Development and implementation of a virtual laboratory for training process improvement in the mechanics of continuous media

The project arises from the need to develop improved teaching methodologies in field of the mechanics of continuous media. The objective is to offer the student a learning process to acquire the necessary theoretical knowledge, cognitive skills and the responsibility and autonomy to professional development in this area. Traditionally the teaching of the concepts of these subjects was performed through lectures and laboratory practice. During these lessons the students attitude was usually passive, and therefore their effectiveness was poor. The proposed methodology has already been successfully employed in universities like University Bochum, Germany, University the South Australia and aims to improve the effectiveness of knowledge acquisition through use by the student of a virtual laboratory. This laboratory allows to adapt the curricula and learning techniques to the European Higher Education and improve current learning processes in the University School of Public Works Engineers -EUITOP- of the Technical University of Madrid -UPM-, due there are not laboratories in this specialization. The virtual space is created using a software platform built on OpenSim, manages 3D virtual worlds, and, language LSL -Linden Scripting Language-, which imprints specific powers to objects. The student or user can access this virtual world through their avatar -your character in the virtual world- and can perform practices within the space created for the purpose, at any time, just with computer with internet access and viewfinder. The virtual laboratory has three partitions. The virtual meeting rooms, where the avatar can interact with peers, solve problems and exchange existing documentation in the virtual library. The interactive game room, where the avatar is has to resolve a number of issues in time. And the video room where students can watch instructional videos and receive group lessons. Each audiovisual interactive element is accompanied by explanations framing it within the area of knowledge and enables students to begin to acquire a vocabulary and practice of the profession for which they are being formed. Plane elasticity concepts are introduced from the tension and compression testing of test pieces of steel and concrete. The behavior of reticulated and articulated structures is reinforced by some interactive games and concepts of tension, compression, local and global buckling will by tests to break articulated structures. Pure bending concepts, simple and composite torsion will be studied by observing a flexible specimen. Earthquake resistant design of buildings will be checked by a laboratory test video.

Bioaccessibility of heavy metals and risk assessment in urban gardens of Madrid

Human health problems and solutions. Urban gardening has spread worldwide in recent years as it enhances food security and selfsupply and promotes community integration. However urban soils are significantly enriched in trace elements relative to background levels. Exposure to the soil in urban gardens may therefore result in adverse health effects depending on the degree of contact during gardening, infant recreational activities and ingestion of vegetables grown in them. In order to evaluate this potential risk, 36 composite samples were collected from the top 20 cm of the soil of 6 urban gardens in Madrid. The aqua regia (pseudototal) and glycine-extractable (bioaccessible) concentrations of Co, Cr, Cu, Ni, Pb and Zn were determined by atomic absorption spectrophotometry. Additionally, pH, texture, Fe, Ca, and Mn concentrations, and organic matter and calcium carbonate contents were determined in all urban gardens and their influence on trace element bioaccessibility was analyzed.

Explicit expressions for solar panel equivalent circuit parameters based on analytical formulation and the Lambert W - Function

Due to the high dependence of photovoltaic energy efficiency on environmental conditions (temperature, irradiation...), it is quite important to perform some analysis focusing on the characteristics of photovoltaic devices in order to optimize energy production, even for small-scale users. The use of equivalent circuits is the preferred option to analyze solar cells/panels performance. However, the aforementioned small-scale users rarely have the equipment or expertise to perform large testing/calculation campaigns, the only information available for them being the manufacturer datasheet. The solution to this problem is the development of new and simple methods to define equivalent circuits able to reproduce the behavior of the panel for any working condition, from a very small amount of information. In the present work a direct and completely explicit method to extract solar cell parameters from the manufacturer datasheet is presented and tested. This method is based on analytical formulation which includes the use of the Lambert W-function to turn the series resistor equation explicit. The presented method is used to analyze the performance (i.e., the I - V curve) of a commercial solar panel at different levels of irradiation and temperature. The analysis performed is based only on the information included in the manufacturer's datasheet.

A language exchange program: sustainability innovation in language and culture engagement

Spanish Educational Laws have been promoting the widespread use of English; as a result, Spanish Uni versities are looking for ways to give students more international training in order to prepare them for a future that will increasingly involve global problems and partnerships. Therefore, the Polytechnic University of Madrid, Spain (UPM), and the University of British Columbia, Okanagan, Canada (UBCO) have come together to offer opportunities for international collaboration and learning, thus facilitating virtual encounters among Spanish and Canadian students. The Language Exchange Program between the UPM and UBCO acts as a model for sustainability innovation in language and culture engagement as the students can interact with native speakers in communication tasks. This interdisciplinary initiative supports the latest methodological principles observed in the Common European Framework for Languages, such as autonomous and life-long learning, self-assessment and peer-assessment as well as the incorporation of new technologies to the learning process. Additionally the ‘virtual’ mobility is provided at no extra cost. This article presents the preliminary results of two virtual exchange programs that have been offering varied forms of study which are venue-independent, and have clearly expanded the range of scenarios for the students on both sides by promoting collaborative work and cultural exchange.

How should the sustainability of the location of dry ports be measured? A proposed methodology using Bayesian networks and multi-criteria decision analysis

The global economic structure, with its decentralized production and the consequent increase in freight traffic all over the world, creates considerable problems and challenges for the freight transport sector. This situation has led shipping to become the most suitable and cheapest way to transport goods. Thus, ports are configured as nodes with critical importance in the logistics supply chain as a link between two transport systems, sea and land. Increase in activity at seaports is producing three undesirable effects: increasing road congestion, lack of open space in port installations and a significant environmental impact on seaports. These adverse effects can be mitigated by moving part of the activity inland. Implementation of dry ports is a possible solution and would also provide an opportunity to strengthen intermodal solutions as part of an integrated and more sustainable transport chain, acting as a link between road and railway networks. In this sense, implementation of dry ports allows the separation of the links of the transport chain, thus facilitating the shortest possible routes for the lowest capacity and most polluting means of transport. Thus, the decision of where to locate a dry port demands a thorough analysis of the whole logistics supply chain, with the objective of transferring the largest volume of goods possible from road to more energy efficient means of transport, like rail or short-sea shipping, that are less harmful to the environment. However, the decision of where to locate a dry port must also ensure the sustainability of the site. Thus, the main goal of this article is to research the variables influencing the sustainability of dry port location and how this sustainability can be evaluated. With this objective, in this paper we present a methodology for assessing the sustainability of locations by the use of Multi-Criteria Decision Analysis (MCDA) and Bayesian Networks (BNs). MCDA is used as a way to establish a scoring, whilst BNs were chosen to eliminate arbitrariness in setting the weightings using a technique that allows us to prioritize each variable according to the relationships established in the set of variables. In order to determine the relationships between all the variables involved in the decision, giving us the importance of each factor and variable, we built a K2 BN algorithm. To obtain the scores of each variable, we used a complete cartography analysed by ArcGIS. Recognising that setting the most appropriate location to place a dry port is a geographical multidisciplinary problem, with significant economic, social and environmental implications, we consider 41 variables (grouped into 17 factors) which respond to this need. As a case of study, the sustainability of all of the 10 existing dry ports in Spain has been evaluated. In this set of logistics platforms, we found that the most important variables for achieving sustainability are those related to environmental protection, so the sustainability of the locations requires a great respect for the natural environment and the urban environment in which they are framed.

Evaluating sustainability and food security of peasant farming systems in Mesoamerican highlands

En las últimas décadas, la agricultura sostenible ha sido objeto de gran interés y debate académico, no sólo en términos conceptuales, sino también en términos metodológicos. La persistencia de la inseguridad alimentaria y el deterioro de los recursos naturales en muchas regiones del mundo, ha provocado el surgimiento de numerosas iniciativas centradas en revitalizar la agricultura campesina así como renovadas discusiones sobre el rol que juega la agricultura como motor de desarrollo y principal actividad para alivio de la pobreza. Por ello, cuando hablamos de evaluar sistemas campesinos de montaña, debemos considerar tanto la dimensión alimentaria como las especificidades propias de los sistemas montañosos como base fundamental de la sostenibilidad. Al evaluar la contribución que han hecho alternativas tecnológicas y de manejo en la mejora de la sostenibilidad y la seguridad alimentaria de los sistemas campesinos de montaña en Mesoamérica, surgen tres preguntas de investigación: • ¿Se está evaluando la sostenibilidad de los sistemas campesinos teniendo en cuenta la variabilidad climática, la participación de los agricultores y las dinámicas temporales? • ¿Podemos rescatar tendencias comunes en estos sistemas y extrapolar los resultados a otras zonas? • ¿Son inequívocamente positivas las alternativas propuestas que se han llevado a cabo? En este trabajo se presentan tres evaluaciones de sostenibilidad que tratan de poner de manifiesto cuáles son los retos y oportunidades que enfrentan actualmente los sistemas campesinos de montaña. En primer lugar, se evalúan tres sistemas de manejo agrícola bajo dos años meteorológicamente contrastantes. Se determinó que durante el año que experimentó lluvias abundantes y temperaturas moderadas, los sistemas de bajos insumos, basados en el uso de abonos orgánicos y rotación de cultivos, obtuvieron los mejores resultados en indicadores ecológicos y similares resultados en los económicos y sociales que el sistema de altos insumos químicos. En el segundo año, con heladas tempranas y sequía invernal, la productividad se redujo para todos los sistemas pero los sistemas más diversificados (en variedades de maíz y/o siembra de otros cultivos) pudieron resistir mejor los contratiempos climáticos. En segundo lugar, se evalúa el grado de conocimiento (percepción) campesino para determinar los factores claves que determinan la sostenibilidad de sus sistemas y su seguridad alimentaria. Se determinó que los principales puntos críticos identificados por los campesinos (tamaño de parcela y pendiente del terreno) afectan de forma significativa a cuestiones de índole económica, pero no son capaces de explicar los desequilibrios alimenticios existentes. Realizando un análisis comparativo entre comunidades que presentaban buenos y malos resultados en cuanto a aporte energético y proteico, se determinó que la seguridad alimentaria estaba relacionada con la sostenibilidad de los sistemas y que concretamente estaba ligada a los atributos de equidad y autonomía. Otro resultado destacable fue que las comunidades más marginales y con mayor dificultad de acceso mostraron mayores niveles de inseguridad alimentaria, pero la variabilidad intergrupal fue muy alta. Eso demuestra que la seguridad alimentaria y nutricional forma parte de un complejo sistema de estrategias de autoabastecimiento ligada a la idiosincrasia misma de cada uno de los hogares. En tercer lugar, se evaluó el desempeño de las escuelas de campo de agricultores (ECAs) en la mejora de la sostenibilidad y la seguridad alimentaria de un sistema campesino de montaña. Para ver el efecto del impacto de estas metodologías a largo plazo, se estudiaron tres comunidades donde se habían implementado ECAs hace 8, 5 y 3 años. Encontramos que el impacto fue progresivo ya que fue la comunidad más antigua la que mejores valores obtuvo. El impacto de las ECAs fue rápido y persistente en los indicadores relacionados con la participación, el acceso a servicios básicos y la conservación de los recursos naturales. El estudio demostró un claro potencial de las ECAs en la mejora general de la sostenibilidad y la seguridad alimentaria de estos sistemas, sin embargo se observó una relación directa entre el aumento de producción agrícola y el uso de insumos externos, lo que puede suponer un punto crítico para los ideales sostenibles. ABSTRACT During the last decades, sustainable agriculture has been the subject of considerable academic interest and debate, not only in conceptual terms, but also in methodological ones. The persistence of high levels of environmental degradation and food insecurity in many regions has led to new initiatives focused on revitalizing peasant agriculture and renewed discussions of the role of sustainable agriculture as an engine for development, environmental conservation and poverty alleviation. Therefore, to assess mountain farming systems, we must consider food dimension and taking into account the specificities of the mountain systems as the foundation of sustainability. When evaluating contribution of technological and management alternative proposals in achieving sustainability and food security for peasant farming systems in Mesoamerican highlands, three research questions arise: • Is sustainability of peasant-farming systems being evaluated taking into account climate variability, participation of farmers and temporal dynamics? • Can we rescue common trends in these systems and extrapolate the results to other areas? • What alternative proposals that have been conducted are unequivocally positives? In this document, we present three evaluations of sustainability that try to highlight the challenges and opportunities that currently face mountain farming systems in Mesoamerica. First, we evaluate the sustainability of three agricultural management systems in two contrasting weather years. We determined that during the first year that exposed heavy rains and moderate temperatures, low-input systems, which are based on the use of organic fertilizers and crop rotation, provided better results in terms of ecological indicators and equal results in terms of economic and social indicators than those achieved using a high chemical input system. In the second year, which featured early frosts and a winter drought, productivity declined in all systems; however, the most diversified systems (in terms of the maize varieties grown and the sowing of other crops) more successfully resisted these climatic adversities. Second, we evaluate the farmers’ perception to determine the key drivers for achieving their sustainability and food and nutritional security. We determined that the key factors identified by farmers (landholding size and slope of cropland) exerted significant impacts on economic disparities but did not explain the malnutrition levels. We compared two contrasting hamlets according to their energy and protein supply, one namely Limón Timoté (LT), which did not present food problems and Limón Peña Blanca (LP), which did exhibit food insecurity. The results showed that FNS is linked to sustainability, and it is primarily related to the sustainability attributes of self-reliance and equity. Although the more marginated and inaccessible community exhibited more food insecurity, food and nutritional security depend upon a complex array of self-sufficiency strategies that remain linked to individual household idiosyncrasies. Third, we evaluated the impact of farmer field schools for improving the sustainability and food security of peasant mountain systems. In order to appreciate the long-term impact, we studied three communities where FFSs were implemented eight, five and three years ago, respectively. We found that FFSs have a gradual impact, as the community that first implemented FFSs scores highest. The impact of FFSs was broad and long-lasting for indicators related to participation, access to basic services and conservation of natural resources. This study demonstrates the potential of FFSs, but more attention will have to be paid to critical indicators in order to scale up their potential in the future. We observed a direct relationship between the increase in agricultural production and the use of external inputs, which is a critical point for sustainable ideals.

Analytical study of the thermal behaviour and stability of a small satellite

In this work the thermal analysis of a small satellite orbiting around the Earth has been approached by direct integration of the heat balance equations of a two-node reduced model, obtaining a linearized second order ODE problem, similar in form to the classical case of the forced vibration of a damped system. As the thermal loads (solar radiation, albedo, etc.) are harmonic, the problem is solved by means of Fourier analysis methods. Research on that field can be directly applied to the analysis of thermal problems and the results obtained are satisfactory. Working on the frequency domain streamlines the analysis, simplifies the study and facilitates the experimental testing. The transfer functions are obtained for the two-node case but the study can be extended to an n-node model.

Discourses and values underpin public debate on fracking in Spain: a case study at the crossroad

In the EU context extraction of shale and oil gas by hydraulic fracturing (fracking) differs from country to country in terms of legislation and implementation. While fossil fuel extraction using this technology is currently taking place in the UK, Germany and France have adopted respective moratoria. In between is the Spanish case, where hydrocarbon extraction projects through fracking have to undergo mandatory and routine environmental assessment in accordance with the last changes to environmental regulations. Nowadays Spain is at the crossroad with respect to the future of this technology. We presume a social conflictt in our country since the position and strategy of the involved and confronted social actors -national, regional and local authorities, energy companies, scientists, NGO and other social organization- are going to play key and likely divergent roles in its industrial implementation and public acceptance. In order to improve knowledge on how to address these controverted situations from the own engineering context, the affiliated units from the Higher Technical School of Mines and Energy Engineering at UPM have been working on a transversal program to teach values and ethics. Over the past seven years, this pioneering experience has shown the usefulness of applying a consequentialist ethics, based on a case-by-case approach and costs-benefits analysis both for action and inaction. As a result of this initiative a theoretical concept has arisen and crystallized in this field: it is named Inter-ethics. This theoretical perspective can be very helpful in complex situations, with multi-stakeholders and plurality of interests, when ethical management requires the interaction between the respective ethics of each group; professional ethics of a single group is not enough. Under this inter-ethics theoretical framework and applying content analysis techniques, this paper explores the articulation of the discourse in favour and against fracking technology and its underlying values as manifested in the Spanish traditional mass media and emerging social media such as Youtube. Results show that Spanish public discourse on fracking technology includes the costs-benefits analysis to communicate how natural resources from local communities may be affected by these facilities due to environmental, health and economic consequences. Furthermore, this technology is represented as a solution to the "demand of energy" according to the optimistic discourse while, from a pessimistic view, fracking is often framed as a source "environmental problems" and even natural disasters as possible earthquakes. In this latter case, this negative representation could have been influenced by the closure of a macro project to store injected natural gas in the Mediterranean Sea using the old facilities of an oil exploitation in Amposta (Proyecto Cástor). The closure of this project was due to the occurrence of earthquakes whose intensity was higher than the originally expected by the experts in the assessment stage of the project.

Odor space and olfactory processing: Collective algorithms and neural implementation

Several basic olfactory tasks must be solved by highly olfactory animals, including background suppression, multiple object separation, mixture separation, and source identification. The large number N of classes of olfactory receptor cells—hundreds or thousands—permits the use of computational strategies and algorithms that would not be effective in a stimulus space of low dimension. A model of the patterns of olfactory receptor responses, based on the broad distribution of olfactory thresholds, is constructed. Representing one odor from the viewpoint of another then allows a common description of the most important basic problems and shows how to solve them when N is large. One possible biological implementation of these algorithms uses action potential timing and adaptation as the “hardware” features that are responsible for effective neural computation.

ZK200775: A phosphonate quinoxalinedione AMPA antagonist for neuroprotection in stroke and trauma

Stroke and head trauma are worldwide public health problems and leading causes of death and disability in humans, yet, no adequate neuroprotective treatment is available for therapy. Glutamate antagonists are considered major drug candidates for neuroprotection in stroke and trauma. However, N-methyl-d-aspartate antagonists failed clinical trials because of unacceptable side effects and short therapeutic time window. α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) antagonists derived from the quinoxalinedione scaffold cannot be used in humans because of their insolubility and resulting renal toxicity. Therefore, achieving water solubility of quinoxalinediones without loss of selectivity and potency profiles becomes a major challenge for medicinal chemistry. One of the major tenets in the chemistry of glutamate antagonists is that the incorporation of phosphonate into the glutamate framework results in preferential N-methyl-d-aspartate antagonism. Therefore, synthesis of phosphonate derivatives of quinoxalinediones was not pursued because of a predicted loss of their selectivity toward AMPA. Here, we report that introduction of a methylphosphonate group into the quinoxalinedione skeleton leaves potency as AMPA antagonists and selectivity for the AMPA receptor unchanged and dramatically improves solubility. One such novel phosphonate quinoxalinedione derivative and competitive AMPA antagonist ZK200775 exhibited a surprisingly long therapeutic time window of >4 h after permanent occlusion of the middle cerebral artery in rats and was devoid of renal toxicity. Furthermore, delayed treatment with ZK200775 commencing 2 h after onset of reperfusion in transient middle cerebral artery occlusion resulted in a dramatic reduction of the infarct size. ZK200775 alleviated also both cortical and hippocampal damage induced by head trauma in the rat. These observations suggest that phosphonate quinoxalinedione-based AMPA antagonists may offer new prospects for treatment of stroke and trauma in humans.

A perspective on early commercial applications of voice-processing technology for telecommunications and aids for the handicapped.

The Colloquium on Human-Machine Communication by Voice highlighted the global technical community's focus on the problems and promise of voice-processing technology, particularly, speech recognition and speech synthesis. Clearly, there are many areas in both the research and development of these technologies that can be advanced significantly. However, it is also true that there are many applications of these technologies that are capable of commercialization now. Early successful commercialization of new technology is vital to ensure continuing interest in its development. This paper addresses efforts to commercialize speech technologies in two markets: telecommunications and aids for the handicapped.

Numerical modeling of electromagnetic coupling phenomena in the vicinities of overhead power transmission lines.

Electromagnetic coupling phenomena between overhead power transmission lines and other nearby structures are inevitable, especially in densely populated areas. The undesired effects resulting from this proximity are manifold and range from the establishment of hazardous potentials to the outbreak of alternate current corrosion phenomena. The study of this class of problems is necessary for ensuring security in the vicinities of the interaction zone and also to preserve the integrity of the equipment and of the devices there present. However, the complete modeling of this type of application requires the three- -dimensional representation of the region of interest and needs specific numerical methods for field computation. In this work, the modeling of problems arising from the flow of electrical currents in the ground (the so-called conductive coupling) will be addressed with the finite element method. Those resulting from the time variation of the electromagnetic fields (the so-called inductive coupling) will be considered as well, and they will be treated with the generalized PEEC (Partial Element Equivalent Circuit) method. More specifically, a special boundary condition on the electric potential is proposed for truncating the computational domain in the finite element analysis of conductive coupling problems, and a complete PEEC formulation for modeling inductive coupling problems is presented. Test configurations of increasing complexities are considered for validating the foregoing approaches. These works aim to provide a contribution to the modeling of this class of problems, which tend to become common with the expansion of power grids.

Trauma Treatment in Forensic Settings: Clinicians' Perspectives, Barriers to Effective Treatment, and Suggestions for Clinical Practice

Between 30% and 90% of the prison population is estimated to have survived traumatic experiences such as sexual, emotional, and physical abuse prior to incarceration (Anonymous, 1999; Fondacaro, Holt, & Powell, 1999; Messina & Grella, 2006; Pollard & Baker, 2000; Veysey, De Cou, & Prescott, 1998). Similarly, information from the Bureau of Justice Statistics (as reported in Warren, 2001) estimated that more than half of the women in state prisons have experienced past physical and sexual abuse. Thus, given the astonishing number of inmates who appear to be victims of some kind of trauma, it seems likely that those who work with these inmates (e.g., prison staff, guards, and treatment providers) will in some way encounter challenges related to the inmates' trauma history. These difficulties may appear in any number of forms including inmates' behavioral outbursts, increased emotionality, sensitivity to triggering situations, and chronic physical or mental health needs (Veysey, et al., 1998). It is also likely that these individuals with trauma histories would benefit greatly from treatment while incarcerated. This treatment could be utilized to minimize symptoms of posttraumatic stress, decrease behavioral problems, and help the inmate function more effectively in society when released from incarceration (Kokorowski & Freng, 2001; Tucker, Cosio, Meshreki, 2003). Few studies have explored the types of trauma treatment that are effective with inmate populations or made specific suggestions for clinicians working in forensic settings (Kokorowski & Freng, 2001). Essentially, there appears to be a large gap in terms of the need for trauma treatment for inmates and the lack of literature addressing what to do about it. However, clinicians across the country seem to be quietly attempting to fulfill this need for trauma treatment with incarcerated populations. They are providing this greatly needed treatment every day. in the face of enormous challenges and often without recognition or the opportunity to share their valuable work with the larger community.

A Meta-Analytic Review of Mindfulness-Based Interventions on Symptom Reduction: A Critique and Guide for Future Investigation.

Over the past decade, mindfulness practices have been used with increasing frequency as therapeutic components within cognitive behavioral treatment regimens. As is standard practice, prescriptive uses of mindfulness intervention are incorporated to improve end-state functioning by ameliorating problematic symptoms and conditions. Common change-targets include the control of cognitive and emotional content for purposes of enhancing psychological self-regulation and physical well-being. The term mindfulness applies to a heterogeneous range of practices, methods, and techniques. While there is no singular agreed upon definition for mindfulness, as a process concept, the term connotes an immediate, non-thetic access to events, wherein each occasioning event is experienced in toto within the broader contextual event-field, and distinct from intervening conceptual themes being noticed. Training in mindfulness practices may be conducted using individual, group, or small class formats. The current paper provides a meta-analytic review of 44 treatment outcome studies (extracted 1982 through 2006), which examines the clinical utility of mindfulness as the primary therapeutic approach. Results indicated that average effect sizes for mindfulness based interventions fell within the medium range for construct category variables examined (d = .56). These findings suggest that mindfulness training is a cost-effective treatment for a wide array of contemporary psychological problems and diagnoses, in addition to fostering positive psychology attributes such as quality and satisfaction with life. A critique of the research and recommendations for future research, including a need to examine the role of mindfulness as a tool for cultivating increased psychological acceptance and life satisfaction, is presented.

The Caregiver–Child Relationship, Youth Mental Health, and Placement Stability in a Child Welfare Sample

Objective: Healthy relationships between adolescents and their caregivers have been robustly associated with better youth outcomes in a variety of domains. Youth in contact with the child welfare system are at higher risk for worse outcomes including mental health problems and home placement instability. A growing body of literature points to youth mental health problems as both a predictor and a consequence of home placement instability in this population; the present study aimed to expand our understanding of these phenomena by examining the interplay among the caregiver-child relationship, youth mental health symptoms, and placement change over time. Method: The sample consisted of 1,179 youths aged 11-16, from the National Survey of Child and Adolescent Well-Being, a nationally representative sample of children in contact with the child welfare system. We used bivariate correlations and autoregressive cross-lagged path analysis to examine how youths’ reports of their externalizing and internalizing symptoms, their relationship with their caregivers, and placement changes reciprocally influenced one another over three time points. Results: In the overall models, early internalizing symptoms significantly negatively predicted the quality of the caregiver-child relationship at the next time point, and early externalizing symptoms predicted subsequent placement change. In addition, later externalizing symptoms negatively predicted subsequent reports of relationship quality, and later placement changes predicted subsequent externalizing problems; these relationships were significant only at the trend level (p < .10). The quality of the relationship was significantly negatively correlated with externalizing and internalizing problems at all time points, and all variables demonstrated autoregressive stability over time. Conclusions: Our findings support the importance of comprehensive interventions for youth in contact with the child welfare system, which target not only youth symptoms in isolation, but also the caregiver-child relationship, as a way to improve social-emotional outcomes in this high-risk population.