bluuebunny/crossref_metadata_2025 huggingface dataset:
Class A Biosolids Production by a Low‐Cost Conventional Technology
Authors: Tata Prakasam , Lue‐Hing Cecil , Bertucci James J. , Sedita Salvador J. , Knafl George J.
Published: October 2006

Encouraged by a finding that the pathogen analyses of numerous samples of the final product of the Metropolitan Water Reclamation District of Greater Chicago, Illinois (District), met the U. S. Environmental Protection Agency (U. S. EPA) Class A criteria, the District optimized and codified the operation of its sludge processing trains (SPTs), submitted a petition to the U. S. EPA Pathogen Equivalency Committee for obtaining certification of its SPTs as equivalent to a process to further reduce pathogens, and conducted a 3 year full‐scale study. The objective of the study was to determine whether or not the District's SPTs consistently produced a Class A biosolids final product. The primary conclusion drawn from this optimized and codified operation study was that all batches of the final air‐dried product complied with the Class A criteria as specified by U. S. EPA in the Part 503 regulations.
Statistical Evaluation of Pathogen Inactivation for a Conventional Low‐Cost Technology Class A Biosolids Process
Authors: Tata Prakasam , Lue‐Hing Cecil , Knafl George J.
Published: October 2006

Statistical methods were developed for analyzing the results of a study of pathogen densities for sludge samples taken over the four stages of the solids processing trains (SPTs) operating at the Stickney and Calumet Water Reclamation Plants of the Metropolitan Water Reclamation District of Greater Chicago, Illinois (District). These methods also apply to pathogen density studies for other biosolids processes. Analysis of covariance models were used to estimate expected pathogen densities for individual solids processing stages. Cross‐validation was used to select appropriate analysis of covariance models. Nonparametric methods were used to estimate distributions for pathogen density reductions between solids processing stages and to assess the effect of hypothetical surges and expansions in initial stage pathogen densities on final stage pathogen densities. These statistical analyses demonstrate that the District's SPTs achieve target reductions in enteric virus and viable helminth ova densities with high probabilities. Furthermore, the District's SPTs would still meet U. S. Environmental Protection Agency Class A restrictions for these pathogens with high probabilities, even if the initial stage pathogen densities observed in the study undergo extreme hypothetical surges or extreme hypothetical uniform expansions, that is, exceptionally large isolated bursts of pathogens or exceptionally large sustained increases in pathogens in the feed to the SPTs.
Using Oxidation–Reduction Potential as Septicity Control Parameter During Reclaimed Wastewater Transportation
Authors: Delgado‐Díaz Sebastián , Álvarez Manuel , Rodríguez‐Gómez Luis E. , Aguiar Escolástico
Published: October 2006

During wastewater transportation, chemical and biological transformations may occur. Aerobic, anoxic, and anaerobic conditions exist depending on the presence or absence of dissolved oxygen and oxidized nitrogen compounds. The occurrence of anaerobic conditions has a negative effect on wastewater transportation because of the usual subsequent sulfide generation process. In Tenerife, Spain, reclaimed wastewater used for agricultural purposes is transported via a completely filled gravity pipe, 0.6 m in diameter and 61 km long. Because of the long residence time (approximately 30 to 40 hours), anaerobic conditions typically occur after 5 to 10 hours of flow. Field studies during transportation were conducted from November 1994 to July 1997. This paper describes a study of the evolution of septic conditions (aerobic, anoxic, and anaerobic) and the relationship between septicity and oxidation–reduction potential (ORP), which can predict the occurrence of anaerobic conditions.
Mesophilic Aeration of Autothermal Thermophilic Aerobically Digested Biosolids To Improve Plant Operations
Authors: Murthy Sudhir N. , Novak John T. , Holbrook R. David , Surovik Fred
Published: October 2006

Autothermal thermophilic aerobic digestion (ATAD) has been observed to exhibit a greater polymer demand for acceptable biosolids dewatering when compared with conventional mesophilic aerobic digestion. Field studies indicated that an increase in thermophilic detention time promoted the release of proteins and polysaccharides from the biosolids to the bulk solution with corresponding increases in cationic polymer demand and dewatered biosolids filtrate chemical oxygen demand (COD). Tests indicated that mesophilic aeration reduced the polymer demand necessary for acceptable dewatering through removal of proteins and polysaccharides from solution. Reduction in polymer demand after aeration seems to depend on both thermophilic and mesophilic aerobic detention times, whereas the dewatered cake solids seemed to be unaffected. Other process improvements produced by mesophilic aeration included reduction of odor, filtrate foam, filtrate COD, and filtrate phosphate.
Sequencing Batch Membrane Reactor Treatment: Nitrogen Removal and Membrane Fouling Evaluation
Authors: Choo Kwang‐Ho , Stensel H. David
Published: October 2006

Performance of a laboratory‐scale sequencing batch reactor using a membrane for effluent filtration was investigated in terms of chemical oxygen demand (COD) removal, nitrogen removal, and membrane permeability during long‐term continuous operation treating synthetic wastewater. The reactor was operated with six 4‐hour cycles per day consisting of 0.5, 2.0, and 1.5 hours for fill, aeration, and effluent filtration–idle, respectively. Minimal solids wasting occurred for the first 10 months of operation followed by an 8‐day solids retention time (SRT) for the final 1.5 months. Membrane fouling was controlled by backwashing with aeration for 10 minutes during each cycle. A stable permeate flux of approximately 0.34 (L/m2˙h)/kPa [34 (L/m2˙h)/bar] was achieved and was independent of mixed liquor suspended solids concentrations from 710 to 10 000 mg/L. The reactor effluent turbidity averaged less than 0.20 NTU, and more than 98% COD removal occurred. Nitrogen removal efficiency ranged from 87 to 93% through biological nitrification and denitrification. Most of the nitrate was removed during the mixed and unaerated fill period, but a significant amount of nitrogen was removed by simultaneous nitrification– denitrification (SNdN) during aeration at dissolved oxygen (DO) concentrations less than 3.0 mg/L. The SNdN removal increased with decreasing DO concentration in the reactor, although the nitrification rate was reduced at a low DO concentration. During operation with minimal solids wasting (1400‐day calculated SRT), the average observed biomass yield was approximately 0.03 mg mixed liquor volatile suspended solids/mg COD with an abundance of filamentous organisms in the reactor.
Effect of Residence Times and Flow Reversal on Effluent Quality from Reversible Flow Biological Denitrification Reactors
Authors: Woodbury Bryan L. , Dahab Mohamed F.
Published: October 2006

This paper reports the results of a fixed‐film, two‐stage, reversible flow biological denitrification reactor system operated under flow reversal cycles and decreasing residence times for the removal of nitrate from contaminated groundwater. In this system, the second‐stage (i.e., follow) reactor is operated in series with the first‐stage (i.e., lead) reactor. After a given operational period, the flow regime is reversed so that the follow reactor becomes the lead and vice versa. The reversible flow system was found to be effective in reducing effluent nitrate, nitrite, soluble chemical oxygen demand (SCOD), and total suspended solids concentrations when operated at residence times as short as 30 minutes. Results demonstrate the ability of this system to withstand the stresses associated with low hydraulic residence times and short flow cycles. The 30‐minute residence time had the shortest flow reversal adaptation period than other longer residence times. The rapid acclimation was attributed to biofilm population adaptations and to breakthrough of nitrate and SCOD from the lead reactor, allowing the follow reactor biomass to remain more active with respect to denitrification. The shorter residence times translate to reductions in capital cost on scaled‐up systems.
Effect of Sulfate Reduction on Chemical Oxygen Demand Removal in an Anaerobic Baffled Reactor
Authors: Barber William P. , Stuckey David C.
Published: October 2006

Laboratory studies were conducted to investigate the effect of sulfate reduction on chemical oxygen demand (COD) removal in an eight‐compartment anaerobic baffled reactor (ABR) at two CODto‐sulfate (SO42−) ratios (40 [corresponding to 100 mg/L SO42−] and 8 [500 mg/L SO42−]) with an influent COD concentration of 4000 mg/L. The COD was composed of a carbohydrate (sucrose) and protein (peptone) mixture. Sulfate reduction, which had a maximum rate of 0.22 kg SO42−/kg volatile suspended solids·d, was primarily confined to the first compartment but was incomplete. It was hypothesized that poor scavenging capacity and sulfate deficiency were responsible. The dissolved sulfide concentrations experienced during this work were less than 130 mg/L (or 4% in gaseous phase) and typically less than the levels expected to cause bacterial inhibition; however, various trophic groups, especially acetogenic bacteria, seemed to be acutely inhibited by hydrogen sulfide (H2S). In contrast, low concentrations of reduced sulfide (15 mg/L H2S(aq)) generated from sulfate reduction stimulated reductive methanogenesis. Nevertheless, overall COD removal decreased with increased sulfate addition and seemed to be influenced by residual COD production. The volatile fatty acid results obtained during this work were consistent with literature findings, namely, acetate accumulation and lack of acetoclastic activity, improved propionate use, and inert butyrate use.
Microfiltration of Municipal Wastewater for Disinfection and Advanced Phosphorus Removal: Results from Trials with Different Small‐Scale Pilot Plants
Authors: Gnirss R. , Dittrich J.
Published: October 2006

The Berliner Wasserbetriebe have been conducting a research project on microfiltration of municipal wastewater for disinfection and advanced phosphorus removal since 1992. The goal of this project is to examine whether microfiltration (MF) is a technically feasible and economically competitive process for disinfection and advanced phosphorus removal for secondary effluent. Different smallscale MF systems under investigation performed well. Microfiltration is suitable for reaching low target concentrations of total coliforms (<100/100 mL) and total phosphorus (<50 m g/L). Significant virus removal was also noted, which was unexpected when the trials commenced. This report summarizes a survey of dead‐end MF systems using different membranes and modules. The competitive trial period, with the most suitable polymeric dead‐end MF unit used in parallel with a ceramic dead‐end MF unit showed no advantage over an inorganic membrane. Based on the MF data for operational costs presented and an estimation for capital costs, total costs were estimated to range between U. S. .27–0.54/m3 filtrate. A final evaluation as to which MF system is the most suitable for municipal wastewater treatment will be provided following the conclusion of current large‐scale trials.
Street Stormwater Storage Capacity
Authors: Guo James C.Y.
Published: October 2006

The primary function of a street is to maintain the movement of traffic. Under the assumption that street drainage will be designed to collect stormwater as fast as possible, the street stormwater capacity has been defined as its hydraulic conveyance, estimated by Manning's formula. This practice has resulted in a prevailing experience that street intersections are often flooded. This study presents an investigation on street hydraulic capacity. It is found that the street stormwater capacity at a sump is in fact dictated by the storage capacity rather than the conveyance capacity. A new design methodology is developed in this study to consider the street depression storage as a criterion when sizing a sump inlet. Design parameters required by this method include the local intensity–duration–frequency information, catchment area, runoff coefficient, street transverse slope, and the configuration of the sump area as a fraction of a circle.
Pilot‐Plant Study of Wastewater Sludge Decontamination Using a Ferrous Sulfate Bioleaching Process
Authors: Mercier Guy , Drogui Patrick , Blais Jean‐François , Chartier Myriam
Published: October 2006

The objective of this research was to investigate the performance of the ferrous sulfate bioleaching (FSBL) process in a pilot plant for decontamination and stabilization of wastewater sludge. Batch and continuous experiments, conducted with two 4‐m 3 bioreactors using indigenous iron‐oxidizing bacteria (20% v/v of inoculum) with addition of 4.0 g ferrous sulfate heptahydrate per liter of sludge initially acidified to pH 4.0, were sufficient for effective heavy metal (cadmium, copper, manganese, zinc, and lead) removal yields. The average metal removal yields during the FSBL process were as follows: cadmium (69 to 75%), copper (68 to 70%), manganese (72 to 73%), zinc (65 to 66%), and lead (16%). The FSBL process was also found to be effective in removing both fecal and total coliforms (abatement >5 to 6 log units). The nutrients content (nitrogen, phosphorus, and magnesium) were also preserved in decontaminated sludge.
Simultaneous Nitrification and Denitrification in an Aerobic Reactor with Granular Sludge Originating from an Upflow Anaerobic Sludge Bed Reactor
Authors: Ruan Wenquan , Hua Zhaozhe , Chen Jian
Published: October 2006

Anaerobic granular sludge, obtained from an upflow anaerobic sludge bed reactor at a brewery waste treatment station, was cultured for 3 months under aeration conditions until the diameter of sludge was in the range 1.8 to 2.6 mm. The aerobic granular sludge gathered acquired the ability of catalyzing simultaneous nitrification and denitrification (SND) and was applied in the study of the process of nitrogen removal in a bioreactor. The ratio between chemical oxygen demand (COD) and ammonium‐nitrogen (NH 4 +‐N) concentration in the influent was found to be an important factor influencing the process of SND. The final percentage removal of NH 4 +‐N reached 100% under the optimal condition of 500 mg/L COD and 0.39 NH 4 +‐N/COD. Intermediate products, such as nitrite‐nitrogen and nitrate‐nitrogen, were also analyzed to clarify the SND process with the aerobic granular sludge.
Gas Phase Transport in Gravity Sewers—A Methodology for Determination of Horizontal Gas Transport and Ventilation
Authors: Madsen H. I. , Hvitved‐Jacobsen T. , Vollertsen J.
Published: October 2006

A method was developed for determination of horizontal gas transport and ventilation in gravity sewers. This was achieved by changing the composition of the sewer atmosphere by pulse injection of oxygen gas and subsequently measuring the oxygen concentration in a downstream manhole. Conventional tracer techniques may require sampling and may also affect the environment. The method developed is simple, based on direct monitoring and without environmental or toxic effects. The method was developed based on measurements in an intercepting gravity sewer. The horizontal gas transport processes were quantified by measuring the velocity and dispersion of the gas in the sewer atmosphere. Based on 54 measurements, the gas velocity was found to vary between 0.05 and 0.22 m/s. The coefficients of dispersion were calculated to be in the range 0.05 to 1.1 m2/s. Climatic conditions did not significantly influence the gas phase transport.
Food‐Service Establishment Wastewater Characterization
Authors: Lesikar B. J. , Garza O. A. , Persyn R. A. , Kenimer A. L. , Anderson M. T.
Published: October 2006

Food‐service establishments that use on‐site wastewater treatment systems are experiencing pretreatment system and/or drain field hydraulic and/or organic overloading. This study included characterization of four wastewater parameters (five‐day biochemical oxygen demand [BOD 5]; total suspended solids [TSS]; food, oil, and grease [FOG]; and flow) from 28 restaurants located in Texas during June, July, and August 2002.     The field sampling methodology included taking a grab sample from each restaurant for 6 consecutive days at approximately the same time each day, followed by a 2‐week break, and then sampling again for another 6 consecutive days, for a total of 12 samples per restaurant and 336 total observations.    The analysis indicates higher organic (BOD 5) and hydraulic values for restaurants than those typically found in the literature. The design values for this study for BOD 5, TSS, FOG, and flow were 1523, 664, and 197 mg/L, and 96 L/day‐seat respectively, which captured over 80% of the data collected.
Generation Pattern of Sulfur Containing Gases from Anaerobically Digested Sludge Cakes
Authors: Novak John T. , Adams Gregory , Chen Yen‐Chih , Erdal Zeynep , Forbes Robert H. , Glindemann Dietmar , Hargreaves J. Ronald , Hentz Lawrence , Higgins Matthew J. , Murthy Sudhir N. , Witherspoon Jay
Published: October 2006

Eleven dewatered sludge cakes collected from anaerobic digesters at different treatment plants were evaluated for the amount, type, and pattern of odorous gas production. All but one of the sludge cakes were from mesophilic anaerobic digesters. One was from a thermophilic digester. The pattern and quantities of sulfur gases were found to be unique for each of the samples with regard to the products produced, magnitude, and subsequent decline. The main odor‐causing chemicals were volatile sulfur compounds, which included hydrogen sulfide, methanethiol, and dimethyl sulfide. Volatile sulfur compound production peaked in 3 to 8 days and then declined. The decline was a result of conversion of organic sulfur compounds to sulfide. In one side‐by‐side test, a high‐solids centrifuge cake generated more odorous compounds than the low‐solids centrifuge cake. The data show that anaerobic digestion does not eliminate the odor potential of anaerobically digested dewatered cakes.
16S Ribosomal RNA Tools Identify an Unexpected Predominance of Paenibacillus‐Like Bacteria in an Industrial Activated Sludge System Suffering from Poor Biosolids Separation
Authors: Simpson Joyce M. , Stroot Peter G. , Gelman Steve , Beydilli Inan , Dudley Sandra , Oerther Daniel B.
Published: October 2006

Molecular biology tools targeting 16S ribosomal RNA (16S rRNA) were used to identify a predominant bacterial population in a full‐scale dairy wastewater activated sludge system suffering from poor biosolids separation. Gram and acridine orange staining indicated that viable, Gram‐positive microorganisms were present in samples removed from the influent waste stream and represented approximately 50% of total cell counts in samples removed from the mixed liquor. Subsequently, the “full‐cycle 16S rRNA approach” showed that phylogenetic relatives of Paenibacillus spp., a low guanine‐plus‐cytosine percent DNA‐content, Gram‐positive microorganism, represented up to 30% of total 4,6‐diamidino‐2‐phenylindole (DAPI)‐stained cell counts in samples of mixed liquor. Although fluorescent in situ hybridizations with 16S rRNA‐targeted oligonucleotide hybridization probes identified Paenibacillus‐like spp. in samples removed from the influent waste stream, their abundance was less than 10% of total stained cell counts. Results of this study suggest that Paenibacillus‐like spp. were present in low abundance in the influent waste stream, increased in relative abundance within the treatment system, and should be examined further as a candidate bacterial population responsible for poor biosolids separation. This study demonstrates that the full‐cycle 16S rRNA approach can be used to identify candidate bacterial populations that may be responsible for operational upsets in full‐scale activated sludge systems without prior information from cultivation or microscopic analyses.
Transport of Coliphage PRD1 in a Surface Flow Constructed Wetland
Authors: Vidales‐Contreras Juan A. , Gerba Charles P. , Karpiscak Martin M. , Acuna‐Askar Karim , Chaidez‐Quiroz Cristóbal
Published: October 2006

A tracer study was conducted in a 3‐ha surface flow constructed wetland to analyze transport performance of PRD1, an enteric virus model. The convection‐dispersion equation (CDE), including a first‐order reaction model, adequately simulated transport performance of PRD1 in the wetland under an average hydraulic loading rate of 82 mm/d. Convective velocity (v) and longitudinal dispersion coefficient (D) were estimated by modeling a conservative tracer (bromide) pulse through the wetland. Both PRD1 and bromide were simultaneously added to the entering secondary treated wastewater effluent. The mass of bromide and PRD1 recovered was 76 and 16%, respectively. The PRD1 decay rate was calculated to be 0.3/day. The findings of this study suggest that the CDE model and analytical moment equations represent a suitable option to characterize virus transport performance in surface flow constructed wetlands.
The Psychological Boundaries Delineating Truth and Falsehood
Authors: Kunzendorf Robert G. , Deignan Melissa , Galva Mabel , Latorre Kaitlin , Masotta Erin
Published: October 2006

Subjects completed the Boundary Questionnaire, the Conceptions of Truth Inventory (CTI), and a “false memory” paradigm. Thin boundaries were associated with CTI factors positing that “imaginative insight leads to universal truth,” that “truth transcends factual correctness,” and that “pragmatism leads to universal truth,” whereas thick boundaries were associated with CTI factors positing that “truth is consistent and absolute” and that “religious revelations lead to hidden truth.” In addition, subjects with thin boundaries exhibited “imagination inflation” (“false memory” for a counterfactual event after imagining it), whereas subjects with thick boundaries exhibited “imagination deflation” (greater confidence in the non-occurrence of a counterfactual event after imagining it).
Narcissism and Self-Esteem in the Presence of Imagined others: Supportive versus Destructive Object Representations and the Continuum Hypothesis
Authors: Watson P. J. , Trumpeter Nevelyn , O'Leary Brian J. , Morris Ronald J. , Culhane Scott E.
Published: October 2006

The present investigation tested an assumption of the Continuum Hypothesis that representations of the self are coordinated with representations of others, or “objects.” A sample of 373 university students responded to measures of Self-Esteem, Adaptive Narcissism, Maladaptive Narcissism, Positive Affect, and Negative Affect under normal instructions and then again under procedures in which they imagined themselves in the presence of a Supportive Object that promoted the experience of a “good and happy self” or a Destructive Object associated with a “bad and unhappy self.” Supportive Objects produced decreases in Negative Affect and increases in all other measures, whereas Destructive Objects caused a generally opposite pattern of changes. Data for Maladaptive Narcissism suggested that each type of object was associated with maturational challenges. For both groups, Self-Esteem instability predicted greater overall self-representation instability, but evidence of instability was more obvious in the Destructive than in the Supportive Object condition. These results confirmed, but also revealed a need for refining, the Continuum Hypothesis.
Imagining Metaphorical Actions: Embodied Simulations Make the Impossible Plausible
Authors: Gibbs Raymond W. , Gould Jessica J. , Andric Michael
Published: October 2006

Can people form coherent mental images for metaphorical actions that are physically impossible to perform such as grasping a concept, chewing on an idea, and coughing up a secret? This article reports the findings from two experiments that investigated the products of people's imagining metaphorical and nonmetaphorical actions given different forms of real and imagined bodily engagement. Our hypothesis was that people should be able to form coherent mental images for metaphorical actions because many abstract concepts are partly understood in terms of enduring embodied metaphors. For example, we conceive of “ideas” as physical entities that we can grasp, juggle, hold on to, chew, swallow, digest, and spit out given wide-spread conceptual metaphors like IDEAS ARE PHYSICAL ENTITIES. We argue that our data demonstrate the importance of embodied simulations of action in how people learn to make sense of why certain metaphors have the specific meanings they do, even in cases where these phrases refer to impossible human actions.
The Death of Princess Diana: The Effects of Memory Enhancement Procedures on Flashbulb Memories
Authors: Krackow Elisa , Lynn Steven Jay , Payne David G.
Published: October 2006

This study examined the effects of memory enhancement procedures (i.e., hypnosis, n = 19; context reinstatement/reverse order recall(CR/RO), n = 19; task motivation instructions (TMIs), n = 20) on the fate of flashbulb memories of Princess Diana's death. Three days after Diana's death, participants provided a narrative account and responded to specific questions describing the circumstances under which they learned the news. Eleven to 12 weeks later, participants, selected (from a larger sample, N = 348) on the basis of their initial report of an emotional reaction to Diana's death and report completeness, received one of the three memory enhancement procedures and then completed the original survey. Hypnotized participants' recall was compromised relative to task motivated participant's on measures of consistency in which task motivated participants provided the most consistent recall. CR/RO and TMI participants provided more complete narratives than did hypnosis participants. Prototypical flashbulb memory features were stable (82%) across narratives. However, when the entire narrative was analyzed, statement by statement, consistency declined to 32%.
Modeling the Effect of Density-Dependent Chemical Interference upon Seed Germination
Authors: Sinkkonen Aki
Published: October 2006

A mathematical model is presented to estimate the effects of phytochemicals on seed germination. According to the model, phytochemicals tend to prevent germination at low seed densities. The model predicts that at high seed densities they may increase the probability of seed germination and the number of germinating seeds. Hence, the effects are reminiscent of the density-dependent effects of allelochemicals on plant growth, but the involved variables are germination probability and seedling number. The results imply that it should be possible to bypass inhibitory effects of allelopathy in certain agricultural practices and to increase the efficiency of nature conservation in several plant communities.
2006 Conference of the International Hormesis Society: Stress Response Mechanisms: From Single Cells to Multinational Organizations
Authors: Pech Richard J.
Published: October 2006

Can a literal comparison be made between biological phenomena in organisms and phenomena in human organizations? The evidence provided by simplified but useful examples appears to suggest that a phenomenon simulating hormesis can and does occur in organizational contexts. Similarities between stress response behaviors of organisms and stress response behaviors in organizations are discussed. Cellular stress response mechanisms stimulate and repair, as well as defend the organism against further attacks. Organizational hormesis describes actions that stimulate the organization by increasing its focus and protecting it against future attacks. The common aim for the organism as well as the organization is to increase the probability of survival. The following describes examples of organizational survival that demonstrate a number of hormetic parallels between organisms and organisations.
Radiation Hormesis: The Good, the Bad, and the Ugly
Authors: Luckey T. D.
Published: October 2006

Three aspects of hormesis with low doses of ionizing radiation are presented: the good, the bad, and the ugly. The good is acceptance by France, Japan, and China of the thousands of studies showing stimulation and/or benefit, with no harm, from low dose irradiation. This includes thousands of people who live in good health with high background radiation. The bad is the nonacceptance of radiation hormesis by the U. S. and most other governments; their linear no threshold (LNT) concept promulgates fear of all radiation and produces laws which have no basis in mammalian physiology. The LNT concept leads to poor health, unreasonable medicine and oppressed industries. The ugly is decades of deception by medical and radiation committees which refuse to consider valid evidence of radiation hormesis in cancer, other diseases, and health. Specific examples are provided for the good, the bad, and the ugly in radiation hormesis.
Electrospray ionization mass spectrometric study of mercury complexes of N-heterocyclic carbenes derived from 1,2,4-triazolium salt precursors
Authors: Frański Rafał , Gierczyk Błażej , Schroeder Grzegorz , Pieper Stefan , Springer Andreas , Linscheid Michael
Published: October 2006

By mixing 1,2,4-triazolium salts (precursors of N-heterocyclic carbenes 1–6) with mercury acetate, a number of complexes have been obtained under electrospray ionization condition. Carbenes 1 and 2 contain one carbene center; therefore, they are able to bond only one mercury cation. Carbenes 3–5 contain two carbene centers; therefore, they can bond two mercury cations. Mercury complexes of 1–5 always contain an acetate anion attached to a mercury cation. Carbene 6 also contains two carbene centers; however, its structure allows formation of a complex containing mercury bonded simultaneously to both centers, therefore, the complex that does not contain an acetate anion. The MS/MS spectra taken for complexes of carbenes 1–5 have shown formation of a cation corresponding to N1 substituent (adamantyl or benzyl), and those of complexes of carbenes 3–5 (doubly charged ions) have also shown the respective complementary partner ions. Mercury complex of 2 has yielded some other interesting fragmentation pathways, e.g. a loss of the HHgOOCCH3 molecule. The fragmentation pathway of the mercury complexes of 6 was found to be complicated.
The α
1-adrenolytic and structural evaluation of new pyridoindole derivatives
Authors: Májeková Magdaléna , Šnirc Vladimír , Štolc Svorad , Májek Pavol , Bezáková Želmíra , Sotníková Ružena
Published: October 2006

α1 — adrenolytic activities of pyridoindole derivatives recently synthesized in the Institute of Experimental Pharmacology, Slovak Academy of Sciences, were measured. A characteristic set of derivatives (five active, one with a threshold activity and two inactive) was chosen and an elementary structure-activity study was performed. The structure and energy properties were estimated by quantum-chemical semiempirical AM1 and molecular mechanics methods. The ionization constants pKα of the individual derivatives were calculated by program Pallas or estimated by potenciometric titration. The α
1 blocking activities were measured by rat thoracic aorta model. The experimental model used was not α
1 — adrenoreceptor subtypes specific, however, the α
1D
subtype could be considered to be a predominant type in a rat aorta. The obtained physico-chemical parameters were then compared with the blocking activities of the derivatives and following determining characters for α
1 — adrenolytic activities were determined: 1) the polarity of the substituted phenol ring represented by a map of molecular electrostatic potential and 2) the hexahydro-pyridine nitrogen pKα constant, which represents the ability of the compound to be protonated by physiologic pH.
A new method for the preperative and analytical electrophoresis of cells
Authors: Wilk Anna , Rośkowicz Kinga , Korohoda Włodzimierz
Published: October 2006

In this paper, a new method is described for the horizontal electrophoresis of cells on a density cushion under near-isopycnic conditions. When cell sedimentation is minimized, the electrophoresis of red blood cells (RBC) used as model cells within an anti-convective porous matrix (with pores over 300 μm in diameter) was capable of separating a mixture of human and chicken RBC according to their electrophoretic mobilities. Samples taken from the separated RBC bands show over 90% purity for each species. The simultaneous electrophoresis of several RBC samples carried out under identical conditions permitted the use of comparative data based on the electrophoretic mobility of cells which differ in their surface properties. We believe that this relatively simple system, in which cell sedimentation and convection are minimized, has the potential to be modified and adapted for the separation of other cell types/organelles.
Web‐based text classification in the absence of manually labeled training documents
Authors: Hung Chen‐Ming , Chien Lee‐Feng
Published: October 2006

Most text classification techniques assume that manually labeled documents (corpora) can be easily obtained while learning text classifiers. However, labeled training documents are sometimes unavailable or inadequate even if they are available. The goal of this article is to present a self‐learned approach to extract high‐quality training documents from the Web when the required manually labeled documents are unavailable or of poor quality. To learn a text classifier automatically, we need only a set of user‐defined categories and some highly related keywords. Extensive experiments are conducted to evaluate the performance of the proposed approach using the test set from the Reuters‐21578 news data set. The experiments show that very promising results can be achieved only by using automatically extracted documents from the Web.
Synthesis of Anatase TiO2 Nanoparticles with β‐Cyclodextrin as a Supramolecular Shell
Authors: Li Landong , Sun Xiaohong , Yang Yali , Guan Naijia , Zhang Fuxiang
Published: October 2006

We report a novel, green hydrothermal‐synthesis route to well‐dispersed anatase TiO2 nanoparticles with particle sizes of 9–16 nm in the presence of β‐CD (β‐cyclodextrin). During the synthesis process, the CD‐containing synthesis mixture assembled in both longitudinal and latitudinal directions. Driven by the interaction between molecules, the β‐CDs assembled in the longitudinal direction to form long‐chain compounds, whereas in the latitudinal direction, they tended to form regular aggregates through coordination with the Ti species from the hydrolysis of tetrabutyl titanate. In view of the effect of the coordination and the steric hindrance of β‐CDs as a supramolecular shell, homogeneous nuclei and slow growth of TiO2 crystals during the synthesis process was observed, which was responsible for the formation of uniform TiO2 nanoparticles. The low β‐CD dosage and the high product yield (>90 %) demonstrated well the potential of this synthesis route in the large‐scale industrial production of anatase nanoparticles.
Orbital Overlap and Chemical Bonding
Authors: Krapp Andreas , Bickelhaupt F. Matthias , Frenking Gernot
Published: October 2006

The chemical bonds in the diatomic molecules Li2–F2 and Na2–Cl2 at different bond lengths have been analyzed by the energy decomposition analysis (EDA) method using DFT calculations at the BP86/TZ2P level. The interatomic interactions are discussed in terms of quasiclassical electrostatic interactions ΔEelstat, Pauli repulsion ΔEPauli and attractive orbital interactions ΔEorb. The energy terms are compared with the orbital overlaps at different interatomic distances. The quasiclassical electrostatic interactions between two electrons occupying 1s, 2s, 2p(σ), and 2p(π) orbitals have been calculated and the results are analyzed and discussed. It is shown that the equilibrium distances of the covalent bonds are not determined by the maximum overlap of the σ valence orbitals, which nearly always has its largest value at clearly shorter distances than the equilibrium bond length. The crucial interaction that prevents shorter bonds is not the loss of attractive interactions, but a sharp increase in the Pauli repulsion between electrons in valence orbitals. The attractive interactions of ΔEorb and the repulsive interactions of ΔEPauli are both determined by the orbital overlap. The net effect of the two terms depends on the occupation of the valence orbitals, but the onset of attractive orbital interactions occurs at longer distances than Pauli repulsion, because overlap of occupied orbitals with vacant orbitals starts earlier than overlap between occupied orbitals. The contribution of ΔEelstat in most nonpolar covalent bonds is strongly attractive. This comes from the deviation of quasiclassical electron–electron repulsion and nuclear–electron attraction from Coulomb's law for point charges. The actual strength of ΔEelstat depends on the size and shape of the occupied valence orbitals. The attractive electrostatic contributions in the diatomic molecules Li2–F2 come from the s and p(σ) electrons, while the p(π) electrons do not compensate for nuclear–nuclear repulsion. It is the interplay of the three terms ΔEorb, ΔEPauli, and ΔEelstat that determines the bond energies and equilibrium distances of covalently bonded molecules. Molecules like N2 and O2, which are usually considered as covalently bonded, would not be bonded without the quasiclassical attraction ΔEelstat.
Exploring Base‐Pair‐Specific Optical Properties of the DNA Stain Thiazole Orange
Authors: Jarikote Dilip Venkatrao , Krebs Nils , Tannert Sebastian , Röder Beate , Seitz Oliver
Published: October 2006

Double‐stranded DNA offers multiple binding sites to DNA stains. Measurements of noncovalently bound dye–nucleic acid complexes are, necessarily, measurements of an ensemble of chromophores. Thus, it is difficult to assign fluorescence properties to base‐pair‐specific binding modes of cyanine dyes or, vice versa, to obtain information about the local environment of cyanines in nucleic acids by using optical spectroscopy. The feasibility to stain DNA and simultaneously probe local perturbations by optical spectroscopy would be a valuable asset to nucleic acid research. So‐called FIT probes (forced intercalation probes) were used to pinpoint the location of the DNA stain thiazole orange (TO) in PNA⋅DNA duplexes. A detailed analysis of the base‐pair dependence of optical properties is provided and enforced binding of TO is compared with “classical” binding of free TO‐PRO1. UV‐visible absorbance, circular dichroism (CD) and fluorescence spectroscopy, and melting‐curve analyses confirmed site‐specific TO intercalation. Thiazole orange exhibited base‐specific responses that are not observed in noncovalent dye–nucleic acid complexes, such as an extraordinary dependence of the TO extinction coefficient (±60 % variation of the averaged εmax of 57 000 M−1 cm−1) on nearest‐neighbor base pairs. TO signals hybridization, as shown by increases in the steady‐state fluorescence emission. Studies of TO fluorescence lifetimes in FIT–PNA and in DNA⋅DNA and PNA⋅DNA complexes highlighted four different fluorescence‐decay processes that may be closed or opened in response to matched or single‐mismatched hybridization. A very fast decay process (0.04–0.07 ns) and a slow decay process (2.33–3.95 ns) provide reliable monitors of hybridization, and the opening of a fast decay channel (0.22–0.48 ns) that resulted in an attenuation of the fluorescence emission is observed upon the formation of mismatched base pairs.
Stereoselective Preparation of Six Diastereomeric Quatercyclopropanes from Bicyclopropylidene and Some Derivatives
Authors: von Seebach Malte , Kozhushkov Sergei I. , Schill Heiko , Frank Daniel , Boese Roland , Benet‐Buchholz Jordi , Yufit Dmitry S. , de Meijere Armin
Published: October 2006

Diastereomericmeso‐ andd,l‐bis(bicyclopropylidenyl) (5) were obtained upon oxidation with oxygen of a higher‐order cuprate generated from lithiobicyclopropylidene (4) in 50 and 31 % yield, respectively. Their perdeuterated analoguesmeso‐[D14]‐ andd,l‐[D14]‐5were obtained along the same route from perdeuterated bicyclopropylidene [D8]‐3(synthesized in six steps in 7.4 % overall yield from [D8]‐THF) in 20.5 % yield each. Dehalogenative coupling of 1,1‐dibromo‐2‐cyclopropylcyclopropane (6) gave a mixture of all possible stereoisomers of 1,5‐dicyclopropylbicyclopropylidene16in 69 % yield, from which (Z)‐cis‐16was separated by preparative gas chromatography (26 % yield). The crystal structure ofmeso‐5looks like a superposition of the crystal structures of two outer bicyclopropylidene units (3) and one inner s‐trans‐bicyclopropyl unit, whereas the two outer cyclopropyl moieties adopt agaucheorientation with respect to the cyclopropane rings at the inner bicyclopropylidene units in (Z)‐cis‐16. Birch reduction with lithium in liquid ammonia ofmeso‐5andd,l‐5gave two pairs of diastereomeric quatercyclopropanestrans,trans‐(R*,S*,R*,S*)‐17/cis,trans‐(R*,S*,R*,R*)‐18andtrans,trans‐(R*,S*,S*,R*)‐19/cis,trans‐(R*,S*,S*,S*)‐20in 97 and 76 % yield, respectively, in a ratio 9:1 for every pair. The latter diastereomer was also obtained as the sole product by Birch reduction of (Z)‐cis‐16in 96 % yield. Under the same conditions, tetradecadeuterio analoguestrans,trans‐[D14]‐(R*,S*,R*,S*)‐17/cis,trans‐[D14]‐(R*,S*,R*,R*)‐18(8:1) andtrans,trans‐[D14]‐(R*,S*,S*,R*)‐19/cis,trans‐[D14]‐(R*,S*,S*,S*)‐20(12:1) were prepared frommeso‐[D14]‐5andd,l‐[D14]‐5in 37 and 63 % yield, respectively. Reduction ofmeso‐5with diimine gave thecis,cis‐quatercyclopropane (S*,S*,R*,R*)‐21as the main product (58 % yield) along with thecis,trans‐diastereomer (S*,S*,R*,S*)‐18(29 % yield). Thus, five of the six possible diastereomeric quatercyclopropanes were obtained frommeso‐5,d,l‐5, and (Z)‐cis‐16. The X‐ray crystal structure analyses oftrans,trans‐(R*,S*,R*,S*)‐17andcis,cis‐(S*,S*,R*,R*)‐21revealed for the both an unusual conformation in which the central bicyclopropyl unit adopts an s‐trans‐(antiperiplanar) orientation withϕ=180.0°, and the two terminal bicyclopropyl moieties adopt a synclinal conformation withϕ=49.8 and 72.0°, respectively. In solution the vicinal coupling constants 〈3JH,H〉 intrans,trans‐(R*,S*,R*,S*)‐[D14]‐17,trans,trans‐(R*,S*,S*,R*)‐[D14]‐19,trans,cis‐(R*,S*,R*,R*)‐[D14]‐18andtrans,cis‐(R*,S*,S*,S*)‐[D14]‐20were found to be 4.1, 4.7, 5.9 and 5.9 Hz, respectively. This indicates a predominance of the all‐gaucheconformer in (R*,S*,R*,S*)‐17and a decreasing fraction of it in this sequence of the other diastereomers.
Structural and Magnetic Resolution of a Two‐Step Full Spin‐Crossover Transition in a Dinuclear Iron(II) Pyridyl‐Bridged Compound
Authors: Amoore Jarrod J. M. , Kepert Cameron J. , Cashion John D. , Moubaraki Boujemaa , Neville Suzanne M. , Murray Keith S.
Published: October 2006

A dinuclear iron(II) complex containing the new pyridyl bridging ligand, 2,5‐di(2′,2′′‐dipyridylamino)pyridine (ddpp) has been synthesised and characterised by single‐crystal X‐ray diffraction, magnetic susceptibility and Mössbauer spectral methods. This compound, [Fe2(ddpp)2(NCS)4]⋅4 CH2Cl2, undergoes a two‐step full spin crossover. Structural analysis at each of the three plateau temperatures has revealed a dinuclear molecule with spin states HS–HS, HS–LS and LS–LS (HS: high spin, LS: low spin) for the two iron(II) centres. This is the first time that resolution of the metal centres in a HS–LS ordered state has been achieved in a two‐step dinuclear iron(II) spin‐crossover compound. Thermogravimetric data show that the dichloromethane solvate molecules can be removed in two distinct steps at 120 °C and 200 °C. The partially de‐solvated clathrate, [Fe2(ddpp)2(NCS)4]⋅CH2Cl2, undergoes a one‐step transition with an increased transition temperature with respect to the as synthesised material. Structural characterisation of this material reveals subtle changes to the coordination geometries at each of the iron(II) centres and striking changes to the local environment of the dinuclear complex. The fully de‐solvated material remains high spin over all temperatures. Interestingly, the solvent can be re‐introduced into the monosolvated solid to achieve complete conversion back to the original two‐step crossover material, [Fe2(ddpp)2(NCS)4]⋅4 CH2Cl2.
Conformational Control of [26]Hexaphyrins(1.1.1.1.1.1) by meso‐Thienyl Substituents
Authors: Suzuki Masaaki , Osuka Atsuhiro
Published: October 2006

Conformational preference and chemical stability of meso‐aryl‐substituted [26]hexaphyrins(1.1.1.1.1.1) ([26]ArH) depend upon meso‐aryl substituents. Although only a planar and rectangular conformation (type‐II conformation) has been identified for [26]ArH so far, we have demonstrated here that a different conformation with all the pyrroles pointing inward (type‐I conformation) is preferred for [26]ArH (7 and 11‐I) bearing small 2‐thienyl or 3‐thineyl substituents at 15‐ and 30‐positions. Both type‐I and type‐II [26]ArH exhibit diatropic ring currents, reflecting aromatic character. Type‐I [26]ArH, such as 7 and 11‐I, have been shown to serve as an effective ligand for PdII ions to provide bis‐PdII complexes 12 and 13 with N3C1 coordination through facile CH bond activation.
Long‐term outcome of hematuria home screening for bladder cancer in men
Authors: Messing Edward M. , Madeb Ralph , Young Terry , Gilchrist Kennedy W. , Bram Lora , Greenberg E. Barry , Wegenke John D. , Stephenson Laura , Gee Jason , Feng Changyong
Published: October 2006

BACKGROUND.

The objectives of this study were to determine whether bladder cancer (BC) screening in healthy men could lead to earlier detection and reduced BC mortality compared with unscreened men and to determine long‐term outcomes of a geographically defined, unscreened population with newly diagnosed BC.

METHODS.

In 1987 and from 1998 to 1992, 1575 men ages 50 years and older who were solicited from well patient rosters in clinics in and around Madison, Wisconsin, tested their urine repetitively with a chemical reagent strip for hemoglobin. Participants who had positive test results underwent standard urologic evaluation. BC grades and stages and the outcomes of men with BC detected by screening were compared with the grades, stages, and outcomes of 87% of men ages 50 years and older with newly diagnosed BC who were reported to the Wisconsin Tumor Registry in 1988 (n = 509 men).

RESULTS.

Two hundred fifty‐eight screening participants (16.4%) were evaluated for hematuria, and 21 participants (8.1%) were diagnosed with BC. Proportions of low‐grade (Grade 1 and 2) superficial (Stage Ta and T1) versus high‐grade (Grade 3) superficial or invasive (Stage ≥ T2) cancers in screened men (52.4% vs. 47.7%) and in men from the tumor registry (60.3% vs. 39.7%) were similar (P = .50). The proportion of high‐grade superficial or invasive BCs that were invasive were lower in screened men (10%) than in unscreened men (60%; P = .002). At 14 years of follow‐up, no men with screen‐detected BC had died of BC, whereas 20.4% of men with unscreened BC had died of BC (P = .02).

CONCLUSIONS.

Screening effected the early detection of BC and may reduce mortality from BC compared with BC that is diagnosed at standard clinical presentation. Cancer 2006. © 2006 American Cancer Society.