Feasibility of Brief Hospital-Based Interventions for Postpartum Depression : Effects on Depressive Symptoms, Perceived Support, & Treatment Utilization

It is estimated that 10-20% of childbearing women develop postpartum depression (PPD), affecting up to 400,000 women in the United States each year. As many an 82% of women diagnosed with PPD decline recommended treatment, primarily due to a lack of knowledge about PPD, to societal stigma and to practical barriers. The objective of this study is to evaluate the feasibility of conducting a large-scale study examining the impact of screening measures and a supportive approach immediately postpartum on utilization of recommended care, levels of depression and perceived social support. Women were randomly assigned (N=40) on a maternity unit to one of four conditions. 1) treatment as usual (control), 2) PPD screening, 3) problem-solving support, and 4) PPD screening and problem-solving support. The three experimental groups also received brief education regarding depression and treatment effectiveness. A post-test at eight weeks postpartum involved a PPD screen, social support questionnaire, life events questionnaire and brief interview to assess utilization of care. An ANCOVA was used to assess whether or not treatment had an effect on screening scores, perceived support and recent life events after controlling for income as a covariate. Results indicated no significant differences between treatment and screen scores, perceived support or recent life events. Positive associations between income and social support scores and negative associations between income and recent life events were observed, suggesting that women of lower socioeconomic status are more likely to experience negative life events and perceive their support as being less adequate. Four women (10%) utilized treatment; of these four, two initiated antidepressants and had a history of treatment for depression. No significant differences were noted between the women who utilized treatment and the overall sample. Denial of treatment was related to fatigue, feeling overwhelmed and beliefs countering treatment. A model supporting the use of a standardized PPD brochure, routine screening immediately postpartum and at early pediatrician visits, prenatal education for both parents, home visits, and the use of a staff psychologist to treat postpartum women in a supportive environment through continuity of care is suggested. In addition, it is suggested that the results of this study be used to generate a second feasibility study utilizing the suggestions provided in this study. The results of a second feasibility study could be used to obtain funding for a large-scale study with adequate power, which could be used to support legislation to fund the proposed model

The Protective Effects of the Violacein Pigment Against UV-C Irradiation in Chromobacterium violaceum

Author Institution: Tippecanoe High School, Tipp City, OHChromobacterium violaceum is a gram-negative bacteria found in tropical regions. C. violaceum has the distinct phenotypic characteristic of a deep violet pigment called violacein. Violacein has a high molar extinction in methanol, suggesting that it is protective against visible light. The purpose of this study was to establish the protective effects of violacein against UV-induced cellular damage. It was hypothesized that violacein protects DNA and proteins (e.g. catalase) from UV-C induced damage. Wild-type (WT) C. violaceum was mutagenized with N-methyl-N’-nitro-N-nitrosoguanidine to produce mutants with varying amounts of violacein. Mutants CV9, CV13, and CV14 (non-pigmented) produced less pigmentation than WT and retained colony morphology, while mutants H19, H20, and H21 (hyper-producers) over-expressed violacein but had an altered petite morphology. UV-induced DNA damage was assayed through sub-culture post-irradiation at 6,000μW*s-1*cm-2 at λ=253.7nm. Sub-cultures of WT and hyper-producers showed reduced viability after 48 hours; nonpigmented mutants showed no growth, suggesting violacein is protective against UV-induced DNA damage. UV-induced catalase damage was assayed pre- and post-irradiation. Catalase activity in WT and hyper-producers significantly decreased post-irradiation; catalase activities of non-pigmented mutants significantly increased post-irradiation. Increased catalase activity in non-pigmented mutants can potentially be explained by the increased induction of catalase genes in response to elevated reactive oxidative species, presumably from lack of pigmentation. Taken together, these results support the hypothesis that violacein is protective against UV-induced cellular damage

A Galerkin boundary element method for high frequency scattering by convex polygons

In this paper we consider the problem of time-harmonic acoustic scattering in two dimensions by convex polygons. Standard boundary or finite element methods for acoustic scattering problems have a computational cost that grows at least linearly as a function of the frequency of the incident wave. Here we present a novel Galerkin boundary element method, which uses an approximation space consisting of the products of plane waves with piecewise polynomials supported on a graded mesh, with smaller elements closer to the corners of the polygon. We prove that the best approximation from the approximation space requires a number of degrees of freedom to achieve a prescribed level of accuracy that grows only logarithmically as a function of the frequency. Numerical results demonstrate the same logarithmic dependence on the frequency for the Galerkin method solution. Our boundary element method is a discretization of a well-known second kind combined-layer-potential integral equation. We provide a proof that this equation and its adjoint are well-posed and equivalent to the boundary value problem in a Sobolev space setting for general Lipschitz domains

A high-wavenumber boundary-element method for an acoustic scattering problem

In this paper we show stability and convergence for a novel Galerkin boundary element method approach to the impedance boundary value problem for the Helmholtz equation in a half-plane with piecewise constant boundary data. This problem models, for example, outdoor sound propagation over inhomogeneous flat terrain. To achieve a good approximation with a relatively low number of degrees of freedom we employ a graded mesh with smaller elements adjacent to discontinuities in impedance, and a special set of basis functions for the Galerkin method so that, on each element, the approximation space consists of polynomials (of degree $\nu$) multiplied by traces of plane waves on the boundary. In the case where the impedance is constant outside an interval $[a,b]$, which only requires the discretization of $[a,b]$, we show theoretically and experimentally that the $L_2$ error in computing the acoustic field on $[a,b]$ is ${\cal O}(\log^{\nu+3/2}|k(b-a)| M^{-(\nu+1)})$, where $M$ is the number of degrees of freedom and $k$ is the wavenumber. This indicates that the proposed method is especially commendable for large intervals or a high wavenumber. In a final section we sketch how the same methodology extends to more general scattering problems

Balancing Compression and Encryption of Satellite Imagery

With the rapid developments in the remote sensing technologies and services, there is a necessity for combined compression and encryption of satellite imagery. The onboard satellite compression is used to minimize storage and communication bandwidth requirements of high data rate satellite applications. While encryption is employed to secure these resources and prevent illegal use of image sensitive information. In this paper, we propose an approach to address these challenges which raised in the highly dynamic satellite based networked environment. This approach combined compression algorithms (Huffman and SPIHT) and encryptions algorithms (RC4, blowfish and AES) into three complementary modes: (1) secure lossless compression, (2) secure lossy compression and (3) secure hybrid compression. The extensive experiments on the 126 satellite images dataset showed that our approach outperforms traditional and state of art approaches by saving approximately (53%) of computational resources. In addition, the interesting feature of this approach is these three options that mimic reality by imposing every time a different approach to deal with the problem of limited computing and communication resources

Simulations of Ductile Fracture in an Idealized Ship Grounding Scenario Using Phenomenological Damage and Cohesive Zone Models

Two complementary simulation methodologies for ductile fracture in large sheet metal components are presented and evaluated in this paper. The first approach is based on the phenomenological dilatational plasticity-damage model developed by Woelke and Abboud [68], which accounts for pressure-dependent volumetric damage growth through a scalar damage variable. The damage function represents phenomenologically micromechanical changes the material undergoes during the process of necking. Secondly, the cohesive zone model with an opening mode traction-separation law is employed to simulate the same ductile fracture problems accounting for significant variation of the multiaxial stress state along the crack path. Both methods are examined as to their capabilities to reproduce and predict the outcome of large scale experimental fracture tests of welded and unwelded ductile plates subjected to large-scale penetration, simulating an idealized ship grounding (Alsos and Amdahl, [1, 2]). The results of the current study indicate that, with appropriate calibration, both approaches can be successfully employed to simulate ductile fracture in structural components under multiaxial stress. The advantages and shortcomings of each approach is discussed from the point of view of post-test numerical investigation as well as its predictive capabilities as an engineering tool.Engineering and Applied Science