bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Microbial Fatty Acid Analysis for Quantifying Mixed Culture Biomass During Batch Growth
Authors: Werker Alan G. , Hall Eric R.
Published: October 2006

This paper considers microbial fatty acid (MFA) as a parameter for monitoring kinetics of changing biomass levels in dynamic environmental systems. Although there is no question that MFA and biomass levels are directly linked, the research literature suggests that the proportionality constant is variable. Thus, controlled batch cultivation experiments were performed to test the hypothesis that total MFA (TMFA) is a consistent biomass representation. The hypothesis was tested with measurement comparisons to the more conventional biomass parameters of dry weight and protein production. Experimental results supported the validity of TMFA analysis as a measurement method for assessing biomass growth kinetics under dynamic mixed culture conditions. Although MFA composition did change over the course of batch cultivation, TMFA remained directly proportional to biomass dry weight and protein production. In a comparison of absolute TMFA levels derived from two distinct protocols of MFA extraction, significant differences in the TMFA yield were observed. Therefore, MFA data need to be clearly referenced to the applied method of analysis.
Aerobic Biodegradation of Nitroglycerin in a Sequencing Batch Reactor
Authors: Accashian J.V. , Smets Barth F. , Kim Byung‐Joon
Published: October 2006

Biological treatment of nitroglycerin (glycerol trinitrate [GTN]) by a mixed microbial culture was examined under aerobic conditions in a bench‐scale sequencing batch reactor with GTN present as a minor component in the feed. Initial operation demonstrated the resistance of GTN and glycerol dinitrates (GDNs) to microbial attack. The presence of GTN and GDNs adversely affected microbial activity, reflected by erratic mixed liquor suspended solids concentrations and low chemical oxygen demand removal efficiencies. Complete removal of GTN and GDNs was contingent on addition of a GTN‐adapted inoculum. Transient accumulation and subsequent removal of 1,2‐GDN, 1,3‐GDN, and nitrite were measured during individual reaction cycles. Complete mineralization of GTN was confirmed and GDN denitration was the rate limiting step governing GTN mineralization.
Kinetics of Chromium Reduction by Mixed Cultures During Growth Phase
Authors: Schmieman Eric A. , Yonge David R. , Petersen James N. , Rege Mahesh A. , Apel William A.
Published: October 2006

Hexavalent chromium reduction kinetic parameters were estimated for several mixed cultures using molasses as the carbon source and nitrate as the terminal electron acceptor. Mixed cultures were enriched from diverse environmental sources, and kinetic parameter comparisons are made between the consortia and a pure culture grown under the same conditions. A statistical analysis of the results indicated that some kinetic parameters exhibited significant differences, whereas others did not. It should be noted that those parameters with statistically significant differences were nonetheless numerically similar. Conservative values, therefore, could be assumed, or site‐specific data obtained, for those parameters to design in situ bioremediation of chromium‐contaminated sites.
Design Criteria and Required Chemistry for Removing Manganese in Acid Mine Drainage Using Subsurface Flow Wetlands
Authors: Sikora F.J. , Behrends L.L. , Brodie G.A. , Taylor H.N.
Published: October 2006

Manganese (Mn) is a difficult metal to remove in acid mine drainage because of high pH requirements for oxidation of Mn to form Mn oxide precipitates. However, Mn removal can be quickened in a gravel system providing a large surface area and high pH for Mn oxidation to occur with microbiological mediation. An experiment was designed with 12 gravel bed mesocosms that were 9.8 m3 × 6.7 m3 × 0.6 m3 to determine the best design criteria for optimizing Mn removal. Treatments consisted of two Mn loading rates (1.1 and 2.7 g/m2·d) and two gravel types (limestone and river gravel) and were replicated three times. Water flowed through the experimental wetlands for 734 days. Manganese removal was more effective in limestone than in river gravel. Manganese removal was not affected by water temperature ranging from 5 to 30 °C in either rock material. Manganese removal rates ranged from 100 to 600 m/a in the limestone wetlands and 10 to 60 m/a in the river gravel wetlands. Greater pH in limestone (approximately 6.9) compared with river gravel (approximately 5.5) favored Mn oxide precipitation. Greater pH, coupled with oxidation–reduction potential (redox) values greater than 430 mV in the limestone, resulted in water chemistry near conditions predicting manganite to be the dominant Mn phase. Ideal pH and redox conditions for Mn removal are pH from 6.8 to 7.2 and redox greater than 500 mV. The range of dissolved oxygen (DO) required to remove Mn in the various wetlands ranged from 3 to 5 mg/L, with approximately one‐half of the DO loss caused by Mn hydroxide formation and one‐half ascribed to biological consumption. The influent DO should be at least 0.35 mg/L for every 1 mg/L Mn removed. Removal rates for Mn ranged from 1 to 17 g/m2·d in limestone and from 1 to 2 g/m2·d in river gravel. Limestone is the material of choice for subsurface flow wetlands for Mn removal. Removal rates and required chemistry determined in this study can be used to design subsurface flow wetlands for optimum Mn removal.
Real‐Time Monitoring and Control of Sequencing Batch Reactors for Secondary Treatment of a Poultry Processing Wastewater
Authors: Pierson John A. , Pavlostathis Spyros G.
Published: October 2006

Two sequencing batch reactors were operated to evaluate their efficiency for the pretreatment of a poultry processing wastewater. Although the primary goal was to evaluate the removal efficiency for oxidizable carbon as required by the National Pollutant Discharge Elimination System, this study also examined the relationship between the removal of nitrogen species and the reactor oxidation–reduction potential (ORP). On‐site, pilot‐scale units treated a postprimary treatment side stream, with 4‐hour processing cycles, four cycles per day, with no treatment on weekends. State‐of‐the‐art instrumentation for real‐time pH, ORP, and dissolved oxygen (DO) monitoring and process control based on ORP set points were used. Consistent effluent quality was achieved while treating a variable composition wastewater. By using ORP set points to control the duration of aeration, thus minimizing air blower operation time, removal efficiencies of greater than 93 and 35% were achieved for oxygen demand and ammonia, respectively. Characteristic features of the ORP profiles depicted the transition to low DO levels (≪ 1.0 mg/L). In addition, pH monitoring enhanced the usefulness of ORP readings as the means of identifying the onset of anoxic conditions and the dynamics of the nitrogen transformation processes.
Infiltration of Combined Sewer Overflow and Tertiary Treated Municipal Wastewater: An Integrated Laboratory and Field Study on Various Metals
Authors: Reemtsma Thorsten , Gnirss Regina , Jekel Martin
Published: October 2006

The heavy metal load of combined sewer overflow (CSO) and its retention during CSO infiltration was studied in a comparative field and laboratory experiment during a 2‐year period, with simultaneous study of tertiary treated municipal wastewater (TMW). The concentrations of aluminum, chromium, copper, iron, manganese, and zinc in CSO significantly exceeded those of TMW by factors ranging from 2 (manganese) to 12 (aluminum). Correlation analysis suggests that aluminum, barium, iron, lead, and zinc originate from urban runoff, while chromium and most alkali and alkaline earth elements are likely provided by municipal wastewater. As copper correlates with boron and zinc, raw wastewater and surface runoff may contribute to the elevated copper concentration in CSO. Laboratory column and field data indicate that analyzed metals were well retained during soil passage under the oxidizing conditions and that groundwater quality under CSO infiltration is comparable to TMW infiltration. Laboratory experiments show that nitrification and mineralization produce more acidity than CSO can neutralize. Thus, co‐infiltration of TMW with CSO or the addition of carbonate minerals to the soil is recommended to prevent soil acidification and maintain its retention potential.
Specificity of Microbial Activities in the Reductive Dechlorination of Chlorinated Benzenes
Authors: Chen I‐Ming , Chang Fang‐Cheng , Chang Bea‐Ven , Wang Yei‐Shung
Published: October 2006

Anaerobic mixed cultures collected from tropical sediment were found to possess the ability to dechlorinate pentachlorobenzene (QCB) and hexachlorobenzene (HCB) after a long‐term acclimation in HCB. The primary product for HCB and QCB was 1,3,5‐trichlorobenzene (1,3,5‐TCB). During QCB dechlorination, 1,2,3,5‐tetrachlorobenzene (1,2,3,5‐TeCB) is accumulated as the intermediate, but during the HCB dechlorination, QCB and 1,2,3,5‐TeCB are not found. When treated with chloramphenicol, the microorganisms precultured in HCB were found to dechlorinate HCB for only 1 day and dechlorinate QCB for several days. However, microorganisms precultured in QCB could not dechlorinate HCB at all. Results also indicate that HCB is not directly dechlorinated to 1,3,5‐TCB by a single microbial activity but that various microbial systems are responsible for each step of dechlorination from HCB to 1,3,5‐TCB.
Specific Determination of Inorganic Monochloramine in Chlorinated Wastewaters
Authors: Harp Danial L.
Published: October 2006

The two conventional methods for wastewater chloramination control, residual maintenance and oxidation–reduction potential control, are not specific for the desired disinfectant, monochloramine. Organochloramines, nitrite, manganese, and chromate positively interfere with classical residual control measurements. Oxidation–reduction potential control may not be able to distinguish between monochloramine and weaker disinfecting organochloramines typically found in chlorinated domestic wastewaters. A new method of control is presented that is shown to be specific for the inorganic monochloramine species. The new method is based on a modification of the classical Berthelot analysis method for ammonia. Improvements to the method have greatly increased its selectivity toward monochloramine in chlorinated wastewater matrices. Breakpoint chlorination profiles of various chlorinated wastewaters demonstrate that the conventional control methods could potentially overestimate germicidal efficiency, especially near the breakpoint area. The new method has demonstrated good specificity for monochloramine in the samples studied and has been adapted for automated chlorine control in wastewater.
Ammonia and Toxicity Criteria in Polluted Onondaga Lake, New York
Authors: Matthews David A. , Effler Steven W. , Matthews Carol M.
Published: October 2006

Temporal patterns of total ammonia (T‐NH3) in the upper layers of an ammonia‐polluted, saline, hypereutrophic urban lake, Onondaga Lake, New York, and its status with respect to ammonia toxicity criteria are documented and evaluated for the spring to fall interval over 10 years (1989 to 1998). Implications of revisions (n = 5) in the criteria (1985 to 1999) and the omission of ionic strength effects in the most recent revisions for this saline system are considered. The implications of diurnal variations in pH for application of both chronic and acute criteria are illustrated based on 14 days of hourly pH data. Concentrations of T‐NH3 in the upper layers of this lake were extremely high because of discharges received from a 3.5 m3/s (80 mgd) wastewater treatment plant; the average concentration during the April to June interval for the 10 years was 2.3 mg/L. Substantial interannual and seasonal variations were observed in the T‐NH3 pool of the lake. April concentrations were largely regulated by the dilution provided by antecedent (i.e., December to March) tributary flow. Revisions of the chronic criteria have been progressively less stringent for low ionic strength conditions. However, under the saline conditions of this lake, the most recent (1998 and 1999) revisions can be more stringent than the earlier criteria. The 1984 chronic criterion (published in 1985) was exceeded by a wide margin annually (average factor of 2.2 for April to June) and for durations greater than 75 days. Widely different diurnal patterns in pH and the occurrence of an exceedance of the 1998 acute criterion during a pH maximum are documented. These diurnal variations are an important factor in the design of programs to assess status and in application of criteria for productive systems.
Influence of Chitosan Characteristics and Environmental Conditions on Flocculation of Anaerobic Sludge
Authors: Kaseamchochoung Chudapak , Lertsutthiwong Pranee , Phalakornkule Chantaraporn
Published: October 2006

The effects of chitosan characteristics (i.e., degree of deacetylation [DD] and molecular weight) and environmental conditions (i.e., ionic strength and pH) on the flocculation of anaerobic sludge were investigated. The results showed that chitosan enhanced the flocculation of sludge, and the flocculation efficiency depended on both the degree of deacetylation and molecular weight. Chitosan with 85%DD was more effective than that with 70%DD, as the former required a lower dose to obtain 90% flocculation at all studied pH values. In addition, low molecular weight chitosan enhanced the flocculation better than high molecular weight chitosan. The increase in ionic strength (up to 0.1 M) of the suspension helped reduce restabilization that occurred when chitosan was overdosed. In general, chitosan has potential to be used as an effective cationic bioflocculant, which is able to function either in acidic or neutral conditions, and very small amounts of chitosan (less than 4 mg/g dried sludge) are required.
Water Vapor and Air Transport Through Ponds with Floating Aquatic Plants
Authors: Kirzhner F. , Zimmels Y.
Published: October 2006

The purpose of this paper is to estimate the evaporation rate in the purification of wastewater by aquatic plants with aeration. Evaporation of surface water is important in dewatering processes. In particular, this is true in arid climates, where evaporation rates are high. Aeration is known to enhance the wastewater purification process, but it increases concurrently the water evaporation rates. Evaporation and evapotranspiration rates were tested under field and laboratory conditions. Batch experiments were performed to study the levels of evaporation and evapotranspiration in free‐water‐surface, aquatic‐plant systems. The experiments verified that, in these systems, the rate of evaporation increased as a result of aeration in the presence and absence of the aquatic plants. The evaporation rates resulting from aeration were found to be significant in the water balance governing the purification process. A preliminary model for description of the effect of rising air bubbles on the transport of water vapors was formulated. It is shown that aeration may account for a significant part of water losses that include surface evaporation.
A Study for Evaluation of Contaminant Transport Characteristics Through Fine‐Grained Soil
Authors: Kumar Sunil , Mukherjee S. N. , Ghosh S. , Ray R.
Published: October 2006

Transport of soluble toxic substances through porous media lead to some significant geoenvironmental problems, for example, leachate migration from municipal and industrial solid waste resulting from unregulated disposal. Advection, dispersion, diffusion, and decay are reported to be the principal mechanisms in such phenomena. Geotechnical properties of the soil also play a significant role in this deterioration. In the present study, laboratory tests were conducted to formulate an appropriate method for assessment of migration of metal ions, such as nickel, through the soil. Relevant kinetic and process parameters, such as aquifer data, surface area, dielectric constant, pH of zero point charge (pHzpc), and permeability were also studied. One‐dimensional mathematical modeling was used to describe the dynamics of the process. The present investigation was carried out at an ash pond site of a thermal power plant situated in West Bengal, India.
Economic Implications of Fine‐Pore Diffuser Aging
Authors: Rosso Diego , Stenstrom Michael K.
Published: October 2006

Aerobic biological treatment, such as the activated sludge process, is commonly used for municipal wastewater treatment. Fine‐pore diffusers have virtually replaced coarse‐bubble diffusers in such operations, but most of the plant's energy expenditure is still consumed by aeration. Therefore, the performance of diffusers will critically affect plant economics. This paper analyzes and quantifies the consequences of aging processes on fine‐pore diffusers. Datasets from 94 field measurements were analyzed and showed a clear pattern of performance decline with time in operation. Efficiency declines rapidly during the first 24 months of operation when the rate of decline decreases and efficiency stabilizes at a low value. For example, cost analysis scenarios were performed using the measured rate of decline in diffuser performance. The analyses include loss of transfer efficiency and elevated headloss, which both increase operating cost. Cleaning the diffusers within 12 months of operation is generally economically favorable, restores efficiency, and reduces power overhead. Periodic cleaning prolongs the economically viable lifespan for the aeration system.
Hydrothermal Oxidation of Waste Lipids, Protein, and Starch from New Zealand Meat‐ and Vegetable‐Processing Plants
Authors: Richardson Michael J. , Johnston James H. , Northcote Peter T.
Published: October 2006

Disposal of organic waste materials from the meat‐ and vegetable‐processing industries historically has been undertaken by dumping, drying followed by combustion, or biological oxidation. As a result of higher intensity processing rates and increasingly stringent legislation, these are no longer economical. Hydrothermal oxidation, also referred to as “wet” oxidation, has been used to lower the chemical and biological oxygen demand of waste samples from the above two industries. The starch‐based wastes were readily oxidized without a catalyst. For the lipid and protein‐based wastes, the use of copper calcium silicate and nitrate catalysts provided a significant reduction in oxygen demand at 230°C.
Studies of dehydration kinetics of Li2SO4·H2O by the master plots method
Authors: Wanjun Tang , Donghua Chen
Published: October 2006

The kinetics of Li2SO4·H2O dehydration in static air atmosphere was studied on the basis of nonisothermal measurements by differential scanning calorimetry. Dehydration data were subjected to an integral composite procedure, which includes an isoconversional method, a master plots method and a model-fitting method. Avrami-Erofeev equation was found to describe all the experimental data in the range of conversion degrees from 0.1 to 0.9. The determined activation energy equals 65.45 kJ·mol−1 with standard deviation ±0.47 kJ·mol−1. The estimated value of parameter m in Avrami-Erofeev equation is 2.15 with standard deviation ±0.11. Also, the obtained pre-exponential factor is 7.79×105 s−1 with standard deviation ±0.55×105 s−1. The results show that the present integral composite procedure gives self-consistent kinetic parameters.
Employment class arbitration: An oxymoron? Or a matter of contract?
Authors: Waks Jay W. , Poorten William
Published: October 2006

To what extent will courts send employment arbitration cases for class or collective actions? According to Jay W. Waks and William Poorten, of New York, waiving class action arbitrations doesn't impair claimants' substantive rights, and contractual silence means no class actions. The authors analyze the latest case law supporting their positions.
Protein Glycosylation, Conserved from Yeast to Man: A Model Organism Helps Elucidate Congenital Human Diseases
Authors: Lehle Ludwig , Strahl Sabine , Tanner Widmar
Published: October 2006

Proteins can be modified by a large variety of covalently linked saccharides. The present review concentrates on two types, protein N‐glycosylation and protein O‐mannosylation, which, with only a few exceptions, are evolutionary conserved from yeast to man. They are also distinguished by some special features: The corresponding glycosylation processes start in the endoplasmatic reticulum, are continued in the Golgi apparatus, and require dolichol‐activated precursors for the initial biosynthetic steps. With respect to the molecular biology of both types of protein glycosylation, the pathways and the genetic background of the reactions have most successfully been studied with the genetically easy‐to‐handle baker's yeast, Saccharomyces cerevisae. Many of the severe developmental disturbances in children are related to protein glycosylation, for example, the CDG syndrome (congenital disorders of glycosylation) as well as congenital muscular dystrophies with neuronal‐cell‐migration defects have been elucidated with the help of yeast.
An examination of searcher's perceptions of nonsponsored and sponsored links during ecommerce Web searching
Authors: Jansen Bernard J. , Resnick Marc
Published: October 2006

In this article, we report results of an investigation into the effect of sponsored links on ecommerce information seeking on the Web. In this research, 56 participants each engaged in six ecommerce Web searching tasks. We extracted these tasks from the transaction log of a Web search engine, so they represent actual ecommerce searching information needs. Using 60 organic and 30 sponsored Web links, the quality of the Web search engine results was controlled by switching nonsponsored and sponsored links on half of the tasks for each participant. This allowed for investigating the bias toward sponsored links while controlling for quality of content. The study also investigated the relationship between searching self‐efficacy, searching experience, types of ecommerce information needs, and the order of links on the viewing of sponsored links. Data included 2,453 interactions with links from result pages and 961 utterances evaluating these links. The results of the study indicate that there is a strong preference for nonsponsored links, with searchers viewing these results first more than 82% of the time. Searching self‐efficacy and experience does not increase the likelihood of viewing sponsored links, and the order of the result listing does not appear to affect searcher evaluation of sponsored links. The implications for sponsored links as a long‐term business model are discussed.
The M3/M4 cytoplasmic loop of the α1 subunit restricts GABAARs lateral mobility: A study using fluorescence recovery after photobleaching
Authors: Perán Macarena , Hooper Helen , Boulaiz Houria , Marchal Juan A. , Aránega Antonia , Salas Ramiro
Published: October 2006

A crucial problem in neurobiology is how neurons are able to maintain neurotransmitter receptors at specific membrane domains. The large structural heterogeneity of gamma aminobutyric acid receptors (GABAARs) led to the hypothesis that there could be a link between GABAAR gene diversity and the targeting properties of the receptor complex. Previous studies using Fluorescence Recovery After Photobleaching (FRAP) have shown a restricted mobility in GABAARs containing the α1 subunit. The M3/M4 cytoplasmic loop is the region of the α1 subunit with the lowest sequence homology to other subunits. Therefore, we asked whether the M3/M4 loop is involved in cytoskeletal anchoring and GABAAR clustering. A series of α1 chimeric subunits was constructed: α1CH (control subunit), α1CD (Cytoplasmic loop deleted), α1CD2, and α1CD3 (α1 with the M3/M4 loop from the α2 and α3 subunits, respectively). Our results using FRAP indicate an involvement of the M3/M4 cytoplasmic loop of the α1 subunit in controlling receptor lateral mobility. On the other hand, inmunocytochemical approaches showed that this domain is not involved in subunit targeting to the cell surface, subunit‐subunit assembly, or receptor aggregation. Cell Motil. Cytoskeleton 2006. © 2006 Wiley‐Liss, Inc.
Cost savings associated with the use of fine‐needle aspiration biopsy (FNAB) for the diagnosis of palpable masses in a community hospital‐based FNAB clinic
Authors: Florentine Barbara D. , Staymates Barry , Rabadi Munif , Sarda Nayibe , Barstis John , Black Alexander
Published: October 2006

BACKGROUND.

Generally, it is assumed that fine‐needle aspiration biopsy (FNAB) for the diagnosis of superficial, palpable masses is a less expensive alternative to diagnostic open surgical biopsy; however, to the authors' knowledge few studies to date have sought to quantify the number of diagnostic surgical procedures avoided and cost savings involved. In this article, the authors report their experience with 664 FNAB procedures that were performed by a cytopathologist/cytotechnologist team practicing in a community setting.

METHODS.

Records from a total of 664 consecutive FNAB cases from 607 patients who underwent FNAB in a community hospital‐based FNAB clinic between 2003 and 2005 were reviewed retrospectively, and follow‐up data were obtained.

RESULTS.

Surgery was averted entirely as a result of the FNAB in 83% or 505 of 609 cases with follow‐up available. The FNAB procedure was highly accurate and considerably less expensive than surgical biopsy.

CONCLUSION.

For patients who presented with palpable masses, FNAB was a reliable, cost‐effective initial method for obtaining a tissue diagnosis. Cancer 2006. © 2006 American Cancer Society.
Improved tolerability and quality of life with maintained efficacy using twice‐daily low‐dose interferon‐α‐2b
Authors: Tannir Nizar M. , Cohen Lorenzo , Wang Xuemei , Thall Peter , Mathew Paul F. , Jonasch Eric , Siefker‐Radtke Arlene , Pagliaro Lance C. , Ng Chaan S. , Logothetis Christopher
Published: October 2006

BACKGROUND.

In vivo data have shown a more potent antiangiogenic effect and a higher antitumor activity of low‐dose interferon (IFN) given twice daily. In a randomized Phase II trial, the authors tested the hypothesis that twice‐daily low‐dose IFN is more effective than daily intermediate‐dose IFN in patients with metastatic renal cell cancer (MRCC).

METHODS.

A total of 118 patients (59 per arm) were randomly assigned to receive IFN at a dose of 0.5 million units (MU) given subcutaneously twice daily (IFN1) or IFN at a dose of 5 MU given subcutaneously daily (IFN5). The primary endpoint was progression‐free survival (PFS). Secondary endpoints included response rate (RR), overall survival (OS), toxicity, and quality of life (QOL).

RESULTS.

There were no significant differences in either PFS or OS between IFN1 and IFN5 (median of 3.7 months and median of 3.4 months PFS, respectively; median of 25.5 months and median of 17.5 months OS, respectively). The RRs were identical in the 2 arms (6.7%; 95% confidence interval [95% CI], 1.8–16.5%). Two patients, 1 in each arm, remained in complete remission at the time of last follow‐up, at 45+ and 38+ months from treatment. Thirty‐two patients receiving IFN5 and 19 patients receiving IFN1 experienced Grade 3 or higher adverse events (graded using the National Cancer Institute Common Toxicity Criteria [version 2.0]) (P= .025). Eighteen patients receiving IFN5 and 4 patients receiving IFN1 had dose reductions (P= .002). There was a significant deterioration in QOL and an increase in depression associated with IFN5 but no change was noted with IFN1.

CONCLUSIONS.

Compared with IFN5, IFN1 is neither more nor less effective but is less toxic, with a better reported QOL. These results may have implications for the design of combination regimens incorporating IFN with targeted agents. Cancer 2006. © 2006 American Cancer Society.
Gα encoding gene family of the malaria vector mosquito Anopheles gambiae: Expression analysis and immunolocalization of AGαq and AGαo in female antennae
Authors: Rützler Michael , Lu Tan , Zwiebel Laurence J.
Published: October 2006

To initiate a comprehensive investigation of chemosensory signal transduction downstream of odorant receptors, we identified and characterized the complete set of genes that encode G‐protein α subunits in the genome of the malaria vector mosquito An. gambiae. Data are provided on the tissue‐specific expression patterns of 10 corresponding aga‐transcripts in adult mosquitoes and pre‐imago developmental stages. Specific immunoreactivity in chemosensory hairs of female antennae provides evidence in support of the participation of a subset of AGαq isoforms in olfactory signal transduction in this mosquito. In contrast, AGαo is localized along the flagellar axon bundle but is absent from chemosensory sensilla, which suggests that this G‐protein α subunit does not participate in olfactory signal transduction. J. Comp. Neurol. 499:533–545, 2006. © 2006 Wiley‐Liss, Inc.
Primary and secondary sensory trigeminal projections in a cyprinid teleost, carp (Cyprinus carpio)
Authors: Xue Hao‐Gang , Yang Chun‐Ying , Ito Hironobu , Yamamoto Naoyuki , Ozawa Hitoshi
Published: October 2006

Primary and secondary sensory trigeminal projections were studied by means of tract‐tracing methods in a cyprinid teleost, the carp. Tracer injections into the trigeminal nerve root labeled terminals in the ipsilateral principal sensory trigeminal nucleus, descending trigeminal nucleus, medial funicular nucleus, facial lobe, and medial part of posterior lateral valvular nucleus. The principal sensory trigeminal nucleus is considered a major origin of the secondary sensory trigeminal projections in teleosts. To investigate the secondary sensory trigeminal projections, tracer injections were performed into the principal sensory trigeminal nucleus. The present study suggests that the principal sensory trigeminal nucleus projects to the bilateral ventromedial thalamic nucleus, periventricular pretectal nucleus, stratum album centrale of the optic tectum, caudomedial region of lateral preglomerular nucleus, ventrolateral nucleus of semicircular torus, medial part of rostral and posterior lateral valvular nucleus, oculomotor nucleus, trochlear nucleus, trigeminal motor nucleus, facial motor nucleus, superior and inferior reticular formation, descending trigeminal nucleus, medial funicular nucleus, inferior olive, and to the contralateral sensory trigeminal nucleus. These observations indicate that the primary and secondary trigeminal sensory projections of a cyprinid teleost, the carp, are similar to those in percomorph teleosts. J. Comp. Neurol. 499:626–644, 2006. © 2006 Wiley‐Liss, Inc.
Differential responses to branched and unsaturated aliphatic hydrocarbons in the rat olfactory system
Authors: Ho Sabrina L. , Johnson Brett A. , Chen Andrew L. , Leon Michael
Published: October 2006

In an effort to understand mammalian olfactory processing, we have been describing the responses to systematically different odorants in the glomerular layer of the main olfactory bulb of rats. Previously, we demonstrated chemotopically organized and distinct olfactory responses to a homologous series of straight‐chained alkanes that consisted of purely hydrocarbon structures, indicating that hydrocarbon chains could serve as molecular features in the combinatorial coding of odorant information. To better understand the processing of hydrocarbon odorants, we now have examined responses to other types of chemical changes in these kinds of molecules, namely, branching and carbon–carbon bond saturation. To this end, we used the [14C]2‐deoxyglucose method to determine glomerular responses to a group of eight‐carbon branched alkane isomers, unsaturated octenes (double‐bonded), and octynes (triple‐bonded). In contrast to the differential responses we observed previously for straight‐chained alkanes of differing carbon number, the rat olfactory system was not particularly sensitive to these variations in branching and bond saturation. This result was unexpected, given the distinct molecular conformations and property profiles of the odorants. The similarity in activity patterns was paralleled by a similarity in spontaneous perceptual responses measured using a habituation assay. These results demonstrate again the functional relationship between bulbar activity patterns and odor perception. The results further suggest that the olfactory system does not respond equally to all aspects of odorant chemistry, functioning as a specific, rather than a general, chemical analysis system. J. Comp. Neurol. 499:519–532, 2006. © 2006 Wiley‐Liss, Inc.
Role of endothelin‐1, sodium hydrogen exchanger‐1 and mitogen activated protein kinase (MAPK) activation in glucose‐induced cardiomyocyte hypertrophy
Authors: Chen Shali , Khan Zia A. , Karmazyn Morris , Chakrabarti Subrata
Published: October 2006

Background

Cardiac hypertrophy is a key structural feature of diabetic cardiomyopathy. Previous studies have shown that diabetes‐induced endothelin‐1 (ET‐1) and sodium hydrogen exchanger‐1 (NHE‐1) mediate structural and functional deficits in the heart. In order to gain a mechanistic understanding of the role of ET‐1 and NHE‐1 in cardiomyocyte hypertrophy, we have utilized an in vitro endothelial‐myocyte co‐culture system to reveal cellular interactions that may arbitrate cardiomyocyte deficits in diabetes.

Methods and Results

Rat ventricular cardiomyocytes were cultured in high glucose levels, which caused cellular hypertrophy. Hypertrophic markers, atrial natruritic peptide (ANP) and angiotensinogen (Agt), as well as inducible nitric oxide synthase (iNOS) were upregulated by high glucose. Treatment of cells with ET antagonist bosentan and NHE‐1 inhibitor cariporide prevented glucose‐induced cardiomyocyte hypertrophy and expression of ANP, Agt, and iNOS. Bosentan and cariporide treatment of cardiomyocytes co‐cultured with endothelial cells produced a more pronounced normalization of glucose‐induced changes as compared to cardiomyocyte cultured alone. To further explore the signaling mechanisms involved, we investigated the mitogen activated protein kinase (MAPK) pathway and its cross‐interaction with signaling proteins known to be altered in diabetes. Our results indicate that MAPK activation is associated with cardiomyocyte hypertrophy and is inhibited by bosentan, cariporide, as well as protein kinase C inhibiton. Furthermore, MAPK activation was found to be upstream of the transcription factors, nuclear factor‐κB and activating protein‐1.

Conclusion

These results demonstrate that ET‐1 and NHE‐1 may mediate cardiomyocyte hypertrophy via MAPK activation and provide an insight into the pathogenesis of diabetic cardiomyopathy. Copyright © 2006 John Wiley & Sons, Ltd.
Satellite cells express distinct patterns of myogenic proteins in immature skeletal muscle
Authors: Schultz Edward , Chamberlain Connie , McCormick Kathleen M. , Mozdziak Paul E.
Published: October 2006

Satellite cells are the myogenic cells lying between the myofiber sarcolemma and basal lamina. The objective of this study was to determine the expression patterns of MyoD, myogenin, and Pax7 within the satellite cell population in the growing rat soleus and extensor digitorum longus (EDL) muscles. Secondly, the expression of the myogenic markers was also studied within the interstitial cell compartment and myonuclei. It was discovered that the soleus contained a higher number of Pax7, MyoD, or myogenin‐positive nuclei compared with the EDL. Similarly, myogenin was expressed at a lower level in the myonuclei of the soleus compared with the EDL, and myogenin was expressed at a higher level in the interstitial compartment of the soleus compared with the EDL. When interstitial nuclei, myonuclei, and double‐labeled nuclei were used in the estimate of the satellite cell population, it was discovered that approximately of 13% of the myofibers in a transverse section of the soleus muscle and 4.1% of EDL myofibers exhibit a labeled satellite cell nucleus. Overall, results from this study suggest that expression patterns of these markers vary predictably among muscles with different growth dynamics and phenotypic characteristics. Developmental Dynamics 235:3230–3239, 2006. © 2006 Wiley‐Liss, Inc.
Enantiomeric separation of underivatized small amines in conventional and on‐chip capillary electrophoresis with contactless conductivity detection
Authors: Gong Xiao Yang , Hauser Peter C.
Published: October 2006

The determination of the enantiomers of small non‐UV‐absorbing amines which otherwise can only be achieved with difficulty was possible by using a combination of the chiral crown ether (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid (18C6H4) and dimethyl‐β‐CD as selectors in CE and contactless conductivity measurement for detection. Alkylamines without any other functional group, amino alcohols, species with ether or ester groups and with a cyclic moiety were investigated. The detection limits were found to be about 1.0 μM and the determination is possible up to at least 1.0 mM. The determination of enantiomeric ratios of up to 99.5:0.5 was also found feasible.
Dehydroepiandrosterone sulfate and estrone sulfate reduce GABA‐recurrent inhibition in the hippocampus via muscarinic acetylcholine receptors
Authors: Steffensen Scott C. , Jones Marc D. , Hales Kimberly , Allison David W.
Published: October 2006

Several recent studies have established a role for estrogens in ameliorating specific neurodegenerative disorders, mainly those associated with the cholinergic neurons of the basal forebrain and their targets in the cortex and hippocampus. We have previously demonstrated that endogenous and exogenous application of the neurosteroid dehydroepiandrosterone sulfate (DHEAS) markedly reduces GABA‐mediated recurrent inhibition and synchronizes hippocampal unit activity to theta rhythm (Steffensen (1995) Hippocampus 5:320–328). In this study, we evaluated the role of muscarinic receptors in mediating the effects of DHEAS and estrone sulfate (ES), the principal circulating estrogen in humans, on short‐latency‐evoked potential responses, paired‐pulse inhibition (PPI), paired‐pulse facilitation, and GABA interneuron activity in the dentate gyrus and CA1 subfields of the rat hippocampus. In situ microelectrophoretic application of the muscarinic M2 subtype cholinergic receptor agonist cis‐dioxolane, DHEAS, and ES markedly reduced PPI in the dentate and CA1 that was blocked by the M2 receptor antagonist gallamine. Similar to DHEAS, microelectrophoretic administration of ES increased population spike amplitudes, without increasing excitatory transmission, but this effect was not blocked by gallamine. Microelectrophoretic application of cis‐dioxolane and ES markedly increased the firing rate of dentate hilar interneurons and CA1 oriens/alveus interneurons and enhanced their synchrony to hippocampal theta rhythm. These findings suggest that select GABA‐modulating neurosteroids and neuroactive estrogen sulfates alter septohippocampal cholinergic modulation of hippocampal GABAergic interneurons mediating recurrent, but not feedforward, inhibition of hippocampal principal cell activity. © 2006 Wiley‐Liss, Inc.
London taxi drivers and bus drivers: A structural MRI and neuropsychological analysis
Authors: Maguire Eleanor A. , Woollett Katherine , Spiers Hugo J.
Published: October 2006

Licensed London taxi drivers show that humans have a remarkable capacity to acquire and use knowledge of a large complex city to navigate within it. Gray matter volume differences in the hippocampus relative to controls have been reported to accompany this expertise. While these gray matter differences could result from using and updating spatial representations, they might instead be influenced by factors such as self‐motion, driving experience, and stress. We examined the contribution of these factors by comparing London taxi drivers with London bus drivers, who were matched for driving experience and levels of stress, but differed in that they follow a constrained set of routes. We found that compared with bus drivers, taxi drivers had greater gray matter volume in mid‐posterior hippocampi and less volume in anterior hippocampi. Furthermore, years of navigation experience correlated with hippocampal gray matter volume only in taxi drivers, with right posterior gray matter volume increasing and anterior volume decreasing with more navigation experience. This suggests that spatial knowledge, and not stress, driving, or self‐motion, is associated with the pattern of hippocampal gray matter volume in taxi drivers. We then tested for functional differences between the groups and found that the ability to acquire new visuo‐spatial information was worse in taxi drivers than in bus drivers. We speculate that a complex spatial representation, which facilitates expert navigation and is associated with greater posterior hippocampal gray matter volume, might come at a cost to new spatial memories and gray matter volume in the anterior hippocampus. © 2006 Wiley‐Liss, Inc.
How do respondents process stated choice experiments? Attribute consideration under varying information load
Authors: Hensher David A.
Published: October 2006

The popularity of stated choice (SC) experiments has produced many design strategies in which researchers use increasingly more ‘complex’ choice settings to study choice behaviour. When the amount of information to assess increases, we wonder how an individual handles such information in making a choice. Defining the amount of information as the number of attributes associated with each choice set, we investigate how this information is processed as we vary its ‘complexity’. Four ordered heterogeneous logit models are developed, each for an SC design based on a fixed number of attributes, in which the dependent variable defines the number of attributes that are ignored. We find that the degree to which individuals ignore attributes is influenced by the dimensionality of the SC experiment, the deviation of attribute levels from an experienced reference alternative, the use of ‘adding up’ attributes where feasible, the number of choice sets evaluated, and the personal income of the respondent. The empirical evidence supports the view that individuals appear to adopt a range of ‘coping’ strategies that are consistent with how they process information in real markets, and that aligning ‘choice complexity’ with the amount of information to process is potentially misleading. Relevancy is what matters. Copyright © 2006 John Wiley & Sons, Ltd.
How quickly do forecasters incorporate news? Evidence from cross‐country surveys
Authors: Isiklar Gultekin , Lahiri Kajal , Loungani Prakash
Published: October 2006

Using forecasts from Consensus Economics Inc., we provide evidence on the efficiency of real GDP growth forecasts by testing whether forecast revisions are uncorrelated. As the forecast data used are multi‐dimensional—18 countries, 24 monthly forecasts for the current and the following year and 16 target years—the panel estimation takes into account the complex structure of the variance–covariance matrix due to propagation of shocks across countries and economic linkages among them. Efficiency is rejected for all 18 countries: forecast revisions show a high degree of serial correlation. We then develop a framework for characterizing the nature of the inefficiency in forecasts. For a smaller set of countries, the G‐7, we estimate a VAR model on forecast revisions. The degree of inefficiency, as manifested in the serial correlation of forecast revisions, tends to be smaller in forecasts of the USA than in forecasts for European countries. Our framework also shows that one of the sources of the inefficiency in a country's forecasts is resistance to utilizing foreign news. Thus the quality of forecasts for many of these countries can be significantly improved if forecasters pay more attention to news originating from outside their respective countries. This is particularly the case for Canadian and French forecasts, which would gain by paying greater attention than they do to news from the USA and Germany, respectively. Copyright © 2006 John Wiley & Sons, Ltd.
Mentoring special youth populations
Authors: Britner Preston A. , Balcazar Fabricio E. , Blechman Elaine A. , Blinn‐Pike Lynn , Larose Simon
Published: October 2006

Whereas mentoring programs are well received as support services, very little empirical research has been conducted to assess the effectiveness of these programs to meet the diverse needs of different special populations of youth. Potentially useful theoretical orientations (attachment, parental acceptance‐rejection, social support, adult development, host provocation) and a sociomotivational model of mentoring are presented to complement Rhodes's (2002) model. Mentoring research literatures for five special populations of youth (abused and neglected youth, youth who have disabilities, pregnant and parenting adolescents, juvenile offenders, academically at‐risk students) are critiqued. Systemic, longitudinal research must address the cooccurrence of risk factors, populations, and interventions. We conclude with specific recommendations for future research. © 2006 Wiley Periodicals, Inc.
Community organizing and advocacy: Increasing the quality and quantity of mentoring programs
Authors: Wandersman Abraham , Clary E. Gil , Forbush Janet , Weinberger Susan G. , Coyne Shawn M. , Duffy Jennifer L.
Published: October 2006

Although youth mentoring programs are widespread, it is clear that there is a great need to increase their quality and quantity. This article provides background on funding initiatives in mentoring, and the role of community organizing and advocacy in influencing the demand for programs. A model that examines the community's role in influencing and coordinating key stakeholder groups in planning, implementing, and sustaining programs is proposed. The need for more effective programs is examined in a second model, which relates the capacity of organizations, staff, and programs for training and technical assistance to the quality and efficacy of their programs. Recommendations for future research are made. © 2006 Wiley Periodicals, Inc.
Thermovoltaic properties of hornet silk
Authors: Volynchik S. , Plotkin M. , Ermakov N.Y. , Bergman D.J. , Ishay J.S.
Published: October 2006

In silk from the larval silk caps of the Oriental hornet Vespa orientalis (Hymenoptera, Vespinae), temperature‐dependent changes in the electric voltage have been recorded, with rise in the voltage occurring mainly upon rise in the temperature between 10–36°C. The peak voltage was measured between 32–38°C and attained 240–360 mV, but with further increase in temperature, the voltage decreased, dropping to 0 mV at about 45–50°C. Upon second measurement (of same silk specimen), the voltage peak usually occurred later (by 8–9°C) and at higher temperature than in the first measurement. Continuous measurements during warming up to 30°C followed by cooling down to 15°C yielded an hysteresis between the warming “line” and the cooling “line”, the former often straight and the latter usually curved. Maintaining the silk specimen at a fixed temperature for a prolonged period (hours) initially causes the voltage to rise, then remain steady, and finally drop. Boiling the silk caps in tap water for 7–10 min exerts some changes in the silk properties, mainly a decrease in voltage level. The general behavior of the silk suggests that it is a polymer endowed with the qualities of an organic semiconductor. The various properties of the larval silk are discussed in great detail. Microsc. Res. Tech., 2006. © 2006 Wiley‐Liss, Inc.