5,935 research outputs found
Behavior Problems in Toddlers With and Without Developmental Delays: Comparison of Treatment Outcomes
The purpose of this study is to examine the effectiveness of an in-home parent management program for toddlers with behavior problems and developmental delays by comparing outcomes for a group of toddlers with developmental delays (n = 27) and a group of toddlers without developmental delays (n = 27). The majority of children lived in single parent, low-income homes. Results suggest that the parent management program is equally effective for children with and without developmental delays. Parents from both groups reported clinically significant improvement in their children\u27s behavior and parenting practices. Clinical implications regarding the importance of these findings for improving outcomes for toddlers with behavior problems and developmental delays living in poverty were discussed
Linear Self-Motion Cues Support the Spatial Distribution and Stability of Hippocampal Place Cells
The vestibular system provides a crucial component of place-cell and head-direction cell activity [1-7]. Otolith signals are necessary for head-direction signal stability and associated behavior [8, 9], and the head-direction signal's contribution to parahippocampal spatial representations [10-14] suggests that place cells may also require otolithic information. Here, we demonstrate that self-movement information from the otolith organs is necessary for the development of stable place fields within and across sessions. Place cells in otoconia-deficient tilted mice showed reduced spatial coherence and formed place fields that were located closer to environmental boundaries, relative to those of control mice. These differences reveal an important otolithic contribution to place-cell functioning and provide insight into the cognitive deficits associated with otolith dysfunction
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Towards Understanding the Politics of Flex Crops and Commodities: Implications for Research and Policy Advocacy
This discussion paper offers a preliminary exploration of the concept and phenomenon of “flex crops and commodities”, building on an earlier and initial analysis and abbreviated idea put forward by some of the authors of this paper.
We discuss the dual concepts of the “multiple-ness” and “flexible-ness” of crops and commodities as two distinct but intertwined dimensions of some key crops and commodities.
These key crops and commodities are shaped by the changing global context that is itself (re)moulded in large part by the convergence of multiple crises and the various responses to those crises. Building on these dual concepts, we will identify and explain the minimum requirements for crop and commodity flexing.
We will also try to typologize the various types of crop and commodity flexing, namely, “real flexing”, “anticipated/speculated flexing”, and “imagined flexing”—to allow for a deeper examination of these interrelated processes.
The boundaries between these categories (multiple/flexible, real, anticipated and imagined) are not always clearly demarcated, requiring us to examine the issue of flex crops and commodities in a more interlinked manner.
We will focus our initial exploration on the political dynamics of such interactions and intersections, looking into the factors that encourage or discourage, facilitate or hinder maximization of the “multiple-ness” and/or “flexible-ness” of particular crops and commodities.
Finally, and as a way of closing, we will outline the implications of these dynamics for how we think of engaged research, public actions and policy advocacy, including a brief discussion of what we call “flex policy narratives” by governments and corporations.
Acute Liver Failure Secondary to Hemophagocytic Lymphohistiocytosis during Pregnancy.
Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive immune activation that mimics and occurs with other systemic diseases. A 35-year-old female presented with signs of viral illness at 13 weeks of pregnancy and progressed to acute liver failure (ALF). We discuss the diagnosis of HLH and Kikuchi-Fujimoto (KF) lymphadenitis in the context of pregnancy and ALF. HLH may respond to comorbid disease-specific therapy, and more toxic treatment can be avoided
Vascular Dysfunction and Posttraumatic Stress Disorder: Examining the Role of Oxidative Stress and Sympathetic Activity
Purpose: The physiological manifestations of posttraumatic stress disorder (PTSD) have been associated with an increase in risk of cardiovascular disease (CVD) independent of negative lifestyle factors. The goal of the study was to better elucidate the mechanisms behind the increased CVD risk by examining peripheral vascular function, a precursor to CVD. Moreover, this study sought to determine the role of oxidative stress and sympathetic nervous system (SNS) activity in PTSD-induced vascular dysfunction.
Methods: Sixteen individuals with PTSD (10 women, 6 men; age 24 ± 4 years), and twenty-four healthy controls (CTRL; 15 women, 9 men, 24 ± 4 years), participated in the study. The PTSD group participated in two visits, consuming either a placebo or antioxidant cocktail (AO - vitamins C and E and alpha lipoic acid) prior to their visits, in a randomized order. Arm vascular function was assessed via the reactive hyperemia- induced flow mediated dilation of the brachial artery (BAFMD) technique and evaluated with Doppler ultrasonography. Brachial artery and arm microvascular function were determined by percent change of diameter from baseline normalized for BA shear rate (BAD/Shear), and blood flow area under the curve (BF AUC), respectively. Heart rate variability (HRV) was used to assess autonomic nervous system activity.
Results: BF AUC was significantly lower (p = 0.02) and SNS activity was significantly higher (p = 0.02) in the PTSD group when compared to the CTRL group. BAD/Shear was not different between groups. Following the acute AO supplementation, BF AUC was augmented to which it was no longer significantly different (p = 0.16) when compared to the CTRL group. SNS activity within the PTSD group was significantly reduced (p=.007) following the AO supplementation when compared to the PL condition, and the difference between PTSD and CTRL was no longer significant (p=.41).
Conclusion: Young individuals with PTSD demonstrated lower arm microvascular, but not brachial artery, function as well as higher sympathetic activity when compared to healthy controls matched for age, sex, and physical activity level. Furthermore, this microvascular dysfunction and SNS activity was attenuated by an acute AO supplementation to the level of the healthy controls. Taken together, this study revealed that the modulation of oxidative stress, via an acute AO supplementation, improved vascular dysfunction in individuals with PTSD, potentially by reducing the substantial SNS activity associated with this disorder.https://scholarscompass.vcu.edu/gradposters/1084/thumbnail.jp
One-sided smoothness-increasing accuracy-conserving filtering for enhanced streamline integration through discontinuous fields
The discontinuous Galerkin (DG) method continues to maintain heightened levels
of interest within the simulation community because of the discretization flexibility it
provides. One of the fundamental properties of the DG methodology and arguably its most
powerful property is the ability to combine high-order discretizations on an inter-element
level while allowing discontinuities between elements. This flexibility, however, generates
a plethora of difficulties when one attempts to use DG fields for feature extraction and visualization,
as most post-processing schemes are not designed for handling explicitly discontinuous
fields. This work introduces a new method of applying smoothness-increasing,
accuracy-conserving filtering on discontinuous Galerkin vector fields for the purpose of enhancing
streamline integration. The filtering discussed in this paper enhances the smoothness
of the field and eliminates the discontinuity between elements, thus resulting in more
accurate streamlines. Furthermore, as a means of minimizing the computational cost of the
method, the filtering is done in a one-dimensional manner along the streamline.United States. Army Research Office (Grant no. W911NF-05-1-0395)National Science Foundation (U.S.) (Career Award NSF-CCF0347791
Multi-dimensional filtering: Reducing the dimension through rotation
Over the past few decades there has been a strong effort towards the development of Smoothness-Increasing Accuracy-Conserving (SIAC) filters for Discontinuous Galerkin (DG) methods, designed to increase the smoothness and improve the convergence rate of the DG solution through this post-processor. These advantages can be exploited during flow visualization, for example by applying the SIAC filter to the DG data before streamline computations [Steffan et al., IEEE-TVCG 14(3): 680-692]. However, introducing these filters in engineering applications can be challenging since a tensor product filter grows in support size as the field dimension increases, becoming computationally expensive. As an alternative, [Walfisch et al., JOMP 38(2);164-184] proposed a univariate filter implemented along the streamline curves. Until now, this technique remained a numerical experiment. In this paper we introduce the line SIAC filter and explore how the orientation, structure and filter size affect the order of accuracy and global errors. We present theoretical error estimates showing how line filtering preserves the properties of traditional tensor product filtering, including smoothness and improvement in the convergence rate. Furthermore, numerical experiments are included, exhibiting how these filters achieve the same accuracy at significantly lower computational costs, becoming an attractive tool for the scientific visualization community
Microbial Biofilm Community Variation in Flowing Habitats: Potential Utility as Bioindicators of Postmortem Submersion Intervals
Biofilms are a ubiquitous formation of microbial communities found on surfaces in aqueous environments. These structures have been investigated as biomonitoring indicators for stream heath, and here were used for the potential use in forensic sciences. Biofilm successional development has been proposed as a method to determine the postmortem submersion interval (PMSI) of remains because there are no standard methods for estimating the PMSI and biofilms are ubiquitous in aquatic habitats. We sought to compare the development of epinecrotic (biofilms on Sus scrofa domesticus carcasses) and epilithic (biofilms on unglazed ceramic tiles) communities in two small streams using bacterial automated ribosomal intergenic spacer analysis. Epinecrotic communities were significantly different from epilithic communities even though environmental factors associated with each stream location also had a significant influence on biofilm structure. All communities at both locations exhibited significant succession suggesting that changing communities throughout time is a general characteristic of stream biofilm communities. The implications resulting from this work are that epinecrotic communities have distinctive shifts at the first and second weeks, and therefore the potential to be used in forensic applications by associating successional changes with submersion time to estimate a PMSI. The influence of environmental factors, however, indicates the lack of a successional pattern with the same organisms and a focus on functional diversity may be more applicable in a forensic context
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