34,640 research outputs found
Expanded sun-look angle program
Computer program provides time history of sun aspect angles as seen from spacecraft and generates binary tape containing time history of position, velocity, and body attitude angles of vehicle in local horizontal, local vertical system. Program is written in FORTRAN 5 and SLEUTH 2 for Univac 1108 computer
Review Of Interventions For Parental Depression From Toddlerhood To Adolescence
Because of the recurrent course, significant burden, and intergenerational impact of depression, there is a great need for interventions for depressed parents and their children. This article reviews eight interventions that 1) aim to impact the functioning and well-being of 18-month to 18-year old children of depressed parents and 2) have been evaluated in controlled studies. The interventions are described and the empirical evidence of their efficacy is reviewed and critiqued. Existing research points to several promising intervention strategies, such as psychoeducation about parental depression, addressing parenting in adult depression treatment, promoting positive parent-child interactions, and teaching coping skills to children. Common limitations of the research in this area are small sample sizes, homogenous samples, and lack of replication. Implementation problems within the mental healthcare system are highlighted. Multi-component interventions seem to be a promising approach to address the complex impact parental depression has on children and the parent-child relationship. This review illustrates the need for more research on intervention models that can be implemented with children at various developmental levels
Effects of memory on the shapes of simple outbreak trees
Genomic tools, including phylogenetic trees derived from sequence data, are increasingly used to understand outbreaks of infectious diseases. One challenge is to link phylogenetic trees to patterns of transmission. Particularly in bacteria that cause chronic infections, this inference is affected by variable infectious periods and infectivity over time. It is known that non-exponential infectious periods can have substantial effects on pathogens’ transmission dynamics. Here we ask how this non-Markovian nature of an outbreak process affects the branching trees describing that process, with particular focus on tree shapes. We simulate Crump-Mode-Jagers branching processes and compare different patterns of infectivity over time. We find that memory (non-Markovian-ness) in the process can have a pronounced effect on the shapes of the outbreak’s branching pattern. However, memory also has a pronounced effect on the sizes of the trees, even when the duration of the simulation is fixed. When the sizes of the trees are constrained to a constant value, memory in our processes has little direct effect on tree shapes, but can bias inference of the birth rate from trees. We compare simulated branching trees to phylogenetic trees from an outbreak of tuberculosis in Canada, and discuss the relevance of memory to this dataset
Attachment and abandonment: a study of factors contributing to or hindering the development of trust and functional family behaviour
This research examines the lives of individual children and adults of diverse ages and ethnicities, who suffer common and uncommon abandonment. The study employs a naturalistic “inquiry from the inside” approach and involves intensive participant observation on the part of the researcher. This allows a form of research to emerge that is longitudinal and dialogical. It includes the collection and analysis of the life histories of participants and allows for comparisons and shared experiences. The depth of involvement of the researcher in the participants’ lives, together with analysis of their experiences, combine to form a unique methodological model, generating a deeper and more nuanced understanding than commonly available of how the abandoned person views their world, while moving toward relational connection. Analysis of the life histories, field notes, observations and interviews, in concert with ethnographic field data, yield a progressive pattern of trust and development of relationship. In this process, the language, stages and steps of a non-clinical model of intervention emerges within the life experiences of the individual participants. The resulting paradigm applies most directly to individuals challenged by abandonment, and to their family structure, with the potential application for social agencies (governmental and nongovernmental) and institutional models of care. The research offers two contributions to the field of study addressing the lived experience of formerly abandoned children and their families including: (1) extended understanding of the phenomenon of attachment through a holistic and dynamic approach to the attachment process, involving life history and ethnographic examination and (2) a coherent model of intervention revealing the development from abandonment to relational connection. This includes responses of the participant to availability and empathy, and reveals a progression from survival through vulnerability and trust, to authenticity and relational connection
Model-Independent Determinations of B -> D l nu , D* l nu Form Factors
We present nonperturbative, model-independent parametrizations of the
individual QCD form factors relevant to B -> D* l nu and B -> D l nu decays.
These results follow from dispersion relations and analyticity, without
recourse to heavy quark symmetry. To describe a form factor with two percent
accuracy, three parameters are necessary, one of which is its normalization at
zero recoil, F(1). We combine the individual form factors using heavy quark
symmetry to extract values for the product |V_{cb}| F(1) from B -> D* l nu data
with negligible extrapolation uncertainty.Comment: uses harvmac and epsf, 22 pages, 3 eps figures include
Heavy Meson Masses in the \epsilon-Regime of HM\chi PT
The pseudoscalar and vector heavy meson masses are calculated in the
\epsilon-regime of Heavy Meson Chiral Perturbation Theory to order \epsilon^4.
The results of this calculation will allow the determination of low-energy
coefficients (LECs) directly from Lattice QCD calculations of the heavy mesons
masses for lattices that satisfy the \epsilon-regime criteria. In particular,
the LECs that parametrize the NLO volume dependance of the heavy meson masses
are necessary for evaluating the light pseudoscalar meson (\pi, K, \eta) and
heavy meson ({D^0, D^+, D^+_s}, {B^-,\bar{B}^0,\bar{B}^0_s}) scattering phase
shifts.Comment: 16 pages, 6 figure
Uprated OMS Engine Status-Sea Level Testing Results
The current Space Shuttle Orbital Maneuvering Engine (OME) is pressure fed, utilizing storable propellants. Performance uprating of this engine, through the use of a gas generator driven turbopump to increase operating pressure, is being pursued by the NASA Johnson Space Center (JSC). Component level design, fabrication, and test activities for this engine system have been on-going since 1984. More recently, a complete engine designated the Integrated Component Test Bed (ICTB), was tested at sea level conditions by Aerojet. A description of the test hardware and results of the sea level test program are presented. These results, which include the test condition operating envelope and projected performance at altitude conditions, confirm the capability of the selected Uprated OME (UOME) configuration to meet or exceed performance and operational requirements. Engine flexibility, demonstrated through testing at two different operational mixture ratios, along with a summary of projected Space Shuttle performance enhancements using the UOME, are discussed. Planned future activities, including ICTB tests at simulated altitude conditions, and recommendations for further engine development, are also discussed
A sensitive infrared imaging up converter and spatial coherence of atmospheric propagation
An infrared imaging technique based on the nonlinear interaction known as upconversion was used to obtain images of several astronomical objects in the 10 micrometer spectral region, and to demonstrate quantitatively the sharper images allowed for wavelengths beyond the visible region. The deleterious effects of atmospheric inhomogeneities on telescope resolution were studied in the infrared region using the technique developed. The low quantum efficiency of the device employed severely limited its usefulness as an astronomical detector
LANDSAT Range Resource Information System
A series of test products were developed from LANDSAT data sets for North Central Texas that paralleled the needs of ranchers, technical personnel, and the media. The products and evaluation questionnaires were mailed to approximately 150 ranchers who had reported an interest in evaluating the information systems. In addition to the rancher group, fourteen media people and a thirty-three member group in the agri business/technical community was also chosen to receive test products. The group responses are analyzed. Examples of the test products and associated questionnaires are included
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