Low Tier Research Articles

The consequences of using increasing block tariffs to price urban water

Increasing block tariffs (IBTs) are currently used to price urban water in many Australian mainland capitals and a great many cities worldwide. This paper provides a systematic analysis of the impact of the adoption of IBTs to price urban water under the common constraints of scarce supply and cost recovery. The key tools available to policymakers using IBTs are the volumetric rate in the low tier and the threshold level of that tier. This paper shows how variations in these tools influence (i) the fixed charge set by the firm, (ii) the deadweight loss from the IBT and (iii) the bill paid by customers for particular levels of demand. Our analysis suggests that IBTs are neither fair nor efficient. We propose a modification to IBTs that, while retaining their perception of fairness, results in the efficient allocation of urban water.

Mechanistic TK/TD-model simulating the effect of growth inhibitors on Lemna populations

A mechanistic combined toxicokinetic–toxicodynamic (TK/TD) and growth model for the aquatic macrophytes Lemna spp. has been developed. This model simulates the development of Lemna biomass under laboratory and environmental conditions. Growth of the Lemna population is simulated on basis of photosynthesis and respiration rates which are functions of environmental conditions, i.e., temperature, global radiation, N- and P-concentrations. The toxicodynamic sub-model describes the effects of growth-inhibiting substances by a respective reduction in the photosynthesis rate based on the Lemna spp. internal concentrations. Internal concentrations are calculated using a simple, one-compartment toxicokinetic model that considers the uptake of substances through the plant surface.The growth model was parameterised based on literature data while toxicokinetic and toxicodynamic parameters were determined by calibrating the model using substance specific effect data. Both the growth model and the toxicokinetic model were independently tested by comparing model predictions to observed data.In an exemplary case study, the model was applied to a risk assessment for the sulfonyl urea herbicide metsulfuron-methyl. This assessment was carried out for two standard scenarios used in European regulatory risk assessments for pesticides. Thereby, it was shown that the effect of transient concentration peaks of metsulfuron-methyl on Lemna populations is much lower than estimated in a low tier assessment considering the maximum surface water concentration and the EC50 obtained from the standard Lemna growth inhibition test. The model also predicts moderate effects for longer lasting exposures resulting from calculated drainage entries into the water body if the majority of the entry occurs during the cold season with no or slow growth of the plants.

The best method for dose escalation: Prostate brachytherapy

The best method for dose escalation: Prostate brachytherapy

A Simple Test to Identify the Boom and Bust of Housing Bubbles

The recent housing boom and bust in the United States was marked by large differences in the run-up and the subsequent decline of the housing prices both across metro areas and across market segments in the same area. One common observation in many metro areas is that the low-tier S&P Case-Shiller price indices realized the largest gains during the boom and saw the sharpest decline during the bust of the market.In this paper we propose a new time-series empirical test to identify housing bubble periods. Our test determines the dates of origin and burst of bubbles without market fundamentals: bubble periods are identified by the misalignment in the movements of the tiered price indices over time. Our empirical analysis is based on a theoretical model that explains why during a bubble prices of lower-tier houses tend to rise faster than prices of high-tier houses. For quite general specifications of the households’ utility function we show that, when given unrestricted access to credit, low income households take mortgages that constitute a larger share of their future expected income, pay higher interest rates, and are more likely to default given that their future income is uncertain. The main consequence of this household behavior is that the low tier price increases at a faster pace when households borrow funds to finance their home purchases and declines more sharply when lower income households start defaulting. We implement our test on 15 U.S. Metropolitan Statistical Areas during the most recent housing bubble.

PENGAWASAN TERHADAP PERATURAN KEPALA DAERAH

Decentralisation puts weigh in the dynamic of local government. As consequences of decentralization, local governments are entitled to enact local regulation in order to serve public services in the daily basis. Local regulation as the product of the Mayor of course does not stand alone. It is part of national legislative system which lay at the low tier of the hierarchy of laws. It should be work effectively and harmoniously with the system. By analyzing the nature of decentralization and the function of local legislation, it is essential to establish a good review mechanism for this legislative product. Different mechanism results in different consequences to the regulation. This article has analysed three mechanisms both preventive and represive; executive review which is done by the Governor and National Government; judicial review which is done by the Court and even political review which is exercised by the local representatives who act as balancing power to the local executive.Keywords: Peraturan Kepala Daerah, Executive Review, Judicial Review, Political Review

What Saved the Indian Banking System: State Ownership or State Guarantees?

AbstractThe global financial crisis which began in the fall of 2007 and progressively worsened in 2008, affected the Indian financial sector beginning only in 2008. While Indian financial firms have been fairly resilient compared with their global counterparts, we show that Indian private sector firms faced greater losses compared with public sector firms during the crisis period of 2008–09. We use a stock market‐based measure of systemic risk, marginal expected shortfall (MES), to determine the systemic risk contributed by each Indian financial firm for the period preceding the crisis (January–December 2007) and compare it to its realised returns during the crisis (January 2008–February 2009). Our results show that public sector firms outperformed private sector firms despite having greater systemic risk during the crisis. We conclude that investors rewarded Indian public sector firms with greater systemic risk while penalising private sector firms with similar risk. We attribute this finding to the explicit and implicit government backing of public sector banks. We find that riskier public sector banks with high ex ante systemic risk and low Tier 1 capital received greater capital support from the government.

P2-S2.20 The association study of job mobility and HIV/STI prevention in female sex workers of Hunan province, China

BackgroundThe job mobility of female sex workers (FSWs) is the working experience that keep low level status and no rising opportunity among all previous jobs before FSWs enter of commercial...

Design and evaluation of a two-tier peer-to-peer traffic information system

Decentralized traffic information systems realize real-time traffic information services without the need for a server infrastructure. However, existing systems rely on either the vehicular ad hoc network or application-layer peer-to-peer protocols over a broadband wireless network suffering from low lookup success rate, high lookup latency, and maintenance overhead of the P2P network. This article proposes a two-tier VANET/P2P architecture that exploits both VANET and P2P technology. In the low tier, vehicles form a VANET via intervehicle communication to exchange traffic information. On top of the VANET, a portion of the vehicles further establish a P2P overlay through a broadband wireless infrastructure to mitigate the disconnectivity problems of the VANET. Simulation results demonstrate that the two-tier architecture can significantly improve the lookup success rate compared to the single-tier VANET systems while reducing lookup latency and maintenance overhead compared to the single-tier P2P systems.

Topology Aggregation for Hierarchical Wireless Tactical Networks

Wireless tactical network (WTN) is the most important present-day technology enabling modern network centric warfare. It inherits many features from WMNs, since the WTN is based on existing wireless mesh networks (WMNs). However, it also has distinctive characteristics, such as hierarchical structures and tight QoS (Quality-of-Service) requirements. Little research has been conducted on hierarchical protocols to support various QoS in WMN. We require new protocols specifically optimized for WTNs. Control packets are generally required to find paths and reserve resources for QoS requirements, so data throughput is not degraded due to overhead. The fundamental solution is to adopt topology aggregation, in which a low tier node aggregates and simplifies the topology information and delivers it to a high tier node. The overhead from control packet exchange can be reduced greatly due to decreased information size. Although topology aggregation is effective for low overhead, it also causes the inaccuracy of topology information; thus, incurring low QoS support capability. Therefore, we need a new topology aggregation algorithm to achieve high accuracy. In this paper, we propose a new aggregation algorithm based on star topology. Noting the hierarchical characteristics in military and hierarchical networks, star topology aggregation can be used effectively. Our algorithm uses a limited number of bypasses to increase the exactness of the star topology aggregation. It adjusts topology parameters whenever it adds a bypass. Consequently, the result is highly accurate and has low computational complexity.

Cold‐start and chemical characterization of emissions from mobile sources in Mexico

In this work tailpipe and evaporative emissions from a set of normal and high emitter vehicle models, year 2006–2008 (low mileage) certified when new to meet the Tier 1 emission standard, were characterized for criteria pollutants (carbon monoxide, nitrogen oxides and hydrocarbons), and a suite of unregulated emissions including aliphatic and aromatic aldehydes, monocyclic aromatic compounds, 1,3 butadiene, n‐hexane and acrolein. Data were obtained under the three different driving conditions of the United States Federal Test Procedure, FTP‐75 cycle. High emissions of both regulated and unregulated pollutants were observed in the cold‐start phase of the driving cycle for low mileage Tier 1 normal and high emitters engines. Data were compared with results obtained for a set of MY >1992–2005 that included vehicles with no catalytic converters, Tier 0 and MY 2000–5 Tier 1 emission standard with high mileage. The calculated average cold‐start emissions for normal emitters in grams are 0.93, 8.21 and 1.06 for NMHC CO, and NOx, respectively for Tier 1 low mileage vehicles. The reductions in emissions for Tier 1 normal emitters are 76%, 56% and 56% for NMHC, CO and NOx, respectively, but 58%, 30% and 25% for the high emitters. Differences in emission can be ascribed to the mileage accumulation more than technological improvements. Cold‐start emissions account in the USA roughly 10% of emissions from gasoline‐powered vehicles. In Mexico the fractions are likely to be higher because one must account also for the contribution of Tier 0 and the running exhausts emissions of vehicles with no catalytic converters.

Body Fat Distribution, Waist Circumference and Body Mass Index in Permanent Seed Prostate Brachytherapy

Purpose: Recent studies have shown that obesity is associated with more aggressive prostate cancer variants and a higher prostate specific antigen (PSA) recurrence following prostatectomy. The aim of this study is to analyze the influence of body mass index (BMI) and the distribution of adipose tissue on clinical pretreatment variables and PSA evolution post 125I prostate brachytherapy. Materials and Methods: We studied 59 men with low risk or ‘low tier” intermediate risk (maximum one intermediate risk feature) prostate cancer who had undergone 125I radioactive seed implantation as monotherapy. Inclusion criteria were an absence of hormonal therapy or external beam radiotherapy, a minimum of 8 months of followup and at least 3 followup PSA values. We calculated the BMI (kg/m2), waist circumference and the quotient between visceral and subcutaneous fat (VF/SF) measured on computed tomography at the iliac crest level. To analyze the influence of anthropometric measures on post-brachytherapy PSA evolution, we divided the patients into 2 groups: 1) rapid PSA descent post-brachytherapy to <0.5 ng/mL in the first 12 months following brachytherapy (n = 28); 2) slow PSA descent post-brachytherapy to <0.50 ng/mL and a followup of ≥24 months (n = 23) or a PSA bounce of ≥0.50 ng/mL (n = 6). The influence of those anthropometric measures on pretreatment PSA, prostate volume and number of positive biopsies were calculated using Spearman correlation coefficient. Differences between the 3? post-brachytherapy outcome groups were analyzed using the Pearson chi-square and Fisher's exact test. Relative risk estimate was calculated to measure of the strength of the association between the presence of a factor and the occurrence of an event. All tests were two-tailed. Results: There was an influence of the different anthropometric measures on pretreatment characteristics; there was a positive correlation between VF/SF and the PSA before treatment (r = 0.282, p = 0.029); and waist circumference with the number of positive biopsies (r = 0.374, p = 0.004). VS/SF, BMI and waist circumference were not different between both post-brachytherapy PSA-outcome groups (p≥0.439). The following factors were associated with being in the slow descent group: younger patients (less than the median age of 65 years), p = 0.003, relative risk (RR) 2.256 (95% confidence interval (CI), 1.249-4.073) and prostates smaller than the median 41 cc, p = 0.034, RR 0.550 (95%CI, 0.320-0.944). All patients with a waist circumference of >100 cm were in the rapid descent group. Among the patients with a VF/SF >0.9, 83% were in the slow descent group. Conclusions: In this small pilot study, waist circumference and VF/SF were weakly correlated to pretreatment characteristics. There seems to be a tendency that an increase in visceral fat and waist circumference has an influence on the type of PSA response. Larger studies are needed to determine if anthropomorphic measures have a direct influence on post-brachytherapy PSA response.

Evaluating the Phoenix Definition of Biochemical Failure After 125I Prostate Brachytherapy: Can PSA Kinetics Distinguish PSA Failures From PSA Bounces?

To evaluate the prostate-specific antigen (PSA) kinetics of PSA failure (PSAf) and PSA bounce (PSAb) after permanent (125)I prostate brachytherapy (PB). The study included 1,006 consecutive low and "low tier" intermediate-risk patients treated with (125)I PB, with a potential minimum follow-up of 4 years. Patients who met the Phoenix definition of biochemical failure (nadir + 2 ng/mL(-1)) were identified. If the PSA subsequently fell to ≤0.5 ng/mL(-1)without intervention, this was considered a PSAb. All others were scored as true PSAf. Patient, tumor and dosimetric characteristics were compared between groups using the chi-square test and analysis of variance to evaluate factors associated with PSAf or PSAb. Median follow-up was 54 months. Of the 1,006 men, 57 patients triggered the Phoenix definition of PSA failure, 32 (56%) were true PSAf, and 25 PSAb (44%). The median time to trigger nadir + 2 was 20.6 months (range, 6-36) vs. 49 mo (range, 12-83) for PSAb vs. PSAf groups (p < 0.001). The PSAb patients were significantly younger (p < 0.0001), had shorter time to reach the nadir (median 6 vs. 11.5 months, p = 0.001) and had a shorter PSA doubling time (p = 0.05). Men younger than age 70 who trigger nadir +2 PSA failure within 38 months of implant have an 80% likelihood of having PSAb and 20% chance of PSAf. With adequate follow-up, 44% of PSA failures by the Phoenix definition in our cohort were found to be benign PSA bounces. Our study reinforces the need for adequate follow-up when reporting PB PSA outcomes, to ensure accurate estimates of treatment efficacy and to avoid unnecessary secondary interventions.

Cross-Border Banking and the International Transmission of Financial Distress During the Crisis of 2007-2008

We study the effect of financial distress in foreign parent banks on local SME financing in 14 central and eastern European countries during the early stages of the 2007-2008 financial crisis. We use survey data on applicant and non-applicant firms that enable us to disentangle effects driven by shocks to the banking system from recession-driven demand shocks that may vary across lenders. We find strong evidence that credit tightened in the relatively early stages of the crises caused by the following types of bank financial distress: 1) low equity ratio; 2) low Tier 1 capital ratio; and 3) losses on financial assets. We also find that foreign banks transmit to Main Street a larger portion of similar financial shocks than domestic banks. The observed decline in credit is greater among high-risk firms and firms with fewer tangible assets.

Discretionary Measurement of Financial Assets during the 2008 Financial Crisis

In the absence of quoted prices in active markets, the measurement of fair values is complex and difficult to verify. Prior literature finds that investors discount fair value estimates based on unobservable inputs (i.e., Level 3). However, these value relevance tests cannot discern whether the discount is attributable to managerial opportunism or illiquidity concerns. This paper examines whether banks use Level 3 fair value estimates to manage earnings during the 2008 Financial Crisis. Based on a sample of 329 U.S. banks, we find that banks with earnings management incentives (i.e., low earnings, negative change in earnings, small negative earnings, and low Tier 1 capital) recognize lower-than-necessary losses on Level 3 positions. Our inferences are robust to alternative specifications including the use of bank fixed effects, placebo tests with Level 3 gains or losses recognized in other comprehensive income (OCI), and benchmarking against discretionary loan loss provisions (LLP).

Tiered Categorization of a Diverse Panel of HIV-1 Env Pseudoviruses for Assessment of Neutralizing Antibodies

The restricted neutralization breadth of vaccine-elicited antibodies is a major limitation of current human immunodeficiency virus-1 (HIV-1) candidate vaccines. In order to permit the efficient identification of vaccines with enhanced capacity for eliciting cross-reactive neutralizing antibodies (NAbs) and to assess the overall breadth and potency of vaccine-elicited NAb reactivity, we assembled a panel of 109 molecularly cloned HIV-1 Env pseudoviruses representing a broad range of genetic and geographic diversity. Viral isolates from all major circulating genetic subtypes were included, as were viruses derived shortly after transmission and during the early and chronic stages of infection. We assembled a panel of genetically diverse HIV-1-positive (HIV-1(+)) plasma pools to assess the neutralization sensitivities of the entire virus panel. When the viruses were rank ordered according to the average sensitivity to neutralization by the HIV-1(+) plasmas, a continuum of average sensitivity was observed. Clustering analysis of the patterns of sensitivity defined four subgroups of viruses: those having very high (tier 1A), above-average (tier 1B), moderate (tier 2), or low (tier 3) sensitivity to antibody-mediated neutralization. We also investigated potential associations between characteristics of the viral isolates (clade, stage of infection, and source of virus) and sensitivity to NAb. In particular, higher levels of NAb activity were observed when the virus and plasma pool were matched in clade. These data provide the first systematic assessment of the overall neutralization sensitivities of a genetically and geographically diverse panel of circulating HIV-1 strains. These reference viruses can facilitate the systematic characterization of NAb responses elicited by candidate vaccine immunogens.

The use of Collembola avoidance tests to characterize sewage sludges as soil amendments

The ecotoxicological characterization of sewage sludge takes into account the additive, antagonistic and synergistic effects that occur as a result of multi-chemical interactions. Such an evaluation therefore is essential to complement the chemical analysis that, although required by law, is clearly insufficient. Using a tiered approach in the toxic evaluation of sewage sludge allows for characterization of toxicity in a timely manner. According to the literature, reproduction tests with Folsomia candida are suitable tools for the toxic assessment of organic sludges. Therefore, the inclusion of Collembola avoidance tests at a screening level (low tier), and acting as a trigger for longer-period tests (high tier; e.g. reproduction test), may provide a successful strategy, and may complement the currently proposed test battery. To evaluate the use of both avoidance and reproduction tests with collembolans in such a tiered approach, three sewage sludges (urban, olive and electroplating industries) were mixed in with a field-collected soil at different concentrations. Avoidance and reproduction tests were performed with the soil–sludge mixtures after 0, 4 and 12 weeks of incubation. The tests detected no toxicity in soil–sludge mixtures of urban and olive sludges at any incubation period. Mixtures with sludge from the electroplating industry induced toxicity only in the avoidance tests with freshly prepared and 4-week incubated samples. These results demonstrate the ability of Collembola avoidance tests to assess sewage sludge toxicity over time and its potential for hazardous sludge characterization at low tier levels.

Mobility management and signaling traffic analysis for multi-tier wireless mobile networks

A multi-tier wireless system integrates the high-tier wireless systems and the low-tier wireless systems into a single system to provide the advantages of both tiers. Such a system is expected to provide better service (more service availability and more cost effectiveness to the users) at the expense of the extra tier-switching management. Examples of multi-tier systems include the interconnection network of a satellite communication network and a terrestrial cellular network, the integration of low-power systems such as wireless personal area networks and cellular systems, and the integration of higher mobility of cellular systems with low-mobility wireless local area networks. In such a system, mobility management is critical, because only when the location of a mobile user is known or tracked can the service quality for the user be guaranteed. In this paper, we study a few mobility management schemes for multi-tier wireless mobile networks under more realistic assumptions. Performance evaluation in terms of registration signaling traffic is carried out, and easy-to-use analytical results are obtained. It is also clear that for service availability, the two-tier system is better than the single one-tier system; we therefore study the probability that a call is forced to terminate in the single low-tier system because the low tier becomes unavailable during the call (such a call can be continued in the two-tier system).

A Two-Tier Heterogeneous Mobile Ad Hoc Network Architecture and Its Load-Balance Routing Problem

The mobile ad hoc network (MANET) has attracted a lot of interest recently. However, most of the existing works have assumed a stand-alone MANET. In this paper, we propose a two-tier, heterogeneous MANET architecture which can support Internet access. The low tier of the network consists of a set of mobile hosts each equipped with a IEEE 802.11 wireless LAN card. In order to connect to the Internet and handle the network partitioning problem, we propose that the high tier is comprised of a subset of the mobile hosts, called gateways, which can access to cellular/infrastructure networks. The high tier is heterogeneous in the sense that the network interfaces in the gateway hosts could be IEEE 802.11 cards, PHS handsets, or GPRS handsets characterized by different bandwidths and latencies. Observing that the gateways could become the bottlenecks of the two-tier network, we propose a set of solutions, namely boundary-moving, host-partitioning, and probabilistic solutions, to solve the load-balance routing issue. Implementation issues/concerns of these schemes are discussed. Simulation results are presented to compare these load-balance routing schemes.

IT governance and management in large Australian organisations

This paper presents the result of a study on the governance and management of information technology (IT) in large Australian organisations. The study consisted of a questionnaire survey that was mailed to the most senior IT officer within the organisation. The respondents were categorised into three groups based on the intensity with which the company uses information, namely high tier, medium tier and low tier industries. The findings are compared between these three groups and show some interesting differences. The results are also compared with the findings from two other recent studies. Based on the results, the paper presents recommendations for companies in the high, medium and low tier industries.

A system dynamic model for the assessment of different exposure routes in aquatic ecosystems

With the exception of a limited number of highly persistent lipophilic pollutants, waterborne exposure is considered the most relevant exposure route for aquatic organisms, and even the only relevant exposure route in lower tier assessment, while the potential for bioaccumulation is only evaluated as secondary poisoning for birds and mammals. In addition, some evaluations consider that only the dissolved fraction is bioavailable for pelagic organisms. The lack of easy and cost-effective assessment methods is probably the main reason to disregard the contribution of other routes. This paper presents a system dynamics model that estimates the time-dependent accumulation of toxic chemicals through the food chain, and has also the potential to include the exposure from sediment. The generic ecosystem includes a primary producer and three levels of consumers, represented by unicellular algae, cladoceran invertebrates, cladoceran-eating fish and fish-eating fish, respectively. Nevertheless, the model, built using Microsoft Excel software, allows any number of levels and ecological-exposure relationships. The results obtained for four illustrative pollutants demonstrate that factors such as the binding to algae and other edible particles or food chain exposure for lipophilic non-persistent chemicals may constitute significant exposure routes. The current low tier European ecological risk assessment guidelines do not cover these aspects, and therefore may under estimate the real risk for both aquatic organisms and their predators. The model includes a simplified worst-case alternative that normally can be calculated using the existing information. Under a tiered approach, the simplified alternative is proposed to trigger the need of the toxicokinetics assays required to perform the complete time-dependent calculation.