3,272 research outputs found
Impact of membrane bistability on dynamical response of neuronal populations
Neurons in many brain areas can develop pronounced depolarized state of
membrane potential (up state) in addition to the normal hyperpolarized down
state near the resting potential. The influence of the up state on signal
encoding, however, is not well investigated. Here we construct a
one-dimensional bistable neuron model and calculate the linear response to
noisy oscillatory inputs analytically. We find that with the appearance of an
up state, the transmission function is enhanced by the emergence of a local
maximum at some optimal frequency and the phase lag relative to the input
signal is reduced. We characterize the dependence of the enhancement of
frequency response on intrinsic dynamics and on the occupancy of the up state
Relation between Plasma Process-Induced Oxide Failure Fraction and Antenna Ratio
Conventional antenna charging theory predicts that the net current drawn from plasma is proportional to the charge collecting area of the antenna. However, a quantitative relation between plasma process-induced oxide failure fraction and antenna ratio (AR) has not been found yet. In this paper, yield data of antenna testers have been correlated to the AR in a 0.18 Âżm CMOS technology process. A model is built which fits the experiment data very well. Based on this model, yield loss data obtained on large AR test structures can be used to extrapolate the charging currents and yield loss of smaller AR structures which occur more often in real circuit
A Class of Parametric Tree-Based Clustering Methods
We introduce a class of tree-based clustering methods based on a single parameter W and show how to generate the full collection of cluster sets C(W), without duplication, by varying W according to conditions identified during the algorithm’s execution. The number of clusters within C(W) for a given W is determined automatically, using a graph representation in which cluster elements are represented by nodes and their pairwise connections are represented by edges. We identify features of the clusters produced which lead to special procedures to accelerate the computation. Finally, we introduce a related node-based variant of the algorithm based on a parameter Y which can be used to generate clusters with complementary features, and a method that combines both variants based on a parameter Z and a weight that determines the contribution of each variant
Effect of extended tooth contact on the modeling of spur gear transmissions
In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the equations of motion are solved. This means the zone of tooth contact and average tooth meshing stiffness are underestimated and the individual tooth load is overstated, especially for heavily-loaded gears. The static transmission error and dynamic load of heavily-loaded, low-contact-ratio spur gears is compared with this effect both neglected and included. Neglecting the effect yields an underestimate of resonance speeds and an overestimate of the dynamic load
Weighted Marking, Clique Structure and Node- Weighted Centrality to Predict Distribution Centre’s Location in a Supply Chain Management
This is an open access article distributed under the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits unrestricted non-commerical use, distribution, and reproduction in any medium, provided the original work is properly cited.Despite the importance attached to the weights or strengths on the edges of a graph, a graph is only complete if it has both the combinations of nodes and edges. As such, this paper brings to bare the fact that the node-weight of a graph is also a critical factor to consider in any graph/network’s evaluation, rather than the link-weight alone as commonly considered. In fact, the combination of the weights on both the nodes and edges as well as the number of ties together contribute effectively to the measure of centrality for an entire graph or network, thereby clearly showing more information. Two methods which take into consideration both the link-weights and node-weights of graphs (the Weighted Marking method of prediction of location and the Clique/Node-Weighted centrality measures) are considered, and the result from the case studies shows that the clique/node-weighted centrality measures give an accuracy of 18% more than the weighted marking method, in the prediction of Distribution Centre location of the Supply Chain ManagementPeer reviewe
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On the Integrity of Online Testing for Introductory Statistics Courses: A Latent Variable Approach
There has been a remarkable growth in distance learning courses in higher education. Despite indications that distance learning courses are more vulnerable to cheating behavior than traditional courses, there has been little research studying whether online exams facilitate a relatively greater level of cheating. This article examines this issue by developing an approach using a latent variable to measure student cheating. This latent variable is linked to both known student mastery related variables and variables unrelated to student mastery. Grade scores from a proctored final exam and an unproctored final exam are used to test for increased cheating behavior in the unproctored exam Accessed 4,410 times on https://pareonline.net from April 11, 2015 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right
The dark septate endophyte Phialocephala sphaeroides suppresses conifer pathogen transcripts and promotes root growth of Norway spruce
Plant-associated microbes including dark septate endophytes (DSEs) of forest trees play diverse functional roles in host fitness including growth promotion and increased defence. However, little is known about the impact on the fungal transcriptome and metabolites during tripartite interaction involving plant host, endophyte and pathogen. To understand the transcriptional regulation of endophyte and pathogen during co-infection, Norway spruce (Picea abies) seedlings were infected with DSE Phialocephala sphaeroides, or conifer root-rot pathogen Heterobasidion parviporum, or both. Phialocephala sphaeroides showed low but stable transcripts abundance (a decrease of 40%) during interaction with Norway spruce and conifer pathogen. By contrast, H. parviporum transcripts were significantly reduced (92%) during co-infection. With RNA sequencing analysis, P. sphaeroides experienced a shift from cell growth to anti-stress and antagonistic responses, while it repressed the ability of H. parviporum to access carbohydrate nutrients by suppressing its carbohydrate/polysaccharide-degrading enzyme machinery. The pathogen on the other hand secreted cysteine peptidase to restrict free growth of P. sphaeroides. The expression of both DSE P. sphaeroides and pathogen H. parviporum genes encoding plant growth promotion products were equally detected in both dual and tripartite interaction systems. This was further supported by the presence of tryptophan-dependent indolic compound in liquid culture of P. sphaeroides. Norway spruce and Arabidopsis seedlings treated with P. sphaeroides culture filtrate exhibited auxin-like phenotypes, such as enhanced root hairs, and primary root elongation at low concentration but shortened primary root at high concentration. The results suggested that the presence of the endophyte had strong repressive or suppressive effect on H. parviporum transcripts encoding genes involved in nutrient acquisition.Peer reviewe
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