bluuebunny/crossref_metadata_2025 huggingface dataset:
Major Quantitative Trait Loci Affect Resistance to Infectious Pancreatic Necrosis in Atlantic Salmon (Salmo salar)
Authors: Houston Ross D , Haley Chris S , Hamilton Alastair , Guy Derrick R , Tinch Alan E , Taggart John B , McAndrew Brendan J , Bishop Stephen C
Published: February 2008

Infectious pancreatic necrosis (IPN) is a viral disease currently presenting a major problem in the production of Atlantic salmon (Salmon salar). IPN can cause significant mortality to salmon fry within freshwater hatcheries and to smolts following transfer to seawater, although challenged populations show clear genetic variation in resistance. To determine whether this genetic variation includes loci of major effect, a genomewide quantitative trait loci (QTL) scan was performed within 10 full-sib families that had received a natural seawater IPN challenge. To utilize the large difference between Atlantic salmon male and female recombination rates, a two-stage mapping strategy was employed. Initially, a sire-based QTL analysis was used to detect linkage groups with significant effects on IPN resistance, using two to three microsatellite markers per linkage group. A dam-based analysis with additional markers was then used to confirm and position any detected QTL. Two genomewide significant QTL and one suggestive QTL were detected in the genome scan. The most significant QTL was mapped to linkage group 21 and was significant at the genomewide level in both the sire and the dam-based analyses. The identified QTL can be applied in marker-assisted selection programs to improve the resistance of salmon to IPN and reduce disease-related mortality.
Interplay of Developmentally Regulated Gene Expression and Heterochromatic Silencing in Trans in Drosophila
Authors: Sage Brian T , Wu Michael D , Csink Amy K
Published: February 2008

The brownDominant (bwD) allele of Drosophila contains a heterochromatic block that causes the locus to interact with centric heterochromatin. This association silences bw+ in heterozygotes (trans-inactivation) and is dependent on nuclear organizational changes later in development, suggesting that trans-inactivation may not be possible until later in development. To study this, a P element containing an upstream activating sequence (UAS)–GFP reporter was inserted 5 kb from the bwD insertion site. Seven different GAL4 driver lines were used and GFP fluorescence was compared in the presence or the absence of bwD. We measured silencing in different tissues and stages of development and found variable silencing of GFP expression driven by the same driver. When UAS–GFP was not expressed until differentiation in the eye imaginal disc it was more easily trans-inactivated than when it was expressed earlier in undifferentiated cells. In contrast to some studies by other workers on silencing in cis, we did not find consistent correlation of silencing with level of expression or evidence of relaxation of silencing with terminal differentiation. We suggest that such contrasting results may be attributed to a potentially different role played by nuclear organization in cis and trans position-effect variegation.
The Molecular Basis of Host Adaptation in Cactophilic Drosophila: Molecular Evolution of a GlutathioneS-Transferase Gene (GstD1) inDrosophila mojavensis
Authors: Matzkin Luciano M
Published: February 2008

Drosophila mojavensis is a cactophilic fly endemic to the northwestern deserts of North America. This species includes four genetically isolated cactus host races each individually specializing on the necrotic tissues of a different cactus species. The necrosis of each cactus species provides the resident D. mojavensis populations with a distinct chemical environment. A previous investigation of the role of transcriptional variation in the adaptation of D. mojavensis to its hosts produced a set of candidate loci that are differentially expressed in response to host shifts, and among them was glutathione S-transferase D1 (GstD1). In both D. melanogaster and Anopheles gambiae, GstD1 has been implicated in the resistance of these species to the insecticide dichloro-diphenyl-trichloroethane (DDT). The pattern of sequence variation of the GstD1 locus from all four D. mojavensis populations, D. arizonae (sister species), and D. navojoa (outgroup) has been examined. The data suggest that in two populations of D. mojavensis GstD1 has gone through a period of adaptive amino acid evolution. Further analyses indicate that of the seven amino acid fixations that occurred in the D. mojavensis lineage, two of them occur in the active site pocket, potentially having a significant effect on substrate specificity and in the adaptation to alternative cactus hosts.
Population Genetic Analysis of the N-Acylsphingosine Amidohydrolase Gene Associated With Mental Activity in Humans
Authors: Kim Hie Lim , Satta Yoko
Published: February 2008

To understand the evolution of human mental activity, we performed population genetic analyses of nucleotide sequences (∼11 kb) from a worldwide sample of 60 chromosomes of the N-acylsphingosine amidohydrolase (ASAH1) gene. ASAH1 hydrolyzes ceramides and regulates neuronal development, and its deficiency often results in mental retardation. In the region (∼4.4 kb) encompassing exons 3 and 4 of this gene, two distinct lineages (V and M) have been segregating in the human population for 2.4 ± 0.4 million years (MY). The persistence of these two lineages is attributed to ancient population structure of humans in Africa. However, all haplotypes belonging to the V lineage exhibit strong linkage disequilibrium, a high frequency (62%), and small nucleotide diversity (π = 0.05%). These features indicate a signature of positive Darwinian selection for the V lineage. Compared with the orthologs in mammals and birds, it is only Val at amino acid site 72 that is found exclusively in the V lineage in humans, suggesting that this Val is a likely target of positive selection. Computer simulation confirms that demographic models of modern humans except for the ancient population structure cannot explain the presence of two distinct lineages, and neutrality is incompatible with the observed small genetic variation of the V lineage at ASAH1. On the basis of the above observations, it is argued that positive selection is possibly operating on ASAH1 in the modern human population.
DAF-16-Dependent Suppression of Immunity During Reproduction inCaenorhabditis elegans
Authors: Miyata Sachiko , Begun Jakob , Troemel Emily R , Ausubel Frederick M
Published: February 2008

To further understand how the nematode Caenorhabditis elegans defends itself against pathogen attack, we analyzed enhanced pathogen resistance (epr) mutants obtained from a forward genetic screen. We also examined several well-characterized sterile mutants that exhibit an Epr phenotype. We found that sterility and pathogen resistance are highly correlated and that resistance in both epr and sterile mutants is dependent on DAF-16 activity. Our data indicate that a DAF-16-dependent signaling pathway distinct from previously described pathways is involved in the activation of genes that confer resistance to bacterial pathogens. The timing of DAF-16-dependent gene activation in sterile mutants coincides with the onset of embryonic development in wild-type animals, suggesting that signals from developing embryos normally downregulate the immune response.
Essay Contest Reveals Misconceptions of High School Students in Genetics Content
Authors: Mills Shaw Kenna R , Van Horne Katie , Zhang Hubert , Boughman Joann
Published: February 2008

National educational organizations have called upon scientists to become involved in K–12 education reform. From sporadic interaction with students to more sustained partnerships with teachers, the engagement of scientists takes many forms. In this case, scientists from the American Society of Human Genetics (ASHG), the Genetics Society of America (GSA), and the National Society of Genetic Counselors (NSGC) have partnered to organize an essay contest for high school students as part of the activities surrounding National DNA Day. We describe a systematic analysis of 500 of 2443 total essays submitted in response to this contest over 2 years. Our analysis reveals the nature of student misconceptions in genetics, the possible sources of these misconceptions, and potential ways to galvanize genetics education.
Mutations in the Drosophila Mitochondrial tRNA Amidotransferase, bene/gatA, Cause Growth Defects in Mitotic and Endoreplicating Tissues
Authors: Morris Jason Z , Bergman Leah , Kruyer Anna , Gertsberg Mikhail , Guigova Adriana , Arias Ronald , Pogorzelska Monika
Published: February 2008

Rapid larval growth is essential in the development of most metazoans. In this article, we show that bene, a gene previously identified on the basis of its oogenesis defects, is also required for larval growth and viability. We show that all bene alleles disrupt gatA, which encodes the Drosophila homolog of glutamyl-tRNA(Gln) amidotransferase subunit A (GatA). bene alleles are now referred to as gatA. GatA proteins are highly conserved throughout eukaryotes and many prokaryotes. These enzymes are required for proper translation of the proteins encoded by the mitochondrial genome and by many eubacterial genomes. Mitotic and endoreplicating tissues in Drosophila gatA loss-of-function mutants grow slowly and never achieve wild-type size, and gatA larvae die before pupariation. gatA mutant eye clones exhibit growth and differentiation defects, indicating that gatA expression is required cell autonomously for normal growth. The gatA gene is widely expressed in mitotic and endoreplicating tissues.
Early Childhood Computer Experience and Cognitive Development among Urban Low-Income Preschoolers
Authors: Fish Angela M. , Li Xiaoming , McCarrick Katy , Butler Sheretta T. , Stanton Bonita , Brumitt Gail A. , Bhavnagri Navaz Peshotan , Holtrop Teresa , Partridge Ty
Published: February 2008

This study investigates the association between home computer experience and cognitive development among preschool children in inner-city Head Start programs. Approximately 200 children enrolled in four Head Start centers in Detroit, Michigan were recruited to participate in this study. Data was collected from parents regarding the children's experience with computers in the home environment, including their access to a computer, the amount of time spent on the computer, and types of programs used on the computer. Each child was assessed using the McCarthy Scales of Children's Abilities (MSCA) and the Boehm Test of Basic Concepts, Third Edition Preschool (Boehm-3). Results suggest that using a computer is positively correlated with some aspects of cognitive development. After controlling for parent's education and household income, children who had access to a computer in their home had significantly higher scores of the Verbal, Perceptual-Performance, and General Cognitive scales of the MSCA. Furthermore, frequency of children's computer use was related to scores on the Boehm-3. These results suggest that early computer use at home may be a positive influence in young children's cognitive development.
Implementing a Community-Based Falls-Prevention Program: From Drawing Board to Reality
Authors: Filiatrault Johanne , Parisien Manon , Laforest Sophie , Genest Carole , Gauvin Lise , Fournier Michel , Trickey Francine , Robitaille Yvonne
Published: February 2008

Several studies have demonstrated the efficacy of falls-prevention programs designed for community-dwelling seniors using randomized designs. However, little is known about the feasibility of implementing these programs under natural conditions and about the success of these programs when delivered under such conditions. The objectives of this paper are to (a) describe a multifactorial falls-prevention program (called Stand Up!) designed for independent community-dwelling seniors and (b) present the results of an analysis of the practicability of implementing this program in community-based settings. The program was implemented in the context of an effectiveness study in 10 community-based organizations in the Montreal metropolitan area. Data pertaining to the reach and delivery of the program as well as participation level show that a falls-prevention program addressing multiple risk factors can be successfully implemented in community-based settings.
Seniors Falls Investigative Methodology (SFIM): A Systems Approach to the Study of Falls in Seniors
Authors: Zecevic Aleksandra A. , Salmoni Alan W. , Lewko John H. , Vandervoort Anthony A.
Published: February 2008

An in-depth understanding of human factors and human error is lacking in current research on seniors' falls. Additional knowledge is needed to understand why seniors are falling. The purpose of this article is to describe the adapting of the Integrated Safety Investigation Methodology (ISIM) (used for investigating transportation and industrial accidents) to studying seniors' falls. An adapted version—the Seniors Falls Investigative Methodology (SFIM)—uses a systems approach to take an investigation beyond the immediate cause of an incident and reveal unsafe acts and deeply imbedded unsafe conditions that contribute to adverse outcomes. An example case study is used to describe six phases of the investigative process in detail. The SFIM has the potential to identify safety deficiencies; utilize existing knowledge about falls; establish a standardized reporting system; shift focus from the faller to the system; and guide targeted prevention.
A novel locus for idiopathic generalized epilepsy in French‐Canadian families maps to 10p11
Authors: Kinirons Peter , Verlaan Dominique J. , Dubé Marie‐Pierre , Poirier Josée , Deacon Charles , Lortie Anne , Clément Jean‐François , Desbiens Richard , Carmant Lionel , Cieuta‐Walti Cecile , Shevell Michael , Rouleau Guy A. , Cossette Patrick
Published: February 2008

Idiopathic generalized epilepsy (IGE) has evidence of a strong genetic etiology. We conducted genomewide linkage analysis for genes responsible for familial IGE in French‐Canadian pedigrees. Twenty families segregating autosomal dominant epilepsy were collected. Four larger IGE families sufficiently powerful for independent linkage analysis were genome‐scanned and follow‐up fine mapping was performed over regions with LOD scores >3.0. The genotyping of 16 smaller families was carried out at significantly linked loci for supportive linkage analysis and haplotype comparisons. One of the four families provided a significant linkage result at marker D10S1426 on chromosome 10 (two‐point LOD score = 3.05, theta = 0, multipoint LOD score = 3.18). Fine mapping revealed a segregating haplotype and key recombination breakpoints, suggesting a candidate gene interval of 6.5 Mb. Multipoint linkage analyses using the additional 16 families yielded a maximum LOD score under heterogeneity of 4.23 (alpha = 0.34) at this locus. Evaluation of recombination breakpoints in these families narrowed the candidate region to 1.7 Mb. Sequencing of the two known genes in this region, NRP1 and PARD3, was negative for mutation. Replication of linkage to this locus in other cohorts of IGE families is essential to characterize the underlying genetic mechanism for the disease. © 2008 Wiley‐Liss, Inc.
Prenatal diagnosis of mosaic trisomy 8q studied by ultrasound, cytogenetics, and array‐CGH
Authors: Wood Elizabeth , Dowey Sarah , Saul Daniel , Cain Colyn , Rossiter Judith , Blakemore Karin , Stetten Gail
Published: February 2008

Mosaic trisomy 8, also known as Warkany syndrome, has a well‐characterized constellation of phenotypic findings. Partial trisomy 8, including mosaic cases, has also been reported, with outcome and counseling dependent on the chromosomal segment involved and whether accompanied by partial aneuploidy for other chromosomes. We present a case of a fetus mosaic for trisomy of the entire long arm (q) of chromosome 8 without additional chromosomal aberrations. The diagnosis was made by amniocentesis performed following an 18 week sonogram that showed multiple fetal anomalies. Mosaicism for trisomy 8q was confirmed by routine karyotyping and fluorescent in situ hybridization (FISH) analysis. The case proved useful for testing the sensitivity of array comparative genomic hybridization (array‐CGH) with respect to segmental trisomy in the presence of chromosomal mosaicism. The phenotype of this fetus, which appears to be the first reported case involving mosaic trisomy 8 for the entire q arm of the chromosome, is described and compared to previously reported cases involving partial trisomy 8q. © 2008 Wiley‐Liss, Inc.
X‐linked congenital ataxia: A new locus maps to Xq25‐q27.1
Authors: Zanni Ginevra , Bertini Enrico , Bellcross Cecelia , Nedelec Brigitte , Froyen Guy , Neuhäuser Gerhard , Opitz John M. , Chelly Jamel
Published: February 2008

We report clinical and molecular studies on a large American family of Norwegian descent with X‐linked nonprogressive congenital ataxia (XCA) in six affected males over three generations. Neuroimaging showed global cerebellar hypoplasia without evidence of supratentorial anomalies. Linkage analysis resulted in a maximum LOD score Z = 3.44 for marker DXS1192 at θ = 0.0 with flanking markers DXS1047 and DXS1227 defining a region of 12 cM in Xq25‐q27.1. The clinical and neuroradiological findings in the present family are very similar to those described in two reported X‐linked families [Illarioshkin et al., 1996; Bertini et al., 2000]; however, the newly identified locus does not overlap with the one defined previously, indicating that there are at least two genes responsible for this rare form of X‐linked congenital cerebellar ataxia with normal intelligence. © 2008 Wiley‐Liss, Inc.
3q29 interstitial microduplication: A new syndrome in a three‐generation family
Authors: Lisi Emily C. , Hamosh Ada , Doheny Kimberly F. , Squibb Elizabeth , Jackson Barbara , Galczynski Rebecca , Thomas George H. , Batista Denise A.S.
Published: February 2008

Microdeletion and microduplication genetic syndromes are known to be a significant cause of developmental delay and dysmorphology. Utilizing high‐resolution chromosome analysis, array CGH and SNP technologies we identified a novel genomic syndrome comprising of an interstitial duplication of approximately 1.61 Mb at the distal end of chromosome 3 band q29. The imbalance was present in five individuals in a three generation family with clinical features including mild to moderate mental retardation and microcephaly. The duplicated segment overlaps with and is the genomic counterpart of the recently described microdeletion of 3q29. Both syndromes are proposed to occur by non‐allelic homologous recombination between regions of low copy repeats present around the breakpoints. © 2008 Wiley‐Liss, Inc.
Novel mutations causing medium chain acyl‐CoA dehydrogenase deficiency: Under‐representation of the common c.985 A > G mutation in the New York state population
Authors: Nichols Matthew J. , Saavedra‐Matiz Carlos A. , Pass Kenneth A. , Caggana Michele
Published: February 2008

Medium chain acyl‐CoA dehydrogenase deficiency (MCADD) is one of the most common fatty acid oxidation disorders. A subpopulation of children with MCADD present with metabolic crisis induced by fasting or illness, become lethargic, and can experience seizures or coma, culminating in a 20% mortality rate during the first episode. The frequency of these metabolic crises can be reduced with early diagnosis and treatment. The prevalence of MCADD in the United States is estimated to be 1 per 15,000 with p.K304E (c.985A > G) accounting for 90% of mutant alleles. In an 18‐month period after initiating screening, the New York State Newborn Screening Mass Spectrometry Laboratory screened 385,893 newborns and referred 511 samples with elevated (≥0.3 µmol/L) octanoylcarnitine (C8) levels for molecular testing. Of these referrals, six p.K304E homozygotes and 154 heterozygotes were identified. Twenty infants were biochemically confirmed with MCADD, per report from the child's pediatrician and/or treatment center. In these 20 cases, p.K304E accounted for only 47.5% of the mutant alleles. Further testing showed a second variant, p.Y42H, accounted for 7.5% of mutant alleles while the remaining 45% were unknown. Samples from all diagnosed non‐p.K304E homozygous infants, and samples with C8 levels ≥1.0 µmol/L were sequenced (n = 16). Six novel and seven previously reported mutations were detected. These results suggest that p.K304E has a far lower representation in New York newborns with MCADD than current literature estimates and its full mutational spectrum is still unknown. © 2008 Wiley‐Liss, Inc.
Ramos‐Arroyo syndrome: Long‐term follow‐up of previously reported family
Authors: Spurrier Jamie L. , Weaver David D.
Published: February 2008

Here we report on a family with corneal anesthesia, absence of the peripapillary choriocapillaris and retinal pigment epithelium, bilateral sensorineural hearing loss, unusual facial appearance, persistent ductus arteriosus, Hirschsprung disease, and moderate mental retardation. The first two generations of this family were reported previously by Ramos‐Arroyo et al. [Ramos‐Arroyo et al., 1987]. Two further affected individuals have been born into this family and we have observed additional manifestations not previously reported that appear to be part of this syndrome. The differential diagnosis of the condition is also discussed. We think this is a distinct autosomal dominant syndrome with variable expressivity, and have named the disorder the Ramos‐Arroyo syndrome. © 2008 Wiley‐Liss, Inc.
Genetic analysis of chromosome 11p13 and the PAX6 gene in a series of 125 cases referred with aniridia
Authors: Robinson David O. , Howarth Rachel J. , Williamson Kathleen A. , van Heyningen Veronica , Beal Sarah J. , Crolla John A.
Published: February 2008

A series of 125 patients referred primarily with aniridia classified as either sporadic (74), familial (24), or in association with WAGR syndrome (14) or other malformations (13) was analysed for mutations, initially by karyotyping and targeted FISH analysis of chromosome 11p13. These methods identified mutations in a significant proportion of patients, 34/125 (27%). Two cases had chromosome rearrangements involving 11p13, 16 cases had visible deletions, and 16 cases had cryptic deletions identified by FISH. The frequency of cryptic deletions in familial aniridia was 27% and in sporadic isolated aniridia was 22%. Of the 14 cases referred with WAGR syndrome, 10 (71%) had chromosomal deletions, 2 cryptic and 8 visible. Of the 13 cases with aniridia and other malformations, 5 (38%) had a chromosomal rearrangement or deletion. In 37 cases with no karyotypic or cryptic chromosome abnormality, sequence analysis of the PAX6 gene was performed. Mutations were identified in 33 cases; 22 with sporadic aniridia, 10 with familial aniridia and 1 with aniridia and other non‐WAGR syndrome associated anomalies. Overall, 67 of 71 cases (94%) undergoing full mutation analysis had a mutation in the PAX6 genomic region. © 2008 Wiley‐Liss, Inc.
A quantitative assessment of tremor and ataxia in FMR1 premutation carriers using CATSYS
Authors: Aguilar Dalila , Sigford Kathryn E. , Soontarapornchai Kultida , Nguyen Danh V. , Adams Patrick E. , Yuhas Jennifer M. , Tassone Flora , Hagerman Paul J. , Hagerman Randi J.
Published: February 2008

While an established protocol exists for diagnosing individuals with the fragile X‐associated tremor/ataxia syndrome (FXTAS), a quantitative measure of tremor and ataxia is needed. Using the CATSYS system to quantify movement abnormalities, we were able to record tremor, postural sway, manual (hand and finger) coordination, and reaction time in males with the FMR1 premutation, both with and without FXTAS, and compare them to controls. We evaluated 16 males diagnosed with FXTAS, 16 males with the premutation without FXTAS (non‐FXTAS), and 14 age‐matched controls. The CATSYS system detected, in the dominant hand, a difference in intention tremor between the FXTAS group and controls (P = 0.0008). The 30‐sec postural sway tasks revealed differences between the FXTAS group and controls, both with eyes open and closed (P = 0.0004 and P = 0.0031, respectively). There was also a difference between FXTAS and non‐FXTAS 30‐sec postural sway performances with eyes open (P = 0.0008). The 10‐sec postural sway tasks (with eyes closed) served to confirm the differences between the FXTAS group and both the controls (P = 0.0017) and non‐FXTAS premutation carriers (P = 0.0016). These results demonstrate that the quantitative measures of the CATSYS system can document significant differences in intention tremor and postural sway in patients with FXTAS compared to controls. © 2008 Wiley‐Liss, Inc.
To buy or to sell: cultural differences in stock market decisions based on price trends
Authors: Ji Li‐Jun , Zhang Zhiyong , Guo Tieyuan
Published: February 2008

Four studies compared the stock market decisions of Canadians and Chinese. In two studies using simple stock market trends, compared with Chinese, Canadians were more willing to sell and less willing to buy falling stock. But when the stock price was rising, the opposite occurred: Canadians were more willing to buy and less willing to sell. A third study showed that for complex stock price trends, Canadians were strongly influenced by the most recent price trends: they tended to predict that recent trends would continue and made selling decisions without considering the rest of the trend patterns; whereas the Chinese made reversal predictions for the dominant trends and made decisions that took both recent and early trends into consideration. Study 4 replicated the finding with experienced individual investors. These findings are consistent with the previous literature on different lay theories of change held by Chinese and North Americans. Copyright © 2008 John Wiley & Sons, Ltd.
Integrating cybernetic modeling with pathway analysis provides a dynamic, systems‐level description of metabolic control
Authors: Young Jamey D. , Henne Kristene L. , Morgan John A. , Konopka Allan E. , Ramkrishna Doraiswami
Published: February 2008

Cybernetic modeling strives to uncover the inbuilt regulatory programs of biological systems and leverage them toward computational prediction of metabolic dynamics. Because of its focus on incorporating the global aims of metabolism, cybernetic modeling provides a systems‐oriented approach for describing regulatory inputs and inferring the impact of regulation within biochemical networks. Combining cybernetic control laws with concepts from metabolic pathway analysis has culminated in a systematic strategy for constructing cybernetic models, which was previously lacking. The newly devised framework relies upon the simultaneous application of local controls that maximize the net flux through each elementary flux mode and global controls that modulate the activities of these modes to optimize the overall nutritional state of the cell. The modeling concepts are illustrated using a simple linear pathway and a larger network representing anaerobic E. coli central metabolism. The E. coli model successfully describes the metabolic shift that occurs upon deleting the pta‐ackA operon that is responsible for fermentative acetate production. The model also furnishes predictions that are consistent with experimental results obtained from additional knockout strains as well as strains expressing heterologous genes. Because of the stabilizing influence of the included control variables, the resulting cybernetic models are more robust and reliable than their predecessors in simulating the network response to imposed genetic and environmental perturbations. Biotechnol. Bioeng. 2008;100: 542–559. © 2008 Wiley Periodicals, Inc.
N‐Acyl homoserine lactonase promotes prevention of Erwinia virulence with Zwittermicin A‐producing strain Bacillus cereus
Authors: Zhao Changming , Zeng Hui , Yu Ziniu , Sun Ming
Published: February 2008

Zwittermicin A (ZwA), a hybrid polyketide‐ peptide antibiotic, and N‐acyl ‐homoserine‐lactonase (AHL‐lactonase), a kind of quorum‐quenching enzyme, have the potential to prevent the virulence of Erwinia carotovora, which is a major pathogen of soft rot. The purpose of this study was to combine the two agents in one host to improve their prevention efficacy. AHL‐lactonase was over‐expressed in the ZwA‐producing strain Bacillus cereus and derivates were identified to create genetically modified (GM) strains. The comparative results showed that neither ZwA nor AHL‐lactonase impacted the yield of the other; the increased yield of ZwA could promote the prevention efficacy of GM strains; Coexistence of ZwA and AHL‐lactonase in the GM strains had better prevention efficacy than either has separately. It is a potential therapy to provide more effective prevention and withstand gradually increasing pesticide‐resistance by combining the two antibacterial agents. Biotechnol. Bioeng. 2008;100: 599–603. © 2008 Wiley Periodicals, Inc.
A novel method for monitoring monoclonal antibody production during cell culture
Authors: Szmacinski Henryk , Smith Derek S. , Hanson Michael A. , Kostov Yordan , Lakowicz Joseph R. , Rao Govind
Published: February 2008

We describe a new format for surface‐based fluoroimmunoassays that allows detection of biomolecule interactions without separation steps. The bioactive layer was immobilized on the surface of a glass substrate covered with silver islands that provide optical amplification of the distinctive fluorescence signal from bound probes when compared to unbound probes. The technique used was phase‐modulation fluorometry that allows sensitive detection of bound probes with a very short lifetime in the presence of excess free probes in solution. The new method was applied to assay monoclonal antibody production during cell culture. Excellent agreement was found between the new method and ELISA analysis of hybridoma cell culture samples. It is predicted that the near real time monitoring of protein products during bioprocessing will be possible with the described technology. Biotechnol. Bioeng. 2008;100: 448–457. © 2008 Wiley Periodicals, Inc.
Development of a loop detector simulator (LOOPSIM) for in‐laboratory traffic research and education
Authors: Cheevarunothai Patikhom , Wang Yinhai , Nihan Nancy L.
Published: February 2008

This article describes a LOOP detector SIMulator (LOOPSIM) system designed for traffic research and education. LOOPSIM is capable of simulating calls from loop detectors and testing algorithms executable in the controller. It can also be used to simulate different patterns of traffic streams and replay collected loop event data. With the aid of LOOPSIM, researchers and educators can designate traffic characteristics in line with the purpose of the testing or teaching. © 2008 Wiley Periodicals, Inc. Comput Appl Eng Educ 16: 45–54, 2008; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20117
Detection of the activity of ion channels and pores by circular dichroism spectroscopy: G‐quartets as functional CD probes within chirogenic vesicles
Authors: Hennig Andreas , Matile Stefan
Published: February 2008

We introduce a method to detect the activity of ion channels and pores with circular dichroism (CD) spectroscopy. G‐quartets obtained by potassium templated self‐assembly of 5′‐guanosine monophosphate (GMP) are used as CD probes, the bee‐toxin melittin as representative pore and gramicidin A as representative ion channel. To detect the activity of pores with CD spectroscopy, vesicles were loaded with GMP at concentrations above the dissociation constant (KD) of G‐quartets. GMP efflux through added pores was detectable as CD silencing due to G‐quartet disassembly by local dilution. The Hill plot of melittin with Hill coefficient n = 4 was faithfully reproduced with CD detection. The same was true for counterion‐activated cell‐penetrating peptides, confirming their ability to mediate the export of anions such as GMP. The same method is not applicable to the CD detection of the activity of ion channels because GMP efflux does not occur. To do that, the potassium selectivity of G‐quartets was used. Namely, vesicles were loaded with GMP at concentrations above the dissociation constant (KD) of G‐quartets stabilized by potassium. External M/K cation exchange resulted in CD silencing by M/K antiport through the added ion channel followed by G‐quartet disassembly within the vesicle. Reversal of the direction of M/K antiport was achieved with Cs‐loaded vesicles and detected as the appearance of the CD signature of G‐quartets in response to K influx. Corroborative examples with gramicidin A include CD detection of the Eisenman I selectivity sequence and the Hill coefficient. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
Direct enantioselective HPLC monitoring of lipase‐catalyzed kinetic resolution of tiaprofenic acid in nonstandard HPLC organic solvents
Authors: Ghanem Ashraf , Aboul‐Enein Mohammed Nabil , El‐Azzouny Aida , El‐Behairy Mohammed F. , Al‐Humaidi Ebtessam , Alaidan Alwaleed A. , Amin Kamilia , Al‐Ahdal Mohammed N.
Published: February 2008

The first straightforward lipase‐catalyzed enantioselective access to enantiomerically enriched tiaprofenic acid as a versatile method in chiral separation of racemates is demonstrated. The latter was directly monitored by enantioselective HPLC using a 3,5‐dimethylphenylcarbamate derivative of cellulose‐based chiral stationary phase namely Chiralpak IB (the immobilized version of Chiralcel OD). Non‐standard HPLC organic solvents were used as diluent to dissolve the “difficult to dissolve” enzyme substrate (the acid) and as eluent for the simultaneous enantioselective HPLC baseline separation of both substrate and product in one run without any further derivatization. The existence of a non‐standard HPLC organic solvent (e.g., methyl tert‐butyl ether) in the mobile phase composition is mandatory to accomplish the simultaneous enantioselective HPLC baseline separation of both substrate and product. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
Complexity and stability of soliton management in periodically modulated and random systems
Authors: Malomed Boris A. , Driben Rodislav
Published: February 2008

A brief introduction is given to the concept of the soliton management, i.e., stable motion of localized pulses in media with strong periodic (or, sometimes, random) inhomogeneity, or conditions for the survival of solitons in models with strong time‐periodic modulation of linear or nonlinear coefficients. It is demonstrated that a class of systems can be identified, in which solitons remain robust inherently coherent objects in seemingly “hostile” environments. Most physical models belonging to this class originate in nonlinear optics and Bose‐Einstein condensation, although other examples are known too (in particular, in hydrodynamics). In this paper, the complexity of the soliton‐management systems, and the robustness of solitons in them are illustrated using a recently explored fiber‐optic setting combining a periodic concatenation of nonlinear and dispersive segments (the split‐step model) for bimodal optical signals (i.e., ones with two polarizations of light), which includes the polarization mode dispersion, i.e., random linear mixing of the two polarization components at junctions between the fiber segment. © 2008 Wiley Periodicals, Inc. Complexity, 2008
Synthesis and characterization of phosphates in the pseudo‐ternary melted systems Cs2O‐P2O5‐MIIO (MII – alkaline earth)
Authors: Zatovsky I. V. , Strutynska N. Yu. , Slobodyanik N. S. , Baumer V. N. , Shishkin O. V.
Published: February 2008

The crystallization of alkali‐earth phosphates in the melts of Cs2O‐P2O5‐MIIO (MII – Ca, Sr, Ba) pseudo‐ternary systems have been investigated at various Cs/P molar ratios and at fixed value of MII/P equal to 0.15. Type of the phosphate which crystallizes in melts depends on the Cs/P initial ratio. Crystallization fields of CsMIIP3O9, MII2P2O7 and Cs2MIIP2O7 were briefly investigated and characterized. The new diphosphate Cs2CaP2O7 has been obtained and investigated by the single crystal and powder X‐ray diffraction and FTIR‐ spectroscopy. It crystallizes in C 2/m space group, with the following parameters of the monoclinic cell: a = 10.261(2), b = 5.9316(12), c = 7.2404(14) Å, β = 118.54(3)°. The architecture of [CaP2O7]2‐ anionic sublattice, which is built up from [CaO6] octahedra and [P2O7] bitetrahedra, interlinked via the common oxygen vertices, gives rise to formation of hexagonal tunnels along crystallographic direction b, where caesium atoms are located. One of the most remarkable features of the structure is specific positional disorder of the diphosphate group, which is connected with the existence of two equiprobable half‐occupied sites of the bridging oxygen. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dislocation and microindentation analysis of vapour grown Bi2Te3‐xSex whiskers
Authors: Kunjomana A. G. , Chandrasekharan K. A.
Published: February 2008

The structural defects and microhardness of Bi2Te3‐xSex whiskers (x = 0, 0.2 and 0.4 at% Se) grown by physical vapour deposition (PVD) method have been investigated. Concentric pairs of dislocation loops were observed on the as‐grown surfaces of short hexagonal prisms. A systematic study of dislocations in these crystals was carried out by chemical etching technique. The effects of Se doping, annealing and quenching on the mechanical properties have also been studied on the prism faces of Bi2Te3‐xSex whiskers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth, structural, thermal and optical studies on L‐glutamic acid hydrobromide – A new semiorganic NLO material
Authors: Natarajan S. , Chitra G. P. , Britto Dhas S. A. Martin , Athimoolam S.
Published: February 2008

A new semiorganic crystal, L‐glutamic acid hydrobromide, C5H10NO4Br (GHB) has been grown from aqueous solution. The single crystal X‐ray analysis of the crystal showed that it belongs to the non‐centrosymmetric P212121 space group with protonated glutamic acid as cation and bromine as anion. The back‐bone conformations of the amino acid are in cis and trans form. The side‐chain conformations are observed to be in gauche I / trans / cis / trans forms. The characteristic ‘head‐to‐tail’ hydrogen bonding interaction is observed through a chain C(5) motif. Further, the crystal structure is stabilized by an intricate three‐dimensional hydrogen bonding network. TGA/DTA showed that the grown crystals are thermally stable upto 219 °C without any phase transition. The functional groups responsible for the various modes of vibrations were identified by using FTIR spectroscopy. UV‐Vis‐NIR spectra showed that the crystals have excellent transparency in the visible and infrared regions. The second harmonic generation (SHG) conversion efficiency was investigated to explore the NLO characteristics of the material. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Programed elution and peak profiles in electric field gradient focusing
Authors: Lin Shu‐Ling , Li Yuanyuan , Woolley Adam T. , Lee Milton L. , Tolley H. Dennis , Warnick Karl F.
Published: February 2008

Electric field gradient focusing (EFGF) methods have received increased attention in recent years, with potential applications demonstrated by several research groups. In order to move EFGF from the research stage to routine use in application areas, a more detailed understanding of practical aspects of device performance is required. Useful theoretical models for EFGF are available but have not been verified through systematic checks under a variety of conditions. In this paper, we compare modeled and experimental results for an EFGF device with the goal of optimizing the time sequence of voltages applied to the device for maximum resolution of analytes with close electrophoretic mobilities. Measured peak profiles depend strongly on the sequence of voltages applied to the device. We investigate the characteristic behavior of the elution profile under various voltage programs. Rapid voltage drops lead to fast elution of closely spaced protein peaks with narrow widths, whereas a carefully designed voltage program can be used to increase the separation between analytes and achieve higher resolution. Simulated and experimental results demonstrate that the behavior of analyte diffusion at an electric field singularity associated with the transition from the EFGF device to elution capillary can be used to separate analyte peaks which may not be resolved within the EFGF device itself, thereby increasing the achievable resolution of the EFGF technique.
Electrophoretic migration of proteins in semidilute polymer solutions
Authors: Oliver Gloria , Simpson Christina , Kerby Matthew B. , Tripathi Anubhav , Chauhan Anuj
Published: February 2008

We present a systematic study of the electrophoretic migration of 10–200 kDa protein fragments in dilute‐polymer solutions using microfluidic chips. The electrophoretic mobility and dispersion of protein samples were measured in a series of monodisperse polydimethylacrylamide (PDMA) polymers of different molecular masses (243, 443, and 764 kDa, polydispersivity index <2) of varying concentration. The polymer solutions were characterized using rheometry. Prior to loading onto the microchip, the polymer solution was mixed with known concentrations of SDS (SDS) surfactant and a staining dye. SDS‐denatured protein samples were electrokinetically injected, separated, and detected in the microchip using electric fields ranging from 100 to 300 V/cm. Our results show that the electrophoretic mobility of protein fragments decreases exponentially with the concentration c of the polymer solution. The mobility was found to decrease logarithmically with the molecular weight of the protein fragment. In addition, the mobility was found to be independent of the electric field in the separation channel. The dispersion is relatively independent of polymer concentration and it first increases with protein size and then decreases with a maximum at about 45 kDa. The resolution power of the device decreases with concentration of the PDMA solution but it is always better than 10% of the protein size. The protein migration does not seem to correspond to the Ogston or the reptation models. A semiempirical expression for mobility given by van Winkle fits the data very well.
Increased hepatic steatosis and insulin resistance in mice lacking hepatic androgen receptor
Authors: Lin Hung-Yun , Yu I-Chen , Wang Ruey-Shen , Chen Yei-Tsung , Liu Ning-Chun , Altuwaijri Saleh , Hsu Cheng-Lung , Ma Wen-Lung , Jokinen Jenny , Sparks Janet D. , Yeh Shuyuan , Chang Chawnshang
Published: February 2008

Early studies demonstrated that whole-body androgen receptor (AR)–knockout mice with hypogonadism exhibit insulin resistance. However, details about the mechanisms underlying how androgen/AR signaling regulates insulin sensitivity in individual organs remain unclear. We therefore generated hepatic AR-knockout (H-AR−/y) mice and found that male H-AR−/y mice, but not female H-AR−/− mice, fed a high-fat diet developed hepatic steatosis and insulin resistance, and aging male H-AR−/y mice fed chow exhibited moderate hepatic steatosis. We hypothesized that increased hepatic steatosis in obese male H-AR−/y mice resulted from decreased fatty acid β-oxidation, increased

de novo

lipid synthesis arising from decreased PPARα, increased sterol regulatory element binding protein 1c, and associated changes in target gene expression. Reduced insulin sensitivity in fat-fed H-AR−/y mice was associated with decreased phosphoinositide-3 kinase activity and increased phosphenolpyruvate carboxykinase expression and correlated with increased protein-tyrosine phosphatase 1B expression.

Conclusion:

Together, our results suggest that hepatic AR may play a vital role in preventing the development of insulin resistance and hepatic steatosis. AR agonists that specifically target hepatic AR might be developed to provide a better strategy for treatment of metabolic syndrome in men.
MicroRNA profiling in hepatocellular tumors is associated with clinical features and oncogene/tumor suppressor gene mutations
Authors: Ladeiro Yannick , Couchy Gabrielle , Balabaud Charles , Bioulac-Sage Paulette , Pelletier Laura , Rebouissou Sandra , Zucman-Rossi Jessica
Published: February 2008

Molecular classifications defining new tumor subtypes have been recently refined with genetic and transcriptomic analyses of benign and malignant hepatocellular tumors. Here, we performed microRNA (miRNA) profiling in two series of fully annotated liver tumors to uncover associations between oncogene/tumor suppressor mutations and clinical and pathological features. Expression levels of 250 miRNAs in 46 benign and malignant hepatocellular tumors were compared to those of 4 normal liver samples with quantitative reverse-transcriptase polymerase chain reaction. miRNAs associated with genetic and clinical characteristics were validated in a second series of 43 liver tumor samples and 16 nontumor samples. miRNA profiling unsupervised analysis classified samples in unique clusters characterized by histological features (tumor/nontumor,

P

< 0.001; benign/malignant tumors,

P

< 0.01; inflammatory adenoma and focal nodular hyperplasia,

P

< 0.01), clinical characteristics [hepatitis B virus (HBV) infection,

P

< 0.001; alcohol consumption,

P

< 0.05], and oncogene/tumor suppressor gene mutations [β-catenin,

P

< 0.01; hepatocyte nuclear factor 1α (HNF1α),

P

< 0.01]. Our study identified and validated miR-224 overexpression in all tumors and miR-200c, miR-200, miR-21, miR-224, miR-10b, and miR-222 specific deregulation in benign or malignant tumors. Moreover, miR-96 was overexpressed in HBV tumors, and miR-126* was down-regulated in alcohol-related hepatocellular carcinoma. Down-regulations of miR-107 and miR-375 were specifically associated with HNF1α and β-catenin gene mutations, respectively. miR-375 expression was highly correlated to that of β-catenin–targeted genes as miR-107 expression was correlated to that of HNF1α in a small interfering RNA cell line model. Thus, this strongly suggests that β-catenin and HNF1α could regulate miR-375 and miR-107 expression levels, respectively.

Conclusion:

Hepatocellular tumors may have a distinct miRNA expression fingerprint according to malignancy, risk factors, and oncogene/tumor suppressor gene alterations. Dissecting these relationships provides a new hypothesis to understand the functional impact of miRNA deregulation in liver tumorigenesis and the promising use of miRNAs as diagnostic markers.
Methods for Detection and Quantification of Polyphosphate and Polyphosphate Accumulating Microorganisms in Aquatic Sediments
Authors: Hupfer Michael , Glöss Stefanie , Schmieder Peter , Grossart Hans‐Peter
Published: February 2008

It has been speculated that the microbial P pool is highly variable in the uppermost layer of various aquatic sediments, especially when an excessive P accumulation in form of polyphosphate (Poly‐P) occurs. Poly‐P storage is a universal feature of many different organisms and has been technically optimised in wastewater treatment plants (WWTP) with enhanced biological phosphorus removal (EBPR). In the recent past, new insights into mechanisms of P elimination in WWTP almost exclusively depended on the development and application of novel methods like 31P‐NMR spectroscopy and molecular methods for identifying Poly‐P accumulating microorganisms (PAO). The aim of the present review is to compile current methods potentially available for detection and quantification of Poly‐P in sediments and to complement it with yet unpublished results to validate their application in natural sediments. The most powerful tool for reliable Poly‐P quantification in sediments is the liquid 31P‐NMR technique which has been successfully used for Poly‐P measurements in a variety of aquatic sediments. But the microorganisms as well as mechanisms involved in Poly‐P storage and cycling are largely unknown. Therefore, we also intend to stimulate future studies focusing on these encouraging topics in sediment research via the implementation of novel methods. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)