13,177 research outputs found
Posttraumatic Stress and Parenting Behaviors: The Mediating Role of Emotion Regulation
Maternal trauma has been linked with problematic parenting, including both harsh and permissive behaviors. However, little is known about mechanisms accounting for this association. The current study examined the potential impact of posttraumatic stress disorder (PTSD) and emotion regulation on dysfunctional parenting behaviors in a sample of community mothers. We hypothesized a mediation model wherein PTSD would be associated with dysfunctional parenting (i.e., lax and overreactive behaviors) indirectly through deficits in maternal emotion regulation. Seventy-eight community mothers of 18- to 36-month-old children were administered the Clinician Administered PTSD Scale for DSM-5 (CAPS-5) and 19 mothers met criteria for PTSD. Mothers also completed self-report measures of difficulties with emotion regulation and maternal laxness and overreactivity in parenting. Results revealed that emotion dysregulation fully mediated relations between PTSD status and lax (but not overreactive) parenting behaviors. Compared to mothers without PTSD, those with PTSD reported greater lax parenting behaviors indirectly through greater emotion dysregulation. Mothers with PTSD may struggle to parent assertively when trauma symptoms interfere with emotion regulation abilities. The current study highlights the need to design interventions focused on helping trauma-exposed mothers manage distress, ultimately aiming to enhance parenting effectiveness and improve child outcomes
Study of an engine flow diverter system for a large scale ejector powered aircraft model
Requirements were established for a conceptual design study to analyze and design an engine flow diverter system and to include accommodations for an ejector system in an existing 3/4 scale fighter model equipped with YJ-79 engines. Model constraints were identified and cost-effective limited modification was proposed to accept the ejectors, ducting and flow diverter valves. Complete system performance was calculated and a versatile computer program capable of analyzing any ejector system was developed
On the exactness of the Semi-Classical Approximation for Non-Relativistic One Dimensional Propagators
For one dimensional non-relativistic quantum mechanical problems, we
investigate the conditions for all the position dependence of the propagator to
be in its phase, that is, the semi-classical approximation to be exact. For
velocity independent potentials we find that:
(i) the potential must be quadratic in space, but can have arbitrary time
dependence.
(ii) the phase may be made proportional to the classical action, and the
magnitude (``fluctuation factor'') can also be found from the classical
solution.
(iii) for the driven harmonic oscillator the fluctuation factor is
independent of the driving term.Comment: 7 pages, latex, no figures, published in journal of physics
Uncertainties of predictions from parton distribution functions II: the Hessian method
We develop a general method to quantify the uncertainties of parton
distribution functions and their physical predictions, with emphasis on
incorporating all relevant experimental constraints. The method uses the
Hessian formalism to study an effective chi-squared function that quantifies
the fit between theory and experiment. Key ingredients are a recently developed
iterative procedure to calculate the Hessian matrix in the difficult global
analysis environment, and the use of parameters defined as components along
appropriately normalized eigenvectors. The result is a set of 2d Eigenvector
Basis parton distributions (where d=16 is the number of parton parameters) from
which the uncertainty on any physical quantity due to the uncertainty in parton
distributions can be calculated. We illustrate the method by applying it to
calculate uncertainties of gluon and quark distribution functions, W boson
rapidity distributions, and the correlation between W and Z production cross
sections.Comment: 30 pages, Latex. Reference added. Normalization of Hessian matrix
changed to HEP standar
Synthesis, Structure and Properties of Tetragonal Sr2M3As2O2 (M3 = Mn3, Mn2Cu and MnZn2) Compounds Containing Alternating CuO2-Type and FeAs-Type Layers
Polycrystalline samples of Sr2Mn2CuAs2O2, Sr2Mn3As2O2, and Sr2Zn2MnAs2O2 were
synthesized. Their temperature- and applied magnetic field-dependent
structural, transport, thermal, and magnetic properties were characterized by
means of x-ray and neutron diffraction, electrical resistivity rho, heat
capacity, magnetization and magnetic susceptibility measurements. These
compounds have a body-centered-tetragonal crystal structure (space group
I4/mmm) that consists of MO2 (M = Zn and/or Mn) oxide layers similar to the
CuO2 layers in high superconducting transition temperature Tc cuprate
superconductors, and intermetallic MAs (M = Cu and/or Mn) layers similar to the
FeAs layers in high-Tc pnictides. These two types of layers alternate along the
crystallographic c-axis and are separated by Sr atoms. The site occupancies of
Mn, Cu and Zn were studied using Rietveld refinements of x-ray and neutron
powder diffraction data. The temperature dependences of rho suggest metallic
character for Sr2Mn2CuAs2O2 and semiconducting character for Sr2Mn3As2O2 and
Sr2Zn2MnAs2O2. Sr2Mn2CuAs2O2 is inferred to be a ferrimagnet with a Curie
temperature TC = 95(1) K. Remarkably, we find that the magnetic ground state
structure changes from a G-type antiferromagnetic structure in Sr2Mn3As2O2 to
an A-type ferrimagnetic structure in Sr2Mn2CuAs2O2 in which the Mn ions in each
layer are ferromagnetically aligned, but are antiferromagnetically aligned
between layers.Comment: 18 pages, 16 figures, 6 tables; submitted to Phys. Rev.
An alternative to killing? Treatment of reservoir hosts to control a vector and pathogen in a susceptible species
Parasite-mediated apparent competition occurs when one species affects another through the action of a shared parasite. One way of controlling the parasite in the more susceptible host is to manage the reservoir host. Culling can cause issues in terms of ethics and biodiversity impacts, therefore we ask: can treating, as compared to culling, a wildlife host protect a target species from the shared parasite? We used Susceptible Infected Recovered (SIR) models parameterized for the tick-borne louping ill virus (LIV) system. Deer are the key hosts of the vector (Ixodes ricinus) that transmits LIV to red grouse Lagopus lagopus scoticus, causing high mortality. The model was run under scenarios of varying acaricide efficacy and deer densities. The model predicted that treating deer can increase grouse density through controlling ticks and LIV, if acaricide efficacies are high and deer densities low. Comparing deer treated with 70% acaricide efficacy with a 70% cull rate suggested that treatment may be more effective than culling if initial deer densities are high. Our results will help inform tick control policies, optimize the targeting of control methods and identify conditions where host management is most likely to succeed. Our approach is applicable to other host-vector-pathogen systems
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