Density Models and Safety Analysis for Rural Unsignalised Restricted Crossing U-turn Intersections

AbstractThe first objective of this study was to provide designers with a model that would help them assess the suitability of implementing an unsignalized restricted crossing U-turn (RCUT) based on the traffic volume arriving to a given rural intersection. Specifically, this study identified the zones that were most susceptible to bottlenecks and provided regression models that calculate the traffic density as a function of the traffic volume. In addition, the second objective of this study was to look at how the number of traffic conflicts varied with the traffic volume. Two geometric design cases were studied: four-lane and six-lane arterials using 1000 foot long (305 m long) weaving sections. VISSIM traffic simulations were used to identify the critical zones, and calculate the traffic density for different traffic flows. Volumes and densities allowed the development of regression models. Two critical zones were identified: where vehicles coming from the minor road merge to enter the U-turn and where vehicles exiting the U-turn merge to the multilane arterial. Also, based on the classification given by this study to the traffic volumes, a sensitivity analysis determined which of them had the greatest impact on the level of service. For the number of traffic conflicts from simulation, the Surrogate Safety Analysis Model was applied to measure them. This study found that at certain traffic volumes, traffic conflicts rise sharply. © 2011 Published by Elsevier Ltd

Dysregulation of Cytokine Response in Canadian First Nations Communities: Is There an Association with Persistent Organic Pollutant Levels?

In vitro and animal studies report that some persistent organic pollutants (POPs) trigger the secretion of proinflammatory cytokines. Whether POP exposure is associated with a dysregulation of cytokine response remains to be investigated in humans. We studied the strength of association between plasma POP levels and circulating cytokines as immune activation markers. Plasma levels of fourteen POPs and thirteen cytokines were measured in 39 Caucasians from a comparator sample in Québec City (Canada) and 72 First Nations individuals from two northern communities of Ontario (Canada). Caucasians showed significantly higher levels of organochlorine insecticides (β-HCH, p,p′-DDE and HCB) compared to First Nations. Conversely, First Nations showed higher levels of Mirex, Aroclor 1260, PCB 153, PCB 170, PCB 180 and PCB 187 compared to Caucasians. While there was no difference in cytokine levels of IL-4, IL-6, IL-10 and IL-22 between groups, First Nations had significantly greater average levels of IFNγ, IL-1β, IL-2, IL-5, IL-8, IL-12p70, IL-17A, TNFα and TNFβ levels compared to Caucasians. Among candidate predictor variables (age, body mass index, insulin resistance and POP levels), high levels of PCBs were the only predictor accounting for a small but significant effect of observed variance (∼7%) in cytokine levels. Overall, a weak but significant association is detected between persistent organochlorine pollutant exposure and elevated cytokine levels. This finding augments the already existing information that environmental pollution is related to inflammation, a common feature of several metabolic disorders that are known to be especially prevalent in Canada's remote First Nations communities

Coastal scenic assessment and tourism management in western Cuba

Coastal scenic assessments via checklist tables (18 natural, 8 human related parameters), can provide benchmark measures regarding desirable/non-desirable beach conditions and also classify sites. The scenic value for 43 sites in western Cuba was investigated, with the aim of helping managers improve bathing areas, especially for tourism purposes. Sites were categorised from Class 1, (top grade scenery), between La Habana and Matanzas, as extremely attractive, with white sand, turquoise water and additional scenic elements. Class 2 sites were located in Varadero, and their high scores were greatly due to appropriate human interventions, e.g. beach nourishment and dune restoration works. Classes 3 to 5 (the latter having very poor scenery), included sites with low scores for natural parameters. For these sites, coastal managers can do little to alleviate scenic impact, apart from addressing the human parameters, where improvement is possible, e.g. by litter removal together with the present chaotic protective structures

Risk-based prioritization of pharmaceuticals in the natural environment in Iraq

Numerous studies have demonstrated the occurrence of pharmaceuticals in the natural environment, raising concerns about their impact on non-target organisms or human health. One region where little is known about the exposure and effects of pharmaceuticals in the environment is Iraq. Due to the high number of pharmaceuticals used by the public health sector in Iraq (hospitals and care centres) and distributed over the counter, there is a need for a systematic approach for identifying substances that should be monitored in the environment in Iraq and assessed in terms of environmental risk. In this study, a risk-based prioritization approach was applied to 99 of the most dispensed pharmaceuticals in three Iraqi cities, Baghdad, Mosul and Basrah. Initially, information on the amounts of pharmaceuticals used in Iraq was obtained. The top used medicines were found to be paracetamol, amoxicillin and metformin with total annual consumption exceeding 1000 tonnes per year. Predicted environmental concentrations (PECs) and predicted no-effect concentrations (PNECs), derived from ecotoxicological end-points and effects related to the therapeutic mode of action, were then used to rank the pharmaceuticals in terms of risks to different environmental compartments. Active pharmaceutical ingredients used as antibiotics, antidepressants and analgesics were identified as the highest priority in surface water, sediment and the terrestrial environment. Antibiotics were also prioritized according to their susceptibility to kill or inhibit the growth of bacteria or to accelerate the evolution and dissemination of antibiotic-resistant genes in water. Future work will focus on understanding the occurrence, fate and effects of some of highly prioritized substances in the environment

Targeting neuroinflammation for therapeutic intervention in neurodegenerative pathologies: A role for the peptide analogue of thymulin (PAT)

Introduction: Inflammation has a vital task in protecting the organism, but when deregulated, it can have serious pathological consequences. The central nervous system (CNS) is capable of mounting immune and inflammatory responses, albeit different from that observed in the periphery. Neuroinflammation, however, can be a major contributor to neurodegenerative diseases and constitute a major challenge for medicine and basic research. Areas covered: Both innate and adaptive immune responses normally play an important role in homeostasis within the CNS. Microglia, astrocytes and neuronal cells express a wide array of toll-like receptors (TLR) that can be upregulated by infection, trauma, injuries and various exogenic or endogenic factors. Chronic hyper activation of brain immune cells can result in neurotoxic actions due to excessive production of several pro-inflammatory mediators. Several studies have recently described an important role for targeting receptors such as nicotinic receptors located on cells in the CNS or in other tissues for the control of inflammation. Expert opinion: Thymulin and its synthetic peptide analogue (PAT) appear to exert potent anti-inflammatory effects at the level of peripheral tissues as well as at the level of the brain. This effect involves, at least partially, the activation of cholinergic mechanisms. © 2012 Informa UK, Ltd

Picoliter drop-on-demand dispensing for multiplex liquid cell transmission Electron microscopy

Liquid cell transmission electron microscopy (LCTEM) provides a unique insight into the dynamics of nanomaterials in solution. Controlling the addition of multiple solutions to the liquid cell remains a key hurdle in our ability to increase throughput and to study processes dependent on solution mixing including chemical reactions. Here, we report that a piezo dispensing technique allows for mixing of multiple solutions directly within the viewing area. This technique permits deposition of 50 pL droplets of various aqueous solutions onto the liquid cell window, before assembly of the cell in a fully controlled manner. This proof-of-concept study highlights the great potential of picoliter dispensing in combination with LCTEM for observing nanoparticle mixing in the solution phase and the creation of chemical gradients