bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of very small wastewater treatment plants with pronounced load variations
Authors: Kegebein J. , Hoffmann E. , Hahn H.H.
Published: April 2007

The operation of very small biological wastewater systems is strongly influenced by the patterns of wastewater generation. The absence of people in the connected building(s) during holidays or off-season leads to a system underload, other circumstances however may lead to an overload. Experiments have been carried out to display the effects of no-feed conditions on activated sludge biomass and its microbial activity during a 24 hour period after re-feeding. The decrease of the biomass during idle periods can be modelled by a first order equation. The initial specific oxygen uptake rate (OUR) of the remaining biomass decreased with the duration of the preceding no-feed sequence. Four different laboratory-scale treatment plants were operated to demonstrate the system performance when re-started after a break period of 24 and 52 days respectively. The effluent concentration after a break of 52 days had not been sufficient as compared to the discharge requirements given by German laws. In addition a full scale trickling filter was monitored, while the connected building accommodated a maximum of 40 guests interrupted by times with no guest at all. Conclusions are drawn from the experimental results and from literature, giving some hints on how to manage the impacts of varying loads at very small wastewater treatment plants.
Anaerobic membrane bioreactor for treatment of synthetic municipal wastewater at ambient temperature
Authors: Ho J.H. , Khanal S.K. , Sung S.
Published: April 2007

Non-woven fabric filter and poly-tetrafluoroethylene (PTFE) composite membrane were investigated to determine their applicability to treat low strength wastewater in an anaerobic membrane bioreactor (AMBR). Sludge cake resistance of the membrane was quantified using pure water flux of anaerobic sludge cake accumulated on the glass fiber filter of similar pore size. It is hypothesized that the formation of thin cake layer on the porous medium, e.g. non-woven and PTFE acts as a dynamic membrane. Thus, the capture of thin sludge cake inside the non-woven fabric matrix and accumulation on the PTFE membrane surface forms a membrane system equivalent to a commercial membrane system. The permeate quality was found to improve as the cake became more dense with filtration time. The PTFE composite membrane coated with thin PTFE film on the non-woven fabric filter enhanced the filtration performance by improving flux and minimizing the propensity of bio-fouling. The membrane flux was restored by back-flushing with permeate. The AMBR coupled with PTFE laminated membrane was operated continuously during the experiment at a cross flow velocity (CFV) of 0.1–0.2 m/sec and a transmembrane pressure (TMP) of 0.5–3 psi. Although about a month of acclimation was required to reach steady state, the effluent chemical oxygen demand (COD), volatile fatty acids (VFAs) as acetic acid, and suspended solids (SS) concentrations were below 30, 20 and 10 mg/L, respectively, during 90 days of operation with intermittent back washing. The lower operation TMP and CFV were subjected to less shear stress on the microbial community during continuous AMBR operation. In addition, thin sludge film accumulated on the membrane surface also acted as a biofilm bioreactor to remove additional COD in this study
Development of an empirical mathematical model for describing and optimizing the hygiene potential of a thermophilic anaerobic bioreactor treating faeces
Authors: Lübken M. , Wichern M. , Bischof F. , Prechtl S. , Horn H.
Published: April 2007

Poor sanitation and insufficient disposal of sewage and faeces are primarily responsible for water associated health problems in developing countries. Domestic sewage and faeces are prevalently discharged into surface waters which are used by the inhabitants as a source for drinking water. This paper presents a decentralized anaerobic process technique for handling of such domestic organic waste. Such an efficient and compact system for treating faeces and food waste may be of great benefit for developing countries. Besides a stable biogas production for energy generation, the reduction of bacterial pathogens is of particular importance. In our research we investigated the removal capacity of the reactor concerning pathogens, which has been operated under thermophilic conditions. Faecal coliforms and intestinal enterococci have been detected as indicator organisms for bacterial pathogens. By the multiple regression analysis technique an empirical mathematical model has been developed. The model shows a high correlation between removal efficiency and both, hydraulic retention time (HRT) and temperature. By this model an optimized HRT for defined bacterial pathogens effluent standards can be easily calculated. Thus, hygiene potential can be evaluated along with economic aspects. In this paper not only results for describing the hygiene potential of a thermophilic anaerobic bioreactor are presented, but also an exemplary method to draw the right conclusions out of biological tests with the aid of mathematical tools.
Modification of submerged membrane bioreactors (MBRs) by inserting baffles: pilot scale study
Authors: Kimura K. , Enomoto M. , Watanabe Y.
Published: April 2007

Submerged membrane bioreactors (MBRs) have been gaining in popularity in various types of wastewater treatment. One drawback of submerged MBRs is difficulty in removing nitrogen as they are accompanied with intensive aeration inside the reactor and therefore principally operated under aerobic conditions. In order to address this problem, a simple modification for submerged MBRs, insertion of baffles to create alternative aerobic/anoxic conditions, was proposed. In this study, the performance of the proposed baffled membrane bioreactor (BMBR) was investigated based on a pilot-scale experiment using a real municipal wastewater. With appropriate operating conditions, the BMBR could remove more than 70% of total nitrogen contained in the feed water without any external carbon source. The BMBR demonstrated a good treatment performance in terms of TOC and phosphorus removal as well. Increase of trans-membrane pressure difference was subtle, which might be attributed to the alternative creation of aerobic/anoxic conditions.
Vertical flow constructed wetland for textile effluent treatment
Authors: Davies L.C. , Vacas A. , Novais J.M. , Freire F.G. , Martins-Dias S.
Published: April 2007

A pulse feed vertical flow constructed wetland (VFCW) proved to be efficient in the treatment of a textile effluent being able to buffer, dilute and treat an Acid Orange (AO7) accidental discharge. The influence of the flooding level (FL) and pulse feed (PF) duration on the removal efficiencies of a VFCW was examined. Average AO7 removal efficiencies of 70% were achieved for an AO7 Inlet concentration of 700 mg l−1 applied during 15 min cycle−1 (every three hours) at a hydraulic load of 13 l m−2 cycle−1 and an FL of 21%. The VFCW was modelled by analogy with a combination of ideal reactors. The simplest combination that best reproduced the experimental results was an association of 2 reactors in series plus 1 reactor accounting the dead volumes. The model parameters helped to understand the hydrological and kinetic processes occurring in VFCW. Through the model simulation it was shown that 3 VFCW in series were enough to efficiently treat an organic mass load of 76 gAO7 m−2 day−1 in 9 hours and fulfil the discharge legislation. In this work it was possible to establish that the overall degradation kinetics was of first order.
Integrated constructed wetland systems: design, operation, and performance of low-cost decentralized wastewater treatment systems
Authors: Behrends L.L. , Bailey E. , Jansen P. , Houke L. , Smith S.
Published: April 2007

Several different types of constructed wetland systems are being used as decentralized treatment systems including surface-flow, subsurface-flow, vertical-flow, and hybrid systems. Archetypical wetland systems have design strengths and weaknesses, and therefore it should be possible to design combined (integrated) systems to optimize a number of important treatment processes. This study provides comparative efficacy data for two integrated wetland treatment systems (IWTS) designed to enhance treatment of medium strength wastewater generated from a pilot-scale intensive fish farm. Results from the twenty eight months study included consistently high removal of COD (84%+) and ammonia nitrogen (93%) in both systems. Initially, phosphorus removal was also high (>90%) in both systems, but removal efficacy declined significantly over time. Nitrate removal was significantly better in the system that provided sequential aerobic and anoxic environments. Short hydraulic retention times coupled with sustained removal of COD and ammonia indicate that the ReCip components could be a least-cost wastewater treatment technology in the decentralized market sector.
Experimental study on nitrogen components during composting process of feces
Authors: Hotta S. , Noguchi T. , Funamizu N.
Published: April 2007

We measured nitrogen components during composting process of feces in a batch test in which sawdust was used as a matrix. Further decomposition rates of fecal nitrogen and carbon were obtained in the batch tests of different feces loading. In composting material that was a mixture of sawdust and fresh feces, fecal organic matter decomposed to CO2 and fecal nitrogen mineralized to ammonia during the composting process. The biological response of organic matter and nitrogen in the composting material was evaluated by oxygen consumption (OUR) and ammonia production that was a sum of volatilized ammonia gas and ammonia remaining in the composting material. Since composting material contains two different sources of organic matter from feces and sawdust, the OUR by using the sawdust matrix only was evaluated in preliminary tests. The fecal contribution to the OUR in the composting material was therefore calculated by subtraction of the result in the preliminary tests from the one in the composting material. The ammonia production from the fecal nitrogen was obtained by the same procedure. The decomposition rates of input organic matter in feces were approximately 83 and 70% respectively, whereas ammonia production rates were approximately 73 and 58% of input fecal nitrogen. There was an interesting time lag of the peak time between volatilisation rates of ammonia and CO2 during the composting process while fecal carbon and nitrogen simultaneously decomposed to ammonia and CO2 in the composting material.
Wastewater treatment with activated pre-clarifier and planted soil filters
Authors: Lindenblatt C. , Wichern M. , Horn H.
Published: April 2007

With a series of buffer tank, activated pre-clarifier (SBR) and planted soil filters, it is possible to get a stable degradation and good effluent values in the case of unsteady inflow and changing concentrations. In the process presented here the activated pre-clarifier is working as a denitrification tank and the soil filter as a nitrification reactor. An automatic control manages the storm-water runoff, the water-recirculation returns the nitrate and provides a minimal feed. Experiences with this plant from 1999 to 2005 are given in this paper, research has been done in the project “Planted soil filters as a Biotechnological Process”, founded by the German Federal Environment Foundation (DBU). A full scale pilot plant was built to treat wastewater from composting sides, with a 42 m3 SBR and a bed area of 2 × 550 m2 of the planted soil filters. Now, after six years of operation, the results are still satisfactory. Besides this pilot plant, landfill leakage and municipal wastewater have been treated in a technical scale plant with the same process in an 80 L SBR and 0.75 m2 vertical flow soil filter with good results.
Wastewater infiltration percolation for water reuse and receiving body protection: thirteen years' experience in Spain
Authors: Brissaud F. , Salgot M. , Folch M. , Auset M. , Huertas E. , Torrens A.
Published: April 2007

Infiltration percolation (IP) is an extensive technology to treat primary or secondary effluents of small and middle size communities before reuse or disposal to sensitive receiving bodies. Thirteen years of implementation of IP in Spain has highlighted the necessity to abide by defined design and construction rules and operation conditions in order to achieve consistently the treatment objectives and guarantee a long lasting treatment capacity. From this experience, high care should be taken of (i) the characteristics of the sand constituting the filter, (ii) the drainage conditions, (iii) the influent spreading over the infiltration surface and (iv) the risks related to recurrent overloading. Simple monitoring measures are suggested in order to improve the reliability of IP plants.
Biological aerated filtration of municipal wastewater using a low-cost filtration media
Authors: González-Martínez S. , Millán T. , González-Barceló O.
Published: April 2007

The main objective of this research was to demonstrate that selected natural lava stones can be successfully used for low-cost aerobic biofiltration of municipal wastewater. To demonstrate the procedure a pilot filter was built using 6 mm lava stones as support material. The filter depth was 3.0 m. Provided with sampling ports at different depths analysis of the wastewater could be made for COD, TSS, ammonia and nitrates nitrogen, pH, temperature and Kjeldahl nitrogen. Backwashing was performed every 72 hours. Total and dissolved COD and TSS behaved similarly with the organic load: The highest removal rates were observed with the lowest organic load of 0.8 kgCOD/m3 d. These removal rates decreased to a minimum value at organic loading rates of 1.5 kgCOD/m3 d and then remained without noticeable changes to the highest value of 3.5 kgCOD/m3 d. The highest total and dissolved COD removal values were 81 and 84%, respectively. For TSS the best removal value was 95%. Up to 75% ammonia removal was achieved at the lowest organic load of 0.8 kgCOD/m3 d. Ammonia removal decreased to 36% with a higher organic load of 1.6 kgCOD/m3 d. The Mean Cellular Retention (MCRT) time varied from 1 to 6 days with an average of 3.2 days. This fact proves that the MCRT depends on the backwashing frequency more than of any other factor involved. The bed volume decreased in about 5% after 300 days of operation. Microscopic observations showed that the small stones were rounder after 300 days and that the volume losses were caused when the edges of the stones were cut by the abrasion caused by backwashing.
Health Care Reform and the Paradox of Efficiency: “Writing in” Culture
Authors: Anderson Joan M. , Tang Sannie , Blue Connie
Published: April 2007

Widespread global migration is occurring at the same time that health care delivery systems in Western nations are undergoing major restructuring. The call for health care to be more efficient, economical, and responsive to diverse cultural populations has come from several sectors, including governments and researchers. This has led to policies to address perceived deficiencies in health care services. The authors draw on their research at health care institutions in a western Canadian city to probe, first, how the concept of culture is interpreted within organizations; and second, how culture is “written into health systems” as they undergo restructuring. Meanings and interpretations of culture are not transparent; moreover, “writing in” culture is not simply a matter of health care providers learning about their clients' “belief systems” and being sensitive to these beliefs. Belief systems and people's experiences of the care they receive are negotiated within highly complex “organizational cultures,” located in broader macroeconomic and political structures, and discourses that shape how health care systems are organized. The authors consider whether current discourses on cost containment are in competition with providing equitable health care services to diverse client populations.
Falling into the Medical Poverty Trap in Sri Lanka: What Can be Done?
Authors: Perera Myrtle , Gunatilleke Godfrey , Bird Philippa
Published: April 2007

Sri Lanka's public health care system is free at the point of use and maintains a focus on equity. However, noncommunicable diseases, such as diabetes, are rapidly increasing in prevalence and posing new challenges to the system and to patients and households. In-depth interviews and focus group discussions were conducted in four districts of Sri Lanka to investigate the care-seeking experiences of diabetes patients from households at different income levels. Although health care is free, other direct and indirect costs served as deterrents to care seeking before and after diagnosis, and placed a high burden on households. The need for frequent visits to clinics with appropriate facilities for diagnosis and management of diabetes, often far from rural communities, posed high costs, in particular due to income foregone. Households employed coping strategies, but the need for frequent clinic visits posed repeated costs, which made it difficult for households to recover their economic status. Many patients, especially those from low-income, rural households, could not maintain the management regimen, and their condition deteriorated. There is a need for specialist facilities for the diagnosis and management of diabetes at locations closer to rural areas.
Patterns of Agricultural Pesticide Use in Relation to Socioeconomic Characteristics of the Population in the Rural U.S. South
Authors: griffith matt , Tajik Mansoureh , Wing Steve
Published: April 2007

Residents of rural, agricultural areas where pesticides are used experience increased potential for pesticide exposure. In the rural U.S. South, where communities are predominantly of color, increased agricultural chemical use can constitute environmental injustice. Lacking data on the amounts of pesticide applied, the authors used county-level expenditure on agricultural chemicals as a proxy for pesticide use to explore spatial patterns of pesticide expenditure in relation to racial and economic composition in 953 rural counties in 12 southern states. Approximately eight times more money was spent on pesticides in counties with populations having more than 40 percent persons of color than in counties with less than 6 percent. Approximately four times more money was spent in counties with more than 22 percent of their population living in poverty than in counties with less than 12 percent. After adjusting for agricultural land area and land use, the authors found counties with more than 40 percent persons of color and more than 22 percent poverty spent about $1.3 million more on pesticides in 2002 than did counties with less than 6 percent persons of color and 12 percent poverty. This pattern of pesticide expenditures may produce racial and economic inequities in environmental exposures to pesticides, having implications for environmental justice and public health.
A molecular dynamics study on iridium
Authors: Ferah Gülen , Colakoglu Kemal , Ciftci Yasemin , Ozgen Soner , Kazanc Sefa
Published: April 2007

In this study, molecular dynamics simulations are performed by using a modified form of Morse potential function in the framework of the Embedded Atom Method (EAM). Temperature-and pressure-dependent behaviours of bulk modulus, second-order elastic constants (SOEC), and the linear-thermal expansion coefficient is calculated and compared with the available experimental data. The melting temperature is estimated from 3 different plots. The obtained results are in agreement with the available experimental findings for iridium.
How exact are simplified scalar approaches to optical fields in oxide-confined stripe-geometry diode lasers?
Authors: Czyszanowski T. , Nakwaski W.
Published: April 2007

Optical model, scalar or vectorial one, describing behaviour of an optical field within a diode-laser cavity, is one of the most important parts of modelling of a diode-laser operation. As compared to more accurate vectorial optical approaches, scalar ones are known to be less exact but simultaneously they need much less computation time. Besides, they have been sometimes found to be surprisingly exact even beyond their confirmed range of validity. Therefore, in this paper, real validity limits of their application have been determined by comparing their simplified results with more exact results obtained with the aid of vectorial models. The analysis comprises a comparison of an application of the most popular scalar approach to optical properties of diode lasers, i.e., the effective index method, and the vectorial method of lines for the standard 1.3-µm GaAs-based stripe-geometry diode laser. The scalar model has been found to be quite exact in the case of a determination of the effective refractive index, i.e., the wavelength of emitted radiation, whereas its exactness in the lasing threshold analysis is much worse, especially in the case of higher-order modes. Our analysis is concluded with a determination of the regions where both models give satisfactorily close results.
Directly modulated lasers in negative dispersion fiber links
Authors: Krehlik P.
Published: April 2007

In the paper the impact of frequency chirp of directly modulated lasers is considered in context of high-speed data transmission over negative dispersion fiber. Chirp/dispersion induced signal distortions are described, and detailed investigations of their influence on 10 Gb/s transmission system performance are presented. The desired laser chirp characteristics and optimal driving conditions are determined. It is also demonstrated that directly modulated laser with low chirp offers similar or even better dispersion tolerance than unchirped (externally modulated) source. Experimental verification of described investigations is presented at the end.
Polycrystalline lead selenide: the resurgence of an old infrared detector
Authors: Vergara G. , Montojo M. , Torquemada M. , Rodrigo M. , Sánchez F. , Gómez L. , Almazán R. , Verdú M. , Rodríguez P. , Villamayor V. , Álvarez M. , Diezhandino J. , Plaza J. , Catalán I.
Published: April 2007

The existing technology for uncooled MWIR photon detectors based on polycrystalline lead salts is stigmatized for being a 50-year-old technology. It has been traditionally relegated to single-element detectors and relatively small linear arrays due to the limitations imposed by its standard manufacture process based on a chemical bath deposition technique (CBD) developed more than 40 years ago. Recently, an innovative method for processing detectors, based on a vapour phase deposition (VPD) technique, has allowed manufacturing the first 2D array of polycrystalline PbSe with good electro optical characteristics. The new method of processing PbSe is an all silicon technology and it is compatible with standard CMOS circuitry. In addition to its affordability, VPD PbSe constitutes a perfect candidate to fill the existing gap in the photonic and uncooled IR imaging detectors sensitive to the MWIR photons. The perspectives opened are numerous and very important, converting the old PbSe detector in a serious alternative to others uncooled technologies in the low cost IR detection market. The number of potential applications is huge, some of them with high commercial impact such as personal IR imagers, enhanced vision systems for automotive applications and other not less important in the security/defence domain such as sensors for active protection systems (APS) or low cost seekers.

Despite the fact, unanimously accepted, that uncooled will dominate the majority of the future IR detection applications, today, thermal detectors are the unique plausible alternative. There is plenty of room for photonic uncooled and complementary alternatives are needed. This work allocates polycrystalline PbSe in the current panorama of the uncooled IR detectors, underlining its potentiality in two areas of interest, i.e., very low cost imaging IR detectors and MWIR fast uncooled detectors for security and defence applications. The new method of processing again converts PbSe into an emerging technology.
Sectioned offenders presenting with enduring mental illness: a study exploring behaviors indicative of bullying
Authors: Ireland Jane L. , Rowley John
Published: April 2007

Logit and logistic regression analyses were employed to explore the nature, extent and predictors of behaviors indicative of “being bullied” and of “bullying others” in a sample of 125 adult male offender‐patients sectioned for enduring mental illness and detained within a high‐secure psychiatric hospital. The study addresses the lack of research into this specialized population to date, with a subsidiary aim of comparing the results directly with a previous study conducted with a population of adult male personality‐disordered offender‐patients (n = 53). Participants were required to complete a self‐report behavioral checklist (Direct and Indirect Patient behavior Checklist‐Hospital version Revised). The prediction that indirect (subtle) aggression would be reported more frequently than direct aggression was supported in relation to perpetration estimates, with evidence such aggression was also more prevalent among personality‐disordered than mentally ill offender‐patients. As predicted verbal aggression was the most commonly reported direct behavior. Although it was predicted that those perpetrating aggression would present with increased experience with secure settings this was only supported with regard to bully‐victims. Contrary to the prediction made, those victimized did not present with less experience of secure settings. Consistent with the hypothesis, bully/victims were predicted by increased negative behavior toward staff and hospital rules. The results are discussed in relation to the environment in which the aggression is taking place with the implications for practice and future research outlined. Aggr. Behav. 33:377–388, 2007. © 2007 Wiley‐Liss, Inc.
Reactive, but not proactive aggression predicts victimization among boys
Authors: Salmivalli Christina , Helteenvuori Tiia
Published: April 2007

Prospective links among reactive aggression, proactive aggression, and victimization by peers were investigated in a longitudinal sample of 238 preadolescents (aged 10–13 years, 52% girls). No predictive links were found between victimization and either type of aggression among girls. Among boys, reactive aggression predicted higher future levels of victimization but was not itself affected by prior victimization. In contrast, boys' proactive aggression predicted lower levels of future victimization and was itself reduced by their prior victimization. Finally, reactive aggression predicted later proactive aggression for both boys and girls. These results are explained in terms of the different reactions that others have to proactive and reactive aggression, the different functions they serve, and to the different types of aggression that are common for boys and girls. Aggr. Behav. 33:1–9, 2007. © 2007 Wiley‐Liss, Inc.
Monoamine oxidase A gene polymorphism predicts adolescent outcome of attention‐deficit/hyperactivity disorder
Authors: Li Jun , Kang Chuanyuan , Zhang Haobo , Wang Yufeng , Zhou Rulun , Wang Bing , Guan Lili , Yang Li , Faraone Stephen V.
Published: April 2007

ADHD is generally deemed to be a highly heritable disorder with mean heritability of 0.75. The enzyme monoamine oxidase (MAO), which has both A and B types, has long been considered a candidate pathological substrate for ADHD, and more recently, the genes for both MAO enzymes have been examined as mediators of the illness. Previous studies indicated that 30–50% of children with ADHD will experience symptoms that persist into adolescence and will have more significant impairment in social and neuropsychological functioning compared to those whose symptoms have remitted. Genes may also influence these characteristics of the disorder, and in this context MAO genes may also be candidates for moderating the presentation of ADHD. The current study examined the association between adolescent outcome of ADHD and MAO gene polymorphisms, including the 941T > G polymorphism in exon 8 (rs1799835) and 1460C > T polymorphism in exon 14 (rs1137070) of the MAOA gene, and the A > G polymorphism in intron13 (rs1799836), C > T polymorphism in the 3'UTR (rs1040399), and 2327T > C polymorphism in exon15 of the MAOB gene. Significant associations were observed between the MAOA gene polymorphisms and ADHD remission. Due to the small sample size and the possibility of phenotypic and etiologic heterogeneity of ADHD outcomes across ethnic or geographic groups, these results must be replicated before they can be generalized to other populations. © 2007 Wiley‐Liss, Inc.
Nuclear receptor NR4A2 IVS6 +18insG and brain derived neurotrophic factor (BDNF) V66M polymorphisms and risk of Taiwanese parkinson's disease
Authors: Chen Chiung‐Mei , Chen I‐Cheng , Chang Kuo‐Hsuan , Chen Yi‐Chun , Lyu Rong‐Kuo , Liu Yen‐Tzu , Hu Fen‐Ju , Chao Chih‐Ying , Lee‐Chen Guey‐Jen , Wu Yih‐Ru
Published: April 2007

Both of environmental and genetic factors confer vulnerability to Parkinson's disease (PD). NR4A2 (Nurr1), a member of the steroid/thyroid hormone nuclear receptor superfamily, is essential for the neurogenesis and differentiation of dopaminergic neurons in the midbrain. Brain derived neurotrophic factor (BDNF) deficiency may play a role in the pathogenesis of PD, as the surviving dopaminergic nigrostriatal neurons have reduced levels of BDNF. This study examines whether BDNF V66M (c.196 G → A) or NR4A2 IVS6 +18insG polymorphism is associated with the risk of Taiwanese PD and the age of onset using a case‐control study. The genotype or allele frequency distribution of both BDNF V66M and NR4A2 IVS6 +18insG polymorphisms was not significantly different between the cases and the controls. Neither BDNF nor NR4A2 polymorphism influences PD onset age. Notably, after stratification by sex, female individuals carrying the NR4A2 2G/2G genotype demonstrated a trend toward significant decrease in risk of developing PD (OR = 0.49, 95% CI = 0.25–0.96, P = 0.039). These results suggest that the NR4A2 IVS6 +18insG polymorphism may play a minor role in PD susceptibility among Taiwanese women. © 2007 Wiley‐Liss, Inc.
A genome‐wide linkage analysis for the personality trait neuroticism in the Irish affected sib‐pair study of alcohol dependence
Authors: Kuo Po‐Hsiu , Neale Michael C. , Riley Brien P. , Patterson Diana G. , Walsh Dermot , Prescott Carol A. , Kendler Kenneth S.
Published: April 2007

Neuroticism is a personality trait which reflects individual differences in emotional stability and vulnerability to stress and anxiety. Consistent evidence shows substantial genetic influences on variation in this trait. The present study seeks to identify regions containing susceptibility loci for neuroticism using a selected sib‐pair sample from Ireland. Using Merlin regress, we conducted a 4 cM whole‐genome linkage analysis on 714 sib‐pairs. Evidence for linkage to neuroticism was found on chromosomes 11p, 12q, and 15q. The highest linkage peak was on 12q at marker D12S1638 with a Lod score of 2.13 (−log p = 2.76, empirical P‐value <0.001). Our data also support gender specific loci for neuroticism, with male specific linkage regions on chromosomes 1, 4, 11, 12, 15, 16, and 22, and female specific linkage regions on chromosomes 2, 4, 9, 12, 13, and 18. Some genome regions reported in the present study replicate findings from previous linkage studies of neuroticism. These results, together with prior studies, indicate several potential regions for quantitative trait loci for neuroticism that warrant further study. © 2007 Wiley‐Liss, Inc.
CGG repeat length correlates with age of onset of motor signs of the fragile X‐associated tremor/ataxia syndrome (FXTAS)
Authors: Tassone Flora , Adams John , Berry‐Kravis Elizabeth M. , Cohen Susannah S. , Brusco Alfredo , Leehey Maureen A. , Li Lexin , Hagerman Randi J. , Hagerman Paul J.
Published: April 2007

Fragile X‐associated tremor/ataxia syndrome (FXTAS) is a late‐onset neurological disorder among carriers of premutation CGG‐repeat expansions within the FMR1 gene. Principal features of FXTAS include progressive action tremor and gait ataxia, with associated features of parkinsonism, peripheral neuropathy, dysautonomia, and cognitive decline. Although both clinical and neuropathologic features of FXTAS are known to be highly associated with CGG repeat length, the relationship between repeat length and age‐of‐onset is not known. To address this issue, the ages of onset of action tremor and gait ataxia were documented by history for 93 male carriers. For this cohort, the mean ages of onset were 62.6 ± 8.1 years (range, 39–78 years) for tremor, and 63.6 ± 7.3 years (range, 47–78 years) for ataxia; the mean CGG repeat number was 88.5 ± 14 (range, 60–133). Analysis of the relationship between clinical onset and molecular measures revealed significant correlations between CGG repeat number and onset of both tremor (P = 0.001) and ataxia (P = 0.002), as well as overall onset (P < 0.0001). Our findings indicate that the CGG repeat number is a potential predictor of the age of onset of core motor features of FXTAS. © 2007 Wiley‐Liss, Inc.
Identification of two risk haplotypes for schizophrenia and bipolar disorder in the synaptic vesicle monoamine transporter gene (SVMT)
Authors: Gutiérrez Blanca , Rosa Araceli , Papiol Sergi , Arrufat Francisco J. , Catalán Rosa , Salgado Purificación , Peralta Víctor , Cuesta Manuel J. , Fañanás Lourdes
Published: April 2007

The synaptic vesicular monoamine transporter (SVMT) plays a key role in monoaminergic neurotransmission determining the size of neurotransmitter vesicular pools available for exocytotic release. Recently, several lines of evidence have suggested that altered functions of SVMT may be involved in the pathogenesis of certain neuropsychiatric diseases, including psychotic and mood disorders. In the present study, we tested the potential involvement of SVMT gene variants in the etiology of schizophrenia and bipolar disorder. Five different SNPs (T440G, C1368T, T2666C, A2683C, and A745G) were included in the analysis covering a region of about 35 kb along the SVMT gene. Analyses were performed in a case‐control sample consisting of 88 bipolar patients, 107 subjects with schizophrenia, and 164 controls. Two risk haplotypes for both schizophrenia and bipolar disorder in SVMT gene were identified. Particularly, 2666T‐2683A‐745G (TAG) and 2666C‐2683C‐745A (CCA) combinations were significantly more frequent in both bipolar and schizophrenic patients than in controls. UNPHASED package estimated haplotype effects for all patients yielded relative risks of 4.1 (95%CI: 1.83–9.21) for TAG combination and 2.336 (95%CI: 1.28–4.26) for CCA haplotype. Conversely, 2666T‐2683C‐745A (TCA) and 2666C‐2683A‐745G (CAG) haplotypes seemed to protect against these mental disorders, since the estimated frequency in control chromosomes was 12% whilst such haplotypes were not observed in any bipolar or schizophrenic subject (P < 0.0000). Our results strongly suggest that SVMT gene or certain regions of it may constitute a genetic substrate of susceptibility for both schizophrenia and bipolar disorder. © 2007 Wiley‐Liss, Inc.
Liquid‐crystalline epoxy resins
Authors: Galina H. , Mossety‐Leszczak B.
Published: April 2007

A new liquid‐crystalline epoxy monomer (LCEM) containing central triaromatic mesogen and aliphatic spacers consisting of eight methylene units terminated with epoxy groups was synthesized and characterized by means of IR and NMR spectrometry, differential scanning calorimetry (DSC), polarized optical microscopy, and wide‐angle X‐ray scattering. The cure reaction of LCEM with primary aromatic diamines in a stoichiometric ratio and with a tertiary amine catalyst of polymerization and the properties of the cured products were investigated with a DSC technique. The effects of the curing conditions (polyaddition vs anionic polymerization) and the structures of the amines on the formation of liquid‐crystalline networks were studied. The monomer cured with selected amines yielded an anisotropic network. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 224–228, 2007
Effect of hydrophobic modification on the rheological properties of poly(N‐vinyl pyrrolidone‐co‐dimethylaminopropylmethacrylamide)
Authors: Jachowicz J. , McMullen R. , Wu C. , Senak L. , Koelmel D.
Published: April 2007

The viscoelastic properties of poly(N‐vinyl pyrrolidone‐co‐dimethylaminopropylmethacrylamide) (copolymer I) and its hydrophobically modified analogue, poly(N‐vinyl pyrrolidone–dimethylaminopropylmethacrylamide–dimethylaminopropylmethacrylamide⊕–C12H25Cl⊖) (copolymer II), were compared in the concentration range from 1 to 20% with dynamic and Brookfield rheometers. In addition, gel permeation chromatography/multi‐angle laser light scattering light scattering data were obtained to characterize the molecular weights and radii of gyration for the polymer samples. In general, the hydrophobically modified polymer copolymer II was characterized by a chain configuration that was more compact and a viscosity that was an order of magnitude lower than that of its unmodified counterpart, copolymer I (both polymers were characterized by similar molecular weights), in dilute (1% w/w) and semiconcentrated solutions (<5% w/w). The difference in the chain configurations resulted in significant differences in the measured viscosities of the polymer solutions as a function of polymer concentration and in the presence of added electrolyte. On the basis of dynamic rheological measurements for more concen‐trated solutions in the range of 5–10% for copolymer I and 5–20% for copolymer II, the viscous modulus predominated (loss modulus > storage modulus), with crossover points occurring at 10% (w/w) and 10 Hz for copolymer I and 20% (w/w) and 20 Hz for copolymer II. The mixtures of copolymer II with anionic surfactants, such as sodium dodecyl sulfate and polyoxyethylene (2) dodecyl ether sulfate (sodium laureth‐2‐sulfate), showed strong interactions by exhibiting viscosity maxima and flocculation points corresponding to the surfactant/polymer alkyl group and surfactant/polymer charge concentration ratios in the range of 1–2. Copolymer II showed network formation by significant viscosity buildup in combination with two nonionic surfactants, which included C14–15 Pareth‐7 and C12–13 Pareth‐3. On the basis of viscosity measurements, copolymer I was found not to interact with anionic and nonionic surfactants. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 190–200, 2007
Synthesis of a linear polyethylene macromonomer and preparation of polystyrene‐graft‐polyethylene copolymers via grafting‐through atom transfer radical polymerization
Authors: Kaneyoshi Hiromu , Matyjaszewski Krzysztof
Published: April 2007

A vinyl‐terminated linear polyethylene (number‐average molecular weight = 1800, weight‐average molecular weight/number‐average molecular weight = 1.7, functionality = 92%) prepared by ethylene coordination polymerization was transformed into a monohydroxy‐terminated linear polyethylene by hydroalumination of the vinyl group with diisobutylaluminum hydride and subsequent oxidation and hydrolysis. This monohydroxy‐terminated linear polyethylene was quantitatively converted into a linear polyethylene macromonomer with a terminal α‐methacrylate group through esterification followed by dehydrobromination. A grafting‐through atom transfer radical polymerization of the α‐methacrylate‐terminated polyethylene and styrene was performed to yield a well‐defined polystyrene‐graft‐polyethylene copolymer. The number‐average molecular weight of the graft copolymers, measured by gel permeation chromatography, was lower than the predetermined number‐average molecular weight, presumably because of the intramolecular aggregation of polyethylene side chains. The α‐methacrylate‐terminated polyethylene content and number‐average molecular weight of polystyrene‐graft‐polyethylene were determined by 1H‐NMR. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 3–13, 2007
Addition of H3PO4 to diglycidyl ethers of bisphenol A: Kinetics and product structure
Authors: Penczek Stanislaw , Kaluzynski Krzysztof , Pretula Julia
Published: April 2007

The preparation of the addition products of H3PO4 to bisphenol A based epoxy resins is described. These products are considered modifiers of the epoxy resins and for the further formation of useful networks (coatings and related products). Depending on the ratio of H3PO4 to epoxy groups and other reaction variables, a family of oligomers with acidic end groups has been formed. The major reaction is the addition of H3PO4 to epoxy groups. Among the side reactions, the acid‐catalyzed addition of the >CHOH (and/or CH2OH) groups to epoxy groups dominates. The OH groups, if not present in the starting resins, are emerging from the POH to oxirane ring addition. The matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry analysis of the starting epoxy resins has revealed their structural diversity. In the kinetic measurements and determination of the ester composition, diglycidyl ether of bisphenol A (BADE) as a model compound has been mostly applied. The kinetics of the H3PO4–BADE reaction is described, and the structures of the final products are analyzed with 31P{1H}‐NMR, which gives (at pH ∼ 12) quantitatively the proportions of the monoesters, diesters, and triesters as well as the unreacted H3PO4. The conditions have been found leading exclusively to the monoester, and this indicates that an increase in the reaction temperature enhances the selectivity of the reaction; that is, it depresses the proportion of the acid‐catalyzed OH and epoxy group reaction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 246–254, 2007
Biodegradable blends of poly(L‐lactide) and starch
Authors: Kozlowski M. , Masirek R. , Piorkowska E. , Gazicki‐Lipman M.
Published: April 2007

Blends of poly(L‐lactide) (PLA), containing from 5, 15, or 25 wt % potato starch, unmodified or hydrophobized in methane plasma, were prepared and studied. To enhance the drawability of the blends, the plasticization of PLA with 10 wt % poly (ethylene glycol) (PEG) was also employed. The thermal and mechanical properties of the blends with amorphous and crystalline matrices were investigated. The hydrophobization of starch did not improve the ultimate properties of the blends, which were generally worse than those of neat PLA, because of the separation of the starch grains from the polymer matrix during tensile drawing. The separation also occurred in blends with a PEG‐plasticized matrix containing 15 wt % modified starch, which fractured earlier than PLA plasticized with PEG. Nevertheless, the elongation at break of the plasticized blends reached 1.3, which was considerably more than that of blends with corresponding starch contents without a plasticizer (ca. 0.05). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 269–277, 2007
Microtacticity changes during transesterification
Authors: Platé Nikolay A. , Litmanovich Arkady D. , Kudryavtsev Yaroslav V. , Demidenok Konstantin V.
Published: April 2007

The effect of a direct interchain exchange reaction (transesterification) on the microtacticity of polymer chains is studied with theory and a Monte Carlo simulation. Kinetic equations describing the evolution of the distribution over the type and length of the dyad sequences in the course of transesterification are derived. From this detailed consideration, the dependence of the average lengths of the isotactic and syndiotactic sequences on time is calculated for a melt of an initially isotactic homopolymer. It is shown that the microtacticity change proceeds at a rate similar to that of copolymer randomization during transesterification in polymer blends and much more slowly than the relaxation of the molecular mass distribution. The reacting chains for a long time consist of isotactic sequences of decreasing length and mostly isolated syndiotactic dyads. Possible effects of varying the ratio of the rate constants of the elementary reactions between dyads of different types are investigated. The agreement between the calculations and results of the Monte Carlo simulation is satisfactory. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 60–66, 2007
Diet supplement based on radiation‐modified chitosan and radiation‐synthesized polyvinylpyrrolidone microgels: Influence on the liver weight in rats fed a fat‐ and cholesterol‐rich diet
Authors: Czechowska‐Biskup Renata , Ulański Piotr , Olejnik Alicja K. , Nowicka Grażyna , Panczenko‐Kresowska Bogumiła , Rosiak Janusz M.
Published: April 2007

A polymer‐based preparation (a chitosan–microgel preparation called CHM), intended for use as a diet supplement reducing fat and cholesterol absorption from the digestive tract, was obtained by the combination of chitosan of a reduced molecular weight with a polyvinylpyrrolidone microgel in a 1 : 1 (w/w) ratio. Both components were obtained with ionizing radiation (controlled degradation of chitosan in the solid state and crosslinking polymerization of neat vinylpyrrolidone). The chitosan component was shown in previous in vitro studies to exhibit a high fat‐binding capacity, whereas the microgels, able to swell to about 40 times their original volume, were intended to serve as stomach‐filling agents. The influence of the CHM preparation on the body mass, the weight of the liver and other principal organs, and the serum levels of triglycerides and cholesterol was examined in rats fed a fat‐ and cholesterol‐rich diet (FChD). It was found that the preparation administered as a diet additive at 4% CHM (2% chitosan) in rats effectively prevented body mass gain, fat accumulation in the liver, and liver enlargement, which otherwise developed in the animals fed FChD only, whereas the weight of the other main organs (heart, liver, kidney, spleen, testicles, and lungs) remained unaltered. CHM was also capable of exerting this effect when administered to animals already in an atherosclerotic, overweight condition. No adverse effects were observed during the 10 weeks of feeding the animals the CHM‐containing diet. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 169–176, 2007
Kinetics of photoinduced birefringence in the guest–host system of poly(methyl methacrylate) doped with azobenzene‐containing crown ethers
Authors: Shimizu Flávio Makoto , Volpati Diogo , Giacometti José Alberto , Sworakowski Juliusz , Janus Krzysztof , Luboch Elżbieta
Published: April 2007

The kinetics of the buildup and decay of photoinduced birefringence was examined in a series of host–guest systems: azobenzene‐containing crown ethers, differing in the size of the crowns, dissolved in a poly (methyl methacrylate) matrix. In all samples, the kinetics of the buildup of the birefringence was reasonably described by a sum of two exponential functions, the time constants being inversely proportional to the intensity of the pumping light and the magnitudes of the signals at the saturation level depending on the pumping light intensity and sample thickness. The dark decays were best described by the stretched exponential function, with the characteristic parameters (time constant and stretch coefficient) being practically independent of the type of crown ether. The time constants of the signal decay were orders of magnitude shorter than the respective constants of the dark isomerization of the azo crown ethers, thus indicating that the process controlling the decay was a relaxation of the polymer matrix and/or a rearrangement of the flexible parts of the crowns. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 130–136, 2007