Multiyear Performance of a Pervious Concrete Infiltration Basin BMP

The use of infiltration storm-water best management practices (BMPs) has become a more commonly used approach as a means of reducing postdevelopment runoff volumes in many areas throughout the United States. Although studies regarding the performance of infiltration BMPs are emerging, much remains to be learned about their design, construction, and operation. The increase in knowledge will improve the performance and longevity of these BMPs. The performance of one such infiltration basin over a 2-year cycle is presented in this paper. The study site is a pervious concrete infiltration basin BMP built in 2002 in a courtyard common area at Villanova University. The system consists of three linked infiltration beds lined with geotextile filter fabric, filled with coarse aggregate, and overlaid with pervious concrete. The natural soil beneath the infiltration BMP is a silty sand. The BMP is extensively instrumented to facilitate water quantity and quality research. Both water-quantity and -quality results are presented. The water-quantity analysis showed that the performance of the basin was directly related to its infiltration characteristics. The infiltration rate of the silty sand is cyclic, with higher rates during warmer periods and lower rates during colder periods. The water quality analysis investigated the pollutant reduction for chloride, copper, nitrogen, and phosphorus from the inlet to the surface-water outlet of the structure, as well as differences in pollutant concentration levels between the basin, surrounding ground, and varying soil layer elevations beneath the basin. In general, the pollutant reduction to the surface waters was greater than 90% from inlet to outlet, primarily influenced by the infiltration of the storm water into the natural soils below the BMP. The pollutant concentration of the infiltrating runoff was found to be higher than expected in the area adjacent to the bed when compared to concentration levels found at a similar depth beneath the infiltration bed. Comparison of pollutant concentration levels, as the water moved from within the storage bed to the soil beneath the bed, were shown to vary, with statistical differences found for mean concentration levels of both pH and copper levels; and no statistical differences were found for conductivity, total phosphorous, and chloride at each elevation.     

Decoupling climate-policy objectives and mechanisms to reduce fragmentation

ABSTRACT

The efficacy of climate-change mitigation policy within the building sector is examined in terms of how fragmentation can limit the extent of mitigation actions that can be achieved in a timely manner. The policy and regulatory context for the building industry is examined in relation to the policy context for solutions and recommendations that will work for all parties. Based on this analysis, two substantive recommendations are made for improved policy design. Firstly, a decoupling of policy objectives and policy mechanisms is needed so that the policy-taking stakeholders (in design, development and construction) can reduce energy use in buildings more effectively. Secondly, policy-taking stakeholders need an explicit and diverse system in order to advocate for policy objectives. The major aspect of this work is the development of a new conceptual framework that ties together these recommendations into a continuous process of policy-making and policy-taking. This framework demonstrates an idealized system that operates simultaneously top down and bottom up, and the development of policy objectives is influenced by stakeholders of all kinds to further the goals of an energy-efficient, low-carbon built environment.     

Two-way Bayesian hierarchical phylogenetic models: An application to the co-evolution of gp120 and gp41 during and after enfuvirtide treatment

Enfuvirtide (ENF) is a fusion inhibitor that prevents the entry of HIV virions into target cells. Studying the characteristics of viral evolution during treatment and after a treatment interruption can lend insight into the mechanisms of viral evolution and fitness. Although interruption of anti-HIV therapy often results in rapid emergence of an archived “wild-type” virus population, previous work from our group indicates that when only ENF is interrupted, viral gp41 continues to evolve forward and resistance mutations are lost due to back-mutation and remodeling of the envelope protein. To examine the co-evolution of gp120 and gp41 during ENF interruption we extend the Bayesian Hierarchical Phylogenetic model (HPM). Current HPMs enforce conditional independence across all outcomes while biologically all gene regions within a patient should return the same tree unless recombination confers an evolutionary selective advantage. A two-way-interaction HPM is proposed that provides middle ground between these two extremes and allows us to test for differences in evolutionary pressures across gene regions in multiple patients simultaneously. When the model is applied to a well-characterized cohort of HIV-infected patients interrupting ENF we find that across patients, the virus continued to evolve forward in both gene regions. Overall, the hypothesis of independence over dependence between the gene regions is supported. Models that allow for the examination of co-evolution over time will be increasingly important as more therapeutic classes are developed, each of which may impact other through novel and complex mechanisms.     

Photokatalytische Bildung von Wasserstoff aus Thiolen in Gegenwart von Vitamin B12-Modellverbindungen mit Azid als photochemischem Opferliganden

Photocatalytic Hydrogen Formation from Thioles in the Presence of Vitamin-B₁₂ Model Complexes with Azide as Photochemical Sacrificial Ligand The photolysis of [N₃Co(chelat)B] complexes ( 1–3 ) (chelat = dimethylglyoxime, dmg; N,N′-o-phynylenebis(salicylidenimine), salphen; N,N′-ethylene-bis(salicylidenimine), salen; B = pyridine) leads by homolytic cleavage of the Co–N₃ bond to both coordinatively unsaturated cobalt(II) chelates [Co(chelat)B] and N₃ ligand radicals that undergo fast decay to dinitrogen. The photolysis of the cobalt (III) complexes 1–3 in the presence of thiophenole and other thioles proceeds catalytically and yields the corresponding disulphides and dihydrogen. The mechanism of this photocatalytic generation of dihydrogen is due to the catalytic activity of the coordinatively unsaturated cobalt(II) species formed photochemically. A photocatalytic cycle is proposed describing the generation of hydrogen. Possible photochemical and thermal steps of that cycle are discussed.     

Maternal Fructose Intake Causes Developmental Reprogramming of Hepatic Mitochondrial Catalytic Activity and Lipid Metabolism in Weanling and Young Adult Offspring

Excess dietary fructose is a major public health concern, yet little is known about its influence on offspring development and later-life disease when consumed in excess during pregnancy. To determine whether increased maternal fructose intake could have long-term consequences on offspring health, we investigated the effects of 10% w/v fructose water intake during preconception and pregnancy in guinea pigs. Female Dunkin Hartley guinea pigs were fed a control diet (CD) or fructose diet (FD; providing 16% of total daily caloric intake) ad libitum 60 days prior to mating and throughout gestation. Dietary interventions ceased at day of delivery. Offspring were culled at day 21 (D21) (weaning) and at 4 months (4 M) (young adult). Fetal exposure to excess maternal fructose intake significantly increased male and female triglycerides at D21 and 4 M and circulating palmitoleic acid and total omega-7 through day 0 (D0) to 4 M. Proteomic and functional analysis of significantly differentially expressed proteins revealed that FD offspring (D21 and 4 M) had significantly increased mitochondrial metabolic activities of β-oxidation, electron transport chain (ETC) and oxidative phosphorylation and reactive oxygen species production compared to the CD offspring. Western blotting analysis of both FD offspring validated the increased protein abundances of mitochondrial ETC complex II and IV, SREBP-1c and FAS, whereas VDAC1 expression was higher at D21 but lower at 4 M. We provide evidence demonstrating offspring programmed hepatic mitochondrial metabolism and de novo lipogenesis following excess maternal fructose exposure. These underlying asymptomatic programmed pathways may lead to a predisposition to metabolic dysfunction later in life.