School Standpoint\u27: Understanding Effects of Personal Experiences within School-Based Social Work Practice

This qualitative, phenomenological study used Standpoint Theory combined with Positionality theories as a lens to understand the data and an analytical tool to determine how school-based social workers consider their general \u27sense of self\u27 within their professional decisions and practice approaches. Findings included three main themes that emerged from the data regarding participants\u27 overall \u27sense of self\u27 within school-based social work practices: social structure, personal identity, and professional role. Participants described these influences in fluid, flexible, and dynamic ways, and as having both positive and negative impact on their professional practices. These three components of school-based social work practice came together to form a conceptual term and accompanying model (\u27School Standpoint\u27 Model). The findings in this study have implications for: advancing pre-service training for social workers in schools, improving current practice approaches through use of cultural humility, and show necessity to enhance educational policy in relation to school-based social workers\u27 job roles and responsibilities

Fluorescence assay of glucosylceramide glucosidase using NBD‐Cerebroside

A sensitive fluorometric assay for glucocerebroside β‐glucosidase [Dinur, T., Grabowski, G.A., Desnick, R.J., and Gatt, S. (1984)Anal. Biochem. 136, 223–234] has been reexamined. It was found that the lipids containing the NBD moiety (12‐[N‐methyl‐N‐(7‐nitrobenz‐2‐oxa‐1,3‐diazol‐4‐yl)] used for standardization of the assay are light‐sensitive and that the yield of fluorescent light is very sensitive to the composition of the solvent used in the fluorometric measurement. Some protection against fading could be obtained by adding a free‐radical trapping agent, Slow Fade. The fading of the free NBD‐acid, when used for standardization, could be prevented by adding ethanol to the solvent, but this reduced the fluorescence yield. It is recommended that some of the fluorescent substrate be enzymatically hydrolyzed completely to NBD‐ceramide, which can be utilized as the standard without the need to add ethanol. A warning about enzyme reaction rate stability with time is given, with a suggestion for ensuring constancy of activity.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141148/1/lipd1052.pd

Using Direct Sequence Spread Spectrum to Determine the Responsiveness of a TCP Aggregate to Packet Drops

In this paper we introduce a test through which the responsiveness of a TCP aggregate can be measured. The first introduced test is based on dropping a few packets from the aggregate and measuring the resulting rate decrease of that aggregate. This kind of test is not robust to multiple simultaneous tests performed at different routers. Extensions are done to make the test robust to multiple simultaneous tests by inspiring from the CDMA approach in the literature of multiple access channels in communication theory. The measurements of responsiveness can be utilized for different purposes like congestion control or mitigating a Distributed Denial of Service Attack

Lifetime Maximizing Adaptive Traffic Distribution and Power Control in Wireless Sensor Networks

In this paper we study how to maximize the lifetime of randomly deployed wireless sensor networks by applying adaptive traffic distribution and power control. We model this problem as a linear program by abstracting the network into multiple layers. First we focus on the scenario where transmission energy consumption plays the dominant role in overall energy consumption. After ignoring the processing energy consumption, we observe that: in order to maximally extend the lifetime, each node should split its traffic into two portions, and send one portion directly to the sink, and the other one to its neighbor in the next inner layer. Next we consider the effect of incorporating the processing energy consumption. In this case, we have similar observation: for each packet to be sent, the sender should either transmit it using the transmission range with the highest energy efficiency per bit per meter, or transmit it directly to the sink. Besides studying the upper bound of maximum achievable lifetime extension, we discuss some practical issues, such as how to handle the signal interference caused by adaptive power control. Finally, we propose a fully distributed algorithm to adaptively split traffic and adjust transmission power for randomly deployed wireless sensor networks. We also provide extensive simulation results which demonstrat that the network lifetime can be dramatically extended by applying the proposed approach in various scenarios

Lifetime Maximizing Adaptive Power Control in Wireless Sensor Networks

Network lifetime is one of the most critical performance measures for wireless sensor networks. Various schemes have been proposed to maximize the network lifetime. In this paper we consider the lifetime maximization problem via a new approach: adaptive power control. We focus on the sensor networks that consists of a sink and a set of homogeneous wireless sensor nodes, which are randomly deployed according to a uniform distribution. Each node has the same initial energy and the same data generation rate. We formally analyze the lifetime maximizing adaptive power control problem by dividing the network into different layers and then modelling it as a linear programming problem, where the goal is to find an optimal way to adjust the transmission power and split the traffic such that the maximum energy consumption speed among all layers is minimized, and therefore the network lifetime is maximized. One surprising observation from the numerical results is that when every node can reach the sink directly, the optimal solution for each node is to send traffic either to its next inner layer or to the sink directly. This observation has also been justified by the theoretical analysis. The numerical results also show that the lifetime elongation can still be significant even when only those nodes in the innermost few layers are allowed to adaptively adjust their transmission power. We then propose a fully distributed algorithm, the Energy-Aware Push Algorithm (EAPA), and show through simulation that it can dramatically extend the network lifetime

Design Optimization of Multi-Sink Sensor Networks by Analogy to Electrostatic Theory

In this work we introduce a new mathematical tool for optimization of routes, and topology design in wireless sensor networks. We introduce a vector field formulation that models communication in the network, and routing is performed in the direction of this vector field at every location of the network. The magnitude of the vector field at every location represents the density of amount of data that is being transited through that location. We define the total communication cost in the network as the integral of a quadratic form of the vector field over the network area. Our mathematical machinery is based on partial differential equations analogous to the Maxwell equations in electrostatic theory. We use our vector field model to solve the optimization problem for the case in which there are multiple destinations (sinks) in the network. In order to optimally determine the destination for each sensor, we partition the network into areas, each corresponding to one of the destinations. We define a vector field, which is conservative, and hence it can be written as the gradient of a scalar function (also known as a potential function). Then we show that in the optimal assignment of the communication load of the network to the destinations, the value of that potential function should be equal at the locations of all the destinations. Also, we show that such an optimal partitioning of the network load among the destination is unique, and we give iterations to find the optimal solution

Interesting Examples of IBGP Configuration

In this paper we give examples to show that if an Internal Border Gateway Protocol (IBGP) configuration using route reflections violates even one of the four conditions mentioned in the theorem given in a previous work, then there may be persistent oscillations or forwarding loops

Enzymatic fluorometric assay for myo-inositol trisphosphate

The determination of myo-inositol trisphosphate by an enzymatic fluorometric assay is presented. The method involves the acid extraction of water-soluble inositol polyphosphates followed by separation by anion-exchange chromatography. Samples are subsequently neutralized by passage over a Dowex Cl- resin and elution with lithium chloride. Samples are then desalted with ethanol. Following dephosphorylation with alkaline phosphatase, free myo-inositol is measured enzymatically via the NAD-dependent oxidation to scyllo-inosose with myo-inositol dehydrogenase. The efficiency of recovery, assay specificity, and an application to the measurement of inositol polyphosphates in hormone-stimulated tissue are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26721/1/0000271.pd

The phosphatidylinositol synthase of proximal tubule cells

Phosphatidylinositol (PI) is a precursor for an important class of phospholipids, the phosphatidylinositol polyphosphates. Because renal myo-inositol levels may vary under both physiological (e.g., antidiuretic) and pathophysiological (e.g., diabetic) conditions, the formation of PI from CDP-diacylglyceroI (CDP-DG) and myo-inositol via phosphatidylinositol synthase and the regulation of this enzyme have important implications for the cellular biology of renal epithelia. We sought to understand the role of PI synthase by determining its subcellular localization, kinetic properties and regulation in rabbit proximal tubule cells. Proximal tubule cells were isolated from New Zealand White rabbits. The subcellular synthesis of PI was assessed by [32P]orthophosphate labelling with subsequent subcellular fractionation. Labelling of PI was time-dependent and consistent with the rapid incorporation of 32PO4 into basolateral, brush-border, microsomal and nuclear fractions. Pulse-chase labelling of proximal tubule cells was consistent with the formation of PI in microsomal fraction of the proximal tubule cells in addition to both brush-border and basolateral membranes. Conversely, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol displayed radiolabelling patterns consistent with microsomal synthesis alone. The in situ formation of phosphatidylinositol was substantiated by the direct measurement of phosphatidylinositol synthase activity in basolateral, brush-border and microsomal fractions. The apparent Km values for myo-inositol were 0.32 +/- 0.19, 0.39 +/- 0.21 and 0.23 +/- 0.05 mM, and for CDP-DG were 0.12 +/- 0.02, 0.14 +/- 0.05 and 0.12 +/- 0.02 mM in basolateral, brush-border and microsomal fractions, respectively. Vmax values for phosphatidylinositol formation were slightly, but not significantly greater, in microsomal than for plasma membrane fractions. Moreover, based on enzymatic enrichment data, plasma membrane PI synthase activity could not be explained by microsomal cross-contamination alone. PI synthase activity was inhibited by co-incubation with PI without differences among the cellular fractions. Intracellular myo-inositol concentration in the proximal tubule cells as measured by gas-liquid chromatography was 20.5 mM, significantly greater than the apparent Km values for myo-inositol. In conclusion, the in situ synthesis of phosphatidylinositol occurs in several membrane fractions; the kinetic properties of phosphatidylinositol synthase appear to be similar in each fraction; and phosphatidylinositol synthase in proximal tubule cells is inhibited by its own formation product. These data suggest that myo-inositol concentration alone is unlikely to be an important regulator of the chemical mass of phosphatidylinositol at the levels of this polyol observed in rabbit kidney.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28582/1/0000389.pd

Using POMDP as Modeling Framework for Network Fault Management

For highדּpeed networks, it is important that fault management be proactive--i.e., detect, diagnose, and mitigate problems before they result in severe degradation of network performance. Proactive fault manageשּׂent depends on monitoring the network to obtain the data on which to base manager decisions. However, monitoring introduces additional overhead that may itself degrade network performance especially when the network is in a stressed state. Thus, a tradeoff must be made be﫠tween the amount of data collected and transferred on one hand, and the speed and accuracy of fault detection and diagnosis on the other hand. Such a tradeoff can be naturally formulated as a Partially Observable Markov decision process (POMDP).Since exact solution of POMDPs for a realistic number of states is computationally prohibitive, we develop a reinforcementשּׁearningﬢased fast algorithm which learns the decisionגּule in an approximate network simulator and makes it fast deployable to the real network. Simulation results are given to diagnose a switch fault in an ATM network. This approach can be applied to centralized fault management or to construct intelligent agents for distributed fault management