Water Quality Assessment of Sager Creek Utilizing Physiochemical Parameters and a Family-Level Biotic Index

An annual rapid bioassessment and physiochemical survey of Sager Creek in Northwest Arkansas was conducted. Sager Creek is a first to second order stream that flows through the city of Siloam Springs, AR. Invertebrate collections and water samples were collected at three different reaches, with the most downstream reach being below the effluent of the Siloam Springs Wastewater Treatment Plant. Benthic arthropods were collected, identified, and counted to produce a family-level biotic index and a family-level index of diversity. Statistical analysis revealed that these indices were significantly different for the effluent- influenced reach. However, this difference could not be correlated to any measured physiochemical parameter

Persistence of Urban Stream Syndrome Effects from Point Source and Non-Point Source Pollutants

In a previous study, Sager Creek, a small 1st-3rd order stream in northwest Arkansas was shown to be negatively impacted by urban land usage within the watershed, producing a stream that exhibited several indicators of urban stream syndrome. This included (1) physical disturbances: increases in impervious surfaces in the watershed, dams built across the stream, and alteration of the natural stream flow through the construction of retaining walls, (2) chemical disturbances: increases in electrical conductivity (EC) and total dissolved solids (TDS) as well as elevated PO4 levels (3) and biological disturbances: low populations of pollution intolerant macroinvertebrate species and high populations of pollution tolerant species. It could be hypothesized that these negative impacts could be mitigated by both biological and physiochemical remediation processes downstream from the effluent of the Siloam Springs Wastewater Treatment Plant (SSWTP), the most heavily effected of the previous study sites. A three-year investigation to test this hypothesis was completed. Utilizing physiochemical properties and biological assessments, four stream reaches, two in the previous research site and two downstream, were assessed for negative urban impact. Some acquired data supported the hypothesis that negative effects are mitigated downstream, particularly a lowering of EC and TDS levels and an increase in macroinvertebrate diversity. However, a larger amount of data, including mean water temperature, total water flow, pH, dissolved O2 and NO3 levels and mean Family-level Biotic Indices supported the null hypothesis that reaches above, at and, below the SSWTP were all equivalent in investigated physiochemical parameters and biological indicators

Tax and benefit changes: who wins and who loses?

* Tax and benefit changes implemented by Labour since 1997 will have a net cost to the exchequer of around £2.2 billion in 2005-06. The average (mean) impact of this small net giveaway is to raise household disposable incomes by £1.69 a week or 0.4%. The biggest proportionate gains are in the 2nd poorest tenth of the population, whose disposable incomes are increased by 11.4%, while the richest tenth fare worst, with a cut in income of 3.7%. * Tax and benefit reforms since 1997 have clearly been progressive, benefiting the less well-off relative to the better-off. Reforms in the second term - while less generous on average - were more progressive than those in the first, with the poorest faring better. * Increases in council tax above inflation since 1997 will raise £5.8 billion in 2005-06, net of council tax benefit. This outweighs the giveaway by central government, and leaves households overall £2.85 a week worse off on average, equivalent to 0.6% of their disposable incomes. The increase in council tax is regressive, except for the poorest fifth of the population, who are partially protected from the rises by council tax benefit

The distributional effects of tax and benefit reforms since 1997

Tax and benefit changes under Labour to date will have a net cost to the exchequer of around £1.1 billion in 2005–06. This is the difference between a large set of changes raising around £57.2 billion and a slightly larger set of changes costing £58.3 billion. Tax and benefit reforms implemented in Labour’s first term cost a net £4.8 billion, while those since 2001 have raised a net £3.7 billion. The average impact of the £1.1 billion tax and benefit giveaway since 1997 is to raise household disposable incomes by £0.84 a week or 0.2%. The biggest proportionate gains are in the second-poorest tenth of the population, whose disposable incomes are increased by 10.8%, while the richest tenth fare worst, with a cut in income of 5.1%. Tax and benefit reforms since 1997 have clearly been progressive, benefiting the less-well-off relative to the better-off. Reforms in the second term – while less generous on average – were more progressive than those in the first, with the poorest faring better. Increases in council tax above inflation since 1997 will raise a net £5.8 billion for local government in 2005–06, net of council tax benefit. This outweighs the £0.84 a week net giveaway per household by central government and leaves households overall £3.62 a week worse off on average. The increase in council tax is regressive, except for the poorest fifth of the population (thanks to council tax benefit). But the impact of council tax on the relative distribution of income is modest, leaving the overall progressive pattern of tax and benefit changes since 1997 intact

Study of fuel cell on-site, integrated energy systems in residential/commercial applications

Three building applications were selected for a detailed study: a low rise apartment building; a retail store, and a hospital. Building design data were then specified for each application, based on the design and construction of typical, actual buildings. Finally, a computerized building loads analysis program was used to estimate hourly end use load profiles for each building. Conventional and fuel cell based energy systems were designed and simulated for each building in each location. Based on the results of a computer simulation of each energy system, levelized annual costs and annual energy consumptions were calculated for all systems

By protecting against cutaneous inflammation, epidermal pigmentation provided an additional advantage for ancestral humans.

Pigmentation evolved in ancestral humans to protect against toxic, ultraviolet B irradiation, but the question remains: "what is being protected?" Because humans with dark pigmentation display a suite of superior epidermal functions in comparison with their more lightly pigmented counterparts, we hypothesized and provided evidence that dark pigmentation evolved in Africa to support cutaneous function. Because our prior clinical studies also showed that a restoration of a competent barrier dampens cutaneous inflammation, we hypothesized that resistance to inflammation could have provided pigmented hominins with yet another, important evolutionary benefit. We addressed this issue here in two closely related strains of hairless mice, endowed with either moderate (Skh2/J) or absent (Skh1) pigmentation. In these models, we showed that (a) pigmented mice display a markedly reduced propensity to develop inflammation after challenges with either a topical irritant or allergen in comparison with their nonpigmented counterparts; (b) visible and histologic evidence of inflammation was paralleled by reduced levels of pro-inflammatory cytokines (i.e., IL-1α and INFα); (c) because depigmentation of Skh2/J mouse skin enhanced both visible inflammation and pro-inflammatory cytokine levels after comparable pro-inflammatory challenges, the reduced propensity to develop inflammation was directly linked to the presence of pigmentation; and (d) furthermore, in accordance with our prior work showing that pigment production endows benefits by reducing the surface pH of skin, acidification of albino (Skh1) mouse skin also protected against inflammation, and equalized cytokine levels to those found in pigmented skin. In summary, pigmentation yields a reduced propensity to develop inflammation, consistent with our hypothesis that dark pigmentation evolved in ancestral humans to provide a suite of barrier-linked benefits that now include resistance to inflammation

Hybrid simulation modeling of hoist down-peak operations in construction sites

The down-peak period is an important aspect of hoist operations in construction projects. To make the vertical transportation service more efficient, the operation parameters of down-peak should be modeled precisely in the process of planning. A simulation model is developed to analyze the operations of elevator in down-peak. The model incorporates hybrid use of discrete-event simulation and agent-based modeling to provide a robust methodology to analyze the two most important parameters for elevator operation planning: time spent and average waiting time. The developed model is validated under several conditions, and its usage is expanded to random situations