 102 - 104), planetary systems, or the star clusters surrounding black holes that are found in the centres of most galaxies. All of these omissions are defensible decisions. Less defensible is the uneven set of references in the text; for example, nowhere is the reader informed that the classic predecessor to this work was Spitzer's 1987 monograph

Parent Involvement and the Impact on Student Achievement in Grades 2-5

Science.gov (United States)

Thurber, Yvonne Marie

2013-01-01

This quantitative research study examined the relationship between student achievement in reading and mathematics on the STAR (Standardized Test for the Assessment of Reading and Mathematics) and parent involvement in specific character development activities. The research design was quantitative in nature and conducted in two similar elementary…

Wolf-Rayet stars

Energy Technology Data Exchange (ETDEWEB)

Sahade, J

1981-12-01

Aspects of the problems of the Wolf-Rayet stars related to their chemical composition, their evolutionary status, and their apparent dichotomy in two spectral sequences are discussed. Dogmas concerning WR stars are critically discussed, including the belief that WR stars lack hydrogen, that they are helium stars evolved from massive close binaries, and the existence of a second WR stage in which the star is a short-period single-lined binary. The relationship of WR stars with planetary nebulae is addressed, as is the membership of these stars in clusters and associations. The division of WR stars into WN and WC sequences is considered, questioning the reasonability of accounting for WR line formation in terms of abundance differences.

StarDOM: From STAR format to XML

International Nuclear Information System (INIS)

Linge, Jens P.; Nilges, Michael; Ehrlich, Lutz

1999-01-01

StarDOM is a software package for the representation of STAR files as document object models and the conversion of STAR files into XML. This allows interactive navigation by using the Document Object Model representation of the data as well as easy access by XML query languages. As an example application, the entire BioMagResBank has been transformed into XML format. Using an XML query language, statistical queries on the collected NMR data sets can be constructed with very little effort. The BioMagResBank/XML data and the software can be obtained at http://www.nmr.embl-heidelberg.de/nmr/StarDOM/

The meaning of early intervention: A parent's experience and reflection on interactions with professionals using a phenomenological ethnographic approach

Directory of Open Access Journals (Sweden)

Yoon H. Lee

2015-07-01

Full Text Available The purpose of this study is to describe how a parent's partnership with professionals progresses and evolves throughout the service provisioning process. Using a phenomenological ethnographic approach, the lived reality of a family is depicted as the parent walks through different stages of the Individualized Family Service Plan process over a 6-month period. Data concerning parent–professional interactions were obtained via observation notes and document reviews whereas data regarding parent perceptions were collected through multiple individual interviews. Overall, the parent conveyed her satisfaction with actual services especially regarding the professionals’ knowledge and parental advocacy. However, the parent also indicated frustration with the early intervention planning process and “obligated” partnerships with providers. In particular, the providers’ lack of sensitivity was noted, and greater emotional and psychological support was suggested. The overall process of developing partnerships with professionals can be excessively intrusive to the family's lives. Future research directions are offered as a contribution for the development of improved policies for early intervention programs regarding family-centered practice, utilizing the perspectives of families.

Spheroidal Populated Star Systems

Science.gov (United States)

Angeletti, Lucio; Giannone, Pietro

2008-10-01

Globular clusters and low-ellipticity early-type galaxies can be treated as systems populated by a large number of stars and whose structures can be schematized as spherically symmetric. Their studies profit from the synthesis of stellar populations. The computation of synthetic models makes use of various contributions from star evolution and stellar dynamics. In the first sections of the paper we present a short review of our results on the occurrence of galactic winds in star systems ranging from globular clusters to elliptical galaxies, and the dynamical evolution of a typical massive globular cluster. In the subsequent sections we describe our approach to the problem of the stellar populations in elliptical galaxies. The projected radial behaviours of spectro-photometric indices for a sample of eleven galaxies are compared with preliminary model results. The best agreement between observation and theory shows that our galaxies share a certain degree of heterogeneity. The gas energy dissipation varies from moderate to large, the metal yield ranges from solar to significantly oversolar, the dispersion of velocities is isotropic in most of the cases and anisotropic in the remaining instances.

STARS no star on Kauai

International Nuclear Information System (INIS)

Jones, M.

1993-01-01

The island of Kuai, home to the Pacific Missile Range Facility, is preparing for the first of a series of Star Wars rocket launches expected to begin early this year. The Strategic Defense Initiative plans 40 launches of the Stategic Target System (STARS) over a 10-year period. The focus of the tests appears to be weapons and sensors designed to combat multiple-warhead ICBMs, which will be banned under the START II Treaty that was signed in January. The focus of this article is to express the dubious value of testing the STARS at a time when their application will not be an anticipated problem

Star Formation in the Orion Nebula Cluster

Science.gov (United States)

Palla, Francesco; Stahler, Steven W.

1999-11-01

We study the record of star formation activity within the dense cluster associated with the Orion Nebula. The bolometric luminosity function of 900 visible members is well matched by a simplified theoretical model for cluster formation. This model assumes that stars are produced at a constant rate and distributed according to the field-star initial mass function. Our best-fit age for the system, within this framework, is 2×106 yr. To undertake a more detailed analysis, we present a new set of theoretical pre-main-sequence tracks. These cover all masses from 0.1 to 6.0 Msolar, and start from a realistic stellar birthline. The tracks end along a zero-age main-sequence that is in excellent agreement with the empirical one. As a further aid to cluster studies, we offer an heuristic procedure for the correction of pre-main-sequence luminosities and ages to account for the effects of unresolved binary companions. The Orion Nebula stars fall neatly between our birthline and zero-age main-sequence in the H-R diagram. All those more massive than about 8 Msolar lie close to the main sequence, as also predicted by theory. After accounting for the finite sensitivity of the underlying observations, we confirm that the population between 0.4 and 6.0 Msolar roughly follows a standard initial mass function. We see no evidence for a turnover at lower masses. We next use our tracks to compile stellar ages, also between 0.4 and 6.0 Msolar. Our age histogram reveals that star formation began at a low level some 107 yr ago and has gradually accelerated to the present epoch. The period of most active formation is indeed confined to a few×106 yr, and has recently ended with gas dispersal from the Trapezium. We argue that the acceleration in stellar births, which extends over a wide range in mass, reflects the gravitational contraction of the parent cloud spawning this cluster.

Active Star Architectures For Fiber Optics Ethernet

Science.gov (United States)

Linde, Yoseph L.

1988-12-01

Ethernet, and the closely related IEEE 802.3 CSMA/CD standard (Carrier Sense Multiple Access with Collision Detection), is probably the widest used method for high speed Local Area Networks (LANs). The original Ethernet medium was baseband coax but the wide acceptance of the system necessitated the ability to use Ethernet on a variety of media. So far the use of Ethernet on Thin Coax (CheaperNet), Twisted Pair (StarLan) and Broadband Coax has been standardized. Recently, an increased interest in Fiber Optic based LANs resulted in a formation of an IEEE group whose charter is to recommend approaches for Active and Passive Fiber Optic Ethernet systems. The various approaches which are being considered are described in this paper with an emphasis on Active Star based systems.

Children's night waking among toddlers: relationships with mothers' and fathers' parenting approaches and children's behavioural difficulties.

Science.gov (United States)

Zaidman-Zait, Anat; Hall, Wendy A

2015-07-01

To explore associations between children's sleep problems, and behavioural difficulties and parenting approaches. Children commonly have problematic night waking; however, relationships between parenting cognitions and behaviours and children's sleep problems are rarely examined. Longitudinal children's cohort study from 5-29 months post birth. Data were taken from the Quebec Longitudinal Study of Child Development (1998-2007) at three phases: 5, 17 and 29 months of age. Thousand four hundred and eighty-seven families were included in our study based on: participation from phase 1 (5-months old), both parents' reports on parenting cognitions/behaviours and child behavioural difficulties at 29 months, and mothers' reports of children's sleep at 29 months. In 2013, we conducted repeated measures anovas and manovas including children's gender. Extended night-time waking patterns (wakes of ≥20 minutes) were associated with mothers' and fathers' lower sense of parenting impact and higher overprotectiveness and mothers' lower self-efficacy and higher coerciveness for 29-month-old children. In the extended waking group, mothers consistently reported lower self-efficacy, higher overprotectiveness and lower parenting impact at 5, 17 and 29 months. For those children, fathers were only more overprotective at 5 and 29 months. Regarding 29-month-old children's behaviour, children in the extended night waking group had highest scores on externalizing and internalizing behaviours. Girls had higher scores on shyness/inhibition and boys had higher scores on aggression/hyperactivity. Mothers' and fathers' parenting cognitions and behaviours are affected by 29-month-old children's night waking patterns and night waking patterns are associated with children's behavioural problems. © 2015 John Wiley & Sons Ltd.

Making the Difference with Active Parenting; Forming Educational Partnerships between Parents and Schools

Science.gov (United States)

Oostdam, Ron; Hooge, Edith

2013-01-01

Although parental involvement is often a priority on the quality agenda of schools for primary and secondary education, it is still not usual to involve parents as an educational partner in the actual learning process of their child. Rather than adopting an open approach, teachers tend to tell parents what they should do or keep them at a safe…

Learning the Relationship between Galaxy Spectra and Star Formation Histories

Science.gov (United States)

Lovell, Christopher; Acquaviva, Viviana; Iyer, Kartheik; Gawiser, Eric

2018-01-01

We explore novel approaches to the problem of predicting a galaxy’s star formation history (SFH) from its Spectral Energy Distribution (SED). Traditional approaches to SED template fitting use constant or exponentially declining SFHs, and are known to incur significant bias in the inferred SFHs, which are typically skewed toward younger stellar populations. Machine learning approaches, including tree ensemble methods and convolutional neural networks, would not be affected by the same bias, and may work well in recovering unbiased and multi-episodic star formation histories. We use a supervised approach whereby models are trained using synthetic spectra, generated from three state of the art hydrodynamical simulations, including nebular emission. We explore how SED feature maps can be used to highlight areas of the spectrum with the highest predictive power and discuss the limitations of the approach when applied to real data.

RED CLUMP STARS IN THE SAGITTARIUS TIDAL STREAMS

International Nuclear Information System (INIS)

Carrell, Kenneth; Chen Yuqin; Wilhelm, Ronald

2012-01-01

We have probed a section (l ∼ 150, b ∼ –60) of the trailing tidal arm of the Sagittarius dwarf spheroidal galaxy by identifying a sample of Red Clump (RC) stream stars. RC stars are not generally found in the halo field, but are found in significant numbers in both the Sagittarius galaxy and its tidal streams, making them excellent probes of stream characteristics. Our target sample was selected using photometric data from the Sloan Digital Sky Survey, Data Release 6, which was constrained in color to match the Sagittarius RC stars. Spectroscopic observations of the target stars were conducted at Kitt Peak National Observatory using the WIYN telescope. The resulting spectroscopic sample is magnitude limited and contains both main-sequence disk stars and evolved RC stars. We have developed a method to systematically separate these two stellar classes using kinematic information and a Bayesian approach for surface gravity determination. The resulting RC sample allows us to determine an absolute stellar density of ρ = 2.7 ± 0.5 RC stars kpc –3 at this location in the stream. Future measurements of stellar densities for a variety of populations and at various locations along the streams will lead to a much improved understanding of the original nature of the Sagittarius galaxy and the physical processes controlling its disruption and subsequent stream generation.

The experience of parents implementing authoritarian parenting for their school-age children.

Science.gov (United States)

Benga Olla, Marice; Catharina Daulima, Novy Helena; Eka Putri, Yossie Susanti

2018-02-01

To explore families' experiences who use an authoritarian parenting style in caring for school-age children. This was a qualitative study employing a phenomenological approach. The sampling method was to interview parents of school-age children living in the Central Maluku district in Indonesia. The findings of this study generated the following themes: (1) parents strictly controlled their children to achieve the parental values and expectations, (2) children failed to meet the parental values and expectations, and (3) problems experienced by the children were the results of the parenting style. This study suggested nursing professionals provide adequate information for parents with respect to parenting styles that may facilitate the optimal growth and development of the children. Future studies pertinent to cultural factors associated with authoritarian parenting were also suggested to better understand the cultural context of this parenting style. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

ABIOTIC O{sub 2} LEVELS ON PLANETS AROUND F, G, K, AND M STARS: POSSIBLE FALSE POSITIVES FOR LIFE?

Energy Technology Data Exchange (ETDEWEB)

Harman, C. E.; Kasting, J. F. [Geosciences Department, Pennsylvania State University, University Park, PA 16802 (United States); Schwieterman, E. W. [NASA Astrobiology Institute—Virtual Planetary Laboratory (United States); Schottelkotte, J. C., E-mail: ceharmanjr@psu.edu [Astronomy Department, Pennsylvania State University, University Park, PA 16802 (United States)

2015-10-20

In the search for life on Earth-like planets around other stars, the first (and likely only) information will come from the spectroscopic characterization of the planet's atmosphere. Of the countless number of chemical species terrestrial life produces, only a few have the distinct spectral features and the necessary atmospheric abundance to be detectable. The easiest of these species to observe in Earth's atmosphere is O{sub 2} (and its photochemical byproduct, O{sub 3}). However, O{sub 2} can also be produced abiotically by photolysis of CO{sub 2}, followed by recombination of O atoms with each other. CO is produced in stoichiometric proportions. Whether O{sub 2} and CO can accumulate to appreciable concentrations depends on the ratio of far-ultraviolet (FUV) to near-ultraviolet (NUV) radiation coming from the planet's parent star and on what happens to these gases when they dissolve in a planet's oceans. Using a one-dimensional photochemical model, we demonstrate that O{sub 2} derived from CO{sub 2} photolysis should not accumulate to measurable concentrations on planets around F- and G-type stars. K-star, and especially M-star planets, however, may build up O{sub 2} because of the low NUV flux from their parent stars, in agreement with some previous studies. On such planets, a “false positive” for life is possible if recombination of dissolved CO and O{sub 2} in the oceans is slow and if other O{sub 2} sinks (e.g., reduced volcanic gases or dissolved ferrous iron) are small. O{sub 3}, on the other hand, could be detectable at UV wavelengths (λ < 300 nm) for a much broader range of boundary conditions and stellar types.

Parents-CARE: a suicide prevention program for parents of at-risk youth.

Science.gov (United States)

Hooven, Carole

2013-02-01

Families play an important role in youth suicide prevention, as both a source of protection and a source of risk, and thus are an important target for adolescent suicide prevention programs. This article describes in detail Parents-CARE, a brief youth suicide prevention program for parents, for which effectiveness has been demonstrated. Engaging parents in preventive intervention can be challenging; therefore, the feasibility, acceptability, and relevance of the program to parents are examined. A total of 289 households participated in Parents-CARE. Parent attendance data and parent and interventionist process data are utilized to demonstrate the positive response by parents to the program. The Parents-CARE program was highly attended, and ratings demonstrate that parents were engaged in the program. Ratings show parents found the program both acceptable and relevant. Hence, the program described is promising for clinicians working with at-risk youth as they seek brief, accessible, and effective interventions that include parents in order to amplify the effects of an individual intervention approach. © 2013 Wiley Periodicals, Inc.

From the crust to the core of neutron stars on a microscopic basis

Science.gov (United States)

Baldo, M.; Burgio, G. F.; Centelles, M.; Sharma, B. K.; Viñas, X.

2014-09-01

Within a microscopic approach the structure of Neutron Stars is usually studied by modelling the homogeneous nuclear matter of the core by a suitable Equation of State, based on a many-body theory, and the crust by a functional based on a more phenomenological approach. We present the first calculation of Neutron Star overall structure by adopting for the core an Equation of State derived from the Brueckner-Hartree-Fock theory and for the crust, including the pasta phase, an Energy Density Functional based on the same Equation of State, and which is able to describe accurately the binding energy of nuclei throughout the mass table. Comparison with other approaches is discussed. The relevance of the crust Equation of State for the Neutron Star radius is particularly emphasised.

Strange matter in compact stars

Directory of Open Access Journals (Sweden)

Klähn Thomas

2018-01-01

Full Text Available We discuss possible scenarios for the existence of strange matter in compact stars. The appearance of hyperons leads to a hyperon puzzle in ab-initio approaches based on effective baryon-baryon potentials but is not a severe problem in relativistic mean field models. In general, the puzzle can be resolved in a natural way if hadronic matter gets stiffened at supersaturation densities, an effect based on the quark Pauli quenching between hadrons. We explain the conflict between the necessity to implement dynamical chiral symmetry breaking into a model description and the conditions for the appearance of absolutely stable strange quark matter that require both, approximately masslessness of quarks and a mechanism of confinement. The role of strangeness in compact stars (hadronic or quark matter realizations remains unsettled. It is not excluded that strangeness plays no role in compact stars at all. To answer the question whether the case of absolutely stable strange quark matter can be excluded on theoretical grounds requires an understanding of dense matter that we have not yet reached.

Strange matter in compact stars

Science.gov (United States)

Klähn, Thomas; Blaschke, David B.

2018-02-01

We discuss possible scenarios for the existence of strange matter in compact stars. The appearance of hyperons leads to a hyperon puzzle in ab-initio approaches based on effective baryon-baryon potentials but is not a severe problem in relativistic mean field models. In general, the puzzle can be resolved in a natural way if hadronic matter gets stiffened at supersaturation densities, an effect based on the quark Pauli quenching between hadrons. We explain the conflict between the necessity to implement dynamical chiral symmetry breaking into a model description and the conditions for the appearance of absolutely stable strange quark matter that require both, approximately masslessness of quarks and a mechanism of confinement. The role of strangeness in compact stars (hadronic or quark matter realizations) remains unsettled. It is not excluded that strangeness plays no role in compact stars at all. To answer the question whether the case of absolutely stable strange quark matter can be excluded on theoretical grounds requires an understanding of dense matter that we have not yet reached.

Star-forming galaxy models: Blending star formation into TREESPH

Science.gov (United States)

Mihos, J. Christopher; Hernquist, Lars

1994-01-01

We have incorporated star-formation algorithms into a hybrid N-body/smoothed particle hydrodynamics code (TREESPH) in order to describe the star forming properties of disk galaxies over timescales of a few billion years. The models employ a Schmidt law of index n approximately 1.5 to calculate star-formation rates, and explicitly include the energy and metallicity feedback into the Interstellar Medium (ISM). Modeling the newly formed stellar population is achieved through the use of hybrid SPH/young star particles which gradually convert from gaseous to collisionless particles, avoiding the computational difficulties involved in creating new particles. The models are shown to reproduce well the star-forming properties of disk galaxies, such as the morphology, rate of star formation, and evolution of the global star-formation rate and disk gas content. As an example of the technique, we model an encounter between a disk galaxy and a small companion which gives rise to a ring galaxy reminiscent of the Cartwheel (AM 0035-35). The primary galaxy in this encounter experiences two phases of star forming activity: an initial period during the expansion of the ring, and a delayed phase as shocked material in the ring falls back into the central regions.

Nuclear structure for the crust of neutron stars and exotic nuclei

International Nuclear Information System (INIS)

Goegelein, Peter

2007-01-01

In this work the Skyrme Hartree-Fock and Relativistic Hartree--Fock approaches have been considered to describe the structure of nuclear systems ranging from finite nuclei, structures in the crust of neutron stars to homogeneous matter. Effects of pairing correlations and finite temperature are also taken into account. The numerical procedure in the cubic box is described for the Skyrme Hartree-Fock as well as the relativistic Hartree-Fock approach. And finally, results for the crust of neutron stars and exotic nuclei are presented and discussed. (orig.)

Nuclear structure for the crust of neutron stars and exotic nuclei

Energy Technology Data Exchange (ETDEWEB)

Goegelein, Peter

2007-07-01

In this work the Skyrme Hartree-Fock and Relativistic Hartree--Fock approaches have been considered to describe the structure of nuclear systems ranging from finite nuclei, structures in the crust of neutron stars to homogeneous matter. Effects of pairing correlations and finite temperature are also taken into account. The numerical procedure in the cubic box is described for the Skyrme Hartree-Fock as well as the relativistic Hartree-Fock approach. And finally, results for the crust of neutron stars and exotic nuclei are presented and discussed. (orig.)

EMACSS: Evolve Me A Cluster of StarS

Science.gov (United States)

Alexander, Poul E. R.; Gieles, Mark

2012-03-01

The star cluster evolution code Evolve Me A Cluster of StarS (EMACSS) is a simple yet physically motivated computational model that describes the evolution of some fundamental properties of star clusters in static tidal fields. The prescription is based upon the flow of energy within the cluster, which is a constant fraction of the total energy per half-mass relaxation time. According to Henon's predictions, this flow is independent of the precise mechanisms for energy production within the core, and therefore does not require a complete description of the many-body interactions therein. Dynamical theory and analytic descriptions of escape mechanisms is used to construct a series of coupled differential equations expressing the time evolution of cluster mass and radius for a cluster of equal-mass stars. These equations are numerically solved using a fourth-order Runge-Kutta integration kernel; the results were benchmarked against a data base of direct N-body simulations. EMACSS is publicly available and reproduces the N-body results to within 10 per cent accuracy for the entire post-collapse evolution of star clusters.

Parenting styles, feeding styles and food-related parenting practices in relation to toddlers' eating styles: A cluster-analytic approach

OpenAIRE

van der Horst, Klazine; Sleddens, Ester F. C.

2017-01-01

Introduction Toddlers? eating behaviors are influenced by the way parents interact with their children. The objective of this study was to explore how five major constructs of general parenting behavior cluster in parents of toddlers. These parenting clusters were further explored to see how they differed in the use of feeding strategies (i.e. feeding styles and food parenting practices) and by reported child eating styles. Methods An online survey with 1005 mothers/caregivers (legal guardian...

What prevents Chinese parents from reporting possible cases of child sexual abuse to authority? A holistic-interactionistic approach.

Science.gov (United States)

Xie, Qian Wen; Sun, Xiaoyue; Chen, Mengtong; Qiao, Dong Ping; Chan, Ko Ling

2017-02-01

The reporting of suspected CSA cases to authorities in a timely manner is important in preventing continued abuse and protecting abused children at early ages. The current study seeks to explore parents' intentions of reporting their own children's CSA experiences to authorities as well as their reporting willingness when they become aware of possible CSA cases happening to children in other families. Two rounds of semi-structured interviews were conducted among a sample of 26 parents in Beijing; these parents were purposefully selected so as to be diverse in terms of gender, age, and socioeconomic status. The data were analyzed thematically. The findings showed that the reporting of suspected CSA to authorities was a choice made by only a few Chinese parents; it was often even a last resort. By using a holistic-interactionistic approach, the interaction between Chinese parents' intentions of reporting CSA and the Chinese socio-cultural context was analyzed as a dynamic and continuously ongoing process. The impacts of the definition and perceptions of CSA on reporting, the balance of children's rights and parents' power, and the double effect of informal social control are discussed. The implications, both locally and globally, are also discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

More than teacher directed or child initiated: Preschool curriculum type, parent involvement, and children's outcomes in the child-parent centers.

Directory of Open Access Journals (Sweden)

Elizabeth Graue

2004-12-01

Full Text Available This study investigated the contributions of curriculum approach and parent involvement to the short- and long-term effects of preschool participation in the Title I Chicago Child-Parent Centers. Data came from the complete cohort of 989 low-income children (93% African American in the Chicago Longitudinal Study, who attended preschool in the 20 Child-Parent Centers in 1983-1985 and kindergarten in 1985-1986. We found that implementation of an instructional approach rated high by Head Teachers in teacher-directed and child-initiated activities was most consistently associated with children’s outcomes, including school readiness at kindergarten entry, reading achievement in third and eighth grades, and avoidance of grade retention. Parent involvement in school activities, as rated by teachers and by parents, was independently associated with child outcomes from school readiness at kindergarten entry to eighth grade reading achievement and grade retention above and beyond the influence of curriculum approach. Findings indicate that instructional approaches that blend a teacher-directed focus with child-initiated activities and parental school involvement are origins of the long-term effects of participation in the Child-Parent Centers.

A parent-child dyad approach to the assessment of health status and health-related quality of life in children with asthma.

Science.gov (United States)

Ungar, Wendy J; Boydell, Katherine; Dell, Sharon; Feldman, Brian M; Marshall, Deborah; Willan, Andrew; Wright, James G

2012-08-01

Assessment of health state and health-related quality of life (HR-QOL) are limited by a child's age and cognitive ability. Parent-proxy reports are known to differ from children's reports. Simultaneous assessment using a parent-child dyad is an alternative approach. Our objective was to assess the validity, reliability and responsiveness of a parent-child dyad approach to utility and HR-QOL assessment of paediatric asthma health states. The setting was specialist care in a hospital-based asthma clinic. Participants were 91 girls and boys with asthma aged 8 to 17 years and 91 parents. The intervention employed was parent-child dyad administration of the Health Utilities Index (HUI) 2 and 3, the Pediatric Quality of Life Inventory™ (PedsQL™) Core and Asthma modules, and the Pediatric Asthma Quality of Life Questionnaire (PAQLQ). Questionnaires were administered by interview to children and parents separately and then together as a dyad to assess the child's health state. The dyad interview was repeated at the next clinic visit. Dyad-child agreement was measured by intra-class correlation (ICC) coefficient; Spearman correlations were used to assess convergent validity. Test-retest reliability was assessed in 28 children who remained clinically stable between visits with a two-way ICC coefficient. Responsiveness to change from baseline was assessed with Spearman coefficients in 30 children who demonstrated clinical change between visits. There was no significant agreement between parent and child for the HUI2 or HUI3 whereas agreement between dyad and child was 0.55 (95% confidence interval [CI] 0.36, 0.69) for the HUI2 and 0.74 (95% CI 0.61, 0.82) for the HUI3 overall. With respect to dyad performance characteristics, both HUI2 and HUI3 overall scores demonstrated moderate convergent validity with the generic PedsQL™ Core domains (range r = 0.30-0.52; p  0.4; p < 0.05) was observed for dyad HUI2 total score change over time as correlated with dyad

A Qualitative Exploration Into the Parent-Child Feeding Relationship: How Parents of Preschoolers Divide the Responsibilities of Feeding with Their Children.

Science.gov (United States)

Loth, Katie A; Nogueira de Brito, Junia; Neumark-Sztainer, Dianne; Fisher, Jennifer Orlet; Berge, Jerica M

2018-04-05

To explore the extent to which parents divide responsibilities of feeding (what, when, where, how much, and whether) with their children and the factors that influence parents' approach to feeding. Individual interviews. Parents (n = 40) of preschoolers. Division of feeding responsibilities; motivation for feeding approach; challenges to feeding. Audio-recorded interviews were transcribed verbatim and coded using deductive and inductive content analysis. Parent's approaches to feeding varied widely. A few parents followed the Division of Responsibility approach closely. Instead, many parents gave their child more than the recommended amount of influence over what foods were served and offered children less than the recommended amount of autonomy over the whether and how much of eating. Meals and snacks were approached differently; parents exhibited less control over the timing of snacks as well as the types and amounts of foods eaten during snacks, compared with the control exhibited during meals. This data supports future research to understand the impact of this framework on child health outcomes when it is adhered to on all eating occasions, including snacks. Researchers and clinicians should collaborate to explore alternative frameworks that encourage parents to provide the structure and autonomy support shown to yield positive outcomes in children. Copyright © 2018 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Barium and Tc-poor S stars: Binary masqueraders among carbon stars

OpenAIRE

Jorissen, A.; Van Eck, S.

1997-01-01

The current understanding of the origin of barium and S stars is reviewed, based on new orbital elements and binary frequencies. The following questions are addressed: (i) Is binarity a necessary condition to produce a barium star? (ii) What is the mass transfer mode (wind accretion or RLOF?) responsible for their formation? (iii) Do barium stars form as dwarfs or as giants? (iv) Do barium stars evolve into Tc-poor S stars? (v) What is the relative frequency of Tc-rich and Tc-poor S stars?

Galaxies in the act of quenching star formation

Science.gov (United States)

Quai, Salvatore; Pozzetti, Lucia; Citro, Annalisa; Moresco, Michele; Cimatti, Andrea

2018-04-01

Detecting galaxies when their star-formation is being quenched is crucial to understand the mechanisms driving their evolution. We identify for the first time a sample of quenching galaxies selected just after the interruption of their star formation by exploiting the [O III] λ5007/Hα ratio and searching for galaxies with undetected [O III]. Using a sample of ˜174000 star-forming galaxies extracted from the SDSS-DR8 at 0.04 ≤ z growth of the quiescent population at these redshifts. Their main properties (i.e. star-formation rate, colours and metallicities) are comparable to those of the star-forming population, coherently with the hypothesis of recent quenching, but preferably reside in higher-density environments.Most candidates have morphologies similar to star-forming galaxies, suggesting that no morphological transformation has occurred yet. From a survival analysis we find a low fraction of candidates (˜ 0.58% of the star-forming population), leading to a short quenching timescale of tQ ˜ 50 Myr and an e-folding time for the quenching history of τQ ˜ 90 Myr, and their upper limits of tQ < 0.76 Gyr and τQ <1.5 Gyr, assuming as quenching galaxies 50% of objects without [O III] (˜7.5%).Our results are compatible with a 'rapid' quenching scenario of satellites galaxies due to the final phase of strangulation or ram-pressure stripping. This approach represents a robust alternative to methods used so far to select quenched galaxies (e.g. colours, specific star-formation rate, or post-starburst spectra).

Radio stars

International Nuclear Information System (INIS)

Hjellming, R.M.

1976-01-01

Any discussion of the radio emission from stars should begin by emphasizing certain unique problems. First of all, one must clarify a semantic confusion introduced into radio astronomy in the late 1950's when most new radio sources were described as radio stars. All of these early 'radio stars' were eventually identified with other galactic and extra-galactic objects. The study of true radio stars, where the radio emission is produced in the atmosphere of a star, began only in the 1960's. Most of the work on the subject has, in fact, been carried out in only the last few years. Because the real information about radio stars is quite new, it is not surprising that major aspects of the subject are not at all understood. For this reason this paper is organized mainly around three questions: what is the available observational information; what physical processes seem to be involved; and what working hypotheses look potentially fruitful. (Auth.)

TURBOVELOCITY STARS: KICKS RESULTING FROM THE TIDAL DISRUPTION OF SOLITARY STARS

International Nuclear Information System (INIS)

Manukian, Haik; Guillochon, James; Ramirez-Ruiz, Enrico; O'Leary, Ryan M.

2013-01-01

The centers of most known galaxies host supermassive black holes (SMBHs). In orbit around these black holes are a centrally concentrated distribution of stars, both in single and in binary systems. Occasionally, these stars are perturbed onto orbits that bring them close to the SMBH. If the star is in a binary system, the three-body interaction with the SMBH can lead to large changes in orbital energy, depositing one of the two stars on a tightly-bound orbit, and its companion into a hyperbolic orbit that may escape the galaxy. In this Letter, we show that the disruption of solitary stars can also lead to large positive increases in orbital energy. The kick velocity depends on the amount of mass the star loses at pericenter, but not on the ratio of black hole to stellar mass, and are at most the star's own escape velocity. We find that these kicks are usually too small to result in the ejection of stars from the Milky Way, but can eject the stars from the black hole's sphere of influence, reducing their probability of being disrupted again. We estimate that ∼ 10 5 stars, ∼ 1% of all stars within 10 pc of the galactic center, are likely to have had mass removed by the central black hole through tidal interaction, and speculate that these 'turbovelocity' stars will at first be redder, but eventually bluer, and always brighter than their unharassed peers.

[An influence of mental disorder in the child on the parents in the context of differentiated approaches to psychosocial interventions on childhood psychiatry].

Science.gov (United States)

Koren E V; Kupriyanova, T A; Dubinskaya, A O; Khairetdinov, O Z

2014-01-01

To specify parent reaction to a mental disorder in the child and to develop differential approaches to psychosocial family interventions. Authors studied parents (mostly mothers) of 140 children with schizophrenia spectrum disorders, 100 children with autistic disorders and 85 children with mental retardation. Along with psychiatric examination of the parents, it was used psychometric scales ECI and CGSQ. Authors specified emotional and behavioral characteristics of the parents' reaction as common for all diseases studied as well peculiar for separated forms of mental diseases in children. The factors (cognitive, emotional and behavioral) determining the targets of differentiated therapeutic interventions were singled out. The stress coping strategies for parents are formulated.

Authoritative parenting, parenting stress, and self-care in pre-adolescents with type 1 diabetes.

Science.gov (United States)

Monaghan, Maureen; Horn, Ivor B; Alvarez, Vanessa; Cogen, Fran R; Streisand, Randi

2012-09-01

Parent involvement in type 1 diabetes (T1DM) care leads to improved adherence; however, the manner in which parents approach illness management interactions with children must also be considered. It was hypothesized that greater use of an authoritative parenting style and less parenting stress would be associated with greater behavioral adherence and better metabolic control. Ninety-five primary caregivers of preadolescents (ages 8-11) with T1DM completed questionnaires assessing parenting style, pediatric parenting stress, and child behavioral adherence. Caregivers primarily self-identified as using an authoritative parenting style. Greater authoritative parenting was associated with greater behavioral adherence and less difficulty with pediatric parenting stress; no differences in metabolic control were observed. Greater engagement in authoritative parenting behaviors may contribute to increased age-appropriate child behavioral adherence and less pediatric parenting stress. Interventions highlighting diabetes-specific authoritative parenting techniques may enhance health outcomes and improve overall family functioning.

How Very Massive Metal-Free Stars Start Cosmological Reionization

Science.gov (United States)

Wise, John H.; Abel, Tom

2008-01-01

The initial conditions and relevant physics for the formation of the earliest galaxies are well specified in the concordance cosmology. Using ab initio cosmological Eulerian adaptive mesh refinement radiation hydrodynamical calculations, we discuss how very massive stars start the process of cosmological reionization. The models include nonequilibrium primordial gas chemistry and cooling processes and accurate radiation transport in the case B approximation using adaptively ray-traced photon packages, retaining the time derivative in the transport equation. Supernova feedback is modeled by thermal explosions triggered at parsec scales. All calculations resolve the local Jeans length by at least 16 grid cells at all times and as such cover a spatial dynamic range of approx.10(exp 6). These first sources of reionization are highly intermittent and anisotropic and first photoionize the small-scale voids surrounding the halos they form in, rather than the dense filaments they are embedded in. As the merging objects form larger, dwarf-sized galaxies, the escape fraction of UV radiation decreases and the H II regions only break out on some sides of the galaxies, making them even more anisotropic. In three cases, SN blast waves induce star formation in overdense regions that were formed earlier from ionization front instabilities. These stars form tens of parsecs away from the center of their parent DM halo. Approximately five ionizing photons are needed per sustained ionization when star formation in 10(exp 6) stellar Mass halos is dominant in the calculation. As the halos become larger than approx.10(exp 7) Stellar Mass, the ionizing photon escape fraction decreases, which in turn increases the number of photons per ionization to 15-50, in calculations with stellar feedback only. Radiative feedback decreases clumping factors by 25% when compared to simulations without star formation and increases the average temperature of ionized gas to values between 3000 and 10,000 K.

IRC -10414: a bow-shock-producing red supergiant star

Science.gov (United States)

Gvaramadze, V. V.; Menten, K. M.; Kniazev, A. Y.; Langer, N.; Mackey, J.; Kraus, A.; Meyer, D. M.-A.; Kamiński, T.

2014-01-01

Most runaway OB stars, like the majority of massive stars residing in their parent clusters, go through the red supergiant (RSG) phase during their lifetimes. Nonetheless, although many dozens of massive runaways were found to be associated with bow shocks, only two RSG bow-shock-producing stars, Betelgeuse and μ Cep, are known to date. In this paper, we report the discovery of an arc-like nebula around the late M-type star IRC -10414 using the SuperCOSMOS H-alpha Survey. Our spectroscopic follow-up of IRC -10414 with the Southern African Large Telescope (SALT) showed that it is a M7 supergiant, which supports previous claims on the RSG nature of this star based on observations of its maser emission. This was reinforced by our new radio- and (sub)millimetre-wavelength molecular line observations made with the Atacama Pathfinder Experiment 12-m telescope and the Effelsberg 100-m radio telescope, respectively. The SALT spectrum of the nebula indicates that its emission is the result of shock excitation. This finding along with the arc-like shape of the nebula and an estimate of the space velocity of IRC -10414 (≈70 ± 20 km s-1) imply the bow shock interpretation for the nebula. Thus, IRC -10414 represents the third case of a bow-shock-producing RSG and the first one with a bow shock visible at optical wavelengths. We discuss the smooth appearance of the bow shocks around IRC -10414 and Betelgeuse and propose that one of the necessary conditions for stability of bow shocks generated by RSGs is the ionization of the stellar wind. Possible ionization sources of the wind of IRC -10414 are proposed and discussed.

Interstellar clouds and the formation of stars

Energy Technology Data Exchange (ETDEWEB)

Alfven, H; Carlqvist, P [Kungliga Tekniska Hoegskolan, Stockholm (Sweden). Institutionen foer Plasmafysik

1978-05-01

Part I gives a survey of the drastic revision of cosmic plasma physics which is precipitated by the exploration of the magnetosphere through in situ measurements. The 'pseudo-plasma formalism', which until now has almost completely dominated theoretical astrophysics, must be replaced by an experimentally based approach involving the introduction of a number of neglected plasma phenomena, such as electric double layers, critical velocity, and pinch effect. The general belief that star light is the main ionizer is shown to be doubtful; hydromagnetic conversion of gravitational and kinetic energy may often be much more important. In Part II the revised plasma physics is applied to dark clouds and star formation. Magnetic fields do not necessarily counteract the contraction of a cloud; they may just as well 'pinch' the cloud. Magnetic compression may be the main mechanism for forming interstellar clouds and keeping them together. Part III treats the formation of stars in a dusty cosmic plasma cloud. Star formation is due to an instability, but it is very unlikely that it has anything to do with the Jeans instability. A reasonable mechanism is that the sedimentation of 'dust' (including solid bodies of different size) is triggering off a gravitationally assisted accretion. A 'stellesimal' accretion analogous to the planetesimal accretion leads to the formation of a star surrounded by a very low density hollow in the cloud. Matter falling in from the cloud towards the star is the raw material for the formation of planets and satellites.

"Wonderful" Star Reveals its Hot Nature

Science.gov (United States)

2005-04-01

For the first time an X-ray image of a pair of interacting stars has been made by NASA's Chandra X-ray Observatory. The ability to distinguish between the interacting stars - one a highly evolved giant star and the other likely a white dwarf - allowed a team of scientists to observe an X-ray outburst from the giant star and find evidence that a bridge of hot matter is streaming between the two stars. "Before this observation it was assumed that all the X-rays came from a hot disk surrounding a white dwarf, so the detection of an X-ray outburst from the giant star came as a surprise," said Margarita Karovska of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and lead author article in the latest Astrophysical Journal Letters describing this work. An ultraviolet image made by the Hubble Space Telescope was a key to identifying the location of the X-ray outburst with the giant star. X-ray studies of this system, called Mira AB, may also provide better understanding of interactions between other binary systems consisting of a "normal" star and a collapsed star such as a white dwarf, black hole or a neutron star, where the stellar objects and gas flow cannot be distinguished in an image. HST Ultraviolet Image of Mira HST Ultraviolet Image of Mira The separation of the X-rays from the giant star and the white dwarf was made possible by the superb angular resolution of Chandra, and the relative proximity of the star system at about 420 light years from Earth. The stars in Mira AB are about 6.5 billion miles apart, or almost twice the distance of Pluto from the Sun. Mira A (Mira) was named "The Wonderful" star in the 17th century because its brightness was observed to wax and wane over a period of about 330 days. Because it is in the advanced, red giant phase of a star's life, it has swollen to about 600 times that of the Sun and it is pulsating. Mira A is now approaching the stage where its nuclear fuel supply will be exhausted, and it will collapse

Radio stars

International Nuclear Information System (INIS)

Hjellming, R.M.; Gibson, D.M.

1985-01-01

Studies of stellar radio emission became an important field of research in the 1970's and have now expanded to become a major area of radio astronomy with the advent of new instruments such as the Very Large Array in New Mexico and transcontinental telescope arrays. This volume contains papers from the workshop on stellar continuum radio astronomy held in Boulder, Colorado, and is the first book on the rapidly expanding field of radio emission from stars and stellar systems. Subjects covered include the observational and theoretical aspects of stellar winds from both hot and cool stars, radio flares from active double star systems and red dwarf stars, bipolar flows from star-forming regions, and the radio emission from X-ray binaries. (orig.)

On the Spatially Resolved Star Formation History in M51. I. Hybrid UV+IR Star Formation Laws and IR Emission from Dust Heated by Old Stars

Science.gov (United States)

Eufrasio, R. T.; Lehmer, B. D.; Zezas, A.; Dwek, E.; Arendt, R. G.; Basu-Zych, A.; Wiklind, T.; Yukita, M.; Fragos, T.; Hornschemeier, A. E.; Markwardt, L.; Ptak, A.; Tzanavaris, P.

2017-12-01

We present LIGHTNING, a new spectral energy distribution fitting procedure, capable of quickly and reliably recovering star formation history (SFH) and extinction parameters. The SFH is modeled as discrete steps in time. In this work, we assumed lookback times of 0-10 Myr, 10-100 Myr, 0.1-1 Gyr, 1-5 Gyr, and 5-13.6 Gyr. LIGHTNING consists of a fully vectorized inversion algorithm to determine SFH step intensities and combines this with a grid-based approach to determine three extinction parameters. We apply our procedure to the extensive far-UV-to-far-IR photometric data of M51, convolved to a common spatial resolution and pixel scale, and make the resulting maps publicly available. We recover, for M51a, a peak star formation rate (SFR) between 0.1 and 5 Gyr ago, with much lower star formation activity over the past 100 Myr. For M51b, we find a declining SFR toward the present day. In the outskirt regions of M51a, which includes regions between M51a and M51b, we recover an SFR peak between 0.1 and 1 Gyr ago, which corresponds to the effects of the interaction between M51a and M51b. We utilize our results to (1) illustrate how UV+IR hybrid SFR laws vary across M51 and (2) provide first-order estimates for how the IR luminosity per unit stellar mass varies as a function of the stellar age. From the latter result, we find that IR emission from dust heated by stars is not always associated with young stars and that the IR emission from M51b is primarily powered by stars older than 5 Gyr.

A hybrid method for accurate star tracking using star sensor and gyros.

Science.gov (United States)

Lu, Jiazhen; Yang, Lie; Zhang, Hao

2017-10-01

Star tracking is the primary operating mode of star sensors. To improve tracking accuracy and efficiency, a hybrid method using a star sensor and gyroscopes is proposed in this study. In this method, the dynamic conditions of an aircraft are determined first by the estimated angular acceleration. Under low dynamic conditions, the star sensor is used to measure the star vector and the vector difference method is adopted to estimate the current angular velocity. Under high dynamic conditions, the angular velocity is obtained by the calibrated gyros. The star position is predicted based on the estimated angular velocity and calibrated gyros using the star vector measurements. The results of the semi-physical experiment show that this hybrid method is accurate and feasible. In contrast with the star vector difference and gyro-assisted methods, the star position prediction result of the hybrid method is verified to be more accurate in two different cases under the given random noise of the star centroid.

Star Products and Applications

OpenAIRE

Iida, Mari; Yoshioka, Akira

2010-01-01

Star products parametrized by complex matrices are defined. Especially commutative associative star products are treated, and star exponentials with respect to these star products are considered. Jacobi's theta functions are given as infinite sums of star exponentials. As application, several concrete identities are obtained by properties of the star exponentials.

Effective star tracking method based on optical flow analysis for star trackers.

Science.gov (United States)

Sun, Ting; Xing, Fei; Wang, Xiaochu; Li, Jin; Wei, Minsong; You, Zheng

2016-12-20

Benefiting from rapid development of imaging sensor technology, modern optical technology, and a high-speed computing chip, the star tracker's accuracy, dynamic performance, and update rate have been greatly improved with low power consumption and miniature size. The star tracker is currently one of the most competitive attitude measurement sensors. However, due to restrictions of the optical imaging system, difficulties still exist in moving star spot detection and star tracking when in special motion conditions. An effective star tracking method based on optical flow analysis for star trackers is proposed in this paper. Spot-based optical flow, based on a gray gradient between two adjacent star images, is analyzed to distinguish the star spot region and obtain an accurate star spot position so that the star tracking can keep continuous under high dynamic conditions. The obtained star vectors and extended Kalman filter (EKF) are then combined to conduct an angular velocity estimation to ensure region prediction of the star spot; this can be combined with the optical flow analysis result. Experiment results show that the method proposed in this paper has advantages in conditions of large angular velocity and large angular acceleration, despite the presence of noise. Higher functional density and better performance can be achieved; thus, the star tracker can be more widely applied in small satellites, remote sensing, and other complex space missions.

The NuSTAR Extragalactic Surveys: Overview And Catalog From The Cosmos Field

DEFF Research Database (Denmark)

Civano, F.; Hickox, R. C.; Puccetti, S.

2015-01-01

To provide the census of the sources contributing to the X-ray background peak above 10 keV, Nuclear Spectroscopic Telescope Array (NuSTAR) is performing extragalactic surveys using a three-tier "wedding cake" approach. We present the NuSTAR survey of the COSMOS field, the medium sensitivity...

A Functional Model for Counseling Parents of Gifted Students.

Science.gov (United States)

Dettmann, David F.; Colangelo, Nicholas

1980-01-01

The authors present a model of parent-school involvement in furthering the educational development of gifted students. The disadvantages and advantages of three counseling approaches are pointed out--parent centered approach, school centered approach, and the partnership approach. (SBH)

Food parenting and children's dietary behaviours: Approaching an integrated theoretical framework

Science.gov (United States)

We explored the differential influences of parental feeding styles and food parenting practices on children's dietary intake. Simple knowledge-based parent change interventions have generally not been shown to influence children's dietary intake. As a result, increasing attention has been given to t...

On the Maximum Mass of Accreting Primordial Supermassive Stars

Energy Technology Data Exchange (ETDEWEB)

Woods, T. E.; Heger, Alexander [Monash Centre for Astrophysics, School of Physics and Astronomy, Monash University, VIC 3800 (Australia); Whalen, Daniel J. [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth PO1 3FX (United Kingdom); Haemmerlé, Lionel; Klessen, Ralf S. [Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische. Astrophysik, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany)

2017-06-10

Supermassive primordial stars are suspected to be the progenitors of the most massive quasars at z ∼ 6. Previous studies of such stars were either unable to resolve hydrodynamical timescales or considered stars in isolation, not in the extreme accretion flows in which they actually form. Therefore, they could not self-consistently predict their final masses at collapse, or those of the resulting supermassive black hole seeds, but rather invoked comparison to simple polytropic models. Here, we systematically examine the birth, evolution, and collapse of accreting, non-rotating supermassive stars under accretion rates of 0.01–10 M {sub ⊙} yr{sup −1} using the stellar evolution code Kepler . Our approach includes post-Newtonian corrections to the stellar structure and an adaptive nuclear network and can transition to following the hydrodynamic evolution of supermassive stars after they encounter the general relativistic instability. We find that this instability triggers the collapse of the star at masses of 150,000–330,000 M {sub ⊙} for accretion rates of 0.1–10 M {sub ⊙} yr{sup −1}, and that the final mass of the star scales roughly logarithmically with the rate. The structure of the star, and thus its stability against collapse, is sensitive to the treatment of convection and the heat content of the outer accreted envelope. Comparison with other codes suggests differences here may lead to small deviations in the evolutionary state of the star as a function of time, that worsen with accretion rate. Since the general relativistic instability leads to the immediate death of these stars, our models place an upper limit on the masses of the first quasars at birth.

Integrating a family-focused approach into child obesity prevention: Rationale and design for the My Parenting SOS study randomized control trial

Directory of Open Access Journals (Sweden)

Campbell Marci

2011-06-01

Full Text Available Abstract Background More than 20% of US children ages 2-5 yrs are classified as overweight or obese. Parents greatly influence the behaviors their children adopt, including those which impact weight (e.g., diet and physical activity. Unfortunately, parents often fail to recognize the risk for excess weight gain in young children, and may not be motivated to modify behavior. Research is needed to explore intervention strategies that engage families with young children and motivate parents to adopt behaviors that will foster healthy weight development. Methods This study tests the efficacy of the 35-week My Parenting SOS intervention. The intervention consists of 12 sessions: initial sessions focus on general parenting skills (stress management, effective parenting styles, child behavior management, coparenting, and time management and later sessions apply these skills to promote healthier eating and physical activity habits. The primary outcome is change in child percent body fat. Secondary measures assess parent and child dietary intake (three 24-hr recalls and physical activity (accelerometry, general parenting style and practices, nutrition- and activity-related parenting practices, and parent motivation to adopt healthier practices. Discussion Testing of these new approaches contributes to our understanding of how general and weight-specific parenting practices influence child weight, and whether or not they can be changed to promote healthy weight trajectories. Trial Registration ClinicalTrials.gov: NCT00998348

Integrating a family-focused approach into child obesity prevention: rationale and design for the My Parenting SOS study randomized control trial.

Science.gov (United States)

Ward, Dianne S; Vaughn, Amber E; Bangdiwala, Kant I; Campbell, Marci; Jones, Deborah J; Panter, Abigail T; Stevens, June

2011-06-05

More than 20% of US children ages 2-5 yrs are classified as overweight or obese. Parents greatly influence the behaviors their children adopt, including those which impact weight (e.g., diet and physical activity). Unfortunately, parents often fail to recognize the risk for excess weight gain in young children, and may not be motivated to modify behavior. Research is needed to explore intervention strategies that engage families with young children and motivate parents to adopt behaviors that will foster healthy weight development. This study tests the efficacy of the 35-week My Parenting SOS intervention. The intervention consists of 12 sessions: initial sessions focus on general parenting skills (stress management, effective parenting styles, child behavior management, coparenting, and time management) and later sessions apply these skills to promote healthier eating and physical activity habits. The primary outcome is change in child percent body fat. Secondary measures assess parent and child dietary intake (three 24-hr recalls) and physical activity (accelerometry), general parenting style and practices, nutrition- and activity-related parenting practices, and parent motivation to adopt healthier practices. Testing of these new approaches contributes to our understanding of how general and weight-specific parenting practices influence child weight, and whether or not they can be changed to promote healthy weight trajectories. ClinicalTrials.gov: NCT00998348.

Exploring the SDSS Data Set with Linked Scatter Plots. I. EMP, CEMP, and CV Stars

Energy Technology Data Exchange (ETDEWEB)

Carbon, Duane F.; Henze, Christopher; Nelson, Bron C., E-mail: Duane.F.Carbon@nasa.gov [NASA Ames Research Center, NASA Advanced Supercomputing Facility, Moffett Field, CA, 94035-1000 (United States)

2017-02-01

We present the results of a search for extremely metal-poor (EMP), carbon-enhanced metal-poor (CEMP), and cataclysmic variable (CV) stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets, and it can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct our search using the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, CEMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He ii emission CV stars found by the LSP approach that have not yet been discussed in the literature.

An Experimental Approach to the Joint Effects of Relations with Partner, Friends and Parents on Happiness

Science.gov (United States)

Theuns, P.; Verresen, N.; Mairesse, O.; Goossens, R.; Michiels, L.; Peeters, E.; Wastiau, M.

2010-01-01

Personal relations constitute an important life domain and satisfaction therein affects happiness in people. In an experimental approach with a 3x3x3 vignettes study in which 103 first year psychology students participated, the contribution of the quality of relationships with parents, friends, and a partner are studied. It is found that the…

Parental Engagement: Beyond Parental Involvement in Science Education

Science.gov (United States)

St. Louis, Kathleen

This study critically analyzes parents' complex stories of engagement in school and science education. The purpose is not to essentialize parental involvement, but rather to understand the processes of parental involvement and push forward the current discourse on the engagement of low-income minority and immigrant parents in schools and specifically science education. Employing critical grounded theory methods over a four-year span, this study had three areas of focus. First, voices of marginalized parents in the context of various spaces within the school system are examined. Using a qualitative approach, informal, formal, and research spaces were explored along with how minority parents express voice in these various spaces. Findings indicate parents drew on capital to express voice differently in different spaces, essentially authoring new spaces or the type of engagement in existing spaces. Second, the values and beliefs of traditionally marginalized people, the Discourse of mainstream society, and how they can inform a third, more transformative space for parental engagement in science are considered. The voices of low-income, marginalized parents around science and parental engagement (i.e., first space) are contrasted with the tenets of major national science policy documents (i.e., second space). Findings indicate a disparity between the pathways of engagement for low-income parents and policymakers who shape science education. Third, methodological questions of responsibility and assumption in qualitative research are explored. The author's complex struggle to make sense of her positionality, responsibilities, and assumptions as a researcher is chronicled. Findings focused on insider/outsider issues and implications for culturally sensitive research are discussed. Finally, the implications for policy, teaching, and research are discussed.

Parenting Coordinators' Practices Recommendations: A Qualitative Study

OpenAIRE

Hirsch, Barbara Phyllis

2016-01-01

This qualitative study used a phenomenological approach to understand the experiences of seven parenting coordinators in using parenting coordination practices that they have found to be effective and would recommend to other parenting coordinators to achieve the following goals: educating parents, increasing the quality of parenting and co-parenting, managing conflict, and involving children and other family members in the process of parenting coordination. Data were collected with semi-str...

Formation of stars and star clusters in colliding galaxies

International Nuclear Information System (INIS)

Belles, Pierre-Emmanuel

2012-01-01

Mergers are known to be essential in the formation of large-scale structures and to have a significant role in the history of galaxy formation and evolution. Besides a morphological transformation, mergers induce important bursts of star formation. These starburst are characterised by high Star Formation Efficiencies (SFEs) and Specific Star Formation Rates, i.e., high Star Formation Rates (SFR) per unit of gas mass and high SFR per unit of stellar mass, respectively, compared to spiral galaxies. At all redshifts, starburst galaxies are outliers of the sequence of star-forming galaxies defined by spiral galaxies. We have investigated the origin of the starburst-mode of star formation, in three local interacting systems: Arp 245, Arp 105 and NGC 7252. We combined high-resolution JVLA observations of the 21-cm line, tracing the HI diffuse gas, with UV GALEX observations, tracing the young star-forming regions. We probe the local physical conditions of the Inter-Stellar Medium (ISM) for independent star-forming regions and explore the atomic-to-dense gas transformation in different environments. The SFR/HI ratio is found to be much higher in central regions, compared to outer regions, showing a higher dense gas fraction (or lower HI gas fraction) in these regions. In the outer regions of the systems, i.e., the tidal tails, where the gas phase is mostly atomic, we find SFR/HI ratios higher than in standard HI-dominated environments, i.e., outer discs of spiral galaxies and dwarf galaxies. Thus, our analysis reveals that the outer regions of mergers are characterised by high SFEs, compared to the standard mode of star formation. The observation of high dense gas fractions in interacting systems is consistent with the predictions of numerical simulations; it results from the increase of the gas turbulence during a merger. The merger is likely to affect the star-forming properties of the system at all spatial scales, from large scales, with a globally enhanced turbulence

Authoritative Parenting, Parenting Stress, and Self-Care in Pre-Adolescents with Type 1 Diabetes

Science.gov (United States)

Monaghan, Maureen; Horn, Ivor B.; Alvarez, Vanessa; Cogen, Fran R.; Streisand, Randi

2012-01-01

Parent involvement in type 1 diabetes (T1DM) care leads to improved adherence; however, the manner in which parents approach illness management interactions with children must also be considered. It was hypothesized that greater use of an authoritative parenting style and less parenting stress would be associated with greater behavioral adherence and better metabolic control. Ninety-five primary caregivers of preadolescents (ages 8-11) with T1DM completed questionnaires assessing parenting style, pediatric parenting stress, and child behavioral adherence. Caregivers primarily self-identified as using an authoritative parenting style. Greater authoritative parenting was associated with greater behavioral adherence and less difficulty with pediatric parenting stress; no differences in metabolic control were observed. Greater engagement in authoritative parenting behaviors may contribute to increased age-appropriate child behavioral adherence and less pediatric parenting stress. Interventions highlighting diabetes-specific authoritative parenting techniques may enhance health outcomes and improve overall family functioning. PMID:22350495

Stars Just Got Bigger - A 300 Solar Mass Star Uncovered

Science.gov (United States)

2010-07-01

Using a combination of instruments on ESO's Very Large Telescope, astronomers have discovered the most massive stars to date, one weighing at birth more than 300 times the mass of the Sun, or twice as much as the currently accepted limit of 150 solar masses. The existence of these monsters - millions of times more luminous than the Sun, losing weight through very powerful winds - may provide an answer to the question "how massive can stars be?" A team of astronomers led by Paul Crowther, Professor of Astrophysics at the University of Sheffield, has used ESO's Very Large Telescope (VLT), as well as archival data from the NASA/ESA Hubble Space Telescope, to study two young clusters of stars, NGC 3603 and RMC 136a in detail. NGC 3603 is a cosmic factory where stars form frantically from the nebula's extended clouds of gas and dust, located 22 000 light-years away from the Sun (eso1005). RMC 136a (more often known as R136) is another cluster of young, massive and hot stars, which is located inside the Tarantula Nebula, in one of our neighbouring galaxies, the Large Magellanic Cloud, 165 000 light-years away (eso0613). The team found several stars with surface temperatures over 40 000 degrees, more than seven times hotter than our Sun, and a few tens of times larger and several million times brighter. Comparisons with models imply that several of these stars were born with masses in excess of 150 solar masses. The star R136a1, found in the R136 cluster, is the most massive star ever found, with a current mass of about 265 solar masses and with a birthweight of as much as 320 times that of the Sun. In NGC 3603, the astronomers could also directly measure the masses of two stars that belong to a double star system [1], as a validation of the models used. The stars A1, B and C in this cluster have estimated masses at birth above or close to 150 solar masses. Very massive stars produce very powerful outflows. "Unlike humans, these stars are born heavy and lose weight as

The Destructive Birth of Massive Stars and Massive Star Clusters

Science.gov (United States)

Rosen, Anna; Krumholz, Mark; McKee, Christopher F.; Klein, Richard I.; Ramirez-Ruiz, Enrico

2017-01-01

Massive stars play an essential role in the Universe. They are rare, yet the energy and momentum they inject into the interstellar medium with their intense radiation fields dwarfs the contribution by their vastly more numerous low-mass cousins. Previous theoretical and observational studies have concluded that the feedback associated with massive stars' radiation fields is the dominant mechanism regulating massive star and massive star cluster (MSC) formation. Therefore detailed simulation of the formation of massive stars and MSCs, which host hundreds to thousands of massive stars, requires an accurate treatment of radiation. For this purpose, we have developed a new, highly accurate hybrid radiation algorithm that properly treats the absorption of the direct radiation field from stars and the re-emission and processing by interstellar dust. We use our new tool to perform a suite of three-dimensional radiation-hydrodynamic simulations of the formation of massive stars and MSCs. For individual massive stellar systems, we simulate the collapse of massive pre-stellar cores with laminar and turbulent initial conditions and properly resolve regions where we expect instabilities to grow. We find that mass is channeled to the massive stellar system via gravitational and Rayleigh-Taylor (RT) instabilities. For laminar initial conditions, proper treatment of the direct radiation field produces later onset of RT instability, but does not suppress it entirely provided the edges of the radiation-dominated bubbles are adequately resolved. RT instabilities arise immediately for turbulent pre-stellar cores because the initial turbulence seeds the instabilities. To model MSC formation, we simulate the collapse of a dense, turbulent, magnetized Mcl = 106 M⊙ molecular cloud. We find that the influence of the magnetic pressure and radiative feedback slows down star formation. Furthermore, we find that star formation is suppressed along dense filaments where the magnetic field is

First stars X. The nature of three unevolved carbon-enhanced metal-poor stars

DEFF Research Database (Denmark)

Sivarani, T.; Beers, T.C.; Bonifacio, P.

2006-01-01

Stars: abundances, stars: population II, Galaxy: abundances, stars: AGB and post-AGB Udgivelsesdato: Nov.......Stars: abundances, stars: population II, Galaxy: abundances, stars: AGB and post-AGB Udgivelsesdato: Nov....

False star detection and isolation during star tracking based on improved chi-square tests.

Science.gov (United States)

Zhang, Hao; Niu, Yanxiong; Lu, Jiazhen; Yang, Yanqiang; Su, Guohua

2017-08-01

The star sensor is a precise attitude measurement device for a spacecraft. Star tracking is the main and key working mode for a star sensor. However, during star tracking, false stars become an inevitable interference for star sensor applications, which may result in declined measurement accuracy. A false star detection and isolation algorithm in star tracking based on improved chi-square tests is proposed in this paper. Two estimations are established based on a Kalman filter and a priori information, respectively. The false star detection is operated through adopting the global state chi-square test in a Kalman filter. The false star isolation is achieved using a local state chi-square test. Semi-physical experiments under different trajectories with various false stars are designed for verification. Experiment results show that various false stars can be detected and isolated from navigation stars during star tracking, and the attitude measurement accuracy is hardly influenced by false stars. The proposed algorithm is proved to have an excellent performance in terms of speed, stability, and robustness.

StarGuides Plus

Science.gov (United States)

Heck, A.

StarGuides Plus represents the most comprehensive and accurately validated collection of practical data on organizations involved in astronomy, related space sciences and other related fields. This invaluable reference source (and its companion volume, StarBriefs Plus) should be on the reference shelf of every library, organization or individual with any interest in these areas. The coverage includes relevant universities, scientific committees, institutions, associations, societies, agencies, companies, bibliographic services, data centers, museums, dealers, distributors, funding organizations, journals, manufacturers, meteorological services, national norms & standard institutes, parent associations & societies, publishers, software producers & distributors, and so on. Besides astronomy and associated space sciences, related fields such as aeronautics, aeronomy, astronautics, atmospheric sciences, chemistry, communications, computer sciences, data processing, education, electronics, engineering, energetics, environment, geodesy, geophysics, information handling, management, mathematics, meteorology, optics, physics, remote sensing, and so on, are also covered where appropriate. After some thirty years in continuous compilation, verification and updating, StarGuides Plus currently gathers together some 6,000 entries from 100 countries. The information is presented in a clear, uncluttered manner for direct and easy use. For each entry, all practical data are listed: city, postal and electronic-mail addresses, telephone and fax numbers, URLs for WWW access, foundation years, numbers of members and/or numbers of staff, main activities, publications titles (with frequencies, ISS-Numbers and circulations), names and geographical coordinates of observing sites, names of planetariums, awards (prizes and/or distinctions) granted, etc. The entries are listed alphabetically in each country. An exhaustive index gives a breakdown not only by different designations and

Symmetry energy, unstable nuclei and neutron star crusts

Energy Technology Data Exchange (ETDEWEB)

Iida, Kei [Kochi University, Department of Natural Science, Kochi (Japan); RIKEN Nishina Center, Saitama (Japan); Oyamatsu, Kazuhiro [RIKEN Nishina Center, Saitama (Japan); Aichi Shukutoku University, Department of Human Informatics, Aichi (Japan)

2014-02-15

The phenomenological approach to inhomogeneous nuclear matter is useful to describe fundamental properties of atomic nuclei and neutron star crusts in terms of the equation of state of uniform nuclear matter. We review a series of researches that we have developed by following this approach. We start with more than 200 equations of state that are consistent with empirical masses and charge radii of stable nuclei and then apply them to describe matter radii and masses of unstable nuclei, proton elastic scattering and total reaction cross sections off unstable nuclei, and nuclei in neutron star crusts including nuclear pasta. We finally discuss the possibility of constraining the density dependence of the symmetry energy from experiments on unstable nuclei and even observations of quasi-periodic oscillations in giant flares of soft gamma-ray repeaters. (orig.)

White Dwarf Stars

OpenAIRE

Kepler, S. O.; Romero, Alejandra Daniela; Pelisoli, Ingrid; Ourique, Gustavo

2017-01-01

White dwarf stars are the final stage of most stars, born single or in multiple systems. We discuss the identification, magnetic fields, and mass distribution for white dwarfs detected from spectra obtained by the Sloan Digital Sky Survey up to Data Release 13 in 2016, which lead to the increase in the number of spectroscopically identified white dwarf stars from 5000 to 39000. This number includes only white dwarf stars with log g >= 6.5 stars, i.e., excluding the Extremely Low Mass white dw...

THE PREVALENCE AND IMPACT OF WOLF–RAYET STARS IN EMERGING MASSIVE STAR CLUSTERS

Energy Technology Data Exchange (ETDEWEB)

Sokal, Kimberly R.; Johnson, Kelsey E.; Indebetouw, Rémy [Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903 (United States); Massey, Philip, E-mail: krs9tb@virginia.edu [Lowell Observatory, 1400 W Mars Hill Road, Flagstaff, AZ 86001 (United States)

2016-08-01

We investigate Wolf–Rayet (WR) stars as a source of feedback contributing to the removal of natal material in the early evolution of massive star clusters. Despite previous work suggesting that massive star clusters clear out their natal material before the massive stars evolve into the WR phase, WR stars have been detected in several emerging massive star clusters. These detections suggest that the timescale for clusters to emerge can be at least as long as the time required to produce WR stars (a few million years), and could also indicate that WR stars may be providing the tipping point in the combined feedback processes that drive a massive star cluster to emerge. We explore the potential overlap between the emerging phase and the WR phase with an observational survey to search for WR stars in emerging massive star clusters hosting WR stars. We select candidate emerging massive star clusters from known radio continuum sources with thermal emission and obtain optical spectra with the 4 m Mayall Telescope at Kitt Peak National Observatory and the 6.5 m MMT.{sup 4} We identify 21 sources with significantly detected WR signatures, which we term “emerging WR clusters.” WR features are detected in ∼50% of the radio-selected sample, and thus we find that WR stars are commonly present in currently emerging massive star clusters. The observed extinctions and ages suggest that clusters without WR detections remain embedded for longer periods of time, and may indicate that WR stars can aid, and therefore accelerate, the emergence process.

Egyptian "Star Clocks"

Science.gov (United States)

Symons, Sarah

Diagonal, transit, and Ramesside star clocks are tables of astronomical information occasionally found in ancient Egyptian temples, tombs, and papyri. The tables represent the motions of selected stars (decans and hour stars) throughout the Egyptian civil year. Analysis of star clocks leads to greater understanding of ancient Egyptian constellations, ritual astronomical activities, observational practices, and pharaonic chronology.

A dynamical description of neutron star crusts

International Nuclear Information System (INIS)

Mota, V de la; S, F; Eudes, Ph

2013-01-01

Neutron Stars are natural laboratories where fundamental properties of matter under extreme conditions can be explored. Modern nuclear physics input as well as many-body theories are valuable tools which may allow us to improve our understanding of the physics of those compact objects. In this work the occurrence of exotic structures in the outermost layers of neutron stars is investigated within the framework of a microscopic model. In this approach the nucleonic dynamics is described by a time-dependent mean field approach at around zero temperature. Starting from an initial crystalline lattice of nuclei at subnuclear densities the system evolves toward a manifold of self-organized structures with different shapes and similar energies. These structures are studied in terms of a phase diagram in density and the corresponding sensitivity to the isospin-dependent part of the equation of state and to the isotopic composition is investigated.

Symbiotic stars

International Nuclear Information System (INIS)

Kafatos, M.; Michalitsianos, A.G.

1984-01-01

Among the several hundred million binary systems estimated to lie within 3000 light years of the solar system, a tiny fraction, no more than a few hundred, belong to a curious subclass whose radiation has a wavelength distribution so peculiar that it long defied explanation. Such systems radiate strongly in the visible region of the spectrum, but some of them do so even more strongly at both shorter and longer wavelengths: in the ultraviolet region and in the infrared and radio regions. This odd distribution of radiation is best explained by the pairing of a cool red giant star and an intensely hot small star that is virtually in contact with its larger companion. Such objects have become known as symbiotic stars. On photographic plate only the giant star can be discerned, but evidence for the existence of the hot companion has been supplied by satellite-born instruments capable of detecting ultraviolet radiation. The spectra of symbiotic stars indicate that the cool red giant is surrounded by a very hot ionized gas. Symbiotic stars also flared up in outbursts indicating the ejection of material in the form of a shell or a ring. Symbiotic stars may therefore represent a transitory phase in the evolution of certain types of binary systems in which there is substantial transfer of matter from the larger partner to the smaller

Observations of CO and OI in stars in globular clusters

International Nuclear Information System (INIS)

Wallerstein, G.; Pilachowski, C.

1978-01-01

Since studies at classification dispersion and early analyses of high dispersion spectra have yielded little quantitative data on the abundances of C, N, and O in globular clusters the authors have been endeavoring to establish their abundances in stars in several clusters. The problem has been approached in two ways, by observing the 2.3 micron CO bands and the 6300 A [OI] line in individual stars in globular clusters. (Auth.)

["Nicht von schlechten Eltern - NischE": A Family Orientated Collaborative Care Approach to Support Children in Families with Mentally Ill Parents].

Science.gov (United States)

Wabnitz, Pascal; Kronmüller, Klaus-Thomas; Wieskus-Friedemann, Erwin; Kliem, Sabine; Hoppmann, Johannes; Burek, Monika; Löhr, Michael; Kemper, Ulrich; Nienaber, André

2016-11-01

"Nicht von schlechten Eltern - NischE": A Family Orientated Collaborative Care Approach to Support Children in Families with Mentally Ill Parents The present work describes the setting- and multi-professional offer "NischE" in Gütersloh, a systemic approach for the care of children and their mentally ill parents. Children of mentally ill parents are a special risk group for developing their own mental illness. The aim of the collaborative care model between child and adolescent psychiatry, youth services and adult psychiatry is to enable affected families in terms of family-focused practice a low threshold access to different services. For this purpose, two positions have been created to advise the affected families and support access to the help system in the sense of a systemic case management in a project. The article describes the background and the need for the development of the offer, the current scientific knowledge base on the subject and illustrates the procedure using a case study from practice.

Atmospheric Parameters and Metallicities for 2191 Stars in the Globular Cluster M4

Science.gov (United States)

Malavolta, Luca; Sneden, Christopher; Piotto, Giampaolo; Milone, Antonino P.; Bedin, Luigi R.; Nascimbeni, Valerio

2014-02-01

We report new metallicities for stars of Galactic globular cluster M4 using the largest number of stars ever observed at high spectral resolution in any cluster. We analyzed 7250 spectra for 2771 cluster stars gathered with the Very Large Telescope (VLT) FLAMES+GIRAFFE spectrograph at VLT. These medium-resolution spectra cover a small wavelength range, and often have very low signal-to-noise ratios. We approached this data set by reconsidering the whole method of abundance analysis of large stellar samples from beginning to end. We developed a new algorithm that automatically determines the atmospheric parameters of a star. Nearly all of the data preparation steps for spectroscopic analyses are processed on the syntheses, not the observed spectra. For 322 red giant branch (RGB) stars with V 14.7, we obtain lang[Fe/H]rang = -1.16 (σ = 0.09) after fixing the microturbulent velocity. These values are consistent with previous studies that have performed detailed analyses of brighter RGB stars at higher spectroscopic resolution and wavelength coverage. It is not clear if the small mean metallicity difference between brighter and fainter M4 members is real or is the result of the low signal-to-noise characteristics of the fainter stars. The strength of our approach is shown by recovering a metallicity close to a single value for more than 2000 stars, using a data set that is non-optimal for atmospheric analyses. This technique is particularly suitable for noisy data taken in difficult observing conditions.

Star tracking method based on multiexposure imaging for intensified star trackers.

Science.gov (United States)

Yu, Wenbo; Jiang, Jie; Zhang, Guangjun

2017-07-20

The requirements for the dynamic performance of star trackers are rapidly increasing with the development of space exploration technologies. However, insufficient knowledge of the angular acceleration has largely decreased the performance of the existing star tracking methods, and star trackers may even fail to track under highly dynamic conditions. This study proposes a star tracking method based on multiexposure imaging for intensified star trackers. The accurate estimation model of the complete motion parameters, including the angular velocity and angular acceleration, is established according to the working characteristic of multiexposure imaging. The estimation of the complete motion parameters is utilized to generate the predictive star image accurately. Therefore, the correct matching and tracking between stars in the real and predictive star images can be reliably accomplished under highly dynamic conditions. Simulations with specific dynamic conditions are conducted to verify the feasibility and effectiveness of the proposed method. Experiments with real starry night sky observation are also conducted for further verification. Simulations and experiments demonstrate that the proposed method is effective and shows excellent performance under highly dynamic conditions.

Extended high circular polarization in the Orion massive star forming region: implications for the origin of homochirality in the solar system.

Science.gov (United States)

Fukue, Tsubasa; Tamura, Motohide; Kandori, Ryo; Kusakabe, Nobuhiko; Hough, James H; Bailey, Jeremy; Whittet, Douglas C B; Lucas, Philip W; Nakajima, Yasushi; Hashimoto, Jun

2010-06-01

We present a wide-field (approximately 6' x 6') and deep near-infrared (K(s) band: 2.14 mum) circular polarization image in the Orion nebula, where massive stars and many low-mass stars are forming. Our results reveal that a high circular polarization region is spatially extended (approximately 0.4 pc) around the massive star-forming region, the BN/KL nebula. However, other regions, including the linearly polarized Orion bar, show no significant circular polarization. Most of the low-mass young stars do not show detectable extended structure in either linear or circular polarization, in contrast to the BN/KL nebula. If our solar system formed in a massive star-forming region and was irradiated by net circularly polarized radiation, then enantiomeric excesses could have been induced, through asymmetric photochemistry, in the parent bodies of the meteorites and subsequently delivered to Earth. These could then have played a role in the development of biological homochirality on Earth.

B- AND A-TYPE STARS IN THE TAURUS-AURIGA STAR-FORMING REGION

International Nuclear Information System (INIS)

Mooley, Kunal; Hillenbrand, Lynne; Rebull, Luisa; Padgett, Deborah; Knapp, Gillian

2013-01-01

We describe the results of a search for early-type stars associated with the Taurus-Auriga molecular cloud complex, a diffuse nearby star-forming region noted as lacking young stars of intermediate and high mass. We investigate several sets of possible O, B, and early A spectral class members. The first is a group of stars for which mid-infrared images show bright nebulae, all of which can be associated with stars of spectral-type B. The second group consists of early-type stars compiled from (1) literature listings in SIMBAD, (2) B stars with infrared excesses selected from the Spitzer Space Telescope survey of the Taurus cloud, (3) magnitude- and color-selected point sources from the Two Micron All Sky Survey, and (4) spectroscopically identified early-type stars from the Sloan Digital Sky Survey coverage of the Taurus region. We evaluated stars for membership in the Taurus-Auriga star formation region based on criteria involving: spectroscopic and parallactic distances, proper motions and radial velocities, and infrared excesses or line emission indicative of stellar youth. For selected objects, we also model the scattered and emitted radiation from reflection nebulosity and compare the results with the observed spectral energy distributions to further test the plausibility of physical association of the B stars with the Taurus cloud. This investigation newly identifies as probable Taurus members three B-type stars: HR 1445 (HD 28929), τ Tau (HD 29763), 72 Tau (HD 28149), and two A-type stars: HD 31305 and HD 26212, thus doubling the number of stars A5 or earlier associated with the Taurus clouds. Several additional early-type sources including HD 29659 and HD 283815 meet some, but not all, of the membership criteria and therefore are plausible, though not secure, members.

Life of a star

International Nuclear Information System (INIS)

Henbest, Nigel.

1988-01-01

The paper concerns the theory of stellar evolution. A description is given of:- how a star is born, main sequence stars, red giants, white dwarfs, supernovae, neutron stars and black holes. A brief explanation is given of how the death of a star as a supernova can trigger off the birth of a new generation of stars. Classification of stars and the fate of our sun, are also described. (U.K.)

A search for lithium-rich giant stars

International Nuclear Information System (INIS)

Brown, J.A.; Sneden, C.; Lambert, D.L.; Dutchover, E. Jr.

1989-01-01

Lithium abundances or upper limits have been determined for 644 bright G-K giant stars selected from the DDO photometric catalog. Two of these giants possess surface lithium abundances approaching the cosmic value of the interstellar medium and young main-sequence stars, and eight more giants have Li contents far in excess of standard predictions. At least some of these Li-rich giants are shown to be evolved to the stage of having convectively mixed envelopes, either from the direct evidence of low surface carbon isotope ratios, or from the indirect evidence of their H-R diagram positions. Suggestions are given for the unique conditions that might have allowed these stars to produce or accrete new lithium for their surface layers, or simply to preserve from destruction their initial lithium contents. The lithium abundance of the remaining stars demonstrates that giants only very rarely meet the expectations of standard first dredge-up theories; the average extra Li destruction required is about 1.5 dex. The evolutionary states of these giants and their average masses are discussed briefly, and the Li distribution of the giants is compared to predictions of Galactic chemical evolution. 110 refs

Heavy Metal Stars

Science.gov (United States)

2001-08-01

atomic mass and hence, increasing positive charge of the nuclei, the electric repulsion between the nuclei becomes stronger and stronger. In fact, the fusion process only works up to a certain mass limit, corresponding to the element Iron [2]. All elements that are heavier than Iron cannot be produced via this path. But then, how were those heavy elements we now find on the Earth produced in the first place? From where comes the Zirconium in artificial diamonds, the Barium that colours fireworks, the Tungsten in the filaments in electric bulbs? Which process made the Lead in your car battery? Beyond iron The production of elements heavier than Iron takes place by adding neutrons to the atomic nuclei . These neutral particles do not feel any electrical repulsion from the charged nuclei. They can therefore easily approach them and thereby create heavier nuclei. This is indeed the way the heaviest chemical elements are built up. There are actually two different stellar environments where this process of "neutron capture" can happen. One place where this process occurs is inside very massive stars when they explode as supernovae . In such a dramatic event, the build-up proceeds very rapidly, via the so-called "r-process" ( "r" for rapid ). The AGB stars But not all heavy elements are created in such an explosive way. A second possibility follows a more "peaceful" road. It takes place in rather normal stars, when they burn their Helium towards the end of their lives. In the so-called "s-process" ( "s" for slow ), heavier elements are then produced by a rather gentle addition of neutral neutrons to atomic nuclei. In fact, roughly half of all the elements heavier than Iron are believed to be synthesized by this process during the late evolutionary phases of stars. This process takes place during a specific stage of stellar evolution, known as the "AGB" phase [3]. It occurs just before an old star expels its gaseous envelope into the surrounding interstellar space and sometime

Parental distress, parenting practices, and child adaptive outcomes following traumatic brain injury.

Science.gov (United States)

Micklewright, Jackie L; King, Tricia Z; O'Toole, Kathleen; Henrich, Chris; Floyd, Frank J

2012-03-01

Moderate and severe pediatric traumatic brain injuries (TBI) are associated with significant familial distress and child adaptive sequelae. Our aim was to examine the relationship between parental psychological distress, parenting practices (authoritarian, permissive, authoritative), and child adaptive functioning 12-36 months following TBI or orthopedic injury (OI). Injury type was hypothesized to moderate the relationship between parental distress and child adaptive functioning, demonstrating a significantly stronger relationship in the TBI relative to OI group. Authoritarian parenting practices were hypothesized to mediate relationship between parental distress and child adaptive functioning across groups. Groups (TBI n = 21, OI n = 23) did not differ significantly on age at injury, time since injury, sex, race, or SES. Parents completed the Brief Symptom Inventory, Parenting Practices Questionnaire, and Vineland-II. Moderation and mediation hypotheses were tested using hierarchical multiple regression and a bootstrapping approach, respectively. Results supported moderation and revealed that higher parental psychological distress was associated with lower child adaptive functioning in the TBI group only. Mediation results indicated that higher parental distress was associated with authoritarian parenting practices and lower adaptive functioning across groups. Results suggest that parenting practices are an important area of focus for studies attempting to elucidate the relationship between parent and child functioning following TBI.

Flare stars

International Nuclear Information System (INIS)

Nicastro, A.J.

1981-01-01

The least massive, but possibly most numerous, stars in a galaxy are the dwarf M stars. It has been observed that some of these dwarfs are characterized by a short increase in brightness. These stars are called flare stars. These flare stars release a lot of energy in a short amount of time. The process producing the eruption must be energetic. The increase in light intensity can be explained by a small area rising to a much higher temperature. Solar flares are looked at to help understand the phenomenon of stellar flares. Dwarfs that flare are observed to have strong magnetic fields. Those dwarf without the strong magnetic field do not seem to flare. It is believed that these regions of strong magnetic fields are associated with star spots. Theories on the energy that power the flares are given. Astrophysicists theorize that the driving force of a stellar flare is the detachment and collapse of a loop of magnetic flux. The mass loss due to stellar flares is discussed. It is believed that stellar flares are a significant contributor to the mass of interstellar medium in the Milky Way

By Draconis Stars

Science.gov (United States)

Bopp, Bernard W.

An optical spectroscopic survey of dK-M stars has resulted in the discovery of several new H-alpha emission objects. Available optical data suggest these stars have a level of chromospheric activity midway between active BY Dra stars and quiet dM's. These "marginal" BY Dra stars are single objects that have rotation velocities slightly higher than that of quiet field stars but below that of active flare/BY Dra objects. The marginal BY Dra stars provide us with a class of objects rotating very near a "trigger velocity" (believed to be 5 km/s) which appears to divide active flare/BY Dra stars from quiet dM's. UV data on Mg II emission fluxes and strength of transition region features such as C IV will serve to fix activity levels in the marginal objects and determine chromosphere and transition-region heating rates. Simultaneous optical magnetic field measures will be used to explore the connection between fieldstrength/filling-factor and atmospheric heating. Comparison of these data with published information on active and quiet dM stars will yield information on the character of the stellar dynamo as it makes a transition from "low" to "high" activity.

A systematic review of parenting interventions for traumatic brain injury: child and parent outcomes.

Science.gov (United States)

Brown, Felicity Louise; Whittingham, Koa; Boyd, Roslyn; Sofronoff, Kate

2013-01-01

To evaluate the efficacy of parenting interventions on child and parent behavioral and emotional outcomes for parents of children with traumatic brain injury (TBI). Systematic searches of 5 databases. Included studies were assessed for quality, and relevant data were extracted and collated. Eight articles met inclusion criteria, reporting 6 trials of interventions involving parent training for parents of children with TBI. Only 1 pre-post study trialed a version of a traditional parenting intervention. The remaining studies involved a multicomponent family problem-solving intervention. Each trial found a statistically significant intervention effect for at least 1 outcome measure. Interventions that train parents may be a useful approach to alleviate behavioral and emotional disturbances after pediatric TBI. Some evidence suggests that these interventions may help to improve parenting skill and adjustment. However, all identified studies included interventions with multiple treatment components, so the effects attributable to parent training alone remain undetermined. Further quality trials are needed to assess the unique effectiveness of parenting interventions in this population.

Shooting stars

International Nuclear Information System (INIS)

Maurette, M.; Hammer, C.

1985-01-01

A shooting star passage -even a star shower- can be sometimes easily seen during moonless black night. They represent the partial volatilization in earth atmosphere of meteorites or micrometeorites reduced in cosmic dusts. Everywhere on earth, these star dusts are searched to be gathered. This research made one year ago on the Greenland ice-cap is this article object; orbit gathering projects are also presented [fr

The Vixen Star Book user guide how to use the star book ten and the original star book

CERN Document Server

Chen, James

2016-01-01

This book is for anyone who owns, or is thinking of owning, a Vixen Star Book Ten telescope mount or its predecessor. A revolution in amateur astronomy has occurred in the past decade with the wide availability of high tech, computer-driven, Go-To telescopes. Vixen Optics is leading the way by offering the Star Book Ten system, with its unique star map graphics software. The Star Book Ten is the latest version of computer telescope control using star map graphics as a user interface, first introduced in the original Star Book first offered in 2003. The increasingly complicated nature of this software means that learning to optimize this program is not straightforward, and yet the resulting views when all features are correctly deployed can be phenomenal. After a short history of computerized Go-To telescopes for the consumer amateur astronomer market, Chen offers a treasury of technical information. His advice, tips, and solutions aid the user in getting the most out of the Star Book Ten system in observing s...

Suppression of the water ice and snow albedo feedback on planets orbiting red dwarf stars and the subsequent widening of the habitable zone.

Science.gov (United States)

Joshi, Manoj M; Haberle, Robert M

2012-01-01

M stars comprise 80% of main sequence stars, so their planetary systems provide the best chance for finding habitable planets, that is, those with surface liquid water. We have modeled the broadband albedo or reflectivity of water ice and snow for simulated planetary surfaces orbiting two observed red dwarf stars (or M stars), using spectrally resolved data of Earth's cryosphere. The gradual reduction of the albedos of snow and ice at wavelengths greater than 1 μm, combined with M stars emitting a significant fraction of their radiation at these same longer wavelengths, means that the albedos of ice and snow on planets orbiting M stars are much lower than their values on Earth. Our results imply that the ice/snow albedo climate feedback is significantly weaker for planets orbiting M stars than for planets orbiting G-type stars such as the Sun. In addition, planets with significant ice and snow cover will have significantly higher surface temperatures for a given stellar flux if the spectral variation of cryospheric albedo is considered, which in turn implies that the outer edge of the habitable zone around M stars may be 10-30% farther away from the parent star than previously thought.

STAR-TO-STAR IRON ABUNDANCE VARIATIONS IN RED GIANT BRANCH STARS IN THE GALACTIC GLOBULAR CLUSTER NGC 3201

International Nuclear Information System (INIS)

Simmerer, Jennifer; Ivans, Inese I.; Filler, Dan; Francois, Patrick; Charbonnel, Corinne; Monier, Richard; James, Gaël

2013-01-01

We present the metallicity as traced by the abundance of iron in the retrograde globular cluster NGC 3201, measured from high-resolution, high signal-to-noise spectra of 24 red giant branch stars. A spectroscopic analysis reveals a spread in [Fe/H] in the cluster stars at least as large as 0.4 dex. Star-to-star metallicity variations are supported both through photometry and through a detailed examination of spectra. We find no correlation between iron abundance and distance from the cluster core, as might be inferred from recent photometric studies. NGC 3201 is the lowest mass halo cluster to date to contain stars with significantly different [Fe/H] values.

Star-to-star Iron Abundance Variations in Red Giant Branch Stars in the Galactic Globular Cluster NGC 3201

Science.gov (United States)

Simmerer, Jennifer; Ivans, Inese I.; Filler, Dan; Francois, Patrick; Charbonnel, Corinne; Monier, Richard; James, Gaël

2013-02-01

We present the metallicity as traced by the abundance of iron in the retrograde globular cluster NGC 3201, measured from high-resolution, high signal-to-noise spectra of 24 red giant branch stars. A spectroscopic analysis reveals a spread in [Fe/H] in the cluster stars at least as large as 0.4 dex. Star-to-star metallicity variations are supported both through photometry and through a detailed examination of spectra. We find no correlation between iron abundance and distance from the cluster core, as might be inferred from recent photometric studies. NGC 3201 is the lowest mass halo cluster to date to contain stars with significantly different [Fe/H] values.

The first stars: CEMP-no stars and signatures of spinstars

Science.gov (United States)

Maeder, André; Meynet, Georges; Chiappini, Cristina

2015-04-01

Aims: The CEMP-no stars are "carbon-enhanced-metal-poor" stars that in principle show no evidence of s- and r-elements from neutron captures. We try to understand the origin and nucleosynthetic site of their peculiar CNO, Ne-Na, and Mg-Al abundances. Methods: We compare the observed abundances to the nucleosynthetic predictions of AGB models and of models of rotating massive stars with internal mixing and mass loss. We also analyze the different behaviors of α- and CNO-elements, as well the abundances of elements involved in the Ne-Na and Mg-Al cycles. Results: We show that CEMP-no stars exhibit products of He-burning that have gone through partial mixing and processing by the CNO cycle, producing low 12C/13C and a broad variety of [C/N] and [O/N] ratios. From a 12C/13C vs. [C/N] diagram, we conclude that neither the yields of AGB stars (in binaries or not) nor the yields of classic supernovae can fully account for the observed CNO abundances in CEMP-no stars. Better agreement is obtained once the chemical contribution by stellar winds of fast-rotating massive stars is taken into account, where partial mixing takes place, leading to various amounts of CNO being ejected. The [(C+N+O)/H] ratios of CEMP-no stars vary linearly with [Fe/H] above [Fe/H] = -4.0 indicating primary behavior by (C+N+O). Below [Fe/H] = -4.0, [(C+N+O)/H] is almost constant as a function of [Fe/H], implying very high [(C+N+O)/Fe] ratios up to 4 dex. In view of the timescales, such abundance ratios reflect more individual nucleosynthetic properties, rather than an average chemical evolution. The high [(C+N+O)/Fe] ratios (as well as the high [(C+N+O)/α-elements]) imply that stellar winds from partially mixed stars were the main source of these excesses of heavy elements now observed in CEMP-no stars. The ranges covered by the variations of [Na/Fe], [Mg/Fe], and [Al/Fe] are much broader than for the α-elements (with an atomic mass number above 24) and are comparable to the wide ranges covered

Variable Stars in the Field of V729 Aql

Science.gov (United States)

Cagaš, P.

2017-04-01

Wide field instruments can be used to acquire light curves of tens or even hundreds of variable stars per night, which increases the probability of new discoveries of interesting variable stars and generally increases the efficiency of observations. At the same time, wide field instruments produce a large amount of data, which must be processed using advanced software. The traditional approach, typically used by amateur astronomers, requires an unacceptable amount of time needed to process each data set. New functionality, built into SIPS software package, can shorten the time needed to obtain light curves by several orders of magnitude. Also, newly introduced SILICUPS software is intended for post-processing of stored light curves. It can be used to visualize observations from many nights, to find variable star periods, evaluate types of variability, etc. This work provides an overview of tools used to process data from the large field of view around the variable star V729 Aql. and demonstrates the results.

Star Cluster Structure from Hierarchical Star Formation

Science.gov (United States)

Grudic, Michael; Hopkins, Philip; Murray, Norman; Lamberts, Astrid; Guszejnov, David; Schmitz, Denise; Boylan-Kolchin, Michael

2018-01-01

Young massive star clusters (YMCs) spanning 104-108 M⊙ in mass generally have similar radial surface density profiles, with an outer power-law index typically between -2 and -3. This similarity suggests that they are shaped by scale-free physics at formation. Recent multi-physics MHD simulations of YMC formation have also produced populations of YMCs with this type of surface density profile, allowing us to narrow down the physics necessary to form a YMC with properties as observed. We show that the shallow density profiles of YMCs are a natural result of phase-space mixing that occurs as they assemble from the clumpy, hierarchically-clustered configuration imprinted by the star formation process. We develop physical intuition for this process via analytic arguments and collisionless N-body experiments, elucidating the connection between star formation physics and star cluster structure. This has implications for the early-time structure and evolution of proto-globular clusters, and prospects for simulating their formation in the FIRE cosmological zoom-in simulations.

Parenting a Child with a Learning Disability: A Qualitative Approach

Science.gov (United States)

Fernández-Alcántara, Manuel; Correa-Delgado, Cayetana; Muñoz, Ángela; Salvatierra, María Teresa; Fuentes-Hélices, Tadeo; Laynez-Rubio, Carolina

2017-01-01

The present study describes experiences associated with parenting children diagnosed with learning disabilities. Parents whose children were diagnosed with Attention Deficit Hyperactivity Disorder, dyslexia/language problems, and Asperger syndrome, related to poor performance at school, took part in the study. A qualitative study design was…

Atmospheric parameters and metallicities for 2191 stars in the globular cluster M4

International Nuclear Information System (INIS)

Malavolta, Luca; Piotto, Giampaolo; Nascimbeni, Valerio; Sneden, Christopher; Milone, Antonino P.; Bedin, Luigi R.

2014-01-01

We report new metallicities for stars of Galactic globular cluster M4 using the largest number of stars ever observed at high spectral resolution in any cluster. We analyzed 7250 spectra for 2771 cluster stars gathered with the Very Large Telescope (VLT) FLAMES+GIRAFFE spectrograph at VLT. These medium-resolution spectra cover a small wavelength range, and often have very low signal-to-noise ratios. We approached this data set by reconsidering the whole method of abundance analysis of large stellar samples from beginning to end. We developed a new algorithm that automatically determines the atmospheric parameters of a star. Nearly all of the data preparation steps for spectroscopic analyses are processed on the syntheses, not the observed spectra. For 322 red giant branch (RGB) stars with V ≤ 14.7, we obtain a nearly constant metallicity, ([Fe/H]) = –1.07 (σ = 0.02). No difference in the metallicity at the level of 0.01 dex is observed between the two RGB sequences identified by Monelli et al. For 1869 subgiant and main-sequence stars with V > 14.7, we obtain ([Fe/H]) = –1.16 (σ = 0.09) after fixing the microturbulent velocity. These values are consistent with previous studies that have performed detailed analyses of brighter RGB stars at higher spectroscopic resolution and wavelength coverage. It is not clear if the small mean metallicity difference between brighter and fainter M4 members is real or is the result of the low signal-to-noise characteristics of the fainter stars. The strength of our approach is shown by recovering a metallicity close to a single value for more than 2000 stars, using a data set that is non-optimal for atmospheric analyses. This technique is particularly suitable for noisy data taken in difficult observing conditions

Atmospheric parameters and metallicities for 2191 stars in the globular cluster M4

Energy Technology Data Exchange (ETDEWEB)

Malavolta, Luca; Piotto, Giampaolo; Nascimbeni, Valerio [Dipartimento di Fisica e Astronomia, Vicolo dell' Osservatorio 3, I-35122 Padova (Italy); Sneden, Christopher [Department of Astronomy and McDonald Observatory, The University of Texas, Austin, TX 78712 (United States); Milone, Antonino P. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT 2611 (Australia); Bedin, Luigi R., E-mail: luca.malavolta@unipd.it, E-mail: giampaolo.piotto@unipd.it, E-mail: valerio.nascimbeni@unipd.it, E-mail: luigi.bedin@oapd.inaf.it, E-mail: chris@verdi.as.utexas.edu, E-mail: milone@mso.anu.edu.au [INAF-Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy)

2014-02-01

We report new metallicities for stars of Galactic globular cluster M4 using the largest number of stars ever observed at high spectral resolution in any cluster. We analyzed 7250 spectra for 2771 cluster stars gathered with the Very Large Telescope (VLT) FLAMES+GIRAFFE spectrograph at VLT. These medium-resolution spectra cover a small wavelength range, and often have very low signal-to-noise ratios. We approached this data set by reconsidering the whole method of abundance analysis of large stellar samples from beginning to end. We developed a new algorithm that automatically determines the atmospheric parameters of a star. Nearly all of the data preparation steps for spectroscopic analyses are processed on the syntheses, not the observed spectra. For 322 red giant branch (RGB) stars with V ≤ 14.7, we obtain a nearly constant metallicity, ([Fe/H]) = –1.07 (σ = 0.02). No difference in the metallicity at the level of 0.01 dex is observed between the two RGB sequences identified by Monelli et al. For 1869 subgiant and main-sequence stars with V > 14.7, we obtain ([Fe/H]) = –1.16 (σ = 0.09) after fixing the microturbulent velocity. These values are consistent with previous studies that have performed detailed analyses of brighter RGB stars at higher spectroscopic resolution and wavelength coverage. It is not clear if the small mean metallicity difference between brighter and fainter M4 members is real or is the result of the low signal-to-noise characteristics of the fainter stars. The strength of our approach is shown by recovering a metallicity close to a single value for more than 2000 stars, using a data set that is non-optimal for atmospheric analyses. This technique is particularly suitable for noisy data taken in difficult observing conditions.

Communicating with children and parents: recommendations for a child-parent-centred approach for paediatric dentistry.

Science.gov (United States)

Freeman, R

2008-02-01

The European Academy of Paediatric Dentistry has called for a series of evidence-based statements to inform their guidelines on the behavioural management of the child patient. Communication between dentist, parent and child based upon scientifically robust research evidence was felt to be central to this request in order to provide empathetic and child-centred care for children and their parents attending for dental health care. Shekelle and colleagues [1999] devised a series of steps to develop an evidence-based clinical guideline. This framework allows first, the identification and refinement of the subject area and secondly, the identification and assessment of the evidence-base. Four areas of communication were identified as being of central importance. These were identification of the mother-child dyad; affective communication skills; problem solving and negotiation skills. It was recommended that paediatric dentists should become knowledgeable and competent in these skills in order to provide patient-centred care for the children and parents attending their clinics for dental treatment.

Molecular diagnostics of Galactic star-formation regions

Science.gov (United States)

Loenen, Edo; Baan, Willem; Spaans, Marco

2007-10-01

We propose a sensitive spectral survey of Galactic star-formation regions. Using the broadband correlator at two different frequencies, we expect to detect the (1-0) transition of CO, CN, HNC, HCN, HCO+, and HCO and various of their isotopes lines, as well as the (12-11) and (10-9) transitions of HC3N. The purpose of these observations is to create a consistent (public) database of molecular emission from galactic star-formation regions. The data will be interpreted using extensive physical and chemical modeling of the whole ensemble of lines, in order to get an accurate description of the molecular environment of these regions. In particular, this diagnostic approach will describe the optical depths, the densities, and the radiation fields in the medium and will allow the establishment of dominant temperature gradients. These observations are part of a program to study molecular emission on all scales, going from individual Galactic star-formation regions, through resolved nearby galaxies, to unresolved extra-galactic emission.

Interstellar clouds and the formation of stars

International Nuclear Information System (INIS)

Alfen, H.; Carlqvist, P.

1977-12-01

The 'pseudo-plasma formalism' which up to now has almost completely dominated theoretical astrophysics must be replaced by an experimentally based approach, involving the introduction of a number of neglected plasma phenomena, such as electric double layers, critical velocity, and pinch effect. The general belief that star light is the main ionizer is shown to be doubtful; hydromagnetic conversion of gravitational and kinetic energy may often be much more important. The revised plasma physics is applied to dark clouds and star formation. Magnetic fields do not necessarily counteract the contraction of a cloud, they may just as well 'pinch' the cloud. Magnetic compression may be the main mechanism for forming interstellar clouds and keeping them together. Star formation is due to an instability, but it is very unlikely that it has anything to do with the Jeans instablility. A reasonable mechanism is that the sedimentation of 'dust' (including solid bodies of different size) is triggering off a gravitationally assisted accretion. The study of the evolution of a dark cloud leads to a scenario of planet formation which is reconcilable with the results obtained from studies based on solar system data. This means that the new approach to cosmical plasma physics discussed logically leads to a consistent picture of the evolution of dark clouds and the formation of solar systems

Testing specificity among parents' depressive symptoms, parenting, and child internalizing and externalizing symptoms.

Science.gov (United States)

Gruhn, Meredith A; Dunbar, Jennifer P; Watson, Kelly H; Reising, Michelle M; McKee, Laura; Forehand, Rex; Cole, David A; Compas, Bruce E

2016-04-01

The present study examined the specificity in relations between observed withdrawn and intrusive parenting behaviors and children's internalizing and externalizing symptoms in an at-risk sample of children (ages 9 to 15 years old) of parents with a history of depression (N = 180). Given past findings that parental depression and parenting behaviors may differentially impact boys and girls, gender was examined as a moderator of the relations between these factors and child adjustment. Correlation and linear regression analyses showed that parental depressive symptoms were significantly related to withdrawn parenting for parents of boys and girls and to intrusive parenting for parents of boys only. When controlling for intrusive parenting, preliminary analyses demonstrated that parental depressive symptoms were significantly related to withdrawn parenting for parents of boys, and this association approached significance for parents of girls. Specificity analyses yielded that, when controlling for the other type of problem (i.e., internalizing or externalizing), withdrawn parenting specifically predicted externalizing problems but not internalizing problems in girls. No evidence of specificity was found for boys in this sample, suggesting that impaired parenting behaviors are diffusely related to both internalizing and externalizing symptoms for boys. Overall, results highlight the importance of accounting for child gender and suggest that targeting improvement in parenting behaviors and the reduction of depressive symptoms in interventions with parents with a history of depression may have potential to reduce internalizing and externalizing problems in this high-risk population. (c) 2016 APA, all rights reserved).

Expansion in higher harmonics of boson stars using a generalized Ruffini-Bonazzola approach. Part 1. Bound states

Energy Technology Data Exchange (ETDEWEB)

Eby, Joshua; Suranyi, Peter; Wijewardhana, L. C. R.

2018-04-01

The method pioneered by Ruffini and Bonazzola (RB) to describe boson stars involves an expansion of the boson field which is linear in creation and annihilation operators. This expansion constitutes an exact solution to a non-interacting field theory, and has been used as a reasonable ansatz for an interacting one. In this work, we show how one can go beyond the RB ansatz towards an exact solution of the interacting operator Klein-Gordon equation, which can be solved iteratively to ever higher precision. Our Generalized Ruffini-Bonazzola approach takes into account contributions from nontrivial harmonic dependence of the wavefunction, using a sum of terms with energy $k\\,E_0$, where $k\\geq1$ and $E_0$ is the chemical potential of a single bound axion. The method critically depends on an expansion in a parameter $\\Delta \\equiv \\sqrt{1-E_0{}^2/m^2}<1$, where $m$ is the mass of the boson. In the case of the axion potential, we calculate corrections which are relevant for axion stars in the transition or dense branches. We find with high precision the local minimum of the mass, $M_{min}\\approx 463\\,f^2/m$, at $\\Delta\\approx0.27$, where $f$ is the axion decay constant. This point marks the crossover from transition to dense branches of solutions, and a corresponding crossover from structural instability to stability.

Family systems approach to attachment relations, war trauma, and mental health among Palestinian children and parents

Science.gov (United States)

Punamäki, Raija-Leena; Qouta, Samir R.; Peltonen, Kirsi

2017-01-01

ABSTRACT Background: Trauma affects the family unit as a whole; however, most existing research uses individual or, at most, dyadic approaches to analyse families with histories of trauma. Objective: This study aims to identify potentially distinct family types according to attachment, parenting, and sibling relations, to analyse how these family types differ with respect to war trauma, and to explore how children’s mental health and cognitive processing differ across these family types. Method: Participants included Palestinian mothers and fathers (N = 325) and their children (one per family; 49.4% girls; 10–13 years old; mean ± SD age = 11.35 ± 0.57 years) after the Gaza War of 2008–2009. Both parents reported their exposure to war trauma, secure attachment availability, and parenting practices, as well as the target child’s internalizing and externalizing symptoms [Strengths and Difficulties Questionnaire (SDQ)]. Children reported their symptoms of post-traumatic stress disorder (on the Children’s Revised Impact Event Scale), depression (Birleson), and SDQ, as well as their post-traumatic cognitions (Children’s Post Traumatic Cognitions Inventory). Results: A cluster analysis identified four family types. The largest type reflected secure attachment and optimal relationships (security and positive family relationships, 36.2%, n = 102), and the smallest exhibited insecurity and problematic relationships (insecurity and negative family relationships, 15.6%; n = 44). Further, families with discrepant experiences (23.0%; n = 65) and moderate security and neutral relationships (25.2%; n = 71) emerged. The insecurity and negative relationships family type showed higher levels of war trauma; internalizing, externalizing, and depressive symptoms among children; and dysfunctional post-traumatic cognitions than other family types. Conclusion: The family systems approach to mental health is warranted in war conditions, and therapeutic

Family systems approach to attachment relations, war trauma, and mental health among Palestinian children and parents.

Science.gov (United States)

Punamäki, Raija-Leena; Qouta, Samir R; Peltonen, Kirsi

2017-01-01

Background : Trauma affects the family unit as a whole; however, most existing research uses individual or, at most, dyadic approaches to analyse families with histories of trauma. Objective : This study aims to identify potentially distinct family types according to attachment, parenting, and sibling relations, to analyse how these family types differ with respect to war trauma, and to explore how children's mental health and cognitive processing differ across these family types. Method: Participants included Palestinian mothers and fathers ( N  = 325) and their children (one per family; 49.4% girls; 10-13 years old; mean ±  SD age = 11.35 ± 0.57 years) after the Gaza War of 2008-2009. Both parents reported their exposure to war trauma, secure attachment availability, and parenting practices, as well as the target child's internalizing and externalizing symptoms [Strengths and Difficulties Questionnaire (SDQ)]. Children reported their symptoms of post-traumatic stress disorder (on the Children's Revised Impact Event Scale), depression (Birleson), and SDQ, as well as their post-traumatic cognitions (Children's Post Traumatic Cognitions Inventory). Results: A cluster analysis identified four family types. The largest type reflected secure attachment and optimal relationships (security and positive family relationships, 36.2%, n  = 102), and the smallest exhibited insecurity and problematic relationships (insecurity and negative family relationships, 15.6%; n  = 44). Further, families with discrepant experiences (23.0%; n  = 65) and moderate security and neutral relationships (25.2%; n  = 71) emerged. The insecurity and negative relationships family type showed higher levels of war trauma; internalizing, externalizing, and depressive symptoms among children; and dysfunctional post-traumatic cognitions than other family types. Conclusion: The family systems approach to mental health is warranted in war conditions, and therapeutic interventions for

Two Approaches to Estimating the Effect of Parenting on the Development of Executive Function in Early Childhood

Science.gov (United States)

Blair, Clancy; Raver, C. Cybele; Berry, Daniel J.

2014-01-01

In the current article, we contrast 2 analytical approaches to estimate the relation of parenting to executive function development in a sample of 1,292 children assessed longitudinally between the ages of 36 and 60 months of age. Children were administered a newly developed and validated battery of 6 executive function tasks tapping inhibitory…

COLLABORATIVE PARENT COUNSELING in MUSIC THERAPY (CPCiMT) FOR PARENTS OF CHILDRN WITH AUTISM SPECTRUM DISORDER

DEFF Research Database (Denmark)

Gottfried, Tali

Abstract Collaborative Parent Counseling in Music Therapy (PCiMT) for parents of children with Autism Spectrum Disorder is a clinical approach, in which the music therapist conducts both the individual MT sessions for the child as well as the counseling sessions for the parents. This practice...... is now being tested in my PhD research. Description Early parent-child relationship, represented commonly by reciprocal musical-wise interaction (Stern, 1985), is interrupted by organic impairments, sourced at the core of the Autism Spectrum Disorder (ASD). Parenting a child with ASD involves great...

Energy production in stars

International Nuclear Information System (INIS)

Bethe, Hans.

1977-01-01

Energy in stars is released partly by gravitation, partly by nuclear reactions. For ordinary stars like our sun, nuclear reactions predominate. However, at the end of the life of a star very large amounts of energy are released by gravitational collapse; this can amount to as much as 10 times the total energy released nuclear reactions. The rotational energy of pulsars is a small remnant of the energy of gravitation. The end stage of small stars is generally a white dwarf, of heavy stars a neutron star of possibly a black hole

Stars and Flowers, Flowers and Stars

Science.gov (United States)

Minti, Hari

2012-12-01

The author, a graduated from the Bucharest University (1964), actually living and working in Israel, concerns his book to variable stars and flowers, two domains of his interest. The analogies includes double stars, eclipsing double stars, eclipses, Big Bang. The book contains 34 chapters, each of which concerns various relations between astronomy and other sciences and pseudosciences such as Psychology, Religion, Geology, Computers and Astrology (to which the author is not an adherent). A special part of the book is dedicated to archeoastronomy and ethnoastronomy, as well as to history of astronomy. Between the main points of interest of these parts: ancient sanctuaries in Sarmizegetusa (Dacia), Stone Henge(UK) and other. The last chapter of the book is dedicated to flowers. The book is richly illustrated. It is designed for a wide circle of readers.

Expelled grains from an unseen parent body around AU Microscopii

Science.gov (United States)

Sezestre, É.; Augereau, J.-C.; Boccaletti, A.; Thébault, P.

2017-11-01

Context. Recent observations of the edge-on debris disk of AU Mic have revealed asymmetric, fast outward-moving arch-like structures above the disk midplane. Although asymmetries are frequent in debris disks, no model can readily explain the characteristics of these features. Aims: We present a model aiming to reproduce the dynamics of these structures, more specifically their high projected speeds and their apparent position. We test the hypothesis of dust emitted by a point source and then expelled from the system by the strong stellar wind of this young M-type star. In this model we make the assumption that the dust grains follow the same dynamics as the structures, I.e., they are not local density enhancements. Methods: We perform numerical simulations of test particle trajectories to explore the available parameter space, in particular the radial location R0 of the dust producing parent body and the size of the dust grains as parameterized by the value of β (ratio of stellar wind and radiation pressure forces over gravitation). We consider the cases of a static and of an orbiting parent body. Results: We find that for all considered scenarios (static or moving parent body), there is always a set of (R0,β) parameters able to fit the observed features. The common characteristics of these solutions is that they all require a high value of β, of around 6. This means that the star is probably very active, and the grains composing the structures are submicronic in order for observable grains to reach such high β values. We find that the location of the hypothetical parent body is closer in than the planetesimal belt, around 8 ± 2 au (orbiting case) or 28 ± 7 au (static case). A nearly periodic process of dust emission appears, of 2 yr in the orbiting scenarios and 7 yr in the static case. Conclusions: We show that the scenario of sequential dust releases by an unseen point-source parent body is able to explain the radial behavior of the observed structures. We

Ten colour photometry of twelve Ap-stars

International Nuclear Information System (INIS)

Musielok, B.; Lange, D.; Schoeneich, W.; Hildebrandt, G.; Zelwanowa, E.; Hempelmann, A.; Salmanov, G.

1980-01-01

Ten-colour photoelectric observations are presented for twelve Ap-stars. Improved ephemeris for seven of them is given. Phase relations between the light curves and line intensity variations are discussed. The problem of the electromagnetic flux conctancy of IOTA Cas is approached from a qualitative point of view. (author)

Deducing hybrid performance from parental metabolic profiles of young primary roots of maize by using a multivariate diallel approach.

Directory of Open Access Journals (Sweden)

Kristen Feher

Full Text Available Heterosis, the greater vigor of hybrids compared to their parents, has been exploited in maize breeding for more than 100 years to produce ever better performing elite hybrids of increased yield. Despite extensive research, the underlying mechanisms shaping the extent of heterosis are not well understood, rendering the process of selecting an optimal set of parental lines tedious. This study is based on a dataset consisting of 112 metabolite levels in young roots of four parental maize inbred lines and their corresponding twelve hybrids, along with the roots' biomass as a heterotic trait. Because the parental biomass is a poor predictor for hybrid biomass, we established a model framework to deduce the biomass of the hybrid from metabolite profiles of its parental lines. In the proposed framework, the hybrid metabolite levels are expressed relative to the parental levels by incorporating the standard concept of additivity/dominance, which we name the Combined Relative Level (CRL. Our modeling strategy includes a feature selection step on the parental levels which are demonstrated to be predictive of CRL across many hybrid metabolites. We demonstrate that these selected parental metabolites are further predictive of hybrid biomass. Our approach directly employs the diallel structure in a multivariate fashion, whereby we attempt to not only predict macroscopic phenotype (biomass, but also molecular phenotype (metabolite profiles. Therefore, our study provides the first steps for further investigations of the genetic determinants to metabolism and, ultimately, growth. Finally, our success on the small-scale experiments implies a valid strategy for large-scale experiments, where parental metabolite profiles may be used together with profiles of selected hybrids as a training set to predict biomass of all possible hybrids.

How bright planets became dim stars: planetary speculations in John Herschel's double star astronomy.

Science.gov (United States)

Case, Stephen

2014-03-01

Previous research on the origins of double star astronomy in the early nineteenth century emphasized the role mathematical methods and instrumentation played in motivating early observations of these objects. The work of the British astronomer John Herschel, however, shows that questions regarding the physical nature of double stars were also important. In particular, an analysis of John Herschel's early work on double stars illustrates the way in which speculations regarding these objects were shaped by assumptions of the properties of stars themselves. For Herschel, a major consideration in double star astronomy was distinguishing between types of double stars. Optical doubles were useful in determining parallax while binary doubles were not. In practice, classification of a specific double star pair into one of these categories was based on the assumption that stars were of approximately the same luminosity and thus differences in relative brightness between stars were caused by difference in distances. Such assumptions, though ultimately abandoned, would lead Herschel in the 1830s to advance the possibility that the dim companion stars in certain double star pairs were not stars at all but in fact planets. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spectrophotometry of peculiar B and A stars. II. Eleven mercury-manganese stars

International Nuclear Information System (INIS)

Adelman, S.J.; Pyper, D.M.

1979-01-01

Spectrophotometry of eleven HgMn stars is presented for the optical region. As found in Paper I, the HgMn stars have systematically larger Δiota* and Δa values than the normal main sequence stars due to differences with respect to the mean continuum particularly of the lambda4464 values and the lambda5200 region, respectively. The HgMn stars exhibit a continuous range in the behavior of both the lambda4200 and lambda5200 regions between those stars that have index values larger than the appropriate criterion of presence and present definite evidence for the features to those stars with only a slight possibility of such features. The strengths of the lambda4200 and lambda5200 features appear not to be correlated. In the HgMn stars, both features may be due to differential line blocking. In the energy distribution of all eleven stars, the Balmer jump regions best fit the predictions of slightly hotter solar composition, log g=4.0, fully line blanketed model atmospheres than do the corresponding Paschen continua

Mindfulness and parenting distress among parents of children with disabilities: A literature review.

Science.gov (United States)

Rayan, Ahmad; Ahmad, Muayyad

2018-04-01

The purpose of this review was to determine the effectiveness of mindfulness-based interventions (MBIs) for management of parenting distress in parents of children with disabilities. A narrative review was conducted. A search protocol was conducted using Google Scholar, EBSCO, Pubmed, CINAHL, Ovid, and PsycINFO databases up to September 1, 2016. Interventions used a variety of approaches to implement mindfulness training, including MBIs and combined mindfulness and other interventions. Targeted outcomes included in this review were parenting stress and psychological distress. Most of the reviewed papers reported positive role of MBIs to manage parenting distress. The results of this first review on the topic provide preliminary support for the efficacy of MBIs for supporting parents of children with disabilities. © 2017 Wiley Periodicals, Inc.

Discriminating strange star mergers from neutron star mergers by gravitational-wave measurements

International Nuclear Information System (INIS)

Bauswein, A.; Oechslin, R.; Janka, H.-T.

2010-01-01

We perform three-dimensional relativistic hydrodynamical simulations of the coalescence of strange stars and explore the possibility to decide on the strange matter hypothesis by means of gravitational-wave measurements. Self-binding of strange quark matter and the generally more compact stars yield features that clearly distinguish strange star from neutron star mergers, e.g. hampering tidal disruption during the plunge of quark stars. Furthermore, instead of forming dilute halo structures around the remnant as in the case of neutron star mergers, the coalescence of strange stars results in a differentially rotating hypermassive object with a sharp surface layer surrounded by a geometrically thin, clumpy high-density strange quark matter disk. We also investigate the importance of including nonzero temperature equations of state in neutron star and strange star merger simulations. In both cases we find a crucial sensitivity of the dynamics and outcome of the coalescence to thermal effects, e.g. the outer remnant structure and the delay time of the dense remnant core to black hole collapse depend on the inclusion of nonzero temperature effects. For comparing and classifying the gravitational-wave signals, we use a number of characteristic quantities like the maximum frequency during inspiral or the dominant frequency of oscillations of the postmerger remnant. In general, these frequencies are higher for strange star mergers. Only for particular choices of the equation of state the frequencies of neutron star and strange star mergers are similar. In such cases additional features of the gravitational-wave luminosity spectrum like the ratio of energy emitted during the inspiral phase to the energy radiated away in the postmerger stage may help to discriminate coalescence events of the different types. If such characteristic quantities could be extracted from gravitational-wave signals, for instance with the upcoming gravitational-wave detectors, a decision on the

Time-dependent Models of Magnetospheric Accretion onto Young Stars

Energy Technology Data Exchange (ETDEWEB)

Robinson, C. E.; Espaillat, C. C. [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Owen, J. E. [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States); Adams, F. C., E-mail: connorr@bu.edu [Physics Department, University of Michigan, Ann Arbor, MI 48109 (United States)

2017-04-01

Accretion onto Classical T Tauri stars is thought to take place through the action of magnetospheric processes, with gas in the inner disk being channeled onto the star’s surface by the stellar magnetic field lines. Young stars are known to accrete material in a time-variable manner, and the source of this variability remains an open problem, particularly on the shortest (∼day) timescales. Using one-dimensional time-dependent numerical simulations that follow the field line geometry, we find that for plausibly realistic young stars, steady-state transonic accretion occurs naturally in the absence of any other source of variability. However, we show that if the density in the inner disk varies smoothly in time with ∼day-long timescales (e.g., due to turbulence), this complication can lead to the development of shocks in the accretion column. These shocks propagate along the accretion column and ultimately hit the star, leading to rapid, large amplitude changes in the accretion rate. We argue that when these shocks hit the star, the observed time dependence will be a rapid increase in accretion luminosity, followed by a slower decline, and could be an explanation for some of the short-period variability observed in accreting young stars. Our one-dimensional approach bridges previous analytic work to more complicated multi-dimensional simulations and observations.

Time-dependent Models of Magnetospheric Accretion onto Young Stars

International Nuclear Information System (INIS)

Robinson, C. E.; Espaillat, C. C.; Owen, J. E.; Adams, F. C.

2017-01-01

Accretion onto Classical T Tauri stars is thought to take place through the action of magnetospheric processes, with gas in the inner disk being channeled onto the star’s surface by the stellar magnetic field lines. Young stars are known to accrete material in a time-variable manner, and the source of this variability remains an open problem, particularly on the shortest (∼day) timescales. Using one-dimensional time-dependent numerical simulations that follow the field line geometry, we find that for plausibly realistic young stars, steady-state transonic accretion occurs naturally in the absence of any other source of variability. However, we show that if the density in the inner disk varies smoothly in time with ∼day-long timescales (e.g., due to turbulence), this complication can lead to the development of shocks in the accretion column. These shocks propagate along the accretion column and ultimately hit the star, leading to rapid, large amplitude changes in the accretion rate. We argue that when these shocks hit the star, the observed time dependence will be a rapid increase in accretion luminosity, followed by a slower decline, and could be an explanation for some of the short-period variability observed in accreting young stars. Our one-dimensional approach bridges previous analytic work to more complicated multi-dimensional simulations and observations.

Child Physical Punishment, Parenting, and School Readiness

Science.gov (United States)

Weegar, Kelly; Guérin-Marion, Camille; Fréchette, Sabrina; Romano, Elisa

2018-01-01

This study explored how physical punishment (PP) and other parenting approaches may predict school readiness outcomes. By using the Canada-wide representative data, 5,513 children were followed over a 2-year period. Caregivers reported on their use of PP and other parenting approaches (i.e., literacy and learning activities and other disciplinary…

Oscillations in neutron stars

Energy Technology Data Exchange (ETDEWEB)

Hoeye, Gudrun Kristine

1999-07-01

We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l (>{sub )} 4) f-modes we were also able to derive a formula that determines II{sub l+1} from II{sub l} and II{sub l-1} to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n{sub c}, while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

Oscillations in neutron stars

International Nuclear Information System (INIS)

Hoeye, Gudrun Kristine

1999-01-01

We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l → 4) f-modes we were also able to derive a formula that determines II l+1 from II l and II l-1 to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n c , while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

X-ray sources in regions of star formation. I. The naked T Tauri stars

International Nuclear Information System (INIS)

Walter, F.M.

1986-01-01

Einstein X-ray observations of regions of active star formation in Taurus, Ophiuchus, and Corona Australis show a greatly enhanced surface density of stellar X-ray sources over that seen in other parts of the sky. Many of the X-ray sources are identified with low-mass, pre-main-sequence stars which are not classical T Tauri stars. The X-ray, photometric, and spectroscopic data for these stars are discussed. Seven early K stars in Oph and CrA are likely to be 1-solar-mass post-T Tauri stars with ages of 10-million yr. The late K stars in Taurus are not post-T Tauri, but naked T Tauri stars, which are coeval with the T Tauri stars, differing mainly in the lack of a circumstellar envelope. 72 references

The incidence of stellar mergers and mass gainers among massive stars

International Nuclear Information System (INIS)

De Mink, S. E.; Sana, H.; Langer, N.; Izzard, R. G.; Schneider, F. R. N.

2014-01-01

Because the majority of massive stars are born as members of close binary systems, populations of massive main-sequence stars contain stellar mergers and products of binary mass transfer. We simulate populations of massive stars accounting for all major binary evolution effects based on the most recent binary parameter statistics and extensively evaluate the effect of model uncertainties. Assuming constant star formation, we find that 8 −4 +9 % of a sample of early-type stars are the products of a merger resulting from a close binary system. In total we find that 30 −15 +10 % of massive main-sequence stars are the products of binary interaction. We show that the commonly adopted approach to minimize the effects of binaries on an observed sample by excluding systems detected as binaries through radial velocity campaigns can be counterproductive. Systems with significant radial velocity variations are mostly pre-interaction systems. Excluding them substantially enhances the relative incidence of mergers and binary products in the non-radial velocity variable sample. This poses a challenge for testing single stellar evolutionary models. It also raises the question of whether certain peculiar classes of stars, such as magnetic O stars, are the result of binary interaction and it emphasizes the need to further study the effect of binarity on the diagnostics that are used to derive the fundamental properties (star-formation history, initial mass function, mass-to-light ratio) of stellar populations nearby and at high redshift.

Wave Star

DEFF Research Database (Denmark)

Kramer, Morten; Brorsen, Michael; Frigaard, Peter

Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star.......Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star....

Arp 202: a TDG formed in a parent's extended dark matter halo?

Science.gov (United States)

Scott, T. C.; Lagos, P.; Ramya, S.; Sengupta, C.; Paudel, S.; Sahu, D. K.; Misra, K.; Woo, J.-H.; Sohn, B. W.

2018-03-01

We report on H α + [N II] imaging of the Arp 202 interacting pair and its tidal dwarf galaxy (TDG) candidate as well as a GMOS long slit spectrum from the TDG candidate, observed with the Gemini North telescope. Our H α + [N II] imaging reveals the TDG to have an elongated structure, ˜ 1.9 kpc in length with the two principal star-forming knots at either end. Our observations also show the TDG candidate has a recessional VH α ˜ 3032 km s-1, within 100 km s-1 of the parent pair's mean velocity and an oxygen abundance of 12+log(O/H) = 8.10±0.41. The TDG's oxygen abundance is in good agreement with that of a star-forming region in NGC 2719A, one of the parent galaxies, which has an estimated oxygen abundance of 12+log(O/H) = 8.05 ± 0.41. The TDG's VH α and oxygen abundance confirm previous results validating the candidate as a TDG. The absence of detectable emission from the TDG in Spitzer 3.6 and 4.5 μm images together with the lack of absorption lines and weak continuum in the spectrum is consistent with absence the of an old population (≳0.5 Gyr). The location of the TDG within the interaction debris and the absence of indicators of an old stellar population in the TDG is consistent with a scenario in which the TDG is formed from H I stripped from the parent galaxies and within the extended dark matter halo of one of the parents as proposed by Bournaud et al. and Duc et al.

Descendants of the first stars: the distinct chemical signature of second generation stars

Science.gov (United States)

Hartwig, Tilman; Yoshida, Naoki; Magg, Mattis; Frebel, Anna; Glover, Simon C. O.; Gómez, Facundo A.; Griffen, Brendan; Ishigaki, Miho N.; Ji, Alexander P.; Klessen, Ralf S.; O'Shea, Brian W.; Tominaga, Nozomu

2018-05-01

Extremely metal-poor (EMP) stars in the Milky Way (MW) allow us to infer the properties of their progenitors by comparing their chemical composition to the metal yields of the first supernovae. This method is most powerful when applied to mono-enriched stars, i.e. stars that formed from gas that was enriched by only one previous supernova. We present a novel diagnostic to identify this subclass of EMP stars. We model the first generations of star formation semi-analytically, based on dark matter halo merger trees that yield MW-like halos at the present day. Radiative and chemical feedback are included self-consistently and we trace all elements up to zinc. Mono-enriched stars account for only ˜1% of second generation stars in our fiducial model and we provide an analytical formula for this probability. We also present a novel analytical diagnostic to identify mono-enriched stars, based on the metal yields of the first supernovae. This new diagnostic allows us to derive our main results independently from the specific assumptions made regarding Pop III star formation, and we apply it to a set of observed EMP stars to demonstrate its strengths and limitations. Our results may provide selection criteria for current and future surveys and therefore contribute to a deeper understanding of EMP stars and their progenitors.

Intense electromagnetic outbursts from collapsing hypermassive neutron stars

Science.gov (United States)

Lehner, Luis; Palenzuela, Carlos; Liebling, Steven L.; Thompson, Christopher; Hanna, Chad

2012-11-01

We study the gravitational collapse of a magnetized neutron star using a novel numerical approach able to capture both the dynamics of the star and the behavior of the surrounding plasma. In this approach, a fully general relativistic magnetohydrodynamics implementation models the collapse of the star and provides appropriate boundary conditions to a force-free model which describes the stellar exterior. We validate this strategy by comparing with known results for the rotating monopole and aligned rotator solutions and then apply it to study both rotating and nonrotating stellar collapse scenarios and contrast the behavior with what is obtained when employing the electrovacuum approximation outside the star. The nonrotating electrovacuum collapse is shown to agree qualitatively with a Newtonian model of the electromagnetic field outside a collapsing star. We illustrate and discuss a fundamental difference between the force-free and electrovacuum solutions, involving the appearance of large zones of electric-dominated field in the vacuum case. This provides a clear demonstration of how dissipative singularities appear generically in the nonlinear time evolution of force-free fluids. In both the rotating and nonrotating cases, our simulations indicate that the collapse induces a strong electromagnetic transient, which leaves behind an uncharged, unmagnetized Kerr black hole. In the case of submillisecond rotation, the magnetic field experiences strong winding, and the transient carries much more energy. This result has important implications for models of gamma-ray bursts. Even when the neutron star is surrounded by an accretion torus (as in binary merger and collapsar scenarios), a magnetosphere may emerge through a dynamo process operating in a surface shear layer. When this rapidly rotating magnetar collapses to a black hole, the electromagnetic energy released can compete with the later output in a Blandford-Znajek jet. Much less electromagnetic energy is

Neutron star formation in theoretical supernovae. Low mass stars and white dwarfs

International Nuclear Information System (INIS)

Nomoto, K.

1986-01-01

The presupernova evolution of stars that form semi-degenerate or strongly degenerate O + Ne + Mg cores is discussed. For the 10 to 13 Msub solar stars, behavior of off-center neon flashes is crucial. The 8 to 10 m/sub solar stars do not ignite neon and eventually collapse due to electron captures. Properties of supernova explosions and neutron stars expected from these low mass progenitors are compared with the Crab nebula. The conditions for which neutron stars form from accretion-induced collapse of white dwarfs in clsoe binary systems is also examined

Book Review: "Inside Stars. A Theory of the Internal Constitution of Stars, and the Sources of Stellar Energy According to General Relativity" (Letters to Progress in Physics

Directory of Open Access Journals (Sweden)

Millette P. A.

2014-01-01

Full Text Available This book provides a general relativistic theory of the internal constitution of liquid stars. It is a solid contribution to our understanding of stellar structure from a general relativistic perspective. It raises new ideas on the constitution of stars and planetary systems, and proposes a new approach to stellar structure an d stellar energy generation which is bound to help us better understand stellar astrophysics.

Mental Retardation and Parenting Stress

Directory of Open Access Journals (Sweden)

Eleni Siamaga

2011-01-01

Full Text Available Backround: The presence, upbringing and looking after of a mentally retarded child in the family, can become a threat to the mental health of its parents and is the main predisposing factor of stress for the parents.Aim: The purpose of this systematic review is (a to document the contemporary research bibliography related to the stress of parents with mentally retarded children, (b to aggregate the factors and secondary parameters based on the contemporary research related to the influence of the (child’s mental retardation on the parents and (c to show an intercultural aspect regarding the presence of stress to parents with mentally retarded children.Methods: Systematic review of research articles published in scientific journals included in the international academic databases HEAL-LING, SAGE, ELSEVIER, WILSON, SCIENCEDIRECT, MEDLINE, PUBMED, PsycINFO, Cochrane, EMBASE, SCIRUS and CINAHL having as search criteria and key words the terms («parental stress and mental retardation» [MeSH], «parenting stress and persons with special needs» [MeSH], «mental retardation and family problems» [MeSH], «stress and parents» [MeSH], «parenting and stress» [MeSH], «mental delay and parents» [MeSH], «developmental disabilities and family stress» [MeSH], «intellectual handicap and parenting» [MeSH], «maternal stress and child with disabilities» [MeSH].Discussion: The review has proven that all forms of mental retardation have an important -from a statistic point of viewimpacton the parents’ mental health. Anxiety, stress and depression are common symptoms mentioned by the parents.Additionally, there are individual variables such as the husband-wife relationship, the parents’ approach to their child’s disability, the parental strategies used in order to cope with the daily life of the child’s disability and the behavioural problems of their child, all of which contribute to the increase of the level of parental stress

MK classification of evolved blue stars in the halo

International Nuclear Information System (INIS)

Garrison, R.F.

1987-01-01

The problem of the masses and origin of the evolved blue stars is very complex. No single approach can give all the answers unambiguously; it would be naive to suppose otherwise. The MK process and the MK system give a perspective which complements photometric, kinematic, high dispersion and other quantitative data. It is useful to know which stars are similar (or not) in spectral morphology, so that interesting candidates can be selected for further study. In many cases, the gross physical characteristics can be fairly well determined by use of the MK System. 8 references

Evolution of massive stars in very young clusters and associations

International Nuclear Information System (INIS)

Stothers, R.B.

1985-01-01

The stellar content of very young galactic clusters and associations with well-determined ages has been analyzed statistically to derive information about stellar evolution at high masses. The adopted approach is semiempirical and uses natural spectroscopic groups of stars on the H-R diagram, together with the stars' apparent magnitudes. Cluster distance moduli are not used. Only the most basic elements of stellar evolution theory are required as input. For stellar aggregates with main-sequence turnups at spectral types between O9 and B2, the following conclusions have emerged: (1) O-type main-sequence stars evolve to a spectral type of B1 during core hydrogen burning; (2) most of the O-type blue stragglers are newly formed massive stars, burning core hydrogen; (3) supergiants lying redward of the turnup, as well as most, or all, of the Wolf-Rayet stars, are burning core helium; (4) Wolf-Rayet stars originally had masses greater than 30--40 M/sub sun/, while known M-type supergiants evolved from star less massive than approx.30 M/sub sun/; (5) phases of evolution following core helium burning are unobservably rapid, presumably on account of copious neutrino emission; and (6) formation of stars of high mass continues vigorously in most young clusters and association for approx.8 x 10 6 yr. The important result concerning the evolutionary status of the supergiants depends only on the total number of these stars and not on how they are distributed between blue and red types; the result, however, may be sensitive to the assumed amount of convective core overshooting. Conclusions in the present work refer chiefly to luminous stars in the mass range 10--40 M/sub sun/, belonging to aggregates in the age range (6--25) x 10 6 yr

The Role of Parenting for the Adjustment of Children with and without Learning Disabilities: A Person-Oriented Approach

Science.gov (United States)

Barkauskiene, Rasa

2009-01-01

A person-oriented approach was used to examine the role of parenting in the associations between single learning disabilities and multiple learning disabilities and the adjustment difficulties in 8-11-year-olds. The results revealed that multiple, but not single, learning disabilities were associated with greater difficulties in emotional and…

General Relativity and Compact Stars

International Nuclear Information System (INIS)

Glendenning, Norman K.

2005-01-01

Compact stars--broadly grouped as neutron stars and white dwarfs--are the ashes of luminous stars. One or the other is the fate that awaits the cores of most stars after a lifetime of tens to thousands of millions of years. Whichever of these objects is formed at the end of the life of a particular luminous star, the compact object will live in many respects unchanged from the state in which it was formed. Neutron stars themselves can take several forms--hyperon, hybrid, or strange quark star. Likewise white dwarfs take different forms though only in the dominant nuclear species. A black hole is probably the fate of the most massive stars, an inaccessible region of spacetime into which the entire star, ashes and all, falls at the end of the luminous phase. Neutron stars are the smallest, densest stars known. Like all stars, neutron stars rotate--some as many as a few hundred times a second. A star rotating at such a rate will experience an enormous centrifugal force that must be balanced by gravity or else it will be ripped apart. The balance of the two forces informs us of the lower limit on the stellar density. Neutron stars are 10 14 times denser than Earth. Some neutron stars are in binary orbit with a companion. Application of orbital mechanics allows an assessment of masses in some cases. The mass of a neutron star is typically 1.5 solar masses. They can therefore infer their radii: about ten kilometers. Into such a small object, the entire mass of our sun and more, is compressed

Star formation

International Nuclear Information System (INIS)

Woodward, P.R.

1978-01-01

Theoretical models of star formation are discussed beginning with the earliest stages and ending in the formation of rotating, self-gravitating disks or rings. First a model of the implosion of very diffuse gas clouds is presented which relies upon a shock at the edge of a galactic spiral arm to drive the implosion. Second, models are presented for the formation of a second generation of massive stars in such a cloud once a first generation has formed. These models rely on the ionizing radiation from massive stars or on the supernova shocks produced when these stars explode. Finally, calculations of the gravitational collapse of rotating clouds are discussed with special focus on the question of whether rotating disks or rings are the result of such a collapse. 65 references

Dark stars: a new study of the first stars in the Universe

International Nuclear Information System (INIS)

Freese, Katherine; Bodenheimer, Peter; Gondolo, Paolo; Spolyar, Douglas

2009-01-01

We have proposed that the first phase of stellar evolution in the history of the Universe may be dark stars (DSs), powered by dark matter (DM) heating rather than by nuclear fusion. Weakly interacting massive particles, which may be their own antipartners, collect inside the first stars and annihilate to produce a heat source that can power the stars. A new stellar phase results, a DS, powered by DM annihilation as long as there is DM fuel, with lifetimes from millions to billions of years. We find that the first stars are very bright (∼10 6 L o-dot ) and cool (T surf surf > 50 000 K); hence DS should be observationally distinct from standard Pop III stars. Once the DM fuel is exhausted, the DS becomes a heavy main sequence star; these stars eventually collapse to form massive black holes that may provide seeds for supermassive black holes observed at early times as well as explanations for recent ARCADE data and for intermediate black holes.

Introduction to neutron stars

Energy Technology Data Exchange (ETDEWEB)

Lattimer, James M. [Dept. of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States)

2015-02-24

Neutron stars contain the densest form of matter in the present universe. General relativity and causality set important constraints to their compactness. In addition, analytic GR solutions are useful in understanding the relationships that exist among the maximum mass, radii, moments of inertia, and tidal Love numbers of neutron stars, all of which are accessible to observation. Some of these relations are independent of the underlying dense matter equation of state, while others are very sensitive to the equation of state. Recent observations of neutron stars from pulsar timing, quiescent X-ray emission from binaries, and Type I X-ray bursts can set important constraints on the structure of neutron stars and the underlying equation of state. In addition, measurements of thermal radiation from neutron stars has uncovered the possible existence of neutron and proton superfluidity/superconductivity in the core of a neutron star, as well as offering powerful evidence that typical neutron stars have significant crusts. These observations impose constraints on the existence of strange quark matter stars, and limit the possibility that abundant deconfined quark matter or hyperons exist in the cores of neutron stars.

Polarization of Be stars

International Nuclear Information System (INIS)

Johns, M.W.

1975-01-01

Linear polarization of starlight may be produced by electron scattering in the extended atmospheres of early type stars. Techniques are investigated for the measurement and interpretation of this polarization. Polarimetric observations were made of twelve visual double star systems in which at least one member was a B type star as a means of separating the intrinsic stellar polarization from the polarization produced in the interstellar medium. Four of the double stars contained a Be star. Evidence for intrinsic polarization was found in five systems including two of the Be systems, one double star with a short period eclipsing binary, and two systems containing only normal early type stars for which emission lines have not been previously reported. The interpretation of these observations in terms of individual stellar polarizations and their wavelength dependence is discussed. The theoretical basis for the intrinsic polarization of early type stars is explored with a model for the disk-like extended atmospheres of Be stars. Details of a polarimeter for the measurement of the linear polarization of astronomical point sources are also presented with narrow band (Δ lambda = 100A) measurements of the polarization of γ Cas from lambda 4000 to lambda 5800

Understanding the star formation modes in the distant universe

International Nuclear Information System (INIS)

Salmi, Fadia

2012-01-01

The goal of my PhD study consists at attempt to understand what are the main processes at the origin of the star formation in the galaxies over the last 10 billion years. While it was proposed in the past that merging of galaxies has a dominant role to explain the triggering of the star formation in the distant galaxies having high star formation rates, in the opposite, more recent studies revealed scaling laws linking the star formation rate in the galaxies to their stellar mass or their gas mass. The small dispersion of these laws seems to be in contradiction with the idea of powerful stochastic events due to interactions, but rather in agreement with the new vision of galaxy history where the latter are continuously fed by intergalactic gas. We were especially interested in one of this scaling law, the relation between the star formation (SFR) and the stellar mass (M*) of galaxies, commonly called the main sequence of star forming galaxies. We studied this main sequence, SFR-M"*, in function of the morphology and other physical parameters like the radius, the colour, the clumpiness. The goal was to understand the origin of the sequence's dispersion related to the physical processes underlying this sequence in order to identify the main mode of star formation controlling this sequence. This work needed a multi-wavelength approach as well as the use of galaxies profile simulation to distinguish between the different galaxy morphological types implied in the main sequence. (author) [fr

The relations of child adiposity with parent-to-child and parent-to-parent hostility.

Science.gov (United States)

Lorber, Michael F; White-Ajmani, Mandi L; Dixon, Denise; Slep, Amy M S; Heyman, Richard E

2017-11-01

Investigate (1) the association of child adiposity with parent-to-child and parent-to-parent hostility, (2) the mediation of these associations by dietary behaviours and (3) moderation by gender. One hundred thirty-five couples with 6- to 14-year-old children completed measures of emotional and physical aggression, overreactive discipline and child diet. Parent-to-parent hostility was also coded from laboratory observations. Child adiposity was a combination of body mass index and waist-to-hip ratio. Mother-to-child hostility was associated with child adiposity. This association was concentrated in boys and was not significantly explained by child dietary factors. Mother-to-father hostility was not significantly associated with boys' or girls' adiposity. Girls' adiposity was not significantly associated with family hostility. Fathers' hostility was not linked to child adiposity. This is the first study to take a family-level approach to understanding the relation of hostility to child adiposity by examining relations among adiposity and both mothers' and fathers' hostility directed toward one another and toward their children. Our findings highlight the potential role played by mothers' emotional hostility in boys' adiposity and suggest that, if this role is further substantiated, mother-son emotional hostility may be a promising target for the prevention of child obesity.

Spacecraft angular velocity estimation algorithm for star tracker based on optical flow techniques

Science.gov (United States)

Tang, Yujie; Li, Jian; Wang, Gangyi

2018-02-01

An integrated navigation system often uses the traditional gyro and star tracker for high precision navigation with the shortcomings of large volume, heavy weight and high-cost. With the development of autonomous navigation for deep space and small spacecraft, star tracker has been gradually used for attitude calculation and angular velocity measurement directly. At the same time, with the dynamic imaging requirements of remote sensing satellites and other imaging satellites, how to measure the angular velocity in the dynamic situation to improve the accuracy of the star tracker is the hotspot of future research. We propose the approach to measure angular rate with a nongyro and improve the dynamic performance of the star tracker. First, the star extraction algorithm based on morphology is used to extract the star region, and the stars in the two images are matched according to the method of angular distance voting. The calculation of the displacement of the star image is measured by the improved optical flow method. Finally, the triaxial angular velocity of the star tracker is calculated by the star vector using the least squares method. The method has the advantages of fast matching speed, strong antinoise ability, and good dynamic performance. The triaxial angular velocity of star tracker can be obtained accurately with these methods. So, the star tracker can achieve better tracking performance and dynamic attitude positioning accuracy to lay a good foundation for the wide application of various satellites and complex space missions.

The Drifting Star

Science.gov (United States)

2008-04-01

By studying in great detail the 'ringing' of a planet-harbouring star, a team of astronomers using ESO's 3.6-m telescope have shown that it must have drifted away from the metal-rich Hyades cluster. This discovery has implications for theories of star and planet formation, and for the dynamics of our Milky Way. ESO PR Photo 09a/08 ESO PR Photo 09a/08 Iota Horologii The yellow-orange star Iota Horologii, located 56 light-years away towards the southern Horologium ("The Clock") constellation, belongs to the so-called "Hyades stream", a large number of stars that move in the same direction. Previously, astronomers using an ESO telescope had shown that the star harbours a planet, more than 2 times as large as Jupiter and orbiting in 320 days (ESO 12/99). But until now, all studies were unable to pinpoint the exact characteristics of the star, and hence to understand its origin. A team of astronomers, led by Sylvie Vauclair from the University of Toulouse, France, therefore decided to use the technique of 'asteroseismology' to unlock the star's secrets. "In the same way as geologists monitor how seismic waves generated by earthquakes propagate through the Earth and learn about the inner structure of our planet, it is possible to study sound waves running through a star, which forms a sort of large, spherical bell," says Vauclair. The 'ringing' from this giant musical instrument provides astronomers with plenty of information about the physical conditions in the star's interior. And to 'listen to the music', the astronomers used one of the best instruments available. The observations were conducted in November 2006 during 8 consecutive nights with the state-of-the-art HARPS spectrograph mounted on the ESO 3.6-m telescope at La Silla. Up to 25 'notes' could be identified in the unique dataset, most of them corresponding to waves having a period of about 6.5 minutes. These observations allowed the astronomers to obtain a very precise portrait of Iota Horologii: its

A Semiautomatic Pipeline for Be Star Light Curves

Science.gov (United States)

Rímulo, L. R.; Carciofi, A. C.; Rivinius, T.; Okazaki, A.

2016-11-01

Observational and theoretical studies from the last decade have shown that the Viscous Decretion Disk (VDD) scenario, in which turbulent viscosity is the physical mechanism responsible for the transport of material and angular momentum ejected from the star to the outer regions of the disk, is the only viable model for explaining the circumstellar disks of Be stars. In the α-disk approach applied to the VDD, the dimensionless parameter α is a measure of the turbulent viscosity. Recently, combining the time-dependent evolution of a VDD α-disk with non-LTE radiative transfer calculations, the first measurement of the α parameter was made, for the disk dissipation of the Be star ω CMa. It was found that α≍ 1 for that Be disk. The main motivation of this present work is the statistical determination of the α parameter. For this purpose, we present a pipeline that will allow the semiautomatic determination of the α parameter of several dozens of light curves of Be stars available from photometric surveys, In this contribution, we describe the pipeline, outlining the main staps required for the semiautomatic analysis of light curves

INFRARED TWO-COLOR DIAGRAMS FOR AGB STARS, POST-AGB STARS, AND PLANETARY NEBULAE

Energy Technology Data Exchange (ETDEWEB)

Suh, Kyung-Won, E-mail: kwsuh@chungbuk.ac.kr [Department of Astronomy and Space Science, Chungbuk National University, Cheongju-City, 362-763 (Korea, Republic of)

2015-08-01

We present various infrared two-color diagrams (2CDs) for asymptotic giant branch (AGB) stars, post-AGB stars, and Planetary Nebulae (PNe) and investigate possible evolutionary tracks. We use catalogs from the available literature for the sample of 4903 AGB stars (3373 O-rich; 1168 C-rich; 362 S-type), 660 post-AGB stars (326 post-AGB; 334 pre-PN), and 1510 PNe in our Galaxy. For each object in the catalog, we cross-identify the IRAS, AKARI, Midcourse Space Experiment, and 2MASS counterparts. The IR 2CDs can provide useful information about the structure and evolution of the dust envelopes as well as the central stars. To find possible evolutionary tracks from AGB stars to PNe on the 2CDs, we investigate spectral evolution of post-AGB stars by making simple but reasonable assumptions on the evolution of the central star and dust shell. We perform radiative transfer model calculations for the detached dust shells around evolving central stars in the post-AGB phase. We find that the theoretical dust shell model tracks using dust opacity functions of amorphous silicate and amorphous carbon roughly coincide with the densely populated observed points of AGB stars, post-AGB stars, and PNe on various IR 2CDs. Even though some discrepancies are inevitable, the end points of the theoretical post-AGB model tracks generally converge in the region of the observed points of PNe on most 2CDs.

Interacting binary stars

CERN Document Server

Sahade, Jorge; Ter Haar, D

1978-01-01

Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

New red giant star in the Kepler open cluster NGC 6819

Science.gov (United States)

Komucyeya, E.; Abedigamba, O. P.; Jurua, E.; Anguma, S. K.

2018-05-01

A recent study indicated that 39 red giant stars showing solar-like oscillations were discovered in the field of Kepleropen cluster NGC 6819. The study was based on photometric distance estimates of 27 stars out of the 39. Using photometric method alone may not be adequate to confirm the membership of these stars. The stars were not previously known in literature to belong to the open cluster NGC 6819. In this study, Kepler data was used to study the membership of the 27 stars. A plot of apparent magnitude as a function of the large frequency separation, supplemented with the proper motion and radial velocity values from literature revealed KIC 5112840 to lie on the same plane with the well known members of the cluster. Echelle diagram was constructed, and the median gravity-mode period spacings (ΔP) calculated for KIC 5112840. A value of ΔP = 66.3 s was obtained, thus placing the red giant star KIC 5112840 on the Red Giant Branch stage of evolution. Our evolutionary status result using the approach in this paper is in agreement with what is in the available literature.

Gamow's calculation of the neutron star's critical mass revised

International Nuclear Information System (INIS)

Ludwig, Hendrik; Ruffini, Remo

2014-01-01

It has at times been indicated that Landau introduced neutron stars in his classic paper of 1932. This is clearly impossible because the discovery of the neutron by Chadwick was submitted more than one month after Landau's work. Therefore, and according to his calculations, what Landau really did was to study white dwarfs, and the critical mass he obtained clearly matched the value derived by Stoner and later by Chandrasekhar. The birth of the concept of a neutron star is still today unclear. Clearly, in 1934, the work of Baade and Zwicky pointed to neutron stars as originating from supernovae. Oppenheimer in 1939 is also well known to have introduced general relativity (GR) in the study of neutron stars. The aim of this note is to point out that the crucial idea for treating the neutron star has been advanced in Newtonian theory by Gamow. However, this pioneering work was plagued by mistakes. The critical mass he should have obtained was 6.9 M, not the one he declared, namely, 1.5 M. Probably, he was taken to this result by the work of Landau on white dwarfs. We revise Gamow's calculation of the critical mass regarding calculational and conceptual aspects and discuss whether it is justified to consider it the first neutron-star critical mass. We compare Gamow's approach to other early and modern approaches to the problem.

Wolf-Rayet stars and O-star runaways with HIPPARCOS - I. Kinematics

NARCIS (Netherlands)

Moffat, AFJ; Marchenko, SV; Seggewiss, W; van der Hucht, KA; Schrijver, H; Stenholm, B; Lundstrom, [No Value; Gunawan, DYAS; Sutantyo, W; van den Heuvel, EPJ; De Cuyper, JP; Gomez, AE

Reliable systemic radial velocities are almost impossible to secure for Wolf-Rayet stars, difficult for O stars. Therefore, to study the motions - both systematic in the Galaxy and peculiar - of these two related types of hot, luminous star, we have examined the Hipparcos proper motions of some 70

Evolution of variable stars

International Nuclear Information System (INIS)

Becker, S.A.

1986-08-01

Throughout the domain of the H R diagram lie groupings of stars whose luminosity varies with time. These variable stars can be classified based on their observed properties into distinct types such as β Cephei stars, δ Cephei stars, and Miras, as well as many other categories. The underlying mechanism for the variability is generally felt to be due to four different causes: geometric effects, rotation, eruptive processes, and pulsation. In this review the focus will be on pulsation variables and how the theory of stellar evolution can be used to explain how the various regions of variability on the H R diagram are populated. To this end a generalized discussion of the evolutionary behavior of a massive star, an intermediate mass star, and a low mass star will be presented. 19 refs., 1 fig., 1 tab

Parenting dimensions and styles: a brief history and recommendations for future research.

Science.gov (United States)

Power, Thomas G

2013-08-01

Over the last decade, researchers have uncovered relationships between general parenting styles and children's obesity. This is an emerging area of research, and there currently is a great deal of interest in the parent's role. This review was written to provide researchers entering this area with a historical introduction to parenting research and to point to some directions for future inquiry. Over the last 75 years, considerable insight has been gained into individual differences in parenting behavior, especially regarding the dimensions underlying individual differences in general parenting approach, and parenting styles resulting from individual differences on these dimensions. The history of empirical attempts to identify parenting dimensions and styles is reviewed briefly, followed by a review of more recent studies of parenting styles. Next is a discussion of data analytic approaches to measuring parenting, with a particular emphasis on variable-centered versus person-centered approaches. Because investigators have often disagreed about which of these approaches is the most appropriate, the advantages and disadvantages of each are considered, along with recommendations for future research.

The Parents' Parenting Patterns, Education, Jobs, and Assistance to Their Children in Watching Television, and Children's Aggressive Behavior

Science.gov (United States)

Purwati; Japar, Muhammad

2016-01-01

The objective of this present is to test the effects of the parents' parenting patterns, education, jobs, and assistance to children in watching television on the children's aggressive behavior. This present research employed a quantitative approach with an ex-post factor design. The data were collected from 175 parents of which the children…

A new method for determining which stars are near a star sensor field-of-view

Science.gov (United States)

Yates, Russell E., Jr.; Vedder, John D.

1991-01-01

A new method is described for determining which stars in a navigation star catalog are near a star sensor field of view (FOV). This method assumes that an estimate of spacecraft inertial attitude is known. Vector component ranges for the star sensor FOV are computed, so that stars whose vector components lie within these ranges are near the star sensor FOV. This method requires no presorting of the navigation star catalog, and is more efficient than tradition methods.

Regulation of hypothalamic-pituitary-interrenal axis function in male smallmouth bass (Micropterus dolomieu) during parental care.

Science.gov (United States)

Jeffrey, J D; Cooke, S J; Gilmour, K M

2014-08-01

Male smallmouth bass (Micropterus dolomieu) provide sole parental care until offspring reach independence, a period of several weeks. During the early parental care period when males are guarding fresh eggs (MG-FE), cortisol responsiveness is attenuated; the response is re-established when males reach the end of the parental care period and are guarding free-swimming fry (MG-FSF). It was hypothesized that attenuation of the cortisol response in male smallmouth bass during early parental care reflected modulation of hypothalamic-pituitary-interrenal (HPI) axis function. Male smallmouth bass were sampled at the beginning (MG-FE) and end of the parental care period (MG-FSF), before and/or 25 min after exposure to a standardized stressor consisting of 3 min of air exposure. Repeated sampling of stressed fish for analysis of plasma cortisol and adrenocorticotropic hormone (ACTH) levels was carried out. Males significantly elevated both plasma cortisol and ACTH levels when guarding free-swimming fry but not during early parental care. Control and stressed fish were terminally sampled for tissue mRNA abundance of preoptic area (POA) and hypothalamic corticotropin-releasing factor (CRF) as well as head kidney melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage enzyme (P450scc). No significant differences in either hypothalamus CRF or head kidney P450scc mRNA abundance were found across parental care stages or in response to stress. However, POA CRF mRNA abundance and interrenal cell MC2R and StAR mRNA abundances failed to increase in response to stress in MG-FE. Thus, the attenuated cortisol response in males guarding fresh eggs may be explained by hypoactive HPI axis function in response to stress. The present is one of few studies, and the first teleost study, to address the mechanisms underlying resistance to stress during the reproductive/parental care period. Copyright © 2014 Elsevier Inc. All rights

Star identification methods, techniques and algorithms

CERN Document Server

Zhang, Guangjun

2017-01-01

This book summarizes the research advances in star identification that the author’s team has made over the past 10 years, systematically introducing the principles of star identification, general methods, key techniques and practicable algorithms. It also offers examples of hardware implementation and performance evaluation for the star identification algorithms. Star identification is the key step for celestial navigation and greatly improves the performance of star sensors, and as such the book include the fundamentals of star sensors and celestial navigation, the processing of the star catalog and star images, star identification using modified triangle algorithms, star identification using star patterns and using neural networks, rapid star tracking using star matching between adjacent frames, as well as implementation hardware and using performance tests for star identification. It is not only valuable as a reference book for star sensor designers and researchers working in pattern recognition and othe...

How Very Massive Metal Free Stars Start Cosmological Reionization

International Nuclear Information System (INIS)

Wise, John H.; Abel, Tom

2007-01-01

The initial conditions and relevant physics for the formation of the earliest galaxies are well specified in the concordance cosmology. Using ab initio cosmological Eulerian adaptive mesh refinement radiation hydrodynamical calculations, we discuss how very massive stars start the process of cosmological reionization. The models include non-equilibrium primordial gas chemistry and cooling processes and accurate radiation transport in the Case B approximation using adaptively ray traced photon packages, retaining the time derivative in the transport equation. Supernova feedback is modeled by thermal explosions triggered at parsec scales. All calculations resolve the local Jeans length by at least 16 grid cells at all times and as such cover a spatial dynamic range of ∼10 6 . These first sources of reionization are highly intermittent and anisotropic and first photoionize the small scales voids surrounding the halos they form in, rather than the dense filaments they are embedded in. As the merging objects form larger, dwarf sized galaxies, the escape fraction of UV radiation decreases and the H II regions only break out on some sides of the galaxies making them even more anisotropic. In three cases, SN blast waves induce star formation in overdense regions that were formed earlier from ionization front instabilities. These stars form tens of parsecs away from the center of their parent DM halo. Approximately 5 ionizing photons are needed per sustained ionization when star formation in 10 6 M · halos are dominant in the calculation. As the halos become larger than ∼10 7 M # circle d ot#, the ionizing photon escape fraction decreases, which in turn increases the number of photons per ionization to 15--50, in calculations with stellar feedback only. Supernova feedback in these more massive halos creates a more diffuse medium, allowing the stellar radiation to escape more easily and maintaining the ratio of 5 ionizing photons per sustained ionization

On the evolution of stars

International Nuclear Information System (INIS)

Kippenhahn, R.

1989-01-01

A popular survey is given of the present knowledge on evolution and ageing of stars. Main sequence stars, white dwarf stars, and red giant stars are classified in the Hertzsprung-Russell (HR)-diagram by measurable quantities: surface temperature and luminosity. From the HR-diagram it can be concluded to star mass and age. Star-forming processes in interstellar clouds as well as stellar burning processes are illustrated. The changes occurring in a star due to the depletion of the nuclear energy reserve are described. In this frame the phenomena of planetary nebulae, supernovae, pulsars, neutron stars as well as of black holes are explained

Self and collective dynamics of ordered star polymer solutions

CERN Document Server

Stellbrink, J; Monkenbusch, M; Richter, D; Ehlers, G; Schleger, P

2002-01-01

We investigated the dynamics of 18-arm polyisoprene star polymer solutions well above their overlap concentration c sup *. Combining neutron spin echo spectroscopy (NSE) and selective H/D labelling, we were able to separate inter- (collective) and intra-star (self) dynamics. Only at low Q-vectors do self and collective dynamics become discernible. Here, collective dynamics are found to be consistent with a colloidal approach resulting from star-star interactions. The collective short time diffusion coefficient D sub e sub f sub f is well described by the term D sub 0 /S(Q), with D sub 0 the diffusion coefficient at infinite dilution. At Q sub m , the peak position in the structure factor S(Q), no difference is observable between collective and self dynamics. For covering the slowed-down dynamics at Q sub m the time range of NSE was extended for the first time up to 350 ns using long wavelengths, lambda=19 A, at IN15 (ILL, Grenoble). We found that S(Q,t)/S(Q,0) relaxes into a concentration-dependent plateau. T...

MAGNETIC FIELDS OF STARS

OpenAIRE

Bychkov, V. D.; Bychkova, L. V.; Madej, J.

2008-01-01

Now it is known about 1212 stars of the main sequence and giants (from them 610 stars - it is chemically peculiarity (CP) stars) for which direct measurements of magnetic fields were spent (Bychkov et al.,2008). Let's consider, what representations were generated about magnetic fields (MT) of stars on the basis of available observations data.

Extreme Variables in Star Forming Regions

Science.gov (United States)

Contreras Peña, Carlos Eduardo

2015-01-01

The notion that low- to intermediate-mass young stellar objects (YSOs) gain mass at a constant rate during the early stages of their evolution appears to be challenged by observations of YSOs suffering sudden increases of the rate at which they gain mass from their circumstellar discs. Also, this idea that stars spend most of their lifetime with a low accretion rate and gain most of their final mass during short-lived episodes of high accretion bursts, helps to solve some long-standing problems in stellar evolution. The original classification of eruptive variables divides them in two separate subclasses known as FU Orionis stars (FUors) and EX Lupi stars (EXors). In this classical view FUors are at an early evolutionary stage and are still gaining mass from their parent envelopes, whilst EXors are thought to be older objects only surrounded by an accretion disc. The problem with this classical view is that it excludes younger protostars which have higher accretion rates but are too deeply embedded in circumstellar matter to be observed at optical wavelengths. Optically invisible protostars have been observed to display large variability in the near-infrared. These and some recent discoveries of new eruptive variables, show characteristics that can be attributed to both of the optically-defined subclasses of eruptive variables. The new objects have been proposed to be part of a new class of eruptive variables. However, a more accepted scenario is that in fact the original classes only represent two extremes of the same phenomena. In this sense eruptive variability could be explained as arising from one physical mechanism, i.e. unsteady accretion, where a variation in the parameters of such mechanism can cause the different characteristics observed in the members of this class. With the aim of studying the incidence of episodic accretion among young stellar objects, and to characterize the nature of these eruptive variables we searched for high amplitude variability

Which of Kepler's Stars Flare?

Science.gov (United States)

Kohler, Susanna

2017-12-01

The habitability of distant exoplanets is dependent upon many factors one of which is the activity of their host stars. To learn about which stars are most likely to flare, a recent study examines tens of thousands of stellar flares observed by Kepler.Need for a Broader SampleArtists rendering of a flaring dwarf star. [NASAs Goddard Space Flight Center/S. Wiessinger]Most of our understanding of what causes a star to flare is based on observations of the only star near enough to examine in detail the Sun. But in learning from a sample size of one, a challenge arises: we must determine which conclusions are unique to the Sun (or Sun-like stars), and which apply to other stellar types as well.Based on observations and modeling, astronomers think that stellar flares result from the reconnection of magnetic field lines in a stars outer atmosphere, the corona. The magnetic activity is thought to be driven by a dynamo caused by motions in the stars convective zone.HR diagram of the Kepler stars, with flaring main-sequence (yellow), giant (red) and A-star (green) stars in the authors sample indicated. [Van Doorsselaere et al. 2017]To test whether these ideas are true generally, we need to understand what types of stars exhibit flares, and what stellar properties correlate with flaring activity. A team of scientists led by Tom Van Doorsselaere (KU Leuven, Belgium) has now used an enormous sample of flares observed by Kepler to explore these statistics.Intriguing TrendsVan Doorsselaere and collaborators used a new automated flare detection and characterization algorithm to search through the raw light curves from Quarter 15 of the Kepler mission, building a sample of 16,850 flares on 6,662 stars. They then used these to study the dependence of the flare occurrence rate, duration, energy, and amplitude on the stellar spectral type and rotation period.This large statistical study led the authors to several interesting conclusions, including:Flare star incidence rate as a a

Symbiotic stars

Science.gov (United States)

Kafatos, M.; Michalitsianos, A. G.

1984-01-01

The physical characteristics of symbiotic star systems are discussed, based on a review of recent observational data. A model of a symbiotic star system is presented which illustrates how a cool red-giant star is embedded in a nebula whose atoms are ionized by the energetic radiation from its hot compact companion. UV outbursts from symbiotic systems are explained by two principal models: an accretion-disk-outburst model which describes how material expelled from the tenuous envelope of the red giant forms an inwardly-spiralling disk around the hot companion, and a thermonuclear-outburst model in which the companion is specifically a white dwarf which superheats the material expelled from the red giant to the point where thermonuclear reactions occur and radiation is emitted. It is suspected that the evolutionary course of binary systems is predetermined by the initial mass and angular momentum of the gas cloud within which binary stars are born. Since red giants and Mira variables are thought to be stars with a mass of one or two solar mass, it is believed that the original cloud from which a symbiotic system is formed can consist of no more than a few solar masses of gas.

Massive stars in galaxies

International Nuclear Information System (INIS)

Humphreys, R.M.

1987-01-01

The relationship between the morphologic type of a galaxy and the evolution of its massive stars is explored, reviewing observational results for nearby galaxies. The data are presented in diagrams, and it is found that the massive-star populations of most Sc spiral galaxies and irregular galaxies are similar, while those of Sb spirals such as M 31 and M 81 may be affected by morphology (via differences in the initial mass function or star-formation rate). Consideration is also given to the stability-related upper luminosity limit in the H-R diagram of hypergiant stars (attributed to radiation pressure in hot stars and turbulence in cool stars) and the goals of future observation campaigns. 88 references

HAT-P-11b: A SUPER-NEPTUNE PLANET TRANSITING A BRIGHT K STAR IN THE KEPLER FIELD

International Nuclear Information System (INIS)

Bakos, G. A.; Torres, G.; Pal, A.; Hartman, J.; Noyes, R. W.; Latham, D. W.; Sasselov, D. D.; Sipocz, B.; Esquerdo, G. A.; Kovacs, Gabor; Fernandez, J.; Kovacs, Geza; Moor, A.; Fischer, D. A.; Isaacson, H.; Johnson, J. A.; Marcy, G. W.; Howard, A.; Butler, R. P.; Vogt, S.

2010-01-01

We report on the discovery of HAT-P-11b, the smallest radius transiting extrasolar planet (TEP) discovered from the ground, and the first hot Neptune discovered to date by transit searches. HAT-P-11b orbits the bright (V = 9.587) and metal rich ([Fe/H] = +0.31 ± 0.05) K4 dwarf star GSC 03561-02092 with P = 4.8878162 ± 0.0000071 days and produces a transit signal with depth of 4.2 mmag, the shallowest found by transit searches that is due to a confirmed planet. We present a global analysis of the available photometric and radial velocity (RV) data that result in stellar and planetary parameters, with simultaneous treatment of systematic variations. The planet, like its near-twin GJ 436b, is somewhat larger than Neptune (17 M + , 3.8 R + ) both in mass M p = 0.081 ± 0.009 M J (25.8 ± 2.9 M + ) and radius R p = 0.422 ± 0.014 R J (4.73 ± 0.16 R + ). HAT-P-11b orbits in an eccentric orbit with e = 0.198 ± 0.046 and ω = 355. 0 2 ± 17. 0 3, causing a reflex motion of its parent star with amplitude 11.6 ± 1.2 m s -1 , a challenging detection due to the high level of chromospheric activity of the parent star. Our ephemeris for the transit events is T c = 2454605.89132 ± 0.00032 (BJD), with duration 0.0957 ± 0.0012 days, and secondary eclipse epoch of 2454608.96 ± 0.15 days (BJD). The basic stellar parameters of the host star are M * = 0.809 +0.020 -0.027 M sun , R * = 0.752 ± 0.021 R sun , and T eff* = 4780 ± 50 K. Importantly, HAT-P-11 will lie on one of the detectors of the forthcoming Kepler mission; this should make possible fruitful investigations of the detailed physical characteristic of both the planet and its parent star at unprecedented precision. We discuss an interesting constraint on the eccentricity of the system by the transit light curve and stellar parameters. This will be particularly useful for eccentric TEPs with low-amplitude RV variations in Kepler's field. We also present a blend analysis, that for the first time treats the case of a

GMC Collisions as Triggers of Star Formation. III. Density and Magnetically Regulated Star Formation

Energy Technology Data Exchange (ETDEWEB)

Wu, Benjamin [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Tan, Jonathan C. [Department of Physics, University of Florida, Gainesville, FL 32611 (United States); Christie, Duncan [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Nakamura, Fumitaka [National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Van Loo, Sven [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Collins, David, E-mail: ben.wu@nao.ac.jp [Department of Physics, Florida State University, Tallahassee, FL 32306-4350 (United States)

2017-06-01

We study giant molecular cloud (GMC) collisions and their ability to trigger star cluster formation. We further develop our three-dimensional magnetized, turbulent, colliding GMC simulations by implementing star formation subgrid models. Two such models are explored: (1) “Density-Regulated,” i.e., fixed efficiency per free-fall time above a set density threshold and (2) “Magnetically Regulated,” i.e., fixed efficiency per free-fall time in regions that are magnetically supercritical. Variations of parameters associated with these models are also explored. In the non-colliding simulations, the overall level of star formation is sensitive to model parameter choices that relate to effective density thresholds. In the GMC collision simulations, the final star formation rates and efficiencies are relatively independent of these parameters. Between the non-colliding and colliding cases, we compare the morphologies of the resulting star clusters, properties of star-forming gas, time evolution of the star formation rate (SFR), spatial clustering of the stars, and resulting kinematics of the stars in comparison to the natal gas. We find that typical collisions, by creating larger amounts of dense gas, trigger earlier and enhanced star formation, resulting in 10 times higher SFRs and efficiencies. The star clusters formed from GMC collisions show greater spatial substructure and more disturbed kinematics.

An Autonomous Star Identification Algorithm Based on One-Dimensional Vector Pattern for Star Sensors.

Science.gov (United States)

Luo, Liyan; Xu, Luping; Zhang, Hua

2015-07-07

In order to enhance the robustness and accelerate the recognition speed of star identification, an autonomous star identification algorithm for star sensors is proposed based on the one-dimensional vector pattern (one_DVP). In the proposed algorithm, the space geometry information of the observed stars is used to form the one-dimensional vector pattern of the observed star. The one-dimensional vector pattern of the same observed star remains unchanged when the stellar image rotates, so the problem of star identification is simplified as the comparison of the two feature vectors. The one-dimensional vector pattern is adopted to build the feature vector of the star pattern, which makes it possible to identify the observed stars robustly. The characteristics of the feature vector and the proposed search strategy for the matching pattern make it possible to achieve the recognition result as quickly as possible. The simulation results demonstrate that the proposed algorithm can effectively accelerate the star identification. Moreover, the recognition accuracy and robustness by the proposed algorithm are better than those by the pyramid algorithm, the modified grid algorithm, and the LPT algorithm. The theoretical analysis and experimental results show that the proposed algorithm outperforms the other three star identification algorithms.

Subluminous Wolf-Rayet stars: Observations

International Nuclear Information System (INIS)

Heap, S.R.

1982-01-01

The author has used the fact that some central stars are WR stars and others are say, O stars, as a focal point for his presentation. In attempting to answer this question he has considered how the properties of WR-type central stars differ from those of O-type stars. The study begins with the classification and calibration of WR spectra, then goes on to the physical properties of WR-type central stars, and at the end returns to the question of what distinguishes a Wolf-Rayet star. The observational data for central stars are neither complete nor precise. Nevertheless, they suggest that what distinguishes a WR central star is not so much its present physical properties (e.g. temperature, gravity), but rather, its fundamental properties (initial and evolutionary history). (Auth.)

But I Trust My Teen: Parents' Attitudes and Response to a Parental Monitoring Intervention

Directory of Open Access Journals (Sweden)

Aaron Metzger

2012-01-01

Full Text Available Parental knowledge gained from monitoring activities protects against adolescent risk involvement. Parental monitoring approaches are varied and may be modified with successful interventions but not all parents or adolescents respond to monitoring programs the same way. 339 parent-adolescent dyads randomized to receive a parental monitoring intervention and 169 parent-adolescent dyads in the control group were followed for one year over four measurement periods. Parent attitudes about the usefulness of monitoring, the importance of trust and respecting their teens’ privacy, and the appropriateness of adolescent risk-taking behavior and experimentation were examined as predictors of longitudinal change in parental monitoring and open communication. Similar effects were found in both the intervention and control group models regarding open communication. Parental attitudes impacted longitudinal patterns of teen-reported parent monitoring, and these patterns differed across experimental groups. In the intervention group, parents’ beliefs about the importance of trust and privacy were associated with a steeper decline in monitoring across time. Finally, parents’ attitudes about the normative nature of teen experimentation were associated with a quadratic parental monitoring time trend in the intervention but not the control group. These findings suggest that parental attitudes may impact how families respond to an adolescent risk intervention.

Pharmacotherapy for parents with attention-deficit hyperactivity disorder (ADHD): impact on maternal ADHD and parenting.

Science.gov (United States)

Chronis-Tuscano, Andrea; Stein, Mark A

2012-09-01

Given the high heritability of the disorder, attention-deficit hyperactivity disorder (ADHD) is common among parents of children with ADHD. Parental ADHD is associated with maladaptive parenting, negative parent-child interaction patterns and a diminished response to behavioural parent training. We describe our previous research demonstrating that stimulant medications for mothers with ADHD are associated with reductions in maternal ADHD symptoms. Although limited beneficial effects on self-reported parenting were also found in our study, the impact of ADHD medications on functional outcomes related to parenting and family interactions may not be sufficient for many families. Many questions remain with regard to how best to treat multiplex ADHD families in which a parent and child have ADHD. In particular, future studies are needed: (1) to evaluate how best to sequence pharmacotherapy, psychosocial treatment for adult ADHD and behavioural parenting interventions; (2) to determine the best approach to maintaining treatment effects over the long term for both parents and children; and (3) to identify individual predictors of treatment response.

America's Star Libraries

Science.gov (United States)

Lyons, Ray; Lance, Keith Curry

2009-01-01

"Library Journal"'s new national rating of public libraries, the "LJ" Index of Public Library Service, identifies 256 "star" libraries. It rates 7,115 public libraries. The top libraries in each group get five, four, or three Michelin guide-like stars. All included libraries, stars or not, can use their scores to learn from their peers and improve…

Observing Double Stars

Science.gov (United States)

Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

2012-05-01

Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

Neutrino Processes in Neutron Stars

Directory of Open Access Journals (Sweden)

Kolomeitsev E.E.

2010-10-01

Full Text Available The aim of these lectures is to introduce basic processes responsible for cooling of neutron stars and to show how to calculate the neutrino production rate in dense strongly interacting nuclear medium. The formalism is presented that treats on equal footing one-nucleon and multiple-nucleon processes and reactions with virtual bosonic modes and condensates. We demonstrate that neutrino emission from dense hadronic component in neutron stars is subject of strong modifications due to collective effects in the nuclear matter. With the most important in-medium processes incorporated in the cooling code an overall agreement with available soft X ray data can be easily achieved. With these findings the so-called “standard” and “non-standard” cooling scenarios are replaced by one general “nuclear medium cooling scenario” which relates slow and rapid neutron star coolings to the star masses (interior densities. The lectures are split in four parts. Part I: After short introduction to the neutron star cooling problem we show how to calculate neutrino reaction rates of the most efficient one-nucleon and two-nucleon processes. No medium effects are taken into account in this instance. The effects of a possible nucleon pairing are discussed. We demonstrate that the data on neutron star cooling cannot be described without inclusion of medium effects. It motivates an assumption that masses of the neutron stars are different and that neutrino reaction rates should be strongly density dependent. Part II: We introduce the Green’s function diagram technique for systems in and out of equilibrium and the optical theorem formalism. The latter allows to perform calculations of production rates with full Green’s functions including all off-mass-shell effects. We demonstrate how this formalism works within the quasiparticle approximation. Part III: The basic concepts of the nuclear Fermi liquid approach are introduced. We show how strong

Neutron star natal kicks and the long-term survival of star clusters

Science.gov (United States)

Contenta, Filippo; Varri, Anna Lisa; Heggie, Douglas C.

2015-04-01

We investigate the dynamical evolution of a star cluster in an external tidal field by using N-body simulations, with focus on the effects of the presence or absence of neutron star natal velocity kicks. We show that, even if neutron stars typically represent less than 2 per cent of the total bound mass of a star cluster, their primordial kinematic properties may affect the lifetime of the system by up to almost a factor of 4. We interpret this result in the light of two known modes of star cluster dissolution, dominated by either early stellar evolution mass-loss or two-body relaxation. The competition between these effects shapes the mass-loss profile of star clusters, which may either dissolve abruptly (`jumping'), in the pre-core-collapse phase, or gradually (`skiing'), after having reached core collapse.

Hyperfast pulsars as the remnants of massive stars ejected from young star clusters

Science.gov (United States)

Gvaramadze, Vasilii V.; Gualandris, Alessia; Portegies Zwart, Simon

2008-04-01

Recent proper motion and parallax measurements for the pulsar PSR B1508+55 indicate a transverse velocity of ~1100kms-1, which exceeds earlier measurements for any neutron star. The spin-down characteristics of PSR B1508+55 are typical for a non-recycled pulsar, which implies that the velocity of the pulsar cannot have originated from the second supernova disruption of a massive binary system. The high velocity of PSR B1508+55 can be accounted for by assuming that it received a kick at birth or that the neutron star was accelerated after its formation in the supernova explosion. We propose an explanation for the origin of hyperfast neutron stars based on the hypothesis that they could be the remnants of a symmetric supernova explosion of a high-velocity massive star which attained its peculiar velocity (similar to that of the pulsar) in the course of a strong dynamical three- or four-body encounter in the core of dense young star cluster. To check this hypothesis, we investigated three dynamical processes involving close encounters between: (i) two hard massive binaries, (ii) a hard binary and an intermediate-mass black hole (IMBH) and (iii) a single stars and a hard binary IMBH. We find that main-sequence O-type stars cannot be ejected from young massive star clusters with peculiar velocities high enough to explain the origin of hyperfast neutron stars, but lower mass main-sequence stars or the stripped helium cores of massive stars could be accelerated to hypervelocities. Our explanation for the origin of hyperfast pulsars requires a very dense stellar environment of the order of 106- 107starspc-3. Although such high densities may exist during the core collapse of young massive star clusters, we caution that they have never been observed.

Seven-star needle stimulation improves language and social interaction of children with autistic spectrum disorders.

Science.gov (United States)

Chan, Agnes S; Cheung, Mei-Chun; Sze, Sophia L; Leung, Winnie W

2009-01-01

This is a randomized controlled trial that aimed to evaluate the effect of the Seven-star Needle Stimulation treatment on children with Autistic Spectrum Disorders (ASD). Thirty-two children with ASD were assigned randomly into the treatment and control groups. Children in the treatment group underwent 30 sessions of stimulation over 6 weeks, while children in the control group were on a waiting list and did not receive treatment during this period of time. Intervention consisted of a treatment regime comprising of 30 sessions of Seven-star Needle Stimulation, delivered over 6 weeks. Each session lasted 5 to 10 min, children in the treatment group were stimulated at the front and back sides of their body and the head by using Seven-star Needles. The change in the children's behavior was evaluated using parents' report and neurophysiological changes were measured by quantitative EEG (qEEG). Results showed that the treatment group demonstrated significant improvement in language and social interaction, but not in stereotyped behavior or motor function, compared to the control group. qEEG spectral amplitudes in the treatment, but not in the control group, were also reduced significantly. The results suggested that Seven-star Needle Stimulation might be an effective intervention to improve language and social functioning of children with ASD.

Parents who use drugs

DEFF Research Database (Denmark)

Rhodes, Tim; Bernays, Sarah; Houmøller, Kathrin

2010-01-01

Parents who use drugs parent in a context of heightened concern regarding the damaging effects of parental drug use on child welfare and family life. Yet there is little research exploring how parents who use drugs account for such damage and its limitation. We draw here upon analyses of audio......-recorded depth qualitative interviews, conducted in south-east England between 2008 and 2009, with 29 parents who use drugs. Our approach to thematic analysis treated accounts as co-produced and socially situated. An over-arching theme of accounts was 'damage limitation'. Most damage limitation work centred...... on efforts to create a sense of normalcy of family life, involving keeping drug use secret from children, and investing heavily in strategies to maintain ambiguity regarding children's awareness. Our analysis highlights that damage limitation strategies double-up in accounts as resources of child protection...