Compressible Media for Water Treatment

Tertiary water treatment is used to remove total suspended solids (TSS) from wastewater. Suez uses compressible media for their tertiary water treatment. There have been supplier issues in the past such as unreliability, long lead-times, unknown manufacturing process, and chances of resale. The chance of resale is an important issue because the specifications may change from one supplier to another. The group was tasked to characterize different types of compressible media for water treatment, design a lab scale filtration unit, and design and manufacture a new media to be tested. In order to gain an operational expenditure advantage, Suez accomplishes media compression without the use of a mechanical device, which was taken into account when designing the filtration unit. The media characterization determined that the media’s fiber was crimped polyethylene terephthalate and the node was atactic polystyrene. The original media was tested on the lab scale filtration unit at concentrations of 10, 30, and 50 mg TSS/L. Due to the size of PVC column diameter (3 inches), channeling and wall-effects were observed, which allowed solids to pass through the media. Because of these effects, the 10 mg TSS/L run was the only acceptable test in terms of turbidity requirements (\u3c2 NTU). New media was designed and manufactured using uncrimped polyethylene terephthalate and hot melt adhesive. The team has future plans to test the new media on the filtration unit. It is expected that the media will be less successful because the fibers are uncrimped.https://scholarscompass.vcu.edu/capstone/1156/thumbnail.jp

In-plane magnetoelectric response in bilayer graphene

A graphene bilayer shows an unusual magnetoelectric response whose magnitude is controlled by the valley-isospin density, making it possible to link magnetoelectric behavior to valleytronics. Complementary to previous studies, we consider the effect of static homogeneous electric and magnetic fields that are oriented parallel to the bilayer's plane. Starting from a tight-binding description and using quasi-degenerate perturbation theory, the low-energy Hamiltonian is derived including all relevant magnetoelectric terms whose prefactors are expressed in terms of tight-binding parameters. We confirm the existence of an expected axion-type pseudoscalar term, which turns out to have the same sign and about twice the magnitude of the previously obtained out-of-plane counterpart. Additionally, small anisotropic corrections to the magnetoelectric tensor are found that are fundamentally related to the skew interlayer hopping parameter $\gamma_4$. We discuss possible ways to identify magnetoelectric effects by distinctive features in the optical conductivity.Comment: 14 pages, 7 figure

The role of maternal emotional availability and attachment in child emotion regulation

Emotions are an essential aspect of human life. They help us to evaluate the importance of an event, to act quickly in a variety of situations, and to communicate with others in social interactions. However, the intensity or duration of emotional responses may not always be adaptive in a given situation or social context. Thus, the ability to regulate emotions is crucial for ones’ well-being, mental health, and socio-emotional functioning. A vast body of literature has emphasized the role of the social environment in children’s development of emotion regulation. Theoretical accounts have emphasized the significance of experiences within caregiving relationships that contribute considerably to the development of (mal-) adaptive emotion regulation (Cassidy, 1994; Kopp, 1989; Sroufe, 1996a). The current thesis focused on attachment security (Ainsworth et al., 1974; Bowlby, 1969/82; Cassidy, 1994) and maternal emotional availability (Biringen, 2008; Biringen et al., 2014) as two key aspects of caregiver–child relationship quality that support children’s development of adaptive emotion regulation. Despite a large body of research on child emotion regulation, not all stages of emotion regulation have been addressed equally in young children. The stage of attentional regulation is particularly interesting as attentional distraction is one of the earliest regulation strategies that emerge. Yet, only few studies have investigated young children’s attentional regulation in response to facial expressions. Furthermore, the stage of behavioral regulation is particularly important in difficult social interactions with others. However, young children’s behavioral regulation in frustrating situations has so far not been researched in cooperative interactions with others. Considering the importance of the domain of emotional development for later developmental outcomes, the current thesis focused on the role of attachment and maternal emotional availability for young children’s attentional and behavioral regulation. For that purpose, three studies were conducted, focusing on two age groups, that is, preschool and toddler period. The first study investigated the relation of attachment security and attentional regulation in preschoolers. In particular, the study examined the relation between preschoolers’ attachment security and their visual attention to facial emotional expressions. To this end, 5-year-olds’ generalized attachment representations and their attention duration to pictures of negative and positive facial expressions were assessed. Results revealed that secure attachment was related to prolonged attention to fearful, sad, and neutral facial expressions. The study supports the notion that attachment security plays a significant role in young children’s attention to emotional information. The second study investigated the relation of maternal emotional availability and attentional regulation in toddlers. In particular, the study examined the reciprocal relations of maternal sensitivity and non-intrusiveness and children’s visual attention to emotional facial expressions. To this end, mothers’ behavior was observed in play interactions and children’s attention to negative and positive facial expressions were assessed at 12 and 24 months. Cross-lagged panel analyses revealed that more sensitive behavior at 12 months predicted prolonged attention to sad and happy expressions at 24 months, while less intrusive caregiving at 12 months predicted prolonged attention to sad expressions at 24 months. Concurrent maternal emotional availability had no effect on toddlers’ attentional regulation. The study supports the notion that maternal sensitive behavior plays a significant role in young children’s attention to emotional information. The third study investigated the relation of maternal emotional availability and behavioral regulation in toddlers. In particular, the study examined whether maternal sensitivity and non-intrusiveness contribute to children’s behavior in difficult cooperative interactions beyond child cognitive skills and temperament. To this end, mothers’ sensitivity and non-intrusiveness were observed in play interactions and children’s behavior to interruptions in two difficult cooperative interactions was assessed at 24 months. Results revealed that maternal intrusiveness was related to child disengagement from the task and approach to the mother. Yet, active help seeking was predicted only by toddler cognitive skills, while reengagement of the experimenter was predicted neither by maternal nor by child characteristics. The study supports the notion that maternal behavior plays a significant role in young children’s use of specific behavioral strategies in frustrating situations. Overall, the current thesis supports specific relations of caregiver–child relationship aspects and young children’s attentional and behavioral regulation. In the preschool period and the toddler period, attachment security (Study 1) and maternal emotional availability (Study 2) are related to children’s attention to emotional facial expressions. Yet, effects are more pronounced in relation to negative emotions and for influences of attachment security and sensitivity. Furthermore, in the toddler period, dimensions of maternal emotional availability contribute differently to the development of attentional and behavioral regulation strategies. While sensitive caregiving is an important factor in toddlers’ attention to positive and negative emotions, intrusive caregiving plays a crucial role for toddlers’ attentional avoidance of negative emotions and for their behavioral disengagement form difficult interactions. In conclusion, the current thesis contributes to a better understanding of the role of caregiver–child relationship quality in young children’s emotion regulation and provides implications for research on child socioemotional development

Weak (anti)localization in tubular semiconductor nanowires with spin-orbit coupling

We compute analytically the weak (anti)localization correction to the Drude conductivity for electrons in tubular semiconductor systems of zinc blende type. We include linear Rashba and Dresselhaus spin-orbit coupling (SOC) and compare wires of standard growth directions $\langle100\rangle$, $\langle111\rangle$, and $\langle110\rangle$. The motion on the quasi-two-dimensional surface is considered diffusive in both directions: transversal as well as along the cylinder axis. It is shown that Dresselhaus and Rashba SOC similarly affect the spin relaxation rates. For the $\langle110\rangle$ growth direction, the long-lived spin states are of helical nature. We detect a crossover from weak localization to weak anti-localization depending on spin-orbit coupling strength as well as dephasing and scattering rate. The theory is fitted to experimental data of an undoped $\langle111\rangle$ InAs nanowire device which exhibits a top-gate-controlled crossover from positive to negative magnetoconductivity. Thereby, we extract transport parameters where we quantify the distinct types of SOC individually.Comment: 17 pages, 9 figure

Surface clustering of metabotropic glutamate receptor 1 induced by long Homer proteins

BACKGROUND: Metabotropic glutamate receptors (mGluRs) regulate neuronal excitability and synaptic strength. The group I mGluRs, mGluR1 and 5, are widespread in the brain and localize to post-synaptic sites. The Homer protein family regulates group I mGluR function and distribution. Constitutively expressed 'long' Homer proteins (Homer 1b, 1c, 2 and 3) induce dendritic localization of group I mGluRs and receptor clustering, either internally or on the plasma membrane. Short Homer proteins (Homer 1a, Ania-3) exhibit regulated expression and act as dominant negatives, producing effects on mGluR distribution and function that oppose those of the long Homer proteins. There remains some controversy over whether long Homer proteins induce receptor internalization by inducing retention in the endoplasmic reticulum, or induce mGluR clustering on the plasma membrane. Further, an exhaustive study of the effects of each long Homer isoform on mGluR distribution has not been published. RESULTS: The distribution of a GFP-tagged group I mGluR, mGluR1-GFP, was examined in the absence of Homer proteins and in the presence of several Homer isoforms expressed in sympathetic neurons from the rat superior cervical ganglion (SCG) using total internal reflection fluorescence (TIRF-M) and confocal microscopy. Quantitative analysis of mGluR1-GFP fluorescence using TIRF-M revealed that expression of each long Homer isoform tested (Homer 1b, 1c, 2b and 3) induced a significant degree of surface clustering. Using confocal imaging, Homer-induced mGluR clusters were observed intra-cellularly as well as on the plasma membrane. Further, in approximately 40% of neurons co-expressing mGluR1-GFP and Homer 1b, intracellular inclusions were observed, but plasma membrane clusters were also documented in some Homer 1b coexpressing cells. CONCLUSION: All long Homer proteins examined (Homer 1b, 1c, 2b and 3) induced a significant degree of mGluR1-GFP clustering on the plasma membrane compared to cells expressing mGluR1-GFP alone. Clusters induced by long Homers appeared on the plasma membrane and intracellularly, suggesting that clusters form prior to plasma membrane insertion and/or persist after internalization. Finally, while Homer 1b induced surface clustering of mGluR1 in some cells, under some conditions intracellular retention may occur

Cетевой мониторинг программного обеспечения в информационной инфраструктуре предприятия

The article is devoted to network monitoring software enterprises. The process of providing functional and technical state of the system are described the actual business needs of the company. The paper proposes a solution to the optimization of this process, based on the scope of activities of the enterprise

A role for Seven in Absentia Homolog (Siah1a) in metabotropic glutamate receptor signaling

BACKGROUND: The mammalian homologue of Seven in Absentia (Siah) can act in the ubiquitin/proteasome pathway. Recent work has shown that Siah can bind group I metabotropic glutamate receptors (mGluRs), but the functional consequences of this interaction are unknown. RESULTS: The effects of coexpression of Siah on group I mGluR signaling were examined using heterologous expression in rat sympathetic, superior cervical ganglion neurons. Siah1a attenuated heterologously expressed group I mGluR-mediated calcium current inhibition, but was without effect on group II mGluR- or NE-mediated calcium current modulation via heterologously expressed mGluR2 or native a2 adrenergic receptors, respectively, indicating that the effect of Siah was specific for group I mGluRs. Surface expression and subcellular distribution of group I mGluRs were not detectably altered in the presence of Siah1a as assessed by immunoflourescence experiments with epitope tagged receptors and imaging of a GFP/mGluR fusion construct. In addition, an N-terminal Siah deletion construct, which cannot function in the proteolysis pathway, displayed effects similar to the wild type Siah1a. Finally, coexpression of calmodulin, which competes with Siah1a for binding to the C-terminal tail of group I mGluRs, reversed the effect of Siah1a on mGluR-mediated signaling. CONCLUSIONS: These data supported the conclusion that the attenuation of mGluR signaling induced by Siah1a expression was likely a direct consequence of Siah/mGluR association rather than a result of targeting of the receptors to the proteosome. In addition, the data suggest that the binding of CaM and Siah may play an important role in the regulation of group I mGluR function