bluuebunny/crossref_metadata_2025 huggingface dataset:
O encontro da política nacional da educação ambiental com a política nacional do idoso
Authors: Machado Rosangela Fátima de Oliveira , Garcia Velasco Fermin de La Caridad , Amim Valéria
Published: March 2008

Neste artigo discutimos a possível convergência entre a Política Nacional da Educação Ambiental (PNEA) e a Política Nacional do Idoso (PNI). Apresentamos um quadro comparativo de semelhanças e contradições na aplicação dessas políticas por parte da Administração Pública. A análise das políticas indica possibilidades de trabalhos comunitários e institucionais em que o idoso tenha papel de relevância na sociedade a partir de suas experiências passadas e presentes, para contribuir com a conscientização de outras gerações sobre questões ambientais. Neste sentido, a proposta é ter o idoso - partindo de sua experiência acumulada - como eixo de um trabalho ambiental, que possa oferecer às outras gerações um caminho para mudar os conceitos internalizados sobre o que é preservar o meio ambiente, constituindo-se em uma perspectiva interdisciplinar de caráter inclusivo. Trabalhar essas duas políticas públicas concomitantemente é tornar mais clara e rápida a execução de práticas primordiais para a melhora da qualidade de vida individual, da qualidade do ambiente onde vivem e da qualidade das relações interpessoais.
Um algoritmo branch-and-bound para o problema de programação de projetos com custo de disponibilidade de recursos e múltiplos modos
Authors: Yamashita Denise Sato , Morabito Reinaldo
Published: March 2008

Em um estudo anterior (YAMASHITA; MORABITO, 2007a), foi proposto um algoritmo exato para resolver o problema de programação de projetos com custo de disponibilidade de recursos, considerando múltiplos modos de execução para as atividades. O algoritmo é uma adaptação de outro algoritmo exato da literatura para o caso particular do problema em que só existe um modo de executar as atividades. No presente estudo, é proposto um novo algoritmo exato baseado no método branch-and-bound para tratar do problema com múltiplos modos de execução. Como o problema é NP-difícil, o algoritmo é viável computacionalmente apenas para resolver exemplares de tamanho moderado. Diversos testes computacionais utilizando o programa gerador Progen da literatura foram realizados para comparar o desempenho do algoritmo proposto com o algoritmo anterior e também com o aplicativo CPLEX. Os resultados obtidos mostram que a versão atual do algoritmo é competitiva com os outros métodos, e estimulam a pesquisa e o desenvolvimento de versões mais elaboradas deste algoritmo.
Accounting quality versus auditor choice under strong tax-GAAP conformity: the case of Brazil
Authors: Mello-E-Souza Carlos
Published: March 2008

Brazilian companies with a Big 4 auditor have better accounting quality than those with a local auditor, when accounting quality is measured either by compliance with GAAP or by conservatism. However, the cross-sectional pattern of discretionary accruals-often used to measure accounting quality in other countries-is unrelated to quality in Brazil. In fact, companies with Big 4 auditors tend to recognize income more aggressively than companies with a local auditor. This is the opposite of what happens in other countries and it is consistent with local auditors interpreting the tax code (rather than GAAP) more aggressively than Big 4 auditors, due to the strong linkage that exists between the Brazilian tax code and financial reporting standards.
Mutagenic hazards of complex polycyclic aromatic hydrocarbon mixtures in contaminated soil
Authors: Lemieux Christine L , Lambert Iain B , Lundstedt Staffan , Tysklind Mats , White Paul A
Published: March 2008

The objective of the present study was to evaluate hazard/risk assessment methods for complex environmental mixtures that involve a targeted, priority chemical approach based on the cumulative hazard/risk of known mixture components or analyses of sufficiently similar mixtures. Ten polycyclic aromatic hydrocarbon (PAH)–contaminated soils were separated into nonpolar and semipolar fractions, and both fractions elicited positive responses on the Salmonella reverse mutation assay. Targeted and nontargeted methods of hazard prediction routinely overestimated mutagenic activities for the nonpolar soil fractions, suggesting nonadditive interactions of PAHs in complex mixtures. This suggests that current risk assessment methods for complex mixtures may provide conservative estimates regarding soils contaminated with priority PAHs alone. Significant underestimations of total risk, however, will be obtained if the soils also contain unidentified PAHs as well as polycyclic aromatic compounds and related compounds that contribute to the total mutagenic activity. Furthermore, estimates of excess lifetime cancer risk associated with the nondietary ingestion of the PAH-contaminated soils studied here indicate that a traditional risk assessment model based on identified priority PAHs and an assumption of additivity generally underestimates the risk associated with the nonpolar soil fractions (in comparison to bioassay-derived risk estimates). Additional cancer risk may be associated with the more polar compounds that also are found at these contaminated sites and that rarely are included in the standard risk assessment methodology.
Detecting the transport of toxic pesticides from golf courses into watersheds in the precambrian shield region of ontario, canada
Authors: Metcalfe Tracy L , Dillon Peter J , Metcalfe Chris D
Published: March 2008

Golf courses impact the environment through alterations to habitat and through the release of nutrients and pesticides. The Precambrian Shield region of central Ontario, Canada, which is a major recreational area, is especially susceptible to the impacts of golf courses as a result of the geology and hydrology of the region. In a monitoring program at two golf courses in the Muskoka region conducted during the spring, summer, and fall of 2002, semipermeable membrane devices (SPMDs) were deployed into streams that drain the golf courses. The extracts from the SPMDs were tested for toxicity using bioassays with early life stages of an aquarium fish, the Japanese medaka (Oryzias latipes). Toxicity was assessed using a scoring system developed for the present study. The bioassays with medaka indicated that toxicity was highest in extracts from SPMDs deployed during the spring and the fall. The peaks in toxicity for the SPMDs deployed at the two golf courses corresponded with the presence in the SPMD extracts of pentachloronitrobenzene (PCNB) at concentrations up to 334 ng/SPMD. Quintozene is the turfgrass fungicide in which PCNB is the active ingredient. Pentachlorothioanisole, an anaerobic degradation product of PCNB, also was detected in the SPMDs deployed during the spring. Extracts prepared from SPMDs with high toxicity contained residues of a surfactant used in pesticide formulations, nonylphenol, at concentrations up to approximately 20 μg/SPMD. Overall, these data indicate that some pesticides applied to golf courses in the Precambrian Shield of central Ontario may have the potential to cause toxic impacts to aquatic organisms in adjacent watersheds.
Laboratory degradation studies of four endocrine disruptors in two environmental media
Authors: Sarmah Ajit K , Northcott Grant L
Published: March 2008

We investigated the degradation of 17β-estradiol (E2), 17α-ethinylestradiol (EE2), bisphenol-A (BPA), and 4-n-nonyl-phenol (4-n-NP) in river water–sediment and groundwater–aquifer material under aerobic and anaerobic conditions. The results showed rapid degradation of all four compounds in both media with >90% of the four compounds degraded within the first 2 to 4 d under both conditions. However, degradation rates were extremely slow for the remaining period. Model derived 50% dissipation time (DT50) values in river water–sediment slurries ranged from 0.24 to 1.5 d (E2), 0.29 to 1.1 d (EE2), 1.2 to 1.4 d (BPA), and 0.42 d (4-n-NP), while the 90% dissipation time (DT90) values for the four endocrine-disrupting chemicals (EDCs) ranged from 0.9 to 2.8 d under both conditions. A minor difference was observed in DT50 and DT90 values for the four EDCs in groundwater-aquifer material under aerobic conditions as compared with river water–sediment. Under anaerobic conditions, DT90 values ranged from >1,000 d (EE2) to >300 d (BPA), in groundwater–aquifer material. Degradation of the four compounds under anaerobic conditions was attributed to the sulfate-, nitrate-, and iron-reducing conditions within the tested media; however, it was postulated that overall degradation of the compounds was also influenced by abiotic factors, accounting for nearly 6 to 40% (river water-sediment) and 0 to 18% (groundwater–aquifer material) under the two conditions tested.
Heterocypris incongruens as a tool to estimate sewage sludge toxicity
Authors: Oleszczuk Patryk
Published: March 2008

The toxicity of 13 sewage sludges was evaluated in relation to the crustacean Heterocypris incongruens. The bioassay used was a commercial, direct contact test that allows evaluation of solid-phase toxicity. Evaluation of sewage sludges included physicochemical properties (pH, total organic C, total N, cation-exchange capacity, total exchangeable bases, available forms of p and K, and electrical conductivity), heavy metal content (cadmium, chromium, copper, lead, nickel, and zinc), and content of polycyclic aromatic hydrocarbons (16 from the U.S. Environmental Protection Agency list). The evaluated parameters were then compared with bioassay results (mortality and growth inhibition). Sewage sludges were characterized by optimal physicochemical properties; low K (<5.64 mg/kg) and total organic C (177–253 g/kg) levels were noted. Contaminant content (heavy metals and polycyclic aromatic hydrocarbons) clearly differed between individual sewage sludges. Polycyclic aromatic hydrocarbon contents ranged from 3.8 to 36.4 mg/kg. Total concentrations of heavy metals in all sewage sludges (with the exception of one sludge) were lower than the pollutant concentration limits for land application. Heterocypris incongruens mortality when sludge was applied at doses of 6, 12, or 24% ranged from 0 to 70%, from 4.7 to 72.1%, and from 0 to 100%, respectively. Average growth inhibition was 39.7 to 46.6% (depending on the sludge dose applied). Any stimulating influence of two sewage sludges on the test organism was recorded. The median lethal concentrations calculated for individual sewage sludges ranged from 88 to 956 g sewage sludge/kg.
Oxidative stress, defense response, and early biomarkers for lead-contaminated soil in Vicia faba seedlings
Authors: Wang Cheng-Run , Wang Xiao-Rong , Tian Yuan , Yu Hong-Xia , Gu Xue-Yuan , Du Wen-Chao , Zhou Hui
Published: March 2008

Chemical analyses and biological measurements were investigated in leaves of Vicia faba seedlings exposed to extraneous lead (Pb) at 0 to 2,000 mg/kg of soil for a month. The results showed that superoxide radical (O•−2) production, increased along with total Pb in leaves and available Pb in soil, resulted in enhancement of malondialdehyde and carbonyl groups. Antioxidant enzymes, including corresponding isoenzymes and heat shock protein 70 (hsp 70), were also enhanced to some extent. Significant changes were detected in the patterns and intensities of guaiacol peroxidase isoenzymes, while superoxide dismutase, catalase, and ascorbate peroxidase isoenzymes only changed intensities. Superoxide dismutase activities increased with the increase of extraneous Pb at 0 to 500 mg/kg of soil and tended to decline thereafter, which might be responsible for the decrease of hydrogen peroxide and accumulation of O•−2. Guaiacol peroxidase and ascorbate peroxidase enzymes were upregulated to become major scavengers of excess hydrogen peroxide on the condition of decreased catalase activities. Levels of hsp 70 were well correlated with Pb contents in leaves (r = 0.777), O•−2 accumulation (r = 0.985, p < 0.01), and carbonyl groups (r = 0.920, p < 0.01) under extraneous Pb at 0 to 250 mg/kg of soil, suggesting that hsp 70 induced by O•−2 was possibly involved in disposal of denatured proteins. The results showed that O•−2, hsp 70, and guaiacol peroxidase isoenzymes had the most sensitive responses in the seedlings and these parameters could be potential early biomarkers of soil Pb contamination.
Heating treatment schemes for enhancing chelant-assisted phytoextraction of heavy metals from contaminated soils
Authors: Chen Yahua , Wang Chunchun , Wang Guiping , Luo Chunling , Mao Ying , Shen Zhenguo , Li Xiangdong
Published: March 2008

Recent research has shown that chelant-assisted phytoextraction approaches often require a high dosage of chelant applied to soil. The present study focused on optimization of phytoremediation processes to increase the phytoextraction efficiency of metals at reduced chelant applications. Pot experiments were carried out to investigate the effects of increased soil temperature on shoot uptake of heavy metals by corn (Zea mays L.) and mung bean (Vigna radiat L. Wilczek) from heavy metal–contaminated soils. After the application of S,S-ethylenediaminedisuccinic acid or ethylenediaminetetra-acetic acid, soils were exposed to high temperatures (50 or 80°C) for 3 h, which significantly increased the concentration of heavy metals in shoots. The heating treatment 2 d after the chelant addition resulted in higher concentrations of metals compared with those treatments 2 d before or simultaneously with the chelant application. Irrigation with 100°C water 2 d after the chelant addition, or irrigation with 100°C chelant solutions directly, also resulted in significantly higher phytoextraction of metals in the two crops compared with 25°C chelant solutions. In addition, a novel application method to increase soil temperature using underground polyvinyl chloride tubes would increase the chelant-assisted extraction efficiency of Cu approximately 10- to 14-fold in corn and fivefold in mung bean compared with those nonheating treatments. In a field experiment, increasing soil temperature 2 d after chelant addition also increased the shoot Cu uptake approximately fivefold compared with those nonheating treatments. This new technique may represent a potential, engineering-oriented approach for phytoremediation of metal-polluted soils.
Evaluation of sample preparation methods for nuclear magnetic resonance metabolic profiling studies withEisenia fetida
Authors: Brown Sarah A. E , Simpson André J , Simpson Myrna J
Published: March 2008

The earthworm Eisenia fetida is frequently used in ecotoxicological studies; however, it has not yet been investigated using proton nuclear magnetic resonance (1H NMR) metabolic profiling methods. The present study investigates the impact of depuration time, sample homogenization, and different extraction solvents on the quality and reproducibility of the 1H NMR spectra of E. fetida with the goal of determining whether this species is suitable for future metabonomic studies. A depuration time of 96 h, followed by intact lyophilization before homogenization and extraction into a deuterium oxide (D2O)-based phosphate buffer, was found to produce extracts with excellent 1H NMR reproducibility. The D2O buffer extracted the largest quantity of the widest variety of earthworm metabolites, which is consistent with the results from other studies using different earthworm species. Nuclear magnetic resonance assignments of the major metabolites in the D2O-based buffer also were performed and found to be similar to those for other earthworm species, such as Eisenia veneta, but also to have characteristic attributes in E. fetida. The major metabolites identified include amino acids (alanine, arginine, glutamic acid, glutamine, glycine, leucine, lysine, phenylalanine, serine, tyrosine, and valine), two sugars (glucose and maltose), the sugar alcohol mannitol, and the polyalcohol inositol. Two other earthworm species (Lumbricus rubellus and Lumbricus terrestris) also were examined using protocols developed for E. fetida, and of the three species, the 1H NMR spectra of E. fetida had the least variation, indicating this species is well-suited for future metabolomic-based ecotoxicity studies.
Dietary uptake models used for modeling the bioaccumulation of organic contaminants in fish
Authors: Barber M. Craig
Published: March 2008

Numerous models have been developed to predict the bioaccumulation of organic chemicals in fish. Although chemical dietary uptake can be modeled using assimilation efficiencies, bioaccumulation models fall into two distinct groups. The first group implicitly assumes that assimilation efficiencies describe the net chemical exchanges between fish and their food. These models describe chemical elimination as a lumped process that is independent of the fish's egestion rate or as a process that does not require an explicit fecal excretion term. The second group, however, explicitly assumes that assimilation efficiencies describe only actual chemical uptake and formulates chemical fecal and gill excretion as distinct, thermodynamically driven processes. After reviewing the derivations and assumptions of the algorithms that have been used to describe chemical dietary uptake of fish, their application, as implemented in 16 published bioaccumulation models, is analyzed for largemouth bass (Micropterus salmoides), walleye (Sander vitreus = Stizostedion vitreum), and rainbow trout (Oncorhynchus mykiss) that bioaccumulate an unspecified, poorly metabolized, hydrophobic chemical possessing a log KOW of 6.5 (i.e., a chemical similar to a pentachlorobiphenyl).
First Application of New Expandable Liner Hanger Technology in Deepwater HP/HT Well of Egypt
Authors: Moore Melvin , Lopez Jesse , Chacon Edgar , Waheed Arshad , Nida Ron
Published: March 2008

This paper discusses the application of a new expandable liner hanger system in a deepwater, high-pressure, high-temperature (HP/HT) well in the Mediterranean Sea, Egypt. At the time of its application in early April 2007, it was the first expandable liner hanger set in Egypt and the industry's first, deepest set depth (4870 m) for the 7 5/8–in. liner hanger size.

A majority of the liners run in this area for this operator can be classified as drilling liners that allow the well to be "cased off" at key points in the drilling sequence so that drilling can progress safely to its target depth. This case history is about setting a liner across a weak (lost circulation) zone and a high-pressure kick (saltwater) zone drilled in the same hole section. The liner hanger operation was deemed critical especially after having had an issue in the last hole section in setting a conventional 9 7/8–in. liner hanger packer resulting in 2.1 days of NPT (nonproductive time). It was important to get proper isolation of both the formations and the liner lap and the placement of the liner in the desired position to avoid having issues drilling ahead.

The expandable liner hanger (ELH) offers a significant departure in design from a conventional system. The mechanics of the ELH system eliminates the potential of a premature set of the hanger. Moreover, it eliminates the normal operating procedures of testing conventional liner tops and "dressing" cement left on top of the liner—operations that require a substantial amount of time and money to accomplish before drilling ahead can resume.

This paper will discuss the expandable liner system in detail with an insight into its design, operating procedures, its simplicity, and the benefits it provides even in difficult well conditions such as this case history.
One Company's First Exploration UBD Well for Characterizing Low Permeability Reservoirs
Authors: Woodrow C. K. , Elliott D. , Pickles R. , Cox D. B.
Published: March 2008

This paper describes the use of an under balanced drilling (UBD) system in a remote desert exploration well to directly evaluate the hydrocarbon reservoir inflow potential. The integrated sub-surface and well design team, planning, activity execution and results are discussed, with an assessment of the added value realized. The lessons learnt will be used to optimize the subsequent exploration and appraisal drilling activities, and in the longer term, optimization of subsequent field development activities.

The vision is effectively to inflow test all available hydrocarbon reservoirs while drilling, thereby generating a pseudo reservoir inflow profile as a function of depth without the uncertainty of drilling induced formation damage. To achieve this objective, the available under balance drilling operating parameters and drilling fluids, were proactively controlled. This allowed the rig crew to manage the inflow while drilling, and near well bore skin damage, reducing the uncertainty to optimize the reservoir information acquired. The activity was executed in Q3 2007.

Inflow testing in a known ‘non damaged state’ while drilling exploration and appraisal wells in desert areas remote from hydrocarbon processing and export infrastructure helps to reduce overall project risk. In low permeability reservoirs, over balance drilling induced near wellbore reservoir inflow impairment, has historically delivered inconclusive inflow data, resulting in higher project uncertainty and higher costs. UBD reservoir characterization information may be used to reduce subsequent well flow testing activities, which in turn, lowers project costs, speeds up the field appraisal process and reduces waste.
Simplified Country Risk Assessments for Global Petroleum Investments
Authors: Rajan Surya , Vikas Shree
Published: March 2008

As Rate of Reserve Replacement continues to be challenged, International Oil Companies (IOCs) face competition from other IOCs as well as from entrepreneurial national oil companies (NOCs) aggressively looking to develop assets domestically and overseas. A disproportionately large fraction of reserves are controlled by a few NOCs, and downstream resources are similarly pursued by NOCs and IOCs alike. Evaluation of potential countries or regions targeted for reserves replacement objectives must be made based on assessment of key risk factors for mid to long timeframe.

Country Risk Assessments for new country or region entry decisions serve as a crucial decision point in determining viability of project or project portfolio from a location perspective, but such assessments typically tend to be time consuming, complex, somewhat subjective, and often do not provide a basis for any objective comparison between candidate countries or regions.

Using a matrix of weighted risk factors this model presents a simplified approach for objectively assessing a potential country or region under consideration, and provides a basis for apples-to-apples comparison between shortlisted countries or regions. This approach is applicable to IOCs, NOCs, or Service Companies alike. Based on a relevance-weighted approach this model can assist in quick screening before further due diligence is embarked on. This not only accelerates decision-making for such investment considerations, but also provides input for later detailed project risk management.
A hybrid neural networks and numerical models approach for predicting groundwater abstraction impacts
Authors: Birkinshaw S. J. , Parkin G. , Rao Z.
Published: March 2008

A rapid assessment method for evaluating the impacts of groundwater abstraction on river flow depletion has been developed and tested. A hybrid approach was taken, in which a neural network model was used to mimic the results from numerical simulations of interactions between groundwater and rivers using the SHETRAN integrated catchment modelling system. The use of a numerical model ensures self-consistent relationships between input and output data which have a physical basis and are smooth and free of noise. The model simulations required large number of input parameters and several types of time series and spatial output data representing river flow depletions and groundwater drawdown. An orthogonal array technique was used to select parameter values from the multi-dimensional parameter space, providing an efficient design for the neural network training as the datasets are reasonably independent. The efficiency of the neural network model was also improved by a data reduction approach involving fitting curves to the outputs from the numerical model without significant loss of information. It was found that the use of these techniques were essential to develop a feasible method of providing rapid access to the results of detailed process-based simulations using neural networks.
Single-reservoir operating rules for a year using multiobjective genetic algorithm
Authors: Kim Taesoon , Heo Jun-Haeng , Bae Deg-Hyo , Kim Jin-Hoon
Published: March 2008

A monthly operating rule for single-reservoir operation is developed in this study. Synthetic inflow data over 100 years are generated by using a time series model, AR(1), and piecewise-linear operating rules consisting of 4 and 5 linear lines are found using the implicit stochastic optimization method. In order to consider multiobjective functions in reservoir system operation, a multiobjective genetic algorithm (NSGA-II) is adopted to obtain the optimization results. The search space of NSGA-II is carefully refined using frequency analysis of historical data, and the relationship between inflow and constraints is also investigated. It is determined that 4 and 5 segments are the optimal number of segments for the piecewise-linear operating rule, and the effect of random number seeding on NSGA-II is evaluated. Six years of historical inflow data are used for the simulation model and the results show that the developed operating rule would handle various inflow series. As a result, probabilistic reservoir storage forecasts can be provided to a system operator so as to enable the operator to evaluate the current status of a reservoir quantitatively.
Role of macroporosity in runoff generation on a sloping subsurface drained clay field — a case study with MACRO model
Authors: Hintikka Salka , Paasonen-Kivekäs Maija , Koivusalo Harri , Nuutinen Visa , Alakukku Laura
Published: March 2008

Macroporosity and its effect on runoff processes were studied on a sloping subdrained clay field (very fine Aeric Cryaquept) in Southern Finland. An extensive field campaign was carried out to measure the spatial variability of soil macroporosity and hydraulic properties. According to the field data, macropore conductivity decreased with depth and soil properties showed differences between the upper and lower parts of the field. A one-dimensional model (MACRO) was applied to quantify the effect of these differences on the hydrological response of the upper and lower field sites. Based on the measurements, five separate parameterizations characterizing the differences in soil structure between the measurement sites were formulated. The change in soil structure had a great effect on the relative proportions of simulated drain flow and surface runoff but influenced only slightly the total amount of runoff. Evapotranspiration and percolation were similar in all cases. Examining model simulations, measured runoff components and groundwater table suggested that a two- or three-dimensional modeling approach is necessary, when prediction of proportional fractions of drain flow and surface runoff, and simulation of groundwater level in a sloping field are of interest.
On-farm options for managing stream salinity in irrigation areas: an example from the Murray Darling Basin, Australia
Authors: Khan Shahbaz , Nadeem Asghar Muhammad , Mushtaq Shahbaz , Ahmad Aftab
Published: March 2008

Increasing salt concentration in tributaries from catchments and rising water tables are the prime contributor to environmental degradation of rivers, creeks, streams or other water bodies. This is especially true during periods of mid- and low stream flows in arid and semi-arid regions around the globe. Catchment scale studies suggest that management of stream salinity requires greater land use change than is economically viable. Therefore, rather than focusing on the opportunity cost of catchment scale interventions, exploring interventions that are potentially viable at farm scale could be an appropriate strategy for stream salinity management. This paper presents an analysis of alternative on-farm strategies, such as evaporation ponds and serial biological concentration of salts, aimed at developing an economically self-sustainable stream salinity management system for the Box Creek stormwater escape channel located in the Murray–Darling Basin (MDB), Australia. It is concluded that irrigation areas, with careful management of flows in tributary streams, may be able to play a role in safeguarding the Murray River against further salinisation from irrigation and dryland areas. The outcomes of this paper will be helpful, but not limited to, the MDB in addressing environmental, economic and social issues associated with management of salt concentration in tributaries.
The Erosion of Employment-Based Insurance: More Working Families Left Uninsured
Authors: Gould Elise
Published: March 2008

The number of Americans without health insurance rose from 38.4 million in 2000 to 47.0 million in 2006, primarily due to the precipitous decline in employer-provided health coverage for workers and their families. Nearly 3.9 million fewer Americans under 65 had employer-provided coverage in 2006 than in 2000. The downward trend in the rate of employer-provided insurance continued for the sixth year in a row, falling from 68.3 to 62.9 percent. Individuals among the bottom 20 percent of household income were the least likely to have employer coverage. Jobholders experienced a significant decline in health insurance coverage, from 74.8 percent of workers in 2000 to 70.8 percent in 2006. No category of workers was insulated from loss of coverage. Children experienced declines in employer-provided health insurance coverage (through their parents) in each of the past five years, the rate falling from 65.9 percent of children in 2000 to 59.7 percent in 2006. Public health insurance (Medicaid and the State Children's Health Insurance Program) is no longer offsetting these losses. The decline in employer-provided coverage was felt throughout the country. Between the 2000–2001 and 2005–2006 periods, 38 states experienced significant losses in employment-based coverage for the under-65 population. No state experienced a significant increase in the coverage rate.
Globalization of the Pharmaceutical Industry and the Growing Dependency of Developing Countries: The Case of Turkey
Authors: Semin Semih , Güldal Dilek
Published: March 2008

In developing countries, the effect of globalization on the pharmaceutical sector has resulted in a decrease in exportation and domestic production, accompanied by an increase in importation of pharmaceuticals and a rise in prices and expenditures. As an example of a developing country, Turkey has been facing the long-standing and increasing pressure of global regulations placed on its pharmaceutical sector. This has led to an increasing dependency on multinational companies and a gradual deterioration of an already weakened domestic pharmaceutical sector. This case study of Turkey offers points to consider in the world of increasing globalization, as it offers lessons on ways of examining the effects of globalization on the pharmaceutical industry of developing countries.
Functional traits and phylogeny: What is the main ecological process determining species assemblage in roadside plant communities?
Authors: Valladares F. , Tena D. , Matesanz S. , Bochet E. , Balaguer L. , Costa‐Tenorio M. , Tormo J. , García‐Fayos P.
Published: March 2008

Question:

What is the main ecological process determining species assemblage in roadside herbaceous plant communities?

Location:

Roadside slopes (roadcuts and embankments) in the south (Málaga, mesic Mediterranean) and east (Valencia, dry and continental) of the Iberian Peninsula.

Methods:

We identified 417 plant species, from which we selected the 331 most abundant (within the 70th abundance percentile) at each site. We compiled information on 28 functional traits and on the biogeographic range of each of these 331 species. We quantified the phylogenetic signal of each trait for the species of each community and determined the number of functional convergences or divergences over the phylogenetic tree for each of the four situations (roadcuts and embankments in the two sites).

Results:

There was a significant phylogenetic signal in many traits, being positive in Valencia embankments and negative in Valencia roadcuts with almost no signal in any type of slope in Malaga. Each trait was significantly correlated with 20% ‐ 35% of all other traits but correlation coefficients were low. No significant phylogenetic signal was found for the species'distribution range in any of the four communities studied, which might be the consequence of the complex mixture of biogeographic origins of the species found in these communities.

Conclusion:

The lack of a phylogenetic signal in most traits in Malága, a climatically favourable locality, suggests that competitive exclusion was the main process involved in the assemblage of these communities. The significant and either positive or negative phylogenetic signal (in embankments and roadcuts respectively), the latter coupled with a significant number of functionally convergent nodes in the phylogenetic tree, suggests that environmental filtering is the most likely process involved in the harsh locality of Valencia.
Attenuation to Control Gene Expression
Authors: Babitzke Paul , Gollnick Paul
Published: March 2008

Bacteria use a variety of strategies to regulate transcription elongation in response to changes in their environment. Several of these regulatory events are classified as transcription attenuation mechanisms, which involve regulated transcription termination to control expression of downstream genes. In most cases, two alternative RNA secondary structures, an antiterminator and an intrinsic terminator, share nucleotides in common such that their formation is mutually exclusive. Thus, the level of expression of the downstream genes depends on the frequency that the antiterminator forms in the nascent transcript. Transcription attenuation mechanisms in general are separated into two categories. The first category involves situations in which the action of a regulatory molecule promotes transcription termination, with the default situation being transcription readthrough. The second category involves situations in which the action of the regulatory molecule promotes transcription readthrough (antitermination), with the default situation being transcription termination. Transcription attenuation controls the expression of several amino acid biosynthetic and catabolic operons. These mechanisms are often controlled by the efficiency of leader peptide synthesis in Gram‐negative bacteria, whereas Gram‐positive organisms often use RNA binding proteins or tRNA molecules to determine whether the RNA will fold into the antiterminator or terminator structures. Several examples of transcription attenuation also exist in which an antisense RNA is responsible for controlling plasmid copy number. In addition, small metabolites participate in transcription attenuation mechanisms of a wide variety of bacterial genes by binding directly to the nascent transcript.
Lysosomal Disorders
Authors: Brooks Doug A. , Fuller Maria
Published: March 2008

Lysosomal storage disorders are a group of over 50 different genetic diseases that result from lysosomal dysfunction. This disruption of lysosomal function can involve either a specific lysosomal hydrolase deficiency, a defect in lysosomal protein processing, or impaired lysosomal biogenesis. To appreciate the pathogenesis of lysosomal disorders fully, it is important to understand the dynamics of endosome–lysosome organelles, their capacity for the uptake and degradation of complex macromolecules, and how lysosomal biogenesis and hydrolysis are altered by substrate storage. The focus of this article will be on recognized lysosomal disorders and what is known about the composition and the function of endosome–lysosome organelles in these diseases. The lysosomal network will be discussed with a view to correlating the main site of endosome–lysosome degradation and the site of substrate accumulation in lysosomal disorders. A major unanswered question for lysosomal storage disorders is how an enzyme deficiency and the resulting storage of undegraded macromolecules impact on cells to cause organ dysfunction and disease.
Membrane Fluidity
Authors: Dzikovski Boris , Freed Jack H.
Published: March 2008

In the popular fluid mosaic model for biomembranes, membrane proteins and other membrane‐embedded molecules are in a two‐dimensional fluid formed by the phospholipids. Such a fluid state allows free motion of constituents within the membrane bilayer and is extremely important for membrane function. The term “membrane fluidity” is a general concept, which refers to the ease of motion for molecules in the highly anisotropic membrane environment. We give a brief description of physical parameters associated with membrane fluidity, such as rotational and translational diffusion rates, order parameters etc., and review physical methods used for their determination. We also show limitations of the fluid mosaic model and discuss recent developments in membrane science that pertain to fluidity, such as evidence for compartmentalization of the biomembrane by the cell cytoskeleton.
Mitogen‐activated Protein Kinases (
MAPKs
):
ERKs
,
JNKs
, and
p
38
s
Authors: Chen Wei , Juang Yu‐Chi , Cobb Melanie
Published: March 2008

Mitogen‐activated protein kinases (MAPKs) are significant mediators in signal transduction pathways from the membrane to intracellular compartments including the nucleus. They regulate the functions of many gene products and therefore affect cell growth, differentiation, and death. Three main MAPK subfamilies have been identified and are studied widely. All function in cascades that include at least three tiers of protein kinases. Selective kinase inhibitors have been developed; they are powerful tools to study the physiologic functions of MAPKs and, in some cases, are promising and effective drugs. In this article, the regulation of the three main MAPK pathways is sketched, and the status of MAPK inhibitors and their inhibiting mechanisms are highlighted.
Mathematical Modelling of Biological Signaling Networks
Authors: Haugh Jason M.
Published: March 2008

Intracellular signaling networks, which are composed of interconnected biochemical pathways, regulate and actuate responses such as cell‐cycle progression and cell migration, survival, and differentiation. Although our knowledge of the intricate biochemical mechanisms at the level of individual proteins and molecular interactions is ever expanding, those details leave us with an even murkier view of how the complex network operates as a whole. True understanding requires knowing not only what happens at the molecular level but also how these mechanisms influence the precise magnitude, timing, and spatial localization of signal transduction processes. Hence, mathematical modeling and analysis has emerged in recent years as a legitimate approach for interpreting experimental results and generating novel hypotheses for additional study and model refinement. Once conducted in isolation and scorned by most biologists, quantitative modeling has moved into the mainstream as a powerful tool for the analysis of cell signaling. In this article, the biological, chemical, and physical underpinnings of this approach are presented, as are its current applications and future challenges.
Terpenoids in Plant Signaling: Chemical Ecology
Authors: Kappers Iris F. , Dicke Marcel , Bouwmeester Harro J.
Published: March 2008

Terpenoids constitute the largest class of secondary metabolites in the plant kingdom. Because of their immense structural diversity and the resulting diversity in physiochemical properties, these molecules are particularly important for plant communication with other organisms. In this article, we will describe the ecological significance of terpenoids for plants, how terpenoid formation is regulated, and the tools we have to improve our understanding of the role of terpenoids in plant ecology and to create crop plants with improved resistance.
Triplex Formation by Pyrene‐Labelled Probes for Nucleic Acid Detection in Fluorescence Assays
Authors: Van Daele Ineke , Bomholt Niels , Filichev Vyacheslav V. , Van Calenbergh Serge , Pedersen Erik B.
Published: March 2008

Triplex‐forming homopyrimidine oligonucleotides containing insertions of a 2′–5′ uridine linkage featuring a pyrene moiety at the 3′‐position exhibit strong fluorescence enhancement upon binding to double‐stranded DNA through Hoogsteen base pairing. It is shown that perfect matching of the new modification to the base pair in the duplex is a prerequisite for strong fluorescence, thus offering the potential to detect single mutations in purine stretches of duplex DNA. The increase in the fluorescence signal was dependent on the thermal stability of the parallel triplex, so a reduction in the pH from 6.0 to 5.0 resulted in an increase in thermal stability from 25.0 to 55.0 °C and in an increase in the fluorescence quantum yield (ΦF) from 0.061 to 0.179, while the probe alone was fluorescently silent (ΦF=0.001–0.004). To achieve higher triplex stability, five nucleobases in a 14‐mer sequence were substituted with α‐L‐LNA monomers, which provided a triplex with a Tm of 49.5 °C and a ΦF of 0.158 at pH 6.0. Under similar conditions, a Watson–Crick‐type duplex formed with the latter probe showed lower fluorescence intensity (ΦF=0.081) than for the triplex.
Identification, Synthesis, and Enzymology of Non‐natural Glucosinolate Chemopreventive Candidates
Authors: Mays Jared R. , Weller Roska Rachel L. , Sarfaraz Sami , Mukhtar Hasan , Rajski Scott R.
Published: March 2008

Isothiocyanates (ITCs) are one of the many classes of breakdown products of glucosinolates found in crucifers such as broccoli and are thought to be partially responsible for the reduced risk of degenerative diseases associated with the consumption of vegetables. The production of ITCs such as L‐sulforaphane is dependent on the hydrolytic bioactivities of myrosinase, localized both within vegetable tissues and within flora of the human GI tract, and is associated with important cancer chemopreventive activities. We hypothesized that novel isothiocyanates with enhanced chemopreventive properties relative to L‐sulforaphane could be identified and that their glucosinolate precursors could be synthesized. From a library of 30 synthetic ITCs, we identified several with bioactivities equal or superior to those of L‐sulforaphane. The corresponding non‐natural glucosinolate precursors to these novel ITCs were constructed and found to be substrates for myrosinase. By utilizing a novel RP‐HPLC assay to monitor myrosinase‐dependent hydrolysis reactions, 2,2‐diphenylethyl glucosinolate and (biphenyl‐2‐yl)methyl glucosinolate were shown to exhibit 26.5 and 2.8 %, respectively, of the relative activity of sinigrin and produced their corresponding ITCs in varying yields. These data support the notion that non‐natural glucosinolates can act as prodrugs for novel ITCs, with a mechanism of action reliant on their hydrolytic cleavage by myrosinase. Such non‐natural glucosinolates may serve as very economical chemopreventive agents for individuals at risk for cancers of and around the GI tract.
Complexation and Fluorescence of Tricyclic Basic Dyes Encapsulated in Cucurbiturils
Authors: Montes‐Navajas Pedro , Corma Avelino , Garcia Hermenegildo
Published: March 2008

Tricyclic basic dyes (proflavine, acridine orange, pyronine, pyronine Y, oxonine, thionine and methylene blue) often form one‐to‐one or two‐to‐one complexes with CB[7] and CB[8], respectively. In the case of pyronine Y, the complexes with CB[7] and CB[8] have a one‐to‐one and three‐to‐one stoichiometry, respectively. The binding constants for CB[7] complexes range from 3.07×106 to 1.70×107 m−1. In the case of CB[8], the association constant varies between 3.24×1013 and 2.50×1016 m−2. Overall, these binding constants are four orders of magnitude higher than those reported for the same dyes in β and γ‐cyclodextrins. Formation of the host–guest complexes leads to an increase in the fluorescence quantum yields in the case of CB[7], while the dimeric or trimeric dye encapsulated in CB[8] are remarkably less fluorescent than the same dye in diluted solutions.
Synthesis, Characterization, Spectroscopic and Photophysical Properties of New [Cu(NCS){(L‐N)2 or (L′‐NN)}(PPh3)] Complexes (L‐N, L′‐NN = Aromatic Nitrogen Base)
Authors: Pettinari Claudio , di Nicola Corrado , Marchetti Fabio , Pettinari Riccardo , Skelton Brian W. , Somers Neil , White Allan H. , Robinson Ward T. , Chierotti Michele R. , Gobetto Roberto , Nervi Carlo
Published: March 2008

The syntheses, spectroscopic characterization (IR, 1H and 31P NMR, ESI‐MS) and conductivity studies of the mixed N,P‐donor complexes of copper(I) thiocyanate: [Cu(NCS)(py)2(PPh3)], (2), [Cu(NCS)(Mepy)(PPh3)]2, (3), [Cu(NCS)(phen)(PPh3)], (4), [Cu(NCS)(bpy)(PPh3)], (5), [Cu(NCS)(bpy)(PPh2py)], (6), [Cu(NCS)(py)(PPh2py)], (7), (py = pyridine; Mepy = 2‐methylpyridine; phen = 1,10‐phenanthroline, bpy = 2,2′‐bipyridyl), together with single‐crystal X‐ray structural characterizations of 2, 3, 4 (new polymorph), 5 and 6 are reported, which provides an opportunity to study the effect of the introduction of a pair of nitrogen donors, both unidentate and chelate, on the bonding parameters of the Cu/NCS/P system. Cu–P and Cu–N2(ar) are found to be similar [2.1974(5) and 2.091(2), 2.070(1) Å for py2 adduct 2, cf. 2.1748(9)–2.200(1) and 2.071(2)–2.106(4) Å for the counterpart values for bidentate adducts 4–6]. However, Cu–N(CS) and Cu–N–C are 2.013(2) Å and 157.4(2)° for py2 adduct 2 and 1.946(2)–1.981(8) Å and 166.7(2)–176.58(2)° for bidentate counterparts 4–6. The change is attributed primarily to the closure in the N–Cu–N angle [99.58(8)° for py2 2; 77.7(6)–80.5(3)° for N∧N‐bidentate donors 4–6]. In consequence of the increased steric profile of the Mepy ligand, we find the stoichiometry diminished to 1:1:1, which resulted in theformation of [(Ph3P)MepyCu(SCNNCS)Cu(Mepy)(PPh3)] dimers.TDDFT/CPCM calculations were used to clarify the type of transitions involved in the UV/Vis absorption spectra, and the corresponding experimental photoemission data wereacquired. The 31P CPMAS spectra of the copper derivatives exhibit distorted quartets that afford values for 1JCu,P. Furthermore, the quadrupole‐induced distortion factors were calculated, and in the cases of 2, 4 and 5, the quadrupole coupling constants were obtained, on the basis of the X‐ray structures.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Self‐Assembly of p‐Sulfonatocalix[4]arene and a Ag–hmt Coordination Polymer into a Porous Structure
Authors: Zheng Guo‐li , Zhang Hong‐Jie , Song Shu‐Yan , Li Yin‐Yan , Guo Hua‐Dong
Published: March 2008

A novel porous material constructed from p‐sulfonatocalix[4]arene molecules and a AgI coordination polymer has been structurally characterized. The porous supramolecular complex features a bilayer arrangement of p‐sulfonatocalix[4]arene molecules linked by a AgI–hmt (hmt: hexamethylenetetramine) coordination polymer through metal–ligand bonding, hydrogen bonding and host–guest interactions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)