288 research outputs found
Inducing more efficient payment on the Illinois Tollway
Historically, an important part of Chicago’s economic strength derived from its geographic location at the nexus of the country’s transportation networks. Yet, until quite recently, the payment options on the Illinois Tollway seemed incongruous with the remarkably efficient transportation network that has kept Chicago on the country’s economic forefront.
Transforming payment choices by doubling fees on the Illinois tollway
Rising traffic congestion and the need to improve operational efficiency prompted the Illinois Tollway Authority to unveil plans to reconfigure its road network for “stop-free” electronic toll collection. Committing to an extensive construction program would have required the Tollway to ensure that enough drivers had electronic payment devices (branded as I- PASS). Conversely, without reconfigured toll gates the drivers would have had less reason to own an I-PASS. To resolve this potentially thorny chicken-and-egg problem, the Tollway put in place a new I-PASS distribution network and then dramatically raised the price for cash toll payments. This paper focuses on consumer response to the change in relative prices. Using tollway traffic data, we document a substantial aggregate increase in electronic toll payments. The propensity to pay electronically rose uniformly throughout the day, reflecting the effectiveness of the Tollway’s actions in modifying behavior of both commuters and leisure drivers. ; However, not all drivers appear to have responded to the price change per se. To analyze the relative importance of price, income, and fixed participation costs we use the Census tract level data on employment and residential location to construct a ZIP-code measure of the likelihood of commuting to work via the tollway. Conditional on this measure, we show that the adoption of electronic payments among lower-income households was indeed influenced by the price change. In contrast, high- and medium-income households responded to lower fixed costs of obtaining I-PASS at conveniently located supermarkets. Finally, we document the role of social network relationships, as changes in I-PASS ownership for all income groups were strongly affected by I-PASS use among neighbors and co- workers.Toll roads ; Toll roads - Illinois
Transforming payment choices by doubling fees on the Illinois Tollway
Using data from the Illinois Tollway, the authors study the effectiveness of a particular application of pricing incentives, in conjunction with a mass-marketing campaign, to foster adoption of electronic toll collection. Dissecting the consumer response by income level, the authors reveal interesting heterogeneity of consumer payment choice in this environment.Toll roads ; Toll roads - Illinois
Using payment innovations to improve transportation networks: a conference summary
On June 12, 2007, Chicago Metropolis 2020 and the Federal Reserve Bank of Chicago jointly hosted a conference to discuss road pricing strategies, as well as other issues related to reducing transportation congestion and improving economic efficiency in the Chicago region and around the world. On June 12, 2007, Chicago Metropolis 2020 and the Federal Reserve Bank of Chicago jointly hosted a conference to discuss road pricing strategies, as well as other issues related to reducing transportation congestion and improving economic efficiency in the Chicago region and around the world.Toll roads ; Payment systems
Global diversity of inland water cnidarians
Global diversity of inland water cnidarians is low, containing <40 species belonging to phylogenetically distinct groups representing independent invasion events: the common and cosmopolitan hydras (12-15species); the sporadically occurring freshwater medusae (6-16sp.); the Cordylophorinae (2sp.); the parasitic Polypodium (1sp.); the medusae occurring in saline lakes (4sp.). Freshwater cnidarians inhabit nearly all types of freshwater on all continents (except Antarctica), but only a few species have cosmopolitan distributions. Due to uncertainty in species knowledge, fine scale regions of endemicity are not yet clea
Mrgprd Enhances Excitability in Specific Populations of Cutaneous Murine Polymodal Nociceptors
The Mas-related G protein-coupled receptor D (Mrgprd) is selectively expressed in nonpeptidergic nociceptors that innervate the outer layers of mammalian skin. The function of Mrgprd in nociceptive neurons and the physiologically relevant somatosensory stimuli that activate Mrgprd^-expressing (Mrgprd^+) neurons are currently unknown. To address these issues, we studied three Mrgprd knock-in mouse lines using an ex vivo somatosensory preparation to examine the role of the Mrgprd receptor and Mrgprd+ afferents in cutaneous somatosensation. In mouse hairy skin, Mrgprd, as marked by expression of green fluorescent protein reporters, was expressed predominantly in the population of nonpeptidergic, TRPV1-negative, C-polymodal nociceptors. In mice lacking Mrgprd, this population of nociceptors exhibited decreased sensitivity to cold, heat, and mechanical stimuli. Additionally, in vitro patch-clamp studies were performed on cultured dorsal root ganglion neurons from Mrgprd^(–/–) and Mrgprd^(+/–) mice. These studies revealed a higher rheobase in neurons from Mrgprd^(–/–) mice than from Mrgprd^(+/–) mice. Furthermore, the application of the Mrgprd ligand β-alanine significantly reduced the rheobase and increased the firing rate in neurons from Mrgprd^(+/–) mice but was without effect in neurons from Mrgprd^(–/–) mice. Our results demonstrate that Mrgprd influences the excitability of polymodal nonpeptidergic nociceptors to mechanical and thermal stimuli
Rhabdomyosarcoma cells show an energy producing anabolic metabolic phenotype compared with primary myocytes
<p>Abstract</p> <p>Background</p> <p>The functional status of a cell is expressed in its metabolic activity. We have applied stable isotope tracing methods to determine the differences in metabolic pathways in proliferating Rhabdomysarcoma cells (Rh30) and human primary myocytes in culture. Uniformly <sup>13</sup>C-labeled glucose was used as a source molecule to follow the incorporation of <sup>13</sup>C into more than 40 marker metabolites using NMR and GC-MS. These include metabolites that report on the activity of glycolysis, Krebs' cycle, pentose phosphate pathway and pyrimidine biosynthesis.</p> <p>Results</p> <p>The Rh30 cells proliferated faster than the myocytes. Major differences in flux through glycolysis were evident from incorporation of label into secreted lactate, which accounts for a substantial fraction of the glucose carbon utilized by the cells. Krebs' cycle activity as determined by <sup>13</sup>C isotopomer distributions in glutamate, aspartate, malate and pyrimidine rings was considerably higher in the cancer cells than in the primary myocytes. Large differences were also evident in de novo biosynthesis of riboses in the free nucleotide pools, as well as entry of glucose carbon into the pyrimidine rings in the free nucleotide pool. Specific labeling patterns in these metabolites show the increased importance of anaplerotic reactions in the cancer cells to maintain the high demand for anabolic and energy metabolism compared with the slower growing primary myocytes. Serum-stimulated Rh30 cells showed higher degrees of labeling than serum starved cells, but they retained their characteristic anabolic metabolism profile. The myocytes showed evidence of de novo synthesis of glycogen, which was absent in the Rh30 cells.</p> <p>Conclusion</p> <p>The specific <sup>13</sup>C isotopomer patterns showed that the major difference between the transformed and the primary cells is the shift from energy and maintenance metabolism in the myocytes toward increased energy and anabolic metabolism for proliferation in the Rh30 cells. The data further show that the mitochondria remain functional in Krebs' cycle activity and respiratory electron transfer that enables continued accelerated glycolysis. This may be a common adaptive strategy in cancer cells.</p
Solute and sediment export from Amazon forest and soybean headwater streams
Author Posting. © Ecological Society of America, 2016. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecological Applications 27 (2017): 193–207, doi:10.1002/eap.1428.Intensive cropland agriculture commonly increases streamwater solute concentrations and export from small watersheds. In recent decades, the lowland tropics have become the world's largest and most important region of cropland expansion. Although the effects of intensive cropland agriculture on streamwater chemistry and watershed export have been widely studied in temperate regions, their effects in tropical regions are poorly understood. We sampled seven headwater streams draining watersheds in forest (n = 3) or soybeans (n = 4) to examine the effects of soybean cropping on stream solute concentrations and watershed export in a region of rapid soybean expansion in the Brazilian state of Mato Grosso. We measured stream flows and concentrations of NO3−, PO43−, SO42−, Cl−, NH4+, Ca2+, Mg2+, Na+, K+, Al3+, Fe3+, and dissolved organic carbon (DOC) biweekly to monthly to determine solute export. We also measured stormflows and stormflow solute concentrations in a subset of watersheds (two forest, two soybean) during two/three storms, and solutes and δ18O in groundwater, rainwater, and throughfall to characterize watershed flowpaths. Concentrations of all solutes except K+ varied seasonally in streamwater, but only Fe3+ concentrations differed between land uses. The highest streamwater and rainwater solute concentrations occurred during the peak season of wildfires in Mato Grosso, suggesting that regional changes in atmospheric composition and deposition influence seasonal stream solute concentrations. Despite no concentration differences between forest and soybean land uses, annual export of NH4+, PO43−, Ca2+, Fe3+, Na+, SO42−, DOC, and TSS were significantly higher from soybean than forest watersheds (5.6-fold mean increase). This increase largely reflected a 4.3-fold increase in water export from soybean watersheds. Despite this increase, total solute export per unit watershed area (i.e., yield) remained low for all watersheds (<1 kg NO3− N·ha−1·yr−1, <2.1 kg NH4+-N·ha−1·yr−1, <0.2 kg PO43−-P·ha−1·yr−1, <1.5 kg Ca2+·ha−1·yr−1). Responses of both streamflows and solute concentrations to crop agriculture appear to be controlled by high soil hydraulic conductivity, groundwater-dominated hydrologic flowpaths on deep soils, and the absence of nitrogen fertilization. To date, these factors have buffered streams from the large increases in solute concentrations that often accompany intensive croplands in other locations.NSF Grant Numbers: DEB-0640661, DEB-0949370;
Fundação de Amparo á Pesquisa do Estado de São Paulo Grant Number: FAPESP 03/13172-2;
Watson Graduate Student Fellowship;
Center for Latin American and Caribbean Studies at Brown Universit
Cutaneous C-polymodal fibers lacking TRPV1 are sensitized to heat following inflammation, but fail to drive heat hyperalgesia in the absence of TPV1 containing C-heat fibers
<p>Abstract</p> <p>Background</p> <p>Previous studies have shown that the TRPV1 ion channel plays a critical role in the development of heat hyperalgesia after inflammation, as inflamed TRPV1-/- mice develop mechanical allodynia but fail to develop thermal hyperalgesia. In order to further investigate the role of TRPV1, we have used an ex vivo skin/nerve/DRG preparation to examine the effects of CFA-induced-inflammation on the response properties of TRPV1-positive and TRPV1-negative cutaneous nociceptors.</p> <p>Results</p> <p>In wildtype mice we found that polymodal C-fibers (CPMs) lacking TRPV1 were sensitized to heat within a day after CFA injection. This sensitization included both a drop in average heat threshold and an increase in firing rate to a heat ramp applied to the skin. No changes were observed in the mechanical response properties of these cells. Conversely, TRPV1-positive mechanically insensitive, heat sensitive fibers (CHs) were not sensitized following inflammation. However, results suggested that some of these fibers may have gained mechanical sensitivity and that some previous silent fibers gained heat sensitivity. In mice lacking TRPV1, inflammation only decreased heat threshold of CPMs but did not sensitize their responses to the heat ramp. No CH-fibers could be identified in naïve nor inflamed TRPV1-/- mice.</p> <p>Conclusions</p> <p>Results obtained here suggest that increased heat sensitivity in TRPV1-negative CPM fibers alone following inflammation is insufficient for the induction of heat hyperalgesia. On the other hand, TRPV1-positive CH fibers appear to play an essential role in this process that may include both afferent and efferent functions.</p
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