bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Rain and Temperature on the Performance of Constructed Reed Beds
Authors: Manios T. , Millner P. , Stentiford E.I.
Published: October 2006

In this paper, the importance of rain and temperature on the performance of reed beds is examined. Data for 5‐day biochemical oxygen demand (BOD5), total suspended solids (TSS), and ammonia‐nitrogen (NH3–N) removal from 16 different reed beds in England were correlated with local weather data for rainfall and temperature. Linear regression and curvilinear regression methods were used to assess if any correlation existed. Data analysis occurred in three stages. First, the equation used for the design of the beds was transformed to a linear equation to compare BOD5 removal values and monthly average ambient temperature. The transformed equation was tested with data from all of the reed beds, but the correlation was poor. Second, monthly average rainfall and temperature values were compared with percent removal of BOD5, TSS, and NH3–N using curvilinear regression. This approach failed to produce any significant correlation. Finally, curvilinear regression was used to examine performance data with daily rainfall for two of the reed beds. This approach also failed to show any correlation between temperature or rain fall and the performance of the beds.
Steady‐State Modeling of Composition and Production of Activated Sludge
Authors: Yuen Weng Ah
Published: October 2006

The mathematical model used for computing the composition and production of activated sludge is derived from the method of material balance. This model is a refinement of the earlier Chudoba–Tucek steady‐state model, and it is applicable to single‐sludge systems with or without primary clarification. Solids composition and production are expressed explicitly as a function of solids retention time. The new model contains two variable parameters that are characteristic of the influent and can be easily determined using laboratory data. Applications to the sizing of solids processing facilities and computation of the true food‐to‐microorganism ratio introduced by the author are illustrated.
Characterization of Simultaneous Nutrient Removal in Staged, Closed‐Loop Bioreactors
Authors: Daigger Glen T. , Littleton Helen Xiaoxin
Published: October 2006

This research was conducted in the context of an overall research project directed at better understanding and controlling simultaneous biological nutrient removal (SBNR) in full‐scale wastewater treatment plants. The basic hypothesis of the overall research is that three general mechanisms are responsible for SBNR and that all three can operate, to different degrees, within any biological nutrient removal (BNR) system. The three mechanisms are (1) biological reactor (bioreactor) mixing patterns that allow the anoxic and anaerobic zones necessary for BNR to develop, referred to as the bioreactor macroenvironment, (2) the development of anoxic and anaerobic zones within the floc, referred to as the floc microenvironment, and (3) the presence of novel microorganisms. System design and operating parameters will determine the relative importance of each mechanism. The objective of the overall research project is to identify the factors affecting the relative contributions of the three mechanisms to SBNR, thereby allowing SBNR to be implemented and controlled more effectively in full‐scale plants. In the research reported in this paper the operating characteristics of seven full‐scale wastewater treatment plants using the staged, closed‐loop bioreactor process known as Orbal were evaluated to determine the degree of SBNR occurring. Low effluent total nitrogen concentrations from a process without distinct anoxic zones indicate that simultaneous nitrification and denitrification occur reliably in these facilities. Nitrogen removal is encouraged at these facilities by use of solids retention times sufficiently long to allow nitrifiers to grow under the low dissolved oxygen concentrations in channel 1 of the process. Environmental conditions are relatively uniform throughout each channel, and distinct anoxic and aerobic zones do not seem to form. This suggests that the anoxic conditions necessary for denitrification may develop principally within the biological flocs. Biological nitrogen removal was characterized using the International Association on Water Quality Activated Sludge Model Number 1. Influent and effluent total phosphate and biochemical oxygen demand data and microbiological observations suggest that biological phosphorus removal occurs. Distinct anaerobic zones were not observed, but anaerobic conditions may develop within the lower portion of channel 1. These systems are good candidates for further study of SBNR.
Experience with Biological Nutrient Removal at Low Temperatures
Authors: Ydstebø Leif , Bilstad Torleiv , Barnard James
Published: October 2006

Operating experience for the first enhanced biological phosphorus (EBPR) and biological nutrient removal (BNR) plant in Norway are summarized. The primary objective during the first years of operation was to remove phosphorus at low temperatures both in an EBPR mode and a BNR mode. Enhanced biological phosphorus removal was accomplished at 5 °C with 0.6 mg/L total phosphorus in the effluent, and BNR was achieved at 6 to 8 °C with an average of 0.25 mg/L phosphorus and 5.3 to 9.6 mg/L nitrogen in the effluent. Solids were separated by gravity settling only. Sufficient solids retention time resulted in biological phosphorus and nitrogen removal at low temperatures with two‐thirds of the sludge production compared with chemical phosphorus removal. In the approximate plug‐flow biological reactor, a completely stirred tank reactor with seven compartments, a mixed liquor suspended solids concentration of 6000 to 8000 mg/L was maintained because of the excellent settling characteristics of the sludge (diluted sludge volume index 5 60 to 80 mL/g). Plug‐flow mixing characteristics result in a substrate gradient that promotes growth of rapid‐settling bacteria and depresses growth of filamentous bacteria. Organic reduction in the anaerobic and anoxic zones results in a low organic loading rate to the aerobic zones with subsequent favorable conditions for nitrification.
Interpreting the Response to Loading Changes in a Mixed‐Culture Completely Stirred Tank Reactor
Authors: de Silva D.G. Viraj , Rittmann Bruce E.
Published: October 2006

Mathematical modeling and carefully controlled laboratory experiments are used to quantify the relationships among nitrifying and heterotrophic bacteria and the key constituents of effluent quality. Mathematical model results are used to interpret experimentally measured traditional parameters, such as soluble chemical oxygen demand (COD) and total biomass. Although total biomass declines with a decrease in influent COD loading, soluble effluent quality remains nearly the same because the effluent soluble COD is controlled by biomass‐associated products. Increases in ammonia‐nitrogen (NH4+–N) loading result in increases in nitrifier biomass, and the active heterotrophs also increase as a result of formation of soluble microbial products (SMP) by autotrophic nitrifiers. However, increased NH4+–N loading causes a steady increase in effluent soluble COD, indicating that the SMP production by nitrifiers is only partially used by the heterotrophs. During the nonsteady‐state period after a loading change, nitrification responds more slowly than heterotrophic processes and controls the time needed to reach the new steady state.
Variation of Oxidation–Reduction Potential Along the Breakpoint Curves in Low‐Ammonia Effluents
Authors: Devkota Laxman M. , Williams Damon S. , Matta John H. , Albertson Orris E. , Grasso Domenic , Fox Peter
Published: October 2006

This study was part of an integrated series of investigations conducted at the 6.6 m3/s (150 mgd) City of Phoenix, Arizona, 91st Avenue Wastewater Treatment Plant to improve the chlorination system and optimize chlorine use after the plant was converted to a nitrification– denitrification (NdeN) plant. The objective of this study was to evaluate chlorine breakpoint behavior and assess oxidation–reduction potential (ORP) with different regimes of the breakpoint curve to reflect ORP behavior in a mixed oxidant and reductant environment typical of a chlorine disinfection system in an NdeN plant. The information was also useful for confirming the results of earlier studies on the fate of nitrite‐nitrogen (NO2−–N) in chlorine reactions, the phenomenon of microbreakpoint formation, and the relative competition for chlorine between ammonia and organics and between ammonia and other inorganics including NO2−–N. Laboratory analysis included measurement of the chlorine species (free chlorine and mono‐, di‐, and trichloramines) and NO2−–N, nitrate‐nitrogen, ammonia, pH, dissolved oxygen, and ORP in low‐ammonia effluents (effluents spiked with various amounts of ammonia) after addition of various chlorine doses. The study indicated that the overall shape of ORP curves follows the pattern of the breakpoint curves. However, the ORP curves were relatively flat at the monochloramine hump region of the curve. Also, ORP increased sharply at the beginning of the monochloramine region and at the beginning of the free chlorine region. The ORP curves eventually flattened again after the initial steep rise. Thus, at the flat portions of the curve, a marginal advantage could be derived with further increases in chlorine dose, and contact time becomes a critical factor in disinfection efficiency. A dip in the ORP curve was invariably observed at the breakpoint even though the dip was of a lesser degree than that of the residual curve. Greater concentrations of dichloramine (which have a greater ORP than monochloramine) expected at the downswing of the breakpoint curve could not sustain the maximum ORP levels observed at the monochloramine region. This suggested that organochloramines may also be a factor in the ORP dip at the breakpoint. Finally, ORP did not vary in direct proportion to total chlorine residual or in direct proportion to the concentration of individual chlorine residual species. Implications of these results are comparatively discussed with reference to the two methods of chlorination control: chlorine‐residual‐based control and ORP‐based control.
Optimizing Dewatering of Biosolids from Autothermal Thermophilic Aerobic Digesters (ATAD) Using Inorganic Conditioners
Authors: Murthy Sudhir N. , Novak John T. , Holbrook R. David
Published: October 2006

Biosolids obtained through the autothermal thermophilic aerobic digestion (ATAD) process exhibit greater polymer demand for dewatering than those obtained through conventional mesophilic aerobic digestion processes. An increase in ATAD retention time and operating temperature resulted in an increase in proteins and polysaccharides in solution, and this resulted in a corresponding increase in cationic polymer demand and an increase in dewatered cake filtrate chemical oxygen demand (COD). Alternative chemical conditioners were used to minimize polymer consumption. Coagulation of solution phase biological polymers (proteins and polysaccharides) using ferric chloride or alum was extremely effective in reducing cationic polymer conditioning demand and dewatered cake filtrate COD. Ferric chloride and alum in laboratory experiments were also able to precipitate and remove phosphate, thus preventing its recycle to the influent of the plant.
Investigating the Capacity of an Activated Sludge Process to Reduce Volatile Organic Compounds and Odor Emissions
Authors: Barbosa Vera , Hobbs Phil , Sneath Robert , Burgess Joanna , Callan Joanne , Stuetz Richard
Published: October 2006

The effects of hydrogen sulfide (H 2S) diffusion into activated sludge (AS) on odor and volatile organic compound (VOC) concentrations in offgas were studied over an 8‐week period. Most VOCs detected in the offgas of both aeration tanks were aromatic hydrocarbons. The VOC concentrations generally decreased when H 2S was introduced to the AS compared with the control, indicating a negative effect of H 2S on VOC removal. Two volatile organic sulfur compounds present in the test AS offgas showed an increase followed by a decrease during H 2S peak loads. Six VOCs and odor concentration increased during the introduction of an H 2S peak; however no correlation was observed between H 2S and odor concentration. The increase in odor concentration resulted from the increase in the concentration of six aromatic VOCs, which had their removal slowed down during a 100‐ppmv H 2S peak. Activated sludge diffusion provides effective H 2S removal with minimal affect on odor emissions.
Evaluation of the Persistence of Micropollutants Through Pure‐Oxygen Activated Sludge Nitrification and Denitrification
Authors: Levine Audrey D. , Meyer Michael T. , Kish George
Published: October 2006

The persistence of pharmaceuticals, hormones, and household and industrial chemicals through a pure‐oxygen activated sludge, nitrification, denitrification wastewater treatment facility was evaluated. Of the 125 micropollutants that were tested in this study, 55 compounds were detected in the untreated wastewater, and 27 compounds were detected in the disinfected effluent. The persistent compounds included surfactants, fire‐retardant chemicals, pesticides, fragrance compounds, hormones, and one pharmaceutical. Physical‐chemical properties of micropollutants that affected partitioning onto wastewater solids included vapor pressure and octanol‐water partition coefficients.
Biosolids‐Amended Soils: Part I. Effect of Biosolids Application on Soil Quality and Ecotoxicity
Authors: Banks M. K. , Schwab A. P. , Cofield N. , Alleman J. E. , Switzenbaum M. , Shalabi J. , Williams P.
Published: October 2006

Investigations of potential risk from biosolids generally indicate that land application does not threaten human or ecosystem health, but questions continue to arise concerning the environmental effects of this practice. This research project was initiated to evaluate ecotoxicity resulting from the amendment of soils with biosolids from municipal wastewater treatment plants. Toxicity was evaluated using standard tests, including earthworm mortality, growth, and reproduction; seedling germination and root elongation; microbial respiration; and nematode mortality and reproduction. Nineteen municipal wastewater treatment plants were identified to participate in an initial screening of toxicity, and five were chosen for a more detailed evaluation. In addition, two soils with historically high applications of high‐metal biosolids were evaluated. Contaminants examined were zinc, copper, nickel, chromium, arsenic, cadmium, lead, and coplanar polychlorinated biphenyls (PCBs). Single applications had no effect on soil metal concentrations. Coplanar PCBs were not detectable in any of the soils or biosolids. All target organisms were sensitive to reference toxicants. Limited toxicity was observed in a small number of the amended soils, but no patterns emerged. Approximately one‐half of the negative effects of biosolids on bioindicators could be attributed to routine properties, such as slight depression of pH and/or elevated salinity. None of the accumulated metal concentrations were excessive, and most would not be considered elevated. These observations suggest that current regulations for application of biosolids to soils are providing adequate ecosystem protection.
Modeling the Entrepeñas Reservoir
Authors: Wiese Bernd U. , Palancar María C. , Aragón José M. , Sánchez Fernando , Gil Roberto
Published: October 2006

The Entrepeñas Reservoir is a monomictic reservoir located in River Tagus (Spain). The aim of this work is to establish a feasible model to predict the depth of the thermocline that is developed in the reservoir during the period of natural thermal stratification. Entrainment, eddy diffusion, inflow of external energy, and other factors are considered to calibrate the parameters of the model. The methodology involves the measure of actual temperature and electrical conductivity profiles, use of meteorological data and reservoir parameters, and selection and application of several models from the literature. The calculations and predictions are integrated to a software packet that is able to predict thermocline depth and water temperature profile during a 1‐year period on a day‐by‐day basis. In the thermocline depth, the prediction error, on the basis of real data, is less than 6% and, in the water temperature, it is 2°C.
Evaluation of Primary and Secondary Treated and Disinfected Wastewater Irrigation of Tomato and Cucumber Plants Under Greenhouse Conditions, Regarding Growth and Safety Considerations
Authors: Manios T. , Papagrigoriou I. , Daskalakis G. , Sabathianakis I. , Terzakis S. , Maniadakis K. , Markakis G.
Published: October 2006

Tomato and cucumber seedlings were distributed into 10 groups (five for each plant) of 15 plants each. The plants were irrigated for 10 weeks with primary treated wastewater (group A), secondary treated wastewater (group B), chlorinated secondary treated wastewater (group C), a fertilizer dilution (group F), and tap water (group M). All precautions were taken to secure that there was no direct contact between the wastewater and the edible portions of the crops. During this period and on a weekly basis, the height and number of leaves was monitored, while, at the end, the dry weight of leaves, stems, and roots for each plant of each group was measured. Based on these growth parameters, both types of plant in groups A and F recorded the most significant development compared to the other three groups. The plants irrigated with tap water recorded the smallest development, in every case. Plants in groups B and C were similar, with a slight (but not significant) superiority for the plants irrigated with secondary treated wastewater, probably as a result of some phytotoxic effects of residual chloride in the chlorinated wastewater. The presence of nutrients and specifically nitrogen in the various solutions explains the differences satisfactorily. The vegetables grown on the plants of each group were harvested, and their surface tissue analyzed for total coliforms (TC) and enterococci (EC). Tomatoes grown on the plants of groups A and B recorded the highest values for TC, with 505 and 490 cfu/g, respectively, whereas, for cucumbers, those values were 342 and 450 cfu/g, respectively. Enterococci were detected on the surface of harvested vegetables from groups A and B, but the small number of cases and their random character cannot support any strong relations between the used wastewater and their presence. The TC values in group C were very low, far lower than those if group F. No EC were found in either group C or group F. These primary results suggested that irrigation with appropriate disinfected wastewater, even of such high‐risk cultivations of vegetables eaten raw, should not be discarded completely as unsafe, but be reconsidered and studied further. However, the use of undisinfected wastewater in such greenhouse cultivations, where all safety precautions have been taken to prevent any contact of the fruits with the soil or the wastewater, does not prove to be 100% safe.
Programming in Pairs with Alice to Improve Confidence, Enjoyment, and Achievement
Authors: Bishop-Clark Cathy , Courte Jill , Howard Elizabeth V.
Published: October 2006

Students in an introductory computing class participated in a study investigating the impact of using a graphics programming environment (Alice) and pair-programming on confidence, enjoyment and achievement. Sixty-four participants completed a short questionnaire and a content pre-test about computer programming concepts. Students were then assigned to one of two groups: individual or paired. The pairs completed a tutorial on Alice and then completed a short assignment over a period of one week working as a team of two. The individuals completed the same tutorial and assignment but completed it alone. Lastly, all participants took the same questionnaire and content post-test. The results showed that all students experienced increased confidence in programming, that students in pairs enjoyed programming more than students who worked individually, and that all students performed significantly better on the content post-test.
Cd(II) extraction in PEG-based two-phase aqueous systems in the presence of iodide ions. Analysis of PEG-rich solid phases
Authors: Bulgariu Laura , Bulgariu Dumitru , Sârghie Ioan , Măluṭan Theodor
Published: October 2006

Cd(II) plus iodide species were extracted into PEG-rich phases in the aqueous PEG(1550)-(NH4)2SO4 system at pH 2.05–7.12. IR spectra show that increasing (NH4)2SO4 solution acidity does not protonate PEG ether oxygen atoms, but decreases water content in the PEG-rich phases. Metallic species’ extraction into the PEG predominantly alters how water molecules bind to polymer chains; the changes in their absorption bands depend on pH. Microscopy shows that “fixation” of the extracted metal in the PEG-rich phase occurs by specific interactions which depend on the species. These also determine changes in the polymer chains’ conformation.
Composition and variability of soil solutions as a measure of human impact on protected woodland areas
Authors: Walna Barbara
Published: October 2006

A study was made of the sandy and loamy soils of the woodland areas of the Wielkopolski National Park (Poland) affected by acid rain. The basic properties of the soils were determined, revealing their strong acidification, poor buffering power, and the possibility of aluminium release. An analysis was made of the content of soluble, exchangeable, organic, amorphous, and free forms of aluminium. The concentration of exchangeable aluminium exceeded that of the form dissolved in soil water several times to tens of times.

In soil solutions Ca/Al ratios in some horizons show very low values that could induce a nutrient deficit. In the sandy profiles the ratio even drops below the critical level of 0.1. In the surface horizon the dominant cation at all the sites is the aluminium ion.

An analysis of anions shows a dominance of sulphate and chloride ions. In autumn nitrites were recorded at all depth levels, while in spring only in the surface layers. The highest fluoride concentrations were found to occur in profiles situated the closest to the emission source of fluorine compounds. The markedly higher concentrations of ammonium than nitrate ions can lead to increased acidification and eutrophication of the soil.
New oxadiazole derivatives as promising electron transport materials: synthesis and characterization of thermal, optical and electrochemical properties
Authors: Liu Chengbin , Zhao Ping , Huang Wei
Published: October 2006

2,5-bis-(4-biphenyl)-yl-1,3,4-oxadiazole (1a), 2,5-bis-(4-(6,8-difluoro)-biphenyl)-yl-1,3,4-oxadiazole (1b) and 2,5-bis-(4-(spiro-fluorenyl)-phenyl)-yl-1,3,4-oxadiazole (1c) were designed, synthesized and characterized. 1a–c were easily obtained from Suzuki reactions between 2,5-bis-(4-bromo-phynyl)-[1,3,4]oxadiazole (2) and aromatic boronic acids (3). They were characterized by 1H-NMR, DSC, TGA, UV-Vis, photoluminescence (PL) spectrometry and CV. The melting temperatures (T
m) of 1a–c are 237, 208 and 370 °C, respectively, much higher than that of 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD, T
m = 136 °C). The oxidation potentials of 1a–c are 1.86, 1.94 and 1.18 V, and their reduction potentials are −2.31, −2.22 and −2.27 V, respectively, indicating that the introduction of electronegative oxadiazole unit lowers the electron density in molecules and enhances their stabilities. The LUMO/HOMO energy levels of 1a–c are as low as −2.39/−6.56, −2.48/−6.69 and −2.43/−5.88 eV, respectively. The good thermal stabilities and low orbital levels of 1a–c make them promising electron-transporting or hole-blocking materials for organic optoelectronic devices.
Federal judge slated to keynote at CPR leadership award dinner
Authors: Bleemer Russ
Published: October 2006

A keynote speaker is named for the CPR Corporate Leadership Award Dinner next month in New York, and registration is still open for soon‐to‐be‐held special arbitrator training sessions for lawyers and for business executives
Mediating the deal: How to maximize value by enlisting a neutral's help at and around the bargaining table
Authors: Goldberg Stephen B.
Published: October 2006

Stephen B. Goldberg, of Evanston, Ill., explains how mediators can help a party's internal deliberations leading up to a transaction
Back to Buckeye: Clarifying an arbitrator's jurisdiction
Authors: McLaughlin Joseph T. , Scanlon Kathleen M. , Clare James
Published: October 2006

Looking back to this year's sole ADR‐related U.S. Supreme Court decision, Joseph T. McLaughlin, Kathleen M. Scanlon and James Clare, of New York, revisit Buckeye Check Cashing Inc. v. Cardegna, and explain why it reaches further in supporting an arbitrator's jurisdiction than it initially appeared
More Florida development: How a pro se plaintiff avoided mediation
Authors: Bleemer Russ
Published: October 2006

Mediation increasingly faces court challenges. A novel approach mined from a Florida court rule worked to defeat in a state appeals court a trial court's mediation order for a pro se plaintiff—who nevertheless was held in contempt for violating the invalidated order
Proteinglycosylierung, konserviert von der Bäckerhefe bis zum Menschen: Ein Modellorganismus hilft bei der Aufklärung menschlicher Erbkrankheiten
Authors: Lehle Ludwig , Strahl Sabine , Tanner Widmar
Published: October 2006

Proteinmodifikationen durch Saccharide sind in großer Zahl bekannt. Der vorliegende Aufsatz konzentriert sich auf zwei Typen von Modifikationen, die Protein‐N‐Glycosylierung und die Protein‐O‐Mannosylierung, die mit wenigen Ausnahmen von Hefe bis Mensch im Laufe der Evolution konserviert geblieben sind. Sie sind dadurch gekennzeichnet, dass die Glycosylierungsprozesse im endoplasmatischen Reticulum der Zellen beginnen und im Golgi‐Apparat fortgesetzt werden und dass die Anfangsschritte über dolicholaktivierte Vorstufen verlaufen. In der gentechnisch einfach handhabbaren Bäckerhefe Saccharomyces cerevisiae sind die beiden Prozesse molekularbiologisch am besten untersucht worden. Dies ist der Hauptgrund dafür, dass zahlreiche genetisch bedingte, schwerwiegende Entwicklungsstörungen bei Kindern, wie das CDG (Congenital Disorder of Glycosylation) und die kongenitalen Muskeldystrophien mit neuronalen Migrationsdefekten, mithilfe der Hefe aufgeklärt werden konnten.
Performance‐related differences of bibliometric statistical properties of research groups: Cumulative advantages and hierarchically layered networks
Authors: Raan Anthony F. J. van
Published: October 2006

In this article we distinguish between top‐performance and lower‐performance groups in the analysis of statistical properties of bibliometric characteristics of two large sets of research groups. We find intriguing differences between top‐performance and lower‐performance groups, and between the two sets of research groups. These latter differences may indicate the influence of research management strategies. We report the following two main observations: First, lower‐performance groups have a larger size‐dependent cumulative advantage for receiving citations than top‐performance groups. Second, regardless of performance, larger groups have fewer not‐cited publications. Particularly for the lower‐performance groups, the fraction of not‐cited publications decreases considerably with size. We introduce a simple model in which processes at the microlevel lead to the observed phenomena at the macrolevel. Next, we fit our findings into the novel concept of hierarchically layered networks. In this concept, which provides the “infrastructure” for the model, a network of research groups constitutes a layer of one hierarchical step higher than the basic network of publications connected by citations. The cumulative size advantage of citations received by a group resembles preferential attachment in the basic network in which highly connected nodes (publications) increase their connectivity faster than less connected nodes. But in our study it is size that causes an advantage. In general, the larger a group (node in the research group network), the more incoming links this group acquires in a nonlinear, cumulative way. Nevertheless, top‐performance groups are about an order of magnitude more efficient in creating linkages (i.e., receiving citations) than lower‐performance groups. This implies that together with the size‐dependent mechanism, preferential attachment, a quite common characteristic of complex networks, also works. Finally, in the framework of this study on performance‐related differences of bibliometric properties of research groups, we also find that top‐performance groups are, on average, more successful in the entire range of journal impact.
The Mg‐Oppenauer Oxidation as a Mild Method for the Synthesis of Aryl and Metallocenyl Ketones
Authors: Kloetzing Ralf J. , Krasovskiy Arkady , Knochel Paul
Published: October 2006

Magnesium alkoxides undergo a hydride‐transfer oxidation with benzaldehyde as the oxidant. This magnesium variant of the Oppenauer oxidation was used for the synthesis of polyfunctional biaryl ketones. LiCl was found to promote this reaction by enhancing the solubility of magnesium alkoxides. This mild oxidation method was especially useful for preparing ketones bearing a metallocenyl unit as well as various new ferrocenyl ketones and tricarbonylchromium complexes. This last class of ketones was reduced with the CBS catalyst (CBS=Corey–Bakshi–Shibata, diphenyl oxazaborolidine) to chiral benzhydrol complexes with high enantioselectivity enabling an asymmetric synthesis of electron‐rich or ‐poor benzhydryl alcohols (up to 94 % ee).
Transitory uptake of serotonin in the developing sensory pathways of the common marmoset
Authors: Lebrand C. , Gaspar P. , Nicolas D. , Hornung J.P.
Published: October 2006

Serotonin (5‐HT) affects brain development during sensitive developmental periods. In rodents, transient sites of high affinity capture of 5‐HT were demonstrated in the primary sensory neurons and in the sensory thalamocortical afferents. This uptake is required to adjust 5‐HT receptor stimulation during the formation of sensory maps. To determine whether similar mechanisms exist in primates, we analyzed staged embryos and postnatal pups in the common marmoset (total gestation time, 142 days). Immunocytochemical analyses were performed using antisera to 5‐HT, to the serotonin transporter (SERT), and to the vesicular monoamine transporter (VMAT2). 5‐HT, SERT, and VMAT2 labeled the raphe neurons and their terminal network from embryonic day (E)70 to adulthood. In addition, from E70–130 VMAT2 and SERT were observed in all the sensory cranial nerves, the olfactory nerve, the gustatory, the trigeminal, the auditory fibers, in the retinal ganglion cells, and the optic tract up to the lateral geniculate nucleus and the superior colliculus. All the spinal sensory ganglia and their peripheral sensory branches were labeled. Accumulation of 5‐HT was observed in all the sensory neurons expressing SERT and the corresponding axon tracts. Since these neurons were missing tryptophan hydroxylase (TPH), the synthesizing enzyme for 5‐HT, they most likely accumulated 5‐HT through the action of the amine transporters, as has been shown in rodents. No transient expression of 5‐HT markers was detectable in the sensory thalamocortical axons at any of the ages examined. Thus, the existence of 5‐HT uptake in nonserotoninergic neurons appears to be a conserved feature in primates, although the topographic extent of this transient expression is more restricted than that previously demonstrated in rodents. J. Comp. Neurol. 499:677–689, 2006. © 2006 Wiley‐Liss, Inc.
Cautions on the overgeneralized application of the NICE and CREST recommendations for the treatment of PTSD in the UK: a reflection from practice in Belfast, Northern Ireland
Authors: Dorahy Martin J.
Published: October 2006

The task of this paper is to present a message of caution regarding the overgeneralized reliance on the NICE (2005) and CREST (2003) recommendations for the treatment of post‐traumatic stress disorder (PTSD) in adults in the United Kingdom. The socio‐political and ethnocultural context of Northern Ireland is used as a foundation to explore the generalizibility of guideline recommendations. It is argued that clinicians should be mindful of the degree to which they generalize from the recommendations of these guidelines to their clinical work because (1) questions regarding the heterogeneity of PTSD raise as yet unaddressed empirical questions about the generalizability of treatments to all PTSD presentations and (2) ethnocultural and socio‐political factors have not yet played a dominant role in randomized outcome studies of treatment efficacy. Copyright © 2006 John Wiley & Sons, Ltd.
Mes2, a MADF‐containing transcription factor essential for Drosophila development
Authors: Zimmermann Gregor , Furlong Eileen E. , Suyama Kaye , Scott Matthew P.
Published: October 2006

The development of the Drosophila mesoderm is initiated by the basic helix‐loop‐helix transcription factor twist. We identified a gene encoding a putative transcription factor, mes2, in a screen for essential mesoderm‐expressed genes that function downstream of twist. Mes2 protein belongs to a family of 48 Drosophila proteins containing MADF domains. MADF domains exist in worms, flies, and fish. Mes2 is a nuclear protein first produced in trunk and head mesoderm during late gastrulation. At later embryonic stages, mes2 is expressed in glia of the central and peripheral nervous systems, and in tissues derived from the head mesoderm. We have identified a null mutation of mes2 that leads to developmental arrest in first instar larvae. Increased production of Mes2 in multiple embryonic and larval tissues almost always causes lethality. The ubiquitous or epidermal misexpression of mes2 in the embryo causes a dramatic loss of epidermal integrity resulting in the failure of dorsal closure. Our data show that the precise regulation of mes2 expression is critical for normal development in Drosophila and implicate Mes2 in the regulation of essential target genes. Developmental Dynamics 235:3387–3395, 2006. © 2006 Wiley‐Liss, Inc.
Neural stem cells for the treatment of disorders of the enteric nervous system: Strategies and challenges
Authors: Micci Maria‐Adelaide , Pasricha Pankaj Jay
Published: October 2006

The main goal of this review is to summarize the status of the research in the field of stem cells transplantation, as it is applicable to the treatment of gastrointestinal motility. This field of research has advanced tremendously in the past 10 years, and recent data produced in our laboratories as well as others is contributing to the excitement on the use of neural stem cells (NSC) as a valuable therapeutic approach for disorders of the enteric nervous system characterized by a loss of critical neuronal subpopulations. There are several sources of NSC, and here we describe therapeutic strategies for NSC transplantation in the gut. These include using NSC as a relatively nonspecific cellular replacement strategy in conditions where large populations of neurons or their subsets are missing or destroyed. As with many other recent “breakthroughs” stem cell therapy may eventually prove to be overrated. However, at the present time, it does appear to provide the hope for a true cure for many currently intractable diseases of both the central and the peripheral nervous system. Certainly more extensive research is needed in this field. We hope that our review will encourage new investigators in entering this field of research ad contribute to our knowledge of the potentials of NSC and other cells for the treatment of gastrointestinal dysmotility. Developmental Dynamics 236:33–43, 2007. © 2006 Wiley‐Liss, Inc.
ColVa1 and ColXIa1 are required for myocardial morphogenesis and heart valve development
Authors: Lincoln Joy , Florer Jane B. , Deutsch Gail H. , Wenstrup Richard J. , Yutzey Katherine E.
Published: October 2006

Genetic mutations in minor fibrillar collagen types Va1 (ColVa1) and XIa1 (ColXI) have been identified in connective tissue disorders including Ehlers–Danlos syndrome and chondrodysplasias. ColVa1+/− and ColXIa1−/− mutant mice recapitulate these human disorders and show aberrations in collagen fiber organization in connective tissue of the skin, cornea, cartilage, and tendon. In the heart, fibrous networks of collagen fibers form throughout the ventricular myocardium and heart valves, and alterations in collagen fiber homeostasis are apparent in many forms of cardiac disease associated with myocardial dysfunction and valvular insufficiency. There is increasing evidence for cardiac dysfunction in connective tissue disorders, but the mechanisms have not been addressed. ColVa1+/− and ColXIa1−/− mutant mice were used to identify roles for ColVa1 and ColXIa1 in ventricular myocardial morphogenesis and heart valve development. These affected cardiac structures show a compensatory increase in type I collagen deposition, similar to that previously described in valvular and cardiomyopathic disease. Morphological cardiac defects associated with changes in collagen fiber homeostasis identified in ColVa1+/− and ColXIa1−/− mice provide an insight into previously unappreciated forms of cardiac dysfunction associated with connective tissue disorders. Developmental Dynamics 235:3295–3305, 2006. © 2006 Wiley‐Liss, Inc.
The emerging market crisis and stock market linkages: further evidence
Authors: Yang Jian , Hsiao Cheng , Li Qi , Wang Zijun
Published: October 2006

This study examines the long‐run price relationship and the dynamic price transmission among the USA, Germany, and four major Eastern European emerging stock markets, with particular attention to the impact of the 1998 Russian financial crisis. The results show that both the long‐run price relationship and the dynamic price transmission were strengthened among these markets after the crisis. The influence of Germany became noticeable on all the Eastern European markets only after the crisis but not before the crisis. We also conduct a rolling generalized VAR analysis to confirm the robustness of the main findings. Copyright © 2006 John Wiley & Sons, Ltd.
Stability, limb coordination and substrate type: the ecorelevance of gait sequence pattern in primates
Authors: Stevens Nancy Jeanne
Published: October 2006

The coordination of limb movements during mammalian locomotion has been well documented in the literature. Most mammals use lateral sequence (LS) gaits, in which a forelimb follows an ipsilateral hind limb during the stride cycle. Primates, however, tend to utilize diagonal sequence (DS) gaits, whereby a contralateral forelimb follows a given hind limb during the stride cycle. A number of scenarios have been offered to explain why primates favor DS gaits, most of them relating to the use of the arboreal habitat and, in particular, the exploitation of a terminal branch niche. Yet to date, there is surprisingly little evidence to support the advantage of DS gaits for negotiating different aspects of the terminal branch environment. Nonetheless, it is apparent that primates possess unique morphologies and a higher than typically recognized degree of flexibility in gait sequence pattern, both of which likely offer advantages for moving upon discontinuous and unstable terminal branches. This paper reviews potential explanations for the use of DS gaits in primates and considers mechanisms by which gait sequence may be altered during different types of arboreal challenges. J. Exp. Zool. 305A, 2006. © 2006 Wiley‐Liss, Inc.
Jessen–Wintner type random variables and fractal properties of their distributions
Authors: Albeverio Sergio , Gontcharenko Yana , Pratsiovytyi Mykola , Torbin Grygoriy
Published: October 2006

Formulas are given for the Lebesgue measure and the Hausdorff–Besicovitch dimension of the minimal closed set Sξ supporting the distribution of the random variable ξ = $ \sum ^\infty _{k=1} $ 2–k τk, where τk are independent random variables taking the values 0, 1, 2 with probabilities p 0k , p 1k , p 2k , respectively. A classification of the distributions of the r.v. ξ via the metric‐topological properties of Sξ is given. Necessary and sufficient conditions for superfractality and anomalous fractality of Sξ are found. It is also proven that for any real number a 0 ∈ [0, 1] there exists a distribution of the r.v. ξ such that the Hausdorff–Besicovitch dimension of Sξ is equal to a 0. The results are applied to the study of the metric‐topological properties of the convolutions of random variables with independent binary digits, i.e., random variables ξi = $ \sum ^\infty _{k=1} \, 2^{-k} \eta^i_k $, where ηk are independent random variables taking the values 0 and 1. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Infima of universal energy functionals on homotopy classes
Authors: Bechtluft‐Sachs Stefan
Published: October 2006

We consider the infima $ \hat E $(f) on homotopy classes of energy functionals E defined on smooth maps f: Mn → Vk between compact connected Riemannian manifolds. If M contains a sub‐manifold L of codimension greater than the degree of E then $ \hat E $(f) is determined by the homotopy class of the restriction of f to M \ L. Conversely if the infimum on a homotopy class of a functional of at least conformal degree vanishes then the map is trivial in homology of high degrees. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The relation between CDw (X)‐space and Whyburn unified space
Authors: Ercan Z. , Önal S.
Published: October 2006

We show that a CDw (X)‐space is isometrically Riesz isomorphic to C (W) for some Whyburn unified space W with its concrete description. We apply this to prove a Banach–Stone type theorem. This generalizes one of the main result in [2]. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generalized Hankel operators and the generalized solution operator to $ \bar \partial $ on the Fock space and on the Bergman space of the unit disc
Authors: Knirsch Wolfgang , Schneider Georg
Published: October 2006

In this paper we consider Hankel operators $ \tilde H _{{\bar z}^k}$ = (Id – P 1)$ \bar z^k $ from A 2(ℂ, |z |2) to A 2,1(ℂ, |z |2)⊥. Here A 2(ℂ, |z |2) denotes the Fock space

A 2(ℂ, |z |2) = {f: f is entire and ‖f ‖2 = ∫ℂ |f (z)|2 exp (–|z |2) dλ (z) < ∞}.

Furthermore A 2,1(ℂ, |z |2) denotes the closure of the linear span of the monomials {$ \bar z ^l $z n : n, l ∈ ℕ, l ≤ 1} and the corresponding orthogonal projection is denoted by P 1. Note that we call these operators generalized Hankel operators because the projection P 1 is not the usual Bergman projection. In the introduction we give a motivation for replacing the Bergman projection by P 1. The paper analyzes boundedness and compactness of the mentioned operators.

On the Fock space we show that $ \tilde H _{{\bar z}^2}$ is bounded, but not compact, and for k ≥ 3 that $ \tilde H _{{\bar z}^k}$ is not bounded. Afterwards we also consider the same situation on the Bergman space of the unit disc. Here a completely different situation appears: we have compactness for all k ≥ 1.

Finally we will also consider an analogous situation in the case of several complex variables. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Asymptotic analysis of solutions of a radial Schrödinger equation with oscillating potential
Authors: Bodine Sigrun , Lutz D. A.
Published: October 2006

We are interested in the asymptotic behavior of solutions of a Schrödinger‐type equation with oscillating potential which was studied by A. Its. Here we use a different technique, based on Levinson's Fundamental Lemma, to analyze the asymptotic behavior, and our approach leads to a complete asymptotic representation of the solutions. We also discuss formal simplifications for differential equations with what might be called “regular/irregular singular points with periodic coefficients”. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Neurosurgical treatment of tremor in mitochondrial encephalopathy
Authors: Kovacs Norbert , Pal Endre , Balas Istvan , Janszky Jozsef , Nagy Ferenc , Merkli Hajnalka
Published: October 2006

A 53‐year‐old woman underwent several ischemic stroke‐like episodes and later developed incomplete, bilateral ophthalmoplegia, left vision deterioration, and bilateral tremor. The clinical course, laboratory data, and muscle histology led to a diagnosis of mitochondrial encephalomyopathy. No other etiology could be identified in the background of her disabling bilateral postural–kinetic tremor. As this tremor did not respond to pharmacological therapy, left thalamotomy and subsequently right thalamic deep brain stimulator (DBS) implantation were performed, which resulted in an excellent clinical outcome. The Fahn–Tolosa–Marin Tremor Rating Scale improved from 110 to 11 points. This case suggests that the rare tremor caused by mitochondrial encephalopathy may be treated long‐term with either thalamotomy or thalamic DBS implantation. © 2006 Movement Disorder Society
Real‐time rigid body motion correction and shimming using cloverleaf navigators
Authors: van der Kouwe André J.W. , Benner Thomas , Dale Anders M.
Published: October 2006

Subject motion during scanning can greatly reduce MRI image quality and is a major reason for discarding data in both clinical and research scanning. The quality of the high‐resolution structural data used for morphometric analysis is especially compromised by subject movement because high‐resolution scans are of longer duration. A method is presented that measures and corrects rigid body motion and associated first‐order shim changes in real time, using a pulse sequence with embedded cloverleaf navigators and a feedback control mechanism. The procedure requires a 12‐s preliminary mapping scan. A single‐path, 4.2‐ms cloverleaf navigator is inserted every repetition time (TR) after the readout of a 3D fast low‐angle shot (FLASH) sequence, requiring no additional RF pulses and minimally impacting scan duration. Every TR, a rigid body motion estimate is made and a correction is fed back to adjust the gradients and shim offsets. Images are corrected and reconstructed on the scanner computer for immediate access. Correction for between‐scan motion can be accomplished by using the same reference map for each scan repetition. Human and phantom tests demonstrated a consistent improvement in image quality if motion occurred during the acquisition. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.