Parallelized Particle and Gaussian Sum Particle Filters for Large Scale Freeway Traffic Systems

Large scale traffic systems require techniques able to: 1) deal with high amounts of data and heterogenous data coming from different types of sensors, 2) provide robustness in the presence of sparse sensor data, 3) incorporate different models that can deal with various traffic regimes, 4) cope with multimodal conditional probability density functions for the states. Often centralized architectures face challenges due to high communication demands. This paper develops new estimation techniques able to cope with these problems of large traffic network systems. These are Parallelized Particle Filters (PPFs) and a Parallelized Gaussian Sum Particle Filter (PGSPF) that are suitable for on-line traffic management. We show how complex probability density functions of the high dimensional trafc state can be decomposed into functions with simpler forms and the whole estimation problem solved in an efcient way. The proposed approach is general, with limited interactions which reduces the computational time and provides high estimation accuracy. The efciency of the PPFs and PGSPFs is evaluated in terms of accuracy, complexity and communication demands and compared with the case where all processing is centralized

Mg\u3csup\u3e2+\u3c/sup\u3e Differentially Regulates Two Modes of Mitochondrial Ca\u3csup\u3e2+\u3c/sup\u3e Uptake in Isolated Cardiac Mitochondria: Implications for Mitochondrial Ca\u3csup\u3e2+\u3c/sup\u3e Sequestration

The manner in which mitochondria take up and store Ca2+ remains highly debated. Recent experimental and computational evidence has suggested the presence of at least two modes of Ca2+ uptake and a complex Ca2+ sequestration mechanism in mitochondria. But how Mg2+ regulates these different modes of Ca2+ uptake as well as mitochondrial Ca2+ sequestration is not known. In this study, we investigated two different ways by which mitochondria take up and sequester Ca2+ by using two different protocols. Isolated guinea pig cardiac mitochondria were exposed to varying concentrations of CaCl2 in the presence or absence of MgCl2. In the first protocol, A, CaCl2 was added to the respiration buffer containing isolated mitochondria, whereas in the second protocol, B, mitochondria were added to the respiration buffer with CaCl2 already present. Protocol A resulted first in a fast transitory uptake followed by a slow gradual uptake. In contrast, protocol B only revealed a slow and gradual Ca2+ uptake, which was approximately 40 % of the slow uptake rate observed in protocol A. These two types of Ca2+ uptake modes were differentially modulated by extra-matrix Mg2+. That is, Mg2+ markedly inhibited the slow mode of Ca2+ uptake in both protocols in a concentration-dependent manner, but not the fast mode of uptake exhibited in protocol A. Mg2+ also inhibited Na+-dependent Ca2+ extrusion. The general Ca2+ binding properties of the mitochondrial Ca2+ sequestration system were reaffirmed and shown to be independent of the mode of Ca2+ uptake, i.e. through the fast or slow mode of uptake. In addition, extra-matrix Mg2+ hindered Ca2+ sequestration. Our results indicate that mitochondria exhibit different modes of Ca2+ uptake depending on the nature of exposure to extra-matrix Ca2+, which are differentially sensitive to Mg2+. The implications of these findings in cardiomyocytes are discussed

Extra-matrix Mg\u3csup\u3e2+\u3c/sup\u3e Limits Ca\u3csup\u3e2+\u3c/sup\u3e Uptake and Modulates Ca\u3csup\u3e2+\u3c/sup\u3e Uptake-independent Respiration and Redox State in Cardiac Isolated Mitochondria

Cardiac mitochondrial matrix (m) free Ca2+ ([Ca2+]m) increases primarily by Ca2+ uptake through the Ca2+ uniporter (CU). Ca2+ uptake via the CU is attenuated by extra-matrix (e) Mg2+ ([Mg2+]e). How [Ca2+]m is dynamically modulated by interacting physiological levels of [Ca2+]e and [Mg2+]e and how this interaction alters bioenergetics are not well understood. We postulated that as [Mg2+]e modulates Ca2+ uptake via the CU, it also alters bioenergetics in a matrix Ca2+–induced and matrix Ca2+–independent manner. To test this, we measured changes in [Ca2+]e, [Ca2+]m, [Mg2+]e and [Mg2+]m spectrofluorometrically in guinea pig cardiac mitochondria in response to added CaCl2 (0–0.6 mM; 1 mM EGTA buffer) with/without added MgCl2 (0–2 mM). In parallel, we assessed effects of added CaCl2 and MgCl2 on NADH, membrane potential (ΔΨm), and respiration. We found that \u3e0.125 mM MgCl2 significantly attenuated CU-mediated Ca2+ uptake and [Ca2+]m. Incremental [Mg2+]e did not reduce initial Ca2+uptake but attenuated the subsequent slower Ca2+ uptake, so that [Ca2+]m remained unaltered over time. Adding CaCl2 without MgCl2 to attain a [Ca2+]m from 46 to 221 nM enhanced state 3 NADH oxidation and increased respiration by 15 %; up to 868 nM [Ca2+]m did not additionally enhance NADH oxidation or respiration. Adding MgCl2 did not increase [Mg2+]m but it altered bioenergetics by its direct effect to decrease Ca2+ uptake. However, at a given [Ca2+]m, state 3 respiration was incrementally attenuated, and state 4 respiration enhanced, by higher [Mg2+]e. Thus, [Mg2+]e without a change in [Mg2+]m can modulate bioenergetics independently of CU-mediated Ca2+ transport

Agribusiness Cluster Impact Analysis on Economics Effectiveness of Soybean Producers in Benin

The purpose of this study is to analyze the impact of agricultural clusters on the economic effectiveness of Benin's soybean producers. The questionnaire has been sent to a total of 360 of producers those belonging to an Agribusiness Cluster (ABC) and who do not participate. The invested producers were selected randomly. The data have been analyzed by the process of propensity scores matching (PSM), but before that the technical, allocative and economic efficiencies of these producers were estimated using the function of the stochastic borders. At the end of the analyses, the producers in the study area are average effectively at 53.64%. The results show that some of the method of estimating the ABC membership effect, the agribusiness cluster has a positive and significant positive effect on economic efficiency. So policies can be based on this tool in this perspective to make more produce producers globally. Keywords: Agribusiness Cluster (ABC); Economic efficiency; Pairing of propensity scores; Soybea

Long-Term Potentiation in Isolated Dendritic Spines

BACKGROUND:In brain, N-methyl-D-aspartate (NMDA) receptor (NMDAR) activation can induce long-lasting changes in synaptic alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor (AMPAR) levels. These changes are believed to underlie the expression of several forms of synaptic plasticity, including long-term potentiation (LTP). Such plasticity is generally believed to reflect the regulated trafficking of AMPARs within dendritic spines. However, recent work suggests that the movement of molecules and organelles between the spine and the adjacent dendritic shaft can critically influence synaptic plasticity. To determine whether such movement is strictly required for plasticity, we have developed a novel system to examine AMPAR trafficking in brain synaptosomes, consisting of isolated and apposed pre- and postsynaptic elements. METHODOLOGY/PRINCIPAL FINDINGS:We report here that synaptosomes can undergo LTP-like plasticity in response to stimuli that mimic synaptic NMDAR activation. Indeed, KCl-evoked release of endogenous glutamate from presynaptic terminals, in the presence of the NMDAR co-agonist glycine, leads to a long-lasting increase in surface AMPAR levels, as measured by [(3)H]-AMPA binding; the increase is prevented by an NMDAR antagonist 2-amino-5-phosphonopentanoic acid (AP5). Importantly, we observe an increase in the levels of GluR1 and GluR2 AMPAR subunits in the postsynaptic density (PSD) fraction, without changes in total AMPAR levels, consistent with the trafficking of AMPARs from internal synaptosomal compartments into synaptic sites. This plasticity is reversible, as the application of AMPA after LTP depotentiates synaptosomes. Moreover, depotentiation requires proteasome-dependent protein degradation. CONCLUSIONS/SIGNIFICANCE:Together, the results indicate that the minimal machinery required for LTP is present and functions locally within isolated dendritic spines

THEORETICAL INVESTIGATION OF STRESSES DISTRIBUTIONS IN HOLLOW SANDCRETE BLOCKS DUE TO VARIATION OF CAVITY SIZES AND NUMBER WEB THICKNESS

The relationship between cavity size and number on one hand and combinations of web thicknesses were investigated theoretically. The least number of cavities was 4 for end-web to centre web ratio of 1:2 at constant shell thickness with the least web thickness equal to 12.5mm. The effects of the number of cavities and web thickness on strength were also investigated. The test thin plate distributes the load on the block and the hollow block is regarded as a two way slab. One of the principal findings is that the variation of maximum stresses with the number of cavity is Gaussian for end-web to centre-web ratio of 1:1 but polynomial for 1:2. In addition, the lowest stress is induced when the end to centre ratio is one. The maximum stress, (21.5N/mm2) occurred at the cavity length (a*) of 125mm for 3 cavities while the end (end centre) web thickness (t) was 25mm respectively. In order words, this combination should be avoided as it will lead to creation of highest stress in the hollow sandcrete blocks. The configuration which will result in least stress (0.5N/mm2) is (a *, N, t) = (50mm, 4mm, 50mm). However, this combination also gave a high maximum stress (6.9N/mm2) in a web, implying that the right choice of configuration should be rather the one that creates the smallest set of maximum stresses in all members. Overall, the best configuration is 2 cavities with web thickness 50mm for an end web to centre web ratio of 1:1 (3.3N/mm2). The corresponding values for 1: 2 ratios are 3 cavities with 50mm shell thickness (4.8N/mm2). The method presented showed meaningful insight could be investigating theoretically. http://dx.doi.org/10.4314/njt.v35i2.