Roads and Trade: Evidence from the US

We estimate the effect of interstate highways on the level and composition of trade for US cities. Highways within cities have a large effect on the weight of city exports with an elasticity of approximately 0.5. We find little effect of highways on the total value of exports. Consistent with this, we find that cities with more highways specialize in sectors producing heavy goods

Assessment of metabolomic and proteomic biomarkers in detection and prognosis of progression of renal function in chronic kidney disease

Chronic kidney disease (CKD) is part of a number of systemic and renal diseases and may reach epidemic proportions over the next decade. Efforts have been made to improve diagnosis and management of CKD. We hypothesised that combining metabolomic and proteomic approaches could generate a more systemic and complete view of the disease mechanisms. To test this approach, we examined samples from a cohort of 49 patients representing different stages of CKD. Urine samples were analysed for proteomic changes using capillary electrophoresis-mass spectrometry and urine and plasma samples for metabolomic changes using different mass spectrometry-based techniques. The training set included 20 CKD patients selected according to their estimated glomerular filtration rate (eGFR) at mild (59.9±16.5 mL/min/1.73 m2; n = 10) or advanced (8.9±4.5 mL/min/1.73 m2; n = 10) CKD and the remaining 29 patients left for the test set. We identified a panel of 76 statistically significant metabolites and peptides that correlated with CKD in the training set. We combined these biomarkers in different classifiers and then performed correlation analyses with eGFR at baseline and follow-up after 2.8±0.8 years in the test set. A solely plasma metabolite biomarker-based classifier significantly correlated with the loss of kidney function in the test set at baseline and follow-up (ρ = −0.8031; p<0.0001 and ρ = −0.6009; p = 0.0019, respectively). Similarly, a urinary metabolite biomarker-based classifier did reveal significant association to kidney function (ρ = −0.6557; p = 0.0001 and ρ = −0.6574; p = 0.0005). A classifier utilising 46 identified urinary peptide biomarkers performed statistically equivalent to the urinary and plasma metabolite classifier (ρ = −0.7752; p<0.0001 and ρ = −0.8400; p<0.0001). The combination of both urinary proteomic and urinary and plasma metabolic biomarkers did not improve the correlation with eGFR. In conclusion, we found excellent association of plasma and urinary metabolites and urinary peptides with kidney function, and disease progression, but no added value in combining the different biomarkers data

Vitamin D and Calcium Supplementation Accelerates Randall's Plaque Formation in a Murine Model

Most kidney stones are made of calcium oxalate crystals. Randall\u27s plaque, an apatite deposit at the tip of the renal papilla, is considered to at the origin of these stones. Hypercalciuria may promote Randall\u27s plaque formation and growth. We analyzed whether long-term exposure of Abcc6 mice (a murine model of Randall\u27s plaque) to vitamin D supplementation, with or without a calcium-rich diet, would accelerate the formation of Randall\u27s plaque. Eight groups of mice (including Abcc6 and wild type) received vitamin D alone (100,000 UI/kg every 2 weeks), a calcium-enriched diet alone (calcium gluconate 2 g/L in drinking water), both vitamin D supplementation and a calcium-rich diet, or a standard diet (controls) for 6 months. Kidney calcifications were assessed by 3-dimensional microcomputed tomography, μ-Fourier transform infrared spectroscopy, field emission-scanning electron microscopy, transmission electron microscopy, and Yasue staining. At 6 months, Abcc6 mice exposed to vitamin D and calcium supplementation developed massive Randall\u27s plaque when compared with control Abcc6 mice (P < 0.01). Wild-type animals did not develop significant calcifications when exposed to vitamin D. Combined administration of vitamin D and calcium significantly accelerates Randall\u27s plaque formation in a murine model. This original model raises concerns about the cumulative risk of vitamin D supplementation and calcium intakes in Randall\u27s plaque formation

Modelling Hierarchy and Specialization of a System of Cities from an Evolutionary Perspective on Firms' Interactions

Despite their great diversity, most systems of cities show remarkably similar patterns when comparing the size distribution and the economic specialization of their constitutive cities. The universality of these patterns sparked the interest of geographers, economists and physicists. However, until now, no economic model has relied on a micro-based and evolutionary approach to reproduce these regularities. In this chapter, we intend to fill this gap by proposing a model where the micro dynamics of localized firms generate the two macro regularities of size distribution and economic specialization. The model is based on boundedly rational firms’ competition and path dependent innovation. We discuss the possible emergence of macro properties from these micro behaviors of firms

Cultural and creative industries and regional diversification:Does size matter?

This paper aims at analysing how the presence of workers employed in cultural and creative industries (CCIs) is related to regional specialized diversification. From a theoretical perspective, CCIs drive economic development and local innovative capacity by facilitating processes of cross-fertilization of ideas. This study estimates an entry model analysing the ability of Italian provinces to successfully create new sectoral specializations. The results indicate that the relationship between the share of employees in CCIs and the probability of creating new sectoral specializations is non-linear, highlighting the need for CCIs-led policies to achieve a certain level of critical mass to be successful

Heterogeneous Agglomeration

Many prior treatments of agglomeration explicitly or implicitly assume that all industries agglomerate for the same reasons. This paper uses U.K. establishment-level coagglomeration data to document substantial heterogeneity across industries in the microfoundations of agglomeration economies. It finds robust evidence of organizational and adaptive agglomeration forces as discussed by Chinitz (1961), Vernon (1960), and Jacobs (1969). These forces interact with the traditional Marshallian (1890) factors of input sharing, labor pooling, and knowledge spillovers, establishing a previously unrecognized complementarity between the approaches of Marshall and Jacobs, as well as others, to the analysis of agglomeration

Accelerated apoptotic death and <i>in vivo</i> turnover of erythrocytes in mice lacking functional mitogen- and stress-activated kinase MSK1/2

The mitogen- and stress-activated kinase MSK1/2 plays a decisive role in apoptosis. In analogy to apoptosis of nucleated cells, suicidal erythrocyte death called eryptosis is characterized by cell shrinkage and cell membrane scrambling leading to phosphatidylserine (PS) externalization. Here, we explored whether MSK1/2 participates in the regulation of eryptosis. To this end, erythrocytes were isolated from mice lacking functional MSK1/2 (msk−/−) and corresponding wild-type mice (msk+/+). Blood count, hematocrit, hemoglobin concentration and mean erythrocyte volume were similar in both msk−/− and msk+/+ mice, but reticulocyte count was significantly increased in msk−/− mice. Cell membrane PS exposure was similar in untreated msk−/− and msk+/+ erythrocytes, but was enhanced by pathophysiological cell stressors ex vivo such as hyperosmotic shock or energy depletion to significantly higher levels in msk−/− erythrocytes than in msk+/+ erythrocytes. Cell shrinkage following hyperosmotic shock and energy depletion, as well as hemolysis following decrease of extracellular osmolarity was more pronounced in msk−/− erythrocytes. The in vivo clearance of autologously-infused CFSE-labeled erythrocytes from circulating blood was faster in msk−/− mice. The spleens from msk−/− mice contained a significantly greater number of PS-exposing erythrocytes than spleens from msk+/+ mice. The present observations point to accelerated eryptosis and subsequent clearance of erythrocytes leading to enhanced erythrocyte turnover in MSK1/2-deficient mice

Micro-behaviors and structural properties of knowledge networks: toward a 'one size fits one'cluster policy

The economic returns of cluster policies have been recently called into question. Based on a “one size fits all” approach consisting in boosting R&D collaborations and reinforcing network density, cluster policies are suspected to have failed in reaching their objectives. The paper proposes to go back to the micro foundations of clusters in order to disentangle the links between the long run performance of clusters and their structural properties. We use a simple agent-based model to shed light on how individual motives to build knowledge relationships can give rise to emerging structures with different properties, which imply different innovation and renewal capacities. The simulation results are discussed in a micro-macro perspective, and motivate suggestions to reorient cluster policy guidelines towards more targeted public-funded incentives for R&D collaboration