Visibility, perception and roundabout safety

In Italy, over the past fifteen years, modern, or second generation roundabouts have become very popular. In these roundabouts, entering vehicles must yield to vehicles already within the circle. This modern design provides for much higher capacity of operation. Although first implemented in the UK in the 1960s, it took twenty years for the second generation to begin to spread to other European countries. Between 1987 and 2002, in particular, Germany, France and Switzerland conducted research that led to standards techniques that, along with English ones, now comprise the major technical references. The causes of the delay in implementation are uncertain and the subject of much speculation. The United States has only recently begun implementation, as it was not until the 1998 version did a chapter on roundabouts appear in the Highway Capacity Manual (developed further in the 2000 edition). In Italy, the first standards were proposed for the 1993 New Road Code, but it was not until 2004 that the standards were passed through national legislation. However, these codes are approximate and inadequate, and lack elementary technical foundations (see for instance Art. 4.5 of D.M. 19/04/2006, no.1699). A quick calculation for 4 legs and 60 meters diameter is sufficient to demonstrate its failure and infeasibility. The design of a roundabout, like that of any other road element, should be based on principles of safety, and should be deployed in a systemic context that combines geometric characteristics to meet capacity requirements – the perception of road space is also important. When designing a roundabout, the engineer should consider simultaneously both safety factors and capacity. But in addition to using geometric standards, formulas and models, aspects of perception and visual appeal should be considered

Raised crosswalks efficacy on the lowering of vehicle speeds

A road hump, or speed hump, is a traffic calming device used to reduce vehicle speed and volume on residential streets. Road humps are placed across the road to slow traffic and are often installed in a series of several humps in order to prevent cars from speeding before and after the hump. Speed humps are used in locations where very low speeds are desired and reasonable. Speed humps are typically placed on residential roads and are not used on major roads, bus routes, or primary emergency response routes. In Italy, the road humps are often built in shape of raised crosswalks, or RCWs, and they are generally placed both close and between intersections. This paper deals with the analysis of observed data on a large sample of RCWs located in Tuscany, central Italy. Such data were referred both to geometry characteristics of the single raised crosswalk and recorded differences in vehicle speeds before and after it. Speed data were gathered using two automatic radar-recorders for each one of the sampled raised crosswalks. All the collected data were analyzed trough statistical tests in order to assess their homogeneity or not between different locations and various types of roads. Finally, we were able of making some conclusions and highlighting design aspects. On one side, RCWs with similar geometries and higher heights (about 15 cm) have similar effects on vehicle speeds lowering, regardless of local conditions (location, road geometry, driver behaviour, etc.). Moreover, raised crosswalks installed in a series have strong efficacy than the isolated ones. On the opposite side, the effects of raised crosswalks with smaller heights (less than 6 cm) show clearly a very low influence on vehicle speed variations

Estimation of Gap Acceptance Parameters for HCM 2010 Roundabout Capacity Model Applications

This paper deals with the field data observation and successive application of estimation procedures in order to estimate follow-up headway and critical headway at roundabouts. Average follow-up and average critical headway are two critical parameters in the new roundabout capacity model presented in the 2010 edition of the Highway Capacity Manual (HCM). The HCM 2010 capacity model was developed as an exponential regression model with parameter estimates based on gap acceptance theory. Gap acceptance models are strongly affected by driver behaviour and local habits. Follow-up headways can be field measured, while critical headway cannot be obtained directly. The paper mainly aims to check if general suggested values are well-suited also for Italy or not. There have been numerous techniques developed for estimating critical headway. In order to perform a better check of a sample of experimentally observed values, three different procedures are chosen and applied. The first is a quite popular mathematical method based on maximum likelihood technique. The second is a statistical method based on the median of the observed sample distribution. The third is a graphical method known as Raff’s method. All these three methods require information about the accepted headway and the largest rejected headway for each driver. Therefore a sample of field data was recorded by digital camera and processed following the instructions suggested by NCHRP. The sample data of critical headway and follow-up headway are gathered in seven selected roundabouts located in Northern Tuscany (Italy). Our first obtained results indicate that the average critical headway is significantly lower than the values recommended by some international references. However, the average follow-up headway is only higher than that recommended for the State of California and it is lower than that recommended by all other international references. Finally, conclusions drawn along with insights for further research developments are suggested

Improving Sustainable Mobility through Modal Rewarding: The GOOD_GO Smart Platform

Private car mobility registers today a h igh accident rate and around 70% of the overall CO2 emissions from transport were generated by road mode split (European Commission, 2016). Moreover, in urban areas they occur 38% of the overall fatalities from road transport, and 23% of the overall CO2 emissions (European Commission, 2013). As a result, a modal shift of at least a part of passenger transport in urban areas, from private car to sustainable transport systems is desirable. This research aims to promote sustainable mobility through two mutually reinforcing "main actions": firstly, there is a r ewarding Open-Source platform, named as GOOD_GO; secondly, there is the SW/HW system connecting to the wide world of private and/or shared bicycles. Through the GOOD_GO platform Web portal and App, a user enters a so called 'social rewarding game' thought to incentive sustainable mobility habits, and gets access to the second item consisting of a system to disincentive bike-theft and based on the passive RFID technology. The low-cost deterrent bike-theft and bike monitoring/tracking system is functional to bring a big number of citizens inside the rewarding game. In 2018, a pilot test has implemented in the city of Livorno (Tuscany, It), and it involved around 1,000 citizens. Results were quite encouraging and today, the cities of Livorno, Pisa and Bolzano will enlarge the incentive system both to home-to-school and home-to-work mobility. The Good_Go platform is an actual M-a-a-S (Mobility-as-a-Service) application, and it becoming a Mobility Management decision system support, jointly with the opportunity of organizing more incentive tenders and rewarding systems types

Natural bovine coronavirus infection in a calf persistently infected with bovine viral diarrhea virus: Viral shedding, immunological features and s gene variations

The evolution of a bovine coronavirus (BCoV) natural infection in a calf persistently infected with bovine viral diarrhea virus (BVDV) was described. The infected calf developed intermittent nasal discharge, diarrhea and hyperthermia. The total number of leukocytes/mL and the absolute differential number of neutrophils and lymphocytes resulted within the normal range, but monocytes increased at T28 (time 28 post‐infection). Flow‐cytometry analysis evidenced that the CD8+ subpopulation increased at T7 and between T28 and T35. BCoV shedding in nasal discharges and feces was detected up to three weeks post infection and high antibody titers persisted up to T56. The RNA BCoV load increased until T14, contrary to what was observed in a previous study where the fecal excretion of BCoV was significantly lower in the co‐infected (BCoV/BVDV) calves than in the calves infected with BCoV only. We can suppose that BVDV may have modulated the BCoV infection exacerbating the long viral excretion, as well as favoring the onset of mutations in the genome of BCoV detected in fecal samples at T21. An extensive study was performed to verify if the selective pressure in the S gene could be a natural mode of variation of BCoV, providing data for the identification of new epidemic strains, genotypes or recombinant betacoronaviruses

A glimpse into the differential topology and geometry of optimal transport

This note exposes the differential topology and geometry underlying some of the basic phenomena of optimal transportation. It surveys basic questions concerning Monge maps and Kantorovich measures: existence and regularity of the former, uniqueness of the latter, and estimates for the dimension of its support, as well as the associated linear programming duality. It shows the answers to these questions concern the differential geometry and topology of the chosen transportation cost. It also establishes new connections --- some heuristic and others rigorous --- based on the properties of the cross-difference of this cost, and its Taylor expansion at the diagonal.Comment: 27 page

Canine respiratory coronavirus employs caveolin-1-mediated pathway for internalization to HRT-18G cells

Canine respiratory coronavirus (CRCoV), identified in 2003, is a member of the Coronaviridae family. The virus is a betacoronavirus and a close relative of human coronavirus OC43 and bovine coronavirus. Here, we examined entry of CRCoV into human rectal tumor cells (HRT-18G cell line) by analyzing co-localization of single virus particles with cellular markers in the presence or absence of chemical inhibitors of pathways potentially involved in virus entry. We also targeted these pathways using siRNA. The results show that the virus hijacks caveolin-dependent endocytosis to enter cells via endocytic internalization

A Membrane Protein/Signaling Protein Interaction Network for Arabidopsis Version AMPv2

Interactions between membrane proteins and the soluble fraction are essential for signal transduction and for regulating nutrient transport. To gain insights into the membrane-based interactome, 3,852 open reading frames (ORFs) out of a target list of 8,383 representing membrane and signaling proteins from Arabidopsis thaliana were cloned into a Gateway-compatible vector. The mating-based split ubiquitin system was used to screen for potential protein–protein interactions (pPPIs) among 490 Arabidopsis ORFs. A binary robotic screen between 142 receptor-like kinases (RLKs), 72 transporters, 57 soluble protein kinases and phosphatases, 40 glycosyltransferases, 95 proteins of various functions, and 89 proteins with unknown function detected 387 out of 90,370 possible PPIs. A secondary screen confirmed 343 (of 386) pPPIs between 179 proteins, yielding a scale-free network (r2 = 0.863). Eighty of 142 transmembrane RLKs tested positive, identifying 3 homomers, 63 heteromers, and 80 pPPIs with other proteins. Thirty-one out of 142 RLK interactors (including RLKs) had previously been found to be phosphorylated; thus interactors may be substrates for respective RLKs. None of the pPPIs described here had been reported in the major interactome databases, including potential interactors of G-protein-coupled receptors, phospholipase C, and AMT ammonium transporters. Two RLKs found as putative interactors of AMT1;1 were independently confirmed using a split luciferase assay in Arabidopsis protoplasts. These RLKs may be involved in ammonium-dependent phosphorylation of the C-terminus and regulation of ammonium uptake activity. The robotic screening method established here will enable a systematic analysis of membrane protein interactions in fungi, plants and metazoa

MoVam7, a Conserved SNARE Involved in Vacuole Assembly, Is Required for Growth, Endocytosis, ROS Accumulation, and Pathogenesis of Magnaporthe oryzae

Soluble NSF attachment protein receptor (SNARE) proteins play a central role in membrane fusion and vesicle transport of eukaryotic organisms including fungi. We previously identified MoSce22 as a homolog of Saccharomyces cerevisiae SNARE protein Sec22 to be involved in growth, stress resistance, and pathogenicity of Magnaporthe oryzae. Here, we provide evidences that MoVam7, an ortholog of S. cerevisiae SNARE protein Vam7, exerts conserved functions in vacuolar morphogenesis and functions in pathogenicity of M. oryzae. Staining with neutral red and FM4-64 revealed the presence of abnormal fragmented vacuoles and an absence of the Spitzenkörper body in the ΔMovam7 mutant. The ΔMovam7 mutant also exhibited reduced vegetative growth, poor conidiation, and failure to produce the infection structure appressorium. Additionally, treatments with cell wall perturbing agents indicated weakened cell walls and altered distributions of the cell wall component chitin. Furthermore, the ΔMovam7 mutant showed a reduced accumulation of reactive oxygen species (ROS) in the hyphal apex and failed to cause diseases on the rice plant. In summary, our studies indicate that MoVam7, like MoSec22, is a component of the SNARE complex whose functions in vacuole assembly also underlies the growth, conidiation, appressorium formation, and pathogenicity of M. oryzae. Further studies of MoVam7, MoSec22, and additional members of the SNARE complex are likely to reveal critical mechanisms in vacuole formation and membrane trafficking that is linked to fungal pathogenicity