Upstream Inputs Research Articles

Probabilistic analysis of risks to us drinking water intakes from 1,4-dioxane in domestic wastewater treatment plant effluents

The risks of 1,4-dioxane (dioxane) concentrations in wastewater treatment plant (WWTP) effluents, receiving primarily domestic wastewater, to downstream drinking water intakes was estimated using distributions of measured dioxane concentrations in effluents from 40 WWTPs and surface water dilution factors of 1323 drinking water intakes across the United States. Effluent samples were spiked with a d8 -1,4-dioxane internal standard in the field immediately after sample collection. Dioxane was extracted with ENVI-CARB-Plus solid phase columns and analyzed by GC/MS/MS, with a limit of quantification of 0.30 μg/L. Measured dioxane concentrations in domestic wastewater effluents ranged from <0.30 to 3.30 μg/L, with a mean concentration of 1.11 ± 0.60 μg/L. Dilution of upstream inputs of effluent were estimated for US drinking water intakes using the iSTREEM model at mean flow conditions, assuming no in-stream loss of dioxane. Dilution factors ranged from 2.6 to 48 113, with a mean of 875. The distributions of dilution factors and dioxane concentration in effluent were then combined using Monte Carlo analysis to estimate dioxane concentrations at drinking water intakes. This analysis showed the probability was negligible (p = 0.0031) that dioxane inputs from upstream WWTPs could result in intake concentrations exceeding the USEPA drinking water advisory concentration of 0.35 μg/L, before any treatment of the water for drinking use.

Effects of capacity constraints on mixed duopoly

This paper highlights the mixed duopoly substitutable product with an upstream input subject to capacity constraints. The effects of capacity constraints on the mixed economy are captured. Firstly, the degree of public ownership improves the firm size difference, the price difference, the price dispersion and consumer surplus, while it reduces the price and the second firm’s profits. Secondly, the efficiency difference reduces the firm size difference, the price difference and the price dispersion. Finally, under scarce capacity, the relationship between the total capacity and, the firm size difference, the price difference and the price dispersion, depends on the efficiency of the two firms.

Wg and Wnt4 provide long-range directional input to planar cell polarity orientation in Drosophila

Planar cell polarity (PCP) is cellular polarity within the plane of an epithelial tissue or organ. PCP is established through interactions of the core Frizzled(Fz)/PCP factors and although their molecular interactions are beginning to be understood, the upstream input providing directional bias/polarity axis remains unknown. Among core PCP genes, Fz is unique as it regulates PCP both cell-autonomously and non-autonomously, with the extra-cellular domain of Fz acting as a ligand for Van-Gogh (Vang). We demonstrate in Drosophila wings that Wg and dWnt4 provide instructive regulatory input for PCP axis determination, establishing polarity axes along their graded distribution and perpendicular to their expression domain borders. Loss-of-function studies reveal that Wg/dWnt4 act redundantly in PCP determination. They affect PCP by modulating the intercellular interaction between Fz and Vang, which is thought to be a key step in setting up initial polarity, thus providing directionality to the PCP process.

MODEL LEMBAGA KEUANGAN MIKRO POLA GRAMEEN BANK UNTUK PENGUATAN KLASTER (di Kab. Brebes dan Kota Surakarta)

Strengthening of the cluster is affected by the factors of production, including capital. The goal is : to identify the structure of the chain of activites, capital reqirements, financial institutions and role models pattern of Microfinance Institution Grameen for strengthening clusters. Research sites in coastal areas (clusters of seaweed in Brebes) and the highlands (batik cluster in Surakarta). The results, that : Characteristics of clusters varies influent by local socio cultural factors. Structure activity of clusters is different. Capital requirements are relatively small, less than Rp.5 million as much as 80,00 %. Non-formal financial institutions nearby PNPM Mandiri. Influencing factors : management, solidarity, and loyalty members and mutual trust (mutual trust in group). Model financial institutions the right pattern of Grameen Bank is a form of cooperative (owned and affiliated members of the cluster). The working principle of Grameen Bank modified into AD/ART of cooperative. Cluster development is inseparable from the aspect chain upstream (input) – processing (industrial) and downstream (marketing) and involving cross-sector and private. Agricultural institutions preparing raw materials, facilitating the establishment of cooperative and capital stimulants. The Planning Board Institution designing the strengthening of institutions, management and technical skills of entrepreneurship.

Chemical and Microbial Contamination Baseline in the Saguenay–St. Lawrence Marine Park (Eastern Canada): Concentrations and Fluxes From Land-Based Sources

Stretching halfway between the Canadian Great Lakes and the Atlantic Ocean, the Saguenay-St. Lawrence Marine Park is subject to environmental issues being exposed to untreated or uncontrolled point and non-point sources of anthropogenic contamination. This article provides a first estimation of chemical and microbial contamination entering the marine park from the discharges of local municipal effluents and the inputs of tributaries in the summer period. Suspended particulate matter (SPM), nutrients, particulate carbon (PC) and nitrogen, trace metals, and fecal coliform bacteria were determined in surface brackish waters at upstream boundaries, in freshwater of 11 tributaries, and in nine sewage effluents from small communities settled along the marine park. Most tributaries have SPM < 10 mg L(-1) and contributed to a total of ~47 tons day(-1), thus representing a small proportion of daily SPM transported by Saguenay River (200 tons day(-1)) and St. Lawrence River (6.3 × 10(3) tons day(-1)). As expected, untreated sewage effluents showed high fecal contamination (0.2-6.0 × 10(6) CFU 100 mL(-1)), high NO x levels (4-33 μmol L(-1)) and high concentrations of particulate organic carbon (7-62 mg L(-1)). However, all tributaries had low coliforms (<230 CFU 100 mL(-1)), low PC (0.3-1.1 mg L(-1)), and low nutrients (NO(x) < 3.3 μmol L(-1)), with the exception of the Moulin-à-Baude River, a small tributary (2.3 × 10(5) m(3) day(-1)) clearly contaminated by human activities. Detailed analysis of 14 metals and metalloids in SPM did not show any clear contamination trend between sewage effluents and tributaries, except for Grandes-Bergeronnes River, where most trace metals appeared to be greater than for other rivers. Regarding global inputs, results showed that despite their relatively high pollutants load, inputs from local sewages and small tributaries remained minor contributors compared with upstream inputs, i.e., Saguenay River and St. Lawrence River. However, we illustrate that some local hydrodynamic factors in bays and inlets must be taken into account when evaluating risks associated with sewage discharges.

Simulating different upstream coupling conditions on an artificial trombone player system using an active sound control approach

Recent research suggests that the ability to finely tune vocal-tract resonances during trombone playing may constitute an important aspect of performance expertise. Artificial player systems, designed to reproduce the behavior of a real player, often neglect this component by not providing any control of upstream resonances. However, they offer great experimental platforms for quantitative studies on sound production mechanisms, allowing independent adjustment of certain control parameters. An active sound control method was designed to improve high tone support and investigate different conditions of coupling between the artificial lips, the downstream air-column, and the upstream cavity during sustained tones played by an artificial valve-trombone player system. Upstream input impedance at the fundamental frequency was controlled through real-time adjustment of the phase and amplitude ratio between the acoustic pressure generated on both sides of the lips. The phase difference between the upstream and downstream pressures was swept linearly while maintaining different conditions of upstream energy and fixed trombone fingering. Observations during this procedure included: (1) significant fundamental frequency variations in the neighborhood of a downstream impedance peak; and (2) variation of the downstream energy and optimal phase tuning with regard to the mechanical efficiency of the lip-valve system suggested at the energy maximum.

Spatial and Temporal Variability of the CO2 Fluxes in a Tropical, Highly Urbanized Estuary

The spatial and temporal variations of the flux of CO2 were determined during 2007 in the Recife estuarine system (RES), a tropical estuary that receives anthropogenic loads from one of the most populated and industrialized areas of the Brazilian coast. The RES acts as a source of nutrients (N and P) for coastal waters. The calculated CO2 fluxes indicate that the upstream inputs of CO2 from the rivers are largely responsible for the net annual CO2 emission to the atmosphere of +30 to +48 mmol m−2 day−1, depending on the CO2 exchange calculation used, which mainly occurs during the late austral winter and early summer. The observed inverse relationship between the CO2 flux and the net ecosystem production (NEP) indicates the high heterotrophy of the system (except for the months of November and December). The NEP varies between −33 mmol m−2 day−1 in summer and −246 mmol m−2 day−1 in winter. The pCO2 values were permanently high during the study period (average ~4,700 μatm) showing a gradient between the inner (12,900 μatm) and lower (389 μatm) sections on a path of approximately 30 km. This reflects a state of permanent pollution in the basin due to the upstream loading of untreated domestic effluents (N/P = 1,367:6 μmol kg−1 and pH = 6.9 in the inner section), resulting in the continuous mineralization of organic material by heterotrophic organisms and thereby increasing the dissolved CO2 in estuarine waters.

Groundwater–surface water exchange in a mangrove tidal creek: Evidence from natural geochemical tracers and implications for nutrient budgets

Assessing submarine groundwater discharge (SGD) in mangroves can be challenging due to the complex, heterogeneous nature of sediments and temporally dynamic water flows. Here, we use natural tracers (i.e., radon and radium isotopes) to quantify groundwater–surface water exchange in a mangrove tidal creek at the ecosystem scale, and to assess whether SGD was a source of dissolved inorganic and organic nutrients to the nearby estuary. Hourly sampling for over 27h in the winter and 30h in the summer revealed clear tidal trends for 222Rn, 224Ra, 223Ra, 226Ra, dissolved oxygen, ammonium, and dissolved organic nitrogen (DON) in a mangrove tidal creek with no upstream freshwater inputs (Kangaroo Island, Southern Moreton Bay, Australia). Nitrate, phosphate and dissolved organic phosphorus (DOP) did not show a clear tidal trend. A mass balance revealed that 5–12% of the tidal prism volume infiltrated the sediments and drained back to the creek at low tide. Groundwater exchange accounted for nearly all the ammonium and about 30% of the DON exported by the creek. Crab burrows were a major factor influencing groundwater exchange in this tidal creek. A detectable 226Ra (half-life of 1600years) enrichment in the creek at low tide could only be explained by the construction of new crab burrows during each tidal cycle exposing old sediments. Overall, the concentration of groundwater tracers and nutrients was higher in the summer most likely due to increased crab activity and organic matter degradation in the warmer months. Respiration of belowground organic matter apparently released nitrogen to groundwater seeping out from the creek bank at low tide and increased N:P ratios of surface water draining from mangroves. Therefore, we hypothesize that outwelling from mangroves with high SGD may influence the composition of downstream biological communities by altering estuarine N or P limitation conditions.

Buyer Groups, Antitrust and Outsiders

A buyer group is a subset of downstream firms that pool their demand for an upstream input to negotiate a better deal with suppliers. This study develops a simple model that shows how a buyer group changes market behaviour, focusing on the impact on downstream firms outside the buyer group. This impact critically depends on whether or not the buyer group and the supplier can write a contract contingent on the market price paid by outsiders. With contingent contracts, the price paid by firms outside the buyer group rises and their profits fall. If such contracts are infeasible, possibly due to legal concerns, the market price is lower after the buyer group forms. These results raise issues for antitrust authorities in Australia, Europe, the USA and elsewhere who evaluate buyer‐group agreements. We extend the model to consider the situation where a supplier can commit in advance to the market price. In this situation, the bargaining power of the buyer group becomes relevant with the market price inversely related to this bargaining power. We illustrate our results with a simple example.

Signaling inputs to invadopodia and podosomes

Remodeling of extracellular matrix (ECM) is a fundamental cell property that allows cells to alter their microenvironment and move through tissues. Invadopodia and podosomes are subcellular actin-rich structures that are specialized for matrix degradation and are formed by cancer and normal cells, respectively. Although initial studies focused on defining the core machinery of these two structures, recent studies have identified inputs from both growth factor and adhesion signaling as crucial for invasive activity. This Commentary will outline the current knowledge on the upstream signaling inputs to invadopodia and podosomes and their role in governing distinct stages of these invasive structures. We discuss invadopodia and podosomes as adhesion structures and highlight new data showing that invadopodia-associated adhesion rings promote the maturation of already-formed invadopodia. We present a model in which growth factor stimulation leads to phosphoinositide 3-kinase (PI3K) activity and formation of invadopodia, whereas adhesion signaling promotes exocytosis of proteinases at invadopodia.

The Optimal Institutional Design of Vertically Related Markets with Unknown Upstream Costs

This paper examines the design of vertically related industries with a regulated monopolistic upstream input and competitive downstream activities. Two institutional patterns are investigated. Ownership separation entails full unbundling between upstream and downstream activities. Legal separation allows a downstream firm to own the upstream monopolist but requires the two entities to be legally unbundled so that each service is stand-alone profitable and only upstream profits are regulated. Under regulatory limited information about upstream costs, the legally separated monopolist exhibits countervailing incentives to manipulate costs. This alleviates the regulator’s control problem and yields higher welfare than ownership separation.

Impacts of composite wastewater on a Pampean stream (Argentina) and phytoremediation alternative with Spirodela intermedia Koch (Lemnaceae) growing in batch reactors

Poultry slaughterhouses are producing increasing amounts of solid organic by-products and waste in Argentina. The objectives of this study are to assess the impacts of wastewater, mainly composed of poultry slaughterhouse effluent, on a Pampean stream and to evaluate the convenience of phytoremediation alternative with Spirodela intermedia. Impacts over La Choza stream (Buenos Aires, Argentina) were evaluated by means of physical and chemical characterization of the water upstream and downstream input. Nutrients and total suspended solids increased downstream of the open channel outlet. A bioassay was performed in order to evaluate the role of S. intermedia in wastewater treatment. Two treatments were performed in batch reactors during 144 h (6 days), with (treatment A) and without (treatment B) the addition of S. intermedia. Water samples were taken at 8, 24, 48, 96 and 144 h after the start of the assay for the determination of ammonium, nitrite, nitrate, soluble reactive phosphorus and total phosphorus. Since removal rates of ammonium and total phosphorus were significantly higher in treatment A than in treatment B and the nitrification process was highly increased in treatment A, then the species could be used for the phytoremediation of composite wastewater.

Basement Groundwater as a Complementary Resource for Overexploited Stream-Connected Alluvial Aquifers

The use of groundwater from alluvial aquifers largely affects stream discharge by capturing the stream resources. This affects hydrological processes and riparian biodiversity. In this study, complementary water resources are investigated in an effort to ease human pressure on alluvial systems and, eventually, on stream-aquifer relationships. Discharge and hydrochemical data along a 5 km reach of the Tordera River (NE Spain) provide evidence that groundwater fluxes, associated with a regional hydrogeological system related to the basement fracture network, contribute to alluvial recharge and to stream flow. End-member mixing analysis considering upstream discharge, groundwater flows, and human inputs to the stream as major flow sources shows that regional basement groundwater fluxes are responsible for as much as 20 % of the total discharge, which also explains unexpected rises in stream flow. This suggests a possible new approach to local water resources planning, indicating that conjunctive use might actually be feasible.

Pathway-based analysis of mutation impact

Genomic damage plays an important role in cancer onset and progression. But how exactly do mutations, copy number changes, and epigenetic events affect the wiring of otherwise normal-functioning cellular pathways? Genomic probing with technologies such as RNA sequencing, copy number profiling, and DNA promoter methylation arrays are providing unprecedented views of cells. Uncovering predictive models from these datasets to shed light on key disrupted pathways in cancer is a major challenge that could offer breakthroughs for personalized medicine. I'll describe a new pathway-based strategy that gives novel insight into the functional impact of mutations in particular genes. The major mechanism by which cancer arises is through somatic mutations. Individual tumors can contain hundreds to thousands of mutations. It is critical to distinguish mutations that have an important role defining the cancer - driver mutations - from mutations that are unimportant to the tumor - passenger mutations. A pathway-based approach is able to detect a shift in the downstream effects of an altered gene compared to what is expected from its upstream regulatory input. Application to several datasets across multiple tissues revealed several important driver mutations even among rarely mutated genes. Thus, pathway analysis shows promise in differentiating driver and passenger events that will increase our understanding of cancer disease mechanisms, which can help identify novel targets for treatment.

Strategic Choice of Channel Structure in an Oligopoly

The traditional wisdom holds that the benefits of a decentralized channel structure arise from downstream competitive relationships. In contrast, in their 2007 paper in the Accounting Review, Arya and Mittendorf show that the value of decentralization can also come from the upstream relationship when the downstream firms convey internal strife (decentralization) to an upstream input supplier. This paper demonstrates that the Arya and Mittendorf result continues to hold irrespective of the market structure of the upstream input market. However, if the upstream market is monopolized and the monopoly supplier follows a uniform price policy, decentralization may not result from the centralization–decentralization game. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Two-stage report generation in long-reach EPON for enhanced delay performance

Long-reach passive optical networks (LR-PONs), as a part of the next generation PON technologies, aim at combining the capacity of metro and access networks so that the telecommunication network topology is simplified and the operational cost is reduced. However, in order to eliminate the delay performance degradation introduced by long propagation distance, LR-PONs call for bandwidth distribution schemes that are different than the existing schemes for conventional PONs. In this paper, we propose a new bandwidth distribution approach which employs a two-stage buffering mechanism at the ONUs and adopts the reduced delay advantage of multi-thread polling. REPORT generator at an ONU generates the requests by using an adaptive burst assembly process. According to the proposed scheme, ONUs maintain time threshold and size threshold values for the upstream input queues. Upon receipt of a GATE message, each ONU runs an adaptive burst assembly procedure to set the appropriate time and size thresholds and determines the bandwidth request of the REPORT message. We evaluate our proposed bandwidth distribution scheme by simulations for the ONU-OLT distances of 20km and 100km. The simulation results confirm that consolidation of multi-thread polling and two-stage buffering enhances the delay performance of long-reach EPON (LR-EPON). Furthermore, under heavy loads, the proposed scheme leads to high utilization of the upstream channel.

Quality and Environmental Regulation: Verifying Compliance along the Supply Chain

Among the factors providing incentives to monitor the behaviour of input suppliers are the regulatory requirements to which downstream firms are subject. We develop a formal economic model to examine the relationship between the strictness of the regulatory environment and downstream firms' incentives to act as inspectors of their sub-contractors. We consider the interaction between a downstream producer and an upstream input supplier. The downstream chooses the probability with which to monitor the upstream's compliance and the upstream chooses a compliance level which determines compliance of the end product with quality or environmental regulation. We find that the strictness of regulation affects the downstream's monitoring strategy in combination with the level of quality or environmental standards. If the standards are sufficiently low then the strictness of regulation increases incentives to monitor the upstream. Contrary, if the standards are sufficiently high then the pressure on the downstream to monitor the upstream is relaxed and the strictness of regulation decreases incentives to monitor. We argue that the strictness of regulation should not be treated in isolation as a factor determining the choice of downstream firms to monitor their input suppliers.

Rising household diesel consumption in the United States: A cause for concern? Evidence on asymmetric pricing

Papers in the literature have thus far overlooked the projected increase in U.S. diesel car share when looking at asymmetries in petroleum pricing. This paper addresses this issue by comparing retail gasoline and diesel prices in order to see whether they rise faster than they fall given the price of their upstream input, crude oil. This phenomenon has been termed in the literature as “Rockets and Feathers.” We apply the threshold vector error correction model (TVECM) of Hansen and Seo (2002) which has not yet been applied in the literature. We account for the 2008 structural break to crude oil and petroleum prices by splitting the sample using evidence from the recent structural break unit root test of Kim and Perron (2009). Both markets seem to price symmetrically before the 2008 break, but we find evidence of asymmetric pricing after 2008 in diesel prices, and not in gasoline prices. Given that the diesel market is small relative to the gasoline market and therefore more open to price exploitation, the ongoing cost increases associated with the policy of switching to Ultra Low Sulphur diesel (ULSD) from 2006 to 2010 could be at the heart of this asymmetry. With this in mind, the U.S. Federal Trade Commission should monitor diesel prices as the market share grows, in order to ensure that consumers are not adversely affected.

A hydrological assessment of the November 2009 floods in Cumbria, UK

In November 2009, record-breaking rainfall resulted in severe, damaging flooding in Cumbria, in the north-west of England. This paper presents an analysis of the river flows and lake levels experienced during the event. Comparison with previous maxima shows the exceptional nature of this event, with new maximum flows being established at 17 river flow gauging stations, particularly on catchments influenced by lakes. The return periods of the flood peaks are estimated using the latest Flood Estimation Handbook statistical procedures. Results demonstrate that the event has had a considerable impact on estimates of flood frequency and associated uncertainty. Analysis of lake levels suggests that their record high levels reduced their attenuating effect, significantly affecting the timing and magnitude of downstream peaks. The peak flow estimate of 700 m3s–1 at Workington, the lowest station on the Derwent, was examined in the context of upstream inputs and was found to be plausible. The results of this study have important implications for the future development of flood frequency estimation methods for the UK. It is recommended that further research is undertaken on the role of abnormally elevated lake levels and that flood frequency estimation procedures in lake-influenced catchments are reviewed.

Duopoly competitions with capacity constrained input

This paper focuses on the duopoly substitutability product with an upstream input subjected to capacity constraints. The effects of capacity constraints are captured. Combining competition effect with constraint effect, some interesting conclusions are reached. First, the relationship between capacity constraints and firm size is addressed. We argue that the capacity constraints reduce market size difference and price difference under Cournot. Second, under the Stackelberg case, the existence of solution is proved, and Stackelberg competitions enlarge firm-size difference and price difference if the more efficient firm plays the leading position. When the weaker firm plays the leading position, the conclusions depend on the total capacity. Finally, under the Stackelberg case, when the stronger firm plays the leading position, the firm-size difference and price difference decrease with total input under capacity constraints, which is contrary to the conclusions under Cournot competitions.